sqlite3: Update the included sqlite3 to 3.14.1

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 97207 insertions, 31215 deletions

diff --git a/sqlite3/sqlite3.c b/sqlite3/sqlite3.c
index a7f2677..ccddfe6 100644
--- a/sqlite3/sqlite3.c
+++ b/sqlite3/sqlite3.c
@@ -1,6 +1,6 @@
 /******************************************************************************
 ** This file is an amalgamation of many separate C source files from SQLite
-** version 3.7.9.  By combining all the individual C code files into this 
+** version 3.14.1.  By combining all the individual C code files into this 
 ** single large file, the entire code can be compiled as a single translation
 ** unit.  This allows many compilers to do optimizations that would not be
 ** possible if the files were compiled separately.  Performance improvements
@@ -22,9 +22,6 @@
 #ifndef SQLITE_PRIVATE
 # define SQLITE_PRIVATE static
 #endif
-#ifndef SQLITE_API
-# define SQLITE_API
-#endif
 /************** Begin file sqliteInt.h ***************************************/
 /*
 ** 2001 September 15
@@ -40,504 +37,225 @@
 ** Internal interface definitions for SQLite.
 **
 */
-#ifndef _SQLITEINT_H_
-#define _SQLITEINT_H_
+#ifndef SQLITEINT_H
+#define SQLITEINT_H
 
-/*
-** These #defines should enable >2GB file support on POSIX if the
-** underlying operating system supports it.  If the OS lacks
-** large file support, or if the OS is windows, these should be no-ops.
+/* Special Comments:
 **
-** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
-** system #includes.  Hence, this block of code must be the very first
-** code in all source files.
+** Some comments have special meaning to the tools that measure test
+** coverage:
 **
-** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
-** on the compiler command line.  This is necessary if you are compiling
-** on a recent machine (ex: Red Hat 7.2) but you want your code to work
-** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
-** without this option, LFS is enable.  But LFS does not exist in the kernel
-** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
-** portability you should omit LFS.
+**    NO_TEST                     - The branches on this line are not
+**                                  measured by branch coverage.  This is
+**                                  used on lines of code that actually
+**                                  implement parts of coverage testing.
 **
-** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
-*/
-#ifndef SQLITE_DISABLE_LFS
-# define _LARGE_FILE       1
-# ifndef _FILE_OFFSET_BITS
-#   define _FILE_OFFSET_BITS 64
-# endif
-# define _LARGEFILE_SOURCE 1
-#endif
-
-/*
-** Include the configuration header output by 'configure' if we're using the
-** autoconf-based build
-*/
-#ifdef _HAVE_SQLITE_CONFIG_H
-#include "config.h"
-#endif
-
-/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
-/************** Begin file sqliteLimit.h *************************************/
-/*
-** 2007 May 7
+**    OPTIMIZATION-IF-TRUE        - This branch is allowed to alway be false
+**                                  and the correct answer is still obtained,
+**                                  though perhaps more slowly.
 **
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
+**    OPTIMIZATION-IF-FALSE       - This branch is allowed to alway be true
+**                                  and the correct answer is still obtained,
+**                                  though perhaps more slowly.
 **
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
+**    PREVENTS-HARMLESS-OVERREAD  - This branch prevents a buffer overread
+**                                  that would be harmless and undetectable
+**                                  if it did occur.  
 **
-*************************************************************************
-** 
-** This file defines various limits of what SQLite can process.
+** In all cases, the special comment must be enclosed in the usual
+** slash-asterisk...asterisk-slash comment marks, with no spaces between the 
+** asterisks and the comment text.
 */
 
 /*
-** The maximum length of a TEXT or BLOB in bytes.   This also
-** limits the size of a row in a table or index.
-**
-** The hard limit is the ability of a 32-bit signed integer
-** to count the size: 2^31-1 or 2147483647.
+** Make sure the Tcl calling convention macro is defined.  This macro is
+** only used by test code and Tcl integration code.
 */
-#ifndef SQLITE_MAX_LENGTH
-# define SQLITE_MAX_LENGTH 1000000000
+#ifndef SQLITE_TCLAPI
+#  define SQLITE_TCLAPI
 #endif
 
 /*
-** This is the maximum number of
-**
-**    * Columns in a table
-**    * Columns in an index
-**    * Columns in a view
-**    * Terms in the SET clause of an UPDATE statement
-**    * Terms in the result set of a SELECT statement
-**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
-**    * Terms in the VALUES clause of an INSERT statement
-**
-** The hard upper limit here is 32676.  Most database people will
-** tell you that in a well-normalized database, you usually should
-** not have more than a dozen or so columns in any table.  And if
-** that is the case, there is no point in having more than a few
-** dozen values in any of the other situations described above.
+** Make sure that rand_s() is available on Windows systems with MSVC 2005
+** or higher.
 */
-#ifndef SQLITE_MAX_COLUMN
-# define SQLITE_MAX_COLUMN 2000
+#if defined(_MSC_VER) && _MSC_VER>=1400
+#  define _CRT_RAND_S
 #endif
 
 /*
-** The maximum length of a single SQL statement in bytes.
-**
-** It used to be the case that setting this value to zero would
-** turn the limit off.  That is no longer true.  It is not possible
-** to turn this limit off.
+** Include the header file used to customize the compiler options for MSVC.
+** This should be done first so that it can successfully prevent spurious
+** compiler warnings due to subsequent content in this file and other files
+** that are included by this file.
 */
-#ifndef SQLITE_MAX_SQL_LENGTH
-# define SQLITE_MAX_SQL_LENGTH 1000000000
-#endif
-
+/************** Include msvc.h in the middle of sqliteInt.h ******************/
+/************** Begin file msvc.h ********************************************/
 /*
-** The maximum depth of an expression tree. This is limited to 
-** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 
-** want to place more severe limits on the complexity of an 
-** expression.
+** 2015 January 12
 **
-** A value of 0 used to mean that the limit was not enforced.
-** But that is no longer true.  The limit is now strictly enforced
-** at all times.
-*/
-#ifndef SQLITE_MAX_EXPR_DEPTH
-# define SQLITE_MAX_EXPR_DEPTH 1000
-#endif
-
-/*
-** The maximum number of terms in a compound SELECT statement.
-** The code generator for compound SELECT statements does one
-** level of recursion for each term.  A stack overflow can result
-** if the number of terms is too large.  In practice, most SQL
-** never has more than 3 or 4 terms.  Use a value of 0 to disable
-** any limit on the number of terms in a compount SELECT.
-*/
-#ifndef SQLITE_MAX_COMPOUND_SELECT
-# define SQLITE_MAX_COMPOUND_SELECT 500
-#endif
-
-/*
-** The maximum number of opcodes in a VDBE program.
-** Not currently enforced.
-*/
-#ifndef SQLITE_MAX_VDBE_OP
-# define SQLITE_MAX_VDBE_OP 25000
-#endif
-
-/*
-** The maximum number of arguments to an SQL function.
-*/
-#ifndef SQLITE_MAX_FUNCTION_ARG
-# define SQLITE_MAX_FUNCTION_ARG 127
-#endif
-
-/*
-** The maximum number of in-memory pages to use for the main database
-** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
-*/
-#ifndef SQLITE_DEFAULT_CACHE_SIZE
-# define SQLITE_DEFAULT_CACHE_SIZE  2000
-#endif
-#ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE
-# define SQLITE_DEFAULT_TEMP_CACHE_SIZE  500
-#endif
-
-/*
-** The default number of frames to accumulate in the log file before
-** checkpointing the database in WAL mode.
-*/
-#ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT
-# define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT  1000
-#endif
-
-/*
-** The maximum number of attached databases.  This must be between 0
-** and 62.  The upper bound on 62 is because a 64-bit integer bitmap
-** is used internally to track attached databases.
-*/
-#ifndef SQLITE_MAX_ATTACHED
-# define SQLITE_MAX_ATTACHED 10
-#endif
-
-
-/*
-** The maximum value of a ?nnn wildcard that the parser will accept.
-*/
-#ifndef SQLITE_MAX_VARIABLE_NUMBER
-# define SQLITE_MAX_VARIABLE_NUMBER 999
-#endif
-
-/* Maximum page size.  The upper bound on this value is 65536.  This a limit
-** imposed by the use of 16-bit offsets within each page.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
 **
-** Earlier versions of SQLite allowed the user to change this value at
-** compile time. This is no longer permitted, on the grounds that it creates
-** a library that is technically incompatible with an SQLite library 
-** compiled with a different limit. If a process operating on a database 
-** with a page-size of 65536 bytes crashes, then an instance of SQLite 
-** compiled with the default page-size limit will not be able to rollback 
-** the aborted transaction. This could lead to database corruption.
-*/
-#ifdef SQLITE_MAX_PAGE_SIZE
-# undef SQLITE_MAX_PAGE_SIZE
-#endif
-#define SQLITE_MAX_PAGE_SIZE 65536
-
-
-/*
-** The default size of a database page.
-*/
-#ifndef SQLITE_DEFAULT_PAGE_SIZE
-# define SQLITE_DEFAULT_PAGE_SIZE 1024
-#endif
-#if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
-# undef SQLITE_DEFAULT_PAGE_SIZE
-# define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
-#endif
-
-/*
-** Ordinarily, if no value is explicitly provided, SQLite creates databases
-** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
-** device characteristics (sector-size and atomic write() support),
-** SQLite may choose a larger value. This constant is the maximum value
-** SQLite will choose on its own.
-*/
-#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
-# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
-#endif
-#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
-# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
-# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
-#endif
-
-
-/*
-** Maximum number of pages in one database file.
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
 **
-** This is really just the default value for the max_page_count pragma.
-** This value can be lowered (or raised) at run-time using that the
-** max_page_count macro.
-*/
-#ifndef SQLITE_MAX_PAGE_COUNT
-# define SQLITE_MAX_PAGE_COUNT 1073741823
-#endif
-
-/*
-** Maximum length (in bytes) of the pattern in a LIKE or GLOB
-** operator.
-*/
-#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
-# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
-#endif
-
-/*
-** Maximum depth of recursion for triggers.
+******************************************************************************
 **
-** A value of 1 means that a trigger program will not be able to itself
-** fire any triggers. A value of 0 means that no trigger programs at all 
-** may be executed.
-*/
-#ifndef SQLITE_MAX_TRIGGER_DEPTH
-# define SQLITE_MAX_TRIGGER_DEPTH 1000
-#endif
-
-/************** End of sqliteLimit.h *****************************************/
+** This file contains code that is specific to MSVC.
+*/
+#ifndef SQLITE_MSVC_H
+#define SQLITE_MSVC_H
+
+#if defined(_MSC_VER)
+#pragma warning(disable : 4054)
+#pragma warning(disable : 4055)
+#pragma warning(disable : 4100)
+#pragma warning(disable : 4127)
+#pragma warning(disable : 4130)
+#pragma warning(disable : 4152)
+#pragma warning(disable : 4189)
+#pragma warning(disable : 4206)
+#pragma warning(disable : 4210)
+#pragma warning(disable : 4232)
+#pragma warning(disable : 4244)
+#pragma warning(disable : 4305)
+#pragma warning(disable : 4306)
+#pragma warning(disable : 4702)
+#pragma warning(disable : 4706)
+#endif /* defined(_MSC_VER) */
+
+#endif /* SQLITE_MSVC_H */
+
+/************** End of msvc.h ************************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
 
-/* Disable nuisance warnings on Borland compilers */
-#if defined(__BORLANDC__)
-#pragma warn -rch /* unreachable code */
-#pragma warn -ccc /* Condition is always true or false */
-#pragma warn -aus /* Assigned value is never used */
-#pragma warn -csu /* Comparing signed and unsigned */
-#pragma warn -spa /* Suspicious pointer arithmetic */
-#endif
-
-/* Needed for various definitions... */
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE
-#endif
-
 /*
-** Include standard header files as necessary
+** Special setup for VxWorks
 */
-#ifdef HAVE_STDINT_H
-#include <stdint.h>
-#endif
-#ifdef HAVE_INTTYPES_H
-#include <inttypes.h>
-#endif
-
+/************** Include vxworks.h in the middle of sqliteInt.h ***************/
+/************** Begin file vxworks.h *****************************************/
 /*
-** The following macros are used to cast pointers to integers and
-** integers to pointers.  The way you do this varies from one compiler
-** to the next, so we have developed the following set of #if statements
-** to generate appropriate macros for a wide range of compilers.
+** 2015-03-02
 **
-** The correct "ANSI" way to do this is to use the intptr_t type. 
-** Unfortunately, that typedef is not available on all compilers, or
-** if it is available, it requires an #include of specific headers
-** that vary from one machine to the next.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
 **
-** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
-** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
-** So we have to define the macros in different ways depending on the
-** compiler.
-*/
-#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
-# define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
-# define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
-#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
-# define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
-# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
-#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
-# define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
-# define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
-#else                          /* Generates a warning - but it always works */
-# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
-# define SQLITE_PTR_TO_INT(X)  ((int)(X))
-#endif
-
-/*
-** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
-** 0 means mutexes are permanently disable and the library is never
-** threadsafe.  1 means the library is serialized which is the highest
-** level of threadsafety.  2 means the libary is multithreaded - multiple
-** threads can use SQLite as long as no two threads try to use the same
-** database connection at the same time.
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
 **
-** Older versions of SQLite used an optional THREADSAFE macro.
-** We support that for legacy.
+******************************************************************************
+**
+** This file contains code that is specific to Wind River's VxWorks
 */
-#if !defined(SQLITE_THREADSAFE)
-#if defined(THREADSAFE)
-# define SQLITE_THREADSAFE THREADSAFE
-#else
-# define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
-#endif
-#endif
-
-/*
-** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
-** It determines whether or not the features related to 
-** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
-** be overridden at runtime using the sqlite3_config() API.
+#if defined(__RTP__) || defined(_WRS_KERNEL)
+/* This is VxWorks.  Set up things specially for that OS
 */
-#if !defined(SQLITE_DEFAULT_MEMSTATUS)
-# define SQLITE_DEFAULT_MEMSTATUS 1
-#endif
+#include <vxWorks.h>
+#include <pthread.h>  /* amalgamator: dontcache */
+#define OS_VXWORKS 1
+#define SQLITE_OS_OTHER 0
+#define SQLITE_HOMEGROWN_RECURSIVE_MUTEX 1
+#define SQLITE_OMIT_LOAD_EXTENSION 1
+#define SQLITE_ENABLE_LOCKING_STYLE 0
+#define HAVE_UTIME 1
+#else
+/* This is not VxWorks. */
+#define OS_VXWORKS 0
+#define HAVE_FCHOWN 1
+#define HAVE_READLINK 1
+#define HAVE_LSTAT 1
+#endif /* defined(_WRS_KERNEL) */
+
+/************** End of vxworks.h *********************************************/
+/************** Continuing where we left off in sqliteInt.h ******************/
 
 /*
-** Exactly one of the following macros must be defined in order to
-** specify which memory allocation subsystem to use.
-**
-**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
-**     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
-**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
-**
-** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
-** assert() macro is enabled, each call into the Win32 native heap subsystem
-** will cause HeapValidate to be called.  If heap validation should fail, an
-** assertion will be triggered.
+** These #defines should enable >2GB file support on POSIX if the
+** underlying operating system supports it.  If the OS lacks
+** large file support, or if the OS is windows, these should be no-ops.
 **
-** (Historical note:  There used to be several other options, but we've
-** pared it down to just these three.)
+** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
+** system #includes.  Hence, this block of code must be the very first
+** code in all source files.
 **
-** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
-** the default.
-*/
-#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1
-# error "At most one of the following compile-time configuration options\
- is allows: SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG"
-#endif
-#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0
-# define SQLITE_SYSTEM_MALLOC 1
-#endif
-
-/*
-** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
-** sizes of memory allocations below this value where possible.
-*/
-#if !defined(SQLITE_MALLOC_SOFT_LIMIT)
-# define SQLITE_MALLOC_SOFT_LIMIT 1024
-#endif
-
-/*
-** We need to define _XOPEN_SOURCE as follows in order to enable
-** recursive mutexes on most Unix systems.  But Mac OS X is different.
-** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
-** so it is omitted there.  See ticket #2673.
+** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
+** on the compiler command line.  This is necessary if you are compiling
+** on a recent machine (ex: Red Hat 7.2) but you want your code to work
+** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
+** without this option, LFS is enable.  But LFS does not exist in the kernel
+** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
+** portability you should omit LFS.
 **
-** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
-** implemented on some systems.  So we avoid defining it at all
-** if it is already defined or if it is unneeded because we are
-** not doing a threadsafe build.  Ticket #2681.
+** The previous paragraph was written in 2005.  (This paragraph is written
+** on 2008-11-28.) These days, all Linux kernels support large files, so
+** you should probably leave LFS enabled.  But some embedded platforms might
+** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.
 **
-** See also ticket #2741.
-*/
-#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
-#  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
-#endif
-
-/*
-** The TCL headers are only needed when compiling the TCL bindings.
-*/
-#if defined(SQLITE_TCL) || defined(TCLSH)
-# include <tcl.h>
-#endif
-
-/*
-** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
-** Setting NDEBUG makes the code smaller and run faster.  So the following
-** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
-** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
-** feature.
+** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
 */
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
-# define NDEBUG 1
+#ifndef SQLITE_DISABLE_LFS
+# define _LARGE_FILE       1
+# ifndef _FILE_OFFSET_BITS
+#   define _FILE_OFFSET_BITS 64
+# endif
+# define _LARGEFILE_SOURCE 1
 #endif
 
-/*
-** The testcase() macro is used to aid in coverage testing.  When 
-** doing coverage testing, the condition inside the argument to
-** testcase() must be evaluated both true and false in order to
-** get full branch coverage.  The testcase() macro is inserted
-** to help ensure adequate test coverage in places where simple
-** condition/decision coverage is inadequate.  For example, testcase()
-** can be used to make sure boundary values are tested.  For
-** bitmask tests, testcase() can be used to make sure each bit
-** is significant and used at least once.  On switch statements
-** where multiple cases go to the same block of code, testcase()
-** can insure that all cases are evaluated.
-**
-*/
-#ifdef SQLITE_COVERAGE_TEST
-SQLITE_PRIVATE   void sqlite3Coverage(int);
-# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
+/* What version of GCC is being used.  0 means GCC is not being used */
+#ifdef __GNUC__
+# define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)
 #else
-# define testcase(X)
+# define GCC_VERSION 0
 #endif
 
-/*
-** The TESTONLY macro is used to enclose variable declarations or
-** other bits of code that are needed to support the arguments
-** within testcase() and assert() macros.
-*/
-#if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
-# define TESTONLY(X)  X
-#else
-# define TESTONLY(X)
+/* Needed for various definitions... */
+#if defined(__GNUC__) && !defined(_GNU_SOURCE)
+# define _GNU_SOURCE
 #endif
 
-/*
-** Sometimes we need a small amount of code such as a variable initialization
-** to setup for a later assert() statement.  We do not want this code to
-** appear when assert() is disabled.  The following macro is therefore
-** used to contain that setup code.  The "VVA" acronym stands for
-** "Verification, Validation, and Accreditation".  In other words, the
-** code within VVA_ONLY() will only run during verification processes.
-*/
-#ifndef NDEBUG
-# define VVA_ONLY(X)  X
-#else
-# define VVA_ONLY(X)
+#if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
+# define _BSD_SOURCE
 #endif
 
 /*
-** The ALWAYS and NEVER macros surround boolean expressions which 
-** are intended to always be true or false, respectively.  Such
-** expressions could be omitted from the code completely.  But they
-** are included in a few cases in order to enhance the resilience
-** of SQLite to unexpected behavior - to make the code "self-healing"
-** or "ductile" rather than being "brittle" and crashing at the first
-** hint of unplanned behavior.
-**
-** In other words, ALWAYS and NEVER are added for defensive code.
-**
-** When doing coverage testing ALWAYS and NEVER are hard-coded to
-** be true and false so that the unreachable code then specify will
-** not be counted as untested code.
+** For MinGW, check to see if we can include the header file containing its
+** version information, among other things.  Normally, this internal MinGW
+** header file would [only] be included automatically by other MinGW header
+** files; however, the contained version information is now required by this
+** header file to work around binary compatibility issues (see below) and
+** this is the only known way to reliably obtain it.  This entire #if block
+** would be completely unnecessary if there was any other way of detecting
+** MinGW via their preprocessor (e.g. if they customized their GCC to define
+** some MinGW-specific macros).  When compiling for MinGW, either the
+** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be
+** defined; otherwise, detection of conditions specific to MinGW will be
+** disabled.
 */
-#if defined(SQLITE_COVERAGE_TEST)
-# define ALWAYS(X)      (1)
-# define NEVER(X)       (0)
-#elif !defined(NDEBUG)
-# define ALWAYS(X)      ((X)?1:(assert(0),0))
-# define NEVER(X)       ((X)?(assert(0),1):0)
-#else
-# define ALWAYS(X)      (X)
-# define NEVER(X)       (X)
+#if defined(_HAVE_MINGW_H)
+# include "mingw.h"
+#elif defined(_HAVE__MINGW_H)
+# include "_mingw.h"
 #endif
 
 /*
-** Return true (non-zero) if the input is a integer that is too large
-** to fit in 32-bits.  This macro is used inside of various testcase()
-** macros to verify that we have tested SQLite for large-file support.
+** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T
+** define is required to maintain binary compatibility with the MSVC runtime
+** library in use (e.g. for Windows XP).
 */
-#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
-
-/*
-** The macro unlikely() is a hint that surrounds a boolean
-** expression that is usually false.  Macro likely() surrounds
-** a boolean expression that is usually true.  GCC is able to
-** use these hints to generate better code, sometimes.
-*/
-#if defined(__GNUC__) && 0
-# define likely(X)    __builtin_expect((X),1)
-# define unlikely(X)  __builtin_expect((X),0)
-#else
-# define likely(X)    !!(X)
-# define unlikely(X)  !!(X)
+#if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \
+    defined(_WIN32) && !defined(_WIN64) && \
+    defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \
+    defined(__MSVCRT__)
+# define _USE_32BIT_TIME_T
 #endif
 
+/* The public SQLite interface.  The _FILE_OFFSET_BITS macro must appear
+** first in QNX.  Also, the _USE_32BIT_TIME_T macro must appear first for
+** MinGW.
+*/
 /************** Include sqlite3.h in the middle of sqliteInt.h ***************/
 /************** Begin file sqlite3.h *****************************************/
 /*
@@ -565,15 +283,15 @@ SQLITE_PRIVATE   void sqlite3Coverage(int);
 **
 ** The official C-language API documentation for SQLite is derived
 ** from comments in this file.  This file is the authoritative source
-** on how SQLite interfaces are suppose to operate.
+** on how SQLite interfaces are supposed to operate.
 **
 ** The name of this file under configuration management is "sqlite.h.in".
 ** The makefile makes some minor changes to this file (such as inserting
 ** the version number) and changes its name to "sqlite3.h" as
 ** part of the build process.
 */
-#ifndef _SQLITE3_H_
-#define _SQLITE3_H_
+#ifndef SQLITE3_H
+#define SQLITE3_H
 #include <stdarg.h>     /* Needed for the definition of va_list */
 
 /*
@@ -585,21 +303,34 @@ extern "C" {
 
 
 /*
-** Add the ability to override 'extern'
+** Provide the ability to override linkage features of the interface.
 */
 #ifndef SQLITE_EXTERN
 # define SQLITE_EXTERN extern
 #endif
-
 #ifndef SQLITE_API
 # define SQLITE_API
 #endif
-
+#ifndef SQLITE_CDECL
+# define SQLITE_CDECL
+#endif
+#ifndef SQLITE_APICALL
+# define SQLITE_APICALL
+#endif
+#ifndef SQLITE_STDCALL
+# define SQLITE_STDCALL SQLITE_APICALL
+#endif
+#ifndef SQLITE_CALLBACK
+# define SQLITE_CALLBACK
+#endif
+#ifndef SQLITE_SYSAPI
+# define SQLITE_SYSAPI
+#endif
 
 /*
 ** These no-op macros are used in front of interfaces to mark those
 ** interfaces as either deprecated or experimental.  New applications
-** should not use deprecated interfaces - they are support for backwards
+** should not use deprecated interfaces - they are supported for backwards
 ** compatibility only.  Application writers should be aware that
 ** experimental interfaces are subject to change in point releases.
 **
@@ -649,9 +380,9 @@ extern "C" {
 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
 ** [sqlite_version()] and [sqlite_source_id()].
 */
-#define SQLITE_VERSION        "3.7.9"
-#define SQLITE_VERSION_NUMBER 3007009
-#define SQLITE_SOURCE_ID      "2011-10-29 19:25:08 5b82ec6fbbd2f4195ad06dd911de3817373ad5bf"
+#define SQLITE_VERSION        "3.14.1"
+#define SQLITE_VERSION_NUMBER 3014001
+#define SQLITE_SOURCE_ID      "2016-08-11 18:53:32 a12d8059770df4bca59e321c266410344242bf7b"
 
 /*
 ** CAPI3REF: Run-Time Library Version Numbers
@@ -662,7 +393,7 @@ extern "C" {
 ** but are associated with the library instead of the header file.  ^(Cautious
 ** programmers might include assert() statements in their application to
 ** verify that values returned by these interfaces match the macros in
-** the header, and thus insure that the application is
+** the header, and thus ensure that the application is
 ** compiled with matching library and header files.
 **
 ** <blockquote><pre>
@@ -684,9 +415,9 @@ extern "C" {
 ** See also: [sqlite_version()] and [sqlite_source_id()].
 */
 SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
-SQLITE_API const char *sqlite3_libversion(void);
-SQLITE_API const char *sqlite3_sourceid(void);
-SQLITE_API int sqlite3_libversion_number(void);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void);
 
 /*
 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
@@ -711,15 +442,15 @@ SQLITE_API int sqlite3_libversion_number(void);
 ** [sqlite_compileoption_get()] and the [compile_options pragma].
 */
 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
-SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
-SQLITE_API const char *sqlite3_compileoption_get(int N);
+SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N);
 #endif
 
 /*
 ** CAPI3REF: Test To See If The Library Is Threadsafe
 **
 ** ^The sqlite3_threadsafe() function returns zero if and only if
-** SQLite was compiled mutexing code omitted due to the
+** SQLite was compiled with mutexing code omitted due to the
 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
 **
 ** SQLite can be compiled with or without mutexes.  When
@@ -743,7 +474,7 @@ SQLITE_API const char *sqlite3_compileoption_get(int N);
 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
 ** can be fully or partially disabled using a call to [sqlite3_config()]
 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
-** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
+** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
 ** sqlite3_threadsafe() function shows only the compile-time setting of
 ** thread safety, not any run-time changes to that setting made by
 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
@@ -751,7 +482,7 @@ SQLITE_API const char *sqlite3_compileoption_get(int N);
 **
 ** See the [threading mode] documentation for additional information.
 */
-SQLITE_API int sqlite3_threadsafe(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void);
 
 /*
 ** CAPI3REF: Database Connection Handle
@@ -761,7 +492,8 @@ SQLITE_API int sqlite3_threadsafe(void);
 ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
 ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
-** is its destructor.  There are many other interfaces (such as
+** and [sqlite3_close_v2()] are its destructors.  There are many other
+** interfaces (such as
 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
 ** sqlite3 object.
@@ -807,29 +539,48 @@ typedef sqlite_uint64 sqlite3_uint64;
 
 /*
 ** CAPI3REF: Closing A Database Connection
-**
-** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
-** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
-** successfully destroyed and all associated resources are deallocated.
-**
-** Applications must [sqlite3_finalize | finalize] all [prepared statements]
-** and [sqlite3_blob_close | close] all [BLOB handles] associated with
-** the [sqlite3] object prior to attempting to close the object.  ^If
-** sqlite3_close() is called on a [database connection] that still has
-** outstanding [prepared statements] or [BLOB handles], then it returns
-** SQLITE_BUSY.
-**
-** ^If [sqlite3_close()] is invoked while a transaction is open,
+** DESTRUCTOR: sqlite3
+**
+** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
+** for the [sqlite3] object.
+** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
+** the [sqlite3] object is successfully destroyed and all associated
+** resources are deallocated.
+**
+** ^If the database connection is associated with unfinalized prepared
+** statements or unfinished sqlite3_backup objects then sqlite3_close()
+** will leave the database connection open and return [SQLITE_BUSY].
+** ^If sqlite3_close_v2() is called with unfinalized prepared statements
+** and/or unfinished sqlite3_backups, then the database connection becomes
+** an unusable "zombie" which will automatically be deallocated when the
+** last prepared statement is finalized or the last sqlite3_backup is
+** finished.  The sqlite3_close_v2() interface is intended for use with
+** host languages that are garbage collected, and where the order in which
+** destructors are called is arbitrary.
+**
+** Applications should [sqlite3_finalize | finalize] all [prepared statements],
+** [sqlite3_blob_close | close] all [BLOB handles], and 
+** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
+** with the [sqlite3] object prior to attempting to close the object.  ^If
+** sqlite3_close_v2() is called on a [database connection] that still has
+** outstanding [prepared statements], [BLOB handles], and/or
+** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
+** of resources is deferred until all [prepared statements], [BLOB handles],
+** and [sqlite3_backup] objects are also destroyed.
+**
+** ^If an [sqlite3] object is destroyed while a transaction is open,
 ** the transaction is automatically rolled back.
 **
-** The C parameter to [sqlite3_close(C)] must be either a NULL
+** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
+** must be either a NULL
 ** pointer or an [sqlite3] object pointer obtained
 ** from [sqlite3_open()], [sqlite3_open16()], or
 ** [sqlite3_open_v2()], and not previously closed.
-** ^Calling sqlite3_close() with a NULL pointer argument is a 
-** harmless no-op.
+** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
+** argument is a harmless no-op.
 */
-SQLITE_API int sqlite3_close(sqlite3 *);
+SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*);
+SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*);
 
 /*
 ** The type for a callback function.
@@ -840,6 +591,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 
 /*
 ** CAPI3REF: One-Step Query Execution Interface
+** METHOD: sqlite3
 **
 ** The sqlite3_exec() interface is a convenience wrapper around
 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
@@ -864,7 +616,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
 ** on error message strings returned through the 5th parameter of
-** of sqlite3_exec() after the error message string is no longer needed.
+** sqlite3_exec() after the error message string is no longer needed.
 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
 ** NULL before returning.
@@ -891,15 +643,15 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 ** Restrictions:
 **
 ** <ul>
-** <li> The application must insure that the 1st parameter to sqlite3_exec()
+** <li> The application must ensure that the 1st parameter to sqlite3_exec()
 **      is a valid and open [database connection].
-** <li> The application must not close [database connection] specified by
+** <li> The application must not close the [database connection] specified by
 **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
 ** <li> The application must not modify the SQL statement text passed into
 **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
 ** </ul>
 */
-SQLITE_API int sqlite3_exec(
+SQLITE_API int SQLITE_STDCALL sqlite3_exec(
   sqlite3*,                                  /* An open database */
   const char *sql,                           /* SQL to be evaluated */
   int (*callback)(void*,int,char**,char**),  /* Callback function */
@@ -909,16 +661,14 @@ SQLITE_API int sqlite3_exec(
 
 /*
 ** CAPI3REF: Result Codes
-** KEYWORDS: SQLITE_OK {error code} {error codes}
-** KEYWORDS: {result code} {result codes}
+** KEYWORDS: {result code definitions}
 **
 ** Many SQLite functions return an integer result code from the set shown
-** here in order to indicates success or failure.
+** here in order to indicate success or failure.
 **
 ** New error codes may be added in future versions of SQLite.
 **
-** See also: [SQLITE_IOERR_READ | extended result codes],
-** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
+** See also: [extended result code definitions]
 */
 #define SQLITE_OK           0   /* Successful result */
 /* beginning-of-error-codes */
@@ -948,32 +698,27 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_FORMAT      24   /* Auxiliary database format error */
 #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
 #define SQLITE_NOTADB      26   /* File opened that is not a database file */
+#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
+#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
 #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
 #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
 /* end-of-error-codes */
 
 /*
 ** CAPI3REF: Extended Result Codes
-** KEYWORDS: {extended error code} {extended error codes}
-** KEYWORDS: {extended result code} {extended result codes}
+** KEYWORDS: {extended result code definitions}
 **
-** In its default configuration, SQLite API routines return one of 26 integer
-** [SQLITE_OK | result codes].  However, experience has shown that many of
+** In its default configuration, SQLite API routines return one of 30 integer
+** [result codes].  However, experience has shown that many of
 ** these result codes are too coarse-grained.  They do not provide as
 ** much information about problems as programmers might like.  In an effort to
 ** address this, newer versions of SQLite (version 3.3.8 and later) include
 ** support for additional result codes that provide more detailed information
-** about errors. The extended result codes are enabled or disabled
+** about errors. These [extended result codes] are enabled or disabled
 ** on a per database connection basis using the
-** [sqlite3_extended_result_codes()] API.
-**
-** Some of the available extended result codes are listed here.
-** One may expect the number of extended result codes will be expand
-** over time.  Software that uses extended result codes should expect
-** to see new result codes in future releases of SQLite.
-**
-** The SQLITE_OK result code will never be extended.  It will always
-** be exactly zero.
+** [sqlite3_extended_result_codes()] API.  Or, the extended code for
+** the most recent error can be obtained using
+** [sqlite3_extended_errcode()].
 */
 #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
 #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
@@ -997,12 +742,40 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
 #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
 #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
+#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
+#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
+#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
+#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
+#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
+#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
+#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
+#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
+#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
+#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
+#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
+#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
+#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
+#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
+#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
+#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
+#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
+#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
+#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
+#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
+#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
+#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
+#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
+#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
+#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
+#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
+#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
+#define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))
 
 /*
 ** CAPI3REF: Flags For File Open Operations
@@ -1018,6 +791,7 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
 #define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
 #define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
+#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
 #define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
 #define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
 #define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
@@ -1037,7 +811,7 @@ SQLITE_API int sqlite3_exec(
 ** CAPI3REF: Device Characteristics
 **
 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
-** object returns an integer which is a vector of the these
+** object returns an integer which is a vector of these
 ** bit values expressing I/O characteristics of the mass storage
 ** device that holds the file that the [sqlite3_io_methods]
 ** refers to.
@@ -1051,7 +825,15 @@ SQLITE_API int sqlite3_exec(
 ** first then the size of the file is extended, never the other
 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
 ** information is written to disk in the same order as calls
-** to xWrite().
+** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
+** after reboot following a crash or power loss, the only bytes in a
+** file that were written at the application level might have changed
+** and that adjacent bytes, even bytes within the same sector are
+** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
+** flag indicate that a file cannot be deleted when open.  The
+** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
+** read-only media and cannot be changed even by processes with
+** elevated privileges.
 */
 #define SQLITE_IOCAP_ATOMIC                 0x00000001
 #define SQLITE_IOCAP_ATOMIC512              0x00000002
@@ -1065,6 +847,8 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_IOCAP_SAFE_APPEND            0x00000200
 #define SQLITE_IOCAP_SEQUENTIAL             0x00000400
 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
+#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
+#define SQLITE_IOCAP_IMMUTABLE              0x00002000
 
 /*
 ** CAPI3REF: File Locking Levels
@@ -1171,7 +955,7 @@ struct sqlite3_file {
 ** locking strategy (for example to use dot-file locks), to inquire
 ** about the status of a lock, or to break stale locks.  The SQLite
 ** core reserves all opcodes less than 100 for its own use.
-** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
+** A [file control opcodes | list of opcodes] less than 100 is available.
 ** Applications that define a custom xFileControl method should use opcodes
 ** greater than 100 to avoid conflicts.  VFS implementations should
 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
@@ -1236,24 +1020,31 @@ struct sqlite3_io_methods {
   void (*xShmBarrier)(sqlite3_file*);
   int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
   /* Methods above are valid for version 2 */
+  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
+  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
+  /* Methods above are valid for version 3 */
   /* Additional methods may be added in future releases */
 };
 
 /*
 ** CAPI3REF: Standard File Control Opcodes
+** KEYWORDS: {file control opcodes} {file control opcode}
 **
 ** These integer constants are opcodes for the xFileControl method
 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
 ** interface.
 **
+** <ul>
+** <li>[[SQLITE_FCNTL_LOCKSTATE]]
 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
 ** opcode causes the xFileControl method to write the current state of
 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
 ** into an integer that the pArg argument points to. This capability
-** is used during testing and only needs to be supported when SQLITE_TEST
-** is defined.
+** is used during testing and is only available when the SQLITE_TEST
+** compile-time option is used.
 **
+** <li>[[SQLITE_FCNTL_SIZE_HINT]]
 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
 ** layer a hint of how large the database file will grow to be during the
 ** current transaction.  This hint is not guaranteed to be accurate but it
@@ -1261,6 +1052,7 @@ struct sqlite3_io_methods {
 ** file space based on this hint in order to help writes to the database
 ** file run faster.
 **
+** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
 ** extends and truncates the database file in chunks of a size specified
 ** by the user. The fourth argument to [sqlite3_file_control()] should 
@@ -1269,29 +1061,51 @@ struct sqlite3_io_methods {
 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
 ** improve performance on some systems.
 **
+** <li>[[SQLITE_FCNTL_FILE_POINTER]]
 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
 ** to the [sqlite3_file] object associated with a particular database
-** connection.  See the [sqlite3_file_control()] documentation for
-** additional information.
-**
-** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
-** SQLite and sent to all VFSes in place of a call to the xSync method
-** when the database connection has [PRAGMA synchronous] set to OFF.)^
-** Some specialized VFSes need this signal in order to operate correctly
-** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
-** VFSes do not need this signal and should silently ignore this opcode.
-** Applications should not call [sqlite3_file_control()] with this
-** opcode as doing so may disrupt the operation of the specialized VFSes
-** that do require it.  
-**
+** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
+**
+** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
+** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
+** to the [sqlite3_file] object associated with the journal file (either
+** the [rollback journal] or the [write-ahead log]) for a particular database
+** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
+**
+** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
+** No longer in use.
+**
+** <li>[[SQLITE_FCNTL_SYNC]]
+** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
+** sent to the VFS immediately before the xSync method is invoked on a
+** database file descriptor. Or, if the xSync method is not invoked 
+** because the user has configured SQLite with 
+** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 
+** of the xSync method. In most cases, the pointer argument passed with
+** this file-control is NULL. However, if the database file is being synced
+** as part of a multi-database commit, the argument points to a nul-terminated
+** string containing the transactions master-journal file name. VFSes that 
+** do not need this signal should silently ignore this opcode. Applications 
+** should not call [sqlite3_file_control()] with this opcode as doing so may 
+** disrupt the operation of the specialized VFSes that do require it.  
+**
+** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
+** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
+** and sent to the VFS after a transaction has been committed immediately
+** but before the database is unlocked. VFSes that do not need this signal
+** should silently ignore this opcode. Applications should not call
+** [sqlite3_file_control()] with this opcode as doing so may disrupt the 
+** operation of the specialized VFSes that do require it.  
+**
+** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
 ** retry counts and intervals for certain disk I/O operations for the
-** windows [VFS] in order to work to provide robustness against
+** windows [VFS] in order to provide robustness in the presence of
 ** anti-virus programs.  By default, the windows VFS will retry file read,
-** file write, and file delete opertions up to 10 times, with a delay
+** file write, and file delete operations up to 10 times, with a delay
 ** of 25 milliseconds before the first retry and with the delay increasing
 ** by an additional 25 milliseconds with each subsequent retry.  This
-** opcode allows those to values (10 retries and 25 milliseconds of delay)
+** opcode allows these two values (10 retries and 25 milliseconds of delay)
 ** to be adjusted.  The values are changed for all database connections
 ** within the same process.  The argument is a pointer to an array of two
 ** integers where the first integer i the new retry count and the second
@@ -1300,8 +1114,9 @@ struct sqlite3_io_methods {
 ** into the array entry, allowing the current retry settings to be
 ** interrogated.  The zDbName parameter is ignored.
 **
+** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
-** persistent [WAL | Write AHead Log] setting.  By default, the auxiliary
+** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
 ** write ahead log and shared memory files used for transaction control
 ** are automatically deleted when the latest connection to the database
 ** closes.  Setting persistent WAL mode causes those files to persist after
@@ -1314,22 +1129,169 @@ struct sqlite3_io_methods {
 ** WAL mode.  If the integer is -1, then it is overwritten with the current
 ** WAL persistence setting.
 **
+** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
+** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
+** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
+** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
+** xDeviceCharacteristics methods. The fourth parameter to
+** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
+** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
+** mode.  If the integer is -1, then it is overwritten with the current
+** zero-damage mode setting.
+**
+** <li>[[SQLITE_FCNTL_OVERWRITE]]
 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
 ** a write transaction to indicate that, unless it is rolled back for some
 ** reason, the entire database file will be overwritten by the current 
 ** transaction. This is used by VACUUM operations.
+**
+** <li>[[SQLITE_FCNTL_VFSNAME]]
+** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
+** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
+** final bottom-level VFS are written into memory obtained from 
+** [sqlite3_malloc()] and the result is stored in the char* variable
+** that the fourth parameter of [sqlite3_file_control()] points to.
+** The caller is responsible for freeing the memory when done.  As with
+** all file-control actions, there is no guarantee that this will actually
+** do anything.  Callers should initialize the char* variable to a NULL
+** pointer in case this file-control is not implemented.  This file-control
+** is intended for diagnostic use only.
+**
+** <li>[[SQLITE_FCNTL_VFS_POINTER]]
+** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
+** [VFSes] currently in use.  ^(The argument X in
+** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
+** of type "[sqlite3_vfs] **".  This opcodes will set *X
+** to a pointer to the top-level VFS.)^
+** ^When there are multiple VFS shims in the stack, this opcode finds the
+** upper-most shim only.
+**
+** <li>[[SQLITE_FCNTL_PRAGMA]]
+** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 
+** file control is sent to the open [sqlite3_file] object corresponding
+** to the database file to which the pragma statement refers. ^The argument
+** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
+** pointers to strings (char**) in which the second element of the array
+** is the name of the pragma and the third element is the argument to the
+** pragma or NULL if the pragma has no argument.  ^The handler for an
+** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
+** of the char** argument point to a string obtained from [sqlite3_mprintf()]
+** or the equivalent and that string will become the result of the pragma or
+** the error message if the pragma fails. ^If the
+** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 
+** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
+** file control returns [SQLITE_OK], then the parser assumes that the
+** VFS has handled the PRAGMA itself and the parser generates a no-op
+** prepared statement if result string is NULL, or that returns a copy
+** of the result string if the string is non-NULL.
+** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
+** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
+** that the VFS encountered an error while handling the [PRAGMA] and the
+** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
+** file control occurs at the beginning of pragma statement analysis and so
+** it is able to override built-in [PRAGMA] statements.
+**
+** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
+** ^The [SQLITE_FCNTL_BUSYHANDLER]
+** file-control may be invoked by SQLite on the database file handle
+** shortly after it is opened in order to provide a custom VFS with access
+** to the connections busy-handler callback. The argument is of type (void **)
+** - an array of two (void *) values. The first (void *) actually points
+** to a function of type (int (*)(void *)). In order to invoke the connections
+** busy-handler, this function should be invoked with the second (void *) in
+** the array as the only argument. If it returns non-zero, then the operation
+** should be retried. If it returns zero, the custom VFS should abandon the
+** current operation.
+**
+** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
+** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
+** to have SQLite generate a
+** temporary filename using the same algorithm that is followed to generate
+** temporary filenames for TEMP tables and other internal uses.  The
+** argument should be a char** which will be filled with the filename
+** written into memory obtained from [sqlite3_malloc()].  The caller should
+** invoke [sqlite3_free()] on the result to avoid a memory leak.
+**
+** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
+** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
+** maximum number of bytes that will be used for memory-mapped I/O.
+** The argument is a pointer to a value of type sqlite3_int64 that
+** is an advisory maximum number of bytes in the file to memory map.  The
+** pointer is overwritten with the old value.  The limit is not changed if
+** the value originally pointed to is negative, and so the current limit 
+** can be queried by passing in a pointer to a negative number.  This
+** file-control is used internally to implement [PRAGMA mmap_size].
+**
+** <li>[[SQLITE_FCNTL_TRACE]]
+** The [SQLITE_FCNTL_TRACE] file control provides advisory information
+** to the VFS about what the higher layers of the SQLite stack are doing.
+** This file control is used by some VFS activity tracing [shims].
+** The argument is a zero-terminated string.  Higher layers in the
+** SQLite stack may generate instances of this file control if
+** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
+**
+** <li>[[SQLITE_FCNTL_HAS_MOVED]]
+** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
+** pointer to an integer and it writes a boolean into that integer depending
+** on whether or not the file has been renamed, moved, or deleted since it
+** was first opened.
+**
+** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
+** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
+** opcode causes the xFileControl method to swap the file handle with the one
+** pointed to by the pArg argument.  This capability is used during testing
+** and only needs to be supported when SQLITE_TEST is defined.
+**
+** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
+** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
+** be advantageous to block on the next WAL lock if the lock is not immediately
+** available.  The WAL subsystem issues this signal during rare
+** circumstances in order to fix a problem with priority inversion.
+** Applications should <em>not</em> use this file-control.
+**
+** <li>[[SQLITE_FCNTL_ZIPVFS]]
+** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
+** VFS should return SQLITE_NOTFOUND for this opcode.
+**
+** <li>[[SQLITE_FCNTL_RBU]]
+** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
+** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
+** this opcode.  
+** </ul>
 */
-#define SQLITE_FCNTL_LOCKSTATE        1
-#define SQLITE_GET_LOCKPROXYFILE      2
-#define SQLITE_SET_LOCKPROXYFILE      3
-#define SQLITE_LAST_ERRNO             4
-#define SQLITE_FCNTL_SIZE_HINT        5
-#define SQLITE_FCNTL_CHUNK_SIZE       6
-#define SQLITE_FCNTL_FILE_POINTER     7
-#define SQLITE_FCNTL_SYNC_OMITTED     8
-#define SQLITE_FCNTL_WIN32_AV_RETRY   9
-#define SQLITE_FCNTL_PERSIST_WAL     10
-#define SQLITE_FCNTL_OVERWRITE       11
+#define SQLITE_FCNTL_LOCKSTATE               1
+#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
+#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
+#define SQLITE_FCNTL_LAST_ERRNO              4
+#define SQLITE_FCNTL_SIZE_HINT               5
+#define SQLITE_FCNTL_CHUNK_SIZE              6
+#define SQLITE_FCNTL_FILE_POINTER            7
+#define SQLITE_FCNTL_SYNC_OMITTED            8
+#define SQLITE_FCNTL_WIN32_AV_RETRY          9
+#define SQLITE_FCNTL_PERSIST_WAL            10
+#define SQLITE_FCNTL_OVERWRITE              11
+#define SQLITE_FCNTL_VFSNAME                12
+#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
+#define SQLITE_FCNTL_PRAGMA                 14
+#define SQLITE_FCNTL_BUSYHANDLER            15
+#define SQLITE_FCNTL_TEMPFILENAME           16
+#define SQLITE_FCNTL_MMAP_SIZE              18
+#define SQLITE_FCNTL_TRACE                  19
+#define SQLITE_FCNTL_HAS_MOVED              20
+#define SQLITE_FCNTL_SYNC                   21
+#define SQLITE_FCNTL_COMMIT_PHASETWO        22
+#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
+#define SQLITE_FCNTL_WAL_BLOCK              24
+#define SQLITE_FCNTL_ZIPVFS                 25
+#define SQLITE_FCNTL_RBU                    26
+#define SQLITE_FCNTL_VFS_POINTER            27
+#define SQLITE_FCNTL_JOURNAL_POINTER        28
+
+/* deprecated names */
+#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
+#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
+#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO
+
 
 /*
 ** CAPI3REF: Mutex Handle
@@ -1344,6 +1306,16 @@ struct sqlite3_io_methods {
 typedef struct sqlite3_mutex sqlite3_mutex;
 
 /*
+** CAPI3REF: Loadable Extension Thunk
+**
+** A pointer to the opaque sqlite3_api_routines structure is passed as
+** the third parameter to entry points of [loadable extensions].  This
+** structure must be typedefed in order to work around compiler warnings
+** on some platforms.
+*/
+typedef struct sqlite3_api_routines sqlite3_api_routines;
+
+/*
 ** CAPI3REF: OS Interface Object
 **
 ** An instance of the sqlite3_vfs object defines the interface between
@@ -1384,7 +1356,7 @@ typedef struct sqlite3_mutex sqlite3_mutex;
 ** from xFullPathname() with an optional suffix added.
 ** ^If a suffix is added to the zFilename parameter, it will
 ** consist of a single "-" character followed by no more than
-** 10 alphanumeric and/or "-" characters.
+** 11 alphanumeric and/or "-" characters.
 ** ^SQLite further guarantees that
 ** the string will be valid and unchanged until xClose() is
 ** called. Because of the previous sentence,
@@ -1536,7 +1508,7 @@ struct sqlite3_vfs {
   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
   /*
   ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
-  ** New fields may be appended in figure versions.  The iVersion
+  ** New fields may be appended in future versions.  The iVersion
   ** value will increment whenever this happens. 
   */
 };
@@ -1581,7 +1553,7 @@ struct sqlite3_vfs {
 ** </ul>
 **
 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
-** was given no the corresponding lock.  
+** was given on the corresponding lock.  
 **
 ** The xShmLock method can transition between unlocked and SHARED or
 ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
@@ -1678,10 +1650,10 @@ struct sqlite3_vfs {
 ** must return [SQLITE_OK] on success and some other [error code] upon
 ** failure.
 */
-SQLITE_API int sqlite3_initialize(void);
-SQLITE_API int sqlite3_shutdown(void);
-SQLITE_API int sqlite3_os_init(void);
-SQLITE_API int sqlite3_os_end(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void);
+SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void);
 
 /*
 ** CAPI3REF: Configuring The SQLite Library
@@ -1692,9 +1664,11 @@ SQLITE_API int sqlite3_os_end(void);
 ** applications and so this routine is usually not necessary.  It is
 ** provided to support rare applications with unusual needs.
 **
-** The sqlite3_config() interface is not threadsafe.  The application
-** must insure that no other SQLite interfaces are invoked by other
-** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
+** <b>The sqlite3_config() interface is not threadsafe. The application
+** must ensure that no other SQLite interfaces are invoked by other
+** threads while sqlite3_config() is running.</b>
+**
+** The sqlite3_config() interface
 ** may only be invoked prior to library initialization using
 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
@@ -1712,10 +1686,11 @@ SQLITE_API int sqlite3_os_end(void);
 ** ^If the option is unknown or SQLite is unable to set the option
 ** then this routine returns a non-zero [error code].
 */
-SQLITE_API int sqlite3_config(int, ...);
+SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...);
 
 /*
 ** CAPI3REF: Configure database connections
+** METHOD: sqlite3
 **
 ** The sqlite3_db_config() interface is used to make configuration
 ** changes to a [database connection].  The interface is similar to
@@ -1730,7 +1705,7 @@ SQLITE_API int sqlite3_config(int, ...);
 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
 ** the call is considered successful.
 */
-SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
+SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...);
 
 /*
 ** CAPI3REF: Memory Allocation Routines
@@ -1774,7 +1749,7 @@ SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
 ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 
 ** that causes the corresponding memory allocation to fail.
 **
-** The xInit method initializes the memory allocator.  (For example,
+** The xInit method initializes the memory allocator.  For example,
 ** it might allocate any require mutexes or initialize internal data
 ** structures.  The xShutdown method is invoked (indirectly) by
 ** [sqlite3_shutdown()] and should deallocate any resources acquired
@@ -1864,31 +1839,33 @@ struct sqlite3_mem_methods {
 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
 **
 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
-** <dd> ^(This option takes a single argument which is a pointer to an
-** instance of the [sqlite3_mem_methods] structure.  The argument specifies
+** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 
+** a pointer to an instance of the [sqlite3_mem_methods] structure.
+** The argument specifies
 ** alternative low-level memory allocation routines to be used in place of
 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
 ** its own private copy of the content of the [sqlite3_mem_methods] structure
 ** before the [sqlite3_config()] call returns.</dd>
 **
 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
-** <dd> ^(This option takes a single argument which is a pointer to an
-** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
+** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
+** is a pointer to an instance of the [sqlite3_mem_methods] structure.
+** The [sqlite3_mem_methods]
 ** structure is filled with the currently defined memory allocation routines.)^
 ** This option can be used to overload the default memory allocation
 ** routines with a wrapper that simulations memory allocation failure or
 ** tracks memory usage, for example. </dd>
 **
 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
-** <dd> ^This option takes single argument of type int, interpreted as a 
-** boolean, which enables or disables the collection of memory allocation 
-** statistics. ^(When memory allocation statistics are disabled, the 
-** following SQLite interfaces become non-operational:
+** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
+** interpreted as a boolean, which enables or disables the collection of
+** memory allocation statistics. ^(When memory allocation statistics are
+** disabled, the following SQLite interfaces become non-operational:
 **   <ul>
 **   <li> [sqlite3_memory_used()]
 **   <li> [sqlite3_memory_highwater()]
 **   <li> [sqlite3_soft_heap_limit64()]
-**   <li> [sqlite3_status()]
+**   <li> [sqlite3_status64()]
 **   </ul>)^
 ** ^Memory allocation statistics are enabled by default unless SQLite is
 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
@@ -1896,53 +1873,72 @@ struct sqlite3_mem_methods {
 ** </dd>
 **
 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
-** <dd> ^This option specifies a static memory buffer that SQLite can use for
-** scratch memory.  There are three arguments:  A pointer an 8-byte
+** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
+** that SQLite can use for scratch memory.  ^(There are three arguments
+** to SQLITE_CONFIG_SCRATCH:  A pointer an 8-byte
 ** aligned memory buffer from which the scratch allocations will be
 ** drawn, the size of each scratch allocation (sz),
-** and the maximum number of scratch allocations (N).  The sz
-** argument must be a multiple of 16.
+** and the maximum number of scratch allocations (N).)^
 ** The first argument must be a pointer to an 8-byte aligned buffer
 ** of at least sz*N bytes of memory.
-** ^SQLite will use no more than two scratch buffers per thread.  So
-** N should be set to twice the expected maximum number of threads.
-** ^SQLite will never require a scratch buffer that is more than 6
-** times the database page size. ^If SQLite needs needs additional
+** ^SQLite will not use more than one scratch buffers per thread.
+** ^SQLite will never request a scratch buffer that is more than 6
+** times the database page size.
+** ^If SQLite needs needs additional
 ** scratch memory beyond what is provided by this configuration option, then 
-** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
+** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
+** ^When the application provides any amount of scratch memory using
+** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
+** [sqlite3_malloc|heap allocations].
+** This can help [Robson proof|prevent memory allocation failures] due to heap
+** fragmentation in low-memory embedded systems.
+** </dd>
 **
 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
-** <dd> ^This option specifies a static memory buffer that SQLite can use for
-** the database page cache with the default page cache implementation.  
-** This configuration should not be used if an application-define page
-** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
-** There are three arguments to this option: A pointer to 8-byte aligned
-** memory, the size of each page buffer (sz), and the number of pages (N).
+** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
+** that SQLite can use for the database page cache with the default page
+** cache implementation.  
+** This configuration option is a no-op if an application-define page
+** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
+** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
+** 8-byte aligned memory (pMem), the size of each page cache line (sz),
+** and the number of cache lines (N).
 ** The sz argument should be the size of the largest database page
-** (a power of two between 512 and 32768) plus a little extra for each
-** page header.  ^The page header size is 20 to 40 bytes depending on
-** the host architecture.  ^It is harmless, apart from the wasted memory,
-** to make sz a little too large.  The first
-** argument should point to an allocation of at least sz*N bytes of memory.
-** ^SQLite will use the memory provided by the first argument to satisfy its
-** memory needs for the first N pages that it adds to cache.  ^If additional
-** page cache memory is needed beyond what is provided by this option, then
-** SQLite goes to [sqlite3_malloc()] for the additional storage space.
-** The pointer in the first argument must
-** be aligned to an 8-byte boundary or subsequent behavior of SQLite
-** will be undefined.</dd>
+** (a power of two between 512 and 65536) plus some extra bytes for each
+** page header.  ^The number of extra bytes needed by the page header
+** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
+** ^It is harmless, apart from the wasted memory,
+** for the sz parameter to be larger than necessary.  The pMem
+** argument must be either a NULL pointer or a pointer to an 8-byte
+** aligned block of memory of at least sz*N bytes, otherwise
+** subsequent behavior is undefined.
+** ^When pMem is not NULL, SQLite will strive to use the memory provided
+** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
+** a page cache line is larger than sz bytes or if all of the pMem buffer
+** is exhausted.
+** ^If pMem is NULL and N is non-zero, then each database connection
+** does an initial bulk allocation for page cache memory
+** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
+** of -1024*N bytes if N is negative, . ^If additional
+** page cache memory is needed beyond what is provided by the initial
+** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
+** additional cache line. </dd>
 **
 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
-** <dd> ^This option specifies a static memory buffer that SQLite will use
-** for all of its dynamic memory allocation needs beyond those provided
-** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
-** There are three arguments: An 8-byte aligned pointer to the memory,
+** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 
+** that SQLite will use for all of its dynamic memory allocation needs
+** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
+** [SQLITE_CONFIG_PAGECACHE].
+** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
+** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
+** [SQLITE_ERROR] if invoked otherwise.
+** ^There are three arguments to SQLITE_CONFIG_HEAP:
+** An 8-byte aligned pointer to the memory,
 ** the number of bytes in the memory buffer, and the minimum allocation size.
 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
 ** to using its default memory allocator (the system malloc() implementation),
 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
-** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
-** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
+** memory pointer is not NULL then the alternative memory
 ** allocator is engaged to handle all of SQLites memory allocation needs.
 ** The first pointer (the memory pointer) must be aligned to an 8-byte
 ** boundary or subsequent behavior of SQLite will be undefined.
@@ -1950,11 +1946,11 @@ struct sqlite3_mem_methods {
 ** for the minimum allocation size are 2**5 through 2**8.</dd>
 **
 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
-** <dd> ^(This option takes a single argument which is a pointer to an
-** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
-** alternative low-level mutex routines to be used in place
-** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
-** content of the [sqlite3_mutex_methods] structure before the call to
+** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
+** pointer to an instance of the [sqlite3_mutex_methods] structure.
+** The argument specifies alternative low-level mutex routines to be used
+** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
+** the content of the [sqlite3_mutex_methods] structure before the call to
 ** [sqlite3_config()] returns. ^If SQLite is compiled with
 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
 ** the entire mutexing subsystem is omitted from the build and hence calls to
@@ -1962,8 +1958,8 @@ struct sqlite3_mem_methods {
 ** return [SQLITE_ERROR].</dd>
 **
 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
-** <dd> ^(This option takes a single argument which is a pointer to an
-** instance of the [sqlite3_mutex_methods] structure.  The
+** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
+** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
 ** [sqlite3_mutex_methods]
 ** structure is filled with the currently defined mutex routines.)^
 ** This option can be used to overload the default mutex allocation
@@ -1975,28 +1971,30 @@ struct sqlite3_mem_methods {
 ** return [SQLITE_ERROR].</dd>
 **
 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
-** <dd> ^(This option takes two arguments that determine the default
-** memory allocation for the lookaside memory allocator on each
-** [database connection].  The first argument is the
+** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
+** the default size of lookaside memory on each [database connection].
+** The first argument is the
 ** size of each lookaside buffer slot and the second is the number of
-** slots allocated to each database connection.)^  ^(This option sets the
-** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
-** verb to [sqlite3_db_config()] can be used to change the lookaside
+** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
+** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
+** option to [sqlite3_db_config()] can be used to change the lookaside
 ** configuration on individual connections.)^ </dd>
 **
-** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt>
-** <dd> ^(This option takes a single argument which is a pointer to
-** an [sqlite3_pcache_methods] object.  This object specifies the interface
-** to a custom page cache implementation.)^  ^SQLite makes a copy of the
-** object and uses it for page cache memory allocations.</dd>
+** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
+** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 
+** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
+** the interface to a custom page cache implementation.)^
+** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
 **
-** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt>
-** <dd> ^(This option takes a single argument which is a pointer to an
-** [sqlite3_pcache_methods] object.  SQLite copies of the current
-** page cache implementation into that object.)^ </dd>
+** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
+** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
+** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
+** the current page cache implementation into that object.)^ </dd>
 **
 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
-** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
+** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
+** global [error log].
+** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
 ** function with a call signature of void(*)(void*,int,const char*), 
 ** and a pointer to void. ^If the function pointer is not NULL, it is
 ** invoked by [sqlite3_log()] to process each logging event.  ^If the
@@ -2014,17 +2012,108 @@ struct sqlite3_mem_methods {
 ** function must be threadsafe. </dd>
 **
 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
-** <dd> This option takes a single argument of type int. If non-zero, then
-** URI handling is globally enabled. If the parameter is zero, then URI handling
-** is globally disabled. If URI handling is globally enabled, all filenames
-** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
+** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
+** If non-zero, then URI handling is globally enabled. If the parameter is zero,
+** then URI handling is globally disabled.)^ ^If URI handling is globally
+** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
+** [sqlite3_open16()] or
 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
-** connection is opened. If it is globally disabled, filenames are
+** connection is opened. ^If it is globally disabled, filenames are
 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
-** database connection is opened. By default, URI handling is globally
+** database connection is opened. ^(By default, URI handling is globally
 ** disabled. The default value may be changed by compiling with the
-** [SQLITE_USE_URI] symbol defined.
+** [SQLITE_USE_URI] symbol defined.)^
+**
+** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
+** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
+** argument which is interpreted as a boolean in order to enable or disable
+** the use of covering indices for full table scans in the query optimizer.
+** ^The default setting is determined
+** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
+** if that compile-time option is omitted.
+** The ability to disable the use of covering indices for full table scans
+** is because some incorrectly coded legacy applications might malfunction
+** when the optimization is enabled.  Providing the ability to
+** disable the optimization allows the older, buggy application code to work
+** without change even with newer versions of SQLite.
+**
+** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
+** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
+** <dd> These options are obsolete and should not be used by new code.
+** They are retained for backwards compatibility but are now no-ops.
+** </dd>
+**
+** [[SQLITE_CONFIG_SQLLOG]]
+** <dt>SQLITE_CONFIG_SQLLOG
+** <dd>This option is only available if sqlite is compiled with the
+** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
+** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
+** The second should be of type (void*). The callback is invoked by the library
+** in three separate circumstances, identified by the value passed as the
+** fourth parameter. If the fourth parameter is 0, then the database connection
+** passed as the second argument has just been opened. The third argument
+** points to a buffer containing the name of the main database file. If the
+** fourth parameter is 1, then the SQL statement that the third parameter
+** points to has just been executed. Or, if the fourth parameter is 2, then
+** the connection being passed as the second parameter is being closed. The
+** third parameter is passed NULL In this case.  An example of using this
+** configuration option can be seen in the "test_sqllog.c" source file in
+** the canonical SQLite source tree.</dd>
+**
+** [[SQLITE_CONFIG_MMAP_SIZE]]
+** <dt>SQLITE_CONFIG_MMAP_SIZE
+** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
+** that are the default mmap size limit (the default setting for
+** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
+** ^The default setting can be overridden by each database connection using
+** either the [PRAGMA mmap_size] command, or by using the
+** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
+** will be silently truncated if necessary so that it does not exceed the
+** compile-time maximum mmap size set by the
+** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
+** ^If either argument to this option is negative, then that argument is
+** changed to its compile-time default.
+**
+** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
+** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
+** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
+** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
+** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
+** that specifies the maximum size of the created heap.
+**
+** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
+** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
+** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
+** is a pointer to an integer and writes into that integer the number of extra
+** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
+** The amount of extra space required can change depending on the compiler,
+** target platform, and SQLite version.
+**
+** [[SQLITE_CONFIG_PMASZ]]
+** <dt>SQLITE_CONFIG_PMASZ
+** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
+** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
+** sorter to that integer.  The default minimum PMA Size is set by the
+** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
+** to help with sort operations when multithreaded sorting
+** is enabled (using the [PRAGMA threads] command) and the amount of content
+** to be sorted exceeds the page size times the minimum of the
+** [PRAGMA cache_size] setting and this value.
+**
+** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
+** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
+** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
+** becomes the [statement journal] spill-to-disk threshold.  
+** [Statement journals] are held in memory until their size (in bytes)
+** exceeds this threshold, at which point they are written to disk.
+** Or if the threshold is -1, statement journals are always held
+** exclusively in memory.
+** Since many statement journals never become large, setting the spill
+** threshold to a value such as 64KiB can greatly reduce the amount of
+** I/O required to support statement rollback.
+** The default value for this setting is controlled by the
+** [SQLITE_STMTJRNL_SPILL] compile-time option.
 ** </dl>
 */
 #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
@@ -2040,10 +2129,19 @@ struct sqlite3_mem_methods {
 #define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
 #define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
-#define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
-#define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */
+#define SQLITE_CONFIG_PCACHE       14  /* no-op */
+#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
 #define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
 #define SQLITE_CONFIG_URI          17  /* int */
+#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
+#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
+#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
+#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
+#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
+#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
+#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
+#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
+#define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
 
 /*
 ** CAPI3REF: Database Connection Configuration Options
@@ -2101,38 +2199,74 @@ struct sqlite3_mem_methods {
 ** following this call.  The second parameter may be a NULL pointer, in
 ** which case the trigger setting is not reported back. </dd>
 **
+** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
+** <dd> ^This option is used to enable or disable the two-argument
+** version of the [fts3_tokenizer()] function which is part of the
+** [FTS3] full-text search engine extension.
+** There should be two additional arguments.
+** The first argument is an integer which is 0 to disable fts3_tokenizer() or
+** positive to enable fts3_tokenizer() or negative to leave the setting
+** unchanged.
+** The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
+** following this call.  The second parameter may be a NULL pointer, in
+** which case the new setting is not reported back. </dd>
+**
+** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
+** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
+** interface independently of the [load_extension()] SQL function.
+** The [sqlite3_enable_load_extension()] API enables or disables both the
+** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
+** There should be two additional arguments.
+** When the first argument to this interface is 1, then only the C-API is
+** enabled and the SQL function remains disabled.  If the first argument to
+** this interface is 0, then both the C-API and the SQL function are disabled.
+** If the first argument is -1, then no changes are made to state of either the
+** C-API or the SQL function.
+** The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
+** is disabled or enabled following this call.  The second parameter may
+** be a NULL pointer, in which case the new setting is not reported back.
+** </dd>
+**
 ** </dl>
 */
-#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
-#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
-#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
+#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
+#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
 
 
 /*
 ** CAPI3REF: Enable Or Disable Extended Result Codes
+** METHOD: sqlite3
 **
 ** ^The sqlite3_extended_result_codes() routine enables or disables the
 ** [extended result codes] feature of SQLite. ^The extended result
 ** codes are disabled by default for historical compatibility.
 */
-SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff);
 
 /*
 ** CAPI3REF: Last Insert Rowid
+** METHOD: sqlite3
 **
-** ^Each entry in an SQLite table has a unique 64-bit signed
+** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
+** has a unique 64-bit signed
 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
 ** names are not also used by explicitly declared columns. ^If
 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
 ** is another alias for the rowid.
 **
-** ^This routine returns the [rowid] of the most recent
-** successful [INSERT] into the database from the [database connection]
-** in the first argument.  ^As of SQLite version 3.7.7, this routines
-** records the last insert rowid of both ordinary tables and [virtual tables].
-** ^If no successful [INSERT]s
-** have ever occurred on that database connection, zero is returned.
+** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 
+** most recent successful [INSERT] into a rowid table or [virtual table]
+** on database connection D.
+** ^Inserts into [WITHOUT ROWID] tables are not recorded.
+** ^If no successful [INSERT]s into rowid tables
+** have ever occurred on the database connection D, 
+** then sqlite3_last_insert_rowid(D) returns zero.
 **
 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
 ** method, then this routine will return the [rowid] of the inserted
@@ -2164,52 +2298,51 @@ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
 ** unpredictable and might not equal either the old or the new
 ** last insert [rowid].
 */
-SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*);
 
 /*
 ** CAPI3REF: Count The Number Of Rows Modified
+** METHOD: sqlite3
+**
+** ^This function returns the number of rows modified, inserted or
+** deleted by the most recently completed INSERT, UPDATE or DELETE
+** statement on the database connection specified by the only parameter.
+** ^Executing any other type of SQL statement does not modify the value
+** returned by this function.
 **
-** ^This function returns the number of database rows that were changed
-** or inserted or deleted by the most recently completed SQL statement
-** on the [database connection] specified by the first parameter.
-** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
-** or [DELETE] statement are counted.  Auxiliary changes caused by
-** triggers or [foreign key actions] are not counted.)^ Use the
-** [sqlite3_total_changes()] function to find the total number of changes
-** including changes caused by triggers and foreign key actions.
-**
-** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
-** are not counted.  Only real table changes are counted.
-**
-** ^(A "row change" is a change to a single row of a single table
-** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
-** are changed as side effects of [REPLACE] constraint resolution,
-** rollback, ABORT processing, [DROP TABLE], or by any other
-** mechanisms do not count as direct row changes.)^
-**
-** A "trigger context" is a scope of execution that begins and
-** ends with the script of a [CREATE TRIGGER | trigger]. 
-** Most SQL statements are
-** evaluated outside of any trigger.  This is the "top level"
-** trigger context.  If a trigger fires from the top level, a
-** new trigger context is entered for the duration of that one
-** trigger.  Subtriggers create subcontexts for their duration.
-**
-** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
-** not create a new trigger context.
-**
-** ^This function returns the number of direct row changes in the
-** most recent INSERT, UPDATE, or DELETE statement within the same
-** trigger context.
-**
-** ^Thus, when called from the top level, this function returns the
-** number of changes in the most recent INSERT, UPDATE, or DELETE
-** that also occurred at the top level.  ^(Within the body of a trigger,
-** the sqlite3_changes() interface can be called to find the number of
-** changes in the most recently completed INSERT, UPDATE, or DELETE
-** statement within the body of the same trigger.
-** However, the number returned does not include changes
-** caused by subtriggers since those have their own context.)^
+** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
+** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 
+** [foreign key actions] or [REPLACE] constraint resolution are not counted.
+** 
+** Changes to a view that are intercepted by 
+** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 
+** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 
+** DELETE statement run on a view is always zero. Only changes made to real 
+** tables are counted.
+**
+** Things are more complicated if the sqlite3_changes() function is
+** executed while a trigger program is running. This may happen if the
+** program uses the [changes() SQL function], or if some other callback
+** function invokes sqlite3_changes() directly. Essentially:
+** 
+** <ul>
+**   <li> ^(Before entering a trigger program the value returned by
+**        sqlite3_changes() function is saved. After the trigger program 
+**        has finished, the original value is restored.)^
+** 
+**   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 
+**        statement sets the value returned by sqlite3_changes() 
+**        upon completion as normal. Of course, this value will not include 
+**        any changes performed by sub-triggers, as the sqlite3_changes() 
+**        value will be saved and restored after each sub-trigger has run.)^
+** </ul>
+** 
+** ^This means that if the changes() SQL function (or similar) is used
+** by the first INSERT, UPDATE or DELETE statement within a trigger, it 
+** returns the value as set when the calling statement began executing.
+** ^If it is used by the second or subsequent such statement within a trigger 
+** program, the value returned reflects the number of rows modified by the 
+** previous INSERT, UPDATE or DELETE statement within the same trigger.
 **
 ** See also the [sqlite3_total_changes()] interface, the
 ** [count_changes pragma], and the [changes() SQL function].
@@ -2218,25 +2351,23 @@ SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
 ** while [sqlite3_changes()] is running then the value returned
 ** is unpredictable and not meaningful.
 */
-SQLITE_API int sqlite3_changes(sqlite3*);
+SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*);
 
 /*
 ** CAPI3REF: Total Number Of Rows Modified
+** METHOD: sqlite3
 **
-** ^This function returns the number of row changes caused by [INSERT],
-** [UPDATE] or [DELETE] statements since the [database connection] was opened.
-** ^(The count returned by sqlite3_total_changes() includes all changes
-** from all [CREATE TRIGGER | trigger] contexts and changes made by
-** [foreign key actions]. However,
-** the count does not include changes used to implement [REPLACE] constraints,
-** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
-** count does not include rows of views that fire an [INSTEAD OF trigger],
-** though if the INSTEAD OF trigger makes changes of its own, those changes 
-** are counted.)^
-** ^The sqlite3_total_changes() function counts the changes as soon as
-** the statement that makes them is completed (when the statement handle
-** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
-**
+** ^This function returns the total number of rows inserted, modified or
+** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
+** since the database connection was opened, including those executed as
+** part of trigger programs. ^Executing any other type of SQL statement
+** does not affect the value returned by sqlite3_total_changes().
+** 
+** ^Changes made as part of [foreign key actions] are included in the
+** count, but those made as part of REPLACE constraint resolution are
+** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 
+** are not counted.
+** 
 ** See also the [sqlite3_changes()] interface, the
 ** [count_changes pragma], and the [total_changes() SQL function].
 **
@@ -2244,10 +2375,11 @@ SQLITE_API int sqlite3_changes(sqlite3*);
 ** while [sqlite3_total_changes()] is running then the value
 ** returned is unpredictable and not meaningful.
 */
-SQLITE_API int sqlite3_total_changes(sqlite3*);
+SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*);
 
 /*
 ** CAPI3REF: Interrupt A Long-Running Query
+** METHOD: sqlite3
 **
 ** ^This function causes any pending database operation to abort and
 ** return at its earliest opportunity. This routine is typically
@@ -2283,7 +2415,7 @@ SQLITE_API int sqlite3_total_changes(sqlite3*);
 ** If the database connection closes while [sqlite3_interrupt()]
 ** is running then bad things will likely happen.
 */
-SQLITE_API void sqlite3_interrupt(sqlite3*);
+SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*);
 
 /*
 ** CAPI3REF: Determine If An SQL Statement Is Complete
@@ -2318,33 +2450,41 @@ SQLITE_API void sqlite3_interrupt(sqlite3*);
 ** The input to [sqlite3_complete16()] must be a zero-terminated
 ** UTF-16 string in native byte order.
 */
-SQLITE_API int sqlite3_complete(const char *sql);
-SQLITE_API int sqlite3_complete16(const void *sql);
+SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql);
+SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql);
 
 /*
 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
-**
-** ^This routine sets a callback function that might be invoked whenever
-** an attempt is made to open a database table that another thread
-** or process has locked.
-**
-** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
+** KEYWORDS: {busy-handler callback} {busy handler}
+** METHOD: sqlite3
+**
+** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
+** that might be invoked with argument P whenever
+** an attempt is made to access a database table associated with
+** [database connection] D when another thread
+** or process has the table locked.
+** The sqlite3_busy_handler() interface is used to implement
+** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
+**
+** ^If the busy callback is NULL, then [SQLITE_BUSY]
 ** is returned immediately upon encountering the lock.  ^If the busy callback
 ** is not NULL, then the callback might be invoked with two arguments.
 **
 ** ^The first argument to the busy handler is a copy of the void* pointer which
 ** is the third argument to sqlite3_busy_handler().  ^The second argument to
 ** the busy handler callback is the number of times that the busy handler has
-** been invoked for this locking event.  ^If the
+** been invoked previously for the same locking event.  ^If the
 ** busy callback returns 0, then no additional attempts are made to
-** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
+** access the database and [SQLITE_BUSY] is returned
+** to the application.
 ** ^If the callback returns non-zero, then another attempt
-** is made to open the database for reading and the cycle repeats.
+** is made to access the database and the cycle repeats.
 **
 ** The presence of a busy handler does not guarantee that it will be invoked
 ** when there is lock contention. ^If SQLite determines that invoking the busy
 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
-** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
+** to the application instead of invoking the 
+** busy handler.
 ** Consider a scenario where one process is holding a read lock that
 ** it is trying to promote to a reserved lock and
 ** a second process is holding a reserved lock that it is trying
@@ -2358,57 +2498,48 @@ SQLITE_API int sqlite3_complete16(const void *sql);
 **
 ** ^The default busy callback is NULL.
 **
-** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
-** when SQLite is in the middle of a large transaction where all the
-** changes will not fit into the in-memory cache.  SQLite will
-** already hold a RESERVED lock on the database file, but it needs
-** to promote this lock to EXCLUSIVE so that it can spill cache
-** pages into the database file without harm to concurrent
-** readers.  ^If it is unable to promote the lock, then the in-memory
-** cache will be left in an inconsistent state and so the error
-** code is promoted from the relatively benign [SQLITE_BUSY] to
-** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
-** forces an automatic rollback of the changes.  See the
-** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
-** CorruptionFollowingBusyError</a> wiki page for a discussion of why
-** this is important.
-**
 ** ^(There can only be a single busy handler defined for each
 ** [database connection].  Setting a new busy handler clears any
 ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
-** will also set or clear the busy handler.
+** or evaluating [PRAGMA busy_timeout=N] will change the
+** busy handler and thus clear any previously set busy handler.
 **
 ** The busy callback should not take any actions which modify the
-** database connection that invoked the busy handler.  Any such actions
+** database connection that invoked the busy handler.  In other words,
+** the busy handler is not reentrant.  Any such actions
 ** result in undefined behavior.
 ** 
 ** A busy handler must not close the database connection
 ** or [prepared statement] that invoked the busy handler.
 */
-SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
 
 /*
 ** CAPI3REF: Set A Busy Timeout
+** METHOD: sqlite3
 **
 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
 ** for a specified amount of time when a table is locked.  ^The handler
 ** will sleep multiple times until at least "ms" milliseconds of sleeping
 ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
 ** the handler returns 0 which causes [sqlite3_step()] to return
-** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
+** [SQLITE_BUSY].
 **
 ** ^Calling this routine with an argument less than or equal to zero
 ** turns off all busy handlers.
 **
 ** ^(There can only be a single busy handler for a particular
-** [database connection] any any given moment.  If another busy handler
+** [database connection] at any given moment.  If another busy handler
 ** was defined  (using [sqlite3_busy_handler()]) prior to calling
 ** this routine, that other busy handler is cleared.)^
+**
+** See also:  [PRAGMA busy_timeout]
 */
-SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms);
 
 /*
 ** CAPI3REF: Convenience Routines For Running Queries
+** METHOD: sqlite3
 **
 ** This is a legacy interface that is preserved for backwards compatibility.
 ** Use of this interface is not recommended.
@@ -2479,7 +2610,7 @@ SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
 ** reflected in subsequent calls to [sqlite3_errcode()] or
 ** [sqlite3_errmsg()].
 */
-SQLITE_API int sqlite3_get_table(
+SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
   sqlite3 *db,          /* An open database */
   const char *zSql,     /* SQL to be evaluated */
   char ***pazResult,    /* Results of the query */
@@ -2487,13 +2618,17 @@ SQLITE_API int sqlite3_get_table(
   int *pnColumn,        /* Number of result columns written here */
   char **pzErrmsg       /* Error msg written here */
 );
-SQLITE_API void sqlite3_free_table(char **result);
+SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result);
 
 /*
 ** CAPI3REF: Formatted String Printing Functions
 **
 ** These routines are work-alikes of the "printf()" family of functions
 ** from the standard C library.
+** These routines understand most of the common K&R formatting options,
+** plus some additional non-standard formats, detailed below.
+** Note that some of the more obscure formatting options from recent
+** C-library standards are omitted from this implementation.
 **
 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
 ** results into memory obtained from [sqlite3_malloc()].
@@ -2526,9 +2661,9 @@ SQLITE_API void sqlite3_free_table(char **result);
 ** These routines all implement some additional formatting
 ** options that are useful for constructing SQL statements.
 ** All of the usual printf() formatting options apply.  In addition, there
-** is are "%q", "%Q", and "%z" options.
+** is are "%q", "%Q", "%w" and "%z" options.
 **
-** ^(The %q option works like %s in that it substitutes a null-terminated
+** ^(The %q option works like %s in that it substitutes a nul-terminated
 ** string from the argument list.  But %q also doubles every '\'' character.
 ** %q is designed for use inside a string literal.)^  By doubling each '\''
 ** character it escapes that character and allows it to be inserted into
@@ -2579,14 +2714,20 @@ SQLITE_API void sqlite3_free_table(char **result);
 ** The code above will render a correct SQL statement in the zSQL
 ** variable even if the zText variable is a NULL pointer.
 **
+** ^(The "%w" formatting option is like "%q" except that it expects to
+** be contained within double-quotes instead of single quotes, and it
+** escapes the double-quote character instead of the single-quote
+** character.)^  The "%w" formatting option is intended for safely inserting
+** table and column names into a constructed SQL statement.
+**
 ** ^(The "%z" formatting option works like "%s" but with the
 ** addition that after the string has been read and copied into
 ** the result, [sqlite3_free()] is called on the input string.)^
 */
-SQLITE_API char *sqlite3_mprintf(const char*,...);
-SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
-SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
-SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
+SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...);
+SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list);
+SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...);
+SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list);
 
 /*
 ** CAPI3REF: Memory Allocation Subsystem
@@ -2603,6 +2744,10 @@ SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
 ** a NULL pointer.
 **
+** ^The sqlite3_malloc64(N) routine works just like
+** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
+** of a signed 32-bit integer.
+**
 ** ^Calling sqlite3_free() with a pointer previously returned
 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
 ** that it might be reused.  ^The sqlite3_free() routine is
@@ -2614,24 +2759,38 @@ SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
 ** might result if sqlite3_free() is called with a non-NULL pointer that
 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
 **
-** ^(The sqlite3_realloc() interface attempts to resize a
-** prior memory allocation to be at least N bytes, where N is the
-** second parameter.  The memory allocation to be resized is the first
-** parameter.)^ ^ If the first parameter to sqlite3_realloc()
+** ^The sqlite3_realloc(X,N) interface attempts to resize a
+** prior memory allocation X to be at least N bytes.
+** ^If the X parameter to sqlite3_realloc(X,N)
 ** is a NULL pointer then its behavior is identical to calling
-** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
-** ^If the second parameter to sqlite3_realloc() is zero or
+** sqlite3_malloc(N).
+** ^If the N parameter to sqlite3_realloc(X,N) is zero or
 ** negative then the behavior is exactly the same as calling
-** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
-** ^sqlite3_realloc() returns a pointer to a memory allocation
-** of at least N bytes in size or NULL if sufficient memory is unavailable.
+** sqlite3_free(X).
+** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
+** of at least N bytes in size or NULL if insufficient memory is available.
 ** ^If M is the size of the prior allocation, then min(N,M) bytes
 ** of the prior allocation are copied into the beginning of buffer returned
-** by sqlite3_realloc() and the prior allocation is freed.
-** ^If sqlite3_realloc() returns NULL, then the prior allocation
-** is not freed.
-**
-** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
+** by sqlite3_realloc(X,N) and the prior allocation is freed.
+** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
+** prior allocation is not freed.
+**
+** ^The sqlite3_realloc64(X,N) interfaces works the same as
+** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
+** of a 32-bit signed integer.
+**
+** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
+** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
+** sqlite3_msize(X) returns the size of that memory allocation in bytes.
+** ^The value returned by sqlite3_msize(X) might be larger than the number
+** of bytes requested when X was allocated.  ^If X is a NULL pointer then
+** sqlite3_msize(X) returns zero.  If X points to something that is not
+** the beginning of memory allocation, or if it points to a formerly
+** valid memory allocation that has now been freed, then the behavior
+** of sqlite3_msize(X) is undefined and possibly harmful.
+**
+** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
+** sqlite3_malloc64(), and sqlite3_realloc64()
 ** is always aligned to at least an 8 byte boundary, or to a
 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
 ** option is used.
@@ -2641,12 +2800,12 @@ SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
 ** implementation of these routines to be omitted.  That capability
 ** is no longer provided.  Only built-in memory allocators can be used.
 **
-** The Windows OS interface layer calls
+** Prior to SQLite version 3.7.10, the Windows OS interface layer called
 ** the system malloc() and free() directly when converting
 ** filenames between the UTF-8 encoding used by SQLite
 ** and whatever filename encoding is used by the particular Windows
-** installation.  Memory allocation errors are detected, but
-** they are reported back as [SQLITE_CANTOPEN] or
+** installation.  Memory allocation errors were detected, but
+** they were reported back as [SQLITE_CANTOPEN] or
 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
 **
 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
@@ -2658,9 +2817,12 @@ SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
 ** a block of memory after it has been released using
 ** [sqlite3_free()] or [sqlite3_realloc()].
 */
-SQLITE_API void *sqlite3_malloc(int);
-SQLITE_API void *sqlite3_realloc(void*, int);
-SQLITE_API void sqlite3_free(void*);
+SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int);
+SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64);
+SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int);
+SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64);
+SQLITE_API void SQLITE_STDCALL sqlite3_free(void*);
+SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*);
 
 /*
 ** CAPI3REF: Memory Allocator Statistics
@@ -2685,8 +2847,8 @@ SQLITE_API void sqlite3_free(void*);
 ** by [sqlite3_memory_highwater(1)] is the high-water mark
 ** prior to the reset.
 */
-SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
-SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag);
 
 /*
 ** CAPI3REF: Pseudo-Random Number Generator
@@ -2698,18 +2860,22 @@ SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
 ** applications to access the same PRNG for other purposes.
 **
 ** ^A call to this routine stores N bytes of randomness into buffer P.
-**
-** ^The first time this routine is invoked (either internally or by
-** the application) the PRNG is seeded using randomness obtained
-** from the xRandomness method of the default [sqlite3_vfs] object.
-** ^On all subsequent invocations, the pseudo-randomness is generated
+** ^The P parameter can be a NULL pointer.
+**
+** ^If this routine has not been previously called or if the previous
+** call had N less than one or a NULL pointer for P, then the PRNG is
+** seeded using randomness obtained from the xRandomness method of
+** the default [sqlite3_vfs] object.
+** ^If the previous call to this routine had an N of 1 or more and a
+** non-NULL P then the pseudo-randomness is generated
 ** internally and without recourse to the [sqlite3_vfs] xRandomness
 ** method.
 */
-SQLITE_API void sqlite3_randomness(int N, void *P);
+SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P);
 
 /*
 ** CAPI3REF: Compile-Time Authorization Callbacks
+** METHOD: sqlite3
 **
 ** ^This routine registers an authorizer callback with a particular
 ** [database connection], supplied in the first argument.
@@ -2788,7 +2954,7 @@ SQLITE_API void sqlite3_randomness(int N, void *P);
 ** as stated in the previous paragraph, sqlite3_step() invokes
 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
 */
-SQLITE_API int sqlite3_set_authorizer(
+SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
   sqlite3*,
   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
   void *pUserData
@@ -2803,8 +2969,8 @@ SQLITE_API int sqlite3_set_authorizer(
 ** [sqlite3_set_authorizer | authorizer documentation] for additional
 ** information.
 **
-** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
-** from the [sqlite3_vtab_on_conflict()] interface.
+** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
+** returned from the [sqlite3_vtab_on_conflict()] interface.
 */
 #define SQLITE_DENY   1   /* Abort the SQL statement with an error */
 #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
@@ -2862,9 +3028,14 @@ SQLITE_API int sqlite3_set_authorizer(
 #define SQLITE_FUNCTION             31   /* NULL            Function Name   */
 #define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
 #define SQLITE_COPY                  0   /* No longer used */
+#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
 
 /*
 ** CAPI3REF: Tracing And Profiling Functions
+** METHOD: sqlite3
+**
+** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
+** instead of the routines described here.
 **
 ** These routines register callback functions that can be used for
 ** tracing and profiling the execution of SQL statements.
@@ -2877,6 +3048,9 @@ SQLITE_API int sqlite3_set_authorizer(
 ** as each triggered subprogram is entered.  The callbacks for triggers
 ** contain a UTF-8 SQL comment that identifies the trigger.)^
 **
+** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
+** the length of [bound parameter] expansion in the output of sqlite3_trace().
+**
 ** ^The callback function registered by sqlite3_profile() is invoked
 ** as each SQL statement finishes.  ^The profile callback contains
 ** the original statement text and an estimate of wall-clock time
@@ -2888,12 +3062,107 @@ SQLITE_API int sqlite3_set_authorizer(
 ** sqlite3_profile() function is considered experimental and is
 ** subject to change in future versions of SQLite.
 */
-SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
-SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
+SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_trace(sqlite3*,
+   void(*xTrace)(void*,const char*), void*);
+SQLITE_API SQLITE_DEPRECATED void *SQLITE_STDCALL sqlite3_profile(sqlite3*,
    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
 
 /*
+** CAPI3REF: SQL Trace Event Codes
+** KEYWORDS: SQLITE_TRACE
+**
+** These constants identify classes of events that can be monitored
+** using the [sqlite3_trace_v2()] tracing logic.  The third argument
+** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of
+** the following constants.  ^The first argument to the trace callback
+** is one of the following constants.
+**
+** New tracing constants may be added in future releases.
+**
+** ^A trace callback has four arguments: xCallback(T,C,P,X).
+** ^The T argument is one of the integer type codes above.
+** ^The C argument is a copy of the context pointer passed in as the
+** fourth argument to [sqlite3_trace_v2()].
+** The P and X arguments are pointers whose meanings depend on T.
+**
+** <dl>
+** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
+** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
+** first begins running and possibly at other times during the
+** execution of the prepared statement, such as at the start of each
+** trigger subprogram. ^The P argument is a pointer to the
+** [prepared statement]. ^The X argument is a pointer to a string which
+** is the unexpanded SQL text of the prepared statement or an SQL comment 
+** that indicates the invocation of a trigger.  ^The callback can compute
+** the same text that would have been returned by the legacy [sqlite3_trace()]
+** interface by using the X argument when X begins with "--" and invoking
+** [sqlite3_expanded_sql(P)] otherwise.
+**
+** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
+** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
+** information as is provided by the [sqlite3_profile()] callback.
+** ^The P argument is a pointer to the [prepared statement] and the
+** X argument points to a 64-bit integer which is the estimated of
+** the number of nanosecond that the prepared statement took to run.
+** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
+**
+** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
+** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
+** statement generates a single row of result.  
+** ^The P argument is a pointer to the [prepared statement] and the
+** X argument is unused.
+**
+** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
+** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
+** connection closes.
+** ^The P argument is a pointer to the [database connection] object
+** and the X argument is unused.
+** </dl>
+*/
+#define SQLITE_TRACE_STMT       0x01
+#define SQLITE_TRACE_PROFILE    0x02
+#define SQLITE_TRACE_ROW        0x04
+#define SQLITE_TRACE_CLOSE      0x08
+
+/*
+** CAPI3REF: SQL Trace Hook
+** METHOD: sqlite3
+**
+** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
+** function X against [database connection] D, using property mask M
+** and context pointer P.  ^If the X callback is
+** NULL or if the M mask is zero, then tracing is disabled.  The
+** M argument should be the bitwise OR-ed combination of
+** zero or more [SQLITE_TRACE] constants.
+**
+** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 
+** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
+**
+** ^The X callback is invoked whenever any of the events identified by 
+** mask M occur.  ^The integer return value from the callback is currently
+** ignored, though this may change in future releases.  Callback
+** implementations should return zero to ensure future compatibility.
+**
+** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
+** ^The T argument is one of the [SQLITE_TRACE]
+** constants to indicate why the callback was invoked.
+** ^The C argument is a copy of the context pointer.
+** The P and X arguments are pointers whose meanings depend on T.
+**
+** The sqlite3_trace_v2() interface is intended to replace the legacy
+** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
+** are deprecated.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_trace_v2(
+  sqlite3*,
+  unsigned uMask,
+  int(*xCallback)(unsigned,void*,void*,void*),
+  void *pCtx
+);
+
+/*
 ** CAPI3REF: Query Progress Callbacks
+** METHOD: sqlite3
 **
 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
 ** function X to be invoked periodically during long running calls to
@@ -2902,9 +3171,10 @@ SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
 ** interface is to keep a GUI updated during a large query.
 **
 ** ^The parameter P is passed through as the only parameter to the 
-** callback function X.  ^The parameter N is the number of 
+** callback function X.  ^The parameter N is the approximate number of 
 ** [virtual machine instructions] that are evaluated between successive
-** invocations of the callback X.
+** invocations of the callback X.  ^If N is less than one then the progress
+** handler is disabled.
 **
 ** ^Only a single progress handler may be defined at one time per
 ** [database connection]; setting a new progress handler cancels the
@@ -2922,10 +3192,11 @@ SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
 ** database connections for the meaning of "modify" in this paragraph.
 **
 */
-SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
+SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 
 /*
 ** CAPI3REF: Opening A New Database Connection
+** CONSTRUCTOR: sqlite3
 **
 ** ^These routines open an SQLite database file as specified by the 
 ** filename argument. ^The filename argument is interpreted as UTF-8 for
@@ -2940,9 +3211,9 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 ** an English language description of the error following a failure of any
 ** of the sqlite3_open() routines.
 **
-** ^The default encoding for the database will be UTF-8 if
-** sqlite3_open() or sqlite3_open_v2() is called and
-** UTF-16 in the native byte order if sqlite3_open16() is used.
+** ^The default encoding will be UTF-8 for databases created using
+** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases
+** created using sqlite3_open16() will be UTF-16 in the native byte order.
 **
 ** Whether or not an error occurs when it is opened, resources
 ** associated with the [database connection] handle should be released by
@@ -3030,13 +3301,14 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 ** then it is interpreted as an absolute path. ^If the path does not begin 
 ** with a '/' (meaning that the authority section is omitted from the URI)
 ** then the path is interpreted as a relative path. 
-** ^On windows, the first component of an absolute path 
-** is a drive specification (e.g. "C:").
+** ^(On windows, the first component of an absolute path 
+** is a drive specification (e.g. "C:").)^
 **
 ** [[core URI query parameters]]
 ** The query component of a URI may contain parameters that are interpreted
 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
-** SQLite interprets the following three query parameters:
+** SQLite and its built-in [VFSes] interpret the
+** following query parameters:
 **
 ** <ul>
 **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
@@ -3047,18 +3319,20 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **     present, then the VFS specified by the option takes precedence over
 **     the value passed as the fourth parameter to sqlite3_open_v2().
 **
-**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or
-**     "rwc". Attempting to set it to any other value is an error)^. 
+**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
+**     "rwc", or "memory". Attempting to set it to any other value is
+**     an error)^. 
 **     ^If "ro" is specified, then the database is opened for read-only 
 **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 
-**     third argument to sqlite3_prepare_v2(). ^If the mode option is set to 
+**     third argument to sqlite3_open_v2(). ^If the mode option is set to 
 **     "rw", then the database is opened for read-write (but not create) 
 **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 
 **     been set. ^Value "rwc" is equivalent to setting both 
-**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is 
-**     used, it is an error to specify a value for the mode parameter that is 
-**     less restrictive than that specified by the flags passed as the third 
-**     parameter.
+**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
+**     set to "memory" then a pure [in-memory database] that never reads
+**     or writes from disk is used. ^It is an error to specify a value for
+**     the mode parameter that is less restrictive than that specified by
+**     the flags passed in the third parameter to sqlite3_open_v2().
 **
 **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
 **     "private". ^Setting it to "shared" is equivalent to setting the
@@ -3066,8 +3340,30 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is 
 **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
 **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
-**     a URI filename, its value overrides any behaviour requested by setting
+**     a URI filename, its value overrides any behavior requested by setting
 **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
+**
+**  <li> <b>psow</b>: ^The psow parameter indicates whether or not the
+**     [powersafe overwrite] property does or does not apply to the
+**     storage media on which the database file resides.
+**
+**  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
+**     which if set disables file locking in rollback journal modes.  This
+**     is useful for accessing a database on a filesystem that does not
+**     support locking.  Caution:  Database corruption might result if two
+**     or more processes write to the same database and any one of those
+**     processes uses nolock=1.
+**
+**  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
+**     parameter that indicates that the database file is stored on
+**     read-only media.  ^When immutable is set, SQLite assumes that the
+**     database file cannot be changed, even by a process with higher
+**     privilege, and so the database is opened read-only and all locking
+**     and change detection is disabled.  Caution: Setting the immutable
+**     property on a database file that does in fact change can result
+**     in incorrect query results and/or [SQLITE_CORRUPT] errors.
+**     See also: [SQLITE_IOCAP_IMMUTABLE].
+**       
 ** </ul>
 **
 ** ^Specifying an unknown parameter in the query component of a URI is not an
@@ -3097,8 +3393,9 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **          Open file "data.db" in the current directory for read-only access.
 **          Regardless of whether or not shared-cache mode is enabled by
 **          default, use a private cache.
-** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
-**          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
+** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
+**          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
+**          that uses dot-files in place of posix advisory locking.
 ** <tr><td> file:data.db?mode=readonly <td> 
 **          An error. "readonly" is not a valid option for the "mode" parameter.
 ** </table>
@@ -3117,16 +3414,22 @@ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 ** codepage is currently defined.  Filenames containing international
 ** characters must be converted to UTF-8 prior to passing them into
 ** sqlite3_open() or sqlite3_open_v2().
+**
+** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
+** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
+** features that require the use of temporary files may fail.
+**
+** See also: [sqlite3_temp_directory]
 */
-SQLITE_API int sqlite3_open(
+SQLITE_API int SQLITE_STDCALL sqlite3_open(
   const char *filename,   /* Database filename (UTF-8) */
   sqlite3 **ppDb          /* OUT: SQLite db handle */
 );
-SQLITE_API int sqlite3_open16(
+SQLITE_API int SQLITE_STDCALL sqlite3_open16(
   const void *filename,   /* Database filename (UTF-16) */
   sqlite3 **ppDb          /* OUT: SQLite db handle */
 );
-SQLITE_API int sqlite3_open_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
   const char *filename,   /* Database filename (UTF-8) */
   sqlite3 **ppDb,         /* OUT: SQLite db handle */
   int flags,              /* Flags */
@@ -3136,31 +3439,58 @@ SQLITE_API int sqlite3_open_v2(
 /*
 ** CAPI3REF: Obtain Values For URI Parameters
 **
-** This is a utility routine, useful to VFS implementations, that checks
+** These are utility routines, useful to VFS implementations, that check
 ** to see if a database file was a URI that contained a specific query 
-** parameter, and if so obtains the value of the query parameter.
-**
-** The zFilename argument is the filename pointer passed into the xOpen()
-** method of a VFS implementation.  The zParam argument is the name of the
-** query parameter we seek.  This routine returns the value of the zParam
-** parameter if it exists.  If the parameter does not exist, this routine
-** returns a NULL pointer.
-**
-** If the zFilename argument to this function is not a pointer that SQLite
-** passed into the xOpen VFS method, then the behavior of this routine
-** is undefined and probably undesirable.
+** parameter, and if so obtains the value of that query parameter.
+**
+** If F is the database filename pointer passed into the xOpen() method of 
+** a VFS implementation when the flags parameter to xOpen() has one or 
+** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
+** P is the name of the query parameter, then
+** sqlite3_uri_parameter(F,P) returns the value of the P
+** parameter if it exists or a NULL pointer if P does not appear as a 
+** query parameter on F.  If P is a query parameter of F
+** has no explicit value, then sqlite3_uri_parameter(F,P) returns
+** a pointer to an empty string.
+**
+** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
+** parameter and returns true (1) or false (0) according to the value
+** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
+** value of query parameter P is one of "yes", "true", or "on" in any
+** case or if the value begins with a non-zero number.  The 
+** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
+** query parameter P is one of "no", "false", or "off" in any case or
+** if the value begins with a numeric zero.  If P is not a query
+** parameter on F or if the value of P is does not match any of the
+** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
+**
+** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
+** 64-bit signed integer and returns that integer, or D if P does not
+** exist.  If the value of P is something other than an integer, then
+** zero is returned.
+** 
+** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
+** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
+** is not a database file pathname pointer that SQLite passed into the xOpen
+** VFS method, then the behavior of this routine is undefined and probably
+** undesirable.
 */
-SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam);
+SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
 
 
 /*
 ** CAPI3REF: Error Codes And Messages
-**
-** ^The sqlite3_errcode() interface returns the numeric [result code] or
-** [extended result code] for the most recent failed sqlite3_* API call
-** associated with a [database connection]. If a prior API call failed
-** but the most recent API call succeeded, the return value from
-** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
+** METHOD: sqlite3
+**
+** ^If the most recent sqlite3_* API call associated with 
+** [database connection] D failed, then the sqlite3_errcode(D) interface
+** returns the numeric [result code] or [extended result code] for that
+** API call.
+** If the most recent API call was successful,
+** then the return value from sqlite3_errcode() is undefined.
+** ^The sqlite3_extended_errcode()
 ** interface is the same except that it always returns the 
 ** [extended result code] even when extended result codes are
 ** disabled.
@@ -3172,6 +3502,11 @@ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *
 ** However, the error string might be overwritten or deallocated by
 ** subsequent calls to other SQLite interface functions.)^
 **
+** ^The sqlite3_errstr() interface returns the English-language text
+** that describes the [result code], as UTF-8.
+** ^(Memory to hold the error message string is managed internally
+** and must not be freed by the application)^.
+**
 ** When the serialized [threading mode] is in use, it might be the
 ** case that a second error occurs on a separate thread in between
 ** the time of the first error and the call to these interfaces.
@@ -3186,39 +3521,41 @@ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *
 ** was invoked incorrectly by the application.  In that case, the
 ** error code and message may or may not be set.
 */
-SQLITE_API int sqlite3_errcode(sqlite3 *db);
-SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
-SQLITE_API const char *sqlite3_errmsg(sqlite3*);
-SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
+SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db);
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int);
 
 /*
-** CAPI3REF: SQL Statement Object
+** CAPI3REF: Prepared Statement Object
 ** KEYWORDS: {prepared statement} {prepared statements}
 **
-** An instance of this object represents a single SQL statement.
-** This object is variously known as a "prepared statement" or a
-** "compiled SQL statement" or simply as a "statement".
+** An instance of this object represents a single SQL statement that
+** has been compiled into binary form and is ready to be evaluated.
 **
-** The life of a statement object goes something like this:
+** Think of each SQL statement as a separate computer program.  The
+** original SQL text is source code.  A prepared statement object 
+** is the compiled object code.  All SQL must be converted into a
+** prepared statement before it can be run.
+**
+** The life-cycle of a prepared statement object usually goes like this:
 **
 ** <ol>
-** <li> Create the object using [sqlite3_prepare_v2()] or a related
-**      function.
-** <li> Bind values to [host parameters] using the sqlite3_bind_*()
+** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
+** <li> Bind values to [parameters] using the sqlite3_bind_*()
 **      interfaces.
 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
-** <li> Reset the statement using [sqlite3_reset()] then go back
+** <li> Reset the prepared statement using [sqlite3_reset()] then go back
 **      to step 2.  Do this zero or more times.
 ** <li> Destroy the object using [sqlite3_finalize()].
 ** </ol>
-**
-** Refer to documentation on individual methods above for additional
-** information.
 */
 typedef struct sqlite3_stmt sqlite3_stmt;
 
 /*
 ** CAPI3REF: Run-time Limits
+** METHOD: sqlite3
 **
 ** ^(This interface allows the size of various constructs to be limited
 ** on a connection by connection basis.  The first parameter is the
@@ -3256,7 +3593,7 @@ typedef struct sqlite3_stmt sqlite3_stmt;
 **
 ** New run-time limit categories may be added in future releases.
 */
-SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
+SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal);
 
 /*
 ** CAPI3REF: Run-Time Limit Categories
@@ -3308,6 +3645,10 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 **
 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
 ** <dd>The maximum depth of recursion for triggers.</dd>)^
+**
+** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
+** <dd>The maximum number of auxiliary worker threads that a single
+** [prepared statement] may start.</dd>)^
 ** </dl>
 */
 #define SQLITE_LIMIT_LENGTH                    0
@@ -3321,10 +3662,13 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
 #define SQLITE_LIMIT_VARIABLE_NUMBER           9
 #define SQLITE_LIMIT_TRIGGER_DEPTH            10
+#define SQLITE_LIMIT_WORKER_THREADS           11
 
 /*
 ** CAPI3REF: Compiling An SQL Statement
 ** KEYWORDS: {SQL statement compiler}
+** METHOD: sqlite3
+** CONSTRUCTOR: sqlite3_stmt
 **
 ** To execute an SQL query, it must first be compiled into a byte-code
 ** program using one of these routines.
@@ -3338,16 +3682,14 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
 ** use UTF-16.
 **
-** ^If the nByte argument is less than zero, then zSql is read up to the
-** first zero terminator. ^If nByte is non-negative, then it is the maximum
-** number of  bytes read from zSql.  ^When nByte is non-negative, the
-** zSql string ends at either the first '\000' or '\u0000' character or
-** the nByte-th byte, whichever comes first. If the caller knows
-** that the supplied string is nul-terminated, then there is a small
-** performance advantage to be gained by passing an nByte parameter that
-** is equal to the number of bytes in the input string <i>including</i>
-** the nul-terminator bytes as this saves SQLite from having to
-** make a copy of the input string.
+** ^If the nByte argument is negative, then zSql is read up to the
+** first zero terminator. ^If nByte is positive, then it is the
+** number of bytes read from zSql.  ^If nByte is zero, then no prepared
+** statement is generated.
+** If the caller knows that the supplied string is nul-terminated, then
+** there is a small performance advantage to passing an nByte parameter that
+** is the number of bytes in the input string <i>including</i>
+** the nul-terminator.
 **
 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
 ** past the end of the first SQL statement in zSql.  These routines only
@@ -3377,7 +3719,8 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 ** <li>
 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
-** statement and try to run it again.
+** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
+** retries will occur before sqlite3_step() gives up and returns an error.
 ** </li>
 **
 ** <li>
@@ -3399,32 +3742,31 @@ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
 ** or [GLOB] operator or if the parameter is compared to an indexed column
 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
-** the 
 ** </li>
 ** </ol>
 */
-SQLITE_API int sqlite3_prepare(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare(
   sqlite3 *db,            /* Database handle */
   const char *zSql,       /* SQL statement, UTF-8 encoded */
   int nByte,              /* Maximum length of zSql in bytes. */
   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
 );
-SQLITE_API int sqlite3_prepare_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2(
   sqlite3 *db,            /* Database handle */
   const char *zSql,       /* SQL statement, UTF-8 encoded */
   int nByte,              /* Maximum length of zSql in bytes. */
   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
 );
-SQLITE_API int sqlite3_prepare16(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare16(
   sqlite3 *db,            /* Database handle */
   const void *zSql,       /* SQL statement, UTF-16 encoded */
   int nByte,              /* Maximum length of zSql in bytes. */
   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
 );
-SQLITE_API int sqlite3_prepare16_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2(
   sqlite3 *db,            /* Database handle */
   const void *zSql,       /* SQL statement, UTF-16 encoded */
   int nByte,              /* Maximum length of zSql in bytes. */
@@ -3434,15 +3776,41 @@ SQLITE_API int sqlite3_prepare16_v2(
 
 /*
 ** CAPI3REF: Retrieving Statement SQL
+** METHOD: sqlite3_stmt
+**
+** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
+** SQL text used to create [prepared statement] P if P was
+** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
+** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
+** string containing the SQL text of prepared statement P with
+** [bound parameters] expanded.
+**
+** ^(For example, if a prepared statement is created using the SQL
+** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
+** and parameter :xyz is unbound, then sqlite3_sql() will return
+** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
+** will return "SELECT 2345,NULL".)^
+**
+** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
+** is available to hold the result, or if the result would exceed the
+** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
 **
-** ^This interface can be used to retrieve a saved copy of the original
-** SQL text used to create a [prepared statement] if that statement was
-** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
+** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
+** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
+** option causes sqlite3_expanded_sql() to always return NULL.
+**
+** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
+** automatically freed when the prepared statement is finalized.
+** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
+** is obtained from [sqlite3_malloc()] and must be free by the application
+** by passing it to [sqlite3_free()].
 */
-SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt);
+SQLITE_API char *SQLITE_STDCALL sqlite3_expanded_sql(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Determine If An SQL Statement Writes The Database
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
 ** and only if the [prepared statement] X makes no direct changes to
@@ -3470,7 +3838,28 @@ SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
 ** change the configuration of a database connection, they do not make 
 ** changes to the content of the database files on disk.
 */
-SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
+
+/*
+** CAPI3REF: Determine If A Prepared Statement Has Been Reset
+** METHOD: sqlite3_stmt
+**
+** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
+** [prepared statement] S has been stepped at least once using 
+** [sqlite3_step(S)] but has neither run to completion (returned
+** [SQLITE_DONE] from [sqlite3_step(S)]) nor
+** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
+** interface returns false if S is a NULL pointer.  If S is not a 
+** NULL pointer and is not a pointer to a valid [prepared statement]
+** object, then the behavior is undefined and probably undesirable.
+**
+** This interface can be used in combination [sqlite3_next_stmt()]
+** to locate all prepared statements associated with a database 
+** connection that are in need of being reset.  This can be used,
+** for example, in diagnostic routines to search for prepared 
+** statements that are holding a transaction open.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Dynamically Typed Value Object
@@ -3485,7 +3874,9 @@ SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
 ** Some interfaces require a protected sqlite3_value.  Other interfaces
 ** will accept either a protected or an unprotected sqlite3_value.
 ** Every interface that accepts sqlite3_value arguments specifies
-** whether or not it requires a protected sqlite3_value.
+** whether or not it requires a protected sqlite3_value.  The
+** [sqlite3_value_dup()] interface can be used to construct a new 
+** protected sqlite3_value from an unprotected sqlite3_value.
 **
 ** The terms "protected" and "unprotected" refer to whether or not
 ** a mutex is held.  An internal mutex is held for a protected
@@ -3529,6 +3920,7 @@ typedef struct sqlite3_context sqlite3_context;
 ** CAPI3REF: Binding Values To Prepared Statements
 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
+** METHOD: sqlite3_stmt
 **
 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
 ** literals may be replaced by a [parameter] that matches one of following
@@ -3562,25 +3954,31 @@ typedef struct sqlite3_context sqlite3_context;
 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
 **
 ** ^The third argument is the value to bind to the parameter.
+** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
+** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
+** is ignored and the end result is the same as sqlite3_bind_null().
 **
 ** ^(In those routines that have a fourth argument, its value is the
 ** number of bytes in the parameter.  To be clear: the value is the
 ** number of <u>bytes</u> in the value, not the number of characters.)^
-** ^If the fourth parameter is negative, the length of the string is
+** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
+** is negative, then the length of the string is
 ** the number of bytes up to the first zero terminator.
+** If the fourth parameter to sqlite3_bind_blob() is negative, then
+** the behavior is undefined.
 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
-** or sqlite3_bind_text16() then that parameter must be the byte offset
+** or sqlite3_bind_text16() or sqlite3_bind_text64() then
+** that parameter must be the byte offset
 ** where the NUL terminator would occur assuming the string were NUL
 ** terminated.  If any NUL characters occur at byte offsets less than 
 ** the value of the fourth parameter then the resulting string value will
 ** contain embedded NULs.  The result of expressions involving strings
 ** with embedded NULs is undefined.
 **
-** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
-** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
+** ^The fifth argument to the BLOB and string binding interfaces
+** is a destructor used to dispose of the BLOB or
 ** string after SQLite has finished with it.  ^The destructor is called
-** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
-** sqlite3_bind_text(), or sqlite3_bind_text16() fails.  
+** to dispose of the BLOB or string even if the call to bind API fails.
 ** ^If the fifth argument is
 ** the special value [SQLITE_STATIC], then SQLite assumes that the
 ** information is in static, unmanaged space and does not need to be freed.
@@ -3588,6 +3986,14 @@ typedef struct sqlite3_context sqlite3_context;
 ** SQLite makes its own private copy of the data immediately, before
 ** the sqlite3_bind_*() routine returns.
 **
+** ^The sixth argument to sqlite3_bind_text64() must be one of
+** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
+** to specify the encoding of the text in the third parameter.  If
+** the sixth argument to sqlite3_bind_text64() is not one of the
+** allowed values shown above, or if the text encoding is different
+** from the encoding specified by the sixth parameter, then the behavior
+** is undefined.
+**
 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
 ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
 ** (just an integer to hold its size) while it is being processed.
@@ -3608,24 +4014,33 @@ typedef struct sqlite3_context sqlite3_context;
 **
 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
 ** [error code] if anything goes wrong.
+** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
+** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
+** [SQLITE_MAX_LENGTH].
 ** ^[SQLITE_RANGE] is returned if the parameter
 ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
 **
 ** See also: [sqlite3_bind_parameter_count()],
 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
 */
-SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
-SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
-SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
-SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
-SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
-SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
-SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
-SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
-SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
+                        void(*)(void*));
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
+                         void(*)(void*), unsigned char encoding);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
 
 /*
 ** CAPI3REF: Number Of SQL Parameters
+** METHOD: sqlite3_stmt
 **
 ** ^This routine can be used to find the number of [SQL parameters]
 ** in a [prepared statement].  SQL parameters are tokens of the
@@ -3642,10 +4057,11 @@ SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
 ** [sqlite3_bind_parameter_name()], and
 ** [sqlite3_bind_parameter_index()].
 */
-SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Name Of A Host Parameter
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
@@ -3669,10 +4085,11 @@ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
 ** [sqlite3_bind_parameter_count()], and
 ** [sqlite3_bind_parameter_index()].
 */
-SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int);
 
 /*
 ** CAPI3REF: Index Of A Parameter With A Given Name
+** METHOD: sqlite3_stmt
 **
 ** ^Return the index of an SQL parameter given its name.  ^The
 ** index value returned is suitable for use as the second
@@ -3683,21 +4100,23 @@ SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
 **
 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
 ** [sqlite3_bind_parameter_count()], and
-** [sqlite3_bind_parameter_index()].
+** [sqlite3_bind_parameter_name()].
 */
-SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
 
 /*
 ** CAPI3REF: Reset All Bindings On A Prepared Statement
+** METHOD: sqlite3_stmt
 **
 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
 ** ^Use this routine to reset all host parameters to NULL.
 */
-SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
+SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Number Of Columns In A Result Set
+** METHOD: sqlite3_stmt
 **
 ** ^Return the number of columns in the result set returned by the
 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
@@ -3705,10 +4124,11 @@ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
 **
 ** See also: [sqlite3_data_count()]
 */
-SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
+SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Column Names In A Result Set
+** METHOD: sqlite3_stmt
 **
 ** ^These routines return the name assigned to a particular column
 ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
@@ -3733,11 +4153,12 @@ SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
 ** then the name of the column is unspecified and may change from
 ** one release of SQLite to the next.
 */
-SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
-SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N);
 
 /*
 ** CAPI3REF: Source Of Data In A Query Result
+** METHOD: sqlite3_stmt
 **
 ** ^These routines provide a means to determine the database, table, and
 ** table column that is the origin of a particular result column in
@@ -3781,15 +4202,16 @@ SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
 ** for the same [prepared statement] and result column
 ** at the same time then the results are undefined.
 */
-SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
-SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
-SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
-SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
-SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
-SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int);
 
 /*
 ** CAPI3REF: Declared Datatype Of A Query Result
+** METHOD: sqlite3_stmt
 **
 ** ^(The first parameter is a [prepared statement].
 ** If this statement is a [SELECT] statement and the Nth column of the
@@ -3817,11 +4239,12 @@ SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
 ** is associated with individual values, not with the containers
 ** used to hold those values.
 */
-SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
-SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int);
 
 /*
 ** CAPI3REF: Evaluate An SQL Statement
+** METHOD: sqlite3_stmt
 **
 ** After a [prepared statement] has been prepared using either
 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
@@ -3897,10 +4320,11 @@ SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
 ** then the more specific [error codes] are returned directly
 ** by sqlite3_step().  The use of the "v2" interface is recommended.
 */
-SQLITE_API int sqlite3_step(sqlite3_stmt*);
+SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*);
 
 /*
 ** CAPI3REF: Number of columns in a result set
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
 ** current row of the result set of [prepared statement] P.
@@ -3917,7 +4341,7 @@ SQLITE_API int sqlite3_step(sqlite3_stmt*);
 **
 ** See also: [sqlite3_column_count()]
 */
-SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
+SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Fundamental Datatypes
@@ -3954,8 +4378,7 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 /*
 ** CAPI3REF: Result Values From A Query
 ** KEYWORDS: {column access functions}
-**
-** These routines form the "result set" interface.
+** METHOD: sqlite3_stmt
 **
 ** ^These routines return information about a single column of the current
 ** result row of a query.  ^In every case the first argument is a pointer
@@ -4013,16 +4436,17 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** bytes in the string, not the number of characters.
 **
 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
-** even empty strings, are always zero terminated.  ^The return
+** even empty strings, are always zero-terminated.  ^The return
 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
 **
-** ^The object returned by [sqlite3_column_value()] is an
-** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
-** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
+** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
+** [unprotected sqlite3_value] object.  In a multithreaded environment,
+** an unprotected sqlite3_value object may only be used safely with
+** [sqlite3_bind_value()] and [sqlite3_result_value()].
 ** If the [unprotected sqlite3_value] object returned by
 ** [sqlite3_column_value()] is used in any other way, including calls
 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
-** or [sqlite3_value_bytes()], then the behavior is undefined.
+** or [sqlite3_value_bytes()], the behavior is not threadsafe.
 **
 ** These routines attempt to convert the value where appropriate.  ^For
 ** example, if the internal representation is FLOAT and a text result
@@ -4036,29 +4460,23 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 **
 ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
 ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
-** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
-** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
+** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
+** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
 ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
 ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
 ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
-** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
+** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
 ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
-** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
-** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
-** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
+** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
+** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
+** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
 ** <tr><td>  TEXT    <td>   BLOB    <td> No change
-** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
-** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
+** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
+** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
 ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
 ** </table>
 ** </blockquote>)^
 **
-** The table above makes reference to standard C library functions atoi()
-** and atof().  SQLite does not really use these functions.  It has its
-** own equivalent internal routines.  The atoi() and atof() names are
-** used in the table for brevity and because they are familiar to most
-** C programmers.
-**
 ** Note that when type conversions occur, pointers returned by prior
 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
 ** sqlite3_column_text16() may be invalidated.
@@ -4083,7 +4501,7 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** of conversion are done in place when it is possible, but sometimes they
 ** are not possible and in those cases prior pointers are invalidated.
 **
-** The safest and easiest to remember policy is to invoke these routines
+** The safest policy is to invoke these routines
 ** in one of the following ways:
 **
 ** <ul>
@@ -4103,8 +4521,8 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** ^The pointers returned are valid until a type conversion occurs as
 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
 ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
-** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
-** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
+** and BLOBs is freed automatically.  Do <em>not</em> pass the pointers returned
+** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
 ** [sqlite3_free()].
 **
 ** ^(If a memory allocation error occurs during the evaluation of any
@@ -4113,19 +4531,20 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
 ** [SQLITE_NOMEM].)^
 */
-SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
-SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
-SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
-SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
-SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
-SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
-SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
-SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
-SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
-SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol);
+SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol);
+SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
+SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol);
+SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol);
+SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol);
+SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol);
+SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol);
 
 /*
 ** CAPI3REF: Destroy A Prepared Statement Object
+** DESTRUCTOR: sqlite3_stmt
 **
 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
 ** ^If the most recent evaluation of the statement encountered no errors
@@ -4149,10 +4568,11 @@ SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
 ** statement after it has been finalized can result in undefined and
 ** undesirable behavior such as segfaults and heap corruption.
 */
-SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
+SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Reset A Prepared Statement Object
+** METHOD: sqlite3_stmt
 **
 ** The sqlite3_reset() function is called to reset a [prepared statement]
 ** object back to its initial state, ready to be re-executed.
@@ -4175,13 +4595,14 @@ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
 ** ^The [sqlite3_reset(S)] interface does not change the values
 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
 */
-SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
+SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Create Or Redefine SQL Functions
 ** KEYWORDS: {function creation routines}
 ** KEYWORDS: {application-defined SQL function}
 ** KEYWORDS: {application-defined SQL functions}
+** METHOD: sqlite3
 **
 ** ^These functions (collectively known as "function creation routines")
 ** are used to add SQL functions or aggregates or to redefine the behavior
@@ -4213,15 +4634,24 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
 **
 ** ^The fourth parameter, eTextRep, specifies what
 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
-** its parameters.  Every SQL function implementation must be able to work
-** with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
-** more efficient with one encoding than another.  ^An application may
-** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
-** times with the same function but with different values of eTextRep.
+** its parameters.  The application should set this parameter to
+** [SQLITE_UTF16LE] if the function implementation invokes 
+** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
+** implementation invokes [sqlite3_value_text16be()] on an input, or
+** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
+** otherwise.  ^The same SQL function may be registered multiple times using
+** different preferred text encodings, with different implementations for
+** each encoding.
 ** ^When multiple implementations of the same function are available, SQLite
 ** will pick the one that involves the least amount of data conversion.
-** If there is only a single implementation which does not care what text
-** encoding is used, then the fourth argument should be [SQLITE_ANY].
+**
+** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
+** to signal that the function will always return the same result given
+** the same inputs within a single SQL statement.  Most SQL functions are
+** deterministic.  The built-in [random()] SQL function is an example of a
+** function that is not deterministic.  The SQLite query planner is able to
+** perform additional optimizations on deterministic functions, so use
+** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
 **
 ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
 ** function can gain access to this pointer using [sqlite3_user_data()].)^
@@ -4265,7 +4695,7 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
 ** close the database connection nor finalize or reset the prepared
 ** statement in which the function is running.
 */
-SQLITE_API int sqlite3_create_function(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
   sqlite3 *db,
   const char *zFunctionName,
   int nArg,
@@ -4275,7 +4705,7 @@ SQLITE_API int sqlite3_create_function(
   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
   void (*xFinal)(sqlite3_context*)
 );
-SQLITE_API int sqlite3_create_function16(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
   sqlite3 *db,
   const void *zFunctionName,
   int nArg,
@@ -4285,7 +4715,7 @@ SQLITE_API int sqlite3_create_function16(
   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
   void (*xFinal)(sqlite3_context*)
 );
-SQLITE_API int sqlite3_create_function_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
   sqlite3 *db,
   const char *zFunctionName,
   int nArg,
@@ -4303,38 +4733,50 @@ SQLITE_API int sqlite3_create_function_v2(
 ** These constant define integer codes that represent the various
 ** text encodings supported by SQLite.
 */
-#define SQLITE_UTF8           1
-#define SQLITE_UTF16LE        2
-#define SQLITE_UTF16BE        3
+#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
+#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
+#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
 #define SQLITE_UTF16          4    /* Use native byte order */
-#define SQLITE_ANY            5    /* sqlite3_create_function only */
+#define SQLITE_ANY            5    /* Deprecated */
 #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
 
 /*
+** CAPI3REF: Function Flags
+**
+** These constants may be ORed together with the 
+** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
+** to [sqlite3_create_function()], [sqlite3_create_function16()], or
+** [sqlite3_create_function_v2()].
+*/
+#define SQLITE_DETERMINISTIC    0x800
+
+/*
 ** CAPI3REF: Deprecated Functions
 ** DEPRECATED
 **
 ** These functions are [deprecated].  In order to maintain
 ** backwards compatibility with older code, these functions continue 
 ** to be supported.  However, new applications should avoid
-** the use of these functions.  To help encourage people to avoid
-** using these functions, we are not going to tell you what they do.
+** the use of these functions.  To encourage programmers to avoid
+** these functions, we will not explain what they do.
 */
 #ifndef SQLITE_OMIT_DEPRECATED
-SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
-SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
-SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
-SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
-SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
-SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
+SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*);
+SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*);
+SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
+SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void);
+SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void);
+SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
+                      void*,sqlite3_int64);
 #endif
 
 /*
-** CAPI3REF: Obtaining SQL Function Parameter Values
+** CAPI3REF: Obtaining SQL Values
+** METHOD: sqlite3_value
 **
 ** The C-language implementation of SQL functions and aggregates uses
 ** this set of interface routines to access the parameter values on
-** the function or aggregate.
+** the function or aggregate.  
 **
 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
@@ -4349,7 +4791,7 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6
 ** object results in undefined behavior.
 **
 ** ^These routines work just like the corresponding [column access functions]
-** except that  these routines take a single [protected sqlite3_value] object
+** except that these routines take a single [protected sqlite3_value] object
 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
 **
 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
@@ -4374,21 +4816,55 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6
 ** These routines must be called from the same thread as
 ** the SQL function that supplied the [sqlite3_value*] parameters.
 */
-SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
-SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
-SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
-SQLITE_API double sqlite3_value_double(sqlite3_value*);
-SQLITE_API int sqlite3_value_int(sqlite3_value*);
-SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
-SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
-SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
-SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
-SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
-SQLITE_API int sqlite3_value_type(sqlite3_value*);
-SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*);
+SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*);
+SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*);
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*);
+
+/*
+** CAPI3REF: Finding The Subtype Of SQL Values
+** METHOD: sqlite3_value
+**
+** The sqlite3_value_subtype(V) function returns the subtype for
+** an [application-defined SQL function] argument V.  The subtype
+** information can be used to pass a limited amount of context from
+** one SQL function to another.  Use the [sqlite3_result_subtype()]
+** routine to set the subtype for the return value of an SQL function.
+**
+** SQLite makes no use of subtype itself.  It merely passes the subtype
+** from the result of one [application-defined SQL function] into the
+** input of another.
+*/
+SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*);
+
+/*
+** CAPI3REF: Copy And Free SQL Values
+** METHOD: sqlite3_value
+**
+** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
+** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
+** is a [protected sqlite3_value] object even if the input is not.
+** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
+** memory allocation fails.
+**
+** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
+** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
+** then sqlite3_value_free(V) is a harmless no-op.
+*/
+SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*);
+SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*);
 
 /*
 ** CAPI3REF: Obtain Aggregate Function Context
+** METHOD: sqlite3_context
 **
 ** Implementations of aggregate SQL functions use this
 ** routine to allocate memory for storing their state.
@@ -4406,14 +4882,17 @@ SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
 ** In those cases, sqlite3_aggregate_context() might be called for the
 ** first time from within xFinal().)^
 **
-** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
-** less than or equal to zero or if a memory allocate error occurs.
+** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 
+** when first called if N is less than or equal to zero or if a memory
+** allocate error occurs.
 **
 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
 ** determined by the N parameter on first successful call.  Changing the
 ** value of N in subsequent call to sqlite3_aggregate_context() within
 ** the same aggregate function instance will not resize the memory
-** allocation.)^
+** allocation.)^  Within the xFinal callback, it is customary to set
+** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 
+** pointless memory allocations occur.
 **
 ** ^SQLite automatically frees the memory allocated by 
 ** sqlite3_aggregate_context() when the aggregate query concludes.
@@ -4426,10 +4905,11 @@ SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
 ** This routine must be called from the same thread in which
 ** the aggregate SQL function is running.
 */
-SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
+SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes);
 
 /*
 ** CAPI3REF: User Data For Functions
+** METHOD: sqlite3_context
 **
 ** ^The sqlite3_user_data() interface returns a copy of
 ** the pointer that was the pUserData parameter (the 5th parameter)
@@ -4440,10 +4920,11 @@ SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
 ** This routine must be called from the same thread in which
 ** the application-defined function is running.
 */
-SQLITE_API void *sqlite3_user_data(sqlite3_context*);
+SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*);
 
 /*
 ** CAPI3REF: Database Connection For Functions
+** METHOD: sqlite3_context
 **
 ** ^The sqlite3_context_db_handle() interface returns a copy of
 ** the pointer to the [database connection] (the 1st parameter)
@@ -4451,52 +4932,62 @@ SQLITE_API void *sqlite3_user_data(sqlite3_context*);
 ** and [sqlite3_create_function16()] routines that originally
 ** registered the application defined function.
 */
-SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*);
 
 /*
 ** CAPI3REF: Function Auxiliary Data
+** METHOD: sqlite3_context
 **
-** The following two functions may be used by scalar SQL functions to
+** These functions may be used by (non-aggregate) SQL functions to
 ** associate metadata with argument values. If the same value is passed to
 ** multiple invocations of the same SQL function during query execution, under
-** some circumstances the associated metadata may be preserved. This may
-** be used, for example, to add a regular-expression matching scalar
-** function. The compiled version of the regular expression is stored as
-** metadata associated with the SQL value passed as the regular expression
-** pattern.  The compiled regular expression can be reused on multiple
-** invocations of the same function so that the original pattern string
-** does not need to be recompiled on each invocation.
+** some circumstances the associated metadata may be preserved.  An example
+** of where this might be useful is in a regular-expression matching
+** function. The compiled version of the regular expression can be stored as
+** metadata associated with the pattern string.  
+** Then as long as the pattern string remains the same,
+** the compiled regular expression can be reused on multiple
+** invocations of the same function.
 **
 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
 ** associated by the sqlite3_set_auxdata() function with the Nth argument
-** value to the application-defined function. ^If no metadata has been ever
-** been set for the Nth argument of the function, or if the corresponding
-** function parameter has changed since the meta-data was set,
-** then sqlite3_get_auxdata() returns a NULL pointer.
-**
-** ^The sqlite3_set_auxdata() interface saves the metadata
-** pointed to by its 3rd parameter as the metadata for the N-th
-** argument of the application-defined function.  Subsequent
-** calls to sqlite3_get_auxdata() might return this data, if it has
-** not been destroyed.
-** ^If it is not NULL, SQLite will invoke the destructor
-** function given by the 4th parameter to sqlite3_set_auxdata() on
-** the metadata when the corresponding function parameter changes
-** or when the SQL statement completes, whichever comes first.
-**
-** SQLite is free to call the destructor and drop metadata on any
-** parameter of any function at any time.  ^The only guarantee is that
-** the destructor will be called before the metadata is dropped.
+** value to the application-defined function. ^If there is no metadata
+** associated with the function argument, this sqlite3_get_auxdata() interface
+** returns a NULL pointer.
+**
+** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
+** argument of the application-defined function.  ^Subsequent
+** calls to sqlite3_get_auxdata(C,N) return P from the most recent
+** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
+** NULL if the metadata has been discarded.
+** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
+** SQLite will invoke the destructor function X with parameter P exactly
+** once, when the metadata is discarded.
+** SQLite is free to discard the metadata at any time, including: <ul>
+** <li> ^(when the corresponding function parameter changes)^, or
+** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
+**      SQL statement)^, or
+** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
+**       parameter)^, or
+** <li> ^(during the original sqlite3_set_auxdata() call when a memory 
+**      allocation error occurs.)^ </ul>
+**
+** Note the last bullet in particular.  The destructor X in 
+** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
+** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
+** should be called near the end of the function implementation and the
+** function implementation should not make any use of P after
+** sqlite3_set_auxdata() has been called.
 **
 ** ^(In practice, metadata is preserved between function calls for
-** expressions that are constant at compile time. This includes literal
-** values and [parameters].)^
+** function parameters that are compile-time constants, including literal
+** values and [parameters] and expressions composed from the same.)^
 **
 ** These routines must be called from the same thread in which
 ** the SQL function is running.
 */
-SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
-SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
+SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N);
+SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
 
 
 /*
@@ -4511,7 +5002,7 @@ SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(voi
 ** the content before returning.
 **
 ** The typedef is necessary to work around problems in certain
-** C++ compilers.  See ticket #2191.
+** C++ compilers.
 */
 typedef void (*sqlite3_destructor_type)(void*);
 #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
@@ -4519,6 +5010,7 @@ typedef void (*sqlite3_destructor_type)(void*);
 
 /*
 ** CAPI3REF: Setting The Result Of An SQL Function
+** METHOD: sqlite3_context
 **
 ** These routines are used by the xFunc or xFinal callbacks that
 ** implement SQL functions and aggregates.  See
@@ -4534,9 +5026,9 @@ typedef void (*sqlite3_destructor_type)(void*);
 ** to by the second parameter and which is N bytes long where N is the
 ** third parameter.
 **
-** ^The sqlite3_result_zeroblob() interfaces set the result of
-** the application-defined function to be a BLOB containing all zero
-** bytes and N bytes in size, where N is the value of the 2nd parameter.
+** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
+** interfaces set the result of the application-defined function to be
+** a BLOB containing all zero bytes and N bytes in size.
 **
 ** ^The sqlite3_result_double() interface sets the result from
 ** an application-defined function to be a floating point value specified
@@ -4564,11 +5056,11 @@ typedef void (*sqlite3_destructor_type)(void*);
 ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
 **
-** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
-** indicating that a string or BLOB is too long to represent.
+** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
+** error indicating that a string or BLOB is too long to represent.
 **
-** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
-** indicating that a memory allocation failed.
+** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
+** error indicating that a memory allocation failed.
 **
 ** ^The sqlite3_result_int() interface sets the return value
 ** of the application-defined function to be the 32-bit signed integer
@@ -4585,6 +5077,10 @@ typedef void (*sqlite3_destructor_type)(void*);
 ** set the return value of the application-defined function to be
 ** a text string which is represented as UTF-8, UTF-16 native byte order,
 ** UTF-16 little endian, or UTF-16 big endian, respectively.
+** ^The sqlite3_result_text64() interface sets the return value of an
+** application-defined function to be a text string in an encoding
+** specified by the fifth (and last) parameter, which must be one
+** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
 ** ^SQLite takes the text result from the application from
 ** the 2nd parameter of the sqlite3_result_text* interfaces.
 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
@@ -4614,7 +5110,7 @@ typedef void (*sqlite3_destructor_type)(void*);
 ** from [sqlite3_malloc()] before it returns.
 **
 ** ^The sqlite3_result_value() interface sets the result of
-** the application-defined function to be a copy the
+** the application-defined function to be a copy of the
 ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
 ** so that the [sqlite3_value] specified in the parameter may change or
@@ -4627,25 +5123,46 @@ typedef void (*sqlite3_destructor_type)(void*);
 ** than the one containing the application-defined function that received
 ** the [sqlite3_context] pointer, the results are undefined.
 */
-SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
-SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
-SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
-SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
-SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
-SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
-SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
-SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
-SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
-SQLITE_API void sqlite3_result_null(sqlite3_context*);
-SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
-SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
-SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
-SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
-SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
-SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*,
+                           sqlite3_uint64,void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
+                           void(*)(void*), unsigned char encoding);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
+SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n);
+SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
+
+
+/*
+** CAPI3REF: Setting The Subtype Of An SQL Function
+** METHOD: sqlite3_context
+**
+** The sqlite3_result_subtype(C,T) function causes the subtype of
+** the result from the [application-defined SQL function] with 
+** [sqlite3_context] C to be the value T.  Only the lower 8 bits 
+** of the subtype T are preserved in current versions of SQLite;
+** higher order bits are discarded.
+** The number of subtype bytes preserved by SQLite might increase
+** in future releases of SQLite.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int);
 
 /*
 ** CAPI3REF: Define New Collating Sequences
+** METHOD: sqlite3
 **
 ** ^These functions add, remove, or modify a [collation] associated
 ** with the [database connection] specified as the first argument.
@@ -4723,14 +5240,14 @@ SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
 **
 ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
 */
-SQLITE_API int sqlite3_create_collation(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
   sqlite3*, 
   const char *zName, 
   int eTextRep, 
   void *pArg,
   int(*xCompare)(void*,int,const void*,int,const void*)
 );
-SQLITE_API int sqlite3_create_collation_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
   sqlite3*, 
   const char *zName, 
   int eTextRep, 
@@ -4738,7 +5255,7 @@ SQLITE_API int sqlite3_create_collation_v2(
   int(*xCompare)(void*,int,const void*,int,const void*),
   void(*xDestroy)(void*)
 );
-SQLITE_API int sqlite3_create_collation16(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
   sqlite3*, 
   const void *zName,
   int eTextRep, 
@@ -4748,6 +5265,7 @@ SQLITE_API int sqlite3_create_collation16(
 
 /*
 ** CAPI3REF: Collation Needed Callbacks
+** METHOD: sqlite3
 **
 ** ^To avoid having to register all collation sequences before a database
 ** can be used, a single callback function may be registered with the
@@ -4772,12 +5290,12 @@ SQLITE_API int sqlite3_create_collation16(
 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
 ** [sqlite3_create_collation_v2()].
 */
-SQLITE_API int sqlite3_collation_needed(
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
   sqlite3*, 
   void*, 
   void(*)(void*,sqlite3*,int eTextRep,const char*)
 );
-SQLITE_API int sqlite3_collation_needed16(
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
   sqlite3*, 
   void*,
   void(*)(void*,sqlite3*,int eTextRep,const void*)
@@ -4791,8 +5309,13 @@ SQLITE_API int sqlite3_collation_needed16(
 ** The code to implement this API is not available in the public release
 ** of SQLite.
 */
-SQLITE_API int sqlite3_key(
+SQLITE_API int SQLITE_STDCALL sqlite3_key(
+  sqlite3 *db,                   /* Database to be rekeyed */
+  const void *pKey, int nKey     /* The key */
+);
+SQLITE_API int SQLITE_STDCALL sqlite3_key_v2(
   sqlite3 *db,                   /* Database to be rekeyed */
+  const char *zDbName,           /* Name of the database */
   const void *pKey, int nKey     /* The key */
 );
 
@@ -4804,16 +5327,21 @@ SQLITE_API int sqlite3_key(
 ** The code to implement this API is not available in the public release
 ** of SQLite.
 */
-SQLITE_API int sqlite3_rekey(
+SQLITE_API int SQLITE_STDCALL sqlite3_rekey(
   sqlite3 *db,                   /* Database to be rekeyed */
   const void *pKey, int nKey     /* The new key */
 );
+SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2(
+  sqlite3 *db,                   /* Database to be rekeyed */
+  const char *zDbName,           /* Name of the database */
+  const void *pKey, int nKey     /* The new key */
+);
 
 /*
 ** Specify the activation key for a SEE database.  Unless 
 ** activated, none of the SEE routines will work.
 */
-SQLITE_API void sqlite3_activate_see(
+SQLITE_API void SQLITE_STDCALL sqlite3_activate_see(
   const char *zPassPhrase        /* Activation phrase */
 );
 #endif
@@ -4823,7 +5351,7 @@ SQLITE_API void sqlite3_activate_see(
 ** Specify the activation key for a CEROD database.  Unless 
 ** activated, none of the CEROD routines will work.
 */
-SQLITE_API void sqlite3_activate_cerod(
+SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod(
   const char *zPassPhrase        /* Activation phrase */
 );
 #endif
@@ -4845,7 +5373,7 @@ SQLITE_API void sqlite3_activate_cerod(
 ** all, then the behavior of sqlite3_sleep() may deviate from the description
 ** in the previous paragraphs.
 */
-SQLITE_API int sqlite3_sleep(int);
+SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int);
 
 /*
 ** CAPI3REF: Name Of The Folder Holding Temporary Files
@@ -4857,6 +5385,13 @@ SQLITE_API int sqlite3_sleep(int);
 ** is a NULL pointer, then SQLite performs a search for an appropriate
 ** temporary file directory.
 **
+** Applications are strongly discouraged from using this global variable.
+** It is required to set a temporary folder on Windows Runtime (WinRT).
+** But for all other platforms, it is highly recommended that applications
+** neither read nor write this variable.  This global variable is a relic
+** that exists for backwards compatibility of legacy applications and should
+** be avoided in new projects.
+**
 ** It is not safe to read or modify this variable in more than one
 ** thread at a time.  It is not safe to read or modify this variable
 ** if a [database connection] is being used at the same time in a separate
@@ -4875,12 +5410,70 @@ SQLITE_API int sqlite3_sleep(int);
 ** Hence, if this variable is modified directly, either it should be
 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
 ** or else the use of the [temp_store_directory pragma] should be avoided.
+** Except when requested by the [temp_store_directory pragma], SQLite
+** does not free the memory that sqlite3_temp_directory points to.  If
+** the application wants that memory to be freed, it must do
+** so itself, taking care to only do so after all [database connection]
+** objects have been destroyed.
+**
+** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
+** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
+** features that require the use of temporary files may fail.  Here is an
+** example of how to do this using C++ with the Windows Runtime:
+**
+** <blockquote><pre>
+** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
+** &nbsp;     TemporaryFolder->Path->Data();
+** char zPathBuf&#91;MAX_PATH + 1&#93;;
+** memset(zPathBuf, 0, sizeof(zPathBuf));
+** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
+** &nbsp;     NULL, NULL);
+** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
+** </pre></blockquote>
 */
 SQLITE_API char *sqlite3_temp_directory;
 
 /*
+** CAPI3REF: Name Of The Folder Holding Database Files
+**
+** ^(If this global variable is made to point to a string which is
+** the name of a folder (a.k.a. directory), then all database files
+** specified with a relative pathname and created or accessed by
+** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
+** to be relative to that directory.)^ ^If this variable is a NULL
+** pointer, then SQLite assumes that all database files specified
+** with a relative pathname are relative to the current directory
+** for the process.  Only the windows VFS makes use of this global
+** variable; it is ignored by the unix VFS.
+**
+** Changing the value of this variable while a database connection is
+** open can result in a corrupt database.
+**
+** It is not safe to read or modify this variable in more than one
+** thread at a time.  It is not safe to read or modify this variable
+** if a [database connection] is being used at the same time in a separate
+** thread.
+** It is intended that this variable be set once
+** as part of process initialization and before any SQLite interface
+** routines have been called and that this variable remain unchanged
+** thereafter.
+**
+** ^The [data_store_directory pragma] may modify this variable and cause
+** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
+** the [data_store_directory pragma] always assumes that any string
+** that this variable points to is held in memory obtained from 
+** [sqlite3_malloc] and the pragma may attempt to free that memory
+** using [sqlite3_free].
+** Hence, if this variable is modified directly, either it should be
+** made NULL or made to point to memory obtained from [sqlite3_malloc]
+** or else the use of the [data_store_directory pragma] should be avoided.
+*/
+SQLITE_API char *sqlite3_data_directory;
+
+/*
 ** CAPI3REF: Test For Auto-Commit Mode
 ** KEYWORDS: {autocommit mode}
+** METHOD: sqlite3
 **
 ** ^The sqlite3_get_autocommit() interface returns non-zero or
 ** zero if the given database connection is or is not in autocommit mode,
@@ -4899,10 +5492,11 @@ SQLITE_API char *sqlite3_temp_directory;
 ** connection while this routine is running, then the return value
 ** is undefined.
 */
-SQLITE_API int sqlite3_get_autocommit(sqlite3*);
+SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*);
 
 /*
 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
+** METHOD: sqlite3_stmt
 **
 ** ^The sqlite3_db_handle interface returns the [database connection] handle
 ** to which a [prepared statement] belongs.  ^The [database connection]
@@ -4911,10 +5505,38 @@ SQLITE_API int sqlite3_get_autocommit(sqlite3*);
 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
 ** create the statement in the first place.
 */
-SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*);
+
+/*
+** CAPI3REF: Return The Filename For A Database Connection
+** METHOD: sqlite3
+**
+** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
+** associated with database N of connection D.  ^The main database file
+** has the name "main".  If there is no attached database N on the database
+** connection D, or if database N is a temporary or in-memory database, then
+** a NULL pointer is returned.
+**
+** ^The filename returned by this function is the output of the
+** xFullPathname method of the [VFS].  ^In other words, the filename
+** will be an absolute pathname, even if the filename used
+** to open the database originally was a URI or relative pathname.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName);
+
+/*
+** CAPI3REF: Determine if a database is read-only
+** METHOD: sqlite3
+**
+** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
+** of connection D is read-only, 0 if it is read/write, or -1 if N is not
+** the name of a database on connection D.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
 
 /*
 ** CAPI3REF: Find the next prepared statement
+** METHOD: sqlite3
 **
 ** ^This interface returns a pointer to the next [prepared statement] after
 ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
@@ -4926,10 +5548,11 @@ SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
 ** [sqlite3_next_stmt(D,S)] must refer to an open database
 ** connection and in particular must not be a NULL pointer.
 */
-SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
+SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
 
 /*
 ** CAPI3REF: Commit And Rollback Notification Callbacks
+** METHOD: sqlite3
 **
 ** ^The sqlite3_commit_hook() interface registers a callback
 ** function to be invoked whenever a transaction is [COMMIT | committed].
@@ -4948,13 +5571,15 @@ SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
 ** on the same [database connection] D, or NULL for
 ** the first call for each function on D.
 **
+** The commit and rollback hook callbacks are not reentrant.
 ** The callback implementation must not do anything that will modify
 ** the database connection that invoked the callback.  Any actions
 ** to modify the database connection must be deferred until after the
 ** completion of the [sqlite3_step()] call that triggered the commit
 ** or rollback hook in the first place.
-** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
-** database connections for the meaning of "modify" in this paragraph.
+** Note that running any other SQL statements, including SELECT statements,
+** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
+** the database connections for the meaning of "modify" in this paragraph.
 **
 ** ^Registering a NULL function disables the callback.
 **
@@ -4972,20 +5597,22 @@ SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
 **
 ** See also the [sqlite3_update_hook()] interface.
 */
-SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
-SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
+SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
+SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
 
 /*
 ** CAPI3REF: Data Change Notification Callbacks
+** METHOD: sqlite3
 **
 ** ^The sqlite3_update_hook() interface registers a callback function
 ** with the [database connection] identified by the first argument
-** to be invoked whenever a row is updated, inserted or deleted.
+** to be invoked whenever a row is updated, inserted or deleted in
+** a [rowid table].
 ** ^Any callback set by a previous call to this function
 ** for the same database connection is overridden.
 **
 ** ^The second argument is a pointer to the function to invoke when a
-** row is updated, inserted or deleted.
+** row is updated, inserted or deleted in a rowid table.
 ** ^The first argument to the callback is a copy of the third argument
 ** to sqlite3_update_hook().
 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
@@ -4998,6 +5625,7 @@ SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
 **
 ** ^(The update hook is not invoked when internal system tables are
 ** modified (i.e. sqlite_master and sqlite_sequence).)^
+** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
 **
 ** ^In the current implementation, the update hook
 ** is not invoked when duplication rows are deleted because of an
@@ -5018,10 +5646,10 @@ SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
 ** on the same [database connection] D, or NULL for
 ** the first call on D.
 **
-** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
-** interfaces.
+** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
+** and [sqlite3_preupdate_hook()] interfaces.
 */
-SQLITE_API void *sqlite3_update_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
   sqlite3*, 
   void(*)(void *,int ,char const *,char const *,sqlite3_int64),
   void*
@@ -5029,7 +5657,6 @@ SQLITE_API void *sqlite3_update_hook(
 
 /*
 ** CAPI3REF: Enable Or Disable Shared Pager Cache
-** KEYWORDS: {shared cache}
 **
 ** ^(This routine enables or disables the sharing of the database cache
 ** and schema data structures between [database connection | connections]
@@ -5052,9 +5679,17 @@ SQLITE_API void *sqlite3_update_hook(
 ** future releases of SQLite.  Applications that care about shared
 ** cache setting should set it explicitly.
 **
+** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
+** and will always return SQLITE_MISUSE. On those systems, 
+** shared cache mode should be enabled per-database connection via 
+** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
+**
+** This interface is threadsafe on processors where writing a
+** 32-bit integer is atomic.
+**
 ** See Also:  [SQLite Shared-Cache Mode]
 */
-SQLITE_API int sqlite3_enable_shared_cache(int);
+SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int);
 
 /*
 ** CAPI3REF: Attempt To Free Heap Memory
@@ -5067,8 +5702,24 @@ SQLITE_API int sqlite3_enable_shared_cache(int);
 ** which might be more or less than the amount requested.
 ** ^The sqlite3_release_memory() routine is a no-op returning zero
 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
+**
+** See also: [sqlite3_db_release_memory()]
 */
-SQLITE_API int sqlite3_release_memory(int);
+SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int);
+
+/*
+** CAPI3REF: Free Memory Used By A Database Connection
+** METHOD: sqlite3
+**
+** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
+** memory as possible from database connection D. Unlike the
+** [sqlite3_release_memory()] interface, this interface is in effect even
+** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
+** omitted.
+**
+** See also: [sqlite3_release_memory()]
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*);
 
 /*
 ** CAPI3REF: Impose A Limit On Heap Size
@@ -5084,7 +5735,8 @@ SQLITE_API int sqlite3_release_memory(int);
 ** is advisory only.
 **
 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
-** the soft heap limit prior to the call.  ^If the argument N is negative
+** the soft heap limit prior to the call, or negative in the case of an
+** error.  ^If the argument N is negative
 ** then no change is made to the soft heap limit.  Hence, the current
 ** size of the soft heap limit can be determined by invoking
 ** sqlite3_soft_heap_limit64() with a negative argument.
@@ -5100,7 +5752,7 @@ SQLITE_API int sqlite3_release_memory(int);
 **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
 **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
 ** <li> An alternative page cache implementation is specified using
-**      [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
+**      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
 ** <li> The page cache allocates from its own memory pool supplied
 **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
 **      from the heap.
@@ -5119,7 +5771,7 @@ SQLITE_API int sqlite3_release_memory(int);
 ** The circumstances under which SQLite will enforce the soft heap limit may
 ** changes in future releases of SQLite.
 */
-SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N);
 
 /*
 ** CAPI3REF: Deprecated Soft Heap Limit Interface
@@ -5130,26 +5782,34 @@ SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
 ** only.  All new applications should use the
 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
 */
-SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
+SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N);
 
 
 /*
 ** CAPI3REF: Extract Metadata About A Column Of A Table
-**
-** ^This routine returns metadata about a specific column of a specific
-** database table accessible using the [database connection] handle
-** passed as the first function argument.
+** METHOD: sqlite3
+**
+** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
+** information about column C of table T in database D
+** on [database connection] X.)^  ^The sqlite3_table_column_metadata()
+** interface returns SQLITE_OK and fills in the non-NULL pointers in
+** the final five arguments with appropriate values if the specified
+** column exists.  ^The sqlite3_table_column_metadata() interface returns
+** SQLITE_ERROR and if the specified column does not exist.
+** ^If the column-name parameter to sqlite3_table_column_metadata() is a
+** NULL pointer, then this routine simply checks for the existence of the
+** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
+** does not.
 **
 ** ^The column is identified by the second, third and fourth parameters to
-** this function. ^The second parameter is either the name of the database
+** this function. ^(The second parameter is either the name of the database
 ** (i.e. "main", "temp", or an attached database) containing the specified
-** table or NULL. ^If it is NULL, then all attached databases are searched
+** table or NULL.)^ ^If it is NULL, then all attached databases are searched
 ** for the table using the same algorithm used by the database engine to
 ** resolve unqualified table references.
 **
 ** ^The third and fourth parameters to this function are the table and column
-** name of the desired column, respectively. Neither of these parameters
-** may be NULL.
+** name of the desired column, respectively.
 **
 ** ^Metadata is returned by writing to the memory locations passed as the 5th
 ** and subsequent parameters to this function. ^Any of these arguments may be
@@ -5168,16 +5828,17 @@ SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
 ** </blockquote>)^
 **
 ** ^The memory pointed to by the character pointers returned for the
-** declaration type and collation sequence is valid only until the next
+** declaration type and collation sequence is valid until the next
 ** call to any SQLite API function.
 **
 ** ^If the specified table is actually a view, an [error code] is returned.
 **
-** ^If the specified column is "rowid", "oid" or "_rowid_" and an
+** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 
+** is not a [WITHOUT ROWID] table and an
 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
 ** parameters are set for the explicitly declared column. ^(If there is no
-** explicitly declared [INTEGER PRIMARY KEY] column, then the output
-** parameters are set as follows:
+** [INTEGER PRIMARY KEY] column, then the outputs
+** for the [rowid] are set as follows:
 **
 ** <pre>
 **     data type: "INTEGER"
@@ -5187,15 +5848,11 @@ SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
 **     auto increment: 0
 ** </pre>)^
 **
-** ^(This function may load one or more schemas from database files. If an
-** error occurs during this process, or if the requested table or column
-** cannot be found, an [error code] is returned and an error message left
-** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
-**
-** ^This API is only available if the library was compiled with the
-** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
+** ^This function causes all database schemas to be read from disk and
+** parsed, if that has not already been done, and returns an error if
+** any errors are encountered while loading the schema.
 */
-SQLITE_API int sqlite3_table_column_metadata(
+SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
   sqlite3 *db,                /* Connection handle */
   const char *zDbName,        /* Database name or NULL */
   const char *zTableName,     /* Table name */
@@ -5209,15 +5866,25 @@ SQLITE_API int sqlite3_table_column_metadata(
 
 /*
 ** CAPI3REF: Load An Extension
+** METHOD: sqlite3
 **
 ** ^This interface loads an SQLite extension library from the named file.
 **
 ** ^The sqlite3_load_extension() interface attempts to load an
-** SQLite extension library contained in the file zFile.
+** [SQLite extension] library contained in the file zFile.  If
+** the file cannot be loaded directly, attempts are made to load
+** with various operating-system specific extensions added.
+** So for example, if "samplelib" cannot be loaded, then names like
+** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
+** be tried also.
 **
 ** ^The entry point is zProc.
-** ^zProc may be 0, in which case the name of the entry point
-** defaults to "sqlite3_extension_init".
+** ^(zProc may be 0, in which case SQLite will try to come up with an
+** entry point name on its own.  It first tries "sqlite3_extension_init".
+** If that does not work, it constructs a name "sqlite3_X_init" where the
+** X is consists of the lower-case equivalent of all ASCII alphabetic
+** characters in the filename from the last "/" to the first following
+** "." and omitting any initial "lib".)^
 ** ^The sqlite3_load_extension() interface returns
 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
 ** ^If an error occurs and pzErrMsg is not 0, then the
@@ -5227,12 +5894,21 @@ SQLITE_API int sqlite3_table_column_metadata(
 ** should free this memory by calling [sqlite3_free()].
 **
 ** ^Extension loading must be enabled using
-** [sqlite3_enable_load_extension()] prior to calling this API,
+** [sqlite3_enable_load_extension()] or
+** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
+** prior to calling this API,
 ** otherwise an error will be returned.
 **
+** <b>Security warning:</b> It is recommended that the 
+** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
+** interface.  The use of the [sqlite3_enable_load_extension()] interface
+** should be avoided.  This will keep the SQL function [load_extension()]
+** disabled and prevent SQL injections from giving attackers
+** access to extension loading capabilities.
+**
 ** See also the [load_extension() SQL function].
 */
-SQLITE_API int sqlite3_load_extension(
+SQLITE_API int SQLITE_STDCALL sqlite3_load_extension(
   sqlite3 *db,          /* Load the extension into this database connection */
   const char *zFile,    /* Name of the shared library containing extension */
   const char *zProc,    /* Entry point.  Derived from zFile if 0 */
@@ -5241,30 +5917,42 @@ SQLITE_API int sqlite3_load_extension(
 
 /*
 ** CAPI3REF: Enable Or Disable Extension Loading
+** METHOD: sqlite3
 **
 ** ^So as not to open security holes in older applications that are
-** unprepared to deal with extension loading, and as a means of disabling
-** extension loading while evaluating user-entered SQL, the following API
+** unprepared to deal with [extension loading], and as a means of disabling
+** [extension loading] while evaluating user-entered SQL, the following API
 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
 **
-** ^Extension loading is off by default. See ticket #1863.
+** ^Extension loading is off by default.
 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
 ** to turn extension loading on and call it with onoff==0 to turn
 ** it back off again.
+**
+** ^This interface enables or disables both the C-API
+** [sqlite3_load_extension()] and the SQL function [load_extension()].
+** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
+** to enable or disable only the C-API.)^
+**
+** <b>Security warning:</b> It is recommended that extension loading
+** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
+** rather than this interface, so the [load_extension()] SQL function
+** remains disabled. This will prevent SQL injections from giving attackers
+** access to extension loading capabilities.
 */
-SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
+SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff);
 
 /*
 ** CAPI3REF: Automatically Load Statically Linked Extensions
 **
 ** ^This interface causes the xEntryPoint() function to be invoked for
 ** each new [database connection] that is created.  The idea here is that
-** xEntryPoint() is the entry point for a statically linked SQLite extension
+** xEntryPoint() is the entry point for a statically linked [SQLite extension]
 ** that is to be automatically loaded into all new database connections.
 **
 ** ^(Even though the function prototype shows that xEntryPoint() takes
 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
-** arguments and expects and integer result as if the signature of the
+** arguments and expects an integer result as if the signature of the
 ** entry point where as follows:
 **
 ** <blockquote><pre>
@@ -5287,9 +5975,22 @@ SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
 ** on the list of automatic extensions is a harmless no-op. ^No entry point
 ** will be called more than once for each database connection that is opened.
 **
-** See also: [sqlite3_reset_auto_extension()].
+** See also: [sqlite3_reset_auto_extension()]
+** and [sqlite3_cancel_auto_extension()]
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void(*xEntryPoint)(void));
+
+/*
+** CAPI3REF: Cancel Automatic Extension Loading
+**
+** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
+** initialization routine X that was registered using a prior call to
+** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
+** routine returns 1 if initialization routine X was successfully 
+** unregistered and it returns 0 if X was not on the list of initialization
+** routines.
 */
-SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
+SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
 
 /*
 ** CAPI3REF: Reset Automatic Extension Loading
@@ -5297,7 +5998,7 @@ SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
 ** ^This interface disables all automatic extensions previously
 ** registered using [sqlite3_auto_extension()].
 */
-SQLITE_API void sqlite3_reset_auto_extension(void);
+SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void);
 
 /*
 ** The interface to the virtual-table mechanism is currently considered
@@ -5399,6 +6100,17 @@ struct sqlite3_module {
 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
 **
+** The colUsed field indicates which columns of the virtual table may be
+** required by the current scan. Virtual table columns are numbered from
+** zero in the order in which they appear within the CREATE TABLE statement
+** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
+** the corresponding bit is set within the colUsed mask if the column may be
+** required by SQLite. If the table has at least 64 columns and any column
+** to the right of the first 63 is required, then bit 63 of colUsed is also
+** set. In other words, column iCol may be required if the expression
+** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 
+** non-zero.
+**
 ** The [xBestIndex] method must fill aConstraintUsage[] with information
 ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
 ** the right-hand side of the corresponding aConstraint[] is evaluated
@@ -5415,16 +6127,46 @@ struct sqlite3_module {
 ** the correct order to satisfy the ORDER BY clause so that no separate
 ** sorting step is required.
 **
-** ^The estimatedCost value is an estimate of the cost of doing the
-** particular lookup.  A full scan of a table with N entries should have
-** a cost of N.  A binary search of a table of N entries should have a
-** cost of approximately log(N).
+** ^The estimatedCost value is an estimate of the cost of a particular
+** strategy. A cost of N indicates that the cost of the strategy is similar
+** to a linear scan of an SQLite table with N rows. A cost of log(N) 
+** indicates that the expense of the operation is similar to that of a
+** binary search on a unique indexed field of an SQLite table with N rows.
+**
+** ^The estimatedRows value is an estimate of the number of rows that
+** will be returned by the strategy.
+**
+** The xBestIndex method may optionally populate the idxFlags field with a 
+** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
+** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
+** assumes that the strategy may visit at most one row. 
+**
+** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
+** SQLite also assumes that if a call to the xUpdate() method is made as
+** part of the same statement to delete or update a virtual table row and the
+** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
+** any database changes. In other words, if the xUpdate() returns
+** SQLITE_CONSTRAINT, the database contents must be exactly as they were
+** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
+** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
+** the xUpdate method are automatically rolled back by SQLite.
+**
+** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
+** structure for SQLite version 3.8.2. If a virtual table extension is
+** used with an SQLite version earlier than 3.8.2, the results of attempting 
+** to read or write the estimatedRows field are undefined (but are likely 
+** to included crashing the application). The estimatedRows field should
+** therefore only be used if [sqlite3_libversion_number()] returns a
+** value greater than or equal to 3008002. Similarly, the idxFlags field
+** was added for version 3.9.0. It may therefore only be used if
+** sqlite3_libversion_number() returns a value greater than or equal to
+** 3009000.
 */
 struct sqlite3_index_info {
   /* Inputs */
   int nConstraint;           /* Number of entries in aConstraint */
   struct sqlite3_index_constraint {
-     int iColumn;              /* Column on left-hand side of constraint */
+     int iColumn;              /* Column constrained.  -1 for ROWID */
      unsigned char op;         /* Constraint operator */
      unsigned char usable;     /* True if this constraint is usable */
      int iTermOffset;          /* Used internally - xBestIndex should ignore */
@@ -5443,10 +6185,21 @@ struct sqlite3_index_info {
   char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
   int orderByConsumed;       /* True if output is already ordered */
-  double estimatedCost;      /* Estimated cost of using this index */
+  double estimatedCost;           /* Estimated cost of using this index */
+  /* Fields below are only available in SQLite 3.8.2 and later */
+  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
+  /* Fields below are only available in SQLite 3.9.0 and later */
+  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
+  /* Fields below are only available in SQLite 3.10.0 and later */
+  sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
 };
 
 /*
+** CAPI3REF: Virtual Table Scan Flags
+*/
+#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */
+
+/*
 ** CAPI3REF: Virtual Table Constraint Operator Codes
 **
 ** These macros defined the allowed values for the
@@ -5454,15 +6207,19 @@ struct sqlite3_index_info {
 ** an operator that is part of a constraint term in the wHERE clause of
 ** a query that uses a [virtual table].
 */
-#define SQLITE_INDEX_CONSTRAINT_EQ    2
-#define SQLITE_INDEX_CONSTRAINT_GT    4
-#define SQLITE_INDEX_CONSTRAINT_LE    8
-#define SQLITE_INDEX_CONSTRAINT_LT    16
-#define SQLITE_INDEX_CONSTRAINT_GE    32
-#define SQLITE_INDEX_CONSTRAINT_MATCH 64
+#define SQLITE_INDEX_CONSTRAINT_EQ      2
+#define SQLITE_INDEX_CONSTRAINT_GT      4
+#define SQLITE_INDEX_CONSTRAINT_LE      8
+#define SQLITE_INDEX_CONSTRAINT_LT     16
+#define SQLITE_INDEX_CONSTRAINT_GE     32
+#define SQLITE_INDEX_CONSTRAINT_MATCH  64
+#define SQLITE_INDEX_CONSTRAINT_LIKE   65
+#define SQLITE_INDEX_CONSTRAINT_GLOB   66
+#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
 
 /*
 ** CAPI3REF: Register A Virtual Table Implementation
+** METHOD: sqlite3
 **
 ** ^These routines are used to register a new [virtual table module] name.
 ** ^Module names must be registered before
@@ -5486,13 +6243,13 @@ struct sqlite3_index_info {
 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
 ** destructor.
 */
-SQLITE_API int sqlite3_create_module(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
   sqlite3 *db,               /* SQLite connection to register module with */
   const char *zName,         /* Name of the module */
   const sqlite3_module *p,   /* Methods for the module */
   void *pClientData          /* Client data for xCreate/xConnect */
 );
-SQLITE_API int sqlite3_create_module_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
   sqlite3 *db,               /* SQLite connection to register module with */
   const char *zName,         /* Name of the module */
   const sqlite3_module *p,   /* Methods for the module */
@@ -5520,7 +6277,7 @@ SQLITE_API int sqlite3_create_module_v2(
 */
 struct sqlite3_vtab {
   const sqlite3_module *pModule;  /* The module for this virtual table */
-  int nRef;                       /* NO LONGER USED */
+  int nRef;                       /* Number of open cursors */
   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
   /* Virtual table implementations will typically add additional fields */
 };
@@ -5555,10 +6312,11 @@ struct sqlite3_vtab_cursor {
 ** to declare the format (the names and datatypes of the columns) of
 ** the virtual tables they implement.
 */
-SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
+SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL);
 
 /*
 ** CAPI3REF: Overload A Function For A Virtual Table
+** METHOD: sqlite3
 **
 ** ^(Virtual tables can provide alternative implementations of functions
 ** using the [xFindFunction] method of the [virtual table module].  
@@ -5573,7 +6331,7 @@ SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
 ** purpose is to be a placeholder function that can be overloaded
 ** by a [virtual table].
 */
-SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
+SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
 
 /*
 ** The interface to the virtual-table mechanism defined above (back up
@@ -5601,6 +6359,8 @@ typedef struct sqlite3_blob sqlite3_blob;
 
 /*
 ** CAPI3REF: Open A BLOB For Incremental I/O
+** METHOD: sqlite3
+** CONSTRUCTOR: sqlite3_blob
 **
 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
 ** in row iRow, column zColumn, table zTable in database zDb;
@@ -5610,26 +6370,42 @@ typedef struct sqlite3_blob sqlite3_blob;
 **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
 ** </pre>)^
 **
+** ^(Parameter zDb is not the filename that contains the database, but 
+** rather the symbolic name of the database. For attached databases, this is
+** the name that appears after the AS keyword in the [ATTACH] statement.
+** For the main database file, the database name is "main". For TEMP
+** tables, the database name is "temp".)^
+**
 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
-** and write access. ^If it is zero, the BLOB is opened for read access.
-** ^It is not possible to open a column that is part of an index or primary 
-** key for writing. ^If [foreign key constraints] are enabled, it is 
-** not possible to open a column that is part of a [child key] for writing.
-**
-** ^Note that the database name is not the filename that contains
-** the database but rather the symbolic name of the database that
-** appears after the AS keyword when the database is connected using [ATTACH].
-** ^For the main database file, the database name is "main".
-** ^For TEMP tables, the database name is "temp".
-**
-** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
-** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
-** to be a null pointer.)^
-** ^This function sets the [database connection] error code and message
-** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
-** functions. ^Note that the *ppBlob variable is always initialized in a
-** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
-** regardless of the success or failure of this routine.
+** and write access. ^If the flags parameter is zero, the BLOB is opened for
+** read-only access.
+**
+** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
+** in *ppBlob. Otherwise an [error code] is returned and, unless the error
+** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
+** the API is not misused, it is always safe to call [sqlite3_blob_close()] 
+** on *ppBlob after this function it returns.
+**
+** This function fails with SQLITE_ERROR if any of the following are true:
+** <ul>
+**   <li> ^(Database zDb does not exist)^, 
+**   <li> ^(Table zTable does not exist within database zDb)^, 
+**   <li> ^(Table zTable is a WITHOUT ROWID table)^, 
+**   <li> ^(Column zColumn does not exist)^,
+**   <li> ^(Row iRow is not present in the table)^,
+**   <li> ^(The specified column of row iRow contains a value that is not
+**         a TEXT or BLOB value)^,
+**   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 
+**         constraint and the blob is being opened for read/write access)^,
+**   <li> ^([foreign key constraints | Foreign key constraints] are enabled, 
+**         column zColumn is part of a [child key] definition and the blob is
+**         being opened for read/write access)^.
+** </ul>
+**
+** ^Unless it returns SQLITE_MISUSE, this function sets the 
+** [database connection] error code and message accessible via 
+** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 
+**
 **
 ** ^(If the row that a BLOB handle points to is modified by an
 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
@@ -5648,14 +6424,13 @@ typedef struct sqlite3_blob sqlite3_blob;
 ** blob.
 **
 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
-** and the built-in [zeroblob] SQL function can be used, if desired,
-** to create an empty, zero-filled blob in which to read or write using
-** this interface.
+** and the built-in [zeroblob] SQL function may be used to create a 
+** zero-filled blob to read or write using the incremental-blob interface.
 **
 ** To avoid a resource leak, every open [BLOB handle] should eventually
 ** be released by a call to [sqlite3_blob_close()].
 */
-SQLITE_API int sqlite3_blob_open(
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_open(
   sqlite3*,
   const char *zDb,
   const char *zTable,
@@ -5667,6 +6442,7 @@ SQLITE_API int sqlite3_blob_open(
 
 /*
 ** CAPI3REF: Move a BLOB Handle to a New Row
+** METHOD: sqlite3_blob
 **
 ** ^This function is used to move an existing blob handle so that it points
 ** to a different row of the same database table. ^The new row is identified
@@ -5687,34 +6463,34 @@ SQLITE_API int sqlite3_blob_open(
 **
 ** ^This function sets the database handle error code and message.
 */
-SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
 
 /*
 ** CAPI3REF: Close A BLOB Handle
+** DESTRUCTOR: sqlite3_blob
 **
-** ^Closes an open [BLOB handle].
+** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
+** unconditionally.  Even if this routine returns an error code, the 
+** handle is still closed.)^
 **
-** ^Closing a BLOB shall cause the current transaction to commit
-** if there are no other BLOBs, no pending prepared statements, and the
-** database connection is in [autocommit mode].
-** ^If any writes were made to the BLOB, they might be held in cache
-** until the close operation if they will fit.
+** ^If the blob handle being closed was opened for read-write access, and if
+** the database is in auto-commit mode and there are no other open read-write
+** blob handles or active write statements, the current transaction is
+** committed. ^If an error occurs while committing the transaction, an error
+** code is returned and the transaction rolled back.
 **
-** ^(Closing the BLOB often forces the changes
-** out to disk and so if any I/O errors occur, they will likely occur
-** at the time when the BLOB is closed.  Any errors that occur during
-** closing are reported as a non-zero return value.)^
-**
-** ^(The BLOB is closed unconditionally.  Even if this routine returns
-** an error code, the BLOB is still closed.)^
-**
-** ^Calling this routine with a null pointer (such as would be returned
-** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
+** Calling this function with an argument that is not a NULL pointer or an
+** open blob handle results in undefined behaviour. ^Calling this routine 
+** with a null pointer (such as would be returned by a failed call to 
+** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
+** is passed a valid open blob handle, the values returned by the 
+** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
 */
-SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *);
 
 /*
 ** CAPI3REF: Return The Size Of An Open BLOB
+** METHOD: sqlite3_blob
 **
 ** ^Returns the size in bytes of the BLOB accessible via the 
 ** successfully opened [BLOB handle] in its only argument.  ^The
@@ -5726,10 +6502,11 @@ SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
 ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
 ** to this routine results in undefined and probably undesirable behavior.
 */
-SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *);
 
 /*
 ** CAPI3REF: Read Data From A BLOB Incrementally
+** METHOD: sqlite3_blob
 **
 ** ^(This function is used to read data from an open [BLOB handle] into a
 ** caller-supplied buffer. N bytes of data are copied into buffer Z
@@ -5754,26 +6531,33 @@ SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
 **
 ** See also: [sqlite3_blob_write()].
 */
-SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
 
 /*
 ** CAPI3REF: Write Data Into A BLOB Incrementally
+** METHOD: sqlite3_blob
 **
-** ^This function is used to write data into an open [BLOB handle] from a
-** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
-** into the open BLOB, starting at offset iOffset.
+** ^(This function is used to write data into an open [BLOB handle] from a
+** caller-supplied buffer. N bytes of data are copied from the buffer Z
+** into the open BLOB, starting at offset iOffset.)^
+**
+** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
+** Otherwise, an  [error code] or an [extended error code] is returned.)^
+** ^Unless SQLITE_MISUSE is returned, this function sets the 
+** [database connection] error code and message accessible via 
+** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 
 **
 ** ^If the [BLOB handle] passed as the first argument was not opened for
 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
 ** this function returns [SQLITE_READONLY].
 **
-** ^This function may only modify the contents of the BLOB; it is
+** This function may only modify the contents of the BLOB; it is
 ** not possible to increase the size of a BLOB using this API.
 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
-** [SQLITE_ERROR] is returned and no data is written.  ^If N is
-** less than zero [SQLITE_ERROR] is returned and no data is written.
-** The size of the BLOB (and hence the maximum value of N+iOffset)
-** can be determined using the [sqlite3_blob_bytes()] interface.
+** [SQLITE_ERROR] is returned and no data is written. The size of the 
+** BLOB (and hence the maximum value of N+iOffset) can be determined 
+** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 
+** than zero [SQLITE_ERROR] is returned and no data is written.
 **
 ** ^An attempt to write to an expired [BLOB handle] fails with an
 ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
@@ -5782,9 +6566,6 @@ SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
 ** have been overwritten by the statement that expired the BLOB handle
 ** or by other independent statements.
 **
-** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
-** Otherwise, an  [error code] or an [extended error code] is returned.)^
-**
 ** This routine only works on a [BLOB handle] which has been created
 ** by a prior successful call to [sqlite3_blob_open()] and which has not
 ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
@@ -5792,7 +6573,7 @@ SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
 **
 ** See also: [sqlite3_blob_read()].
 */
-SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
 
 /*
 ** CAPI3REF: Virtual File System Objects
@@ -5823,9 +6604,9 @@ SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOff
 ** ^(If the default VFS is unregistered, another VFS is chosen as
 ** the default.  The choice for the new VFS is arbitrary.)^
 */
-SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
-SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
-SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
+SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName);
+SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
+SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*);
 
 /*
 ** CAPI3REF: Mutexes
@@ -5837,46 +6618,51 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 **
 ** The SQLite source code contains multiple implementations
 ** of these mutex routines.  An appropriate implementation
-** is selected automatically at compile-time.  ^(The following
+** is selected automatically at compile-time.  The following
 ** implementations are available in the SQLite core:
 **
 ** <ul>
-** <li>   SQLITE_MUTEX_OS2
-** <li>   SQLITE_MUTEX_PTHREAD
+** <li>   SQLITE_MUTEX_PTHREADS
 ** <li>   SQLITE_MUTEX_W32
 ** <li>   SQLITE_MUTEX_NOOP
-** </ul>)^
+** </ul>
 **
-** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
+** The SQLITE_MUTEX_NOOP implementation is a set of routines
 ** that does no real locking and is appropriate for use in
-** a single-threaded application.  ^The SQLITE_MUTEX_OS2,
-** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
-** are appropriate for use on OS/2, Unix, and Windows.
+** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
+** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
+** and Windows.
 **
-** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
+** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
 ** implementation is included with the library. In this case the
 ** application must supply a custom mutex implementation using the
 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
 ** before calling sqlite3_initialize() or any other public sqlite3_
-** function that calls sqlite3_initialize().)^
+** function that calls sqlite3_initialize().
 **
 ** ^The sqlite3_mutex_alloc() routine allocates a new
-** mutex and returns a pointer to it. ^If it returns NULL
-** that means that a mutex could not be allocated.  ^SQLite
-** will unwind its stack and return an error.  ^(The argument
-** to sqlite3_mutex_alloc() is one of these integer constants:
+** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
+** routine returns NULL if it is unable to allocate the requested
+** mutex.  The argument to sqlite3_mutex_alloc() must one of these
+** integer constants:
 **
 ** <ul>
 ** <li>  SQLITE_MUTEX_FAST
 ** <li>  SQLITE_MUTEX_RECURSIVE
 ** <li>  SQLITE_MUTEX_STATIC_MASTER
 ** <li>  SQLITE_MUTEX_STATIC_MEM
-** <li>  SQLITE_MUTEX_STATIC_MEM2
+** <li>  SQLITE_MUTEX_STATIC_OPEN
 ** <li>  SQLITE_MUTEX_STATIC_PRNG
 ** <li>  SQLITE_MUTEX_STATIC_LRU
-** <li>  SQLITE_MUTEX_STATIC_LRU2
-** </ul>)^
+** <li>  SQLITE_MUTEX_STATIC_PMEM
+** <li>  SQLITE_MUTEX_STATIC_APP1
+** <li>  SQLITE_MUTEX_STATIC_APP2
+** <li>  SQLITE_MUTEX_STATIC_APP3
+** <li>  SQLITE_MUTEX_STATIC_VFS1
+** <li>  SQLITE_MUTEX_STATIC_VFS2
+** <li>  SQLITE_MUTEX_STATIC_VFS3
+** </ul>
 **
 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
 ** cause sqlite3_mutex_alloc() to create
@@ -5884,14 +6670,14 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
 ** The mutex implementation does not need to make a distinction
 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
-** not want to.  ^SQLite will only request a recursive mutex in
-** cases where it really needs one.  ^If a faster non-recursive mutex
+** not want to.  SQLite will only request a recursive mutex in
+** cases where it really needs one.  If a faster non-recursive mutex
 ** implementation is available on the host platform, the mutex subsystem
 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
 **
 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
-** a pointer to a static preexisting mutex.  ^Six static mutexes are
+** a pointer to a static preexisting mutex.  ^Nine static mutexes are
 ** used by the current version of SQLite.  Future versions of SQLite
 ** may add additional static mutexes.  Static mutexes are for internal
 ** use by SQLite only.  Applications that use SQLite mutexes should
@@ -5900,16 +6686,13 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 **
 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
-** returns a different mutex on every call.  ^But for the static
+** returns a different mutex on every call.  ^For the static
 ** mutex types, the same mutex is returned on every call that has
 ** the same type number.
 **
 ** ^The sqlite3_mutex_free() routine deallocates a previously
-** allocated dynamic mutex.  ^SQLite is careful to deallocate every
-** dynamic mutex that it allocates.  The dynamic mutexes must not be in
-** use when they are deallocated.  Attempting to deallocate a static
-** mutex results in undefined behavior.  ^SQLite never deallocates
-** a static mutex.
+** allocated dynamic mutex.  Attempting to deallocate a static
+** mutex results in undefined behavior.
 **
 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
 ** to enter a mutex.  ^If another thread is already within the mutex,
@@ -5917,23 +6700,21 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
 ** upon successful entry.  ^(Mutexes created using
 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
-** In such cases the,
+** In such cases, the
 ** mutex must be exited an equal number of times before another thread
-** can enter.)^  ^(If the same thread tries to enter any other
-** kind of mutex more than once, the behavior is undefined.
-** SQLite will never exhibit
-** such behavior in its own use of mutexes.)^
+** can enter.)^  If the same thread tries to enter any mutex other
+** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
 **
 ** ^(Some systems (for example, Windows 95) do not support the operation
 ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
-** will always return SQLITE_BUSY.  The SQLite core only ever uses
-** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
+** will always return SQLITE_BUSY. The SQLite core only ever uses
+** sqlite3_mutex_try() as an optimization so this is acceptable 
+** behavior.)^
 **
 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
-** previously entered by the same thread.   ^(The behavior
+** previously entered by the same thread.   The behavior
 ** is undefined if the mutex is not currently entered by the
-** calling thread or is not currently allocated.  SQLite will
-** never do either.)^
+** calling thread or is not currently allocated.
 **
 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
@@ -5941,11 +6722,11 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
 **
 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
 */
-SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
-SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
-SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
-SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
-SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
+SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int);
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*);
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*);
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*);
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*);
 
 /*
 ** CAPI3REF: Mutex Methods Object
@@ -5954,9 +6735,9 @@ SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
 ** used to allocate and use mutexes.
 **
 ** Usually, the default mutex implementations provided by SQLite are
-** sufficient, however the user has the option of substituting a custom
+** sufficient, however the application has the option of substituting a custom
 ** implementation for specialized deployments or systems for which SQLite
-** does not provide a suitable implementation. In this case, the user
+** does not provide a suitable implementation. In this case, the application
 ** creates and populates an instance of this structure to pass
 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
 ** Additionally, an instance of this structure can be used as an
@@ -5997,13 +6778,13 @@ SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
 ** (i.e. it is acceptable to provide an implementation that segfaults if
 ** it is passed a NULL pointer).
 **
-** The xMutexInit() method must be threadsafe.  ^It must be harmless to
+** The xMutexInit() method must be threadsafe.  It must be harmless to
 ** invoke xMutexInit() multiple times within the same process and without
 ** intervening calls to xMutexEnd().  Second and subsequent calls to
 ** xMutexInit() must be no-ops.
 **
-** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
-** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
+** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
+** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
 ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
 ** memory allocation for a fast or recursive mutex.
 **
@@ -6029,34 +6810,34 @@ struct sqlite3_mutex_methods {
 ** CAPI3REF: Mutex Verification Routines
 **
 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
-** are intended for use inside assert() statements.  ^The SQLite core
+** are intended for use inside assert() statements.  The SQLite core
 ** never uses these routines except inside an assert() and applications
-** are advised to follow the lead of the core.  ^The SQLite core only
+** are advised to follow the lead of the core.  The SQLite core only
 ** provides implementations for these routines when it is compiled
-** with the SQLITE_DEBUG flag.  ^External mutex implementations
+** with the SQLITE_DEBUG flag.  External mutex implementations
 ** are only required to provide these routines if SQLITE_DEBUG is
 ** defined and if NDEBUG is not defined.
 **
-** ^These routines should return true if the mutex in their argument
+** These routines should return true if the mutex in their argument
 ** is held or not held, respectively, by the calling thread.
 **
-** ^The implementation is not required to provided versions of these
+** The implementation is not required to provide versions of these
 ** routines that actually work. If the implementation does not provide working
 ** versions of these routines, it should at least provide stubs that always
 ** return true so that one does not get spurious assertion failures.
 **
-** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
+** If the argument to sqlite3_mutex_held() is a NULL pointer then
 ** the routine should return 1.   This seems counter-intuitive since
 ** clearly the mutex cannot be held if it does not exist.  But
 ** the reason the mutex does not exist is because the build is not
 ** using mutexes.  And we do not want the assert() containing the
 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
-** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
+** the appropriate thing to do.  The sqlite3_mutex_notheld()
 ** interface should also return 1 when given a NULL pointer.
 */
 #ifndef NDEBUG
-SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
-SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*);
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*);
 #endif
 
 /*
@@ -6079,9 +6860,16 @@ SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
 #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
 #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
 #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
+#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
+#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
+#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
+#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
+#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
+#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */
 
 /*
 ** CAPI3REF: Retrieve the mutex for a database connection
+** METHOD: sqlite3
 **
 ** ^This interface returns a pointer the [sqlite3_mutex] object that 
 ** serializes access to the [database connection] given in the argument
@@ -6089,10 +6877,11 @@ SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
 ** ^If the [threading mode] is Single-thread or Multi-thread then this
 ** routine returns a NULL pointer.
 */
-SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
+SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*);
 
 /*
 ** CAPI3REF: Low-Level Control Of Database Files
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_file_control()] interface makes a direct call to the
 ** xFileControl method for the [sqlite3_io_methods] object associated
@@ -6123,7 +6912,7 @@ SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
 **
 ** See also: [SQLITE_FCNTL_LOCKSTATE]
 */
-SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
+SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
 
 /*
 ** CAPI3REF: Testing Interface
@@ -6142,7 +6931,7 @@ SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*
 ** Unlike most of the SQLite API, this function is not guaranteed to
 ** operate consistently from one release to the next.
 */
-SQLITE_API int sqlite3_test_control(int op, ...);
+SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...);
 
 /*
 ** CAPI3REF: Testing Interface Operation Codes
@@ -6168,15 +6957,21 @@ SQLITE_API int sqlite3_test_control(int op, ...);
 #define SQLITE_TESTCTRL_RESERVE                 14
 #define SQLITE_TESTCTRL_OPTIMIZATIONS           15
 #define SQLITE_TESTCTRL_ISKEYWORD               16
-#define SQLITE_TESTCTRL_PGHDRSZ                 17
-#define SQLITE_TESTCTRL_SCRATCHMALLOC           18
-#define SQLITE_TESTCTRL_LOCALTIME_FAULT         19
-#define SQLITE_TESTCTRL_LAST                    19
+#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
+#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
+#define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
+#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
+#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
+#define SQLITE_TESTCTRL_BYTEORDER               22
+#define SQLITE_TESTCTRL_ISINIT                  23
+#define SQLITE_TESTCTRL_SORTER_MMAP             24
+#define SQLITE_TESTCTRL_IMPOSTER                25
+#define SQLITE_TESTCTRL_LAST                    25
 
 /*
 ** CAPI3REF: SQLite Runtime Status
 **
-** ^This interface is used to retrieve runtime status information
+** ^These interfaces are used to retrieve runtime status information
 ** about the performance of SQLite, and optionally to reset various
 ** highwater marks.  ^The first argument is an integer code for
 ** the specific parameter to measure.  ^(Recognized integer codes
@@ -6190,19 +6985,22 @@ SQLITE_API int sqlite3_test_control(int op, ...);
 ** ^(Other parameters record only the highwater mark and not the current
 ** value.  For these latter parameters nothing is written into *pCurrent.)^
 **
-** ^The sqlite3_status() routine returns SQLITE_OK on success and a
-** non-zero [error code] on failure.
+** ^The sqlite3_status() and sqlite3_status64() routines return
+** SQLITE_OK on success and a non-zero [error code] on failure.
 **
-** This routine is threadsafe but is not atomic.  This routine can be
-** called while other threads are running the same or different SQLite
-** interfaces.  However the values returned in *pCurrent and
-** *pHighwater reflect the status of SQLite at different points in time
-** and it is possible that another thread might change the parameter
-** in between the times when *pCurrent and *pHighwater are written.
+** If either the current value or the highwater mark is too large to
+** be represented by a 32-bit integer, then the values returned by
+** sqlite3_status() are undefined.
 **
 ** See also: [sqlite3_db_status()]
 */
-SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
+SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
+SQLITE_API int SQLITE_STDCALL sqlite3_status64(
+  int op,
+  sqlite3_int64 *pCurrent,
+  sqlite3_int64 *pHighwater,
+  int resetFlag
+);
 
 
 /*
@@ -6281,7 +7079,8 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 ** The value written into the *pCurrent parameter is undefined.</dd>)^
 **
 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
-** <dd>This parameter records the deepest parser stack.  It is only
+** <dd>The *pHighwater parameter records the deepest parser stack. 
+** The *pCurrent value is undefined.  The *pHighwater value is only
 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
 ** </dl>
 **
@@ -6300,6 +7099,7 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 
 /*
 ** CAPI3REF: Database Connection Status
+** METHOD: sqlite3
 **
 ** ^This interface is used to retrieve runtime status information 
 ** about a single [database connection].  ^The first argument is the
@@ -6320,7 +7120,7 @@ SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetF
 **
 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
 */
-SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
+SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 
 /*
 ** CAPI3REF: Status Parameters for database connections
@@ -6362,12 +7162,24 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 ** the current value is always zero.)^
 **
 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
-** <dd>This parameter returns the approximate number of of bytes of heap
+** <dd>This parameter returns the approximate number of bytes of heap
 ** memory used by all pager caches associated with the database connection.)^
 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
 **
+** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 
+** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
+** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
+** pager cache is shared between two or more connections the bytes of heap
+** memory used by that pager cache is divided evenly between the attached
+** connections.)^  In other words, if none of the pager caches associated
+** with the database connection are shared, this request returns the same
+** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
+** shared, the value returned by this call will be smaller than that returned
+** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
+** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
+**
 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
-** <dd>This parameter returns the approximate number of of bytes of heap
+** <dd>This parameter returns the approximate number of bytes of heap
 ** memory used to store the schema for all databases associated
 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 
 ** ^The full amount of memory used by the schemas is reported, even if the
@@ -6376,7 +7188,7 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
 **
 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
-** <dd>This parameter returns the approximate number of of bytes of heap
+** <dd>This parameter returns the approximate number of bytes of heap
 ** and lookaside memory used by all prepared statements associated with
 ** the database connection.)^
 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
@@ -6393,6 +7205,23 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 
 ** is always 0.
 ** </dd>
+**
+** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
+** <dd>This parameter returns the number of dirty cache entries that have
+** been written to disk. Specifically, the number of pages written to the
+** wal file in wal mode databases, or the number of pages written to the
+** database file in rollback mode databases. Any pages written as part of
+** transaction rollback or database recovery operations are not included.
+** If an IO or other error occurs while writing a page to disk, the effect
+** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
+** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
+** </dd>
+**
+** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
+** <dd>This parameter returns zero for the current value if and only if
+** all foreign key constraints (deferred or immediate) have been
+** resolved.)^  ^The highwater mark is always 0.
+** </dd>
 ** </dl>
 */
 #define SQLITE_DBSTATUS_LOOKASIDE_USED       0
@@ -6404,11 +7233,15 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
 #define SQLITE_DBSTATUS_CACHE_HIT            7
 #define SQLITE_DBSTATUS_CACHE_MISS           8
-#define SQLITE_DBSTATUS_MAX                  8   /* Largest defined DBSTATUS */
+#define SQLITE_DBSTATUS_CACHE_WRITE          9
+#define SQLITE_DBSTATUS_DEFERRED_FKS        10
+#define SQLITE_DBSTATUS_CACHE_USED_SHARED   11
+#define SQLITE_DBSTATUS_MAX                 11   /* Largest defined DBSTATUS */
 
 
 /*
 ** CAPI3REF: Prepared Statement Status
+** METHOD: sqlite3_stmt
 **
 ** ^(Each prepared statement maintains various
 ** [SQLITE_STMTSTATUS counters] that measure the number
@@ -6430,7 +7263,7 @@ SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int r
 **
 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
 */
-SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 
 /*
 ** CAPI3REF: Status Parameters for prepared statements
@@ -6458,11 +7291,21 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 ** A non-zero value in this counter may indicate an opportunity to
 ** improvement performance by adding permanent indices that do not
 ** need to be reinitialized each time the statement is run.</dd>
+**
+** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
+** <dd>^This is the number of virtual machine operations executed
+** by the prepared statement if that number is less than or equal
+** to 2147483647.  The number of virtual machine operations can be 
+** used as a proxy for the total work done by the prepared statement.
+** If the number of virtual machine operations exceeds 2147483647
+** then the value returned by this statement status code is undefined.
+** </dd>
 ** </dl>
 */
 #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
 #define SQLITE_STMTSTATUS_SORT              2
 #define SQLITE_STMTSTATUS_AUTOINDEX         3
+#define SQLITE_STMTSTATUS_VM_STEP           4
 
 /*
 ** CAPI3REF: Custom Page Cache Object
@@ -6473,17 +7316,33 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 ** sqlite3_pcache object except by holding and passing pointers
 ** to the object.
 **
-** See [sqlite3_pcache_methods] for additional information.
+** See [sqlite3_pcache_methods2] for additional information.
 */
 typedef struct sqlite3_pcache sqlite3_pcache;
 
 /*
+** CAPI3REF: Custom Page Cache Object
+**
+** The sqlite3_pcache_page object represents a single page in the
+** page cache.  The page cache will allocate instances of this
+** object.  Various methods of the page cache use pointers to instances
+** of this object as parameters or as their return value.
+**
+** See [sqlite3_pcache_methods2] for additional information.
+*/
+typedef struct sqlite3_pcache_page sqlite3_pcache_page;
+struct sqlite3_pcache_page {
+  void *pBuf;        /* The content of the page */
+  void *pExtra;      /* Extra information associated with the page */
+};
+
+/*
 ** CAPI3REF: Application Defined Page Cache.
 ** KEYWORDS: {page cache}
 **
-** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
+** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
 ** register an alternative page cache implementation by passing in an 
-** instance of the sqlite3_pcache_methods structure.)^
+** instance of the sqlite3_pcache_methods2 structure.)^
 ** In many applications, most of the heap memory allocated by 
 ** SQLite is used for the page cache.
 ** By implementing a 
@@ -6497,7 +7356,7 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** extreme measure that is only needed by the most demanding applications.
 ** The built-in page cache is recommended for most uses.
 **
-** ^(The contents of the sqlite3_pcache_methods structure are copied to an
+** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
 ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
 ** the application may discard the parameter after the call to
 ** [sqlite3_config()] returns.)^
@@ -6506,7 +7365,7 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** ^(The xInit() method is called once for each effective 
 ** call to [sqlite3_initialize()])^
 ** (usually only once during the lifetime of the process). ^(The xInit()
-** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
+** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
 ** The intent of the xInit() method is to set up global data structures 
 ** required by the custom page cache implementation. 
 ** ^(If the xInit() method is NULL, then the 
@@ -6533,17 +7392,15 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** SQLite will typically create one cache instance for each open database file,
 ** though this is not guaranteed. ^The
 ** first parameter, szPage, is the size in bytes of the pages that must
-** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
-** will the page size of the database file that is to be cached plus an
-** increment (here called "R") of less than 250.  SQLite will use the
-** extra R bytes on each page to store metadata about the underlying
-** database page on disk.  The value of R depends
+** be allocated by the cache.  ^szPage will always a power of two.  ^The
+** second parameter szExtra is a number of bytes of extra storage 
+** associated with each page cache entry.  ^The szExtra parameter will
+** a number less than 250.  SQLite will use the
+** extra szExtra bytes on each page to store metadata about the underlying
+** database page on disk.  The value passed into szExtra depends
 ** on the SQLite version, the target platform, and how SQLite was compiled.
-** ^(R is constant for a particular build of SQLite. Except, there are two
-** distinct values of R when SQLite is compiled with the proprietary
-** ZIPVFS extension.)^  ^The second argument to
-** xCreate(), bPurgeable, is true if the cache being created will
-** be used to cache database pages of a file stored on disk, or
+** ^The third argument to xCreate(), bPurgeable, is true if the cache being
+** created will be used to cache database pages of a file stored on disk, or
 ** false if it is used for an in-memory database. The cache implementation
 ** does not have to do anything special based with the value of bPurgeable;
 ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
@@ -6567,11 +7424,16 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** 
 ** [[the xFetch() page cache methods]]
 ** The xFetch() method locates a page in the cache and returns a pointer to 
-** the page, or a NULL pointer.
-** A "page", in this context, means a buffer of szPage bytes aligned at an
-** 8-byte boundary. The page to be fetched is determined by the key. ^The
-** minimum key value is 1.  After it has been retrieved using xFetch, the page 
-** is considered to be "pinned".
+** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
+** The pBuf element of the returned sqlite3_pcache_page object will be a
+** pointer to a buffer of szPage bytes used to store the content of a 
+** single database page.  The pExtra element of sqlite3_pcache_page will be
+** a pointer to the szExtra bytes of extra storage that SQLite has requested
+** for each entry in the page cache.
+**
+** The page to be fetched is determined by the key. ^The minimum key value
+** is 1.  After it has been retrieved using xFetch, the page is considered
+** to be "pinned".
 **
 ** If the requested page is already in the page cache, then the page cache
 ** implementation must return a pointer to the page buffer with its content
@@ -6580,7 +7442,7 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** parameter to help it determined what action to take:
 **
 ** <table border=1 width=85% align=center>
-** <tr><th> createFlag <th> Behaviour when page is not already in cache
+** <tr><th> createFlag <th> Behavior when page is not already in cache
 ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
 **                 Otherwise return NULL.
@@ -6624,8 +7486,37 @@ typedef struct sqlite3_pcache sqlite3_pcache;
 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
 ** All resources associated with the specified cache should be freed. ^After
 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
-** handle invalid, and will not use it with any other sqlite3_pcache_methods
+** handle invalid, and will not use it with any other sqlite3_pcache_methods2
 ** functions.
+**
+** [[the xShrink() page cache method]]
+** ^SQLite invokes the xShrink() method when it wants the page cache to
+** free up as much of heap memory as possible.  The page cache implementation
+** is not obligated to free any memory, but well-behaved implementations should
+** do their best.
+*/
+typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
+struct sqlite3_pcache_methods2 {
+  int iVersion;
+  void *pArg;
+  int (*xInit)(void*);
+  void (*xShutdown)(void*);
+  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
+  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
+  int (*xPagecount)(sqlite3_pcache*);
+  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
+  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
+  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 
+      unsigned oldKey, unsigned newKey);
+  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
+  void (*xDestroy)(sqlite3_pcache*);
+  void (*xShrink)(sqlite3_pcache*);
+};
+
+/*
+** This is the obsolete pcache_methods object that has now been replaced
+** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
+** retained in the header file for backwards compatibility only.
 */
 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
 struct sqlite3_pcache_methods {
@@ -6642,6 +7533,7 @@ struct sqlite3_pcache_methods {
   void (*xDestroy)(sqlite3_pcache*);
 };
 
+
 /*
 ** CAPI3REF: Online Backup Object
 **
@@ -6698,6 +7590,10 @@ typedef struct sqlite3_backup sqlite3_backup;
 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
 ** an error.
 **
+** ^A call to sqlite3_backup_init() will fail, returning NULL, if 
+** there is already a read or read-write transaction open on the 
+** destination database.
+**
 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
 ** returned and an error code and error message are stored in the
 ** destination [database connection] D.
@@ -6790,20 +7686,20 @@ typedef struct sqlite3_backup sqlite3_backup;
 ** is not a permanent error and does not affect the return value of
 ** sqlite3_backup_finish().
 **
-** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
+** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
 **
-** ^Each call to sqlite3_backup_step() sets two values inside
-** the [sqlite3_backup] object: the number of pages still to be backed
-** up and the total number of pages in the source database file.
-** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
-** retrieve these two values, respectively.
-**
-** ^The values returned by these functions are only updated by
-** sqlite3_backup_step(). ^If the source database is modified during a backup
-** operation, then the values are not updated to account for any extra
-** pages that need to be updated or the size of the source database file
-** changing.
+** ^The sqlite3_backup_remaining() routine returns the number of pages still
+** to be backed up at the conclusion of the most recent sqlite3_backup_step().
+** ^The sqlite3_backup_pagecount() routine returns the total number of pages
+** in the source database at the conclusion of the most recent
+** sqlite3_backup_step().
+** ^(The values returned by these functions are only updated by
+** sqlite3_backup_step(). If the source database is modified in a way that
+** changes the size of the source database or the number of pages remaining,
+** those changes are not reflected in the output of sqlite3_backup_pagecount()
+** and sqlite3_backup_remaining() until after the next
+** sqlite3_backup_step().)^
 **
 ** <b>Concurrent Usage of Database Handles</b>
 **
@@ -6836,19 +7732,20 @@ typedef struct sqlite3_backup sqlite3_backup;
 ** same time as another thread is invoking sqlite3_backup_step() it is
 ** possible that they return invalid values.
 */
-SQLITE_API sqlite3_backup *sqlite3_backup_init(
+SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init(
   sqlite3 *pDest,                        /* Destination database handle */
   const char *zDestName,                 /* Destination database name */
   sqlite3 *pSource,                      /* Source database handle */
   const char *zSourceName                /* Source database name */
 );
-SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
-SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
-SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
-SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage);
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p);
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p);
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p);
 
 /*
 ** CAPI3REF: Unlock Notification
+** METHOD: sqlite3
 **
 ** ^When running in shared-cache mode, a database operation may fail with
 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
@@ -6961,7 +7858,7 @@ SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
 ** the special "DROP TABLE/INDEX" case, the extended error code is just 
 ** SQLITE_LOCKED.)^
 */
-SQLITE_API int sqlite3_unlock_notify(
+SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
   sqlite3 *pBlocked,                          /* Waiting connection */
   void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
   void *pNotifyArg                            /* Argument to pass to xNotify */
@@ -6971,17 +7868,58 @@ SQLITE_API int sqlite3_unlock_notify(
 /*
 ** CAPI3REF: String Comparison
 **
-** ^The [sqlite3_strnicmp()] API allows applications and extensions to
-** compare the contents of two buffers containing UTF-8 strings in a
-** case-independent fashion, using the same definition of case independence 
-** that SQLite uses internally when comparing identifiers.
+** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
+** and extensions to compare the contents of two buffers containing UTF-8
+** strings in a case-independent fashion, using the same definition of "case
+** independence" that SQLite uses internally when comparing identifiers.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *);
+SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int);
+
+/*
+** CAPI3REF: String Globbing
+*
+** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
+** string X matches the [GLOB] pattern P.
+** ^The definition of [GLOB] pattern matching used in
+** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
+** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
+** is case sensitive.
+**
+** Note that this routine returns zero on a match and non-zero if the strings
+** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
+**
+** See also: [sqlite3_strlike()].
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr);
+
+/*
+** CAPI3REF: String LIKE Matching
+*
+** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
+** string X matches the [LIKE] pattern P with escape character E.
+** ^The definition of [LIKE] pattern matching used in
+** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
+** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
+** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
+** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
+** insensitive - equivalent upper and lower case ASCII characters match
+** one another.
+**
+** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
+** only ASCII characters are case folded.
+**
+** Note that this routine returns zero on a match and non-zero if the strings
+** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
+**
+** See also: [sqlite3_strglob()].
 */
-SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
+SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
 
 /*
 ** CAPI3REF: Error Logging Interface
 **
-** ^The [sqlite3_log()] interface writes a message into the error log
+** ^The [sqlite3_log()] interface writes a message into the [error log]
 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
 ** ^If logging is enabled, the zFormat string and subsequent arguments are
 ** used with [sqlite3_snprintf()] to generate the final output string.
@@ -6999,18 +7937,17 @@ SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
 ** a few hundred characters, it will be truncated to the length of the
 ** buffer.
 */
-SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
+SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...);
 
 /*
 ** CAPI3REF: Write-Ahead Log Commit Hook
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
-** will be invoked each time a database connection commits data to a
-** [write-ahead log] (i.e. whenever a transaction is committed in
-** [journal_mode | journal_mode=WAL mode]). 
+** is invoked each time data is committed to a database in wal mode.
 **
-** ^The callback is invoked by SQLite after the commit has taken place and 
-** the associated write-lock on the database released, so the implementation 
+** ^(The callback is invoked by SQLite after the commit has taken place and 
+** the associated write-lock on the database released)^, so the implementation 
 ** may read, write or [checkpoint] the database as required.
 **
 ** ^The first parameter passed to the callback function when it is invoked
@@ -7034,9 +7971,9 @@ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
 ** previously registered write-ahead log callback. ^Note that the
 ** [sqlite3_wal_autocheckpoint()] interface and the
 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
-** those overwrite any prior [sqlite3_wal_hook()] settings.
+** overwrite any prior [sqlite3_wal_hook()] settings.
 */
-SQLITE_API void *sqlite3_wal_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
   sqlite3*, 
   int(*)(void *,sqlite3*,const char*,int),
   void*
@@ -7044,6 +7981,7 @@ SQLITE_API void *sqlite3_wal_hook(
 
 /*
 ** CAPI3REF: Configure an auto-checkpoint
+** METHOD: sqlite3
 **
 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
@@ -7061,103 +7999,132 @@ SQLITE_API void *sqlite3_wal_hook(
 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
 ** from SQL.
 **
+** ^Checkpoints initiated by this mechanism are
+** [sqlite3_wal_checkpoint_v2|PASSIVE].
+**
 ** ^Every new [database connection] defaults to having the auto-checkpoint
 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
 ** pages.  The use of this interface
 ** is only necessary if the default setting is found to be suboptimal
 ** for a particular application.
 */
-SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
 
 /*
 ** CAPI3REF: Checkpoint a database
+** METHOD: sqlite3
 **
-** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
-** on [database connection] D to be [checkpointed].  ^If X is NULL or an
-** empty string, then a checkpoint is run on all databases of
-** connection D.  ^If the database connection D is not in
-** [WAL | write-ahead log mode] then this interface is a harmless no-op.
+** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
+** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
 **
-** ^The [wal_checkpoint pragma] can be used to invoke this interface
-** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
-** [wal_autocheckpoint pragma] can be used to cause this interface to be
-** run whenever the WAL reaches a certain size threshold.
+** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 
+** [write-ahead log] for database X on [database connection] D to be
+** transferred into the database file and for the write-ahead log to
+** be reset.  See the [checkpointing] documentation for addition
+** information.
 **
-** See also: [sqlite3_wal_checkpoint_v2()]
+** This interface used to be the only way to cause a checkpoint to
+** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
+** interface was added.  This interface is retained for backwards
+** compatibility and as a convenience for applications that need to manually
+** start a callback but which do not need the full power (and corresponding
+** complication) of [sqlite3_wal_checkpoint_v2()].
 */
-SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
 
 /*
 ** CAPI3REF: Checkpoint a database
+** METHOD: sqlite3
 **
-** Run a checkpoint operation on WAL database zDb attached to database 
-** handle db. The specific operation is determined by the value of the 
-** eMode parameter:
+** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
+** operation on database X of [database connection] D in mode M.  Status
+** information is written back into integers pointed to by L and C.)^
+** ^(The M parameter must be a valid [checkpoint mode]:)^
 **
 ** <dl>
 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
-**   Checkpoint as many frames as possible without waiting for any database 
-**   readers or writers to finish. Sync the db file if all frames in the log
-**   are checkpointed. This mode is the same as calling 
-**   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
+**   ^Checkpoint as many frames as possible without waiting for any database 
+**   readers or writers to finish, then sync the database file if all frames 
+**   in the log were checkpointed. ^The [busy-handler callback]
+**   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.  
+**   ^On the other hand, passive mode might leave the checkpoint unfinished
+**   if there are concurrent readers or writers.
 **
 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
-**   This mode blocks (calls the busy-handler callback) until there is no
+**   ^This mode blocks (it invokes the
+**   [sqlite3_busy_handler|busy-handler callback]) until there is no
 **   database writer and all readers are reading from the most recent database
-**   snapshot. It then checkpoints all frames in the log file and syncs the
-**   database file. This call blocks database writers while it is running,
-**   but not database readers.
+**   snapshot. ^It then checkpoints all frames in the log file and syncs the
+**   database file. ^This mode blocks new database writers while it is pending,
+**   but new database readers are allowed to continue unimpeded.
 **
 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
-**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 
-**   checkpointing the log file it blocks (calls the busy-handler callback)
-**   until all readers are reading from the database file only. This ensures 
-**   that the next client to write to the database file restarts the log file 
-**   from the beginning. This call blocks database writers while it is running,
-**   but not database readers.
+**   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
+**   that after checkpointing the log file it blocks (calls the 
+**   [busy-handler callback])
+**   until all readers are reading from the database file only. ^This ensures 
+**   that the next writer will restart the log file from the beginning.
+**   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
+**   database writer attempts while it is pending, but does not impede readers.
+**
+** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
+**   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
+**   addition that it also truncates the log file to zero bytes just prior
+**   to a successful return.
 ** </dl>
 **
-** If pnLog is not NULL, then *pnLog is set to the total number of frames in
-** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
-** the total number of checkpointed frames (including any that were already
-** checkpointed when this function is called). *pnLog and *pnCkpt may be
-** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
-** If no values are available because of an error, they are both set to -1
-** before returning to communicate this to the caller.
-**
-** All calls obtain an exclusive "checkpoint" lock on the database file. If
+** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
+** the log file or to -1 if the checkpoint could not run because
+** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
+** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
+** log file (including any that were already checkpointed before the function
+** was called) or to -1 if the checkpoint could not run due to an error or
+** because the database is not in WAL mode. ^Note that upon successful
+** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
+** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
+**
+** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
 ** any other process is running a checkpoint operation at the same time, the 
-** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 
+** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 
 ** busy-handler configured, it will not be invoked in this case.
 **
-** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 
-** "writer" lock on the database file. If the writer lock cannot be obtained
-** immediately, and a busy-handler is configured, it is invoked and the writer
-** lock retried until either the busy-handler returns 0 or the lock is
-** successfully obtained. The busy-handler is also invoked while waiting for
-** database readers as described above. If the busy-handler returns 0 before
+** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 
+** exclusive "writer" lock on the database file. ^If the writer lock cannot be
+** obtained immediately, and a busy-handler is configured, it is invoked and
+** the writer lock retried until either the busy-handler returns 0 or the lock
+** is successfully obtained. ^The busy-handler is also invoked while waiting for
+** database readers as described above. ^If the busy-handler returns 0 before
 ** the writer lock is obtained or while waiting for database readers, the
 ** checkpoint operation proceeds from that point in the same way as 
 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 
-** without blocking any further. SQLITE_BUSY is returned in this case.
+** without blocking any further. ^SQLITE_BUSY is returned in this case.
 **
-** If parameter zDb is NULL or points to a zero length string, then the
-** specified operation is attempted on all WAL databases. In this case the
-** values written to output parameters *pnLog and *pnCkpt are undefined. If 
+** ^If parameter zDb is NULL or points to a zero length string, then the
+** specified operation is attempted on all WAL databases [attached] to 
+** [database connection] db.  In this case the
+** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 
 ** an SQLITE_BUSY error is encountered when processing one or more of the 
 ** attached WAL databases, the operation is still attempted on any remaining 
-** attached databases and SQLITE_BUSY is returned to the caller. If any other 
+** attached databases and SQLITE_BUSY is returned at the end. ^If any other 
 ** error occurs while processing an attached database, processing is abandoned 
-** and the error code returned to the caller immediately. If no error 
+** and the error code is returned to the caller immediately. ^If no error 
 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 
 ** databases, SQLITE_OK is returned.
 **
-** If database zDb is the name of an attached database that is not in WAL
-** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
+** ^If database zDb is the name of an attached database that is not in WAL
+** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
 ** zDb is not NULL (or a zero length string) and is not the name of any
 ** attached database, SQLITE_ERROR is returned to the caller.
+**
+** ^Unless it returns SQLITE_MISUSE,
+** the sqlite3_wal_checkpoint_v2() interface
+** sets the error information that is queried by
+** [sqlite3_errcode()] and [sqlite3_errmsg()].
+**
+** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
+** from SQL.
 */
-SQLITE_API int sqlite3_wal_checkpoint_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
   sqlite3 *db,                    /* Database handle */
   const char *zDb,                /* Name of attached database (or NULL) */
   int eMode,                      /* SQLITE_CHECKPOINT_* value */
@@ -7166,16 +8133,18 @@ SQLITE_API int sqlite3_wal_checkpoint_v2(
 );
 
 /*
-** CAPI3REF: Checkpoint operation parameters
+** CAPI3REF: Checkpoint Mode Values
+** KEYWORDS: {checkpoint mode}
 **
-** These constants can be used as the 3rd parameter to
-** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
-** documentation for additional information about the meaning and use of
-** each of these values.
+** These constants define all valid values for the "checkpoint mode" passed
+** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
+** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
+** meaning of each of these checkpoint modes.
 */
-#define SQLITE_CHECKPOINT_PASSIVE 0
-#define SQLITE_CHECKPOINT_FULL    1
-#define SQLITE_CHECKPOINT_RESTART 2
+#define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
+#define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
+#define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */
+#define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */
 
 /*
 ** CAPI3REF: Virtual Table Interface Configuration
@@ -7191,7 +8160,7 @@ SQLITE_API int sqlite3_wal_checkpoint_v2(
 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
 ** may be added in the future.
 */
-SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
+SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...);
 
 /*
 ** CAPI3REF: Virtual Table Configuration Options
@@ -7244,10 +8213,11 @@ SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
 ** of the SQL statement that triggered the call to the [xUpdate] method of the
 ** [virtual table].
 */
-SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
+SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *);
 
 /*
 ** CAPI3REF: Conflict resolution modes
+** KEYWORDS: {conflict resolution mode}
 **
 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
@@ -7263,7 +8233,380 @@ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
 /* #define SQLITE_ABORT 4  // Also an error code */
 #define SQLITE_REPLACE  5
 
+/*
+** CAPI3REF: Prepared Statement Scan Status Opcodes
+** KEYWORDS: {scanstatus options}
+**
+** The following constants can be used for the T parameter to the
+** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
+** different metric for sqlite3_stmt_scanstatus() to return.
+**
+** When the value returned to V is a string, space to hold that string is
+** managed by the prepared statement S and will be automatically freed when
+** S is finalized.
+**
+** <dl>
+** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
+** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
+** set to the total number of times that the X-th loop has run.</dd>
+**
+** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
+** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
+** to the total number of rows examined by all iterations of the X-th loop.</dd>
+**
+** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
+** <dd>^The "double" variable pointed to by the T parameter will be set to the
+** query planner's estimate for the average number of rows output from each
+** iteration of the X-th loop.  If the query planner's estimates was accurate,
+** then this value will approximate the quotient NVISIT/NLOOP and the
+** product of this value for all prior loops with the same SELECTID will
+** be the NLOOP value for the current loop.
+**
+** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
+** <dd>^The "const char *" variable pointed to by the T parameter will be set
+** to a zero-terminated UTF-8 string containing the name of the index or table
+** used for the X-th loop.
+**
+** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
+** <dd>^The "const char *" variable pointed to by the T parameter will be set
+** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
+** description for the X-th loop.
+**
+** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
+** <dd>^The "int" variable pointed to by the T parameter will be set to the
+** "select-id" for the X-th loop.  The select-id identifies which query or
+** subquery the loop is part of.  The main query has a select-id of zero.
+** The select-id is the same value as is output in the first column
+** of an [EXPLAIN QUERY PLAN] query.
+** </dl>
+*/
+#define SQLITE_SCANSTAT_NLOOP    0
+#define SQLITE_SCANSTAT_NVISIT   1
+#define SQLITE_SCANSTAT_EST      2
+#define SQLITE_SCANSTAT_NAME     3
+#define SQLITE_SCANSTAT_EXPLAIN  4
+#define SQLITE_SCANSTAT_SELECTID 5
+
+/*
+** CAPI3REF: Prepared Statement Scan Status
+** METHOD: sqlite3_stmt
+**
+** This interface returns information about the predicted and measured
+** performance for pStmt.  Advanced applications can use this
+** interface to compare the predicted and the measured performance and
+** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
+**
+** Since this interface is expected to be rarely used, it is only
+** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
+** compile-time option.
+**
+** The "iScanStatusOp" parameter determines which status information to return.
+** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
+** of this interface is undefined.
+** ^The requested measurement is written into a variable pointed to by
+** the "pOut" parameter.
+** Parameter "idx" identifies the specific loop to retrieve statistics for.
+** Loops are numbered starting from zero. ^If idx is out of range - less than
+** zero or greater than or equal to the total number of loops used to implement
+** the statement - a non-zero value is returned and the variable that pOut
+** points to is unchanged.
+**
+** ^Statistics might not be available for all loops in all statements. ^In cases
+** where there exist loops with no available statistics, this function behaves
+** as if the loop did not exist - it returns non-zero and leave the variable
+** that pOut points to unchanged.
+**
+** See also: [sqlite3_stmt_scanstatus_reset()]
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus(
+  sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */
+  int idx,                  /* Index of loop to report on */
+  int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
+  void *pOut                /* Result written here */
+);     
+
+/*
+** CAPI3REF: Zero Scan-Status Counters
+** METHOD: sqlite3_stmt
+**
+** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
+**
+** This API is only available if the library is built with pre-processor
+** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
+
+/*
+** CAPI3REF: Flush caches to disk mid-transaction
+**
+** ^If a write-transaction is open on [database connection] D when the
+** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
+** pages in the pager-cache that are not currently in use are written out 
+** to disk. A dirty page may be in use if a database cursor created by an
+** active SQL statement is reading from it, or if it is page 1 of a database
+** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]
+** interface flushes caches for all schemas - "main", "temp", and
+** any [attached] databases.
+**
+** ^If this function needs to obtain extra database locks before dirty pages 
+** can be flushed to disk, it does so. ^If those locks cannot be obtained 
+** immediately and there is a busy-handler callback configured, it is invoked
+** in the usual manner. ^If the required lock still cannot be obtained, then
+** the database is skipped and an attempt made to flush any dirty pages
+** belonging to the next (if any) database. ^If any databases are skipped
+** because locks cannot be obtained, but no other error occurs, this
+** function returns SQLITE_BUSY.
+**
+** ^If any other error occurs while flushing dirty pages to disk (for
+** example an IO error or out-of-memory condition), then processing is
+** abandoned and an SQLite [error code] is returned to the caller immediately.
+**
+** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
+**
+** ^This function does not set the database handle error code or message
+** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*);
+
+/*
+** CAPI3REF: The pre-update hook.
+**
+** ^These interfaces are only available if SQLite is compiled using the
+** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
+**
+** ^The [sqlite3_preupdate_hook()] interface registers a callback function
+** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
+** on a [rowid table].
+** ^At most one preupdate hook may be registered at a time on a single
+** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
+** the previous setting.
+** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
+** with a NULL pointer as the second parameter.
+** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
+** the first parameter to callbacks.
+**
+** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate
+** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID]
+** tables.
+**
+** ^The second parameter to the preupdate callback is a pointer to
+** the [database connection] that registered the preupdate hook.
+** ^The third parameter to the preupdate callback is one of the constants
+** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
+** kind of update operation that is about to occur.
+** ^(The fourth parameter to the preupdate callback is the name of the
+** database within the database connection that is being modified.  This
+** will be "main" for the main database or "temp" for TEMP tables or 
+** the name given after the AS keyword in the [ATTACH] statement for attached
+** databases.)^
+** ^The fifth parameter to the preupdate callback is the name of the
+** table that is being modified.
+** ^The sixth parameter to the preupdate callback is the initial [rowid] of the
+** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is
+** undefined for SQLITE_INSERT changes.
+** ^The seventh parameter to the preupdate callback is the final [rowid] of
+** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is
+** undefined for SQLITE_DELETE changes.
+**
+** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
+** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
+** provide additional information about a preupdate event. These routines
+** may only be called from within a preupdate callback.  Invoking any of
+** these routines from outside of a preupdate callback or with a
+** [database connection] pointer that is different from the one supplied
+** to the preupdate callback results in undefined and probably undesirable
+** behavior.
+**
+** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
+** in the row that is being inserted, updated, or deleted.
+**
+** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row before it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
+** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row after it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
+** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
+** callback was invoked as a result of a direct insert, update, or delete
+** operation; or 1 for inserts, updates, or deletes invoked by top-level 
+** triggers; or 2 for changes resulting from triggers called by top-level
+** triggers; and so forth.
+**
+** See also:  [sqlite3_update_hook()]
+*/
+SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_preupdate_hook(
+  sqlite3 *db,
+  void(*xPreUpdate)(
+    void *pCtx,                   /* Copy of third arg to preupdate_hook() */
+    sqlite3 *db,                  /* Database handle */
+    int op,                       /* SQLITE_UPDATE, DELETE or INSERT */
+    char const *zDb,              /* Database name */
+    char const *zName,            /* Table name */
+    sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */
+    sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */
+  ),
+  void*
+);
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_count(sqlite3 *);
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_depth(sqlite3 *);
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
+
+/*
+** CAPI3REF: Low-level system error code
+**
+** ^Attempt to return the underlying operating system error code or error
+** number that caused the most recent I/O error or failure to open a file.
+** The return value is OS-dependent.  For example, on unix systems, after
+** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
+** called to get back the underlying "errno" that caused the problem, such
+** as ENOSPC, EAUTH, EISDIR, and so forth.  
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*);
+
+/*
+** CAPI3REF: Database Snapshot
+** KEYWORDS: {snapshot}
+** EXPERIMENTAL
+**
+** An instance of the snapshot object records the state of a [WAL mode]
+** database for some specific point in history.
+**
+** In [WAL mode], multiple [database connections] that are open on the
+** same database file can each be reading a different historical version
+** of the database file.  When a [database connection] begins a read
+** transaction, that connection sees an unchanging copy of the database
+** as it existed for the point in time when the transaction first started.
+** Subsequent changes to the database from other connections are not seen
+** by the reader until a new read transaction is started.
+**
+** The sqlite3_snapshot object records state information about an historical
+** version of the database file so that it is possible to later open a new read
+** transaction that sees that historical version of the database rather than
+** the most recent version.
+**
+** The constructor for this object is [sqlite3_snapshot_get()].  The
+** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
+** to an historical snapshot (if possible).  The destructor for 
+** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
+*/
+typedef struct sqlite3_snapshot sqlite3_snapshot;
+
+/*
+** CAPI3REF: Record A Database Snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
+** new [sqlite3_snapshot] object that records the current state of
+** schema S in database connection D.  ^On success, the
+** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
+** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
+** ^If schema S of [database connection] D is not a [WAL mode] database
+** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)]
+** leaves the *P value unchanged and returns an appropriate [error code].
+**
+** The [sqlite3_snapshot] object returned from a successful call to
+** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
+** to avoid a memory leak.
+**
+** The [sqlite3_snapshot_get()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get(
+  sqlite3 *db,
+  const char *zSchema,
+  sqlite3_snapshot **ppSnapshot
+);
+
+/*
+** CAPI3REF: Start a read transaction on an historical snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
+** read transaction for schema S of
+** [database connection] D such that the read transaction
+** refers to historical [snapshot] P, rather than the most
+** recent change to the database.
+** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
+** or an appropriate [error code] if it fails.
+**
+** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
+** the first operation following the [BEGIN] that takes the schema S
+** out of [autocommit mode].
+** ^In other words, schema S must not currently be in
+** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
+** database connection D must be out of [autocommit mode].
+** ^A [snapshot] will fail to open if it has been overwritten by a
+** [checkpoint].
+** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
+** database connection D does not know that the database file for
+** schema S is in [WAL mode].  A database connection might not know
+** that the database file is in [WAL mode] if there has been no prior
+** I/O on that database connection, or if the database entered [WAL mode] 
+** after the most recent I/O on the database connection.)^
+** (Hint: Run "[PRAGMA application_id]" against a newly opened
+** database connection in order to make it ready to use snapshots.)
+**
+** The [sqlite3_snapshot_open()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open(
+  sqlite3 *db,
+  const char *zSchema,
+  sqlite3_snapshot *pSnapshot
+);
+
+/*
+** CAPI3REF: Destroy a snapshot
+** EXPERIMENTAL
+**
+** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
+** The application must eventually free every [sqlite3_snapshot] object
+** using this routine to avoid a memory leak.
+**
+** The [sqlite3_snapshot_free()] interface is only available when the
+** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*);
 
+/*
+** CAPI3REF: Compare the ages of two snapshot handles.
+** EXPERIMENTAL
+**
+** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
+** of two valid snapshot handles. 
+**
+** If the two snapshot handles are not associated with the same database 
+** file, the result of the comparison is undefined. 
+**
+** Additionally, the result of the comparison is only valid if both of the
+** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
+** last time the wal file was deleted. The wal file is deleted when the
+** database is changed back to rollback mode or when the number of database
+** clients drops to zero. If either snapshot handle was obtained before the 
+** wal file was last deleted, the value returned by this function 
+** is undefined.
+**
+** Otherwise, this API returns a negative value if P1 refers to an older
+** snapshot than P2, zero if the two handles refer to the same database
+** snapshot, and a positive value if P1 is a newer snapshot than P2.
+*/
+SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_cmp(
+  sqlite3_snapshot *p1,
+  sqlite3_snapshot *p2
+);
 
 /*
 ** Undo the hack that converts floating point types to integer for
@@ -7276,8 +8619,9 @@ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
 #if 0
 }  /* End of the 'extern "C"' block */
 #endif
-#endif
+#endif /* SQLITE3_H */
 
+/******** Begin file sqlite3rtree.h *********/
 /*
 ** 2010 August 30
 **
@@ -7300,6 +8644,16 @@ extern "C" {
 #endif
 
 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
+typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
+
+/* The double-precision datatype used by RTree depends on the
+** SQLITE_RTREE_INT_ONLY compile-time option.
+*/
+#ifdef SQLITE_RTREE_INT_ONLY
+  typedef sqlite3_int64 sqlite3_rtree_dbl;
+#else
+  typedef double sqlite3_rtree_dbl;
+#endif
 
 /*
 ** Register a geometry callback named zGeom that can be used as part of an
@@ -7307,10 +8661,10 @@ typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
 **
 **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
 */
-SQLITE_API int sqlite3_rtree_geometry_callback(
+SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback(
   sqlite3 *db,
   const char *zGeom,
-  int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes),
+  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
   void *pContext
 );
 
@@ -7322,11 +8676,62 @@ SQLITE_API int sqlite3_rtree_geometry_callback(
 struct sqlite3_rtree_geometry {
   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
   int nParam;                     /* Size of array aParam[] */
-  double *aParam;                 /* Parameters passed to SQL geom function */
+  sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
   void *pUser;                    /* Callback implementation user data */
   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
 };
 
+/*
+** Register a 2nd-generation geometry callback named zScore that can be 
+** used as part of an R-Tree geometry query as follows:
+**
+**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback(
+  sqlite3 *db,
+  const char *zQueryFunc,
+  int (*xQueryFunc)(sqlite3_rtree_query_info*),
+  void *pContext,
+  void (*xDestructor)(void*)
+);
+
+
+/*
+** A pointer to a structure of the following type is passed as the 
+** argument to scored geometry callback registered using
+** sqlite3_rtree_query_callback().
+**
+** Note that the first 5 fields of this structure are identical to
+** sqlite3_rtree_geometry.  This structure is a subclass of
+** sqlite3_rtree_geometry.
+*/
+struct sqlite3_rtree_query_info {
+  void *pContext;                   /* pContext from when function registered */
+  int nParam;                       /* Number of function parameters */
+  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
+  void *pUser;                      /* callback can use this, if desired */
+  void (*xDelUser)(void*);          /* function to free pUser */
+  sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
+  unsigned int *anQueue;            /* Number of pending entries in the queue */
+  int nCoord;                       /* Number of coordinates */
+  int iLevel;                       /* Level of current node or entry */
+  int mxLevel;                      /* The largest iLevel value in the tree */
+  sqlite3_int64 iRowid;             /* Rowid for current entry */
+  sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
+  int eParentWithin;                /* Visibility of parent node */
+  int eWithin;                      /* OUT: Visiblity */
+  sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
+  /* The following fields are only available in 3.8.11 and later */
+  sqlite3_value **apSqlParam;       /* Original SQL values of parameters */
+};
+
+/*
+** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
+*/
+#define NOT_WITHIN       0   /* Object completely outside of query region */
+#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
+#define FULLY_WITHIN     2   /* Object fully contained within query region */
+
 
 #if 0
 }  /* end of the 'extern "C"' block */
@@ -7334,9 +8739,2424 @@ struct sqlite3_rtree_geometry {
 
 #endif  /* ifndef _SQLITE3RTREE_H_ */
 
+/******** End of sqlite3rtree.h *********/
+/******** Begin file sqlite3session.h *********/
+
+#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
+#define __SQLITESESSION_H_ 1
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#if 0
+extern "C" {
+#endif
+
+
+/*
+** CAPI3REF: Session Object Handle
+*/
+typedef struct sqlite3_session sqlite3_session;
+
+/*
+** CAPI3REF: Changeset Iterator Handle
+*/
+typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
+
+/*
+** CAPI3REF: Create A New Session Object
+**
+** Create a new session object attached to database handle db. If successful,
+** a pointer to the new object is written to *ppSession and SQLITE_OK is
+** returned. If an error occurs, *ppSession is set to NULL and an SQLite
+** error code (e.g. SQLITE_NOMEM) is returned.
+**
+** It is possible to create multiple session objects attached to a single
+** database handle.
+**
+** Session objects created using this function should be deleted using the
+** [sqlite3session_delete()] function before the database handle that they
+** are attached to is itself closed. If the database handle is closed before
+** the session object is deleted, then the results of calling any session
+** module function, including [sqlite3session_delete()] on the session object
+** are undefined.
+**
+** Because the session module uses the [sqlite3_preupdate_hook()] API, it
+** is not possible for an application to register a pre-update hook on a
+** database handle that has one or more session objects attached. Nor is
+** it possible to create a session object attached to a database handle for
+** which a pre-update hook is already defined. The results of attempting 
+** either of these things are undefined.
+**
+** The session object will be used to create changesets for tables in
+** database zDb, where zDb is either "main", or "temp", or the name of an
+** attached database. It is not an error if database zDb is not attached
+** to the database when the session object is created.
+*/
+int sqlite3session_create(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of db (e.g. "main") */
+  sqlite3_session **ppSession     /* OUT: New session object */
+);
+
+/*
+** CAPI3REF: Delete A Session Object
+**
+** Delete a session object previously allocated using 
+** [sqlite3session_create()]. Once a session object has been deleted, the
+** results of attempting to use pSession with any other session module
+** function are undefined.
+**
+** Session objects must be deleted before the database handle to which they
+** are attached is closed. Refer to the documentation for 
+** [sqlite3session_create()] for details.
+*/
+void sqlite3session_delete(sqlite3_session *pSession);
+
+
+/*
+** CAPI3REF: Enable Or Disable A Session Object
+**
+** Enable or disable the recording of changes by a session object. When
+** enabled, a session object records changes made to the database. When
+** disabled - it does not. A newly created session object is enabled.
+** Refer to the documentation for [sqlite3session_changeset()] for further
+** details regarding how enabling and disabling a session object affects
+** the eventual changesets.
+**
+** Passing zero to this function disables the session. Passing a value
+** greater than zero enables it. Passing a value less than zero is a 
+** no-op, and may be used to query the current state of the session.
+**
+** The return value indicates the final state of the session object: 0 if 
+** the session is disabled, or 1 if it is enabled.
+*/
+int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
+
+/*
+** CAPI3REF: Set Or Clear the Indirect Change Flag
+**
+** Each change recorded by a session object is marked as either direct or
+** indirect. A change is marked as indirect if either:
+**
+** <ul>
+**   <li> The session object "indirect" flag is set when the change is
+**        made, or
+**   <li> The change is made by an SQL trigger or foreign key action 
+**        instead of directly as a result of a users SQL statement.
+** </ul>
+**
+** If a single row is affected by more than one operation within a session,
+** then the change is considered indirect if all operations meet the criteria
+** for an indirect change above, or direct otherwise.
+**
+** This function is used to set, clear or query the session object indirect
+** flag.  If the second argument passed to this function is zero, then the
+** indirect flag is cleared. If it is greater than zero, the indirect flag
+** is set. Passing a value less than zero does not modify the current value
+** of the indirect flag, and may be used to query the current state of the 
+** indirect flag for the specified session object.
+**
+** The return value indicates the final state of the indirect flag: 0 if 
+** it is clear, or 1 if it is set.
+*/
+int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
+
+/*
+** CAPI3REF: Attach A Table To A Session Object
+**
+** If argument zTab is not NULL, then it is the name of a table to attach
+** to the session object passed as the first argument. All subsequent changes 
+** made to the table while the session object is enabled will be recorded. See 
+** documentation for [sqlite3session_changeset()] for further details.
+**
+** Or, if argument zTab is NULL, then changes are recorded for all tables
+** in the database. If additional tables are added to the database (by 
+** executing "CREATE TABLE" statements) after this call is made, changes for 
+** the new tables are also recorded.
+**
+** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
+** defined as part of their CREATE TABLE statement. It does not matter if the 
+** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
+** KEY may consist of a single column, or may be a composite key.
+** 
+** It is not an error if the named table does not exist in the database. Nor
+** is it an error if the named table does not have a PRIMARY KEY. However,
+** no changes will be recorded in either of these scenarios.
+**
+** Changes are not recorded for individual rows that have NULL values stored
+** in one or more of their PRIMARY KEY columns.
+**
+** SQLITE_OK is returned if the call completes without error. Or, if an error 
+** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
+*/
+int sqlite3session_attach(
+  sqlite3_session *pSession,      /* Session object */
+  const char *zTab                /* Table name */
+);
+
+/*
+** CAPI3REF: Set a table filter on a Session Object.
+**
+** The second argument (xFilter) is the "filter callback". For changes to rows 
+** in tables that are not attached to the Session oject, the filter is called
+** to determine whether changes to the table's rows should be tracked or not. 
+** If xFilter returns 0, changes is not tracked. Note that once a table is 
+** attached, xFilter will not be called again.
+*/
+void sqlite3session_table_filter(
+  sqlite3_session *pSession,      /* Session object */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of third arg to _filter_table() */
+    const char *zTab              /* Table name */
+  ),
+  void *pCtx                      /* First argument passed to xFilter */
+);
+
+/*
+** CAPI3REF: Generate A Changeset From A Session Object
+**
+** Obtain a changeset containing changes to the tables attached to the 
+** session object passed as the first argument. If successful, 
+** set *ppChangeset to point to a buffer containing the changeset 
+** and *pnChangeset to the size of the changeset in bytes before returning
+** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
+** zero and return an SQLite error code.
+**
+** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
+** each representing a change to a single row of an attached table. An INSERT
+** change contains the values of each field of a new database row. A DELETE
+** contains the original values of each field of a deleted database row. An
+** UPDATE change contains the original values of each field of an updated
+** database row along with the updated values for each updated non-primary-key
+** column. It is not possible for an UPDATE change to represent a change that
+** modifies the values of primary key columns. If such a change is made, it
+** is represented in a changeset as a DELETE followed by an INSERT.
+**
+** Changes are not recorded for rows that have NULL values stored in one or 
+** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
+** no corresponding change is present in the changesets returned by this
+** function. If an existing row with one or more NULL values stored in
+** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
+** only an INSERT is appears in the changeset. Similarly, if an existing row
+** with non-NULL PRIMARY KEY values is updated so that one or more of its
+** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
+** DELETE change only.
+**
+** The contents of a changeset may be traversed using an iterator created
+** using the [sqlite3changeset_start()] API. A changeset may be applied to
+** a database with a compatible schema using the [sqlite3changeset_apply()]
+** API.
+**
+** Within a changeset generated by this function, all changes related to a
+** single table are grouped together. In other words, when iterating through
+** a changeset or when applying a changeset to a database, all changes related
+** to a single table are processed before moving on to the next table. Tables
+** are sorted in the same order in which they were attached (or auto-attached)
+** to the sqlite3_session object. The order in which the changes related to
+** a single table are stored is undefined.
+**
+** Following a successful call to this function, it is the responsibility of
+** the caller to eventually free the buffer that *ppChangeset points to using
+** [sqlite3_free()].
+**
+** <h3>Changeset Generation</h3>
+**
+** Once a table has been attached to a session object, the session object
+** records the primary key values of all new rows inserted into the table.
+** It also records the original primary key and other column values of any
+** deleted or updated rows. For each unique primary key value, data is only
+** recorded once - the first time a row with said primary key is inserted,
+** updated or deleted in the lifetime of the session.
+**
+** There is one exception to the previous paragraph: when a row is inserted,
+** updated or deleted, if one or more of its primary key columns contain a
+** NULL value, no record of the change is made.
+**
+** The session object therefore accumulates two types of records - those
+** that consist of primary key values only (created when the user inserts
+** a new record) and those that consist of the primary key values and the
+** original values of other table columns (created when the users deletes
+** or updates a record).
+**
+** When this function is called, the requested changeset is created using
+** both the accumulated records and the current contents of the database
+** file. Specifically:
+**
+** <ul>
+**   <li> For each record generated by an insert, the database is queried
+**        for a row with a matching primary key. If one is found, an INSERT
+**        change is added to the changeset. If no such row is found, no change 
+**        is added to the changeset.
+**
+**   <li> For each record generated by an update or delete, the database is 
+**        queried for a row with a matching primary key. If such a row is
+**        found and one or more of the non-primary key fields have been
+**        modified from their original values, an UPDATE change is added to 
+**        the changeset. Or, if no such row is found in the table, a DELETE 
+**        change is added to the changeset. If there is a row with a matching
+**        primary key in the database, but all fields contain their original
+**        values, no change is added to the changeset.
+** </ul>
+**
+** This means, amongst other things, that if a row is inserted and then later
+** deleted while a session object is active, neither the insert nor the delete
+** will be present in the changeset. Or if a row is deleted and then later a 
+** row with the same primary key values inserted while a session object is
+** active, the resulting changeset will contain an UPDATE change instead of
+** a DELETE and an INSERT.
+**
+** When a session object is disabled (see the [sqlite3session_enable()] API),
+** it does not accumulate records when rows are inserted, updated or deleted.
+** This may appear to have some counter-intuitive effects if a single row
+** is written to more than once during a session. For example, if a row
+** is inserted while a session object is enabled, then later deleted while 
+** the same session object is disabled, no INSERT record will appear in the
+** changeset, even though the delete took place while the session was disabled.
+** Or, if one field of a row is updated while a session is disabled, and 
+** another field of the same row is updated while the session is enabled, the
+** resulting changeset will contain an UPDATE change that updates both fields.
+*/
+int sqlite3session_changeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Load The Difference Between Tables Into A Session 
+**
+** If it is not already attached to the session object passed as the first
+** argument, this function attaches table zTbl in the same manner as the
+** [sqlite3session_attach()] function. If zTbl does not exist, or if it
+** does not have a primary key, this function is a no-op (but does not return
+** an error).
+**
+** Argument zFromDb must be the name of a database ("main", "temp" etc.)
+** attached to the same database handle as the session object that contains 
+** a table compatible with the table attached to the session by this function.
+** A table is considered compatible if it:
+**
+** <ul>
+**   <li> Has the same name,
+**   <li> Has the same set of columns declared in the same order, and
+**   <li> Has the same PRIMARY KEY definition.
+** </ul>
+**
+** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
+** are compatible but do not have any PRIMARY KEY columns, it is not an error
+** but no changes are added to the session object. As with other session
+** APIs, tables without PRIMARY KEYs are simply ignored.
+**
+** This function adds a set of changes to the session object that could be
+** used to update the table in database zFrom (call this the "from-table") 
+** so that its content is the same as the table attached to the session 
+** object (call this the "to-table"). Specifically:
+**
+** <ul>
+**   <li> For each row (primary key) that exists in the to-table but not in 
+**     the from-table, an INSERT record is added to the session object.
+**
+**   <li> For each row (primary key) that exists in the to-table but not in 
+**     the from-table, a DELETE record is added to the session object.
+**
+**   <li> For each row (primary key) that exists in both tables, but features 
+**     different in each, an UPDATE record is added to the session.
+** </ul>
+**
+** To clarify, if this function is called and then a changeset constructed
+** using [sqlite3session_changeset()], then after applying that changeset to 
+** database zFrom the contents of the two compatible tables would be 
+** identical.
+**
+** It an error if database zFrom does not exist or does not contain the
+** required compatible table.
+**
+** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
+** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
+** may be set to point to a buffer containing an English language error 
+** message. It is the responsibility of the caller to free this buffer using
+** sqlite3_free().
+*/
+int sqlite3session_diff(
+  sqlite3_session *pSession,
+  const char *zFromDb,
+  const char *zTbl,
+  char **pzErrMsg
+);
+
+
+/*
+** CAPI3REF: Generate A Patchset From A Session Object
+**
+** The differences between a patchset and a changeset are that:
+**
+** <ul>
+**   <li> DELETE records consist of the primary key fields only. The 
+**        original values of other fields are omitted.
+**   <li> The original values of any modified fields are omitted from 
+**        UPDATE records.
+** </ul>
+**
+** A patchset blob may be used with up to date versions of all 
+** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 
+** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
+** attempting to use a patchset blob with old versions of the
+** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 
+**
+** Because the non-primary key "old.*" fields are omitted, no 
+** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
+** is passed to the sqlite3changeset_apply() API. Other conflict types work
+** in the same way as for changesets.
+**
+** Changes within a patchset are ordered in the same way as for changesets
+** generated by the sqlite3session_changeset() function (i.e. all changes for
+** a single table are grouped together, tables appear in the order in which
+** they were attached to the session object).
+*/
+int sqlite3session_patchset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnPatchset,                /* OUT: Size of buffer at *ppChangeset */
+  void **ppPatchset               /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Test if a changeset has recorded any changes.
+**
+** Return non-zero if no changes to attached tables have been recorded by 
+** the session object passed as the first argument. Otherwise, if one or 
+** more changes have been recorded, return zero.
+**
+** Even if this function returns zero, it is possible that calling
+** [sqlite3session_changeset()] on the session handle may still return a
+** changeset that contains no changes. This can happen when a row in 
+** an attached table is modified and then later on the original values 
+** are restored. However, if this function returns non-zero, then it is
+** guaranteed that a call to sqlite3session_changeset() will return a 
+** changeset containing zero changes.
+*/
+int sqlite3session_isempty(sqlite3_session *pSession);
+
+/*
+** CAPI3REF: Create An Iterator To Traverse A Changeset 
+**
+** Create an iterator used to iterate through the contents of a changeset.
+** If successful, *pp is set to point to the iterator handle and SQLITE_OK
+** is returned. Otherwise, if an error occurs, *pp is set to zero and an
+** SQLite error code is returned.
+**
+** The following functions can be used to advance and query a changeset 
+** iterator created by this function:
+**
+** <ul>
+**   <li> [sqlite3changeset_next()]
+**   <li> [sqlite3changeset_op()]
+**   <li> [sqlite3changeset_new()]
+**   <li> [sqlite3changeset_old()]
+** </ul>
+**
+** It is the responsibility of the caller to eventually destroy the iterator
+** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
+** changeset (pChangeset) must remain valid until after the iterator is
+** destroyed.
+**
+** Assuming the changeset blob was created by one of the
+** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
+** [sqlite3changeset_invert()] functions, all changes within the changeset 
+** that apply to a single table are grouped together. This means that when 
+** an application iterates through a changeset using an iterator created by 
+** this function, all changes that relate to a single table are visted 
+** consecutively. There is no chance that the iterator will visit a change 
+** the applies to table X, then one for table Y, and then later on visit 
+** another change for table X.
+*/
+int sqlite3changeset_start(
+  sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */
+  int nChangeset,                 /* Size of changeset blob in bytes */
+  void *pChangeset                /* Pointer to blob containing changeset */
+);
+
+
+/*
+** CAPI3REF: Advance A Changeset Iterator
+**
+** This function may only be used with iterators created by function
+** [sqlite3changeset_start()]. If it is called on an iterator passed to
+** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
+** is returned and the call has no effect.
+**
+** Immediately after an iterator is created by sqlite3changeset_start(), it
+** does not point to any change in the changeset. Assuming the changeset
+** is not empty, the first call to this function advances the iterator to
+** point to the first change in the changeset. Each subsequent call advances
+** the iterator to point to the next change in the changeset (if any). If
+** no error occurs and the iterator points to a valid change after a call
+** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 
+** Otherwise, if all changes in the changeset have already been visited,
+** SQLITE_DONE is returned.
+**
+** If an error occurs, an SQLite error code is returned. Possible error 
+** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 
+** SQLITE_NOMEM.
+*/
+int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
+** is not the case, this function returns [SQLITE_MISUSE].
+**
+** If argument pzTab is not NULL, then *pzTab is set to point to a
+** nul-terminated utf-8 encoded string containing the name of the table
+** affected by the current change. The buffer remains valid until either
+** sqlite3changeset_next() is called on the iterator or until the 
+** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 
+** set to the number of columns in the table affected by the change. If
+** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
+** is an indirect change, or false (0) otherwise. See the documentation for
+** [sqlite3session_indirect()] for a description of direct and indirect
+** changes. Finally, if pOp is not NULL, then *pOp is set to one of 
+** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 
+** type of change that the iterator currently points to.
+**
+** If no error occurs, SQLITE_OK is returned. If an error does occur, an
+** SQLite error code is returned. The values of the output variables may not
+** be trusted in this case.
+*/
+int sqlite3changeset_op(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  const char **pzTab,             /* OUT: Pointer to table name */
+  int *pnCol,                     /* OUT: Number of columns in table */
+  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
+  int *pbIndirect                 /* OUT: True for an 'indirect' change */
+);
+
+/*
+** CAPI3REF: Obtain The Primary Key Definition Of A Table
+**
+** For each modified table, a changeset includes the following:
+**
+** <ul>
+**   <li> The number of columns in the table, and
+**   <li> Which of those columns make up the tables PRIMARY KEY.
+** </ul>
+**
+** This function is used to find which columns comprise the PRIMARY KEY of
+** the table modified by the change that iterator pIter currently points to.
+** If successful, *pabPK is set to point to an array of nCol entries, where
+** nCol is the number of columns in the table. Elements of *pabPK are set to
+** 0x01 if the corresponding column is part of the tables primary key, or
+** 0x00 if it is not.
+**
+** If argumet pnCol is not NULL, then *pnCol is set to the number of columns
+** in the table.
+**
+** If this function is called when the iterator does not point to a valid
+** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
+** SQLITE_OK is returned and the output variables populated as described
+** above.
+*/
+int sqlite3changeset_pk(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
+  int *pnCol                      /* OUT: Number of entries in output array */
+);
+
+/*
+** CAPI3REF: Obtain old.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** original row values stored as part of the UPDATE or DELETE change and
+** returns SQLITE_OK. The name of the function comes from the fact that this 
+** is similar to the "old.*" columns available to update or delete triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_old(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain new.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** new row values stored as part of the UPDATE or INSERT change and
+** returns SQLITE_OK. If the change is an UPDATE and does not include
+** a new value for the requested column, *ppValue is set to NULL and 
+** SQLITE_OK returned. The name of the function comes from the fact that 
+** this is similar to the "new.*" columns available to update or delete 
+** triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_new(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
+**
+** This function should only be used with iterator objects passed to a
+** conflict-handler callback by [sqlite3changeset_apply()] with either
+** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
+** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
+** is set to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the 
+** "conflicting row" associated with the current conflict-handler callback
+** and returns SQLITE_OK.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_conflict(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Value from conflicting row */
+);
+
+/*
+** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
+**
+** This function may only be called with an iterator passed to an
+** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
+** it sets the output variable to the total number of known foreign key
+** violations in the destination database and returns SQLITE_OK.
+**
+** In all other cases this function returns SQLITE_MISUSE.
+*/
+int sqlite3changeset_fk_conflicts(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int *pnOut                      /* OUT: Number of FK violations */
+);
+
+
+/*
+** CAPI3REF: Finalize A Changeset Iterator
+**
+** This function is used to finalize an iterator allocated with
+** [sqlite3changeset_start()].
+**
+** This function should only be called on iterators created using the
+** [sqlite3changeset_start()] function. If an application calls this
+** function with an iterator passed to a conflict-handler by
+** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
+** call has no effect.
+**
+** If an error was encountered within a call to an sqlite3changeset_xxx()
+** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 
+** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
+** to that error is returned by this function. Otherwise, SQLITE_OK is
+** returned. This is to allow the following pattern (pseudo-code):
+**
+**   sqlite3changeset_start();
+**   while( SQLITE_ROW==sqlite3changeset_next() ){
+**     // Do something with change.
+**   }
+**   rc = sqlite3changeset_finalize();
+**   if( rc!=SQLITE_OK ){
+**     // An error has occurred 
+**   }
+*/
+int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Invert A Changeset
+**
+** This function is used to "invert" a changeset object. Applying an inverted
+** changeset to a database reverses the effects of applying the uninverted
+** changeset. Specifically:
+**
+** <ul>
+**   <li> Each DELETE change is changed to an INSERT, and
+**   <li> Each INSERT change is changed to a DELETE, and
+**   <li> For each UPDATE change, the old.* and new.* values are exchanged.
+** </ul>
+**
+** This function does not change the order in which changes appear within
+** the changeset. It merely reverses the sense of each individual change.
+**
+** If successful, a pointer to a buffer containing the inverted changeset
+** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
+** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
+** zeroed and an SQLite error code returned.
+**
+** It is the responsibility of the caller to eventually call sqlite3_free()
+** on the *ppOut pointer to free the buffer allocation following a successful 
+** call to this function.
+**
+** WARNING/TODO: This function currently assumes that the input is a valid
+** changeset. If it is not, the results are undefined.
+*/
+int sqlite3changeset_invert(
+  int nIn, const void *pIn,       /* Input changeset */
+  int *pnOut, void **ppOut        /* OUT: Inverse of input */
+);
+
+/*
+** CAPI3REF: Concatenate Two Changeset Objects
+**
+** This function is used to concatenate two changesets, A and B, into a 
+** single changeset. The result is a changeset equivalent to applying
+** changeset A followed by changeset B. 
+**
+** This function combines the two input changesets using an 
+** sqlite3_changegroup object. Calling it produces similar results as the
+** following code fragment:
+**
+**   sqlite3_changegroup *pGrp;
+**   rc = sqlite3_changegroup_new(&pGrp);
+**   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
+**   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
+**   if( rc==SQLITE_OK ){
+**     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
+**   }else{
+**     *ppOut = 0;
+**     *pnOut = 0;
+**   }
+**
+** Refer to the sqlite3_changegroup documentation below for details.
+*/
+int sqlite3changeset_concat(
+  int nA,                         /* Number of bytes in buffer pA */
+  void *pA,                       /* Pointer to buffer containing changeset A */
+  int nB,                         /* Number of bytes in buffer pB */
+  void *pB,                       /* Pointer to buffer containing changeset B */
+  int *pnOut,                     /* OUT: Number of bytes in output changeset */
+  void **ppOut                    /* OUT: Buffer containing output changeset */
+);
+
+
+/*
+** Changegroup handle.
+*/
+typedef struct sqlite3_changegroup sqlite3_changegroup;
+
+/*
+** CAPI3REF: Combine two or more changesets into a single changeset.
+**
+** An sqlite3_changegroup object is used to combine two or more changesets
+** (or patchsets) into a single changeset (or patchset). A single changegroup
+** object may combine changesets or patchsets, but not both. The output is
+** always in the same format as the input.
+**
+** If successful, this function returns SQLITE_OK and populates (*pp) with
+** a pointer to a new sqlite3_changegroup object before returning. The caller
+** should eventually free the returned object using a call to 
+** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
+** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
+**
+** The usual usage pattern for an sqlite3_changegroup object is as follows:
+**
+** <ul>
+**   <li> It is created using a call to sqlite3changegroup_new().
+**
+**   <li> Zero or more changesets (or patchsets) are added to the object
+**        by calling sqlite3changegroup_add().
+**
+**   <li> The result of combining all input changesets together is obtained 
+**        by the application via a call to sqlite3changegroup_output().
+**
+**   <li> The object is deleted using a call to sqlite3changegroup_delete().
+** </ul>
+**
+** Any number of calls to add() and output() may be made between the calls to
+** new() and delete(), and in any order.
+**
+** As well as the regular sqlite3changegroup_add() and 
+** sqlite3changegroup_output() functions, also available are the streaming
+** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
+*/
+int sqlite3changegroup_new(sqlite3_changegroup **pp);
+
+/*
+** Add all changes within the changeset (or patchset) in buffer pData (size
+** nData bytes) to the changegroup. 
+**
+** If the buffer contains a patchset, then all prior calls to this function
+** on the same changegroup object must also have specified patchsets. Or, if
+** the buffer contains a changeset, so must have the earlier calls to this
+** function. Otherwise, SQLITE_ERROR is returned and no changes are added
+** to the changegroup.
+**
+** Rows within the changeset and changegroup are identified by the values in
+** their PRIMARY KEY columns. A change in the changeset is considered to
+** apply to the same row as a change already present in the changegroup if
+** the two rows have the same primary key.
+**
+** Changes to rows that that do not already appear in the changegroup are
+** simply copied into it. Or, if both the new changeset and the changegroup
+** contain changes that apply to a single row, the final contents of the
+** changegroup depends on the type of each change, as follows:
+**
+** <table border=1 style="margin-left:8ex;margin-right:8ex">
+**   <tr><th style="white-space:pre">Existing Change  </th>
+**       <th style="white-space:pre">New Change       </th>
+**       <th>Output Change
+**   <tr><td>INSERT <td>INSERT <td>
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   <tr><td>INSERT <td>UPDATE <td>
+**       The INSERT change remains in the changegroup. The values in the 
+**       INSERT change are modified as if the row was inserted by the
+**       existing change and then updated according to the new change.
+**   <tr><td>INSERT <td>DELETE <td>
+**       The existing INSERT is removed from the changegroup. The DELETE is
+**       not added.
+**   <tr><td>UPDATE <td>INSERT <td>
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   <tr><td>UPDATE <td>UPDATE <td>
+**       The existing UPDATE remains within the changegroup. It is amended 
+**       so that the accompanying values are as if the row was updated once 
+**       by the existing change and then again by the new change.
+**   <tr><td>UPDATE <td>DELETE <td>
+**       The existing UPDATE is replaced by the new DELETE within the
+**       changegroup.
+**   <tr><td>DELETE <td>INSERT <td>
+**       If one or more of the column values in the row inserted by the
+**       new change differ from those in the row deleted by the existing 
+**       change, the existing DELETE is replaced by an UPDATE within the
+**       changegroup. Otherwise, if the inserted row is exactly the same 
+**       as the deleted row, the existing DELETE is simply discarded.
+**   <tr><td>DELETE <td>UPDATE <td>
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+**   <tr><td>DELETE <td>DELETE <td>
+**       The new change is ignored. This case does not occur if the new
+**       changeset was recorded immediately after the changesets already
+**       added to the changegroup.
+** </table>
+**
+** If the new changeset contains changes to a table that is already present
+** in the changegroup, then the number of columns and the position of the
+** primary key columns for the table must be consistent. If this is not the
+** case, this function fails with SQLITE_SCHEMA. If the input changeset
+** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
+** returned. Or, if an out-of-memory condition occurs during processing, this
+** function returns SQLITE_NOMEM. In all cases, if an error occurs the
+** final contents of the changegroup is undefined.
+**
+** If no error occurs, SQLITE_OK is returned.
+*/
+int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
+
+/*
+** Obtain a buffer containing a changeset (or patchset) representing the
+** current contents of the changegroup. If the inputs to the changegroup
+** were themselves changesets, the output is a changeset. Or, if the
+** inputs were patchsets, the output is also a patchset.
+**
+** As with the output of the sqlite3session_changeset() and
+** sqlite3session_patchset() functions, all changes related to a single
+** table are grouped together in the output of this function. Tables appear
+** in the same order as for the very first changeset added to the changegroup.
+** If the second or subsequent changesets added to the changegroup contain
+** changes for tables that do not appear in the first changeset, they are
+** appended onto the end of the output changeset, again in the order in
+** which they are first encountered.
+**
+** If an error occurs, an SQLite error code is returned and the output
+** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
+** is returned and the output variables are set to the size of and a 
+** pointer to the output buffer, respectively. In this case it is the
+** responsibility of the caller to eventually free the buffer using a
+** call to sqlite3_free().
+*/
+int sqlite3changegroup_output(
+  sqlite3_changegroup*,
+  int *pnData,                    /* OUT: Size of output buffer in bytes */
+  void **ppData                   /* OUT: Pointer to output buffer */
+);
+
+/*
+** Delete a changegroup object.
+*/
+void sqlite3changegroup_delete(sqlite3_changegroup*);
+
+/*
+** CAPI3REF: Apply A Changeset To A Database
+**
+** Apply a changeset to a database. This function attempts to update the
+** "main" database attached to handle db with the changes found in the
+** changeset passed via the second and third arguments.
+**
+** The fourth argument (xFilter) passed to this function is the "filter
+** callback". If it is not NULL, then for each table affected by at least one
+** change in the changeset, the filter callback is invoked with
+** the table name as the second argument, and a copy of the context pointer
+** passed as the sixth argument to this function as the first. If the "filter
+** callback" returns zero, then no attempt is made to apply any changes to 
+** the table. Otherwise, if the return value is non-zero or the xFilter
+** argument to this function is NULL, all changes related to the table are
+** attempted.
+**
+** For each table that is not excluded by the filter callback, this function 
+** tests that the target database contains a compatible table. A table is 
+** considered compatible if all of the following are true:
+**
+** <ul>
+**   <li> The table has the same name as the name recorded in the 
+**        changeset, and
+**   <li> The table has the same number of columns as recorded in the 
+**        changeset, and
+**   <li> The table has primary key columns in the same position as 
+**        recorded in the changeset.
+** </ul>
+**
+** If there is no compatible table, it is not an error, but none of the
+** changes associated with the table are applied. A warning message is issued
+** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
+** one such warning is issued for each table in the changeset.
+**
+** For each change for which there is a compatible table, an attempt is made 
+** to modify the table contents according to the UPDATE, INSERT or DELETE 
+** change. If a change cannot be applied cleanly, the conflict handler 
+** function passed as the fifth argument to sqlite3changeset_apply() may be 
+** invoked. A description of exactly when the conflict handler is invoked for 
+** each type of change is below.
+**
+** Unlike the xFilter argument, xConflict may not be passed NULL. The results
+** of passing anything other than a valid function pointer as the xConflict
+** argument are undefined.
+**
+** Each time the conflict handler function is invoked, it must return one
+** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 
+** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
+** if the second argument passed to the conflict handler is either
+** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
+** returns an illegal value, any changes already made are rolled back and
+** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 
+** actions are taken by sqlite3changeset_apply() depending on the value
+** returned by each invocation of the conflict-handler function. Refer to
+** the documentation for the three 
+** [SQLITE_CHANGESET_OMIT|available return values] for details.
+**
+** <dl>
+** <dt>DELETE Changes<dd>
+**   For each DELETE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all non-primary key columns also match the values stored in 
+**   the changeset the row is deleted from the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the non-primary key fields contains a value different from the original
+**   row value stored in the changeset, the conflict-handler function is
+**   invoked with [SQLITE_CHANGESET_DATA] as the second argument.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
+**   (which can only happen if a foreign key constraint is violated), the
+**   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
+**   passed as the second argument. This includes the case where the DELETE
+**   operation is attempted because an earlier call to the conflict handler
+**   function returned [SQLITE_CHANGESET_REPLACE].
+**
+** <dt>INSERT Changes<dd>
+**   For each INSERT change, an attempt is made to insert the new row into
+**   the database.
+**
+**   If the attempt to insert the row fails because the database already 
+**   contains a row with the same primary key values, the conflict handler
+**   function is invoked with the second argument set to 
+**   [SQLITE_CHANGESET_CONFLICT].
+**
+**   If the attempt to insert the row fails because of some other constraint
+**   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 
+**   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
+**   This includes the case where the INSERT operation is re-attempted because 
+**   an earlier call to the conflict handler function returned 
+**   [SQLITE_CHANGESET_REPLACE].
+**
+** <dt>UPDATE Changes<dd>
+**   For each UPDATE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all non-primary key columns also match the values stored in 
+**   the changeset the row is updated within the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the non-primary key fields contains a value different from an original
+**   row value stored in the changeset, the conflict-handler function is
+**   invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
+**   UPDATE changes only contain values for non-primary key fields that are
+**   to be modified, only those fields need to match the original values to
+**   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the UPDATE operation is attempted, but SQLite returns 
+**   SQLITE_CONSTRAINT, the conflict-handler function is invoked with 
+**   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
+**   This includes the case where the UPDATE operation is attempted after 
+**   an earlier call to the conflict handler function returned
+**   [SQLITE_CHANGESET_REPLACE].  
+** </dl>
+**
+** It is safe to execute SQL statements, including those that write to the
+** table that the callback related to, from within the xConflict callback.
+** This can be used to further customize the applications conflict
+** resolution strategy.
+**
+** All changes made by this function are enclosed in a savepoint transaction.
+** If any other error (aside from a constraint failure when attempting to
+** write to the target database) occurs, then the savepoint transaction is
+** rolled back, restoring the target database to its original state, and an 
+** SQLite error code returned.
+*/
+int sqlite3changeset_apply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+
+/* 
+** CAPI3REF: Constants Passed To The Conflict Handler
+**
+** Values that may be passed as the second argument to a conflict-handler.
+**
+** <dl>
+** <dt>SQLITE_CHANGESET_DATA<dd>
+**   The conflict handler is invoked with CHANGESET_DATA as the second argument
+**   when processing a DELETE or UPDATE change if a row with the required
+**   PRIMARY KEY fields is present in the database, but one or more other 
+**   (non primary-key) fields modified by the update do not contain the 
+**   expected "before" values.
+** 
+**   The conflicting row, in this case, is the database row with the matching
+**   primary key.
+** 
+** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
+**   The conflict handler is invoked with CHANGESET_NOTFOUND as the second
+**   argument when processing a DELETE or UPDATE change if a row with the
+**   required PRIMARY KEY fields is not present in the database.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+** 
+** <dt>SQLITE_CHANGESET_CONFLICT<dd>
+**   CHANGESET_CONFLICT is passed as the second argument to the conflict
+**   handler while processing an INSERT change if the operation would result 
+**   in duplicate primary key values.
+** 
+**   The conflicting row in this case is the database row with the matching
+**   primary key.
+**
+** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
+**   If foreign key handling is enabled, and applying a changeset leaves the
+**   database in a state containing foreign key violations, the conflict 
+**   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
+**   exactly once before the changeset is committed. If the conflict handler
+**   returns CHANGESET_OMIT, the changes, including those that caused the
+**   foreign key constraint violation, are committed. Or, if it returns
+**   CHANGESET_ABORT, the changeset is rolled back.
+**
+**   No current or conflicting row information is provided. The only function
+**   it is possible to call on the supplied sqlite3_changeset_iter handle
+**   is sqlite3changeset_fk_conflicts().
+** 
+** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
+**   If any other constraint violation occurs while applying a change (i.e. 
+**   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 
+**   invoked with CHANGESET_CONSTRAINT as the second argument.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+**
+** </dl>
+*/
+#define SQLITE_CHANGESET_DATA        1
+#define SQLITE_CHANGESET_NOTFOUND    2
+#define SQLITE_CHANGESET_CONFLICT    3
+#define SQLITE_CHANGESET_CONSTRAINT  4
+#define SQLITE_CHANGESET_FOREIGN_KEY 5
+
+/* 
+** CAPI3REF: Constants Returned By The Conflict Handler
+**
+** A conflict handler callback must return one of the following three values.
+**
+** <dl>
+** <dt>SQLITE_CHANGESET_OMIT<dd>
+**   If a conflict handler returns this value no special action is taken. The
+**   change that caused the conflict is not applied. The session module 
+**   continues to the next change in the changeset.
+**
+** <dt>SQLITE_CHANGESET_REPLACE<dd>
+**   This value may only be returned if the second argument to the conflict
+**   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
+**   is not the case, any changes applied so far are rolled back and the 
+**   call to sqlite3changeset_apply() returns SQLITE_MISUSE.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
+**   handler, then the conflicting row is either updated or deleted, depending
+**   on the type of change.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
+**   handler, then the conflicting row is removed from the database and a
+**   second attempt to apply the change is made. If this second attempt fails,
+**   the original row is restored to the database before continuing.
+**
+** <dt>SQLITE_CHANGESET_ABORT<dd>
+**   If this value is returned, any changes applied so far are rolled back 
+**   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
+** </dl>
+*/
+#define SQLITE_CHANGESET_OMIT       0
+#define SQLITE_CHANGESET_REPLACE    1
+#define SQLITE_CHANGESET_ABORT      2
+
+/*
+** CAPI3REF: Streaming Versions of API functions.
+**
+** The six streaming API xxx_strm() functions serve similar purposes to the 
+** corresponding non-streaming API functions:
+**
+** <table border=1 style="margin-left:8ex;margin-right:8ex">
+**   <tr><th>Streaming function<th>Non-streaming equivalent</th>
+**   <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 
+**   <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 
+**   <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 
+**   <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 
+**   <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 
+**   <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 
+** </table>
+**
+** Non-streaming functions that accept changesets (or patchsets) as input
+** require that the entire changeset be stored in a single buffer in memory. 
+** Similarly, those that return a changeset or patchset do so by returning 
+** a pointer to a single large buffer allocated using sqlite3_malloc(). 
+** Normally this is convenient. However, if an application running in a 
+** low-memory environment is required to handle very large changesets, the
+** large contiguous memory allocations required can become onerous.
+**
+** In order to avoid this problem, instead of a single large buffer, input
+** is passed to a streaming API functions by way of a callback function that
+** the sessions module invokes to incrementally request input data as it is
+** required. In all cases, a pair of API function parameters such as
+**
+**  <pre>
+**  &nbsp;     int nChangeset,
+**  &nbsp;     void *pChangeset,
+**  </pre>
+**
+** Is replaced by:
+**
+**  <pre>
+**  &nbsp;     int (*xInput)(void *pIn, void *pData, int *pnData),
+**  &nbsp;     void *pIn,
+**  </pre>
+**
+** Each time the xInput callback is invoked by the sessions module, the first
+** argument passed is a copy of the supplied pIn context pointer. The second 
+** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 
+** error occurs the xInput method should copy up to (*pnData) bytes of data 
+** into the buffer and set (*pnData) to the actual number of bytes copied 
+** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 
+** should be set to zero to indicate this. Or, if an error occurs, an SQLite 
+** error code should be returned. In all cases, if an xInput callback returns
+** an error, all processing is abandoned and the streaming API function
+** returns a copy of the error code to the caller.
+**
+** In the case of sqlite3changeset_start_strm(), the xInput callback may be
+** invoked by the sessions module at any point during the lifetime of the
+** iterator. If such an xInput callback returns an error, the iterator enters
+** an error state, whereby all subsequent calls to iterator functions 
+** immediately fail with the same error code as returned by xInput.
+**
+** Similarly, streaming API functions that return changesets (or patchsets)
+** return them in chunks by way of a callback function instead of via a
+** pointer to a single large buffer. In this case, a pair of parameters such
+** as:
+**
+**  <pre>
+**  &nbsp;     int *pnChangeset,
+**  &nbsp;     void **ppChangeset,
+**  </pre>
+**
+** Is replaced by:
+**
+**  <pre>
+**  &nbsp;     int (*xOutput)(void *pOut, const void *pData, int nData),
+**  &nbsp;     void *pOut
+**  </pre>
+**
+** The xOutput callback is invoked zero or more times to return data to
+** the application. The first parameter passed to each call is a copy of the
+** pOut pointer supplied by the application. The second parameter, pData,
+** points to a buffer nData bytes in size containing the chunk of output
+** data being returned. If the xOutput callback successfully processes the
+** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
+** it should return some other SQLite error code. In this case processing
+** is immediately abandoned and the streaming API function returns a copy
+** of the xOutput error code to the application.
+**
+** The sessions module never invokes an xOutput callback with the third 
+** parameter set to a value less than or equal to zero. Other than this,
+** no guarantees are made as to the size of the chunks of data returned.
+*/
+int sqlite3changeset_apply_strm(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
+  void *pIn,                                          /* First arg for xInput */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+int sqlite3changeset_concat_strm(
+  int (*xInputA)(void *pIn, void *pData, int *pnData),
+  void *pInA,
+  int (*xInputB)(void *pIn, void *pData, int *pnData),
+  void *pInB,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+int sqlite3changeset_invert_strm(
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+int sqlite3changeset_start_strm(
+  sqlite3_changeset_iter **pp,
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn
+);
+int sqlite3session_changeset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+int sqlite3session_patchset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+);
+int sqlite3changegroup_add_strm(sqlite3_changegroup*, 
+    int (*xInput)(void *pIn, void *pData, int *pnData),
+    void *pIn
+);
+int sqlite3changegroup_output_strm(sqlite3_changegroup*,
+    int (*xOutput)(void *pOut, const void *pData, int nData), 
+    void *pOut
+);
+
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#if 0
+}
+#endif
+
+#endif  /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
+
+/******** End of sqlite3session.h *********/
+/******** Begin file fts5.h *********/
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Interfaces to extend FTS5. Using the interfaces defined in this file, 
+** FTS5 may be extended with:
+**
+**     * custom tokenizers, and
+**     * custom auxiliary functions.
+*/
+
+
+#ifndef _FTS5_H
+#define _FTS5_H
+
+
+#if 0
+extern "C" {
+#endif
+
+/*************************************************************************
+** CUSTOM AUXILIARY FUNCTIONS
+**
+** Virtual table implementations may overload SQL functions by implementing
+** the sqlite3_module.xFindFunction() method.
+*/
+
+typedef struct Fts5ExtensionApi Fts5ExtensionApi;
+typedef struct Fts5Context Fts5Context;
+typedef struct Fts5PhraseIter Fts5PhraseIter;
+
+typedef void (*fts5_extension_function)(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+);
+
+struct Fts5PhraseIter {
+  const unsigned char *a;
+  const unsigned char *b;
+};
+
+/*
+** EXTENSION API FUNCTIONS
+**
+** xUserData(pFts):
+**   Return a copy of the context pointer the extension function was 
+**   registered with.
+**
+** xColumnTotalSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the FTS5 table. Or, if iCol is
+**   non-negative but less than the number of columns in the table, return
+**   the total number of tokens in column iCol, considering all rows in 
+**   the FTS5 table.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+** xColumnCount(pFts):
+**   Return the number of columns in the table.
+**
+** xColumnSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the current row. Or, if iCol is
+**   non-negative but less than the number of columns in the table, set
+**   *pnToken to the number of tokens in column iCol of the current row.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+**   This function may be quite inefficient if used with an FTS5 table
+**   created with the "columnsize=0" option.
+**
+** xColumnText:
+**   This function attempts to retrieve the text of column iCol of the
+**   current document. If successful, (*pz) is set to point to a buffer
+**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
+**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
+**   if an error occurs, an SQLite error code is returned and the final values
+**   of (*pz) and (*pn) are undefined.
+**
+** xPhraseCount:
+**   Returns the number of phrases in the current query expression.
+**
+** xPhraseSize:
+**   Returns the number of tokens in phrase iPhrase of the query. Phrases
+**   are numbered starting from zero.
+**
+** xInstCount:
+**   Set *pnInst to the total number of occurrences of all phrases within
+**   the query within the current row. Return SQLITE_OK if successful, or
+**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always returns 0.
+**
+** xInst:
+**   Query for the details of phrase match iIdx within the current row.
+**   Phrase matches are numbered starting from zero, so the iIdx argument
+**   should be greater than or equal to zero and smaller than the value
+**   output by xInstCount().
+**
+**   Usually, output parameter *piPhrase is set to the phrase number, *piCol
+**   to the column in which it occurs and *piOff the token offset of the
+**   first token of the phrase. The exception is if the table was created
+**   with the offsets=0 option specified. In this case *piOff is always
+**   set to -1.
+**
+**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
+**   if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. 
+**
+** xRowid:
+**   Returns the rowid of the current row.
+**
+** xTokenize:
+**   Tokenize text using the tokenizer belonging to the FTS5 table.
+**
+** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
+**   This API function is used to query the FTS table for phrase iPhrase
+**   of the current query. Specifically, a query equivalent to:
+**
+**       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
+**
+**   with $p set to a phrase equivalent to the phrase iPhrase of the
+**   current query is executed. Any column filter that applies to
+**   phrase iPhrase of the current query is included in $p. For each 
+**   row visited, the callback function passed as the fourth argument 
+**   is invoked. The context and API objects passed to the callback 
+**   function may be used to access the properties of each matched row.
+**   Invoking Api.xUserData() returns a copy of the pointer passed as 
+**   the third argument to pUserData.
+**
+**   If the callback function returns any value other than SQLITE_OK, the
+**   query is abandoned and the xQueryPhrase function returns immediately.
+**   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
+**   Otherwise, the error code is propagated upwards.
+**
+**   If the query runs to completion without incident, SQLITE_OK is returned.
+**   Or, if some error occurs before the query completes or is aborted by
+**   the callback, an SQLite error code is returned.
+**
+**
+** xSetAuxdata(pFts5, pAux, xDelete)
+**
+**   Save the pointer passed as the second argument as the extension functions 
+**   "auxiliary data". The pointer may then be retrieved by the current or any
+**   future invocation of the same fts5 extension function made as part of
+**   of the same MATCH query using the xGetAuxdata() API.
+**
+**   Each extension function is allocated a single auxiliary data slot for
+**   each FTS query (MATCH expression). If the extension function is invoked 
+**   more than once for a single FTS query, then all invocations share a 
+**   single auxiliary data context.
+**
+**   If there is already an auxiliary data pointer when this function is
+**   invoked, then it is replaced by the new pointer. If an xDelete callback
+**   was specified along with the original pointer, it is invoked at this
+**   point.
+**
+**   The xDelete callback, if one is specified, is also invoked on the
+**   auxiliary data pointer after the FTS5 query has finished.
+**
+**   If an error (e.g. an OOM condition) occurs within this function, an
+**   the auxiliary data is set to NULL and an error code returned. If the
+**   xDelete parameter was not NULL, it is invoked on the auxiliary data
+**   pointer before returning.
+**
+**
+** xGetAuxdata(pFts5, bClear)
+**
+**   Returns the current auxiliary data pointer for the fts5 extension 
+**   function. See the xSetAuxdata() method for details.
+**
+**   If the bClear argument is non-zero, then the auxiliary data is cleared
+**   (set to NULL) before this function returns. In this case the xDelete,
+**   if any, is not invoked.
+**
+**
+** xRowCount(pFts5, pnRow)
+**
+**   This function is used to retrieve the total number of rows in the table.
+**   In other words, the same value that would be returned by:
+**
+**        SELECT count(*) FROM ftstable;
+**
+** xPhraseFirst()
+**   This function is used, along with type Fts5PhraseIter and the xPhraseNext
+**   method, to iterate through all instances of a single query phrase within
+**   the current row. This is the same information as is accessible via the
+**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
+**   to use, this API may be faster under some circumstances. To iterate 
+**   through instances of phrase iPhrase, use the following code:
+**
+**       Fts5PhraseIter iter;
+**       int iCol, iOff;
+**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
+**           iCol>=0;
+**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
+**       ){
+**         // An instance of phrase iPhrase at offset iOff of column iCol
+**       }
+**
+**   The Fts5PhraseIter structure is defined above. Applications should not
+**   modify this structure directly - it should only be used as shown above
+**   with the xPhraseFirst() and xPhraseNext() API methods (and by
+**   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always iterates
+**   through an empty set (all calls to xPhraseFirst() set iCol to -1).
+**
+** xPhraseNext()
+**   See xPhraseFirst above.
+**
+** xPhraseFirstColumn()
+**   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
+**   and xPhraseNext() APIs described above. The difference is that instead
+**   of iterating through all instances of a phrase in the current row, these
+**   APIs are used to iterate through the set of columns in the current row
+**   that contain one or more instances of a specified phrase. For example:
+**
+**       Fts5PhraseIter iter;
+**       int iCol;
+**       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
+**           iCol>=0;
+**           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
+**       ){
+**         // Column iCol contains at least one instance of phrase iPhrase
+**       }
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" option. If the FTS5 table is created with either 
+**   "detail=none" "content=" option (i.e. if it is a contentless table), 
+**   then this API always iterates through an empty set (all calls to 
+**   xPhraseFirstColumn() set iCol to -1).
+**
+**   The information accessed using this API and its companion
+**   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
+**   (or xInst/xInstCount). The chief advantage of this API is that it is
+**   significantly more efficient than those alternatives when used with
+**   "detail=column" tables.  
+**
+** xPhraseNextColumn()
+**   See xPhraseFirstColumn above.
+*/
+struct Fts5ExtensionApi {
+  int iVersion;                   /* Currently always set to 3 */
+
+  void *(*xUserData)(Fts5Context*);
+
+  int (*xColumnCount)(Fts5Context*);
+  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
+  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
+
+  int (*xTokenize)(Fts5Context*, 
+    const char *pText, int nText, /* Text to tokenize */
+    void *pCtx,                   /* Context passed to xToken() */
+    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
+  );
+
+  int (*xPhraseCount)(Fts5Context*);
+  int (*xPhraseSize)(Fts5Context*, int iPhrase);
+
+  int (*xInstCount)(Fts5Context*, int *pnInst);
+  int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
+
+  sqlite3_int64 (*xRowid)(Fts5Context*);
+  int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
+  int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
+
+  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
+    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
+  );
+  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
+  void *(*xGetAuxdata)(Fts5Context*, int bClear);
+
+  int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
+  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
+
+  int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
+  void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
+};
+
+/* 
+** CUSTOM AUXILIARY FUNCTIONS
+*************************************************************************/
+
+/*************************************************************************
+** CUSTOM TOKENIZERS
+**
+** Applications may also register custom tokenizer types. A tokenizer 
+** is registered by providing fts5 with a populated instance of the 
+** following structure. All structure methods must be defined, setting
+** any member of the fts5_tokenizer struct to NULL leads to undefined
+** behaviour. The structure methods are expected to function as follows:
+**
+** xCreate:
+**   This function is used to allocate and initialize a tokenizer instance.
+**   A tokenizer instance is required to actually tokenize text.
+**
+**   The first argument passed to this function is a copy of the (void*)
+**   pointer provided by the application when the fts5_tokenizer object
+**   was registered with FTS5 (the third argument to xCreateTokenizer()). 
+**   The second and third arguments are an array of nul-terminated strings
+**   containing the tokenizer arguments, if any, specified following the
+**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
+**   to create the FTS5 table.
+**
+**   The final argument is an output variable. If successful, (*ppOut) 
+**   should be set to point to the new tokenizer handle and SQLITE_OK
+**   returned. If an error occurs, some value other than SQLITE_OK should
+**   be returned. In this case, fts5 assumes that the final value of *ppOut 
+**   is undefined.
+**
+** xDelete:
+**   This function is invoked to delete a tokenizer handle previously
+**   allocated using xCreate(). Fts5 guarantees that this function will
+**   be invoked exactly once for each successful call to xCreate().
+**
+** xTokenize:
+**   This function is expected to tokenize the nText byte string indicated 
+**   by argument pText. pText may or may not be nul-terminated. The first
+**   argument passed to this function is a pointer to an Fts5Tokenizer object
+**   returned by an earlier call to xCreate().
+**
+**   The second argument indicates the reason that FTS5 is requesting
+**   tokenization of the supplied text. This is always one of the following
+**   four values:
+**
+**   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
+**            or removed from the FTS table. The tokenizer is being invoked to
+**            determine the set of tokens to add to (or delete from) the
+**            FTS index.
+**
+**       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 
+**            against the FTS index. The tokenizer is being called to tokenize 
+**            a bareword or quoted string specified as part of the query.
+**
+**       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
+**            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
+**            followed by a "*" character, indicating that the last token
+**            returned by the tokenizer will be treated as a token prefix.
+**
+**       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 
+**            satisfy an fts5_api.xTokenize() request made by an auxiliary
+**            function. Or an fts5_api.xColumnSize() request made by the same
+**            on a columnsize=0 database.  
+**   </ul>
+**
+**   For each token in the input string, the supplied callback xToken() must
+**   be invoked. The first argument to it should be a copy of the pointer
+**   passed as the second argument to xTokenize(). The third and fourth
+**   arguments are a pointer to a buffer containing the token text, and the
+**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
+**   of the first byte of and first byte immediately following the text from
+**   which the token is derived within the input.
+**
+**   The second argument passed to the xToken() callback ("tflags") should
+**   normally be set to 0. The exception is if the tokenizer supports 
+**   synonyms. In this case see the discussion below for details.
+**
+**   FTS5 assumes the xToken() callback is invoked for each token in the 
+**   order that they occur within the input text.
+**
+**   If an xToken() callback returns any value other than SQLITE_OK, then
+**   the tokenization should be abandoned and the xTokenize() method should
+**   immediately return a copy of the xToken() return value. Or, if the
+**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
+**   if an error occurs with the xTokenize() implementation itself, it
+**   may abandon the tokenization and return any error code other than
+**   SQLITE_OK or SQLITE_DONE.
+**
+** SYNONYM SUPPORT
+**
+**   Custom tokenizers may also support synonyms. Consider a case in which a
+**   user wishes to query for a phrase such as "first place". Using the 
+**   built-in tokenizers, the FTS5 query 'first + place' will match instances
+**   of "first place" within the document set, but not alternative forms
+**   such as "1st place". In some applications, it would be better to match
+**   all instances of "first place" or "1st place" regardless of which form
+**   the user specified in the MATCH query text.
+**
+**   There are several ways to approach this in FTS5:
+**
+**   <ol><li> By mapping all synonyms to a single token. In this case, the 
+**            In the above example, this means that the tokenizer returns the
+**            same token for inputs "first" and "1st". Say that token is in
+**            fact "first", so that when the user inserts the document "I won
+**            1st place" entries are added to the index for tokens "i", "won",
+**            "first" and "place". If the user then queries for '1st + place',
+**            the tokenizer substitutes "first" for "1st" and the query works
+**            as expected.
+**
+**       <li> By adding multiple synonyms for a single term to the FTS index.
+**            In this case, when tokenizing query text, the tokenizer may 
+**            provide multiple synonyms for a single term within the document.
+**            FTS5 then queries the index for each synonym individually. For
+**            example, faced with the query:
+**
+**   <codeblock>
+**     ... MATCH 'first place'</codeblock>
+**
+**            the tokenizer offers both "1st" and "first" as synonyms for the
+**            first token in the MATCH query and FTS5 effectively runs a query 
+**            similar to:
+**
+**   <codeblock>
+**     ... MATCH '(first OR 1st) place'</codeblock>
+**
+**            except that, for the purposes of auxiliary functions, the query
+**            still appears to contain just two phrases - "(first OR 1st)" 
+**            being treated as a single phrase.
+**
+**       <li> By adding multiple synonyms for a single term to the FTS index.
+**            Using this method, when tokenizing document text, the tokenizer
+**            provides multiple synonyms for each token. So that when a 
+**            document such as "I won first place" is tokenized, entries are
+**            added to the FTS index for "i", "won", "first", "1st" and
+**            "place".
+**
+**            This way, even if the tokenizer does not provide synonyms
+**            when tokenizing query text (it should not - to do would be
+**            inefficient), it doesn't matter if the user queries for 
+**            'first + place' or '1st + place', as there are entires in the
+**            FTS index corresponding to both forms of the first token.
+**   </ol>
+**
+**   Whether it is parsing document or query text, any call to xToken that
+**   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
+**   is considered to supply a synonym for the previous token. For example,
+**   when parsing the document "I won first place", a tokenizer that supports
+**   synonyms would call xToken() 5 times, as follows:
+**
+**   <codeblock>
+**       xToken(pCtx, 0, "i",                      1,  0,  1);
+**       xToken(pCtx, 0, "won",                    3,  2,  5);
+**       xToken(pCtx, 0, "first",                  5,  6, 11);
+**       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
+**       xToken(pCtx, 0, "place",                  5, 12, 17);
+**</codeblock>
+**
+**   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
+**   xToken() is called. Multiple synonyms may be specified for a single token
+**   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 
+**   There is no limit to the number of synonyms that may be provided for a
+**   single token.
+**
+**   In many cases, method (1) above is the best approach. It does not add 
+**   extra data to the FTS index or require FTS5 to query for multiple terms,
+**   so it is efficient in terms of disk space and query speed. However, it
+**   does not support prefix queries very well. If, as suggested above, the
+**   token "first" is subsituted for "1st" by the tokenizer, then the query:
+**
+**   <codeblock>
+**     ... MATCH '1s*'</codeblock>
+**
+**   will not match documents that contain the token "1st" (as the tokenizer
+**   will probably not map "1s" to any prefix of "first").
+**
+**   For full prefix support, method (3) may be preferred. In this case, 
+**   because the index contains entries for both "first" and "1st", prefix
+**   queries such as 'fi*' or '1s*' will match correctly. However, because
+**   extra entries are added to the FTS index, this method uses more space
+**   within the database.
+**
+**   Method (2) offers a midpoint between (1) and (3). Using this method,
+**   a query such as '1s*' will match documents that contain the literal 
+**   token "1st", but not "first" (assuming the tokenizer is not able to
+**   provide synonyms for prefixes). However, a non-prefix query like '1st'
+**   will match against "1st" and "first". This method does not require
+**   extra disk space, as no extra entries are added to the FTS index. 
+**   On the other hand, it may require more CPU cycles to run MATCH queries,
+**   as separate queries of the FTS index are required for each synonym.
+**
+**   When using methods (2) or (3), it is important that the tokenizer only
+**   provide synonyms when tokenizing document text (method (2)) or query
+**   text (method (3)), not both. Doing so will not cause any errors, but is
+**   inefficient.
+*/
+typedef struct Fts5Tokenizer Fts5Tokenizer;
+typedef struct fts5_tokenizer fts5_tokenizer;
+struct fts5_tokenizer {
+  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
+  void (*xDelete)(Fts5Tokenizer*);
+  int (*xTokenize)(Fts5Tokenizer*, 
+      void *pCtx,
+      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
+      const char *pText, int nText, 
+      int (*xToken)(
+        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
+        int tflags,         /* Mask of FTS5_TOKEN_* flags */
+        const char *pToken, /* Pointer to buffer containing token */
+        int nToken,         /* Size of token in bytes */
+        int iStart,         /* Byte offset of token within input text */
+        int iEnd            /* Byte offset of end of token within input text */
+      )
+  );
+};
+
+/* Flags that may be passed as the third argument to xTokenize() */
+#define FTS5_TOKENIZE_QUERY     0x0001
+#define FTS5_TOKENIZE_PREFIX    0x0002
+#define FTS5_TOKENIZE_DOCUMENT  0x0004
+#define FTS5_TOKENIZE_AUX       0x0008
+
+/* Flags that may be passed by the tokenizer implementation back to FTS5
+** as the third argument to the supplied xToken callback. */
+#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
+
+/*
+** END OF CUSTOM TOKENIZERS
+*************************************************************************/
+
+/*************************************************************************
+** FTS5 EXTENSION REGISTRATION API
+*/
+typedef struct fts5_api fts5_api;
+struct fts5_api {
+  int iVersion;                   /* Currently always set to 2 */
+
+  /* Create a new tokenizer */
+  int (*xCreateTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_tokenizer *pTokenizer,
+    void (*xDestroy)(void*)
+  );
+
+  /* Find an existing tokenizer */
+  int (*xFindTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void **ppContext,
+    fts5_tokenizer *pTokenizer
+  );
+
+  /* Create a new auxiliary function */
+  int (*xCreateFunction)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_extension_function xFunction,
+    void (*xDestroy)(void*)
+  );
+};
+
+/*
+** END OF REGISTRATION API
+*************************************************************************/
+
+#if 0
+}  /* end of the 'extern "C"' block */
+#endif
+
+#endif /* _FTS5_H */
+
+/******** End of fts5.h *********/
 
 /************** End of sqlite3.h *********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
+
+/*
+** Include the configuration header output by 'configure' if we're using the
+** autoconf-based build
+*/
+#ifdef _HAVE_SQLITE_CONFIG_H
+#include "config.h"
+#endif
+
+/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
+/************** Begin file sqliteLimit.h *************************************/
+/*
+** 2007 May 7
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** 
+** This file defines various limits of what SQLite can process.
+*/
+
+/*
+** The maximum length of a TEXT or BLOB in bytes.   This also
+** limits the size of a row in a table or index.
+**
+** The hard limit is the ability of a 32-bit signed integer
+** to count the size: 2^31-1 or 2147483647.
+*/
+#ifndef SQLITE_MAX_LENGTH
+# define SQLITE_MAX_LENGTH 1000000000
+#endif
+
+/*
+** This is the maximum number of
+**
+**    * Columns in a table
+**    * Columns in an index
+**    * Columns in a view
+**    * Terms in the SET clause of an UPDATE statement
+**    * Terms in the result set of a SELECT statement
+**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
+**    * Terms in the VALUES clause of an INSERT statement
+**
+** The hard upper limit here is 32676.  Most database people will
+** tell you that in a well-normalized database, you usually should
+** not have more than a dozen or so columns in any table.  And if
+** that is the case, there is no point in having more than a few
+** dozen values in any of the other situations described above.
+*/
+#ifndef SQLITE_MAX_COLUMN
+# define SQLITE_MAX_COLUMN 2000
+#endif
+
+/*
+** The maximum length of a single SQL statement in bytes.
+**
+** It used to be the case that setting this value to zero would
+** turn the limit off.  That is no longer true.  It is not possible
+** to turn this limit off.
+*/
+#ifndef SQLITE_MAX_SQL_LENGTH
+# define SQLITE_MAX_SQL_LENGTH 1000000000
+#endif
+
+/*
+** The maximum depth of an expression tree. This is limited to 
+** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 
+** want to place more severe limits on the complexity of an 
+** expression.
+**
+** A value of 0 used to mean that the limit was not enforced.
+** But that is no longer true.  The limit is now strictly enforced
+** at all times.
+*/
+#ifndef SQLITE_MAX_EXPR_DEPTH
+# define SQLITE_MAX_EXPR_DEPTH 1000
+#endif
+
+/*
+** The maximum number of terms in a compound SELECT statement.
+** The code generator for compound SELECT statements does one
+** level of recursion for each term.  A stack overflow can result
+** if the number of terms is too large.  In practice, most SQL
+** never has more than 3 or 4 terms.  Use a value of 0 to disable
+** any limit on the number of terms in a compount SELECT.
+*/
+#ifndef SQLITE_MAX_COMPOUND_SELECT
+# define SQLITE_MAX_COMPOUND_SELECT 500
+#endif
+
+/*
+** The maximum number of opcodes in a VDBE program.
+** Not currently enforced.
+*/
+#ifndef SQLITE_MAX_VDBE_OP
+# define SQLITE_MAX_VDBE_OP 25000
+#endif
+
+/*
+** The maximum number of arguments to an SQL function.
+*/
+#ifndef SQLITE_MAX_FUNCTION_ARG
+# define SQLITE_MAX_FUNCTION_ARG 127
+#endif
+
+/*
+** The suggested maximum number of in-memory pages to use for
+** the main database table and for temporary tables.
+**
+** IMPLEMENTATION-OF: R-30185-15359 The default suggested cache size is -2000,
+** which means the cache size is limited to 2048000 bytes of memory.
+** IMPLEMENTATION-OF: R-48205-43578 The default suggested cache size can be
+** altered using the SQLITE_DEFAULT_CACHE_SIZE compile-time options.
+*/
+#ifndef SQLITE_DEFAULT_CACHE_SIZE
+# define SQLITE_DEFAULT_CACHE_SIZE  -2000
+#endif
+
+/*
+** The default number of frames to accumulate in the log file before
+** checkpointing the database in WAL mode.
+*/
+#ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT
+# define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT  1000
+#endif
+
+/*
+** The maximum number of attached databases.  This must be between 0
+** and 125.  The upper bound of 125 is because the attached databases are
+** counted using a signed 8-bit integer which has a maximum value of 127
+** and we have to allow 2 extra counts for the "main" and "temp" databases.
+*/
+#ifndef SQLITE_MAX_ATTACHED
+# define SQLITE_MAX_ATTACHED 10
+#endif
+
+
+/*
+** The maximum value of a ?nnn wildcard that the parser will accept.
+*/
+#ifndef SQLITE_MAX_VARIABLE_NUMBER
+# define SQLITE_MAX_VARIABLE_NUMBER 999
+#endif
+
+/* Maximum page size.  The upper bound on this value is 65536.  This a limit
+** imposed by the use of 16-bit offsets within each page.
+**
+** Earlier versions of SQLite allowed the user to change this value at
+** compile time. This is no longer permitted, on the grounds that it creates
+** a library that is technically incompatible with an SQLite library 
+** compiled with a different limit. If a process operating on a database 
+** with a page-size of 65536 bytes crashes, then an instance of SQLite 
+** compiled with the default page-size limit will not be able to rollback 
+** the aborted transaction. This could lead to database corruption.
+*/
+#ifdef SQLITE_MAX_PAGE_SIZE
+# undef SQLITE_MAX_PAGE_SIZE
+#endif
+#define SQLITE_MAX_PAGE_SIZE 65536
+
+
+/*
+** The default size of a database page.
+*/
+#ifndef SQLITE_DEFAULT_PAGE_SIZE
+# define SQLITE_DEFAULT_PAGE_SIZE 4096
+#endif
+#if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
+# undef SQLITE_DEFAULT_PAGE_SIZE
+# define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
+#endif
+
+/*
+** Ordinarily, if no value is explicitly provided, SQLite creates databases
+** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
+** device characteristics (sector-size and atomic write() support),
+** SQLite may choose a larger value. This constant is the maximum value
+** SQLite will choose on its own.
+*/
+#ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE
+# define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192
+#endif
+#if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE
+# undef SQLITE_MAX_DEFAULT_PAGE_SIZE
+# define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE
+#endif
+
+
+/*
+** Maximum number of pages in one database file.
+**
+** This is really just the default value for the max_page_count pragma.
+** This value can be lowered (or raised) at run-time using that the
+** max_page_count macro.
+*/
+#ifndef SQLITE_MAX_PAGE_COUNT
+# define SQLITE_MAX_PAGE_COUNT 1073741823
+#endif
+
+/*
+** Maximum length (in bytes) of the pattern in a LIKE or GLOB
+** operator.
+*/
+#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
+# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
+#endif
+
+/*
+** Maximum depth of recursion for triggers.
+**
+** A value of 1 means that a trigger program will not be able to itself
+** fire any triggers. A value of 0 means that no trigger programs at all 
+** may be executed.
+*/
+#ifndef SQLITE_MAX_TRIGGER_DEPTH
+# define SQLITE_MAX_TRIGGER_DEPTH 1000
+#endif
+
+/************** End of sqliteLimit.h *****************************************/
+/************** Continuing where we left off in sqliteInt.h ******************/
+
+/* Disable nuisance warnings on Borland compilers */
+#if defined(__BORLANDC__)
+#pragma warn -rch /* unreachable code */
+#pragma warn -ccc /* Condition is always true or false */
+#pragma warn -aus /* Assigned value is never used */
+#pragma warn -csu /* Comparing signed and unsigned */
+#pragma warn -spa /* Suspicious pointer arithmetic */
+#endif
+
+/*
+** Include standard header files as necessary
+*/
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
+/*
+** The following macros are used to cast pointers to integers and
+** integers to pointers.  The way you do this varies from one compiler
+** to the next, so we have developed the following set of #if statements
+** to generate appropriate macros for a wide range of compilers.
+**
+** The correct "ANSI" way to do this is to use the intptr_t type.
+** Unfortunately, that typedef is not available on all compilers, or
+** if it is available, it requires an #include of specific headers
+** that vary from one machine to the next.
+**
+** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
+** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
+** So we have to define the macros in different ways depending on the
+** compiler.
+*/
+#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
+# define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
+# define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
+#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
+# define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
+# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
+#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
+# define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
+# define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
+#else                          /* Generates a warning - but it always works */
+# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
+# define SQLITE_PTR_TO_INT(X)  ((int)(X))
+#endif
+
+/*
+** A macro to hint to the compiler that a function should not be
+** inlined.
+*/
+#if defined(__GNUC__)
+#  define SQLITE_NOINLINE  __attribute__((noinline))
+#elif defined(_MSC_VER) && _MSC_VER>=1310
+#  define SQLITE_NOINLINE  __declspec(noinline)
+#else
+#  define SQLITE_NOINLINE
+#endif
+
+/*
+** Make sure that the compiler intrinsics we desire are enabled when
+** compiling with an appropriate version of MSVC unless prevented by
+** the SQLITE_DISABLE_INTRINSIC define.
+*/
+#if !defined(SQLITE_DISABLE_INTRINSIC)
+#  if defined(_MSC_VER) && _MSC_VER>=1400
+#    if !defined(_WIN32_WCE)
+#      include <intrin.h>
+#      pragma intrinsic(_byteswap_ushort)
+#      pragma intrinsic(_byteswap_ulong)
+#      pragma intrinsic(_ReadWriteBarrier)
+#    else
+#      include <cmnintrin.h>
+#    endif
+#  endif
+#endif
+
+/*
+** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
+** 0 means mutexes are permanently disable and the library is never
+** threadsafe.  1 means the library is serialized which is the highest
+** level of threadsafety.  2 means the library is multithreaded - multiple
+** threads can use SQLite as long as no two threads try to use the same
+** database connection at the same time.
+**
+** Older versions of SQLite used an optional THREADSAFE macro.
+** We support that for legacy.
+*/
+#if !defined(SQLITE_THREADSAFE)
+# if defined(THREADSAFE)
+#   define SQLITE_THREADSAFE THREADSAFE
+# else
+#   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
+# endif
+#endif
+
+/*
+** Powersafe overwrite is on by default.  But can be turned off using
+** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
+*/
+#ifndef SQLITE_POWERSAFE_OVERWRITE
+# define SQLITE_POWERSAFE_OVERWRITE 1
+#endif
+
+/*
+** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by
+** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in
+** which case memory allocation statistics are disabled by default.
+*/
+#if !defined(SQLITE_DEFAULT_MEMSTATUS)
+# define SQLITE_DEFAULT_MEMSTATUS 1
+#endif
+
+/*
+** Exactly one of the following macros must be defined in order to
+** specify which memory allocation subsystem to use.
+**
+**     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
+**     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
+**     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails
+**     SQLITE_MEMDEBUG               // Debugging version of system malloc()
+**
+** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
+** assert() macro is enabled, each call into the Win32 native heap subsystem
+** will cause HeapValidate to be called.  If heap validation should fail, an
+** assertion will be triggered.
+**
+** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
+** the default.
+*/
+#if defined(SQLITE_SYSTEM_MALLOC) \
+  + defined(SQLITE_WIN32_MALLOC) \
+  + defined(SQLITE_ZERO_MALLOC) \
+  + defined(SQLITE_MEMDEBUG)>1
+# error "Two or more of the following compile-time configuration options\
+ are defined but at most one is allowed:\
+ SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\
+ SQLITE_ZERO_MALLOC"
+#endif
+#if defined(SQLITE_SYSTEM_MALLOC) \
+  + defined(SQLITE_WIN32_MALLOC) \
+  + defined(SQLITE_ZERO_MALLOC) \
+  + defined(SQLITE_MEMDEBUG)==0
+# define SQLITE_SYSTEM_MALLOC 1
+#endif
+
+/*
+** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
+** sizes of memory allocations below this value where possible.
+*/
+#if !defined(SQLITE_MALLOC_SOFT_LIMIT)
+# define SQLITE_MALLOC_SOFT_LIMIT 1024
+#endif
+
+/*
+** We need to define _XOPEN_SOURCE as follows in order to enable
+** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
+** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
+** it.
+*/
+#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
+#  define _XOPEN_SOURCE 600
+#endif
+
+/*
+** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
+** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
+** make it true by defining or undefining NDEBUG.
+**
+** Setting NDEBUG makes the code smaller and faster by disabling the
+** assert() statements in the code.  So we want the default action
+** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
+** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
+** feature.
+*/
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
+# define NDEBUG 1
+#endif
+#if defined(NDEBUG) && defined(SQLITE_DEBUG)
+# undef NDEBUG
+#endif
+
+/*
+** Enable SQLITE_ENABLE_EXPLAIN_COMMENTS if SQLITE_DEBUG is turned on.
+*/
+#if !defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) && defined(SQLITE_DEBUG)
+# define SQLITE_ENABLE_EXPLAIN_COMMENTS 1
+#endif
+
+/*
+** The testcase() macro is used to aid in coverage testing.  When
+** doing coverage testing, the condition inside the argument to
+** testcase() must be evaluated both true and false in order to
+** get full branch coverage.  The testcase() macro is inserted
+** to help ensure adequate test coverage in places where simple
+** condition/decision coverage is inadequate.  For example, testcase()
+** can be used to make sure boundary values are tested.  For
+** bitmask tests, testcase() can be used to make sure each bit
+** is significant and used at least once.  On switch statements
+** where multiple cases go to the same block of code, testcase()
+** can insure that all cases are evaluated.
+**
+*/
+#ifdef SQLITE_COVERAGE_TEST
+SQLITE_PRIVATE   void sqlite3Coverage(int);
+# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
+#else
+# define testcase(X)
+#endif
+
+/*
+** The TESTONLY macro is used to enclose variable declarations or
+** other bits of code that are needed to support the arguments
+** within testcase() and assert() macros.
+*/
+#if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
+# define TESTONLY(X)  X
+#else
+# define TESTONLY(X)
+#endif
+
+/*
+** Sometimes we need a small amount of code such as a variable initialization
+** to setup for a later assert() statement.  We do not want this code to
+** appear when assert() is disabled.  The following macro is therefore
+** used to contain that setup code.  The "VVA" acronym stands for
+** "Verification, Validation, and Accreditation".  In other words, the
+** code within VVA_ONLY() will only run during verification processes.
+*/
+#ifndef NDEBUG
+# define VVA_ONLY(X)  X
+#else
+# define VVA_ONLY(X)
+#endif
+
+/*
+** The ALWAYS and NEVER macros surround boolean expressions which
+** are intended to always be true or false, respectively.  Such
+** expressions could be omitted from the code completely.  But they
+** are included in a few cases in order to enhance the resilience
+** of SQLite to unexpected behavior - to make the code "self-healing"
+** or "ductile" rather than being "brittle" and crashing at the first
+** hint of unplanned behavior.
+**
+** In other words, ALWAYS and NEVER are added for defensive code.
+**
+** When doing coverage testing ALWAYS and NEVER are hard-coded to
+** be true and false so that the unreachable code they specify will
+** not be counted as untested code.
+*/
+#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
+# define ALWAYS(X)      (1)
+# define NEVER(X)       (0)
+#elif !defined(NDEBUG)
+# define ALWAYS(X)      ((X)?1:(assert(0),0))
+# define NEVER(X)       ((X)?(assert(0),1):0)
+#else
+# define ALWAYS(X)      (X)
+# define NEVER(X)       (X)
+#endif
+
+/*
+** Some malloc failures are only possible if SQLITE_TEST_REALLOC_STRESS is
+** defined.  We need to defend against those failures when testing with
+** SQLITE_TEST_REALLOC_STRESS, but we don't want the unreachable branches
+** during a normal build.  The following macro can be used to disable tests
+** that are always false except when SQLITE_TEST_REALLOC_STRESS is set.
+*/
+#if defined(SQLITE_TEST_REALLOC_STRESS)
+# define ONLY_IF_REALLOC_STRESS(X)  (X)
+#elif !defined(NDEBUG)
+# define ONLY_IF_REALLOC_STRESS(X)  ((X)?(assert(0),1):0)
+#else
+# define ONLY_IF_REALLOC_STRESS(X)  (0)
+#endif
+
+/*
+** Declarations used for tracing the operating system interfaces.
+*/
+#if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \
+    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
+  extern int sqlite3OSTrace;
+# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
+# define SQLITE_HAVE_OS_TRACE
+#else
+# define OSTRACE(X)
+# undef  SQLITE_HAVE_OS_TRACE
+#endif
+
+/*
+** Is the sqlite3ErrName() function needed in the build?  Currently,
+** it is needed by "mutex_w32.c" (when debugging), "os_win.c" (when
+** OSTRACE is enabled), and by several "test*.c" files (which are
+** compiled using SQLITE_TEST).
+*/
+#if defined(SQLITE_HAVE_OS_TRACE) || defined(SQLITE_TEST) || \
+    (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
+# define SQLITE_NEED_ERR_NAME
+#else
+# undef  SQLITE_NEED_ERR_NAME
+#endif
+
+/*
+** SQLITE_ENABLE_EXPLAIN_COMMENTS is incompatible with SQLITE_OMIT_EXPLAIN
+*/
+#ifdef SQLITE_OMIT_EXPLAIN
+# undef SQLITE_ENABLE_EXPLAIN_COMMENTS
+#endif
+
+/*
+** Return true (non-zero) if the input is an integer that is too large
+** to fit in 32-bits.  This macro is used inside of various testcase()
+** macros to verify that we have tested SQLite for large-file support.
+*/
+#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
+
+/*
+** The macro unlikely() is a hint that surrounds a boolean
+** expression that is usually false.  Macro likely() surrounds
+** a boolean expression that is usually true.  These hints could,
+** in theory, be used by the compiler to generate better code, but
+** currently they are just comments for human readers.
+*/
+#define likely(X)    (X)
+#define unlikely(X)  (X)
+
 /************** Include hash.h in the middle of sqliteInt.h ******************/
 /************** Begin file hash.h ********************************************/
 /*
@@ -7350,11 +11170,11 @@ struct sqlite3_rtree_geometry {
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.
 */
-#ifndef _SQLITE_HASH_H_
-#define _SQLITE_HASH_H_
+#ifndef SQLITE_HASH_H
+#define SQLITE_HASH_H
 
 /* Forward declarations of structures. */
 typedef struct Hash Hash;
@@ -7400,15 +11220,15 @@ struct Hash {
 struct HashElem {
   HashElem *next, *prev;       /* Next and previous elements in the table */
   void *data;                  /* Data associated with this element */
-  const char *pKey; int nKey;  /* Key associated with this element */
+  const char *pKey;            /* Key associated with this element */
 };
 
 /*
 ** Access routines.  To delete, insert a NULL pointer.
 */
 SQLITE_PRIVATE void sqlite3HashInit(Hash*);
-SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, int nKey, void *pData);
-SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey, int nKey);
+SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, void *pData);
+SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey);
 SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 
 /*
@@ -7434,169 +11254,180 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 */
 /* #define sqliteHashCount(H)  ((H)->count) // NOT USED */
 
-#endif /* _SQLITE_HASH_H_ */
+#endif /* SQLITE_HASH_H */
 
 /************** End of hash.h ************************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
 /************** Include parse.h in the middle of sqliteInt.h *****************/
 /************** Begin file parse.h *******************************************/
-#define TK_SEMI                            1
-#define TK_EXPLAIN                         2
-#define TK_QUERY                           3
-#define TK_PLAN                            4
-#define TK_BEGIN                           5
-#define TK_TRANSACTION                     6
-#define TK_DEFERRED                        7
-#define TK_IMMEDIATE                       8
-#define TK_EXCLUSIVE                       9
-#define TK_COMMIT                         10
-#define TK_END                            11
-#define TK_ROLLBACK                       12
-#define TK_SAVEPOINT                      13
-#define TK_RELEASE                        14
-#define TK_TO                             15
-#define TK_TABLE                          16
-#define TK_CREATE                         17
-#define TK_IF                             18
-#define TK_NOT                            19
-#define TK_EXISTS                         20
-#define TK_TEMP                           21
-#define TK_LP                             22
-#define TK_RP                             23
-#define TK_AS                             24
-#define TK_COMMA                          25
-#define TK_ID                             26
-#define TK_INDEXED                        27
-#define TK_ABORT                          28
-#define TK_ACTION                         29
-#define TK_AFTER                          30
-#define TK_ANALYZE                        31
-#define TK_ASC                            32
-#define TK_ATTACH                         33
-#define TK_BEFORE                         34
-#define TK_BY                             35
-#define TK_CASCADE                        36
-#define TK_CAST                           37
-#define TK_COLUMNKW                       38
-#define TK_CONFLICT                       39
-#define TK_DATABASE                       40
-#define TK_DESC                           41
-#define TK_DETACH                         42
-#define TK_EACH                           43
-#define TK_FAIL                           44
-#define TK_FOR                            45
-#define TK_IGNORE                         46
-#define TK_INITIALLY                      47
-#define TK_INSTEAD                        48
-#define TK_LIKE_KW                        49
-#define TK_MATCH                          50
-#define TK_NO                             51
-#define TK_KEY                            52
-#define TK_OF                             53
-#define TK_OFFSET                         54
-#define TK_PRAGMA                         55
-#define TK_RAISE                          56
-#define TK_REPLACE                        57
-#define TK_RESTRICT                       58
-#define TK_ROW                            59
-#define TK_TRIGGER                        60
-#define TK_VACUUM                         61
-#define TK_VIEW                           62
-#define TK_VIRTUAL                        63
-#define TK_REINDEX                        64
-#define TK_RENAME                         65
-#define TK_CTIME_KW                       66
-#define TK_ANY                            67
-#define TK_OR                             68
-#define TK_AND                            69
-#define TK_IS                             70
-#define TK_BETWEEN                        71
-#define TK_IN                             72
-#define TK_ISNULL                         73
-#define TK_NOTNULL                        74
-#define TK_NE                             75
-#define TK_EQ                             76
-#define TK_GT                             77
-#define TK_LE                             78
-#define TK_LT                             79
-#define TK_GE                             80
-#define TK_ESCAPE                         81
-#define TK_BITAND                         82
-#define TK_BITOR                          83
-#define TK_LSHIFT                         84
-#define TK_RSHIFT                         85
-#define TK_PLUS                           86
-#define TK_MINUS                          87
-#define TK_STAR                           88
-#define TK_SLASH                          89
-#define TK_REM                            90
-#define TK_CONCAT                         91
-#define TK_COLLATE                        92
-#define TK_BITNOT                         93
-#define TK_STRING                         94
-#define TK_JOIN_KW                        95
-#define TK_CONSTRAINT                     96
-#define TK_DEFAULT                        97
-#define TK_NULL                           98
-#define TK_PRIMARY                        99
-#define TK_UNIQUE                         100
-#define TK_CHECK                          101
-#define TK_REFERENCES                     102
-#define TK_AUTOINCR                       103
-#define TK_ON                             104
-#define TK_INSERT                         105
-#define TK_DELETE                         106
-#define TK_UPDATE                         107
-#define TK_SET                            108
-#define TK_DEFERRABLE                     109
-#define TK_FOREIGN                        110
-#define TK_DROP                           111
-#define TK_UNION                          112
-#define TK_ALL                            113
-#define TK_EXCEPT                         114
-#define TK_INTERSECT                      115
-#define TK_SELECT                         116
-#define TK_DISTINCT                       117
-#define TK_DOT                            118
-#define TK_FROM                           119
-#define TK_JOIN                           120
-#define TK_USING                          121
-#define TK_ORDER                          122
-#define TK_GROUP                          123
-#define TK_HAVING                         124
-#define TK_LIMIT                          125
-#define TK_WHERE                          126
-#define TK_INTO                           127
-#define TK_VALUES                         128
-#define TK_INTEGER                        129
-#define TK_FLOAT                          130
-#define TK_BLOB                           131
-#define TK_REGISTER                       132
-#define TK_VARIABLE                       133
-#define TK_CASE                           134
-#define TK_WHEN                           135
-#define TK_THEN                           136
-#define TK_ELSE                           137
-#define TK_INDEX                          138
-#define TK_ALTER                          139
-#define TK_ADD                            140
-#define TK_TO_TEXT                        141
-#define TK_TO_BLOB                        142
-#define TK_TO_NUMERIC                     143
-#define TK_TO_INT                         144
-#define TK_TO_REAL                        145
-#define TK_ISNOT                          146
-#define TK_END_OF_FILE                    147
-#define TK_ILLEGAL                        148
-#define TK_SPACE                          149
+#define TK_SEMI                             1
+#define TK_EXPLAIN                          2
+#define TK_QUERY                            3
+#define TK_PLAN                             4
+#define TK_BEGIN                            5
+#define TK_TRANSACTION                      6
+#define TK_DEFERRED                         7
+#define TK_IMMEDIATE                        8
+#define TK_EXCLUSIVE                        9
+#define TK_COMMIT                          10
+#define TK_END                             11
+#define TK_ROLLBACK                        12
+#define TK_SAVEPOINT                       13
+#define TK_RELEASE                         14
+#define TK_TO                              15
+#define TK_TABLE                           16
+#define TK_CREATE                          17
+#define TK_IF                              18
+#define TK_NOT                             19
+#define TK_EXISTS                          20
+#define TK_TEMP                            21
+#define TK_LP                              22
+#define TK_RP                              23
+#define TK_AS                              24
+#define TK_WITHOUT                         25
+#define TK_COMMA                           26
+#define TK_OR                              27
+#define TK_AND                             28
+#define TK_IS                              29
+#define TK_MATCH                           30
+#define TK_LIKE_KW                         31
+#define TK_BETWEEN                         32
+#define TK_IN                              33
+#define TK_ISNULL                          34
+#define TK_NOTNULL                         35
+#define TK_NE                              36
+#define TK_EQ                              37
+#define TK_GT                              38
+#define TK_LE                              39
+#define TK_LT                              40
+#define TK_GE                              41
+#define TK_ESCAPE                          42
+#define TK_BITAND                          43
+#define TK_BITOR                           44
+#define TK_LSHIFT                          45
+#define TK_RSHIFT                          46
+#define TK_PLUS                            47
+#define TK_MINUS                           48
+#define TK_STAR                            49
+#define TK_SLASH                           50
+#define TK_REM                             51
+#define TK_CONCAT                          52
+#define TK_COLLATE                         53
+#define TK_BITNOT                          54
+#define TK_ID                              55
+#define TK_INDEXED                         56
+#define TK_ABORT                           57
+#define TK_ACTION                          58
+#define TK_AFTER                           59
+#define TK_ANALYZE                         60
+#define TK_ASC                             61
+#define TK_ATTACH                          62
+#define TK_BEFORE                          63
+#define TK_BY                              64
+#define TK_CASCADE                         65
+#define TK_CAST                            66
+#define TK_COLUMNKW                        67
+#define TK_CONFLICT                        68
+#define TK_DATABASE                        69
+#define TK_DESC                            70
+#define TK_DETACH                          71
+#define TK_EACH                            72
+#define TK_FAIL                            73
+#define TK_FOR                             74
+#define TK_IGNORE                          75
+#define TK_INITIALLY                       76
+#define TK_INSTEAD                         77
+#define TK_NO                              78
+#define TK_KEY                             79
+#define TK_OF                              80
+#define TK_OFFSET                          81
+#define TK_PRAGMA                          82
+#define TK_RAISE                           83
+#define TK_RECURSIVE                       84
+#define TK_REPLACE                         85
+#define TK_RESTRICT                        86
+#define TK_ROW                             87
+#define TK_TRIGGER                         88
+#define TK_VACUUM                          89
+#define TK_VIEW                            90
+#define TK_VIRTUAL                         91
+#define TK_WITH                            92
+#define TK_REINDEX                         93
+#define TK_RENAME                          94
+#define TK_CTIME_KW                        95
+#define TK_ANY                             96
+#define TK_STRING                          97
+#define TK_JOIN_KW                         98
+#define TK_CONSTRAINT                      99
+#define TK_DEFAULT                        100
+#define TK_NULL                           101
+#define TK_PRIMARY                        102
+#define TK_UNIQUE                         103
+#define TK_CHECK                          104
+#define TK_REFERENCES                     105
+#define TK_AUTOINCR                       106
+#define TK_ON                             107
+#define TK_INSERT                         108
+#define TK_DELETE                         109
+#define TK_UPDATE                         110
+#define TK_SET                            111
+#define TK_DEFERRABLE                     112
+#define TK_FOREIGN                        113
+#define TK_DROP                           114
+#define TK_UNION                          115
+#define TK_ALL                            116
+#define TK_EXCEPT                         117
+#define TK_INTERSECT                      118
+#define TK_SELECT                         119
+#define TK_VALUES                         120
+#define TK_DISTINCT                       121
+#define TK_DOT                            122
+#define TK_FROM                           123
+#define TK_JOIN                           124
+#define TK_USING                          125
+#define TK_ORDER                          126
+#define TK_GROUP                          127
+#define TK_HAVING                         128
+#define TK_LIMIT                          129
+#define TK_WHERE                          130
+#define TK_INTO                           131
+#define TK_INTEGER                        132
+#define TK_FLOAT                          133
+#define TK_BLOB                           134
+#define TK_VARIABLE                       135
+#define TK_CASE                           136
+#define TK_WHEN                           137
+#define TK_THEN                           138
+#define TK_ELSE                           139
+#define TK_INDEX                          140
+#define TK_ALTER                          141
+#define TK_ADD                            142
+#define TK_TO_TEXT                        143
+#define TK_TO_BLOB                        144
+#define TK_TO_NUMERIC                     145
+#define TK_TO_INT                         146
+#define TK_TO_REAL                        147
+#define TK_ISNOT                          148
+#define TK_END_OF_FILE                    149
 #define TK_UNCLOSED_STRING                150
 #define TK_FUNCTION                       151
 #define TK_COLUMN                         152
 #define TK_AGG_FUNCTION                   153
 #define TK_AGG_COLUMN                     154
-#define TK_CONST_FUNC                     155
-#define TK_UMINUS                         156
-#define TK_UPLUS                          157
+#define TK_UMINUS                         155
+#define TK_UPLUS                          156
+#define TK_REGISTER                       157
+#define TK_ASTERISK                       158
+#define TK_SPAN                           159
+#define TK_SPACE                          160
+#define TK_ILLEGAL                        161
+
+/* The token codes above must all fit in 8 bits */
+#define TKFLG_MASK           0xff  
+
+/* Flags that can be added to a token code when it is not
+** being stored in a u8: */
+#define TKFLG_DONTFOLD       0x100  /* Omit constant folding optimizations */
 
 /************** End of parse.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -7628,7 +11459,7 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 
 /*
 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
-** afterward. Having this macro allows us to cause the C compiler 
+** afterward. Having this macro allows us to cause the C compiler
 ** to omit code used by TEMP tables without messy #ifndef statements.
 */
 #ifdef SQLITE_OMIT_TEMPDB
@@ -7645,7 +11476,7 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 */
 #define SQLITE_MAX_FILE_FORMAT 4
 #ifndef SQLITE_DEFAULT_FILE_FORMAT
-# define SQLITE_DEFAULT_FILE_FORMAT 1
+# define SQLITE_DEFAULT_FILE_FORMAT 4
 #endif
 
 /*
@@ -7662,6 +11493,37 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 */
 #ifndef SQLITE_TEMP_STORE
 # define SQLITE_TEMP_STORE 1
+# define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
+#endif
+
+/*
+** If no value has been provided for SQLITE_MAX_WORKER_THREADS, or if
+** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it
+** to zero.
+*/
+#if SQLITE_TEMP_STORE==3 || SQLITE_THREADSAFE==0
+# undef SQLITE_MAX_WORKER_THREADS
+# define SQLITE_MAX_WORKER_THREADS 0
+#endif
+#ifndef SQLITE_MAX_WORKER_THREADS
+# define SQLITE_MAX_WORKER_THREADS 8
+#endif
+#ifndef SQLITE_DEFAULT_WORKER_THREADS
+# define SQLITE_DEFAULT_WORKER_THREADS 0
+#endif
+#if SQLITE_DEFAULT_WORKER_THREADS>SQLITE_MAX_WORKER_THREADS
+# undef SQLITE_MAX_WORKER_THREADS
+# define SQLITE_MAX_WORKER_THREADS SQLITE_DEFAULT_WORKER_THREADS
+#endif
+
+/*
+** The default initial allocation for the pagecache when using separate
+** pagecaches for each database connection.  A positive number is the
+** number of pages.  A negative number N translations means that a buffer
+** of -1024*N bytes is allocated and used for as many pages as it will hold.
+*/
+#ifndef SQLITE_DEFAULT_PCACHE_INITSZ
+# define SQLITE_DEFAULT_PCACHE_INITSZ 100
 #endif
 
 /*
@@ -7673,6 +11535,21 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash*);
 #endif
 
 /*
+** Macros to compute minimum and maximum of two numbers.
+*/
+#ifndef MIN
+# define MIN(A,B) ((A)<(B)?(A):(B))
+#endif
+#ifndef MAX
+# define MAX(A,B) ((A)>(B)?(A):(B))
+#endif
+
+/*
+** Swap two objects of type TYPE.
+*/
+#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
+
+/*
 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
 ** not, there are still machines out there that use EBCDIC.)
 */
@@ -7756,23 +11633,100 @@ typedef INT8_TYPE i8;              /* 1-byte signed integer */
 #endif
 
 /*
-** Macros to determine whether the machine is big or little endian,
-** evaluated at runtime.
+** Estimated quantities used for query planning are stored as 16-bit
+** logarithms.  For quantity X, the value stored is 10*log2(X).  This
+** gives a possible range of values of approximately 1.0e986 to 1e-986.
+** But the allowed values are "grainy".  Not every value is representable.
+** For example, quantities 16 and 17 are both represented by a LogEst
+** of 40.  However, since LogEst quantities are suppose to be estimates,
+** not exact values, this imprecision is not a problem.
+**
+** "LogEst" is short for "Logarithmic Estimate".
+**
+** Examples:
+**      1 -> 0              20 -> 43          10000 -> 132
+**      2 -> 10             25 -> 46          25000 -> 146
+**      3 -> 16            100 -> 66        1000000 -> 199
+**      4 -> 20           1000 -> 99        1048576 -> 200
+**     10 -> 33           1024 -> 100    4294967296 -> 320
+**
+** The LogEst can be negative to indicate fractional values.
+** Examples:
+**
+**    0.5 -> -10           0.1 -> -33        0.0625 -> -40
 */
-#ifdef SQLITE_AMALGAMATION
-SQLITE_PRIVATE const int sqlite3one = 1;
+typedef INT16_TYPE LogEst;
+
+/*
+** Set the SQLITE_PTRSIZE macro to the number of bytes in a pointer
+*/
+#ifndef SQLITE_PTRSIZE
+# if defined(__SIZEOF_POINTER__)
+#   define SQLITE_PTRSIZE __SIZEOF_POINTER__
+# elif defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
+       defined(_M_ARM)   || defined(__arm__)    || defined(__x86)
+#   define SQLITE_PTRSIZE 4
+# else
+#   define SQLITE_PTRSIZE 8
+# endif
+#endif
+
+/* The uptr type is an unsigned integer large enough to hold a pointer
+*/
+#if defined(HAVE_STDINT_H)
+  typedef uintptr_t uptr;
+#elif SQLITE_PTRSIZE==4
+  typedef u32 uptr;
 #else
-SQLITE_PRIVATE const int sqlite3one;
+  typedef u64 uptr;
 #endif
-#if defined(i386) || defined(__i386__) || defined(_M_IX86)\
-                             || defined(__x86_64) || defined(__x86_64__)
+
+/*
+** The SQLITE_WITHIN(P,S,E) macro checks to see if pointer P points to
+** something between S (inclusive) and E (exclusive).
+**
+** In other words, S is a buffer and E is a pointer to the first byte after
+** the end of buffer S.  This macro returns true if P points to something
+** contained within the buffer S.
+*/
+#define SQLITE_WITHIN(P,S,E) (((uptr)(P)>=(uptr)(S))&&((uptr)(P)<(uptr)(E)))
+
+
+/*
+** Macros to determine whether the machine is big or little endian,
+** and whether or not that determination is run-time or compile-time.
+**
+** For best performance, an attempt is made to guess at the byte-order
+** using C-preprocessor macros.  If that is unsuccessful, or if
+** -DSQLITE_RUNTIME_BYTEORDER=1 is set, then byte-order is determined
+** at run-time.
+*/
+#if (defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
+     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
+     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
+     defined(__arm__)) && !defined(SQLITE_RUNTIME_BYTEORDER)
+# define SQLITE_BYTEORDER    1234
 # define SQLITE_BIGENDIAN    0
 # define SQLITE_LITTLEENDIAN 1
 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
-#else
+#endif
+#if (defined(sparc)    || defined(__ppc__))  \
+    && !defined(SQLITE_RUNTIME_BYTEORDER)
+# define SQLITE_BYTEORDER    4321
+# define SQLITE_BIGENDIAN    1
+# define SQLITE_LITTLEENDIAN 0
+# define SQLITE_UTF16NATIVE  SQLITE_UTF16BE
+#endif
+#if !defined(SQLITE_BYTEORDER)
+# ifdef SQLITE_AMALGAMATION
+  const int sqlite3one = 1;
+# else
+  extern const int sqlite3one;
+# endif
+# define SQLITE_BYTEORDER    0     /* 0 means "unknown at compile-time" */
 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
-# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
+# define SQLITE_UTF16NATIVE  (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
 #endif
 
 /*
@@ -7783,7 +11737,7 @@ SQLITE_PRIVATE const int sqlite3one;
 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
 
-/* 
+/*
 ** Round up a number to the next larger multiple of 8.  This is used
 ** to force 8-byte alignment on 64-bit architectures.
 */
@@ -7800,7 +11754,7 @@ SQLITE_PRIVATE const int sqlite3one;
 ** all alignment restrictions correct.
 **
 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
-** underlying malloc() implemention might return us 4-byte aligned
+** underlying malloc() implementation might return us 4-byte aligned
 ** pointers.  In that case, only verify 4-byte alignment.
 */
 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
@@ -7809,10 +11763,75 @@ SQLITE_PRIVATE const int sqlite3one;
 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
 #endif
 
+/*
+** Disable MMAP on platforms where it is known to not work
+*/
+#if defined(__OpenBSD__) || defined(__QNXNTO__)
+# undef SQLITE_MAX_MMAP_SIZE
+# define SQLITE_MAX_MMAP_SIZE 0
+#endif
+
+/*
+** Default maximum size of memory used by memory-mapped I/O in the VFS
+*/
+#ifdef __APPLE__
+# include <TargetConditionals.h>
+#endif
+#ifndef SQLITE_MAX_MMAP_SIZE
+# if defined(__linux__) \
+  || defined(_WIN32) \
+  || (defined(__APPLE__) && defined(__MACH__)) \
+  || defined(__sun) \
+  || defined(__FreeBSD__) \
+  || defined(__DragonFly__)
+#   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
+# else
+#   define SQLITE_MAX_MMAP_SIZE 0
+# endif
+# define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
+#endif
+
+/*
+** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger
+** default MMAP_SIZE is specified at compile-time, make sure that it does
+** not exceed the maximum mmap size.
+*/
+#ifndef SQLITE_DEFAULT_MMAP_SIZE
+# define SQLITE_DEFAULT_MMAP_SIZE 0
+# define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
+#endif
+#if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
+# undef SQLITE_DEFAULT_MMAP_SIZE
+# define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
+#endif
+
+/*
+** Only one of SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4 can be defined.
+** Priority is given to SQLITE_ENABLE_STAT4.  If either are defined, also
+** define SQLITE_ENABLE_STAT3_OR_STAT4
+*/
+#ifdef SQLITE_ENABLE_STAT4
+# undef SQLITE_ENABLE_STAT3
+# define SQLITE_ENABLE_STAT3_OR_STAT4 1
+#elif SQLITE_ENABLE_STAT3
+# define SQLITE_ENABLE_STAT3_OR_STAT4 1
+#elif SQLITE_ENABLE_STAT3_OR_STAT4
+# undef SQLITE_ENABLE_STAT3_OR_STAT4
+#endif
+
+/*
+** SELECTTRACE_ENABLED will be either 1 or 0 depending on whether or not
+** the Select query generator tracing logic is turned on.
+*/
+#if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_SELECTTRACE)
+# define SELECTTRACE_ENABLED 1
+#else
+# define SELECTTRACE_ENABLED 0
+#endif
 
 /*
 ** An instance of the following structure is used to store the busy-handler
-** callback for a given sqlite handle. 
+** callback for a given sqlite handle.
 **
 ** The sqlite.busyHandler member of the sqlite struct contains the busy
 ** callback for the database handle. Each pager opened via the sqlite
@@ -7851,10 +11870,19 @@ struct BusyHandler {
 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
 
 /*
+** Determine if the argument is a power of two
+*/
+#define IsPowerOfTwo(X) (((X)&((X)-1))==0)
+
+/*
 ** The following value as a destructor means to use sqlite3DbFree().
-** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
+** The sqlite3DbFree() routine requires two parameters instead of the
+** one parameter that destructors normally want.  So we have to introduce
+** this magic value that the code knows to handle differently.  Any
+** pointer will work here as long as it is distinct from SQLITE_STATIC
+** and SQLITE_TRANSIENT.
 */
-#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
+#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
 
 /*
 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
@@ -7874,19 +11902,19 @@ struct BusyHandler {
   #define SQLITE_WSD const
   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
-SQLITE_API   int sqlite3_wsd_init(int N, int J);
-SQLITE_API   void *sqlite3_wsd_find(void *K, int L);
+SQLITE_API int SQLITE_STDCALL sqlite3_wsd_init(int N, int J);
+SQLITE_API void *SQLITE_STDCALL sqlite3_wsd_find(void *K, int L);
 #else
-  #define SQLITE_WSD 
+  #define SQLITE_WSD
   #define GLOBAL(t,v) v
   #define sqlite3GlobalConfig sqlite3Config
 #endif
 
 /*
 ** The following macros are used to suppress compiler warnings and to
-** make it clear to human readers when a function parameter is deliberately 
+** make it clear to human readers when a function parameter is deliberately
 ** left unused within the body of a function. This usually happens when
-** a function is called via a function pointer. For example the 
+** a function is called via a function pointer. For example the
 ** implementation of an SQL aggregate step callback may not use the
 ** parameter indicating the number of arguments passed to the aggregate,
 ** if it knows that this is enforced elsewhere.
@@ -7929,14 +11957,19 @@ typedef struct LookasideSlot LookasideSlot;
 typedef struct Module Module;
 typedef struct NameContext NameContext;
 typedef struct Parse Parse;
+typedef struct PreUpdate PreUpdate;
+typedef struct PrintfArguments PrintfArguments;
 typedef struct RowSet RowSet;
 typedef struct Savepoint Savepoint;
 typedef struct Select Select;
+typedef struct SQLiteThread SQLiteThread;
+typedef struct SelectDest SelectDest;
 typedef struct SrcList SrcList;
 typedef struct StrAccum StrAccum;
 typedef struct Table Table;
 typedef struct TableLock TableLock;
 typedef struct Token Token;
+typedef struct TreeView TreeView;
 typedef struct Trigger Trigger;
 typedef struct TriggerPrg TriggerPrg;
 typedef struct TriggerStep TriggerStep;
@@ -7944,12 +11977,11 @@ typedef struct UnpackedRecord UnpackedRecord;
 typedef struct VTable VTable;
 typedef struct VtabCtx VtabCtx;
 typedef struct Walker Walker;
-typedef struct WherePlan WherePlan;
 typedef struct WhereInfo WhereInfo;
-typedef struct WhereLevel WhereLevel;
+typedef struct With With;
 
 /*
-** Defer sourcing vdbe.h and btree.h until after the "u8" and 
+** Defer sourcing vdbe.h and btree.h until after the "u8" and
 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
 ** pointer types (i.e. FuncDef) defined above.
 */
@@ -7970,13 +12002,13 @@ typedef struct WhereLevel WhereLevel;
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 */
-#ifndef _BTREE_H_
-#define _BTREE_H_
+#ifndef SQLITE_BTREE_H
+#define SQLITE_BTREE_H
 
 /* TODO: This definition is just included so other modules compile. It
 ** needs to be revisited.
 */
-#define SQLITE_N_BTREE_META 10
+#define SQLITE_N_BTREE_META 16
 
 /*
 ** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
@@ -7996,6 +12028,7 @@ typedef struct WhereLevel WhereLevel;
 typedef struct Btree Btree;
 typedef struct BtCursor BtCursor;
 typedef struct BtShared BtShared;
+typedef struct BtreePayload BtreePayload;
 
 
 SQLITE_PRIVATE int sqlite3BtreeOpen(
@@ -8014,28 +12047,31 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 ** pager.h.
 */
 #define BTREE_OMIT_JOURNAL  1  /* Do not create or use a rollback journal */
-#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
-#define BTREE_MEMORY        4  /* This is an in-memory DB */
-#define BTREE_SINGLE        8  /* The file contains at most 1 b-tree */
-#define BTREE_UNORDERED    16  /* Use of a hash implementation is OK */
+#define BTREE_MEMORY        2  /* This is an in-memory DB */
+#define BTREE_SINGLE        4  /* The file contains at most 1 b-tree */
+#define BTREE_UNORDERED     8  /* Use of a hash implementation is OK */
 
 SQLITE_PRIVATE int sqlite3BtreeClose(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree*,int);
-SQLITE_PRIVATE int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
-SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree*);
+SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree*,int);
+#if SQLITE_MAX_MMAP_SIZE>0
+SQLITE_PRIVATE   int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);
+#endif
+SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(Btree*,unsigned);
 SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
 SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree*,int);
 SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree*);
 SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree*,int);
-SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree*);
+SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree*);
+SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p);
 SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int);
 SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *);
 SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int);
 SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
 SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree*, int);
 SQLITE_PRIVATE int sqlite3BtreeCommit(Btree*);
-SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*);
+SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*,int,int);
 SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree*,int);
 SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree*, int*, int flags);
 SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree*);
@@ -8067,11 +12103,14 @@ SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *);
 
 SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree*, int, int*);
 SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int, int*);
-SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree*, int);
+SQLITE_PRIVATE int sqlite3BtreeClearTableOfCursor(BtCursor*);
+SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree*, int, int);
 
 SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
 SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
 
+SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p);
+
 /*
 ** The second parameter to sqlite3BtreeGetMeta or sqlite3BtreeUpdateMeta
 ** should be one of the following values. The integer values are assigned 
@@ -8083,6 +12122,11 @@ SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
 ** For example, the free-page-count field is located at byte offset 36 of
 ** the database file header. The incr-vacuum-flag field is located at
 ** byte offset 64 (== 36+4*7).
+**
+** The BTREE_DATA_VERSION value is not really a value stored in the header.
+** It is a read-only number computed by the pager.  But we merge it with
+** the header value access routines since its access pattern is the same.
+** Call it a "virtual meta value".
 */
 #define BTREE_FREE_PAGE_COUNT     0
 #define BTREE_SCHEMA_VERSION      1
@@ -8092,6 +12136,79 @@ SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);
 #define BTREE_TEXT_ENCODING       5
 #define BTREE_USER_VERSION        6
 #define BTREE_INCR_VACUUM         7
+#define BTREE_APPLICATION_ID      8
+#define BTREE_DATA_VERSION        15  /* A virtual meta-value */
+
+/*
+** Kinds of hints that can be passed into the sqlite3BtreeCursorHint()
+** interface.
+**
+** BTREE_HINT_RANGE  (arguments: Expr*, Mem*)
+**
+**     The first argument is an Expr* (which is guaranteed to be constant for
+**     the lifetime of the cursor) that defines constraints on which rows
+**     might be fetched with this cursor.  The Expr* tree may contain
+**     TK_REGISTER nodes that refer to values stored in the array of registers
+**     passed as the second parameter.  In other words, if Expr.op==TK_REGISTER
+**     then the value of the node is the value in Mem[pExpr.iTable].  Any
+**     TK_COLUMN node in the expression tree refers to the Expr.iColumn-th
+**     column of the b-tree of the cursor.  The Expr tree will not contain
+**     any function calls nor subqueries nor references to b-trees other than
+**     the cursor being hinted.
+**
+**     The design of the _RANGE hint is aid b-tree implementations that try
+**     to prefetch content from remote machines - to provide those
+**     implementations with limits on what needs to be prefetched and thereby
+**     reduce network bandwidth.
+**
+** Note that BTREE_HINT_FLAGS with BTREE_BULKLOAD is the only hint used by
+** standard SQLite.  The other hints are provided for extentions that use
+** the SQLite parser and code generator but substitute their own storage
+** engine.
+*/
+#define BTREE_HINT_RANGE 0       /* Range constraints on queries */
+
+/*
+** Values that may be OR'd together to form the argument to the
+** BTREE_HINT_FLAGS hint for sqlite3BtreeCursorHint():
+**
+** The BTREE_BULKLOAD flag is set on index cursors when the index is going
+** to be filled with content that is already in sorted order.
+**
+** The BTREE_SEEK_EQ flag is set on cursors that will get OP_SeekGE or
+** OP_SeekLE opcodes for a range search, but where the range of entries
+** selected will all have the same key.  In other words, the cursor will
+** be used only for equality key searches.
+**
+*/
+#define BTREE_BULKLOAD 0x00000001  /* Used to full index in sorted order */
+#define BTREE_SEEK_EQ  0x00000002  /* EQ seeks only - no range seeks */
+
+/* 
+** Flags passed as the third argument to sqlite3BtreeCursor().
+**
+** For read-only cursors the wrFlag argument is always zero. For read-write
+** cursors it may be set to either (BTREE_WRCSR|BTREE_FORDELETE) or just
+** (BTREE_WRCSR). If the BTREE_FORDELETE bit is set, then the cursor will
+** only be used by SQLite for the following:
+**
+**   * to seek to and then delete specific entries, and/or
+**
+**   * to read values that will be used to create keys that other
+**     BTREE_FORDELETE cursors will seek to and delete.
+**
+** The BTREE_FORDELETE flag is an optimization hint.  It is not used by
+** by this, the native b-tree engine of SQLite, but it is available to
+** alternative storage engines that might be substituted in place of this
+** b-tree system.  For alternative storage engines in which a delete of
+** the main table row automatically deletes corresponding index rows,
+** the FORDELETE flag hint allows those alternative storage engines to
+** skip a lot of work.  Namely:  FORDELETE cursors may treat all SEEK
+** and DELETE operations as no-ops, and any READ operation against a
+** FORDELETE cursor may return a null row: 0x01 0x00.
+*/
+#define BTREE_WRCSR     0x00000004     /* read-write cursor */
+#define BTREE_FORDELETE 0x00000008     /* Cursor is for seek/delete only */
 
 SQLITE_PRIVATE int sqlite3BtreeCursor(
   Btree*,                              /* BTree containing table to open */
@@ -8102,6 +12219,10 @@ SQLITE_PRIVATE int sqlite3BtreeCursor(
 );
 SQLITE_PRIVATE int sqlite3BtreeCursorSize(void);
 SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor*);
+SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor*, unsigned);
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor*, int, ...);
+#endif
 
 SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
@@ -8111,33 +12232,63 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
   int bias,
   int *pRes
 );
-SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*, int*);
-SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*);
-SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const void *pKey, i64 nKey,
-                                  const void *pData, int nData,
-                                  int nZero, int bias, int seekResult);
+SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*);
+SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor*, int*);
+SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*, u8 flags);
+
+/* Allowed flags for the 2nd argument to sqlite3BtreeDelete() */
+#define BTREE_SAVEPOSITION 0x02  /* Leave cursor pointing at NEXT or PREV */
+#define BTREE_AUXDELETE    0x04  /* not the primary delete operation */
+
+/* An instance of the BtreePayload object describes the content of a single
+** entry in either an index or table btree.
+**
+** Index btrees (used for indexes and also WITHOUT ROWID tables) contain
+** an arbitrary key and no data.  These btrees have pKey,nKey set to their
+** key and pData,nData,nZero set to zero.
+**
+** Table btrees (used for rowid tables) contain an integer rowid used as
+** the key and passed in the nKey field.  The pKey field is zero.  
+** pData,nData hold the content of the new entry.  nZero extra zero bytes
+** are appended to the end of the content when constructing the entry.
+**
+** This object is used to pass information into sqlite3BtreeInsert().  The
+** same information used to be passed as five separate parameters.  But placing
+** the information into this object helps to keep the interface more 
+** organized and understandable, and it also helps the resulting code to
+** run a little faster by using fewer registers for parameter passing.
+*/
+struct BtreePayload {
+  const void *pKey;       /* Key content for indexes.  NULL for tables */
+  sqlite3_int64 nKey;     /* Size of pKey for indexes.  PRIMARY KEY for tabs */
+  const void *pData;      /* Data for tables.  NULL for indexes */
+  int nData;              /* Size of pData.  0 if none. */
+  int nZero;              /* Extra zero data appended after pData,nData */
+};
+
+SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,
+                       int bias, int seekResult);
 SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);
 SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);
 SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int *pRes);
 SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int *pRes);
-SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
+SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
-SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
-SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
-SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
+SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor*, u32 *pAmt);
+SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor*);
 SQLITE_PRIVATE int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);
-SQLITE_PRIVATE void sqlite3BtreeSetCachedRowid(BtCursor*, sqlite3_int64);
-SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeGetCachedRowid(BtCursor*);
 
 SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
 SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);
 
 SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
-SQLITE_PRIVATE void sqlite3BtreeCacheOverflow(BtCursor *);
+SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *);
 SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *);
-
 SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);
+SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor*, unsigned int mask);
+SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *pBt);
+SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void);
 
 #ifndef NDEBUG
 SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor*);
@@ -8164,15 +12315,19 @@ SQLITE_PRIVATE   int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);
 #ifndef SQLITE_OMIT_SHARED_CACHE
 SQLITE_PRIVATE   void sqlite3BtreeEnter(Btree*);
 SQLITE_PRIVATE   void sqlite3BtreeEnterAll(sqlite3*);
+SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);
+SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
+SQLITE_PRIVATE   int sqlite3BtreeConnectionCount(Btree*);
 #else
 # define sqlite3BtreeEnter(X) 
 # define sqlite3BtreeEnterAll(X)
+# define sqlite3BtreeSharable(X) 0
+# define sqlite3BtreeEnterCursor(X)
+# define sqlite3BtreeConnectionCount(X) 1
 #endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
-SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);
 SQLITE_PRIVATE   void sqlite3BtreeLeave(Btree*);
-SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);
 SQLITE_PRIVATE   void sqlite3BtreeLeaveCursor(BtCursor*);
 SQLITE_PRIVATE   void sqlite3BtreeLeaveAll(sqlite3*);
 #ifndef NDEBUG
@@ -8183,9 +12338,7 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 #endif
 #else
 
-# define sqlite3BtreeSharable(X) 0
 # define sqlite3BtreeLeave(X)
-# define sqlite3BtreeEnterCursor(X)
 # define sqlite3BtreeLeaveCursor(X)
 # define sqlite3BtreeLeaveAll(X)
 
@@ -8195,7 +12348,7 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 #endif
 
 
-#endif /* _BTREE_H_ */
+#endif /* SQLITE_BTREE_H */
 
 /************** End of btree.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -8218,8 +12371,8 @@ SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);
 ** or VDBE.  The VDBE implements an abstract machine that runs a
 ** simple program to access and modify the underlying database.
 */
-#ifndef _SQLITE_VDBE_H_
-#define _SQLITE_VDBE_H_
+#ifndef SQLITE_VDBE_H
+#define SQLITE_VDBE_H
 /* #include <stdio.h> */
 
 /*
@@ -8233,7 +12386,6 @@ typedef struct Vdbe Vdbe;
 ** The names of the following types declared in vdbeInt.h are required
 ** for the VdbeOp definition.
 */
-typedef struct VdbeFunc VdbeFunc;
 typedef struct Mem Mem;
 typedef struct SubProgram SubProgram;
 
@@ -8245,34 +12397,41 @@ typedef struct SubProgram SubProgram;
 struct VdbeOp {
   u8 opcode;          /* What operation to perform */
   signed char p4type; /* One of the P4_xxx constants for p4 */
-  u8 opflags;         /* Mask of the OPFLG_* flags in opcodes.h */
+  u8 notUsed1;
   u8 p5;              /* Fifth parameter is an unsigned character */
   int p1;             /* First operand */
   int p2;             /* Second parameter (often the jump destination) */
   int p3;             /* The third parameter */
-  union {             /* fourth parameter */
+  union p4union {     /* fourth parameter */
     int i;                 /* Integer value if p4type==P4_INT32 */
     void *p;               /* Generic pointer */
     char *z;               /* Pointer to data for string (char array) types */
     i64 *pI64;             /* Used when p4type is P4_INT64 */
     double *pReal;         /* Used when p4type is P4_REAL */
     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
-    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
+    sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */
     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
     Mem *pMem;             /* Used when p4type is P4_MEM */
     VTable *pVtab;         /* Used when p4type is P4_VTAB */
     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
     int *ai;               /* Used when p4type is P4_INTARRAY */
     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
+    Table *pTab;           /* Used when p4type is P4_TABLE */
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+    Expr *pExpr;           /* Used when p4type is P4_EXPR */
+#endif
     int (*xAdvance)(BtCursor *, int *);
   } p4;
-#ifdef SQLITE_DEBUG
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   char *zComment;          /* Comment to improve readability */
 #endif
 #ifdef VDBE_PROFILE
-  int cnt;                 /* Number of times this instruction was executed */
+  u32 cnt;                 /* Number of times this instruction was executed */
   u64 cycles;              /* Total time spent executing this instruction */
 #endif
+#ifdef SQLITE_VDBE_COVERAGE
+  int iSrcLine;            /* Source-code line that generated this opcode */
+#endif
 };
 typedef struct VdbeOp VdbeOp;
 
@@ -8285,6 +12444,7 @@ struct SubProgram {
   int nOp;                      /* Elements in aOp[] */
   int nMem;                     /* Number of memory cells required */
   int nCsr;                     /* Number of cursors required */
+  int nOnce;                    /* Number of OP_Once instructions */
   void *token;                  /* id that may be used to recursive triggers */
   SubProgram *pNext;            /* Next sub-program already visited */
 };
@@ -8310,7 +12470,7 @@ typedef struct VdbeOpList VdbeOpList;
 #define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
 #define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
 #define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
-#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
+#define P4_EXPR     (-7)  /* P4 is a pointer to an Expr tree */
 #define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
 #define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
@@ -8321,16 +12481,14 @@ typedef struct VdbeOpList VdbeOpList;
 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
 #define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
 #define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
+#define P4_TABLE    (-20) /* P4 is a pointer to a Table structure */
+#define P4_FUNCCTX  (-21) /* P4 is a pointer to an sqlite3_context object */
 
-/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
-** is made.  That copy is freed when the Vdbe is finalized.  But if the
-** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
-** gets freed when the Vdbe is finalized so it still should be obtained
-** from a single sqliteMalloc().  But no copy is made and the calling
-** function should *not* try to free the KeyInfo.
-*/
-#define P4_KEYINFO_HANDOFF (-16)
-#define P4_KEYINFO_STATIC  (-17)
+/* Error message codes for OP_Halt */
+#define P5_ConstraintNotNull 1
+#define P5_ConstraintUnique  2
+#define P5_ConstraintCheck   3
+#define P5_ConstraintFK      4
 
 /*
 ** The Vdbe.aColName array contains 5n Mem structures, where n is the 
@@ -8366,190 +12524,210 @@ typedef struct VdbeOpList VdbeOpList;
 /************** Include opcodes.h in the middle of vdbe.h ********************/
 /************** Begin file opcodes.h *****************************************/
 /* Automatically generated.  Do not edit */
-/* See the mkopcodeh.awk script for details */
-#define OP_Goto                                 1
-#define OP_Gosub                                2
-#define OP_Return                               3
-#define OP_Yield                                4
-#define OP_HaltIfNull                           5
-#define OP_Halt                                 6
-#define OP_Integer                              7
-#define OP_Int64                                8
-#define OP_Real                               130   /* same as TK_FLOAT    */
-#define OP_String8                             94   /* same as TK_STRING   */
-#define OP_String                               9
-#define OP_Null                                10
-#define OP_Blob                                11
-#define OP_Variable                            12
-#define OP_Move                                13
-#define OP_Copy                                14
-#define OP_SCopy                               15
-#define OP_ResultRow                           16
-#define OP_Concat                              91   /* same as TK_CONCAT   */
-#define OP_Add                                 86   /* same as TK_PLUS     */
-#define OP_Subtract                            87   /* same as TK_MINUS    */
-#define OP_Multiply                            88   /* same as TK_STAR     */
-#define OP_Divide                              89   /* same as TK_SLASH    */
-#define OP_Remainder                           90   /* same as TK_REM      */
-#define OP_CollSeq                             17
-#define OP_Function                            18
-#define OP_BitAnd                              82   /* same as TK_BITAND   */
-#define OP_BitOr                               83   /* same as TK_BITOR    */
-#define OP_ShiftLeft                           84   /* same as TK_LSHIFT   */
-#define OP_ShiftRight                          85   /* same as TK_RSHIFT   */
-#define OP_AddImm                              20
-#define OP_MustBeInt                           21
-#define OP_RealAffinity                        22
-#define OP_ToText                             141   /* same as TK_TO_TEXT  */
-#define OP_ToBlob                             142   /* same as TK_TO_BLOB  */
-#define OP_ToNumeric                          143   /* same as TK_TO_NUMERIC*/
-#define OP_ToInt                              144   /* same as TK_TO_INT   */
-#define OP_ToReal                             145   /* same as TK_TO_REAL  */
-#define OP_Eq                                  76   /* same as TK_EQ       */
-#define OP_Ne                                  75   /* same as TK_NE       */
-#define OP_Lt                                  79   /* same as TK_LT       */
-#define OP_Le                                  78   /* same as TK_LE       */
-#define OP_Gt                                  77   /* same as TK_GT       */
-#define OP_Ge                                  80   /* same as TK_GE       */
-#define OP_Permutation                         23
-#define OP_Compare                             24
-#define OP_Jump                                25
-#define OP_And                                 69   /* same as TK_AND      */
-#define OP_Or                                  68   /* same as TK_OR       */
-#define OP_Not                                 19   /* same as TK_NOT      */
-#define OP_BitNot                              93   /* same as TK_BITNOT   */
-#define OP_Once                                26
-#define OP_If                                  27
-#define OP_IfNot                               28
-#define OP_IsNull                              73   /* same as TK_ISNULL   */
-#define OP_NotNull                             74   /* same as TK_NOTNULL  */
-#define OP_Column                              29
-#define OP_Affinity                            30
-#define OP_MakeRecord                          31
-#define OP_Count                               32
-#define OP_Savepoint                           33
-#define OP_AutoCommit                          34
-#define OP_Transaction                         35
-#define OP_ReadCookie                          36
-#define OP_SetCookie                           37
-#define OP_VerifyCookie                        38
-#define OP_OpenRead                            39
-#define OP_OpenWrite                           40
-#define OP_OpenAutoindex                       41
-#define OP_OpenEphemeral                       42
-#define OP_SorterOpen                          43
-#define OP_OpenPseudo                          44
-#define OP_Close                               45
-#define OP_SeekLt                              46
-#define OP_SeekLe                              47
-#define OP_SeekGe                              48
-#define OP_SeekGt                              49
-#define OP_Seek                                50
-#define OP_NotFound                            51
-#define OP_Found                               52
-#define OP_IsUnique                            53
-#define OP_NotExists                           54
-#define OP_Sequence                            55
-#define OP_NewRowid                            56
-#define OP_Insert                              57
-#define OP_InsertInt                           58
-#define OP_Delete                              59
-#define OP_ResetCount                          60
-#define OP_SorterCompare                       61
-#define OP_SorterData                          62
-#define OP_RowKey                              63
-#define OP_RowData                             64
-#define OP_Rowid                               65
-#define OP_NullRow                             66
-#define OP_Last                                67
-#define OP_SorterSort                          70
-#define OP_Sort                                71
-#define OP_Rewind                              72
-#define OP_SorterNext                          81
-#define OP_Prev                                92
-#define OP_Next                                95
-#define OP_SorterInsert                        96
-#define OP_IdxInsert                           97
-#define OP_IdxDelete                           98
-#define OP_IdxRowid                            99
-#define OP_IdxLT                              100
-#define OP_IdxGE                              101
-#define OP_Destroy                            102
-#define OP_Clear                              103
-#define OP_CreateIndex                        104
-#define OP_CreateTable                        105
-#define OP_ParseSchema                        106
-#define OP_LoadAnalysis                       107
-#define OP_DropTable                          108
-#define OP_DropIndex                          109
-#define OP_DropTrigger                        110
-#define OP_IntegrityCk                        111
-#define OP_RowSetAdd                          112
-#define OP_RowSetRead                         113
-#define OP_RowSetTest                         114
-#define OP_Program                            115
-#define OP_Param                              116
-#define OP_FkCounter                          117
-#define OP_FkIfZero                           118
-#define OP_MemMax                             119
-#define OP_IfPos                              120
-#define OP_IfNeg                              121
-#define OP_IfZero                             122
-#define OP_AggStep                            123
-#define OP_AggFinal                           124
-#define OP_Checkpoint                         125
-#define OP_JournalMode                        126
-#define OP_Vacuum                             127
-#define OP_IncrVacuum                         128
-#define OP_Expire                             129
-#define OP_TableLock                          131
-#define OP_VBegin                             132
-#define OP_VCreate                            133
-#define OP_VDestroy                           134
-#define OP_VOpen                              135
-#define OP_VFilter                            136
-#define OP_VColumn                            137
-#define OP_VNext                              138
-#define OP_VRename                            139
-#define OP_VUpdate                            140
-#define OP_Pagecount                          146
-#define OP_MaxPgcnt                           147
-#define OP_Trace                              148
-#define OP_Noop                               149
-#define OP_Explain                            150
-
+/* See the tool/mkopcodeh.tcl script for details */
+#define OP_Savepoint       0
+#define OP_AutoCommit      1
+#define OP_Transaction     2
+#define OP_SorterNext      3
+#define OP_PrevIfOpen      4
+#define OP_NextIfOpen      5
+#define OP_Prev            6
+#define OP_Next            7
+#define OP_Checkpoint      8
+#define OP_JournalMode     9
+#define OP_Vacuum         10
+#define OP_VFilter        11 /* synopsis: iplan=r[P3] zplan='P4'           */
+#define OP_VUpdate        12 /* synopsis: data=r[P3@P2]                    */
+#define OP_Goto           13
+#define OP_Gosub          14
+#define OP_InitCoroutine  15
+#define OP_Yield          16
+#define OP_MustBeInt      17
+#define OP_Jump           18
+#define OP_Not            19 /* same as TK_NOT, synopsis: r[P2]= !r[P1]    */
+#define OP_Once           20
+#define OP_If             21
+#define OP_IfNot          22
+#define OP_SeekLT         23 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekLE         24 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekGE         25 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekGT         26 /* synopsis: key=r[P3@P4]                     */
+#define OP_Or             27 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
+#define OP_And            28 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
+#define OP_NoConflict     29 /* synopsis: key=r[P3@P4]                     */
+#define OP_NotFound       30 /* synopsis: key=r[P3@P4]                     */
+#define OP_Found          31 /* synopsis: key=r[P3@P4]                     */
+#define OP_SeekRowid      32 /* synopsis: intkey=r[P3]                     */
+#define OP_NotExists      33 /* synopsis: intkey=r[P3]                     */
+#define OP_IsNull         34 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
+#define OP_NotNull        35 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
+#define OP_Ne             36 /* same as TK_NE, synopsis: if r[P1]!=r[P3] goto P2 */
+#define OP_Eq             37 /* same as TK_EQ, synopsis: if r[P1]==r[P3] goto P2 */
+#define OP_Gt             38 /* same as TK_GT, synopsis: if r[P1]>r[P3] goto P2 */
+#define OP_Le             39 /* same as TK_LE, synopsis: if r[P1]<=r[P3] goto P2 */
+#define OP_Lt             40 /* same as TK_LT, synopsis: if r[P1]<r[P3] goto P2 */
+#define OP_Ge             41 /* same as TK_GE, synopsis: if r[P1]>=r[P3] goto P2 */
+#define OP_Last           42
+#define OP_BitAnd         43 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
+#define OP_BitOr          44 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
+#define OP_ShiftLeft      45 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<<r[P1] */
+#define OP_ShiftRight     46 /* same as TK_RSHIFT, synopsis: r[P3]=r[P2]>>r[P1] */
+#define OP_Add            47 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
+#define OP_Subtract       48 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
+#define OP_Multiply       49 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
+#define OP_Divide         50 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
+#define OP_Remainder      51 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
+#define OP_Concat         52 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
+#define OP_SorterSort     53
+#define OP_BitNot         54 /* same as TK_BITNOT, synopsis: r[P1]= ~r[P1] */
+#define OP_Sort           55
+#define OP_Rewind         56
+#define OP_IdxLE          57 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxGT          58 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxLT          59 /* synopsis: key=r[P3@P4]                     */
+#define OP_IdxGE          60 /* synopsis: key=r[P3@P4]                     */
+#define OP_RowSetRead     61 /* synopsis: r[P3]=rowset(P1)                 */
+#define OP_RowSetTest     62 /* synopsis: if r[P3] in rowset(P1) goto P2   */
+#define OP_Program        63
+#define OP_FkIfZero       64 /* synopsis: if fkctr[P1]==0 goto P2          */
+#define OP_IfPos          65 /* synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
+#define OP_IfNotZero      66 /* synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2 */
+#define OP_DecrJumpZero   67 /* synopsis: if (--r[P1])==0 goto P2          */
+#define OP_IncrVacuum     68
+#define OP_VNext          69
+#define OP_Init           70 /* synopsis: Start at P2                      */
+#define OP_Return         71
+#define OP_EndCoroutine   72
+#define OP_HaltIfNull     73 /* synopsis: if r[P3]=null halt               */
+#define OP_Halt           74
+#define OP_Integer        75 /* synopsis: r[P2]=P1                         */
+#define OP_Int64          76 /* synopsis: r[P2]=P4                         */
+#define OP_String         77 /* synopsis: r[P2]='P4' (len=P1)              */
+#define OP_Null           78 /* synopsis: r[P2..P3]=NULL                   */
+#define OP_SoftNull       79 /* synopsis: r[P1]=NULL                       */
+#define OP_Blob           80 /* synopsis: r[P2]=P4 (len=P1)                */
+#define OP_Variable       81 /* synopsis: r[P2]=parameter(P1,P4)           */
+#define OP_Move           82 /* synopsis: r[P2@P3]=r[P1@P3]                */
+#define OP_Copy           83 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
+#define OP_SCopy          84 /* synopsis: r[P2]=r[P1]                      */
+#define OP_IntCopy        85 /* synopsis: r[P2]=r[P1]                      */
+#define OP_ResultRow      86 /* synopsis: output=r[P1@P2]                  */
+#define OP_CollSeq        87
+#define OP_Function0      88 /* synopsis: r[P3]=func(r[P2@P5])             */
+#define OP_Function       89 /* synopsis: r[P3]=func(r[P2@P5])             */
+#define OP_AddImm         90 /* synopsis: r[P1]=r[P1]+P2                   */
+#define OP_RealAffinity   91
+#define OP_Cast           92 /* synopsis: affinity(r[P1])                  */
+#define OP_Permutation    93
+#define OP_Compare        94 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
+#define OP_Column         95 /* synopsis: r[P3]=PX                         */
+#define OP_Affinity       96 /* synopsis: affinity(r[P1@P2])               */
+#define OP_String8        97 /* same as TK_STRING, synopsis: r[P2]='P4'    */
+#define OP_MakeRecord     98 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
+#define OP_Count          99 /* synopsis: r[P2]=count()                    */
+#define OP_ReadCookie    100
+#define OP_SetCookie     101
+#define OP_ReopenIdx     102 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenRead      103 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenWrite     104 /* synopsis: root=P2 iDb=P3                   */
+#define OP_OpenAutoindex 105 /* synopsis: nColumn=P2                       */
+#define OP_OpenEphemeral 106 /* synopsis: nColumn=P2                       */
+#define OP_SorterOpen    107
+#define OP_SequenceTest  108 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
+#define OP_OpenPseudo    109 /* synopsis: P3 columns in r[P2]              */
+#define OP_Close         110
+#define OP_ColumnsUsed   111
+#define OP_Sequence      112 /* synopsis: r[P2]=cursor[P1].ctr++           */
+#define OP_NewRowid      113 /* synopsis: r[P2]=rowid                      */
+#define OP_Insert        114 /* synopsis: intkey=r[P3] data=r[P2]          */
+#define OP_InsertInt     115 /* synopsis: intkey=P3 data=r[P2]             */
+#define OP_Delete        116
+#define OP_ResetCount    117
+#define OP_SorterCompare 118 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
+#define OP_SorterData    119 /* synopsis: r[P2]=data                       */
+#define OP_RowKey        120 /* synopsis: r[P2]=key                        */
+#define OP_RowData       121 /* synopsis: r[P2]=data                       */
+#define OP_Rowid         122 /* synopsis: r[P2]=rowid                      */
+#define OP_NullRow       123
+#define OP_SorterInsert  124
+#define OP_IdxInsert     125 /* synopsis: key=r[P2]                        */
+#define OP_IdxDelete     126 /* synopsis: key=r[P2@P3]                     */
+#define OP_Seek          127 /* synopsis: Move P3 to P1.rowid              */
+#define OP_IdxRowid      128 /* synopsis: r[P2]=rowid                      */
+#define OP_Destroy       129
+#define OP_Clear         130
+#define OP_ResetSorter   131
+#define OP_CreateIndex   132 /* synopsis: r[P2]=root iDb=P1                */
+#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
+#define OP_CreateTable   134 /* synopsis: r[P2]=root iDb=P1                */
+#define OP_ParseSchema   135
+#define OP_LoadAnalysis  136
+#define OP_DropTable     137
+#define OP_DropIndex     138
+#define OP_DropTrigger   139
+#define OP_IntegrityCk   140
+#define OP_RowSetAdd     141 /* synopsis: rowset(P1)=r[P2]                 */
+#define OP_Param         142
+#define OP_FkCounter     143 /* synopsis: fkctr[P1]+=P2                    */
+#define OP_MemMax        144 /* synopsis: r[P1]=max(r[P1],r[P2])           */
+#define OP_OffsetLimit   145 /* synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1) */
+#define OP_AggStep0      146 /* synopsis: accum=r[P3] step(r[P2@P5])       */
+#define OP_AggStep       147 /* synopsis: accum=r[P3] step(r[P2@P5])       */
+#define OP_AggFinal      148 /* synopsis: accum=r[P1] N=P2                 */
+#define OP_Expire        149
+#define OP_TableLock     150 /* synopsis: iDb=P1 root=P2 write=P3          */
+#define OP_VBegin        151
+#define OP_VCreate       152
+#define OP_VDestroy      153
+#define OP_VOpen         154
+#define OP_VColumn       155 /* synopsis: r[P3]=vcolumn(P2)                */
+#define OP_VRename       156
+#define OP_Pagecount     157
+#define OP_MaxPgcnt      158
+#define OP_CursorHint    159
+#define OP_Noop          160
+#define OP_Explain       161
 
 /* Properties such as "out2" or "jump" that are specified in
 ** comments following the "case" for each opcode in the vdbe.c
 ** are encoded into bitvectors as follows:
 */
-#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */
-#define OPFLG_OUT2_PRERELEASE 0x0002  /* out2-prerelease: */
-#define OPFLG_IN1             0x0004  /* in1:   P1 is an input */
-#define OPFLG_IN2             0x0008  /* in2:   P2 is an input */
-#define OPFLG_IN3             0x0010  /* in3:   P3 is an input */
-#define OPFLG_OUT2            0x0020  /* out2:  P2 is an output */
-#define OPFLG_OUT3            0x0040  /* out3:  P3 is an output */
+#define OPFLG_JUMP        0x01  /* jump:  P2 holds jmp target */
+#define OPFLG_IN1         0x02  /* in1:   P1 is an input */
+#define OPFLG_IN2         0x04  /* in2:   P2 is an input */
+#define OPFLG_IN3         0x08  /* in3:   P3 is an input */
+#define OPFLG_OUT2        0x10  /* out2:  P2 is an output */
+#define OPFLG_OUT3        0x20  /* out3:  P3 is an output */
 #define OPFLG_INITIALIZER {\
-/*   0 */ 0x00, 0x01, 0x05, 0x04, 0x04, 0x10, 0x00, 0x02,\
-/*   8 */ 0x02, 0x02, 0x02, 0x02, 0x02, 0x00, 0x24, 0x24,\
-/*  16 */ 0x00, 0x00, 0x00, 0x24, 0x04, 0x05, 0x04, 0x00,\
-/*  24 */ 0x00, 0x01, 0x05, 0x05, 0x05, 0x00, 0x00, 0x00,\
-/*  32 */ 0x02, 0x00, 0x00, 0x00, 0x02, 0x10, 0x00, 0x00,\
-/*  40 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x11,\
-/*  48 */ 0x11, 0x11, 0x08, 0x11, 0x11, 0x11, 0x11, 0x02,\
-/*  56 */ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
-/*  64 */ 0x00, 0x02, 0x00, 0x01, 0x4c, 0x4c, 0x01, 0x01,\
-/*  72 */ 0x01, 0x05, 0x05, 0x15, 0x15, 0x15, 0x15, 0x15,\
-/*  80 */ 0x15, 0x01, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c, 0x4c,\
-/*  88 */ 0x4c, 0x4c, 0x4c, 0x4c, 0x01, 0x24, 0x02, 0x01,\
-/*  96 */ 0x08, 0x08, 0x00, 0x02, 0x01, 0x01, 0x02, 0x00,\
-/* 104 */ 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
-/* 112 */ 0x0c, 0x45, 0x15, 0x01, 0x02, 0x00, 0x01, 0x08,\
-/* 120 */ 0x05, 0x05, 0x05, 0x00, 0x00, 0x00, 0x02, 0x00,\
-/* 128 */ 0x01, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,\
-/* 136 */ 0x01, 0x00, 0x01, 0x00, 0x00, 0x04, 0x04, 0x04,\
-/* 144 */ 0x04, 0x04, 0x02, 0x02, 0x00, 0x00, 0x00,}
+/*   0 */ 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01,\
+/*   8 */ 0x00, 0x10, 0x00, 0x01, 0x00, 0x01, 0x01, 0x01,\
+/*  16 */ 0x03, 0x03, 0x01, 0x12, 0x01, 0x03, 0x03, 0x09,\
+/*  24 */ 0x09, 0x09, 0x09, 0x26, 0x26, 0x09, 0x09, 0x09,\
+/*  32 */ 0x09, 0x09, 0x03, 0x03, 0x0b, 0x0b, 0x0b, 0x0b,\
+/*  40 */ 0x0b, 0x0b, 0x01, 0x26, 0x26, 0x26, 0x26, 0x26,\
+/*  48 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x01, 0x12, 0x01,\
+/*  56 */ 0x01, 0x01, 0x01, 0x01, 0x01, 0x23, 0x0b, 0x01,\
+/*  64 */ 0x01, 0x03, 0x03, 0x03, 0x01, 0x01, 0x01, 0x02,\
+/*  72 */ 0x02, 0x08, 0x00, 0x10, 0x10, 0x10, 0x10, 0x00,\
+/*  80 */ 0x10, 0x10, 0x00, 0x00, 0x10, 0x10, 0x00, 0x00,\
+/*  88 */ 0x00, 0x00, 0x02, 0x02, 0x02, 0x00, 0x00, 0x00,\
+/*  96 */ 0x00, 0x10, 0x00, 0x10, 0x10, 0x00, 0x00, 0x00,\
+/* 104 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
+/* 112 */ 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
+/* 120 */ 0x00, 0x00, 0x10, 0x00, 0x04, 0x04, 0x00, 0x00,\
+/* 128 */ 0x10, 0x10, 0x00, 0x00, 0x10, 0x10, 0x10, 0x00,\
+/* 136 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x10, 0x00,\
+/* 144 */ 0x04, 0x1a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
+/* 152 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x10, 0x00,\
+/* 160 */ 0x00, 0x00,}
+
+/* The sqlite3P2Values() routine is able to run faster if it knows
+** the value of the largest JUMP opcode.  The smaller the maximum
+** JUMP opcode the better, so the mkopcodeh.tcl script that
+** generated this include file strives to group all JUMP opcodes
+** together near the beginning of the list.
+*/
+#define SQLITE_MX_JUMP_OPCODE  70  /* Maximum JUMP opcode */
 
 /************** End of opcodes.h *********************************************/
 /************** Continuing where we left off in vdbe.h ***********************/
@@ -8558,35 +12736,48 @@ typedef struct VdbeOpList VdbeOpList;
 ** Prototypes for the VDBE interface.  See comments on the implementation
 ** for a description of what each of these routines does.
 */
-SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(sqlite3*);
+SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse*);
 SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe*,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
+SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe*,int);
+SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe*,int,const char*);
+SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
 SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
+SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
-SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
+SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe*,int);
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
+SQLITE_PRIVATE   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
+#else
+# define sqlite3VdbeVerifyNoMallocRequired(A,B)
+#endif
+SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
 SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
+SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
 SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
 SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
-SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
+SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
+SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
 SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
+SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
 SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
 SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*);
+SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*);
-SQLITE_PRIVATE void sqlite3VdbeDeleteObject(sqlite3*,Vdbe*);
+SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe*, int);
 SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*);
 #ifdef SQLITE_DEBUG
 SQLITE_PRIVATE   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
-SQLITE_PRIVATE   void sqlite3VdbeTrace(Vdbe*,FILE*);
 #endif
 SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe*);
@@ -8598,33 +12789,93 @@ SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);
 SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
 SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
-SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetValue(Vdbe*, int, u8);
+SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
 SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe*, int);
 #ifndef SQLITE_OMIT_TRACE
 SQLITE_PRIVATE   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
 #endif
+SQLITE_PRIVATE int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
 
 SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 SQLITE_PRIVATE int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
+SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
 SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);
 
+typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
+SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
+
 #ifndef SQLITE_OMIT_TRIGGER
 SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 #endif
 
-
-#ifndef NDEBUG
+/* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
+** each VDBE opcode.
+**
+** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
+** comments in VDBE programs that show key decision points in the code
+** generator.
+*/
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
 SQLITE_PRIVATE   void sqlite3VdbeComment(Vdbe*, const char*, ...);
 # define VdbeComment(X)  sqlite3VdbeComment X
 SQLITE_PRIVATE   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
+# ifdef SQLITE_ENABLE_MODULE_COMMENTS
+#   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
+# else
+#   define VdbeModuleComment(X)
+# endif
 #else
 # define VdbeComment(X)
 # define VdbeNoopComment(X)
+# define VdbeModuleComment(X)
 #endif
 
+/*
+** The VdbeCoverage macros are used to set a coverage testing point
+** for VDBE branch instructions.  The coverage testing points are line
+** numbers in the sqlite3.c source file.  VDBE branch coverage testing
+** only works with an amalagmation build.  That's ok since a VDBE branch
+** coverage build designed for testing the test suite only.  No application
+** should ever ship with VDBE branch coverage measuring turned on.
+**
+**    VdbeCoverage(v)                  // Mark the previously coded instruction
+**                                     // as a branch
+**
+**    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
+**
+**    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
+**
+**    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
+**
+** Every VDBE branch operation must be tagged with one of the macros above.
+** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
+** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
+** routine in vdbe.c, alerting the developer to the missed tag.
+*/
+#ifdef SQLITE_VDBE_COVERAGE
+SQLITE_PRIVATE   void sqlite3VdbeSetLineNumber(Vdbe*,int);
+# define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
+# define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
+# define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
+# define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
+# define VDBE_OFFSET_LINENO(x) (__LINE__+x)
+#else
+# define VdbeCoverage(v)
+# define VdbeCoverageIf(v,x)
+# define VdbeCoverageAlwaysTaken(v)
+# define VdbeCoverageNeverTaken(v)
+# define VDBE_OFFSET_LINENO(x) 0
+#endif
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+SQLITE_PRIVATE void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
+#else
+# define sqlite3VdbeScanStatus(a,b,c,d,e)
 #endif
 
+#endif /* SQLITE_VDBE_H */
+
 /************** End of vdbe.h ************************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
 /************** Include pager.h in the middle of sqliteInt.h *****************/
@@ -8645,8 +12896,8 @@ SQLITE_PRIVATE   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 ** at a time and provides a journal for rollback.
 */
 
-#ifndef _PAGER_H_
-#define _PAGER_H_
+#ifndef SQLITE_PAGER_H
+#define SQLITE_PAGER_H
 
 /*
 ** Default maximum size for persistent journal files. A negative 
@@ -8689,8 +12940,7 @@ typedef struct PgHdr DbPage;
 ** NOTE: These values must match the corresponding BTREE_ values in btree.h.
 */
 #define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
-#define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
-#define PAGER_MEMORY        0x0004    /* In-memory database */
+#define PAGER_MEMORY        0x0002    /* In-memory database */
 
 /*
 ** Valid values for the second argument to sqlite3PagerLockingMode().
@@ -8700,7 +12950,11 @@ typedef struct PgHdr DbPage;
 #define PAGER_LOCKINGMODE_EXCLUSIVE   1
 
 /*
-** Numeric constants that encode the journalmode.  
+** Numeric constants that encode the journalmode.
+**
+** The numeric values encoded here (other than PAGER_JOURNALMODE_QUERY)
+** are exposed in the API via the "PRAGMA journal_mode" command and
+** therefore cannot be changed without a compatibility break.
 */
 #define PAGER_JOURNALMODE_QUERY     (-1)  /* Query the value of journalmode */
 #define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */
@@ -8711,6 +12965,30 @@ typedef struct PgHdr DbPage;
 #define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */
 
 /*
+** Flags that make up the mask passed to sqlite3PagerGet().
+*/
+#define PAGER_GET_NOCONTENT     0x01  /* Do not load data from disk */
+#define PAGER_GET_READONLY      0x02  /* Read-only page is acceptable */
+
+/*
+** Flags for sqlite3PagerSetFlags()
+**
+** Value constraints (enforced via assert()):
+**    PAGER_FULLFSYNC      == SQLITE_FullFSync
+**    PAGER_CKPT_FULLFSYNC == SQLITE_CkptFullFSync
+**    PAGER_CACHE_SPILL    == SQLITE_CacheSpill
+*/
+#define PAGER_SYNCHRONOUS_OFF       0x01  /* PRAGMA synchronous=OFF */
+#define PAGER_SYNCHRONOUS_NORMAL    0x02  /* PRAGMA synchronous=NORMAL */
+#define PAGER_SYNCHRONOUS_FULL      0x03  /* PRAGMA synchronous=FULL */
+#define PAGER_SYNCHRONOUS_EXTRA     0x04  /* PRAGMA synchronous=EXTRA */
+#define PAGER_SYNCHRONOUS_MASK      0x07  /* Mask for four values above */
+#define PAGER_FULLFSYNC             0x08  /* PRAGMA fullfsync=ON */
+#define PAGER_CKPT_FULLFSYNC        0x10  /* PRAGMA checkpoint_fullfsync=ON */
+#define PAGER_CACHESPILL            0x20  /* PRAGMA cache_spill=ON */
+#define PAGER_FLAGS_MASK            0x38  /* All above except SYNCHRONOUS */
+
+/*
 ** The remainder of this file contains the declarations of the functions
 ** that make up the Pager sub-system API. See source code comments for 
 ** a detailed description of each routine.
@@ -8732,22 +13010,29 @@ SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
 /* Functions used to configure a Pager object. */
 SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(Pager*, int(*)(void *), void *);
 SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u32*, int);
+#ifdef SQLITE_HAS_CODEC
+SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager*,Pager*);
+#endif
 SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int);
 SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);
-SQLITE_PRIVATE void sqlite3PagerSetSafetyLevel(Pager*,int,int,int);
+SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager*, int);
+SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
+SQLITE_PRIVATE void sqlite3PagerShrink(Pager*);
+SQLITE_PRIVATE void sqlite3PagerSetFlags(Pager*,unsigned);
 SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *, int);
 SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *, int);
 SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager*);
 SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager*);
 SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
 SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
+SQLITE_PRIVATE int sqlite3PagerFlush(Pager*);
 
 /* Functions used to obtain and release page references. */ 
-SQLITE_PRIVATE int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
-#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
+SQLITE_PRIVATE int sqlite3PagerGet(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
 SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
 SQLITE_PRIVATE void sqlite3PagerRef(DbPage*);
 SQLITE_PRIVATE void sqlite3PagerUnref(DbPage*);
+SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage*);
 
 /* Operations on page references. */
 SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*);
@@ -8762,36 +13047,52 @@ SQLITE_PRIVATE void sqlite3PagerPagecount(Pager*, int*);
 SQLITE_PRIVATE int sqlite3PagerBegin(Pager*, int exFlag, int);
 SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);
 SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager*);
-SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager);
+SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zMaster);
 SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*);
 SQLITE_PRIVATE int sqlite3PagerRollback(Pager*);
 SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
 SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
 SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager);
 
-SQLITE_PRIVATE int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*);
-SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager);
-SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager);
-SQLITE_PRIVATE int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
-SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager);
+#ifndef SQLITE_OMIT_WAL
+SQLITE_PRIVATE   int sqlite3PagerCheckpoint(Pager *pPager, int, int*, int*);
+SQLITE_PRIVATE   int sqlite3PagerWalSupported(Pager *pPager);
+SQLITE_PRIVATE   int sqlite3PagerWalCallback(Pager *pPager);
+SQLITE_PRIVATE   int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
+SQLITE_PRIVATE   int sqlite3PagerCloseWal(Pager *pPager);
+# ifdef SQLITE_ENABLE_SNAPSHOT
+SQLITE_PRIVATE   int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot);
+SQLITE_PRIVATE   int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot);
+# endif
+#endif
+
+#ifdef SQLITE_ENABLE_ZIPVFS
+SQLITE_PRIVATE   int sqlite3PagerWalFramesize(Pager *pPager);
+#endif
 
 /* Functions used to query pager state and configuration. */
 SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager*);
-SQLITE_PRIVATE int sqlite3PagerRefcount(Pager*);
+SQLITE_PRIVATE u32 sqlite3PagerDataVersion(Pager*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE   int sqlite3PagerRefcount(Pager*);
+#endif
 SQLITE_PRIVATE int sqlite3PagerMemUsed(Pager*);
-SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*);
-SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager*);
+SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*, int);
+SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager*);
 SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*);
+SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager*);
 SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*);
-SQLITE_PRIVATE int sqlite3PagerNosync(Pager*);
 SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*);
 SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager*);
 SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *, int, int, int *);
-SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *);
+SQLITE_PRIVATE void sqlite3PagerClearCache(Pager*);
+SQLITE_PRIVATE int sqlite3SectorSize(sqlite3_file *);
 
 /* Functions used to truncate the database file. */
 SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager*,Pgno);
 
+SQLITE_PRIVATE void sqlite3PagerRekey(DbPage*, Pgno, u16);
+
 #if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL)
 SQLITE_PRIVATE void *sqlite3PagerCodec(DbPage *);
 #endif
@@ -8811,7 +13112,7 @@ SQLITE_PRIVATE   void sqlite3PagerRefdump(Pager*);
 # define enable_simulated_io_errors()
 #endif
 
-#endif /* _PAGER_H_ */
+#endif /* SQLITE_PAGER_H */
 
 /************** End of pager.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
@@ -8842,11 +13143,12 @@ typedef struct PCache PCache;
 ** structure.
 */
 struct PgHdr {
-  void *pData;                   /* Content of this page */
+  sqlite3_pcache_page *pPage;    /* Pcache object page handle */
+  void *pData;                   /* Page data */
   void *pExtra;                  /* Extra content */
-  PgHdr *pDirty;                 /* Transient list of dirty pages */
-  Pgno pgno;                     /* Page number for this page */
+  PgHdr *pDirty;                 /* Transient list of dirty sorted by pgno */
   Pager *pPager;                 /* The pager this page is part of */
+  Pgno pgno;                     /* Page number for this page */
 #ifdef SQLITE_CHECK_PAGES
   u32 pageHash;                  /* Hash of page content */
 #endif
@@ -8864,12 +13166,15 @@ struct PgHdr {
 };
 
 /* Bit values for PgHdr.flags */
-#define PGHDR_DIRTY             0x002  /* Page has changed */
-#define PGHDR_NEED_SYNC         0x004  /* Fsync the rollback journal before
-                                       ** writing this page to the database */
-#define PGHDR_NEED_READ         0x008  /* Content is unread */
-#define PGHDR_REUSE_UNLIKELY    0x010  /* A hint that reuse is unlikely */
-#define PGHDR_DONT_WRITE        0x020  /* Do not write content to disk */
+#define PGHDR_CLEAN           0x001  /* Page not on the PCache.pDirty list */
+#define PGHDR_DIRTY           0x002  /* Page is on the PCache.pDirty list */
+#define PGHDR_WRITEABLE       0x004  /* Journaled and ready to modify */
+#define PGHDR_NEED_SYNC       0x008  /* Fsync the rollback journal before
+                                     ** writing this page to the database */
+#define PGHDR_DONT_WRITE      0x010  /* Do not write content to disk */
+#define PGHDR_MMAP            0x020  /* This is an mmap page object */
+
+#define PGHDR_WAL_APPEND      0x040  /* Appended to wal file */
 
 /* Initialize and shutdown the page cache subsystem */
 SQLITE_PRIVATE int sqlite3PcacheInitialize(void);
@@ -8884,7 +13189,7 @@ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *, int sz, int n);
 ** Under memory stress, invoke xStress to try to make pages clean.
 ** Only clean and unpinned pages can be reclaimed.
 */
-SQLITE_PRIVATE void sqlite3PcacheOpen(
+SQLITE_PRIVATE int sqlite3PcacheOpen(
   int szPage,                    /* Size of every page */
   int szExtra,                   /* Extra space associated with each page */
   int bPurgeable,                /* True if pages are on backing store */
@@ -8894,7 +13199,7 @@ SQLITE_PRIVATE void sqlite3PcacheOpen(
 );
 
 /* Modify the page-size after the cache has been created. */
-SQLITE_PRIVATE void sqlite3PcacheSetPageSize(PCache *, int);
+SQLITE_PRIVATE int sqlite3PcacheSetPageSize(PCache *, int);
 
 /* Return the size in bytes of a PCache object.  Used to preallocate
 ** storage space.
@@ -8904,13 +13209,16 @@ SQLITE_PRIVATE int sqlite3PcacheSize(void);
 /* One release per successful fetch.  Page is pinned until released.
 ** Reference counted. 
 */
-SQLITE_PRIVATE int sqlite3PcacheFetch(PCache*, Pgno, int createFlag, PgHdr**);
+SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(PCache*, Pgno, int createFlag);
+SQLITE_PRIVATE int sqlite3PcacheFetchStress(PCache*, Pgno, sqlite3_pcache_page**);
+SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(PCache*, Pgno, sqlite3_pcache_page *pPage);
 SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr*);
 
 SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr*);         /* Remove page from cache */
 SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr*);    /* Make sure page is marked dirty */
 SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr*);    /* Mark a single page as clean */
 SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache*);    /* Mark all dirty list pages as clean */
+SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache*);
 
 /* Change a page number.  Used by incr-vacuum. */
 SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr*, Pgno);
@@ -8949,6 +13257,11 @@ SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*);
 SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *));
 #endif
 
+#if defined(SQLITE_DEBUG)
+/* Check invariants on a PgHdr object */
+SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr*);
+#endif
+
 /* Set and get the suggested cache-size for the specified pager-cache.
 **
 ** If no global maximum is configured, then the system attempts to limit
@@ -8960,6 +13273,16 @@ SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *, int);
 SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *);
 #endif
 
+/* Set or get the suggested spill-size for the specified pager-cache.
+**
+** The spill-size is the minimum number of pages in cache before the cache
+** will attempt to spill dirty pages by calling xStress.
+*/
+SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *, int);
+
+/* Free up as much memory as possible from the page cache */
+SQLITE_PRIVATE void sqlite3PcacheShrink(PCache*);
+
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
 /* Try to return memory used by the pcache module to the main memory heap */
 SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int);
@@ -8971,11 +13294,17 @@ SQLITE_PRIVATE void sqlite3PcacheStats(int*,int*,int*,int*);
 
 SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);
 
+/* Return the header size */
+SQLITE_PRIVATE int sqlite3HeaderSizePcache(void);
+SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void);
+
+/* Number of dirty pages as a percentage of the configured cache size */
+SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache*);
+
 #endif /* _PCACHE_H_ */
 
 /************** End of pcache.h **********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
-
 /************** Include os.h in the middle of sqliteInt.h ********************/
 /************** Begin file os.h **********************************************/
 /*
@@ -9001,84 +13330,71 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);
 #define _SQLITE_OS_H_
 
 /*
-** Figure out if we are dealing with Unix, Windows, or some other
-** operating system.  After the following block of preprocess macros,
-** all of SQLITE_OS_UNIX, SQLITE_OS_WIN, SQLITE_OS_OS2, and SQLITE_OS_OTHER 
-** will defined to either 1 or 0.  One of the four will be 1.  The other 
-** three will be 0.
+** Attempt to automatically detect the operating system and setup the
+** necessary pre-processor macros for it.
+*/
+/************** Include os_setup.h in the middle of os.h *********************/
+/************** Begin file os_setup.h ****************************************/
+/*
+** 2013 November 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains pre-processor directives related to operating system
+** detection and/or setup.
+*/
+#ifndef SQLITE_OS_SETUP_H
+#define SQLITE_OS_SETUP_H
+
+/*
+** Figure out if we are dealing with Unix, Windows, or some other operating
+** system.
+**
+** After the following block of preprocess macros, all of SQLITE_OS_UNIX,
+** SQLITE_OS_WIN, and SQLITE_OS_OTHER will defined to either 1 or 0.  One of
+** the three will be 1.  The other two will be 0.
 */
 #if defined(SQLITE_OS_OTHER)
-# if SQLITE_OS_OTHER==1
-#   undef SQLITE_OS_UNIX
-#   define SQLITE_OS_UNIX 0
-#   undef SQLITE_OS_WIN
-#   define SQLITE_OS_WIN 0
-#   undef SQLITE_OS_OS2
-#   define SQLITE_OS_OS2 0
-# else
-#   undef SQLITE_OS_OTHER
-# endif
+#  if SQLITE_OS_OTHER==1
+#    undef SQLITE_OS_UNIX
+#    define SQLITE_OS_UNIX 0
+#    undef SQLITE_OS_WIN
+#    define SQLITE_OS_WIN 0
+#  else
+#    undef SQLITE_OS_OTHER
+#  endif
 #endif
 #if !defined(SQLITE_OS_UNIX) && !defined(SQLITE_OS_OTHER)
-# define SQLITE_OS_OTHER 0
-# ifndef SQLITE_OS_WIN
-#   if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__)
-#     define SQLITE_OS_WIN 1
-#     define SQLITE_OS_UNIX 0
-#     define SQLITE_OS_OS2 0
-#   elif defined(__EMX__) || defined(_OS2) || defined(OS2) || defined(_OS2_) || defined(__OS2__)
-#     define SQLITE_OS_WIN 0
-#     define SQLITE_OS_UNIX 0
-#     define SQLITE_OS_OS2 1
-#   else
-#     define SQLITE_OS_WIN 0
-#     define SQLITE_OS_UNIX 1
-#     define SQLITE_OS_OS2 0
+#  define SQLITE_OS_OTHER 0
+#  ifndef SQLITE_OS_WIN
+#    if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || \
+        defined(__MINGW32__) || defined(__BORLANDC__)
+#      define SQLITE_OS_WIN 1
+#      define SQLITE_OS_UNIX 0
+#    else
+#      define SQLITE_OS_WIN 0
+#      define SQLITE_OS_UNIX 1
+#    endif
+#  else
+#    define SQLITE_OS_UNIX 0
 #  endif
-# else
-#  define SQLITE_OS_UNIX 0
-#  define SQLITE_OS_OS2 0
-# endif
 #else
-# ifndef SQLITE_OS_WIN
-#  define SQLITE_OS_WIN 0
-# endif
-#endif
-
-/*
-** Determine if we are dealing with WindowsCE - which has a much
-** reduced API.
-*/
-#if defined(_WIN32_WCE)
-# define SQLITE_OS_WINCE 1
-#else
-# define SQLITE_OS_WINCE 0
+#  ifndef SQLITE_OS_WIN
+#    define SQLITE_OS_WIN 0
+#  endif
 #endif
 
+#endif /* SQLITE_OS_SETUP_H */
 
-/*
-** Define the maximum size of a temporary filename
-*/
-#if SQLITE_OS_WIN
-# include <windows.h>
-# define SQLITE_TEMPNAME_SIZE (MAX_PATH+50)
-#elif SQLITE_OS_OS2
-# if (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3) && defined(OS2_HIGH_MEMORY)
-#  include <os2safe.h> /* has to be included before os2.h for linking to work */
-# endif
-# define INCL_DOSDATETIME
-# define INCL_DOSFILEMGR
-# define INCL_DOSERRORS
-# define INCL_DOSMISC
-# define INCL_DOSPROCESS
-# define INCL_DOSMODULEMGR
-# define INCL_DOSSEMAPHORES
-# include <os2.h>
-# include <uconv.h>
-# define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP)
-#else
-# define SQLITE_TEMPNAME_SIZE 200
-#endif
+/************** End of os_setup.h ********************************************/
+/************** Continuing where we left off in os.h *************************/
 
 /* If the SET_FULLSYNC macro is not defined above, then make it
 ** a no-op
@@ -9091,7 +13407,7 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);
 ** The default size of a disk sector
 */
 #ifndef SQLITE_DEFAULT_SECTOR_SIZE
-# define SQLITE_DEFAULT_SECTOR_SIZE 512
+# define SQLITE_DEFAULT_SECTOR_SIZE 4096
 #endif
 
 /*
@@ -9174,7 +13490,7 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);
 ** shared locks begins at SHARED_FIRST. 
 **
 ** The same locking strategy and
-** byte ranges are used for Unix.  This leaves open the possiblity of having
+** byte ranges are used for Unix.  This leaves open the possibility of having
 ** clients on win95, winNT, and unix all talking to the same shared file
 ** and all locking correctly.  To do so would require that samba (or whatever
 ** tool is being used for file sharing) implements locks correctly between
@@ -9214,7 +13530,7 @@ SQLITE_PRIVATE int sqlite3OsInit(void);
 /* 
 ** Functions for accessing sqlite3_file methods 
 */
-SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file*);
+SQLITE_PRIVATE void sqlite3OsClose(sqlite3_file*);
 SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);
 SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);
 SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file*, i64 size);
@@ -9224,6 +13540,7 @@ SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file*, int);
 SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file*, int);
 SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut);
 SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file*,int,void*);
+SQLITE_PRIVATE void sqlite3OsFileControlHint(sqlite3_file*,int,void*);
 #define SQLITE_FCNTL_DB_UNCHANGED 0xca093fa0
 SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id);
 SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id);
@@ -9231,6 +13548,9 @@ SQLITE_PRIVATE int sqlite3OsShmMap(sqlite3_file *,int,int,int,void volatile **);
 SQLITE_PRIVATE int sqlite3OsShmLock(sqlite3_file *id, int, int, int);
 SQLITE_PRIVATE void sqlite3OsShmBarrier(sqlite3_file *id);
 SQLITE_PRIVATE int sqlite3OsShmUnmap(sqlite3_file *id, int);
+SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64, int, void **);
+SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *, i64, void *);
+
 
 /* 
 ** Functions for accessing sqlite3_vfs methods 
@@ -9247,6 +13567,7 @@ SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *, void *);
 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
 SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *, int);
+SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs*);
 SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*);
 
 /*
@@ -9254,7 +13575,7 @@ SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*);
 ** sqlite3_malloc() to obtain space for the file-handle structure.
 */
 SQLITE_PRIVATE int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);
-SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
+SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *);
 
 #endif /* _SQLITE_OS_H_ */
 
@@ -9289,7 +13610,7 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 ** Figure out what version of the code to use.  The choices are
 **
 **   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The
-**                             mutexes implemention cannot be overridden
+**                             mutexes implementation cannot be overridden
 **                             at start-time.
 **
 **   SQLITE_MUTEX_NOOP         For single-threaded applications.  No
@@ -9300,8 +13621,6 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 **   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
 **
 **   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
-**
-**   SQLITE_MUTEX_OS2          For multi-threaded applications on OS/2.
 */
 #if !SQLITE_THREADSAFE
 # define SQLITE_MUTEX_OMIT
@@ -9311,8 +13630,6 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 #    define SQLITE_MUTEX_PTHREADS
 #  elif SQLITE_OS_WIN
 #    define SQLITE_MUTEX_W32
-#  elif SQLITE_OS_OS2
-#    define SQLITE_MUTEX_OS2
 #  else
 #    define SQLITE_MUTEX_NOOP
 #  endif
@@ -9340,6 +13657,36 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 /************** End of mutex.h ***********************************************/
 /************** Continuing where we left off in sqliteInt.h ******************/
 
+/* The SQLITE_EXTRA_DURABLE compile-time option used to set the default
+** synchronous setting to EXTRA.  It is no longer supported.
+*/
+#ifdef SQLITE_EXTRA_DURABLE
+# warning Use SQLITE_DEFAULT_SYNCHRONOUS=3 instead of SQLITE_EXTRA_DURABLE
+# define SQLITE_DEFAULT_SYNCHRONOUS 3
+#endif
+
+/*
+** Default synchronous levels.
+**
+** Note that (for historcal reasons) the PAGER_SYNCHRONOUS_* macros differ
+** from the SQLITE_DEFAULT_SYNCHRONOUS value by 1.
+**
+**           PAGER_SYNCHRONOUS       DEFAULT_SYNCHRONOUS
+**   OFF           1                         0
+**   NORMAL        2                         1
+**   FULL          3                         2
+**   EXTRA         4                         3
+**
+** The "PRAGMA synchronous" statement also uses the zero-based numbers.
+** In other words, the zero-based numbers are used for all external interfaces
+** and the one-based values are used internally.
+*/
+#ifndef SQLITE_DEFAULT_SYNCHRONOUS
+# define SQLITE_DEFAULT_SYNCHRONOUS (PAGER_SYNCHRONOUS_FULL-1)
+#endif
+#ifndef SQLITE_DEFAULT_WAL_SYNCHRONOUS
+# define SQLITE_DEFAULT_WAL_SYNCHRONOUS SQLITE_DEFAULT_SYNCHRONOUS
+#endif
 
 /*
 ** Each database file to be accessed by the system is an instance
@@ -9351,8 +13698,8 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *);
 struct Db {
   char *zName;         /* Name of this database */
   Btree *pBt;          /* The B*Tree structure for this database file */
-  u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
   u8 safety_level;     /* How aggressive at syncing data to disk */
+  u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */
   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
 };
 
@@ -9363,7 +13710,7 @@ struct Db {
 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
 ** In shared cache mode, a single Schema object can be shared by multiple
 ** Btrees that refer to the same underlying BtShared object.
-** 
+**
 ** Schema objects are automatically deallocated when the last Btree that
 ** references them is destroyed.   The TEMP Schema is manually freed by
 ** sqlite3_close().
@@ -9383,18 +13730,18 @@ struct Schema {
   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
   u8 file_format;      /* Schema format version for this file */
   u8 enc;              /* Text encoding used by this database */
-  u16 flags;           /* Flags associated with this schema */
+  u16 schemaFlags;     /* Flags associated with this schema */
   int cache_size;      /* Number of pages to use in the cache */
 };
 
 /*
-** These macros can be used to test, set, or clear bits in the 
+** These macros can be used to test, set, or clear bits in the
 ** Db.pSchema->flags field.
 */
-#define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
-#define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
-#define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
-#define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
+#define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->schemaFlags&(P))==(P))
+#define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->schemaFlags&(P))!=0)
+#define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->schemaFlags|=(P)
+#define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->schemaFlags&=~(P)
 
 /*
 ** Allowed values for the DB.pSchema->flags field.
@@ -9414,7 +13761,7 @@ struct Schema {
 ** The number of different kinds of things that can be limited
 ** using the sqlite3_limit() interface.
 */
-#define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
+#define SQLITE_N_LIMIT (SQLITE_LIMIT_WORKER_THREADS+1)
 
 /*
 ** Lookaside malloc is a set of fixed-size buffers that can be used
@@ -9437,8 +13784,8 @@ struct Schema {
 ** lookaside allocations are not used to construct the schema objects.
 */
 struct Lookaside {
+  u32 bDisable;           /* Only operate the lookaside when zero */
   u16 sz;                 /* Size of each buffer in bytes */
-  u8 bEnabled;            /* False to disable new lookaside allocations */
   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
   int nOut;               /* Number of buffers currently checked out */
   int mxOut;              /* Highwater mark for nOut */
@@ -9452,87 +13799,131 @@ struct LookasideSlot {
 };
 
 /*
-** A hash table for function definitions.
+** A hash table for built-in function definitions.  (Application-defined
+** functions use a regular table table from hash.h.)
 **
 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
-** Collisions are on the FuncDef.pHash chain.
+** Collisions are on the FuncDef.u.pHash chain.
 */
+#define SQLITE_FUNC_HASH_SZ 23
 struct FuncDefHash {
-  FuncDef *a[23];       /* Hash table for functions */
+  FuncDef *a[SQLITE_FUNC_HASH_SZ];       /* Hash table for functions */
+};
+
+#ifdef SQLITE_USER_AUTHENTICATION
+/*
+** Information held in the "sqlite3" database connection object and used
+** to manage user authentication.
+*/
+typedef struct sqlite3_userauth sqlite3_userauth;
+struct sqlite3_userauth {
+  u8 authLevel;                 /* Current authentication level */
+  int nAuthPW;                  /* Size of the zAuthPW in bytes */
+  char *zAuthPW;                /* Password used to authenticate */
+  char *zAuthUser;              /* User name used to authenticate */
 };
 
+/* Allowed values for sqlite3_userauth.authLevel */
+#define UAUTH_Unknown     0     /* Authentication not yet checked */
+#define UAUTH_Fail        1     /* User authentication failed */
+#define UAUTH_User        2     /* Authenticated as a normal user */
+#define UAUTH_Admin       3     /* Authenticated as an administrator */
+
+/* Functions used only by user authorization logic */
+SQLITE_PRIVATE int sqlite3UserAuthTable(const char*);
+SQLITE_PRIVATE int sqlite3UserAuthCheckLogin(sqlite3*,const char*,u8*);
+SQLITE_PRIVATE void sqlite3UserAuthInit(sqlite3*);
+SQLITE_PRIVATE void sqlite3CryptFunc(sqlite3_context*,int,sqlite3_value**);
+
+#endif /* SQLITE_USER_AUTHENTICATION */
+
+/*
+** typedef for the authorization callback function.
+*/
+#ifdef SQLITE_USER_AUTHENTICATION
+  typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
+                               const char*, const char*);
+#else
+  typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
+                               const char*);
+#endif
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/* This is an extra SQLITE_TRACE macro that indicates "legacy" tracing
+** in the style of sqlite3_trace()
+*/
+#define SQLITE_TRACE_LEGACY  0x80
+#else
+#define SQLITE_TRACE_LEGACY  0
+#endif /* SQLITE_OMIT_DEPRECATED */
+
+
 /*
 ** Each database connection is an instance of the following structure.
-**
-** The sqlite.lastRowid records the last insert rowid generated by an
-** insert statement.  Inserts on views do not affect its value.  Each
-** trigger has its own context, so that lastRowid can be updated inside
-** triggers as usual.  The previous value will be restored once the trigger
-** exits.  Upon entering a before or instead of trigger, lastRowid is no
-** longer (since after version 2.8.12) reset to -1.
-**
-** The sqlite.nChange does not count changes within triggers and keeps no
-** context.  It is reset at start of sqlite3_exec.
-** The sqlite.lsChange represents the number of changes made by the last
-** insert, update, or delete statement.  It remains constant throughout the
-** length of a statement and is then updated by OP_SetCounts.  It keeps a
-** context stack just like lastRowid so that the count of changes
-** within a trigger is not seen outside the trigger.  Changes to views do not
-** affect the value of lsChange.
-** The sqlite.csChange keeps track of the number of current changes (since
-** the last statement) and is used to update sqlite_lsChange.
-**
-** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
-** store the most recent error code and, if applicable, string. The
-** internal function sqlite3Error() is used to set these variables
-** consistently.
 */
 struct sqlite3 {
   sqlite3_vfs *pVfs;            /* OS Interface */
-  int nDb;                      /* Number of backends currently in use */
+  struct Vdbe *pVdbe;           /* List of active virtual machines */
+  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
+  sqlite3_mutex *mutex;         /* Connection mutex */
   Db *aDb;                      /* All backends */
+  int nDb;                      /* Number of backends currently in use */
   int flags;                    /* Miscellaneous flags. See below */
+  i64 lastRowid;                /* ROWID of most recent insert (see above) */
+  i64 szMmap;                   /* Default mmap_size setting */
   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
   int errCode;                  /* Most recent error code (SQLITE_*) */
   int errMask;                  /* & result codes with this before returning */
+  int iSysErrno;                /* Errno value from last system error */
+  u16 dbOptFlags;               /* Flags to enable/disable optimizations */
+  u8 enc;                       /* Text encoding */
   u8 autoCommit;                /* The auto-commit flag. */
   u8 temp_store;                /* 1: file 2: memory 0: default */
   u8 mallocFailed;              /* True if we have seen a malloc failure */
+  u8 bBenignMalloc;             /* Do not require OOMs if true */
   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
   u8 suppressErr;               /* Do not issue error messages if true */
   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
+  u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
+  u8 mTrace;                    /* zero or more SQLITE_TRACE flags */
   int nextPagesize;             /* Pagesize after VACUUM if >0 */
-  int nTable;                   /* Number of tables in the database */
-  CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
-  i64 lastRowid;                /* ROWID of most recent insert (see above) */
   u32 magic;                    /* Magic number for detect library misuse */
   int nChange;                  /* Value returned by sqlite3_changes() */
   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
-  sqlite3_mutex *mutex;         /* Connection mutex */
   int aLimit[SQLITE_N_LIMIT];   /* Limits */
+  int nMaxSorterMmap;           /* Maximum size of regions mapped by sorter */
   struct sqlite3InitInfo {      /* Information used during initialization */
-    int iDb;                    /* When back is being initialized */
     int newTnum;                /* Rootpage of table being initialized */
+    u8 iDb;                     /* Which db file is being initialized */
     u8 busy;                    /* TRUE if currently initializing */
     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
+    u8 imposterTable;           /* Building an imposter table */
   } init;
+  int nVdbeActive;              /* Number of VDBEs currently running */
+  int nVdbeRead;                /* Number of active VDBEs that read or write */
+  int nVdbeWrite;               /* Number of active VDBEs that read and write */
+  int nVdbeExec;                /* Number of nested calls to VdbeExec() */
+  int nVDestroy;                /* Number of active OP_VDestroy operations */
   int nExtension;               /* Number of loaded extensions */
   void **aExtension;            /* Array of shared library handles */
-  struct Vdbe *pVdbe;           /* List of active virtual machines */
-  int activeVdbeCnt;            /* Number of VDBEs currently executing */
-  int writeVdbeCnt;             /* Number of active VDBEs that are writing */
-  int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
-  void (*xTrace)(void*,const char*);        /* Trace function */
+  int (*xTrace)(u32,void*,void*,void*);     /* Trace function */
   void *pTraceArg;                          /* Argument to the trace function */
   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
   void *pProfileArg;                        /* Argument to profile function */
-  void *pCommitArg;                 /* Argument to xCommitCallback() */   
+  void *pCommitArg;                 /* Argument to xCommitCallback() */
   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
-  void *pRollbackArg;               /* Argument to xRollbackCallback() */   
+  void *pRollbackArg;               /* Argument to xRollbackCallback() */
   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
   void *pUpdateArg;
   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  void *pPreUpdateArg;          /* First argument to xPreUpdateCallback */
+  void (*xPreUpdateCallback)(   /* Registered using sqlite3_preupdate_hook() */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64
+  );
+  PreUpdate *pPreUpdate;        /* Context for active pre-update callback */
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
 #ifndef SQLITE_OMIT_WAL
   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
   void *pWalArg;
@@ -9541,45 +13932,41 @@ struct sqlite3 {
   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
   void *pCollNeededArg;
   sqlite3_value *pErr;          /* Most recent error message */
-  char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
-  char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
   union {
     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
     double notUsed1;            /* Spacer */
   } u1;
   Lookaside lookaside;          /* Lookaside malloc configuration */
 #ifndef SQLITE_OMIT_AUTHORIZATION
-  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
-                                /* Access authorization function */
+  sqlite3_xauth xAuth;          /* Access authorization function */
   void *pAuthArg;               /* 1st argument to the access auth function */
 #endif
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   int (*xProgress)(void *);     /* The progress callback */
   void *pProgressArg;           /* Argument to the progress callback */
-  int nProgressOps;             /* Number of opcodes for progress callback */
+  unsigned nProgressOps;        /* Number of opcodes for progress callback */
 #endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
+  int nVTrans;                  /* Allocated size of aVTrans */
   Hash aModule;                 /* populated by sqlite3_create_module() */
   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
   VTable **aVTrans;             /* Virtual tables with open transactions */
-  int nVTrans;                  /* Allocated size of aVTrans */
   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
 #endif
-  FuncDefHash aFunc;            /* Hash table of connection functions */
+  Hash aFunc;                   /* Hash table of connection functions */
   Hash aCollSeq;                /* All collating sequences */
   BusyHandler busyHandler;      /* Busy callback */
-  int busyTimeout;              /* Busy handler timeout, in msec */
   Db aDbStatic[2];              /* Static space for the 2 default backends */
   Savepoint *pSavepoint;        /* List of active savepoints */
+  int busyTimeout;              /* Busy handler timeout, in msec */
   int nSavepoint;               /* Number of non-transaction savepoints */
   int nStatement;               /* Number of nested statement-transactions  */
-  u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
+  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
-
 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
-  /* The following variables are all protected by the STATIC_MASTER 
-  ** mutex, not by sqlite3.mutex. They are used by code in notify.c. 
+  /* The following variables are all protected by the STATIC_MASTER
+  ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
   **
   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
   ** unlock so that it can proceed.
@@ -9594,59 +13981,97 @@ struct sqlite3 {
   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
 #endif
+#ifdef SQLITE_USER_AUTHENTICATION
+  sqlite3_userauth auth;        /* User authentication information */
+#endif
 };
 
 /*
 ** A macro to discover the encoding of a database.
 */
-#define ENC(db) ((db)->aDb[0].pSchema->enc)
+#define SCHEMA_ENC(db) ((db)->aDb[0].pSchema->enc)
+#define ENC(db)        ((db)->enc)
 
 /*
 ** Possible values for the sqlite3.flags.
-*/
-#define SQLITE_VdbeTrace      0x00000100  /* True to trace VDBE execution */
-#define SQLITE_InternChanges  0x00000200  /* Uncommitted Hash table changes */
-#define SQLITE_FullColNames   0x00000400  /* Show full column names on SELECT */
-#define SQLITE_ShortColNames  0x00000800  /* Show short columns names */
-#define SQLITE_CountRows      0x00001000  /* Count rows changed by INSERT, */
+**
+** Value constraints (enforced via assert()):
+**      SQLITE_FullFSync     == PAGER_FULLFSYNC
+**      SQLITE_CkptFullFSync == PAGER_CKPT_FULLFSYNC
+**      SQLITE_CacheSpill    == PAGER_CACHE_SPILL
+*/
+#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
+#define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
+#define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
+#define SQLITE_FullFSync      0x00000008  /* Use full fsync on the backend */
+#define SQLITE_CkptFullFSync  0x00000010  /* Use full fsync for checkpoint */
+#define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */
+#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
+#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                           /*   DELETE, or UPDATE and return */
                                           /*   the count using a callback. */
-#define SQLITE_NullCallback   0x00002000  /* Invoke the callback once if the */
+#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                           /*   result set is empty */
-#define SQLITE_SqlTrace       0x00004000  /* Debug print SQL as it executes */
-#define SQLITE_VdbeListing    0x00008000  /* Debug listings of VDBE programs */
-#define SQLITE_WriteSchema    0x00010000  /* OK to update SQLITE_MASTER */
-#define SQLITE_NoReadlock     0x00020000  /* Readlocks are omitted when 
-                                          ** accessing read-only databases */
-#define SQLITE_IgnoreChecks   0x00040000  /* Do not enforce check constraints */
-#define SQLITE_ReadUncommitted 0x0080000  /* For shared-cache mode */
-#define SQLITE_LegacyFileFmt  0x00100000  /* Create new databases in format 1 */
-#define SQLITE_FullFSync      0x00200000  /* Use full fsync on the backend */
-#define SQLITE_CkptFullFSync  0x00400000  /* Use full fsync for checkpoint */
-#define SQLITE_RecoveryMode   0x00800000  /* Ignore schema errors */
-#define SQLITE_ReverseOrder   0x01000000  /* Reverse unordered SELECTs */
-#define SQLITE_RecTriggers    0x02000000  /* Enable recursive triggers */
-#define SQLITE_ForeignKeys    0x04000000  /* Enforce foreign key constraints  */
-#define SQLITE_AutoIndex      0x08000000  /* Enable automatic indexes */
-#define SQLITE_PreferBuiltin  0x10000000  /* Preference to built-in funcs */
-#define SQLITE_LoadExtension  0x20000000  /* Enable load_extension */
-#define SQLITE_EnableTrigger  0x40000000  /* True to enable triggers */
-
-/*
-** Bits of the sqlite3.flags field that are used by the
-** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface.
-** These must be the low-order bits of the flags field.
-*/
-#define SQLITE_QueryFlattener 0x01        /* Disable query flattening */
-#define SQLITE_ColumnCache    0x02        /* Disable the column cache */
-#define SQLITE_IndexSort      0x04        /* Disable indexes for sorting */
-#define SQLITE_IndexSearch    0x08        /* Disable indexes for searching */
-#define SQLITE_IndexCover     0x10        /* Disable index covering table */
-#define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
-#define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
-#define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
-#define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
-#define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
+#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
+#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
+#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
+#define SQLITE_VdbeAddopTrace 0x00001000  /* Trace sqlite3VdbeAddOp() calls */
+#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
+#define SQLITE_ReadUncommitted 0x0004000  /* For shared-cache mode */
+#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
+#define SQLITE_RecoveryMode   0x00010000  /* Ignore schema errors */
+#define SQLITE_ReverseOrder   0x00020000  /* Reverse unordered SELECTs */
+#define SQLITE_RecTriggers    0x00040000  /* Enable recursive triggers */
+#define SQLITE_ForeignKeys    0x00080000  /* Enforce foreign key constraints  */
+#define SQLITE_AutoIndex      0x00100000  /* Enable automatic indexes */
+#define SQLITE_PreferBuiltin  0x00200000  /* Preference to built-in funcs */
+#define SQLITE_LoadExtension  0x00400000  /* Enable load_extension */
+#define SQLITE_LoadExtFunc    0x00800000  /* Enable load_extension() SQL func */
+#define SQLITE_EnableTrigger  0x01000000  /* True to enable triggers */
+#define SQLITE_DeferFKs       0x02000000  /* Defer all FK constraints */
+#define SQLITE_QueryOnly      0x04000000  /* Disable database changes */
+#define SQLITE_VdbeEQP        0x08000000  /* Debug EXPLAIN QUERY PLAN */
+#define SQLITE_Vacuum         0x10000000  /* Currently in a VACUUM */
+#define SQLITE_CellSizeCk     0x20000000  /* Check btree cell sizes on load */
+#define SQLITE_Fts3Tokenizer  0x40000000  /* Enable fts3_tokenizer(2) */
+
+
+/*
+** Bits of the sqlite3.dbOptFlags field that are used by the
+** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
+** selectively disable various optimizations.
+*/
+#define SQLITE_QueryFlattener 0x0001   /* Query flattening */
+#define SQLITE_ColumnCache    0x0002   /* Column cache */
+#define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */
+#define SQLITE_FactorOutConst 0x0008   /* Constant factoring */
+/*                not used    0x0010   // Was: SQLITE_IdxRealAsInt */
+#define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
+#define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
+#define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
+#define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
+#define SQLITE_Transitive     0x0200   /* Transitive constraints */
+#define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
+#define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
+#define SQLITE_CursorHints    0x2000   /* Add OP_CursorHint opcodes */
+#define SQLITE_AllOpts        0xffff   /* All optimizations */
+
+/*
+** Macros for testing whether or not optimizations are enabled or disabled.
+*/
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
+#define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)
+#else
+#define OptimizationDisabled(db, mask)  0
+#define OptimizationEnabled(db, mask)   1
+#endif
+
+/*
+** Return true if it OK to factor constant expressions into the initialization
+** code. The argument is a Parse object for the code generator.
+*/
+#define ConstFactorOk(P) ((P)->okConstFactor)
 
 /*
 ** Possible values for the sqlite.magic field.
@@ -9658,32 +14083,37 @@ struct sqlite3 {
 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
+#define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */
 
 /*
 ** Each SQL function is defined by an instance of the following
-** structure.  A pointer to this structure is stored in the sqlite.aFunc
-** hash table.  When multiple functions have the same name, the hash table
-** points to a linked list of these structures.
+** structure.  For global built-in functions (ex: substr(), max(), count())
+** a pointer to this structure is held in the sqlite3BuiltinFunctions object.
+** For per-connection application-defined functions, a pointer to this
+** structure is held in the db->aHash hash table.
+**
+** The u.pHash field is used by the global built-ins.  The u.pDestructor
+** field is used by per-connection app-def functions.
 */
 struct FuncDef {
-  i16 nArg;            /* Number of arguments.  -1 means unlimited */
-  u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
-  u8 flags;            /* Some combination of SQLITE_FUNC_* */
+  i8 nArg;             /* Number of arguments.  -1 means unlimited */
+  u16 funcFlags;       /* Some combination of SQLITE_FUNC_* */
   void *pUserData;     /* User data parameter */
   FuncDef *pNext;      /* Next function with same name */
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
-  void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
-  void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
-  char *zName;         /* SQL name of the function. */
-  FuncDef *pHash;      /* Next with a different name but the same hash */
-  FuncDestructor *pDestructor;   /* Reference counted destructor function */
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**); /* func or agg-step */
+  void (*xFinalize)(sqlite3_context*);                  /* Agg finalizer */
+  const char *zName;   /* SQL name of the function. */
+  union {
+    FuncDef *pHash;      /* Next with a different name but the same hash */
+    FuncDestructor *pDestructor;   /* Reference counted destructor function */
+  } u;
 };
 
 /*
 ** This structure encapsulates a user-function destructor callback (as
 ** configured using create_function_v2()) and a reference counter. When
 ** create_function_v2() is called to create a function with a destructor,
-** a single object of this type is allocated. FuncDestructor.nRef is set to 
+** a single object of this type is allocated. FuncDestructor.nRef is set to
 ** the number of FuncDef objects created (either 1 or 3, depending on whether
 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
 ** member of each of the new FuncDef objects is set to point to the allocated
@@ -9700,27 +14130,53 @@ struct FuncDestructor {
 };
 
 /*
-** Possible values for FuncDef.flags
-*/
-#define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
-#define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
-#define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
-#define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
-#define SQLITE_FUNC_PRIVATE  0x10 /* Allowed for internal use only */
-#define SQLITE_FUNC_COUNT    0x20 /* Built-in count(*) aggregate */
-#define SQLITE_FUNC_COALESCE 0x40 /* Built-in coalesce() or ifnull() function */
+** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
+** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And
+** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There
+** are assert() statements in the code to verify this.
+**
+** Value constraints (enforced via assert()):
+**     SQLITE_FUNC_MINMAX    ==  NC_MinMaxAgg      == SF_MinMaxAgg
+**     SQLITE_FUNC_LENGTH    ==  OPFLAG_LENGTHARG
+**     SQLITE_FUNC_TYPEOF    ==  OPFLAG_TYPEOFARG
+**     SQLITE_FUNC_CONSTANT  ==  SQLITE_DETERMINISTIC from the API
+**     SQLITE_FUNC_ENCMASK   depends on SQLITE_UTF* macros in the API
+*/
+#define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
+#define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */
+#define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */
+#define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */
+#define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/
+#define SQLITE_FUNC_LENGTH   0x0040 /* Built-in length() function */
+#define SQLITE_FUNC_TYPEOF   0x0080 /* Built-in typeof() function */
+#define SQLITE_FUNC_COUNT    0x0100 /* Built-in count(*) aggregate */
+#define SQLITE_FUNC_COALESCE 0x0200 /* Built-in coalesce() or ifnull() */
+#define SQLITE_FUNC_UNLIKELY 0x0400 /* Built-in unlikely() function */
+#define SQLITE_FUNC_CONSTANT 0x0800 /* Constant inputs give a constant output */
+#define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */
+#define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
+                                    ** single query - might change over time */
 
 /*
 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
 ** used to create the initializers for the FuncDef structures.
 **
 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
-**     Used to create a scalar function definition of a function zName 
+**     Used to create a scalar function definition of a function zName
 **     implemented by C function xFunc that accepts nArg arguments. The
 **     value passed as iArg is cast to a (void*) and made available
-**     as the user-data (sqlite3_user_data()) for the function. If 
+**     as the user-data (sqlite3_user_data()) for the function. If
 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
 **
+**   VFUNCTION(zName, nArg, iArg, bNC, xFunc)
+**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.
+**
+**   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
+**     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
+**     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
+**     and functions like sqlite_version() that can change, but not during
+**     a single query.
+**
 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
 **     Used to create an aggregate function definition implemented by
 **     the C functions xStep and xFinal. The first four parameters
@@ -9728,24 +14184,37 @@ struct FuncDestructor {
 **     FUNCTION().
 **
 **   LIKEFUNC(zName, nArg, pArg, flags)
-**     Used to create a scalar function definition of a function zName 
-**     that accepts nArg arguments and is implemented by a call to C 
+**     Used to create a scalar function definition of a function zName
+**     that accepts nArg arguments and is implemented by a call to C
 **     function likeFunc. Argument pArg is cast to a (void *) and made
 **     available as the function user-data (sqlite3_user_data()). The
 **     FuncDef.flags variable is set to the value passed as the flags
 **     parameter.
 */
 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
-  {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
-   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
+  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+#define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
+  {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+#define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
+  {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
+   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
-  {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
-   pArg, 0, xFunc, 0, 0, #zName, 0, 0}
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
+   pArg, 0, xFunc, 0, #zName, }
 #define LIKEFUNC(zName, nArg, arg, flags) \
-  {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
+  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
+   (void *)arg, 0, likeFunc, 0, #zName, {0} }
 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
-  {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
-   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
+  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
+   SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
+#define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
+  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
+   SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
 
 /*
 ** All current savepoints are stored in a linked list starting at
@@ -9756,6 +14225,7 @@ struct FuncDestructor {
 struct Savepoint {
   char *zName;                        /* Savepoint name (nul-terminated) */
   i64 nDeferredCons;                  /* Number of deferred fk violations */
+  i64 nDeferredImmCons;               /* Number of deferred imm fk. */
   Savepoint *pNext;                   /* Parent savepoint (if any) */
 };
 
@@ -9778,6 +14248,7 @@ struct Module {
   const char *zName;                   /* Name passed to create_module() */
   void *pAux;                          /* pAux passed to create_module() */
   void (*xDestroy)(void *);            /* Module destructor function */
+  Table *pEpoTab;                      /* Eponymous table for this module */
 };
 
 /*
@@ -9785,115 +14256,103 @@ struct Module {
 ** of this structure.
 */
 struct Column {
-  char *zName;     /* Name of this column */
+  char *zName;     /* Name of this column, \000, then the type */
   Expr *pDflt;     /* Default value of this column */
-  char *zDflt;     /* Original text of the default value */
-  char *zType;     /* Data type for this column */
   char *zColl;     /* Collating sequence.  If NULL, use the default */
-  u8 notNull;      /* True if there is a NOT NULL constraint */
-  u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
+  u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */
   char affinity;   /* One of the SQLITE_AFF_... values */
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  u8 isHidden;     /* True if this column is 'hidden' */
-#endif
+  u8 szEst;        /* Estimated size of value in this column. sizeof(INT)==1 */
+  u8 colFlags;     /* Boolean properties.  See COLFLAG_ defines below */
 };
 
+/* Allowed values for Column.colFlags:
+*/
+#define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */
+#define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */
+#define COLFLAG_HASTYPE  0x0004    /* Type name follows column name */
+
 /*
 ** A "Collating Sequence" is defined by an instance of the following
 ** structure. Conceptually, a collating sequence consists of a name and
 ** a comparison routine that defines the order of that sequence.
 **
-** There may two separate implementations of the collation function, one
-** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
-** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
-** native byte order. When a collation sequence is invoked, SQLite selects
-** the version that will require the least expensive encoding
-** translations, if any.
-**
-** The CollSeq.pUser member variable is an extra parameter that passed in
-** as the first argument to the UTF-8 comparison function, xCmp.
-** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
-** xCmp16.
-**
-** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
+** If CollSeq.xCmp is NULL, it means that the
 ** collating sequence is undefined.  Indices built on an undefined
 ** collating sequence may not be read or written.
 */
 struct CollSeq {
   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
   u8 enc;               /* Text encoding handled by xCmp() */
-  u8 type;              /* One of the SQLITE_COLL_... values below */
   void *pUser;          /* First argument to xCmp() */
   int (*xCmp)(void*,int, const void*, int, const void*);
   void (*xDel)(void*);  /* Destructor for pUser */
 };
 
 /*
-** Allowed values of CollSeq.type:
-*/
-#define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
-#define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
-#define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
-#define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
-
-/*
 ** A sort order can be either ASC or DESC.
 */
 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
+#define SQLITE_SO_UNDEFINED -1 /* No sort order specified */
 
 /*
 ** Column affinity types.
 **
 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
-** the speed a little by numbering the values consecutively.  
+** the speed a little by numbering the values consecutively.
 **
-** But rather than start with 0 or 1, we begin with 'a'.  That way,
+** But rather than start with 0 or 1, we begin with 'A'.  That way,
 ** when multiple affinity types are concatenated into a string and
 ** used as the P4 operand, they will be more readable.
 **
 ** Note also that the numeric types are grouped together so that testing
-** for a numeric type is a single comparison.
+** for a numeric type is a single comparison.  And the BLOB type is first.
 */
-#define SQLITE_AFF_TEXT     'a'
-#define SQLITE_AFF_NONE     'b'
-#define SQLITE_AFF_NUMERIC  'c'
-#define SQLITE_AFF_INTEGER  'd'
-#define SQLITE_AFF_REAL     'e'
+#define SQLITE_AFF_BLOB     'A'
+#define SQLITE_AFF_TEXT     'B'
+#define SQLITE_AFF_NUMERIC  'C'
+#define SQLITE_AFF_INTEGER  'D'
+#define SQLITE_AFF_REAL     'E'
 
 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
 
 /*
 ** The SQLITE_AFF_MASK values masks off the significant bits of an
-** affinity value. 
+** affinity value.
 */
-#define SQLITE_AFF_MASK     0x67
+#define SQLITE_AFF_MASK     0x47
 
 /*
 ** Additional bit values that can be ORed with an affinity without
 ** changing the affinity.
+**
+** The SQLITE_NOTNULL flag is a combination of NULLEQ and JUMPIFNULL.
+** It causes an assert() to fire if either operand to a comparison
+** operator is NULL.  It is added to certain comparison operators to
+** prove that the operands are always NOT NULL.
 */
-#define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
-#define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
+#define SQLITE_JUMPIFNULL   0x10  /* jumps if either operand is NULL */
+#define SQLITE_STOREP2      0x20  /* Store result in reg[P2] rather than jump */
 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
+#define SQLITE_NOTNULL      0x90  /* Assert that operands are never NULL */
 
 /*
 ** An object of this type is created for each virtual table present in
-** the database schema. 
+** the database schema.
 **
 ** If the database schema is shared, then there is one instance of this
 ** structure for each database connection (sqlite3*) that uses the shared
 ** schema. This is because each database connection requires its own unique
-** instance of the sqlite3_vtab* handle used to access the virtual table 
-** implementation. sqlite3_vtab* handles can not be shared between 
-** database connections, even when the rest of the in-memory database 
+** instance of the sqlite3_vtab* handle used to access the virtual table
+** implementation. sqlite3_vtab* handles can not be shared between
+** database connections, even when the rest of the in-memory database
 ** schema is shared, as the implementation often stores the database
 ** connection handle passed to it via the xConnect() or xCreate() method
 ** during initialization internally. This database connection handle may
-** then be used by the virtual table implementation to access real tables 
-** within the database. So that they appear as part of the callers 
-** transaction, these accesses need to be made via the same database 
+** then be used by the virtual table implementation to access real tables
+** within the database. So that they appear as part of the callers
+** transaction, these accesses need to be made via the same database
 ** connection as that used to execute SQL operations on the virtual table.
 **
 ** All VTable objects that correspond to a single table in a shared
@@ -9905,19 +14364,19 @@ struct CollSeq {
 ** sqlite3_vtab* handle in the compiled query.
 **
 ** When an in-memory Table object is deleted (for example when the
-** schema is being reloaded for some reason), the VTable objects are not 
-** deleted and the sqlite3_vtab* handles are not xDisconnect()ed 
+** schema is being reloaded for some reason), the VTable objects are not
+** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
 ** immediately. Instead, they are moved from the Table.pVTable list to
 ** another linked list headed by the sqlite3.pDisconnect member of the
-** corresponding sqlite3 structure. They are then deleted/xDisconnected 
+** corresponding sqlite3 structure. They are then deleted/xDisconnected
 ** next time a statement is prepared using said sqlite3*. This is done
 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
 ** Refer to comments above function sqlite3VtabUnlockList() for an
 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
 ** list without holding the corresponding sqlite3.mutex mutex.
 **
-** The memory for objects of this type is always allocated by 
-** sqlite3DbMalloc(), using the connection handle stored in VTable.db as 
+** The memory for objects of this type is always allocated by
+** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
 ** the first argument.
 */
 struct VTable {
@@ -9931,59 +14390,36 @@ struct VTable {
 };
 
 /*
-** Each SQL table is represented in memory by an instance of the
-** following structure.
-**
-** Table.zName is the name of the table.  The case of the original
-** CREATE TABLE statement is stored, but case is not significant for
-** comparisons.
-**
-** Table.nCol is the number of columns in this table.  Table.aCol is a
-** pointer to an array of Column structures, one for each column.
-**
-** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
-** the column that is that key.   Otherwise Table.iPKey is negative.  Note
-** that the datatype of the PRIMARY KEY must be INTEGER for this field to
-** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
-** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
-** is generated for each row of the table.  TF_HasPrimaryKey is set if
-** the table has any PRIMARY KEY, INTEGER or otherwise.
-**
-** Table.tnum is the page number for the root BTree page of the table in the
-** database file.  If Table.iDb is the index of the database table backend
-** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
-** holds temporary tables and indices.  If TF_Ephemeral is set
-** then the table is stored in a file that is automatically deleted
-** when the VDBE cursor to the table is closed.  In this case Table.tnum 
-** refers VDBE cursor number that holds the table open, not to the root
-** page number.  Transient tables are used to hold the results of a
-** sub-query that appears instead of a real table name in the FROM clause 
-** of a SELECT statement.
+** The schema for each SQL table and view is represented in memory
+** by an instance of the following structure.
 */
 struct Table {
   char *zName;         /* Name of the table or view */
-  int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
-  int nCol;            /* Number of columns in this table */
   Column *aCol;        /* Information about each column */
   Index *pIndex;       /* List of SQL indexes on this table. */
-  int tnum;            /* Root BTree node for this table (see note above) */
-  tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
-  u16 nRef;            /* Number of pointers to this Table */
-  u8 tabFlags;         /* Mask of TF_* values */
-  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
   FKey *pFKey;         /* Linked list of all foreign keys in this table */
   char *zColAff;       /* String defining the affinity of each column */
-#ifndef SQLITE_OMIT_CHECK
-  Expr *pCheck;        /* The AND of all CHECK constraints */
+  ExprList *pCheck;    /* All CHECK constraints */
+                       /*   ... also used as column name list in a VIEW */
+  int tnum;            /* Root BTree page for this table */
+  i16 iPKey;           /* If not negative, use aCol[iPKey] as the rowid */
+  i16 nCol;            /* Number of columns in this table */
+  u16 nRef;            /* Number of pointers to this Table */
+  LogEst nRowLogEst;   /* Estimated rows in table - from sqlite_stat1 table */
+  LogEst szTabRow;     /* Estimated size of each table row in bytes */
+#ifdef SQLITE_ENABLE_COSTMULT
+  LogEst costMult;     /* Cost multiplier for using this table */
 #endif
+  u8 tabFlags;         /* Mask of TF_* values */
+  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
 #ifndef SQLITE_OMIT_ALTERTABLE
   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
 #endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  VTable *pVTable;     /* List of VTable objects. */
   int nModuleArg;      /* Number of arguments to the module */
-  char **azModuleArg;  /* Text of all module args. [0] is module name */
+  char **azModuleArg;  /* 0: module 1: schema 2: vtab name 3...: args */
+  VTable *pVTable;     /* List of VTable objects. */
 #endif
   Trigger *pTrigger;   /* List of triggers stored in pSchema */
   Schema *pSchema;     /* Schema that contains this table */
@@ -9991,15 +14427,22 @@ struct Table {
 };
 
 /*
-** Allowed values for Tabe.tabFlags.
+** Allowed values for Table.tabFlags.
+**
+** TF_OOOHidden applies to tables or view that have hidden columns that are
+** followed by non-hidden columns.  Example:  "CREATE VIRTUAL TABLE x USING
+** vtab1(a HIDDEN, b);".  Since "b" is a non-hidden column but "a" is hidden,
+** the TF_OOOHidden attribute would apply in this case.  Such tables require
+** special handling during INSERT processing.
 */
 #define TF_Readonly        0x01    /* Read-only system table */
 #define TF_Ephemeral       0x02    /* An ephemeral table */
 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
 #define TF_Virtual         0x10    /* Is a virtual table */
-#define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
-
+#define TF_WithoutRowid    0x20    /* No rowid.  PRIMARY KEY is the key */
+#define TF_NoVisibleRowid  0x40    /* No user-visible "rowid" column */
+#define TF_OOOHidden       0x80    /* Out-of-Order hidden columns */
 
 
 /*
@@ -10009,13 +14452,33 @@ struct Table {
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
-#  define IsHiddenColumn(X) ((X)->isHidden)
 #else
 #  define IsVirtual(X)      0
-#  define IsHiddenColumn(X) 0
 #endif
 
 /*
+** Macros to determine if a column is hidden.  IsOrdinaryHiddenColumn()
+** only works for non-virtual tables (ordinary tables and views) and is
+** always false unless SQLITE_ENABLE_HIDDEN_COLUMNS is defined.  The
+** IsHiddenColumn() macro is general purpose.
+*/
+#if defined(SQLITE_ENABLE_HIDDEN_COLUMNS)
+#  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#  define IsOrdinaryHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#elif !defined(SQLITE_OMIT_VIRTUALTABLE)
+#  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
+#  define IsOrdinaryHiddenColumn(X) 0
+#else
+#  define IsHiddenColumn(X)         0
+#  define IsOrdinaryHiddenColumn(X) 0
+#endif
+
+
+/* Does the table have a rowid */
+#define HasRowid(X)     (((X)->tabFlags & TF_WithoutRowid)==0)
+#define VisibleRowid(X) (((X)->tabFlags & TF_NoVisibleRowid)==0)
+
+/*
 ** Each foreign key constraint is an instance of the following structure.
 **
 ** A foreign key is associated with two tables.  The "from" table is
@@ -10029,26 +14492,35 @@ struct Table {
 **     );
 **
 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
+** Equivalent names:
+**
+**     from-table == child-table
+**       to-table == parent-table
 **
 ** Each REFERENCES clause generates an instance of the following structure
 ** which is attached to the from-table.  The to-table need not exist when
 ** the from-table is created.  The existence of the to-table is not checked.
+**
+** The list of all parents for child Table X is held at X.pFKey.
+**
+** A list of all children for a table named Z (which might not even exist)
+** is held in Schema.fkeyHash with a hash key of Z.
 */
 struct FKey {
   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
-  FKey *pNextFrom;  /* Next foreign key in pFrom */
+  FKey *pNextFrom;  /* Next FKey with the same in pFrom. Next parent of pFrom */
   char *zTo;        /* Name of table that the key points to (aka: Parent) */
-  FKey *pNextTo;    /* Next foreign key on table named zTo */
-  FKey *pPrevTo;    /* Previous foreign key on table named zTo */
+  FKey *pNextTo;    /* Next with the same zTo. Next child of zTo. */
+  FKey *pPrevTo;    /* Previous with the same zTo */
   int nCol;         /* Number of columns in this key */
   /* EV: R-30323-21917 */
-  u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
-  u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
-  Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
-  struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
-    int iFrom;         /* Index of column in pFrom */
-    char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
-  } aCol[1];        /* One entry for each of nCol column s */
+  u8 isDeferred;       /* True if constraint checking is deferred till COMMIT */
+  u8 aAction[2];        /* ON DELETE and ON UPDATE actions, respectively */
+  Trigger *apTrigger[2];/* Triggers for aAction[] actions */
+  struct sColMap {      /* Mapping of columns in pFrom to columns in zTo */
+    int iFrom;            /* Index of column in pFrom */
+    char *zCol;           /* Name of column in zTo.  If NULL use PRIMARY KEY */
+  } aCol[1];            /* One entry for each of nCol columns */
 };
 
 /*
@@ -10072,7 +14544,7 @@ struct FKey {
 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
 ** referenced table row is propagated into the row that holds the
 ** foreign key.
-** 
+**
 ** The following symbolic values are used to record which type
 ** of action to take.
 */
@@ -10088,26 +14560,31 @@ struct FKey {
 #define OE_SetDflt  8   /* Set the foreign key value to its default */
 #define OE_Cascade  9   /* Cascade the changes */
 
-#define OE_Default  99  /* Do whatever the default action is */
+#define OE_Default  10  /* Do whatever the default action is */
 
 
 /*
 ** An instance of the following structure is passed as the first
-** argument to sqlite3VdbeKeyCompare and is used to control the 
+** argument to sqlite3VdbeKeyCompare and is used to control the
 ** comparison of the two index keys.
+**
+** Note that aSortOrder[] and aColl[] have nField+1 slots.  There
+** are nField slots for the columns of an index then one extra slot
+** for the rowid at the end.
 */
 struct KeyInfo {
-  sqlite3 *db;        /* The database connection */
+  u32 nRef;           /* Number of references to this KeyInfo object */
   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
-  u16 nField;         /* Number of entries in aColl[] */
-  u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
+  u16 nField;         /* Number of key columns in the index */
+  u16 nXField;        /* Number of columns beyond the key columns */
+  sqlite3 *db;        /* The database connection */
+  u8 *aSortOrder;     /* Sort order for each column. */
   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
 };
 
 /*
-** An instance of the following structure holds information about a
-** single index record that has already been parsed out into individual
-** values.
+** This object holds a record which has been parsed out into individual
+** fields, for the purposes of doing a comparison.
 **
 ** A record is an object that contains one or more fields of data.
 ** Records are used to store the content of a table row and to store
@@ -10115,26 +14592,42 @@ struct KeyInfo {
 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
 ** OP_Column opcode.
 **
-** This structure holds a record that has already been disassembled
-** into its constituent fields.
+** An instance of this object serves as a "key" for doing a search on
+** an index b+tree. The goal of the search is to find the entry that
+** is closed to the key described by this object.  This object might hold
+** just a prefix of the key.  The number of fields is given by
+** pKeyInfo->nField.
+**
+** The r1 and r2 fields are the values to return if this key is less than
+** or greater than a key in the btree, respectively.  These are normally
+** -1 and +1 respectively, but might be inverted to +1 and -1 if the b-tree
+** is in DESC order.
+**
+** The key comparison functions actually return default_rc when they find
+** an equals comparison.  default_rc can be -1, 0, or +1.  If there are
+** multiple entries in the b-tree with the same key (when only looking
+** at the first pKeyInfo->nFields,) then default_rc can be set to -1 to
+** cause the search to find the last match, or +1 to cause the search to
+** find the first match.
+**
+** The key comparison functions will set eqSeen to true if they ever
+** get and equal results when comparing this structure to a b-tree record.
+** When default_rc!=0, the search might end up on the record immediately
+** before the first match or immediately after the last match.  The
+** eqSeen field will indicate whether or not an exact match exists in the
+** b-tree.
 */
 struct UnpackedRecord {
   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
-  u16 nField;         /* Number of entries in apMem[] */
-  u16 flags;          /* Boolean settings.  UNPACKED_... below */
-  i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
   Mem *aMem;          /* Values */
+  u16 nField;         /* Number of entries in apMem[] */
+  i8 default_rc;      /* Comparison result if keys are equal */
+  u8 errCode;         /* Error detected by xRecordCompare (CORRUPT or NOMEM) */
+  i8 r1;              /* Value to return if (lhs > rhs) */
+  i8 r2;              /* Value to return if (rhs < lhs) */
+  u8 eqSeen;          /* True if an equality comparison has been seen */
 };
 
-/*
-** Allowed values of UnpackedRecord.flags
-*/
-#define UNPACKED_NEED_FREE     0x0001  /* Memory is from sqlite3Malloc() */
-#define UNPACKED_NEED_DESTROY  0x0002  /* apMem[]s should all be destroyed */
-#define UNPACKED_IGNORE_ROWID  0x0004  /* Ignore trailing rowid on key1 */
-#define UNPACKED_INCRKEY       0x0008  /* Make this key an epsilon larger */
-#define UNPACKED_PREFIX_MATCH  0x0010  /* A prefix match is considered OK */
-#define UNPACKED_PREFIX_SEARCH 0x0020  /* A prefix match is considered OK */
 
 /*
 ** Each SQL index is represented in memory by an
@@ -10150,7 +14643,7 @@ struct UnpackedRecord {
 ** In the Table structure describing Ex1, nCol==3 because there are
 ** three columns in the table.  In the Index structure describing
 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
-** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the 
+** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
 ** The second column to be indexed (c1) has an index of 0 in
 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
@@ -10158,48 +14651,81 @@ struct UnpackedRecord {
 ** The Index.onError field determines whether or not the indexed columns
 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
 ** it means this is not a unique index.  Otherwise it is a unique index
-** and the value of Index.onError indicate the which conflict resolution 
+** and the value of Index.onError indicate the which conflict resolution
 ** algorithm to employ whenever an attempt is made to insert a non-unique
 ** element.
+**
+** While parsing a CREATE TABLE or CREATE INDEX statement in order to
+** generate VDBE code (as opposed to parsing one read from an sqlite_master
+** table as part of parsing an existing database schema), transient instances
+** of this structure may be created. In this case the Index.tnum variable is
+** used to store the address of a VDBE instruction, not a database page
+** number (it cannot - the database page is not allocated until the VDBE
+** program is executed). See convertToWithoutRowidTable() for details.
 */
 struct Index {
-  char *zName;     /* Name of this index */
-  int nColumn;     /* Number of columns in the table used by this index */
-  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
-  tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
-  Table *pTable;   /* The SQL table being indexed */
-  int tnum;        /* Page containing root of this index in database file */
-  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
-  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
-  u8 bUnordered;   /* Use this index for == or IN queries only */
-  char *zColAff;   /* String defining the affinity of each column */
-  Index *pNext;    /* The next index associated with the same table */
-  Schema *pSchema; /* Schema containing this index */
-  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
-  char **azColl;   /* Array of collation sequence names for index */
-#ifdef SQLITE_ENABLE_STAT3
+  char *zName;             /* Name of this index */
+  i16 *aiColumn;           /* Which columns are used by this index.  1st is 0 */
+  LogEst *aiRowLogEst;     /* From ANALYZE: Est. rows selected by each column */
+  Table *pTable;           /* The SQL table being indexed */
+  char *zColAff;           /* String defining the affinity of each column */
+  Index *pNext;            /* The next index associated with the same table */
+  Schema *pSchema;         /* Schema containing this index */
+  u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
+  const char **azColl;     /* Array of collation sequence names for index */
+  Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
+  ExprList *aColExpr;      /* Column expressions */
+  int tnum;                /* DB Page containing root of this index */
+  LogEst szIdxRow;         /* Estimated average row size in bytes */
+  u16 nKeyCol;             /* Number of columns forming the key */
+  u16 nColumn;             /* Number of columns stored in the index */
+  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
+  unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
+  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
+  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
+  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
+  unsigned isCovering:1;   /* True if this is a covering index */
+  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   int nSample;             /* Number of elements in aSample[] */
-  tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
+  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
+  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
   IndexSample *aSample;    /* Samples of the left-most key */
+  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
+  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
 #endif
 };
 
 /*
-** Each sample stored in the sqlite_stat3 table is represented in memory 
+** Allowed values for Index.idxType
+*/
+#define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */
+#define SQLITE_IDXTYPE_UNIQUE      1   /* Implements a UNIQUE constraint */
+#define SQLITE_IDXTYPE_PRIMARYKEY  2   /* Is the PRIMARY KEY for the table */
+
+/* Return true if index X is a PRIMARY KEY index */
+#define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)
+
+/* Return true if index X is a UNIQUE index */
+#define IsUniqueIndex(X)      ((X)->onError!=OE_None)
+
+/* The Index.aiColumn[] values are normally positive integer.  But
+** there are some negative values that have special meaning:
+*/
+#define XN_ROWID     (-1)     /* Indexed column is the rowid */
+#define XN_EXPR      (-2)     /* Indexed column is an expression */
+
+/*
+** Each sample stored in the sqlite_stat3 table is represented in memory
 ** using a structure of this type.  See documentation at the top of the
 ** analyze.c source file for additional information.
 */
 struct IndexSample {
-  union {
-    char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
-    double r;       /* Value if eType is SQLITE_FLOAT */
-    i64 i;          /* Value if eType is SQLITE_INTEGER */
-  } u;
-  u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
-  int nByte;        /* Size in byte of text or blob. */
-  tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
-  tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
-  tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
+  void *p;          /* Pointer to sampled record */
+  int n;            /* Size of record in bytes */
+  tRowcnt *anEq;    /* Est. number of rows where the key equals this sample */
+  tRowcnt *anLt;    /* Est. number of rows where key is less than this sample */
+  tRowcnt *anDLt;   /* Est. number of distinct keys less than this sample */
 };
 
 /*
@@ -10235,8 +14761,9 @@ struct AggInfo {
                           ** than the source table */
   int sortingIdx;         /* Cursor number of the sorting index */
   int sortingIdxPTab;     /* Cursor number of pseudo-table */
-  ExprList *pGroupBy;     /* The group by clause */
   int nSortingColumn;     /* Number of columns in the sorting index */
+  int mnReg, mxReg;       /* Range of registers allocated for aCol and aFunc */
+  ExprList *pGroupBy;     /* The group by clause */
   struct AggInfo_col {    /* For each column used in source tables */
     Table *pTab;             /* Source table */
     int iTable;              /* Cursor number of the source table */
@@ -10246,7 +14773,6 @@ struct AggInfo {
     Expr *pExpr;             /* The original expression */
   } *aCol;
   int nColumn;            /* Number of used entries in aCol[] */
-  int nColumnAlloc;       /* Number of slots allocated for aCol[] */
   int nAccumulator;       /* Number of columns that show through to the output.
                           ** Additional columns are used only as parameters to
                           ** aggregate functions */
@@ -10257,7 +14783,6 @@ struct AggInfo {
     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
   } *aFunc;
   int nFunc;              /* Number of entries in aFunc[] */
-  int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
 };
 
 /*
@@ -10286,9 +14811,9 @@ typedef int ynVar;
 ** to represent the greater-than-or-equal-to operator in the expression
 ** tree.
 **
-** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB, 
+** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
-** the expression is a variable (TK_VARIABLE), then Expr.token contains the 
+** the expression is a variable (TK_VARIABLE), then Expr.token contains the
 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
 ** then Expr.token contains the name of the function.
 **
@@ -10299,7 +14824,7 @@ typedef int ynVar;
 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
-** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is 
+** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
 ** valid.
 **
 ** An expression of the form ID or ID.ID refers to a column in a table.
@@ -10310,8 +14835,8 @@ typedef int ynVar;
 ** value is also stored in the Expr.iAgg column in the aggregate so that
 ** it can be accessed after all aggregates are computed.
 **
-** If the expression is an unbound variable marker (a question mark 
-** character '?' in the original SQL) then the Expr.iTable holds the index 
+** If the expression is an unbound variable marker (a question mark
+** character '?' in the original SQL) then the Expr.iTable holds the index
 ** number for that variable.
 **
 ** If the expression is a subquery then Expr.iColumn holds an integer
@@ -10342,7 +14867,7 @@ typedef int ynVar;
 struct Expr {
   u8 op;                 /* Operation performed by this node */
   char affinity;         /* The affinity of the column or 0 if not a column */
-  u16 flags;             /* Various flags.  EP_* See below */
+  u32 flags;             /* Various flags.  EP_* See below */
   union {
     char *zToken;          /* Token value. Zero terminated and dequoted */
     int iValue;            /* Non-negative integer value if EP_IntValue */
@@ -10350,88 +14875,93 @@ struct Expr {
 
   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
   ** space is allocated for the fields below this point. An attempt to
-  ** access them will result in a segfault or malfunction. 
+  ** access them will result in a segfault or malfunction.
   *********************************************************************/
 
   Expr *pLeft;           /* Left subnode */
   Expr *pRight;          /* Right subnode */
   union {
-    ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
-    Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
+    ExprList *pList;     /* op = IN, EXISTS, SELECT, CASE, FUNCTION, BETWEEN */
+    Select *pSelect;     /* EP_xIsSelect and op = IN, EXISTS, SELECT */
   } x;
-  CollSeq *pColl;        /* The collation type of the column or 0 */
 
   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
   ** space is allocated for the fields below this point. An attempt to
   ** access them will result in a segfault or malfunction.
   *********************************************************************/
 
+#if SQLITE_MAX_EXPR_DEPTH>0
+  int nHeight;           /* Height of the tree headed by this node */
+#endif
   int iTable;            /* TK_COLUMN: cursor number of table holding column
                          ** TK_REGISTER: register number
-                         ** TK_TRIGGER: 1 -> new, 0 -> old */
+                         ** TK_TRIGGER: 1 -> new, 0 -> old
+                         ** EP_Unlikely:  134217728 times likelihood */
   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                          ** TK_VARIABLE: variable number (always >= 1). */
   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
-  u8 flags2;             /* Second set of flags.  EP2_... */
-  u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
+  u8 op2;                /* TK_REGISTER: original value of Expr.op
+                         ** TK_COLUMN: the value of p5 for OP_Column
+                         ** TK_AGG_FUNCTION: nesting depth */
   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
   Table *pTab;           /* Table for TK_COLUMN expressions. */
-#if SQLITE_MAX_EXPR_DEPTH>0
-  int nHeight;           /* Height of the tree headed by this node */
-#endif
 };
 
 /*
 ** The following are the meanings of bits in the Expr.flags field.
 */
-#define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
-#define EP_Agg        0x0002  /* Contains one or more aggregate functions */
-#define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
-#define EP_Error      0x0008  /* Expression contains one or more errors */
-#define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
-#define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
-#define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
-#define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
-#define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
-#define EP_FixedDest  0x0200  /* Result needed in a specific register */
-#define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
-#define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
-
-#define EP_Reduced    0x1000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
-#define EP_TokenOnly  0x2000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
-#define EP_Static     0x4000  /* Held in memory not obtained from malloc() */
-
-/*
-** The following are the meanings of bits in the Expr.flags2 field.
+#define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
+#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
+#define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
+#define EP_Error     0x000008 /* Expression contains one or more errors */
+#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
+#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
+#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
+#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
+#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
+#define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
+#define EP_IntValue  0x000400 /* Integer value contained in u.iValue */
+#define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */
+#define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
+#define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
+#define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
+#define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
+#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
+#define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
+#define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
+#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
+#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
+#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
+#define EP_Alias     0x400000 /* Is an alias for a result set column */
+
+/*
+** Combinations of two or more EP_* flags
+*/
+#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */
+
+/*
+** These macros can be used to test, set, or clear bits in the
+** Expr.flags field.
 */
-#define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
-#define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
+#define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
+#define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))
+#define ExprSetProperty(E,P)     (E)->flags|=(P)
+#define ExprClearProperty(E,P)   (E)->flags&=~(P)
 
-/*
-** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
-** flag on an expression structure.  This flag is used for VV&A only.  The
-** routine is implemented as a macro that only works when in debugging mode,
-** so as not to burden production code.
+/* The ExprSetVVAProperty() macro is used for Verification, Validation,
+** and Accreditation only.  It works like ExprSetProperty() during VVA
+** processes but is a no-op for delivery.
 */
 #ifdef SQLITE_DEBUG
-# define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
+# define ExprSetVVAProperty(E,P)  (E)->flags|=(P)
 #else
-# define ExprSetIrreducible(X)
+# define ExprSetVVAProperty(E,P)
 #endif
 
 /*
-** These macros can be used to test, set, or clear bits in the 
-** Expr.flags field.
-*/
-#define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
-#define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
-#define ExprSetProperty(E,P)     (E)->flags|=(P)
-#define ExprClearProperty(E,P)   (E)->flags&=~(P)
-
-/*
-** Macros to determine the number of bytes required by a normal Expr 
-** struct, an Expr struct with the EP_Reduced flag set in Expr.flags 
+** Macros to determine the number of bytes required by a normal Expr
+** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
 ** and an Expr struct with the EP_TokenOnly flag set.
 */
 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
@@ -10439,7 +14969,7 @@ struct Expr {
 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
 
 /*
-** Flags passed to the sqlite3ExprDup() function. See the header comment 
+** Flags passed to the sqlite3ExprDup() function. See the header comment
 ** above sqlite3ExprDup() for details.
 */
 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
@@ -10451,20 +14981,33 @@ struct Expr {
 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
 ** also be used as the argument to a function, in which case the a.zName
 ** field is not used.
+**
+** By default the Expr.zSpan field holds a human-readable description of
+** the expression that is used in the generation of error messages and
+** column labels.  In this case, Expr.zSpan is typically the text of a
+** column expression as it exists in a SELECT statement.  However, if
+** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
+** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
+** form is used for name resolution with nested FROM clauses.
 */
 struct ExprList {
   int nExpr;             /* Number of expressions on the list */
-  int nAlloc;            /* Number of entries allocated below */
-  int iECursor;          /* VDBE Cursor associated with this ExprList */
-  struct ExprList_item {
-    Expr *pExpr;           /* The list of expressions */
-    char *zName;           /* Token associated with this expression */
-    char *zSpan;           /* Original text of the expression */
-    u8 sortOrder;          /* 1 for DESC or 0 for ASC */
-    u8 done;               /* A flag to indicate when processing is finished */
-    u16 iCol;              /* For ORDER BY, column number in result set */
-    u16 iAlias;            /* Index into Parse.aAlias[] for zName */
-  } *a;                  /* One entry for each expression */
+  struct ExprList_item { /* For each expression in the list */
+    Expr *pExpr;            /* The list of expressions */
+    char *zName;            /* Token associated with this expression */
+    char *zSpan;            /* Original text of the expression */
+    u8 sortOrder;           /* 1 for DESC or 0 for ASC */
+    unsigned done :1;       /* A flag to indicate when processing is finished */
+    unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
+    unsigned reusable :1;   /* Constant expression is reusable */
+    union {
+      struct {
+        u16 iOrderByCol;      /* For ORDER BY, column number in result set */
+        u16 iAlias;           /* Index into Parse.aAlias[] for zName */
+      } x;
+      int iConstExprReg;      /* Register in which Expr value is cached */
+    } u;
+  } *a;                  /* Alloc a power of two greater or equal to nExpr */
 };
 
 /*
@@ -10499,7 +15042,6 @@ struct IdList {
     int idx;          /* Index in some Table.aCol[] of a column named zName */
   } *a;
   int nId;         /* Number of identifiers on the list */
-  int nAlloc;      /* Number of entries allocated for a[] below */
 };
 
 /*
@@ -10509,7 +15051,11 @@ struct IdList {
 ** tables in a join to 32 instead of 64.  But it also reduces the size
 ** of the library by 738 bytes on ix86.
 */
-typedef u64 Bitmask;
+#ifdef SQLITE_BITMASK_TYPE
+  typedef SQLITE_BITMASK_TYPE Bitmask;
+#else
+  typedef u64 Bitmask;
+#endif
 
 /*
 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
@@ -10517,6 +15063,13 @@ typedef u64 Bitmask;
 #define BMS  ((int)(sizeof(Bitmask)*8))
 
 /*
+** A bit in a Bitmask
+*/
+#define MASKBIT(n)   (((Bitmask)1)<<(n))
+#define MASKBIT32(n) (((unsigned int)1)<<(n))
+#define ALLBITS      ((Bitmask)-1)
+
+/*
 ** The following structure describes the FROM clause of a SELECT statement.
 ** Each table or subquery in the FROM clause is a separate element of
 ** the SrcList.a[] array.
@@ -10536,9 +15089,10 @@ typedef u64 Bitmask;
 ** contains more than 63 columns and the 64-th or later column is used.
 */
 struct SrcList {
-  i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
-  i16 nAlloc;      /* Number of entries allocated in a[] below */
+  int nSrc;        /* Number of tables or subqueries in the FROM clause */
+  u32 nAlloc;      /* Number of entries allocated in a[] below */
   struct SrcList_item {
+    Schema *pSchema;  /* Schema to which this item is fixed */
     char *zDatabase;  /* Name of database holding this table */
     char *zName;      /* Name of the table */
     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
@@ -10546,9 +15100,16 @@ struct SrcList {
     Select *pSelect;  /* A SELECT statement used in place of a table name */
     int addrFillSub;  /* Address of subroutine to manifest a subquery */
     int regReturn;    /* Register holding return address of addrFillSub */
-    u8 jointype;      /* Type of join between this able and the previous */
-    u8 notIndexed;    /* True if there is a NOT INDEXED clause */
-    u8 isCorrelated;  /* True if sub-query is correlated */
+    int regResult;    /* Registers holding results of a co-routine */
+    struct {
+      u8 jointype;      /* Type of join between this table and the previous */
+      unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
+      unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
+      unsigned isTabFunc :1;     /* True if table-valued-function syntax */
+      unsigned isCorrelated :1;  /* True if sub-query is correlated */
+      unsigned viaCoroutine :1;  /* Implemented as a co-routine */
+      unsigned isRecursive :1;   /* True for recursive reference in WITH */
+    } fg;
 #ifndef SQLITE_OMIT_EXPLAIN
     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
 #endif
@@ -10556,8 +15117,11 @@ struct SrcList {
     Expr *pOn;        /* The ON clause of a join */
     IdList *pUsing;   /* The USING clause of a join */
     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
-    char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
-    Index *pIndex;    /* Index structure corresponding to zIndex, if any */
+    union {
+      char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
+      ExprList *pFuncArg;  /* Arguments to table-valued-function */
+    } u1;
+    Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
   } a[1];             /* One entry for each identifier on the list */
 };
 
@@ -10574,114 +15138,37 @@ struct SrcList {
 
 
 /*
-** A WherePlan object holds information that describes a lookup
-** strategy.
-**
-** This object is intended to be opaque outside of the where.c module.
-** It is included here only so that that compiler will know how big it
-** is.  None of the fields in this object should be used outside of
-** the where.c module.
-**
-** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
-** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
-** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
-** case that more than one of these conditions is true.
-*/
-struct WherePlan {
-  u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
-  u32 nEq;                       /* Number of == constraints */
-  double nRow;                   /* Estimated number of rows (for EQP) */
-  union {
-    Index *pIdx;                   /* Index when WHERE_INDEXED is true */
-    struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
-    sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
-  } u;
-};
-
-/*
-** For each nested loop in a WHERE clause implementation, the WhereInfo
-** structure contains a single instance of this structure.  This structure
-** is intended to be private the the where.c module and should not be
-** access or modified by other modules.
-**
-** The pIdxInfo field is used to help pick the best index on a
-** virtual table.  The pIdxInfo pointer contains indexing
-** information for the i-th table in the FROM clause before reordering.
-** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
-** All other information in the i-th WhereLevel object for the i-th table
-** after FROM clause ordering.
-*/
-struct WhereLevel {
-  WherePlan plan;       /* query plan for this element of the FROM clause */
-  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
-  int iTabCur;          /* The VDBE cursor used to access the table */
-  int iIdxCur;          /* The VDBE cursor used to access pIdx */
-  int addrBrk;          /* Jump here to break out of the loop */
-  int addrNxt;          /* Jump here to start the next IN combination */
-  int addrCont;         /* Jump here to continue with the next loop cycle */
-  int addrFirst;        /* First instruction of interior of the loop */
-  u8 iFrom;             /* Which entry in the FROM clause */
-  u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
-  int p1, p2;           /* Operands of the opcode used to ends the loop */
-  union {               /* Information that depends on plan.wsFlags */
-    struct {
-      int nIn;              /* Number of entries in aInLoop[] */
-      struct InLoop {
-        int iCur;              /* The VDBE cursor used by this IN operator */
-        int addrInTop;         /* Top of the IN loop */
-      } *aInLoop;           /* Information about each nested IN operator */
-    } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
-  } u;
-
-  /* The following field is really not part of the current level.  But
-  ** we need a place to cache virtual table index information for each
-  ** virtual table in the FROM clause and the WhereLevel structure is
-  ** a convenient place since there is one WhereLevel for each FROM clause
-  ** element.
-  */
-  sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
-};
-
-/*
 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
 ** and the WhereInfo.wctrlFlags member.
+**
+** Value constraints (enforced via assert()):
+**     WHERE_USE_LIMIT  == SF_FixedLimit
 */
 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
-#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
-#define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
-#define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
-#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
-#define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
-
-/*
-** The WHERE clause processing routine has two halves.  The
-** first part does the start of the WHERE loop and the second
-** half does the tail of the WHERE loop.  An instance of
-** this structure is returned by the first half and passed
-** into the second half to give some continuity.
-*/
-struct WhereInfo {
-  Parse *pParse;       /* Parsing and code generating context */
-  u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
-  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
-  u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
-  u8 eDistinct;
-  SrcList *pTabList;             /* List of tables in the join */
-  int iTop;                      /* The very beginning of the WHERE loop */
-  int iContinue;                 /* Jump here to continue with next record */
-  int iBreak;                    /* Jump here to break out of the loop */
-  int nLevel;                    /* Number of nested loop */
-  struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
-  double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
-  double nRowOut;                /* Estimated number of output rows */
-  WhereLevel a[1];               /* Information about each nest loop in WHERE */
-};
-
-#define WHERE_DISTINCT_UNIQUE 1
-#define WHERE_DISTINCT_ORDERED 2
+#define WHERE_ONEPASS_MULTIROW 0x0008 /* ONEPASS is ok with multiple rows */
+#define WHERE_DUPLICATES_OK    0x0010 /* Ok to return a row more than once */
+#define WHERE_OR_SUBCLAUSE     0x0020 /* Processing a sub-WHERE as part of
+                                      ** the OR optimization  */
+#define WHERE_GROUPBY          0x0040 /* pOrderBy is really a GROUP BY */
+#define WHERE_DISTINCTBY       0x0080 /* pOrderby is really a DISTINCT clause */
+#define WHERE_WANT_DISTINCT    0x0100 /* All output needs to be distinct */
+#define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */
+#define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */
+#define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */
+                        /*     0x1000    not currently used */
+                        /*     0x2000    not currently used */
+#define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */
+                        /*     0x8000    not currently used */
+
+/* Allowed return values from sqlite3WhereIsDistinct()
+*/
+#define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
+#define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
+#define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
+#define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
 
 /*
 ** A NameContext defines a context in which to resolve table and column
@@ -10692,12 +15179,12 @@ struct WhereInfo {
 ** pEList corresponds to the result set of a SELECT and is NULL for
 ** other statements.
 **
-** NameContexts can be nested.  When resolving names, the inner-most 
+** NameContexts can be nested.  When resolving names, the inner-most
 ** context is searched first.  If no match is found, the next outer
 ** context is checked.  If there is still no match, the next context
 ** is checked.  This process continues until either a match is found
 ** or all contexts are check.  When a match is found, the nRef member of
-** the context containing the match is incremented. 
+** the context containing the match is incremented.
 **
 ** Each subquery gets a new NameContext.  The pNext field points to the
 ** NameContext in the parent query.  Thus the process of scanning the
@@ -10707,18 +15194,32 @@ struct WhereInfo {
 struct NameContext {
   Parse *pParse;       /* The parser */
   SrcList *pSrcList;   /* One or more tables used to resolve names */
-  ExprList *pEList;    /* Optional list of named expressions */
-  int nRef;            /* Number of names resolved by this context */
-  int nErr;            /* Number of errors encountered while resolving names */
-  u8 allowAgg;         /* Aggregate functions allowed here */
-  u8 hasAgg;           /* True if aggregates are seen */
-  u8 isCheck;          /* True if resolving names in a CHECK constraint */
-  int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
+  ExprList *pEList;    /* Optional list of result-set columns */
   AggInfo *pAggInfo;   /* Information about aggregates at this level */
   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
+  int nRef;            /* Number of names resolved by this context */
+  int nErr;            /* Number of errors encountered while resolving names */
+  u16 ncFlags;         /* Zero or more NC_* flags defined below */
 };
 
 /*
+** Allowed values for the NameContext, ncFlags field.
+**
+** Value constraints (all checked via assert()):
+**    NC_HasAgg    == SF_HasAgg
+**    NC_MinMaxAgg == SF_MinMaxAgg == SQLITE_FUNC_MINMAX
+**
+*/
+#define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
+#define NC_PartIdx   0x0002  /* True if resolving a partial index WHERE */
+#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
+#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
+#define NC_HasAgg    0x0010  /* One or more aggregate functions seen */
+#define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
+#define NC_VarSelect 0x0040  /* A correlated subquery has been seen */
+#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
+
+/*
 ** An instance of the following structure contains all information
 ** needed to generate code for a single SELECT statement.
 **
@@ -10735,14 +15236,19 @@ struct NameContext {
 ** as the OP_OpenEphm instruction is coded because not
 ** enough information about the compound query is known at that point.
 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
-** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
+** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating
 ** sequences for the ORDER BY clause.
 */
 struct Select {
   ExprList *pEList;      /* The fields of the result */
   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
-  char affinity;         /* MakeRecord with this affinity for SRT_Set */
-  u16 selFlags;          /* Various SF_* values */
+  LogEst nSelectRow;     /* Estimated number of result rows */
+  u32 selFlags;          /* Various SF_* values */
+  int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
+#if SELECTTRACE_ENABLED
+  char zSelName[12];     /* Symbolic name of this SELECT use for debugging */
+#endif
+  int addrOpenEphm[2];   /* OP_OpenEphem opcodes related to this select */
   SrcList *pSrc;         /* The FROM clause */
   Expr *pWhere;          /* The WHERE clause */
   ExprList *pGroupBy;    /* The GROUP BY clause */
@@ -10750,65 +15256,142 @@ struct Select {
   ExprList *pOrderBy;    /* The ORDER BY clause */
   Select *pPrior;        /* Prior select in a compound select statement */
   Select *pNext;         /* Next select to the left in a compound */
-  Select *pRightmost;    /* Right-most select in a compound select statement */
   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
-  int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
-  int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
-  double nSelectRow;     /* Estimated number of result rows */
+  With *pWith;           /* WITH clause attached to this select. Or NULL. */
 };
 
 /*
 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
 ** "Select Flag".
-*/
-#define SF_Distinct        0x0001  /* Output should be DISTINCT */
-#define SF_Resolved        0x0002  /* Identifiers have been resolved */
-#define SF_Aggregate       0x0004  /* Contains aggregate functions */
-#define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
-#define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
-#define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
-#define SF_UseSorter       0x0040  /* Sort using a sorter */
-
-
-/*
-** The results of a select can be distributed in several ways.  The
-** "SRT" prefix means "SELECT Result Type".
+**
+** Value constraints (all checked via assert())
+**     SF_HasAgg     == NC_HasAgg
+**     SF_MinMaxAgg  == NC_MinMaxAgg     == SQLITE_FUNC_MINMAX
+**     SF_FixedLimit == WHERE_USE_LIMIT
+*/
+#define SF_Distinct       0x00001  /* Output should be DISTINCT */
+#define SF_All            0x00002  /* Includes the ALL keyword */
+#define SF_Resolved       0x00004  /* Identifiers have been resolved */
+#define SF_Aggregate      0x00008  /* Contains agg functions or a GROUP BY */
+#define SF_HasAgg         0x00010  /* Contains aggregate functions */
+#define SF_UsesEphemeral  0x00020  /* Uses the OpenEphemeral opcode */
+#define SF_Expanded       0x00040  /* sqlite3SelectExpand() called on this */
+#define SF_HasTypeInfo    0x00080  /* FROM subqueries have Table metadata */
+#define SF_Compound       0x00100  /* Part of a compound query */
+#define SF_Values         0x00200  /* Synthesized from VALUES clause */
+#define SF_MultiValue     0x00400  /* Single VALUES term with multiple rows */
+#define SF_NestedFrom     0x00800  /* Part of a parenthesized FROM clause */
+#define SF_MinMaxAgg      0x01000  /* Aggregate containing min() or max() */
+#define SF_Recursive      0x02000  /* The recursive part of a recursive CTE */
+#define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */
+#define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */
+#define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */
+#define SF_IncludeHidden  0x20000  /* Include hidden columns in output */
+
+
+/*
+** The results of a SELECT can be distributed in several ways, as defined
+** by one of the following macros.  The "SRT" prefix means "SELECT Result
+** Type".
+**
+**     SRT_Union       Store results as a key in a temporary index
+**                     identified by pDest->iSDParm.
+**
+**     SRT_Except      Remove results from the temporary index pDest->iSDParm.
+**
+**     SRT_Exists      Store a 1 in memory cell pDest->iSDParm if the result
+**                     set is not empty.
+**
+**     SRT_Discard     Throw the results away.  This is used by SELECT
+**                     statements within triggers whose only purpose is
+**                     the side-effects of functions.
+**
+** All of the above are free to ignore their ORDER BY clause. Those that
+** follow must honor the ORDER BY clause.
+**
+**     SRT_Output      Generate a row of output (using the OP_ResultRow
+**                     opcode) for each row in the result set.
+**
+**     SRT_Mem         Only valid if the result is a single column.
+**                     Store the first column of the first result row
+**                     in register pDest->iSDParm then abandon the rest
+**                     of the query.  This destination implies "LIMIT 1".
+**
+**     SRT_Set         The result must be a single column.  Store each
+**                     row of result as the key in table pDest->iSDParm.
+**                     Apply the affinity pDest->affSdst before storing
+**                     results.  Used to implement "IN (SELECT ...)".
+**
+**     SRT_EphemTab    Create an temporary table pDest->iSDParm and store
+**                     the result there. The cursor is left open after
+**                     returning.  This is like SRT_Table except that
+**                     this destination uses OP_OpenEphemeral to create
+**                     the table first.
+**
+**     SRT_Coroutine   Generate a co-routine that returns a new row of
+**                     results each time it is invoked.  The entry point
+**                     of the co-routine is stored in register pDest->iSDParm
+**                     and the result row is stored in pDest->nDest registers
+**                     starting with pDest->iSdst.
+**
+**     SRT_Table       Store results in temporary table pDest->iSDParm.
+**     SRT_Fifo        This is like SRT_EphemTab except that the table
+**                     is assumed to already be open.  SRT_Fifo has
+**                     the additional property of being able to ignore
+**                     the ORDER BY clause.
+**
+**     SRT_DistFifo    Store results in a temporary table pDest->iSDParm.
+**                     But also use temporary table pDest->iSDParm+1 as
+**                     a record of all prior results and ignore any duplicate
+**                     rows.  Name means:  "Distinct Fifo".
+**
+**     SRT_Queue       Store results in priority queue pDest->iSDParm (really
+**                     an index).  Append a sequence number so that all entries
+**                     are distinct.
+**
+**     SRT_DistQueue   Store results in priority queue pDest->iSDParm only if
+**                     the same record has never been stored before.  The
+**                     index at pDest->iSDParm+1 hold all prior stores.
 */
 #define SRT_Union        1  /* Store result as keys in an index */
 #define SRT_Except       2  /* Remove result from a UNION index */
 #define SRT_Exists       3  /* Store 1 if the result is not empty */
 #define SRT_Discard      4  /* Do not save the results anywhere */
+#define SRT_Fifo         5  /* Store result as data with an automatic rowid */
+#define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */
+#define SRT_Queue        7  /* Store result in an queue */
+#define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */
 
 /* The ORDER BY clause is ignored for all of the above */
-#define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
+#define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)
 
-#define SRT_Output       5  /* Output each row of result */
-#define SRT_Mem          6  /* Store result in a memory cell */
-#define SRT_Set          7  /* Store results as keys in an index */
-#define SRT_Table        8  /* Store result as data with an automatic rowid */
-#define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
-#define SRT_Coroutine   10  /* Generate a single row of result */
+#define SRT_Output       9  /* Output each row of result */
+#define SRT_Mem         10  /* Store result in a memory cell */
+#define SRT_Set         11  /* Store results as keys in an index */
+#define SRT_EphemTab    12  /* Create transient tab and store like SRT_Table */
+#define SRT_Coroutine   13  /* Generate a single row of result */
+#define SRT_Table       14  /* Store result as data with an automatic rowid */
 
 /*
-** A structure used to customize the behavior of sqlite3Select(). See
-** comments above sqlite3Select() for details.
+** An instance of this object describes where to put of the results of
+** a SELECT statement.
 */
-typedef struct SelectDest SelectDest;
 struct SelectDest {
-  u8 eDest;         /* How to dispose of the results */
-  u8 affinity;      /* Affinity used when eDest==SRT_Set */
-  int iParm;        /* A parameter used by the eDest disposal method */
-  int iMem;         /* Base register where results are written */
-  int nMem;         /* Number of registers allocated */
+  u8 eDest;            /* How to dispose of the results.  On of SRT_* above. */
+  char affSdst;        /* Affinity used when eDest==SRT_Set */
+  int iSDParm;         /* A parameter used by the eDest disposal method */
+  int iSdst;           /* Base register where results are written */
+  int nSdst;           /* Number of registers allocated */
+  ExprList *pOrderBy;  /* Key columns for SRT_Queue and SRT_DistQueue */
 };
 
 /*
-** During code generation of statements that do inserts into AUTOINCREMENT 
+** During code generation of statements that do inserts into AUTOINCREMENT
 ** tables, the following information is attached to the Table.u.autoInc.p
 ** pointer of each autoincrement table to record some side information that
 ** the code generator needs.  We have to keep per-table autoincrement
-** information in case inserts are down within triggers.  Triggers do not
+** information in case inserts are done within triggers.  Triggers do not
 ** normally coordinate their activities, but we do need to coordinate the
 ** loading and saving of autoincrement information.
 */
@@ -10827,7 +15410,7 @@ struct AutoincInfo {
 #endif
 
 /*
-** At least one instance of the following structure is created for each 
+** At least one instance of the following structure is created for each
 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
 ** statement. All such objects are stored in the linked list headed at
 ** Parse.pTriggerPrg and deleted once statement compilation has been
@@ -10840,25 +15423,35 @@ struct AutoincInfo {
 ** values for both pTrigger and orconf.
 **
 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
-** accessed (or set to 0 for triggers fired as a result of INSERT 
+** accessed (or set to 0 for triggers fired as a result of INSERT
 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
 ** a mask of new.* columns used by the program.
 */
 struct TriggerPrg {
   Trigger *pTrigger;      /* Trigger this program was coded from */
-  int orconf;             /* Default ON CONFLICT policy */
+  TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
+  int orconf;             /* Default ON CONFLICT policy */
   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
-  TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
 };
 
 /*
 ** The yDbMask datatype for the bitmask of all attached databases.
 */
 #if SQLITE_MAX_ATTACHED>30
-  typedef sqlite3_uint64 yDbMask;
+  typedef unsigned char yDbMask[(SQLITE_MAX_ATTACHED+9)/8];
+# define DbMaskTest(M,I)    (((M)[(I)/8]&(1<<((I)&7)))!=0)
+# define DbMaskZero(M)      memset((M),0,sizeof(M))
+# define DbMaskSet(M,I)     (M)[(I)/8]|=(1<<((I)&7))
+# define DbMaskAllZero(M)   sqlite3DbMaskAllZero(M)
+# define DbMaskNonZero(M)   (sqlite3DbMaskAllZero(M)==0)
 #else
   typedef unsigned int yDbMask;
+# define DbMaskTest(M,I)    (((M)&(((yDbMask)1)<<(I)))!=0)
+# define DbMaskZero(M)      (M)=0
+# define DbMaskSet(M,I)     (M)|=(((yDbMask)1)<<(I))
+# define DbMaskAllZero(M)   (M)==0
+# define DbMaskNonZero(M)   (M)!=0
 #endif
 
 /*
@@ -10871,7 +15464,7 @@ struct TriggerPrg {
 ** is constant but the second part is reset at the beginning and end of
 ** each recursion.
 **
-** The nTableLock and aTableLock variables are only used if the shared-cache 
+** The nTableLock and aTableLock variables are only used if the shared-cache
 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
 ** used to store the set of table-locks required by the statement being
 ** compiled. Function sqlite3TableLock() is used to add entries to the
@@ -10879,16 +15472,19 @@ struct TriggerPrg {
 */
 struct Parse {
   sqlite3 *db;         /* The main database structure */
-  int rc;              /* Return code from execution */
   char *zErrMsg;       /* An error message */
   Vdbe *pVdbe;         /* An engine for executing database bytecode */
+  int rc;              /* Return code from execution */
   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
-  u8 nameClash;        /* A permanent table name clashes with temp table name */
   u8 checkSchema;      /* Causes schema cookie check after an error */
   u8 nested;           /* Number of nested calls to the parser/code generator */
-  u8 parseError;       /* True after a parsing error.  Ticket #1794 */
   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
-  u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
+  u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
+  u8 mayAbort;         /* True if statement may throw an ABORT exception */
+  u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
+  u8 okConstFactor;    /* OK to factor out constants */
+  u8 disableLookaside; /* Number of times lookaside has been disabled */
+  u8 nColCache;        /* Number of entries in aColCache[] */
   int aTempReg[8];     /* Holding area for temporary registers */
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */
@@ -10896,77 +15492,95 @@ struct Parse {
   int nTab;            /* Number of previously allocated VDBE cursors */
   int nMem;            /* Number of memory cells used so far */
   int nSet;            /* Number of sets used so far */
+  int nOnce;           /* Number of OP_Once instructions so far */
+  int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
+  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
+  int iFixedOp;        /* Never back out opcodes iFixedOp-1 or earlier */
   int ckBase;          /* Base register of data during check constraints */
+  int iSelfTab;        /* Table of an index whose exprs are being coded */
   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
-  u8 nColCache;        /* Number of entries in the column cache */
-  u8 iColCache;        /* Next entry of the cache to replace */
+  int nLabel;          /* Number of labels used */
+  int *aLabel;         /* Space to hold the labels */
   struct yColCache {
     int iTable;           /* Table cursor number */
-    int iColumn;          /* Table column number */
+    i16 iColumn;          /* Table column number */
     u8 tempReg;           /* iReg is a temp register that needs to be freed */
     int iLevel;           /* Nesting level */
     int iReg;             /* Reg with value of this column. 0 means none. */
     int lru;              /* Least recently used entry has the smallest value */
   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
+  ExprList *pConstExpr;/* Constant expressions */
+  Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */
-  u8 isMultiWrite;     /* True if statement may affect/insert multiple rows */
-  u8 mayAbort;         /* True if statement may throw an ABORT exception */
-  int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
+  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
+  int regRoot;         /* Register holding root page number for new objects */
+  int nMaxArg;         /* Max args passed to user function by sub-program */
+#if SELECTTRACE_ENABLED
+  int nSelect;         /* Number of SELECT statements seen */
+  int nSelectIndent;   /* How far to indent SELECTTRACE() output */
+#endif
 #ifndef SQLITE_OMIT_SHARED_CACHE
   int nTableLock;        /* Number of locks in aTableLock */
   TableLock *aTableLock; /* Required table locks for shared-cache mode */
 #endif
-  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
-  int regRoot;         /* Register holding root page number for new objects */
   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
-  int nMaxArg;         /* Max args passed to user function by sub-program */
 
   /* Information used while coding trigger programs. */
   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
   Table *pTriggerTab;  /* Table triggers are being coded for */
+  int addrCrTab;       /* Address of OP_CreateTable opcode on CREATE TABLE */
+  u32 nQueryLoop;      /* Est number of iterations of a query (10*log2(N)) */
   u32 oldmask;         /* Mask of old.* columns referenced */
   u32 newmask;         /* Mask of new.* columns referenced */
   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
   u8 disableTriggers;  /* True to disable triggers */
-  double nQueryLoop;   /* Estimated number of iterations of a query */
-
-  /* Above is constant between recursions.  Below is reset before and after
-  ** each recursion */
-
-  int nVar;            /* Number of '?' variables seen in the SQL so far */
-  int nzVar;           /* Number of available slots in azVar[] */
-  char **azVar;        /* Pointers to names of parameters */
-  Vdbe *pReprepare;    /* VM being reprepared (sqlite3Reprepare()) */
-  int nAlias;          /* Number of aliased result set columns */
-  int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
-  int *aAlias;         /* Register used to hold aliased result */
-  u8 explain;          /* True if the EXPLAIN flag is found on the query */
-  Token sNameToken;    /* Token with unqualified schema object name */
-  Token sLastToken;    /* The last token parsed */
-  const char *zTail;   /* All SQL text past the last semicolon parsed */
-  Table *pNewTable;    /* A table being constructed by CREATE TABLE */
-  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
-  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
+
+  /************************************************************************
+  ** Above is constant between recursions.  Below is reset before and after
+  ** each recursion.  The boundary between these two regions is determined
+  ** using offsetof(Parse,nVar) so the nVar field must be the first field
+  ** in the recursive region.
+  ************************************************************************/
+
+  ynVar nVar;               /* Number of '?' variables seen in the SQL so far */
+  int nzVar;                /* Number of available slots in azVar[] */
+  u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
+  u8 explain;               /* True if the EXPLAIN flag is found on the query */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  Token sArg;                /* Complete text of a module argument */
-  u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
-  int nVtabLock;             /* Number of virtual tables to lock */
-  Table **apVtabLock;        /* Pointer to virtual tables needing locking */
+  u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
+  int nVtabLock;            /* Number of virtual tables to lock */
 #endif
-  int nHeight;            /* Expression tree height of current sub-select */
-  Table *pZombieTab;      /* List of Table objects to delete after code gen */
-  TriggerPrg *pTriggerPrg;    /* Linked list of coded triggers */
-
+  int nAlias;               /* Number of aliased result set columns */
+  int nHeight;              /* Expression tree height of current sub-select */
 #ifndef SQLITE_OMIT_EXPLAIN
-  int iSelectId;
-  int iNextSelectId;
+  int iSelectId;            /* ID of current select for EXPLAIN output */
+  int iNextSelectId;        /* Next available select ID for EXPLAIN output */
 #endif
+  char **azVar;             /* Pointers to names of parameters */
+  Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
+  const char *zTail;        /* All SQL text past the last semicolon parsed */
+  Table *pNewTable;         /* A table being constructed by CREATE TABLE */
+  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
+  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
+  Token sNameToken;         /* Token with unqualified schema object name */
+  Token sLastToken;         /* The last token parsed */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  Token sArg;               /* Complete text of a module argument */
+  Table **apVtabLock;       /* Pointer to virtual tables needing locking */
+#endif
+  Table *pZombieTab;        /* List of Table objects to delete after code gen */
+  TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
+  With *pWith;              /* Current WITH clause, or NULL */
+  With *pWithToFree;        /* Free this WITH object at the end of the parse */
 };
 
+/*
+** Return true if currently inside an sqlite3_declare_vtab() call.
+*/
 #ifdef SQLITE_OMIT_VIRTUALTABLE
   #define IN_DECLARE_VTAB 0
 #else
@@ -10983,21 +15597,43 @@ struct AuthContext {
 };
 
 /*
-** Bitfield flags for P5 value in OP_Insert and OP_Delete
+** Bitfield flags for P5 value in various opcodes.
+**
+** Value constraints (enforced via assert()):
+**    OPFLAG_LENGTHARG    == SQLITE_FUNC_LENGTH
+**    OPFLAG_TYPEOFARG    == SQLITE_FUNC_TYPEOF
+**    OPFLAG_BULKCSR      == BTREE_BULKLOAD
+**    OPFLAG_SEEKEQ       == BTREE_SEEK_EQ
+**    OPFLAG_FORDELETE    == BTREE_FORDELETE
+**    OPFLAG_SAVEPOSITION == BTREE_SAVEPOSITION
+**    OPFLAG_AUXDELETE    == BTREE_AUXDELETE
 */
-#define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
+#define OPFLAG_NCHANGE       0x01    /* OP_Insert: Set to update db->nChange */
+                                     /* Also used in P2 (not P5) of OP_Delete */
+#define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
-#define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+#define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */
+#endif
+#define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
+#define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
+#define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
+#define OPFLAG_SEEKEQ        0x02    /* OP_Open** cursor uses EQ seek only */
+#define OPFLAG_FORDELETE     0x08    /* OP_Open should use BTREE_FORDELETE */
+#define OPFLAG_P2ISREG       0x10    /* P2 to OP_Open** is a register number */
+#define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */
+#define OPFLAG_SAVEPOSITION  0x02    /* OP_Delete: keep cursor position */
+#define OPFLAG_AUXDELETE     0x04    /* OP_Delete: index in a DELETE op */
 
 /*
  * Each trigger present in the database schema is stored as an instance of
- * struct Trigger. 
+ * struct Trigger.
  *
  * Pointers to instances of struct Trigger are stored in two ways.
- * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
+ * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
  *    database). This allows Trigger structures to be retrieved by name.
  * 2. All triggers associated with a single table form a linked list, using the
  *    pNext member of struct Trigger. A pointer to the first element of the
@@ -11023,7 +15659,7 @@ struct Trigger {
 
 /*
 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
-** determine which. 
+** determine which.
 **
 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
 ** In that cases, the constants below can be ORed together.
@@ -11033,50 +15669,50 @@ struct Trigger {
 
 /*
  * An instance of struct TriggerStep is used to store a single SQL statement
- * that is a part of a trigger-program. 
+ * that is a part of a trigger-program.
  *
  * Instances of struct TriggerStep are stored in a singly linked list (linked
- * using the "pNext" member) referenced by the "step_list" member of the 
+ * using the "pNext" member) referenced by the "step_list" member of the
  * associated struct Trigger instance. The first element of the linked list is
  * the first step of the trigger-program.
- * 
+ *
  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
- * "SELECT" statement. The meanings of the other members is determined by the 
+ * "SELECT" statement. The meanings of the other members is determined by the
  * value of "op" as follows:
  *
  * (op == TK_INSERT)
  * orconf    -> stores the ON CONFLICT algorithm
  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
  *              this stores a pointer to the SELECT statement. Otherwise NULL.
- * target    -> A token holding the quoted name of the table to insert into.
+ * zTarget   -> Dequoted name of the table to insert into.
  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
  *              this stores values to be inserted. Otherwise NULL.
- * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ... 
+ * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
  *              statement, then this stores the column-names to be
  *              inserted into.
  *
  * (op == TK_DELETE)
- * target    -> A token holding the quoted name of the table to delete from.
+ * zTarget   -> Dequoted name of the table to delete from.
  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
  *              Otherwise NULL.
- * 
+ *
  * (op == TK_UPDATE)
- * target    -> A token holding the quoted name of the table to update rows of.
+ * zTarget   -> Dequoted name of the table to update.
  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
  *              Otherwise NULL.
  * pExprList -> A list of the columns to update and the expressions to update
  *              them to. See sqlite3Update() documentation of "pChanges"
  *              argument.
- * 
+ *
  */
 struct TriggerStep {
   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
   u8 orconf;           /* OE_Rollback etc. */
   Trigger *pTrig;      /* The trigger that this step is a part of */
-  Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
-  Token target;        /* Target table for DELETE, UPDATE, INSERT */
+  Select *pSelect;     /* SELECT statement or RHS of INSERT INTO SELECT ... */
+  char *zTarget;       /* Target table for DELETE, UPDATE, INSERT */
   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
-  ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
+  ExprList *pExprList; /* SET clause for UPDATE. */
   IdList *pIdList;     /* Column names for INSERT */
   TriggerStep *pNext;  /* Next in the link-list */
   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
@@ -11085,11 +15721,13 @@ struct TriggerStep {
 /*
 ** The following structure contains information used by the sqliteFix...
 ** routines as they walk the parse tree to make database references
-** explicit.  
+** explicit.
 */
 typedef struct DbFixer DbFixer;
 struct DbFixer {
   Parse *pParse;      /* The parsing context.  Error messages written here */
+  Schema *pSchema;    /* Fix items to this schema */
+  int bVarOnly;       /* Check for variable references only */
   const char *zDb;    /* Make sure all objects are contained in this database */
   const char *zType;  /* Type of the container - used for error messages */
   const Token *pName; /* Name of the container - used for error messages */
@@ -11103,13 +15741,20 @@ struct StrAccum {
   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
   char *zBase;         /* A base allocation.  Not from malloc. */
   char *zText;         /* The string collected so far */
-  int  nChar;          /* Length of the string so far */
-  int  nAlloc;         /* Amount of space allocated in zText */
-  int  mxAlloc;        /* Maximum allowed string length */
-  u8   mallocFailed;   /* Becomes true if any memory allocation fails */
-  u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
-  u8   tooBig;         /* Becomes true if string size exceeds limits */
+  u32  nChar;          /* Length of the string so far */
+  u32  nAlloc;         /* Amount of space allocated in zText */
+  u32  mxAlloc;        /* Maximum allowed allocation.  0 for no malloc usage */
+  u8   accError;       /* STRACCUM_NOMEM or STRACCUM_TOOBIG */
+  u8   printfFlags;    /* SQLITE_PRINTF flags below */
 };
+#define STRACCUM_NOMEM   1
+#define STRACCUM_TOOBIG  2
+#define SQLITE_PRINTF_INTERNAL 0x01  /* Internal-use-only converters allowed */
+#define SQLITE_PRINTF_SQLFUNC  0x02  /* SQL function arguments to VXPrintf */
+#define SQLITE_PRINTF_MALLOCED 0x04  /* True if xText is allocated space */
+
+#define isMalloced(X)  (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)
+
 
 /*
 ** A pointer to this structure is used to communicate information
@@ -11117,8 +15762,8 @@ struct StrAccum {
 */
 typedef struct {
   sqlite3 *db;        /* The database being initialized */
-  int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
   char **pzErrMsg;    /* Error message stored here */
+  int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
   int rc;             /* Result code stored here */
 } InitData;
 
@@ -11132,15 +15777,20 @@ struct Sqlite3Config {
   int bCoreMutex;                   /* True to enable core mutexing */
   int bFullMutex;                   /* True to enable full mutexing */
   int bOpenUri;                     /* True to interpret filenames as URIs */
+  int bUseCis;                      /* Use covering indices for full-scans */
   int mxStrlen;                     /* Maximum string length */
+  int neverCorrupt;                 /* Database is always well-formed */
   int szLookaside;                  /* Default lookaside buffer size */
   int nLookaside;                   /* Default lookaside buffer count */
+  int nStmtSpill;                   /* Stmt-journal spill-to-disk threshold */
   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
-  sqlite3_pcache_methods pcache;    /* Low-level page-cache interface */
+  sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
   void *pHeap;                      /* Heap storage space */
   int nHeap;                        /* Size of pHeap[] */
   int mnReq, mxReq;                 /* Min and max heap requests sizes */
+  sqlite3_int64 szMmap;             /* mmap() space per open file */
+  sqlite3_int64 mxMmap;             /* Maximum value for szMmap */
   void *pScratch;                   /* Scratch memory */
   int szScratch;                    /* Size of each scratch buffer */
   int nScratch;                     /* Number of scratch buffers */
@@ -11149,6 +15799,7 @@ struct Sqlite3Config {
   int nPage;                        /* Number of pages in pPage[] */
   int mxParserStack;                /* maximum depth of the parser stack */
   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
+  u32 szPma;                        /* Maximum Sorter PMA size */
   /* The above might be initialized to non-zero.  The following need to always
   ** initially be zero, however. */
   int isInit;                       /* True after initialization has finished */
@@ -11156,23 +15807,64 @@ struct Sqlite3Config {
   int isMutexInit;                  /* True after mutexes are initialized */
   int isMallocInit;                 /* True after malloc is initialized */
   int isPCacheInit;                 /* True after malloc is initialized */
-  sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
   int nRefInitMutex;                /* Number of users of pInitMutex */
+  sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
   void (*xLog)(void*,int,const char*); /* Function for logging */
   void *pLogArg;                       /* First argument to xLog() */
+#ifdef SQLITE_ENABLE_SQLLOG
+  void(*xSqllog)(void*,sqlite3*,const char*, int);
+  void *pSqllogArg;
+#endif
+#ifdef SQLITE_VDBE_COVERAGE
+  /* The following callback (if not NULL) is invoked on every VDBE branch
+  ** operation.  Set the callback using SQLITE_TESTCTRL_VDBE_COVERAGE.
+  */
+  void (*xVdbeBranch)(void*,int iSrcLine,u8 eThis,u8 eMx);  /* Callback */
+  void *pVdbeBranchArg;                                     /* 1st argument */
+#endif
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+  int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
+#endif
   int bLocaltimeFault;              /* True to fail localtime() calls */
 };
 
 /*
+** This macro is used inside of assert() statements to indicate that
+** the assert is only valid on a well-formed database.  Instead of:
+**
+**     assert( X );
+**
+** One writes:
+**
+**     assert( X || CORRUPT_DB );
+**
+** CORRUPT_DB is true during normal operation.  CORRUPT_DB does not indicate
+** that the database is definitely corrupt, only that it might be corrupt.
+** For most test cases, CORRUPT_DB is set to false using a special
+** sqlite3_test_control().  This enables assert() statements to prove
+** things that are always true for well-formed databases.
+*/
+#define CORRUPT_DB  (sqlite3Config.neverCorrupt==0)
+
+/*
 ** Context pointer passed down through the tree-walk.
 */
 struct Walker {
+  Parse *pParse;                            /* Parser context.  */
   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
-  Parse *pParse;                            /* Parser context.  */
+  void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
+  int walkerDepth;                          /* Number of subqueries */
+  u8 eCode;                                 /* A small processing code */
   union {                                   /* Extra data for callback */
     NameContext *pNC;                          /* Naming context */
-    int i;                                     /* Integer value */
+    int n;                                     /* A counter */
+    int iCur;                                  /* A cursor number */
+    SrcList *pSrcList;                         /* FROM clause */
+    struct SrcCount *pSrcCount;                /* Counting column references */
+    struct CCurHint *pCCurHint;                /* Used by codeCursorHint() */
+    int *aiCol;                                /* array of column indexes */
+    struct IdxCover *pIdxCover;                /* Check for index coverage */
   } u;
 };
 
@@ -11182,6 +15874,7 @@ SQLITE_PRIVATE int sqlite3WalkExprList(Walker*, ExprList*);
 SQLITE_PRIVATE int sqlite3WalkSelect(Walker*, Select*);
 SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker*, Select*);
 SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker*, Select*);
+SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker*, Expr*);
 
 /*
 ** Return code from the parse-tree walking primitives and their
@@ -11192,6 +15885,32 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker*, Select*);
 #define WRC_Abort       2   /* Abandon the tree walk */
 
 /*
+** An instance of this structure represents a set of one or more CTEs
+** (common table expressions) created by a single WITH clause.
+*/
+struct With {
+  int nCte;                       /* Number of CTEs in the WITH clause */
+  With *pOuter;                   /* Containing WITH clause, or NULL */
+  struct Cte {                    /* For each CTE in the WITH clause.... */
+    char *zName;                    /* Name of this CTE */
+    ExprList *pCols;                /* List of explicit column names, or NULL */
+    Select *pSelect;                /* The definition of this CTE */
+    const char *zCteErr;            /* Error message for circular references */
+  } a[1];
+};
+
+#ifdef SQLITE_DEBUG
+/*
+** An instance of the TreeView object is used for printing the content of
+** data structures on sqlite3DebugPrintf() using a tree-like view.
+*/
+struct TreeView {
+  int iLevel;             /* Which level of the tree we are on */
+  u8  bLine[100];         /* Draw vertical in column i if bLine[i] is true */
+};
+#endif /* SQLITE_DEBUG */
+
+/*
 ** Assuming zIn points to the first byte of a UTF-8 character,
 ** advance zIn to point to the first byte of the next UTF-8 character.
 */
@@ -11214,15 +15933,31 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE   int sqlite3NomemError(int);
+SQLITE_PRIVATE   int sqlite3IoerrnomemError(int);
+# define SQLITE_NOMEM_BKPT sqlite3NomemError(__LINE__)
+# define SQLITE_IOERR_NOMEM_BKPT sqlite3IoerrnomemError(__LINE__)
+#else
+# define SQLITE_NOMEM_BKPT SQLITE_NOMEM
+# define SQLITE_IOERR_NOMEM_BKPT SQLITE_IOERR_NOMEM
+#endif
 
+/*
+** FTS3 and FTS4 both require virtual table support
+*/
+#if defined(SQLITE_OMIT_VIRTUALTABLE)
+# undef SQLITE_ENABLE_FTS3
+# undef SQLITE_ENABLE_FTS4
+#endif
 
 /*
 ** FTS4 is really an extension for FTS3.  It is enabled using the
-** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
-** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
+** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also call
+** the SQLITE_ENABLE_FTS4 macro to serve as an alias for SQLITE_ENABLE_FTS3.
 */
 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
-# define SQLITE_ENABLE_FTS3
+# define SQLITE_ENABLE_FTS3 1
 #endif
 
 /*
@@ -11247,6 +15982,7 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
+# define sqlite3Isquote(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x80)
 #else
 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
@@ -11255,26 +15991,32 @@ SQLITE_PRIVATE int sqlite3CantopenError(int);
 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
+# define sqlite3Isquote(x)   ((x)=='"'||(x)=='\''||(x)=='['||(x)=='`')
+#endif
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+SQLITE_PRIVATE int sqlite3IsIdChar(u8);
 #endif
 
 /*
 ** Internal function prototypes
 */
-SQLITE_PRIVATE int sqlite3StrICmp(const char *, const char *);
+SQLITE_PRIVATE int sqlite3StrICmp(const char*,const char*);
 SQLITE_PRIVATE int sqlite3Strlen30(const char*);
+SQLITE_PRIVATE char *sqlite3ColumnType(Column*,char*);
 #define sqlite3StrNICmp sqlite3_strnicmp
 
 SQLITE_PRIVATE int sqlite3MallocInit(void);
 SQLITE_PRIVATE void sqlite3MallocEnd(void);
-SQLITE_PRIVATE void *sqlite3Malloc(int);
-SQLITE_PRIVATE void *sqlite3MallocZero(int);
-SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, int);
-SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, int);
+SQLITE_PRIVATE void *sqlite3Malloc(u64);
+SQLITE_PRIVATE void *sqlite3MallocZero(u64);
+SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, u64);
+SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, u64);
+SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3*, u64);
 SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3*,const char*);
-SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, int);
-SQLITE_PRIVATE void *sqlite3Realloc(void*, int);
-SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
-SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, int);
+SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, u64);
+SQLITE_PRIVATE void *sqlite3Realloc(void*, u64);
+SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);
+SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, u64);
 SQLITE_PRIVATE void sqlite3DbFree(sqlite3*, void*);
 SQLITE_PRIVATE int sqlite3MallocSize(void*);
 SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3*, void*);
@@ -11283,7 +16025,9 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void*);
 SQLITE_PRIVATE void *sqlite3PageMalloc(int);
 SQLITE_PRIVATE void sqlite3PageFree(void*);
 SQLITE_PRIVATE void sqlite3MemSetDefault(void);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 SQLITE_PRIVATE void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
+#endif
 SQLITE_PRIVATE int sqlite3HeapNearlyFull(void);
 
 /*
@@ -11297,18 +16041,22 @@ SQLITE_PRIVATE int sqlite3HeapNearlyFull(void);
 #ifdef SQLITE_USE_ALLOCA
 # define sqlite3StackAllocRaw(D,N)   alloca(N)
 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
-# define sqlite3StackFree(D,P)       
+# define sqlite3StackFree(D,P)
 #else
 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
 #endif
 
-#ifdef SQLITE_ENABLE_MEMSYS3
-SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
-#endif
+/* Do not allow both MEMSYS5 and MEMSYS3 to be defined together.  If they
+** are, disable MEMSYS3
+*/
 #ifdef SQLITE_ENABLE_MEMSYS5
 SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
+#undef SQLITE_ENABLE_MEMSYS3
+#endif
+#ifdef SQLITE_ENABLE_MEMSYS3
+SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
 #endif
 
 
@@ -11319,10 +16067,20 @@ SQLITE_PRIVATE   sqlite3_mutex *sqlite3MutexAlloc(int);
 SQLITE_PRIVATE   int sqlite3MutexInit(void);
 SQLITE_PRIVATE   int sqlite3MutexEnd(void);
 #endif
+#if !defined(SQLITE_MUTEX_OMIT) && !defined(SQLITE_MUTEX_NOOP)
+SQLITE_PRIVATE   void sqlite3MemoryBarrier(void);
+#else
+# define sqlite3MemoryBarrier()
+#endif
+
+SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int);
+SQLITE_PRIVATE void sqlite3StatusUp(int, int);
+SQLITE_PRIVATE void sqlite3StatusDown(int, int);
+SQLITE_PRIVATE void sqlite3StatusHighwater(int, int);
 
-SQLITE_PRIVATE int sqlite3StatusValue(int);
-SQLITE_PRIVATE void sqlite3StatusAdd(int, int);
-SQLITE_PRIVATE void sqlite3StatusSet(int, int);
+/* Access to mutexes used by sqlite3_status() */
+SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void);
+SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void);
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
 SQLITE_PRIVATE   int sqlite3IsNaN(double);
@@ -11330,22 +16088,39 @@ SQLITE_PRIVATE   int sqlite3IsNaN(double);
 # define sqlite3IsNaN(X)  0
 #endif
 
-SQLITE_PRIVATE void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
-#ifndef SQLITE_OMIT_TRACE
+/*
+** An instance of the following structure holds information about SQL
+** functions arguments that are the parameters to the printf() function.
+*/
+struct PrintfArguments {
+  int nArg;                /* Total number of arguments */
+  int nUsed;               /* Number of arguments used so far */
+  sqlite3_value **apArg;   /* The argument values */
+};
+
+SQLITE_PRIVATE void sqlite3VXPrintf(StrAccum*, const char*, va_list);
 SQLITE_PRIVATE void sqlite3XPrintf(StrAccum*, const char*, ...);
-#endif
 SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3*,const char*, ...);
 SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
-SQLITE_PRIVATE char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
-#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
 SQLITE_PRIVATE   void sqlite3DebugPrintf(const char*, ...);
 #endif
 #if defined(SQLITE_TEST)
 SQLITE_PRIVATE   void *sqlite3TestTextToPtr(const char*);
 #endif
-SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*, ...);
+
+#if defined(SQLITE_DEBUG)
+SQLITE_PRIVATE   void sqlite3TreeViewExpr(TreeView*, const Expr*, u8);
+SQLITE_PRIVATE   void sqlite3TreeViewExprList(TreeView*, const ExprList*, u8, const char*);
+SQLITE_PRIVATE   void sqlite3TreeViewSelect(TreeView*, const Select*, u8);
+SQLITE_PRIVATE   void sqlite3TreeViewWith(TreeView*, const With*, u8);
+#endif
+
+
+SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);
 SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);
-SQLITE_PRIVATE int sqlite3Dequote(char*);
+SQLITE_PRIVATE void sqlite3Dequote(char*);
+SQLITE_PRIVATE void sqlite3TokenInit(Token*,char*);
 SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);
 SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, char **);
 SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);
@@ -11353,53 +16128,81 @@ SQLITE_PRIVATE int sqlite3GetTempReg(Parse*);
 SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);
 SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);
 SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);
+SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse*,int,int);
+#endif
 SQLITE_PRIVATE Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
 SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*,int,const char*);
 SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
 SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
+SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse*, Expr*, Select*);
 SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
 SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
 SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*);
 SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3*, Expr*);
 SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
+SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList*,int);
 SQLITE_PRIVATE void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
 SQLITE_PRIVATE void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
 SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);
+SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);
 SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
 SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
 SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
-SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3*, int);
-SQLITE_PRIVATE void sqlite3BeginParse(Parse*,int);
+SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3*);
+SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3*,int);
+SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3*);
 SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);
+SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3*,Table*);
+SQLITE_PRIVATE int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);
+SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(Parse*,Table*,Select*);
 SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,Select*);
 SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *, int);
+SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table*);
+SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index*, i16);
 SQLITE_PRIVATE void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
-SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*);
+#if SQLITE_ENABLE_HIDDEN_COLUMNS
+SQLITE_PRIVATE   void sqlite3ColumnPropertiesFromName(Table*, Column*);
+#else
+# define sqlite3ColumnPropertiesFromName(T,C) /* no-op */
+#endif
+SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*,Token*);
 SQLITE_PRIVATE void sqlite3AddNotNull(Parse*, int);
 SQLITE_PRIVATE void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
 SQLITE_PRIVATE void sqlite3AddCheckConstraint(Parse*, Expr*);
-SQLITE_PRIVATE void sqlite3AddColumnType(Parse*,Token*);
 SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse*,ExprSpan*);
 SQLITE_PRIVATE void sqlite3AddCollateType(Parse*, Token*);
-SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,Select*);
+SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,u8,Select*);
 SQLITE_PRIVATE int sqlite3ParseUri(const char*,const char*,unsigned int*,
                     sqlite3_vfs**,char**,char **);
+SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
+SQLITE_PRIVATE int sqlite3CodeOnce(Parse *);
+
+#ifdef SQLITE_OMIT_BUILTIN_TEST
+# define sqlite3FaultSim(X) SQLITE_OK
+#else
+SQLITE_PRIVATE   int sqlite3FaultSim(int);
+#endif
 
 SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32);
 SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec*, u32);
+SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec*, u32);
 SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec*, u32);
 SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec*, u32, void*);
 SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec*);
 SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec*);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int,int*);
+#endif
 
 SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
 SQLITE_PRIVATE void sqlite3RowSetClear(RowSet*);
 SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet*, i64);
-SQLITE_PRIVATE int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
+SQLITE_PRIVATE int sqlite3RowSetTest(RowSet*, int iBatch, i64);
 SQLITE_PRIVATE int sqlite3RowSetNext(RowSet*, i64*);
 
-SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
+SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,ExprList*,Select*,int,int);
 
 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
 SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
@@ -11407,6 +16210,9 @@ SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);
 # define sqlite3ViewGetColumnNames(A,B) 0
 #endif
 
+#if SQLITE_MAX_ATTACHED>30
+SQLITE_PRIVATE   int sqlite3DbMaskAllZero(yDbMask);
+#endif
 SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);
 SQLITE_PRIVATE void sqlite3CodeDropTable(Parse*, Table*, int, int);
 SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3*, Table*);
@@ -11417,8 +16223,8 @@ SQLITE_PRIVATE   void sqlite3AutoincrementEnd(Parse *pParse);
 # define sqlite3AutoincrementBegin(X)
 # define sqlite3AutoincrementEnd(X)
 #endif
-SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
-SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
+SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, Select*, IdList*, int);
+SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
 SQLITE_PRIVATE IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
 SQLITE_PRIVATE int sqlite3IdListIndex(IdList*,const char*);
 SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
@@ -11426,63 +16232,90 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*)
 SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                       Token*, Select*, Expr*, IdList*);
 SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
+SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);
 SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
 SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);
 SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);
 SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3*, IdList*);
 SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3*, SrcList*);
-SQLITE_PRIVATE Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
-                        Token*, int, int);
+SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);
+SQLITE_PRIVATE void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
+                          Expr*, int, int, u8);
 SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);
 SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*);
 SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
-                         Expr*,ExprList*,int,Expr*,Expr*);
+                         Expr*,ExprList*,u32,Expr*,Expr*);
 SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3*, Select*);
 SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);
 SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, int);
 SQLITE_PRIVATE void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
-SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
+SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
 #endif
 SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
 SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
-SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);
+SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
 SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);
-SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int);
+SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereOrderedInnerLoop(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo*);
+SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo*, int*);
+#define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */
+#define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */
+#define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */
+SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
+SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
+SQLITE_PRIVATE void sqlite3ExprCodeGetColumnToReg(Parse*, Table*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse*, int, int, int);
-SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse*, int, int, int);
 SQLITE_PRIVATE void sqlite3ExprCachePush(Parse*);
-SQLITE_PRIVATE void sqlite3ExprCachePop(Parse*, int);
+SQLITE_PRIVATE void sqlite3ExprCachePop(Parse*);
 SQLITE_PRIVATE void sqlite3ExprCacheRemove(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3ExprCacheClear(Parse*);
 SQLITE_PRIVATE void sqlite3ExprCacheAffinityChange(Parse*, int, int);
-SQLITE_PRIVATE int sqlite3ExprCode(Parse*, Expr*, int);
+SQLITE_PRIVATE void sqlite3ExprCode(Parse*, Expr*, int);
+SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse*, Expr*, int);
+SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
+SQLITE_PRIVATE void sqlite3ExprCodeAtInit(Parse*, Expr*, int, u8);
 SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
 SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse*, Expr*, int);
-SQLITE_PRIVATE int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
-SQLITE_PRIVATE void sqlite3ExprCodeConstants(Parse*, Expr*);
-SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
+SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse*, Expr*, int);
+SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
+#define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
+#define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
+#define SQLITE_ECEL_REF      0x04  /* Use ExprList.u.x.iOrderByCol */
 SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
 SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
+SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);
 SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3*,const char*, const char*);
-SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
+#define LOCATE_VIEW    0x01
+#define LOCATE_NOERR   0x02
+SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,u32 flags,const char*, const char*);
+SQLITE_PRIVATE Table *sqlite3LocateTableItem(Parse*,u32 flags,struct SrcList_item *);
 SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
 SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
 SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
 SQLITE_PRIVATE void sqlite3Vacuum(Parse*);
 SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*);
 SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3*, Token*);
-SQLITE_PRIVATE int sqlite3ExprCompare(Expr*, Expr*);
-SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList*, ExprList*);
+SQLITE_PRIVATE int sqlite3ExprCompare(Expr*, Expr*, int);
+SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList*, ExprList*, int);
+SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Expr*, Expr*, int);
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
+SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(Expr*, int iCur, Index *pIdx);
+SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
 SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse*);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 SQLITE_PRIVATE void sqlite3PrngSaveState(void);
 SQLITE_PRIVATE void sqlite3PrngRestoreState(void);
-SQLITE_PRIVATE void sqlite3PrngResetState(void);
-SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3*);
+#endif
+SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3*,int);
 SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse*, int);
 SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
 SQLITE_PRIVATE void sqlite3BeginTransaction(Parse*, int);
@@ -11490,35 +16323,48 @@ SQLITE_PRIVATE void sqlite3CommitTransaction(Parse*);
 SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse*);
 SQLITE_PRIVATE void sqlite3Savepoint(Parse*, int, Token*);
 SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *);
+SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
 SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr*);
 SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr*);
-SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*);
+SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*, u8);
+SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr*,int);
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr*);
+#endif
 SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr*, int*);
 SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr*);
-SQLITE_PRIVATE void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
 SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
 SQLITE_PRIVATE int sqlite3IsRowid(const char*);
-SQLITE_PRIVATE void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
-SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
-SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
-SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
-                                     int*,int,int,int,int,int*);
-SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
-SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
+SQLITE_PRIVATE void sqlite3GenerateRowDelete(
+    Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
+SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
+SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
+SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse*,int);
+SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
+                                     u8,u8,int,int*,int*);
+SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
+SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, u8, int, u8*, int*, int*);
 SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3MultiWrite(Parse*);
 SQLITE_PRIVATE void sqlite3MayAbort(Parse*);
-SQLITE_PRIVATE void sqlite3HaltConstraint(Parse*, int, char*, int);
+SQLITE_PRIVATE void sqlite3HaltConstraint(Parse*, int, int, char*, i8, u8);
+SQLITE_PRIVATE void sqlite3UniqueConstraint(Parse*, int, Index*);
+SQLITE_PRIVATE void sqlite3RowidConstraint(Parse*, int, Table*);
 SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
 SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
 SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
 SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3*,IdList*);
 SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3*,Select*,int);
-SQLITE_PRIVATE void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
-SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
-SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3*);
+#if SELECTTRACE_ENABLED
+SQLITE_PRIVATE void sqlite3SelectSetName(Select*,const char*);
+#else
+# define sqlite3SelectSetName(A,B)
+#endif
+SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(FuncDef*,int);
+SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,u8,u8);
+SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void);
 SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void);
-SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void);
+SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
 SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3*);
 SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3*);
 SQLITE_PRIVATE void sqlite3ChangeCookie(Parse*, int);
@@ -11542,13 +16388,14 @@ SQLITE_PRIVATE   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, i
 SQLITE_PRIVATE   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
 SQLITE_PRIVATE   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
 SQLITE_PRIVATE   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
-                                        ExprList*,Select*,u8);
+                                        Select*,u8);
 SQLITE_PRIVATE   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
 SQLITE_PRIVATE   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
 SQLITE_PRIVATE   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
 SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
 SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
+# define sqlite3IsToplevel(p) ((p)->pToplevel==0)
 #else
 # define sqlite3TriggersExist(B,C,D,E,F) 0
 # define sqlite3DeleteTrigger(A,B)
@@ -11558,6 +16405,7 @@ SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Tab
 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
 # define sqlite3TriggerList(X, Y) 0
 # define sqlite3ParseToplevel(p) p
+# define sqlite3IsToplevel(p) 1
 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
 #endif
 
@@ -11578,7 +16426,7 @@ SQLITE_PRIVATE   int sqlite3AuthReadCol(Parse*, const char *, const char *, int)
 #endif
 SQLITE_PRIVATE void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
 SQLITE_PRIVATE void sqlite3Detach(Parse*, Expr*);
-SQLITE_PRIVATE int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
+SQLITE_PRIVATE void sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
 SQLITE_PRIVATE int sqlite3FixSrcList(DbFixer*, SrcList*);
 SQLITE_PRIVATE int sqlite3FixSelect(DbFixer*, Select*);
 SQLITE_PRIVATE int sqlite3FixExpr(DbFixer*, Expr*);
@@ -11589,61 +16437,68 @@ SQLITE_PRIVATE int sqlite3GetInt32(const char *, int*);
 SQLITE_PRIVATE int sqlite3Atoi(const char*);
 SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *pData, int nChar);
 SQLITE_PRIVATE int sqlite3Utf8CharLen(const char *pData, int nByte);
-SQLITE_PRIVATE u32 sqlite3Utf8Read(const u8*, const u8**);
+SQLITE_PRIVATE u32 sqlite3Utf8Read(const u8**);
+SQLITE_PRIVATE LogEst sqlite3LogEst(u64);
+SQLITE_PRIVATE LogEst sqlite3LogEstAdd(LogEst,LogEst);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double);
+#endif
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
+SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst);
+#endif
 
 /*
 ** Routines to read and write variable-length integers.  These used to
 ** be defined locally, but now we use the varint routines in the util.c
-** file.  Code should use the MACRO forms below, as the Varint32 versions
-** are coded to assume the single byte case is already handled (which 
-** the MACRO form does).
+** file.
 */
 SQLITE_PRIVATE int sqlite3PutVarint(unsigned char*, u64);
-SQLITE_PRIVATE int sqlite3PutVarint32(unsigned char*, u32);
 SQLITE_PRIVATE u8 sqlite3GetVarint(const unsigned char *, u64 *);
 SQLITE_PRIVATE u8 sqlite3GetVarint32(const unsigned char *, u32 *);
 SQLITE_PRIVATE int sqlite3VarintLen(u64 v);
 
 /*
-** The header of a record consists of a sequence variable-length integers.
-** These integers are almost always small and are encoded as a single byte.
-** The following macros take advantage this fact to provide a fast encode
-** and decode of the integers in a record header.  It is faster for the common
-** case where the integer is a single byte.  It is a little slower when the
-** integer is two or more bytes.  But overall it is faster.
-**
-** The following expressions are equivalent:
-**
-**     x = sqlite3GetVarint32( A, &B );
-**     x = sqlite3PutVarint32( A, B );
-**
-**     x = getVarint32( A, B );
-**     x = putVarint32( A, B );
-**
+** The common case is for a varint to be a single byte.  They following
+** macros handle the common case without a procedure call, but then call
+** the procedure for larger varints.
 */
-#define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
-#define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
+#define getVarint32(A,B)  \
+  (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
+#define putVarint32(A,B)  \
+  (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
+  sqlite3PutVarint((A),(B)))
 #define getVarint    sqlite3GetVarint
 #define putVarint    sqlite3PutVarint
 
 
-SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
-SQLITE_PRIVATE void sqlite3TableAffinityStr(Vdbe *, Table *);
+SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3*, Index*);
+SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe*, Table*, int);
 SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2);
 SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
 SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr);
 SQLITE_PRIVATE int sqlite3Atoi64(const char*, i64*, int, u8);
-SQLITE_PRIVATE void sqlite3Error(sqlite3*, int, const char*,...);
+SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char*, i64*);
+SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3*, int, const char*,...);
+SQLITE_PRIVATE void sqlite3Error(sqlite3*,int);
+SQLITE_PRIVATE void sqlite3SystemError(sqlite3*,int);
 SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
 SQLITE_PRIVATE u8 sqlite3HexToInt(int h);
 SQLITE_PRIVATE int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
+
+#if defined(SQLITE_NEED_ERR_NAME)
+SQLITE_PRIVATE const char *sqlite3ErrName(int);
+#endif
+
 SQLITE_PRIVATE const char *sqlite3ErrStr(int);
 SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse);
 SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
 SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
 SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
-SQLITE_PRIVATE Expr *sqlite3ExprSetColl(Expr*, CollSeq*);
-SQLITE_PRIVATE Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
+SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
+SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
+SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr*);
 SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *, CollSeq *);
 SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *, const char *);
 SQLITE_PRIVATE void sqlite3VdbeSetChanges(sqlite3 *, int);
@@ -11656,27 +16511,26 @@ SQLITE_PRIVATE void sqlite3FileSuffix3(const char*, char*);
 #else
 # define sqlite3FileSuffix3(X,Y)
 #endif
-SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z);
+SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z,u8);
 
 SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);
 SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);
-SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
+SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
                         void(*)(void*));
+SQLITE_PRIVATE void sqlite3ValueSetNull(sqlite3_value*);
 SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);
 SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);
 SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
-#ifdef SQLITE_ENABLE_STAT3
-SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
-#endif
 SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
 SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
 #ifndef SQLITE_AMALGAMATION
 SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];
+SQLITE_PRIVATE const char sqlite3StrBINARY[];
 SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];
 SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[];
 SQLITE_PRIVATE const Token sqlite3IntTokens[];
 SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config;
-SQLITE_PRIVATE SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
+SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;
 #ifndef SQLITE_OMIT_WSD
 SQLITE_PRIVATE int sqlite3PendingByte;
 #endif
@@ -11690,14 +16544,18 @@ SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
 SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*);
 SQLITE_PRIVATE int sqlite3CodeSubselect(Parse *, Expr *, int, int);
 SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);
+SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
+SQLITE_PRIVATE int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
 SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);
+SQLITE_PRIVATE int sqlite3ResolveExprListNames(NameContext*, ExprList*);
 SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
+SQLITE_PRIVATE void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
 SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
 SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
 SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *, Token *);
 SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
-SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
-SQLITE_PRIVATE char sqlite3AffinityType(const char*);
+SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
+SQLITE_PRIVATE char sqlite3AffinityType(const char*, u8*);
 SQLITE_PRIVATE void sqlite3Analyze(Parse*, Token*, Token*);
 SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler*);
 SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);
@@ -11707,21 +16565,30 @@ SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3*,Index*);
 SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
 SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
 SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
-SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse*, int, int);
 SQLITE_PRIVATE void sqlite3SchemaClear(void *);
 SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
-SQLITE_PRIVATE KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
-SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);
+SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo*);
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo*);
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo*);
+#endif
+SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
   void (*)(sqlite3_context*,int,sqlite3_value **),
   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
   FuncDestructor *pDestructor
 );
+SQLITE_PRIVATE void sqlite3OomFault(sqlite3*);
+SQLITE_PRIVATE void sqlite3OomClear(sqlite3*);
 SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);
 SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);
 
-SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, char*, int, int);
+SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
 SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum*,const char*,int);
+SQLITE_PRIVATE void sqlite3StrAccumAppendAll(StrAccum*,const char*);
+SQLITE_PRIVATE void sqlite3AppendChar(StrAccum*,int,char);
 SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);
 SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum*);
 SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);
@@ -11730,10 +16597,18 @@ SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
 SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);
 SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
 
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void);
+SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(Parse*,Index*,UnpackedRecord**,Expr*,u8,int,int*);
+SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);
+SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);
+SQLITE_PRIVATE int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
+#endif
+
 /*
 ** The interface to the LEMON-generated parser
 */
-SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(size_t));
+SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(u64));
 SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));
 SQLITE_PRIVATE void sqlite3Parser(void*, int, Token, Parse*);
 #ifdef YYTRACKMAXSTACKDEPTH
@@ -11763,25 +16638,29 @@ SQLITE_PRIVATE   int sqlite3Utf8To8(unsigned char*);
 #  define sqlite3VtabRollback(X)
 #  define sqlite3VtabCommit(X)
 #  define sqlite3VtabInSync(db) 0
-#  define sqlite3VtabLock(X) 
+#  define sqlite3VtabLock(X)
 #  define sqlite3VtabUnlock(X)
 #  define sqlite3VtabUnlockList(X)
 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
 #else
 SQLITE_PRIVATE    void sqlite3VtabClear(sqlite3 *db, Table*);
-SQLITE_PRIVATE    int sqlite3VtabSync(sqlite3 *db, char **);
+SQLITE_PRIVATE    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
+SQLITE_PRIVATE    int sqlite3VtabSync(sqlite3 *db, Vdbe*);
 SQLITE_PRIVATE    int sqlite3VtabRollback(sqlite3 *db);
 SQLITE_PRIVATE    int sqlite3VtabCommit(sqlite3 *db);
 SQLITE_PRIVATE    void sqlite3VtabLock(VTable *);
 SQLITE_PRIVATE    void sqlite3VtabUnlock(VTable *);
 SQLITE_PRIVATE    void sqlite3VtabUnlockList(sqlite3*);
 SQLITE_PRIVATE    int sqlite3VtabSavepoint(sqlite3 *, int, int);
+SQLITE_PRIVATE    void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);
 SQLITE_PRIVATE    VTable *sqlite3GetVTable(sqlite3*, Table*);
 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
 #endif
+SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse*,Module*);
+SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3*,Module*);
 SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse*,Table*);
-SQLITE_PRIVATE void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
+SQLITE_PRIVATE void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
 SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse*, Token*);
 SQLITE_PRIVATE void sqlite3VtabArgInit(Parse*);
 SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse*, Token*);
@@ -11791,41 +16670,55 @@ SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
 SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *, VTable *);
 SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
 SQLITE_PRIVATE void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
+SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context*);
 SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
 SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
+SQLITE_PRIVATE void sqlite3ParserReset(Parse*);
 SQLITE_PRIVATE int sqlite3Reprepare(Vdbe*);
 SQLITE_PRIVATE void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
 SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
 SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3*);
 SQLITE_PRIVATE const char *sqlite3JournalModename(int);
-SQLITE_PRIVATE int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
-SQLITE_PRIVATE int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
+#ifndef SQLITE_OMIT_WAL
+SQLITE_PRIVATE   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
+SQLITE_PRIVATE   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
+#endif
+#ifndef SQLITE_OMIT_CTE
+SQLITE_PRIVATE   With *sqlite3WithAdd(Parse*,With*,Token*,ExprList*,Select*);
+SQLITE_PRIVATE   void sqlite3WithDelete(sqlite3*,With*);
+SQLITE_PRIVATE   void sqlite3WithPush(Parse*, With*, u8);
+#else
+#define sqlite3WithPush(x,y,z)
+#define sqlite3WithDelete(x,y)
+#endif
 
 /* Declarations for functions in fkey.c. All of these are replaced by
 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
 ** key functionality is available. If OMIT_TRIGGER is defined but
 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
-** this case foreign keys are parsed, but no other functionality is 
+** this case foreign keys are parsed, but no other functionality is
 ** provided (enforcement of FK constraints requires the triggers sub-system).
 */
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-SQLITE_PRIVATE   void sqlite3FkCheck(Parse*, Table*, int, int);
+SQLITE_PRIVATE   void sqlite3FkCheck(Parse*, Table*, int, int, int*, int);
 SQLITE_PRIVATE   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
-SQLITE_PRIVATE   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
+SQLITE_PRIVATE   void sqlite3FkActions(Parse*, Table*, ExprList*, int, int*, int);
 SQLITE_PRIVATE   int sqlite3FkRequired(Parse*, Table*, int*, int);
 SQLITE_PRIVATE   u32 sqlite3FkOldmask(Parse*, Table*);
 SQLITE_PRIVATE   FKey *sqlite3FkReferences(Table *);
 #else
-  #define sqlite3FkActions(a,b,c,d)
-  #define sqlite3FkCheck(a,b,c,d)
+  #define sqlite3FkActions(a,b,c,d,e,f)
+  #define sqlite3FkCheck(a,b,c,d,e,f)
   #define sqlite3FkDropTable(a,b,c)
-  #define sqlite3FkOldmask(a,b)      0
-  #define sqlite3FkRequired(a,b,c,d) 0
+  #define sqlite3FkOldmask(a,b)         0
+  #define sqlite3FkRequired(a,b,c,d)    0
 #endif
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 SQLITE_PRIVATE   void sqlite3FkDelete(sqlite3 *, Table*);
+SQLITE_PRIVATE   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
 #else
   #define sqlite3FkDelete(a,b)
+  #define sqlite3FkLocateIndex(a,b,c,d,e)
 #endif
 
 
@@ -11848,29 +16741,36 @@ SQLITE_PRIVATE   void sqlite3EndBenignMalloc(void);
   #define sqlite3EndBenignMalloc()
 #endif
 
-#define IN_INDEX_ROWID           1
-#define IN_INDEX_EPH             2
-#define IN_INDEX_INDEX           3
-SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, int*);
+/*
+** Allowed return values from sqlite3FindInIndex()
+*/
+#define IN_INDEX_ROWID        1   /* Search the rowid of the table */
+#define IN_INDEX_EPH          2   /* Search an ephemeral b-tree */
+#define IN_INDEX_INDEX_ASC    3   /* Existing index ASCENDING */
+#define IN_INDEX_INDEX_DESC   4   /* Existing index DESCENDING */
+#define IN_INDEX_NOOP         5   /* No table available. Use comparisons */
+/*
+** Allowed flags for the 3rd parameter to sqlite3FindInIndex().
+*/
+#define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
+#define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
+#define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
+SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*);
 
+SQLITE_PRIVATE int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
+SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *);
 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
-SQLITE_PRIVATE   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
-SQLITE_PRIVATE   int sqlite3JournalSize(sqlite3_vfs *);
 SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
-#else
-  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
 #endif
 
+SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p);
 SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *);
-SQLITE_PRIVATE int sqlite3MemJournalSize(void);
-SQLITE_PRIVATE int sqlite3IsMemJournal(sqlite3_file *);
 
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);
 #if SQLITE_MAX_EXPR_DEPTH>0
-SQLITE_PRIVATE   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
 SQLITE_PRIVATE   int sqlite3SelectExprHeight(Select *);
 SQLITE_PRIVATE   int sqlite3ExprCheckHeight(Parse*, int);
 #else
-  #define sqlite3ExprSetHeight(x,y)
   #define sqlite3SelectExprHeight(x) 0
   #define sqlite3ExprCheckHeight(x,y)
 #endif
@@ -11895,12 +16795,12 @@ SQLITE_PRIVATE   void sqlite3ParserTrace(FILE*, char *);
 /*
 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
 ** sqlite3IoTrace is a pointer to a printf-like routine used to
-** print I/O tracing messages. 
+** print I/O tracing messages.
 */
 #ifdef SQLITE_ENABLE_IOTRACE
 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
 SQLITE_PRIVATE   void sqlite3VdbeIOTraceSql(Vdbe*);
-SQLITE_PRIVATE void (*sqlite3IoTrace)(const char*,...);
+SQLITE_API SQLITE_EXTERN void (SQLITE_CDECL *sqlite3IoTrace)(const char*,...);
 #else
 # define IOTRACE(A)
 # define sqlite3VdbeIOTraceSql(X)
@@ -11929,7 +16829,7 @@ SQLITE_PRIVATE void (*sqlite3IoTrace)(const char*,...);
 ** that allocations that might have been satisfied by lookaside are not
 ** passed back to non-lookaside free() routines.  Asserts such as the
 ** example above are placed on the non-lookaside free() routines to verify
-** this constraint. 
+** this constraint.
 **
 ** All of this is no-op for a production build.  It only comes into
 ** play when the SQLITE_MEMDEBUG compile-time option is used.
@@ -11944,12 +16844,23 @@ SQLITE_PRIVATE   int sqlite3MemdebugNoType(void*,u8);
 # define sqlite3MemdebugNoType(X,Y)   1
 #endif
 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
-#define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
+#define MEMTYPE_LOOKASIDE  0x02  /* Heap that might have been lookaside */
 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
-#define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
 
-#endif /* _SQLITEINT_H_ */
+/*
+** Threading interface
+*/
+#if SQLITE_MAX_WORKER_THREADS>0
+SQLITE_PRIVATE int sqlite3ThreadCreate(SQLiteThread**,void*(*)(void*),void*);
+SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread*, void**);
+#endif
+
+#if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
+SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3*);
+#endif
+
+#endif /* SQLITEINT_H */
 
 /************** End of sqliteInt.h *******************************************/
 /************** Begin file global.c ******************************************/
@@ -11965,8 +16876,9 @@ SQLITE_PRIVATE   int sqlite3MemdebugNoType(void*,u8);
 **
 *************************************************************************
 **
-** This file contains definitions of global variables and contants.
+** This file contains definitions of global variables and constants.
 */
+/* #include "sqliteInt.h" */
 
 /* An array to map all upper-case characters into their corresponding
 ** lower-case character. 
@@ -12000,16 +16912,16 @@ SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {
      48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
      64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
      80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
-     96, 97, 66, 67, 68, 69, 70, 71, 72, 73,106,107,108,109,110,111, /* 6x */
-    112, 81, 82, 83, 84, 85, 86, 87, 88, 89,122,123,124,125,126,127, /* 7x */
+     96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111, /* 6x */
+    112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127, /* 7x */
     128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
-    144,145,146,147,148,149,150,151,152,153,154,155,156,157,156,159, /* 9x */
+    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159, /* 9x */
     160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
     176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
     192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
     208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
-    224,225,162,163,164,165,166,167,168,169,232,203,204,205,206,207, /* Ex */
-    239,240,241,242,243,244,245,246,247,248,249,219,220,221,222,255, /* Fx */
+    224,225,162,163,164,165,166,167,168,169,234,235,236,237,238,239, /* Ex */
+    240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255, /* Fx */
 #endif
 };
 
@@ -12024,6 +16936,7 @@ SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {
 **   isxdigit()                       0x08
 **   toupper()                        0x20
 **   SQLite identifier character      0x40
+**   Quote character                  0x80
 **
 ** Bit 0x20 is set if the mapped character requires translation to upper
 ** case. i.e. if the character is a lower-case ASCII character.
@@ -12049,7 +16962,7 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
   0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */
-  0x01, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,  /* 20..27     !"#$%&' */
+  0x01, 0x00, 0x80, 0x00, 0x40, 0x00, 0x00, 0x80,  /* 20..27     !"#$%&' */
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 28..2f    ()*+,-./ */
   0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,  /* 30..37    01234567 */
   0x0c, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 38..3f    89:;<=>? */
@@ -12057,8 +16970,8 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
   0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x02,  /* 40..47    @ABCDEFG */
   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 48..4f    HIJKLMNO */
   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 50..57    PQRSTUVW */
-  0x02, 0x02, 0x02, 0x00, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
-  0x00, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
+  0x02, 0x02, 0x02, 0x80, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
+  0x80, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 68..6f    hijklmno */
   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 70..77    pqrstuvw */
   0x22, 0x22, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 78..7f    xyz{|}~. */
@@ -12083,10 +16996,48 @@ SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {
 };
 #endif
 
+/* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards
+** compatibility for legacy applications, the URI filename capability is
+** disabled by default.
+**
+** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
+** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.
+**
+** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
+** disabled. The default value may be changed by compiling with the
+** SQLITE_USE_URI symbol defined.
+*/
 #ifndef SQLITE_USE_URI
 # define  SQLITE_USE_URI 0
 #endif
 
+/* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
+** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if
+** that compile-time option is omitted.
+*/
+#ifndef SQLITE_ALLOW_COVERING_INDEX_SCAN
+# define SQLITE_ALLOW_COVERING_INDEX_SCAN 1
+#endif
+
+/* The minimum PMA size is set to this value multiplied by the database
+** page size in bytes.
+*/
+#ifndef SQLITE_SORTER_PMASZ
+# define SQLITE_SORTER_PMASZ 250
+#endif
+
+/* Statement journals spill to disk when their size exceeds the following
+** threashold (in bytes). 0 means that statement journals are created and
+** written to disk immediately (the default behavior for SQLite versions
+** before 3.12.0).  -1 means always keep the entire statement journal in
+** memory.  (The statement journal is also always held entirely in memory
+** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this
+** setting.)
+*/
+#ifndef SQLITE_STMTJRNL_SPILL 
+# define SQLITE_STMTJRNL_SPILL (64*1024)
+#endif
+
 /*
 ** The following singleton contains the global configuration for
 ** the SQLite library.
@@ -12096,43 +17047,59 @@ SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
    1,                         /* bCoreMutex */
    SQLITE_THREADSAFE==1,      /* bFullMutex */
    SQLITE_USE_URI,            /* bOpenUri */
+   SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */
    0x7ffffffe,                /* mxStrlen */
+   0,                         /* neverCorrupt */
    128,                       /* szLookaside */
    500,                       /* nLookaside */
+   SQLITE_STMTJRNL_SPILL,     /* nStmtSpill */
    {0,0,0,0,0,0,0,0},         /* m */
    {0,0,0,0,0,0,0,0,0},       /* mutex */
-   {0,0,0,0,0,0,0,0,0,0,0},   /* pcache */
+   {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */
    (void*)0,                  /* pHeap */
    0,                         /* nHeap */
    0, 0,                      /* mnHeap, mxHeap */
+   SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
+   SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
    (void*)0,                  /* pScratch */
    0,                         /* szScratch */
    0,                         /* nScratch */
    (void*)0,                  /* pPage */
    0,                         /* szPage */
-   0,                         /* nPage */
+   SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */
    0,                         /* mxParserStack */
    0,                         /* sharedCacheEnabled */
+   SQLITE_SORTER_PMASZ,       /* szPma */
    /* All the rest should always be initialized to zero */
    0,                         /* isInit */
    0,                         /* inProgress */
    0,                         /* isMutexInit */
    0,                         /* isMallocInit */
    0,                         /* isPCacheInit */
-   0,                         /* pInitMutex */
    0,                         /* nRefInitMutex */
+   0,                         /* pInitMutex */
    0,                         /* xLog */
    0,                         /* pLogArg */
-   0,                         /* bLocaltimeFault */
+#ifdef SQLITE_ENABLE_SQLLOG
+   0,                         /* xSqllog */
+   0,                         /* pSqllogArg */
+#endif
+#ifdef SQLITE_VDBE_COVERAGE
+   0,                         /* xVdbeBranch */
+   0,                         /* pVbeBranchArg */
+#endif
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+   0,                         /* xTestCallback */
+#endif
+   0                          /* bLocaltimeFault */
 };
 
-
 /*
 ** Hash table for global functions - functions common to all
 ** database connections.  After initialization, this table is
 ** read-only.
 */
-SQLITE_PRIVATE SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
+SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;
 
 /*
 ** Constant tokens for values 0 and 1.
@@ -12158,13 +17125,14 @@ SQLITE_PRIVATE const Token sqlite3IntTokens[] = {
 **
 ** IMPORTANT:  Changing the pending byte to any value other than
 ** 0x40000000 results in an incompatible database file format!
-** Changing the pending byte during operating results in undefined
-** and dileterious behavior.
+** Changing the pending byte during operation will result in undefined
+** and incorrect behavior.
 */
 #ifndef SQLITE_OMIT_WSD
 SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;
 #endif
 
+/* #include "opcodes.h" */
 /*
 ** Properties of opcodes.  The OPFLG_INITIALIZER macro is
 ** created by mkopcodeh.awk during compilation.  Data is obtained
@@ -12173,6 +17141,11 @@ SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;
 */
 SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;
 
+/*
+** Name of the default collating sequence
+*/
+SQLITE_PRIVATE const char sqlite3StrBINARY[] = "BINARY";
+
 /************** End of global.c **********************************************/
 /************** Begin file ctime.c *******************************************/
 /*
@@ -12193,6 +17166,7 @@ SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;
 
 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
 
+/* #include "sqliteInt.h" */
 
 /*
 ** An array of names of all compile-time options.  This array should 
@@ -12209,333 +17183,375 @@ static const char * const azCompileOpt[] = {
 #define CTIMEOPT_VAL_(opt) #opt
 #define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt)
 
-#ifdef SQLITE_32BIT_ROWID
+#if SQLITE_32BIT_ROWID
   "32BIT_ROWID",
 #endif
-#ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
+#if SQLITE_4_BYTE_ALIGNED_MALLOC
   "4_BYTE_ALIGNED_MALLOC",
 #endif
-#ifdef SQLITE_CASE_SENSITIVE_LIKE
+#if SQLITE_CASE_SENSITIVE_LIKE
   "CASE_SENSITIVE_LIKE",
 #endif
-#ifdef SQLITE_CHECK_PAGES
+#if SQLITE_CHECK_PAGES
   "CHECK_PAGES",
 #endif
-#ifdef SQLITE_COVERAGE_TEST
+#if defined(__clang__) && defined(__clang_major__)
+  "COMPILER=clang-" CTIMEOPT_VAL(__clang_major__) "."
+                    CTIMEOPT_VAL(__clang_minor__) "."
+                    CTIMEOPT_VAL(__clang_patchlevel__),
+#elif defined(_MSC_VER)
+  "COMPILER=msvc-" CTIMEOPT_VAL(_MSC_VER),
+#elif defined(__GNUC__) && defined(__VERSION__)
+  "COMPILER=gcc-" __VERSION__,
+#endif
+#if SQLITE_COVERAGE_TEST
   "COVERAGE_TEST",
 #endif
-#ifdef SQLITE_DEBUG
+#if SQLITE_DEBUG
   "DEBUG",
 #endif
-#ifdef SQLITE_DEFAULT_LOCKING_MODE
+#if SQLITE_DEFAULT_LOCKING_MODE
   "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE),
 #endif
-#ifdef SQLITE_DISABLE_DIRSYNC
+#if defined(SQLITE_DEFAULT_MMAP_SIZE) && !defined(SQLITE_DEFAULT_MMAP_SIZE_xc)
+  "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),
+#endif
+#if SQLITE_DISABLE_DIRSYNC
   "DISABLE_DIRSYNC",
 #endif
-#ifdef SQLITE_DISABLE_LFS
+#if SQLITE_DISABLE_LFS
   "DISABLE_LFS",
 #endif
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+#if SQLITE_ENABLE_8_3_NAMES
+  "ENABLE_8_3_NAMES=" CTIMEOPT_VAL(SQLITE_ENABLE_8_3_NAMES),
+#endif
+#if SQLITE_ENABLE_API_ARMOR
+  "ENABLE_API_ARMOR",
+#endif
+#if SQLITE_ENABLE_ATOMIC_WRITE
   "ENABLE_ATOMIC_WRITE",
 #endif
-#ifdef SQLITE_ENABLE_CEROD
+#if SQLITE_ENABLE_CEROD
   "ENABLE_CEROD",
 #endif
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
+#if SQLITE_ENABLE_COLUMN_METADATA
   "ENABLE_COLUMN_METADATA",
 #endif
-#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
+#if SQLITE_ENABLE_DBSTAT_VTAB
+  "ENABLE_DBSTAT_VTAB",
+#endif
+#if SQLITE_ENABLE_EXPENSIVE_ASSERT
   "ENABLE_EXPENSIVE_ASSERT",
 #endif
-#ifdef SQLITE_ENABLE_FTS1
+#if SQLITE_ENABLE_FTS1
   "ENABLE_FTS1",
 #endif
-#ifdef SQLITE_ENABLE_FTS2
+#if SQLITE_ENABLE_FTS2
   "ENABLE_FTS2",
 #endif
-#ifdef SQLITE_ENABLE_FTS3
+#if SQLITE_ENABLE_FTS3
   "ENABLE_FTS3",
 #endif
-#ifdef SQLITE_ENABLE_FTS3_PARENTHESIS
+#if SQLITE_ENABLE_FTS3_PARENTHESIS
   "ENABLE_FTS3_PARENTHESIS",
 #endif
-#ifdef SQLITE_ENABLE_FTS4
+#if SQLITE_ENABLE_FTS4
   "ENABLE_FTS4",
 #endif
-#ifdef SQLITE_ENABLE_ICU
+#if SQLITE_ENABLE_FTS5
+  "ENABLE_FTS5",
+#endif
+#if SQLITE_ENABLE_ICU
   "ENABLE_ICU",
 #endif
-#ifdef SQLITE_ENABLE_IOTRACE
+#if SQLITE_ENABLE_IOTRACE
   "ENABLE_IOTRACE",
 #endif
-#ifdef SQLITE_ENABLE_LOAD_EXTENSION
+#if SQLITE_ENABLE_JSON1
+  "ENABLE_JSON1",
+#endif
+#if SQLITE_ENABLE_LOAD_EXTENSION
   "ENABLE_LOAD_EXTENSION",
 #endif
-#ifdef SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE
   "ENABLE_LOCKING_STYLE=" CTIMEOPT_VAL(SQLITE_ENABLE_LOCKING_STYLE),
 #endif
-#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+#if SQLITE_ENABLE_MEMORY_MANAGEMENT
   "ENABLE_MEMORY_MANAGEMENT",
 #endif
-#ifdef SQLITE_ENABLE_MEMSYS3
+#if SQLITE_ENABLE_MEMSYS3
   "ENABLE_MEMSYS3",
 #endif
-#ifdef SQLITE_ENABLE_MEMSYS5
+#if SQLITE_ENABLE_MEMSYS5
   "ENABLE_MEMSYS5",
 #endif
-#ifdef SQLITE_ENABLE_OVERSIZE_CELL_CHECK
+#if SQLITE_ENABLE_OVERSIZE_CELL_CHECK
   "ENABLE_OVERSIZE_CELL_CHECK",
 #endif
-#ifdef SQLITE_ENABLE_RTREE
+#if SQLITE_ENABLE_RTREE
   "ENABLE_RTREE",
 #endif
-#ifdef SQLITE_ENABLE_STAT3
+#if defined(SQLITE_ENABLE_STAT4)
+  "ENABLE_STAT4",
+#elif defined(SQLITE_ENABLE_STAT3)
   "ENABLE_STAT3",
 #endif
-#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
+#if SQLITE_ENABLE_UNLOCK_NOTIFY
   "ENABLE_UNLOCK_NOTIFY",
 #endif
-#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
+#if SQLITE_ENABLE_UPDATE_DELETE_LIMIT
   "ENABLE_UPDATE_DELETE_LIMIT",
 #endif
-#ifdef SQLITE_HAS_CODEC
+#if SQLITE_HAS_CODEC
   "HAS_CODEC",
 #endif
-#ifdef SQLITE_HAVE_ISNAN
+#if HAVE_ISNAN || SQLITE_HAVE_ISNAN
   "HAVE_ISNAN",
 #endif
-#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+#if SQLITE_HOMEGROWN_RECURSIVE_MUTEX
   "HOMEGROWN_RECURSIVE_MUTEX",
 #endif
-#ifdef SQLITE_IGNORE_AFP_LOCK_ERRORS
+#if SQLITE_IGNORE_AFP_LOCK_ERRORS
   "IGNORE_AFP_LOCK_ERRORS",
 #endif
-#ifdef SQLITE_IGNORE_FLOCK_LOCK_ERRORS
+#if SQLITE_IGNORE_FLOCK_LOCK_ERRORS
   "IGNORE_FLOCK_LOCK_ERRORS",
 #endif
 #ifdef SQLITE_INT64_TYPE
   "INT64_TYPE",
 #endif
-#ifdef SQLITE_LOCK_TRACE
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  "LIKE_DOESNT_MATCH_BLOBS",
+#endif
+#if SQLITE_LOCK_TRACE
   "LOCK_TRACE",
 #endif
+#if defined(SQLITE_MAX_MMAP_SIZE) && !defined(SQLITE_MAX_MMAP_SIZE_xc)
+  "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),
+#endif
 #ifdef SQLITE_MAX_SCHEMA_RETRY
   "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
 #endif
-#ifdef SQLITE_MEMDEBUG
+#if SQLITE_MEMDEBUG
   "MEMDEBUG",
 #endif
-#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
+#if SQLITE_MIXED_ENDIAN_64BIT_FLOAT
   "MIXED_ENDIAN_64BIT_FLOAT",
 #endif
-#ifdef SQLITE_NO_SYNC
+#if SQLITE_NO_SYNC
   "NO_SYNC",
 #endif
-#ifdef SQLITE_OMIT_ALTERTABLE
+#if SQLITE_OMIT_ALTERTABLE
   "OMIT_ALTERTABLE",
 #endif
-#ifdef SQLITE_OMIT_ANALYZE
+#if SQLITE_OMIT_ANALYZE
   "OMIT_ANALYZE",
 #endif
-#ifdef SQLITE_OMIT_ATTACH
+#if SQLITE_OMIT_ATTACH
   "OMIT_ATTACH",
 #endif
-#ifdef SQLITE_OMIT_AUTHORIZATION
+#if SQLITE_OMIT_AUTHORIZATION
   "OMIT_AUTHORIZATION",
 #endif
-#ifdef SQLITE_OMIT_AUTOINCREMENT
+#if SQLITE_OMIT_AUTOINCREMENT
   "OMIT_AUTOINCREMENT",
 #endif
-#ifdef SQLITE_OMIT_AUTOINIT
+#if SQLITE_OMIT_AUTOINIT
   "OMIT_AUTOINIT",
 #endif
-#ifdef SQLITE_OMIT_AUTOMATIC_INDEX
+#if SQLITE_OMIT_AUTOMATIC_INDEX
   "OMIT_AUTOMATIC_INDEX",
 #endif
-#ifdef SQLITE_OMIT_AUTORESET
+#if SQLITE_OMIT_AUTORESET
   "OMIT_AUTORESET",
 #endif
-#ifdef SQLITE_OMIT_AUTOVACUUM
+#if SQLITE_OMIT_AUTOVACUUM
   "OMIT_AUTOVACUUM",
 #endif
-#ifdef SQLITE_OMIT_BETWEEN_OPTIMIZATION
+#if SQLITE_OMIT_BETWEEN_OPTIMIZATION
   "OMIT_BETWEEN_OPTIMIZATION",
 #endif
-#ifdef SQLITE_OMIT_BLOB_LITERAL
+#if SQLITE_OMIT_BLOB_LITERAL
   "OMIT_BLOB_LITERAL",
 #endif
-#ifdef SQLITE_OMIT_BTREECOUNT
+#if SQLITE_OMIT_BTREECOUNT
   "OMIT_BTREECOUNT",
 #endif
-#ifdef SQLITE_OMIT_BUILTIN_TEST
+#if SQLITE_OMIT_BUILTIN_TEST
   "OMIT_BUILTIN_TEST",
 #endif
-#ifdef SQLITE_OMIT_CAST
+#if SQLITE_OMIT_CAST
   "OMIT_CAST",
 #endif
-#ifdef SQLITE_OMIT_CHECK
+#if SQLITE_OMIT_CHECK
   "OMIT_CHECK",
 #endif
-/* // redundant
-** #ifdef SQLITE_OMIT_COMPILEOPTION_DIAGS
-**   "OMIT_COMPILEOPTION_DIAGS",
-** #endif
-*/
-#ifdef SQLITE_OMIT_COMPLETE
+#if SQLITE_OMIT_COMPLETE
   "OMIT_COMPLETE",
 #endif
-#ifdef SQLITE_OMIT_COMPOUND_SELECT
+#if SQLITE_OMIT_COMPOUND_SELECT
   "OMIT_COMPOUND_SELECT",
 #endif
-#ifdef SQLITE_OMIT_DATETIME_FUNCS
+#if SQLITE_OMIT_CTE
+  "OMIT_CTE",
+#endif
+#if SQLITE_OMIT_DATETIME_FUNCS
   "OMIT_DATETIME_FUNCS",
 #endif
-#ifdef SQLITE_OMIT_DECLTYPE
+#if SQLITE_OMIT_DECLTYPE
   "OMIT_DECLTYPE",
 #endif
-#ifdef SQLITE_OMIT_DEPRECATED
+#if SQLITE_OMIT_DEPRECATED
   "OMIT_DEPRECATED",
 #endif
-#ifdef SQLITE_OMIT_DISKIO
+#if SQLITE_OMIT_DISKIO
   "OMIT_DISKIO",
 #endif
-#ifdef SQLITE_OMIT_EXPLAIN
+#if SQLITE_OMIT_EXPLAIN
   "OMIT_EXPLAIN",
 #endif
-#ifdef SQLITE_OMIT_FLAG_PRAGMAS
+#if SQLITE_OMIT_FLAG_PRAGMAS
   "OMIT_FLAG_PRAGMAS",
 #endif
-#ifdef SQLITE_OMIT_FLOATING_POINT
+#if SQLITE_OMIT_FLOATING_POINT
   "OMIT_FLOATING_POINT",
 #endif
-#ifdef SQLITE_OMIT_FOREIGN_KEY
+#if SQLITE_OMIT_FOREIGN_KEY
   "OMIT_FOREIGN_KEY",
 #endif
-#ifdef SQLITE_OMIT_GET_TABLE
+#if SQLITE_OMIT_GET_TABLE
   "OMIT_GET_TABLE",
 #endif
-#ifdef SQLITE_OMIT_INCRBLOB
+#if SQLITE_OMIT_INCRBLOB
   "OMIT_INCRBLOB",
 #endif
-#ifdef SQLITE_OMIT_INTEGRITY_CHECK
+#if SQLITE_OMIT_INTEGRITY_CHECK
   "OMIT_INTEGRITY_CHECK",
 #endif
-#ifdef SQLITE_OMIT_LIKE_OPTIMIZATION
+#if SQLITE_OMIT_LIKE_OPTIMIZATION
   "OMIT_LIKE_OPTIMIZATION",
 #endif
-#ifdef SQLITE_OMIT_LOAD_EXTENSION
+#if SQLITE_OMIT_LOAD_EXTENSION
   "OMIT_LOAD_EXTENSION",
 #endif
-#ifdef SQLITE_OMIT_LOCALTIME
+#if SQLITE_OMIT_LOCALTIME
   "OMIT_LOCALTIME",
 #endif
-#ifdef SQLITE_OMIT_LOOKASIDE
+#if SQLITE_OMIT_LOOKASIDE
   "OMIT_LOOKASIDE",
 #endif
-#ifdef SQLITE_OMIT_MEMORYDB
+#if SQLITE_OMIT_MEMORYDB
   "OMIT_MEMORYDB",
 #endif
-#ifdef SQLITE_OMIT_MERGE_SORT
-  "OMIT_MERGE_SORT",
-#endif
-#ifdef SQLITE_OMIT_OR_OPTIMIZATION
+#if SQLITE_OMIT_OR_OPTIMIZATION
   "OMIT_OR_OPTIMIZATION",
 #endif
-#ifdef SQLITE_OMIT_PAGER_PRAGMAS
+#if SQLITE_OMIT_PAGER_PRAGMAS
   "OMIT_PAGER_PRAGMAS",
 #endif
-#ifdef SQLITE_OMIT_PRAGMA
+#if SQLITE_OMIT_PRAGMA
   "OMIT_PRAGMA",
 #endif
-#ifdef SQLITE_OMIT_PROGRESS_CALLBACK
+#if SQLITE_OMIT_PROGRESS_CALLBACK
   "OMIT_PROGRESS_CALLBACK",
 #endif
-#ifdef SQLITE_OMIT_QUICKBALANCE
+#if SQLITE_OMIT_QUICKBALANCE
   "OMIT_QUICKBALANCE",
 #endif
-#ifdef SQLITE_OMIT_REINDEX
+#if SQLITE_OMIT_REINDEX
   "OMIT_REINDEX",
 #endif
-#ifdef SQLITE_OMIT_SCHEMA_PRAGMAS
+#if SQLITE_OMIT_SCHEMA_PRAGMAS
   "OMIT_SCHEMA_PRAGMAS",
 #endif
-#ifdef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
+#if SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
   "OMIT_SCHEMA_VERSION_PRAGMAS",
 #endif
-#ifdef SQLITE_OMIT_SHARED_CACHE
+#if SQLITE_OMIT_SHARED_CACHE
   "OMIT_SHARED_CACHE",
 #endif
-#ifdef SQLITE_OMIT_SUBQUERY
+#if SQLITE_OMIT_SUBQUERY
   "OMIT_SUBQUERY",
 #endif
-#ifdef SQLITE_OMIT_TCL_VARIABLE
+#if SQLITE_OMIT_TCL_VARIABLE
   "OMIT_TCL_VARIABLE",
 #endif
-#ifdef SQLITE_OMIT_TEMPDB
+#if SQLITE_OMIT_TEMPDB
   "OMIT_TEMPDB",
 #endif
-#ifdef SQLITE_OMIT_TRACE
+#if SQLITE_OMIT_TRACE
   "OMIT_TRACE",
 #endif
-#ifdef SQLITE_OMIT_TRIGGER
+#if SQLITE_OMIT_TRIGGER
   "OMIT_TRIGGER",
 #endif
-#ifdef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
+#if SQLITE_OMIT_TRUNCATE_OPTIMIZATION
   "OMIT_TRUNCATE_OPTIMIZATION",
 #endif
-#ifdef SQLITE_OMIT_UTF16
+#if SQLITE_OMIT_UTF16
   "OMIT_UTF16",
 #endif
-#ifdef SQLITE_OMIT_VACUUM
+#if SQLITE_OMIT_VACUUM
   "OMIT_VACUUM",
 #endif
-#ifdef SQLITE_OMIT_VIEW
+#if SQLITE_OMIT_VIEW
   "OMIT_VIEW",
 #endif
-#ifdef SQLITE_OMIT_VIRTUALTABLE
+#if SQLITE_OMIT_VIRTUALTABLE
   "OMIT_VIRTUALTABLE",
 #endif
-#ifdef SQLITE_OMIT_WAL
+#if SQLITE_OMIT_WAL
   "OMIT_WAL",
 #endif
-#ifdef SQLITE_OMIT_WSD
+#if SQLITE_OMIT_WSD
   "OMIT_WSD",
 #endif
-#ifdef SQLITE_OMIT_XFER_OPT
+#if SQLITE_OMIT_XFER_OPT
   "OMIT_XFER_OPT",
 #endif
-#ifdef SQLITE_PERFORMANCE_TRACE
+#if SQLITE_PERFORMANCE_TRACE
   "PERFORMANCE_TRACE",
 #endif
-#ifdef SQLITE_PROXY_DEBUG
+#if SQLITE_PROXY_DEBUG
   "PROXY_DEBUG",
 #endif
-#ifdef SQLITE_SECURE_DELETE
+#if SQLITE_RTREE_INT_ONLY
+  "RTREE_INT_ONLY",
+#endif
+#if SQLITE_SECURE_DELETE
   "SECURE_DELETE",
 #endif
-#ifdef SQLITE_SMALL_STACK
+#if SQLITE_SMALL_STACK
   "SMALL_STACK",
 #endif
-#ifdef SQLITE_SOUNDEX
+#if SQLITE_SOUNDEX
   "SOUNDEX",
 #endif
-#ifdef SQLITE_TCL
+#if SQLITE_SYSTEM_MALLOC
+  "SYSTEM_MALLOC",
+#endif
+#if SQLITE_TCL
   "TCL",
 #endif
-#ifdef SQLITE_TEMP_STORE
+#if defined(SQLITE_TEMP_STORE) && !defined(SQLITE_TEMP_STORE_xc)
   "TEMP_STORE=" CTIMEOPT_VAL(SQLITE_TEMP_STORE),
 #endif
-#ifdef SQLITE_TEST
+#if SQLITE_TEST
   "TEST",
 #endif
-#ifdef SQLITE_THREADSAFE
+#if defined(SQLITE_THREADSAFE)
   "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE),
 #endif
-#ifdef SQLITE_USE_ALLOCA
+#if SQLITE_USE_ALLOCA
   "USE_ALLOCA",
 #endif
-#ifdef SQLITE_ZERO_MALLOC
+#if SQLITE_USER_AUTHENTICATION
+  "USER_AUTHENTICATION",
+#endif
+#if SQLITE_WIN32_MALLOC
+  "WIN32_MALLOC",
+#endif
+#if SQLITE_ZERO_MALLOC
   "ZERO_MALLOC"
 #endif
 };
@@ -12547,16 +17563,26 @@ static const char * const azCompileOpt[] = {
 ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
 ** is not required for a match.
 */
-SQLITE_API int sqlite3_compileoption_used(const char *zOptName){
+SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName){
   int i, n;
+
+#if SQLITE_ENABLE_API_ARMOR
+  if( zOptName==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
   n = sqlite3Strlen30(zOptName);
 
   /* Since ArraySize(azCompileOpt) is normally in single digits, a
   ** linear search is adequate.  No need for a binary search. */
   for(i=0; i<ArraySize(azCompileOpt); i++){
-    if(   (sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0)
-       && ( (azCompileOpt[i][n]==0) || (azCompileOpt[i][n]=='=') ) ) return 1;
+    if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
+     && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
+    ){
+      return 1;
+    }
   }
   return 0;
 }
@@ -12565,7 +17591,7 @@ SQLITE_API int sqlite3_compileoption_used(const char *zOptName){
 ** Return the N-th compile-time option string.  If N is out of range,
 ** return a NULL pointer.
 */
-SQLITE_API const char *sqlite3_compileoption_get(int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N){
   if( N>=0 && N<ArraySize(azCompileOpt) ){
     return azCompileOpt[N];
   }
@@ -12591,6 +17617,7 @@ SQLITE_API const char *sqlite3_compileoption_get(int N){
 ** This module implements the sqlite3_status() interface and related
 ** functionality.
 */
+/* #include "sqliteInt.h" */
 /************** Include vdbeInt.h in the middle of status.c ******************/
 /************** Begin file vdbeInt.h *****************************************/
 /*
@@ -12610,8 +17637,27 @@ SQLITE_API const char *sqlite3_compileoption_get(int N){
 ** 6000 lines long) it was split up into several smaller files and
 ** this header information was factored out.
 */
-#ifndef _VDBEINT_H_
-#define _VDBEINT_H_
+#ifndef SQLITE_VDBEINT_H
+#define SQLITE_VDBEINT_H
+
+/*
+** The maximum number of times that a statement will try to reparse
+** itself before giving up and returning SQLITE_SCHEMA.
+*/
+#ifndef SQLITE_MAX_SCHEMA_RETRY
+# define SQLITE_MAX_SCHEMA_RETRY 50
+#endif
+
+/*
+** VDBE_DISPLAY_P4 is true or false depending on whether or not the
+** "explain" P4 display logic is enabled.
+*/
+#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
+     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+# define VDBE_DISPLAY_P4 1
+#else
+# define VDBE_DISPLAY_P4 0
+#endif
 
 /*
 ** SQL is translated into a sequence of instructions to be
@@ -12623,48 +17669,66 @@ typedef struct VdbeOp Op;
 /*
 ** Boolean values
 */
-typedef unsigned char Bool;
+typedef unsigned Bool;
 
 /* Opaque type used by code in vdbesort.c */
 typedef struct VdbeSorter VdbeSorter;
 
+/* Opaque type used by the explainer */
+typedef struct Explain Explain;
+
+/* Elements of the linked list at Vdbe.pAuxData */
+typedef struct AuxData AuxData;
+
+/* Types of VDBE cursors */
+#define CURTYPE_BTREE       0
+#define CURTYPE_SORTER      1
+#define CURTYPE_VTAB        2
+#define CURTYPE_PSEUDO      3
+
 /*
-** A cursor is a pointer into a single BTree within a database file.
-** The cursor can seek to a BTree entry with a particular key, or
-** loop over all entries of the Btree.  You can also insert new BTree
-** entries or retrieve the key or data from the entry that the cursor
-** is currently pointing to.
-** 
-** Every cursor that the virtual machine has open is represented by an
-** instance of the following structure.
+** A VdbeCursor is an superclass (a wrapper) for various cursor objects:
+**
+**      * A b-tree cursor
+**          -  In the main database or in an ephemeral database
+**          -  On either an index or a table
+**      * A sorter
+**      * A virtual table
+**      * A one-row "pseudotable" stored in a single register
 */
+typedef struct VdbeCursor VdbeCursor;
 struct VdbeCursor {
-  BtCursor *pCursor;    /* The cursor structure of the backend */
+  u8 eCurType;          /* One of the CURTYPE_* values above */
+  i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
+  u8 nullRow;           /* True if pointing to a row with no data */
+  u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */
+  u8 isTable;           /* True for rowid tables.  False for indexes */
+#ifdef SQLITE_DEBUG
+  u8 seekOp;            /* Most recent seek operation on this cursor */
+  u8 wrFlag;            /* The wrFlag argument to sqlite3BtreeCursor() */
+#endif
+  Bool isEphemeral:1;   /* True for an ephemeral table */
+  Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
+  Bool isOrdered:1;     /* True if the table is not BTREE_UNORDERED */
+  Pgno pgnoRoot;        /* Root page of the open btree cursor */
+  i16 nField;           /* Number of fields in the header */
+  u16 nHdrParsed;       /* Number of header fields parsed so far */
+  union {
+    BtCursor *pCursor;          /* CURTYPE_BTREE.  Btree cursor */
+    sqlite3_vtab_cursor *pVCur; /* CURTYPE_VTAB.   Vtab cursor */
+    int pseudoTableReg;         /* CURTYPE_PSEUDO. Reg holding content. */
+    VdbeSorter *pSorter;        /* CURTYPE_SORTER. Sorter object */
+  } uc;
   Btree *pBt;           /* Separate file holding temporary table */
   KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
-  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
-  int pseudoTableReg;   /* Register holding pseudotable content. */
-  int nField;           /* Number of fields in the header */
-  Bool zeroed;          /* True if zeroed out and ready for reuse */
-  Bool rowidIsValid;    /* True if lastRowid is valid */
-  Bool atFirst;         /* True if pointing to first entry */
-  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
-  Bool nullRow;         /* True if pointing to a row with no data */
-  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
-  Bool isTable;         /* True if a table requiring integer keys */
-  Bool isIndex;         /* True if an index containing keys only - no data */
-  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
-  Bool isSorter;        /* True if a new-style sorter */
-  sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
-  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
+  int seekResult;       /* Result of previous sqlite3BtreeMoveto() */
   i64 seqCount;         /* Sequence counter */
   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
-  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
-  VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
-
-  /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or 
-  ** OP_IsUnique opcode on this cursor. */
-  int seekResult;
+  VdbeCursor *pAltCursor; /* Associated index cursor from which to read */
+  int *aAltMap;           /* Mapping from table to index column numbers */
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+  u64 maskUsed;         /* Mask of columns used by this cursor */
+#endif
 
   /* Cached information about the header for the data record that the
   ** cursor is currently pointing to.  Only valid if cacheStatus matches
@@ -12676,12 +17740,16 @@ struct VdbeCursor {
   ** be NULL.
   */
   u32 cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
-  int payloadSize;      /* Total number of bytes in the record */
-  u32 *aType;           /* Type values for all entries in the record */
-  u32 *aOffset;         /* Cached offsets to the start of each columns data */
-  u8 *aRow;             /* Data for the current row, if all on one page */
+  u32 payloadSize;      /* Total number of bytes in the record */
+  u32 szRow;            /* Byte available in aRow */
+  u32 iHdrOffset;       /* Offset to next unparsed byte of the header */
+  const u8 *aRow;       /* Data for the current row, if all on one page */
+  u32 *aOffset;         /* Pointer to aType[nField] */
+  u32 aType[1];         /* Type values for all entries in the record */
+  /* 2*nField extra array elements allocated for aType[], beyond the one
+  ** static element declared in the structure.  nField total array slots for
+  ** aType[] and nField+1 array slots for aOffset[] */
 };
-typedef struct VdbeCursor VdbeCursor;
 
 /*
 ** When a sub-program is executed (OP_Program), a structure of this type
@@ -12707,19 +17775,24 @@ typedef struct VdbeCursor VdbeCursor;
 typedef struct VdbeFrame VdbeFrame;
 struct VdbeFrame {
   Vdbe *v;                /* VM this frame belongs to */
-  int pc;                 /* Program Counter in parent (calling) frame */
+  VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
   Op *aOp;                /* Program instructions for parent frame */
-  int nOp;                /* Size of aOp array */
+  i64 *anExec;            /* Event counters from parent frame */
   Mem *aMem;              /* Array of memory cells for parent frame */
-  int nMem;               /* Number of entries in aMem */
+  u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
-  u16 nCursor;            /* Number of entries in apCsr */
   void *token;            /* Copy of SubProgram.token */
+  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
+  AuxData *pAuxData;      /* Linked list of auxdata allocations */
+  int nCursor;            /* Number of entries in apCsr */
+  int pc;                 /* Program Counter in parent (calling) frame */
+  int nOp;                /* Size of aOp array */
+  int nMem;               /* Number of entries in aMem */
+  int nOnceFlag;          /* Number of entries in aOnceFlag */
   int nChildMem;          /* Number of memory cells for child frame */
   int nChildCsr;          /* Number of cursors for child frame */
-  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
-  int nChange;            /* Statement changes (Vdbe.nChanges)     */
-  VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
+  int nChange;            /* Statement changes (Vdbe.nChange)     */
+  int nDbChange;          /* Value of db->nChange */
 };
 
 #define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])
@@ -12735,28 +17808,37 @@ struct VdbeFrame {
 ** integer etc.) of the same value.
 */
 struct Mem {
-  sqlite3 *db;        /* The associated database connection */
-  char *z;            /* String or BLOB value */
-  double r;           /* Real value */
-  union {
+  union MemValue {
+    double r;           /* Real value used when MEM_Real is set in flags */
     i64 i;              /* Integer value used when MEM_Int is set in flags */
     int nZero;          /* Used when bit MEM_Zero is set in flags */
     FuncDef *pDef;      /* Used only when flags==MEM_Agg */
     RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
     VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
   } u;
-  int n;              /* Number of characters in string value, excluding '\0' */
   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
-  u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
+  u8  eSubtype;       /* Subtype for this value */
+  int n;              /* Number of characters in string value, excluding '\0' */
+  char *z;            /* String or BLOB value */
+  /* ShallowCopy only needs to copy the information above */
+  char *zMalloc;      /* Space to hold MEM_Str or MEM_Blob if szMalloc>0 */
+  int szMalloc;       /* Size of the zMalloc allocation */
+  u32 uTemp;          /* Transient storage for serial_type in OP_MakeRecord */
+  sqlite3 *db;        /* The associated database connection */
+  void (*xDel)(void*);/* Destructor for Mem.z - only valid if MEM_Dyn */
 #ifdef SQLITE_DEBUG
   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
   void *pFiller;      /* So that sizeof(Mem) is a multiple of 8 */
 #endif
-  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
-  char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
 };
 
+/*
+** Size of struct Mem not including the Mem.zMalloc member or anything that
+** follows.
+*/
+#define MEMCELLSIZE offsetof(Mem,zMalloc)
+
 /* One or more of the following flags are set to indicate the validOK
 ** representations of the value stored in the Mem struct.
 **
@@ -12774,10 +17856,13 @@ struct Mem {
 #define MEM_Int       0x0004   /* Value is an integer */
 #define MEM_Real      0x0008   /* Value is a real number */
 #define MEM_Blob      0x0010   /* Value is a BLOB */
+#define MEM_AffMask   0x001f   /* Mask of affinity bits */
 #define MEM_RowSet    0x0020   /* Value is a RowSet object */
 #define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
-#define MEM_Invalid   0x0080   /* Value is undefined */
-#define MEM_TypeMask  0x00ff   /* Mask of type bits */
+#define MEM_Undefined 0x0080   /* Value is undefined */
+#define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
+#define MEM_TypeMask  0x81ff   /* Mask of type bits */
+
 
 /* Whenever Mem contains a valid string or blob representation, one of
 ** the following flags must be set to determine the memory management
@@ -12785,16 +17870,23 @@ struct Mem {
 ** string is \000 or \u0000 terminated
 */
 #define MEM_Term      0x0200   /* String rep is nul terminated */
-#define MEM_Dyn       0x0400   /* Need to call sqliteFree() on Mem.z */
+#define MEM_Dyn       0x0400   /* Need to call Mem.xDel() on Mem.z */
 #define MEM_Static    0x0800   /* Mem.z points to a static string */
 #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
 #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
 #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
+#define MEM_Subtype   0x8000   /* Mem.eSubtype is valid */
 #ifdef SQLITE_OMIT_INCRBLOB
   #undef MEM_Zero
   #define MEM_Zero 0x0000
 #endif
 
+/* Return TRUE if Mem X contains dynamically allocated content - anything
+** that needs to be deallocated to avoid a leak.
+*/
+#define VdbeMemDynamic(X)  \
+  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))!=0)
+
 /*
 ** Clear any existing type flags from a Mem and replace them with f
 */
@@ -12806,30 +17898,26 @@ struct Mem {
 ** is for use inside assert() statements only.
 */
 #ifdef SQLITE_DEBUG
-#define memIsValid(M)  ((M)->flags & MEM_Invalid)==0
-#endif
-
-
-/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
-** additional information about auxiliary information bound to arguments
-** of the function.  This is used to implement the sqlite3_get_auxdata()
-** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
-** that can be associated with a constant argument to a function.  This
-** allows functions such as "regexp" to compile their constant regular
-** expression argument once and reused the compiled code for multiple
-** invocations.
-*/
-struct VdbeFunc {
-  FuncDef *pFunc;               /* The definition of the function */
-  int nAux;                     /* Number of entries allocated for apAux[] */
-  struct AuxData {
-    void *pAux;                   /* Aux data for the i-th argument */
-    void (*xDelete)(void *);      /* Destructor for the aux data */
-  } apAux[1];                   /* One slot for each function argument */
+#define memIsValid(M)  ((M)->flags & MEM_Undefined)==0
+#endif
+
+/*
+** Each auxiliary data pointer stored by a user defined function 
+** implementation calling sqlite3_set_auxdata() is stored in an instance
+** of this structure. All such structures associated with a single VM
+** are stored in a linked list headed at Vdbe.pAuxData. All are destroyed
+** when the VM is halted (if not before).
+*/
+struct AuxData {
+  int iOp;                        /* Instruction number of OP_Function opcode */
+  int iArg;                       /* Index of function argument. */
+  void *pAux;                     /* Aux data pointer */
+  void (*xDelete)(void *);        /* Destructor for the aux data */
+  AuxData *pNext;                 /* Next element in list */
 };
 
 /*
-** The "context" argument for a installable function.  A pointer to an
+** The "context" argument for an installable function.  A pointer to an
 ** instance of this structure is the first argument to the routines used
 ** implement the SQL functions.
 **
@@ -12842,12 +17930,43 @@ struct VdbeFunc {
 ** (Mem) which are only defined there.
 */
 struct sqlite3_context {
-  FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
-  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
-  Mem s;                /* The return value is stored here */
-  Mem *pMem;            /* Memory cell used to store aggregate context */
-  int isError;          /* Error code returned by the function. */
-  CollSeq *pColl;       /* Collating sequence */
+  Mem *pOut;              /* The return value is stored here */
+  FuncDef *pFunc;         /* Pointer to function information */
+  Mem *pMem;              /* Memory cell used to store aggregate context */
+  Vdbe *pVdbe;            /* The VM that owns this context */
+  int iOp;                /* Instruction number of OP_Function */
+  int isError;            /* Error code returned by the function. */
+  u8 skipFlag;            /* Skip accumulator loading if true */
+  u8 fErrorOrAux;         /* isError!=0 or pVdbe->pAuxData modified */
+  u8 argc;                /* Number of arguments */
+  sqlite3_value *argv[1]; /* Argument set */
+};
+
+/*
+** An Explain object accumulates indented output which is helpful
+** in describing recursive data structures.
+*/
+struct Explain {
+  Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
+  StrAccum str;      /* The string being accumulated */
+  int nIndent;       /* Number of elements in aIndent */
+  u16 aIndent[100];  /* Levels of indentation */
+  char zBase[100];   /* Initial space */
+};
+
+/* A bitfield type for use inside of structures.  Always follow with :N where
+** N is the number of bits.
+*/
+typedef unsigned bft;  /* Bit Field Type */
+
+typedef struct ScanStatus ScanStatus;
+struct ScanStatus {
+  int addrExplain;                /* OP_Explain for loop */
+  int addrLoop;                   /* Address of "loops" counter */
+  int addrVisit;                  /* Address of "rows visited" counter */
+  int iSelectID;                  /* The "Select-ID" for this loop */
+  LogEst nEst;                    /* Estimated output rows per loop */
+  char *zName;                    /* Name of table or index */
 };
 
 /*
@@ -12856,14 +17975,6 @@ struct sqlite3_context {
 **
 ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
 ** is really a pointer to an instance of this structure.
-**
-** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
-** any virtual table method invocations made by the vdbe program. It is
-** set to 2 for xDestroy method calls and 1 for all other methods. This
-** variable is used for two purposes: to allow xDestroy methods to execute
-** "DROP TABLE" statements and to prevent some nasty side effects of
-** malloc failure when SQLite is invoked recursively by a virtual table 
-** method function.
 */
 struct Vdbe {
   sqlite3 *db;            /* The database connection that owns this statement */
@@ -12872,14 +17983,10 @@ struct Vdbe {
   Mem **apArg;            /* Arguments to currently executing user function */
   Mem *aColName;          /* Column names to return */
   Mem *pResultSet;        /* Pointer to an array of results */
+  Parse *pParse;          /* Parsing context used to create this Vdbe */
   int nMem;               /* Number of memory locations currently allocated */
   int nOp;                /* Number of instructions in the program */
-  int nOpAlloc;           /* Number of slots allocated for aOp[] */
-  int nLabel;             /* Number of labels used */
-  int nLabelAlloc;        /* Number of slots allocated in aLabel[] */
-  int *aLabel;            /* Space to hold the labels */
-  u16 nResColumn;         /* Number of columns in one row of the result set */
-  u16 nCursor;            /* Number of slots in apCsr[] */
+  int nCursor;            /* Number of slots in apCsr[] */
   u32 magic;              /* Magic number for sanity checking */
   char *zErrMsg;          /* Error message written here */
   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
@@ -12891,36 +17998,48 @@ struct Vdbe {
   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
   int pc;                 /* The program counter */
   int rc;                 /* Value to return */
+#ifdef SQLITE_DEBUG
+  int rcApp;              /* errcode set by sqlite3_result_error_code() */
+#endif
+  u16 nResColumn;         /* Number of columns in one row of the result set */
   u8 errorAction;         /* Recovery action to do in case of an error */
-  u8 explain;             /* True if EXPLAIN present on SQL command */
-  u8 changeCntOn;         /* True to update the change-counter */
-  u8 expired;             /* True if the VM needs to be recompiled */
-  u8 runOnlyOnce;         /* Automatically expire on reset */
+  bft expired:1;          /* True if the VM needs to be recompiled */
+  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
-  u8 inVtabMethod;        /* See comments above */
-  u8 usesStmtJournal;     /* True if uses a statement journal */
-  u8 readOnly;            /* True for read-only statements */
-  u8 isPrepareV2;         /* True if prepared with prepare_v2() */
+  bft explain:2;          /* True if EXPLAIN present on SQL command */
+  bft changeCntOn:1;      /* True to update the change-counter */
+  bft runOnlyOnce:1;      /* Automatically expire on reset */
+  bft usesStmtJournal:1;  /* True if uses a statement journal */
+  bft readOnly:1;         /* True for statements that do not write */
+  bft bIsReader:1;        /* True for statements that read */
+  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
   int nChange;            /* Number of db changes made since last reset */
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
-  int aCounter[3];        /* Counters used by sqlite3_stmt_status() */
+  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
 #ifndef SQLITE_OMIT_TRACE
   i64 startTime;          /* Time when query started - used for profiling */
 #endif
+  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
+  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
   char *zSql;             /* Text of the SQL statement that generated this */
   void *pFree;            /* Free this when deleting the vdbe */
-#ifdef SQLITE_DEBUG
-  FILE *trace;            /* Write an execution trace here, if not NULL */
-#endif
   VdbeFrame *pFrame;      /* Parent frame */
   VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
   int nFrame;             /* Number of frames in pFrame list */
   u32 expmask;            /* Binding to these vars invalidates VM */
   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
+  int nOnceFlag;          /* Size of array aOnceFlag[] */
+  u8 *aOnceFlag;          /* Flags for OP_Once */
+  AuxData *pAuxData;      /* Linked list of auxdata allocations */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  i64 *anExec;            /* Number of times each op has been executed */
+  int nScan;              /* Entries in aScan[] */
+  ScanStatus *aScan;      /* Scan definitions for sqlite3_stmt_scanstatus() */
+#endif
 };
 
 /*
@@ -12932,24 +18051,45 @@ struct Vdbe {
 #define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
 
 /*
+** Structure used to store the context required by the 
+** sqlite3_preupdate_*() API functions.
+*/
+struct PreUpdate {
+  Vdbe *v;
+  VdbeCursor *pCsr;               /* Cursor to read old values from */
+  int op;                         /* One of SQLITE_INSERT, UPDATE, DELETE */
+  u8 *aRecord;                    /* old.* database record */
+  KeyInfo keyinfo;
+  UnpackedRecord *pUnpacked;      /* Unpacked version of aRecord[] */
+  UnpackedRecord *pNewUnpacked;   /* Unpacked version of new.* record */
+  int iNewReg;                    /* Register for new.* values */
+  i64 iKey1;                      /* First key value passed to hook */
+  i64 iKey2;                      /* Second key value passed to hook */
+  int iPKey;                      /* If not negative index of IPK column */
+  Mem *aNew;                      /* Array of new.* values */
+};
+
+/*
 ** Function prototypes
 */
+SQLITE_PRIVATE void sqlite3VdbeError(Vdbe*, const char *, ...);
 SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
 void sqliteVdbePopStack(Vdbe*,int);
-SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor*);
+SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor**, int*);
+SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor*);
 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
 SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, Op*);
 #endif
 SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32);
-SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int);
-SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
+SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8);
+SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int, u32*);
+SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);
 SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
-SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
+SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3*, AuxData**, int, int);
 
 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
-SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
-SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3*, BtCursor *, i64 *);
-SQLITE_PRIVATE int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
+SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*);
+SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3*, BtCursor*, i64*);
 SQLITE_PRIVATE int sqlite3VdbeExec(Vdbe*);
 SQLITE_PRIVATE int sqlite3VdbeList(Vdbe*);
 SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe*);
@@ -12966,60 +18106,57 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem*, i64);
 #else
 SQLITE_PRIVATE   void sqlite3VdbeMemSetDouble(Mem*, double);
 #endif
+SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem*,sqlite3*,u16);
 SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem*);
 SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem*,int);
 SQLITE_PRIVATE void sqlite3VdbeMemSetRowSet(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem*);
-SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem*, int);
+SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem*, u8, u8);
 SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemIntegerify(Mem*);
 SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);
 SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
 SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
-SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
+SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem*,u8,u8);
+SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,int,Mem*);
 SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
-SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p);
-#define MemReleaseExt(X)  \
-  if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \
-    sqlite3VdbeMemReleaseExternal(X);
 SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
 SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
 SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
+SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
 SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
 SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*);
 SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
-SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(Vdbe*,VdbeCursor*,int,const char*,Table*,i64,int);
+#endif
 SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p);
 
-#ifdef SQLITE_OMIT_MERGE_SORT
-# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
-# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
-# define sqlite3VdbeSorterClose(Y,Z)
-# define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
-# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
-# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
-# define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
-#else
-SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
+SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, int, VdbeCursor *);
+SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *, VdbeSorter *);
 SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
-SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *);
-SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);
-SQLITE_PRIVATE int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
-SQLITE_PRIVATE int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, Mem *);
-SQLITE_PRIVATE int sqlite3VdbeSorterCompare(VdbeCursor *, Mem *, int *);
+SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
+SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
+SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *, int *);
+SQLITE_PRIVATE int sqlite3VdbeSorterWrite(const VdbeCursor *, Mem *);
+SQLITE_PRIVATE int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int, int *);
+
+#if !defined(SQLITE_OMIT_SHARED_CACHE) 
+SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
+#else
+# define sqlite3VdbeEnter(X)
 #endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
-SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
 SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
 #else
-# define sqlite3VdbeEnter(X)
 # define sqlite3VdbeLeave(X)
 #endif
 
 #ifdef SQLITE_DEBUG
-SQLITE_PRIVATE void sqlite3VdbeMemPrepareToChange(Vdbe*,Mem*);
+SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);
+SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem*);
 #endif
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
@@ -13037,11 +18174,13 @@ SQLITE_PRIVATE int sqlite3VdbeMemHandleBom(Mem *pMem);
 
 #ifndef SQLITE_OMIT_INCRBLOB
 SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);
+  #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
 #else
   #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
+  #define ExpandBlob(P) SQLITE_OK
 #endif
 
-#endif /* !defined(_VDBEINT_H_) */
+#endif /* !defined(SQLITE_VDBEINT_H) */
 
 /************** End of vdbeInt.h *********************************************/
 /************** Continuing where we left off in status.c *********************/
@@ -13049,12 +18188,34 @@ SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);
 /*
 ** Variables in which to record status information.
 */
+#if SQLITE_PTRSIZE>4
+typedef sqlite3_int64 sqlite3StatValueType;
+#else
+typedef u32 sqlite3StatValueType;
+#endif
 typedef struct sqlite3StatType sqlite3StatType;
 static SQLITE_WSD struct sqlite3StatType {
-  int nowValue[10];         /* Current value */
-  int mxValue[10];          /* Maximum value */
+  sqlite3StatValueType nowValue[10];  /* Current value */
+  sqlite3StatValueType mxValue[10];   /* Maximum value */
 } sqlite3Stat = { {0,}, {0,} };
 
+/*
+** Elements of sqlite3Stat[] are protected by either the memory allocator
+** mutex, or by the pcache1 mutex.  The following array determines which.
+*/
+static const char statMutex[] = {
+  0,  /* SQLITE_STATUS_MEMORY_USED */
+  1,  /* SQLITE_STATUS_PAGECACHE_USED */
+  1,  /* SQLITE_STATUS_PAGECACHE_OVERFLOW */
+  0,  /* SQLITE_STATUS_SCRATCH_USED */
+  0,  /* SQLITE_STATUS_SCRATCH_OVERFLOW */
+  0,  /* SQLITE_STATUS_MALLOC_SIZE */
+  0,  /* SQLITE_STATUS_PARSER_STACK */
+  1,  /* SQLITE_STATUS_PAGECACHE_SIZE */
+  0,  /* SQLITE_STATUS_SCRATCH_SIZE */
+  0,  /* SQLITE_STATUS_MALLOC_COUNT */
+};
+
 
 /* The "wsdStat" macro will resolve to the status information
 ** state vector.  If writable static data is unsupported on the target,
@@ -13071,63 +18232,118 @@ static SQLITE_WSD struct sqlite3StatType {
 #endif
 
 /*
-** Return the current value of a status parameter.
+** Return the current value of a status parameter.  The caller must
+** be holding the appropriate mutex.
 */
-SQLITE_PRIVATE int sqlite3StatusValue(int op){
+SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int op){
   wsdStatInit;
   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
+  assert( op>=0 && op<ArraySize(statMutex) );
+  assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
+                                           : sqlite3MallocMutex()) );
   return wsdStat.nowValue[op];
 }
 
 /*
-** Add N to the value of a status record.  It is assumed that the
-** caller holds appropriate locks.
+** Add N to the value of a status record.  The caller must hold the
+** appropriate mutex.  (Locking is checked by assert()).
+**
+** The StatusUp() routine can accept positive or negative values for N.
+** The value of N is added to the current status value and the high-water
+** mark is adjusted if necessary.
+**
+** The StatusDown() routine lowers the current value by N.  The highwater
+** mark is unchanged.  N must be non-negative for StatusDown().
 */
-SQLITE_PRIVATE void sqlite3StatusAdd(int op, int N){
+SQLITE_PRIVATE void sqlite3StatusUp(int op, int N){
   wsdStatInit;
   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
+  assert( op>=0 && op<ArraySize(statMutex) );
+  assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
+                                           : sqlite3MallocMutex()) );
   wsdStat.nowValue[op] += N;
   if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
     wsdStat.mxValue[op] = wsdStat.nowValue[op];
   }
 }
+SQLITE_PRIVATE void sqlite3StatusDown(int op, int N){
+  wsdStatInit;
+  assert( N>=0 );
+  assert( op>=0 && op<ArraySize(statMutex) );
+  assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
+                                           : sqlite3MallocMutex()) );
+  assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
+  wsdStat.nowValue[op] -= N;
+}
 
 /*
-** Set the value of a status to X.
+** Adjust the highwater mark if necessary.
+** The caller must hold the appropriate mutex.
 */
-SQLITE_PRIVATE void sqlite3StatusSet(int op, int X){
+SQLITE_PRIVATE void sqlite3StatusHighwater(int op, int X){
+  sqlite3StatValueType newValue;
   wsdStatInit;
+  assert( X>=0 );
+  newValue = (sqlite3StatValueType)X;
   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
-  wsdStat.nowValue[op] = X;
-  if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
-    wsdStat.mxValue[op] = wsdStat.nowValue[op];
+  assert( op>=0 && op<ArraySize(statMutex) );
+  assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
+                                           : sqlite3MallocMutex()) );
+  assert( op==SQLITE_STATUS_MALLOC_SIZE
+          || op==SQLITE_STATUS_PAGECACHE_SIZE
+          || op==SQLITE_STATUS_SCRATCH_SIZE
+          || op==SQLITE_STATUS_PARSER_STACK );
+  if( newValue>wsdStat.mxValue[op] ){
+    wsdStat.mxValue[op] = newValue;
   }
 }
 
 /*
 ** Query status information.
-**
-** This implementation assumes that reading or writing an aligned
-** 32-bit integer is an atomic operation.  If that assumption is not true,
-** then this routine is not threadsafe.
 */
-SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
+SQLITE_API int SQLITE_STDCALL sqlite3_status64(
+  int op,
+  sqlite3_int64 *pCurrent,
+  sqlite3_int64 *pHighwater,
+  int resetFlag
+){
+  sqlite3_mutex *pMutex;
   wsdStatInit;
   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
     return SQLITE_MISUSE_BKPT;
   }
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
+  sqlite3_mutex_enter(pMutex);
   *pCurrent = wsdStat.nowValue[op];
   *pHighwater = wsdStat.mxValue[op];
   if( resetFlag ){
     wsdStat.mxValue[op] = wsdStat.nowValue[op];
   }
+  sqlite3_mutex_leave(pMutex);
+  (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */
   return SQLITE_OK;
 }
+SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
+  sqlite3_int64 iCur = 0, iHwtr = 0;
+  int rc;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
+  if( rc==0 ){
+    *pCurrent = (int)iCur;
+    *pHighwater = (int)iHwtr;
+  }
+  return rc;
+}
 
 /*
 ** Query status information for a single database connection
 */
-SQLITE_API int sqlite3_db_status(
+SQLITE_API int SQLITE_STDCALL sqlite3_db_status(
   sqlite3 *db,          /* The database connection whose status is desired */
   int op,               /* Status verb */
   int *pCurrent,        /* Write current value here */
@@ -13135,6 +18351,11 @@ SQLITE_API int sqlite3_db_status(
   int resetFlag         /* Reset high-water mark if true */
 ){
   int rc = SQLITE_OK;   /* Return code */
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   switch( op ){
     case SQLITE_DBSTATUS_LOOKASIDE_USED: {
@@ -13167,6 +18388,7 @@ SQLITE_API int sqlite3_db_status(
     ** by all pagers associated with the given database connection.  The
     ** highwater mark is meaningless and is returned as zero.
     */
+    case SQLITE_DBSTATUS_CACHE_USED_SHARED:
     case SQLITE_DBSTATUS_CACHE_USED: {
       int totalUsed = 0;
       int i;
@@ -13175,7 +18397,11 @@ SQLITE_API int sqlite3_db_status(
         Btree *pBt = db->aDb[i].pBt;
         if( pBt ){
           Pager *pPager = sqlite3BtreePager(pBt);
-          totalUsed += sqlite3PagerMemUsed(pPager);
+          int nByte = sqlite3PagerMemUsed(pPager);
+          if( op==SQLITE_DBSTATUS_CACHE_USED_SHARED ){
+            nByte = nByte / sqlite3BtreeConnectionCount(pBt);
+          }
+          totalUsed += nByte;
         }
       }
       sqlite3BtreeLeaveAll(db);
@@ -13206,10 +18432,10 @@ SQLITE_API int sqlite3_db_status(
             + pSchema->idxHash.count
             + pSchema->fkeyHash.count
           );
-          nByte += sqlite3MallocSize(pSchema->tblHash.ht);
-          nByte += sqlite3MallocSize(pSchema->trigHash.ht);
-          nByte += sqlite3MallocSize(pSchema->idxHash.ht);
-          nByte += sqlite3MallocSize(pSchema->fkeyHash.ht);
+          nByte += sqlite3_msize(pSchema->tblHash.ht);
+          nByte += sqlite3_msize(pSchema->trigHash.ht);
+          nByte += sqlite3_msize(pSchema->idxHash.ht);
+          nByte += sqlite3_msize(pSchema->fkeyHash.ht);
 
           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
@@ -13238,11 +18464,12 @@ SQLITE_API int sqlite3_db_status(
 
       db->pnBytesFreed = &nByte;
       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
-        sqlite3VdbeDeleteObject(db, pVdbe);
+        sqlite3VdbeClearObject(db, pVdbe);
+        sqlite3DbFree(db, pVdbe);
       }
       db->pnBytesFreed = 0;
 
-      *pHighwater = 0;
+      *pHighwater = 0;  /* IMP: R-64479-57858 */
       *pCurrent = nByte;
 
       break;
@@ -13254,10 +18481,12 @@ SQLITE_API int sqlite3_db_status(
     ** to zero.
     */
     case SQLITE_DBSTATUS_CACHE_HIT:
-    case SQLITE_DBSTATUS_CACHE_MISS: {
+    case SQLITE_DBSTATUS_CACHE_MISS:
+    case SQLITE_DBSTATUS_CACHE_WRITE:{
       int i;
       int nRet = 0;
       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
+      assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );
 
       for(i=0; i<db->nDb; i++){
         if( db->aDb[i].pBt ){
@@ -13265,11 +18494,23 @@ SQLITE_API int sqlite3_db_status(
           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
         }
       }
-      *pHighwater = 0;
+      *pHighwater = 0; /* IMP: R-42420-56072 */
+                       /* IMP: R-54100-20147 */
+                       /* IMP: R-29431-39229 */
       *pCurrent = nRet;
       break;
     }
 
+    /* Set *pCurrent to non-zero if there are unresolved deferred foreign
+    ** key constraints.  Set *pCurrent to zero if all foreign key constraints
+    ** have been satisfied.  The *pHighwater is always set to zero.
+    */
+    case SQLITE_DBSTATUS_DEFERRED_FKS: {
+      *pHighwater = 0;  /* IMP: R-11967-56545 */
+      *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
+      break;
+    }
+
     default: {
       rc = SQLITE_ERROR;
     }
@@ -13298,7 +18539,7 @@ SQLITE_API int sqlite3_db_status(
 ** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** SQLite processes all times and dates as Julian Day numbers.  The
+** SQLite processes all times and dates as julian day numbers.  The
 ** dates and times are stored as the number of days since noon
 ** in Greenwich on November 24, 4714 B.C. according to the Gregorian
 ** calendar system. 
@@ -13306,14 +18547,14 @@ SQLITE_API int sqlite3_db_status(
 ** 1970-01-01 00:00:00 is JD 2440587.5
 ** 2000-01-01 00:00:00 is JD 2451544.5
 **
-** This implemention requires years to be expressed as a 4-digit number
+** This implementation requires years to be expressed as a 4-digit number
 ** which means that only dates between 0000-01-01 and 9999-12-31 can
 ** be represented, even though julian day numbers allow a much wider
 ** range of dates.
 **
 ** The Gregorian calendar system is used for all dates and times,
 ** even those that predate the Gregorian calendar.  Historians usually
-** use the Julian calendar for dates prior to 1582-10-15 and for some
+** use the julian calendar for dates prior to 1582-10-15 and for some
 ** dates afterwards, depending on locale.  Beware of this difference.
 **
 ** The conversion algorithms are implemented based on descriptions
@@ -13325,12 +18566,22 @@ SQLITE_API int sqlite3_db_status(
 **      Willmann-Bell, Inc
 **      Richmond, Virginia (USA)
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 /* #include <assert.h> */
 #include <time.h>
 
 #ifndef SQLITE_OMIT_DATETIME_FUNCS
 
+/*
+** The MSVC CRT on Windows CE may not have a localtime() function.
+** So declare a substitute.  The substitute function itself is
+** defined in "os_win.c".
+*/
+#if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
+    (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
+struct tm *__cdecl localtime(const time_t *);
+#endif
 
 /*
 ** A structure for holding a single date and time.
@@ -13346,38 +18597,54 @@ struct DateTime {
   char validHMS;     /* True (1) if h,m,s are valid */
   char validJD;      /* True (1) if iJD is valid */
   char validTZ;      /* True (1) if tz is valid */
+  char tzSet;        /* Timezone was set explicitly */
 };
 
 
 /*
-** Convert zDate into one or more integers.  Additional arguments
-** come in groups of 5 as follows:
+** Convert zDate into one or more integers according to the conversion
+** specifier zFormat.
+**
+** zFormat[] contains 4 characters for each integer converted, except for
+** the last integer which is specified by three characters.  The meaning
+** of a four-character format specifiers ABCD is:
+**
+**    A:   number of digits to convert.  Always "2" or "4".
+**    B:   minimum value.  Always "0" or "1".
+**    C:   maximum value, decoded as:
+**           a:  12
+**           b:  14
+**           c:  24
+**           d:  31
+**           e:  59
+**           f:  9999
+**    D:   the separator character, or \000 to indicate this is the
+**         last number to convert.
 **
-**       N       number of digits in the integer
-**       min     minimum allowed value of the integer
-**       max     maximum allowed value of the integer
-**       nextC   first character after the integer
-**       pVal    where to write the integers value.
+** Example:  To translate an ISO-8601 date YYYY-MM-DD, the format would
+** be "40f-21a-20c".  The "40f-" indicates the 4-digit year followed by "-".
+** The "21a-" indicates the 2-digit month followed by "-".  The "20c" indicates
+** the 2-digit day which is the last integer in the set.
 **
-** Conversions continue until one with nextC==0 is encountered.
 ** The function returns the number of successful conversions.
 */
-static int getDigits(const char *zDate, ...){
+static int getDigits(const char *zDate, const char *zFormat, ...){
+  /* The aMx[] array translates the 3rd character of each format
+  ** spec into a max size:    a   b   c   d   e     f */
+  static const u16 aMx[] = { 12, 14, 24, 31, 59, 9999 };
   va_list ap;
-  int val;
-  int N;
-  int min;
-  int max;
-  int nextC;
-  int *pVal;
   int cnt = 0;
-  va_start(ap, zDate);
+  char nextC;
+  va_start(ap, zFormat);
   do{
-    N = va_arg(ap, int);
-    min = va_arg(ap, int);
-    max = va_arg(ap, int);
-    nextC = va_arg(ap, int);
-    pVal = va_arg(ap, int*);
+    char N = zFormat[0] - '0';
+    char min = zFormat[1] - '0';
+    int val = 0;
+    u16 max;
+
+    assert( zFormat[2]>='a' && zFormat[2]<='f' );
+    max = aMx[zFormat[2] - 'a'];
+    nextC = zFormat[3];
     val = 0;
     while( N-- ){
       if( !sqlite3Isdigit(*zDate) ){
@@ -13386,12 +18653,13 @@ static int getDigits(const char *zDate, ...){
       val = val*10 + *zDate - '0';
       zDate++;
     }
-    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
+    if( val<(int)min || val>(int)max || (nextC!=0 && nextC!=*zDate) ){
       goto end_getDigits;
     }
-    *pVal = val;
+    *va_arg(ap,int*) = val;
     zDate++;
     cnt++;
+    zFormat += 4;
   }while( nextC );
 end_getDigits:
   va_end(ap);
@@ -13432,13 +18700,14 @@ static int parseTimezone(const char *zDate, DateTime *p){
     return c!=0;
   }
   zDate++;
-  if( getDigits(zDate, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){
+  if( getDigits(zDate, "20b:20e", &nHr, &nMn)!=2 ){
     return 1;
   }
   zDate += 5;
   p->tz = sgn*(nMn + nHr*60);
 zulu_time:
   while( sqlite3Isspace(*zDate) ){ zDate++; }
+  p->tzSet = 1;
   return *zDate!=0;
 }
 
@@ -13452,13 +18721,13 @@ zulu_time:
 static int parseHhMmSs(const char *zDate, DateTime *p){
   int h, m, s;
   double ms = 0.0;
-  if( getDigits(zDate, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){
+  if( getDigits(zDate, "20c:20e", &h, &m)!=2 ){
     return 1;
   }
   zDate += 5;
   if( *zDate==':' ){
     zDate++;
-    if( getDigits(zDate, 2, 0, 59, 0, &s)!=1 ){
+    if( getDigits(zDate, "20e", &s)!=1 ){
       return 1;
     }
     zDate += 2;
@@ -13546,7 +18815,7 @@ static int parseYyyyMmDd(const char *zDate, DateTime *p){
   }else{
     neg = 0;
   }
-  if( getDigits(zDate,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&D)!=3 ){
+  if( getDigits(zDate, "40f-21a-21d", &Y, &M, &D)!=3 ){
     return 1;
   }
   zDate += 10;
@@ -13575,8 +18844,8 @@ static int parseYyyyMmDd(const char *zDate, DateTime *p){
 ** Return the number of errors.
 */
 static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
-  sqlite3 *db = sqlite3_context_db_handle(context);
-  if( sqlite3OsCurrentTimeInt64(db->pVfs, &p->iJD)==SQLITE_OK ){
+  p->iJD = sqlite3StmtCurrentTime(context);
+  if( p->iJD>0 ){
     p->validJD = 1;
     return 0;
   }else{
@@ -13585,7 +18854,7 @@ static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
 }
 
 /*
-** Attempt to parse the given string into a Julian Day Number.  Return
+** Attempt to parse the given string into a julian day number.  Return
 ** the number of errors.
 **
 ** The following are acceptable forms for the input string:
@@ -13636,7 +18905,7 @@ static void computeYMD(DateTime *p){
     A = Z + 1 + A - (A/4);
     B = A + 1524;
     C = (int)((B - 122.1)/365.25);
-    D = (36525*C)/100;
+    D = (36525*(C&32767))/100;
     E = (int)((B-D)/30.6001);
     X1 = (int)(30.6001*E);
     p->D = B - D - X1;
@@ -13681,6 +18950,7 @@ static void clearYMD_HMS_TZ(DateTime *p){
   p->validTZ = 0;
 }
 
+#ifndef SQLITE_OMIT_LOCALTIME
 /*
 ** On recent Windows platforms, the localtime_s() function is available
 ** as part of the "Secure CRT". It is essentially equivalent to 
@@ -13693,12 +18963,12 @@ static void clearYMD_HMS_TZ(DateTime *p){
 ** already, check for an MSVC build environment that provides 
 ** localtime_s().
 */
-#if !defined(HAVE_LOCALTIME_R) && !defined(HAVE_LOCALTIME_S) && \
-     defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE)
+#if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S \
+    && defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE)
+#undef  HAVE_LOCALTIME_S
 #define HAVE_LOCALTIME_S 1
 #endif
 
-#ifndef SQLITE_OMIT_LOCALTIME
 /*
 ** The following routine implements the rough equivalent of localtime_r()
 ** using whatever operating-system specific localtime facility that
@@ -13707,11 +18977,14 @@ static void clearYMD_HMS_TZ(DateTime *p){
 **
 ** If the sqlite3GlobalConfig.bLocaltimeFault variable is true then this
 ** routine will always fail.
+**
+** EVIDENCE-OF: R-62172-00036 In this implementation, the standard C
+** library function localtime_r() is used to assist in the calculation of
+** local time.
 */
 static int osLocaltime(time_t *t, struct tm *pTm){
   int rc;
-#if (!defined(HAVE_LOCALTIME_R) || !HAVE_LOCALTIME_R) \
-      && (!defined(HAVE_LOCALTIME_S) || !HAVE_LOCALTIME_S)
+#if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S
   struct tm *pX;
 #if SQLITE_THREADSAFE>0
   sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
@@ -13728,7 +19001,7 @@ static int osLocaltime(time_t *t, struct tm *pTm){
 #ifndef SQLITE_OMIT_BUILTIN_TEST
   if( sqlite3GlobalConfig.bLocaltimeFault ) return 1;
 #endif
-#if defined(HAVE_LOCALTIME_R) && HAVE_LOCALTIME_R
+#if HAVE_LOCALTIME_R
   rc = localtime_r(t, pTm)==0;
 #else
   rc = localtime_s(pTm, t);
@@ -13763,6 +19036,11 @@ static sqlite3_int64 localtimeOffset(
   x = *p;
   computeYMD_HMS(&x);
   if( x.Y<1971 || x.Y>=2038 ){
+    /* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only
+    ** works for years between 1970 and 2037. For dates outside this range,
+    ** SQLite attempts to map the year into an equivalent year within this
+    ** range, do the calculation, then map the year back.
+    */
     x.Y = 2000;
     x.M = 1;
     x.D = 1;
@@ -13862,13 +19140,18 @@ static int parseModifier(sqlite3_context *pCtx, const char *zMod, DateTime *p){
       }
 #ifndef SQLITE_OMIT_LOCALTIME
       else if( strcmp(z, "utc")==0 ){
-        sqlite3_int64 c1;
-        computeJD(p);
-        c1 = localtimeOffset(p, pCtx, &rc);
-        if( rc==SQLITE_OK ){
-          p->iJD -= c1;
-          clearYMD_HMS_TZ(p);
-          p->iJD += c1 - localtimeOffset(p, pCtx, &rc);
+        if( p->tzSet==0 ){
+          sqlite3_int64 c1;
+          computeJD(p);
+          c1 = localtimeOffset(p, pCtx, &rc);
+          if( rc==SQLITE_OK ){
+            p->iJD -= c1;
+            clearYMD_HMS_TZ(p);
+            p->iJD += c1 - localtimeOffset(p, pCtx, &rc);
+          }
+          p->tzSet = 1;
+        }else{
+          rc = SQLITE_OK;
         }
       }
 #endif
@@ -14147,7 +19430,7 @@ static void dateFunc(
 **   %f  ** fractional seconds  SS.SSS
 **   %H  hour 00-24
 **   %j  day of year 000-366
-**   %J  ** Julian day number
+**   %J  ** julian day number
 **   %m  month 01-12
 **   %M  minute 00-59
 **   %s  seconds since 1970-01-01
@@ -14167,8 +19450,10 @@ static void strftimeFunc(
   size_t i,j;
   char *z;
   sqlite3 *db;
-  const char *zFmt = (const char*)sqlite3_value_text(argv[0]);
+  const char *zFmt;
   char zBuf[100];
+  if( argc==0 ) return;
+  zFmt = (const char*)sqlite3_value_text(argv[0]);
   if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;
   db = sqlite3_context_db_handle(context);
   for(i=0, n=1; zFmt[i]; i++, n++){
@@ -14214,7 +19499,7 @@ static void strftimeFunc(
     sqlite3_result_error_toobig(context);
     return;
   }else{
-    z = sqlite3DbMallocRaw(db, (int)n);
+    z = sqlite3DbMallocRawNN(db, (int)n);
     if( z==0 ){
       sqlite3_result_error_nomem(context);
       return;
@@ -14350,7 +19635,6 @@ static void currentTimeFunc(
 ){
   time_t t;
   char *zFormat = (char *)sqlite3_user_data(context);
-  sqlite3 *db;
   sqlite3_int64 iT;
   struct tm *pTm;
   struct tm sNow;
@@ -14359,10 +19643,10 @@ static void currentTimeFunc(
   UNUSED_PARAMETER(argc);
   UNUSED_PARAMETER(argv);
 
-  db = sqlite3_context_db_handle(context);
-  if( sqlite3OsCurrentTimeInt64(db->pVfs, &iT) ) return;
+  iT = sqlite3StmtCurrentTime(context);
+  if( iT<=0 ) return;
   t = iT/1000 - 10000*(sqlite3_int64)21086676;
-#ifdef HAVE_GMTIME_R
+#if HAVE_GMTIME_R
   pTm = gmtime_r(&t, &sNow);
 #else
   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
@@ -14383,29 +19667,23 @@ static void currentTimeFunc(
 ** external linkage.
 */
 SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void){
-  static SQLITE_WSD FuncDef aDateTimeFuncs[] = {
+  static FuncDef aDateTimeFuncs[] = {
 #ifndef SQLITE_OMIT_DATETIME_FUNCS
-    FUNCTION(julianday,        -1, 0, 0, juliandayFunc ),
-    FUNCTION(date,             -1, 0, 0, dateFunc      ),
-    FUNCTION(time,             -1, 0, 0, timeFunc      ),
-    FUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
-    FUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
-    FUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
-    FUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
-    FUNCTION(current_date,      0, 0, 0, cdateFunc     ),
+    DFUNCTION(julianday,        -1, 0, 0, juliandayFunc ),
+    DFUNCTION(date,             -1, 0, 0, dateFunc      ),
+    DFUNCTION(time,             -1, 0, 0, timeFunc      ),
+    DFUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
+    DFUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
+    DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
+    DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
+    DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),
 #else
     STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),
     STR_FUNCTION(current_date,      0, "%Y-%m-%d",          0, currentTimeFunc),
     STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
 #endif
   };
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aDateTimeFuncs);
-
-  for(i=0; i<ArraySize(aDateTimeFuncs); i++){
-    sqlite3FuncDefInsert(pHash, &aFunc[i]);
-  }
+  sqlite3InsertBuiltinFuncs(aDateTimeFuncs, ArraySize(aDateTimeFuncs));
 }
 
 /************** End of date.c ************************************************/
@@ -14425,8 +19703,29 @@ SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void){
 ** This file contains OS interface code that is common to all
 ** architectures.
 */
-#define _SQLITE_OS_C_ 1
-#undef _SQLITE_OS_C_
+/* #include "sqliteInt.h" */
+
+/*
+** If we compile with the SQLITE_TEST macro set, then the following block
+** of code will give us the ability to simulate a disk I/O error.  This
+** is used for testing the I/O recovery logic.
+*/
+#if defined(SQLITE_TEST)
+SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
+SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
+SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
+SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
+SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
+SQLITE_API int sqlite3_diskfull_pending = 0;
+SQLITE_API int sqlite3_diskfull = 0;
+#endif /* defined(SQLITE_TEST) */
+
+/*
+** When testing, also keep a count of the number of open files.
+*/
+#if defined(SQLITE_TEST)
+SQLITE_API int sqlite3_open_file_count = 0;
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** The default SQLite sqlite3_vfs implementations do not allocate
@@ -14435,22 +19734,29 @@ SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void){
 ** So we test the effects of a malloc() failing and the sqlite3OsXXX()
 ** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.
 **
-** The following functions are instrumented for malloc() failure 
+** The following functions are instrumented for malloc() failure
 ** testing:
 **
-**     sqlite3OsOpen()
 **     sqlite3OsRead()
 **     sqlite3OsWrite()
 **     sqlite3OsSync()
+**     sqlite3OsFileSize()
 **     sqlite3OsLock()
+**     sqlite3OsCheckReservedLock()
+**     sqlite3OsFileControl()
+**     sqlite3OsShmMap()
+**     sqlite3OsOpen()
+**     sqlite3OsDelete()
+**     sqlite3OsAccess()
+**     sqlite3OsFullPathname()
 **
 */
 #if defined(SQLITE_TEST)
 SQLITE_API int sqlite3_memdebug_vfs_oom_test = 1;
   #define DO_OS_MALLOC_TEST(x)                                       \
-  if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3IsMemJournal(x))) {  \
+  if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3JournalIsInMemory(x))) { \
     void *pTstAlloc = sqlite3Malloc(10);                             \
-    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;                       \
+    if (!pTstAlloc) return SQLITE_IOERR_NOMEM_BKPT;                  \
     sqlite3_free(pTstAlloc);                                         \
   }
 #else
@@ -14463,13 +19769,11 @@ SQLITE_API int sqlite3_memdebug_vfs_oom_test = 1;
 ** of this would be completely automatic if SQLite were coded using
 ** C++ instead of plain old C.
 */
-SQLITE_PRIVATE int sqlite3OsClose(sqlite3_file *pId){
-  int rc = SQLITE_OK;
+SQLITE_PRIVATE void sqlite3OsClose(sqlite3_file *pId){
   if( pId->pMethods ){
-    rc = pId->pMethods->xClose(pId);
+    pId->pMethods->xClose(pId);
     pId->pMethods = 0;
   }
-  return rc;
 }
 SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
   DO_OS_MALLOC_TEST(id);
@@ -14501,9 +19805,37 @@ SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){
   DO_OS_MALLOC_TEST(id);
   return id->pMethods->xCheckReservedLock(id, pResOut);
 }
+
+/*
+** Use sqlite3OsFileControl() when we are doing something that might fail
+** and we need to know about the failures.  Use sqlite3OsFileControlHint()
+** when simply tossing information over the wall to the VFS and we do not
+** really care if the VFS receives and understands the information since it
+** is only a hint and can be safely ignored.  The sqlite3OsFileControlHint()
+** routine has no return value since the return value would be meaningless.
+*/
 SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
+#ifdef SQLITE_TEST
+  if( op!=SQLITE_FCNTL_COMMIT_PHASETWO ){
+    /* Faults are not injected into COMMIT_PHASETWO because, assuming SQLite
+    ** is using a regular VFS, it is called after the corresponding
+    ** transaction has been committed. Injecting a fault at this point
+    ** confuses the test scripts - the COMMIT comand returns SQLITE_NOMEM
+    ** but the transaction is committed anyway.
+    **
+    ** The core must call OsFileControl() though, not OsFileControlHint(),
+    ** as if a custom VFS (e.g. zipvfs) returns an error here, it probably
+    ** means the commit really has failed and an error should be returned
+    ** to the user.  */
+    DO_OS_MALLOC_TEST(id);
+  }
+#endif
   return id->pMethods->xFileControl(id, op, pArg);
 }
+SQLITE_PRIVATE void sqlite3OsFileControlHint(sqlite3_file *id, int op, void *pArg){
+  (void)id->pMethods->xFileControl(id, op, pArg);
+}
+
 SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id){
   int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;
   return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);
@@ -14527,23 +19859,44 @@ SQLITE_PRIVATE int sqlite3OsShmMap(
   int bExtend,                    /* True to extend file if necessary */
   void volatile **pp              /* OUT: Pointer to mapping */
 ){
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* The real implementation of xFetch and xUnfetch */
+SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  DO_OS_MALLOC_TEST(id);
+  return id->pMethods->xFetch(id, iOff, iAmt, pp);
+}
+SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return id->pMethods->xUnfetch(id, iOff, p);
+}
+#else
+/* No-op stubs to use when memory-mapped I/O is disabled */
+SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  *pp = 0;
+  return SQLITE_OK;
+}
+SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return SQLITE_OK;
+}
+#endif
+
 /*
 ** The next group of routines are convenience wrappers around the
 ** VFS methods.
 */
 SQLITE_PRIVATE int sqlite3OsOpen(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  sqlite3_file *pFile, 
-  int flags, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  sqlite3_file *pFile,
+  int flags,
   int *pFlagsOut
 ){
   int rc;
   DO_OS_MALLOC_TEST(0);
-  /* 0x87f3f is a mask of SQLITE_OPEN_ flags that are valid to be passed
+  /* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed
   ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,
   ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
   ** reaching the VFS. */
@@ -14552,23 +19905,26 @@ SQLITE_PRIVATE int sqlite3OsOpen(
   return rc;
 }
 SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  DO_OS_MALLOC_TEST(0);
+  assert( dirSync==0 || dirSync==1 );
   return pVfs->xDelete(pVfs, zPath, dirSync);
 }
 SQLITE_PRIVATE int sqlite3OsAccess(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int flags, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  int flags,
   int *pResOut
 ){
   DO_OS_MALLOC_TEST(0);
   return pVfs->xAccess(pVfs, zPath, flags, pResOut);
 }
 SQLITE_PRIVATE int sqlite3OsFullPathname(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int nPathOut, 
+  sqlite3_vfs *pVfs,
+  const char *zPath,
+  int nPathOut,
   char *zPathOut
 ){
+  DO_OS_MALLOC_TEST(0);
   zPathOut[0] = 0;
   return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
 }
@@ -14592,6 +19948,9 @@ SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufO
 SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
   return pVfs->xSleep(pVfs, nMicro);
 }
+SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs *pVfs){
+  return pVfs->xGetLastError ? pVfs->xGetLastError(pVfs, 0, 0) : 0;
+}
 SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
   int rc;
   /* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64()
@@ -14611,13 +19970,13 @@ SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p
 }
 
 SQLITE_PRIVATE int sqlite3OsOpenMalloc(
-  sqlite3_vfs *pVfs, 
-  const char *zFile, 
-  sqlite3_file **ppFile, 
+  sqlite3_vfs *pVfs,
+  const char *zFile,
+  sqlite3_file **ppFile,
   int flags,
   int *pOutFlags
 ){
-  int rc = SQLITE_NOMEM;
+  int rc;
   sqlite3_file *pFile;
   pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);
   if( pFile ){
@@ -14627,15 +19986,15 @@ SQLITE_PRIVATE int sqlite3OsOpenMalloc(
     }else{
       *ppFile = pFile;
     }
+  }else{
+    rc = SQLITE_NOMEM_BKPT;
   }
   return rc;
 }
-SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *pFile){
-  int rc = SQLITE_OK;
+SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *pFile){
   assert( pFile );
-  rc = sqlite3OsClose(pFile);
+  sqlite3OsClose(pFile);
   sqlite3_free(pFile);
-  return rc;
 }
 
 /*
@@ -14646,7 +20005,7 @@ SQLITE_PRIVATE int sqlite3OsCloseFree(sqlite3_file *pFile){
 */
 SQLITE_PRIVATE int sqlite3OsInit(void){
   void *p = sqlite3_malloc(10);
-  if( p==0 ) return SQLITE_NOMEM;
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   sqlite3_free(p);
   return sqlite3_os_init();
 }
@@ -14661,7 +20020,7 @@ static sqlite3_vfs * SQLITE_WSD vfsList = 0;
 ** Locate a VFS by name.  If no name is given, simply return the
 ** first VFS on the list.
 */
-SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
+SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfs){
   sqlite3_vfs *pVfs = 0;
 #if SQLITE_THREADSAFE
   sqlite3_mutex *mutex;
@@ -14707,12 +20066,16 @@ static void vfsUnlink(sqlite3_vfs *pVfs){
 ** VFS multiple times.  The new VFS becomes the default if makeDflt is
 ** true.
 */
-SQLITE_API int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
+SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
   MUTEX_LOGIC(sqlite3_mutex *mutex;)
 #ifndef SQLITE_OMIT_AUTOINIT
   int rc = sqlite3_initialize();
   if( rc ) return rc;
 #endif
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( pVfs==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+
   MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
   sqlite3_mutex_enter(mutex);
   vfsUnlink(pVfs);
@@ -14731,7 +20094,7 @@ SQLITE_API int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
 /*
 ** Unregister a VFS so that it is no longer accessible.
 */
-SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
+SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
 #if SQLITE_THREADSAFE
   sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
 #endif
@@ -14769,6 +20132,7 @@ SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
 ** during a hash table resize is a benign fault.
 */
 
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_BUILTIN_TEST
 
@@ -14850,6 +20214,7 @@ SQLITE_PRIVATE void sqlite3EndBenignMalloc(void){
 ** are merely placeholders.  Real drivers must be substituted using
 ** sqlite3_config() before SQLite will operate.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is the default.  It is
@@ -14910,8 +20275,33 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 ** to obtain the memory it needs.
 **
 ** This file contains implementations of the low-level memory allocation
-** routines specified in the sqlite3_mem_methods object.
+** routines specified in the sqlite3_mem_methods object.  The content of
+** this file is only used if SQLITE_SYSTEM_MALLOC is defined.  The
+** SQLITE_SYSTEM_MALLOC macro is defined automatically if neither the
+** SQLITE_MEMDEBUG nor the SQLITE_WIN32_MALLOC macros are defined.  The
+** default configuration is to use memory allocation routines in this
+** file.
+**
+** C-preprocessor macro summary:
+**
+**    HAVE_MALLOC_USABLE_SIZE     The configure script sets this symbol if
+**                                the malloc_usable_size() interface exists
+**                                on the target platform.  Or, this symbol
+**                                can be set manually, if desired.
+**                                If an equivalent interface exists by
+**                                a different name, using a separate -D
+**                                option to rename it.
+**
+**    SQLITE_WITHOUT_ZONEMALLOC   Some older macs lack support for the zone
+**                                memory allocator.  Set this symbol to enable
+**                                building on older macs.
+**
+**    SQLITE_WITHOUT_MSIZE        Set this symbol to disable the use of
+**                                _msize() on windows systems.  This might
+**                                be necessary when compiling for Delphi,
+**                                for example.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is the default.  It is
@@ -14919,6 +20309,71 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 ** macros.
 */
 #ifdef SQLITE_SYSTEM_MALLOC
+#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)
+
+/*
+** Use the zone allocator available on apple products unless the
+** SQLITE_WITHOUT_ZONEMALLOC symbol is defined.
+*/
+#include <sys/sysctl.h>
+#include <malloc/malloc.h>
+#include <libkern/OSAtomic.h>
+static malloc_zone_t* _sqliteZone_;
+#define SQLITE_MALLOC(x) malloc_zone_malloc(_sqliteZone_, (x))
+#define SQLITE_FREE(x) malloc_zone_free(_sqliteZone_, (x));
+#define SQLITE_REALLOC(x,y) malloc_zone_realloc(_sqliteZone_, (x), (y))
+#define SQLITE_MALLOCSIZE(x) \
+        (_sqliteZone_ ? _sqliteZone_->size(_sqliteZone_,x) : malloc_size(x))
+
+#else /* if not __APPLE__ */
+
+/*
+** Use standard C library malloc and free on non-Apple systems.  
+** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined.
+*/
+#define SQLITE_MALLOC(x)             malloc(x)
+#define SQLITE_FREE(x)               free(x)
+#define SQLITE_REALLOC(x,y)          realloc((x),(y))
+
+/*
+** The malloc.h header file is needed for malloc_usable_size() function
+** on some systems (e.g. Linux).
+*/
+#if HAVE_MALLOC_H && HAVE_MALLOC_USABLE_SIZE
+#  define SQLITE_USE_MALLOC_H 1
+#  define SQLITE_USE_MALLOC_USABLE_SIZE 1
+/*
+** The MSVCRT has malloc_usable_size(), but it is called _msize().  The
+** use of _msize() is automatic, but can be disabled by compiling with
+** -DSQLITE_WITHOUT_MSIZE.  Using the _msize() function also requires
+** the malloc.h header file.
+*/
+#elif defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE)
+#  define SQLITE_USE_MALLOC_H
+#  define SQLITE_USE_MSIZE
+#endif
+
+/*
+** Include the malloc.h header file, if necessary.  Also set define macro
+** SQLITE_MALLOCSIZE to the appropriate function name, which is _msize()
+** for MSVC and malloc_usable_size() for most other systems (e.g. Linux).
+** The memory size function can always be overridden manually by defining
+** the macro SQLITE_MALLOCSIZE to the desired function name.
+*/
+#if defined(SQLITE_USE_MALLOC_H)
+#  include <malloc.h>
+#  if defined(SQLITE_USE_MALLOC_USABLE_SIZE)
+#    if !defined(SQLITE_MALLOCSIZE)
+#      define SQLITE_MALLOCSIZE(x)   malloc_usable_size(x)
+#    endif
+#  elif defined(SQLITE_USE_MSIZE)
+#    if !defined(SQLITE_MALLOCSIZE)
+#      define SQLITE_MALLOCSIZE      _msize
+#    endif
+#  endif
+#endif /* defined(SQLITE_USE_MALLOC_H) */
+
+#endif /* __APPLE__ or not __APPLE__ */
 
 /*
 ** Like malloc(), but remember the size of the allocation
@@ -14929,10 +20384,18 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 ** routines.
 */
 static void *sqlite3MemMalloc(int nByte){
+#ifdef SQLITE_MALLOCSIZE
+  void *p = SQLITE_MALLOC( nByte );
+  if( p==0 ){
+    testcase( sqlite3GlobalConfig.xLog!=0 );
+    sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte);
+  }
+  return p;
+#else
   sqlite3_int64 *p;
   assert( nByte>0 );
   nByte = ROUND8(nByte);
-  p = malloc( nByte+8 );
+  p = SQLITE_MALLOC( nByte+8 );
   if( p ){
     p[0] = nByte;
     p++;
@@ -14941,6 +20404,7 @@ static void *sqlite3MemMalloc(int nByte){
     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte);
   }
   return (void *)p;
+#endif
 }
 
 /*
@@ -14952,10 +20416,14 @@ static void *sqlite3MemMalloc(int nByte){
 ** by higher-level routines.
 */
 static void sqlite3MemFree(void *pPrior){
+#ifdef SQLITE_MALLOCSIZE
+  SQLITE_FREE(pPrior);
+#else
   sqlite3_int64 *p = (sqlite3_int64*)pPrior;
   assert( pPrior!=0 );
   p--;
-  free(p);
+  SQLITE_FREE(p);
+#endif
 }
 
 /*
@@ -14963,11 +20431,16 @@ static void sqlite3MemFree(void *pPrior){
 ** or xRealloc().
 */
 static int sqlite3MemSize(void *pPrior){
+#ifdef SQLITE_MALLOCSIZE
+  assert( pPrior!=0 );
+  return (int)SQLITE_MALLOCSIZE(pPrior);
+#else
   sqlite3_int64 *p;
-  if( pPrior==0 ) return 0;
+  assert( pPrior!=0 );
   p = (sqlite3_int64*)pPrior;
   p--;
   return (int)p[0];
+#endif
 }
 
 /*
@@ -14976,16 +20449,26 @@ static int sqlite3MemSize(void *pPrior){
 **
 ** For this low-level interface, we know that pPrior!=0.  Cases where
 ** pPrior==0 while have been intercepted by higher-level routine and
-** redirected to xMalloc.  Similarly, we know that nByte>0 becauses
+** redirected to xMalloc.  Similarly, we know that nByte>0 because
 ** cases where nByte<=0 will have been intercepted by higher-level
 ** routines and redirected to xFree.
 */
 static void *sqlite3MemRealloc(void *pPrior, int nByte){
+#ifdef SQLITE_MALLOCSIZE
+  void *p = SQLITE_REALLOC(pPrior, nByte);
+  if( p==0 ){
+    testcase( sqlite3GlobalConfig.xLog!=0 );
+    sqlite3_log(SQLITE_NOMEM,
+      "failed memory resize %u to %u bytes",
+      SQLITE_MALLOCSIZE(pPrior), nByte);
+  }
+  return p;
+#else
   sqlite3_int64 *p = (sqlite3_int64*)pPrior;
   assert( pPrior!=0 && nByte>0 );
   assert( nByte==ROUND8(nByte) ); /* EV: R-46199-30249 */
   p--;
-  p = realloc(p, nByte+8 );
+  p = SQLITE_REALLOC(p, nByte+8 );
   if( p ){
     p[0] = nByte;
     p++;
@@ -14996,6 +20479,7 @@ static void *sqlite3MemRealloc(void *pPrior, int nByte){
       sqlite3MemSize(pPrior), nByte);
   }
   return (void*)p;
+#endif
 }
 
 /*
@@ -15009,6 +20493,34 @@ static int sqlite3MemRoundup(int n){
 ** Initialize this module.
 */
 static int sqlite3MemInit(void *NotUsed){
+#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)
+  int cpuCount;
+  size_t len;
+  if( _sqliteZone_ ){
+    return SQLITE_OK;
+  }
+  len = sizeof(cpuCount);
+  /* One usually wants to use hw.acctivecpu for MT decisions, but not here */
+  sysctlbyname("hw.ncpu", &cpuCount, &len, NULL, 0);
+  if( cpuCount>1 ){
+    /* defer MT decisions to system malloc */
+    _sqliteZone_ = malloc_default_zone();
+  }else{
+    /* only 1 core, use our own zone to contention over global locks, 
+    ** e.g. we have our own dedicated locks */
+    bool success;
+    malloc_zone_t* newzone = malloc_create_zone(4096, 0);
+    malloc_set_zone_name(newzone, "Sqlite_Heap");
+    do{
+      success = OSAtomicCompareAndSwapPtrBarrier(NULL, newzone, 
+                                 (void * volatile *)&_sqliteZone_);
+    }while(!_sqliteZone_);
+    if( !success ){
+      /* somebody registered a zone first */
+      malloc_destroy_zone(newzone);
+    }
+  }
+#endif
   UNUSED_PARAMETER(NotUsed);
   return SQLITE_OK;
 }
@@ -15066,6 +20578,7 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 ** This file contains implementations of the low-level memory allocation
 ** routines specified in the sqlite3_mem_methods object.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is used only if the
@@ -15225,7 +20738,7 @@ static int sqlite3MemSize(void *p){
     return 0;
   }
   pHdr = sqlite3MemsysGetHeader(p);
-  return pHdr->iSize;
+  return (int)pHdr->iSize;
 }
 
 /*
@@ -15267,7 +20780,7 @@ static void randomFill(char *pBuf, int nByte){
   x = SQLITE_PTR_TO_INT(pBuf);
   y = nByte | 1;
   while( nByte >= 4 ){
-    x = (x>>1) ^ (-(x&1) & 0xd0000001);
+    x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);
     y = y*1103515245 + 12345;
     r = x ^ y;
     *(int*)pBuf = r;
@@ -15275,7 +20788,7 @@ static void randomFill(char *pBuf, int nByte){
     nByte -= 4;
   }
   while( nByte-- > 0 ){
-    x = (x>>1) ^ (-(x&1) & 0xd0000001);
+    x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);
     y = y*1103515245 + 12345;
     r = x ^ y;
     *(pBuf++) = r & 0xff;
@@ -15370,9 +20883,9 @@ static void sqlite3MemFree(void *pPrior){
   }
   z = (char*)pBt;
   z -= pHdr->nTitle;
-  adjustStats(pHdr->iSize, -1);
+  adjustStats((int)pHdr->iSize, -1);
   randomFill(z, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +
-                pHdr->iSize + sizeof(int) + pHdr->nTitle);
+                (int)pHdr->iSize + sizeof(int) + pHdr->nTitle);
   free(z);
   sqlite3_mutex_leave(mem.mutex);  
 }
@@ -15394,9 +20907,9 @@ static void *sqlite3MemRealloc(void *pPrior, int nByte){
   pOldHdr = sqlite3MemsysGetHeader(pPrior);
   pNew = sqlite3MemMalloc(nByte);
   if( pNew ){
-    memcpy(pNew, pPrior, nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize);
+    memcpy(pNew, pPrior, (int)(nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize));
     if( nByte>pOldHdr->iSize ){
-      randomFill(&((char*)pNew)[pOldHdr->iSize], nByte - pOldHdr->iSize);
+      randomFill(&((char*)pNew)[pOldHdr->iSize], nByte - (int)pOldHdr->iSize);
     }
     sqlite3MemFree(pPrior);
   }
@@ -15440,7 +20953,7 @@ SQLITE_PRIVATE void sqlite3MemdebugSetType(void *p, u8 eType){
 ** This routine is designed for use within an assert() statement, to
 ** verify the type of an allocation.  For example:
 **
-**     assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
+**     assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
 */
 SQLITE_PRIVATE int sqlite3MemdebugHasType(void *p, u8 eType){
   int rc = 1;
@@ -15462,7 +20975,7 @@ SQLITE_PRIVATE int sqlite3MemdebugHasType(void *p, u8 eType){
 ** This routine is designed for use within an assert() statement, to
 ** verify the type of an allocation.  For example:
 **
-**     assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );
+**     assert( sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
 */
 SQLITE_PRIVATE int sqlite3MemdebugNoType(void *p, u8 eType){
   int rc = 1;
@@ -15511,7 +21024,7 @@ SQLITE_PRIVATE void sqlite3MemdebugSync(){
   for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){
     void **pBt = (void**)pHdr;
     pBt -= pHdr->nBacktraceSlots;
-    mem.xBacktrace(pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);
+    mem.xBacktrace((int)pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);
   }
 }
 
@@ -15600,6 +21113,7 @@ SQLITE_PRIVATE int sqlite3MemdebugMallocCount(){
 ** This version of the memory allocation subsystem is included
 ** in the build only if SQLITE_ENABLE_MEMSYS3 is defined.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is only built into the library
@@ -16052,7 +21566,7 @@ static void memsys3FreeUnsafe(void *pOld){
 */
 static int memsys3Size(void *p){
   Mem3Block *pBlock;
-  if( p==0 ) return 0;
+  assert( p!=0 );
   pBlock = (Mem3Block*)p;
   assert( (pBlock[-1].u.hdr.size4x&1)!=0 );
   return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;
@@ -16291,10 +21805,10 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
 **
 ** This memory allocator uses the following algorithm:
 **
-**   1.  All memory allocations sizes are rounded up to a power of 2.
+**   1.  All memory allocation sizes are rounded up to a power of 2.
 **
 **   2.  If two adjacent free blocks are the halves of a larger block,
-**       then the two blocks are coalesed into the single larger block.
+**       then the two blocks are coalesced into the single larger block.
 **
 **   3.  New memory is allocated from the first available free block.
 **
@@ -16314,6 +21828,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){
 ** The sqlite3_status() logic tracks the maximum values of n and M so
 ** that an application can, at any time, verify this constraint.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** This version of the memory allocator is used only when 
@@ -16367,6 +21882,7 @@ static SQLITE_WSD struct Mem5Global {
   */
   sqlite3_mutex *mutex;
 
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /*
   ** Performance statistics
   */
@@ -16378,11 +21894,12 @@ static SQLITE_WSD struct Mem5Global {
   u32 maxOut;         /* Maximum instantaneous currentOut */
   u32 maxCount;       /* Maximum instantaneous currentCount */
   u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */
+#endif
   
   /*
   ** Lists of free blocks.  aiFreelist[0] is a list of free blocks of
   ** size mem5.szAtom.  aiFreelist[1] holds blocks of size szAtom*2.
-  ** and so forth.
+  ** aiFreelist[2] holds free blocks of size szAtom*4.  And so forth.
   */
   int aiFreelist[LOGMAX+1];
 
@@ -16395,13 +21912,13 @@ static SQLITE_WSD struct Mem5Global {
 } mem5;
 
 /*
-** Access the static variable through a macro for SQLITE_OMIT_WSD
+** Access the static variable through a macro for SQLITE_OMIT_WSD.
 */
 #define mem5 GLOBAL(struct Mem5Global, mem5)
 
 /*
 ** Assuming mem5.zPool is divided up into an array of Mem5Link
-** structures, return a pointer to the idx-th such lik.
+** structures, return a pointer to the idx-th such link.
 */
 #define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.szAtom]))
 
@@ -16448,9 +21965,7 @@ static void memsys5Link(int i, int iLogsize){
 }
 
 /*
-** If the STATIC_MEM mutex is not already held, obtain it now. The mutex
-** will already be held (obtained by code in malloc.c) if
-** sqlite3GlobalConfig.bMemStat is true.
+** Obtain or release the mutex needed to access global data structures.
 */
 static void memsys5Enter(void){
   sqlite3_mutex_enter(mem5.mutex);
@@ -16460,44 +21975,23 @@ static void memsys5Leave(void){
 }
 
 /*
-** Return the size of an outstanding allocation, in bytes.  The
-** size returned omits the 8-byte header overhead.  This only
-** works for chunks that are currently checked out.
+** Return the size of an outstanding allocation, in bytes.
+** This only works for chunks that are currently checked out.
 */
 static int memsys5Size(void *p){
-  int iSize = 0;
-  if( p ){
-    int i = ((u8 *)p-mem5.zPool)/mem5.szAtom;
-    assert( i>=0 && i<mem5.nBlock );
-    iSize = mem5.szAtom * (1 << (mem5.aCtrl[i]&CTRL_LOGSIZE));
-  }
+  int iSize, i;
+  assert( p!=0 );
+  i = (int)(((u8 *)p-mem5.zPool)/mem5.szAtom);
+  assert( i>=0 && i<mem5.nBlock );
+  iSize = mem5.szAtom * (1 << (mem5.aCtrl[i]&CTRL_LOGSIZE));
   return iSize;
 }
 
 /*
-** Find the first entry on the freelist iLogsize.  Unlink that
-** entry and return its index. 
-*/
-static int memsys5UnlinkFirst(int iLogsize){
-  int i;
-  int iFirst;
-
-  assert( iLogsize>=0 && iLogsize<=LOGMAX );
-  i = iFirst = mem5.aiFreelist[iLogsize];
-  assert( iFirst>=0 );
-  while( i>0 ){
-    if( i<iFirst ) iFirst = i;
-    i = MEM5LINK(i)->next;
-  }
-  memsys5Unlink(iFirst, iLogsize);
-  return iFirst;
-}
-
-/*
 ** Return a block of memory of at least nBytes in size.
 ** Return NULL if unable.  Return NULL if nBytes==0.
 **
-** The caller guarantees that nByte positive.
+** The caller guarantees that nByte is positive.
 **
 ** The caller has obtained a mutex prior to invoking this
 ** routine so there is never any chance that two or more
@@ -16512,33 +22006,33 @@ static void *memsys5MallocUnsafe(int nByte){
   /* nByte must be a positive */
   assert( nByte>0 );
 
+  /* No more than 1GiB per allocation */
+  if( nByte > 0x40000000 ) return 0;
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /* Keep track of the maximum allocation request.  Even unfulfilled
   ** requests are counted */
   if( (u32)nByte>mem5.maxRequest ){
     mem5.maxRequest = nByte;
   }
+#endif
 
-  /* Abort if the requested allocation size is larger than the largest
-  ** power of two that we can represent using 32-bit signed integers.
-  */
-  if( nByte > 0x40000000 ){
-    return 0;
-  }
 
   /* Round nByte up to the next valid power of two */
-  for(iFullSz=mem5.szAtom, iLogsize=0; iFullSz<nByte; iFullSz *= 2, iLogsize++){}
+  for(iFullSz=mem5.szAtom,iLogsize=0; iFullSz<nByte; iFullSz*=2,iLogsize++){}
 
   /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
   ** block.  If not, then split a block of the next larger power of
   ** two in order to create a new free block of size iLogsize.
   */
-  for(iBin=iLogsize; mem5.aiFreelist[iBin]<0 && iBin<=LOGMAX; iBin++){}
+  for(iBin=iLogsize; iBin<=LOGMAX && mem5.aiFreelist[iBin]<0; iBin++){}
   if( iBin>LOGMAX ){
     testcase( sqlite3GlobalConfig.xLog!=0 );
     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes", nByte);
     return 0;
   }
-  i = memsys5UnlinkFirst(iBin);
+  i = mem5.aiFreelist[iBin];
+  memsys5Unlink(i, iBin);
   while( iBin>iLogsize ){
     int newSize;
 
@@ -16549,6 +22043,7 @@ static void *memsys5MallocUnsafe(int nByte){
   }
   mem5.aCtrl[i] = iLogsize;
 
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /* Update allocator performance statistics. */
   mem5.nAlloc++;
   mem5.totalAlloc += iFullSz;
@@ -16557,6 +22052,13 @@ static void *memsys5MallocUnsafe(int nByte){
   mem5.currentOut += iFullSz;
   if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount;
   if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut;
+#endif
+
+#ifdef SQLITE_DEBUG
+  /* Make sure the allocated memory does not assume that it is set to zero
+  ** or retains a value from a previous allocation */
+  memset(&mem5.zPool[i*mem5.szAtom], 0xAA, iFullSz);
+#endif
 
   /* Return a pointer to the allocated memory. */
   return (void*)&mem5.zPool[i*mem5.szAtom];
@@ -16572,7 +22074,7 @@ static void memsys5FreeUnsafe(void *pOld){
   /* Set iBlock to the index of the block pointed to by pOld in 
   ** the array of mem5.szAtom byte blocks pointed to by mem5.zPool.
   */
-  iBlock = ((u8 *)pOld-mem5.zPool)/mem5.szAtom;
+  iBlock = (int)(((u8 *)pOld-mem5.zPool)/mem5.szAtom);
 
   /* Check that the pointer pOld points to a valid, non-free block. */
   assert( iBlock>=0 && iBlock<mem5.nBlock );
@@ -16585,23 +22087,26 @@ static void memsys5FreeUnsafe(void *pOld){
 
   mem5.aCtrl[iBlock] |= CTRL_FREE;
   mem5.aCtrl[iBlock+size-1] |= CTRL_FREE;
+
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   assert( mem5.currentCount>0 );
   assert( mem5.currentOut>=(size*mem5.szAtom) );
   mem5.currentCount--;
   mem5.currentOut -= size*mem5.szAtom;
   assert( mem5.currentOut>0 || mem5.currentCount==0 );
   assert( mem5.currentCount>0 || mem5.currentOut==0 );
+#endif
 
   mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;
   while( ALWAYS(iLogsize<LOGMAX) ){
     int iBuddy;
     if( (iBlock>>iLogsize) & 1 ){
       iBuddy = iBlock - size;
+      assert( iBuddy>=0 );
     }else{
       iBuddy = iBlock + size;
+      if( iBuddy>=mem5.nBlock ) break;
     }
-    assert( iBuddy>=0 );
-    if( (iBuddy+(1<<iLogsize))>mem5.nBlock ) break;
     if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
     memsys5Unlink(iBuddy, iLogsize);
     iLogsize++;
@@ -16615,11 +22120,18 @@ static void memsys5FreeUnsafe(void *pOld){
     }
     size *= 2;
   }
+
+#ifdef SQLITE_DEBUG
+  /* Overwrite freed memory with the 0x55 bit pattern to verify that it is
+  ** not used after being freed */
+  memset(&mem5.zPool[iBlock*mem5.szAtom], 0x55, size);
+#endif
+
   memsys5Link(iBlock, iLogsize);
 }
 
 /*
-** Allocate nBytes of memory
+** Allocate nBytes of memory.
 */
 static void *memsys5Malloc(int nBytes){
   sqlite3_int64 *p = 0;
@@ -16669,13 +22181,11 @@ static void *memsys5Realloc(void *pPrior, int nBytes){
   if( nBytes<=nOld ){
     return pPrior;
   }
-  memsys5Enter();
-  p = memsys5MallocUnsafe(nBytes);
+  p = memsys5Malloc(nBytes);
   if( p ){
     memcpy(p, pPrior, nOld);
-    memsys5FreeUnsafe(pPrior);
+    memsys5Free(pPrior);
   }
-  memsys5Leave();
   return p;
 }
 
@@ -16862,6 +22372,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){
 **
 ** This file contains code that is common across all mutex implementations.
 */
+/* #include "sqliteInt.h" */
 
 #if defined(SQLITE_DEBUG) && !defined(SQLITE_MUTEX_OMIT)
 /*
@@ -16870,7 +22381,7 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){
 ** allocate a mutex while the system is uninitialized.
 */
 static SQLITE_WSD int mutexIsInit = 0;
-#endif /* SQLITE_DEBUG */
+#endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */
 
 
 #ifndef SQLITE_MUTEX_OMIT
@@ -16893,11 +22404,18 @@ SQLITE_PRIVATE int sqlite3MutexInit(void){
     }else{
       pFrom = sqlite3NoopMutex();
     }
-    memcpy(pTo, pFrom, offsetof(sqlite3_mutex_methods, xMutexAlloc));
-    memcpy(&pTo->xMutexFree, &pFrom->xMutexFree,
-           sizeof(*pTo) - offsetof(sqlite3_mutex_methods, xMutexFree));
+    pTo->xMutexInit = pFrom->xMutexInit;
+    pTo->xMutexEnd = pFrom->xMutexEnd;
+    pTo->xMutexFree = pFrom->xMutexFree;
+    pTo->xMutexEnter = pFrom->xMutexEnter;
+    pTo->xMutexTry = pFrom->xMutexTry;
+    pTo->xMutexLeave = pFrom->xMutexLeave;
+    pTo->xMutexHeld = pFrom->xMutexHeld;
+    pTo->xMutexNotheld = pFrom->xMutexNotheld;
+    sqlite3MemoryBarrier();
     pTo->xMutexAlloc = pFrom->xMutexAlloc;
   }
+  assert( sqlite3GlobalConfig.mutex.xMutexInit );
   rc = sqlite3GlobalConfig.mutex.xMutexInit();
 
 #ifdef SQLITE_DEBUG
@@ -16927,10 +22445,12 @@ SQLITE_PRIVATE int sqlite3MutexEnd(void){
 /*
 ** Retrieve a pointer to a static mutex or allocate a new dynamic one.
 */
-SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int id){
+SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int id){
 #ifndef SQLITE_OMIT_AUTOINIT
-  if( sqlite3_initialize() ) return 0;
+  if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;
+  if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;
 #endif
+  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
 }
 
@@ -16939,14 +22459,16 @@ SQLITE_PRIVATE sqlite3_mutex *sqlite3MutexAlloc(int id){
     return 0;
   }
   assert( GLOBAL(int, mutexIsInit) );
+  assert( sqlite3GlobalConfig.mutex.xMutexAlloc );
   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);
 }
 
 /*
 ** Free a dynamic mutex.
 */
-SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexFree );
     sqlite3GlobalConfig.mutex.xMutexFree(p);
   }
 }
@@ -16955,8 +22477,9 @@ SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){
 ** Obtain the mutex p. If some other thread already has the mutex, block
 ** until it can be obtained.
 */
-SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexEnter );
     sqlite3GlobalConfig.mutex.xMutexEnter(p);
   }
 }
@@ -16965,9 +22488,10 @@ SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){
 ** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another
 ** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.
 */
-SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex *p){
   int rc = SQLITE_OK;
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexTry );
     return sqlite3GlobalConfig.mutex.xMutexTry(p);
   }
   return rc;
@@ -16979,8 +22503,9 @@ SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){
 ** is not currently entered. If a NULL pointer is passed as an argument
 ** this function is a no-op.
 */
-SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
+SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex *p){
   if( p ){
+    assert( sqlite3GlobalConfig.mutex.xMutexLeave );
     sqlite3GlobalConfig.mutex.xMutexLeave(p);
   }
 }
@@ -16990,15 +22515,17 @@ SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){
 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
 ** intended for use inside assert() statements.
 */
-SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex *p){
+  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexHeld );
   return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);
 }
-SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex *p){
+  assert( p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld );
   return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);
 }
 #endif
 
-#endif /* SQLITE_MUTEX_OMIT */
+#endif /* !defined(SQLITE_MUTEX_OMIT) */
 
 /************** End of mutex.c ***********************************************/
 /************** Begin file mutex_noop.c **************************************/
@@ -17029,6 +22556,7 @@ SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){
 ** that does error checking on mutexes to make sure they are being
 ** called correctly.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_MUTEX_OMIT
 
@@ -17110,7 +22638,7 @@ static int debugMutexEnd(void){ return SQLITE_OK; }
 ** that means that a mutex could not be allocated. 
 */
 static sqlite3_mutex *debugMutexAlloc(int id){
-  static sqlite3_debug_mutex aStatic[6];
+  static sqlite3_debug_mutex aStatic[SQLITE_MUTEX_STATIC_VFS3 - 1];
   sqlite3_debug_mutex *pNew = 0;
   switch( id ){
     case SQLITE_MUTEX_FAST:
@@ -17123,8 +22651,12 @@ static sqlite3_mutex *debugMutexAlloc(int id){
       break;
     }
     default: {
-      assert( id-2 >= 0 );
-      assert( id-2 < (int)(sizeof(aStatic)/sizeof(aStatic[0])) );
+#ifdef SQLITE_ENABLE_API_ARMOR
+      if( id-2<0 || id-2>=ArraySize(aStatic) ){
+        (void)SQLITE_MISUSE_BKPT;
+        return 0;
+      }
+#endif
       pNew = &aStatic[id-2];
       pNew->id = id;
       break;
@@ -17139,8 +22671,13 @@ static sqlite3_mutex *debugMutexAlloc(int id){
 static void debugMutexFree(sqlite3_mutex *pX){
   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;
   assert( p->cnt==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-  sqlite3_free(p);
+  if( p->id==SQLITE_MUTEX_RECURSIVE || p->id==SQLITE_MUTEX_FAST ){
+    sqlite3_free(p);
+  }else{
+#ifdef SQLITE_ENABLE_API_ARMOR
+    (void)SQLITE_MISUSE_BKPT;
+#endif
+  }
 }
 
 /*
@@ -17205,286 +22742,10 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3NoopMutex(void){
 SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
   return sqlite3NoopMutex();
 }
-#endif /* SQLITE_MUTEX_NOOP */
-#endif /* SQLITE_MUTEX_OMIT */
+#endif /* defined(SQLITE_MUTEX_NOOP) */
+#endif /* !defined(SQLITE_MUTEX_OMIT) */
 
 /************** End of mutex_noop.c ******************************************/
-/************** Begin file mutex_os2.c ***************************************/
-/*
-** 2007 August 28
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This file contains the C functions that implement mutexes for OS/2
-*/
-
-/*
-** The code in this file is only used if SQLITE_MUTEX_OS2 is defined.
-** See the mutex.h file for details.
-*/
-#ifdef SQLITE_MUTEX_OS2
-
-/********************** OS/2 Mutex Implementation **********************
-**
-** This implementation of mutexes is built using the OS/2 API.
-*/
-
-/*
-** The mutex object
-** Each recursive mutex is an instance of the following structure.
-*/
-struct sqlite3_mutex {
-  HMTX mutex;       /* Mutex controlling the lock */
-  int  id;          /* Mutex type */
-#ifdef SQLITE_DEBUG
- int   trace;       /* True to trace changes */
-#endif
-};
-
-#ifdef SQLITE_DEBUG
-#define SQLITE3_MUTEX_INITIALIZER { 0, 0, 0 }
-#else
-#define SQLITE3_MUTEX_INITIALIZER { 0, 0 }
-#endif
-
-/*
-** Initialize and deinitialize the mutex subsystem.
-*/
-static int os2MutexInit(void){ return SQLITE_OK; }
-static int os2MutexEnd(void){ return SQLITE_OK; }
-
-/*
-** The sqlite3_mutex_alloc() routine allocates a new
-** mutex and returns a pointer to it.  If it returns NULL
-** that means that a mutex could not be allocated. 
-** SQLite will unwind its stack and return an error.  The argument
-** to sqlite3_mutex_alloc() is one of these integer constants:
-**
-** <ul>
-** <li>  SQLITE_MUTEX_FAST
-** <li>  SQLITE_MUTEX_RECURSIVE
-** <li>  SQLITE_MUTEX_STATIC_MASTER
-** <li>  SQLITE_MUTEX_STATIC_MEM
-** <li>  SQLITE_MUTEX_STATIC_MEM2
-** <li>  SQLITE_MUTEX_STATIC_PRNG
-** <li>  SQLITE_MUTEX_STATIC_LRU
-** <li>  SQLITE_MUTEX_STATIC_LRU2
-** </ul>
-**
-** The first two constants cause sqlite3_mutex_alloc() to create
-** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
-** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
-** The mutex implementation does not need to make a distinction
-** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
-** not want to.  But SQLite will only request a recursive mutex in
-** cases where it really needs one.  If a faster non-recursive mutex
-** implementation is available on the host platform, the mutex subsystem
-** might return such a mutex in response to SQLITE_MUTEX_FAST.
-**
-** The other allowed parameters to sqlite3_mutex_alloc() each return
-** a pointer to a static preexisting mutex.  Six static mutexes are
-** used by the current version of SQLite.  Future versions of SQLite
-** may add additional static mutexes.  Static mutexes are for internal
-** use by SQLite only.  Applications that use SQLite mutexes should
-** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
-** SQLITE_MUTEX_RECURSIVE.
-**
-** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
-** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
-** returns a different mutex on every call.  But for the static
-** mutex types, the same mutex is returned on every call that has
-** the same type number.
-*/
-static sqlite3_mutex *os2MutexAlloc(int iType){
-  sqlite3_mutex *p = NULL;
-  switch( iType ){
-    case SQLITE_MUTEX_FAST:
-    case SQLITE_MUTEX_RECURSIVE: {
-      p = sqlite3MallocZero( sizeof(*p) );
-      if( p ){
-        p->id = iType;
-        if( DosCreateMutexSem( 0, &p->mutex, 0, FALSE ) != NO_ERROR ){
-          sqlite3_free( p );
-          p = NULL;
-        }
-      }
-      break;
-    }
-    default: {
-      static volatile int isInit = 0;
-      static sqlite3_mutex staticMutexes[6] = {
-        SQLITE3_MUTEX_INITIALIZER,
-        SQLITE3_MUTEX_INITIALIZER,
-        SQLITE3_MUTEX_INITIALIZER,
-        SQLITE3_MUTEX_INITIALIZER,
-        SQLITE3_MUTEX_INITIALIZER,
-        SQLITE3_MUTEX_INITIALIZER,
-      };
-      if ( !isInit ){
-        APIRET rc;
-        PTIB ptib;
-        PPIB ppib;
-        HMTX mutex;
-        char name[32];
-        DosGetInfoBlocks( &ptib, &ppib );
-        sqlite3_snprintf( sizeof(name), name, "\\SEM32\\SQLITE%04x",
-                          ppib->pib_ulpid );
-        while( !isInit ){
-          mutex = 0;
-          rc = DosCreateMutexSem( name, &mutex, 0, FALSE);
-          if( rc == NO_ERROR ){
-            unsigned int i;
-            if( !isInit ){
-              for( i = 0; i < sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++ ){
-                DosCreateMutexSem( 0, &staticMutexes[i].mutex, 0, FALSE );
-              }
-              isInit = 1;
-            }
-            DosCloseMutexSem( mutex );
-          }else if( rc == ERROR_DUPLICATE_NAME ){
-            DosSleep( 1 );
-          }else{
-            return p;
-          }
-        }
-      }
-      assert( iType-2 >= 0 );
-      assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
-      p = &staticMutexes[iType-2];
-      p->id = iType;
-      break;
-    }
-  }
-  return p;
-}
-
-
-/*
-** This routine deallocates a previously allocated mutex.
-** SQLite is careful to deallocate every mutex that it allocates.
-*/
-static void os2MutexFree(sqlite3_mutex *p){
-#ifdef SQLITE_DEBUG
-  TID tid;
-  PID pid;
-  ULONG ulCount;
-  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
-  assert( ulCount==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-#endif
-  DosCloseMutexSem( p->mutex );
-  sqlite3_free( p );
-}
-
-#ifdef SQLITE_DEBUG
-/*
-** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
-** intended for use inside assert() statements.
-*/
-static int os2MutexHeld(sqlite3_mutex *p){
-  TID tid;
-  PID pid;
-  ULONG ulCount;
-  PTIB ptib;
-  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
-  if( ulCount==0 || ( ulCount>1 && p->id!=SQLITE_MUTEX_RECURSIVE ) )
-    return 0;
-  DosGetInfoBlocks(&ptib, NULL);
-  return tid==ptib->tib_ptib2->tib2_ultid;
-}
-static int os2MutexNotheld(sqlite3_mutex *p){
-  TID tid;
-  PID pid;
-  ULONG ulCount;
-  PTIB ptib;
-  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
-  if( ulCount==0 )
-    return 1;
-  DosGetInfoBlocks(&ptib, NULL);
-  return tid!=ptib->tib_ptib2->tib2_ultid;
-}
-static void os2MutexTrace(sqlite3_mutex *p, char *pAction){
-  TID   tid;
-  PID   pid;
-  ULONG ulCount;
-  DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
-  printf("%s mutex %p (%d) with nRef=%ld\n", pAction, (void*)p, p->trace, ulCount);
-}
-#endif
-
-/*
-** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
-** to enter a mutex.  If another thread is already within the mutex,
-** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
-** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
-** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
-** be entered multiple times by the same thread.  In such cases the,
-** mutex must be exited an equal number of times before another thread
-** can enter.  If the same thread tries to enter any other kind of mutex
-** more than once, the behavior is undefined.
-*/
-static void os2MutexEnter(sqlite3_mutex *p){
-  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
-  DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
-#ifdef SQLITE_DEBUG
-  if( p->trace ) os2MutexTrace(p, "enter");
-#endif
-}
-static int os2MutexTry(sqlite3_mutex *p){
-  int rc = SQLITE_BUSY;
-  assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
-  if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR ) {
-    rc = SQLITE_OK;
-#ifdef SQLITE_DEBUG
-    if( p->trace ) os2MutexTrace(p, "try");
-#endif
-  }
-  return rc;
-}
-
-/*
-** The sqlite3_mutex_leave() routine exits a mutex that was
-** previously entered by the same thread.  The behavior
-** is undefined if the mutex is not currently entered or
-** is not currently allocated.  SQLite will never do either.
-*/
-static void os2MutexLeave(sqlite3_mutex *p){
-  assert( os2MutexHeld(p) );
-  DosReleaseMutexSem(p->mutex);
-#ifdef SQLITE_DEBUG
-  if( p->trace ) os2MutexTrace(p, "leave");
-#endif
-}
-
-SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
-  static const sqlite3_mutex_methods sMutex = {
-    os2MutexInit,
-    os2MutexEnd,
-    os2MutexAlloc,
-    os2MutexFree,
-    os2MutexEnter,
-    os2MutexTry,
-    os2MutexLeave,
-#ifdef SQLITE_DEBUG
-    os2MutexHeld,
-    os2MutexNotheld
-#else
-    0,
-    0
-#endif
-  };
-
-  return &sMutex;
-}
-#endif /* SQLITE_MUTEX_OS2 */
-
-/************** End of mutex_os2.c *******************************************/
 /************** Begin file mutex_unix.c **************************************/
 /*
 ** 2007 August 28
@@ -17499,6 +22760,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 *************************************************************************
 ** This file contains the C functions that implement mutexes for pthreads
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** The code in this file is only used if we are compiling threadsafe
@@ -17527,15 +22789,19 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 */
 struct sqlite3_mutex {
   pthread_mutex_t mutex;     /* Mutex controlling the lock */
-#if SQLITE_MUTEX_NREF
+#if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)
   int id;                    /* Mutex type */
+#endif
+#if SQLITE_MUTEX_NREF
   volatile int nRef;         /* Number of entrances */
   volatile pthread_t owner;  /* Thread that is within this mutex */
   int trace;                 /* True to trace changes */
 #endif
 };
 #if SQLITE_MUTEX_NREF
-#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0, 0 }
+#define SQLITE3_MUTEX_INITIALIZER {PTHREAD_MUTEX_INITIALIZER,0,0,(pthread_t)0,0}
+#elif defined(SQLITE_ENABLE_API_ARMOR)
+#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0 }
 #else
 #define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
 #endif
@@ -17566,6 +22832,19 @@ static int pthreadMutexNotheld(sqlite3_mutex *p){
 #endif
 
 /*
+** Try to provide a memory barrier operation, needed for initialization
+** and also for the implementation of xShmBarrier in the VFS in cases
+** where SQLite is compiled without mutexes.
+*/
+SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
+#if defined(SQLITE_MEMORY_BARRIER)
+  SQLITE_MEMORY_BARRIER;
+#elif defined(__GNUC__) && GCC_VERSION>=4001000
+  __sync_synchronize();
+#endif
+}
+
+/*
 ** Initialize and deinitialize the mutex subsystem.
 */
 static int pthreadMutexInit(void){ return SQLITE_OK; }
@@ -17583,10 +22862,16 @@ static int pthreadMutexEnd(void){ return SQLITE_OK; }
 ** <li>  SQLITE_MUTEX_RECURSIVE
 ** <li>  SQLITE_MUTEX_STATIC_MASTER
 ** <li>  SQLITE_MUTEX_STATIC_MEM
-** <li>  SQLITE_MUTEX_STATIC_MEM2
+** <li>  SQLITE_MUTEX_STATIC_OPEN
 ** <li>  SQLITE_MUTEX_STATIC_PRNG
 ** <li>  SQLITE_MUTEX_STATIC_LRU
 ** <li>  SQLITE_MUTEX_STATIC_PMEM
+** <li>  SQLITE_MUTEX_STATIC_APP1
+** <li>  SQLITE_MUTEX_STATIC_APP2
+** <li>  SQLITE_MUTEX_STATIC_APP3
+** <li>  SQLITE_MUTEX_STATIC_VFS1
+** <li>  SQLITE_MUTEX_STATIC_VFS2
+** <li>  SQLITE_MUTEX_STATIC_VFS3
 ** </ul>
 **
 ** The first two constants cause sqlite3_mutex_alloc() to create
@@ -17620,6 +22905,12 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
     SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
     SQLITE3_MUTEX_INITIALIZER
   };
   sqlite3_mutex *p;
@@ -17639,32 +22930,30 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
         pthread_mutex_init(&p->mutex, &recursiveAttr);
         pthread_mutexattr_destroy(&recursiveAttr);
 #endif
-#if SQLITE_MUTEX_NREF
-        p->id = iType;
-#endif
       }
       break;
     }
     case SQLITE_MUTEX_FAST: {
       p = sqlite3MallocZero( sizeof(*p) );
       if( p ){
-#if SQLITE_MUTEX_NREF
-        p->id = iType;
-#endif
         pthread_mutex_init(&p->mutex, 0);
       }
       break;
     }
     default: {
-      assert( iType-2 >= 0 );
-      assert( iType-2 < ArraySize(staticMutexes) );
-      p = &staticMutexes[iType-2];
-#if SQLITE_MUTEX_NREF
-      p->id = iType;
+#ifdef SQLITE_ENABLE_API_ARMOR
+      if( iType-2<0 || iType-2>=ArraySize(staticMutexes) ){
+        (void)SQLITE_MISUSE_BKPT;
+        return 0;
+      }
 #endif
+      p = &staticMutexes[iType-2];
       break;
     }
   }
+#if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)
+  if( p ) p->id = iType;
+#endif
   return p;
 }
 
@@ -17676,9 +22965,18 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){
 */
 static void pthreadMutexFree(sqlite3_mutex *p){
   assert( p->nRef==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-  pthread_mutex_destroy(&p->mutex);
-  sqlite3_free(p);
+#if SQLITE_ENABLE_API_ARMOR
+  if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE )
+#endif
+  {
+    pthread_mutex_destroy(&p->mutex);
+    sqlite3_free(p);
+  }
+#ifdef SQLITE_ENABLE_API_ARMOR
+  else{
+    (void)SQLITE_MISUSE_BKPT;
+  }
+#endif
 }
 
 /*
@@ -17835,7 +23133,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
   return &sMutex;
 }
 
-#endif /* SQLITE_MUTEX_PTHREAD */
+#endif /* SQLITE_MUTEX_PTHREADS */
 
 /************** End of mutex_unix.c ******************************************/
 /************** Begin file mutex_w32.c ***************************************/
@@ -17850,12 +23148,315 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file contains the C functions that implement mutexes for win32
+** This file contains the C functions that implement mutexes for Win32.
+*/
+/* #include "sqliteInt.h" */
+
+#if SQLITE_OS_WIN
+/*
+** Include code that is common to all os_*.c files
+*/
+/************** Include os_common.h in the middle of mutex_w32.c *************/
+/************** Begin file os_common.h ***************************************/
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains macros and a little bit of code that is common to
+** all of the platform-specific files (os_*.c) and is #included into those
+** files.
+**
+** This file should be #included by the os_*.c files only.  It is not a
+** general purpose header file.
+*/
+#ifndef _OS_COMMON_H_
+#define _OS_COMMON_H_
+
+/*
+** At least two bugs have slipped in because we changed the MEMORY_DEBUG
+** macro to SQLITE_DEBUG and some older makefiles have not yet made the
+** switch.  The following code should catch this problem at compile-time.
+*/
+#ifdef MEMORY_DEBUG
+# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
+#endif
+
+/*
+** Macros for performance tracing.  Normally turned off.  Only works
+** on i486 hardware.
+*/
+#ifdef SQLITE_PERFORMANCE_TRACE
+
+/*
+** hwtime.h contains inline assembler code for implementing
+** high-performance timing routines.
+*/
+/************** Include hwtime.h in the middle of os_common.h ****************/
+/************** Begin file hwtime.h ******************************************/
+/*
+** 2008 May 27
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains inline asm code for retrieving "high-performance"
+** counters for x86 class CPUs.
 */
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
+
+/*
+** The following routine only works on pentium-class (or newer) processors.
+** It uses the RDTSC opcode to read the cycle count value out of the
+** processor and returns that value.  This can be used for high-res
+** profiling.
+*/
+#if (defined(__GNUC__) || defined(_MSC_VER)) && \
+      (defined(i386) || defined(__i386__) || defined(_M_IX86))
+
+  #if defined(__GNUC__)
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+     unsigned int lo, hi;
+     __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
+     return (sqlite_uint64)hi << 32 | lo;
+  }
+
+  #elif defined(_MSC_VER)
+
+  __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
+     __asm {
+        rdtsc
+        ret       ; return value at EDX:EAX
+     }
+  }
+
+  #endif
+
+#elif (defined(__GNUC__) && defined(__x86_64__))
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+      unsigned long val;
+      __asm__ __volatile__ ("rdtsc" : "=A" (val));
+      return val;
+  }
+ 
+#elif (defined(__GNUC__) && defined(__ppc__))
+
+  __inline__ sqlite_uint64 sqlite3Hwtime(void){
+      unsigned long long retval;
+      unsigned long junk;
+      __asm__ __volatile__ ("\n\
+          1:      mftbu   %1\n\
+                  mftb    %L0\n\
+                  mftbu   %0\n\
+                  cmpw    %0,%1\n\
+                  bne     1b"
+                  : "=r" (retval), "=r" (junk));
+      return retval;
+  }
+
+#else
+
+  #error Need implementation of sqlite3Hwtime() for your platform.
+
+  /*
+  ** To compile without implementing sqlite3Hwtime() for your platform,
+  ** you can remove the above #error and use the following
+  ** stub function.  You will lose timing support for many
+  ** of the debugging and testing utilities, but it should at
+  ** least compile and run.
+  */
+SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
+
+#endif
+
+#endif /* !defined(SQLITE_HWTIME_H) */
+
+/************** End of hwtime.h **********************************************/
+/************** Continuing where we left off in os_common.h ******************/
+
+static sqlite_uint64 g_start;
+static sqlite_uint64 g_elapsed;
+#define TIMER_START       g_start=sqlite3Hwtime()
+#define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start
+#define TIMER_ELAPSED     g_elapsed
+#else
+#define TIMER_START
+#define TIMER_END
+#define TIMER_ELAPSED     ((sqlite_uint64)0)
+#endif
+
+/*
+** If we compile with the SQLITE_TEST macro set, then the following block
+** of code will give us the ability to simulate a disk I/O error.  This
+** is used for testing the I/O recovery logic.
+*/
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
+#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
+#define SimulateIOError(CODE)  \
+  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
+       || sqlite3_io_error_pending-- == 1 )  \
+              { local_ioerr(); CODE; }
+static void local_ioerr(){
+  IOTRACE(("IOERR\n"));
+  sqlite3_io_error_hit++;
+  if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;
+}
+#define SimulateDiskfullError(CODE) \
+   if( sqlite3_diskfull_pending ){ \
+     if( sqlite3_diskfull_pending == 1 ){ \
+       local_ioerr(); \
+       sqlite3_diskfull = 1; \
+       sqlite3_io_error_hit = 1; \
+       CODE; \
+     }else{ \
+       sqlite3_diskfull_pending--; \
+     } \
+   }
+#else
+#define SimulateIOErrorBenign(X)
+#define SimulateIOError(A)
+#define SimulateDiskfullError(A)
+#endif /* defined(SQLITE_TEST) */
+
+/*
+** When testing, keep a count of the number of open files.
+*/
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
+#define OpenCounter(X)  sqlite3_open_file_count+=(X)
+#else
+#define OpenCounter(X)
+#endif /* defined(SQLITE_TEST) */
+
+#endif /* !defined(_OS_COMMON_H_) */
+
+/************** End of os_common.h *******************************************/
+/************** Continuing where we left off in mutex_w32.c ******************/
+
+/*
+** Include the header file for the Windows VFS.
+*/
+/************** Include os_win.h in the middle of mutex_w32.c ****************/
+/************** Begin file os_win.h ******************************************/
+/*
+** 2013 November 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that is specific to Windows.
+*/
+#ifndef SQLITE_OS_WIN_H
+#define SQLITE_OS_WIN_H
+
+/*
+** Include the primary Windows SDK header file.
+*/
+#include "windows.h"
+
+#ifdef __CYGWIN__
+# include <sys/cygwin.h>
+# include <errno.h> /* amalgamator: dontcache */
+#endif
+
+/*
+** Determine if we are dealing with Windows NT.
+**
+** We ought to be able to determine if we are compiling for Windows 9x or
+** Windows NT using the _WIN32_WINNT macro as follows:
+**
+** #if defined(_WIN32_WINNT)
+** # define SQLITE_OS_WINNT 1
+** #else
+** # define SQLITE_OS_WINNT 0
+** #endif
+**
+** However, Visual Studio 2005 does not set _WIN32_WINNT by default, as
+** it ought to, so the above test does not work.  We'll just assume that
+** everything is Windows NT unless the programmer explicitly says otherwise
+** by setting SQLITE_OS_WINNT to 0.
+*/
+#if SQLITE_OS_WIN && !defined(SQLITE_OS_WINNT)
+# define SQLITE_OS_WINNT 1
+#endif
+
+/*
+** Determine if we are dealing with Windows CE - which has a much reduced
+** API.
+*/
+#if defined(_WIN32_WCE)
+# define SQLITE_OS_WINCE 1
+#else
+# define SQLITE_OS_WINCE 0
+#endif
+
+/*
+** Determine if we are dealing with WinRT, which provides only a subset of
+** the full Win32 API.
+*/
+#if !defined(SQLITE_OS_WINRT)
+# define SQLITE_OS_WINRT 0
+#endif
+
+/*
+** For WinCE, some API function parameters do not appear to be declared as
+** volatile.
+*/
+#if SQLITE_OS_WINCE
+# define SQLITE_WIN32_VOLATILE
+#else
+# define SQLITE_WIN32_VOLATILE volatile
+#endif
+
+/*
+** For some Windows sub-platforms, the _beginthreadex() / _endthreadex()
+** functions are not available (e.g. those not using MSVC, Cygwin, etc).
+*/
+#if SQLITE_OS_WIN && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
+    SQLITE_THREADSAFE>0 && !defined(__CYGWIN__)
+# define SQLITE_OS_WIN_THREADS 1
+#else
+# define SQLITE_OS_WIN_THREADS 0
+#endif
+
+#endif /* SQLITE_OS_WIN_H */
+
+/************** End of os_win.h **********************************************/
+/************** Continuing where we left off in mutex_w32.c ******************/
+#endif
 
 /*
 ** The code in this file is only used if we are compiling multithreaded
-** on a win32 system.
+** on a Win32 system.
 */
 #ifdef SQLITE_MUTEX_W32
 
@@ -17868,48 +23469,22 @@ struct sqlite3_mutex {
 #ifdef SQLITE_DEBUG
   volatile int nRef;         /* Number of enterances */
   volatile DWORD owner;      /* Thread holding this mutex */
-  int trace;                 /* True to trace changes */
+  volatile int trace;        /* True to trace changes */
 #endif
 };
-#define SQLITE_W32_MUTEX_INITIALIZER { 0 }
-#ifdef SQLITE_DEBUG
-#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0, 0L, (DWORD)0, 0 }
-#else
-#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 }
-#endif
 
 /*
-** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
-** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
-**
-** Here is an interesting observation:  Win95, Win98, and WinME lack
-** the LockFileEx() API.  But we can still statically link against that
-** API as long as we don't call it win running Win95/98/ME.  A call to
-** this routine is used to determine if the host is Win95/98/ME or
-** WinNT/2K/XP so that we will know whether or not we can safely call
-** the LockFileEx() API.
-**
-** mutexIsNT() is only used for the TryEnterCriticalSection() API call,
-** which is only available if your application was compiled with 
-** _WIN32_WINNT defined to a value >= 0x0400.  Currently, the only
-** call to TryEnterCriticalSection() is #ifdef'ed out, so #ifdef 
-** this out as well.
+** These are the initializer values used when declaring a "static" mutex
+** on Win32.  It should be noted that all mutexes require initialization
+** on the Win32 platform.
 */
-#if 0
-#if SQLITE_OS_WINCE
-# define mutexIsNT()  (1)
+#define SQLITE_W32_MUTEX_INITIALIZER { 0 }
+
+#ifdef SQLITE_DEBUG
+#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0, \
+                                    0L, (DWORD)0, 0 }
 #else
-  static int mutexIsNT(void){
-    static int osType = 0;
-    if( osType==0 ){
-      OSVERSIONINFO sInfo;
-      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
-      GetVersionEx(&sInfo);
-      osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
-    }
-    return osType==2;
-  }
-#endif /* SQLITE_OS_WINCE */
+#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 }
 #endif
 
 #ifdef SQLITE_DEBUG
@@ -17920,20 +23495,45 @@ struct sqlite3_mutex {
 static int winMutexHeld(sqlite3_mutex *p){
   return p->nRef!=0 && p->owner==GetCurrentThreadId();
 }
+
 static int winMutexNotheld2(sqlite3_mutex *p, DWORD tid){
   return p->nRef==0 || p->owner!=tid;
 }
+
 static int winMutexNotheld(sqlite3_mutex *p){
-  DWORD tid = GetCurrentThreadId(); 
+  DWORD tid = GetCurrentThreadId();
   return winMutexNotheld2(p, tid);
 }
 #endif
 
+/*
+** Try to provide a memory barrier operation, needed for initialization
+** and also for the xShmBarrier method of the VFS in cases when SQLite is
+** compiled without mutexes (SQLITE_THREADSAFE=0).
+*/
+SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
+#if defined(SQLITE_MEMORY_BARRIER)
+  SQLITE_MEMORY_BARRIER;
+#elif defined(__GNUC__)
+  __sync_synchronize();
+#elif !defined(SQLITE_DISABLE_INTRINSIC) && \
+      defined(_MSC_VER) && _MSC_VER>=1300
+  _ReadWriteBarrier();
+#elif defined(MemoryBarrier)
+  MemoryBarrier();
+#endif
+}
 
 /*
 ** Initialize and deinitialize the mutex subsystem.
 */
-static sqlite3_mutex winMutex_staticMutexes[6] = {
+static sqlite3_mutex winMutex_staticMutexes[] = {
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
+  SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER,
@@ -17941,33 +23541,43 @@ static sqlite3_mutex winMutex_staticMutexes[6] = {
   SQLITE3_MUTEX_INITIALIZER,
   SQLITE3_MUTEX_INITIALIZER
 };
+
 static int winMutex_isInit = 0;
-/* As winMutexInit() and winMutexEnd() are called as part
-** of the sqlite3_initialize and sqlite3_shutdown()
-** processing, the "interlocked" magic is probably not
-** strictly necessary.
+static int winMutex_isNt = -1; /* <0 means "need to query" */
+
+/* As the winMutexInit() and winMutexEnd() functions are called as part
+** of the sqlite3_initialize() and sqlite3_shutdown() processing, the
+** "interlocked" magic used here is probably not strictly necessary.
 */
-static long winMutex_lock = 0;
+static LONG SQLITE_WIN32_VOLATILE winMutex_lock = 0;
 
-static int winMutexInit(void){ 
+SQLITE_API int SQLITE_STDCALL sqlite3_win32_is_nt(void); /* os_win.c */
+SQLITE_API void SQLITE_STDCALL sqlite3_win32_sleep(DWORD milliseconds); /* os_win.c */
+
+static int winMutexInit(void){
   /* The first to increment to 1 does actual initialization */
   if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){
     int i;
     for(i=0; i<ArraySize(winMutex_staticMutexes); i++){
+#if SQLITE_OS_WINRT
+      InitializeCriticalSectionEx(&winMutex_staticMutexes[i].mutex, 0, 0);
+#else
       InitializeCriticalSection(&winMutex_staticMutexes[i].mutex);
+#endif
     }
     winMutex_isInit = 1;
   }else{
-    /* Someone else is in the process of initing the static mutexes */
+    /* Another thread is (in the process of) initializing the static
+    ** mutexes */
     while( !winMutex_isInit ){
-      Sleep(1);
+      sqlite3_win32_sleep(1);
     }
   }
-  return SQLITE_OK; 
+  return SQLITE_OK;
 }
 
-static int winMutexEnd(void){ 
-  /* The first to decrement to 0 does actual shutdown 
+static int winMutexEnd(void){
+  /* The first to decrement to 0 does actual shutdown
   ** (which should be the last to shutdown.) */
   if( InterlockedCompareExchange(&winMutex_lock, 0, 1)==1 ){
     if( winMutex_isInit==1 ){
@@ -17978,7 +23588,7 @@ static int winMutexEnd(void){
       winMutex_isInit = 0;
     }
   }
-  return SQLITE_OK; 
+  return SQLITE_OK;
 }
 
 /*
@@ -17993,10 +23603,16 @@ static int winMutexEnd(void){
 ** <li>  SQLITE_MUTEX_RECURSIVE
 ** <li>  SQLITE_MUTEX_STATIC_MASTER
 ** <li>  SQLITE_MUTEX_STATIC_MEM
-** <li>  SQLITE_MUTEX_STATIC_MEM2
+** <li>  SQLITE_MUTEX_STATIC_OPEN
 ** <li>  SQLITE_MUTEX_STATIC_PRNG
 ** <li>  SQLITE_MUTEX_STATIC_LRU
 ** <li>  SQLITE_MUTEX_STATIC_PMEM
+** <li>  SQLITE_MUTEX_STATIC_APP1
+** <li>  SQLITE_MUTEX_STATIC_APP2
+** <li>  SQLITE_MUTEX_STATIC_APP3
+** <li>  SQLITE_MUTEX_STATIC_VFS1
+** <li>  SQLITE_MUTEX_STATIC_VFS2
+** <li>  SQLITE_MUTEX_STATIC_VFS3
 ** </ul>
 **
 ** The first two constants cause sqlite3_mutex_alloc() to create
@@ -18019,7 +23635,7 @@ static int winMutexEnd(void){
 **
 ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
-** returns a different mutex on every call.  But for the static 
+** returns a different mutex on every call.  But for the static
 ** mutex types, the same mutex is returned on every call that has
 ** the same type number.
 */
@@ -18030,21 +23646,34 @@ static sqlite3_mutex *winMutexAlloc(int iType){
     case SQLITE_MUTEX_FAST:
     case SQLITE_MUTEX_RECURSIVE: {
       p = sqlite3MallocZero( sizeof(*p) );
-      if( p ){  
-#ifdef SQLITE_DEBUG
+      if( p ){
         p->id = iType;
+#ifdef SQLITE_DEBUG
+#ifdef SQLITE_WIN32_MUTEX_TRACE_DYNAMIC
+        p->trace = 1;
+#endif
 #endif
+#if SQLITE_OS_WINRT
+        InitializeCriticalSectionEx(&p->mutex, 0, 0);
+#else
         InitializeCriticalSection(&p->mutex);
+#endif
       }
       break;
     }
     default: {
-      assert( winMutex_isInit==1 );
-      assert( iType-2 >= 0 );
-      assert( iType-2 < ArraySize(winMutex_staticMutexes) );
+#ifdef SQLITE_ENABLE_API_ARMOR
+      if( iType-2<0 || iType-2>=ArraySize(winMutex_staticMutexes) ){
+        (void)SQLITE_MISUSE_BKPT;
+        return 0;
+      }
+#endif
       p = &winMutex_staticMutexes[iType-2];
-#ifdef SQLITE_DEBUG
       p->id = iType;
+#ifdef SQLITE_DEBUG
+#ifdef SQLITE_WIN32_MUTEX_TRACE_STATIC
+      p->trace = 1;
+#endif
 #endif
       break;
     }
@@ -18061,9 +23690,14 @@ static sqlite3_mutex *winMutexAlloc(int iType){
 static void winMutexFree(sqlite3_mutex *p){
   assert( p );
   assert( p->nRef==0 && p->owner==0 );
-  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
-  DeleteCriticalSection(&p->mutex);
-  sqlite3_free(p);
+  if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ){
+    DeleteCriticalSection(&p->mutex);
+    sqlite3_free(p);
+  }else{
+#ifdef SQLITE_ENABLE_API_ARMOR
+    (void)SQLITE_MISUSE_BKPT;
+#endif
+  }
 }
 
 /*
@@ -18078,30 +23712,39 @@ static void winMutexFree(sqlite3_mutex *p){
 ** more than once, the behavior is undefined.
 */
 static void winMutexEnter(sqlite3_mutex *p){
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
+  DWORD tid = GetCurrentThreadId();
+#endif
 #ifdef SQLITE_DEBUG
-  DWORD tid = GetCurrentThreadId(); 
+  assert( p );
   assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) );
+#else
+  assert( p );
 #endif
+  assert( winMutex_isInit==1 );
   EnterCriticalSection(&p->mutex);
 #ifdef SQLITE_DEBUG
   assert( p->nRef>0 || p->owner==0 );
-  p->owner = tid; 
+  p->owner = tid;
   p->nRef++;
   if( p->trace ){
-    printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+    OSTRACE(("ENTER-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n",
+             tid, p, p->trace, p->nRef));
   }
 #endif
 }
+
 static int winMutexTry(sqlite3_mutex *p){
-#ifndef NDEBUG
-  DWORD tid = GetCurrentThreadId(); 
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
+  DWORD tid = GetCurrentThreadId();
 #endif
   int rc = SQLITE_BUSY;
+  assert( p );
   assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) );
   /*
   ** The sqlite3_mutex_try() routine is very rarely used, and when it
   ** is used it is merely an optimization.  So it is OK for it to always
-  ** fail.  
+  ** fail.
   **
   ** The TryEnterCriticalSection() interface is only available on WinNT.
   ** And some windows compilers complain if you try to use it without
@@ -18109,18 +23752,27 @@ static int winMutexTry(sqlite3_mutex *p){
   ** For that reason, we will omit this optimization for now.  See
   ** ticket #2685.
   */
-#if 0
-  if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
+#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0400
+  assert( winMutex_isInit==1 );
+  assert( winMutex_isNt>=-1 && winMutex_isNt<=1 );
+  if( winMutex_isNt<0 ){
+    winMutex_isNt = sqlite3_win32_is_nt();
+  }
+  assert( winMutex_isNt==0 || winMutex_isNt==1 );
+  if( winMutex_isNt && TryEnterCriticalSection(&p->mutex) ){
+#ifdef SQLITE_DEBUG
     p->owner = tid;
     p->nRef++;
+#endif
     rc = SQLITE_OK;
   }
 #else
   UNUSED_PARAMETER(p);
 #endif
 #ifdef SQLITE_DEBUG
-  if( rc==SQLITE_OK && p->trace ){
-    printf("try mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  if( p->trace ){
+    OSTRACE(("TRY-MUTEX tid=%lu, mutex=%p (%d), owner=%lu, nRef=%d, rc=%s\n",
+             tid, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc)));
   }
 #endif
   return rc;
@@ -18133,18 +23785,23 @@ static int winMutexTry(sqlite3_mutex *p){
 ** is not currently allocated.  SQLite will never do either.
 */
 static void winMutexLeave(sqlite3_mutex *p){
-#ifndef NDEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   DWORD tid = GetCurrentThreadId();
+#endif
+  assert( p );
+#ifdef SQLITE_DEBUG
   assert( p->nRef>0 );
   assert( p->owner==tid );
   p->nRef--;
   if( p->nRef==0 ) p->owner = 0;
   assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
 #endif
+  assert( winMutex_isInit==1 );
   LeaveCriticalSection(&p->mutex);
 #ifdef SQLITE_DEBUG
   if( p->trace ){
-    printf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+    OSTRACE(("LEAVE-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n",
+             tid, p, p->trace, p->nRef));
   }
 #endif
 }
@@ -18166,9 +23823,9 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
     0
 #endif
   };
-
   return &sMutex;
 }
+
 #endif /* SQLITE_MUTEX_W32 */
 
 /************** End of mutex_w32.c *******************************************/
@@ -18187,6 +23844,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 **
 ** Memory allocation functions used throughout sqlite.
 */
+/* #include "sqliteInt.h" */
 /* #include <stdarg.h> */
 
 /*
@@ -18194,7 +23852,7 @@ SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
 ** held by SQLite. An example of non-essential memory is memory used to
 ** cache database pages that are not currently in use.
 */
-SQLITE_API int sqlite3_release_memory(int n){
+SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int n){
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
   return sqlite3PcacheReleaseMemory(n);
 #else
@@ -18219,16 +23877,7 @@ typedef struct ScratchFreeslot {
 */
 static SQLITE_WSD struct Mem0Global {
   sqlite3_mutex *mutex;         /* Mutex to serialize access */
-
-  /*
-  ** The alarm callback and its arguments.  The mem0.mutex lock will
-  ** be held while the callback is running.  Recursive calls into
-  ** the memory subsystem are allowed, but no new callbacks will be
-  ** issued.
-  */
-  sqlite3_int64 alarmThreshold;
-  void (*alarmCallback)(void*, sqlite3_int64,int);
-  void *alarmArg;
+  sqlite3_int64 alarmThreshold; /* The soft heap limit */
 
   /*
   ** Pointers to the end of sqlite3GlobalConfig.pScratch memory
@@ -18245,54 +23894,32 @@ static SQLITE_WSD struct Mem0Global {
   ** sqlite3_soft_heap_limit() setting.
   */
   int nearlyFull;
-} mem0 = { 0, 0, 0, 0, 0, 0, 0, 0 };
+} mem0 = { 0, 0, 0, 0, 0, 0 };
 
 #define mem0 GLOBAL(struct Mem0Global, mem0)
 
 /*
-** This routine runs when the memory allocator sees that the
-** total memory allocation is about to exceed the soft heap
-** limit.
-*/
-static void softHeapLimitEnforcer(
-  void *NotUsed, 
-  sqlite3_int64 NotUsed2,
-  int allocSize
-){
-  UNUSED_PARAMETER2(NotUsed, NotUsed2);
-  sqlite3_release_memory(allocSize);
-}
-
-/*
-** Change the alarm callback
+** Return the memory allocator mutex. sqlite3_status() needs it.
 */
-static int sqlite3MemoryAlarm(
-  void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
-  void *pArg,
-  sqlite3_int64 iThreshold
-){
-  int nUsed;
-  sqlite3_mutex_enter(mem0.mutex);
-  mem0.alarmCallback = xCallback;
-  mem0.alarmArg = pArg;
-  mem0.alarmThreshold = iThreshold;
-  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
-  mem0.nearlyFull = (iThreshold>0 && iThreshold<=nUsed);
-  sqlite3_mutex_leave(mem0.mutex);
-  return SQLITE_OK;
+SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void){
+  return mem0.mutex;
 }
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
-** Deprecated external interface.  Internal/core SQLite code
-** should call sqlite3MemoryAlarm.
+** Deprecated external interface.  It used to set an alarm callback
+** that was invoked when memory usage grew too large.  Now it is a
+** no-op.
 */
-SQLITE_API int sqlite3_memory_alarm(
+SQLITE_API int SQLITE_STDCALL sqlite3_memory_alarm(
   void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
   void *pArg,
   sqlite3_int64 iThreshold
 ){
-  return sqlite3MemoryAlarm(xCallback, pArg, iThreshold);
+  (void)xCallback;
+  (void)pArg;
+  (void)iThreshold;
+  return SQLITE_OK;
 }
 #endif
 
@@ -18300,26 +23927,29 @@ SQLITE_API int sqlite3_memory_alarm(
 ** Set the soft heap-size limit for the library. Passing a zero or 
 ** negative value indicates no limit.
 */
-SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 n){
   sqlite3_int64 priorLimit;
   sqlite3_int64 excess;
+  sqlite3_int64 nUsed;
 #ifndef SQLITE_OMIT_AUTOINIT
-  sqlite3_initialize();
+  int rc = sqlite3_initialize();
+  if( rc ) return -1;
 #endif
   sqlite3_mutex_enter(mem0.mutex);
   priorLimit = mem0.alarmThreshold;
-  sqlite3_mutex_leave(mem0.mutex);
-  if( n<0 ) return priorLimit;
-  if( n>0 ){
-    sqlite3MemoryAlarm(softHeapLimitEnforcer, 0, n);
-  }else{
-    sqlite3MemoryAlarm(0, 0, 0);
+  if( n<0 ){
+    sqlite3_mutex_leave(mem0.mutex);
+    return priorLimit;
   }
+  mem0.alarmThreshold = n;
+  nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+  mem0.nearlyFull = (n>0 && n<=nUsed);
+  sqlite3_mutex_leave(mem0.mutex);
   excess = sqlite3_memory_used() - n;
   if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff));
   return priorLimit;
 }
-SQLITE_API void sqlite3_soft_heap_limit(int n){
+SQLITE_API void SQLITE_STDCALL sqlite3_soft_heap_limit(int n){
   if( n<0 ) n = 0;
   sqlite3_soft_heap_limit64(n);
 }
@@ -18328,13 +23958,12 @@ SQLITE_API void sqlite3_soft_heap_limit(int n){
 ** Initialize the memory allocation subsystem.
 */
 SQLITE_PRIVATE int sqlite3MallocInit(void){
+  int rc;
   if( sqlite3GlobalConfig.m.xMalloc==0 ){
     sqlite3MemSetDefault();
   }
   memset(&mem0, 0, sizeof(mem0));
-  if( sqlite3GlobalConfig.bCoreMutex ){
-    mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
-  }
+  mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
   if( sqlite3GlobalConfig.pScratch && sqlite3GlobalConfig.szScratch>=100
       && sqlite3GlobalConfig.nScratch>0 ){
     int i, n, sz;
@@ -18358,12 +23987,13 @@ SQLITE_PRIVATE int sqlite3MallocInit(void){
     sqlite3GlobalConfig.nScratch = 0;
   }
   if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512
-      || sqlite3GlobalConfig.nPage<1 ){
+      || sqlite3GlobalConfig.nPage<=0 ){
     sqlite3GlobalConfig.pPage = 0;
     sqlite3GlobalConfig.szPage = 0;
-    sqlite3GlobalConfig.nPage = 0;
   }
-  return sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);
+  rc = sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);
+  if( rc!=SQLITE_OK ) memset(&mem0, 0, sizeof(mem0));
+  return rc;
 }
 
 /*
@@ -18388,11 +24018,9 @@ SQLITE_PRIVATE void sqlite3MallocEnd(void){
 /*
 ** Return the amount of memory currently checked out.
 */
-SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
-  int n, mx;
-  sqlite3_int64 res;
-  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, 0);
-  res = (sqlite3_int64)n;  /* Work around bug in Borland C. Ticket #3216 */
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void){
+  sqlite3_int64 res, mx;
+  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, 0);
   return res;
 }
 
@@ -18401,31 +24029,20 @@ SQLITE_API sqlite3_int64 sqlite3_memory_used(void){
 ** checked out since either the beginning of this process
 ** or since the most recent reset.
 */
-SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){
-  int n, mx;
-  sqlite3_int64 res;
-  sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, resetFlag);
-  res = (sqlite3_int64)mx;  /* Work around bug in Borland C. Ticket #3216 */
-  return res;
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag){
+  sqlite3_int64 res, mx;
+  sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag);
+  return mx;
 }
 
 /*
 ** Trigger the alarm 
 */
 static void sqlite3MallocAlarm(int nByte){
-  void (*xCallback)(void*,sqlite3_int64,int);
-  sqlite3_int64 nowUsed;
-  void *pArg;
-  if( mem0.alarmCallback==0 ) return;
-  xCallback = mem0.alarmCallback;
-  nowUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
-  pArg = mem0.alarmArg;
-  mem0.alarmCallback = 0;
+  if( mem0.alarmThreshold<=0 ) return;
   sqlite3_mutex_leave(mem0.mutex);
-  xCallback(pArg, nowUsed, nByte);
+  sqlite3_release_memory(nByte);
   sqlite3_mutex_enter(mem0.mutex);
-  mem0.alarmCallback = xCallback;
-  mem0.alarmArg = pArg;
 }
 
 /*
@@ -18437,9 +24054,9 @@ static int mallocWithAlarm(int n, void **pp){
   void *p;
   assert( sqlite3_mutex_held(mem0.mutex) );
   nFull = sqlite3GlobalConfig.m.xRoundup(n);
-  sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
-  if( mem0.alarmCallback!=0 ){
-    int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+  sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n);
+  if( mem0.alarmThreshold>0 ){
+    sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
     if( nUsed >= mem0.alarmThreshold - nFull ){
       mem0.nearlyFull = 1;
       sqlite3MallocAlarm(nFull);
@@ -18449,15 +24066,15 @@ static int mallocWithAlarm(int n, void **pp){
   }
   p = sqlite3GlobalConfig.m.xMalloc(nFull);
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
-  if( p==0 && mem0.alarmCallback ){
+  if( p==0 && mem0.alarmThreshold>0 ){
     sqlite3MallocAlarm(nFull);
     p = sqlite3GlobalConfig.m.xMalloc(nFull);
   }
 #endif
   if( p ){
     nFull = sqlite3MallocSize(p);
-    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull);
-    sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, 1);
+    sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);
+    sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);
   }
   *pp = p;
   return nFull;
@@ -18467,11 +24084,9 @@ static int mallocWithAlarm(int n, void **pp){
 ** Allocate memory.  This routine is like sqlite3_malloc() except that it
 ** assumes the memory subsystem has already been initialized.
 */
-SQLITE_PRIVATE void *sqlite3Malloc(int n){
+SQLITE_PRIVATE void *sqlite3Malloc(u64 n){
   void *p;
-  if( n<=0               /* IMP: R-65312-04917 */ 
-   || n>=0x7fffff00
-  ){
+  if( n==0 || n>=0x7fffff00 ){
     /* A memory allocation of a number of bytes which is near the maximum
     ** signed integer value might cause an integer overflow inside of the
     ** xMalloc().  Hence we limit the maximum size to 0x7fffff00, giving
@@ -18480,12 +24095,12 @@ SQLITE_PRIVATE void *sqlite3Malloc(int n){
     p = 0;
   }else if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
-    mallocWithAlarm(n, &p);
+    mallocWithAlarm((int)n, &p);
     sqlite3_mutex_leave(mem0.mutex);
   }else{
-    p = sqlite3GlobalConfig.m.xMalloc(n);
+    p = sqlite3GlobalConfig.m.xMalloc((int)n);
   }
-  assert( EIGHT_BYTE_ALIGNMENT(p) );  /* IMP: R-04675-44850 */
+  assert( EIGHT_BYTE_ALIGNMENT(p) );  /* IMP: R-11148-40995 */
   return p;
 }
 
@@ -18494,7 +24109,13 @@ SQLITE_PRIVATE void *sqlite3Malloc(int n){
 ** First make sure the memory subsystem is initialized, then do the
 ** allocation.
 */
-SQLITE_API void *sqlite3_malloc(int n){
+SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int n){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return n<=0 ? 0 : sqlite3Malloc(n);
+}
+SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64 n){
 #ifndef SQLITE_OMIT_AUTOINIT
   if( sqlite3_initialize() ) return 0;
 #endif
@@ -18525,22 +24146,20 @@ SQLITE_PRIVATE void *sqlite3ScratchMalloc(int n){
   assert( n>0 );
 
   sqlite3_mutex_enter(mem0.mutex);
+  sqlite3StatusHighwater(SQLITE_STATUS_SCRATCH_SIZE, n);
   if( mem0.nScratchFree && sqlite3GlobalConfig.szScratch>=n ){
     p = mem0.pScratchFree;
     mem0.pScratchFree = mem0.pScratchFree->pNext;
     mem0.nScratchFree--;
-    sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
-    sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+    sqlite3StatusUp(SQLITE_STATUS_SCRATCH_USED, 1);
     sqlite3_mutex_leave(mem0.mutex);
   }else{
-    if( sqlite3GlobalConfig.bMemstat ){
-      sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
-      n = mallocWithAlarm(n, &p);
-      if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n);
-      sqlite3_mutex_leave(mem0.mutex);
-    }else{
+    sqlite3_mutex_leave(mem0.mutex);
+    p = sqlite3Malloc(n);
+    if( sqlite3GlobalConfig.bMemstat && p ){
+      sqlite3_mutex_enter(mem0.mutex);
+      sqlite3StatusUp(SQLITE_STATUS_SCRATCH_OVERFLOW, sqlite3MallocSize(p));
       sqlite3_mutex_leave(mem0.mutex);
-      p = sqlite3GlobalConfig.m.xMalloc(n);
     }
     sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH);
   }
@@ -18548,11 +24167,12 @@ SQLITE_PRIVATE void *sqlite3ScratchMalloc(int n){
 
 
 #if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
-  /* Verify that no more than two scratch allocations per thread
-  ** are outstanding at one time.  (This is only checked in the
-  ** single-threaded case since checking in the multi-threaded case
-  ** would be much more complicated.) */
-  assert( scratchAllocOut<=1 );
+  /* EVIDENCE-OF: R-12970-05880 SQLite will not use more than one scratch
+  ** buffers per thread.
+  **
+  ** This can only be checked in single-threaded mode.
+  */
+  assert( scratchAllocOut==0 );
   if( p ) scratchAllocOut++;
 #endif
 
@@ -18570,7 +24190,7 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void *p){
     scratchAllocOut--;
 #endif
 
-    if( p>=sqlite3GlobalConfig.pScratch && p<mem0.pScratchEnd ){
+    if( SQLITE_WITHIN(p, sqlite3GlobalConfig.pScratch, mem0.pScratchEnd) ){
       /* Release memory from the SQLITE_CONFIG_SCRATCH allocation */
       ScratchFreeslot *pSlot;
       pSlot = (ScratchFreeslot*)p;
@@ -18579,19 +24199,19 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void *p){
       mem0.pScratchFree = pSlot;
       mem0.nScratchFree++;
       assert( mem0.nScratchFree <= (u32)sqlite3GlobalConfig.nScratch );
-      sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1);
+      sqlite3StatusDown(SQLITE_STATUS_SCRATCH_USED, 1);
       sqlite3_mutex_leave(mem0.mutex);
     }else{
       /* Release memory back to the heap */
       assert( sqlite3MemdebugHasType(p, MEMTYPE_SCRATCH) );
-      assert( sqlite3MemdebugNoType(p, ~MEMTYPE_SCRATCH) );
+      assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_SCRATCH) );
       sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
       if( sqlite3GlobalConfig.bMemstat ){
         int iSize = sqlite3MallocSize(p);
         sqlite3_mutex_enter(mem0.mutex);
-        sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, -iSize);
-        sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize);
-        sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, -1);
+        sqlite3StatusDown(SQLITE_STATUS_SCRATCH_OVERFLOW, iSize);
+        sqlite3StatusDown(SQLITE_STATUS_MEMORY_USED, iSize);
+        sqlite3StatusDown(SQLITE_STATUS_MALLOC_COUNT, 1);
         sqlite3GlobalConfig.m.xFree(p);
         sqlite3_mutex_leave(mem0.mutex);
       }else{
@@ -18606,7 +24226,7 @@ SQLITE_PRIVATE void sqlite3ScratchFree(void *p){
 */
 #ifndef SQLITE_OMIT_LOOKASIDE
 static int isLookaside(sqlite3 *db, void *p){
-  return p && p>=db->lookaside.pStart && p<db->lookaside.pEnd;
+  return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pEnd);
 }
 #else
 #define isLookaside(A,B) 0
@@ -18618,32 +24238,43 @@ static int isLookaside(sqlite3 *db, void *p){
 */
 SQLITE_PRIVATE int sqlite3MallocSize(void *p){
   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
-  assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );
   return sqlite3GlobalConfig.m.xSize(p);
 }
 SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3 *db, void *p){
-  assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  if( db && isLookaside(db, p) ){
-    return db->lookaside.sz;
-  }else{
-    assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
-    assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) );
-    assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
+  assert( p!=0 );
+  if( db==0 || !isLookaside(db,p) ){
+#if SQLITE_DEBUG
+    if( db==0 ){
+      assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
+      assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
+    }else{
+      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+    }
+#endif
     return sqlite3GlobalConfig.m.xSize(p);
+  }else{
+    assert( sqlite3_mutex_held(db->mutex) );
+    return db->lookaside.sz;
   }
 }
+SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void *p){
+  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
+  return p ? sqlite3GlobalConfig.m.xSize(p) : 0;
+}
 
 /*
 ** Free memory previously obtained from sqlite3Malloc().
 */
-SQLITE_API void sqlite3_free(void *p){
+SQLITE_API void SQLITE_STDCALL sqlite3_free(void *p){
   if( p==0 ) return;  /* IMP: R-49053-54554 */
-  assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );
   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
   if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
-    sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -sqlite3MallocSize(p));
-    sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, -1);
+    sqlite3StatusDown(SQLITE_STATUS_MEMORY_USED, sqlite3MallocSize(p));
+    sqlite3StatusDown(SQLITE_STATUS_MALLOC_COUNT, 1);
     sqlite3GlobalConfig.m.xFree(p);
     sqlite3_mutex_leave(mem0.mutex);
   }else{
@@ -18652,26 +24283,39 @@ SQLITE_API void sqlite3_free(void *p){
 }
 
 /*
+** Add the size of memory allocation "p" to the count in
+** *db->pnBytesFreed.
+*/
+static SQLITE_NOINLINE void measureAllocationSize(sqlite3 *db, void *p){
+  *db->pnBytesFreed += sqlite3DbMallocSize(db,p);
+}
+
+/*
 ** Free memory that might be associated with a particular database
 ** connection.
 */
 SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
   assert( db==0 || sqlite3_mutex_held(db->mutex) );
+  if( p==0 ) return;
   if( db ){
     if( db->pnBytesFreed ){
-      *db->pnBytesFreed += sqlite3DbMallocSize(db, p);
+      measureAllocationSize(db, p);
       return;
     }
     if( isLookaside(db, p) ){
       LookasideSlot *pBuf = (LookasideSlot*)p;
+#if SQLITE_DEBUG
+      /* Trash all content in the buffer being freed */
+      memset(p, 0xaa, db->lookaside.sz);
+#endif
       pBuf->pNext = db->lookaside.pFree;
       db->lookaside.pFree = pBuf;
       db->lookaside.nOut--;
       return;
     }
   }
-  assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
-  assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+  assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
   assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
   sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
   sqlite3_free(p);
@@ -18680,14 +24324,16 @@ SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){
 /*
 ** Change the size of an existing memory allocation
 */
-SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, int nBytes){
+SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, u64 nBytes){
   int nOld, nNew, nDiff;
   void *pNew;
+  assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) );
+  assert( sqlite3MemdebugNoType(pOld, (u8)~MEMTYPE_HEAP) );
   if( pOld==0 ){
-    return sqlite3Malloc(nBytes); /* IMP: R-28354-25769 */
+    return sqlite3Malloc(nBytes); /* IMP: R-04300-56712 */
   }
-  if( nBytes<=0 ){
-    sqlite3_free(pOld); /* IMP: R-31593-10574 */
+  if( nBytes==0 ){
+    sqlite3_free(pOld); /* IMP: R-26507-47431 */
     return 0;
   }
   if( nBytes>=0x7fffff00 ){
@@ -18698,33 +24344,31 @@ SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, int nBytes){
   /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second
   ** argument to xRealloc is always a value returned by a prior call to
   ** xRoundup. */
-  nNew = sqlite3GlobalConfig.m.xRoundup(nBytes);
+  nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);
   if( nOld==nNew ){
     pNew = pOld;
   }else if( sqlite3GlobalConfig.bMemstat ){
     sqlite3_mutex_enter(mem0.mutex);
-    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, nBytes);
+    sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
     nDiff = nNew - nOld;
     if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
           mem0.alarmThreshold-nDiff ){
       sqlite3MallocAlarm(nDiff);
     }
-    assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) );
-    assert( sqlite3MemdebugNoType(pOld, ~MEMTYPE_HEAP) );
     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
-    if( pNew==0 && mem0.alarmCallback ){
-      sqlite3MallocAlarm(nBytes);
+    if( pNew==0 && mem0.alarmThreshold>0 ){
+      sqlite3MallocAlarm((int)nBytes);
       pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
     }
     if( pNew ){
       nNew = sqlite3MallocSize(pNew);
-      sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
+      sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
     }
     sqlite3_mutex_leave(mem0.mutex);
   }else{
     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
   }
-  assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-04675-44850 */
+  assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-11148-40995 */
   return pNew;
 }
 
@@ -18732,7 +24376,14 @@ SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, int nBytes){
 ** The public interface to sqlite3Realloc.  Make sure that the memory
 ** subsystem is initialized prior to invoking sqliteRealloc.
 */
-SQLITE_API void *sqlite3_realloc(void *pOld, int n){
+SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void *pOld, int n){
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  if( n<0 ) n = 0;  /* IMP: R-26507-47431 */
+  return sqlite3Realloc(pOld, n);
+}
+SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void *pOld, sqlite3_uint64 n){
 #ifndef SQLITE_OMIT_AUTOINIT
   if( sqlite3_initialize() ) return 0;
 #endif
@@ -18743,10 +24394,10 @@ SQLITE_API void *sqlite3_realloc(void *pOld, int n){
 /*
 ** Allocate and zero memory.
 */ 
-SQLITE_PRIVATE void *sqlite3MallocZero(int n){
+SQLITE_PRIVATE void *sqlite3MallocZero(u64 n){
   void *p = sqlite3Malloc(n);
   if( p ){
-    memset(p, 0, n);
+    memset(p, 0, (size_t)n);
   }
   return p;
 }
@@ -18755,17 +24406,32 @@ SQLITE_PRIVATE void *sqlite3MallocZero(int n){
 ** Allocate and zero memory.  If the allocation fails, make
 ** the mallocFailed flag in the connection pointer.
 */
-SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, int n){
-  void *p = sqlite3DbMallocRaw(db, n);
-  if( p ){
-    memset(p, 0, n);
-  }
+SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, u64 n){
+  void *p;
+  testcase( db==0 );
+  p = sqlite3DbMallocRaw(db, n);
+  if( p ) memset(p, 0, (size_t)n);
+  return p;
+}
+
+
+/* Finish the work of sqlite3DbMallocRawNN for the unusual and
+** slower case when the allocation cannot be fulfilled using lookaside.
+*/
+static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){
+  void *p;
+  assert( db!=0 );
+  p = sqlite3Malloc(n);
+  if( !p ) sqlite3OomFault(db);
+  sqlite3MemdebugSetType(p, 
+         (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
   return p;
 }
 
 /*
-** Allocate and zero memory.  If the allocation fails, make
-** the mallocFailed flag in the connection pointer.
+** Allocate memory, either lookaside (if possible) or heap.  
+** If the allocation fails, set the mallocFailed flag in
+** the connection pointer.
 **
 ** If db!=0 and db->mallocFailed is true (indicating a prior malloc
 ** failure on the same database connection) then always return 0.
@@ -18780,79 +24446,87 @@ SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, int n){
 **
 ** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
 ** that all prior mallocs (ex: "a") worked too.
+**
+** The sqlite3MallocRawNN() variant guarantees that the "db" parameter is
+** not a NULL pointer.
 */
-SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, int n){
+SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){
   void *p;
-  assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  assert( db==0 || db->pnBytesFreed==0 );
+  if( db ) return sqlite3DbMallocRawNN(db, n);
+  p = sqlite3Malloc(n);
+  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
+  return p;
+}
+SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
 #ifndef SQLITE_OMIT_LOOKASIDE
-  if( db ){
-    LookasideSlot *pBuf;
-    if( db->mallocFailed ){
-      return 0;
-    }
-    if( db->lookaside.bEnabled ){
-      if( n>db->lookaside.sz ){
-        db->lookaside.anStat[1]++;
-      }else if( (pBuf = db->lookaside.pFree)==0 ){
-        db->lookaside.anStat[2]++;
-      }else{
-        db->lookaside.pFree = pBuf->pNext;
-        db->lookaside.nOut++;
-        db->lookaside.anStat[0]++;
-        if( db->lookaside.nOut>db->lookaside.mxOut ){
-          db->lookaside.mxOut = db->lookaside.nOut;
-        }
-        return (void*)pBuf;
+  LookasideSlot *pBuf;
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->lookaside.bDisable==0 ){
+    assert( db->mallocFailed==0 );
+    if( n>db->lookaside.sz ){
+      db->lookaside.anStat[1]++;
+    }else if( (pBuf = db->lookaside.pFree)==0 ){
+      db->lookaside.anStat[2]++;
+    }else{
+      db->lookaside.pFree = pBuf->pNext;
+      db->lookaside.nOut++;
+      db->lookaside.anStat[0]++;
+      if( db->lookaside.nOut>db->lookaside.mxOut ){
+        db->lookaside.mxOut = db->lookaside.nOut;
       }
+      return (void*)pBuf;
     }
+  }else if( db->mallocFailed ){
+    return 0;
   }
 #else
-  if( db && db->mallocFailed ){
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( db->pnBytesFreed==0 );
+  if( db->mallocFailed ){
     return 0;
   }
 #endif
-  p = sqlite3Malloc(n);
-  if( !p && db ){
-    db->mallocFailed = 1;
-  }
-  sqlite3MemdebugSetType(p, MEMTYPE_DB |
-         ((db && db->lookaside.bEnabled) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
-  return p;
+  return dbMallocRawFinish(db, n);
 }
 
+/* Forward declaration */
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n);
+
 /*
 ** Resize the block of memory pointed to by p to n bytes. If the
 ** resize fails, set the mallocFailed flag in the connection object.
 */
-SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, int n){
-  void *pNew = 0;
+SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
   assert( db!=0 );
+  if( p==0 ) return sqlite3DbMallocRawNN(db, n);
   assert( sqlite3_mutex_held(db->mutex) );
+  if( isLookaside(db,p) && n<=db->lookaside.sz ) return p;
+  return dbReallocFinish(db, p, n);
+}
+static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
+  void *pNew = 0;
+  assert( db!=0 );
+  assert( p!=0 );
   if( db->mallocFailed==0 ){
-    if( p==0 ){
-      return sqlite3DbMallocRaw(db, n);
-    }
     if( isLookaside(db, p) ){
-      if( n<=db->lookaside.sz ){
-        return p;
-      }
-      pNew = sqlite3DbMallocRaw(db, n);
+      pNew = sqlite3DbMallocRawNN(db, n);
       if( pNew ){
         memcpy(pNew, p, db->lookaside.sz);
         sqlite3DbFree(db, p);
       }
     }else{
-      assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
-      assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) );
+      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
+      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
       sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
-      pNew = sqlite3_realloc(p, n);
+      pNew = sqlite3_realloc64(p, n);
       if( !pNew ){
-        sqlite3MemdebugSetType(p, MEMTYPE_DB|MEMTYPE_HEAP);
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
-      sqlite3MemdebugSetType(pNew, MEMTYPE_DB | 
-            (db->lookaside.bEnabled ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
+      sqlite3MemdebugSetType(pNew,
+            (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
     }
   }
   return pNew;
@@ -18862,7 +24536,7 @@ SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, int n){
 ** Attempt to reallocate p.  If the reallocation fails, then free p
 ** and set the mallocFailed flag in the database connection.
 */
-SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, int n){
+SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, u64 n){
   void *pNew;
   pNew = sqlite3DbRealloc(db, p, n);
   if( !pNew ){
@@ -18892,36 +24566,69 @@ SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3 *db, const char *z){
   }
   return zNew;
 }
-SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, int n){
+SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
   char *zNew;
+  assert( db!=0 );
   if( z==0 ){
     return 0;
   }
   assert( (n&0x7fffffff)==n );
-  zNew = sqlite3DbMallocRaw(db, n+1);
+  zNew = sqlite3DbMallocRawNN(db, n+1);
   if( zNew ){
-    memcpy(zNew, z, n);
+    memcpy(zNew, z, (size_t)n);
     zNew[n] = 0;
   }
   return zNew;
 }
 
 /*
-** Create a string from the zFromat argument and the va_list that follows.
-** Store the string in memory obtained from sqliteMalloc() and make *pz
-** point to that string.
+** Free any prior content in *pz and replace it with a copy of zNew.
 */
-SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zFormat, ...){
-  va_list ap;
-  char *z;
-
-  va_start(ap, zFormat);
-  z = sqlite3VMPrintf(db, zFormat, ap);
-  va_end(ap);
+SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
   sqlite3DbFree(db, *pz);
-  *pz = z;
+  *pz = sqlite3DbStrDup(db, zNew);
 }
 
+/*
+** Call this routine to record the fact that an OOM (out-of-memory) error
+** has happened.  This routine will set db->mallocFailed, and also
+** temporarily disable the lookaside memory allocator and interrupt
+** any running VDBEs.
+*/
+SQLITE_PRIVATE void sqlite3OomFault(sqlite3 *db){
+  if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
+    db->mallocFailed = 1;
+    if( db->nVdbeExec>0 ){
+      db->u1.isInterrupted = 1;
+    }
+    db->lookaside.bDisable++;
+  }
+}
+
+/*
+** This routine reactivates the memory allocator and clears the
+** db->mallocFailed flag as necessary.
+**
+** The memory allocator is not restarted if there are running
+** VDBEs.
+*/
+SQLITE_PRIVATE void sqlite3OomClear(sqlite3 *db){
+  if( db->mallocFailed && db->nVdbeExec==0 ){
+    db->mallocFailed = 0;
+    db->u1.isInterrupted = 0;
+    assert( db->lookaside.bDisable>0 );
+    db->lookaside.bDisable--;
+  }
+}
+
+/*
+** Take actions at the end of an API call to indicate an OOM error
+*/
+static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
+  sqlite3OomClear(db);
+  sqlite3Error(db, SQLITE_NOMEM);
+  return SQLITE_NOMEM_BKPT;
+}
 
 /*
 ** This function must be called before exiting any API function (i.e. 
@@ -18932,65 +24639,61 @@ SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zFormat
 ** function. However, if a malloc() failure has occurred since the previous
 ** invocation SQLITE_NOMEM is returned instead. 
 **
-** If the first argument, db, is not NULL and a malloc() error has occurred,
-** then the connection error-code (the value returned by sqlite3_errcode())
-** is set to SQLITE_NOMEM.
+** If an OOM as occurred, then the connection error-code (the value
+** returned by sqlite3_errcode()) is set to SQLITE_NOMEM.
 */
 SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){
-  /* If the db handle is not NULL, then we must hold the connection handle
-  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
+  /* If the db handle must hold the connection handle mutex here.
+  ** Otherwise the read (and possible write) of db->mallocFailed 
   ** is unsafe, as is the call to sqlite3Error().
   */
-  assert( !db || sqlite3_mutex_held(db->mutex) );
-  if( db && (db->mallocFailed || rc==SQLITE_IOERR_NOMEM) ){
-    sqlite3Error(db, SQLITE_NOMEM, 0);
-    db->mallocFailed = 0;
-    rc = SQLITE_NOMEM;
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
+    return apiOomError(db);
   }
-  return rc & (db ? db->errMask : 0xff);
+  return rc & db->errMask;
 }
 
 /************** End of malloc.c **********************************************/
 /************** Begin file printf.c ******************************************/
 /*
 ** The "printf" code that follows dates from the 1980's.  It is in
-** the public domain.  The original comments are included here for
-** completeness.  They are very out-of-date but might be useful as
-** an historical reference.  Most of the "enhancements" have been backed
-** out so that the functionality is now the same as standard printf().
+** the public domain. 
 **
 **************************************************************************
 **
 ** This file contains code for a set of "printf"-like routines.  These
 ** routines format strings much like the printf() from the standard C
 ** library, though the implementation here has enhancements to support
-** SQLlite.
+** SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Conversion types fall into various categories as defined by the
 ** following enumeration.
 */
-#define etRADIX       1 /* Integer types.  %d, %x, %o, and so forth */
-#define etFLOAT       2 /* Floating point.  %f */
-#define etEXP         3 /* Exponentional notation. %e and %E */
-#define etGENERIC     4 /* Floating or exponential, depending on exponent. %g */
-#define etSIZE        5 /* Return number of characters processed so far. %n */
-#define etSTRING      6 /* Strings. %s */
-#define etDYNSTRING   7 /* Dynamically allocated strings. %z */
-#define etPERCENT     8 /* Percent symbol. %% */
-#define etCHARX       9 /* Characters. %c */
+#define etRADIX       0 /* Integer types.  %d, %x, %o, and so forth */
+#define etFLOAT       1 /* Floating point.  %f */
+#define etEXP         2 /* Exponentional notation. %e and %E */
+#define etGENERIC     3 /* Floating or exponential, depending on exponent. %g */
+#define etSIZE        4 /* Return number of characters processed so far. %n */
+#define etSTRING      5 /* Strings. %s */
+#define etDYNSTRING   6 /* Dynamically allocated strings. %z */
+#define etPERCENT     7 /* Percent symbol. %% */
+#define etCHARX       8 /* Characters. %c */
 /* The rest are extensions, not normally found in printf() */
-#define etSQLESCAPE  10 /* Strings with '\'' doubled.  %q */
-#define etSQLESCAPE2 11 /* Strings with '\'' doubled and enclosed in '',
+#define etSQLESCAPE   9 /* Strings with '\'' doubled.  %q */
+#define etSQLESCAPE2 10 /* Strings with '\'' doubled and enclosed in '',
                           NULL pointers replaced by SQL NULL.  %Q */
-#define etTOKEN      12 /* a pointer to a Token structure */
-#define etSRCLIST    13 /* a pointer to a SrcList */
-#define etPOINTER    14 /* The %p conversion */
-#define etSQLESCAPE3 15 /* %w -> Strings with '\"' doubled */
-#define etORDINAL    16 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
+#define etTOKEN      11 /* a pointer to a Token structure */
+#define etSRCLIST    12 /* a pointer to a SrcList */
+#define etPOINTER    13 /* The %p conversion */
+#define etSQLESCAPE3 14 /* %w -> Strings with '\"' doubled */
+#define etORDINAL    15 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */
 
-#define etINVALID     0 /* Any unrecognized conversion type */
+#define etINVALID    16 /* Any unrecognized conversion type */
 
 
 /*
@@ -19077,7 +24780,8 @@ static const et_info fmtinfo[] = {
 static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
   int digit;
   LONGDOUBLE_TYPE d;
-  if( (*cnt)++ >= 16 ) return '0';
+  if( (*cnt)<=0 ) return '0';
+  (*cnt)--;
   digit = (int)*val;
   d = digit;
   digit += '0';
@@ -19087,18 +24791,30 @@ static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){
 #endif /* SQLITE_OMIT_FLOATING_POINT */
 
 /*
-** Append N space characters to the given string buffer.
+** Set the StrAccum object to an error mode.
 */
-static void appendSpace(StrAccum *pAccum, int N){
-  static const char zSpaces[] = "                             ";
-  while( N>=(int)sizeof(zSpaces)-1 ){
-    sqlite3StrAccumAppend(pAccum, zSpaces, sizeof(zSpaces)-1);
-    N -= sizeof(zSpaces)-1;
-  }
-  if( N>0 ){
-    sqlite3StrAccumAppend(pAccum, zSpaces, N);
-  }
+static void setStrAccumError(StrAccum *p, u8 eError){
+  assert( eError==STRACCUM_NOMEM || eError==STRACCUM_TOOBIG );
+  p->accError = eError;
+  p->nAlloc = 0;
+}
+
+/*
+** Extra argument values from a PrintfArguments object
+*/
+static sqlite3_int64 getIntArg(PrintfArguments *p){
+  if( p->nArg<=p->nUsed ) return 0;
+  return sqlite3_value_int64(p->apArg[p->nUsed++]);
 }
+static double getDoubleArg(PrintfArguments *p){
+  if( p->nArg<=p->nUsed ) return 0.0;
+  return sqlite3_value_double(p->apArg[p->nUsed++]);
+}
+static char *getTextArg(PrintfArguments *p){
+  if( p->nArg<=p->nUsed ) return 0;
+  return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
+}
+
 
 /*
 ** On machines with a small stack size, you can redefine the
@@ -19113,10 +24829,9 @@ static void appendSpace(StrAccum *pAccum, int N){
 ** Render a string given by "fmt" into the StrAccum object.
 */
 SQLITE_PRIVATE void sqlite3VXPrintf(
-  StrAccum *pAccum,                  /* Accumulate results here */
-  int useExtended,                   /* Allow extended %-conversions */
-  const char *fmt,                   /* Format string */
-  va_list ap                         /* arguments */
+  StrAccum *pAccum,          /* Accumulate results here */
+  const char *fmt,           /* Format string */
+  va_list ap                 /* arguments */
 ){
   int c;                     /* Next character in the format string */
   char *bufpt;               /* Pointer to the conversion buffer */
@@ -19133,14 +24848,16 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
   etByte flag_long;          /* True if "l" flag is present */
   etByte flag_longlong;      /* True if the "ll" flag is present */
   etByte done;               /* Loop termination flag */
-  etByte xtype = 0;          /* Conversion paradigm */
+  etByte xtype = etINVALID;  /* Conversion paradigm */
+  u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
+  u8 useIntern;              /* Ok to use internal conversions (ex: %T) */
   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
   sqlite_uint64 longvalue;   /* Value for integer types */
   LONGDOUBLE_TYPE realvalue; /* Value for real types */
   const et_info *infop;      /* Pointer to the appropriate info structure */
   char *zOut;                /* Rendering buffer */
   int nOut;                  /* Size of the rendering buffer */
-  char *zExtra;              /* Malloced memory used by some conversion */
+  char *zExtra = 0;          /* Malloced memory used by some conversion */
 #ifndef SQLITE_OMIT_FLOATING_POINT
   int  exp, e2;              /* exponent of real numbers */
   int nsd;                   /* Number of significant digits returned */
@@ -19148,17 +24865,28 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
   etByte flag_dp;            /* True if decimal point should be shown */
   etByte flag_rtz;           /* True if trailing zeros should be removed */
 #endif
+  PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */
   char buf[etBUFSIZE];       /* Conversion buffer */
 
   bufpt = 0;
+  if( pAccum->printfFlags ){
+    if( (bArgList = (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC))!=0 ){
+      pArgList = va_arg(ap, PrintfArguments*);
+    }
+    useIntern = pAccum->printfFlags & SQLITE_PRINTF_INTERNAL;
+  }else{
+    bArgList = useIntern = 0;
+  }
   for(; (c=(*fmt))!=0; ++fmt){
     if( c!='%' ){
-      int amt;
       bufpt = (char *)fmt;
-      amt = 1;
-      while( (c=(*++fmt))!='%' && c!=0 ) amt++;
-      sqlite3StrAccumAppend(pAccum, bufpt, amt);
-      if( c==0 ) break;
+#if HAVE_STRCHRNUL
+      fmt = strchrnul(fmt, '%');
+#else
+      do{ fmt++; }while( *fmt && *fmt != '%' );
+#endif
+      sqlite3StrAccumAppend(pAccum, bufpt, (int)(fmt - bufpt));
+      if( *fmt==0 ) break;
     }
     if( (c=(*++fmt))==0 ){
       sqlite3StrAccumAppend(pAccum, "%", 1);
@@ -19180,37 +24908,66 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       }
     }while( !done && (c=(*++fmt))!=0 );
     /* Get the field width */
-    width = 0;
     if( c=='*' ){
-      width = va_arg(ap,int);
+      if( bArgList ){
+        width = (int)getIntArg(pArgList);
+      }else{
+        width = va_arg(ap,int);
+      }
       if( width<0 ){
         flag_leftjustify = 1;
-        width = -width;
+        width = width >= -2147483647 ? -width : 0;
       }
       c = *++fmt;
     }else{
+      unsigned wx = 0;
       while( c>='0' && c<='9' ){
-        width = width*10 + c - '0';
+        wx = wx*10 + c - '0';
         c = *++fmt;
       }
+      testcase( wx>0x7fffffff );
+      width = wx & 0x7fffffff;
     }
+    assert( width>=0 );
+#ifdef SQLITE_PRINTF_PRECISION_LIMIT
+    if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
+      width = SQLITE_PRINTF_PRECISION_LIMIT;
+    }
+#endif
+
     /* Get the precision */
     if( c=='.' ){
-      precision = 0;
       c = *++fmt;
       if( c=='*' ){
-        precision = va_arg(ap,int);
-        if( precision<0 ) precision = -precision;
+        if( bArgList ){
+          precision = (int)getIntArg(pArgList);
+        }else{
+          precision = va_arg(ap,int);
+        }
         c = *++fmt;
+        if( precision<0 ){
+          precision = precision >= -2147483647 ? -precision : -1;
+        }
       }else{
+        unsigned px = 0;
         while( c>='0' && c<='9' ){
-          precision = precision*10 + c - '0';
+          px = px*10 + c - '0';
           c = *++fmt;
         }
+        testcase( px>0x7fffffff );
+        precision = px & 0x7fffffff;
       }
     }else{
       precision = -1;
     }
+    assert( precision>=(-1) );
+#ifdef SQLITE_PRINTF_PRECISION_LIMIT
+    if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
+      precision = SQLITE_PRINTF_PRECISION_LIMIT;
+    }
+#endif
+
+
     /* Get the conversion type modifier */
     if( c=='l' ){
       flag_long = 1;
@@ -19230,7 +24987,7 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     for(idx=0; idx<ArraySize(fmtinfo); idx++){
       if( c==fmtinfo[idx].fmttype ){
         infop = &fmtinfo[idx];
-        if( useExtended || (infop->flags & FLAG_INTERN)==0 ){
+        if( useIntern || (infop->flags & FLAG_INTERN)==0 ){
           xtype = infop->type;
         }else{
           return;
@@ -19238,7 +24995,6 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         break;
       }
     }
-    zExtra = 0;
 
     /*
     ** At this point, variables are initialized as follows:
@@ -19270,7 +25026,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       case etRADIX:
         if( infop->flags & FLAG_SIGNED ){
           i64 v;
-          if( flag_longlong ){
+          if( bArgList ){
+            v = getIntArg(pArgList);
+          }else if( flag_longlong ){
             v = va_arg(ap,i64);
           }else if( flag_long ){
             v = va_arg(ap,long int);
@@ -19291,7 +25049,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
             else                       prefix = 0;
           }
         }else{
-          if( flag_longlong ){
+          if( bArgList ){
+            longvalue = (u64)getIntArg(pArgList);
+          }else if( flag_longlong ){
             longvalue = va_arg(ap,u64);
           }else if( flag_long ){
             longvalue = va_arg(ap,unsigned long int);
@@ -19311,7 +25071,7 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           nOut = precision + 10;
           zOut = zExtra = sqlite3Malloc( nOut );
           if( zOut==0 ){
-            pAccum->mallocFailed = 1;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }
@@ -19326,10 +25086,8 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           *(--bufpt) = zOrd[x*2];
         }
         {
-          register const char *cset;      /* Use registers for speed */
-          register int base;
-          cset = &aDigits[infop->charset];
-          base = infop->base;
+          const char *cset = &aDigits[infop->charset];
+          u8 base = infop->base;
           do{                                           /* Convert to ascii */
             *(--bufpt) = cset[longvalue%base];
             longvalue = longvalue/base;
@@ -19351,7 +25109,11 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       case etFLOAT:
       case etEXP:
       case etGENERIC:
-        realvalue = va_arg(ap,double);
+        if( bArgList ){
+          realvalue = getDoubleArg(pArgList);
+        }else{
+          realvalue = va_arg(ap,double);
+        }
 #ifdef SQLITE_OMIT_FLOATING_POINT
         length = 0;
 #else
@@ -19365,13 +25127,8 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           else                         prefix = 0;
         }
         if( xtype==etGENERIC && precision>0 ) precision--;
-#if 0
-        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
-        for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
-#else
-        /* It makes more sense to use 0.5 */
-        for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
-#endif
+        testcase( precision>0xfff );
+        for(idx=precision&0xfff, rounder=0.5; idx>0; idx--, rounder*=0.1){}
         if( xtype==etFLOAT ) realvalue += rounder;
         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
         exp = 0;
@@ -19381,20 +25138,18 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           break;
         }
         if( realvalue>0.0 ){
-          while( realvalue>=1e32 && exp<=350 ){ realvalue *= 1e-32; exp+=32; }
-          while( realvalue>=1e8 && exp<=350 ){ realvalue *= 1e-8; exp+=8; }
-          while( realvalue>=10.0 && exp<=350 ){ realvalue *= 0.1; exp++; }
+          LONGDOUBLE_TYPE scale = 1.0;
+          while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}
+          while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }
+          while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
+          realvalue /= scale;
           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
           if( exp>350 ){
-            if( prefix=='-' ){
-              bufpt = "-Inf";
-            }else if( prefix=='+' ){
-              bufpt = "+Inf";
-            }else{
-              bufpt = "Inf";
-            }
-            length = sqlite3Strlen30(bufpt);
+            bufpt = buf;
+            buf[0] = prefix;
+            memcpy(buf+(prefix!=0),"Inf",4);
+            length = 3+(prefix!=0);
             break;
           }
         }
@@ -19416,22 +25171,23 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
             xtype = etFLOAT;
           }
         }else{
-          flag_rtz = 0;
+          flag_rtz = flag_altform2;
         }
         if( xtype==etEXP ){
           e2 = 0;
         }else{
           e2 = exp;
         }
-        if( e2+precision+width > etBUFSIZE - 15 ){
-          bufpt = zExtra = sqlite3Malloc( e2+precision+width+15 );
+        if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
+          bufpt = zExtra 
+              = sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
           if( bufpt==0 ){
-            pAccum->mallocFailed = 1;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }
         zOut = bufpt;
-        nsd = 0;
+        nsd = 16 + flag_altform2*10;
         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
         /* The sign in front of the number */
         if( prefix ){
@@ -19509,7 +25265,9 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
 #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */
         break;
       case etSIZE:
-        *(va_arg(ap,int*)) = pAccum->nChar;
+        if( !bArgList ){
+          *(va_arg(ap,int*)) = pAccum->nChar;
+        }
         length = width = 0;
         break;
       case etPERCENT:
@@ -19518,19 +25276,32 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         length = 1;
         break;
       case etCHARX:
-        c = va_arg(ap,int);
-        buf[0] = (char)c;
-        if( precision>=0 ){
-          for(idx=1; idx<precision; idx++) buf[idx] = (char)c;
-          length = precision;
+        if( bArgList ){
+          bufpt = getTextArg(pArgList);
+          c = bufpt ? bufpt[0] : 0;
         }else{
-          length =1;
+          c = va_arg(ap,int);
         }
+        if( precision>1 ){
+          width -= precision-1;
+          if( width>1 && !flag_leftjustify ){
+            sqlite3AppendChar(pAccum, width-1, ' ');
+            width = 0;
+          }
+          sqlite3AppendChar(pAccum, precision-1, c);
+        }
+        length = 1;
+        buf[0] = c;
         bufpt = buf;
         break;
       case etSTRING:
       case etDYNSTRING:
-        bufpt = va_arg(ap,char*);
+        if( bArgList ){
+          bufpt = getTextArg(pArgList);
+          xtype = etSTRING;
+        }else{
+          bufpt = va_arg(ap,char*);
+        }
         if( bufpt==0 ){
           bufpt = "";
         }else if( xtype==etDYNSTRING ){
@@ -19542,14 +25313,20 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           length = sqlite3Strlen30(bufpt);
         }
         break;
-      case etSQLESCAPE:
-      case etSQLESCAPE2:
-      case etSQLESCAPE3: {
+      case etSQLESCAPE:           /* Escape ' characters */
+      case etSQLESCAPE2:          /* Escape ' and enclose in '...' */
+      case etSQLESCAPE3: {        /* Escape " characters */
         int i, j, k, n, isnull;
         int needQuote;
         char ch;
         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */
-        char *escarg = va_arg(ap,char*);
+        char *escarg;
+
+        if( bArgList ){
+          escarg = getTextArg(pArgList);
+        }else{
+          escarg = va_arg(ap,char*);
+        }
         isnull = escarg==0;
         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");
         k = precision;
@@ -19557,11 +25334,11 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
           if( ch==q )  n++;
         }
         needQuote = !isnull && xtype==etSQLESCAPE2;
-        n += i + 1 + needQuote*2;
+        n += i + 3;
         if( n>etBUFSIZE ){
           bufpt = zExtra = sqlite3Malloc( n );
           if( bufpt==0 ){
-            pAccum->mallocFailed = 1;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }else{
@@ -19584,7 +25361,8 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
       }
       case etTOKEN: {
         Token *pToken = va_arg(ap, Token*);
-        if( pToken ){
+        assert( bArgList==0 );
+        if( pToken && pToken->n ){
           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
         }
         length = width = 0;
@@ -19594,12 +25372,13 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
         SrcList *pSrc = va_arg(ap, SrcList*);
         int k = va_arg(ap, int);
         struct SrcList_item *pItem = &pSrc->a[k];
+        assert( bArgList==0 );
         assert( k>=0 && k<pSrc->nSrc );
         if( pItem->zDatabase ){
-          sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
+          sqlite3StrAccumAppendAll(pAccum, pItem->zDatabase);
           sqlite3StrAccumAppend(pAccum, ".", 1);
         }
-        sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
+        sqlite3StrAccumAppendAll(pAccum, pItem->zName);
         length = width = 0;
         break;
       }
@@ -19613,101 +25392,145 @@ SQLITE_PRIVATE void sqlite3VXPrintf(
     ** "length" characters long.  The field width is "width".  Do
     ** the output.
     */
-    if( !flag_leftjustify ){
-      register int nspace;
-      nspace = width-length;
-      if( nspace>0 ){
-        appendSpace(pAccum, nspace);
-      }
-    }
-    if( length>0 ){
-      sqlite3StrAccumAppend(pAccum, bufpt, length);
-    }
-    if( flag_leftjustify ){
-      register int nspace;
-      nspace = width-length;
-      if( nspace>0 ){
-        appendSpace(pAccum, nspace);
-      }
+    width -= length;
+    if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
+    sqlite3StrAccumAppend(pAccum, bufpt, length);
+    if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
+
+    if( zExtra ){
+      sqlite3DbFree(pAccum->db, zExtra);
+      zExtra = 0;
     }
-    sqlite3_free(zExtra);
   }/* End for loop over the format string */
 } /* End of function */
 
 /*
-** Append N bytes of text from z to the StrAccum object.
+** Enlarge the memory allocation on a StrAccum object so that it is
+** able to accept at least N more bytes of text.
+**
+** Return the number of bytes of text that StrAccum is able to accept
+** after the attempted enlargement.  The value returned might be zero.
 */
-SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
-  assert( z!=0 || N==0 );
-  if( p->tooBig | p->mallocFailed ){
-    testcase(p->tooBig);
-    testcase(p->mallocFailed);
-    return;
+static int sqlite3StrAccumEnlarge(StrAccum *p, int N){
+  char *zNew;
+  assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */
+  if( p->accError ){
+    testcase(p->accError==STRACCUM_TOOBIG);
+    testcase(p->accError==STRACCUM_NOMEM);
+    return 0;
   }
-  assert( p->zText!=0 || p->nChar==0 );
-  if( N<0 ){
-    N = sqlite3Strlen30(z);
+  if( p->mxAlloc==0 ){
+    N = p->nAlloc - p->nChar - 1;
+    setStrAccumError(p, STRACCUM_TOOBIG);
+    return N;
+  }else{
+    char *zOld = isMalloced(p) ? p->zText : 0;
+    i64 szNew = p->nChar;
+    assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
+    szNew += N + 1;
+    if( szNew+p->nChar<=p->mxAlloc ){
+      /* Force exponential buffer size growth as long as it does not overflow,
+      ** to avoid having to call this routine too often */
+      szNew += p->nChar;
+    }
+    if( szNew > p->mxAlloc ){
+      sqlite3StrAccumReset(p);
+      setStrAccumError(p, STRACCUM_TOOBIG);
+      return 0;
+    }else{
+      p->nAlloc = (int)szNew;
+    }
+    if( p->db ){
+      zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
+    }else{
+      zNew = sqlite3_realloc64(zOld, p->nAlloc);
+    }
+    if( zNew ){
+      assert( p->zText!=0 || p->nChar==0 );
+      if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
+      p->zText = zNew;
+      p->nAlloc = sqlite3DbMallocSize(p->db, zNew);
+      p->printfFlags |= SQLITE_PRINTF_MALLOCED;
+    }else{
+      sqlite3StrAccumReset(p);
+      setStrAccumError(p, STRACCUM_NOMEM);
+      return 0;
+    }
   }
-  if( N==0 || NEVER(z==0) ){
+  return N;
+}
+
+/*
+** Append N copies of character c to the given string buffer.
+*/
+SQLITE_PRIVATE void sqlite3AppendChar(StrAccum *p, int N, char c){
+  testcase( p->nChar + (i64)N > 0x7fffffff );
+  if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){
     return;
   }
+  assert( (p->zText==p->zBase)==!isMalloced(p) );
+  while( (N--)>0 ) p->zText[p->nChar++] = c;
+}
+
+/*
+** The StrAccum "p" is not large enough to accept N new bytes of z[].
+** So enlarge if first, then do the append.
+**
+** This is a helper routine to sqlite3StrAccumAppend() that does special-case
+** work (enlarging the buffer) using tail recursion, so that the
+** sqlite3StrAccumAppend() routine can use fast calling semantics.
+*/
+static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){
+  N = sqlite3StrAccumEnlarge(p, N);
+  if( N>0 ){
+    memcpy(&p->zText[p->nChar], z, N);
+    p->nChar += N;
+  }
+  assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
+}
+
+/*
+** Append N bytes of text from z to the StrAccum object.  Increase the
+** size of the memory allocation for StrAccum if necessary.
+*/
+SQLITE_PRIVATE void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
+  assert( z!=0 || N==0 );
+  assert( p->zText!=0 || p->nChar==0 || p->accError );
+  assert( N>=0 );
+  assert( p->accError==0 || p->nAlloc==0 );
   if( p->nChar+N >= p->nAlloc ){
-    char *zNew;
-    if( !p->useMalloc ){
-      p->tooBig = 1;
-      N = p->nAlloc - p->nChar - 1;
-      if( N<=0 ){
-        return;
-      }
-    }else{
-      char *zOld = (p->zText==p->zBase ? 0 : p->zText);
-      i64 szNew = p->nChar;
-      szNew += N + 1;
-      if( szNew > p->mxAlloc ){
-        sqlite3StrAccumReset(p);
-        p->tooBig = 1;
-        return;
-      }else{
-        p->nAlloc = (int)szNew;
-      }
-      if( p->useMalloc==1 ){
-        zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);
-      }else{
-        zNew = sqlite3_realloc(zOld, p->nAlloc);
-      }
-      if( zNew ){
-        if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
-        p->zText = zNew;
-      }else{
-        p->mallocFailed = 1;
-        sqlite3StrAccumReset(p);
-        return;
-      }
-    }
+    enlargeAndAppend(p,z,N);
+  }else{
+    assert( p->zText );
+    p->nChar += N;
+    memcpy(&p->zText[p->nChar-N], z, N);
   }
-  assert( p->zText );
-  memcpy(&p->zText[p->nChar], z, N);
-  p->nChar += N;
 }
 
 /*
+** Append the complete text of zero-terminated string z[] to the p string.
+*/
+SQLITE_PRIVATE void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
+  sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));
+}
+
+
+/*
 ** Finish off a string by making sure it is zero-terminated.
 ** Return a pointer to the resulting string.  Return a NULL
 ** pointer if any kind of error was encountered.
 */
 SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){
   if( p->zText ){
+    assert( (p->zText==p->zBase)==!isMalloced(p) );
     p->zText[p->nChar] = 0;
-    if( p->useMalloc && p->zText==p->zBase ){
-      if( p->useMalloc==1 ){
-        p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
-      }else{
-        p->zText = sqlite3_malloc(p->nChar+1);
-      }
+    if( p->mxAlloc>0 && !isMalloced(p) ){
+      p->zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );
       if( p->zText ){
         memcpy(p->zText, p->zBase, p->nChar+1);
+        p->printfFlags |= SQLITE_PRINTF_MALLOCED;
       }else{
-        p->mallocFailed = 1;
+        setStrAccumError(p, STRACCUM_NOMEM);
       }
     }
   }
@@ -19718,28 +25541,36 @@ SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){
 ** Reset an StrAccum string.  Reclaim all malloced memory.
 */
 SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum *p){
-  if( p->zText!=p->zBase ){
-    if( p->useMalloc==1 ){
-      sqlite3DbFree(p->db, p->zText);
-    }else{
-      sqlite3_free(p->zText);
-    }
+  assert( (p->zText==0 || p->zText==p->zBase)==!isMalloced(p) );
+  if( isMalloced(p) ){
+    sqlite3DbFree(p->db, p->zText);
+    p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;
   }
   p->zText = 0;
 }
 
 /*
-** Initialize a string accumulator
+** Initialize a string accumulator.
+**
+** p:     The accumulator to be initialized.
+** db:    Pointer to a database connection.  May be NULL.  Lookaside
+**        memory is used if not NULL. db->mallocFailed is set appropriately
+**        when not NULL.
+** zBase: An initial buffer.  May be NULL in which case the initial buffer
+**        is malloced.
+** n:     Size of zBase in bytes.  If total space requirements never exceed
+**        n then no memory allocations ever occur.
+** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory
+**        allocations will ever occur.
 */
-SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
+SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){
   p->zText = p->zBase = zBase;
-  p->db = 0;
+  p->db = db;
   p->nChar = 0;
   p->nAlloc = n;
   p->mxAlloc = mx;
-  p->useMalloc = 1;
-  p->tooBig = 0;
-  p->mallocFailed = 0;
+  p->accError = 0;
+  p->printfFlags = 0;
 }
 
 /*
@@ -19751,13 +25582,13 @@ SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list a
   char zBase[SQLITE_PRINT_BUF_SIZE];
   StrAccum acc;
   assert( db!=0 );
-  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase),
+  sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),
                       db->aLimit[SQLITE_LIMIT_LENGTH]);
-  acc.db = db;
-  sqlite3VXPrintf(&acc, 1, zFormat, ap);
+  acc.printfFlags = SQLITE_PRINTF_INTERNAL;
+  sqlite3VXPrintf(&acc, zFormat, ap);
   z = sqlite3StrAccumFinish(&acc);
-  if( acc.mallocFailed ){
-    db->mallocFailed = 1;
+  if( acc.accError==STRACCUM_NOMEM ){
+    sqlite3OomFault(db);
   }
   return z;
 }
@@ -19776,37 +25607,25 @@ SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){
 }
 
 /*
-** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
-** the string and before returnning.  This routine is intended to be used
-** to modify an existing string.  For example:
-**
-**       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
-**
-*/
-SQLITE_PRIVATE char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
-  va_list ap;
-  char *z;
-  va_start(ap, zFormat);
-  z = sqlite3VMPrintf(db, zFormat, ap);
-  va_end(ap);
-  sqlite3DbFree(db, zStr);
-  return z;
-}
-
-/*
 ** Print into memory obtained from sqlite3_malloc().  Omit the internal
 ** %-conversion extensions.
 */
-SQLITE_API char *sqlite3_vmprintf(const char *zFormat, va_list ap){
+SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char *zFormat, va_list ap){
   char *z;
   char zBase[SQLITE_PRINT_BUF_SIZE];
   StrAccum acc;
+
+#ifdef SQLITE_ENABLE_API_ARMOR  
+  if( zFormat==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
 #ifndef SQLITE_OMIT_AUTOINIT
   if( sqlite3_initialize() ) return 0;
 #endif
-  sqlite3StrAccumInit(&acc, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
-  acc.useMalloc = 2;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   z = sqlite3StrAccumFinish(&acc);
   return z;
 }
@@ -19815,7 +25634,7 @@ SQLITE_API char *sqlite3_vmprintf(const char *zFormat, va_list ap){
 ** Print into memory obtained from sqlite3_malloc()().  Omit the internal
 ** %-conversion extensions.
 */
-SQLITE_API char *sqlite3_mprintf(const char *zFormat, ...){
+SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char *zFormat, ...){
   va_list ap;
   char *z;
 #ifndef SQLITE_OMIT_AUTOINIT
@@ -19840,15 +25659,21 @@ SQLITE_API char *sqlite3_mprintf(const char *zFormat, ...){
 **
 ** sqlite3_vsnprintf() is the varargs version.
 */
-SQLITE_API char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
+SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){
   StrAccum acc;
   if( n<=0 ) return zBuf;
-  sqlite3StrAccumInit(&acc, zBuf, n, 0);
-  acc.useMalloc = 0;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( zBuf==0 || zFormat==0 ) {
+    (void)SQLITE_MISUSE_BKPT;
+    if( zBuf ) zBuf[0] = 0;
+    return zBuf;
+  }
+#endif
+  sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   return sqlite3StrAccumFinish(&acc);
 }
-SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
+SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
   char *z;
   va_list ap;
   va_start(ap,zFormat);
@@ -19865,14 +25690,18 @@ SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
 ** sqlite3_log() must render into a static buffer.  It cannot dynamically
 ** allocate memory because it might be called while the memory allocator
 ** mutex is held.
+**
+** sqlite3VXPrintf() might ask for *temporary* memory allocations for
+** certain format characters (%q) or for very large precisions or widths.
+** Care must be taken that any sqlite3_log() calls that occur while the
+** memory mutex is held do not use these mechanisms.
 */
 static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
   StrAccum acc;                          /* String accumulator */
   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */
 
-  sqlite3StrAccumInit(&acc, zMsg, sizeof(zMsg), 0);
-  acc.useMalloc = 0;
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,
                            sqlite3StrAccumFinish(&acc));
 }
@@ -19880,7 +25709,7 @@ static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){
 /*
 ** Format and write a message to the log if logging is enabled.
 */
-SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...){
+SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...){
   va_list ap;                             /* Vararg list */
   if( sqlite3GlobalConfig.xLog ){
     va_start(ap, zFormat);
@@ -19889,7 +25718,7 @@ SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...){
   }
 }
 
-#if defined(SQLITE_DEBUG)
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
 /*
 ** A version of printf() that understands %lld.  Used for debugging.
 ** The printf() built into some versions of windows does not understand %lld
@@ -19899,10 +25728,9 @@ SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){
   va_list ap;
   StrAccum acc;
   char zBuf[500];
-  sqlite3StrAccumInit(&acc, zBuf, sizeof(zBuf), 0);
-  acc.useMalloc = 0;
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
   va_start(ap,zFormat);
-  sqlite3VXPrintf(&acc, 0, zFormat, ap);
+  sqlite3VXPrintf(&acc, zFormat, ap);
   va_end(ap);
   sqlite3StrAccumFinish(&acc);
   fprintf(stdout,"%s", zBuf);
@@ -19910,19 +25738,521 @@ SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){
 }
 #endif
 
-#ifndef SQLITE_OMIT_TRACE
+
 /*
-** variable-argument wrapper around sqlite3VXPrintf().
+** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
+** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.
 */
 SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, const char *zFormat, ...){
   va_list ap;
   va_start(ap,zFormat);
-  sqlite3VXPrintf(p, 1, zFormat, ap);
+  sqlite3VXPrintf(p, zFormat, ap);
   va_end(ap);
 }
-#endif
 
 /************** End of printf.c **********************************************/
+/************** Begin file treeview.c ****************************************/
+/*
+** 2015-06-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains C code to implement the TreeView debugging routines.
+** These routines print a parse tree to standard output for debugging and
+** analysis. 
+**
+** The interfaces in this file is only available when compiling
+** with SQLITE_DEBUG.
+*/
+/* #include "sqliteInt.h" */
+#ifdef SQLITE_DEBUG
+
+/*
+** Add a new subitem to the tree.  The moreToFollow flag indicates that this
+** is not the last item in the tree.
+*/
+static TreeView *sqlite3TreeViewPush(TreeView *p, u8 moreToFollow){
+  if( p==0 ){
+    p = sqlite3_malloc64( sizeof(*p) );
+    if( p==0 ) return 0;
+    memset(p, 0, sizeof(*p));
+  }else{
+    p->iLevel++;
+  }
+  assert( moreToFollow==0 || moreToFollow==1 );
+  if( p->iLevel<sizeof(p->bLine) ) p->bLine[p->iLevel] = moreToFollow;
+  return p;
+}
+
+/*
+** Finished with one layer of the tree
+*/
+static void sqlite3TreeViewPop(TreeView *p){
+  if( p==0 ) return;
+  p->iLevel--;
+  if( p->iLevel<0 ) sqlite3_free(p);
+}
+
+/*
+** Generate a single line of output for the tree, with a prefix that contains
+** all the appropriate tree lines
+*/
+static void sqlite3TreeViewLine(TreeView *p, const char *zFormat, ...){
+  va_list ap;
+  int i;
+  StrAccum acc;
+  char zBuf[500];
+  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
+  if( p ){
+    for(i=0; i<p->iLevel && i<sizeof(p->bLine)-1; i++){
+      sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|   " : "    ", 4);
+    }
+    sqlite3StrAccumAppend(&acc, p->bLine[i] ? "|-- " : "'-- ", 4);
+  }
+  va_start(ap, zFormat);
+  sqlite3VXPrintf(&acc, zFormat, ap);
+  va_end(ap);
+  if( zBuf[acc.nChar-1]!='\n' ) sqlite3StrAccumAppend(&acc, "\n", 1);
+  sqlite3StrAccumFinish(&acc);
+  fprintf(stdout,"%s", zBuf);
+  fflush(stdout);
+}
+
+/*
+** Shorthand for starting a new tree item that consists of a single label
+*/
+static void sqlite3TreeViewItem(TreeView *p, const char *zLabel,u8 moreFollows){
+  p = sqlite3TreeViewPush(p, moreFollows);
+  sqlite3TreeViewLine(p, "%s", zLabel);
+}
+
+/*
+** Generate a human-readable description of a WITH clause.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewWith(TreeView *pView, const With *pWith, u8 moreToFollow){
+  int i;
+  if( pWith==0 ) return;
+  if( pWith->nCte==0 ) return;
+  if( pWith->pOuter ){
+    sqlite3TreeViewLine(pView, "WITH (0x%p, pOuter=0x%p)",pWith,pWith->pOuter);
+  }else{
+    sqlite3TreeViewLine(pView, "WITH (0x%p)", pWith);
+  }
+  if( pWith->nCte>0 ){
+    pView = sqlite3TreeViewPush(pView, 1);
+    for(i=0; i<pWith->nCte; i++){
+      StrAccum x;
+      char zLine[1000];
+      const struct Cte *pCte = &pWith->a[i];
+      sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
+      sqlite3XPrintf(&x, "%s", pCte->zName);
+      if( pCte->pCols && pCte->pCols->nExpr>0 ){
+        char cSep = '(';
+        int j;
+        for(j=0; j<pCte->pCols->nExpr; j++){
+          sqlite3XPrintf(&x, "%c%s", cSep, pCte->pCols->a[j].zName);
+          cSep = ',';
+        }
+        sqlite3XPrintf(&x, ")");
+      }
+      sqlite3XPrintf(&x, " AS");
+      sqlite3StrAccumFinish(&x);
+      sqlite3TreeViewItem(pView, zLine, i<pWith->nCte-1);
+      sqlite3TreeViewSelect(pView, pCte->pSelect, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    sqlite3TreeViewPop(pView);
+  }
+}
+
+
+/*
+** Generate a human-readable description of a the Select object.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){
+  int n = 0;
+  int cnt = 0;
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  if( p->pWith ){
+    sqlite3TreeViewWith(pView, p->pWith, 1);
+    cnt = 1;
+    sqlite3TreeViewPush(pView, 1);
+  }
+  do{
+    sqlite3TreeViewLine(pView, "SELECT%s%s (0x%p) selFlags=0x%x nSelectRow=%d",
+      ((p->selFlags & SF_Distinct) ? " DISTINCT" : ""),
+      ((p->selFlags & SF_Aggregate) ? " agg_flag" : ""), p, p->selFlags,
+      (int)p->nSelectRow
+    );
+    if( cnt++ ) sqlite3TreeViewPop(pView);
+    if( p->pPrior ){
+      n = 1000;
+    }else{
+      n = 0;
+      if( p->pSrc && p->pSrc->nSrc ) n++;
+      if( p->pWhere ) n++;
+      if( p->pGroupBy ) n++;
+      if( p->pHaving ) n++;
+      if( p->pOrderBy ) n++;
+      if( p->pLimit ) n++;
+      if( p->pOffset ) n++;
+    }
+    sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");
+    if( p->pSrc && p->pSrc->nSrc ){
+      int i;
+      pView = sqlite3TreeViewPush(pView, (n--)>0);
+      sqlite3TreeViewLine(pView, "FROM");
+      for(i=0; i<p->pSrc->nSrc; i++){
+        struct SrcList_item *pItem = &p->pSrc->a[i];
+        StrAccum x;
+        char zLine[100];
+        sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
+        sqlite3XPrintf(&x, "{%d,*}", pItem->iCursor);
+        if( pItem->zDatabase ){
+          sqlite3XPrintf(&x, " %s.%s", pItem->zDatabase, pItem->zName);
+        }else if( pItem->zName ){
+          sqlite3XPrintf(&x, " %s", pItem->zName);
+        }
+        if( pItem->pTab ){
+          sqlite3XPrintf(&x, " tabname=%Q", pItem->pTab->zName);
+        }
+        if( pItem->zAlias ){
+          sqlite3XPrintf(&x, " (AS %s)", pItem->zAlias);
+        }
+        if( pItem->fg.jointype & JT_LEFT ){
+          sqlite3XPrintf(&x, " LEFT-JOIN");
+        }
+        sqlite3StrAccumFinish(&x);
+        sqlite3TreeViewItem(pView, zLine, i<p->pSrc->nSrc-1); 
+        if( pItem->pSelect ){
+          sqlite3TreeViewSelect(pView, pItem->pSelect, 0);
+        }
+        if( pItem->fg.isTabFunc ){
+          sqlite3TreeViewExprList(pView, pItem->u1.pFuncArg, 0, "func-args:");
+        }
+        sqlite3TreeViewPop(pView);
+      }
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pWhere ){
+      sqlite3TreeViewItem(pView, "WHERE", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pWhere, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pGroupBy ){
+      sqlite3TreeViewExprList(pView, p->pGroupBy, (n--)>0, "GROUPBY");
+    }
+    if( p->pHaving ){
+      sqlite3TreeViewItem(pView, "HAVING", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pHaving, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pOrderBy ){
+      sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");
+    }
+    if( p->pLimit ){
+      sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pLimit, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pOffset ){
+      sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);
+      sqlite3TreeViewExpr(pView, p->pOffset, 0);
+      sqlite3TreeViewPop(pView);
+    }
+    if( p->pPrior ){
+      const char *zOp = "UNION";
+      switch( p->op ){
+        case TK_ALL:         zOp = "UNION ALL";  break;
+        case TK_INTERSECT:   zOp = "INTERSECT";  break;
+        case TK_EXCEPT:      zOp = "EXCEPT";     break;
+      }
+      sqlite3TreeViewItem(pView, zOp, 1);
+    }
+    p = p->pPrior;
+  }while( p!=0 );
+  sqlite3TreeViewPop(pView);
+}
+
+/*
+** Generate a human-readable explanation of an expression tree.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){
+  const char *zBinOp = 0;   /* Binary operator */
+  const char *zUniOp = 0;   /* Unary operator */
+  char zFlgs[30];
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  if( pExpr==0 ){
+    sqlite3TreeViewLine(pView, "nil");
+    sqlite3TreeViewPop(pView);
+    return;
+  }
+  if( pExpr->flags ){
+    sqlite3_snprintf(sizeof(zFlgs),zFlgs,"  flags=0x%x",pExpr->flags);
+  }else{
+    zFlgs[0] = 0;
+  }
+  switch( pExpr->op ){
+    case TK_AGG_COLUMN: {
+      sqlite3TreeViewLine(pView, "AGG{%d:%d}%s",
+            pExpr->iTable, pExpr->iColumn, zFlgs);
+      break;
+    }
+    case TK_COLUMN: {
+      if( pExpr->iTable<0 ){
+        /* This only happens when coding check constraints */
+        sqlite3TreeViewLine(pView, "COLUMN(%d)%s", pExpr->iColumn, zFlgs);
+      }else{
+        sqlite3TreeViewLine(pView, "{%d:%d}%s",
+                             pExpr->iTable, pExpr->iColumn, zFlgs);
+      }
+      break;
+    }
+    case TK_INTEGER: {
+      if( pExpr->flags & EP_IntValue ){
+        sqlite3TreeViewLine(pView, "%d", pExpr->u.iValue);
+      }else{
+        sqlite3TreeViewLine(pView, "%s", pExpr->u.zToken);
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    case TK_FLOAT: {
+      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_STRING: {
+      sqlite3TreeViewLine(pView,"%Q", pExpr->u.zToken);
+      break;
+    }
+    case TK_NULL: {
+      sqlite3TreeViewLine(pView,"NULL");
+      break;
+    }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case TK_BLOB: {
+      sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_VARIABLE: {
+      sqlite3TreeViewLine(pView,"VARIABLE(%s,%d)",
+                          pExpr->u.zToken, pExpr->iColumn);
+      break;
+    }
+    case TK_REGISTER: {
+      sqlite3TreeViewLine(pView,"REGISTER(%d)", pExpr->iTable);
+      break;
+    }
+    case TK_ID: {
+      sqlite3TreeViewLine(pView,"ID \"%w\"", pExpr->u.zToken);
+      break;
+    }
+#ifndef SQLITE_OMIT_CAST
+    case TK_CAST: {
+      /* Expressions of the form:   CAST(pLeft AS token) */
+      sqlite3TreeViewLine(pView,"CAST %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+#endif /* SQLITE_OMIT_CAST */
+    case TK_LT:      zBinOp = "LT";     break;
+    case TK_LE:      zBinOp = "LE";     break;
+    case TK_GT:      zBinOp = "GT";     break;
+    case TK_GE:      zBinOp = "GE";     break;
+    case TK_NE:      zBinOp = "NE";     break;
+    case TK_EQ:      zBinOp = "EQ";     break;
+    case TK_IS:      zBinOp = "IS";     break;
+    case TK_ISNOT:   zBinOp = "ISNOT";  break;
+    case TK_AND:     zBinOp = "AND";    break;
+    case TK_OR:      zBinOp = "OR";     break;
+    case TK_PLUS:    zBinOp = "ADD";    break;
+    case TK_STAR:    zBinOp = "MUL";    break;
+    case TK_MINUS:   zBinOp = "SUB";    break;
+    case TK_REM:     zBinOp = "REM";    break;
+    case TK_BITAND:  zBinOp = "BITAND"; break;
+    case TK_BITOR:   zBinOp = "BITOR";  break;
+    case TK_SLASH:   zBinOp = "DIV";    break;
+    case TK_LSHIFT:  zBinOp = "LSHIFT"; break;
+    case TK_RSHIFT:  zBinOp = "RSHIFT"; break;
+    case TK_CONCAT:  zBinOp = "CONCAT"; break;
+    case TK_DOT:     zBinOp = "DOT";    break;
+
+    case TK_UMINUS:  zUniOp = "UMINUS"; break;
+    case TK_UPLUS:   zUniOp = "UPLUS";  break;
+    case TK_BITNOT:  zUniOp = "BITNOT"; break;
+    case TK_NOT:     zUniOp = "NOT";    break;
+    case TK_ISNULL:  zUniOp = "ISNULL"; break;
+    case TK_NOTNULL: zUniOp = "NOTNULL"; break;
+
+    case TK_SPAN: {
+      sqlite3TreeViewLine(pView, "SPAN %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+
+    case TK_COLLATE: {
+      sqlite3TreeViewLine(pView, "COLLATE %Q", pExpr->u.zToken);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
+
+    case TK_AGG_FUNCTION:
+    case TK_FUNCTION: {
+      ExprList *pFarg;       /* List of function arguments */
+      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
+        pFarg = 0;
+      }else{
+        pFarg = pExpr->x.pList;
+      }
+      if( pExpr->op==TK_AGG_FUNCTION ){
+        sqlite3TreeViewLine(pView, "AGG_FUNCTION%d %Q",
+                             pExpr->op2, pExpr->u.zToken);
+      }else{
+        sqlite3TreeViewLine(pView, "FUNCTION %Q", pExpr->u.zToken);
+      }
+      if( pFarg ){
+        sqlite3TreeViewExprList(pView, pFarg, 0, 0);
+      }
+      break;
+    }
+#ifndef SQLITE_OMIT_SUBQUERY
+    case TK_EXISTS: {
+      sqlite3TreeViewLine(pView, "EXISTS-expr");
+      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      break;
+    }
+    case TK_SELECT: {
+      sqlite3TreeViewLine(pView, "SELECT-expr");
+      sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      break;
+    }
+    case TK_IN: {
+      sqlite3TreeViewLine(pView, "IN");
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);
+      }else{
+        sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
+      }
+      break;
+    }
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+    /*
+    **    x BETWEEN y AND z
+    **
+    ** This is equivalent to
+    **
+    **    x>=y AND x<=z
+    **
+    ** X is stored in pExpr->pLeft.
+    ** Y is stored in pExpr->pList->a[0].pExpr.
+    ** Z is stored in pExpr->pList->a[1].pExpr.
+    */
+    case TK_BETWEEN: {
+      Expr *pX = pExpr->pLeft;
+      Expr *pY = pExpr->x.pList->a[0].pExpr;
+      Expr *pZ = pExpr->x.pList->a[1].pExpr;
+      sqlite3TreeViewLine(pView, "BETWEEN");
+      sqlite3TreeViewExpr(pView, pX, 1);
+      sqlite3TreeViewExpr(pView, pY, 1);
+      sqlite3TreeViewExpr(pView, pZ, 0);
+      break;
+    }
+    case TK_TRIGGER: {
+      /* If the opcode is TK_TRIGGER, then the expression is a reference
+      ** to a column in the new.* or old.* pseudo-tables available to
+      ** trigger programs. In this case Expr.iTable is set to 1 for the
+      ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
+      ** is set to the column of the pseudo-table to read, or to -1 to
+      ** read the rowid field.
+      */
+      sqlite3TreeViewLine(pView, "%s(%d)", 
+          pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
+      break;
+    }
+    case TK_CASE: {
+      sqlite3TreeViewLine(pView, "CASE");
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+      sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);
+      break;
+    }
+#ifndef SQLITE_OMIT_TRIGGER
+    case TK_RAISE: {
+      const char *zType = "unk";
+      switch( pExpr->affinity ){
+        case OE_Rollback:   zType = "rollback";  break;
+        case OE_Abort:      zType = "abort";     break;
+        case OE_Fail:       zType = "fail";      break;
+        case OE_Ignore:     zType = "ignore";    break;
+      }
+      sqlite3TreeViewLine(pView, "RAISE %s(%Q)", zType, pExpr->u.zToken);
+      break;
+    }
+#endif
+    case TK_MATCH: {
+      sqlite3TreeViewLine(pView, "MATCH {%d:%d}%s",
+                          pExpr->iTable, pExpr->iColumn, zFlgs);
+      sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
+      break;
+    }
+    default: {
+      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
+      break;
+    }
+  }
+  if( zBinOp ){
+    sqlite3TreeViewLine(pView, "%s%s", zBinOp, zFlgs);
+    sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
+    sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
+  }else if( zUniOp ){
+    sqlite3TreeViewLine(pView, "%s%s", zUniOp, zFlgs);
+    sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+  }
+  sqlite3TreeViewPop(pView);
+}
+
+/*
+** Generate a human-readable explanation of an expression list.
+*/
+SQLITE_PRIVATE void sqlite3TreeViewExprList(
+  TreeView *pView,
+  const ExprList *pList,
+  u8 moreToFollow,
+  const char *zLabel
+){
+  int i;
+  pView = sqlite3TreeViewPush(pView, moreToFollow);
+  if( zLabel==0 || zLabel[0]==0 ) zLabel = "LIST";
+  if( pList==0 ){
+    sqlite3TreeViewLine(pView, "%s (empty)", zLabel);
+  }else{
+    sqlite3TreeViewLine(pView, "%s", zLabel);
+    for(i=0; i<pList->nExpr; i++){
+      int j = pList->a[i].u.x.iOrderByCol;
+      if( j ){
+        sqlite3TreeViewPush(pView, 0);
+        sqlite3TreeViewLine(pView, "iOrderByCol=%d", j);
+      }
+      sqlite3TreeViewExpr(pView, pList->a[i].pExpr, i<pList->nExpr-1);
+      if( j ) sqlite3TreeViewPop(pView);
+    }
+  }
+  sqlite3TreeViewPop(pView);
+}
+
+#endif /* SQLITE_DEBUG */
+
+/************** End of treeview.c ********************************************/
 /************** Begin file random.c ******************************************/
 /*
 ** 2001 September 15
@@ -19941,6 +26271,7 @@ SQLITE_PRIVATE void sqlite3XPrintf(StrAccum *p, const char *zFormat, ...){
 ** Random numbers are used by some of the database backends in order
 ** to generate random integer keys for tables or random filenames.
 */
+/* #include "sqliteInt.h" */
 
 
 /* All threads share a single random number generator.
@@ -19953,24 +26284,11 @@ static SQLITE_WSD struct sqlite3PrngType {
 } sqlite3Prng;
 
 /*
-** Get a single 8-bit random value from the RC4 PRNG.  The Mutex
-** must be held while executing this routine.
-**
-** Why not just use a library random generator like lrand48() for this?
-** Because the OP_NewRowid opcode in the VDBE depends on having a very
-** good source of random numbers.  The lrand48() library function may
-** well be good enough.  But maybe not.  Or maybe lrand48() has some
-** subtle problems on some systems that could cause problems.  It is hard
-** to know.  To minimize the risk of problems due to bad lrand48()
-** implementations, SQLite uses this random number generator based
-** on RC4, which we know works very well.
-**
-** (Later):  Actually, OP_NewRowid does not depend on a good source of
-** randomness any more.  But we will leave this code in all the same.
+** Return N random bytes.
 */
-static u8 randomByte(void){
+SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *pBuf){
   unsigned char t;
-
+  unsigned char *zBuf = pBuf;
 
   /* The "wsdPrng" macro will resolve to the pseudo-random number generator
   ** state vector.  If writable static data is unsupported on the target,
@@ -19985,6 +26303,24 @@ static u8 randomByte(void){
 # define wsdPrng sqlite3Prng
 #endif
 
+#if SQLITE_THREADSAFE
+  sqlite3_mutex *mutex;
+#endif
+
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return;
+#endif
+
+#if SQLITE_THREADSAFE
+  mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);
+#endif
+
+  sqlite3_mutex_enter(mutex);
+  if( N<=0 || pBuf==0 ){
+    wsdPrng.isInit = 0;
+    sqlite3_mutex_leave(mutex);
+    return;
+  }
 
   /* Initialize the state of the random number generator once,
   ** the first time this routine is called.  The seed value does
@@ -20013,29 +26349,16 @@ static u8 randomByte(void){
     wsdPrng.isInit = 1;
   }
 
-  /* Generate and return single random byte
-  */
-  wsdPrng.i++;
-  t = wsdPrng.s[wsdPrng.i];
-  wsdPrng.j += t;
-  wsdPrng.s[wsdPrng.i] = wsdPrng.s[wsdPrng.j];
-  wsdPrng.s[wsdPrng.j] = t;
-  t += wsdPrng.s[wsdPrng.i];
-  return wsdPrng.s[t];
-}
-
-/*
-** Return N random bytes.
-*/
-SQLITE_API void sqlite3_randomness(int N, void *pBuf){
-  unsigned char *zBuf = pBuf;
-#if SQLITE_THREADSAFE
-  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);
-#endif
-  sqlite3_mutex_enter(mutex);
-  while( N-- ){
-    *(zBuf++) = randomByte();
-  }
+  assert( N>0 );
+  do{
+    wsdPrng.i++;
+    t = wsdPrng.s[wsdPrng.i];
+    wsdPrng.j += t;
+    wsdPrng.s[wsdPrng.i] = wsdPrng.s[wsdPrng.j];
+    wsdPrng.s[wsdPrng.j] = t;
+    t += wsdPrng.s[wsdPrng.i];
+    *(zBuf++) = wsdPrng.s[t];
+  }while( --N );
   sqlite3_mutex_leave(mutex);
 }
 
@@ -20064,12 +26387,286 @@ SQLITE_PRIVATE void sqlite3PrngRestoreState(void){
     sizeof(sqlite3Prng)
   );
 }
-SQLITE_PRIVATE void sqlite3PrngResetState(void){
-  GLOBAL(struct sqlite3PrngType, sqlite3Prng).isInit = 0;
-}
 #endif /* SQLITE_OMIT_BUILTIN_TEST */
 
 /************** End of random.c **********************************************/
+/************** Begin file threads.c *****************************************/
+/*
+** 2012 July 21
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file presents a simple cross-platform threading interface for
+** use internally by SQLite.
+**
+** A "thread" can be created using sqlite3ThreadCreate().  This thread
+** runs independently of its creator until it is joined using
+** sqlite3ThreadJoin(), at which point it terminates.
+**
+** Threads do not have to be real.  It could be that the work of the
+** "thread" is done by the main thread at either the sqlite3ThreadCreate()
+** or sqlite3ThreadJoin() call.  This is, in fact, what happens in
+** single threaded systems.  Nothing in SQLite requires multiple threads.
+** This interface exists so that applications that want to take advantage
+** of multiple cores can do so, while also allowing applications to stay
+** single-threaded if desired.
+*/
+/* #include "sqliteInt.h" */
+#if SQLITE_OS_WIN
+/* #  include "os_win.h" */
+#endif
+
+#if SQLITE_MAX_WORKER_THREADS>0
+
+/********************************* Unix Pthreads ****************************/
+#if SQLITE_OS_UNIX && defined(SQLITE_MUTEX_PTHREADS) && SQLITE_THREADSAFE>0
+
+#define SQLITE_THREADS_IMPLEMENTED 1  /* Prevent the single-thread code below */
+/* #include <pthread.h> */
+
+/* A running thread */
+struct SQLiteThread {
+  pthread_t tid;                 /* Thread ID */
+  int done;                      /* Set to true when thread finishes */
+  void *pOut;                    /* Result returned by the thread */
+  void *(*xTask)(void*);         /* The thread routine */
+  void *pIn;                     /* Argument to the thread */
+};
+
+/* Create a new thread */
+SQLITE_PRIVATE int sqlite3ThreadCreate(
+  SQLiteThread **ppThread,  /* OUT: Write the thread object here */
+  void *(*xTask)(void*),    /* Routine to run in a separate thread */
+  void *pIn                 /* Argument passed into xTask() */
+){
+  SQLiteThread *p;
+  int rc;
+
+  assert( ppThread!=0 );
+  assert( xTask!=0 );
+  /* This routine is never used in single-threaded mode */
+  assert( sqlite3GlobalConfig.bCoreMutex!=0 );
+
+  *ppThread = 0;
+  p = sqlite3Malloc(sizeof(*p));
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  memset(p, 0, sizeof(*p));
+  p->xTask = xTask;
+  p->pIn = pIn;
+  /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 
+  ** function that returns SQLITE_ERROR when passed the argument 200, that
+  ** forces worker threads to run sequentially and deterministically 
+  ** for testing purposes. */
+  if( sqlite3FaultSim(200) ){
+    rc = 1;
+  }else{    
+    rc = pthread_create(&p->tid, 0, xTask, pIn);
+  }
+  if( rc ){
+    p->done = 1;
+    p->pOut = xTask(pIn);
+  }
+  *ppThread = p;
+  return SQLITE_OK;
+}
+
+/* Get the results of the thread */
+SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
+  int rc;
+
+  assert( ppOut!=0 );
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
+  if( p->done ){
+    *ppOut = p->pOut;
+    rc = SQLITE_OK;
+  }else{
+    rc = pthread_join(p->tid, ppOut) ? SQLITE_ERROR : SQLITE_OK;
+  }
+  sqlite3_free(p);
+  return rc;
+}
+
+#endif /* SQLITE_OS_UNIX && defined(SQLITE_MUTEX_PTHREADS) */
+/******************************** End Unix Pthreads *************************/
+
+
+/********************************* Win32 Threads ****************************/
+#if SQLITE_OS_WIN_THREADS
+
+#define SQLITE_THREADS_IMPLEMENTED 1  /* Prevent the single-thread code below */
+#include <process.h>
+
+/* A running thread */
+struct SQLiteThread {
+  void *tid;               /* The thread handle */
+  unsigned id;             /* The thread identifier */
+  void *(*xTask)(void*);   /* The routine to run as a thread */
+  void *pIn;               /* Argument to xTask */
+  void *pResult;           /* Result of xTask */
+};
+
+/* Thread procedure Win32 compatibility shim */
+static unsigned __stdcall sqlite3ThreadProc(
+  void *pArg  /* IN: Pointer to the SQLiteThread structure */
+){
+  SQLiteThread *p = (SQLiteThread *)pArg;
+
+  assert( p!=0 );
+#if 0
+  /*
+  ** This assert appears to trigger spuriously on certain
+  ** versions of Windows, possibly due to _beginthreadex()
+  ** and/or CreateThread() not fully setting their thread
+  ** ID parameter before starting the thread.
+  */
+  assert( p->id==GetCurrentThreadId() );
+#endif
+  assert( p->xTask!=0 );
+  p->pResult = p->xTask(p->pIn);
+
+  _endthreadex(0);
+  return 0; /* NOT REACHED */
+}
+
+/* Create a new thread */
+SQLITE_PRIVATE int sqlite3ThreadCreate(
+  SQLiteThread **ppThread,  /* OUT: Write the thread object here */
+  void *(*xTask)(void*),    /* Routine to run in a separate thread */
+  void *pIn                 /* Argument passed into xTask() */
+){
+  SQLiteThread *p;
+
+  assert( ppThread!=0 );
+  assert( xTask!=0 );
+  *ppThread = 0;
+  p = sqlite3Malloc(sizeof(*p));
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 
+  ** function that returns SQLITE_ERROR when passed the argument 200, that
+  ** forces worker threads to run sequentially and deterministically 
+  ** (via the sqlite3FaultSim() term of the conditional) for testing
+  ** purposes. */
+  if( sqlite3GlobalConfig.bCoreMutex==0 || sqlite3FaultSim(200) ){
+    memset(p, 0, sizeof(*p));
+  }else{
+    p->xTask = xTask;
+    p->pIn = pIn;
+    p->tid = (void*)_beginthreadex(0, 0, sqlite3ThreadProc, p, 0, &p->id);
+    if( p->tid==0 ){
+      memset(p, 0, sizeof(*p));
+    }
+  }
+  if( p->xTask==0 ){
+    p->id = GetCurrentThreadId();
+    p->pResult = xTask(pIn);
+  }
+  *ppThread = p;
+  return SQLITE_OK;
+}
+
+SQLITE_PRIVATE DWORD sqlite3Win32Wait(HANDLE hObject); /* os_win.c */
+
+/* Get the results of the thread */
+SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
+  DWORD rc;
+  BOOL bRc;
+
+  assert( ppOut!=0 );
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
+  if( p->xTask==0 ){
+    /* assert( p->id==GetCurrentThreadId() ); */
+    rc = WAIT_OBJECT_0;
+    assert( p->tid==0 );
+  }else{
+    assert( p->id!=0 && p->id!=GetCurrentThreadId() );
+    rc = sqlite3Win32Wait((HANDLE)p->tid);
+    assert( rc!=WAIT_IO_COMPLETION );
+    bRc = CloseHandle((HANDLE)p->tid);
+    assert( bRc );
+  }
+  if( rc==WAIT_OBJECT_0 ) *ppOut = p->pResult;
+  sqlite3_free(p);
+  return (rc==WAIT_OBJECT_0) ? SQLITE_OK : SQLITE_ERROR;
+}
+
+#endif /* SQLITE_OS_WIN_THREADS */
+/******************************** End Win32 Threads *************************/
+
+
+/********************************* Single-Threaded **************************/
+#ifndef SQLITE_THREADS_IMPLEMENTED
+/*
+** This implementation does not actually create a new thread.  It does the
+** work of the thread in the main thread, when either the thread is created
+** or when it is joined
+*/
+
+/* A running thread */
+struct SQLiteThread {
+  void *(*xTask)(void*);   /* The routine to run as a thread */
+  void *pIn;               /* Argument to xTask */
+  void *pResult;           /* Result of xTask */
+};
+
+/* Create a new thread */
+SQLITE_PRIVATE int sqlite3ThreadCreate(
+  SQLiteThread **ppThread,  /* OUT: Write the thread object here */
+  void *(*xTask)(void*),    /* Routine to run in a separate thread */
+  void *pIn                 /* Argument passed into xTask() */
+){
+  SQLiteThread *p;
+
+  assert( ppThread!=0 );
+  assert( xTask!=0 );
+  *ppThread = 0;
+  p = sqlite3Malloc(sizeof(*p));
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  if( (SQLITE_PTR_TO_INT(p)/17)&1 ){
+    p->xTask = xTask;
+    p->pIn = pIn;
+  }else{
+    p->xTask = 0;
+    p->pResult = xTask(pIn);
+  }
+  *ppThread = p;
+  return SQLITE_OK;
+}
+
+/* Get the results of the thread */
+SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){
+
+  assert( ppOut!=0 );
+  if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;
+  if( p->xTask ){
+    *ppOut = p->xTask(p->pIn);
+  }else{
+    *ppOut = p->pResult;
+  }
+  sqlite3_free(p);
+
+#if defined(SQLITE_TEST)
+  {
+    void *pTstAlloc = sqlite3Malloc(10);
+    if (!pTstAlloc) return SQLITE_NOMEM_BKPT;
+    sqlite3_free(pTstAlloc);
+  }
+#endif
+
+  return SQLITE_OK;
+}
+
+#endif /* !defined(SQLITE_THREADS_IMPLEMENTED) */
+/****************************** End Single-Threaded *************************/
+#endif /* SQLITE_MAX_WORKER_THREADS>0 */
+
+/************** End of threads.c *********************************************/
 /************** Begin file utf.c *********************************************/
 /*
 ** 2004 April 13
@@ -20106,15 +26703,17 @@ SQLITE_PRIVATE void sqlite3PrngResetState(void){
 **     0xfe 0xff   big-endian utf-16 follows
 **
 */
+/* #include "sqliteInt.h" */
 /* #include <assert.h> */
+/* #include "vdbeInt.h" */
 
-#ifndef SQLITE_AMALGAMATION
+#if !defined(SQLITE_AMALGAMATION) && SQLITE_BYTEORDER==0
 /*
 ** The following constant value is used by the SQLITE_BIGENDIAN and
 ** SQLITE_LITTLEENDIAN macros.
 */
 SQLITE_PRIVATE const int sqlite3one = 1;
-#endif /* SQLITE_AMALGAMATION */
+#endif /* SQLITE_AMALGAMATION && SQLITE_BYTEORDER==0 */
 
 /*
 ** This lookup table is used to help decode the first byte of
@@ -20219,8 +26818,8 @@ static const unsigned char sqlite3Utf8Trans1[] = {
 **     and rendered as themselves even though they are technically
 **     invalid characters.
 **
-**  *  This routine accepts an infinite number of different UTF8 encodings
-**     for unicode values 0x80 and greater.  It do not change over-length
+**  *  This routine accepts over-length UTF8 encodings
+**     for unicode values 0x80 and greater.  It does not change over-length
 **     encodings to 0xfffd as some systems recommend.
 */
 #define READ_UTF8(zIn, zTerm, c)                           \
@@ -20235,25 +26834,23 @@ static const unsigned char sqlite3Utf8Trans1[] = {
         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
   }
 SQLITE_PRIVATE u32 sqlite3Utf8Read(
-  const unsigned char *zIn,       /* First byte of UTF-8 character */
-  const unsigned char **pzNext    /* Write first byte past UTF-8 char here */
+  const unsigned char **pz    /* Pointer to string from which to read char */
 ){
   unsigned int c;
 
   /* Same as READ_UTF8() above but without the zTerm parameter.
   ** For this routine, we assume the UTF8 string is always zero-terminated.
   */
-  c = *(zIn++);
+  c = *((*pz)++);
   if( c>=0xc0 ){
     c = sqlite3Utf8Trans1[c-0xc0];
-    while( (*zIn & 0xc0)==0x80 ){
-      c = (c<<6) + (0x3f & *(zIn++));
+    while( (*(*pz) & 0xc0)==0x80 ){
+      c = (c<<6) + (0x3f & *((*pz)++));
     }
     if( c<0x80
         || (c&0xFFFFF800)==0xD800
         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }
   }
-  *pzNext = zIn;
   return c;
 }
 
@@ -20272,7 +26869,7 @@ SQLITE_PRIVATE u32 sqlite3Utf8Read(
 ** desiredEnc. It is an error if the string is already of the desired
 ** encoding, or if *pMem does not contain a string value.
 */
-SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
+SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
   int len;                    /* Maximum length of output string in bytes */
   unsigned char *zOut;                  /* Output buffer */
   unsigned char *zIn;                   /* Input iterator */
@@ -20304,7 +26901,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
     rc = sqlite3VdbeMemMakeWriteable(pMem);
     if( rc!=SQLITE_OK ){
       assert( rc==SQLITE_NOMEM );
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     zIn = (u8*)pMem->z;
     zTerm = &zIn[pMem->n&~1];
@@ -20346,7 +26943,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
   zTerm = &zIn[pMem->n];
   zOut = sqlite3DbMallocRaw(pMem->db, len);
   if( !zOut ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   z = zOut;
 
@@ -20354,7 +26951,6 @@ SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
     if( desiredEnc==SQLITE_UTF16LE ){
       /* UTF-8 -> UTF-16 Little-endian */
       while( zIn<zTerm ){
-        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
         READ_UTF8(zIn, zTerm, c);
         WRITE_UTF16LE(z, c);
       }
@@ -20362,7 +26958,6 @@ SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
       assert( desiredEnc==SQLITE_UTF16BE );
       /* UTF-8 -> UTF-16 Big-endian */
       while( zIn<zTerm ){
-        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
         READ_UTF8(zIn, zTerm, c);
         WRITE_UTF16BE(z, c);
       }
@@ -20389,12 +26984,13 @@ SQLITE_PRIVATE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
   *z = 0;
   assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );
 
+  c = pMem->flags;
   sqlite3VdbeMemRelease(pMem);
-  pMem->flags &= ~(MEM_Static|MEM_Dyn|MEM_Ephem);
+  pMem->flags = MEM_Str|MEM_Term|(c&(MEM_AffMask|MEM_Subtype));
   pMem->enc = desiredEnc;
-  pMem->flags |= (MEM_Term|MEM_Dyn);
   pMem->z = (char*)zOut;
   pMem->zMalloc = pMem->z;
+  pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->z);
 
 translate_out:
 #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
@@ -20490,7 +27086,7 @@ SQLITE_PRIVATE int sqlite3Utf8To8(unsigned char *zIn){
   u32 c;
 
   while( zIn[0] && zOut<=zIn ){
-    c = sqlite3Utf8Read(zIn, (const u8**)&zIn);
+    c = sqlite3Utf8Read((const u8**)&zIn);
     if( c!=0xfffd ){
       WRITE_UTF8(zOut, c);
     }
@@ -20520,38 +27116,11 @@ SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte, u8 e
   }
   assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
   assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
-  assert( (m.flags & MEM_Dyn)!=0 || db->mallocFailed );
   assert( m.z || db->mallocFailed );
   return m.z;
 }
 
 /*
-** Convert a UTF-8 string to the UTF-16 encoding specified by parameter
-** enc. A pointer to the new string is returned, and the value of *pnOut
-** is set to the length of the returned string in bytes. The call should
-** arrange to call sqlite3DbFree() on the returned pointer when it is
-** no longer required.
-** 
-** If a malloc failure occurs, NULL is returned and the db.mallocFailed
-** flag set.
-*/
-#ifdef SQLITE_ENABLE_STAT3
-SQLITE_PRIVATE char *sqlite3Utf8to16(sqlite3 *db, u8 enc, char *z, int n, int *pnOut){
-  Mem m;
-  memset(&m, 0, sizeof(m));
-  m.db = db;
-  sqlite3VdbeMemSetStr(&m, z, n, SQLITE_UTF8, SQLITE_STATIC);
-  if( sqlite3VdbeMemTranslate(&m, enc) ){
-    assert( db->mallocFailed );
-    return 0;
-  }
-  assert( m.z==m.zMalloc );
-  *pnOut = m.n;
-  return m.z;
-}
-#endif
-
-/*
 ** zIn is a UTF-16 encoded unicode string at least nChar characters long.
 ** Return the number of bytes in the first nChar unicode characters
 ** in pZ.  nChar must be non-negative.
@@ -20595,7 +27164,7 @@ SQLITE_PRIVATE void sqlite3UtfSelfTest(void){
     assert( n>0 && n<=4 );
     z[0] = 0;
     z = zBuf;
-    c = sqlite3Utf8Read(z, (const u8**)&z);
+    c = sqlite3Utf8Read((const u8**)&z);
     t = i;
     if( i>=0xD800 && i<=0xDFFF ) t = 0xFFFD;
     if( (i&0xFFFFFFFE)==0xFFFE ) t = 0xFFFD;
@@ -20649,8 +27218,9 @@ SQLITE_PRIVATE void sqlite3UtfSelfTest(void){
 ** strings, and stuff like that.
 **
 */
+/* #include "sqliteInt.h" */
 /* #include <stdarg.h> */
-#ifdef SQLITE_HAVE_ISNAN
+#if HAVE_ISNAN || SQLITE_HAVE_ISNAN
 # include <math.h>
 #endif
 
@@ -20664,6 +27234,24 @@ SQLITE_PRIVATE void sqlite3Coverage(int x){
 }
 #endif
 
+/*
+** Give a callback to the test harness that can be used to simulate faults
+** in places where it is difficult or expensive to do so purely by means
+** of inputs.
+**
+** The intent of the integer argument is to let the fault simulator know
+** which of multiple sqlite3FaultSim() calls has been hit.
+**
+** Return whatever integer value the test callback returns, or return
+** SQLITE_OK if no test callback is installed.
+*/
+#ifndef SQLITE_OMIT_BUILTIN_TEST
+SQLITE_PRIVATE int sqlite3FaultSim(int iTest){
+  int (*xCallback)(int) = sqlite3GlobalConfig.xTestCallback;
+  return xCallback ? xCallback(iTest) : SQLITE_OK;
+}
+#endif
+
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Return true if the floating point value is Not a Number (NaN).
@@ -20673,7 +27261,7 @@ SQLITE_PRIVATE void sqlite3Coverage(int x){
 */
 SQLITE_PRIVATE int sqlite3IsNaN(double x){
   int rc;   /* The value return */
-#if !defined(SQLITE_HAVE_ISNAN)
+#if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN
   /*
   ** Systems that support the isnan() library function should probably
   ** make use of it by compiling with -DSQLITE_HAVE_ISNAN.  But we have
@@ -20703,9 +27291,9 @@ SQLITE_PRIVATE int sqlite3IsNaN(double x){
   volatile double y = x;
   volatile double z = y;
   rc = (y!=z);
-#else  /* if defined(SQLITE_HAVE_ISNAN) */
+#else  /* if HAVE_ISNAN */
   rc = isnan(x);
-#endif /* SQLITE_HAVE_ISNAN */
+#endif /* HAVE_ISNAN */
   testcase( rc );
   return rc;
 }
@@ -20720,10 +27308,53 @@ SQLITE_PRIVATE int sqlite3IsNaN(double x){
 ** than 1GiB) the value returned might be less than the true string length.
 */
 SQLITE_PRIVATE int sqlite3Strlen30(const char *z){
-  const char *z2 = z;
   if( z==0 ) return 0;
-  while( *z2 ){ z2++; }
-  return 0x3fffffff & (int)(z2 - z);
+  return 0x3fffffff & (int)strlen(z);
+}
+
+/*
+** Return the declared type of a column.  Or return zDflt if the column 
+** has no declared type.
+**
+** The column type is an extra string stored after the zero-terminator on
+** the column name if and only if the COLFLAG_HASTYPE flag is set.
+*/
+SQLITE_PRIVATE char *sqlite3ColumnType(Column *pCol, char *zDflt){
+  if( (pCol->colFlags & COLFLAG_HASTYPE)==0 ) return zDflt;
+  return pCol->zName + strlen(pCol->zName) + 1;
+}
+
+/*
+** Helper function for sqlite3Error() - called rarely.  Broken out into
+** a separate routine to avoid unnecessary register saves on entry to
+** sqlite3Error().
+*/
+static SQLITE_NOINLINE void  sqlite3ErrorFinish(sqlite3 *db, int err_code){
+  if( db->pErr ) sqlite3ValueSetNull(db->pErr);
+  sqlite3SystemError(db, err_code);
+}
+
+/*
+** Set the current error code to err_code and clear any prior error message.
+** Also set iSysErrno (by calling sqlite3System) if the err_code indicates
+** that would be appropriate.
+*/
+SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code){
+  assert( db!=0 );
+  db->errCode = err_code;
+  if( err_code || db->pErr ) sqlite3ErrorFinish(db, err_code);
+}
+
+/*
+** Load the sqlite3.iSysErrno field if that is an appropriate thing
+** to do based on the SQLite error code in rc.
+*/
+SQLITE_PRIVATE void sqlite3SystemError(sqlite3 *db, int rc){
+  if( rc==SQLITE_IOERR_NOMEM ) return;
+  rc &= 0xff;
+  if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){
+    db->iSysErrno = sqlite3OsGetLastError(db->pVfs);
+  }
 }
 
 /*
@@ -20747,19 +27378,19 @@ SQLITE_PRIVATE int sqlite3Strlen30(const char *z){
 ** should be called with err_code set to SQLITE_OK and zFormat set
 ** to NULL.
 */
-SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
-  if( db && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
-    db->errCode = err_code;
-    if( zFormat ){
-      char *z;
-      va_list ap;
-      va_start(ap, zFormat);
-      z = sqlite3VMPrintf(db, zFormat, ap);
-      va_end(ap);
-      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
-    }else{
-      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
-    }
+SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){
+  assert( db!=0 );
+  db->errCode = err_code;
+  sqlite3SystemError(db, err_code);
+  if( zFormat==0 ){
+    sqlite3Error(db, err_code);
+  }else if( db->pErr || (db->pErr = sqlite3ValueNew(db))!=0 ){
+    char *z;
+    va_list ap;
+    va_start(ap, zFormat);
+    z = sqlite3VMPrintf(db, zFormat, ap);
+    va_end(ap);
+    sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
   }
 }
 
@@ -20773,12 +27404,12 @@ SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat,
 **      %T      Insert a token
 **      %S      Insert the first element of a SrcList
 **
-** This function should be used to report any error that occurs whilst
+** This function should be used to report any error that occurs while
 ** compiling an SQL statement (i.e. within sqlite3_prepare()). The
 ** last thing the sqlite3_prepare() function does is copy the error
 ** stored by this function into the database handle using sqlite3Error().
-** Function sqlite3Error() should be used during statement execution
-** (sqlite3_step() etc.).
+** Functions sqlite3Error() or sqlite3ErrorWithMsg() should be used
+** during statement execution (sqlite3_step() etc.).
 */
 SQLITE_PRIVATE void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
   char *zMsg;
@@ -20811,22 +27442,18 @@ SQLITE_PRIVATE void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
 ** occur.
 **
 ** 2002-Feb-14: This routine is extended to remove MS-Access style
-** brackets from around identifers.  For example:  "[a-b-c]" becomes
+** brackets from around identifiers.  For example:  "[a-b-c]" becomes
 ** "a-b-c".
 */
-SQLITE_PRIVATE int sqlite3Dequote(char *z){
+SQLITE_PRIVATE void sqlite3Dequote(char *z){
   char quote;
   int i, j;
-  if( z==0 ) return -1;
+  if( z==0 ) return;
   quote = z[0];
-  switch( quote ){
-    case '\'':  break;
-    case '"':   break;
-    case '`':   break;                /* For MySQL compatibility */
-    case '[':   quote = ']';  break;  /* For MS SqlServer compatibility */
-    default:    return -1;
-  }
-  for(i=1, j=0; ALWAYS(z[i]); i++){
+  if( !sqlite3Isquote(quote) ) return;
+  if( quote=='[' ) quote = ']';
+  for(i=1, j=0;; i++){
+    assert( z[i] );
     if( z[i]==quote ){
       if( z[i+1]==quote ){
         z[j++] = quote;
@@ -20839,7 +27466,14 @@ SQLITE_PRIVATE int sqlite3Dequote(char *z){
     }
   }
   z[j] = 0;
-  return j;
+}
+
+/*
+** Generate a Token object from a string
+*/
+SQLITE_PRIVATE void sqlite3TokenInit(Token *p, char *z){
+  p->z = z;
+  p->n = sqlite3Strlen30(z);
 }
 
 /* Convenient short-hand */
@@ -20849,21 +27483,40 @@ SQLITE_PRIVATE int sqlite3Dequote(char *z){
 ** Some systems have stricmp().  Others have strcasecmp().  Because
 ** there is no consistency, we will define our own.
 **
-** IMPLEMENTATION-OF: R-20522-24639 The sqlite3_strnicmp() API allows
-** applications and extensions to compare the contents of two buffers
-** containing UTF-8 strings in a case-independent fashion, using the same
-** definition of case independence that SQLite uses internally when
-** comparing identifiers.
+** IMPLEMENTATION-OF: R-30243-02494 The sqlite3_stricmp() and
+** sqlite3_strnicmp() APIs allow applications and extensions to compare
+** the contents of two buffers containing UTF-8 strings in a
+** case-independent fashion, using the same definition of "case
+** independence" that SQLite uses internally when comparing identifiers.
 */
+SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *zLeft, const char *zRight){
+  if( zLeft==0 ){
+    return zRight ? -1 : 0;
+  }else if( zRight==0 ){
+    return 1;
+  }
+  return sqlite3StrICmp(zLeft, zRight);
+}
 SQLITE_PRIVATE int sqlite3StrICmp(const char *zLeft, const char *zRight){
-  register unsigned char *a, *b;
+  unsigned char *a, *b;
+  int c;
   a = (unsigned char *)zLeft;
   b = (unsigned char *)zRight;
-  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
-  return UpperToLower[*a] - UpperToLower[*b];
+  for(;;){
+    c = (int)UpperToLower[*a] - (int)UpperToLower[*b];
+    if( c || *a==0 ) break;
+    a++;
+    b++;
+  }
+  return c;
 }
-SQLITE_API int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
+SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
   register unsigned char *a, *b;
+  if( zLeft==0 ){
+    return zRight ? -1 : 0;
+  }else if( zRight==0 ){
+    return 1;
+  }
   a = (unsigned char *)zLeft;
   b = (unsigned char *)zRight;
   while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
@@ -20894,7 +27547,7 @@ SQLITE_API int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
 */
 SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
 #ifndef SQLITE_OMIT_FLOATING_POINT
-  int incr = (enc==SQLITE_UTF8?1:2);
+  int incr;
   const char *zEnd = z + length;
   /* sign * significand * (10 ^ (esign * exponent)) */
   int sign = 1;    /* sign of significand */
@@ -20905,10 +27558,22 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   int eValid = 1;  /* True exponent is either not used or is well-formed */
   double result;
   int nDigits = 0;
+  int nonNum = 0;  /* True if input contains UTF16 with high byte non-zero */
 
+  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
   *pResult = 0.0;   /* Default return value, in case of an error */
 
-  if( enc==SQLITE_UTF16BE ) z++;
+  if( enc==SQLITE_UTF8 ){
+    incr = 1;
+  }else{
+    int i;
+    incr = 2;
+    assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
+    for(i=3-enc; i<length && z[i]==0; i+=2){}
+    nonNum = i<length;
+    zEnd = &z[i^1];
+    z += (enc&1);
+  }
 
   /* skip leading spaces */
   while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
@@ -20922,9 +27587,6 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
     z+=incr;
   }
 
-  /* skip leading zeroes */
-  while( z<zEnd && z[0]=='0' ) z+=incr, nDigits++;
-
   /* copy max significant digits to significand */
   while( z<zEnd && sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
     s = s*10 + (*z - '0');
@@ -20941,12 +27603,13 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
     z+=incr;
     /* copy digits from after decimal to significand
     ** (decrease exponent by d to shift decimal right) */
-    while( z<zEnd && sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
-      s = s*10 + (*z - '0');
-      z+=incr, nDigits++, d--;
+    while( z<zEnd && sqlite3Isdigit(*z) ){
+      if( s<((LARGEST_INT64-9)/10) ){
+        s = s*10 + (*z - '0');
+        d--;
+      }
+      z+=incr, nDigits++;
     }
-    /* skip non-significant digits */
-    while( z<zEnd && sqlite3Isdigit(*z) ) z+=incr, nDigits++;
   }
   if( z>=zEnd ) goto do_atof_calc;
 
@@ -20954,7 +27617,12 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   if( *z=='e' || *z=='E' ){
     z+=incr;
     eValid = 0;
-    if( z>=zEnd ) goto do_atof_calc;
+
+    /* This branch is needed to avoid a (harmless) buffer overread.  The 
+    ** special comment alerts the mutation tester that the correct answer
+    ** is obtained even if the branch is omitted */
+    if( z>=zEnd ) goto do_atof_calc;              /*PREVENTS-HARMLESS-OVERREAD*/
+
     /* get sign of exponent */
     if( *z=='-' ){
       esign = -1;
@@ -20971,9 +27639,7 @@ SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 en
   }
 
   /* skip trailing spaces */
-  if( nDigits && eValid ){
-    while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
-  }
+  while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
 
 do_atof_calc:
   /* adjust exponent by d, and update sign */
@@ -20985,41 +27651,51 @@ do_atof_calc:
     esign = 1;
   }
 
-  /* if 0 significand */
-  if( !s ) {
-    /* In the IEEE 754 standard, zero is signed.
-    ** Add the sign if we've seen at least one digit */
-    result = (sign<0 && nDigits) ? -(double)0 : (double)0;
+  if( s==0 ) {
+    /* In the IEEE 754 standard, zero is signed. */
+    result = sign<0 ? -(double)0 : (double)0;
   } else {
-    /* attempt to reduce exponent */
-    if( esign>0 ){
-      while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
-    }else{
-      while( !(s%10) && e>0 ) e--,s/=10;
+    /* Attempt to reduce exponent.
+    **
+    ** Branches that are not required for the correct answer but which only
+    ** help to obtain the correct answer faster are marked with special
+    ** comments, as a hint to the mutation tester.
+    */
+    while( e>0 ){                                       /*OPTIMIZATION-IF-TRUE*/
+      if( esign>0 ){
+        if( s>=(LARGEST_INT64/10) ) break;             /*OPTIMIZATION-IF-FALSE*/
+        s *= 10;
+      }else{
+        if( s%10!=0 ) break;                           /*OPTIMIZATION-IF-FALSE*/
+        s /= 10;
+      }
+      e--;
     }
 
     /* adjust the sign of significand */
     s = sign<0 ? -s : s;
 
-    /* if exponent, scale significand as appropriate
-    ** and store in result. */
-    if( e ){
-      double scale = 1.0;
+    if( e==0 ){                                         /*OPTIMIZATION-IF-TRUE*/
+      result = (double)s;
+    }else{
+      LONGDOUBLE_TYPE scale = 1.0;
       /* attempt to handle extremely small/large numbers better */
-      if( e>307 && e<342 ){
-        while( e%308 ) { scale *= 1.0e+1; e -= 1; }
-        if( esign<0 ){
-          result = s / scale;
-          result /= 1.0e+308;
-        }else{
-          result = s * scale;
-          result *= 1.0e+308;
-        }
-      }else if( e>=342 ){
-        if( esign<0 ){
-          result = 0.0*s;
-        }else{
-          result = 1e308*1e308*s;  /* Infinity */
+      if( e>307 ){                                      /*OPTIMIZATION-IF-TRUE*/
+        if( e<342 ){                                    /*OPTIMIZATION-IF-TRUE*/
+          while( e%308 ) { scale *= 1.0e+1; e -= 1; }
+          if( esign<0 ){
+            result = s / scale;
+            result /= 1.0e+308;
+          }else{
+            result = s * scale;
+            result *= 1.0e+308;
+          }
+        }else{ assert( e>=342 );
+          if( esign<0 ){
+            result = 0.0*s;
+          }else{
+            result = 1e308*1e308*s;  /* Infinity */
+          }
         }
       }else{
         /* 1.0e+22 is the largest power of 10 than can be 
@@ -21032,8 +27708,6 @@ do_atof_calc:
           result = s * scale;
         }
       }
-    } else {
-      result = (double)s;
     }
   }
 
@@ -21041,7 +27715,7 @@ do_atof_calc:
   *pResult = result;
 
   /* return true if number and no extra non-whitespace chracters after */
-  return z>=zEnd && nDigits>0 && eValid;
+  return z==zEnd && nDigits>0 && eValid && nonNum==0;
 #else
   return !sqlite3Atoi64(z, pResult, length, enc);
 #endif /* SQLITE_OMIT_FLOATING_POINT */
@@ -21078,33 +27752,45 @@ static int compare2pow63(const char *zNum, int incr){
   return c;
 }
 
-
 /*
-** Convert zNum to a 64-bit signed integer.
+** Convert zNum to a 64-bit signed integer.  zNum must be decimal. This
+** routine does *not* accept hexadecimal notation.
 **
 ** If the zNum value is representable as a 64-bit twos-complement 
 ** integer, then write that value into *pNum and return 0.
 **
-** If zNum is exactly 9223372036854665808, return 2.  This special
-** case is broken out because while 9223372036854665808 cannot be a 
-** signed 64-bit integer, its negative -9223372036854665808 can be.
+** If zNum is exactly 9223372036854775808, return 2.  This special
+** case is broken out because while 9223372036854775808 cannot be a 
+** signed 64-bit integer, its negative -9223372036854775808 can be.
 **
 ** If zNum is too big for a 64-bit integer and is not
-** 9223372036854665808 then return 1.
+** 9223372036854775808  or if zNum contains any non-numeric text,
+** then return 1.
 **
 ** length is the number of bytes in the string (bytes, not characters).
 ** The string is not necessarily zero-terminated.  The encoding is
 ** given by enc.
 */
 SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
-  int incr = (enc==SQLITE_UTF8?1:2);
+  int incr;
   u64 u = 0;
   int neg = 0; /* assume positive */
   int i;
   int c = 0;
+  int nonNum = 0;  /* True if input contains UTF16 with high byte non-zero */
   const char *zStart;
   const char *zEnd = zNum + length;
-  if( enc==SQLITE_UTF16BE ) zNum++;
+  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
+  if( enc==SQLITE_UTF8 ){
+    incr = 1;
+  }else{
+    incr = 2;
+    assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
+    for(i=3-enc; i<length && zNum[i]==0; i+=2){}
+    nonNum = i<length;
+    zEnd = &zNum[i^1];
+    zNum += (enc&1);
+  }
   while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr;
   if( zNum<zEnd ){
     if( *zNum=='-' ){
@@ -21120,7 +27806,7 @@ SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc
     u = u*10 + c - '0';
   }
   if( u>LARGEST_INT64 ){
-    *pNum = SMALLEST_INT64;
+    *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64;
   }else if( neg ){
     *pNum = -(i64)u;
   }else{
@@ -21129,7 +27815,11 @@ SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc
   testcase( i==18 );
   testcase( i==19 );
   testcase( i==20 );
-  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr ){
+  if( &zNum[i]<zEnd              /* Extra bytes at the end */
+   || (i==0 && zStart==zNum)     /* No digits */
+   || i>19*incr                  /* Too many digits */
+   || nonNum                     /* UTF16 with high-order bytes non-zero */
+  ){
     /* zNum is empty or contains non-numeric text or is longer
     ** than 19 digits (thus guaranteeing that it is too large) */
     return 1;
@@ -21151,16 +27841,48 @@ SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc
       /* zNum is exactly 9223372036854775808.  Fits if negative.  The
       ** special case 2 overflow if positive */
       assert( u-1==LARGEST_INT64 );
-      assert( (*pNum)==SMALLEST_INT64 );
       return neg ? 0 : 2;
     }
   }
 }
 
 /*
+** Transform a UTF-8 integer literal, in either decimal or hexadecimal,
+** into a 64-bit signed integer.  This routine accepts hexadecimal literals,
+** whereas sqlite3Atoi64() does not.
+**
+** Returns:
+**
+**     0    Successful transformation.  Fits in a 64-bit signed integer.
+**     1    Integer too large for a 64-bit signed integer or is malformed
+**     2    Special case of 9223372036854775808
+*/
+SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char *z, i64 *pOut){
+#ifndef SQLITE_OMIT_HEX_INTEGER
+  if( z[0]=='0'
+   && (z[1]=='x' || z[1]=='X')
+  ){
+    u64 u = 0;
+    int i, k;
+    for(i=2; z[i]=='0'; i++){}
+    for(k=i; sqlite3Isxdigit(z[k]); k++){
+      u = u*16 + sqlite3HexToInt(z[k]);
+    }
+    memcpy(pOut, &u, 8);
+    return (z[k]==0 && k-i<=16) ? 0 : 1;
+  }else
+#endif /* SQLITE_OMIT_HEX_INTEGER */
+  {
+    return sqlite3Atoi64(z, pOut, sqlite3Strlen30(z), SQLITE_UTF8);
+  }
+}
+
+/*
 ** If zNum represents an integer that will fit in 32-bits, then set
 ** *pValue to that integer and return true.  Otherwise return false.
 **
+** This routine accepts both decimal and hexadecimal notation for integers.
+**
 ** Any non-numeric characters that following zNum are ignored.
 ** This is different from sqlite3Atoi64() which requires the
 ** input number to be zero-terminated.
@@ -21175,6 +27897,25 @@ SQLITE_PRIVATE int sqlite3GetInt32(const char *zNum, int *pValue){
   }else if( zNum[0]=='+' ){
     zNum++;
   }
+#ifndef SQLITE_OMIT_HEX_INTEGER
+  else if( zNum[0]=='0'
+        && (zNum[1]=='x' || zNum[1]=='X')
+        && sqlite3Isxdigit(zNum[2])
+  ){
+    u32 u = 0;
+    zNum += 2;
+    while( zNum[0]=='0' ) zNum++;
+    for(i=0; sqlite3Isxdigit(zNum[i]) && i<8; i++){
+      u = u*16 + sqlite3HexToInt(zNum[i]);
+    }
+    if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){
+      memcpy(pValue, &u, 4);
+      return 1;
+    }else{
+      return 0;
+    }
+  }
+#endif
   while( zNum[0]=='0' ) zNum++;
   for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
     v = v*10 + c;
@@ -21239,7 +27980,7 @@ SQLITE_PRIVATE int sqlite3Atoi(const char *z){
 ** bit clear.  Except, if we get to the 9th byte, it stores the full
 ** 8 bits and is the last byte.
 */
-SQLITE_PRIVATE int sqlite3PutVarint(unsigned char *p, u64 v){
+static int SQLITE_NOINLINE putVarint64(unsigned char *p, u64 v){
   int i, j, n;
   u8 buf[10];
   if( v & (((u64)0xff000000)<<32) ){
@@ -21263,28 +28004,17 @@ SQLITE_PRIVATE int sqlite3PutVarint(unsigned char *p, u64 v){
   }
   return n;
 }
-
-/*
-** This routine is a faster version of sqlite3PutVarint() that only
-** works for 32-bit positive integers and which is optimized for
-** the common case of small integers.  A MACRO version, putVarint32,
-** is provided which inlines the single-byte case.  All code should use
-** the MACRO version as this function assumes the single-byte case has
-** already been handled.
-*/
-SQLITE_PRIVATE int sqlite3PutVarint32(unsigned char *p, u32 v){
-#ifndef putVarint32
-  if( (v & ~0x7f)==0 ){
-    p[0] = v;
+SQLITE_PRIVATE int sqlite3PutVarint(unsigned char *p, u64 v){
+  if( v<=0x7f ){
+    p[0] = v&0x7f;
     return 1;
   }
-#endif
-  if( (v & ~0x3fff)==0 ){
-    p[0] = (u8)((v>>7) | 0x80);
-    p[1] = (u8)(v & 0x7f);
+  if( v<=0x3fff ){
+    p[0] = ((v>>7)&0x7f)|0x80;
+    p[1] = v&0x7f;
     return 2;
   }
-  return sqlite3PutVarint(p, v);
+  return putVarint64(p,v);
 }
 
 /*
@@ -21377,7 +28107,8 @@ SQLITE_PRIVATE u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   /* a: p0<<28 | p2<<14 | p4 (unmasked) */
   if (!(a&0x80))
   {
-    /* we can skip these cause they were (effectively) done above in calc'ing s */
+    /* we can skip these cause they were (effectively) done above
+    ** while calculating s */
     /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
     /* b &= (0x7f<<14)|(0x7f); */
     b = b<<7;
@@ -21598,11 +28329,8 @@ SQLITE_PRIVATE u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){
 ** 64-bit integer.
 */
 SQLITE_PRIVATE int sqlite3VarintLen(u64 v){
-  int i = 0;
-  do{
-    i++;
-    v >>= 7;
-  }while( v!=0 && ALWAYS(i<9) );
+  int i;
+  for(i=1; (v >>= 7)!=0; i++){ assert( i<10 ); }
   return i;
 }
 
@@ -21611,13 +28339,42 @@ SQLITE_PRIVATE int sqlite3VarintLen(u64 v){
 ** Read or write a four-byte big-endian integer value.
 */
 SQLITE_PRIVATE u32 sqlite3Get4byte(const u8 *p){
-  return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+#if SQLITE_BYTEORDER==4321
+  u32 x;
+  memcpy(&x,p,4);
+  return x;
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(__GNUC__) && GCC_VERSION>=4003000
+  u32 x;
+  memcpy(&x,p,4);
+  return __builtin_bswap32(x);
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(_MSC_VER) && _MSC_VER>=1300
+  u32 x;
+  memcpy(&x,p,4);
+  return _byteswap_ulong(x);
+#else
+  testcase( p[0]&0x80 );
+  return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
+#endif
 }
 SQLITE_PRIVATE void sqlite3Put4byte(unsigned char *p, u32 v){
+#if SQLITE_BYTEORDER==4321
+  memcpy(p,&v,4);
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(__GNUC__) && GCC_VERSION>=4003000
+  u32 x = __builtin_bswap32(v);
+  memcpy(p,&x,4);
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(_MSC_VER) && _MSC_VER>=1300
+  u32 x = _byteswap_ulong(v);
+  memcpy(p,&x,4);
+#else
   p[0] = (u8)(v>>24);
   p[1] = (u8)(v>>16);
   p[2] = (u8)(v>>8);
   p[3] = (u8)v;
+#endif
 }
 
 
@@ -21649,7 +28406,7 @@ SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){
   char *zBlob;
   int i;
 
-  zBlob = (char *)sqlite3DbMallocRaw(db, n/2 + 1);
+  zBlob = (char *)sqlite3DbMallocRawNN(db, n/2 + 1);
   n--;
   if( zBlob ){
     for(i=0; i<n; i+=2){
@@ -21732,13 +28489,12 @@ SQLITE_PRIVATE int sqlite3AddInt64(i64 *pA, i64 iB){
     testcase( iA>0 && LARGEST_INT64 - iA == iB );
     testcase( iA>0 && LARGEST_INT64 - iA == iB - 1 );
     if( iA>0 && LARGEST_INT64 - iA < iB ) return 1;
-    *pA += iB;
   }else{
     testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 1 );
     testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 2 );
     if( iA<0 && -(iA + LARGEST_INT64) > iB + 1 ) return 1;
-    *pA += iB;
   }
+  *pA += iB;
   return 0; 
 }
 SQLITE_PRIVATE int sqlite3SubInt64(i64 *pA, i64 iB){
@@ -21762,9 +28518,18 @@ SQLITE_PRIVATE int sqlite3MulInt64(i64 *pA, i64 iB){
   iA0 = iA % TWOPOWER32;
   iB1 = iB/TWOPOWER32;
   iB0 = iB % TWOPOWER32;
-  if( iA1*iB1 != 0 ) return 1;
-  assert( iA1*iB0==0 || iA0*iB1==0 );
-  r = iA1*iB0 + iA0*iB1;
+  if( iA1==0 ){
+    if( iB1==0 ){
+      *pA *= iB;
+      return 0;
+    }
+    r = iA0*iB1;
+  }else if( iB1==0 ){
+    r = iA1*iB0;
+  }else{
+    /* If both iA1 and iB1 are non-zero, overflow will result */
+    return 1;
+  }
   testcase( r==(-TWOPOWER31)-1 );
   testcase( r==(-TWOPOWER31) );
   testcase( r==TWOPOWER31 );
@@ -21802,21 +28567,110 @@ SQLITE_PRIVATE int sqlite3AbsInt32(int x){
 **     test.db-journal    =>   test.nal
 **     test.db-wal        =>   test.wal
 **     test.db-shm        =>   test.shm
+**     test.db-mj7f3319fa =>   test.9fa
 */
 SQLITE_PRIVATE void sqlite3FileSuffix3(const char *zBaseFilename, char *z){
 #if SQLITE_ENABLE_8_3_NAMES<2
-  const char *zOk;
-  zOk = sqlite3_uri_parameter(zBaseFilename, "8_3_names");
-  if( zOk && sqlite3GetBoolean(zOk) )
+  if( sqlite3_uri_boolean(zBaseFilename, "8_3_names", 0) )
 #endif
   {
     int i, sz;
     sz = sqlite3Strlen30(z);
     for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
-    if( z[i]=='.' && ALWAYS(sz>i+4) ) memcpy(&z[i+1], &z[sz-3], 4);
+    if( z[i]=='.' && ALWAYS(sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);
+  }
+}
+#endif
+
+/* 
+** Find (an approximate) sum of two LogEst values.  This computation is
+** not a simple "+" operator because LogEst is stored as a logarithmic
+** value.
+** 
+*/
+SQLITE_PRIVATE LogEst sqlite3LogEstAdd(LogEst a, LogEst b){
+  static const unsigned char x[] = {
+     10, 10,                         /* 0,1 */
+      9, 9,                          /* 2,3 */
+      8, 8,                          /* 4,5 */
+      7, 7, 7,                       /* 6,7,8 */
+      6, 6, 6,                       /* 9,10,11 */
+      5, 5, 5,                       /* 12-14 */
+      4, 4, 4, 4,                    /* 15-18 */
+      3, 3, 3, 3, 3, 3,              /* 19-24 */
+      2, 2, 2, 2, 2, 2, 2,           /* 25-31 */
+  };
+  if( a>=b ){
+    if( a>b+49 ) return a;
+    if( a>b+31 ) return a+1;
+    return a+x[a-b];
+  }else{
+    if( b>a+49 ) return b;
+    if( b>a+31 ) return b+1;
+    return b+x[b-a];
   }
 }
+
+/*
+** Convert an integer into a LogEst.  In other words, compute an
+** approximation for 10*log2(x).
+*/
+SQLITE_PRIVATE LogEst sqlite3LogEst(u64 x){
+  static LogEst a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };
+  LogEst y = 40;
+  if( x<8 ){
+    if( x<2 ) return 0;
+    while( x<8 ){  y -= 10; x <<= 1; }
+  }else{
+    while( x>255 ){ y += 40; x >>= 4; }  /*OPTIMIZATION-IF-TRUE*/
+    while( x>15 ){  y += 10; x >>= 1; }
+  }
+  return a[x&7] + y - 10;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Convert a double into a LogEst
+** In other words, compute an approximation for 10*log2(x).
+*/
+SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double x){
+  u64 a;
+  LogEst e;
+  assert( sizeof(x)==8 && sizeof(a)==8 );
+  if( x<=1 ) return 0;
+  if( x<=2000000000 ) return sqlite3LogEst((u64)x);
+  memcpy(&a, &x, 8);
+  e = (a>>52) - 1022;
+  return e*10;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
+/*
+** Convert a LogEst into an integer.
+**
+** Note that this routine is only used when one or more of various
+** non-standard compile-time options is enabled.
+*/
+SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst x){
+  u64 n;
+  n = x%10;
+  x /= 10;
+  if( n>=5 ) n -= 2;
+  else if( n>=1 ) n -= 1;
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \
+    defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
+  if( x>60 ) return (u64)LARGEST_INT64;
+#else
+  /* If only SQLITE_ENABLE_STAT3_OR_STAT4 is on, then the largest input
+  ** possible to this routine is 310, resulting in a maximum x of 31 */
+  assert( x<=60 );
 #endif
+  return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x);
+}
+#endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */
 
 /************** End of util.c ************************************************/
 /************** Begin file hash.c ********************************************/
@@ -21834,6 +28688,7 @@ SQLITE_PRIVATE void sqlite3FileSuffix3(const char *zBaseFilename, char *z){
 ** This is the implementation of generic hash-tables
 ** used in SQLite.
 */
+/* #include "sqliteInt.h" */
 /* #include <assert.h> */
 
 /* Turn bulk memory into a hash table object by initializing the
@@ -21873,12 +28728,11 @@ SQLITE_PRIVATE void sqlite3HashClear(Hash *pH){
 /*
 ** The hashing function.
 */
-static unsigned int strHash(const char *z, int nKey){
-  int h = 0;
-  assert( nKey>=0 );
-  while( nKey > 0  ){
-    h = (h<<3) ^ h ^ sqlite3UpperToLower[(unsigned char)*z++];
-    nKey--;
+static unsigned int strHash(const char *z){
+  unsigned int h = 0;
+  unsigned char c;
+  while( (c = (unsigned char)*z++)!=0 ){     /*OPTIMIZATION-IF-TRUE*/
+    h = (h<<3) ^ h ^ sqlite3UpperToLower[c];
   }
   return h;
 }
@@ -21934,7 +28788,11 @@ static int rehash(Hash *pH, unsigned int new_size){
 
   /* The inability to allocates space for a larger hash table is
   ** a performance hit but it is not a fatal error.  So mark the
-  ** allocation as a benign.
+  ** allocation as a benign. Use sqlite3Malloc()/memset(0) instead of 
+  ** sqlite3MallocZero() to make the allocation, as sqlite3MallocZero()
+  ** only zeroes the requested number of bytes whereas this module will
+  ** use the actual amount of space allocated for the hash table (which
+  ** may be larger than the requested amount).
   */
   sqlite3BeginBenignMalloc();
   new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );
@@ -21946,7 +28804,7 @@ static int rehash(Hash *pH, unsigned int new_size){
   pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);
   memset(new_ht, 0, new_size*sizeof(struct _ht));
   for(elem=pH->first, pH->first=0; elem; elem = next_elem){
-    unsigned int h = strHash(elem->pKey, elem->nKey) % new_size;
+    unsigned int h = strHash(elem->pKey) % new_size;
     next_elem = elem->next;
     insertElement(pH, &new_ht[h], elem);
   }
@@ -21954,28 +28812,33 @@ static int rehash(Hash *pH, unsigned int new_size){
 }
 
 /* This function (for internal use only) locates an element in an
-** hash table that matches the given key.  The hash for this key has
-** already been computed and is passed as the 4th parameter.
+** hash table that matches the given key.  The hash for this key is
+** also computed and returned in the *pH parameter.
 */
-static HashElem *findElementGivenHash(
+static HashElem *findElementWithHash(
   const Hash *pH,     /* The pH to be searched */
   const char *pKey,   /* The key we are searching for */
-  int nKey,           /* Bytes in key (not counting zero terminator) */
-  unsigned int h      /* The hash for this key. */
+  unsigned int *pHash /* Write the hash value here */
 ){
   HashElem *elem;                /* Used to loop thru the element list */
   int count;                     /* Number of elements left to test */
+  unsigned int h;                /* The computed hash */
 
-  if( pH->ht ){
-    struct _ht *pEntry = &pH->ht[h];
+  if( pH->ht ){   /*OPTIMIZATION-IF-TRUE*/
+    struct _ht *pEntry;
+    h = strHash(pKey) % pH->htsize;
+    pEntry = &pH->ht[h];
     elem = pEntry->chain;
     count = pEntry->count;
   }else{
+    h = 0;
     elem = pH->first;
     count = pH->count;
   }
-  while( count-- && ALWAYS(elem) ){
-    if( elem->nKey==nKey && sqlite3StrNICmp(elem->pKey,pKey,nKey)==0 ){ 
+  *pHash = h;
+  while( count-- ){
+    assert( elem!=0 );
+    if( sqlite3StrICmp(elem->pKey,pKey)==0 ){ 
       return elem;
     }
     elem = elem->next;
@@ -22010,7 +28873,7 @@ static void removeElementGivenHash(
   }
   sqlite3_free( elem );
   pH->count--;
-  if( pH->count<=0 ){
+  if( pH->count==0 ){
     assert( pH->first==0 );
     assert( pH->count==0 );
     sqlite3HashClear(pH);
@@ -22018,26 +28881,20 @@ static void removeElementGivenHash(
 }
 
 /* Attempt to locate an element of the hash table pH with a key
-** that matches pKey,nKey.  Return the data for this element if it is
+** that matches pKey.  Return the data for this element if it is
 ** found, or NULL if there is no match.
 */
-SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey){
+SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey){
   HashElem *elem;    /* The element that matches key */
   unsigned int h;    /* A hash on key */
 
   assert( pH!=0 );
   assert( pKey!=0 );
-  assert( nKey>=0 );
-  if( pH->ht ){
-    h = strHash(pKey, nKey) % pH->htsize;
-  }else{
-    h = 0;
-  }
-  elem = findElementGivenHash(pH, pKey, nKey, h);
+  elem = findElementWithHash(pH, pKey, &h);
   return elem ? elem->data : 0;
 }
 
-/* Insert an element into the hash table pH.  The key is pKey,nKey
+/* Insert an element into the hash table pH.  The key is pKey
 ** and the data is "data".
 **
 ** If no element exists with a matching key, then a new
@@ -22051,20 +28908,14 @@ SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey)
 ** If the "data" parameter to this function is NULL, then the
 ** element corresponding to "key" is removed from the hash table.
 */
-SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
+SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, void *data){
   unsigned int h;       /* the hash of the key modulo hash table size */
   HashElem *elem;       /* Used to loop thru the element list */
   HashElem *new_elem;   /* New element added to the pH */
 
   assert( pH!=0 );
   assert( pKey!=0 );
-  assert( nKey>=0 );
-  if( pH->htsize ){
-    h = strHash(pKey, nKey) % pH->htsize;
-  }else{
-    h = 0;
-  }
-  elem = findElementGivenHash(pH,pKey,nKey,h);
+  elem = findElementWithHash(pH,pKey,&h);
   if( elem ){
     void *old_data = elem->data;
     if( data==0 ){
@@ -22072,7 +28923,6 @@ SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, voi
     }else{
       elem->data = data;
       elem->pKey = pKey;
-      assert(nKey==elem->nKey);
     }
     return old_data;
   }
@@ -22080,2320 +28930,200 @@ SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, voi
   new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
   if( new_elem==0 ) return data;
   new_elem->pKey = pKey;
-  new_elem->nKey = nKey;
   new_elem->data = data;
   pH->count++;
   if( pH->count>=10 && pH->count > 2*pH->htsize ){
     if( rehash(pH, pH->count*2) ){
       assert( pH->htsize>0 );
-      h = strHash(pKey, nKey) % pH->htsize;
+      h = strHash(pKey) % pH->htsize;
     }
   }
-  if( pH->ht ){
-    insertElement(pH, &pH->ht[h], new_elem);
-  }else{
-    insertElement(pH, 0, new_elem);
-  }
+  insertElement(pH, pH->ht ? &pH->ht[h] : 0, new_elem);
   return 0;
 }
 
 /************** End of hash.c ************************************************/
 /************** Begin file opcodes.c *****************************************/
 /* Automatically generated.  Do not edit */
-/* See the mkopcodec.awk script for details. */
-#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+/* See the tool/mkopcodec.tcl script for details. */
+#if !defined(SQLITE_OMIT_EXPLAIN) \
+ || defined(VDBE_PROFILE) \
+ || defined(SQLITE_DEBUG)
+#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) || defined(SQLITE_DEBUG)
+# define OpHelp(X) "\0" X
+#else
+# define OpHelp(X)
+#endif
 SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){
- static const char *const azName[] = { "?",
-     /*   1 */ "Goto",
-     /*   2 */ "Gosub",
-     /*   3 */ "Return",
-     /*   4 */ "Yield",
-     /*   5 */ "HaltIfNull",
-     /*   6 */ "Halt",
-     /*   7 */ "Integer",
-     /*   8 */ "Int64",
-     /*   9 */ "String",
-     /*  10 */ "Null",
-     /*  11 */ "Blob",
-     /*  12 */ "Variable",
-     /*  13 */ "Move",
-     /*  14 */ "Copy",
-     /*  15 */ "SCopy",
-     /*  16 */ "ResultRow",
-     /*  17 */ "CollSeq",
-     /*  18 */ "Function",
-     /*  19 */ "Not",
-     /*  20 */ "AddImm",
-     /*  21 */ "MustBeInt",
-     /*  22 */ "RealAffinity",
-     /*  23 */ "Permutation",
-     /*  24 */ "Compare",
-     /*  25 */ "Jump",
-     /*  26 */ "Once",
-     /*  27 */ "If",
-     /*  28 */ "IfNot",
-     /*  29 */ "Column",
-     /*  30 */ "Affinity",
-     /*  31 */ "MakeRecord",
-     /*  32 */ "Count",
-     /*  33 */ "Savepoint",
-     /*  34 */ "AutoCommit",
-     /*  35 */ "Transaction",
-     /*  36 */ "ReadCookie",
-     /*  37 */ "SetCookie",
-     /*  38 */ "VerifyCookie",
-     /*  39 */ "OpenRead",
-     /*  40 */ "OpenWrite",
-     /*  41 */ "OpenAutoindex",
-     /*  42 */ "OpenEphemeral",
-     /*  43 */ "SorterOpen",
-     /*  44 */ "OpenPseudo",
-     /*  45 */ "Close",
-     /*  46 */ "SeekLt",
-     /*  47 */ "SeekLe",
-     /*  48 */ "SeekGe",
-     /*  49 */ "SeekGt",
-     /*  50 */ "Seek",
-     /*  51 */ "NotFound",
-     /*  52 */ "Found",
-     /*  53 */ "IsUnique",
-     /*  54 */ "NotExists",
-     /*  55 */ "Sequence",
-     /*  56 */ "NewRowid",
-     /*  57 */ "Insert",
-     /*  58 */ "InsertInt",
-     /*  59 */ "Delete",
-     /*  60 */ "ResetCount",
-     /*  61 */ "SorterCompare",
-     /*  62 */ "SorterData",
-     /*  63 */ "RowKey",
-     /*  64 */ "RowData",
-     /*  65 */ "Rowid",
-     /*  66 */ "NullRow",
-     /*  67 */ "Last",
-     /*  68 */ "Or",
-     /*  69 */ "And",
-     /*  70 */ "SorterSort",
-     /*  71 */ "Sort",
-     /*  72 */ "Rewind",
-     /*  73 */ "IsNull",
-     /*  74 */ "NotNull",
-     /*  75 */ "Ne",
-     /*  76 */ "Eq",
-     /*  77 */ "Gt",
-     /*  78 */ "Le",
-     /*  79 */ "Lt",
-     /*  80 */ "Ge",
-     /*  81 */ "SorterNext",
-     /*  82 */ "BitAnd",
-     /*  83 */ "BitOr",
-     /*  84 */ "ShiftLeft",
-     /*  85 */ "ShiftRight",
-     /*  86 */ "Add",
-     /*  87 */ "Subtract",
-     /*  88 */ "Multiply",
-     /*  89 */ "Divide",
-     /*  90 */ "Remainder",
-     /*  91 */ "Concat",
-     /*  92 */ "Prev",
-     /*  93 */ "BitNot",
-     /*  94 */ "String8",
-     /*  95 */ "Next",
-     /*  96 */ "SorterInsert",
-     /*  97 */ "IdxInsert",
-     /*  98 */ "IdxDelete",
-     /*  99 */ "IdxRowid",
-     /* 100 */ "IdxLT",
-     /* 101 */ "IdxGE",
-     /* 102 */ "Destroy",
-     /* 103 */ "Clear",
-     /* 104 */ "CreateIndex",
-     /* 105 */ "CreateTable",
-     /* 106 */ "ParseSchema",
-     /* 107 */ "LoadAnalysis",
-     /* 108 */ "DropTable",
-     /* 109 */ "DropIndex",
-     /* 110 */ "DropTrigger",
-     /* 111 */ "IntegrityCk",
-     /* 112 */ "RowSetAdd",
-     /* 113 */ "RowSetRead",
-     /* 114 */ "RowSetTest",
-     /* 115 */ "Program",
-     /* 116 */ "Param",
-     /* 117 */ "FkCounter",
-     /* 118 */ "FkIfZero",
-     /* 119 */ "MemMax",
-     /* 120 */ "IfPos",
-     /* 121 */ "IfNeg",
-     /* 122 */ "IfZero",
-     /* 123 */ "AggStep",
-     /* 124 */ "AggFinal",
-     /* 125 */ "Checkpoint",
-     /* 126 */ "JournalMode",
-     /* 127 */ "Vacuum",
-     /* 128 */ "IncrVacuum",
-     /* 129 */ "Expire",
-     /* 130 */ "Real",
-     /* 131 */ "TableLock",
-     /* 132 */ "VBegin",
-     /* 133 */ "VCreate",
-     /* 134 */ "VDestroy",
-     /* 135 */ "VOpen",
-     /* 136 */ "VFilter",
-     /* 137 */ "VColumn",
-     /* 138 */ "VNext",
-     /* 139 */ "VRename",
-     /* 140 */ "VUpdate",
-     /* 141 */ "ToText",
-     /* 142 */ "ToBlob",
-     /* 143 */ "ToNumeric",
-     /* 144 */ "ToInt",
-     /* 145 */ "ToReal",
-     /* 146 */ "Pagecount",
-     /* 147 */ "MaxPgcnt",
-     /* 148 */ "Trace",
-     /* 149 */ "Noop",
-     /* 150 */ "Explain",
+ static const char *const azName[] = {
+    /*   0 */ "Savepoint"        OpHelp(""),
+    /*   1 */ "AutoCommit"       OpHelp(""),
+    /*   2 */ "Transaction"      OpHelp(""),
+    /*   3 */ "SorterNext"       OpHelp(""),
+    /*   4 */ "PrevIfOpen"       OpHelp(""),
+    /*   5 */ "NextIfOpen"       OpHelp(""),
+    /*   6 */ "Prev"             OpHelp(""),
+    /*   7 */ "Next"             OpHelp(""),
+    /*   8 */ "Checkpoint"       OpHelp(""),
+    /*   9 */ "JournalMode"      OpHelp(""),
+    /*  10 */ "Vacuum"           OpHelp(""),
+    /*  11 */ "VFilter"          OpHelp("iplan=r[P3] zplan='P4'"),
+    /*  12 */ "VUpdate"          OpHelp("data=r[P3@P2]"),
+    /*  13 */ "Goto"             OpHelp(""),
+    /*  14 */ "Gosub"            OpHelp(""),
+    /*  15 */ "InitCoroutine"    OpHelp(""),
+    /*  16 */ "Yield"            OpHelp(""),
+    /*  17 */ "MustBeInt"        OpHelp(""),
+    /*  18 */ "Jump"             OpHelp(""),
+    /*  19 */ "Not"              OpHelp("r[P2]= !r[P1]"),
+    /*  20 */ "Once"             OpHelp(""),
+    /*  21 */ "If"               OpHelp(""),
+    /*  22 */ "IfNot"            OpHelp(""),
+    /*  23 */ "SeekLT"           OpHelp("key=r[P3@P4]"),
+    /*  24 */ "SeekLE"           OpHelp("key=r[P3@P4]"),
+    /*  25 */ "SeekGE"           OpHelp("key=r[P3@P4]"),
+    /*  26 */ "SeekGT"           OpHelp("key=r[P3@P4]"),
+    /*  27 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),
+    /*  28 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),
+    /*  29 */ "NoConflict"       OpHelp("key=r[P3@P4]"),
+    /*  30 */ "NotFound"         OpHelp("key=r[P3@P4]"),
+    /*  31 */ "Found"            OpHelp("key=r[P3@P4]"),
+    /*  32 */ "SeekRowid"        OpHelp("intkey=r[P3]"),
+    /*  33 */ "NotExists"        OpHelp("intkey=r[P3]"),
+    /*  34 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
+    /*  35 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
+    /*  36 */ "Ne"               OpHelp("if r[P1]!=r[P3] goto P2"),
+    /*  37 */ "Eq"               OpHelp("if r[P1]==r[P3] goto P2"),
+    /*  38 */ "Gt"               OpHelp("if r[P1]>r[P3] goto P2"),
+    /*  39 */ "Le"               OpHelp("if r[P1]<=r[P3] goto P2"),
+    /*  40 */ "Lt"               OpHelp("if r[P1]<r[P3] goto P2"),
+    /*  41 */ "Ge"               OpHelp("if r[P1]>=r[P3] goto P2"),
+    /*  42 */ "Last"             OpHelp(""),
+    /*  43 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
+    /*  44 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
+    /*  45 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<<r[P1]"),
+    /*  46 */ "ShiftRight"       OpHelp("r[P3]=r[P2]>>r[P1]"),
+    /*  47 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
+    /*  48 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
+    /*  49 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
+    /*  50 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
+    /*  51 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
+    /*  52 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
+    /*  53 */ "SorterSort"       OpHelp(""),
+    /*  54 */ "BitNot"           OpHelp("r[P1]= ~r[P1]"),
+    /*  55 */ "Sort"             OpHelp(""),
+    /*  56 */ "Rewind"           OpHelp(""),
+    /*  57 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
+    /*  58 */ "IdxGT"            OpHelp("key=r[P3@P4]"),
+    /*  59 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
+    /*  60 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
+    /*  61 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
+    /*  62 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
+    /*  63 */ "Program"          OpHelp(""),
+    /*  64 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
+    /*  65 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
+    /*  66 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]-=P3, goto P2"),
+    /*  67 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
+    /*  68 */ "IncrVacuum"       OpHelp(""),
+    /*  69 */ "VNext"            OpHelp(""),
+    /*  70 */ "Init"             OpHelp("Start at P2"),
+    /*  71 */ "Return"           OpHelp(""),
+    /*  72 */ "EndCoroutine"     OpHelp(""),
+    /*  73 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
+    /*  74 */ "Halt"             OpHelp(""),
+    /*  75 */ "Integer"          OpHelp("r[P2]=P1"),
+    /*  76 */ "Int64"            OpHelp("r[P2]=P4"),
+    /*  77 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
+    /*  78 */ "Null"             OpHelp("r[P2..P3]=NULL"),
+    /*  79 */ "SoftNull"         OpHelp("r[P1]=NULL"),
+    /*  80 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
+    /*  81 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),
+    /*  82 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
+    /*  83 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
+    /*  84 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
+    /*  85 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),
+    /*  86 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
+    /*  87 */ "CollSeq"          OpHelp(""),
+    /*  88 */ "Function0"        OpHelp("r[P3]=func(r[P2@P5])"),
+    /*  89 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),
+    /*  90 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
+    /*  91 */ "RealAffinity"     OpHelp(""),
+    /*  92 */ "Cast"             OpHelp("affinity(r[P1])"),
+    /*  93 */ "Permutation"      OpHelp(""),
+    /*  94 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
+    /*  95 */ "Column"           OpHelp("r[P3]=PX"),
+    /*  96 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
+    /*  97 */ "String8"          OpHelp("r[P2]='P4'"),
+    /*  98 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
+    /*  99 */ "Count"            OpHelp("r[P2]=count()"),
+    /* 100 */ "ReadCookie"       OpHelp(""),
+    /* 101 */ "SetCookie"        OpHelp(""),
+    /* 102 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),
+    /* 103 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
+    /* 104 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),
+    /* 105 */ "OpenAutoindex"    OpHelp("nColumn=P2"),
+    /* 106 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
+    /* 107 */ "SorterOpen"       OpHelp(""),
+    /* 108 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
+    /* 109 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
+    /* 110 */ "Close"            OpHelp(""),
+    /* 111 */ "ColumnsUsed"      OpHelp(""),
+    /* 112 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),
+    /* 113 */ "NewRowid"         OpHelp("r[P2]=rowid"),
+    /* 114 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
+    /* 115 */ "InsertInt"        OpHelp("intkey=P3 data=r[P2]"),
+    /* 116 */ "Delete"           OpHelp(""),
+    /* 117 */ "ResetCount"       OpHelp(""),
+    /* 118 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
+    /* 119 */ "SorterData"       OpHelp("r[P2]=data"),
+    /* 120 */ "RowKey"           OpHelp("r[P2]=key"),
+    /* 121 */ "RowData"          OpHelp("r[P2]=data"),
+    /* 122 */ "Rowid"            OpHelp("r[P2]=rowid"),
+    /* 123 */ "NullRow"          OpHelp(""),
+    /* 124 */ "SorterInsert"     OpHelp(""),
+    /* 125 */ "IdxInsert"        OpHelp("key=r[P2]"),
+    /* 126 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),
+    /* 127 */ "Seek"             OpHelp("Move P3 to P1.rowid"),
+    /* 128 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
+    /* 129 */ "Destroy"          OpHelp(""),
+    /* 130 */ "Clear"            OpHelp(""),
+    /* 131 */ "ResetSorter"      OpHelp(""),
+    /* 132 */ "CreateIndex"      OpHelp("r[P2]=root iDb=P1"),
+    /* 133 */ "Real"             OpHelp("r[P2]=P4"),
+    /* 134 */ "CreateTable"      OpHelp("r[P2]=root iDb=P1"),
+    /* 135 */ "ParseSchema"      OpHelp(""),
+    /* 136 */ "LoadAnalysis"     OpHelp(""),
+    /* 137 */ "DropTable"        OpHelp(""),
+    /* 138 */ "DropIndex"        OpHelp(""),
+    /* 139 */ "DropTrigger"      OpHelp(""),
+    /* 140 */ "IntegrityCk"      OpHelp(""),
+    /* 141 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
+    /* 142 */ "Param"            OpHelp(""),
+    /* 143 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
+    /* 144 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
+    /* 145 */ "OffsetLimit"      OpHelp("if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)"),
+    /* 146 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
+    /* 147 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
+    /* 148 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
+    /* 149 */ "Expire"           OpHelp(""),
+    /* 150 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
+    /* 151 */ "VBegin"           OpHelp(""),
+    /* 152 */ "VCreate"          OpHelp(""),
+    /* 153 */ "VDestroy"         OpHelp(""),
+    /* 154 */ "VOpen"            OpHelp(""),
+    /* 155 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
+    /* 156 */ "VRename"          OpHelp(""),
+    /* 157 */ "Pagecount"        OpHelp(""),
+    /* 158 */ "MaxPgcnt"         OpHelp(""),
+    /* 159 */ "CursorHint"       OpHelp(""),
+    /* 160 */ "Noop"             OpHelp(""),
+    /* 161 */ "Explain"          OpHelp(""),
   };
   return azName[i];
 }
 #endif
 
 /************** End of opcodes.c *********************************************/
-/************** Begin file os_os2.c ******************************************/
-/*
-** 2006 Feb 14
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-******************************************************************************
-**
-** This file contains code that is specific to OS/2.
-*/
-
-
-#if SQLITE_OS_OS2
-
-/*
-** A Note About Memory Allocation:
-**
-** This driver uses malloc()/free() directly rather than going through
-** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers
-** are designed for use on embedded systems where memory is scarce and
-** malloc failures happen frequently.  OS/2 does not typically run on
-** embedded systems, and when it does the developers normally have bigger
-** problems to worry about than running out of memory.  So there is not
-** a compelling need to use the wrappers.
-**
-** But there is a good reason to not use the wrappers.  If we use the
-** wrappers then we will get simulated malloc() failures within this
-** driver.  And that causes all kinds of problems for our tests.  We
-** could enhance SQLite to deal with simulated malloc failures within
-** the OS driver, but the code to deal with those failure would not
-** be exercised on Linux (which does not need to malloc() in the driver)
-** and so we would have difficulty writing coverage tests for that
-** code.  Better to leave the code out, we think.
-**
-** The point of this discussion is as follows:  When creating a new
-** OS layer for an embedded system, if you use this file as an example,
-** avoid the use of malloc()/free().  Those routines work ok on OS/2
-** desktops but not so well in embedded systems.
-*/
-
-/*
-** Macros used to determine whether or not to use threads.
-*/
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE
-# define SQLITE_OS2_THREADS 1
-#endif
-
-/*
-** Include code that is common to all os_*.c files
-*/
-/************** Include os_common.h in the middle of os_os2.c ****************/
-/************** Begin file os_common.h ***************************************/
-/*
-** 2004 May 22
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-******************************************************************************
-**
-** This file contains macros and a little bit of code that is common to
-** all of the platform-specific files (os_*.c) and is #included into those
-** files.
-**
-** This file should be #included by the os_*.c files only.  It is not a
-** general purpose header file.
-*/
-#ifndef _OS_COMMON_H_
-#define _OS_COMMON_H_
-
-/*
-** At least two bugs have slipped in because we changed the MEMORY_DEBUG
-** macro to SQLITE_DEBUG and some older makefiles have not yet made the
-** switch.  The following code should catch this problem at compile-time.
-*/
-#ifdef MEMORY_DEBUG
-# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
-#endif
-
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
-/*
-** Macros for performance tracing.  Normally turned off.  Only works
-** on i486 hardware.
-*/
-#ifdef SQLITE_PERFORMANCE_TRACE
-
-/* 
-** hwtime.h contains inline assembler code for implementing 
-** high-performance timing routines.
-*/
-/************** Include hwtime.h in the middle of os_common.h ****************/
-/************** Begin file hwtime.h ******************************************/
-/*
-** 2008 May 27
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-******************************************************************************
-**
-** This file contains inline asm code for retrieving "high-performance"
-** counters for x86 class CPUs.
-*/
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
-
-/*
-** The following routine only works on pentium-class (or newer) processors.
-** It uses the RDTSC opcode to read the cycle count value out of the
-** processor and returns that value.  This can be used for high-res
-** profiling.
-*/
-#if (defined(__GNUC__) || defined(_MSC_VER)) && \
-      (defined(i386) || defined(__i386__) || defined(_M_IX86))
-
-  #if defined(__GNUC__)
-
-  __inline__ sqlite_uint64 sqlite3Hwtime(void){
-     unsigned int lo, hi;
-     __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
-     return (sqlite_uint64)hi << 32 | lo;
-  }
-
-  #elif defined(_MSC_VER)
-
-  __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
-     __asm {
-        rdtsc
-        ret       ; return value at EDX:EAX
-     }
-  }
-
-  #endif
-
-#elif (defined(__GNUC__) && defined(__x86_64__))
-
-  __inline__ sqlite_uint64 sqlite3Hwtime(void){
-      unsigned long val;
-      __asm__ __volatile__ ("rdtsc" : "=A" (val));
-      return val;
-  }
- 
-#elif (defined(__GNUC__) && defined(__ppc__))
-
-  __inline__ sqlite_uint64 sqlite3Hwtime(void){
-      unsigned long long retval;
-      unsigned long junk;
-      __asm__ __volatile__ ("\n\
-          1:      mftbu   %1\n\
-                  mftb    %L0\n\
-                  mftbu   %0\n\
-                  cmpw    %0,%1\n\
-                  bne     1b"
-                  : "=r" (retval), "=r" (junk));
-      return retval;
-  }
-
-#else
-
-  #error Need implementation of sqlite3Hwtime() for your platform.
-
-  /*
-  ** To compile without implementing sqlite3Hwtime() for your platform,
-  ** you can remove the above #error and use the following
-  ** stub function.  You will lose timing support for many
-  ** of the debugging and testing utilities, but it should at
-  ** least compile and run.
-  */
-SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
-
-#endif
-
-#endif /* !defined(_HWTIME_H_) */
-
-/************** End of hwtime.h **********************************************/
-/************** Continuing where we left off in os_common.h ******************/
-
-static sqlite_uint64 g_start;
-static sqlite_uint64 g_elapsed;
-#define TIMER_START       g_start=sqlite3Hwtime()
-#define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start
-#define TIMER_ELAPSED     g_elapsed
-#else
-#define TIMER_START
-#define TIMER_END
-#define TIMER_ELAPSED     ((sqlite_uint64)0)
-#endif
-
-/*
-** If we compile with the SQLITE_TEST macro set, then the following block
-** of code will give us the ability to simulate a disk I/O error.  This
-** is used for testing the I/O recovery logic.
-*/
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
-#define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
-#define SimulateIOError(CODE)  \
-  if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
-       || sqlite3_io_error_pending-- == 1 )  \
-              { local_ioerr(); CODE; }
-static void local_ioerr(){
-  IOTRACE(("IOERR\n"));
-  sqlite3_io_error_hit++;
-  if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;
-}
-#define SimulateDiskfullError(CODE) \
-   if( sqlite3_diskfull_pending ){ \
-     if( sqlite3_diskfull_pending == 1 ){ \
-       local_ioerr(); \
-       sqlite3_diskfull = 1; \
-       sqlite3_io_error_hit = 1; \
-       CODE; \
-     }else{ \
-       sqlite3_diskfull_pending--; \
-     } \
-   }
-#else
-#define SimulateIOErrorBenign(X)
-#define SimulateIOError(A)
-#define SimulateDiskfullError(A)
-#endif
-
-/*
-** When testing, keep a count of the number of open files.
-*/
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
-#define OpenCounter(X)  sqlite3_open_file_count+=(X)
-#else
-#define OpenCounter(X)
-#endif
-
-#endif /* !defined(_OS_COMMON_H_) */
-
-/************** End of os_common.h *******************************************/
-/************** Continuing where we left off in os_os2.c *********************/
-
-/* Forward references */
-typedef struct os2File os2File;         /* The file structure */
-typedef struct os2ShmNode os2ShmNode;   /* A shared descritive memory node */
-typedef struct os2ShmLink os2ShmLink;   /* A connection to shared-memory */
-
-/*
-** The os2File structure is subclass of sqlite3_file specific for the OS/2
-** protability layer.
-*/
-struct os2File {
-  const sqlite3_io_methods *pMethod;  /* Always the first entry */
-  HFILE h;                  /* Handle for accessing the file */
-  int flags;                /* Flags provided to os2Open() */
-  int locktype;             /* Type of lock currently held on this file */
-  int szChunk;              /* Chunk size configured by FCNTL_CHUNK_SIZE */
-  char *zFullPathCp;        /* Full path name of this file */
-  os2ShmLink *pShmLink;     /* Instance of shared memory on this file */
-};
-
-#define LOCK_TIMEOUT 10L /* the default locking timeout */
-
-/*
-** Missing from some versions of the OS/2 toolkit -
-** used to allocate from high memory if possible
-*/
-#ifndef OBJ_ANY
-# define OBJ_ANY 0x00000400
-#endif
-
-/*****************************************************************************
-** The next group of routines implement the I/O methods specified
-** by the sqlite3_io_methods object.
-******************************************************************************/
-
-/*
-** Close a file.
-*/
-static int os2Close( sqlite3_file *id ){
-  APIRET rc;
-  os2File *pFile = (os2File*)id;
-
-  assert( id!=0 );
-  OSTRACE(( "CLOSE %d (%s)\n", pFile->h, pFile->zFullPathCp ));
-
-  rc = DosClose( pFile->h );
-
-  if( pFile->flags & SQLITE_OPEN_DELETEONCLOSE )
-    DosForceDelete( (PSZ)pFile->zFullPathCp );
-
-  free( pFile->zFullPathCp );
-  pFile->zFullPathCp = NULL;
-  pFile->locktype = NO_LOCK;
-  pFile->h = (HFILE)-1;
-  pFile->flags = 0;
-
-  OpenCounter( -1 );
-  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
-}
-
-/*
-** Read data from a file into a buffer.  Return SQLITE_OK if all
-** bytes were read successfully and SQLITE_IOERR if anything goes
-** wrong.
-*/
-static int os2Read(
-  sqlite3_file *id,               /* File to read from */
-  void *pBuf,                     /* Write content into this buffer */
-  int amt,                        /* Number of bytes to read */
-  sqlite3_int64 offset            /* Begin reading at this offset */
-){
-  ULONG fileLocation = 0L;
-  ULONG got;
-  os2File *pFile = (os2File*)id;
-  assert( id!=0 );
-  SimulateIOError( return SQLITE_IOERR_READ );
-  OSTRACE(( "READ %d lock=%d\n", pFile->h, pFile->locktype ));
-  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
-    return SQLITE_IOERR;
-  }
-  if( DosRead( pFile->h, pBuf, amt, &got ) != NO_ERROR ){
-    return SQLITE_IOERR_READ;
-  }
-  if( got == (ULONG)amt )
-    return SQLITE_OK;
-  else {
-    /* Unread portions of the input buffer must be zero-filled */
-    memset(&((char*)pBuf)[got], 0, amt-got);
-    return SQLITE_IOERR_SHORT_READ;
-  }
-}
-
-/*
-** Write data from a buffer into a file.  Return SQLITE_OK on success
-** or some other error code on failure.
-*/
-static int os2Write(
-  sqlite3_file *id,               /* File to write into */
-  const void *pBuf,               /* The bytes to be written */
-  int amt,                        /* Number of bytes to write */
-  sqlite3_int64 offset            /* Offset into the file to begin writing at */
-){
-  ULONG fileLocation = 0L;
-  APIRET rc = NO_ERROR;
-  ULONG wrote;
-  os2File *pFile = (os2File*)id;
-  assert( id!=0 );
-  SimulateIOError( return SQLITE_IOERR_WRITE );
-  SimulateDiskfullError( return SQLITE_FULL );
-  OSTRACE(( "WRITE %d lock=%d\n", pFile->h, pFile->locktype ));
-  if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
-    return SQLITE_IOERR;
-  }
-  assert( amt>0 );
-  while( amt > 0 &&
-         ( rc = DosWrite( pFile->h, (PVOID)pBuf, amt, &wrote ) ) == NO_ERROR &&
-         wrote > 0
-  ){
-    amt -= wrote;
-    pBuf = &((char*)pBuf)[wrote];
-  }
-
-  return ( rc != NO_ERROR || amt > (int)wrote ) ? SQLITE_FULL : SQLITE_OK;
-}
-
-/*
-** Truncate an open file to a specified size
-*/
-static int os2Truncate( sqlite3_file *id, i64 nByte ){
-  APIRET rc;
-  os2File *pFile = (os2File*)id;
-  assert( id!=0 );
-  OSTRACE(( "TRUNCATE %d %lld\n", pFile->h, nByte ));
-  SimulateIOError( return SQLITE_IOERR_TRUNCATE );
-
-  /* If the user has configured a chunk-size for this file, truncate the
-  ** file so that it consists of an integer number of chunks (i.e. the
-  ** actual file size after the operation may be larger than the requested
-  ** size).
-  */
-  if( pFile->szChunk ){
-    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
-  }
-  
-  rc = DosSetFileSize( pFile->h, nByte );
-  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR_TRUNCATE;
-}
-
-#ifdef SQLITE_TEST
-/*
-** Count the number of fullsyncs and normal syncs.  This is used to test
-** that syncs and fullsyncs are occuring at the right times.
-*/
-SQLITE_API int sqlite3_sync_count = 0;
-SQLITE_API int sqlite3_fullsync_count = 0;
-#endif
-
-/*
-** Make sure all writes to a particular file are committed to disk.
-*/
-static int os2Sync( sqlite3_file *id, int flags ){
-  os2File *pFile = (os2File*)id;
-  OSTRACE(( "SYNC %d lock=%d\n", pFile->h, pFile->locktype ));
-#ifdef SQLITE_TEST
-  if( flags & SQLITE_SYNC_FULL){
-    sqlite3_fullsync_count++;
-  }
-  sqlite3_sync_count++;
-#endif
-  /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
-  ** no-op
-  */
-#ifdef SQLITE_NO_SYNC
-  UNUSED_PARAMETER(pFile);
-  return SQLITE_OK;
-#else
-  return DosResetBuffer( pFile->h ) == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
-#endif
-}
-
-/*
-** Determine the current size of a file in bytes
-*/
-static int os2FileSize( sqlite3_file *id, sqlite3_int64 *pSize ){
-  APIRET rc = NO_ERROR;
-  FILESTATUS3 fsts3FileInfo;
-  memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
-  assert( id!=0 );
-  SimulateIOError( return SQLITE_IOERR_FSTAT );
-  rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
-  if( rc == NO_ERROR ){
-    *pSize = fsts3FileInfo.cbFile;
-    return SQLITE_OK;
-  }else{
-    return SQLITE_IOERR_FSTAT;
-  }
-}
-
-/*
-** Acquire a reader lock.
-*/
-static int getReadLock( os2File *pFile ){
-  FILELOCK  LockArea,
-            UnlockArea;
-  APIRET res;
-  memset(&LockArea, 0, sizeof(LockArea));
-  memset(&UnlockArea, 0, sizeof(UnlockArea));
-  LockArea.lOffset = SHARED_FIRST;
-  LockArea.lRange = SHARED_SIZE;
-  UnlockArea.lOffset = 0L;
-  UnlockArea.lRange = 0L;
-  res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
-  OSTRACE(( "GETREADLOCK %d res=%d\n", pFile->h, res ));
-  return res;
-}
-
-/*
-** Undo a readlock
-*/
-static int unlockReadLock( os2File *id ){
-  FILELOCK  LockArea,
-            UnlockArea;
-  APIRET res;
-  memset(&LockArea, 0, sizeof(LockArea));
-  memset(&UnlockArea, 0, sizeof(UnlockArea));
-  LockArea.lOffset = 0L;
-  LockArea.lRange = 0L;
-  UnlockArea.lOffset = SHARED_FIRST;
-  UnlockArea.lRange = SHARED_SIZE;
-  res = DosSetFileLocks( id->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
-  OSTRACE(( "UNLOCK-READLOCK file handle=%d res=%d?\n", id->h, res ));
-  return res;
-}
-
-/*
-** Lock the file with the lock specified by parameter locktype - one
-** of the following:
-**
-**     (1) SHARED_LOCK
-**     (2) RESERVED_LOCK
-**     (3) PENDING_LOCK
-**     (4) EXCLUSIVE_LOCK
-**
-** Sometimes when requesting one lock state, additional lock states
-** are inserted in between.  The locking might fail on one of the later
-** transitions leaving the lock state different from what it started but
-** still short of its goal.  The following chart shows the allowed
-** transitions and the inserted intermediate states:
-**
-**    UNLOCKED -> SHARED
-**    SHARED -> RESERVED
-**    SHARED -> (PENDING) -> EXCLUSIVE
-**    RESERVED -> (PENDING) -> EXCLUSIVE
-**    PENDING -> EXCLUSIVE
-**
-** This routine will only increase a lock.  The os2Unlock() routine
-** erases all locks at once and returns us immediately to locking level 0.
-** It is not possible to lower the locking level one step at a time.  You
-** must go straight to locking level 0.
-*/
-static int os2Lock( sqlite3_file *id, int locktype ){
-  int rc = SQLITE_OK;       /* Return code from subroutines */
-  APIRET res = NO_ERROR;    /* Result of an OS/2 lock call */
-  int newLocktype;       /* Set pFile->locktype to this value before exiting */
-  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
-  FILELOCK  LockArea,
-            UnlockArea;
-  os2File *pFile = (os2File*)id;
-  memset(&LockArea, 0, sizeof(LockArea));
-  memset(&UnlockArea, 0, sizeof(UnlockArea));
-  assert( pFile!=0 );
-  OSTRACE(( "LOCK %d %d was %d\n", pFile->h, locktype, pFile->locktype ));
-
-  /* If there is already a lock of this type or more restrictive on the
-  ** os2File, do nothing. Don't use the end_lock: exit path, as
-  ** sqlite3_mutex_enter() hasn't been called yet.
-  */
-  if( pFile->locktype>=locktype ){
-    OSTRACE(( "LOCK %d %d ok (already held)\n", pFile->h, locktype ));
-    return SQLITE_OK;
-  }
-
-  /* Make sure the locking sequence is correct
-  */
-  assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
-  assert( locktype!=PENDING_LOCK );
-  assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
-
-  /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
-  ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
-  ** the PENDING_LOCK byte is temporary.
-  */
-  newLocktype = pFile->locktype;
-  if( pFile->locktype==NO_LOCK
-      || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
-  ){
-    LockArea.lOffset = PENDING_BYTE;
-    LockArea.lRange = 1L;
-    UnlockArea.lOffset = 0L;
-    UnlockArea.lRange = 0L;
-
-    /* wait longer than LOCK_TIMEOUT here not to have to try multiple times */
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 100L, 0L );
-    if( res == NO_ERROR ){
-      gotPendingLock = 1;
-      OSTRACE(( "LOCK %d pending lock boolean set.  res=%d\n", pFile->h, res ));
-    }
-  }
-
-  /* Acquire a shared lock
-  */
-  if( locktype==SHARED_LOCK && res == NO_ERROR ){
-    assert( pFile->locktype==NO_LOCK );
-    res = getReadLock(pFile);
-    if( res == NO_ERROR ){
-      newLocktype = SHARED_LOCK;
-    }
-    OSTRACE(( "LOCK %d acquire shared lock. res=%d\n", pFile->h, res ));
-  }
-
-  /* Acquire a RESERVED lock
-  */
-  if( locktype==RESERVED_LOCK && res == NO_ERROR ){
-    assert( pFile->locktype==SHARED_LOCK );
-    LockArea.lOffset = RESERVED_BYTE;
-    LockArea.lRange = 1L;
-    UnlockArea.lOffset = 0L;
-    UnlockArea.lRange = 0L;
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    if( res == NO_ERROR ){
-      newLocktype = RESERVED_LOCK;
-    }
-    OSTRACE(( "LOCK %d acquire reserved lock. res=%d\n", pFile->h, res ));
-  }
-
-  /* Acquire a PENDING lock
-  */
-  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
-    newLocktype = PENDING_LOCK;
-    gotPendingLock = 0;
-    OSTRACE(( "LOCK %d acquire pending lock. pending lock boolean unset.\n",
-               pFile->h ));
-  }
-
-  /* Acquire an EXCLUSIVE lock
-  */
-  if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
-    assert( pFile->locktype>=SHARED_LOCK );
-    res = unlockReadLock(pFile);
-    OSTRACE(( "unreadlock = %d\n", res ));
-    LockArea.lOffset = SHARED_FIRST;
-    LockArea.lRange = SHARED_SIZE;
-    UnlockArea.lOffset = 0L;
-    UnlockArea.lRange = 0L;
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    if( res == NO_ERROR ){
-      newLocktype = EXCLUSIVE_LOCK;
-    }else{
-      OSTRACE(( "OS/2 error-code = %d\n", res ));
-      getReadLock(pFile);
-    }
-    OSTRACE(( "LOCK %d acquire exclusive lock.  res=%d\n", pFile->h, res ));
-  }
-
-  /* If we are holding a PENDING lock that ought to be released, then
-  ** release it now.
-  */
-  if( gotPendingLock && locktype==SHARED_LOCK ){
-    int r;
-    LockArea.lOffset = 0L;
-    LockArea.lRange = 0L;
-    UnlockArea.lOffset = PENDING_BYTE;
-    UnlockArea.lRange = 1L;
-    r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    OSTRACE(( "LOCK %d unlocking pending/is shared. r=%d\n", pFile->h, r ));
-  }
-
-  /* Update the state of the lock has held in the file descriptor then
-  ** return the appropriate result code.
-  */
-  if( res == NO_ERROR ){
-    rc = SQLITE_OK;
-  }else{
-    OSTRACE(( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
-              locktype, newLocktype ));
-    rc = SQLITE_BUSY;
-  }
-  pFile->locktype = newLocktype;
-  OSTRACE(( "LOCK %d now %d\n", pFile->h, pFile->locktype ));
-  return rc;
-}
-
-/*
-** This routine checks if there is a RESERVED lock held on the specified
-** file by this or any other process. If such a lock is held, return
-** non-zero, otherwise zero.
-*/
-static int os2CheckReservedLock( sqlite3_file *id, int *pOut ){
-  int r = 0;
-  os2File *pFile = (os2File*)id;
-  assert( pFile!=0 );
-  if( pFile->locktype>=RESERVED_LOCK ){
-    r = 1;
-    OSTRACE(( "TEST WR-LOCK %d %d (local)\n", pFile->h, r ));
-  }else{
-    FILELOCK  LockArea,
-              UnlockArea;
-    APIRET rc = NO_ERROR;
-    memset(&LockArea, 0, sizeof(LockArea));
-    memset(&UnlockArea, 0, sizeof(UnlockArea));
-    LockArea.lOffset = RESERVED_BYTE;
-    LockArea.lRange = 1L;
-    UnlockArea.lOffset = 0L;
-    UnlockArea.lRange = 0L;
-    rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    OSTRACE(( "TEST WR-LOCK %d lock reserved byte rc=%d\n", pFile->h, rc ));
-    if( rc == NO_ERROR ){
-      APIRET rcu = NO_ERROR; /* return code for unlocking */
-      LockArea.lOffset = 0L;
-      LockArea.lRange = 0L;
-      UnlockArea.lOffset = RESERVED_BYTE;
-      UnlockArea.lRange = 1L;
-      rcu = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-      OSTRACE(( "TEST WR-LOCK %d unlock reserved byte r=%d\n", pFile->h, rcu ));
-    }
-    r = !(rc == NO_ERROR);
-    OSTRACE(( "TEST WR-LOCK %d %d (remote)\n", pFile->h, r ));
-  }
-  *pOut = r;
-  return SQLITE_OK;
-}
-
-/*
-** Lower the locking level on file descriptor id to locktype.  locktype
-** must be either NO_LOCK or SHARED_LOCK.
-**
-** If the locking level of the file descriptor is already at or below
-** the requested locking level, this routine is a no-op.
-**
-** It is not possible for this routine to fail if the second argument
-** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
-** might return SQLITE_IOERR;
-*/
-static int os2Unlock( sqlite3_file *id, int locktype ){
-  int type;
-  os2File *pFile = (os2File*)id;
-  APIRET rc = SQLITE_OK;
-  APIRET res = NO_ERROR;
-  FILELOCK  LockArea,
-            UnlockArea;
-  memset(&LockArea, 0, sizeof(LockArea));
-  memset(&UnlockArea, 0, sizeof(UnlockArea));
-  assert( pFile!=0 );
-  assert( locktype<=SHARED_LOCK );
-  OSTRACE(( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype ));
-  type = pFile->locktype;
-  if( type>=EXCLUSIVE_LOCK ){
-    LockArea.lOffset = 0L;
-    LockArea.lRange = 0L;
-    UnlockArea.lOffset = SHARED_FIRST;
-    UnlockArea.lRange = SHARED_SIZE;
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    OSTRACE(( "UNLOCK %d exclusive lock res=%d\n", pFile->h, res ));
-    if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
-      /* This should never happen.  We should always be able to
-      ** reacquire the read lock */
-      OSTRACE(( "UNLOCK %d to %d getReadLock() failed\n", pFile->h, locktype ));
-      rc = SQLITE_IOERR_UNLOCK;
-    }
-  }
-  if( type>=RESERVED_LOCK ){
-    LockArea.lOffset = 0L;
-    LockArea.lRange = 0L;
-    UnlockArea.lOffset = RESERVED_BYTE;
-    UnlockArea.lRange = 1L;
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    OSTRACE(( "UNLOCK %d reserved res=%d\n", pFile->h, res ));
-  }
-  if( locktype==NO_LOCK && type>=SHARED_LOCK ){
-    res = unlockReadLock(pFile);
-    OSTRACE(( "UNLOCK %d is %d want %d res=%d\n",
-              pFile->h, type, locktype, res ));
-  }
-  if( type>=PENDING_LOCK ){
-    LockArea.lOffset = 0L;
-    LockArea.lRange = 0L;
-    UnlockArea.lOffset = PENDING_BYTE;
-    UnlockArea.lRange = 1L;
-    res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
-    OSTRACE(( "UNLOCK %d pending res=%d\n", pFile->h, res ));
-  }
-  pFile->locktype = locktype;
-  OSTRACE(( "UNLOCK %d now %d\n", pFile->h, pFile->locktype ));
-  return rc;
-}
-
-/*
-** Control and query of the open file handle.
-*/
-static int os2FileControl(sqlite3_file *id, int op, void *pArg){
-  switch( op ){
-    case SQLITE_FCNTL_LOCKSTATE: {
-      *(int*)pArg = ((os2File*)id)->locktype;
-      OSTRACE(( "FCNTL_LOCKSTATE %d lock=%d\n",
-                ((os2File*)id)->h, ((os2File*)id)->locktype ));
-      return SQLITE_OK;
-    }
-    case SQLITE_FCNTL_CHUNK_SIZE: {
-      ((os2File*)id)->szChunk = *(int*)pArg;
-      return SQLITE_OK;
-    }
-    case SQLITE_FCNTL_SIZE_HINT: {
-      sqlite3_int64 sz = *(sqlite3_int64*)pArg;
-      SimulateIOErrorBenign(1);
-      os2Truncate(id, sz);
-      SimulateIOErrorBenign(0);
-      return SQLITE_OK;
-    }
-    case SQLITE_FCNTL_SYNC_OMITTED: {
-      return SQLITE_OK;
-    }
-  }
-  return SQLITE_NOTFOUND;
-}
-
-/*
-** Return the sector size in bytes of the underlying block device for
-** the specified file. This is almost always 512 bytes, but may be
-** larger for some devices.
-**
-** SQLite code assumes this function cannot fail. It also assumes that
-** if two files are created in the same file-system directory (i.e.
-** a database and its journal file) that the sector size will be the
-** same for both.
-*/
-static int os2SectorSize(sqlite3_file *id){
-  UNUSED_PARAMETER(id);
-  return SQLITE_DEFAULT_SECTOR_SIZE;
-}
-
-/*
-** Return a vector of device characteristics.
-*/
-static int os2DeviceCharacteristics(sqlite3_file *id){
-  UNUSED_PARAMETER(id);
-  return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN;
-}
-
-
-/*
-** Character set conversion objects used by conversion routines.
-*/
-static UconvObject ucUtf8 = NULL; /* convert between UTF-8 and UCS-2 */
-static UconvObject uclCp = NULL;  /* convert between local codepage and UCS-2 */
-
-/*
-** Helper function to initialize the conversion objects from and to UTF-8.
-*/
-static void initUconvObjects( void ){
-  if( UniCreateUconvObject( UTF_8, &ucUtf8 ) != ULS_SUCCESS )
-    ucUtf8 = NULL;
-  if ( UniCreateUconvObject( (UniChar *)L"@path=yes", &uclCp ) != ULS_SUCCESS )
-    uclCp = NULL;
-}
-
-/*
-** Helper function to free the conversion objects from and to UTF-8.
-*/
-static void freeUconvObjects( void ){
-  if ( ucUtf8 )
-    UniFreeUconvObject( ucUtf8 );
-  if ( uclCp )
-    UniFreeUconvObject( uclCp );
-  ucUtf8 = NULL;
-  uclCp = NULL;
-}
-
-/*
-** Helper function to convert UTF-8 filenames to local OS/2 codepage.
-** The two-step process: first convert the incoming UTF-8 string
-** into UCS-2 and then from UCS-2 to the current codepage.
-** The returned char pointer has to be freed.
-*/
-static char *convertUtf8PathToCp( const char *in ){
-  UniChar tempPath[CCHMAXPATH];
-  char *out = (char *)calloc( CCHMAXPATH, 1 );
-
-  if( !out )
-    return NULL;
-
-  if( !ucUtf8 || !uclCp )
-    initUconvObjects();
-
-  /* determine string for the conversion of UTF-8 which is CP1208 */
-  if( UniStrToUcs( ucUtf8, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
-    return out; /* if conversion fails, return the empty string */
-
-  /* conversion for current codepage which can be used for paths */
-  UniStrFromUcs( uclCp, out, tempPath, CCHMAXPATH );
-
-  return out;
-}
-
-/*
-** Helper function to convert filenames from local codepage to UTF-8.
-** The two-step process: first convert the incoming codepage-specific
-** string into UCS-2 and then from UCS-2 to the codepage of UTF-8.
-** The returned char pointer has to be freed.
-**
-** This function is non-static to be able to use this in shell.c and
-** similar applications that take command line arguments.
-*/
-char *convertCpPathToUtf8( const char *in ){
-  UniChar tempPath[CCHMAXPATH];
-  char *out = (char *)calloc( CCHMAXPATH, 1 );
-
-  if( !out )
-    return NULL;
-
-  if( !ucUtf8 || !uclCp )
-    initUconvObjects();
-
-  /* conversion for current codepage which can be used for paths */
-  if( UniStrToUcs( uclCp, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
-    return out; /* if conversion fails, return the empty string */
-
-  /* determine string for the conversion of UTF-8 which is CP1208 */
-  UniStrFromUcs( ucUtf8, out, tempPath, CCHMAXPATH );
-
-  return out;
-}
-
-
-#ifndef SQLITE_OMIT_WAL
-
-/*
-** Use main database file for interprocess locking. If un-defined
-** a separate file is created for this purpose. The file will be
-** used only to set file locks. There will be no data written to it.
-*/
-#define SQLITE_OS2_NO_WAL_LOCK_FILE     
-
-#if 0
-static void _ERR_TRACE( const char *fmt, ... ) {
-  va_list  ap;
-  va_start(ap, fmt);
-  vfprintf(stderr, fmt, ap);
-  fflush(stderr);
-}
-#define ERR_TRACE(rc, msg)        \
-        if( (rc) != SQLITE_OK ) _ERR_TRACE msg;
-#else
-#define ERR_TRACE(rc, msg)
-#endif
-
-/*
-** Helper functions to obtain and relinquish the global mutex. The
-** global mutex is used to protect os2ShmNodeList.
-**
-** Function os2ShmMutexHeld() is used to assert() that the global mutex 
-** is held when required. This function is only used as part of assert() 
-** statements. e.g.
-**
-**   os2ShmEnterMutex()
-**     assert( os2ShmMutexHeld() );
-**   os2ShmLeaveMutex()
-*/
-static void os2ShmEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
-}
-static void os2ShmLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
-}
-#ifdef SQLITE_DEBUG
-static int os2ShmMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
-}
-int GetCurrentProcessId(void) {
-  PPIB pib;
-  DosGetInfoBlocks(NULL, &pib);
-  return (int)pib->pib_ulpid;
-}
-#endif
-
-/*
-** Object used to represent a the shared memory area for a single log file.
-** When multiple threads all reference the same log-summary, each thread has
-** its own os2File object, but they all point to a single instance of this 
-** object.  In other words, each log-summary is opened only once per process.
-**
-** os2ShmMutexHeld() must be true when creating or destroying
-** this object or while reading or writing the following fields:
-**
-**      nRef
-**      pNext 
-**
-** The following fields are read-only after the object is created:
-** 
-**      szRegion
-**      hLockFile
-**      shmBaseName
-**
-** Either os2ShmNode.mutex must be held or os2ShmNode.nRef==0 and
-** os2ShmMutexHeld() is true when reading or writing any other field
-** in this structure.
-**
-*/
-struct os2ShmNode {
-  sqlite3_mutex *mutex;      /* Mutex to access this object */
-  os2ShmNode *pNext;         /* Next in list of all os2ShmNode objects */
-
-  int szRegion;              /* Size of shared-memory regions */
-
-  int nRegion;               /* Size of array apRegion */
-  void **apRegion;           /* Array of pointers to shared-memory regions */
-
-  int nRef;                  /* Number of os2ShmLink objects pointing to this */
-  os2ShmLink *pFirst;        /* First os2ShmLink object pointing to this */
-
-  HFILE hLockFile;           /* File used for inter-process memory locking */
-  char shmBaseName[1];       /* Name of the memory object !!! must last !!! */
-};
-
-
-/*
-** Structure used internally by this VFS to record the state of an
-** open shared memory connection.
-**
-** The following fields are initialized when this object is created and
-** are read-only thereafter:
-**
-**    os2Shm.pShmNode
-**    os2Shm.id
-**
-** All other fields are read/write.  The os2Shm.pShmNode->mutex must be held
-** while accessing any read/write fields.
-*/
-struct os2ShmLink {
-  os2ShmNode *pShmNode;      /* The underlying os2ShmNode object */
-  os2ShmLink *pNext;         /* Next os2Shm with the same os2ShmNode */
-  u32 sharedMask;            /* Mask of shared locks held */
-  u32 exclMask;              /* Mask of exclusive locks held */
-#ifdef SQLITE_DEBUG
-  u8 id;                     /* Id of this connection with its os2ShmNode */
-#endif
-};
-
-
-/*
-** A global list of all os2ShmNode objects.
-**
-** The os2ShmMutexHeld() must be true while reading or writing this list.
-*/
-static os2ShmNode *os2ShmNodeList = NULL;
-
-/*
-** Constants used for locking
-*/
-#ifdef  SQLITE_OS2_NO_WAL_LOCK_FILE
-#define OS2_SHM_BASE   (PENDING_BYTE + 0x10000)         /* first lock byte */
-#else
-#define OS2_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */
-#endif
-
-#define OS2_SHM_DMS    (OS2_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
-
-/*
-** Apply advisory locks for all n bytes beginning at ofst.
-*/
-#define _SHM_UNLCK  1   /* no lock */
-#define _SHM_RDLCK  2   /* shared lock, no wait */
-#define _SHM_WRLCK  3   /* exlusive lock, no wait */
-#define _SHM_WRLCK_WAIT 4 /* exclusive lock, wait */
-static int os2ShmSystemLock(
-  os2ShmNode *pNode,    /* Apply locks to this open shared-memory segment */
-  int lockType,         /* _SHM_UNLCK, _SHM_RDLCK, _SHM_WRLCK or _SHM_WRLCK_WAIT */
-  int ofst,             /* Offset to first byte to be locked/unlocked */
-  int nByte             /* Number of bytes to lock or unlock */
-){
-  APIRET rc;
-  FILELOCK area;
-  ULONG mode, timeout;
-
-  /* Access to the os2ShmNode object is serialized by the caller */
-  assert( sqlite3_mutex_held(pNode->mutex) || pNode->nRef==0 );
-
-  mode = 1;     /* shared lock */
-  timeout = 0;  /* no wait */
-  area.lOffset = ofst;
-  area.lRange = nByte;
-
-  switch( lockType ) {
-    case _SHM_WRLCK_WAIT:
-      timeout = (ULONG)-1;      /* wait forever */
-    case _SHM_WRLCK:
-      mode = 0;                 /* exclusive lock */
-    case _SHM_RDLCK:
-      rc = DosSetFileLocks(pNode->hLockFile, 
-                           NULL, &area, timeout, mode);
-      break;
-    /* case _SHM_UNLCK: */
-    default:
-      rc = DosSetFileLocks(pNode->hLockFile, 
-                           &area, NULL, 0, 0);
-      break;
-  }
-                          
-  OSTRACE(("SHM-LOCK %d %s %s 0x%08lx\n", 
-           pNode->hLockFile,
-           rc==SQLITE_OK ? "ok" : "failed",
-           lockType==_SHM_UNLCK ? "Unlock" : "Lock",
-           rc));
-
-  ERR_TRACE(rc, ("os2ShmSystemLock: %d %s\n", rc, pNode->shmBaseName))
-
-  return ( rc == 0 ) ?  SQLITE_OK : SQLITE_BUSY;
-}
-
-/*
-** Find an os2ShmNode in global list or allocate a new one, if not found.
-**
-** This is not a VFS shared-memory method; it is a utility function called
-** by VFS shared-memory methods.
-*/
-static int os2OpenSharedMemory( os2File *fd, int szRegion ) {
-  os2ShmLink *pLink;
-  os2ShmNode *pNode;
-  int cbShmName, rc = SQLITE_OK;
-  char shmName[CCHMAXPATH + 30];
-#ifndef SQLITE_OS2_NO_WAL_LOCK_FILE
-  ULONG action;
-#endif
-  
-  /* We need some additional space at the end to append the region number */
-  cbShmName = sprintf(shmName, "\\SHAREMEM\\%s", fd->zFullPathCp );
-  if( cbShmName >= CCHMAXPATH-8 )
-    return SQLITE_IOERR_SHMOPEN; 
-
-  /* Replace colon in file name to form a valid shared memory name */
-  shmName[10+1] = '!';
-
-  /* Allocate link object (we free it later in case of failure) */
-  pLink = sqlite3_malloc( sizeof(*pLink) );
-  if( !pLink )
-    return SQLITE_NOMEM;
-
-  /* Access node list */
-  os2ShmEnterMutex();
-
-  /* Find node by it's shared memory base name */
-  for( pNode = os2ShmNodeList; 
-       pNode && stricmp(shmName, pNode->shmBaseName) != 0; 
-       pNode = pNode->pNext )   ;
-
-  /* Not found: allocate a new node */
-  if( !pNode ) {
-    pNode = sqlite3_malloc( sizeof(*pNode) + cbShmName );
-    if( pNode ) {
-      memset(pNode, 0, sizeof(*pNode) );
-      pNode->szRegion = szRegion;
-      pNode->hLockFile = (HFILE)-1;      
-      strcpy(pNode->shmBaseName, shmName);
-
-#ifdef SQLITE_OS2_NO_WAL_LOCK_FILE
-      if( DosDupHandle(fd->h, &pNode->hLockFile) != 0 ) {
-#else
-      sprintf(shmName, "%s-lck", fd->zFullPathCp);
-      if( DosOpen((PSZ)shmName, &pNode->hLockFile, &action, 0, FILE_NORMAL, 
-                  OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_CREATE_IF_NEW,
-                  OPEN_ACCESS_READWRITE | OPEN_SHARE_DENYNONE | 
-                  OPEN_FLAGS_NOINHERIT | OPEN_FLAGS_FAIL_ON_ERROR,
-                  NULL) != 0 ) {
-#endif
-        sqlite3_free(pNode);  
-        rc = SQLITE_IOERR;
-      } else {
-        pNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-        if( !pNode->mutex ) {
-          sqlite3_free(pNode);  
-          rc = SQLITE_NOMEM;
-        }
-      }   
-    } else {
-      rc = SQLITE_NOMEM;
-    }
-    
-    if( rc == SQLITE_OK ) {
-      pNode->pNext = os2ShmNodeList;
-      os2ShmNodeList = pNode;
-    } else {
-      pNode = NULL;
-    }
-  } else if( pNode->szRegion != szRegion ) {
-    rc = SQLITE_IOERR_SHMSIZE;
-    pNode = NULL;
-  }
-
-  if( pNode ) {
-    sqlite3_mutex_enter(pNode->mutex);
-
-    memset(pLink, 0, sizeof(*pLink));
-
-    pLink->pShmNode = pNode;
-    pLink->pNext = pNode->pFirst;
-    pNode->pFirst = pLink;
-    pNode->nRef++;
-
-    fd->pShmLink = pLink;
-
-    sqlite3_mutex_leave(pNode->mutex);
-    
-  } else {
-    /* Error occured. Free our link object. */
-    sqlite3_free(pLink);  
-  }
-
-  os2ShmLeaveMutex();
-
-  ERR_TRACE(rc, ("os2OpenSharedMemory: %d  %s\n", rc, fd->zFullPathCp))  
-  
-  return rc;
-}
-
-/*
-** Purge the os2ShmNodeList list of all entries with nRef==0.
-**
-** This is not a VFS shared-memory method; it is a utility function called
-** by VFS shared-memory methods.
-*/
-static void os2PurgeShmNodes( int deleteFlag ) {
-  os2ShmNode *pNode;
-  os2ShmNode **ppNode;
-
-  os2ShmEnterMutex();
-  
-  ppNode = &os2ShmNodeList;
-
-  while( *ppNode ) {
-    pNode = *ppNode;
-
-    if( pNode->nRef == 0 ) {
-      *ppNode = pNode->pNext;   
-     
-      if( pNode->apRegion ) {
-        /* Prevent other processes from resizing the shared memory */
-        os2ShmSystemLock(pNode, _SHM_WRLCK_WAIT, OS2_SHM_DMS, 1);
-
-        while( pNode->nRegion-- ) {
-#ifdef SQLITE_DEBUG
-          int rc = 
-#endif          
-          DosFreeMem(pNode->apRegion[pNode->nRegion]);
-
-          OSTRACE(("SHM-PURGE pid-%d unmap region=%d %s\n",
-                  (int)GetCurrentProcessId(), pNode->nRegion,
-                  rc == 0 ? "ok" : "failed"));
-        }
-
-        /* Allow other processes to resize the shared memory */
-        os2ShmSystemLock(pNode, _SHM_UNLCK, OS2_SHM_DMS, 1);
-
-        sqlite3_free(pNode->apRegion);
-      }  
-
-      DosClose(pNode->hLockFile);
-      
-#ifndef SQLITE_OS2_NO_WAL_LOCK_FILE
-      if( deleteFlag ) {
-         char fileName[CCHMAXPATH];
-         /* Skip "\\SHAREMEM\\" */
-         sprintf(fileName, "%s-lck", pNode->shmBaseName + 10);
-         /* restore colon */
-         fileName[1] = ':';
-         
-         DosForceDelete(fileName); 
-      }
-#endif
-
-      sqlite3_mutex_free(pNode->mutex);
-
-      sqlite3_free(pNode);
-      
-    } else {
-      ppNode = &pNode->pNext;
-    }
-  } 
-
-  os2ShmLeaveMutex();
-}
-
-/*
-** This function is called to obtain a pointer to region iRegion of the
-** shared-memory associated with the database file id. Shared-memory regions
-** are numbered starting from zero. Each shared-memory region is szRegion
-** bytes in size.
-**
-** If an error occurs, an error code is returned and *pp is set to NULL.
-**
-** Otherwise, if the bExtend parameter is 0 and the requested shared-memory
-** region has not been allocated (by any client, including one running in a
-** separate process), then *pp is set to NULL and SQLITE_OK returned. If
-** bExtend is non-zero and the requested shared-memory region has not yet
-** been allocated, it is allocated by this function.
-**
-** If the shared-memory region has already been allocated or is allocated by
-** this call as described above, then it is mapped into this processes
-** address space (if it is not already), *pp is set to point to the mapped
-** memory and SQLITE_OK returned.
-*/
-static int os2ShmMap(
-  sqlite3_file *id,               /* Handle open on database file */
-  int iRegion,                    /* Region to retrieve */
-  int szRegion,                   /* Size of regions */
-  int bExtend,                    /* True to extend block if necessary */
-  void volatile **pp              /* OUT: Mapped memory */
-){
-  PVOID pvTemp;
-  void **apRegion;
-  os2ShmNode *pNode;
-  int n, rc = SQLITE_OK;
-  char shmName[CCHMAXPATH];
-  os2File *pFile = (os2File*)id;
-  
-  *pp = NULL;
-
-  if( !pFile->pShmLink )
-    rc = os2OpenSharedMemory( pFile, szRegion );
-  
-  if( rc == SQLITE_OK ) {
-    pNode = pFile->pShmLink->pShmNode ;
-    
-    sqlite3_mutex_enter(pNode->mutex);
-    
-    assert( szRegion==pNode->szRegion );
-
-    /* Unmapped region ? */
-    if( iRegion >= pNode->nRegion ) {
-      /* Prevent other processes from resizing the shared memory */
-      os2ShmSystemLock(pNode, _SHM_WRLCK_WAIT, OS2_SHM_DMS, 1);
-
-      apRegion = sqlite3_realloc(
-        pNode->apRegion, (iRegion + 1) * sizeof(apRegion[0]));
-
-      if( apRegion ) {
-        pNode->apRegion = apRegion;
-
-        while( pNode->nRegion <= iRegion ) {
-          sprintf(shmName, "%s-%u", 
-                  pNode->shmBaseName, pNode->nRegion);
-
-          if( DosGetNamedSharedMem(&pvTemp, (PSZ)shmName, 
-                PAG_READ | PAG_WRITE) != NO_ERROR ) {
-            if( !bExtend )
-              break;
-
-            if( DosAllocSharedMem(&pvTemp, (PSZ)shmName, szRegion,
-                  PAG_READ | PAG_WRITE | PAG_COMMIT | OBJ_ANY) != NO_ERROR && 
-                DosAllocSharedMem(&pvTemp, (PSZ)shmName, szRegion,
-                  PAG_READ | PAG_WRITE | PAG_COMMIT) != NO_ERROR ) { 
-              rc = SQLITE_NOMEM;
-              break;
-            }
-          }
-
-          apRegion[pNode->nRegion++] = pvTemp;
-        }
-
-        /* zero out remaining entries */ 
-        for( n = pNode->nRegion; n <= iRegion; n++ )
-          pNode->apRegion[n] = NULL;
-
-        /* Return this region (maybe zero) */
-        *pp = pNode->apRegion[iRegion];
-      } else {
-        rc = SQLITE_NOMEM;
-      }
-
-      /* Allow other processes to resize the shared memory */
-      os2ShmSystemLock(pNode, _SHM_UNLCK, OS2_SHM_DMS, 1);
-      
-    } else {
-      /* Region has been mapped previously */
-      *pp = pNode->apRegion[iRegion];
-    }
-
-    sqlite3_mutex_leave(pNode->mutex);
-  } 
-
-  ERR_TRACE(rc, ("os2ShmMap: %s iRgn = %d, szRgn = %d, bExt = %d : %d\n", 
-                 pFile->zFullPathCp, iRegion, szRegion, bExtend, rc))
-          
-  return rc;
-}
-
-/*
-** Close a connection to shared-memory.  Delete the underlying
-** storage if deleteFlag is true.
-**
-** If there is no shared memory associated with the connection then this
-** routine is a harmless no-op.
-*/
-static int os2ShmUnmap(
-  sqlite3_file *id,               /* The underlying database file */
-  int deleteFlag                  /* Delete shared-memory if true */
-){
-  os2File *pFile = (os2File*)id;
-  os2ShmLink *pLink = pFile->pShmLink;
-  
-  if( pLink ) {
-    int nRef = -1;
-    os2ShmLink **ppLink;
-    os2ShmNode *pNode = pLink->pShmNode;
-
-    sqlite3_mutex_enter(pNode->mutex);
-    
-    for( ppLink = &pNode->pFirst;
-         *ppLink && *ppLink != pLink;
-         ppLink = &(*ppLink)->pNext )   ;
-         
-    assert(*ppLink);
-
-    if( *ppLink ) {
-      *ppLink = pLink->pNext;
-      nRef = --pNode->nRef;
-    } else {
-      ERR_TRACE(1, ("os2ShmUnmap: link not found ! %s\n", 
-                    pNode->shmBaseName))
-    }
-    
-    pFile->pShmLink = NULL;
-    sqlite3_free(pLink);
-
-    sqlite3_mutex_leave(pNode->mutex);
-    
-    if( nRef == 0 )
-      os2PurgeShmNodes( deleteFlag );
-  }
-
-  return SQLITE_OK;
-}
-
-/*
-** Change the lock state for a shared-memory segment.
-**
-** Note that the relationship between SHAREd and EXCLUSIVE locks is a little
-** different here than in posix.  In xShmLock(), one can go from unlocked
-** to shared and back or from unlocked to exclusive and back.  But one may
-** not go from shared to exclusive or from exclusive to shared.
-*/
-static int os2ShmLock(
-  sqlite3_file *id,          /* Database file holding the shared memory */
-  int ofst,                  /* First lock to acquire or release */
-  int n,                     /* Number of locks to acquire or release */
-  int flags                  /* What to do with the lock */
-){
-  u32 mask;                             /* Mask of locks to take or release */
-  int rc = SQLITE_OK;                   /* Result code */
-  os2File *pFile = (os2File*)id;
-  os2ShmLink *p = pFile->pShmLink;      /* The shared memory being locked */
-  os2ShmLink *pX;                       /* For looping over all siblings */
-  os2ShmNode *pShmNode = p->pShmNode;   /* Our node */
-  
-  assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );
-  assert( n>=1 );
-  assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)
-       || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)
-       || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
-       || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
-  assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
-
-  mask = (u32)((1U<<(ofst+n)) - (1U<<ofst));
-  assert( n>1 || mask==(1<<ofst) );
-
-
-  sqlite3_mutex_enter(pShmNode->mutex);
-
-  if( flags & SQLITE_SHM_UNLOCK ){
-    u32 allMask = 0; /* Mask of locks held by siblings */
-
-    /* See if any siblings hold this same lock */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( pX==p ) continue;
-      assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
-      allMask |= pX->sharedMask;
-    }
-
-    /* Unlock the system-level locks */
-    if( (mask & allMask)==0 ){
-      rc = os2ShmSystemLock(pShmNode, _SHM_UNLCK, ofst+OS2_SHM_BASE, n);
-    }else{
-      rc = SQLITE_OK;
-    }
-
-    /* Undo the local locks */
-    if( rc==SQLITE_OK ){
-      p->exclMask &= ~mask;
-      p->sharedMask &= ~mask;
-    } 
-  }else if( flags & SQLITE_SHM_SHARED ){
-    u32 allShared = 0;  /* Union of locks held by connections other than "p" */
-
-    /* Find out which shared locks are already held by sibling connections.
-    ** If any sibling already holds an exclusive lock, go ahead and return
-    ** SQLITE_BUSY.
-    */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( (pX->exclMask & mask)!=0 ){
-        rc = SQLITE_BUSY;
-        break;
-      }
-      allShared |= pX->sharedMask;
-    }
-
-    /* Get shared locks at the system level, if necessary */
-    if( rc==SQLITE_OK ){
-      if( (allShared & mask)==0 ){
-        rc = os2ShmSystemLock(pShmNode, _SHM_RDLCK, ofst+OS2_SHM_BASE, n);
-      }else{
-        rc = SQLITE_OK;
-      }
-    }
-
-    /* Get the local shared locks */
-    if( rc==SQLITE_OK ){
-      p->sharedMask |= mask;
-    }
-  }else{
-    /* Make sure no sibling connections hold locks that will block this
-    ** lock.  If any do, return SQLITE_BUSY right away.
-    */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
-        rc = SQLITE_BUSY;
-        break;
-      }
-    }
-  
-    /* Get the exclusive locks at the system level.  Then if successful
-    ** also mark the local connection as being locked.
-    */
-    if( rc==SQLITE_OK ){
-      rc = os2ShmSystemLock(pShmNode, _SHM_WRLCK, ofst+OS2_SHM_BASE, n);
-      if( rc==SQLITE_OK ){
-        assert( (p->sharedMask & mask)==0 );
-        p->exclMask |= mask;
-      }
-    }
-  }
-
-  sqlite3_mutex_leave(pShmNode->mutex);
-  
-  OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x %s\n",
-           p->id, (int)GetCurrentProcessId(), p->sharedMask, p->exclMask,
-           rc ? "failed" : "ok"));
-
-  ERR_TRACE(rc, ("os2ShmLock: ofst = %d, n = %d, flags = 0x%x -> %d \n", 
-                 ofst, n, flags, rc))
-                  
-  return rc; 
-}
-
-/*
-** Implement a memory barrier or memory fence on shared memory.
-**
-** All loads and stores begun before the barrier must complete before
-** any load or store begun after the barrier.
-*/
-static void os2ShmBarrier(
-  sqlite3_file *id                /* Database file holding the shared memory */
-){
-  UNUSED_PARAMETER(id);
-  os2ShmEnterMutex();
-  os2ShmLeaveMutex();
-}
-
-#else
-# define os2ShmMap     0
-# define os2ShmLock    0
-# define os2ShmBarrier 0
-# define os2ShmUnmap   0
-#endif /* #ifndef SQLITE_OMIT_WAL */
-
-
-/*
-** This vector defines all the methods that can operate on an
-** sqlite3_file for os2.
-*/
-static const sqlite3_io_methods os2IoMethod = {
-  2,                              /* iVersion */
-  os2Close,                       /* xClose */
-  os2Read,                        /* xRead */
-  os2Write,                       /* xWrite */
-  os2Truncate,                    /* xTruncate */
-  os2Sync,                        /* xSync */
-  os2FileSize,                    /* xFileSize */
-  os2Lock,                        /* xLock */
-  os2Unlock,                      /* xUnlock */
-  os2CheckReservedLock,           /* xCheckReservedLock */
-  os2FileControl,                 /* xFileControl */
-  os2SectorSize,                  /* xSectorSize */
-  os2DeviceCharacteristics,       /* xDeviceCharacteristics */
-  os2ShmMap,                      /* xShmMap */
-  os2ShmLock,                     /* xShmLock */
-  os2ShmBarrier,                  /* xShmBarrier */
-  os2ShmUnmap                     /* xShmUnmap */
-};
-
-
-/***************************************************************************
-** Here ends the I/O methods that form the sqlite3_io_methods object.
-**
-** The next block of code implements the VFS methods.
-****************************************************************************/
-
-/*
-** Create a temporary file name in zBuf.  zBuf must be big enough to
-** hold at pVfs->mxPathname characters.
-*/
-static int getTempname(int nBuf, char *zBuf ){
-  static const char zChars[] =
-    "abcdefghijklmnopqrstuvwxyz"
-    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-    "0123456789";
-  int i, j;
-  PSZ zTempPathCp;      
-  char zTempPath[CCHMAXPATH];
-  ULONG ulDriveNum, ulDriveMap;
-  
-  /* It's odd to simulate an io-error here, but really this is just
-  ** using the io-error infrastructure to test that SQLite handles this
-  ** function failing. 
-  */
-  SimulateIOError( return SQLITE_IOERR );
-
-  if( sqlite3_temp_directory ) {
-    sqlite3_snprintf(CCHMAXPATH-30, zTempPath, "%s", sqlite3_temp_directory);
-  } else if( DosScanEnv( (PSZ)"TEMP",   &zTempPathCp ) == NO_ERROR ||
-             DosScanEnv( (PSZ)"TMP",    &zTempPathCp ) == NO_ERROR ||
-             DosScanEnv( (PSZ)"TMPDIR", &zTempPathCp ) == NO_ERROR ) {
-    char *zTempPathUTF = convertCpPathToUtf8( (char *)zTempPathCp );
-    sqlite3_snprintf(CCHMAXPATH-30, zTempPath, "%s", zTempPathUTF);
-    free( zTempPathUTF );
-  } else if( DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap ) == NO_ERROR ) {
-    zTempPath[0] = (char)('A' + ulDriveNum - 1);
-    zTempPath[1] = ':'; 
-    zTempPath[2] = '\0'; 
-  } else {
-    zTempPath[0] = '\0'; 
-  }
-  
-  /* Strip off a trailing slashes or backslashes, otherwise we would get *
-   * multiple (back)slashes which causes DosOpen() to fail.              *
-   * Trailing spaces are not allowed, either.                            */
-  j = sqlite3Strlen30(zTempPath);
-  while( j > 0 && ( zTempPath[j-1] == '\\' || zTempPath[j-1] == '/' || 
-                    zTempPath[j-1] == ' ' ) ){
-    j--;
-  }
-  zTempPath[j] = '\0';
-  
-  /* We use 20 bytes to randomize the name */
-  sqlite3_snprintf(nBuf-22, zBuf,
-                   "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath);
-  j = sqlite3Strlen30(zBuf);
-  sqlite3_randomness( 20, &zBuf[j] );
-  for( i = 0; i < 20; i++, j++ ){
-    zBuf[j] = zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
-  }
-  zBuf[j] = 0;
-
-  OSTRACE(( "TEMP FILENAME: %s\n", zBuf ));
-  return SQLITE_OK;
-}
-
-
-/*
-** Turn a relative pathname into a full pathname.  Write the full
-** pathname into zFull[].  zFull[] will be at least pVfs->mxPathname
-** bytes in size.
-*/
-static int os2FullPathname(
-  sqlite3_vfs *pVfs,          /* Pointer to vfs object */
-  const char *zRelative,      /* Possibly relative input path */
-  int nFull,                  /* Size of output buffer in bytes */
-  char *zFull                 /* Output buffer */
-){
-  char *zRelativeCp = convertUtf8PathToCp( zRelative );
-  char zFullCp[CCHMAXPATH] = "\0";
-  char *zFullUTF;
-  APIRET rc = DosQueryPathInfo( (PSZ)zRelativeCp, FIL_QUERYFULLNAME, 
-                                zFullCp, CCHMAXPATH );
-  free( zRelativeCp );
-  zFullUTF = convertCpPathToUtf8( zFullCp );
-  sqlite3_snprintf( nFull, zFull, zFullUTF );
-  free( zFullUTF );
-  return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
-}
-
-
-/*
-** Open a file.
-*/
-static int os2Open(
-  sqlite3_vfs *pVfs,            /* Not used */
-  const char *zName,            /* Name of the file (UTF-8) */
-  sqlite3_file *id,             /* Write the SQLite file handle here */
-  int flags,                    /* Open mode flags */
-  int *pOutFlags                /* Status return flags */
-){
-  HFILE h;
-  ULONG ulOpenFlags = 0;
-  ULONG ulOpenMode = 0;
-  ULONG ulAction = 0;
-  ULONG rc;
-  os2File *pFile = (os2File*)id;
-  const char *zUtf8Name = zName;
-  char *zNameCp;
-  char  zTmpname[CCHMAXPATH];
-
-  int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
-  int isCreate     = (flags & SQLITE_OPEN_CREATE);
-  int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
-#ifndef NDEBUG
-  int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
-  int isReadonly   = (flags & SQLITE_OPEN_READONLY);
-  int eType        = (flags & 0xFFFFFF00);
-  int isOpenJournal = (isCreate && (
-        eType==SQLITE_OPEN_MASTER_JOURNAL 
-     || eType==SQLITE_OPEN_MAIN_JOURNAL 
-     || eType==SQLITE_OPEN_WAL
-  ));
-#endif
-
-  UNUSED_PARAMETER(pVfs);
-  assert( id!=0 );
-
-  /* Check the following statements are true: 
-  **
-  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 
-  **   (b) if CREATE is set, then READWRITE must also be set, and
-  **   (c) if EXCLUSIVE is set, then CREATE must also be set.
-  **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
-  */
-  assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
-  assert(isCreate==0 || isReadWrite);
-  assert(isExclusive==0 || isCreate);
-  assert(isDelete==0 || isCreate);
-
-  /* The main DB, main journal, WAL file and master journal are never 
-  ** automatically deleted. Nor are they ever temporary files.  */
-  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
-  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
-  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );
-  assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
-
-  /* Assert that the upper layer has set one of the "file-type" flags. */
-  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 
-       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 
-       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL 
-       || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
-  );
-
-  memset( pFile, 0, sizeof(*pFile) );
-  pFile->h = (HFILE)-1;
-
-  /* If the second argument to this function is NULL, generate a 
-  ** temporary file name to use 
-  */
-  if( !zUtf8Name ){
-    assert(isDelete && !isOpenJournal);
-    rc = getTempname(CCHMAXPATH, zTmpname);
-    if( rc!=SQLITE_OK ){
-      return rc;
-    }
-    zUtf8Name = zTmpname;
-  }
-
-  if( isReadWrite ){
-    ulOpenMode |= OPEN_ACCESS_READWRITE;
-  }else{
-    ulOpenMode |= OPEN_ACCESS_READONLY;
-  }
-
-  /* Open in random access mode for possibly better speed.  Allow full
-  ** sharing because file locks will provide exclusive access when needed.
-  ** The handle should not be inherited by child processes and we don't 
-  ** want popups from the critical error handler.
-  */
-  ulOpenMode |= OPEN_FLAGS_RANDOM | OPEN_SHARE_DENYNONE | 
-                OPEN_FLAGS_NOINHERIT | OPEN_FLAGS_FAIL_ON_ERROR;
-
-  /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is 
-  ** created. SQLite doesn't use it to indicate "exclusive access" 
-  ** as it is usually understood.
-  */
-  if( isExclusive ){
-    /* Creates a new file, only if it does not already exist. */
-    /* If the file exists, it fails. */
-    ulOpenFlags |= OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_FAIL_IF_EXISTS;
-  }else if( isCreate ){
-    /* Open existing file, or create if it doesn't exist */
-    ulOpenFlags |= OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS;
-  }else{
-    /* Opens a file, only if it exists. */
-    ulOpenFlags |= OPEN_ACTION_FAIL_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS;
-  }
-
-  zNameCp = convertUtf8PathToCp( zUtf8Name );
-  rc = DosOpen( (PSZ)zNameCp,
-                &h,
-                &ulAction,
-                0L,
-                FILE_NORMAL,
-                ulOpenFlags,
-                ulOpenMode,
-                (PEAOP2)NULL );
-  free( zNameCp );
-
-  if( rc != NO_ERROR ){
-    OSTRACE(( "OPEN Invalid handle rc=%d: zName=%s, ulAction=%#lx, ulFlags=%#lx, ulMode=%#lx\n",
-              rc, zUtf8Name, ulAction, ulOpenFlags, ulOpenMode ));
-
-    if( isReadWrite ){
-      return os2Open( pVfs, zName, id,
-                      ((flags|SQLITE_OPEN_READONLY)&~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
-                      pOutFlags );
-    }else{
-      return SQLITE_CANTOPEN;
-    }
-  }
-
-  if( pOutFlags ){
-    *pOutFlags = isReadWrite ? SQLITE_OPEN_READWRITE : SQLITE_OPEN_READONLY;
-  }
-
-  os2FullPathname( pVfs, zUtf8Name, sizeof( zTmpname ), zTmpname );
-  pFile->zFullPathCp = convertUtf8PathToCp( zTmpname );
-  pFile->pMethod = &os2IoMethod;
-  pFile->flags = flags;
-  pFile->h = h;
-
-  OpenCounter(+1);
-  OSTRACE(( "OPEN %d pOutFlags=%d\n", pFile->h, pOutFlags ));
-  return SQLITE_OK;
-}
-
-/*
-** Delete the named file.
-*/
-static int os2Delete(
-  sqlite3_vfs *pVfs,                     /* Not used on os2 */
-  const char *zFilename,                 /* Name of file to delete */
-  int syncDir                            /* Not used on os2 */
-){
-  APIRET rc;
-  char *zFilenameCp;
-  SimulateIOError( return SQLITE_IOERR_DELETE );
-  zFilenameCp = convertUtf8PathToCp( zFilename );
-  rc = DosDelete( (PSZ)zFilenameCp );
-  free( zFilenameCp );
-  OSTRACE(( "DELETE \"%s\"\n", zFilename ));
-  return (rc == NO_ERROR ||
-          rc == ERROR_FILE_NOT_FOUND ||
-          rc == ERROR_PATH_NOT_FOUND ) ? SQLITE_OK : SQLITE_IOERR_DELETE;
-}
-
-/*
-** Check the existance and status of a file.
-*/
-static int os2Access(
-  sqlite3_vfs *pVfs,        /* Not used on os2 */
-  const char *zFilename,    /* Name of file to check */
-  int flags,                /* Type of test to make on this file */
-  int *pOut                 /* Write results here */
-){
-  APIRET rc;
-  FILESTATUS3 fsts3ConfigInfo;
-  char *zFilenameCp;
-
-  UNUSED_PARAMETER(pVfs);
-  SimulateIOError( return SQLITE_IOERR_ACCESS; );
-  
-  zFilenameCp = convertUtf8PathToCp( zFilename );
-  rc = DosQueryPathInfo( (PSZ)zFilenameCp, FIL_STANDARD,
-                         &fsts3ConfigInfo, sizeof(FILESTATUS3) );
-  free( zFilenameCp );
-  OSTRACE(( "ACCESS fsts3ConfigInfo.attrFile=%d flags=%d rc=%d\n",
-            fsts3ConfigInfo.attrFile, flags, rc ));
-
-  switch( flags ){
-    case SQLITE_ACCESS_EXISTS:
-      /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
-      ** as if it does not exist.
-      */
-      if( fsts3ConfigInfo.cbFile == 0 ) 
-        rc = ERROR_FILE_NOT_FOUND;
-      break;
-    case SQLITE_ACCESS_READ:
-      break;
-    case SQLITE_ACCESS_READWRITE:
-      if( fsts3ConfigInfo.attrFile & FILE_READONLY )
-        rc = ERROR_ACCESS_DENIED;
-      break;
-    default:
-      rc = ERROR_FILE_NOT_FOUND;
-      assert( !"Invalid flags argument" );
-  }
-
-  *pOut = (rc == NO_ERROR);
-  OSTRACE(( "ACCESS %s flags %d: rc=%d\n", zFilename, flags, *pOut ));
-
-  return SQLITE_OK;
-}
-
-
-#ifndef SQLITE_OMIT_LOAD_EXTENSION
-/*
-** Interfaces for opening a shared library, finding entry points
-** within the shared library, and closing the shared library.
-*/
-/*
-** Interfaces for opening a shared library, finding entry points
-** within the shared library, and closing the shared library.
-*/
-static void *os2DlOpen(sqlite3_vfs *pVfs, const char *zFilename){
-  HMODULE hmod;
-  APIRET rc;
-  char *zFilenameCp = convertUtf8PathToCp(zFilename);
-  rc = DosLoadModule(NULL, 0, (PSZ)zFilenameCp, &hmod);
-  free(zFilenameCp);
-  return rc != NO_ERROR ? 0 : (void*)hmod;
-}
-/*
-** A no-op since the error code is returned on the DosLoadModule call.
-** os2Dlopen returns zero if DosLoadModule is not successful.
-*/
-static void os2DlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
-/* no-op */
-}
-static void (*os2DlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol))(void){
-  PFN pfn;
-  APIRET rc;
-  rc = DosQueryProcAddr((HMODULE)pHandle, 0L, (PSZ)zSymbol, &pfn);
-  if( rc != NO_ERROR ){
-    /* if the symbol itself was not found, search again for the same
-     * symbol with an extra underscore, that might be needed depending
-     * on the calling convention */
-    char _zSymbol[256] = "_";
-    strncat(_zSymbol, zSymbol, 254);
-    rc = DosQueryProcAddr((HMODULE)pHandle, 0L, (PSZ)_zSymbol, &pfn);
-  }
-  return rc != NO_ERROR ? 0 : (void(*)(void))pfn;
-}
-static void os2DlClose(sqlite3_vfs *pVfs, void *pHandle){
-  DosFreeModule((HMODULE)pHandle);
-}
-#else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
-  #define os2DlOpen 0
-  #define os2DlError 0
-  #define os2DlSym 0
-  #define os2DlClose 0
-#endif
-
-
-/*
-** Write up to nBuf bytes of randomness into zBuf.
-*/
-static int os2Randomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf ){
-  int n = 0;
-#if defined(SQLITE_TEST)
-  n = nBuf;
-  memset(zBuf, 0, nBuf);
-#else
-  int i;                           
-  PPIB ppib;
-  PTIB ptib;
-  DATETIME dt; 
-  static unsigned c = 0;
-  /* Ordered by variation probability */
-  static ULONG svIdx[6] = { QSV_MS_COUNT, QSV_TIME_LOW,
-                            QSV_MAXPRMEM, QSV_MAXSHMEM,
-                            QSV_TOTAVAILMEM, QSV_TOTRESMEM };
-
-  /* 8 bytes; timezone and weekday don't increase the randomness much */
-  if( (int)sizeof(dt)-3 <= nBuf - n ){
-    c += 0x0100;
-    DosGetDateTime(&dt);
-    dt.year = (USHORT)((dt.year - 1900) | c);
-    memcpy(&zBuf[n], &dt, sizeof(dt)-3);
-    n += sizeof(dt)-3;
-  }
-
-  /* 4 bytes; PIDs and TIDs are 16 bit internally, so combine them */
-  if( (int)sizeof(ULONG) <= nBuf - n ){
-    DosGetInfoBlocks(&ptib, &ppib);
-    *(PULONG)&zBuf[n] = MAKELONG(ppib->pib_ulpid,
-                                 ptib->tib_ptib2->tib2_ultid);
-    n += sizeof(ULONG);
-  }
-
-  /* Up to 6 * 4 bytes; variables depend on the system state */
-  for( i = 0; i < 6 && (int)sizeof(ULONG) <= nBuf - n; i++ ){
-    DosQuerySysInfo(svIdx[i], svIdx[i], 
-                    (PULONG)&zBuf[n], sizeof(ULONG));
-    n += sizeof(ULONG);
-  } 
-#endif
-
-  return n;
-}
-
-/*
-** Sleep for a little while.  Return the amount of time slept.
-** The argument is the number of microseconds we want to sleep.
-** The return value is the number of microseconds of sleep actually
-** requested from the underlying operating system, a number which
-** might be greater than or equal to the argument, but not less
-** than the argument.
-*/
-static int os2Sleep( sqlite3_vfs *pVfs, int microsec ){
-  DosSleep( (microsec/1000) );
-  return microsec;
-}
-
-/*
-** The following variable, if set to a non-zero value, becomes the result
-** returned from sqlite3OsCurrentTime().  This is used for testing.
-*/
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_current_time = 0;
-#endif
-
-/*
-** Find the current time (in Universal Coordinated Time).  Write into *piNow
-** the current time and date as a Julian Day number times 86_400_000.  In
-** other words, write into *piNow the number of milliseconds since the Julian
-** epoch of noon in Greenwich on November 24, 4714 B.C according to the
-** proleptic Gregorian calendar.
-**
-** On success, return 0.  Return 1 if the time and date cannot be found.
-*/
-static int os2CurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
-#ifdef SQLITE_TEST
-  static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
-#endif
-  int year, month, datepart, timepart;
- 
-  DATETIME dt;
-  DosGetDateTime( &dt );
-
-  year = dt.year;
-  month = dt.month;
-
-  /* Calculations from http://www.astro.keele.ac.uk/~rno/Astronomy/hjd.html
-  ** http://www.astro.keele.ac.uk/~rno/Astronomy/hjd-0.1.c
-  ** Calculate the Julian days
-  */
-  datepart = (int)dt.day - 32076 +
-    1461*(year + 4800 + (month - 14)/12)/4 +
-    367*(month - 2 - (month - 14)/12*12)/12 -
-    3*((year + 4900 + (month - 14)/12)/100)/4;
-
-  /* Time in milliseconds, hours to noon added */
-  timepart = 12*3600*1000 + dt.hundredths*10 + dt.seconds*1000 +
-    ((int)dt.minutes + dt.timezone)*60*1000 + dt.hours*3600*1000;
-
-  *piNow = (sqlite3_int64)datepart*86400*1000 + timepart;
-   
-#ifdef SQLITE_TEST
-  if( sqlite3_current_time ){
-    *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
-  }
-#endif
-
-  UNUSED_PARAMETER(pVfs);
-  return 0;
-}
-
-/*
-** Find the current time (in Universal Coordinated Time).  Write the
-** current time and date as a Julian Day number into *prNow and
-** return 0.  Return 1 if the time and date cannot be found.
-*/
-static int os2CurrentTime( sqlite3_vfs *pVfs, double *prNow ){
-  int rc;
-  sqlite3_int64 i;
-  rc = os2CurrentTimeInt64(pVfs, &i);
-  if( !rc ){
-    *prNow = i/86400000.0;
-  }
-  return rc;
-}
-
-/*
-** The idea is that this function works like a combination of
-** GetLastError() and FormatMessage() on windows (or errno and
-** strerror_r() on unix). After an error is returned by an OS
-** function, SQLite calls this function with zBuf pointing to
-** a buffer of nBuf bytes. The OS layer should populate the
-** buffer with a nul-terminated UTF-8 encoded error message
-** describing the last IO error to have occurred within the calling
-** thread.
-**
-** If the error message is too large for the supplied buffer,
-** it should be truncated. The return value of xGetLastError
-** is zero if the error message fits in the buffer, or non-zero
-** otherwise (if the message was truncated). If non-zero is returned,
-** then it is not necessary to include the nul-terminator character
-** in the output buffer.
-**
-** Not supplying an error message will have no adverse effect
-** on SQLite. It is fine to have an implementation that never
-** returns an error message:
-**
-**   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
-**     assert(zBuf[0]=='\0');
-**     return 0;
-**   }
-**
-** However if an error message is supplied, it will be incorporated
-** by sqlite into the error message available to the user using
-** sqlite3_errmsg(), possibly making IO errors easier to debug.
-*/
-static int os2GetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
-  assert(zBuf[0]=='\0');
-  return 0;
-}
-
-/*
-** Initialize and deinitialize the operating system interface.
-*/
-SQLITE_API int sqlite3_os_init(void){
-  static sqlite3_vfs os2Vfs = {
-    3,                 /* iVersion */
-    sizeof(os2File),   /* szOsFile */
-    CCHMAXPATH,        /* mxPathname */
-    0,                 /* pNext */
-    "os2",             /* zName */
-    0,                 /* pAppData */
-
-    os2Open,           /* xOpen */
-    os2Delete,         /* xDelete */
-    os2Access,         /* xAccess */
-    os2FullPathname,   /* xFullPathname */
-    os2DlOpen,         /* xDlOpen */
-    os2DlError,        /* xDlError */
-    os2DlSym,          /* xDlSym */
-    os2DlClose,        /* xDlClose */
-    os2Randomness,     /* xRandomness */
-    os2Sleep,          /* xSleep */
-    os2CurrentTime,    /* xCurrentTime */
-    os2GetLastError,   /* xGetLastError */
-    os2CurrentTimeInt64, /* xCurrentTimeInt64 */
-    0,                 /* xSetSystemCall */
-    0,                 /* xGetSystemCall */
-    0                  /* xNextSystemCall */
-  };
-  sqlite3_vfs_register(&os2Vfs, 1);
-  initUconvObjects();
-/*  sqlite3OSTrace = 1; */
-  return SQLITE_OK;
-}
-SQLITE_API int sqlite3_os_end(void){
-  freeUconvObjects();
-  return SQLITE_OK;
-}
-
-#endif /* SQLITE_OS_OS2 */
-
-/************** End of os_os2.c **********************************************/
 /************** Begin file os_unix.c *****************************************/
 /*
 ** 2004 May 22
@@ -24440,6 +29170,7 @@ SQLITE_API int sqlite3_os_end(void){
 **   *  Definitions of sqlite3_vfs objects for all locking methods
 **      plus implementations of sqlite3_os_init() and sqlite3_os_end().
 */
+/* #include "sqliteInt.h" */
 #if SQLITE_OS_UNIX              /* This file is used on unix only */
 
 /*
@@ -24467,42 +29198,17 @@ SQLITE_API int sqlite3_os_end(void){
 #  endif
 #endif
 
-/*
-** Define the OS_VXWORKS pre-processor macro to 1 if building on 
-** vxworks, or 0 otherwise.
-*/
-#ifndef OS_VXWORKS
-#  if defined(__RTP__) || defined(_WRS_KERNEL)
-#    define OS_VXWORKS 1
-#  else
-#    define OS_VXWORKS 0
-#  endif
+/* Use pread() and pwrite() if they are available */
+#if defined(__APPLE__)
+# define HAVE_PREAD 1
+# define HAVE_PWRITE 1
 #endif
-
-/*
-** These #defines should enable >2GB file support on Posix if the
-** underlying operating system supports it.  If the OS lacks
-** large file support, these should be no-ops.
-**
-** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
-** on the compiler command line.  This is necessary if you are compiling
-** on a recent machine (ex: RedHat 7.2) but you want your code to work
-** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
-** without this option, LFS is enable.  But LFS does not exist in the kernel
-** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
-** portability you should omit LFS.
-**
-** The previous paragraph was written in 2005.  (This paragraph is written
-** on 2008-11-28.) These days, all Linux kernels support large files, so
-** you should probably leave LFS enabled.  But some embedded platforms might
-** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.
-*/
-#ifndef SQLITE_DISABLE_LFS
-# define _LARGE_FILE       1
-# ifndef _FILE_OFFSET_BITS
-#   define _FILE_OFFSET_BITS 64
-# endif
-# define _LARGEFILE_SOURCE 1
+#if defined(HAVE_PREAD64) && defined(HAVE_PWRITE64)
+# undef USE_PREAD
+# define USE_PREAD64 1
+#elif defined(HAVE_PREAD) && defined(HAVE_PWRITE)
+# undef USE_PREAD64
+# define USE_PREAD 1
 #endif
 
 /*
@@ -24515,22 +29221,34 @@ SQLITE_API int sqlite3_os_end(void){
 /* #include <time.h> */
 #include <sys/time.h>
 #include <errno.h>
-#ifndef SQLITE_OMIT_WAL
-#include <sys/mman.h>
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+# include <sys/mman.h>
 #endif
 
 #if SQLITE_ENABLE_LOCKING_STYLE
 # include <sys/ioctl.h>
-# if OS_VXWORKS
-#  include <semaphore.h>
-#  include <limits.h>
-# else
-#  include <sys/file.h>
-#  include <sys/param.h>
-# endif
+# include <sys/file.h>
+# include <sys/param.h>
 #endif /* SQLITE_ENABLE_LOCKING_STYLE */
 
-#if defined(__APPLE__) || (SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS)
+#if defined(__APPLE__) && ((__MAC_OS_X_VERSION_MIN_REQUIRED > 1050) || \
+                           (__IPHONE_OS_VERSION_MIN_REQUIRED > 2000))
+#  if (!defined(TARGET_OS_EMBEDDED) || (TARGET_OS_EMBEDDED==0)) \
+       && (!defined(TARGET_IPHONE_SIMULATOR) || (TARGET_IPHONE_SIMULATOR==0))
+#    define HAVE_GETHOSTUUID 1
+#  else
+#    warning "gethostuuid() is disabled."
+#  endif
+#endif
+
+
+#if OS_VXWORKS
+/* # include <sys/ioctl.h> */
+# include <semaphore.h>
+# include <limits.h>
+#endif /* OS_VXWORKS */
+
+#if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
 # include <sys/mount.h>
 #endif
 
@@ -24560,8 +29278,8 @@ SQLITE_API int sqlite3_os_end(void){
 #endif
 
 /*
- ** Default permissions when creating auto proxy dir
- */
+** Default permissions when creating auto proxy dir
+*/
 #ifndef SQLITE_DEFAULT_PROXYDIR_PERMISSIONS
 # define SQLITE_DEFAULT_PROXYDIR_PERMISSIONS 0755
 #endif
@@ -24572,6 +29290,15 @@ SQLITE_API int sqlite3_os_end(void){
 #define MAX_PATHNAME 512
 
 /*
+** Maximum supported symbolic links
+*/
+#define SQLITE_MAX_SYMLINKS 100
+
+/* Always cast the getpid() return type for compatibility with
+** kernel modules in VxWorks. */
+#define osGetpid(X) (pid_t)getpid()
+
+/*
 ** Only set the lastErrno if the error code is a real error and not 
 ** a normal expected return code of SQLITE_BUSY or SQLITE_OK
 */
@@ -24602,16 +29329,28 @@ struct UnixUnusedFd {
 typedef struct unixFile unixFile;
 struct unixFile {
   sqlite3_io_methods const *pMethod;  /* Always the first entry */
+  sqlite3_vfs *pVfs;                  /* The VFS that created this unixFile */
   unixInodeInfo *pInode;              /* Info about locks on this inode */
   int h;                              /* The file descriptor */
   unsigned char eFileLock;            /* The type of lock held on this fd */
-  unsigned char ctrlFlags;            /* Behavioral bits.  UNIXFILE_* flags */
+  unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */
   int lastErrno;                      /* The unix errno from last I/O error */
   void *lockingContext;               /* Locking style specific state */
   UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
   const char *zPath;                  /* Name of the file */
   unixShm *pShm;                      /* Shared memory segment information */
   int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
+#if SQLITE_MAX_MMAP_SIZE>0
+  int nFetchOut;                      /* Number of outstanding xFetch refs */
+  sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */
+  sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */
+  sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */
+  void *pMapRegion;                   /* Memory mapped region */
+#endif
+#ifdef __QNXNTO__
+  int sectorSize;                     /* Device sector size */
+  int deviceCharacteristics;          /* Precomputed device characteristics */
+#endif
 #if SQLITE_ENABLE_LOCKING_STYLE
   int openFlags;                      /* The flags specified at open() */
 #endif
@@ -24619,10 +29358,9 @@ struct unixFile {
   unsigned fsFlags;                   /* cached details from statfs() */
 #endif
 #if OS_VXWORKS
-  int isDelete;                       /* Delete on close if true */
   struct vxworksFileId *pId;          /* Unique file ID */
 #endif
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
   /* The next group of variables are used to track whether or not the
   ** transaction counter in bytes 24-27 of database files are updated
   ** whenever any part of the database changes.  An assertion fault will
@@ -24633,7 +29371,9 @@ struct unixFile {
   unsigned char transCntrChng;   /* True if the transaction counter changed */
   unsigned char dbUpdate;        /* True if any part of database file changed */
   unsigned char inNormalWrite;   /* True if in a normal write operation */
+
 #endif
+
 #ifdef SQLITE_TEST
   /* In test mode, increase the size of this structure a bit so that 
   ** it is larger than the struct CrashFile defined in test6.c.
@@ -24642,6 +29382,12 @@ struct unixFile {
 #endif
 };
 
+/* This variable holds the process id (pid) from when the xRandomness()
+** method was called.  If xOpen() is called from a different process id,
+** indicating that a fork() has occurred, the PRNG will be reset.
+*/
+static pid_t randomnessPid = 0;
+
 /*
 ** Allowed values for the unixFile.ctrlFlags bitmask:
 */
@@ -24653,6 +29399,10 @@ struct unixFile {
 #else
 # define UNIXFILE_DIRSYNC    0x00
 #endif
+#define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
+#define UNIXFILE_DELETE      0x20     /* Delete on close */
+#define UNIXFILE_URI         0x40     /* Filename might have query parameters */
+#define UNIXFILE_NOLOCK      0x80     /* Do no file locking */
 
 /*
 ** Include code that is common to all os_*.c files
@@ -24690,24 +29440,14 @@ struct unixFile {
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
 /*
 ** Macros for performance tracing.  Normally turned off.  Only works
 ** on i486 hardware.
 */
 #ifdef SQLITE_PERFORMANCE_TRACE
 
-/* 
-** hwtime.h contains inline assembler code for implementing 
+/*
+** hwtime.h contains inline assembler code for implementing
 ** high-performance timing routines.
 */
 /************** Include hwtime.h in the middle of os_common.h ****************/
@@ -24727,8 +29467,8 @@ struct unixFile {
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -24796,7 +29536,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in os_common.h ******************/
@@ -24817,14 +29557,14 @@ static sqlite_uint64 g_elapsed;
 ** of code will give us the ability to simulate a disk I/O error.  This
 ** is used for testing the I/O recovery logic.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
 #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
 #define SimulateIOError(CODE)  \
   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
@@ -24850,17 +29590,17 @@ static void local_ioerr(){
 #define SimulateIOErrorBenign(X)
 #define SimulateIOError(A)
 #define SimulateDiskfullError(A)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** When testing, keep a count of the number of open files.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
 #define OpenCounter(X)  sqlite3_open_file_count+=(X)
 #else
 #define OpenCounter(X)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 #endif /* !defined(_OS_COMMON_H_) */
 
@@ -24895,6 +29635,25 @@ SQLITE_API int sqlite3_open_file_count = 0;
 #endif
 
 /*
+** HAVE_MREMAP defaults to true on Linux and false everywhere else.
+*/
+#if !defined(HAVE_MREMAP)
+# if defined(__linux__) && defined(_GNU_SOURCE)
+#  define HAVE_MREMAP 1
+# else
+#  define HAVE_MREMAP 0
+# endif
+#endif
+
+/*
+** Explicitly call the 64-bit version of lseek() on Android. Otherwise, lseek()
+** is the 32-bit version, even if _FILE_OFFSET_BITS=64 is defined.
+*/
+#ifdef __ANDROID__
+# define lseek lseek64
+#endif
+
+/*
 ** Different Unix systems declare open() in different ways.  Same use
 ** open(const char*,int,mode_t).  Others use open(const char*,int,...).
 ** The difference is important when using a pointer to the function.
@@ -24908,6 +29667,7 @@ static int posixOpen(const char *zFile, int flags, int mode){
 
 /* Forward reference */
 static int openDirectory(const char*, int*);
+static int unixGetpagesize(void);
 
 /*
 ** Many system calls are accessed through pointer-to-functions so that
@@ -24916,7 +29676,7 @@ static int openDirectory(const char*, int*);
 ** to all overrideable system calls.
 */
 static struct unix_syscall {
-  const char *zName;            /* Name of the sytem call */
+  const char *zName;            /* Name of the system call */
   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
   sqlite3_syscall_ptr pDefault; /* Default value */
 } aSyscall[] = {
@@ -24970,7 +29730,7 @@ static struct unix_syscall {
 #else
   { "pread64",      (sqlite3_syscall_ptr)0,          0  },
 #endif
-#define osPread64   ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[10].pCurrent)
+#define osPread64 ((ssize_t(*)(int,void*,size_t,off64_t))aSyscall[10].pCurrent)
 
   { "write",        (sqlite3_syscall_ptr)write,      0  },
 #define osWrite     ((ssize_t(*)(int,const void*,size_t))aSyscall[11].pCurrent)
@@ -24988,14 +29748,10 @@ static struct unix_syscall {
 #else
   { "pwrite64",     (sqlite3_syscall_ptr)0,          0  },
 #endif
-#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
+#define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off64_t))\
                     aSyscall[13].pCurrent)
 
-#if SQLITE_ENABLE_LOCKING_STYLE
-  { "fchmod",       (sqlite3_syscall_ptr)fchmod,     0  },
-#else
-  { "fchmod",       (sqlite3_syscall_ptr)0,          0  },
-#endif
+  { "fchmod",       (sqlite3_syscall_ptr)fchmod,          0  },
 #define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)
 
 #if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
@@ -25011,8 +29767,80 @@ static struct unix_syscall {
   { "openDirectory",    (sqlite3_syscall_ptr)openDirectory,      0 },
 #define osOpenDirectory ((int(*)(const char*,int*))aSyscall[17].pCurrent)
 
+  { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },
+#define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)
+
+  { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },
+#define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)
+
+#if defined(HAVE_FCHOWN)
+  { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },
+#else
+  { "fchown",       (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)
+
+  { "geteuid",      (sqlite3_syscall_ptr)geteuid,         0 },
+#define osGeteuid   ((uid_t(*)(void))aSyscall[21].pCurrent)
+
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+  { "mmap",         (sqlite3_syscall_ptr)mmap,            0 },
+#else
+  { "mmap",         (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)
+
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+  { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },
+#else
+  { "munmap",       (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMunmap ((void*(*)(void*,size_t))aSyscall[23].pCurrent)
+
+#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
+  { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },
+#else
+  { "mremap",       (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)
+
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+  { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },
+#else
+  { "getpagesize",  (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osGetpagesize ((int(*)(void))aSyscall[25].pCurrent)
+
+#if defined(HAVE_READLINK)
+  { "readlink",     (sqlite3_syscall_ptr)readlink,        0 },
+#else
+  { "readlink",     (sqlite3_syscall_ptr)0,               0 },
+#endif
+#define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)
+
+#if defined(HAVE_LSTAT)
+  { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },
+#else
+  { "lstat",         (sqlite3_syscall_ptr)0,              0 },
+#endif
+#define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)
+
 }; /* End of the overrideable system calls */
 
+
+/*
+** On some systems, calls to fchown() will trigger a message in a security
+** log if they come from non-root processes.  So avoid calling fchown() if
+** we are not running as root.
+*/
+static int robustFchown(int fd, uid_t uid, gid_t gid){
+#if defined(HAVE_FCHOWN)
+  return osGeteuid() ? 0 : osFchown(fd,uid,gid);
+#else
+  return 0;
+#endif
+}
+
 /*
 ** This is the xSetSystemCall() method of sqlite3_vfs for all of the
 ** "unix" VFSes.  Return SQLITE_OK opon successfully updating the
@@ -25097,12 +29925,66 @@ static const char *unixNextSystemCall(sqlite3_vfs *p, const char *zName){
 }
 
 /*
-** Retry open() calls that fail due to EINTR
+** Do not accept any file descriptor less than this value, in order to avoid
+** opening database file using file descriptors that are commonly used for 
+** standard input, output, and error.
 */
-static int robust_open(const char *z, int f, int m){
-  int rc;
-  do{ rc = osOpen(z,f,m); }while( rc<0 && errno==EINTR );
-  return rc;
+#ifndef SQLITE_MINIMUM_FILE_DESCRIPTOR
+# define SQLITE_MINIMUM_FILE_DESCRIPTOR 3
+#endif
+
+/*
+** Invoke open().  Do so multiple times, until it either succeeds or
+** fails for some reason other than EINTR.
+**
+** If the file creation mode "m" is 0 then set it to the default for
+** SQLite.  The default is SQLITE_DEFAULT_FILE_PERMISSIONS (normally
+** 0644) as modified by the system umask.  If m is not 0, then
+** make the file creation mode be exactly m ignoring the umask.
+**
+** The m parameter will be non-zero only when creating -wal, -journal,
+** and -shm files.  We want those files to have *exactly* the same
+** permissions as their original database, unadulterated by the umask.
+** In that way, if a database file is -rw-rw-rw or -rw-rw-r-, and a
+** transaction crashes and leaves behind hot journals, then any
+** process that is able to write to the database will also be able to
+** recover the hot journals.
+*/
+static int robust_open(const char *z, int f, mode_t m){
+  int fd;
+  mode_t m2 = m ? m : SQLITE_DEFAULT_FILE_PERMISSIONS;
+  while(1){
+#if defined(O_CLOEXEC)
+    fd = osOpen(z,f|O_CLOEXEC,m2);
+#else
+    fd = osOpen(z,f,m2);
+#endif
+    if( fd<0 ){
+      if( errno==EINTR ) continue;
+      break;
+    }
+    if( fd>=SQLITE_MINIMUM_FILE_DESCRIPTOR ) break;
+    osClose(fd);
+    sqlite3_log(SQLITE_WARNING, 
+                "attempt to open \"%s\" as file descriptor %d", z, fd);
+    fd = -1;
+    if( osOpen("/dev/null", f, m)<0 ) break;
+  }
+  if( fd>=0 ){
+    if( m!=0 ){
+      struct stat statbuf;
+      if( osFstat(fd, &statbuf)==0 
+       && statbuf.st_size==0
+       && (statbuf.st_mode&0777)!=m 
+      ){
+        osFchmod(fd, m);
+      }
+    }
+#if defined(FD_CLOEXEC) && (!defined(O_CLOEXEC) || O_CLOEXEC==0)
+    osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
+#endif
+  }
+  return fd;
 }
 
 /*
@@ -25120,22 +30002,22 @@ static int robust_open(const char *z, int f, int m){
 **   unixEnterLeave()
 */
 static void unixEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 static void unixLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #ifdef SQLITE_DEBUG
 static int unixMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #endif
 
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
+#ifdef SQLITE_HAVE_OS_TRACE
 /*
 ** Helper function for printing out trace information from debugging
-** binaries. This returns the string represetation of the supplied
+** binaries. This returns the string representation of the supplied
 ** integer lock-type.
 */
 static const char *azFileLock(int eFileLock){
@@ -25212,9 +30094,22 @@ static int lockTrace(int fd, int op, struct flock *p){
 
 /*
 ** Retry ftruncate() calls that fail due to EINTR
+**
+** All calls to ftruncate() within this file should be made through
+** this wrapper.  On the Android platform, bypassing the logic below
+** could lead to a corrupt database.
 */
 static int robust_ftruncate(int h, sqlite3_int64 sz){
   int rc;
+#ifdef __ANDROID__
+  /* On Android, ftruncate() always uses 32-bit offsets, even if 
+  ** _FILE_OFFSET_BITS=64 is defined. This means it is unsafe to attempt to
+  ** truncate a file to any size larger than 2GiB. Silently ignore any
+  ** such attempts.  */
+  if( sz>(sqlite3_int64)0x7FFFFFFF ){
+    rc = SQLITE_OK;
+  }else
+#endif
   do{ rc = osFtruncate(h,sz); }while( rc<0 && errno==EINTR );
   return rc;
 }
@@ -25230,23 +30125,12 @@ static int robust_ftruncate(int h, sqlite3_int64 sz){
 ** should handle ENOLCK, ENOTSUP, EOPNOTSUPP separately.
 */
 static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
+  assert( (sqliteIOErr == SQLITE_IOERR_LOCK) || 
+          (sqliteIOErr == SQLITE_IOERR_UNLOCK) || 
+          (sqliteIOErr == SQLITE_IOERR_RDLOCK) ||
+          (sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) );
   switch (posixError) {
-#if 0
-  /* At one point this code was not commented out. In theory, this branch
-  ** should never be hit, as this function should only be called after
-  ** a locking-related function (i.e. fcntl()) has returned non-zero with
-  ** the value of errno as the first argument. Since a system call has failed,
-  ** errno should be non-zero.
-  **
-  ** Despite this, if errno really is zero, we still don't want to return
-  ** SQLITE_OK. The system call failed, and *some* SQLite error should be
-  ** propagated back to the caller. Commenting this branch out means errno==0
-  ** will be handled by the "default:" case below.
-  */
-  case 0: 
-    return SQLITE_OK;
-#endif
-
+  case EACCES: 
   case EAGAIN:
   case ETIMEDOUT:
   case EBUSY:
@@ -25256,58 +30140,15 @@ static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {
      * introspection, in which it actually means what it says */
     return SQLITE_BUSY;
     
-  case EACCES: 
-    /* EACCES is like EAGAIN during locking operations, but not any other time*/
-    if( (sqliteIOErr == SQLITE_IOERR_LOCK) || 
-	(sqliteIOErr == SQLITE_IOERR_UNLOCK) || 
-	(sqliteIOErr == SQLITE_IOERR_RDLOCK) ||
-	(sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) ){
-      return SQLITE_BUSY;
-    }
-    /* else fall through */
   case EPERM: 
     return SQLITE_PERM;
     
-  /* EDEADLK is only possible if a call to fcntl(F_SETLKW) is made. And
-  ** this module never makes such a call. And the code in SQLite itself 
-  ** asserts that SQLITE_IOERR_BLOCKED is never returned. For these reasons
-  ** this case is also commented out. If the system does set errno to EDEADLK,
-  ** the default SQLITE_IOERR_XXX code will be returned. */
-#if 0
-  case EDEADLK:
-    return SQLITE_IOERR_BLOCKED;
-#endif
-    
-#if EOPNOTSUPP!=ENOTSUP
-  case EOPNOTSUPP: 
-    /* something went terribly awry, unless during file system support 
-     * introspection, in which it actually means what it says */
-#endif
-#ifdef ENOTSUP
-  case ENOTSUP: 
-    /* invalid fd, unless during file system support introspection, in which 
-     * it actually means what it says */
-#endif
-  case EIO:
-  case EBADF:
-  case EINVAL:
-  case ENOTCONN:
-  case ENODEV:
-  case ENXIO:
-  case ENOENT:
-#ifdef ESTALE                     /* ESTALE is not defined on Interix systems */
-  case ESTALE:
-#endif
-  case ENOSYS:
-    /* these should force the client to close the file and reconnect */
-    
   default: 
     return sqliteIOErr;
   }
 }
 
 
-
 /******************************************************************************
 ****************** Begin Unique File ID Utility Used By VxWorks ***************
 **
@@ -25393,7 +30234,7 @@ static struct vxworksFileId *vxworksFindFileId(const char *zAbsoluteName){
 
   assert( zAbsoluteName[0]=='/' );
   n = (int)strlen(zAbsoluteName);
-  pNew = sqlite3_malloc( sizeof(*pNew) + (n+1) );
+  pNew = sqlite3_malloc64( sizeof(*pNew) + (n+1) );
   if( pNew==0 ) return 0;
   pNew->zCanonicalName = (char*)&pNew[1];
   memcpy(pNew->zCanonicalName, zAbsoluteName, n+1);
@@ -25585,7 +30426,7 @@ static unixInodeInfo *inodeList = 0;
 
 /*
 **
-** This function - unixLogError_x(), is only ever called via the macro
+** This function - unixLogErrorAtLine(), is only ever called via the macro
 ** unixLogError().
 **
 ** It is invoked after an error occurs in an OS function and errno has been
@@ -25596,7 +30437,7 @@ static unixInodeInfo *inodeList = 0;
 ** The first argument passed to the macro should be the error code that
 ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN). 
 ** The two subsequent arguments should be the name of the OS function that
-** failed (e.g. "unlink", "open") and the the associated file-system path,
+** failed (e.g. "unlink", "open") and the associated file-system path,
 ** if any.
 */
 #define unixLogError(a,b,c)     unixLogErrorAtLine(a,b,c,__LINE__)
@@ -25619,7 +30460,7 @@ static int unixLogErrorAtLine(
   zErr = aErr;
 
   /* If STRERROR_R_CHAR_P (set by autoconf scripts) or __USE_GNU is defined,
-  ** assume that the system provides the the GNU version of strerror_r() that 
+  ** assume that the system provides the GNU version of strerror_r() that
   ** returns a pointer to a buffer containing the error message. That pointer 
   ** may point to aErr[], or it may point to some static storage somewhere. 
   ** Otherwise, assume that the system provides the POSIX version of 
@@ -25643,7 +30484,6 @@ static int unixLogErrorAtLine(
   zErr = strerror(iErrno);
 #endif
 
-  assert( errcode!=SQLITE_OK );
   if( zPath==0 ) zPath = "";
   sqlite3_log(errcode,
       "os_unix.c:%d: (%d) %s(%s) - %s",
@@ -25674,6 +30514,14 @@ static void robust_close(unixFile *pFile, int h, int lineno){
 }
 
 /*
+** Set the pFile->lastErrno.  Do this in a subroutine as that provides
+** a convenient place to set a breakpoint.
+*/
+static void storeLastErrno(unixFile *pFile, int error){
+  pFile->lastErrno = error;
+}
+
+/*
 ** Close all file descriptors accumuated in the unixInodeInfo->pUnused list.
 */ 
 static void closePendingFds(unixFile *pFile){
@@ -25746,8 +30594,8 @@ static int findInodeInfo(
   fd = pFile->h;
   rc = osFstat(fd, &statbuf);
   if( rc!=0 ){
-    pFile->lastErrno = errno;
-#ifdef EOVERFLOW
+    storeLastErrno(pFile, errno);
+#if defined(EOVERFLOW) && defined(SQLITE_DISABLE_LFS)
     if( pFile->lastErrno==EOVERFLOW ) return SQLITE_NOLFS;
 #endif
     return SQLITE_IOERR;
@@ -25767,12 +30615,12 @@ static int findInodeInfo(
   if( statbuf.st_size==0 && (pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS)!=0 ){
     do{ rc = osWrite(fd, "S", 1); }while( rc<0 && errno==EINTR );
     if( rc!=1 ){
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       return SQLITE_IOERR;
     }
     rc = osFstat(fd, &statbuf);
     if( rc!=0 ){
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       return SQLITE_IOERR;
     }
   }
@@ -25790,9 +30638,9 @@ static int findInodeInfo(
     pInode = pInode->pNext;
   }
   if( pInode==0 ){
-    pInode = sqlite3_malloc( sizeof(*pInode) );
+    pInode = sqlite3_malloc64( sizeof(*pInode) );
     if( pInode==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset(pInode, 0, sizeof(*pInode));
     memcpy(&pInode->fileId, &fileId, sizeof(fileId));
@@ -25808,6 +30656,55 @@ static int findInodeInfo(
   return SQLITE_OK;
 }
 
+/*
+** Return TRUE if pFile has been renamed or unlinked since it was first opened.
+*/
+static int fileHasMoved(unixFile *pFile){
+#if OS_VXWORKS
+  return pFile->pInode!=0 && pFile->pId!=pFile->pInode->fileId.pId;
+#else
+  struct stat buf;
+  return pFile->pInode!=0 &&
+      (osStat(pFile->zPath, &buf)!=0 || buf.st_ino!=pFile->pInode->fileId.ino);
+#endif
+}
+
+
+/*
+** Check a unixFile that is a database.  Verify the following:
+**
+** (1) There is exactly one hard link on the file
+** (2) The file is not a symbolic link
+** (3) The file has not been renamed or unlinked
+**
+** Issue sqlite3_log(SQLITE_WARNING,...) messages if anything is not right.
+*/
+static void verifyDbFile(unixFile *pFile){
+  struct stat buf;
+  int rc;
+
+  /* These verifications occurs for the main database only */
+  if( pFile->ctrlFlags & UNIXFILE_NOLOCK ) return;
+
+  rc = osFstat(pFile->h, &buf);
+  if( rc!=0 ){
+    sqlite3_log(SQLITE_WARNING, "cannot fstat db file %s", pFile->zPath);
+    return;
+  }
+  if( buf.st_nlink==0 ){
+    sqlite3_log(SQLITE_WARNING, "file unlinked while open: %s", pFile->zPath);
+    return;
+  }
+  if( buf.st_nlink>1 ){
+    sqlite3_log(SQLITE_WARNING, "multiple links to file: %s", pFile->zPath);
+    return;
+  }
+  if( fileHasMoved(pFile) ){
+    sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);
+    return;
+  }
+}
+
 
 /*
 ** This routine checks if there is a RESERVED lock held on the specified
@@ -25823,6 +30720,7 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
 
   assert( pFile );
+  assert( pFile->eFileLock<=SHARED_LOCK );
   unixEnterMutex(); /* Because pFile->pInode is shared across threads */
 
   /* Check if a thread in this process holds such a lock */
@@ -25841,7 +30739,7 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
     lock.l_type = F_WRLCK;
     if( osFcntl(pFile->h, F_GETLK, &lock) ){
       rc = SQLITE_IOERR_CHECKRESERVEDLOCK;
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
     } else if( lock.l_type!=F_UNLCK ){
       reserved = 1;
     }
@@ -25879,9 +30777,7 @@ static int unixFileLock(unixFile *pFile, struct flock *pLock){
   unixInodeInfo *pInode = pFile->pInode;
   assert( unixMutexHeld() );
   assert( pInode!=0 );
-  if( ((pFile->ctrlFlags & UNIXFILE_EXCL)!=0 || pInode->bProcessLock)
-   && ((pFile->ctrlFlags & UNIXFILE_RDONLY)==0)
-  ){
+  if( (pFile->ctrlFlags & (UNIXFILE_EXCL|UNIXFILE_RDONLY))==UNIXFILE_EXCL ){
     if( pInode->bProcessLock==0 ){
       struct flock lock;
       assert( pInode->nLock==0 );
@@ -25931,7 +30827,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** lock transitions in terms of the POSIX advisory shared and exclusive
   ** lock primitives (called read-locks and write-locks below, to avoid
   ** confusion with SQLite lock names). The algorithms are complicated
-  ** slightly in order to be compatible with windows systems simultaneously
+  ** slightly in order to be compatible with Windows95 systems simultaneously
   ** accessing the same database file, in case that is ever required.
   **
   ** Symbols defined in os.h indentify the 'pending byte' and the 'reserved
@@ -25939,8 +30835,14 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** range', a range of 510 bytes at a well known offset.
   **
   ** To obtain a SHARED lock, a read-lock is obtained on the 'pending
-  ** byte'.  If this is successful, a random byte from the 'shared byte
-  ** range' is read-locked and the lock on the 'pending byte' released.
+  ** byte'.  If this is successful, 'shared byte range' is read-locked
+  ** and the lock on the 'pending byte' released.  (Legacy note:  When
+  ** SQLite was first developed, Windows95 systems were still very common,
+  ** and Widnows95 lacks a shared-lock capability.  So on Windows95, a
+  ** single randomly selected by from the 'shared byte range' is locked.
+  ** Windows95 is now pretty much extinct, but this work-around for the
+  ** lack of shared-locks on Windows95 lives on, for backwards
+  ** compatibility.)
   **
   ** A process may only obtain a RESERVED lock after it has a SHARED lock.
   ** A RESERVED lock is implemented by grabbing a write-lock on the
@@ -25959,11 +30861,6 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   ** range'. Since all other locks require a read-lock on one of the bytes
   ** within this range, this ensures that no other locks are held on the
   ** database. 
-  **
-  ** The reason a single byte cannot be used instead of the 'shared byte
-  ** range' is that some versions of windows do not support read-locks. By
-  ** locking a random byte from a range, concurrent SHARED locks may exist
-  ** even if the locking primitive used is always a write-lock.
   */
   int rc = SQLITE_OK;
   unixFile *pFile = (unixFile*)id;
@@ -25974,7 +30871,8 @@ static int unixLock(sqlite3_file *id, int eFileLock){
   assert( pFile );
   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (unix)\n", pFile->h,
       azFileLock(eFileLock), azFileLock(pFile->eFileLock),
-      azFileLock(pFile->pInode->eFileLock), pFile->pInode->nShared , getpid()));
+      azFileLock(pFile->pInode->eFileLock), pFile->pInode->nShared,
+      osGetpid(0)));
 
   /* If there is already a lock of this type or more restrictive on the
   ** unixFile, do nothing. Don't use the end_lock: exit path, as
@@ -26041,7 +30939,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
       tErrno = errno;
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
       goto end_lock;
     }
@@ -26076,7 +30974,7 @@ static int unixLock(sqlite3_file *id, int eFileLock){
 
     if( rc ){
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
       goto end_lock;
     }else{
@@ -26109,13 +31007,13 @@ static int unixLock(sqlite3_file *id, int eFileLock){
       tErrno = errno;
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
       if( rc!=SQLITE_BUSY ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       }
     }
   }
   
 
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
   /* Set up the transaction-counter change checking flags when
   ** transitioning from a SHARED to a RESERVED lock.  The change
   ** from SHARED to RESERVED marks the beginning of a normal
@@ -26182,7 +31080,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (unix)\n", pFile->h, eFileLock,
       pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,
-      getpid()));
+      osGetpid(0)));
 
   assert( eFileLock<=SHARED_LOCK );
   if( pFile->eFileLock<=eFileLock ){
@@ -26194,7 +31092,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
   if( pFile->eFileLock>SHARED_LOCK ){
     assert( pInode->eFileLock==pFile->eFileLock );
 
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
     /* When reducing a lock such that other processes can start
     ** reading the database file again, make sure that the
     ** transaction counter was updated if any part of the database
@@ -26216,7 +31114,6 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
     **  4:   [RRRR.]
     */
     if( eFileLock==SHARED_LOCK ){
-
 #if !defined(__APPLE__) || !SQLITE_ENABLE_LOCKING_STYLE
       (void)handleNFSUnlock;
       assert( handleNFSUnlock==0 );
@@ -26233,9 +31130,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         if( unixFileLock(pFile, &lock)==(-1) ){
           tErrno = errno;
           rc = SQLITE_IOERR_UNLOCK;
-          if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
-          }
+          storeLastErrno(pFile, tErrno);
           goto end_unlock;
         }
         lock.l_type = F_RDLCK;
@@ -26246,7 +31141,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
           tErrno = errno;
           rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_RDLOCK);
           if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
+            storeLastErrno(pFile, tErrno);
           }
           goto end_unlock;
         }
@@ -26257,9 +31152,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         if( unixFileLock(pFile, &lock)==(-1) ){
           tErrno = errno;
           rc = SQLITE_IOERR_UNLOCK;
-          if( IS_LOCK_ERROR(rc) ){
-            pFile->lastErrno = tErrno;
-          }
+          storeLastErrno(pFile, tErrno);
           goto end_unlock;
         }
       }else
@@ -26277,7 +31170,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
           ** SQLITE_BUSY would confuse the upper layer (in practice it causes 
           ** an assert to fail). */ 
           rc = SQLITE_IOERR_RDLOCK;
-          pFile->lastErrno = errno;
+          storeLastErrno(pFile, errno);
           goto end_unlock;
         }
       }
@@ -26290,7 +31183,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
       pInode->eFileLock = SHARED_LOCK;
     }else{
       rc = SQLITE_IOERR_UNLOCK;
-      pFile->lastErrno = errno;
+      storeLastErrno(pFile, errno);
       goto end_unlock;
     }
   }
@@ -26308,7 +31201,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
         pInode->eFileLock = NO_LOCK;
       }else{
         rc = SQLITE_IOERR_UNLOCK;
-	pFile->lastErrno = errno;
+        storeLastErrno(pFile, errno);
         pInode->eFileLock = NO_LOCK;
         pFile->eFileLock = NO_LOCK;
       }
@@ -26324,7 +31217,7 @@ static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){
       closePendingFds(pFile);
     }
   }
-	
+
 end_unlock:
   unixLeaveMutex();
   if( rc==SQLITE_OK ) pFile->eFileLock = eFileLock;
@@ -26339,9 +31232,17 @@ end_unlock:
 ** the requested locking level, this routine is a no-op.
 */
 static int unixUnlock(sqlite3_file *id, int eFileLock){
+#if SQLITE_MAX_MMAP_SIZE>0
+  assert( eFileLock==SHARED_LOCK || ((unixFile *)id)->nFetchOut==0 );
+#endif
   return posixUnlock(id, eFileLock, 0);
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+static int unixMapfile(unixFile *pFd, i64 nByte);
+static void unixUnmapfile(unixFile *pFd);
+#endif
+
 /*
 ** This function performs the parts of the "close file" operation 
 ** common to all locking schemes. It closes the directory and file
@@ -26354,19 +31255,29 @@ static int unixUnlock(sqlite3_file *id, int eFileLock){
 */
 static int closeUnixFile(sqlite3_file *id){
   unixFile *pFile = (unixFile*)id;
+#if SQLITE_MAX_MMAP_SIZE>0
+  unixUnmapfile(pFile);
+#endif
   if( pFile->h>=0 ){
     robust_close(pFile, pFile->h, __LINE__);
     pFile->h = -1;
   }
 #if OS_VXWORKS
   if( pFile->pId ){
-    if( pFile->isDelete ){
+    if( pFile->ctrlFlags & UNIXFILE_DELETE ){
       osUnlink(pFile->pId->zCanonicalName);
     }
     vxworksReleaseFileId(pFile->pId);
     pFile->pId = 0;
   }
 #endif
+#ifdef SQLITE_UNLINK_AFTER_CLOSE
+  if( pFile->ctrlFlags & UNIXFILE_DELETE ){
+    osUnlink(pFile->zPath);
+    sqlite3_free(*(char**)&pFile->zPath);
+    pFile->zPath = 0;
+  }
+#endif
   OSTRACE(("CLOSE   %-3d\n", pFile->h));
   OpenCounter(-1);
   sqlite3_free(pFile->pUnused);
@@ -26380,6 +31291,7 @@ static int closeUnixFile(sqlite3_file *id){
 static int unixClose(sqlite3_file *id){
   int rc = SQLITE_OK;
   unixFile *pFile = (unixFile *)id;
+  verifyDbFile(pFile);
   unixUnlock(id, NO_LOCK);
   unixEnterMutex();
 
@@ -26448,9 +31360,9 @@ static int nolockClose(sqlite3_file *id) {
 /******************************************************************************
 ************************* Begin dot-file Locking ******************************
 **
-** The dotfile locking implementation uses the existance of separate lock
-** files in order to control access to the database.  This works on just
-** about every filesystem imaginable.  But there are serious downsides:
+** The dotfile locking implementation uses the existence of separate lock
+** files (really a directory) to control access to the database.  This works
+** on just about every filesystem imaginable.  But there are serious downsides:
 **
 **    (1)  There is zero concurrency.  A single reader blocks all other
 **         connections from reading or writing the database.
@@ -26461,15 +31373,15 @@ static int nolockClose(sqlite3_file *id) {
 ** Nevertheless, a dotlock is an appropriate locking mode for use if no
 ** other locking strategy is available.
 **
-** Dotfile locking works by creating a file in the same directory as the
-** database and with the same name but with a ".lock" extension added.
-** The existance of a lock file implies an EXCLUSIVE lock.  All other lock
-** types (SHARED, RESERVED, PENDING) are mapped into EXCLUSIVE.
+** Dotfile locking works by creating a subdirectory in the same directory as
+** the database and with the same name but with a ".lock" extension added.
+** The existence of a lock directory implies an EXCLUSIVE lock.  All other
+** lock types (SHARED, RESERVED, PENDING) are mapped into EXCLUSIVE.
 */
 
 /*
 ** The file suffix added to the data base filename in order to create the
-** lock file.
+** lock directory.
 */
 #define DOTLOCK_SUFFIX ".lock"
 
@@ -26491,17 +31403,7 @@ static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
   
   assert( pFile );
-
-  /* Check if a thread in this process holds such a lock */
-  if( pFile->eFileLock>SHARED_LOCK ){
-    /* Either this connection or some other connection in the same process
-    ** holds a lock on the file.  No need to check further. */
-    reserved = 1;
-  }else{
-    /* The lock is held if and only if the lockfile exists */
-    const char *zLockFile = (const char*)pFile->lockingContext;
-    reserved = osAccess(zLockFile, 0)==0;
-  }
+  reserved = osAccess((const char*)pFile->lockingContext, 0)==0;
   OSTRACE(("TEST WR-LOCK %d %d %d (dotlock)\n", pFile->h, rc, reserved));
   *pResOut = reserved;
   return rc;
@@ -26536,7 +31438,6 @@ static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {
 */
 static int dotlockLock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
-  int fd;
   char *zLockFile = (char *)pFile->lockingContext;
   int rc = SQLITE_OK;
 
@@ -26556,21 +31457,20 @@ static int dotlockLock(sqlite3_file *id, int eFileLock) {
   }
   
   /* grab an exclusive lock */
-  fd = robust_open(zLockFile,O_RDONLY|O_CREAT|O_EXCL,0600);
-  if( fd<0 ){
-    /* failed to open/create the file, someone else may have stolen the lock */
+  rc = osMkdir(zLockFile, 0777);
+  if( rc<0 ){
+    /* failed to open/create the lock directory */
     int tErrno = errno;
     if( EEXIST == tErrno ){
       rc = SQLITE_BUSY;
     } else {
       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
-      if( IS_LOCK_ERROR(rc) ){
-        pFile->lastErrno = tErrno;
+      if( rc!=SQLITE_BUSY ){
+        storeLastErrno(pFile, tErrno);
       }
     }
     return rc;
   } 
-  robust_close(pFile, fd, __LINE__);
   
   /* got it, set the type and return ok */
   pFile->eFileLock = eFileLock;
@@ -26589,10 +31489,11 @@ static int dotlockLock(sqlite3_file *id, int eFileLock) {
 static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
   char *zLockFile = (char *)pFile->lockingContext;
+  int rc;
 
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (dotlock)\n", pFile->h, eFileLock,
-	   pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -26610,14 +31511,14 @@ static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
   
   /* To fully unlock the database, delete the lock file */
   assert( eFileLock==NO_LOCK );
-  if( osUnlink(zLockFile) ){
-    int rc = 0;
+  rc = osRmdir(zLockFile);
+  if( rc<0 ){
     int tErrno = errno;
-    if( ENOENT != tErrno ){
+    if( tErrno==ENOENT ){
+      rc = SQLITE_OK;
+    }else{
       rc = SQLITE_IOERR_UNLOCK;
-    }
-    if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc; 
   }
@@ -26629,14 +31530,11 @@ static int dotlockUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file.  Make sure the lock has been released before closing.
 */
 static int dotlockClose(sqlite3_file *id) {
-  int rc;
-  if( id ){
-    unixFile *pFile = (unixFile*)id;
-    dotlockUnlock(id, NO_LOCK);
-    sqlite3_free(pFile->lockingContext);
-  }
-  rc = closeUnixFile(id);
-  return rc;
+  unixFile *pFile = (unixFile*)id;
+  assert( id!=0 );
+  dotlockUnlock(id, NO_LOCK);
+  sqlite3_free(pFile->lockingContext);
+  return closeUnixFile(id);
 }
 /****************** End of the dot-file lock implementation *******************
 ******************************************************************************/
@@ -26653,10 +31551,9 @@ static int dotlockClose(sqlite3_file *id) {
 ** still works when you do this, but concurrency is reduced since
 ** only a single process can be reading the database at a time.
 **
-** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off or if
-** compiling for VXWORKS.
+** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off
 */
-#if SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE
 
 /*
 ** Retry flock() calls that fail with EINTR
@@ -26703,10 +31600,8 @@ static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){
         int tErrno = errno;
         /* unlock failed with an error */
         lrc = SQLITE_IOERR_UNLOCK; 
-        if( IS_LOCK_ERROR(lrc) ){
-          pFile->lastErrno = tErrno;
-          rc = lrc;
-        }
+        storeLastErrno(pFile, tErrno);
+        rc = lrc;
       }
     } else {
       int tErrno = errno;
@@ -26714,7 +31609,7 @@ static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){
       /* someone else might have it reserved */
       lrc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK); 
       if( IS_LOCK_ERROR(lrc) ){
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
         rc = lrc;
       }
     }
@@ -26780,7 +31675,7 @@ static int flockLock(sqlite3_file *id, int eFileLock) {
     /* didn't get, must be busy */
     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
   } else {
     /* got it, set the type and return ok */
@@ -26809,7 +31704,7 @@ static int flockUnlock(sqlite3_file *id, int eFileLock) {
   
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (flock)\n", pFile->h, eFileLock,
-           pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -26839,9 +31734,8 @@ static int flockUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file.
 */
 static int flockClose(sqlite3_file *id) {
-  if( id ){
-    flockUnlock(id, NO_LOCK);
-  }
+  assert( id!=0 );
+  flockUnlock(id, NO_LOCK);
   return closeUnixFile(id);
 }
 
@@ -26868,7 +31762,7 @@ static int flockClose(sqlite3_file *id) {
 ** to a non-zero value otherwise *pResOut is set to zero.  The return value
 ** is set to SQLITE_OK unless an I/O error occurs during lock checking.
 */
-static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
+static int semXCheckReservedLock(sqlite3_file *id, int *pResOut) {
   int rc = SQLITE_OK;
   int reserved = 0;
   unixFile *pFile = (unixFile*)id;
@@ -26885,13 +31779,12 @@ static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
   /* Otherwise see if some other process holds it. */
   if( !reserved ){
     sem_t *pSem = pFile->pInode->pSem;
-    struct stat statBuf;
 
     if( sem_trywait(pSem)==-1 ){
       int tErrno = errno;
       if( EAGAIN != tErrno ){
         rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_CHECKRESERVEDLOCK);
-        pFile->lastErrno = tErrno;
+        storeLastErrno(pFile, tErrno);
       } else {
         /* someone else has the lock when we are in NO_LOCK */
         reserved = (pFile->eFileLock < SHARED_LOCK);
@@ -26936,9 +31829,8 @@ static int semCheckReservedLock(sqlite3_file *id, int *pResOut) {
 ** This routine will only increase a lock.  Use the sqlite3OsUnlock()
 ** routine to lower a locking level.
 */
-static int semLock(sqlite3_file *id, int eFileLock) {
+static int semXLock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
-  int fd;
   sem_t *pSem = pFile->pInode->pSem;
   int rc = SQLITE_OK;
 
@@ -26970,14 +31862,14 @@ static int semLock(sqlite3_file *id, int eFileLock) {
 ** If the locking level of the file descriptor is already at or below
 ** the requested locking level, this routine is a no-op.
 */
-static int semUnlock(sqlite3_file *id, int eFileLock) {
+static int semXUnlock(sqlite3_file *id, int eFileLock) {
   unixFile *pFile = (unixFile*)id;
   sem_t *pSem = pFile->pInode->pSem;
 
   assert( pFile );
   assert( pSem );
   OSTRACE(("UNLOCK  %d %d was %d pid=%d (sem)\n", pFile->h, eFileLock,
-	   pFile->eFileLock, getpid()));
+           pFile->eFileLock, osGetpid(0)));
   assert( eFileLock<=SHARED_LOCK );
   
   /* no-op if possible */
@@ -26996,7 +31888,7 @@ static int semUnlock(sqlite3_file *id, int eFileLock) {
     int rc, tErrno = errno;
     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc; 
   }
@@ -27007,10 +31899,10 @@ static int semUnlock(sqlite3_file *id, int eFileLock) {
 /*
  ** Close a file.
  */
-static int semClose(sqlite3_file *id) {
+static int semXClose(sqlite3_file *id) {
   if( id ){
     unixFile *pFile = (unixFile*)id;
-    semUnlock(id, NO_LOCK);
+    semXUnlock(id, NO_LOCK);
     assert( pFile );
     unixEnterMutex();
     releaseInodeInfo(pFile);
@@ -27098,7 +31990,7 @@ static int afpSetLock(
                     setLockFlag ? SQLITE_IOERR_LOCK : SQLITE_IOERR_UNLOCK);
 #endif /* SQLITE_IGNORE_AFP_LOCK_ERRORS */
     if( IS_LOCK_ERROR(rc) ){
-      pFile->lastErrno = tErrno;
+      storeLastErrno(pFile, tErrno);
     }
     return rc;
   } else {
@@ -27191,7 +32083,7 @@ static int afpLock(sqlite3_file *id, int eFileLock){
   assert( pFile );
   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (afp)\n", pFile->h,
            azFileLock(eFileLock), azFileLock(pFile->eFileLock),
-           azFileLock(pInode->eFileLock), pInode->nShared , getpid()));
+           azFileLock(pInode->eFileLock), pInode->nShared , osGetpid(0)));
 
   /* If there is already a lock of this type or more restrictive on the
   ** unixFile, do nothing. Don't use the afp_end_lock: exit path, as
@@ -27281,7 +32173,7 @@ static int afpLock(sqlite3_file *id, int eFileLock){
     lrc2 = afpSetLock(context->dbPath, pFile, PENDING_BYTE, 1, 0);
     
     if( IS_LOCK_ERROR(lrc1) ) {
-      pFile->lastErrno = lrc1Errno;
+      storeLastErrno(pFile, lrc1Errno);
       rc = lrc1;
       goto afp_end_lock;
     } else if( IS_LOCK_ERROR(lrc2) ){
@@ -27377,7 +32269,7 @@ static int afpUnlock(sqlite3_file *id, int eFileLock) {
   assert( pFile );
   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (afp)\n", pFile->h, eFileLock,
            pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,
-           getpid()));
+           osGetpid(0)));
 
   assert( eFileLock<=SHARED_LOCK );
   if( pFile->eFileLock<=eFileLock ){
@@ -27392,7 +32284,7 @@ static int afpUnlock(sqlite3_file *id, int eFileLock) {
     SimulateIOError( h=(-1) )
     SimulateIOErrorBenign(0);
     
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
     /* When reducing a lock such that other processes can start
     ** reading the database file again, make sure that the
     ** transaction counter was updated if any part of the database
@@ -27469,23 +32361,22 @@ static int afpUnlock(sqlite3_file *id, int eFileLock) {
 */
 static int afpClose(sqlite3_file *id) {
   int rc = SQLITE_OK;
-  if( id ){
-    unixFile *pFile = (unixFile*)id;
-    afpUnlock(id, NO_LOCK);
-    unixEnterMutex();
-    if( pFile->pInode && pFile->pInode->nLock ){
-      /* If there are outstanding locks, do not actually close the file just
-      ** yet because that would clear those locks.  Instead, add the file
-      ** descriptor to pInode->aPending.  It will be automatically closed when
-      ** the last lock is cleared.
-      */
-      setPendingFd(pFile);
-    }
-    releaseInodeInfo(pFile);
-    sqlite3_free(pFile->lockingContext);
-    rc = closeUnixFile(id);
-    unixLeaveMutex();
+  unixFile *pFile = (unixFile*)id;
+  assert( id!=0 );
+  afpUnlock(id, NO_LOCK);
+  unixEnterMutex();
+  if( pFile->pInode && pFile->pInode->nLock ){
+    /* If there are outstanding locks, do not actually close the file just
+    ** yet because that would clear those locks.  Instead, add the file
+    ** descriptor to pInode->aPending.  It will be automatically closed when
+    ** the last lock is cleared.
+    */
+    setPendingFd(pFile);
   }
+  releaseInodeInfo(pFile);
+  sqlite3_free(pFile->lockingContext);
+  rc = closeUnixFile(id);
+  unixLeaveMutex();
   return rc;
 }
 
@@ -27540,7 +32431,7 @@ static int nfsUnlock(sqlite3_file *id, int eFileLock){
 ** NB:  If you define USE_PREAD or USE_PREAD64, then it might also
 ** be necessary to define _XOPEN_SOURCE to be 500.  This varies from
 ** one system to another.  Since SQLite does not define USE_PREAD
-** any any form by default, we will not attempt to define _XOPEN_SOURCE.
+** in any form by default, we will not attempt to define _XOPEN_SOURCE.
 ** See tickets #2741 and #2681.
 **
 ** To avoid stomping the errno value on a failed read the lastErrno value
@@ -27548,35 +32439,46 @@ static int nfsUnlock(sqlite3_file *id, int eFileLock){
 */
 static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
   int got;
+  int prior = 0;
 #if (!defined(USE_PREAD) && !defined(USE_PREAD64))
   i64 newOffset;
 #endif
   TIMER_START;
+  assert( cnt==(cnt&0x1ffff) );
+  assert( id->h>2 );
+  do{
 #if defined(USE_PREAD)
-  do{ got = osPread(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
-  SimulateIOError( got = -1 );
+    got = osPread(id->h, pBuf, cnt, offset);
+    SimulateIOError( got = -1 );
 #elif defined(USE_PREAD64)
-  do{ got = osPread64(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR);
-  SimulateIOError( got = -1 );
+    got = osPread64(id->h, pBuf, cnt, offset);
+    SimulateIOError( got = -1 );
 #else
-  newOffset = lseek(id->h, offset, SEEK_SET);
-  SimulateIOError( newOffset-- );
-  if( newOffset!=offset ){
-    if( newOffset == -1 ){
-      ((unixFile*)id)->lastErrno = errno;
-    }else{
-      ((unixFile*)id)->lastErrno = 0;			
+    newOffset = lseek(id->h, offset, SEEK_SET);
+    SimulateIOError( newOffset = -1 );
+    if( newOffset<0 ){
+      storeLastErrno((unixFile*)id, errno);
+      return -1;
     }
-    return -1;
-  }
-  do{ got = osRead(id->h, pBuf, cnt); }while( got<0 && errno==EINTR );
+    got = osRead(id->h, pBuf, cnt);
 #endif
+    if( got==cnt ) break;
+    if( got<0 ){
+      if( errno==EINTR ){ got = 1; continue; }
+      prior = 0;
+      storeLastErrno((unixFile*)id,  errno);
+      break;
+    }else if( got>0 ){
+      cnt -= got;
+      offset += got;
+      prior += got;
+      pBuf = (void*)(got + (char*)pBuf);
+    }
+  }while( got>0 );
   TIMER_END;
-  if( got<0 ){
-    ((unixFile*)id)->lastErrno = errno;
-  }
-  OSTRACE(("READ    %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
-  return got;
+  OSTRACE(("READ    %-3d %5d %7lld %llu\n",
+            id->h, got+prior, offset-prior, TIMER_ELAPSED));
+  return got+prior;
 }
 
 /*
@@ -27593,6 +32495,8 @@ static int unixRead(
   unixFile *pFile = (unixFile *)id;
   int got;
   assert( id );
+  assert( offset>=0 );
+  assert( amt>0 );
 
   /* If this is a database file (not a journal, master-journal or temp
   ** file), the bytes in the locking range should never be read or written. */
@@ -27603,6 +32507,23 @@ static int unixRead(
   );
 #endif
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this read request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
+      return SQLITE_OK;
+    }else{
+      int nCopy = pFile->mmapSize - offset;
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
+
   got = seekAndRead(pFile, offset, pBuf, amt);
   if( got==amt ){
     return SQLITE_OK;
@@ -27610,7 +32531,7 @@ static int unixRead(
     /* lastErrno set by seekAndRead */
     return SQLITE_IOERR_READ;
   }else{
-    pFile->lastErrno = 0; /* not a system error */
+    storeLastErrno(pFile, 0);   /* not a system error */
     /* Unread parts of the buffer must be zero-filled */
     memset(&((char*)pBuf)[got], 0, amt-got);
     return SQLITE_IOERR_SHORT_READ;
@@ -27618,44 +32539,60 @@ static int unixRead(
 }
 
 /*
-** Seek to the offset in id->offset then read cnt bytes into pBuf.
-** Return the number of bytes actually read.  Update the offset.
-**
-** To avoid stomping the errno value on a failed write the lastErrno value
-** is set before returning.
+** Attempt to seek the file-descriptor passed as the first argument to
+** absolute offset iOff, then attempt to write nBuf bytes of data from
+** pBuf to it. If an error occurs, return -1 and set *piErrno. Otherwise, 
+** return the actual number of bytes written (which may be less than
+** nBuf).
 */
-static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
-  int got;
-#if (!defined(USE_PREAD) && !defined(USE_PREAD64))
-  i64 newOffset;
-#endif
+static int seekAndWriteFd(
+  int fd,                         /* File descriptor to write to */
+  i64 iOff,                       /* File offset to begin writing at */
+  const void *pBuf,               /* Copy data from this buffer to the file */
+  int nBuf,                       /* Size of buffer pBuf in bytes */
+  int *piErrno                    /* OUT: Error number if error occurs */
+){
+  int rc = 0;                     /* Value returned by system call */
+
+  assert( nBuf==(nBuf&0x1ffff) );
+  assert( fd>2 );
+  assert( piErrno!=0 );
+  nBuf &= 0x1ffff;
   TIMER_START;
+
 #if defined(USE_PREAD)
-  do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );
+  do{ rc = (int)osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
 #elif defined(USE_PREAD64)
-  do{ got = osPwrite64(id->h, pBuf, cnt, offset);}while( got<0 && errno==EINTR);
+  do{ rc = (int)osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
 #else
   do{
-    newOffset = lseek(id->h, offset, SEEK_SET);
-    SimulateIOError( newOffset-- );
-    if( newOffset!=offset ){
-      if( newOffset == -1 ){
-        ((unixFile*)id)->lastErrno = errno;
-      }else{
-        ((unixFile*)id)->lastErrno = 0;			
-      }
-      return -1;
+    i64 iSeek = lseek(fd, iOff, SEEK_SET);
+    SimulateIOError( iSeek = -1 );
+    if( iSeek<0 ){
+      rc = -1;
+      break;
     }
-    got = osWrite(id->h, pBuf, cnt);
-  }while( got<0 && errno==EINTR );
+    rc = osWrite(fd, pBuf, nBuf);
+  }while( rc<0 && errno==EINTR );
 #endif
+
   TIMER_END;
-  if( got<0 ){
-    ((unixFile*)id)->lastErrno = errno;
-  }
+  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));
 
-  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", id->h, got, offset, TIMER_ELAPSED));
-  return got;
+  if( rc<0 ) *piErrno = errno;
+  return rc;
+}
+
+
+/*
+** Seek to the offset in id->offset then read cnt bytes into pBuf.
+** Return the number of bytes actually read.  Update the offset.
+**
+** To avoid stomping the errno value on a failed write the lastErrno value
+** is set before returning.
+*/
+static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
+  return seekAndWriteFd(id->h, offset, pBuf, cnt, &id->lastErrno);
 }
 
 
@@ -27683,7 +32620,7 @@ static int unixWrite(
   );
 #endif
 
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
   /* If we are doing a normal write to a database file (as opposed to
   ** doing a hot-journal rollback or a write to some file other than a
   ** normal database file) then record the fact that the database
@@ -27705,7 +32642,24 @@ static int unixWrite(
   }
 #endif
 
-  while( amt>0 && (wrote = seekAndWrite(pFile, offset, pBuf, amt))>0 ){
+#if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this write request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
+      return SQLITE_OK;
+    }else{
+      int nCopy = pFile->mmapSize - offset;
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
+ 
+  while( (wrote = seekAndWrite(pFile, offset, pBuf, amt))<amt && wrote>0 ){
     amt -= wrote;
     offset += wrote;
     pBuf = &((char*)pBuf)[wrote];
@@ -27713,12 +32667,12 @@ static int unixWrite(
   SimulateIOError(( wrote=(-1), amt=1 ));
   SimulateDiskfullError(( wrote=0, amt=1 ));
 
-  if( amt>0 ){
+  if( amt>wrote ){
     if( wrote<0 && pFile->lastErrno!=ENOSPC ){
       /* lastErrno set by seekAndWrite */
       return SQLITE_IOERR_WRITE;
     }else{
-      pFile->lastErrno = 0; /* not a system error */
+      storeLastErrno(pFile, 0); /* not a system error */
       return SQLITE_FULL;
     }
   }
@@ -27739,9 +32693,9 @@ SQLITE_API int sqlite3_fullsync_count = 0;
 ** We do not trust systems to provide a working fdatasync().  Some do.
 ** Others do no.  To be safe, we will stick with the (slightly slower)
 ** fsync(). If you know that your system does support fdatasync() correctly,
-** then simply compile with -Dfdatasync=fdatasync
+** then simply compile with -Dfdatasync=fdatasync or -DHAVE_FDATASYNC
 */
-#if !defined(fdatasync)
+#if !defined(fdatasync) && !HAVE_FDATASYNC
 # define fdatasync fsync
 #endif
 
@@ -27809,10 +32763,15 @@ static int full_fsync(int fd, int fullSync, int dataOnly){
 #endif
 
   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
-  ** no-op
+  ** no-op.  But go ahead and call fstat() to validate the file
+  ** descriptor as we need a method to provoke a failure during
+  ** coverate testing.
   */
 #ifdef SQLITE_NO_SYNC
-  rc = SQLITE_OK;
+  {
+    struct stat buf;
+    rc = osFstat(fd, &buf);
+  }
 #elif HAVE_FULLFSYNC
   if( fullSync ){
     rc = osFcntl(fd, F_FULLFSYNC, 0);
@@ -27878,19 +32837,20 @@ static int openDirectory(const char *zFilename, int *pFd){
   char zDirname[MAX_PATHNAME+1];
 
   sqlite3_snprintf(MAX_PATHNAME, zDirname, "%s", zFilename);
-  for(ii=(int)strlen(zDirname); ii>1 && zDirname[ii]!='/'; ii--);
+  for(ii=(int)strlen(zDirname); ii>0 && zDirname[ii]!='/'; ii--);
   if( ii>0 ){
     zDirname[ii] = '\0';
-    fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
-    if( fd>=0 ){
-#ifdef FD_CLOEXEC
-      osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
-#endif
-      OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
-    }
+  }else{
+    if( zDirname[0]!='/' ) zDirname[0] = '.';
+    zDirname[1] = 0;
+  }
+  fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
+  if( fd>=0 ){
+    OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
   }
   *pFd = fd;
-  return (fd>=0?SQLITE_OK:unixLogError(SQLITE_CANTOPEN_BKPT, "open", zDirname));
+  if( fd>=0 ) return SQLITE_OK;
+  return unixLogError(SQLITE_CANTOPEN_BKPT, "openDirectory", zDirname);
 }
 
 /*
@@ -27930,12 +32890,12 @@ static int unixSync(sqlite3_file *id, int flags){
   rc = full_fsync(pFile->h, isFullsync, isDataOnly);
   SimulateIOError( rc=1 );
   if( rc ){
-    pFile->lastErrno = errno;
+    storeLastErrno(pFile, errno);
     return unixLogError(SQLITE_IOERR_FSYNC, "full_fsync", pFile->zPath);
   }
 
   /* Also fsync the directory containing the file if the DIRSYNC flag
-  ** is set.  This is a one-time occurrance.  Many systems (examples: AIX)
+  ** is set.  This is a one-time occurrence.  Many systems (examples: AIX)
   ** are unable to fsync a directory, so ignore errors on the fsync.
   */
   if( pFile->ctrlFlags & UNIXFILE_DIRSYNC ){
@@ -27943,10 +32903,11 @@ static int unixSync(sqlite3_file *id, int flags){
     OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
             HAVE_FULLFSYNC, isFullsync));
     rc = osOpenDirectory(pFile->zPath, &dirfd);
-    if( rc==SQLITE_OK && dirfd>=0 ){
+    if( rc==SQLITE_OK ){
       full_fsync(dirfd, 0, 0);
       robust_close(pFile, dirfd, __LINE__);
-    }else if( rc==SQLITE_CANTOPEN ){
+    }else{
+      assert( rc==SQLITE_CANTOPEN );
       rc = SQLITE_OK;
     }
     pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
@@ -27968,16 +32929,16 @@ static int unixTruncate(sqlite3_file *id, i64 nByte){
   ** actual file size after the operation may be larger than the requested
   ** size).
   */
-  if( pFile->szChunk ){
+  if( pFile->szChunk>0 ){
     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
   }
 
-  rc = robust_ftruncate(pFile->h, (off_t)nByte);
+  rc = robust_ftruncate(pFile->h, nByte);
   if( rc ){
-    pFile->lastErrno = errno;
+    storeLastErrno(pFile, errno);
     return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
   }else{
-#ifndef NDEBUG
+#ifdef SQLITE_DEBUG
     /* If we are doing a normal write to a database file (as opposed to
     ** doing a hot-journal rollback or a write to some file other than a
     ** normal database file) and we truncate the file to zero length,
@@ -27990,6 +32951,16 @@ static int unixTruncate(sqlite3_file *id, i64 nByte){
     }
 #endif
 
+#if SQLITE_MAX_MMAP_SIZE>0
+    /* If the file was just truncated to a size smaller than the currently
+    ** mapped region, reduce the effective mapping size as well. SQLite will
+    ** use read() and write() to access data beyond this point from now on.  
+    */
+    if( nByte<pFile->mmapSize ){
+      pFile->mmapSize = nByte;
+    }
+#endif
+
     return SQLITE_OK;
   }
 }
@@ -28004,7 +32975,7 @@ static int unixFileSize(sqlite3_file *id, i64 *pSize){
   rc = osFstat(((unixFile*)id)->h, &buf);
   SimulateIOError( rc=1 );
   if( rc!=0 ){
-    ((unixFile*)id)->lastErrno = errno;
+    storeLastErrno((unixFile*)id, errno);
     return SQLITE_IOERR_FSTAT;
   }
   *pSize = buf.st_size;
@@ -28040,7 +33011,9 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
     i64 nSize;                    /* Required file size */
     struct stat buf;              /* Used to hold return values of fstat() */
    
-    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;
+    if( osFstat(pFile->h, &buf) ){
+      return SQLITE_IOERR_FSTAT;
+    }
 
     nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;
     if( nSize>(i64)buf.st_size ){
@@ -28055,33 +33028,67 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
       }while( err==EINTR );
       if( err ) return SQLITE_IOERR_WRITE;
 #else
-      /* If the OS does not have posix_fallocate(), fake it. First use
-      ** ftruncate() to set the file size, then write a single byte to
-      ** the last byte in each block within the extended region. This
-      ** is the same technique used by glibc to implement posix_fallocate()
-      ** on systems that do not have a real fallocate() system call.
+      /* If the OS does not have posix_fallocate(), fake it. Write a 
+      ** single byte to the last byte in each block that falls entirely
+      ** within the extended region. Then, if required, a single byte
+      ** at offset (nSize-1), to set the size of the file correctly.
+      ** This is a similar technique to that used by glibc on systems
+      ** that do not have a real fallocate() call.
       */
       int nBlk = buf.st_blksize;  /* File-system block size */
+      int nWrite = 0;             /* Number of bytes written by seekAndWrite */
       i64 iWrite;                 /* Next offset to write to */
 
-      if( robust_ftruncate(pFile->h, nSize) ){
-        pFile->lastErrno = errno;
-        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
-      }
-      iWrite = ((buf.st_size + 2*nBlk - 1)/nBlk)*nBlk-1;
-      while( iWrite<nSize ){
-        int nWrite = seekAndWrite(pFile, iWrite, "", 1);
+      iWrite = (buf.st_size/nBlk)*nBlk + nBlk - 1;
+      assert( iWrite>=buf.st_size );
+      assert( ((iWrite+1)%nBlk)==0 );
+      for(/*no-op*/; iWrite<nSize+nBlk-1; iWrite+=nBlk ){
+        if( iWrite>=nSize ) iWrite = nSize - 1;
+        nWrite = seekAndWrite(pFile, iWrite, "", 1);
         if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
-        iWrite += nBlk;
       }
 #endif
     }
   }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){
+    int rc;
+    if( pFile->szChunk<=0 ){
+      if( robust_ftruncate(pFile->h, nByte) ){
+        storeLastErrno(pFile, errno);
+        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
+      }
+    }
+
+    rc = unixMapfile(pFile, nByte);
+    return rc;
+  }
+#endif
+
   return SQLITE_OK;
 }
 
 /*
+** If *pArg is initially negative then this is a query.  Set *pArg to
+** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
+**
+** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
+*/
+static void unixModeBit(unixFile *pFile, unsigned char mask, int *pArg){
+  if( *pArg<0 ){
+    *pArg = (pFile->ctrlFlags & mask)!=0;
+  }else if( (*pArg)==0 ){
+    pFile->ctrlFlags &= ~mask;
+  }else{
+    pFile->ctrlFlags |= mask;
+  }
+}
+
+/* Forward declaration */
+static int unixGetTempname(int nBuf, char *zBuf);
+
+/*
 ** Information and control of an open file handle.
 */
 static int unixFileControl(sqlite3_file *id, int op, void *pArg){
@@ -28091,7 +33098,7 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       *(int*)pArg = pFile->eFileLock;
       return SQLITE_OK;
     }
-    case SQLITE_LAST_ERRNO: {
+    case SQLITE_FCNTL_LAST_ERRNO: {
       *(int*)pArg = pFile->lastErrno;
       return SQLITE_OK;
     }
@@ -28107,17 +33114,48 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       return rc;
     }
     case SQLITE_FCNTL_PERSIST_WAL: {
-      int bPersist = *(int*)pArg;
-      if( bPersist<0 ){
-        *(int*)pArg = (pFile->ctrlFlags & UNIXFILE_PERSIST_WAL)!=0;
-      }else if( bPersist==0 ){
-        pFile->ctrlFlags &= ~UNIXFILE_PERSIST_WAL;
-      }else{
-        pFile->ctrlFlags |= UNIXFILE_PERSIST_WAL;
+      unixModeBit(pFile, UNIXFILE_PERSIST_WAL, (int*)pArg);
+      return SQLITE_OK;
+    }
+    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
+      unixModeBit(pFile, UNIXFILE_PSOW, (int*)pArg);
+      return SQLITE_OK;
+    }
+    case SQLITE_FCNTL_VFSNAME: {
+      *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
+      return SQLITE_OK;
+    }
+    case SQLITE_FCNTL_TEMPFILENAME: {
+      char *zTFile = sqlite3_malloc64( pFile->pVfs->mxPathname );
+      if( zTFile ){
+        unixGetTempname(pFile->pVfs->mxPathname, zTFile);
+        *(char**)pArg = zTFile;
       }
       return SQLITE_OK;
     }
-#ifndef NDEBUG
+    case SQLITE_FCNTL_HAS_MOVED: {
+      *(int*)pArg = fileHasMoved(pFile);
+      return SQLITE_OK;
+    }
+#if SQLITE_MAX_MMAP_SIZE>0
+    case SQLITE_FCNTL_MMAP_SIZE: {
+      i64 newLimit = *(i64*)pArg;
+      int rc = SQLITE_OK;
+      if( newLimit>sqlite3GlobalConfig.mxMmap ){
+        newLimit = sqlite3GlobalConfig.mxMmap;
+      }
+      *(i64*)pArg = pFile->mmapSizeMax;
+      if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
+        pFile->mmapSizeMax = newLimit;
+        if( pFile->mmapSize>0 ){
+          unixUnmapfile(pFile);
+          rc = unixMapfile(pFile, -1);
+        }
+      }
+      return rc;
+    }
+#endif
+#ifdef SQLITE_DEBUG
     /* The pager calls this method to signal that it has done
     ** a rollback and that the database is therefore unchanged and
     ** it hence it is OK for the transaction change counter to be
@@ -28129,14 +33167,11 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
     }
 #endif
 #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
-    case SQLITE_SET_LOCKPROXYFILE:
-    case SQLITE_GET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_SET_LOCKPROXYFILE:
+    case SQLITE_FCNTL_GET_LOCKPROXYFILE: {
       return proxyFileControl(id,op,pArg);
     }
 #endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
-    case SQLITE_FCNTL_SYNC_OMITTED: {
-      return SQLITE_OK;  /* A no-op */
-    }
   }
   return SQLITE_NOTFOUND;
 }
@@ -28151,21 +33186,140 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
 ** a database and its journal file) that the sector size will be the
 ** same for both.
 */
+#ifndef __QNXNTO__ 
 static int unixSectorSize(sqlite3_file *NotUsed){
   UNUSED_PARAMETER(NotUsed);
   return SQLITE_DEFAULT_SECTOR_SIZE;
 }
+#endif
 
 /*
-** Return the device characteristics for the file. This is always 0 for unix.
+** The following version of unixSectorSize() is optimized for QNX.
 */
-static int unixDeviceCharacteristics(sqlite3_file *NotUsed){
-  UNUSED_PARAMETER(NotUsed);
-  return 0;
+#ifdef __QNXNTO__
+#include <sys/dcmd_blk.h>
+#include <sys/statvfs.h>
+static int unixSectorSize(sqlite3_file *id){
+  unixFile *pFile = (unixFile*)id;
+  if( pFile->sectorSize == 0 ){
+    struct statvfs fsInfo;
+       
+    /* Set defaults for non-supported filesystems */
+    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
+    pFile->deviceCharacteristics = 0;
+    if( fstatvfs(pFile->h, &fsInfo) == -1 ) {
+      return pFile->sectorSize;
+    }
+
+    if( !strcmp(fsInfo.f_basetype, "tmp") ) {
+      pFile->sectorSize = fsInfo.f_bsize;
+      pFile->deviceCharacteristics =
+        SQLITE_IOCAP_ATOMIC4K |       /* All ram filesystem writes are atomic */
+        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
+                                      ** the write succeeds */
+        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
+                                      ** so it is ordered */
+        0;
+    }else if( strstr(fsInfo.f_basetype, "etfs") ){
+      pFile->sectorSize = fsInfo.f_bsize;
+      pFile->deviceCharacteristics =
+        /* etfs cluster size writes are atomic */
+        (pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) |
+        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
+                                      ** the write succeeds */
+        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
+                                      ** so it is ordered */
+        0;
+    }else if( !strcmp(fsInfo.f_basetype, "qnx6") ){
+      pFile->sectorSize = fsInfo.f_bsize;
+      pFile->deviceCharacteristics =
+        SQLITE_IOCAP_ATOMIC |         /* All filesystem writes are atomic */
+        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
+                                      ** the write succeeds */
+        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
+                                      ** so it is ordered */
+        0;
+    }else if( !strcmp(fsInfo.f_basetype, "qnx4") ){
+      pFile->sectorSize = fsInfo.f_bsize;
+      pFile->deviceCharacteristics =
+        /* full bitset of atomics from max sector size and smaller */
+        ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |
+        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
+                                      ** so it is ordered */
+        0;
+    }else if( strstr(fsInfo.f_basetype, "dos") ){
+      pFile->sectorSize = fsInfo.f_bsize;
+      pFile->deviceCharacteristics =
+        /* full bitset of atomics from max sector size and smaller */
+        ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |
+        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
+                                      ** so it is ordered */
+        0;
+    }else{
+      pFile->deviceCharacteristics =
+        SQLITE_IOCAP_ATOMIC512 |      /* blocks are atomic */
+        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
+                                      ** the write succeeds */
+        0;
+    }
+  }
+  /* Last chance verification.  If the sector size isn't a multiple of 512
+  ** then it isn't valid.*/
+  if( pFile->sectorSize % 512 != 0 ){
+    pFile->deviceCharacteristics = 0;
+    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
+  }
+  return pFile->sectorSize;
 }
+#endif /* __QNXNTO__ */
 
-#ifndef SQLITE_OMIT_WAL
+/*
+** Return the device characteristics for the file.
+**
+** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.
+** However, that choice is controversial since technically the underlying
+** file system does not always provide powersafe overwrites.  (In other
+** words, after a power-loss event, parts of the file that were never
+** written might end up being altered.)  However, non-PSOW behavior is very,
+** very rare.  And asserting PSOW makes a large reduction in the amount
+** of required I/O for journaling, since a lot of padding is eliminated.
+**  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control
+** available to turn it off and URI query parameter available to turn it off.
+*/
+static int unixDeviceCharacteristics(sqlite3_file *id){
+  unixFile *p = (unixFile*)id;
+  int rc = 0;
+#ifdef __QNXNTO__
+  if( p->sectorSize==0 ) unixSectorSize(id);
+  rc = p->deviceCharacteristics;
+#endif
+  if( p->ctrlFlags & UNIXFILE_PSOW ){
+    rc |= SQLITE_IOCAP_POWERSAFE_OVERWRITE;
+  }
+  return rc;
+}
 
+#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+
+/*
+** Return the system page size.
+**
+** This function should not be called directly by other code in this file. 
+** Instead, it should be called via macro osGetpagesize().
+*/
+static int unixGetpagesize(void){
+#if OS_VXWORKS
+  return 1024;
+#elif defined(_BSD_SOURCE)
+  return getpagesize();
+#else
+  return (int)sysconf(_SC_PAGESIZE);
+#endif
+}
+
+#endif /* !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0 */
+
+#ifndef SQLITE_OMIT_WAL
 
 /*
 ** Object used to represent an shared memory buffer.  
@@ -28249,22 +33403,24 @@ struct unixShm {
 ** otherwise.
 */
 static int unixShmSystemLock(
-  unixShmNode *pShmNode, /* Apply locks to this open shared-memory segment */
+  unixFile *pFile,       /* Open connection to the WAL file */
   int lockType,          /* F_UNLCK, F_RDLCK, or F_WRLCK */
   int ofst,              /* First byte of the locking range */
   int n                  /* Number of bytes to lock */
 ){
-  struct flock f;       /* The posix advisory locking structure */
-  int rc = SQLITE_OK;   /* Result code form fcntl() */
+  unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */
+  struct flock f;        /* The posix advisory locking structure */
+  int rc = SQLITE_OK;    /* Result code form fcntl() */
 
   /* Access to the unixShmNode object is serialized by the caller */
+  pShmNode = pFile->pInode->pShmNode;
   assert( sqlite3_mutex_held(pShmNode->mutex) || pShmNode->nRef==0 );
 
   /* Shared locks never span more than one byte */
   assert( n==1 || lockType!=F_RDLCK );
 
   /* Locks are within range */
-  assert( n>=1 && n<SQLITE_SHM_NLOCK );
+  assert( n>=1 && n<=SQLITE_SHM_NLOCK );
 
   if( pShmNode->h>=0 ){
     /* Initialize the locking parameters */
@@ -28282,7 +33438,7 @@ static int unixShmSystemLock(
 #ifdef SQLITE_DEBUG
   { u16 mask;
   OSTRACE(("SHM-LOCK "));
-  mask = (1<<(ofst+n)) - (1<<ofst);
+  mask = ofst>31 ? 0xffff : (1<<(ofst+n)) - (1<<ofst);
   if( rc==SQLITE_OK ){
     if( lockType==F_UNLCK ){
       OSTRACE(("unlock %d ok", ofst));
@@ -28316,6 +33472,22 @@ static int unixShmSystemLock(
   return rc;        
 }
 
+/*
+** Return the minimum number of 32KB shm regions that should be mapped at
+** a time, assuming that each mapping must be an integer multiple of the
+** current system page-size.
+**
+** Usually, this is 1. The exception seems to be systems that are configured
+** to use 64KB pages - in this case each mapping must cover at least two
+** shm regions.
+*/
+static int unixShmRegionPerMap(void){
+  int shmsz = 32*1024;            /* SHM region size */
+  int pgsz = osGetpagesize();   /* System page size */
+  assert( ((pgsz-1)&pgsz)==0 );   /* Page size must be a power of 2 */
+  if( pgsz<shmsz ) return 1;
+  return pgsz/shmsz;
+}
 
 /*
 ** Purge the unixShmNodeList list of all entries with unixShmNode.nRef==0.
@@ -28326,13 +33498,14 @@ static int unixShmSystemLock(
 static void unixShmPurge(unixFile *pFd){
   unixShmNode *p = pFd->pInode->pShmNode;
   assert( unixMutexHeld() );
-  if( p && p->nRef==0 ){
+  if( p && ALWAYS(p->nRef==0) ){
+    int nShmPerMap = unixShmRegionPerMap();
     int i;
     assert( p->pInode==pFd->pInode );
     sqlite3_mutex_free(p->mutex);
-    for(i=0; i<p->nRegion; i++){
+    for(i=0; i<p->nRegion; i+=nShmPerMap){
       if( p->h>=0 ){
-        munmap(p->apRegion[i], p->szRegion);
+        osMunmap(p->apRegion[i], p->szRegion);
       }else{
         sqlite3_free(p->apRegion[i]);
       }
@@ -28391,8 +33564,8 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
   int nShmFilename;               /* Size of the SHM filename in bytes */
 
   /* Allocate space for the new unixShm object. */
-  p = sqlite3_malloc( sizeof(*p) );
-  if( p==0 ) return SQLITE_NOMEM;
+  p = sqlite3_malloc64( sizeof(*p) );
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
   memset(p, 0, sizeof(*p));
   assert( pDbFd->pShm==0 );
 
@@ -28404,73 +33577,79 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
   pShmNode = pInode->pShmNode;
   if( pShmNode==0 ){
     struct stat sStat;                 /* fstat() info for database file */
+#ifndef SQLITE_SHM_DIRECTORY
+    const char *zBasePath = pDbFd->zPath;
+#endif
 
     /* Call fstat() to figure out the permissions on the database file. If
     ** a new *-shm file is created, an attempt will be made to create it
-    ** with the same permissions. The actual permissions the file is created
-    ** with are subject to the current umask setting.
+    ** with the same permissions.
     */
-    if( osFstat(pDbFd->h, &sStat) && pInode->bProcessLock==0 ){
+    if( osFstat(pDbFd->h, &sStat) ){
       rc = SQLITE_IOERR_FSTAT;
       goto shm_open_err;
     }
 
 #ifdef SQLITE_SHM_DIRECTORY
-    nShmFilename = sizeof(SQLITE_SHM_DIRECTORY) + 30;
+    nShmFilename = sizeof(SQLITE_SHM_DIRECTORY) + 31;
 #else
-    nShmFilename = 5 + (int)strlen(pDbFd->zPath);
+    nShmFilename = 6 + (int)strlen(zBasePath);
 #endif
-    pShmNode = sqlite3_malloc( sizeof(*pShmNode) + nShmFilename );
+    pShmNode = sqlite3_malloc64( sizeof(*pShmNode) + nShmFilename );
     if( pShmNode==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto shm_open_err;
     }
-    memset(pShmNode, 0, sizeof(*pShmNode));
+    memset(pShmNode, 0, sizeof(*pShmNode)+nShmFilename);
     zShmFilename = pShmNode->zFilename = (char*)&pShmNode[1];
 #ifdef SQLITE_SHM_DIRECTORY
     sqlite3_snprintf(nShmFilename, zShmFilename, 
                      SQLITE_SHM_DIRECTORY "/sqlite-shm-%x-%x",
                      (u32)sStat.st_ino, (u32)sStat.st_dev);
 #else
-    sqlite3_snprintf(nShmFilename, zShmFilename, "%s-shm", pDbFd->zPath);
+    sqlite3_snprintf(nShmFilename, zShmFilename, "%s-shm", zBasePath);
     sqlite3FileSuffix3(pDbFd->zPath, zShmFilename);
 #endif
     pShmNode->h = -1;
     pDbFd->pInode->pShmNode = pShmNode;
     pShmNode->pInode = pDbFd->pInode;
-    pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-    if( pShmNode->mutex==0 ){
-      rc = SQLITE_NOMEM;
-      goto shm_open_err;
+    if( sqlite3GlobalConfig.bCoreMutex ){
+      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+      if( pShmNode->mutex==0 ){
+        rc = SQLITE_NOMEM_BKPT;
+        goto shm_open_err;
+      }
     }
 
     if( pInode->bProcessLock==0 ){
-      const char *zRO;
       int openFlags = O_RDWR | O_CREAT;
-      zRO = sqlite3_uri_parameter(pDbFd->zPath, "readonly_shm");
-      if( zRO && sqlite3GetBoolean(zRO) ){
+      if( sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
         openFlags = O_RDONLY;
         pShmNode->isReadonly = 1;
       }
       pShmNode->h = robust_open(zShmFilename, openFlags, (sStat.st_mode&0777));
       if( pShmNode->h<0 ){
-        if( pShmNode->h<0 ){
-          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
-          goto shm_open_err;
-        }
+        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
+        goto shm_open_err;
       }
+
+      /* If this process is running as root, make sure that the SHM file
+      ** is owned by the same user that owns the original database.  Otherwise,
+      ** the original owner will not be able to connect.
+      */
+      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
   
       /* Check to see if another process is holding the dead-man switch.
       ** If not, truncate the file to zero length. 
       */
       rc = SQLITE_OK;
-      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
+      if( unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
         if( robust_ftruncate(pShmNode->h, 0) ){
           rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
         }
       }
       if( rc==SQLITE_OK ){
-        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
+        rc = unixShmSystemLock(pDbFd, F_RDLCK, UNIX_SHM_DMS, 1);
       }
       if( rc ) goto shm_open_err;
     }
@@ -28536,6 +33715,8 @@ static int unixShmMap(
   unixShm *p;
   unixShmNode *pShmNode;
   int rc = SQLITE_OK;
+  int nShmPerMap = unixShmRegionPerMap();
+  int nReqRegion;
 
   /* If the shared-memory file has not yet been opened, open it now. */
   if( pDbFd->pShm==0 ){
@@ -28551,9 +33732,12 @@ static int unixShmMap(
   assert( pShmNode->h>=0 || pDbFd->pInode->bProcessLock==1 );
   assert( pShmNode->h<0 || pDbFd->pInode->bProcessLock==0 );
 
-  if( pShmNode->nRegion<=iRegion ){
+  /* Minimum number of regions required to be mapped. */
+  nReqRegion = ((iRegion+nShmPerMap) / nShmPerMap) * nShmPerMap;
+
+  if( pShmNode->nRegion<nReqRegion ){
     char **apNew;                      /* New apRegion[] array */
-    int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
+    int nByte = nReqRegion*szRegion;   /* Minimum required file size */
     struct stat sStat;                 /* Used by fstat() */
 
     pShmNode->szRegion = szRegion;
@@ -28571,49 +33755,71 @@ static int unixShmMap(
       if( sStat.st_size<nByte ){
         /* The requested memory region does not exist. If bExtend is set to
         ** false, exit early. *pp will be set to NULL and SQLITE_OK returned.
-        **
-        ** Alternatively, if bExtend is true, use ftruncate() to allocate
-        ** the requested memory region.
         */
-        if( !bExtend ) goto shmpage_out;
-        if( robust_ftruncate(pShmNode->h, nByte) ){
-          rc = unixLogError(SQLITE_IOERR_SHMSIZE, "ftruncate",
-                            pShmNode->zFilename);
+        if( !bExtend ){
           goto shmpage_out;
         }
+
+        /* Alternatively, if bExtend is true, extend the file. Do this by
+        ** writing a single byte to the end of each (OS) page being
+        ** allocated or extended. Technically, we need only write to the
+        ** last page in order to extend the file. But writing to all new
+        ** pages forces the OS to allocate them immediately, which reduces
+        ** the chances of SIGBUS while accessing the mapped region later on.
+        */
+        else{
+          static const int pgsz = 4096;
+          int iPg;
+
+          /* Write to the last byte of each newly allocated or extended page */
+          assert( (nByte % pgsz)==0 );
+          for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
+            int x = 0;
+            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, &x)!=1 ){
+              const char *zFile = pShmNode->zFilename;
+              rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);
+              goto shmpage_out;
+            }
+          }
+        }
       }
     }
 
     /* Map the requested memory region into this processes address space. */
     apNew = (char **)sqlite3_realloc(
-        pShmNode->apRegion, (iRegion+1)*sizeof(char *)
+        pShmNode->apRegion, nReqRegion*sizeof(char *)
     );
     if( !apNew ){
-      rc = SQLITE_IOERR_NOMEM;
+      rc = SQLITE_IOERR_NOMEM_BKPT;
       goto shmpage_out;
     }
     pShmNode->apRegion = apNew;
-    while(pShmNode->nRegion<=iRegion){
+    while( pShmNode->nRegion<nReqRegion ){
+      int nMap = szRegion*nShmPerMap;
+      int i;
       void *pMem;
       if( pShmNode->h>=0 ){
-        pMem = mmap(0, szRegion,
+        pMem = osMmap(0, nMap,
             pShmNode->isReadonly ? PROT_READ : PROT_READ|PROT_WRITE, 
-            MAP_SHARED, pShmNode->h, pShmNode->nRegion*szRegion
+            MAP_SHARED, pShmNode->h, szRegion*(i64)pShmNode->nRegion
         );
         if( pMem==MAP_FAILED ){
           rc = unixLogError(SQLITE_IOERR_SHMMAP, "mmap", pShmNode->zFilename);
           goto shmpage_out;
         }
       }else{
-        pMem = sqlite3_malloc(szRegion);
+        pMem = sqlite3_malloc64(szRegion);
         if( pMem==0 ){
-          rc = SQLITE_NOMEM;
+          rc = SQLITE_NOMEM_BKPT;
           goto shmpage_out;
         }
         memset(pMem, 0, szRegion);
       }
-      pShmNode->apRegion[pShmNode->nRegion] = pMem;
-      pShmNode->nRegion++;
+
+      for(i=0; i<nShmPerMap; i++){
+        pShmNode->apRegion[pShmNode->nRegion+i] = &((char*)pMem)[szRegion*i];
+      }
+      pShmNode->nRegion += nShmPerMap;
     }
   }
 
@@ -28676,7 +33882,7 @@ static int unixShmLock(
 
     /* Unlock the system-level locks */
     if( (mask & allMask)==0 ){
-      rc = unixShmSystemLock(pShmNode, F_UNLCK, ofst+UNIX_SHM_BASE, n);
+      rc = unixShmSystemLock(pDbFd, F_UNLCK, ofst+UNIX_SHM_BASE, n);
     }else{
       rc = SQLITE_OK;
     }
@@ -28704,7 +33910,7 @@ static int unixShmLock(
     /* Get shared locks at the system level, if necessary */
     if( rc==SQLITE_OK ){
       if( (allShared & mask)==0 ){
-        rc = unixShmSystemLock(pShmNode, F_RDLCK, ofst+UNIX_SHM_BASE, n);
+        rc = unixShmSystemLock(pDbFd, F_RDLCK, ofst+UNIX_SHM_BASE, n);
       }else{
         rc = SQLITE_OK;
       }
@@ -28729,7 +33935,7 @@ static int unixShmLock(
     ** also mark the local connection as being locked.
     */
     if( rc==SQLITE_OK ){
-      rc = unixShmSystemLock(pShmNode, F_WRLCK, ofst+UNIX_SHM_BASE, n);
+      rc = unixShmSystemLock(pDbFd, F_WRLCK, ofst+UNIX_SHM_BASE, n);
       if( rc==SQLITE_OK ){
         assert( (p->sharedMask & mask)==0 );
         p->exclMask |= mask;
@@ -28738,7 +33944,7 @@ static int unixShmLock(
   }
   sqlite3_mutex_leave(pShmNode->mutex);
   OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x\n",
-           p->id, getpid(), p->sharedMask, p->exclMask));
+           p->id, osGetpid(0), p->sharedMask, p->exclMask));
   return rc;
 }
 
@@ -28752,7 +33958,8 @@ static void unixShmBarrier(
   sqlite3_file *fd                /* Database file holding the shared memory */
 ){
   UNUSED_PARAMETER(fd);
-  unixEnterMutex();
+  sqlite3MemoryBarrier();         /* compiler-defined memory barrier */
+  unixEnterMutex();               /* Also mutex, for redundancy */
   unixLeaveMutex();
 }
 
@@ -28797,7 +34004,9 @@ static int unixShmUnmap(
   assert( pShmNode->nRef>0 );
   pShmNode->nRef--;
   if( pShmNode->nRef==0 ){
-    if( deleteFlag && pShmNode->h>=0 ) osUnlink(pShmNode->zFilename);
+    if( deleteFlag && pShmNode->h>=0 ){
+      osUnlink(pShmNode->zFilename);
+    }
     unixShmPurge(pDbFd);
   }
   unixLeaveMutex();
@@ -28813,6 +34022,223 @@ static int unixShmUnmap(
 # define unixShmUnmap   0
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/*
+** If it is currently memory mapped, unmap file pFd.
+*/
+static void unixUnmapfile(unixFile *pFd){
+  assert( pFd->nFetchOut==0 );
+  if( pFd->pMapRegion ){
+    osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
+    pFd->pMapRegion = 0;
+    pFd->mmapSize = 0;
+    pFd->mmapSizeActual = 0;
+  }
+}
+
+/*
+** Attempt to set the size of the memory mapping maintained by file 
+** descriptor pFd to nNew bytes. Any existing mapping is discarded.
+**
+** If successful, this function sets the following variables:
+**
+**       unixFile.pMapRegion
+**       unixFile.mmapSize
+**       unixFile.mmapSizeActual
+**
+** If unsuccessful, an error message is logged via sqlite3_log() and
+** the three variables above are zeroed. In this case SQLite should
+** continue accessing the database using the xRead() and xWrite()
+** methods.
+*/
+static void unixRemapfile(
+  unixFile *pFd,                  /* File descriptor object */
+  i64 nNew                        /* Required mapping size */
+){
+  const char *zErr = "mmap";
+  int h = pFd->h;                      /* File descriptor open on db file */
+  u8 *pOrig = (u8 *)pFd->pMapRegion;   /* Pointer to current file mapping */
+  i64 nOrig = pFd->mmapSizeActual;     /* Size of pOrig region in bytes */
+  u8 *pNew = 0;                        /* Location of new mapping */
+  int flags = PROT_READ;               /* Flags to pass to mmap() */
+
+  assert( pFd->nFetchOut==0 );
+  assert( nNew>pFd->mmapSize );
+  assert( nNew<=pFd->mmapSizeMax );
+  assert( nNew>0 );
+  assert( pFd->mmapSizeActual>=pFd->mmapSize );
+  assert( MAP_FAILED!=0 );
+
+#ifdef SQLITE_MMAP_READWRITE
+  if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;
+#endif
+
+  if( pOrig ){
+#if HAVE_MREMAP
+    i64 nReuse = pFd->mmapSize;
+#else
+    const int szSyspage = osGetpagesize();
+    i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));
+#endif
+    u8 *pReq = &pOrig[nReuse];
+
+    /* Unmap any pages of the existing mapping that cannot be reused. */
+    if( nReuse!=nOrig ){
+      osMunmap(pReq, nOrig-nReuse);
+    }
+
+#if HAVE_MREMAP
+    pNew = osMremap(pOrig, nReuse, nNew, MREMAP_MAYMOVE);
+    zErr = "mremap";
+#else
+    pNew = osMmap(pReq, nNew-nReuse, flags, MAP_SHARED, h, nReuse);
+    if( pNew!=MAP_FAILED ){
+      if( pNew!=pReq ){
+        osMunmap(pNew, nNew - nReuse);
+        pNew = 0;
+      }else{
+        pNew = pOrig;
+      }
+    }
+#endif
+
+    /* The attempt to extend the existing mapping failed. Free it. */
+    if( pNew==MAP_FAILED || pNew==0 ){
+      osMunmap(pOrig, nReuse);
+    }
+  }
+
+  /* If pNew is still NULL, try to create an entirely new mapping. */
+  if( pNew==0 ){
+    pNew = osMmap(0, nNew, flags, MAP_SHARED, h, 0);
+  }
+
+  if( pNew==MAP_FAILED ){
+    pNew = 0;
+    nNew = 0;
+    unixLogError(SQLITE_OK, zErr, pFd->zPath);
+
+    /* If the mmap() above failed, assume that all subsequent mmap() calls
+    ** will probably fail too. Fall back to using xRead/xWrite exclusively
+    ** in this case.  */
+    pFd->mmapSizeMax = 0;
+  }
+  pFd->pMapRegion = (void *)pNew;
+  pFd->mmapSize = pFd->mmapSizeActual = nNew;
+}
+
+/*
+** Memory map or remap the file opened by file-descriptor pFd (if the file
+** is already mapped, the existing mapping is replaced by the new). Or, if 
+** there already exists a mapping for this file, and there are still 
+** outstanding xFetch() references to it, this function is a no-op.
+**
+** If parameter nByte is non-negative, then it is the requested size of 
+** the mapping to create. Otherwise, if nByte is less than zero, then the 
+** requested size is the size of the file on disk. The actual size of the
+** created mapping is either the requested size or the value configured 
+** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.
+**
+** SQLITE_OK is returned if no error occurs (even if the mapping is not
+** recreated as a result of outstanding references) or an SQLite error
+** code otherwise.
+*/
+static int unixMapfile(unixFile *pFd, i64 nMap){
+  assert( nMap>=0 || pFd->nFetchOut==0 );
+  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
+  if( pFd->nFetchOut>0 ) return SQLITE_OK;
+
+  if( nMap<0 ){
+    struct stat statbuf;          /* Low-level file information */
+    if( osFstat(pFd->h, &statbuf) ){
+      return SQLITE_IOERR_FSTAT;
+    }
+    nMap = statbuf.st_size;
+  }
+  if( nMap>pFd->mmapSizeMax ){
+    nMap = pFd->mmapSizeMax;
+  }
+
+  assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
+  if( nMap!=pFd->mmapSize ){
+    unixRemapfile(pFd, nMap);
+  }
+
+  return SQLITE_OK;
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+/*
+** If possible, return a pointer to a mapping of file fd starting at offset
+** iOff. The mapping must be valid for at least nAmt bytes.
+**
+** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
+** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
+** Finally, if an error does occur, return an SQLite error code. The final
+** value of *pp is undefined in this case.
+**
+** If this function does return a pointer, the caller must eventually 
+** release the reference by calling unixUnfetch().
+*/
+static int unixFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
+#if SQLITE_MAX_MMAP_SIZE>0
+  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
+#endif
+  *pp = 0;
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFd->mmapSizeMax>0 ){
+    if( pFd->pMapRegion==0 ){
+      int rc = unixMapfile(pFd, -1);
+      if( rc!=SQLITE_OK ) return rc;
+    }
+    if( pFd->mmapSize >= iOff+nAmt ){
+      *pp = &((u8 *)pFd->pMapRegion)[iOff];
+      pFd->nFetchOut++;
+    }
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** If the third argument is non-NULL, then this function releases a 
+** reference obtained by an earlier call to unixFetch(). The second
+** argument passed to this function must be the same as the corresponding
+** argument that was passed to the unixFetch() invocation. 
+**
+** Or, if the third argument is NULL, then this function is being called 
+** to inform the VFS layer that, according to POSIX, any existing mapping 
+** may now be invalid and should be unmapped.
+*/
+static int unixUnfetch(sqlite3_file *fd, i64 iOff, void *p){
+#if SQLITE_MAX_MMAP_SIZE>0
+  unixFile *pFd = (unixFile *)fd;   /* The underlying database file */
+  UNUSED_PARAMETER(iOff);
+
+  /* If p==0 (unmap the entire file) then there must be no outstanding 
+  ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
+  ** then there must be at least one outstanding.  */
+  assert( (p==0)==(pFd->nFetchOut==0) );
+
+  /* If p!=0, it must match the iOff value. */
+  assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
+
+  if( p ){
+    pFd->nFetchOut--;
+  }else{
+    unixUnmapfile(pFd);
+  }
+
+  assert( pFd->nFetchOut>=0 );
+#else
+  UNUSED_PARAMETER(fd);
+  UNUSED_PARAMETER(p);
+  UNUSED_PARAMETER(iOff);
+#endif
+  return SQLITE_OK;
+}
+
 /*
 ** Here ends the implementation of all sqlite3_file methods.
 **
@@ -28832,7 +34258,7 @@ static int unixShmUnmap(
 ** looks at the filesystem type and tries to guess the best locking
 ** strategy from that.
 **
-** For finder-funtion F, two objects are created:
+** For finder-function F, two objects are created:
 **
 **    (1) The real finder-function named "FImpt()".
 **
@@ -28853,7 +34279,7 @@ static int unixShmUnmap(
 **   *  An I/O method finder function called FINDER that returns a pointer
 **      to the METHOD object in the previous bullet.
 */
-#define IOMETHODS(FINDER, METHOD, VERSION, CLOSE, LOCK, UNLOCK, CKLOCK)      \
+#define IOMETHODS(FINDER,METHOD,VERSION,CLOSE,LOCK,UNLOCK,CKLOCK,SHMMAP)     \
 static const sqlite3_io_methods METHOD = {                                   \
    VERSION,                    /* iVersion */                                \
    CLOSE,                      /* xClose */                                  \
@@ -28868,10 +34294,12 @@ static const sqlite3_io_methods METHOD = {                                   \
    unixFileControl,            /* xFileControl */                            \
    unixSectorSize,             /* xSectorSize */                             \
    unixDeviceCharacteristics,  /* xDeviceCapabilities */                     \
-   unixShmMap,                 /* xShmMap */                                 \
+   SHMMAP,                     /* xShmMap */                                 \
    unixShmLock,                /* xShmLock */                                \
    unixShmBarrier,             /* xShmBarrier */                             \
-   unixShmUnmap                /* xShmUnmap */                               \
+   unixShmUnmap,               /* xShmUnmap */                               \
+   unixFetch,                  /* xFetch */                                  \
+   unixUnfetch,                /* xUnfetch */                                \
 };                                                                           \
 static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){   \
   UNUSED_PARAMETER(z); UNUSED_PARAMETER(p);                                  \
@@ -28888,20 +34316,22 @@ static const sqlite3_io_methods *(*const FINDER)(const char*,unixFile *p)    \
 IOMETHODS(
   posixIoFinder,            /* Finder function name */
   posixIoMethods,           /* sqlite3_io_methods object name */
-  2,                        /* shared memory is enabled */
+  3,                        /* shared memory and mmap are enabled */
   unixClose,                /* xClose method */
   unixLock,                 /* xLock method */
   unixUnlock,               /* xUnlock method */
-  unixCheckReservedLock     /* xCheckReservedLock method */
+  unixCheckReservedLock,    /* xCheckReservedLock method */
+  unixShmMap                /* xShmMap method */
 )
 IOMETHODS(
   nolockIoFinder,           /* Finder function name */
   nolockIoMethods,          /* sqlite3_io_methods object name */
-  1,                        /* shared memory is disabled */
+  3,                        /* shared memory is disabled */
   nolockClose,              /* xClose method */
   nolockLock,               /* xLock method */
   nolockUnlock,             /* xUnlock method */
-  nolockCheckReservedLock   /* xCheckReservedLock method */
+  nolockCheckReservedLock,  /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 IOMETHODS(
   dotlockIoFinder,          /* Finder function name */
@@ -28910,10 +34340,11 @@ IOMETHODS(
   dotlockClose,             /* xClose method */
   dotlockLock,              /* xLock method */
   dotlockUnlock,            /* xUnlock method */
-  dotlockCheckReservedLock  /* xCheckReservedLock method */
+  dotlockCheckReservedLock, /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 
-#if SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE
 IOMETHODS(
   flockIoFinder,            /* Finder function name */
   flockIoMethods,           /* sqlite3_io_methods object name */
@@ -28921,7 +34352,8 @@ IOMETHODS(
   flockClose,               /* xClose method */
   flockLock,                /* xLock method */
   flockUnlock,              /* xUnlock method */
-  flockCheckReservedLock    /* xCheckReservedLock method */
+  flockCheckReservedLock,   /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 #endif
 
@@ -28930,10 +34362,11 @@ IOMETHODS(
   semIoFinder,              /* Finder function name */
   semIoMethods,             /* sqlite3_io_methods object name */
   1,                        /* shared memory is disabled */
-  semClose,                 /* xClose method */
-  semLock,                  /* xLock method */
-  semUnlock,                /* xUnlock method */
-  semCheckReservedLock      /* xCheckReservedLock method */
+  semXClose,                /* xClose method */
+  semXLock,                 /* xLock method */
+  semXUnlock,               /* xUnlock method */
+  semXCheckReservedLock,    /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 #endif
 
@@ -28945,7 +34378,8 @@ IOMETHODS(
   afpClose,                 /* xClose method */
   afpLock,                  /* xLock method */
   afpUnlock,                /* xUnlock method */
-  afpCheckReservedLock      /* xCheckReservedLock method */
+  afpCheckReservedLock,     /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 #endif
 
@@ -28970,7 +34404,8 @@ IOMETHODS(
   proxyClose,               /* xClose method */
   proxyLock,                /* xLock method */
   proxyUnlock,              /* xUnlock method */
-  proxyCheckReservedLock    /* xCheckReservedLock method */
+  proxyCheckReservedLock,   /* xCheckReservedLock method */
+  0                         /* xShmMap method */
 )
 #endif
 
@@ -28983,7 +34418,8 @@ IOMETHODS(
   unixClose,                 /* xClose method */
   unixLock,                  /* xLock method */
   nfsUnlock,                 /* xUnlock method */
-  unixCheckReservedLock      /* xCheckReservedLock method */
+  unixCheckReservedLock,     /* xCheckReservedLock method */
+  0                          /* xShmMap method */
 )
 #endif
 
@@ -29053,15 +34489,13 @@ static const sqlite3_io_methods
 
 #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */
 
-#if OS_VXWORKS && SQLITE_ENABLE_LOCKING_STYLE
-/* 
-** This "finder" function attempts to determine the best locking strategy 
-** for the database file "filePath".  It then returns the sqlite3_io_methods
-** object that implements that strategy.
-**
-** This is for VXWorks only.
+#if OS_VXWORKS
+/*
+** This "finder" function for VxWorks checks to see if posix advisory
+** locking works.  If it does, then that is what is used.  If it does not
+** work, then fallback to named semaphore locking.
 */
-static const sqlite3_io_methods *autolockIoFinderImpl(
+static const sqlite3_io_methods *vxworksIoFinderImpl(
   const char *filePath,    /* name of the database file */
   unixFile *pNew           /* the open file object */
 ){
@@ -29087,12 +34521,12 @@ static const sqlite3_io_methods *autolockIoFinderImpl(
   }
 }
 static const sqlite3_io_methods 
-  *(*const autolockIoFinder)(const char*,unixFile*) = autolockIoFinderImpl;
+  *(*const vxworksIoFinder)(const char*,unixFile*) = vxworksIoFinderImpl;
 
-#endif /* OS_VXWORKS && SQLITE_ENABLE_LOCKING_STYLE */
+#endif /* OS_VXWORKS */
 
 /*
-** An abstract type for a pointer to a IO method finder function:
+** An abstract type for a pointer to an IO method finder function:
 */
 typedef const sqlite3_io_methods *(*finder_type)(const char*,unixFile*);
 
@@ -29110,12 +34544,9 @@ typedef const sqlite3_io_methods *(*finder_type)(const char*,unixFile*);
 static int fillInUnixFile(
   sqlite3_vfs *pVfs,      /* Pointer to vfs object */
   int h,                  /* Open file descriptor of file being opened */
-  int syncDir,            /* True to sync directory on first sync */
   sqlite3_file *pId,      /* Write to the unixFile structure here */
   const char *zFilename,  /* Name of the file being opened */
-  int noLock,             /* Omit locking if true */
-  int isDelete,           /* Delete on close if true */
-  int isReadOnly          /* True if the file is opened read-only */
+  int ctrlFlags           /* Zero or more UNIXFILE_* values */
 ){
   const sqlite3_io_methods *pLockingStyle;
   unixFile *pNew = (unixFile *)pId;
@@ -29123,11 +34554,6 @@ static int fillInUnixFile(
 
   assert( pNew->pInode==NULL );
 
-  /* Parameter isDelete is only used on vxworks. Express this explicitly 
-  ** here to prevent compiler warnings about unused parameters.
-  */
-  UNUSED_PARAMETER(isDelete);
-
   /* Usually the path zFilename should not be a relative pathname. The
   ** exception is when opening the proxy "conch" file in builds that
   ** include the special Apple locking styles.
@@ -29140,32 +34566,33 @@ static int fillInUnixFile(
 #endif
 
   /* No locking occurs in temporary files */
-  assert( zFilename!=0 || noLock );
+  assert( zFilename!=0 || (ctrlFlags & UNIXFILE_NOLOCK)!=0 );
 
   OSTRACE(("OPEN    %-3d %s\n", h, zFilename));
   pNew->h = h;
+  pNew->pVfs = pVfs;
   pNew->zPath = zFilename;
-  if( memcmp(pVfs->zName,"unix-excl",10)==0 ){
-    pNew->ctrlFlags = UNIXFILE_EXCL;
-  }else{
-    pNew->ctrlFlags = 0;
-  }
-  if( isReadOnly ){
-    pNew->ctrlFlags |= UNIXFILE_RDONLY;
+  pNew->ctrlFlags = (u8)ctrlFlags;
+#if SQLITE_MAX_MMAP_SIZE>0
+  pNew->mmapSizeMax = sqlite3GlobalConfig.szMmap;
+#endif
+  if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),
+                           "psow", SQLITE_POWERSAFE_OVERWRITE) ){
+    pNew->ctrlFlags |= UNIXFILE_PSOW;
   }
-  if( syncDir ){
-    pNew->ctrlFlags |= UNIXFILE_DIRSYNC;
+  if( strcmp(pVfs->zName,"unix-excl")==0 ){
+    pNew->ctrlFlags |= UNIXFILE_EXCL;
   }
 
 #if OS_VXWORKS
   pNew->pId = vxworksFindFileId(zFilename);
   if( pNew->pId==0 ){
-    noLock = 1;
-    rc = SQLITE_NOMEM;
+    ctrlFlags |= UNIXFILE_NOLOCK;
+    rc = SQLITE_NOMEM_BKPT;
   }
 #endif
 
-  if( noLock ){
+  if( ctrlFlags & UNIXFILE_NOLOCK ){
     pLockingStyle = &nolockIoMethods;
   }else{
     pLockingStyle = (**(finder_type*)pVfs->pAppData)(zFilename, pNew);
@@ -29185,7 +34612,7 @@ static int fillInUnixFile(
     unixEnterMutex();
     rc = findInodeInfo(pNew, &pNew->pInode);
     if( rc!=SQLITE_OK ){
-      /* If an error occured in findInodeInfo(), close the file descriptor
+      /* If an error occurred in findInodeInfo(), close the file descriptor
       ** immediately, before releasing the mutex. findInodeInfo() may fail
       ** in two scenarios:
       **
@@ -29215,9 +34642,9 @@ static int fillInUnixFile(
     ** the afpLockingContext.
     */
     afpLockingContext *pCtx;
-    pNew->lockingContext = pCtx = sqlite3_malloc( sizeof(*pCtx) );
+    pNew->lockingContext = pCtx = sqlite3_malloc64( sizeof(*pCtx) );
     if( pCtx==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       /* NB: zFilename exists and remains valid until the file is closed
       ** according to requirement F11141.  So we do not need to make a
@@ -29245,9 +34672,9 @@ static int fillInUnixFile(
     int nFilename;
     assert( zFilename!=0 );
     nFilename = (int)strlen(zFilename) + 6;
-    zLockFile = (char *)sqlite3_malloc(nFilename);
+    zLockFile = (char *)sqlite3_malloc64(nFilename);
     if( zLockFile==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       sqlite3_snprintf(nFilename, zLockFile, "%s" DOTLOCK_SUFFIX, zFilename);
     }
@@ -29270,7 +34697,7 @@ static int fillInUnixFile(
         if( zSemName[n]=='/' ) zSemName[n] = '_';
       pNew->pInode->pSem = sem_open(zSemName, O_CREAT, 0666, 1);
       if( pNew->pInode->pSem == SEM_FAILED ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
         pNew->pInode->aSemName[0] = '\0';
       }
     }
@@ -29278,21 +34705,21 @@ static int fillInUnixFile(
   }
 #endif
   
-  pNew->lastErrno = 0;
+  storeLastErrno(pNew, 0);
 #if OS_VXWORKS
   if( rc!=SQLITE_OK ){
     if( h>=0 ) robust_close(pNew, h, __LINE__);
     h = -1;
     osUnlink(zFilename);
-    isDelete = 0;
+    pNew->ctrlFlags |= UNIXFILE_DELETE;
   }
-  pNew->isDelete = isDelete;
 #endif
   if( rc!=SQLITE_OK ){
     if( h>=0 ) robust_close(pNew, h, __LINE__);
   }else{
     pNew->pMethod = pLockingStyle;
     OpenCounter(+1);
+    verifyDbFile(pNew);
   }
   return rc;
 }
@@ -29308,22 +34735,26 @@ static const char *unixTempFileDir(void){
      "/var/tmp",
      "/usr/tmp",
      "/tmp",
-     0        /* List terminator */
+     "."
   };
-  unsigned int i;
+  unsigned int i = 0;
   struct stat buf;
-  const char *zDir = 0;
+  const char *zDir = sqlite3_temp_directory;
 
-  azDirs[0] = sqlite3_temp_directory;
+  if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
   if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
-  for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
-    if( zDir==0 ) continue;
-    if( osStat(zDir, &buf) ) continue;
-    if( !S_ISDIR(buf.st_mode) ) continue;
-    if( osAccess(zDir, 07) ) continue;
-    break;
+  while(1){
+    if( zDir!=0
+     && osStat(zDir, &buf)==0
+     && S_ISDIR(buf.st_mode)
+     && osAccess(zDir, 03)==0
+    ){
+      return zDir;
+    }
+    if( i>=sizeof(azDirs)/sizeof(azDirs[0]) ) break;
+    zDir = azDirs[i++];
   }
-  return zDir;
+  return 0;
 }
 
 /*
@@ -29332,37 +34763,26 @@ static const char *unixTempFileDir(void){
 ** pVfs->mxPathname bytes.
 */
 static int unixGetTempname(int nBuf, char *zBuf){
-  static const unsigned char zChars[] =
-    "abcdefghijklmnopqrstuvwxyz"
-    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-    "0123456789";
-  unsigned int i, j;
   const char *zDir;
+  int iLimit = 0;
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
   ** function failing. 
   */
+  zBuf[0] = 0;
   SimulateIOError( return SQLITE_IOERR );
 
   zDir = unixTempFileDir();
-  if( zDir==0 ) zDir = ".";
-
-  /* Check that the output buffer is large enough for the temporary file 
-  ** name. If it is not, return SQLITE_ERROR.
-  */
-  if( (strlen(zDir) + strlen(SQLITE_TEMP_FILE_PREFIX) + 17) >= (size_t)nBuf ){
-    return SQLITE_ERROR;
-  }
-
+  if( zDir==0 ) return SQLITE_IOERR_GETTEMPPATH;
   do{
-    sqlite3_snprintf(nBuf-17, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX, zDir);
-    j = (int)strlen(zBuf);
-    sqlite3_randomness(15, &zBuf[j]);
-    for(i=0; i<15; i++, j++){
-      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
-    }
-    zBuf[j] = 0;
+    u64 r;
+    sqlite3_randomness(sizeof(r), &r);
+    assert( nBuf>2 );
+    zBuf[nBuf-2] = 0;
+    sqlite3_snprintf(nBuf, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX"%llx%c",
+                     zDir, r, 0);
+    if( zBuf[nBuf-2]!=0 || (iLimit++)>10 ) return SQLITE_ERROR;
   }while( osAccess(zBuf,0)==0 );
   return SQLITE_OK;
 }
@@ -29410,7 +34830,7 @@ static UnixUnusedFd *findReusableFd(const char *zPath, int flags){
   ** descriptor on the same path, fail, and return an error to SQLite.
   **
   ** Even if a subsequent open() call does succeed, the consequences of
-  ** not searching for a resusable file descriptor are not dire.  */
+  ** not searching for a reusable file descriptor are not dire.  */
   if( 0==osStat(zPath, &sStat) ){
     unixInodeInfo *pInode;
 
@@ -29441,12 +34861,10 @@ static UnixUnusedFd *findReusableFd(const char *zPath, int flags){
 ** written to *pMode. If an IO error occurs, an SQLite error code is 
 ** returned and the value of *pMode is not modified.
 **
-** If the file being opened is a temporary file, it is always created with
-** the octal permissions 0600 (read/writable by owner only). If the file
-** is a database or master journal file, it is created with the permissions 
-** mask SQLITE_DEFAULT_FILE_PERMISSIONS.
-**
-** Finally, if the file being opened is a WAL or regular journal file, then 
+** In most cases, this routine sets *pMode to 0, which will become
+** an indication to robust_open() to create the file using
+** SQLITE_DEFAULT_FILE_PERMISSIONS adjusted by the umask.
+** But if the file being opened is a WAL or regular journal file, then 
 ** this function queries the file-system for the permissions on the 
 ** corresponding database file and sets *pMode to this value. Whenever 
 ** possible, WAL and journal files are created using the same permissions 
@@ -29460,10 +34878,14 @@ static UnixUnusedFd *findReusableFd(const char *zPath, int flags){
 static int findCreateFileMode(
   const char *zPath,              /* Path of file (possibly) being created */
   int flags,                      /* Flags passed as 4th argument to xOpen() */
-  mode_t *pMode                   /* OUT: Permissions to open file with */
+  mode_t *pMode,                  /* OUT: Permissions to open file with */
+  uid_t *pUid,                    /* OUT: uid to set on the file */
+  gid_t *pGid                     /* OUT: gid to set on the file */
 ){
   int rc = SQLITE_OK;             /* Return Code */
-  *pMode = SQLITE_DEFAULT_FILE_PERMISSIONS;
+  *pMode = 0;
+  *pUid = 0;
+  *pGid = 0;
   if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
     char zDb[MAX_PATHNAME+1];     /* Database file path */
     int nDb;                      /* Number of valid bytes in zDb */
@@ -29482,21 +34904,26 @@ static int findCreateFileMode(
     ** used by the test_multiplex.c module.
     */
     nDb = sqlite3Strlen30(zPath) - 1; 
-#ifdef SQLITE_ENABLE_8_3_NAMES
-    while( nDb>0 && !sqlite3Isalnum(zPath[nDb]) ) nDb--;
-    if( nDb==0 || zPath[nDb]!='-' ) return SQLITE_OK;
-#else
     while( zPath[nDb]!='-' ){
+#ifndef SQLITE_ENABLE_8_3_NAMES
+      /* In the normal case (8+3 filenames disabled) the journal filename
+      ** is guaranteed to contain a '-' character. */
       assert( nDb>0 );
-      assert( zPath[nDb]!='\n' );
+      assert( sqlite3Isalnum(zPath[nDb]) );
+#else
+      /* If 8+3 names are possible, then the journal file might not contain
+      ** a '-' character.  So check for that case and return early. */
+      if( nDb==0 || zPath[nDb]=='.' ) return SQLITE_OK;
+#endif
       nDb--;
     }
-#endif
     memcpy(zDb, zPath, nDb);
     zDb[nDb] = '\0';
 
     if( 0==osStat(zDb, &sStat) ){
       *pMode = sStat.st_mode & 0777;
+      *pUid = sStat.st_uid;
+      *pGid = sStat.st_gid;
     }else{
       rc = SQLITE_IOERR_FSTAT;
     }
@@ -29541,6 +34968,7 @@ static int unixOpen(
   int eType = flags&0xFFFFFF00;  /* Type of file to open */
   int noLock;                    /* True to omit locking primitives */
   int rc = SQLITE_OK;            /* Function Return Code */
+  int ctrlFlags = 0;             /* UNIXFILE_* flags */
 
   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
@@ -29567,7 +34995,7 @@ static int unixOpen(
   /* If argument zPath is a NULL pointer, this function is required to open
   ** a temporary file. Use this buffer to store the file name in.
   */
-  char zTmpname[MAX_PATHNAME+1];
+  char zTmpname[MAX_PATHNAME+2];
   const char *zName = zPath;
 
   /* Check the following statements are true: 
@@ -29596,6 +35024,16 @@ static int unixOpen(
        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
   );
 
+  /* Detect a pid change and reset the PRNG.  There is a race condition
+  ** here such that two or more threads all trying to open databases at
+  ** the same instant might all reset the PRNG.  But multiple resets
+  ** are harmless.
+  */
+  if( randomnessPid!=osGetpid(0) ){
+    randomnessPid = osGetpid(0);
+    sqlite3_randomness(0,0);
+  }
+
   memset(p, 0, sizeof(unixFile));
 
   if( eType==SQLITE_OPEN_MAIN_DB ){
@@ -29604,20 +35042,30 @@ static int unixOpen(
     if( pUnused ){
       fd = pUnused->fd;
     }else{
-      pUnused = sqlite3_malloc(sizeof(*pUnused));
+      pUnused = sqlite3_malloc64(sizeof(*pUnused));
       if( !pUnused ){
-        return SQLITE_NOMEM;
+        return SQLITE_NOMEM_BKPT;
       }
     }
     p->pUnused = pUnused;
+
+    /* Database filenames are double-zero terminated if they are not
+    ** URIs with parameters.  Hence, they can always be passed into
+    ** sqlite3_uri_parameter(). */
+    assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );
+
   }else if( !zName ){
     /* If zName is NULL, the upper layer is requesting a temp file. */
     assert(isDelete && !syncDir);
-    rc = unixGetTempname(MAX_PATHNAME+1, zTmpname);
+    rc = unixGetTempname(pVfs->mxPathname, zTmpname);
     if( rc!=SQLITE_OK ){
       return rc;
     }
     zName = zTmpname;
+
+    /* Generated temporary filenames are always double-zero terminated
+    ** for use by sqlite3_uri_parameter(). */
+    assert( zName[strlen(zName)+1]==0 );
   }
 
   /* Determine the value of the flags parameter passed to POSIX function
@@ -29632,7 +35080,9 @@ static int unixOpen(
 
   if( fd<0 ){
     mode_t openMode;              /* Permissions to create file with */
-    rc = findCreateFileMode(zName, flags, &openMode);
+    uid_t uid;                    /* Userid for the file */
+    gid_t gid;                    /* Groupid for the file */
+    rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);
     if( rc!=SQLITE_OK ){
       assert( !p->pUnused );
       assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
@@ -29640,7 +35090,8 @@ static int unixOpen(
     }
     fd = robust_open(zName, openFlags, openMode);
     OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
-    if( fd<0 && errno!=EISDIR && isReadWrite && !isExclusive ){
+    assert( !isExclusive || (openFlags & O_CREAT)!=0 );
+    if( fd<0 && errno!=EISDIR && isReadWrite ){
       /* Failed to open the file for read/write access. Try read-only. */
       flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
       openFlags &= ~(O_RDWR|O_CREAT);
@@ -29653,6 +35104,14 @@ static int unixOpen(
       rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);
       goto open_finished;
     }
+
+    /* If this process is running as root and if creating a new rollback
+    ** journal or WAL file, set the ownership of the journal or WAL to be
+    ** the same as the original database.
+    */
+    if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){
+      robustFchown(fd, uid, gid);
+    }
   }
   assert( fd>=0 );
   if( pOutFlags ){
@@ -29667,6 +35126,12 @@ static int unixOpen(
   if( isDelete ){
 #if OS_VXWORKS
     zPath = zName;
+#elif defined(SQLITE_UNLINK_AFTER_CLOSE)
+    zPath = sqlite3_mprintf("%s", zName);
+    if( zPath==0 ){
+      robust_close(p, fd, __LINE__);
+      return SQLITE_NOMEM_BKPT;
+    }
 #else
     osUnlink(zName);
 #endif
@@ -29676,25 +35141,29 @@ static int unixOpen(
     p->openFlags = openFlags;
   }
 #endif
-
-#ifdef FD_CLOEXEC
-  osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
-#endif
-
-  noLock = eType!=SQLITE_OPEN_MAIN_DB;
-
   
 #if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE
   if( fstatfs(fd, &fsInfo) == -1 ){
-    ((unixFile*)pFile)->lastErrno = errno;
+    storeLastErrno(p, errno);
     robust_close(p, fd, __LINE__);
     return SQLITE_IOERR_ACCESS;
   }
   if (0 == strncmp("msdos", fsInfo.f_fstypename, 5)) {
     ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
   }
+  if (0 == strncmp("exfat", fsInfo.f_fstypename, 5)) {
+    ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;
+  }
 #endif
-  
+
+  /* Set up appropriate ctrlFlags */
+  if( isDelete )                ctrlFlags |= UNIXFILE_DELETE;
+  if( isReadonly )              ctrlFlags |= UNIXFILE_RDONLY;
+  noLock = eType!=SQLITE_OPEN_MAIN_DB;
+  if( noLock )                  ctrlFlags |= UNIXFILE_NOLOCK;
+  if( syncDir )                 ctrlFlags |= UNIXFILE_DIRSYNC;
+  if( flags & SQLITE_OPEN_URI ) ctrlFlags |= UNIXFILE_URI;
+
 #if SQLITE_ENABLE_LOCKING_STYLE
 #if SQLITE_PREFER_PROXY_LOCKING
   isAutoProxy = 1;
@@ -29708,24 +35177,10 @@ static int unixOpen(
     if( envforce!=NULL ){
       useProxy = atoi(envforce)>0;
     }else{
-      if( statfs(zPath, &fsInfo) == -1 ){
-        /* In theory, the close(fd) call is sub-optimal. If the file opened
-        ** with fd is a database file, and there are other connections open
-        ** on that file that are currently holding advisory locks on it,
-        ** then the call to close() will cancel those locks. In practice,
-        ** we're assuming that statfs() doesn't fail very often. At least
-        ** not while other file descriptors opened by the same process on
-        ** the same file are working.  */
-        p->lastErrno = errno;
-        robust_close(p, fd, __LINE__);
-        rc = SQLITE_IOERR_ACCESS;
-        goto open_finished;
-      }
       useProxy = !(fsInfo.f_flags&MNT_LOCAL);
     }
     if( useProxy ){
-      rc = fillInUnixFile(pVfs, fd, syncDir, pFile, zPath, noLock,
-                          isDelete, isReadonly);
+      rc = fillInUnixFile(pVfs, fd, pFile, zPath, ctrlFlags);
       if( rc==SQLITE_OK ){
         rc = proxyTransformUnixFile((unixFile*)pFile, ":auto:");
         if( rc!=SQLITE_OK ){
@@ -29742,8 +35197,8 @@ static int unixOpen(
   }
 #endif
   
-  rc = fillInUnixFile(pVfs, fd, syncDir, pFile, zPath, noLock,
-                      isDelete, isReadonly);
+  rc = fillInUnixFile(pVfs, fd, pFile, zPath, ctrlFlags);
+
 open_finished:
   if( rc!=SQLITE_OK ){
     sqlite3_free(p->pUnused);
@@ -29764,24 +35219,29 @@ static int unixDelete(
   int rc = SQLITE_OK;
   UNUSED_PARAMETER(NotUsed);
   SimulateIOError(return SQLITE_IOERR_DELETE);
-  if( osUnlink(zPath)==(-1) && errno!=ENOENT ){
-    return unixLogError(SQLITE_IOERR_DELETE, "unlink", zPath);
+  if( osUnlink(zPath)==(-1) ){
+    if( errno==ENOENT
+#if OS_VXWORKS
+        || osAccess(zPath,0)!=0
+#endif
+    ){
+      rc = SQLITE_IOERR_DELETE_NOENT;
+    }else{
+      rc = unixLogError(SQLITE_IOERR_DELETE, "unlink", zPath);
+    }
+    return rc;
   }
 #ifndef SQLITE_DISABLE_DIRSYNC
-  if( dirSync ){
+  if( (dirSync & 1)!=0 ){
     int fd;
     rc = osOpenDirectory(zPath, &fd);
     if( rc==SQLITE_OK ){
-#if OS_VXWORKS
-      if( fsync(fd)==-1 )
-#else
-      if( fsync(fd) )
-#endif
-      {
+      if( full_fsync(fd,0,0) ){
         rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);
       }
       robust_close(0, fd, __LINE__);
-    }else if( rc==SQLITE_CANTOPEN ){
+    }else{
+      assert( rc==SQLITE_CANTOPEN );
       rc = SQLITE_OK;
     }
   }
@@ -29790,7 +35250,7 @@ static int unixDelete(
 }
 
 /*
-** Test the existance of or access permissions of file zPath. The
+** Test the existence of or access permissions of file zPath. The
 ** test performed depends on the value of flags:
 **
 **     SQLITE_ACCESS_EXISTS: Return 1 if the file exists
@@ -29805,33 +35265,49 @@ static int unixAccess(
   int flags,              /* What do we want to learn about the zPath file? */
   int *pResOut            /* Write result boolean here */
 ){
-  int amode = 0;
   UNUSED_PARAMETER(NotUsed);
   SimulateIOError( return SQLITE_IOERR_ACCESS; );
-  switch( flags ){
-    case SQLITE_ACCESS_EXISTS:
-      amode = F_OK;
-      break;
-    case SQLITE_ACCESS_READWRITE:
-      amode = W_OK|R_OK;
-      break;
-    case SQLITE_ACCESS_READ:
-      amode = R_OK;
-      break;
+  assert( pResOut!=0 );
 
-    default:
-      assert(!"Invalid flags argument");
-  }
-  *pResOut = (osAccess(zPath, amode)==0);
-  if( flags==SQLITE_ACCESS_EXISTS && *pResOut ){
+  /* The spec says there are three possible values for flags.  But only
+  ** two of them are actually used */
+  assert( flags==SQLITE_ACCESS_EXISTS || flags==SQLITE_ACCESS_READWRITE );
+
+  if( flags==SQLITE_ACCESS_EXISTS ){
     struct stat buf;
-    if( 0==osStat(zPath, &buf) && buf.st_size==0 ){
-      *pResOut = 0;
-    }
+    *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
+  }else{
+    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
   }
   return SQLITE_OK;
 }
 
+/*
+**
+*/
+static int mkFullPathname(
+  const char *zPath,              /* Input path */
+  char *zOut,                     /* Output buffer */
+  int nOut                        /* Allocated size of buffer zOut */
+){
+  int nPath = sqlite3Strlen30(zPath);
+  int iOff = 0;
+  if( zPath[0]!='/' ){
+    if( osGetcwd(zOut, nOut-2)==0 ){
+      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
+    }
+    iOff = sqlite3Strlen30(zOut);
+    zOut[iOff++] = '/';
+  }
+  if( (iOff+nPath+1)>nOut ){
+    /* SQLite assumes that xFullPathname() nul-terminates the output buffer
+    ** even if it returns an error.  */
+    zOut[iOff] = '\0';
+    return SQLITE_CANTOPEN_BKPT;
+  }
+  sqlite3_snprintf(nOut-iOff, &zOut[iOff], "%s", zPath);
+  return SQLITE_OK;
+}
 
 /*
 ** Turn a relative pathname into a full pathname. The relative path
@@ -29848,6 +35324,17 @@ static int unixFullPathname(
   int nOut,                     /* Size of output buffer in bytes */
   char *zOut                    /* Output buffer */
 ){
+#if !defined(HAVE_READLINK) || !defined(HAVE_LSTAT)
+  return mkFullPathname(zPath, zOut, nOut);
+#else
+  int rc = SQLITE_OK;
+  int nByte;
+  int nLink = 1;                /* Number of symbolic links followed so far */
+  const char *zIn = zPath;      /* Input path for each iteration of loop */
+  char *zDel = 0;
+
+  assert( pVfs->mxPathname==MAX_PATHNAME );
+  UNUSED_PARAMETER(pVfs);
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
@@ -29856,21 +35343,62 @@ static int unixFullPathname(
   */
   SimulateIOError( return SQLITE_ERROR );
 
-  assert( pVfs->mxPathname==MAX_PATHNAME );
-  UNUSED_PARAMETER(pVfs);
+  do {
 
-  zOut[nOut-1] = '\0';
-  if( zPath[0]=='/' ){
-    sqlite3_snprintf(nOut, zOut, "%s", zPath);
-  }else{
-    int nCwd;
-    if( osGetcwd(zOut, nOut-1)==0 ){
-      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
+    /* Call stat() on path zIn. Set bLink to true if the path is a symbolic
+    ** link, or false otherwise.  */
+    int bLink = 0;
+    struct stat buf;
+    if( osLstat(zIn, &buf)!=0 ){
+      if( errno!=ENOENT ){
+        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "lstat", zIn);
+      }
+    }else{
+      bLink = S_ISLNK(buf.st_mode);
     }
-    nCwd = (int)strlen(zOut);
-    sqlite3_snprintf(nOut-nCwd, &zOut[nCwd], "/%s", zPath);
-  }
-  return SQLITE_OK;
+
+    if( bLink ){
+      if( zDel==0 ){
+        zDel = sqlite3_malloc(nOut);
+        if( zDel==0 ) rc = SQLITE_NOMEM_BKPT;
+      }else if( ++nLink>SQLITE_MAX_SYMLINKS ){
+        rc = SQLITE_CANTOPEN_BKPT;
+      }
+
+      if( rc==SQLITE_OK ){
+        nByte = osReadlink(zIn, zDel, nOut-1);
+        if( nByte<0 ){
+          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zIn);
+        }else{
+          if( zDel[0]!='/' ){
+            int n;
+            for(n = sqlite3Strlen30(zIn); n>0 && zIn[n-1]!='/'; n--);
+            if( nByte+n+1>nOut ){
+              rc = SQLITE_CANTOPEN_BKPT;
+            }else{
+              memmove(&zDel[n], zDel, nByte+1);
+              memcpy(zDel, zIn, n);
+              nByte += n;
+            }
+          }
+          zDel[nByte] = '\0';
+        }
+      }
+
+      zIn = zDel;
+    }
+
+    assert( rc!=SQLITE_OK || zIn!=zOut || zIn[0]=='/' );
+    if( rc==SQLITE_OK && zIn!=zOut ){
+      rc = mkFullPathname(zIn, zOut, nOut);
+    }
+    if( bLink==0 ) break;
+    zIn = zOut;
+  }while( rc==SQLITE_OK );
+
+  sqlite3_free(zDel);
+  return rc;
+#endif   /* HAVE_READLINK && HAVE_LSTAT */
 }
 
 
@@ -29956,20 +35484,20 @@ static int unixRandomness(sqlite3_vfs *NotUsed, int nBuf, char *zBuf){
   ** tests repeatable.
   */
   memset(zBuf, 0, nBuf);
-#if !defined(SQLITE_TEST)
+  randomnessPid = osGetpid(0);  
+#if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
   {
-    int pid, fd;
+    int fd, got;
     fd = robust_open("/dev/urandom", O_RDONLY, 0);
     if( fd<0 ){
       time_t t;
       time(&t);
       memcpy(zBuf, &t, sizeof(t));
-      pid = getpid();
-      memcpy(&zBuf[sizeof(t)], &pid, sizeof(pid));
-      assert( sizeof(t)+sizeof(pid)<=(size_t)nBuf );
-      nBuf = sizeof(t) + sizeof(pid);
+      memcpy(&zBuf[sizeof(t)], &randomnessPid, sizeof(randomnessPid));
+      assert( sizeof(t)+sizeof(randomnessPid)<=(size_t)nBuf );
+      nBuf = sizeof(t) + sizeof(randomnessPid);
     }else{
-      do{ nBuf = osRead(fd, zBuf, nBuf); }while( nBuf<0 && errno==EINTR );
+      do{ got = osRead(fd, zBuf, nBuf); }while( got<0 && errno==EINTR );
       robust_close(0, fd, __LINE__);
     }
   }
@@ -30039,11 +35567,8 @@ static int unixCurrentTimeInt64(sqlite3_vfs *NotUsed, sqlite3_int64 *piNow){
   *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_nsec/1000000;
 #else
   struct timeval sNow;
-  if( gettimeofday(&sNow, 0)==0 ){
-    *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;
-  }else{
-    rc = SQLITE_ERROR;
-  }
+  (void)gettimeofday(&sNow, 0);  /* Cannot fail given valid arguments */
+  *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;
 #endif
 
 #ifdef SQLITE_TEST
@@ -30055,6 +35580,7 @@ static int unixCurrentTimeInt64(sqlite3_vfs *NotUsed, sqlite3_int64 *piNow){
   return rc;
 }
 
+#ifndef SQLITE_OMIT_DEPRECATED
 /*
 ** Find the current time (in Universal Coordinated Time).  Write the
 ** current time and date as a Julian Day number into *prNow and
@@ -30068,19 +35594,21 @@ static int unixCurrentTime(sqlite3_vfs *NotUsed, double *prNow){
   *prNow = i/86400000.0;
   return rc;
 }
+#else
+# define unixCurrentTime 0
+#endif
 
 /*
-** We added the xGetLastError() method with the intention of providing
-** better low-level error messages when operating-system problems come up
-** during SQLite operation.  But so far, none of that has been implemented
-** in the core.  So this routine is never called.  For now, it is merely
-** a place-holder.
+** The xGetLastError() method is designed to return a better
+** low-level error message when operating-system problems come up
+** during SQLite operation.  Only the integer return code is currently
+** used.
 */
 static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
   UNUSED_PARAMETER(NotUsed);
   UNUSED_PARAMETER(NotUsed2);
   UNUSED_PARAMETER(NotUsed3);
-  return 0;
+  return errno;
 }
 
 
@@ -30112,7 +35640,7 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 ** address in the shared range is taken for a SHARED lock, the entire
 ** shared range is taken for an EXCLUSIVE lock):
 **
-**      PENDING_BYTE        0x40000000		   	
+**      PENDING_BYTE        0x40000000
 **      RESERVED_BYTE       0x40000001
 **      SHARED_RANGE        0x40000002 -> 0x40000200
 **
@@ -30138,9 +35666,10 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 **
 ** C APIs
 **
-**  sqlite3_file_control(db, dbname, SQLITE_SET_LOCKPROXYFILE,
+**  sqlite3_file_control(db, dbname, SQLITE_FCNTL_SET_LOCKPROXYFILE,
 **                       <proxy_path> | ":auto:");
-**  sqlite3_file_control(db, dbname, SQLITE_GET_LOCKPROXYFILE, &<proxy_path>);
+**  sqlite3_file_control(db, dbname, SQLITE_FCNTL_GET_LOCKPROXYFILE,
+**                       &<proxy_path>);
 **
 **
 ** SQL pragmas
@@ -30181,7 +35710,7 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 ** proxy path against the values stored in the conch.  The conch file is
 ** stored in the same directory as the database file and the file name
 ** is patterned after the database file name as ".<databasename>-conch".
-** If the conch file does not exist, or it's contents do not match the
+** If the conch file does not exist, or its contents do not match the
 ** host ID and/or proxy path, then the lock is escalated to an exclusive
 ** lock and the conch file contents is updated with the host ID and proxy
 ** path and the lock is downgraded to a shared lock again.  If the conch
@@ -30233,7 +35762,7 @@ static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){
 ** setting the environment variable SQLITE_FORCE_PROXY_LOCKING to 1 will
 ** force proxy locking to be used for every database file opened, and 0
 ** will force automatic proxy locking to be disabled for all database
-** files (explicity calling the SQLITE_SET_LOCKPROXYFILE pragma or
+** files (explicitly calling the SQLITE_FCNTL_SET_LOCKPROXYFILE pragma or
 ** sqlite_file_control API is not affected by SQLITE_FORCE_PROXY_LOCKING).
 */
 
@@ -30254,6 +35783,7 @@ struct proxyLockingContext {
   char *lockProxyPath;         /* Name of the proxy lock file */
   char *dbPath;                /* Name of the open file */
   int conchHeld;               /* 1 if the conch is held, -1 if lockless */
+  int nFails;                  /* Number of conch taking failures */
   void *oldLockingContext;     /* Original lockingcontext to restore on close */
   sqlite3_io_methods const *pOldMethod;     /* Original I/O methods for close */
 };
@@ -30275,7 +35805,7 @@ static int proxyGetLockPath(const char *dbPath, char *lPath, size_t maxLen){
   {
     if( !confstr(_CS_DARWIN_USER_TEMP_DIR, lPath, maxLen) ){
       OSTRACE(("GETLOCKPATH  failed %s errno=%d pid=%d\n",
-               lPath, errno, getpid()));
+               lPath, errno, osGetpid(0)));
       return SQLITE_IOERR_LOCK;
     }
     len = strlcat(lPath, "sqliteplocks", maxLen);    
@@ -30297,7 +35827,7 @@ static int proxyGetLockPath(const char *dbPath, char *lPath, size_t maxLen){
   }
   lPath[i+len]='\0';
   strlcat(lPath, ":auto:", maxLen);
-  OSTRACE(("GETLOCKPATH  proxy lock path=%s pid=%d\n", lPath, getpid()));
+  OSTRACE(("GETLOCKPATH  proxy lock path=%s pid=%d\n", lPath, osGetpid(0)));
   return SQLITE_OK;
 }
 
@@ -30319,12 +35849,12 @@ static int proxyCreateLockPath(const char *lockPath){
       if( i-start>2 || (i-start==1 && buf[start] != '.' && buf[start] != '/') 
          || (i-start==2 && buf[start] != '.' && buf[start+1] != '.') ){
         buf[i]='\0';
-        if( mkdir(buf, SQLITE_DEFAULT_PROXYDIR_PERMISSIONS) ){
+        if( osMkdir(buf, SQLITE_DEFAULT_PROXYDIR_PERMISSIONS) ){
           int err=errno;
           if( err!=EEXIST ) {
             OSTRACE(("CREATELOCKPATH  FAILED creating %s, "
                      "'%s' proxy lock path=%s pid=%d\n",
-                     buf, strerror(err), lockPath, getpid()));
+                     buf, strerror(err), lockPath, osGetpid(0)));
             return err;
           }
         }
@@ -30333,7 +35863,7 @@ static int proxyCreateLockPath(const char *lockPath){
     }
     buf[i] = lockPath[i];
   }
-  OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n", lockPath, getpid()));
+  OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n",lockPath,osGetpid(0)));
   return 0;
 }
 
@@ -30367,23 +35897,23 @@ static int proxyCreateUnixFile(
   if( pUnused ){
     fd = pUnused->fd;
   }else{
-    pUnused = sqlite3_malloc(sizeof(*pUnused));
+    pUnused = sqlite3_malloc64(sizeof(*pUnused));
     if( !pUnused ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   }
   if( fd<0 ){
-    fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
+    fd = robust_open(path, openFlags, 0);
     terrno = errno;
     if( fd<0 && errno==ENOENT && islockfile ){
       if( proxyCreateLockPath(path) == SQLITE_OK ){
-        fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
+        fd = robust_open(path, openFlags, 0);
       }
     }
   }
   if( fd<0 ){
     openFlags = O_RDONLY;
-    fd = robust_open(path, openFlags, SQLITE_DEFAULT_FILE_PERMISSIONS);
+    fd = robust_open(path, openFlags, 0);
     terrno = errno;
   }
   if( fd<0 ){
@@ -30400,9 +35930,9 @@ static int proxyCreateUnixFile(
     }
   }
   
-  pNew = (unixFile *)sqlite3_malloc(sizeof(*pNew));
+  pNew = (unixFile *)sqlite3_malloc64(sizeof(*pNew));
   if( pNew==NULL ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto end_create_proxy;
   }
   memset(pNew, 0, sizeof(unixFile));
@@ -30414,7 +35944,7 @@ static int proxyCreateUnixFile(
   pUnused->flags = openFlags;
   pNew->pUnused = pUnused;
   
-  rc = fillInUnixFile(&dummyVfs, fd, 0, (sqlite3_file*)pNew, path, 0, 0, 0);
+  rc = fillInUnixFile(&dummyVfs, fd, (sqlite3_file*)pNew, path, 0);
   if( rc==SQLITE_OK ){
     *ppFile = pNew;
     return SQLITE_OK;
@@ -30433,8 +35963,10 @@ SQLITE_API int sqlite3_hostid_num = 0;
 
 #define PROXY_HOSTIDLEN    16  /* conch file host id length */
 
+#ifdef HAVE_GETHOSTUUID
 /* Not always defined in the headers as it ought to be */
 extern int gethostuuid(uuid_t id, const struct timespec *wait);
+#endif
 
 /* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 
 ** bytes of writable memory.
@@ -30442,10 +35974,9 @@ extern int gethostuuid(uuid_t id, const struct timespec *wait);
 static int proxyGetHostID(unsigned char *pHostID, int *pError){
   assert(PROXY_HOSTIDLEN == sizeof(uuid_t));
   memset(pHostID, 0, PROXY_HOSTIDLEN);
-#if defined(__MAX_OS_X_VERSION_MIN_REQUIRED)\
-               && __MAC_OS_X_VERSION_MIN_REQUIRED<1050
+#ifdef HAVE_GETHOSTUUID
   {
-    static const struct timespec timeout = {1, 0}; /* 1 sec timeout */
+    struct timespec timeout = {1, 0}; /* 1 sec timeout */
     if( gethostuuid(pHostID, &timeout) ){
       int err = errno;
       if( pError ){
@@ -30507,8 +36038,7 @@ static int proxyBreakConchLock(unixFile *pFile, uuid_t myHostID){
     goto end_breaklock;
   }
   /* write it out to the temporary break file */
-  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL),
-                   SQLITE_DEFAULT_FILE_PERMISSIONS);
+  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL), 0);
   if( fd<0 ){
     sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);
     goto end_breaklock;
@@ -30561,7 +36091,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
        */
       struct stat buf;
       if( osFstat(conchFile->h, &buf) ){
-        pFile->lastErrno = errno;
+        storeLastErrno(pFile, errno);
         return SQLITE_IOERR_LOCK;
       }
       
@@ -30581,7 +36111,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
         char tBuf[PROXY_MAXCONCHLEN];
         int len = osPread(conchFile->h, tBuf, PROXY_MAXCONCHLEN, 0);
         if( len<0 ){
-          pFile->lastErrno = errno;
+          storeLastErrno(pFile, errno);
           return SQLITE_IOERR_LOCK;
         }
         if( len>PROXY_PATHINDEX && tBuf[0]==(char)PROXY_CONCHVERSION){
@@ -30601,7 +36131,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
       if( 0==proxyBreakConchLock(pFile, myHostID) ){
         rc = SQLITE_OK;
         if( lockType==EXCLUSIVE_LOCK ){
-          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);          
+          rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);
         }
         if( !rc ){
           rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);
@@ -30639,11 +36169,12 @@ static int proxyTakeConch(unixFile *pFile){
     int forceNewLockPath = 0;
     
     OSTRACE(("TAKECONCH  %d for %s pid=%d\n", conchFile->h,
-             (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"), getpid()));
+             (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"),
+             osGetpid(0)));
 
     rc = proxyGetHostID(myHostID, &pError);
     if( (rc&0xff)==SQLITE_IOERR ){
-      pFile->lastErrno = pError;
+      storeLastErrno(pFile, pError);
       goto end_takeconch;
     }
     rc = proxyConchLock(pFile, myHostID, SHARED_LOCK);
@@ -30654,7 +36185,7 @@ static int proxyTakeConch(unixFile *pFile){
     readLen = seekAndRead((unixFile*)conchFile, 0, readBuf, PROXY_MAXCONCHLEN);
     if( readLen<0 ){
       /* I/O error: lastErrno set by seekAndRead */
-      pFile->lastErrno = conchFile->lastErrno;
+      storeLastErrno(pFile, conchFile->lastErrno);
       rc = SQLITE_IOERR_READ;
       goto end_takeconch;
     }else if( readLen<=(PROXY_HEADERLEN+PROXY_HOSTIDLEN) || 
@@ -30727,7 +36258,7 @@ static int proxyTakeConch(unixFile *pFile){
           rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
         }
       }else{
-        rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, EXCLUSIVE_LOCK);
+        rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
       }
       if( rc==SQLITE_OK ){
         char writeBuffer[PROXY_MAXCONCHLEN];
@@ -30736,14 +36267,15 @@ static int proxyTakeConch(unixFile *pFile){
         writeBuffer[0] = (char)PROXY_CONCHVERSION;
         memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);
         if( pCtx->lockProxyPath!=NULL ){
-          strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath, MAXPATHLEN);
+          strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath,
+                  MAXPATHLEN);
         }else{
           strlcpy(&writeBuffer[PROXY_PATHINDEX], tempLockPath, MAXPATHLEN);
         }
         writeSize = PROXY_PATHINDEX + strlen(&writeBuffer[PROXY_PATHINDEX]);
         robust_ftruncate(conchFile->h, writeSize);
         rc = unixWrite((sqlite3_file *)conchFile, writeBuffer, writeSize, 0);
-        fsync(conchFile->h);
+        full_fsync(conchFile->h,0,0);
         /* If we created a new conch file (not just updated the contents of a 
          ** valid conch file), try to match the permissions of the database 
          */
@@ -30785,8 +36317,7 @@ static int proxyTakeConch(unixFile *pFile){
           robust_close(pFile, pFile->h, __LINE__);
         }
         pFile->h = -1;
-        fd = robust_open(pCtx->dbPath, pFile->openFlags,
-                      SQLITE_DEFAULT_FILE_PERMISSIONS);
+        fd = robust_open(pCtx->dbPath, pFile->openFlags, 0);
         OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));
         if( fd>=0 ){
           pFile->h = fd;
@@ -30814,7 +36345,7 @@ static int proxyTakeConch(unixFile *pFile){
         if( tempLockPath ){
           pCtx->lockProxyPath = sqlite3DbStrDup(0, tempLockPath);
           if( !pCtx->lockProxyPath ){
-            rc = SQLITE_NOMEM;
+            rc = SQLITE_NOMEM_BKPT;
           }
         }
       }
@@ -30849,7 +36380,7 @@ static int proxyReleaseConch(unixFile *pFile){
   conchFile = pCtx->conchFile;
   OSTRACE(("RELEASECONCH  %d for %s pid=%d\n", conchFile->h,
            (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"), 
-           getpid()));
+           osGetpid(0)));
   if( pCtx->conchHeld>0 ){
     rc = conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, NO_LOCK);
   }
@@ -30861,7 +36392,7 @@ static int proxyReleaseConch(unixFile *pFile){
 
 /*
 ** Given the name of a database file, compute the name of its conch file.
-** Store the conch filename in memory obtained from sqlite3_malloc().
+** Store the conch filename in memory obtained from sqlite3_malloc64().
 ** Make *pConchPath point to the new name.  Return SQLITE_OK on success
 ** or SQLITE_NOMEM if unable to obtain memory.
 **
@@ -30877,9 +36408,9 @@ static int proxyCreateConchPathname(char *dbPath, char **pConchPath){
 
   /* Allocate space for the conch filename and initialize the name to
   ** the name of the original database file. */  
-  *pConchPath = conchPath = (char *)sqlite3_malloc(len + 8);
+  *pConchPath = conchPath = (char *)sqlite3_malloc64(len + 8);
   if( conchPath==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memcpy(conchPath, dbPath, len+1);
   
@@ -30949,7 +36480,8 @@ static int proxyGetDbPathForUnixFile(unixFile *pFile, char *dbPath){
     /* afp style keeps a reference to the db path in the filePath field 
     ** of the struct */
     assert( (int)strlen((char*)pFile->lockingContext)<=MAXPATHLEN );
-    strlcpy(dbPath, ((afpLockingContext *)pFile->lockingContext)->dbPath, MAXPATHLEN);
+    strlcpy(dbPath, ((afpLockingContext *)pFile->lockingContext)->dbPath,
+            MAXPATHLEN);
   } else
 #endif
   if( pFile->pMethod == &dotlockIoMethods ){
@@ -30990,11 +36522,11 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
   }
   
   OSTRACE(("TRANSPROXY  %d for %s pid=%d\n", pFile->h,
-           (lockPath ? lockPath : ":auto:"), getpid()));
+           (lockPath ? lockPath : ":auto:"), osGetpid(0)));
 
-  pCtx = sqlite3_malloc( sizeof(*pCtx) );
+  pCtx = sqlite3_malloc64( sizeof(*pCtx) );
   if( pCtx==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memset(pCtx, 0, sizeof(*pCtx));
 
@@ -31030,7 +36562,7 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
   if( rc==SQLITE_OK ){
     pCtx->dbPath = sqlite3DbStrDup(0, dbPath);
     if( pCtx->dbPath==NULL ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
   if( rc==SQLITE_OK ){
@@ -31062,7 +36594,7 @@ static int proxyTransformUnixFile(unixFile *pFile, const char *path) {
 */
 static int proxyFileControl(sqlite3_file *id, int op, void *pArg){
   switch( op ){
-    case SQLITE_GET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_GET_LOCKPROXYFILE: {
       unixFile *pFile = (unixFile*)id;
       if( pFile->pMethod == &proxyIoMethods ){
         proxyLockingContext *pCtx = (proxyLockingContext*)pFile->lockingContext;
@@ -31077,13 +36609,16 @@ static int proxyFileControl(sqlite3_file *id, int op, void *pArg){
       }
       return SQLITE_OK;
     }
-    case SQLITE_SET_LOCKPROXYFILE: {
+    case SQLITE_FCNTL_SET_LOCKPROXYFILE: {
       unixFile *pFile = (unixFile*)id;
       int rc = SQLITE_OK;
       int isProxyStyle = (pFile->pMethod == &proxyIoMethods);
       if( pArg==NULL || (const char *)pArg==0 ){
         if( isProxyStyle ){
-          /* turn off proxy locking - not supported */
+          /* turn off proxy locking - not supported.  If support is added for
+          ** switching proxy locking mode off then it will need to fail if
+          ** the journal mode is WAL mode. 
+          */
           rc = SQLITE_ERROR /*SQLITE_PROTOCOL? SQLITE_MISUSE?*/;
         }else{
           /* turn off proxy locking - already off - NOOP */
@@ -31213,7 +36748,7 @@ static int proxyUnlock(sqlite3_file *id, int eFileLock) {
 ** Close a file that uses proxy locks.
 */
 static int proxyClose(sqlite3_file *id) {
-  if( id ){
+  if( ALWAYS(id) ){
     unixFile *pFile = (unixFile*)id;
     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;
     unixFile *lockProxy = pCtx->lockProxy;
@@ -31274,7 +36809,7 @@ static int proxyClose(sqlite3_file *id) {
 ** necessarily been initialized when this routine is called, and so they
 ** should not be used.
 */
-SQLITE_API int sqlite3_os_init(void){ 
+SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void){ 
   /* 
   ** The following macro defines an initializer for an sqlite3_vfs object.
   ** The name of the VFS is NAME.  The pAppData is a pointer to a pointer
@@ -31328,8 +36863,10 @@ SQLITE_API int sqlite3_os_init(void){
   ** array cannot be const.
   */
   static sqlite3_vfs aVfs[] = {
-#if SQLITE_ENABLE_LOCKING_STYLE && (OS_VXWORKS || defined(__APPLE__))
+#if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
     UNIXVFS("unix",          autolockIoFinder ),
+#elif OS_VXWORKS
+    UNIXVFS("unix",          vxworksIoFinder ),
 #else
     UNIXVFS("unix",          posixIoFinder ),
 #endif
@@ -31339,11 +36876,11 @@ SQLITE_API int sqlite3_os_init(void){
 #if OS_VXWORKS
     UNIXVFS("unix-namedsem", semIoFinder ),
 #endif
-#if SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS
     UNIXVFS("unix-posix",    posixIoFinder ),
-#if !OS_VXWORKS
-    UNIXVFS("unix-flock",    flockIoFinder ),
 #endif
+#if SQLITE_ENABLE_LOCKING_STYLE
+    UNIXVFS("unix-flock",    flockIoFinder ),
 #endif
 #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
     UNIXVFS("unix-afp",      afpIoFinder ),
@@ -31355,7 +36892,7 @@ SQLITE_API int sqlite3_os_init(void){
 
   /* Double-check that the aSyscall[] array has been constructed
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
-  assert( ArraySize(aSyscall)==18 );
+  assert( ArraySize(aSyscall)==28 );
 
   /* Register all VFSes defined in the aVfs[] array */
   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
@@ -31371,7 +36908,7 @@ SQLITE_API int sqlite3_os_init(void){
 ** to release dynamically allocated objects.  But not on unix.
 ** This routine is a no-op for unix.
 */
-SQLITE_API int sqlite3_os_end(void){ 
+SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void){ 
   return SQLITE_OK; 
 }
  
@@ -31391,49 +36928,10 @@ SQLITE_API int sqlite3_os_end(void){
 **
 ******************************************************************************
 **
-** This file contains code that is specific to windows.
+** This file contains code that is specific to Windows.
 */
-#if SQLITE_OS_WIN               /* This file is used for windows only */
-
-
-/*
-** A Note About Memory Allocation:
-**
-** This driver uses malloc()/free() directly rather than going through
-** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers
-** are designed for use on embedded systems where memory is scarce and
-** malloc failures happen frequently.  Win32 does not typically run on
-** embedded systems, and when it does the developers normally have bigger
-** problems to worry about than running out of memory.  So there is not
-** a compelling need to use the wrappers.
-**
-** But there is a good reason to not use the wrappers.  If we use the
-** wrappers then we will get simulated malloc() failures within this
-** driver.  And that causes all kinds of problems for our tests.  We
-** could enhance SQLite to deal with simulated malloc failures within
-** the OS driver, but the code to deal with those failure would not
-** be exercised on Linux (which does not need to malloc() in the driver)
-** and so we would have difficulty writing coverage tests for that
-** code.  Better to leave the code out, we think.
-**
-** The point of this discussion is as follows:  When creating a new
-** OS layer for an embedded system, if you use this file as an example,
-** avoid the use of malloc()/free().  Those routines work ok on windows
-** desktops but not so well in embedded systems.
-*/
-
-#include <winbase.h>
-
-#ifdef __CYGWIN__
-# include <sys/cygwin.h>
-#endif
-
-/*
-** Macros used to determine whether or not to use threads.
-*/
-#if defined(THREADSAFE) && THREADSAFE
-# define SQLITE_W32_THREADS 1
-#endif
+/* #include "sqliteInt.h" */
+#if SQLITE_OS_WIN               /* This file is used for Windows only */
 
 /*
 ** Include code that is common to all os_*.c files
@@ -31471,24 +36969,14 @@ SQLITE_API int sqlite3_os_end(void){
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
-# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
-#else
-# define OSTRACE(X)
-#endif
-
 /*
 ** Macros for performance tracing.  Normally turned off.  Only works
 ** on i486 hardware.
 */
 #ifdef SQLITE_PERFORMANCE_TRACE
 
-/* 
-** hwtime.h contains inline assembler code for implementing 
+/*
+** hwtime.h contains inline assembler code for implementing
 ** high-performance timing routines.
 */
 /************** Include hwtime.h in the middle of os_common.h ****************/
@@ -31508,8 +36996,8 @@ SQLITE_API int sqlite3_os_end(void){
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -31577,7 +37065,7 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in os_common.h ******************/
@@ -31598,14 +37086,14 @@ static sqlite_uint64 g_elapsed;
 ** of code will give us the ability to simulate a disk I/O error.  This
 ** is used for testing the I/O recovery logic.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */
-SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */
-SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */
-SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */
-SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */
-SQLITE_API int sqlite3_diskfull_pending = 0;
-SQLITE_API int sqlite3_diskfull = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_io_error_hit;
+SQLITE_API extern int sqlite3_io_error_hardhit;
+SQLITE_API extern int sqlite3_io_error_pending;
+SQLITE_API extern int sqlite3_io_error_persist;
+SQLITE_API extern int sqlite3_io_error_benign;
+SQLITE_API extern int sqlite3_diskfull_pending;
+SQLITE_API extern int sqlite3_diskfull;
 #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)
 #define SimulateIOError(CODE)  \
   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \
@@ -31631,17 +37119,17 @@ static void local_ioerr(){
 #define SimulateIOErrorBenign(X)
 #define SimulateIOError(A)
 #define SimulateDiskfullError(A)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 /*
 ** When testing, keep a count of the number of open files.
 */
-#ifdef SQLITE_TEST
-SQLITE_API int sqlite3_open_file_count = 0;
+#if defined(SQLITE_TEST)
+SQLITE_API extern int sqlite3_open_file_count;
 #define OpenCounter(X)  sqlite3_open_file_count+=(X)
 #else
 #define OpenCounter(X)
-#endif
+#endif /* defined(SQLITE_TEST) */
 
 #endif /* !defined(_OS_COMMON_H_) */
 
@@ -31649,24 +37137,226 @@ SQLITE_API int sqlite3_open_file_count = 0;
 /************** Continuing where we left off in os_win.c *********************/
 
 /*
-** Some microsoft compilers lack this definition.
+** Include the header file for the Windows VFS.
 */
-#ifndef INVALID_FILE_ATTRIBUTES
-# define INVALID_FILE_ATTRIBUTES ((DWORD)-1) 
+/* #include "os_win.h" */
+
+/*
+** Compiling and using WAL mode requires several APIs that are only
+** available in Windows platforms based on the NT kernel.
+*/
+#if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)
+#  error "WAL mode requires support from the Windows NT kernel, compile\
+ with SQLITE_OMIT_WAL."
+#endif
+
+#if !SQLITE_OS_WINNT && SQLITE_MAX_MMAP_SIZE>0
+#  error "Memory mapped files require support from the Windows NT kernel,\
+ compile with SQLITE_MAX_MMAP_SIZE=0."
 #endif
 
 /*
-** Determine if we are dealing with WindowsCE - which has a much
-** reduced API.
+** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions
+** based on the sub-platform)?
 */
-#if SQLITE_OS_WINCE
-# define AreFileApisANSI() 1
-# define FormatMessageW(a,b,c,d,e,f,g) 0
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(SQLITE_WIN32_NO_ANSI)
+#  define SQLITE_WIN32_HAS_ANSI
 #endif
 
-/* Forward references */
+/*
+** Are most of the Win32 Unicode APIs available (i.e. with certain exceptions
+** based on the sub-platform)?
+*/
+#if (SQLITE_OS_WINCE || SQLITE_OS_WINNT || SQLITE_OS_WINRT) && \
+    !defined(SQLITE_WIN32_NO_WIDE)
+#  define SQLITE_WIN32_HAS_WIDE
+#endif
+
+/*
+** Make sure at least one set of Win32 APIs is available.
+*/
+#if !defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_WIN32_HAS_WIDE)
+#  error "At least one of SQLITE_WIN32_HAS_ANSI and SQLITE_WIN32_HAS_WIDE\
+ must be defined."
+#endif
+
+/*
+** Define the required Windows SDK version constants if they are not
+** already available.
+*/
+#ifndef NTDDI_WIN8
+#  define NTDDI_WIN8                        0x06020000
+#endif
+
+#ifndef NTDDI_WINBLUE
+#  define NTDDI_WINBLUE                     0x06030000
+#endif
+
+#ifndef NTDDI_WINTHRESHOLD
+#  define NTDDI_WINTHRESHOLD                0x06040000
+#endif
+
+/*
+** Check to see if the GetVersionEx[AW] functions are deprecated on the
+** target system.  GetVersionEx was first deprecated in Win8.1.
+*/
+#ifndef SQLITE_WIN32_GETVERSIONEX
+#  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE
+#    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */
+#  else
+#    define SQLITE_WIN32_GETVERSIONEX   1   /* GetVersionEx() is current */
+#  endif
+#endif
+
+/*
+** Check to see if the CreateFileMappingA function is supported on the
+** target system.  It is unavailable when using "mincore.lib" on Win10.
+** When compiling for Windows 10, always assume "mincore.lib" is in use.
+*/
+#ifndef SQLITE_WIN32_CREATEFILEMAPPINGA
+#  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINTHRESHOLD
+#    define SQLITE_WIN32_CREATEFILEMAPPINGA   0
+#  else
+#    define SQLITE_WIN32_CREATEFILEMAPPINGA   1
+#  endif
+#endif
+
+/*
+** This constant should already be defined (in the "WinDef.h" SDK file).
+*/
+#ifndef MAX_PATH
+#  define MAX_PATH                      (260)
+#endif
+
+/*
+** Maximum pathname length (in chars) for Win32.  This should normally be
+** MAX_PATH.
+*/
+#ifndef SQLITE_WIN32_MAX_PATH_CHARS
+#  define SQLITE_WIN32_MAX_PATH_CHARS   (MAX_PATH)
+#endif
+
+/*
+** This constant should already be defined (in the "WinNT.h" SDK file).
+*/
+#ifndef UNICODE_STRING_MAX_CHARS
+#  define UNICODE_STRING_MAX_CHARS      (32767)
+#endif
+
+/*
+** Maximum pathname length (in chars) for WinNT.  This should normally be
+** UNICODE_STRING_MAX_CHARS.
+*/
+#ifndef SQLITE_WINNT_MAX_PATH_CHARS
+#  define SQLITE_WINNT_MAX_PATH_CHARS   (UNICODE_STRING_MAX_CHARS)
+#endif
+
+/*
+** Maximum pathname length (in bytes) for Win32.  The MAX_PATH macro is in
+** characters, so we allocate 4 bytes per character assuming worst-case of
+** 4-bytes-per-character for UTF8.
+*/
+#ifndef SQLITE_WIN32_MAX_PATH_BYTES
+#  define SQLITE_WIN32_MAX_PATH_BYTES   (SQLITE_WIN32_MAX_PATH_CHARS*4)
+#endif
+
+/*
+** Maximum pathname length (in bytes) for WinNT.  This should normally be
+** UNICODE_STRING_MAX_CHARS * sizeof(WCHAR).
+*/
+#ifndef SQLITE_WINNT_MAX_PATH_BYTES
+#  define SQLITE_WINNT_MAX_PATH_BYTES   \
+                            (sizeof(WCHAR) * SQLITE_WINNT_MAX_PATH_CHARS)
+#endif
+
+/*
+** Maximum error message length (in chars) for WinRT.
+*/
+#ifndef SQLITE_WIN32_MAX_ERRMSG_CHARS
+#  define SQLITE_WIN32_MAX_ERRMSG_CHARS (1024)
+#endif
+
+/*
+** Returns non-zero if the character should be treated as a directory
+** separator.
+*/
+#ifndef winIsDirSep
+#  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))
+#endif
+
+/*
+** This macro is used when a local variable is set to a value that is
+** [sometimes] not used by the code (e.g. via conditional compilation).
+*/
+#ifndef UNUSED_VARIABLE_VALUE
+#  define UNUSED_VARIABLE_VALUE(x)      (void)(x)
+#endif
+
+/*
+** Returns the character that should be used as the directory separator.
+*/
+#ifndef winGetDirSep
+#  define winGetDirSep()                '\\'
+#endif
+
+/*
+** Do we need to manually define the Win32 file mapping APIs for use with WAL
+** mode or memory mapped files (e.g. these APIs are available in the Windows
+** CE SDK; however, they are not present in the header file)?
+*/
+#if SQLITE_WIN32_FILEMAPPING_API && \
+        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
+/*
+** Two of the file mapping APIs are different under WinRT.  Figure out which
+** set we need.
+*/
+#if SQLITE_OS_WINRT
+WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \
+        LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);
+
+WINBASEAPI LPVOID WINAPI MapViewOfFileFromApp(HANDLE, ULONG, ULONG64, SIZE_T);
+#else
+#if defined(SQLITE_WIN32_HAS_ANSI)
+WINBASEAPI HANDLE WINAPI CreateFileMappingA(HANDLE, LPSECURITY_ATTRIBUTES, \
+        DWORD, DWORD, DWORD, LPCSTR);
+#endif /* defined(SQLITE_WIN32_HAS_ANSI) */
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+WINBASEAPI HANDLE WINAPI CreateFileMappingW(HANDLE, LPSECURITY_ATTRIBUTES, \
+        DWORD, DWORD, DWORD, LPCWSTR);
+#endif /* defined(SQLITE_WIN32_HAS_WIDE) */
+
+WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
+#endif /* SQLITE_OS_WINRT */
+
+/*
+** These file mapping APIs are common to both Win32 and WinRT.
+*/
+
+WINBASEAPI BOOL WINAPI FlushViewOfFile(LPCVOID, SIZE_T);
+WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
+#endif /* SQLITE_WIN32_FILEMAPPING_API */
+
+/*
+** Some Microsoft compilers lack this definition.
+*/
+#ifndef INVALID_FILE_ATTRIBUTES
+# define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
+#endif
+
+#ifndef FILE_FLAG_MASK
+# define FILE_FLAG_MASK          (0xFF3C0000)
+#endif
+
+#ifndef FILE_ATTRIBUTE_MASK
+# define FILE_ATTRIBUTE_MASK     (0x0003FFF7)
+#endif
+
+#ifndef SQLITE_OMIT_WAL
+/* Forward references to structures used for WAL */
 typedef struct winShm winShm;           /* A connection to shared-memory */
 typedef struct winShmNode winShmNode;   /* A region of shared-memory */
+#endif
 
 /*
 ** WinCE lacks native support for file locking so we have to fake it
@@ -31692,31 +37382,112 @@ struct winFile {
   HANDLE h;               /* Handle for accessing the file */
   u8 locktype;            /* Type of lock currently held on this file */
   short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
-  u8 bPersistWal;         /* True to persist WAL files */
+  u8 ctrlFlags;           /* Flags.  See WINFILE_* below */
   DWORD lastErrno;        /* The Windows errno from the last I/O error */
-  DWORD sectorSize;       /* Sector size of the device file is on */
+#ifndef SQLITE_OMIT_WAL
   winShm *pShm;           /* Instance of shared memory on this file */
+#endif
   const char *zPath;      /* Full pathname of this file */
   int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */
 #if SQLITE_OS_WINCE
-  WCHAR *zDeleteOnClose;  /* Name of file to delete when closing */
-  HANDLE hMutex;          /* Mutex used to control access to shared lock */  
+  LPWSTR zDeleteOnClose;  /* Name of file to delete when closing */
+  HANDLE hMutex;          /* Mutex used to control access to shared lock */
   HANDLE hShared;         /* Shared memory segment used for locking */
   winceLock local;        /* Locks obtained by this instance of winFile */
   winceLock *shared;      /* Global shared lock memory for the file  */
 #endif
+#if SQLITE_MAX_MMAP_SIZE>0
+  int nFetchOut;                /* Number of outstanding xFetch references */
+  HANDLE hMap;                  /* Handle for accessing memory mapping */
+  void *pMapRegion;             /* Area memory mapped */
+  sqlite3_int64 mmapSize;       /* Usable size of mapped region */
+  sqlite3_int64 mmapSizeActual; /* Actual size of mapped region */
+  sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
+#endif
 };
 
 /*
+** The winVfsAppData structure is used for the pAppData member for all of the
+** Win32 VFS variants.
+*/
+typedef struct winVfsAppData winVfsAppData;
+struct winVfsAppData {
+  const sqlite3_io_methods *pMethod; /* The file I/O methods to use. */
+  void *pAppData;                    /* The extra pAppData, if any. */
+  BOOL bNoLock;                      /* Non-zero if locking is disabled. */
+};
+
+/*
+** Allowed values for winFile.ctrlFlags
+*/
+#define WINFILE_RDONLY          0x02   /* Connection is read only */
+#define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
+#define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
+
+/*
+ * The size of the buffer used by sqlite3_win32_write_debug().
+ */
+#ifndef SQLITE_WIN32_DBG_BUF_SIZE
+#  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))
+#endif
+
+/*
+ * The value used with sqlite3_win32_set_directory() to specify that
+ * the data directory should be changed.
+ */
+#ifndef SQLITE_WIN32_DATA_DIRECTORY_TYPE
+#  define SQLITE_WIN32_DATA_DIRECTORY_TYPE (1)
+#endif
+
+/*
+ * The value used with sqlite3_win32_set_directory() to specify that
+ * the temporary directory should be changed.
+ */
+#ifndef SQLITE_WIN32_TEMP_DIRECTORY_TYPE
+#  define SQLITE_WIN32_TEMP_DIRECTORY_TYPE (2)
+#endif
+
+/*
  * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
  * various Win32 API heap functions instead of our own.
  */
 #ifdef SQLITE_WIN32_MALLOC
+
+/*
+ * If this is non-zero, an isolated heap will be created by the native Win32
+ * allocator subsystem; otherwise, the default process heap will be used.  This
+ * setting has no effect when compiling for WinRT.  By default, this is enabled
+ * and an isolated heap will be created to store all allocated data.
+ *
+ ******************************************************************************
+ * WARNING: It is important to note that when this setting is non-zero and the
+ *          winMemShutdown function is called (e.g. by the sqlite3_shutdown
+ *          function), all data that was allocated using the isolated heap will
+ *          be freed immediately and any attempt to access any of that freed
+ *          data will almost certainly result in an immediate access violation.
+ ******************************************************************************
+ */
+#ifndef SQLITE_WIN32_HEAP_CREATE
+#  define SQLITE_WIN32_HEAP_CREATE    (TRUE)
+#endif
+
+/*
+ * This is cache size used in the calculation of the initial size of the
+ * Win32-specific heap.  It cannot be negative.
+ */
+#ifndef SQLITE_WIN32_CACHE_SIZE
+#  if SQLITE_DEFAULT_CACHE_SIZE>=0
+#    define SQLITE_WIN32_CACHE_SIZE (SQLITE_DEFAULT_CACHE_SIZE)
+#  else
+#    define SQLITE_WIN32_CACHE_SIZE (-(SQLITE_DEFAULT_CACHE_SIZE))
+#  endif
+#endif
+
 /*
  * The initial size of the Win32-specific heap.  This value may be zero.
  */
 #ifndef SQLITE_WIN32_HEAP_INIT_SIZE
-#  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_DEFAULT_CACHE_SIZE) * \
+#  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_WIN32_CACHE_SIZE) * \
                                        (SQLITE_DEFAULT_PAGE_SIZE) + 4194304)
 #endif
 
@@ -31735,6 +37506,7 @@ struct winFile {
 #  define SQLITE_WIN32_HEAP_FLAGS     (0)
 #endif
 
+
 /*
 ** The winMemData structure stores information required by the Win32-specific
 ** sqlite3_mem_methods implementation.
@@ -31742,30 +37514,41 @@ struct winFile {
 typedef struct winMemData winMemData;
 struct winMemData {
 #ifndef NDEBUG
-  u32 magic;    /* Magic number to detect structure corruption. */
+  u32 magic1;   /* Magic number to detect structure corruption. */
 #endif
   HANDLE hHeap; /* The handle to our heap. */
   BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
+#ifndef NDEBUG
+  u32 magic2;   /* Magic number to detect structure corruption. */
+#endif
 };
 
 #ifndef NDEBUG
-#define WINMEM_MAGIC     0x42b2830b
+#define WINMEM_MAGIC1     0x42b2830b
+#define WINMEM_MAGIC2     0xbd4d7cf4
 #endif
 
 static struct winMemData win_mem_data = {
 #ifndef NDEBUG
-  WINMEM_MAGIC,
+  WINMEM_MAGIC1,
 #endif
   NULL, FALSE
+#ifndef NDEBUG
+  ,WINMEM_MAGIC2
+#endif
 };
 
 #ifndef NDEBUG
-#define winMemAssertMagic() assert( win_mem_data.magic==WINMEM_MAGIC )
+#define winMemAssertMagic1() assert( win_mem_data.magic1==WINMEM_MAGIC1 )
+#define winMemAssertMagic2() assert( win_mem_data.magic2==WINMEM_MAGIC2 )
+#define winMemAssertMagic()  winMemAssertMagic1(); winMemAssertMagic2();
 #else
 #define winMemAssertMagic()
 #endif
 
-#define winMemGetHeap() win_mem_data.hHeap
+#define winMemGetDataPtr()  &win_mem_data
+#define winMemGetHeap()     win_mem_data.hHeap
+#define winMemGetOwned()    win_mem_data.bOwned
 
 static void *winMemMalloc(int nBytes);
 static void winMemFree(void *pPrior);
@@ -31779,29 +37562,939 @@ SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetWin32(void);
 #endif /* SQLITE_WIN32_MALLOC */
 
 /*
-** Forward prototypes.
-*/
-static int getSectorSize(
-    sqlite3_vfs *pVfs,
-    const char *zRelative     /* UTF-8 file name */
-);
-
-/*
 ** The following variable is (normally) set once and never changes
-** thereafter.  It records whether the operating system is Win95
+** thereafter.  It records whether the operating system is Win9x
 ** or WinNT.
 **
 ** 0:   Operating system unknown.
-** 1:   Operating system is Win95.
+** 1:   Operating system is Win9x.
 ** 2:   Operating system is WinNT.
 **
 ** In order to facilitate testing on a WinNT system, the test fixture
 ** can manually set this value to 1 to emulate Win98 behavior.
 */
 #ifdef SQLITE_TEST
-SQLITE_API int sqlite3_os_type = 0;
+SQLITE_API LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
+#else
+static LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
+#endif
+
+#ifndef SYSCALL
+#  define SYSCALL sqlite3_syscall_ptr
+#endif
+
+/*
+** This function is not available on Windows CE or WinRT.
+ */
+
+#if SQLITE_OS_WINCE || SQLITE_OS_WINRT
+#  define osAreFileApisANSI()       1
+#endif
+
+/*
+** Many system calls are accessed through pointer-to-functions so that
+** they may be overridden at runtime to facilitate fault injection during
+** testing and sandboxing.  The following array holds the names and pointers
+** to all overrideable system calls.
+*/
+static struct win_syscall {
+  const char *zName;            /* Name of the system call */
+  sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
+  sqlite3_syscall_ptr pDefault; /* Default value */
+} aSyscall[] = {
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
+  { "AreFileApisANSI",         (SYSCALL)AreFileApisANSI,         0 },
+#else
+  { "AreFileApisANSI",         (SYSCALL)0,                       0 },
+#endif
+
+#ifndef osAreFileApisANSI
+#define osAreFileApisANSI ((BOOL(WINAPI*)(VOID))aSyscall[0].pCurrent)
+#endif
+
+#if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
+  { "CharLowerW",              (SYSCALL)CharLowerW,              0 },
+#else
+  { "CharLowerW",              (SYSCALL)0,                       0 },
+#endif
+
+#define osCharLowerW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[1].pCurrent)
+
+#if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
+  { "CharUpperW",              (SYSCALL)CharUpperW,              0 },
+#else
+  { "CharUpperW",              (SYSCALL)0,                       0 },
+#endif
+
+#define osCharUpperW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[2].pCurrent)
+
+  { "CloseHandle",             (SYSCALL)CloseHandle,             0 },
+
+#define osCloseHandle ((BOOL(WINAPI*)(HANDLE))aSyscall[3].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "CreateFileA",             (SYSCALL)CreateFileA,             0 },
+#else
+  { "CreateFileA",             (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateFileA ((HANDLE(WINAPI*)(LPCSTR,DWORD,DWORD, \
+        LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[4].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "CreateFileW",             (SYSCALL)CreateFileW,             0 },
+#else
+  { "CreateFileW",             (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
+        LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
+        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0) && \
+        SQLITE_WIN32_CREATEFILEMAPPINGA
+  { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
+#else
+  { "CreateFileMappingA",      (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
+        DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)
+
+#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
+        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
+  { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
+#else
+  { "CreateFileMappingW",      (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
+        DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "CreateMutexW",            (SYSCALL)CreateMutexW,            0 },
+#else
+  { "CreateMutexW",            (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateMutexW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,BOOL, \
+        LPCWSTR))aSyscall[8].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "DeleteFileA",             (SYSCALL)DeleteFileA,             0 },
+#else
+  { "DeleteFileA",             (SYSCALL)0,                       0 },
+#endif
+
+#define osDeleteFileA ((BOOL(WINAPI*)(LPCSTR))aSyscall[9].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  { "DeleteFileW",             (SYSCALL)DeleteFileW,             0 },
+#else
+  { "DeleteFileW",             (SYSCALL)0,                       0 },
+#endif
+
+#define osDeleteFileW ((BOOL(WINAPI*)(LPCWSTR))aSyscall[10].pCurrent)
+
+#if SQLITE_OS_WINCE
+  { "FileTimeToLocalFileTime", (SYSCALL)FileTimeToLocalFileTime, 0 },
+#else
+  { "FileTimeToLocalFileTime", (SYSCALL)0,                       0 },
+#endif
+
+#define osFileTimeToLocalFileTime ((BOOL(WINAPI*)(CONST FILETIME*, \
+        LPFILETIME))aSyscall[11].pCurrent)
+
+#if SQLITE_OS_WINCE
+  { "FileTimeToSystemTime",    (SYSCALL)FileTimeToSystemTime,    0 },
+#else
+  { "FileTimeToSystemTime",    (SYSCALL)0,                       0 },
+#endif
+
+#define osFileTimeToSystemTime ((BOOL(WINAPI*)(CONST FILETIME*, \
+        LPSYSTEMTIME))aSyscall[12].pCurrent)
+
+  { "FlushFileBuffers",        (SYSCALL)FlushFileBuffers,        0 },
+
+#define osFlushFileBuffers ((BOOL(WINAPI*)(HANDLE))aSyscall[13].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "FormatMessageA",          (SYSCALL)FormatMessageA,          0 },
+#else
+  { "FormatMessageA",          (SYSCALL)0,                       0 },
+#endif
+
+#define osFormatMessageA ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPSTR, \
+        DWORD,va_list*))aSyscall[14].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  { "FormatMessageW",          (SYSCALL)FormatMessageW,          0 },
+#else
+  { "FormatMessageW",          (SYSCALL)0,                       0 },
+#endif
+
+#define osFormatMessageW ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPWSTR, \
+        DWORD,va_list*))aSyscall[15].pCurrent)
+
+#if !defined(SQLITE_OMIT_LOAD_EXTENSION)
+  { "FreeLibrary",             (SYSCALL)FreeLibrary,             0 },
+#else
+  { "FreeLibrary",             (SYSCALL)0,                       0 },
+#endif
+
+#define osFreeLibrary ((BOOL(WINAPI*)(HMODULE))aSyscall[16].pCurrent)
+
+  { "GetCurrentProcessId",     (SYSCALL)GetCurrentProcessId,     0 },
+
+#define osGetCurrentProcessId ((DWORD(WINAPI*)(VOID))aSyscall[17].pCurrent)
+
+#if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
+  { "GetDiskFreeSpaceA",       (SYSCALL)GetDiskFreeSpaceA,       0 },
+#else
+  { "GetDiskFreeSpaceA",       (SYSCALL)0,                       0 },
+#endif
+
+#define osGetDiskFreeSpaceA ((BOOL(WINAPI*)(LPCSTR,LPDWORD,LPDWORD,LPDWORD, \
+        LPDWORD))aSyscall[18].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "GetDiskFreeSpaceW",       (SYSCALL)GetDiskFreeSpaceW,       0 },
+#else
+  { "GetDiskFreeSpaceW",       (SYSCALL)0,                       0 },
+#endif
+
+#define osGetDiskFreeSpaceW ((BOOL(WINAPI*)(LPCWSTR,LPDWORD,LPDWORD,LPDWORD, \
+        LPDWORD))aSyscall[19].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "GetFileAttributesA",      (SYSCALL)GetFileAttributesA,      0 },
+#else
+  { "GetFileAttributesA",      (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFileAttributesA ((DWORD(WINAPI*)(LPCSTR))aSyscall[20].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "GetFileAttributesW",      (SYSCALL)GetFileAttributesW,      0 },
+#else
+  { "GetFileAttributesW",      (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFileAttributesW ((DWORD(WINAPI*)(LPCWSTR))aSyscall[21].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  { "GetFileAttributesExW",    (SYSCALL)GetFileAttributesExW,    0 },
+#else
+  { "GetFileAttributesExW",    (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFileAttributesExW ((BOOL(WINAPI*)(LPCWSTR,GET_FILEEX_INFO_LEVELS, \
+        LPVOID))aSyscall[22].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "GetFileSize",             (SYSCALL)GetFileSize,             0 },
+#else
+  { "GetFileSize",             (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFileSize ((DWORD(WINAPI*)(HANDLE,LPDWORD))aSyscall[23].pCurrent)
+
+#if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
+  { "GetFullPathNameA",        (SYSCALL)GetFullPathNameA,        0 },
+#else
+  { "GetFullPathNameA",        (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFullPathNameA ((DWORD(WINAPI*)(LPCSTR,DWORD,LPSTR, \
+        LPSTR*))aSyscall[24].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "GetFullPathNameW",        (SYSCALL)GetFullPathNameW,        0 },
+#else
+  { "GetFullPathNameW",        (SYSCALL)0,                       0 },
+#endif
+
+#define osGetFullPathNameW ((DWORD(WINAPI*)(LPCWSTR,DWORD,LPWSTR, \
+        LPWSTR*))aSyscall[25].pCurrent)
+
+  { "GetLastError",            (SYSCALL)GetLastError,            0 },
+
+#define osGetLastError ((DWORD(WINAPI*)(VOID))aSyscall[26].pCurrent)
+
+#if !defined(SQLITE_OMIT_LOAD_EXTENSION)
+#if SQLITE_OS_WINCE
+  /* The GetProcAddressA() routine is only available on Windows CE. */
+  { "GetProcAddressA",         (SYSCALL)GetProcAddressA,         0 },
+#else
+  /* All other Windows platforms expect GetProcAddress() to take
+  ** an ANSI string regardless of the _UNICODE setting */
+  { "GetProcAddressA",         (SYSCALL)GetProcAddress,          0 },
+#endif
+#else
+  { "GetProcAddressA",         (SYSCALL)0,                       0 },
+#endif
+
+#define osGetProcAddressA ((FARPROC(WINAPI*)(HMODULE, \
+        LPCSTR))aSyscall[27].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "GetSystemInfo",           (SYSCALL)GetSystemInfo,           0 },
+#else
+  { "GetSystemInfo",           (SYSCALL)0,                       0 },
+#endif
+
+#define osGetSystemInfo ((VOID(WINAPI*)(LPSYSTEM_INFO))aSyscall[28].pCurrent)
+
+  { "GetSystemTime",           (SYSCALL)GetSystemTime,           0 },
+
+#define osGetSystemTime ((VOID(WINAPI*)(LPSYSTEMTIME))aSyscall[29].pCurrent)
+
+#if !SQLITE_OS_WINCE
+  { "GetSystemTimeAsFileTime", (SYSCALL)GetSystemTimeAsFileTime, 0 },
+#else
+  { "GetSystemTimeAsFileTime", (SYSCALL)0,                       0 },
+#endif
+
+#define osGetSystemTimeAsFileTime ((VOID(WINAPI*)( \
+        LPFILETIME))aSyscall[30].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "GetTempPathA",            (SYSCALL)GetTempPathA,            0 },
+#else
+  { "GetTempPathA",            (SYSCALL)0,                       0 },
+#endif
+
+#define osGetTempPathA ((DWORD(WINAPI*)(DWORD,LPSTR))aSyscall[31].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
+  { "GetTempPathW",            (SYSCALL)GetTempPathW,            0 },
+#else
+  { "GetTempPathW",            (SYSCALL)0,                       0 },
+#endif
+
+#define osGetTempPathW ((DWORD(WINAPI*)(DWORD,LPWSTR))aSyscall[32].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "GetTickCount",            (SYSCALL)GetTickCount,            0 },
+#else
+  { "GetTickCount",            (SYSCALL)0,                       0 },
+#endif
+
+#define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_GETVERSIONEX
+  { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
+#else
+  { "GetVersionExA",           (SYSCALL)0,                       0 },
+#endif
+
+#define osGetVersionExA ((BOOL(WINAPI*)( \
+        LPOSVERSIONINFOA))aSyscall[34].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
+        SQLITE_WIN32_GETVERSIONEX
+  { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
+#else
+  { "GetVersionExW",           (SYSCALL)0,                       0 },
+#endif
+
+#define osGetVersionExW ((BOOL(WINAPI*)( \
+        LPOSVERSIONINFOW))aSyscall[35].pCurrent)
+
+  { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },
+
+#define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \
+        SIZE_T))aSyscall[36].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "HeapCreate",              (SYSCALL)HeapCreate,              0 },
+#else
+  { "HeapCreate",              (SYSCALL)0,                       0 },
+#endif
+
+#define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \
+        SIZE_T))aSyscall[37].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },
+#else
+  { "HeapDestroy",             (SYSCALL)0,                       0 },
+#endif
+
+#define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)
+
+  { "HeapFree",                (SYSCALL)HeapFree,                0 },
+
+#define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)
+
+  { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },
+
+#define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \
+        SIZE_T))aSyscall[40].pCurrent)
+
+  { "HeapSize",                (SYSCALL)HeapSize,                0 },
+
+#define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \
+        LPCVOID))aSyscall[41].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "HeapValidate",            (SYSCALL)HeapValidate,            0 },
+#else
+  { "HeapValidate",            (SYSCALL)0,                       0 },
+#endif
+
+#define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \
+        LPCVOID))aSyscall[42].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
+  { "HeapCompact",             (SYSCALL)HeapCompact,             0 },
+#else
+  { "HeapCompact",             (SYSCALL)0,                       0 },
+#endif
+
+#define osHeapCompact ((UINT(WINAPI*)(HANDLE,DWORD))aSyscall[43].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
+  { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },
+#else
+  { "LoadLibraryA",            (SYSCALL)0,                       0 },
+#endif
+
+#define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[44].pCurrent)
+
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
+        !defined(SQLITE_OMIT_LOAD_EXTENSION)
+  { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },
+#else
+  { "LoadLibraryW",            (SYSCALL)0,                       0 },
+#endif
+
+#define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[45].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "LocalFree",               (SYSCALL)LocalFree,               0 },
+#else
+  { "LocalFree",               (SYSCALL)0,                       0 },
+#endif
+
+#define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[46].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
+  { "LockFile",                (SYSCALL)LockFile,                0 },
+#else
+  { "LockFile",                (SYSCALL)0,                       0 },
+#endif
+
+#ifndef osLockFile
+#define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
+        DWORD))aSyscall[47].pCurrent)
+#endif
+
+#if !SQLITE_OS_WINCE
+  { "LockFileEx",              (SYSCALL)LockFileEx,              0 },
+#else
+  { "LockFileEx",              (SYSCALL)0,                       0 },
+#endif
+
+#ifndef osLockFileEx
+#define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
+        LPOVERLAPPED))aSyscall[48].pCurrent)
+#endif
+
+#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \
+        (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
+  { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
+#else
+  { "MapViewOfFile",           (SYSCALL)0,                       0 },
+#endif
+
+#define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
+        SIZE_T))aSyscall[49].pCurrent)
+
+  { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },
+
+#define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \
+        int))aSyscall[50].pCurrent)
+
+  { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },
+
+#define osQueryPerformanceCounter ((BOOL(WINAPI*)( \
+        LARGE_INTEGER*))aSyscall[51].pCurrent)
+
+  { "ReadFile",                (SYSCALL)ReadFile,                0 },
+
+#define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \
+        LPOVERLAPPED))aSyscall[52].pCurrent)
+
+  { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },
+
+#define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[53].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },
+#else
+  { "SetFilePointer",          (SYSCALL)0,                       0 },
+#endif
+
+#define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \
+        DWORD))aSyscall[54].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "Sleep",                   (SYSCALL)Sleep,                   0 },
+#else
+  { "Sleep",                   (SYSCALL)0,                       0 },
+#endif
+
+#define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[55].pCurrent)
+
+  { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },
+
+#define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \
+        LPFILETIME))aSyscall[56].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
+  { "UnlockFile",              (SYSCALL)UnlockFile,              0 },
+#else
+  { "UnlockFile",              (SYSCALL)0,                       0 },
+#endif
+
+#ifndef osUnlockFile
+#define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
+        DWORD))aSyscall[57].pCurrent)
+#endif
+
+#if !SQLITE_OS_WINCE
+  { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },
+#else
+  { "UnlockFileEx",            (SYSCALL)0,                       0 },
+#endif
+
+#define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
+        LPOVERLAPPED))aSyscall[58].pCurrent)
+
+#if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
+  { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
+#else
+  { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
+#endif
+
+#define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)
+
+  { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },
+
+#define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \
+        LPCSTR,LPBOOL))aSyscall[60].pCurrent)
+
+  { "WriteFile",               (SYSCALL)WriteFile,               0 },
+
+#define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \
+        LPOVERLAPPED))aSyscall[61].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },
+#else
+  { "CreateEventExW",          (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \
+        DWORD,DWORD))aSyscall[62].pCurrent)
+
+#if !SQLITE_OS_WINRT
+  { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },
+#else
+  { "WaitForSingleObject",     (SYSCALL)0,                       0 },
+#endif
+
+#define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \
+        DWORD))aSyscall[63].pCurrent)
+
+#if !SQLITE_OS_WINCE
+  { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },
+#else
+  { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },
+#endif
+
+#define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \
+        BOOL))aSyscall[64].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },
+#else
+  { "SetFilePointerEx",        (SYSCALL)0,                       0 },
+#endif
+
+#define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \
+        PLARGE_INTEGER,DWORD))aSyscall[65].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },
+#else
+  { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
+#endif
+
+#define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
+        FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)
+
+#if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
+  { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
+#else
+  { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
+#endif
+
+#define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
+        SIZE_T))aSyscall[67].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "CreateFile2",             (SYSCALL)CreateFile2,             0 },
+#else
+  { "CreateFile2",             (SYSCALL)0,                       0 },
+#endif
+
+#define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \
+        LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[68].pCurrent)
+
+#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)
+  { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },
+#else
+  { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },
+#endif
+
+#define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \
+        DWORD))aSyscall[69].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },
+#else
+  { "GetTickCount64",          (SYSCALL)0,                       0 },
+#endif
+
+#define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[70].pCurrent)
+
+#if SQLITE_OS_WINRT
+  { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },
+#else
+  { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },
+#endif
+
+#define osGetNativeSystemInfo ((VOID(WINAPI*)( \
+        LPSYSTEM_INFO))aSyscall[71].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },
+#else
+  { "OutputDebugStringA",      (SYSCALL)0,                       0 },
+#endif
+
+#define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[72].pCurrent)
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },
+#else
+  { "OutputDebugStringW",      (SYSCALL)0,                       0 },
+#endif
+
+#define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)
+
+  { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },
+
+#define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)
+
+#if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
+  { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
+#else
+  { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
+#endif
+
+#define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
+        LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)
+
+/*
+** NOTE: On some sub-platforms, the InterlockedCompareExchange "function"
+**       is really just a macro that uses a compiler intrinsic (e.g. x64).
+**       So do not try to make this is into a redefinable interface.
+*/
+#if defined(InterlockedCompareExchange)
+  { "InterlockedCompareExchange", (SYSCALL)0,                    0 },
+
+#define osInterlockedCompareExchange InterlockedCompareExchange
+#else
+  { "InterlockedCompareExchange", (SYSCALL)InterlockedCompareExchange, 0 },
+
+#define osInterlockedCompareExchange ((LONG(WINAPI*)(LONG \
+        SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)
+#endif /* defined(InterlockedCompareExchange) */
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  { "UuidCreate",               (SYSCALL)UuidCreate,             0 },
+#else
+  { "UuidCreate",               (SYSCALL)0,                      0 },
+#endif
+
+#define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)
+
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },
+#else
+  { "UuidCreateSequential",     (SYSCALL)0,                      0 },
+#endif
+
+#define osUuidCreateSequential \
+        ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)
+
+#if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0
+  { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },
+#else
+  { "FlushViewOfFile",          (SYSCALL)0,                      0 },
+#endif
+
+#define osFlushViewOfFile \
+        ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)
+
+}; /* End of the overrideable system calls */
+
+/*
+** This is the xSetSystemCall() method of sqlite3_vfs for all of the
+** "win32" VFSes.  Return SQLITE_OK opon successfully updating the
+** system call pointer, or SQLITE_NOTFOUND if there is no configurable
+** system call named zName.
+*/
+static int winSetSystemCall(
+  sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */
+  const char *zName,            /* Name of system call to override */
+  sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */
+){
+  unsigned int i;
+  int rc = SQLITE_NOTFOUND;
+
+  UNUSED_PARAMETER(pNotUsed);
+  if( zName==0 ){
+    /* If no zName is given, restore all system calls to their default
+    ** settings and return NULL
+    */
+    rc = SQLITE_OK;
+    for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
+      if( aSyscall[i].pDefault ){
+        aSyscall[i].pCurrent = aSyscall[i].pDefault;
+      }
+    }
+  }else{
+    /* If zName is specified, operate on only the one system call
+    ** specified.
+    */
+    for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
+      if( strcmp(zName, aSyscall[i].zName)==0 ){
+        if( aSyscall[i].pDefault==0 ){
+          aSyscall[i].pDefault = aSyscall[i].pCurrent;
+        }
+        rc = SQLITE_OK;
+        if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;
+        aSyscall[i].pCurrent = pNewFunc;
+        break;
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** Return the value of a system call.  Return NULL if zName is not a
+** recognized system call name.  NULL is also returned if the system call
+** is currently undefined.
+*/
+static sqlite3_syscall_ptr winGetSystemCall(
+  sqlite3_vfs *pNotUsed,
+  const char *zName
+){
+  unsigned int i;
+
+  UNUSED_PARAMETER(pNotUsed);
+  for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
+    if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;
+  }
+  return 0;
+}
+
+/*
+** Return the name of the first system call after zName.  If zName==NULL
+** then return the name of the first system call.  Return NULL if zName
+** is the last system call or if zName is not the name of a valid
+** system call.
+*/
+static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){
+  int i = -1;
+
+  UNUSED_PARAMETER(p);
+  if( zName ){
+    for(i=0; i<ArraySize(aSyscall)-1; i++){
+      if( strcmp(zName, aSyscall[i].zName)==0 ) break;
+    }
+  }
+  for(i++; i<ArraySize(aSyscall); i++){
+    if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
+  }
+  return 0;
+}
+
+#ifdef SQLITE_WIN32_MALLOC
+/*
+** If a Win32 native heap has been configured, this function will attempt to
+** compact it.  Upon success, SQLITE_OK will be returned.  Upon failure, one
+** of SQLITE_NOMEM, SQLITE_ERROR, or SQLITE_NOTFOUND will be returned.  The
+** "pnLargest" argument, if non-zero, will be used to return the size of the
+** largest committed free block in the heap, in bytes.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_win32_compact_heap(LPUINT pnLargest){
+  int rc = SQLITE_OK;
+  UINT nLargest = 0;
+  HANDLE hHeap;
+
+  winMemAssertMagic();
+  hHeap = winMemGetHeap();
+  assert( hHeap!=0 );
+  assert( hHeap!=INVALID_HANDLE_VALUE );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#endif
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
+  if( (nLargest=osHeapCompact(hHeap, SQLITE_WIN32_HEAP_FLAGS))==0 ){
+    DWORD lastErrno = osGetLastError();
+    if( lastErrno==NO_ERROR ){
+      sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",
+                  (void*)hHeap);
+      rc = SQLITE_NOMEM_BKPT;
+    }else{
+      sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",
+                  osGetLastError(), (void*)hHeap);
+      rc = SQLITE_ERROR;
+    }
+  }
+#else
+  sqlite3_log(SQLITE_NOTFOUND, "failed to HeapCompact, heap=%p",
+              (void*)hHeap);
+  rc = SQLITE_NOTFOUND;
+#endif
+  if( pnLargest ) *pnLargest = nLargest;
+  return rc;
+}
+
+/*
+** If a Win32 native heap has been configured, this function will attempt to
+** destroy and recreate it.  If the Win32 native heap is not isolated and/or
+** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will
+** be returned and no changes will be made to the Win32 native heap.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_win32_reset_heap(){
+  int rc;
+  MUTEX_LOGIC( sqlite3_mutex *pMaster; ) /* The main static mutex */
+  MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
+  MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
+  MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )
+  sqlite3_mutex_enter(pMaster);
+  sqlite3_mutex_enter(pMem);
+  winMemAssertMagic();
+  if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){
+    /*
+    ** At this point, there should be no outstanding memory allocations on
+    ** the heap.  Also, since both the master and memsys locks are currently
+    ** being held by us, no other function (i.e. from another thread) should
+    ** be able to even access the heap.  Attempt to destroy and recreate our
+    ** isolated Win32 native heap now.
+    */
+    assert( winMemGetHeap()!=NULL );
+    assert( winMemGetOwned() );
+    assert( sqlite3_memory_used()==0 );
+    winMemShutdown(winMemGetDataPtr());
+    assert( winMemGetHeap()==NULL );
+    assert( !winMemGetOwned() );
+    assert( sqlite3_memory_used()==0 );
+    rc = winMemInit(winMemGetDataPtr());
+    assert( rc!=SQLITE_OK || winMemGetHeap()!=NULL );
+    assert( rc!=SQLITE_OK || winMemGetOwned() );
+    assert( rc!=SQLITE_OK || sqlite3_memory_used()==0 );
+  }else{
+    /*
+    ** The Win32 native heap cannot be modified because it may be in use.
+    */
+    rc = SQLITE_BUSY;
+  }
+  sqlite3_mutex_leave(pMem);
+  sqlite3_mutex_leave(pMaster);
+  return rc;
+}
+#endif /* SQLITE_WIN32_MALLOC */
+
+/*
+** This function outputs the specified (ANSI) string to the Win32 debugger
+** (if available).
+*/
+
+SQLITE_API void SQLITE_STDCALL sqlite3_win32_write_debug(const char *zBuf, int nBuf){
+  char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];
+  int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
+  if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
+  assert( nMin==-1 || nMin==0 || nMin<SQLITE_WIN32_DBG_BUF_SIZE );
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zBuf ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+#if defined(SQLITE_WIN32_HAS_ANSI)
+  if( nMin>0 ){
+    memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
+    memcpy(zDbgBuf, zBuf, nMin);
+    osOutputDebugStringA(zDbgBuf);
+  }else{
+    osOutputDebugStringA(zBuf);
+  }
+#elif defined(SQLITE_WIN32_HAS_WIDE)
+  memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
+  if ( osMultiByteToWideChar(
+          osAreFileApisANSI() ? CP_ACP : CP_OEMCP, 0, zBuf,
+          nMin, (LPWSTR)zDbgBuf, SQLITE_WIN32_DBG_BUF_SIZE/sizeof(WCHAR))<=0 ){
+    return;
+  }
+  osOutputDebugStringW((LPCWSTR)zDbgBuf);
+#else
+  if( nMin>0 ){
+    memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
+    memcpy(zDbgBuf, zBuf, nMin);
+    fprintf(stderr, "%s", zDbgBuf);
+  }else{
+    fprintf(stderr, "%s", zBuf);
+  }
+#endif
+}
+
+/*
+** The following routine suspends the current thread for at least ms
+** milliseconds.  This is equivalent to the Win32 Sleep() interface.
+*/
+#if SQLITE_OS_WINRT
+static HANDLE sleepObj = NULL;
+#endif
+
+SQLITE_API void SQLITE_STDCALL sqlite3_win32_sleep(DWORD milliseconds){
+#if SQLITE_OS_WINRT
+  if ( sleepObj==NULL ){
+    sleepObj = osCreateEventExW(NULL, NULL, CREATE_EVENT_MANUAL_RESET,
+                                SYNCHRONIZE);
+  }
+  assert( sleepObj!=NULL );
+  osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);
 #else
-static int sqlite3_os_type = 0;
+  osSleep(milliseconds);
+#endif
+}
+
+#if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
+        SQLITE_THREADSAFE>0
+SQLITE_PRIVATE DWORD sqlite3Win32Wait(HANDLE hObject){
+  DWORD rc;
+  while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,
+                                       TRUE))==WAIT_IO_COMPLETION ){}
+  return rc;
+}
 #endif
 
 /*
@@ -31815,19 +38508,55 @@ static int sqlite3_os_type = 0;
 ** WinNT/2K/XP so that we will know whether or not we can safely call
 ** the LockFileEx() API.
 */
-#if SQLITE_OS_WINCE
-# define isNT()  (1)
+
+#if !SQLITE_WIN32_GETVERSIONEX
+# define osIsNT()  (1)
+#elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
+# define osIsNT()  (1)
+#elif !defined(SQLITE_WIN32_HAS_WIDE)
+# define osIsNT()  (0)
 #else
-  static int isNT(void){
-    if( sqlite3_os_type==0 ){
-      OSVERSIONINFO sInfo;
-      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
-      GetVersionEx(&sInfo);
-      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
-    }
-    return sqlite3_os_type==2;
-  }
-#endif /* SQLITE_OS_WINCE */
+# define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())
+#endif
+
+/*
+** This function determines if the machine is running a version of Windows
+** based on the NT kernel.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_win32_is_nt(void){
+#if SQLITE_OS_WINRT
+  /*
+  ** NOTE: The WinRT sub-platform is always assumed to be based on the NT
+  **       kernel.
+  */
+  return 1;
+#elif SQLITE_WIN32_GETVERSIONEX
+  if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
+#if defined(SQLITE_WIN32_HAS_ANSI)
+    OSVERSIONINFOA sInfo;
+    sInfo.dwOSVersionInfoSize = sizeof(sInfo);
+    osGetVersionExA(&sInfo);
+    osInterlockedCompareExchange(&sqlite3_os_type,
+        (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
+#elif defined(SQLITE_WIN32_HAS_WIDE)
+    OSVERSIONINFOW sInfo;
+    sInfo.dwOSVersionInfoSize = sizeof(sInfo);
+    osGetVersionExW(&sInfo);
+    osInterlockedCompareExchange(&sqlite3_os_type,
+        (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
+#endif
+  }
+  return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
+#elif SQLITE_TEST
+  return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
+#else
+  /*
+  ** NOTE: All sub-platforms where the GetVersionEx[AW] functions are
+  **       deprecated are always assumed to be based on the NT kernel.
+  */
+  return 1;
+#endif
+}
 
 #ifdef SQLITE_WIN32_MALLOC
 /*
@@ -31841,14 +38570,14 @@ static void *winMemMalloc(int nBytes){
   hHeap = winMemGetHeap();
   assert( hHeap!=0 );
   assert( hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
 #endif
   assert( nBytes>=0 );
-  p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
+  p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
   if( !p ){
-    sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%d), heap=%p",
-        nBytes, GetLastError(), (void*)hHeap);
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",
+                nBytes, osGetLastError(), (void*)hHeap);
   }
   return p;
 }
@@ -31863,13 +38592,13 @@ static void winMemFree(void *pPrior){
   hHeap = winMemGetHeap();
   assert( hHeap!=0 );
   assert( hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
 #endif
   if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
-  if( !HeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
-    sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%d), heap=%p",
-        pPrior, GetLastError(), (void*)hHeap);
+  if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",
+                pPrior, osGetLastError(), (void*)hHeap);
   }
 }
 
@@ -31884,19 +38613,19 @@ static void *winMemRealloc(void *pPrior, int nBytes){
   hHeap = winMemGetHeap();
   assert( hHeap!=0 );
   assert( hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
 #endif
   assert( nBytes>=0 );
   if( !pPrior ){
-    p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
+    p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
   }else{
-    p = HeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
+    p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
   }
   if( !p ){
-    sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%d), heap=%p",
-        pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, GetLastError(),
-        (void*)hHeap);
+    sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",
+                pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),
+                (void*)hHeap);
   }
   return p;
 }
@@ -31912,14 +38641,14 @@ static int winMemSize(void *p){
   hHeap = winMemGetHeap();
   assert( hHeap!=0 );
   assert( hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, p) );
 #endif
   if( !p ) return 0;
-  n = HeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
+  n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
   if( n==(SIZE_T)-1 ){
-    sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%d), heap=%p",
-        p, GetLastError(), (void*)hHeap);
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",
+                p, osGetLastError(), (void*)hHeap);
     return 0;
   }
   return (int)n;
@@ -31939,24 +38668,44 @@ static int winMemInit(void *pAppData){
   winMemData *pWinMemData = (winMemData *)pAppData;
 
   if( !pWinMemData ) return SQLITE_ERROR;
-  assert( pWinMemData->magic==WINMEM_MAGIC );
+  assert( pWinMemData->magic1==WINMEM_MAGIC1 );
+  assert( pWinMemData->magic2==WINMEM_MAGIC2 );
+
+#if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE
   if( !pWinMemData->hHeap ){
-    pWinMemData->hHeap = HeapCreate(SQLITE_WIN32_HEAP_FLAGS,
-                                    SQLITE_WIN32_HEAP_INIT_SIZE,
-                                    SQLITE_WIN32_HEAP_MAX_SIZE);
+    DWORD dwInitialSize = SQLITE_WIN32_HEAP_INIT_SIZE;
+    DWORD dwMaximumSize = (DWORD)sqlite3GlobalConfig.nHeap;
+    if( dwMaximumSize==0 ){
+      dwMaximumSize = SQLITE_WIN32_HEAP_MAX_SIZE;
+    }else if( dwInitialSize>dwMaximumSize ){
+      dwInitialSize = dwMaximumSize;
+    }
+    pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,
+                                      dwInitialSize, dwMaximumSize);
     if( !pWinMemData->hHeap ){
       sqlite3_log(SQLITE_NOMEM,
-          "failed to HeapCreate (%d), flags=%u, initSize=%u, maxSize=%u",
-          GetLastError(), SQLITE_WIN32_HEAP_FLAGS, SQLITE_WIN32_HEAP_INIT_SIZE,
-          SQLITE_WIN32_HEAP_MAX_SIZE);
-      return SQLITE_NOMEM;
+          "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",
+          osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,
+          dwMaximumSize);
+      return SQLITE_NOMEM_BKPT;
     }
     pWinMemData->bOwned = TRUE;
+    assert( pWinMemData->bOwned );
+  }
+#else
+  pWinMemData->hHeap = osGetProcessHeap();
+  if( !pWinMemData->hHeap ){
+    sqlite3_log(SQLITE_NOMEM,
+        "failed to GetProcessHeap (%lu)", osGetLastError());
+    return SQLITE_NOMEM_BKPT;
   }
+  pWinMemData->bOwned = FALSE;
+  assert( !pWinMemData->bOwned );
+#endif
   assert( pWinMemData->hHeap!=0 );
   assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-  assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+  assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
 #endif
   return SQLITE_OK;
 }
@@ -31968,15 +38717,18 @@ static void winMemShutdown(void *pAppData){
   winMemData *pWinMemData = (winMemData *)pAppData;
 
   if( !pWinMemData ) return;
+  assert( pWinMemData->magic1==WINMEM_MAGIC1 );
+  assert( pWinMemData->magic2==WINMEM_MAGIC2 );
+
   if( pWinMemData->hHeap ){
     assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
-#ifdef SQLITE_WIN32_MALLOC_VALIDATE
-    assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
+    assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
 #endif
     if( pWinMemData->bOwned ){
-      if( !HeapDestroy(pWinMemData->hHeap) ){
-        sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%d), heap=%p",
-            GetLastError(), (void*)pWinMemData->hHeap);
+      if( !osHeapDestroy(pWinMemData->hHeap) ){
+        sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",
+                    osGetLastError(), (void*)pWinMemData->hHeap);
       }
       pWinMemData->bOwned = FALSE;
     }
@@ -32012,193 +38764,359 @@ SQLITE_PRIVATE void sqlite3MemSetDefault(void){
 #endif /* SQLITE_WIN32_MALLOC */
 
 /*
-** Convert a UTF-8 string to microsoft unicode (UTF-16?). 
+** Convert a UTF-8 string to Microsoft Unicode.
 **
-** Space to hold the returned string is obtained from malloc.
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static WCHAR *utf8ToUnicode(const char *zFilename){
+static LPWSTR winUtf8ToUnicode(const char *zText){
   int nChar;
-  WCHAR *zWideFilename;
+  LPWSTR zWideText;
 
-  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
-  zWideFilename = malloc( nChar*sizeof(zWideFilename[0]) );
-  if( zWideFilename==0 ){
+  nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, NULL, 0);
+  if( nChar==0 ){
     return 0;
   }
-  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename, nChar);
+  zWideText = sqlite3MallocZero( nChar*sizeof(WCHAR) );
+  if( zWideText==0 ){
+    return 0;
+  }
+  nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, zWideText,
+                                nChar);
   if( nChar==0 ){
-    free(zWideFilename);
-    zWideFilename = 0;
+    sqlite3_free(zWideText);
+    zWideText = 0;
   }
-  return zWideFilename;
+  return zWideText;
 }
 
 /*
-** Convert microsoft unicode to UTF-8.  Space to hold the returned string is
-** obtained from malloc().
+** Convert a Microsoft Unicode string to UTF-8.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static char *unicodeToUtf8(const WCHAR *zWideFilename){
+static char *winUnicodeToUtf8(LPCWSTR zWideText){
   int nByte;
-  char *zFilename;
+  char *zText;
 
-  nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
-  zFilename = malloc( nByte );
-  if( zFilename==0 ){
+  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, 0, 0, 0, 0);
+  if( nByte == 0 ){
     return 0;
   }
-  nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
-                              0, 0);
+  zText = sqlite3MallocZero( nByte );
+  if( zText==0 ){
+    return 0;
+  }
+  nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, zText, nByte,
+                                0, 0);
   if( nByte == 0 ){
-    free(zFilename);
-    zFilename = 0;
+    sqlite3_free(zText);
+    zText = 0;
   }
-  return zFilename;
+  return zText;
 }
 
 /*
-** Convert an ansi string to microsoft unicode, based on the
-** current codepage settings for file apis.
-** 
-** Space to hold the returned string is obtained
-** from malloc.
+** Convert an ANSI string to Microsoft Unicode, using the ANSI or OEM
+** code page.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static WCHAR *mbcsToUnicode(const char *zFilename){
+static LPWSTR winMbcsToUnicode(const char *zText, int useAnsi){
   int nByte;
-  WCHAR *zMbcsFilename;
-  int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
+  LPWSTR zMbcsText;
+  int codepage = useAnsi ? CP_ACP : CP_OEMCP;
 
-  nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, NULL,0)*sizeof(WCHAR);
-  zMbcsFilename = malloc( nByte*sizeof(zMbcsFilename[0]) );
-  if( zMbcsFilename==0 ){
+  nByte = osMultiByteToWideChar(codepage, 0, zText, -1, NULL,
+                                0)*sizeof(WCHAR);
+  if( nByte==0 ){
+    return 0;
+  }
+  zMbcsText = sqlite3MallocZero( nByte*sizeof(WCHAR) );
+  if( zMbcsText==0 ){
     return 0;
   }
-  nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, zMbcsFilename, nByte);
+  nByte = osMultiByteToWideChar(codepage, 0, zText, -1, zMbcsText,
+                                nByte);
   if( nByte==0 ){
-    free(zMbcsFilename);
-    zMbcsFilename = 0;
+    sqlite3_free(zMbcsText);
+    zMbcsText = 0;
   }
-  return zMbcsFilename;
+  return zMbcsText;
 }
 
 /*
-** Convert microsoft unicode to multibyte character string, based on the
-** user's Ansi codepage.
+** Convert a Microsoft Unicode string to a multi-byte character string,
+** using the ANSI or OEM code page.
 **
-** Space to hold the returned string is obtained from
-** malloc().
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-static char *unicodeToMbcs(const WCHAR *zWideFilename){
+static char *winUnicodeToMbcs(LPCWSTR zWideText, int useAnsi){
   int nByte;
-  char *zFilename;
-  int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
+  char *zText;
+  int codepage = useAnsi ? CP_ACP : CP_OEMCP;
 
-  nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
-  zFilename = malloc( nByte );
-  if( zFilename==0 ){
+  nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, 0, 0, 0, 0);
+  if( nByte == 0 ){
     return 0;
   }
-  nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, zFilename, nByte,
-                              0, 0);
+  zText = sqlite3MallocZero( nByte );
+  if( zText==0 ){
+    return 0;
+  }
+  nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, zText,
+                                nByte, 0, 0);
   if( nByte == 0 ){
-    free(zFilename);
-    zFilename = 0;
+    sqlite3_free(zText);
+    zText = 0;
   }
-  return zFilename;
+  return zText;
 }
 
 /*
-** Convert multibyte character string to UTF-8.  Space to hold the
-** returned string is obtained from malloc().
+** Convert a multi-byte character string to UTF-8.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-SQLITE_API char *sqlite3_win32_mbcs_to_utf8(const char *zFilename){
-  char *zFilenameUtf8;
-  WCHAR *zTmpWide;
+static char *winMbcsToUtf8(const char *zText, int useAnsi){
+  char *zTextUtf8;
+  LPWSTR zTmpWide;
 
-  zTmpWide = mbcsToUnicode(zFilename);
+  zTmpWide = winMbcsToUnicode(zText, useAnsi);
   if( zTmpWide==0 ){
     return 0;
   }
-  zFilenameUtf8 = unicodeToUtf8(zTmpWide);
-  free(zTmpWide);
-  return zFilenameUtf8;
+  zTextUtf8 = winUnicodeToUtf8(zTmpWide);
+  sqlite3_free(zTmpWide);
+  return zTextUtf8;
 }
 
 /*
-** Convert UTF-8 to multibyte character string.  Space to hold the 
-** returned string is obtained from malloc().
+** Convert a UTF-8 string to a multi-byte character string.
+**
+** Space to hold the returned string is obtained from sqlite3_malloc().
 */
-SQLITE_API char *sqlite3_win32_utf8_to_mbcs(const char *zFilename){
-  char *zFilenameMbcs;
-  WCHAR *zTmpWide;
+static char *winUtf8ToMbcs(const char *zText, int useAnsi){
+  char *zTextMbcs;
+  LPWSTR zTmpWide;
 
-  zTmpWide = utf8ToUnicode(zFilename);
+  zTmpWide = winUtf8ToUnicode(zText);
   if( zTmpWide==0 ){
     return 0;
   }
-  zFilenameMbcs = unicodeToMbcs(zTmpWide);
-  free(zTmpWide);
-  return zFilenameMbcs;
+  zTextMbcs = winUnicodeToMbcs(zTmpWide, useAnsi);
+  sqlite3_free(zTmpWide);
+  return zTextMbcs;
 }
 
+/*
+** This is a public wrapper for the winUtf8ToUnicode() function.
+*/
+SQLITE_API LPWSTR SQLITE_STDCALL sqlite3_win32_utf8_to_unicode(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToUnicode(zText);
+}
 
 /*
-** The return value of getLastErrorMsg
+** This is a public wrapper for the winUnicodeToUtf8() function.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_win32_unicode_to_utf8(LPCWSTR zWideText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zWideText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUnicodeToUtf8(zWideText);
+}
+
+/*
+** This is a public wrapper for the winMbcsToUtf8() function.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_win32_mbcs_to_utf8(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winMbcsToUtf8(zText, osAreFileApisANSI());
+}
+
+/*
+** This is a public wrapper for the winMbcsToUtf8() function.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_win32_mbcs_to_utf8_v2(const char *zText, int useAnsi){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winMbcsToUtf8(zText, useAnsi);
+}
+
+/*
+** This is a public wrapper for the winUtf8ToMbcs() function.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_win32_utf8_to_mbcs(const char *zText){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToMbcs(zText, osAreFileApisANSI());
+}
+
+/*
+** This is a public wrapper for the winUtf8ToMbcs() function.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_win32_utf8_to_mbcs_v2(const char *zText, int useAnsi){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !zText ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_AUTOINIT
+  if( sqlite3_initialize() ) return 0;
+#endif
+  return winUtf8ToMbcs(zText, useAnsi);
+}
+
+/*
+** This function sets the data directory or the temporary directory based on
+** the provided arguments.  The type argument must be 1 in order to set the
+** data directory or 2 in order to set the temporary directory.  The zValue
+** argument is the name of the directory to use.  The return value will be
+** SQLITE_OK if successful.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_win32_set_directory(DWORD type, LPCWSTR zValue){
+  char **ppDirectory = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  int rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
+    ppDirectory = &sqlite3_data_directory;
+  }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
+    ppDirectory = &sqlite3_temp_directory;
+  }
+  assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
+          || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
+  );
+  assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
+  if( ppDirectory ){
+    char *zValueUtf8 = 0;
+    if( zValue && zValue[0] ){
+      zValueUtf8 = winUnicodeToUtf8(zValue);
+      if ( zValueUtf8==0 ){
+        return SQLITE_NOMEM_BKPT;
+      }
+    }
+    sqlite3_free(*ppDirectory);
+    *ppDirectory = zValueUtf8;
+    return SQLITE_OK;
+  }
+  return SQLITE_ERROR;
+}
+
+/*
+** The return value of winGetLastErrorMsg
 ** is zero if the error message fits in the buffer, or non-zero
 ** otherwise (if the message was truncated).
 */
-static int getLastErrorMsg(int nBuf, char *zBuf){
+static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
   /* FormatMessage returns 0 on failure.  Otherwise it
   ** returns the number of TCHARs written to the output
   ** buffer, excluding the terminating null char.
   */
-  DWORD error = GetLastError();
   DWORD dwLen = 0;
   char *zOut = 0;
 
-  if( isNT() ){
-    WCHAR *zTempWide = NULL;
-    dwLen = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
-                           NULL,
-                           error,
-                           0,
-                           (LPWSTR) &zTempWide,
-                           0,
-                           0);
+  if( osIsNT() ){
+#if SQLITE_OS_WINRT
+    WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
+    dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
+                             FORMAT_MESSAGE_IGNORE_INSERTS,
+                             NULL,
+                             lastErrno,
+                             0,
+                             zTempWide,
+                             SQLITE_WIN32_MAX_ERRMSG_CHARS,
+                             0);
+#else
+    LPWSTR zTempWide = NULL;
+    dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                             FORMAT_MESSAGE_FROM_SYSTEM |
+                             FORMAT_MESSAGE_IGNORE_INSERTS,
+                             NULL,
+                             lastErrno,
+                             0,
+                             (LPWSTR) &zTempWide,
+                             0,
+                             0);
+#endif
     if( dwLen > 0 ){
       /* allocate a buffer and convert to UTF8 */
-      zOut = unicodeToUtf8(zTempWide);
+      sqlite3BeginBenignMalloc();
+      zOut = winUnicodeToUtf8(zTempWide);
+      sqlite3EndBenignMalloc();
+#if !SQLITE_OS_WINRT
       /* free the system buffer allocated by FormatMessage */
-      LocalFree(zTempWide);
+      osLocalFree(zTempWide);
+#endif
     }
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
+  }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
     char *zTemp = NULL;
-    dwLen = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
-                           NULL,
-                           error,
-                           0,
-                           (LPSTR) &zTemp,
-                           0,
-                           0);
+    dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                             FORMAT_MESSAGE_FROM_SYSTEM |
+                             FORMAT_MESSAGE_IGNORE_INSERTS,
+                             NULL,
+                             lastErrno,
+                             0,
+                             (LPSTR) &zTemp,
+                             0,
+                             0);
     if( dwLen > 0 ){
       /* allocate a buffer and convert to UTF8 */
-      zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
+      sqlite3BeginBenignMalloc();
+      zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
+      sqlite3EndBenignMalloc();
       /* free the system buffer allocated by FormatMessage */
-      LocalFree(zTemp);
+      osLocalFree(zTemp);
     }
-#endif
   }
+#endif
   if( 0 == dwLen ){
-    sqlite3_snprintf(nBuf, zBuf, "OsError 0x%x (%u)", error, error);
+    sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
   }else{
     /* copy a maximum of nBuf chars to output buffer */
     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
     /* free the UTF8 buffer */
-    free(zOut);
+    sqlite3_free(zOut);
   }
   return 0;
 }
@@ -32210,34 +39128,34 @@ static int getLastErrorMsg(int nBuf, char *zBuf){
 **
 ** This routine is invoked after an error occurs in an OS function.
 ** It logs a message using sqlite3_log() containing the current value of
-** error code and, if possible, the human-readable equivalent from 
+** error code and, if possible, the human-readable equivalent from
 ** FormatMessage.
 **
 ** The first argument passed to the macro should be the error code that
-** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN). 
+** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).
 ** The two subsequent arguments should be the name of the OS function that
-** failed and the the associated file-system path, if any.
+** failed and the associated file-system path, if any.
 */
-#define winLogError(a,b,c)     winLogErrorAtLine(a,b,c,__LINE__)
+#define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)
 static int winLogErrorAtLine(
   int errcode,                    /* SQLite error code */
+  DWORD lastErrno,                /* Win32 last error */
   const char *zFunc,              /* Name of OS function that failed */
   const char *zPath,              /* File path associated with error */
   int iLine                       /* Source line number where error occurred */
 ){
   char zMsg[500];                 /* Human readable error text */
   int i;                          /* Loop counter */
-  DWORD iErrno = GetLastError();  /* Error code */
 
   zMsg[0] = 0;
-  getLastErrorMsg(sizeof(zMsg), zMsg);
+  winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
   assert( errcode!=SQLITE_OK );
   if( zPath==0 ) zPath = "";
   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
   zMsg[i] = 0;
   sqlite3_log(errcode,
-      "os_win.c:%d: (%d) %s(%s) - %s",
-      iLine, iErrno, zFunc, zPath, zMsg
+      "os_win.c:%d: (%lu) %s(%s) - %s",
+      iLine, lastErrno, zFunc, zPath, zMsg
   );
 
   return errcode;
@@ -32245,7 +39163,7 @@ static int winLogErrorAtLine(
 
 /*
 ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
-** will be retried following a locking error - probably caused by 
+** will be retried following a locking error - probably caused by
 ** antivirus software.  Also the initial delay before the first retry.
 ** The delay increases linearly with each retry.
 */
@@ -32255,51 +39173,89 @@ static int winLogErrorAtLine(
 #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
 # define SQLITE_WIN32_IOERR_RETRY_DELAY 25
 #endif
-static int win32IoerrRetry = SQLITE_WIN32_IOERR_RETRY;
-static int win32IoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
+static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
+static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
+
+/*
+** The "winIoerrCanRetry1" macro is used to determine if a particular I/O
+** error code obtained via GetLastError() is eligible to be retried.  It
+** must accept the error code DWORD as its only argument and should return
+** non-zero if the error code is transient in nature and the operation
+** responsible for generating the original error might succeed upon being
+** retried.  The argument to this macro should be a variable.
+**
+** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it
+** is defined, it will be consulted only when the macro "winIoerrCanRetry1"
+** returns zero.  The "winIoerrCanRetry2" macro is completely optional and
+** may be used to include additional error codes in the set that should
+** result in the failing I/O operation being retried by the caller.  If
+** defined, the "winIoerrCanRetry2" macro must exhibit external semantics
+** identical to those of the "winIoerrCanRetry1" macro.
+*/
+#if !defined(winIoerrCanRetry1)
+#define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \
+                              ((a)==ERROR_SHARING_VIOLATION)    || \
+                              ((a)==ERROR_LOCK_VIOLATION)       || \
+                              ((a)==ERROR_DEV_NOT_EXIST)        || \
+                              ((a)==ERROR_NETNAME_DELETED)      || \
+                              ((a)==ERROR_SEM_TIMEOUT)          || \
+                              ((a)==ERROR_NETWORK_UNREACHABLE))
+#endif
 
 /*
 ** If a ReadFile() or WriteFile() error occurs, invoke this routine
 ** to see if it should be retried.  Return TRUE to retry.  Return FALSE
 ** to give up with an error.
 */
-static int retryIoerr(int *pnRetry){
-  DWORD e;
-  if( *pnRetry>=win32IoerrRetry ){
+static int winRetryIoerr(int *pnRetry, DWORD *pError){
+  DWORD e = osGetLastError();
+  if( *pnRetry>=winIoerrRetry ){
+    if( pError ){
+      *pError = e;
+    }
     return 0;
   }
-  e = GetLastError();
-  if( e==ERROR_ACCESS_DENIED ||
-      e==ERROR_LOCK_VIOLATION ||
-      e==ERROR_SHARING_VIOLATION ){
-    Sleep(win32IoerrRetryDelay*(1+*pnRetry));
+  if( winIoerrCanRetry1(e) ){
+    sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
+    ++*pnRetry;
+    return 1;
+  }
+#if defined(winIoerrCanRetry2)
+  else if( winIoerrCanRetry2(e) ){
+    sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
     ++*pnRetry;
     return 1;
   }
+#endif
+  if( pError ){
+    *pError = e;
+  }
   return 0;
 }
 
 /*
 ** Log a I/O error retry episode.
 */
-static void logIoerr(int nRetry){
+static void winLogIoerr(int nRetry, int lineno){
   if( nRetry ){
-    sqlite3_log(SQLITE_IOERR, 
-      "delayed %dms for lock/sharing conflict",
-      win32IoerrRetryDelay*nRetry*(nRetry+1)/2
+    sqlite3_log(SQLITE_NOTICE,
+      "delayed %dms for lock/sharing conflict at line %d",
+      winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
     );
   }
 }
 
-#if SQLITE_OS_WINCE
-/*************************************************************************
-** This section contains code for WinCE only.
+/*
+** This #if does not rely on the SQLITE_OS_WINCE define because the
+** corresponding section in "date.c" cannot use it.
 */
+#if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
+    (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
 /*
-** WindowsCE does not have a localtime() function.  So create a
-** substitute.
+** The MSVC CRT on Windows CE may not have a localtime() function.
+** So define a substitute.
 */
-/* #include <time.h> */
+/* #  include <time.h> */
 struct tm *__cdecl localtime(const time_t *t)
 {
   static struct tm y;
@@ -32310,8 +39266,8 @@ struct tm *__cdecl localtime(const time_t *t)
   t64 = (t64 + 11644473600)*10000000;
   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
   uTm.dwHighDateTime= (DWORD)(t64 >> 32);
-  FileTimeToLocalFileTime(&uTm,&lTm);
-  FileTimeToSystemTime(&lTm,&pTm);
+  osFileTimeToLocalFileTime(&uTm,&lTm);
+  osFileTimeToSystemTime(&lTm,&pTm);
   y.tm_year = pTm.wYear - 1900;
   y.tm_mon = pTm.wMonth - 1;
   y.tm_wday = pTm.wDayOfWeek;
@@ -32321,14 +39277,12 @@ struct tm *__cdecl localtime(const time_t *t)
   y.tm_sec = pTm.wSecond;
   return &y;
 }
+#endif
 
-/* This will never be called, but defined to make the code compile */
-#define GetTempPathA(a,b)
-
-#define LockFile(a,b,c,d,e)       winceLockFile(&a, b, c, d, e)
-#define UnlockFile(a,b,c,d,e)     winceUnlockFile(&a, b, c, d, e)
-#define LockFileEx(a,b,c,d,e,f)   winceLockFileEx(&a, b, c, d, e, f)
-
+#if SQLITE_OS_WINCE
+/*************************************************************************
+** This section contains code for WinCE only.
+*/
 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
 
 /*
@@ -32337,7 +39291,7 @@ struct tm *__cdecl localtime(const time_t *t)
 static void winceMutexAcquire(HANDLE h){
    DWORD dwErr;
    do {
-     dwErr = WaitForSingleObject(h, INFINITE);
+     dwErr = osWaitForSingleObject(h, INFINITE);
    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
 }
 /*
@@ -32349,78 +39303,95 @@ static void winceMutexAcquire(HANDLE h){
 ** Create the mutex and shared memory used for locking in the file
 ** descriptor pFile
 */
-static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
-  WCHAR *zTok;
-  WCHAR *zName = utf8ToUnicode(zFilename);
+static int winceCreateLock(const char *zFilename, winFile *pFile){
+  LPWSTR zTok;
+  LPWSTR zName;
+  DWORD lastErrno;
+  BOOL bLogged = FALSE;
   BOOL bInit = TRUE;
 
+  zName = winUtf8ToUnicode(zFilename);
+  if( zName==0 ){
+    /* out of memory */
+    return SQLITE_IOERR_NOMEM_BKPT;
+  }
+
   /* Initialize the local lockdata */
-  ZeroMemory(&pFile->local, sizeof(pFile->local));
+  memset(&pFile->local, 0, sizeof(pFile->local));
 
   /* Replace the backslashes from the filename and lowercase it
   ** to derive a mutex name. */
-  zTok = CharLowerW(zName);
+  zTok = osCharLowerW(zName);
   for (;*zTok;zTok++){
     if (*zTok == '\\') *zTok = '_';
   }
 
   /* Create/open the named mutex */
-  pFile->hMutex = CreateMutexW(NULL, FALSE, zName);
+  pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
   if (!pFile->hMutex){
-    pFile->lastErrno = GetLastError();
-    winLogError(SQLITE_ERROR, "winceCreateLock1", zFilename);
-    free(zName);
-    return FALSE;
+    pFile->lastErrno = osGetLastError();
+    sqlite3_free(zName);
+    return winLogError(SQLITE_IOERR, pFile->lastErrno,
+                       "winceCreateLock1", zFilename);
   }
 
   /* Acquire the mutex before continuing */
   winceMutexAcquire(pFile->hMutex);
-  
-  /* Since the names of named mutexes, semaphores, file mappings etc are 
+
+  /* Since the names of named mutexes, semaphores, file mappings etc are
   ** case-sensitive, take advantage of that by uppercasing the mutex name
   ** and using that as the shared filemapping name.
   */
-  CharUpperW(zName);
-  pFile->hShared = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
-                                       PAGE_READWRITE, 0, sizeof(winceLock),
-                                       zName);  
+  osCharUpperW(zName);
+  pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+                                        PAGE_READWRITE, 0, sizeof(winceLock),
+                                        zName);
 
-  /* Set a flag that indicates we're the first to create the memory so it 
+  /* Set a flag that indicates we're the first to create the memory so it
   ** must be zero-initialized */
-  if (GetLastError() == ERROR_ALREADY_EXISTS){
+  lastErrno = osGetLastError();
+  if (lastErrno == ERROR_ALREADY_EXISTS){
     bInit = FALSE;
   }
 
-  free(zName);
+  sqlite3_free(zName);
 
   /* If we succeeded in making the shared memory handle, map it. */
-  if (pFile->hShared){
-    pFile->shared = (winceLock*)MapViewOfFile(pFile->hShared, 
+  if( pFile->hShared ){
+    pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,
              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
     /* If mapping failed, close the shared memory handle and erase it */
-    if (!pFile->shared){
-      pFile->lastErrno = GetLastError();
-      winLogError(SQLITE_ERROR, "winceCreateLock2", zFilename);
-      CloseHandle(pFile->hShared);
+    if( !pFile->shared ){
+      pFile->lastErrno = osGetLastError();
+      winLogError(SQLITE_IOERR, pFile->lastErrno,
+                  "winceCreateLock2", zFilename);
+      bLogged = TRUE;
+      osCloseHandle(pFile->hShared);
       pFile->hShared = NULL;
     }
   }
 
   /* If shared memory could not be created, then close the mutex and fail */
-  if (pFile->hShared == NULL){
+  if( pFile->hShared==NULL ){
+    if( !bLogged ){
+      pFile->lastErrno = lastErrno;
+      winLogError(SQLITE_IOERR, pFile->lastErrno,
+                  "winceCreateLock3", zFilename);
+      bLogged = TRUE;
+    }
     winceMutexRelease(pFile->hMutex);
-    CloseHandle(pFile->hMutex);
+    osCloseHandle(pFile->hMutex);
     pFile->hMutex = NULL;
-    return FALSE;
+    return SQLITE_IOERR;
   }
-  
+
   /* Initialize the shared memory if we're supposed to */
-  if (bInit) {
-    ZeroMemory(pFile->shared, sizeof(winceLock));
+  if( bInit ){
+    memset(pFile->shared, 0, sizeof(winceLock));
   }
 
   winceMutexRelease(pFile->hMutex);
-  return TRUE;
+  return SQLITE_OK;
 }
 
 /*
@@ -32447,21 +39418,21 @@ static void winceDestroyLock(winFile *pFile){
     }
 
     /* De-reference and close our copy of the shared memory handle */
-    UnmapViewOfFile(pFile->shared);
-    CloseHandle(pFile->hShared);
+    osUnmapViewOfFile(pFile->shared);
+    osCloseHandle(pFile->hShared);
 
     /* Done with the mutex */
-    winceMutexRelease(pFile->hMutex);    
-    CloseHandle(pFile->hMutex);
+    winceMutexRelease(pFile->hMutex);
+    osCloseHandle(pFile->hMutex);
     pFile->hMutex = NULL;
   }
 }
 
-/* 
-** An implementation of the LockFile() API of windows for wince
+/*
+** An implementation of the LockFile() API of Windows for CE
 */
 static BOOL winceLockFile(
-  HANDLE *phFile,
+  LPHANDLE phFile,
   DWORD dwFileOffsetLow,
   DWORD dwFileOffsetHigh,
   DWORD nNumberOfBytesToLockLow,
@@ -32499,7 +39470,8 @@ static BOOL winceLockFile(
   }
 
   /* Want a pending lock? */
-  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToLockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
+           && nNumberOfBytesToLockLow == 1){
     /* If no pending lock has been acquired, then acquire it */
     if (pFile->shared->bPending == 0) {
       pFile->shared->bPending = TRUE;
@@ -32509,7 +39481,8 @@ static BOOL winceLockFile(
   }
 
   /* Want a reserved lock? */
-  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToLockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
+           && nNumberOfBytesToLockLow == 1){
     if (pFile->shared->bReserved == 0) {
       pFile->shared->bReserved = TRUE;
       pFile->local.bReserved = TRUE;
@@ -32522,10 +39495,10 @@ static BOOL winceLockFile(
 }
 
 /*
-** An implementation of the UnlockFile API of windows for wince
+** An implementation of the UnlockFile API of Windows for CE
 */
 static BOOL winceUnlockFile(
-  HANDLE *phFile,
+  LPHANDLE phFile,
   DWORD dwFileOffsetLow,
   DWORD dwFileOffsetHigh,
   DWORD nNumberOfBytesToUnlockLow,
@@ -32552,7 +39525,8 @@ static BOOL winceUnlockFile(
 
     /* Did we just have a reader lock? */
     else if (pFile->local.nReaders){
-      assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE || nNumberOfBytesToUnlockLow == 1);
+      assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
+             || nNumberOfBytesToUnlockLow == 1);
       pFile->local.nReaders --;
       if (pFile->local.nReaders == 0)
       {
@@ -32563,7 +39537,8 @@ static BOOL winceUnlockFile(
   }
 
   /* Releasing a pending lock */
-  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToUnlockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
+           && nNumberOfBytesToUnlockLow == 1){
     if (pFile->local.bPending){
       pFile->local.bPending = FALSE;
       pFile->shared->bPending = FALSE;
@@ -32571,7 +39546,8 @@ static BOOL winceUnlockFile(
     }
   }
   /* Releasing a reserved lock */
-  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToUnlockLow == 1){
+  else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
+           && nNumberOfBytesToUnlockLow == 1){
     if (pFile->local.bReserved) {
       pFile->local.bReserved = FALSE;
       pFile->shared->bReserved = FALSE;
@@ -32582,34 +39558,73 @@ static BOOL winceUnlockFile(
   winceMutexRelease(pFile->hMutex);
   return bReturn;
 }
+/*
+** End of the special code for wince
+*****************************************************************************/
+#endif /* SQLITE_OS_WINCE */
 
 /*
-** An implementation of the LockFileEx() API of windows for wince
+** Lock a file region.
 */
-static BOOL winceLockFileEx(
-  HANDLE *phFile,
-  DWORD dwFlags,
-  DWORD dwReserved,
-  DWORD nNumberOfBytesToLockLow,
-  DWORD nNumberOfBytesToLockHigh,
-  LPOVERLAPPED lpOverlapped
+static BOOL winLockFile(
+  LPHANDLE phFile,
+  DWORD flags,
+  DWORD offsetLow,
+  DWORD offsetHigh,
+  DWORD numBytesLow,
+  DWORD numBytesHigh
 ){
-  UNUSED_PARAMETER(dwReserved);
-  UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
-
-  /* If the caller wants a shared read lock, forward this call
-  ** to winceLockFile */
-  if (lpOverlapped->Offset == (DWORD)SHARED_FIRST &&
-      dwFlags == 1 &&
-      nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
-    return winceLockFile(phFile, SHARED_FIRST, 0, 1, 0);
+#if SQLITE_OS_WINCE
+  /*
+  ** NOTE: Windows CE is handled differently here due its lack of the Win32
+  **       API LockFile.
+  */
+  return winceLockFile(phFile, offsetLow, offsetHigh,
+                       numBytesLow, numBytesHigh);
+#else
+  if( osIsNT() ){
+    OVERLAPPED ovlp;
+    memset(&ovlp, 0, sizeof(OVERLAPPED));
+    ovlp.Offset = offsetLow;
+    ovlp.OffsetHigh = offsetHigh;
+    return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
+  }else{
+    return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
+                      numBytesHigh);
   }
-  return FALSE;
+#endif
 }
+
 /*
-** End of the special code for wince
-*****************************************************************************/
-#endif /* SQLITE_OS_WINCE */
+** Unlock a file region.
+ */
+static BOOL winUnlockFile(
+  LPHANDLE phFile,
+  DWORD offsetLow,
+  DWORD offsetHigh,
+  DWORD numBytesLow,
+  DWORD numBytesHigh
+){
+#if SQLITE_OS_WINCE
+  /*
+  ** NOTE: Windows CE is handled differently here due its lack of the Win32
+  **       API UnlockFile.
+  */
+  return winceUnlockFile(phFile, offsetLow, offsetHigh,
+                         numBytesLow, numBytesHigh);
+#else
+  if( osIsNT() ){
+    OVERLAPPED ovlp;
+    memset(&ovlp, 0, sizeof(OVERLAPPED));
+    ovlp.Offset = offsetLow;
+    ovlp.OffsetHigh = offsetHigh;
+    return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
+  }else{
+    return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
+                        numBytesHigh);
+  }
+#endif
+}
 
 /*****************************************************************************
 ** The next group of routines implement the I/O methods specified
@@ -32617,47 +39632,84 @@ static BOOL winceLockFileEx(
 ******************************************************************************/
 
 /*
-** Some microsoft compilers lack this definition.
+** Some Microsoft compilers lack this definition.
 */
 #ifndef INVALID_SET_FILE_POINTER
 # define INVALID_SET_FILE_POINTER ((DWORD)-1)
 #endif
 
 /*
-** Move the current position of the file handle passed as the first 
-** argument to offset iOffset within the file. If successful, return 0. 
+** Move the current position of the file handle passed as the first
+** argument to offset iOffset within the file. If successful, return 0.
 ** Otherwise, set pFile->lastErrno and return non-zero.
 */
-static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
+static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
+#if !SQLITE_OS_WINRT
   LONG upperBits;                 /* Most sig. 32 bits of new offset */
   LONG lowerBits;                 /* Least sig. 32 bits of new offset */
   DWORD dwRet;                    /* Value returned by SetFilePointer() */
+  DWORD lastErrno;                /* Value returned by GetLastError() */
+
+  OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
 
   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
   lowerBits = (LONG)(iOffset & 0xffffffff);
 
-  /* API oddity: If successful, SetFilePointer() returns a dword 
+  /* API oddity: If successful, SetFilePointer() returns a dword
   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
-  ** it returns INVALID_SET_FILE_POINTER. However according to MSDN, 
-  ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine 
-  ** whether an error has actually occured, it is also necessary to call 
+  ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
+  ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
+  ** whether an error has actually occurred, it is also necessary to call
   ** GetLastError().
   */
-  dwRet = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
-  if( (dwRet==INVALID_SET_FILE_POINTER && GetLastError()!=NO_ERROR) ){
-    pFile->lastErrno = GetLastError();
-    winLogError(SQLITE_IOERR_SEEK, "seekWinFile", pFile->zPath);
+  dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
+
+  if( (dwRet==INVALID_SET_FILE_POINTER
+      && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
+    pFile->lastErrno = lastErrno;
+    winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
+                "winSeekFile", pFile->zPath);
+    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
     return 1;
   }
 
+  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
   return 0;
+#else
+  /*
+  ** Same as above, except that this implementation works for WinRT.
+  */
+
+  LARGE_INTEGER x;                /* The new offset */
+  BOOL bRet;                      /* Value returned by SetFilePointerEx() */
+
+  x.QuadPart = iOffset;
+  bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);
+
+  if(!bRet){
+    pFile->lastErrno = osGetLastError();
+    winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
+                "winSeekFile", pFile->zPath);
+    OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
+    return 1;
+  }
+
+  OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
+  return 0;
+#endif
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* Forward references to VFS helper methods used for memory mapped files */
+static int winMapfile(winFile*, sqlite3_int64);
+static int winUnmapfile(winFile*);
+#endif
+
 /*
 ** Close a file.
 **
 ** It is reported that an attempt to close a handle might sometimes
-** fail.  This is a very unreasonable result, but windows is notorious
+** fail.  This is a very unreasonable result, but Windows is notorious
 ** for being unreasonable so I do not doubt that it might happen.  If
 ** the close fails, we pause for 100 milliseconds and try again.  As
 ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
@@ -32669,31 +39721,50 @@ static int winClose(sqlite3_file *id){
   winFile *pFile = (winFile*)id;
 
   assert( id!=0 );
+#ifndef SQLITE_OMIT_WAL
   assert( pFile->pShm==0 );
-  OSTRACE(("CLOSE %d\n", pFile->h));
+#endif
+  assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
+  OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  winUnmapfile(pFile);
+#endif
+
   do{
-    rc = CloseHandle(pFile->h);
+    rc = osCloseHandle(pFile->h);
     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
-  }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
+  }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
 #if SQLITE_OS_WINCE
 #define WINCE_DELETION_ATTEMPTS 3
-  winceDestroyLock(pFile);
+  {
+    winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;
+    if( pAppData==NULL || !pAppData->bNoLock ){
+      winceDestroyLock(pFile);
+    }
+  }
   if( pFile->zDeleteOnClose ){
     int cnt = 0;
     while(
-           DeleteFileW(pFile->zDeleteOnClose)==0
-        && GetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff 
+           osDeleteFileW(pFile->zDeleteOnClose)==0
+        && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
         && cnt++ < WINCE_DELETION_ATTEMPTS
     ){
-       Sleep(100);  /* Wait a little before trying again */
+       sqlite3_win32_sleep(100);  /* Wait a little before trying again */
     }
-    free(pFile->zDeleteOnClose);
+    sqlite3_free(pFile->zDeleteOnClose);
   }
 #endif
-  OSTRACE(("CLOSE %d %s\n", pFile->h, rc ? "ok" : "failed"));
+  if( rc ){
+    pFile->h = NULL;
+  }
   OpenCounter(-1);
+  OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
+           osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
   return rc ? SQLITE_OK
-            : winLogError(SQLITE_IOERR_CLOSE, "winClose", pFile->zPath);
+            : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
+                          "winClose", pFile->zPath);
 }
 
 /*
@@ -32707,29 +39778,73 @@ static int winRead(
   int amt,                   /* Number of bytes to read */
   sqlite3_int64 offset       /* Begin reading at this offset */
 ){
+#if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
+  OVERLAPPED overlapped;          /* The offset for ReadFile. */
+#endif
   winFile *pFile = (winFile*)id;  /* file handle */
   DWORD nRead;                    /* Number of bytes actually read from file */
   int nRetry = 0;                 /* Number of retrys */
 
   assert( id!=0 );
+  assert( amt>0 );
+  assert( offset>=0 );
   SimulateIOError(return SQLITE_IOERR_READ);
-  OSTRACE(("READ %d lock=%d\n", pFile->h, pFile->locktype));
+  OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
+           "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
+           pFile->h, pBuf, amt, offset, pFile->locktype));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this read request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
+      OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
+      return SQLITE_OK;
+    }else{
+      int nCopy = (int)(pFile->mmapSize - offset);
+      memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
 
-  if( seekWinFile(pFile, offset) ){
+#if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
+  if( winSeekFile(pFile, offset) ){
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_FULL;
   }
-  while( !ReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
-    if( retryIoerr(&nRetry) ) continue;
-    pFile->lastErrno = GetLastError();
-    return winLogError(SQLITE_IOERR_READ, "winRead", pFile->zPath);
-  }
-  logIoerr(nRetry);
+  while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
+#else
+  memset(&overlapped, 0, sizeof(OVERLAPPED));
+  overlapped.Offset = (LONG)(offset & 0xffffffff);
+  overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
+  while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
+         osGetLastError()!=ERROR_HANDLE_EOF ){
+#endif
+    DWORD lastErrno;
+    if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
+    pFile->lastErrno = lastErrno;
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
+    return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
+                       "winRead", pFile->zPath);
+  }
+  winLogIoerr(nRetry, __LINE__);
   if( nRead<(DWORD)amt ){
     /* Unread parts of the buffer must be zero-filled */
     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
+    OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_IOERR_SHORT_READ;
   }
 
+  OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 }
 
@@ -32743,7 +39858,7 @@ static int winWrite(
   int amt,                        /* Number of bytes to write */
   sqlite3_int64 offset            /* Offset into the file to begin writing at */
 ){
-  int rc;                         /* True if error has occured, else false */
+  int rc = 0;                     /* True if error has occurred, else false */
   winFile *pFile = (winFile*)id;  /* File handle */
   int nRetry = 0;                 /* Number of retries */
 
@@ -32752,25 +39867,73 @@ static int winWrite(
   SimulateIOError(return SQLITE_IOERR_WRITE);
   SimulateDiskfullError(return SQLITE_FULL);
 
-  OSTRACE(("WRITE %d lock=%d\n", pFile->h, pFile->locktype));
+  OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
+           "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
+           pFile->h, pBuf, amt, offset, pFile->locktype));
+
+#if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
+  /* Deal with as much of this write request as possible by transfering
+  ** data from the memory mapping using memcpy().  */
+  if( offset<pFile->mmapSize ){
+    if( offset+amt <= pFile->mmapSize ){
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
+      OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
+      return SQLITE_OK;
+    }else{
+      int nCopy = (int)(pFile->mmapSize - offset);
+      memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
+      pBuf = &((u8 *)pBuf)[nCopy];
+      amt -= nCopy;
+      offset += nCopy;
+    }
+  }
+#endif
 
-  rc = seekWinFile(pFile, offset);
+#if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
+  rc = winSeekFile(pFile, offset);
   if( rc==0 ){
+#else
+  {
+#endif
+#if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
+    OVERLAPPED overlapped;        /* The offset for WriteFile. */
+#endif
     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */
     int nRem = amt;               /* Number of bytes yet to be written */
     DWORD nWrite;                 /* Bytes written by each WriteFile() call */
+    DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */
+
+#if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
+    memset(&overlapped, 0, sizeof(OVERLAPPED));
+    overlapped.Offset = (LONG)(offset & 0xffffffff);
+    overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
+#endif
 
     while( nRem>0 ){
-      if( !WriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
-        if( retryIoerr(&nRetry) ) continue;
+#if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
+      if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
+#else
+      if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
+#endif
+        if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
+        break;
+      }
+      assert( nWrite==0 || nWrite<=(DWORD)nRem );
+      if( nWrite==0 || nWrite>(DWORD)nRem ){
+        lastErrno = osGetLastError();
         break;
       }
-      if( nWrite<=0 ) break;
+#if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
+      offset += nWrite;
+      overlapped.Offset = (LONG)(offset & 0xffffffff);
+      overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
+#endif
       aRem += nWrite;
       nRem -= nWrite;
     }
     if( nRem>0 ){
-      pFile->lastErrno = GetLastError();
+      pFile->lastErrno = lastErrno;
       rc = 1;
     }
   }
@@ -32778,12 +39941,20 @@ static int winWrite(
   if( rc ){
     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
        || ( pFile->lastErrno==ERROR_DISK_FULL )){
-      return SQLITE_FULL;
-    }
-    return winLogError(SQLITE_IOERR_WRITE, "winWrite", pFile->zPath);
+      OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
+               osGetCurrentProcessId(), pFile, pFile->h));
+      return winLogError(SQLITE_FULL, pFile->lastErrno,
+                         "winWrite1", pFile->zPath);
+    }
+    OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
+    return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
+                       "winWrite2", pFile->zPath);
   }else{
-    logIoerr(nRetry);
+    winLogIoerr(nRetry, __LINE__);
   }
+  OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 }
 
@@ -32793,11 +39964,12 @@ static int winWrite(
 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   winFile *pFile = (winFile*)id;  /* File handle object */
   int rc = SQLITE_OK;             /* Return code for this function */
+  DWORD lastErrno;
 
   assert( pFile );
-
-  OSTRACE(("TRUNCATE %d %lld\n", pFile->h, nByte));
   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
+  OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
+           osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
 
   /* If the user has configured a chunk-size for this file, truncate the
   ** file so that it consists of an integer number of chunks (i.e. the
@@ -32809,14 +39981,28 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   }
 
   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
-  if( seekWinFile(pFile, nByte) ){
-    rc = winLogError(SQLITE_IOERR_TRUNCATE, "winTruncate1", pFile->zPath);
-  }else if( 0==SetEndOfFile(pFile->h) ){
-    pFile->lastErrno = GetLastError();
-    rc = winLogError(SQLITE_IOERR_TRUNCATE, "winTruncate2", pFile->zPath);
+  if( winSeekFile(pFile, nByte) ){
+    rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
+                     "winTruncate1", pFile->zPath);
+  }else if( 0==osSetEndOfFile(pFile->h) &&
+            ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
+    pFile->lastErrno = lastErrno;
+    rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
+                     "winTruncate2", pFile->zPath);
   }
 
-  OSTRACE(("TRUNCATE %d %lld %s\n", pFile->h, nByte, rc ? "failed" : "ok"));
+#if SQLITE_MAX_MMAP_SIZE>0
+  /* If the file was truncated to a size smaller than the currently
+  ** mapped region, reduce the effective mapping size as well. SQLite will
+  ** use read() and write() to access data beyond this point from now on.
+  */
+  if( pFile->pMapRegion && nByte<pFile->mmapSize ){
+    pFile->mmapSize = nByte;
+  }
+#endif
+
+  OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
+           osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -32840,7 +40026,7 @@ static int winSync(sqlite3_file *id, int flags){
   BOOL rc;
 #endif
 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
-    (defined(SQLITE_TEST) && defined(SQLITE_DEBUG))
+    defined(SQLITE_HAVE_OS_TRACE)
   /*
   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
   ** OSTRACE() macros.
@@ -32856,13 +40042,15 @@ static int winSync(sqlite3_file *id, int flags){
       || (flags&0x0F)==SQLITE_SYNC_FULL
   );
 
-  OSTRACE(("SYNC %d lock=%d\n", pFile->h, pFile->locktype));
-
   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
   ** line is to test that doing so does not cause any problems.
   */
   SimulateDiskfullError( return SQLITE_FULL );
 
+  OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
+           osGetCurrentProcessId(), pFile, pFile->h, flags,
+           pFile->locktype));
+
 #ifndef SQLITE_TEST
   UNUSED_PARAMETER(flags);
 #else
@@ -32876,15 +40064,38 @@ static int winSync(sqlite3_file *id, int flags){
   ** no-op
   */
 #ifdef SQLITE_NO_SYNC
+  OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile, pFile->h));
   return SQLITE_OK;
 #else
-  rc = FlushFileBuffers(pFile->h);
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFile->pMapRegion ){
+    if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
+      OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_OK\n", osGetCurrentProcessId(),
+               pFile, pFile->pMapRegion));
+    }else{
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
+               pFile, pFile->pMapRegion));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winSync1", pFile->zPath);
+    }
+  }
+#endif
+  rc = osFlushFileBuffers(pFile->h);
   SimulateIOError( rc=FALSE );
   if( rc ){
+    OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
     return SQLITE_OK;
   }else{
-    pFile->lastErrno = GetLastError();
-    return winLogError(SQLITE_IOERR_FSYNC, "winSync", pFile->zPath);
+    pFile->lastErrno = osGetLastError();
+    OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
+             osGetCurrentProcessId(), pFile, pFile->h));
+    return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
+                       "winSync2", pFile->zPath);
   }
 #endif
 }
@@ -32893,22 +40104,45 @@ static int winSync(sqlite3_file *id, int flags){
 ** Determine the current size of a file in bytes
 */
 static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
-  DWORD upperBits;
-  DWORD lowerBits;
   winFile *pFile = (winFile*)id;
-  DWORD error;
+  int rc = SQLITE_OK;
 
   assert( id!=0 );
+  assert( pSize!=0 );
   SimulateIOError(return SQLITE_IOERR_FSTAT);
-  lowerBits = GetFileSize(pFile->h, &upperBits);
-  if(   (lowerBits == INVALID_FILE_SIZE)
-     && ((error = GetLastError()) != NO_ERROR) )
+  OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
+
+#if SQLITE_OS_WINRT
   {
-    pFile->lastErrno = error;
-    return winLogError(SQLITE_IOERR_FSTAT, "winFileSize", pFile->zPath);
+    FILE_STANDARD_INFO info;
+    if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,
+                                     &info, sizeof(info)) ){
+      *pSize = info.EndOfFile.QuadPart;
+    }else{
+      pFile->lastErrno = osGetLastError();
+      rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
+                       "winFileSize", pFile->zPath);
+    }
   }
-  *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
-  return SQLITE_OK;
+#else
+  {
+    DWORD upperBits;
+    DWORD lowerBits;
+    DWORD lastErrno;
+
+    lowerBits = osGetFileSize(pFile->h, &upperBits);
+    *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
+    if(   (lowerBits == INVALID_FILE_SIZE)
+       && ((lastErrno = osGetLastError())!=NO_ERROR) ){
+      pFile->lastErrno = lastErrno;
+      rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
+                       "winFileSize", pFile->zPath);
+    }
+  }
+#endif
+  OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
+           pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
+  return rc;
 }
 
 /*
@@ -32918,55 +40152,88 @@ static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
 # define LOCKFILE_FAIL_IMMEDIATELY 1
 #endif
 
+#ifndef LOCKFILE_EXCLUSIVE_LOCK
+# define LOCKFILE_EXCLUSIVE_LOCK 2
+#endif
+
+/*
+** Historically, SQLite has used both the LockFile and LockFileEx functions.
+** When the LockFile function was used, it was always expected to fail
+** immediately if the lock could not be obtained.  Also, it always expected to
+** obtain an exclusive lock.  These flags are used with the LockFileEx function
+** and reflect those expectations; therefore, they should not be changed.
+*/
+#ifndef SQLITE_LOCKFILE_FLAGS
+# define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \
+                                  LOCKFILE_EXCLUSIVE_LOCK)
+#endif
+
+/*
+** Currently, SQLite never calls the LockFileEx function without wanting the
+** call to fail immediately if the lock cannot be obtained.
+*/
+#ifndef SQLITE_LOCKFILEEX_FLAGS
+# define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)
+#endif
+
 /*
 ** Acquire a reader lock.
 ** Different API routines are called depending on whether or not this
-** is Win95 or WinNT.
+** is Win9x or WinNT.
 */
-static int getReadLock(winFile *pFile){
+static int winGetReadLock(winFile *pFile){
   int res;
-  if( isNT() ){
-    OVERLAPPED ovlp;
-    ovlp.Offset = SHARED_FIRST;
-    ovlp.OffsetHigh = 0;
-    ovlp.hEvent = 0;
-    res = LockFileEx(pFile->h, LOCKFILE_FAIL_IMMEDIATELY,
-                     0, SHARED_SIZE, 0, &ovlp);
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
+  OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
+  if( osIsNT() ){
+#if SQLITE_OS_WINCE
+    /*
+    ** NOTE: Windows CE is handled differently here due its lack of the Win32
+    **       API LockFileEx.
+    */
+    res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
+#else
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,
+                      SHARED_SIZE, 0);
+#endif
+  }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
     int lk;
     sqlite3_randomness(sizeof(lk), &lk);
     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
-    res = LockFile(pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
-#endif
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
+                      SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
   }
+#endif
   if( res == 0 ){
-    pFile->lastErrno = GetLastError();
+    pFile->lastErrno = osGetLastError();
     /* No need to log a failure to lock */
   }
+  OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));
   return res;
 }
 
 /*
 ** Undo a readlock
 */
-static int unlockReadLock(winFile *pFile){
+static int winUnlockReadLock(winFile *pFile){
   int res;
-  if( isNT() ){
-    res = UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    res = UnlockFile(pFile->h, SHARED_FIRST + pFile->sharedLockByte, 0, 1, 0);
-#endif
+  DWORD lastErrno;
+  OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
+  if( osIsNT() ){
+    res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
   }
-  if( res==0 && GetLastError()!=ERROR_NOT_LOCKED ){
-    pFile->lastErrno = GetLastError();
-    winLogError(SQLITE_IOERR_UNLOCK, "unlockReadLock", pFile->zPath);
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
   }
+#endif
+  if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
+    pFile->lastErrno = lastErrno;
+    winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
+                "winUnlockReadLock", pFile->zPath);
+  }
+  OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));
   return res;
 }
 
@@ -32998,24 +40265,31 @@ static int unlockReadLock(winFile *pFile){
 */
 static int winLock(sqlite3_file *id, int locktype){
   int rc = SQLITE_OK;    /* Return code from subroutines */
-  int res = 1;           /* Result of a windows lock call */
+  int res = 1;           /* Result of a Windows lock call */
   int newLocktype;       /* Set pFile->locktype to this value before exiting */
   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
   winFile *pFile = (winFile*)id;
-  DWORD error = NO_ERROR;
+  DWORD lastErrno = NO_ERROR;
 
   assert( id!=0 );
-  OSTRACE(("LOCK %d %d was %d(%d)\n",
-           pFile->h, locktype, pFile->locktype, pFile->sharedLockByte));
+  OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
+           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
 
   /* If there is already a lock of this type or more restrictive on the
   ** OsFile, do nothing. Don't use the end_lock: exit path, as
   ** sqlite3OsEnterMutex() hasn't been called yet.
   */
   if( pFile->locktype>=locktype ){
+    OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
     return SQLITE_OK;
   }
 
+  /* Do not allow any kind of write-lock on a read-only database
+  */
+  if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
+    return SQLITE_IOERR_LOCK;
+  }
+
   /* Make sure the locking sequence is correct
   */
   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
@@ -33027,21 +40301,33 @@ static int winLock(sqlite3_file *id, int locktype){
   ** the PENDING_LOCK byte is temporary.
   */
   newLocktype = pFile->locktype;
-  if(   (pFile->locktype==NO_LOCK)
-     || (   (locktype==EXCLUSIVE_LOCK)
-         && (pFile->locktype==RESERVED_LOCK))
+  if( pFile->locktype==NO_LOCK
+   || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)
   ){
     int cnt = 3;
-    while( cnt-->0 && (res = LockFile(pFile->h, PENDING_BYTE, 0, 1, 0))==0 ){
-      /* Try 3 times to get the pending lock.  The pending lock might be
-      ** held by another reader process who will release it momentarily.
+    while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
+                                         PENDING_BYTE, 0, 1, 0))==0 ){
+      /* Try 3 times to get the pending lock.  This is needed to work
+      ** around problems caused by indexing and/or anti-virus software on
+      ** Windows systems.
+      ** If you are using this code as a model for alternative VFSes, do not
+      ** copy this retry logic.  It is a hack intended for Windows only.
       */
-      OSTRACE(("could not get a PENDING lock. cnt=%d\n", cnt));
-      Sleep(1);
+      lastErrno = osGetLastError();
+      OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",
+               pFile->h, cnt, res));
+      if( lastErrno==ERROR_INVALID_HANDLE ){
+        pFile->lastErrno = lastErrno;
+        rc = SQLITE_IOERR_LOCK;
+        OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",
+                 pFile->h, cnt, sqlite3ErrName(rc)));
+        return rc;
+      }
+      if( cnt ) sqlite3_win32_sleep(1);
     }
     gotPendingLock = res;
     if( !res ){
-      error = GetLastError();
+      lastErrno = osGetLastError();
     }
   }
 
@@ -33049,11 +40335,11 @@ static int winLock(sqlite3_file *id, int locktype){
   */
   if( locktype==SHARED_LOCK && res ){
     assert( pFile->locktype==NO_LOCK );
-    res = getReadLock(pFile);
+    res = winGetReadLock(pFile);
     if( res ){
       newLocktype = SHARED_LOCK;
     }else{
-      error = GetLastError();
+      lastErrno = osGetLastError();
     }
   }
 
@@ -33061,11 +40347,11 @@ static int winLock(sqlite3_file *id, int locktype){
   */
   if( locktype==RESERVED_LOCK && res ){
     assert( pFile->locktype==SHARED_LOCK );
-    res = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
     if( res ){
       newLocktype = RESERVED_LOCK;
     }else{
-      error = GetLastError();
+      lastErrno = osGetLastError();
     }
   }
 
@@ -33080,15 +40366,14 @@ static int winLock(sqlite3_file *id, int locktype){
   */
   if( locktype==EXCLUSIVE_LOCK && res ){
     assert( pFile->locktype>=SHARED_LOCK );
-    res = unlockReadLock(pFile);
-    OSTRACE(("unreadlock = %d\n", res));
-    res = LockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+    res = winUnlockReadLock(pFile);
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
+                      SHARED_SIZE, 0);
     if( res ){
       newLocktype = EXCLUSIVE_LOCK;
     }else{
-      error = GetLastError();
-      OSTRACE(("error-code = %d\n", error));
-      getReadLock(pFile);
+      lastErrno = osGetLastError();
+      winGetReadLock(pFile);
     }
   }
 
@@ -33096,7 +40381,7 @@ static int winLock(sqlite3_file *id, int locktype){
   ** release it now.
   */
   if( gotPendingLock && locktype==SHARED_LOCK ){
-    UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+    winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
   }
 
   /* Update the state of the lock has held in the file descriptor then
@@ -33105,12 +40390,14 @@ static int winLock(sqlite3_file *id, int locktype){
   if( res ){
     rc = SQLITE_OK;
   }else{
-    OSTRACE(("LOCK FAILED %d trying for %d but got %d\n", pFile->h,
-           locktype, newLocktype));
-    pFile->lastErrno = error;
+    pFile->lastErrno = lastErrno;
     rc = SQLITE_BUSY;
+    OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
+             pFile->h, locktype, newLocktype));
   }
   pFile->locktype = (u8)newLocktype;
+  OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
+           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
   return rc;
 }
 
@@ -33120,24 +40407,27 @@ static int winLock(sqlite3_file *id, int locktype){
 ** non-zero, otherwise zero.
 */
 static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
-  int rc;
+  int res;
   winFile *pFile = (winFile*)id;
 
   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
+  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
 
   assert( id!=0 );
   if( pFile->locktype>=RESERVED_LOCK ){
-    rc = 1;
-    OSTRACE(("TEST WR-LOCK %d %d (local)\n", pFile->h, rc));
+    res = 1;
+    OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
   }else{
-    rc = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
-    if( rc ){
-      UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
+    if( res ){
+      winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
     }
-    rc = !rc;
-    OSTRACE(("TEST WR-LOCK %d %d (remote)\n", pFile->h, rc));
+    res = !res;
+    OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
   }
-  *pResOut = rc;
+  *pResOut = res;
+  OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
+           pFile->h, pResOut, *pResOut));
   return SQLITE_OK;
 }
 
@@ -33158,46 +40448,112 @@ static int winUnlock(sqlite3_file *id, int locktype){
   int rc = SQLITE_OK;
   assert( pFile!=0 );
   assert( locktype<=SHARED_LOCK );
-  OSTRACE(("UNLOCK %d to %d was %d(%d)\n", pFile->h, locktype,
-          pFile->locktype, pFile->sharedLockByte));
+  OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
+           pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
   type = pFile->locktype;
   if( type>=EXCLUSIVE_LOCK ){
-    UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
-    if( locktype==SHARED_LOCK && !getReadLock(pFile) ){
+    winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+    if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
       /* This should never happen.  We should always be able to
       ** reacquire the read lock */
-      rc = winLogError(SQLITE_IOERR_UNLOCK, "winUnlock", pFile->zPath);
+      rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
+                       "winUnlock", pFile->zPath);
     }
   }
   if( type>=RESERVED_LOCK ){
-    UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+    winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
   }
   if( locktype==NO_LOCK && type>=SHARED_LOCK ){
-    unlockReadLock(pFile);
+    winUnlockReadLock(pFile);
   }
   if( type>=PENDING_LOCK ){
-    UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+    winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
   }
   pFile->locktype = (u8)locktype;
+  OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
+           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
   return rc;
 }
 
+/******************************************************************************
+****************************** No-op Locking **********************************
+**
+** Of the various locking implementations available, this is by far the
+** simplest:  locking is ignored.  No attempt is made to lock the database
+** file for reading or writing.
+**
+** This locking mode is appropriate for use on read-only databases
+** (ex: databases that are burned into CD-ROM, for example.)  It can
+** also be used if the application employs some external mechanism to
+** prevent simultaneous access of the same database by two or more
+** database connections.  But there is a serious risk of database
+** corruption if this locking mode is used in situations where multiple
+** database connections are accessing the same database file at the same
+** time and one or more of those connections are writing.
+*/
+
+static int winNolockLock(sqlite3_file *id, int locktype){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(locktype);
+  return SQLITE_OK;
+}
+
+static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(pResOut);
+  return SQLITE_OK;
+}
+
+static int winNolockUnlock(sqlite3_file *id, int locktype){
+  UNUSED_PARAMETER(id);
+  UNUSED_PARAMETER(locktype);
+  return SQLITE_OK;
+}
+
+/******************* End of the no-op lock implementation *********************
+******************************************************************************/
+
+/*
+** If *pArg is initially negative then this is a query.  Set *pArg to
+** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
+**
+** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
+*/
+static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
+  if( *pArg<0 ){
+    *pArg = (pFile->ctrlFlags & mask)!=0;
+  }else if( (*pArg)==0 ){
+    pFile->ctrlFlags &= ~mask;
+  }else{
+    pFile->ctrlFlags |= mask;
+  }
+}
+
+/* Forward references to VFS helper methods used for temporary files */
+static int winGetTempname(sqlite3_vfs *, char **);
+static int winIsDir(const void *);
+static BOOL winIsDriveLetterAndColon(const char *);
+
 /*
 ** Control and query of the open file handle.
 */
 static int winFileControl(sqlite3_file *id, int op, void *pArg){
   winFile *pFile = (winFile*)id;
+  OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
   switch( op ){
     case SQLITE_FCNTL_LOCKSTATE: {
       *(int*)pArg = pFile->locktype;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
-    case SQLITE_LAST_ERRNO: {
+    case SQLITE_FCNTL_LAST_ERRNO: {
       *(int*)pArg = (int)pFile->lastErrno;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_CHUNK_SIZE: {
       pFile->szChunk = *(int *)pArg;
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_SIZE_HINT: {
@@ -33212,37 +40568,83 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
             SimulateIOErrorBenign(0);
           }
         }
+        OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
         return rc;
       }
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_PERSIST_WAL: {
-      int bPersist = *(int*)pArg;
-      if( bPersist<0 ){
-        *(int*)pArg = pFile->bPersistWal;
-      }else{
-        pFile->bPersistWal = bPersist!=0;
-      }
+      winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
-    case SQLITE_FCNTL_SYNC_OMITTED: {
+    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
+      winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
+      return SQLITE_OK;
+    }
+    case SQLITE_FCNTL_VFSNAME: {
+      *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_WIN32_AV_RETRY: {
       int *a = (int*)pArg;
       if( a[0]>0 ){
-        win32IoerrRetry = a[0];
+        winIoerrRetry = a[0];
       }else{
-        a[0] = win32IoerrRetry;
+        a[0] = winIoerrRetry;
       }
       if( a[1]>0 ){
-        win32IoerrRetryDelay = a[1];
+        winIoerrRetryDelay = a[1];
       }else{
-        a[1] = win32IoerrRetryDelay;
+        a[1] = winIoerrRetryDelay;
       }
+      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
+#ifdef SQLITE_TEST
+    case SQLITE_FCNTL_WIN32_SET_HANDLE: {
+      LPHANDLE phFile = (LPHANDLE)pArg;
+      HANDLE hOldFile = pFile->h;
+      pFile->h = *phFile;
+      *phFile = hOldFile;
+      OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",
+               hOldFile, pFile->h));
+      return SQLITE_OK;
+    }
+#endif
+    case SQLITE_FCNTL_TEMPFILENAME: {
+      char *zTFile = 0;
+      int rc = winGetTempname(pFile->pVfs, &zTFile);
+      if( rc==SQLITE_OK ){
+        *(char**)pArg = zTFile;
+      }
+      OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
+      return rc;
+    }
+#if SQLITE_MAX_MMAP_SIZE>0
+    case SQLITE_FCNTL_MMAP_SIZE: {
+      i64 newLimit = *(i64*)pArg;
+      int rc = SQLITE_OK;
+      if( newLimit>sqlite3GlobalConfig.mxMmap ){
+        newLimit = sqlite3GlobalConfig.mxMmap;
+      }
+      *(i64*)pArg = pFile->mmapSizeMax;
+      if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
+        pFile->mmapSizeMax = newLimit;
+        if( pFile->mmapSize>0 ){
+          winUnmapfile(pFile);
+          rc = winMapfile(pFile, -1);
+        }
+      }
+      OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
+      return rc;
+    }
+#endif
   }
+  OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
   return SQLITE_NOTFOUND;
 }
 
@@ -33257,35 +40659,36 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
 ** same for both.
 */
 static int winSectorSize(sqlite3_file *id){
-  assert( id!=0 );
-  return (int)(((winFile*)id)->sectorSize);
+  (void)id;
+  return SQLITE_DEFAULT_SECTOR_SIZE;
 }
 
 /*
 ** Return a vector of device characteristics.
 */
 static int winDeviceCharacteristics(sqlite3_file *id){
-  UNUSED_PARAMETER(id);
-  return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN;
+  winFile *p = (winFile*)id;
+  return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
+         ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
 }
 
-#ifndef SQLITE_OMIT_WAL
-
-/* 
+/*
 ** Windows will only let you create file view mappings
 ** on allocation size granularity boundaries.
 ** During sqlite3_os_init() we do a GetSystemInfo()
 ** to get the granularity size.
 */
-SYSTEM_INFO winSysInfo;
+static SYSTEM_INFO winSysInfo;
+
+#ifndef SQLITE_OMIT_WAL
 
 /*
 ** Helper functions to obtain and relinquish the global mutex. The
-** global mutex is used to protect the winLockInfo objects used by 
+** global mutex is used to protect the winLockInfo objects used by
 ** this file, all of which may be shared by multiple threads.
 **
-** Function winShmMutexHeld() is used to assert() that the global mutex 
-** is held when required. This function is only used as part of assert() 
+** Function winShmMutexHeld() is used to assert() that the global mutex
+** is held when required. This function is only used as part of assert()
 ** statements. e.g.
 **
 **   winShmEnterMutex()
@@ -33293,14 +40696,14 @@ SYSTEM_INFO winSysInfo;
 **   winShmLeaveMutex()
 */
 static void winShmEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 static void winShmLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
-#ifdef SQLITE_DEBUG
+#ifndef NDEBUG
 static int winShmMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
 }
 #endif
 
@@ -33315,10 +40718,10 @@ static int winShmMutexHeld(void) {
 ** this object or while reading or writing the following fields:
 **
 **      nRef
-**      pNext 
+**      pNext
 **
 ** The following fields are read-only after the object is created:
-** 
+**
 **      fid
 **      zFilename
 **
@@ -33343,7 +40746,7 @@ struct winShmNode {
   int nRef;                  /* Number of winShm objects pointing to this */
   winShm *pFirst;            /* All winShm objects pointing to this */
   winShmNode *pNext;         /* Next in list of all winShmNode objects */
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   u8 nextShmId;              /* Next available winShm.id value */
 #endif
 };
@@ -33374,7 +40777,7 @@ struct winShm {
   u8 hasMutex;               /* True if holding the winShmNode mutex */
   u16 sharedMask;            /* Mask of shared locks held */
   u16 exclMask;              /* Mask of exclusive locks held */
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   u8 id;                     /* Id of this connection with its winShmNode */
 #endif
 };
@@ -33388,48 +40791,43 @@ struct winShm {
 /*
 ** Apply advisory locks for all n bytes beginning at ofst.
 */
-#define _SHM_UNLCK  1
-#define _SHM_RDLCK  2
-#define _SHM_WRLCK  3
+#define WINSHM_UNLCK  1
+#define WINSHM_RDLCK  2
+#define WINSHM_WRLCK  3
 static int winShmSystemLock(
   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
-  int lockType,         /* _SHM_UNLCK, _SHM_RDLCK, or _SHM_WRLCK */
+  int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
   int ofst,             /* Offset to first byte to be locked/unlocked */
   int nByte             /* Number of bytes to lock or unlock */
 ){
-  OVERLAPPED ovlp;
-  DWORD dwFlags;
   int rc = 0;           /* Result code form Lock/UnlockFileEx() */
 
   /* Access to the winShmNode object is serialized by the caller */
   assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 );
 
-  /* Initialize the locking parameters */
-  dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
-  if( lockType == _SHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
-
-  memset(&ovlp, 0, sizeof(OVERLAPPED));
-  ovlp.Offset = ofst;
+  OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
+           pFile->hFile.h, lockType, ofst, nByte));
 
   /* Release/Acquire the system-level lock */
-  if( lockType==_SHM_UNLCK ){
-    rc = UnlockFileEx(pFile->hFile.h, 0, nByte, 0, &ovlp);
+  if( lockType==WINSHM_UNLCK ){
+    rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
   }else{
-    rc = LockFileEx(pFile->hFile.h, dwFlags, 0, nByte, 0, &ovlp);
+    /* Initialize the locking parameters */
+    DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
+    if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
+    rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
   }
-  
+
   if( rc!= 0 ){
     rc = SQLITE_OK;
   }else{
-    pFile->lastErrno =  GetLastError();
+    pFile->lastErrno =  osGetLastError();
     rc = SQLITE_BUSY;
   }
 
-  OSTRACE(("SHM-LOCK %d %s %s 0x%08lx\n", 
-           pFile->hFile.h,
-           rc==SQLITE_OK ? "ok" : "failed",
-           lockType==_SHM_UNLCK ? "UnlockFileEx" : "LockFileEx",
-           pFile->lastErrno));
+  OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
+           pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :
+           "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
 
   return rc;
 }
@@ -33447,31 +40845,34 @@ static int winDelete(sqlite3_vfs *,const char*,int);
 static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
   winShmNode **pp;
   winShmNode *p;
-  BOOL bRc;
   assert( winShmMutexHeld() );
+  OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
+           osGetCurrentProcessId(), deleteFlag));
   pp = &winShmNodeList;
   while( (p = *pp)!=0 ){
     if( p->nRef==0 ){
       int i;
-      if( p->mutex ) sqlite3_mutex_free(p->mutex);
+      if( p->mutex ){ sqlite3_mutex_free(p->mutex); }
       for(i=0; i<p->nRegion; i++){
-        bRc = UnmapViewOfFile(p->aRegion[i].pMap);
-        OSTRACE(("SHM-PURGE pid-%d unmap region=%d %s\n",
-                 (int)GetCurrentProcessId(), i,
-                 bRc ? "ok" : "failed"));
-        bRc = CloseHandle(p->aRegion[i].hMap);
-        OSTRACE(("SHM-PURGE pid-%d close region=%d %s\n",
-                 (int)GetCurrentProcessId(), i,
-                 bRc ? "ok" : "failed"));
-      }
-      if( p->hFile.h != INVALID_HANDLE_VALUE ){
+        BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
+        OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
+                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
+        UNUSED_VARIABLE_VALUE(bRc);
+        bRc = osCloseHandle(p->aRegion[i].hMap);
+        OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
+                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
+        UNUSED_VARIABLE_VALUE(bRc);
+      }
+      if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
         SimulateIOErrorBenign(1);
         winClose((sqlite3_file *)&p->hFile);
         SimulateIOErrorBenign(0);
       }
       if( deleteFlag ){
         SimulateIOErrorBenign(1);
+        sqlite3BeginBenignMalloc();
         winDelete(pVfs, p->zFilename, 0);
+        sqlite3EndBenignMalloc();
         SimulateIOErrorBenign(0);
       }
       *pp = p->pNext;
@@ -33502,19 +40903,17 @@ static int winOpenSharedMemory(winFile *pDbFd){
   /* Allocate space for the new sqlite3_shm object.  Also speculatively
   ** allocate space for a new winShmNode and filename.
   */
-  p = sqlite3_malloc( sizeof(*p) );
-  if( p==0 ) return SQLITE_NOMEM;
-  memset(p, 0, sizeof(*p));
+  p = sqlite3MallocZero( sizeof(*p) );
+  if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;
   nName = sqlite3Strlen30(pDbFd->zPath);
-  pNew = sqlite3_malloc( sizeof(*pShmNode) + nName + 15 );
+  pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
   if( pNew==0 ){
     sqlite3_free(p);
-    return SQLITE_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
-  memset(pNew, 0, sizeof(*pNew));
   pNew->zFilename = (char*)&pNew[1];
   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
-  sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename); 
+  sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);
 
   /* Look to see if there is an existing winShmNode that can be used.
   ** If no matching winShmNode currently exists, create a new one.
@@ -33535,41 +40934,43 @@ static int winOpenSharedMemory(winFile *pDbFd){
     pShmNode->pNext = winShmNodeList;
     winShmNodeList = pShmNode;
 
-    pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
-    if( pShmNode->mutex==0 ){
-      rc = SQLITE_NOMEM;
-      goto shm_open_err;
+    if( sqlite3GlobalConfig.bCoreMutex ){
+      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
+      if( pShmNode->mutex==0 ){
+        rc = SQLITE_IOERR_NOMEM_BKPT;
+        goto shm_open_err;
+      }
     }
 
     rc = winOpen(pDbFd->pVfs,
                  pShmNode->zFilename,             /* Name of the file (UTF-8) */
                  (sqlite3_file*)&pShmNode->hFile,  /* File handle here */
-                 SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, /* Mode flags */
+                 SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
                  0);
     if( SQLITE_OK!=rc ){
-      rc = SQLITE_CANTOPEN_BKPT;
       goto shm_open_err;
     }
 
     /* Check to see if another process is holding the dead-man switch.
-    ** If not, truncate the file to zero length. 
+    ** If not, truncate the file to zero length.
     */
-    if( winShmSystemLock(pShmNode, _SHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
+    if( winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, 0);
       if( rc!=SQLITE_OK ){
-        rc = winLogError(SQLITE_IOERR_SHMOPEN, "winOpenShm", pDbFd->zPath);
+        rc = winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
+                         "winOpenShm", pDbFd->zPath);
       }
     }
     if( rc==SQLITE_OK ){
-      winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
-      rc = winShmSystemLock(pShmNode, _SHM_RDLCK, WIN_SHM_DMS, 1);
+      winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
+      rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
     }
     if( rc ) goto shm_open_err;
   }
 
   /* Make the new connection a child of the winShmNode */
   p->pShmNode = pShmNode;
-#ifdef SQLITE_DEBUG
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
   p->id = pShmNode->nextShmId++;
 #endif
   pShmNode->nRef++;
@@ -33580,7 +40981,7 @@ static int winOpenSharedMemory(winFile *pDbFd){
   ** the cover of the winShmEnterMutex() mutex and the pointer from the
   ** new (struct winShm) object to the pShmNode has been set. All that is
   ** left to do is to link the new object into the linked list starting
-  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex 
+  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
   ** mutex.
   */
   sqlite3_mutex_enter(pShmNode->mutex);
@@ -33591,7 +40992,7 @@ static int winOpenSharedMemory(winFile *pDbFd){
 
   /* Jump here on any error */
 shm_open_err:
-  winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
+  winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
   sqlite3_free(p);
   sqlite3_free(pNew);
@@ -33600,7 +41001,7 @@ shm_open_err:
 }
 
 /*
-** Close a connection to shared-memory.  Delete the underlying 
+** Close a connection to shared-memory.  Delete the underlying
 ** storage if deleteFlag is true.
 */
 static int winShmUnmap(
@@ -33680,7 +41081,7 @@ static int winShmLock(
 
     /* Unlock the system-level locks */
     if( (mask & allMask)==0 ){
-      rc = winShmSystemLock(pShmNode, _SHM_UNLCK, ofst+WIN_SHM_BASE, n);
+      rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);
     }else{
       rc = SQLITE_OK;
     }
@@ -33689,7 +41090,7 @@ static int winShmLock(
     if( rc==SQLITE_OK ){
       p->exclMask &= ~mask;
       p->sharedMask &= ~mask;
-    } 
+    }
   }else if( flags & SQLITE_SHM_SHARED ){
     u16 allShared = 0;  /* Union of locks held by connections other than "p" */
 
@@ -33708,7 +41109,7 @@ static int winShmLock(
     /* Get shared locks at the system level, if necessary */
     if( rc==SQLITE_OK ){
       if( (allShared & mask)==0 ){
-        rc = winShmSystemLock(pShmNode, _SHM_RDLCK, ofst+WIN_SHM_BASE, n);
+        rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);
       }else{
         rc = SQLITE_OK;
       }
@@ -33728,12 +41129,12 @@ static int winShmLock(
         break;
       }
     }
-  
+
     /* Get the exclusive locks at the system level.  Then if successful
     ** also mark the local connection as being locked.
     */
     if( rc==SQLITE_OK ){
-      rc = winShmSystemLock(pShmNode, _SHM_WRLCK, ofst+WIN_SHM_BASE, n);
+      rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);
       if( rc==SQLITE_OK ){
         assert( (p->sharedMask & mask)==0 );
         p->exclMask |= mask;
@@ -33741,14 +41142,14 @@ static int winShmLock(
     }
   }
   sqlite3_mutex_leave(pShmNode->mutex);
-  OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x %s\n",
-           p->id, (int)GetCurrentProcessId(), p->sharedMask, p->exclMask,
-           rc ? "failed" : "ok"));
+  OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
+           osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
+           sqlite3ErrName(rc)));
   return rc;
 }
 
 /*
-** Implement a memory barrier or memory fence on shared memory.  
+** Implement a memory barrier or memory fence on shared memory.
 **
 ** All loads and stores begun before the barrier must complete before
 ** any load or store begun after the barrier.
@@ -33757,28 +41158,28 @@ static void winShmBarrier(
   sqlite3_file *fd          /* Database holding the shared memory */
 ){
   UNUSED_PARAMETER(fd);
-  /* MemoryBarrier(); // does not work -- do not know why not */
-  winShmEnterMutex();
+  sqlite3MemoryBarrier();   /* compiler-defined memory barrier */
+  winShmEnterMutex();       /* Also mutex, for redundancy */
   winShmLeaveMutex();
 }
 
 /*
-** This function is called to obtain a pointer to region iRegion of the 
-** shared-memory associated with the database file fd. Shared-memory regions 
-** are numbered starting from zero. Each shared-memory region is szRegion 
+** This function is called to obtain a pointer to region iRegion of the
+** shared-memory associated with the database file fd. Shared-memory regions
+** are numbered starting from zero. Each shared-memory region is szRegion
 ** bytes in size.
 **
 ** If an error occurs, an error code is returned and *pp is set to NULL.
 **
 ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory
 ** region has not been allocated (by any client, including one running in a
-** separate process), then *pp is set to NULL and SQLITE_OK returned. If 
-** isWrite is non-zero and the requested shared-memory region has not yet 
+** separate process), then *pp is set to NULL and SQLITE_OK returned. If
+** isWrite is non-zero and the requested shared-memory region has not yet
 ** been allocated, it is allocated by this function.
 **
 ** If the shared-memory region has already been allocated or is allocated by
-** this call as described above, then it is mapped into this processes 
-** address space (if it is not already), *pp is set to point to the mapped 
+** this call as described above, then it is mapped into this processes
+** address space (if it is not already), *pp is set to point to the mapped
 ** memory and SQLITE_OK returned.
 */
 static int winShmMap(
@@ -33789,16 +41190,16 @@ static int winShmMap(
   void volatile **pp              /* OUT: Mapped memory */
 ){
   winFile *pDbFd = (winFile*)fd;
-  winShm *p = pDbFd->pShm;
+  winShm *pShm = pDbFd->pShm;
   winShmNode *pShmNode;
   int rc = SQLITE_OK;
 
-  if( !p ){
+  if( !pShm ){
     rc = winOpenSharedMemory(pDbFd);
     if( rc!=SQLITE_OK ) return rc;
-    p = pDbFd->pShm;
+    pShm = pDbFd->pShm;
   }
-  pShmNode = p->pShmNode;
+  pShmNode = pShm->pShmNode;
 
   sqlite3_mutex_enter(pShmNode->mutex);
   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
@@ -33816,7 +41217,8 @@ static int winShmMap(
     */
     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);
     if( rc!=SQLITE_OK ){
-      rc = winLogError(SQLITE_IOERR_SHMSIZE, "winShmMap1", pDbFd->zPath);
+      rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
+                       "winShmMap1", pDbFd->zPath);
       goto shmpage_out;
     }
 
@@ -33830,45 +41232,63 @@ static int winShmMap(
       if( !isWrite ) goto shmpage_out;
       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);
       if( rc!=SQLITE_OK ){
-        rc = winLogError(SQLITE_IOERR_SHMSIZE, "winShmMap2", pDbFd->zPath);
+        rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
+                         "winShmMap2", pDbFd->zPath);
         goto shmpage_out;
       }
     }
 
     /* Map the requested memory region into this processes address space. */
-    apNew = (struct ShmRegion *)sqlite3_realloc(
+    apNew = (struct ShmRegion *)sqlite3_realloc64(
         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
     );
     if( !apNew ){
-      rc = SQLITE_IOERR_NOMEM;
+      rc = SQLITE_IOERR_NOMEM_BKPT;
       goto shmpage_out;
     }
     pShmNode->aRegion = apNew;
 
     while( pShmNode->nRegion<=iRegion ){
-      HANDLE hMap;                /* file-mapping handle */
+      HANDLE hMap = NULL;         /* file-mapping handle */
       void *pMap = 0;             /* Mapped memory region */
-     
-      hMap = CreateFileMapping(pShmNode->hFile.h, 
+
+#if SQLITE_OS_WINRT
+      hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
+          NULL, PAGE_READWRITE, nByte, NULL
+      );
+#elif defined(SQLITE_WIN32_HAS_WIDE)
+      hMap = osCreateFileMappingW(pShmNode->hFile.h,
+          NULL, PAGE_READWRITE, 0, nByte, NULL
+      );
+#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
+      hMap = osCreateFileMappingA(pShmNode->hFile.h,
           NULL, PAGE_READWRITE, 0, nByte, NULL
       );
-      OSTRACE(("SHM-MAP pid-%d create region=%d nbyte=%d %s\n",
-               (int)GetCurrentProcessId(), pShmNode->nRegion, nByte,
+#endif
+      OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
+               osGetCurrentProcessId(), pShmNode->nRegion, nByte,
                hMap ? "ok" : "failed"));
       if( hMap ){
         int iOffset = pShmNode->nRegion*szRegion;
         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
-        pMap = MapViewOfFile(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
+#if SQLITE_OS_WINRT
+        pMap = osMapViewOfFileFromApp(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
+            iOffset - iOffsetShift, szRegion + iOffsetShift
+        );
+#else
+        pMap = osMapViewOfFile(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
             0, iOffset - iOffsetShift, szRegion + iOffsetShift
         );
-        OSTRACE(("SHM-MAP pid-%d map region=%d offset=%d size=%d %s\n",
-                 (int)GetCurrentProcessId(), pShmNode->nRegion, iOffset, szRegion,
-                 pMap ? "ok" : "failed"));
+#endif
+        OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
+                 osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
+                 szRegion, pMap ? "ok" : "failed"));
       }
       if( !pMap ){
-        pShmNode->lastErrno = GetLastError();
-        rc = winLogError(SQLITE_IOERR_SHMMAP, "winShmMap3", pDbFd->zPath);
-        if( hMap ) CloseHandle(hMap);
+        pShmNode->lastErrno = osGetLastError();
+        rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,
+                         "winShmMap3", pDbFd->zPath);
+        if( hMap ) osCloseHandle(hMap);
         goto shmpage_out;
       }
 
@@ -33899,6 +41319,233 @@ shmpage_out:
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
 /*
+** Cleans up the mapped region of the specified file, if any.
+*/
+#if SQLITE_MAX_MMAP_SIZE>0
+static int winUnmapfile(winFile *pFile){
+  assert( pFile!=0 );
+  OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
+           "mmapSize=%lld, mmapSizeActual=%lld, mmapSizeMax=%lld\n",
+           osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
+           pFile->mmapSize, pFile->mmapSizeActual, pFile->mmapSizeMax));
+  if( pFile->pMapRegion ){
+    if( !osUnmapViewOfFile(pFile->pMapRegion) ){
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
+               "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
+               pFile->pMapRegion));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winUnmapfile1", pFile->zPath);
+    }
+    pFile->pMapRegion = 0;
+    pFile->mmapSize = 0;
+    pFile->mmapSizeActual = 0;
+  }
+  if( pFile->hMap!=NULL ){
+    if( !osCloseHandle(pFile->hMap) ){
+      pFile->lastErrno = osGetLastError();
+      OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
+               osGetCurrentProcessId(), pFile, pFile->hMap));
+      return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
+                         "winUnmapfile2", pFile->zPath);
+    }
+    pFile->hMap = NULL;
+  }
+  OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFile));
+  return SQLITE_OK;
+}
+
+/*
+** Memory map or remap the file opened by file-descriptor pFd (if the file
+** is already mapped, the existing mapping is replaced by the new). Or, if
+** there already exists a mapping for this file, and there are still
+** outstanding xFetch() references to it, this function is a no-op.
+**
+** If parameter nByte is non-negative, then it is the requested size of
+** the mapping to create. Otherwise, if nByte is less than zero, then the
+** requested size is the size of the file on disk. The actual size of the
+** created mapping is either the requested size or the value configured
+** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
+**
+** SQLITE_OK is returned if no error occurs (even if the mapping is not
+** recreated as a result of outstanding references) or an SQLite error
+** code otherwise.
+*/
+static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
+  sqlite3_int64 nMap = nByte;
+  int rc;
+
+  assert( nMap>=0 || pFd->nFetchOut==0 );
+  OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
+           osGetCurrentProcessId(), pFd, nByte));
+
+  if( pFd->nFetchOut>0 ) return SQLITE_OK;
+
+  if( nMap<0 ){
+    rc = winFileSize((sqlite3_file*)pFd, &nMap);
+    if( rc ){
+      OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
+               osGetCurrentProcessId(), pFd));
+      return SQLITE_IOERR_FSTAT;
+    }
+  }
+  if( nMap>pFd->mmapSizeMax ){
+    nMap = pFd->mmapSizeMax;
+  }
+  nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
+
+  if( nMap==0 && pFd->mmapSize>0 ){
+    winUnmapfile(pFd);
+  }
+  if( nMap!=pFd->mmapSize ){
+    void *pNew = 0;
+    DWORD protect = PAGE_READONLY;
+    DWORD flags = FILE_MAP_READ;
+
+    winUnmapfile(pFd);
+#ifdef SQLITE_MMAP_READWRITE
+    if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
+      protect = PAGE_READWRITE;
+      flags |= FILE_MAP_WRITE;
+    }
+#endif
+#if SQLITE_OS_WINRT
+    pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
+#elif defined(SQLITE_WIN32_HAS_WIDE)
+    pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
+                                (DWORD)((nMap>>32) & 0xffffffff),
+                                (DWORD)(nMap & 0xffffffff), NULL);
+#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
+    pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
+                                (DWORD)((nMap>>32) & 0xffffffff),
+                                (DWORD)(nMap & 0xffffffff), NULL);
+#endif
+    if( pFd->hMap==NULL ){
+      pFd->lastErrno = osGetLastError();
+      rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
+                       "winMapfile1", pFd->zPath);
+      /* Log the error, but continue normal operation using xRead/xWrite */
+      OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",
+               osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
+      return SQLITE_OK;
+    }
+    assert( (nMap % winSysInfo.dwPageSize)==0 );
+    assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
+#if SQLITE_OS_WINRT
+    pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
+#else
+    pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
+#endif
+    if( pNew==NULL ){
+      osCloseHandle(pFd->hMap);
+      pFd->hMap = NULL;
+      pFd->lastErrno = osGetLastError();
+      rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
+                       "winMapfile2", pFd->zPath);
+      /* Log the error, but continue normal operation using xRead/xWrite */
+      OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",
+               osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
+      return SQLITE_OK;
+    }
+    pFd->pMapRegion = pNew;
+    pFd->mmapSize = nMap;
+    pFd->mmapSizeActual = nMap;
+  }
+
+  OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), pFd));
+  return SQLITE_OK;
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+/*
+** If possible, return a pointer to a mapping of file fd starting at offset
+** iOff. The mapping must be valid for at least nAmt bytes.
+**
+** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
+** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
+** Finally, if an error does occur, return an SQLite error code. The final
+** value of *pp is undefined in this case.
+**
+** If this function does return a pointer, the caller must eventually
+** release the reference by calling winUnfetch().
+*/
+static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
+#if SQLITE_MAX_MMAP_SIZE>0
+  winFile *pFd = (winFile*)fd;   /* The underlying database file */
+#endif
+  *pp = 0;
+
+  OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
+           osGetCurrentProcessId(), fd, iOff, nAmt, pp));
+
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFd->mmapSizeMax>0 ){
+    if( pFd->pMapRegion==0 ){
+      int rc = winMapfile(pFd, -1);
+      if( rc!=SQLITE_OK ){
+        OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
+                 osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
+        return rc;
+      }
+    }
+    if( pFd->mmapSize >= iOff+nAmt ){
+      *pp = &((u8 *)pFd->pMapRegion)[iOff];
+      pFd->nFetchOut++;
+    }
+  }
+#endif
+
+  OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), fd, pp, *pp));
+  return SQLITE_OK;
+}
+
+/*
+** If the third argument is non-NULL, then this function releases a
+** reference obtained by an earlier call to winFetch(). The second
+** argument passed to this function must be the same as the corresponding
+** argument that was passed to the winFetch() invocation.
+**
+** Or, if the third argument is NULL, then this function is being called
+** to inform the VFS layer that, according to POSIX, any existing mapping
+** may now be invalid and should be unmapped.
+*/
+static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
+#if SQLITE_MAX_MMAP_SIZE>0
+  winFile *pFd = (winFile*)fd;   /* The underlying database file */
+
+  /* If p==0 (unmap the entire file) then there must be no outstanding
+  ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
+  ** then there must be at least one outstanding.  */
+  assert( (p==0)==(pFd->nFetchOut==0) );
+
+  /* If p!=0, it must match the iOff value. */
+  assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
+
+  OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
+           osGetCurrentProcessId(), pFd, iOff, p));
+
+  if( p ){
+    pFd->nFetchOut--;
+  }else{
+    /* FIXME:  If Windows truly always prevents truncating or deleting a
+    ** file while a mapping is held, then the following winUnmapfile() call
+    ** is unnecessary can be omitted - potentially improving
+    ** performance.  */
+    winUnmapfile(pFd);
+  }
+
+  assert( pFd->nFetchOut>=0 );
+#endif
+
+  OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
+           osGetCurrentProcessId(), fd));
+  return SQLITE_OK;
+}
+
+/*
 ** Here ends the implementation of all sqlite3_file methods.
 **
 ********************** End sqlite3_file Methods *******************************
@@ -33909,7 +41556,7 @@ shmpage_out:
 ** sqlite3_file for win32.
 */
 static const sqlite3_io_methods winIoMethod = {
-  2,                              /* iVersion */
+  3,                              /* iVersion */
   winClose,                       /* xClose */
   winRead,                        /* xRead */
   winWrite,                       /* xWrite */
@@ -33925,7 +41572,47 @@ static const sqlite3_io_methods winIoMethod = {
   winShmMap,                      /* xShmMap */
   winShmLock,                     /* xShmLock */
   winShmBarrier,                  /* xShmBarrier */
-  winShmUnmap                     /* xShmUnmap */
+  winShmUnmap,                    /* xShmUnmap */
+  winFetch,                       /* xFetch */
+  winUnfetch                      /* xUnfetch */
+};
+
+/*
+** This vector defines all the methods that can operate on an
+** sqlite3_file for win32 without performing any locking.
+*/
+static const sqlite3_io_methods winIoNolockMethod = {
+  3,                              /* iVersion */
+  winClose,                       /* xClose */
+  winRead,                        /* xRead */
+  winWrite,                       /* xWrite */
+  winTruncate,                    /* xTruncate */
+  winSync,                        /* xSync */
+  winFileSize,                    /* xFileSize */
+  winNolockLock,                  /* xLock */
+  winNolockUnlock,                /* xUnlock */
+  winNolockCheckReservedLock,     /* xCheckReservedLock */
+  winFileControl,                 /* xFileControl */
+  winSectorSize,                  /* xSectorSize */
+  winDeviceCharacteristics,       /* xDeviceCharacteristics */
+  winShmMap,                      /* xShmMap */
+  winShmLock,                     /* xShmLock */
+  winShmBarrier,                  /* xShmBarrier */
+  winShmUnmap,                    /* xShmUnmap */
+  winFetch,                       /* xFetch */
+  winUnfetch                      /* xUnfetch */
+};
+
+static winVfsAppData winAppData = {
+  &winIoMethod,       /* pMethod */
+  0,                  /* pAppData */
+  0                   /* bNoLock */
+};
+
+static winVfsAppData winNolockAppData = {
+  &winIoNolockMethod, /* pMethod */
+  0,                  /* pAppData */
+  1                   /* bNoLock */
 };
 
 /****************************************************************************
@@ -33935,111 +41622,339 @@ static const sqlite3_io_methods winIoMethod = {
 ** sqlite3_vfs object.
 */
 
+#if defined(__CYGWIN__)
+/*
+** Convert a filename from whatever the underlying operating system
+** supports for filenames into UTF-8.  Space to hold the result is
+** obtained from malloc and must be freed by the calling function.
+*/
+static char *winConvertToUtf8Filename(const void *zFilename){
+  char *zConverted = 0;
+  if( osIsNT() ){
+    zConverted = winUnicodeToUtf8(zFilename);
+  }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());
+  }
+#endif
+  /* caller will handle out of memory */
+  return zConverted;
+}
+#endif
+
 /*
 ** Convert a UTF-8 filename into whatever form the underlying
 ** operating system wants filenames in.  Space to hold the result
 ** is obtained from malloc and must be freed by the calling
 ** function.
 */
-static void *convertUtf8Filename(const char *zFilename){
+static void *winConvertFromUtf8Filename(const char *zFilename){
   void *zConverted = 0;
-  if( isNT() ){
-    zConverted = utf8ToUnicode(zFilename);
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    zConverted = sqlite3_win32_utf8_to_mbcs(zFilename);
-#endif
+  if( osIsNT() ){
+    zConverted = winUtf8ToUnicode(zFilename);
   }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());
+  }
+#endif
   /* caller will handle out of memory */
   return zConverted;
 }
 
 /*
-** Create a temporary file name in zBuf.  zBuf must be big enough to
-** hold at pVfs->mxPathname characters.
+** This function returns non-zero if the specified UTF-8 string buffer
+** ends with a directory separator character or one was successfully
+** added to it.
+*/
+static int winMakeEndInDirSep(int nBuf, char *zBuf){
+  if( zBuf ){
+    int nLen = sqlite3Strlen30(zBuf);
+    if( nLen>0 ){
+      if( winIsDirSep(zBuf[nLen-1]) ){
+        return 1;
+      }else if( nLen+1<nBuf ){
+        zBuf[nLen] = winGetDirSep();
+        zBuf[nLen+1] = '\0';
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Create a temporary file name and store the resulting pointer into pzBuf.
+** The pointer returned in pzBuf must be freed via sqlite3_free().
 */
-static int getTempname(int nBuf, char *zBuf){
+static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
   static char zChars[] =
     "abcdefghijklmnopqrstuvwxyz"
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "0123456789";
   size_t i, j;
-  char zTempPath[MAX_PATH+1];
+  int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);
+  int nMax, nBuf, nDir, nLen;
+  char *zBuf;
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
-  ** function failing. 
+  ** function failing.
   */
   SimulateIOError( return SQLITE_IOERR );
 
+  /* Allocate a temporary buffer to store the fully qualified file
+  ** name for the temporary file.  If this fails, we cannot continue.
+  */
+  nMax = pVfs->mxPathname; nBuf = nMax + 2;
+  zBuf = sqlite3MallocZero( nBuf );
+  if( !zBuf ){
+    OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+    return SQLITE_IOERR_NOMEM_BKPT;
+  }
+
+  /* Figure out the effective temporary directory.  First, check if one
+  ** has been explicitly set by the application; otherwise, use the one
+  ** configured by the operating system.
+  */
+  nDir = nMax - (nPre + 15);
+  assert( nDir>0 );
   if( sqlite3_temp_directory ){
-    sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", sqlite3_temp_directory);
-  }else if( isNT() ){
+    int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
+    if( nDirLen>0 ){
+      if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
+        nDirLen++;
+      }
+      if( nDirLen>nDir ){
+        sqlite3_free(zBuf);
+        OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
+        return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
+      }
+      sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
+    }
+  }
+#if defined(__CYGWIN__)
+  else{
+    static const char *azDirs[] = {
+       0, /* getenv("SQLITE_TMPDIR") */
+       0, /* getenv("TMPDIR") */
+       0, /* getenv("TMP") */
+       0, /* getenv("TEMP") */
+       0, /* getenv("USERPROFILE") */
+       "/var/tmp",
+       "/usr/tmp",
+       "/tmp",
+       ".",
+       0        /* List terminator */
+    };
+    unsigned int i;
+    const char *zDir = 0;
+
+    if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
+    if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
+    if( !azDirs[2] ) azDirs[2] = getenv("TMP");
+    if( !azDirs[3] ) azDirs[3] = getenv("TEMP");
+    if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");
+    for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
+      void *zConverted;
+      if( zDir==0 ) continue;
+      /* If the path starts with a drive letter followed by the colon
+      ** character, assume it is already a native Win32 path; otherwise,
+      ** it must be converted to a native Win32 path via the Cygwin API
+      ** prior to using it.
+      */
+      if( winIsDriveLetterAndColon(zDir) ){
+        zConverted = winConvertFromUtf8Filename(zDir);
+        if( !zConverted ){
+          sqlite3_free(zBuf);
+          OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+          return SQLITE_IOERR_NOMEM_BKPT;
+        }
+        if( winIsDir(zConverted) ){
+          sqlite3_snprintf(nMax, zBuf, "%s", zDir);
+          sqlite3_free(zConverted);
+          break;
+        }
+        sqlite3_free(zConverted);
+      }else{
+        zConverted = sqlite3MallocZero( nMax+1 );
+        if( !zConverted ){
+          sqlite3_free(zBuf);
+          OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+          return SQLITE_IOERR_NOMEM_BKPT;
+        }
+        if( cygwin_conv_path(
+                osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
+                zConverted, nMax+1)<0 ){
+          sqlite3_free(zConverted);
+          sqlite3_free(zBuf);
+          OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));
+          return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,
+                             "winGetTempname2", zDir);
+        }
+        if( winIsDir(zConverted) ){
+          /* At this point, we know the candidate directory exists and should
+          ** be used.  However, we may need to convert the string containing
+          ** its name into UTF-8 (i.e. if it is UTF-16 right now).
+          */
+          char *zUtf8 = winConvertToUtf8Filename(zConverted);
+          if( !zUtf8 ){
+            sqlite3_free(zConverted);
+            sqlite3_free(zBuf);
+            OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+            return SQLITE_IOERR_NOMEM_BKPT;
+          }
+          sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
+          sqlite3_free(zUtf8);
+          sqlite3_free(zConverted);
+          break;
+        }
+        sqlite3_free(zConverted);
+      }
+    }
+  }
+#elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)
+  else if( osIsNT() ){
     char *zMulti;
-    WCHAR zWidePath[MAX_PATH];
-    GetTempPathW(MAX_PATH-30, zWidePath);
-    zMulti = unicodeToUtf8(zWidePath);
+    LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );
+    if( !zWidePath ){
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+      return SQLITE_IOERR_NOMEM_BKPT;
+    }
+    if( osGetTempPathW(nMax, zWidePath)==0 ){
+      sqlite3_free(zWidePath);
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
+      return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
+                         "winGetTempname2", 0);
+    }
+    zMulti = winUnicodeToUtf8(zWidePath);
     if( zMulti ){
-      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zMulti);
-      free(zMulti);
+      sqlite3_snprintf(nMax, zBuf, "%s", zMulti);
+      sqlite3_free(zMulti);
+      sqlite3_free(zWidePath);
     }else{
-      return SQLITE_NOMEM;
+      sqlite3_free(zWidePath);
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
+  }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
     char *zUtf8;
-    char zMbcsPath[MAX_PATH];
-    GetTempPathA(MAX_PATH-30, zMbcsPath);
-    zUtf8 = sqlite3_win32_mbcs_to_utf8(zMbcsPath);
+    char *zMbcsPath = sqlite3MallocZero( nMax );
+    if( !zMbcsPath ){
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+      return SQLITE_IOERR_NOMEM_BKPT;
+    }
+    if( osGetTempPathA(nMax, zMbcsPath)==0 ){
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
+      return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
+                         "winGetTempname3", 0);
+    }
+    zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());
     if( zUtf8 ){
-      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zUtf8);
-      free(zUtf8);
+      sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
+      sqlite3_free(zUtf8);
     }else{
-      return SQLITE_NOMEM;
+      sqlite3_free(zBuf);
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
-#endif
   }
+#endif /* SQLITE_WIN32_HAS_ANSI */
+#endif /* !SQLITE_OS_WINRT */
 
-  /* Check that the output buffer is large enough for the temporary file 
-  ** name. If it is not, return SQLITE_ERROR.
+  /*
+  ** Check to make sure the temporary directory ends with an appropriate
+  ** separator.  If it does not and there is not enough space left to add
+  ** one, fail.
   */
-  if( (sqlite3Strlen30(zTempPath) + sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX) + 17) >= nBuf ){
-    return SQLITE_ERROR;
+  if( !winMakeEndInDirSep(nDir+1, zBuf) ){
+    sqlite3_free(zBuf);
+    OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
+    return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);
+  }
+
+  /*
+  ** Check that the output buffer is large enough for the temporary file
+  ** name in the following format:
+  **
+  **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"
+  **
+  ** If not, return SQLITE_ERROR.  The number 17 is used here in order to
+  ** account for the space used by the 15 character random suffix and the
+  ** two trailing NUL characters.  The final directory separator character
+  ** has already added if it was not already present.
+  */
+  nLen = sqlite3Strlen30(zBuf);
+  if( (nLen + nPre + 17) > nBuf ){
+    sqlite3_free(zBuf);
+    OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
+    return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);
   }
 
-  for(i=sqlite3Strlen30(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
-  zTempPath[i] = 0;
+  sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);
 
-  sqlite3_snprintf(nBuf-17, zBuf,
-                   "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath);
   j = sqlite3Strlen30(zBuf);
   sqlite3_randomness(15, &zBuf[j]);
   for(i=0; i<15; i++, j++){
     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
   }
   zBuf[j] = 0;
+  zBuf[j+1] = 0;
+  *pzBuf = zBuf;
 
-  OSTRACE(("TEMP FILENAME: %s\n", zBuf));
-  return SQLITE_OK; 
+  OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
+  return SQLITE_OK;
+}
+
+/*
+** Return TRUE if the named file is really a directory.  Return false if
+** it is something other than a directory, or if there is any kind of memory
+** allocation failure.
+*/
+static int winIsDir(const void *zConverted){
+  DWORD attr;
+  int rc = 0;
+  DWORD lastErrno;
+
+  if( osIsNT() ){
+    int cnt = 0;
+    WIN32_FILE_ATTRIBUTE_DATA sAttrData;
+    memset(&sAttrData, 0, sizeof(sAttrData));
+    while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
+                             GetFileExInfoStandard,
+                             &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
+    if( !rc ){
+      return 0; /* Invalid name? */
+    }
+    attr = sAttrData.dwFileAttributes;
+#if SQLITE_OS_WINCE==0
+  }else{
+    attr = osGetFileAttributesA((char*)zConverted);
+#endif
+  }
+  return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
 }
 
 /*
 ** Open a file.
 */
 static int winOpen(
-  sqlite3_vfs *pVfs,        /* Not used */
+  sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */
   const char *zName,        /* Name of the file (UTF-8) */
   sqlite3_file *id,         /* Write the SQLite file handle here */
   int flags,                /* Open mode flags */
   int *pOutFlags            /* Status return flags */
 ){
   HANDLE h;
+  DWORD lastErrno = 0;
   DWORD dwDesiredAccess;
   DWORD dwShareMode;
   DWORD dwCreationDisposition;
@@ -34047,6 +41962,7 @@ static int winOpen(
 #if SQLITE_OS_WINCE
   int isTemp = 0;
 #endif
+  winVfsAppData *pAppData;
   winFile *pFile = (winFile*)id;
   void *zConverted;              /* Filename in OS encoding */
   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
@@ -34055,7 +41971,7 @@ static int winOpen(
   /* If argument zPath is a NULL pointer, this function is required to open
   ** a temporary file. Use this buffer to store the file name in.
   */
-  char zTmpname[MAX_PATH+1];     /* Buffer used to create temp filename */
+  char *zTmpname = 0; /* For temporary filename, if necessary. */
 
   int rc = SQLITE_OK;            /* Function Return Code */
 #if !defined(NDEBUG) || SQLITE_OS_WINCE
@@ -34065,22 +41981,23 @@ static int winOpen(
   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
   int isCreate     = (flags & SQLITE_OPEN_CREATE);
-#ifndef NDEBUG
   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
-#endif
   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
 
 #ifndef NDEBUG
   int isOpenJournal = (isCreate && (
-        eType==SQLITE_OPEN_MASTER_JOURNAL 
-     || eType==SQLITE_OPEN_MAIN_JOURNAL 
+        eType==SQLITE_OPEN_MASTER_JOURNAL
+     || eType==SQLITE_OPEN_MAIN_JOURNAL
      || eType==SQLITE_OPEN_WAL
   ));
 #endif
 
-  /* Check the following statements are true: 
+  OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
+           zUtf8Name, id, flags, pOutFlags));
+
+  /* Check the following statements are true:
   **
-  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 
+  **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
   **   (b) if CREATE is set, then READWRITE must also be set, and
   **   (c) if EXCLUSIVE is set, then CREATE must also be set.
   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
@@ -34090,7 +42007,7 @@ static int winOpen(
   assert(isExclusive==0 || isCreate);
   assert(isDelete==0 || isCreate);
 
-  /* The main DB, main journal, WAL file and master journal are never 
+  /* The main DB, main journal, WAL file and master journal are never
   ** automatically deleted. Nor are they ever temporary files.  */
   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
@@ -34098,33 +42015,56 @@ static int winOpen(
   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
 
   /* Assert that the upper layer has set one of the "file-type" flags. */
-  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 
-       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 
-       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL 
+  assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
+       || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
+       || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL
        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
   );
 
-  assert( id!=0 );
-  UNUSED_PARAMETER(pVfs);
-
+  assert( pFile!=0 );
+  memset(pFile, 0, sizeof(winFile));
   pFile->h = INVALID_HANDLE_VALUE;
 
-  /* If the second argument to this function is NULL, generate a 
-  ** temporary file name to use 
+#if SQLITE_OS_WINRT
+  if( !zUtf8Name && !sqlite3_temp_directory ){
+    sqlite3_log(SQLITE_ERROR,
+        "sqlite3_temp_directory variable should be set for WinRT");
+  }
+#endif
+
+  /* If the second argument to this function is NULL, generate a
+  ** temporary file name to use
   */
   if( !zUtf8Name ){
-    assert(isDelete && !isOpenJournal);
-    rc = getTempname(MAX_PATH+1, zTmpname);
+    assert( isDelete && !isOpenJournal );
+    rc = winGetTempname(pVfs, &zTmpname);
     if( rc!=SQLITE_OK ){
+      OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
       return rc;
     }
     zUtf8Name = zTmpname;
   }
 
+  /* Database filenames are double-zero terminated if they are not
+  ** URIs with parameters.  Hence, they can always be passed into
+  ** sqlite3_uri_parameter().
+  */
+  assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
+       zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );
+
   /* Convert the filename to the system encoding. */
-  zConverted = convertUtf8Filename(zUtf8Name);
+  zConverted = winConvertFromUtf8Filename(zUtf8Name);
   if( zConverted==0 ){
-    return SQLITE_NOMEM;
+    sqlite3_free(zTmpname);
+    OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
+    return SQLITE_IOERR_NOMEM_BKPT;
+  }
+
+  if( winIsDir(zConverted) ){
+    sqlite3_free(zConverted);
+    sqlite3_free(zTmpname);
+    OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
+    return SQLITE_CANTOPEN_ISDIR;
   }
 
   if( isReadWrite ){
@@ -34133,8 +42073,8 @@ static int winOpen(
     dwDesiredAccess = GENERIC_READ;
   }
 
-  /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is 
-  ** created. SQLite doesn't use it to indicate "exclusive access" 
+  /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is
+  ** created. SQLite doesn't use it to indicate "exclusive access"
   ** as it is usually understood.
   */
   if( isExclusive ){
@@ -34169,43 +42109,64 @@ static int winOpen(
   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
 #endif
 
-  if( isNT() ){
-    while( (h = CreateFileW((WCHAR*)zConverted,
-                            dwDesiredAccess,
-                            dwShareMode, NULL,
-                            dwCreationDisposition,
-                            dwFlagsAndAttributes,
-                            NULL))==INVALID_HANDLE_VALUE &&
-                            retryIoerr(&cnt) ){}
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    while( (h = CreateFileA((char*)zConverted,
-                            dwDesiredAccess,
-                            dwShareMode, NULL,
-                            dwCreationDisposition,
-                            dwFlagsAndAttributes,
-                            NULL))==INVALID_HANDLE_VALUE &&
-                            retryIoerr(&cnt) ){}
+  if( osIsNT() ){
+#if SQLITE_OS_WINRT
+    CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
+    extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
+    extendedParameters.dwFileAttributes =
+            dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
+    extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
+    extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
+    extendedParameters.lpSecurityAttributes = NULL;
+    extendedParameters.hTemplateFile = NULL;
+    while( (h = osCreateFile2((LPCWSTR)zConverted,
+                              dwDesiredAccess,
+                              dwShareMode,
+                              dwCreationDisposition,
+                              &extendedParameters))==INVALID_HANDLE_VALUE &&
+                              winRetryIoerr(&cnt, &lastErrno) ){
+               /* Noop */
+    }
+#else
+    while( (h = osCreateFileW((LPCWSTR)zConverted,
+                              dwDesiredAccess,
+                              dwShareMode, NULL,
+                              dwCreationDisposition,
+                              dwFlagsAndAttributes,
+                              NULL))==INVALID_HANDLE_VALUE &&
+                              winRetryIoerr(&cnt, &lastErrno) ){
+               /* Noop */
+    }
 #endif
   }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    while( (h = osCreateFileA((LPCSTR)zConverted,
+                              dwDesiredAccess,
+                              dwShareMode, NULL,
+                              dwCreationDisposition,
+                              dwFlagsAndAttributes,
+                              NULL))==INVALID_HANDLE_VALUE &&
+                              winRetryIoerr(&cnt, &lastErrno) ){
+               /* Noop */
+    }
+  }
+#endif
+  winLogIoerr(cnt, __LINE__);
 
-  logIoerr(cnt);
-
-  OSTRACE(("OPEN %d %s 0x%lx %s\n", 
-           h, zName, dwDesiredAccess, 
-           h==INVALID_HANDLE_VALUE ? "failed" : "ok"));
+  OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
+           dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
 
   if( h==INVALID_HANDLE_VALUE ){
-    pFile->lastErrno = GetLastError();
-    winLogError(SQLITE_CANTOPEN, "winOpen", zUtf8Name);
-    free(zConverted);
+    pFile->lastErrno = lastErrno;
+    winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
+    sqlite3_free(zConverted);
+    sqlite3_free(zTmpname);
     if( isReadWrite && !isExclusive ){
-      return winOpen(pVfs, zName, id, 
-             ((flags|SQLITE_OPEN_READONLY)&~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)), pOutFlags);
+      return winOpen(pVfs, zName, id,
+         ((flags|SQLITE_OPEN_READONLY) &
+                     ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
+         pOutFlags);
     }else{
       return SQLITE_CANTOPEN_BKPT;
     }
@@ -34219,31 +42180,53 @@ static int winOpen(
     }
   }
 
-  memset(pFile, 0, sizeof(*pFile));
-  pFile->pMethod = &winIoMethod;
-  pFile->h = h;
-  pFile->lastErrno = NO_ERROR;
-  pFile->pVfs = pVfs;
-  pFile->pShm = 0;
-  pFile->zPath = zName;
-  pFile->sectorSize = getSectorSize(pVfs, zUtf8Name);
+  OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
+           "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
+           *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
+
+  pAppData = (winVfsAppData*)pVfs->pAppData;
 
 #if SQLITE_OS_WINCE
-  if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
-       && !winceCreateLock(zName, pFile)
-  ){
-    CloseHandle(h);
-    free(zConverted);
-    return SQLITE_CANTOPEN_BKPT;
+  {
+    if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
+         && ((pAppData==NULL) || !pAppData->bNoLock)
+         && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
+    ){
+      osCloseHandle(h);
+      sqlite3_free(zConverted);
+      sqlite3_free(zTmpname);
+      OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
+      return rc;
+    }
   }
   if( isTemp ){
     pFile->zDeleteOnClose = zConverted;
   }else
 #endif
   {
-    free(zConverted);
+    sqlite3_free(zConverted);
   }
 
+  sqlite3_free(zTmpname);
+  pFile->pMethod = pAppData ? pAppData->pMethod : &winIoMethod;
+  pFile->pVfs = pVfs;
+  pFile->h = h;
+  if( isReadonly ){
+    pFile->ctrlFlags |= WINFILE_RDONLY;
+  }
+  if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
+    pFile->ctrlFlags |= WINFILE_PSOW;
+  }
+  pFile->lastErrno = NO_ERROR;
+  pFile->zPath = zName;
+#if SQLITE_MAX_MMAP_SIZE>0
+  pFile->hMap = NULL;
+  pFile->pMapRegion = 0;
+  pFile->mmapSize = 0;
+  pFile->mmapSizeActual = 0;
+  pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
+#endif
+
   OpenCounter(+1);
   return rc;
 }
@@ -34251,7 +42234,7 @@ static int winOpen(
 /*
 ** Delete the named file.
 **
-** Note that windows does not allow a file to be deleted if some other
+** Note that Windows does not allow a file to be deleted if some other
 ** process has it open.  Sometimes a virus scanner or indexing program
 ** will open a journal file shortly after it is created in order to do
 ** whatever it does.  While this other process is holding the
@@ -34267,44 +42250,106 @@ static int winDelete(
 ){
   int cnt = 0;
   int rc;
+  DWORD attr;
+  DWORD lastErrno = 0;
   void *zConverted;
   UNUSED_PARAMETER(pVfs);
   UNUSED_PARAMETER(syncDir);
 
   SimulateIOError(return SQLITE_IOERR_DELETE);
-  zConverted = convertUtf8Filename(zFilename);
+  OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
+
+  zConverted = winConvertFromUtf8Filename(zFilename);
   if( zConverted==0 ){
-    return SQLITE_NOMEM;
+    OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
-  if( isNT() ){
-    rc = 1;
-    while( GetFileAttributesW(zConverted)!=INVALID_FILE_ATTRIBUTES &&
-           (rc = DeleteFileW(zConverted))==0 && retryIoerr(&cnt) ){}
-    rc = rc ? SQLITE_OK : SQLITE_ERROR;
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    rc = 1;
-    while( GetFileAttributesA(zConverted)!=INVALID_FILE_ATTRIBUTES &&
-           (rc = DeleteFileA(zConverted))==0 && retryIoerr(&cnt) ){}
-    rc = rc ? SQLITE_OK : SQLITE_ERROR;
+  if( osIsNT() ){
+    do {
+#if SQLITE_OS_WINRT
+      WIN32_FILE_ATTRIBUTE_DATA sAttrData;
+      memset(&sAttrData, 0, sizeof(sAttrData));
+      if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
+                                  &sAttrData) ){
+        attr = sAttrData.dwFileAttributes;
+      }else{
+        lastErrno = osGetLastError();
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
+          rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
+        }else{
+          rc = SQLITE_ERROR;
+        }
+        break;
+      }
+#else
+      attr = osGetFileAttributesW(zConverted);
 #endif
+      if ( attr==INVALID_FILE_ATTRIBUTES ){
+        lastErrno = osGetLastError();
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
+          rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
+        }else{
+          rc = SQLITE_ERROR;
+        }
+        break;
+      }
+      if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
+        rc = SQLITE_ERROR; /* Files only. */
+        break;
+      }
+      if ( osDeleteFileW(zConverted) ){
+        rc = SQLITE_OK; /* Deleted OK. */
+        break;
+      }
+      if ( !winRetryIoerr(&cnt, &lastErrno) ){
+        rc = SQLITE_ERROR; /* No more retries. */
+        break;
+      }
+    } while(1);
   }
-  if( rc ){
-    rc = winLogError(SQLITE_IOERR_DELETE, "winDelete", zFilename);
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    do {
+      attr = osGetFileAttributesA(zConverted);
+      if ( attr==INVALID_FILE_ATTRIBUTES ){
+        lastErrno = osGetLastError();
+        if( lastErrno==ERROR_FILE_NOT_FOUND
+         || lastErrno==ERROR_PATH_NOT_FOUND ){
+          rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
+        }else{
+          rc = SQLITE_ERROR;
+        }
+        break;
+      }
+      if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
+        rc = SQLITE_ERROR; /* Files only. */
+        break;
+      }
+      if ( osDeleteFileA(zConverted) ){
+        rc = SQLITE_OK; /* Deleted OK. */
+        break;
+      }
+      if ( !winRetryIoerr(&cnt, &lastErrno) ){
+        rc = SQLITE_ERROR; /* No more retries. */
+        break;
+      }
+    } while(1);
+  }
+#endif
+  if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
+    rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
   }else{
-    logIoerr(cnt);
+    winLogIoerr(cnt, __LINE__);
   }
-  free(zConverted);
-  OSTRACE(("DELETE \"%s\" %s\n", zFilename, (rc ? "failed" : "ok" )));
+  sqlite3_free(zConverted);
+  OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
   return rc;
 }
 
 /*
-** Check the existance and status of a file.
+** Check the existence and status of a file.
 */
 static int winAccess(
   sqlite3_vfs *pVfs,         /* Not used on win32 */
@@ -34314,52 +42359,54 @@ static int winAccess(
 ){
   DWORD attr;
   int rc = 0;
+  DWORD lastErrno = 0;
   void *zConverted;
   UNUSED_PARAMETER(pVfs);
 
   SimulateIOError( return SQLITE_IOERR_ACCESS; );
-  zConverted = convertUtf8Filename(zFilename);
+  OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
+           zFilename, flags, pResOut));
+
+  zConverted = winConvertFromUtf8Filename(zFilename);
   if( zConverted==0 ){
-    return SQLITE_NOMEM;
+    OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
-  if( isNT() ){
+  if( osIsNT() ){
     int cnt = 0;
     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
     memset(&sAttrData, 0, sizeof(sAttrData));
-    while( !(rc = GetFileAttributesExW((WCHAR*)zConverted,
-                             GetFileExInfoStandard, 
-                             &sAttrData)) && retryIoerr(&cnt) ){}
+    while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
+                             GetFileExInfoStandard,
+                             &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
     if( rc ){
       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
       ** as if it does not exist.
       */
       if(    flags==SQLITE_ACCESS_EXISTS
-          && sAttrData.nFileSizeHigh==0 
+          && sAttrData.nFileSizeHigh==0
           && sAttrData.nFileSizeLow==0 ){
         attr = INVALID_FILE_ATTRIBUTES;
       }else{
         attr = sAttrData.dwFileAttributes;
       }
     }else{
-      logIoerr(cnt);
-      if( GetLastError()!=ERROR_FILE_NOT_FOUND ){
-        winLogError(SQLITE_IOERR_ACCESS, "winAccess", zFilename);
-        free(zConverted);
-        return SQLITE_IOERR_ACCESS;
+      winLogIoerr(cnt, __LINE__);
+      if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
+        sqlite3_free(zConverted);
+        return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
+                           zFilename);
       }else{
         attr = INVALID_FILE_ATTRIBUTES;
       }
     }
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    attr = GetFileAttributesA((char*)zConverted);
-#endif
   }
-  free(zConverted);
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    attr = osGetFileAttributesA((char*)zConverted);
+  }
+#endif
+  sqlite3_free(zConverted);
   switch( flags ){
     case SQLITE_ACCESS_READ:
     case SQLITE_ACCESS_EXISTS:
@@ -34373,9 +42420,57 @@ static int winAccess(
       assert(!"Invalid flags argument");
   }
   *pResOut = rc;
+  OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
+           zFilename, pResOut, *pResOut));
   return SQLITE_OK;
 }
 
+/*
+** Returns non-zero if the specified path name starts with a drive letter
+** followed by a colon character.
+*/
+static BOOL winIsDriveLetterAndColon(
+  const char *zPathname
+){
+  return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );
+}
+
+/*
+** Returns non-zero if the specified path name should be used verbatim.  If
+** non-zero is returned from this function, the calling function must simply
+** use the provided path name verbatim -OR- resolve it into a full path name
+** using the GetFullPathName Win32 API function (if available).
+*/
+static BOOL winIsVerbatimPathname(
+  const char *zPathname
+){
+  /*
+  ** If the path name starts with a forward slash or a backslash, it is either
+  ** a legal UNC name, a volume relative path, or an absolute path name in the
+  ** "Unix" format on Windows.  There is no easy way to differentiate between
+  ** the final two cases; therefore, we return the safer return value of TRUE
+  ** so that callers of this function will simply use it verbatim.
+  */
+  if ( winIsDirSep(zPathname[0]) ){
+    return TRUE;
+  }
+
+  /*
+  ** If the path name starts with a letter and a colon it is either a volume
+  ** relative path or an absolute path.  Callers of this function must not
+  ** attempt to treat it as a relative path name (i.e. they should simply use
+  ** it verbatim).
+  */
+  if ( winIsDriveLetterAndColon(zPathname) ){
+    return TRUE;
+  }
+
+  /*
+  ** If we get to this point, the path name should almost certainly be a purely
+  ** relative one (i.e. not a UNC name, not absolute, and not volume relative).
+  */
+  return FALSE;
+}
 
 /*
 ** Turn a relative pathname into a full pathname.  Write the full
@@ -34388,201 +42483,241 @@ static int winFullPathname(
   int nFull,                    /* Size of output buffer in bytes */
   char *zFull                   /* Output buffer */
 ){
-  
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
+  DWORD nByte;
+  void *zConverted;
+  char *zOut;
+#endif
+
+  /* If this path name begins with "/X:", where "X" is any alphabetic
+  ** character, discard the initial "/" from the pathname.
+  */
+  if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){
+    zRelative++;
+  }
+
 #if defined(__CYGWIN__)
   SimulateIOError( return SQLITE_ERROR );
   UNUSED_PARAMETER(nFull);
-  cygwin_conv_to_full_win32_path(zRelative, zFull);
+  assert( nFull>=pVfs->mxPathname );
+  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
+    /*
+    ** NOTE: We are dealing with a relative path name and the data
+    **       directory has been set.  Therefore, use it as the basis
+    **       for converting the relative path name to an absolute
+    **       one by prepending the data directory and a slash.
+    */
+    char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
+    if( !zOut ){
+      return SQLITE_IOERR_NOMEM_BKPT;
+    }
+    if( cygwin_conv_path(
+            (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
+            CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){
+      sqlite3_free(zOut);
+      return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
+                         "winFullPathname1", zRelative);
+    }else{
+      char *zUtf8 = winConvertToUtf8Filename(zOut);
+      if( !zUtf8 ){
+        sqlite3_free(zOut);
+        return SQLITE_IOERR_NOMEM_BKPT;
+      }
+      sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
+                       sqlite3_data_directory, winGetDirSep(), zUtf8);
+      sqlite3_free(zUtf8);
+      sqlite3_free(zOut);
+    }
+  }else{
+    char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
+    if( !zOut ){
+      return SQLITE_IOERR_NOMEM_BKPT;
+    }
+    if( cygwin_conv_path(
+            (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
+            zRelative, zOut, pVfs->mxPathname+1)<0 ){
+      sqlite3_free(zOut);
+      return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
+                         "winFullPathname2", zRelative);
+    }else{
+      char *zUtf8 = winConvertToUtf8Filename(zOut);
+      if( !zUtf8 ){
+        sqlite3_free(zOut);
+        return SQLITE_IOERR_NOMEM_BKPT;
+      }
+      sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
+      sqlite3_free(zUtf8);
+      sqlite3_free(zOut);
+    }
+  }
   return SQLITE_OK;
 #endif
 
-#if SQLITE_OS_WINCE
+#if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)
   SimulateIOError( return SQLITE_ERROR );
-  UNUSED_PARAMETER(nFull);
   /* WinCE has no concept of a relative pathname, or so I am told. */
-  sqlite3_snprintf(pVfs->mxPathname, zFull, "%s", zRelative);
+  /* WinRT has no way to convert a relative path to an absolute one. */
+  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
+    /*
+    ** NOTE: We are dealing with a relative path name and the data
+    **       directory has been set.  Therefore, use it as the basis
+    **       for converting the relative path name to an absolute
+    **       one by prepending the data directory and a backslash.
+    */
+    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
+                     sqlite3_data_directory, winGetDirSep(), zRelative);
+  }else{
+    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
+  }
   return SQLITE_OK;
 #endif
 
-#if !SQLITE_OS_WINCE && !defined(__CYGWIN__)
-  int nByte;
-  void *zConverted;
-  char *zOut;
-
-  /* If this path name begins with "/X:", where "X" is any alphabetic
-  ** character, discard the initial "/" from the pathname.
-  */
-  if( zRelative[0]=='/' && sqlite3Isalpha(zRelative[1]) && zRelative[2]==':' ){
-    zRelative++;
-  }
-
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
   ** function failing. This function could fail if, for example, the
   ** current working directory has been unlinked.
   */
   SimulateIOError( return SQLITE_ERROR );
-  UNUSED_PARAMETER(nFull);
-  zConverted = convertUtf8Filename(zRelative);
-  if( isNT() ){
-    WCHAR *zTemp;
-    nByte = GetFullPathNameW((WCHAR*)zConverted, 0, 0, 0) + 3;
-    zTemp = malloc( nByte*sizeof(zTemp[0]) );
+  if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
+    /*
+    ** NOTE: We are dealing with a relative path name and the data
+    **       directory has been set.  Therefore, use it as the basis
+    **       for converting the relative path name to an absolute
+    **       one by prepending the data directory and a backslash.
+    */
+    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
+                     sqlite3_data_directory, winGetDirSep(), zRelative);
+    return SQLITE_OK;
+  }
+  zConverted = winConvertFromUtf8Filename(zRelative);
+  if( zConverted==0 ){
+    return SQLITE_IOERR_NOMEM_BKPT;
+  }
+  if( osIsNT() ){
+    LPWSTR zTemp;
+    nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
+    if( nByte==0 ){
+      sqlite3_free(zConverted);
+      return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
+                         "winFullPathname1", zRelative);
+    }
+    nByte += 3;
+    zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
     if( zTemp==0 ){
-      free(zConverted);
-      return SQLITE_NOMEM;
+      sqlite3_free(zConverted);
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
-    GetFullPathNameW((WCHAR*)zConverted, nByte, zTemp, 0);
-    free(zConverted);
-    zOut = unicodeToUtf8(zTemp);
-    free(zTemp);
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
+    nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
+    if( nByte==0 ){
+      sqlite3_free(zConverted);
+      sqlite3_free(zTemp);
+      return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
+                         "winFullPathname2", zRelative);
+    }
+    sqlite3_free(zConverted);
+    zOut = winUnicodeToUtf8(zTemp);
+    sqlite3_free(zTemp);
+  }
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
     char *zTemp;
-    nByte = GetFullPathNameA((char*)zConverted, 0, 0, 0) + 3;
-    zTemp = malloc( nByte*sizeof(zTemp[0]) );
+    nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
+    if( nByte==0 ){
+      sqlite3_free(zConverted);
+      return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
+                         "winFullPathname3", zRelative);
+    }
+    nByte += 3;
+    zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
     if( zTemp==0 ){
-      free(zConverted);
-      return SQLITE_NOMEM;
+      sqlite3_free(zConverted);
+      return SQLITE_IOERR_NOMEM_BKPT;
     }
-    GetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
-    free(zConverted);
-    zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
-    free(zTemp);
-#endif
+    nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
+    if( nByte==0 ){
+      sqlite3_free(zConverted);
+      sqlite3_free(zTemp);
+      return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
+                         "winFullPathname4", zRelative);
+    }
+    sqlite3_free(zConverted);
+    zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
+    sqlite3_free(zTemp);
   }
+#endif
   if( zOut ){
-    sqlite3_snprintf(pVfs->mxPathname, zFull, "%s", zOut);
-    free(zOut);
+    sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);
+    sqlite3_free(zOut);
     return SQLITE_OK;
   }else{
-    return SQLITE_NOMEM;
+    return SQLITE_IOERR_NOMEM_BKPT;
   }
 #endif
 }
 
-/*
-** Get the sector size of the device used to store
-** file.
-*/
-static int getSectorSize(
-    sqlite3_vfs *pVfs,
-    const char *zRelative     /* UTF-8 file name */
-){
-  DWORD bytesPerSector = SQLITE_DEFAULT_SECTOR_SIZE;
-  /* GetDiskFreeSpace is not supported under WINCE */
-#if SQLITE_OS_WINCE
-  UNUSED_PARAMETER(pVfs);
-  UNUSED_PARAMETER(zRelative);
-#else
-  char zFullpath[MAX_PATH+1];
-  int rc;
-  DWORD dwRet = 0;
-  DWORD dwDummy;
-
-  /*
-  ** We need to get the full path name of the file
-  ** to get the drive letter to look up the sector
-  ** size.
-  */
-  SimulateIOErrorBenign(1);
-  rc = winFullPathname(pVfs, zRelative, MAX_PATH, zFullpath);
-  SimulateIOErrorBenign(0);
-  if( rc == SQLITE_OK )
-  {
-    void *zConverted = convertUtf8Filename(zFullpath);
-    if( zConverted ){
-      if( isNT() ){
-        /* trim path to just drive reference */
-        WCHAR *p = zConverted;
-        for(;*p;p++){
-          if( *p == '\\' ){
-            *p = '\0';
-            break;
-          }
-        }
-        dwRet = GetDiskFreeSpaceW((WCHAR*)zConverted,
-                                  &dwDummy,
-                                  &bytesPerSector,
-                                  &dwDummy,
-                                  &dwDummy);
-      }else{
-        /* trim path to just drive reference */
-        char *p = (char *)zConverted;
-        for(;*p;p++){
-          if( *p == '\\' ){
-            *p = '\0';
-            break;
-          }
-        }
-        dwRet = GetDiskFreeSpaceA((char*)zConverted,
-                                  &dwDummy,
-                                  &bytesPerSector,
-                                  &dwDummy,
-                                  &dwDummy);
-      }
-      free(zConverted);
-    }
-    if( !dwRet ){
-      bytesPerSector = SQLITE_DEFAULT_SECTOR_SIZE;
-    }
-  }
-#endif
-  return (int) bytesPerSector; 
-}
-
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
 /*
 ** Interfaces for opening a shared library, finding entry points
 ** within the shared library, and closing the shared library.
 */
-/*
-** Interfaces for opening a shared library, finding entry points
-** within the shared library, and closing the shared library.
-*/
 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
   HANDLE h;
-  void *zConverted = convertUtf8Filename(zFilename);
+#if defined(__CYGWIN__)
+  int nFull = pVfs->mxPathname+1;
+  char *zFull = sqlite3MallocZero( nFull );
+  void *zConverted = 0;
+  if( zFull==0 ){
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
+    return 0;
+  }
+  if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
+    sqlite3_free(zFull);
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
+    return 0;
+  }
+  zConverted = winConvertFromUtf8Filename(zFull);
+  sqlite3_free(zFull);
+#else
+  void *zConverted = winConvertFromUtf8Filename(zFilename);
   UNUSED_PARAMETER(pVfs);
+#endif
   if( zConverted==0 ){
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
     return 0;
   }
-  if( isNT() ){
-    h = LoadLibraryW((WCHAR*)zConverted);
-/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed. 
-** Since the ASCII version of these Windows API do not exist for WINCE,
-** it's important to not reference them for WINCE builds.
-*/
-#if SQLITE_OS_WINCE==0
-  }else{
-    h = LoadLibraryA((char*)zConverted);
+  if( osIsNT() ){
+#if SQLITE_OS_WINRT
+    h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
+#else
+    h = osLoadLibraryW((LPCWSTR)zConverted);
 #endif
   }
-  free(zConverted);
+#ifdef SQLITE_WIN32_HAS_ANSI
+  else{
+    h = osLoadLibraryA((char*)zConverted);
+  }
+#endif
+  OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
+  sqlite3_free(zConverted);
   return (void*)h;
 }
 static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
   UNUSED_PARAMETER(pVfs);
-  getLastErrorMsg(nBuf, zBufOut);
+  winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
 }
-static void (*winDlSym(sqlite3_vfs *pVfs, void *pHandle, const char *zSymbol))(void){
+static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
+  FARPROC proc;
   UNUSED_PARAMETER(pVfs);
-#if SQLITE_OS_WINCE
-  /* The GetProcAddressA() routine is only available on wince. */
-  return (void(*)(void))GetProcAddressA((HANDLE)pHandle, zSymbol);
-#else
-  /* All other windows platforms expect GetProcAddress() to take
-  ** an Ansi string regardless of the _UNICODE setting */
-  return (void(*)(void))GetProcAddress((HANDLE)pHandle, zSymbol);
-#endif
+  proc = osGetProcAddressA((HANDLE)pH, zSym);
+  OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",
+           (void*)pH, zSym, (void*)proc));
+  return (void(*)(void))proc;
 }
 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
   UNUSED_PARAMETER(pVfs);
-  FreeLibrary((HANDLE)pHandle);
+  osFreeLibrary((HANDLE)pHandle);
+  OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
 }
 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
   #define winDlOpen  0
@@ -34591,41 +42726,85 @@ static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
   #define winDlClose 0
 #endif
 
+/* State information for the randomness gatherer. */
+typedef struct EntropyGatherer EntropyGatherer;
+struct EntropyGatherer {
+  unsigned char *a;   /* Gather entropy into this buffer */
+  int na;             /* Size of a[] in bytes */
+  int i;              /* XOR next input into a[i] */
+  int nXor;           /* Number of XOR operations done */
+};
+
+#if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
+/* Mix sz bytes of entropy into p. */
+static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){
+  int j, k;
+  for(j=0, k=p->i; j<sz; j++){
+    p->a[k++] ^= x[j];
+    if( k>=p->na ) k = 0;
+  }
+  p->i = k;
+  p->nXor += sz;
+}
+#endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */
 
 /*
 ** Write up to nBuf bytes of randomness into zBuf.
 */
 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
-  int n = 0;
+#if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
   UNUSED_PARAMETER(pVfs);
-#if defined(SQLITE_TEST)
-  n = nBuf;
   memset(zBuf, 0, nBuf);
+  return nBuf;
 #else
-  if( sizeof(SYSTEMTIME)<=nBuf-n ){
+  EntropyGatherer e;
+  UNUSED_PARAMETER(pVfs);
+  memset(zBuf, 0, nBuf);
+#if defined(_MSC_VER) && _MSC_VER>=1400 && !SQLITE_OS_WINCE
+  rand_s((unsigned int*)zBuf); /* rand_s() is not available with MinGW */
+#endif /* defined(_MSC_VER) && _MSC_VER>=1400 */
+  e.a = (unsigned char*)zBuf;
+  e.na = nBuf;
+  e.nXor = 0;
+  e.i = 0;
+  {
     SYSTEMTIME x;
-    GetSystemTime(&x);
-    memcpy(&zBuf[n], &x, sizeof(x));
-    n += sizeof(x);
+    osGetSystemTime(&x);
+    xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));
   }
-  if( sizeof(DWORD)<=nBuf-n ){
-    DWORD pid = GetCurrentProcessId();
-    memcpy(&zBuf[n], &pid, sizeof(pid));
-    n += sizeof(pid);
+  {
+    DWORD pid = osGetCurrentProcessId();
+    xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));
   }
-  if( sizeof(DWORD)<=nBuf-n ){
-    DWORD cnt = GetTickCount();
-    memcpy(&zBuf[n], &cnt, sizeof(cnt));
-    n += sizeof(cnt);
+#if SQLITE_OS_WINRT
+  {
+    ULONGLONG cnt = osGetTickCount64();
+    xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));
   }
-  if( sizeof(LARGE_INTEGER)<=nBuf-n ){
+#else
+  {
+    DWORD cnt = osGetTickCount();
+    xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));
+  }
+#endif /* SQLITE_OS_WINRT */
+  {
     LARGE_INTEGER i;
-    QueryPerformanceCounter(&i);
-    memcpy(&zBuf[n], &i, sizeof(i));
-    n += sizeof(i);
+    osQueryPerformanceCounter(&i);
+    xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));
   }
-#endif
-  return n;
+#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
+  {
+    UUID id;
+    memset(&id, 0, sizeof(UUID));
+    osUuidCreate(&id);
+    xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
+    memset(&id, 0, sizeof(UUID));
+    osUuidCreateSequential(&id);
+    xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
+  }
+#endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */
+  return e.nXor>nBuf ? nBuf : e.nXor;
+#endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */
 }
 
 
@@ -34633,7 +42812,7 @@ static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
 ** Sleep for a little while.  Return the amount of time slept.
 */
 static int winSleep(sqlite3_vfs *pVfs, int microsec){
-  Sleep((microsec+999)/1000);
+  sqlite3_win32_sleep((microsec+999)/1000);
   UNUSED_PARAMETER(pVfs);
   return ((microsec+999)/1000)*1000;
 }
@@ -34654,12 +42833,12 @@ SQLITE_API int sqlite3_current_time = 0;  /* Fake system time in seconds since 1
 ** epoch of noon in Greenwich on November 24, 4714 B.C according to the
 ** proleptic Gregorian calendar.
 **
-** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date 
+** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date
 ** cannot be found.
 */
 static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
-  /* FILETIME structure is a 64-bit value representing the number of 
-     100-nanosecond intervals since January 1, 1601 (= JD 2305813.5). 
+  /* FILETIME structure is a 64-bit value representing the number of
+     100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
   */
   FILETIME ft;
   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;
@@ -34667,22 +42846,23 @@ static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
 #endif
   /* 2^32 - to avoid use of LL and warnings in gcc */
-  static const sqlite3_int64 max32BitValue = 
-      (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 + (sqlite3_int64)294967296;
+  static const sqlite3_int64 max32BitValue =
+      (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
+      (sqlite3_int64)294967296;
 
 #if SQLITE_OS_WINCE
   SYSTEMTIME time;
-  GetSystemTime(&time);
+  osGetSystemTime(&time);
   /* if SystemTimeToFileTime() fails, it returns zero. */
-  if (!SystemTimeToFileTime(&time,&ft)){
+  if (!osSystemTimeToFileTime(&time,&ft)){
     return SQLITE_ERROR;
   }
 #else
-  GetSystemTimeAsFileTime( &ft );
+  osGetSystemTimeAsFileTime( &ft );
 #endif
 
   *piNow = winFiletimeEpoch +
-            ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) + 
+            ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +
                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;
 
 #ifdef SQLITE_TEST
@@ -34711,8 +42891,8 @@ static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
 
 /*
 ** The idea is that this function works like a combination of
-** GetLastError() and FormatMessage() on windows (or errno and
-** strerror_r() on unix). After an error is returned by an OS
+** GetLastError() and FormatMessage() on Windows (or errno and
+** strerror_r() on Unix). After an error is returned by an OS
 ** function, SQLite calls this function with zBuf pointing to
 ** a buffer of nBuf bytes. The OS layer should populate the
 ** buffer with a nul-terminated UTF-8 encoded error message
@@ -34740,52 +42920,153 @@ static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
 */
 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
+  DWORD e = osGetLastError();
   UNUSED_PARAMETER(pVfs);
-  return getLastErrorMsg(nBuf, zBuf);
+  if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);
+  return e;
 }
 
-
-
 /*
 ** Initialize and deinitialize the operating system interface.
 */
-SQLITE_API int sqlite3_os_init(void){
+SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void){
   static sqlite3_vfs winVfs = {
-    3,                   /* iVersion */
-    sizeof(winFile),     /* szOsFile */
-    MAX_PATH,            /* mxPathname */
-    0,                   /* pNext */
-    "win32",             /* zName */
-    0,                   /* pAppData */
-    winOpen,             /* xOpen */
-    winDelete,           /* xDelete */
-    winAccess,           /* xAccess */
-    winFullPathname,     /* xFullPathname */
-    winDlOpen,           /* xDlOpen */
-    winDlError,          /* xDlError */
-    winDlSym,            /* xDlSym */
-    winDlClose,          /* xDlClose */
-    winRandomness,       /* xRandomness */
-    winSleep,            /* xSleep */
-    winCurrentTime,      /* xCurrentTime */
-    winGetLastError,     /* xGetLastError */
-    winCurrentTimeInt64, /* xCurrentTimeInt64 */
-    0,                   /* xSetSystemCall */
-    0,                   /* xGetSystemCall */
-    0,                   /* xNextSystemCall */
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32",               /* zName */
+    &winAppData,           /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
+  };
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  static sqlite3_vfs winLongPathVfs = {
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32-longpath",      /* zName */
+    &winAppData,           /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
+  };
+#endif
+  static sqlite3_vfs winNolockVfs = {
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32-none",          /* zName */
+    &winNolockAppData,     /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
   };
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  static sqlite3_vfs winLongPathNolockVfs = {
+    3,                     /* iVersion */
+    sizeof(winFile),       /* szOsFile */
+    SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
+    0,                     /* pNext */
+    "win32-longpath-none", /* zName */
+    &winNolockAppData,     /* pAppData */
+    winOpen,               /* xOpen */
+    winDelete,             /* xDelete */
+    winAccess,             /* xAccess */
+    winFullPathname,       /* xFullPathname */
+    winDlOpen,             /* xDlOpen */
+    winDlError,            /* xDlError */
+    winDlSym,              /* xDlSym */
+    winDlClose,            /* xDlClose */
+    winRandomness,         /* xRandomness */
+    winSleep,              /* xSleep */
+    winCurrentTime,        /* xCurrentTime */
+    winGetLastError,       /* xGetLastError */
+    winCurrentTimeInt64,   /* xCurrentTimeInt64 */
+    winSetSystemCall,      /* xSetSystemCall */
+    winGetSystemCall,      /* xGetSystemCall */
+    winNextSystemCall,     /* xNextSystemCall */
+  };
+#endif
+
+  /* Double-check that the aSyscall[] array has been constructed
+  ** correctly.  See ticket [bb3a86e890c8e96ab] */
+  assert( ArraySize(aSyscall)==80 );
 
-#ifndef SQLITE_OMIT_WAL
   /* get memory map allocation granularity */
   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
-  GetSystemInfo(&winSysInfo);
-  assert(winSysInfo.dwAllocationGranularity > 0);
+#if SQLITE_OS_WINRT
+  osGetNativeSystemInfo(&winSysInfo);
+#else
+  osGetSystemInfo(&winSysInfo);
 #endif
+  assert( winSysInfo.dwAllocationGranularity>0 );
+  assert( winSysInfo.dwPageSize>0 );
 
   sqlite3_vfs_register(&winVfs, 1);
-  return SQLITE_OK; 
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  sqlite3_vfs_register(&winLongPathVfs, 0);
+#endif
+
+  sqlite3_vfs_register(&winNolockVfs, 0);
+
+#if defined(SQLITE_WIN32_HAS_WIDE)
+  sqlite3_vfs_register(&winLongPathNolockVfs, 0);
+#endif
+
+  return SQLITE_OK;
 }
-SQLITE_API int sqlite3_os_end(void){ 
+
+SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void){
+#if SQLITE_OS_WINRT
+  if( sleepObj!=NULL ){
+    osCloseHandle(sleepObj);
+    sleepObj = NULL;
+  }
+#endif
   return SQLITE_OK;
 }
 
@@ -34829,13 +43110,15 @@ SQLITE_API int sqlite3_os_end(void){
 ** start of a transaction, and is thus usually less than a few thousand,
 ** but can be as large as 2 billion for a really big database.
 */
+/* #include "sqliteInt.h" */
 
 /* Size of the Bitvec structure in bytes. */
 #define BITVEC_SZ        512
 
 /* Round the union size down to the nearest pointer boundary, since that's how 
 ** it will be aligned within the Bitvec struct. */
-#define BITVEC_USIZE     (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))
+#define BITVEC_USIZE \
+    (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))
 
 /* Type of the array "element" for the bitmap representation. 
 ** Should be a power of 2, and ideally, evenly divide into BITVEC_USIZE. 
@@ -34866,7 +43149,7 @@ SQLITE_API int sqlite3_os_end(void){
 /*
 ** A bitmap is an instance of the following structure.
 **
-** This bitmap records the existance of zero or more bits
+** This bitmap records the existence of zero or more bits
 ** with values between 1 and iSize, inclusive.
 **
 ** There are three possible representations of the bitmap.
@@ -34920,10 +43203,10 @@ SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32 iSize){
 ** If p is NULL (if the bitmap has not been created) or if
 ** i is out of range, then return false.
 */
-SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
-  if( p==0 ) return 0;
-  if( i>p->iSize || i==0 ) return 0;
+SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec *p, u32 i){
+  assert( p!=0 );
   i--;
+  if( i>=p->iSize ) return 0;
   while( p->iDivisor ){
     u32 bin = i/p->iDivisor;
     i = i%p->iDivisor;
@@ -34943,6 +43226,9 @@ SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
     return 0;
   }
 }
+SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){
+  return p!=0 && sqlite3BitvecTestNotNull(p,i);
+}
 
 /*
 ** Set the i-th bit.  Return 0 on success and an error code if
@@ -34967,7 +43253,7 @@ SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec *p, u32 i){
     i = i%p->iDivisor;
     if( p->u.apSub[bin]==0 ){
       p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
-      if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
+      if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM_BKPT;
     }
     p = p->u.apSub[bin];
   }
@@ -35002,7 +43288,7 @@ bitvec_set_rehash:
     int rc;
     u32 *aiValues = sqlite3StackAllocRaw(0, sizeof(p->u.aHash));
     if( aiValues==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }else{
       memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));
       memset(p->u.apSub, 0, sizeof(p->u.apSub));
@@ -35134,10 +43420,9 @@ SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int sz, int *aOp){
   /* Allocate the Bitvec to be tested and a linear array of
   ** bits to act as the reference */
   pBitvec = sqlite3BitvecCreate( sz );
-  pV = sqlite3_malloc( (sz+7)/8 + 1 );
-  pTmpSpace = sqlite3_malloc(BITVEC_SZ);
+  pV = sqlite3MallocZero( (sz+7)/8 + 1 );
+  pTmpSpace = sqlite3_malloc64(BITVEC_SZ);
   if( pBitvec==0 || pV==0 || pTmpSpace==0  ) goto bitvec_end;
-  memset(pV, 0, (sz+7)/8 + 1);
 
   /* NULL pBitvec tests */
   sqlite3BitvecSet(0, 1);
@@ -35216,113 +43501,217 @@ bitvec_end:
 *************************************************************************
 ** This file implements that page cache.
 */
+/* #include "sqliteInt.h" */
 
 /*
-** A complete page cache is an instance of this structure.
+** A complete page cache is an instance of this structure.  Every
+** entry in the cache holds a single page of the database file.  The
+** btree layer only operates on the cached copy of the database pages.
+**
+** A page cache entry is "clean" if it exactly matches what is currently
+** on disk.  A page is "dirty" if it has been modified and needs to be
+** persisted to disk.
+**
+** pDirty, pDirtyTail, pSynced:
+**   All dirty pages are linked into the doubly linked list using
+**   PgHdr.pDirtyNext and pDirtyPrev. The list is maintained in LRU order
+**   such that p was added to the list more recently than p->pDirtyNext.
+**   PCache.pDirty points to the first (newest) element in the list and
+**   pDirtyTail to the last (oldest).
+**
+**   The PCache.pSynced variable is used to optimize searching for a dirty
+**   page to eject from the cache mid-transaction. It is better to eject
+**   a page that does not require a journal sync than one that does. 
+**   Therefore, pSynced is maintained to that it *almost* always points
+**   to either the oldest page in the pDirty/pDirtyTail list that has a
+**   clear PGHDR_NEED_SYNC flag or to a page that is older than this one
+**   (so that the right page to eject can be found by following pDirtyPrev
+**   pointers).
 */
 struct PCache {
   PgHdr *pDirty, *pDirtyTail;         /* List of dirty pages in LRU order */
   PgHdr *pSynced;                     /* Last synced page in dirty page list */
-  int nRef;                           /* Number of referenced pages */
-  int nMax;                           /* Configured cache size */
+  int nRefSum;                        /* Sum of ref counts over all pages */
+  int szCache;                        /* Configured cache size */
+  int szSpill;                        /* Size before spilling occurs */
   int szPage;                         /* Size of every page in this cache */
   int szExtra;                        /* Size of extra space for each page */
-  int bPurgeable;                     /* True if pages are on backing store */
+  u8 bPurgeable;                      /* True if pages are on backing store */
+  u8 eCreate;                         /* eCreate value for for xFetch() */
   int (*xStress)(void*,PgHdr*);       /* Call to try make a page clean */
   void *pStress;                      /* Argument to xStress */
   sqlite3_pcache *pCache;             /* Pluggable cache module */
-  PgHdr *pPage1;                      /* Reference to page 1 */
 };
 
+/********************************** Test and Debug Logic **********************/
 /*
-** Some of the assert() macros in this code are too expensive to run
-** even during normal debugging.  Use them only rarely on long-running
-** tests.  Enable the expensive asserts using the
-** -DSQLITE_ENABLE_EXPENSIVE_ASSERT=1 compile-time option.
+** Debug tracing macros.  Enable by by changing the "0" to "1" and
+** recompiling.
+**
+** When sqlite3PcacheTrace is 1, single line trace messages are issued.
+** When sqlite3PcacheTrace is 2, a dump of the pcache showing all cache entries
+** is displayed for many operations, resulting in a lot of output.
 */
-#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
-# define expensive_assert(X)  assert(X)
-#else
-# define expensive_assert(X)
+#if defined(SQLITE_DEBUG) && 0
+  int sqlite3PcacheTrace = 2;       /* 0: off  1: simple  2: cache dumps */
+  int sqlite3PcacheMxDump = 9999;   /* Max cache entries for pcacheDump() */
+# define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;}
+  void pcacheDump(PCache *pCache){
+    int N;
+    int i, j;
+    sqlite3_pcache_page *pLower;
+    PgHdr *pPg;
+    unsigned char *a;
+  
+    if( sqlite3PcacheTrace<2 ) return;
+    if( pCache->pCache==0 ) return;
+    N = sqlite3PcachePagecount(pCache);
+    if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump;
+    for(i=1; i<=N; i++){
+       pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0);
+       if( pLower==0 ) continue;
+       pPg = (PgHdr*)pLower->pExtra;
+       printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
+       a = (unsigned char *)pLower->pBuf;
+       for(j=0; j<12; j++) printf("%02x", a[j]);
+       printf("\n");
+       if( pPg->pPage==0 ){
+         sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0);
+       }
+    }
+  }
+  #else
+# define pcacheTrace(X)
+# define pcacheDump(X)
 #endif
 
-/********************************** Linked List Management ********************/
-
-#if !defined(NDEBUG) && defined(SQLITE_ENABLE_EXPENSIVE_ASSERT)
 /*
-** Check that the pCache->pSynced variable is set correctly. If it
-** is not, either fail an assert or return zero. Otherwise, return
-** non-zero. This is only used in debugging builds, as follows:
+** Check invariants on a PgHdr entry.  Return true if everything is OK.
+** Return false if any invariant is violated.
+**
+** This routine is for use inside of assert() statements only.  For
+** example:
 **
-**   expensive_assert( pcacheCheckSynced(pCache) );
+**          assert( sqlite3PcachePageSanity(pPg) );
 */
-static int pcacheCheckSynced(PCache *pCache){
-  PgHdr *p;
-  for(p=pCache->pDirtyTail; p!=pCache->pSynced; p=p->pDirtyPrev){
-    assert( p->nRef || (p->flags&PGHDR_NEED_SYNC) );
-  }
-  return (p==0 || p->nRef || (p->flags&PGHDR_NEED_SYNC)==0);
+#if SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr *pPg){
+  PCache *pCache;
+  assert( pPg!=0 );
+  assert( pPg->pgno>0 );    /* Page number is 1 or more */
+  pCache = pPg->pCache;
+  assert( pCache!=0 );      /* Every page has an associated PCache */
+  if( pPg->flags & PGHDR_CLEAN ){
+    assert( (pPg->flags & PGHDR_DIRTY)==0 );/* Cannot be both CLEAN and DIRTY */
+    assert( pCache->pDirty!=pPg );          /* CLEAN pages not on dirty list */
+    assert( pCache->pDirtyTail!=pPg );
+  }
+  /* WRITEABLE pages must also be DIRTY */
+  if( pPg->flags & PGHDR_WRITEABLE ){
+    assert( pPg->flags & PGHDR_DIRTY );     /* WRITEABLE implies DIRTY */
+  }
+  /* NEED_SYNC can be set independently of WRITEABLE.  This can happen,
+  ** for example, when using the sqlite3PagerDontWrite() optimization:
+  **    (1)  Page X is journalled, and gets WRITEABLE and NEED_SEEK.
+  **    (2)  Page X moved to freelist, WRITEABLE is cleared
+  **    (3)  Page X reused, WRITEABLE is set again
+  ** If NEED_SYNC had been cleared in step 2, then it would not be reset
+  ** in step 3, and page might be written into the database without first
+  ** syncing the rollback journal, which might cause corruption on a power
+  ** loss.
+  **
+  ** Another example is when the database page size is smaller than the
+  ** disk sector size.  When any page of a sector is journalled, all pages
+  ** in that sector are marked NEED_SYNC even if they are still CLEAN, just
+  ** in case they are later modified, since all pages in the same sector
+  ** must be journalled and synced before any of those pages can be safely
+  ** written.
+  */
+  return 1;
 }
-#endif /* !NDEBUG && SQLITE_ENABLE_EXPENSIVE_ASSERT */
-
-/*
-** Remove page pPage from the list of dirty pages.
-*/
-static void pcacheRemoveFromDirtyList(PgHdr *pPage){
-  PCache *p = pPage->pCache;
-
-  assert( pPage->pDirtyNext || pPage==p->pDirtyTail );
-  assert( pPage->pDirtyPrev || pPage==p->pDirty );
+#endif /* SQLITE_DEBUG */
 
-  /* Update the PCache1.pSynced variable if necessary. */
-  if( p->pSynced==pPage ){
-    PgHdr *pSynced = pPage->pDirtyPrev;
-    while( pSynced && (pSynced->flags&PGHDR_NEED_SYNC) ){
-      pSynced = pSynced->pDirtyPrev;
-    }
-    p->pSynced = pSynced;
-  }
 
-  if( pPage->pDirtyNext ){
-    pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev;
-  }else{
-    assert( pPage==p->pDirtyTail );
-    p->pDirtyTail = pPage->pDirtyPrev;
-  }
-  if( pPage->pDirtyPrev ){
-    pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;
-  }else{
-    assert( pPage==p->pDirty );
-    p->pDirty = pPage->pDirtyNext;
-  }
-  pPage->pDirtyNext = 0;
-  pPage->pDirtyPrev = 0;
+/********************************** Linked List Management ********************/
 
-  expensive_assert( pcacheCheckSynced(p) );
-}
+/* Allowed values for second argument to pcacheManageDirtyList() */
+#define PCACHE_DIRTYLIST_REMOVE   1    /* Remove pPage from dirty list */
+#define PCACHE_DIRTYLIST_ADD      2    /* Add pPage to the dirty list */
+#define PCACHE_DIRTYLIST_FRONT    3    /* Move pPage to the front of the list */
 
 /*
-** Add page pPage to the head of the dirty list (PCache1.pDirty is set to
-** pPage).
+** Manage pPage's participation on the dirty list.  Bits of the addRemove
+** argument determines what operation to do.  The 0x01 bit means first
+** remove pPage from the dirty list.  The 0x02 means add pPage back to
+** the dirty list.  Doing both moves pPage to the front of the dirty list.
 */
-static void pcacheAddToDirtyList(PgHdr *pPage){
+static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
   PCache *p = pPage->pCache;
 
-  assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage );
+  pcacheTrace(("%p.DIRTYLIST.%s %d\n", p,
+                addRemove==1 ? "REMOVE" : addRemove==2 ? "ADD" : "FRONT",
+                pPage->pgno));
+  if( addRemove & PCACHE_DIRTYLIST_REMOVE ){
+    assert( pPage->pDirtyNext || pPage==p->pDirtyTail );
+    assert( pPage->pDirtyPrev || pPage==p->pDirty );
+  
+    /* Update the PCache1.pSynced variable if necessary. */
+    if( p->pSynced==pPage ){
+      p->pSynced = pPage->pDirtyPrev;
+    }
+  
+    if( pPage->pDirtyNext ){
+      pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev;
+    }else{
+      assert( pPage==p->pDirtyTail );
+      p->pDirtyTail = pPage->pDirtyPrev;
+    }
+    if( pPage->pDirtyPrev ){
+      pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;
+    }else{
+      /* If there are now no dirty pages in the cache, set eCreate to 2. 
+      ** This is an optimization that allows sqlite3PcacheFetch() to skip
+      ** searching for a dirty page to eject from the cache when it might
+      ** otherwise have to.  */
+      assert( pPage==p->pDirty );
+      p->pDirty = pPage->pDirtyNext;
+      assert( p->bPurgeable || p->eCreate==2 );
+      if( p->pDirty==0 ){         /*OPTIMIZATION-IF-TRUE*/
+        assert( p->bPurgeable==0 || p->eCreate==1 );
+        p->eCreate = 2;
+      }
+    }
+    pPage->pDirtyNext = 0;
+    pPage->pDirtyPrev = 0;
+  }
+  if( addRemove & PCACHE_DIRTYLIST_ADD ){
+    assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage );
+  
+    pPage->pDirtyNext = p->pDirty;
+    if( pPage->pDirtyNext ){
+      assert( pPage->pDirtyNext->pDirtyPrev==0 );
+      pPage->pDirtyNext->pDirtyPrev = pPage;
+    }else{
+      p->pDirtyTail = pPage;
+      if( p->bPurgeable ){
+        assert( p->eCreate==2 );
+        p->eCreate = 1;
+      }
+    }
+    p->pDirty = pPage;
 
-  pPage->pDirtyNext = p->pDirty;
-  if( pPage->pDirtyNext ){
-    assert( pPage->pDirtyNext->pDirtyPrev==0 );
-    pPage->pDirtyNext->pDirtyPrev = pPage;
-  }
-  p->pDirty = pPage;
-  if( !p->pDirtyTail ){
-    p->pDirtyTail = pPage;
-  }
-  if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
-    p->pSynced = pPage;
+    /* If pSynced is NULL and this page has a clear NEED_SYNC flag, set
+    ** pSynced to point to it. Checking the NEED_SYNC flag is an 
+    ** optimization, as if pSynced points to a page with the NEED_SYNC
+    ** flag set sqlite3PcacheFetchStress() searches through all newer 
+    ** entries of the dirty-list for a page with NEED_SYNC clear anyway.  */
+    if( !p->pSynced 
+     && 0==(pPage->flags&PGHDR_NEED_SYNC)   /*OPTIMIZATION-IF-FALSE*/
+    ){
+      p->pSynced = pPage;
+    }
   }
-  expensive_assert( pcacheCheckSynced(p) );
+  pcacheDump(p);
 }
 
 /*
@@ -35330,12 +43719,27 @@ static void pcacheAddToDirtyList(PgHdr *pPage){
 ** being used for an in-memory database, this function is a no-op.
 */
 static void pcacheUnpin(PgHdr *p){
-  PCache *pCache = p->pCache;
-  if( pCache->bPurgeable ){
-    if( p->pgno==1 ){
-      pCache->pPage1 = 0;
-    }
-    sqlite3GlobalConfig.pcache.xUnpin(pCache->pCache, p, 0);
+  if( p->pCache->bPurgeable ){
+    pcacheTrace(("%p.UNPIN %d\n", p->pCache, p->pgno));
+    sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 0);
+    pcacheDump(p->pCache);
+  }
+}
+
+/*
+** Compute the number of pages of cache requested.   p->szCache is the
+** cache size requested by the "PRAGMA cache_size" statement.
+*/
+static int numberOfCachePages(PCache *p){
+  if( p->szCache>=0 ){
+    /* IMPLEMENTATION-OF: R-42059-47211 If the argument N is positive then the
+    ** suggested cache size is set to N. */
+    return p->szCache;
+  }else{
+    /* IMPLEMENTATION-OF: R-61436-13639 If the argument N is negative, then
+    ** the number of cache pages is adjusted to use approximately abs(N*1024)
+    ** bytes of memory. */
+    return (int)((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));
   }
 }
 
@@ -35345,18 +43749,18 @@ static void pcacheUnpin(PgHdr *p){
 ** functions are threadsafe.
 */
 SQLITE_PRIVATE int sqlite3PcacheInitialize(void){
-  if( sqlite3GlobalConfig.pcache.xInit==0 ){
+  if( sqlite3GlobalConfig.pcache2.xInit==0 ){
     /* IMPLEMENTATION-OF: R-26801-64137 If the xInit() method is NULL, then the
     ** built-in default page cache is used instead of the application defined
     ** page cache. */
     sqlite3PCacheSetDefault();
   }
-  return sqlite3GlobalConfig.pcache.xInit(sqlite3GlobalConfig.pcache.pArg);
+  return sqlite3GlobalConfig.pcache2.xInit(sqlite3GlobalConfig.pcache2.pArg);
 }
 SQLITE_PRIVATE void sqlite3PcacheShutdown(void){
-  if( sqlite3GlobalConfig.pcache.xShutdown ){
+  if( sqlite3GlobalConfig.pcache2.xShutdown ){
     /* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */
-    sqlite3GlobalConfig.pcache.xShutdown(sqlite3GlobalConfig.pcache.pArg);
+    sqlite3GlobalConfig.pcache2.xShutdown(sqlite3GlobalConfig.pcache2.pArg);
   }
 }
 
@@ -35371,7 +43775,7 @@ SQLITE_PRIVATE int sqlite3PcacheSize(void){ return sizeof(PCache); }
 ** The caller discovers how much space needs to be allocated by 
 ** calling sqlite3PcacheSize().
 */
-SQLITE_PRIVATE void sqlite3PcacheOpen(
+SQLITE_PRIVATE int sqlite3PcacheOpen(
   int szPage,                  /* Size of every page */
   int szExtra,                 /* Extra space associated with each page */
   int bPurgeable,              /* True if pages are on backing store */
@@ -35380,73 +43784,126 @@ SQLITE_PRIVATE void sqlite3PcacheOpen(
   PCache *p                    /* Preallocated space for the PCache */
 ){
   memset(p, 0, sizeof(PCache));
-  p->szPage = szPage;
+  p->szPage = 1;
   p->szExtra = szExtra;
   p->bPurgeable = bPurgeable;
+  p->eCreate = 2;
   p->xStress = xStress;
   p->pStress = pStress;
-  p->nMax = 100;
+  p->szCache = 100;
+  p->szSpill = 1;
+  pcacheTrace(("%p.OPEN szPage %d bPurgeable %d\n",p,szPage,bPurgeable));
+  return sqlite3PcacheSetPageSize(p, szPage);
 }
 
 /*
 ** Change the page size for PCache object. The caller must ensure that there
 ** are no outstanding page references when this function is called.
 */
-SQLITE_PRIVATE void sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
-  assert( pCache->nRef==0 && pCache->pDirty==0 );
-  if( pCache->pCache ){
-    sqlite3GlobalConfig.pcache.xDestroy(pCache->pCache);
-    pCache->pCache = 0;
-    pCache->pPage1 = 0;
+SQLITE_PRIVATE int sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
+  assert( pCache->nRefSum==0 && pCache->pDirty==0 );
+  if( pCache->szPage ){
+    sqlite3_pcache *pNew;
+    pNew = sqlite3GlobalConfig.pcache2.xCreate(
+                szPage, pCache->szExtra + ROUND8(sizeof(PgHdr)),
+                pCache->bPurgeable
+    );
+    if( pNew==0 ) return SQLITE_NOMEM_BKPT;
+    sqlite3GlobalConfig.pcache2.xCachesize(pNew, numberOfCachePages(pCache));
+    if( pCache->pCache ){
+      sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
+    }
+    pCache->pCache = pNew;
+    pCache->szPage = szPage;
+    pcacheTrace(("%p.PAGESIZE %d\n",pCache,szPage));
   }
-  pCache->szPage = szPage;
+  return SQLITE_OK;
 }
 
 /*
 ** Try to obtain a page from the cache.
+**
+** This routine returns a pointer to an sqlite3_pcache_page object if
+** such an object is already in cache, or if a new one is created.
+** This routine returns a NULL pointer if the object was not in cache
+** and could not be created.
+**
+** The createFlags should be 0 to check for existing pages and should
+** be 3 (not 1, but 3) to try to create a new page.
+**
+** If the createFlag is 0, then NULL is always returned if the page
+** is not already in the cache.  If createFlag is 1, then a new page
+** is created only if that can be done without spilling dirty pages
+** and without exceeding the cache size limit.
+**
+** The caller needs to invoke sqlite3PcacheFetchFinish() to properly
+** initialize the sqlite3_pcache_page object and convert it into a
+** PgHdr object.  The sqlite3PcacheFetch() and sqlite3PcacheFetchFinish()
+** routines are split this way for performance reasons. When separated
+** they can both (usually) operate without having to push values to
+** the stack on entry and pop them back off on exit, which saves a
+** lot of pushing and popping.
 */
-SQLITE_PRIVATE int sqlite3PcacheFetch(
+SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(
   PCache *pCache,       /* Obtain the page from this cache */
   Pgno pgno,            /* Page number to obtain */
-  int createFlag,       /* If true, create page if it does not exist already */
-  PgHdr **ppPage        /* Write the page here */
+  int createFlag        /* If true, create page if it does not exist already */
 ){
-  PgHdr *pPage = 0;
   int eCreate;
+  sqlite3_pcache_page *pRes;
 
   assert( pCache!=0 );
-  assert( createFlag==1 || createFlag==0 );
+  assert( pCache->pCache!=0 );
+  assert( createFlag==3 || createFlag==0 );
   assert( pgno>0 );
+  assert( pCache->eCreate==((pCache->bPurgeable && pCache->pDirty) ? 1 : 2) );
 
-  /* If the pluggable cache (sqlite3_pcache*) has not been allocated,
-  ** allocate it now.
+  /* eCreate defines what to do if the page does not exist.
+  **    0     Do not allocate a new page.  (createFlag==0)
+  **    1     Allocate a new page if doing so is inexpensive.
+  **          (createFlag==1 AND bPurgeable AND pDirty)
+  **    2     Allocate a new page even it doing so is difficult.
+  **          (createFlag==1 AND !(bPurgeable AND pDirty)
   */
-  if( !pCache->pCache && createFlag ){
-    sqlite3_pcache *p;
-    int nByte;
-    nByte = pCache->szPage + pCache->szExtra + sizeof(PgHdr);
-    p = sqlite3GlobalConfig.pcache.xCreate(nByte, pCache->bPurgeable);
-    if( !p ){
-      return SQLITE_NOMEM;
-    }
-    sqlite3GlobalConfig.pcache.xCachesize(p, pCache->nMax);
-    pCache->pCache = p;
-  }
-
-  eCreate = createFlag * (1 + (!pCache->bPurgeable || !pCache->pDirty));
-  if( pCache->pCache ){
-    pPage = sqlite3GlobalConfig.pcache.xFetch(pCache->pCache, pgno, eCreate);
-  }
+  eCreate = createFlag & pCache->eCreate;
+  assert( eCreate==0 || eCreate==1 || eCreate==2 );
+  assert( createFlag==0 || pCache->eCreate==eCreate );
+  assert( createFlag==0 || eCreate==1+(!pCache->bPurgeable||!pCache->pDirty) );
+  pRes = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);
+  pcacheTrace(("%p.FETCH %d%s (result: %p)\n",pCache,pgno,
+               createFlag?" create":"",pRes));
+  return pRes;
+}
 
-  if( !pPage && eCreate==1 ){
-    PgHdr *pPg;
+/*
+** If the sqlite3PcacheFetch() routine is unable to allocate a new
+** page because no clean pages are available for reuse and the cache
+** size limit has been reached, then this routine can be invoked to 
+** try harder to allocate a page.  This routine might invoke the stress
+** callback to spill dirty pages to the journal.  It will then try to
+** allocate the new page and will only fail to allocate a new page on
+** an OOM error.
+**
+** This routine should be invoked only after sqlite3PcacheFetch() fails.
+*/
+SQLITE_PRIVATE int sqlite3PcacheFetchStress(
+  PCache *pCache,                 /* Obtain the page from this cache */
+  Pgno pgno,                      /* Page number to obtain */
+  sqlite3_pcache_page **ppPage    /* Write result here */
+){
+  PgHdr *pPg;
+  if( pCache->eCreate==2 ) return 0;
 
+  if( sqlite3PcachePagecount(pCache)>pCache->szSpill ){
     /* Find a dirty page to write-out and recycle. First try to find a 
     ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
     ** cleared), but if that is not possible settle for any other 
     ** unreferenced dirty page.
-    */
-    expensive_assert( pcacheCheckSynced(pCache) );
+    **
+    ** If the LRU page in the dirty list that has a clear PGHDR_NEED_SYNC
+    ** flag is currently referenced, then the following may leave pSynced
+    ** set incorrectly (pointing to other than the LRU page with NEED_SYNC
+    ** cleared). This is Ok, as pSynced is just an optimization.  */
     for(pPg=pCache->pSynced; 
         pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
         pPg=pPg->pDirtyPrev
@@ -35462,59 +43919,90 @@ SQLITE_PRIVATE int sqlite3PcacheFetch(
                   "spill page %d making room for %d - cache used: %d/%d",
                   pPg->pgno, pgno,
                   sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
-                  pCache->nMax);
+                numberOfCachePages(pCache));
 #endif
+      pcacheTrace(("%p.SPILL %d\n",pCache,pPg->pgno));
       rc = pCache->xStress(pCache->pStress, pPg);
+      pcacheDump(pCache);
       if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
         return rc;
       }
     }
-
-    pPage = sqlite3GlobalConfig.pcache.xFetch(pCache->pCache, pgno, 2);
   }
+  *ppPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2);
+  return *ppPage==0 ? SQLITE_NOMEM_BKPT : SQLITE_OK;
+}
 
-  if( pPage ){
-    if( !pPage->pData ){
-      memset(pPage, 0, sizeof(PgHdr));
-      pPage->pData = (void *)&pPage[1];
-      pPage->pExtra = (void*)&((char *)pPage->pData)[pCache->szPage];
-      memset(pPage->pExtra, 0, pCache->szExtra);
-      pPage->pCache = pCache;
-      pPage->pgno = pgno;
-    }
-    assert( pPage->pCache==pCache );
-    assert( pPage->pgno==pgno );
-    assert( pPage->pData==(void *)&pPage[1] );
-    assert( pPage->pExtra==(void *)&((char *)&pPage[1])[pCache->szPage] );
-
-    if( 0==pPage->nRef ){
-      pCache->nRef++;
-    }
-    pPage->nRef++;
-    if( pgno==1 ){
-      pCache->pPage1 = pPage;
-    }
+/*
+** This is a helper routine for sqlite3PcacheFetchFinish()
+**
+** In the uncommon case where the page being fetched has not been
+** initialized, this routine is invoked to do the initialization.
+** This routine is broken out into a separate function since it
+** requires extra stack manipulation that can be avoided in the common
+** case.
+*/
+static SQLITE_NOINLINE PgHdr *pcacheFetchFinishWithInit(
+  PCache *pCache,             /* Obtain the page from this cache */
+  Pgno pgno,                  /* Page number obtained */
+  sqlite3_pcache_page *pPage  /* Page obtained by prior PcacheFetch() call */
+){
+  PgHdr *pPgHdr;
+  assert( pPage!=0 );
+  pPgHdr = (PgHdr*)pPage->pExtra;
+  assert( pPgHdr->pPage==0 );
+  memset(pPgHdr, 0, sizeof(PgHdr));
+  pPgHdr->pPage = pPage;
+  pPgHdr->pData = pPage->pBuf;
+  pPgHdr->pExtra = (void *)&pPgHdr[1];
+  memset(pPgHdr->pExtra, 0, pCache->szExtra);
+  pPgHdr->pCache = pCache;
+  pPgHdr->pgno = pgno;
+  pPgHdr->flags = PGHDR_CLEAN;
+  return sqlite3PcacheFetchFinish(pCache,pgno,pPage);
+}
+
+/*
+** This routine converts the sqlite3_pcache_page object returned by
+** sqlite3PcacheFetch() into an initialized PgHdr object.  This routine
+** must be called after sqlite3PcacheFetch() in order to get a usable
+** result.
+*/
+SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(
+  PCache *pCache,             /* Obtain the page from this cache */
+  Pgno pgno,                  /* Page number obtained */
+  sqlite3_pcache_page *pPage  /* Page obtained by prior PcacheFetch() call */
+){
+  PgHdr *pPgHdr;
+
+  assert( pPage!=0 );
+  pPgHdr = (PgHdr *)pPage->pExtra;
+
+  if( !pPgHdr->pPage ){
+    return pcacheFetchFinishWithInit(pCache, pgno, pPage);
   }
-  *ppPage = pPage;
-  return (pPage==0 && eCreate) ? SQLITE_NOMEM : SQLITE_OK;
+  pCache->nRefSum++;
+  pPgHdr->nRef++;
+  assert( sqlite3PcachePageSanity(pPgHdr) );
+  return pPgHdr;
 }
 
 /*
 ** Decrement the reference count on a page. If the page is clean and the
-** reference count drops to 0, then it is made elible for recycling.
+** reference count drops to 0, then it is made eligible for recycling.
 */
-SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr *p){
+SQLITE_PRIVATE void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
   assert( p->nRef>0 );
-  p->nRef--;
-  if( p->nRef==0 ){
-    PCache *pCache = p->pCache;
-    pCache->nRef--;
-    if( (p->flags&PGHDR_DIRTY)==0 ){
+  p->pCache->nRefSum--;
+  if( (--p->nRef)==0 ){
+    if( p->flags&PGHDR_CLEAN ){
       pcacheUnpin(p);
-    }else{
-      /* Move the page to the head of the dirty list. */
-      pcacheRemoveFromDirtyList(p);
-      pcacheAddToDirtyList(p);
+    }else if( p->pDirtyPrev!=0 ){ /*OPTIMIZATION-IF-FALSE*/
+      /* Move the page to the head of the dirty list. If p->pDirtyPrev==0,
+      ** then page p is already at the head of the dirty list and the
+      ** following call would be a no-op. Hence the OPTIMIZATION-IF-FALSE
+      ** tag above.  */
+      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
     }
   }
 }
@@ -35524,7 +44012,9 @@ SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr *p){
 */
 SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr *p){
   assert(p->nRef>0);
+  assert( sqlite3PcachePageSanity(p) );
   p->nRef++;
+  p->pCache->nRefSum++;
 }
 
 /*
@@ -35533,17 +44023,13 @@ SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr *p){
 ** page pointed to by p is invalid.
 */
 SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr *p){
-  PCache *pCache;
   assert( p->nRef==1 );
+  assert( sqlite3PcachePageSanity(p) );
   if( p->flags&PGHDR_DIRTY ){
-    pcacheRemoveFromDirtyList(p);
-  }
-  pCache = p->pCache;
-  pCache->nRef--;
-  if( p->pgno==1 ){
-    pCache->pPage1 = 0;
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
   }
-  sqlite3GlobalConfig.pcache.xUnpin(pCache->pCache, p, 1);
+  p->pCache->nRefSum--;
+  sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1);
 }
 
 /*
@@ -35551,11 +44037,17 @@ SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr *p){
 ** make it so.
 */
 SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr *p){
-  p->flags &= ~PGHDR_DONT_WRITE;
   assert( p->nRef>0 );
-  if( 0==(p->flags & PGHDR_DIRTY) ){
-    p->flags |= PGHDR_DIRTY;
-    pcacheAddToDirtyList( p);
+  assert( sqlite3PcachePageSanity(p) );
+  if( p->flags & (PGHDR_CLEAN|PGHDR_DONT_WRITE) ){    /*OPTIMIZATION-IF-FALSE*/
+    p->flags &= ~PGHDR_DONT_WRITE;
+    if( p->flags & PGHDR_CLEAN ){
+      p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN);
+      pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno));
+      assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY );
+      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);
+    }
+    assert( sqlite3PcachePageSanity(p) );
   }
 }
 
@@ -35564,9 +44056,14 @@ SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr *p){
 ** make it so.
 */
 SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr *p){
-  if( (p->flags & PGHDR_DIRTY) ){
-    pcacheRemoveFromDirtyList(p);
-    p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC);
+  assert( sqlite3PcachePageSanity(p) );
+  if( ALWAYS((p->flags & PGHDR_DIRTY)!=0) ){
+    assert( (p->flags & PGHDR_CLEAN)==0 );
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
+    p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
+    p->flags |= PGHDR_CLEAN;
+    pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno));
+    assert( sqlite3PcachePageSanity(p) );
     if( p->nRef==0 ){
       pcacheUnpin(p);
     }
@@ -35578,12 +44075,25 @@ SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr *p){
 */
 SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache *pCache){
   PgHdr *p;
+  pcacheTrace(("%p.CLEAN-ALL\n",pCache));
   while( (p = pCache->pDirty)!=0 ){
     sqlite3PcacheMakeClean(p);
   }
 }
 
 /*
+** Clear the PGHDR_NEED_SYNC and PGHDR_WRITEABLE flag from all dirty pages.
+*/
+SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache *pCache){
+  PgHdr *p;
+  pcacheTrace(("%p.CLEAR-WRITEABLE\n",pCache));
+  for(p=pCache->pDirty; p; p=p->pDirtyNext){
+    p->flags &= ~(PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
+  }
+  pCache->pSynced = pCache->pDirtyTail;
+}
+
+/*
 ** Clear the PGHDR_NEED_SYNC flag from all dirty pages.
 */
 SQLITE_PRIVATE void sqlite3PcacheClearSyncFlags(PCache *pCache){
@@ -35601,11 +44111,12 @@ SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
   PCache *pCache = p->pCache;
   assert( p->nRef>0 );
   assert( newPgno>0 );
-  sqlite3GlobalConfig.pcache.xRekey(pCache->pCache, p, p->pgno, newPgno);
+  assert( sqlite3PcachePageSanity(p) );
+  pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno));
+  sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);
   p->pgno = newPgno;
   if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){
-    pcacheRemoveFromDirtyList(p);
-    pcacheAddToDirtyList(p);
+    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
   }
 }
 
@@ -35622,6 +44133,7 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
   if( pCache->pCache ){
     PgHdr *p;
     PgHdr *pNext;
+    pcacheTrace(("%p.TRUNCATE %d\n",pCache,pgno));
     for(p=pCache->pDirty; p; p=pNext){
       pNext = p->pDirtyNext;
       /* This routine never gets call with a positive pgno except right
@@ -35629,16 +44141,21 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
       ** it must be that pgno==0.
       */
       assert( p->pgno>0 );
-      if( ALWAYS(p->pgno>pgno) ){
+      if( p->pgno>pgno ){
         assert( p->flags&PGHDR_DIRTY );
         sqlite3PcacheMakeClean(p);
       }
     }
-    if( pgno==0 && pCache->pPage1 ){
-      memset(pCache->pPage1->pData, 0, pCache->szPage);
-      pgno = 1;
+    if( pgno==0 && pCache->nRefSum ){
+      sqlite3_pcache_page *pPage1;
+      pPage1 = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache,1,0);
+      if( ALWAYS(pPage1) ){  /* Page 1 is always available in cache, because
+                             ** pCache->nRefSum>0 */
+        memset(pPage1->pBuf, 0, pCache->szPage);
+        pgno = 1;
+      }
     }
-    sqlite3GlobalConfig.pcache.xTruncate(pCache->pCache, pgno+1);
+    sqlite3GlobalConfig.pcache2.xTruncate(pCache->pCache, pgno+1);
   }
 }
 
@@ -35646,9 +44163,9 @@ SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
 ** Close a cache.
 */
 SQLITE_PRIVATE void sqlite3PcacheClose(PCache *pCache){
-  if( pCache->pCache ){
-    sqlite3GlobalConfig.pcache.xDestroy(pCache->pCache);
-  }
+  assert( pCache->pCache!=0 );
+  pcacheTrace(("%p.CLOSE\n",pCache));
+  sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
 }
 
 /* 
@@ -35660,29 +44177,31 @@ SQLITE_PRIVATE void sqlite3PcacheClear(PCache *pCache){
 
 /*
 ** Merge two lists of pages connected by pDirty and in pgno order.
-** Do not both fixing the pDirtyPrev pointers.
+** Do not bother fixing the pDirtyPrev pointers.
 */
 static PgHdr *pcacheMergeDirtyList(PgHdr *pA, PgHdr *pB){
   PgHdr result, *pTail;
   pTail = &result;
-  while( pA && pB ){
+  assert( pA!=0 && pB!=0 );
+  for(;;){
     if( pA->pgno<pB->pgno ){
       pTail->pDirty = pA;
       pTail = pA;
       pA = pA->pDirty;
+      if( pA==0 ){
+        pTail->pDirty = pB;
+        break;
+      }
     }else{
       pTail->pDirty = pB;
       pTail = pB;
       pB = pB->pDirty;
+      if( pB==0 ){
+        pTail->pDirty = pA;
+        break;
+      }
     }
   }
-  if( pA ){
-    pTail->pDirty = pA;
-  }else if( pB ){
-    pTail->pDirty = pB;
-  }else{
-    pTail->pDirty = 0;
-  }
   return result.pDirty;
 }
 
@@ -35723,7 +44242,8 @@ static PgHdr *pcacheSortDirtyList(PgHdr *pIn){
   }
   p = a[0];
   for(i=1; i<N_SORT_BUCKET; i++){
-    p = pcacheMergeDirtyList(p, a[i]);
+    if( a[i]==0 ) continue;
+    p = p ? pcacheMergeDirtyList(p, a[i]) : a[i];
   }
   return p;
 }
@@ -35740,10 +44260,13 @@ SQLITE_PRIVATE PgHdr *sqlite3PcacheDirtyList(PCache *pCache){
 }
 
 /* 
-** Return the total number of referenced pages held by the cache.
+** Return the total number of references to all pages held by the cache.
+**
+** This is not the total number of pages referenced, but the sum of the
+** reference count for all pages.
 */
 SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache *pCache){
-  return pCache->nRef;
+  return pCache->nRefSum;
 }
 
 /*
@@ -35757,11 +44280,8 @@ SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr *p){
 ** Return the total number of pages in the cache.
 */
 SQLITE_PRIVATE int sqlite3PcachePagecount(PCache *pCache){
-  int nPage = 0;
-  if( pCache->pCache ){
-    nPage = sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache);
-  }
-  return nPage;
+  assert( pCache->pCache!=0 );
+  return sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache);
 }
 
 #ifdef SQLITE_TEST
@@ -35769,7 +44289,7 @@ SQLITE_PRIVATE int sqlite3PcachePagecount(PCache *pCache){
 ** Get the suggested cache-size value.
 */
 SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *pCache){
-  return pCache->nMax;
+  return numberOfCachePages(pCache);
 }
 #endif
 
@@ -35777,10 +44297,55 @@ SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *pCache){
 ** Set the suggested cache-size value.
 */
 SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *pCache, int mxPage){
-  pCache->nMax = mxPage;
-  if( pCache->pCache ){
-    sqlite3GlobalConfig.pcache.xCachesize(pCache->pCache, mxPage);
+  assert( pCache->pCache!=0 );
+  pCache->szCache = mxPage;
+  sqlite3GlobalConfig.pcache2.xCachesize(pCache->pCache,
+                                         numberOfCachePages(pCache));
+}
+
+/*
+** Set the suggested cache-spill value.  Make no changes if if the
+** argument is zero.  Return the effective cache-spill size, which will
+** be the larger of the szSpill and szCache.
+*/
+SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *p, int mxPage){
+  int res;
+  assert( p->pCache!=0 );
+  if( mxPage ){
+    if( mxPage<0 ){
+      mxPage = (int)((-1024*(i64)mxPage)/(p->szPage+p->szExtra));
+    }
+    p->szSpill = mxPage;
   }
+  res = numberOfCachePages(p);
+  if( res<p->szSpill ) res = p->szSpill; 
+  return res;
+}
+
+/*
+** Free up as much memory as possible from the page cache.
+*/
+SQLITE_PRIVATE void sqlite3PcacheShrink(PCache *pCache){
+  assert( pCache->pCache!=0 );
+  sqlite3GlobalConfig.pcache2.xShrink(pCache->pCache);
+}
+
+/*
+** Return the size of the header added by this middleware layer
+** in the page-cache hierarchy.
+*/
+SQLITE_PRIVATE int sqlite3HeaderSizePcache(void){ return ROUND8(sizeof(PgHdr)); }
+
+/*
+** Return the number of dirty pages currently in the cache, as a percentage
+** of the configured cache size.
+*/
+SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache *pCache){
+  PgHdr *pDirty;
+  int nDirty = 0;
+  int nCache = numberOfCachePages(pCache);
+  for(pDirty=pCache->pDirty; pDirty; pDirty=pDirty->pDirtyNext) nDirty++;
+  return nCache ? (int)(((i64)nDirty * 100) / nCache) : 0;
 }
 
 #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
@@ -35814,19 +44379,100 @@ SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHd
 ** This file implements the default page cache implementation (the
 ** sqlite3_pcache interface). It also contains part of the implementation
 ** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.
-** If the default page cache implementation is overriden, then neither of
+** If the default page cache implementation is overridden, then neither of
 ** these two features are available.
+**
+** A Page cache line looks like this:
+**
+**  -------------------------------------------------------------
+**  |  database page content   |  PgHdr1  |  MemPage  |  PgHdr  |
+**  -------------------------------------------------------------
+**
+** The database page content is up front (so that buffer overreads tend to
+** flow harmlessly into the PgHdr1, MemPage, and PgHdr extensions).   MemPage
+** is the extension added by the btree.c module containing information such
+** as the database page number and how that database page is used.  PgHdr
+** is added by the pcache.c layer and contains information used to keep track
+** of which pages are "dirty".  PgHdr1 is an extension added by this
+** module (pcache1.c).  The PgHdr1 header is a subclass of sqlite3_pcache_page.
+** PgHdr1 contains information needed to look up a page by its page number.
+** The superclass sqlite3_pcache_page.pBuf points to the start of the
+** database page content and sqlite3_pcache_page.pExtra points to PgHdr.
+**
+** The size of the extension (MemPage+PgHdr+PgHdr1) can be determined at
+** runtime using sqlite3_config(SQLITE_CONFIG_PCACHE_HDRSZ, &size).  The
+** sizes of the extensions sum to 272 bytes on x64 for 3.8.10, but this
+** size can vary according to architecture, compile-time options, and
+** SQLite library version number.
+**
+** If SQLITE_PCACHE_SEPARATE_HEADER is defined, then the extension is obtained
+** using a separate memory allocation from the database page content.  This
+** seeks to overcome the "clownshoe" problem (also called "internal
+** fragmentation" in academic literature) of allocating a few bytes more
+** than a power of two with the memory allocator rounding up to the next
+** power of two, and leaving the rounded-up space unused.
+**
+** This module tracks pointers to PgHdr1 objects.  Only pcache.c communicates
+** with this module.  Information is passed back and forth as PgHdr1 pointers.
+**
+** The pcache.c and pager.c modules deal pointers to PgHdr objects.
+** The btree.c module deals with pointers to MemPage objects.
+**
+** SOURCE OF PAGE CACHE MEMORY:
+**
+** Memory for a page might come from any of three sources:
+**
+**    (1)  The general-purpose memory allocator - sqlite3Malloc()
+**    (2)  Global page-cache memory provided using sqlite3_config() with
+**         SQLITE_CONFIG_PAGECACHE.
+**    (3)  PCache-local bulk allocation.
+**
+** The third case is a chunk of heap memory (defaulting to 100 pages worth)
+** that is allocated when the page cache is created.  The size of the local
+** bulk allocation can be adjusted using 
+**
+**     sqlite3_config(SQLITE_CONFIG_PAGECACHE, (void*)0, 0, N).
+**
+** If N is positive, then N pages worth of memory are allocated using a single
+** sqlite3Malloc() call and that memory is used for the first N pages allocated.
+** Or if N is negative, then -1024*N bytes of memory are allocated and used
+** for as many pages as can be accomodated.
+**
+** Only one of (2) or (3) can be used.  Once the memory available to (2) or
+** (3) is exhausted, subsequent allocations fail over to the general-purpose
+** memory allocator (1).
+**
+** Earlier versions of SQLite used only methods (1) and (2).  But experiments
+** show that method (3) with N==100 provides about a 5% performance boost for
+** common workloads.
 */
-
+/* #include "sqliteInt.h" */
 
 typedef struct PCache1 PCache1;
 typedef struct PgHdr1 PgHdr1;
 typedef struct PgFreeslot PgFreeslot;
 typedef struct PGroup PGroup;
 
+/*
+** Each cache entry is represented by an instance of the following 
+** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
+** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
+** in memory.
+*/
+struct PgHdr1 {
+  sqlite3_pcache_page page;      /* Base class. Must be first. pBuf & pExtra */
+  unsigned int iKey;             /* Key value (page number) */
+  u8 isPinned;                   /* Page in use, not on the LRU list */
+  u8 isBulkLocal;                /* This page from bulk local storage */
+  u8 isAnchor;                   /* This is the PGroup.lru element */
+  PgHdr1 *pNext;                 /* Next in hash table chain */
+  PCache1 *pCache;               /* Cache that currently owns this page */
+  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
+  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
+};
 
 /* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
-** of one or more PCaches that are able to recycle each others unpinned
+** of one or more PCaches that are able to recycle each other's unpinned
 ** pages when they are under memory pressure.  A PGroup is an instance of
 ** the following object.
 **
@@ -35841,7 +44487,7 @@ typedef struct PGroup PGroup;
 ** Mode 1 uses more memory (since PCache instances are not able to rob
 ** unused pages from other PCaches) but it also operates without a mutex,
 ** and is therefore often faster.  Mode 2 requires a mutex in order to be
-** threadsafe, but is able recycle pages more efficient.
+** threadsafe, but recycles pages more efficiently.
 **
 ** For mode (1), PGroup.mutex is NULL.  For mode (2) there is only a single
 ** PGroup which is the pcache1.grp global variable and its mutex is
@@ -35849,11 +44495,11 @@ typedef struct PGroup PGroup;
 */
 struct PGroup {
   sqlite3_mutex *mutex;          /* MUTEX_STATIC_LRU or NULL */
-  int nMaxPage;                  /* Sum of nMax for purgeable caches */
-  int nMinPage;                  /* Sum of nMin for purgeable caches */
-  int mxPinned;                  /* nMaxpage + 10 - nMinPage */
-  int nCurrentPage;              /* Number of purgeable pages allocated */
-  PgHdr1 *pLruHead, *pLruTail;   /* LRU list of unpinned pages */
+  unsigned int nMaxPage;         /* Sum of nMax for purgeable caches */
+  unsigned int nMinPage;         /* Sum of nMin for purgeable caches */
+  unsigned int mxPinned;         /* nMaxpage + 10 - nMinPage */
+  unsigned int nCurrentPage;     /* Number of purgeable pages allocated */
+  PgHdr1 lru;                    /* The beginning and end of the LRU list */
 };
 
 /* Each page cache is an instance of the following object.  Every
@@ -35867,15 +44513,18 @@ struct PGroup {
 struct PCache1 {
   /* Cache configuration parameters. Page size (szPage) and the purgeable
   ** flag (bPurgeable) are set when the cache is created. nMax may be 
-  ** modified at any time by a call to the pcache1CacheSize() method.
+  ** modified at any time by a call to the pcache1Cachesize() method.
   ** The PGroup mutex must be held when accessing nMax.
   */
   PGroup *pGroup;                     /* PGroup this cache belongs to */
-  int szPage;                         /* Size of allocated pages in bytes */
+  int szPage;                         /* Size of database content section */
+  int szExtra;                        /* sizeof(MemPage)+sizeof(PgHdr) */
+  int szAlloc;                        /* Total size of one pcache line */
   int bPurgeable;                     /* True if cache is purgeable */
   unsigned int nMin;                  /* Minimum number of pages reserved */
   unsigned int nMax;                  /* Configured "cache_size" value */
   unsigned int n90pct;                /* nMax*9/10 */
+  unsigned int iMaxKey;               /* Largest key seen since xTruncate() */
 
   /* Hash table of all pages. The following variables may only be accessed
   ** when the accessor is holding the PGroup mutex.
@@ -35884,27 +44533,13 @@ struct PCache1 {
   unsigned int nPage;                 /* Total number of pages in apHash */
   unsigned int nHash;                 /* Number of slots in apHash[] */
   PgHdr1 **apHash;                    /* Hash table for fast lookup by key */
-
-  unsigned int iMaxKey;               /* Largest key seen since xTruncate() */
+  PgHdr1 *pFree;                      /* List of unused pcache-local pages */
+  void *pBulk;                        /* Bulk memory used by pcache-local */
 };
 
 /*
-** Each cache entry is represented by an instance of the following 
-** structure. A buffer of PgHdr1.pCache->szPage bytes is allocated 
-** directly before this structure in memory (see the PGHDR1_TO_PAGE() 
-** macro below).
-*/
-struct PgHdr1 {
-  unsigned int iKey;             /* Key value (page number) */
-  PgHdr1 *pNext;                 /* Next in hash table chain */
-  PCache1 *pCache;               /* Cache that currently owns this page */
-  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
-  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
-};
-
-/*
-** Free slots in the allocator used to divide up the buffer provided using
-** the SQLITE_CONFIG_PAGECACHE mechanism.
+** Free slots in the allocator used to divide up the global page cache
+** buffer provided using the SQLITE_CONFIG_PAGECACHE mechanism.
 */
 struct PgFreeslot {
   PgFreeslot *pNext;  /* Next free slot */
@@ -35922,14 +44557,16 @@ static SQLITE_WSD struct PCacheGlobal {
   ** The nFreeSlot and pFree values do require mutex protection.
   */
   int isInit;                    /* True if initialized */
+  int separateCache;             /* Use a new PGroup for each PCache */
+  int nInitPage;                 /* Initial bulk allocation size */   
   int szSlot;                    /* Size of each free slot */
   int nSlot;                     /* The number of pcache slots */
   int nReserve;                  /* Try to keep nFreeSlot above this */
-  void *pStart, *pEnd;           /* Bounds of pagecache malloc range */
+  void *pStart, *pEnd;           /* Bounds of global page cache memory */
   /* Above requires no mutex.  Use mutex below for variable that follow. */
   sqlite3_mutex *mutex;          /* Mutex for accessing the following: */
-  int nFreeSlot;                 /* Number of unused pcache slots */
   PgFreeslot *pFree;             /* Free page blocks */
+  int nFreeSlot;                 /* Number of unused pcache slots */
   /* The following value requires a mutex to change.  We skip the mutex on
   ** reading because (1) most platforms read a 32-bit integer atomically and
   ** (2) even if an incorrect value is read, no great harm is done since this
@@ -35945,29 +44582,22 @@ static SQLITE_WSD struct PCacheGlobal {
 #define pcache1 (GLOBAL(struct PCacheGlobal, pcache1_g))
 
 /*
-** When a PgHdr1 structure is allocated, the associated PCache1.szPage
-** bytes of data are located directly before it in memory (i.e. the total
-** size of the allocation is sizeof(PgHdr1)+PCache1.szPage byte). The
-** PGHDR1_TO_PAGE() macro takes a pointer to a PgHdr1 structure as
-** an argument and returns a pointer to the associated block of szPage
-** bytes. The PAGE_TO_PGHDR1() macro does the opposite: its argument is
-** a pointer to a block of szPage bytes of data and the return value is
-** a pointer to the associated PgHdr1 structure.
-**
-**   assert( PGHDR1_TO_PAGE(PAGE_TO_PGHDR1(pCache, X))==X );
-*/
-#define PGHDR1_TO_PAGE(p)    (void*)(((char*)p) - p->pCache->szPage)
-#define PAGE_TO_PGHDR1(c, p) (PgHdr1*)(((char*)p) + c->szPage)
-
-/*
 ** Macros to enter and leave the PCache LRU mutex.
 */
-#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
-#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+#if !defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
+# define pcache1EnterMutex(X)  assert((X)->mutex==0)
+# define pcache1LeaveMutex(X)  assert((X)->mutex==0)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 0
+#else
+# define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
+# define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 1
+#endif
 
 /******************************************************************************/
 /******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/
 
+
 /*
 ** This function is called during initialization if a static buffer is 
 ** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE
@@ -35980,6 +44610,7 @@ static SQLITE_WSD struct PCacheGlobal {
 SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
   if( pcache1.isInit ){
     PgFreeslot *p;
+    if( pBuf==0 ) sz = n = 0;
     sz = ROUNDDOWN8(sz);
     pcache1.szSlot = sz;
     pcache1.nSlot = pcache1.nFreeSlot = n;
@@ -35998,6 +44629,44 @@ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
 }
 
 /*
+** Try to initialize the pCache->pFree and pCache->pBulk fields.  Return
+** true if pCache->pFree ends up containing one or more free pages.
+*/
+static int pcache1InitBulk(PCache1 *pCache){
+  i64 szBulk;
+  char *zBulk;
+  if( pcache1.nInitPage==0 ) return 0;
+  /* Do not bother with a bulk allocation if the cache size very small */
+  if( pCache->nMax<3 ) return 0;
+  sqlite3BeginBenignMalloc();
+  if( pcache1.nInitPage>0 ){
+    szBulk = pCache->szAlloc * (i64)pcache1.nInitPage;
+  }else{
+    szBulk = -1024 * (i64)pcache1.nInitPage;
+  }
+  if( szBulk > pCache->szAlloc*(i64)pCache->nMax ){
+    szBulk = pCache->szAlloc*pCache->nMax;
+  }
+  zBulk = pCache->pBulk = sqlite3Malloc( szBulk );
+  sqlite3EndBenignMalloc();
+  if( zBulk ){
+    int nBulk = sqlite3MallocSize(zBulk)/pCache->szAlloc;
+    int i;
+    for(i=0; i<nBulk; i++){
+      PgHdr1 *pX = (PgHdr1*)&zBulk[pCache->szPage];
+      pX->page.pBuf = zBulk;
+      pX->page.pExtra = &pX[1];
+      pX->isBulkLocal = 1;
+      pX->isAnchor = 0;
+      pX->pNext = pCache->pFree;
+      pCache->pFree = pX;
+      zBulk += pCache->szAlloc;
+    }
+  }
+  return pCache->pFree!=0;
+}
+
+/*
 ** Malloc function used within this file to allocate space from the buffer
 ** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 
 ** such buffer exists or there is no space left in it, this function falls 
@@ -36009,7 +44678,6 @@ SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
 static void *pcache1Alloc(int nByte){
   void *p = 0;
   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
-  sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
   if( nByte<=pcache1.szSlot ){
     sqlite3_mutex_enter(pcache1.mutex);
     p = (PgHdr1 *)pcache1.pFree;
@@ -36018,7 +44686,8 @@ static void *pcache1Alloc(int nByte){
       pcache1.nFreeSlot--;
       pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
       assert( pcache1.nFreeSlot>=0 );
-      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
+      sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
+      sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_USED, 1);
     }
     sqlite3_mutex_leave(pcache1.mutex);
   }
@@ -36027,12 +44696,15 @@ static void *pcache1Alloc(int nByte){
     ** it from sqlite3Malloc instead.
     */
     p = sqlite3Malloc(nByte);
+#ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS
     if( p ){
       int sz = sqlite3MallocSize(p);
       sqlite3_mutex_enter(pcache1.mutex);
-      sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
+      sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);
+      sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);
       sqlite3_mutex_leave(pcache1.mutex);
     }
+#endif
     sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);
   }
   return p;
@@ -36043,10 +44715,10 @@ static void *pcache1Alloc(int nByte){
 */
 static void pcache1Free(void *p){
   if( p==0 ) return;
-  if( p>=pcache1.pStart && p<pcache1.pEnd ){
+  if( SQLITE_WITHIN(p, pcache1.pStart, pcache1.pEnd) ){
     PgFreeslot *pSlot;
     sqlite3_mutex_enter(pcache1.mutex);
-    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
+    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_USED, 1);
     pSlot = (PgFreeslot*)p;
     pSlot->pNext = pcache1.pFree;
     pcache1.pFree = pSlot;
@@ -36055,13 +44727,17 @@ static void pcache1Free(void *p){
     assert( pcache1.nFreeSlot<=pcache1.nSlot );
     sqlite3_mutex_leave(pcache1.mutex);
   }else{
-    int iSize;
     assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
     sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
-    iSize = sqlite3MallocSize(p);
-    sqlite3_mutex_enter(pcache1.mutex);
-    sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -iSize);
-    sqlite3_mutex_leave(pcache1.mutex);
+#ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS
+    {
+      int nFreed = 0;
+      nFreed = sqlite3MallocSize(p);
+      sqlite3_mutex_enter(pcache1.mutex);
+      sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);
+      sqlite3_mutex_leave(pcache1.mutex);
+    }
+#endif
     sqlite3_free(p);
   }
 }
@@ -36087,43 +44763,72 @@ static int pcache1MemSize(void *p){
 /*
 ** Allocate a new page object initially associated with cache pCache.
 */
-static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
-  int nByte = sizeof(PgHdr1) + pCache->szPage;
+static PgHdr1 *pcache1AllocPage(PCache1 *pCache, int benignMalloc){
   PgHdr1 *p = 0;
   void *pPg;
 
-  /* The group mutex must be released before pcache1Alloc() is called. This
-  ** is because it may call sqlite3_release_memory(), which assumes that 
-  ** this mutex is not held. */
   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
-  pcache1LeaveMutex(pCache->pGroup);
-  pPg = pcache1Alloc(nByte);
-  pcache1EnterMutex(pCache->pGroup);
-
-  if( pPg ){
-    p = PAGE_TO_PGHDR1(pCache, pPg);
-    if( pCache->bPurgeable ){
-      pCache->pGroup->nCurrentPage++;
+  if( pCache->pFree || (pCache->nPage==0 && pcache1InitBulk(pCache)) ){
+    p = pCache->pFree;
+    pCache->pFree = p->pNext;
+    p->pNext = 0;
+  }else{
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+    /* The group mutex must be released before pcache1Alloc() is called. This
+    ** is because it might call sqlite3_release_memory(), which assumes that 
+    ** this mutex is not held. */
+    assert( pcache1.separateCache==0 );
+    assert( pCache->pGroup==&pcache1.grp );
+    pcache1LeaveMutex(pCache->pGroup);
+#endif
+    if( benignMalloc ){ sqlite3BeginBenignMalloc(); }
+#ifdef SQLITE_PCACHE_SEPARATE_HEADER
+    pPg = pcache1Alloc(pCache->szPage);
+    p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);
+    if( !pPg || !p ){
+      pcache1Free(pPg);
+      sqlite3_free(p);
+      pPg = 0;
     }
+#else
+    pPg = pcache1Alloc(pCache->szAlloc);
+    p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];
+#endif
+    if( benignMalloc ){ sqlite3EndBenignMalloc(); }
+#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+    pcache1EnterMutex(pCache->pGroup);
+#endif
+    if( pPg==0 ) return 0;
+    p->page.pBuf = pPg;
+    p->page.pExtra = &p[1];
+    p->isBulkLocal = 0;
+    p->isAnchor = 0;
+  }
+  if( pCache->bPurgeable ){
+    pCache->pGroup->nCurrentPage++;
   }
   return p;
 }
 
 /*
 ** Free a page object allocated by pcache1AllocPage().
-**
-** The pointer is allowed to be NULL, which is prudent.  But it turns out
-** that the current implementation happens to never call this routine
-** with a NULL pointer, so we mark the NULL test with ALWAYS().
 */
 static void pcache1FreePage(PgHdr1 *p){
-  if( ALWAYS(p) ){
-    PCache1 *pCache = p->pCache;
-    assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
-    pcache1Free(PGHDR1_TO_PAGE(p));
-    if( pCache->bPurgeable ){
-      pCache->pGroup->nCurrentPage--;
-    }
+  PCache1 *pCache;
+  assert( p!=0 );
+  pCache = p->pCache;
+  assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
+  if( p->isBulkLocal ){
+    p->pNext = pCache->pFree;
+    pCache->pFree = p;
+  }else{
+    pcache1Free(p->page.pBuf);
+#ifdef SQLITE_PCACHE_SEPARATE_HEADER
+    sqlite3_free(p);
+#endif
+  }
+  if( pCache->bPurgeable ){
+    pCache->pGroup->nCurrentPage--;
   }
 }
 
@@ -36155,13 +44860,13 @@ SQLITE_PRIVATE void sqlite3PageFree(void *p){
 ** for all page cache needs and we should not need to spill the
 ** allocation onto the heap.
 **
-** Or, the heap is used for all page cache memory put the heap is
+** Or, the heap is used for all page cache memory but the heap is
 ** under memory pressure, then again it is desirable to avoid
 ** allocating a new page cache entry in order to avoid stressing
 ** the heap even further.
 */
 static int pcache1UnderMemoryPressure(PCache1 *pCache){
-  if( pcache1.nSlot && pCache->szPage<=pcache1.szSlot ){
+  if( pcache1.nSlot && (pCache->szPage+pCache->szExtra)<=pcache1.szSlot ){
     return pcache1.bUnderPressure;
   }else{
     return sqlite3HeapNearlyFull();
@@ -36177,7 +44882,7 @@ static int pcache1UnderMemoryPressure(PCache1 *pCache){
 **
 ** The PCache mutex must be held when this function is called.
 */
-static int pcache1ResizeHash(PCache1 *p){
+static void pcache1ResizeHash(PCache1 *p){
   PgHdr1 **apNew;
   unsigned int nNew;
   unsigned int i;
@@ -36191,11 +44896,10 @@ static int pcache1ResizeHash(PCache1 *p){
 
   pcache1LeaveMutex(p->pGroup);
   if( p->nHash ){ sqlite3BeginBenignMalloc(); }
-  apNew = (PgHdr1 **)sqlite3_malloc(sizeof(PgHdr1 *)*nNew);
+  apNew = (PgHdr1 **)sqlite3MallocZero(sizeof(PgHdr1 *)*nNew);
   if( p->nHash ){ sqlite3EndBenignMalloc(); }
   pcache1EnterMutex(p->pGroup);
   if( apNew ){
-    memset(apNew, 0, sizeof(PgHdr1 *)*nNew);
     for(i=0; i<p->nHash; i++){
       PgHdr1 *pPage;
       PgHdr1 *pNext = p->apHash[i];
@@ -36210,8 +44914,6 @@ static int pcache1ResizeHash(PCache1 *p){
     p->apHash = apNew;
     p->nHash = nNew;
   }
-
-  return (p->apHash ? SQLITE_OK : SQLITE_NOMEM);
 }
 
 /*
@@ -36220,44 +44922,36 @@ static int pcache1ResizeHash(PCache1 *p){
 ** LRU list, then this function is a no-op.
 **
 ** The PGroup mutex must be held when this function is called.
-**
-** If pPage is NULL then this routine is a no-op.
 */
-static void pcache1PinPage(PgHdr1 *pPage){
+static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){
   PCache1 *pCache;
-  PGroup *pGroup;
 
-  if( pPage==0 ) return;
+  assert( pPage!=0 );
+  assert( pPage->isPinned==0 );
   pCache = pPage->pCache;
-  pGroup = pCache->pGroup;
-  assert( sqlite3_mutex_held(pGroup->mutex) );
-  if( pPage->pLruNext || pPage==pGroup->pLruTail ){
-    if( pPage->pLruPrev ){
-      pPage->pLruPrev->pLruNext = pPage->pLruNext;
-    }
-    if( pPage->pLruNext ){
-      pPage->pLruNext->pLruPrev = pPage->pLruPrev;
-    }
-    if( pGroup->pLruHead==pPage ){
-      pGroup->pLruHead = pPage->pLruNext;
-    }
-    if( pGroup->pLruTail==pPage ){
-      pGroup->pLruTail = pPage->pLruPrev;
-    }
-    pPage->pLruNext = 0;
-    pPage->pLruPrev = 0;
-    pPage->pCache->nRecyclable--;
-  }
+  assert( pPage->pLruNext );
+  assert( pPage->pLruPrev );
+  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
+  pPage->pLruPrev->pLruNext = pPage->pLruNext;
+  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
+  pPage->pLruNext = 0;
+  pPage->pLruPrev = 0;
+  pPage->isPinned = 1;
+  assert( pPage->isAnchor==0 );
+  assert( pCache->pGroup->lru.isAnchor==1 );
+  pCache->nRecyclable--;
+  return pPage;
 }
 
 
 /*
 ** Remove the page supplied as an argument from the hash table 
 ** (PCache1.apHash structure) that it is currently stored in.
+** Also free the page if freePage is true.
 **
 ** The PGroup mutex must be held when this function is called.
 */
-static void pcache1RemoveFromHash(PgHdr1 *pPage){
+static void pcache1RemoveFromHash(PgHdr1 *pPage, int freeFlag){
   unsigned int h;
   PCache1 *pCache = pPage->pCache;
   PgHdr1 **pp;
@@ -36268,20 +44962,28 @@ static void pcache1RemoveFromHash(PgHdr1 *pPage){
   *pp = (*pp)->pNext;
 
   pCache->nPage--;
+  if( freeFlag ) pcache1FreePage(pPage);
 }
 
 /*
 ** If there are currently more than nMaxPage pages allocated, try
 ** to recycle pages to reduce the number allocated to nMaxPage.
 */
-static void pcache1EnforceMaxPage(PGroup *pGroup){
+static void pcache1EnforceMaxPage(PCache1 *pCache){
+  PGroup *pGroup = pCache->pGroup;
+  PgHdr1 *p;
   assert( sqlite3_mutex_held(pGroup->mutex) );
-  while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){
-    PgHdr1 *p = pGroup->pLruTail;
+  while( pGroup->nCurrentPage>pGroup->nMaxPage
+      && (p=pGroup->lru.pLruPrev)->isAnchor==0
+  ){
     assert( p->pCache->pGroup==pGroup );
+    assert( p->isPinned==0 );
     pcache1PinPage(p);
-    pcache1RemoveFromHash(p);
-    pcache1FreePage(p);
+    pcache1RemoveFromHash(p, 1);
+  }
+  if( pCache->nPage==0 && pCache->pBulk ){
+    sqlite3_free(pCache->pBulk);
+    pCache->pBulk = pCache->pFree = 0;
   }
 }
 
@@ -36296,25 +44998,45 @@ static void pcache1TruncateUnsafe(
   PCache1 *pCache,             /* The cache to truncate */
   unsigned int iLimit          /* Drop pages with this pgno or larger */
 ){
-  TESTONLY( unsigned int nPage = 0; )  /* To assert pCache->nPage is correct */
-  unsigned int h;
+  TESTONLY( int nPage = 0; )  /* To assert pCache->nPage is correct */
+  unsigned int h, iStop;
   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
-  for(h=0; h<pCache->nHash; h++){
-    PgHdr1 **pp = &pCache->apHash[h]; 
+  assert( pCache->iMaxKey >= iLimit );
+  assert( pCache->nHash > 0 );
+  if( pCache->iMaxKey - iLimit < pCache->nHash ){
+    /* If we are just shaving the last few pages off the end of the
+    ** cache, then there is no point in scanning the entire hash table.
+    ** Only scan those hash slots that might contain pages that need to
+    ** be removed. */
+    h = iLimit % pCache->nHash;
+    iStop = pCache->iMaxKey % pCache->nHash;
+    TESTONLY( nPage = -10; )  /* Disable the pCache->nPage validity check */
+  }else{
+    /* This is the general case where many pages are being removed.
+    ** It is necessary to scan the entire hash table */
+    h = pCache->nHash/2;
+    iStop = h - 1;
+  }
+  for(;;){
+    PgHdr1 **pp;
     PgHdr1 *pPage;
+    assert( h<pCache->nHash );
+    pp = &pCache->apHash[h]; 
     while( (pPage = *pp)!=0 ){
       if( pPage->iKey>=iLimit ){
         pCache->nPage--;
         *pp = pPage->pNext;
-        pcache1PinPage(pPage);
+        if( !pPage->isPinned ) pcache1PinPage(pPage);
         pcache1FreePage(pPage);
       }else{
         pp = &pPage->pNext;
-        TESTONLY( nPage++; )
+        TESTONLY( if( nPage>=0 ) nPage++; )
       }
     }
+    if( h==iStop ) break;
+    h = (h+1) % pCache->nHash;
   }
-  assert( pCache->nPage==nPage );
+  assert( nPage<0 || pCache->nPage==(unsigned)nPage );
 }
 
 /******************************************************************************/
@@ -36327,9 +45049,44 @@ static int pcache1Init(void *NotUsed){
   UNUSED_PARAMETER(NotUsed);
   assert( pcache1.isInit==0 );
   memset(&pcache1, 0, sizeof(pcache1));
+
+
+  /*
+  ** The pcache1.separateCache variable is true if each PCache has its own
+  ** private PGroup (mode-1).  pcache1.separateCache is false if the single
+  ** PGroup in pcache1.grp is used for all page caches (mode-2).
+  **
+  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
+  **
+  **   *  Use a unified cache in single-threaded applications that have
+  **      configured a start-time buffer for use as page-cache memory using
+  **      sqlite3_config(SQLITE_CONFIG_PAGECACHE, pBuf, sz, N) with non-NULL 
+  **      pBuf argument.
+  **
+  **   *  Otherwise use separate caches (mode-1)
+  */
+#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
+  pcache1.separateCache = 0;
+#elif SQLITE_THREADSAFE
+  pcache1.separateCache = sqlite3GlobalConfig.pPage==0
+                          || sqlite3GlobalConfig.bCoreMutex>0;
+#else
+  pcache1.separateCache = sqlite3GlobalConfig.pPage==0;
+#endif
+
+#if SQLITE_THREADSAFE
   if( sqlite3GlobalConfig.bCoreMutex ){
-    pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
-    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM);
+    pcache1.grp.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU);
+    pcache1.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PMEM);
+  }
+#endif
+  if( pcache1.separateCache
+   && sqlite3GlobalConfig.nPage!=0
+   && sqlite3GlobalConfig.pPage==0
+  ){
+    pcache1.nInitPage = sqlite3GlobalConfig.nPage;
+  }else{
+    pcache1.nInitPage = 0;
   }
   pcache1.grp.mxPinned = 10;
   pcache1.isInit = 1;
@@ -36347,53 +45104,51 @@ static void pcache1Shutdown(void *NotUsed){
   memset(&pcache1, 0, sizeof(pcache1));
 }
 
+/* forward declaration */
+static void pcache1Destroy(sqlite3_pcache *p);
+
 /*
 ** Implementation of the sqlite3_pcache.xCreate method.
 **
 ** Allocate a new cache.
 */
-static sqlite3_pcache *pcache1Create(int szPage, int bPurgeable){
+static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
   PCache1 *pCache;      /* The newly created page cache */
   PGroup *pGroup;       /* The group the new page cache will belong to */
   int sz;               /* Bytes of memory required to allocate the new cache */
 
-  /*
-  ** The seperateCache variable is true if each PCache has its own private
-  ** PGroup.  In other words, separateCache is true for mode (1) where no
-  ** mutexing is required.
-  **
-  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
-  **
-  **   *  Always use a unified cache in single-threaded applications
-  **
-  **   *  Otherwise (if multi-threaded and ENABLE_MEMORY_MANAGEMENT is off)
-  **      use separate caches (mode-1)
-  */
-#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
-  const int separateCache = 0;
-#else
-  int separateCache = sqlite3GlobalConfig.bCoreMutex>0;
-#endif
+  assert( (szPage & (szPage-1))==0 && szPage>=512 && szPage<=65536 );
+  assert( szExtra < 300 );
 
-  sz = sizeof(PCache1) + sizeof(PGroup)*separateCache;
-  pCache = (PCache1 *)sqlite3_malloc(sz);
+  sz = sizeof(PCache1) + sizeof(PGroup)*pcache1.separateCache;
+  pCache = (PCache1 *)sqlite3MallocZero(sz);
   if( pCache ){
-    memset(pCache, 0, sz);
-    if( separateCache ){
+    if( pcache1.separateCache ){
       pGroup = (PGroup*)&pCache[1];
       pGroup->mxPinned = 10;
     }else{
       pGroup = &pcache1.grp;
     }
+    if( pGroup->lru.isAnchor==0 ){
+      pGroup->lru.isAnchor = 1;
+      pGroup->lru.pLruPrev = pGroup->lru.pLruNext = &pGroup->lru;
+    }
     pCache->pGroup = pGroup;
     pCache->szPage = szPage;
+    pCache->szExtra = szExtra;
+    pCache->szAlloc = szPage + szExtra + ROUND8(sizeof(PgHdr1));
     pCache->bPurgeable = (bPurgeable ? 1 : 0);
+    pcache1EnterMutex(pGroup);
+    pcache1ResizeHash(pCache);
     if( bPurgeable ){
       pCache->nMin = 10;
-      pcache1EnterMutex(pGroup);
       pGroup->nMinPage += pCache->nMin;
       pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
-      pcache1LeaveMutex(pGroup);
+    }
+    pcache1LeaveMutex(pGroup);
+    if( pCache->nHash==0 ){
+      pcache1Destroy((sqlite3_pcache*)pCache);
+      pCache = 0;
     }
   }
   return (sqlite3_pcache *)pCache;
@@ -36413,7 +45168,26 @@ static void pcache1Cachesize(sqlite3_pcache *p, int nMax){
     pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
     pCache->nMax = nMax;
     pCache->n90pct = pCache->nMax*9/10;
-    pcache1EnforceMaxPage(pGroup);
+    pcache1EnforceMaxPage(pCache);
+    pcache1LeaveMutex(pGroup);
+  }
+}
+
+/*
+** Implementation of the sqlite3_pcache.xShrink method. 
+**
+** Free up as much memory as possible.
+*/
+static void pcache1Shrink(sqlite3_pcache *p){
+  PCache1 *pCache = (PCache1*)p;
+  if( pCache->bPurgeable ){
+    PGroup *pGroup = pCache->pGroup;
+    int savedMaxPage;
+    pcache1EnterMutex(pGroup);
+    savedMaxPage = pGroup->nMaxPage;
+    pGroup->nMaxPage = 0;
+    pcache1EnforceMaxPage(pCache);
+    pGroup->nMaxPage = savedMaxPage;
     pcache1LeaveMutex(pGroup);
   }
 }
@@ -36430,6 +45204,84 @@ static int pcache1Pagecount(sqlite3_pcache *p){
   return n;
 }
 
+
+/*
+** Implement steps 3, 4, and 5 of the pcache1Fetch() algorithm described
+** in the header of the pcache1Fetch() procedure.
+**
+** This steps are broken out into a separate procedure because they are
+** usually not needed, and by avoiding the stack initialization required
+** for these steps, the main pcache1Fetch() procedure can run faster.
+*/
+static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
+  PCache1 *pCache, 
+  unsigned int iKey, 
+  int createFlag
+){
+  unsigned int nPinned;
+  PGroup *pGroup = pCache->pGroup;
+  PgHdr1 *pPage = 0;
+
+  /* Step 3: Abort if createFlag is 1 but the cache is nearly full */
+  assert( pCache->nPage >= pCache->nRecyclable );
+  nPinned = pCache->nPage - pCache->nRecyclable;
+  assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage );
+  assert( pCache->n90pct == pCache->nMax*9/10 );
+  if( createFlag==1 && (
+        nPinned>=pGroup->mxPinned
+     || nPinned>=pCache->n90pct
+     || (pcache1UnderMemoryPressure(pCache) && pCache->nRecyclable<nPinned)
+  )){
+    return 0;
+  }
+
+  if( pCache->nPage>=pCache->nHash ) pcache1ResizeHash(pCache);
+  assert( pCache->nHash>0 && pCache->apHash );
+
+  /* Step 4. Try to recycle a page. */
+  if( pCache->bPurgeable
+   && !pGroup->lru.pLruPrev->isAnchor
+   && ((pCache->nPage+1>=pCache->nMax) || pcache1UnderMemoryPressure(pCache))
+  ){
+    PCache1 *pOther;
+    pPage = pGroup->lru.pLruPrev;
+    assert( pPage->isPinned==0 );
+    pcache1RemoveFromHash(pPage, 0);
+    pcache1PinPage(pPage);
+    pOther = pPage->pCache;
+    if( pOther->szAlloc != pCache->szAlloc ){
+      pcache1FreePage(pPage);
+      pPage = 0;
+    }else{
+      pGroup->nCurrentPage -= (pOther->bPurgeable - pCache->bPurgeable);
+    }
+  }
+
+  /* Step 5. If a usable page buffer has still not been found, 
+  ** attempt to allocate a new one. 
+  */
+  if( !pPage ){
+    pPage = pcache1AllocPage(pCache, createFlag==1);
+  }
+
+  if( pPage ){
+    unsigned int h = iKey % pCache->nHash;
+    pCache->nPage++;
+    pPage->iKey = iKey;
+    pPage->pNext = pCache->apHash[h];
+    pPage->pCache = pCache;
+    pPage->pLruPrev = 0;
+    pPage->pLruNext = 0;
+    pPage->isPinned = 1;
+    *(void **)pPage->page.pExtra = 0;
+    pCache->apHash[h] = pPage;
+    if( iKey>pCache->iMaxKey ){
+      pCache->iMaxKey = iKey;
+    }
+  }
+  return pPage;
+}
+
 /*
 ** Implementation of the sqlite3_pcache.xFetch method. 
 **
@@ -36443,7 +45295,7 @@ static int pcache1Pagecount(sqlite3_pcache *p){
 ** For a non-purgeable cache (a cache used as the storage for an in-memory
 ** database) there is really no difference between createFlag 1 and 2.  So
 ** the calling function (pcache.c) will never have a createFlag of 1 on
-** a non-purgable cache.
+** a non-purgeable cache.
 **
 ** There are three different approaches to obtaining space for a page,
 ** depending on the value of parameter createFlag (which may be 0, 1 or 2).
@@ -36483,106 +45335,80 @@ static int pcache1Pagecount(sqlite3_pcache *p){
 **      proceed to step 5. 
 **
 **   5. Otherwise, allocate and return a new page buffer.
+**
+** There are two versions of this routine.  pcache1FetchWithMutex() is
+** the general case.  pcache1FetchNoMutex() is a faster implementation for
+** the common case where pGroup->mutex is NULL.  The pcache1Fetch() wrapper
+** invokes the appropriate routine.
 */
-static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){
-  int nPinned;
+static PgHdr1 *pcache1FetchNoMutex(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
   PCache1 *pCache = (PCache1 *)p;
-  PGroup *pGroup;
   PgHdr1 *pPage = 0;
 
-  assert( pCache->bPurgeable || createFlag!=1 );
-  assert( pCache->bPurgeable || pCache->nMin==0 );
-  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
-  assert( pCache->nMin==0 || pCache->bPurgeable );
-  pcache1EnterMutex(pGroup = pCache->pGroup);
-
   /* Step 1: Search the hash table for an existing entry. */
-  if( pCache->nHash>0 ){
-    unsigned int h = iKey % pCache->nHash;
-    for(pPage=pCache->apHash[h]; pPage&&pPage->iKey!=iKey; pPage=pPage->pNext);
-  }
+  pPage = pCache->apHash[iKey % pCache->nHash];
+  while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; }
 
-  /* Step 2: Abort if no existing page is found and createFlag is 0 */
-  if( pPage || createFlag==0 ){
-    pcache1PinPage(pPage);
-    goto fetch_out;
-  }
-
-  /* The pGroup local variable will normally be initialized by the
-  ** pcache1EnterMutex() macro above.  But if SQLITE_MUTEX_OMIT is defined,
-  ** then pcache1EnterMutex() is a no-op, so we have to initialize the
-  ** local variable here.  Delaying the initialization of pGroup is an
-  ** optimization:  The common case is to exit the module before reaching
-  ** this point.
-  */
-#ifdef SQLITE_MUTEX_OMIT
-  pGroup = pCache->pGroup;
-#endif
-
-
-  /* Step 3: Abort if createFlag is 1 but the cache is nearly full */
-  nPinned = pCache->nPage - pCache->nRecyclable;
-  assert( nPinned>=0 );
-  assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage );
-  assert( pCache->n90pct == pCache->nMax*9/10 );
-  if( createFlag==1 && (
-        nPinned>=pGroup->mxPinned
-     || nPinned>=(int)pCache->n90pct
-     || pcache1UnderMemoryPressure(pCache)
-  )){
-    goto fetch_out;
-  }
-
-  if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){
-    goto fetch_out;
-  }
-
-  /* Step 4. Try to recycle a page. */
-  if( pCache->bPurgeable && pGroup->pLruTail && (
-         (pCache->nPage+1>=pCache->nMax)
-      || pGroup->nCurrentPage>=pGroup->nMaxPage
-      || pcache1UnderMemoryPressure(pCache)
-  )){
-    PCache1 *pOtherCache;
-    pPage = pGroup->pLruTail;
-    pcache1RemoveFromHash(pPage);
-    pcache1PinPage(pPage);
-    if( (pOtherCache = pPage->pCache)->szPage!=pCache->szPage ){
-      pcache1FreePage(pPage);
-      pPage = 0;
+  /* Step 2: If the page was found in the hash table, then return it.
+  ** If the page was not in the hash table and createFlag is 0, abort.
+  ** Otherwise (page not in hash and createFlag!=0) continue with
+  ** subsequent steps to try to create the page. */
+  if( pPage ){
+    if( !pPage->isPinned ){
+      return pcache1PinPage(pPage);
     }else{
-      pGroup->nCurrentPage -= 
-               (pOtherCache->bPurgeable - pCache->bPurgeable);
+      return pPage;
     }
+  }else if( createFlag ){
+    /* Steps 3, 4, and 5 implemented by this subroutine */
+    return pcache1FetchStage2(pCache, iKey, createFlag);
+  }else{
+    return 0;
   }
+}
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+static PgHdr1 *pcache1FetchWithMutex(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+  PCache1 *pCache = (PCache1 *)p;
+  PgHdr1 *pPage;
 
-  /* Step 5. If a usable page buffer has still not been found, 
-  ** attempt to allocate a new one. 
-  */
-  if( !pPage ){
-    if( createFlag==1 ) sqlite3BeginBenignMalloc();
-    pPage = pcache1AllocPage(pCache);
-    if( createFlag==1 ) sqlite3EndBenignMalloc();
-  }
-
-  if( pPage ){
-    unsigned int h = iKey % pCache->nHash;
-    pCache->nPage++;
-    pPage->iKey = iKey;
-    pPage->pNext = pCache->apHash[h];
-    pPage->pCache = pCache;
-    pPage->pLruPrev = 0;
-    pPage->pLruNext = 0;
-    *(void **)(PGHDR1_TO_PAGE(pPage)) = 0;
-    pCache->apHash[h] = pPage;
-  }
+  pcache1EnterMutex(pCache->pGroup);
+  pPage = pcache1FetchNoMutex(p, iKey, createFlag);
+  assert( pPage==0 || pCache->iMaxKey>=iKey );
+  pcache1LeaveMutex(pCache->pGroup);
+  return pPage;
+}
+#endif
+static sqlite3_pcache_page *pcache1Fetch(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX || defined(SQLITE_DEBUG)
+  PCache1 *pCache = (PCache1 *)p;
+#endif
 
-fetch_out:
-  if( pPage && iKey>pCache->iMaxKey ){
-    pCache->iMaxKey = iKey;
+  assert( offsetof(PgHdr1,page)==0 );
+  assert( pCache->bPurgeable || createFlag!=1 );
+  assert( pCache->bPurgeable || pCache->nMin==0 );
+  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
+  assert( pCache->nMin==0 || pCache->bPurgeable );
+  assert( pCache->nHash>0 );
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+  if( pCache->pGroup->mutex ){
+    return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag);
+  }else
+#endif
+  {
+    return (sqlite3_pcache_page*)pcache1FetchNoMutex(p, iKey, createFlag);
   }
-  pcache1LeaveMutex(pGroup);
-  return (pPage ? PGHDR1_TO_PAGE(pPage) : 0);
 }
 
 
@@ -36591,9 +45417,13 @@ fetch_out:
 **
 ** Mark a page as unpinned (eligible for asynchronous recycling).
 */
-static void pcache1Unpin(sqlite3_pcache *p, void *pPg, int reuseUnlikely){
+static void pcache1Unpin(
+  sqlite3_pcache *p, 
+  sqlite3_pcache_page *pPg, 
+  int reuseUnlikely
+){
   PCache1 *pCache = (PCache1 *)p;
-  PgHdr1 *pPage = PAGE_TO_PGHDR1(pCache, pPg);
+  PgHdr1 *pPage = (PgHdr1 *)pPg;
   PGroup *pGroup = pCache->pGroup;
  
   assert( pPage->pCache==pCache );
@@ -36603,22 +45433,18 @@ static void pcache1Unpin(sqlite3_pcache *p, void *pPg, int reuseUnlikely){
   ** part of the PGroup LRU list.
   */
   assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
-  assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage );
+  assert( pPage->isPinned==1 );
 
   if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
-    pcache1RemoveFromHash(pPage);
-    pcache1FreePage(pPage);
+    pcache1RemoveFromHash(pPage, 1);
   }else{
     /* Add the page to the PGroup LRU list. */
-    if( pGroup->pLruHead ){
-      pGroup->pLruHead->pLruPrev = pPage;
-      pPage->pLruNext = pGroup->pLruHead;
-      pGroup->pLruHead = pPage;
-    }else{
-      pGroup->pLruTail = pPage;
-      pGroup->pLruHead = pPage;
-    }
+    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;
+    pPage->pLruPrev = &pGroup->lru;
+    (pPage->pLruNext = *ppFirst)->pLruPrev = pPage;
+    *ppFirst = pPage;
     pCache->nRecyclable++;
+    pPage->isPinned = 0;
   }
 
   pcache1LeaveMutex(pCache->pGroup);
@@ -36629,12 +45455,12 @@ static void pcache1Unpin(sqlite3_pcache *p, void *pPg, int reuseUnlikely){
 */
 static void pcache1Rekey(
   sqlite3_pcache *p,
-  void *pPg,
+  sqlite3_pcache_page *pPg,
   unsigned int iOld,
   unsigned int iNew
 ){
   PCache1 *pCache = (PCache1 *)p;
-  PgHdr1 *pPage = PAGE_TO_PGHDR1(pCache, pPg);
+  PgHdr1 *pPage = (PgHdr1 *)pPg;
   PgHdr1 **pp;
   unsigned int h; 
   assert( pPage->iKey==iOld );
@@ -36687,12 +45513,15 @@ static void pcache1Destroy(sqlite3_pcache *p){
   PGroup *pGroup = pCache->pGroup;
   assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) );
   pcache1EnterMutex(pGroup);
-  pcache1TruncateUnsafe(pCache, 0);
+  if( pCache->nPage ) pcache1TruncateUnsafe(pCache, 0);
+  assert( pGroup->nMaxPage >= pCache->nMax );
   pGroup->nMaxPage -= pCache->nMax;
+  assert( pGroup->nMinPage >= pCache->nMin );
   pGroup->nMinPage -= pCache->nMin;
   pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
-  pcache1EnforceMaxPage(pGroup);
+  pcache1EnforceMaxPage(pCache);
   pcache1LeaveMutex(pGroup);
+  sqlite3_free(pCache->pBulk);
   sqlite3_free(pCache->apHash);
   sqlite3_free(pCache);
 }
@@ -36703,7 +45532,8 @@ static void pcache1Destroy(sqlite3_pcache *p){
 ** already provided an alternative.
 */
 SQLITE_PRIVATE void sqlite3PCacheSetDefault(void){
-  static const sqlite3_pcache_methods defaultMethods = {
+  static const sqlite3_pcache_methods2 defaultMethods = {
+    1,                       /* iVersion */
     0,                       /* pArg */
     pcache1Init,             /* xInit */
     pcache1Shutdown,         /* xShutdown */
@@ -36714,9 +45544,23 @@ SQLITE_PRIVATE void sqlite3PCacheSetDefault(void){
     pcache1Unpin,            /* xUnpin */
     pcache1Rekey,            /* xRekey */
     pcache1Truncate,         /* xTruncate */
-    pcache1Destroy           /* xDestroy */
+    pcache1Destroy,          /* xDestroy */
+    pcache1Shrink            /* xShrink */
   };
-  sqlite3_config(SQLITE_CONFIG_PCACHE, &defaultMethods);
+  sqlite3_config(SQLITE_CONFIG_PCACHE2, &defaultMethods);
+}
+
+/*
+** Return the size of the header on each page of this PCACHE implementation.
+*/
+SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void){ return ROUND8(sizeof(PgHdr1)); }
+
+/*
+** Return the global mutex used by this PCACHE implementation.  The
+** sqlite3_status() routine needs access to this mutex.
+*/
+SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void){
+  return pcache1.mutex;
 }
 
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
@@ -36733,14 +45577,20 @@ SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int nReq){
   int nFree = 0;
   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
   assert( sqlite3_mutex_notheld(pcache1.mutex) );
-  if( pcache1.pStart==0 ){
+  if( sqlite3GlobalConfig.nPage==0 ){
     PgHdr1 *p;
     pcache1EnterMutex(&pcache1.grp);
-    while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
-      nFree += pcache1MemSize(PGHDR1_TO_PAGE(p));
+    while( (nReq<0 || nFree<nReq)
+       &&  (p=pcache1.grp.lru.pLruPrev)!=0
+       &&  p->isAnchor==0
+    ){
+      nFree += pcache1MemSize(p->page.pBuf);
+#ifdef SQLITE_PCACHE_SEPARATE_HEADER
+      nFree += sqlite3MemSize(p);
+#endif
+      assert( p->isPinned==0 );
       pcache1PinPage(p);
-      pcache1RemoveFromHash(p);
-      pcache1FreePage(p);
+      pcache1RemoveFromHash(p, 1);
     }
     pcache1LeaveMutex(&pcache1.grp);
   }
@@ -36761,12 +45611,13 @@ SQLITE_PRIVATE void sqlite3PcacheStats(
 ){
   PgHdr1 *p;
   int nRecyclable = 0;
-  for(p=pcache1.grp.pLruHead; p; p=p->pLruNext){
+  for(p=pcache1.grp.lru.pLruNext; p && !p->isAnchor; p=p->pLruNext){
+    assert( p->isPinned==0 );
     nRecyclable++;
   }
   *pnCurrent = pcache1.grp.nCurrentPage;
-  *pnMax = pcache1.grp.nMaxPage;
-  *pnMin = pcache1.grp.nMinPage;
+  *pnMax = (int)pcache1.grp.nMaxPage;
+  *pnMin = (int)pcache1.grp.nMinPage;
   *pnRecyclable = nRecyclable;
 }
 #endif
@@ -36825,16 +45676,18 @@ SQLITE_PRIVATE void sqlite3PcacheStats(
 ** No INSERTs may occurs after a SMALLEST.  An assertion will fail if
 ** that is attempted.
 **
-** The cost of an INSERT is roughly constant.  (Sometime new memory
+** The cost of an INSERT is roughly constant.  (Sometimes new memory
 ** has to be allocated on an INSERT.)  The cost of a TEST with a new
 ** batch number is O(NlogN) where N is the number of elements in the RowSet.
 ** The cost of a TEST using the same batch number is O(logN).  The cost
 ** of the first SMALLEST is O(NlogN).  Second and subsequent SMALLEST
 ** primitives are constant time.  The cost of DESTROY is O(N).
 **
-** There is an added cost of O(N) when switching between TEST and
-** SMALLEST primitives.
+** TEST and SMALLEST may not be used by the same RowSet.  This used to
+** be possible, but the feature was not used, so it was removed in order
+** to simplify the code.
 */
+/* #include "sqliteInt.h" */
 
 
 /*
@@ -36850,6 +45703,11 @@ SQLITE_PRIVATE void sqlite3PcacheStats(
 
 /*
 ** Each entry in a RowSet is an instance of the following object.
+**
+** This same object is reused to store a linked list of trees of RowSetEntry
+** objects.  In that alternative use, pRight points to the next entry
+** in the list, pLeft points to the tree, and v is unused.  The
+** RowSet.pForest value points to the head of this forest list.
 */
 struct RowSetEntry {            
   i64 v;                        /* ROWID value for this entry */
@@ -36879,13 +45737,19 @@ struct RowSet {
   struct RowSetEntry *pEntry;    /* List of entries using pRight */
   struct RowSetEntry *pLast;     /* Last entry on the pEntry list */
   struct RowSetEntry *pFresh;    /* Source of new entry objects */
-  struct RowSetEntry *pTree;     /* Binary tree of entries */
+  struct RowSetEntry *pForest;   /* List of binary trees of entries */
   u16 nFresh;                    /* Number of objects on pFresh */
-  u8 isSorted;                   /* True if pEntry is sorted */
-  u8 iBatch;                     /* Current insert batch */
+  u16 rsFlags;                   /* Various flags */
+  int iBatch;                    /* Current insert batch */
 };
 
 /*
+** Allowed values for RowSet.rsFlags
+*/
+#define ROWSET_SORTED  0x01   /* True if RowSet.pEntry is sorted */
+#define ROWSET_NEXT    0x02   /* True if sqlite3RowSetNext() has been called */
+
+/*
 ** Turn bulk memory into a RowSet object.  N bytes of memory
 ** are available at pSpace.  The db pointer is used as a memory context
 ** for any subsequent allocations that need to occur.
@@ -36905,10 +45769,10 @@ SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3 *db, void *pSpace, unsigned int
   p->db = db;
   p->pEntry = 0;
   p->pLast = 0;
-  p->pTree = 0;
+  p->pForest = 0;
   p->pFresh = (struct RowSetEntry*)(ROUND8(sizeof(*p)) + (char*)p);
   p->nFresh = (u16)((N - ROUND8(sizeof(*p)))/sizeof(struct RowSetEntry));
-  p->isSorted = 1;
+  p->rsFlags = ROWSET_SORTED;
   p->iBatch = 0;
   return p;
 }
@@ -36928,43 +45792,63 @@ SQLITE_PRIVATE void sqlite3RowSetClear(RowSet *p){
   p->nFresh = 0;
   p->pEntry = 0;
   p->pLast = 0;
-  p->pTree = 0;
-  p->isSorted = 1;
+  p->pForest = 0;
+  p->rsFlags = ROWSET_SORTED;
 }
 
 /*
-** Insert a new value into a RowSet.
+** Allocate a new RowSetEntry object that is associated with the
+** given RowSet.  Return a pointer to the new and completely uninitialized
+** objected.
 **
-** The mallocFailed flag of the database connection is set if a
-** memory allocation fails.
+** In an OOM situation, the RowSet.db->mallocFailed flag is set and this
+** routine returns NULL.
 */
-SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet *p, i64 rowid){
-  struct RowSetEntry *pEntry;  /* The new entry */
-  struct RowSetEntry *pLast;   /* The last prior entry */
+static struct RowSetEntry *rowSetEntryAlloc(RowSet *p){
   assert( p!=0 );
-  if( p->nFresh==0 ){
+  if( p->nFresh==0 ){  /*OPTIMIZATION-IF-FALSE*/
+    /* We could allocate a fresh RowSetEntry each time one is needed, but it
+    ** is more efficient to pull a preallocated entry from the pool */
     struct RowSetChunk *pNew;
-    pNew = sqlite3DbMallocRaw(p->db, sizeof(*pNew));
+    pNew = sqlite3DbMallocRawNN(p->db, sizeof(*pNew));
     if( pNew==0 ){
-      return;
+      return 0;
     }
     pNew->pNextChunk = p->pChunk;
     p->pChunk = pNew;
     p->pFresh = pNew->aEntry;
     p->nFresh = ROWSET_ENTRY_PER_CHUNK;
   }
-  pEntry = p->pFresh++;
   p->nFresh--;
+  return p->pFresh++;
+}
+
+/*
+** Insert a new value into a RowSet.
+**
+** The mallocFailed flag of the database connection is set if a
+** memory allocation fails.
+*/
+SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet *p, i64 rowid){
+  struct RowSetEntry *pEntry;  /* The new entry */
+  struct RowSetEntry *pLast;   /* The last prior entry */
+
+  /* This routine is never called after sqlite3RowSetNext() */
+  assert( p!=0 && (p->rsFlags & ROWSET_NEXT)==0 );
+
+  pEntry = rowSetEntryAlloc(p);
+  if( pEntry==0 ) return;
   pEntry->v = rowid;
   pEntry->pRight = 0;
   pLast = p->pLast;
   if( pLast ){
-    if( p->isSorted && rowid<=pLast->v ){
-      p->isSorted = 0;
+    if( rowid<=pLast->v ){  /*OPTIMIZATION-IF-FALSE*/
+      /* Avoid unnecessary sorts by preserving the ROWSET_SORTED flags
+      ** where possible */
+      p->rsFlags &= ~ROWSET_SORTED;
     }
     pLast->pRight = pEntry;
   }else{
-    assert( p->pEntry==0 ); /* Fires if INSERT after SMALLEST */
     p->pEntry = pEntry;
   }
   p->pLast = pEntry;
@@ -36976,7 +45860,7 @@ SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet *p, i64 rowid){
 ** The input lists are connected via pRight pointers and are 
 ** assumed to each already be in sorted order.
 */
-static struct RowSetEntry *rowSetMerge(
+static struct RowSetEntry *rowSetEntryMerge(
   struct RowSetEntry *pA,    /* First sorted list to be merged */
   struct RowSetEntry *pB     /* Second sorted list to be merged */
 ){
@@ -36984,58 +45868,54 @@ static struct RowSetEntry *rowSetMerge(
   struct RowSetEntry *pTail;
 
   pTail = &head;
-  while( pA && pB ){
+  assert( pA!=0 && pB!=0 );
+  for(;;){
     assert( pA->pRight==0 || pA->v<=pA->pRight->v );
     assert( pB->pRight==0 || pB->v<=pB->pRight->v );
-    if( pA->v<pB->v ){
-      pTail->pRight = pA;
+    if( pA->v<=pB->v ){
+      if( pA->v<pB->v ) pTail = pTail->pRight = pA;
       pA = pA->pRight;
-      pTail = pTail->pRight;
-    }else if( pB->v<pA->v ){
-      pTail->pRight = pB;
-      pB = pB->pRight;
-      pTail = pTail->pRight;
+      if( pA==0 ){
+        pTail->pRight = pB;
+        break;
+      }
     }else{
-      pA = pA->pRight;
+      pTail = pTail->pRight = pB;
+      pB = pB->pRight;
+      if( pB==0 ){
+        pTail->pRight = pA;
+        break;
+      }
     }
   }
-  if( pA ){
-    assert( pA->pRight==0 || pA->v<=pA->pRight->v );
-    pTail->pRight = pA;
-  }else{
-    assert( pB==0 || pB->pRight==0 || pB->v<=pB->pRight->v );
-    pTail->pRight = pB;
-  }
   return head.pRight;
 }
 
 /*
-** Sort all elements on the pEntry list of the RowSet into ascending order.
+** Sort all elements on the list of RowSetEntry objects into order of
+** increasing v.
 */ 
-static void rowSetSort(RowSet *p){
+static struct RowSetEntry *rowSetEntrySort(struct RowSetEntry *pIn){
   unsigned int i;
-  struct RowSetEntry *pEntry;
-  struct RowSetEntry *aBucket[40];
+  struct RowSetEntry *pNext, *aBucket[40];
 
-  assert( p->isSorted==0 );
   memset(aBucket, 0, sizeof(aBucket));
-  while( p->pEntry ){
-    pEntry = p->pEntry;
-    p->pEntry = pEntry->pRight;
-    pEntry->pRight = 0;
+  while( pIn ){
+    pNext = pIn->pRight;
+    pIn->pRight = 0;
     for(i=0; aBucket[i]; i++){
-      pEntry = rowSetMerge(aBucket[i], pEntry);
+      pIn = rowSetEntryMerge(aBucket[i], pIn);
       aBucket[i] = 0;
     }
-    aBucket[i] = pEntry;
+    aBucket[i] = pIn;
+    pIn = pNext;
   }
-  pEntry = 0;
-  for(i=0; i<sizeof(aBucket)/sizeof(aBucket[0]); i++){
-    pEntry = rowSetMerge(pEntry, aBucket[i]);
+  pIn = aBucket[0];
+  for(i=1; i<sizeof(aBucket)/sizeof(aBucket[0]); i++){
+    if( aBucket[i]==0 ) continue;
+    pIn = pIn ? rowSetEntryMerge(pIn, aBucket[i]) : aBucket[i];
   }
-  p->pEntry = pEntry;
-  p->pLast = 0;
-  p->isSorted = 1;
+  return pIn;
 }
 
 
@@ -37085,23 +45965,29 @@ static struct RowSetEntry *rowSetNDeepTree(
 ){
   struct RowSetEntry *p;         /* Root of the new tree */
   struct RowSetEntry *pLeft;     /* Left subtree */
-  if( *ppList==0 ){
-    return 0;
-  }
-  if( iDepth==1 ){
+  if( *ppList==0 ){ /*OPTIMIZATION-IF-TRUE*/
+    /* Prevent unnecessary deep recursion when we run out of entries */
+    return 0; 
+  }
+  if( iDepth>1 ){   /*OPTIMIZATION-IF-TRUE*/
+    /* This branch causes a *balanced* tree to be generated.  A valid tree
+    ** is still generated without this branch, but the tree is wildly
+    ** unbalanced and inefficient. */
+    pLeft = rowSetNDeepTree(ppList, iDepth-1);
+    p = *ppList;
+    if( p==0 ){     /*OPTIMIZATION-IF-FALSE*/
+      /* It is safe to always return here, but the resulting tree
+      ** would be unbalanced */
+      return pLeft;
+    }
+    p->pLeft = pLeft;
+    *ppList = p->pRight;
+    p->pRight = rowSetNDeepTree(ppList, iDepth-1);
+  }else{
     p = *ppList;
     *ppList = p->pRight;
     p->pLeft = p->pRight = 0;
-    return p;
   }
-  pLeft = rowSetNDeepTree(ppList, iDepth-1);
-  p = *ppList;
-  if( p==0 ){
-    return pLeft;
-  }
-  p->pLeft = pLeft;
-  *ppList = p->pRight;
-  p->pRight = rowSetNDeepTree(ppList, iDepth-1);
   return p;
 }
 
@@ -37129,36 +46015,36 @@ static struct RowSetEntry *rowSetListToTree(struct RowSetEntry *pList){
 }
 
 /*
-** Convert the list in p->pEntry into a sorted list if it is not
-** sorted already.  If there is a binary tree on p->pTree, then
-** convert it into a list too and merge it into the p->pEntry list.
-*/
-static void rowSetToList(RowSet *p){
-  if( !p->isSorted ){
-    rowSetSort(p);
-  }
-  if( p->pTree ){
-    struct RowSetEntry *pHead, *pTail;
-    rowSetTreeToList(p->pTree, &pHead, &pTail);
-    p->pTree = 0;
-    p->pEntry = rowSetMerge(p->pEntry, pHead);
-  }
-}
-
-/*
 ** Extract the smallest element from the RowSet.
 ** Write the element into *pRowid.  Return 1 on success.  Return
 ** 0 if the RowSet is already empty.
 **
 ** After this routine has been called, the sqlite3RowSetInsert()
-** routine may not be called again.  
+** routine may not be called again.
+**
+** This routine may not be called after sqlite3RowSetTest() has
+** been used.  Older versions of RowSet allowed that, but as the
+** capability was not used by the code generator, it was removed
+** for code economy.
 */
 SQLITE_PRIVATE int sqlite3RowSetNext(RowSet *p, i64 *pRowid){
-  rowSetToList(p);
+  assert( p!=0 );
+  assert( p->pForest==0 );  /* Cannot be used with sqlite3RowSetText() */
+
+  /* Merge the forest into a single sorted list on first call */
+  if( (p->rsFlags & ROWSET_NEXT)==0 ){  /*OPTIMIZATION-IF-FALSE*/
+    if( (p->rsFlags & ROWSET_SORTED)==0 ){  /*OPTIMIZATION-IF-FALSE*/
+      p->pEntry = rowSetEntrySort(p->pEntry);
+    }
+    p->rsFlags |= ROWSET_SORTED|ROWSET_NEXT;
+  }
+
+  /* Return the next entry on the list */
   if( p->pEntry ){
     *pRowid = p->pEntry->v;
     p->pEntry = p->pEntry->pRight;
-    if( p->pEntry==0 ){
+    if( p->pEntry==0 ){ /*OPTIMIZATION-IF-TRUE*/
+      /* Free memory immediately, rather than waiting on sqlite3_finalize() */
       sqlite3RowSetClear(p);
     }
     return 1;
@@ -37168,28 +46054,70 @@ SQLITE_PRIVATE int sqlite3RowSetNext(RowSet *p, i64 *pRowid){
 }
 
 /*
-** Check to see if element iRowid was inserted into the the rowset as
+** Check to see if element iRowid was inserted into the rowset as
 ** part of any insert batch prior to iBatch.  Return 1 or 0.
+**
+** If this is the first test of a new batch and if there exist entries
+** on pRowSet->pEntry, then sort those entries into the forest at
+** pRowSet->pForest so that they can be tested.
 */
-SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, u8 iBatch, sqlite3_int64 iRowid){
-  struct RowSetEntry *p;
-  if( iBatch!=pRowSet->iBatch ){
-    if( pRowSet->pEntry ){
-      rowSetToList(pRowSet);
-      pRowSet->pTree = rowSetListToTree(pRowSet->pEntry);
+SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64 iRowid){
+  struct RowSetEntry *p, *pTree;
+
+  /* This routine is never called after sqlite3RowSetNext() */
+  assert( pRowSet!=0 && (pRowSet->rsFlags & ROWSET_NEXT)==0 );
+
+  /* Sort entries into the forest on the first test of a new batch.
+  ** To save unnecessary work, only do this when the batch number changes.
+  */
+  if( iBatch!=pRowSet->iBatch ){  /*OPTIMIZATION-IF-FALSE*/
+    p = pRowSet->pEntry;
+    if( p ){
+      struct RowSetEntry **ppPrevTree = &pRowSet->pForest;
+      if( (pRowSet->rsFlags & ROWSET_SORTED)==0 ){ /*OPTIMIZATION-IF-FALSE*/
+        /* Only sort the current set of entiries if they need it */
+        p = rowSetEntrySort(p);
+      }
+      for(pTree = pRowSet->pForest; pTree; pTree=pTree->pRight){
+        ppPrevTree = &pTree->pRight;
+        if( pTree->pLeft==0 ){
+          pTree->pLeft = rowSetListToTree(p);
+          break;
+        }else{
+          struct RowSetEntry *pAux, *pTail;
+          rowSetTreeToList(pTree->pLeft, &pAux, &pTail);
+          pTree->pLeft = 0;
+          p = rowSetEntryMerge(pAux, p);
+        }
+      }
+      if( pTree==0 ){
+        *ppPrevTree = pTree = rowSetEntryAlloc(pRowSet);
+        if( pTree ){
+          pTree->v = 0;
+          pTree->pRight = 0;
+          pTree->pLeft = rowSetListToTree(p);
+        }
+      }
       pRowSet->pEntry = 0;
       pRowSet->pLast = 0;
+      pRowSet->rsFlags |= ROWSET_SORTED;
     }
     pRowSet->iBatch = iBatch;
   }
-  p = pRowSet->pTree;
-  while( p ){
-    if( p->v<iRowid ){
-      p = p->pRight;
-    }else if( p->v>iRowid ){
-      p = p->pLeft;
-    }else{
-      return 1;
+
+  /* Test to see if the iRowid value appears anywhere in the forest.
+  ** Return 1 if it does and 0 if not.
+  */
+  for(pTree = pRowSet->pForest; pTree; pTree=pTree->pRight){
+    p = pTree->pLeft;
+    while( p ){
+      if( p->v<iRowid ){
+        p = p->pRight;
+      }else if( p->v>iRowid ){
+        p = p->pLeft;
+      }else{
+        return 1;
+      }
     }
   }
   return 0;
@@ -37218,6 +46146,7 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, u8 iBatch, sqlite3_int64 i
 ** another is writing.
 */
 #ifndef SQLITE_OMIT_DISKIO
+/* #include "sqliteInt.h" */
 /************** Include wal.h in the middle of pager.c ***********************/
 /************** Begin file wal.h *********************************************/
 /*
@@ -37236,9 +46165,16 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, u8 iBatch, sqlite3_int64 i
 ** the implementation of each function in log.c for further details.
 */
 
-#ifndef _WAL_H_
-#define _WAL_H_
+#ifndef SQLITE_WAL_H
+#define SQLITE_WAL_H
 
+/* #include "sqliteInt.h" */
+
+/* Additional values that can be added to the sync_flags argument of
+** sqlite3WalFrames():
+*/
+#define WAL_SYNC_TRANSACTIONS  0x20   /* Sync at the end of each transaction */
+#define SQLITE_SYNC_MASK       0x13   /* Mask off the SQLITE_SYNC_* values */
 
 #ifdef SQLITE_OMIT_WAL
 # define sqlite3WalOpen(x,y,z)                   0
@@ -37246,7 +46182,6 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, u8 iBatch, sqlite3_int64 i
 # define sqlite3WalClose(w,x,y,z)                0
 # define sqlite3WalBeginReadTransaction(y,z)     0
 # define sqlite3WalEndReadTransaction(z)
-# define sqlite3WalRead(v,w,x,y,z)               0
 # define sqlite3WalDbsize(y)                     0
 # define sqlite3WalBeginWriteTransaction(y)      0
 # define sqlite3WalEndWriteTransaction(x)        0
@@ -37258,6 +46193,9 @@ SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, u8 iBatch, sqlite3_int64 i
 # define sqlite3WalCallback(z)                   0
 # define sqlite3WalExclusiveMode(y,z)            0
 # define sqlite3WalHeapMemory(z)                 0
+# define sqlite3WalFramesize(z)                  0
+# define sqlite3WalFindFrame(x,y,z)              0
+# define sqlite3WalFile(x)                       0
 #else
 
 #define WAL_SAVEPOINT_NDATA 4
@@ -37285,7 +46223,8 @@ SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *);
 SQLITE_PRIVATE void sqlite3WalEndReadTransaction(Wal *pWal);
 
 /* Read a page from the write-ahead log, if it is present. */
-SQLITE_PRIVATE int sqlite3WalRead(Wal *pWal, Pgno pgno, int *pInWal, int nOut, u8 *pOut);
+SQLITE_PRIVATE int sqlite3WalFindFrame(Wal *, Pgno, u32 *);
+SQLITE_PRIVATE int sqlite3WalReadFrame(Wal *, u32, int, u8 *);
 
 /* If the WAL is not empty, return the size of the database. */
 SQLITE_PRIVATE Pgno sqlite3WalDbsize(Wal *pWal);
@@ -37339,8 +46278,23 @@ SQLITE_PRIVATE int sqlite3WalExclusiveMode(Wal *pWal, int op);
 */
 SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal);
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot);
+SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot);
+#endif
+
+#ifdef SQLITE_ENABLE_ZIPVFS
+/* If the WAL file is not empty, return the number of bytes of content
+** stored in each frame (i.e. the db page-size when the WAL was created).
+*/
+SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal);
+#endif
+
+/* Return the sqlite3_file object for the WAL file */
+SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal);
+
 #endif /* ifndef SQLITE_OMIT_WAL */
-#endif /* _WAL_H_ */
+#endif /* SQLITE_WAL_H */
 
 /************** End of wal.h *************************************************/
 /************** Continuing where we left off in pager.c **********************/
@@ -37398,13 +46352,13 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal);
 ** 
 ** Definition: Two databases (or the same database at two points it time)
 ** are said to be "logically equivalent" if they give the same answer to
-** all queries.  Note in particular the the content of freelist leaf
-** pages can be changed arbitarily without effecting the logical equivalence
+** all queries.  Note in particular the content of freelist leaf
+** pages can be changed arbitrarily without affecting the logical equivalence
 ** of the database.
 ** 
 ** (7) At any time, if any subset, including the empty set and the total set,
 **     of the unsynced changes to a rollback journal are removed and the 
-**     journal is rolled back, the resulting database file will be logical
+**     journal is rolled back, the resulting database file will be logically
 **     equivalent to the database file at the beginning of the transaction.
 ** 
 ** (8) When a transaction is rolled back, the xTruncate method of the VFS
@@ -37596,7 +46550,7 @@ int sqlite3PagerTrace=1;  /* True to enable tracing */
 **    * A write transaction is active.
 **    * An EXCLUSIVE or greater lock is held on the database file.
 **    * All writing and syncing of journal and database data has finished.
-**      If no error occured, all that remains is to finalize the journal to
+**      If no error occurred, all that remains is to finalize the journal to
 **      commit the transaction. If an error did occur, the caller will need
 **      to rollback the transaction. 
 **
@@ -37701,7 +46655,7 @@ int sqlite3PagerTrace=1;  /* True to enable tracing */
 **
 ** The exception is when the database file is unlocked as the pager moves
 ** from ERROR to OPEN state. At this point there may be a hot-journal file 
-** in the file-system that needs to be rolled back (as part of a OPEN->SHARED
+** in the file-system that needs to be rolled back (as part of an OPEN->SHARED
 ** transition, by the same pager or any other). If the call to xUnlock()
 ** fails at this point and the pager is left holding an EXCLUSIVE lock, this
 ** can confuse the call to xCheckReservedLock() call made later as part
@@ -37751,6 +46705,7 @@ int sqlite3PagerTrace=1;  /* True to enable tracing */
 */
 #define MAX_SECTOR_SIZE 0x10000
 
+
 /*
 ** An instance of the following structure is allocated for each active
 ** savepoint and statement transaction in the system. All such structures
@@ -37777,7 +46732,14 @@ struct PagerSavepoint {
 };
 
 /*
-** A open page cache is an instance of struct Pager. A description of
+** Bits of the Pager.doNotSpill flag.  See further description below.
+*/
+#define SPILLFLAG_OFF         0x01 /* Never spill cache.  Set via pragma */
+#define SPILLFLAG_ROLLBACK    0x02 /* Current rolling back, so do not spill */
+#define SPILLFLAG_NOSYNC      0x04 /* Spill is ok, but do not sync */
+
+/*
+** An open page cache is an instance of struct Pager. A description of
 ** some of the more important member variables follows:
 **
 ** eState
@@ -37842,23 +46804,25 @@ struct PagerSavepoint {
 **   journal file from being successfully finalized, the setMaster flag
 **   is cleared anyway (and the pager will move to ERROR state).
 **
-** doNotSpill, doNotSyncSpill
+** doNotSpill
 **
-**   These two boolean variables control the behaviour of cache-spills
-**   (calls made by the pcache module to the pagerStress() routine to
-**   write cached data to the file-system in order to free up memory).
+**   This variables control the behavior of cache-spills  (calls made by
+**   the pcache module to the pagerStress() routine to write cached data
+**   to the file-system in order to free up memory).
 **
-**   When doNotSpill is non-zero, writing to the database from pagerStress()
-**   is disabled altogether. This is done in a very obscure case that
+**   When bits SPILLFLAG_OFF or SPILLFLAG_ROLLBACK of doNotSpill are set,
+**   writing to the database from pagerStress() is disabled altogether.
+**   The SPILLFLAG_ROLLBACK case is done in a very obscure case that
 **   comes up during savepoint rollback that requires the pcache module
 **   to allocate a new page to prevent the journal file from being written
-**   while it is being traversed by code in pager_playback().
+**   while it is being traversed by code in pager_playback().  The SPILLFLAG_OFF
+**   case is a user preference.
 ** 
-**   If doNotSyncSpill is non-zero, writing to the database from pagerStress()
-**   is permitted, but syncing the journal file is not. This flag is set
-**   by sqlite3PagerWrite() when the file-system sector-size is larger than
-**   the database page-size in order to prevent a journal sync from happening 
-**   in between the journalling of two pages on the same sector. 
+**   If the SPILLFLAG_NOSYNC bit is set, writing to the database from
+**   pagerStress() is permitted, but syncing the journal file is not.
+**   This flag is set by sqlite3PagerWrite() when the file-system sector-size
+**   is larger than the database page-size in order to prevent a journal sync
+**   from happening in between the journalling of two pages on the same sector. 
 **
 ** subjInMemory
 **
@@ -37935,18 +46899,20 @@ struct Pager {
   u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */
   u8 journalMode;             /* One of the PAGER_JOURNALMODE_* values */
   u8 useJournal;              /* Use a rollback journal on this file */
-  u8 noReadlock;              /* Do not bother to obtain readlocks */
   u8 noSync;                  /* Do not sync the journal if true */
   u8 fullSync;                /* Do extra syncs of the journal for robustness */
+  u8 extraSync;               /* sync directory after journal delete */
   u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
+  u8 walSyncFlags;            /* SYNC_NORMAL or SYNC_FULL for wal writes */
   u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
-  u8 tempFile;                /* zFilename is a temporary file */
+  u8 tempFile;                /* zFilename is a temporary or immutable file */
+  u8 noLock;                  /* Do not lock (except in WAL mode) */
   u8 readOnly;                /* True for a read-only database */
   u8 memDb;                   /* True to inhibit all file I/O */
 
   /**************************************************************************
   ** The following block contains those class members that change during
-  ** routine opertion.  Class members not in this block are either fixed
+  ** routine operation.  Class members not in this block are either fixed
   ** when the pager is first created or else only change when there is a
   ** significant mode change (such as changing the page_size, locking_mode,
   ** or the journal_mode).  From another view, these class members describe
@@ -37958,8 +46924,9 @@ struct Pager {
   u8 changeCountDone;         /* Set after incrementing the change-counter */
   u8 setMaster;               /* True if a m-j name has been written to jrnl */
   u8 doNotSpill;              /* Do not spill the cache when non-zero */
-  u8 doNotSyncSpill;          /* Do not do a spill that requires jrnl sync */
   u8 subjInMemory;            /* True to use in-memory sub-journals */
+  u8 bUseFetch;               /* True to use xFetch() */
+  u8 hasHeldSharedLock;       /* True if a shared lock has ever been held */
   Pgno dbSize;                /* Number of pages in the database */
   Pgno dbOrigSize;            /* dbSize before the current transaction */
   Pgno dbFileSize;            /* Number of pages in the database file */
@@ -37977,7 +46944,12 @@ struct Pager {
   sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */
   PagerSavepoint *aSavepoint; /* Array of active savepoints */
   int nSavepoint;             /* Number of elements in aSavepoint[] */
+  u32 iDataVersion;           /* Changes whenever database content changes */
   char dbFileVers[16];        /* Changes whenever database file changes */
+
+  int nMmapOut;               /* Number of mmap pages currently outstanding */
+  sqlite3_int64 szMmap;       /* Desired maximum mmap size */
+  PgHdr *pMmapFreelist;       /* List of free mmap page headers (pDirty) */
   /*
   ** End of the routinely-changing class members
   ***************************************************************************/
@@ -37993,9 +46965,9 @@ struct Pager {
   char *zJournal;             /* Name of the journal file */
   int (*xBusyHandler)(void*); /* Function to call when busy */
   void *pBusyHandlerArg;      /* Context argument for xBusyHandler */
-  int nHit, nMiss;            /* Total cache hits and misses */
+  int aStat[3];               /* Total cache hits, misses and writes */
 #ifdef SQLITE_TEST
-  int nRead, nWrite;          /* Database pages read/written */
+  int nRead;                  /* Database pages read */
 #endif
   void (*xReiniter)(DbPage*); /* Call this routine when reloading pages */
 #ifdef SQLITE_HAS_CODEC
@@ -38013,6 +46985,15 @@ struct Pager {
 };
 
 /*
+** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains
+** the values accessed by passing SQLITE_DBSTATUS_CACHE_HIT, CACHE_MISS 
+** or CACHE_WRITE to sqlite3_db_status().
+*/
+#define PAGER_STAT_HIT   0
+#define PAGER_STAT_MISS  1
+#define PAGER_STAT_WRITE 2
+
+/*
 ** The following global variables hold counters used for
 ** testing purposes only.  These variables do not exist in
 ** a non-testing build.  These variables are not thread-safe.
@@ -38080,6 +47061,16 @@ static const unsigned char aJournalMagic[] = {
 #endif
 
 /*
+** The macro USEFETCH is true if we are allowed to use the xFetch and xUnfetch
+** interfaces to access the database using memory-mapped I/O.
+*/
+#if SQLITE_MAX_MMAP_SIZE>0
+# define USEFETCH(x) ((x)->bUseFetch)
+#else
+# define USEFETCH(x) 0
+#endif
+
+/*
 ** The maximum legal page number is (2^31 - 1).
 */
 #define PAGER_MAX_PGNO 2147483647
@@ -38096,7 +47087,7 @@ static const unsigned char aJournalMagic[] = {
 **
 **   if( pPager->jfd->pMethods ){ ...
 */
-#define isOpen(pFd) ((pFd)->pMethods)
+#define isOpen(pFd) ((pFd)->pMethods!=0)
 
 /*
 ** Return true if this pager uses a write-ahead log instead of the usual
@@ -38109,7 +47100,7 @@ static int pagerUseWal(Pager *pPager){
 #else
 # define pagerUseWal(x) 0
 # define pagerRollbackWal(x) 0
-# define pagerWalFrames(v,w,x,y,z) 0
+# define pagerWalFrames(v,w,x,y) 0
 # define pagerOpenWalIfPresent(z) SQLITE_OK
 # define pagerBeginReadTransaction(z) SQLITE_OK
 #endif
@@ -38158,6 +47149,7 @@ static int assert_pager_state(Pager *p){
   ** state.
   */
   if( MEMDB ){
+    assert( !isOpen(p->fd) );
     assert( p->noSync );
     assert( p->journalMode==PAGER_JOURNALMODE_OFF 
          || p->journalMode==PAGER_JOURNALMODE_MEMORY 
@@ -38182,7 +47174,7 @@ static int assert_pager_state(Pager *p){
     case PAGER_READER:
       assert( pPager->errCode==SQLITE_OK );
       assert( p->eLock!=UNKNOWN_LOCK );
-      assert( p->eLock>=SHARED_LOCK || p->noReadlock );
+      assert( p->eLock>=SHARED_LOCK );
       break;
 
     case PAGER_WRITER_LOCKED:
@@ -38244,7 +47236,7 @@ static int assert_pager_state(Pager *p){
       ** back to OPEN state.
       */
       assert( pPager->errCode!=SQLITE_OK );
-      assert( sqlite3PcacheRefCount(pPager->pPCache)>0 );
+      assert( sqlite3PcacheRefCount(pPager->pPCache)>0 || pPager->tempFile );
       break;
   }
 
@@ -38313,24 +47305,27 @@ static char *print_pager_state(Pager *p){
 **     PagerSavepoint.pInSavepoint.
 */
 static int subjRequiresPage(PgHdr *pPg){
-  Pgno pgno = pPg->pgno;
   Pager *pPager = pPg->pPager;
+  PagerSavepoint *p;
+  Pgno pgno = pPg->pgno;
   int i;
   for(i=0; i<pPager->nSavepoint; i++){
-    PagerSavepoint *p = &pPager->aSavepoint[i];
-    if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
+    p = &pPager->aSavepoint[i];
+    if( p->nOrig>=pgno && 0==sqlite3BitvecTestNotNull(p->pInSavepoint, pgno) ){
       return 1;
     }
   }
   return 0;
 }
 
+#ifdef SQLITE_DEBUG
 /*
 ** Return true if the page is already in the journal file.
 */
-static int pageInJournal(PgHdr *pPg){
-  return sqlite3BitvecTest(pPg->pPager->pInJournal, pPg->pgno);
+static int pageInJournal(Pager *pPager, PgHdr *pPg){
+  return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);
 }
+#endif
 
 /*
 ** Read a 32-bit integer from the given file descriptor.  Store the integer
@@ -38381,7 +47376,7 @@ static int pagerUnlockDb(Pager *pPager, int eLock){
   assert( eLock!=NO_LOCK || pagerUseWal(pPager)==0 );
   if( isOpen(pPager->fd) ){
     assert( pPager->eLock>=eLock );
-    rc = sqlite3OsUnlock(pPager->fd, eLock);
+    rc = pPager->noLock ? SQLITE_OK : sqlite3OsUnlock(pPager->fd, eLock);
     if( pPager->eLock!=UNKNOWN_LOCK ){
       pPager->eLock = (u8)eLock;
     }
@@ -38405,7 +47400,7 @@ static int pagerLockDb(Pager *pPager, int eLock){
 
   assert( eLock==SHARED_LOCK || eLock==RESERVED_LOCK || eLock==EXCLUSIVE_LOCK );
   if( pPager->eLock<eLock || pPager->eLock==UNKNOWN_LOCK ){
-    rc = sqlite3OsLock(pPager->fd, eLock);
+    rc = pPager->noLock ? SQLITE_OK : sqlite3OsLock(pPager->fd, eLock);
     if( rc==SQLITE_OK && (pPager->eLock!=UNKNOWN_LOCK||eLock==EXCLUSIVE_LOCK) ){
       pPager->eLock = (u8)eLock;
       IOTRACE(("LOCK %p %d\n", pPager, eLock))
@@ -38453,6 +47448,8 @@ static int jrnlBufferSize(Pager *pPager){
 
   return JOURNAL_HDR_SZ(pPager) + JOURNAL_PG_SZ(pPager);
 }
+#else
+# define jrnlBufferSize(x) 0
 #endif
 
 /*
@@ -38536,6 +47533,7 @@ static int readMasterJournal(sqlite3_file *pJrnl, char *zMaster, u32 nMaster){
    || szJ<16
    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-16, &len))
    || len>=nMaster 
+   || len==0 
    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-12, &cksum))
    || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8))
    || memcmp(aMagic, aJournalMagic, 8)
@@ -38612,6 +47610,7 @@ static i64 journalHdrOffset(Pager *pPager){
 static int zeroJournalHdr(Pager *pPager, int doTruncate){
   int rc = SQLITE_OK;                               /* Return code */
   assert( isOpen(pPager->jfd) );
+  assert( !sqlite3JournalIsInMemory(pPager->jfd) );
   if( pPager->journalOff ){
     const i64 iLimit = pPager->journalSizeLimit;    /* Local cache of jsl */
 
@@ -38713,7 +47712,7 @@ static int writeJournalHdr(Pager *pPager){
     memset(zHeader, 0, sizeof(aJournalMagic)+4);
   }
 
-  /* The random check-hash initialiser */ 
+  /* The random check-hash initializer */ 
   sqlite3_randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
   put32bits(&zHeader[sizeof(aJournalMagic)+4], pPager->cksumInit);
   /* The initial database size */
@@ -38913,12 +47912,11 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){
 
   if( !zMaster 
    || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
-   || pPager->journalMode==PAGER_JOURNALMODE_OFF 
+   || !isOpen(pPager->jfd)
   ){
     return SQLITE_OK;
   }
   pPager->setMaster = 1;
-  assert( isOpen(pPager->jfd) );
   assert( pPager->journalHdr <= pPager->journalOff );
 
   /* Calculate the length in bytes and the checksum of zMaster */
@@ -38942,7 +47940,8 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){
    || (0 != (rc = sqlite3OsWrite(pPager->jfd, zMaster, nMaster, iHdrOff+4)))
    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster, nMaster)))
    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster+4, cksum)))
-   || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8, iHdrOff+4+nMaster+8)))
+   || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8,
+                                 iHdrOff+4+nMaster+8)))
   ){
     return rc;
   }
@@ -38967,29 +47966,23 @@ static int writeMasterJournal(Pager *pPager, const char *zMaster){
 }
 
 /*
-** Find a page in the hash table given its page number. Return
-** a pointer to the page or NULL if the requested page is not 
-** already in memory.
-*/
-static PgHdr *pager_lookup(Pager *pPager, Pgno pgno){
-  PgHdr *p;                         /* Return value */
-
-  /* It is not possible for a call to PcacheFetch() with createFlag==0 to
-  ** fail, since no attempt to allocate dynamic memory will be made.
-  */
-  (void)sqlite3PcacheFetch(pPager->pPCache, pgno, 0, &p);
-  return p;
-}
-
-/*
 ** Discard the entire contents of the in-memory page-cache.
 */
 static void pager_reset(Pager *pPager){
+  pPager->iDataVersion++;
   sqlite3BackupRestart(pPager->pBackup);
   sqlite3PcacheClear(pPager->pPCache);
 }
 
 /*
+** Return the pPager->iDataVersion value
+*/
+SQLITE_PRIVATE u32 sqlite3PagerDataVersion(Pager *pPager){
+  assert( pPager->eState>PAGER_OPEN );
+  return pPager->iDataVersion;
+}
+
+/*
 ** Free all structures in the Pager.aSavepoint[] array and set both
 ** Pager.aSavepoint and Pager.nSavepoint to zero. Close the sub-journal
 ** if it is open and the pager is not in exclusive mode.
@@ -38999,7 +47992,7 @@ static void releaseAllSavepoints(Pager *pPager){
   for(ii=0; ii<pPager->nSavepoint; ii++){
     sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);
   }
-  if( !pPager->exclusiveMode || sqlite3IsMemJournal(pPager->sjfd) ){
+  if( !pPager->exclusiveMode || sqlite3JournalIsInMemory(pPager->sjfd) ){
     sqlite3OsClose(pPager->sjfd);
   }
   sqlite3_free(pPager->aSavepoint);
@@ -39105,11 +48098,16 @@ static void pager_unlock(Pager *pPager){
   ** it can safely move back to PAGER_OPEN state. This happens in both
   ** normal and exclusive-locking mode.
   */
+  assert( pPager->errCode==SQLITE_OK || !MEMDB );
   if( pPager->errCode ){
-    assert( !MEMDB );
-    pager_reset(pPager);
-    pPager->changeCountDone = pPager->tempFile;
-    pPager->eState = PAGER_OPEN;
+    if( pPager->tempFile==0 ){
+      pager_reset(pPager);
+      pPager->changeCountDone = 0;
+      pPager->eState = PAGER_OPEN;
+    }else{
+      pPager->eState = (isOpen(pPager->jfd) ? PAGER_OPEN : PAGER_READER);
+    }
+    if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
     pPager->errCode = SQLITE_OK;
   }
 
@@ -39152,6 +48150,31 @@ static int pager_error(Pager *pPager, int rc){
   return rc;
 }
 
+static int pager_truncate(Pager *pPager, Pgno nPage);
+
+/*
+** The write transaction open on pPager is being committed (bCommit==1)
+** or rolled back (bCommit==0).
+**
+** Return TRUE if and only if all dirty pages should be flushed to disk.
+**
+** Rules:
+**
+**   *  For non-TEMP databases, always sync to disk.  This is necessary
+**      for transactions to be durable.
+**
+**   *  Sync TEMP database only on a COMMIT (not a ROLLBACK) when the backing
+**      file has been created already (via a spill on pagerStress()) and
+**      when the number of dirty pages in memory exceeds 25% of the total
+**      cache size.
+*/
+static int pagerFlushOnCommit(Pager *pPager, int bCommit){
+  if( pPager->tempFile==0 ) return 1;
+  if( !bCommit ) return 0;
+  if( !isOpen(pPager->fd) ) return 0;
+  return (sqlite3PCachePercentDirty(pPager->pPCache)>=25);
+}
+
 /*
 ** This routine ends a transaction. A transaction is usually ended by 
 ** either a COMMIT or a ROLLBACK operation. This routine may be called 
@@ -39205,7 +48228,7 @@ static int pager_error(Pager *pPager, int rc){
 ** to the first error encountered (the journal finalization one) is
 ** returned.
 */
-static int pager_end_transaction(Pager *pPager, int hasMaster){
+static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
   int rc = SQLITE_OK;      /* Error code from journal finalization operation */
   int rc2 = SQLITE_OK;     /* Error code from db file unlock operation */
 
@@ -39234,34 +48257,44 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
     assert( !pagerUseWal(pPager) );
 
     /* Finalize the journal file. */
-    if( sqlite3IsMemJournal(pPager->jfd) ){
-      assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY );
+    if( sqlite3JournalIsInMemory(pPager->jfd) ){
+      /* assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ); */
       sqlite3OsClose(pPager->jfd);
     }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){
       if( pPager->journalOff==0 ){
         rc = SQLITE_OK;
       }else{
         rc = sqlite3OsTruncate(pPager->jfd, 0);
+        if( rc==SQLITE_OK && pPager->fullSync ){
+          /* Make sure the new file size is written into the inode right away.
+          ** Otherwise the journal might resurrect following a power loss and
+          ** cause the last transaction to roll back.  See
+          ** https://bugzilla.mozilla.org/show_bug.cgi?id=1072773
+          */
+          rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags);
+        }
       }
       pPager->journalOff = 0;
     }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST
       || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)
     ){
-      rc = zeroJournalHdr(pPager, hasMaster);
+      rc = zeroJournalHdr(pPager, hasMaster||pPager->tempFile);
       pPager->journalOff = 0;
     }else{
       /* This branch may be executed with Pager.journalMode==MEMORY if
       ** a hot-journal was just rolled back. In this case the journal
       ** file should be closed and deleted. If this connection writes to
-      ** the database file, it will do so using an in-memory journal. 
+      ** the database file, it will do so using an in-memory journal.
       */
+      int bDelete = !pPager->tempFile;
+      assert( sqlite3JournalIsInMemory(pPager->jfd)==0 );
       assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
            || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
            || pPager->journalMode==PAGER_JOURNALMODE_WAL 
       );
       sqlite3OsClose(pPager->jfd);
-      if( !pPager->tempFile ){
-        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
+      if( bDelete ){
+        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, pPager->extraSync);
       }
     }
   }
@@ -39269,10 +48302,10 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
 #ifdef SQLITE_CHECK_PAGES
   sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash);
   if( pPager->dbSize==0 && sqlite3PcacheRefCount(pPager->pPCache)>0 ){
-    PgHdr *p = pager_lookup(pPager, 1);
+    PgHdr *p = sqlite3PagerLookup(pPager, 1);
     if( p ){
       p->pageHash = 0;
-      sqlite3PagerUnref(p);
+      sqlite3PagerUnrefNotNull(p);
     }
   }
 #endif
@@ -39280,8 +48313,14 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
   sqlite3BitvecDestroy(pPager->pInJournal);
   pPager->pInJournal = 0;
   pPager->nRec = 0;
-  sqlite3PcacheCleanAll(pPager->pPCache);
-  sqlite3PcacheTruncate(pPager->pPCache, pPager->dbSize);
+  if( rc==SQLITE_OK ){
+    if( pagerFlushOnCommit(pPager, bCommit) ){
+      sqlite3PcacheCleanAll(pPager->pPCache);
+    }else{
+      sqlite3PcacheClearWritable(pPager->pPCache);
+    }
+    sqlite3PcacheTruncate(pPager->pPCache, pPager->dbSize);
+  }
 
   if( pagerUseWal(pPager) ){
     /* Drop the WAL write-lock, if any. Also, if the connection was in 
@@ -39290,7 +48329,22 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
     */
     rc2 = sqlite3WalEndWriteTransaction(pPager->pWal);
     assert( rc2==SQLITE_OK );
+  }else if( rc==SQLITE_OK && bCommit && pPager->dbFileSize>pPager->dbSize ){
+    /* This branch is taken when committing a transaction in rollback-journal
+    ** mode if the database file on disk is larger than the database image.
+    ** At this point the journal has been finalized and the transaction 
+    ** successfully committed, but the EXCLUSIVE lock is still held on the
+    ** file. So it is safe to truncate the database file to its minimum
+    ** required size.  */
+    assert( pPager->eLock==EXCLUSIVE_LOCK );
+    rc = pager_truncate(pPager, pPager->dbSize);
   }
+
+  if( rc==SQLITE_OK && bCommit && isOpen(pPager->fd) ){
+    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_COMMIT_PHASETWO, 0);
+    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+  }
+
   if( !pPager->exclusiveMode 
    && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))
   ){
@@ -39329,7 +48383,7 @@ static void pagerUnlockAndRollback(Pager *pPager){
       sqlite3EndBenignMalloc();
     }else if( !pPager->exclusiveMode ){
       assert( pPager->eState==PAGER_READER );
-      pager_end_transaction(pPager, 0);
+      pager_end_transaction(pPager, 0, 0);
     }
   }
   pager_unlock(pPager);
@@ -39379,6 +48433,20 @@ static void pagerReportSize(Pager *pPager){
 # define pagerReportSize(X)     /* No-op if we do not support a codec */
 #endif
 
+#ifdef SQLITE_HAS_CODEC
+/*
+** Make sure the number of reserved bits is the same in the destination
+** pager as it is in the source.  This comes up when a VACUUM changes the
+** number of reserved bits to the "optimal" amount.
+*/
+SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager *pDest, Pager *pSrc){
+  if( pDest->nReserve!=pSrc->nReserve ){
+    pDest->nReserve = pSrc->nReserve;
+    pagerReportSize(pDest);
+  }
+}
+#endif
+
 /*
 ** Read a single page from either the journal file (if isMainJrnl==1) or
 ** from the sub-journal (if isMainJrnl==0) and playback that page.
@@ -39481,7 +48549,7 @@ static int pager_playback_one_page(
     }
   }
 
-  /* If this page has already been played by before during the current
+  /* If this page has already been played back before during the current
   ** rollback, then don't bother to play it back again.
   */
   if( pDone && (rc = sqlite3BitvecSet(pDone, pgno))!=SQLITE_OK ){
@@ -39533,10 +48601,10 @@ static int pager_playback_one_page(
   if( pagerUseWal(pPager) ){
     pPg = 0;
   }else{
-    pPg = pager_lookup(pPager, pgno);
+    pPg = sqlite3PagerLookup(pPager, pgno);
   }
   assert( pPg || !MEMDB );
-  assert( pPager->eState!=PAGER_OPEN || pPg==0 );
+  assert( pPager->eState!=PAGER_OPEN || pPg==0 || pPager->tempFile );
   PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n",
            PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData),
            (isMainJrnl?"main-journal":"sub-journal")
@@ -39553,14 +48621,14 @@ static int pager_playback_one_page(
     i64 ofst = (pgno-1)*(i64)pPager->pageSize;
     testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
     assert( !pagerUseWal(pPager) );
-    rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst);
+    rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
     if( pgno>pPager->dbFileSize ){
       pPager->dbFileSize = pgno;
     }
     if( pPager->pBackup ){
-      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM);
+      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
-      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM, aData);
+      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT, aData);
     }
   }else if( !isMainJrnl && pPg==0 ){
     /* If this is a rollback of a savepoint and data was not written to
@@ -39580,13 +48648,12 @@ static int pager_playback_one_page(
     ** requiring a journal-sync before it is written.
     */
     assert( isSavepnt );
-    assert( pPager->doNotSpill==0 );
-    pPager->doNotSpill++;
-    rc = sqlite3PagerAcquire(pPager, pgno, &pPg, 1);
-    assert( pPager->doNotSpill==1 );
-    pPager->doNotSpill--;
+    assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 );
+    pPager->doNotSpill |= SPILLFLAG_ROLLBACK;
+    rc = sqlite3PagerGet(pPager, pgno, &pPg, 1);
+    assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 );
+    pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK;
     if( rc!=SQLITE_OK ) return rc;
-    pPg->flags &= ~PGHDR_NEED_READ;
     sqlite3PcacheMakeDirty(pPg);
   }
   if( pPg ){
@@ -39600,29 +48667,10 @@ static int pager_playback_one_page(
     pData = pPg->pData;
     memcpy(pData, (u8*)aData, pPager->pageSize);
     pPager->xReiniter(pPg);
-    if( isMainJrnl && (!isSavepnt || *pOffset<=pPager->journalHdr) ){
-      /* If the contents of this page were just restored from the main 
-      ** journal file, then its content must be as they were when the 
-      ** transaction was first opened. In this case we can mark the page
-      ** as clean, since there will be no need to write it out to the
-      ** database.
-      **
-      ** There is one exception to this rule. If the page is being rolled
-      ** back as part of a savepoint (or statement) rollback from an 
-      ** unsynced portion of the main journal file, then it is not safe
-      ** to mark the page as clean. This is because marking the page as
-      ** clean will clear the PGHDR_NEED_SYNC flag. Since the page is
-      ** already in the journal file (recorded in Pager.pInJournal) and
-      ** the PGHDR_NEED_SYNC flag is cleared, if the page is written to
-      ** again within this transaction, it will be marked as dirty but
-      ** the PGHDR_NEED_SYNC flag will not be set. It could then potentially
-      ** be written out into the database file before its journal file
-      ** segment is synced. If a crash occurs during or following this,
-      ** database corruption may ensue.
-      */
-      assert( !pagerUseWal(pPager) );
-      sqlite3PcacheMakeClean(pPg);
-    }
+    /* It used to be that sqlite3PcacheMakeClean(pPg) was called here.  But
+    ** that call was dangerous and had no detectable benefit since the cache
+    ** is normally cleaned by sqlite3PcacheCleanAll() after rollback and so
+    ** has been removed. */
     pager_set_pagehash(pPg);
 
     /* If this was page 1, then restore the value of Pager.dbFileVers.
@@ -39632,7 +48680,7 @@ static int pager_playback_one_page(
     }
 
     /* Decode the page just read from disk */
-    CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM);
+    CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM_BKPT);
     sqlite3PcacheRelease(pPg);
   }
   return rc;
@@ -39698,7 +48746,7 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   pMaster = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
   pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
   if( !pMaster ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }else{
     const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);
     rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);
@@ -39713,9 +48761,9 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   rc = sqlite3OsFileSize(pMaster, &nMasterJournal);
   if( rc!=SQLITE_OK ) goto delmaster_out;
   nMasterPtr = pVfs->mxPathname+1;
-  zMasterJournal = sqlite3Malloc((int)nMasterJournal + nMasterPtr + 1);
+  zMasterJournal = sqlite3Malloc(nMasterJournal + nMasterPtr + 1);
   if( !zMasterJournal ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto delmaster_out;
   }
   zMasterPtr = &zMasterJournal[nMasterJournal+1];
@@ -39782,7 +48830,7 @@ delmaster_out:
 ** If the file on disk is currently larger than nPage pages, then use the VFS
 ** xTruncate() method to truncate it.
 **
-** Or, it might might be the case that the file on disk is smaller than 
+** Or, it might be the case that the file on disk is smaller than 
 ** nPage pages. Some operating system implementations can get confused if 
 ** you try to truncate a file to some size that is larger than it 
 ** currently is, so detect this case and write a single zero byte to 
@@ -39808,10 +48856,9 @@ static int pager_truncate(Pager *pPager, Pgno nPage){
     if( rc==SQLITE_OK && currentSize!=newSize ){
       if( currentSize>newSize ){
         rc = sqlite3OsTruncate(pPager->fd, newSize);
-      }else{
+      }else if( (currentSize+szPage)<=newSize ){
         char *pTmp = pPager->pTmpSpace;
         memset(pTmp, 0, szPage);
-        testcase( (newSize-szPage) <  currentSize );
         testcase( (newSize-szPage) == currentSize );
         testcase( (newSize-szPage) >  currentSize );
         rc = sqlite3OsWrite(pPager->fd, pTmp, szPage, newSize-szPage);
@@ -39825,9 +48872,24 @@ static int pager_truncate(Pager *pPager, Pgno nPage){
 }
 
 /*
+** Return a sanitized version of the sector-size of OS file pFile. The
+** return value is guaranteed to lie between 32 and MAX_SECTOR_SIZE.
+*/
+SQLITE_PRIVATE int sqlite3SectorSize(sqlite3_file *pFile){
+  int iRet = sqlite3OsSectorSize(pFile);
+  if( iRet<32 ){
+    iRet = 512;
+  }else if( iRet>MAX_SECTOR_SIZE ){
+    assert( MAX_SECTOR_SIZE>=512 );
+    iRet = MAX_SECTOR_SIZE;
+  }
+  return iRet;
+}
+
+/*
 ** Set the value of the Pager.sectorSize variable for the given
 ** pager based on the value returned by the xSectorSize method
-** of the open database file. The sector size will be used used 
+** of the open database file. The sector size will be used 
 ** to determine the size and alignment of journal header and 
 ** master journal pointers within created journal files.
 **
@@ -39837,23 +48899,29 @@ static int pager_truncate(Pager *pPager, Pgno nPage){
 ** the value returned by the xSectorSize() method rounded up to 32 if
 ** it is less than 32, or rounded down to MAX_SECTOR_SIZE if it
 ** is greater than MAX_SECTOR_SIZE.
+**
+** If the file has the SQLITE_IOCAP_POWERSAFE_OVERWRITE property, then set
+** the effective sector size to its minimum value (512).  The purpose of
+** pPager->sectorSize is to define the "blast radius" of bytes that
+** might change if a crash occurs while writing to a single byte in
+** that range.  But with POWERSAFE_OVERWRITE, the blast radius is zero
+** (that is what POWERSAFE_OVERWRITE means), so we minimize the sector
+** size.  For backwards compatibility of the rollback journal file format,
+** we cannot reduce the effective sector size below 512.
 */
 static void setSectorSize(Pager *pPager){
   assert( isOpen(pPager->fd) || pPager->tempFile );
 
-  if( !pPager->tempFile ){
+  if( pPager->tempFile
+   || (sqlite3OsDeviceCharacteristics(pPager->fd) & 
+              SQLITE_IOCAP_POWERSAFE_OVERWRITE)!=0
+  ){
     /* Sector size doesn't matter for temporary files. Also, the file
     ** may not have been opened yet, in which case the OsSectorSize()
-    ** call will segfault.
-    */
-    pPager->sectorSize = sqlite3OsSectorSize(pPager->fd);
-  }
-  if( pPager->sectorSize<32 ){
+    ** call will segfault. */
     pPager->sectorSize = 512;
-  }
-  if( pPager->sectorSize>MAX_SECTOR_SIZE ){
-    assert( MAX_SECTOR_SIZE>=512 );
-    pPager->sectorSize = MAX_SECTOR_SIZE;
+  }else{
+    pPager->sectorSize = sqlite3SectorSize(pPager->fd);
   }
 }
 
@@ -39924,6 +48992,7 @@ static int pager_playback(Pager *pPager, int isHot){
   int res = 1;             /* Value returned by sqlite3OsAccess() */
   char *zMaster = 0;       /* Name of master journal file if any */
   int needPagerReset;      /* True to reset page prior to first page rollback */
+  int nPlayback = 0;       /* Total number of pages restored from journal */
 
   /* Figure out how many records are in the journal.  Abort early if
   ** the journal is empty.
@@ -39942,7 +49011,7 @@ static int pager_playback(Pager *pPager, int isHot){
   ** TODO: Technically the following is an error because it assumes that
   ** buffer Pager.pTmpSpace is (mxPathname+1) bytes or larger. i.e. that
   ** (pPager->pageSize >= pPager->pVfs->mxPathname+1). Using os_unix.c,
-  **  mxPathname is 512, which is the same as the minimum allowable value
+  ** mxPathname is 512, which is the same as the minimum allowable value
   ** for pageSize.
   */
   zMaster = pPager->pTmpSpace;
@@ -40024,7 +49093,9 @@ static int pager_playback(Pager *pPager, int isHot){
         needPagerReset = 0;
       }
       rc = pager_playback_one_page(pPager,&pPager->journalOff,0,1,0);
-      if( rc!=SQLITE_OK ){
+      if( rc==SQLITE_OK ){
+        nPlayback++;
+      }else{
         if( rc==SQLITE_DONE ){
           pPager->journalOff = szJ;
           break;
@@ -40056,10 +49127,11 @@ end_playback:
   ** SQLITE_FCNTL_DB_UNCHANGED file-control method to disable the
   ** assertion that the transaction counter was modified.
   */
-  assert(
-    pPager->fd->pMethods==0 ||
-    sqlite3OsFileControl(pPager->fd,SQLITE_FCNTL_DB_UNCHANGED,0)>=SQLITE_OK
-  );
+#ifdef SQLITE_DEBUG
+  if( pPager->fd->pMethods ){
+    sqlite3OsFileControlHint(pPager->fd,SQLITE_FCNTL_DB_UNCHANGED,0);
+  }
+#endif
 
   /* If this playback is happening automatically as a result of an IO or 
   ** malloc error that occurred after the change-counter was updated but 
@@ -40080,10 +49152,10 @@ end_playback:
   if( rc==SQLITE_OK
    && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)
   ){
-    rc = sqlite3PagerSync(pPager);
+    rc = sqlite3PagerSync(pPager, 0);
   }
   if( rc==SQLITE_OK ){
-    rc = pager_end_transaction(pPager, zMaster[0]!='\0');
+    rc = pager_end_transaction(pPager, zMaster[0]!='\0', 0);
     testcase( rc!=SQLITE_OK );
   }
   if( rc==SQLITE_OK && zMaster[0] && res ){
@@ -40093,6 +49165,10 @@ end_playback:
     rc = pager_delmaster(pPager, zMaster);
     testcase( rc!=SQLITE_OK );
   }
+  if( isHot && nPlayback ){
+    sqlite3_log(SQLITE_NOTICE_RECOVER_ROLLBACK, "recovered %d pages from %s",
+                nPlayback, pPager->zJournal);
+  }
 
   /* The Pager.sectorSize variable may have been updated while rolling
   ** back a journal created by a process with a different sector size
@@ -40114,27 +49190,22 @@ end_playback:
 ** If an IO error occurs, then the IO error is returned to the caller.
 ** Otherwise, SQLITE_OK is returned.
 */
-static int readDbPage(PgHdr *pPg){
+static int readDbPage(PgHdr *pPg, u32 iFrame){
   Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
   Pgno pgno = pPg->pgno;       /* Page number to read */
   int rc = SQLITE_OK;          /* Return code */
-  int isInWal = 0;             /* True if page is in log file */
   int pgsz = pPager->pageSize; /* Number of bytes to read */
 
   assert( pPager->eState>=PAGER_READER && !MEMDB );
   assert( isOpen(pPager->fd) );
 
-  if( NEVER(!isOpen(pPager->fd)) ){
-    assert( pPager->tempFile );
-    memset(pPg->pData, 0, pPager->pageSize);
-    return SQLITE_OK;
-  }
-
-  if( pagerUseWal(pPager) ){
+#ifndef SQLITE_OMIT_WAL
+  if( iFrame ){
     /* Try to pull the page from the write-ahead log. */
-    rc = sqlite3WalRead(pPager->pWal, pgno, &isInWal, pgsz, pPg->pData);
-  }
-  if( rc==SQLITE_OK && !isInWal ){
+    rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
+  }else
+#endif
+  {
     i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
     rc = sqlite3OsRead(pPager->fd, pPg->pData, pgsz, iOffset);
     if( rc==SQLITE_IOERR_SHORT_READ ){
@@ -40153,7 +49224,7 @@ static int readDbPage(PgHdr *pPg){
       **
       ** For an encrypted database, the situation is more complex:  bytes
       ** 24..39 of the database are white noise.  But the probability of
-      ** white noising equaling 16 bytes of 0xff is vanishingly small so
+      ** white noise equaling 16 bytes of 0xff is vanishingly small so
       ** we should still be ok.
       */
       memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));
@@ -40162,7 +49233,7 @@ static int readDbPage(PgHdr *pPg){
       memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
     }
   }
-  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM);
+  CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM_BKPT);
 
   PAGER_INCR(sqlite3_pager_readdb_count);
   PAGER_INCR(pPager->nRead);
@@ -40213,16 +49284,21 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
   Pager *pPager = (Pager *)pCtx;
   PgHdr *pPg;
 
+  assert( pagerUseWal(pPager) );
   pPg = sqlite3PagerLookup(pPager, iPg);
   if( pPg ){
     if( sqlite3PcachePageRefcount(pPg)==1 ){
       sqlite3PcacheDrop(pPg);
     }else{
-      rc = readDbPage(pPg);
+      u32 iFrame = 0;
+      rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
+      if( rc==SQLITE_OK ){
+        rc = readDbPage(pPg, iFrame);
+      }
       if( rc==SQLITE_OK ){
         pPager->xReiniter(pPg);
       }
-      sqlite3PagerUnref(pPg);
+      sqlite3PagerUnrefNotNull(pPg);
     }
   }
 
@@ -40278,13 +49354,11 @@ static int pagerWalFrames(
   Pager *pPager,                  /* Pager object */
   PgHdr *pList,                   /* List of frames to log */
   Pgno nTruncate,                 /* Database size after this commit */
-  int isCommit,                   /* True if this is a commit */
-  int syncFlags                   /* Flags to pass to OsSync() (or 0) */
+  int isCommit                    /* True if this is a commit */
 ){
   int rc;                         /* Return code */
-#if defined(SQLITE_DEBUG) || defined(SQLITE_CHECK_PAGES)
+  int nList;                      /* Number of pages in pList */
   PgHdr *p;                       /* For looping over pages */
-#endif
 
   assert( pPager->pWal );
   assert( pList );
@@ -40295,25 +49369,31 @@ static int pagerWalFrames(
   }
 #endif
 
+  assert( pList->pDirty==0 || isCommit );
   if( isCommit ){
     /* If a WAL transaction is being committed, there is no point in writing
     ** any pages with page numbers greater than nTruncate into the WAL file.
     ** They will never be read by any client. So remove them from the pDirty
     ** list here. */
-    PgHdr *p;
     PgHdr **ppNext = &pList;
-    for(p=pList; (*ppNext = p); p=p->pDirty){
-      if( p->pgno<=nTruncate ) ppNext = &p->pDirty;
+    nList = 0;
+    for(p=pList; (*ppNext = p)!=0; p=p->pDirty){
+      if( p->pgno<=nTruncate ){
+        ppNext = &p->pDirty;
+        nList++;
+      }
     }
     assert( pList );
+  }else{
+    nList = 1;
   }
+  pPager->aStat[PAGER_STAT_WRITE] += nList;
 
   if( pList->pgno==1 ) pager_write_changecounter(pList);
   rc = sqlite3WalFrames(pPager->pWal, 
-      pPager->pageSize, pList, nTruncate, isCommit, syncFlags
+      pPager->pageSize, pList, nTruncate, isCommit, pPager->walSyncFlags
   );
   if( rc==SQLITE_OK && pPager->pBackup ){
-    PgHdr *p;
     for(p=pList; p; p=p->pDirty){
       sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
     }
@@ -40354,6 +49434,7 @@ static int pagerBeginReadTransaction(Pager *pPager){
   rc = sqlite3WalBeginReadTransaction(pPager->pWal, &changed);
   if( rc!=SQLITE_OK || changed ){
     pager_reset(pPager);
+    if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
   }
 
   return rc;
@@ -40379,28 +49460,23 @@ static int pagerPagecount(Pager *pPager, Pgno *pnPage){
   ** contains no valid committed transactions.
   */
   assert( pPager->eState==PAGER_OPEN );
-  assert( pPager->eLock>=SHARED_LOCK || pPager->noReadlock );
+  assert( pPager->eLock>=SHARED_LOCK );
+  assert( isOpen(pPager->fd) );
+  assert( pPager->tempFile==0 );
   nPage = sqlite3WalDbsize(pPager->pWal);
 
-  /* If the database size was not available from the WAL sub-system,
-  ** determine it based on the size of the database file. If the size
-  ** of the database file is not an integer multiple of the page-size,
-  ** round down to the nearest page. Except, any file larger than 0
-  ** bytes in size is considered to contain at least one page.
+  /* If the number of pages in the database is not available from the
+  ** WAL sub-system, determine the page counte based on the size of
+  ** the database file.  If the size of the database file is not an
+  ** integer multiple of the page-size, round up the result.
   */
-  if( nPage==0 ){
+  if( nPage==0 && ALWAYS(isOpen(pPager->fd)) ){
     i64 n = 0;                    /* Size of db file in bytes */
-    assert( isOpen(pPager->fd) || pPager->tempFile );
-    if( isOpen(pPager->fd) ){
-      int rc = sqlite3OsFileSize(pPager->fd, &n);
-      if( rc!=SQLITE_OK ){
-        return rc;
-      }
-    }
-    nPage = (Pgno)(n / pPager->pageSize);
-    if( nPage==0 && n>0 ){
-      nPage = 1;
+    int rc = sqlite3OsFileSize(pPager->fd, &n);
+    if( rc!=SQLITE_OK ){
+      return rc;
     }
+    nPage = (Pgno)((n+pPager->pageSize-1) / pPager->pageSize);
   }
 
   /* If the current number of pages in the file is greater than the
@@ -40437,7 +49513,7 @@ static int pagerPagecount(Pager *pPager, Pgno *pnPage){
 static int pagerOpenWalIfPresent(Pager *pPager){
   int rc = SQLITE_OK;
   assert( pPager->eState==PAGER_OPEN );
-  assert( pPager->eLock>=SHARED_LOCK || pPager->noReadlock );
+  assert( pPager->eLock>=SHARED_LOCK );
 
   if( !pPager->tempFile ){
     int isWal;                    /* True if WAL file exists */
@@ -40447,6 +49523,7 @@ static int pagerOpenWalIfPresent(Pager *pPager){
     if( rc ) return rc;
     if( nPage==0 ){
       rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0);
+      if( rc==SQLITE_IOERR_DELETE_NOENT ) rc = SQLITE_OK;
       isWal = 0;
     }else{
       rc = sqlite3OsAccess(
@@ -40515,7 +49592,7 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
   if( pSavepoint ){
     pDone = sqlite3BitvecCreate(pSavepoint->nOrig);
     if( !pDone ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   }
 
@@ -40590,13 +49667,13 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
   */
   if( pSavepoint ){
     u32 ii;            /* Loop counter */
-    i64 offset = pSavepoint->iSubRec*(4+pPager->pageSize);
+    i64 offset = (i64)pSavepoint->iSubRec*(4+pPager->pageSize);
 
     if( pagerUseWal(pPager) ){
       rc = sqlite3WalSavepointUndo(pPager->pWal, pSavepoint->aWalData);
     }
     for(ii=pSavepoint->iSubRec; rc==SQLITE_OK && ii<pPager->nSubRec; ii++){
-      assert( offset==ii*(4+pPager->pageSize) );
+      assert( offset==(i64)ii*(4+pPager->pageSize) );
       rc = pager_playback_one_page(pPager, &offset, pDone, 0, 1);
     }
     assert( rc!=SQLITE_DONE );
@@ -40611,16 +49688,58 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
 }
 
 /*
-** Change the maximum number of in-memory pages that are allowed.
+** Change the maximum number of in-memory pages that are allowed
+** before attempting to recycle clean and unused pages.
 */
 SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
   sqlite3PcacheSetCachesize(pPager->pPCache, mxPage);
 }
 
 /*
-** Adjust the robustness of the database to damage due to OS crashes
-** or power failures by changing the number of syncs()s when writing
-** the rollback journal.  There are three levels:
+** Change the maximum number of in-memory pages that are allowed
+** before attempting to spill pages to journal.
+*/
+SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager *pPager, int mxPage){
+  return sqlite3PcacheSetSpillsize(pPager->pPCache, mxPage);
+}
+
+/*
+** Invoke SQLITE_FCNTL_MMAP_SIZE based on the current value of szMmap.
+*/
+static void pagerFixMaplimit(Pager *pPager){
+#if SQLITE_MAX_MMAP_SIZE>0
+  sqlite3_file *fd = pPager->fd;
+  if( isOpen(fd) && fd->pMethods->iVersion>=3 ){
+    sqlite3_int64 sz;
+    sz = pPager->szMmap;
+    pPager->bUseFetch = (sz>0);
+    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);
+  }
+#endif
+}
+
+/*
+** Change the maximum size of any memory mapping made of the database file.
+*/
+SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *pPager, sqlite3_int64 szMmap){
+  pPager->szMmap = szMmap;
+  pagerFixMaplimit(pPager);
+}
+
+/*
+** Free as much memory as possible from the pager.
+*/
+SQLITE_PRIVATE void sqlite3PagerShrink(Pager *pPager){
+  sqlite3PcacheShrink(pPager->pPCache);
+}
+
+/*
+** Adjust settings of the pager to those specified in the pgFlags parameter.
+**
+** The "level" in pgFlags & PAGER_SYNCHRONOUS_MASK sets the robustness
+** of the database to damage due to OS crashes or power failures by
+** changing the number of syncs()s when writing the journals.
+** There are four levels:
 **
 **    OFF       sqlite3OsSync() is never called.  This is the default
 **              for temporary and transient files.
@@ -40640,6 +49759,10 @@ SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 **              assurance that the journal will not be corrupted to the
 **              point of causing damage to the database during rollback.
 **
+**    EXTRA     This is like FULL except that is also syncs the directory
+**              that contains the rollback journal after the rollback
+**              journal is unlinked.
+**
 ** The above is for a rollback-journal mode.  For WAL mode, OFF continues
 ** to mean that no syncs ever occur.  NORMAL means that the WAL is synced
 ** prior to the start of checkpoint and that the database file is synced
@@ -40647,7 +49770,8 @@ SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 ** was written back into the database.  But no sync operations occur for
 ** an ordinary commit in NORMAL mode with WAL.  FULL means that the WAL
 ** file is synced following each commit operation, in addition to the
-** syncs associated with NORMAL.
+** syncs associated with NORMAL.  There is no difference between FULL
+** and EXTRA for WAL mode.
 **
 ** Do not confuse synchronous=FULL with SQLITE_SYNC_FULL.  The
 ** SQLITE_SYNC_FULL macro means to use the MacOSX-style full-fsync
@@ -40661,28 +49785,42 @@ SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 ** and FULL=3.
 */
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
-SQLITE_PRIVATE void sqlite3PagerSetSafetyLevel(
+SQLITE_PRIVATE void sqlite3PagerSetFlags(
   Pager *pPager,        /* The pager to set safety level for */
-  int level,            /* PRAGMA synchronous.  1=OFF, 2=NORMAL, 3=FULL */  
-  int bFullFsync,       /* PRAGMA fullfsync */
-  int bCkptFullFsync    /* PRAGMA checkpoint_fullfsync */
+  unsigned pgFlags      /* Various flags */
 ){
-  assert( level>=1 && level<=3 );
-  pPager->noSync =  (level==1 || pPager->tempFile) ?1:0;
-  pPager->fullSync = (level==3 && !pPager->tempFile) ?1:0;
+  unsigned level = pgFlags & PAGER_SYNCHRONOUS_MASK;
+  if( pPager->tempFile ){
+    pPager->noSync = 1;
+    pPager->fullSync = 0;
+    pPager->extraSync = 0;
+  }else{
+    pPager->noSync =  level==PAGER_SYNCHRONOUS_OFF ?1:0;
+    pPager->fullSync = level>=PAGER_SYNCHRONOUS_FULL ?1:0;
+    pPager->extraSync = level==PAGER_SYNCHRONOUS_EXTRA ?1:0;
+  }
   if( pPager->noSync ){
     pPager->syncFlags = 0;
     pPager->ckptSyncFlags = 0;
-  }else if( bFullFsync ){
+  }else if( pgFlags & PAGER_FULLFSYNC ){
     pPager->syncFlags = SQLITE_SYNC_FULL;
     pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
-  }else if( bCkptFullFsync ){
+  }else if( pgFlags & PAGER_CKPT_FULLFSYNC ){
     pPager->syncFlags = SQLITE_SYNC_NORMAL;
     pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
   }else{
     pPager->syncFlags = SQLITE_SYNC_NORMAL;
     pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
   }
+  pPager->walSyncFlags = pPager->syncFlags;
+  if( pPager->fullSync ){
+    pPager->walSyncFlags |= WAL_SYNC_TRANSACTIONS;
+  }
+  if( pgFlags & PAGER_CACHESPILL ){
+    pPager->doNotSpill &= ~SPILLFLAG_OFF;
+  }else{
+    pPager->doNotSpill |= SPILLFLAG_OFF;
+  }
 }
 #endif
 
@@ -40753,9 +49891,16 @@ SQLITE_PRIVATE void sqlite3PagerSetBusyhandler(
   Pager *pPager,                       /* Pager object */
   int (*xBusyHandler)(void *),         /* Pointer to busy-handler function */
   void *pBusyHandlerArg                /* Argument to pass to xBusyHandler */
-){  
+){
   pPager->xBusyHandler = xBusyHandler;
   pPager->pBusyHandlerArg = pBusyHandlerArg;
+
+  if( isOpen(pPager->fd) ){
+    void **ap = (void **)&pPager->xBusyHandler;
+    assert( ((int(*)(void *))(ap[0]))==xBusyHandler );
+    assert( ap[1]==pBusyHandlerArg );
+    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_BUSYHANDLER, (void *)ap);
+  }
 }
 
 /*
@@ -40815,16 +49960,20 @@ SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nR
     }
     if( rc==SQLITE_OK ){
       pNew = (char *)sqlite3PageMalloc(pageSize);
-      if( !pNew ) rc = SQLITE_NOMEM;
+      if( !pNew ) rc = SQLITE_NOMEM_BKPT;
     }
 
     if( rc==SQLITE_OK ){
       pager_reset(pPager);
-      pPager->dbSize = (Pgno)(nByte/pageSize);
-      pPager->pageSize = pageSize;
+      rc = sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
+    }
+    if( rc==SQLITE_OK ){
       sqlite3PageFree(pPager->pTmpSpace);
       pPager->pTmpSpace = pNew;
-      sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
+      pPager->dbSize = (Pgno)((nByte+pageSize-1)/pageSize);
+      pPager->pageSize = pageSize;
+    }else{
+      sqlite3PageFree(pNew);
     }
   }
 
@@ -40834,6 +49983,7 @@ SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nR
     assert( nReserve>=0 && nReserve<1000 );
     pPager->nReserve = (i16)nReserve;
     pagerReportSize(pPager);
+    pagerFixMaplimit(pPager);
   }
   return rc;
 }
@@ -40957,7 +50107,7 @@ static int pager_wait_on_lock(Pager *pPager, int locktype){
   int rc;                              /* Return code */
 
   /* Check that this is either a no-op (because the requested lock is 
-  ** already held, or one of the transistions that the busy-handler
+  ** already held), or one of the transitions that the busy-handler
   ** may be invoked during, according to the comment above
   ** sqlite3PagerSetBusyhandler().
   */
@@ -40987,7 +50137,7 @@ static int pager_wait_on_lock(Pager *pPager, int locktype){
 ** dirty page were to be discarded from the cache via the pagerStress()
 ** routine, pagerStress() would not write the current page content to
 ** the database file. If a savepoint transaction were rolled back after
-** this happened, the correct behaviour would be to restore the current
+** this happened, the correct behavior would be to restore the current
 ** content of the page. However, since this content is not present in either
 ** the database file or the portion of the rollback journal and 
 ** sub-journal rolled back the content could not be restored and the
@@ -41011,12 +50161,26 @@ static void assertTruncateConstraint(Pager *pPager){
 ** function does not actually modify the database file on disk. It 
 ** just sets the internal state of the pager object so that the 
 ** truncation will be done when the current transaction is committed.
+**
+** This function is only called right before committing a transaction.
+** Once this function has been called, the transaction must either be
+** rolled back or committed. It is not safe to call this function and
+** then continue writing to the database.
 */
 SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager *pPager, Pgno nPage){
   assert( pPager->dbSize>=nPage );
   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );
   pPager->dbSize = nPage;
-  assertTruncateConstraint(pPager);
+
+  /* At one point the code here called assertTruncateConstraint() to
+  ** ensure that all pages being truncated away by this operation are,
+  ** if one or more savepoints are open, present in the savepoint 
+  ** journal so that they can be restored if the savepoint is rolled
+  ** back. This is no longer necessary as this function is now only
+  ** called right before committing a transaction. So although the 
+  ** Pager object may still have open savepoints (Pager.nSavepoint!=0), 
+  ** they cannot be rolled back. So the assertTruncateConstraint() call
+  ** is no longer correct. */
 }
 
 
@@ -41046,6 +50210,81 @@ static int pagerSyncHotJournal(Pager *pPager){
 }
 
 /*
+** Obtain a reference to a memory mapped page object for page number pgno. 
+** The new object will use the pointer pData, obtained from xFetch().
+** If successful, set *ppPage to point to the new page reference
+** and return SQLITE_OK. Otherwise, return an SQLite error code and set
+** *ppPage to zero.
+**
+** Page references obtained by calling this function should be released
+** by calling pagerReleaseMapPage().
+*/
+static int pagerAcquireMapPage(
+  Pager *pPager,                  /* Pager object */
+  Pgno pgno,                      /* Page number */
+  void *pData,                    /* xFetch()'d data for this page */
+  PgHdr **ppPage                  /* OUT: Acquired page object */
+){
+  PgHdr *p;                       /* Memory mapped page to return */
+  
+  if( pPager->pMmapFreelist ){
+    *ppPage = p = pPager->pMmapFreelist;
+    pPager->pMmapFreelist = p->pDirty;
+    p->pDirty = 0;
+    memset(p->pExtra, 0, pPager->nExtra);
+  }else{
+    *ppPage = p = (PgHdr *)sqlite3MallocZero(sizeof(PgHdr) + pPager->nExtra);
+    if( p==0 ){
+      sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1) * pPager->pageSize, pData);
+      return SQLITE_NOMEM_BKPT;
+    }
+    p->pExtra = (void *)&p[1];
+    p->flags = PGHDR_MMAP;
+    p->nRef = 1;
+    p->pPager = pPager;
+  }
+
+  assert( p->pExtra==(void *)&p[1] );
+  assert( p->pPage==0 );
+  assert( p->flags==PGHDR_MMAP );
+  assert( p->pPager==pPager );
+  assert( p->nRef==1 );
+
+  p->pgno = pgno;
+  p->pData = pData;
+  pPager->nMmapOut++;
+
+  return SQLITE_OK;
+}
+
+/*
+** Release a reference to page pPg. pPg must have been returned by an 
+** earlier call to pagerAcquireMapPage().
+*/
+static void pagerReleaseMapPage(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  pPager->nMmapOut--;
+  pPg->pDirty = pPager->pMmapFreelist;
+  pPager->pMmapFreelist = pPg;
+
+  assert( pPager->fd->pMethods->iVersion>=3 );
+  sqlite3OsUnfetch(pPager->fd, (i64)(pPg->pgno-1)*pPager->pageSize, pPg->pData);
+}
+
+/*
+** Free all PgHdr objects stored in the Pager.pMmapFreelist list.
+*/
+static void pagerFreeMapHdrs(Pager *pPager){
+  PgHdr *p;
+  PgHdr *pNext;
+  for(p=pPager->pMmapFreelist; p; p=pNext){
+    pNext = p->pDirty;
+    sqlite3_free(p);
+  }
+}
+
+
+/*
 ** Shutdown the page cache.  Free all memory and close all files.
 **
 ** If a transaction was in progress when this routine is called, that
@@ -41065,6 +50304,7 @@ SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager){
   assert( assert_pager_state(pPager) );
   disable_simulated_io_errors();
   sqlite3BeginBenignMalloc();
+  pagerFreeMapHdrs(pPager);
   /* pPager->errCode = 0; */
   pPager->exclusiveMode = 0;
 #ifndef SQLITE_OMIT_WAL
@@ -41134,7 +50374,7 @@ SQLITE_PRIVATE void sqlite3PagerRef(DbPage *pPg){
 **
 ** If the Pager.noSync flag is set, then this function is a no-op.
 ** Otherwise, the actions required depend on the journal-mode and the 
-** device characteristics of the the file-system, as follows:
+** device characteristics of the file-system, as follows:
 **
 **   * If the journal file is an in-memory journal file, no action need
 **     be taken.
@@ -41310,8 +50550,9 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
 
   /* This function is only called for rollback pagers in WRITER_DBMOD state. */
   assert( !pagerUseWal(pPager) );
-  assert( pPager->eState==PAGER_WRITER_DBMOD );
+  assert( pPager->tempFile || pPager->eState==PAGER_WRITER_DBMOD );
   assert( pPager->eLock==EXCLUSIVE_LOCK );
+  assert( isOpen(pPager->fd) || pList->pDirty==0 );
 
   /* If the file is a temp-file has not yet been opened, open it now. It
   ** is not possible for rc to be other than SQLITE_OK if this branch
@@ -41326,9 +50567,12 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
   ** file size will be.
   */
   assert( rc!=SQLITE_OK || isOpen(pPager->fd) );
-  if( rc==SQLITE_OK && pPager->dbSize>pPager->dbHintSize ){
+  if( rc==SQLITE_OK 
+   && pPager->dbHintSize<pPager->dbSize
+   && (pList->pDirty || pList->pgno>pPager->dbHintSize)
+  ){
     sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
-    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
+    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
     pPager->dbHintSize = pPager->dbSize;
   }
 
@@ -41351,7 +50595,7 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
       if( pList->pgno==1 ) pager_write_changecounter(pList);
 
       /* Encode the database */
-      CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM, pData);
+      CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM_BKPT, pData);
 
       /* Write out the page data. */
       rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);
@@ -41366,6 +50610,7 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
       if( pgno>pPager->dbFileSize ){
         pPager->dbFileSize = pgno;
       }
+      pPager->aStat[PAGER_STAT_WRITE]++;
 
       /* Update any backup objects copying the contents of this pager. */
       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)pList->pData);
@@ -41374,7 +50619,6 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
                    PAGERID(pPager), pgno, pager_pagehash(pList)));
       IOTRACE(("PGOUT %p %d\n", pPager, pgno));
       PAGER_INCR(sqlite3_pager_writedb_count);
-      PAGER_INCR(pPager->nWrite);
     }else{
       PAGERTRACE(("NOSTORE %d page %d\n", PAGERID(pPager), pgno));
     }
@@ -41396,19 +50640,20 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
 static int openSubJournal(Pager *pPager){
   int rc = SQLITE_OK;
   if( !isOpen(pPager->sjfd) ){
+    const int flags =  SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_READWRITE 
+      | SQLITE_OPEN_CREATE | SQLITE_OPEN_EXCLUSIVE 
+      | SQLITE_OPEN_DELETEONCLOSE;
+    int nStmtSpill = sqlite3Config.nStmtSpill;
     if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
-      sqlite3MemJournalOpen(pPager->sjfd);
-    }else{
-      rc = pagerOpentemp(pPager, pPager->sjfd, SQLITE_OPEN_SUBJOURNAL);
+      nStmtSpill = -1;
     }
+    rc = sqlite3JournalOpen(pPager->pVfs, 0, pPager->sjfd, flags, nStmtSpill);
   }
   return rc;
 }
 
 /*
 ** Append a record of the current state of page pPg to the sub-journal. 
-** It is the callers responsibility to use subjRequiresPage() to check 
-** that it is really required before calling this function.
 **
 ** If successful, set the bit corresponding to pPg->pgno in the bitvecs
 ** for all open savepoints before returning.
@@ -41428,7 +50673,7 @@ static int subjournalPage(PgHdr *pPg){
     assert( isOpen(pPager->jfd) || pagerUseWal(pPager) );
     assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 );
     assert( pagerUseWal(pPager) 
-         || pageInJournal(pPg) 
+         || pageInJournal(pPager, pPg) 
          || pPg->pgno>pPager->dbOrigSize 
     );
     rc = openSubJournal(pPager);
@@ -41437,10 +50682,10 @@ static int subjournalPage(PgHdr *pPg){
     ** write the journal record into the file.  */
     if( rc==SQLITE_OK ){
       void *pData = pPg->pData;
-      i64 offset = pPager->nSubRec*(4+pPager->pageSize);
+      i64 offset = (i64)pPager->nSubRec*(4+pPager->pageSize);
       char *pData2;
   
-      CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
+      CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
       PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
       rc = write32bits(pPager->sjfd, offset, pPg->pgno);
       if( rc==SQLITE_OK ){
@@ -41455,6 +50700,13 @@ static int subjournalPage(PgHdr *pPg){
   }
   return rc;
 }
+static int subjournalPageIfRequired(PgHdr *pPg){
+  if( subjRequiresPage(pPg) ){
+    return subjournalPage(pPg);
+  }else{
+    return SQLITE_OK;
+  }
+}
 
 /*
 ** This function is called by the pcache layer when it has reached some
@@ -41482,35 +50734,39 @@ static int pagerStress(void *p, PgHdr *pPg){
   assert( pPg->pPager==pPager );
   assert( pPg->flags&PGHDR_DIRTY );
 
-  /* The doNotSyncSpill flag is set during times when doing a sync of
+  /* The doNotSpill NOSYNC bit is set during times when doing a sync of
   ** journal (and adding a new header) is not allowed.  This occurs
   ** during calls to sqlite3PagerWrite() while trying to journal multiple
   ** pages belonging to the same sector.
   **
-  ** The doNotSpill flag inhibits all cache spilling regardless of whether
-  ** or not a sync is required.  This is set during a rollback.
+  ** The doNotSpill ROLLBACK and OFF bits inhibits all cache spilling
+  ** regardless of whether or not a sync is required.  This is set during
+  ** a rollback or by user request, respectively.
   **
   ** Spilling is also prohibited when in an error state since that could
-  ** lead to database corruption.   In the current implementaton it 
-  ** is impossible for sqlite3PcacheFetch() to be called with createFlag==1
+  ** lead to database corruption.   In the current implementation it 
+  ** is impossible for sqlite3PcacheFetch() to be called with createFlag==3
   ** while in the error state, hence it is impossible for this routine to
   ** be called in the error state.  Nevertheless, we include a NEVER()
   ** test for the error state as a safeguard against future changes.
   */
   if( NEVER(pPager->errCode) ) return SQLITE_OK;
-  if( pPager->doNotSpill ) return SQLITE_OK;
-  if( pPager->doNotSyncSpill && (pPg->flags & PGHDR_NEED_SYNC)!=0 ){
+  testcase( pPager->doNotSpill & SPILLFLAG_ROLLBACK );
+  testcase( pPager->doNotSpill & SPILLFLAG_OFF );
+  testcase( pPager->doNotSpill & SPILLFLAG_NOSYNC );
+  if( pPager->doNotSpill
+   && ((pPager->doNotSpill & (SPILLFLAG_ROLLBACK|SPILLFLAG_OFF))!=0
+      || (pPg->flags & PGHDR_NEED_SYNC)!=0)
+  ){
     return SQLITE_OK;
   }
 
   pPg->pDirty = 0;
   if( pagerUseWal(pPager) ){
     /* Write a single frame for this page to the log. */
-    if( subjRequiresPage(pPg) ){ 
-      rc = subjournalPage(pPg); 
-    }
+    rc = subjournalPageIfRequired(pPg); 
     if( rc==SQLITE_OK ){
-      rc = pagerWalFrames(pPager, pPg, 0, 0, 0);
+      rc = pagerWalFrames(pPager, pPg, 0, 0);
     }
   }else{
   
@@ -41521,39 +50777,6 @@ static int pagerStress(void *p, PgHdr *pPg){
       rc = syncJournal(pPager, 1);
     }
   
-    /* If the page number of this page is larger than the current size of
-    ** the database image, it may need to be written to the sub-journal.
-    ** This is because the call to pager_write_pagelist() below will not
-    ** actually write data to the file in this case.
-    **
-    ** Consider the following sequence of events:
-    **
-    **   BEGIN;
-    **     <journal page X>
-    **     <modify page X>
-    **     SAVEPOINT sp;
-    **       <shrink database file to Y pages>
-    **       pagerStress(page X)
-    **     ROLLBACK TO sp;
-    **
-    ** If (X>Y), then when pagerStress is called page X will not be written
-    ** out to the database file, but will be dropped from the cache. Then,
-    ** following the "ROLLBACK TO sp" statement, reading page X will read
-    ** data from the database file. This will be the copy of page X as it
-    ** was when the transaction started, not as it was when "SAVEPOINT sp"
-    ** was executed.
-    **
-    ** The solution is to write the current data for page X into the 
-    ** sub-journal file now (if it is not already there), so that it will
-    ** be restored to its current value when the "ROLLBACK TO sp" is 
-    ** executed.
-    */
-    if( NEVER(
-        rc==SQLITE_OK && pPg->pgno>pPager->dbSize && subjRequiresPage(pPg)
-    ) ){
-      rc = subjournalPage(pPg);
-    }
-  
     /* Write the contents of the page out to the database file. */
     if( rc==SQLITE_OK ){
       assert( (pPg->flags&PGHDR_NEED_SYNC)==0 );
@@ -41570,6 +50793,25 @@ static int pagerStress(void *p, PgHdr *pPg){
   return pager_error(pPager, rc); 
 }
 
+/*
+** Flush all unreferenced dirty pages to disk.
+*/
+SQLITE_PRIVATE int sqlite3PagerFlush(Pager *pPager){
+  int rc = pPager->errCode;
+  if( !MEMDB ){
+    PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
+    assert( assert_pager_state(pPager) );
+    while( rc==SQLITE_OK && pList ){
+      PgHdr *pNext = pList->pDirty;
+      if( pList->nRef==0 ){
+        rc = pagerStress((void*)pPager, pList);
+      }
+      pList = pNext;
+    }
+  }
+
+  return rc;
+}
 
 /*
 ** Allocate and initialize a new Pager object and put a pointer to it
@@ -41589,7 +50831,7 @@ static int pagerStress(void *p, PgHdr *pPg){
 **
 ** The flags argument is used to specify properties that affect the
 ** operation of the pager. It should be passed some bitwise combination
-** of the PAGER_OMIT_JOURNAL and PAGER_NO_READLOCK flags.
+** of the PAGER_* flags.
 **
 ** The vfsFlags parameter is a bitmask to pass to the flags parameter
 ** of the xOpen() method of the supplied VFS when opening files. 
@@ -41620,25 +50862,14 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   char *zPathname = 0;     /* Full path to database file */
   int nPathname = 0;       /* Number of bytes in zPathname */
   int useJournal = (flags & PAGER_OMIT_JOURNAL)==0; /* False to omit journal */
-  int noReadlock = (flags & PAGER_NO_READLOCK)!=0;  /* True to omit read-lock */
   int pcacheSize = sqlite3PcacheSize();       /* Bytes to allocate for PCache */
   u32 szPageDflt = SQLITE_DEFAULT_PAGE_SIZE;  /* Default page size */
   const char *zUri = 0;    /* URI args to copy */
   int nUri = 0;            /* Number of bytes of URI args at *zUri */
 
   /* Figure out how much space is required for each journal file-handle
-  ** (there are two of them, the main journal and the sub-journal). This
-  ** is the maximum space required for an in-memory journal file handle 
-  ** and a regular journal file-handle. Note that a "regular journal-handle"
-  ** may be a wrapper capable of caching the first portion of the journal
-  ** file in memory to implement the atomic-write optimization (see 
-  ** source file journal.c).
-  */
-  if( sqlite3JournalSize(pVfs)>sqlite3MemJournalSize() ){
-    journalFileSize = ROUND8(sqlite3JournalSize(pVfs));
-  }else{
-    journalFileSize = ROUND8(sqlite3MemJournalSize());
-  }
+  ** (there are two of them, the main journal and the sub-journal).  */
+  journalFileSize = ROUND8(sqlite3JournalSize(pVfs));
 
   /* Set the output variable to NULL in case an error occurs. */
   *ppPager = 0;
@@ -41646,7 +50877,12 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
 #ifndef SQLITE_OMIT_MEMORYDB
   if( flags & PAGER_MEMORY ){
     memDb = 1;
-    zFilename = 0;
+    if( zFilename && zFilename[0] ){
+      zPathname = sqlite3DbStrDup(0, zFilename);
+      if( zPathname==0  ) return SQLITE_NOMEM_BKPT;
+      nPathname = sqlite3Strlen30(zPathname);
+      zFilename = 0;
+    }
   }
 #endif
 
@@ -41657,9 +50893,9 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   if( zFilename && zFilename[0] ){
     const char *z;
     nPathname = pVfs->mxPathname+1;
-    zPathname = sqlite3Malloc(nPathname*2);
+    zPathname = sqlite3DbMallocRaw(0, nPathname*2);
     if( zPathname==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     zPathname[0] = 0; /* Make sure initialized even if FullPathname() fails */
     rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);
@@ -41669,7 +50905,8 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
       z += sqlite3Strlen30(z)+1;
       z += sqlite3Strlen30(z)+1;
     }
-    nUri = &z[1] - zUri;
+    nUri = (int)(&z[1] - zUri);
+    assert( nUri>=0 );
     if( rc==SQLITE_OK && nPathname+8>pVfs->mxPathname ){
       /* This branch is taken when the journal path required by
       ** the database being opened will be more than pVfs->mxPathname
@@ -41680,7 +50917,7 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
       rc = SQLITE_CANTOPEN_BKPT;
     }
     if( rc!=SQLITE_OK ){
-      sqlite3_free(zPathname);
+      sqlite3DbFree(0, zPathname);
       return rc;
     }
   }
@@ -41703,15 +50940,15 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     ROUND8(pVfs->szOsFile) +       /* The main db file */
     journalFileSize * 2 +          /* The two journal files */ 
     nPathname + 1 + nUri +         /* zFilename */
-    nPathname + 8 + 1              /* zJournal */
+    nPathname + 8 + 2              /* zJournal */
 #ifndef SQLITE_OMIT_WAL
-    + nPathname + 4 + 1              /* zWal */
+    + nPathname + 4 + 2            /* zWal */
 #endif
   );
   assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) );
   if( !pPtr ){
-    sqlite3_free(zPathname);
-    return SQLITE_NOMEM;
+    sqlite3DbFree(0, zPathname);
+    return SQLITE_NOMEM_BKPT;
   }
   pPager =              (Pager*)(pPtr);
   pPager->pPCache =    (PCache*)(pPtr += ROUND8(sizeof(*pPager)));
@@ -41726,17 +50963,17 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     assert( nPathname>0 );
     pPager->zJournal =   (char*)(pPtr += nPathname + 1 + nUri);
     memcpy(pPager->zFilename, zPathname, nPathname);
-    memcpy(&pPager->zFilename[nPathname+1], zUri, nUri);
+    if( nUri ) memcpy(&pPager->zFilename[nPathname+1], zUri, nUri);
     memcpy(pPager->zJournal, zPathname, nPathname);
-    memcpy(&pPager->zJournal[nPathname], "-journal", 8);
+    memcpy(&pPager->zJournal[nPathname], "-journal\000", 8+2);
     sqlite3FileSuffix3(pPager->zFilename, pPager->zJournal);
 #ifndef SQLITE_OMIT_WAL
     pPager->zWal = &pPager->zJournal[nPathname+8+1];
     memcpy(pPager->zWal, zPathname, nPathname);
-    memcpy(&pPager->zWal[nPathname], "-wal", 4);
+    memcpy(&pPager->zWal[nPathname], "-wal\000", 4+1);
     sqlite3FileSuffix3(pPager->zFilename, pPager->zWal);
 #endif
-    sqlite3_free(zPathname);
+    sqlite3DbFree(0, zPathname);
   }
   pPager->pVfs = pVfs;
   pPager->vfsFlags = vfsFlags;
@@ -41757,30 +50994,38 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     **    + The value returned by sqlite3OsSectorSize()
     **    + The largest page size that can be written atomically.
     */
-    if( rc==SQLITE_OK && !readOnly ){
-      setSectorSize(pPager);
-      assert(SQLITE_DEFAULT_PAGE_SIZE<=SQLITE_MAX_DEFAULT_PAGE_SIZE);
-      if( szPageDflt<pPager->sectorSize ){
-        if( pPager->sectorSize>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
-          szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
-        }else{
-          szPageDflt = (u32)pPager->sectorSize;
+    if( rc==SQLITE_OK ){
+      int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
+      if( !readOnly ){
+        setSectorSize(pPager);
+        assert(SQLITE_DEFAULT_PAGE_SIZE<=SQLITE_MAX_DEFAULT_PAGE_SIZE);
+        if( szPageDflt<pPager->sectorSize ){
+          if( pPager->sectorSize>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
+            szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
+          }else{
+            szPageDflt = (u32)pPager->sectorSize;
+          }
         }
-      }
 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
-      {
-        int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
-        int ii;
-        assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
-        assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
-        assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);
-        for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){
-          if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ){
-            szPageDflt = ii;
+        {
+          int ii;
+          assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
+          assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
+          assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);
+          for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){
+            if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ){
+              szPageDflt = ii;
+            }
           }
         }
-      }
 #endif
+      }
+      pPager->noLock = sqlite3_uri_boolean(zFilename, "nolock", 0);
+      if( (iDc & SQLITE_IOCAP_IMMUTABLE)!=0
+       || sqlite3_uri_boolean(zFilename, "immutable", 0) ){
+          vfsFlags |= SQLITE_OPEN_READONLY;
+          goto act_like_temp_file;
+      }
     }
   }else{
     /* If a temporary file is requested, it is not opened immediately.
@@ -41790,10 +51035,14 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     ** This branch is also run for an in-memory database. An in-memory
     ** database is the same as a temp-file that is never written out to
     ** disk and uses an in-memory rollback journal.
+    **
+    ** This branch also runs for files marked as immutable.
     */ 
+act_like_temp_file:
     tempFile = 1;
-    pPager->eState = PAGER_READER;
-    pPager->eLock = EXCLUSIVE_LOCK;
+    pPager->eState = PAGER_READER;     /* Pretend we already have a lock */
+    pPager->eLock = EXCLUSIVE_LOCK;    /* Pretend we are in EXCLUSIVE mode */
+    pPager->noLock = 1;                /* Do no locking */
     readOnly = (vfsFlags&SQLITE_OPEN_READONLY);
   }
 
@@ -41806,27 +51055,27 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
     testcase( rc!=SQLITE_OK );
   }
 
-  /* If an error occurred in either of the blocks above, free the 
-  ** Pager structure and close the file.
+  /* Initialize the PCache object. */
+  if( rc==SQLITE_OK ){
+    assert( nExtra<1000 );
+    nExtra = ROUND8(nExtra);
+    rc = sqlite3PcacheOpen(szPageDflt, nExtra, !memDb,
+                       !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);
+  }
+
+  /* If an error occurred above, free the  Pager structure and close the file.
   */
   if( rc!=SQLITE_OK ){
-    assert( !pPager->pTmpSpace );
     sqlite3OsClose(pPager->fd);
+    sqlite3PageFree(pPager->pTmpSpace);
     sqlite3_free(pPager);
     return rc;
   }
 
-  /* Initialize the PCache object. */
-  assert( nExtra<1000 );
-  nExtra = ROUND8(nExtra);
-  sqlite3PcacheOpen(szPageDflt, nExtra, !memDb,
-                    !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);
-
   PAGERTRACE(("OPEN %d %s\n", FILEHANDLEID(pPager->fd), pPager->zFilename));
   IOTRACE(("OPEN %p %s\n", pPager, pPager->zFilename))
 
   pPager->useJournal = (u8)useJournal;
-  pPager->noReadlock = (noReadlock && readOnly) ?1:0;
   /* pPager->stmtOpen = 0; */
   /* pPager->stmtInUse = 0; */
   /* pPager->nRef = 0; */
@@ -41835,9 +51084,6 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   /* pPager->nPage = 0; */
   pPager->mxPgno = SQLITE_MAX_PAGE_COUNT;
   /* pPager->state = PAGER_UNLOCK; */
-#if 0
-  assert( pPager->state == (tempFile ? PAGER_EXCLUSIVE : PAGER_UNLOCK) );
-#endif
   /* pPager->errMask = 0; */
   pPager->tempFile = (u8)tempFile;
   assert( tempFile==PAGER_LOCKINGMODE_NORMAL 
@@ -41849,9 +51095,19 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   pPager->readOnly = (u8)readOnly;
   assert( useJournal || pPager->tempFile );
   pPager->noSync = pPager->tempFile;
-  pPager->fullSync = pPager->noSync ?0:1;
-  pPager->syncFlags = pPager->noSync ? 0 : SQLITE_SYNC_NORMAL;
-  pPager->ckptSyncFlags = pPager->syncFlags;
+  if( pPager->noSync ){
+    assert( pPager->fullSync==0 );
+    assert( pPager->extraSync==0 );
+    assert( pPager->syncFlags==0 );
+    assert( pPager->walSyncFlags==0 );
+    assert( pPager->ckptSyncFlags==0 );
+  }else{
+    pPager->fullSync = 1;
+    pPager->extraSync = 0;
+    pPager->syncFlags = SQLITE_SYNC_NORMAL;
+    pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
+    pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
+  }
   /* pPager->pFirst = 0; */
   /* pPager->pFirstSynced = 0; */
   /* pPager->pLast = 0; */
@@ -41868,12 +51124,37 @@ SQLITE_PRIVATE int sqlite3PagerOpen(
   /* pPager->pBusyHandlerArg = 0; */
   pPager->xReiniter = xReinit;
   /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
+  /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */
 
   *ppPager = pPager;
   return SQLITE_OK;
 }
 
 
+/* Verify that the database file has not be deleted or renamed out from
+** under the pager.  Return SQLITE_OK if the database is still were it ought
+** to be on disk.  Return non-zero (SQLITE_READONLY_DBMOVED or some other error
+** code from sqlite3OsAccess()) if the database has gone missing.
+*/
+static int databaseIsUnmoved(Pager *pPager){
+  int bHasMoved = 0;
+  int rc;
+
+  if( pPager->tempFile ) return SQLITE_OK;
+  if( pPager->dbSize==0 ) return SQLITE_OK;
+  assert( pPager->zFilename && pPager->zFilename[0] );
+  rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_HAS_MOVED, &bHasMoved);
+  if( rc==SQLITE_NOTFOUND ){
+    /* If the HAS_MOVED file-control is unimplemented, assume that the file
+    ** has not been moved.  That is the historical behavior of SQLite: prior to
+    ** version 3.8.3, it never checked */
+    rc = SQLITE_OK;
+  }else if( rc==SQLITE_OK && bHasMoved ){
+    rc = SQLITE_READONLY_DBMOVED;
+  }
+  return rc;
+}
+
 
 /*
 ** This function is called after transitioning from PAGER_UNLOCK to
@@ -41939,15 +51220,18 @@ static int hasHotJournal(Pager *pPager, int *pExists){
     if( rc==SQLITE_OK && !locked ){
       Pgno nPage;                 /* Number of pages in database file */
 
-      /* Check the size of the database file. If it consists of 0 pages,
-      ** then delete the journal file. See the header comment above for 
-      ** the reasoning here.  Delete the obsolete journal file under
-      ** a RESERVED lock to avoid race conditions and to avoid violating
-      ** [H33020].
-      */
+      assert( pPager->tempFile==0 );
       rc = pagerPagecount(pPager, &nPage);
       if( rc==SQLITE_OK ){
-        if( nPage==0 ){
+        /* If the database is zero pages in size, that means that either (1) the
+        ** journal is a remnant from a prior database with the same name where
+        ** the database file but not the journal was deleted, or (2) the initial
+        ** transaction that populates a new database is being rolled back.
+        ** In either case, the journal file can be deleted.  However, take care
+        ** not to delete the journal file if it is already open due to
+        ** journal_mode=PERSIST.
+        */
+        if( nPage==0 && !jrnlOpen ){
           sqlite3BeginBenignMalloc();
           if( pagerLockDb(pPager, RESERVED_LOCK)==SQLITE_OK ){
             sqlite3OsDelete(pVfs, pPager->zJournal, 0);
@@ -41977,7 +51261,7 @@ static int hasHotJournal(Pager *pPager, int *pExists){
             *pExists = (first!=0);
           }else if( rc==SQLITE_CANTOPEN ){
             /* If we cannot open the rollback journal file in order to see if
-            ** its has a zero header, that might be due to an I/O error, or
+            ** it has a zero header, that might be due to an I/O error, or
             ** it might be due to the race condition described above and in
             ** ticket #3883.  Either way, assume that the journal is hot.
             ** This might be a false positive.  But if it is, then the
@@ -41998,7 +51282,7 @@ static int hasHotJournal(Pager *pPager, int *pExists){
 
 /*
 ** This function is called to obtain a shared lock on the database file.
-** It is illegal to call sqlite3PagerAcquire() until after this function
+** It is illegal to call sqlite3PagerGet() until after this function
 ** has been successfully called. If a shared-lock is already held when
 ** this function is called, it is a no-op.
 **
@@ -42029,25 +51313,22 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
   /* This routine is only called from b-tree and only when there are no
   ** outstanding pages. This implies that the pager state should either
   ** be OPEN or READER. READER is only possible if the pager is or was in 
-  ** exclusive access mode.
-  */
+  ** exclusive access mode.  */
   assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
   assert( assert_pager_state(pPager) );
   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );
-  if( NEVER(MEMDB && pPager->errCode) ){ return pPager->errCode; }
+  assert( pPager->errCode==SQLITE_OK );
 
   if( !pagerUseWal(pPager) && pPager->eState==PAGER_OPEN ){
     int bHotJournal = 1;          /* True if there exists a hot journal-file */
 
     assert( !MEMDB );
-    assert( pPager->noReadlock==0 || pPager->readOnly );
+    assert( pPager->tempFile==0 || pPager->eLock==EXCLUSIVE_LOCK );
 
-    if( pPager->noReadlock==0 ){
-      rc = pager_wait_on_lock(pPager, SHARED_LOCK);
-      if( rc!=SQLITE_OK ){
-        assert( pPager->eLock==NO_LOCK || pPager->eLock==UNKNOWN_LOCK );
-        goto failed;
-      }
+    rc = pager_wait_on_lock(pPager, SHARED_LOCK);
+    if( rc!=SQLITE_OK ){
+      assert( pPager->eLock==NO_LOCK || pPager->eLock==UNKNOWN_LOCK );
+      goto failed;
     }
 
     /* If a journal file exists, and there is no RESERVED lock on the
@@ -42060,6 +51341,11 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
       goto failed;
     }
     if( bHotJournal ){
+      if( pPager->readOnly ){
+        rc = SQLITE_READONLY_ROLLBACK;
+        goto failed;
+      }
+
       /* Get an EXCLUSIVE lock on the database file. At this point it is
       ** important that a RESERVED lock is not obtained on the way to the
       ** EXCLUSIVE lock. If it were, another process might open the
@@ -42123,7 +51409,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
         assert( rc==SQLITE_OK );
         rc = pagerSyncHotJournal(pPager);
         if( rc==SQLITE_OK ){
-          rc = pager_playback(pPager, 1);
+          rc = pager_playback(pPager, !pPager->tempFile);
           pPager->eState = PAGER_OPEN;
         }
       }else if( !pPager->exclusiveMode ){
@@ -42157,16 +51443,14 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
       );
     }
 
-    if( !pPager->tempFile 
-     && (pPager->pBackup || sqlite3PcachePagecount(pPager->pPCache)>0) 
-    ){
-      /* The shared-lock has just been acquired on the database file
-      ** and there are already pages in the cache (from a previous
-      ** read or write transaction).  Check to see if the database
-      ** has been modified.  If the database has changed, flush the
-      ** cache.
+    if( !pPager->tempFile && pPager->hasHeldSharedLock ){
+      /* The shared-lock has just been acquired then check to
+      ** see if the database has been modified.  If the database has changed,
+      ** flush the cache.  The hasHeldSharedLock flag prevents this from
+      ** occurring on the very first access to a file, in order to save a
+      ** single unnecessary sqlite3OsRead() call at the start-up.
       **
-      ** Database changes is detected by looking at 15 bytes beginning
+      ** Database changes are detected by looking at 15 bytes beginning
       ** at offset 24 into the file.  The first 4 of these 16 bytes are
       ** a 32-bit counter that is incremented with each change.  The
       ** other bytes change randomly with each file change when
@@ -42185,7 +51469,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
       if( nPage>0 ){
         IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));
         rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);
-        if( rc!=SQLITE_OK ){
+        if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){
           goto failed;
         }
       }else{
@@ -42194,6 +51478,16 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
 
       if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
         pager_reset(pPager);
+
+        /* Unmap the database file. It is possible that external processes
+        ** may have truncated the database file and then extended it back
+        ** to its original size while this process was not holding a lock.
+        ** In this case there may exist a Pager.pMap mapping that appears
+        ** to be the right size but is not actually valid. Avoid this
+        ** possibility by unmapping the db here. */
+        if( USEFETCH(pPager) ){
+          sqlite3OsUnfetch(pPager->fd, 0, 0);
+        }
       }
     }
 
@@ -42211,7 +51505,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
     rc = pagerBeginReadTransaction(pPager);
   }
 
-  if( pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){
+  if( pPager->tempFile==0 && pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){
     rc = pagerPagecount(pPager, &pPager->dbSize);
   }
 
@@ -42222,6 +51516,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
     assert( pPager->eState==PAGER_OPEN );
   }else{
     pPager->eState = PAGER_READER;
+    pPager->hasHeldSharedLock = 1;
   }
   return rc;
 }
@@ -42235,7 +51530,7 @@ SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){
 ** nothing to rollback, so this routine is a no-op.
 */ 
 static void pagerUnlockIfUnused(Pager *pPager){
-  if( (sqlite3PcacheRefCount(pPager->pPCache)==0) ){
+  if( pPager->nMmapOut==0 && (sqlite3PcacheRefCount(pPager->pPCache)==0) ){
     pagerUnlockAndRollback(pPager);
   }
 }
@@ -42263,7 +51558,7 @@ static void pagerUnlockIfUnused(Pager *pPager){
 ** page is initialized to all zeros. 
 **
 ** If noContent is true, it means that we do not care about the contents
-** of the page. This occurs in two seperate scenarios:
+** of the page. This occurs in two scenarios:
 **
 **   a) When reading a free-list leaf page from the database, and
 **
@@ -42290,28 +51585,93 @@ static void pagerUnlockIfUnused(Pager *pPager){
 ** Since Lookup() never goes to disk, it never has to deal with locks
 ** or journal files.
 */
-SQLITE_PRIVATE int sqlite3PagerAcquire(
+SQLITE_PRIVATE int sqlite3PagerGet(
   Pager *pPager,      /* The pager open on the database file */
   Pgno pgno,          /* Page number to fetch */
   DbPage **ppPage,    /* Write a pointer to the page here */
-  int noContent       /* Do not bother reading content from disk if true */
+  int flags           /* PAGER_GET_XXX flags */
 ){
-  int rc;
-  PgHdr *pPg;
+  int rc = SQLITE_OK;
+  PgHdr *pPg = 0;
+  u32 iFrame = 0;                 /* Frame to read from WAL file */
+  const int noContent = (flags & PAGER_GET_NOCONTENT);
+
+  /* It is acceptable to use a read-only (mmap) page for any page except
+  ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY
+  ** flag was specified by the caller. And so long as the db is not a 
+  ** temporary or in-memory database.  */
+  const int bMmapOk = (pgno>1 && USEFETCH(pPager)
+   && (pPager->eState==PAGER_READER || (flags & PAGER_GET_READONLY))
+#ifdef SQLITE_HAS_CODEC
+   && pPager->xCodec==0
+#endif
+  );
 
+  /* Optimization note:  Adding the "pgno<=1" term before "pgno==0" here
+  ** allows the compiler optimizer to reuse the results of the "pgno>1"
+  ** test in the previous statement, and avoid testing pgno==0 in the
+  ** common case where pgno is large. */
+  if( pgno<=1 && pgno==0 ){
+    return SQLITE_CORRUPT_BKPT;
+  }
   assert( pPager->eState>=PAGER_READER );
   assert( assert_pager_state(pPager) );
+  assert( noContent==0 || bMmapOk==0 );
 
-  if( pgno==0 ){
-    return SQLITE_CORRUPT_BKPT;
-  }
+  assert( pPager->hasHeldSharedLock==1 );
 
   /* If the pager is in the error state, return an error immediately. 
   ** Otherwise, request the page from the PCache layer. */
   if( pPager->errCode!=SQLITE_OK ){
     rc = pPager->errCode;
   }else{
-    rc = sqlite3PcacheFetch(pPager->pPCache, pgno, 1, ppPage);
+    if( bMmapOk && pagerUseWal(pPager) ){
+      rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+      if( rc!=SQLITE_OK ) goto pager_acquire_err;
+    }
+
+    if( bMmapOk && iFrame==0 ){
+      void *pData = 0;
+
+      rc = sqlite3OsFetch(pPager->fd, 
+          (i64)(pgno-1) * pPager->pageSize, pPager->pageSize, &pData
+      );
+
+      if( rc==SQLITE_OK && pData ){
+        if( pPager->eState>PAGER_READER || pPager->tempFile ){
+          pPg = sqlite3PagerLookup(pPager, pgno);
+        }
+        if( pPg==0 ){
+          rc = pagerAcquireMapPage(pPager, pgno, pData, &pPg);
+        }else{
+          sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1)*pPager->pageSize, pData);
+        }
+        if( pPg ){
+          assert( rc==SQLITE_OK );
+          *ppPage = pPg;
+          return SQLITE_OK;
+        }
+      }
+      if( rc!=SQLITE_OK ){
+        goto pager_acquire_err;
+      }
+    }
+
+    {
+      sqlite3_pcache_page *pBase;
+      pBase = sqlite3PcacheFetch(pPager->pPCache, pgno, 3);
+      if( pBase==0 ){
+        rc = sqlite3PcacheFetchStress(pPager->pPCache, pgno, &pBase);
+        if( rc!=SQLITE_OK ) goto pager_acquire_err;
+        if( pBase==0 ){
+          pPg = *ppPage = 0;
+          rc = SQLITE_NOMEM_BKPT;
+          goto pager_acquire_err;
+        }
+      }
+      pPg = *ppPage = sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pBase);
+      assert( pPg!=0 );
+    }
   }
 
   if( rc!=SQLITE_OK ){
@@ -42321,21 +51681,21 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
     pPg = 0;
     goto pager_acquire_err;
   }
-  assert( (*ppPage)->pgno==pgno );
-  assert( (*ppPage)->pPager==pPager || (*ppPage)->pPager==0 );
+  assert( pPg==(*ppPage) );
+  assert( pPg->pgno==pgno );
+  assert( pPg->pPager==pPager || pPg->pPager==0 );
 
-  if( (*ppPage)->pPager && !noContent ){
+  if( pPg->pPager && !noContent ){
     /* In this case the pcache already contains an initialized copy of
     ** the page. Return without further ado.  */
     assert( pgno<=PAGER_MAX_PGNO && pgno!=PAGER_MJ_PGNO(pPager) );
-    pPager->nHit++;
+    pPager->aStat[PAGER_STAT_HIT]++;
     return SQLITE_OK;
 
   }else{
     /* The pager cache has created a new page. Its content needs to 
     ** be initialized.  */
 
-    pPg = *ppPage;
     pPg->pPager = pPager;
 
     /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
@@ -42345,7 +51705,8 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
       goto pager_acquire_err;
     }
 
-    if( MEMDB || pPager->dbSize<pgno || noContent || !isOpen(pPager->fd) ){
+    assert( !isOpen(pPager->fd) || !MEMDB );
+    if( !isOpen(pPager->fd) || pPager->dbSize<pgno || noContent ){
       if( pgno>pPager->mxPgno ){
         rc = SQLITE_FULL;
         goto pager_acquire_err;
@@ -42369,9 +51730,13 @@ SQLITE_PRIVATE int sqlite3PagerAcquire(
       memset(pPg->pData, 0, pPager->pageSize);
       IOTRACE(("ZERO %p %d\n", pPager, pgno));
     }else{
+      if( pagerUseWal(pPager) && bMmapOk==0 ){
+        rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
+        if( rc!=SQLITE_OK ) goto pager_acquire_err;
+      }
       assert( pPg->pPager==pPager );
-      pPager->nMiss++;
-      rc = readDbPage(pPg);
+      pPager->aStat[PAGER_STAT_MISS]++;
+      rc = readDbPage(pPg, iFrame);
       if( rc!=SQLITE_OK ){
         goto pager_acquire_err;
       }
@@ -42404,13 +51769,14 @@ pager_acquire_err:
 ** has ever happened.
 */
 SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
-  PgHdr *pPg = 0;
+  sqlite3_pcache_page *pPage;
   assert( pPager!=0 );
   assert( pgno!=0 );
   assert( pPager->pPCache!=0 );
-  assert( pPager->eState>=PAGER_READER && pPager->eState!=PAGER_ERROR );
-  sqlite3PcacheFetch(pPager->pPCache, pgno, 0, &pPg);
-  return pPg;
+  pPage = sqlite3PcacheFetch(pPager->pPCache, pgno, 0);
+  assert( pPage==0 || pPager->hasHeldSharedLock );
+  if( pPage==0 ) return 0;
+  return sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pPage);
 }
 
 /*
@@ -42421,12 +51787,19 @@ SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
 ** are released, a rollback occurs and the lock on the database is
 ** removed.
 */
-SQLITE_PRIVATE void sqlite3PagerUnref(DbPage *pPg){
-  if( pPg ){
-    Pager *pPager = pPg->pPager;
+SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage *pPg){
+  Pager *pPager;
+  assert( pPg!=0 );
+  pPager = pPg->pPager;
+  if( pPg->flags & PGHDR_MMAP ){
+    pagerReleaseMapPage(pPg);
+  }else{
     sqlite3PcacheRelease(pPg);
-    pagerUnlockIfUnused(pPager);
   }
+  pagerUnlockIfUnused(pPager);
+}
+SQLITE_PRIVATE void sqlite3PagerUnref(DbPage *pPg){
+  if( pPg ) sqlite3PagerUnrefNotNull(pPg);
 }
 
 /*
@@ -42467,7 +51840,7 @@ static int pager_open_journal(Pager *pPager){
   if( !pagerUseWal(pPager) && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
     pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);
     if( pPager->pInJournal==0 ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
   
     /* Open the journal file if it is not already open. */
@@ -42475,19 +51848,25 @@ static int pager_open_journal(Pager *pPager){
       if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){
         sqlite3MemJournalOpen(pPager->jfd);
       }else{
-        const int flags =                   /* VFS flags to open journal file */
-          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
-          (pPager->tempFile ? 
-            (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL):
-            (SQLITE_OPEN_MAIN_JOURNAL)
+        int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
+        int nSpill;
+
+        if( pPager->tempFile ){
+          flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);
+          nSpill = sqlite3Config.nStmtSpill;
+        }else{
+          flags |= SQLITE_OPEN_MAIN_JOURNAL;
+          nSpill = jrnlBufferSize(pPager);
+        }
+          
+        /* Verify that the database still has the same name as it did when
+        ** it was originally opened. */
+        rc = databaseIsUnmoved(pPager);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3JournalOpen (
+              pVfs, pPager->zJournal, pPager->jfd, flags, nSpill
           );
-  #ifdef SQLITE_ENABLE_ATOMIC_WRITE
-        rc = sqlite3JournalOpen(
-            pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
-        );
-  #else
-        rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
-  #endif
+        }
       }
       assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
     }
@@ -42553,7 +51932,7 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
         if( rc!=SQLITE_OK ){
           return rc;
         }
-        sqlite3WalExclusiveMode(pPager->pWal, 1);
+        (void)sqlite3WalExclusiveMode(pPager->pWal, 1);
       }
 
       /* Grab the write lock on the log file. If successful, upgrade to
@@ -42601,6 +51980,59 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
 }
 
 /*
+** Write page pPg onto the end of the rollback journal.
+*/
+static SQLITE_NOINLINE int pagerAddPageToRollbackJournal(PgHdr *pPg){
+  Pager *pPager = pPg->pPager;
+  int rc;
+  u32 cksum;
+  char *pData2;
+  i64 iOff = pPager->journalOff;
+
+  /* We should never write to the journal file the page that
+  ** contains the database locks.  The following assert verifies
+  ** that we do not. */
+  assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
+
+  assert( pPager->journalHdr<=pPager->journalOff );
+  CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
+  cksum = pager_cksum(pPager, (u8*)pData2);
+
+  /* Even if an IO or diskfull error occurs while journalling the
+  ** page in the block above, set the need-sync flag for the page.
+  ** Otherwise, when the transaction is rolled back, the logic in
+  ** playback_one_page() will think that the page needs to be restored
+  ** in the database file. And if an IO error occurs while doing so,
+  ** then corruption may follow.
+  */
+  pPg->flags |= PGHDR_NEED_SYNC;
+
+  rc = write32bits(pPager->jfd, iOff, pPg->pgno);
+  if( rc!=SQLITE_OK ) return rc;
+  rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
+  if( rc!=SQLITE_OK ) return rc;
+  rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
+  if( rc!=SQLITE_OK ) return rc;
+
+  IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
+           pPager->journalOff, pPager->pageSize));
+  PAGER_INCR(sqlite3_pager_writej_count);
+  PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
+       PAGERID(pPager), pPg->pgno, 
+       ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
+
+  pPager->journalOff += 8 + pPager->pageSize;
+  pPager->nRec++;
+  assert( pPager->pInJournal!=0 );
+  rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
+  testcase( rc==SQLITE_NOMEM );
+  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+  rc |= addToSavepointBitvecs(pPager, pPg->pgno);
+  assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+  return rc;
+}
+
+/*
 ** Mark a single data page as writeable. The page is written into the 
 ** main journal or sub-journal as required. If the page is written into
 ** one of the journals, the corresponding bit is set in the 
@@ -42608,7 +52040,6 @@ SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory
 ** of any open savepoints as appropriate.
 */
 static int pager_write(PgHdr *pPg){
-  void *pData = pPg->pData;
   Pager *pPager = pPg->pPager;
   int rc = SQLITE_OK;
 
@@ -42621,15 +52052,8 @@ static int pager_write(PgHdr *pPg){
        || pPager->eState==PAGER_WRITER_DBMOD
   );
   assert( assert_pager_state(pPager) );
-
-  /* If an error has been previously detected, report the same error
-  ** again. This should not happen, but the check provides robustness. */
-  if( NEVER(pPager->errCode) )  return pPager->errCode;
-
-  /* Higher-level routines never call this function if database is not
-  ** writable.  But check anyway, just for robustness. */
-  if( NEVER(pPager->readOnly) ) return SQLITE_PERM;
-
+  assert( pPager->errCode==0 );
+  assert( pPager->readOnly==0 );
   CHECK_PAGE(pPg);
 
   /* The journal file needs to be opened. Higher level routines have already
@@ -42648,93 +52072,142 @@ static int pager_write(PgHdr *pPg){
   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );
   assert( assert_pager_state(pPager) );
 
-  /* Mark the page as dirty.  If the page has already been written
-  ** to the journal then we can return right away.
-  */
+  /* Mark the page that is about to be modified as dirty. */
   sqlite3PcacheMakeDirty(pPg);
-  if( pageInJournal(pPg) && !subjRequiresPage(pPg) ){
-    assert( !pagerUseWal(pPager) );
-  }else{
-  
-    /* The transaction journal now exists and we have a RESERVED or an
-    ** EXCLUSIVE lock on the main database file.  Write the current page to
-    ** the transaction journal if it is not there already.
-    */
-    if( !pageInJournal(pPg) && !pagerUseWal(pPager) ){
-      assert( pagerUseWal(pPager)==0 );
-      if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){
-        u32 cksum;
-        char *pData2;
-        i64 iOff = pPager->journalOff;
-
-        /* We should never write to the journal file the page that
-        ** contains the database locks.  The following assert verifies
-        ** that we do not. */
-        assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
-
-        assert( pPager->journalHdr<=pPager->journalOff );
-        CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
-        cksum = pager_cksum(pPager, (u8*)pData2);
-
-        /* Even if an IO or diskfull error occurs while journalling the
-        ** page in the block above, set the need-sync flag for the page.
-        ** Otherwise, when the transaction is rolled back, the logic in
-        ** playback_one_page() will think that the page needs to be restored
-        ** in the database file. And if an IO error occurs while doing so,
-        ** then corruption may follow.
-        */
+
+  /* If a rollback journal is in use, them make sure the page that is about
+  ** to change is in the rollback journal, or if the page is a new page off
+  ** then end of the file, make sure it is marked as PGHDR_NEED_SYNC.
+  */
+  assert( (pPager->pInJournal!=0) == isOpen(pPager->jfd) );
+  if( pPager->pInJournal!=0
+   && sqlite3BitvecTestNotNull(pPager->pInJournal, pPg->pgno)==0
+  ){
+    assert( pagerUseWal(pPager)==0 );
+    if( pPg->pgno<=pPager->dbOrigSize ){
+      rc = pagerAddPageToRollbackJournal(pPg);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+    }else{
+      if( pPager->eState!=PAGER_WRITER_DBMOD ){
         pPg->flags |= PGHDR_NEED_SYNC;
+      }
+      PAGERTRACE(("APPEND %d page %d needSync=%d\n",
+              PAGERID(pPager), pPg->pgno,
+             ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
+    }
+  }
 
-        rc = write32bits(pPager->jfd, iOff, pPg->pgno);
-        if( rc!=SQLITE_OK ) return rc;
-        rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);
-        if( rc!=SQLITE_OK ) return rc;
-        rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);
-        if( rc!=SQLITE_OK ) return rc;
+  /* The PGHDR_DIRTY bit is set above when the page was added to the dirty-list
+  ** and before writing the page into the rollback journal.  Wait until now,
+  ** after the page has been successfully journalled, before setting the
+  ** PGHDR_WRITEABLE bit that indicates that the page can be safely modified.
+  */
+  pPg->flags |= PGHDR_WRITEABLE;
+  
+  /* If the statement journal is open and the page is not in it,
+  ** then write the page into the statement journal.
+  */
+  if( pPager->nSavepoint>0 ){
+    rc = subjournalPageIfRequired(pPg);
+  }
 
-        IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 
-                 pPager->journalOff, pPager->pageSize));
-        PAGER_INCR(sqlite3_pager_writej_count);
-        PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",
-             PAGERID(pPager), pPg->pgno, 
-             ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));
-
-        pPager->journalOff += 8 + pPager->pageSize;
-        pPager->nRec++;
-        assert( pPager->pInJournal!=0 );
-        rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);
-        testcase( rc==SQLITE_NOMEM );
-        assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
-        rc |= addToSavepointBitvecs(pPager, pPg->pgno);
-        if( rc!=SQLITE_OK ){
-          assert( rc==SQLITE_NOMEM );
-          return rc;
-        }
-      }else{
-        if( pPager->eState!=PAGER_WRITER_DBMOD ){
-          pPg->flags |= PGHDR_NEED_SYNC;
+  /* Update the database size and return. */
+  if( pPager->dbSize<pPg->pgno ){
+    pPager->dbSize = pPg->pgno;
+  }
+  return rc;
+}
+
+/*
+** This is a variant of sqlite3PagerWrite() that runs when the sector size
+** is larger than the page size.  SQLite makes the (reasonable) assumption that
+** all bytes of a sector are written together by hardware.  Hence, all bytes of
+** a sector need to be journalled in case of a power loss in the middle of
+** a write.
+**
+** Usually, the sector size is less than or equal to the page size, in which
+** case pages can be individually written.  This routine only runs in the
+** exceptional case where the page size is smaller than the sector size.
+*/
+static SQLITE_NOINLINE int pagerWriteLargeSector(PgHdr *pPg){
+  int rc = SQLITE_OK;          /* Return code */
+  Pgno nPageCount;             /* Total number of pages in database file */
+  Pgno pg1;                    /* First page of the sector pPg is located on. */
+  int nPage = 0;               /* Number of pages starting at pg1 to journal */
+  int ii;                      /* Loop counter */
+  int needSync = 0;            /* True if any page has PGHDR_NEED_SYNC */
+  Pager *pPager = pPg->pPager; /* The pager that owns pPg */
+  Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
+
+  /* Set the doNotSpill NOSYNC bit to 1. This is because we cannot allow
+  ** a journal header to be written between the pages journaled by
+  ** this function.
+  */
+  assert( !MEMDB );
+  assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)==0 );
+  pPager->doNotSpill |= SPILLFLAG_NOSYNC;
+
+  /* This trick assumes that both the page-size and sector-size are
+  ** an integer power of 2. It sets variable pg1 to the identifier
+  ** of the first page of the sector pPg is located on.
+  */
+  pg1 = ((pPg->pgno-1) & ~(nPagePerSector-1)) + 1;
+
+  nPageCount = pPager->dbSize;
+  if( pPg->pgno>nPageCount ){
+    nPage = (pPg->pgno - pg1)+1;
+  }else if( (pg1+nPagePerSector-1)>nPageCount ){
+    nPage = nPageCount+1-pg1;
+  }else{
+    nPage = nPagePerSector;
+  }
+  assert(nPage>0);
+  assert(pg1<=pPg->pgno);
+  assert((pg1+nPage)>pPg->pgno);
+
+  for(ii=0; ii<nPage && rc==SQLITE_OK; ii++){
+    Pgno pg = pg1+ii;
+    PgHdr *pPage;
+    if( pg==pPg->pgno || !sqlite3BitvecTest(pPager->pInJournal, pg) ){
+      if( pg!=PAGER_MJ_PGNO(pPager) ){
+        rc = sqlite3PagerGet(pPager, pg, &pPage, 0);
+        if( rc==SQLITE_OK ){
+          rc = pager_write(pPage);
+          if( pPage->flags&PGHDR_NEED_SYNC ){
+            needSync = 1;
+          }
+          sqlite3PagerUnrefNotNull(pPage);
         }
-        PAGERTRACE(("APPEND %d page %d needSync=%d\n",
-                PAGERID(pPager), pPg->pgno,
-               ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));
       }
-    }
-  
-    /* If the statement journal is open and the page is not in it,
-    ** then write the current page to the statement journal.  Note that
-    ** the statement journal format differs from the standard journal format
-    ** in that it omits the checksums and the header.
-    */
-    if( subjRequiresPage(pPg) ){
-      rc = subjournalPage(pPg);
+    }else if( (pPage = sqlite3PagerLookup(pPager, pg))!=0 ){
+      if( pPage->flags&PGHDR_NEED_SYNC ){
+        needSync = 1;
+      }
+      sqlite3PagerUnrefNotNull(pPage);
     }
   }
 
-  /* Update the database size and return.
+  /* If the PGHDR_NEED_SYNC flag is set for any of the nPage pages 
+  ** starting at pg1, then it needs to be set for all of them. Because
+  ** writing to any of these nPage pages may damage the others, the
+  ** journal file must contain sync()ed copies of all of them
+  ** before any of them can be written out to the database file.
   */
-  if( pPager->dbSize<pPg->pgno ){
-    pPager->dbSize = pPg->pgno;
+  if( rc==SQLITE_OK && needSync ){
+    assert( !MEMDB );
+    for(ii=0; ii<nPage; ii++){
+      PgHdr *pPage = sqlite3PagerLookup(pPager, pg1+ii);
+      if( pPage ){
+        pPage->flags |= PGHDR_NEED_SYNC;
+        sqlite3PagerUnrefNotNull(pPage);
+      }
+    }
   }
+
+  assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)!=0 );
+  pPager->doNotSpill &= ~SPILLFLAG_NOSYNC;
   return rc;
 }
 
@@ -42752,95 +52225,22 @@ static int pager_write(PgHdr *pPg){
 ** If an error occurs, SQLITE_NOMEM or an IO error code is returned
 ** as appropriate. Otherwise, SQLITE_OK.
 */
-SQLITE_PRIVATE int sqlite3PagerWrite(DbPage *pDbPage){
-  int rc = SQLITE_OK;
-
-  PgHdr *pPg = pDbPage;
+SQLITE_PRIVATE int sqlite3PagerWrite(PgHdr *pPg){
   Pager *pPager = pPg->pPager;
-  Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
-
+  assert( (pPg->flags & PGHDR_MMAP)==0 );
   assert( pPager->eState>=PAGER_WRITER_LOCKED );
-  assert( pPager->eState!=PAGER_ERROR );
   assert( assert_pager_state(pPager) );
-
-  if( nPagePerSector>1 ){
-    Pgno nPageCount;          /* Total number of pages in database file */
-    Pgno pg1;                 /* First page of the sector pPg is located on. */
-    int nPage = 0;            /* Number of pages starting at pg1 to journal */
-    int ii;                   /* Loop counter */
-    int needSync = 0;         /* True if any page has PGHDR_NEED_SYNC */
-
-    /* Set the doNotSyncSpill flag to 1. This is because we cannot allow
-    ** a journal header to be written between the pages journaled by
-    ** this function.
-    */
-    assert( !MEMDB );
-    assert( pPager->doNotSyncSpill==0 );
-    pPager->doNotSyncSpill++;
-
-    /* This trick assumes that both the page-size and sector-size are
-    ** an integer power of 2. It sets variable pg1 to the identifier
-    ** of the first page of the sector pPg is located on.
-    */
-    pg1 = ((pPg->pgno-1) & ~(nPagePerSector-1)) + 1;
-
-    nPageCount = pPager->dbSize;
-    if( pPg->pgno>nPageCount ){
-      nPage = (pPg->pgno - pg1)+1;
-    }else if( (pg1+nPagePerSector-1)>nPageCount ){
-      nPage = nPageCount+1-pg1;
-    }else{
-      nPage = nPagePerSector;
-    }
-    assert(nPage>0);
-    assert(pg1<=pPg->pgno);
-    assert((pg1+nPage)>pPg->pgno);
-
-    for(ii=0; ii<nPage && rc==SQLITE_OK; ii++){
-      Pgno pg = pg1+ii;
-      PgHdr *pPage;
-      if( pg==pPg->pgno || !sqlite3BitvecTest(pPager->pInJournal, pg) ){
-        if( pg!=PAGER_MJ_PGNO(pPager) ){
-          rc = sqlite3PagerGet(pPager, pg, &pPage);
-          if( rc==SQLITE_OK ){
-            rc = pager_write(pPage);
-            if( pPage->flags&PGHDR_NEED_SYNC ){
-              needSync = 1;
-            }
-            sqlite3PagerUnref(pPage);
-          }
-        }
-      }else if( (pPage = pager_lookup(pPager, pg))!=0 ){
-        if( pPage->flags&PGHDR_NEED_SYNC ){
-          needSync = 1;
-        }
-        sqlite3PagerUnref(pPage);
-      }
-    }
-
-    /* If the PGHDR_NEED_SYNC flag is set for any of the nPage pages 
-    ** starting at pg1, then it needs to be set for all of them. Because
-    ** writing to any of these nPage pages may damage the others, the
-    ** journal file must contain sync()ed copies of all of them
-    ** before any of them can be written out to the database file.
-    */
-    if( rc==SQLITE_OK && needSync ){
-      assert( !MEMDB );
-      for(ii=0; ii<nPage; ii++){
-        PgHdr *pPage = pager_lookup(pPager, pg1+ii);
-        if( pPage ){
-          pPage->flags |= PGHDR_NEED_SYNC;
-          sqlite3PagerUnref(pPage);
-        }
-      }
-    }
-
-    assert( pPager->doNotSyncSpill==1 );
-    pPager->doNotSyncSpill--;
+  if( pPager->errCode ){
+    return pPager->errCode;
+  }else if( (pPg->flags & PGHDR_WRITEABLE)!=0 && pPager->dbSize>=pPg->pgno ){
+    if( pPager->nSavepoint ) return subjournalPageIfRequired(pPg);
+    return SQLITE_OK;
+  }else if( pPager->sectorSize > (u32)pPager->pageSize ){
+    assert( pPager->tempFile==0 );
+    return pagerWriteLargeSector(pPg);
   }else{
-    rc = pager_write(pDbPage);
+    return pager_write(pPg);
   }
-  return rc;
 }
 
 /*
@@ -42850,7 +52250,7 @@ SQLITE_PRIVATE int sqlite3PagerWrite(DbPage *pDbPage){
 */
 #ifndef NDEBUG
 SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage *pPg){
-  return pPg->flags&PGHDR_DIRTY;
+  return pPg->flags & PGHDR_WRITEABLE;
 }
 #endif
 
@@ -42867,13 +52267,21 @@ SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage *pPg){
 **
 ** Tests show that this optimization can quadruple the speed of large 
 ** DELETE operations.
+**
+** This optimization cannot be used with a temp-file, as the page may
+** have been dirty at the start of the transaction. In that case, if
+** memory pressure forces page pPg out of the cache, the data does need 
+** to be written out to disk so that it may be read back in if the 
+** current transaction is rolled back.
 */
 SQLITE_PRIVATE void sqlite3PagerDontWrite(PgHdr *pPg){
   Pager *pPager = pPg->pPager;
-  if( (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){
+  if( !pPager->tempFile && (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){
     PAGERTRACE(("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager)));
     IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno))
     pPg->flags |= PGHDR_DONT_WRITE;
+    pPg->flags &= ~PGHDR_WRITEABLE;
+    testcase( pPg->flags & PGHDR_NEED_SYNC );
     pager_set_pagehash(pPg);
   }
 }
@@ -42926,13 +52334,13 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
 # define DIRECT_MODE isDirectMode
 #endif
 
-  if( !pPager->changeCountDone && pPager->dbSize>0 ){
+  if( !pPager->changeCountDone && ALWAYS(pPager->dbSize>0) ){
     PgHdr *pPgHdr;                /* Reference to page 1 */
 
     assert( !pPager->tempFile && isOpen(pPager->fd) );
 
     /* Open page 1 of the file for writing. */
-    rc = sqlite3PagerGet(pPager, 1, &pPgHdr);
+    rc = sqlite3PagerGet(pPager, 1, &pPgHdr, 0);
     assert( pPgHdr==0 || rc==SQLITE_OK );
 
     /* If page one was fetched successfully, and this function is not
@@ -42952,11 +52360,17 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
       if( DIRECT_MODE ){
         const void *zBuf;
         assert( pPager->dbFileSize>0 );
-        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM, zBuf);
+        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM_BKPT, zBuf);
         if( rc==SQLITE_OK ){
           rc = sqlite3OsWrite(pPager->fd, zBuf, pPager->pageSize, 0);
+          pPager->aStat[PAGER_STAT_WRITE]++;
         }
         if( rc==SQLITE_OK ){
+          /* Update the pager's copy of the change-counter. Otherwise, the
+          ** next time a read transaction is opened the cache will be
+          ** flushed (as the change-counter values will not match).  */
+          const void *pCopy = (const void *)&((const char *)zBuf)[24];
+          memcpy(&pPager->dbFileVers, pCopy, sizeof(pPager->dbFileVers));
           pPager->changeCountDone = 1;
         }
       }else{
@@ -42977,14 +52391,17 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
 ** If successful, or if called on a pager for which it is a no-op, this
 ** function returns SQLITE_OK. Otherwise, an IO error code is returned.
 */
-SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager){
+SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zMaster){
   int rc = SQLITE_OK;
-  if( !pPager->noSync ){
+
+  if( isOpen(pPager->fd) ){
+    void *pArg = (void*)zMaster;
+    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC, pArg);
+    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+  }
+  if( rc==SQLITE_OK && !pPager->noSync ){
     assert( !MEMDB );
     rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
-  }else if( isOpen(pPager->fd) ){
-    assert( !MEMDB );
-    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC_OMITTED, (void *)&rc);
   }
   return rc;
 }
@@ -43001,14 +52418,17 @@ SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager){
 ** returned.
 */
 SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager *pPager){
-  int rc = SQLITE_OK;
-  assert( pPager->eState==PAGER_WRITER_CACHEMOD 
-       || pPager->eState==PAGER_WRITER_DBMOD 
-       || pPager->eState==PAGER_WRITER_LOCKED 
-  );
+  int rc = pPager->errCode;
   assert( assert_pager_state(pPager) );
-  if( 0==pagerUseWal(pPager) ){
-    rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+  if( rc==SQLITE_OK ){
+    assert( pPager->eState==PAGER_WRITER_CACHEMOD 
+         || pPager->eState==PAGER_WRITER_DBMOD 
+         || pPager->eState==PAGER_WRITER_LOCKED 
+    );
+    assert( assert_pager_state(pPager) );
+    if( 0==pagerUseWal(pPager) ){
+      rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
+    }
   }
   return rc;
 }
@@ -43056,17 +52476,21 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
   /* If a prior error occurred, report that error again. */
   if( NEVER(pPager->errCode) ) return pPager->errCode;
 
+  /* Provide the ability to easily simulate an I/O error during testing */
+  if( sqlite3FaultSim(400) ) return SQLITE_IOERR;
+
   PAGERTRACE(("DATABASE SYNC: File=%s zMaster=%s nSize=%d\n", 
       pPager->zFilename, zMaster, pPager->dbSize));
 
   /* If no database changes have been made, return early. */
   if( pPager->eState<PAGER_WRITER_CACHEMOD ) return SQLITE_OK;
 
-  if( MEMDB ){
+  assert( MEMDB==0 || pPager->tempFile );
+  assert( isOpen(pPager->fd) || pPager->tempFile );
+  if( 0==pagerFlushOnCommit(pPager, 1) ){
     /* If this is an in-memory db, or no pages have been written to, or this
     ** function has already been called, it is mostly a no-op.  However, any
-    ** backup in progress needs to be restarted.
-    */
+    ** backup in progress needs to be restarted.  */
     sqlite3BackupRestart(pPager->pBackup);
   }else{
     if( pagerUseWal(pPager) ){
@@ -43075,15 +52499,13 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
       if( pList==0 ){
         /* Must have at least one page for the WAL commit flag.
         ** Ticket [2d1a5c67dfc2363e44f29d9bbd57f] 2011-05-18 */
-        rc = sqlite3PagerGet(pPager, 1, &pPageOne);
+        rc = sqlite3PagerGet(pPager, 1, &pPageOne, 0);
         pList = pPageOne;
         pList->pDirty = 0;
       }
       assert( rc==SQLITE_OK );
       if( ALWAYS(pList) ){
-        rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1, 
-            (pPager->fullSync ? pPager->syncFlags : 0)
-        );
+        rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1);
       }
       sqlite3PagerUnref(pPageOne);
       if( rc==SQLITE_OK ){
@@ -43142,38 +52564,6 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
   #endif
       if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
   
-      /* If this transaction has made the database smaller, then all pages
-      ** being discarded by the truncation must be written to the journal
-      ** file. This can only happen in auto-vacuum mode.
-      **
-      ** Before reading the pages with page numbers larger than the 
-      ** current value of Pager.dbSize, set dbSize back to the value
-      ** that it took at the start of the transaction. Otherwise, the
-      ** calls to sqlite3PagerGet() return zeroed pages instead of 
-      ** reading data from the database file.
-      */
-  #ifndef SQLITE_OMIT_AUTOVACUUM
-      if( pPager->dbSize<pPager->dbOrigSize 
-       && pPager->journalMode!=PAGER_JOURNALMODE_OFF
-      ){
-        Pgno i;                                   /* Iterator variable */
-        const Pgno iSkip = PAGER_MJ_PGNO(pPager); /* Pending lock page */
-        const Pgno dbSize = pPager->dbSize;       /* Database image size */ 
-        pPager->dbSize = pPager->dbOrigSize;
-        for( i=dbSize+1; i<=pPager->dbOrigSize; i++ ){
-          if( !sqlite3BitvecTest(pPager->pInJournal, i) && i!=iSkip ){
-            PgHdr *pPage;             /* Page to journal */
-            rc = sqlite3PagerGet(pPager, i, &pPage);
-            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
-            rc = sqlite3PagerWrite(pPage);
-            sqlite3PagerUnref(pPage);
-            if( rc!=SQLITE_OK ) goto commit_phase_one_exit;
-          }
-        }
-        pPager->dbSize = dbSize;
-      } 
-  #endif
-  
       /* Write the master journal name into the journal file. If a master 
       ** journal file name has already been written to the journal file, 
       ** or if zMaster is NULL (no master journal), then this call is a no-op.
@@ -43201,11 +52591,14 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
         goto commit_phase_one_exit;
       }
       sqlite3PcacheCleanAll(pPager->pPCache);
-  
-      /* If the file on disk is not the same size as the database image,
-      ** then use pager_truncate to grow or shrink the file here.
-      */
-      if( pPager->dbSize!=pPager->dbFileSize ){
+
+      /* If the file on disk is smaller than the database image, use 
+      ** pager_truncate to grow the file here. This can happen if the database
+      ** image was extended as part of the current transaction and then the
+      ** last page in the db image moved to the free-list. In this case the
+      ** last page is never written out to disk, leaving the database file
+      ** undersized. Fix this now if it is the case.  */
+      if( pPager->dbSize>pPager->dbFileSize ){
         Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));
         assert( pPager->eState==PAGER_WRITER_DBMOD );
         rc = pager_truncate(pPager, nNew);
@@ -43214,7 +52607,7 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
   
       /* Finally, sync the database file. */
       if( !noSync ){
-        rc = sqlite3PagerSync(pPager);
+        rc = sqlite3PagerSync(pPager, zMaster);
       }
       IOTRACE(("DBSYNC %p\n", pPager))
     }
@@ -43278,7 +52671,8 @@ SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager *pPager){
   }
 
   PAGERTRACE(("COMMIT %d\n", PAGERID(pPager)));
-  rc = pager_end_transaction(pPager, pPager->setMaster);
+  pPager->iDataVersion++;
+  rc = pager_end_transaction(pPager, pPager->setMaster, 1);
   return pager_error(pPager, rc);
 }
 
@@ -43323,11 +52717,11 @@ SQLITE_PRIVATE int sqlite3PagerRollback(Pager *pPager){
   if( pagerUseWal(pPager) ){
     int rc2;
     rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
-    rc2 = pager_end_transaction(pPager, pPager->setMaster);
+    rc2 = pager_end_transaction(pPager, pPager->setMaster, 0);
     if( rc==SQLITE_OK ) rc = rc2;
   }else if( !isOpen(pPager->jfd) || pPager->eState==PAGER_WRITER_LOCKED ){
     int eState = pPager->eState;
-    rc = pager_end_transaction(pPager, 0);
+    rc = pager_end_transaction(pPager, 0, 0);
     if( !MEMDB && eState>PAGER_WRITER_LOCKED ){
       /* This can happen using journal_mode=off. Move the pager to the error 
       ** state to indicate that the contents of the cache may not be trusted.
@@ -43342,7 +52736,10 @@ SQLITE_PRIVATE int sqlite3PagerRollback(Pager *pPager){
   }
 
   assert( pPager->eState==PAGER_READER || rc!=SQLITE_OK );
-  assert( rc==SQLITE_OK || rc==SQLITE_FULL || (rc&0xFF)==SQLITE_IOERR );
+  assert( rc==SQLITE_OK || rc==SQLITE_FULL || rc==SQLITE_CORRUPT
+          || rc==SQLITE_NOMEM || (rc&0xFF)==SQLITE_IOERR 
+          || rc==SQLITE_CANTOPEN
+  );
 
   /* If an error occurs during a ROLLBACK, we can no longer trust the pager
   ** cache. So call pager_error() on the way out to make any error persistent.
@@ -43358,12 +52755,14 @@ SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager *pPager){
   return pPager->readOnly;
 }
 
+#ifdef SQLITE_DEBUG
 /*
-** Return the number of references to the pager.
+** Return the sum of the reference counts for all pages held by pPager.
 */
 SQLITE_PRIVATE int sqlite3PagerRefcount(Pager *pPager){
   return sqlite3PcacheRefCount(pPager->pPCache);
 }
+#endif
 
 /*
 ** Return the approximate number of bytes of memory currently
@@ -43396,11 +52795,11 @@ SQLITE_PRIVATE int *sqlite3PagerStats(Pager *pPager){
   a[3] = pPager->eState==PAGER_OPEN ? -1 : (int) pPager->dbSize;
   a[4] = pPager->eState;
   a[5] = pPager->errCode;
-  a[6] = pPager->nHit;
-  a[7] = pPager->nMiss;
+  a[6] = pPager->aStat[PAGER_STAT_HIT];
+  a[7] = pPager->aStat[PAGER_STAT_MISS];
   a[8] = 0;  /* Used to be pPager->nOvfl */
   a[9] = pPager->nRead;
-  a[10] = pPager->nWrite;
+  a[10] = pPager->aStat[PAGER_STAT_WRITE];
   return a;
 }
 #endif
@@ -43413,28 +52812,27 @@ SQLITE_PRIVATE int *sqlite3PagerStats(Pager *pPager){
 ** returning.
 */
 SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *pPager, int eStat, int reset, int *pnVal){
-  int *piStat;
 
   assert( eStat==SQLITE_DBSTATUS_CACHE_HIT
        || eStat==SQLITE_DBSTATUS_CACHE_MISS
+       || eStat==SQLITE_DBSTATUS_CACHE_WRITE
   );
-  if( eStat==SQLITE_DBSTATUS_CACHE_HIT ){
-    piStat = &pPager->nHit;
-  }else{
-    piStat = &pPager->nMiss;
-  }
 
-  *pnVal += *piStat;
+  assert( SQLITE_DBSTATUS_CACHE_HIT+1==SQLITE_DBSTATUS_CACHE_MISS );
+  assert( SQLITE_DBSTATUS_CACHE_HIT+2==SQLITE_DBSTATUS_CACHE_WRITE );
+  assert( PAGER_STAT_HIT==0 && PAGER_STAT_MISS==1 && PAGER_STAT_WRITE==2 );
+
+  *pnVal += pPager->aStat[eStat - SQLITE_DBSTATUS_CACHE_HIT];
   if( reset ){
-    *piStat = 0;
+    pPager->aStat[eStat - SQLITE_DBSTATUS_CACHE_HIT] = 0;
   }
 }
 
 /*
-** Return true if this is an in-memory pager.
+** Return true if this is an in-memory or temp-file backed pager.
 */
 SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){
-  return MEMDB;
+  return pPager->tempFile;
 }
 
 /*
@@ -43447,54 +52845,62 @@ SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){
 ** occurs while opening the sub-journal file, then an IO error code is
 ** returned. Otherwise, SQLITE_OK.
 */
-SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
+static SQLITE_NOINLINE int pagerOpenSavepoint(Pager *pPager, int nSavepoint){
   int rc = SQLITE_OK;                       /* Return code */
   int nCurrent = pPager->nSavepoint;        /* Current number of savepoints */
+  int ii;                                   /* Iterator variable */
+  PagerSavepoint *aNew;                     /* New Pager.aSavepoint array */
 
   assert( pPager->eState>=PAGER_WRITER_LOCKED );
   assert( assert_pager_state(pPager) );
+  assert( nSavepoint>nCurrent && pPager->useJournal );
 
-  if( nSavepoint>nCurrent && pPager->useJournal ){
-    int ii;                                 /* Iterator variable */
-    PagerSavepoint *aNew;                   /* New Pager.aSavepoint array */
+  /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM
+  ** if the allocation fails. Otherwise, zero the new portion in case a 
+  ** malloc failure occurs while populating it in the for(...) loop below.
+  */
+  aNew = (PagerSavepoint *)sqlite3Realloc(
+      pPager->aSavepoint, sizeof(PagerSavepoint)*nSavepoint
+  );
+  if( !aNew ){
+    return SQLITE_NOMEM_BKPT;
+  }
+  memset(&aNew[nCurrent], 0, (nSavepoint-nCurrent) * sizeof(PagerSavepoint));
+  pPager->aSavepoint = aNew;
 
-    /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM
-    ** if the allocation fails. Otherwise, zero the new portion in case a 
-    ** malloc failure occurs while populating it in the for(...) loop below.
-    */
-    aNew = (PagerSavepoint *)sqlite3Realloc(
-        pPager->aSavepoint, sizeof(PagerSavepoint)*nSavepoint
-    );
-    if( !aNew ){
-      return SQLITE_NOMEM;
+  /* Populate the PagerSavepoint structures just allocated. */
+  for(ii=nCurrent; ii<nSavepoint; ii++){
+    aNew[ii].nOrig = pPager->dbSize;
+    if( isOpen(pPager->jfd) && pPager->journalOff>0 ){
+      aNew[ii].iOffset = pPager->journalOff;
+    }else{
+      aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
     }
-    memset(&aNew[nCurrent], 0, (nSavepoint-nCurrent) * sizeof(PagerSavepoint));
-    pPager->aSavepoint = aNew;
-
-    /* Populate the PagerSavepoint structures just allocated. */
-    for(ii=nCurrent; ii<nSavepoint; ii++){
-      aNew[ii].nOrig = pPager->dbSize;
-      if( isOpen(pPager->jfd) && pPager->journalOff>0 ){
-        aNew[ii].iOffset = pPager->journalOff;
-      }else{
-        aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);
-      }
-      aNew[ii].iSubRec = pPager->nSubRec;
-      aNew[ii].pInSavepoint = sqlite3BitvecCreate(pPager->dbSize);
-      if( !aNew[ii].pInSavepoint ){
-        return SQLITE_NOMEM;
-      }
-      if( pagerUseWal(pPager) ){
-        sqlite3WalSavepoint(pPager->pWal, aNew[ii].aWalData);
-      }
-      pPager->nSavepoint = ii+1;
+    aNew[ii].iSubRec = pPager->nSubRec;
+    aNew[ii].pInSavepoint = sqlite3BitvecCreate(pPager->dbSize);
+    if( !aNew[ii].pInSavepoint ){
+      return SQLITE_NOMEM_BKPT;
     }
-    assert( pPager->nSavepoint==nSavepoint );
-    assertTruncateConstraint(pPager);
+    if( pagerUseWal(pPager) ){
+      sqlite3WalSavepoint(pPager->pWal, aNew[ii].aWalData);
+    }
+    pPager->nSavepoint = ii+1;
   }
-
+  assert( pPager->nSavepoint==nSavepoint );
+  assertTruncateConstraint(pPager);
   return rc;
 }
+SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
+  assert( pPager->eState>=PAGER_WRITER_LOCKED );
+  assert( assert_pager_state(pPager) );
+
+  if( nSavepoint>pPager->nSavepoint && pPager->useJournal ){
+    return pagerOpenSavepoint(pPager, nSavepoint);
+  }else{
+    return SQLITE_OK;
+  }
+}
+
 
 /*
 ** This function is called to rollback or release (commit) a savepoint.
@@ -43551,7 +52957,7 @@ SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
     if( op==SAVEPOINT_RELEASE ){
       if( nNew==0 && isOpen(pPager->sjfd) ){
         /* Only truncate if it is an in-memory sub-journal. */
-        if( sqlite3IsMemJournal(pPager->sjfd) ){
+        if( sqlite3JournalIsInMemory(pPager->sjfd) ){
           rc = sqlite3OsTruncate(pPager->sjfd, 0);
           assert( rc==SQLITE_OK );
         }
@@ -43575,15 +52981,22 @@ SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
 
 /*
 ** Return the full pathname of the database file.
+**
+** Except, if the pager is in-memory only, then return an empty string if
+** nullIfMemDb is true.  This routine is called with nullIfMemDb==1 when
+** used to report the filename to the user, for compatibility with legacy
+** behavior.  But when the Btree needs to know the filename for matching to
+** shared cache, it uses nullIfMemDb==0 so that in-memory databases can
+** participate in shared-cache.
 */
-SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager *pPager){
-  return pPager->zFilename;
+SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager *pPager, int nullIfMemDb){
+  return (nullIfMemDb && pPager->memDb) ? "" : pPager->zFilename;
 }
 
 /*
 ** Return the VFS structure for the pager.
 */
-SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
+SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){
   return pPager->pVfs;
 }
 
@@ -43597,18 +53010,22 @@ SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager *pPager){
 }
 
 /*
-** Return the full pathname of the journal file.
+** Return the file handle for the journal file (if it exists).
+** This will be either the rollback journal or the WAL file.
 */
-SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager *pPager){
-  return pPager->zJournal;
+SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager *pPager){
+#if SQLITE_OMIT_WAL
+  return pPager->jfd;
+#else
+  return pPager->pWal ? sqlite3WalFile(pPager->pWal) : pPager->jfd;
+#endif
 }
 
 /*
-** Return true if fsync() calls are disabled for this pager.  Return FALSE
-** if fsync()s are executed normally.
+** Return the full pathname of the journal file.
 */
-SQLITE_PRIVATE int sqlite3PagerNosync(Pager *pPager){
-  return pPager->noSync;
+SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager *pPager){
+  return pPager->zJournal;
 }
 
 #ifdef SQLITE_HAS_CODEC
@@ -43632,7 +53049,27 @@ SQLITE_PRIVATE void sqlite3PagerSetCodec(
 SQLITE_PRIVATE void *sqlite3PagerGetCodec(Pager *pPager){
   return pPager->pCodec;
 }
-#endif
+
+/*
+** This function is called by the wal module when writing page content
+** into the log file.
+**
+** This function returns a pointer to a buffer containing the encrypted
+** page content. If a malloc fails, this function may return NULL.
+*/
+SQLITE_PRIVATE void *sqlite3PagerCodec(PgHdr *pPg){
+  void *aData = 0;
+  CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
+  return aData;
+}
+
+/*
+** Return the current pager state
+*/
+SQLITE_PRIVATE int sqlite3PagerState(Pager *pPager){
+  return pPager->eState;
+}
+#endif /* SQLITE_HAS_CODEC */
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
 /*
@@ -43675,7 +53112,8 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   /* In order to be able to rollback, an in-memory database must journal
   ** the page we are moving from.
   */
-  if( MEMDB ){
+  assert( pPager->tempFile || !MEMDB );
+  if( pPager->tempFile ){
     rc = sqlite3PagerWrite(pPg);
     if( rc ) return rc;
   }
@@ -43698,9 +53136,8 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   ** one or more savepoint bitvecs. This is the reason this function
   ** may return SQLITE_NOMEM.
   */
-  if( pPg->flags&PGHDR_DIRTY
-   && subjRequiresPage(pPg)
-   && SQLITE_OK!=(rc = subjournalPage(pPg))
+  if( (pPg->flags & PGHDR_DIRTY)!=0
+   && SQLITE_OK!=(rc = subjournalPageIfRequired(pPg))
   ){
     return rc;
   }
@@ -43718,7 +53155,8 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   */
   if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){
     needSyncPgno = pPg->pgno;
-    assert( pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );
+    assert( pPager->journalMode==PAGER_JOURNALMODE_OFF ||
+            pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize );
     assert( pPg->flags&PGHDR_DIRTY );
   }
 
@@ -43728,11 +53166,11 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   ** for the page moved there.
   */
   pPg->flags &= ~PGHDR_NEED_SYNC;
-  pPgOld = pager_lookup(pPager, pgno);
+  pPgOld = sqlite3PagerLookup(pPager, pgno);
   assert( !pPgOld || pPgOld->nRef==1 );
   if( pPgOld ){
     pPg->flags |= (pPgOld->flags&PGHDR_NEED_SYNC);
-    if( MEMDB ){
+    if( pPager->tempFile ){
       /* Do not discard pages from an in-memory database since we might
       ** need to rollback later.  Just move the page out of the way. */
       sqlite3PcacheMove(pPgOld, pPager->dbSize+1);
@@ -43749,10 +53187,9 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
   ** to exist, in case the transaction needs to roll back.  Use pPgOld
   ** as the original page since it has already been allocated.
   */
-  if( MEMDB ){
-    assert( pPgOld );
+  if( pPager->tempFile && pPgOld ){
     sqlite3PcacheMove(pPgOld, origPgno);
-    sqlite3PagerUnref(pPgOld);
+    sqlite3PagerUnrefNotNull(pPgOld);
   }
 
   if( needSyncPgno ){
@@ -43771,7 +53208,7 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
     ** the journal file twice, but that is not a problem.
     */
     PgHdr *pPgHdr;
-    rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr);
+    rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr, 0);
     if( rc!=SQLITE_OK ){
       if( needSyncPgno<=pPager->dbOrigSize ){
         assert( pPager->pTmpSpace!=0 );
@@ -43781,7 +53218,7 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
     }
     pPgHdr->flags |= PGHDR_NEED_SYNC;
     sqlite3PcacheMakeDirty(pPgHdr);
-    sqlite3PagerUnref(pPgHdr);
+    sqlite3PagerUnrefNotNull(pPgHdr);
   }
 
   return SQLITE_OK;
@@ -43789,6 +53226,18 @@ SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, i
 #endif
 
 /*
+** The page handle passed as the first argument refers to a dirty page 
+** with a page number other than iNew. This function changes the page's 
+** page number to iNew and sets the value of the PgHdr.flags field to 
+** the value passed as the third parameter.
+*/
+SQLITE_PRIVATE void sqlite3PagerRekey(DbPage *pPg, Pgno iNew, u16 flags){
+  assert( pPg->pgno!=iNew );
+  pPg->flags = flags;
+  sqlite3PcacheMove(pPg, iNew);
+}
+
+/*
 ** Return a pointer to the data for the specified page.
 */
 SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *pPg){
@@ -43933,6 +53382,8 @@ SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){
         }
         assert( state==pPager->eState );
       }
+    }else if( eMode==PAGER_JOURNALMODE_OFF ){
+      sqlite3OsClose(pPager->jfd);
     }
   }
 
@@ -43983,6 +53434,17 @@ SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
   return &pPager->pBackup;
 }
 
+#ifndef SQLITE_OMIT_VACUUM
+/*
+** Unless this is an in-memory or temporary database, clear the pager cache.
+*/
+SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){
+  assert( MEMDB==0 || pPager->tempFile );
+  if( pPager->tempFile==0 ) pager_reset(pPager);
+}
+#endif
+
+
 #ifndef SQLITE_OMIT_WAL
 /*
 ** This function is called when the user invokes "PRAGMA wal_checkpoint",
@@ -43995,7 +53457,8 @@ SQLITE_PRIVATE int sqlite3PagerCheckpoint(Pager *pPager, int eMode, int *pnLog,
   int rc = SQLITE_OK;
   if( pPager->pWal ){
     rc = sqlite3WalCheckpoint(pPager->pWal, eMode,
-        pPager->xBusyHandler, pPager->pBusyHandlerArg,
+        (eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),
+        pPager->pBusyHandlerArg,
         pPager->ckptSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
         pnLog, pnCkpt
     );
@@ -44013,6 +53476,7 @@ SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager){
 */
 SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager){
   const sqlite3_io_methods *pMethods = pPager->fd->pMethods;
+  if( pPager->noLock ) return 0;
   return pPager->exclusiveMode || (pMethods->iVersion>=2 && pMethods->xShmMap);
 }
 
@@ -44044,7 +53508,7 @@ static int pagerOpenWal(Pager *pPager){
   int rc = SQLITE_OK;
 
   assert( pPager->pWal==0 && pPager->tempFile==0 );
-  assert( pPager->eLock==SHARED_LOCK || pPager->eLock==EXCLUSIVE_LOCK || pPager->noReadlock);
+  assert( pPager->eLock==SHARED_LOCK || pPager->eLock==EXCLUSIVE_LOCK );
 
   /* If the pager is already in exclusive-mode, the WAL module will use 
   ** heap-memory for the wal-index instead of the VFS shared-memory 
@@ -44059,11 +53523,12 @@ static int pagerOpenWal(Pager *pPager){
   ** (e.g. due to malloc() failure), return an error code.
   */
   if( rc==SQLITE_OK ){
-    rc = sqlite3WalOpen(pPager->pVfs, 
+    rc = sqlite3WalOpen(pPager->pVfs,
         pPager->fd, pPager->zWal, pPager->exclusiveMode,
         pPager->journalSizeLimit, &pPager->pWal
     );
   }
+  pagerFixMaplimit(pPager);
 
   return rc;
 }
@@ -44154,35 +53619,57 @@ SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager){
       rc = sqlite3WalClose(pPager->pWal, pPager->ckptSyncFlags,
                            pPager->pageSize, (u8*)pPager->pTmpSpace);
       pPager->pWal = 0;
+      pagerFixMaplimit(pPager);
+      if( rc && !pPager->exclusiveMode ) pagerUnlockDb(pPager, SHARED_LOCK);
     }
   }
   return rc;
 }
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
 /*
-** Unless this is an in-memory or temporary database, clear the pager cache.
+** If this is a WAL database, obtain a snapshot handle for the snapshot
+** currently open. Otherwise, return an error.
 */
-SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){
-  if( !MEMDB && pPager->tempFile==0 ) pager_reset(pPager);
+SQLITE_PRIVATE int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot){
+  int rc = SQLITE_ERROR;
+  if( pPager->pWal ){
+    rc = sqlite3WalSnapshotGet(pPager->pWal, ppSnapshot);
+  }
+  return rc;
 }
 
-#ifdef SQLITE_HAS_CODEC
 /*
-** This function is called by the wal module when writing page content
-** into the log file.
-**
-** This function returns a pointer to a buffer containing the encrypted
-** page content. If a malloc fails, this function may return NULL.
+** If this is a WAL database, store a pointer to pSnapshot. Next time a
+** read transaction is opened, attempt to read from the snapshot it 
+** identifies. If this is not a WAL database, return an error.
 */
-SQLITE_PRIVATE void *sqlite3PagerCodec(PgHdr *pPg){
-  void *aData = 0;
-  CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
-  return aData;
+SQLITE_PRIVATE int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot){
+  int rc = SQLITE_OK;
+  if( pPager->pWal ){
+    sqlite3WalSnapshotOpen(pPager->pWal, pSnapshot);
+  }else{
+    rc = SQLITE_ERROR;
+  }
+  return rc;
 }
-#endif /* SQLITE_HAS_CODEC */
-
+#endif /* SQLITE_ENABLE_SNAPSHOT */
 #endif /* !SQLITE_OMIT_WAL */
 
+#ifdef SQLITE_ENABLE_ZIPVFS
+/*
+** A read-lock must be held on the pager when this function is called. If
+** the pager is in WAL mode and the WAL file currently contains one or more
+** frames, return the size in bytes of the page images stored within the
+** WAL frames. Otherwise, if this is not a WAL database or the WAL file
+** is empty, return 0.
+*/
+SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager){
+  assert( pPager->eState>=PAGER_READER );
+  return sqlite3WalFramesize(pPager->pWal);
+}
+#endif
+
 #endif /* SQLITE_OMIT_DISKIO */
 
 /************** End of pager.c ***********************************************/
@@ -44331,14 +53818,15 @@ SQLITE_PRIVATE void *sqlite3PagerCodec(PgHdr *pPg){
 ** byte order of the host computer.
 **
 ** The purpose of the wal-index is to answer this question quickly:  Given
-** a page number P, return the index of the last frame for page P in the WAL,
-** or return NULL if there are no frames for page P in the WAL.
+** a page number P and a maximum frame index M, return the index of the 
+** last frame in the wal before frame M for page P in the WAL, or return
+** NULL if there are no frames for page P in the WAL prior to M.
 **
 ** The wal-index consists of a header region, followed by an one or
 ** more index blocks.  
 **
 ** The wal-index header contains the total number of frames within the WAL
-** in the the mxFrame field.  
+** in the mxFrame field.
 **
 ** Each index block except for the first contains information on 
 ** HASHTABLE_NPAGE frames. The first index block contains information on
@@ -44430,6 +53918,7 @@ SQLITE_PRIVATE void *sqlite3PagerCodec(PgHdr *pPg){
 */
 #ifndef SQLITE_OMIT_WAL
 
+/* #include "wal.h" */
 
 /*
 ** Trace output macros
@@ -44459,7 +53948,8 @@ SQLITE_PRIVATE int sqlite3WalTrace = 0;
 
 /*
 ** Indices of various locking bytes.   WAL_NREADER is the number
-** of available reader locks and should be at least 3.
+** of available reader locks and should be at least 3.  The default
+** is SQLITE_SHM_NLOCK==8 and  WAL_NREADER==5.
 */
 #define WAL_WRITE_LOCK         0
 #define WAL_ALL_BUT_WRITE      1
@@ -44479,7 +53969,10 @@ typedef struct WalCkptInfo WalCkptInfo;
 ** The following object holds a copy of the wal-index header content.
 **
 ** The actual header in the wal-index consists of two copies of this
-** object.
+** object followed by one instance of the WalCkptInfo object.
+** For all versions of SQLite through 3.10.0 and probably beyond,
+** the locking bytes (WalCkptInfo.aLock) start at offset 120 and
+** the total header size is 136 bytes.
 **
 ** The szPage value can be any power of 2 between 512 and 32768, inclusive.
 ** Or it can be 1 to represent a 65536-byte page.  The latter case was
@@ -44512,6 +54005,16 @@ struct WalIndexHdr {
 ** However, a WAL_WRITE_LOCK thread can move the value of nBackfill from
 ** mxFrame back to zero when the WAL is reset.
 **
+** nBackfillAttempted is the largest value of nBackfill that a checkpoint
+** has attempted to achieve.  Normally nBackfill==nBackfillAtempted, however
+** the nBackfillAttempted is set before any backfilling is done and the
+** nBackfill is only set after all backfilling completes.  So if a checkpoint
+** crashes, nBackfillAttempted might be larger than nBackfill.  The
+** WalIndexHdr.mxFrame must never be less than nBackfillAttempted.
+**
+** The aLock[] field is a set of bytes used for locking.  These bytes should
+** never be read or written.
+**
 ** There is one entry in aReadMark[] for each reader lock.  If a reader
 ** holds read-lock K, then the value in aReadMark[K] is no greater than
 ** the mxFrame for that reader.  The value READMARK_NOT_USED (0xffffffff)
@@ -44551,6 +54054,9 @@ struct WalIndexHdr {
 struct WalCkptInfo {
   u32 nBackfill;                  /* Number of WAL frames backfilled into DB */
   u32 aReadMark[WAL_NREADER];     /* Reader marks */
+  u8 aLock[SQLITE_SHM_NLOCK];     /* Reserved space for locks */
+  u32 nBackfillAttempted;         /* WAL frames perhaps written, or maybe not */
+  u32 notUsed0;                   /* Available for future enhancements */
 };
 #define READMARK_NOT_USED  0xffffffff
 
@@ -44560,9 +54066,8 @@ struct WalCkptInfo {
 ** only support mandatory file-locks, we do not read or write data
 ** from the region of the file on which locks are applied.
 */
-#define WALINDEX_LOCK_OFFSET   (sizeof(WalIndexHdr)*2 + sizeof(WalCkptInfo))
-#define WALINDEX_LOCK_RESERVED 16
-#define WALINDEX_HDR_SIZE      (WALINDEX_LOCK_OFFSET+WALINDEX_LOCK_RESERVED)
+#define WALINDEX_LOCK_OFFSET (sizeof(WalIndexHdr)*2+offsetof(WalCkptInfo,aLock))
+#define WALINDEX_HDR_SIZE    (sizeof(WalIndexHdr)*2+sizeof(WalCkptInfo))
 
 /* Size of header before each frame in wal */
 #define WAL_FRAME_HDRSIZE 24
@@ -44602,19 +54107,29 @@ struct Wal {
   u32 iCallback;             /* Value to pass to log callback (or 0) */
   i64 mxWalSize;             /* Truncate WAL to this size upon reset */
   int nWiData;               /* Size of array apWiData */
+  int szFirstBlock;          /* Size of first block written to WAL file */
   volatile u32 **apWiData;   /* Pointer to wal-index content in memory */
   u32 szPage;                /* Database page size */
   i16 readLock;              /* Which read lock is being held.  -1 for none */
+  u8 syncFlags;              /* Flags to use to sync header writes */
   u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */
   u8 writeLock;              /* True if in a write transaction */
   u8 ckptLock;               /* True if holding a checkpoint lock */
   u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
+  u8 truncateOnCommit;       /* True to truncate WAL file on commit */
+  u8 syncHeader;             /* Fsync the WAL header if true */
+  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
   WalIndexHdr hdr;           /* Wal-index header for current transaction */
+  u32 minFrame;              /* Ignore wal frames before this one */
+  u32 iReCksum;              /* On commit, recalculate checksums from here */
   const char *zWalName;      /* Name of WAL file */
   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
 #ifdef SQLITE_DEBUG
   u8 lockError;              /* True if a locking error has occurred */
 #endif
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  WalIndexHdr *pSnapshot;    /* Start transaction here if not NULL */
+#endif
 };
 
 /*
@@ -44704,10 +54219,10 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
   if( pWal->nWiData<=iPage ){
     int nByte = sizeof(u32*)*(iPage+1);
     volatile u32 **apNew;
-    apNew = (volatile u32 **)sqlite3_realloc((void *)pWal->apWiData, nByte);
+    apNew = (volatile u32 **)sqlite3_realloc64((void *)pWal->apWiData, nByte);
     if( !apNew ){
       *ppPage = 0;
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset((void*)&apNew[pWal->nWiData], 0,
            sizeof(u32*)*(iPage+1-pWal->nWiData));
@@ -44719,7 +54234,7 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
   if( pWal->apWiData[iPage]==0 ){
     if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
       pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
-      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM;
+      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;
     }else{
       rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
           pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
@@ -44756,7 +54271,7 @@ static volatile WalIndexHdr *walIndexHdr(Wal *pWal){
 ** The argument to this macro must be of type u32. On a little-endian
 ** architecture, it returns the u32 value that results from interpreting
 ** the 4 bytes as a big-endian value. On a big-endian architecture, it
-** returns the value that would be produced by intepreting the 4 bytes
+** returns the value that would be produced by interpreting the 4 bytes
 ** of the input value as a little-endian integer.
 */
 #define BYTESWAP32(x) ( \
@@ -44830,9 +54345,9 @@ static void walIndexWriteHdr(Wal *pWal){
   pWal->hdr.isInit = 1;
   pWal->hdr.iVersion = WALINDEX_MAX_VERSION;
   walChecksumBytes(1, (u8*)&pWal->hdr, nCksum, 0, pWal->hdr.aCksum);
-  memcpy((void *)&aHdr[1], (void *)&pWal->hdr, sizeof(WalIndexHdr));
+  memcpy((void*)&aHdr[1], (const void*)&pWal->hdr, sizeof(WalIndexHdr));
   walShmBarrier(pWal);
-  memcpy((void *)&aHdr[0], (void *)&pWal->hdr, sizeof(WalIndexHdr));
+  memcpy((void*)&aHdr[0], (const void*)&pWal->hdr, sizeof(WalIndexHdr));
 }
 
 /*
@@ -44860,14 +54375,18 @@ static void walEncodeFrame(
   assert( WAL_FRAME_HDRSIZE==24 );
   sqlite3Put4byte(&aFrame[0], iPage);
   sqlite3Put4byte(&aFrame[4], nTruncate);
-  memcpy(&aFrame[8], pWal->hdr.aSalt, 8);
+  if( pWal->iReCksum==0 ){
+    memcpy(&aFrame[8], pWal->hdr.aSalt, 8);
 
-  nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
-  walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
-  walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);
+    nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);
+    walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);
+    walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);
 
-  sqlite3Put4byte(&aFrame[16], aCksum[0]);
-  sqlite3Put4byte(&aFrame[20], aCksum[1]);
+    sqlite3Put4byte(&aFrame[16], aCksum[0]);
+    sqlite3Put4byte(&aFrame[20], aCksum[1]);
+  }else{
+    memset(&aFrame[8], 0, 16);
+  }
 }
 
 /*
@@ -45133,13 +54652,13 @@ static void walCleanupHash(Wal *pWal){
   ** via the hash table even after the cleanup.
   */
   if( iLimit ){
-    int i;           /* Loop counter */
+    int j;           /* Loop counter */
     int iKey;        /* Hash key */
-    for(i=1; i<=iLimit; i++){
-      for(iKey=walHash(aPgno[i]); aHash[iKey]; iKey=walNextHash(iKey)){
-        if( aHash[iKey]==i ) break;
+    for(j=1; j<=iLimit; j++){
+      for(iKey=walHash(aPgno[j]); aHash[iKey]; iKey=walNextHash(iKey)){
+        if( aHash[iKey]==j ) break;
       }
-      assert( aHash[iKey]==i );
+      assert( aHash[iKey]==j );
     }
   }
 #endif /* SQLITE_ENABLE_EXPENSIVE_ASSERT */
@@ -45170,7 +54689,7 @@ static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){
     assert( idx <= HASHTABLE_NSLOT/2 + 1 );
     
     /* If this is the first entry to be added to this hash-table, zero the
-    ** entire hash table and aPgno[] array before proceding. 
+    ** entire hash table and aPgno[] array before proceeding. 
     */
     if( idx==1 ){
       int nByte = (int)((u8 *)&aHash[HASHTABLE_NSLOT] - (u8 *)&aPgno[1]);
@@ -45281,6 +54800,7 @@ static int walIndexRecover(Wal *pWal){
     int szPage;                   /* Page size according to the log */
     u32 magic;                    /* Magic value read from WAL header */
     u32 version;                  /* Magic value read from WAL header */
+    int isValid;                  /* True if this frame is valid */
 
     /* Read in the WAL header. */
     rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);
@@ -45327,9 +54847,9 @@ static int walIndexRecover(Wal *pWal){
 
     /* Malloc a buffer to read frames into. */
     szFrame = szPage + WAL_FRAME_HDRSIZE;
-    aFrame = (u8 *)sqlite3_malloc(szFrame);
+    aFrame = (u8 *)sqlite3_malloc64(szFrame);
     if( !aFrame ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto recovery_error;
     }
     aData = &aFrame[WAL_FRAME_HDRSIZE];
@@ -45339,14 +54859,14 @@ static int walIndexRecover(Wal *pWal){
     for(iOffset=WAL_HDRSIZE; (iOffset+szFrame)<=nSize; iOffset+=szFrame){
       u32 pgno;                   /* Database page number for frame */
       u32 nTruncate;              /* dbsize field from frame header */
-      int isValid;                /* True if this frame is valid */
 
       /* Read and decode the next log frame. */
+      iFrame++;
       rc = sqlite3OsRead(pWal->pWalFd, aFrame, szFrame, iOffset);
       if( rc!=SQLITE_OK ) break;
       isValid = walDecodeFrame(pWal, &pgno, &nTruncate, aData, aFrame);
       if( !isValid ) break;
-      rc = walIndexAppend(pWal, ++iFrame, pgno);
+      rc = walIndexAppend(pWal, iFrame, pgno);
       if( rc!=SQLITE_OK ) break;
 
       /* If nTruncate is non-zero, this is a commit record. */
@@ -45378,8 +54898,10 @@ finished:
     */
     pInfo = walCkptInfo(pWal);
     pInfo->nBackfill = 0;
+    pInfo->nBackfillAttempted = pWal->hdr.mxFrame;
     pInfo->aReadMark[0] = 0;
     for(i=1; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;
+    if( pWal->hdr.mxFrame ) pInfo->aReadMark[1] = pWal->hdr.mxFrame;
 
     /* If more than one frame was recovered from the log file, report an
     ** event via sqlite3_log(). This is to help with identifying performance
@@ -45387,8 +54909,9 @@ finished:
     ** checkpointing the log file.
     */
     if( pWal->hdr.nPage ){
-      sqlite3_log(SQLITE_OK, "Recovered %d frames from WAL file %s",
-          pWal->hdr.nPage, pWal->zWalName
+      sqlite3_log(SQLITE_NOTICE_RECOVER_WAL,
+          "recovered %d frames from WAL file %s",
+          pWal->hdr.mxFrame, pWal->zWalName
       );
     }
   }
@@ -45447,7 +54970,11 @@ SQLITE_PRIVATE int sqlite3WalOpen(
   /* In the amalgamation, the os_unix.c and os_win.c source files come before
   ** this source file.  Verify that the #defines of the locking byte offsets
   ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value.
+  ** For that matter, if the lock offset ever changes from its initial design
+  ** value of 120, we need to know that so there is an assert() to check it.
   */
+  assert( 120==WALINDEX_LOCK_OFFSET );
+  assert( 136==WALINDEX_HDR_SIZE );
 #ifdef WIN_SHM_BASE
   assert( WIN_SHM_BASE==WALINDEX_LOCK_OFFSET );
 #endif
@@ -45460,7 +54987,7 @@ SQLITE_PRIVATE int sqlite3WalOpen(
   *ppWal = 0;
   pRet = (Wal*)sqlite3MallocZero(sizeof(Wal) + pVfs->szOsFile);
   if( !pRet ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   pRet->pVfs = pVfs;
@@ -45469,6 +54996,8 @@ SQLITE_PRIVATE int sqlite3WalOpen(
   pRet->readLock = -1;
   pRet->mxWalSize = mxWalSize;
   pRet->zWalName = zWalName;
+  pRet->syncHeader = 1;
+  pRet->padToSectorBoundary = 1;
   pRet->exclusiveMode = (bNoShm ? WAL_HEAPMEMORY_MODE: WAL_NORMAL_MODE);
 
   /* Open file handle on the write-ahead log file. */
@@ -45483,6 +55012,11 @@ SQLITE_PRIVATE int sqlite3WalOpen(
     sqlite3OsClose(pRet->pWalFd);
     sqlite3_free(pRet);
   }else{
+    int iDC = sqlite3OsDeviceCharacteristics(pDbFd);
+    if( iDC & SQLITE_IOCAP_SEQUENTIAL ){ pRet->syncHeader = 0; }
+    if( iDC & SQLITE_IOCAP_POWERSAFE_OVERWRITE ){
+      pRet->padToSectorBoundary = 0;
+    }
     *ppWal = pRet;
     WALTRACE(("WAL%d: opened\n", pRet));
   }
@@ -45631,7 +55165,7 @@ static void walMergesort(
   int nMerge = 0;                 /* Number of elements in list aMerge */
   ht_slot *aMerge = 0;            /* List to be merged */
   int iList;                      /* Index into input list */
-  int iSub = 0;                   /* Index into aSub array */
+  u32 iSub = 0;                   /* Index into aSub array */
   struct Sublist aSub[13];        /* Array of sub-lists */
 
   memset(aSub, 0, sizeof(aSub));
@@ -45642,7 +55176,9 @@ static void walMergesort(
     nMerge = 1;
     aMerge = &aList[iList];
     for(iSub=0; iList & (1<<iSub); iSub++){
-      struct Sublist *p = &aSub[iSub];
+      struct Sublist *p;
+      assert( iSub<ArraySize(aSub) );
+      p = &aSub[iSub];
       assert( p->aList && p->nList<=(1<<iSub) );
       assert( p->aList==&aList[iList&~((2<<iSub)-1)] );
       walMerge(aContent, p->aList, p->nList, &aMerge, &nMerge, aBuffer);
@@ -45653,7 +55189,9 @@ static void walMergesort(
 
   for(iSub++; iSub<ArraySize(aSub); iSub++){
     if( nList & (1<<iSub) ){
-      struct Sublist *p = &aSub[iSub];
+      struct Sublist *p;
+      assert( iSub<ArraySize(aSub) );
+      p = &aSub[iSub];
       assert( p->nList<=(1<<iSub) );
       assert( p->aList==&aList[nList&~((2<<iSub)-1)] );
       walMerge(aContent, p->aList, p->nList, &aMerge, &nMerge, aBuffer);
@@ -45676,7 +55214,7 @@ static void walMergesort(
 ** Free an iterator allocated by walIteratorInit().
 */
 static void walIteratorFree(WalIterator *p){
-  sqlite3ScratchFree(p);
+  sqlite3_free(p);
 }
 
 /*
@@ -45711,9 +55249,9 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
   nByte = sizeof(WalIterator) 
         + (nSegment-1)*sizeof(struct WalSegment)
         + iLast*sizeof(ht_slot);
-  p = (WalIterator *)sqlite3ScratchMalloc(nByte);
+  p = (WalIterator *)sqlite3_malloc64(nByte);
   if( !p ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   memset(p, 0, nByte);
   p->nSegment = nSegment;
@@ -45721,11 +55259,11 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
   /* Allocate temporary space used by the merge-sort routine. This block
   ** of memory will be freed before this function returns.
   */
-  aTmp = (ht_slot *)sqlite3ScratchMalloc(
+  aTmp = (ht_slot *)sqlite3_malloc64(
       sizeof(ht_slot) * (iLast>HASHTABLE_NPAGE?HASHTABLE_NPAGE:iLast)
   );
   if( !aTmp ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
 
   for(i=0; rc==SQLITE_OK && i<nSegment; i++){
@@ -45758,7 +55296,7 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
       p->aSegment[i].aPgno = (u32 *)aPgno;
     }
   }
-  sqlite3ScratchFree(aTmp);
+  sqlite3_free(aTmp);
 
   if( rc!=SQLITE_OK ){
     walIteratorFree(p);
@@ -45796,6 +55334,39 @@ static int walPagesize(Wal *pWal){
 }
 
 /*
+** The following is guaranteed when this function is called:
+**
+**   a) the WRITER lock is held,
+**   b) the entire log file has been checkpointed, and
+**   c) any existing readers are reading exclusively from the database
+**      file - there are no readers that may attempt to read a frame from
+**      the log file.
+**
+** This function updates the shared-memory structures so that the next
+** client to write to the database (which may be this one) does so by
+** writing frames into the start of the log file.
+**
+** The value of parameter salt1 is used as the aSalt[1] value in the 
+** new wal-index header. It should be passed a pseudo-random value (i.e. 
+** one obtained from sqlite3_randomness()).
+*/
+static void walRestartHdr(Wal *pWal, u32 salt1){
+  volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
+  int i;                          /* Loop counter */
+  u32 *aSalt = pWal->hdr.aSalt;   /* Big-endian salt values */
+  pWal->nCkpt++;
+  pWal->hdr.mxFrame = 0;
+  sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));
+  memcpy(&pWal->hdr.aSalt[1], &salt1, 4);
+  walIndexWriteHdr(pWal);
+  pInfo->nBackfill = 0;
+  pInfo->nBackfillAttempted = 0;
+  pInfo->aReadMark[1] = 0;
+  for(i=2; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;
+  assert( pInfo->aReadMark[0]==0 );
+}
+
+/*
 ** Copy as much content as we can from the WAL back into the database file
 ** in response to an sqlite3_wal_checkpoint() request or the equivalent.
 **
@@ -45818,7 +55389,7 @@ static int walPagesize(Wal *pWal){
 ** database file.
 **
 ** This routine uses and updates the nBackfill field of the wal-index header.
-** This is the only routine tha will increase the value of nBackfill.  
+** This is the only routine that will increase the value of nBackfill.  
 ** (A WAL reset or recovery will revert nBackfill to zero, but not increase
 ** its value.)
 **
@@ -45829,12 +55400,12 @@ static int walPagesize(Wal *pWal){
 static int walCheckpoint(
   Wal *pWal,                      /* Wal connection */
   int eMode,                      /* One of PASSIVE, FULL or RESTART */
-  int (*xBusyCall)(void*),        /* Function to call when busy */
+  int (*xBusy)(void*),            /* Function to call when busy */
   void *pBusyArg,                 /* Context argument for xBusyHandler */
   int sync_flags,                 /* Flags for OsSync() (or 0) */
   u8 *zBuf                        /* Temporary buffer to use */
 ){
-  int rc;                         /* Return code */
+  int rc = SQLITE_OK;             /* Return code */
   int szPage;                     /* Database page-size */
   WalIterator *pIter = 0;         /* Wal iterator context */
   u32 iDbpage = 0;                /* Next database page to write */
@@ -45843,122 +55414,156 @@ static int walCheckpoint(
   u32 mxPage;                     /* Max database page to write */
   int i;                          /* Loop counter */
   volatile WalCkptInfo *pInfo;    /* The checkpoint status information */
-  int (*xBusy)(void*) = 0;        /* Function to call when waiting for locks */
 
   szPage = walPagesize(pWal);
   testcase( szPage<=32768 );
   testcase( szPage>=65536 );
   pInfo = walCkptInfo(pWal);
-  if( pInfo->nBackfill>=pWal->hdr.mxFrame ) return SQLITE_OK;
+  if( pInfo->nBackfill<pWal->hdr.mxFrame ){
 
-  /* Allocate the iterator */
-  rc = walIteratorInit(pWal, &pIter);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-  assert( pIter );
+    /* Allocate the iterator */
+    rc = walIteratorInit(pWal, &pIter);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    assert( pIter );
 
-  if( eMode!=SQLITE_CHECKPOINT_PASSIVE ) xBusy = xBusyCall;
+    /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
+    ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
+    assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );
 
-  /* Compute in mxSafeFrame the index of the last frame of the WAL that is
-  ** safe to write into the database.  Frames beyond mxSafeFrame might
-  ** overwrite database pages that are in use by active readers and thus
-  ** cannot be backfilled from the WAL.
-  */
-  mxSafeFrame = pWal->hdr.mxFrame;
-  mxPage = pWal->hdr.nPage;
-  for(i=1; i<WAL_NREADER; i++){
-    u32 y = pInfo->aReadMark[i];
-    if( mxSafeFrame>y ){
-      assert( y<=pWal->hdr.mxFrame );
-      rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(i), 1);
-      if( rc==SQLITE_OK ){
-        pInfo->aReadMark[i] = READMARK_NOT_USED;
-        walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
-      }else if( rc==SQLITE_BUSY ){
-        mxSafeFrame = y;
-        xBusy = 0;
-      }else{
-        goto walcheckpoint_out;
+    /* Compute in mxSafeFrame the index of the last frame of the WAL that is
+    ** safe to write into the database.  Frames beyond mxSafeFrame might
+    ** overwrite database pages that are in use by active readers and thus
+    ** cannot be backfilled from the WAL.
+    */
+    mxSafeFrame = pWal->hdr.mxFrame;
+    mxPage = pWal->hdr.nPage;
+    for(i=1; i<WAL_NREADER; i++){
+      /* Thread-sanitizer reports that the following is an unsafe read,
+      ** as some other thread may be in the process of updating the value
+      ** of the aReadMark[] slot. The assumption here is that if that is
+      ** happening, the other client may only be increasing the value,
+      ** not decreasing it. So assuming either that either the "old" or
+      ** "new" version of the value is read, and not some arbitrary value
+      ** that would never be written by a real client, things are still 
+      ** safe.  */
+      u32 y = pInfo->aReadMark[i];
+      if( mxSafeFrame>y ){
+        assert( y<=pWal->hdr.mxFrame );
+        rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(i), 1);
+        if( rc==SQLITE_OK ){
+          pInfo->aReadMark[i] = (i==1 ? mxSafeFrame : READMARK_NOT_USED);
+          walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
+        }else if( rc==SQLITE_BUSY ){
+          mxSafeFrame = y;
+          xBusy = 0;
+        }else{
+          goto walcheckpoint_out;
+        }
       }
     }
-  }
 
-  if( pInfo->nBackfill<mxSafeFrame
-   && (rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(0), 1))==SQLITE_OK
-  ){
-    i64 nSize;                    /* Current size of database file */
-    u32 nBackfill = pInfo->nBackfill;
+    if( pInfo->nBackfill<mxSafeFrame
+     && (rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(0),1))==SQLITE_OK
+    ){
+      i64 nSize;                    /* Current size of database file */
+      u32 nBackfill = pInfo->nBackfill;
 
-    /* Sync the WAL to disk */
-    if( sync_flags ){
-      rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
-    }
+      pInfo->nBackfillAttempted = mxSafeFrame;
 
-    /* If the database file may grow as a result of this checkpoint, hint
-    ** about the eventual size of the db file to the VFS layer. 
-    */
-    if( rc==SQLITE_OK ){
-      i64 nReq = ((i64)mxPage * szPage);
-      rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);
-      if( rc==SQLITE_OK && nSize<nReq ){
-        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);
+      /* Sync the WAL to disk */
+      if( sync_flags ){
+        rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
       }
-    }
 
-    /* Iterate through the contents of the WAL, copying data to the db file. */
-    while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
-      i64 iOffset;
-      assert( walFramePgno(pWal, iFrame)==iDbpage );
-      if( iFrame<=nBackfill || iFrame>mxSafeFrame || iDbpage>mxPage ) continue;
-      iOffset = walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE;
-      /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL file */
-      rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);
-      if( rc!=SQLITE_OK ) break;
-      iOffset = (iDbpage-1)*(i64)szPage;
-      testcase( IS_BIG_INT(iOffset) );
-      rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);
-      if( rc!=SQLITE_OK ) break;
-    }
+      /* If the database may grow as a result of this checkpoint, hint
+      ** about the eventual size of the db file to the VFS layer.
+      */
+      if( rc==SQLITE_OK ){
+        i64 nReq = ((i64)mxPage * szPage);
+        rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);
+        if( rc==SQLITE_OK && nSize<nReq ){
+          sqlite3OsFileControlHint(pWal->pDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);
+        }
+      }
 
-    /* If work was actually accomplished... */
-    if( rc==SQLITE_OK ){
-      if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){
-        i64 szDb = pWal->hdr.nPage*(i64)szPage;
-        testcase( IS_BIG_INT(szDb) );
-        rc = sqlite3OsTruncate(pWal->pDbFd, szDb);
-        if( rc==SQLITE_OK && sync_flags ){
-          rc = sqlite3OsSync(pWal->pDbFd, sync_flags);
+
+      /* Iterate through the contents of the WAL, copying data to the db file */
+      while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
+        i64 iOffset;
+        assert( walFramePgno(pWal, iFrame)==iDbpage );
+        if( iFrame<=nBackfill || iFrame>mxSafeFrame || iDbpage>mxPage ){
+          continue;
         }
+        iOffset = walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE;
+        /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL file */
+        rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);
+        if( rc!=SQLITE_OK ) break;
+        iOffset = (iDbpage-1)*(i64)szPage;
+        testcase( IS_BIG_INT(iOffset) );
+        rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);
+        if( rc!=SQLITE_OK ) break;
       }
+
+      /* If work was actually accomplished... */
       if( rc==SQLITE_OK ){
-        pInfo->nBackfill = mxSafeFrame;
+        if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){
+          i64 szDb = pWal->hdr.nPage*(i64)szPage;
+          testcase( IS_BIG_INT(szDb) );
+          rc = sqlite3OsTruncate(pWal->pDbFd, szDb);
+          if( rc==SQLITE_OK && sync_flags ){
+            rc = sqlite3OsSync(pWal->pDbFd, sync_flags);
+          }
+        }
+        if( rc==SQLITE_OK ){
+          pInfo->nBackfill = mxSafeFrame;
+        }
       }
-    }
 
-    /* Release the reader lock held while backfilling */
-    walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);
-  }
+      /* Release the reader lock held while backfilling */
+      walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);
+    }
 
-  if( rc==SQLITE_BUSY ){
-    /* Reset the return code so as not to report a checkpoint failure
-    ** just because there are active readers.  */
-    rc = SQLITE_OK;
+    if( rc==SQLITE_BUSY ){
+      /* Reset the return code so as not to report a checkpoint failure
+      ** just because there are active readers.  */
+      rc = SQLITE_OK;
+    }
   }
 
-  /* If this is an SQLITE_CHECKPOINT_RESTART operation, and the entire wal
-  ** file has been copied into the database file, then block until all
-  ** readers have finished using the wal file. This ensures that the next
-  ** process to write to the database restarts the wal file.
+  /* If this is an SQLITE_CHECKPOINT_RESTART or TRUNCATE operation, and the
+  ** entire wal file has been copied into the database file, then block 
+  ** until all readers have finished using the wal file. This ensures that 
+  ** the next process to write to the database restarts the wal file.
   */
   if( rc==SQLITE_OK && eMode!=SQLITE_CHECKPOINT_PASSIVE ){
     assert( pWal->writeLock );
     if( pInfo->nBackfill<pWal->hdr.mxFrame ){
       rc = SQLITE_BUSY;
-    }else if( eMode==SQLITE_CHECKPOINT_RESTART ){
-      assert( mxSafeFrame==pWal->hdr.mxFrame );
+    }else if( eMode>=SQLITE_CHECKPOINT_RESTART ){
+      u32 salt1;
+      sqlite3_randomness(4, &salt1);
+      assert( pInfo->nBackfill==pWal->hdr.mxFrame );
       rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(1), WAL_NREADER-1);
       if( rc==SQLITE_OK ){
+        if( eMode==SQLITE_CHECKPOINT_TRUNCATE ){
+          /* IMPLEMENTATION-OF: R-44699-57140 This mode works the same way as
+          ** SQLITE_CHECKPOINT_RESTART with the addition that it also
+          ** truncates the log file to zero bytes just prior to a
+          ** successful return.
+          **
+          ** In theory, it might be safe to do this without updating the
+          ** wal-index header in shared memory, as all subsequent reader or
+          ** writer clients should see that the entire log file has been
+          ** checkpointed and behave accordingly. This seems unsafe though,
+          ** as it would leave the system in a state where the contents of
+          ** the wal-index header do not match the contents of the 
+          ** file-system. To avoid this, update the wal-index header to
+          ** indicate that the log file contains zero valid frames.  */
+          walRestartHdr(pWal, salt1);
+          rc = sqlite3OsTruncate(pWal->pWalFd, 0);
+        }
         walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
       }
     }
@@ -45970,6 +55575,24 @@ static int walCheckpoint(
 }
 
 /*
+** If the WAL file is currently larger than nMax bytes in size, truncate
+** it to exactly nMax bytes. If an error occurs while doing so, ignore it.
+*/
+static void walLimitSize(Wal *pWal, i64 nMax){
+  i64 sz;
+  int rx;
+  sqlite3BeginBenignMalloc();
+  rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
+  if( rx==SQLITE_OK && (sz > nMax ) ){
+    rx = sqlite3OsTruncate(pWal->pWalFd, nMax);
+  }
+  sqlite3EndBenignMalloc();
+  if( rx ){
+    sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
+  }
+}
+
+/*
 ** Close a connection to a log file.
 */
 SQLITE_PRIVATE int sqlite3WalClose(
@@ -45992,23 +55615,40 @@ SQLITE_PRIVATE int sqlite3WalClose(
     */
     rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE);
     if( rc==SQLITE_OK ){
-      int bPersistWal = -1;
       if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
         pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
       }
       rc = sqlite3WalCheckpoint(
           pWal, SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
       );
-      sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersistWal);
-      if( rc==SQLITE_OK && bPersistWal!=1 ){
-        isDelete = 1;
+      if( rc==SQLITE_OK ){
+        int bPersist = -1;
+        sqlite3OsFileControlHint(
+            pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersist
+        );
+        if( bPersist!=1 ){
+          /* Try to delete the WAL file if the checkpoint completed and
+          ** fsyned (rc==SQLITE_OK) and if we are not in persistent-wal
+          ** mode (!bPersist) */
+          isDelete = 1;
+        }else if( pWal->mxWalSize>=0 ){
+          /* Try to truncate the WAL file to zero bytes if the checkpoint
+          ** completed and fsynced (rc==SQLITE_OK) and we are in persistent
+          ** WAL mode (bPersist) and if the PRAGMA journal_size_limit is a
+          ** non-negative value (pWal->mxWalSize>=0).  Note that we truncate
+          ** to zero bytes as truncating to the journal_size_limit might
+          ** leave a corrupt WAL file on disk. */
+          walLimitSize(pWal, 0);
+        }
       }
     }
 
     walIndexClose(pWal, isDelete);
     sqlite3OsClose(pWal->pWalFd);
     if( isDelete ){
+      sqlite3BeginBenignMalloc();
       sqlite3OsDelete(pWal->pVfs, pWal->zWalName, 0);
+      sqlite3EndBenignMalloc();
     }
     WALTRACE(("WAL%p: closed\n", pWal));
     sqlite3_free((void *)pWal->apWiData);
@@ -46086,7 +55726,7 @@ static int walIndexTryHdr(Wal *pWal, int *pChanged){
 ** wal-index from the WAL before returning.
 **
 ** Set *pChanged to 1 if the wal-index header value in pWal->hdr is
-** changed by this opertion.  If pWal->hdr is unchanged, set *pChanged
+** changed by this operation.  If pWal->hdr is unchanged, set *pChanged
 ** to 0.
 **
 ** If the wal-index header is successfully read, return SQLITE_OK. 
@@ -46215,6 +55855,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   int mxI;                        /* Index of largest aReadMark[] value */
   int i;                          /* Loop counter */
   int rc = SQLITE_OK;             /* Return code  */
+  u32 mxFrame;                    /* Wal frame to lock to */
 
   assert( pWal->readLock<0 );     /* Not currently locked */
 
@@ -46232,8 +55873,8 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   ** calls to sqlite3OsSleep() have a delay of 1 microsecond.  Really this
   ** is more of a scheduler yield than an actual delay.  But on the 10th
   ** an subsequent retries, the delays start becoming longer and longer, 
-  ** so that on the 100th (and last) RETRY we delay for 21 milliseconds.
-  ** The total delay time before giving up is less than 1 second.
+  ** so that on the 100th (and last) RETRY we delay for 323 milliseconds.
+  ** The total delay time before giving up is less than 10 seconds.
   */
   if( cnt>5 ){
     int nDelay = 1;                      /* Pause time in microseconds */
@@ -46241,7 +55882,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
       VVA_ONLY( pWal->lockError = 1; )
       return SQLITE_PROTOCOL;
     }
-    if( cnt>=10 ) nDelay = (cnt-9)*238;  /* Max delay 21ms. Total delay 996ms */
+    if( cnt>=10 ) nDelay = (cnt-9)*(cnt-9)*39;
     sqlite3OsSleep(pWal->pVfs, nDelay);
   }
 
@@ -46278,7 +55919,12 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   }
 
   pInfo = walCkptInfo(pWal);
-  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame ){
+  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0
+     || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr)))
+#endif
+  ){
     /* The WAL has been completely backfilled (or it is empty).
     ** and can be safely ignored.
     */
@@ -46290,7 +55936,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
         ** may have been appended to the log before READ_LOCK(0) was obtained.
         ** When holding READ_LOCK(0), the reader ignores the entire log file,
         ** which implies that the database file contains a trustworthy
-        ** snapshoT. Since holding READ_LOCK(0) prevents a checkpoint from
+        ** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from
         ** happening, this is usually correct.
         **
         ** However, if frames have been appended to the log (or if the log 
@@ -46316,70 +55962,88 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   */
   mxReadMark = 0;
   mxI = 0;
+  mxFrame = pWal->hdr.mxFrame;
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  if( pWal->pSnapshot && pWal->pSnapshot->mxFrame<mxFrame ){
+    mxFrame = pWal->pSnapshot->mxFrame;
+  }
+#endif
   for(i=1; i<WAL_NREADER; i++){
     u32 thisMark = pInfo->aReadMark[i];
-    if( mxReadMark<=thisMark && thisMark<=pWal->hdr.mxFrame ){
+    if( mxReadMark<=thisMark && thisMark<=mxFrame ){
       assert( thisMark!=READMARK_NOT_USED );
       mxReadMark = thisMark;
       mxI = i;
     }
   }
-  /* There was once an "if" here. The extra "{" is to preserve indentation. */
-  {
-    if( (pWal->readOnly & WAL_SHM_RDONLY)==0
-     && (mxReadMark<pWal->hdr.mxFrame || mxI==0)
-    ){
-      for(i=1; i<WAL_NREADER; i++){
-        rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
-        if( rc==SQLITE_OK ){
-          mxReadMark = pInfo->aReadMark[i] = pWal->hdr.mxFrame;
-          mxI = i;
-          walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
-          break;
-        }else if( rc!=SQLITE_BUSY ){
-          return rc;
-        }
+  if( (pWal->readOnly & WAL_SHM_RDONLY)==0
+   && (mxReadMark<mxFrame || mxI==0)
+  ){
+    for(i=1; i<WAL_NREADER; i++){
+      rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
+      if( rc==SQLITE_OK ){
+        mxReadMark = pInfo->aReadMark[i] = mxFrame;
+        mxI = i;
+        walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
+        break;
+      }else if( rc!=SQLITE_BUSY ){
+        return rc;
       }
     }
-    if( mxI==0 ){
-      assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
-      return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
-    }
+  }
+  if( mxI==0 ){
+    assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
+    return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
+  }
 
-    rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
-    if( rc ){
-      return rc==SQLITE_BUSY ? WAL_RETRY : rc;
-    }
-    /* Now that the read-lock has been obtained, check that neither the
-    ** value in the aReadMark[] array or the contents of the wal-index
-    ** header have changed.
-    **
-    ** It is necessary to check that the wal-index header did not change
-    ** between the time it was read and when the shared-lock was obtained
-    ** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
-    ** that the log file may have been wrapped by a writer, or that frames
-    ** that occur later in the log than pWal->hdr.mxFrame may have been
-    ** copied into the database by a checkpointer. If either of these things
-    ** happened, then reading the database with the current value of
-    ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
-    ** instead.
-    **
-    ** This does not guarantee that the copy of the wal-index header is up to
-    ** date before proceeding. That would not be possible without somehow
-    ** blocking writers. It only guarantees that a dangerous checkpoint or 
-    ** log-wrap (either of which would require an exclusive lock on
-    ** WAL_READ_LOCK(mxI)) has not occurred since the snapshot was valid.
-    */
-    walShmBarrier(pWal);
-    if( pInfo->aReadMark[mxI]!=mxReadMark
-     || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
-    ){
-      walUnlockShared(pWal, WAL_READ_LOCK(mxI));
-      return WAL_RETRY;
-    }else{
-      assert( mxReadMark<=pWal->hdr.mxFrame );
-      pWal->readLock = (i16)mxI;
-    }
+  rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
+  if( rc ){
+    return rc==SQLITE_BUSY ? WAL_RETRY : rc;
+  }
+  /* Now that the read-lock has been obtained, check that neither the
+  ** value in the aReadMark[] array or the contents of the wal-index
+  ** header have changed.
+  **
+  ** It is necessary to check that the wal-index header did not change
+  ** between the time it was read and when the shared-lock was obtained
+  ** on WAL_READ_LOCK(mxI) was obtained to account for the possibility
+  ** that the log file may have been wrapped by a writer, or that frames
+  ** that occur later in the log than pWal->hdr.mxFrame may have been
+  ** copied into the database by a checkpointer. If either of these things
+  ** happened, then reading the database with the current value of
+  ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
+  ** instead.
+  **
+  ** Before checking that the live wal-index header has not changed
+  ** since it was read, set Wal.minFrame to the first frame in the wal
+  ** file that has not yet been checkpointed. This client will not need
+  ** to read any frames earlier than minFrame from the wal file - they
+  ** can be safely read directly from the database file.
+  **
+  ** Because a ShmBarrier() call is made between taking the copy of 
+  ** nBackfill and checking that the wal-header in shared-memory still
+  ** matches the one cached in pWal->hdr, it is guaranteed that the 
+  ** checkpointer that set nBackfill was not working with a wal-index
+  ** header newer than that cached in pWal->hdr. If it were, that could
+  ** cause a problem. The checkpointer could omit to checkpoint
+  ** a version of page X that lies before pWal->minFrame (call that version
+  ** A) on the basis that there is a newer version (version B) of the same
+  ** page later in the wal file. But if version B happens to like past
+  ** frame pWal->hdr.mxFrame - then the client would incorrectly assume
+  ** that it can read version A from the database file. However, since
+  ** we can guarantee that the checkpointer that set nBackfill could not
+  ** see any pages past pWal->hdr.mxFrame, this problem does not come up.
+  */
+  pWal->minFrame = pInfo->nBackfill+1;
+  walShmBarrier(pWal);
+  if( pInfo->aReadMark[mxI]!=mxReadMark
+   || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
+  ){
+    walUnlockShared(pWal, WAL_READ_LOCK(mxI));
+    return WAL_RETRY;
+  }else{
+    assert( mxReadMark<=pWal->hdr.mxFrame );
+    pWal->readLock = (i16)mxI;
   }
   return rc;
 }
@@ -46402,6 +56066,14 @@ SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
   int rc;                         /* Return code */
   int cnt = 0;                    /* Number of TryBeginRead attempts */
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  int bChanged = 0;
+  WalIndexHdr *pSnapshot = pWal->pSnapshot;
+  if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){
+    bChanged = 1;
+  }
+#endif
+
   do{
     rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);
   }while( rc==WAL_RETRY );
@@ -46409,6 +56081,66 @@ SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
   testcase( (rc&0xff)==SQLITE_IOERR );
   testcase( rc==SQLITE_PROTOCOL );
   testcase( rc==SQLITE_OK );
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+  if( rc==SQLITE_OK ){
+    if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){
+      /* At this point the client has a lock on an aReadMark[] slot holding
+      ** a value equal to or smaller than pSnapshot->mxFrame, but pWal->hdr
+      ** is populated with the wal-index header corresponding to the head
+      ** of the wal file. Verify that pSnapshot is still valid before
+      ** continuing.  Reasons why pSnapshot might no longer be valid:
+      **
+      **    (1)  The WAL file has been reset since the snapshot was taken.
+      **         In this case, the salt will have changed.
+      **
+      **    (2)  A checkpoint as been attempted that wrote frames past
+      **         pSnapshot->mxFrame into the database file.  Note that the
+      **         checkpoint need not have completed for this to cause problems.
+      */
+      volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
+
+      assert( pWal->readLock>0 || pWal->hdr.mxFrame==0 );
+      assert( pInfo->aReadMark[pWal->readLock]<=pSnapshot->mxFrame );
+
+      /* It is possible that there is a checkpointer thread running 
+      ** concurrent with this code. If this is the case, it may be that the
+      ** checkpointer has already determined that it will checkpoint 
+      ** snapshot X, where X is later in the wal file than pSnapshot, but 
+      ** has not yet set the pInfo->nBackfillAttempted variable to indicate 
+      ** its intent. To avoid the race condition this leads to, ensure that
+      ** there is no checkpointer process by taking a shared CKPT lock 
+      ** before checking pInfo->nBackfillAttempted.  */
+      rc = walLockShared(pWal, WAL_CKPT_LOCK);
+
+      if( rc==SQLITE_OK ){
+        /* Check that the wal file has not been wrapped. Assuming that it has
+        ** not, also check that no checkpointer has attempted to checkpoint any
+        ** frames beyond pSnapshot->mxFrame. If either of these conditions are
+        ** true, return SQLITE_BUSY_SNAPSHOT. Otherwise, overwrite pWal->hdr
+        ** with *pSnapshot and set *pChanged as appropriate for opening the
+        ** snapshot.  */
+        if( !memcmp(pSnapshot->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))
+         && pSnapshot->mxFrame>=pInfo->nBackfillAttempted
+        ){
+          assert( pWal->readLock>0 );
+          memcpy(&pWal->hdr, pSnapshot, sizeof(WalIndexHdr));
+          *pChanged = bChanged;
+        }else{
+          rc = SQLITE_BUSY_SNAPSHOT;
+        }
+
+        /* Release the shared CKPT lock obtained above. */
+        walUnlockShared(pWal, WAL_CKPT_LOCK);
+      }
+
+
+      if( rc!=SQLITE_OK ){
+        sqlite3WalEndReadTransaction(pWal);
+      }
+    }
+  }
+#endif
   return rc;
 }
 
@@ -46425,23 +56157,22 @@ SQLITE_PRIVATE void sqlite3WalEndReadTransaction(Wal *pWal){
 }
 
 /*
-** Read a page from the WAL, if it is present in the WAL and if the 
-** current read transaction is configured to use the WAL.  
+** Search the wal file for page pgno. If found, set *piRead to the frame that
+** contains the page. Otherwise, if pgno is not in the wal file, set *piRead
+** to zero.
 **
-** The *pInWal is set to 1 if the requested page is in the WAL and
-** has been loaded.  Or *pInWal is set to 0 if the page was not in 
-** the WAL and needs to be read out of the database.
+** Return SQLITE_OK if successful, or an error code if an error occurs. If an
+** error does occur, the final value of *piRead is undefined.
 */
-SQLITE_PRIVATE int sqlite3WalRead(
+SQLITE_PRIVATE int sqlite3WalFindFrame(
   Wal *pWal,                      /* WAL handle */
   Pgno pgno,                      /* Database page number to read data for */
-  int *pInWal,                    /* OUT: True if data is read from WAL */
-  int nOut,                       /* Size of buffer pOut in bytes */
-  u8 *pOut                        /* Buffer to write page data to */
+  u32 *piRead                     /* OUT: Frame number (or zero) */
 ){
   u32 iRead = 0;                  /* If !=0, WAL frame to return data from */
   u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */
   int iHash;                      /* Used to loop through N hash tables */
+  int iMinHash;
 
   /* This routine is only be called from within a read transaction. */
   assert( pWal->readLock>=0 || pWal->lockError );
@@ -46453,7 +56184,7 @@ SQLITE_PRIVATE int sqlite3WalRead(
   ** WAL were empty.
   */
   if( iLast==0 || pWal->readLock==0 ){
-    *pInWal = 0;
+    *piRead = 0;
     return SQLITE_OK;
   }
 
@@ -46482,7 +56213,8 @@ SQLITE_PRIVATE int sqlite3WalRead(
   **     This condition filters out entries that were added to the hash
   **     table after the current read-transaction had started.
   */
-  for(iHash=walFramePage(iLast); iHash>=0 && iRead==0; iHash--){
+  iMinHash = walFramePage(pWal->minFrame);
+  for(iHash=walFramePage(iLast); iHash>=iMinHash && iRead==0; iHash--){
     volatile ht_slot *aHash;      /* Pointer to hash table */
     volatile u32 *aPgno;          /* Pointer to array of page numbers */
     u32 iZero;                    /* Frame number corresponding to aPgno[0] */
@@ -46497,8 +56229,8 @@ SQLITE_PRIVATE int sqlite3WalRead(
     nCollide = HASHTABLE_NSLOT;
     for(iKey=walHash(pgno); aHash[iKey]; iKey=walNextHash(iKey)){
       u32 iFrame = aHash[iKey] + iZero;
-      if( iFrame<=iLast && aPgno[aHash[iKey]]==pgno ){
-        assert( iFrame>iRead );
+      if( iFrame<=iLast && iFrame>=pWal->minFrame && aPgno[aHash[iKey]]==pgno ){
+        assert( iFrame>iRead || CORRUPT_DB );
         iRead = iFrame;
       }
       if( (nCollide--)==0 ){
@@ -46514,7 +56246,8 @@ SQLITE_PRIVATE int sqlite3WalRead(
   {
     u32 iRead2 = 0;
     u32 iTest;
-    for(iTest=iLast; iTest>0; iTest--){
+    assert( pWal->minFrame>0 );
+    for(iTest=iLast; iTest>=pWal->minFrame; iTest--){
       if( walFramePgno(pWal, iTest)==pgno ){
         iRead2 = iTest;
         break;
@@ -46524,26 +56257,31 @@ SQLITE_PRIVATE int sqlite3WalRead(
   }
 #endif
 
-  /* If iRead is non-zero, then it is the log frame number that contains the
-  ** required page. Read and return data from the log file.
-  */
-  if( iRead ){
-    int sz;
-    i64 iOffset;
-    sz = pWal->hdr.szPage;
-    sz = (sz&0xfe00) + ((sz&0x0001)<<16);
-    testcase( sz<=32768 );
-    testcase( sz>=65536 );
-    iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
-    *pInWal = 1;
-    /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
-    return sqlite3OsRead(pWal->pWalFd, pOut, nOut, iOffset);
-  }
-
-  *pInWal = 0;
+  *piRead = iRead;
   return SQLITE_OK;
 }
 
+/*
+** Read the contents of frame iRead from the wal file into buffer pOut
+** (which is nOut bytes in size). Return SQLITE_OK if successful, or an
+** error code otherwise.
+*/
+SQLITE_PRIVATE int sqlite3WalReadFrame(
+  Wal *pWal,                      /* WAL handle */
+  u32 iRead,                      /* Frame to read */
+  int nOut,                       /* Size of buffer pOut in bytes */
+  u8 *pOut                        /* Buffer to write page data to */
+){
+  int sz;
+  i64 iOffset;
+  sz = pWal->hdr.szPage;
+  sz = (sz&0xfe00) + ((sz&0x0001)<<16);
+  testcase( sz<=32768 );
+  testcase( sz>=65536 );
+  iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;
+  /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
+  return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
+}
 
 /* 
 ** Return the size of the database in pages (or zero, if unknown).
@@ -46575,6 +56313,7 @@ SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal){
   /* Cannot start a write transaction without first holding a read
   ** transaction. */
   assert( pWal->readLock>=0 );
+  assert( pWal->writeLock==0 && pWal->iReCksum==0 );
 
   if( pWal->readOnly ){
     return SQLITE_READONLY;
@@ -46596,7 +56335,7 @@ SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal){
   if( memcmp(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr))!=0 ){
     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
     pWal->writeLock = 0;
-    rc = SQLITE_BUSY;
+    rc = SQLITE_BUSY_SNAPSHOT;
   }
 
   return rc;
@@ -46610,6 +56349,8 @@ SQLITE_PRIVATE int sqlite3WalEndWriteTransaction(Wal *pWal){
   if( pWal->writeLock ){
     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
     pWal->writeLock = 0;
+    pWal->iReCksum = 0;
+    pWal->truncateOnCommit = 0;
   }
   return SQLITE_OK;
 }
@@ -46655,9 +56396,8 @@ SQLITE_PRIVATE int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *p
       assert( walFramePgno(pWal, iFrame)!=1 );
       rc = xUndo(pUndoCtx, walFramePgno(pWal, iFrame));
     }
-    walCleanupHash(pWal);
+    if( iMax!=pWal->hdr.mxFrame ) walCleanupHash(pWal);
   }
-  assert( rc==SQLITE_OK );
   return rc;
 }
 
@@ -46738,36 +56478,8 @@ static int walRestartLog(Wal *pWal){
         ** In theory it would be Ok to update the cache of the header only
         ** at this point. But updating the actual wal-index header is also
         ** safe and means there is no special case for sqlite3WalUndo()
-        ** to handle if this transaction is rolled back.
-        */
-        int i;                    /* Loop counter */
-        u32 *aSalt = pWal->hdr.aSalt;       /* Big-endian salt values */
-
-        /* Limit the size of WAL file if the journal_size_limit PRAGMA is
-        ** set to a non-negative value.  Log errors encountered
-        ** during the truncation attempt. */
-        if( pWal->mxWalSize>=0 ){
-          i64 sz;
-          int rx;
-          sqlite3BeginBenignMalloc();
-          rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
-          if( rx==SQLITE_OK && (sz > pWal->mxWalSize) ){
-            rx = sqlite3OsTruncate(pWal->pWalFd, pWal->mxWalSize);
-          }
-          sqlite3EndBenignMalloc();
-          if( rx ){
-            sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
-          }
-        }
-
-        pWal->nCkpt++;
-        pWal->hdr.mxFrame = 0;
-        sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));
-        aSalt[1] = salt1;
-        walIndexWriteHdr(pWal);
-        pInfo->nBackfill = 0;
-        for(i=1; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;
-        assert( pInfo->aReadMark[0]==0 );
+        ** to handle if this transaction is rolled back.  */
+        walRestartHdr(pWal, salt1);
         walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
       }else if( rc!=SQLITE_BUSY ){
         return rc;
@@ -46788,6 +56500,127 @@ static int walRestartLog(Wal *pWal){
   return rc;
 }
 
+/*
+** Information about the current state of the WAL file and where
+** the next fsync should occur - passed from sqlite3WalFrames() into
+** walWriteToLog().
+*/
+typedef struct WalWriter {
+  Wal *pWal;                   /* The complete WAL information */
+  sqlite3_file *pFd;           /* The WAL file to which we write */
+  sqlite3_int64 iSyncPoint;    /* Fsync at this offset */
+  int syncFlags;               /* Flags for the fsync */
+  int szPage;                  /* Size of one page */
+} WalWriter;
+
+/*
+** Write iAmt bytes of content into the WAL file beginning at iOffset.
+** Do a sync when crossing the p->iSyncPoint boundary.
+**
+** In other words, if iSyncPoint is in between iOffset and iOffset+iAmt,
+** first write the part before iSyncPoint, then sync, then write the
+** rest.
+*/
+static int walWriteToLog(
+  WalWriter *p,              /* WAL to write to */
+  void *pContent,            /* Content to be written */
+  int iAmt,                  /* Number of bytes to write */
+  sqlite3_int64 iOffset      /* Start writing at this offset */
+){
+  int rc;
+  if( iOffset<p->iSyncPoint && iOffset+iAmt>=p->iSyncPoint ){
+    int iFirstAmt = (int)(p->iSyncPoint - iOffset);
+    rc = sqlite3OsWrite(p->pFd, pContent, iFirstAmt, iOffset);
+    if( rc ) return rc;
+    iOffset += iFirstAmt;
+    iAmt -= iFirstAmt;
+    pContent = (void*)(iFirstAmt + (char*)pContent);
+    assert( p->syncFlags & (SQLITE_SYNC_NORMAL|SQLITE_SYNC_FULL) );
+    rc = sqlite3OsSync(p->pFd, p->syncFlags & SQLITE_SYNC_MASK);
+    if( iAmt==0 || rc ) return rc;
+  }
+  rc = sqlite3OsWrite(p->pFd, pContent, iAmt, iOffset);
+  return rc;
+}
+
+/*
+** Write out a single frame of the WAL
+*/
+static int walWriteOneFrame(
+  WalWriter *p,               /* Where to write the frame */
+  PgHdr *pPage,               /* The page of the frame to be written */
+  int nTruncate,              /* The commit flag.  Usually 0.  >0 for commit */
+  sqlite3_int64 iOffset       /* Byte offset at which to write */
+){
+  int rc;                         /* Result code from subfunctions */
+  void *pData;                    /* Data actually written */
+  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
+#if defined(SQLITE_HAS_CODEC)
+  if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM_BKPT;
+#else
+  pData = pPage->pData;
+#endif
+  walEncodeFrame(p->pWal, pPage->pgno, nTruncate, pData, aFrame);
+  rc = walWriteToLog(p, aFrame, sizeof(aFrame), iOffset);
+  if( rc ) return rc;
+  /* Write the page data */
+  rc = walWriteToLog(p, pData, p->szPage, iOffset+sizeof(aFrame));
+  return rc;
+}
+
+/*
+** This function is called as part of committing a transaction within which
+** one or more frames have been overwritten. It updates the checksums for
+** all frames written to the wal file by the current transaction starting
+** with the earliest to have been overwritten.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+static int walRewriteChecksums(Wal *pWal, u32 iLast){
+  const int szPage = pWal->szPage;/* Database page size */
+  int rc = SQLITE_OK;             /* Return code */
+  u8 *aBuf;                       /* Buffer to load data from wal file into */
+  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-headers in */
+  u32 iRead;                      /* Next frame to read from wal file */
+  i64 iCksumOff;
+
+  aBuf = sqlite3_malloc(szPage + WAL_FRAME_HDRSIZE);
+  if( aBuf==0 ) return SQLITE_NOMEM_BKPT;
+
+  /* Find the checksum values to use as input for the recalculating the
+  ** first checksum. If the first frame is frame 1 (implying that the current
+  ** transaction restarted the wal file), these values must be read from the
+  ** wal-file header. Otherwise, read them from the frame header of the
+  ** previous frame.  */
+  assert( pWal->iReCksum>0 );
+  if( pWal->iReCksum==1 ){
+    iCksumOff = 24;
+  }else{
+    iCksumOff = walFrameOffset(pWal->iReCksum-1, szPage) + 16;
+  }
+  rc = sqlite3OsRead(pWal->pWalFd, aBuf, sizeof(u32)*2, iCksumOff);
+  pWal->hdr.aFrameCksum[0] = sqlite3Get4byte(aBuf);
+  pWal->hdr.aFrameCksum[1] = sqlite3Get4byte(&aBuf[sizeof(u32)]);
+
+  iRead = pWal->iReCksum;
+  pWal->iReCksum = 0;
+  for(; rc==SQLITE_OK && iRead<=iLast; iRead++){
+    i64 iOff = walFrameOffset(iRead, szPage);
+    rc = sqlite3OsRead(pWal->pWalFd, aBuf, szPage+WAL_FRAME_HDRSIZE, iOff);
+    if( rc==SQLITE_OK ){
+      u32 iPgno, nDbSize;
+      iPgno = sqlite3Get4byte(aBuf);
+      nDbSize = sqlite3Get4byte(&aBuf[4]);
+
+      walEncodeFrame(pWal, iPgno, nDbSize, &aBuf[WAL_FRAME_HDRSIZE], aFrame);
+      rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOff);
+    }
+  }
+
+  sqlite3_free(aBuf);
+  return rc;
+}
+
 /* 
 ** Write a set of frames to the log. The caller must hold the write-lock
 ** on the log file (obtained using sqlite3WalBeginWriteTransaction()).
@@ -46802,14 +56635,22 @@ SQLITE_PRIVATE int sqlite3WalFrames(
 ){
   int rc;                         /* Used to catch return codes */
   u32 iFrame;                     /* Next frame address */
-  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
   PgHdr *p;                       /* Iterator to run through pList with. */
   PgHdr *pLast = 0;               /* Last frame in list */
-  int nLast = 0;                  /* Number of extra copies of last page */
+  int nExtra = 0;                 /* Number of extra copies of last page */
+  int szFrame;                    /* The size of a single frame */
+  i64 iOffset;                    /* Next byte to write in WAL file */
+  WalWriter w;                    /* The writer */
+  u32 iFirst = 0;                 /* First frame that may be overwritten */
+  WalIndexHdr *pLive;             /* Pointer to shared header */
 
   assert( pList );
   assert( pWal->writeLock );
 
+  /* If this frame set completes a transaction, then nTruncate>0.  If
+  ** nTruncate==0 then this frame set does not complete the transaction. */
+  assert( (isCommit!=0)==(nTruncate!=0) );
+
 #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
   { int cnt; for(cnt=0, p=pList; p; p=p->pDirty, cnt++){}
     WALTRACE(("WAL%p: frame write begin. %d frames. mxFrame=%d. %s\n",
@@ -46817,6 +56658,11 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   }
 #endif
 
+  pLive = (WalIndexHdr*)walIndexHdr(pWal);
+  if( memcmp(&pWal->hdr, (void *)pLive, sizeof(WalIndexHdr))!=0 ){
+    iFirst = pLive->mxFrame+1;
+  }
+
   /* See if it is possible to write these frames into the start of the
   ** log file, instead of appending to it at pWal->hdr.mxFrame.
   */
@@ -46837,7 +56683,7 @@ SQLITE_PRIVATE int sqlite3WalFrames(
     sqlite3Put4byte(&aWalHdr[4], WAL_MAX_VERSION);
     sqlite3Put4byte(&aWalHdr[8], szPage);
     sqlite3Put4byte(&aWalHdr[12], pWal->nCkpt);
-    sqlite3_randomness(8, pWal->hdr.aSalt);
+    if( pWal->nCkpt==0 ) sqlite3_randomness(8, pWal->hdr.aSalt);
     memcpy(&aWalHdr[16], pWal->hdr.aSalt, 8);
     walChecksumBytes(1, aWalHdr, WAL_HDRSIZE-2*4, 0, aCksum);
     sqlite3Put4byte(&aWalHdr[24], aCksum[0]);
@@ -46847,77 +56693,128 @@ SQLITE_PRIVATE int sqlite3WalFrames(
     pWal->hdr.bigEndCksum = SQLITE_BIGENDIAN;
     pWal->hdr.aFrameCksum[0] = aCksum[0];
     pWal->hdr.aFrameCksum[1] = aCksum[1];
+    pWal->truncateOnCommit = 1;
 
     rc = sqlite3OsWrite(pWal->pWalFd, aWalHdr, sizeof(aWalHdr), 0);
     WALTRACE(("WAL%p: wal-header write %s\n", pWal, rc ? "failed" : "ok"));
     if( rc!=SQLITE_OK ){
       return rc;
     }
+
+    /* Sync the header (unless SQLITE_IOCAP_SEQUENTIAL is true or unless
+    ** all syncing is turned off by PRAGMA synchronous=OFF).  Otherwise
+    ** an out-of-order write following a WAL restart could result in
+    ** database corruption.  See the ticket:
+    **
+    **     http://localhost:591/sqlite/info/ff5be73dee
+    */
+    if( pWal->syncHeader && sync_flags ){
+      rc = sqlite3OsSync(pWal->pWalFd, sync_flags & SQLITE_SYNC_MASK);
+      if( rc ) return rc;
+    }
   }
   assert( (int)pWal->szPage==szPage );
 
-  /* Write the log file. */
+  /* Setup information needed to write frames into the WAL */
+  w.pWal = pWal;
+  w.pFd = pWal->pWalFd;
+  w.iSyncPoint = 0;
+  w.syncFlags = sync_flags;
+  w.szPage = szPage;
+  iOffset = walFrameOffset(iFrame+1, szPage);
+  szFrame = szPage + WAL_FRAME_HDRSIZE;
+
+  /* Write all frames into the log file exactly once */
   for(p=pList; p; p=p->pDirty){
-    u32 nDbsize;                  /* Db-size field for frame header */
-    i64 iOffset;                  /* Write offset in log file */
-    void *pData;
-   
-    iOffset = walFrameOffset(++iFrame, szPage);
-    /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
-    
-    /* Populate and write the frame header */
-    nDbsize = (isCommit && p->pDirty==0) ? nTruncate : 0;
+    int nDbSize;   /* 0 normally.  Positive == commit flag */
+
+    /* Check if this page has already been written into the wal file by
+    ** the current transaction. If so, overwrite the existing frame and
+    ** set Wal.writeLock to WAL_WRITELOCK_RECKSUM - indicating that 
+    ** checksums must be recomputed when the transaction is committed.  */
+    if( iFirst && (p->pDirty || isCommit==0) ){
+      u32 iWrite = 0;
+      VVA_ONLY(rc =) sqlite3WalFindFrame(pWal, p->pgno, &iWrite);
+      assert( rc==SQLITE_OK || iWrite==0 );
+      if( iWrite>=iFirst ){
+        i64 iOff = walFrameOffset(iWrite, szPage) + WAL_FRAME_HDRSIZE;
+        void *pData;
+        if( pWal->iReCksum==0 || iWrite<pWal->iReCksum ){
+          pWal->iReCksum = iWrite;
+        }
 #if defined(SQLITE_HAS_CODEC)
-    if( (pData = sqlite3PagerCodec(p))==0 ) return SQLITE_NOMEM;
+        if( (pData = sqlite3PagerCodec(p))==0 ) return SQLITE_NOMEM;
 #else
-    pData = p->pData;
+        pData = p->pData;
 #endif
-    walEncodeFrame(pWal, p->pgno, nDbsize, pData, aFrame);
-    rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOffset);
-    if( rc!=SQLITE_OK ){
-      return rc;
+        rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOff);
+        if( rc ) return rc;
+        p->flags &= ~PGHDR_WAL_APPEND;
+        continue;
+      }
     }
 
-    /* Write the page data */
-    rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOffset+sizeof(aFrame));
-    if( rc!=SQLITE_OK ){
-      return rc;
-    }
+    iFrame++;
+    assert( iOffset==walFrameOffset(iFrame, szPage) );
+    nDbSize = (isCommit && p->pDirty==0) ? nTruncate : 0;
+    rc = walWriteOneFrame(&w, p, nDbSize, iOffset);
+    if( rc ) return rc;
     pLast = p;
+    iOffset += szFrame;
+    p->flags |= PGHDR_WAL_APPEND;
   }
 
-  /* Sync the log file if the 'isSync' flag was specified. */
-  if( sync_flags ){
-    i64 iSegment = sqlite3OsSectorSize(pWal->pWalFd);
-    i64 iOffset = walFrameOffset(iFrame+1, szPage);
-
-    assert( isCommit );
-    assert( iSegment>0 );
+  /* Recalculate checksums within the wal file if required. */
+  if( isCommit && pWal->iReCksum ){
+    rc = walRewriteChecksums(pWal, iFrame);
+    if( rc ) return rc;
+  }
 
-    iSegment = (((iOffset+iSegment-1)/iSegment) * iSegment);
-    while( iOffset<iSegment ){
-      void *pData;
-#if defined(SQLITE_HAS_CODEC)
-      if( (pData = sqlite3PagerCodec(pLast))==0 ) return SQLITE_NOMEM;
-#else
-      pData = pLast->pData;
-#endif
-      walEncodeFrame(pWal, pLast->pgno, nTruncate, pData, aFrame);
-      /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */
-      rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOffset);
-      if( rc!=SQLITE_OK ){
-        return rc;
-      }
-      iOffset += WAL_FRAME_HDRSIZE;
-      rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOffset); 
-      if( rc!=SQLITE_OK ){
-        return rc;
+  /* If this is the end of a transaction, then we might need to pad
+  ** the transaction and/or sync the WAL file.
+  **
+  ** Padding and syncing only occur if this set of frames complete a
+  ** transaction and if PRAGMA synchronous=FULL.  If synchronous==NORMAL
+  ** or synchronous==OFF, then no padding or syncing are needed.
+  **
+  ** If SQLITE_IOCAP_POWERSAFE_OVERWRITE is defined, then padding is not
+  ** needed and only the sync is done.  If padding is needed, then the
+  ** final frame is repeated (with its commit mark) until the next sector
+  ** boundary is crossed.  Only the part of the WAL prior to the last
+  ** sector boundary is synced; the part of the last frame that extends
+  ** past the sector boundary is written after the sync.
+  */
+  if( isCommit && (sync_flags & WAL_SYNC_TRANSACTIONS)!=0 ){
+    int bSync = 1;
+    if( pWal->padToSectorBoundary ){
+      int sectorSize = sqlite3SectorSize(pWal->pWalFd);
+      w.iSyncPoint = ((iOffset+sectorSize-1)/sectorSize)*sectorSize;
+      bSync = (w.iSyncPoint==iOffset);
+      testcase( bSync );
+      while( iOffset<w.iSyncPoint ){
+        rc = walWriteOneFrame(&w, pLast, nTruncate, iOffset);
+        if( rc ) return rc;
+        iOffset += szFrame;
+        nExtra++;
       }
-      nLast++;
-      iOffset += szPage;
     }
+    if( bSync ){
+      assert( rc==SQLITE_OK );
+      rc = sqlite3OsSync(w.pFd, sync_flags & SQLITE_SYNC_MASK);
+    }
+  }
 
-    rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
+  /* If this frame set completes the first transaction in the WAL and
+  ** if PRAGMA journal_size_limit is set, then truncate the WAL to the
+  ** journal size limit, if possible.
+  */
+  if( isCommit && pWal->truncateOnCommit && pWal->mxWalSize>=0 ){
+    i64 sz = pWal->mxWalSize;
+    if( walFrameOffset(iFrame+nExtra+1, szPage)>pWal->mxWalSize ){
+      sz = walFrameOffset(iFrame+nExtra+1, szPage);
+    }
+    walLimitSize(pWal, sz);
+    pWal->truncateOnCommit = 0;
   }
 
   /* Append data to the wal-index. It is not necessary to lock the 
@@ -46927,12 +56824,13 @@ SQLITE_PRIVATE int sqlite3WalFrames(
   */
   iFrame = pWal->hdr.mxFrame;
   for(p=pList; p && rc==SQLITE_OK; p=p->pDirty){
+    if( (p->flags & PGHDR_WAL_APPEND)==0 ) continue;
     iFrame++;
     rc = walIndexAppend(pWal, iFrame, p->pgno);
   }
-  while( nLast>0 && rc==SQLITE_OK ){
+  while( rc==SQLITE_OK && nExtra>0 ){
     iFrame++;
-    nLast--;
+    nExtra--;
     rc = walIndexAppend(pWal, iFrame, pLast->pgno);
   }
 
@@ -46969,7 +56867,7 @@ SQLITE_PRIVATE int sqlite3WalFrames(
 */
 SQLITE_PRIVATE int sqlite3WalCheckpoint(
   Wal *pWal,                      /* Wal connection */
-  int eMode,                      /* PASSIVE, FULL or RESTART */
+  int eMode,                      /* PASSIVE, FULL, RESTART, or TRUNCATE */
   int (*xBusy)(void*),            /* Function to call when busy */
   void *pBusyArg,                 /* Context argument for xBusyHandler */
   int sync_flags,                 /* Flags to sync db file with (or 0) */
@@ -46981,29 +56879,42 @@ SQLITE_PRIVATE int sqlite3WalCheckpoint(
   int rc;                         /* Return code */
   int isChanged = 0;              /* True if a new wal-index header is loaded */
   int eMode2 = eMode;             /* Mode to pass to walCheckpoint() */
+  int (*xBusy2)(void*) = xBusy;   /* Busy handler for eMode2 */
 
   assert( pWal->ckptLock==0 );
   assert( pWal->writeLock==0 );
 
+  /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
+  ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
+  assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );
+
   if( pWal->readOnly ) return SQLITE_READONLY;
   WALTRACE(("WAL%p: checkpoint begins\n", pWal));
+
+  /* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive 
+  ** "checkpoint" lock on the database file. */
   rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
   if( rc ){
-    /* Usually this is SQLITE_BUSY meaning that another thread or process
-    ** is already running a checkpoint, or maybe a recovery.  But it might
-    ** also be SQLITE_IOERR. */
+    /* EVIDENCE-OF: R-10421-19736 If any other process is running a
+    ** checkpoint operation at the same time, the lock cannot be obtained and
+    ** SQLITE_BUSY is returned.
+    ** EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured,
+    ** it will not be invoked in this case.
+    */
+    testcase( rc==SQLITE_BUSY );
+    testcase( xBusy!=0 );
     return rc;
   }
   pWal->ckptLock = 1;
 
-  /* If this is a blocking-checkpoint, then obtain the write-lock as well
-  ** to prevent any writers from running while the checkpoint is underway.
-  ** This has to be done before the call to walIndexReadHdr() below.
+  /* IMPLEMENTATION-OF: R-59782-36818 The SQLITE_CHECKPOINT_FULL, RESTART and
+  ** TRUNCATE modes also obtain the exclusive "writer" lock on the database
+  ** file.
   **
-  ** If the writer lock cannot be obtained, then a passive checkpoint is
-  ** run instead. Since the checkpointer is not holding the writer lock,
-  ** there is no point in blocking waiting for any readers. Assuming no 
-  ** other error occurs, this function will return SQLITE_BUSY to the caller.
+  ** EVIDENCE-OF: R-60642-04082 If the writer lock cannot be obtained
+  ** immediately, and a busy-handler is configured, it is invoked and the
+  ** writer lock retried until either the busy-handler returns 0 or the
+  ** lock is successfully obtained.
   */
   if( eMode!=SQLITE_CHECKPOINT_PASSIVE ){
     rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_WRITE_LOCK, 1);
@@ -47011,6 +56922,7 @@ SQLITE_PRIVATE int sqlite3WalCheckpoint(
       pWal->writeLock = 1;
     }else if( rc==SQLITE_BUSY ){
       eMode2 = SQLITE_CHECKPOINT_PASSIVE;
+      xBusy2 = 0;
       rc = SQLITE_OK;
     }
   }
@@ -47018,14 +56930,18 @@ SQLITE_PRIVATE int sqlite3WalCheckpoint(
   /* Read the wal-index header. */
   if( rc==SQLITE_OK ){
     rc = walIndexReadHdr(pWal, &isChanged);
+    if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){
+      sqlite3OsUnfetch(pWal->pDbFd, 0, 0);
+    }
   }
 
   /* Copy data from the log to the database file. */
   if( rc==SQLITE_OK ){
+
     if( pWal->hdr.mxFrame && walPagesize(pWal)!=nBuf ){
       rc = SQLITE_CORRUPT_BKPT;
     }else{
-      rc = walCheckpoint(pWal, eMode2, xBusy, pBusyArg, sync_flags, zBuf);
+      rc = walCheckpoint(pWal, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);
     }
 
     /* If no error occurred, set the output variables. */
@@ -47137,6 +57053,70 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
   return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );
 }
 
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/* Create a snapshot object.  The content of a snapshot is opaque to
+** every other subsystem, so the WAL module can put whatever it needs
+** in the object.
+*/
+SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot){
+  int rc = SQLITE_OK;
+  WalIndexHdr *pRet;
+
+  assert( pWal->readLock>=0 && pWal->writeLock==0 );
+
+  pRet = (WalIndexHdr*)sqlite3_malloc(sizeof(WalIndexHdr));
+  if( pRet==0 ){
+    rc = SQLITE_NOMEM_BKPT;
+  }else{
+    memcpy(pRet, &pWal->hdr, sizeof(WalIndexHdr));
+    *ppSnapshot = (sqlite3_snapshot*)pRet;
+  }
+
+  return rc;
+}
+
+/* Try to open on pSnapshot when the next read-transaction starts
+*/
+SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot){
+  pWal->pSnapshot = (WalIndexHdr*)pSnapshot;
+}
+
+/* 
+** Return a +ve value if snapshot p1 is newer than p2. A -ve value if
+** p1 is older than p2 and zero if p1 and p2 are the same snapshot.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_snapshot_cmp(sqlite3_snapshot *p1, sqlite3_snapshot *p2){
+  WalIndexHdr *pHdr1 = (WalIndexHdr*)p1;
+  WalIndexHdr *pHdr2 = (WalIndexHdr*)p2;
+
+  /* aSalt[0] is a copy of the value stored in the wal file header. It
+  ** is incremented each time the wal file is restarted.  */
+  if( pHdr1->aSalt[0]<pHdr2->aSalt[0] ) return -1;
+  if( pHdr1->aSalt[0]>pHdr2->aSalt[0] ) return +1;
+  if( pHdr1->mxFrame<pHdr2->mxFrame ) return -1;
+  if( pHdr1->mxFrame>pHdr2->mxFrame ) return +1;
+  return 0;
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
+
+#ifdef SQLITE_ENABLE_ZIPVFS
+/*
+** If the argument is not NULL, it points to a Wal object that holds a
+** read-lock. This function returns the database page-size if it is known,
+** or zero if it is not (or if pWal is NULL).
+*/
+SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal){
+  assert( pWal==0 || pWal->readLock>=0 );
+  return (pWal ? pWal->szPage : 0);
+}
+#endif
+
+/* Return the sqlite3_file object for the WAL file
+*/
+SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal){
+  return pWal->pWalFd;
+}
+
 #endif /* #ifndef SQLITE_OMIT_WAL */
 
 /************** End of wal.c *************************************************/
@@ -47171,7 +57151,7 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file implements a external (disk-based) database using BTrees.
+** This file implements an external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
 **
 **     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
@@ -47218,13 +57198,13 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 **
 **   OFFSET   SIZE    DESCRIPTION
 **      0      16     Header string: "SQLite format 3\000"
-**     16       2     Page size in bytes.  
+**     16       2     Page size in bytes.  (1 means 65536)
 **     18       1     File format write version
 **     19       1     File format read version
 **     20       1     Bytes of unused space at the end of each page
-**     21       1     Max embedded payload fraction
-**     22       1     Min embedded payload fraction
-**     23       1     Min leaf payload fraction
+**     21       1     Max embedded payload fraction (must be 64)
+**     22       1     Min embedded payload fraction (must be 32)
+**     23       1     Min leaf payload fraction (must be 32)
 **     24       4     File change counter
 **     28       4     Reserved for future use
 **     32       4     First freelist page
@@ -47238,9 +57218,10 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 **     56       4     1=UTF-8 2=UTF16le 3=UTF16be
 **     60       4     User version
 **     64       4     Incremental vacuum mode
-**     68       4     unused
-**     72       4     unused
-**     76       4     unused
+**     68       4     Application-ID
+**     72      20     unused
+**     92       4     The version-valid-for number
+**     96       4     SQLITE_VERSION_NUMBER
 **
 ** All of the integer values are big-endian (most significant byte first).
 **
@@ -47296,7 +57277,7 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 **
 ** The flags define the format of this btree page.  The leaf flag means that
 ** this page has no children.  The zerodata flag means that this page carries
-** only keys and no data.  The intkey flag means that the key is a integer
+** only keys and no data.  The intkey flag means that the key is an integer
 ** which is stored in the key size entry of the cell header rather than in
 ** the payload area.
 **
@@ -47374,6 +57355,7 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 **      4     Number of leaf pointers on this page
 **      *     zero or more pages numbers of leaves
 */
+/* #include "sqliteInt.h" */
 
 
 /* The following value is the maximum cell size assuming a maximum page
@@ -47391,6 +57373,7 @@ SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){
 /* Forward declarations */
 typedef struct MemPage MemPage;
 typedef struct BtLock BtLock;
+typedef struct CellInfo CellInfo;
 
 /*
 ** This is a magic string that appears at the beginning of every
@@ -47433,24 +57416,30 @@ typedef struct BtLock BtLock;
 struct MemPage {
   u8 isInit;           /* True if previously initialized. MUST BE FIRST! */
   u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */
-  u8 intKey;           /* True if intkey flag is set */
-  u8 leaf;             /* True if leaf flag is set */
-  u8 hasData;          /* True if this page stores data */
+  u8 intKey;           /* True if table b-trees.  False for index b-trees */
+  u8 intKeyLeaf;       /* True if the leaf of an intKey table */
+  u8 leaf;             /* True if a leaf page */
   u8 hdrOffset;        /* 100 for page 1.  0 otherwise */
   u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */
+  u8 max1bytePayload;  /* min(maxLocal,127) */
+  u8 bBusy;            /* Prevent endless loops on corrupt database files */
   u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */
   u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */
   u16 cellOffset;      /* Index in aData of first cell pointer */
   u16 nFree;           /* Number of free bytes on the page */
   u16 nCell;           /* Number of cells on this page, local and ovfl */
   u16 maskPage;        /* Mask for page offset */
-  struct _OvflCell {   /* Cells that will not fit on aData[] */
-    u8 *pCell;          /* Pointers to the body of the overflow cell */
-    u16 idx;            /* Insert this cell before idx-th non-overflow cell */
-  } aOvfl[5];
+  u16 aiOvfl[5];       /* Insert the i-th overflow cell before the aiOvfl-th
+                       ** non-overflow cell */
+  u8 *apOvfl[5];       /* Pointers to the body of overflow cells */
   BtShared *pBt;       /* Pointer to BtShared that this page is part of */
   u8 *aData;           /* Pointer to disk image of the page data */
+  u8 *aDataEnd;        /* One byte past the end of usable data */
+  u8 *aCellIdx;        /* The cell index area */
+  u8 *aDataOfst;       /* Same as aData for leaves.  aData+4 for interior */
   DbPage *pDbPage;     /* Pager page handle */
+  u16 (*xCellSize)(MemPage*,u8*);             /* cellSizePtr method */
+  void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */
   Pgno pgno;           /* Page number for this page */
 };
 
@@ -47506,8 +57495,10 @@ struct Btree {
   u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
   u8 sharable;       /* True if we can share pBt with another db */
   u8 locked;         /* True if db currently has pBt locked */
+  u8 hasIncrblobCur; /* True if there are one or more Incrblob cursors */
   int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */
   int nBackup;       /* Number of backup operations reading this btree */
+  u32 iDataVersion;  /* Combines with pBt->pPager->iDataVersion */
   Btree *pNext;      /* List of other sharable Btrees from the same db */
   Btree *pPrev;      /* Back pointer of the same list */
 #ifndef SQLITE_OMIT_SHARED_CACHE
@@ -47529,7 +57520,7 @@ struct Btree {
 /*
 ** An instance of this object represents a single database file.
 ** 
-** A single database file can be in use as the same time by two
+** A single database file can be in use at the same time by two
 ** or more database connections.  When two or more connections are
 ** sharing the same database file, each connection has it own
 ** private Btree object for the file and each of those Btrees points
@@ -47566,17 +57557,18 @@ struct BtShared {
   sqlite3 *db;          /* Database connection currently using this Btree */
   BtCursor *pCursor;    /* A list of all open cursors */
   MemPage *pPage1;      /* First page of the database */
-  u8 readOnly;          /* True if the underlying file is readonly */
-  u8 pageSizeFixed;     /* True if the page size can no longer be changed */
-  u8 secureDelete;      /* True if secure_delete is enabled */
-  u8 initiallyEmpty;    /* Database is empty at start of transaction */
   u8 openFlags;         /* Flags to sqlite3BtreeOpen() */
 #ifndef SQLITE_OMIT_AUTOVACUUM
   u8 autoVacuum;        /* True if auto-vacuum is enabled */
   u8 incrVacuum;        /* True if incr-vacuum is enabled */
+  u8 bDoTruncate;       /* True to truncate db on commit */
 #endif
   u8 inTransaction;     /* Transaction state */
-  u8 doNotUseWAL;       /* If true, do not open write-ahead-log file */
+  u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
+#ifdef SQLITE_HAS_CODEC
+  u8 optimalReserve;    /* Desired amount of reserved space per page */
+#endif
+  u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
   u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
@@ -47594,26 +57586,31 @@ struct BtShared {
   BtShared *pNext;      /* Next on a list of sharable BtShared structs */
   BtLock *pLock;        /* List of locks held on this shared-btree struct */
   Btree *pWriter;       /* Btree with currently open write transaction */
-  u8 isExclusive;       /* True if pWriter has an EXCLUSIVE lock on the db */
-  u8 isPending;         /* If waiting for read-locks to clear */
 #endif
-  u8 *pTmpSpace;        /* BtShared.pageSize bytes of space for tmp use */
+  u8 *pTmpSpace;        /* Temp space sufficient to hold a single cell */
 };
 
 /*
+** Allowed values for BtShared.btsFlags
+*/
+#define BTS_READ_ONLY        0x0001   /* Underlying file is readonly */
+#define BTS_PAGESIZE_FIXED   0x0002   /* Page size can no longer be changed */
+#define BTS_SECURE_DELETE    0x0004   /* PRAGMA secure_delete is enabled */
+#define BTS_INITIALLY_EMPTY  0x0008   /* Database was empty at trans start */
+#define BTS_NO_WAL           0x0010   /* Do not open write-ahead-log files */
+#define BTS_EXCLUSIVE        0x0020   /* pWriter has an exclusive lock */
+#define BTS_PENDING          0x0040   /* Waiting for read-locks to clear */
+
+/*
 ** An instance of the following structure is used to hold information
 ** about a cell.  The parseCellPtr() function fills in this structure
 ** based on information extract from the raw disk page.
 */
-typedef struct CellInfo CellInfo;
 struct CellInfo {
-  i64 nKey;      /* The key for INTKEY tables, or number of bytes in key */
-  u8 *pCell;     /* Pointer to the start of cell content */
-  u32 nData;     /* Number of bytes of data */
-  u32 nPayload;  /* Total amount of payload */
-  u16 nHeader;   /* Size of the cell content header in bytes */
-  u16 nLocal;    /* Amount of payload held locally */
-  u16 iOverflow; /* Offset to overflow page number.  Zero if no overflow */
+  i64 nKey;      /* The key for INTKEY tables, or nPayload otherwise */
+  u8 *pPayload;  /* Pointer to the start of payload */
+  u32 nPayload;  /* Bytes of payload */
+  u16 nLocal;    /* Amount of payload held locally, not on overflow */
   u16 nSize;     /* Size of the cell content on the main b-tree page */
 };
 
@@ -47635,48 +57632,71 @@ struct CellInfo {
 ** The entry is identified by its MemPage and the index in
 ** MemPage.aCell[] of the entry.
 **
-** A single database file can shared by two more database connections,
+** A single database file can be shared by two more database connections,
 ** but cursors cannot be shared.  Each cursor is associated with a
 ** particular database connection identified BtCursor.pBtree.db.
 **
 ** Fields in this structure are accessed under the BtShared.mutex
 ** found at self->pBt->mutex. 
+**
+** skipNext meaning:
+**    eState==SKIPNEXT && skipNext>0:  Next sqlite3BtreeNext() is no-op.
+**    eState==SKIPNEXT && skipNext<0:  Next sqlite3BtreePrevious() is no-op.
+**    eState==FAULT:                   Cursor fault with skipNext as error code.
 */
 struct BtCursor {
   Btree *pBtree;            /* The Btree to which this cursor belongs */
   BtShared *pBt;            /* The BtShared this cursor points to */
-  BtCursor *pNext, *pPrev;  /* Forms a linked list of all cursors */
-  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
-  Pgno pgnoRoot;            /* The root page of this tree */
-  sqlite3_int64 cachedRowid; /* Next rowid cache.  0 means not valid */
+  BtCursor *pNext;          /* Forms a linked list of all cursors */
+  Pgno *aOverflow;          /* Cache of overflow page locations */
   CellInfo info;            /* A parse of the cell we are pointing at */
-  i64 nKey;        /* Size of pKey, or last integer key */
-  void *pKey;      /* Saved key that was cursor's last known position */
-  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive */
-  u8 wrFlag;                /* True if writable */
-  u8 atLast;                /* Cursor pointing to the last entry */
-  u8 validNKey;             /* True if info.nKey is valid */
+  i64 nKey;                 /* Size of pKey, or last integer key */
+  void *pKey;               /* Saved key that was cursor last known position */
+  Pgno pgnoRoot;            /* The root page of this tree */
+  int nOvflAlloc;           /* Allocated size of aOverflow[] array */
+  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.
+                   ** Error code if eState==CURSOR_FAULT */
+  u8 curFlags;              /* zero or more BTCF_* flags defined below */
+  u8 curPagerFlags;         /* Flags to send to sqlite3PagerGet() */
   u8 eState;                /* One of the CURSOR_XXX constants (see below) */
-#ifndef SQLITE_OMIT_INCRBLOB
-  Pgno *aOverflow;          /* Cache of overflow page locations */
-  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
-#endif
-  i16 iPage;                            /* Index of current page in apPage */
+  u8 hints;                 /* As configured by CursorSetHints() */
+  /* All fields above are zeroed when the cursor is allocated.  See
+  ** sqlite3BtreeCursorZero().  Fields that follow must be manually
+  ** initialized. */
+  i8 iPage;                 /* Index of current page in apPage */
+  u8 curIntKey;             /* Value of apPage[0]->intKey */
+  struct KeyInfo *pKeyInfo; /* Argument passed to comparison function */
+  void *padding1;           /* Make object size a multiple of 16 */
   u16 aiIdx[BTCURSOR_MAX_DEPTH];        /* Current index in apPage[i] */
   MemPage *apPage[BTCURSOR_MAX_DEPTH];  /* Pages from root to current page */
 };
 
 /*
+** Legal values for BtCursor.curFlags
+*/
+#define BTCF_WriteFlag    0x01   /* True if a write cursor */
+#define BTCF_ValidNKey    0x02   /* True if info.nKey is valid */
+#define BTCF_ValidOvfl    0x04   /* True if aOverflow is valid */
+#define BTCF_AtLast       0x08   /* Cursor is pointing ot the last entry */
+#define BTCF_Incrblob     0x10   /* True if an incremental I/O handle */
+#define BTCF_Multiple     0x20   /* Maybe another cursor on the same btree */
+
+/*
 ** Potential values for BtCursor.eState.
 **
-** CURSOR_VALID:
-**   Cursor points to a valid entry. getPayload() etc. may be called.
-**
 ** CURSOR_INVALID:
 **   Cursor does not point to a valid entry. This can happen (for example) 
 **   because the table is empty or because BtreeCursorFirst() has not been
 **   called.
 **
+** CURSOR_VALID:
+**   Cursor points to a valid entry. getPayload() etc. may be called.
+**
+** CURSOR_SKIPNEXT:
+**   Cursor is valid except that the Cursor.skipNext field is non-zero
+**   indicating that the next sqlite3BtreeNext() or sqlite3BtreePrevious()
+**   operation should be a no-op.
+**
 ** CURSOR_REQUIRESEEK:
 **   The table that this cursor was opened on still exists, but has been 
 **   modified since the cursor was last used. The cursor position is saved
@@ -47685,16 +57705,17 @@ struct BtCursor {
 **   seek the cursor to the saved position.
 **
 ** CURSOR_FAULT:
-**   A unrecoverable error (an I/O error or a malloc failure) has occurred
+**   An unrecoverable error (an I/O error or a malloc failure) has occurred
 **   on a different connection that shares the BtShared cache with this
 **   cursor.  The error has left the cache in an inconsistent state.
 **   Do nothing else with this cursor.  Any attempt to use the cursor
-**   should return the error code stored in BtCursor.skip
+**   should return the error code stored in BtCursor.skipNext
 */
 #define CURSOR_INVALID           0
 #define CURSOR_VALID             1
-#define CURSOR_REQUIRESEEK       2
-#define CURSOR_FAULT             3
+#define CURSOR_SKIPNEXT          2
+#define CURSOR_REQUIRESEEK       3
+#define CURSOR_FAULT             4
 
 /* 
 ** The database page the PENDING_BYTE occupies. This page is never used.
@@ -47782,27 +57803,53 @@ struct BtCursor {
 /*
 ** This structure is passed around through all the sanity checking routines
 ** in order to keep track of some global state information.
+**
+** The aRef[] array is allocated so that there is 1 bit for each page in
+** the database. As the integrity-check proceeds, for each page used in
+** the database the corresponding bit is set. This allows integrity-check to 
+** detect pages that are used twice and orphaned pages (both of which 
+** indicate corruption).
 */
 typedef struct IntegrityCk IntegrityCk;
 struct IntegrityCk {
   BtShared *pBt;    /* The tree being checked out */
   Pager *pPager;    /* The associated pager.  Also accessible by pBt->pPager */
+  u8 *aPgRef;       /* 1 bit per page in the db (see above) */
   Pgno nPage;       /* Number of pages in the database */
-  int *anRef;       /* Number of times each page is referenced */
   int mxErr;        /* Stop accumulating errors when this reaches zero */
   int nErr;         /* Number of messages written to zErrMsg so far */
   int mallocFailed; /* A memory allocation error has occurred */
+  const char *zPfx; /* Error message prefix */
+  int v1, v2;       /* Values for up to two %d fields in zPfx */
   StrAccum errMsg;  /* Accumulate the error message text here */
+  u32 *heap;        /* Min-heap used for analyzing cell coverage */
 };
 
 /*
-** Read or write a two- and four-byte big-endian integer values.
+** Routines to read or write a two- and four-byte big-endian integer values.
 */
 #define get2byte(x)   ((x)[0]<<8 | (x)[1])
 #define put2byte(p,v) ((p)[0] = (u8)((v)>>8), (p)[1] = (u8)(v))
 #define get4byte sqlite3Get4byte
 #define put4byte sqlite3Put4byte
 
+/*
+** get2byteAligned(), unlike get2byte(), requires that its argument point to a
+** two-byte aligned address.  get2bytea() is only used for accessing the
+** cell addresses in a btree header.
+*/
+#if SQLITE_BYTEORDER==4321
+# define get2byteAligned(x)  (*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && GCC_VERSION>=4008000
+# define get2byteAligned(x)  __builtin_bswap16(*(u16*)(x))
+#elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \
+    && defined(_MSC_VER) && _MSC_VER>=1300
+# define get2byteAligned(x)  _byteswap_ushort(*(u16*)(x))
+#else
+# define get2byteAligned(x)  ((x)[0]<<8 | (x)[1])
+#endif
+
 /************** End of btreeInt.h ********************************************/
 /************** Continuing where we left off in btmutex.c ********************/
 #ifndef SQLITE_OMIT_SHARED_CACHE
@@ -47827,7 +57874,7 @@ static void lockBtreeMutex(Btree *p){
 ** Release the BtShared mutex associated with B-Tree handle p and
 ** clear the p->locked boolean.
 */
-static void unlockBtreeMutex(Btree *p){
+static void SQLITE_NOINLINE unlockBtreeMutex(Btree *p){
   BtShared *pBt = p->pBt;
   assert( p->locked==1 );
   assert( sqlite3_mutex_held(pBt->mutex) );
@@ -47838,6 +57885,9 @@ static void unlockBtreeMutex(Btree *p){
   p->locked = 0;
 }
 
+/* Forward reference */
+static void SQLITE_NOINLINE btreeLockCarefully(Btree *p);
+
 /*
 ** Enter a mutex on the given BTree object.
 **
@@ -47855,8 +57905,6 @@ static void unlockBtreeMutex(Btree *p){
 ** subsequent Btrees that desire a lock.
 */
 SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){
-  Btree *pLater;
-
   /* Some basic sanity checking on the Btree.  The list of Btrees
   ** connected by pNext and pPrev should be in sorted order by
   ** Btree.pBt value. All elements of the list should belong to
@@ -47881,9 +57929,20 @@ SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){
   if( !p->sharable ) return;
   p->wantToLock++;
   if( p->locked ) return;
+  btreeLockCarefully(p);
+}
+
+/* This is a helper function for sqlite3BtreeLock(). By moving
+** complex, but seldom used logic, out of sqlite3BtreeLock() and
+** into this routine, we avoid unnecessary stack pointer changes
+** and thus help the sqlite3BtreeLock() routine to run much faster
+** in the common case.
+*/
+static void SQLITE_NOINLINE btreeLockCarefully(Btree *p){
+  Btree *pLater;
 
   /* In most cases, we should be able to acquire the lock we
-  ** want without having to go throught the ascending lock
+  ** want without having to go through the ascending lock
   ** procedure that follows.  Just be sure not to block.
   */
   if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
@@ -47913,10 +57972,12 @@ SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){
   }
 }
 
+
 /*
 ** Exit the recursive mutex on a Btree.
 */
 SQLITE_PRIVATE void sqlite3BtreeLeave(Btree *p){
+  assert( sqlite3_mutex_held(p->db->mutex) );
   if( p->sharable ){
     assert( p->wantToLock>0 );
     p->wantToLock--;
@@ -47944,21 +58005,6 @@ SQLITE_PRIVATE int sqlite3BtreeHoldsMutex(Btree *p){
 #endif
 
 
-#ifndef SQLITE_OMIT_INCRBLOB
-/*
-** Enter and leave a mutex on a Btree given a cursor owned by that
-** Btree.  These entry points are used by incremental I/O and can be
-** omitted if that module is not used.
-*/
-SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
-  sqlite3BtreeEnter(pCur->pBtree);
-}
-SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
-  sqlite3BtreeLeave(pCur->pBtree);
-}
-#endif /* SQLITE_OMIT_INCRBLOB */
-
-
 /*
 ** Enter the mutex on every Btree associated with a database
 ** connection.  This is needed (for example) prior to parsing
@@ -47992,14 +58038,6 @@ SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){
   }
 }
 
-/*
-** Return true if a particular Btree requires a lock.  Return FALSE if
-** no lock is ever required since it is not sharable.
-*/
-SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
-  return p->sharable;
-}
-
 #ifndef NDEBUG
 /*
 ** Return true if the current thread holds the database connection
@@ -48073,6 +58111,25 @@ SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
   }
 }
 #endif /* if SQLITE_THREADSAFE */
+
+#ifndef SQLITE_OMIT_INCRBLOB
+/*
+** Enter a mutex on a Btree given a cursor owned by that Btree. 
+**
+** These entry points are used by incremental I/O only. Enter() is required 
+** any time OMIT_SHARED_CACHE is not defined, regardless of whether or not 
+** the build is threadsafe. Leave() is only required by threadsafe builds.
+*/
+SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){
+  sqlite3BtreeEnter(pCur->pBtree);
+}
+# if SQLITE_THREADSAFE
+SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){
+  sqlite3BtreeLeave(pCur->pBtree);
+}
+# endif
+#endif /* ifndef SQLITE_OMIT_INCRBLOB */
+
 #endif /* ifndef SQLITE_OMIT_SHARED_CACHE */
 
 /************** End of btmutex.c *********************************************/
@@ -48088,10 +58145,11 @@ SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file implements a external (disk-based) database using BTrees.
+** This file implements an external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
 ** Including a description of file format and an overview of operation.
 */
+/* #include "btreeInt.h" */
 
 /*
 ** The header string that appears at the beginning of every
@@ -48121,6 +58179,25 @@ int sqlite3BtreeTrace=1;  /* True to enable tracing */
 */
 #define get2byteNotZero(X)  (((((int)get2byte(X))-1)&0xffff)+1)
 
+/*
+** Values passed as the 5th argument to allocateBtreePage()
+*/
+#define BTALLOC_ANY   0           /* Allocate any page */
+#define BTALLOC_EXACT 1           /* Allocate exact page if possible */
+#define BTALLOC_LE    2           /* Allocate any page <= the parameter */
+
+/*
+** Macro IfNotOmitAV(x) returns (x) if SQLITE_OMIT_AUTOVACUUM is not 
+** defined, or 0 if it is. For example:
+**
+**   bIncrVacuum = IfNotOmitAV(pBtShared->incrVacuum);
+*/
+#ifndef SQLITE_OMIT_AUTOVACUUM
+#define IfNotOmitAV(expr) (expr)
+#else
+#define IfNotOmitAV(expr) 0
+#endif
+
 #ifndef SQLITE_OMIT_SHARED_CACHE
 /*
 ** A list of BtShared objects that are eligible for participation
@@ -48145,7 +58222,7 @@ static BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;
 ** The shared cache setting effects only future calls to
 ** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().
 */
-SQLITE_API int sqlite3_enable_shared_cache(int enable){
+SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int enable){
   sqlite3GlobalConfig.sharedCacheEnabled = enable;
   return SQLITE_OK;
 }
@@ -48221,7 +58298,7 @@ static int hasSharedCacheTableLock(
   ** the correct locks are held.  So do not bother - just return true.
   ** This case does not come up very often anyhow.
   */
-  if( isIndex && (!pSchema || (pSchema->flags&DB_SchemaLoaded)==0) ){
+  if( isIndex && (!pSchema || (pSchema->schemaFlags&DB_SchemaLoaded)==0) ){
     return 1;
   }
 
@@ -48234,6 +58311,12 @@ static int hasSharedCacheTableLock(
     for(p=sqliteHashFirst(&pSchema->idxHash); p; p=sqliteHashNext(p)){
       Index *pIdx = (Index *)sqliteHashData(p);
       if( pIdx->tnum==(int)iRoot ){
+        if( iTab ){
+          /* Two or more indexes share the same root page.  There must
+          ** be imposter tables.  So just return true.  The assert is not
+          ** useful in that case. */
+          return 1;
+        }
         iTab = pIdx->pTable->tnum;
       }
     }
@@ -48321,7 +58404,7 @@ static int querySharedCacheTableLock(Btree *p, Pgno iTab, u8 eLock){
   /* If some other connection is holding an exclusive lock, the
   ** requested lock may not be obtained.
   */
-  if( pBt->pWriter!=p && pBt->isExclusive ){
+  if( pBt->pWriter!=p && (pBt->btsFlags & BTS_EXCLUSIVE)!=0 ){
     sqlite3ConnectionBlocked(p->db, pBt->pWriter->db);
     return SQLITE_LOCKED_SHAREDCACHE;
   }
@@ -48342,7 +58425,7 @@ static int querySharedCacheTableLock(Btree *p, Pgno iTab, u8 eLock){
       sqlite3ConnectionBlocked(p->db, pIter->pBtree->db);
       if( eLock==WRITE_LOCK ){
         assert( p==pBt->pWriter );
-        pBt->isPending = 1;
+        pBt->btsFlags |= BTS_PENDING;
       }
       return SQLITE_LOCKED_SHAREDCACHE;
     }
@@ -48403,7 +58486,7 @@ static int setSharedCacheTableLock(Btree *p, Pgno iTable, u8 eLock){
   if( !pLock ){
     pLock = (BtLock *)sqlite3MallocZero(sizeof(BtLock));
     if( !pLock ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pLock->iTable = iTable;
     pLock->pBtree = p;
@@ -48430,7 +58513,7 @@ static int setSharedCacheTableLock(Btree *p, Pgno iTable, u8 eLock){
 ** the setSharedCacheTableLock() procedure) held by Btree object p.
 **
 ** This function assumes that Btree p has an open read or write 
-** transaction. If it does not, then the BtShared.isPending variable
+** transaction. If it does not, then the BTS_PENDING flag
 ** may be incorrectly cleared.
 */
 static void clearAllSharedCacheTableLocks(Btree *p){
@@ -48443,7 +58526,7 @@ static void clearAllSharedCacheTableLocks(Btree *p){
 
   while( *ppIter ){
     BtLock *pLock = *ppIter;
-    assert( pBt->isExclusive==0 || pBt->pWriter==pLock->pBtree );
+    assert( (pBt->btsFlags & BTS_EXCLUSIVE)==0 || pBt->pWriter==pLock->pBtree );
     assert( pLock->pBtree->inTrans>=pLock->eLock );
     if( pLock->pBtree==p ){
       *ppIter = pLock->pNext;
@@ -48456,22 +58539,21 @@ static void clearAllSharedCacheTableLocks(Btree *p){
     }
   }
 
-  assert( pBt->isPending==0 || pBt->pWriter );
+  assert( (pBt->btsFlags & BTS_PENDING)==0 || pBt->pWriter );
   if( pBt->pWriter==p ){
     pBt->pWriter = 0;
-    pBt->isExclusive = 0;
-    pBt->isPending = 0;
+    pBt->btsFlags &= ~(BTS_EXCLUSIVE|BTS_PENDING);
   }else if( pBt->nTransaction==2 ){
     /* This function is called when Btree p is concluding its 
     ** transaction. If there currently exists a writer, and p is not
     ** that writer, then the number of locks held by connections other
     ** than the writer must be about to drop to zero. In this case
-    ** set the isPending flag to 0.
+    ** set the BTS_PENDING flag to 0.
     **
-    ** If there is not currently a writer, then BtShared.isPending must
+    ** If there is not currently a writer, then BTS_PENDING must
     ** be zero already. So this next line is harmless in that case.
     */
-    pBt->isPending = 0;
+    pBt->btsFlags &= ~BTS_PENDING;
   }
 }
 
@@ -48483,8 +58565,7 @@ static void downgradeAllSharedCacheTableLocks(Btree *p){
   if( pBt->pWriter==p ){
     BtLock *pLock;
     pBt->pWriter = 0;
-    pBt->isExclusive = 0;
-    pBt->isPending = 0;
+    pBt->btsFlags &= ~(BTS_EXCLUSIVE|BTS_PENDING);
     for(pLock=pBt->pLock; pLock; pLock=pLock->pNext){
       assert( pLock->eLock==READ_LOCK || pLock->pBtree==p );
       pLock->eLock = READ_LOCK;
@@ -48505,18 +58586,26 @@ static void releasePage(MemPage *pPage);  /* Forward reference */
 static int cursorHoldsMutex(BtCursor *p){
   return sqlite3_mutex_held(p->pBt->mutex);
 }
-#endif
 
+/* Verify that the cursor and the BtShared agree about what is the current
+** database connetion. This is important in shared-cache mode. If the database 
+** connection pointers get out-of-sync, it is possible for routines like
+** btreeInitPage() to reference an stale connection pointer that references a
+** a connection that has already closed.  This routine is used inside assert()
+** statements only and for the purpose of double-checking that the btree code
+** does keep the database connection pointers up-to-date.
+*/
+static int cursorOwnsBtShared(BtCursor *p){
+  assert( cursorHoldsMutex(p) );
+  return (p->pBtree->db==p->pBt->db);
+}
+#endif
 
-#ifndef SQLITE_OMIT_INCRBLOB
 /*
-** Invalidate the overflow page-list cache for cursor pCur, if any.
+** Invalidate the overflow cache of the cursor passed as the first argument.
+** on the shared btree structure pBt.
 */
-static void invalidateOverflowCache(BtCursor *pCur){
-  assert( cursorHoldsMutex(pCur) );
-  sqlite3_free(pCur->aOverflow);
-  pCur->aOverflow = 0;
-}
+#define invalidateOverflowCache(pCur) (pCur->curFlags &= ~BTCF_ValidOvfl)
 
 /*
 ** Invalidate the overflow page-list cache for all cursors opened
@@ -48530,6 +58619,7 @@ static void invalidateAllOverflowCache(BtShared *pBt){
   }
 }
 
+#ifndef SQLITE_OMIT_INCRBLOB
 /*
 ** This function is called before modifying the contents of a table
 ** to invalidate any incrblob cursors that are open on the
@@ -48549,19 +58639,21 @@ static void invalidateIncrblobCursors(
   int isClearTable        /* True if all rows are being deleted */
 ){
   BtCursor *p;
-  BtShared *pBt = pBtree->pBt;
+  if( pBtree->hasIncrblobCur==0 ) return;
   assert( sqlite3BtreeHoldsMutex(pBtree) );
-  for(p=pBt->pCursor; p; p=p->pNext){
-    if( p->isIncrblobHandle && (isClearTable || p->info.nKey==iRow) ){
-      p->eState = CURSOR_INVALID;
+  pBtree->hasIncrblobCur = 0;
+  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
+    if( (p->curFlags & BTCF_Incrblob)!=0 ){
+      pBtree->hasIncrblobCur = 1;
+      if( isClearTable || p->info.nKey==iRow ){
+        p->eState = CURSOR_INVALID;
+      }
     }
   }
 }
 
 #else
-  /* Stub functions when INCRBLOB is omitted */
-  #define invalidateOverflowCache(x)
-  #define invalidateAllOverflowCache(x)
+  /* Stub function when INCRBLOB is omitted */
   #define invalidateIncrblobCursors(x,y,z)
 #endif /* SQLITE_OMIT_INCRBLOB */
 
@@ -48606,7 +58698,7 @@ static int btreeSetHasContent(BtShared *pBt, Pgno pgno){
     assert( pgno<=pBt->nPage );
     pBt->pHasContent = sqlite3BitvecCreate(pBt->nPage);
     if( !pBt->pHasContent ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
   if( rc==SQLITE_OK && pgno<=sqlite3BitvecSize(pBt->pHasContent) ){
@@ -48637,30 +58729,44 @@ static void btreeClearHasContent(BtShared *pBt){
 }
 
 /*
-** Save the current cursor position in the variables BtCursor.nKey 
-** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
-**
-** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
-** prior to calling this routine.  
+** Release all of the apPage[] pages for a cursor.
 */
-static int saveCursorPosition(BtCursor *pCur){
-  int rc;
+static void btreeReleaseAllCursorPages(BtCursor *pCur){
+  int i;
+  for(i=0; i<=pCur->iPage; i++){
+    releasePage(pCur->apPage[i]);
+    pCur->apPage[i] = 0;
+  }
+  pCur->iPage = -1;
+}
 
+/*
+** The cursor passed as the only argument must point to a valid entry
+** when this function is called (i.e. have eState==CURSOR_VALID). This
+** function saves the current cursor key in variables pCur->nKey and
+** pCur->pKey. SQLITE_OK is returned if successful or an SQLite error 
+** code otherwise.
+**
+** If the cursor is open on an intkey table, then the integer key
+** (the rowid) is stored in pCur->nKey and pCur->pKey is left set to
+** NULL. If the cursor is open on a non-intkey table, then pCur->pKey is 
+** set to point to a malloced buffer pCur->nKey bytes in size containing 
+** the key.
+*/
+static int saveCursorKey(BtCursor *pCur){
+  int rc = SQLITE_OK;
   assert( CURSOR_VALID==pCur->eState );
   assert( 0==pCur->pKey );
   assert( cursorHoldsMutex(pCur) );
 
-  rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
-  assert( rc==SQLITE_OK );  /* KeySize() cannot fail */
-
-  /* If this is an intKey table, then the above call to BtreeKeySize()
-  ** stores the integer key in pCur->nKey. In this case this value is
-  ** all that is required. Otherwise, if pCur is not open on an intKey
-  ** table, then malloc space for and store the pCur->nKey bytes of key 
-  ** data.
-  */
-  if( 0==pCur->apPage[0]->intKey ){
-    void *pKey = sqlite3Malloc( (int)pCur->nKey );
+  if( pCur->curIntKey ){
+    /* Only the rowid is required for a table btree */
+    pCur->nKey = sqlite3BtreeIntegerKey(pCur);
+  }else{
+    /* For an index btree, save the complete key content */
+    void *pKey;
+    pCur->nKey = sqlite3BtreePayloadSize(pCur);
+    pKey = sqlite3Malloc( pCur->nKey );
     if( pKey ){
       rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
       if( rc==SQLITE_OK ){
@@ -48669,43 +58775,103 @@ static int saveCursorPosition(BtCursor *pCur){
         sqlite3_free(pKey);
       }
     }else{
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
   }
-  assert( !pCur->apPage[0]->intKey || !pCur->pKey );
+  assert( !pCur->curIntKey || !pCur->pKey );
+  return rc;
+}
+
+/*
+** Save the current cursor position in the variables BtCursor.nKey 
+** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+**
+** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
+** prior to calling this routine.  
+*/
+static int saveCursorPosition(BtCursor *pCur){
+  int rc;
+
+  assert( CURSOR_VALID==pCur->eState || CURSOR_SKIPNEXT==pCur->eState );
+  assert( 0==pCur->pKey );
+  assert( cursorHoldsMutex(pCur) );
+
+  if( pCur->eState==CURSOR_SKIPNEXT ){
+    pCur->eState = CURSOR_VALID;
+  }else{
+    pCur->skipNext = 0;
+  }
 
+  rc = saveCursorKey(pCur);
   if( rc==SQLITE_OK ){
-    int i;
-    for(i=0; i<=pCur->iPage; i++){
-      releasePage(pCur->apPage[i]);
-      pCur->apPage[i] = 0;
-    }
-    pCur->iPage = -1;
+    btreeReleaseAllCursorPages(pCur);
     pCur->eState = CURSOR_REQUIRESEEK;
   }
 
-  invalidateOverflowCache(pCur);
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl|BTCF_AtLast);
   return rc;
 }
 
+/* Forward reference */
+static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);
+
 /*
 ** Save the positions of all cursors (except pExcept) that are open on
-** the table  with root-page iRoot. Usually, this is called just before cursor
-** pExcept is used to modify the table (BtreeDelete() or BtreeInsert()).
+** the table with root-page iRoot.  "Saving the cursor position" means that
+** the location in the btree is remembered in such a way that it can be
+** moved back to the same spot after the btree has been modified.  This
+** routine is called just before cursor pExcept is used to modify the
+** table, for example in BtreeDelete() or BtreeInsert().
+**
+** If there are two or more cursors on the same btree, then all such 
+** cursors should have their BTCF_Multiple flag set.  The btreeCursor()
+** routine enforces that rule.  This routine only needs to be called in
+** the uncommon case when pExpect has the BTCF_Multiple flag set.
+**
+** If pExpect!=NULL and if no other cursors are found on the same root-page,
+** then the BTCF_Multiple flag on pExpect is cleared, to avoid another
+** pointless call to this routine.
+**
+** Implementation note:  This routine merely checks to see if any cursors
+** need to be saved.  It calls out to saveCursorsOnList() in the (unusual)
+** event that cursors are in need to being saved.
 */
 static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
   BtCursor *p;
   assert( sqlite3_mutex_held(pBt->mutex) );
   assert( pExcept==0 || pExcept->pBt==pBt );
   for(p=pBt->pCursor; p; p=p->pNext){
-    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) && 
-        p->eState==CURSOR_VALID ){
-      int rc = saveCursorPosition(p);
-      if( SQLITE_OK!=rc ){
-        return rc;
+    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ) break;
+  }
+  if( p ) return saveCursorsOnList(p, iRoot, pExcept);
+  if( pExcept ) pExcept->curFlags &= ~BTCF_Multiple;
+  return SQLITE_OK;
+}
+
+/* This helper routine to saveAllCursors does the actual work of saving
+** the cursors if and when a cursor is found that actually requires saving.
+** The common case is that no cursors need to be saved, so this routine is
+** broken out from its caller to avoid unnecessary stack pointer movement.
+*/
+static int SQLITE_NOINLINE saveCursorsOnList(
+  BtCursor *p,         /* The first cursor that needs saving */
+  Pgno iRoot,          /* Only save cursor with this iRoot. Save all if zero */
+  BtCursor *pExcept    /* Do not save this cursor */
+){
+  do{
+    if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
+      if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
+        int rc = saveCursorPosition(p);
+        if( SQLITE_OK!=rc ){
+          return rc;
+        }
+      }else{
+        testcase( p->iPage>0 );
+        btreeReleaseAllCursorPages(p);
       }
     }
-  }
+    p = p->pNext;
+  }while( p );
   return SQLITE_OK;
 }
 
@@ -48733,7 +58899,7 @@ static int btreeMoveto(
 ){
   int rc;                    /* Status code */
   UnpackedRecord *pIdxKey;   /* Unpacked index key */
-  char aSpace[150];          /* Temp space for pIdxKey - to avoid a malloc */
+  char aSpace[200];          /* Temp space for pIdxKey - to avoid a malloc */
   char *pFree = 0;
 
   if( pKey ){
@@ -48741,8 +58907,12 @@ static int btreeMoveto(
     pIdxKey = sqlite3VdbeAllocUnpackedRecord(
         pCur->pKeyInfo, aSpace, sizeof(aSpace), &pFree
     );
-    if( pIdxKey==0 ) return SQLITE_NOMEM;
+    if( pIdxKey==0 ) return SQLITE_NOMEM_BKPT;
     sqlite3VdbeRecordUnpack(pCur->pKeyInfo, (int)nKey, pKey, pIdxKey);
+    if( pIdxKey->nField==0 ){
+      sqlite3DbFree(pCur->pKeyInfo->db, pFree);
+      return SQLITE_CORRUPT_BKPT;
+    }
   }else{
     pIdxKey = 0;
   }
@@ -48762,17 +58932,22 @@ static int btreeMoveto(
 */
 static int btreeRestoreCursorPosition(BtCursor *pCur){
   int rc;
-  assert( cursorHoldsMutex(pCur) );
+  int skipNext;
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState>=CURSOR_REQUIRESEEK );
   if( pCur->eState==CURSOR_FAULT ){
     return pCur->skipNext;
   }
   pCur->eState = CURSOR_INVALID;
-  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
+  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);
   if( rc==SQLITE_OK ){
     sqlite3_free(pCur->pKey);
     pCur->pKey = 0;
     assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
+    pCur->skipNext |= skipNext;
+    if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
+      pCur->eState = CURSOR_SKIPNEXT;
+    }
   }
   return rc;
 }
@@ -48783,29 +58958,73 @@ static int btreeRestoreCursorPosition(BtCursor *pCur){
          SQLITE_OK)
 
 /*
-** Determine whether or not a cursor has moved from the position it
-** was last placed at.  Cursors can move when the row they are pointing
-** at is deleted out from under them.
+** Determine whether or not a cursor has moved from the position where
+** it was last placed, or has been invalidated for any other reason.
+** Cursors can move when the row they are pointing at is deleted out
+** from under them, for example.  Cursor might also move if a btree
+** is rebalanced.
 **
-** This routine returns an error code if something goes wrong.  The
-** integer *pHasMoved is set to one if the cursor has moved and 0 if not.
+** Calling this routine with a NULL cursor pointer returns false.
+**
+** Use the separate sqlite3BtreeCursorRestore() routine to restore a cursor
+** back to where it ought to be if this routine returns true.
 */
-SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor *pCur, int *pHasMoved){
+SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor *pCur){
+  return pCur->eState!=CURSOR_VALID;
+}
+
+/*
+** This routine restores a cursor back to its original position after it
+** has been moved by some outside activity (such as a btree rebalance or
+** a row having been deleted out from under the cursor).  
+**
+** On success, the *pDifferentRow parameter is false if the cursor is left
+** pointing at exactly the same row.  *pDifferntRow is the row the cursor
+** was pointing to has been deleted, forcing the cursor to point to some
+** nearby row.
+**
+** This routine should only be called for a cursor that just returned
+** TRUE from sqlite3BtreeCursorHasMoved().
+*/
+SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor *pCur, int *pDifferentRow){
   int rc;
 
+  assert( pCur!=0 );
+  assert( pCur->eState!=CURSOR_VALID );
   rc = restoreCursorPosition(pCur);
   if( rc ){
-    *pHasMoved = 1;
+    *pDifferentRow = 1;
     return rc;
   }
-  if( pCur->eState!=CURSOR_VALID || pCur->skipNext!=0 ){
-    *pHasMoved = 1;
+  if( pCur->eState!=CURSOR_VALID ){
+    *pDifferentRow = 1;
   }else{
-    *pHasMoved = 0;
+    assert( pCur->skipNext==0 );
+    *pDifferentRow = 0;
   }
   return SQLITE_OK;
 }
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Provide hints to the cursor.  The particular hint given (and the type
+** and number of the varargs parameters) is determined by the eHintType
+** parameter.  See the definitions of the BTREE_HINT_* macros for details.
+*/
+SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor *pCur, int eHintType, ...){
+  /* Used only by system that substitute their own storage engine */
+}
+#endif
+
+/*
+** Provide flag hints to the cursor.
+*/
+SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor *pCur, unsigned x){
+  assert( x==BTREE_SEEK_EQ || x==BTREE_BULKLOAD || x==0 );
+  pCur->hints = x;
+}
+
+
 #ifndef SQLITE_OMIT_AUTOVACUUM
 /*
 ** Given a page number of a regular database page, return the page
@@ -48859,7 +59078,7 @@ static void ptrmapPut(BtShared *pBt, Pgno key, u8 eType, Pgno parent, int *pRC){
     return;
   }
   iPtrmap = PTRMAP_PAGENO(pBt, key);
-  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
   if( rc!=SQLITE_OK ){
     *pRC = rc;
     return;
@@ -48902,7 +59121,7 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
   assert( sqlite3_mutex_held(pBt->mutex) );
 
   iPtrmap = PTRMAP_PAGENO(pBt, key);
-  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
   if( rc!=0 ){
     return rc;
   }
@@ -48934,129 +59153,214 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
 ** the page, 1 means the second cell, and so forth) return a pointer
 ** to the cell content.
 **
+** findCellPastPtr() does the same except it skips past the initial
+** 4-byte child pointer found on interior pages, if there is one.
+**
 ** This routine works only for pages that do not contain overflow cells.
 */
 #define findCell(P,I) \
-  ((P)->aData + ((P)->maskPage & get2byte(&(P)->aData[(P)->cellOffset+2*(I)])))
-#define findCellv2(D,M,O,I) (D+(M&get2byte(D+(O+2*(I)))))
+  ((P)->aData + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
+#define findCellPastPtr(P,I) \
+  ((P)->aDataOfst + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
 
 
 /*
-** This a more complex version of findCell() that works for
-** pages that do contain overflow cells.
+** This is common tail processing for btreeParseCellPtr() and
+** btreeParseCellPtrIndex() for the case when the cell does not fit entirely
+** on a single B-tree page.  Make necessary adjustments to the CellInfo
+** structure.
 */
-static u8 *findOverflowCell(MemPage *pPage, int iCell){
-  int i;
-  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  for(i=pPage->nOverflow-1; i>=0; i--){
-    int k;
-    struct _OvflCell *pOvfl;
-    pOvfl = &pPage->aOvfl[i];
-    k = pOvfl->idx;
-    if( k<=iCell ){
-      if( k==iCell ){
-        return pOvfl->pCell;
-      }
-      iCell--;
-    }
+static SQLITE_NOINLINE void btreeParseCellAdjustSizeForOverflow(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  /* If the payload will not fit completely on the local page, we have
+  ** to decide how much to store locally and how much to spill onto
+  ** overflow pages.  The strategy is to minimize the amount of unused
+  ** space on overflow pages while keeping the amount of local storage
+  ** in between minLocal and maxLocal.
+  **
+  ** Warning:  changing the way overflow payload is distributed in any
+  ** way will result in an incompatible file format.
+  */
+  int minLocal;  /* Minimum amount of payload held locally */
+  int maxLocal;  /* Maximum amount of payload held locally */
+  int surplus;   /* Overflow payload available for local storage */
+
+  minLocal = pPage->minLocal;
+  maxLocal = pPage->maxLocal;
+  surplus = minLocal + (pInfo->nPayload - minLocal)%(pPage->pBt->usableSize-4);
+  testcase( surplus==maxLocal );
+  testcase( surplus==maxLocal+1 );
+  if( surplus <= maxLocal ){
+    pInfo->nLocal = (u16)surplus;
+  }else{
+    pInfo->nLocal = (u16)minLocal;
   }
-  return findCell(pPage, iCell);
+  pInfo->nSize = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell) + 4;
 }
 
 /*
-** Parse a cell content block and fill in the CellInfo structure.  There
-** are two versions of this function.  btreeParseCell() takes a 
-** cell index as the second argument and btreeParseCellPtr() 
-** takes a pointer to the body of the cell as its second argument.
+** The following routines are implementations of the MemPage.xParseCell()
+** method.
+**
+** Parse a cell content block and fill in the CellInfo structure.
 **
-** Within this file, the parseCell() macro can be called instead of
-** btreeParseCellPtr(). Using some compilers, this will be faster.
+** btreeParseCellPtr()        =>   table btree leaf nodes
+** btreeParseCellNoPayload()  =>   table btree internal nodes
+** btreeParseCellPtrIndex()   =>   index btree nodes
+**
+** There is also a wrapper function btreeParseCell() that works for
+** all MemPage types and that references the cell by index rather than
+** by pointer.
 */
+static void btreeParseCellPtrNoPayload(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( pPage->leaf==0 );
+  assert( pPage->childPtrSize==4 );
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER(pPage);
+#endif
+  pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
+  pInfo->nPayload = 0;
+  pInfo->nLocal = 0;
+  pInfo->pPayload = 0;
+  return;
+}
 static void btreeParseCellPtr(
   MemPage *pPage,         /* Page containing the cell */
   u8 *pCell,              /* Pointer to the cell text. */
   CellInfo *pInfo         /* Fill in this structure */
 ){
-  u16 n;                  /* Number bytes in cell content header */
+  u8 *pIter;              /* For scanning through pCell */
   u32 nPayload;           /* Number of bytes of cell payload */
+  u64 iKey;               /* Extracted Key value */
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-
-  pInfo->pCell = pCell;
   assert( pPage->leaf==0 || pPage->leaf==1 );
-  n = pPage->childPtrSize;
-  assert( n==4-4*pPage->leaf );
-  if( pPage->intKey ){
-    if( pPage->hasData ){
-      n += getVarint32(&pCell[n], nPayload);
-    }else{
-      nPayload = 0;
+  assert( pPage->intKeyLeaf );
+  assert( pPage->childPtrSize==0 );
+  pIter = pCell;
+
+  /* The next block of code is equivalent to:
+  **
+  **     pIter += getVarint32(pIter, nPayload);
+  **
+  ** The code is inlined to avoid a function call.
+  */
+  nPayload = *pIter;
+  if( nPayload>=0x80 ){
+    u8 *pEnd = &pIter[8];
+    nPayload &= 0x7f;
+    do{
+      nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+    }while( (*pIter)>=0x80 && pIter<pEnd );
+  }
+  pIter++;
+
+  /* The next block of code is equivalent to:
+  **
+  **     pIter += getVarint(pIter, (u64*)&pInfo->nKey);
+  **
+  ** The code is inlined to avoid a function call.
+  */
+  iKey = *pIter;
+  if( iKey>=0x80 ){
+    u8 *pEnd = &pIter[7];
+    iKey &= 0x7f;
+    while(1){
+      iKey = (iKey<<7) | (*++pIter & 0x7f);
+      if( (*pIter)<0x80 ) break;
+      if( pIter>=pEnd ){
+        iKey = (iKey<<8) | *++pIter;
+        break;
+      }
     }
-    n += getVarint(&pCell[n], (u64*)&pInfo->nKey);
-    pInfo->nData = nPayload;
-  }else{
-    pInfo->nData = 0;
-    n += getVarint32(&pCell[n], nPayload);
-    pInfo->nKey = nPayload;
   }
+  pIter++;
+
+  pInfo->nKey = *(i64*)&iKey;
   pInfo->nPayload = nPayload;
-  pInfo->nHeader = n;
+  pInfo->pPayload = pIter;
   testcase( nPayload==pPage->maxLocal );
   testcase( nPayload==pPage->maxLocal+1 );
-  if( likely(nPayload<=pPage->maxLocal) ){
+  if( nPayload<=pPage->maxLocal ){
     /* This is the (easy) common case where the entire payload fits
     ** on the local page.  No overflow is required.
     */
-    if( (pInfo->nSize = (u16)(n+nPayload))<4 ) pInfo->nSize = 4;
+    pInfo->nSize = nPayload + (u16)(pIter - pCell);
+    if( pInfo->nSize<4 ) pInfo->nSize = 4;
     pInfo->nLocal = (u16)nPayload;
-    pInfo->iOverflow = 0;
   }else{
-    /* If the payload will not fit completely on the local page, we have
-    ** to decide how much to store locally and how much to spill onto
-    ** overflow pages.  The strategy is to minimize the amount of unused
-    ** space on overflow pages while keeping the amount of local storage
-    ** in between minLocal and maxLocal.
-    **
-    ** Warning:  changing the way overflow payload is distributed in any
-    ** way will result in an incompatible file format.
-    */
-    int minLocal;  /* Minimum amount of payload held locally */
-    int maxLocal;  /* Maximum amount of payload held locally */
-    int surplus;   /* Overflow payload available for local storage */
+    btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
+  }
+}
+static void btreeParseCellPtrIndex(
+  MemPage *pPage,         /* Page containing the cell */
+  u8 *pCell,              /* Pointer to the cell text. */
+  CellInfo *pInfo         /* Fill in this structure */
+){
+  u8 *pIter;              /* For scanning through pCell */
+  u32 nPayload;           /* Number of bytes of cell payload */
 
-    minLocal = pPage->minLocal;
-    maxLocal = pPage->maxLocal;
-    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
-    testcase( surplus==maxLocal );
-    testcase( surplus==maxLocal+1 );
-    if( surplus <= maxLocal ){
-      pInfo->nLocal = (u16)surplus;
-    }else{
-      pInfo->nLocal = (u16)minLocal;
-    }
-    pInfo->iOverflow = (u16)(pInfo->nLocal + n);
-    pInfo->nSize = pInfo->iOverflow + 4;
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  assert( pPage->leaf==0 || pPage->leaf==1 );
+  assert( pPage->intKeyLeaf==0 );
+  pIter = pCell + pPage->childPtrSize;
+  nPayload = *pIter;
+  if( nPayload>=0x80 ){
+    u8 *pEnd = &pIter[8];
+    nPayload &= 0x7f;
+    do{
+      nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+    }while( *(pIter)>=0x80 && pIter<pEnd );
+  }
+  pIter++;
+  pInfo->nKey = nPayload;
+  pInfo->nPayload = nPayload;
+  pInfo->pPayload = pIter;
+  testcase( nPayload==pPage->maxLocal );
+  testcase( nPayload==pPage->maxLocal+1 );
+  if( nPayload<=pPage->maxLocal ){
+    /* This is the (easy) common case where the entire payload fits
+    ** on the local page.  No overflow is required.
+    */
+    pInfo->nSize = nPayload + (u16)(pIter - pCell);
+    if( pInfo->nSize<4 ) pInfo->nSize = 4;
+    pInfo->nLocal = (u16)nPayload;
+  }else{
+    btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
   }
 }
-#define parseCell(pPage, iCell, pInfo) \
-  btreeParseCellPtr((pPage), findCell((pPage), (iCell)), (pInfo))
 static void btreeParseCell(
   MemPage *pPage,         /* Page containing the cell */
   int iCell,              /* The cell index.  First cell is 0 */
   CellInfo *pInfo         /* Fill in this structure */
 ){
-  parseCell(pPage, iCell, pInfo);
+  pPage->xParseCell(pPage, findCell(pPage, iCell), pInfo);
 }
 
 /*
+** The following routines are implementations of the MemPage.xCellSize
+** method.
+**
 ** Compute the total number of bytes that a Cell needs in the cell
 ** data area of the btree-page.  The return number includes the cell
 ** data header and the local payload, but not any overflow page or
 ** the space used by the cell pointer.
+**
+** cellSizePtrNoPayload()    =>   table internal nodes
+** cellSizePtr()             =>   all index nodes & table leaf nodes
 */
 static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
-  u8 *pIter = &pCell[pPage->childPtrSize];
-  u32 nSize;
+  u8 *pIter = pCell + pPage->childPtrSize; /* For looping over bytes of pCell */
+  u8 *pEnd;                                /* End mark for a varint */
+  u32 nSize;                               /* Size value to return */
 
 #ifdef SQLITE_DEBUG
   /* The value returned by this function should always be the same as
@@ -49064,29 +59368,31 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
   ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
   ** this function verifies that this invariant is not violated. */
   CellInfo debuginfo;
-  btreeParseCellPtr(pPage, pCell, &debuginfo);
+  pPage->xParseCell(pPage, pCell, &debuginfo);
 #endif
 
+  nSize = *pIter;
+  if( nSize>=0x80 ){
+    pEnd = &pIter[8];
+    nSize &= 0x7f;
+    do{
+      nSize = (nSize<<7) | (*++pIter & 0x7f);
+    }while( *(pIter)>=0x80 && pIter<pEnd );
+  }
+  pIter++;
   if( pPage->intKey ){
-    u8 *pEnd;
-    if( pPage->hasData ){
-      pIter += getVarint32(pIter, nSize);
-    }else{
-      nSize = 0;
-    }
-
     /* pIter now points at the 64-bit integer key value, a variable length 
     ** integer. The following block moves pIter to point at the first byte
     ** past the end of the key value. */
     pEnd = &pIter[9];
     while( (*pIter++)&0x80 && pIter<pEnd );
-  }else{
-    pIter += getVarint32(pIter, nSize);
   }
-
   testcase( nSize==pPage->maxLocal );
   testcase( nSize==pPage->maxLocal+1 );
-  if( nSize>pPage->maxLocal ){
+  if( nSize<=pPage->maxLocal ){
+    nSize += (u32)(pIter - pCell);
+    if( nSize<4 ) nSize = 4;
+  }else{
     int minLocal = pPage->minLocal;
     nSize = minLocal + (nSize - minLocal) % (pPage->pBt->usableSize - 4);
     testcase( nSize==pPage->maxLocal );
@@ -49094,24 +59400,39 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
     if( nSize>pPage->maxLocal ){
       nSize = minLocal;
     }
-    nSize += 4;
+    nSize += 4 + (u16)(pIter - pCell);
   }
-  nSize += (u32)(pIter - pCell);
+  assert( nSize==debuginfo.nSize || CORRUPT_DB );
+  return (u16)nSize;
+}
+static u16 cellSizePtrNoPayload(MemPage *pPage, u8 *pCell){
+  u8 *pIter = pCell + 4; /* For looping over bytes of pCell */
+  u8 *pEnd;              /* End mark for a varint */
 
-  /* The minimum size of any cell is 4 bytes. */
-  if( nSize<4 ){
-    nSize = 4;
-  }
+#ifdef SQLITE_DEBUG
+  /* The value returned by this function should always be the same as
+  ** the (CellInfo.nSize) value found by doing a full parse of the
+  ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
+  ** this function verifies that this invariant is not violated. */
+  CellInfo debuginfo;
+  pPage->xParseCell(pPage, pCell, &debuginfo);
+#else
+  UNUSED_PARAMETER(pPage);
+#endif
 
-  assert( nSize==debuginfo.nSize );
-  return (u16)nSize;
+  assert( pPage->childPtrSize==4 );
+  pEnd = pIter + 9;
+  while( (*pIter++)&0x80 && pIter<pEnd );
+  assert( debuginfo.nSize==(u16)(pIter - pCell) || CORRUPT_DB );
+  return (u16)(pIter - pCell);
 }
 
+
 #ifdef SQLITE_DEBUG
 /* This variation on cellSizePtr() is used inside of assert() statements
 ** only. */
 static u16 cellSize(MemPage *pPage, int iCell){
-  return cellSizePtr(pPage, findCell(pPage, iCell));
+  return pPage->xCellSize(pPage, findCell(pPage, iCell));
 }
 #endif
 
@@ -49125,10 +59446,9 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
   CellInfo info;
   if( *pRC ) return;
   assert( pCell!=0 );
-  btreeParseCellPtr(pPage, pCell, &info);
-  assert( (info.nData+(pPage->intKey?0:info.nKey))==info.nPayload );
-  if( info.iOverflow ){
-    Pgno ovfl = get4byte(&pCell[info.iOverflow]);
+  pPage->xParseCell(pPage, pCell, &info);
+  if( info.nLocal<info.nPayload ){
+    Pgno ovfl = get4byte(&pCell[info.nSize-4]);
     ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);
   }
 }
@@ -49140,10 +59460,15 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
 ** end of the page and all free space is collected into one
 ** big FreeBlk that occurs in between the header and cell
 ** pointer array and the cell content area.
+**
+** EVIDENCE-OF: R-44582-60138 SQLite may from time to time reorganize a
+** b-tree page so that there are no freeblocks or fragment bytes, all
+** unused bytes are contained in the unallocated space region, and all
+** cells are packed tightly at the end of the page.
 */
 static int defragmentPage(MemPage *pPage){
   int i;                     /* Loop counter */
-  int pc;                    /* Address of a i-th cell */
+  int pc;                    /* Address of the i-th cell */
   int hdr;                   /* Offset to the page header */
   int size;                  /* Size of a cell */
   int usableSize;            /* Number of usable bytes on a page */
@@ -49152,6 +59477,7 @@ static int defragmentPage(MemPage *pPage){
   int nCell;                 /* Number of cells on the page */
   unsigned char *data;       /* The page data */
   unsigned char *temp;       /* Temp area for cell content */
+  unsigned char *src;        /* Source of content */
   int iCellFirst;            /* First allowable cell index */
   int iCellLast;             /* Last possible cell index */
 
@@ -49161,15 +59487,13 @@ static int defragmentPage(MemPage *pPage){
   assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
   assert( pPage->nOverflow==0 );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
-  data = pPage->aData;
+  temp = 0;
+  src = data = pPage->aData;
   hdr = pPage->hdrOffset;
   cellOffset = pPage->cellOffset;
   nCell = pPage->nCell;
   assert( nCell==get2byte(&data[hdr+3]) );
   usableSize = pPage->pBt->usableSize;
-  cbrk = get2byte(&data[hdr+5]);
-  memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
   cbrk = usableSize;
   iCellFirst = cellOffset + 2*nCell;
   iCellLast = usableSize - 4;
@@ -49179,31 +59503,31 @@ static int defragmentPage(MemPage *pPage){
     pc = get2byte(pAddr);
     testcase( pc==iCellFirst );
     testcase( pc==iCellLast );
-#if !defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
     /* These conditions have already been verified in btreeInitPage()
-    ** if SQLITE_ENABLE_OVERSIZE_CELL_CHECK is defined 
+    ** if PRAGMA cell_size_check=ON.
     */
     if( pc<iCellFirst || pc>iCellLast ){
       return SQLITE_CORRUPT_BKPT;
     }
-#endif
     assert( pc>=iCellFirst && pc<=iCellLast );
-    size = cellSizePtr(pPage, &temp[pc]);
+    size = pPage->xCellSize(pPage, &src[pc]);
     cbrk -= size;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
-    if( cbrk<iCellFirst ){
-      return SQLITE_CORRUPT_BKPT;
-    }
-#else
     if( cbrk<iCellFirst || pc+size>usableSize ){
       return SQLITE_CORRUPT_BKPT;
     }
-#endif
     assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
     testcase( cbrk+size==usableSize );
     testcase( pc+size==usableSize );
-    memcpy(&data[cbrk], &temp[pc], size);
     put2byte(pAddr, cbrk);
+    if( temp==0 ){
+      int x;
+      if( cbrk==pc ) continue;
+      temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
+      x = get2byte(&data[hdr+5]);
+      memcpy(&temp[x], &data[x], (cbrk+size) - x);
+      src = temp;
+    }
+    memcpy(&data[cbrk], &src[pc], size);
   }
   assert( cbrk>=iCellFirst );
   put2byte(&data[hdr+5], cbrk);
@@ -49219,6 +59543,70 @@ static int defragmentPage(MemPage *pPage){
 }
 
 /*
+** Search the free-list on page pPg for space to store a cell nByte bytes in
+** size. If one can be found, return a pointer to the space and remove it
+** from the free-list.
+**
+** If no suitable space can be found on the free-list, return NULL.
+**
+** This function may detect corruption within pPg.  If corruption is
+** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.
+**
+** Slots on the free list that are between 1 and 3 bytes larger than nByte
+** will be ignored if adding the extra space to the fragmentation count
+** causes the fragmentation count to exceed 60.
+*/
+static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc){
+  const int hdr = pPg->hdrOffset;
+  u8 * const aData = pPg->aData;
+  int iAddr = hdr + 1;
+  int pc = get2byte(&aData[iAddr]);
+  int x;
+  int usableSize = pPg->pBt->usableSize;
+
+  assert( pc>0 );
+  do{
+    int size;            /* Size of the free slot */
+    /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
+    ** increasing offset. */
+    if( pc>usableSize-4 || pc<iAddr+4 ){
+      *pRc = SQLITE_CORRUPT_BKPT;
+      return 0;
+    }
+    /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each
+    ** freeblock form a big-endian integer which is the size of the freeblock
+    ** in bytes, including the 4-byte header. */
+    size = get2byte(&aData[pc+2]);
+    if( (x = size - nByte)>=0 ){
+      testcase( x==4 );
+      testcase( x==3 );
+      if( pc < pPg->cellOffset+2*pPg->nCell || size+pc > usableSize ){
+        *pRc = SQLITE_CORRUPT_BKPT;
+        return 0;
+      }else if( x<4 ){
+        /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
+        ** number of bytes in fragments may not exceed 60. */
+        if( aData[hdr+7]>57 ) return 0;
+
+        /* Remove the slot from the free-list. Update the number of
+        ** fragmented bytes within the page. */
+        memcpy(&aData[iAddr], &aData[pc], 2);
+        aData[hdr+7] += (u8)x;
+      }else{
+        /* The slot remains on the free-list. Reduce its size to account
+         ** for the portion used by the new allocation. */
+        put2byte(&aData[pc+2], x);
+      }
+      return &aData[pc + x];
+    }
+    iAddr = pc;
+    pc = get2byte(&aData[pc]);
+  }while( pc );
+
+  return 0;
+}
+
+/*
 ** Allocate nByte bytes of space from within the B-Tree page passed
 ** as the first argument. Write into *pIdx the index into pPage->aData[]
 ** of the first byte of allocated space. Return either SQLITE_OK or
@@ -49234,11 +59622,9 @@ static int defragmentPage(MemPage *pPage){
 static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   const int hdr = pPage->hdrOffset;    /* Local cache of pPage->hdrOffset */
   u8 * const data = pPage->aData;      /* Local cache of pPage->aData */
-  int nFrag;                           /* Number of fragmented bytes on pPage */
   int top;                             /* First byte of cell content area */
+  int rc = SQLITE_OK;                  /* Integer return code */
   int gap;        /* First byte of gap between cell pointers and cell content */
-  int rc;         /* Integer return code */
-  int usableSize; /* Usable size of the page */
   
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( pPage->pBt );
@@ -49246,62 +59632,50 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   assert( nByte>=0 );  /* Minimum cell size is 4 */
   assert( pPage->nFree>=nByte );
   assert( pPage->nOverflow==0 );
-  usableSize = pPage->pBt->usableSize;
-  assert( nByte < usableSize-8 );
+  assert( nByte < (int)(pPage->pBt->usableSize-8) );
 
-  nFrag = data[hdr+7];
   assert( pPage->cellOffset == hdr + 12 - 4*pPage->leaf );
   gap = pPage->cellOffset + 2*pPage->nCell;
-  top = get2byteNotZero(&data[hdr+5]);
-  if( gap>top ) return SQLITE_CORRUPT_BKPT;
+  assert( gap<=65536 );
+  /* EVIDENCE-OF: R-29356-02391 If the database uses a 65536-byte page size
+  ** and the reserved space is zero (the usual value for reserved space)
+  ** then the cell content offset of an empty page wants to be 65536.
+  ** However, that integer is too large to be stored in a 2-byte unsigned
+  ** integer, so a value of 0 is used in its place. */
+  top = get2byte(&data[hdr+5]);
+  assert( top<=(int)pPage->pBt->usableSize ); /* Prevent by getAndInitPage() */
+  if( gap>top ){
+    if( top==0 && pPage->pBt->usableSize==65536 ){
+      top = 65536;
+    }else{
+      return SQLITE_CORRUPT_BKPT;
+    }
+  }
+
+  /* If there is enough space between gap and top for one more cell pointer
+  ** array entry offset, and if the freelist is not empty, then search the
+  ** freelist looking for a free slot big enough to satisfy the request.
+  */
   testcase( gap+2==top );
   testcase( gap+1==top );
   testcase( gap==top );
-
-  if( nFrag>=60 ){
-    /* Always defragment highly fragmented pages */
-    rc = defragmentPage(pPage);
-    if( rc ) return rc;
-    top = get2byteNotZero(&data[hdr+5]);
-  }else if( gap+2<=top ){
-    /* Search the freelist looking for a free slot big enough to satisfy 
-    ** the request. The allocation is made from the first free slot in 
-    ** the list that is large enough to accomadate it.
-    */
-    int pc, addr;
-    for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
-      int size;            /* Size of the free slot */
-      if( pc>usableSize-4 || pc<addr+4 ){
-        return SQLITE_CORRUPT_BKPT;
-      }
-      size = get2byte(&data[pc+2]);
-      if( size>=nByte ){
-        int x = size - nByte;
-        testcase( x==4 );
-        testcase( x==3 );
-        if( x<4 ){
-          /* Remove the slot from the free-list. Update the number of
-          ** fragmented bytes within the page. */
-          memcpy(&data[addr], &data[pc], 2);
-          data[hdr+7] = (u8)(nFrag + x);
-        }else if( size+pc > usableSize ){
-          return SQLITE_CORRUPT_BKPT;
-        }else{
-          /* The slot remains on the free-list. Reduce its size to account
-          ** for the portion used by the new allocation. */
-          put2byte(&data[pc+2], x);
-        }
-        *pIdx = pc + x;
-        return SQLITE_OK;
-      }
+  if( (data[hdr+2] || data[hdr+1]) && gap+2<=top ){
+    u8 *pSpace = pageFindSlot(pPage, nByte, &rc);
+    if( pSpace ){
+      assert( pSpace>=data && (pSpace - data)<65536 );
+      *pIdx = (int)(pSpace - data);
+      return SQLITE_OK;
+    }else if( rc ){
+      return rc;
     }
   }
 
-  /* Check to make sure there is enough space in the gap to satisfy
-  ** the allocation.  If not, defragment.
+  /* The request could not be fulfilled using a freelist slot.  Check
+  ** to see if defragmentation is necessary.
   */
   testcase( gap+2+nByte==top );
   if( gap+2+nByte>top ){
+    assert( pPage->nCell>0 || CORRUPT_DB );
     rc = defragmentPage(pPage);
     if( rc ) return rc;
     top = get2byteNotZero(&data[hdr+5]);
@@ -49324,90 +59698,101 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
 
 /*
 ** Return a section of the pPage->aData to the freelist.
-** The first byte of the new free block is pPage->aDisk[start]
-** and the size of the block is "size" bytes.
-**
-** Most of the effort here is involved in coalesing adjacent
-** free blocks into a single big free block.
-*/
-static int freeSpace(MemPage *pPage, int start, int size){
-  int addr, pbegin, hdr;
-  int iLast;                        /* Largest possible freeblock offset */
-  unsigned char *data = pPage->aData;
+** The first byte of the new free block is pPage->aData[iStart]
+** and the size of the block is iSize bytes.
+**
+** Adjacent freeblocks are coalesced.
+**
+** Note that even though the freeblock list was checked by btreeInitPage(),
+** that routine will not detect overlap between cells or freeblocks.  Nor
+** does it detect cells or freeblocks that encrouch into the reserved bytes
+** at the end of the page.  So do additional corruption checks inside this
+** routine and return SQLITE_CORRUPT if any problems are found.
+*/
+static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
+  u16 iPtr;                             /* Address of ptr to next freeblock */
+  u16 iFreeBlk;                         /* Address of the next freeblock */
+  u8 hdr;                               /* Page header size.  0 or 100 */
+  u8 nFrag = 0;                         /* Reduction in fragmentation */
+  u16 iOrigSize = iSize;                /* Original value of iSize */
+  u32 iLast = pPage->pBt->usableSize-4; /* Largest possible freeblock offset */
+  u32 iEnd = iStart + iSize;            /* First byte past the iStart buffer */
+  unsigned char *data = pPage->aData;   /* Page content */
 
   assert( pPage->pBt!=0 );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
-  assert( start>=pPage->hdrOffset+6+pPage->childPtrSize );
-  assert( (start + size) <= (int)pPage->pBt->usableSize );
+  assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
+  assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  assert( size>=0 );   /* Minimum cell size is 4 */
+  assert( iSize>=4 );   /* Minimum cell size is 4 */
+  assert( iStart<=iLast );
 
-  if( pPage->pBt->secureDelete ){
-    /* Overwrite deleted information with zeros when the secure_delete
-    ** option is enabled */
-    memset(&data[start], 0, size);
+  /* Overwrite deleted information with zeros when the secure_delete
+  ** option is enabled */
+  if( pPage->pBt->btsFlags & BTS_SECURE_DELETE ){
+    memset(&data[iStart], 0, iSize);
   }
 
-  /* Add the space back into the linked list of freeblocks.  Note that
-  ** even though the freeblock list was checked by btreeInitPage(),
-  ** btreeInitPage() did not detect overlapping cells or
-  ** freeblocks that overlapped cells.   Nor does it detect when the
-  ** cell content area exceeds the value in the page header.  If these
-  ** situations arise, then subsequent insert operations might corrupt
-  ** the freelist.  So we do need to check for corruption while scanning
-  ** the freelist.
+  /* The list of freeblocks must be in ascending order.  Find the 
+  ** spot on the list where iStart should be inserted.
   */
   hdr = pPage->hdrOffset;
-  addr = hdr + 1;
-  iLast = pPage->pBt->usableSize - 4;
-  assert( start<=iLast );
-  while( (pbegin = get2byte(&data[addr]))<start && pbegin>0 ){
-    if( pbegin<addr+4 ){
-      return SQLITE_CORRUPT_BKPT;
+  iPtr = hdr + 1;
+  if( data[iPtr+1]==0 && data[iPtr]==0 ){
+    iFreeBlk = 0;  /* Shortcut for the case when the freelist is empty */
+  }else{
+    while( (iFreeBlk = get2byte(&data[iPtr]))>0 && iFreeBlk<iStart ){
+      if( iFreeBlk<iPtr+4 ) return SQLITE_CORRUPT_BKPT;
+      iPtr = iFreeBlk;
     }
-    addr = pbegin;
-  }
-  if( pbegin>iLast ){
-    return SQLITE_CORRUPT_BKPT;
-  }
-  assert( pbegin>addr || pbegin==0 );
-  put2byte(&data[addr], start);
-  put2byte(&data[start], pbegin);
-  put2byte(&data[start+2], size);
-  pPage->nFree = pPage->nFree + (u16)size;
-
-  /* Coalesce adjacent free blocks */
-  addr = hdr + 1;
-  while( (pbegin = get2byte(&data[addr]))>0 ){
-    int pnext, psize, x;
-    assert( pbegin>addr );
-    assert( pbegin <= (int)pPage->pBt->usableSize-4 );
-    pnext = get2byte(&data[pbegin]);
-    psize = get2byte(&data[pbegin+2]);
-    if( pbegin + psize + 3 >= pnext && pnext>0 ){
-      int frag = pnext - (pbegin+psize);
-      if( (frag<0) || (frag>(int)data[hdr+7]) ){
-        return SQLITE_CORRUPT_BKPT;
-      }
-      data[hdr+7] -= (u8)frag;
-      x = get2byte(&data[pnext]);
-      put2byte(&data[pbegin], x);
-      x = pnext + get2byte(&data[pnext+2]) - pbegin;
-      put2byte(&data[pbegin+2], x);
-    }else{
-      addr = pbegin;
+    if( iFreeBlk>iLast ) return SQLITE_CORRUPT_BKPT;
+    assert( iFreeBlk>iPtr || iFreeBlk==0 );
+  
+    /* At this point:
+    **    iFreeBlk:   First freeblock after iStart, or zero if none
+    **    iPtr:       The address of a pointer to iFreeBlk
+    **
+    ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
+    */
+    if( iFreeBlk && iEnd+3>=iFreeBlk ){
+      nFrag = iFreeBlk - iEnd;
+      if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_BKPT;
+      iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
+      if( iEnd > pPage->pBt->usableSize ) return SQLITE_CORRUPT_BKPT;
+      iSize = iEnd - iStart;
+      iFreeBlk = get2byte(&data[iFreeBlk]);
     }
+  
+    /* If iPtr is another freeblock (that is, if iPtr is not the freelist
+    ** pointer in the page header) then check to see if iStart should be
+    ** coalesced onto the end of iPtr.
+    */
+    if( iPtr>hdr+1 ){
+      int iPtrEnd = iPtr + get2byte(&data[iPtr+2]);
+      if( iPtrEnd+3>=iStart ){
+        if( iPtrEnd>iStart ) return SQLITE_CORRUPT_BKPT;
+        nFrag += iStart - iPtrEnd;
+        iSize = iEnd - iPtr;
+        iStart = iPtr;
+      }
+    }
+    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_BKPT;
+    data[hdr+7] -= nFrag;
+  }
+  if( iStart==get2byte(&data[hdr+5]) ){
+    /* The new freeblock is at the beginning of the cell content area,
+    ** so just extend the cell content area rather than create another
+    ** freelist entry */
+    if( iPtr!=hdr+1 ) return SQLITE_CORRUPT_BKPT;
+    put2byte(&data[hdr+1], iFreeBlk);
+    put2byte(&data[hdr+5], iEnd);
+  }else{
+    /* Insert the new freeblock into the freelist */
+    put2byte(&data[iPtr], iStart);
+    put2byte(&data[iStart], iFreeBlk);
+    put2byte(&data[iStart+2], iSize);
   }
-
-  /* If the cell content area begins with a freeblock, remove it. */
-  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
-    int top;
-    pbegin = get2byte(&data[hdr+1]);
-    memcpy(&data[hdr+1], &data[pbegin], 2);
-    top = get2byte(&data[hdr+5]) + get2byte(&data[pbegin+2]);
-    put2byte(&data[hdr+5], top);
-  }
-  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  pPage->nFree += iOrigSize;
   return SQLITE_OK;
 }
 
@@ -49431,20 +59816,44 @@ static int decodeFlags(MemPage *pPage, int flagByte){
   pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
   flagByte &= ~PTF_LEAF;
   pPage->childPtrSize = 4-4*pPage->leaf;
+  pPage->xCellSize = cellSizePtr;
   pBt = pPage->pBt;
   if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
+    /* EVIDENCE-OF: R-07291-35328 A value of 5 (0x05) means the page is an
+    ** interior table b-tree page. */
+    assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
+    /* EVIDENCE-OF: R-26900-09176 A value of 13 (0x0d) means the page is a
+    ** leaf table b-tree page. */
+    assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
     pPage->intKey = 1;
-    pPage->hasData = pPage->leaf;
+    if( pPage->leaf ){
+      pPage->intKeyLeaf = 1;
+      pPage->xParseCell = btreeParseCellPtr;
+    }else{
+      pPage->intKeyLeaf = 0;
+      pPage->xCellSize = cellSizePtrNoPayload;
+      pPage->xParseCell = btreeParseCellPtrNoPayload;
+    }
     pPage->maxLocal = pBt->maxLeaf;
     pPage->minLocal = pBt->minLeaf;
   }else if( flagByte==PTF_ZERODATA ){
+    /* EVIDENCE-OF: R-43316-37308 A value of 2 (0x02) means the page is an
+    ** interior index b-tree page. */
+    assert( (PTF_ZERODATA)==2 );
+    /* EVIDENCE-OF: R-59615-42828 A value of 10 (0x0a) means the page is a
+    ** leaf index b-tree page. */
+    assert( (PTF_ZERODATA|PTF_LEAF)==10 );
     pPage->intKey = 0;
-    pPage->hasData = 0;
+    pPage->intKeyLeaf = 0;
+    pPage->xParseCell = btreeParseCellPtrIndex;
     pPage->maxLocal = pBt->maxLocal;
     pPage->minLocal = pBt->minLocal;
   }else{
+    /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
+    ** an error. */
     return SQLITE_CORRUPT_BKPT;
   }
+  pPage->max1bytePayload = pBt->max1bytePayload;
   return SQLITE_OK;
 }
 
@@ -49460,6 +59869,7 @@ static int decodeFlags(MemPage *pPage, int flagByte){
 static int btreeInitPage(MemPage *pPage){
 
   assert( pPage->pBt!=0 );
+  assert( pPage->pBt->db!=0 );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
   assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
@@ -49481,19 +59891,34 @@ static int btreeInitPage(MemPage *pPage){
 
     hdr = pPage->hdrOffset;
     data = pPage->aData;
+    /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
+    ** the b-tree page type. */
     if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
     assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
     pPage->maskPage = (u16)(pBt->pageSize - 1);
     pPage->nOverflow = 0;
     usableSize = pBt->usableSize;
-    pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
+    pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
+    pPage->aDataEnd = &data[usableSize];
+    pPage->aCellIdx = &data[cellOffset];
+    pPage->aDataOfst = &data[pPage->childPtrSize];
+    /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
+    ** the start of the cell content area. A zero value for this integer is
+    ** interpreted as 65536. */
     top = get2byteNotZero(&data[hdr+5]);
+    /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+    ** number of cells on the page. */
     pPage->nCell = get2byte(&data[hdr+3]);
     if( pPage->nCell>MX_CELL(pBt) ){
       /* To many cells for a single page.  The page must be corrupt */
       return SQLITE_CORRUPT_BKPT;
     }
     testcase( pPage->nCell==MX_CELL(pBt) );
+    /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
+    ** possible for a root page of a table that contains no rows) then the
+    ** offset to the cell content area will equal the page size minus the
+    ** bytes of reserved space. */
+    assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );
 
     /* A malformed database page might cause us to read past the end
     ** of page when parsing a cell.  
@@ -49504,20 +59929,19 @@ static int btreeInitPage(MemPage *pPage){
     */
     iCellFirst = cellOffset + 2*pPage->nCell;
     iCellLast = usableSize - 4;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
-    {
+    if( pBt->db->flags & SQLITE_CellSizeCk ){
       int i;            /* Index into the cell pointer array */
       int sz;           /* Size of a cell */
 
       if( !pPage->leaf ) iCellLast--;
       for(i=0; i<pPage->nCell; i++){
-        pc = get2byte(&data[cellOffset+i*2]);
+        pc = get2byteAligned(&data[cellOffset+i*2]);
         testcase( pc==iCellFirst );
         testcase( pc==iCellLast );
         if( pc<iCellFirst || pc>iCellLast ){
           return SQLITE_CORRUPT_BKPT;
         }
-        sz = cellSizePtr(pPage, &data[pc]);
+        sz = pPage->xCellSize(pPage, &data[pc]);
         testcase( pc+sz==usableSize );
         if( pc+sz>usableSize ){
           return SQLITE_CORRUPT_BKPT;
@@ -49525,22 +59949,28 @@ static int btreeInitPage(MemPage *pPage){
       }
       if( !pPage->leaf ) iCellLast++;
     }  
-#endif
 
-    /* Compute the total free space on the page */
+    /* Compute the total free space on the page
+    ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
+    ** start of the first freeblock on the page, or is zero if there are no
+    ** freeblocks. */
     pc = get2byte(&data[hdr+1]);
-    nFree = data[hdr+7] + top;
+    nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */
     while( pc>0 ){
       u16 next, size;
       if( pc<iCellFirst || pc>iCellLast ){
-        /* Start of free block is off the page */
+        /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
+        ** always be at least one cell before the first freeblock.
+        **
+        ** Or, the freeblock is off the end of the page
+        */
         return SQLITE_CORRUPT_BKPT; 
       }
       next = get2byte(&data[pc]);
       size = get2byte(&data[pc+2]);
       if( (next>0 && next<=pc+size+3) || pc+size>usableSize ){
         /* Free blocks must be in ascending order. And the last byte of
-	** the free-block must lie on the database page.  */
+        ** the free-block must lie on the database page.  */
         return SQLITE_CORRUPT_BKPT; 
       }
       nFree = nFree + size;
@@ -49578,18 +60008,20 @@ static void zeroPage(MemPage *pPage, int flags){
   assert( sqlite3PagerGetData(pPage->pDbPage) == data );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( sqlite3_mutex_held(pBt->mutex) );
-  if( pBt->secureDelete ){
+  if( pBt->btsFlags & BTS_SECURE_DELETE ){
     memset(&data[hdr], 0, pBt->usableSize - hdr);
   }
   data[hdr] = (char)flags;
-  first = hdr + 8 + 4*((flags&PTF_LEAF)==0 ?1:0);
+  first = hdr + ((flags&PTF_LEAF)==0 ? 12 : 8);
   memset(&data[hdr+1], 0, 4);
   data[hdr+7] = 0;
   put2byte(&data[hdr+5], pBt->usableSize);
   pPage->nFree = (u16)(pBt->usableSize - first);
   decodeFlags(pPage, flags);
-  pPage->hdrOffset = hdr;
   pPage->cellOffset = first;
+  pPage->aDataEnd = &data[pBt->usableSize];
+  pPage->aCellIdx = &data[first];
+  pPage->aDataOfst = &data[pPage->childPtrSize];
   pPage->nOverflow = 0;
   assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
   pPage->maskPage = (u16)(pBt->pageSize - 1);
@@ -49604,20 +60036,23 @@ static void zeroPage(MemPage *pPage, int flags){
 */
 static MemPage *btreePageFromDbPage(DbPage *pDbPage, Pgno pgno, BtShared *pBt){
   MemPage *pPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
-  pPage->aData = sqlite3PagerGetData(pDbPage);
-  pPage->pDbPage = pDbPage;
-  pPage->pBt = pBt;
-  pPage->pgno = pgno;
-  pPage->hdrOffset = pPage->pgno==1 ? 100 : 0;
+  if( pgno!=pPage->pgno ){
+    pPage->aData = sqlite3PagerGetData(pDbPage);
+    pPage->pDbPage = pDbPage;
+    pPage->pBt = pBt;
+    pPage->pgno = pgno;
+    pPage->hdrOffset = pgno==1 ? 100 : 0;
+  }
+  assert( pPage->aData==sqlite3PagerGetData(pDbPage) );
   return pPage; 
 }
 
 /*
 ** Get a page from the pager.  Initialize the MemPage.pBt and
-** MemPage.aData elements if needed.
+** MemPage.aData elements if needed.  See also: btreeGetUnusedPage().
 **
-** If the noContent flag is set, it means that we do not care about
-** the content of the page at this time.  So do not go to the disk
+** If the PAGER_GET_NOCONTENT flag is set, it means that we do not care
+** about the content of the page at this time.  So do not go to the disk
 ** to fetch the content.  Just fill in the content with zeros for now.
 ** If in the future we call sqlite3PagerWrite() on this page, that
 ** means we have started to be concerned about content and the disk
@@ -49627,13 +60062,14 @@ static int btreeGetPage(
   BtShared *pBt,       /* The btree */
   Pgno pgno,           /* Number of the page to fetch */
   MemPage **ppPage,    /* Return the page in this parameter */
-  int noContent        /* Do not load page content if true */
+  int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */
 ){
   int rc;
   DbPage *pDbPage;
 
+  assert( flags==0 || flags==PAGER_GET_NOCONTENT || flags==PAGER_GET_READONLY );
   assert( sqlite3_mutex_held(pBt->mutex) );
-  rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, noContent);
+  rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
   if( rc ) return rc;
   *ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
   return SQLITE_OK;
@@ -49664,37 +60100,67 @@ static Pgno btreePagecount(BtShared *pBt){
 SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree *p){
   assert( sqlite3BtreeHoldsMutex(p) );
   assert( ((p->pBt->nPage)&0x8000000)==0 );
-  return (int)btreePagecount(p->pBt);
+  return btreePagecount(p->pBt);
 }
 
 /*
-** Get a page from the pager and initialize it.  This routine is just a
-** convenience wrapper around separate calls to btreeGetPage() and 
-** btreeInitPage().
+** Get a page from the pager and initialize it.
+**
+** If pCur!=0 then the page is being fetched as part of a moveToChild()
+** call.  Do additional sanity checking on the page in this case.
+** And if the fetch fails, this routine must decrement pCur->iPage.
 **
-** If an error occurs, then the value *ppPage is set to is undefined. It
+** The page is fetched as read-write unless pCur is not NULL and is
+** a read-only cursor.
+**
+** If an error occurs, then *ppPage is undefined. It
 ** may remain unchanged, or it may be set to an invalid value.
 */
 static int getAndInitPage(
-  BtShared *pBt,          /* The database file */
-  Pgno pgno,           /* Number of the page to get */
-  MemPage **ppPage     /* Write the page pointer here */
+  BtShared *pBt,                  /* The database file */
+  Pgno pgno,                      /* Number of the page to get */
+  MemPage **ppPage,               /* Write the page pointer here */
+  BtCursor *pCur,                 /* Cursor to receive the page, or NULL */
+  int bReadOnly                   /* True for a read-only page */
 ){
   int rc;
+  DbPage *pDbPage;
   assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( pCur==0 || ppPage==&pCur->apPage[pCur->iPage] );
+  assert( pCur==0 || bReadOnly==pCur->curPagerFlags );
+  assert( pCur==0 || pCur->iPage>0 );
 
   if( pgno>btreePagecount(pBt) ){
     rc = SQLITE_CORRUPT_BKPT;
-  }else{
-    rc = btreeGetPage(pBt, pgno, ppPage, 0);
-    if( rc==SQLITE_OK ){
-      rc = btreeInitPage(*ppPage);
-      if( rc!=SQLITE_OK ){
-        releasePage(*ppPage);
-      }
+    goto getAndInitPage_error;
+  }
+  rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, bReadOnly);
+  if( rc ){
+    goto getAndInitPage_error;
+  }
+  *ppPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
+  if( (*ppPage)->isInit==0 ){
+    btreePageFromDbPage(pDbPage, pgno, pBt);
+    rc = btreeInitPage(*ppPage);
+    if( rc!=SQLITE_OK ){
+      releasePage(*ppPage);
+      goto getAndInitPage_error;
     }
   }
+  assert( (*ppPage)->pgno==pgno );
+  assert( (*ppPage)->aData==sqlite3PagerGetData(pDbPage) );
+
+  /* If obtaining a child page for a cursor, we must verify that the page is
+  ** compatible with the root page. */
+  if( pCur && ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->curIntKey) ){
+    rc = SQLITE_CORRUPT_BKPT;
+    releasePage(*ppPage);
+    goto getAndInitPage_error;
+  }
+  return SQLITE_OK;
 
+getAndInitPage_error:
+  if( pCur ) pCur->iPage--;
   testcase( pgno==0 );
   assert( pgno!=0 || rc==SQLITE_CORRUPT );
   return rc;
@@ -49704,17 +60170,49 @@ static int getAndInitPage(
 ** Release a MemPage.  This should be called once for each prior
 ** call to btreeGetPage.
 */
+static void releasePageNotNull(MemPage *pPage){
+  assert( pPage->aData );
+  assert( pPage->pBt );
+  assert( pPage->pDbPage!=0 );
+  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+  assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
+  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+  sqlite3PagerUnrefNotNull(pPage->pDbPage);
+}
 static void releasePage(MemPage *pPage){
-  if( pPage ){
-    assert( pPage->aData );
-    assert( pPage->pBt );
-    assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
-    assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
-    assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-    sqlite3PagerUnref(pPage->pDbPage);
+  if( pPage ) releasePageNotNull(pPage);
+}
+
+/*
+** Get an unused page.
+**
+** This works just like btreeGetPage() with the addition:
+**
+**   *  If the page is already in use for some other purpose, immediately
+**      release it and return an SQLITE_CURRUPT error.
+**   *  Make sure the isInit flag is clear
+*/
+static int btreeGetUnusedPage(
+  BtShared *pBt,       /* The btree */
+  Pgno pgno,           /* Number of the page to fetch */
+  MemPage **ppPage,    /* Return the page in this parameter */
+  int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */
+){
+  int rc = btreeGetPage(pBt, pgno, ppPage, flags);
+  if( rc==SQLITE_OK ){
+    if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
+      releasePage(*ppPage);
+      *ppPage = 0;
+      return SQLITE_CORRUPT_BKPT;
+    }
+    (*ppPage)->isInit = 0;
+  }else{
+    *ppPage = 0;
   }
+  return rc;
 }
 
+
 /*
 ** During a rollback, when the pager reloads information into the cache
 ** so that the cache is restored to its original state at the start of
@@ -49764,11 +60262,8 @@ static int btreeInvokeBusyHandler(void *pArg){
 ** If zFilename is ":memory:" then an in-memory database is created
 ** that is automatically destroyed when it is closed.
 **
-** The "flags" parameter is a bitmask that might contain bits
-** BTREE_OMIT_JOURNAL and/or BTREE_NO_READLOCK.  The BTREE_NO_READLOCK
-** bit is also set if the SQLITE_NoReadlock flags is set in db->flags.
-** These flags are passed through into sqlite3PagerOpen() and must
-** be the same values as PAGER_OMIT_JOURNAL and PAGER_NO_READLOCK.
+** The "flags" parameter is a bitmask that might contain bits like
+** BTREE_OMIT_JOURNAL and/or BTREE_MEMORY.
 **
 ** If the database is already opened in the same database connection
 ** and we are in shared cache mode, then the open will fail with an
@@ -49801,7 +60296,8 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   const int isMemdb = 0;
 #else
   const int isMemdb = (zFilename && strcmp(zFilename, ":memory:")==0)
-                       || (isTempDb && sqlite3TempInMemory(db));
+                       || (isTempDb && sqlite3TempInMemory(db))
+                       || (vfsFlags & SQLITE_OPEN_MEMORY)!=0;
 #endif
 
   assert( db!=0 );
@@ -49815,9 +60311,6 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   /* A BTREE_SINGLE database is always a temporary and/or ephemeral */
   assert( (flags & BTREE_SINGLE)==0 || isTempDb );
 
-  if( db->flags & SQLITE_NoReadlock ){
-    flags |= BTREE_NO_READLOCK;
-  }
   if( isMemdb ){
     flags |= BTREE_MEMORY;
   }
@@ -49826,7 +60319,7 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   }
   p = sqlite3MallocZero(sizeof(Btree));
   if( !p ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   p->inTrans = TRANS_NONE;
   p->db = db;
@@ -49840,17 +60333,29 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   ** If this Btree is a candidate for shared cache, try to find an
   ** existing BtShared object that we can share with
   */
-  if( isMemdb==0 && isTempDb==0 ){
+  if( isTempDb==0 && (isMemdb==0 || (vfsFlags&SQLITE_OPEN_URI)!=0) ){
     if( vfsFlags & SQLITE_OPEN_SHAREDCACHE ){
+      int nFilename = sqlite3Strlen30(zFilename)+1;
       int nFullPathname = pVfs->mxPathname+1;
-      char *zFullPathname = sqlite3Malloc(nFullPathname);
+      char *zFullPathname = sqlite3Malloc(MAX(nFullPathname,nFilename));
       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
+
       p->sharable = 1;
       if( !zFullPathname ){
         sqlite3_free(p);
-        return SQLITE_NOMEM;
+        return SQLITE_NOMEM_BKPT;
+      }
+      if( isMemdb ){
+        memcpy(zFullPathname, zFilename, nFilename);
+      }else{
+        rc = sqlite3OsFullPathname(pVfs, zFilename,
+                                   nFullPathname, zFullPathname);
+        if( rc ){
+          sqlite3_free(zFullPathname);
+          sqlite3_free(p);
+          return rc;
+        }
       }
-      sqlite3OsFullPathname(pVfs, zFilename, nFullPathname, zFullPathname);
 #if SQLITE_THREADSAFE
       mutexOpen = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_OPEN);
       sqlite3_mutex_enter(mutexOpen);
@@ -49859,7 +60364,7 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 #endif
       for(pBt=GLOBAL(BtShared*,sqlite3SharedCacheList); pBt; pBt=pBt->pNext){
         assert( pBt->nRef>0 );
-        if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager))
+        if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager, 0))
                  && sqlite3PagerVfs(pBt->pPager)==pVfs ){
           int iDb;
           for(iDb=db->nDb-1; iDb>=0; iDb--){
@@ -49898,20 +60403,21 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
     ** the right size.  This is to guard against size changes that result
     ** when compiling on a different architecture.
     */
-    assert( sizeof(i64)==8 || sizeof(i64)==4 );
-    assert( sizeof(u64)==8 || sizeof(u64)==4 );
+    assert( sizeof(i64)==8 );
+    assert( sizeof(u64)==8 );
     assert( sizeof(u32)==4 );
     assert( sizeof(u16)==2 );
     assert( sizeof(Pgno)==4 );
   
     pBt = sqlite3MallocZero( sizeof(*pBt) );
     if( pBt==0 ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto btree_open_out;
     }
     rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
                           EXTRA_SIZE, flags, vfsFlags, pageReinit);
     if( rc==SQLITE_OK ){
+      sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);
       rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
     }
     if( rc!=SQLITE_OK ){
@@ -49924,10 +60430,13 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
   
     pBt->pCursor = 0;
     pBt->pPage1 = 0;
-    pBt->readOnly = sqlite3PagerIsreadonly(pBt->pPager);
+    if( sqlite3PagerIsreadonly(pBt->pPager) ) pBt->btsFlags |= BTS_READ_ONLY;
 #ifdef SQLITE_SECURE_DELETE
-    pBt->secureDelete = 1;
+    pBt->btsFlags |= BTS_SECURE_DELETE;
 #endif
+    /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
+    ** determined by the 2-byte integer located at an offset of 16 bytes from
+    ** the beginning of the database file. */
     pBt->pageSize = (zDbHeader[16]<<8) | (zDbHeader[17]<<16);
     if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
          || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
@@ -49946,8 +60455,11 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 #endif
       nReserve = 0;
     }else{
+      /* EVIDENCE-OF: R-37497-42412 The size of the reserved region is
+      ** determined by the one-byte unsigned integer found at an offset of 20
+      ** into the database file header. */
       nReserve = zDbHeader[20];
-      pBt->pageSizeFixed = 1;
+      pBt->btsFlags |= BTS_PAGESIZE_FIXED;
 #ifndef SQLITE_OMIT_AUTOVACUUM
       pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
       pBt->incrVacuum = (get4byte(&zDbHeader[36 + 7*4])?1:0);
@@ -49961,15 +60473,14 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
     /* Add the new BtShared object to the linked list sharable BtShareds.
     */
+    pBt->nRef = 1;
     if( p->sharable ){
       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
-      pBt->nRef = 1;
       MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);)
       if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
         pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
         if( pBt->mutex==0 ){
-          rc = SQLITE_NOMEM;
-          db->mallocFailed = 0;
+          rc = SQLITE_NOMEM_BKPT;
           goto btree_open_out;
         }
       }
@@ -49992,12 +60503,12 @@ SQLITE_PRIVATE int sqlite3BtreeOpen(
     for(i=0; i<db->nDb; i++){
       if( (pSib = db->aDb[i].pBt)!=0 && pSib->sharable ){
         while( pSib->pPrev ){ pSib = pSib->pPrev; }
-        if( p->pBt<pSib->pBt ){
+        if( (uptr)p->pBt<(uptr)pSib->pBt ){
           p->pNext = pSib;
           p->pPrev = 0;
           pSib->pPrev = p;
         }else{
-          while( pSib->pNext && pSib->pNext->pBt<p->pBt ){
+          while( pSib->pNext && (uptr)pSib->pNext->pBt<(uptr)p->pBt ){
             pSib = pSib->pNext;
           }
           p->pNext = pSib->pNext;
@@ -50035,6 +60546,7 @@ btree_open_out:
     assert( sqlite3_mutex_held(mutexOpen) );
     sqlite3_mutex_leave(mutexOpen);
   }
+  assert( rc!=SQLITE_OK || sqlite3BtreeConnectionCount(*ppBtree)>0 );
   return rc;
 }
 
@@ -50080,11 +60592,32 @@ static int removeFromSharingList(BtShared *pBt){
 
 /*
 ** Make sure pBt->pTmpSpace points to an allocation of 
-** MX_CELL_SIZE(pBt) bytes.
+** MX_CELL_SIZE(pBt) bytes with a 4-byte prefix for a left-child
+** pointer.
 */
 static void allocateTempSpace(BtShared *pBt){
   if( !pBt->pTmpSpace ){
     pBt->pTmpSpace = sqlite3PageMalloc( pBt->pageSize );
+
+    /* One of the uses of pBt->pTmpSpace is to format cells before
+    ** inserting them into a leaf page (function fillInCell()). If
+    ** a cell is less than 4 bytes in size, it is rounded up to 4 bytes
+    ** by the various routines that manipulate binary cells. Which
+    ** can mean that fillInCell() only initializes the first 2 or 3
+    ** bytes of pTmpSpace, but that the first 4 bytes are copied from
+    ** it into a database page. This is not actually a problem, but it
+    ** does cause a valgrind error when the 1 or 2 bytes of unitialized 
+    ** data is passed to system call write(). So to avoid this error,
+    ** zero the first 4 bytes of temp space here.
+    **
+    ** Also:  Provide four bytes of initialized space before the
+    ** beginning of pTmpSpace as an area available to prepend the
+    ** left-child pointer to the beginning of a cell.
+    */
+    if( pBt->pTmpSpace ){
+      memset(pBt->pTmpSpace, 0, 8);
+      pBt->pTmpSpace += 4;
+    }
   }
 }
 
@@ -50092,8 +60625,11 @@ static void allocateTempSpace(BtShared *pBt){
 ** Free the pBt->pTmpSpace allocation
 */
 static void freeTempSpace(BtShared *pBt){
-  sqlite3PageFree( pBt->pTmpSpace);
-  pBt->pTmpSpace = 0;
+  if( pBt->pTmpSpace ){
+    pBt->pTmpSpace -= 4;
+    sqlite3PageFree(pBt->pTmpSpace);
+    pBt->pTmpSpace = 0;
+  }
 }
 
 /*
@@ -50119,7 +60655,7 @@ SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){
   ** The call to sqlite3BtreeRollback() drops any table-locks held by
   ** this handle.
   */
-  sqlite3BtreeRollback(p);
+  sqlite3BtreeRollback(p, SQLITE_OK, 0);
   sqlite3BtreeLeave(p);
 
   /* If there are still other outstanding references to the shared-btree
@@ -50155,19 +60691,11 @@ SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){
 }
 
 /*
-** Change the limit on the number of pages allowed in the cache.
-**
-** The maximum number of cache pages is set to the absolute
-** value of mxPage.  If mxPage is negative, the pager will
-** operate asynchronously - it will not stop to do fsync()s
-** to insure data is written to the disk surface before
-** continuing.  Transactions still work if synchronous is off,
-** and the database cannot be corrupted if this program
-** crashes.  But if the operating system crashes or there is
-** an abrupt power failure when synchronous is off, the database
-** could be left in an inconsistent and unrecoverable state.
-** Synchronous is on by default so database corruption is not
-** normally a worry.
+** Change the "soft" limit on the number of pages in the cache.
+** Unused and unmodified pages will be recycled when the number of
+** pages in the cache exceeds this soft limit.  But the size of the
+** cache is allowed to grow larger than this limit if it contains
+** dirty pages or pages still in active use.
 */
 SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
   BtShared *pBt = p->pBt;
@@ -50179,6 +60707,41 @@ SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
 }
 
 /*
+** Change the "spill" limit on the number of pages in the cache.
+** If the number of pages exceeds this limit during a write transaction,
+** the pager might attempt to "spill" pages to the journal early in
+** order to free up memory.
+**
+** The value returned is the current spill size.  If zero is passed
+** as an argument, no changes are made to the spill size setting, so
+** using mxPage of 0 is a way to query the current spill size.
+*/
+SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree *p, int mxPage){
+  BtShared *pBt = p->pBt;
+  int res;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  res = sqlite3PagerSetSpillsize(pBt->pPager, mxPage);
+  sqlite3BtreeLeave(p);
+  return res;
+}
+
+#if SQLITE_MAX_MMAP_SIZE>0
+/*
+** Change the limit on the amount of the database file that may be
+** memory mapped.
+*/
+SQLITE_PRIVATE int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){
+  BtShared *pBt = p->pBt;
+  assert( sqlite3_mutex_held(p->db->mutex) );
+  sqlite3BtreeEnter(p);
+  sqlite3PagerSetMmapLimit(pBt->pPager, szMmap);
+  sqlite3BtreeLeave(p);
+  return SQLITE_OK;
+}
+#endif /* SQLITE_MAX_MMAP_SIZE>0 */
+
+/*
 ** Change the way data is synced to disk in order to increase or decrease
 ** how well the database resists damage due to OS crashes and power
 ** failures.  Level 1 is the same as asynchronous (no syncs() occur and
@@ -50187,38 +60750,20 @@ SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
 ** probability of damage to near zero but with a write performance reduction.
 */
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
-SQLITE_PRIVATE int sqlite3BtreeSetSafetyLevel(
+SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(
   Btree *p,              /* The btree to set the safety level on */
-  int level,             /* PRAGMA synchronous.  1=OFF, 2=NORMAL, 3=FULL */
-  int fullSync,          /* PRAGMA fullfsync. */
-  int ckptFullSync       /* PRAGMA checkpoint_fullfync */
+  unsigned pgFlags       /* Various PAGER_* flags */
 ){
   BtShared *pBt = p->pBt;
   assert( sqlite3_mutex_held(p->db->mutex) );
-  assert( level>=1 && level<=3 );
   sqlite3BtreeEnter(p);
-  sqlite3PagerSetSafetyLevel(pBt->pPager, level, fullSync, ckptFullSync);
+  sqlite3PagerSetFlags(pBt->pPager, pgFlags);
   sqlite3BtreeLeave(p);
   return SQLITE_OK;
 }
 #endif
 
 /*
-** Return TRUE if the given btree is set to safety level 1.  In other
-** words, return TRUE if no sync() occurs on the disk files.
-*/
-SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree *p){
-  BtShared *pBt = p->pBt;
-  int rc;
-  assert( sqlite3_mutex_held(p->db->mutex) );  
-  sqlite3BtreeEnter(p);
-  assert( pBt && pBt->pPager );
-  rc = sqlite3PagerNosync(pBt->pPager);
-  sqlite3BtreeLeave(p);
-  return rc;
-}
-
-/*
 ** Change the default pages size and the number of reserved bytes per page.
 ** Or, if the page size has already been fixed, return SQLITE_READONLY 
 ** without changing anything.
@@ -50235,7 +60780,7 @@ SQLITE_PRIVATE int sqlite3BtreeSyncDisabled(Btree *p){
 ** If parameter nReserve is less than zero, then the number of reserved
 ** bytes per page is left unchanged.
 **
-** If the iFix!=0 then the pageSizeFixed flag is set so that the page size
+** If the iFix!=0 then the BTS_PAGESIZE_FIXED flag is set so that the page size
 ** and autovacuum mode can no longer be changed.
 */
 SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
@@ -50243,7 +60788,10 @@ SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve,
   BtShared *pBt = p->pBt;
   assert( nReserve>=-1 && nReserve<=255 );
   sqlite3BtreeEnter(p);
-  if( pBt->pageSizeFixed ){
+#if SQLITE_HAS_CODEC
+  if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;
+#endif
+  if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
     sqlite3BtreeLeave(p);
     return SQLITE_READONLY;
   }
@@ -50254,13 +60802,13 @@ SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve,
   if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
         ((pageSize-1)&pageSize)==0 ){
     assert( (pageSize & 7)==0 );
-    assert( !pBt->pPage1 && !pBt->pCursor );
+    assert( !pBt->pCursor );
     pBt->pageSize = (u32)pageSize;
     freeTempSpace(pBt);
   }
   rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);
   pBt->usableSize = pBt->pageSize - (u16)nReserve;
-  if( iFix ) pBt->pageSizeFixed = 1;
+  if( iFix ) pBt->btsFlags |= BTS_PAGESIZE_FIXED;
   sqlite3BtreeLeave(p);
   return rc;
 }
@@ -50272,20 +60820,45 @@ SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree *p){
   return p->pBt->pageSize;
 }
 
-#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
+/*
+** This function is similar to sqlite3BtreeGetReserve(), except that it
+** may only be called if it is guaranteed that the b-tree mutex is already
+** held.
+**
+** This is useful in one special case in the backup API code where it is
+** known that the shared b-tree mutex is held, but the mutex on the 
+** database handle that owns *p is not. In this case if sqlite3BtreeEnter()
+** were to be called, it might collide with some other operation on the
+** database handle that owns *p, causing undefined behavior.
+*/
+SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p){
+  int n;
+  assert( sqlite3_mutex_held(p->pBt->mutex) );
+  n = p->pBt->pageSize - p->pBt->usableSize;
+  return n;
+}
+
 /*
 ** Return the number of bytes of space at the end of every page that
 ** are intentually left unused.  This is the "reserved" space that is
 ** sometimes used by extensions.
+**
+** If SQLITE_HAS_MUTEX is defined then the number returned is the
+** greater of the current reserved space and the maximum requested
+** reserve space.
 */
-SQLITE_PRIVATE int sqlite3BtreeGetReserve(Btree *p){
+SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree *p){
   int n;
   sqlite3BtreeEnter(p);
-  n = p->pBt->pageSize - p->pBt->usableSize;
+  n = sqlite3BtreeGetReserveNoMutex(p);
+#ifdef SQLITE_HAS_CODEC
+  if( n<p->pBt->optimalReserve ) n = p->pBt->optimalReserve;
+#endif
   sqlite3BtreeLeave(p);
   return n;
 }
 
+
 /*
 ** Set the maximum page count for a database if mxPage is positive.
 ** No changes are made if mxPage is 0 or negative.
@@ -50300,8 +60873,8 @@ SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){
 }
 
 /*
-** Set the secureDelete flag if newFlag is 0 or 1.  If newFlag is -1,
-** then make no changes.  Always return the value of the secureDelete
+** Set the BTS_SECURE_DELETE flag if newFlag is 0 or 1.  If newFlag is -1,
+** then make no changes.  Always return the value of the BTS_SECURE_DELETE
 ** setting after the change.
 */
 SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
@@ -50309,13 +60882,13 @@ SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
   if( p==0 ) return 0;
   sqlite3BtreeEnter(p);
   if( newFlag>=0 ){
-    p->pBt->secureDelete = (newFlag!=0) ? 1 : 0;
+    p->pBt->btsFlags &= ~BTS_SECURE_DELETE;
+    if( newFlag ) p->pBt->btsFlags |= BTS_SECURE_DELETE;
   } 
-  b = p->pBt->secureDelete;
+  b = (p->pBt->btsFlags & BTS_SECURE_DELETE)!=0;
   sqlite3BtreeLeave(p);
   return b;
 }
-#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
 
 /*
 ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
@@ -50332,7 +60905,7 @@ SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *p, int autoVacuum){
   u8 av = (u8)autoVacuum;
 
   sqlite3BtreeEnter(p);
-  if( pBt->pageSizeFixed && (av ?1:0)!=pBt->autoVacuum ){
+  if( (pBt->btsFlags & BTS_PAGESIZE_FIXED)!=0 && (av ?1:0)!=pBt->autoVacuum ){
     rc = SQLITE_READONLY;
   }else{
     pBt->autoVacuum = av ?1:0;
@@ -50400,20 +60973,23 @@ static int lockBtree(BtShared *pBt){
     u32 usableSize;
     u8 *page1 = pPage1->aData;
     rc = SQLITE_NOTADB;
+    /* EVIDENCE-OF: R-43737-39999 Every valid SQLite database file begins
+    ** with the following 16 bytes (in hex): 53 51 4c 69 74 65 20 66 6f 72 6d
+    ** 61 74 20 33 00. */
     if( memcmp(page1, zMagicHeader, 16)!=0 ){
       goto page1_init_failed;
     }
 
 #ifdef SQLITE_OMIT_WAL
     if( page1[18]>1 ){
-      pBt->readOnly = 1;
+      pBt->btsFlags |= BTS_READ_ONLY;
     }
     if( page1[19]>1 ){
       goto page1_init_failed;
     }
 #else
     if( page1[18]>2 ){
-      pBt->readOnly = 1;
+      pBt->btsFlags |= BTS_READ_ONLY;
     }
     if( page1[19]>2 ){
       goto page1_init_failed;
@@ -50427,28 +61003,50 @@ static int lockBtree(BtShared *pBt){
     ** may not be the latest version - there may be a newer one in the log
     ** file.
     */
-    if( page1[19]==2 && pBt->doNotUseWAL==0 ){
+    if( page1[19]==2 && (pBt->btsFlags & BTS_NO_WAL)==0 ){
       int isOpen = 0;
       rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
       if( rc!=SQLITE_OK ){
         goto page1_init_failed;
-      }else if( isOpen==0 ){
-        releasePage(pPage1);
-        return SQLITE_OK;
+      }else{
+#if SQLITE_DEFAULT_SYNCHRONOUS!=SQLITE_DEFAULT_WAL_SYNCHRONOUS
+        sqlite3 *db;
+        Db *pDb;
+        if( (db=pBt->db)!=0 && (pDb=db->aDb)!=0 ){
+          while( pDb->pBt==0 || pDb->pBt->pBt!=pBt ){ pDb++; }
+          if( pDb->bSyncSet==0
+           && pDb->safety_level==SQLITE_DEFAULT_SYNCHRONOUS+1
+          ){
+            pDb->safety_level = SQLITE_DEFAULT_WAL_SYNCHRONOUS+1;
+            sqlite3PagerSetFlags(pBt->pPager,
+               pDb->safety_level | (db->flags & PAGER_FLAGS_MASK));
+          }
+        }
+#endif
+        if( isOpen==0 ){
+          releasePage(pPage1);
+          return SQLITE_OK;
+        }
       }
       rc = SQLITE_NOTADB;
     }
 #endif
 
-    /* The maximum embedded fraction must be exactly 25%.  And the minimum
-    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
+    /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload
+    ** fractions and the leaf payload fraction values must be 64, 32, and 32.
+    **
     ** The original design allowed these amounts to vary, but as of
     ** version 3.6.0, we require them to be fixed.
     */
     if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
       goto page1_init_failed;
     }
+    /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
+    ** determined by the 2-byte integer located at an offset of 16 bytes from
+    ** the beginning of the database file. */
     pageSize = (page1[16]<<8) | (page1[17]<<16);
+    /* EVIDENCE-OF: R-25008-21688 The size of a page is a power of two
+    ** between 512 and 65536 inclusive. */
     if( ((pageSize-1)&pageSize)!=0
      || pageSize>SQLITE_MAX_PAGE_SIZE 
      || pageSize<=256 
@@ -50456,6 +61054,13 @@ static int lockBtree(BtShared *pBt){
       goto page1_init_failed;
     }
     assert( (pageSize & 7)==0 );
+    /* EVIDENCE-OF: R-59310-51205 The "reserved space" size in the 1-byte
+    ** integer at offset 20 is the number of bytes of space at the end of
+    ** each page to reserve for extensions. 
+    **
+    ** EVIDENCE-OF: R-37497-42412 The size of the reserved region is
+    ** determined by the one-byte unsigned integer found at an offset of 20
+    ** into the database file header. */
     usableSize = pageSize - page1[20];
     if( (u32)pageSize!=pBt->pageSize ){
       /* After reading the first page of the database assuming a page size
@@ -50476,6 +61081,9 @@ static int lockBtree(BtShared *pBt){
       rc = SQLITE_CORRUPT_BKPT;
       goto page1_init_failed;
     }
+    /* EVIDENCE-OF: R-28312-64704 However, the usable size is not allowed to
+    ** be less than 480. In other words, if the page size is 512, then the
+    ** reserved space size cannot exceed 32. */
     if( usableSize<480 ){
       goto page1_init_failed;
     }
@@ -50504,6 +61112,11 @@ static int lockBtree(BtShared *pBt){
   pBt->minLocal = (u16)((pBt->usableSize-12)*32/255 - 23);
   pBt->maxLeaf = (u16)(pBt->usableSize - 35);
   pBt->minLeaf = (u16)((pBt->usableSize-12)*32/255 - 23);
+  if( pBt->maxLocal>127 ){
+    pBt->max1bytePayload = 127;
+  }else{
+    pBt->max1bytePayload = (u8)pBt->maxLocal;
+  }
   assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
   pBt->pPage1 = pPage1;
   pBt->nPage = nPage;
@@ -50515,6 +61128,30 @@ page1_init_failed:
   return rc;
 }
 
+#ifndef NDEBUG
+/*
+** Return the number of cursors open on pBt. This is for use
+** in assert() expressions, so it is only compiled if NDEBUG is not
+** defined.
+**
+** Only write cursors are counted if wrOnly is true.  If wrOnly is
+** false then all cursors are counted.
+**
+** For the purposes of this routine, a cursor is any cursor that
+** is capable of reading or writing to the database.  Cursors that
+** have been tripped into the CURSOR_FAULT state are not counted.
+*/
+static int countValidCursors(BtShared *pBt, int wrOnly){
+  BtCursor *pCur;
+  int r = 0;
+  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
+    if( (wrOnly==0 || (pCur->curFlags & BTCF_WriteFlag)!=0)
+     && pCur->eState!=CURSOR_FAULT ) r++; 
+  }
+  return r;
+}
+#endif
+
 /*
 ** If there are no outstanding cursors and we are not in the middle
 ** of a transaction but there is a read lock on the database, then
@@ -50525,13 +61162,13 @@ page1_init_failed:
 */
 static void unlockBtreeIfUnused(BtShared *pBt){
   assert( sqlite3_mutex_held(pBt->mutex) );
-  assert( pBt->pCursor==0 || pBt->inTransaction>TRANS_NONE );
+  assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE );
   if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){
-    assert( pBt->pPage1->aData );
+    MemPage *pPage1 = pBt->pPage1;
+    assert( pPage1->aData );
     assert( sqlite3PagerRefcount(pBt->pPager)==1 );
-    assert( pBt->pPage1->aData );
-    releasePage(pBt->pPage1);
     pBt->pPage1 = 0;
+    releasePageNotNull(pPage1);
   }
 }
 
@@ -50567,7 +61204,7 @@ static int newDatabase(BtShared *pBt){
   data[23] = 32;
   memset(&data[24], 0, 100-24);
   zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
-  pBt->pageSizeFixed = 1;
+  pBt->btsFlags |= BTS_PAGESIZE_FIXED;
 #ifndef SQLITE_OMIT_AUTOVACUUM
   assert( pBt->autoVacuum==1 || pBt->autoVacuum==0 );
   assert( pBt->incrVacuum==1 || pBt->incrVacuum==0 );
@@ -50580,6 +61217,20 @@ static int newDatabase(BtShared *pBt){
 }
 
 /*
+** Initialize the first page of the database file (creating a database
+** consisting of a single page and no schema objects). Return SQLITE_OK
+** if successful, or an SQLite error code otherwise.
+*/
+SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p){
+  int rc;
+  sqlite3BtreeEnter(p);
+  p->pBt->nPage = 0;
+  rc = newDatabase(p->pBt);
+  sqlite3BtreeLeave(p);
+  return rc;
+}
+
+/*
 ** Attempt to start a new transaction. A write-transaction
 ** is started if the second argument is nonzero, otherwise a read-
 ** transaction.  If the second argument is 2 or more and exclusive
@@ -50615,7 +61266,6 @@ static int newDatabase(BtShared *pBt){
 ** proceed.
 */
 SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
-  sqlite3 *pBlock = 0;
   BtShared *pBt = p->pBt;
   int rc = SQLITE_OK;
 
@@ -50629,33 +61279,39 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
   if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){
     goto trans_begun;
   }
+  assert( pBt->inTransaction==TRANS_WRITE || IfNotOmitAV(pBt->bDoTruncate)==0 );
 
   /* Write transactions are not possible on a read-only database */
-  if( pBt->readOnly && wrflag ){
+  if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){
     rc = SQLITE_READONLY;
     goto trans_begun;
   }
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
-  /* If another database handle has already opened a write transaction 
-  ** on this shared-btree structure and a second write transaction is
-  ** requested, return SQLITE_LOCKED.
-  */
-  if( (wrflag && pBt->inTransaction==TRANS_WRITE) || pBt->isPending ){
-    pBlock = pBt->pWriter->db;
-  }else if( wrflag>1 ){
-    BtLock *pIter;
-    for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
-      if( pIter->pBtree!=p ){
-        pBlock = pIter->pBtree->db;
-        break;
+  {
+    sqlite3 *pBlock = 0;
+    /* If another database handle has already opened a write transaction 
+    ** on this shared-btree structure and a second write transaction is
+    ** requested, return SQLITE_LOCKED.
+    */
+    if( (wrflag && pBt->inTransaction==TRANS_WRITE)
+     || (pBt->btsFlags & BTS_PENDING)!=0
+    ){
+      pBlock = pBt->pWriter->db;
+    }else if( wrflag>1 ){
+      BtLock *pIter;
+      for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){
+        if( pIter->pBtree!=p ){
+          pBlock = pIter->pBtree->db;
+          break;
+        }
       }
     }
-  }
-  if( pBlock ){
-    sqlite3ConnectionBlocked(p->db, pBlock);
-    rc = SQLITE_LOCKED_SHAREDCACHE;
-    goto trans_begun;
+    if( pBlock ){
+      sqlite3ConnectionBlocked(p->db, pBlock);
+      rc = SQLITE_LOCKED_SHAREDCACHE;
+      goto trans_begun;
+    }
   }
 #endif
 
@@ -50665,7 +61321,8 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
   rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);
   if( SQLITE_OK!=rc ) goto trans_begun;
 
-  pBt->initiallyEmpty = (u8)(pBt->nPage==0);
+  pBt->btsFlags &= ~BTS_INITIALLY_EMPTY;
+  if( pBt->nPage==0 ) pBt->btsFlags |= BTS_INITIALLY_EMPTY;
   do {
     /* Call lockBtree() until either pBt->pPage1 is populated or
     ** lockBtree() returns something other than SQLITE_OK. lockBtree()
@@ -50677,7 +61334,7 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
     while( pBt->pPage1==0 && SQLITE_OK==(rc = lockBtree(pBt)) );
 
     if( rc==SQLITE_OK && wrflag ){
-      if( pBt->readOnly ){
+      if( (pBt->btsFlags & BTS_READ_ONLY)!=0 ){
         rc = SQLITE_READONLY;
       }else{
         rc = sqlite3PagerBegin(pBt->pPager,wrflag>1,sqlite3TempInMemory(p->db));
@@ -50698,7 +61355,7 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
       pBt->nTransaction++;
 #ifndef SQLITE_OMIT_SHARED_CACHE
       if( p->sharable ){
-	assert( p->lock.pBtree==p && p->lock.iTable==1 );
+        assert( p->lock.pBtree==p && p->lock.iTable==1 );
         p->lock.eLock = READ_LOCK;
         p->lock.pNext = pBt->pLock;
         pBt->pLock = &p->lock;
@@ -50714,7 +61371,8 @@ SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
 #ifndef SQLITE_OMIT_SHARED_CACHE
       assert( !pBt->pWriter );
       pBt->pWriter = p;
-      pBt->isExclusive = (u8)(wrflag>1);
+      pBt->btsFlags &= ~BTS_EXCLUSIVE;
+      if( wrflag>1 ) pBt->btsFlags |= BTS_EXCLUSIVE;
 #endif
 
       /* If the db-size header field is incorrect (as it may be if an old
@@ -50817,20 +61475,22 @@ static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
     u8 isInitOrig = pPage->isInit;
     int i;
     int nCell;
+    int rc;
 
-    btreeInitPage(pPage);
+    rc = btreeInitPage(pPage);
+    if( rc ) return rc;
     nCell = pPage->nCell;
 
     for(i=0; i<nCell; i++){
       u8 *pCell = findCell(pPage, i);
       if( eType==PTRMAP_OVERFLOW1 ){
         CellInfo info;
-        btreeParseCellPtr(pPage, pCell, &info);
-        if( info.iOverflow
-         && pCell+info.iOverflow+3<=pPage->aData+pPage->maskPage
-         && iFrom==get4byte(&pCell[info.iOverflow])
+        pPage->xParseCell(pPage, pCell, &info);
+        if( info.nLocal<info.nPayload
+         && pCell+info.nSize-1<=pPage->aData+pPage->maskPage
+         && iFrom==get4byte(pCell+info.nSize-4)
         ){
-          put4byte(&pCell[info.iOverflow], iTo);
+          put4byte(pCell+info.nSize-4, iTo);
           break;
         }
       }else{
@@ -50941,24 +61601,23 @@ static int relocatePage(
 static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);
 
 /*
-** Perform a single step of an incremental-vacuum. If successful,
-** return SQLITE_OK. If there is no work to do (and therefore no
-** point in calling this function again), return SQLITE_DONE.
+** Perform a single step of an incremental-vacuum. If successful, return
+** SQLITE_OK. If there is no work to do (and therefore no point in 
+** calling this function again), return SQLITE_DONE. Or, if an error 
+** occurs, return some other error code.
 **
-** More specificly, this function attempts to re-organize the 
-** database so that the last page of the file currently in use
-** is no longer in use.
+** More specifically, this function attempts to re-organize the database so 
+** that the last page of the file currently in use is no longer in use.
 **
-** If the nFin parameter is non-zero, this function assumes
-** that the caller will keep calling incrVacuumStep() until
-** it returns SQLITE_DONE or an error, and that nFin is the
-** number of pages the database file will contain after this 
-** process is complete.  If nFin is zero, it is assumed that
-** incrVacuumStep() will be called a finite amount of times
-** which may or may not empty the freelist.  A full autovacuum
-** has nFin>0.  A "PRAGMA incremental_vacuum" has nFin==0.
+** Parameter nFin is the number of pages that this database would contain
+** were this function called until it returns SQLITE_DONE.
+**
+** If the bCommit parameter is non-zero, this function assumes that the 
+** caller will keep calling incrVacuumStep() until it returns SQLITE_DONE 
+** or an error. bCommit is passed true for an auto-vacuum-on-commit 
+** operation, or false for an incremental vacuum.
 */
-static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
+static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){
   Pgno nFreeList;           /* Number of pages still on the free-list */
   int rc;
 
@@ -50983,15 +61642,15 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     }
 
     if( eType==PTRMAP_FREEPAGE ){
-      if( nFin==0 ){
+      if( bCommit==0 ){
         /* Remove the page from the files free-list. This is not required
-        ** if nFin is non-zero. In that case, the free-list will be
+        ** if bCommit is non-zero. In that case, the free-list will be
         ** truncated to zero after this function returns, so it doesn't 
         ** matter if it still contains some garbage entries.
         */
         Pgno iFreePg;
         MemPage *pFreePg;
-        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, 1);
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, BTALLOC_EXACT);
         if( rc!=SQLITE_OK ){
           return rc;
         }
@@ -51001,34 +61660,37 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     } else {
       Pgno iFreePg;             /* Index of free page to move pLastPg to */
       MemPage *pLastPg;
+      u8 eMode = BTALLOC_ANY;   /* Mode parameter for allocateBtreePage() */
+      Pgno iNear = 0;           /* nearby parameter for allocateBtreePage() */
 
       rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
 
-      /* If nFin is zero, this loop runs exactly once and page pLastPg
+      /* If bCommit is zero, this loop runs exactly once and page pLastPg
       ** is swapped with the first free page pulled off the free list.
       **
-      ** On the other hand, if nFin is greater than zero, then keep
+      ** On the other hand, if bCommit is greater than zero, then keep
       ** looping until a free-page located within the first nFin pages
       ** of the file is found.
       */
+      if( bCommit==0 ){
+        eMode = BTALLOC_LE;
+        iNear = nFin;
+      }
       do {
         MemPage *pFreePg;
-        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, 0, 0);
+        rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iNear, eMode);
         if( rc!=SQLITE_OK ){
           releasePage(pLastPg);
           return rc;
         }
         releasePage(pFreePg);
-      }while( nFin!=0 && iFreePg>nFin );
+      }while( bCommit && iFreePg>nFin );
       assert( iFreePg<iLastPg );
       
-      rc = sqlite3PagerWrite(pLastPg->pDbPage);
-      if( rc==SQLITE_OK ){
-        rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, nFin!=0);
-      }
+      rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, bCommit);
       releasePage(pLastPg);
       if( rc!=SQLITE_OK ){
         return rc;
@@ -51036,30 +61698,40 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
     }
   }
 
-  if( nFin==0 ){
-    iLastPg--;
-    while( iLastPg==PENDING_BYTE_PAGE(pBt)||PTRMAP_ISPAGE(pBt, iLastPg) ){
-      if( PTRMAP_ISPAGE(pBt, iLastPg) ){
-        MemPage *pPg;
-        rc = btreeGetPage(pBt, iLastPg, &pPg, 0);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        rc = sqlite3PagerWrite(pPg->pDbPage);
-        releasePage(pPg);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-      }
+  if( bCommit==0 ){
+    do {
       iLastPg--;
-    }
-    sqlite3PagerTruncateImage(pBt->pPager, iLastPg);
+    }while( iLastPg==PENDING_BYTE_PAGE(pBt) || PTRMAP_ISPAGE(pBt, iLastPg) );
+    pBt->bDoTruncate = 1;
     pBt->nPage = iLastPg;
   }
   return SQLITE_OK;
 }
 
 /*
+** The database opened by the first argument is an auto-vacuum database
+** nOrig pages in size containing nFree free pages. Return the expected 
+** size of the database in pages following an auto-vacuum operation.
+*/
+static Pgno finalDbSize(BtShared *pBt, Pgno nOrig, Pgno nFree){
+  int nEntry;                     /* Number of entries on one ptrmap page */
+  Pgno nPtrmap;                   /* Number of PtrMap pages to be freed */
+  Pgno nFin;                      /* Return value */
+
+  nEntry = pBt->usableSize/5;
+  nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;
+  nFin = nOrig - nFree - nPtrmap;
+  if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){
+    nFin--;
+  }
+  while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){
+    nFin--;
+  }
+
+  return nFin;
+}
+
+/*
 ** A write-transaction must be opened before calling this function.
 ** It performs a single unit of work towards an incremental vacuum.
 **
@@ -51076,11 +61748,24 @@ SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *p){
   if( !pBt->autoVacuum ){
     rc = SQLITE_DONE;
   }else{
-    invalidateAllOverflowCache(pBt);
-    rc = incrVacuumStep(pBt, 0, btreePagecount(pBt));
-    if( rc==SQLITE_OK ){
-      rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
-      put4byte(&pBt->pPage1->aData[28], pBt->nPage);
+    Pgno nOrig = btreePagecount(pBt);
+    Pgno nFree = get4byte(&pBt->pPage1->aData[36]);
+    Pgno nFin = finalDbSize(pBt, nOrig, nFree);
+
+    if( nOrig<nFin ){
+      rc = SQLITE_CORRUPT_BKPT;
+    }else if( nFree>0 ){
+      rc = saveAllCursors(pBt, 0, 0);
+      if( rc==SQLITE_OK ){
+        invalidateAllOverflowCache(pBt);
+        rc = incrVacuumStep(pBt, nFin, nOrig, 0);
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
+        put4byte(&pBt->pPage1->aData[28], pBt->nPage);
+      }
+    }else{
+      rc = SQLITE_DONE;
     }
   }
   sqlite3BtreeLeave(p);
@@ -51089,7 +61774,7 @@ SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *p){
 
 /*
 ** This routine is called prior to sqlite3PagerCommit when a transaction
-** is commited for an auto-vacuum database.
+** is committed for an auto-vacuum database.
 **
 ** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages
 ** the database file should be truncated to during the commit process. 
@@ -51099,7 +61784,7 @@ SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *p){
 static int autoVacuumCommit(BtShared *pBt){
   int rc = SQLITE_OK;
   Pager *pPager = pBt->pPager;
-  VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager) );
+  VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager); )
 
   assert( sqlite3_mutex_held(pBt->mutex) );
   invalidateAllOverflowCache(pBt);
@@ -51107,9 +61792,7 @@ static int autoVacuumCommit(BtShared *pBt){
   if( !pBt->incrVacuum ){
     Pgno nFin;         /* Number of pages in database after autovacuuming */
     Pgno nFree;        /* Number of pages on the freelist initially */
-    Pgno nPtrmap;      /* Number of PtrMap pages to be freed */
     Pgno iFree;        /* The next page to be freed */
-    int nEntry;        /* Number of entries on one ptrmap page */
     Pgno nOrig;        /* Database size before freeing */
 
     nOrig = btreePagecount(pBt);
@@ -51122,26 +61805,20 @@ static int autoVacuumCommit(BtShared *pBt){
     }
 
     nFree = get4byte(&pBt->pPage1->aData[36]);
-    nEntry = pBt->usableSize/5;
-    nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;
-    nFin = nOrig - nFree - nPtrmap;
-    if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){
-      nFin--;
-    }
-    while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){
-      nFin--;
-    }
+    nFin = finalDbSize(pBt, nOrig, nFree);
     if( nFin>nOrig ) return SQLITE_CORRUPT_BKPT;
-
+    if( nFin<nOrig ){
+      rc = saveAllCursors(pBt, 0, 0);
+    }
     for(iFree=nOrig; iFree>nFin && rc==SQLITE_OK; iFree--){
-      rc = incrVacuumStep(pBt, nFin, iFree);
+      rc = incrVacuumStep(pBt, nFin, iFree, 1);
     }
     if( (rc==SQLITE_DONE || rc==SQLITE_OK) && nFree>0 ){
       rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
       put4byte(&pBt->pPage1->aData[32], 0);
       put4byte(&pBt->pPage1->aData[36], 0);
       put4byte(&pBt->pPage1->aData[28], nFin);
-      sqlite3PagerTruncateImage(pBt->pPager, nFin);
+      pBt->bDoTruncate = 1;
       pBt->nPage = nFin;
     }
     if( rc!=SQLITE_OK ){
@@ -51149,7 +61826,7 @@ static int autoVacuumCommit(BtShared *pBt){
     }
   }
 
-  assert( nRef==sqlite3PagerRefcount(pPager) );
+  assert( nRef>=sqlite3PagerRefcount(pPager) );
   return rc;
 }
 
@@ -51196,6 +61873,9 @@ SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){
         return rc;
       }
     }
+    if( pBt->bDoTruncate ){
+      sqlite3PagerTruncateImage(pBt->pPager, pBt->nPage);
+    }
 #endif
     rc = sqlite3PagerCommitPhaseOne(pBt->pPager, zMaster, 0);
     sqlite3BtreeLeave(p);
@@ -51209,10 +61889,13 @@ SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){
 */
 static void btreeEndTransaction(Btree *p){
   BtShared *pBt = p->pBt;
+  sqlite3 *db = p->db;
   assert( sqlite3BtreeHoldsMutex(p) );
 
-  btreeClearHasContent(pBt);
-  if( p->inTrans>TRANS_NONE && p->db->activeVdbeCnt>1 ){
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  pBt->bDoTruncate = 0;
+#endif
+  if( p->inTrans>TRANS_NONE && db->nVdbeRead>1 ){
     /* If there are other active statements that belong to this database
     ** handle, downgrade to a read-only transaction. The other statements
     ** may still be reading from the database.  */
@@ -51285,7 +61968,9 @@ SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){
       sqlite3BtreeLeave(p);
       return rc;
     }
+    p->iDataVersion--;  /* Compensate for pPager->iDataVersion++; */
     pBt->inTransaction = TRANS_READ;
+    btreeClearHasContent(pBt);
   }
 
   btreeEndTransaction(p);
@@ -51307,88 +61992,94 @@ SQLITE_PRIVATE int sqlite3BtreeCommit(Btree *p){
   return rc;
 }
 
-#ifndef NDEBUG
-/*
-** Return the number of write-cursors open on this handle. This is for use
-** in assert() expressions, so it is only compiled if NDEBUG is not
-** defined.
-**
-** For the purposes of this routine, a write-cursor is any cursor that
-** is capable of writing to the databse.  That means the cursor was
-** originally opened for writing and the cursor has not be disabled
-** by having its state changed to CURSOR_FAULT.
-*/
-static int countWriteCursors(BtShared *pBt){
-  BtCursor *pCur;
-  int r = 0;
-  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
-    if( pCur->wrFlag && pCur->eState!=CURSOR_FAULT ) r++; 
-  }
-  return r;
-}
-#endif
-
 /*
 ** This routine sets the state to CURSOR_FAULT and the error
-** code to errCode for every cursor on BtShared that pBtree
-** references.
-**
-** Every cursor is tripped, including cursors that belong
-** to other database connections that happen to be sharing
-** the cache with pBtree.
-**
-** This routine gets called when a rollback occurs.
-** All cursors using the same cache must be tripped
-** to prevent them from trying to use the btree after
-** the rollback.  The rollback may have deleted tables
-** or moved root pages, so it is not sufficient to
-** save the state of the cursor.  The cursor must be
-** invalidated.
-*/
-SQLITE_PRIVATE void sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode){
+** code to errCode for every cursor on any BtShared that pBtree
+** references.  Or if the writeOnly flag is set to 1, then only
+** trip write cursors and leave read cursors unchanged.
+**
+** Every cursor is a candidate to be tripped, including cursors
+** that belong to other database connections that happen to be
+** sharing the cache with pBtree.
+**
+** This routine gets called when a rollback occurs. If the writeOnly
+** flag is true, then only write-cursors need be tripped - read-only
+** cursors save their current positions so that they may continue 
+** following the rollback. Or, if writeOnly is false, all cursors are 
+** tripped. In general, writeOnly is false if the transaction being
+** rolled back modified the database schema. In this case b-tree root
+** pages may be moved or deleted from the database altogether, making
+** it unsafe for read cursors to continue.
+**
+** If the writeOnly flag is true and an error is encountered while 
+** saving the current position of a read-only cursor, all cursors, 
+** including all read-cursors are tripped.
+**
+** SQLITE_OK is returned if successful, or if an error occurs while
+** saving a cursor position, an SQLite error code.
+*/
+SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int writeOnly){
   BtCursor *p;
-  sqlite3BtreeEnter(pBtree);
-  for(p=pBtree->pBt->pCursor; p; p=p->pNext){
-    int i;
-    sqlite3BtreeClearCursor(p);
-    p->eState = CURSOR_FAULT;
-    p->skipNext = errCode;
-    for(i=0; i<=p->iPage; i++){
-      releasePage(p->apPage[i]);
-      p->apPage[i] = 0;
+  int rc = SQLITE_OK;
+
+  assert( (writeOnly==0 || writeOnly==1) && BTCF_WriteFlag==1 );
+  if( pBtree ){
+    sqlite3BtreeEnter(pBtree);
+    for(p=pBtree->pBt->pCursor; p; p=p->pNext){
+      int i;
+      if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){
+        if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
+          rc = saveCursorPosition(p);
+          if( rc!=SQLITE_OK ){
+            (void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);
+            break;
+          }
+        }
+      }else{
+        sqlite3BtreeClearCursor(p);
+        p->eState = CURSOR_FAULT;
+        p->skipNext = errCode;
+      }
+      for(i=0; i<=p->iPage; i++){
+        releasePage(p->apPage[i]);
+        p->apPage[i] = 0;
+      }
     }
+    sqlite3BtreeLeave(pBtree);
   }
-  sqlite3BtreeLeave(pBtree);
+  return rc;
 }
 
 /*
-** Rollback the transaction in progress.  All cursors will be
-** invalided by this operation.  Any attempt to use a cursor
-** that was open at the beginning of this operation will result
-** in an error.
+** Rollback the transaction in progress.
+**
+** If tripCode is not SQLITE_OK then cursors will be invalidated (tripped).
+** Only write cursors are tripped if writeOnly is true but all cursors are
+** tripped if writeOnly is false.  Any attempt to use
+** a tripped cursor will result in an error.
 **
 ** This will release the write lock on the database file.  If there
 ** are no active cursors, it also releases the read lock.
 */
-SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p){
+SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p, int tripCode, int writeOnly){
   int rc;
   BtShared *pBt = p->pBt;
   MemPage *pPage1;
 
+  assert( writeOnly==1 || writeOnly==0 );
+  assert( tripCode==SQLITE_ABORT_ROLLBACK || tripCode==SQLITE_OK );
   sqlite3BtreeEnter(p);
-  rc = saveAllCursors(pBt, 0, 0);
-#ifndef SQLITE_OMIT_SHARED_CACHE
-  if( rc!=SQLITE_OK ){
-    /* This is a horrible situation. An IO or malloc() error occurred whilst
-    ** trying to save cursor positions. If this is an automatic rollback (as
-    ** the result of a constraint, malloc() failure or IO error) then 
-    ** the cache may be internally inconsistent (not contain valid trees) so
-    ** we cannot simply return the error to the caller. Instead, abort 
-    ** all queries that may be using any of the cursors that failed to save.
-    */
-    sqlite3BtreeTripAllCursors(p, rc);
+  if( tripCode==SQLITE_OK ){
+    rc = tripCode = saveAllCursors(pBt, 0, 0);
+    if( rc ) writeOnly = 0;
+  }else{
+    rc = SQLITE_OK;
+  }
+  if( tripCode ){
+    int rc2 = sqlite3BtreeTripAllCursors(p, tripCode, writeOnly);
+    assert( rc==SQLITE_OK || (writeOnly==0 && rc2==SQLITE_OK) );
+    if( rc2!=SQLITE_OK ) rc = rc2;
   }
-#endif
   btreeIntegrity(p);
 
   if( p->inTrans==TRANS_WRITE ){
@@ -51411,8 +62102,9 @@ SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p){
       pBt->nPage = nPage;
       releasePage(pPage1);
     }
-    assert( countWriteCursors(pBt)==0 );
+    assert( countValidCursors(pBt, 1)==0 );
     pBt->inTransaction = TRANS_READ;
+    btreeClearHasContent(pBt);
   }
 
   btreeEndTransaction(p);
@@ -51421,7 +62113,7 @@ SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p){
 }
 
 /*
-** Start a statement subtransaction. The subtransaction can can be rolled
+** Start a statement subtransaction. The subtransaction can be rolled
 ** back independently of the main transaction. You must start a transaction 
 ** before starting a subtransaction. The subtransaction is ended automatically 
 ** if the main transaction commits or rolls back.
@@ -51443,7 +62135,7 @@ SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree *p, int iStatement){
   BtShared *pBt = p->pBt;
   sqlite3BtreeEnter(p);
   assert( p->inTrans==TRANS_WRITE );
-  assert( pBt->readOnly==0 );
+  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
   assert( iStatement>0 );
   assert( iStatement>p->db->nSavepoint );
   assert( pBt->inTransaction==TRANS_WRITE );
@@ -51478,7 +62170,9 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
     sqlite3BtreeEnter(p);
     rc = sqlite3PagerSavepoint(pBt->pPager, op, iSavepoint);
     if( rc==SQLITE_OK ){
-      if( iSavepoint<0 && pBt->initiallyEmpty ) pBt->nPage = 0;
+      if( iSavepoint<0 && (pBt->btsFlags & BTS_INITIALLY_EMPTY)!=0 ){
+        pBt->nPage = 0;
+      }
       rc = newDatabase(pBt);
       pBt->nPage = get4byte(28 + pBt->pPage1->aData);
 
@@ -51499,13 +62193,13 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
 ** on the database already. If a write-cursor is requested, then
 ** the caller is assumed to have an open write transaction.
 **
-** If wrFlag==0, then the cursor can only be used for reading.
-** If wrFlag==1, then the cursor can be used for reading or for
-** writing if other conditions for writing are also met.  These
-** are the conditions that must be met in order for writing to
-** be allowed:
+** If the BTREE_WRCSR bit of wrFlag is clear, then the cursor can only
+** be used for reading.  If the BTREE_WRCSR bit is set, then the cursor
+** can be used for reading or for writing if other conditions for writing
+** are also met.  These are the conditions that must be met in order
+** for writing to be allowed:
 **
-** 1:  The cursor must have been opened with wrFlag==1
+** 1:  The cursor must have been opened with wrFlag containing BTREE_WRCSR
 **
 ** 2:  Other database connections that share the same pager cache
 **     but which are not in the READ_UNCOMMITTED state may not have
@@ -51517,6 +62211,16 @@ SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){
 **
 ** 4:  There must be an active transaction.
 **
+** The BTREE_FORDELETE bit of wrFlag may optionally be set if BTREE_WRCSR
+** is set.  If FORDELETE is set, that is a hint to the implementation that
+** this cursor will only be used to seek to and delete entries of an index
+** as part of a larger DELETE statement.  The FORDELETE hint is not used by
+** this implementation.  But in a hypothetical alternative storage engine 
+** in which index entries are automatically deleted when corresponding table
+** rows are deleted, the FORDELETE flag is a hint that all SEEK and DELETE
+** operations on this cursor can be no-ops and all READ operations can 
+** return a null row (2-bytes: 0x01 0x00).
+**
 ** No checking is done to make sure that page iTable really is the
 ** root page of a b-tree.  If it is not, then the cursor acquired
 ** will not work correctly.
@@ -51532,24 +62236,30 @@ static int btreeCursor(
   BtCursor *pCur                         /* Space for new cursor */
 ){
   BtShared *pBt = p->pBt;                /* Shared b-tree handle */
+  BtCursor *pX;                          /* Looping over other all cursors */
 
   assert( sqlite3BtreeHoldsMutex(p) );
-  assert( wrFlag==0 || wrFlag==1 );
+  assert( wrFlag==0 
+       || wrFlag==BTREE_WRCSR 
+       || wrFlag==(BTREE_WRCSR|BTREE_FORDELETE) 
+  );
 
   /* The following assert statements verify that if this is a sharable 
   ** b-tree database, the connection is holding the required table locks, 
   ** and that no other connection has any open cursor that conflicts with 
   ** this lock.  */
-  assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, wrFlag+1) );
+  assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, (wrFlag?2:1)) );
   assert( wrFlag==0 || !hasReadConflicts(p, iTable) );
 
   /* Assert that the caller has opened the required transaction. */
   assert( p->inTrans>TRANS_NONE );
   assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
   assert( pBt->pPage1 && pBt->pPage1->aData );
+  assert( wrFlag==0 || (pBt->btsFlags & BTS_READ_ONLY)==0 );
 
-  if( NEVER(wrFlag && pBt->readOnly) ){
-    return SQLITE_READONLY;
+  if( wrFlag ){
+    allocateTempSpace(pBt);
+    if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM_BKPT;
   }
   if( iTable==1 && btreePagecount(pBt)==0 ){
     assert( wrFlag==0 );
@@ -51563,14 +62273,19 @@ static int btreeCursor(
   pCur->pKeyInfo = pKeyInfo;
   pCur->pBtree = p;
   pCur->pBt = pBt;
-  pCur->wrFlag = (u8)wrFlag;
-  pCur->pNext = pBt->pCursor;
-  if( pCur->pNext ){
-    pCur->pNext->pPrev = pCur;
+  pCur->curFlags = wrFlag ? BTCF_WriteFlag : 0;
+  pCur->curPagerFlags = wrFlag ? 0 : PAGER_GET_READONLY;
+  /* If there are two or more cursors on the same btree, then all such
+  ** cursors *must* have the BTCF_Multiple flag set. */
+  for(pX=pBt->pCursor; pX; pX=pX->pNext){
+    if( pX->pgnoRoot==(Pgno)iTable ){
+      pX->curFlags |= BTCF_Multiple;
+      pCur->curFlags |= BTCF_Multiple;
+    }
   }
+  pCur->pNext = pBt->pCursor;
   pBt->pCursor = pCur;
   pCur->eState = CURSOR_INVALID;
-  pCur->cachedRowid = 0;
   return SQLITE_OK;
 }
 SQLITE_PRIVATE int sqlite3BtreeCursor(
@@ -51581,9 +62296,13 @@ SQLITE_PRIVATE int sqlite3BtreeCursor(
   BtCursor *pCur                              /* Write new cursor here */
 ){
   int rc;
-  sqlite3BtreeEnter(p);
-  rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
-  sqlite3BtreeLeave(p);
+  if( iTable<1 ){
+    rc = SQLITE_CORRUPT_BKPT;
+  }else{
+    sqlite3BtreeEnter(p);
+    rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
+    sqlite3BtreeLeave(p);
+  }
   return rc;
 }
 
@@ -51612,36 +62331,6 @@ SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor *p){
 }
 
 /*
-** Set the cached rowid value of every cursor in the same database file
-** as pCur and having the same root page number as pCur.  The value is
-** set to iRowid.
-**
-** Only positive rowid values are considered valid for this cache.
-** The cache is initialized to zero, indicating an invalid cache.
-** A btree will work fine with zero or negative rowids.  We just cannot
-** cache zero or negative rowids, which means tables that use zero or
-** negative rowids might run a little slower.  But in practice, zero
-** or negative rowids are very uncommon so this should not be a problem.
-*/
-SQLITE_PRIVATE void sqlite3BtreeSetCachedRowid(BtCursor *pCur, sqlite3_int64 iRowid){
-  BtCursor *p;
-  for(p=pCur->pBt->pCursor; p; p=p->pNext){
-    if( p->pgnoRoot==pCur->pgnoRoot ) p->cachedRowid = iRowid;
-  }
-  assert( pCur->cachedRowid==iRowid );
-}
-
-/*
-** Return the cached rowid for the given cursor.  A negative or zero
-** return value indicates that the rowid cache is invalid and should be
-** ignored.  If the rowid cache has never before been set, then a
-** zero is returned.
-*/
-SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeGetCachedRowid(BtCursor *pCur){
-  return pCur->cachedRowid;
-}
-
-/*
 ** Close a cursor.  The read lock on the database file is released
 ** when the last cursor is closed.
 */
@@ -51652,19 +62341,24 @@ SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
     BtShared *pBt = pCur->pBt;
     sqlite3BtreeEnter(pBtree);
     sqlite3BtreeClearCursor(pCur);
-    if( pCur->pPrev ){
-      pCur->pPrev->pNext = pCur->pNext;
-    }else{
+    assert( pBt->pCursor!=0 );
+    if( pBt->pCursor==pCur ){
       pBt->pCursor = pCur->pNext;
-    }
-    if( pCur->pNext ){
-      pCur->pNext->pPrev = pCur->pPrev;
+    }else{
+      BtCursor *pPrev = pBt->pCursor;
+      do{
+        if( pPrev->pNext==pCur ){
+          pPrev->pNext = pCur->pNext;
+          break;
+        }
+        pPrev = pPrev->pNext;
+      }while( ALWAYS(pPrev) );
     }
     for(i=0; i<=pCur->iPage; i++){
       releasePage(pCur->apPage[i]);
     }
     unlockBtreeIfUnused(pBt);
-    invalidateOverflowCache(pCur);
+    sqlite3_free(pCur->aOverflow);
     /* sqlite3_free(pCur); */
     sqlite3BtreeLeave(pBtree);
   }
@@ -51678,13 +62372,6 @@ SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
 **
 ** BtCursor.info is a cache of the information in the current cell.
 ** Using this cache reduces the number of calls to btreeParseCell().
-**
-** 2007-06-25:  There is a bug in some versions of MSVC that cause the
-** compiler to crash when getCellInfo() is implemented as a macro.
-** But there is a measureable speed advantage to using the macro on gcc
-** (when less compiler optimizations like -Os or -O0 are used and the
-** compiler is not doing agressive inlining.)  So we use a real function
-** for MSVC and a macro for everything else.  Ticket #2457.
 */
 #ifndef NDEBUG
   static void assertCellInfo(BtCursor *pCur){
@@ -51692,33 +62379,20 @@ SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){
     int iPage = pCur->iPage;
     memset(&info, 0, sizeof(info));
     btreeParseCell(pCur->apPage[iPage], pCur->aiIdx[iPage], &info);
-    assert( memcmp(&info, &pCur->info, sizeof(info))==0 );
+    assert( CORRUPT_DB || memcmp(&info, &pCur->info, sizeof(info))==0 );
   }
 #else
   #define assertCellInfo(x)
 #endif
-#ifdef _MSC_VER
-  /* Use a real function in MSVC to work around bugs in that compiler. */
-  static void getCellInfo(BtCursor *pCur){
-    if( pCur->info.nSize==0 ){
-      int iPage = pCur->iPage;
-      btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
-      pCur->validNKey = 1;
-    }else{
-      assertCellInfo(pCur);
-    }
-  }
-#else /* if not _MSC_VER */
-  /* Use a macro in all other compilers so that the function is inlined */
-#define getCellInfo(pCur)                                                      \
-  if( pCur->info.nSize==0 ){                                                   \
-    int iPage = pCur->iPage;                                                   \
-    btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info); \
-    pCur->validNKey = 1;                                                       \
-  }else{                                                                       \
-    assertCellInfo(pCur);                                                      \
+static SQLITE_NOINLINE void getCellInfo(BtCursor *pCur){
+  if( pCur->info.nSize==0 ){
+    int iPage = pCur->iPage;
+    pCur->curFlags |= BTCF_ValidNKey;
+    btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
+  }else{
+    assertCellInfo(pCur);
   }
-#endif /* _MSC_VER */
+}
 
 #ifndef NDEBUG  /* The next routine used only within assert() statements */
 /*
@@ -51732,47 +62406,33 @@ SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor *pCur){
 #endif /* NDEBUG */
 
 /*
-** Set *pSize to the size of the buffer needed to hold the value of
-** the key for the current entry.  If the cursor is not pointing
-** to a valid entry, *pSize is set to 0. 
-**
-** For a table with the INTKEY flag set, this routine returns the key
-** itself, not the number of bytes in the key.
-**
-** The caller must position the cursor prior to invoking this routine.
-** 
-** This routine cannot fail.  It always returns SQLITE_OK.  
+** Return the value of the integer key or "rowid" for a table btree.
+** This routine is only valid for a cursor that is pointing into a
+** ordinary table btree.  If the cursor points to an index btree or
+** is invalid, the result of this routine is undefined.
 */
-SQLITE_PRIVATE int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
+SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor *pCur){
   assert( cursorHoldsMutex(pCur) );
-  assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
-  if( pCur->eState!=CURSOR_VALID ){
-    *pSize = 0;
-  }else{
-    getCellInfo(pCur);
-    *pSize = pCur->info.nKey;
-  }
-  return SQLITE_OK;
+  assert( pCur->eState==CURSOR_VALID );
+  assert( pCur->curIntKey );
+  getCellInfo(pCur);
+  return pCur->info.nKey;
 }
 
 /*
-** Set *pSize to the number of bytes of data in the entry the
-** cursor currently points to.
+** Return the number of bytes of payload for the entry that pCur is
+** currently pointing to.  For table btrees, this will be the amount
+** of data.  For index btrees, this will be the size of the key.
 **
 ** The caller must guarantee that the cursor is pointing to a non-NULL
 ** valid entry.  In other words, the calling procedure must guarantee
 ** that the cursor has Cursor.eState==CURSOR_VALID.
-**
-** Failure is not possible.  This function always returns SQLITE_OK.
-** It might just as well be a procedure (returning void) but we continue
-** to return an integer result code for historical reasons.
 */
-SQLITE_PRIVATE int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
+SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor *pCur){
   assert( cursorHoldsMutex(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   getCellInfo(pCur);
-  *pSize = pCur->info.nData;
-  return SQLITE_OK;
+  return pCur->info.nPayload;
 }
 
 /*
@@ -51835,7 +62495,7 @@ static int getOverflowPage(
 
   assert( next==0 || rc==SQLITE_DONE );
   if( rc==SQLITE_OK ){
-    rc = btreeGetPage(pBt, ovfl, &pPage, 0);
+    rc = btreeGetPage(pBt, ovfl, &pPage, (ppPage==0) ? PAGER_GET_READONLY : 0);
     assert( rc==SQLITE_OK || pPage==0 );
     if( rc==SQLITE_OK ){
       next = get4byte(pPage->aData);
@@ -51885,10 +62545,12 @@ static int copyPayload(
 
 /*
 ** This function is used to read or overwrite payload information
-** for the entry that the pCur cursor is pointing to. If the eOp
-** parameter is 0, this is a read operation (data copied into
-** buffer pBuf). If it is non-zero, a write (data copied from
-** buffer pBuf).
+** for the entry that the pCur cursor is pointing to. The eOp
+** argument is interpreted as follows:
+**
+**   0: The operation is a read. Populate the overflow cache.
+**   1: The operation is a write. Populate the overflow cache.
+**   2: The operation is a read. Do not populate the overflow cache.
 **
 ** A total of "amt" bytes are read or written beginning at "offset".
 ** Data is read to or from the buffer pBuf.
@@ -51896,11 +62558,11 @@ static int copyPayload(
 ** The content being read or written might appear on the main page
 ** or be scattered out on multiple overflow pages.
 **
-** If the BtCursor.isIncrblobHandle flag is set, and the current
-** cursor entry uses one or more overflow pages, this function
-** allocates space for and lazily popluates the overflow page-list 
-** cache array (BtCursor.aOverflow). Subsequent calls use this
-** cache to make seeking to the supplied offset more efficient.
+** If the current cursor entry uses one or more overflow pages and the
+** eOp argument is not 2, this function may allocate space for and lazily 
+** populates the overflow page-list cache array (BtCursor.aOverflow). 
+** Subsequent calls use this cache to make seeking to the supplied offset 
+** more efficient.
 **
 ** Once an overflow page-list cache has been allocated, it may be
 ** invalidated if some other cursor writes to the same table, or if
@@ -51920,24 +62582,34 @@ static int accessPayload(
 ){
   unsigned char *aPayload;
   int rc = SQLITE_OK;
-  u32 nKey;
   int iIdx = 0;
   MemPage *pPage = pCur->apPage[pCur->iPage]; /* Btree page of current entry */
   BtShared *pBt = pCur->pBt;                  /* Btree this cursor belongs to */
+#ifdef SQLITE_DIRECT_OVERFLOW_READ
+  unsigned char * const pBufStart = pBuf;
+  int bEnd;                                 /* True if reading to end of data */
+#endif
 
   assert( pPage );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
   assert( cursorHoldsMutex(pCur) );
+  assert( eOp!=2 || offset==0 );    /* Always start from beginning for eOp==2 */
 
   getCellInfo(pCur);
-  aPayload = pCur->info.pCell + pCur->info.nHeader;
-  nKey = (pPage->intKey ? 0 : (int)pCur->info.nKey);
+  aPayload = pCur->info.pPayload;
+#ifdef SQLITE_DIRECT_OVERFLOW_READ
+  bEnd = offset+amt==pCur->info.nPayload;
+#endif
+  assert( offset+amt <= pCur->info.nPayload );
 
-  if( NEVER(offset+amt > nKey+pCur->info.nData) 
-   || &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
-  ){
-    /* Trying to read or write past the end of the data is an error */
+  assert( aPayload > pPage->aData );
+  if( (uptr)(aPayload - pPage->aData) > (pBt->usableSize - pCur->info.nLocal) ){
+    /* Trying to read or write past the end of the data is an error.  The
+    ** conditional above is really:
+    **    &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
+    ** but is recast into its current form to avoid integer overflow problems
+    */
     return SQLITE_CORRUPT_BKPT;
   }
 
@@ -51947,7 +62619,7 @@ static int accessPayload(
     if( a+offset>pCur->info.nLocal ){
       a = pCur->info.nLocal - offset;
     }
-    rc = copyPayload(&aPayload[offset], pBuf, a, eOp, pPage->pDbPage);
+    rc = copyPayload(&aPayload[offset], pBuf, a, (eOp & 0x01), pPage->pDbPage);
     offset = 0;
     pBuf += a;
     amt -= a;
@@ -51955,27 +62627,37 @@ static int accessPayload(
     offset -= pCur->info.nLocal;
   }
 
+
   if( rc==SQLITE_OK && amt>0 ){
     const u32 ovflSize = pBt->usableSize - 4;  /* Bytes content per ovfl page */
     Pgno nextPage;
 
     nextPage = get4byte(&aPayload[pCur->info.nLocal]);
 
-#ifndef SQLITE_OMIT_INCRBLOB
-    /* If the isIncrblobHandle flag is set and the BtCursor.aOverflow[]
-    ** has not been allocated, allocate it now. The array is sized at
-    ** one entry for each overflow page in the overflow chain. The
-    ** page number of the first overflow page is stored in aOverflow[0],
-    ** etc. A value of 0 in the aOverflow[] array means "not yet known"
-    ** (the cache is lazily populated).
+    /* If the BtCursor.aOverflow[] has not been allocated, allocate it now.
+    ** Except, do not allocate aOverflow[] for eOp==2.
+    **
+    ** The aOverflow[] array is sized at one entry for each overflow page
+    ** in the overflow chain. The page number of the first overflow page is
+    ** stored in aOverflow[0], etc. A value of 0 in the aOverflow[] array
+    ** means "not yet known" (the cache is lazily populated).
     */
-    if( pCur->isIncrblobHandle && !pCur->aOverflow ){
+    if( eOp!=2 && (pCur->curFlags & BTCF_ValidOvfl)==0 ){
       int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
-      pCur->aOverflow = (Pgno *)sqlite3MallocZero(sizeof(Pgno)*nOvfl);
-      /* nOvfl is always positive.  If it were zero, fetchPayload would have
-      ** been used instead of this routine. */
-      if( ALWAYS(nOvfl) && !pCur->aOverflow ){
-        rc = SQLITE_NOMEM;
+      if( nOvfl>pCur->nOvflAlloc ){
+        Pgno *aNew = (Pgno*)sqlite3Realloc(
+            pCur->aOverflow, nOvfl*2*sizeof(Pgno)
+        );
+        if( aNew==0 ){
+          rc = SQLITE_NOMEM_BKPT;
+        }else{
+          pCur->nOvflAlloc = nOvfl*2;
+          pCur->aOverflow = aNew;
+        }
+      }
+      if( rc==SQLITE_OK ){
+        memset(pCur->aOverflow, 0, nOvfl*sizeof(Pgno));
+        pCur->curFlags |= BTCF_ValidOvfl;
       }
     }
 
@@ -51983,22 +62665,23 @@ static int accessPayload(
     ** entry for the first required overflow page is valid, skip
     ** directly to it.
     */
-    if( pCur->aOverflow && pCur->aOverflow[offset/ovflSize] ){
+    if( (pCur->curFlags & BTCF_ValidOvfl)!=0
+     && pCur->aOverflow[offset/ovflSize]
+    ){
       iIdx = (offset/ovflSize);
       nextPage = pCur->aOverflow[iIdx];
       offset = (offset%ovflSize);
     }
-#endif
 
     for( ; rc==SQLITE_OK && amt>0 && nextPage; iIdx++){
 
-#ifndef SQLITE_OMIT_INCRBLOB
       /* If required, populate the overflow page-list cache. */
-      if( pCur->aOverflow ){
-        assert(!pCur->aOverflow[iIdx] || pCur->aOverflow[iIdx]==nextPage);
+      if( (pCur->curFlags & BTCF_ValidOvfl)!=0 ){
+        assert( pCur->aOverflow[iIdx]==0
+                || pCur->aOverflow[iIdx]==nextPage
+                || CORRUPT_DB );
         pCur->aOverflow[iIdx] = nextPage;
       }
-#endif
 
       if( offset>=ovflSize ){
         /* The only reason to read this page is to obtain the page
@@ -52006,13 +62689,18 @@ static int accessPayload(
         ** data is not required. So first try to lookup the overflow
         ** page-list cache, if any, then fall back to the getOverflowPage()
         ** function.
+        **
+        ** Note that the aOverflow[] array must be allocated because eOp!=2
+        ** here.  If eOp==2, then offset==0 and this branch is never taken.
         */
-#ifndef SQLITE_OMIT_INCRBLOB
-        if( pCur->aOverflow && pCur->aOverflow[iIdx+1] ){
+        assert( eOp!=2 );
+        assert( pCur->curFlags & BTCF_ValidOvfl );
+        assert( pCur->pBtree->db==pBt->db );
+        if( pCur->aOverflow[iIdx+1] ){
           nextPage = pCur->aOverflow[iIdx+1];
-        } else 
-#endif
+        }else{
           rc = getOverflowPage(pBt, nextPage, 0, &nextPage);
+        }
         offset -= ovflSize;
       }else{
         /* Need to read this page properly. It contains some of the
@@ -52034,21 +62722,26 @@ static int accessPayload(
         **   3) the database is file-backed, and
         **   4) there is no open write-transaction, and
         **   5) the database is not a WAL database,
+        **   6) all data from the page is being read.
+        **   7) at least 4 bytes have already been read into the output buffer 
         **
         ** then data can be read directly from the database file into the
         ** output buffer, bypassing the page-cache altogether. This speeds
         ** up loading large records that span many overflow pages.
         */
-        if( eOp==0                                             /* (1) */
+        if( (eOp&0x01)==0                                      /* (1) */
          && offset==0                                          /* (2) */
+         && (bEnd || a==ovflSize)                              /* (6) */
          && pBt->inTransaction==TRANS_READ                     /* (4) */
          && (fd = sqlite3PagerFile(pBt->pPager))->pMethods     /* (3) */
          && pBt->pPage1->aData[19]==0x01                       /* (5) */
+         && &pBuf[-4]>=pBufStart                               /* (7) */
         ){
           u8 aSave[4];
           u8 *aWrite = &pBuf[-4];
+          assert( aWrite>=pBufStart );                         /* hence (7) */
           memcpy(aSave, aWrite, 4);
-          rc = sqlite3OsRead(fd, aWrite, a+4, pBt->pageSize * (nextPage-1));
+          rc = sqlite3OsRead(fd, aWrite, a+4, (i64)pBt->pageSize*(nextPage-1));
           nextPage = get4byte(aWrite);
           memcpy(aWrite, aSave, 4);
         }else
@@ -52056,11 +62749,13 @@ static int accessPayload(
 
         {
           DbPage *pDbPage;
-          rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage);
+          rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage,
+              ((eOp&0x01)==0 ? PAGER_GET_READONLY : 0)
+          );
           if( rc==SQLITE_OK ){
             aPayload = sqlite3PagerGetData(pDbPage);
             nextPage = get4byte(aPayload);
-            rc = copyPayload(&aPayload[offset+4], pBuf, a, eOp, pDbPage);
+            rc = copyPayload(&aPayload[offset+4], pBuf, a, (eOp&0x01), pDbPage);
             sqlite3PagerUnref(pDbPage);
             offset = 0;
           }
@@ -52079,7 +62774,7 @@ static int accessPayload(
 
 /*
 ** Read part of the key associated with cursor pCur.  Exactly
-** "amt" bytes will be transfered into pBuf[].  The transfer
+** "amt" bytes will be transferred into pBuf[].  The transfer
 ** begins at "offset".
 **
 ** The caller must ensure that pCur is pointing to a valid row
@@ -52115,7 +62810,7 @@ SQLITE_PRIVATE int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *p
   }
 #endif
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   rc = restoreCursorPosition(pCur);
   if( rc==SQLITE_OK ){
     assert( pCur->eState==CURSOR_VALID );
@@ -52129,10 +62824,10 @@ SQLITE_PRIVATE int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *p
 /*
 ** Return a pointer to payload information from the entry that the 
 ** pCur cursor is pointing to.  The pointer is to the beginning of
-** the key if skipKey==0 and it points to the beginning of data if
-** skipKey==1.  The number of bytes of available key/data is written
-** into *pAmt.  If *pAmt==0, then the value returned will not be
-** a valid pointer.
+** the key if index btrees (pPage->intKey==0) and is the data for
+** table btrees (pPage->intKey==1). The number of bytes of available
+** key/data is written into *pAmt.  If *pAmt==0, then the value
+** returned will not be a valid pointer.
 **
 ** This routine is an optimization.  It is common for the entire key
 ** and data to fit on the local page and for there to be no overflow
@@ -52145,41 +62840,23 @@ SQLITE_PRIVATE int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *p
 ** page of the database.  The data might change or move the next time
 ** any btree routine is called.
 */
-static const unsigned char *fetchPayload(
+static const void *fetchPayload(
   BtCursor *pCur,      /* Cursor pointing to entry to read from */
-  int *pAmt,           /* Write the number of available bytes here */
-  int skipKey          /* read beginning at data if this is true */
+  u32 *pAmt            /* Write the number of available bytes here */
 ){
-  unsigned char *aPayload;
-  MemPage *pPage;
-  u32 nKey;
-  u32 nLocal;
-
+  u32 amt;
   assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
   assert( pCur->eState==CURSOR_VALID );
-  assert( cursorHoldsMutex(pCur) );
-  pPage = pCur->apPage[pCur->iPage];
-  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
-  if( NEVER(pCur->info.nSize==0) ){
-    btreeParseCell(pCur->apPage[pCur->iPage], pCur->aiIdx[pCur->iPage],
-                   &pCur->info);
-  }
-  aPayload = pCur->info.pCell;
-  aPayload += pCur->info.nHeader;
-  if( pPage->intKey ){
-    nKey = 0;
-  }else{
-    nKey = (int)pCur->info.nKey;
-  }
-  if( skipKey ){
-    aPayload += nKey;
-    nLocal = pCur->info.nLocal - nKey;
-  }else{
-    nLocal = pCur->info.nLocal;
-    assert( nLocal<=nKey );
-  }
-  *pAmt = nLocal;
-  return aPayload;
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
+  assert( pCur->info.nSize>0 );
+  assert( pCur->info.pPayload>pCur->apPage[pCur->iPage]->aData || CORRUPT_DB );
+  assert( pCur->info.pPayload<pCur->apPage[pCur->iPage]->aDataEnd ||CORRUPT_DB);
+  amt = (int)(pCur->apPage[pCur->iPage]->aDataEnd - pCur->info.pPayload);
+  if( pCur->info.nLocal<amt ) amt = pCur->info.nLocal;
+  *pAmt = amt;
+  return (void*)pCur->info.pPayload;
 }
 
 
@@ -52197,23 +62874,8 @@ static const unsigned char *fetchPayload(
 ** These routines is used to get quick access to key and data
 ** in the common case where no overflow pages are used.
 */
-SQLITE_PRIVATE const void *sqlite3BtreeKeyFetch(BtCursor *pCur, int *pAmt){
-  const void *p = 0;
-  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  assert( cursorHoldsMutex(pCur) );
-  if( ALWAYS(pCur->eState==CURSOR_VALID) ){
-    p = (const void*)fetchPayload(pCur, pAmt, 0);
-  }
-  return p;
-}
-SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor *pCur, int *pAmt){
-  const void *p = 0;
-  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  assert( cursorHoldsMutex(pCur) );
-  if( ALWAYS(pCur->eState==CURSOR_VALID) ){
-    p = (const void*)fetchPayload(pCur, pAmt, 1);
-  }
-  return p;
+SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor *pCur, u32 *pAmt){
+  return fetchPayload(pCur, pAmt);
 }
 
 
@@ -52227,32 +62889,24 @@ SQLITE_PRIVATE const void *sqlite3BtreeDataFetch(BtCursor *pCur, int *pAmt){
 ** vice-versa).
 */
 static int moveToChild(BtCursor *pCur, u32 newPgno){
-  int rc;
-  int i = pCur->iPage;
-  MemPage *pNewPage;
   BtShared *pBt = pCur->pBt;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
+  assert( pCur->iPage>=0 );
   if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
     return SQLITE_CORRUPT_BKPT;
   }
-  rc = getAndInitPage(pBt, newPgno, &pNewPage);
-  if( rc ) return rc;
-  pCur->apPage[i+1] = pNewPage;
-  pCur->aiIdx[i+1] = 0;
-  pCur->iPage++;
-
   pCur->info.nSize = 0;
-  pCur->validNKey = 0;
-  if( pNewPage->nCell<1 || pNewPage->intKey!=pCur->apPage[i]->intKey ){
-    return SQLITE_CORRUPT_BKPT;
-  }
-  return SQLITE_OK;
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+  pCur->iPage++;
+  pCur->aiIdx[pCur->iPage] = 0;
+  return getAndInitPage(pBt, newPgno, &pCur->apPage[pCur->iPage],
+                        pCur, pCur->curPagerFlags);
 }
 
-#ifndef NDEBUG
+#if SQLITE_DEBUG
 /*
 ** Page pParent is an internal (non-leaf) tree page. This function 
 ** asserts that page number iChild is the left-child if the iIdx'th
@@ -52261,6 +62915,8 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
 ** the page.
 */
 static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
+  if( CORRUPT_DB ) return;  /* The conditions tested below might not be true
+                            ** in a corrupt database */
   assert( iIdx<=pParent->nCell );
   if( iIdx==pParent->nCell ){
     assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );
@@ -52281,7 +62937,7 @@ static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
 ** the largest cell index.
 */
 static void moveToParent(BtCursor *pCur){
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   assert( pCur->iPage>0 );
   assert( pCur->apPage[pCur->iPage] );
@@ -52290,10 +62946,10 @@ static void moveToParent(BtCursor *pCur){
     pCur->aiIdx[pCur->iPage-1], 
     pCur->apPage[pCur->iPage]->pgno
   );
-  releasePage(pCur->apPage[pCur->iPage]);
-  pCur->iPage--;
+  testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
   pCur->info.nSize = 0;
-  pCur->validNKey = 0;
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+  releasePageNotNull(pCur->apPage[pCur->iPage--]);
 }
 
 /*
@@ -52320,10 +62976,8 @@ static void moveToParent(BtCursor *pCur){
 static int moveToRoot(BtCursor *pCur){
   MemPage *pRoot;
   int rc = SQLITE_OK;
-  Btree *p = pCur->pBtree;
-  BtShared *pBt = p->pBt;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
   assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );
   assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );
@@ -52336,55 +62990,56 @@ static int moveToRoot(BtCursor *pCur){
   }
 
   if( pCur->iPage>=0 ){
-    int i;
-    for(i=1; i<=pCur->iPage; i++){
-      releasePage(pCur->apPage[i]);
+    while( pCur->iPage ){
+      assert( pCur->apPage[pCur->iPage]!=0 );
+      releasePageNotNull(pCur->apPage[pCur->iPage--]);
     }
-    pCur->iPage = 0;
   }else if( pCur->pgnoRoot==0 ){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;
   }else{
-    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
+    assert( pCur->iPage==(-1) );
+    rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
+                        0, pCur->curPagerFlags);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
       return rc;
     }
     pCur->iPage = 0;
-
-    /* If pCur->pKeyInfo is not NULL, then the caller that opened this cursor
-    ** expected to open it on an index b-tree. Otherwise, if pKeyInfo is
-    ** NULL, the caller expects a table b-tree. If this is not the case,
-    ** return an SQLITE_CORRUPT error.  */
-    assert( pCur->apPage[0]->intKey==1 || pCur->apPage[0]->intKey==0 );
-    if( (pCur->pKeyInfo==0)!=pCur->apPage[0]->intKey ){
-      return SQLITE_CORRUPT_BKPT;
-    }
+    pCur->curIntKey = pCur->apPage[0]->intKey;
   }
-
-  /* Assert that the root page is of the correct type. This must be the
-  ** case as the call to this function that loaded the root-page (either
-  ** this call or a previous invocation) would have detected corruption 
-  ** if the assumption were not true, and it is not possible for the flags 
-  ** byte to have been modified while this cursor is holding a reference
-  ** to the page.  */
   pRoot = pCur->apPage[0];
   assert( pRoot->pgno==pCur->pgnoRoot );
-  assert( pRoot->isInit && (pCur->pKeyInfo==0)==pRoot->intKey );
+
+  /* If pCur->pKeyInfo is not NULL, then the caller that opened this cursor
+  ** expected to open it on an index b-tree. Otherwise, if pKeyInfo is
+  ** NULL, the caller expects a table b-tree. If this is not the case,
+  ** return an SQLITE_CORRUPT error. 
+  **
+  ** Earlier versions of SQLite assumed that this test could not fail
+  ** if the root page was already loaded when this function was called (i.e.
+  ** if pCur->iPage>=0). But this is not so if the database is corrupted 
+  ** in such a way that page pRoot is linked into a second b-tree table 
+  ** (or the freelist).  */
+  assert( pRoot->intKey==1 || pRoot->intKey==0 );
+  if( pRoot->isInit==0 || (pCur->pKeyInfo==0)!=pRoot->intKey ){
+    return SQLITE_CORRUPT_BKPT;
+  }
 
   pCur->aiIdx[0] = 0;
   pCur->info.nSize = 0;
-  pCur->atLast = 0;
-  pCur->validNKey = 0;
+  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);
 
-  if( pRoot->nCell==0 && !pRoot->leaf ){
+  if( pRoot->nCell>0 ){
+    pCur->eState = CURSOR_VALID;
+  }else if( !pRoot->leaf ){
     Pgno subpage;
     if( pRoot->pgno!=1 ) return SQLITE_CORRUPT_BKPT;
     subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
     pCur->eState = CURSOR_VALID;
     rc = moveToChild(pCur, subpage);
   }else{
-    pCur->eState = ((pRoot->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
+    pCur->eState = CURSOR_INVALID;
   }
   return rc;
 }
@@ -52401,7 +63056,7 @@ static int moveToLeftmost(BtCursor *pCur){
   int rc = SQLITE_OK;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
   while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
     assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
@@ -52426,19 +63081,18 @@ static int moveToRightmost(BtCursor *pCur){
   int rc = SQLITE_OK;
   MemPage *pPage = 0;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pCur->eState==CURSOR_VALID );
-  while( rc==SQLITE_OK && !(pPage = pCur->apPage[pCur->iPage])->leaf ){
+  while( !(pPage = pCur->apPage[pCur->iPage])->leaf ){
     pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
     pCur->aiIdx[pCur->iPage] = pPage->nCell;
     rc = moveToChild(pCur, pgno);
+    if( rc ) return rc;
   }
-  if( rc==SQLITE_OK ){
-    pCur->aiIdx[pCur->iPage] = pPage->nCell-1;
-    pCur->info.nSize = 0;
-    pCur->validNKey = 0;
-  }
-  return rc;
+  pCur->aiIdx[pCur->iPage] = pPage->nCell-1;
+  assert( pCur->info.nSize==0 );
+  assert( (pCur->curFlags & BTCF_ValidNKey)==0 );
+  return SQLITE_OK;
 }
 
 /* Move the cursor to the first entry in the table.  Return SQLITE_OK
@@ -52448,7 +63102,7 @@ static int moveToRightmost(BtCursor *pCur){
 SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
   int rc;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
   rc = moveToRoot(pCur);
   if( rc==SQLITE_OK ){
@@ -52471,11 +63125,11 @@ SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){
 SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
   int rc;
  
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
 
   /* If the cursor already points to the last entry, this is a no-op. */
-  if( CURSOR_VALID==pCur->eState && pCur->atLast ){
+  if( CURSOR_VALID==pCur->eState && (pCur->curFlags & BTCF_AtLast)!=0 ){
 #ifdef SQLITE_DEBUG
     /* This block serves to assert() that the cursor really does point 
     ** to the last entry in the b-tree. */
@@ -52498,7 +63152,12 @@ SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
       assert( pCur->eState==CURSOR_VALID );
       *pRes = 0;
       rc = moveToRightmost(pCur);
-      pCur->atLast = rc==SQLITE_OK ?1:0;
+      if( rc==SQLITE_OK ){
+        pCur->curFlags |= BTCF_AtLast;
+      }else{
+        pCur->curFlags &= ~BTCF_AtLast;
+      }
+   
     }
   }
   return rc;
@@ -52531,6 +63190,8 @@ SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
 **     *pRes>0      The cursor is left pointing at an entry that
 **                  is larger than intKey/pIdxKey.
 **
+** For index tables, the pIdxKey->eqSeen field is set to 1 if there
+** exists an entry in the table that exactly matches pIdxKey.  
 */
 SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
   BtCursor *pCur,          /* The cursor to be moved */
@@ -52540,27 +63201,40 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
   int *pRes                /* Write search results here */
 ){
   int rc;
+  RecordCompare xRecordCompare;
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
   assert( pRes );
   assert( (pIdxKey==0)==(pCur->pKeyInfo==0) );
+  assert( pCur->eState!=CURSOR_VALID || (pIdxKey==0)==(pCur->curIntKey!=0) );
 
   /* If the cursor is already positioned at the point we are trying
   ** to move to, then just return without doing any work */
-  if( pCur->eState==CURSOR_VALID && pCur->validNKey 
-   && pCur->apPage[0]->intKey 
+  if( pIdxKey==0
+   && pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
   ){
     if( pCur->info.nKey==intKey ){
       *pRes = 0;
       return SQLITE_OK;
     }
-    if( pCur->atLast && pCur->info.nKey<intKey ){
+    if( (pCur->curFlags & BTCF_AtLast)!=0 && pCur->info.nKey<intKey ){
       *pRes = -1;
       return SQLITE_OK;
     }
   }
 
+  if( pIdxKey ){
+    xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);
+    pIdxKey->errCode = 0;
+    assert( pIdxKey->default_rc==1 
+         || pIdxKey->default_rc==0 
+         || pIdxKey->default_rc==-1
+    );
+  }else{
+    xRecordCompare = 0; /* All keys are integers */
+  }
+
   rc = moveToRoot(pCur);
   if( rc ){
     return rc;
@@ -52573,12 +63247,13 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
     assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
     return SQLITE_OK;
   }
-  assert( pCur->apPage[0]->intKey || pIdxKey );
+  assert( pCur->apPage[0]->intKey==pCur->curIntKey );
+  assert( pCur->curIntKey || pIdxKey );
   for(;;){
-    int lwr, upr, idx;
+    int lwr, upr, idx, c;
     Pgno chldPg;
     MemPage *pPage = pCur->apPage[pCur->iPage];
-    int c;
+    u8 *pCell;                          /* Pointer to current cell in pPage */
 
     /* pPage->nCell must be greater than zero. If this is the root-page
     ** the cursor would have been INVALID above and this for(;;) loop
@@ -52590,35 +63265,47 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
     assert( pPage->intKey==(pIdxKey==0) );
     lwr = 0;
     upr = pPage->nCell-1;
-    if( biasRight ){
-      pCur->aiIdx[pCur->iPage] = (u16)(idx = upr);
-    }else{
-      pCur->aiIdx[pCur->iPage] = (u16)(idx = (upr+lwr)/2);
-    }
-    for(;;){
-      u8 *pCell;                          /* Pointer to current cell in pPage */
-
-      assert( idx==pCur->aiIdx[pCur->iPage] );
-      pCur->info.nSize = 0;
-      pCell = findCell(pPage, idx) + pPage->childPtrSize;
-      if( pPage->intKey ){
+    assert( biasRight==0 || biasRight==1 );
+    idx = upr>>(1-biasRight); /* idx = biasRight ? upr : (lwr+upr)/2; */
+    pCur->aiIdx[pCur->iPage] = (u16)idx;
+    if( xRecordCompare==0 ){
+      for(;;){
         i64 nCellKey;
-        if( pPage->hasData ){
-          u32 dummy;
-          pCell += getVarint32(pCell, dummy);
+        pCell = findCellPastPtr(pPage, idx);
+        if( pPage->intKeyLeaf ){
+          while( 0x80 <= *(pCell++) ){
+            if( pCell>=pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;
+          }
         }
         getVarint(pCell, (u64*)&nCellKey);
-        if( nCellKey==intKey ){
-          c = 0;
-        }else if( nCellKey<intKey ){
-          c = -1;
+        if( nCellKey<intKey ){
+          lwr = idx+1;
+          if( lwr>upr ){ c = -1; break; }
+        }else if( nCellKey>intKey ){
+          upr = idx-1;
+          if( lwr>upr ){ c = +1; break; }
         }else{
-          assert( nCellKey>intKey );
-          c = +1;
+          assert( nCellKey==intKey );
+          pCur->curFlags |= BTCF_ValidNKey;
+          pCur->info.nKey = nCellKey;
+          pCur->aiIdx[pCur->iPage] = (u16)idx;
+          if( !pPage->leaf ){
+            lwr = idx;
+            goto moveto_next_layer;
+          }else{
+            *pRes = 0;
+            rc = SQLITE_OK;
+            goto moveto_finish;
+          }
         }
-        pCur->validNKey = 1;
-        pCur->info.nKey = nCellKey;
-      }else{
+        assert( lwr+upr>=0 );
+        idx = (lwr+upr)>>1;  /* idx = (lwr+upr)/2; */
+      }
+    }else{
+      for(;;){
+        int nCell;  /* Size of the pCell cell in bytes */
+        pCell = findCellPastPtr(pPage, idx);
+
         /* The maximum supported page-size is 65536 bytes. This means that
         ** the maximum number of record bytes stored on an index B-Tree
         ** page is less than 16384 bytes and may be stored as a 2-byte
@@ -52627,83 +63314,99 @@ SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(
         ** stored entirely within the b-tree page by inspecting the first 
         ** 2 bytes of the cell.
         */
-        int nCell = pCell[0];
-        if( !(nCell & 0x80) && nCell<=pPage->maxLocal ){
+        nCell = pCell[0];
+        if( nCell<=pPage->max1bytePayload ){
           /* This branch runs if the record-size field of the cell is a
           ** single byte varint and the record fits entirely on the main
           ** b-tree page.  */
-          c = sqlite3VdbeRecordCompare(nCell, (void*)&pCell[1], pIdxKey);
+          testcase( pCell+nCell+1==pPage->aDataEnd );
+          c = xRecordCompare(nCell, (void*)&pCell[1], pIdxKey);
         }else if( !(pCell[1] & 0x80) 
           && (nCell = ((nCell&0x7f)<<7) + pCell[1])<=pPage->maxLocal
         ){
           /* The record-size field is a 2 byte varint and the record 
           ** fits entirely on the main b-tree page.  */
-          c = sqlite3VdbeRecordCompare(nCell, (void*)&pCell[2], pIdxKey);
+          testcase( pCell+nCell+2==pPage->aDataEnd );
+          c = xRecordCompare(nCell, (void*)&pCell[2], pIdxKey);
         }else{
           /* The record flows over onto one or more overflow pages. In
           ** this case the whole cell needs to be parsed, a buffer allocated
           ** and accessPayload() used to retrieve the record into the
-          ** buffer before VdbeRecordCompare() can be called. */
+          ** buffer before VdbeRecordCompare() can be called. 
+          **
+          ** If the record is corrupt, the xRecordCompare routine may read
+          ** up to two varints past the end of the buffer. An extra 18 
+          ** bytes of padding is allocated at the end of the buffer in
+          ** case this happens.  */
           void *pCellKey;
           u8 * const pCellBody = pCell - pPage->childPtrSize;
-          btreeParseCellPtr(pPage, pCellBody, &pCur->info);
+          pPage->xParseCell(pPage, pCellBody, &pCur->info);
           nCell = (int)pCur->info.nKey;
-          pCellKey = sqlite3Malloc( nCell );
+          testcase( nCell<0 );   /* True if key size is 2^32 or more */
+          testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */
+          testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */
+          testcase( nCell==2 );  /* Minimum legal index key size */
+          if( nCell<2 ){
+            rc = SQLITE_CORRUPT_BKPT;
+            goto moveto_finish;
+          }
+          pCellKey = sqlite3Malloc( nCell+18 );
           if( pCellKey==0 ){
-            rc = SQLITE_NOMEM;
+            rc = SQLITE_NOMEM_BKPT;
             goto moveto_finish;
           }
-          rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 0);
+          pCur->aiIdx[pCur->iPage] = (u16)idx;
+          rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 2);
           if( rc ){
             sqlite3_free(pCellKey);
             goto moveto_finish;
           }
-          c = sqlite3VdbeRecordCompare(nCell, pCellKey, pIdxKey);
+          c = xRecordCompare(nCell, pCellKey, pIdxKey);
           sqlite3_free(pCellKey);
         }
-      }
-      if( c==0 ){
-        if( pPage->intKey && !pPage->leaf ){
-          lwr = idx;
-          break;
+        assert( 
+            (pIdxKey->errCode!=SQLITE_CORRUPT || c==0)
+         && (pIdxKey->errCode!=SQLITE_NOMEM || pCur->pBtree->db->mallocFailed)
+        );
+        if( c<0 ){
+          lwr = idx+1;
+        }else if( c>0 ){
+          upr = idx-1;
         }else{
+          assert( c==0 );
           *pRes = 0;
           rc = SQLITE_OK;
+          pCur->aiIdx[pCur->iPage] = (u16)idx;
+          if( pIdxKey->errCode ) rc = SQLITE_CORRUPT;
           goto moveto_finish;
         }
+        if( lwr>upr ) break;
+        assert( lwr+upr>=0 );
+        idx = (lwr+upr)>>1;  /* idx = (lwr+upr)/2 */
       }
-      if( c<0 ){
-        lwr = idx+1;
-      }else{
-        upr = idx-1;
-      }
-      if( lwr>upr ){
-        break;
-      }
-      pCur->aiIdx[pCur->iPage] = (u16)(idx = (lwr+upr)/2);
     }
     assert( lwr==upr+1 || (pPage->intKey && !pPage->leaf) );
     assert( pPage->isInit );
     if( pPage->leaf ){
-      chldPg = 0;
-    }else if( lwr>=pPage->nCell ){
-      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
-    }else{
-      chldPg = get4byte(findCell(pPage, lwr));
-    }
-    if( chldPg==0 ){
       assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
+      pCur->aiIdx[pCur->iPage] = (u16)idx;
       *pRes = c;
       rc = SQLITE_OK;
       goto moveto_finish;
     }
+moveto_next_layer:
+    if( lwr>=pPage->nCell ){
+      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
+    }else{
+      chldPg = get4byte(findCell(pPage, lwr));
+    }
     pCur->aiIdx[pCur->iPage] = (u16)lwr;
-    pCur->info.nSize = 0;
-    pCur->validNKey = 0;
     rc = moveToChild(pCur, chldPg);
-    if( rc ) goto moveto_finish;
+    if( rc ) break;
   }
 moveto_finish:
+  pCur->info.nSize = 0;
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
   return rc;
 }
 
@@ -52728,43 +63431,67 @@ SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor *pCur){
 ** successful then set *pRes=0.  If the cursor
 ** was already pointing to the last entry in the database before
 ** this routine was called, then set *pRes=1.
-*/
-SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
+**
+** The main entry point is sqlite3BtreeNext().  That routine is optimized
+** for the common case of merely incrementing the cell counter BtCursor.aiIdx
+** to the next cell on the current page.  The (slower) btreeNext() helper
+** routine is called when it is necessary to move to a different page or
+** to restore the cursor.
+**
+** The calling function will set *pRes to 0 or 1.  The initial *pRes value
+** will be 1 if the cursor being stepped corresponds to an SQL index and
+** if this routine could have been skipped if that SQL index had been
+** a unique index.  Otherwise the caller will have set *pRes to zero.
+** Zero is the common case. The btree implementation is free to use the
+** initial *pRes value as a hint to improve performance, but the current
+** SQLite btree implementation does not. (Note that the comdb2 btree
+** implementation does use this hint, however.)
+*/
+static SQLITE_NOINLINE int btreeNext(BtCursor *pCur, int *pRes){
   int rc;
   int idx;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
-  rc = restoreCursorPosition(pCur);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-  assert( pRes!=0 );
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
-  if( pCur->skipNext>0 ){
-    pCur->skipNext = 0;
-    *pRes = 0;
-    return SQLITE_OK;
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
+  assert( *pRes==0 );
+  if( pCur->eState!=CURSOR_VALID ){
+    assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
+    rc = restoreCursorPosition(pCur);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    if( CURSOR_INVALID==pCur->eState ){
+      *pRes = 1;
+      return SQLITE_OK;
+    }
+    if( pCur->skipNext ){
+      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
+      pCur->eState = CURSOR_VALID;
+      if( pCur->skipNext>0 ){
+        pCur->skipNext = 0;
+        return SQLITE_OK;
+      }
+      pCur->skipNext = 0;
+    }
   }
-  pCur->skipNext = 0;
 
   pPage = pCur->apPage[pCur->iPage];
   idx = ++pCur->aiIdx[pCur->iPage];
   assert( pPage->isInit );
-  assert( idx<=pPage->nCell );
 
-  pCur->info.nSize = 0;
-  pCur->validNKey = 0;
+  /* If the database file is corrupt, it is possible for the value of idx 
+  ** to be invalid here. This can only occur if a second cursor modifies
+  ** the page while cursor pCur is holding a reference to it. Which can
+  ** only happen if the database is corrupt in such a way as to link the
+  ** page into more than one b-tree structure. */
+  testcase( idx>pPage->nCell );
+
   if( idx>=pPage->nCell ){
     if( !pPage->leaf ){
       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
       if( rc ) return rc;
-      rc = moveToLeftmost(pCur);
-      *pRes = 0;
-      return rc;
+      return moveToLeftmost(pCur);
     }
     do{
       if( pCur->iPage==0 ){
@@ -52775,58 +63502,97 @@ SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
       moveToParent(pCur);
       pPage = pCur->apPage[pCur->iPage];
     }while( pCur->aiIdx[pCur->iPage]>=pPage->nCell );
-    *pRes = 0;
     if( pPage->intKey ){
-      rc = sqlite3BtreeNext(pCur, pRes);
+      return sqlite3BtreeNext(pCur, pRes);
     }else{
-      rc = SQLITE_OK;
+      return SQLITE_OK;
     }
-    return rc;
   }
+  if( pPage->leaf ){
+    return SQLITE_OK;
+  }else{
+    return moveToLeftmost(pCur);
+  }
+}
+SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
+  MemPage *pPage;
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pRes!=0 );
+  assert( *pRes==0 || *pRes==1 );
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
+  pCur->info.nSize = 0;
+  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
   *pRes = 0;
+  if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur, pRes);
+  pPage = pCur->apPage[pCur->iPage];
+  if( (++pCur->aiIdx[pCur->iPage])>=pPage->nCell ){
+    pCur->aiIdx[pCur->iPage]--;
+    return btreeNext(pCur, pRes);
+  }
   if( pPage->leaf ){
     return SQLITE_OK;
+  }else{
+    return moveToLeftmost(pCur);
   }
-  rc = moveToLeftmost(pCur);
-  return rc;
 }
 
-
 /*
 ** Step the cursor to the back to the previous entry in the database.  If
 ** successful then set *pRes=0.  If the cursor
 ** was already pointing to the first entry in the database before
 ** this routine was called, then set *pRes=1.
-*/
-SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
+**
+** The main entry point is sqlite3BtreePrevious().  That routine is optimized
+** for the common case of merely decrementing the cell counter BtCursor.aiIdx
+** to the previous cell on the current page.  The (slower) btreePrevious()
+** helper routine is called when it is necessary to move to a different page
+** or to restore the cursor.
+**
+** The calling function will set *pRes to 0 or 1.  The initial *pRes value
+** will be 1 if the cursor being stepped corresponds to an SQL index and
+** if this routine could have been skipped if that SQL index had been
+** a unique index.  Otherwise the caller will have set *pRes to zero.
+** Zero is the common case. The btree implementation is free to use the
+** initial *pRes value as a hint to improve performance, but the current
+** SQLite btree implementation does not. (Note that the comdb2 btree
+** implementation does use this hint, however.)
+*/
+static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur, int *pRes){
   int rc;
   MemPage *pPage;
 
-  assert( cursorHoldsMutex(pCur) );
-  rc = restoreCursorPosition(pCur);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-  pCur->atLast = 0;
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
-  if( pCur->skipNext<0 ){
-    pCur->skipNext = 0;
-    *pRes = 0;
-    return SQLITE_OK;
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pRes!=0 );
+  assert( *pRes==0 );
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
+  assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );
+  assert( pCur->info.nSize==0 );
+  if( pCur->eState!=CURSOR_VALID ){
+    rc = restoreCursorPosition(pCur);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    if( CURSOR_INVALID==pCur->eState ){
+      *pRes = 1;
+      return SQLITE_OK;
+    }
+    if( pCur->skipNext ){
+      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
+      pCur->eState = CURSOR_VALID;
+      if( pCur->skipNext<0 ){
+        pCur->skipNext = 0;
+        return SQLITE_OK;
+      }
+      pCur->skipNext = 0;
+    }
   }
-  pCur->skipNext = 0;
 
   pPage = pCur->apPage[pCur->iPage];
   assert( pPage->isInit );
   if( !pPage->leaf ){
     int idx = pCur->aiIdx[pCur->iPage];
     rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
-    if( rc ){
-      return rc;
-    }
+    if( rc ) return rc;
     rc = moveToRightmost(pCur);
   }else{
     while( pCur->aiIdx[pCur->iPage]==0 ){
@@ -52837,8 +63603,8 @@ SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
       }
       moveToParent(pCur);
     }
-    pCur->info.nSize = 0;
-    pCur->validNKey = 0;
+    assert( pCur->info.nSize==0 );
+    assert( (pCur->curFlags & (BTCF_ValidNKey|BTCF_ValidOvfl))==0 );
 
     pCur->aiIdx[pCur->iPage]--;
     pPage = pCur->apPage[pCur->iPage];
@@ -52848,9 +63614,25 @@ SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
       rc = SQLITE_OK;
     }
   }
-  *pRes = 0;
   return rc;
 }
+SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
+  assert( cursorOwnsBtShared(pCur) );
+  assert( pRes!=0 );
+  assert( *pRes==0 || *pRes==1 );
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
+  *pRes = 0;
+  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);
+  pCur->info.nSize = 0;
+  if( pCur->eState!=CURSOR_VALID
+   || pCur->aiIdx[pCur->iPage]==0
+   || pCur->apPage[pCur->iPage]->leaf==0
+  ){
+    return btreePrevious(pCur, pRes);
+  }
+  pCur->aiIdx[pCur->iPage]--;
+  return SQLITE_OK;
+}
 
 /*
 ** Allocate a new page from the database file.
@@ -52861,24 +63643,25 @@ SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
 ** sqlite3PagerUnref() on the new page when it is done.
 **
 ** SQLITE_OK is returned on success.  Any other return value indicates
-** an error.  *ppPage and *pPgno are undefined in the event of an error.
-** Do not invoke sqlite3PagerUnref() on *ppPage if an error is returned.
+** an error.  *ppPage is set to NULL in the event of an error.
 **
-** If the "nearby" parameter is not 0, then a (feeble) effort is made to 
+** If the "nearby" parameter is not 0, then an effort is made to 
 ** locate a page close to the page number "nearby".  This can be used in an
 ** attempt to keep related pages close to each other in the database file,
 ** which in turn can make database access faster.
 **
-** If the "exact" parameter is not 0, and the page-number nearby exists 
-** anywhere on the free-list, then it is guarenteed to be returned. This
-** is only used by auto-vacuum databases when allocating a new table.
+** If the eMode parameter is BTALLOC_EXACT and the nearby page exists
+** anywhere on the free-list, then it is guaranteed to be returned.  If
+** eMode is BTALLOC_LT then the page returned will be less than or equal
+** to nearby if any such page exists.  If eMode is BTALLOC_ANY then there
+** are no restrictions on which page is returned.
 */
 static int allocateBtreePage(
-  BtShared *pBt, 
-  MemPage **ppPage, 
-  Pgno *pPgno, 
-  Pgno nearby,
-  u8 exact
+  BtShared *pBt,         /* The btree */
+  MemPage **ppPage,      /* Store pointer to the allocated page here */
+  Pgno *pPgno,           /* Store the page number here */
+  Pgno nearby,           /* Search for a page near this one */
+  u8 eMode               /* BTALLOC_EXACT, BTALLOC_LT, or BTALLOC_ANY */
 ){
   MemPage *pPage1;
   int rc;
@@ -52889,8 +63672,11 @@ static int allocateBtreePage(
   Pgno mxPage;     /* Total size of the database file */
 
   assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
   pPage1 = pBt->pPage1;
   mxPage = btreePagecount(pBt);
+  /* EVIDENCE-OF: R-05119-02637 The 4-byte big-endian integer at offset 36
+  ** stores stores the total number of pages on the freelist. */
   n = get4byte(&pPage1->aData[36]);
   testcase( n==mxPage-1 );
   if( n>=mxPage ){
@@ -52900,22 +63686,26 @@ static int allocateBtreePage(
     /* There are pages on the freelist.  Reuse one of those pages. */
     Pgno iTrunk;
     u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
+    u32 nSearch = 0;   /* Count of the number of search attempts */
     
-    /* If the 'exact' parameter was true and a query of the pointer-map
+    /* If eMode==BTALLOC_EXACT and a query of the pointer-map
     ** shows that the page 'nearby' is somewhere on the free-list, then
     ** the entire-list will be searched for that page.
     */
 #ifndef SQLITE_OMIT_AUTOVACUUM
-    if( exact && nearby<=mxPage ){
-      u8 eType;
-      assert( nearby>0 );
-      assert( pBt->autoVacuum );
-      rc = ptrmapGet(pBt, nearby, &eType, 0);
-      if( rc ) return rc;
-      if( eType==PTRMAP_FREEPAGE ){
-        searchList = 1;
+    if( eMode==BTALLOC_EXACT ){
+      if( nearby<=mxPage ){
+        u8 eType;
+        assert( nearby>0 );
+        assert( pBt->autoVacuum );
+        rc = ptrmapGet(pBt, nearby, &eType, 0);
+        if( rc ) return rc;
+        if( eType==PTRMAP_FREEPAGE ){
+          searchList = 1;
+        }
       }
-      *pPgno = nearby;
+    }else if( eMode==BTALLOC_LE ){
+      searchList = 1;
     }
 #endif
 
@@ -52928,20 +63718,27 @@ static int allocateBtreePage(
 
     /* The code within this loop is run only once if the 'searchList' variable
     ** is not true. Otherwise, it runs once for each trunk-page on the
-    ** free-list until the page 'nearby' is located.
+    ** free-list until the page 'nearby' is located (eMode==BTALLOC_EXACT)
+    ** or until a page less than 'nearby' is located (eMode==BTALLOC_LT)
     */
     do {
       pPrevTrunk = pTrunk;
       if( pPrevTrunk ){
+        /* EVIDENCE-OF: R-01506-11053 The first integer on a freelist trunk page
+        ** is the page number of the next freelist trunk page in the list or
+        ** zero if this is the last freelist trunk page. */
         iTrunk = get4byte(&pPrevTrunk->aData[0]);
       }else{
+        /* EVIDENCE-OF: R-59841-13798 The 4-byte big-endian integer at offset 32
+        ** stores the page number of the first page of the freelist, or zero if
+        ** the freelist is empty. */
         iTrunk = get4byte(&pPage1->aData[32]);
       }
       testcase( iTrunk==mxPage );
-      if( iTrunk>mxPage ){
+      if( iTrunk>mxPage || nSearch++ > n ){
         rc = SQLITE_CORRUPT_BKPT;
       }else{
-        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+        rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);
       }
       if( rc ){
         pTrunk = 0;
@@ -52949,8 +63746,9 @@ static int allocateBtreePage(
       }
       assert( pTrunk!=0 );
       assert( pTrunk->aData!=0 );
-
-      k = get4byte(&pTrunk->aData[4]); /* # of leaves on this trunk page */
+      /* EVIDENCE-OF: R-13523-04394 The second integer on a freelist trunk page
+      ** is the number of leaf page pointers to follow. */
+      k = get4byte(&pTrunk->aData[4]);
       if( k==0 && !searchList ){
         /* The trunk has no leaves and the list is not being searched. 
         ** So extract the trunk page itself and use it as the newly 
@@ -52970,11 +63768,13 @@ static int allocateBtreePage(
         rc = SQLITE_CORRUPT_BKPT;
         goto end_allocate_page;
 #ifndef SQLITE_OMIT_AUTOVACUUM
-      }else if( searchList && nearby==iTrunk ){
+      }else if( searchList 
+            && (nearby==iTrunk || (iTrunk<nearby && eMode==BTALLOC_LE)) 
+      ){
         /* The list is being searched and this trunk page is the page
         ** to allocate, regardless of whether it has leaves.
         */
-        assert( *pPgno==iTrunk );
+        *pPgno = iTrunk;
         *ppPage = pTrunk;
         searchList = 0;
         rc = sqlite3PagerWrite(pTrunk->pDbPage);
@@ -53003,7 +63803,7 @@ static int allocateBtreePage(
             goto end_allocate_page;
           }
           testcase( iNewTrunk==mxPage );
-          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+          rc = btreeGetUnusedPage(pBt, iNewTrunk, &pNewTrunk, 0);
           if( rc!=SQLITE_OK ){
             goto end_allocate_page;
           }
@@ -53037,14 +63837,24 @@ static int allocateBtreePage(
         unsigned char *aData = pTrunk->aData;
         if( nearby>0 ){
           u32 i;
-          int dist;
           closest = 0;
-          dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);
-          for(i=1; i<k; i++){
-            int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);
-            if( d2<dist ){
-              closest = i;
-              dist = d2;
+          if( eMode==BTALLOC_LE ){
+            for(i=0; i<k; i++){
+              iPage = get4byte(&aData[8+i*4]);
+              if( iPage<=nearby ){
+                closest = i;
+                break;
+              }
+            }
+          }else{
+            int dist;
+            dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);
+            for(i=1; i<k; i++){
+              int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);
+              if( d2<dist ){
+                closest = i;
+                dist = d2;
+              }
             }
           }
         }else{
@@ -53058,7 +63868,9 @@ static int allocateBtreePage(
           goto end_allocate_page;
         }
         testcase( iPage==mxPage );
-        if( !searchList || iPage==nearby ){
+        if( !searchList 
+         || (iPage==nearby || (iPage<nearby && eMode==BTALLOC_LE)) 
+        ){
           int noContent;
           *pPgno = iPage;
           TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"
@@ -53070,12 +63882,13 @@ static int allocateBtreePage(
             memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
           }
           put4byte(&aData[4], k-1);
-          noContent = !btreeGetHasContent(pBt, *pPgno);
-          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
+          noContent = !btreeGetHasContent(pBt, *pPgno)? PAGER_GET_NOCONTENT : 0;
+          rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, noContent);
           if( rc==SQLITE_OK ){
             rc = sqlite3PagerWrite((*ppPage)->pDbPage);
             if( rc!=SQLITE_OK ){
               releasePage(*ppPage);
+              *ppPage = 0;
             }
           }
           searchList = 0;
@@ -53085,8 +63898,26 @@ static int allocateBtreePage(
       pPrevTrunk = 0;
     }while( searchList );
   }else{
-    /* There are no pages on the freelist, so create a new page at the
-    ** end of the file */
+    /* There are no pages on the freelist, so append a new page to the
+    ** database image.
+    **
+    ** Normally, new pages allocated by this block can be requested from the
+    ** pager layer with the 'no-content' flag set. This prevents the pager
+    ** from trying to read the pages content from disk. However, if the
+    ** current transaction has already run one or more incremental-vacuum
+    ** steps, then the page we are about to allocate may contain content
+    ** that is required in the event of a rollback. In this case, do
+    ** not set the no-content flag. This causes the pager to load and journal
+    ** the current page content before overwriting it.
+    **
+    ** Note that the pager will not actually attempt to load or journal 
+    ** content for any page that really does lie past the end of the database
+    ** file on disk. So the effects of disabling the no-content optimization
+    ** here are confined to those pages that lie between the end of the
+    ** database image and the end of the database file.
+    */
+    int bNoContent = (0==IfNotOmitAV(pBt->bDoTruncate))? PAGER_GET_NOCONTENT:0;
+
     rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
     if( rc ) return rc;
     pBt->nPage++;
@@ -53101,7 +63932,7 @@ static int allocateBtreePage(
       MemPage *pPg = 0;
       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));
       assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
-      rc = btreeGetPage(pBt, pBt->nPage, &pPg, 1);
+      rc = btreeGetUnusedPage(pBt, pBt->nPage, &pPg, bNoContent);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pPg->pDbPage);
         releasePage(pPg);
@@ -53115,11 +63946,12 @@ static int allocateBtreePage(
     *pPgno = pBt->nPage;
 
     assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
-    rc = btreeGetPage(pBt, *pPgno, ppPage, 1);
+    rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, bNoContent);
     if( rc ) return rc;
     rc = sqlite3PagerWrite((*ppPage)->pDbPage);
     if( rc!=SQLITE_OK ){
       releasePage(*ppPage);
+      *ppPage = 0;
     }
     TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
   }
@@ -53129,16 +63961,8 @@ static int allocateBtreePage(
 end_allocate_page:
   releasePage(pTrunk);
   releasePage(pPrevTrunk);
-  if( rc==SQLITE_OK ){
-    if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
-      releasePage(*ppPage);
-      return SQLITE_CORRUPT_BKPT;
-    }
-    (*ppPage)->isInit = 0;
-  }else{
-    *ppPage = 0;
-  }
-  assert( rc!=SQLITE_OK || sqlite3PagerIswriteable((*ppPage)->pDbPage) );
+  assert( rc!=SQLITE_OK || sqlite3PagerPageRefcount((*ppPage)->pDbPage)<=1 );
+  assert( rc!=SQLITE_OK || (*ppPage)->isInit==0 );
   return rc;
 }
 
@@ -53163,9 +63987,10 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
   int nFree;                          /* Initial number of pages on free-list */
 
   assert( sqlite3_mutex_held(pBt->mutex) );
-  assert( iPage>1 );
+  assert( CORRUPT_DB || iPage>1 );
   assert( !pMemPage || pMemPage->pgno==iPage );
 
+  if( iPage<2 ) return SQLITE_CORRUPT_BKPT;
   if( pMemPage ){
     pPage = pMemPage;
     sqlite3PagerRef(pPage->pDbPage);
@@ -53179,7 +64004,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
   nFree = get4byte(&pPage1->aData[36]);
   put4byte(&pPage1->aData[36], nFree+1);
 
-  if( pBt->secureDelete ){
+  if( pBt->btsFlags & BTS_SECURE_DELETE ){
     /* If the secure_delete option is enabled, then
     ** always fully overwrite deleted information with zeros.
     */
@@ -53235,12 +64060,17 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
       ** for now.  At some point in the future (once everyone has upgraded
       ** to 3.6.0 or later) we should consider fixing the conditional above
       ** to read "usableSize/4-2" instead of "usableSize/4-8".
+      **
+      ** EVIDENCE-OF: R-19920-11576 However, newer versions of SQLite still
+      ** avoid using the last six entries in the freelist trunk page array in
+      ** order that database files created by newer versions of SQLite can be
+      ** read by older versions of SQLite.
       */
       rc = sqlite3PagerWrite(pTrunk->pDbPage);
       if( rc==SQLITE_OK ){
         put4byte(&pTrunk->aData[4], nLeaf+1);
         put4byte(&pTrunk->aData[8+nLeaf*4], iPage);
-        if( pPage && !pBt->secureDelete ){
+        if( pPage && (pBt->btsFlags & BTS_SECURE_DELETE)==0 ){
           sqlite3PagerDontWrite(pPage->pDbPage);
         }
         rc = btreeSetHasContent(pBt, iPage);
@@ -53283,9 +64113,15 @@ static void freePage(MemPage *pPage, int *pRC){
 }
 
 /*
-** Free any overflow pages associated with the given Cell.
+** Free any overflow pages associated with the given Cell.  Write the
+** local Cell size (the number of bytes on the original page, omitting
+** overflow) into *pnSize.
 */
-static int clearCell(MemPage *pPage, unsigned char *pCell){
+static int clearCell(
+  MemPage *pPage,          /* The page that contains the Cell */
+  unsigned char *pCell,    /* First byte of the Cell */
+  u16 *pnSize              /* Write the size of the Cell here */
+){
   BtShared *pBt = pPage->pBt;
   CellInfo info;
   Pgno ovflPgno;
@@ -53294,18 +64130,21 @@ static int clearCell(MemPage *pPage, unsigned char *pCell){
   u32 ovflPageSize;
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  btreeParseCellPtr(pPage, pCell, &info);
-  if( info.iOverflow==0 ){
+  pPage->xParseCell(pPage, pCell, &info);
+  *pnSize = info.nSize;
+  if( info.nLocal==info.nPayload ){
     return SQLITE_OK;  /* No overflow pages. Return without doing anything */
   }
-  if( pCell+info.iOverflow+3 > pPage->aData+pPage->maskPage ){
-    return SQLITE_CORRUPT;  /* Cell extends past end of page */
+  if( pCell+info.nSize-1 > pPage->aData+pPage->maskPage ){
+    return SQLITE_CORRUPT_BKPT;  /* Cell extends past end of page */
   }
-  ovflPgno = get4byte(&pCell[info.iOverflow]);
+  ovflPgno = get4byte(pCell + info.nSize - 4);
   assert( pBt->usableSize > 4 );
   ovflPageSize = pBt->usableSize - 4;
   nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
-  assert( ovflPgno==0 || nOvfl>0 );
+  assert( nOvfl>0 || 
+    (CORRUPT_DB && (info.nPayload + ovflPageSize)<ovflPageSize)
+  );
   while( nOvfl-- ){
     Pgno iNext = 0;
     MemPage *pOvfl = 0;
@@ -53362,9 +64201,7 @@ static int clearCell(MemPage *pPage, unsigned char *pCell){
 static int fillInCell(
   MemPage *pPage,                /* The page that contains the cell */
   unsigned char *pCell,          /* Complete text of the cell */
-  const void *pKey, i64 nKey,    /* The key */
-  const void *pData,int nData,   /* The data */
-  int nZero,                     /* Extra zero bytes to append to pData */
+  const BtreePayload *pX,        /* Payload with which to construct the cell */
   int *pnSize                    /* Write cell size here */
 ){
   int nPayload;
@@ -53378,7 +64215,6 @@ static int fillInCell(
   BtShared *pBt = pPage->pBt;
   Pgno pgnoOvfl = 0;
   int nHeader;
-  CellInfo info;
 
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
 
@@ -53388,40 +64224,68 @@ static int fillInCell(
             || sqlite3PagerIswriteable(pPage->pDbPage) );
 
   /* Fill in the header. */
-  nHeader = 0;
-  if( !pPage->leaf ){
-    nHeader += 4;
-  }
-  if( pPage->hasData ){
-    nHeader += putVarint(&pCell[nHeader], nData+nZero);
+  nHeader = pPage->childPtrSize;
+  if( pPage->intKey ){
+    nPayload = pX->nData + pX->nZero;
+    pSrc = pX->pData;
+    nSrc = pX->nData;
+    assert( pPage->intKeyLeaf ); /* fillInCell() only called for leaves */
+    nHeader += putVarint32(&pCell[nHeader], nPayload);
+    nHeader += putVarint(&pCell[nHeader], *(u64*)&pX->nKey);
   }else{
-    nData = nZero = 0;
+    assert( pX->nData==0 );
+    assert( pX->nZero==0 );
+    assert( pX->nKey<=0x7fffffff && pX->pKey!=0 );
+    nSrc = nPayload = (int)pX->nKey;
+    pSrc = pX->pKey;
+    nHeader += putVarint32(&pCell[nHeader], nPayload);
   }
-  nHeader += putVarint(&pCell[nHeader], *(u64*)&nKey);
-  btreeParseCellPtr(pPage, pCell, &info);
-  assert( info.nHeader==nHeader );
-  assert( info.nKey==nKey );
-  assert( info.nData==(u32)(nData+nZero) );
   
   /* Fill in the payload */
-  nPayload = nData + nZero;
-  if( pPage->intKey ){
-    pSrc = pData;
-    nSrc = nData;
-    nData = 0;
-  }else{ 
-    if( NEVER(nKey>0x7fffffff || pKey==0) ){
-      return SQLITE_CORRUPT_BKPT;
-    }
-    nPayload += (int)nKey;
-    pSrc = pKey;
-    nSrc = (int)nKey;
+  if( nPayload<=pPage->maxLocal ){
+    n = nHeader + nPayload;
+    testcase( n==3 );
+    testcase( n==4 );
+    if( n<4 ) n = 4;
+    *pnSize = n;
+    spaceLeft = nPayload;
+    pPrior = pCell;
+  }else{
+    int mn = pPage->minLocal;
+    n = mn + (nPayload - mn) % (pPage->pBt->usableSize - 4);
+    testcase( n==pPage->maxLocal );
+    testcase( n==pPage->maxLocal+1 );
+    if( n > pPage->maxLocal ) n = mn;
+    spaceLeft = n;
+    *pnSize = n + nHeader + 4;
+    pPrior = &pCell[nHeader+n];
   }
-  *pnSize = info.nSize;
-  spaceLeft = info.nLocal;
   pPayload = &pCell[nHeader];
-  pPrior = &pCell[info.iOverflow];
 
+  /* At this point variables should be set as follows:
+  **
+  **   nPayload           Total payload size in bytes
+  **   pPayload           Begin writing payload here
+  **   spaceLeft          Space available at pPayload.  If nPayload>spaceLeft,
+  **                      that means content must spill into overflow pages.
+  **   *pnSize            Size of the local cell (not counting overflow pages)
+  **   pPrior             Where to write the pgno of the first overflow page
+  **
+  ** Use a call to btreeParseCellPtr() to verify that the values above
+  ** were computed correctly.
+  */
+#if SQLITE_DEBUG
+  {
+    CellInfo info;
+    pPage->xParseCell(pPage, pCell, &info);
+    assert( nHeader==(int)(info.pPayload - pCell) );
+    assert( info.nKey==pX->nKey );
+    assert( *pnSize == info.nSize );
+    assert( spaceLeft == info.nLocal );
+  }
+#endif
+
+  /* Write the payload into the local Cell and any extra into overflow pages */
   while( nPayload>0 ){
     if( spaceLeft==0 ){
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -53443,7 +64307,7 @@ static int fillInCell(
       ** If this is the first overflow page, then write a partial entry 
       ** to the pointer-map. If we write nothing to this pointer-map slot,
       ** then the optimistic overflow chain processing in clearCell()
-      ** may misinterpret the uninitialised values and delete the
+      ** may misinterpret the uninitialized values and delete the
       ** wrong pages from the database.
       */
       if( pBt->autoVacuum && rc==SQLITE_OK ){
@@ -53500,10 +64364,6 @@ static int fillInCell(
     pSrc += n;
     nSrc -= n;
     spaceLeft -= n;
-    if( nSrc==0 ){
-      nSrc = nData;
-      pSrc = pData;
-    }
   }
   releasePage(pToRelease);
   return SQLITE_OK;
@@ -53521,18 +64381,17 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
   u32 pc;         /* Offset to cell content of cell being deleted */
   u8 *data;       /* pPage->aData */
   u8 *ptr;        /* Used to move bytes around within data[] */
-  u8 *endPtr;     /* End of loop */
   int rc;         /* The return code */
   int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */
 
   if( *pRC ) return;
 
   assert( idx>=0 && idx<pPage->nCell );
-  assert( sz==cellSize(pPage, idx) );
+  assert( CORRUPT_DB || sz==cellSize(pPage, idx) );
   assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   data = pPage->aData;
-  ptr = &data[pPage->cellOffset + 2*idx];
+  ptr = &pPage->aCellIdx[2*idx];
   pc = get2byte(ptr);
   hdr = pPage->hdrOffset;
   testcase( pc==get2byte(&data[hdr+5]) );
@@ -53546,15 +64405,18 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
     *pRC = rc;
     return;
   }
-  endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
-  assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
-  while( ptr<endPtr ){
-    *(u16*)ptr = *(u16*)&ptr[2];
-    ptr += 2;
-  }
   pPage->nCell--;
-  put2byte(&data[hdr+3], pPage->nCell);
-  pPage->nFree += 2;
+  if( pPage->nCell==0 ){
+    memset(&data[hdr+1], 0, 4);
+    data[hdr+7] = 0;
+    put2byte(&data[hdr+5], pPage->pBt->usableSize);
+    pPage->nFree = pPage->pBt->usableSize - pPage->hdrOffset
+                       - pPage->childPtrSize - 8;
+  }else{
+    memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
+    put2byte(&data[hdr+3], pPage->nCell);
+    pPage->nFree += 2;
+  }
 }
 
 /*
@@ -53564,15 +64426,12 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
 ** If the cell content will fit on the page, then put it there.  If it
 ** will not fit, then make a copy of the cell content into pTemp if
 ** pTemp is not null.  Regardless of pTemp, allocate a new entry
-** in pPage->aOvfl[] and make it point to the cell content (either
+** in pPage->apOvfl[] and make it point to the cell content (either
 ** in pTemp or the original pCell) and also record its index. 
 ** Allocating a new entry in pPage->aCell[] implies that 
 ** pPage->nOverflow is incremented.
 **
-** If nSkip is non-zero, then do not copy the first nSkip bytes of the
-** cell. The caller will overwrite them after this function returns. If
-** nSkip is non-zero, then pCell may not point to an invalid memory location 
-** (but pCell+nSkip is always valid).
+** *pRC must be SQLITE_OK when this routine is called.
 */
 static void insertCell(
   MemPage *pPage,   /* Page into which we are copying */
@@ -53585,39 +64444,42 @@ static void insertCell(
 ){
   int idx = 0;      /* Where to write new cell content in data[] */
   int j;            /* Loop counter */
-  int end;          /* First byte past the last cell pointer in data[] */
-  int ins;          /* Index in data[] where new cell pointer is inserted */
-  int cellOffset;   /* Address of first cell pointer in data[] */
   u8 *data;         /* The content of the whole page */
-  u8 *ptr;          /* Used for moving information around in data[] */
-  u8 *endPtr;       /* End of the loop */
-
-  int nSkip = (iChild ? 4 : 0);
-
-  if( *pRC ) return;
+  u8 *pIns;         /* The point in pPage->aCellIdx[] where no cell inserted */
 
+  assert( *pRC==SQLITE_OK );
   assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
-  assert( pPage->nCell<=MX_CELL(pPage->pBt) && MX_CELL(pPage->pBt)<=10921 );
-  assert( pPage->nOverflow<=ArraySize(pPage->aOvfl) );
+  assert( MX_CELL(pPage->pBt)<=10921 );
+  assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );
+  assert( pPage->nOverflow<=ArraySize(pPage->apOvfl) );
+  assert( ArraySize(pPage->apOvfl)==ArraySize(pPage->aiOvfl) );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   /* The cell should normally be sized correctly.  However, when moving a
   ** malformed cell from a leaf page to an interior page, if the cell size
   ** wanted to be less than 4 but got rounded up to 4 on the leaf, then size
   ** might be less than 8 (leaf-size + pointer) on the interior node.  Hence
   ** the term after the || in the following assert(). */
-  assert( sz==cellSizePtr(pPage, pCell) || (sz==8 && iChild>0) );
+  assert( sz==pPage->xCellSize(pPage, pCell) || (sz==8 && iChild>0) );
   if( pPage->nOverflow || sz+2>pPage->nFree ){
     if( pTemp ){
-      memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
+      memcpy(pTemp, pCell, sz);
       pCell = pTemp;
     }
     if( iChild ){
       put4byte(pCell, iChild);
     }
     j = pPage->nOverflow++;
-    assert( j<(int)(sizeof(pPage->aOvfl)/sizeof(pPage->aOvfl[0])) );
-    pPage->aOvfl[j].pCell = pCell;
-    pPage->aOvfl[j].idx = (u16)i;
+    assert( j<(int)(sizeof(pPage->apOvfl)/sizeof(pPage->apOvfl[0])) );
+    pPage->apOvfl[j] = pCell;
+    pPage->aiOvfl[j] = (u16)i;
+
+    /* When multiple overflows occur, they are always sequential and in
+    ** sorted order.  This invariants arise because multiple overflows can
+    ** only occur when inserting divider cells into the parent page during
+    ** balancing, and the dividers are adjacent and sorted.
+    */
+    assert( j==0 || pPage->aiOvfl[j-1]<(u16)i ); /* Overflows in sorted order */
+    assert( j==0 || i==pPage->aiOvfl[j-1]+1 );   /* Overflows are sequential */
   }else{
     int rc = sqlite3PagerWrite(pPage->pDbPage);
     if( rc!=SQLITE_OK ){
@@ -53626,30 +64488,26 @@ static void insertCell(
     }
     assert( sqlite3PagerIswriteable(pPage->pDbPage) );
     data = pPage->aData;
-    cellOffset = pPage->cellOffset;
-    end = cellOffset + 2*pPage->nCell;
-    ins = cellOffset + 2*i;
+    assert( &data[pPage->cellOffset]==pPage->aCellIdx );
     rc = allocateSpace(pPage, sz, &idx);
     if( rc ){ *pRC = rc; return; }
-    /* The allocateSpace() routine guarantees the following two properties
-    ** if it returns success */
-    assert( idx >= end+2 );
+    /* The allocateSpace() routine guarantees the following properties
+    ** if it returns successfully */
+    assert( idx >= 0 );
+    assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );
     assert( idx+sz <= (int)pPage->pBt->usableSize );
-    pPage->nCell++;
     pPage->nFree -= (u16)(2 + sz);
-    memcpy(&data[idx+nSkip], pCell+nSkip, sz-nSkip);
+    memcpy(&data[idx], pCell, sz);
     if( iChild ){
       put4byte(&data[idx], iChild);
     }
-    ptr = &data[end];
-    endPtr = &data[ins];
-    assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
-    while( ptr>endPtr ){
-      *(u16*)ptr = *(u16*)&ptr[-2];
-      ptr -= 2;
-    }
-    put2byte(&data[ins], idx);
-    put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
+    pIns = pPage->aCellIdx + i*2;
+    memmove(pIns+2, pIns, 2*(pPage->nCell - i));
+    put2byte(pIns, idx);
+    pPage->nCell++;
+    /* increment the cell count */
+    if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;
+    assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell );
 #ifndef SQLITE_OMIT_AUTOVACUUM
     if( pPage->pBt->autoVacuum ){
       /* The cell may contain a pointer to an overflow page. If so, write
@@ -53662,45 +64520,328 @@ static void insertCell(
 }
 
 /*
-** Add a list of cells to a page.  The page should be initially empty.
-** The cells are guaranteed to fit on the page.
+** A CellArray object contains a cache of pointers and sizes for a
+** consecutive sequence of cells that might be held on multiple pages.
+*/
+typedef struct CellArray CellArray;
+struct CellArray {
+  int nCell;              /* Number of cells in apCell[] */
+  MemPage *pRef;          /* Reference page */
+  u8 **apCell;            /* All cells begin balanced */
+  u16 *szCell;            /* Local size of all cells in apCell[] */
+};
+
+/*
+** Make sure the cell sizes at idx, idx+1, ..., idx+N-1 have been
+** computed.
 */
-static void assemblePage(
-  MemPage *pPage,   /* The page to be assemblied */
-  int nCell,        /* The number of cells to add to this page */
-  u8 **apCell,      /* Pointers to cell bodies */
-  u16 *aSize        /* Sizes of the cells */
+static void populateCellCache(CellArray *p, int idx, int N){
+  assert( idx>=0 && idx+N<=p->nCell );
+  while( N>0 ){
+    assert( p->apCell[idx]!=0 );
+    if( p->szCell[idx]==0 ){
+      p->szCell[idx] = p->pRef->xCellSize(p->pRef, p->apCell[idx]);
+    }else{
+      assert( CORRUPT_DB ||
+              p->szCell[idx]==p->pRef->xCellSize(p->pRef, p->apCell[idx]) );
+    }
+    idx++;
+    N--;
+  }
+}
+
+/*
+** Return the size of the Nth element of the cell array
+*/
+static SQLITE_NOINLINE u16 computeCellSize(CellArray *p, int N){
+  assert( N>=0 && N<p->nCell );
+  assert( p->szCell[N]==0 );
+  p->szCell[N] = p->pRef->xCellSize(p->pRef, p->apCell[N]);
+  return p->szCell[N];
+}
+static u16 cachedCellSize(CellArray *p, int N){
+  assert( N>=0 && N<p->nCell );
+  if( p->szCell[N] ) return p->szCell[N];
+  return computeCellSize(p, N);
+}
+
+/*
+** Array apCell[] contains pointers to nCell b-tree page cells. The 
+** szCell[] array contains the size in bytes of each cell. This function
+** replaces the current contents of page pPg with the contents of the cell
+** array.
+**
+** Some of the cells in apCell[] may currently be stored in pPg. This
+** function works around problems caused by this by making a copy of any 
+** such cells before overwriting the page data.
+**
+** The MemPage.nFree field is invalidated by this function. It is the 
+** responsibility of the caller to set it correctly.
+*/
+static int rebuildPage(
+  MemPage *pPg,                   /* Edit this page */
+  int nCell,                      /* Final number of cells on page */
+  u8 **apCell,                    /* Array of cells */
+  u16 *szCell                     /* Array of cell sizes */
 ){
-  int i;            /* Loop counter */
-  u8 *pCellptr;     /* Address of next cell pointer */
-  int cellbody;     /* Address of next cell body */
-  u8 * const data = pPage->aData;             /* Pointer to data for pPage */
-  const int hdr = pPage->hdrOffset;           /* Offset of header on pPage */
-  const int nUsable = pPage->pBt->usableSize; /* Usable size of page */
+  const int hdr = pPg->hdrOffset;          /* Offset of header on pPg */
+  u8 * const aData = pPg->aData;           /* Pointer to data for pPg */
+  const int usableSize = pPg->pBt->usableSize;
+  u8 * const pEnd = &aData[usableSize];
+  int i;
+  u8 *pCellptr = pPg->aCellIdx;
+  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
+  u8 *pData;
 
-  assert( pPage->nOverflow==0 );
-  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-  assert( nCell>=0 && nCell<=(int)MX_CELL(pPage->pBt)
-            && (int)MX_CELL(pPage->pBt)<=10921);
-  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  i = get2byte(&aData[hdr+5]);
+  memcpy(&pTmp[i], &aData[i], usableSize - i);
+
+  pData = pEnd;
+  for(i=0; i<nCell; i++){
+    u8 *pCell = apCell[i];
+    if( SQLITE_WITHIN(pCell,aData,pEnd) ){
+      pCell = &pTmp[pCell - aData];
+    }
+    pData -= szCell[i];
+    put2byte(pCellptr, (pData - aData));
+    pCellptr += 2;
+    if( pData < pCellptr ) return SQLITE_CORRUPT_BKPT;
+    memcpy(pData, pCell, szCell[i]);
+    assert( szCell[i]==pPg->xCellSize(pPg, pCell) || CORRUPT_DB );
+    testcase( szCell[i]!=pPg->xCellSize(pPg,pCell) );
+  }
+
+  /* The pPg->nFree field is now set incorrectly. The caller will fix it. */
+  pPg->nCell = nCell;
+  pPg->nOverflow = 0;
+
+  put2byte(&aData[hdr+1], 0);
+  put2byte(&aData[hdr+3], pPg->nCell);
+  put2byte(&aData[hdr+5], pData - aData);
+  aData[hdr+7] = 0x00;
+  return SQLITE_OK;
+}
+
+/*
+** Array apCell[] contains nCell pointers to b-tree cells. Array szCell
+** contains the size in bytes of each such cell. This function attempts to 
+** add the cells stored in the array to page pPg. If it cannot (because 
+** the page needs to be defragmented before the cells will fit), non-zero
+** is returned. Otherwise, if the cells are added successfully, zero is
+** returned.
+**
+** Argument pCellptr points to the first entry in the cell-pointer array
+** (part of page pPg) to populate. After cell apCell[0] is written to the
+** page body, a 16-bit offset is written to pCellptr. And so on, for each
+** cell in the array. It is the responsibility of the caller to ensure
+** that it is safe to overwrite this part of the cell-pointer array.
+**
+** When this function is called, *ppData points to the start of the 
+** content area on page pPg. If the size of the content area is extended,
+** *ppData is updated to point to the new start of the content area
+** before returning.
+**
+** Finally, argument pBegin points to the byte immediately following the
+** end of the space required by this page for the cell-pointer area (for
+** all cells - not just those inserted by the current call). If the content
+** area must be extended to before this point in order to accomodate all
+** cells in apCell[], then the cells do not fit and non-zero is returned.
+*/
+static int pageInsertArray(
+  MemPage *pPg,                   /* Page to add cells to */
+  u8 *pBegin,                     /* End of cell-pointer array */
+  u8 **ppData,                    /* IN/OUT: Page content -area pointer */
+  u8 *pCellptr,                   /* Pointer to cell-pointer area */
+  int iFirst,                     /* Index of first cell to add */
+  int nCell,                      /* Number of cells to add to pPg */
+  CellArray *pCArray              /* Array of cells */
+){
+  int i;
+  u8 *aData = pPg->aData;
+  u8 *pData = *ppData;
+  int iEnd = iFirst + nCell;
+  assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */
+  for(i=iFirst; i<iEnd; i++){
+    int sz, rc;
+    u8 *pSlot;
+    sz = cachedCellSize(pCArray, i);
+    if( (aData[1]==0 && aData[2]==0) || (pSlot = pageFindSlot(pPg,sz,&rc))==0 ){
+      if( (pData - pBegin)<sz ) return 1;
+      pData -= sz;
+      pSlot = pData;
+    }
+    /* pSlot and pCArray->apCell[i] will never overlap on a well-formed
+    ** database.  But they might for a corrupt database.  Hence use memmove()
+    ** since memcpy() sends SIGABORT with overlapping buffers on OpenBSD */
+    assert( (pSlot+sz)<=pCArray->apCell[i]
+         || pSlot>=(pCArray->apCell[i]+sz)
+         || CORRUPT_DB );
+    memmove(pSlot, pCArray->apCell[i], sz);
+    put2byte(pCellptr, (pSlot - aData));
+    pCellptr += 2;
+  }
+  *ppData = pData;
+  return 0;
+}
+
+/*
+** Array apCell[] contains nCell pointers to b-tree cells. Array szCell 
+** contains the size in bytes of each such cell. This function adds the
+** space associated with each cell in the array that is currently stored 
+** within the body of pPg to the pPg free-list. The cell-pointers and other
+** fields of the page are not updated.
+**
+** This function returns the total number of cells added to the free-list.
+*/
+static int pageFreeArray(
+  MemPage *pPg,                   /* Page to edit */
+  int iFirst,                     /* First cell to delete */
+  int nCell,                      /* Cells to delete */
+  CellArray *pCArray              /* Array of cells */
+){
+  u8 * const aData = pPg->aData;
+  u8 * const pEnd = &aData[pPg->pBt->usableSize];
+  u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];
+  int nRet = 0;
+  int i;
+  int iEnd = iFirst + nCell;
+  u8 *pFree = 0;
+  int szFree = 0;
+
+  for(i=iFirst; i<iEnd; i++){
+    u8 *pCell = pCArray->apCell[i];
+    if( SQLITE_WITHIN(pCell, pStart, pEnd) ){
+      int sz;
+      /* No need to use cachedCellSize() here.  The sizes of all cells that
+      ** are to be freed have already been computing while deciding which
+      ** cells need freeing */
+      sz = pCArray->szCell[i];  assert( sz>0 );
+      if( pFree!=(pCell + sz) ){
+        if( pFree ){
+          assert( pFree>aData && (pFree - aData)<65536 );
+          freeSpace(pPg, (u16)(pFree - aData), szFree);
+        }
+        pFree = pCell;
+        szFree = sz;
+        if( pFree+sz>pEnd ) return 0;
+      }else{
+        pFree = pCell;
+        szFree += sz;
+      }
+      nRet++;
+    }
+  }
+  if( pFree ){
+    assert( pFree>aData && (pFree - aData)<65536 );
+    freeSpace(pPg, (u16)(pFree - aData), szFree);
+  }
+  return nRet;
+}
 
-  /* Check that the page has just been zeroed by zeroPage() */
-  assert( pPage->nCell==0 );
-  assert( get2byteNotZero(&data[hdr+5])==nUsable );
+/*
+** apCell[] and szCell[] contains pointers to and sizes of all cells in the
+** pages being balanced.  The current page, pPg, has pPg->nCell cells starting
+** with apCell[iOld].  After balancing, this page should hold nNew cells
+** starting at apCell[iNew].
+**
+** This routine makes the necessary adjustments to pPg so that it contains
+** the correct cells after being balanced.
+**
+** The pPg->nFree field is invalid when this function returns. It is the
+** responsibility of the caller to set it correctly.
+*/
+static int editPage(
+  MemPage *pPg,                   /* Edit this page */
+  int iOld,                       /* Index of first cell currently on page */
+  int iNew,                       /* Index of new first cell on page */
+  int nNew,                       /* Final number of cells on page */
+  CellArray *pCArray              /* Array of cells and sizes */
+){
+  u8 * const aData = pPg->aData;
+  const int hdr = pPg->hdrOffset;
+  u8 *pBegin = &pPg->aCellIdx[nNew * 2];
+  int nCell = pPg->nCell;       /* Cells stored on pPg */
+  u8 *pData;
+  u8 *pCellptr;
+  int i;
+  int iOldEnd = iOld + pPg->nCell + pPg->nOverflow;
+  int iNewEnd = iNew + nNew;
 
-  pCellptr = &data[pPage->cellOffset + nCell*2];
-  cellbody = nUsable;
-  for(i=nCell-1; i>=0; i--){
-    u16 sz = aSize[i];
-    pCellptr -= 2;
-    cellbody -= sz;
-    put2byte(pCellptr, cellbody);
-    memcpy(&data[cellbody], apCell[i], sz);
+#ifdef SQLITE_DEBUG
+  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
+  memcpy(pTmp, aData, pPg->pBt->usableSize);
+#endif
+
+  /* Remove cells from the start and end of the page */
+  if( iOld<iNew ){
+    int nShift = pageFreeArray(pPg, iOld, iNew-iOld, pCArray);
+    memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
+    nCell -= nShift;
+  }
+  if( iNewEnd < iOldEnd ){
+    nCell -= pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
+  }
+
+  pData = &aData[get2byteNotZero(&aData[hdr+5])];
+  if( pData<pBegin ) goto editpage_fail;
+
+  /* Add cells to the start of the page */
+  if( iNew<iOld ){
+    int nAdd = MIN(nNew,iOld-iNew);
+    assert( (iOld-iNew)<nNew || nCell==0 || CORRUPT_DB );
+    pCellptr = pPg->aCellIdx;
+    memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
+    if( pageInsertArray(
+          pPg, pBegin, &pData, pCellptr,
+          iNew, nAdd, pCArray
+    ) ) goto editpage_fail;
+    nCell += nAdd;
+  }
+
+  /* Add any overflow cells */
+  for(i=0; i<pPg->nOverflow; i++){
+    int iCell = (iOld + pPg->aiOvfl[i]) - iNew;
+    if( iCell>=0 && iCell<nNew ){
+      pCellptr = &pPg->aCellIdx[iCell * 2];
+      memmove(&pCellptr[2], pCellptr, (nCell - iCell) * 2);
+      nCell++;
+      if( pageInsertArray(
+            pPg, pBegin, &pData, pCellptr,
+            iCell+iNew, 1, pCArray
+      ) ) goto editpage_fail;
+    }
   }
-  put2byte(&data[hdr+3], nCell);
-  put2byte(&data[hdr+5], cellbody);
-  pPage->nFree -= (nCell*2 + nUsable - cellbody);
-  pPage->nCell = (u16)nCell;
+
+  /* Append cells to the end of the page */
+  pCellptr = &pPg->aCellIdx[nCell*2];
+  if( pageInsertArray(
+        pPg, pBegin, &pData, pCellptr,
+        iNew+nCell, nNew-nCell, pCArray
+  ) ) goto editpage_fail;
+
+  pPg->nCell = nNew;
+  pPg->nOverflow = 0;
+
+  put2byte(&aData[hdr+3], pPg->nCell);
+  put2byte(&aData[hdr+5], pData - aData);
+
+#ifdef SQLITE_DEBUG
+  for(i=0; i<nNew && !CORRUPT_DB; i++){
+    u8 *pCell = pCArray->apCell[i+iNew];
+    int iOff = get2byteAligned(&pPg->aCellIdx[i*2]);
+    if( SQLITE_WITHIN(pCell, aData, &aData[pPg->pBt->usableSize]) ){
+      pCell = &pTmp[pCell - aData];
+    }
+    assert( 0==memcmp(pCell, &aData[iOff],
+            pCArray->pRef->xCellSize(pCArray->pRef, pCArray->apCell[i+iNew])) );
+  }
+#endif
+
+  return SQLITE_OK;
+ editpage_fail:
+  /* Unable to edit this page. Rebuild it from scratch instead. */
+  populateCellCache(pCArray, iNew, nNew);
+  return rebuildPage(pPg, nNew, &pCArray->apCell[iNew], &pCArray->szCell[iNew]);
 }
 
 /*
@@ -53754,7 +64895,7 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
   assert( pPage->nOverflow==1 );
 
   /* This error condition is now caught prior to reaching this function */
-  if( pPage->nCell<=0 ) return SQLITE_CORRUPT_BKPT;
+  if( NEVER(pPage->nCell==0) ) return SQLITE_CORRUPT_BKPT;
 
   /* Allocate a new page. This page will become the right-sibling of 
   ** pPage. Make the parent page writable, so that the new divider cell
@@ -53765,14 +64906,16 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
   if( rc==SQLITE_OK ){
 
     u8 *pOut = &pSpace[4];
-    u8 *pCell = pPage->aOvfl[0].pCell;
-    u16 szCell = cellSizePtr(pPage, pCell);
+    u8 *pCell = pPage->apOvfl[0];
+    u16 szCell = pPage->xCellSize(pPage, pCell);
     u8 *pStop;
 
     assert( sqlite3PagerIswriteable(pNew->pDbPage) );
     assert( pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
     zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
-    assemblePage(pNew, 1, &pCell, &szCell);
+    rc = rebuildPage(pNew, 1, &pCell, &szCell);
+    if( NEVER(rc) ) return rc;
+    pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;
 
     /* If this is an auto-vacuum database, update the pointer map
     ** with entries for the new page, and any pointer from the 
@@ -53810,8 +64953,10 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
     while( ((*(pOut++) = *(pCell++))&0x80) && pCell<pStop );
 
     /* Insert the new divider cell into pParent. */
-    insertCell(pParent, pParent->nCell, pSpace, (int)(pOut-pSpace),
-               0, pPage->pgno, &rc);
+    if( rc==SQLITE_OK ){
+      insertCell(pParent, pParent->nCell, pSpace, (int)(pOut-pSpace),
+                   0, pPage->pgno, &rc);
+    }
 
     /* Set the right-child pointer of pParent to point to the new page. */
     put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);
@@ -53844,9 +64989,9 @@ static int ptrmapCheckPages(MemPage **apPage, int nPage){
       u8 *z;
      
       z = findCell(pPage, j);
-      btreeParseCellPtr(pPage, z, &info);
-      if( info.iOverflow ){
-        Pgno ovfl = get4byte(&z[info.iOverflow]);
+      pPage->xParseCell(pPage, z, &info);
+      if( info.nLocal<info.nPayload ){
+        Pgno ovfl = get4byte(&z[info.nSize-4]);
         ptrmapGet(pBt, ovfl, &e, &n);
         assert( n==pPage->pgno && e==PTRMAP_OVERFLOW1 );
       }
@@ -53875,7 +65020,7 @@ static int ptrmapCheckPages(MemPage **apPage, int nPage){
 ** map entries are also updated so that the parent page is page pTo.
 **
 ** If pFrom is currently carrying any overflow cells (entries in the
-** MemPage.aOvfl[] array), they are not copied to pTo. 
+** MemPage.apOvfl[] array), they are not copied to pTo. 
 **
 ** Before returning, page pTo is reinitialized using btreeInitPage().
 **
@@ -53968,10 +65113,10 @@ static int balance_nonroot(
   MemPage *pParent,               /* Parent page of siblings being balanced */
   int iParentIdx,                 /* Index of "the page" in pParent */
   u8 *aOvflSpace,                 /* page-size bytes of space for parent ovfl */
-  int isRoot                      /* True if pParent is a root-page */
+  int isRoot,                     /* True if pParent is a root-page */
+  int bBulk                       /* True if this call is part of a bulk load */
 ){
   BtShared *pBt;               /* The whole database */
-  int nCell = 0;               /* Number of cells in apCell[] */
   int nMaxCells = 0;           /* Allocated size of apCell, szCell, aFrom. */
   int nNew = 0;                /* Number of pages in apNew[] */
   int nOld;                    /* Number of pages in apOld[] */
@@ -53982,22 +65127,27 @@ static int balance_nonroot(
   int leafData;                /* True if pPage is a leaf of a LEAFDATA tree */
   int usableSpace;             /* Bytes in pPage beyond the header */
   int pageFlags;               /* Value of pPage->aData[0] */
-  int subtotal;                /* Subtotal of bytes in cells on one page */
   int iSpace1 = 0;             /* First unused byte of aSpace1[] */
   int iOvflSpace = 0;          /* First unused byte of aOvflSpace[] */
   int szScratch;               /* Size of scratch memory requested */
   MemPage *apOld[NB];          /* pPage and up to two siblings */
-  MemPage *apCopy[NB];         /* Private copies of apOld[] pages */
   MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */
   u8 *pRight;                  /* Location in parent of right-sibling pointer */
   u8 *apDiv[NB-1];             /* Divider cells in pParent */
-  int cntNew[NB+2];            /* Index in aCell[] of cell after i-th page */
-  int szNew[NB+2];             /* Combined size of cells place on i-th page */
-  u8 **apCell = 0;             /* All cells begin balanced */
-  u16 *szCell;                 /* Local size of all cells in apCell[] */
+  int cntNew[NB+2];            /* Index in b.paCell[] of cell after i-th page */
+  int cntOld[NB+2];            /* Old index in b.apCell[] */
+  int szNew[NB+2];             /* Combined size of cells placed on i-th page */
   u8 *aSpace1;                 /* Space for copies of dividers cells */
   Pgno pgno;                   /* Temp var to store a page number in */
-
+  u8 abDone[NB+2];             /* True after i'th new page is populated */
+  Pgno aPgno[NB+2];            /* Page numbers of new pages before shuffling */
+  Pgno aPgOrder[NB+2];         /* Copy of aPgno[] used for sorting pages */
+  u16 aPgFlags[NB+2];          /* flags field of new pages before shuffling */
+  CellArray b;                  /* Parsed information on cells being balanced */
+
+  memset(abDone, 0, sizeof(abDone));
+  b.nCell = 0;
+  b.apCell = 0;
   pBt = pParent->pBt;
   assert( sqlite3_mutex_held(pBt->mutex) );
   assert( sqlite3PagerIswriteable(pParent->pDbPage) );
@@ -54012,10 +65162,10 @@ static int balance_nonroot(
   ** is called (indirectly) from sqlite3BtreeDelete().
   */
   assert( pParent->nOverflow==0 || pParent->nOverflow==1 );
-  assert( pParent->nOverflow==0 || pParent->aOvfl[0].idx==iParentIdx );
+  assert( pParent->nOverflow==0 || pParent->aiOvfl[0]==iParentIdx );
 
   if( !aOvflSpace ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   /* Find the sibling pages to balance. Also locate the cells in pParent 
@@ -54032,18 +65182,18 @@ static int balance_nonroot(
   i = pParent->nOverflow + pParent->nCell;
   if( i<2 ){
     nxDiv = 0;
-    nOld = i+1;
   }else{
-    nOld = 3;
+    assert( bBulk==0 || bBulk==1 );
     if( iParentIdx==0 ){                 
       nxDiv = 0;
     }else if( iParentIdx==i ){
-      nxDiv = i-2;
+      nxDiv = i-2+bBulk;
     }else{
       nxDiv = iParentIdx-1;
     }
-    i = 2;
+    i = 2-bBulk;
   }
+  nOld = i+1;
   if( (i+nxDiv-pParent->nOverflow)==pParent->nCell ){
     pRight = &pParent->aData[pParent->hdrOffset+8];
   }else{
@@ -54051,7 +65201,7 @@ static int balance_nonroot(
   }
   pgno = get4byte(pRight);
   while( 1 ){
-    rc = getAndInitPage(pBt, pgno, &apOld[i]);
+    rc = getAndInitPage(pBt, pgno, &apOld[i], 0, 0);
     if( rc ){
       memset(apOld, 0, (i+1)*sizeof(MemPage*));
       goto balance_cleanup;
@@ -54059,15 +65209,15 @@ static int balance_nonroot(
     nMaxCells += 1+apOld[i]->nCell+apOld[i]->nOverflow;
     if( (i--)==0 ) break;
 
-    if( i+nxDiv==pParent->aOvfl[0].idx && pParent->nOverflow ){
-      apDiv[i] = pParent->aOvfl[0].pCell;
+    if( i+nxDiv==pParent->aiOvfl[0] && pParent->nOverflow ){
+      apDiv[i] = pParent->apOvfl[0];
       pgno = get4byte(apDiv[i]);
-      szNew[i] = cellSizePtr(pParent, apDiv[i]);
+      szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
       pParent->nOverflow = 0;
     }else{
       apDiv[i] = findCell(pParent, i+nxDiv-pParent->nOverflow);
       pgno = get4byte(apDiv[i]);
-      szNew[i] = cellSizePtr(pParent, apDiv[i]);
+      szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
 
       /* Drop the cell from the parent page. apDiv[i] still points to
       ** the cell within the parent, even though it has been dropped.
@@ -54081,7 +65231,7 @@ static int balance_nonroot(
       ** In this case, temporarily copy the cell into the aOvflSpace[]
       ** buffer. It will be copied out again as soon as the aSpace[] buffer
       ** is allocated.  */
-      if( pBt->secureDelete ){
+      if( pBt->btsFlags & BTS_SECURE_DELETE ){
         int iOff;
 
         iOff = SQLITE_PTR_TO_INT(apDiv[i]) - SQLITE_PTR_TO_INT(pParent->aData);
@@ -54105,138 +65255,208 @@ static int balance_nonroot(
   /*
   ** Allocate space for memory structures
   */
-  k = pBt->pageSize + ROUND8(sizeof(MemPage));
   szScratch =
-       nMaxCells*sizeof(u8*)                       /* apCell */
-     + nMaxCells*sizeof(u16)                       /* szCell */
-     + pBt->pageSize                               /* aSpace1 */
-     + k*nOld;                                     /* Page copies (apCopy) */
-  apCell = sqlite3ScratchMalloc( szScratch ); 
-  if( apCell==0 ){
-    rc = SQLITE_NOMEM;
+       nMaxCells*sizeof(u8*)                       /* b.apCell */
+     + nMaxCells*sizeof(u16)                       /* b.szCell */
+     + pBt->pageSize;                              /* aSpace1 */
+
+  /* EVIDENCE-OF: R-28375-38319 SQLite will never request a scratch buffer
+  ** that is more than 6 times the database page size. */
+  assert( szScratch<=6*(int)pBt->pageSize );
+  b.apCell = sqlite3ScratchMalloc( szScratch ); 
+  if( b.apCell==0 ){
+    rc = SQLITE_NOMEM_BKPT;
     goto balance_cleanup;
   }
-  szCell = (u16*)&apCell[nMaxCells];
-  aSpace1 = (u8*)&szCell[nMaxCells];
+  b.szCell = (u16*)&b.apCell[nMaxCells];
+  aSpace1 = (u8*)&b.szCell[nMaxCells];
   assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );
 
   /*
   ** Load pointers to all cells on sibling pages and the divider cells
-  ** into the local apCell[] array.  Make copies of the divider cells
-  ** into space obtained from aSpace1[] and remove the the divider Cells
-  ** from pParent.
+  ** into the local b.apCell[] array.  Make copies of the divider cells
+  ** into space obtained from aSpace1[]. The divider cells have already
+  ** been removed from pParent.
   **
   ** If the siblings are on leaf pages, then the child pointers of the
   ** divider cells are stripped from the cells before they are copied
-  ** into aSpace1[].  In this way, all cells in apCell[] are without
+  ** into aSpace1[].  In this way, all cells in b.apCell[] are without
   ** child pointers.  If siblings are not leaves, then all cell in
-  ** apCell[] include child pointers.  Either way, all cells in apCell[]
+  ** b.apCell[] include child pointers.  Either way, all cells in b.apCell[]
   ** are alike.
   **
   ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.
   **       leafData:  1 if pPage holds key+data and pParent holds only keys.
   */
-  leafCorrection = apOld[0]->leaf*4;
-  leafData = apOld[0]->hasData;
+  b.pRef = apOld[0];
+  leafCorrection = b.pRef->leaf*4;
+  leafData = b.pRef->intKeyLeaf;
   for(i=0; i<nOld; i++){
-    int limit;
-    
-    /* Before doing anything else, take a copy of the i'th original sibling
-    ** The rest of this function will use data from the copies rather
-    ** that the original pages since the original pages will be in the
-    ** process of being overwritten.  */
-    MemPage *pOld = apCopy[i] = (MemPage*)&aSpace1[pBt->pageSize + k*i];
-    memcpy(pOld, apOld[i], sizeof(MemPage));
-    pOld->aData = (void*)&pOld[1];
-    memcpy(pOld->aData, apOld[i]->aData, pBt->pageSize);
-
-    limit = pOld->nCell+pOld->nOverflow;
+    MemPage *pOld = apOld[i];
+    int limit = pOld->nCell;
+    u8 *aData = pOld->aData;
+    u16 maskPage = pOld->maskPage;
+    u8 *piCell = aData + pOld->cellOffset;
+    u8 *piEnd;
+
+    /* Verify that all sibling pages are of the same "type" (table-leaf,
+    ** table-interior, index-leaf, or index-interior).
+    */
+    if( pOld->aData[0]!=apOld[0]->aData[0] ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
+
+    /* Load b.apCell[] with pointers to all cells in pOld.  If pOld
+    ** constains overflow cells, include them in the b.apCell[] array
+    ** in the correct spot.
+    **
+    ** Note that when there are multiple overflow cells, it is always the
+    ** case that they are sequential and adjacent.  This invariant arises
+    ** because multiple overflows can only occurs when inserting divider
+    ** cells into a parent on a prior balance, and divider cells are always
+    ** adjacent and are inserted in order.  There is an assert() tagged
+    ** with "NOTE 1" in the overflow cell insertion loop to prove this
+    ** invariant.
+    **
+    ** This must be done in advance.  Once the balance starts, the cell
+    ** offset section of the btree page will be overwritten and we will no
+    ** long be able to find the cells if a pointer to each cell is not saved
+    ** first.
+    */
+    memset(&b.szCell[b.nCell], 0, sizeof(b.szCell[0])*(limit+pOld->nOverflow));
     if( pOld->nOverflow>0 ){
+      limit = pOld->aiOvfl[0];
       for(j=0; j<limit; j++){
-        assert( nCell<nMaxCells );
-        apCell[nCell] = findOverflowCell(pOld, j);
-        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
-        nCell++;
+        b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));
+        piCell += 2;
+        b.nCell++;
       }
-    }else{
-      u8 *aData = pOld->aData;
-      u16 maskPage = pOld->maskPage;
-      u16 cellOffset = pOld->cellOffset;
-      for(j=0; j<limit; j++){
-        assert( nCell<nMaxCells );
-        apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
-        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
-        nCell++;
+      for(k=0; k<pOld->nOverflow; k++){
+        assert( k==0 || pOld->aiOvfl[k-1]+1==pOld->aiOvfl[k] );/* NOTE 1 */
+        b.apCell[b.nCell] = pOld->apOvfl[k];
+        b.nCell++;
       }
-    }       
+    }
+    piEnd = aData + pOld->cellOffset + 2*pOld->nCell;
+    while( piCell<piEnd ){
+      assert( b.nCell<nMaxCells );
+      b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));
+      piCell += 2;
+      b.nCell++;
+    }
+
+    cntOld[i] = b.nCell;
     if( i<nOld-1 && !leafData){
       u16 sz = (u16)szNew[i];
       u8 *pTemp;
-      assert( nCell<nMaxCells );
-      szCell[nCell] = sz;
+      assert( b.nCell<nMaxCells );
+      b.szCell[b.nCell] = sz;
       pTemp = &aSpace1[iSpace1];
       iSpace1 += sz;
       assert( sz<=pBt->maxLocal+23 );
       assert( iSpace1 <= (int)pBt->pageSize );
       memcpy(pTemp, apDiv[i], sz);
-      apCell[nCell] = pTemp+leafCorrection;
+      b.apCell[b.nCell] = pTemp+leafCorrection;
       assert( leafCorrection==0 || leafCorrection==4 );
-      szCell[nCell] = szCell[nCell] - leafCorrection;
+      b.szCell[b.nCell] = b.szCell[b.nCell] - leafCorrection;
       if( !pOld->leaf ){
         assert( leafCorrection==0 );
         assert( pOld->hdrOffset==0 );
         /* The right pointer of the child page pOld becomes the left
         ** pointer of the divider cell */
-        memcpy(apCell[nCell], &pOld->aData[8], 4);
+        memcpy(b.apCell[b.nCell], &pOld->aData[8], 4);
       }else{
         assert( leafCorrection==4 );
-        if( szCell[nCell]<4 ){
-          /* Do not allow any cells smaller than 4 bytes. */
-          szCell[nCell] = 4;
+        while( b.szCell[b.nCell]<4 ){
+          /* Do not allow any cells smaller than 4 bytes. If a smaller cell
+          ** does exist, pad it with 0x00 bytes. */
+          assert( b.szCell[b.nCell]==3 || CORRUPT_DB );
+          assert( b.apCell[b.nCell]==&aSpace1[iSpace1-3] || CORRUPT_DB );
+          aSpace1[iSpace1++] = 0x00;
+          b.szCell[b.nCell]++;
         }
       }
-      nCell++;
+      b.nCell++;
     }
   }
 
   /*
-  ** Figure out the number of pages needed to hold all nCell cells.
+  ** Figure out the number of pages needed to hold all b.nCell cells.
   ** Store this number in "k".  Also compute szNew[] which is the total
   ** size of all cells on the i-th page and cntNew[] which is the index
-  ** in apCell[] of the cell that divides page i from page i+1.  
-  ** cntNew[k] should equal nCell.
+  ** in b.apCell[] of the cell that divides page i from page i+1.  
+  ** cntNew[k] should equal b.nCell.
   **
   ** Values computed by this block:
   **
   **           k: The total number of sibling pages
   **    szNew[i]: Spaced used on the i-th sibling page.
-  **   cntNew[i]: Index in apCell[] and szCell[] for the first cell to
+  **   cntNew[i]: Index in b.apCell[] and b.szCell[] for the first cell to
   **              the right of the i-th sibling page.
   ** usableSpace: Number of bytes of space available on each sibling.
   ** 
   */
   usableSpace = pBt->usableSize - 12 + leafCorrection;
-  for(subtotal=k=i=0; i<nCell; i++){
-    assert( i<nMaxCells );
-    subtotal += szCell[i] + 2;
-    if( subtotal > usableSpace ){
-      szNew[k] = subtotal - szCell[i];
-      cntNew[k] = i;
-      if( leafData ){ i--; }
-      subtotal = 0;
-      k++;
-      if( k>NB+1 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
-    }
-  }
-  szNew[k] = subtotal;
-  cntNew[k] = nCell;
-  k++;
+  for(i=0; i<nOld; i++){
+    MemPage *p = apOld[i];
+    szNew[i] = usableSpace - p->nFree;
+    if( szNew[i]<0 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
+    for(j=0; j<p->nOverflow; j++){
+      szNew[i] += 2 + p->xCellSize(p, p->apOvfl[j]);
+    }
+    cntNew[i] = cntOld[i];
+  }
+  k = nOld;
+  for(i=0; i<k; i++){
+    int sz;
+    while( szNew[i]>usableSpace ){
+      if( i+1>=k ){
+        k = i+2;
+        if( k>NB+2 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
+        szNew[k-1] = 0;
+        cntNew[k-1] = b.nCell;
+      }
+      sz = 2 + cachedCellSize(&b, cntNew[i]-1);
+      szNew[i] -= sz;
+      if( !leafData ){
+        if( cntNew[i]<b.nCell ){
+          sz = 2 + cachedCellSize(&b, cntNew[i]);
+        }else{
+          sz = 0;
+        }
+      }
+      szNew[i+1] += sz;
+      cntNew[i]--;
+    }
+    while( cntNew[i]<b.nCell ){
+      sz = 2 + cachedCellSize(&b, cntNew[i]);
+      if( szNew[i]+sz>usableSpace ) break;
+      szNew[i] += sz;
+      cntNew[i]++;
+      if( !leafData ){
+        if( cntNew[i]<b.nCell ){
+          sz = 2 + cachedCellSize(&b, cntNew[i]);
+        }else{
+          sz = 0;
+        }
+      }
+      szNew[i+1] -= sz;
+    }
+    if( cntNew[i]>=b.nCell ){
+      k = i+1;
+    }else if( cntNew[i] <= (i>0 ? cntNew[i-1] : 0) ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
+  }
 
   /*
   ** The packing computed by the previous block is biased toward the siblings
-  ** on the left side.  The left siblings are always nearly full, while the
-  ** right-most sibling might be nearly empty.  This block of code attempts
-  ** to adjust the packing of siblings to get a better balance.
+  ** on the left side (siblings with smaller keys). The left siblings are
+  ** always nearly full, while the right-most sibling might be nearly empty.
+  ** The next block of code attempts to adjust the packing of siblings to
+  ** get a better balance.
   **
   ** This adjustment is more than an optimization.  The packing above might
   ** be so out of balance as to be illegal.  For example, the right-most
@@ -54250,38 +65470,46 @@ static int balance_nonroot(
 
     r = cntNew[i-1] - 1;
     d = r + 1 - leafData;
-    assert( d<nMaxCells );
-    assert( r<nMaxCells );
-    while( szRight==0 || szRight+szCell[d]+2<=szLeft-(szCell[r]+2) ){
-      szRight += szCell[d] + 2;
-      szLeft -= szCell[r] + 2;
-      cntNew[i-1]--;
-      r = cntNew[i-1] - 1;
-      d = r + 1 - leafData;
-    }
+    (void)cachedCellSize(&b, d);
+    do{
+      assert( d<nMaxCells );
+      assert( r<nMaxCells );
+      (void)cachedCellSize(&b, r);
+      if( szRight!=0
+       && (bBulk || szRight+b.szCell[d]+2 > szLeft-(b.szCell[r]+(i==k-1?0:2)))){
+        break;
+      }
+      szRight += b.szCell[d] + 2;
+      szLeft -= b.szCell[r] + 2;
+      cntNew[i-1] = r;
+      r--;
+      d--;
+    }while( r>=0 );
     szNew[i] = szRight;
     szNew[i-1] = szLeft;
+    if( cntNew[i-1] <= (i>1 ? cntNew[i-2] : 0) ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto balance_cleanup;
+    }
   }
 
-  /* Either we found one or more cells (cntnew[0])>0) or pPage is
-  ** a virtual root page.  A virtual root page is when the real root
-  ** page is page 1 and we are the only child of that page.
+  /* Sanity check:  For a non-corrupt database file one of the follwing
+  ** must be true:
+  **    (1) We found one or more cells (cntNew[0])>0), or
+  **    (2) pPage is a virtual root page.  A virtual root page is when
+  **        the real root page is page 1 and we are the only child of
+  **        that page.
   */
-  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) );
-
-  TRACE(("BALANCE: old: %d %d %d  ",
-    apOld[0]->pgno, 
-    nOld>=2 ? apOld[1]->pgno : 0,
-    nOld>=3 ? apOld[2]->pgno : 0
+  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) || CORRUPT_DB);
+  TRACE(("BALANCE: old: %d(nc=%d) %d(nc=%d) %d(nc=%d)\n",
+    apOld[0]->pgno, apOld[0]->nCell,
+    nOld>=2 ? apOld[1]->pgno : 0, nOld>=2 ? apOld[1]->nCell : 0,
+    nOld>=3 ? apOld[2]->pgno : 0, nOld>=3 ? apOld[2]->nCell : 0
   ));
 
   /*
   ** Allocate k new pages.  Reuse old pages where possible.
   */
-  if( apOld[0]->pgno<=1 ){
-    rc = SQLITE_CORRUPT_BKPT;
-    goto balance_cleanup;
-  }
   pageFlags = apOld[0]->aData[0];
   for(i=0; i<k; i++){
     MemPage *pNew;
@@ -54293,10 +65521,12 @@ static int balance_nonroot(
       if( rc ) goto balance_cleanup;
     }else{
       assert( i>0 );
-      rc = allocateBtreePage(pBt, &pNew, &pgno, pgno, 0);
+      rc = allocateBtreePage(pBt, &pNew, &pgno, (bBulk ? 1 : pgno), 0);
       if( rc ) goto balance_cleanup;
+      zeroPage(pNew, pageFlags);
       apNew[i] = pNew;
       nNew++;
+      cntOld[i] = b.nCell;
 
       /* Set the pointer-map entry for the new sibling page. */
       if( ISAUTOVACUUM ){
@@ -54308,135 +65538,249 @@ static int balance_nonroot(
     }
   }
 
-  /* Free any old pages that were not reused as new pages.
-  */
-  while( i<nOld ){
-    freePage(apOld[i], &rc);
-    if( rc ) goto balance_cleanup;
-    releasePage(apOld[i]);
-    apOld[i] = 0;
-    i++;
-  }
-
   /*
-  ** Put the new pages in accending order.  This helps to
-  ** keep entries in the disk file in order so that a scan
-  ** of the table is a linear scan through the file.  That
-  ** in turn helps the operating system to deliver pages
-  ** from the disk more rapidly.
+  ** Reassign page numbers so that the new pages are in ascending order. 
+  ** This helps to keep entries in the disk file in order so that a scan
+  ** of the table is closer to a linear scan through the file. That in turn 
+  ** helps the operating system to deliver pages from the disk more rapidly.
   **
-  ** An O(n^2) insertion sort algorithm is used, but since
-  ** n is never more than NB (a small constant), that should
-  ** not be a problem.
+  ** An O(n^2) insertion sort algorithm is used, but since n is never more 
+  ** than (NB+2) (a small constant), that should not be a problem.
   **
-  ** When NB==3, this one optimization makes the database
-  ** about 25% faster for large insertions and deletions.
+  ** When NB==3, this one optimization makes the database about 25% faster 
+  ** for large insertions and deletions.
   */
-  for(i=0; i<k-1; i++){
-    int minV = apNew[i]->pgno;
-    int minI = i;
-    for(j=i+1; j<k; j++){
-      if( apNew[j]->pgno<(unsigned)minV ){
-        minI = j;
-        minV = apNew[j]->pgno;
+  for(i=0; i<nNew; i++){
+    aPgOrder[i] = aPgno[i] = apNew[i]->pgno;
+    aPgFlags[i] = apNew[i]->pDbPage->flags;
+    for(j=0; j<i; j++){
+      if( aPgno[j]==aPgno[i] ){
+        /* This branch is taken if the set of sibling pages somehow contains
+        ** duplicate entries. This can happen if the database is corrupt. 
+        ** It would be simpler to detect this as part of the loop below, but
+        ** we do the detection here in order to avoid populating the pager
+        ** cache with two separate objects associated with the same
+        ** page number.  */
+        assert( CORRUPT_DB );
+        rc = SQLITE_CORRUPT_BKPT;
+        goto balance_cleanup;
       }
     }
-    if( minI>i ){
-      MemPage *pT;
-      pT = apNew[i];
-      apNew[i] = apNew[minI];
-      apNew[minI] = pT;
+  }
+  for(i=0; i<nNew; i++){
+    int iBest = 0;                /* aPgno[] index of page number to use */
+    for(j=1; j<nNew; j++){
+      if( aPgOrder[j]<aPgOrder[iBest] ) iBest = j;
+    }
+    pgno = aPgOrder[iBest];
+    aPgOrder[iBest] = 0xffffffff;
+    if( iBest!=i ){
+      if( iBest>i ){
+        sqlite3PagerRekey(apNew[iBest]->pDbPage, pBt->nPage+iBest+1, 0);
+      }
+      sqlite3PagerRekey(apNew[i]->pDbPage, pgno, aPgFlags[iBest]);
+      apNew[i]->pgno = pgno;
     }
   }
-  TRACE(("new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",
-    apNew[0]->pgno, szNew[0],
+
+  TRACE(("BALANCE: new: %d(%d nc=%d) %d(%d nc=%d) %d(%d nc=%d) "
+         "%d(%d nc=%d) %d(%d nc=%d)\n",
+    apNew[0]->pgno, szNew[0], cntNew[0],
     nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,
+    nNew>=2 ? cntNew[1] - cntNew[0] - !leafData : 0,
     nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,
+    nNew>=3 ? cntNew[2] - cntNew[1] - !leafData : 0,
     nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,
-    nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0));
+    nNew>=4 ? cntNew[3] - cntNew[2] - !leafData : 0,
+    nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0,
+    nNew>=5 ? cntNew[4] - cntNew[3] - !leafData : 0
+  ));
 
   assert( sqlite3PagerIswriteable(pParent->pDbPage) );
   put4byte(pRight, apNew[nNew-1]->pgno);
 
-  /*
-  ** Evenly distribute the data in apCell[] across the new pages.
-  ** Insert divider cells into pParent as necessary.
+  /* If the sibling pages are not leaves, ensure that the right-child pointer
+  ** of the right-most new sibling page is set to the value that was 
+  ** originally in the same field of the right-most old sibling page. */
+  if( (pageFlags & PTF_LEAF)==0 && nOld!=nNew ){
+    MemPage *pOld = (nNew>nOld ? apNew : apOld)[nOld-1];
+    memcpy(&apNew[nNew-1]->aData[8], &pOld->aData[8], 4);
+  }
+
+  /* Make any required updates to pointer map entries associated with 
+  ** cells stored on sibling pages following the balance operation. Pointer
+  ** map entries associated with divider cells are set by the insertCell()
+  ** routine. The associated pointer map entries are:
+  **
+  **   a) if the cell contains a reference to an overflow chain, the
+  **      entry associated with the first page in the overflow chain, and
+  **
+  **   b) if the sibling pages are not leaves, the child page associated
+  **      with the cell.
+  **
+  ** If the sibling pages are not leaves, then the pointer map entry 
+  ** associated with the right-child of each sibling may also need to be 
+  ** updated. This happens below, after the sibling pages have been 
+  ** populated, not here.
   */
-  j = 0;
-  for(i=0; i<nNew; i++){
-    /* Assemble the new sibling page. */
+  if( ISAUTOVACUUM ){
+    MemPage *pNew = apNew[0];
+    u8 *aOld = pNew->aData;
+    int cntOldNext = pNew->nCell + pNew->nOverflow;
+    int usableSize = pBt->usableSize;
+    int iNew = 0;
+    int iOld = 0;
+
+    for(i=0; i<b.nCell; i++){
+      u8 *pCell = b.apCell[i];
+      if( i==cntOldNext ){
+        MemPage *pOld = (++iOld)<nNew ? apNew[iOld] : apOld[iOld];
+        cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;
+        aOld = pOld->aData;
+      }
+      if( i==cntNew[iNew] ){
+        pNew = apNew[++iNew];
+        if( !leafData ) continue;
+      }
+
+      /* Cell pCell is destined for new sibling page pNew. Originally, it
+      ** was either part of sibling page iOld (possibly an overflow cell), 
+      ** or else the divider cell to the left of sibling page iOld. So,
+      ** if sibling page iOld had the same page number as pNew, and if
+      ** pCell really was a part of sibling page iOld (not a divider or
+      ** overflow cell), we can skip updating the pointer map entries.  */
+      if( iOld>=nNew
+       || pNew->pgno!=aPgno[iOld]
+       || !SQLITE_WITHIN(pCell,aOld,&aOld[usableSize])
+      ){
+        if( !leafCorrection ){
+          ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
+        }
+        if( cachedCellSize(&b,i)>pNew->minLocal ){
+          ptrmapPutOvflPtr(pNew, pCell, &rc);
+        }
+        if( rc ) goto balance_cleanup;
+      }
+    }
+  }
+
+  /* Insert new divider cells into pParent. */
+  for(i=0; i<nNew-1; i++){
+    u8 *pCell;
+    u8 *pTemp;
+    int sz;
     MemPage *pNew = apNew[i];
+    j = cntNew[i];
+
     assert( j<nMaxCells );
-    zeroPage(pNew, pageFlags);
-    assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
-    assert( pNew->nCell>0 || (nNew==1 && cntNew[0]==0) );
-    assert( pNew->nOverflow==0 );
+    assert( b.apCell[j]!=0 );
+    pCell = b.apCell[j];
+    sz = b.szCell[j] + leafCorrection;
+    pTemp = &aOvflSpace[iOvflSpace];
+    if( !pNew->leaf ){
+      memcpy(&pNew->aData[8], pCell, 4);
+    }else if( leafData ){
+      /* If the tree is a leaf-data tree, and the siblings are leaves, 
+      ** then there is no divider cell in b.apCell[]. Instead, the divider 
+      ** cell consists of the integer key for the right-most cell of 
+      ** the sibling-page assembled above only.
+      */
+      CellInfo info;
+      j--;
+      pNew->xParseCell(pNew, b.apCell[j], &info);
+      pCell = pTemp;
+      sz = 4 + putVarint(&pCell[4], info.nKey);
+      pTemp = 0;
+    }else{
+      pCell -= 4;
+      /* Obscure case for non-leaf-data trees: If the cell at pCell was
+      ** previously stored on a leaf node, and its reported size was 4
+      ** bytes, then it may actually be smaller than this 
+      ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
+      ** any cell). But it is important to pass the correct size to 
+      ** insertCell(), so reparse the cell now.
+      **
+      ** This can only happen for b-trees used to evaluate "IN (SELECT ...)"
+      ** and WITHOUT ROWID tables with exactly one column which is the
+      ** primary key.
+      */
+      if( b.szCell[j]==4 ){
+        assert(leafCorrection==4);
+        sz = pParent->xCellSize(pParent, pCell);
+      }
+    }
+    iOvflSpace += sz;
+    assert( sz<=pBt->maxLocal+23 );
+    assert( iOvflSpace <= (int)pBt->pageSize );
+    insertCell(pParent, nxDiv+i, pCell, sz, pTemp, pNew->pgno, &rc);
+    if( rc!=SQLITE_OK ) goto balance_cleanup;
+    assert( sqlite3PagerIswriteable(pParent->pDbPage) );
+  }
 
-    j = cntNew[i];
+  /* Now update the actual sibling pages. The order in which they are updated
+  ** is important, as this code needs to avoid disrupting any page from which
+  ** cells may still to be read. In practice, this means:
+  **
+  **  (1) If cells are moving left (from apNew[iPg] to apNew[iPg-1])
+  **      then it is not safe to update page apNew[iPg] until after
+  **      the left-hand sibling apNew[iPg-1] has been updated.
+  **
+  **  (2) If cells are moving right (from apNew[iPg] to apNew[iPg+1])
+  **      then it is not safe to update page apNew[iPg] until after
+  **      the right-hand sibling apNew[iPg+1] has been updated.
+  **
+  ** If neither of the above apply, the page is safe to update.
+  **
+  ** The iPg value in the following loop starts at nNew-1 goes down
+  ** to 0, then back up to nNew-1 again, thus making two passes over
+  ** the pages.  On the initial downward pass, only condition (1) above
+  ** needs to be tested because (2) will always be true from the previous
+  ** step.  On the upward pass, both conditions are always true, so the
+  ** upwards pass simply processes pages that were missed on the downward
+  ** pass.
+  */
+  for(i=1-nNew; i<nNew; i++){
+    int iPg = i<0 ? -i : i;
+    assert( iPg>=0 && iPg<nNew );
+    if( abDone[iPg] ) continue;         /* Skip pages already processed */
+    if( i>=0                            /* On the upwards pass, or... */
+     || cntOld[iPg-1]>=cntNew[iPg-1]    /* Condition (1) is true */
+    ){
+      int iNew;
+      int iOld;
+      int nNewCell;
 
-    /* If the sibling page assembled above was not the right-most sibling,
-    ** insert a divider cell into the parent page.
-    */
-    assert( i<nNew-1 || j==nCell );
-    if( j<nCell ){
-      u8 *pCell;
-      u8 *pTemp;
-      int sz;
+      /* Verify condition (1):  If cells are moving left, update iPg
+      ** only after iPg-1 has already been updated. */
+      assert( iPg==0 || cntOld[iPg-1]>=cntNew[iPg-1] || abDone[iPg-1] );
 
-      assert( j<nMaxCells );
-      pCell = apCell[j];
-      sz = szCell[j] + leafCorrection;
-      pTemp = &aOvflSpace[iOvflSpace];
-      if( !pNew->leaf ){
-        memcpy(&pNew->aData[8], pCell, 4);
-      }else if( leafData ){
-        /* If the tree is a leaf-data tree, and the siblings are leaves, 
-        ** then there is no divider cell in apCell[]. Instead, the divider 
-        ** cell consists of the integer key for the right-most cell of 
-        ** the sibling-page assembled above only.
-        */
-        CellInfo info;
-        j--;
-        btreeParseCellPtr(pNew, apCell[j], &info);
-        pCell = pTemp;
-        sz = 4 + putVarint(&pCell[4], info.nKey);
-        pTemp = 0;
+      /* Verify condition (2):  If cells are moving right, update iPg
+      ** only after iPg+1 has already been updated. */
+      assert( cntNew[iPg]>=cntOld[iPg] || abDone[iPg+1] );
+
+      if( iPg==0 ){
+        iNew = iOld = 0;
+        nNewCell = cntNew[0];
       }else{
-        pCell -= 4;
-        /* Obscure case for non-leaf-data trees: If the cell at pCell was
-        ** previously stored on a leaf node, and its reported size was 4
-        ** bytes, then it may actually be smaller than this 
-        ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
-        ** any cell). But it is important to pass the correct size to 
-        ** insertCell(), so reparse the cell now.
-        **
-        ** Note that this can never happen in an SQLite data file, as all
-        ** cells are at least 4 bytes. It only happens in b-trees used
-        ** to evaluate "IN (SELECT ...)" and similar clauses.
-        */
-        if( szCell[j]==4 ){
-          assert(leafCorrection==4);
-          sz = cellSizePtr(pParent, pCell);
-        }
+        iOld = iPg<nOld ? (cntOld[iPg-1] + !leafData) : b.nCell;
+        iNew = cntNew[iPg-1] + !leafData;
+        nNewCell = cntNew[iPg] - iNew;
       }
-      iOvflSpace += sz;
-      assert( sz<=pBt->maxLocal+23 );
-      assert( iOvflSpace <= (int)pBt->pageSize );
-      insertCell(pParent, nxDiv, pCell, sz, pTemp, pNew->pgno, &rc);
-      if( rc!=SQLITE_OK ) goto balance_cleanup;
-      assert( sqlite3PagerIswriteable(pParent->pDbPage) );
 
-      j++;
-      nxDiv++;
+      rc = editPage(apNew[iPg], iOld, iNew, nNewCell, &b);
+      if( rc ) goto balance_cleanup;
+      abDone[iPg]++;
+      apNew[iPg]->nFree = usableSpace-szNew[iPg];
+      assert( apNew[iPg]->nOverflow==0 );
+      assert( apNew[iPg]->nCell==nNewCell );
     }
   }
-  assert( j==nCell );
+
+  /* All pages have been processed exactly once */
+  assert( memcmp(abDone, "\01\01\01\01\01", nNew)==0 );
+
   assert( nOld>0 );
   assert( nNew>0 );
-  if( (pageFlags & PTF_LEAF)==0 ){
-    u8 *zChild = &apCopy[nOld-1]->aData[8];
-    memcpy(&apNew[nNew-1]->aData[8], zChild, 4);
-  }
 
   if( isRoot && pParent->nCell==0 && pParent->hdrOffset<=apNew[0]->nFree ){
     /* The root page of the b-tree now contains no cells. The only sibling
@@ -54449,131 +65793,56 @@ static int balance_nonroot(
     ** sets all pointer-map entries corresponding to database image pages 
     ** for which the pointer is stored within the content being copied.
     **
-    ** The second assert below verifies that the child page is defragmented
-    ** (it must be, as it was just reconstructed using assemblePage()). This
-    ** is important if the parent page happens to be page 1 of the database
-    ** image.  */
-    assert( nNew==1 );
+    ** It is critical that the child page be defragmented before being
+    ** copied into the parent, because if the parent is page 1 then it will
+    ** by smaller than the child due to the database header, and so all the
+    ** free space needs to be up front.
+    */
+    assert( nNew==1 || CORRUPT_DB );
+    rc = defragmentPage(apNew[0]);
+    testcase( rc!=SQLITE_OK );
     assert( apNew[0]->nFree == 
-        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2) 
+        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
+      || rc!=SQLITE_OK
     );
     copyNodeContent(apNew[0], pParent, &rc);
     freePage(apNew[0], &rc);
-  }else if( ISAUTOVACUUM ){
-    /* Fix the pointer-map entries for all the cells that were shifted around. 
-    ** There are several different types of pointer-map entries that need to
-    ** be dealt with by this routine. Some of these have been set already, but
-    ** many have not. The following is a summary:
-    **
-    **   1) The entries associated with new sibling pages that were not
-    **      siblings when this function was called. These have already
-    **      been set. We don't need to worry about old siblings that were
-    **      moved to the free-list - the freePage() code has taken care
-    **      of those.
-    **
-    **   2) The pointer-map entries associated with the first overflow
-    **      page in any overflow chains used by new divider cells. These 
-    **      have also already been taken care of by the insertCell() code.
-    **
-    **   3) If the sibling pages are not leaves, then the child pages of
-    **      cells stored on the sibling pages may need to be updated.
-    **
-    **   4) If the sibling pages are not internal intkey nodes, then any
-    **      overflow pages used by these cells may need to be updated
-    **      (internal intkey nodes never contain pointers to overflow pages).
-    **
-    **   5) If the sibling pages are not leaves, then the pointer-map
-    **      entries for the right-child pages of each sibling may need
-    **      to be updated.
-    **
-    ** Cases 1 and 2 are dealt with above by other code. The next
-    ** block deals with cases 3 and 4 and the one after that, case 5. Since
-    ** setting a pointer map entry is a relatively expensive operation, this
-    ** code only sets pointer map entries for child or overflow pages that have
-    ** actually moved between pages.  */
-    MemPage *pNew = apNew[0];
-    MemPage *pOld = apCopy[0];
-    int nOverflow = pOld->nOverflow;
-    int iNextOld = pOld->nCell + nOverflow;
-    int iOverflow = (nOverflow ? pOld->aOvfl[0].idx : -1);
-    j = 0;                             /* Current 'old' sibling page */
-    k = 0;                             /* Current 'new' sibling page */
-    for(i=0; i<nCell; i++){
-      int isDivider = 0;
-      while( i==iNextOld ){
-        /* Cell i is the cell immediately following the last cell on old
-        ** sibling page j. If the siblings are not leaf pages of an
-        ** intkey b-tree, then cell i was a divider cell. */
-        assert( j+1 < ArraySize(apCopy) );
-        pOld = apCopy[++j];
-        iNextOld = i + !leafData + pOld->nCell + pOld->nOverflow;
-        if( pOld->nOverflow ){
-          nOverflow = pOld->nOverflow;
-          iOverflow = i + !leafData + pOld->aOvfl[0].idx;
-        }
-        isDivider = !leafData;  
-      }
-
-      assert(nOverflow>0 || iOverflow<i );
-      assert(nOverflow<2 || pOld->aOvfl[0].idx==pOld->aOvfl[1].idx-1);
-      assert(nOverflow<3 || pOld->aOvfl[1].idx==pOld->aOvfl[2].idx-1);
-      if( i==iOverflow ){
-        isDivider = 1;
-        if( (--nOverflow)>0 ){
-          iOverflow++;
-        }
-      }
-
-      if( i==cntNew[k] ){
-        /* Cell i is the cell immediately following the last cell on new
-        ** sibling page k. If the siblings are not leaf pages of an
-        ** intkey b-tree, then cell i is a divider cell.  */
-        pNew = apNew[++k];
-        if( !leafData ) continue;
-      }
-      assert( j<nOld );
-      assert( k<nNew );
-
-      /* If the cell was originally divider cell (and is not now) or
-      ** an overflow cell, or if the cell was located on a different sibling
-      ** page before the balancing, then the pointer map entries associated
-      ** with any child or overflow pages need to be updated.  */
-      if( isDivider || pOld->pgno!=pNew->pgno ){
-        if( !leafCorrection ){
-          ptrmapPut(pBt, get4byte(apCell[i]), PTRMAP_BTREE, pNew->pgno, &rc);
-        }
-        if( szCell[i]>pNew->minLocal ){
-          ptrmapPutOvflPtr(pNew, apCell[i], &rc);
-        }
-      }
+  }else if( ISAUTOVACUUM && !leafCorrection ){
+    /* Fix the pointer map entries associated with the right-child of each
+    ** sibling page. All other pointer map entries have already been taken
+    ** care of.  */
+    for(i=0; i<nNew; i++){
+      u32 key = get4byte(&apNew[i]->aData[8]);
+      ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
     }
+  }
 
-    if( !leafCorrection ){
-      for(i=0; i<nNew; i++){
-        u32 key = get4byte(&apNew[i]->aData[8]);
-        ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
-      }
-    }
+  assert( pParent->isInit );
+  TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
+          nOld, nNew, b.nCell));
+
+  /* Free any old pages that were not reused as new pages.
+  */
+  for(i=nNew; i<nOld; i++){
+    freePage(apOld[i], &rc);
+  }
 
 #if 0
+  if( ISAUTOVACUUM && rc==SQLITE_OK && apNew[0]->isInit ){
     /* The ptrmapCheckPages() contains assert() statements that verify that
     ** all pointer map pages are set correctly. This is helpful while 
     ** debugging. This is usually disabled because a corrupt database may
     ** cause an assert() statement to fail.  */
     ptrmapCheckPages(apNew, nNew);
     ptrmapCheckPages(&pParent, 1);
-#endif
   }
-
-  assert( pParent->isInit );
-  TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
-          nOld, nNew, nCell));
+#endif
 
   /*
   ** Cleanup before returning.
   */
 balance_cleanup:
-  sqlite3ScratchFree(apCell);
+  sqlite3ScratchFree(b.apCell);
   for(i=0; i<nOld; i++){
     releasePage(apOld[i]);
   }
@@ -54637,7 +65906,10 @@ static int balance_deeper(MemPage *pRoot, MemPage **ppChild){
   TRACE(("BALANCE: copy root %d into %d\n", pRoot->pgno, pChild->pgno));
 
   /* Copy the overflow cells from pRoot to pChild */
-  memcpy(pChild->aOvfl, pRoot->aOvfl, pRoot->nOverflow*sizeof(pRoot->aOvfl[0]));
+  memcpy(pChild->aiOvfl, pRoot->aiOvfl,
+         pRoot->nOverflow*sizeof(pRoot->aiOvfl[0]));
+  memcpy(pChild->apOvfl, pRoot->apOvfl,
+         pRoot->nOverflow*sizeof(pRoot->apOvfl[0]));
   pChild->nOverflow = pRoot->nOverflow;
 
   /* Zero the contents of pRoot. Then install pChild as the right-child. */
@@ -54664,8 +65936,8 @@ static int balance(BtCursor *pCur){
   u8 aBalanceQuickSpace[13];
   u8 *pFree = 0;
 
-  TESTONLY( int balance_quick_called = 0 );
-  TESTONLY( int balance_deeper_called = 0 );
+  VVA_ONLY( int balance_quick_called = 0 );
+  VVA_ONLY( int balance_deeper_called = 0 );
 
   do {
     int iPage = pCur->iPage;
@@ -54678,7 +65950,8 @@ static int balance(BtCursor *pCur){
         ** and copy the current contents of the root-page to it. The
         ** next iteration of the do-loop will balance the child page.
         */ 
-        assert( (balance_deeper_called++)==0 );
+        assert( balance_deeper_called==0 );
+        VVA_ONLY( balance_deeper_called++ );
         rc = balance_deeper(pPage, &pCur->apPage[1]);
         if( rc==SQLITE_OK ){
           pCur->iPage = 1;
@@ -54698,16 +65971,16 @@ static int balance(BtCursor *pCur){
       rc = sqlite3PagerWrite(pParent->pDbPage);
       if( rc==SQLITE_OK ){
 #ifndef SQLITE_OMIT_QUICKBALANCE
-        if( pPage->hasData
+        if( pPage->intKeyLeaf
          && pPage->nOverflow==1
-         && pPage->aOvfl[0].idx==pPage->nCell
+         && pPage->aiOvfl[0]==pPage->nCell
          && pParent->pgno!=1
          && pParent->nCell==iIdx
         ){
           /* Call balance_quick() to create a new sibling of pPage on which
           ** to store the overflow cell. balance_quick() inserts a new cell
           ** into pParent, which may cause pParent overflow. If this
-          ** happens, the next interation of the do-loop will balance pParent 
+          ** happens, the next iteration of the do-loop will balance pParent 
           ** use either balance_nonroot() or balance_deeper(). Until this
           ** happens, the overflow cell is stored in the aBalanceQuickSpace[]
           ** buffer. 
@@ -54717,7 +65990,8 @@ static int balance(BtCursor *pCur){
           ** function. If this were not verified, a subtle bug involving reuse
           ** of the aBalanceQuickSpace[] might sneak in.
           */
-          assert( (balance_quick_called++)==0 );
+          assert( balance_quick_called==0 ); 
+          VVA_ONLY( balance_quick_called++ );
           rc = balance_quick(pParent, pPage, aBalanceQuickSpace);
         }else
 #endif
@@ -54740,7 +66014,8 @@ static int balance(BtCursor *pCur){
           ** pSpace buffer passed to the latter call to balance_nonroot().
           */
           u8 *pSpace = sqlite3PageMalloc(pCur->pBt->pageSize);
-          rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1);
+          rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1,
+                               pCur->hints&BTREE_BULKLOAD);
           if( pFree ){
             /* If pFree is not NULL, it points to the pSpace buffer used 
             ** by a previous call to balance_nonroot(). Its contents are
@@ -54761,6 +66036,7 @@ static int balance(BtCursor *pCur){
       /* The next iteration of the do-loop balances the parent page. */
       releasePage(pPage);
       pCur->iPage--;
+      assert( pCur->iPage>=0 );
     }
   }while( rc==SQLITE_OK );
 
@@ -54772,19 +66048,25 @@ static int balance(BtCursor *pCur){
 
 
 /*
-** Insert a new record into the BTree.  The key is given by (pKey,nKey)
-** and the data is given by (pData,nData).  The cursor is used only to
-** define what table the record should be inserted into.  The cursor
-** is left pointing at a random location.
+** Insert a new record into the BTree.  The content of the new record
+** is described by the pX object.  The pCur cursor is used only to
+** define what table the record should be inserted into, and is left
+** pointing at a random location.
 **
-** For an INTKEY table, only the nKey value of the key is used.  pKey is
-** ignored.  For a ZERODATA table, the pData and nData are both ignored.
+** For a table btree (used for rowid tables), only the pX.nKey value of
+** the key is used. The pX.pKey value must be NULL.  The pX.nKey is the
+** rowid or INTEGER PRIMARY KEY of the row.  The pX.nData,pData,nZero fields
+** hold the content of the row.
+**
+** For an index btree (used for indexes and WITHOUT ROWID tables), the
+** key is an arbitrary byte sequence stored in pX.pKey,nKey.  The 
+** pX.pData,nData,nZero fields must be zero.
 **
 ** If the seekResult parameter is non-zero, then a successful call to
 ** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
 ** been performed. seekResult is the search result returned (a negative
 ** number if pCur points at an entry that is smaller than (pKey, nKey), or
-** a positive value if pCur points at an etry that is larger than 
+** a positive value if pCur points at an entry that is larger than 
 ** (pKey, nKey)). 
 **
 ** If the seekResult parameter is non-zero, then the caller guarantees that
@@ -54795,9 +66077,7 @@ static int balance(BtCursor *pCur){
 */
 SQLITE_PRIVATE int sqlite3BtreeInsert(
   BtCursor *pCur,                /* Insert data into the table of this cursor */
-  const void *pKey, i64 nKey,    /* The key of the new record */
-  const void *pData, int nData,  /* The data of the new record */
-  int nZero,                     /* Number of extra 0 bytes to append to data */
+  const BtreePayload *pX,        /* Content of the row to be inserted */
   int appendBias,                /* True if this is likely an append */
   int seekResult                 /* Result of prior MovetoUnpacked() call */
 ){
@@ -54816,8 +66096,10 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
     return pCur->skipNext;
   }
 
-  assert( cursorHoldsMutex(pCur) );
-  assert( pCur->wrFlag && pBt->inTransaction==TRANS_WRITE && !pBt->readOnly );
+  assert( cursorOwnsBtShared(pCur) );
+  assert( (pCur->curFlags & BTCF_WriteFlag)!=0
+              && pBt->inTransaction==TRANS_WRITE
+              && (pBt->btsFlags & BTS_READ_ONLY)==0 );
   assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
 
   /* Assert that the caller has been consistent. If this cursor was opened
@@ -54825,14 +66107,7 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** keys with no associated data. If the cursor was opened expecting an
   ** intkey table, the caller should be inserting integer keys with a
   ** blob of associated data.  */
-  assert( (pKey==0)==(pCur->pKeyInfo==0) );
-
-  /* If this is an insert into a table b-tree, invalidate any incrblob 
-  ** cursors open on the row being replaced (assuming this is a replace
-  ** operation - if it is not, the following is a no-op).  */
-  if( pCur->pKeyInfo==0 ){
-    invalidateIncrblobCursors(p, nKey, 0);
-  }
+  assert( (pX->pKey==0)==(pCur->pKeyInfo==0) );
 
   /* Save the positions of any other cursors open on this table.
   **
@@ -54845,28 +66120,46 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** doing any work. To avoid thwarting these optimizations, it is important
   ** not to clear the cursor here.
   */
-  rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
-  if( rc ) return rc;
-  if( !loc ){
-    rc = btreeMoveto(pCur, pKey, nKey, appendBias, &loc);
+  if( pCur->curFlags & BTCF_Multiple ){
+    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+    if( rc ) return rc;
+  }
+
+  if( pCur->pKeyInfo==0 ){
+    assert( pX->pKey==0 );
+    /* If this is an insert into a table b-tree, invalidate any incrblob 
+    ** cursors open on the row being replaced */
+    invalidateIncrblobCursors(p, pX->nKey, 0);
+
+    /* If the cursor is currently on the last row and we are appending a
+    ** new row onto the end, set the "loc" to avoid an unnecessary
+    ** btreeMoveto() call */
+    if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey>0
+      && pCur->info.nKey==pX->nKey-1 ){
+       loc = -1;
+    }else if( loc==0 ){
+      rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, appendBias, &loc);
+      if( rc ) return rc;
+    }
+  }else if( loc==0 ){
+    rc = btreeMoveto(pCur, pX->pKey, pX->nKey, appendBias, &loc);
     if( rc ) return rc;
   }
   assert( pCur->eState==CURSOR_VALID || (pCur->eState==CURSOR_INVALID && loc) );
 
   pPage = pCur->apPage[pCur->iPage];
-  assert( pPage->intKey || nKey>=0 );
+  assert( pPage->intKey || pX->nKey>=0 );
   assert( pPage->leaf || !pPage->intKey );
 
   TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
-          pCur->pgnoRoot, nKey, nData, pPage->pgno,
+          pCur->pgnoRoot, pX->nKey, pX->nData, pPage->pgno,
           loc==0 ? "overwrite" : "new entry"));
   assert( pPage->isInit );
-  allocateTempSpace(pBt);
   newCell = pBt->pTmpSpace;
-  if( newCell==0 ) return SQLITE_NOMEM;
-  rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, &szNew);
+  assert( newCell!=0 );
+  rc = fillInCell(pPage, newCell, pX, &szNew);
   if( rc ) goto end_insert;
-  assert( szNew==cellSizePtr(pPage, newCell) );
+  assert( szNew==pPage->xCellSize(pPage, newCell) );
   assert( szNew <= MX_CELL_SIZE(pBt) );
   idx = pCur->aiIdx[pCur->iPage];
   if( loc==0 ){
@@ -54880,8 +66173,7 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
     if( !pPage->leaf ){
       memcpy(newCell, oldCell, 4);
     }
-    szOld = cellSizePtr(pPage, oldCell);
-    rc = clearCell(pPage, oldCell);
+    rc = clearCell(pPage, oldCell, &szOld);
     dropCell(pPage, idx, szOld, &rc);
     if( rc ) goto end_insert;
   }else if( loc<0 && pPage->nCell>0 ){
@@ -54891,11 +66183,12 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
     assert( pPage->leaf );
   }
   insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);
+  assert( pPage->nOverflow==0 || rc==SQLITE_OK );
   assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );
 
-  /* If no error has occured and pPage has an overflow cell, call balance() 
+  /* If no error has occurred and pPage has an overflow cell, call balance() 
   ** to redistribute the cells within the tree. Since balance() may move
-  ** the cursor, zero the BtCursor.info.nSize and BtCursor.validNKey
+  ** the cursor, zero the BtCursor.info.nSize and BTCF_ValidNKey
   ** variables.
   **
   ** Previous versions of SQLite called moveToRoot() to move the cursor
@@ -54914,8 +66207,9 @@ SQLITE_PRIVATE int sqlite3BtreeInsert(
   ** row without seeking the cursor. This can be a big performance boost.
   */
   pCur->info.nSize = 0;
-  pCur->validNKey = 0;
-  if( rc==SQLITE_OK && pPage->nOverflow ){
+  if( pPage->nOverflow ){
+    assert( rc==SQLITE_OK );
+    pCur->curFlags &= ~(BTCF_ValidNKey);
     rc = balance(pCur);
 
     /* Must make sure nOverflow is reset to zero even if the balance()
@@ -54932,10 +66226,23 @@ end_insert:
 }
 
 /*
-** Delete the entry that the cursor is pointing to.  The cursor
-** is left pointing at a arbitrary location.
+** Delete the entry that the cursor is pointing to. 
+**
+** If the BTREE_SAVEPOSITION bit of the flags parameter is zero, then
+** the cursor is left pointing at an arbitrary location after the delete.
+** But if that bit is set, then the cursor is left in a state such that
+** the next call to BtreeNext() or BtreePrev() moves it to the same row
+** as it would have been on if the call to BtreeDelete() had been omitted.
+**
+** The BTREE_AUXDELETE bit of flags indicates that is one of several deletes
+** associated with a single table entry and its indexes.  Only one of those
+** deletes is considered the "primary" delete.  The primary delete occurs
+** on a cursor that is not a BTREE_FORDELETE cursor.  All but one delete
+** operation on non-FORDELETE cursors is tagged with the AUXDELETE flag.
+** The BTREE_AUXDELETE bit is a hint that is not used by this implementation,
+** but which might be used by alternative storage engines.
 */
-SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
+SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
   Btree *p = pCur->pBtree;
   BtShared *pBt = p->pBt;              
   int rc;                              /* Return code */
@@ -54943,31 +66250,47 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   unsigned char *pCell;                /* Pointer to cell to delete */
   int iCellIdx;                        /* Index of cell to delete */
   int iCellDepth;                      /* Depth of node containing pCell */ 
+  u16 szCell;                          /* Size of the cell being deleted */
+  int bSkipnext = 0;                   /* Leaf cursor in SKIPNEXT state */
+  u8 bPreserve = flags & BTREE_SAVEPOSITION;  /* Keep cursor valid */
 
-  assert( cursorHoldsMutex(pCur) );
+  assert( cursorOwnsBtShared(pCur) );
   assert( pBt->inTransaction==TRANS_WRITE );
-  assert( !pBt->readOnly );
-  assert( pCur->wrFlag );
+  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
+  assert( pCur->curFlags & BTCF_WriteFlag );
   assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
   assert( !hasReadConflicts(p, pCur->pgnoRoot) );
-
-  if( NEVER(pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell) 
-   || NEVER(pCur->eState!=CURSOR_VALID)
-  ){
-    return SQLITE_ERROR;  /* Something has gone awry. */
-  }
-
-  /* If this is a delete operation to remove a row from a table b-tree,
-  ** invalidate any incrblob cursors open on the row being deleted.  */
-  if( pCur->pKeyInfo==0 ){
-    invalidateIncrblobCursors(p, pCur->info.nKey, 0);
-  }
+  assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
+  assert( pCur->eState==CURSOR_VALID );
+  assert( (flags & ~(BTREE_SAVEPOSITION | BTREE_AUXDELETE))==0 );
 
   iCellDepth = pCur->iPage;
   iCellIdx = pCur->aiIdx[iCellDepth];
   pPage = pCur->apPage[iCellDepth];
   pCell = findCell(pPage, iCellIdx);
 
+  /* If the bPreserve flag is set to true, then the cursor position must
+  ** be preserved following this delete operation. If the current delete
+  ** will cause a b-tree rebalance, then this is done by saving the cursor
+  ** key and leaving the cursor in CURSOR_REQUIRESEEK state before 
+  ** returning. 
+  **
+  ** Or, if the current delete will not cause a rebalance, then the cursor
+  ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately
+  ** before or after the deleted entry. In this case set bSkipnext to true.  */
+  if( bPreserve ){
+    if( !pPage->leaf 
+     || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
+    ){
+      /* A b-tree rebalance will be required after deleting this entry.
+      ** Save the cursor key.  */
+      rc = saveCursorKey(pCur);
+      if( rc ) return rc;
+    }else{
+      bSkipnext = 1;
+    }
+  }
+
   /* If the page containing the entry to delete is not a leaf page, move
   ** the cursor to the largest entry in the tree that is smaller than
   ** the entry being deleted. This cell will replace the cell being deleted
@@ -54976,22 +66299,31 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   ** sub-tree headed by the child page of the cell being deleted. This makes
   ** balancing the tree following the delete operation easier.  */
   if( !pPage->leaf ){
-    int notUsed;
+    int notUsed = 0;
     rc = sqlite3BtreePrevious(pCur, &notUsed);
     if( rc ) return rc;
   }
 
   /* Save the positions of any other cursors open on this table before
-  ** making any modifications. Make the page containing the entry to be 
-  ** deleted writable. Then free any overflow pages associated with the 
-  ** entry and finally remove the cell itself from within the page.  
-  */
-  rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
-  if( rc ) return rc;
+  ** making any modifications.  */
+  if( pCur->curFlags & BTCF_Multiple ){
+    rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+    if( rc ) return rc;
+  }
+
+  /* If this is a delete operation to remove a row from a table b-tree,
+  ** invalidate any incrblob cursors open on the row being deleted.  */
+  if( pCur->pKeyInfo==0 ){
+    invalidateIncrblobCursors(p, pCur->info.nKey, 0);
+  }
+
+  /* Make the page containing the entry to be deleted writable. Then free any
+  ** overflow pages associated with the entry and finally remove the cell
+  ** itself from within the page.  */
   rc = sqlite3PagerWrite(pPage->pDbPage);
   if( rc ) return rc;
-  rc = clearCell(pPage, pCell);
-  dropCell(pPage, iCellIdx, cellSizePtr(pPage, pCell), &rc);
+  rc = clearCell(pPage, pCell, &szCell);
+  dropCell(pPage, iCellIdx, szCell, &rc);
   if( rc ) return rc;
 
   /* If the cell deleted was not located on a leaf page, then the cursor
@@ -55006,14 +66338,15 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
     unsigned char *pTmp;
 
     pCell = findCell(pLeaf, pLeaf->nCell-1);
-    nCell = cellSizePtr(pLeaf, pCell);
+    if( pCell<&pLeaf->aData[4] ) return SQLITE_CORRUPT_BKPT;
+    nCell = pLeaf->xCellSize(pLeaf, pCell);
     assert( MX_CELL_SIZE(pBt) >= nCell );
-
-    allocateTempSpace(pBt);
     pTmp = pBt->pTmpSpace;
-
+    assert( pTmp!=0 );
     rc = sqlite3PagerWrite(pLeaf->pDbPage);
-    insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
+    if( rc==SQLITE_OK ){
+      insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);
+    }
     dropCell(pLeaf, pLeaf->nCell-1, nCell, &rc);
     if( rc ) return rc;
   }
@@ -55042,7 +66375,23 @@ SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur){
   }
 
   if( rc==SQLITE_OK ){
-    moveToRoot(pCur);
+    if( bSkipnext ){
+      assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );
+      assert( pPage==pCur->apPage[pCur->iPage] || CORRUPT_DB );
+      assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );
+      pCur->eState = CURSOR_SKIPNEXT;
+      if( iCellIdx>=pPage->nCell ){
+        pCur->skipNext = -1;
+        pCur->aiIdx[iCellDepth] = pPage->nCell-1;
+      }else{
+        pCur->skipNext = 1;
+      }
+    }else{
+      rc = moveToRoot(pCur);
+      if( bPreserve ){
+        pCur->eState = CURSOR_REQUIRESEEK;
+      }
+    }
   }
   return rc;
 }
@@ -55067,7 +66416,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
 
   assert( sqlite3BtreeHoldsMutex(p) );
   assert( pBt->inTransaction==TRANS_WRITE );
-  assert( !pBt->readOnly );
+  assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );
 
 #ifdef SQLITE_OMIT_AUTOVACUUM
   rc = allocateBtreePage(pBt, &pRoot, &pgnoRoot, 1, 0);
@@ -55100,13 +66449,14 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
         pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
       pgnoRoot++;
     }
-    assert( pgnoRoot>=3 );
+    assert( pgnoRoot>=3 || CORRUPT_DB );
+    testcase( pgnoRoot<3 );
 
     /* Allocate a page. The page that currently resides at pgnoRoot will
     ** be moved to the allocated page (unless the allocated page happens
     ** to reside at pgnoRoot).
     */
-    rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, 1);
+    rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, BTALLOC_EXACT);
     if( rc!=SQLITE_OK ){
       return rc;
     }
@@ -55121,7 +66471,14 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
       u8 eType = 0;
       Pgno iPtrPage = 0;
 
+      /* Save the positions of any open cursors. This is required in
+      ** case they are holding a reference to an xFetch reference
+      ** corresponding to page pgnoRoot.  */
+      rc = saveAllCursors(pBt, 0, 0);
       releasePage(pPageMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
 
       /* Move the page currently at pgnoRoot to pgnoMove. */
       rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
@@ -55215,37 +66572,46 @@ static int clearDatabasePage(
   int rc;
   unsigned char *pCell;
   int i;
+  int hdr;
+  u16 szCell;
 
   assert( sqlite3_mutex_held(pBt->mutex) );
   if( pgno>btreePagecount(pBt) ){
     return SQLITE_CORRUPT_BKPT;
   }
-
-  rc = getAndInitPage(pBt, pgno, &pPage);
+  rc = getAndInitPage(pBt, pgno, &pPage, 0, 0);
   if( rc ) return rc;
+  if( pPage->bBusy ){
+    rc = SQLITE_CORRUPT_BKPT;
+    goto cleardatabasepage_out;
+  }
+  pPage->bBusy = 1;
+  hdr = pPage->hdrOffset;
   for(i=0; i<pPage->nCell; i++){
     pCell = findCell(pPage, i);
     if( !pPage->leaf ){
       rc = clearDatabasePage(pBt, get4byte(pCell), 1, pnChange);
       if( rc ) goto cleardatabasepage_out;
     }
-    rc = clearCell(pPage, pCell);
+    rc = clearCell(pPage, pCell, &szCell);
     if( rc ) goto cleardatabasepage_out;
   }
   if( !pPage->leaf ){
-    rc = clearDatabasePage(pBt, get4byte(&pPage->aData[8]), 1, pnChange);
+    rc = clearDatabasePage(pBt, get4byte(&pPage->aData[hdr+8]), 1, pnChange);
     if( rc ) goto cleardatabasepage_out;
   }else if( pnChange ){
-    assert( pPage->intKey );
+    assert( pPage->intKey || CORRUPT_DB );
+    testcase( !pPage->intKey );
     *pnChange += pPage->nCell;
   }
   if( freePageFlag ){
     freePage(pPage, &rc);
   }else if( (rc = sqlite3PagerWrite(pPage->pDbPage))==0 ){
-    zeroPage(pPage, pPage->aData[0] | PTF_LEAF);
+    zeroPage(pPage, pPage->aData[hdr] | PTF_LEAF);
   }
 
 cleardatabasepage_out:
+  pPage->bBusy = 0;
   releasePage(pPage);
   return rc;
 }
@@ -55269,13 +66635,13 @@ SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree *p, int iTable, int *pnChange){
   sqlite3BtreeEnter(p);
   assert( p->inTrans==TRANS_WRITE );
 
-  /* Invalidate all incrblob cursors open on table iTable (assuming iTable
-  ** is the root of a table b-tree - if it is not, the following call is
-  ** a no-op).  */
-  invalidateIncrblobCursors(p, 0, 1);
-
   rc = saveAllCursors(pBt, (Pgno)iTable, 0);
+
   if( SQLITE_OK==rc ){
+    /* Invalidate all incrblob cursors open on table iTable (assuming iTable
+    ** is the root of a table b-tree - if it is not, the following call is
+    ** a no-op).  */
+    invalidateIncrblobCursors(p, 0, 1);
     rc = clearDatabasePage(pBt, (Pgno)iTable, 0, pnChange);
   }
   sqlite3BtreeLeave(p);
@@ -55283,6 +66649,15 @@ SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree *p, int iTable, int *pnChange){
 }
 
 /*
+** Delete all information from the single table that pCur is open on.
+**
+** This routine only work for pCur on an ephemeral table.
+*/
+SQLITE_PRIVATE int sqlite3BtreeClearTableOfCursor(BtCursor *pCur){
+  return sqlite3BtreeClearTable(pCur->pBtree, pCur->pgnoRoot, 0);
+}
+
+/*
 ** Erase all information in a table and add the root of the table to
 ** the freelist.  Except, the root of the principle table (the one on
 ** page 1) is never added to the freelist.
@@ -55323,6 +66698,14 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
     return SQLITE_LOCKED_SHAREDCACHE;
   }
 
+  /*
+  ** It is illegal to drop the sqlite_master table on page 1.  But again,
+  ** this error is caught long before reaching this point.
+  */
+  if( NEVER(iTable<2) ){
+    return SQLITE_CORRUPT_BKPT;
+  }
+
   rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
   if( rc ) return rc;
   rc = sqlite3BtreeClearTable(p, iTable, 0);
@@ -55333,76 +66716,67 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
 
   *piMoved = 0;
 
-  if( iTable>1 ){
 #ifdef SQLITE_OMIT_AUTOVACUUM
-    freePage(pPage, &rc);
-    releasePage(pPage);
+  freePage(pPage, &rc);
+  releasePage(pPage);
 #else
-    if( pBt->autoVacuum ){
-      Pgno maxRootPgno;
-      sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);
-
-      if( iTable==maxRootPgno ){
-        /* If the table being dropped is the table with the largest root-page
-        ** number in the database, put the root page on the free list. 
-        */
-        freePage(pPage, &rc);
-        releasePage(pPage);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-      }else{
-        /* The table being dropped does not have the largest root-page
-        ** number in the database. So move the page that does into the 
-        ** gap left by the deleted root-page.
-        */
-        MemPage *pMove;
-        releasePage(pPage);
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
-        releasePage(pMove);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        pMove = 0;
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
-        freePage(pMove, &rc);
-        releasePage(pMove);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        *piMoved = maxRootPgno;
-      }
+  if( pBt->autoVacuum ){
+    Pgno maxRootPgno;
+    sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);
 
-      /* Set the new 'max-root-page' value in the database header. This
-      ** is the old value less one, less one more if that happens to
-      ** be a root-page number, less one again if that is the
-      ** PENDING_BYTE_PAGE.
+    if( iTable==maxRootPgno ){
+      /* If the table being dropped is the table with the largest root-page
+      ** number in the database, put the root page on the free list. 
       */
-      maxRootPgno--;
-      while( maxRootPgno==PENDING_BYTE_PAGE(pBt)
-             || PTRMAP_ISPAGE(pBt, maxRootPgno) ){
-        maxRootPgno--;
+      freePage(pPage, &rc);
+      releasePage(pPage);
+      if( rc!=SQLITE_OK ){
+        return rc;
       }
-      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
-
-      rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
     }else{
-      freePage(pPage, &rc);
+      /* The table being dropped does not have the largest root-page
+      ** number in the database. So move the page that does into the 
+      ** gap left by the deleted root-page.
+      */
+      MemPage *pMove;
       releasePage(pPage);
+      rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
+      releasePage(pMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      pMove = 0;
+      rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+      freePage(pMove, &rc);
+      releasePage(pMove);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      *piMoved = maxRootPgno;
     }
-#endif
-  }else{
-    /* If sqlite3BtreeDropTable was called on page 1.
-    ** This really never should happen except in a corrupt
-    ** database. 
+
+    /* Set the new 'max-root-page' value in the database header. This
+    ** is the old value less one, less one more if that happens to
+    ** be a root-page number, less one again if that is the
+    ** PENDING_BYTE_PAGE.
     */
-    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
+    maxRootPgno--;
+    while( maxRootPgno==PENDING_BYTE_PAGE(pBt)
+           || PTRMAP_ISPAGE(pBt, maxRootPgno) ){
+      maxRootPgno--;
+    }
+    assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
+
+    rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
+  }else{
+    freePage(pPage, &rc);
     releasePage(pPage);
   }
+#endif
   return rc;  
 }
 SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
@@ -55426,6 +66800,13 @@ SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
 ** The schema layer numbers meta values differently.  At the schema
 ** layer (and the SetCookie and ReadCookie opcodes) the number of
 ** free pages is not visible.  So Cookie[0] is the same as Meta[1].
+**
+** This routine treats Meta[BTREE_DATA_VERSION] as a special case.  Instead
+** of reading the value out of the header, it instead loads the "DataVersion"
+** from the pager.  The BTREE_DATA_VERSION value is not actually stored in the
+** database file.  It is a number computed by the pager.  But its access
+** pattern is the same as header meta values, and so it is convenient to
+** read it from this routine.
 */
 SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
   BtShared *pBt = p->pBt;
@@ -55436,12 +66817,18 @@ SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
   assert( pBt->pPage1 );
   assert( idx>=0 && idx<=15 );
 
-  *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);
+  if( idx==BTREE_DATA_VERSION ){
+    *pMeta = sqlite3PagerDataVersion(pBt->pPager) + p->iDataVersion;
+  }else{
+    *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);
+  }
 
   /* If auto-vacuum is disabled in this build and this is an auto-vacuum
   ** database, mark the database as read-only.  */
 #ifdef SQLITE_OMIT_AUTOVACUUM
-  if( idx==BTREE_LARGEST_ROOT_PAGE && *pMeta>0 ) pBt->readOnly = 1;
+  if( idx==BTREE_LARGEST_ROOT_PAGE && *pMeta>0 ){
+    pBt->btsFlags |= BTS_READ_ONLY;
+  }
 #endif
 
   sqlite3BtreeLeave(p);
@@ -55525,7 +66912,7 @@ SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
         if( pCur->iPage==0 ){
           /* All pages of the b-tree have been visited. Return successfully. */
           *pnEntry = nEntry;
-          return SQLITE_OK;
+          return moveToRoot(pCur);
         }
         moveToParent(pCur);
       }while ( pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell );
@@ -55564,7 +66951,6 @@ SQLITE_PRIVATE Pager *sqlite3BtreePager(Btree *p){
 */
 static void checkAppendMsg(
   IntegrityCk *pCheck,
-  char *zMsg1,
   const char *zFormat,
   ...
 ){
@@ -55576,37 +66962,57 @@ static void checkAppendMsg(
   if( pCheck->errMsg.nChar ){
     sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
   }
-  if( zMsg1 ){
-    sqlite3StrAccumAppend(&pCheck->errMsg, zMsg1, -1);
+  if( pCheck->zPfx ){
+    sqlite3XPrintf(&pCheck->errMsg, pCheck->zPfx, pCheck->v1, pCheck->v2);
   }
-  sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
+  sqlite3VXPrintf(&pCheck->errMsg, zFormat, ap);
   va_end(ap);
-  if( pCheck->errMsg.mallocFailed ){
+  if( pCheck->errMsg.accError==STRACCUM_NOMEM ){
     pCheck->mallocFailed = 1;
   }
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
+
+/*
+** Return non-zero if the bit in the IntegrityCk.aPgRef[] array that
+** corresponds to page iPg is already set.
+*/
+static int getPageReferenced(IntegrityCk *pCheck, Pgno iPg){
+  assert( iPg<=pCheck->nPage && sizeof(pCheck->aPgRef[0])==1 );
+  return (pCheck->aPgRef[iPg/8] & (1 << (iPg & 0x07)));
+}
+
+/*
+** Set the bit in the IntegrityCk.aPgRef[] array that corresponds to page iPg.
+*/
+static void setPageReferenced(IntegrityCk *pCheck, Pgno iPg){
+  assert( iPg<=pCheck->nPage && sizeof(pCheck->aPgRef[0])==1 );
+  pCheck->aPgRef[iPg/8] |= (1 << (iPg & 0x07));
+}
+
+
 /*
 ** Add 1 to the reference count for page iPage.  If this is the second
 ** reference to the page, add an error message to pCheck->zErrMsg.
-** Return 1 if there are 2 ore more references to the page and 0 if
+** Return 1 if there are 2 or more references to the page and 0 if
 ** if this is the first reference to the page.
 **
 ** Also check that the page number is in bounds.
 */
-static int checkRef(IntegrityCk *pCheck, Pgno iPage, char *zContext){
+static int checkRef(IntegrityCk *pCheck, Pgno iPage){
   if( iPage==0 ) return 1;
   if( iPage>pCheck->nPage ){
-    checkAppendMsg(pCheck, zContext, "invalid page number %d", iPage);
+    checkAppendMsg(pCheck, "invalid page number %d", iPage);
     return 1;
   }
-  if( pCheck->anRef[iPage]==1 ){
-    checkAppendMsg(pCheck, zContext, "2nd reference to page %d", iPage);
+  if( getPageReferenced(pCheck, iPage) ){
+    checkAppendMsg(pCheck, "2nd reference to page %d", iPage);
     return 1;
   }
-  return  (pCheck->anRef[iPage]++)>1;
+  setPageReferenced(pCheck, iPage);
+  return 0;
 }
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -55619,8 +67025,7 @@ static void checkPtrmap(
   IntegrityCk *pCheck,   /* Integrity check context */
   Pgno iChild,           /* Child page number */
   u8 eType,              /* Expected pointer map type */
-  Pgno iParent,          /* Expected pointer map parent page number */
-  char *zContext         /* Context description (used for error msg) */
+  Pgno iParent           /* Expected pointer map parent page number */
 ){
   int rc;
   u8 ePtrmapType;
@@ -55629,12 +67034,12 @@ static void checkPtrmap(
   rc = ptrmapGet(pCheck->pBt, iChild, &ePtrmapType, &iPtrmapParent);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ) pCheck->mallocFailed = 1;
-    checkAppendMsg(pCheck, zContext, "Failed to read ptrmap key=%d", iChild);
+    checkAppendMsg(pCheck, "Failed to read ptrmap key=%d", iChild);
     return;
   }
 
   if( ePtrmapType!=eType || iPtrmapParent!=iParent ){
-    checkAppendMsg(pCheck, zContext, 
+    checkAppendMsg(pCheck,
       "Bad ptr map entry key=%d expected=(%d,%d) got=(%d,%d)", 
       iChild, eType, iParent, ePtrmapType, iPtrmapParent);
   }
@@ -55649,8 +67054,7 @@ static void checkList(
   IntegrityCk *pCheck,  /* Integrity checking context */
   int isFreeList,       /* True for a freelist.  False for overflow page list */
   int iPage,            /* Page number for first page in the list */
-  int N,                /* Expected number of pages in the list */
-  char *zContext        /* Context for error messages */
+  int N                 /* Expected number of pages in the list */
 ){
   int i;
   int expected = N;
@@ -55659,14 +67063,14 @@ static void checkList(
     DbPage *pOvflPage;
     unsigned char *pOvflData;
     if( iPage<1 ){
-      checkAppendMsg(pCheck, zContext,
+      checkAppendMsg(pCheck,
          "%d of %d pages missing from overflow list starting at %d",
           N+1, expected, iFirst);
       break;
     }
-    if( checkRef(pCheck, iPage, zContext) ) break;
-    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage) ){
-      checkAppendMsg(pCheck, zContext, "failed to get page %d", iPage);
+    if( checkRef(pCheck, iPage) ) break;
+    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
+      checkAppendMsg(pCheck, "failed to get page %d", iPage);
       break;
     }
     pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);
@@ -55674,11 +67078,11 @@ static void checkList(
       int n = get4byte(&pOvflData[4]);
 #ifndef SQLITE_OMIT_AUTOVACUUM
       if( pCheck->pBt->autoVacuum ){
-        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0, zContext);
+        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0);
       }
 #endif
       if( n>(int)pCheck->pBt->usableSize/4-2 ){
-        checkAppendMsg(pCheck, zContext,
+        checkAppendMsg(pCheck,
            "freelist leaf count too big on page %d", iPage);
         N--;
       }else{
@@ -55686,10 +67090,10 @@ static void checkList(
           Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
 #ifndef SQLITE_OMIT_AUTOVACUUM
           if( pCheck->pBt->autoVacuum ){
-            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0, zContext);
+            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0);
           }
 #endif
-          checkRef(pCheck, iFreePage, zContext);
+          checkRef(pCheck, iFreePage);
         }
         N -= n;
       }
@@ -55702,16 +67106,71 @@ static void checkList(
       */
       if( pCheck->pBt->autoVacuum && N>0 ){
         i = get4byte(pOvflData);
-        checkPtrmap(pCheck, i, PTRMAP_OVERFLOW2, iPage, zContext);
+        checkPtrmap(pCheck, i, PTRMAP_OVERFLOW2, iPage);
       }
     }
 #endif
     iPage = get4byte(pOvflData);
     sqlite3PagerUnref(pOvflPage);
+
+    if( isFreeList && N<(iPage!=0) ){
+      checkAppendMsg(pCheck, "free-page count in header is too small");
+    }
   }
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
+/*
+** An implementation of a min-heap.
+**
+** aHeap[0] is the number of elements on the heap.  aHeap[1] is the
+** root element.  The daughter nodes of aHeap[N] are aHeap[N*2]
+** and aHeap[N*2+1].
+**
+** The heap property is this:  Every node is less than or equal to both
+** of its daughter nodes.  A consequence of the heap property is that the
+** root node aHeap[1] is always the minimum value currently in the heap.
+**
+** The btreeHeapInsert() routine inserts an unsigned 32-bit number onto
+** the heap, preserving the heap property.  The btreeHeapPull() routine
+** removes the root element from the heap (the minimum value in the heap)
+** and then moves other nodes around as necessary to preserve the heap
+** property.
+**
+** This heap is used for cell overlap and coverage testing.  Each u32
+** entry represents the span of a cell or freeblock on a btree page.  
+** The upper 16 bits are the index of the first byte of a range and the
+** lower 16 bits are the index of the last byte of that range.
+*/
+static void btreeHeapInsert(u32 *aHeap, u32 x){
+  u32 j, i = ++aHeap[0];
+  aHeap[i] = x;
+  while( (j = i/2)>0 && aHeap[j]>aHeap[i] ){
+    x = aHeap[j];
+    aHeap[j] = aHeap[i];
+    aHeap[i] = x;
+    i = j;
+  }
+}
+static int btreeHeapPull(u32 *aHeap, u32 *pOut){
+  u32 j, i, x;
+  if( (x = aHeap[0])==0 ) return 0;
+  *pOut = aHeap[1];
+  aHeap[1] = aHeap[x];
+  aHeap[x] = 0xffffffff;
+  aHeap[0]--;
+  i = 1;
+  while( (j = i*2)<=aHeap[0] ){
+    if( aHeap[j]>aHeap[j+1] ) j++;
+    if( aHeap[i]<aHeap[j] ) break;
+    x = aHeap[i];
+    aHeap[i] = aHeap[j];
+    aHeap[j] = x;
+    i = j;
+  }
+  return 1;  
+}
+
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
 /*
 ** Do various sanity checks on a single page of a tree.  Return
@@ -55722,221 +67181,257 @@ static void checkList(
 **
 **      1.  Make sure that cells and freeblocks do not overlap
 **          but combine to completely cover the page.
-**  NO  2.  Make sure cell keys are in order.
-**  NO  3.  Make sure no key is less than or equal to zLowerBound.
-**  NO  4.  Make sure no key is greater than or equal to zUpperBound.
-**      5.  Check the integrity of overflow pages.
-**      6.  Recursively call checkTreePage on all children.
-**      7.  Verify that the depth of all children is the same.
-**      8.  Make sure this page is at least 33% full or else it is
-**          the root of the tree.
+**      2.  Make sure integer cell keys are in order.
+**      3.  Check the integrity of overflow pages.
+**      4.  Recursively call checkTreePage on all children.
+**      5.  Verify that the depth of all children is the same.
 */
 static int checkTreePage(
   IntegrityCk *pCheck,  /* Context for the sanity check */
   int iPage,            /* Page number of the page to check */
-  char *zParentContext, /* Parent context */
-  i64 *pnParentMinKey, 
-  i64 *pnParentMaxKey
+  i64 *piMinKey,        /* Write minimum integer primary key here */
+  i64 maxKey            /* Error if integer primary key greater than this */
 ){
-  MemPage *pPage;
-  int i, rc, depth, d2, pgno, cnt;
-  int hdr, cellStart;
-  int nCell;
-  u8 *data;
-  BtShared *pBt;
-  int usableSize;
-  char zContext[100];
-  char *hit = 0;
-  i64 nMinKey = 0;
-  i64 nMaxKey = 0;
-
-  sqlite3_snprintf(sizeof(zContext), zContext, "Page %d: ", iPage);
+  MemPage *pPage = 0;      /* The page being analyzed */
+  int i;                   /* Loop counter */
+  int rc;                  /* Result code from subroutine call */
+  int depth = -1, d2;      /* Depth of a subtree */
+  int pgno;                /* Page number */
+  int nFrag;               /* Number of fragmented bytes on the page */
+  int hdr;                 /* Offset to the page header */
+  int cellStart;           /* Offset to the start of the cell pointer array */
+  int nCell;               /* Number of cells */
+  int doCoverageCheck = 1; /* True if cell coverage checking should be done */
+  int keyCanBeEqual = 1;   /* True if IPK can be equal to maxKey
+                           ** False if IPK must be strictly less than maxKey */
+  u8 *data;                /* Page content */
+  u8 *pCell;               /* Cell content */
+  u8 *pCellIdx;            /* Next element of the cell pointer array */
+  BtShared *pBt;           /* The BtShared object that owns pPage */
+  u32 pc;                  /* Address of a cell */
+  u32 usableSize;          /* Usable size of the page */
+  u32 contentOffset;       /* Offset to the start of the cell content area */
+  u32 *heap = 0;           /* Min-heap used for checking cell coverage */
+  u32 x, prev = 0;         /* Next and previous entry on the min-heap */
+  const char *saved_zPfx = pCheck->zPfx;
+  int saved_v1 = pCheck->v1;
+  int saved_v2 = pCheck->v2;
+  u8 savedIsInit = 0;
 
   /* Check that the page exists
   */
   pBt = pCheck->pBt;
   usableSize = pBt->usableSize;
   if( iPage==0 ) return 0;
-  if( checkRef(pCheck, iPage, zParentContext) ) return 0;
+  if( checkRef(pCheck, iPage) ) return 0;
+  pCheck->zPfx = "Page %d: ";
+  pCheck->v1 = iPage;
   if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
-    checkAppendMsg(pCheck, zContext,
+    checkAppendMsg(pCheck,
        "unable to get the page. error code=%d", rc);
-    return 0;
+    goto end_of_check;
   }
 
   /* Clear MemPage.isInit to make sure the corruption detection code in
   ** btreeInitPage() is executed.  */
+  savedIsInit = pPage->isInit;
   pPage->isInit = 0;
   if( (rc = btreeInitPage(pPage))!=0 ){
     assert( rc==SQLITE_CORRUPT );  /* The only possible error from InitPage */
-    checkAppendMsg(pCheck, zContext, 
+    checkAppendMsg(pCheck,
                    "btreeInitPage() returns error code %d", rc);
-    releasePage(pPage);
-    return 0;
+    goto end_of_check;
   }
+  data = pPage->aData;
+  hdr = pPage->hdrOffset;
 
-  /* Check out all the cells.
-  */
-  depth = 0;
-  for(i=0; i<pPage->nCell && pCheck->mxErr; i++){
-    u8 *pCell;
-    u32 sz;
+  /* Set up for cell analysis */
+  pCheck->zPfx = "On tree page %d cell %d: ";
+  contentOffset = get2byteNotZero(&data[hdr+5]);
+  assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
+
+  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+  ** number of cells on the page. */
+  nCell = get2byte(&data[hdr+3]);
+  assert( pPage->nCell==nCell );
+
+  /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
+  ** immediately follows the b-tree page header. */
+  cellStart = hdr + 12 - 4*pPage->leaf;
+  assert( pPage->aCellIdx==&data[cellStart] );
+  pCellIdx = &data[cellStart + 2*(nCell-1)];
+
+  if( !pPage->leaf ){
+    /* Analyze the right-child page of internal pages */
+    pgno = get4byte(&data[hdr+8]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    if( pBt->autoVacuum ){
+      pCheck->zPfx = "On page %d at right child: ";
+      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
+    }
+#endif
+    depth = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+    keyCanBeEqual = 0;
+  }else{
+    /* For leaf pages, the coverage check will occur in the same loop
+    ** as the other cell checks, so initialize the heap.  */
+    heap = pCheck->heap;
+    heap[0] = 0;
+  }
+
+  /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte
+  ** integer offsets to the cell contents. */
+  for(i=nCell-1; i>=0 && pCheck->mxErr; i--){
     CellInfo info;
 
-    /* Check payload overflow pages
-    */
-    sqlite3_snprintf(sizeof(zContext), zContext,
-             "On tree page %d cell %d: ", iPage, i);
-    pCell = findCell(pPage,i);
-    btreeParseCellPtr(pPage, pCell, &info);
-    sz = info.nData;
-    if( !pPage->intKey ) sz += (int)info.nKey;
-    /* For intKey pages, check that the keys are in order.
-    */
-    else if( i==0 ) nMinKey = nMaxKey = info.nKey;
-    else{
-      if( info.nKey <= nMaxKey ){
-        checkAppendMsg(pCheck, zContext, 
-            "Rowid %lld out of order (previous was %lld)", info.nKey, nMaxKey);
+    /* Check cell size */
+    pCheck->v2 = i;
+    assert( pCellIdx==&data[cellStart + i*2] );
+    pc = get2byteAligned(pCellIdx);
+    pCellIdx -= 2;
+    if( pc<contentOffset || pc>usableSize-4 ){
+      checkAppendMsg(pCheck, "Offset %d out of range %d..%d",
+                             pc, contentOffset, usableSize-4);
+      doCoverageCheck = 0;
+      continue;
+    }
+    pCell = &data[pc];
+    pPage->xParseCell(pPage, pCell, &info);
+    if( pc+info.nSize>usableSize ){
+      checkAppendMsg(pCheck, "Extends off end of page");
+      doCoverageCheck = 0;
+      continue;
+    }
+
+    /* Check for integer primary key out of range */
+    if( pPage->intKey ){
+      if( keyCanBeEqual ? (info.nKey > maxKey) : (info.nKey >= maxKey) ){
+        checkAppendMsg(pCheck, "Rowid %lld out of order", info.nKey);
       }
-      nMaxKey = info.nKey;
+      maxKey = info.nKey;
     }
-    assert( sz==info.nPayload );
-    if( (sz>info.nLocal) 
-     && (&pCell[info.iOverflow]<=&pPage->aData[pBt->usableSize])
-    ){
-      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
-      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
+
+    /* Check the content overflow list */
+    if( info.nPayload>info.nLocal ){
+      int nPage;       /* Number of pages on the overflow chain */
+      Pgno pgnoOvfl;   /* First page of the overflow chain */
+      assert( pc + info.nSize - 4 <= usableSize );
+      nPage = (info.nPayload - info.nLocal + usableSize - 5)/(usableSize - 4);
+      pgnoOvfl = get4byte(&pCell[info.nSize - 4]);
 #ifndef SQLITE_OMIT_AUTOVACUUM
       if( pBt->autoVacuum ){
-        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage, zContext);
+        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage);
       }
 #endif
-      checkList(pCheck, 0, pgnoOvfl, nPage, zContext);
+      checkList(pCheck, 0, pgnoOvfl, nPage);
     }
 
-    /* Check sanity of left child page.
-    */
     if( !pPage->leaf ){
+      /* Check sanity of left child page for internal pages */
       pgno = get4byte(pCell);
 #ifndef SQLITE_OMIT_AUTOVACUUM
       if( pBt->autoVacuum ){
-        checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, zContext);
+        checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
       }
 #endif
-      d2 = checkTreePage(pCheck, pgno, zContext, &nMinKey, i==0 ? NULL : &nMaxKey);
-      if( i>0 && d2!=depth ){
-        checkAppendMsg(pCheck, zContext, "Child page depth differs");
-      }
-      depth = d2;
-    }
-  }
-
-  if( !pPage->leaf ){
-    pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
-    sqlite3_snprintf(sizeof(zContext), zContext, 
-                     "On page %d at right child: ", iPage);
-#ifndef SQLITE_OMIT_AUTOVACUUM
-    if( pBt->autoVacuum ){
-      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage, zContext);
-    }
-#endif
-    checkTreePage(pCheck, pgno, zContext, NULL, !pPage->nCell ? NULL : &nMaxKey);
-  }
- 
-  /* For intKey leaf pages, check that the min/max keys are in order
-  ** with any left/parent/right pages.
-  */
-  if( pPage->leaf && pPage->intKey ){
-    /* if we are a left child page */
-    if( pnParentMinKey ){
-      /* if we are the left most child page */
-      if( !pnParentMaxKey ){
-        if( nMaxKey > *pnParentMinKey ){
-          checkAppendMsg(pCheck, zContext, 
-              "Rowid %lld out of order (max larger than parent min of %lld)",
-              nMaxKey, *pnParentMinKey);
-        }
-      }else{
-        if( nMinKey <= *pnParentMinKey ){
-          checkAppendMsg(pCheck, zContext, 
-              "Rowid %lld out of order (min less than parent min of %lld)",
-              nMinKey, *pnParentMinKey);
-        }
-        if( nMaxKey > *pnParentMaxKey ){
-          checkAppendMsg(pCheck, zContext, 
-              "Rowid %lld out of order (max larger than parent max of %lld)",
-              nMaxKey, *pnParentMaxKey);
-        }
-        *pnParentMinKey = nMaxKey;
-      }
-    /* else if we're a right child page */
-    } else if( pnParentMaxKey ){
-      if( nMinKey <= *pnParentMaxKey ){
-        checkAppendMsg(pCheck, zContext, 
-            "Rowid %lld out of order (min less than parent max of %lld)",
-            nMinKey, *pnParentMaxKey);
+      d2 = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+      keyCanBeEqual = 0;
+      if( d2!=depth ){
+        checkAppendMsg(pCheck, "Child page depth differs");
+        depth = d2;
       }
+    }else{
+      /* Populate the coverage-checking heap for leaf pages */
+      btreeHeapInsert(heap, (pc<<16)|(pc+info.nSize-1));
     }
   }
+  *piMinKey = maxKey;
 
   /* Check for complete coverage of the page
   */
-  data = pPage->aData;
-  hdr = pPage->hdrOffset;
-  hit = sqlite3PageMalloc( pBt->pageSize );
-  if( hit==0 ){
-    pCheck->mallocFailed = 1;
-  }else{
-    int contentOffset = get2byteNotZero(&data[hdr+5]);
-    assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */
-    memset(hit+contentOffset, 0, usableSize-contentOffset);
-    memset(hit, 1, contentOffset);
-    nCell = get2byte(&data[hdr+3]);
-    cellStart = hdr + 12 - 4*pPage->leaf;
-    for(i=0; i<nCell; i++){
-      int pc = get2byte(&data[cellStart+i*2]);
-      u32 size = 65536;
-      int j;
-      if( pc<=usableSize-4 ){
-        size = cellSizePtr(pPage, &data[pc]);
-      }
-      if( (int)(pc+size-1)>=usableSize ){
-        checkAppendMsg(pCheck, 0, 
-            "Corruption detected in cell %d on page %d",i,iPage);
-      }else{
-        for(j=pc+size-1; j>=pc; j--) hit[j]++;
+  pCheck->zPfx = 0;
+  if( doCoverageCheck && pCheck->mxErr>0 ){
+    /* For leaf pages, the min-heap has already been initialized and the
+    ** cells have already been inserted.  But for internal pages, that has
+    ** not yet been done, so do it now */
+    if( !pPage->leaf ){
+      heap = pCheck->heap;
+      heap[0] = 0;
+      for(i=nCell-1; i>=0; i--){
+        u32 size;
+        pc = get2byteAligned(&data[cellStart+i*2]);
+        size = pPage->xCellSize(pPage, &data[pc]);
+        btreeHeapInsert(heap, (pc<<16)|(pc+size-1));
       }
     }
+    /* Add the freeblocks to the min-heap
+    **
+    ** EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header
+    ** is the offset of the first freeblock, or zero if there are no
+    ** freeblocks on the page. 
+    */
     i = get2byte(&data[hdr+1]);
     while( i>0 ){
       int size, j;
-      assert( i<=usableSize-4 );     /* Enforced by btreeInitPage() */
+      assert( (u32)i<=usableSize-4 );     /* Enforced by btreeInitPage() */
       size = get2byte(&data[i+2]);
-      assert( i+size<=usableSize );  /* Enforced by btreeInitPage() */
-      for(j=i+size-1; j>=i; j--) hit[j]++;
+      assert( (u32)(i+size)<=usableSize );  /* Enforced by btreeInitPage() */
+      btreeHeapInsert(heap, (((u32)i)<<16)|(i+size-1));
+      /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a
+      ** big-endian integer which is the offset in the b-tree page of the next
+      ** freeblock in the chain, or zero if the freeblock is the last on the
+      ** chain. */
       j = get2byte(&data[i]);
+      /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
+      ** increasing offset. */
       assert( j==0 || j>i+size );  /* Enforced by btreeInitPage() */
-      assert( j<=usableSize-4 );   /* Enforced by btreeInitPage() */
+      assert( (u32)j<=usableSize-4 );   /* Enforced by btreeInitPage() */
       i = j;
     }
-    for(i=cnt=0; i<usableSize; i++){
-      if( hit[i]==0 ){
-        cnt++;
-      }else if( hit[i]>1 ){
-        checkAppendMsg(pCheck, 0,
-          "Multiple uses for byte %d of page %d", i, iPage);
+    /* Analyze the min-heap looking for overlap between cells and/or 
+    ** freeblocks, and counting the number of untracked bytes in nFrag.
+    ** 
+    ** Each min-heap entry is of the form:    (start_address<<16)|end_address.
+    ** There is an implied first entry the covers the page header, the cell
+    ** pointer index, and the gap between the cell pointer index and the start
+    ** of cell content.  
+    **
+    ** The loop below pulls entries from the min-heap in order and compares
+    ** the start_address against the previous end_address.  If there is an
+    ** overlap, that means bytes are used multiple times.  If there is a gap,
+    ** that gap is added to the fragmentation count.
+    */
+    nFrag = 0;
+    prev = contentOffset - 1;   /* Implied first min-heap entry */
+    while( btreeHeapPull(heap,&x) ){
+      if( (prev&0xffff)>=(x>>16) ){
+        checkAppendMsg(pCheck,
+          "Multiple uses for byte %u of page %d", x>>16, iPage);
         break;
+      }else{
+        nFrag += (x>>16) - (prev&0xffff) - 1;
+        prev = x;
       }
     }
-    if( cnt!=data[hdr+7] ){
-      checkAppendMsg(pCheck, 0, 
+    nFrag += usableSize - (prev&0xffff) - 1;
+    /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments
+    ** is stored in the fifth field of the b-tree page header.
+    ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the
+    ** number of fragmented free bytes within the cell content area.
+    */
+    if( heap[0]==0 && nFrag!=data[hdr+7] ){
+      checkAppendMsg(pCheck,
           "Fragmentation of %d bytes reported as %d on page %d",
-          cnt, data[hdr+7], iPage);
+          nFrag, data[hdr+7], iPage);
     }
   }
-  sqlite3PageFree(hit);
+
+end_of_check:
+  if( !doCoverageCheck ) pPage->isInit = savedIsInit;
   releasePage(pPage);
+  pCheck->zPfx = saved_zPfx;
+  pCheck->v1 = saved_v1;
+  pCheck->v2 = saved_v2;
   return depth+1;
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
@@ -55963,113 +67458,120 @@ SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(
   int *pnErr    /* Write number of errors seen to this variable */
 ){
   Pgno i;
-  int nRef;
   IntegrityCk sCheck;
   BtShared *pBt = p->pBt;
+  int savedDbFlags = pBt->db->flags;
   char zErr[100];
+  VVA_ONLY( int nRef );
 
   sqlite3BtreeEnter(p);
   assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );
-  nRef = sqlite3PagerRefcount(pBt->pPager);
+  VVA_ONLY( nRef = sqlite3PagerRefcount(pBt->pPager) );
+  assert( nRef>=0 );
   sCheck.pBt = pBt;
   sCheck.pPager = pBt->pPager;
   sCheck.nPage = btreePagecount(sCheck.pBt);
   sCheck.mxErr = mxErr;
   sCheck.nErr = 0;
   sCheck.mallocFailed = 0;
-  *pnErr = 0;
+  sCheck.zPfx = 0;
+  sCheck.v1 = 0;
+  sCheck.v2 = 0;
+  sCheck.aPgRef = 0;
+  sCheck.heap = 0;
+  sqlite3StrAccumInit(&sCheck.errMsg, 0, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
+  sCheck.errMsg.printfFlags = SQLITE_PRINTF_INTERNAL;
   if( sCheck.nPage==0 ){
-    sqlite3BtreeLeave(p);
-    return 0;
+    goto integrity_ck_cleanup;
   }
-  sCheck.anRef = sqlite3Malloc( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
-  if( !sCheck.anRef ){
-    *pnErr = 1;
-    sqlite3BtreeLeave(p);
-    return 0;
+
+  sCheck.aPgRef = sqlite3MallocZero((sCheck.nPage / 8)+ 1);
+  if( !sCheck.aPgRef ){
+    sCheck.mallocFailed = 1;
+    goto integrity_ck_cleanup;
   }
-  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
-  i = PENDING_BYTE_PAGE(pBt);
-  if( i<=sCheck.nPage ){
-    sCheck.anRef[i] = 1;
+  sCheck.heap = (u32*)sqlite3PageMalloc( pBt->pageSize );
+  if( sCheck.heap==0 ){
+    sCheck.mallocFailed = 1;
+    goto integrity_ck_cleanup;
   }
-  sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), 20000);
-  sCheck.errMsg.useMalloc = 2;
+
+  i = PENDING_BYTE_PAGE(pBt);
+  if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);
 
   /* Check the integrity of the freelist
   */
+  sCheck.zPfx = "Main freelist: ";
   checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
-            get4byte(&pBt->pPage1->aData[36]), "Main freelist: ");
+            get4byte(&pBt->pPage1->aData[36]));
+  sCheck.zPfx = 0;
 
   /* Check all the tables.
   */
+  testcase( pBt->db->flags & SQLITE_CellSizeCk );
+  pBt->db->flags &= ~SQLITE_CellSizeCk;
   for(i=0; (int)i<nRoot && sCheck.mxErr; i++){
+    i64 notUsed;
     if( aRoot[i]==0 ) continue;
 #ifndef SQLITE_OMIT_AUTOVACUUM
     if( pBt->autoVacuum && aRoot[i]>1 ){
-      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0, 0);
+      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0);
     }
 #endif
-    checkTreePage(&sCheck, aRoot[i], "List of tree roots: ", NULL, NULL);
+    checkTreePage(&sCheck, aRoot[i], &notUsed, LARGEST_INT64);
   }
+  pBt->db->flags = savedDbFlags;
 
   /* Make sure every page in the file is referenced
   */
   for(i=1; i<=sCheck.nPage && sCheck.mxErr; i++){
 #ifdef SQLITE_OMIT_AUTOVACUUM
-    if( sCheck.anRef[i]==0 ){
-      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
+    if( getPageReferenced(&sCheck, i)==0 ){
+      checkAppendMsg(&sCheck, "Page %d is never used", i);
     }
 #else
     /* If the database supports auto-vacuum, make sure no tables contain
     ** references to pointer-map pages.
     */
-    if( sCheck.anRef[i]==0 && 
+    if( getPageReferenced(&sCheck, i)==0 && 
        (PTRMAP_PAGENO(pBt, i)!=i || !pBt->autoVacuum) ){
-      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
+      checkAppendMsg(&sCheck, "Page %d is never used", i);
     }
-    if( sCheck.anRef[i]!=0 && 
+    if( getPageReferenced(&sCheck, i)!=0 && 
        (PTRMAP_PAGENO(pBt, i)==i && pBt->autoVacuum) ){
-      checkAppendMsg(&sCheck, 0, "Pointer map page %d is referenced", i);
+      checkAppendMsg(&sCheck, "Pointer map page %d is referenced", i);
     }
 #endif
   }
 
-  /* Make sure this analysis did not leave any unref() pages.
-  ** This is an internal consistency check; an integrity check
-  ** of the integrity check.
-  */
-  if( NEVER(nRef != sqlite3PagerRefcount(pBt->pPager)) ){
-    checkAppendMsg(&sCheck, 0, 
-      "Outstanding page count goes from %d to %d during this analysis",
-      nRef, sqlite3PagerRefcount(pBt->pPager)
-    );
-  }
-
   /* Clean  up and report errors.
   */
-  sqlite3BtreeLeave(p);
-  sqlite3_free(sCheck.anRef);
+integrity_ck_cleanup:
+  sqlite3PageFree(sCheck.heap);
+  sqlite3_free(sCheck.aPgRef);
   if( sCheck.mallocFailed ){
     sqlite3StrAccumReset(&sCheck.errMsg);
-    *pnErr = sCheck.nErr+1;
-    return 0;
+    sCheck.nErr++;
   }
   *pnErr = sCheck.nErr;
   if( sCheck.nErr==0 ) sqlite3StrAccumReset(&sCheck.errMsg);
+  /* Make sure this analysis did not leave any unref() pages. */
+  assert( nRef==sqlite3PagerRefcount(pBt->pPager) );
+  sqlite3BtreeLeave(p);
   return sqlite3StrAccumFinish(&sCheck.errMsg);
 }
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
 /*
-** Return the full pathname of the underlying database file.
+** Return the full pathname of the underlying database file.  Return
+** an empty string if the database is in-memory or a TEMP database.
 **
 ** The pager filename is invariant as long as the pager is
 ** open so it is safe to access without the BtShared mutex.
 */
 SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *p){
   assert( p->pBt->pPager!=0 );
-  return sqlite3PagerFilename(p->pBt->pPager);
+  return sqlite3PagerFilename(p->pBt->pPager, 1);
 }
 
 /*
@@ -56218,9 +67720,9 @@ SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *p, int iTab, u8 isWriteLock){
 */
 SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
   int rc;
-  assert( cursorHoldsMutex(pCsr) );
+  assert( cursorOwnsBtShared(pCsr) );
   assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );
-  assert( pCsr->isIncrblobHandle );
+  assert( pCsr->curFlags & BTCF_Incrblob );
 
   rc = restoreCursorPosition(pCsr);
   if( rc!=SQLITE_OK ){
@@ -56231,6 +67733,17 @@ SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void
     return SQLITE_ABORT;
   }
 
+  /* Save the positions of all other cursors open on this table. This is
+  ** required in case any of them are holding references to an xFetch
+  ** version of the b-tree page modified by the accessPayload call below.
+  **
+  ** Note that pCsr must be open on a INTKEY table and saveCursorPosition()
+  ** and hence saveAllCursors() cannot fail on a BTREE_INTKEY table, hence
+  ** saveAllCursors can only return SQLITE_OK.
+  */
+  VVA_ONLY(rc =) saveAllCursors(pCsr->pBt, pCsr->pgnoRoot, pCsr);
+  assert( rc==SQLITE_OK );
+
   /* Check some assumptions: 
   **   (a) the cursor is open for writing,
   **   (b) there is a read/write transaction open,
@@ -56238,10 +67751,11 @@ SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void
   **   (d) there are no conflicting read-locks, and
   **   (e) the cursor points at a valid row of an intKey table.
   */
-  if( !pCsr->wrFlag ){
+  if( (pCsr->curFlags & BTCF_WriteFlag)==0 ){
     return SQLITE_READONLY;
   }
-  assert( !pCsr->pBt->readOnly && pCsr->pBt->inTransaction==TRANS_WRITE );
+  assert( (pCsr->pBt->btsFlags & BTS_READ_ONLY)==0
+              && pCsr->pBt->inTransaction==TRANS_WRITE );
   assert( hasSharedCacheTableLock(pCsr->pBtree, pCsr->pgnoRoot, 0, 2) );
   assert( !hasReadConflicts(pCsr->pBtree, pCsr->pgnoRoot) );
   assert( pCsr->apPage[pCsr->iPage]->intKey );
@@ -56250,20 +67764,11 @@ SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void
 }
 
 /* 
-** Set a flag on this cursor to cache the locations of pages from the 
-** overflow list for the current row. This is used by cursors opened
-** for incremental blob IO only.
-**
-** This function sets a flag only. The actual page location cache
-** (stored in BtCursor.aOverflow[]) is allocated and used by function
-** accessPayload() (the worker function for sqlite3BtreeData() and
-** sqlite3BtreePutData()).
+** Mark this cursor as an incremental blob cursor.
 */
-SQLITE_PRIVATE void sqlite3BtreeCacheOverflow(BtCursor *pCur){
-  assert( cursorHoldsMutex(pCur) );
-  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  invalidateOverflowCache(pCur);
-  pCur->isIncrblobHandle = 1;
+SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *pCur){
+  pCur->curFlags |= BTCF_Incrblob;
+  pCur->pBtree->hasIncrblobCur = 1;
 }
 #endif
 
@@ -56281,7 +67786,8 @@ SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
   /* If setting the version fields to 1, do not automatically open the
   ** WAL connection, even if the version fields are currently set to 2.
   */
-  pBt->doNotUseWAL = (u8)(iVersion==1);
+  pBt->btsFlags &= ~BTS_NO_WAL;
+  if( iVersion==1 ) pBt->btsFlags |= BTS_NO_WAL;
 
   rc = sqlite3BtreeBeginTrans(pBtree, 0);
   if( rc==SQLITE_OK ){
@@ -56298,10 +67804,49 @@ SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
     }
   }
 
-  pBt->doNotUseWAL = 0;
+  pBt->btsFlags &= ~BTS_NO_WAL;
   return rc;
 }
 
+/*
+** Return true if the cursor has a hint specified.  This routine is
+** only used from within assert() statements
+*/
+SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor *pCsr, unsigned int mask){
+  return (pCsr->hints & mask)!=0;
+}
+
+/*
+** Return true if the given Btree is read-only.
+*/
+SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *p){
+  return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
+}
+
+/*
+** Return the size of the header added to each page by this module.
+*/
+SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
+
+#if !defined(SQLITE_OMIT_SHARED_CACHE)
+/*
+** Return true if the Btree passed as the only argument is sharable.
+*/
+SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
+  return p->sharable;
+}
+
+/*
+** Return the number of connections to the BtShared object accessed by
+** the Btree handle passed as the only argument. For private caches 
+** this is always 1. For shared caches it may be 1 or greater.
+*/
+SQLITE_PRIVATE int sqlite3BtreeConnectionCount(Btree *p){
+  testcase( p->sharable );
+  return p->pBt->nRef;
+}
+#endif
+
 /************** End of btree.c ***********************************************/
 /************** Begin file backup.c ******************************************/
 /*
@@ -56318,12 +67863,8 @@ SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
 ** This file contains the implementation of the sqlite3_backup_XXX() 
 ** API functions and the related features.
 */
-
-/* Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
+/* #include "sqliteInt.h" */
+/* #include "btreeInt.h" */
 
 /*
 ** Structure allocated for each backup operation.
@@ -56397,15 +67938,16 @@ static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
     int rc = 0;
     pParse = sqlite3StackAllocZero(pErrorDb, sizeof(*pParse));
     if( pParse==0 ){
-      sqlite3Error(pErrorDb, SQLITE_NOMEM, "out of memory");
-      rc = SQLITE_NOMEM;
+      sqlite3ErrorWithMsg(pErrorDb, SQLITE_NOMEM, "out of memory");
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       pParse->db = pDb;
       if( sqlite3OpenTempDatabase(pParse) ){
-        sqlite3Error(pErrorDb, pParse->rc, "%s", pParse->zErrMsg);
+        sqlite3ErrorWithMsg(pErrorDb, pParse->rc, "%s", pParse->zErrMsg);
         rc = SQLITE_ERROR;
       }
       sqlite3DbFree(pErrorDb, pParse->zErrMsg);
+      sqlite3ParserReset(pParse);
       sqlite3StackFree(pErrorDb, pParse);
     }
     if( rc ){
@@ -56414,7 +67956,7 @@ static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
   }
 
   if( i<0 ){
-    sqlite3Error(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);
+    sqlite3ErrorWithMsg(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);
     return 0;
   }
 
@@ -56432,6 +67974,20 @@ static int setDestPgsz(sqlite3_backup *p){
 }
 
 /*
+** Check that there is no open read-transaction on the b-tree passed as the
+** second argument. If there is not, return SQLITE_OK. Otherwise, if there
+** is an open read-transaction, return SQLITE_ERROR and leave an error 
+** message in database handle db.
+*/
+static int checkReadTransaction(sqlite3 *db, Btree *p){
+  if( sqlite3BtreeIsInReadTrans(p) ){
+    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
+    return SQLITE_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
 ** Create an sqlite3_backup process to copy the contents of zSrcDb from
 ** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
 ** a pointer to the new sqlite3_backup object.
@@ -56439,7 +67995,7 @@ static int setDestPgsz(sqlite3_backup *p){
 ** If an error occurs, NULL is returned and an error code and error message
 ** stored in database handle pDestDb.
 */
-SQLITE_API sqlite3_backup *sqlite3_backup_init(
+SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init(
   sqlite3* pDestDb,                     /* Database to write to */
   const char *zDestDb,                  /* Name of database within pDestDb */
   sqlite3* pSrcDb,                      /* Database connection to read from */
@@ -56447,6 +68003,13 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
 ){
   sqlite3_backup *p;                    /* Value to return */
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(pSrcDb)||!sqlite3SafetyCheckOk(pDestDb) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+
   /* Lock the source database handle. The destination database
   ** handle is not locked in this routine, but it is locked in
   ** sqlite3_backup_step(). The user is required to ensure that no
@@ -56459,7 +68022,7 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
   sqlite3_mutex_enter(pDestDb->mutex);
 
   if( pSrcDb==pDestDb ){
-    sqlite3Error(
+    sqlite3ErrorWithMsg(
         pDestDb, SQLITE_ERROR, "source and destination must be distinct"
     );
     p = 0;
@@ -56468,15 +68031,14 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
     ** EVIDENCE-OF: R-64852-21591 The sqlite3_backup object is created by a
     ** call to sqlite3_backup_init() and is destroyed by a call to
     ** sqlite3_backup_finish(). */
-    p = (sqlite3_backup *)sqlite3_malloc(sizeof(sqlite3_backup));
+    p = (sqlite3_backup *)sqlite3MallocZero(sizeof(sqlite3_backup));
     if( !p ){
-      sqlite3Error(pDestDb, SQLITE_NOMEM, 0);
+      sqlite3Error(pDestDb, SQLITE_NOMEM_BKPT);
     }
   }
 
   /* If the allocation succeeded, populate the new object. */
   if( p ){
-    memset(p, 0, sizeof(sqlite3_backup));
     p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);
     p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
     p->pDestDb = pDestDb;
@@ -56484,12 +68046,15 @@ SQLITE_API sqlite3_backup *sqlite3_backup_init(
     p->iNext = 1;
     p->isAttached = 0;
 
-    if( 0==p->pSrc || 0==p->pDest || setDestPgsz(p)==SQLITE_NOMEM ){
+    if( 0==p->pSrc || 0==p->pDest 
+     || setDestPgsz(p)==SQLITE_NOMEM 
+     || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 
+     ){
       /* One (or both) of the named databases did not exist or an OOM
-      ** error was hit.  The error has already been written into the
-      ** pDestDb handle.  All that is left to do here is free the
-      ** sqlite3_backup structure.
-      */
+      ** error was hit. Or there is a transaction open on the destination
+      ** database. The error has already been written into the pDestDb 
+      ** handle. All that is left to do here is free the sqlite3_backup 
+      ** structure.  */
       sqlite3_free(p);
       p = 0;
     }
@@ -56517,20 +68082,28 @@ static int isFatalError(int rc){
 ** page iSrcPg from the source database. Copy this data into the 
 ** destination database.
 */
-static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
+static int backupOnePage(
+  sqlite3_backup *p,              /* Backup handle */
+  Pgno iSrcPg,                    /* Source database page to backup */
+  const u8 *zSrcData,             /* Source database page data */
+  int bUpdate                     /* True for an update, false otherwise */
+){
   Pager * const pDestPager = sqlite3BtreePager(p->pDest);
   const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
   int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
   const int nCopy = MIN(nSrcPgsz, nDestPgsz);
   const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;
 #ifdef SQLITE_HAS_CODEC
-  int nSrcReserve = sqlite3BtreeGetReserve(p->pSrc);
-  int nDestReserve = sqlite3BtreeGetReserve(p->pDest);
+  /* Use BtreeGetReserveNoMutex() for the source b-tree, as although it is
+  ** guaranteed that the shared-mutex is held by this thread, handle
+  ** p->pSrc may not actually be the owner.  */
+  int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);
+  int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);
 #endif
-
   int rc = SQLITE_OK;
   i64 iOff;
 
+  assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );
   assert( p->bDestLocked );
   assert( !isFatalError(p->rc) );
   assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
@@ -56571,7 +68144,7 @@ static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
     DbPage *pDestPg = 0;
     Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;
     if( iDest==PENDING_BYTE_PAGE(p->pDest->pBt) ) continue;
-    if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg))
+    if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg, 0))
      && SQLITE_OK==(rc = sqlite3PagerWrite(pDestPg))
     ){
       const u8 *zIn = &zSrcData[iOff%nSrcPgsz];
@@ -56587,6 +68160,9 @@ static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
       */
       memcpy(zOut, zIn, nCopy);
       ((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;
+      if( iOff==0 && bUpdate==0 ){
+        sqlite3Put4byte(&zOut[28], sqlite3BtreeLastPage(p->pSrc));
+      }
     }
     sqlite3PagerUnref(pDestPg);
   }
@@ -56627,12 +68203,15 @@ static void attachBackupObject(sqlite3_backup *p){
 /*
 ** Copy nPage pages from the source b-tree to the destination.
 */
-SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage){
   int rc;
   int destMode;       /* Destination journal mode */
   int pgszSrc = 0;    /* Source page size */
   int pgszDest = 0;   /* Destination page size */
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( p==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(p->pSrcDb->mutex);
   sqlite3BtreeEnter(p->pSrc);
   if( p->pDestDb ){
@@ -56691,9 +68270,9 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       const Pgno iSrcPg = p->iNext;                 /* Source page number */
       if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){
         DbPage *pSrcPg;                             /* Source page object */
-        rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
+        rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg,PAGER_GET_READONLY);
         if( rc==SQLITE_OK ){
-          rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg));
+          rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);
           sqlite3PagerUnref(pSrcPg);
         }
       }
@@ -56715,10 +68294,16 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     ** same schema version.
     */
     if( rc==SQLITE_DONE ){
-      rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);
+      if( nSrcPage==0 ){
+        rc = sqlite3BtreeNewDb(p->pDest);
+        nSrcPage = 1;
+      }
+      if( rc==SQLITE_OK || rc==SQLITE_DONE ){
+        rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);
+      }
       if( rc==SQLITE_OK ){
         if( p->pDestDb ){
-          sqlite3ResetInternalSchema(p->pDestDb, -1);
+          sqlite3ResetAllSchemasOfConnection(p->pDestDb);
         }
         if( destMode==PAGER_JOURNALMODE_WAL ){
           rc = sqlite3BtreeSetVersion(p->pDest, 2);
@@ -56749,7 +68334,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
         }else{
           nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
         }
-        sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
+        assert( nDestTruncate>0 );
 
         if( pgszSrc<pgszDest ){
           /* If the source page-size is smaller than the destination page-size,
@@ -56763,22 +68348,38 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           */
           const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
           sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
+          Pgno iPg;
+          int nDstPage;
           i64 iOff;
           i64 iEnd;
 
           assert( pFile );
-          assert( (i64)nDestTruncate*(i64)pgszDest >= iSize || (
+          assert( nDestTruncate==0 
+              || (i64)nDestTruncate*(i64)pgszDest >= iSize || (
                 nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)
              && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
           ));
 
-          /* This call ensures that all data required to recreate the original
+          /* This block ensures that all data required to recreate the original
           ** database has been stored in the journal for pDestPager and the
           ** journal synced to disk. So at this point we may safely modify
           ** the database file in any way, knowing that if a power failure
           ** occurs, the original database will be reconstructed from the 
           ** journal file.  */
-          rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          sqlite3PagerPagecount(pDestPager, &nDstPage);
+          for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){
+            if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){
+              DbPage *pPg;
+              rc = sqlite3PagerGet(pDestPager, iPg, &pPg, 0);
+              if( rc==SQLITE_OK ){
+                rc = sqlite3PagerWrite(pPg);
+                sqlite3PagerUnref(pPg);
+              }
+            }
+          }
+          if( rc==SQLITE_OK ){
+            rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          }
 
           /* Write the extra pages and truncate the database file as required */
           iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
@@ -56789,7 +68390,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           ){
             PgHdr *pSrcPg = 0;
             const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
-            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg);
+            rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg, 0);
             if( rc==SQLITE_OK ){
               u8 *zData = sqlite3PagerGetData(pSrcPg);
               rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
@@ -56802,9 +68403,10 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
 
           /* Sync the database file to disk. */
           if( rc==SQLITE_OK ){
-            rc = sqlite3PagerSync(pDestPager);
+            rc = sqlite3PagerSync(pDestPager, 0);
           }
         }else{
+          sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
           rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
         }
     
@@ -56830,7 +68432,7 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     }
   
     if( rc==SQLITE_IOERR_NOMEM ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
     p->rc = rc;
   }
@@ -56845,16 +68447,16 @@ SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
 /*
 ** Release all resources associated with an sqlite3_backup* handle.
 */
-SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p){
   sqlite3_backup **pp;                 /* Ptr to head of pagers backup list */
-  MUTEX_LOGIC( sqlite3_mutex *mutex; ) /* Mutex to protect source database */
+  sqlite3 *pSrcDb;                     /* Source database connection */
   int rc;                              /* Value to return */
 
   /* Enter the mutexes */
   if( p==0 ) return SQLITE_OK;
-  sqlite3_mutex_enter(p->pSrcDb->mutex);
+  pSrcDb = p->pSrcDb;
+  sqlite3_mutex_enter(pSrcDb->mutex);
   sqlite3BtreeEnter(p->pSrc);
-  MUTEX_LOGIC( mutex = p->pSrcDb->mutex; )
   if( p->pDestDb ){
     sqlite3_mutex_enter(p->pDestDb->mutex);
   }
@@ -56872,15 +68474,15 @@ SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){
   }
 
   /* If a transaction is still open on the Btree, roll it back. */
-  sqlite3BtreeRollback(p->pDest);
+  sqlite3BtreeRollback(p->pDest, SQLITE_OK, 0);
 
   /* Set the error code of the destination database handle. */
   rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
-  sqlite3Error(p->pDestDb, rc, 0);
-
-  /* Exit the mutexes and free the backup context structure. */
   if( p->pDestDb ){
-    sqlite3_mutex_leave(p->pDestDb->mutex);
+    sqlite3Error(p->pDestDb, rc);
+
+    /* Exit the mutexes and free the backup context structure. */
+    sqlite3LeaveMutexAndCloseZombie(p->pDestDb);
   }
   sqlite3BtreeLeave(p->pSrc);
   if( p->pDestDb ){
@@ -56889,7 +68491,7 @@ SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){
     ** sqlite3_backup_finish(). */
     sqlite3_free(p);
   }
-  sqlite3_mutex_leave(mutex);
+  sqlite3LeaveMutexAndCloseZombie(pSrcDb);
   return rc;
 }
 
@@ -56897,7 +68499,13 @@ SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){
 ** Return the number of pages still to be backed up as of the most recent
 ** call to sqlite3_backup_step().
 */
-SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( p==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return p->nRemaining;
 }
 
@@ -56905,7 +68513,13 @@ SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p){
 ** Return the total number of pages in the source database as of the most 
 ** recent call to sqlite3_backup_step().
 */
-SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p){
+SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( p==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return p->nPagecount;
 }
 
@@ -56921,9 +68535,13 @@ SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p){
 ** corresponding to the source database is held when this function is
 ** called.
 */
-SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
-  sqlite3_backup *p;                   /* Iterator variable */
-  for(p=pBackup; p; p=p->pNext){
+static SQLITE_NOINLINE void backupUpdate(
+  sqlite3_backup *p,
+  Pgno iPage,
+  const u8 *aData
+){
+  assert( p!=0 );
+  do{
     assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );
     if( !isFatalError(p->rc) && iPage<p->iNext ){
       /* The backup process p has already copied page iPage. But now it
@@ -56933,14 +68551,17 @@ SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, con
       int rc;
       assert( p->pDestDb );
       sqlite3_mutex_enter(p->pDestDb->mutex);
-      rc = backupOnePage(p, iPage, aData);
+      rc = backupOnePage(p, iPage, aData, 1);
       sqlite3_mutex_leave(p->pDestDb->mutex);
       assert( rc!=SQLITE_BUSY && rc!=SQLITE_LOCKED );
       if( rc!=SQLITE_OK ){
         p->rc = rc;
       }
     }
-  }
+  }while( (p = p->pNext)!=0 );
+}
+SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
+  if( pBackup ) backupUpdate(pBackup, iPage, aData);
 }
 
 /*
@@ -56982,7 +68603,9 @@ SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
   pFd = sqlite3PagerFile(sqlite3BtreePager(pTo));
   if( pFd->pMethods ){
     i64 nByte = sqlite3BtreeGetPageSize(pFrom)*(i64)sqlite3BtreeLastPage(pFrom);
-    sqlite3OsFileControl(pFd, SQLITE_FCNTL_OVERWRITE, &nByte);
+    rc = sqlite3OsFileControl(pFd, SQLITE_FCNTL_OVERWRITE, &nByte);
+    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+    if( rc ) goto copy_finished;
   }
 
   /* Set up an sqlite3_backup object. sqlite3_backup.pDestDb must be set
@@ -56996,23 +68619,28 @@ SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
   b.pDest = pTo;
   b.iNext = 1;
 
+#ifdef SQLITE_HAS_CODEC
+  sqlite3PagerAlignReserve(sqlite3BtreePager(pTo), sqlite3BtreePager(pFrom));
+#endif
+
   /* 0x7FFFFFFF is the hard limit for the number of pages in a database
   ** file. By passing this as the number of pages to copy to
   ** sqlite3_backup_step(), we can guarantee that the copy finishes 
   ** within a single call (unless an error occurs). The assert() statement
   ** checks this assumption - (p->rc) should be set to either SQLITE_DONE 
-  ** or an error code.
-  */
+  ** or an error code.  */
   sqlite3_backup_step(&b, 0x7FFFFFFF);
   assert( b.rc!=SQLITE_OK );
+
   rc = sqlite3_backup_finish(&b);
   if( rc==SQLITE_OK ){
-    pTo->pBt->pageSizeFixed = 0;
+    pTo->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;
   }else{
     sqlite3PagerClearCache(sqlite3BtreePager(b.pDest));
   }
 
   assert( sqlite3BtreeIsInTrans(pTo)==0 );
+copy_finished:
   sqlite3BtreeLeave(pFrom);
   sqlite3BtreeLeave(pTo);
   return rc;
@@ -57038,12 +68666,55 @@ SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
 ** only within the VDBE.  Interface routines refer to a Mem using the
 ** name sqlite_value
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
+#ifdef SQLITE_DEBUG
 /*
-** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
-** P if required.
+** Check invariants on a Mem object.
+**
+** This routine is intended for use inside of assert() statements, like
+** this:    assert( sqlite3VdbeCheckMemInvariants(pMem) );
 */
-#define expandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
+SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem *p){
+  /* If MEM_Dyn is set then Mem.xDel!=0.  
+  ** Mem.xDel is might not be initialized if MEM_Dyn is clear.
+  */
+  assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );
+
+  /* MEM_Dyn may only be set if Mem.szMalloc==0.  In this way we
+  ** ensure that if Mem.szMalloc>0 then it is safe to do
+  ** Mem.z = Mem.zMalloc without having to check Mem.flags&MEM_Dyn.
+  ** That saves a few cycles in inner loops. */
+  assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 );
+
+  /* Cannot be both MEM_Int and MEM_Real at the same time */
+  assert( (p->flags & (MEM_Int|MEM_Real))!=(MEM_Int|MEM_Real) );
+
+  /* The szMalloc field holds the correct memory allocation size */
+  assert( p->szMalloc==0
+       || p->szMalloc==sqlite3DbMallocSize(p->db,p->zMalloc) );
+
+  /* If p holds a string or blob, the Mem.z must point to exactly
+  ** one of the following:
+  **
+  **   (1) Memory in Mem.zMalloc and managed by the Mem object
+  **   (2) Memory to be freed using Mem.xDel
+  **   (3) An ephemeral string or blob
+  **   (4) A static string or blob
+  */
+  if( (p->flags & (MEM_Str|MEM_Blob)) && p->n>0 ){
+    assert( 
+      ((p->szMalloc>0 && p->z==p->zMalloc)? 1 : 0) +
+      ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
+      ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +
+      ((p->flags&MEM_Static)!=0 ? 1 : 0) == 1
+    );
+  }
+  return 1;
+}
+#endif
+
 
 /*
 ** If pMem is an object with a valid string representation, this routine
@@ -57059,7 +68730,9 @@ SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
 ** between formats.
 */
 SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
+#ifndef SQLITE_OMIT_UTF16
   int rc;
+#endif
   assert( (pMem->flags&MEM_RowSet)==0 );
   assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
            || desiredEnc==SQLITE_UTF16BE );
@@ -57084,59 +68757,85 @@ SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 
 /*
 ** Make sure pMem->z points to a writable allocation of at least 
-** n bytes.
-**
-** If the memory cell currently contains string or blob data
-** and the third argument passed to this function is true, the 
-** current content of the cell is preserved. Otherwise, it may
-** be discarded.  
-**
-** This function sets the MEM_Dyn flag and clears any xDel callback.
-** It also clears MEM_Ephem and MEM_Static. If the preserve flag is 
-** not set, Mem.n is zeroed.
-*/
-SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
-  assert( 1 >=
-    ((pMem->zMalloc && pMem->zMalloc==pMem->z) ? 1 : 0) +
-    (((pMem->flags&MEM_Dyn)&&pMem->xDel) ? 1 : 0) + 
-    ((pMem->flags&MEM_Ephem) ? 1 : 0) + 
-    ((pMem->flags&MEM_Static) ? 1 : 0)
-  );
+** min(n,32) bytes.
+**
+** If the bPreserve argument is true, then copy of the content of
+** pMem->z into the new allocation.  pMem must be either a string or
+** blob if bPreserve is true.  If bPreserve is false, any prior content
+** in pMem->z is discarded.
+*/
+SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
+  assert( sqlite3VdbeCheckMemInvariants(pMem) );
   assert( (pMem->flags&MEM_RowSet)==0 );
-
-  if( n<32 ) n = 32;
-  if( sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
-    if( preserve && pMem->z==pMem->zMalloc ){
+  testcase( pMem->db==0 );
+
+  /* If the bPreserve flag is set to true, then the memory cell must already
+  ** contain a valid string or blob value.  */
+  assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
+  testcase( bPreserve && pMem->z==0 );
+
+  assert( pMem->szMalloc==0
+       || pMem->szMalloc==sqlite3DbMallocSize(pMem->db, pMem->zMalloc) );
+  if( pMem->szMalloc<n ){
+    if( n<32 ) n = 32;
+    if( bPreserve && pMem->szMalloc>0 && pMem->z==pMem->zMalloc ){
       pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
-      preserve = 0;
+      bPreserve = 0;
     }else{
-      sqlite3DbFree(pMem->db, pMem->zMalloc);
+      if( pMem->szMalloc>0 ) sqlite3DbFree(pMem->db, pMem->zMalloc);
       pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
     }
+    if( pMem->zMalloc==0 ){
+      sqlite3VdbeMemSetNull(pMem);
+      pMem->z = 0;
+      pMem->szMalloc = 0;
+      return SQLITE_NOMEM_BKPT;
+    }else{
+      pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
+    }
   }
 
-  if( pMem->z && preserve && pMem->zMalloc && pMem->z!=pMem->zMalloc ){
+  if( bPreserve && pMem->z && pMem->z!=pMem->zMalloc ){
     memcpy(pMem->zMalloc, pMem->z, pMem->n);
   }
-  if( pMem->flags&MEM_Dyn && pMem->xDel ){
+  if( (pMem->flags&MEM_Dyn)!=0 ){
+    assert( pMem->xDel!=0 && pMem->xDel!=SQLITE_DYNAMIC );
     pMem->xDel((void *)(pMem->z));
   }
 
   pMem->z = pMem->zMalloc;
-  if( pMem->z==0 ){
-    pMem->flags = MEM_Null;
-  }else{
-    pMem->flags &= ~(MEM_Ephem|MEM_Static);
+  pMem->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Static);
+  return SQLITE_OK;
+}
+
+/*
+** Change the pMem->zMalloc allocation to be at least szNew bytes.
+** If pMem->zMalloc already meets or exceeds the requested size, this
+** routine is a no-op.
+**
+** Any prior string or blob content in the pMem object may be discarded.
+** The pMem->xDel destructor is called, if it exists.  Though MEM_Str
+** and MEM_Blob values may be discarded, MEM_Int, MEM_Real, and MEM_Null
+** values are preserved.
+**
+** Return SQLITE_OK on success or an error code (probably SQLITE_NOMEM)
+** if unable to complete the resizing.
+*/
+SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){
+  assert( szNew>0 );
+  assert( (pMem->flags & MEM_Dyn)==0 || pMem->szMalloc==0 );
+  if( pMem->szMalloc<szNew ){
+    return sqlite3VdbeMemGrow(pMem, szNew, 0);
   }
-  pMem->xDel = 0;
-  return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
+  assert( (pMem->flags & MEM_Dyn)==0 );
+  pMem->z = pMem->zMalloc;
+  pMem->flags &= (MEM_Null|MEM_Int|MEM_Real);
+  return SQLITE_OK;
 }
 
 /*
-** Make the given Mem object MEM_Dyn.  In other words, make it so
-** that any TEXT or BLOB content is stored in memory obtained from
-** malloc().  In this way, we know that the memory is safe to be
-** overwritten or altered.
+** Change pMem so that its MEM_Str or MEM_Blob value is stored in
+** MEM.zMalloc, where it can be safely written.
 **
 ** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
 */
@@ -57144,19 +68843,20 @@ SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem *pMem){
   int f;
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( (pMem->flags&MEM_RowSet)==0 );
-  expandBlob(pMem);
+  ExpandBlob(pMem);
   f = pMem->flags;
-  if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
+  if( (f&(MEM_Str|MEM_Blob)) && (pMem->szMalloc==0 || pMem->z!=pMem->zMalloc) ){
     if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     pMem->z[pMem->n] = 0;
     pMem->z[pMem->n+1] = 0;
     pMem->flags |= MEM_Term;
+  }
+  pMem->flags &= ~MEM_Ephem;
 #ifdef SQLITE_DEBUG
-    pMem->pScopyFrom = 0;
+  pMem->pScopyFrom = 0;
 #endif
-  }
 
   return SQLITE_OK;
 }
@@ -57179,7 +68879,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){
       nByte = 1;
     }
     if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
 
     memset(&pMem->z[pMem->n], 0, pMem->u.nZero);
@@ -57190,17 +68890,13 @@ SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){
 }
 #endif
 
-
 /*
-** Make sure the given Mem is \u0000 terminated.
+** It is already known that pMem contains an unterminated string.
+** Add the zero terminator.
 */
-SQLITE_PRIVATE int sqlite3VdbeMemNulTerminate(Mem *pMem){
-  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
-  if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
-    return SQLITE_OK;   /* Nothing to do */
-  }
+static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){
   if( sqlite3VdbeMemGrow(pMem, pMem->n+2, 1) ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pMem->z[pMem->n] = 0;
   pMem->z[pMem->n+1] = 0;
@@ -57209,20 +68905,34 @@ SQLITE_PRIVATE int sqlite3VdbeMemNulTerminate(Mem *pMem){
 }
 
 /*
+** Make sure the given Mem is \u0000 terminated.
+*/
+SQLITE_PRIVATE int sqlite3VdbeMemNulTerminate(Mem *pMem){
+  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  testcase( (pMem->flags & (MEM_Term|MEM_Str))==(MEM_Term|MEM_Str) );
+  testcase( (pMem->flags & (MEM_Term|MEM_Str))==0 );
+  if( (pMem->flags & (MEM_Term|MEM_Str))!=MEM_Str ){
+    return SQLITE_OK;   /* Nothing to do */
+  }else{
+    return vdbeMemAddTerminator(pMem);
+  }
+}
+
+/*
 ** Add MEM_Str to the set of representations for the given Mem.  Numbers
 ** are converted using sqlite3_snprintf().  Converting a BLOB to a string
 ** is a no-op.
 **
-** Existing representations MEM_Int and MEM_Real are *not* invalidated.
+** Existing representations MEM_Int and MEM_Real are invalidated if
+** bForce is true but are retained if bForce is false.
 **
 ** A MEM_Null value will never be passed to this function. This function is
 ** used for converting values to text for returning to the user (i.e. via
 ** sqlite3_value_text()), or for ensuring that values to be used as btree
 ** keys are strings. In the former case a NULL pointer is returned the
-** user and the later is an internal programming error.
+** user and the latter is an internal programming error.
 */
-SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, int enc){
-  int rc = SQLITE_OK;
+SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){
   int fg = pMem->flags;
   const int nByte = 32;
 
@@ -57234,11 +68944,11 @@ SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, int enc){
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
 
-  if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
-    return SQLITE_NOMEM;
+  if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
+    return SQLITE_NOMEM_BKPT;
   }
 
-  /* For a Real or Integer, use sqlite3_mprintf() to produce the UTF-8
+  /* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
   ** string representation of the value. Then, if the required encoding
   ** is UTF-16le or UTF-16be do a translation.
   ** 
@@ -57248,13 +68958,14 @@ SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, int enc){
     sqlite3_snprintf(nByte, pMem->z, "%lld", pMem->u.i);
   }else{
     assert( fg & MEM_Real );
-    sqlite3_snprintf(nByte, pMem->z, "%!.15g", pMem->r);
+    sqlite3_snprintf(nByte, pMem->z, "%!.15g", pMem->u.r);
   }
   pMem->n = sqlite3Strlen30(pMem->z);
   pMem->enc = SQLITE_UTF8;
   pMem->flags |= MEM_Str|MEM_Term;
+  if( bForce ) pMem->flags &= ~(MEM_Int|MEM_Real);
   sqlite3VdbeChangeEncoding(pMem, enc);
-  return rc;
+  return SQLITE_OK;
 }
 
 /*
@@ -57269,68 +68980,96 @@ SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
   int rc = SQLITE_OK;
   if( ALWAYS(pFunc && pFunc->xFinalize) ){
     sqlite3_context ctx;
+    Mem t;
     assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
     assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
     memset(&ctx, 0, sizeof(ctx));
-    ctx.s.flags = MEM_Null;
-    ctx.s.db = pMem->db;
+    memset(&t, 0, sizeof(t));
+    t.flags = MEM_Null;
+    t.db = pMem->db;
+    ctx.pOut = &t;
     ctx.pMem = pMem;
     ctx.pFunc = pFunc;
     pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
-    assert( 0==(pMem->flags&MEM_Dyn) && !pMem->xDel );
-    sqlite3DbFree(pMem->db, pMem->zMalloc);
-    memcpy(pMem, &ctx.s, sizeof(ctx.s));
+    assert( (pMem->flags & MEM_Dyn)==0 );
+    if( pMem->szMalloc>0 ) sqlite3DbFree(pMem->db, pMem->zMalloc);
+    memcpy(pMem, &t, sizeof(t));
     rc = ctx.isError;
   }
   return rc;
 }
 
 /*
-** If the memory cell contains a string value that must be freed by
-** invoking an external callback, free it now. Calling this function
-** does not free any Mem.zMalloc buffer.
+** If the memory cell contains a value that must be freed by
+** invoking the external callback in Mem.xDel, then this routine
+** will free that value.  It also sets Mem.flags to MEM_Null.
+**
+** This is a helper routine for sqlite3VdbeMemSetNull() and
+** for sqlite3VdbeMemRelease().  Use those other routines as the
+** entry point for releasing Mem resources.
 */
-SQLITE_PRIVATE void sqlite3VdbeMemReleaseExternal(Mem *p){
+static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){
   assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
+  assert( VdbeMemDynamic(p) );
   if( p->flags&MEM_Agg ){
     sqlite3VdbeMemFinalize(p, p->u.pDef);
     assert( (p->flags & MEM_Agg)==0 );
-    sqlite3VdbeMemRelease(p);
-  }else if( p->flags&MEM_Dyn && p->xDel ){
+    testcase( p->flags & MEM_Dyn );
+  }
+  if( p->flags&MEM_Dyn ){
     assert( (p->flags&MEM_RowSet)==0 );
+    assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
     p->xDel((void *)p->z);
-    p->xDel = 0;
   }else if( p->flags&MEM_RowSet ){
     sqlite3RowSetClear(p->u.pRowSet);
   }else if( p->flags&MEM_Frame ){
-    sqlite3VdbeMemSetNull(p);
+    VdbeFrame *pFrame = p->u.pFrame;
+    pFrame->pParent = pFrame->v->pDelFrame;
+    pFrame->v->pDelFrame = pFrame;
   }
+  p->flags = MEM_Null;
 }
 
 /*
-** Release any memory held by the Mem. This may leave the Mem in an
-** inconsistent state, for example with (Mem.z==0) and
-** (Mem.type==SQLITE_TEXT).
+** Release memory held by the Mem p, both external memory cleared
+** by p->xDel and memory in p->zMalloc.
+**
+** This is a helper routine invoked by sqlite3VdbeMemRelease() in
+** the unusual case where there really is memory in p that needs
+** to be freed.
 */
-SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){
-  MemReleaseExt(p);
-  sqlite3DbFree(p->db, p->zMalloc);
+static SQLITE_NOINLINE void vdbeMemClear(Mem *p){
+  if( VdbeMemDynamic(p) ){
+    vdbeMemClearExternAndSetNull(p);
+  }
+  if( p->szMalloc ){
+    sqlite3DbFree(p->db, p->zMalloc);
+    p->szMalloc = 0;
+  }
   p->z = 0;
-  p->zMalloc = 0;
-  p->xDel = 0;
 }
 
 /*
-** Convert a 64-bit IEEE double into a 64-bit signed integer.
-** If the double is too large, return 0x8000000000000000.
+** Release any memory resources held by the Mem.  Both the memory that is
+** free by Mem.xDel and the Mem.zMalloc allocation are freed.
 **
-** Most systems appear to do this simply by assigning
-** variables and without the extra range tests.  But
-** there are reports that windows throws an expection
-** if the floating point value is out of range. (See ticket #2880.)
-** Because we do not completely understand the problem, we will
-** take the conservative approach and always do range tests
-** before attempting the conversion.
+** Use this routine prior to clean up prior to abandoning a Mem, or to
+** reset a Mem back to its minimum memory utilization.
+**
+** Use sqlite3VdbeMemSetNull() to release just the Mem.xDel space
+** prior to inserting new content into the Mem.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){
+  assert( sqlite3VdbeCheckMemInvariants(p) );
+  if( VdbeMemDynamic(p) || p->szMalloc ){
+    vdbeMemClear(p);
+  }
+}
+
+/*
+** Convert a 64-bit IEEE double into a 64-bit signed integer.
+** If the double is out of range of a 64-bit signed integer then
+** return the closest available 64-bit signed integer.
 */
 static i64 doubleToInt64(double r){
 #ifdef SQLITE_OMIT_FLOATING_POINT
@@ -57347,14 +69086,10 @@ static i64 doubleToInt64(double r){
   static const i64 maxInt = LARGEST_INT64;
   static const i64 minInt = SMALLEST_INT64;
 
-  if( r<(double)minInt ){
-    return minInt;
-  }else if( r>(double)maxInt ){
-    /* minInt is correct here - not maxInt.  It turns out that assigning
-    ** a very large positive number to an integer results in a very large
-    ** negative integer.  This makes no sense, but it is what x86 hardware
-    ** does so for compatibility we will do the same in software. */
+  if( r<=(double)minInt ){
     return minInt;
+  }else if( r>=(double)maxInt ){
+    return maxInt;
   }else{
     return (i64)r;
   }
@@ -57367,7 +69102,7 @@ static i64 doubleToInt64(double r){
 ** If pMem is an integer, then the value is exact.  If pMem is
 ** a floating-point then the value returned is the integer part.
 ** If pMem is a string or blob, then we make an attempt to convert
-** it into a integer and return that.  If pMem represents an
+** it into an integer and return that.  If pMem represents an
 ** an SQL-NULL value, return 0.
 **
 ** If pMem represents a string value, its encoding might be changed.
@@ -57380,11 +69115,10 @@ SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem *pMem){
   if( flags & MEM_Int ){
     return pMem->u.i;
   }else if( flags & MEM_Real ){
-    return doubleToInt64(pMem->r);
+    return doubleToInt64(pMem->u.r);
   }else if( flags & (MEM_Str|MEM_Blob) ){
     i64 value = 0;
     assert( pMem->z || pMem->n==0 );
-    testcase( pMem->z==0 );
     sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);
     return value;
   }else{
@@ -57402,7 +69136,7 @@ SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
   if( pMem->flags & MEM_Real ){
-    return pMem->r;
+    return pMem->u.r;
   }else if( pMem->flags & MEM_Int ){
     return (double)pMem->u.i;
   }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
@@ -57421,12 +69155,13 @@ SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem *pMem){
 ** MEM_Int if we can.
 */
 SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem *pMem){
+  i64 ix;
   assert( pMem->flags & MEM_Real );
   assert( (pMem->flags & MEM_RowSet)==0 );
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
-  pMem->u.i = doubleToInt64(pMem->r);
+  ix = doubleToInt64(pMem->u.r);
 
   /* Only mark the value as an integer if
   **
@@ -57436,13 +69171,11 @@ SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem *pMem){
   **
   ** The second and third terms in the following conditional enforces
   ** the second condition under the assumption that addition overflow causes
-  ** values to wrap around.  On x86 hardware, the third term is always
-  ** true and could be omitted.  But we leave it in because other
-  ** architectures might behave differently.
+  ** values to wrap around.
   */
-  if( pMem->r==(double)pMem->u.i && pMem->u.i>SMALLEST_INT64
-      && ALWAYS(pMem->u.i<LARGEST_INT64) ){
-    pMem->flags |= MEM_Int;
+  if( pMem->u.r==ix && ix>SMALLEST_INT64 && ix<LARGEST_INT64 ){
+    pMem->u.i = ix;
+    MemSetTypeFlag(pMem, MEM_Int);
   }
 }
 
@@ -57467,7 +69200,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
-  pMem->r = sqlite3VdbeRealValue(pMem);
+  pMem->u.r = sqlite3VdbeRealValue(pMem);
   MemSetTypeFlag(pMem, MEM_Real);
   return SQLITE_OK;
 }
@@ -57487,7 +69220,7 @@ SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem *pMem){
     if( 0==sqlite3Atoi64(pMem->z, &pMem->u.i, pMem->n, pMem->enc) ){
       MemSetTypeFlag(pMem, MEM_Int);
     }else{
-      pMem->r = sqlite3VdbeRealValue(pMem);
+      pMem->u.r = sqlite3VdbeRealValue(pMem);
       MemSetTypeFlag(pMem, MEM_Real);
       sqlite3VdbeIntegerAffinity(pMem);
     }
@@ -57498,19 +69231,83 @@ SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem *pMem){
 }
 
 /*
+** Cast the datatype of the value in pMem according to the affinity
+** "aff".  Casting is different from applying affinity in that a cast
+** is forced.  In other words, the value is converted into the desired
+** affinity even if that results in loss of data.  This routine is
+** used (for example) to implement the SQL "cast()" operator.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem *pMem, u8 aff, u8 encoding){
+  if( pMem->flags & MEM_Null ) return;
+  switch( aff ){
+    case SQLITE_AFF_BLOB: {   /* Really a cast to BLOB */
+      if( (pMem->flags & MEM_Blob)==0 ){
+        sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);
+        assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );
+        MemSetTypeFlag(pMem, MEM_Blob);
+      }else{
+        pMem->flags &= ~(MEM_TypeMask&~MEM_Blob);
+      }
+      break;
+    }
+    case SQLITE_AFF_NUMERIC: {
+      sqlite3VdbeMemNumerify(pMem);
+      break;
+    }
+    case SQLITE_AFF_INTEGER: {
+      sqlite3VdbeMemIntegerify(pMem);
+      break;
+    }
+    case SQLITE_AFF_REAL: {
+      sqlite3VdbeMemRealify(pMem);
+      break;
+    }
+    default: {
+      assert( aff==SQLITE_AFF_TEXT );
+      assert( MEM_Str==(MEM_Blob>>3) );
+      pMem->flags |= (pMem->flags&MEM_Blob)>>3;
+      sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);
+      assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );
+      pMem->flags &= ~(MEM_Int|MEM_Real|MEM_Blob|MEM_Zero);
+      break;
+    }
+  }
+}
+
+/*
+** Initialize bulk memory to be a consistent Mem object.
+**
+** The minimum amount of initialization feasible is performed.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem *pMem, sqlite3 *db, u16 flags){
+  assert( (flags & ~MEM_TypeMask)==0 );
+  pMem->flags = flags;
+  pMem->db = db;
+  pMem->szMalloc = 0;
+}
+
+
+/*
 ** Delete any previous value and set the value stored in *pMem to NULL.
+**
+** This routine calls the Mem.xDel destructor to dispose of values that
+** require the destructor.  But it preserves the Mem.zMalloc memory allocation.
+** To free all resources, use sqlite3VdbeMemRelease(), which both calls this
+** routine to invoke the destructor and deallocates Mem.zMalloc.
+**
+** Use this routine to reset the Mem prior to insert a new value.
+**
+** Use sqlite3VdbeMemRelease() to complete erase the Mem prior to abandoning it.
 */
 SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem *pMem){
-  if( pMem->flags & MEM_Frame ){
-    VdbeFrame *pFrame = pMem->u.pFrame;
-    pFrame->pParent = pFrame->v->pDelFrame;
-    pFrame->v->pDelFrame = pFrame;
-  }
-  if( pMem->flags & MEM_RowSet ){
-    sqlite3RowSetClear(pMem->u.pRowSet);
+  if( VdbeMemDynamic(pMem) ){
+    vdbeMemClearExternAndSetNull(pMem);
+  }else{
+    pMem->flags = MEM_Null;
   }
-  MemSetTypeFlag(pMem, MEM_Null);
-  pMem->type = SQLITE_NULL;
+}
+SQLITE_PRIVATE void sqlite3ValueSetNull(sqlite3_value *p){
+  sqlite3VdbeMemSetNull((Mem*)p); 
 }
 
 /*
@@ -57520,19 +69317,22 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem *pMem){
 SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
   sqlite3VdbeMemRelease(pMem);
   pMem->flags = MEM_Blob|MEM_Zero;
-  pMem->type = SQLITE_BLOB;
   pMem->n = 0;
   if( n<0 ) n = 0;
   pMem->u.nZero = n;
   pMem->enc = SQLITE_UTF8;
+  pMem->z = 0;
+}
 
-#ifdef SQLITE_OMIT_INCRBLOB
-  sqlite3VdbeMemGrow(pMem, n, 0);
-  if( pMem->z ){
-    pMem->n = n;
-    memset(pMem->z, 0, n);
-  }
-#endif
+/*
+** The pMem is known to contain content that needs to be destroyed prior
+** to a value change.  So invoke the destructor, then set the value to
+** a 64-bit integer.
+*/
+static SQLITE_NOINLINE void vdbeReleaseAndSetInt64(Mem *pMem, i64 val){
+  sqlite3VdbeMemSetNull(pMem);
+  pMem->u.i = val;
+  pMem->flags = MEM_Int;
 }
 
 /*
@@ -57540,10 +69340,12 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
 ** manifest type INTEGER.
 */
 SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
-  sqlite3VdbeMemRelease(pMem);
-  pMem->u.i = val;
-  pMem->flags = MEM_Int;
-  pMem->type = SQLITE_INTEGER;
+  if( VdbeMemDynamic(pMem) ){
+    vdbeReleaseAndSetInt64(pMem, val);
+  }else{
+    pMem->u.i = val;
+    pMem->flags = MEM_Int;
+  }
 }
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
@@ -57552,13 +69354,10 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
 ** manifest type REAL.
 */
 SQLITE_PRIVATE void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
-  if( sqlite3IsNaN(val) ){
-    sqlite3VdbeMemSetNull(pMem);
-  }else{
-    sqlite3VdbeMemRelease(pMem);
-    pMem->r = val;
+  sqlite3VdbeMemSetNull(pMem);
+  if( !sqlite3IsNaN(val) ){
+    pMem->u.r = val;
     pMem->flags = MEM_Real;
-    pMem->type = SQLITE_FLOAT;
   }
 }
 #endif
@@ -57572,13 +69371,14 @@ SQLITE_PRIVATE void sqlite3VdbeMemSetRowSet(Mem *pMem){
   assert( db!=0 );
   assert( (pMem->flags & MEM_RowSet)==0 );
   sqlite3VdbeMemRelease(pMem);
-  pMem->zMalloc = sqlite3DbMallocRaw(db, 64);
+  pMem->zMalloc = sqlite3DbMallocRawNN(db, 64);
   if( db->mallocFailed ){
     pMem->flags = MEM_Null;
+    pMem->szMalloc = 0;
   }else{
     assert( pMem->zMalloc );
-    pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc, 
-                                       sqlite3DbMallocSize(db, pMem->zMalloc));
+    pMem->szMalloc = sqlite3DbMallocSize(db, pMem->zMalloc);
+    pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc, pMem->szMalloc);
     assert( pMem->u.pRowSet!=0 );
     pMem->flags = MEM_RowSet;
   }
@@ -57602,19 +69402,19 @@ SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem *p){
 
 #ifdef SQLITE_DEBUG
 /*
-** This routine prepares a memory cell for modication by breaking
+** This routine prepares a memory cell for modification by breaking
 ** its link to a shallow copy and by marking any current shallow
 ** copies of this cell as invalid.
 **
 ** This is used for testing and debugging only - to make sure shallow
 ** copies are not misused.
 */
-SQLITE_PRIVATE void sqlite3VdbeMemPrepareToChange(Vdbe *pVdbe, Mem *pMem){
+SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
   int i;
   Mem *pX;
-  for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){
+  for(i=0, pX=pVdbe->aMem; i<pVdbe->nMem; i++, pX++){
     if( pX->pScopyFrom==pMem ){
-      pX->flags |= MEM_Invalid;
+      pX->flags |= MEM_Undefined;
       pX->pScopyFrom = 0;
     }
   }
@@ -57622,10 +69422,6 @@ SQLITE_PRIVATE void sqlite3VdbeMemPrepareToChange(Vdbe *pVdbe, Mem *pMem){
 }
 #endif /* SQLITE_DEBUG */
 
-/*
-** Size of struct Mem not including the Mem.zMalloc member.
-*/
-#define MEMCELLSIZE (size_t)(&(((Mem *)0)->zMalloc))
 
 /*
 ** Make an shallow copy of pFrom into pTo.  Prior contents of
@@ -57633,11 +69429,16 @@ SQLITE_PRIVATE void sqlite3VdbeMemPrepareToChange(Vdbe *pVdbe, Mem *pMem){
 ** pFrom->z is used, then pTo->z points to the same thing as pFrom->z
 ** and flags gets srcType (either MEM_Ephem or MEM_Static).
 */
+static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
+  vdbeMemClearExternAndSetNull(pTo);
+  assert( !VdbeMemDynamic(pTo) );
+  sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
+}
 SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
   assert( (pFrom->flags & MEM_RowSet)==0 );
-  MemReleaseExt(pTo);
+  assert( pTo->db==pFrom->db );
+  if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
   memcpy(pTo, pFrom, MEMCELLSIZE);
-  pTo->xDel = 0;
   if( (pFrom->flags&MEM_Static)==0 ){
     pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
     assert( srcType==MEM_Ephem || srcType==MEM_Static );
@@ -57653,10 +69454,9 @@ SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
 
   assert( (pFrom->flags & MEM_RowSet)==0 );
-  MemReleaseExt(pTo);
+  if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);
   pTo->flags &= ~MEM_Dyn;
-
   if( pTo->flags&(MEM_Str|MEM_Blob) ){
     if( 0==(pFrom->flags&MEM_Static) ){
       pTo->flags |= MEM_Ephem;
@@ -57681,8 +69481,7 @@ SQLITE_PRIVATE void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){
   sqlite3VdbeMemRelease(pTo);
   memcpy(pTo, pFrom, sizeof(Mem));
   pFrom->flags = MEM_Null;
-  pFrom->xDel = 0;
-  pFrom->zMalloc = 0;
+  pFrom->szMalloc = 0;
 }
 
 /*
@@ -57729,7 +69528,8 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
   if( nByte<0 ){
     assert( enc!=0 );
     if( enc==SQLITE_UTF8 ){
-      for(nByte=0; nByte<=iLimit && z[nByte]; nByte++){}
+      nByte = sqlite3Strlen30(z);
+      if( nByte>iLimit ) nByte = iLimit+1;
     }else{
       for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}
     }
@@ -57748,14 +69548,17 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
     if( nByte>iLimit ){
       return SQLITE_TOOBIG;
     }
-    if( sqlite3VdbeMemGrow(pMem, nAlloc, 0) ){
-      return SQLITE_NOMEM;
+    testcase( nAlloc==0 );
+    testcase( nAlloc==31 );
+    testcase( nAlloc==32 );
+    if( sqlite3VdbeMemClearAndResize(pMem, MAX(nAlloc,32)) ){
+      return SQLITE_NOMEM_BKPT;
     }
     memcpy(pMem->z, z, nAlloc);
   }else if( xDel==SQLITE_DYNAMIC ){
     sqlite3VdbeMemRelease(pMem);
     pMem->zMalloc = pMem->z = (char *)z;
-    pMem->xDel = 0;
+    pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
   }else{
     sqlite3VdbeMemRelease(pMem);
     pMem->z = (char *)z;
@@ -57766,11 +69569,10 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
   pMem->n = nByte;
   pMem->flags = flags;
   pMem->enc = (enc==0 ? SQLITE_UTF8 : enc);
-  pMem->type = (enc==0 ? SQLITE_BLOB : SQLITE_TEXT);
 
 #ifndef SQLITE_OMIT_UTF16
   if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 #endif
 
@@ -57782,218 +69584,106 @@ SQLITE_PRIVATE int sqlite3VdbeMemSetStr(
 }
 
 /*
-** Compare the values contained by the two memory cells, returning
-** negative, zero or positive if pMem1 is less than, equal to, or greater
-** than pMem2. Sorting order is NULL's first, followed by numbers (integers
-** and reals) sorted numerically, followed by text ordered by the collating
-** sequence pColl and finally blob's ordered by memcmp().
-**
-** Two NULL values are considered equal by this function.
-*/
-SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
-  int rc;
-  int f1, f2;
-  int combined_flags;
-
-  f1 = pMem1->flags;
-  f2 = pMem2->flags;
-  combined_flags = f1|f2;
-  assert( (combined_flags & MEM_RowSet)==0 );
- 
-  /* If one value is NULL, it is less than the other. If both values
-  ** are NULL, return 0.
-  */
-  if( combined_flags&MEM_Null ){
-    return (f2&MEM_Null) - (f1&MEM_Null);
-  }
-
-  /* If one value is a number and the other is not, the number is less.
-  ** If both are numbers, compare as reals if one is a real, or as integers
-  ** if both values are integers.
-  */
-  if( combined_flags&(MEM_Int|MEM_Real) ){
-    if( !(f1&(MEM_Int|MEM_Real)) ){
-      return 1;
-    }
-    if( !(f2&(MEM_Int|MEM_Real)) ){
-      return -1;
-    }
-    if( (f1 & f2 & MEM_Int)==0 ){
-      double r1, r2;
-      if( (f1&MEM_Real)==0 ){
-        r1 = (double)pMem1->u.i;
-      }else{
-        r1 = pMem1->r;
-      }
-      if( (f2&MEM_Real)==0 ){
-        r2 = (double)pMem2->u.i;
-      }else{
-        r2 = pMem2->r;
-      }
-      if( r1<r2 ) return -1;
-      if( r1>r2 ) return 1;
-      return 0;
-    }else{
-      assert( f1&MEM_Int );
-      assert( f2&MEM_Int );
-      if( pMem1->u.i < pMem2->u.i ) return -1;
-      if( pMem1->u.i > pMem2->u.i ) return 1;
-      return 0;
-    }
-  }
-
-  /* If one value is a string and the other is a blob, the string is less.
-  ** If both are strings, compare using the collating functions.
-  */
-  if( combined_flags&MEM_Str ){
-    if( (f1 & MEM_Str)==0 ){
-      return 1;
-    }
-    if( (f2 & MEM_Str)==0 ){
-      return -1;
-    }
-
-    assert( pMem1->enc==pMem2->enc );
-    assert( pMem1->enc==SQLITE_UTF8 || 
-            pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
-
-    /* The collation sequence must be defined at this point, even if
-    ** the user deletes the collation sequence after the vdbe program is
-    ** compiled (this was not always the case).
-    */
-    assert( !pColl || pColl->xCmp );
-
-    if( pColl ){
-      if( pMem1->enc==pColl->enc ){
-        /* The strings are already in the correct encoding.  Call the
-        ** comparison function directly */
-        return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
-      }else{
-        const void *v1, *v2;
-        int n1, n2;
-        Mem c1;
-        Mem c2;
-        memset(&c1, 0, sizeof(c1));
-        memset(&c2, 0, sizeof(c2));
-        sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
-        sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
-        v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
-        n1 = v1==0 ? 0 : c1.n;
-        v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
-        n2 = v2==0 ? 0 : c2.n;
-        rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
-        sqlite3VdbeMemRelease(&c1);
-        sqlite3VdbeMemRelease(&c2);
-        return rc;
-      }
-    }
-    /* If a NULL pointer was passed as the collate function, fall through
-    ** to the blob case and use memcmp().  */
-  }
- 
-  /* Both values must be blobs.  Compare using memcmp().  */
-  rc = memcmp(pMem1->z, pMem2->z, (pMem1->n>pMem2->n)?pMem2->n:pMem1->n);
-  if( rc==0 ){
-    rc = pMem1->n - pMem2->n;
-  }
-  return rc;
-}
-
-/*
 ** Move data out of a btree key or data field and into a Mem structure.
 ** The data or key is taken from the entry that pCur is currently pointing
 ** to.  offset and amt determine what portion of the data or key to retrieve.
 ** key is true to get the key or false to get data.  The result is written
 ** into the pMem element.
 **
-** The pMem structure is assumed to be uninitialized.  Any prior content
-** is overwritten without being freed.
+** The pMem object must have been initialized.  This routine will use
+** pMem->zMalloc to hold the content from the btree, if possible.  New
+** pMem->zMalloc space will be allocated if necessary.  The calling routine
+** is responsible for making sure that the pMem object is eventually
+** destroyed.
 **
 ** If this routine fails for any reason (malloc returns NULL or unable
 ** to read from the disk) then the pMem is left in an inconsistent state.
 */
+static SQLITE_NOINLINE int vdbeMemFromBtreeResize(
+  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
+  u32 offset,       /* Offset from the start of data to return bytes from. */
+  u32 amt,          /* Number of bytes to return. */
+  int key,          /* If true, retrieve from the btree key, not data. */
+  Mem *pMem         /* OUT: Return data in this Mem structure. */
+){
+  int rc;
+  pMem->flags = MEM_Null;
+  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
+    if( key ){
+      rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
+    }else{
+      rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
+    }
+    if( rc==SQLITE_OK ){
+      pMem->z[amt] = 0;
+      pMem->z[amt+1] = 0;
+      pMem->flags = MEM_Blob|MEM_Term;
+      pMem->n = (int)amt;
+    }else{
+      sqlite3VdbeMemRelease(pMem);
+    }
+  }
+  return rc;
+}
 SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(
   BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
-  int offset,       /* Offset from the start of data to return bytes from. */
-  int amt,          /* Number of bytes to return. */
+  u32 offset,       /* Offset from the start of data to return bytes from. */
+  u32 amt,          /* Number of bytes to return. */
   int key,          /* If true, retrieve from the btree key, not data. */
   Mem *pMem         /* OUT: Return data in this Mem structure. */
 ){
   char *zData;        /* Data from the btree layer */
-  int available = 0;  /* Number of bytes available on the local btree page */
+  u32 available = 0;  /* Number of bytes available on the local btree page */
   int rc = SQLITE_OK; /* Return code */
 
   assert( sqlite3BtreeCursorIsValid(pCur) );
+  assert( !VdbeMemDynamic(pMem) );
 
   /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() 
   ** that both the BtShared and database handle mutexes are held. */
   assert( (pMem->flags & MEM_RowSet)==0 );
-  if( key ){
-    zData = (char *)sqlite3BtreeKeyFetch(pCur, &available);
-  }else{
-    zData = (char *)sqlite3BtreeDataFetch(pCur, &available);
-  }
+  zData = (char *)sqlite3BtreePayloadFetch(pCur, &available);
   assert( zData!=0 );
 
-  if( offset+amt<=available && (pMem->flags&MEM_Dyn)==0 ){
-    sqlite3VdbeMemRelease(pMem);
+  if( offset+amt<=available ){
     pMem->z = &zData[offset];
     pMem->flags = MEM_Blob|MEM_Ephem;
-  }else if( SQLITE_OK==(rc = sqlite3VdbeMemGrow(pMem, amt+2, 0)) ){
-    pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
-    pMem->enc = 0;
-    pMem->type = SQLITE_BLOB;
-    if( key ){
-      rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
-    }else{
-      rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
-    }
-    pMem->z[amt] = 0;
-    pMem->z[amt+1] = 0;
-    if( rc!=SQLITE_OK ){
-      sqlite3VdbeMemRelease(pMem);
-    }
+    pMem->n = (int)amt;
+  }else{
+    rc = vdbeMemFromBtreeResize(pCur, offset, amt, key, pMem);
   }
-  pMem->n = amt;
 
   return rc;
 }
 
-/* This function is only available internally, it is not part of the
-** external API. It works in a similar way to sqlite3_value_text(),
-** except the data returned is in the encoding specified by the second
-** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
-** SQLITE_UTF8.
-**
-** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
-** If that is the case, then the result must be aligned on an even byte
-** boundary.
+/*
+** The pVal argument is known to be a value other than NULL.
+** Convert it into a string with encoding enc and return a pointer
+** to a zero-terminated version of that string.
 */
-SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
-  if( !pVal ) return 0;
-
+static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
+  assert( pVal!=0 );
   assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
   assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
   assert( (pVal->flags & MEM_RowSet)==0 );
-
-  if( pVal->flags&MEM_Null ){
-    return 0;
-  }
-  assert( (MEM_Blob>>3) == MEM_Str );
-  pVal->flags |= (pVal->flags & MEM_Blob)>>3;
-  expandBlob(pVal);
-  if( pVal->flags&MEM_Str ){
-    sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
+  assert( (pVal->flags & (MEM_Null))==0 );
+  if( pVal->flags & (MEM_Blob|MEM_Str) ){
+    pVal->flags |= MEM_Str;
+    if( pVal->flags & MEM_Zero ){
+      sqlite3VdbeMemExpandBlob(pVal);
+    }
+    if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){
+      sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
+    }
     if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){
       assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );
       if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){
         return 0;
       }
     }
-    sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-59893-45467 */
+    sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */
   }else{
-    assert( (pVal->flags&MEM_Blob)==0 );
-    sqlite3VdbeMemStringify(pVal, enc);
+    sqlite3VdbeMemStringify(pVal, enc, 0);
     assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) );
   }
   assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0
@@ -58005,6 +69695,30 @@ SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
   }
 }
 
+/* This function is only available internally, it is not part of the
+** external API. It works in a similar way to sqlite3_value_text(),
+** except the data returned is in the encoding specified by the second
+** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or
+** SQLITE_UTF8.
+**
+** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.
+** If that is the case, then the result must be aligned on an even byte
+** boundary.
+*/
+SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
+  if( !pVal ) return 0;
+  assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
+  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
+  assert( (pVal->flags & MEM_RowSet)==0 );
+  if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){
+    return pVal->z;
+  }
+  if( pVal->flags&MEM_Null ){
+    return 0;
+  }
+  return valueToText(pVal, enc);
+}
+
 /*
 ** Create a new sqlite3_value object.
 */
@@ -58012,50 +69726,227 @@ SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *db){
   Mem *p = sqlite3DbMallocZero(db, sizeof(*p));
   if( p ){
     p->flags = MEM_Null;
-    p->type = SQLITE_NULL;
     p->db = db;
   }
   return p;
 }
 
 /*
-** Create a new sqlite3_value object, containing the value of pExpr.
+** Context object passed by sqlite3Stat4ProbeSetValue() through to 
+** valueNew(). See comments above valueNew() for details.
+*/
+struct ValueNewStat4Ctx {
+  Parse *pParse;
+  Index *pIdx;
+  UnpackedRecord **ppRec;
+  int iVal;
+};
+
+/*
+** Allocate and return a pointer to a new sqlite3_value object. If
+** the second argument to this function is NULL, the object is allocated
+** by calling sqlite3ValueNew().
 **
-** This only works for very simple expressions that consist of one constant
-** token (i.e. "5", "5.1", "'a string'"). If the expression can
-** be converted directly into a value, then the value is allocated and
-** a pointer written to *ppVal. The caller is responsible for deallocating
-** the value by passing it to sqlite3ValueFree() later on. If the expression
-** cannot be converted to a value, then *ppVal is set to NULL.
+** Otherwise, if the second argument is non-zero, then this function is 
+** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not
+** already been allocated, allocate the UnpackedRecord structure that 
+** that function will return to its caller here. Then return a pointer to
+** an sqlite3_value within the UnpackedRecord.a[] array.
 */
-SQLITE_PRIVATE int sqlite3ValueFromExpr(
-  sqlite3 *db,              /* The database connection */
-  Expr *pExpr,              /* The expression to evaluate */
-  u8 enc,                   /* Encoding to use */
-  u8 affinity,              /* Affinity to use */
-  sqlite3_value **ppVal     /* Write the new value here */
+static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( p ){
+    UnpackedRecord *pRec = p->ppRec[0];
+
+    if( pRec==0 ){
+      Index *pIdx = p->pIdx;      /* Index being probed */
+      int nByte;                  /* Bytes of space to allocate */
+      int i;                      /* Counter variable */
+      int nCol = pIdx->nColumn;   /* Number of index columns including rowid */
+  
+      nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));
+      pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);
+      if( pRec ){
+        pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);
+        if( pRec->pKeyInfo ){
+          assert( pRec->pKeyInfo->nField+pRec->pKeyInfo->nXField==nCol );
+          assert( pRec->pKeyInfo->enc==ENC(db) );
+          pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));
+          for(i=0; i<nCol; i++){
+            pRec->aMem[i].flags = MEM_Null;
+            pRec->aMem[i].db = db;
+          }
+        }else{
+          sqlite3DbFree(db, pRec);
+          pRec = 0;
+        }
+      }
+      if( pRec==0 ) return 0;
+      p->ppRec[0] = pRec;
+    }
+  
+    pRec->nField = p->iVal+1;
+    return &pRec->aMem[p->iVal];
+  }
+#else
+  UNUSED_PARAMETER(p);
+#endif /* defined(SQLITE_ENABLE_STAT3_OR_STAT4) */
+  return sqlite3ValueNew(db);
+}
+
+/*
+** The expression object indicated by the second argument is guaranteed
+** to be a scalar SQL function. If
+**
+**   * all function arguments are SQL literals,
+**   * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and
+**   * the SQLITE_FUNC_NEEDCOLL function flag is not set,
+**
+** then this routine attempts to invoke the SQL function. Assuming no
+** error occurs, output parameter (*ppVal) is set to point to a value 
+** object containing the result before returning SQLITE_OK.
+**
+** Affinity aff is applied to the result of the function before returning.
+** If the result is a text value, the sqlite3_value object uses encoding 
+** enc.
+**
+** If the conditions above are not met, this function returns SQLITE_OK
+** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to
+** NULL and an SQLite error code returned.
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static int valueFromFunction(
+  sqlite3 *db,                    /* The database connection */
+  Expr *p,                        /* The expression to evaluate */
+  u8 enc,                         /* Encoding to use */
+  u8 aff,                         /* Affinity to use */
+  sqlite3_value **ppVal,          /* Write the new value here */
+  struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */
+){
+  sqlite3_context ctx;            /* Context object for function invocation */
+  sqlite3_value **apVal = 0;      /* Function arguments */
+  int nVal = 0;                   /* Size of apVal[] array */
+  FuncDef *pFunc = 0;             /* Function definition */
+  sqlite3_value *pVal = 0;        /* New value */
+  int rc = SQLITE_OK;             /* Return code */
+  ExprList *pList = 0;            /* Function arguments */
+  int i;                          /* Iterator variable */
+
+  assert( pCtx!=0 );
+  assert( (p->flags & EP_TokenOnly)==0 );
+  pList = p->x.pList;
+  if( pList ) nVal = pList->nExpr;
+  pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);
+  assert( pFunc );
+  if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0 
+   || (pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)
+  ){
+    return SQLITE_OK;
+  }
+
+  if( pList ){
+    apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal);
+    if( apVal==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+      goto value_from_function_out;
+    }
+    for(i=0; i<nVal; i++){
+      rc = sqlite3ValueFromExpr(db, pList->a[i].pExpr, enc, aff, &apVal[i]);
+      if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out;
+    }
+  }
+
+  pVal = valueNew(db, pCtx);
+  if( pVal==0 ){
+    rc = SQLITE_NOMEM_BKPT;
+    goto value_from_function_out;
+  }
+
+  assert( pCtx->pParse->rc==SQLITE_OK );
+  memset(&ctx, 0, sizeof(ctx));
+  ctx.pOut = pVal;
+  ctx.pFunc = pFunc;
+  pFunc->xSFunc(&ctx, nVal, apVal);
+  if( ctx.isError ){
+    rc = ctx.isError;
+    sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
+  }else{
+    sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
+    assert( rc==SQLITE_OK );
+    rc = sqlite3VdbeChangeEncoding(pVal, enc);
+    if( rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal) ){
+      rc = SQLITE_TOOBIG;
+      pCtx->pParse->nErr++;
+    }
+  }
+  pCtx->pParse->rc = rc;
+
+ value_from_function_out:
+  if( rc!=SQLITE_OK ){
+    pVal = 0;
+  }
+  if( apVal ){
+    for(i=0; i<nVal; i++){
+      sqlite3ValueFree(apVal[i]);
+    }
+    sqlite3DbFree(db, apVal);
+  }
+
+  *ppVal = pVal;
+  return rc;
+}
+#else
+# define valueFromFunction(a,b,c,d,e,f) SQLITE_OK
+#endif /* defined(SQLITE_ENABLE_STAT3_OR_STAT4) */
+
+/*
+** Extract a value from the supplied expression in the manner described
+** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object
+** using valueNew().
+**
+** If pCtx is NULL and an error occurs after the sqlite3_value object
+** has been allocated, it is freed before returning. Or, if pCtx is not
+** NULL, it is assumed that the caller will free any allocated object
+** in all cases.
+*/
+static int valueFromExpr(
+  sqlite3 *db,                    /* The database connection */
+  Expr *pExpr,                    /* The expression to evaluate */
+  u8 enc,                         /* Encoding to use */
+  u8 affinity,                    /* Affinity to use */
+  sqlite3_value **ppVal,          /* Write the new value here */
+  struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */
 ){
   int op;
   char *zVal = 0;
   sqlite3_value *pVal = 0;
   int negInt = 1;
   const char *zNeg = "";
+  int rc = SQLITE_OK;
 
   if( !pExpr ){
     *ppVal = 0;
     return SQLITE_OK;
   }
-  op = pExpr->op;
-
-  /* op can only be TK_REGISTER if we have compiled with SQLITE_ENABLE_STAT3.
-  ** The ifdef here is to enable us to achieve 100% branch test coverage even
-  ** when SQLITE_ENABLE_STAT3 is omitted.
-  */
-#ifdef SQLITE_ENABLE_STAT3
-  if( op==TK_REGISTER ) op = pExpr->op2;
-#else
+  while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;
   if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;
-#endif
+
+  /* Compressed expressions only appear when parsing the DEFAULT clause
+  ** on a table column definition, and hence only when pCtx==0.  This
+  ** check ensures that an EP_TokenOnly expression is never passed down
+  ** into valueFromFunction(). */
+  assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );
+
+  if( op==TK_CAST ){
+    u8 aff = sqlite3AffinityType(pExpr->u.zToken,0);
+    rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);
+    testcase( rc!=SQLITE_OK );
+    if( *ppVal ){
+      sqlite3VdbeMemCast(*ppVal, aff, SQLITE_UTF8);
+      sqlite3ValueApplyAffinity(*ppVal, affinity, SQLITE_UTF8);
+    }
+    return rc;
+  }
 
   /* Handle negative integers in a single step.  This is needed in the
   ** case when the value is -9223372036854775808.
@@ -58069,7 +69960,7 @@ SQLITE_PRIVATE int sqlite3ValueFromExpr(
   }
 
   if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){
-    pVal = sqlite3ValueNew(db);
+    pVal = valueNew(db, pCtx);
     if( pVal==0 ) goto no_mem;
     if( ExprHasProperty(pExpr, EP_IntValue) ){
       sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);
@@ -58077,33 +69968,34 @@ SQLITE_PRIVATE int sqlite3ValueFromExpr(
       zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);
       if( zVal==0 ) goto no_mem;
       sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);
-      if( op==TK_FLOAT ) pVal->type = SQLITE_FLOAT;
     }
-    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_NONE ){
+    if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_BLOB ){
       sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);
     }else{
       sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);
     }
     if( pVal->flags & (MEM_Int|MEM_Real) ) pVal->flags &= ~MEM_Str;
     if( enc!=SQLITE_UTF8 ){
-      sqlite3VdbeChangeEncoding(pVal, enc);
+      rc = sqlite3VdbeChangeEncoding(pVal, enc);
     }
   }else if( op==TK_UMINUS ) {
     /* This branch happens for multiple negative signs.  Ex: -(-5) */
-    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) ){
+    if( SQLITE_OK==sqlite3ValueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal) 
+     && pVal!=0
+    ){
       sqlite3VdbeMemNumerify(pVal);
-      if( pVal->u.i==SMALLEST_INT64 ){
-        pVal->flags &= MEM_Int;
-        pVal->flags |= MEM_Real;
-        pVal->r = (double)LARGEST_INT64;
+      if( pVal->flags & MEM_Real ){
+        pVal->u.r = -pVal->u.r;
+      }else if( pVal->u.i==SMALLEST_INT64 ){
+        pVal->u.r = -(double)SMALLEST_INT64;
+        MemSetTypeFlag(pVal, MEM_Real);
       }else{
         pVal->u.i = -pVal->u.i;
       }
-      pVal->r = -pVal->r;
       sqlite3ValueApplyAffinity(pVal, affinity, enc);
     }
   }else if( op==TK_NULL ){
-    pVal = sqlite3ValueNew(db);
+    pVal = valueNew(db, pCtx);
     if( pVal==0 ) goto no_mem;
   }
 #ifndef SQLITE_OMIT_BLOB_LITERAL
@@ -58111,7 +70003,7 @@ SQLITE_PRIVATE int sqlite3ValueFromExpr(
     int nVal;
     assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
     assert( pExpr->u.zToken[1]=='\'' );
-    pVal = sqlite3ValueNew(db);
+    pVal = valueNew(db, pCtx);
     if( !pVal ) goto no_mem;
     zVal = &pExpr->u.zToken[2];
     nVal = sqlite3Strlen30(zVal)-1;
@@ -58121,21 +70013,301 @@ SQLITE_PRIVATE int sqlite3ValueFromExpr(
   }
 #endif
 
-  if( pVal ){
-    sqlite3VdbeMemStoreType(pVal);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  else if( op==TK_FUNCTION && pCtx!=0 ){
+    rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);
   }
+#endif
+
   *ppVal = pVal;
-  return SQLITE_OK;
+  return rc;
 
 no_mem:
-  db->mallocFailed = 1;
+  sqlite3OomFault(db);
   sqlite3DbFree(db, zVal);
-  sqlite3ValueFree(pVal);
-  *ppVal = 0;
-  return SQLITE_NOMEM;
+  assert( *ppVal==0 );
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pCtx==0 ) sqlite3ValueFree(pVal);
+#else
+  assert( pCtx==0 ); sqlite3ValueFree(pVal);
+#endif
+  return SQLITE_NOMEM_BKPT;
 }
 
 /*
+** Create a new sqlite3_value object, containing the value of pExpr.
+**
+** This only works for very simple expressions that consist of one constant
+** token (i.e. "5", "5.1", "'a string'"). If the expression can
+** be converted directly into a value, then the value is allocated and
+** a pointer written to *ppVal. The caller is responsible for deallocating
+** the value by passing it to sqlite3ValueFree() later on. If the expression
+** cannot be converted to a value, then *ppVal is set to NULL.
+*/
+SQLITE_PRIVATE int sqlite3ValueFromExpr(
+  sqlite3 *db,              /* The database connection */
+  Expr *pExpr,              /* The expression to evaluate */
+  u8 enc,                   /* Encoding to use */
+  u8 affinity,              /* Affinity to use */
+  sqlite3_value **ppVal     /* Write the new value here */
+){
+  return valueFromExpr(db, pExpr, enc, affinity, ppVal, 0);
+}
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** The implementation of the sqlite_record() function. This function accepts
+** a single argument of any type. The return value is a formatted database 
+** record (a blob) containing the argument value.
+**
+** This is used to convert the value stored in the 'sample' column of the
+** sqlite_stat3 table to the record format SQLite uses internally.
+*/
+static void recordFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const int file_format = 1;
+  u32 iSerial;                    /* Serial type */
+  int nSerial;                    /* Bytes of space for iSerial as varint */
+  u32 nVal;                       /* Bytes of space required for argv[0] */
+  int nRet;
+  sqlite3 *db;
+  u8 *aRet;
+
+  UNUSED_PARAMETER( argc );
+  iSerial = sqlite3VdbeSerialType(argv[0], file_format, &nVal);
+  nSerial = sqlite3VarintLen(iSerial);
+  db = sqlite3_context_db_handle(context);
+
+  nRet = 1 + nSerial + nVal;
+  aRet = sqlite3DbMallocRawNN(db, nRet);
+  if( aRet==0 ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    aRet[0] = nSerial+1;
+    putVarint32(&aRet[1], iSerial);
+    sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
+    sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
+    sqlite3DbFree(db, aRet);
+  }
+}
+
+/*
+** Register built-in functions used to help read ANALYZE data.
+*/
+SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void){
+  static FuncDef aAnalyzeTableFuncs[] = {
+    FUNCTION(sqlite_record,   1, 0, 0, recordFunc),
+  };
+  sqlite3InsertBuiltinFuncs(aAnalyzeTableFuncs, ArraySize(aAnalyzeTableFuncs));
+}
+
+/*
+** Attempt to extract a value from pExpr and use it to construct *ppVal.
+**
+** If pAlloc is not NULL, then an UnpackedRecord object is created for
+** pAlloc if one does not exist and the new value is added to the
+** UnpackedRecord object.
+**
+** A value is extracted in the following cases:
+**
+**  * (pExpr==0). In this case the value is assumed to be an SQL NULL,
+**
+**  * The expression is a bound variable, and this is a reprepare, or
+**
+**  * The expression is a literal value.
+**
+** On success, *ppVal is made to point to the extracted value.  The caller
+** is responsible for ensuring that the value is eventually freed.
+*/
+static int stat4ValueFromExpr(
+  Parse *pParse,                  /* Parse context */
+  Expr *pExpr,                    /* The expression to extract a value from */
+  u8 affinity,                    /* Affinity to use */
+  struct ValueNewStat4Ctx *pAlloc,/* How to allocate space.  Or NULL */
+  sqlite3_value **ppVal           /* OUT: New value object (or NULL) */
+){
+  int rc = SQLITE_OK;
+  sqlite3_value *pVal = 0;
+  sqlite3 *db = pParse->db;
+
+  /* Skip over any TK_COLLATE nodes */
+  pExpr = sqlite3ExprSkipCollate(pExpr);
+
+  if( !pExpr ){
+    pVal = valueNew(db, pAlloc);
+    if( pVal ){
+      sqlite3VdbeMemSetNull((Mem*)pVal);
+    }
+  }else if( pExpr->op==TK_VARIABLE
+        || NEVER(pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
+  ){
+    Vdbe *v;
+    int iBindVar = pExpr->iColumn;
+    sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);
+    if( (v = pParse->pReprepare)!=0 ){
+      pVal = valueNew(db, pAlloc);
+      if( pVal ){
+        rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);
+        if( rc==SQLITE_OK ){
+          sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));
+        }
+        pVal->db = pParse->db;
+      }
+    }
+  }else{
+    rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, pAlloc);
+  }
+
+  assert( pVal==0 || pVal->db==db );
+  *ppVal = pVal;
+  return rc;
+}
+
+/*
+** This function is used to allocate and populate UnpackedRecord 
+** structures intended to be compared against sample index keys stored 
+** in the sqlite_stat4 table.
+**
+** A single call to this function attempts to populates field iVal (leftmost 
+** is 0 etc.) of the unpacked record with a value extracted from expression
+** pExpr. Extraction of values is possible if:
+**
+**  * (pExpr==0). In this case the value is assumed to be an SQL NULL,
+**
+**  * The expression is a bound variable, and this is a reprepare, or
+**
+**  * The sqlite3ValueFromExpr() function is able to extract a value 
+**    from the expression (i.e. the expression is a literal value).
+**
+** If a value can be extracted, the affinity passed as the 5th argument
+** is applied to it before it is copied into the UnpackedRecord. Output
+** parameter *pbOk is set to true if a value is extracted, or false 
+** otherwise.
+**
+** When this function is called, *ppRec must either point to an object
+** allocated by an earlier call to this function, or must be NULL. If it
+** is NULL and a value can be successfully extracted, a new UnpackedRecord
+** is allocated (and *ppRec set to point to it) before returning.
+**
+** Unless an error is encountered, SQLITE_OK is returned. It is not an
+** error if a value cannot be extracted from pExpr. If an error does
+** occur, an SQLite error code is returned.
+*/
+SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
+  Parse *pParse,                  /* Parse context */
+  Index *pIdx,                    /* Index being probed */
+  UnpackedRecord **ppRec,         /* IN/OUT: Probe record */
+  Expr *pExpr,                    /* The expression to extract a value from */
+  u8 affinity,                    /* Affinity to use */
+  int iVal,                       /* Array element to populate */
+  int *pbOk                       /* OUT: True if value was extracted */
+){
+  int rc;
+  sqlite3_value *pVal = 0;
+  struct ValueNewStat4Ctx alloc;
+
+  alloc.pParse = pParse;
+  alloc.pIdx = pIdx;
+  alloc.ppRec = ppRec;
+  alloc.iVal = iVal;
+
+  rc = stat4ValueFromExpr(pParse, pExpr, affinity, &alloc, &pVal);
+  assert( pVal==0 || pVal->db==pParse->db );
+  *pbOk = (pVal!=0);
+  return rc;
+}
+
+/*
+** Attempt to extract a value from expression pExpr using the methods
+** as described for sqlite3Stat4ProbeSetValue() above. 
+**
+** If successful, set *ppVal to point to a new value object and return 
+** SQLITE_OK. If no value can be extracted, but no other error occurs
+** (e.g. OOM), return SQLITE_OK and set *ppVal to NULL. Or, if an error
+** does occur, return an SQLite error code. The final value of *ppVal
+** is undefined in this case.
+*/
+SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(
+  Parse *pParse,                  /* Parse context */
+  Expr *pExpr,                    /* The expression to extract a value from */
+  u8 affinity,                    /* Affinity to use */
+  sqlite3_value **ppVal           /* OUT: New value object (or NULL) */
+){
+  return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal);
+}
+
+/*
+** Extract the iCol-th column from the nRec-byte record in pRec.  Write
+** the column value into *ppVal.  If *ppVal is initially NULL then a new
+** sqlite3_value object is allocated.
+**
+** If *ppVal is initially NULL then the caller is responsible for 
+** ensuring that the value written into *ppVal is eventually freed.
+*/
+SQLITE_PRIVATE int sqlite3Stat4Column(
+  sqlite3 *db,                    /* Database handle */
+  const void *pRec,               /* Pointer to buffer containing record */
+  int nRec,                       /* Size of buffer pRec in bytes */
+  int iCol,                       /* Column to extract */
+  sqlite3_value **ppVal           /* OUT: Extracted value */
+){
+  u32 t;                          /* a column type code */
+  int nHdr;                       /* Size of the header in the record */
+  int iHdr;                       /* Next unread header byte */
+  int iField;                     /* Next unread data byte */
+  int szField;                    /* Size of the current data field */
+  int i;                          /* Column index */
+  u8 *a = (u8*)pRec;              /* Typecast byte array */
+  Mem *pMem = *ppVal;             /* Write result into this Mem object */
+
+  assert( iCol>0 );
+  iHdr = getVarint32(a, nHdr);
+  if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT;
+  iField = nHdr;
+  for(i=0; i<=iCol; i++){
+    iHdr += getVarint32(&a[iHdr], t);
+    testcase( iHdr==nHdr );
+    testcase( iHdr==nHdr+1 );
+    if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT;
+    szField = sqlite3VdbeSerialTypeLen(t);
+    iField += szField;
+  }
+  testcase( iField==nRec );
+  testcase( iField==nRec+1 );
+  if( iField>nRec ) return SQLITE_CORRUPT_BKPT;
+  if( pMem==0 ){
+    pMem = *ppVal = sqlite3ValueNew(db);
+    if( pMem==0 ) return SQLITE_NOMEM_BKPT;
+  }
+  sqlite3VdbeSerialGet(&a[iField-szField], t, pMem);
+  pMem->enc = ENC(db);
+  return SQLITE_OK;
+}
+
+/*
+** Unless it is NULL, the argument must be an UnpackedRecord object returned
+** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes
+** the object.
+*/
+SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){
+  if( pRec ){
+    int i;
+    int nCol = pRec->pKeyInfo->nField+pRec->pKeyInfo->nXField;
+    Mem *aMem = pRec->aMem;
+    sqlite3 *db = aMem[0].db;
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeMemRelease(&aMem[i]);
+    }
+    sqlite3KeyInfoUnref(pRec->pKeyInfo);
+    sqlite3DbFree(db, pRec);
+  }
+}
+#endif /* ifdef SQLITE_ENABLE_STAT4 */
+
+/*
 ** Change the string value of an sqlite3_value object
 */
 SQLITE_PRIVATE void sqlite3ValueSetStr(
@@ -58158,19 +70330,28 @@ SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value *v){
 }
 
 /*
-** Return the number of bytes in the sqlite3_value object assuming
-** that it uses the encoding "enc"
+** The sqlite3ValueBytes() routine returns the number of bytes in the
+** sqlite3_value object assuming that it uses the encoding "enc".
+** The valueBytes() routine is a helper function.
 */
+static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){
+  return valueToText(pVal, enc)!=0 ? pVal->n : 0;
+}
 SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
   Mem *p = (Mem*)pVal;
-  if( (p->flags & MEM_Blob)!=0 || sqlite3ValueText(pVal, enc) ){
+  assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 );
+  if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){
+    return p->n;
+  }
+  if( (p->flags & MEM_Blob)!=0 ){
     if( p->flags & MEM_Zero ){
       return p->n + p->u.nZero;
     }else{
       return p->n;
     }
   }
-  return 0;
+  if( p->flags & MEM_Null ) return 0;
+  return valueBytes(pVal, enc);
 }
 
 /************** End of vdbemem.c *********************************************/
@@ -58187,27 +70368,16 @@ SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){
 **
 *************************************************************************
 ** This file contains code used for creating, destroying, and populating
-** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.)  Prior
-** to version 2.8.7, all this code was combined into the vdbe.c source file.
-** But that file was getting too big so this subroutines were split out.
+** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.) 
 */
-
-
-
-/*
-** When debugging the code generator in a symbolic debugger, one can
-** set the sqlite3VdbeAddopTrace to 1 and all opcodes will be printed
-** as they are added to the instruction stream.
-*/
-#ifdef SQLITE_DEBUG
-SQLITE_PRIVATE int sqlite3VdbeAddopTrace = 0;
-#endif
-
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 /*
 ** Create a new virtual database engine.
 */
-SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(sqlite3 *db){
+SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse *pParse){
+  sqlite3 *db = pParse->db;
   Vdbe *p;
   p = sqlite3DbMallocZero(db, sizeof(Vdbe) );
   if( p==0 ) return 0;
@@ -58219,16 +70389,32 @@ SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(sqlite3 *db){
   p->pPrev = 0;
   db->pVdbe = p;
   p->magic = VDBE_MAGIC_INIT;
+  p->pParse = pParse;
+  assert( pParse->aLabel==0 );
+  assert( pParse->nLabel==0 );
+  assert( pParse->nOpAlloc==0 );
+  assert( pParse->szOpAlloc==0 );
   return p;
 }
 
 /*
+** Change the error string stored in Vdbe.zErrMsg
+*/
+SQLITE_PRIVATE void sqlite3VdbeError(Vdbe *p, const char *zFormat, ...){
+  va_list ap;
+  sqlite3DbFree(p->db, p->zErrMsg);
+  va_start(ap, zFormat);
+  p->zErrMsg = sqlite3VMPrintf(p->db, zFormat, ap);
+  va_end(ap);
+}
+
+/*
 ** Remember the SQL string for a prepared statement.
 */
 SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepareV2){
   assert( isPrepareV2==1 || isPrepareV2==0 );
   if( p==0 ) return;
-#ifdef SQLITE_OMIT_TRACE
+#if defined(SQLITE_OMIT_TRACE) && !defined(SQLITE_ENABLE_SQLLOG)
   if( !isPrepareV2 ) return;
 #endif
   assert( p->zSql==0 );
@@ -58237,19 +70423,12 @@ SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepa
 }
 
 /*
-** Return the SQL associated with a prepared statement
-*/
-SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt){
-  Vdbe *p = (Vdbe *)pStmt;
-  return (p && p->isPrepareV2) ? p->zSql : 0;
-}
-
-/*
 ** Swap all content between two VDBE structures.
 */
 SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
   Vdbe tmp, *pTmp;
   char *zTmp;
+  assert( pA->db==pB->db );
   tmp = *pA;
   *pA = *pB;
   *pB = tmp;
@@ -58265,35 +70444,56 @@ SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
   pB->isPrepareV2 = pA->isPrepareV2;
 }
 
-#ifdef SQLITE_DEBUG
-/*
-** Turn tracing on or off
-*/
-SQLITE_PRIVATE void sqlite3VdbeTrace(Vdbe *p, FILE *trace){
-  p->trace = trace;
-}
-#endif
-
 /*
-** Resize the Vdbe.aOp array so that it is at least one op larger than 
-** it was.
+** Resize the Vdbe.aOp array so that it is at least nOp elements larger 
+** than its current size. nOp is guaranteed to be less than or equal
+** to 1024/sizeof(Op).
 **
 ** If an out-of-memory error occurs while resizing the array, return
-** SQLITE_NOMEM. In this case Vdbe.aOp and Vdbe.nOpAlloc remain 
+** SQLITE_NOMEM. In this case Vdbe.aOp and Parse.nOpAlloc remain 
 ** unchanged (this is so that any opcodes already allocated can be 
 ** correctly deallocated along with the rest of the Vdbe).
 */
-static int growOpArray(Vdbe *p){
+static int growOpArray(Vdbe *v, int nOp){
   VdbeOp *pNew;
+  Parse *p = v->pParse;
+
+  /* The SQLITE_TEST_REALLOC_STRESS compile-time option is designed to force
+  ** more frequent reallocs and hence provide more opportunities for 
+  ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used
+  ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array
+  ** by the minimum* amount required until the size reaches 512.  Normal
+  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
+  ** size of the op array or add 1KB of space, whichever is smaller. */
+#ifdef SQLITE_TEST_REALLOC_STRESS
+  int nNew = (p->nOpAlloc>=512 ? p->nOpAlloc*2 : p->nOpAlloc+nOp);
+#else
   int nNew = (p->nOpAlloc ? p->nOpAlloc*2 : (int)(1024/sizeof(Op)));
-  pNew = sqlite3DbRealloc(p->db, p->aOp, nNew*sizeof(Op));
+  UNUSED_PARAMETER(nOp);
+#endif
+
+  assert( nOp<=(1024/sizeof(Op)) );
+  assert( nNew>=(p->nOpAlloc+nOp) );
+  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
   if( pNew ){
-    p->nOpAlloc = sqlite3DbMallocSize(p->db, pNew)/sizeof(Op);
-    p->aOp = pNew;
+    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
+    p->nOpAlloc = p->szOpAlloc/sizeof(Op);
+    v->aOp = pNew;
   }
-  return (pNew ? SQLITE_OK : SQLITE_NOMEM);
+  return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
 }
 
+#ifdef SQLITE_DEBUG
+/* This routine is just a convenient place to set a breakpoint that will
+** fire after each opcode is inserted and displayed using
+** "PRAGMA vdbe_addoptrace=on".
+*/
+static void test_addop_breakpoint(void){
+  static int n = 0;
+  n++;
+}
+#endif
+
 /*
 ** Add a new instruction to the list of instructions current in the
 ** VDBE.  Return the address of the new instruction.
@@ -58310,17 +70510,21 @@ static int growOpArray(Vdbe *p){
 ** the sqlite3VdbeChangeP4() function to change the value of the P4
 ** operand.
 */
+static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
+  assert( p->pParse->nOpAlloc<=p->nOp );
+  if( growOpArray(p, 1) ) return 1;
+  assert( p->pParse->nOpAlloc>p->nOp );
+  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
+}
 SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   int i;
   VdbeOp *pOp;
 
   i = p->nOp;
   assert( p->magic==VDBE_MAGIC_INIT );
-  assert( op>0 && op<0xff );
-  if( p->nOpAlloc<=i ){
-    if( growOpArray(p) ){
-      return 1;
-    }
+  assert( op>=0 && op<0xff );
+  if( p->pParse->nOpAlloc<=i ){
+    return growOp3(p, op, p1, p2, p3);
   }
   p->nOp++;
   pOp = &p->aOp[i];
@@ -58331,14 +70535,31 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   pOp->p3 = p3;
   pOp->p4.p = 0;
   pOp->p4type = P4_NOTUSED;
-#ifdef SQLITE_DEBUG
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   pOp->zComment = 0;
-  if( sqlite3VdbeAddopTrace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
+#endif
+#ifdef SQLITE_DEBUG
+  if( p->db->flags & SQLITE_VdbeAddopTrace ){
+    int jj, kk;
+    Parse *pParse = p->pParse;
+    for(jj=kk=0; jj<SQLITE_N_COLCACHE; jj++){
+      struct yColCache *x = pParse->aColCache + jj;
+      if( x->iLevel>pParse->iCacheLevel || x->iReg==0 ) continue;
+      printf(" r[%d]={%d:%d}", x->iReg, x->iTable, x->iColumn);
+      kk++;
+    }
+    if( kk ) printf("\n");
+    sqlite3VdbePrintOp(0, i, &p->aOp[i]);
+    test_addop_breakpoint();
+  }
 #endif
 #ifdef VDBE_PROFILE
   pOp->cycles = 0;
   pOp->cnt = 0;
 #endif
+#ifdef SQLITE_VDBE_COVERAGE
+  pOp->iSrcLine = 0;
+#endif
   return i;
 }
 SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe *p, int op){
@@ -58351,6 +70572,43 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
   return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
 }
 
+/* Generate code for an unconditional jump to instruction iDest
+*/
+SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe *p, int iDest){
+  return sqlite3VdbeAddOp3(p, OP_Goto, 0, iDest, 0);
+}
+
+/* Generate code to cause the string zStr to be loaded into
+** register iDest
+*/
+SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe *p, int iDest, const char *zStr){
+  return sqlite3VdbeAddOp4(p, OP_String8, 0, iDest, 0, zStr, 0);
+}
+
+/*
+** Generate code that initializes multiple registers to string or integer
+** constants.  The registers begin with iDest and increase consecutively.
+** One register is initialized for each characgter in zTypes[].  For each
+** "s" character in zTypes[], the register is a string if the argument is
+** not NULL, or OP_Null if the value is a null pointer.  For each "i" character
+** in zTypes[], the register is initialized to an integer.
+*/
+SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){
+  va_list ap;
+  int i;
+  char c;
+  va_start(ap, zTypes);
+  for(i=0; (c = zTypes[i])!=0; i++){
+    if( c=='s' ){
+      const char *z = va_arg(ap, const char*);
+      sqlite3VdbeAddOp4(p, z==0 ? OP_Null : OP_String8, 0, iDest++, 0, z, 0);
+    }else{
+      assert( c=='i' );
+      sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest++);
+    }
+  }
+  va_end(ap);
+}
 
 /*
 ** Add an opcode that includes the p4 value as a pointer.
@@ -58370,16 +70628,34 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4(
 }
 
 /*
+** Add an opcode that includes the p4 value with a P4_INT64 or
+** P4_REAL type.
+*/
+SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(
+  Vdbe *p,            /* Add the opcode to this VM */
+  int op,             /* The new opcode */
+  int p1,             /* The P1 operand */
+  int p2,             /* The P2 operand */
+  int p3,             /* The P3 operand */
+  const u8 *zP4,      /* The P4 operand */
+  int p4type          /* P4 operand type */
+){
+  char *p4copy = sqlite3DbMallocRawNN(sqlite3VdbeDb(p), 8);
+  if( p4copy ) memcpy(p4copy, zP4, 8);
+  return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
+}
+
+/*
 ** Add an OP_ParseSchema opcode.  This routine is broken out from
-** sqlite3VdbeAddOp4() since it needs to also local all btrees.
+** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
+** as having been used.
 **
 ** The zWhere string must have been obtained from sqlite3_malloc().
 ** This routine will take ownership of the allocated memory.
 */
 SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
   int j;
-  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
-  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
+  sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
   for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
 }
 
@@ -58399,6 +70675,21 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(
   return addr;
 }
 
+/* Insert the end of a co-routine
+*/
+SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe *v, int regYield){
+  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
+
+  /* Clear the temporary register cache, thereby ensuring that each
+  ** co-routine has its own independent set of registers, because co-routines
+  ** might expect their registers to be preserved across an OP_Yield, and
+  ** that could cause problems if two or more co-routines are using the same
+  ** temporary register.
+  */
+  v->pParse->nTempReg = 0;
+  v->pParse->nRangeReg = 0;
+}
+
 /*
 ** Create a new symbolic label for an instruction that has yet to be
 ** coded.  The symbolic label is really just a negative number.  The
@@ -58413,20 +70704,18 @@ SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(
 **
 ** Zero is returned if a malloc() fails.
 */
-SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe *p){
-  int i;
-  i = p->nLabel++;
-  assert( p->magic==VDBE_MAGIC_INIT );
-  if( i>=p->nLabelAlloc ){
-    int n = p->nLabelAlloc*2 + 5;
-    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
-                                       n*sizeof(p->aLabel[0]));
-    p->nLabelAlloc = sqlite3DbMallocSize(p->db, p->aLabel)/sizeof(p->aLabel[0]);
+SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe *v){
+  Parse *p = v->pParse;
+  int i = p->nLabel++;
+  assert( v->magic==VDBE_MAGIC_INIT );
+  if( (i & (i-1))==0 ){
+    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel, 
+                                       (i*2+1)*sizeof(p->aLabel[0]));
   }
   if( p->aLabel ){
     p->aLabel[i] = -1;
   }
-  return -1-i;
+  return ADDR(i);
 }
 
 /*
@@ -58434,13 +70723,16 @@ SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Vdbe *p){
 ** be inserted.  The parameter "x" must have been obtained from
 ** a prior call to sqlite3VdbeMakeLabel().
 */
-SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe *p, int x){
-  int j = -1-x;
-  assert( p->magic==VDBE_MAGIC_INIT );
-  assert( j>=0 && j<p->nLabel );
+SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe *v, int x){
+  Parse *p = v->pParse;
+  int j = ADDR(x);
+  assert( v->magic==VDBE_MAGIC_INIT );
+  assert( j<p->nLabel );
+  assert( j>=0 );
   if( p->aLabel ){
-    p->aLabel[j] = p->nOp;
+    p->aLabel[j] = v->nOp;
   }
+  p->iFixedOp = v->nOp - 1;
 }
 
 /*
@@ -58450,6 +70742,13 @@ SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe *p){
   p->runOnlyOnce = 1;
 }
 
+/*
+** Mark the VDBE as one that can only be run multiple times.
+*/
+SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe *p){
+  p->runOnlyOnce = 0;
+}
+
 #ifdef SQLITE_DEBUG /* sqlite3AssertMayAbort() logic */
 
 /*
@@ -58532,6 +70831,7 @@ static Op *opIterNext(VdbeOpIter *p){
 **   *  OP_VUpdate
 **   *  OP_VRename
 **   *  OP_FkCounter with P2==0 (immediate foreign key constraint)
+**   *  OP_CreateTable and OP_InitCoroutine (for CREATE TABLE AS SELECT ...)
 **
 ** Then check that the value of Parse.mayAbort is true if an
 ** ABORT may be thrown, or false otherwise. Return true if it does
@@ -58542,6 +70842,9 @@ static Op *opIterNext(VdbeOpIter *p){
 */
 SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   int hasAbort = 0;
+  int hasFkCounter = 0;
+  int hasCreateTable = 0;
+  int hasInitCoroutine = 0;
   Op *pOp;
   VdbeOpIter sIter;
   memset(&sIter, 0, sizeof(sIter));
@@ -58550,81 +70853,132 @@ SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   while( (pOp = opIterNext(&sIter))!=0 ){
     int opcode = pOp->opcode;
     if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 
-#ifndef SQLITE_OMIT_FOREIGN_KEY
-     || (opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1) 
-#endif
      || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
-      && (pOp->p1==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
+      && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
     ){
       hasAbort = 1;
       break;
     }
+    if( opcode==OP_CreateTable ) hasCreateTable = 1;
+    if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+    if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
+      hasFkCounter = 1;
+    }
+#endif
   }
   sqlite3DbFree(v->db, sIter.apSub);
 
-  /* Return true if hasAbort==mayAbort. Or if a malloc failure occured.
+  /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
   ** If malloc failed, then the while() loop above may not have iterated
   ** through all opcodes and hasAbort may be set incorrectly. Return
   ** true for this case to prevent the assert() in the callers frame
   ** from failing.  */
-  return ( v->db->mallocFailed || hasAbort==mayAbort );
+  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter
+              || (hasCreateTable && hasInitCoroutine) );
 }
 #endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */
 
 /*
-** Loop through the program looking for P2 values that are negative
-** on jump instructions.  Each such value is a label.  Resolve the
-** label by setting the P2 value to its correct non-zero value.
+** This routine is called after all opcodes have been inserted.  It loops
+** through all the opcodes and fixes up some details.
+**
+** (1) For each jump instruction with a negative P2 value (a label)
+**     resolve the P2 value to an actual address.
+**
+** (2) Compute the maximum number of arguments used by any SQL function
+**     and store that value in *pMaxFuncArgs.
+**
+** (3) Update the Vdbe.readOnly and Vdbe.bIsReader flags to accurately
+**     indicate what the prepared statement actually does.
 **
-** This routine is called once after all opcodes have been inserted.
+** (4) Initialize the p4.xAdvance pointer on opcodes that use it.
 **
-** Variable *pMaxFuncArgs is set to the maximum value of any P2 argument 
-** to an OP_Function, OP_AggStep or OP_VFilter opcode. This is used by 
-** sqlite3VdbeMakeReady() to size the Vdbe.apArg[] array.
+** (5) Reclaim the memory allocated for storing labels.
 **
-** The Op.opflags field is set on all opcodes.
+** This routine will only function correctly if the mkopcodeh.tcl generator
+** script numbers the opcodes correctly.  Changes to this routine must be
+** coordinated with changes to mkopcodeh.tcl.
 */
 static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
-  int i;
   int nMaxArgs = *pMaxFuncArgs;
   Op *pOp;
-  int *aLabel = p->aLabel;
+  Parse *pParse = p->pParse;
+  int *aLabel = pParse->aLabel;
   p->readOnly = 1;
-  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
-    u8 opcode = pOp->opcode;
-
-    pOp->opflags = sqlite3OpcodeProperty[opcode];
-    if( opcode==OP_Function || opcode==OP_AggStep ){
-      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
-    }else if( (opcode==OP_Transaction && pOp->p2!=0) || opcode==OP_Vacuum ){
-      p->readOnly = 0;
+  p->bIsReader = 0;
+  pOp = &p->aOp[p->nOp-1];
+  while(1){
+
+    /* Only JUMP opcodes and the short list of special opcodes in the switch
+    ** below need to be considered.  The mkopcodeh.tcl generator script groups
+    ** all these opcodes together near the front of the opcode list.  Skip
+    ** any opcode that does not need processing by virtual of the fact that
+    ** it is larger than SQLITE_MX_JUMP_OPCODE, as a performance optimization.
+    */
+    if( pOp->opcode<=SQLITE_MX_JUMP_OPCODE ){
+      /* NOTE: Be sure to update mkopcodeh.tcl when adding or removing
+      ** cases from this switch! */
+      switch( pOp->opcode ){
+        case OP_Transaction: {
+          if( pOp->p2!=0 ) p->readOnly = 0;
+          /* fall thru */
+        }
+        case OP_AutoCommit:
+        case OP_Savepoint: {
+          p->bIsReader = 1;
+          break;
+        }
+#ifndef SQLITE_OMIT_WAL
+        case OP_Checkpoint:
+#endif
+        case OP_Vacuum:
+        case OP_JournalMode: {
+          p->readOnly = 0;
+          p->bIsReader = 1;
+          break;
+        }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-    }else if( opcode==OP_VUpdate ){
-      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
-    }else if( opcode==OP_VFilter ){
-      int n;
-      assert( p->nOp - i >= 3 );
-      assert( pOp[-1].opcode==OP_Integer );
-      n = pOp[-1].p1;
-      if( n>nMaxArgs ) nMaxArgs = n;
+        case OP_VUpdate: {
+          if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
+          break;
+        }
+        case OP_VFilter: {
+          int n;
+          assert( (pOp - p->aOp) >= 3 );
+          assert( pOp[-1].opcode==OP_Integer );
+          n = pOp[-1].p1;
+          if( n>nMaxArgs ) nMaxArgs = n;
+          break;
+        }
 #endif
-    }else if( opcode==OP_Next || opcode==OP_SorterNext ){
-      pOp->p4.xAdvance = sqlite3BtreeNext;
-      pOp->p4type = P4_ADVANCE;
-    }else if( opcode==OP_Prev ){
-      pOp->p4.xAdvance = sqlite3BtreePrevious;
-      pOp->p4type = P4_ADVANCE;
-    }
-
-    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
-      assert( -1-pOp->p2<p->nLabel );
-      pOp->p2 = aLabel[-1-pOp->p2];
+        case OP_Next:
+        case OP_NextIfOpen:
+        case OP_SorterNext: {
+          pOp->p4.xAdvance = sqlite3BtreeNext;
+          pOp->p4type = P4_ADVANCE;
+          break;
+        }
+        case OP_Prev:
+        case OP_PrevIfOpen: {
+          pOp->p4.xAdvance = sqlite3BtreePrevious;
+          pOp->p4type = P4_ADVANCE;
+          break;
+        }
+      }
+      if( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 && pOp->p2<0 ){
+        assert( ADDR(pOp->p2)<pParse->nLabel );
+        pOp->p2 = aLabel[ADDR(pOp->p2)];
+      }
     }
+    if( pOp==p->aOp ) break;
+    pOp--;
   }
-  sqlite3DbFree(p->db, p->aLabel);
-  p->aLabel = 0;
-
+  sqlite3DbFree(p->db, pParse->aLabel);
+  pParse->aLabel = 0;
+  pParse->nLabel = 0;
   *pMaxFuncArgs = nMaxArgs;
+  assert( p->bIsReader!=0 || DbMaskAllZero(p->btreeMask) );
 }
 
 /*
@@ -58636,6 +70990,20 @@ SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe *p){
 }
 
 /*
+** Verify that at least N opcode slots are available in p without
+** having to malloc for more space (except when compiled using
+** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing
+** to verify that certain calls to sqlite3VdbeAddOpList() can never
+** fail due to a OOM fault and hence that the return value from
+** sqlite3VdbeAddOpList() will always be non-NULL.
+*/
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
+SQLITE_PRIVATE void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
+  assert( p->nOp + N <= p->pParse->nOpAlloc );
+}
+#endif
+
+/*
 ** This function returns a pointer to the array of opcodes associated with
 ** the Vdbe passed as the first argument. It is the callers responsibility
 ** to arrange for the returned array to be eventually freed using the 
@@ -58651,7 +71019,7 @@ SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg)
   assert( aOp && !p->db->mallocFailed );
 
   /* Check that sqlite3VdbeUsesBtree() was not called on this VM */
-  assert( p->btreeMask==0 );
+  assert( DbMaskAllZero(p->btreeMask) );
 
   resolveP2Values(p, pnMaxArg);
   *pnOp = p->nOp;
@@ -58660,89 +71028,102 @@ SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg)
 }
 
 /*
-** Add a whole list of operations to the operation stack.  Return the
-** address of the first operation added.
+** Add a whole list of operations to the operation stack.  Return a
+** pointer to the first operation inserted.
+**
+** Non-zero P2 arguments to jump instructions are automatically adjusted
+** so that the jump target is relative to the first operation inserted.
 */
-SQLITE_PRIVATE int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
-  int addr;
+SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(
+  Vdbe *p,                     /* Add opcodes to the prepared statement */
+  int nOp,                     /* Number of opcodes to add */
+  VdbeOpList const *aOp,       /* The opcodes to be added */
+  int iLineno                  /* Source-file line number of first opcode */
+){
+  int i;
+  VdbeOp *pOut, *pFirst;
+  assert( nOp>0 );
   assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->nOp + nOp > p->nOpAlloc && growOpArray(p) ){
+  if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
     return 0;
   }
-  addr = p->nOp;
-  if( ALWAYS(nOp>0) ){
-    int i;
-    VdbeOpList const *pIn = aOp;
-    for(i=0; i<nOp; i++, pIn++){
-      int p2 = pIn->p2;
-      VdbeOp *pOut = &p->aOp[i+addr];
-      pOut->opcode = pIn->opcode;
-      pOut->p1 = pIn->p1;
-      if( p2<0 && (sqlite3OpcodeProperty[pOut->opcode] & OPFLG_JUMP)!=0 ){
-        pOut->p2 = addr + ADDR(p2);
-      }else{
-        pOut->p2 = p2;
-      }
-      pOut->p3 = pIn->p3;
-      pOut->p4type = P4_NOTUSED;
-      pOut->p4.p = 0;
-      pOut->p5 = 0;
-#ifdef SQLITE_DEBUG
-      pOut->zComment = 0;
-      if( sqlite3VdbeAddopTrace ){
-        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
-      }
+  pFirst = pOut = &p->aOp[p->nOp];
+  for(i=0; i<nOp; i++, aOp++, pOut++){
+    pOut->opcode = aOp->opcode;
+    pOut->p1 = aOp->p1;
+    pOut->p2 = aOp->p2;
+    assert( aOp->p2>=0 );
+    if( (sqlite3OpcodeProperty[aOp->opcode] & OPFLG_JUMP)!=0 && aOp->p2>0 ){
+      pOut->p2 += p->nOp;
+    }
+    pOut->p3 = aOp->p3;
+    pOut->p4type = P4_NOTUSED;
+    pOut->p4.p = 0;
+    pOut->p5 = 0;
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+    pOut->zComment = 0;
+#endif
+#ifdef SQLITE_VDBE_COVERAGE
+    pOut->iSrcLine = iLineno+i;
+#else
+    (void)iLineno;
 #endif
+#ifdef SQLITE_DEBUG
+    if( p->db->flags & SQLITE_VdbeAddopTrace ){
+      sqlite3VdbePrintOp(0, i+p->nOp, &p->aOp[i+p->nOp]);
     }
-    p->nOp += nOp;
+#endif
   }
-  return addr;
+  p->nOp += nOp;
+  return pFirst;
 }
 
+#if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
 /*
-** Change the value of the P1 operand for a specific instruction.
-** This routine is useful when a large program is loaded from a
-** static array using sqlite3VdbeAddOpList but we want to make a
-** few minor changes to the program.
+** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().
 */
-SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p1 = val;
+SQLITE_PRIVATE void sqlite3VdbeScanStatus(
+  Vdbe *p,                        /* VM to add scanstatus() to */
+  int addrExplain,                /* Address of OP_Explain (or 0) */
+  int addrLoop,                   /* Address of loop counter */ 
+  int addrVisit,                  /* Address of rows visited counter */
+  LogEst nEst,                    /* Estimated number of output rows */
+  const char *zName               /* Name of table or index being scanned */
+){
+  int nByte = (p->nScan+1) * sizeof(ScanStatus);
+  ScanStatus *aNew;
+  aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);
+  if( aNew ){
+    ScanStatus *pNew = &aNew[p->nScan++];
+    pNew->addrExplain = addrExplain;
+    pNew->addrLoop = addrLoop;
+    pNew->addrVisit = addrVisit;
+    pNew->nEst = nEst;
+    pNew->zName = sqlite3DbStrDup(p->db, zName);
+    p->aScan = aNew;
   }
 }
+#endif
+
 
 /*
-** Change the value of the P2 operand for a specific instruction.
-** This routine is useful for setting a jump destination.
+** Change the value of the opcode, or P1, P2, P3, or P5 operands
+** for a specific instruction.
 */
+SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe *p, u32 addr, u8 iNewOpcode){
+  sqlite3VdbeGetOp(p,addr)->opcode = iNewOpcode;
+}
+SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
+  sqlite3VdbeGetOp(p,addr)->p1 = val;
+}
 SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p2 = val;
-  }
+  sqlite3VdbeGetOp(p,addr)->p2 = val;
 }
-
-/*
-** Change the value of the P3 operand for a specific instruction.
-*/
 SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
-  assert( p!=0 );
-  if( ((u32)p->nOp)>addr ){
-    p->aOp[addr].p3 = val;
-  }
+  sqlite3VdbeGetOp(p,addr)->p3 = val;
 }
-
-/*
-** Change the value of the P5 operand for the most recently
-** added operation.
-*/
-SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
-  assert( p!=0 );
-  if( p->aOp ){
-    assert( p->nOp>0 );
-    p->aOp[p->nOp-1].p5 = val;
-  }
+SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 p5){
+  if( !p->db->mallocFailed ) p->aOp[p->nOp-1].p5 = p5;
 }
 
 /*
@@ -58750,8 +71131,8 @@ SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
 ** the address of the next instruction to be coded.
 */
 SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
-  assert( addr>=0 || p->db->mallocFailed );
-  if( addr>=0 ) sqlite3VdbeChangeP2(p, addr, p->nOp);
+  p->pParse->iFixedOp = p->nOp - 1;
+  sqlite3VdbeChangeP2(p, addr, p->nOp);
 }
 
 
@@ -58760,7 +71141,7 @@ SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){
 ** the FuncDef is not ephermal, then do nothing.
 */
 static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
-  if( ALWAYS(pDef) && (pDef->flags & SQLITE_FUNC_EPHEM)!=0 ){
+  if( (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
     sqlite3DbFree(db, pDef);
   }
 }
@@ -58770,48 +71151,57 @@ static void vdbeFreeOpArray(sqlite3 *, Op *, int);
 /*
 ** Delete a P4 value if necessary.
 */
+static SQLITE_NOINLINE void freeP4Mem(sqlite3 *db, Mem *p){
+  if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
+  sqlite3DbFree(db, p);
+}
+static SQLITE_NOINLINE void freeP4FuncCtx(sqlite3 *db, sqlite3_context *p){
+  freeEphemeralFunction(db, p->pFunc);
+  sqlite3DbFree(db, p);
+}
 static void freeP4(sqlite3 *db, int p4type, void *p4){
-  if( p4 ){
-    assert( db );
-    switch( p4type ){
-      case P4_REAL:
-      case P4_INT64:
-      case P4_DYNAMIC:
-      case P4_KEYINFO:
-      case P4_INTARRAY:
-      case P4_KEYINFO_HANDOFF: {
-        sqlite3DbFree(db, p4);
-        break;
-      }
-      case P4_MPRINTF: {
-        if( db->pnBytesFreed==0 ) sqlite3_free(p4);
-        break;
-      }
-      case P4_VDBEFUNC: {
-        VdbeFunc *pVdbeFunc = (VdbeFunc *)p4;
-        freeEphemeralFunction(db, pVdbeFunc->pFunc);
-        if( db->pnBytesFreed==0 ) sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
-        sqlite3DbFree(db, pVdbeFunc);
-        break;
-      }
-      case P4_FUNCDEF: {
-        freeEphemeralFunction(db, (FuncDef*)p4);
-        break;
-      }
-      case P4_MEM: {
-        if( db->pnBytesFreed==0 ){
-          sqlite3ValueFree((sqlite3_value*)p4);
-        }else{
-          Mem *p = (Mem*)p4;
-          sqlite3DbFree(db, p->zMalloc);
-          sqlite3DbFree(db, p);
-        }
-        break;
-      }
-      case P4_VTAB : {
-        if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
-        break;
+  assert( db );
+  switch( p4type ){
+    case P4_FUNCCTX: {
+      freeP4FuncCtx(db, (sqlite3_context*)p4);
+      break;
+    }
+    case P4_REAL:
+    case P4_INT64:
+    case P4_DYNAMIC:
+    case P4_INTARRAY: {
+      sqlite3DbFree(db, p4);
+      break;
+    }
+    case P4_KEYINFO: {
+      if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);
+      break;
+    }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+    case P4_EXPR: {
+      sqlite3ExprDelete(db, (Expr*)p4);
+      break;
+    }
+#endif
+    case P4_MPRINTF: {
+      if( db->pnBytesFreed==0 ) sqlite3_free(p4);
+      break;
+    }
+    case P4_FUNCDEF: {
+      freeEphemeralFunction(db, (FuncDef*)p4);
+      break;
+    }
+    case P4_MEM: {
+      if( db->pnBytesFreed==0 ){
+        sqlite3ValueFree((sqlite3_value*)p4);
+      }else{
+        freeP4Mem(db, (Mem*)p4);
       }
+      break;
+    }
+    case P4_VTAB : {
+      if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
+      break;
     }
   }
 }
@@ -58825,8 +71215,8 @@ static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
   if( aOp ){
     Op *pOp;
     for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
-      freeP4(db, pOp->p4type, pOp->p4.p);
-#ifdef SQLITE_DEBUG
+      if( pOp->p4type ) freeP4(db, pOp->p4type, pOp->p4.p);
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
       sqlite3DbFree(db, pOp->zComment);
 #endif     
     }
@@ -58847,13 +71237,27 @@ SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){
 /*
 ** Change the opcode at addr into OP_Noop
 */
-SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
-  if( p->aOp ){
-    VdbeOp *pOp = &p->aOp[addr];
-    sqlite3 *db = p->db;
-    freeP4(db, pOp->p4type, pOp->p4.p);
-    memset(pOp, 0, sizeof(pOp[0]));
-    pOp->opcode = OP_Noop;
+SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
+  VdbeOp *pOp;
+  if( p->db->mallocFailed ) return 0;
+  assert( addr>=0 && addr<p->nOp );
+  pOp = &p->aOp[addr];
+  freeP4(p->db, pOp->p4type, pOp->p4.p);
+  pOp->p4type = P4_NOTUSED;
+  pOp->p4.z = 0;
+  pOp->opcode = OP_Noop;
+  return 1;
+}
+
+/*
+** If the last opcode is "op" and it is not a jump destination,
+** then remove it.  Return true if and only if an opcode was removed.
+*/
+SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
+  if( (p->nOp-1)>(p->pParse->iFixedOp) && p->aOp[p->nOp-1].opcode==op ){
+    return sqlite3VdbeChangeToNoop(p, p->nOp-1);
+  }else{
+    return 0;
   }
 }
 
@@ -58867,14 +71271,6 @@ SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
 ** the string is made into memory obtained from sqlite3_malloc().
 ** A value of n==0 means copy bytes of zP4 up to and including the
 ** first null byte.  If n>0 then copy n+1 bytes of zP4.
-**
-** If n==P4_KEYINFO it means that zP4 is a pointer to a KeyInfo structure.
-** A copy is made of the KeyInfo structure into memory obtained from
-** sqlite3_malloc, to be freed when the Vdbe is finalized.
-** n==P4_KEYINFO_HANDOFF indicates that zP4 points to a KeyInfo structure
-** stored in memory that the caller has obtained from sqlite3_malloc. The 
-** caller should not free the allocation, it will be freed when the Vdbe is
-** finalized.
 ** 
 ** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
 ** to a string or structure that is guaranteed to exist for the lifetime of
@@ -58882,16 +71278,34 @@ SQLITE_PRIVATE void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
 **
 ** If addr<0 then change P4 on the most recently inserted instruction.
 */
+static void SQLITE_NOINLINE vdbeChangeP4Full(
+  Vdbe *p,
+  Op *pOp,
+  const char *zP4,
+  int n
+){
+  if( pOp->p4type ){
+    freeP4(p->db, pOp->p4type, pOp->p4.p);
+    pOp->p4type = 0;
+    pOp->p4.p = 0;
+  }
+  if( n<0 ){
+    sqlite3VdbeChangeP4(p, (int)(pOp - p->aOp), zP4, n);
+  }else{
+    if( n==0 ) n = sqlite3Strlen30(zP4);
+    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
+    pOp->p4type = P4_DYNAMIC;
+  }
+}
 SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
   Op *pOp;
   sqlite3 *db;
   assert( p!=0 );
   db = p->db;
   assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->aOp==0 || db->mallocFailed ){
-    if ( n!=P4_KEYINFO && n!=P4_VTAB ) {
-      freeP4(db, n, (void*)*(char**)&zP4);
-    }
+  assert( p->aOp!=0 || db->mallocFailed );
+  if( db->mallocFailed ){
+    if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);
     return;
   }
   assert( p->nOp>0 );
@@ -58900,58 +71314,38 @@ SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int
     addr = p->nOp - 1;
   }
   pOp = &p->aOp[addr];
-  freeP4(db, pOp->p4type, pOp->p4.p);
-  pOp->p4.p = 0;
+  if( n>=0 || pOp->p4type ){
+    vdbeChangeP4Full(p, pOp, zP4, n);
+    return;
+  }
   if( n==P4_INT32 ){
     /* Note: this cast is safe, because the origin data point was an int
     ** that was cast to a (const char *). */
     pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
     pOp->p4type = P4_INT32;
-  }else if( zP4==0 ){
-    pOp->p4.p = 0;
-    pOp->p4type = P4_NOTUSED;
-  }else if( n==P4_KEYINFO ){
-    KeyInfo *pKeyInfo;
-    int nField, nByte;
-
-    nField = ((KeyInfo*)zP4)->nField;
-    nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
-    pKeyInfo = sqlite3DbMallocRaw(0, nByte);
-    pOp->p4.pKeyInfo = pKeyInfo;
-    if( pKeyInfo ){
-      u8 *aSortOrder;
-      memcpy((char*)pKeyInfo, zP4, nByte - nField);
-      aSortOrder = pKeyInfo->aSortOrder;
-      if( aSortOrder ){
-        pKeyInfo->aSortOrder = (unsigned char*)&pKeyInfo->aColl[nField];
-        memcpy(pKeyInfo->aSortOrder, aSortOrder, nField);
-      }
-      pOp->p4type = P4_KEYINFO;
-    }else{
-      p->db->mallocFailed = 1;
-      pOp->p4type = P4_NOTUSED;
-    }
-  }else if( n==P4_KEYINFO_HANDOFF ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_KEYINFO;
-  }else if( n==P4_VTAB ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_VTAB;
-    sqlite3VtabLock((VTable *)zP4);
-    assert( ((VTable *)zP4)->db==p->db );
-  }else if( n<0 ){
+  }else if( zP4!=0 ){
+    assert( n<0 );
     pOp->p4.p = (void*)zP4;
     pOp->p4type = (signed char)n;
-  }else{
-    if( n==0 ) n = sqlite3Strlen30(zP4);
-    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
-    pOp->p4type = P4_DYNAMIC;
+    if( n==P4_VTAB ) sqlite3VtabLock((VTable*)zP4);
   }
 }
 
-#ifndef NDEBUG
 /*
-** Change the comment on the the most recently coded instruction.  Or
+** Set the P4 on the most recently added opcode to the KeyInfo for the
+** index given.
+*/
+SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse *pParse, Index *pIdx){
+  Vdbe *v = pParse->pVdbe;
+  assert( v!=0 );
+  assert( pIdx!=0 );
+  sqlite3VdbeChangeP4(v, -1, (char*)sqlite3KeyInfoOfIndex(pParse, pIdx),
+                      P4_KEYINFO);
+}
+
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+/*
+** Change the comment on the most recently coded instruction.  Or
 ** insert a No-op and add the comment to that new instruction.  This
 ** makes the code easier to read during debugging.  None of this happens
 ** in a production build.
@@ -58984,6 +71378,15 @@ SQLITE_PRIVATE void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){
 }
 #endif  /* NDEBUG */
 
+#ifdef SQLITE_VDBE_COVERAGE
+/*
+** Set the value if the iSrcLine field for the previously coded instruction.
+*/
+SQLITE_PRIVATE void sqlite3VdbeSetLineNumber(Vdbe *v, int iLine){
+  sqlite3VdbeGetOp(v,-1)->iSrcLine = iLine;
+}
+#endif /* SQLITE_VDBE_COVERAGE */
+
 /*
 ** Return the opcode for a given address.  If the address is -1, then
 ** return the most recently inserted opcode.
@@ -58992,18 +71395,10 @@ SQLITE_PRIVATE void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){
 ** routine, then a pointer to a dummy VdbeOp will be returned.  That opcode
 ** is readable but not writable, though it is cast to a writable value.
 ** The return of a dummy opcode allows the call to continue functioning
-** after a OOM fault without having to check to see if the return from 
+** after an OOM fault without having to check to see if the return from 
 ** this routine is a valid pointer.  But because the dummy.opcode is 0,
 ** dummy will never be written to.  This is verified by code inspection and
 ** by running with Valgrind.
-**
-** About the #ifdef SQLITE_OMIT_TRACE:  Normally, this routine is never called
-** unless p->nOp>0.  This is because in the absense of SQLITE_OMIT_TRACE,
-** an OP_Trace instruction is always inserted by sqlite3VdbeGet() as soon as
-** a new VDBE is created.  So we are free to set addr to p->nOp-1 without
-** having to double-check to make sure that the result is non-negative. But
-** if SQLITE_OMIT_TRACE is defined, the OP_Trace is omitted and we do need to
-** check the value of p->nOp-1 before continuing.
 */
 SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
   /* C89 specifies that the constant "dummy" will be initialized to all
@@ -59011,9 +71406,6 @@ SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
   static VdbeOp dummy;  /* Ignore the MSVC warning about no initializer */
   assert( p->magic==VDBE_MAGIC_INIT );
   if( addr<0 ){
-#ifdef SQLITE_OMIT_TRACE
-    if( p->nOp==0 ) return (VdbeOp*)&dummy;
-#endif
     addr = p->nOp - 1;
   }
   assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
@@ -59024,77 +71416,240 @@ SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
   }
 }
 
-#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
-     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
+#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)
+/*
+** Return an integer value for one of the parameters to the opcode pOp
+** determined by character c.
+*/
+static int translateP(char c, const Op *pOp){
+  if( c=='1' ) return pOp->p1;
+  if( c=='2' ) return pOp->p2;
+  if( c=='3' ) return pOp->p3;
+  if( c=='4' ) return pOp->p4.i;
+  return pOp->p5;
+}
+
+/*
+** Compute a string for the "comment" field of a VDBE opcode listing.
+**
+** The Synopsis: field in comments in the vdbe.c source file gets converted
+** to an extra string that is appended to the sqlite3OpcodeName().  In the
+** absence of other comments, this synopsis becomes the comment on the opcode.
+** Some translation occurs:
+**
+**       "PX"      ->  "r[X]"
+**       "PX@PY"   ->  "r[X..X+Y-1]"  or "r[x]" if y is 0 or 1
+**       "PX@PY+1" ->  "r[X..X+Y]"    or "r[x]" if y is 0
+**       "PY..PY"  ->  "r[X..Y]"      or "r[x]" if y<=x
+*/
+static int displayComment(
+  const Op *pOp,     /* The opcode to be commented */
+  const char *zP4,   /* Previously obtained value for P4 */
+  char *zTemp,       /* Write result here */
+  int nTemp          /* Space available in zTemp[] */
+){
+  const char *zOpName;
+  const char *zSynopsis;
+  int nOpName;
+  int ii, jj;
+  zOpName = sqlite3OpcodeName(pOp->opcode);
+  nOpName = sqlite3Strlen30(zOpName);
+  if( zOpName[nOpName+1] ){
+    int seenCom = 0;
+    char c;
+    zSynopsis = zOpName += nOpName + 1;
+    for(ii=jj=0; jj<nTemp-1 && (c = zSynopsis[ii])!=0; ii++){
+      if( c=='P' ){
+        c = zSynopsis[++ii];
+        if( c=='4' ){
+          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", zP4);
+        }else if( c=='X' ){
+          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", pOp->zComment);
+          seenCom = 1;
+        }else{
+          int v1 = translateP(c, pOp);
+          int v2;
+          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%d", v1);
+          if( strncmp(zSynopsis+ii+1, "@P", 2)==0 ){
+            ii += 3;
+            jj += sqlite3Strlen30(zTemp+jj);
+            v2 = translateP(zSynopsis[ii], pOp);
+            if( strncmp(zSynopsis+ii+1,"+1",2)==0 ){
+              ii += 2;
+              v2++;
+            }
+            if( v2>1 ){
+              sqlite3_snprintf(nTemp-jj, zTemp+jj, "..%d", v1+v2-1);
+            }
+          }else if( strncmp(zSynopsis+ii+1, "..P3", 4)==0 && pOp->p3==0 ){
+            ii += 4;
+          }
+        }
+        jj += sqlite3Strlen30(zTemp+jj);
+      }else{
+        zTemp[jj++] = c;
+      }
+    }
+    if( !seenCom && jj<nTemp-5 && pOp->zComment ){
+      sqlite3_snprintf(nTemp-jj, zTemp+jj, "; %s", pOp->zComment);
+      jj += sqlite3Strlen30(zTemp+jj);
+    }
+    if( jj<nTemp ) zTemp[jj] = 0;
+  }else if( pOp->zComment ){
+    sqlite3_snprintf(nTemp, zTemp, "%s", pOp->zComment);
+    jj = sqlite3Strlen30(zTemp);
+  }else{
+    zTemp[0] = 0;
+    jj = 0;
+  }
+  return jj;
+}
+#endif /* SQLITE_DEBUG */
+
+#if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
+/*
+** Translate the P4.pExpr value for an OP_CursorHint opcode into text
+** that can be displayed in the P4 column of EXPLAIN output.
+*/
+static void displayP4Expr(StrAccum *p, Expr *pExpr){
+  const char *zOp = 0;
+  switch( pExpr->op ){
+    case TK_STRING:
+      sqlite3XPrintf(p, "%Q", pExpr->u.zToken);
+      break;
+    case TK_INTEGER:
+      sqlite3XPrintf(p, "%d", pExpr->u.iValue);
+      break;
+    case TK_NULL:
+      sqlite3XPrintf(p, "NULL");
+      break;
+    case TK_REGISTER: {
+      sqlite3XPrintf(p, "r[%d]", pExpr->iTable);
+      break;
+    }
+    case TK_COLUMN: {
+      if( pExpr->iColumn<0 ){
+        sqlite3XPrintf(p, "rowid");
+      }else{
+        sqlite3XPrintf(p, "c%d", (int)pExpr->iColumn);
+      }
+      break;
+    }
+    case TK_LT:      zOp = "LT";      break;
+    case TK_LE:      zOp = "LE";      break;
+    case TK_GT:      zOp = "GT";      break;
+    case TK_GE:      zOp = "GE";      break;
+    case TK_NE:      zOp = "NE";      break;
+    case TK_EQ:      zOp = "EQ";      break;
+    case TK_IS:      zOp = "IS";      break;
+    case TK_ISNOT:   zOp = "ISNOT";   break;
+    case TK_AND:     zOp = "AND";     break;
+    case TK_OR:      zOp = "OR";      break;
+    case TK_PLUS:    zOp = "ADD";     break;
+    case TK_STAR:    zOp = "MUL";     break;
+    case TK_MINUS:   zOp = "SUB";     break;
+    case TK_REM:     zOp = "REM";     break;
+    case TK_BITAND:  zOp = "BITAND";  break;
+    case TK_BITOR:   zOp = "BITOR";   break;
+    case TK_SLASH:   zOp = "DIV";     break;
+    case TK_LSHIFT:  zOp = "LSHIFT";  break;
+    case TK_RSHIFT:  zOp = "RSHIFT";  break;
+    case TK_CONCAT:  zOp = "CONCAT";  break;
+    case TK_UMINUS:  zOp = "MINUS";   break;
+    case TK_UPLUS:   zOp = "PLUS";    break;
+    case TK_BITNOT:  zOp = "BITNOT";  break;
+    case TK_NOT:     zOp = "NOT";     break;
+    case TK_ISNULL:  zOp = "ISNULL";  break;
+    case TK_NOTNULL: zOp = "NOTNULL"; break;
+
+    default:
+      sqlite3XPrintf(p, "%s", "expr");
+      break;
+  }
+
+  if( zOp ){
+    sqlite3XPrintf(p, "%s(", zOp);
+    displayP4Expr(p, pExpr->pLeft);
+    if( pExpr->pRight ){
+      sqlite3StrAccumAppend(p, ",", 1);
+      displayP4Expr(p, pExpr->pRight);
+    }
+    sqlite3StrAccumAppend(p, ")", 1);
+  }
+}
+#endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */
+
+
+#if VDBE_DISPLAY_P4
 /*
 ** Compute a string that describes the P4 parameter for an opcode.
 ** Use zTemp for any required temporary buffer space.
 */
 static char *displayP4(Op *pOp, char *zTemp, int nTemp){
   char *zP4 = zTemp;
+  StrAccum x;
   assert( nTemp>=20 );
+  sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
   switch( pOp->p4type ){
-    case P4_KEYINFO_STATIC:
     case P4_KEYINFO: {
-      int i, j;
+      int j;
       KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
-      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
-      i = sqlite3Strlen30(zTemp);
+      assert( pKeyInfo->aSortOrder!=0 );
+      sqlite3XPrintf(&x, "k(%d", pKeyInfo->nField);
       for(j=0; j<pKeyInfo->nField; j++){
         CollSeq *pColl = pKeyInfo->aColl[j];
-        if( pColl ){
-          int n = sqlite3Strlen30(pColl->zName);
-          if( i+n>nTemp-6 ){
-            memcpy(&zTemp[i],",...",4);
-            break;
-          }
-          zTemp[i++] = ',';
-          if( pKeyInfo->aSortOrder && pKeyInfo->aSortOrder[j] ){
-            zTemp[i++] = '-';
-          }
-          memcpy(&zTemp[i], pColl->zName,n+1);
-          i += n;
-        }else if( i+4<nTemp-6 ){
-          memcpy(&zTemp[i],",nil",4);
-          i += 4;
-        }
+        const char *zColl = pColl ? pColl->zName : "";
+        if( strcmp(zColl, "BINARY")==0 ) zColl = "B";
+        sqlite3XPrintf(&x, ",%s%s", pKeyInfo->aSortOrder[j] ? "-" : "", zColl);
       }
-      zTemp[i++] = ')';
-      zTemp[i] = 0;
-      assert( i<nTemp );
+      sqlite3StrAccumAppend(&x, ")", 1);
       break;
     }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+    case P4_EXPR: {
+      displayP4Expr(&x, pOp->p4.pExpr);
+      break;
+    }
+#endif
     case P4_COLLSEQ: {
       CollSeq *pColl = pOp->p4.pColl;
-      sqlite3_snprintf(nTemp, zTemp, "collseq(%.20s)", pColl->zName);
+      sqlite3XPrintf(&x, "(%.20s)", pColl->zName);
       break;
     }
     case P4_FUNCDEF: {
       FuncDef *pDef = pOp->p4.pFunc;
-      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
+      sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
       break;
     }
+#ifdef SQLITE_DEBUG
+    case P4_FUNCCTX: {
+      FuncDef *pDef = pOp->p4.pCtx->pFunc;
+      sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
+      break;
+    }
+#endif
     case P4_INT64: {
-      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
+      sqlite3XPrintf(&x, "%lld", *pOp->p4.pI64);
       break;
     }
     case P4_INT32: {
-      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
+      sqlite3XPrintf(&x, "%d", pOp->p4.i);
       break;
     }
     case P4_REAL: {
-      sqlite3_snprintf(nTemp, zTemp, "%.16g", *pOp->p4.pReal);
+      sqlite3XPrintf(&x, "%.16g", *pOp->p4.pReal);
       break;
     }
     case P4_MEM: {
       Mem *pMem = pOp->p4.pMem;
-      assert( (pMem->flags & MEM_Null)==0 );
       if( pMem->flags & MEM_Str ){
         zP4 = pMem->z;
       }else if( pMem->flags & MEM_Int ){
-        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
+        sqlite3XPrintf(&x, "%lld", pMem->u.i);
       }else if( pMem->flags & MEM_Real ){
-        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->r);
+        sqlite3XPrintf(&x, "%.16g", pMem->u.r);
+      }else if( pMem->flags & MEM_Null ){
+        zP4 = "NULL";
       }else{
         assert( pMem->flags & MEM_Blob );
         zP4 = "(blob)";
@@ -59104,22 +71659,34 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     case P4_VTAB: {
       sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;
-      sqlite3_snprintf(nTemp, zTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
+      sqlite3XPrintf(&x, "vtab:%p", pVtab);
       break;
     }
 #endif
     case P4_INTARRAY: {
-      sqlite3_snprintf(nTemp, zTemp, "intarray");
+      int i;
+      int *ai = pOp->p4.ai;
+      int n = ai[0];   /* The first element of an INTARRAY is always the
+                       ** count of the number of elements to follow */
+      for(i=1; i<n; i++){
+        sqlite3XPrintf(&x, ",%d", ai[i]);
+      }
+      zTemp[0] = '[';
+      sqlite3StrAccumAppend(&x, "]", 1);
       break;
     }
     case P4_SUBPROGRAM: {
-      sqlite3_snprintf(nTemp, zTemp, "program");
+      sqlite3XPrintf(&x, "program");
       break;
     }
     case P4_ADVANCE: {
       zTemp[0] = 0;
       break;
     }
+    case P4_TABLE: {
+      sqlite3XPrintf(&x, "%s", pOp->p4.pTab->zName);
+      break;
+    }
     default: {
       zP4 = pOp->p4.z;
       if( zP4==0 ){
@@ -59128,28 +71695,30 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
       }
     }
   }
+  sqlite3StrAccumFinish(&x);
   assert( zP4!=0 );
   return zP4;
 }
-#endif
+#endif /* VDBE_DISPLAY_P4 */
 
 /*
 ** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
 **
 ** The prepared statements need to know in advance the complete set of
-** attached databases that they will be using.  A mask of these databases
-** is maintained in p->btreeMask and is used for locking and other purposes.
+** attached databases that will be use.  A mask of these databases
+** is maintained in p->btreeMask.  The p->lockMask value is the subset of
+** p->btreeMask of databases that will require a lock.
 */
 SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe *p, int i){
   assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 );
   assert( i<(int)sizeof(p->btreeMask)*8 );
-  p->btreeMask |= ((yDbMask)1)<<i;
+  DbMaskSet(p->btreeMask, i);
   if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){
-    p->lockMask |= ((yDbMask)1)<<i;
+    DbMaskSet(p->lockMask, i);
   }
 }
 
-#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
+#if !defined(SQLITE_OMIT_SHARED_CACHE)
 /*
 ** If SQLite is compiled to support shared-cache mode and to be threadsafe,
 ** this routine obtains the mutex associated with each BtShared structure
@@ -59173,16 +71742,15 @@ SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe *p, int i){
 */
 SQLITE_PRIVATE void sqlite3VdbeEnter(Vdbe *p){
   int i;
-  yDbMask mask;
   sqlite3 *db;
   Db *aDb;
   int nDb;
-  if( p->lockMask==0 ) return;  /* The common case */
+  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
   db = p->db;
   aDb = db->aDb;
   nDb = db->nDb;
-  for(i=0, mask=1; i<nDb; i++, mask += mask){
-    if( i!=1 && (mask & p->lockMask)!=0 && ALWAYS(aDb[i].pBt!=0) ){
+  for(i=0; i<nDb; i++){
+    if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
       sqlite3BtreeEnter(aDb[i].pBt);
     }
   }
@@ -59193,22 +71761,24 @@ SQLITE_PRIVATE void sqlite3VdbeEnter(Vdbe *p){
 /*
 ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().
 */
-SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
+static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){
   int i;
-  yDbMask mask;
   sqlite3 *db;
   Db *aDb;
   int nDb;
-  if( p->lockMask==0 ) return;  /* The common case */
   db = p->db;
   aDb = db->aDb;
   nDb = db->nDb;
-  for(i=0, mask=1; i<nDb; i++, mask += mask){
-    if( i!=1 && (mask & p->lockMask)!=0 && ALWAYS(aDb[i].pBt!=0) ){
+  for(i=0; i<nDb; i++){
+    if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
       sqlite3BtreeLeave(aDb[i].pBt);
     }
   }
 }
+SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
+  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
+  vdbeLeave(p);
+}
 #endif
 
 #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
@@ -59218,16 +71788,21 @@ SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){
 SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
   char *zP4;
   char zPtr[50];
-  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-4s %.2X %s\n";
+  char zCom[100];
+  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";
   if( pOut==0 ) pOut = stdout;
   zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
-  fprintf(pOut, zFormat1, pc, 
-      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
-#ifdef SQLITE_DEBUG
-      pOp->zComment ? pOp->zComment : ""
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+  displayComment(pOp, zP4, zCom, sizeof(zCom));
 #else
-      ""
+  zCom[0] = 0;
 #endif
+  /* NB:  The sqlite3OpcodeName() function is implemented by code created
+  ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the
+  ** information from the vdbe.c source text */
+  fprintf(pOut, zFormat1, pc, 
+      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
+      zCom
   );
   fflush(pOut);
 }
@@ -59238,17 +71813,17 @@ SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
 */
 static void releaseMemArray(Mem *p, int N){
   if( p && N ){
-    Mem *pEnd;
+    Mem *pEnd = &p[N];
     sqlite3 *db = p->db;
-    u8 malloc_failed = db->mallocFailed;
     if( db->pnBytesFreed ){
-      for(pEnd=&p[N]; p<pEnd; p++){
-        sqlite3DbFree(db, p->zMalloc);
-      }
+      do{
+        if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
+      }while( (++p)<pEnd );
       return;
     }
-    for(pEnd=&p[N]; p<pEnd; p++){
+    do{
       assert( (&p[1])==pEnd || p[0].db==p[1].db );
+      assert( sqlite3VdbeCheckMemInvariants(p) );
 
       /* This block is really an inlined version of sqlite3VdbeMemRelease()
       ** that takes advantage of the fact that the memory cell value is 
@@ -59262,16 +71837,19 @@ static void releaseMemArray(Mem *p, int N){
       ** with no indexes using a single prepared INSERT statement, bind() 
       ** and reset(). Inserts are grouped into a transaction.
       */
+      testcase( p->flags & MEM_Agg );
+      testcase( p->flags & MEM_Dyn );
+      testcase( p->flags & MEM_Frame );
+      testcase( p->flags & MEM_RowSet );
       if( p->flags&(MEM_Agg|MEM_Dyn|MEM_Frame|MEM_RowSet) ){
         sqlite3VdbeMemRelease(p);
-      }else if( p->zMalloc ){
+      }else if( p->szMalloc ){
         sqlite3DbFree(db, p->zMalloc);
-        p->zMalloc = 0;
+        p->szMalloc = 0;
       }
 
-      p->flags = MEM_Null;
-    }
-    db->mallocFailed = malloc_failed;
+      p->flags = MEM_Undefined;
+    }while( (++p)<pEnd );
   }
 }
 
@@ -59287,6 +71865,7 @@ SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame *p){
     sqlite3VdbeFreeCursor(p->v, apCsr[i]);
   }
   releaseMemArray(aMem, p->nChildMem);
+  sqlite3VdbeDeleteAuxData(p->v->db, &p->pAuxData, -1, 0);
   sqlite3DbFree(p->v->db, p);
 }
 
@@ -59329,10 +71908,10 @@ SQLITE_PRIVATE int sqlite3VdbeList(
   releaseMemArray(pMem, 8);
   p->pResultSet = 0;
 
-  if( p->rc==SQLITE_NOMEM ){
+  if( p->rc==SQLITE_NOMEM_BKPT ){
     /* This happens if a malloc() inside a call to sqlite3_column_text() or
     ** sqlite3_column_text16() failed.  */
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     return SQLITE_ERROR;
   }
 
@@ -59371,9 +71950,9 @@ SQLITE_PRIVATE int sqlite3VdbeList(
   }else if( db->u1.isInterrupted ){
     p->rc = SQLITE_INTERRUPT;
     rc = SQLITE_ERROR;
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(p->rc));
+    sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
   }else{
-    char *z;
+    char *zP4;
     Op *pOp;
     if( i<p->nOp ){
       /* The output line number is small enough that we are still in the
@@ -59391,15 +71970,13 @@ SQLITE_PRIVATE int sqlite3VdbeList(
     }
     if( p->explain==1 ){
       pMem->flags = MEM_Int;
-      pMem->type = SQLITE_INTEGER;
       pMem->u.i = i;                                /* Program counter */
       pMem++;
   
       pMem->flags = MEM_Static|MEM_Str|MEM_Term;
-      pMem->z = (char*)sqlite3OpcodeName(pOp->opcode);  /* Opcode */
+      pMem->z = (char*)sqlite3OpcodeName(pOp->opcode); /* Opcode */
       assert( pMem->z!=0 );
       pMem->n = sqlite3Strlen30(pMem->z);
-      pMem->type = SQLITE_TEXT;
       pMem->enc = SQLITE_UTF8;
       pMem++;
 
@@ -59414,7 +71991,7 @@ SQLITE_PRIVATE int sqlite3VdbeList(
         for(j=0; j<nSub; j++){
           if( apSub[j]==pOp->p4.pProgram ) break;
         }
-        if( j==nSub && SQLITE_OK==sqlite3VdbeMemGrow(pSub, nByte, 1) ){
+        if( j==nSub && SQLITE_OK==sqlite3VdbeMemGrow(pSub, nByte, nSub!=0) ){
           apSub = (SubProgram **)pSub->z;
           apSub[nSub++] = pOp->p4.pProgram;
           pSub->flags |= MEM_Blob;
@@ -59425,60 +72002,53 @@ SQLITE_PRIVATE int sqlite3VdbeList(
 
     pMem->flags = MEM_Int;
     pMem->u.i = pOp->p1;                          /* P1 */
-    pMem->type = SQLITE_INTEGER;
     pMem++;
 
     pMem->flags = MEM_Int;
     pMem->u.i = pOp->p2;                          /* P2 */
-    pMem->type = SQLITE_INTEGER;
     pMem++;
 
     pMem->flags = MEM_Int;
     pMem->u.i = pOp->p3;                          /* P3 */
-    pMem->type = SQLITE_INTEGER;
     pMem++;
 
-    if( sqlite3VdbeMemGrow(pMem, 32, 0) ){            /* P4 */
+    if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
       assert( p->db->mallocFailed );
       return SQLITE_ERROR;
     }
-    pMem->flags = MEM_Dyn|MEM_Str|MEM_Term;
-    z = displayP4(pOp, pMem->z, 32);
-    if( z!=pMem->z ){
-      sqlite3VdbeMemSetStr(pMem, z, -1, SQLITE_UTF8, 0);
+    pMem->flags = MEM_Str|MEM_Term;
+    zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
+    if( zP4!=pMem->z ){
+      sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
     }else{
       assert( pMem->z!=0 );
       pMem->n = sqlite3Strlen30(pMem->z);
       pMem->enc = SQLITE_UTF8;
     }
-    pMem->type = SQLITE_TEXT;
     pMem++;
 
     if( p->explain==1 ){
-      if( sqlite3VdbeMemGrow(pMem, 4, 0) ){
+      if( sqlite3VdbeMemClearAndResize(pMem, 4) ){
         assert( p->db->mallocFailed );
         return SQLITE_ERROR;
       }
-      pMem->flags = MEM_Dyn|MEM_Str|MEM_Term;
+      pMem->flags = MEM_Str|MEM_Term;
       pMem->n = 2;
       sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5);   /* P5 */
-      pMem->type = SQLITE_TEXT;
       pMem->enc = SQLITE_UTF8;
       pMem++;
   
-#ifdef SQLITE_DEBUG
-      if( pOp->zComment ){
-        pMem->flags = MEM_Str|MEM_Term;
-        pMem->z = pOp->zComment;
-        pMem->n = sqlite3Strlen30(pMem->z);
-        pMem->enc = SQLITE_UTF8;
-        pMem->type = SQLITE_TEXT;
-      }else
-#endif
-      {
-        pMem->flags = MEM_Null;                       /* Comment */
-        pMem->type = SQLITE_NULL;
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+      if( sqlite3VdbeMemClearAndResize(pMem, 500) ){
+        assert( p->db->mallocFailed );
+        return SQLITE_ERROR;
       }
+      pMem->flags = MEM_Str|MEM_Term;
+      pMem->n = displayComment(pOp, zP4, pMem->z, 500);
+      pMem->enc = SQLITE_UTF8;
+#else
+      pMem->flags = MEM_Null;                       /* Comment */
+#endif
     }
 
     p->nResColumn = 8 - 4*(p->explain-1);
@@ -59495,15 +72065,17 @@ SQLITE_PRIVATE int sqlite3VdbeList(
 ** Print the SQL that was used to generate a VDBE program.
 */
 SQLITE_PRIVATE void sqlite3VdbePrintSql(Vdbe *p){
-  int nOp = p->nOp;
-  VdbeOp *pOp;
-  if( nOp<1 ) return;
-  pOp = &p->aOp[0];
-  if( pOp->opcode==OP_Trace && pOp->p4.z!=0 ){
-    const char *z = pOp->p4.z;
-    while( sqlite3Isspace(*z) ) z++;
-    printf("SQL: [%s]\n", z);
+  const char *z = 0;
+  if( p->zSql ){
+    z = p->zSql;
+  }else if( p->nOp>=1 ){
+    const VdbeOp *pOp = &p->aOp[0];
+    if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
+      z = pOp->p4.z;
+      while( sqlite3Isspace(*z) ) z++;
+    }
   }
+  if( z ) printf("SQL: [%s]\n", z);
 }
 #endif
 
@@ -59517,7 +72089,7 @@ SQLITE_PRIVATE void sqlite3VdbeIOTraceSql(Vdbe *p){
   if( sqlite3IoTrace==0 ) return;
   if( nOp<1 ) return;
   pOp = &p->aOp[0];
-  if( pOp->opcode==OP_Trace && pOp->p4.z!=0 ){
+  if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
     int i, j;
     char z[1000];
     sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.z);
@@ -59537,43 +72109,46 @@ SQLITE_PRIVATE void sqlite3VdbeIOTraceSql(Vdbe *p){
 }
 #endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */
 
-/*
-** Allocate space from a fixed size buffer and return a pointer to
-** that space.  If insufficient space is available, return NULL.
-**
-** The pBuf parameter is the initial value of a pointer which will
-** receive the new memory.  pBuf is normally NULL.  If pBuf is not
-** NULL, it means that memory space has already been allocated and that
-** this routine should not allocate any new memory.  When pBuf is not
-** NULL simply return pBuf.  Only allocate new memory space when pBuf
-** is NULL.
-**
-** nByte is the number of bytes of space needed.
+/* An instance of this object describes bulk memory available for use
+** by subcomponents of a prepared statement.  Space is allocated out
+** of a ReusableSpace object by the allocSpace() routine below.
+*/
+struct ReusableSpace {
+  u8 *pSpace;          /* Available memory */
+  int nFree;           /* Bytes of available memory */
+  int nNeeded;         /* Total bytes that could not be allocated */
+};
+
+/* Try to allocate nByte bytes of 8-byte aligned bulk memory for pBuf
+** from the ReusableSpace object.  Return a pointer to the allocated
+** memory on success.  If insufficient memory is available in the
+** ReusableSpace object, increase the ReusableSpace.nNeeded
+** value by the amount needed and return NULL.
 **
-** *ppFrom points to available space and pEnd points to the end of the
-** available space.  When space is allocated, *ppFrom is advanced past
-** the end of the allocated space.
+** If pBuf is not initially NULL, that means that the memory has already
+** been allocated by a prior call to this routine, so just return a copy
+** of pBuf and leave ReusableSpace unchanged.
 **
-** *pnByte is a counter of the number of bytes of space that have failed
-** to allocate.  If there is insufficient space in *ppFrom to satisfy the
-** request, then increment *pnByte by the amount of the request.
+** This allocator is employed to repurpose unused slots at the end of the
+** opcode array of prepared state for other memory needs of the prepared
+** statement.
 */
 static void *allocSpace(
-  void *pBuf,          /* Where return pointer will be stored */
-  int nByte,           /* Number of bytes to allocate */
-  u8 **ppFrom,         /* IN/OUT: Allocate from *ppFrom */
-  u8 *pEnd,            /* Pointer to 1 byte past the end of *ppFrom buffer */
-  int *pnByte          /* If allocation cannot be made, increment *pnByte */
-){
-  assert( EIGHT_BYTE_ALIGNMENT(*ppFrom) );
-  if( pBuf ) return pBuf;
-  nByte = ROUND8(nByte);
-  if( &(*ppFrom)[nByte] <= pEnd ){
-    pBuf = (void*)*ppFrom;
-    *ppFrom += nByte;
-  }else{
-    *pnByte += nByte;
+  struct ReusableSpace *p,  /* Bulk memory available for allocation */
+  void *pBuf,               /* Pointer to a prior allocation */
+  int nByte                 /* Bytes of memory needed */
+){
+  assert( EIGHT_BYTE_ALIGNMENT(p->pSpace) );
+  if( pBuf==0 ){
+    nByte = ROUND8(nByte);
+    if( nByte <= p->nFree ){
+      p->nFree -= nByte;
+      pBuf = &p->pSpace[p->nFree];
+    }else{
+      p->nNeeded += nByte;
+    }
   }
+  assert( EIGHT_BYTE_ALIGNMENT(pBuf) );
   return pBuf;
 }
 
@@ -59596,14 +72171,13 @@ SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe *p){
   p->magic = VDBE_MAGIC_RUN;
 
 #ifdef SQLITE_DEBUG
-  for(i=1; i<p->nMem; i++){
+  for(i=0; i<p->nMem; i++){
     assert( p->aMem[i].db==p->db );
   }
 #endif
   p->pc = -1;
   p->rc = SQLITE_OK;
   p->errorAction = OE_Abort;
-  p->magic = VDBE_MAGIC_RUN;
   p->nChange = 0;
   p->cacheCtr = 1;
   p->minWriteFileFormat = 255;
@@ -59620,13 +72194,13 @@ SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe *p){
 /*
 ** Prepare a virtual machine for execution for the first time after
 ** creating the virtual machine.  This involves things such
-** as allocating stack space and initializing the program counter.
+** as allocating registers and initializing the program counter.
 ** After the VDBE has be prepped, it can be executed by one or more
 ** calls to sqlite3VdbeExec().  
 **
-** This function may be called exact once on a each virtual machine.
+** This function may be called exactly once on each virtual machine.
 ** After this routine is called the VM has been "packaged" and is ready
-** to run.  After this routine is called, futher calls to 
+** to run.  After this routine is called, further calls to 
 ** sqlite3VdbeAddOp() functions are prohibited.  This routine disconnects
 ** the Vdbe from the Parse object that helped generate it so that the
 ** the Vdbe becomes an independent entity and the Parse object can be
@@ -59644,75 +72218,80 @@ SQLITE_PRIVATE void sqlite3VdbeMakeReady(
   int nMem;                      /* Number of VM memory registers */
   int nCursor;                   /* Number of cursors required */
   int nArg;                      /* Number of arguments in subprograms */
+  int nOnce;                     /* Number of OP_Once instructions */
   int n;                         /* Loop counter */
-  u8 *zCsr;                      /* Memory available for allocation */
-  u8 *zEnd;                      /* First byte past allocated memory */
-  int nByte;                     /* How much extra memory is needed */
+  struct ReusableSpace x;        /* Reusable bulk memory */
 
   assert( p!=0 );
   assert( p->nOp>0 );
   assert( pParse!=0 );
   assert( p->magic==VDBE_MAGIC_INIT );
+  assert( pParse==p->pParse );
   db = p->db;
   assert( db->mallocFailed==0 );
   nVar = pParse->nVar;
   nMem = pParse->nMem;
   nCursor = pParse->nTab;
   nArg = pParse->nMaxArg;
+  nOnce = pParse->nOnce;
+  if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
   
-  /* For each cursor required, also allocate a memory cell. Memory
-  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
-  ** the vdbe program. Instead they are used to allocate space for
-  ** VdbeCursor/BtCursor structures. The blob of memory associated with 
-  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
-  ** stores the blob of memory associated with cursor 1, etc.
-  **
+  /* Each cursor uses a memory cell.  The first cursor (cursor 0) can
+  ** use aMem[0] which is not otherwise used by the VDBE program.  Allocate
+  ** space at the end of aMem[] for cursors 1 and greater.
   ** See also: allocateCursor().
   */
   nMem += nCursor;
+  if( nCursor==0 && nMem>0 ) nMem++;  /* Space for aMem[0] even if not used */
 
-  /* Allocate space for memory registers, SQL variables, VDBE cursors and 
-  ** an array to marshal SQL function arguments in.
+  /* Figure out how much reusable memory is available at the end of the
+  ** opcode array.  This extra memory will be reallocated for other elements
+  ** of the prepared statement.
   */
-  zCsr = (u8*)&p->aOp[p->nOp];       /* Memory avaliable for allocation */
-  zEnd = (u8*)&p->aOp[p->nOpAlloc];  /* First byte past end of zCsr[] */
+  n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode memory used */
+  x.pSpace = &((u8*)p->aOp)[n];               /* Unused opcode memory */
+  assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );
+  x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n);  /* Bytes of unused memory */
+  assert( x.nFree>=0 );
+  if( x.nFree>0 ){
+    memset(x.pSpace, 0, x.nFree);
+    assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );
+  }
 
   resolveP2Values(p, &nArg);
   p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
   if( pParse->explain && nMem<10 ){
     nMem = 10;
   }
-  memset(zCsr, 0, zEnd-zCsr);
-  zCsr += (zCsr - (u8*)0)&7;
-  assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
   p->expired = 0;
 
-  /* Memory for registers, parameters, cursor, etc, is allocated in two
-  ** passes.  On the first pass, we try to reuse unused space at the 
+  /* Memory for registers, parameters, cursor, etc, is allocated in one or two
+  ** passes.  On the first pass, we try to reuse unused memory at the 
   ** end of the opcode array.  If we are unable to satisfy all memory
   ** requirements by reusing the opcode array tail, then the second
-  ** pass will fill in the rest using a fresh allocation.  
+  ** pass will fill in the remainder using a fresh memory allocation.  
   **
   ** This two-pass approach that reuses as much memory as possible from
-  ** the leftover space at the end of the opcode array can significantly
+  ** the leftover memory at the end of the opcode array.  This can significantly
   ** reduce the amount of memory held by a prepared statement.
   */
   do {
-    nByte = 0;
-    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
-    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
-    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
-    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
-    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
-                          &zCsr, zEnd, &nByte);
-    if( nByte ){
-      p->pFree = sqlite3DbMallocZero(db, nByte);
-    }
-    zCsr = p->pFree;
-    zEnd = &zCsr[nByte];
-  }while( nByte && !db->mallocFailed );
-
-  p->nCursor = (u16)nCursor;
+    x.nNeeded = 0;
+    p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
+    p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
+    p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
+    p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
+    p->aOnceFlag = allocSpace(&x, p->aOnceFlag, nOnce);
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+    p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
+#endif
+    if( x.nNeeded==0 ) break;
+    x.pSpace = p->pFree = sqlite3DbMallocZero(db, x.nNeeded);
+    x.nFree = x.nNeeded;
+  }while( !db->mallocFailed );
+
+  p->nCursor = nCursor;
+  p->nOnceFlag = nOnce;
   if( p->aVar ){
     p->nVar = (ynVar)nVar;
     for(n=0; n<nVar; n++){
@@ -59720,16 +72299,14 @@ SQLITE_PRIVATE void sqlite3VdbeMakeReady(
       p->aVar[n].db = db;
     }
   }
-  if( p->azVar ){
-    p->nzVar = pParse->nzVar;
-    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
-    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
-  }
+  p->nzVar = pParse->nzVar;
+  p->azVar = pParse->azVar;
+  pParse->nzVar =  0;
+  pParse->azVar = 0;
   if( p->aMem ){
-    p->aMem--;                      /* aMem[] goes from 1..nMem */
-    p->nMem = nMem;                 /*       not from 0..nMem-1 */
-    for(n=1; n<=nMem; n++){
-      p->aMem[n].flags = MEM_Null;
+    p->nMem = nMem;
+    for(n=0; n<nMem; n++){
+      p->aMem[n].flags = MEM_Undefined;
       p->aMem[n].db = db;
     }
   }
@@ -59745,23 +72322,50 @@ SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
   if( pCx==0 ){
     return;
   }
-  sqlite3VdbeSorterClose(p->db, pCx);
-  if( pCx->pBt ){
-    sqlite3BtreeClose(pCx->pBt);
-    /* The pCx->pCursor will be close automatically, if it exists, by
-    ** the call above. */
-  }else if( pCx->pCursor ){
-    sqlite3BtreeCloseCursor(pCx->pCursor);
-  }
+  assert( pCx->pBt==0 || pCx->eCurType==CURTYPE_BTREE );
+  switch( pCx->eCurType ){
+    case CURTYPE_SORTER: {
+      sqlite3VdbeSorterClose(p->db, pCx);
+      break;
+    }
+    case CURTYPE_BTREE: {
+      if( pCx->pBt ){
+        sqlite3BtreeClose(pCx->pBt);
+        /* The pCx->pCursor will be close automatically, if it exists, by
+        ** the call above. */
+      }else{
+        assert( pCx->uc.pCursor!=0 );
+        sqlite3BtreeCloseCursor(pCx->uc.pCursor);
+      }
+      break;
+    }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  if( pCx->pVtabCursor ){
-    sqlite3_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
-    const sqlite3_module *pModule = pCx->pModule;
-    p->inVtabMethod = 1;
-    pModule->xClose(pVtabCursor);
-    p->inVtabMethod = 0;
-  }
+    case CURTYPE_VTAB: {
+      sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;
+      const sqlite3_module *pModule = pVCur->pVtab->pModule;
+      assert( pVCur->pVtab->nRef>0 );
+      pVCur->pVtab->nRef--;
+      pModule->xClose(pVCur);
+      break;
+    }
 #endif
+  }
+}
+
+/*
+** Close all cursors in the current frame.
+*/
+static void closeCursorsInFrame(Vdbe *p){
+  if( p->apCsr ){
+    int i;
+    for(i=0; i<p->nCursor; i++){
+      VdbeCursor *pC = p->apCsr[i];
+      if( pC ){
+        sqlite3VdbeFreeCursor(p, pC);
+        p->apCsr[i] = 0;
+      }
+    }
+  }
 }
 
 /*
@@ -59771,6 +72375,12 @@ SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
 */
 SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
   Vdbe *v = pFrame->v;
+  closeCursorsInFrame(v);
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  v->anExec = pFrame->anExec;
+#endif
+  v->aOnceFlag = pFrame->aOnceFlag;
+  v->nOnceFlag = pFrame->nOnceFlag;
   v->aOp = pFrame->aOp;
   v->nOp = pFrame->nOp;
   v->aMem = pFrame->aMem;
@@ -59779,6 +72389,10 @@ SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
   v->nCursor = pFrame->nCursor;
   v->db->lastRowid = pFrame->lastRowid;
   v->nChange = pFrame->nChange;
+  v->db->nChange = pFrame->nDbChange;
+  sqlite3VdbeDeleteAuxData(v->db, &v->pAuxData, -1, 0);
+  v->pAuxData = pFrame->pAuxData;
+  pFrame->pAuxData = 0;
   return pFrame->pc;
 }
 
@@ -59795,36 +72409,27 @@ static void closeAllCursors(Vdbe *p){
     VdbeFrame *pFrame;
     for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
     sqlite3VdbeFrameRestore(pFrame);
+    p->pFrame = 0;
+    p->nFrame = 0;
   }
-  p->pFrame = 0;
-  p->nFrame = 0;
-
-  if( p->apCsr ){
-    int i;
-    for(i=0; i<p->nCursor; i++){
-      VdbeCursor *pC = p->apCsr[i];
-      if( pC ){
-        sqlite3VdbeFreeCursor(p, pC);
-        p->apCsr[i] = 0;
-      }
-    }
-  }
+  assert( p->nFrame==0 );
+  closeCursorsInFrame(p);
   if( p->aMem ){
-    releaseMemArray(&p->aMem[1], p->nMem);
+    releaseMemArray(p->aMem, p->nMem);
   }
   while( p->pDelFrame ){
     VdbeFrame *pDel = p->pDelFrame;
     p->pDelFrame = pDel->pParent;
     sqlite3VdbeFrameDelete(pDel);
   }
+
+  /* Delete any auxdata allocations made by the VM */
+  if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p->db, &p->pAuxData, -1, 0);
+  assert( p->pAuxData==0 );
 }
 
 /*
-** Clean up the VM after execution.
-**
-** This routine will automatically close any cursors, lists, and/or
-** sorters that were left open.  It also deletes the values of
-** variables in the aVar[] array.
+** Clean up the VM after a single run.
 */
 static void Cleanup(Vdbe *p){
   sqlite3 *db = p->db;
@@ -59833,8 +72438,10 @@ static void Cleanup(Vdbe *p){
   /* Execute assert() statements to ensure that the Vdbe.apCsr[] and 
   ** Vdbe.aMem[] arrays have already been cleaned up.  */
   int i;
-  for(i=0; i<p->nCursor; i++) assert( p->apCsr==0 || p->apCsr[i]==0 );
-  for(i=1; i<=p->nMem; i++) assert( p->aMem==0 || p->aMem[i].flags==MEM_Null );
+  if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );
+  if( p->aMem ){
+    for(i=0; i<p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
+  }
 #endif
 
   sqlite3DbFree(db, p->zErrMsg);
@@ -59889,7 +72496,7 @@ SQLITE_PRIVATE int sqlite3VdbeSetColName(
   assert( var<COLNAME_N );
   if( p->db->mallocFailed ){
     assert( !zName || xDel!=SQLITE_DYNAMIC );
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   assert( p->aColName!=0 );
   pColName = &(p->aColName[idx+var*p->nResColumn]);
@@ -59906,7 +72513,9 @@ SQLITE_PRIVATE int sqlite3VdbeSetColName(
 */
 static int vdbeCommit(sqlite3 *db, Vdbe *p){
   int i;
-  int nTrans = 0;  /* Number of databases with an active write-transaction */
+  int nTrans = 0;  /* Number of databases with an active write-transaction
+                   ** that are candidates for a two-phase commit using a
+                   ** master-journal */
   int rc = SQLITE_OK;
   int needXcommit = 0;
 
@@ -59923,7 +72532,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   ** required, as an xSync() callback may add an attached database
   ** to the transaction.
   */
-  rc = sqlite3VtabSync(db, &p->zErrMsg);
+  rc = sqlite3VtabSync(db, p);
 
   /* This loop determines (a) if the commit hook should be invoked and
   ** (b) how many database files have open write transactions, not 
@@ -59934,9 +72543,29 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
     Btree *pBt = db->aDb[i].pBt;
     if( sqlite3BtreeIsInTrans(pBt) ){
+      /* Whether or not a database might need a master journal depends upon
+      ** its journal mode (among other things).  This matrix determines which
+      ** journal modes use a master journal and which do not */
+      static const u8 aMJNeeded[] = {
+        /* DELETE   */  1,
+        /* PERSIST   */ 1,
+        /* OFF       */ 0,
+        /* TRUNCATE  */ 1,
+        /* MEMORY    */ 0,
+        /* WAL       */ 0
+      };
+      Pager *pPager;   /* Pager associated with pBt */
       needXcommit = 1;
-      if( i!=1 ) nTrans++;
-      rc = sqlite3PagerExclusiveLock(sqlite3BtreePager(pBt));
+      sqlite3BtreeEnter(pBt);
+      pPager = sqlite3BtreePager(pBt);
+      if( db->aDb[i].safety_level!=PAGER_SYNCHRONOUS_OFF
+       && aMJNeeded[sqlite3PagerGetJournalMode(pPager)]
+      ){ 
+        assert( i!=1 );
+        nTrans++;
+      }
+      rc = sqlite3PagerExclusiveLock(pPager);
+      sqlite3BtreeLeave(pBt);
     }
   }
   if( rc!=SQLITE_OK ){
@@ -59947,7 +72576,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   if( needXcommit && db->xCommitCallback ){
     rc = db->xCommitCallback(db->pCommitArg);
     if( rc ){
-      return SQLITE_CONSTRAINT;
+      return SQLITE_CONSTRAINT_COMMITHOOK;
     }
   }
 
@@ -59988,27 +72617,41 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
 
   /* The complex case - There is a multi-file write-transaction active.
   ** This requires a master journal file to ensure the transaction is
-  ** committed atomicly.
+  ** committed atomically.
   */
 #ifndef SQLITE_OMIT_DISKIO
   else{
     sqlite3_vfs *pVfs = db->pVfs;
-    int needSync = 0;
     char *zMaster = 0;   /* File-name for the master journal */
     char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
     sqlite3_file *pMaster = 0;
     i64 offset = 0;
     int res;
+    int retryCount = 0;
+    int nMainFile;
 
     /* Select a master journal file name */
+    nMainFile = sqlite3Strlen30(zMainFile);
+    zMaster = sqlite3MPrintf(db, "%s-mjXXXXXX9XXz", zMainFile);
+    if( zMaster==0 ) return SQLITE_NOMEM_BKPT;
     do {
       u32 iRandom;
-      sqlite3DbFree(db, zMaster);
-      sqlite3_randomness(sizeof(iRandom), &iRandom);
-      zMaster = sqlite3MPrintf(db, "%s-mj%08X", zMainFile, iRandom&0x7fffffff);
-      if( !zMaster ){
-        return SQLITE_NOMEM;
+      if( retryCount ){
+        if( retryCount>100 ){
+          sqlite3_log(SQLITE_FULL, "MJ delete: %s", zMaster);
+          sqlite3OsDelete(pVfs, zMaster, 0);
+          break;
+        }else if( retryCount==1 ){
+          sqlite3_log(SQLITE_FULL, "MJ collide: %s", zMaster);
+        }
       }
+      retryCount++;
+      sqlite3_randomness(sizeof(iRandom), &iRandom);
+      sqlite3_snprintf(13, &zMaster[nMainFile], "-mj%06X9%02X",
+                               (iRandom>>8)&0xffffff, iRandom&0xff);
+      /* The antipenultimate character of the master journal name must
+      ** be "9" to avoid name collisions when using 8+3 filenames. */
+      assert( zMaster[sqlite3Strlen30(zMaster)-3]=='9' );
       sqlite3FileSuffix3(zMainFile, zMaster);
       rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);
     }while( rc==SQLITE_OK && res );
@@ -60038,9 +72681,6 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
           continue;  /* Ignore TEMP and :memory: databases */
         }
         assert( zFile[0]!=0 );
-        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
-          needSync = 1;
-        }
         rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
         offset += sqlite3Strlen30(zFile)+1;
         if( rc!=SQLITE_OK ){
@@ -60055,8 +72695,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
     /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
     ** flag is set this is not required.
     */
-    if( needSync 
-     && 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
+    if( 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
      && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))
     ){
       sqlite3OsCloseFree(pMaster);
@@ -60125,7 +72764,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
 }
 
 /* 
-** This routine checks that the sqlite3.activeVdbeCnt count variable
+** This routine checks that the sqlite3.nVdbeActive count variable
 ** matches the number of vdbe's in the list sqlite3.pVdbe that are
 ** currently active. An assertion fails if the two counts do not match.
 ** This is an internal self-check only - it is not an essential processing
@@ -60138,53 +72777,30 @@ static void checkActiveVdbeCnt(sqlite3 *db){
   Vdbe *p;
   int cnt = 0;
   int nWrite = 0;
+  int nRead = 0;
   p = db->pVdbe;
   while( p ){
-    if( p->magic==VDBE_MAGIC_RUN && p->pc>=0 ){
+    if( sqlite3_stmt_busy((sqlite3_stmt*)p) ){
       cnt++;
       if( p->readOnly==0 ) nWrite++;
+      if( p->bIsReader ) nRead++;
     }
     p = p->pNext;
   }
-  assert( cnt==db->activeVdbeCnt );
-  assert( nWrite==db->writeVdbeCnt );
+  assert( cnt==db->nVdbeActive );
+  assert( nWrite==db->nVdbeWrite );
+  assert( nRead==db->nVdbeRead );
 }
 #else
 #define checkActiveVdbeCnt(x)
 #endif
 
 /*
-** For every Btree that in database connection db which 
-** has been modified, "trip" or invalidate each cursor in
-** that Btree might have been modified so that the cursor
-** can never be used again.  This happens when a rollback
-*** occurs.  We have to trip all the other cursors, even
-** cursor from other VMs in different database connections,
-** so that none of them try to use the data at which they
-** were pointing and which now may have been changed due
-** to the rollback.
-**
-** Remember that a rollback can delete tables complete and
-** reorder rootpages.  So it is not sufficient just to save
-** the state of the cursor.  We have to invalidate the cursor
-** so that it is never used again.
-*/
-static void invalidateCursorsOnModifiedBtrees(sqlite3 *db){
-  int i;
-  for(i=0; i<db->nDb; i++){
-    Btree *p = db->aDb[i].pBt;
-    if( p && sqlite3BtreeIsInTrans(p) ){
-      sqlite3BtreeTripAllCursors(p, SQLITE_ABORT);
-    }
-  }
-}
-
-/*
 ** If the Vdbe passed as the first argument opened a statement-transaction,
 ** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
 ** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
 ** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
-** statement transaction is commtted.
+** statement transaction is committed.
 **
 ** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
 ** Otherwise SQLITE_OK.
@@ -60195,7 +72811,7 @@ SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
 
   /* If p->iStatement is greater than zero, then this Vdbe opened a 
   ** statement transaction that should be closed here. The only exception
-  ** is that an IO error may have occured, causing an emergency rollback.
+  ** is that an IO error may have occurred, causing an emergency rollback.
   ** In this case (db->nStatement==0), and there is nothing to do.
   */
   if( db->nStatement && p->iStatement ){
@@ -60238,6 +72854,7 @@ SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
     ** the statement transaction was opened.  */
     if( eOp==SAVEPOINT_ROLLBACK ){
       db->nDeferredCons = p->nStmtDefCons;
+      db->nDeferredImmCons = p->nStmtDefImmCons;
     }
   }
   return rc;
@@ -60250,16 +72867,18 @@ SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
 ** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.
 **
 ** If there are outstanding FK violations and this function returns 
-** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT and write
-** an error message to it. Then return SQLITE_ERROR.
+** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY
+** and write an error message to it. Then return SQLITE_ERROR.
 */
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 SQLITE_PRIVATE int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
   sqlite3 *db = p->db;
-  if( (deferred && db->nDeferredCons>0) || (!deferred && p->nFkConstraint>0) ){
-    p->rc = SQLITE_CONSTRAINT;
+  if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0) 
+   || (!deferred && p->nFkConstraint>0) 
+  ){
+    p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
     p->errorAction = OE_Abort;
-    sqlite3SetString(&p->zErrMsg, db, "foreign key constraint failed");
+    sqlite3VdbeError(p, "FOREIGN KEY constraint failed");
     return SQLITE_ERROR;
   }
   return SQLITE_OK;
@@ -60299,17 +72918,19 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
   ** one, or the complete transaction if there is no statement transaction.
   */
 
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
+  if( db->mallocFailed ){
+    p->rc = SQLITE_NOMEM_BKPT;
   }
+  if( p->aOnceFlag ) memset(p->aOnceFlag, 0, p->nOnceFlag);
   closeAllCursors(p);
   if( p->magic!=VDBE_MAGIC_RUN ){
     return SQLITE_OK;
   }
   checkActiveVdbeCnt(db);
 
-  /* No commit or rollback needed if the program never started */
-  if( p->pc>=0 ){
+  /* No commit or rollback needed if the program never started or if the
+  ** SQL statement does not read or write a database file.  */
+  if( p->pc>=0 && p->bIsReader ){
     int mrc;   /* Primary error code from p->rc */
     int eStatementOp = 0;
     int isSpecialError;            /* Set to true if a 'special' error */
@@ -60319,7 +72940,6 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
 
     /* Check for one of the special errors */
     mrc = p->rc & 0xff;
-    assert( p->rc!=SQLITE_IOERR_BLOCKED );  /* This error no longer exists */
     isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
                      || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;
     if( isSpecialError ){
@@ -60330,7 +72950,7 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
       **
       ** Even if the statement is read-only, it is important to perform
       ** a statement or transaction rollback operation. If the error 
-      ** occured while writing to the journal, sub-journal or database
+      ** occurred while writing to the journal, sub-journal or database
       ** file as part of an effort to free up cache space (see function
       ** pagerStress() in pager.c), the rollback is required to restore 
       ** the pager to a consistent state.
@@ -60342,10 +72962,10 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
           /* We are forced to roll back the active transaction. Before doing
           ** so, abort any other statements this handle currently has active.
           */
-          invalidateCursorsOnModifiedBtrees(db);
-          sqlite3RollbackAll(db);
+          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
           sqlite3CloseSavepoints(db);
           db->autoCommit = 1;
+          p->nChange = 0;
         }
       }
     }
@@ -60363,7 +72983,7 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
     */
     if( !sqlite3VtabInSync(db) 
      && db->autoCommit 
-     && db->writeVdbeCnt==(p->readOnly==0) 
+     && db->nVdbeWrite==(p->readOnly==0) 
     ){
       if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
         rc = sqlite3VdbeCheckFk(p, 1);
@@ -60372,7 +72992,7 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
             sqlite3VdbeLeave(p);
             return SQLITE_ERROR;
           }
-          rc = SQLITE_CONSTRAINT;
+          rc = SQLITE_CONSTRAINT_FOREIGNKEY;
         }else{ 
           /* The auto-commit flag is true, the vdbe program was successful 
           ** or hit an 'OR FAIL' constraint and there are no deferred foreign
@@ -60385,13 +73005,17 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
           return SQLITE_BUSY;
         }else if( rc!=SQLITE_OK ){
           p->rc = rc;
-          sqlite3RollbackAll(db);
+          sqlite3RollbackAll(db, SQLITE_OK);
+          p->nChange = 0;
         }else{
           db->nDeferredCons = 0;
+          db->nDeferredImmCons = 0;
+          db->flags &= ~SQLITE_DeferFKs;
           sqlite3CommitInternalChanges(db);
         }
       }else{
-        sqlite3RollbackAll(db);
+        sqlite3RollbackAll(db, SQLITE_OK);
+        p->nChange = 0;
       }
       db->nStatement = 0;
     }else if( eStatementOp==0 ){
@@ -60400,10 +73024,10 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
       }else if( p->errorAction==OE_Abort ){
         eStatementOp = SAVEPOINT_ROLLBACK;
       }else{
-        invalidateCursorsOnModifiedBtrees(db);
-        sqlite3RollbackAll(db);
+        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
         sqlite3CloseSavepoints(db);
         db->autoCommit = 1;
+        p->nChange = 0;
       }
     }
   
@@ -60416,15 +73040,15 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
     if( eStatementOp ){
       rc = sqlite3VdbeCloseStatement(p, eStatementOp);
       if( rc ){
-        if( p->rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT ){
+        if( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT ){
           p->rc = rc;
           sqlite3DbFree(db, p->zErrMsg);
           p->zErrMsg = 0;
         }
-        invalidateCursorsOnModifiedBtrees(db);
-        sqlite3RollbackAll(db);
+        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
         sqlite3CloseSavepoints(db);
         db->autoCommit = 1;
+        p->nChange = 0;
       }
     }
   
@@ -60439,12 +73063,6 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
       }
       p->nChange = 0;
     }
-  
-    /* Rollback or commit any schema changes that occurred. */
-    if( p->rc!=SQLITE_OK && db->flags&SQLITE_InternChanges ){
-      sqlite3ResetInternalSchema(db, -1);
-      db->flags = (db->flags | SQLITE_InternChanges);
-    }
 
     /* Release the locks */
     sqlite3VdbeLeave(p);
@@ -60452,16 +73070,17 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
 
   /* We have successfully halted and closed the VM.  Record this fact. */
   if( p->pc>=0 ){
-    db->activeVdbeCnt--;
-    if( !p->readOnly ){
-      db->writeVdbeCnt--;
-    }
-    assert( db->activeVdbeCnt>=db->writeVdbeCnt );
+    db->nVdbeActive--;
+    if( !p->readOnly ) db->nVdbeWrite--;
+    if( p->bIsReader ) db->nVdbeRead--;
+    assert( db->nVdbeActive>=db->nVdbeRead );
+    assert( db->nVdbeRead>=db->nVdbeWrite );
+    assert( db->nVdbeWrite>=0 );
   }
   p->magic = VDBE_MAGIC_HALT;
   checkActiveVdbeCnt(db);
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
+  if( db->mallocFailed ){
+    p->rc = SQLITE_NOMEM_BKPT;
   }
 
   /* If the auto-commit flag is set to true, then any locks that were held
@@ -60472,7 +73091,7 @@ SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){
     sqlite3ConnectionUnlocked(db);
   }
 
-  assert( db->activeVdbeCnt>0 || db->autoCommit==0 || db->nStatement==0 );
+  assert( db->nVdbeActive>0 || db->autoCommit==0 || db->nStatement==0 );
   return (p->rc==SQLITE_BUSY ? SQLITE_BUSY : SQLITE_OK);
 }
 
@@ -60497,18 +73116,40 @@ SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p){
   sqlite3 *db = p->db;
   int rc = p->rc;
   if( p->zErrMsg ){
-    u8 mallocFailed = db->mallocFailed;
+    db->bBenignMalloc++;
     sqlite3BeginBenignMalloc();
+    if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
     sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
     sqlite3EndBenignMalloc();
-    db->mallocFailed = mallocFailed;
+    db->bBenignMalloc--;
     db->errCode = rc;
   }else{
-    sqlite3Error(db, rc, 0);
+    sqlite3Error(db, rc);
   }
   return rc;
 }
 
+#ifdef SQLITE_ENABLE_SQLLOG
+/*
+** If an SQLITE_CONFIG_SQLLOG hook is registered and the VM has been run, 
+** invoke it.
+*/
+static void vdbeInvokeSqllog(Vdbe *v){
+  if( sqlite3GlobalConfig.xSqllog && v->rc==SQLITE_OK && v->zSql && v->pc>=0 ){
+    char *zExpanded = sqlite3VdbeExpandSql(v, v->zSql);
+    assert( v->db->init.busy==0 );
+    if( zExpanded ){
+      sqlite3GlobalConfig.xSqllog(
+          sqlite3GlobalConfig.pSqllogArg, v->db, zExpanded, 1
+      );
+      sqlite3DbFree(v->db, zExpanded);
+    }
+  }
+}
+#else
+# define vdbeInvokeSqllog(x)
+#endif
+
 /*
 ** Clean up a VDBE after execution but do not delete the VDBE just yet.
 ** Write any error messages into *pzErrMsg.  Return the result code.
@@ -60536,6 +73177,7 @@ SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe *p){
   ** instructions yet, leave the main database error information unchanged.
   */
   if( p->pc>=0 ){
+    vdbeInvokeSqllog(p);
     sqlite3VdbeTransferError(p);
     sqlite3DbFree(db, p->zErrMsg);
     p->zErrMsg = 0;
@@ -60545,8 +73187,7 @@ SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe *p){
     ** to sqlite3_step(). For consistency (since sqlite3_step() was
     ** called), set the database error in this case as well.
     */
-    sqlite3Error(db, p->rc, 0);
-    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
+    sqlite3ErrorWithMsg(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
     sqlite3DbFree(db, p->zErrMsg);
     p->zErrMsg = 0;
   }
@@ -60567,18 +73208,31 @@ SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe *p){
         fprintf(out, "%02x", p->aOp[i].opcode);
       }
       fprintf(out, "\n");
+      if( p->zSql ){
+        char c, pc = 0;
+        fprintf(out, "-- ");
+        for(i=0; (c = p->zSql[i])!=0; i++){
+          if( pc=='\n' ) fprintf(out, "-- ");
+          putc(c, out);
+          pc = c;
+        }
+        if( pc!='\n' ) fprintf(out, "\n");
+      }
       for(i=0; i<p->nOp; i++){
-        fprintf(out, "%6d %10lld %8lld ",
+        char zHdr[100];
+        sqlite3_snprintf(sizeof(zHdr), zHdr, "%6u %12llu %8llu ",
            p->aOp[i].cnt,
            p->aOp[i].cycles,
            p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
         );
+        fprintf(out, "%s", zHdr);
         sqlite3VdbePrintOp(out, i, &p->aOp[i]);
       }
       fclose(out);
     }
   }
 #endif
+  p->iCurrentTime = 0;
   p->magic = VDBE_MAGIC_INIT;
   return p->rc & db->errMask;
 }
@@ -60598,31 +73252,48 @@ SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe *p){
 }
 
 /*
-** Call the destructor for each auxdata entry in pVdbeFunc for which
-** the corresponding bit in mask is clear.  Auxdata entries beyond 31
-** are always destroyed.  To destroy all auxdata entries, call this
-** routine with mask==0.
+** If parameter iOp is less than zero, then invoke the destructor for
+** all auxiliary data pointers currently cached by the VM passed as
+** the first argument.
+**
+** Or, if iOp is greater than or equal to zero, then the destructor is
+** only invoked for those auxiliary data pointers created by the user 
+** function invoked by the OP_Function opcode at instruction iOp of 
+** VM pVdbe, and only then if:
+**
+**    * the associated function parameter is the 32nd or later (counting
+**      from left to right), or
+**
+**    * the corresponding bit in argument mask is clear (where the first
+**      function parameter corresponds to bit 0 etc.).
 */
-SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(VdbeFunc *pVdbeFunc, int mask){
-  int i;
-  for(i=0; i<pVdbeFunc->nAux; i++){
-    struct AuxData *pAux = &pVdbeFunc->apAux[i];
-    if( (i>31 || !(mask&(((u32)1)<<i))) && pAux->pAux ){
+SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3 *db, AuxData **pp, int iOp, int mask){
+  while( *pp ){
+    AuxData *pAux = *pp;
+    if( (iOp<0)
+     || (pAux->iOp==iOp && (pAux->iArg>31 || !(mask & MASKBIT32(pAux->iArg))))
+    ){
+      testcase( pAux->iArg==31 );
       if( pAux->xDelete ){
         pAux->xDelete(pAux->pAux);
       }
-      pAux->pAux = 0;
+      *pp = pAux->pNext;
+      sqlite3DbFree(db, pAux);
+    }else{
+      pp= &pAux->pNext;
     }
   }
 }
 
 /*
-** Free all memory associated with the Vdbe passed as the second argument.
+** Free all memory associated with the Vdbe passed as the second argument,
+** except for object itself, which is preserved.
+**
 ** The difference between this function and sqlite3VdbeDelete() is that
 ** VdbeDelete() also unlinks the Vdbe from the list of VMs associated with
-** the database connection.
+** the database connection and frees the object itself.
 */
-SQLITE_PRIVATE void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){
+SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
   SubProgram *pSub, *pNext;
   int i;
   assert( p->db==0 || p->db==db );
@@ -60634,12 +73305,17 @@ SQLITE_PRIVATE void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){
     sqlite3DbFree(db, pSub);
   }
   for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
+  sqlite3DbFree(db, p->azVar);
   vdbeFreeOpArray(db, p->aOp, p->nOp);
-  sqlite3DbFree(db, p->aLabel);
   sqlite3DbFree(db, p->aColName);
   sqlite3DbFree(db, p->zSql);
   sqlite3DbFree(db, p->pFree);
-  sqlite3DbFree(db, p);
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  for(i=0; i<p->nScan; i++){
+    sqlite3DbFree(db, p->aScan[i].zName);
+  }
+  sqlite3DbFree(db, p->aScan);
+#endif
 }
 
 /*
@@ -60650,6 +73326,8 @@ SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe *p){
 
   if( NEVER(p==0) ) return;
   db = p->db;
+  assert( sqlite3_mutex_held(db->mutex) );
+  sqlite3VdbeClearObject(db, p);
   if( p->pPrev ){
     p->pPrev->pNext = p->pNext;
   }else{
@@ -60661,7 +73339,61 @@ SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe *p){
   }
   p->magic = VDBE_MAGIC_DEAD;
   p->db = 0;
-  sqlite3VdbeDeleteObject(db, p);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** The cursor "p" has a pending seek operation that has not yet been
+** carried out.  Seek the cursor now.  If an error occurs, return
+** the appropriate error code.
+*/
+static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
+  int res, rc;
+#ifdef SQLITE_TEST
+  extern int sqlite3_search_count;
+#endif
+  assert( p->deferredMoveto );
+  assert( p->isTable );
+  assert( p->eCurType==CURTYPE_BTREE );
+  rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);
+  if( rc ) return rc;
+  if( res!=0 ) return SQLITE_CORRUPT_BKPT;
+#ifdef SQLITE_TEST
+  sqlite3_search_count++;
+#endif
+  p->deferredMoveto = 0;
+  p->cacheStatus = CACHE_STALE;
+  return SQLITE_OK;
+}
+
+/*
+** Something has moved cursor "p" out of place.  Maybe the row it was
+** pointed to was deleted out from under it.  Or maybe the btree was
+** rebalanced.  Whatever the cause, try to restore "p" to the place it
+** is supposed to be pointing.  If the row was deleted out from under the
+** cursor, set the cursor to point to a NULL row.
+*/
+static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
+  int isDifferentRow, rc;
+  assert( p->eCurType==CURTYPE_BTREE );
+  assert( p->uc.pCursor!=0 );
+  assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );
+  rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);
+  p->cacheStatus = CACHE_STALE;
+  if( isDifferentRow ) p->nullRow = 1;
+  return rc;
+}
+
+/*
+** Check to ensure that the cursor is valid.  Restore the cursor
+** if need be.  Return any I/O error from the restore operation.
+*/
+SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor *p){
+  assert( p->eCurType==CURTYPE_BTREE );
+  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
+    return handleMovedCursor(p);
+  }
+  return SQLITE_OK;
 }
 
 /*
@@ -60677,30 +73409,20 @@ SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe *p){
 ** If the cursor is already pointing to the correct row and that row has
 ** not been deleted out from under the cursor, then this routine is a no-op.
 */
-SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
-  if( p->deferredMoveto ){
-    int res, rc;
-#ifdef SQLITE_TEST
-    extern int sqlite3_search_count;
-#endif
-    assert( p->isTable );
-    rc = sqlite3BtreeMovetoUnpacked(p->pCursor, 0, p->movetoTarget, 0, &res);
-    if( rc ) return rc;
-    p->lastRowid = p->movetoTarget;
-    if( res!=0 ) return SQLITE_CORRUPT_BKPT;
-    p->rowidIsValid = 1;
-#ifdef SQLITE_TEST
-    sqlite3_search_count++;
-#endif
-    p->deferredMoveto = 0;
-    p->cacheStatus = CACHE_STALE;
-  }else if( ALWAYS(p->pCursor) ){
-    int hasMoved;
-    int rc = sqlite3BtreeCursorHasMoved(p->pCursor, &hasMoved);
-    if( rc ) return rc;
-    if( hasMoved ){
-      p->cacheStatus = CACHE_STALE;
-      p->nullRow = 1;
+SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
+  VdbeCursor *p = *pp;
+  if( p->eCurType==CURTYPE_BTREE ){
+    if( p->deferredMoveto ){
+      int iMap;
+      if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){
+        *pp = p->pAltCursor;
+        *piCol = iMap - 1;
+        return SQLITE_OK;
+      }
+      return handleDeferredMoveto(p);
+    }
+    if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
+      return handleMovedCursor(p);
     }
   }
   return SQLITE_OK;
@@ -60724,7 +73446,7 @@ SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
 ** the blob of data that it corresponds to. In a table record, all serial
 ** types are stored at the start of the record, and the blobs of data at
 ** the end. Hence these functions allow the caller to handle the
-** serial-type and data blob seperately.
+** serial-type and data blob separately.
 **
 ** The following table describes the various storage classes for data:
 **
@@ -60751,11 +73473,13 @@ SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor *p){
 /*
 ** Return the serial-type for the value stored in pMem.
 */
-SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
+SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
   int flags = pMem->flags;
-  int n;
+  u32 n;
 
+  assert( pLen!=0 );
   if( flags&MEM_Null ){
+    *pLen = 0;
     return 0;
   }
   if( flags&MEM_Int ){
@@ -60763,46 +73487,77 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
 #   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
     i64 i = pMem->u.i;
     u64 u;
-    if( file_format>=4 && (i&1)==i ){
-      return 8+(u32)i;
-    }
     if( i<0 ){
-      if( i<(-MAX_6BYTE) ) return 6;
-      /* Previous test prevents:  u = -(-9223372036854775808) */
-      u = -i;
+      u = ~i;
     }else{
       u = i;
     }
-    if( u<=127 ) return 1;
-    if( u<=32767 ) return 2;
-    if( u<=8388607 ) return 3;
-    if( u<=2147483647 ) return 4;
-    if( u<=MAX_6BYTE ) return 5;
+    if( u<=127 ){
+      if( (i&1)==i && file_format>=4 ){
+        *pLen = 0;
+        return 8+(u32)u;
+      }else{
+        *pLen = 1;
+        return 1;
+      }
+    }
+    if( u<=32767 ){ *pLen = 2; return 2; }
+    if( u<=8388607 ){ *pLen = 3; return 3; }
+    if( u<=2147483647 ){ *pLen = 4; return 4; }
+    if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }
+    *pLen = 8;
     return 6;
   }
   if( flags&MEM_Real ){
+    *pLen = 8;
     return 7;
   }
   assert( pMem->db->mallocFailed || flags&(MEM_Str|MEM_Blob) );
-  n = pMem->n;
+  assert( pMem->n>=0 );
+  n = (u32)pMem->n;
   if( flags & MEM_Zero ){
     n += pMem->u.nZero;
   }
-  assert( n>=0 );
+  *pLen = n;
   return ((n*2) + 12 + ((flags&MEM_Str)!=0));
 }
 
 /*
+** The sizes for serial types less than 128
+*/
+static const u8 sqlite3SmallTypeSizes[] = {
+        /*  0   1   2   3   4   5   6   7   8   9 */   
+/*   0 */   0,  1,  2,  3,  4,  6,  8,  8,  0,  0,
+/*  10 */   0,  0,  0,  0,  1,  1,  2,  2,  3,  3,
+/*  20 */   4,  4,  5,  5,  6,  6,  7,  7,  8,  8,
+/*  30 */   9,  9, 10, 10, 11, 11, 12, 12, 13, 13,
+/*  40 */  14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
+/*  50 */  19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
+/*  60 */  24, 24, 25, 25, 26, 26, 27, 27, 28, 28,
+/*  70 */  29, 29, 30, 30, 31, 31, 32, 32, 33, 33,
+/*  80 */  34, 34, 35, 35, 36, 36, 37, 37, 38, 38,
+/*  90 */  39, 39, 40, 40, 41, 41, 42, 42, 43, 43,
+/* 100 */  44, 44, 45, 45, 46, 46, 47, 47, 48, 48,
+/* 110 */  49, 49, 50, 50, 51, 51, 52, 52, 53, 53,
+/* 120 */  54, 54, 55, 55, 56, 56, 57, 57
+};
+
+/*
 ** Return the length of the data corresponding to the supplied serial-type.
 */
 SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
-  if( serial_type>=12 ){
+  if( serial_type>=128 ){
     return (serial_type-12)/2;
   }else{
-    static const u8 aSize[] = { 0, 1, 2, 3, 4, 6, 8, 8, 0, 0, 0, 0 };
-    return aSize[serial_type];
+    assert( serial_type<12 
+            || sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );
+    return sqlite3SmallTypeSizes[serial_type];
   }
 }
+SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){
+  assert( serial_type<128 );
+  return sqlite3SmallTypeSizes[serial_type];  
+}
 
 /*
 ** If we are on an architecture with mixed-endian floating 
@@ -60862,21 +73617,15 @@ static u64 floatSwap(u64 in){
 ** buf. It is assumed that the caller has allocated sufficient space.
 ** Return the number of bytes written.
 **
-** nBuf is the amount of space left in buf[].  nBuf must always be
-** large enough to hold the entire field.  Except, if the field is
-** a blob with a zero-filled tail, then buf[] might be just the right
-** size to hold everything except for the zero-filled tail.  If buf[]
-** is only big enough to hold the non-zero prefix, then only write that
-** prefix into buf[].  But if buf[] is large enough to hold both the
-** prefix and the tail then write the prefix and set the tail to all
-** zeros.
+** nBuf is the amount of space left in buf[].  The caller is responsible
+** for allocating enough space to buf[] to hold the entire field, exclusive
+** of the pMem->u.nZero bytes for a MEM_Zero value.
 **
 ** Return the number of bytes actually written into buf[].  The number
 ** of bytes in the zero-filled tail is included in the return value only
 ** if those bytes were zeroed in buf[].
 */ 
-SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
-  u32 serial_type = sqlite3VdbeSerialType(pMem, file_format);
+SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
   u32 len;
 
   /* Integer and Real */
@@ -60884,18 +73633,18 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_f
     u64 v;
     u32 i;
     if( serial_type==7 ){
-      assert( sizeof(v)==sizeof(pMem->r) );
-      memcpy(&v, &pMem->r, sizeof(v));
+      assert( sizeof(v)==sizeof(pMem->u.r) );
+      memcpy(&v, &pMem->u.r, sizeof(v));
       swapMixedEndianFloat(v);
     }else{
       v = pMem->u.i;
     }
-    len = i = sqlite3VdbeSerialTypeLen(serial_type);
-    assert( len<=(u32)nBuf );
-    while( i-- ){
-      buf[i] = (u8)(v&0xFF);
+    len = i = sqlite3SmallTypeSizes[serial_type];
+    assert( i>0 );
+    do{
+      buf[--i] = (u8)(v&0xFF);
       v >>= 8;
-    }
+    }while( i );
     return len;
   }
 
@@ -60903,17 +73652,8 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_f
   if( serial_type>=12 ){
     assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
              == (int)sqlite3VdbeSerialTypeLen(serial_type) );
-    assert( pMem->n<=nBuf );
     len = pMem->n;
-    memcpy(buf, pMem->z, len);
-    if( pMem->flags & MEM_Zero ){
-      len += pMem->u.nZero;
-      assert( nBuf>=0 );
-      if( len > (u32)nBuf ){
-        len = (u32)nBuf;
-      }
-      memset(&buf[pMem->n], 0, len-pMem->n);
-    }
+    if( len>0 ) memcpy(buf, pMem->z, len);
     return len;
   }
 
@@ -60921,10 +73661,60 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_f
   return 0;
 }
 
+/* Input "x" is a sequence of unsigned characters that represent a
+** big-endian integer.  Return the equivalent native integer
+*/
+#define ONE_BYTE_INT(x)    ((i8)(x)[0])
+#define TWO_BYTE_INT(x)    (256*(i8)((x)[0])|(x)[1])
+#define THREE_BYTE_INT(x)  (65536*(i8)((x)[0])|((x)[1]<<8)|(x)[2])
+#define FOUR_BYTE_UINT(x)  (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
+#define FOUR_BYTE_INT(x) (16777216*(i8)((x)[0])|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
+
 /*
 ** Deserialize the data blob pointed to by buf as serial type serial_type
 ** and store the result in pMem.  Return the number of bytes read.
+**
+** This function is implemented as two separate routines for performance.
+** The few cases that require local variables are broken out into a separate
+** routine so that in most cases the overhead of moving the stack pointer
+** is avoided.
 */ 
+static u32 SQLITE_NOINLINE serialGet(
+  const unsigned char *buf,     /* Buffer to deserialize from */
+  u32 serial_type,              /* Serial type to deserialize */
+  Mem *pMem                     /* Memory cell to write value into */
+){
+  u64 x = FOUR_BYTE_UINT(buf);
+  u32 y = FOUR_BYTE_UINT(buf+4);
+  x = (x<<32) + y;
+  if( serial_type==6 ){
+    /* EVIDENCE-OF: R-29851-52272 Value is a big-endian 64-bit
+    ** twos-complement integer. */
+    pMem->u.i = *(i64*)&x;
+    pMem->flags = MEM_Int;
+    testcase( pMem->u.i<0 );
+  }else{
+    /* EVIDENCE-OF: R-57343-49114 Value is a big-endian IEEE 754-2008 64-bit
+    ** floating point number. */
+#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
+    /* Verify that integers and floating point values use the same
+    ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
+    ** defined that 64-bit floating point values really are mixed
+    ** endian.
+    */
+    static const u64 t1 = ((u64)0x3ff00000)<<32;
+    static const double r1 = 1.0;
+    u64 t2 = t1;
+    swapMixedEndianFloat(t2);
+    assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
+#endif
+    assert( sizeof(x)==8 && sizeof(pMem->u.r)==8 );
+    swapMixedEndianFloat(x);
+    memcpy(&pMem->u.r, &x, sizeof(x));
+    pMem->flags = sqlite3IsNaN(pMem->u.r) ? MEM_Null : MEM_Real;
+  }
+  return 8;
+}
 SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(
   const unsigned char *buf,     /* Buffer to deserialize from */
   u32 serial_type,              /* Serial type to deserialize */
@@ -60933,91 +73723,83 @@ SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(
   switch( serial_type ){
     case 10:   /* Reserved for future use */
     case 11:   /* Reserved for future use */
-    case 0: {  /* NULL */
+    case 0: {  /* Null */
+      /* EVIDENCE-OF: R-24078-09375 Value is a NULL. */
       pMem->flags = MEM_Null;
       break;
     }
-    case 1: { /* 1-byte signed integer */
-      pMem->u.i = (signed char)buf[0];
+    case 1: {
+      /* EVIDENCE-OF: R-44885-25196 Value is an 8-bit twos-complement
+      ** integer. */
+      pMem->u.i = ONE_BYTE_INT(buf);
       pMem->flags = MEM_Int;
+      testcase( pMem->u.i<0 );
       return 1;
     }
     case 2: { /* 2-byte signed integer */
-      pMem->u.i = (((signed char)buf[0])<<8) | buf[1];
+      /* EVIDENCE-OF: R-49794-35026 Value is a big-endian 16-bit
+      ** twos-complement integer. */
+      pMem->u.i = TWO_BYTE_INT(buf);
       pMem->flags = MEM_Int;
+      testcase( pMem->u.i<0 );
       return 2;
     }
     case 3: { /* 3-byte signed integer */
-      pMem->u.i = (((signed char)buf[0])<<16) | (buf[1]<<8) | buf[2];
+      /* EVIDENCE-OF: R-37839-54301 Value is a big-endian 24-bit
+      ** twos-complement integer. */
+      pMem->u.i = THREE_BYTE_INT(buf);
       pMem->flags = MEM_Int;
+      testcase( pMem->u.i<0 );
       return 3;
     }
     case 4: { /* 4-byte signed integer */
-      pMem->u.i = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
+      /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit
+      ** twos-complement integer. */
+      pMem->u.i = FOUR_BYTE_INT(buf);
+#ifdef __HP_cc 
+      /* Work around a sign-extension bug in the HP compiler for HP/UX */
+      if( buf[0]&0x80 ) pMem->u.i |= 0xffffffff80000000LL;
+#endif
       pMem->flags = MEM_Int;
+      testcase( pMem->u.i<0 );
       return 4;
     }
     case 5: { /* 6-byte signed integer */
-      u64 x = (((signed char)buf[0])<<8) | buf[1];
-      u32 y = (buf[2]<<24) | (buf[3]<<16) | (buf[4]<<8) | buf[5];
-      x = (x<<32) | y;
-      pMem->u.i = *(i64*)&x;
+      /* EVIDENCE-OF: R-50385-09674 Value is a big-endian 48-bit
+      ** twos-complement integer. */
+      pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
       pMem->flags = MEM_Int;
+      testcase( pMem->u.i<0 );
       return 6;
     }
     case 6:   /* 8-byte signed integer */
     case 7: { /* IEEE floating point */
-      u64 x;
-      u32 y;
-#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
-      /* Verify that integers and floating point values use the same
-      ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
-      ** defined that 64-bit floating point values really are mixed
-      ** endian.
-      */
-      static const u64 t1 = ((u64)0x3ff00000)<<32;
-      static const double r1 = 1.0;
-      u64 t2 = t1;
-      swapMixedEndianFloat(t2);
-      assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
-#endif
-
-      x = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
-      y = (buf[4]<<24) | (buf[5]<<16) | (buf[6]<<8) | buf[7];
-      x = (x<<32) | y;
-      if( serial_type==6 ){
-        pMem->u.i = *(i64*)&x;
-        pMem->flags = MEM_Int;
-      }else{
-        assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
-        swapMixedEndianFloat(x);
-        memcpy(&pMem->r, &x, sizeof(x));
-        pMem->flags = sqlite3IsNaN(pMem->r) ? MEM_Null : MEM_Real;
-      }
-      return 8;
+      /* These use local variables, so do them in a separate routine
+      ** to avoid having to move the frame pointer in the common case */
+      return serialGet(buf,serial_type,pMem);
     }
     case 8:    /* Integer 0 */
     case 9: {  /* Integer 1 */
+      /* EVIDENCE-OF: R-12976-22893 Value is the integer 0. */
+      /* EVIDENCE-OF: R-18143-12121 Value is the integer 1. */
       pMem->u.i = serial_type-8;
       pMem->flags = MEM_Int;
       return 0;
     }
     default: {
-      u32 len = (serial_type-12)/2;
+      /* EVIDENCE-OF: R-14606-31564 Value is a BLOB that is (N-12)/2 bytes in
+      ** length.
+      ** EVIDENCE-OF: R-28401-00140 Value is a string in the text encoding and
+      ** (N-13)/2 bytes in length. */
+      static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
       pMem->z = (char *)buf;
-      pMem->n = len;
-      pMem->xDel = 0;
-      if( serial_type&0x01 ){
-        pMem->flags = MEM_Str | MEM_Ephem;
-      }else{
-        pMem->flags = MEM_Blob | MEM_Ephem;
-      }
-      return len;
+      pMem->n = (serial_type-12)/2;
+      pMem->flags = aFlag[serial_type&1];
+      return pMem->n;
     }
   }
   return 0;
 }
-
 /*
 ** This routine is used to allocate sufficient space for an UnpackedRecord
 ** structure large enough to be used with sqlite3VdbeRecordUnpack() if
@@ -61058,6 +73840,7 @@ SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(
   }
 
   p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
+  assert( pKeyInfo->aSortOrder!=0 );
   p->pKeyInfo = pKeyInfo;
   p->nField = pKeyInfo->nField + 1;
   return p;
@@ -61081,72 +73864,60 @@ SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(
   u32 szHdr;
   Mem *pMem = p->aMem;
 
-  p->flags = 0;
+  p->default_rc = 0;
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
   idx = getVarint32(aKey, szHdr);
   d = szHdr;
   u = 0;
-  while( idx<szHdr && u<p->nField && d<=nKey ){
+  while( idx<szHdr && d<=nKey ){
     u32 serial_type;
 
     idx += getVarint32(&aKey[idx], serial_type);
     pMem->enc = pKeyInfo->enc;
     pMem->db = pKeyInfo->db;
     /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
-    pMem->zMalloc = 0;
+    pMem->szMalloc = 0;
+    pMem->z = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
-    u++;
+    if( (++u)>=p->nField ) break;
   }
   assert( u<=pKeyInfo->nField + 1 );
   p->nField = u;
 }
 
+#if SQLITE_DEBUG
 /*
-** This function compares the two table rows or index records
-** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero
-** or positive integer if key1 is less than, equal to or 
-** greater than key2.  The {nKey1, pKey1} key must be a blob
-** created by th OP_MakeRecord opcode of the VDBE.  The pPKey2
-** key must be a parsed key such as obtained from
-** sqlite3VdbeParseRecord.
+** This function compares two index or table record keys in the same way
+** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),
+** this function deserializes and compares values using the
+** sqlite3VdbeSerialGet() and sqlite3MemCompare() functions. It is used
+** in assert() statements to ensure that the optimized code in
+** sqlite3VdbeRecordCompare() returns results with these two primitives.
 **
-** Key1 and Key2 do not have to contain the same number of fields.
-** The key with fewer fields is usually compares less than the 
-** longer key.  However if the UNPACKED_INCRKEY flags in pPKey2 is set
-** and the common prefixes are equal, then key1 is less than key2.
-** Or if the UNPACKED_MATCH_PREFIX flag is set and the prefixes are
-** equal, then the keys are considered to be equal and
-** the parts beyond the common prefix are ignored.
-**
-** If the UNPACKED_IGNORE_ROWID flag is set, then the last byte of
-** the header of pKey1 is ignored.  It is assumed that pKey1 is
-** an index key, and thus ends with a rowid value.  The last byte
-** of the header will therefore be the serial type of the rowid:
-** one of 1, 2, 3, 4, 5, 6, 8, or 9 - the integer serial types.
-** The serial type of the final rowid will always be a single byte.
-** By ignoring this last byte of the header, we force the comparison
-** to ignore the rowid at the end of key1.
+** Return true if the result of comparison is equivalent to desiredResult.
+** Return false if there is a disagreement.
 */
-SQLITE_PRIVATE int sqlite3VdbeRecordCompare(
+static int vdbeRecordCompareDebug(
   int nKey1, const void *pKey1, /* Left key */
-  UnpackedRecord *pPKey2        /* Right key */
+  const UnpackedRecord *pPKey2, /* Right key */
+  int desiredResult             /* Correct answer */
 ){
-  int d1;            /* Offset into aKey[] of next data element */
+  u32 d1;            /* Offset into aKey[] of next data element */
   u32 idx1;          /* Offset into aKey[] of next header element */
   u32 szHdr1;        /* Number of bytes in header */
   int i = 0;
-  int nField;
   int rc = 0;
   const unsigned char *aKey1 = (const unsigned char *)pKey1;
   KeyInfo *pKeyInfo;
   Mem mem1;
 
   pKeyInfo = pPKey2->pKeyInfo;
+  if( pKeyInfo->db==0 ) return 1;
   mem1.enc = pKeyInfo->enc;
   mem1.db = pKeyInfo->db;
   /* mem1.flags = 0;  // Will be initialized by sqlite3VdbeSerialGet() */
-  VVA_ONLY( mem1.zMalloc = 0; ) /* Only needed by assert() statements */
+  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
 
   /* Compilers may complain that mem1.u.i is potentially uninitialized.
   ** We could initialize it, as shown here, to silence those complaints.
@@ -61158,17 +73929,29 @@ SQLITE_PRIVATE int sqlite3VdbeRecordCompare(
   /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */
   
   idx1 = getVarint32(aKey1, szHdr1);
+  if( szHdr1>98307 ) return SQLITE_CORRUPT;
   d1 = szHdr1;
-  if( pPKey2->flags & UNPACKED_IGNORE_ROWID ){
-    szHdr1--;
-  }
-  nField = pKeyInfo->nField;
-  while( idx1<szHdr1 && i<pPKey2->nField ){
+  assert( pKeyInfo->nField+pKeyInfo->nXField>=pPKey2->nField || CORRUPT_DB );
+  assert( pKeyInfo->aSortOrder!=0 );
+  assert( pKeyInfo->nField>0 );
+  assert( idx1<=szHdr1 || CORRUPT_DB );
+  do{
     u32 serial_type1;
 
     /* Read the serial types for the next element in each key. */
     idx1 += getVarint32( aKey1+idx1, serial_type1 );
-    if( d1>=nKey1 && sqlite3VdbeSerialTypeLen(serial_type1)>0 ) break;
+
+    /* Verify that there is enough key space remaining to avoid
+    ** a buffer overread.  The "d1+serial_type1+2" subexpression will
+    ** always be greater than or equal to the amount of required key space.
+    ** Use that approximation to avoid the more expensive call to
+    ** sqlite3VdbeSerialTypeLen() in the common case.
+    */
+    if( d1+serial_type1+2>(u32)nKey1
+     && d1+sqlite3VdbeSerialTypeLen(serial_type1)>(u32)nKey1 
+    ){
+      break;
+    }
 
     /* Extract the values to be compared.
     */
@@ -61176,58 +73959,689 @@ SQLITE_PRIVATE int sqlite3VdbeRecordCompare(
 
     /* Do the comparison
     */
-    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],
-                           i<nField ? pKeyInfo->aColl[i] : 0);
+    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i], pKeyInfo->aColl[i]);
     if( rc!=0 ){
-      assert( mem1.zMalloc==0 );  /* See comment below */
-
-      /* Invert the result if we are using DESC sort order. */
-      if( pKeyInfo->aSortOrder && i<nField && pKeyInfo->aSortOrder[i] ){
-        rc = -rc;
+      assert( mem1.szMalloc==0 );  /* See comment below */
+      if( pKeyInfo->aSortOrder[i] ){
+        rc = -rc;  /* Invert the result for DESC sort order. */
       }
-    
-      /* If the PREFIX_SEARCH flag is set and all fields except the final
-      ** rowid field were equal, then clear the PREFIX_SEARCH flag and set 
-      ** pPKey2->rowid to the value of the rowid field in (pKey1, nKey1).
-      ** This is used by the OP_IsUnique opcode.
-      */
-      if( (pPKey2->flags & UNPACKED_PREFIX_SEARCH) && i==(pPKey2->nField-1) ){
-        assert( idx1==szHdr1 && rc );
-        assert( mem1.flags & MEM_Int );
-        pPKey2->flags &= ~UNPACKED_PREFIX_SEARCH;
-        pPKey2->rowid = mem1.u.i;
-      }
-    
-      return rc;
+      goto debugCompareEnd;
     }
     i++;
-  }
+  }while( idx1<szHdr1 && i<pPKey2->nField );
 
   /* No memory allocation is ever used on mem1.  Prove this using
   ** the following assert().  If the assert() fails, it indicates a
   ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).
   */
-  assert( mem1.zMalloc==0 );
+  assert( mem1.szMalloc==0 );
 
   /* rc==0 here means that one of the keys ran out of fields and
-  ** all the fields up to that point were equal. If the UNPACKED_INCRKEY
-  ** flag is set, then break the tie by treating key2 as larger.
-  ** If the UPACKED_PREFIX_MATCH flag is set, then keys with common prefixes
-  ** are considered to be equal.  Otherwise, the longer key is the 
-  ** larger.  As it happens, the pPKey2 will always be the longer
-  ** if there is a difference.
-  */
-  assert( rc==0 );
-  if( pPKey2->flags & UNPACKED_INCRKEY ){
-    rc = -1;
-  }else if( pPKey2->flags & UNPACKED_PREFIX_MATCH ){
-    /* Leave rc==0 */
-  }else if( idx1<szHdr1 ){
-    rc = 1;
+  ** all the fields up to that point were equal. Return the default_rc
+  ** value.  */
+  rc = pPKey2->default_rc;
+
+debugCompareEnd:
+  if( desiredResult==0 && rc==0 ) return 1;
+  if( desiredResult<0 && rc<0 ) return 1;
+  if( desiredResult>0 && rc>0 ) return 1;
+  if( CORRUPT_DB ) return 1;
+  if( pKeyInfo->db->mallocFailed ) return 1;
+  return 0;
+}
+#endif
+
+#if SQLITE_DEBUG
+/*
+** Count the number of fields (a.k.a. columns) in the record given by
+** pKey,nKey.  The verify that this count is less than or equal to the
+** limit given by pKeyInfo->nField + pKeyInfo->nXField.
+**
+** If this constraint is not satisfied, it means that the high-speed
+** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will
+** not work correctly.  If this assert() ever fires, it probably means
+** that the KeyInfo.nField or KeyInfo.nXField values were computed
+** incorrectly.
+*/
+static void vdbeAssertFieldCountWithinLimits(
+  int nKey, const void *pKey,   /* The record to verify */ 
+  const KeyInfo *pKeyInfo       /* Compare size with this KeyInfo */
+){
+  int nField = 0;
+  u32 szHdr;
+  u32 idx;
+  u32 notUsed;
+  const unsigned char *aKey = (const unsigned char*)pKey;
+
+  if( CORRUPT_DB ) return;
+  idx = getVarint32(aKey, szHdr);
+  assert( nKey>=0 );
+  assert( szHdr<=(u32)nKey );
+  while( idx<szHdr ){
+    idx += getVarint32(aKey+idx, notUsed);
+    nField++;
   }
-  return rc;
+  assert( nField <= pKeyInfo->nField+pKeyInfo->nXField );
 }
+#else
+# define vdbeAssertFieldCountWithinLimits(A,B,C)
+#endif
+
+/*
+** Both *pMem1 and *pMem2 contain string values. Compare the two values
+** using the collation sequence pColl. As usual, return a negative , zero
+** or positive value if *pMem1 is less than, equal to or greater than 
+** *pMem2, respectively. Similar in spirit to "rc = (*pMem1) - (*pMem2);".
+*/
+static int vdbeCompareMemString(
+  const Mem *pMem1,
+  const Mem *pMem2,
+  const CollSeq *pColl,
+  u8 *prcErr                      /* If an OOM occurs, set to SQLITE_NOMEM */
+){
+  if( pMem1->enc==pColl->enc ){
+    /* The strings are already in the correct encoding.  Call the
+     ** comparison function directly */
+    return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
+  }else{
+    int rc;
+    const void *v1, *v2;
+    int n1, n2;
+    Mem c1;
+    Mem c2;
+    sqlite3VdbeMemInit(&c1, pMem1->db, MEM_Null);
+    sqlite3VdbeMemInit(&c2, pMem1->db, MEM_Null);
+    sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
+    sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
+    v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
+    n1 = v1==0 ? 0 : c1.n;
+    v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
+    n2 = v2==0 ? 0 : c2.n;
+    rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
+    if( (v1==0 || v2==0) && prcErr ) *prcErr = SQLITE_NOMEM_BKPT;
+    sqlite3VdbeMemRelease(&c1);
+    sqlite3VdbeMemRelease(&c2);
+    return rc;
+  }
+}
+
+/*
+** Compare two blobs.  Return negative, zero, or positive if the first
+** is less than, equal to, or greater than the second, respectively.
+** If one blob is a prefix of the other, then the shorter is the lessor.
+*/
+static SQLITE_NOINLINE int sqlite3BlobCompare(const Mem *pB1, const Mem *pB2){
+  int c = memcmp(pB1->z, pB2->z, pB1->n>pB2->n ? pB2->n : pB1->n);
+  if( c ) return c;
+  return pB1->n - pB2->n;
+}
+
+/*
+** Do a comparison between a 64-bit signed integer and a 64-bit floating-point
+** number.  Return negative, zero, or positive if the first (i64) is less than,
+** equal to, or greater than the second (double).
+*/
+static int sqlite3IntFloatCompare(i64 i, double r){
+  if( sizeof(LONGDOUBLE_TYPE)>8 ){
+    LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
+    if( x<r ) return -1;
+    if( x>r ) return +1;
+    return 0;
+  }else{
+    i64 y;
+    double s;
+    if( r<-9223372036854775808.0 ) return +1;
+    if( r>9223372036854775807.0 ) return -1;
+    y = (i64)r;
+    if( i<y ) return -1;
+    if( i>y ){
+      if( y==SMALLEST_INT64 && r>0.0 ) return -1;
+      return +1;
+    }
+    s = (double)i;
+    if( s<r ) return -1;
+    if( s>r ) return +1;
+    return 0;
+  }
+}
+
+/*
+** Compare the values contained by the two memory cells, returning
+** negative, zero or positive if pMem1 is less than, equal to, or greater
+** than pMem2. Sorting order is NULL's first, followed by numbers (integers
+** and reals) sorted numerically, followed by text ordered by the collating
+** sequence pColl and finally blob's ordered by memcmp().
+**
+** Two NULL values are considered equal by this function.
+*/
+SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
+  int f1, f2;
+  int combined_flags;
+
+  f1 = pMem1->flags;
+  f2 = pMem2->flags;
+  combined_flags = f1|f2;
+  assert( (combined_flags & MEM_RowSet)==0 );
  
+  /* If one value is NULL, it is less than the other. If both values
+  ** are NULL, return 0.
+  */
+  if( combined_flags&MEM_Null ){
+    return (f2&MEM_Null) - (f1&MEM_Null);
+  }
+
+  /* At least one of the two values is a number
+  */
+  if( combined_flags&(MEM_Int|MEM_Real) ){
+    if( (f1 & f2 & MEM_Int)!=0 ){
+      if( pMem1->u.i < pMem2->u.i ) return -1;
+      if( pMem1->u.i > pMem2->u.i ) return +1;
+      return 0;
+    }
+    if( (f1 & f2 & MEM_Real)!=0 ){
+      if( pMem1->u.r < pMem2->u.r ) return -1;
+      if( pMem1->u.r > pMem2->u.r ) return +1;
+      return 0;
+    }
+    if( (f1&MEM_Int)!=0 ){
+      if( (f2&MEM_Real)!=0 ){
+        return sqlite3IntFloatCompare(pMem1->u.i, pMem2->u.r);
+      }else{
+        return -1;
+      }
+    }
+    if( (f1&MEM_Real)!=0 ){
+      if( (f2&MEM_Int)!=0 ){
+        return -sqlite3IntFloatCompare(pMem2->u.i, pMem1->u.r);
+      }else{
+        return -1;
+      }
+    }
+    return +1;
+  }
+
+  /* If one value is a string and the other is a blob, the string is less.
+  ** If both are strings, compare using the collating functions.
+  */
+  if( combined_flags&MEM_Str ){
+    if( (f1 & MEM_Str)==0 ){
+      return 1;
+    }
+    if( (f2 & MEM_Str)==0 ){
+      return -1;
+    }
+
+    assert( pMem1->enc==pMem2->enc || pMem1->db->mallocFailed );
+    assert( pMem1->enc==SQLITE_UTF8 || 
+            pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
+
+    /* The collation sequence must be defined at this point, even if
+    ** the user deletes the collation sequence after the vdbe program is
+    ** compiled (this was not always the case).
+    */
+    assert( !pColl || pColl->xCmp );
+
+    if( pColl ){
+      return vdbeCompareMemString(pMem1, pMem2, pColl, 0);
+    }
+    /* If a NULL pointer was passed as the collate function, fall through
+    ** to the blob case and use memcmp().  */
+  }
+ 
+  /* Both values must be blobs.  Compare using memcmp().  */
+  return sqlite3BlobCompare(pMem1, pMem2);
+}
+
+
+/*
+** The first argument passed to this function is a serial-type that
+** corresponds to an integer - all values between 1 and 9 inclusive 
+** except 7. The second points to a buffer containing an integer value
+** serialized according to serial_type. This function deserializes
+** and returns the value.
+*/
+static i64 vdbeRecordDecodeInt(u32 serial_type, const u8 *aKey){
+  u32 y;
+  assert( CORRUPT_DB || (serial_type>=1 && serial_type<=9 && serial_type!=7) );
+  switch( serial_type ){
+    case 0:
+    case 1:
+      testcase( aKey[0]&0x80 );
+      return ONE_BYTE_INT(aKey);
+    case 2:
+      testcase( aKey[0]&0x80 );
+      return TWO_BYTE_INT(aKey);
+    case 3:
+      testcase( aKey[0]&0x80 );
+      return THREE_BYTE_INT(aKey);
+    case 4: {
+      testcase( aKey[0]&0x80 );
+      y = FOUR_BYTE_UINT(aKey);
+      return (i64)*(int*)&y;
+    }
+    case 5: {
+      testcase( aKey[0]&0x80 );
+      return FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
+    }
+    case 6: {
+      u64 x = FOUR_BYTE_UINT(aKey);
+      testcase( aKey[0]&0x80 );
+      x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
+      return (i64)*(i64*)&x;
+    }
+  }
+
+  return (serial_type - 8);
+}
+
+/*
+** This function compares the two table rows or index records
+** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero
+** or positive integer if key1 is less than, equal to or 
+** greater than key2.  The {nKey1, pKey1} key must be a blob
+** created by the OP_MakeRecord opcode of the VDBE.  The pPKey2
+** key must be a parsed key such as obtained from
+** sqlite3VdbeParseRecord.
+**
+** If argument bSkip is non-zero, it is assumed that the caller has already
+** determined that the first fields of the keys are equal.
+**
+** Key1 and Key2 do not have to contain the same number of fields. If all 
+** fields that appear in both keys are equal, then pPKey2->default_rc is 
+** returned.
+**
+** If database corruption is discovered, set pPKey2->errCode to 
+** SQLITE_CORRUPT and return 0. If an OOM error is encountered, 
+** pPKey2->errCode is set to SQLITE_NOMEM and, if it is not NULL, the
+** malloc-failed flag set on database handle (pPKey2->pKeyInfo->db).
+*/
+SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(
+  int nKey1, const void *pKey1,   /* Left key */
+  UnpackedRecord *pPKey2,         /* Right key */
+  int bSkip                       /* If true, skip the first field */
+){
+  u32 d1;                         /* Offset into aKey[] of next data element */
+  int i;                          /* Index of next field to compare */
+  u32 szHdr1;                     /* Size of record header in bytes */
+  u32 idx1;                       /* Offset of first type in header */
+  int rc = 0;                     /* Return value */
+  Mem *pRhs = pPKey2->aMem;       /* Next field of pPKey2 to compare */
+  KeyInfo *pKeyInfo = pPKey2->pKeyInfo;
+  const unsigned char *aKey1 = (const unsigned char *)pKey1;
+  Mem mem1;
+
+  /* If bSkip is true, then the caller has already determined that the first
+  ** two elements in the keys are equal. Fix the various stack variables so
+  ** that this routine begins comparing at the second field. */
+  if( bSkip ){
+    u32 s1;
+    idx1 = 1 + getVarint32(&aKey1[1], s1);
+    szHdr1 = aKey1[0];
+    d1 = szHdr1 + sqlite3VdbeSerialTypeLen(s1);
+    i = 1;
+    pRhs++;
+  }else{
+    idx1 = getVarint32(aKey1, szHdr1);
+    d1 = szHdr1;
+    if( d1>(unsigned)nKey1 ){ 
+      pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
+      return 0;  /* Corruption */
+    }
+    i = 0;
+  }
+
+  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
+  assert( pPKey2->pKeyInfo->nField+pPKey2->pKeyInfo->nXField>=pPKey2->nField 
+       || CORRUPT_DB );
+  assert( pPKey2->pKeyInfo->aSortOrder!=0 );
+  assert( pPKey2->pKeyInfo->nField>0 );
+  assert( idx1<=szHdr1 || CORRUPT_DB );
+  do{
+    u32 serial_type;
+
+    /* RHS is an integer */
+    if( pRhs->flags & MEM_Int ){
+      serial_type = aKey1[idx1];
+      testcase( serial_type==12 );
+      if( serial_type>=10 ){
+        rc = +1;
+      }else if( serial_type==0 ){
+        rc = -1;
+      }else if( serial_type==7 ){
+        sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
+        rc = -sqlite3IntFloatCompare(pRhs->u.i, mem1.u.r);
+      }else{
+        i64 lhs = vdbeRecordDecodeInt(serial_type, &aKey1[d1]);
+        i64 rhs = pRhs->u.i;
+        if( lhs<rhs ){
+          rc = -1;
+        }else if( lhs>rhs ){
+          rc = +1;
+        }
+      }
+    }
+
+    /* RHS is real */
+    else if( pRhs->flags & MEM_Real ){
+      serial_type = aKey1[idx1];
+      if( serial_type>=10 ){
+        /* Serial types 12 or greater are strings and blobs (greater than
+        ** numbers). Types 10 and 11 are currently "reserved for future 
+        ** use", so it doesn't really matter what the results of comparing
+        ** them to numberic values are.  */
+        rc = +1;
+      }else if( serial_type==0 ){
+        rc = -1;
+      }else{
+        sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
+        if( serial_type==7 ){
+          if( mem1.u.r<pRhs->u.r ){
+            rc = -1;
+          }else if( mem1.u.r>pRhs->u.r ){
+            rc = +1;
+          }
+        }else{
+          rc = sqlite3IntFloatCompare(mem1.u.i, pRhs->u.r);
+        }
+      }
+    }
+
+    /* RHS is a string */
+    else if( pRhs->flags & MEM_Str ){
+      getVarint32(&aKey1[idx1], serial_type);
+      testcase( serial_type==12 );
+      if( serial_type<12 ){
+        rc = -1;
+      }else if( !(serial_type & 0x01) ){
+        rc = +1;
+      }else{
+        mem1.n = (serial_type - 12) / 2;
+        testcase( (d1+mem1.n)==(unsigned)nKey1 );
+        testcase( (d1+mem1.n+1)==(unsigned)nKey1 );
+        if( (d1+mem1.n) > (unsigned)nKey1 ){
+          pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
+          return 0;                /* Corruption */
+        }else if( pKeyInfo->aColl[i] ){
+          mem1.enc = pKeyInfo->enc;
+          mem1.db = pKeyInfo->db;
+          mem1.flags = MEM_Str;
+          mem1.z = (char*)&aKey1[d1];
+          rc = vdbeCompareMemString(
+              &mem1, pRhs, pKeyInfo->aColl[i], &pPKey2->errCode
+          );
+        }else{
+          int nCmp = MIN(mem1.n, pRhs->n);
+          rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
+          if( rc==0 ) rc = mem1.n - pRhs->n; 
+        }
+      }
+    }
+
+    /* RHS is a blob */
+    else if( pRhs->flags & MEM_Blob ){
+      getVarint32(&aKey1[idx1], serial_type);
+      testcase( serial_type==12 );
+      if( serial_type<12 || (serial_type & 0x01) ){
+        rc = -1;
+      }else{
+        int nStr = (serial_type - 12) / 2;
+        testcase( (d1+nStr)==(unsigned)nKey1 );
+        testcase( (d1+nStr+1)==(unsigned)nKey1 );
+        if( (d1+nStr) > (unsigned)nKey1 ){
+          pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
+          return 0;                /* Corruption */
+        }else{
+          int nCmp = MIN(nStr, pRhs->n);
+          rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
+          if( rc==0 ) rc = nStr - pRhs->n;
+        }
+      }
+    }
+
+    /* RHS is null */
+    else{
+      serial_type = aKey1[idx1];
+      rc = (serial_type!=0);
+    }
+
+    if( rc!=0 ){
+      if( pKeyInfo->aSortOrder[i] ){
+        rc = -rc;
+      }
+      assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, rc) );
+      assert( mem1.szMalloc==0 );  /* See comment below */
+      return rc;
+    }
+
+    i++;
+    pRhs++;
+    d1 += sqlite3VdbeSerialTypeLen(serial_type);
+    idx1 += sqlite3VarintLen(serial_type);
+  }while( idx1<(unsigned)szHdr1 && i<pPKey2->nField && d1<=(unsigned)nKey1 );
+
+  /* No memory allocation is ever used on mem1.  Prove this using
+  ** the following assert().  If the assert() fails, it indicates a
+  ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).  */
+  assert( mem1.szMalloc==0 );
+
+  /* rc==0 here means that one or both of the keys ran out of fields and
+  ** all the fields up to that point were equal. Return the default_rc
+  ** value.  */
+  assert( CORRUPT_DB 
+       || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc) 
+       || pKeyInfo->db->mallocFailed
+  );
+  pPKey2->eqSeen = 1;
+  return pPKey2->default_rc;
+}
+SQLITE_PRIVATE int sqlite3VdbeRecordCompare(
+  int nKey1, const void *pKey1,   /* Left key */
+  UnpackedRecord *pPKey2          /* Right key */
+){
+  return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);
+}
+
+
+/*
+** This function is an optimized version of sqlite3VdbeRecordCompare() 
+** that (a) the first field of pPKey2 is an integer, and (b) the 
+** size-of-header varint at the start of (pKey1/nKey1) fits in a single
+** byte (i.e. is less than 128).
+**
+** To avoid concerns about buffer overreads, this routine is only used
+** on schemas where the maximum valid header size is 63 bytes or less.
+*/
+static int vdbeRecordCompareInt(
+  int nKey1, const void *pKey1, /* Left key */
+  UnpackedRecord *pPKey2        /* Right key */
+){
+  const u8 *aKey = &((const u8*)pKey1)[*(const u8*)pKey1 & 0x3F];
+  int serial_type = ((const u8*)pKey1)[1];
+  int res;
+  u32 y;
+  u64 x;
+  i64 v = pPKey2->aMem[0].u.i;
+  i64 lhs;
+
+  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
+  assert( (*(u8*)pKey1)<=0x3F || CORRUPT_DB );
+  switch( serial_type ){
+    case 1: { /* 1-byte signed integer */
+      lhs = ONE_BYTE_INT(aKey);
+      testcase( lhs<0 );
+      break;
+    }
+    case 2: { /* 2-byte signed integer */
+      lhs = TWO_BYTE_INT(aKey);
+      testcase( lhs<0 );
+      break;
+    }
+    case 3: { /* 3-byte signed integer */
+      lhs = THREE_BYTE_INT(aKey);
+      testcase( lhs<0 );
+      break;
+    }
+    case 4: { /* 4-byte signed integer */
+      y = FOUR_BYTE_UINT(aKey);
+      lhs = (i64)*(int*)&y;
+      testcase( lhs<0 );
+      break;
+    }
+    case 5: { /* 6-byte signed integer */
+      lhs = FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
+      testcase( lhs<0 );
+      break;
+    }
+    case 6: { /* 8-byte signed integer */
+      x = FOUR_BYTE_UINT(aKey);
+      x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
+      lhs = *(i64*)&x;
+      testcase( lhs<0 );
+      break;
+    }
+    case 8: 
+      lhs = 0;
+      break;
+    case 9:
+      lhs = 1;
+      break;
+
+    /* This case could be removed without changing the results of running
+    ** this code. Including it causes gcc to generate a faster switch 
+    ** statement (since the range of switch targets now starts at zero and
+    ** is contiguous) but does not cause any duplicate code to be generated
+    ** (as gcc is clever enough to combine the two like cases). Other 
+    ** compilers might be similar.  */ 
+    case 0: case 7:
+      return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
+
+    default:
+      return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
+  }
+
+  if( v>lhs ){
+    res = pPKey2->r1;
+  }else if( v<lhs ){
+    res = pPKey2->r2;
+  }else if( pPKey2->nField>1 ){
+    /* The first fields of the two keys are equal. Compare the trailing 
+    ** fields.  */
+    res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
+  }else{
+    /* The first fields of the two keys are equal and there are no trailing
+    ** fields. Return pPKey2->default_rc in this case. */
+    res = pPKey2->default_rc;
+    pPKey2->eqSeen = 1;
+  }
+
+  assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res) );
+  return res;
+}
+
+/*
+** This function is an optimized version of sqlite3VdbeRecordCompare() 
+** that (a) the first field of pPKey2 is a string, that (b) the first field
+** uses the collation sequence BINARY and (c) that the size-of-header varint 
+** at the start of (pKey1/nKey1) fits in a single byte.
+*/
+static int vdbeRecordCompareString(
+  int nKey1, const void *pKey1, /* Left key */
+  UnpackedRecord *pPKey2        /* Right key */
+){
+  const u8 *aKey1 = (const u8*)pKey1;
+  int serial_type;
+  int res;
+
+  assert( pPKey2->aMem[0].flags & MEM_Str );
+  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
+  getVarint32(&aKey1[1], serial_type);
+  if( serial_type<12 ){
+    res = pPKey2->r1;      /* (pKey1/nKey1) is a number or a null */
+  }else if( !(serial_type & 0x01) ){ 
+    res = pPKey2->r2;      /* (pKey1/nKey1) is a blob */
+  }else{
+    int nCmp;
+    int nStr;
+    int szHdr = aKey1[0];
+
+    nStr = (serial_type-12) / 2;
+    if( (szHdr + nStr) > nKey1 ){
+      pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
+      return 0;    /* Corruption */
+    }
+    nCmp = MIN( pPKey2->aMem[0].n, nStr );
+    res = memcmp(&aKey1[szHdr], pPKey2->aMem[0].z, nCmp);
+
+    if( res==0 ){
+      res = nStr - pPKey2->aMem[0].n;
+      if( res==0 ){
+        if( pPKey2->nField>1 ){
+          res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
+        }else{
+          res = pPKey2->default_rc;
+          pPKey2->eqSeen = 1;
+        }
+      }else if( res>0 ){
+        res = pPKey2->r2;
+      }else{
+        res = pPKey2->r1;
+      }
+    }else if( res>0 ){
+      res = pPKey2->r2;
+    }else{
+      res = pPKey2->r1;
+    }
+  }
+
+  assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res)
+       || CORRUPT_DB
+       || pPKey2->pKeyInfo->db->mallocFailed
+  );
+  return res;
+}
+
+/*
+** Return a pointer to an sqlite3VdbeRecordCompare() compatible function
+** suitable for comparing serialized records to the unpacked record passed
+** as the only argument.
+*/
+SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord *p){
+  /* varintRecordCompareInt() and varintRecordCompareString() both assume
+  ** that the size-of-header varint that occurs at the start of each record
+  ** fits in a single byte (i.e. is 127 or less). varintRecordCompareInt()
+  ** also assumes that it is safe to overread a buffer by at least the 
+  ** maximum possible legal header size plus 8 bytes. Because there is
+  ** guaranteed to be at least 74 (but not 136) bytes of padding following each
+  ** buffer passed to varintRecordCompareInt() this makes it convenient to
+  ** limit the size of the header to 64 bytes in cases where the first field
+  ** is an integer.
+  **
+  ** The easiest way to enforce this limit is to consider only records with
+  ** 13 fields or less. If the first field is an integer, the maximum legal
+  ** header size is (12*5 + 1 + 1) bytes.  */
+  if( (p->pKeyInfo->nField + p->pKeyInfo->nXField)<=13 ){
+    int flags = p->aMem[0].flags;
+    if( p->pKeyInfo->aSortOrder[0] ){
+      p->r1 = 1;
+      p->r2 = -1;
+    }else{
+      p->r1 = -1;
+      p->r2 = 1;
+    }
+    if( (flags & MEM_Int) ){
+      return vdbeRecordCompareInt;
+    }
+    testcase( flags & MEM_Real );
+    testcase( flags & MEM_Null );
+    testcase( flags & MEM_Blob );
+    if( (flags & (MEM_Real|MEM_Null|MEM_Blob))==0 && p->pKeyInfo->aColl[0]==0 ){
+      assert( flags & MEM_Str );
+      return vdbeRecordCompareString;
+    }
+  }
+
+  return sqlite3VdbeRecordCompare;
+}
 
 /*
 ** pCur points at an index entry created using the OP_MakeRecord opcode.
@@ -61245,21 +74659,18 @@ SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
   u32 lenRowid;     /* Size of the rowid */
   Mem m, v;
 
-  UNUSED_PARAMETER(db);
-
   /* Get the size of the index entry.  Only indices entries of less
   ** than 2GiB are support - anything large must be database corruption.
   ** Any corruption is detected in sqlite3BtreeParseCellPtr(), though, so
   ** this code can safely assume that nCellKey is 32-bits  
   */
   assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );     /* pCur is always valid so KeySize cannot fail */
+  nCellKey = sqlite3BtreePayloadSize(pCur);
   assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );
 
   /* Read in the complete content of the index entry */
-  memset(&m, 0, sizeof(m));
-  rc = sqlite3VdbeMemFromBtree(pCur, 0, (int)nCellKey, 1, &m);
+  sqlite3VdbeMemInit(&m, db, 0);
+  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
   if( rc ){
     return rc;
   }
@@ -61286,7 +74697,7 @@ SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
   if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){
     goto idx_rowid_corruption;
   }
-  lenRowid = sqlite3VdbeSerialTypeLen(typeRowid);
+  lenRowid = sqlite3SmallTypeSizes[typeRowid];
   testcase( (u32)m.n==szHdr+lenRowid );
   if( unlikely((u32)m.n<szHdr+lenRowid) ){
     goto idx_rowid_corruption;
@@ -61301,7 +74712,7 @@ SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
   /* Jump here if database corruption is detected after m has been
   ** allocated.  Free the m object and return SQLITE_CORRUPT. */
 idx_rowid_corruption:
-  testcase( m.zMalloc!=0 );
+  testcase( m.szMalloc!=0 );
   sqlite3VdbeMemRelease(&m);
   return SQLITE_CORRUPT_BKPT;
 }
@@ -61318,30 +74729,31 @@ idx_rowid_corruption:
 ** of the keys prior to the final rowid, not the entire key.
 */
 SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(
-  VdbeCursor *pC,             /* The cursor to compare against */
-  UnpackedRecord *pUnpacked,  /* Unpacked version of key to compare against */
-  int *res                    /* Write the comparison result here */
+  sqlite3 *db,                     /* Database connection */
+  VdbeCursor *pC,                  /* The cursor to compare against */
+  UnpackedRecord *pUnpacked,       /* Unpacked version of key */
+  int *res                         /* Write the comparison result here */
 ){
   i64 nCellKey = 0;
   int rc;
-  BtCursor *pCur = pC->pCursor;
+  BtCursor *pCur;
   Mem m;
 
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCur = pC->uc.pCursor;
   assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
-  /* nCellKey will always be between 0 and 0xffffffff because of the say
+  nCellKey = sqlite3BtreePayloadSize(pCur);
+  /* nCellKey will always be between 0 and 0xffffffff because of the way
   ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
   if( nCellKey<=0 || nCellKey>0x7fffffff ){
     *res = 0;
     return SQLITE_CORRUPT_BKPT;
   }
-  memset(&m, 0, sizeof(m));
-  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (int)nCellKey, 1, &m);
+  sqlite3VdbeMemInit(&m, db, 0);
+  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
   if( rc ){
     return rc;
   }
-  assert( pUnpacked->flags & UNPACKED_IGNORE_ROWID );
   *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
   sqlite3VdbeMemRelease(&m);
   return SQLITE_OK;
@@ -61397,7 +74809,7 @@ SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe *v){
 **
 ** The returned value must be freed by the caller using sqlite3ValueFree().
 */
-SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetValue(Vdbe *v, int iVar, u8 aff){
+SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff){
   assert( iVar>0 );
   if( v ){
     Mem *pMem = &v->aVar[iVar-1];
@@ -61406,7 +74818,6 @@ SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetValue(Vdbe *v, int iVar, u8 aff){
       if( pRet ){
         sqlite3VdbeMemCopy((Mem *)pRet, pMem);
         sqlite3ValueApplyAffinity(pRet, aff, SQLITE_UTF8);
-        sqlite3VdbeMemStoreType((Mem *)pRet);
       }
       return pRet;
     }
@@ -61428,6 +74839,107 @@ SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
   }
 }
 
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
+** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
+** in memory obtained from sqlite3DbMalloc).
+*/
+SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
+  if( pVtab->zErrMsg ){
+    sqlite3 *db = p->db;
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
+    sqlite3_free(pVtab->zErrMsg);
+    pVtab->zErrMsg = 0;
+  }
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+
+/*
+** If the second argument is not NULL, release any allocations associated 
+** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord
+** structure itself, using sqlite3DbFree().
+**
+** This function is used to free UnpackedRecord structures allocated by
+** the vdbeUnpackRecord() function found in vdbeapi.c.
+*/
+static void vdbeFreeUnpacked(sqlite3 *db, UnpackedRecord *p){
+  if( p ){
+    int i;
+    for(i=0; i<p->nField; i++){
+      Mem *pMem = &p->aMem[i];
+      if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);
+    }
+    sqlite3DbFree(db, p);
+  }
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Invoke the pre-update hook. If this is an UPDATE or DELETE pre-update call,
+** then cursor passed as the second argument should point to the row about
+** to be update or deleted. If the application calls sqlite3_preupdate_old(),
+** the required value will be read from the row the cursor points to.
+*/
+SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(
+  Vdbe *v,                        /* Vdbe pre-update hook is invoked by */
+  VdbeCursor *pCsr,               /* Cursor to grab old.* values from */
+  int op,                         /* SQLITE_INSERT, UPDATE or DELETE */
+  const char *zDb,                /* Database name */
+  Table *pTab,                    /* Modified table */
+  i64 iKey1,                      /* Initial key value */
+  int iReg                        /* Register for new.* record */
+){
+  sqlite3 *db = v->db;
+  i64 iKey2;
+  PreUpdate preupdate;
+  const char *zTbl = pTab->zName;
+  static const u8 fakeSortOrder = 0;
+
+  assert( db->pPreUpdate==0 );
+  memset(&preupdate, 0, sizeof(PreUpdate));
+  if( op==SQLITE_UPDATE ){
+    iKey2 = v->aMem[iReg].u.i;
+  }else{
+    iKey2 = iKey1;
+  }
+
+  assert( pCsr->nField==pTab->nCol 
+       || (pCsr->nField==pTab->nCol+1 && op==SQLITE_DELETE && iReg==-1)
+  );
+
+  preupdate.v = v;
+  preupdate.pCsr = pCsr;
+  preupdate.op = op;
+  preupdate.iNewReg = iReg;
+  preupdate.keyinfo.db = db;
+  preupdate.keyinfo.enc = ENC(db);
+  preupdate.keyinfo.nField = pTab->nCol;
+  preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
+  preupdate.iKey1 = iKey1;
+  preupdate.iKey2 = iKey2;
+  preupdate.iPKey = pTab->iPKey;
+
+  db->pPreUpdate = &preupdate;
+  db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
+  db->pPreUpdate = 0;
+  sqlite3DbFree(db, preupdate.aRecord);
+  vdbeFreeUnpacked(db, preupdate.pUnpacked);
+  vdbeFreeUnpacked(db, preupdate.pNewUnpacked);
+  if( preupdate.aNew ){
+    int i;
+    for(i=0; i<pCsr->nField; i++){
+      sqlite3VdbeMemRelease(&preupdate.aNew[i]);
+    }
+    sqlite3DbFree(db, preupdate.aNew);
+  }
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 /************** End of vdbeaux.c *********************************************/
 /************** Begin file vdbeapi.c *****************************************/
 /*
@@ -61445,6 +74957,8 @@ SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
 ** This file contains code use to implement APIs that are part of the
 ** VDBE.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
@@ -61455,7 +74969,7 @@ SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
 ** collating sequences are registered or if an authorizer function is
 ** added or changed.
 */
-SQLITE_API int sqlite3_expired(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt *pStmt){
   Vdbe *p = (Vdbe*)pStmt;
   return p==0 || p->expired;
 }
@@ -61483,6 +74997,38 @@ static int vdbeSafetyNotNull(Vdbe *p){
   }
 }
 
+#ifndef SQLITE_OMIT_TRACE
+/*
+** Invoke the profile callback.  This routine is only called if we already
+** know that the profile callback is defined and needs to be invoked.
+*/
+static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
+  sqlite3_int64 iNow;
+  sqlite3_int64 iElapse;
+  assert( p->startTime>0 );
+  assert( db->xProfile!=0 || (db->mTrace & SQLITE_TRACE_PROFILE)!=0 );
+  assert( db->init.busy==0 );
+  assert( p->zSql!=0 );
+  sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
+  iElapse = (iNow - p->startTime)*1000000;
+  if( db->xProfile ){
+    db->xProfile(db->pProfileArg, p->zSql, iElapse);
+  }
+  if( db->mTrace & SQLITE_TRACE_PROFILE ){
+    db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
+  }
+  p->startTime = 0;
+}
+/*
+** The checkProfileCallback(DB,P) macro checks to see if a profile callback
+** is needed, and it invokes the callback if it is needed.
+*/
+# define checkProfileCallback(DB,P) \
+   if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }
+#else
+# define checkProfileCallback(DB,P)  /*no-op*/
+#endif
+
 /*
 ** The following routine destroys a virtual machine that is created by
 ** the sqlite3_compile() routine. The integer returned is an SQLITE_
@@ -61492,7 +75038,7 @@ static int vdbeSafetyNotNull(Vdbe *p){
 ** This routine sets the error code and string returned by
 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
 */
-SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt){
   int rc;
   if( pStmt==0 ){
     /* IMPLEMENTATION-OF: R-57228-12904 Invoking sqlite3_finalize() on a NULL
@@ -61501,17 +75047,12 @@ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt){
   }else{
     Vdbe *v = (Vdbe*)pStmt;
     sqlite3 *db = v->db;
-#if SQLITE_THREADSAFE
-    sqlite3_mutex *mutex;
-#endif
     if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;
-#if SQLITE_THREADSAFE
-    mutex = v->db->mutex;
-#endif
-    sqlite3_mutex_enter(mutex);
+    sqlite3_mutex_enter(db->mutex);
+    checkProfileCallback(db, v);
     rc = sqlite3VdbeFinalize(v);
     rc = sqlite3ApiExit(db, rc);
-    sqlite3_mutex_leave(mutex);
+    sqlite3LeaveMutexAndCloseZombie(db);
   }
   return rc;
 }
@@ -61524,18 +75065,20 @@ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt){
 ** This routine sets the error code and string returned by
 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
 */
-SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt){
   int rc;
   if( pStmt==0 ){
     rc = SQLITE_OK;
   }else{
     Vdbe *v = (Vdbe*)pStmt;
-    sqlite3_mutex_enter(v->db->mutex);
+    sqlite3 *db = v->db;
+    sqlite3_mutex_enter(db->mutex);
+    checkProfileCallback(db, v);
     rc = sqlite3VdbeReset(v);
     sqlite3VdbeRewind(v);
-    assert( (rc & (v->db->errMask))==rc );
-    rc = sqlite3ApiExit(v->db, rc);
-    sqlite3_mutex_leave(v->db->mutex);
+    assert( (rc & (db->errMask))==rc );
+    rc = sqlite3ApiExit(db, rc);
+    sqlite3_mutex_leave(db->mutex);
   }
   return rc;
 }
@@ -61543,7 +75086,7 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt){
 /*
 ** Set all the parameters in the compiled SQL statement to NULL.
 */
-SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt *pStmt){
   int i;
   int rc = SQLITE_OK;
   Vdbe *p = (Vdbe*)pStmt;
@@ -61567,57 +75110,134 @@ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
 ** The following routines extract information from a Mem or sqlite3_value
 ** structure.
 */
-SQLITE_API const void *sqlite3_value_blob(sqlite3_value *pVal){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value *pVal){
   Mem *p = (Mem*)pVal;
   if( p->flags & (MEM_Blob|MEM_Str) ){
-    sqlite3VdbeMemExpandBlob(p);
-    p->flags &= ~MEM_Str;
+    if( sqlite3VdbeMemExpandBlob(p)!=SQLITE_OK ){
+      assert( p->flags==MEM_Null && p->z==0 );
+      return 0;
+    }
     p->flags |= MEM_Blob;
     return p->n ? p->z : 0;
   }else{
     return sqlite3_value_text(pVal);
   }
 }
-SQLITE_API int sqlite3_value_bytes(sqlite3_value *pVal){
+SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value *pVal){
   return sqlite3ValueBytes(pVal, SQLITE_UTF8);
 }
-SQLITE_API int sqlite3_value_bytes16(sqlite3_value *pVal){
+SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value *pVal){
   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
 }
-SQLITE_API double sqlite3_value_double(sqlite3_value *pVal){
+SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value *pVal){
   return sqlite3VdbeRealValue((Mem*)pVal);
 }
-SQLITE_API int sqlite3_value_int(sqlite3_value *pVal){
+SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value *pVal){
   return (int)sqlite3VdbeIntValue((Mem*)pVal);
 }
-SQLITE_API sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
+SQLITE_API sqlite_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value *pVal){
   return sqlite3VdbeIntValue((Mem*)pVal);
 }
-SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
+SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value *pVal){
+  Mem *pMem = (Mem*)pVal;
+  return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
+}
+SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value *pVal){
   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_value_text16(sqlite3_value* pVal){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value* pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
 }
-SQLITE_API const void *sqlite3_value_text16be(sqlite3_value *pVal){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value *pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16BE);
 }
-SQLITE_API const void *sqlite3_value_text16le(sqlite3_value *pVal){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value *pVal){
   return sqlite3ValueText(pVal, SQLITE_UTF16LE);
 }
 #endif /* SQLITE_OMIT_UTF16 */
-SQLITE_API int sqlite3_value_type(sqlite3_value* pVal){
-  return pVal->type;
+/* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five
+** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating
+** point number string BLOB NULL
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value* pVal){
+  static const u8 aType[] = {
+     SQLITE_BLOB,     /* 0x00 */
+     SQLITE_NULL,     /* 0x01 */
+     SQLITE_TEXT,     /* 0x02 */
+     SQLITE_NULL,     /* 0x03 */
+     SQLITE_INTEGER,  /* 0x04 */
+     SQLITE_NULL,     /* 0x05 */
+     SQLITE_INTEGER,  /* 0x06 */
+     SQLITE_NULL,     /* 0x07 */
+     SQLITE_FLOAT,    /* 0x08 */
+     SQLITE_NULL,     /* 0x09 */
+     SQLITE_FLOAT,    /* 0x0a */
+     SQLITE_NULL,     /* 0x0b */
+     SQLITE_INTEGER,  /* 0x0c */
+     SQLITE_NULL,     /* 0x0d */
+     SQLITE_INTEGER,  /* 0x0e */
+     SQLITE_NULL,     /* 0x0f */
+     SQLITE_BLOB,     /* 0x10 */
+     SQLITE_NULL,     /* 0x11 */
+     SQLITE_TEXT,     /* 0x12 */
+     SQLITE_NULL,     /* 0x13 */
+     SQLITE_INTEGER,  /* 0x14 */
+     SQLITE_NULL,     /* 0x15 */
+     SQLITE_INTEGER,  /* 0x16 */
+     SQLITE_NULL,     /* 0x17 */
+     SQLITE_FLOAT,    /* 0x18 */
+     SQLITE_NULL,     /* 0x19 */
+     SQLITE_FLOAT,    /* 0x1a */
+     SQLITE_NULL,     /* 0x1b */
+     SQLITE_INTEGER,  /* 0x1c */
+     SQLITE_NULL,     /* 0x1d */
+     SQLITE_INTEGER,  /* 0x1e */
+     SQLITE_NULL,     /* 0x1f */
+  };
+  return aType[pVal->flags&MEM_AffMask];
 }
 
+/* Make a copy of an sqlite3_value object
+*/
+SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value *pOrig){
+  sqlite3_value *pNew;
+  if( pOrig==0 ) return 0;
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  if( pNew==0 ) return 0;
+  memset(pNew, 0, sizeof(*pNew));
+  memcpy(pNew, pOrig, MEMCELLSIZE);
+  pNew->flags &= ~MEM_Dyn;
+  pNew->db = 0;
+  if( pNew->flags&(MEM_Str|MEM_Blob) ){
+    pNew->flags &= ~(MEM_Static|MEM_Dyn);
+    pNew->flags |= MEM_Ephem;
+    if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){
+      sqlite3ValueFree(pNew);
+      pNew = 0;
+    }
+  }
+  return pNew;
+}
+
+/* Destroy an sqlite3_value object previously obtained from
+** sqlite3_value_dup().
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value *pOld){
+  sqlite3ValueFree(pOld);
+}
+  
+
 /**************************** sqlite3_result_  *******************************
 ** The following routines are used by user-defined functions to specify
 ** the function result.
 **
-** The setStrOrError() funtion calls sqlite3VdbeMemSetStr() to store the
+** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
 ** result as a string or blob but if the string or blob is too large, it
 ** then sets the error code to SQLITE_TOOBIG
+**
+** The invokeValueDestructor(P,X) routine invokes destructor function X()
+** on value P is not going to be used and need to be destroyed.
 */
 static void setResultStrOrError(
   sqlite3_context *pCtx,  /* Function context */
@@ -61626,116 +75246,185 @@ static void setResultStrOrError(
   u8 enc,                 /* Encoding of z.  0 for BLOBs */
   void (*xDel)(void*)     /* Destructor function */
 ){
-  if( sqlite3VdbeMemSetStr(&pCtx->s, z, n, enc, xDel)==SQLITE_TOOBIG ){
+  if( sqlite3VdbeMemSetStr(pCtx->pOut, z, n, enc, xDel)==SQLITE_TOOBIG ){
     sqlite3_result_error_toobig(pCtx);
   }
 }
-SQLITE_API void sqlite3_result_blob(
+static int invokeValueDestructor(
+  const void *p,             /* Value to destroy */
+  void (*xDel)(void*),       /* The destructor */
+  sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
+){
+  assert( xDel!=SQLITE_DYNAMIC );
+  if( xDel==0 ){
+    /* noop */
+  }else if( xDel==SQLITE_TRANSIENT ){
+    /* noop */
+  }else{
+    xDel((void*)p);
+  }
+  if( pCtx ) sqlite3_result_error_toobig(pCtx);
+  return SQLITE_TOOBIG;
+}
+SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(
   sqlite3_context *pCtx, 
   const void *z, 
   int n, 
   void (*xDel)(void *)
 ){
   assert( n>=0 );
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, 0, xDel);
 }
-SQLITE_API void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(
+  sqlite3_context *pCtx, 
+  const void *z, 
+  sqlite3_uint64 n,
+  void (*xDel)(void *)
+){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  assert( xDel!=SQLITE_DYNAMIC );
+  if( n>0x7fffffff ){
+    (void)invokeValueDestructor(z, xDel, pCtx);
+  }else{
+    setResultStrOrError(pCtx, z, (int)n, 0, xDel);
+  }
+}
+SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context *pCtx, double rVal){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
 }
-SQLITE_API void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   pCtx->isError = SQLITE_ERROR;
-  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
+  pCtx->fErrorOrAux = 1;
+  sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   pCtx->isError = SQLITE_ERROR;
-  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
+  pCtx->fErrorOrAux = 1;
+  sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
 }
 #endif
-SQLITE_API void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context *pCtx, int iVal){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);
+}
+SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
 }
-SQLITE_API void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetNull(pCtx->pOut);
 }
-SQLITE_API void sqlite3_result_null(sqlite3_context *pCtx){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetNull(&pCtx->s);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  pOut->eSubtype = eSubtype & 0xff;
+  pOut->flags |= MEM_Subtype;
 }
-SQLITE_API void sqlite3_result_text(
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text(
   sqlite3_context *pCtx, 
   const char *z, 
   int n,
   void (*xDel)(void *)
 ){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
 }
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(
+  sqlite3_context *pCtx, 
+  const char *z, 
+  sqlite3_uint64 n,
+  void (*xDel)(void *),
+  unsigned char enc
+){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  assert( xDel!=SQLITE_DYNAMIC );
+  if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
+  if( n>0x7fffffff ){
+    (void)invokeValueDestructor(z, xDel, pCtx);
+  }else{
+    setResultStrOrError(pCtx, z, (int)n, enc, xDel);
+  }
+}
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API void sqlite3_result_text16(
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(
   sqlite3_context *pCtx, 
   const void *z, 
   int n, 
   void (*xDel)(void *)
 ){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, SQLITE_UTF16NATIVE, xDel);
 }
-SQLITE_API void sqlite3_result_text16be(
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(
   sqlite3_context *pCtx, 
   const void *z, 
   int n, 
   void (*xDel)(void *)
 ){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, SQLITE_UTF16BE, xDel);
 }
-SQLITE_API void sqlite3_result_text16le(
+SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(
   sqlite3_context *pCtx, 
   const void *z, 
   int n, 
   void (*xDel)(void *)
 ){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);
 }
 #endif /* SQLITE_OMIT_UTF16 */
-SQLITE_API void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemCopy(&pCtx->s, pValue);
-}
-SQLITE_API void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
+SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemCopy(pCtx->pOut, pValue);
+}
+SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetZeroBlob(pCtx->pOut, n);
+}
+SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
+  Mem *pOut = pCtx->pOut;
+  assert( sqlite3_mutex_held(pOut->db->mutex) );
+  if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    return SQLITE_TOOBIG;
+  }
+  sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
+  return SQLITE_OK;
 }
-SQLITE_API void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
   pCtx->isError = errCode;
-  if( pCtx->s.flags & MEM_Null ){
-    sqlite3VdbeMemSetStr(&pCtx->s, sqlite3ErrStr(errCode), -1, 
+  pCtx->fErrorOrAux = 1;
+#ifdef SQLITE_DEBUG
+  if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
+#endif
+  if( pCtx->pOut->flags & MEM_Null ){
+    sqlite3VdbeMemSetStr(pCtx->pOut, sqlite3ErrStr(errCode), -1, 
                          SQLITE_UTF8, SQLITE_STATIC);
   }
 }
 
 /* Force an SQLITE_TOOBIG error. */
-SQLITE_API void sqlite3_result_error_toobig(sqlite3_context *pCtx){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   pCtx->isError = SQLITE_TOOBIG;
-  sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1, 
+  pCtx->fErrorOrAux = 1;
+  sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1, 
                        SQLITE_UTF8, SQLITE_STATIC);
 }
 
 /* An SQLITE_NOMEM error. */
-SQLITE_API void sqlite3_result_error_nomem(sqlite3_context *pCtx){
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  sqlite3VdbeMemSetNull(&pCtx->s);
-  pCtx->isError = SQLITE_NOMEM;
-  pCtx->s.db->mallocFailed = 1;
+SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context *pCtx){
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+  sqlite3VdbeMemSetNull(pCtx->pOut);
+  pCtx->isError = SQLITE_NOMEM_BKPT;
+  pCtx->fErrorOrAux = 1;
+  sqlite3OomFault(pCtx->pOut->db);
 }
 
 /*
@@ -61749,7 +75438,10 @@ static int doWalCallbacks(sqlite3 *db){
   for(i=0; i<db->nDb; i++){
     Btree *pBt = db->aDb[i].pBt;
     if( pBt ){
-      int nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
+      int nEntry;
+      sqlite3BtreeEnter(pBt);
+      nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
+      sqlite3BtreeLeave(pBt);
       if( db->xWalCallback && nEntry>0 && rc==SQLITE_OK ){
         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zName, nEntry);
       }
@@ -61759,6 +75451,7 @@ static int doWalCallbacks(sqlite3 *db){
   return rc;
 }
 
+
 /*
 ** Execute the statement pStmt, either until a row of data is ready, the
 ** statement is completely executed or an error occurs.
@@ -61784,14 +75477,14 @@ static int sqlite3Step(Vdbe *p){
     **
     ** Nevertheless, some published applications that were originally written
     ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE 
-    ** returns, and the so were broken by the automatic-reset change.  As a
+    ** returns, and those were broken by the automatic-reset change.  As a
     ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
     ** legacy behavior of returning SQLITE_MISUSE for cases where the 
     ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
     ** or SQLITE_BUSY error.
     */
 #ifdef SQLITE_OMIT_AUTORESET
-    if( p->rc==SQLITE_BUSY || p->rc==SQLITE_LOCKED ){
+    if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
       sqlite3_reset((sqlite3_stmt*)p);
     }else{
       return SQLITE_MISUSE_BKPT;
@@ -61805,7 +75498,7 @@ static int sqlite3Step(Vdbe *p){
   db = p->db;
   if( db->mallocFailed ){
     p->rc = SQLITE_NOMEM;
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   if( p->pc<=0 && p->expired ){
@@ -61818,41 +75511,45 @@ static int sqlite3Step(Vdbe *p){
     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
     ** from interrupting a statement that has not yet started.
     */
-    if( db->activeVdbeCnt==0 ){
+    if( db->nVdbeActive==0 ){
       db->u1.isInterrupted = 0;
     }
 
-    assert( db->writeVdbeCnt>0 || db->autoCommit==0 || db->nDeferredCons==0 );
+    assert( db->nVdbeWrite>0 || db->autoCommit==0 
+        || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
+    );
 
 #ifndef SQLITE_OMIT_TRACE
-    if( db->xProfile && !db->init.busy ){
+    if( (db->xProfile || (db->mTrace & SQLITE_TRACE_PROFILE)!=0)
+        && !db->init.busy && p->zSql ){
       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
+    }else{
+      assert( p->startTime==0 );
     }
 #endif
 
-    db->activeVdbeCnt++;
-    if( p->readOnly==0 ) db->writeVdbeCnt++;
+    db->nVdbeActive++;
+    if( p->readOnly==0 ) db->nVdbeWrite++;
+    if( p->bIsReader ) db->nVdbeRead++;
     p->pc = 0;
   }
+#ifdef SQLITE_DEBUG
+  p->rcApp = SQLITE_OK;
+#endif
 #ifndef SQLITE_OMIT_EXPLAIN
   if( p->explain ){
     rc = sqlite3VdbeList(p);
   }else
 #endif /* SQLITE_OMIT_EXPLAIN */
   {
-    db->vdbeExecCnt++;
+    db->nVdbeExec++;
     rc = sqlite3VdbeExec(p);
-    db->vdbeExecCnt--;
+    db->nVdbeExec--;
   }
 
 #ifndef SQLITE_OMIT_TRACE
-  /* Invoke the profile callback if there is one
-  */
-  if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy && p->zSql ){
-    sqlite3_int64 iNow;
-    sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
-    db->xProfile(db->pProfileArg, p->zSql, (iNow - p->startTime)*1000000);
-  }
+  /* If the statement completed successfully, invoke the profile callback */
+  if( rc!=SQLITE_ROW ) checkProfileCallback(db, p);
 #endif
 
   if( rc==SQLITE_DONE ){
@@ -61865,7 +75562,7 @@ static int sqlite3Step(Vdbe *p){
 
   db->errCode = rc;
   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
-    p->rc = SQLITE_NOMEM;
+    p->rc = SQLITE_NOMEM_BKPT;
   }
 end_of_step:
   /* At this point local variable rc holds the value that should be 
@@ -61876,12 +75573,12 @@ end_of_step:
   ** were called on statement p.
   */
   assert( rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR 
-       || rc==SQLITE_BUSY || rc==SQLITE_MISUSE
+       || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
   );
-  assert( p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE );
+  assert( (p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE) || p->rc==p->rcApp );
   if( p->isPrepareV2 && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
     /* If this statement was prepared using sqlite3_prepare_v2(), and an
-    ** error has occured, then return the error code in p->rc to the
+    ** error has occurred, then return the error code in p->rc to the
     ** caller. Set the error code in the database handle to the same value.
     */ 
     rc = sqlite3VdbeTransferError(p);
@@ -61890,19 +75587,11 @@ end_of_step:
 }
 
 /*
-** The maximum number of times that a statement will try to reparse
-** itself before giving up and returning SQLITE_SCHEMA.
-*/
-#ifndef SQLITE_MAX_SCHEMA_RETRY
-# define SQLITE_MAX_SCHEMA_RETRY 5
-#endif
-
-/*
 ** This is the top-level implementation of sqlite3_step().  Call
 ** sqlite3Step() to do most of the work.  If a schema error occurs,
 ** call sqlite3Reprepare() and try again.
 */
-SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt *pStmt){
   int rc = SQLITE_OK;      /* Result from sqlite3Step() */
   int rc2 = SQLITE_OK;     /* Result from sqlite3Reprepare() */
   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
@@ -61914,13 +75603,17 @@ SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){
   }
   db = v->db;
   sqlite3_mutex_enter(db->mutex);
+  v->doingRerun = 0;
   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
-         && cnt++ < SQLITE_MAX_SCHEMA_RETRY
-         && (rc2 = rc = sqlite3Reprepare(v))==SQLITE_OK ){
+         && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
+    int savedPc = v->pc;
+    rc2 = rc = sqlite3Reprepare(v);
+    if( rc!=SQLITE_OK) break;
     sqlite3_reset(pStmt);
+    if( savedPc>=0 ) v->doingRerun = 1;
     assert( v->expired==0 );
   }
-  if( rc2!=SQLITE_OK && ALWAYS(v->isPrepareV2) && ALWAYS(db->pErr) ){
+  if( rc2!=SQLITE_OK ){
     /* This case occurs after failing to recompile an sql statement. 
     ** The error message from the SQL compiler has already been loaded 
     ** into the database handle. This block copies the error message 
@@ -61936,7 +75629,7 @@ SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){
       v->rc = rc2;
     } else {
       v->zErrMsg = 0;
-      v->rc = rc = SQLITE_NOMEM;
+      v->rc = rc = SQLITE_NOMEM_BKPT;
     }
   }
   rc = sqlite3ApiExit(db, rc);
@@ -61944,11 +75637,12 @@ SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){
   return rc;
 }
 
+
 /*
 ** Extract the user data from a sqlite3_context structure and return a
 ** pointer to it.
 */
-SQLITE_API void *sqlite3_user_data(sqlite3_context *p){
+SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context *p){
   assert( p && p->pFunc );
   return p->pFunc->pUserData;
 }
@@ -61963,9 +75657,32 @@ SQLITE_API void *sqlite3_user_data(sqlite3_context *p){
 ** sqlite3_create_function16() routines that originally registered the
 ** application defined function.
 */
-SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
-  assert( p && p->pFunc );
-  return p->s.db;
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context *p){
+  assert( p && p->pOut );
+  return p->pOut->db;
+}
+
+/*
+** Return the current time for a statement.  If the current time
+** is requested more than once within the same run of a single prepared
+** statement, the exact same time is returned for each invocation regardless
+** of the amount of time that elapses between invocations.  In other words,
+** the time returned is always the time of the first call.
+*/
+SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
+  int rc;
+#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
+  sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
+  assert( p->pVdbe!=0 );
+#else
+  sqlite3_int64 iTime = 0;
+  sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
+#endif
+  if( *piTime==0 ){
+    rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
+    if( rc ) *piTime = 0;
+  }
+  return *piTime;
 }
 
 /*
@@ -61991,82 +75708,102 @@ SQLITE_PRIVATE void sqlite3InvalidFunction(
 }
 
 /*
+** Create a new aggregate context for p and return a pointer to
+** its pMem->z element.
+*/
+static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
+  Mem *pMem = p->pMem;
+  assert( (pMem->flags & MEM_Agg)==0 );
+  if( nByte<=0 ){
+    sqlite3VdbeMemSetNull(pMem);
+    pMem->z = 0;
+  }else{
+    sqlite3VdbeMemClearAndResize(pMem, nByte);
+    pMem->flags = MEM_Agg;
+    pMem->u.pDef = p->pFunc;
+    if( pMem->z ){
+      memset(pMem->z, 0, nByte);
+    }
+  }
+  return (void*)pMem->z;
+}
+
+/*
 ** Allocate or return the aggregate context for a user function.  A new
 ** context is allocated on the first call.  Subsequent calls return the
 ** same context that was returned on prior calls.
 */
-SQLITE_API void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
-  Mem *pMem;
-  assert( p && p->pFunc && p->pFunc->xStep );
-  assert( sqlite3_mutex_held(p->s.db->mutex) );
-  pMem = p->pMem;
+SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context *p, int nByte){
+  assert( p && p->pFunc && p->pFunc->xFinalize );
+  assert( sqlite3_mutex_held(p->pOut->db->mutex) );
   testcase( nByte<0 );
-  if( (pMem->flags & MEM_Agg)==0 ){
-    if( nByte<=0 ){
-      sqlite3VdbeMemReleaseExternal(pMem);
-      pMem->flags = MEM_Null;
-      pMem->z = 0;
-    }else{
-      sqlite3VdbeMemGrow(pMem, nByte, 0);
-      pMem->flags = MEM_Agg;
-      pMem->u.pDef = p->pFunc;
-      if( pMem->z ){
-        memset(pMem->z, 0, nByte);
-      }
-    }
+  if( (p->pMem->flags & MEM_Agg)==0 ){
+    return createAggContext(p, nByte);
+  }else{
+    return (void*)p->pMem->z;
   }
-  return (void*)pMem->z;
 }
 
 /*
-** Return the auxilary data pointer, if any, for the iArg'th argument to
+** Return the auxiliary data pointer, if any, for the iArg'th argument to
 ** the user-function defined by pCtx.
 */
-SQLITE_API void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
-  VdbeFunc *pVdbeFunc;
+SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
+  AuxData *pAuxData;
 
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  pVdbeFunc = pCtx->pVdbeFunc;
-  if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
-    return 0;
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
+#if SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pCtx->pVdbe==0 ) return 0;
+#else
+  assert( pCtx->pVdbe!=0 );
+#endif
+  for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
+    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
   }
-  return pVdbeFunc->apAux[iArg].pAux;
+
+  return (pAuxData ? pAuxData->pAux : 0);
 }
 
 /*
-** Set the auxilary data pointer and delete function, for the iArg'th
+** Set the auxiliary data pointer and delete function, for the iArg'th
 ** argument to the user-function defined by pCtx. Any previous value is
 ** deleted by calling the delete function specified when it was set.
 */
-SQLITE_API void sqlite3_set_auxdata(
+SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(
   sqlite3_context *pCtx, 
   int iArg, 
   void *pAux, 
   void (*xDelete)(void*)
 ){
-  struct AuxData *pAuxData;
-  VdbeFunc *pVdbeFunc;
+  AuxData *pAuxData;
+  Vdbe *pVdbe = pCtx->pVdbe;
+
+  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
   if( iArg<0 ) goto failed;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( pVdbe==0 ) goto failed;
+#else
+  assert( pVdbe!=0 );
+#endif
 
-  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  pVdbeFunc = pCtx->pVdbeFunc;
-  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
-    int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
-    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
-    pVdbeFunc = sqlite3DbRealloc(pCtx->s.db, pVdbeFunc, nMalloc);
-    if( !pVdbeFunc ){
-      goto failed;
-    }
-    pCtx->pVdbeFunc = pVdbeFunc;
-    memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
-    pVdbeFunc->nAux = iArg+1;
-    pVdbeFunc->pFunc = pCtx->pFunc;
+  for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
+    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
   }
-
-  pAuxData = &pVdbeFunc->apAux[iArg];
-  if( pAuxData->pAux && pAuxData->xDelete ){
+  if( pAuxData==0 ){
+    pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
+    if( !pAuxData ) goto failed;
+    pAuxData->iOp = pCtx->iOp;
+    pAuxData->iArg = iArg;
+    pAuxData->pNext = pVdbe->pAuxData;
+    pVdbe->pAuxData = pAuxData;
+    if( pCtx->fErrorOrAux==0 ){
+      pCtx->isError = 0;
+      pCtx->fErrorOrAux = 1;
+    }
+  }else if( pAuxData->xDelete ){
     pAuxData->xDelete(pAuxData->pAux);
   }
+
   pAuxData->pAux = pAux;
   pAuxData->xDelete = xDelete;
   return;
@@ -62079,7 +75816,7 @@ failed:
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
-** Return the number of times the Step function of a aggregate has been 
+** Return the number of times the Step function of an aggregate has been 
 ** called.
 **
 ** This function is deprecated.  Do not use it for new code.  It is
@@ -62087,8 +75824,8 @@ failed:
 ** implementations should keep their own counts within their aggregate
 ** context.
 */
-SQLITE_API int sqlite3_aggregate_count(sqlite3_context *p){
-  assert( p && p->pMem && p->pFunc && p->pFunc->xStep );
+SQLITE_API int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context *p){
+  assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
   return p->pMem->n;
 }
 #endif
@@ -62096,7 +75833,7 @@ SQLITE_API int sqlite3_aggregate_count(sqlite3_context *p){
 /*
 ** Return the number of columns in the result set for the statement pStmt.
 */
-SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt){
   Vdbe *pVm = (Vdbe *)pStmt;
   return pVm ? pVm->nResColumn : 0;
 }
@@ -62105,12 +75842,48 @@ SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt){
 ** Return the number of values available from the current row of the
 ** currently executing statement pStmt.
 */
-SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt){
   Vdbe *pVm = (Vdbe *)pStmt;
   if( pVm==0 || pVm->pResultSet==0 ) return 0;
   return pVm->nResColumn;
 }
 
+/*
+** Return a pointer to static memory containing an SQL NULL value.
+*/
+static const Mem *columnNullValue(void){
+  /* Even though the Mem structure contains an element
+  ** of type i64, on certain architectures (x86) with certain compiler
+  ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
+  ** instead of an 8-byte one. This all works fine, except that when
+  ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
+  ** that a Mem structure is located on an 8-byte boundary. To prevent
+  ** these assert()s from failing, when building with SQLITE_DEBUG defined
+  ** using gcc, we force nullMem to be 8-byte aligned using the magical
+  ** __attribute__((aligned(8))) macro.  */
+  static const Mem nullMem 
+#if defined(SQLITE_DEBUG) && defined(__GNUC__)
+    __attribute__((aligned(8))) 
+#endif
+    = {
+        /* .u          = */ {0},
+        /* .flags      = */ (u16)MEM_Null,
+        /* .enc        = */ (u8)0,
+        /* .eSubtype   = */ (u8)0,
+        /* .n          = */ (int)0,
+        /* .z          = */ (char*)0,
+        /* .zMalloc    = */ (char*)0,
+        /* .szMalloc   = */ (int)0,
+        /* .uTemp      = */ (u32)0,
+        /* .db         = */ (sqlite3*)0,
+        /* .xDel       = */ (void(*)(void*))0,
+#ifdef SQLITE_DEBUG
+        /* .pScopyFrom = */ (Mem*)0,
+        /* .pFiller    = */ (void*)0,
+#endif
+      };
+  return &nullMem;
+}
 
 /*
 ** Check to see if column iCol of the given statement is valid.  If
@@ -62127,32 +75900,11 @@ static Mem *columnMem(sqlite3_stmt *pStmt, int i){
     sqlite3_mutex_enter(pVm->db->mutex);
     pOut = &pVm->pResultSet[i];
   }else{
-    /* If the value passed as the second argument is out of range, return
-    ** a pointer to the following static Mem object which contains the
-    ** value SQL NULL. Even though the Mem structure contains an element
-    ** of type i64, on certain architecture (x86) with certain compiler
-    ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
-    ** instead of an 8-byte one. This all works fine, except that when
-    ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
-    ** that a Mem structure is located on an 8-byte boundary. To prevent
-    ** this assert() from failing, when building with SQLITE_DEBUG defined
-    ** using gcc, force nullMem to be 8-byte aligned using the magical
-    ** __attribute__((aligned(8))) macro.  */
-    static const Mem nullMem 
-#if defined(SQLITE_DEBUG) && defined(__GNUC__)
-      __attribute__((aligned(8))) 
-#endif
-      = {0, "", (double)0, {0}, 0, MEM_Null, SQLITE_NULL, 0,
-#ifdef SQLITE_DEBUG
-         0, 0,  /* pScopyFrom, pFiller */
-#endif
-         0, 0 };
-
     if( pVm && ALWAYS(pVm->db) ){
       sqlite3_mutex_enter(pVm->db->mutex);
-      sqlite3Error(pVm->db, SQLITE_RANGE, 0);
+      sqlite3Error(pVm->db, SQLITE_RANGE);
     }
-    pOut = (Mem*)&nullMem;
+    pOut = (Mem*)columnNullValue();
   }
   return pOut;
 }
@@ -62193,7 +75945,7 @@ static void columnMallocFailure(sqlite3_stmt *pStmt)
 ** The following routines are used to access elements of the current row
 ** in the result set.
 */
-SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
   const void *val;
   val = sqlite3_value_blob( columnMem(pStmt,i) );
   /* Even though there is no encoding conversion, value_blob() might
@@ -62203,37 +75955,37 @@ SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
+SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
   int val = sqlite3_value_bytes( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
+SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
+SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt *pStmt, int i){
   double val = sqlite3_value_double( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
+SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt *pStmt, int i){
   int val = sqlite3_value_int( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
+SQLITE_API sqlite_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
+SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt *pStmt, int i){
   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
-SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
+SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt *pStmt, int i){
   Mem *pOut = columnMem(pStmt, i);
   if( pOut->flags&MEM_Static ){
     pOut->flags &= ~MEM_Static;
@@ -62243,25 +75995,18 @@ SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
   return (sqlite3_value *)pOut;
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return val;
 }
 #endif /* SQLITE_OMIT_UTF16 */
-SQLITE_API int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
+SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt *pStmt, int i){
   int iType = sqlite3_value_type( columnMem(pStmt,i) );
   columnMallocFailure(pStmt);
   return iType;
 }
 
-/* The following function is experimental and subject to change or
-** removal */
-/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
-**  return sqlite3_value_numeric_type( columnMem(pStmt,i) );
-**}
-*/
-
 /*
 ** Convert the N-th element of pStmt->pColName[] into a string using
 ** xFunc() then return that string.  If N is out of range, return 0.
@@ -62284,11 +76029,19 @@ static const void *columnName(
   const void *(*xFunc)(Mem*),
   int useType
 ){
-  const void *ret = 0;
-  Vdbe *p = (Vdbe *)pStmt;
+  const void *ret;
+  Vdbe *p;
   int n;
-  sqlite3 *db = p->db;
-  
+  sqlite3 *db;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( pStmt==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  ret = 0;
+  p = (Vdbe *)pStmt;
+  db = p->db;
   assert( db!=0 );
   n = sqlite3_column_count(pStmt);
   if( N<n && N>=0 ){
@@ -62300,7 +76053,7 @@ static const void *columnName(
     ** is the case, clear the mallocFailed flag and return NULL.
     */
     if( db->mallocFailed ){
-      db->mallocFailed = 0;
+      sqlite3OomClear(db);
       ret = 0;
     }
     sqlite3_mutex_leave(db->mutex);
@@ -62312,12 +76065,12 @@ static const void *columnName(
 ** Return the name of the Nth column of the result set returned by SQL
 ** statement pStmt.
 */
-SQLITE_API const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_NAME);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_NAME);
 }
@@ -62337,12 +76090,12 @@ SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
 ** Return the column declaration type (if applicable) of the 'i'th column
 ** of the result set of SQL statement pStmt.
 */
-SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DECLTYPE);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DECLTYPE);
 }
@@ -62353,14 +76106,14 @@ SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
 /*
 ** Return the name of the database from which a result column derives.
 ** NULL is returned if the result column is an expression or constant or
-** anything else which is not an unabiguous reference to a database column.
+** anything else which is not an unambiguous reference to a database column.
 */
-SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DATABASE);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DATABASE);
 }
@@ -62369,14 +76122,14 @@ SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N
 /*
 ** Return the name of the table from which a result column derives.
 ** NULL is returned if the result column is an expression or constant or
-** anything else which is not an unabiguous reference to a database column.
+** anything else which is not an unambiguous reference to a database column.
 */
-SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_TABLE);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_TABLE);
 }
@@ -62385,14 +76138,14 @@ SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
 /*
 ** Return the name of the table column from which a result column derives.
 ** NULL is returned if the result column is an expression or constant or
-** anything else which is not an unabiguous reference to a database column.
+** anything else which is not an unambiguous reference to a database column.
 */
-SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_COLUMN);
 }
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
   return columnName(
       pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_COLUMN);
 }
@@ -62422,14 +76175,14 @@ static int vdbeUnbind(Vdbe *p, int i){
   }
   sqlite3_mutex_enter(p->db->mutex);
   if( p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){
-    sqlite3Error(p->db, SQLITE_MISUSE, 0);
+    sqlite3Error(p->db, SQLITE_MISUSE);
     sqlite3_mutex_leave(p->db->mutex);
     sqlite3_log(SQLITE_MISUSE, 
         "bind on a busy prepared statement: [%s]", p->zSql);
     return SQLITE_MISUSE_BKPT;
   }
   if( i<1 || i>p->nVar ){
-    sqlite3Error(p->db, SQLITE_RANGE, 0);
+    sqlite3Error(p->db, SQLITE_RANGE);
     sqlite3_mutex_leave(p->db->mutex);
     return SQLITE_RANGE;
   }
@@ -62437,7 +76190,7 @@ static int vdbeUnbind(Vdbe *p, int i){
   pVar = &p->aVar[i];
   sqlite3VdbeMemRelease(pVar);
   pVar->flags = MEM_Null;
-  sqlite3Error(p->db, SQLITE_OK, 0);
+  sqlite3Error(p->db, SQLITE_OK);
 
   /* If the bit corresponding to this variable in Vdbe.expmask is set, then 
   ** binding a new value to this variable invalidates the current query plan.
@@ -62479,7 +76232,7 @@ static int bindText(
       if( rc==SQLITE_OK && encoding!=0 ){
         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
       }
-      sqlite3Error(p->db, rc, 0);
+      sqlite3Error(p->db, rc);
       rc = sqlite3ApiExit(p->db, rc);
     }
     sqlite3_mutex_leave(p->db->mutex);
@@ -62493,16 +76246,33 @@ static int bindText(
 /*
 ** Bind a blob value to an SQL statement variable.
 */
-SQLITE_API int sqlite3_bind_blob(
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(
   sqlite3_stmt *pStmt, 
   int i, 
   const void *zData, 
   int nData, 
   void (*xDel)(void*)
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( nData<0 ) return SQLITE_MISUSE_BKPT;
+#endif
   return bindText(pStmt, i, zData, nData, xDel, 0);
 }
-SQLITE_API int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(
+  sqlite3_stmt *pStmt, 
+  int i, 
+  const void *zData, 
+  sqlite3_uint64 nData, 
+  void (*xDel)(void*)
+){
+  assert( xDel!=SQLITE_DYNAMIC );
+  if( nData>0x7fffffff ){
+    return invokeValueDestructor(zData, xDel, 0);
+  }else{
+    return bindText(pStmt, i, zData, (int)nData, xDel, 0);
+  }
+}
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
   int rc;
   Vdbe *p = (Vdbe *)pStmt;
   rc = vdbeUnbind(p, i);
@@ -62512,10 +76282,10 @@ SQLITE_API int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
   }
   return rc;
 }
-SQLITE_API int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
   return sqlite3_bind_int64(p, i, (i64)iValue);
 }
-SQLITE_API int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
   int rc;
   Vdbe *p = (Vdbe *)pStmt;
   rc = vdbeUnbind(p, i);
@@ -62525,7 +76295,7 @@ SQLITE_API int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValu
   }
   return rc;
 }
-SQLITE_API int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
   int rc;
   Vdbe *p = (Vdbe*)pStmt;
   rc = vdbeUnbind(p, i);
@@ -62534,7 +76304,7 @@ SQLITE_API int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
   }
   return rc;
 }
-SQLITE_API int sqlite3_bind_text( 
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text( 
   sqlite3_stmt *pStmt, 
   int i, 
   const char *zData, 
@@ -62543,8 +76313,24 @@ SQLITE_API int sqlite3_bind_text(
 ){
   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
 }
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64( 
+  sqlite3_stmt *pStmt, 
+  int i, 
+  const char *zData, 
+  sqlite3_uint64 nData, 
+  void (*xDel)(void*),
+  unsigned char enc
+){
+  assert( xDel!=SQLITE_DYNAMIC );
+  if( nData>0x7fffffff ){
+    return invokeValueDestructor(zData, xDel, 0);
+  }else{
+    if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
+    return bindText(pStmt, i, zData, (int)nData, xDel, enc);
+  }
+}
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API int sqlite3_bind_text16(
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(
   sqlite3_stmt *pStmt, 
   int i, 
   const void *zData, 
@@ -62554,15 +76340,15 @@ SQLITE_API int sqlite3_bind_text16(
   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
 }
 #endif /* SQLITE_OMIT_UTF16 */
-SQLITE_API int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
   int rc;
-  switch( pValue->type ){
+  switch( sqlite3_value_type((sqlite3_value*)pValue) ){
     case SQLITE_INTEGER: {
       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);
       break;
     }
     case SQLITE_FLOAT: {
-      rc = sqlite3_bind_double(pStmt, i, pValue->r);
+      rc = sqlite3_bind_double(pStmt, i, pValue->u.r);
       break;
     }
     case SQLITE_BLOB: {
@@ -62585,7 +76371,7 @@ SQLITE_API int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_valu
   }
   return rc;
 }
-SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
   int rc;
   Vdbe *p = (Vdbe *)pStmt;
   rc = vdbeUnbind(p, i);
@@ -62595,12 +76381,26 @@ SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
   }
   return rc;
 }
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
+  int rc;
+  Vdbe *p = (Vdbe *)pStmt;
+  sqlite3_mutex_enter(p->db->mutex);
+  if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    rc = SQLITE_TOOBIG;
+  }else{
+    assert( (n & 0x7FFFFFFF)==n );
+    rc = sqlite3_bind_zeroblob(pStmt, i, n);
+  }
+  rc = sqlite3ApiExit(p->db, rc);
+  sqlite3_mutex_leave(p->db->mutex);
+  return rc;
+}
 
 /*
 ** Return the number of wildcards that can be potentially bound to.
 ** This routine is added to support DBD::SQLite.  
 */
-SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
   Vdbe *p = (Vdbe*)pStmt;
   return p ? p->nVar : 0;
 }
@@ -62611,7 +76411,7 @@ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
 **
 ** The result is always UTF-8.
 */
-SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
   Vdbe *p = (Vdbe*)pStmt;
   if( p==0 || i<1 || i>p->nzVar ){
     return 0;
@@ -62632,14 +76432,14 @@ SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nNa
   if( zName ){
     for(i=0; i<p->nzVar; i++){
       const char *z = p->azVar[i];
-      if( z && memcmp(z,zName,nName)==0 && z[nName]==0 ){
+      if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
         return i+1;
       }
     }
   }
   return 0;
 }
-SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
+SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
 }
 
@@ -62665,7 +76465,7 @@ SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt
 ** Deprecated external interface.  Internal/core SQLite code
 ** should call sqlite3TransferBindings.
 **
-** Is is misuse to call this routine with statements from different
+** It is misuse to call this routine with statements from different
 ** database connections.  But as this is a deprecated interface, we
 ** will not bother to check for that condition.
 **
@@ -62673,7 +76473,7 @@ SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt
 ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
 ** SQLITE_OK is returned.
 */
-SQLITE_API int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
   Vdbe *pFrom = (Vdbe*)pFromStmt;
   Vdbe *pTo = (Vdbe*)pToStmt;
   if( pFrom->nVar!=pTo->nVar ){
@@ -62695,7 +76495,7 @@ SQLITE_API int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *
 ** the first argument to the sqlite3_prepare() that was used to create
 ** the statement in the first place.
 */
-SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt *pStmt){
   return pStmt ? ((Vdbe*)pStmt)->db : 0;
 }
 
@@ -62703,18 +76503,32 @@ SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
 ** Return true if the prepared statement is guaranteed to not modify the
 ** database.
 */
-SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
 }
 
 /*
+** Return true if the prepared statement is in need of being reset.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt *pStmt){
+  Vdbe *v = (Vdbe*)pStmt;
+  return v!=0 && v->pc>=0 && v->magic==VDBE_MAGIC_RUN;
+}
+
+/*
 ** Return a pointer to the next prepared statement after pStmt associated
 ** with database connection pDb.  If pStmt is NULL, return the first
 ** prepared statement for the database connection.  Return NULL if there
 ** are no more.
 */
-SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
+SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
   sqlite3_stmt *pNext;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(pDb) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(pDb->mutex);
   if( pStmt==0 ){
     pNext = (sqlite3_stmt*)pDb->pVdbe;
@@ -62728,13 +76542,302 @@ SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
 /*
 ** Return the value of a status counter for a prepared statement
 */
-SQLITE_API int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
   Vdbe *pVdbe = (Vdbe*)pStmt;
-  int v = pVdbe->aCounter[op-1];
-  if( resetFlag ) pVdbe->aCounter[op-1] = 0;
-  return v;
+  u32 v;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !pStmt ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  v = pVdbe->aCounter[op];
+  if( resetFlag ) pVdbe->aCounter[op] = 0;
+  return (int)v;
+}
+
+/*
+** Return the SQL associated with a prepared statement
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe *)pStmt;
+  return p ? p->zSql : 0;
+}
+
+/*
+** Return the SQL associated with a prepared statement with
+** bound parameters expanded.  Space to hold the returned string is
+** obtained from sqlite3_malloc().  The caller is responsible for
+** freeing the returned string by passing it to sqlite3_free().
+**
+** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
+** expanded bound parameters.
+*/
+SQLITE_API char *SQLITE_STDCALL sqlite3_expanded_sql(sqlite3_stmt *pStmt){
+#ifdef SQLITE_OMIT_TRACE
+  return 0;
+#else
+  char *z = 0;
+  const char *zSql = sqlite3_sql(pStmt);
+  if( zSql ){
+    Vdbe *p = (Vdbe *)pStmt;
+    sqlite3_mutex_enter(p->db->mutex);
+    z = sqlite3VdbeExpandSql(p, zSql);
+    sqlite3_mutex_leave(p->db->mutex);
+  }
+  return z;
+#endif
 }
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Allocate and populate an UnpackedRecord structure based on the serialized
+** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
+** if successful, or a NULL pointer if an OOM error is encountered.
+*/
+static UnpackedRecord *vdbeUnpackRecord(
+  KeyInfo *pKeyInfo, 
+  int nKey, 
+  const void *pKey
+){
+  char *dummy;                    /* Dummy argument for AllocUnpackedRecord() */
+  UnpackedRecord *pRet;           /* Return value */
+
+  pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo, 0, 0, &dummy);
+  if( pRet ){
+    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1));
+    sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
+  }
+  return pRet;
+}
+
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or deleted.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+
+  /* Test that this call is being made from within an SQLITE_DELETE or
+  ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
+  if( !p || p->op==SQLITE_INSERT ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_old_out;
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_old_out;
+  }
+
+  /* If the old.* record has not yet been loaded into memory, do so now. */
+  if( p->pUnpacked==0 ){
+    u32 nRec;
+    u8 *aRec;
+
+    nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
+    aRec = sqlite3DbMallocRaw(db, nRec);
+    if( !aRec ) goto preupdate_old_out;
+    rc = sqlite3BtreeData(p->pCsr->uc.pCursor, 0, nRec, aRec);
+    if( rc==SQLITE_OK ){
+      p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
+      if( !p->pUnpacked ) rc = SQLITE_NOMEM;
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, aRec);
+      goto preupdate_old_out;
+    }
+    p->aRecord = aRec;
+  }
+
+  if( iIdx>=p->pUnpacked->nField ){
+    *ppValue = (sqlite3_value *)columnNullValue();
+  }else{
+    *ppValue = &p->pUnpacked->aMem[iIdx];
+    if( iIdx==p->iPKey ){
+      sqlite3VdbeMemSetInt64(*ppValue, p->iKey1);
+    }
+  }
+
+ preupdate_old_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** the number of columns in the row being updated, deleted or inserted.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_preupdate_count(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->keyinfo.nField : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is designed to be called from within a pre-update callback
+** only. It returns zero if the change that caused the callback was made
+** immediately by a user SQL statement. Or, if the change was made by a
+** trigger program, it returns the number of trigger programs currently
+** on the stack (1 for a top-level trigger, 2 for a trigger fired by a 
+** top-level trigger etc.).
+**
+** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
+** or SET DEFAULT action is considered a trigger.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_preupdate_depth(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->v->nFrame : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or inserted.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+  Mem *pMem;
+
+  if( !p || p->op==SQLITE_DELETE ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_new_out;
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_new_out;
+  }
+
+  if( p->op==SQLITE_INSERT ){
+    /* For an INSERT, memory cell p->iNewReg contains the serialized record
+    ** that is being inserted. Deserialize it. */
+    UnpackedRecord *pUnpack = p->pNewUnpacked;
+    if( !pUnpack ){
+      Mem *pData = &p->v->aMem[p->iNewReg];
+      rc = sqlite3VdbeMemExpandBlob(pData);
+      if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
+      if( !pUnpack ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+      p->pNewUnpacked = pUnpack;
+    }
+    if( iIdx>=pUnpack->nField ){
+      pMem = (sqlite3_value *)columnNullValue();
+    }else{
+      pMem = &pUnpack->aMem[iIdx];
+      if( iIdx==p->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }
+    }
+  }else{
+    /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
+    ** value. Make a copy of the cell contents and return a pointer to it.
+    ** It is not safe to return a pointer to the memory cell itself as the
+    ** caller may modify the value text encoding.
+    */
+    assert( p->op==SQLITE_UPDATE );
+    if( !p->aNew ){
+      p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
+      if( !p->aNew ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+    }
+    assert( iIdx>=0 && iIdx<p->pCsr->nField );
+    pMem = &p->aNew[iIdx];
+    if( pMem->flags==0 ){
+      if( iIdx==p->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }else{
+        rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
+        if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      }
+    }
+  }
+  *ppValue = pMem;
+
+ preupdate_new_out:
+  sqlite3Error(db, rc);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+/*
+** Return status data for a single loop within query pStmt.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus(
+  sqlite3_stmt *pStmt,            /* Prepared statement being queried */
+  int idx,                        /* Index of loop to report on */
+  int iScanStatusOp,              /* Which metric to return */
+  void *pOut                      /* OUT: Write the answer here */
+){
+  Vdbe *p = (Vdbe*)pStmt;
+  ScanStatus *pScan;
+  if( idx<0 || idx>=p->nScan ) return 1;
+  pScan = &p->aScan[idx];
+  switch( iScanStatusOp ){
+    case SQLITE_SCANSTAT_NLOOP: {
+      *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
+      break;
+    }
+    case SQLITE_SCANSTAT_NVISIT: {
+      *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
+      break;
+    }
+    case SQLITE_SCANSTAT_EST: {
+      double r = 1.0;
+      LogEst x = pScan->nEst;
+      while( x<100 ){
+        x += 10;
+        r *= 0.5;
+      }
+      *(double*)pOut = r*sqlite3LogEstToInt(x);
+      break;
+    }
+    case SQLITE_SCANSTAT_NAME: {
+      *(const char**)pOut = pScan->zName;
+      break;
+    }
+    case SQLITE_SCANSTAT_EXPLAIN: {
+      if( pScan->addrExplain ){
+        *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
+      }else{
+        *(const char**)pOut = 0;
+      }
+      break;
+    }
+    case SQLITE_SCANSTAT_SELECTID: {
+      if( pScan->addrExplain ){
+        *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
+      }else{
+        *(int*)pOut = -1;
+      }
+      break;
+    }
+    default: {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
+  Vdbe *p = (Vdbe*)pStmt;
+  memset(p->anExec, 0, p->nOp * sizeof(i64));
+}
+#endif /* SQLITE_ENABLE_STMT_SCANSTATUS */
+
 /************** End of vdbeapi.c *********************************************/
 /************** Begin file vdbetrace.c ***************************************/
 /*
@@ -62751,7 +76854,11 @@ SQLITE_API int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
 **
 ** This file contains code used to insert the values of host parameters
 ** (aka "wildcards") into the SQL text output by sqlite3_trace().
+**
+** The Vdbe parse-tree explainer is also found here.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_TRACE
 
@@ -62782,19 +76889,24 @@ static int findNextHostParameter(const char *zSql, int *pnToken){
 
 /*
 ** This function returns a pointer to a nul-terminated string in memory
-** obtained from sqlite3DbMalloc(). If sqlite3.vdbeExecCnt is 1, then the
+** obtained from sqlite3DbMalloc(). If sqlite3.nVdbeExec is 1, then the
 ** string contains a copy of zRawSql but with host parameters expanded to 
-** their current bindings. Or, if sqlite3.vdbeExecCnt is greater than 1, 
+** their current bindings. Or, if sqlite3.nVdbeExec is greater than 1, 
 ** then the returned string holds a copy of zRawSql with "-- " prepended
 ** to each line of text.
 **
+** If the SQLITE_TRACE_SIZE_LIMIT macro is defined to an integer, then
+** then long strings and blobs are truncated to that many bytes.  This
+** can be used to prevent unreasonably large trace strings when dealing
+** with large (multi-megabyte) strings and blobs.
+**
 ** The calling function is responsible for making sure the memory returned
 ** is eventually freed.
 **
 ** ALGORITHM:  Scan the input string looking for host parameters in any of
 ** these forms:  ?, ?N, $A, @A, :A.  Take care to avoid text within
 ** string literals, quoted identifier names, and comments.  For text forms,
-** the host parameter index is found by scanning the perpared
+** the host parameter index is found by scanning the prepared
 ** statement for the corresponding OP_Variable opcode.  Once the host
 ** parameter index is known, locate the value in p->aVar[].  Then render
 ** the value as a literal in place of the host parameter name.
@@ -62811,19 +76923,24 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
   int i;                   /* Loop counter */
   Mem *pVar;               /* Value of a host parameter */
   StrAccum out;            /* Accumulate the output here */
+#ifndef SQLITE_OMIT_UTF16
+  Mem utf8;                /* Used to convert UTF16 parameters into UTF8 for display */
+#endif
   char zBase[100];         /* Initial working space */
 
   db = p->db;
-  sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
+  sqlite3StrAccumInit(&out, 0, zBase, sizeof(zBase), 
                       db->aLimit[SQLITE_LIMIT_LENGTH]);
-  out.db = db;
-  if( db->vdbeExecCnt>1 ){
+  if( db->nVdbeExec>1 ){
     while( *zRawSql ){
       const char *zStart = zRawSql;
       while( *(zRawSql++)!='\n' && *zRawSql );
       sqlite3StrAccumAppend(&out, "-- ", 3);
+      assert( (zRawSql - zStart) > 0 );
       sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart));
     }
+  }else if( p->nVar==0 ){
+    sqlite3StrAccumAppend(&out, zRawSql, sqlite3Strlen30(zRawSql));
   }else{
     while( zRawSql[0] ){
       n = findNextHostParameter(zRawSql, &nToken);
@@ -62840,10 +76957,12 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
           idx = nextIndex;
         }
       }else{
-        assert( zRawSql[0]==':' || zRawSql[0]=='$' || zRawSql[0]=='@' );
+        assert( zRawSql[0]==':' || zRawSql[0]=='$' ||
+                zRawSql[0]=='@' || zRawSql[0]=='#' );
         testcase( zRawSql[0]==':' );
         testcase( zRawSql[0]=='$' );
         testcase( zRawSql[0]=='@' );
+        testcase( zRawSql[0]=='#' );
         idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken);
         assert( idx>0 );
       }
@@ -62856,35 +76975,61 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
       }else if( pVar->flags & MEM_Int ){
         sqlite3XPrintf(&out, "%lld", pVar->u.i);
       }else if( pVar->flags & MEM_Real ){
-        sqlite3XPrintf(&out, "%!.15g", pVar->r);
+        sqlite3XPrintf(&out, "%!.15g", pVar->u.r);
       }else if( pVar->flags & MEM_Str ){
+        int nOut;  /* Number of bytes of the string text to include in output */
 #ifndef SQLITE_OMIT_UTF16
         u8 enc = ENC(db);
         if( enc!=SQLITE_UTF8 ){
-          Mem utf8;
           memset(&utf8, 0, sizeof(utf8));
           utf8.db = db;
           sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
-          sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
-          sqlite3XPrintf(&out, "'%.*q'", utf8.n, utf8.z);
-          sqlite3VdbeMemRelease(&utf8);
-        }else
+          if( SQLITE_NOMEM==sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8) ){
+            out.accError = STRACCUM_NOMEM;
+            out.nAlloc = 0;
+          }
+          pVar = &utf8;
+        }
 #endif
-        {
-          sqlite3XPrintf(&out, "'%.*q'", pVar->n, pVar->z);
+        nOut = pVar->n;
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut>SQLITE_TRACE_SIZE_LIMIT ){
+          nOut = SQLITE_TRACE_SIZE_LIMIT;
+          while( nOut<pVar->n && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; }
+        }
+#endif    
+        sqlite3XPrintf(&out, "'%.*q'", nOut, pVar->z);
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut<pVar->n ){
+          sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
         }
+#endif
+#ifndef SQLITE_OMIT_UTF16
+        if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8);
+#endif
       }else if( pVar->flags & MEM_Zero ){
         sqlite3XPrintf(&out, "zeroblob(%d)", pVar->u.nZero);
       }else{
+        int nOut;  /* Number of bytes of the blob to include in output */
         assert( pVar->flags & MEM_Blob );
         sqlite3StrAccumAppend(&out, "x'", 2);
-        for(i=0; i<pVar->n; i++){
+        nOut = pVar->n;
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT;
+#endif
+        for(i=0; i<nOut; i++){
           sqlite3XPrintf(&out, "%02x", pVar->z[i]&0xff);
         }
         sqlite3StrAccumAppend(&out, "'", 1);
+#ifdef SQLITE_TRACE_SIZE_LIMIT
+        if( nOut<pVar->n ){
+          sqlite3XPrintf(&out, "/*+%d bytes*/", pVar->n-nOut);
+        }
+#endif
       }
     }
   }
+  if( out.accError ) sqlite3StrAccumReset(&out);
   return sqlite3StrAccumFinish(&out);
 }
 
@@ -62903,33 +77048,8 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** The code in this file implements execution method of the 
-** Virtual Database Engine (VDBE).  A separate file ("vdbeaux.c")
-** handles housekeeping details such as creating and deleting
-** VDBE instances.  This file is solely interested in executing
-** the VDBE program.
-**
-** In the external interface, an "sqlite3_stmt*" is an opaque pointer
-** to a VDBE.
-**
-** The SQL parser generates a program which is then executed by
-** the VDBE to do the work of the SQL statement.  VDBE programs are 
-** similar in form to assembly language.  The program consists of
-** a linear sequence of operations.  Each operation has an opcode 
-** and 5 operands.  Operands P1, P2, and P3 are integers.  Operand P4 
-** is a null-terminated string.  Operand P5 is an unsigned character.
-** Few opcodes use all 5 operands.
-**
-** Computation results are stored on a set of registers numbered beginning
-** with 1 and going up to Vdbe.nMem.  Each register can store
-** either an integer, a null-terminated string, a floating point
-** number, or the SQL "NULL" value.  An implicit conversion from one
-** type to the other occurs as necessary.
-** 
-** Most of the code in this file is taken up by the sqlite3VdbeExec()
-** function which does the work of interpreting a VDBE program.
-** But other routines are also provided to help in building up
-** a program instruction by instruction.
+** The code in this file implements the function that runs the
+** bytecode of a prepared statement.
 **
 ** Various scripts scan this source file in order to generate HTML
 ** documentation, headers files, or other derived files.  The formatting
@@ -62937,14 +77057,20 @@ SQLITE_PRIVATE char *sqlite3VdbeExpandSql(
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 /*
 ** Invoke this macro on memory cells just prior to changing the
 ** value of the cell.  This macro verifies that shallow copies are
-** not misused.
+** not misused.  A shallow copy of a string or blob just copies a
+** pointer to the string or blob, not the content.  If the original
+** is changed while the copy is still in use, the string or blob might
+** be changed out from under the copy.  This macro verifies that nothing
+** like that ever happens.
 */
 #ifdef SQLITE_DEBUG
-# define memAboutToChange(P,M) sqlite3VdbeMemPrepareToChange(P,M)
+# define memAboutToChange(P,M) sqlite3VdbeMemAboutToChange(P,M)
 #else
 # define memAboutToChange(P,M)
 #endif
@@ -62962,8 +77088,8 @@ SQLITE_API int sqlite3_search_count = 0;
 
 /*
 ** When this global variable is positive, it gets decremented once before
-** each instruction in the VDBE.  When reaches zero, the u1.isInterrupted
-** field of the sqlite3 structure is set in order to simulate and interrupt.
+** each instruction in the VDBE.  When it reaches zero, the u1.isInterrupted
+** field of the sqlite3 structure is set in order to simulate an interrupt.
 **
 ** This facility is used for testing purposes only.  It does not function
 ** in an ordinary build.
@@ -63000,7 +77126,17 @@ static void updateMaxBlobsize(Mem *p){
 #endif
 
 /*
-** The next global variable is incremented each type the OP_Found opcode
+** This macro evaluates to true if either the update hook or the preupdate
+** hook are enabled for database connect DB.
+*/
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+# define HAS_UPDATE_HOOK(DB) ((DB)->xPreUpdateCallback||(DB)->xUpdateCallback)
+#else
+# define HAS_UPDATE_HOOK(DB) ((DB)->xUpdateCallback)
+#endif
+
+/*
+** The next global variable is incremented each time the OP_Found opcode
 ** is executed. This is used to test whether or not the foreign key
 ** operation implemented using OP_FkIsZero is working. This variable
 ** has no function other than to help verify the correct operation of the
@@ -63021,11 +77157,45 @@ SQLITE_API int sqlite3_found_count = 0;
 #endif
 
 /*
+** Invoke the VDBE coverage callback, if that callback is defined.  This
+** feature is used for test suite validation only and does not appear an
+** production builds.
+**
+** M is an integer, 2 or 3, that indices how many different ways the
+** branch can go.  It is usually 2.  "I" is the direction the branch
+** goes.  0 means falls through.  1 means branch is taken.  2 means the
+** second alternative branch is taken.
+**
+** iSrcLine is the source code line (from the __LINE__ macro) that
+** generated the VDBE instruction.  This instrumentation assumes that all
+** source code is in a single file (the amalgamation).  Special values 1
+** and 2 for the iSrcLine parameter mean that this particular branch is
+** always taken or never taken, respectively.
+*/
+#if !defined(SQLITE_VDBE_COVERAGE)
+# define VdbeBranchTaken(I,M)
+#else
+# define VdbeBranchTaken(I,M) vdbeTakeBranch(pOp->iSrcLine,I,M)
+  static void vdbeTakeBranch(int iSrcLine, u8 I, u8 M){
+    if( iSrcLine<=2 && ALWAYS(iSrcLine>0) ){
+      M = iSrcLine;
+      /* Assert the truth of VdbeCoverageAlwaysTaken() and 
+      ** VdbeCoverageNeverTaken() */
+      assert( (M & I)==I );
+    }else{
+      if( sqlite3GlobalConfig.xVdbeBranch==0 ) return;  /*NO_TEST*/
+      sqlite3GlobalConfig.xVdbeBranch(sqlite3GlobalConfig.pVdbeBranchArg,
+                                      iSrcLine,I,M);
+    }
+  }
+#endif
+
+/*
 ** Convert the given register into a string if it isn't one
 ** already. Return non-zero if a malloc() fails.
 */
 #define Stringify(P, enc) \
-   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
+   if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc,0)) \
      { goto no_mem; }
 
 /*
@@ -63037,48 +77207,14 @@ SQLITE_API int sqlite3_found_count = 0;
 **
 ** This routine converts an ephemeral string into a dynamically allocated
 ** string that the register itself controls.  In other words, it
-** converts an MEM_Ephem string into an MEM_Dyn string.
+** converts an MEM_Ephem string into a string with P.z==P.zMalloc.
 */
 #define Deephemeralize(P) \
    if( ((P)->flags&MEM_Ephem)!=0 \
        && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
 
-/*
-** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
-** P if required.
-*/
-#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
-
 /* Return true if the cursor was opened using the OP_OpenSorter opcode. */
-#ifdef SQLITE_OMIT_MERGE_SORT
-# define isSorter(x) 0
-#else
-# define isSorter(x) ((x)->pSorter!=0)
-#endif
-
-/*
-** Argument pMem points at a register that will be passed to a
-** user-defined function or returned to the user as the result of a query.
-** This routine sets the pMem->type variable used by the sqlite3_value_*() 
-** routines.
-*/
-SQLITE_PRIVATE void sqlite3VdbeMemStoreType(Mem *pMem){
-  int flags = pMem->flags;
-  if( flags & MEM_Null ){
-    pMem->type = SQLITE_NULL;
-  }
-  else if( flags & MEM_Int ){
-    pMem->type = SQLITE_INTEGER;
-  }
-  else if( flags & MEM_Real ){
-    pMem->type = SQLITE_FLOAT;
-  }
-  else if( flags & MEM_Str ){
-    pMem->type = SQLITE_TEXT;
-  }else{
-    pMem->type = SQLITE_BLOB;
-  }
-}
+#define isSorter(x) ((x)->eCurType==CURTYPE_SORTER)
 
 /*
 ** Allocate VdbeCursor number iCur.  Return a pointer to it.  Return NULL
@@ -63088,8 +77224,8 @@ static VdbeCursor *allocateCursor(
   Vdbe *p,              /* The virtual machine */
   int iCur,             /* Index of the new VdbeCursor */
   int nField,           /* Number of fields in the table or index */
-  int iDb,              /* When database the cursor belongs to, or -1 */
-  int isBtreeCursor     /* True for B-Tree.  False for pseudo-table or vtab */
+  int iDb,              /* Database the cursor belongs to, or -1 */
+  u8 eCurType           /* Type of the new cursor */
 ){
   /* Find the memory cell that will be used to store the blob of memory
   ** required for this VdbeCursor structure. It is convenient to use a 
@@ -63105,36 +77241,34 @@ static VdbeCursor *allocateCursor(
   **     be freed lazily via the sqlite3_release_memory() API. This
   **     minimizes the number of malloc calls made by the system.
   **
-  ** Memory cells for cursors are allocated at the top of the address
-  ** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
-  ** cursor 1 is managed by memory cell (p->nMem-1), etc.
+  ** The memory cell for cursor 0 is aMem[0]. The rest are allocated from
+  ** the top of the register space.  Cursor 1 is at Mem[p->nMem-1].
+  ** Cursor 2 is at Mem[p->nMem-2]. And so forth.
   */
-  Mem *pMem = &p->aMem[p->nMem-iCur];
+  Mem *pMem = iCur>0 ? &p->aMem[p->nMem-iCur] : p->aMem;
 
   int nByte;
   VdbeCursor *pCx = 0;
   nByte = 
-      ROUND8(sizeof(VdbeCursor)) + 
-      (isBtreeCursor?sqlite3BtreeCursorSize():0) + 
-      2*nField*sizeof(u32);
+      ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
+      (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);
 
-  assert( iCur<p->nCursor );
-  if( p->apCsr[iCur] ){
+  assert( iCur>=0 && iCur<p->nCursor );
+  if( p->apCsr[iCur] ){ /*OPTIMIZATION-IF-FALSE*/
     sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
     p->apCsr[iCur] = 0;
   }
-  if( SQLITE_OK==sqlite3VdbeMemGrow(pMem, nByte, 0) ){
+  if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){
     p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
     memset(pCx, 0, sizeof(VdbeCursor));
+    pCx->eCurType = eCurType;
     pCx->iDb = iDb;
     pCx->nField = nField;
-    if( nField ){
-      pCx->aType = (u32 *)&pMem->z[ROUND8(sizeof(VdbeCursor))];
-    }
-    if( isBtreeCursor ){
-      pCx->pCursor = (BtCursor*)
-          &pMem->z[ROUND8(sizeof(VdbeCursor))+2*nField*sizeof(u32)];
-      sqlite3BtreeCursorZero(pCx->pCursor);
+    pCx->aOffset = &pCx->aType[nField];
+    if( eCurType==CURTYPE_BTREE ){
+      pCx->uc.pCursor = (BtCursor*)
+          &pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];
+      sqlite3BtreeCursorZero(pCx->uc.pCursor);
     }
   }
   return pCx;
@@ -63145,21 +77279,29 @@ static VdbeCursor *allocateCursor(
 ** do so without loss of information.  In other words, if the string
 ** looks like a number, convert it into a number.  If it does not
 ** look like a number, leave it alone.
-*/
-static void applyNumericAffinity(Mem *pRec){
-  if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
-    double rValue;
-    i64 iValue;
-    u8 enc = pRec->enc;
-    if( (pRec->flags&MEM_Str)==0 ) return;
-    if( sqlite3AtoF(pRec->z, &rValue, pRec->n, enc)==0 ) return;
-    if( 0==sqlite3Atoi64(pRec->z, &iValue, pRec->n, enc) ){
-      pRec->u.i = iValue;
-      pRec->flags |= MEM_Int;
-    }else{
-      pRec->r = rValue;
-      pRec->flags |= MEM_Real;
-    }
+**
+** If the bTryForInt flag is true, then extra effort is made to give
+** an integer representation.  Strings that look like floating point
+** values but which have no fractional component (example: '48.00')
+** will have a MEM_Int representation when bTryForInt is true.
+**
+** If bTryForInt is false, then if the input string contains a decimal
+** point or exponential notation, the result is only MEM_Real, even
+** if there is an exact integer representation of the quantity.
+*/
+static void applyNumericAffinity(Mem *pRec, int bTryForInt){
+  double rValue;
+  i64 iValue;
+  u8 enc = pRec->enc;
+  assert( (pRec->flags & (MEM_Str|MEM_Int|MEM_Real))==MEM_Str );
+  if( sqlite3AtoF(pRec->z, &rValue, pRec->n, enc)==0 ) return;
+  if( 0==sqlite3Atoi64(pRec->z, &iValue, pRec->n, enc) ){
+    pRec->u.i = iValue;
+    pRec->flags |= MEM_Int;
+  }else{
+    pRec->u.r = rValue;
+    pRec->flags |= MEM_Real;
+    if( bTryForInt ) sqlite3VdbeIntegerAffinity(pRec);
   }
 }
 
@@ -63178,7 +77320,7 @@ static void applyNumericAffinity(Mem *pRec){
 ** SQLITE_AFF_TEXT:
 **    Convert pRec to a text representation.
 **
-** SQLITE_AFF_NONE:
+** SQLITE_AFF_BLOB:
 **    No-op.  pRec is unchanged.
 */
 static void applyAffinity(
@@ -63186,22 +77328,28 @@ static void applyAffinity(
   char affinity,      /* The affinity to be applied */
   u8 enc              /* Use this text encoding */
 ){
-  if( affinity==SQLITE_AFF_TEXT ){
+  if( affinity>=SQLITE_AFF_NUMERIC ){
+    assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
+             || affinity==SQLITE_AFF_NUMERIC );
+    if( (pRec->flags & MEM_Int)==0 ){ /*OPTIMIZATION-IF-FALSE*/
+      if( (pRec->flags & MEM_Real)==0 ){
+        if( pRec->flags & MEM_Str ) applyNumericAffinity(pRec,1);
+      }else{
+        sqlite3VdbeIntegerAffinity(pRec);
+      }
+    }
+  }else if( affinity==SQLITE_AFF_TEXT ){
     /* Only attempt the conversion to TEXT if there is an integer or real
     ** representation (blob and NULL do not get converted) but no string
-    ** representation.
-    */
-    if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
-      sqlite3VdbeMemStringify(pRec, enc);
+    ** representation.  It would be harmless to repeat the conversion if 
+    ** there is already a string rep, but it is pointless to waste those
+    ** CPU cycles. */
+    if( 0==(pRec->flags&MEM_Str) ){ /*OPTIMIZATION-IF-FALSE*/
+      if( (pRec->flags&(MEM_Real|MEM_Int)) ){
+        sqlite3VdbeMemStringify(pRec, enc, 1);
+      }
     }
     pRec->flags &= ~(MEM_Real|MEM_Int);
-  }else if( affinity!=SQLITE_AFF_NONE ){
-    assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
-             || affinity==SQLITE_AFF_NUMERIC );
-    applyNumericAffinity(pRec);
-    if( pRec->flags & MEM_Real ){
-      sqlite3VdbeIntegerAffinity(pRec);
-    }
   }
 }
 
@@ -63211,13 +77359,14 @@ static void applyAffinity(
 ** is appropriate.  But only do the conversion if it is possible without
 ** loss of information and return the revised type of the argument.
 */
-SQLITE_API int sqlite3_value_numeric_type(sqlite3_value *pVal){
-  Mem *pMem = (Mem*)pVal;
-  if( pMem->type==SQLITE_TEXT ){
-    applyNumericAffinity(pMem);
-    sqlite3VdbeMemStoreType(pMem);
+SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value *pVal){
+  int eType = sqlite3_value_type(pVal);
+  if( eType==SQLITE_TEXT ){
+    Mem *pMem = (Mem*)pVal;
+    applyNumericAffinity(pMem, 0);
+    eType = sqlite3_value_type(pVal);
   }
-  return pMem->type;
+  return eType;
 }
 
 /*
@@ -63232,6 +77381,41 @@ SQLITE_PRIVATE void sqlite3ValueApplyAffinity(
   applyAffinity((Mem *)pVal, affinity, enc);
 }
 
+/*
+** pMem currently only holds a string type (or maybe a BLOB that we can
+** interpret as a string if we want to).  Compute its corresponding
+** numeric type, if has one.  Set the pMem->u.r and pMem->u.i fields
+** accordingly.
+*/
+static u16 SQLITE_NOINLINE computeNumericType(Mem *pMem){
+  assert( (pMem->flags & (MEM_Int|MEM_Real))==0 );
+  assert( (pMem->flags & (MEM_Str|MEM_Blob))!=0 );
+  if( sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc)==0 ){
+    return 0;
+  }
+  if( sqlite3Atoi64(pMem->z, &pMem->u.i, pMem->n, pMem->enc)==SQLITE_OK ){
+    return MEM_Int;
+  }
+  return MEM_Real;
+}
+
+/*
+** Return the numeric type for pMem, either MEM_Int or MEM_Real or both or
+** none.  
+**
+** Unlike applyNumericAffinity(), this routine does not modify pMem->flags.
+** But it does set pMem->u.r and pMem->u.i appropriately.
+*/
+static u16 numericType(Mem *pMem){
+  if( pMem->flags & (MEM_Int|MEM_Real) ){
+    return pMem->flags & (MEM_Int|MEM_Real);
+  }
+  if( pMem->flags & (MEM_Str|MEM_Blob) ){
+    return computeNumericType(pMem);
+  }
+  return 0;
+}
+
 #ifdef SQLITE_DEBUG
 /*
 ** Write a nice string representation of the contents of cell pMem
@@ -63319,35 +77503,37 @@ SQLITE_PRIVATE void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
 /*
 ** Print the value of a register for tracing purposes:
 */
-static void memTracePrint(FILE *out, Mem *p){
-  if( p->flags & MEM_Null ){
-    fprintf(out, " NULL");
+static void memTracePrint(Mem *p){
+  if( p->flags & MEM_Undefined ){
+    printf(" undefined");
+  }else if( p->flags & MEM_Null ){
+    printf(" NULL");
   }else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
-    fprintf(out, " si:%lld", p->u.i);
+    printf(" si:%lld", p->u.i);
   }else if( p->flags & MEM_Int ){
-    fprintf(out, " i:%lld", p->u.i);
+    printf(" i:%lld", p->u.i);
 #ifndef SQLITE_OMIT_FLOATING_POINT
   }else if( p->flags & MEM_Real ){
-    fprintf(out, " r:%g", p->r);
+    printf(" r:%g", p->u.r);
 #endif
   }else if( p->flags & MEM_RowSet ){
-    fprintf(out, " (rowset)");
+    printf(" (rowset)");
   }else{
     char zBuf[200];
     sqlite3VdbeMemPrettyPrint(p, zBuf);
-    fprintf(out, " ");
-    fprintf(out, "%s", zBuf);
+    printf(" %s", zBuf);
   }
+  if( p->flags & MEM_Subtype ) printf(" subtype=0x%02x", p->eSubtype);
 }
-static void registerTrace(FILE *out, int iReg, Mem *p){
-  fprintf(out, "REG[%d] = ", iReg);
-  memTracePrint(out, p);
-  fprintf(out, "\n");
+static void registerTrace(int iReg, Mem *p){
+  printf("REG[%d] = ", iReg);
+  memTracePrint(p);
+  printf("\n");
 }
 #endif
 
 #ifdef SQLITE_DEBUG
-#  define REGISTER_TRACE(R,M) if(p->trace)registerTrace(p->trace,R,M)
+#  define REGISTER_TRACE(R,M) if(db->flags&SQLITE_VdbeTrace)registerTrace(R,M)
 #else
 #  define REGISTER_TRACE(R,M)
 #endif
@@ -63376,8 +77562,8 @@ static void registerTrace(FILE *out, int iReg, Mem *p){
 ** This file contains inline asm code for retrieving "high-performance"
 ** counters for x86 class CPUs.
 */
-#ifndef _HWTIME_H_
-#define _HWTIME_H_
+#ifndef SQLITE_HWTIME_H
+#define SQLITE_HWTIME_H
 
 /*
 ** The following routine only works on pentium-class (or newer) processors.
@@ -63445,27 +77631,13 @@ SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
 
 #endif
 
-#endif /* !defined(_HWTIME_H_) */
+#endif /* !defined(SQLITE_HWTIME_H) */
 
 /************** End of hwtime.h **********************************************/
 /************** Continuing where we left off in vdbe.c ***********************/
 
 #endif
 
-/*
-** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
-** sqlite3_interrupt() routine has been called.  If it has been, then
-** processing of the VDBE program is interrupted.
-**
-** This macro added to every instruction that does a jump in order to
-** implement a loop.  This test used to be on every single instruction,
-** but that meant we more testing that we needed.  By only testing the
-** flag on jump instructions, we get a (small) speed improvement.
-*/
-#define CHECK_FOR_INTERRUPT \
-   if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
-
-
 #ifndef NDEBUG
 /*
 ** This function is only called from within an assert() expression. It
@@ -63487,496 +77659,64 @@ static int checkSavepointCount(sqlite3 *db){
 #endif
 
 /*
-** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
-** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
-** in memory obtained from sqlite3DbMalloc).
+** Return the register of pOp->p2 after first preparing it to be
+** overwritten with an integer value.
 */
-static void importVtabErrMsg(Vdbe *p, sqlite3_vtab *pVtab){
-  sqlite3 *db = p->db;
-  sqlite3DbFree(db, p->zErrMsg);
-  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-  sqlite3_free(pVtab->zErrMsg);
-  pVtab->zErrMsg = 0;
+static SQLITE_NOINLINE Mem *out2PrereleaseWithClear(Mem *pOut){
+  sqlite3VdbeMemSetNull(pOut);
+  pOut->flags = MEM_Int;
+  return pOut;
+}
+static Mem *out2Prerelease(Vdbe *p, VdbeOp *pOp){
+  Mem *pOut;
+  assert( pOp->p2>0 );
+  assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+  pOut = &p->aMem[pOp->p2];
+  memAboutToChange(p, pOut);
+  if( VdbeMemDynamic(pOut) ){ /*OPTIMIZATION-IF-FALSE*/
+    return out2PrereleaseWithClear(pOut);
+  }else{
+    pOut->flags = MEM_Int;
+    return pOut;
+  }
 }
 
 
 /*
-** Execute as much of a VDBE program as we can then return.
-**
-** sqlite3VdbeMakeReady() must be called before this routine in order to
-** close the program with a final OP_Halt and to set up the callbacks
-** and the error message pointer.
-**
-** Whenever a row or result data is available, this routine will either
-** invoke the result callback (if there is one) or return with
-** SQLITE_ROW.
-**
-** If an attempt is made to open a locked database, then this routine
-** will either invoke the busy callback (if there is one) or it will
-** return SQLITE_BUSY.
-**
-** If an error occurs, an error message is written to memory obtained
-** from sqlite3_malloc() and p->zErrMsg is made to point to that memory.
-** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
-**
-** If the callback ever returns non-zero, then the program exits
-** immediately.  There will be no error message but the p->rc field is
-** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
-**
-** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
-** routine to return SQLITE_ERROR.
-**
-** Other fatal errors return SQLITE_ERROR.
-**
-** After this routine has finished, sqlite3VdbeFinalize() should be
-** used to clean up the mess that was left behind.
+** Execute as much of a VDBE program as we can.
+** This is the core of sqlite3_step().  
 */
 SQLITE_PRIVATE int sqlite3VdbeExec(
   Vdbe *p                    /* The VDBE */
 ){
-  int pc=0;                  /* The program counter */
   Op *aOp = p->aOp;          /* Copy of p->aOp */
-  Op *pOp;                   /* Current operation */
+  Op *pOp = aOp;             /* Current operation */
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+  Op *pOrigOp;               /* Value of pOp at the top of the loop */
+#endif
+#ifdef SQLITE_DEBUG
+  int nExtraDelete = 0;      /* Verifies FORDELETE and AUXDELETE flags */
+#endif
   int rc = SQLITE_OK;        /* Value to return */
   sqlite3 *db = p->db;       /* The database */
   u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */
   u8 encoding = ENC(db);     /* The database encoding */
+  int iCompare = 0;          /* Result of last OP_Compare operation */
+  unsigned nVmStep = 0;      /* Number of virtual machine steps */
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-  int checkProgress;         /* True if progress callbacks are enabled */
-  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
+  unsigned nProgressLimit = 0;/* Invoke xProgress() when nVmStep reaches this */
 #endif
   Mem *aMem = p->aMem;       /* Copy of p->aMem */
   Mem *pIn1 = 0;             /* 1st input operand */
   Mem *pIn2 = 0;             /* 2nd input operand */
   Mem *pIn3 = 0;             /* 3rd input operand */
   Mem *pOut = 0;             /* Output operand */
-  int iCompare = 0;          /* Result of last OP_Compare operation */
   int *aPermute = 0;         /* Permutation of columns for OP_Compare */
   i64 lastRowid = db->lastRowid;  /* Saved value of the last insert ROWID */
 #ifdef VDBE_PROFILE
   u64 start;                 /* CPU clock count at start of opcode */
-  int origPc;                /* Program counter at start of opcode */
 #endif
-  /********************************************************************
-  ** Automatically generated code
-  **
-  ** The following union is automatically generated by the
-  ** vdbe-compress.tcl script.  The purpose of this union is to
-  ** reduce the amount of stack space required by this function.
-  ** See comments in the vdbe-compress.tcl script for details.
-  */
-  union vdbeExecUnion {
-    struct OP_Yield_stack_vars {
-      int pcDest;
-    } aa;
-    struct OP_Variable_stack_vars {
-      Mem *pVar;       /* Value being transferred */
-    } ab;
-    struct OP_Move_stack_vars {
-      char *zMalloc;   /* Holding variable for allocated memory */
-      int n;           /* Number of registers left to copy */
-      int p1;          /* Register to copy from */
-      int p2;          /* Register to copy to */
-    } ac;
-    struct OP_ResultRow_stack_vars {
-      Mem *pMem;
-      int i;
-    } ad;
-    struct OP_Concat_stack_vars {
-      i64 nByte;
-    } ae;
-    struct OP_Remainder_stack_vars {
-      int flags;      /* Combined MEM_* flags from both inputs */
-      i64 iA;         /* Integer value of left operand */
-      i64 iB;         /* Integer value of right operand */
-      double rA;      /* Real value of left operand */
-      double rB;      /* Real value of right operand */
-    } af;
-    struct OP_Function_stack_vars {
-      int i;
-      Mem *pArg;
-      sqlite3_context ctx;
-      sqlite3_value **apVal;
-      int n;
-    } ag;
-    struct OP_ShiftRight_stack_vars {
-      i64 iA;
-      u64 uA;
-      i64 iB;
-      u8 op;
-    } ah;
-    struct OP_Ge_stack_vars {
-      int res;            /* Result of the comparison of pIn1 against pIn3 */
-      char affinity;      /* Affinity to use for comparison */
-      u16 flags1;         /* Copy of initial value of pIn1->flags */
-      u16 flags3;         /* Copy of initial value of pIn3->flags */
-    } ai;
-    struct OP_Compare_stack_vars {
-      int n;
-      int i;
-      int p1;
-      int p2;
-      const KeyInfo *pKeyInfo;
-      int idx;
-      CollSeq *pColl;    /* Collating sequence to use on this term */
-      int bRev;          /* True for DESCENDING sort order */
-    } aj;
-    struct OP_Or_stack_vars {
-      int v1;    /* Left operand:  0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
-      int v2;    /* Right operand: 0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
-    } ak;
-    struct OP_IfNot_stack_vars {
-      int c;
-    } al;
-    struct OP_Column_stack_vars {
-      u32 payloadSize;   /* Number of bytes in the record */
-      i64 payloadSize64; /* Number of bytes in the record */
-      int p1;            /* P1 value of the opcode */
-      int p2;            /* column number to retrieve */
-      VdbeCursor *pC;    /* The VDBE cursor */
-      char *zRec;        /* Pointer to complete record-data */
-      BtCursor *pCrsr;   /* The BTree cursor */
-      u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
-      u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
-      int nField;        /* number of fields in the record */
-      int len;           /* The length of the serialized data for the column */
-      int i;             /* Loop counter */
-      char *zData;       /* Part of the record being decoded */
-      Mem *pDest;        /* Where to write the extracted value */
-      Mem sMem;          /* For storing the record being decoded */
-      u8 *zIdx;          /* Index into header */
-      u8 *zEndHdr;       /* Pointer to first byte after the header */
-      u32 offset;        /* Offset into the data */
-      u32 szField;       /* Number of bytes in the content of a field */
-      int szHdr;         /* Size of the header size field at start of record */
-      int avail;         /* Number of bytes of available data */
-      u32 t;             /* A type code from the record header */
-      Mem *pReg;         /* PseudoTable input register */
-    } am;
-    struct OP_Affinity_stack_vars {
-      const char *zAffinity;   /* The affinity to be applied */
-      char cAff;               /* A single character of affinity */
-    } an;
-    struct OP_MakeRecord_stack_vars {
-      u8 *zNewRecord;        /* A buffer to hold the data for the new record */
-      Mem *pRec;             /* The new record */
-      u64 nData;             /* Number of bytes of data space */
-      int nHdr;              /* Number of bytes of header space */
-      i64 nByte;             /* Data space required for this record */
-      int nZero;             /* Number of zero bytes at the end of the record */
-      int nVarint;           /* Number of bytes in a varint */
-      u32 serial_type;       /* Type field */
-      Mem *pData0;           /* First field to be combined into the record */
-      Mem *pLast;            /* Last field of the record */
-      int nField;            /* Number of fields in the record */
-      char *zAffinity;       /* The affinity string for the record */
-      int file_format;       /* File format to use for encoding */
-      int i;                 /* Space used in zNewRecord[] */
-      int len;               /* Length of a field */
-    } ao;
-    struct OP_Count_stack_vars {
-      i64 nEntry;
-      BtCursor *pCrsr;
-    } ap;
-    struct OP_Savepoint_stack_vars {
-      int p1;                         /* Value of P1 operand */
-      char *zName;                    /* Name of savepoint */
-      int nName;
-      Savepoint *pNew;
-      Savepoint *pSavepoint;
-      Savepoint *pTmp;
-      int iSavepoint;
-      int ii;
-    } aq;
-    struct OP_AutoCommit_stack_vars {
-      int desiredAutoCommit;
-      int iRollback;
-      int turnOnAC;
-    } ar;
-    struct OP_Transaction_stack_vars {
-      Btree *pBt;
-    } as;
-    struct OP_ReadCookie_stack_vars {
-      int iMeta;
-      int iDb;
-      int iCookie;
-    } at;
-    struct OP_SetCookie_stack_vars {
-      Db *pDb;
-    } au;
-    struct OP_VerifyCookie_stack_vars {
-      int iMeta;
-      int iGen;
-      Btree *pBt;
-    } av;
-    struct OP_OpenWrite_stack_vars {
-      int nField;
-      KeyInfo *pKeyInfo;
-      int p2;
-      int iDb;
-      int wrFlag;
-      Btree *pX;
-      VdbeCursor *pCur;
-      Db *pDb;
-    } aw;
-    struct OP_OpenEphemeral_stack_vars {
-      VdbeCursor *pCx;
-    } ax;
-    struct OP_SorterOpen_stack_vars {
-      VdbeCursor *pCx;
-    } ay;
-    struct OP_OpenPseudo_stack_vars {
-      VdbeCursor *pCx;
-    } az;
-    struct OP_SeekGt_stack_vars {
-      int res;
-      int oc;
-      VdbeCursor *pC;
-      UnpackedRecord r;
-      int nField;
-      i64 iKey;      /* The rowid we are to seek to */
-    } ba;
-    struct OP_Seek_stack_vars {
-      VdbeCursor *pC;
-    } bb;
-    struct OP_Found_stack_vars {
-      int alreadyExists;
-      VdbeCursor *pC;
-      int res;
-      char *pFree;
-      UnpackedRecord *pIdxKey;
-      UnpackedRecord r;
-      char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
-    } bc;
-    struct OP_IsUnique_stack_vars {
-      u16 ii;
-      VdbeCursor *pCx;
-      BtCursor *pCrsr;
-      u16 nField;
-      Mem *aMx;
-      UnpackedRecord r;                  /* B-Tree index search key */
-      i64 R;                             /* Rowid stored in register P3 */
-    } bd;
-    struct OP_NotExists_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      int res;
-      u64 iKey;
-    } be;
-    struct OP_NewRowid_stack_vars {
-      i64 v;                 /* The new rowid */
-      VdbeCursor *pC;        /* Cursor of table to get the new rowid */
-      int res;               /* Result of an sqlite3BtreeLast() */
-      int cnt;               /* Counter to limit the number of searches */
-      Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
-      VdbeFrame *pFrame;     /* Root frame of VDBE */
-    } bf;
-    struct OP_InsertInt_stack_vars {
-      Mem *pData;       /* MEM cell holding data for the record to be inserted */
-      Mem *pKey;        /* MEM cell holding key  for the record */
-      i64 iKey;         /* The integer ROWID or key for the record to be inserted */
-      VdbeCursor *pC;   /* Cursor to table into which insert is written */
-      int nZero;        /* Number of zero-bytes to append */
-      int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
-      const char *zDb;  /* database name - used by the update hook */
-      const char *zTbl; /* Table name - used by the opdate hook */
-      int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
-    } bg;
-    struct OP_Delete_stack_vars {
-      i64 iKey;
-      VdbeCursor *pC;
-    } bh;
-    struct OP_SorterCompare_stack_vars {
-      VdbeCursor *pC;
-      int res;
-    } bi;
-    struct OP_SorterData_stack_vars {
-      VdbeCursor *pC;
-    } bj;
-    struct OP_RowData_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      u32 n;
-      i64 n64;
-    } bk;
-    struct OP_Rowid_stack_vars {
-      VdbeCursor *pC;
-      i64 v;
-      sqlite3_vtab *pVtab;
-      const sqlite3_module *pModule;
-    } bl;
-    struct OP_NullRow_stack_vars {
-      VdbeCursor *pC;
-    } bm;
-    struct OP_Last_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      int res;
-    } bn;
-    struct OP_Rewind_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      int res;
-    } bo;
-    struct OP_Next_stack_vars {
-      VdbeCursor *pC;
-      int res;
-    } bp;
-    struct OP_IdxInsert_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      int nKey;
-      const char *zKey;
-    } bq;
-    struct OP_IdxDelete_stack_vars {
-      VdbeCursor *pC;
-      BtCursor *pCrsr;
-      int res;
-      UnpackedRecord r;
-    } br;
-    struct OP_IdxRowid_stack_vars {
-      BtCursor *pCrsr;
-      VdbeCursor *pC;
-      i64 rowid;
-    } bs;
-    struct OP_IdxGE_stack_vars {
-      VdbeCursor *pC;
-      int res;
-      UnpackedRecord r;
-    } bt;
-    struct OP_Destroy_stack_vars {
-      int iMoved;
-      int iCnt;
-      Vdbe *pVdbe;
-      int iDb;
-    } bu;
-    struct OP_Clear_stack_vars {
-      int nChange;
-    } bv;
-    struct OP_CreateTable_stack_vars {
-      int pgno;
-      int flags;
-      Db *pDb;
-    } bw;
-    struct OP_ParseSchema_stack_vars {
-      int iDb;
-      const char *zMaster;
-      char *zSql;
-      InitData initData;
-    } bx;
-    struct OP_IntegrityCk_stack_vars {
-      int nRoot;      /* Number of tables to check.  (Number of root pages.) */
-      int *aRoot;     /* Array of rootpage numbers for tables to be checked */
-      int j;          /* Loop counter */
-      int nErr;       /* Number of errors reported */
-      char *z;        /* Text of the error report */
-      Mem *pnErr;     /* Register keeping track of errors remaining */
-    } by;
-    struct OP_RowSetRead_stack_vars {
-      i64 val;
-    } bz;
-    struct OP_RowSetTest_stack_vars {
-      int iSet;
-      int exists;
-    } ca;
-    struct OP_Program_stack_vars {
-      int nMem;               /* Number of memory registers for sub-program */
-      int nByte;              /* Bytes of runtime space required for sub-program */
-      Mem *pRt;               /* Register to allocate runtime space */
-      Mem *pMem;              /* Used to iterate through memory cells */
-      Mem *pEnd;              /* Last memory cell in new array */
-      VdbeFrame *pFrame;      /* New vdbe frame to execute in */
-      SubProgram *pProgram;   /* Sub-program to execute */
-      void *t;                /* Token identifying trigger */
-    } cb;
-    struct OP_Param_stack_vars {
-      VdbeFrame *pFrame;
-      Mem *pIn;
-    } cc;
-    struct OP_MemMax_stack_vars {
-      Mem *pIn1;
-      VdbeFrame *pFrame;
-    } cd;
-    struct OP_AggStep_stack_vars {
-      int n;
-      int i;
-      Mem *pMem;
-      Mem *pRec;
-      sqlite3_context ctx;
-      sqlite3_value **apVal;
-    } ce;
-    struct OP_AggFinal_stack_vars {
-      Mem *pMem;
-    } cf;
-    struct OP_Checkpoint_stack_vars {
-      int i;                          /* Loop counter */
-      int aRes[3];                    /* Results */
-      Mem *pMem;                      /* Write results here */
-    } cg;
-    struct OP_JournalMode_stack_vars {
-      Btree *pBt;                     /* Btree to change journal mode of */
-      Pager *pPager;                  /* Pager associated with pBt */
-      int eNew;                       /* New journal mode */
-      int eOld;                       /* The old journal mode */
-      const char *zFilename;          /* Name of database file for pPager */
-    } ch;
-    struct OP_IncrVacuum_stack_vars {
-      Btree *pBt;
-    } ci;
-    struct OP_VBegin_stack_vars {
-      VTable *pVTab;
-    } cj;
-    struct OP_VOpen_stack_vars {
-      VdbeCursor *pCur;
-      sqlite3_vtab_cursor *pVtabCursor;
-      sqlite3_vtab *pVtab;
-      sqlite3_module *pModule;
-    } ck;
-    struct OP_VFilter_stack_vars {
-      int nArg;
-      int iQuery;
-      const sqlite3_module *pModule;
-      Mem *pQuery;
-      Mem *pArgc;
-      sqlite3_vtab_cursor *pVtabCursor;
-      sqlite3_vtab *pVtab;
-      VdbeCursor *pCur;
-      int res;
-      int i;
-      Mem **apArg;
-    } cl;
-    struct OP_VColumn_stack_vars {
-      sqlite3_vtab *pVtab;
-      const sqlite3_module *pModule;
-      Mem *pDest;
-      sqlite3_context sContext;
-    } cm;
-    struct OP_VNext_stack_vars {
-      sqlite3_vtab *pVtab;
-      const sqlite3_module *pModule;
-      int res;
-      VdbeCursor *pCur;
-    } cn;
-    struct OP_VRename_stack_vars {
-      sqlite3_vtab *pVtab;
-      Mem *pName;
-    } co;
-    struct OP_VUpdate_stack_vars {
-      sqlite3_vtab *pVtab;
-      sqlite3_module *pModule;
-      int nArg;
-      int i;
-      sqlite_int64 rowid;
-      Mem **apArg;
-      Mem *pX;
-    } cp;
-    struct OP_Trace_stack_vars {
-      char *zTrace;
-      char *z;
-    } cq;
-  } u;
-  /* End automatically generated code
-  ********************************************************************/
+  /*** INSERT STACK UNION HERE ***/
 
   assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
   sqlite3VdbeEnter(p);
@@ -63985,46 +77725,68 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
     ** sqlite3_column_text16() failed.  */
     goto no_mem;
   }
-  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+  assert( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_BUSY );
+  assert( p->bIsReader || p->readOnly!=0 );
   p->rc = SQLITE_OK;
+  p->iCurrentTime = 0;
   assert( p->explain==0 );
   p->pResultSet = 0;
   db->busyHandler.nBusy = 0;
-  CHECK_FOR_INTERRUPT;
+  if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
   sqlite3VdbeIOTraceSql(p);
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-  checkProgress = db->xProgress!=0;
+  if( db->xProgress ){
+    u32 iPrior = p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
+    assert( 0 < db->nProgressOps );
+    nProgressLimit = db->nProgressOps - (iPrior % db->nProgressOps);
+  }
 #endif
 #ifdef SQLITE_DEBUG
   sqlite3BeginBenignMalloc();
-  if( p->pc==0  && (p->db->flags & SQLITE_VdbeListing)!=0 ){
+  if( p->pc==0
+   && (p->db->flags & (SQLITE_VdbeListing|SQLITE_VdbeEQP|SQLITE_VdbeTrace))!=0
+  ){
     int i;
-    printf("VDBE Program Listing:\n");
+    int once = 1;
     sqlite3VdbePrintSql(p);
-    for(i=0; i<p->nOp; i++){
-      sqlite3VdbePrintOp(stdout, i, &aOp[i]);
+    if( p->db->flags & SQLITE_VdbeListing ){
+      printf("VDBE Program Listing:\n");
+      for(i=0; i<p->nOp; i++){
+        sqlite3VdbePrintOp(stdout, i, &aOp[i]);
+      }
     }
+    if( p->db->flags & SQLITE_VdbeEQP ){
+      for(i=0; i<p->nOp; i++){
+        if( aOp[i].opcode==OP_Explain ){
+          if( once ) printf("VDBE Query Plan:\n");
+          printf("%s\n", aOp[i].p4.z);
+          once = 0;
+        }
+      }
+    }
+    if( p->db->flags & SQLITE_VdbeTrace )  printf("VDBE Trace:\n");
   }
   sqlite3EndBenignMalloc();
 #endif
-  for(pc=p->pc; rc==SQLITE_OK; pc++){
-    assert( pc>=0 && pc<p->nOp );
-    if( db->mallocFailed ) goto no_mem;
+  for(pOp=&aOp[p->pc]; 1; pOp++){
+    /* Errors are detected by individual opcodes, with an immediate
+    ** jumps to abort_due_to_error. */
+    assert( rc==SQLITE_OK );
+
+    assert( pOp>=aOp && pOp<&aOp[p->nOp]);
 #ifdef VDBE_PROFILE
-    origPc = pc;
     start = sqlite3Hwtime();
 #endif
-    pOp = &aOp[pc];
+    nVmStep++;
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+    if( p->anExec ) p->anExec[(int)(pOp-aOp)]++;
+#endif
 
     /* Only allow tracing if SQLITE_DEBUG is defined.
     */
 #ifdef SQLITE_DEBUG
-    if( p->trace ){
-      if( pc==0 ){
-        printf("VDBE Execution Trace:\n");
-        sqlite3VdbePrintSql(p);
-      }
-      sqlite3VdbePrintOp(p->trace, pc, pOp);
+    if( db->flags & SQLITE_VdbeTrace ){
+      sqlite3VdbePrintOp(stdout, (int)(pOp - aOp), pOp);
     }
 #endif
       
@@ -64041,73 +77803,46 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
     }
 #endif
 
-#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-    /* Call the progress callback if it is configured and the required number
-    ** of VDBE ops have been executed (either since this invocation of
-    ** sqlite3VdbeExec() or since last time the progress callback was called).
-    ** If the progress callback returns non-zero, exit the virtual machine with
-    ** a return code SQLITE_ABORT.
-    */
-    if( checkProgress ){
-      if( db->nProgressOps==nProgressOps ){
-        int prc;
-        prc = db->xProgress(db->pProgressArg);
-        if( prc!=0 ){
-          rc = SQLITE_INTERRUPT;
-          goto vdbe_error_halt;
-        }
-        nProgressOps = 0;
-      }
-      nProgressOps++;
-    }
-#endif
-
-    /* On any opcode with the "out2-prerelase" tag, free any
-    ** external allocations out of mem[p2] and set mem[p2] to be
-    ** an undefined integer.  Opcodes will either fill in the integer
-    ** value or convert mem[p2] to a different type.
-    */
-    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
-    if( pOp->opflags & OPFLG_OUT2_PRERELEASE ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=p->nMem );
-      pOut = &aMem[pOp->p2];
-      memAboutToChange(p, pOut);
-      MemReleaseExt(pOut);
-      pOut->flags = MEM_Int;
-    }
-
     /* Sanity checking on other operands */
 #ifdef SQLITE_DEBUG
-    if( (pOp->opflags & OPFLG_IN1)!=0 ){
-      assert( pOp->p1>0 );
-      assert( pOp->p1<=p->nMem );
-      assert( memIsValid(&aMem[pOp->p1]) );
-      REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
-    }
-    if( (pOp->opflags & OPFLG_IN2)!=0 ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=p->nMem );
-      assert( memIsValid(&aMem[pOp->p2]) );
-      REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
-    }
-    if( (pOp->opflags & OPFLG_IN3)!=0 ){
-      assert( pOp->p3>0 );
-      assert( pOp->p3<=p->nMem );
-      assert( memIsValid(&aMem[pOp->p3]) );
-      REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
-    }
-    if( (pOp->opflags & OPFLG_OUT2)!=0 ){
-      assert( pOp->p2>0 );
-      assert( pOp->p2<=p->nMem );
-      memAboutToChange(p, &aMem[pOp->p2]);
-    }
-    if( (pOp->opflags & OPFLG_OUT3)!=0 ){
-      assert( pOp->p3>0 );
-      assert( pOp->p3<=p->nMem );
-      memAboutToChange(p, &aMem[pOp->p3]);
+    {
+      u8 opProperty = sqlite3OpcodeProperty[pOp->opcode];
+      if( (opProperty & OPFLG_IN1)!=0 ){
+        assert( pOp->p1>0 );
+        assert( pOp->p1<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p1]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p1]) );
+        REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
+      }
+      if( (opProperty & OPFLG_IN2)!=0 ){
+        assert( pOp->p2>0 );
+        assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p2]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p2]) );
+        REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
+      }
+      if( (opProperty & OPFLG_IN3)!=0 ){
+        assert( pOp->p3>0 );
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+        assert( memIsValid(&aMem[pOp->p3]) );
+        assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p3]) );
+        REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
+      }
+      if( (opProperty & OPFLG_OUT2)!=0 ){
+        assert( pOp->p2>0 );
+        assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
+        memAboutToChange(p, &aMem[pOp->p2]);
+      }
+      if( (opProperty & OPFLG_OUT3)!=0 ){
+        assert( pOp->p3>0 );
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+        memAboutToChange(p, &aMem[pOp->p3]);
+      }
     }
 #endif
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+    pOrigOp = pOp;
+#endif
   
     switch( pOp->opcode ){
 
@@ -64131,7 +77866,7 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
 **
 ** Other keywords in the comment that follows each case are used to
 ** construct the OPFLG_INITIALIZER value that initializes opcodeProperty[].
-** Keywords include: in1, in2, in3, out2_prerelease, out2, out3.  See
+** Keywords include: in1, in2, in3, out2, out3.  See
 ** the mkopcodeh.awk script for additional information.
 **
 ** Documentation about VDBE opcodes is generated by scanning this file
@@ -64152,10 +77887,45 @@ SQLITE_PRIVATE int sqlite3VdbeExec(
 ** The next instruction executed will be 
 ** the one at index P2 from the beginning of
 ** the program.
+**
+** The P1 parameter is not actually used by this opcode.  However, it
+** is sometimes set to 1 instead of 0 as a hint to the command-line shell
+** that this Goto is the bottom of a loop and that the lines from P2 down
+** to the current line should be indented for EXPLAIN output.
 */
 case OP_Goto: {             /* jump */
-  CHECK_FOR_INTERRUPT;
-  pc = pOp->p2 - 1;
+jump_to_p2_and_check_for_interrupt:
+  pOp = &aOp[pOp->p2 - 1];
+
+  /* Opcodes that are used as the bottom of a loop (OP_Next, OP_Prev,
+  ** OP_VNext, OP_RowSetNext, or OP_SorterNext) all jump here upon
+  ** completion.  Check to see if sqlite3_interrupt() has been called
+  ** or if the progress callback needs to be invoked. 
+  **
+  ** This code uses unstructured "goto" statements and does not look clean.
+  ** But that is not due to sloppy coding habits. The code is written this
+  ** way for performance, to avoid having to run the interrupt and progress
+  ** checks on every opcode.  This helps sqlite3_step() to run about 1.5%
+  ** faster according to "valgrind --tool=cachegrind" */
+check_for_interrupt:
+  if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+  /* Call the progress callback if it is configured and the required number
+  ** of VDBE ops have been executed (either since this invocation of
+  ** sqlite3VdbeExec() or since last time the progress callback was called).
+  ** If the progress callback returns non-zero, exit the virtual machine with
+  ** a return code SQLITE_ABORT.
+  */
+  if( db->xProgress!=0 && nVmStep>=nProgressLimit ){
+    assert( db->nProgressOps!=0 );
+    nProgressLimit = nVmStep + db->nProgressOps - (nVmStep%db->nProgressOps);
+    if( db->xProgress(db->pProgressArg) ){
+      rc = SQLITE_INTERRUPT;
+      goto abort_due_to_error;
+    }
+  }
+#endif
+  
   break;
 }
 
@@ -64164,51 +77934,111 @@ case OP_Goto: {             /* jump */
 ** Write the current address onto register P1
 ** and then jump to address P2.
 */
-case OP_Gosub: {            /* jump, in1 */
+case OP_Gosub: {            /* jump */
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
   pIn1 = &aMem[pOp->p1];
-  assert( (pIn1->flags & MEM_Dyn)==0 );
+  assert( VdbeMemDynamic(pIn1)==0 );
   memAboutToChange(p, pIn1);
   pIn1->flags = MEM_Int;
-  pIn1->u.i = pc;
+  pIn1->u.i = (int)(pOp-aOp);
   REGISTER_TRACE(pOp->p1, pIn1);
-  pc = pOp->p2 - 1;
+
+  /* Most jump operations do a goto to this spot in order to update
+  ** the pOp pointer. */
+jump_to_p2:
+  pOp = &aOp[pOp->p2 - 1];
   break;
 }
 
 /* Opcode:  Return P1 * * * *
 **
-** Jump to the next instruction after the address in register P1.
+** Jump to the next instruction after the address in register P1.  After
+** the jump, register P1 becomes undefined.
 */
 case OP_Return: {           /* in1 */
   pIn1 = &aMem[pOp->p1];
-  assert( pIn1->flags & MEM_Int );
-  pc = (int)pIn1->u.i;
+  assert( pIn1->flags==MEM_Int );
+  pOp = &aOp[pIn1->u.i];
+  pIn1->flags = MEM_Undefined;
+  break;
+}
+
+/* Opcode: InitCoroutine P1 P2 P3 * *
+**
+** Set up register P1 so that it will Yield to the coroutine
+** located at address P3.
+**
+** If P2!=0 then the coroutine implementation immediately follows
+** this opcode.  So jump over the coroutine implementation to
+** address P2.
+**
+** See also: EndCoroutine
+*/
+case OP_InitCoroutine: {     /* jump */
+  assert( pOp->p1>0 &&  pOp->p1<=(p->nMem+1 - p->nCursor) );
+  assert( pOp->p2>=0 && pOp->p2<p->nOp );
+  assert( pOp->p3>=0 && pOp->p3<p->nOp );
+  pOut = &aMem[pOp->p1];
+  assert( !VdbeMemDynamic(pOut) );
+  pOut->u.i = pOp->p3 - 1;
+  pOut->flags = MEM_Int;
+  if( pOp->p2 ) goto jump_to_p2;
   break;
 }
 
-/* Opcode:  Yield P1 * * * *
+/* Opcode:  EndCoroutine P1 * * * *
 **
-** Swap the program counter with the value in register P1.
+** The instruction at the address in register P1 is a Yield.
+** Jump to the P2 parameter of that Yield.
+** After the jump, register P1 becomes undefined.
+**
+** See also: InitCoroutine
 */
-case OP_Yield: {            /* in1 */
-#if 0  /* local variables moved into u.aa */
+case OP_EndCoroutine: {           /* in1 */
+  VdbeOp *pCaller;
+  pIn1 = &aMem[pOp->p1];
+  assert( pIn1->flags==MEM_Int );
+  assert( pIn1->u.i>=0 && pIn1->u.i<p->nOp );
+  pCaller = &aOp[pIn1->u.i];
+  assert( pCaller->opcode==OP_Yield );
+  assert( pCaller->p2>=0 && pCaller->p2<p->nOp );
+  pOp = &aOp[pCaller->p2 - 1];
+  pIn1->flags = MEM_Undefined;
+  break;
+}
+
+/* Opcode:  Yield P1 P2 * * *
+**
+** Swap the program counter with the value in register P1.  This
+** has the effect of yielding to a coroutine.
+**
+** If the coroutine that is launched by this instruction ends with
+** Yield or Return then continue to the next instruction.  But if
+** the coroutine launched by this instruction ends with
+** EndCoroutine, then jump to P2 rather than continuing with the
+** next instruction.
+**
+** See also: InitCoroutine
+*/
+case OP_Yield: {            /* in1, jump */
   int pcDest;
-#endif /* local variables moved into u.aa */
   pIn1 = &aMem[pOp->p1];
-  assert( (pIn1->flags & MEM_Dyn)==0 );
+  assert( VdbeMemDynamic(pIn1)==0 );
   pIn1->flags = MEM_Int;
-  u.aa.pcDest = (int)pIn1->u.i;
-  pIn1->u.i = pc;
+  pcDest = (int)pIn1->u.i;
+  pIn1->u.i = (int)(pOp - aOp);
   REGISTER_TRACE(pOp->p1, pIn1);
-  pc = u.aa.pcDest;
+  pOp = &aOp[pcDest];
   break;
 }
 
-/* Opcode:  HaltIfNull  P1 P2 P3 P4 *
+/* Opcode:  HaltIfNull  P1 P2 P3 P4 P5
+** Synopsis:  if r[P3]=null halt
 **
 ** Check the value in register P3.  If it is NULL then Halt using
 ** parameter P1, P2, and P4 as if this were a Halt instruction.  If the
 ** value in register P3 is not NULL, then this routine is a no-op.
+** The P5 parameter should be 1.
 */
 case OP_HaltIfNull: {      /* in3 */
   pIn3 = &aMem[pOp->p3];
@@ -64216,7 +78046,7 @@ case OP_HaltIfNull: {      /* in3 */
   /* Fall through into OP_Halt */
 }
 
-/* Opcode:  Halt P1 P2 * P4 *
+/* Opcode:  Halt P1 P2 * P4 P5
 **
 ** Exit immediately.  All open cursors, etc are closed
 ** automatically.
@@ -64231,71 +78061,99 @@ case OP_HaltIfNull: {      /* in3 */
 **
 ** If P4 is not null then it is an error message string.
 **
+** P5 is a value between 0 and 4, inclusive, that modifies the P4 string.
+**
+**    0:  (no change)
+**    1:  NOT NULL contraint failed: P4
+**    2:  UNIQUE constraint failed: P4
+**    3:  CHECK constraint failed: P4
+**    4:  FOREIGN KEY constraint failed: P4
+**
+** If P5 is not zero and P4 is NULL, then everything after the ":" is
+** omitted.
+**
 ** There is an implied "Halt 0 0 0" instruction inserted at the very end of
 ** every program.  So a jump past the last instruction of the program
 ** is the same as executing Halt.
 */
 case OP_Halt: {
+  VdbeFrame *pFrame;
+  int pcx;
+
+  pcx = (int)(pOp - aOp);
   if( pOp->p1==SQLITE_OK && p->pFrame ){
     /* Halt the sub-program. Return control to the parent frame. */
-    VdbeFrame *pFrame = p->pFrame;
+    pFrame = p->pFrame;
     p->pFrame = pFrame->pParent;
     p->nFrame--;
     sqlite3VdbeSetChanges(db, p->nChange);
-    pc = sqlite3VdbeFrameRestore(pFrame);
+    pcx = sqlite3VdbeFrameRestore(pFrame);
     lastRowid = db->lastRowid;
     if( pOp->p2==OE_Ignore ){
-      /* Instruction pc is the OP_Program that invoked the sub-program 
+      /* Instruction pcx is the OP_Program that invoked the sub-program 
       ** currently being halted. If the p2 instruction of this OP_Halt
       ** instruction is set to OE_Ignore, then the sub-program is throwing
       ** an IGNORE exception. In this case jump to the address specified
       ** as the p2 of the calling OP_Program.  */
-      pc = p->aOp[pc].p2-1;
+      pcx = p->aOp[pcx].p2-1;
     }
     aOp = p->aOp;
     aMem = p->aMem;
+    pOp = &aOp[pcx];
     break;
   }
-
   p->rc = pOp->p1;
   p->errorAction = (u8)pOp->p2;
-  p->pc = pc;
-  if( pOp->p4.z ){
-    assert( p->rc!=SQLITE_OK );
-    sqlite3SetString(&p->zErrMsg, db, "%s", pOp->p4.z);
-    testcase( sqlite3GlobalConfig.xLog!=0 );
-    sqlite3_log(pOp->p1, "abort at %d in [%s]: %s", pc, p->zSql, pOp->p4.z);
-  }else if( p->rc ){
-    testcase( sqlite3GlobalConfig.xLog!=0 );
-    sqlite3_log(pOp->p1, "constraint failed at %d in [%s]", pc, p->zSql);
+  p->pc = pcx;
+  assert( pOp->p5>=0 && pOp->p5<=4 );
+  if( p->rc ){
+    if( pOp->p5 ){
+      static const char * const azType[] = { "NOT NULL", "UNIQUE", "CHECK",
+                                             "FOREIGN KEY" };
+      testcase( pOp->p5==1 );
+      testcase( pOp->p5==2 );
+      testcase( pOp->p5==3 );
+      testcase( pOp->p5==4 );
+      sqlite3VdbeError(p, "%s constraint failed", azType[pOp->p5-1]);
+      if( pOp->p4.z ){
+        p->zErrMsg = sqlite3MPrintf(db, "%z: %s", p->zErrMsg, pOp->p4.z);
+      }
+    }else{
+      sqlite3VdbeError(p, "%s", pOp->p4.z);
+    }
+    sqlite3_log(pOp->p1, "abort at %d in [%s]: %s", pcx, p->zSql, p->zErrMsg);
   }
   rc = sqlite3VdbeHalt(p);
   assert( rc==SQLITE_BUSY || rc==SQLITE_OK || rc==SQLITE_ERROR );
   if( rc==SQLITE_BUSY ){
-    p->rc = rc = SQLITE_BUSY;
+    p->rc = SQLITE_BUSY;
   }else{
-    assert( rc==SQLITE_OK || p->rc==SQLITE_CONSTRAINT );
-    assert( rc==SQLITE_OK || db->nDeferredCons>0 );
+    assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );
+    assert( rc==SQLITE_OK || db->nDeferredCons>0 || db->nDeferredImmCons>0 );
     rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
   }
   goto vdbe_return;
 }
 
 /* Opcode: Integer P1 P2 * * *
+** Synopsis: r[P2]=P1
 **
 ** The 32-bit integer value P1 is written into register P2.
 */
-case OP_Integer: {         /* out2-prerelease */
+case OP_Integer: {         /* out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = pOp->p1;
   break;
 }
 
 /* Opcode: Int64 * P2 * P4 *
+** Synopsis: r[P2]=P4
 **
 ** P4 is a pointer to a 64-bit integer value.
 ** Write that value into register P2.
 */
-case OP_Int64: {           /* out2-prerelease */
+case OP_Int64: {           /* out2 */
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p4.pI64!=0 );
   pOut->u.i = *pOp->p4.pI64;
   break;
@@ -64303,38 +78161,43 @@ case OP_Int64: {           /* out2-prerelease */
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /* Opcode: Real * P2 * P4 *
+** Synopsis: r[P2]=P4
 **
 ** P4 is a pointer to a 64-bit floating point value.
 ** Write that value into register P2.
 */
-case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
+case OP_Real: {            /* same as TK_FLOAT, out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Real;
   assert( !sqlite3IsNaN(*pOp->p4.pReal) );
-  pOut->r = *pOp->p4.pReal;
+  pOut->u.r = *pOp->p4.pReal;
   break;
 }
 #endif
 
 /* Opcode: String8 * P2 * P4 *
+** Synopsis: r[P2]='P4'
 **
 ** P4 points to a nul terminated UTF-8 string. This opcode is transformed 
-** into an OP_String before it is executed for the first time.
+** into a String opcode before it is executed for the first time.  During
+** this transformation, the length of string P4 is computed and stored
+** as the P1 parameter.
 */
-case OP_String8: {         /* same as TK_STRING, out2-prerelease */
+case OP_String8: {         /* same as TK_STRING, out2 */
   assert( pOp->p4.z!=0 );
+  pOut = out2Prerelease(p, pOp);
   pOp->opcode = OP_String;
   pOp->p1 = sqlite3Strlen30(pOp->p4.z);
 
 #ifndef SQLITE_OMIT_UTF16
   if( encoding!=SQLITE_UTF8 ){
     rc = sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
-    if( rc==SQLITE_TOOBIG ) goto too_big;
+    assert( rc==SQLITE_OK || rc==SQLITE_TOOBIG );
     if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
-    assert( pOut->zMalloc==pOut->z );
-    assert( pOut->flags & MEM_Dyn );
-    pOut->zMalloc = 0;
+    assert( pOut->szMalloc>0 && pOut->zMalloc==pOut->z );
+    assert( VdbeMemDynamic(pOut)==0 );
+    pOut->szMalloc = 0;
     pOut->flags |= MEM_Static;
-    pOut->flags &= ~MEM_Dyn;
     if( pOp->p4type==P4_DYNAMIC ){
       sqlite3DbFree(db, pOp->p4.z);
     }
@@ -64342,44 +78205,99 @@ case OP_String8: {         /* same as TK_STRING, out2-prerelease */
     pOp->p4.z = pOut->z;
     pOp->p1 = pOut->n;
   }
+  testcase( rc==SQLITE_TOOBIG );
 #endif
   if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
+  assert( rc==SQLITE_OK );
   /* Fall through to the next case, OP_String */
 }
   
-/* Opcode: String P1 P2 * P4 *
+/* Opcode: String P1 P2 P3 P4 P5
+** Synopsis: r[P2]='P4' (len=P1)
 **
 ** The string value P4 of length P1 (bytes) is stored in register P2.
+**
+** If P3 is not zero and the content of register P3 is equal to P5, then
+** the datatype of the register P2 is converted to BLOB.  The content is
+** the same sequence of bytes, it is merely interpreted as a BLOB instead
+** of a string, as if it had been CAST.  In other words:
+**
+** if( P3!=0 and reg[P3]==P5 ) reg[P2] := CAST(reg[P2] as BLOB)
 */
-case OP_String: {          /* out2-prerelease */
+case OP_String: {          /* out2 */
   assert( pOp->p4.z!=0 );
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Str|MEM_Static|MEM_Term;
   pOut->z = pOp->p4.z;
   pOut->n = pOp->p1;
   pOut->enc = encoding;
   UPDATE_MAX_BLOBSIZE(pOut);
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  if( pOp->p3>0 ){
+    assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+    pIn3 = &aMem[pOp->p3];
+    assert( pIn3->flags & MEM_Int );
+    if( pIn3->u.i==pOp->p5 ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
+  }
+#endif
   break;
 }
 
-/* Opcode: Null * P2 * * *
+/* Opcode: Null P1 P2 P3 * *
+** Synopsis:  r[P2..P3]=NULL
 **
-** Write a NULL into register P2.
+** Write a NULL into registers P2.  If P3 greater than P2, then also write
+** NULL into register P3 and every register in between P2 and P3.  If P3
+** is less than P2 (typically P3 is zero) then only register P2 is
+** set to NULL.
+**
+** If the P1 value is non-zero, then also set the MEM_Cleared flag so that
+** NULL values will not compare equal even if SQLITE_NULLEQ is set on
+** OP_Ne or OP_Eq.
 */
-case OP_Null: {           /* out2-prerelease */
-  pOut->flags = MEM_Null;
+case OP_Null: {           /* out2 */
+  int cnt;
+  u16 nullFlag;
+  pOut = out2Prerelease(p, pOp);
+  cnt = pOp->p3-pOp->p2;
+  assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+  pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
+  while( cnt>0 ){
+    pOut++;
+    memAboutToChange(p, pOut);
+    sqlite3VdbeMemSetNull(pOut);
+    pOut->flags = nullFlag;
+    cnt--;
+  }
   break;
 }
 
+/* Opcode: SoftNull P1 * * * *
+** Synopsis:  r[P1]=NULL
+**
+** Set register P1 to have the value NULL as seen by the OP_MakeRecord
+** instruction, but do not free any string or blob memory associated with
+** the register, so that if the value was a string or blob that was
+** previously copied using OP_SCopy, the copies will continue to be valid.
+*/
+case OP_SoftNull: {
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
+  pOut = &aMem[pOp->p1];
+  pOut->flags = (pOut->flags|MEM_Null)&~MEM_Undefined;
+  break;
+}
 
-/* Opcode: Blob P1 P2 * P4
+/* Opcode: Blob P1 P2 * P4 *
+** Synopsis: r[P2]=P4 (len=P1)
 **
 ** P4 points to a blob of data P1 bytes long.  Store this
 ** blob in register P2.
 */
-case OP_Blob: {                /* out2-prerelease */
+case OP_Blob: {                /* out2 */
   assert( pOp->p1 <= SQLITE_MAX_LENGTH );
+  pOut = out2Prerelease(p, pOp);
   sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
   pOut->enc = encoding;
   UPDATE_MAX_BLOBSIZE(pOut);
@@ -64387,90 +78305,100 @@ case OP_Blob: {                /* out2-prerelease */
 }
 
 /* Opcode: Variable P1 P2 * P4 *
+** Synopsis: r[P2]=parameter(P1,P4)
 **
 ** Transfer the values of bound parameter P1 into register P2
 **
-** If the parameter is named, then its name appears in P4 and P3==1.
+** If the parameter is named, then its name appears in P4.
 ** The P4 value is used by sqlite3_bind_parameter_name().
 */
-case OP_Variable: {            /* out2-prerelease */
-#if 0  /* local variables moved into u.ab */
+case OP_Variable: {            /* out2 */
   Mem *pVar;       /* Value being transferred */
-#endif /* local variables moved into u.ab */
 
   assert( pOp->p1>0 && pOp->p1<=p->nVar );
   assert( pOp->p4.z==0 || pOp->p4.z==p->azVar[pOp->p1-1] );
-  u.ab.pVar = &p->aVar[pOp->p1 - 1];
-  if( sqlite3VdbeMemTooBig(u.ab.pVar) ){
+  pVar = &p->aVar[pOp->p1 - 1];
+  if( sqlite3VdbeMemTooBig(pVar) ){
     goto too_big;
   }
-  sqlite3VdbeMemShallowCopy(pOut, u.ab.pVar, MEM_Static);
+  pOut = out2Prerelease(p, pOp);
+  sqlite3VdbeMemShallowCopy(pOut, pVar, MEM_Static);
   UPDATE_MAX_BLOBSIZE(pOut);
   break;
 }
 
 /* Opcode: Move P1 P2 P3 * *
+** Synopsis:  r[P2@P3]=r[P1@P3]
 **
-** Move the values in register P1..P1+P3-1 over into
-** registers P2..P2+P3-1.  Registers P1..P1+P1-1 are
+** Move the P3 values in register P1..P1+P3-1 over into
+** registers P2..P2+P3-1.  Registers P1..P1+P3-1 are
 ** left holding a NULL.  It is an error for register ranges
-** P1..P1+P3-1 and P2..P2+P3-1 to overlap.
+** P1..P1+P3-1 and P2..P2+P3-1 to overlap.  It is an error
+** for P3 to be less than 1.
 */
 case OP_Move: {
-#if 0  /* local variables moved into u.ac */
-  char *zMalloc;   /* Holding variable for allocated memory */
   int n;           /* Number of registers left to copy */
   int p1;          /* Register to copy from */
   int p2;          /* Register to copy to */
-#endif /* local variables moved into u.ac */
-
-  u.ac.n = pOp->p3;
-  u.ac.p1 = pOp->p1;
-  u.ac.p2 = pOp->p2;
-  assert( u.ac.n>0 && u.ac.p1>0 && u.ac.p2>0 );
-  assert( u.ac.p1+u.ac.n<=u.ac.p2 || u.ac.p2+u.ac.n<=u.ac.p1 );
-
-  pIn1 = &aMem[u.ac.p1];
-  pOut = &aMem[u.ac.p2];
-  while( u.ac.n-- ){
-    assert( pOut<=&aMem[p->nMem] );
-    assert( pIn1<=&aMem[p->nMem] );
+
+  n = pOp->p3;
+  p1 = pOp->p1;
+  p2 = pOp->p2;
+  assert( n>0 && p1>0 && p2>0 );
+  assert( p1+n<=p2 || p2+n<=p1 );
+
+  pIn1 = &aMem[p1];
+  pOut = &aMem[p2];
+  do{
+    assert( pOut<=&aMem[(p->nMem+1 - p->nCursor)] );
+    assert( pIn1<=&aMem[(p->nMem+1 - p->nCursor)] );
     assert( memIsValid(pIn1) );
     memAboutToChange(p, pOut);
-    u.ac.zMalloc = pOut->zMalloc;
-    pOut->zMalloc = 0;
     sqlite3VdbeMemMove(pOut, pIn1);
 #ifdef SQLITE_DEBUG
-    if( pOut->pScopyFrom>=&aMem[u.ac.p1] && pOut->pScopyFrom<&aMem[u.ac.p1+pOp->p3] ){
-      pOut->pScopyFrom += u.ac.p1 - pOp->p2;
+    if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<pOut ){
+      pOut->pScopyFrom += pOp->p2 - p1;
     }
 #endif
-    pIn1->zMalloc = u.ac.zMalloc;
-    REGISTER_TRACE(u.ac.p2++, pOut);
+    Deephemeralize(pOut);
+    REGISTER_TRACE(p2++, pOut);
     pIn1++;
     pOut++;
-  }
+  }while( --n );
   break;
 }
 
-/* Opcode: Copy P1 P2 * * *
+/* Opcode: Copy P1 P2 P3 * *
+** Synopsis: r[P2@P3+1]=r[P1@P3+1]
 **
-** Make a copy of register P1 into register P2.
+** Make a copy of registers P1..P1+P3 into registers P2..P2+P3.
 **
 ** This instruction makes a deep copy of the value.  A duplicate
 ** is made of any string or blob constant.  See also OP_SCopy.
 */
-case OP_Copy: {             /* in1, out2 */
+case OP_Copy: {
+  int n;
+
+  n = pOp->p3;
   pIn1 = &aMem[pOp->p1];
   pOut = &aMem[pOp->p2];
   assert( pOut!=pIn1 );
-  sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
-  Deephemeralize(pOut);
-  REGISTER_TRACE(pOp->p2, pOut);
+  while( 1 ){
+    sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
+    Deephemeralize(pOut);
+#ifdef SQLITE_DEBUG
+    pOut->pScopyFrom = 0;
+#endif
+    REGISTER_TRACE(pOp->p2+pOp->p3-n, pOut);
+    if( (n--)==0 ) break;
+    pOut++;
+    pIn1++;
+  }
   break;
 }
 
 /* Opcode: SCopy P1 P2 * * *
+** Synopsis: r[P2]=r[P1]
 **
 ** Make a shallow copy of register P1 into register P2.
 **
@@ -64482,7 +78410,7 @@ case OP_Copy: {             /* in1, out2 */
 ** during the lifetime of the copy.  Use OP_Copy to make a complete
 ** copy.
 */
-case OP_SCopy: {            /* in1, out2 */
+case OP_SCopy: {            /* out2 */
   pIn1 = &aMem[pOp->p1];
   pOut = &aMem[pOp->p2];
   assert( pOut!=pIn1 );
@@ -64490,26 +78418,52 @@ case OP_SCopy: {            /* in1, out2 */
 #ifdef SQLITE_DEBUG
   if( pOut->pScopyFrom==0 ) pOut->pScopyFrom = pIn1;
 #endif
-  REGISTER_TRACE(pOp->p2, pOut);
+  break;
+}
+
+/* Opcode: IntCopy P1 P2 * * *
+** Synopsis: r[P2]=r[P1]
+**
+** Transfer the integer value held in register P1 into register P2.
+**
+** This is an optimized version of SCopy that works only for integer
+** values.
+*/
+case OP_IntCopy: {            /* out2 */
+  pIn1 = &aMem[pOp->p1];
+  assert( (pIn1->flags & MEM_Int)!=0 );
+  pOut = &aMem[pOp->p2];
+  sqlite3VdbeMemSetInt64(pOut, pIn1->u.i);
   break;
 }
 
 /* Opcode: ResultRow P1 P2 * * *
+** Synopsis:  output=r[P1@P2]
 **
 ** The registers P1 through P1+P2-1 contain a single row of
 ** results. This opcode causes the sqlite3_step() call to terminate
 ** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
-** structure to provide access to the top P1 values as the result
-** row.
+** structure to provide access to the r(P1)..r(P1+P2-1) values as
+** the result row.
 */
 case OP_ResultRow: {
-#if 0  /* local variables moved into u.ad */
   Mem *pMem;
   int i;
-#endif /* local variables moved into u.ad */
   assert( p->nResColumn==pOp->p2 );
   assert( pOp->p1>0 );
-  assert( pOp->p1+pOp->p2<=p->nMem+1 );
+  assert( pOp->p1+pOp->p2<=(p->nMem+1 - p->nCursor)+1 );
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+  /* Run the progress counter just before returning.
+  */
+  if( db->xProgress!=0
+   && nVmStep>=nProgressLimit
+   && db->xProgress(db->pProgressArg)!=0
+  ){
+    rc = SQLITE_INTERRUPT;
+    goto abort_due_to_error;
+  }
+#endif
 
   /* If this statement has violated immediate foreign key constraints, do
   ** not return the number of rows modified. And do not RELEASE the statement
@@ -64517,11 +78471,11 @@ case OP_ResultRow: {
   if( SQLITE_OK!=(rc = sqlite3VdbeCheckFk(p, 0)) ){
     assert( db->flags&SQLITE_CountRows );
     assert( p->usesStmtJournal );
-    break;
+    goto abort_due_to_error;
   }
 
-  /* If the SQLITE_CountRows flag is set in sqlite3.flags mask, then
-  ** DML statements invoke this opcode to return the number of rows
+  /* If the SQLITE_CountRows flag is set in sqlite3.flags mask, then 
+  ** DML statements invoke this opcode to return the number of rows 
   ** modified to the user. This is the only way that a VM that
   ** opens a statement transaction may invoke this opcode.
   **
@@ -64537,37 +78491,39 @@ case OP_ResultRow: {
   */
   assert( p->iStatement==0 || db->flags&SQLITE_CountRows );
   rc = sqlite3VdbeCloseStatement(p, SAVEPOINT_RELEASE);
-  if( NEVER(rc!=SQLITE_OK) ){
-    break;
-  }
+  assert( rc==SQLITE_OK );
 
   /* Invalidate all ephemeral cursor row caches */
   p->cacheCtr = (p->cacheCtr + 2)|1;
 
   /* Make sure the results of the current row are \000 terminated
   ** and have an assigned type.  The results are de-ephemeralized as
-  ** as side effect.
-  */
-  u.ad.pMem = p->pResultSet = &aMem[pOp->p1];
-  for(u.ad.i=0; u.ad.i<pOp->p2; u.ad.i++){
-    assert( memIsValid(&u.ad.pMem[u.ad.i]) );
-    Deephemeralize(&u.ad.pMem[u.ad.i]);
-    assert( (u.ad.pMem[u.ad.i].flags & MEM_Ephem)==0
-            || (u.ad.pMem[u.ad.i].flags & (MEM_Str|MEM_Blob))==0 );
-    sqlite3VdbeMemNulTerminate(&u.ad.pMem[u.ad.i]);
-    sqlite3VdbeMemStoreType(&u.ad.pMem[u.ad.i]);
-    REGISTER_TRACE(pOp->p1+u.ad.i, &u.ad.pMem[u.ad.i]);
+  ** a side effect.
+  */
+  pMem = p->pResultSet = &aMem[pOp->p1];
+  for(i=0; i<pOp->p2; i++){
+    assert( memIsValid(&pMem[i]) );
+    Deephemeralize(&pMem[i]);
+    assert( (pMem[i].flags & MEM_Ephem)==0
+            || (pMem[i].flags & (MEM_Str|MEM_Blob))==0 );
+    sqlite3VdbeMemNulTerminate(&pMem[i]);
+    REGISTER_TRACE(pOp->p1+i, &pMem[i]);
   }
   if( db->mallocFailed ) goto no_mem;
 
+  if( db->mTrace & SQLITE_TRACE_ROW ){
+    db->xTrace(SQLITE_TRACE_ROW, db->pTraceArg, p, 0);
+  }
+
   /* Return SQLITE_ROW
   */
-  p->pc = pc + 1;
+  p->pc = (int)(pOp - aOp) + 1;
   rc = SQLITE_ROW;
   goto vdbe_return;
 }
 
 /* Opcode: Concat P1 P2 P3 * *
+** Synopsis: r[P3]=r[P2]+r[P1]
 **
 ** Add the text in register P1 onto the end of the text in
 ** register P2 and store the result in register P3.
@@ -64580,9 +78536,7 @@ case OP_ResultRow: {
 ** to avoid a memcpy().
 */
 case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
-#if 0  /* local variables moved into u.ae */
   i64 nByte;
-#endif /* local variables moved into u.ae */
 
   pIn1 = &aMem[pOp->p1];
   pIn2 = &aMem[pOp->p2];
@@ -64595,34 +78549,36 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
   if( ExpandBlob(pIn1) || ExpandBlob(pIn2) ) goto no_mem;
   Stringify(pIn1, encoding);
   Stringify(pIn2, encoding);
-  u.ae.nByte = pIn1->n + pIn2->n;
-  if( u.ae.nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+  nByte = pIn1->n + pIn2->n;
+  if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
-  MemSetTypeFlag(pOut, MEM_Str);
-  if( sqlite3VdbeMemGrow(pOut, (int)u.ae.nByte+2, pOut==pIn2) ){
+  if( sqlite3VdbeMemGrow(pOut, (int)nByte+2, pOut==pIn2) ){
     goto no_mem;
   }
+  MemSetTypeFlag(pOut, MEM_Str);
   if( pOut!=pIn2 ){
     memcpy(pOut->z, pIn2->z, pIn2->n);
   }
   memcpy(&pOut->z[pIn2->n], pIn1->z, pIn1->n);
-  pOut->z[u.ae.nByte] = 0;
-  pOut->z[u.ae.nByte+1] = 0;
+  pOut->z[nByte]=0;
+  pOut->z[nByte+1] = 0;
   pOut->flags |= MEM_Term;
-  pOut->n = (int)u.ae.nByte;
+  pOut->n = (int)nByte;
   pOut->enc = encoding;
   UPDATE_MAX_BLOBSIZE(pOut);
   break;
 }
 
 /* Opcode: Add P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P1]+r[P2]
 **
 ** Add the value in register P1 to the value in register P2
 ** and store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Multiply P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P1]*r[P2]
 **
 **
 ** Multiply the value in register P1 by the value in register P2
@@ -64630,12 +78586,14 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Subtract P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P2]-r[P1]
 **
 ** Subtract the value in register P1 from the value in register P2
 ** and store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: Divide P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P2]/r[P1]
 **
 ** Divide the value in register P1 by the value in register P2
 ** and store the result in register P3 (P3=P2/P1). If the value in 
@@ -64643,10 +78601,11 @@ case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
 ** NULL, the result is NULL.
 */
 /* Opcode: Remainder P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P2]%r[P1]
 **
-** Compute the remainder after integer division of the value in
-** register P1 by the value in register P2 and store the result in P3. 
-** If the value in register P2 is zero the result is NULL.
+** Compute the remainder after integer register P2 is divided by 
+** register P1 and store the result in register P3. 
+** If the value in register P1 is zero the result is NULL.
 ** If either operand is NULL, the result is NULL.
 */
 case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */
@@ -64654,76 +78613,79 @@ case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */
 case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */
 case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */
 case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
-#if 0  /* local variables moved into u.af */
-  int flags;      /* Combined MEM_* flags from both inputs */
+  char bIntint;   /* Started out as two integer operands */
+  u16 flags;      /* Combined MEM_* flags from both inputs */
+  u16 type1;      /* Numeric type of left operand */
+  u16 type2;      /* Numeric type of right operand */
   i64 iA;         /* Integer value of left operand */
   i64 iB;         /* Integer value of right operand */
   double rA;      /* Real value of left operand */
   double rB;      /* Real value of right operand */
-#endif /* local variables moved into u.af */
 
   pIn1 = &aMem[pOp->p1];
-  applyNumericAffinity(pIn1);
+  type1 = numericType(pIn1);
   pIn2 = &aMem[pOp->p2];
-  applyNumericAffinity(pIn2);
+  type2 = numericType(pIn2);
   pOut = &aMem[pOp->p3];
-  u.af.flags = pIn1->flags | pIn2->flags;
-  if( (u.af.flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
-  if( (pIn1->flags & pIn2->flags & MEM_Int)==MEM_Int ){
-    u.af.iA = pIn1->u.i;
-    u.af.iB = pIn2->u.i;
+  flags = pIn1->flags | pIn2->flags;
+  if( (flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
+  if( (type1 & type2 & MEM_Int)!=0 ){
+    iA = pIn1->u.i;
+    iB = pIn2->u.i;
+    bIntint = 1;
     switch( pOp->opcode ){
-      case OP_Add:       if( sqlite3AddInt64(&u.af.iB,u.af.iA) ) goto fp_math;  break;
-      case OP_Subtract:  if( sqlite3SubInt64(&u.af.iB,u.af.iA) ) goto fp_math;  break;
-      case OP_Multiply:  if( sqlite3MulInt64(&u.af.iB,u.af.iA) ) goto fp_math;  break;
+      case OP_Add:       if( sqlite3AddInt64(&iB,iA) ) goto fp_math;  break;
+      case OP_Subtract:  if( sqlite3SubInt64(&iB,iA) ) goto fp_math;  break;
+      case OP_Multiply:  if( sqlite3MulInt64(&iB,iA) ) goto fp_math;  break;
       case OP_Divide: {
-        if( u.af.iA==0 ) goto arithmetic_result_is_null;
-        if( u.af.iA==-1 && u.af.iB==SMALLEST_INT64 ) goto fp_math;
-        u.af.iB /= u.af.iA;
+        if( iA==0 ) goto arithmetic_result_is_null;
+        if( iA==-1 && iB==SMALLEST_INT64 ) goto fp_math;
+        iB /= iA;
         break;
       }
       default: {
-        if( u.af.iA==0 ) goto arithmetic_result_is_null;
-        if( u.af.iA==-1 ) u.af.iA = 1;
-        u.af.iB %= u.af.iA;
+        if( iA==0 ) goto arithmetic_result_is_null;
+        if( iA==-1 ) iA = 1;
+        iB %= iA;
         break;
       }
     }
-    pOut->u.i = u.af.iB;
+    pOut->u.i = iB;
     MemSetTypeFlag(pOut, MEM_Int);
   }else{
+    bIntint = 0;
 fp_math:
-    u.af.rA = sqlite3VdbeRealValue(pIn1);
-    u.af.rB = sqlite3VdbeRealValue(pIn2);
+    rA = sqlite3VdbeRealValue(pIn1);
+    rB = sqlite3VdbeRealValue(pIn2);
     switch( pOp->opcode ){
-      case OP_Add:         u.af.rB += u.af.rA;       break;
-      case OP_Subtract:    u.af.rB -= u.af.rA;       break;
-      case OP_Multiply:    u.af.rB *= u.af.rA;       break;
+      case OP_Add:         rB += rA;       break;
+      case OP_Subtract:    rB -= rA;       break;
+      case OP_Multiply:    rB *= rA;       break;
       case OP_Divide: {
         /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
-        if( u.af.rA==(double)0 ) goto arithmetic_result_is_null;
-        u.af.rB /= u.af.rA;
+        if( rA==(double)0 ) goto arithmetic_result_is_null;
+        rB /= rA;
         break;
       }
       default: {
-        u.af.iA = (i64)u.af.rA;
-        u.af.iB = (i64)u.af.rB;
-        if( u.af.iA==0 ) goto arithmetic_result_is_null;
-        if( u.af.iA==-1 ) u.af.iA = 1;
-        u.af.rB = (double)(u.af.iB % u.af.iA);
+        iA = (i64)rA;
+        iB = (i64)rB;
+        if( iA==0 ) goto arithmetic_result_is_null;
+        if( iA==-1 ) iA = 1;
+        rB = (double)(iB % iA);
         break;
       }
     }
 #ifdef SQLITE_OMIT_FLOATING_POINT
-    pOut->u.i = u.af.rB;
+    pOut->u.i = rB;
     MemSetTypeFlag(pOut, MEM_Int);
 #else
-    if( sqlite3IsNaN(u.af.rB) ){
+    if( sqlite3IsNaN(rB) ){
       goto arithmetic_result_is_null;
     }
-    pOut->r = u.af.rB;
+    pOut->u.r = rB;
     MemSetTypeFlag(pOut, MEM_Real);
-    if( (u.af.flags & MEM_Real)==0 ){
+    if( ((type1|type2)&MEM_Real)==0 && !bIntint ){
       sqlite3VdbeIntegerAffinity(pOut);
     }
 #endif
@@ -64735,25 +78697,33 @@ arithmetic_result_is_null:
   break;
 }
 
-/* Opcode: CollSeq * * P4
+/* Opcode: CollSeq P1 * * P4
 **
 ** P4 is a pointer to a CollSeq struct. If the next call to a user function
 ** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
 ** be returned. This is used by the built-in min(), max() and nullif()
 ** functions.
 **
+** If P1 is not zero, then it is a register that a subsequent min() or
+** max() aggregate will set to 1 if the current row is not the minimum or
+** maximum.  The P1 register is initialized to 0 by this instruction.
+**
 ** The interface used by the implementation of the aforementioned functions
 ** to retrieve the collation sequence set by this opcode is not available
-** publicly, only to user functions defined in func.c.
+** publicly.  Only built-in functions have access to this feature.
 */
 case OP_CollSeq: {
   assert( pOp->p4type==P4_COLLSEQ );
+  if( pOp->p1 ){
+    sqlite3VdbeMemSetInt64(&aMem[pOp->p1], 0);
+  }
   break;
 }
 
-/* Opcode: Function P1 P2 P3 P4 P5
+/* Opcode: Function0 P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
 **
-** Invoke a user function (P4 is a pointer to a Function structure that
+** Invoke a user function (P4 is a pointer to a FuncDef object that
 ** defines the function) with P5 arguments taken from register P2 and
 ** successors.  The result of the function is stored in register P3.
 ** Register P3 must not be one of the function inputs.
@@ -64765,125 +78735,120 @@ case OP_CollSeq: {
 ** sqlite3_set_auxdata() API may be safely retained until the next
 ** invocation of this opcode.
 **
-** See also: AggStep and AggFinal
+** See also: Function, AggStep, AggFinal
+*/
+/* Opcode: Function P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
+**
+** Invoke a user function (P4 is a pointer to an sqlite3_context object that
+** contains a pointer to the function to be run) with P5 arguments taken
+** from register P2 and successors.  The result of the function is stored
+** in register P3.  Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** SQL functions are initially coded as OP_Function0 with P4 pointing
+** to a FuncDef object.  But on first evaluation, the P4 operand is
+** automatically converted into an sqlite3_context object and the operation
+** changed to this OP_Function opcode.  In this way, the initialization of
+** the sqlite3_context object occurs only once, rather than once for each
+** evaluation of the function.
+**
+** See also: Function0, AggStep, AggFinal
 */
+case OP_Function0: {
+  int n;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCDEF );
+  n = pOp->p5;
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
+  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
+  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
+  if( pCtx==0 ) goto no_mem;
+  pCtx->pOut = 0;
+  pCtx->pFunc = pOp->p4.pFunc;
+  pCtx->iOp = (int)(pOp - aOp);
+  pCtx->pVdbe = p;
+  pCtx->argc = n;
+  pOp->p4type = P4_FUNCCTX;
+  pOp->p4.pCtx = pCtx;
+  pOp->opcode = OP_Function;
+  /* Fall through into OP_Function */
+}
 case OP_Function: {
-#if 0  /* local variables moved into u.ag */
   int i;
-  Mem *pArg;
-  sqlite3_context ctx;
-  sqlite3_value **apVal;
-  int n;
-#endif /* local variables moved into u.ag */
+  sqlite3_context *pCtx;
 
-  u.ag.n = pOp->p5;
-  u.ag.apVal = p->apArg;
-  assert( u.ag.apVal || u.ag.n==0 );
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  pOut = &aMem[pOp->p3];
-  memAboutToChange(p, pOut);
+  assert( pOp->p4type==P4_FUNCCTX );
+  pCtx = pOp->p4.pCtx;
 
-  assert( u.ag.n==0 || (pOp->p2>0 && pOp->p2+u.ag.n<=p->nMem+1) );
-  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+u.ag.n );
-  u.ag.pArg = &aMem[pOp->p2];
-  for(u.ag.i=0; u.ag.i<u.ag.n; u.ag.i++, u.ag.pArg++){
-    assert( memIsValid(u.ag.pArg) );
-    u.ag.apVal[u.ag.i] = u.ag.pArg;
-    Deephemeralize(u.ag.pArg);
-    sqlite3VdbeMemStoreType(u.ag.pArg);
-    REGISTER_TRACE(pOp->p2+u.ag.i, u.ag.pArg);
-  }
-
-  assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
-  if( pOp->p4type==P4_FUNCDEF ){
-    u.ag.ctx.pFunc = pOp->p4.pFunc;
-    u.ag.ctx.pVdbeFunc = 0;
-  }else{
-    u.ag.ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.pVdbeFunc;
-    u.ag.ctx.pFunc = u.ag.ctx.pVdbeFunc->pFunc;
+  /* If this function is inside of a trigger, the register array in aMem[]
+  ** might change from one evaluation to the next.  The next block of code
+  ** checks to see if the register array has changed, and if so it
+  ** reinitializes the relavant parts of the sqlite3_context object */
+  pOut = &aMem[pOp->p3];
+  if( pCtx->pOut != pOut ){
+    pCtx->pOut = pOut;
+    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
   }
 
-  u.ag.ctx.s.flags = MEM_Null;
-  u.ag.ctx.s.db = db;
-  u.ag.ctx.s.xDel = 0;
-  u.ag.ctx.s.zMalloc = 0;
-
-  /* The output cell may already have a buffer allocated. Move
-  ** the pointer to u.ag.ctx.s so in case the user-function can use
-  ** the already allocated buffer instead of allocating a new one.
-  */
-  sqlite3VdbeMemMove(&u.ag.ctx.s, pOut);
-  MemSetTypeFlag(&u.ag.ctx.s, MEM_Null);
-
-  u.ag.ctx.isError = 0;
-  if( u.ag.ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
-    assert( pOp>aOp );
-    assert( pOp[-1].p4type==P4_COLLSEQ );
-    assert( pOp[-1].opcode==OP_CollSeq );
-    u.ag.ctx.pColl = pOp[-1].p4.pColl;
+  memAboutToChange(p, pCtx->pOut);
+#ifdef SQLITE_DEBUG
+  for(i=0; i<pCtx->argc; i++){
+    assert( memIsValid(pCtx->argv[i]) );
+    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
   }
+#endif
+  MemSetTypeFlag(pCtx->pOut, MEM_Null);
+  pCtx->fErrorOrAux = 0;
   db->lastRowid = lastRowid;
-  (*u.ag.ctx.pFunc->xFunc)(&u.ag.ctx, u.ag.n, u.ag.apVal); /* IMP: R-24505-23230 */
-  lastRowid = db->lastRowid;
-
-  /* If any auxiliary data functions have been called by this user function,
-  ** immediately call the destructor for any non-static values.
-  */
-  if( u.ag.ctx.pVdbeFunc ){
-    sqlite3VdbeDeleteAuxData(u.ag.ctx.pVdbeFunc, pOp->p1);
-    pOp->p4.pVdbeFunc = u.ag.ctx.pVdbeFunc;
-    pOp->p4type = P4_VDBEFUNC;
-  }
-
-  if( db->mallocFailed ){
-    /* Even though a malloc() has failed, the implementation of the
-    ** user function may have called an sqlite3_result_XXX() function
-    ** to return a value. The following call releases any resources
-    ** associated with such a value.
-    */
-    sqlite3VdbeMemRelease(&u.ag.ctx.s);
-    goto no_mem;
-  }
+  (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */
+  lastRowid = db->lastRowid;  /* Remember rowid changes made by xSFunc */
 
   /* If the function returned an error, throw an exception */
-  if( u.ag.ctx.isError ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&u.ag.ctx.s));
-    rc = u.ag.ctx.isError;
+  if( pCtx->fErrorOrAux ){
+    if( pCtx->isError ){
+      sqlite3VdbeError(p, "%s", sqlite3_value_text(pCtx->pOut));
+      rc = pCtx->isError;
+    }
+    sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);
+    if( rc ) goto abort_due_to_error;
   }
 
   /* Copy the result of the function into register P3 */
-  sqlite3VdbeChangeEncoding(&u.ag.ctx.s, encoding);
-  sqlite3VdbeMemMove(pOut, &u.ag.ctx.s);
-  if( sqlite3VdbeMemTooBig(pOut) ){
-    goto too_big;
+  if( pOut->flags & (MEM_Str|MEM_Blob) ){
+    sqlite3VdbeChangeEncoding(pCtx->pOut, encoding);
+    if( sqlite3VdbeMemTooBig(pCtx->pOut) ) goto too_big;
   }
 
-#if 0
-  /* The app-defined function has done something that as caused this
-  ** statement to expire.  (Perhaps the function called sqlite3_exec()
-  ** with a CREATE TABLE statement.)
-  */
-  if( p->expired ) rc = SQLITE_ABORT;
-#endif
-
-  REGISTER_TRACE(pOp->p3, pOut);
-  UPDATE_MAX_BLOBSIZE(pOut);
+  REGISTER_TRACE(pOp->p3, pCtx->pOut);
+  UPDATE_MAX_BLOBSIZE(pCtx->pOut);
   break;
 }
 
 /* Opcode: BitAnd P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P1]&r[P2]
 **
 ** Take the bit-wise AND of the values in register P1 and P2 and
 ** store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: BitOr P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P1]|r[P2]
 **
 ** Take the bit-wise OR of the values in register P1 and P2 and
 ** store the result in register P3.
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: ShiftLeft P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P2]<<r[P1]
 **
 ** Shift the integer value in register P2 to the left by the
 ** number of bits specified by the integer in register P1.
@@ -64891,6 +78856,7 @@ case OP_Function: {
 ** If either input is NULL, the result is NULL.
 */
 /* Opcode: ShiftRight P1 P2 P3 * *
+** Synopsis:  r[P3]=r[P2]>>r[P1]
 **
 ** Shift the integer value in register P2 to the right by the
 ** number of bits specified by the integer in register P1.
@@ -64901,12 +78867,10 @@ case OP_BitAnd:                 /* same as TK_BITAND, in1, in2, out3 */
 case OP_BitOr:                  /* same as TK_BITOR, in1, in2, out3 */
 case OP_ShiftLeft:              /* same as TK_LSHIFT, in1, in2, out3 */
 case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */
-#if 0  /* local variables moved into u.ah */
   i64 iA;
   u64 uA;
   i64 iB;
   u8 op;
-#endif /* local variables moved into u.ah */
 
   pIn1 = &aMem[pOp->p1];
   pIn2 = &aMem[pOp->p2];
@@ -64915,43 +78879,44 @@ case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */
     sqlite3VdbeMemSetNull(pOut);
     break;
   }
-  u.ah.iA = sqlite3VdbeIntValue(pIn2);
-  u.ah.iB = sqlite3VdbeIntValue(pIn1);
-  u.ah.op = pOp->opcode;
-  if( u.ah.op==OP_BitAnd ){
-    u.ah.iA &= u.ah.iB;
-  }else if( u.ah.op==OP_BitOr ){
-    u.ah.iA |= u.ah.iB;
-  }else if( u.ah.iB!=0 ){
-    assert( u.ah.op==OP_ShiftRight || u.ah.op==OP_ShiftLeft );
+  iA = sqlite3VdbeIntValue(pIn2);
+  iB = sqlite3VdbeIntValue(pIn1);
+  op = pOp->opcode;
+  if( op==OP_BitAnd ){
+    iA &= iB;
+  }else if( op==OP_BitOr ){
+    iA |= iB;
+  }else if( iB!=0 ){
+    assert( op==OP_ShiftRight || op==OP_ShiftLeft );
 
     /* If shifting by a negative amount, shift in the other direction */
-    if( u.ah.iB<0 ){
+    if( iB<0 ){
       assert( OP_ShiftRight==OP_ShiftLeft+1 );
-      u.ah.op = 2*OP_ShiftLeft + 1 - u.ah.op;
-      u.ah.iB = u.ah.iB>(-64) ? -u.ah.iB : 64;
+      op = 2*OP_ShiftLeft + 1 - op;
+      iB = iB>(-64) ? -iB : 64;
     }
 
-    if( u.ah.iB>=64 ){
-      u.ah.iA = (u.ah.iA>=0 || u.ah.op==OP_ShiftLeft) ? 0 : -1;
+    if( iB>=64 ){
+      iA = (iA>=0 || op==OP_ShiftLeft) ? 0 : -1;
     }else{
-      memcpy(&u.ah.uA, &u.ah.iA, sizeof(u.ah.uA));
-      if( u.ah.op==OP_ShiftLeft ){
-        u.ah.uA <<= u.ah.iB;
+      memcpy(&uA, &iA, sizeof(uA));
+      if( op==OP_ShiftLeft ){
+        uA <<= iB;
       }else{
-        u.ah.uA >>= u.ah.iB;
+        uA >>= iB;
         /* Sign-extend on a right shift of a negative number */
-        if( u.ah.iA<0 ) u.ah.uA |= ((((u64)0xffffffff)<<32)|0xffffffff) << (64-u.ah.iB);
+        if( iA<0 ) uA |= ((((u64)0xffffffff)<<32)|0xffffffff) << (64-iB);
       }
-      memcpy(&u.ah.iA, &u.ah.uA, sizeof(u.ah.iA));
+      memcpy(&iA, &uA, sizeof(iA));
     }
   }
-  pOut->u.i = u.ah.iA;
+  pOut->u.i = iA;
   MemSetTypeFlag(pOut, MEM_Int);
   break;
 }
 
 /* Opcode: AddImm  P1 P2 * * *
+** Synopsis:  r[P1]=r[P1]+P2
 ** 
 ** Add the constant P2 to the value in register P1.
 ** The result is always an integer.
@@ -64975,17 +78940,19 @@ case OP_AddImm: {            /* in1 */
 */
 case OP_MustBeInt: {            /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
-  applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
   if( (pIn1->flags & MEM_Int)==0 ){
-    if( pOp->p2==0 ){
-      rc = SQLITE_MISMATCH;
-      goto abort_due_to_error;
-    }else{
-      pc = pOp->p2 - 1;
+    applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+    VdbeBranchTaken((pIn1->flags&MEM_Int)==0, 2);
+    if( (pIn1->flags & MEM_Int)==0 ){
+      if( pOp->p2==0 ){
+        rc = SQLITE_MISMATCH;
+        goto abort_due_to_error;
+      }else{
+        goto jump_to_p2;
+      }
     }
-  }else{
-    MemSetTypeFlag(pIn1, MEM_Int);
   }
+  MemSetTypeFlag(pIn1, MEM_Int);
   break;
 }
 
@@ -65009,107 +78976,40 @@ case OP_RealAffinity: {                  /* in1 */
 #endif
 
 #ifndef SQLITE_OMIT_CAST
-/* Opcode: ToText P1 * * * *
+/* Opcode: Cast P1 P2 * * *
+** Synopsis: affinity(r[P1])
 **
-** Force the value in register P1 to be text.
-** If the value is numeric, convert it to a string using the
-** equivalent of printf().  Blob values are unchanged and
-** are afterwards simply interpreted as text.
+** Force the value in register P1 to be the type defined by P2.
+** 
+** <ul>
+** <li value="97"> TEXT
+** <li value="98"> BLOB
+** <li value="99"> NUMERIC
+** <li value="100"> INTEGER
+** <li value="101"> REAL
+** </ul>
 **
 ** A NULL value is not changed by this routine.  It remains NULL.
 */
-case OP_ToText: {                  /* same as TK_TO_TEXT, in1 */
+case OP_Cast: {                  /* in1 */
+  assert( pOp->p2>=SQLITE_AFF_BLOB && pOp->p2<=SQLITE_AFF_REAL );
+  testcase( pOp->p2==SQLITE_AFF_TEXT );
+  testcase( pOp->p2==SQLITE_AFF_BLOB );
+  testcase( pOp->p2==SQLITE_AFF_NUMERIC );
+  testcase( pOp->p2==SQLITE_AFF_INTEGER );
+  testcase( pOp->p2==SQLITE_AFF_REAL );
   pIn1 = &aMem[pOp->p1];
   memAboutToChange(p, pIn1);
-  if( pIn1->flags & MEM_Null ) break;
-  assert( MEM_Str==(MEM_Blob>>3) );
-  pIn1->flags |= (pIn1->flags&MEM_Blob)>>3;
-  applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
   rc = ExpandBlob(pIn1);
-  assert( pIn1->flags & MEM_Str || db->mallocFailed );
-  pIn1->flags &= ~(MEM_Int|MEM_Real|MEM_Blob|MEM_Zero);
+  sqlite3VdbeMemCast(pIn1, pOp->p2, encoding);
   UPDATE_MAX_BLOBSIZE(pIn1);
-  break;
-}
-
-/* Opcode: ToBlob P1 * * * *
-**
-** Force the value in register P1 to be a BLOB.
-** If the value is numeric, convert it to a string first.
-** Strings are simply reinterpreted as blobs with no change
-** to the underlying data.
-**
-** A NULL value is not changed by this routine.  It remains NULL.
-*/
-case OP_ToBlob: {                  /* same as TK_TO_BLOB, in1 */
-  pIn1 = &aMem[pOp->p1];
-  if( pIn1->flags & MEM_Null ) break;
-  if( (pIn1->flags & MEM_Blob)==0 ){
-    applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
-    assert( pIn1->flags & MEM_Str || db->mallocFailed );
-    MemSetTypeFlag(pIn1, MEM_Blob);
-  }else{
-    pIn1->flags &= ~(MEM_TypeMask&~MEM_Blob);
-  }
-  UPDATE_MAX_BLOBSIZE(pIn1);
-  break;
-}
-
-/* Opcode: ToNumeric P1 * * * *
-**
-** Force the value in register P1 to be numeric (either an
-** integer or a floating-point number.)
-** If the value is text or blob, try to convert it to an using the
-** equivalent of atoi() or atof() and store 0 if no such conversion 
-** is possible.
-**
-** A NULL value is not changed by this routine.  It remains NULL.
-*/
-case OP_ToNumeric: {                  /* same as TK_TO_NUMERIC, in1 */
-  pIn1 = &aMem[pOp->p1];
-  sqlite3VdbeMemNumerify(pIn1);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_CAST */
 
-/* Opcode: ToInt P1 * * * *
-**
-** Force the value in register P1 to be an integer.  If
-** The value is currently a real number, drop its fractional part.
-** If the value is text or blob, try to convert it to an integer using the
-** equivalent of atoi() and store 0 if no such conversion is possible.
-**
-** A NULL value is not changed by this routine.  It remains NULL.
-*/
-case OP_ToInt: {                  /* same as TK_TO_INT, in1 */
-  pIn1 = &aMem[pOp->p1];
-  if( (pIn1->flags & MEM_Null)==0 ){
-    sqlite3VdbeMemIntegerify(pIn1);
-  }
-  break;
-}
-
-#if !defined(SQLITE_OMIT_CAST) && !defined(SQLITE_OMIT_FLOATING_POINT)
-/* Opcode: ToReal P1 * * * *
-**
-** Force the value in register P1 to be a floating point number.
-** If The value is currently an integer, convert it.
-** If the value is text or blob, try to convert it to an integer using the
-** equivalent of atoi() and store 0.0 if no such conversion is possible.
-**
-** A NULL value is not changed by this routine.  It remains NULL.
-*/
-case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
-  pIn1 = &aMem[pOp->p1];
-  memAboutToChange(p, pIn1);
-  if( (pIn1->flags & MEM_Null)==0 ){
-    sqlite3VdbeMemRealify(pIn1);
-  }
-  break;
-}
-#endif /* !defined(SQLITE_OMIT_CAST) && !defined(SQLITE_OMIT_FLOATING_POINT) */
-
 /* Opcode: Lt P1 P2 P3 P4 P5
+** Synopsis: if r[P1]<r[P3] goto P2
 **
 ** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then
 ** jump to address P2.  
@@ -65138,8 +79038,13 @@ case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
 **
 ** If the SQLITE_STOREP2 bit of P5 is set, then do not jump.  Instead,
 ** store a boolean result (either 0, or 1, or NULL) in register P2.
+**
+** If the SQLITE_NULLEQ bit is set in P5, then NULL values are considered
+** equal to one another, provided that they do not have their MEM_Cleared
+** bit set.
 */
 /* Opcode: Ne P1 P2 P3 P4 P5
+** Synopsis: if r[P1]!=r[P3] goto P2
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the operands in registers P1 and P3 are not equal.  See the Lt opcode for
@@ -65152,6 +79057,7 @@ case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
 ** the SQLITE_NULLEQ flag were omitted from P5.
 */
 /* Opcode: Eq P1 P2 P3 P4 P5
+** Synopsis: if r[P1]==r[P3] goto P2
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the operands in registers P1 and P3 are equal.
@@ -65164,18 +79070,21 @@ case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
 ** the SQLITE_NULLEQ flag were omitted from P5.
 */
 /* Opcode: Le P1 P2 P3 P4 P5
+** Synopsis: if r[P1]<=r[P3] goto P2
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the content of register P3 is less than or equal to the content of
 ** register P1.  See the Lt opcode for additional information.
 */
 /* Opcode: Gt P1 P2 P3 P4 P5
+** Synopsis: if r[P1]>r[P3] goto P2
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the content of register P3 is greater than the content of
 ** register P1.  See the Lt opcode for additional information.
 */
 /* Opcode: Ge P1 P2 P3 P4 P5
+** Synopsis: if r[P1]>=r[P3] goto P2
 **
 ** This works just like the Lt opcode except that the jump is taken if
 ** the content of register P3 is greater than or equal to the content of
@@ -65187,18 +79096,16 @@ case OP_Lt:               /* same as TK_LT, jump, in1, in3 */
 case OP_Le:               /* same as TK_LE, jump, in1, in3 */
 case OP_Gt:               /* same as TK_GT, jump, in1, in3 */
 case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
-#if 0  /* local variables moved into u.ai */
   int res;            /* Result of the comparison of pIn1 against pIn3 */
   char affinity;      /* Affinity to use for comparison */
   u16 flags1;         /* Copy of initial value of pIn1->flags */
   u16 flags3;         /* Copy of initial value of pIn3->flags */
-#endif /* local variables moved into u.ai */
 
   pIn1 = &aMem[pOp->p1];
   pIn3 = &aMem[pOp->p3];
-  u.ai.flags1 = pIn1->flags;
-  u.ai.flags3 = pIn3->flags;
-  if( (u.ai.flags1 | u.ai.flags3)&MEM_Null ){
+  flags1 = pIn1->flags;
+  flags3 = pIn3->flags;
+  if( (flags1 | flags3)&MEM_Null ){
     /* One or both operands are NULL */
     if( pOp->p5 & SQLITE_NULLEQ ){
       /* If SQLITE_NULLEQ is set (which will only happen if the operator is
@@ -65206,7 +79113,16 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       ** or not both operands are null.
       */
       assert( pOp->opcode==OP_Eq || pOp->opcode==OP_Ne );
-      u.ai.res = (u.ai.flags1 & u.ai.flags3 & MEM_Null)==0;
+      assert( (flags1 & MEM_Cleared)==0 );
+      assert( (pOp->p5 & SQLITE_JUMPIFNULL)==0 );
+      if( (flags1&MEM_Null)!=0
+       && (flags3&MEM_Null)!=0
+       && (flags3&MEM_Cleared)==0
+      ){
+        res = 0;  /* Results are equal */
+      }else{
+        res = 1;  /* Results are not equal */
+      }
     }else{
       /* SQLITE_NULLEQ is clear and at least one operand is NULL,
       ** then the result is always NULL.
@@ -65214,49 +79130,85 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       */
       if( pOp->p5 & SQLITE_STOREP2 ){
         pOut = &aMem[pOp->p2];
+        memAboutToChange(p, pOut);
         MemSetTypeFlag(pOut, MEM_Null);
         REGISTER_TRACE(pOp->p2, pOut);
-      }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
-        pc = pOp->p2-1;
+      }else{
+        VdbeBranchTaken(2,3);
+        if( pOp->p5 & SQLITE_JUMPIFNULL ){
+          goto jump_to_p2;
+        }
       }
       break;
     }
   }else{
     /* Neither operand is NULL.  Do a comparison. */
-    u.ai.affinity = pOp->p5 & SQLITE_AFF_MASK;
-    if( u.ai.affinity ){
-      applyAffinity(pIn1, u.ai.affinity, encoding);
-      applyAffinity(pIn3, u.ai.affinity, encoding);
-      if( db->mallocFailed ) goto no_mem;
+    affinity = pOp->p5 & SQLITE_AFF_MASK;
+    if( affinity>=SQLITE_AFF_NUMERIC ){
+      if( (flags1 | flags3)&MEM_Str ){
+        if( (flags1 & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
+          applyNumericAffinity(pIn1,0);
+          flags3 = pIn3->flags;
+        }
+        if( (flags3 & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
+          applyNumericAffinity(pIn3,0);
+        }
+      }
+    }else if( affinity==SQLITE_AFF_TEXT ){
+      if( (flags1 & MEM_Str)==0 && (flags1 & (MEM_Int|MEM_Real))!=0 ){
+        testcase( pIn1->flags & MEM_Int );
+        testcase( pIn1->flags & MEM_Real );
+        sqlite3VdbeMemStringify(pIn1, encoding, 1);
+        testcase( (flags1&MEM_Dyn) != (pIn1->flags&MEM_Dyn) );
+        flags1 = (pIn1->flags & ~MEM_TypeMask) | (flags1 & MEM_TypeMask);
+        flags3 = pIn3->flags;
+      }
+      if( (flags3 & MEM_Str)==0 && (flags3 & (MEM_Int|MEM_Real))!=0 ){
+        testcase( pIn3->flags & MEM_Int );
+        testcase( pIn3->flags & MEM_Real );
+        sqlite3VdbeMemStringify(pIn3, encoding, 1);
+        testcase( (flags3&MEM_Dyn) != (pIn3->flags&MEM_Dyn) );
+        flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask);
+      }
     }
-
     assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
-    ExpandBlob(pIn1);
-    ExpandBlob(pIn3);
-    u.ai.res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
+    if( flags1 & MEM_Zero ){
+      sqlite3VdbeMemExpandBlob(pIn1);
+      flags1 &= ~MEM_Zero;
+    }
+    if( flags3 & MEM_Zero ){
+      sqlite3VdbeMemExpandBlob(pIn3);
+      flags3 &= ~MEM_Zero;
+    }
+    res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
   }
   switch( pOp->opcode ){
-    case OP_Eq:    u.ai.res = u.ai.res==0;     break;
-    case OP_Ne:    u.ai.res = u.ai.res!=0;     break;
-    case OP_Lt:    u.ai.res = u.ai.res<0;      break;
-    case OP_Le:    u.ai.res = u.ai.res<=0;     break;
-    case OP_Gt:    u.ai.res = u.ai.res>0;      break;
-    default:       u.ai.res = u.ai.res>=0;     break;
+    case OP_Eq:    res = res==0;     break;
+    case OP_Ne:    res = res!=0;     break;
+    case OP_Lt:    res = res<0;      break;
+    case OP_Le:    res = res<=0;     break;
+    case OP_Gt:    res = res>0;      break;
+    default:       res = res>=0;     break;
   }
 
+  /* Undo any changes made by applyAffinity() to the input registers. */
+  assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );
+  pIn1->flags = flags1;
+  assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );
+  pIn3->flags = flags3;
+
   if( pOp->p5 & SQLITE_STOREP2 ){
     pOut = &aMem[pOp->p2];
     memAboutToChange(p, pOut);
     MemSetTypeFlag(pOut, MEM_Int);
-    pOut->u.i = u.ai.res;
+    pOut->u.i = res;
     REGISTER_TRACE(pOp->p2, pOut);
-  }else if( u.ai.res ){
-    pc = pOp->p2-1;
+  }else{
+    VdbeBranchTaken(res!=0, (pOp->p5 & SQLITE_NULLEQ)?2:3);
+    if( res ){
+      goto jump_to_p2;
+    }
   }
-
-  /* Undo any changes made by applyAffinity() to the input registers. */
-  pIn1->flags = (pIn1->flags&~MEM_TypeMask) | (u.ai.flags1&MEM_TypeMask);
-  pIn3->flags = (pIn3->flags&~MEM_TypeMask) | (u.ai.flags3&MEM_TypeMask);
   break;
 }
 
@@ -65265,23 +79217,32 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
 ** Set the permutation used by the OP_Compare operator to be the array
 ** of integers in P4.
 **
-** The permutation is only valid until the next OP_Permutation, OP_Compare,
-** OP_Halt, or OP_ResultRow.  Typically the OP_Permutation should occur
-** immediately prior to the OP_Compare.
+** The permutation is only valid until the next OP_Compare that has
+** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 
+** occur immediately prior to the OP_Compare.
+**
+** The first integer in the P4 integer array is the length of the array
+** and does not become part of the permutation.
 */
 case OP_Permutation: {
   assert( pOp->p4type==P4_INTARRAY );
   assert( pOp->p4.ai );
-  aPermute = pOp->p4.ai;
+  aPermute = pOp->p4.ai + 1;
   break;
 }
 
-/* Opcode: Compare P1 P2 P3 P4 *
+/* Opcode: Compare P1 P2 P3 P4 P5
+** Synopsis: r[P1@P3] <-> r[P2@P3]
 **
 ** Compare two vectors of registers in reg(P1)..reg(P1+P3-1) (call this
 ** vector "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of
 ** the comparison for use by the next OP_Jump instruct.
 **
+** If P5 has the OPFLAG_PERMUTE bit set, then the order of comparison is
+** determined by the most recent OP_Permutation operator.  If the
+** OPFLAG_PERMUTE bit is clear, then register are compared in sequential
+** order.
+**
 ** P4 is a KeyInfo structure that defines collating sequences and sort
 ** orders for the comparison.  The permutation applies to registers
 ** only.  The KeyInfo elements are used sequentially.
@@ -65291,7 +79252,6 @@ case OP_Permutation: {
 ** and strings are less than blobs.
 */
 case OP_Compare: {
-#if 0  /* local variables moved into u.aj */
   int n;
   int i;
   int p1;
@@ -65300,37 +79260,37 @@ case OP_Compare: {
   int idx;
   CollSeq *pColl;    /* Collating sequence to use on this term */
   int bRev;          /* True for DESCENDING sort order */
-#endif /* local variables moved into u.aj */
-
-  u.aj.n = pOp->p3;
-  u.aj.pKeyInfo = pOp->p4.pKeyInfo;
-  assert( u.aj.n>0 );
-  assert( u.aj.pKeyInfo!=0 );
-  u.aj.p1 = pOp->p1;
-  u.aj.p2 = pOp->p2;
+
+  if( (pOp->p5 & OPFLAG_PERMUTE)==0 ) aPermute = 0;
+  n = pOp->p3;
+  pKeyInfo = pOp->p4.pKeyInfo;
+  assert( n>0 );
+  assert( pKeyInfo!=0 );
+  p1 = pOp->p1;
+  p2 = pOp->p2;
 #if SQLITE_DEBUG
   if( aPermute ){
     int k, mx = 0;
-    for(k=0; k<u.aj.n; k++) if( aPermute[k]>mx ) mx = aPermute[k];
-    assert( u.aj.p1>0 && u.aj.p1+mx<=p->nMem+1 );
-    assert( u.aj.p2>0 && u.aj.p2+mx<=p->nMem+1 );
+    for(k=0; k<n; k++) if( aPermute[k]>mx ) mx = aPermute[k];
+    assert( p1>0 && p1+mx<=(p->nMem+1 - p->nCursor)+1 );
+    assert( p2>0 && p2+mx<=(p->nMem+1 - p->nCursor)+1 );
   }else{
-    assert( u.aj.p1>0 && u.aj.p1+u.aj.n<=p->nMem+1 );
-    assert( u.aj.p2>0 && u.aj.p2+u.aj.n<=p->nMem+1 );
+    assert( p1>0 && p1+n<=(p->nMem+1 - p->nCursor)+1 );
+    assert( p2>0 && p2+n<=(p->nMem+1 - p->nCursor)+1 );
   }
 #endif /* SQLITE_DEBUG */
-  for(u.aj.i=0; u.aj.i<u.aj.n; u.aj.i++){
-    u.aj.idx = aPermute ? aPermute[u.aj.i] : u.aj.i;
-    assert( memIsValid(&aMem[u.aj.p1+u.aj.idx]) );
-    assert( memIsValid(&aMem[u.aj.p2+u.aj.idx]) );
-    REGISTER_TRACE(u.aj.p1+u.aj.idx, &aMem[u.aj.p1+u.aj.idx]);
-    REGISTER_TRACE(u.aj.p2+u.aj.idx, &aMem[u.aj.p2+u.aj.idx]);
-    assert( u.aj.i<u.aj.pKeyInfo->nField );
-    u.aj.pColl = u.aj.pKeyInfo->aColl[u.aj.i];
-    u.aj.bRev = u.aj.pKeyInfo->aSortOrder[u.aj.i];
-    iCompare = sqlite3MemCompare(&aMem[u.aj.p1+u.aj.idx], &aMem[u.aj.p2+u.aj.idx], u.aj.pColl);
+  for(i=0; i<n; i++){
+    idx = aPermute ? aPermute[i] : i;
+    assert( memIsValid(&aMem[p1+idx]) );
+    assert( memIsValid(&aMem[p2+idx]) );
+    REGISTER_TRACE(p1+idx, &aMem[p1+idx]);
+    REGISTER_TRACE(p2+idx, &aMem[p2+idx]);
+    assert( i<pKeyInfo->nField );
+    pColl = pKeyInfo->aColl[i];
+    bRev = pKeyInfo->aSortOrder[i];
+    iCompare = sqlite3MemCompare(&aMem[p1+idx], &aMem[p2+idx], pColl);
     if( iCompare ){
-      if( u.aj.bRev ) iCompare = -iCompare;
+      if( bRev ) iCompare = -iCompare;
       break;
     }
   }
@@ -65346,16 +79306,17 @@ case OP_Compare: {
 */
 case OP_Jump: {             /* jump */
   if( iCompare<0 ){
-    pc = pOp->p1 - 1;
+    VdbeBranchTaken(0,3); pOp = &aOp[pOp->p1 - 1];
   }else if( iCompare==0 ){
-    pc = pOp->p2 - 1;
+    VdbeBranchTaken(1,3); pOp = &aOp[pOp->p2 - 1];
   }else{
-    pc = pOp->p3 - 1;
+    VdbeBranchTaken(2,3); pOp = &aOp[pOp->p3 - 1];
   }
   break;
 }
 
 /* Opcode: And P1 P2 P3 * *
+** Synopsis: r[P3]=(r[P1] && r[P2])
 **
 ** Take the logical AND of the values in registers P1 and P2 and
 ** write the result into register P3.
@@ -65365,6 +79326,7 @@ case OP_Jump: {             /* jump */
 ** a NULL output.
 */
 /* Opcode: Or P1 P2 P3 * *
+** Synopsis: r[P3]=(r[P1] || r[P2])
 **
 ** Take the logical OR of the values in register P1 and P2 and
 ** store the answer in register P3.
@@ -65375,41 +79337,40 @@ case OP_Jump: {             /* jump */
 */
 case OP_And:              /* same as TK_AND, in1, in2, out3 */
 case OP_Or: {             /* same as TK_OR, in1, in2, out3 */
-#if 0  /* local variables moved into u.ak */
   int v1;    /* Left operand:  0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
   int v2;    /* Right operand: 0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
-#endif /* local variables moved into u.ak */
 
   pIn1 = &aMem[pOp->p1];
   if( pIn1->flags & MEM_Null ){
-    u.ak.v1 = 2;
+    v1 = 2;
   }else{
-    u.ak.v1 = sqlite3VdbeIntValue(pIn1)!=0;
+    v1 = sqlite3VdbeIntValue(pIn1)!=0;
   }
   pIn2 = &aMem[pOp->p2];
   if( pIn2->flags & MEM_Null ){
-    u.ak.v2 = 2;
+    v2 = 2;
   }else{
-    u.ak.v2 = sqlite3VdbeIntValue(pIn2)!=0;
+    v2 = sqlite3VdbeIntValue(pIn2)!=0;
   }
   if( pOp->opcode==OP_And ){
     static const unsigned char and_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };
-    u.ak.v1 = and_logic[u.ak.v1*3+u.ak.v2];
+    v1 = and_logic[v1*3+v2];
   }else{
     static const unsigned char or_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };
-    u.ak.v1 = or_logic[u.ak.v1*3+u.ak.v2];
+    v1 = or_logic[v1*3+v2];
   }
   pOut = &aMem[pOp->p3];
-  if( u.ak.v1==2 ){
+  if( v1==2 ){
     MemSetTypeFlag(pOut, MEM_Null);
   }else{
-    pOut->u.i = u.ak.v1;
+    pOut->u.i = v1;
     MemSetTypeFlag(pOut, MEM_Int);
   }
   break;
 }
 
 /* Opcode: Not P1 P2 * * *
+** Synopsis: r[P2]= !r[P1]
 **
 ** Interpret the value in register P1 as a boolean value.  Store the
 ** boolean complement in register P2.  If the value in register P1 is 
@@ -65418,15 +79379,16 @@ case OP_Or: {             /* same as TK_OR, in1, in2, out3 */
 case OP_Not: {                /* same as TK_NOT, in1, out2 */
   pIn1 = &aMem[pOp->p1];
   pOut = &aMem[pOp->p2];
-  if( pIn1->flags & MEM_Null ){
-    sqlite3VdbeMemSetNull(pOut);
-  }else{
-    sqlite3VdbeMemSetInt64(pOut, !sqlite3VdbeIntValue(pIn1));
+  sqlite3VdbeMemSetNull(pOut);
+  if( (pIn1->flags & MEM_Null)==0 ){
+    pOut->flags = MEM_Int;
+    pOut->u.i = !sqlite3VdbeIntValue(pIn1);
   }
   break;
 }
 
 /* Opcode: BitNot P1 P2 * * *
+** Synopsis: r[P1]= ~r[P1]
 **
 ** Interpret the content of register P1 as an integer.  Store the
 ** ones-complement of the P1 value into register P2.  If P1 holds
@@ -65435,90 +79397,99 @@ case OP_Not: {                /* same as TK_NOT, in1, out2 */
 case OP_BitNot: {             /* same as TK_BITNOT, in1, out2 */
   pIn1 = &aMem[pOp->p1];
   pOut = &aMem[pOp->p2];
-  if( pIn1->flags & MEM_Null ){
-    sqlite3VdbeMemSetNull(pOut);
-  }else{
-    sqlite3VdbeMemSetInt64(pOut, ~sqlite3VdbeIntValue(pIn1));
+  sqlite3VdbeMemSetNull(pOut);
+  if( (pIn1->flags & MEM_Null)==0 ){
+    pOut->flags = MEM_Int;
+    pOut->u.i = ~sqlite3VdbeIntValue(pIn1);
   }
   break;
 }
 
 /* Opcode: Once P1 P2 * * *
 **
-** Jump to P2 if the value in register P1 is a not null or zero.  If
-** the value is NULL or zero, fall through and change the P1 register
-** to an integer 1.
+** Check the "once" flag number P1. If it is set, jump to instruction P2. 
+** Otherwise, set the flag and fall through to the next instruction.
+** In other words, this opcode causes all following opcodes up through P2
+** (but not including P2) to run just once and to be skipped on subsequent
+** times through the loop.
 **
-** When P1 is not used otherwise in a program, this opcode falls through
-** once and jumps on all subsequent invocations.  It is the equivalent
-** of "OP_If P1 P2", followed by "OP_Integer 1 P1".
+** All "once" flags are initially cleared whenever a prepared statement
+** first begins to run.
 */
+case OP_Once: {             /* jump */
+  assert( pOp->p1<p->nOnceFlag );
+  VdbeBranchTaken(p->aOnceFlag[pOp->p1]!=0, 2);
+  if( p->aOnceFlag[pOp->p1] ){
+    goto jump_to_p2;
+  }else{
+    p->aOnceFlag[pOp->p1] = 1;
+  }
+  break;
+}
+
 /* Opcode: If P1 P2 P3 * *
 **
 ** Jump to P2 if the value in register P1 is true.  The value
 ** is considered true if it is numeric and non-zero.  If the value
-** in P1 is NULL then take the jump if P3 is true.
+** in P1 is NULL then take the jump if and only if P3 is non-zero.
 */
 /* Opcode: IfNot P1 P2 P3 * *
 **
 ** Jump to P2 if the value in register P1 is False.  The value
-** is considered true if it has a numeric value of zero.  If the value
-** in P1 is NULL then take the jump if P3 is true.
+** is considered false if it has a numeric value of zero.  If the value
+** in P1 is NULL then take the jump if and only if P3 is non-zero.
 */
-case OP_Once:               /* jump, in1 */
 case OP_If:                 /* jump, in1 */
 case OP_IfNot: {            /* jump, in1 */
-#if 0  /* local variables moved into u.al */
   int c;
-#endif /* local variables moved into u.al */
   pIn1 = &aMem[pOp->p1];
   if( pIn1->flags & MEM_Null ){
-    u.al.c = pOp->p3;
+    c = pOp->p3;
   }else{
 #ifdef SQLITE_OMIT_FLOATING_POINT
-    u.al.c = sqlite3VdbeIntValue(pIn1)!=0;
+    c = sqlite3VdbeIntValue(pIn1)!=0;
 #else
-    u.al.c = sqlite3VdbeRealValue(pIn1)!=0.0;
+    c = sqlite3VdbeRealValue(pIn1)!=0.0;
 #endif
-    if( pOp->opcode==OP_IfNot ) u.al.c = !u.al.c;
+    if( pOp->opcode==OP_IfNot ) c = !c;
   }
-  if( u.al.c ){
-    pc = pOp->p2-1;
-  }else if( pOp->opcode==OP_Once ){
-    assert( (pIn1->flags & (MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))==0 );
-    memAboutToChange(p, pIn1);
-    pIn1->flags = MEM_Int;
-    pIn1->u.i = 1;
-    REGISTER_TRACE(pOp->p1, pIn1);
+  VdbeBranchTaken(c!=0, 2);
+  if( c ){
+    goto jump_to_p2;
   }
   break;
 }
 
 /* Opcode: IsNull P1 P2 * * *
+** Synopsis:  if r[P1]==NULL goto P2
 **
 ** Jump to P2 if the value in register P1 is NULL.
 */
 case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */
   pIn1 = &aMem[pOp->p1];
+  VdbeBranchTaken( (pIn1->flags & MEM_Null)!=0, 2);
   if( (pIn1->flags & MEM_Null)!=0 ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
   }
   break;
 }
 
 /* Opcode: NotNull P1 P2 * * *
+** Synopsis: if r[P1]!=NULL goto P2
 **
 ** Jump to P2 if the value in register P1 is not NULL.  
 */
 case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
   pIn1 = &aMem[pOp->p1];
+  VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);
   if( (pIn1->flags & MEM_Null)==0 ){
-    pc = pOp->p2 - 1;
+    goto jump_to_p2;
   }
   break;
 }
 
 /* Opcode: Column P1 P2 P3 P4 P5
+** Synopsis:  r[P3]=PX
 **
 ** Interpret the data that cursor P1 points to as a structure built using
 ** the MakeRecord instruction.  (See the MakeRecord opcode for additional
@@ -65536,302 +79507,255 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
 ** then the cache of the cursor is reset prior to extracting the column.
 ** The first OP_Column against a pseudo-table after the value of the content
 ** register has changed should have this bit set.
+**
+** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 when
+** the result is guaranteed to only be used as the argument of a length()
+** or typeof() function, respectively.  The loading of large blobs can be
+** skipped for length() and all content loading can be skipped for typeof().
 */
 case OP_Column: {
-#if 0  /* local variables moved into u.am */
-  u32 payloadSize;   /* Number of bytes in the record */
-  i64 payloadSize64; /* Number of bytes in the record */
-  int p1;            /* P1 value of the opcode */
   int p2;            /* column number to retrieve */
   VdbeCursor *pC;    /* The VDBE cursor */
-  char *zRec;        /* Pointer to complete record-data */
   BtCursor *pCrsr;   /* The BTree cursor */
-  u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
   u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
-  int nField;        /* number of fields in the record */
   int len;           /* The length of the serialized data for the column */
   int i;             /* Loop counter */
-  char *zData;       /* Part of the record being decoded */
   Mem *pDest;        /* Where to write the extracted value */
   Mem sMem;          /* For storing the record being decoded */
-  u8 *zIdx;          /* Index into header */
-  u8 *zEndHdr;       /* Pointer to first byte after the header */
+  const u8 *zData;   /* Part of the record being decoded */
+  const u8 *zHdr;    /* Next unparsed byte of the header */
+  const u8 *zEndHdr; /* Pointer to first byte after the header */
   u32 offset;        /* Offset into the data */
-  u32 szField;       /* Number of bytes in the content of a field */
-  int szHdr;         /* Size of the header size field at start of record */
-  int avail;         /* Number of bytes of available data */
+  u64 offset64;      /* 64-bit offset */
+  u32 avail;         /* Number of bytes of available data */
   u32 t;             /* A type code from the record header */
   Mem *pReg;         /* PseudoTable input register */
-#endif /* local variables moved into u.am */
-
-
-  u.am.p1 = pOp->p1;
-  u.am.p2 = pOp->p2;
-  u.am.pC = 0;
-  memset(&u.am.sMem, 0, sizeof(u.am.sMem));
-  assert( u.am.p1<p->nCursor );
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  u.am.pDest = &aMem[pOp->p3];
-  memAboutToChange(p, u.am.pDest);
-  u.am.zRec = 0;
 
-  /* This block sets the variable u.am.payloadSize to be the total number of
-  ** bytes in the record.
-  **
-  ** u.am.zRec is set to be the complete text of the record if it is available.
-  ** The complete record text is always available for pseudo-tables
-  ** If the record is stored in a cursor, the complete record text
-  ** might be available in the  u.am.pC->aRow cache.  Or it might not be.
-  ** If the data is unavailable,  u.am.zRec is set to NULL.
-  **
-  ** We also compute the number of columns in the record.  For cursors,
-  ** the number of columns is stored in the VdbeCursor.nField element.
-  */
-  u.am.pC = p->apCsr[u.am.p1];
-  assert( u.am.pC!=0 );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  assert( u.am.pC->pVtabCursor==0 );
-#endif
-  u.am.pCrsr = u.am.pC->pCursor;
-  if( u.am.pCrsr!=0 ){
-    /* The record is stored in a B-Tree */
-    rc = sqlite3VdbeCursorMoveto(u.am.pC);
-    if( rc ) goto abort_due_to_error;
-    if( u.am.pC->nullRow ){
-      u.am.payloadSize = 0;
-    }else if( u.am.pC->cacheStatus==p->cacheCtr ){
-      u.am.payloadSize = u.am.pC->payloadSize;
-      u.am.zRec = (char*)u.am.pC->aRow;
-    }else if( u.am.pC->isIndex ){
-      assert( sqlite3BtreeCursorIsValid(u.am.pCrsr) );
-      VVA_ONLY(rc =) sqlite3BtreeKeySize(u.am.pCrsr, &u.am.payloadSize64);
-      assert( rc==SQLITE_OK );   /* True because of CursorMoveto() call above */
-      /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
-      ** payload size, so it is impossible for u.am.payloadSize64 to be
-      ** larger than 32 bits. */
-      assert( (u.am.payloadSize64 & SQLITE_MAX_U32)==(u64)u.am.payloadSize64 );
-      u.am.payloadSize = (u32)u.am.payloadSize64;
-    }else{
-      assert( sqlite3BtreeCursorIsValid(u.am.pCrsr) );
-      VVA_ONLY(rc =) sqlite3BtreeDataSize(u.am.pCrsr, &u.am.payloadSize);
-      assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
-    }
-  }else if( ALWAYS(u.am.pC->pseudoTableReg>0) ){
-    u.am.pReg = &aMem[u.am.pC->pseudoTableReg];
-    assert( u.am.pReg->flags & MEM_Blob );
-    assert( memIsValid(u.am.pReg) );
-    u.am.payloadSize = u.am.pReg->n;
-    u.am.zRec = u.am.pReg->z;
-    u.am.pC->cacheStatus = (pOp->p5&OPFLAG_CLEARCACHE) ? CACHE_STALE : p->cacheCtr;
-    assert( u.am.payloadSize==0 || u.am.zRec!=0 );
-  }else{
-    /* Consider the row to be NULL */
-    u.am.payloadSize = 0;
-  }
-
-  /* If u.am.payloadSize is 0, then just store a NULL.  This can happen because of
-  ** nullRow or because of a corrupt database. */
-  if( u.am.payloadSize==0 ){
-    MemSetTypeFlag(u.am.pDest, MEM_Null);
-    goto op_column_out;
-  }
-  assert( db->aLimit[SQLITE_LIMIT_LENGTH]>=0 );
-  if( u.am.payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-    goto too_big;
-  }
+  pC = p->apCsr[pOp->p1];
+  p2 = pOp->p2;
 
-  u.am.nField = u.am.pC->nField;
-  assert( u.am.p2<u.am.nField );
+  /* If the cursor cache is stale, bring it up-to-date */
+  rc = sqlite3VdbeCursorMoveto(&pC, &p2);
+  if( rc ) goto abort_due_to_error;
 
-  /* Read and parse the table header.  Store the results of the parse
-  ** into the record header cache fields of the cursor.
-  */
-  u.am.aType = u.am.pC->aType;
-  if( u.am.pC->cacheStatus==p->cacheCtr ){
-    u.am.aOffset = u.am.pC->aOffset;
-  }else{
-    assert(u.am.aType);
-    u.am.avail = 0;
-    u.am.pC->aOffset = u.am.aOffset = &u.am.aType[u.am.nField];
-    u.am.pC->payloadSize = u.am.payloadSize;
-    u.am.pC->cacheStatus = p->cacheCtr;
-
-    /* Figure out how many bytes are in the header */
-    if( u.am.zRec ){
-      u.am.zData = u.am.zRec;
-    }else{
-      if( u.am.pC->isIndex ){
-        u.am.zData = (char*)sqlite3BtreeKeyFetch(u.am.pCrsr, &u.am.avail);
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  pDest = &aMem[pOp->p3];
+  memAboutToChange(p, pDest);
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  assert( pC!=0 );
+  assert( p2<pC->nField );
+  aOffset = pC->aOffset;
+  assert( pC->eCurType!=CURTYPE_VTAB );
+  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
+  assert( pC->eCurType!=CURTYPE_SORTER );
+  pCrsr = pC->uc.pCursor;
+
+  if( pC->cacheStatus!=p->cacheCtr ){                /*OPTIMIZATION-IF-FALSE*/
+    if( pC->nullRow ){
+      if( pC->eCurType==CURTYPE_PSEUDO ){
+        assert( pC->uc.pseudoTableReg>0 );
+        pReg = &aMem[pC->uc.pseudoTableReg];
+        assert( pReg->flags & MEM_Blob );
+        assert( memIsValid(pReg) );
+        pC->payloadSize = pC->szRow = avail = pReg->n;
+        pC->aRow = (u8*)pReg->z;
       }else{
-        u.am.zData = (char*)sqlite3BtreeDataFetch(u.am.pCrsr, &u.am.avail);
+        sqlite3VdbeMemSetNull(pDest);
+        goto op_column_out;
       }
-      /* If KeyFetch()/DataFetch() managed to get the entire payload,
-      ** save the payload in the u.am.pC->aRow cache.  That will save us from
-      ** having to make additional calls to fetch the content portion of
-      ** the record.
-      */
-      assert( u.am.avail>=0 );
-      if( u.am.payloadSize <= (u32)u.am.avail ){
-        u.am.zRec = u.am.zData;
-        u.am.pC->aRow = (u8*)u.am.zData;
+    }else{
+      assert( pC->eCurType==CURTYPE_BTREE );
+      assert( pCrsr );
+      assert( sqlite3BtreeCursorIsValid(pCrsr) );
+      pC->payloadSize = sqlite3BtreePayloadSize(pCrsr);
+      pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &avail);
+      assert( avail<=65536 );  /* Maximum page size is 64KiB */
+      if( pC->payloadSize <= (u32)avail ){
+        pC->szRow = pC->payloadSize;
+      }else if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+        goto too_big;
       }else{
-        u.am.pC->aRow = 0;
+        pC->szRow = avail;
       }
     }
-    /* The following assert is true in all cases accept when
-    ** the database file has been corrupted externally.
-    **    assert( u.am.zRec!=0 || u.am.avail>=u.am.payloadSize || u.am.avail>=9 ); */
-    u.am.szHdr = getVarint32((u8*)u.am.zData, u.am.offset);
+    pC->cacheStatus = p->cacheCtr;
+    pC->iHdrOffset = getVarint32(pC->aRow, offset);
+    pC->nHdrParsed = 0;
+    aOffset[0] = offset;
 
-    /* Make sure a corrupt database has not given us an oversize header.
-    ** Do this now to avoid an oversize memory allocation.
-    **
-    ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte
-    ** types use so much data space that there can only be 4096 and 32 of
-    ** them, respectively.  So the maximum header length results from a
-    ** 3-byte type for each of the maximum of 32768 columns plus three
-    ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
-    */
-    if( u.am.offset > 98307 ){
-      rc = SQLITE_CORRUPT_BKPT;
-      goto op_column_out;
-    }
 
-    /* Compute in u.am.len the number of bytes of data we need to read in order
-    ** to get u.am.nField type values.  u.am.offset is an upper bound on this.  But
-    ** u.am.nField might be significantly less than the true number of columns
-    ** in the table, and in that case, 5*u.am.nField+3 might be smaller than u.am.offset.
-    ** We want to minimize u.am.len in order to limit the size of the memory
-    ** allocation, especially if a corrupt database file has caused u.am.offset
-    ** to be oversized. Offset is limited to 98307 above.  But 98307 might
-    ** still exceed Robson memory allocation limits on some configurations.
-    ** On systems that cannot tolerate large memory allocations, u.am.nField*5+3
-    ** will likely be much smaller since u.am.nField will likely be less than
-    ** 20 or so.  This insures that Robson memory allocation limits are
-    ** not exceeded even for corrupt database files.
-    */
-    u.am.len = u.am.nField*5 + 3;
-    if( u.am.len > (int)u.am.offset ) u.am.len = (int)u.am.offset;
-
-    /* The KeyFetch() or DataFetch() above are fast and will get the entire
-    ** record header in most cases.  But they will fail to get the complete
-    ** record header if the record header does not fit on a single page
-    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
-    ** acquire the complete header text.
-    */
-    if( !u.am.zRec && u.am.avail<u.am.len ){
-      u.am.sMem.flags = 0;
-      u.am.sMem.db = 0;
-      rc = sqlite3VdbeMemFromBtree(u.am.pCrsr, 0, u.am.len, u.am.pC->isIndex, &u.am.sMem);
-      if( rc!=SQLITE_OK ){
-        goto op_column_out;
+    if( avail<offset ){      /*OPTIMIZATION-IF-FALSE*/
+      /* pC->aRow does not have to hold the entire row, but it does at least
+      ** need to cover the header of the record.  If pC->aRow does not contain
+      ** the complete header, then set it to zero, forcing the header to be
+      ** dynamically allocated. */
+      pC->aRow = 0;
+      pC->szRow = 0;
+
+      /* Make sure a corrupt database has not given us an oversize header.
+      ** Do this now to avoid an oversize memory allocation.
+      **
+      ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte
+      ** types use so much data space that there can only be 4096 and 32 of
+      ** them, respectively.  So the maximum header length results from a
+      ** 3-byte type for each of the maximum of 32768 columns plus three
+      ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
+      */
+      if( offset > 98307 || offset > pC->payloadSize ){
+        rc = SQLITE_CORRUPT_BKPT;
+        goto abort_due_to_error;
       }
-      u.am.zData = u.am.sMem.z;
+    }else if( offset>0 ){ /*OPTIMIZATION-IF-TRUE*/
+      /* The following goto is an optimization.  It can be omitted and
+      ** everything will still work.  But OP_Column is measurably faster
+      ** by skipping the subsequent conditional, which is always true.
+      */
+      zData = pC->aRow;
+      assert( pC->nHdrParsed<=p2 );         /* Conditional skipped */
+      goto op_column_read_header;
     }
-    u.am.zEndHdr = (u8 *)&u.am.zData[u.am.len];
-    u.am.zIdx = (u8 *)&u.am.zData[u.am.szHdr];
+  }
 
-    /* Scan the header and use it to fill in the u.am.aType[] and u.am.aOffset[]
-    ** arrays.  u.am.aType[u.am.i] will contain the type integer for the u.am.i-th
-    ** column and u.am.aOffset[u.am.i] will contain the u.am.offset from the beginning
-    ** of the record to the start of the data for the u.am.i-th column
+  /* Make sure at least the first p2+1 entries of the header have been
+  ** parsed and valid information is in aOffset[] and pC->aType[].
+  */
+  if( pC->nHdrParsed<=p2 ){
+    /* If there is more header available for parsing in the record, try
+    ** to extract additional fields up through the p2+1-th field 
     */
-    for(u.am.i=0; u.am.i<u.am.nField; u.am.i++){
-      if( u.am.zIdx<u.am.zEndHdr ){
-        u.am.aOffset[u.am.i] = u.am.offset;
-        if( u.am.zIdx[0]<0x80 ){
-          u.am.t = u.am.zIdx[0];
-          u.am.zIdx++;
+    if( pC->iHdrOffset<aOffset[0] ){
+      /* Make sure zData points to enough of the record to cover the header. */
+      if( pC->aRow==0 ){
+        memset(&sMem, 0, sizeof(sMem));
+        rc = sqlite3VdbeMemFromBtree(pCrsr, 0, aOffset[0], !pC->isTable, &sMem);
+        if( rc!=SQLITE_OK ) goto abort_due_to_error;
+        zData = (u8*)sMem.z;
+      }else{
+        zData = pC->aRow;
+      }
+  
+      /* Fill in pC->aType[i] and aOffset[i] values through the p2-th field. */
+    op_column_read_header:
+      i = pC->nHdrParsed;
+      offset64 = aOffset[i];
+      zHdr = zData + pC->iHdrOffset;
+      zEndHdr = zData + aOffset[0];
+      do{
+        if( (t = zHdr[0])<0x80 ){
+          zHdr++;
+          offset64 += sqlite3VdbeOneByteSerialTypeLen(t);
         }else{
-          u.am.zIdx += sqlite3GetVarint32(u.am.zIdx, &u.am.t);
+          zHdr += sqlite3GetVarint32(zHdr, &t);
+          offset64 += sqlite3VdbeSerialTypeLen(t);
         }
-        u.am.aType[u.am.i] = u.am.t;
-        u.am.szField = sqlite3VdbeSerialTypeLen(u.am.t);
-        u.am.offset += u.am.szField;
-        if( u.am.offset<u.am.szField ){  /* True if u.am.offset overflows */
-          u.am.zIdx = &u.am.zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
-          break;
-        }
-      }else{
-        /* If u.am.i is less that u.am.nField, then there are less fields in this
-        ** record than SetNumColumns indicated there are columns in the
-        ** table. Set the u.am.offset for any extra columns not present in
-        ** the record to 0. This tells code below to store a NULL
-        ** instead of deserializing a value from the record.
-        */
-        u.am.aOffset[u.am.i] = 0;
+        pC->aType[i++] = t;
+        aOffset[i] = (u32)(offset64 & 0xffffffff);
+      }while( i<=p2 && zHdr<zEndHdr );
+
+      /* The record is corrupt if any of the following are true:
+      ** (1) the bytes of the header extend past the declared header size
+      ** (2) the entire header was used but not all data was used
+      ** (3) the end of the data extends beyond the end of the record.
+      */
+      if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset64!=pC->payloadSize))
+       || (offset64 > pC->payloadSize)
+      ){
+        if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
+        rc = SQLITE_CORRUPT_BKPT;
+        goto abort_due_to_error;
       }
+
+      pC->nHdrParsed = i;
+      pC->iHdrOffset = (u32)(zHdr - zData);
+      if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);
+    }else{
+      t = 0;
     }
-    sqlite3VdbeMemRelease(&u.am.sMem);
-    u.am.sMem.flags = MEM_Null;
 
-    /* If we have read more header data than was contained in the header,
-    ** or if the end of the last field appears to be past the end of the
-    ** record, or if the end of the last field appears to be before the end
-    ** of the record (when all fields present), then we must be dealing
-    ** with a corrupt database.
+    /* If after trying to extract new entries from the header, nHdrParsed is
+    ** still not up to p2, that means that the record has fewer than p2
+    ** columns.  So the result will be either the default value or a NULL.
     */
-    if( (u.am.zIdx > u.am.zEndHdr) || (u.am.offset > u.am.payloadSize)
-         || (u.am.zIdx==u.am.zEndHdr && u.am.offset!=u.am.payloadSize) ){
-      rc = SQLITE_CORRUPT_BKPT;
+    if( pC->nHdrParsed<=p2 ){
+      if( pOp->p4type==P4_MEM ){
+        sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
+      }else{
+        sqlite3VdbeMemSetNull(pDest);
+      }
       goto op_column_out;
     }
+  }else{
+    t = pC->aType[p2];
   }
 
-  /* Get the column information. If u.am.aOffset[u.am.p2] is non-zero, then
-  ** deserialize the value from the record. If u.am.aOffset[u.am.p2] is zero,
-  ** then there are not enough fields in the record to satisfy the
-  ** request.  In this case, set the value NULL or to P4 if P4 is
-  ** a pointer to a Mem object.
+  /* Extract the content for the p2+1-th column.  Control can only
+  ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are
+  ** all valid.
   */
-  if( u.am.aOffset[u.am.p2] ){
-    assert( rc==SQLITE_OK );
-    if( u.am.zRec ){
-      MemReleaseExt(u.am.pDest);
-      sqlite3VdbeSerialGet((u8 *)&u.am.zRec[u.am.aOffset[u.am.p2]], u.am.aType[u.am.p2], u.am.pDest);
+  assert( p2<pC->nHdrParsed );
+  assert( rc==SQLITE_OK );
+  assert( sqlite3VdbeCheckMemInvariants(pDest) );
+  if( VdbeMemDynamic(pDest) ){
+    sqlite3VdbeMemSetNull(pDest);
+  }
+  assert( t==pC->aType[p2] );
+  if( pC->szRow>=aOffset[p2+1] ){
+    /* This is the common case where the desired content fits on the original
+    ** page - where the content is not on an overflow page */
+    zData = pC->aRow + aOffset[p2];
+    if( t<12 ){
+      sqlite3VdbeSerialGet(zData, t, pDest);
     }else{
-      u.am.len = sqlite3VdbeSerialTypeLen(u.am.aType[u.am.p2]);
-      sqlite3VdbeMemMove(&u.am.sMem, u.am.pDest);
-      rc = sqlite3VdbeMemFromBtree(u.am.pCrsr, u.am.aOffset[u.am.p2], u.am.len, u.am.pC->isIndex, &u.am.sMem);
-      if( rc!=SQLITE_OK ){
-        goto op_column_out;
+      /* If the column value is a string, we need a persistent value, not
+      ** a MEM_Ephem value.  This branch is a fast short-cut that is equivalent
+      ** to calling sqlite3VdbeSerialGet() and sqlite3VdbeDeephemeralize().
+      */
+      static const u16 aFlag[] = { MEM_Blob, MEM_Str|MEM_Term };
+      pDest->n = len = (t-12)/2;
+      pDest->enc = encoding;
+      if( pDest->szMalloc < len+2 ){
+        pDest->flags = MEM_Null;
+        if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;
+      }else{
+        pDest->z = pDest->zMalloc;
       }
-      u.am.zData = u.am.sMem.z;
-      sqlite3VdbeSerialGet((u8*)u.am.zData, u.am.aType[u.am.p2], u.am.pDest);
+      memcpy(pDest->z, zData, len);
+      pDest->z[len] = 0;
+      pDest->z[len+1] = 0;
+      pDest->flags = aFlag[t&1];
     }
-    u.am.pDest->enc = encoding;
   }else{
-    if( pOp->p4type==P4_MEM ){
-      sqlite3VdbeMemShallowCopy(u.am.pDest, pOp->p4.pMem, MEM_Static);
+    pDest->enc = encoding;
+    /* This branch happens only when content is on overflow pages */
+    if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
+          && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))
+     || (len = sqlite3VdbeSerialTypeLen(t))==0
+    ){
+      /* Content is irrelevant for
+      **    1. the typeof() function,
+      **    2. the length(X) function if X is a blob, and
+      **    3. if the content length is zero.
+      ** So we might as well use bogus content rather than reading
+      ** content from disk. */
+      static u8 aZero[8];  /* This is the bogus content */
+      sqlite3VdbeSerialGet(aZero, t, pDest);
     }else{
-      MemSetTypeFlag(u.am.pDest, MEM_Null);
+      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, !pC->isTable,
+                                   pDest);
+      if( rc!=SQLITE_OK ) goto abort_due_to_error;
+      sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);
+      pDest->flags &= ~MEM_Ephem;
     }
   }
 
-  /* If we dynamically allocated space to hold the data (in the
-  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
-  ** dynamically allocated space over to the u.am.pDest structure.
-  ** This prevents a memory copy.
-  */
-  if( u.am.sMem.zMalloc ){
-    assert( u.am.sMem.z==u.am.sMem.zMalloc );
-    assert( !(u.am.pDest->flags & MEM_Dyn) );
-    assert( !(u.am.pDest->flags & (MEM_Blob|MEM_Str)) || u.am.pDest->z==u.am.sMem.z );
-    u.am.pDest->flags &= ~(MEM_Ephem|MEM_Static);
-    u.am.pDest->flags |= MEM_Term;
-    u.am.pDest->z = u.am.sMem.z;
-    u.am.pDest->zMalloc = u.am.sMem.zMalloc;
-  }
-
-  rc = sqlite3VdbeMemMakeWriteable(u.am.pDest);
-
 op_column_out:
-  UPDATE_MAX_BLOBSIZE(u.am.pDest);
-  REGISTER_TRACE(pOp->p3, u.am.pDest);
+  UPDATE_MAX_BLOBSIZE(pDest);
+  REGISTER_TRACE(pOp->p3, pDest);
   break;
 }
 
 /* Opcode: Affinity P1 P2 * P4 *
+** Synopsis: affinity(r[P1@P2])
 **
 ** Apply affinities to a range of P2 registers starting with P1.
 **
@@ -65840,26 +79764,24 @@ op_column_out:
 ** memory cell in the range.
 */
 case OP_Affinity: {
-#if 0  /* local variables moved into u.an */
   const char *zAffinity;   /* The affinity to be applied */
   char cAff;               /* A single character of affinity */
-#endif /* local variables moved into u.an */
 
-  u.an.zAffinity = pOp->p4.z;
-  assert( u.an.zAffinity!=0 );
-  assert( u.an.zAffinity[pOp->p2]==0 );
+  zAffinity = pOp->p4.z;
+  assert( zAffinity!=0 );
+  assert( zAffinity[pOp->p2]==0 );
   pIn1 = &aMem[pOp->p1];
-  while( (u.an.cAff = *(u.an.zAffinity++))!=0 ){
-    assert( pIn1 <= &p->aMem[p->nMem] );
+  while( (cAff = *(zAffinity++))!=0 ){
+    assert( pIn1 <= &p->aMem[(p->nMem+1 - p->nCursor)] );
     assert( memIsValid(pIn1) );
-    ExpandBlob(pIn1);
-    applyAffinity(pIn1, u.an.cAff, encoding);
+    applyAffinity(pIn1, cAff, encoding);
     pIn1++;
   }
   break;
 }
 
 /* Opcode: MakeRecord P1 P2 P3 P4 *
+** Synopsis: r[P3]=mkrec(r[P1@P2])
 **
 ** Convert P2 registers beginning with P1 into the [record format]
 ** use as a data record in a database table or as a key
@@ -65872,16 +79794,15 @@ case OP_Affinity: {
 ** The mapping from character to affinity is given by the SQLITE_AFF_
 ** macros defined in sqliteInt.h.
 **
-** If P4 is NULL then all index fields have the affinity NONE.
+** If P4 is NULL then all index fields have the affinity BLOB.
 */
 case OP_MakeRecord: {
-#if 0  /* local variables moved into u.ao */
   u8 *zNewRecord;        /* A buffer to hold the data for the new record */
   Mem *pRec;             /* The new record */
   u64 nData;             /* Number of bytes of data space */
   int nHdr;              /* Number of bytes of header space */
   i64 nByte;             /* Data space required for this record */
-  int nZero;             /* Number of zero bytes at the end of the record */
+  i64 nZero;             /* Number of zero bytes at the end of the record */
   int nVarint;           /* Number of bytes in a varint */
   u32 serial_type;       /* Type field */
   Mem *pData0;           /* First field to be combined into the record */
@@ -65889,102 +79810,127 @@ case OP_MakeRecord: {
   int nField;            /* Number of fields in the record */
   char *zAffinity;       /* The affinity string for the record */
   int file_format;       /* File format to use for encoding */
-  int i;                 /* Space used in zNewRecord[] */
-  int len;               /* Length of a field */
-#endif /* local variables moved into u.ao */
+  int i;                 /* Space used in zNewRecord[] header */
+  int j;                 /* Space used in zNewRecord[] content */
+  u32 len;               /* Length of a field */
 
   /* Assuming the record contains N fields, the record format looks
   ** like this:
   **
   ** ------------------------------------------------------------------------
-  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 |
+  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
   ** ------------------------------------------------------------------------
   **
   ** Data(0) is taken from register P1.  Data(1) comes from register P1+1
-  ** and so froth.
+  ** and so forth.
   **
-  ** Each type field is a varint representing the serial type of the
+  ** Each type field is a varint representing the serial type of the 
   ** corresponding data element (see sqlite3VdbeSerialType()). The
   ** hdr-size field is also a varint which is the offset from the beginning
   ** of the record to data0.
   */
-  u.ao.nData = 0;         /* Number of bytes of data space */
-  u.ao.nHdr = 0;          /* Number of bytes of header space */
-  u.ao.nZero = 0;         /* Number of zero bytes at the end of the record */
-  u.ao.nField = pOp->p1;
-  u.ao.zAffinity = pOp->p4.z;
-  assert( u.ao.nField>0 && pOp->p2>0 && pOp->p2+u.ao.nField<=p->nMem+1 );
-  u.ao.pData0 = &aMem[u.ao.nField];
-  u.ao.nField = pOp->p2;
-  u.ao.pLast = &u.ao.pData0[u.ao.nField-1];
-  u.ao.file_format = p->minWriteFileFormat;
+  nData = 0;         /* Number of bytes of data space */
+  nHdr = 0;          /* Number of bytes of header space */
+  nZero = 0;         /* Number of zero bytes at the end of the record */
+  nField = pOp->p1;
+  zAffinity = pOp->p4.z;
+  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem+1 - p->nCursor)+1 );
+  pData0 = &aMem[nField];
+  nField = pOp->p2;
+  pLast = &pData0[nField-1];
+  file_format = p->minWriteFileFormat;
 
   /* Identify the output register */
   assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
   pOut = &aMem[pOp->p3];
   memAboutToChange(p, pOut);
 
-  /* Loop through the elements that will make up the record to figure
-  ** out how much space is required for the new record.
+  /* Apply the requested affinity to all inputs
   */
-  for(u.ao.pRec=u.ao.pData0; u.ao.pRec<=u.ao.pLast; u.ao.pRec++){
-    assert( memIsValid(u.ao.pRec) );
-    if( u.ao.zAffinity ){
-      applyAffinity(u.ao.pRec, u.ao.zAffinity[u.ao.pRec-u.ao.pData0], encoding);
-    }
-    if( u.ao.pRec->flags&MEM_Zero && u.ao.pRec->n>0 ){
-      sqlite3VdbeMemExpandBlob(u.ao.pRec);
-    }
-    u.ao.serial_type = sqlite3VdbeSerialType(u.ao.pRec, u.ao.file_format);
-    u.ao.len = sqlite3VdbeSerialTypeLen(u.ao.serial_type);
-    u.ao.nData += u.ao.len;
-    u.ao.nHdr += sqlite3VarintLen(u.ao.serial_type);
-    if( u.ao.pRec->flags & MEM_Zero ){
-      /* Only pure zero-filled BLOBs can be input to this Opcode.
-      ** We do not allow blobs with a prefix and a zero-filled tail. */
-      u.ao.nZero += u.ao.pRec->u.nZero;
-    }else if( u.ao.len ){
-      u.ao.nZero = 0;
-    }
+  assert( pData0<=pLast );
+  if( zAffinity ){
+    pRec = pData0;
+    do{
+      applyAffinity(pRec++, *(zAffinity++), encoding);
+      assert( zAffinity[0]==0 || pRec<=pLast );
+    }while( zAffinity[0] );
   }
 
-  /* Add the initial header varint and total the size */
-  u.ao.nHdr += u.ao.nVarint = sqlite3VarintLen(u.ao.nHdr);
-  if( u.ao.nVarint<sqlite3VarintLen(u.ao.nHdr) ){
-    u.ao.nHdr++;
+  /* Loop through the elements that will make up the record to figure
+  ** out how much space is required for the new record.
+  */
+  pRec = pLast;
+  do{
+    assert( memIsValid(pRec) );
+    pRec->uTemp = serial_type = sqlite3VdbeSerialType(pRec, file_format, &len);
+    if( pRec->flags & MEM_Zero ){
+      if( nData ){
+        if( sqlite3VdbeMemExpandBlob(pRec) ) goto no_mem;
+      }else{
+        nZero += pRec->u.nZero;
+        len -= pRec->u.nZero;
+      }
+    }
+    nData += len;
+    testcase( serial_type==127 );
+    testcase( serial_type==128 );
+    nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
+    if( pRec==pData0 ) break;
+    pRec--;
+  }while(1);
+
+  /* EVIDENCE-OF: R-22564-11647 The header begins with a single varint
+  ** which determines the total number of bytes in the header. The varint
+  ** value is the size of the header in bytes including the size varint
+  ** itself. */
+  testcase( nHdr==126 );
+  testcase( nHdr==127 );
+  if( nHdr<=126 ){
+    /* The common case */
+    nHdr += 1;
+  }else{
+    /* Rare case of a really large header */
+    nVarint = sqlite3VarintLen(nHdr);
+    nHdr += nVarint;
+    if( nVarint<sqlite3VarintLen(nHdr) ) nHdr++;
   }
-  u.ao.nByte = u.ao.nHdr+u.ao.nData-u.ao.nZero;
-  if( u.ao.nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+  nByte = nHdr+nData;
+  if( nByte+nZero>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
 
-  /* Make sure the output register has a buffer large enough to store
+  /* Make sure the output register has a buffer large enough to store 
   ** the new record. The output register (pOp->p3) is not allowed to
   ** be one of the input registers (because the following call to
-  ** sqlite3VdbeMemGrow() could clobber the value before it is used).
+  ** sqlite3VdbeMemClearAndResize() could clobber the value before it is used).
   */
-  if( sqlite3VdbeMemGrow(pOut, (int)u.ao.nByte, 0) ){
+  if( sqlite3VdbeMemClearAndResize(pOut, (int)nByte) ){
     goto no_mem;
   }
-  u.ao.zNewRecord = (u8 *)pOut->z;
+  zNewRecord = (u8 *)pOut->z;
 
   /* Write the record */
-  u.ao.i = putVarint32(u.ao.zNewRecord, u.ao.nHdr);
-  for(u.ao.pRec=u.ao.pData0; u.ao.pRec<=u.ao.pLast; u.ao.pRec++){
-    u.ao.serial_type = sqlite3VdbeSerialType(u.ao.pRec, u.ao.file_format);
-    u.ao.i += putVarint32(&u.ao.zNewRecord[u.ao.i], u.ao.serial_type);      /* serial type */
-  }
-  for(u.ao.pRec=u.ao.pData0; u.ao.pRec<=u.ao.pLast; u.ao.pRec++){  /* serial data */
-    u.ao.i += sqlite3VdbeSerialPut(&u.ao.zNewRecord[u.ao.i], (int)(u.ao.nByte-u.ao.i), u.ao.pRec,u.ao.file_format);
-  }
-  assert( u.ao.i==u.ao.nByte );
-
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  pOut->n = (int)u.ao.nByte;
-  pOut->flags = MEM_Blob | MEM_Dyn;
-  pOut->xDel = 0;
-  if( u.ao.nZero ){
-    pOut->u.nZero = u.ao.nZero;
+  i = putVarint32(zNewRecord, nHdr);
+  j = nHdr;
+  assert( pData0<=pLast );
+  pRec = pData0;
+  do{
+    serial_type = pRec->uTemp;
+    /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more
+    ** additional varints, one per column. */
+    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */
+    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
+    ** immediately follow the header. */
+    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
+  }while( (++pRec)<=pLast );
+  assert( i==nHdr );
+  assert( j==nByte );
+
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  pOut->n = (int)nByte;
+  pOut->flags = MEM_Blob;
+  if( nZero ){
+    pOut->u.nZero = nZero;
     pOut->flags |= MEM_Zero;
   }
   pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
@@ -65994,24 +79940,24 @@ case OP_MakeRecord: {
 }
 
 /* Opcode: Count P1 P2 * * *
+** Synopsis: r[P2]=count()
 **
 ** Store the number of entries (an integer value) in the table or index 
 ** opened by cursor P1 in register P2
 */
 #ifndef SQLITE_OMIT_BTREECOUNT
-case OP_Count: {         /* out2-prerelease */
-#if 0  /* local variables moved into u.ap */
+case OP_Count: {         /* out2 */
   i64 nEntry;
   BtCursor *pCrsr;
-#endif /* local variables moved into u.ap */
 
-  u.ap.pCrsr = p->apCsr[pOp->p1]->pCursor;
-  if( ALWAYS(u.ap.pCrsr) ){
-    rc = sqlite3BtreeCount(u.ap.pCrsr, &u.ap.nEntry);
-  }else{
-    u.ap.nEntry = 0;
-  }
-  pOut->u.i = u.ap.nEntry;
+  assert( p->apCsr[pOp->p1]->eCurType==CURTYPE_BTREE );
+  pCrsr = p->apCsr[pOp->p1]->uc.pCursor;
+  assert( pCrsr );
+  nEntry = 0;  /* Not needed.  Only used to silence a warning. */
+  rc = sqlite3BtreeCount(pCrsr, &nEntry);
+  if( rc ) goto abort_due_to_error;
+  pOut = out2Prerelease(p, pOp);
+  pOut->u.i = nEntry;
   break;
 }
 #endif
@@ -66023,7 +79969,6 @@ case OP_Count: {         /* out2-prerelease */
 ** existing savepoint, P1==1, or to rollback an existing savepoint P1==2.
 */
 case OP_Savepoint: {
-#if 0  /* local variables moved into u.aq */
   int p1;                         /* Value of P1 operand */
   char *zName;                    /* Name of savepoint */
   int nName;
@@ -66032,29 +79977,28 @@ case OP_Savepoint: {
   Savepoint *pTmp;
   int iSavepoint;
   int ii;
-#endif /* local variables moved into u.aq */
 
-  u.aq.p1 = pOp->p1;
-  u.aq.zName = pOp->p4.z;
+  p1 = pOp->p1;
+  zName = pOp->p4.z;
 
-  /* Assert that the u.aq.p1 parameter is valid. Also that if there is no open
-  ** transaction, then there cannot be any savepoints.
+  /* Assert that the p1 parameter is valid. Also that if there is no open
+  ** transaction, then there cannot be any savepoints. 
   */
   assert( db->pSavepoint==0 || db->autoCommit==0 );
-  assert( u.aq.p1==SAVEPOINT_BEGIN||u.aq.p1==SAVEPOINT_RELEASE||u.aq.p1==SAVEPOINT_ROLLBACK );
+  assert( p1==SAVEPOINT_BEGIN||p1==SAVEPOINT_RELEASE||p1==SAVEPOINT_ROLLBACK );
   assert( db->pSavepoint || db->isTransactionSavepoint==0 );
   assert( checkSavepointCount(db) );
+  assert( p->bIsReader );
 
-  if( u.aq.p1==SAVEPOINT_BEGIN ){
-    if( db->writeVdbeCnt>0 ){
-      /* A new savepoint cannot be created if there are active write
+  if( p1==SAVEPOINT_BEGIN ){
+    if( db->nVdbeWrite>0 ){
+      /* A new savepoint cannot be created if there are active write 
       ** statements (i.e. open read/write incremental blob handles).
       */
-      sqlite3SetString(&p->zErrMsg, db, "cannot open savepoint - "
-        "SQL statements in progress");
+      sqlite3VdbeError(p, "cannot open savepoint - SQL statements in progress");
       rc = SQLITE_BUSY;
     }else{
-      u.aq.nName = sqlite3Strlen30(u.aq.zName);
+      nName = sqlite3Strlen30(zName);
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
       /* This call is Ok even if this savepoint is actually a transaction
@@ -66068,11 +80012,11 @@ case OP_Savepoint: {
 #endif
 
       /* Create a new savepoint structure. */
-      u.aq.pNew = sqlite3DbMallocRaw(db, sizeof(Savepoint)+u.aq.nName+1);
-      if( u.aq.pNew ){
-        u.aq.pNew->zName = (char *)&u.aq.pNew[1];
-        memcpy(u.aq.pNew->zName, u.aq.zName, u.aq.nName+1);
-
+      pNew = sqlite3DbMallocRawNN(db, sizeof(Savepoint)+nName+1);
+      if( pNew ){
+        pNew->zName = (char *)&pNew[1];
+        memcpy(pNew->zName, zName, nName+1);
+    
         /* If there is no open transaction, then mark this as a special
         ** "transaction savepoint". */
         if( db->autoCommit ){
@@ -66083,52 +80027,48 @@ case OP_Savepoint: {
         }
 
         /* Link the new savepoint into the database handle's list. */
-        u.aq.pNew->pNext = db->pSavepoint;
-        db->pSavepoint = u.aq.pNew;
-        u.aq.pNew->nDeferredCons = db->nDeferredCons;
+        pNew->pNext = db->pSavepoint;
+        db->pSavepoint = pNew;
+        pNew->nDeferredCons = db->nDeferredCons;
+        pNew->nDeferredImmCons = db->nDeferredImmCons;
       }
     }
   }else{
-    u.aq.iSavepoint = 0;
+    iSavepoint = 0;
 
     /* Find the named savepoint. If there is no such savepoint, then an
     ** an error is returned to the user.  */
     for(
-      u.aq.pSavepoint = db->pSavepoint;
-      u.aq.pSavepoint && sqlite3StrICmp(u.aq.pSavepoint->zName, u.aq.zName);
-      u.aq.pSavepoint = u.aq.pSavepoint->pNext
+      pSavepoint = db->pSavepoint; 
+      pSavepoint && sqlite3StrICmp(pSavepoint->zName, zName);
+      pSavepoint = pSavepoint->pNext
     ){
-      u.aq.iSavepoint++;
+      iSavepoint++;
     }
-    if( !u.aq.pSavepoint ){
-      sqlite3SetString(&p->zErrMsg, db, "no such savepoint: %s", u.aq.zName);
+    if( !pSavepoint ){
+      sqlite3VdbeError(p, "no such savepoint: %s", zName);
       rc = SQLITE_ERROR;
-    }else if(
-        db->writeVdbeCnt>0 || (u.aq.p1==SAVEPOINT_ROLLBACK && db->activeVdbeCnt>1)
-    ){
-      /* It is not possible to release (commit) a savepoint if there are
-      ** active write statements. It is not possible to rollback a savepoint
-      ** if there are any active statements at all.
+    }else if( db->nVdbeWrite>0 && p1==SAVEPOINT_RELEASE ){
+      /* It is not possible to release (commit) a savepoint if there are 
+      ** active write statements.
       */
-      sqlite3SetString(&p->zErrMsg, db,
-        "cannot %s savepoint - SQL statements in progress",
-        (u.aq.p1==SAVEPOINT_ROLLBACK ? "rollback": "release")
-      );
+      sqlite3VdbeError(p, "cannot release savepoint - "
+                          "SQL statements in progress");
       rc = SQLITE_BUSY;
     }else{
 
       /* Determine whether or not this is a transaction savepoint. If so,
-      ** and this is a RELEASE command, then the current transaction
-      ** is committed.
+      ** and this is a RELEASE command, then the current transaction 
+      ** is committed. 
       */
-      int isTransaction = u.aq.pSavepoint->pNext==0 && db->isTransactionSavepoint;
-      if( isTransaction && u.aq.p1==SAVEPOINT_RELEASE ){
+      int isTransaction = pSavepoint->pNext==0 && db->isTransactionSavepoint;
+      if( isTransaction && p1==SAVEPOINT_RELEASE ){
         if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
           goto vdbe_return;
         }
         db->autoCommit = 1;
         if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
-          p->pc = pc;
+          p->pc = (int)(pOp - aOp);
           db->autoCommit = 0;
           p->rc = rc = SQLITE_BUSY;
           goto vdbe_return;
@@ -66136,50 +80076,64 @@ case OP_Savepoint: {
         db->isTransactionSavepoint = 0;
         rc = p->rc;
       }else{
-        u.aq.iSavepoint = db->nSavepoint - u.aq.iSavepoint - 1;
-        for(u.aq.ii=0; u.aq.ii<db->nDb; u.aq.ii++){
-          rc = sqlite3BtreeSavepoint(db->aDb[u.aq.ii].pBt, u.aq.p1, u.aq.iSavepoint);
+        int isSchemaChange;
+        iSavepoint = db->nSavepoint - iSavepoint - 1;
+        if( p1==SAVEPOINT_ROLLBACK ){
+          isSchemaChange = (db->flags & SQLITE_InternChanges)!=0;
+          for(ii=0; ii<db->nDb; ii++){
+            rc = sqlite3BtreeTripAllCursors(db->aDb[ii].pBt,
+                                       SQLITE_ABORT_ROLLBACK,
+                                       isSchemaChange==0);
+            if( rc!=SQLITE_OK ) goto abort_due_to_error;
+          }
+        }else{
+          isSchemaChange = 0;
+        }
+        for(ii=0; ii<db->nDb; ii++){
+          rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);
           if( rc!=SQLITE_OK ){
             goto abort_due_to_error;
           }
         }
-        if( u.aq.p1==SAVEPOINT_ROLLBACK && (db->flags&SQLITE_InternChanges)!=0 ){
+        if( isSchemaChange ){
           sqlite3ExpirePreparedStatements(db);
-          sqlite3ResetInternalSchema(db, -1);
+          sqlite3ResetAllSchemasOfConnection(db);
           db->flags = (db->flags | SQLITE_InternChanges);
         }
       }
-
-      /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all
+  
+      /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all 
       ** savepoints nested inside of the savepoint being operated on. */
-      while( db->pSavepoint!=u.aq.pSavepoint ){
-        u.aq.pTmp = db->pSavepoint;
-        db->pSavepoint = u.aq.pTmp->pNext;
-        sqlite3DbFree(db, u.aq.pTmp);
+      while( db->pSavepoint!=pSavepoint ){
+        pTmp = db->pSavepoint;
+        db->pSavepoint = pTmp->pNext;
+        sqlite3DbFree(db, pTmp);
         db->nSavepoint--;
       }
 
-      /* If it is a RELEASE, then destroy the savepoint being operated on
-      ** too. If it is a ROLLBACK TO, then set the number of deferred
+      /* If it is a RELEASE, then destroy the savepoint being operated on 
+      ** too. If it is a ROLLBACK TO, then set the number of deferred 
       ** constraint violations present in the database to the value stored
       ** when the savepoint was created.  */
-      if( u.aq.p1==SAVEPOINT_RELEASE ){
-        assert( u.aq.pSavepoint==db->pSavepoint );
-        db->pSavepoint = u.aq.pSavepoint->pNext;
-        sqlite3DbFree(db, u.aq.pSavepoint);
+      if( p1==SAVEPOINT_RELEASE ){
+        assert( pSavepoint==db->pSavepoint );
+        db->pSavepoint = pSavepoint->pNext;
+        sqlite3DbFree(db, pSavepoint);
         if( !isTransaction ){
           db->nSavepoint--;
         }
       }else{
-        db->nDeferredCons = u.aq.pSavepoint->nDeferredCons;
+        db->nDeferredCons = pSavepoint->nDeferredCons;
+        db->nDeferredImmCons = pSavepoint->nDeferredImmCons;
       }
 
-      if( !isTransaction ){
-        rc = sqlite3VtabSavepoint(db, u.aq.p1, u.aq.iSavepoint);
+      if( !isTransaction || p1==SAVEPOINT_ROLLBACK ){
+        rc = sqlite3VtabSavepoint(db, p1, iSavepoint);
         if( rc!=SQLITE_OK ) goto abort_due_to_error;
       }
     }
   }
+  if( rc ) goto abort_due_to_error;
 
   break;
 }
@@ -66194,49 +80148,39 @@ case OP_Savepoint: {
 ** This instruction causes the VM to halt.
 */
 case OP_AutoCommit: {
-#if 0  /* local variables moved into u.ar */
   int desiredAutoCommit;
   int iRollback;
-  int turnOnAC;
-#endif /* local variables moved into u.ar */
-
-  u.ar.desiredAutoCommit = pOp->p1;
-  u.ar.iRollback = pOp->p2;
-  u.ar.turnOnAC = u.ar.desiredAutoCommit && !db->autoCommit;
-  assert( u.ar.desiredAutoCommit==1 || u.ar.desiredAutoCommit==0 );
-  assert( u.ar.desiredAutoCommit==1 || u.ar.iRollback==0 );
-  assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */
-
-  if( u.ar.turnOnAC && u.ar.iRollback && db->activeVdbeCnt>1 ){
-    /* If this instruction implements a ROLLBACK and other VMs are
-    ** still running, and a transaction is active, return an error indicating
-    ** that the other VMs must complete first.
-    */
-    sqlite3SetString(&p->zErrMsg, db, "cannot rollback transaction - "
-        "SQL statements in progress");
-    rc = SQLITE_BUSY;
-  }else if( u.ar.turnOnAC && !u.ar.iRollback && db->writeVdbeCnt>0 ){
-    /* If this instruction implements a COMMIT and other VMs are writing
-    ** return an error indicating that the other VMs must complete first.
-    */
-    sqlite3SetString(&p->zErrMsg, db, "cannot commit transaction - "
-        "SQL statements in progress");
-    rc = SQLITE_BUSY;
-  }else if( u.ar.desiredAutoCommit!=db->autoCommit ){
-    if( u.ar.iRollback ){
-      assert( u.ar.desiredAutoCommit==1 );
-      sqlite3RollbackAll(db);
+
+  desiredAutoCommit = pOp->p1;
+  iRollback = pOp->p2;
+  assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
+  assert( desiredAutoCommit==1 || iRollback==0 );
+  assert( db->nVdbeActive>0 );  /* At least this one VM is active */
+  assert( p->bIsReader );
+
+  if( desiredAutoCommit!=db->autoCommit ){
+    if( iRollback ){
+      assert( desiredAutoCommit==1 );
+      sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
       db->autoCommit = 1;
+    }else if( desiredAutoCommit && db->nVdbeWrite>0 ){
+      /* If this instruction implements a COMMIT and other VMs are writing
+      ** return an error indicating that the other VMs must complete first. 
+      */
+      sqlite3VdbeError(p, "cannot commit transaction - "
+                          "SQL statements in progress");
+      rc = SQLITE_BUSY;
+      goto abort_due_to_error;
     }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){
       goto vdbe_return;
     }else{
-      db->autoCommit = (u8)u.ar.desiredAutoCommit;
-      if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
-        p->pc = pc;
-        db->autoCommit = (u8)(1-u.ar.desiredAutoCommit);
-        p->rc = rc = SQLITE_BUSY;
-        goto vdbe_return;
-      }
+      db->autoCommit = (u8)desiredAutoCommit;
+    }
+    if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
+      p->pc = (int)(pOp - aOp);
+      db->autoCommit = (u8)(1-desiredAutoCommit);
+      p->rc = rc = SQLITE_BUSY;
+      goto vdbe_return;
     }
     assert( db->nStatement==0 );
     sqlite3CloseSavepoints(db);
@@ -66247,88 +80191,136 @@ case OP_AutoCommit: {
     }
     goto vdbe_return;
   }else{
-    sqlite3SetString(&p->zErrMsg, db,
-        (!u.ar.desiredAutoCommit)?"cannot start a transaction within a transaction":(
-        (u.ar.iRollback)?"cannot rollback - no transaction is active":
+    sqlite3VdbeError(p,
+        (!desiredAutoCommit)?"cannot start a transaction within a transaction":(
+        (iRollback)?"cannot rollback - no transaction is active":
                    "cannot commit - no transaction is active"));
-
+         
     rc = SQLITE_ERROR;
+    goto abort_due_to_error;
   }
   break;
 }
 
-/* Opcode: Transaction P1 P2 * * *
+/* Opcode: Transaction P1 P2 P3 P4 P5
 **
-** Begin a transaction.  The transaction ends when a Commit or Rollback
-** opcode is encountered.  Depending on the ON CONFLICT setting, the
-** transaction might also be rolled back if an error is encountered.
+** Begin a transaction on database P1 if a transaction is not already
+** active.
+** If P2 is non-zero, then a write-transaction is started, or if a 
+** read-transaction is already active, it is upgraded to a write-transaction.
+** If P2 is zero, then a read-transaction is started.
 **
 ** P1 is the index of the database file on which the transaction is
 ** started.  Index 0 is the main database file and index 1 is the
 ** file used for temporary tables.  Indices of 2 or more are used for
 ** attached databases.
 **
-** If P2 is non-zero, then a write-transaction is started.  A RESERVED lock is
-** obtained on the database file when a write-transaction is started.  No
-** other process can start another write transaction while this transaction is
-** underway.  Starting a write transaction also creates a rollback journal. A
-** write transaction must be started before any changes can be made to the
-** database.  If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
-** on the file.
-**
 ** If a write-transaction is started and the Vdbe.usesStmtJournal flag is
 ** true (this flag is set if the Vdbe may modify more than one row and may
 ** throw an ABORT exception), a statement transaction may also be opened.
 ** More specifically, a statement transaction is opened iff the database
 ** connection is currently not in autocommit mode, or if there are other
-** active statements. A statement transaction allows the affects of this
+** active statements. A statement transaction allows the changes made by this
 ** VDBE to be rolled back after an error without having to roll back the
 ** entire transaction. If no error is encountered, the statement transaction
 ** will automatically commit when the VDBE halts.
 **
-** If P2 is zero, then a read-lock is obtained on the database file.
+** If P5!=0 then this opcode also checks the schema cookie against P3
+** and the schema generation counter against P4.
+** The cookie changes its value whenever the database schema changes.
+** This operation is used to detect when that the cookie has changed
+** and that the current process needs to reread the schema.  If the schema
+** cookie in P3 differs from the schema cookie in the database header or
+** if the schema generation counter in P4 differs from the current
+** generation counter, then an SQLITE_SCHEMA error is raised and execution
+** halts.  The sqlite3_step() wrapper function might then reprepare the
+** statement and rerun it from the beginning.
 */
 case OP_Transaction: {
-#if 0  /* local variables moved into u.as */
   Btree *pBt;
-#endif /* local variables moved into u.as */
+  int iMeta;
+  int iGen;
 
+  assert( p->bIsReader );
+  assert( p->readOnly==0 || pOp->p2==0 );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
-  u.as.pBt = db->aDb[pOp->p1].pBt;
+  assert( DbMaskTest(p->btreeMask, pOp->p1) );
+  if( pOp->p2 && (db->flags & SQLITE_QueryOnly)!=0 ){
+    rc = SQLITE_READONLY;
+    goto abort_due_to_error;
+  }
+  pBt = db->aDb[pOp->p1].pBt;
 
-  if( u.as.pBt ){
-    rc = sqlite3BtreeBeginTrans(u.as.pBt, pOp->p2);
-    if( rc==SQLITE_BUSY ){
-      p->pc = pc;
-      p->rc = rc = SQLITE_BUSY;
+  if( pBt ){
+    rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
+    testcase( rc==SQLITE_BUSY_SNAPSHOT );
+    testcase( rc==SQLITE_BUSY_RECOVERY );
+    if( (rc&0xff)==SQLITE_BUSY ){
+      p->pc = (int)(pOp - aOp);
+      p->rc = rc;
       goto vdbe_return;
     }
     if( rc!=SQLITE_OK ){
       goto abort_due_to_error;
     }
 
-    if( pOp->p2 && p->usesStmtJournal
-     && (db->autoCommit==0 || db->activeVdbeCnt>1)
+    if( pOp->p2 && p->usesStmtJournal 
+     && (db->autoCommit==0 || db->nVdbeRead>1) 
     ){
-      assert( sqlite3BtreeIsInTrans(u.as.pBt) );
+      assert( sqlite3BtreeIsInTrans(pBt) );
       if( p->iStatement==0 ){
         assert( db->nStatement>=0 && db->nSavepoint>=0 );
-        db->nStatement++;
+        db->nStatement++; 
         p->iStatement = db->nSavepoint + db->nStatement;
       }
 
       rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, p->iStatement-1);
       if( rc==SQLITE_OK ){
-        rc = sqlite3BtreeBeginStmt(u.as.pBt, p->iStatement);
+        rc = sqlite3BtreeBeginStmt(pBt, p->iStatement);
       }
 
       /* Store the current value of the database handles deferred constraint
       ** counter. If the statement transaction needs to be rolled back,
       ** the value of this counter needs to be restored too.  */
       p->nStmtDefCons = db->nDeferredCons;
+      p->nStmtDefImmCons = db->nDeferredImmCons;
+    }
+
+    /* Gather the schema version number for checking:
+    ** IMPLEMENTATION-OF: R-32195-19465 The schema version is used by SQLite
+    ** each time a query is executed to ensure that the internal cache of the
+    ** schema used when compiling the SQL query matches the schema of the
+    ** database against which the compiled query is actually executed.
+    */
+    sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
+    iGen = db->aDb[pOp->p1].pSchema->iGeneration;
+  }else{
+    iGen = iMeta = 0;
+  }
+  assert( pOp->p5==0 || pOp->p4type==P4_INT32 );
+  if( pOp->p5 && (iMeta!=pOp->p3 || iGen!=pOp->p4.i) ){
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
+    /* If the schema-cookie from the database file matches the cookie 
+    ** stored with the in-memory representation of the schema, do
+    ** not reload the schema from the database file.
+    **
+    ** If virtual-tables are in use, this is not just an optimization.
+    ** Often, v-tables store their data in other SQLite tables, which
+    ** are queried from within xNext() and other v-table methods using
+    ** prepared queries. If such a query is out-of-date, we do not want to
+    ** discard the database schema, as the user code implementing the
+    ** v-table would have to be ready for the sqlite3_vtab structure itself
+    ** to be invalidated whenever sqlite3_step() is called from within 
+    ** a v-table method.
+    */
+    if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
+      sqlite3ResetOneSchema(db, pOp->p1);
     }
+    p->expired = 1;
+    rc = SQLITE_SCHEMA;
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
@@ -66344,56 +80336,53 @@ case OP_Transaction: {
 ** must be started or there must be an open cursor) before
 ** executing this instruction.
 */
-case OP_ReadCookie: {               /* out2-prerelease */
-#if 0  /* local variables moved into u.at */
+case OP_ReadCookie: {               /* out2 */
   int iMeta;
   int iDb;
   int iCookie;
-#endif /* local variables moved into u.at */
 
-  u.at.iDb = pOp->p1;
-  u.at.iCookie = pOp->p3;
+  assert( p->bIsReader );
+  iDb = pOp->p1;
+  iCookie = pOp->p3;
   assert( pOp->p3<SQLITE_N_BTREE_META );
-  assert( u.at.iDb>=0 && u.at.iDb<db->nDb );
-  assert( db->aDb[u.at.iDb].pBt!=0 );
-  assert( (p->btreeMask & (((yDbMask)1)<<u.at.iDb))!=0 );
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pBt!=0 );
+  assert( DbMaskTest(p->btreeMask, iDb) );
 
-  sqlite3BtreeGetMeta(db->aDb[u.at.iDb].pBt, u.at.iCookie, (u32 *)&u.at.iMeta);
-  pOut->u.i = u.at.iMeta;
+  sqlite3BtreeGetMeta(db->aDb[iDb].pBt, iCookie, (u32 *)&iMeta);
+  pOut = out2Prerelease(p, pOp);
+  pOut->u.i = iMeta;
   break;
 }
 
 /* Opcode: SetCookie P1 P2 P3 * *
 **
-** Write the content of register P3 (interpreted as an integer)
-** into cookie number P2 of database P1.  P2==1 is the schema version.  
-** P2==2 is the database format. P2==3 is the recommended pager cache 
+** Write the integer value P3 into cookie number P2 of database P1.
+** P2==1 is the schema version.  P2==2 is the database format.
+** P2==3 is the recommended pager cache 
 ** size, and so forth.  P1==0 is the main database file and P1==1 is the 
 ** database file used to store temporary tables.
 **
 ** A transaction must be started before executing this opcode.
 */
-case OP_SetCookie: {       /* in3 */
-#if 0  /* local variables moved into u.au */
+case OP_SetCookie: {
   Db *pDb;
-#endif /* local variables moved into u.au */
   assert( pOp->p2<SQLITE_N_BTREE_META );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
-  u.au.pDb = &db->aDb[pOp->p1];
-  assert( u.au.pDb->pBt!=0 );
+  assert( DbMaskTest(p->btreeMask, pOp->p1) );
+  assert( p->readOnly==0 );
+  pDb = &db->aDb[pOp->p1];
+  assert( pDb->pBt!=0 );
   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
-  pIn3 = &aMem[pOp->p3];
-  sqlite3VdbeMemIntegerify(pIn3);
   /* See note about index shifting on OP_ReadCookie */
-  rc = sqlite3BtreeUpdateMeta(u.au.pDb->pBt, pOp->p2, (int)pIn3->u.i);
+  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, pOp->p3);
   if( pOp->p2==BTREE_SCHEMA_VERSION ){
     /* When the schema cookie changes, record the new cookie internally */
-    u.au.pDb->pSchema->schema_cookie = (int)pIn3->u.i;
+    pDb->pSchema->schema_cookie = pOp->p3;
     db->flags |= SQLITE_InternChanges;
   }else if( pOp->p2==BTREE_FILE_FORMAT ){
     /* Record changes in the file format */
-    u.au.pDb->pSchema->file_format = (u8)pIn3->u.i;
+    pDb->pSchema->file_format = pOp->p3;
   }
   if( pOp->p1==1 ){
     /* Invalidate all prepared statements whenever the TEMP database
@@ -66401,71 +80390,12 @@ case OP_SetCookie: {       /* in3 */
     sqlite3ExpirePreparedStatements(db);
     p->expired = 0;
   }
-  break;
-}
-
-/* Opcode: VerifyCookie P1 P2 P3 * *
-**
-** Check the value of global database parameter number 0 (the
-** schema version) and make sure it is equal to P2 and that the
-** generation counter on the local schema parse equals P3.
-**
-** P1 is the database number which is 0 for the main database file
-** and 1 for the file holding temporary tables and some higher number
-** for auxiliary databases.
-**
-** The cookie changes its value whenever the database schema changes.
-** This operation is used to detect when that the cookie has changed
-** and that the current process needs to reread the schema.
-**
-** Either a transaction needs to have been started or an OP_Open needs
-** to be executed (to establish a read lock) before this opcode is
-** invoked.
-*/
-case OP_VerifyCookie: {
-#if 0  /* local variables moved into u.av */
-  int iMeta;
-  int iGen;
-  Btree *pBt;
-#endif /* local variables moved into u.av */
-
-  assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
-  assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
-  u.av.pBt = db->aDb[pOp->p1].pBt;
-  if( u.av.pBt ){
-    sqlite3BtreeGetMeta(u.av.pBt, BTREE_SCHEMA_VERSION, (u32 *)&u.av.iMeta);
-    u.av.iGen = db->aDb[pOp->p1].pSchema->iGeneration;
-  }else{
-    u.av.iGen = u.av.iMeta = 0;
-  }
-  if( u.av.iMeta!=pOp->p2 || u.av.iGen!=pOp->p3 ){
-    sqlite3DbFree(db, p->zErrMsg);
-    p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
-    /* If the schema-cookie from the database file matches the cookie
-    ** stored with the in-memory representation of the schema, do
-    ** not reload the schema from the database file.
-    **
-    ** If virtual-tables are in use, this is not just an optimization.
-    ** Often, v-tables store their data in other SQLite tables, which
-    ** are queried from within xNext() and other v-table methods using
-    ** prepared queries. If such a query is out-of-date, we do not want to
-    ** discard the database schema, as the user code implementing the
-    ** v-table would have to be ready for the sqlite3_vtab structure itself
-    ** to be invalidated whenever sqlite3_step() is called from within
-    ** a v-table method.
-    */
-    if( db->aDb[pOp->p1].pSchema->schema_cookie!=u.av.iMeta ){
-      sqlite3ResetInternalSchema(db, pOp->p1);
-    }
-
-    p->expired = 1;
-    rc = SQLITE_SCHEMA;
-  }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
 /* Opcode: OpenRead P1 P2 P3 P4 P5
+** Synopsis: root=P2 iDb=P3
 **
 ** Open a read-only cursor for the database table whose root page is
 ** P2 in a database file.  The database file is determined by P3. 
@@ -66493,9 +80423,24 @@ case OP_VerifyCookie: {
 ** sequence of the index being opened. Otherwise, if P4 is an integer 
 ** value, it is set to the number of columns in the table.
 **
-** See also OpenWrite.
+** See also: OpenWrite, ReopenIdx
+*/
+/* Opcode: ReopenIdx P1 P2 P3 P4 P5
+** Synopsis: root=P2 iDb=P3
+**
+** The ReopenIdx opcode works exactly like ReadOpen except that it first
+** checks to see if the cursor on P1 is already open with a root page
+** number of P2 and if it is this opcode becomes a no-op.  In other words,
+** if the cursor is already open, do not reopen it.
+**
+** The ReopenIdx opcode may only be used with P5==0 and with P4 being
+** a P4_KEYINFO object.  Furthermore, the P3 value must be the same as
+** every other ReopenIdx or OpenRead for the same cursor number.
+**
+** See the OpenRead opcode documentation for additional information.
 */
 /* Opcode: OpenWrite P1 P2 P3 P4 P5
+** Synopsis: root=P2 iDb=P3
 **
 ** Open a read/write cursor named P1 on the table or index whose root
 ** page is P2.  Or if P5!=0 use the content of register P2 to find the
@@ -66514,9 +80459,7 @@ case OP_VerifyCookie: {
 **
 ** See also OpenRead.
 */
-case OP_OpenRead:
-case OP_OpenWrite: {
-#if 0  /* local variables moved into u.aw */
+case OP_ReopenIdx: {
   int nField;
   KeyInfo *pKeyInfo;
   int p2;
@@ -66525,77 +80468,104 @@ case OP_OpenWrite: {
   Btree *pX;
   VdbeCursor *pCur;
   Db *pDb;
-#endif /* local variables moved into u.aw */
+
+  assert( pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
+  assert( pOp->p4type==P4_KEYINFO );
+  pCur = p->apCsr[pOp->p1];
+  if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){
+    assert( pCur->iDb==pOp->p3 );      /* Guaranteed by the code generator */
+    goto open_cursor_set_hints;
+  }
+  /* If the cursor is not currently open or is open on a different
+  ** index, then fall through into OP_OpenRead to force a reopen */
+case OP_OpenRead:
+case OP_OpenWrite:
+
+  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
+  assert( p->bIsReader );
+  assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx
+          || p->readOnly==0 );
 
   if( p->expired ){
-    rc = SQLITE_ABORT;
-    break;
+    rc = SQLITE_ABORT_ROLLBACK;
+    goto abort_due_to_error;
   }
 
-  u.aw.nField = 0;
-  u.aw.pKeyInfo = 0;
-  u.aw.p2 = pOp->p2;
-  u.aw.iDb = pOp->p3;
-  assert( u.aw.iDb>=0 && u.aw.iDb<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<u.aw.iDb))!=0 );
-  u.aw.pDb = &db->aDb[u.aw.iDb];
-  u.aw.pX = u.aw.pDb->pBt;
-  assert( u.aw.pX!=0 );
+  nField = 0;
+  pKeyInfo = 0;
+  p2 = pOp->p2;
+  iDb = pOp->p3;
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( DbMaskTest(p->btreeMask, iDb) );
+  pDb = &db->aDb[iDb];
+  pX = pDb->pBt;
+  assert( pX!=0 );
   if( pOp->opcode==OP_OpenWrite ){
-    u.aw.wrFlag = 1;
-    assert( sqlite3SchemaMutexHeld(db, u.aw.iDb, 0) );
-    if( u.aw.pDb->pSchema->file_format < p->minWriteFileFormat ){
-      p->minWriteFileFormat = u.aw.pDb->pSchema->file_format;
+    assert( OPFLAG_FORDELETE==BTREE_FORDELETE );
+    wrFlag = BTREE_WRCSR | (pOp->p5 & OPFLAG_FORDELETE);
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( pDb->pSchema->file_format < p->minWriteFileFormat ){
+      p->minWriteFileFormat = pDb->pSchema->file_format;
     }
   }else{
-    u.aw.wrFlag = 0;
+    wrFlag = 0;
   }
-  if( pOp->p5 ){
-    assert( u.aw.p2>0 );
-    assert( u.aw.p2<=p->nMem );
-    pIn2 = &aMem[u.aw.p2];
+  if( pOp->p5 & OPFLAG_P2ISREG ){
+    assert( p2>0 );
+    assert( p2<=(p->nMem+1 - p->nCursor) );
+    pIn2 = &aMem[p2];
     assert( memIsValid(pIn2) );
     assert( (pIn2->flags & MEM_Int)!=0 );
     sqlite3VdbeMemIntegerify(pIn2);
-    u.aw.p2 = (int)pIn2->u.i;
-    /* The u.aw.p2 value always comes from a prior OP_CreateTable opcode and
-    ** that opcode will always set the u.aw.p2 value to 2 or more or else fail.
+    p2 = (int)pIn2->u.i;
+    /* The p2 value always comes from a prior OP_CreateTable opcode and
+    ** that opcode will always set the p2 value to 2 or more or else fail.
     ** If there were a failure, the prepared statement would have halted
     ** before reaching this instruction. */
-    if( NEVER(u.aw.p2<2) ) {
-      rc = SQLITE_CORRUPT_BKPT;
-      goto abort_due_to_error;
-    }
+    assert( p2>=2 );
   }
   if( pOp->p4type==P4_KEYINFO ){
-    u.aw.pKeyInfo = pOp->p4.pKeyInfo;
-    u.aw.pKeyInfo->enc = ENC(p->db);
-    u.aw.nField = u.aw.pKeyInfo->nField+1;
+    pKeyInfo = pOp->p4.pKeyInfo;
+    assert( pKeyInfo->enc==ENC(db) );
+    assert( pKeyInfo->db==db );
+    nField = pKeyInfo->nField+pKeyInfo->nXField;
   }else if( pOp->p4type==P4_INT32 ){
-    u.aw.nField = pOp->p4.i;
+    nField = pOp->p4.i;
   }
   assert( pOp->p1>=0 );
-  u.aw.pCur = allocateCursor(p, pOp->p1, u.aw.nField, u.aw.iDb, 1);
-  if( u.aw.pCur==0 ) goto no_mem;
-  u.aw.pCur->nullRow = 1;
-  u.aw.pCur->isOrdered = 1;
-  rc = sqlite3BtreeCursor(u.aw.pX, u.aw.p2, u.aw.wrFlag, u.aw.pKeyInfo, u.aw.pCur->pCursor);
-  u.aw.pCur->pKeyInfo = u.aw.pKeyInfo;
-
-  /* Since it performs no memory allocation or IO, the only value that
-  ** sqlite3BtreeCursor() may return is SQLITE_OK. */
-  assert( rc==SQLITE_OK );
-
-  /* Set the VdbeCursor.isTable and isIndex variables. Previous versions of
+  assert( nField>=0 );
+  testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
+  pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);
+  if( pCur==0 ) goto no_mem;
+  pCur->nullRow = 1;
+  pCur->isOrdered = 1;
+  pCur->pgnoRoot = p2;
+#ifdef SQLITE_DEBUG
+  pCur->wrFlag = wrFlag;
+#endif
+  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->uc.pCursor);
+  pCur->pKeyInfo = pKeyInfo;
+  /* Set the VdbeCursor.isTable variable. Previous versions of
   ** SQLite used to check if the root-page flags were sane at this point
   ** and report database corruption if they were not, but this check has
-  ** since moved into the btree layer.  */
-  u.aw.pCur->isTable = pOp->p4type!=P4_KEYINFO;
-  u.aw.pCur->isIndex = !u.aw.pCur->isTable;
+  ** since moved into the btree layer.  */  
+  pCur->isTable = pOp->p4type!=P4_KEYINFO;
+
+open_cursor_set_hints:
+  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
+  assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );
+  testcase( pOp->p5 & OPFLAG_BULKCSR );
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+  testcase( pOp->p2 & OPFLAG_SEEKEQ );
+#endif
+  sqlite3BtreeCursorHintFlags(pCur->uc.pCursor,
+                               (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
 /* Opcode: OpenEphemeral P1 P2 * P4 P5
+** Synopsis: nColumn=P2
 **
 ** Open a new cursor P1 to a transient table.
 ** The cursor is always opened read/write even if 
@@ -66607,18 +80577,13 @@ case OP_OpenWrite: {
 ** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure
 ** that defines the format of keys in the index.
 **
-** This opcode was once called OpenTemp.  But that created
-** confusion because the term "temp table", might refer either
-** to a TEMP table at the SQL level, or to a table opened by
-** this opcode.  Then this opcode was call OpenVirtual.  But
-** that created confusion with the whole virtual-table idea.
-**
 ** The P5 parameter can be a mask of the BTREE_* flags defined
 ** in btree.h.  These flags control aspects of the operation of
 ** the btree.  The BTREE_OMIT_JOURNAL and BTREE_SINGLE flags are
 ** added automatically.
 */
 /* Opcode: OpenAutoindex P1 P2 * P4 *
+** Synopsis: nColumn=P2
 **
 ** This opcode works the same as OP_OpenEphemeral.  It has a
 ** different name to distinguish its use.  Tables created using
@@ -66627,24 +80592,25 @@ case OP_OpenWrite: {
 */
 case OP_OpenAutoindex: 
 case OP_OpenEphemeral: {
-#if 0  /* local variables moved into u.ax */
   VdbeCursor *pCx;
-#endif /* local variables moved into u.ax */
-  static const int vfsFlags =
+  KeyInfo *pKeyInfo;
+
+  static const int vfsFlags = 
       SQLITE_OPEN_READWRITE |
       SQLITE_OPEN_CREATE |
       SQLITE_OPEN_EXCLUSIVE |
       SQLITE_OPEN_DELETEONCLOSE |
       SQLITE_OPEN_TRANSIENT_DB;
-
   assert( pOp->p1>=0 );
-  u.ax.pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
-  if( u.ax.pCx==0 ) goto no_mem;
-  u.ax.pCx->nullRow = 1;
-  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &u.ax.pCx->pBt,
+  assert( pOp->p2>=0 );
+  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_BTREE);
+  if( pCx==0 ) goto no_mem;
+  pCx->nullRow = 1;
+  pCx->isEphemeral = 1;
+  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
                         BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
   if( rc==SQLITE_OK ){
-    rc = sqlite3BtreeBeginTrans(u.ax.pCx->pBt, 1);
+    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
   }
   if( rc==SQLITE_OK ){
     /* If a transient index is required, create it by calling
@@ -66652,56 +80618,78 @@ case OP_OpenEphemeral: {
     ** opening it. If a transient table is required, just use the
     ** automatically created table with root-page 1 (an BLOB_INTKEY table).
     */
-    if( pOp->p4.pKeyInfo ){
+    if( (pKeyInfo = pOp->p4.pKeyInfo)!=0 ){
       int pgno;
       assert( pOp->p4type==P4_KEYINFO );
-      rc = sqlite3BtreeCreateTable(u.ax.pCx->pBt, &pgno, BTREE_BLOBKEY | pOp->p5);
+      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_BLOBKEY | pOp->p5); 
       if( rc==SQLITE_OK ){
         assert( pgno==MASTER_ROOT+1 );
-        rc = sqlite3BtreeCursor(u.ax.pCx->pBt, pgno, 1,
-                                (KeyInfo*)pOp->p4.z, u.ax.pCx->pCursor);
-        u.ax.pCx->pKeyInfo = pOp->p4.pKeyInfo;
-        u.ax.pCx->pKeyInfo->enc = ENC(p->db);
+        assert( pKeyInfo->db==db );
+        assert( pKeyInfo->enc==ENC(db) );
+        pCx->pKeyInfo = pKeyInfo;
+        rc = sqlite3BtreeCursor(pCx->pBt, pgno, BTREE_WRCSR,
+                                pKeyInfo, pCx->uc.pCursor);
       }
-      u.ax.pCx->isTable = 0;
+      pCx->isTable = 0;
     }else{
-      rc = sqlite3BtreeCursor(u.ax.pCx->pBt, MASTER_ROOT, 1, 0, u.ax.pCx->pCursor);
-      u.ax.pCx->isTable = 1;
+      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, BTREE_WRCSR,
+                              0, pCx->uc.pCursor);
+      pCx->isTable = 1;
     }
   }
-  u.ax.pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
-  u.ax.pCx->isIndex = !u.ax.pCx->isTable;
+  if( rc ) goto abort_due_to_error;
+  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
   break;
 }
 
-/* Opcode: OpenSorter P1 P2 * P4 *
+/* Opcode: SorterOpen P1 P2 P3 P4 *
 **
 ** This opcode works like OP_OpenEphemeral except that it opens
 ** a transient index that is specifically designed to sort large
 ** tables using an external merge-sort algorithm.
+**
+** If argument P3 is non-zero, then it indicates that the sorter may
+** assume that a stable sort considering the first P3 fields of each
+** key is sufficient to produce the required results.
 */
 case OP_SorterOpen: {
-#if 0  /* local variables moved into u.ay */
   VdbeCursor *pCx;
-#endif /* local variables moved into u.ay */
-#ifndef SQLITE_OMIT_MERGE_SORT
-  u.ay.pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
-  if( u.ay.pCx==0 ) goto no_mem;
-  u.ay.pCx->pKeyInfo = pOp->p4.pKeyInfo;
-  u.ay.pCx->pKeyInfo->enc = ENC(p->db);
-  u.ay.pCx->isSorter = 1;
-  rc = sqlite3VdbeSorterInit(db, u.ay.pCx);
-#else
-  pOp->opcode = OP_OpenEphemeral;
-  pc--;
-#endif
+
+  assert( pOp->p1>=0 );
+  assert( pOp->p2>=0 );
+  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_SORTER);
+  if( pCx==0 ) goto no_mem;
+  pCx->pKeyInfo = pOp->p4.pKeyInfo;
+  assert( pCx->pKeyInfo->db==db );
+  assert( pCx->pKeyInfo->enc==ENC(db) );
+  rc = sqlite3VdbeSorterInit(db, pOp->p3, pCx);
+  if( rc ) goto abort_due_to_error;
+  break;
+}
+
+/* Opcode: SequenceTest P1 P2 * * *
+** Synopsis: if( cursor[P1].ctr++ ) pc = P2
+**
+** P1 is a sorter cursor. If the sequence counter is currently zero, jump
+** to P2. Regardless of whether or not the jump is taken, increment the
+** the sequence value.
+*/
+case OP_SequenceTest: {
+  VdbeCursor *pC;
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  pC = p->apCsr[pOp->p1];
+  assert( isSorter(pC) );
+  if( (pC->seqCount++)==0 ){
+    goto jump_to_p2;
+  }
   break;
 }
 
 /* Opcode: OpenPseudo P1 P2 P3 * *
+** Synopsis: P3 columns in r[P2]
 **
 ** Open a new cursor that points to a fake table that contains a single
-** row of data.  The content of that one row in the content of memory
+** row of data.  The content of that one row is the content of memory
 ** register P2.  In other words, cursor P1 becomes an alias for the 
 ** MEM_Blob content contained in register P2.
 **
@@ -66714,17 +80702,16 @@ case OP_SorterOpen: {
 ** the pseudo-table.
 */
 case OP_OpenPseudo: {
-#if 0  /* local variables moved into u.az */
   VdbeCursor *pCx;
-#endif /* local variables moved into u.az */
 
   assert( pOp->p1>=0 );
-  u.az.pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
-  if( u.az.pCx==0 ) goto no_mem;
-  u.az.pCx->nullRow = 1;
-  u.az.pCx->pseudoTableReg = pOp->p2;
-  u.az.pCx->isTable = 1;
-  u.az.pCx->isIndex = 0;
+  assert( pOp->p3>=0 );
+  pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, CURTYPE_PSEUDO);
+  if( pCx==0 ) goto no_mem;
+  pCx->nullRow = 1;
+  pCx->uc.pseudoTableReg = pOp->p2;
+  pCx->isTable = 1;
+  assert( pOp->p5==0 );
   break;
 }
 
@@ -66740,7 +80727,28 @@ case OP_Close: {
   break;
 }
 
-/* Opcode: SeekGe P1 P2 P3 P4 *
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+/* Opcode: ColumnsUsed P1 * * P4 *
+**
+** This opcode (which only exists if SQLite was compiled with
+** SQLITE_ENABLE_COLUMN_USED_MASK) identifies which columns of the
+** table or index for cursor P1 are used.  P4 is a 64-bit integer
+** (P4_INT64) in which the first 63 bits are one for each of the
+** first 63 columns of the table or index that are actually used
+** by the cursor.  The high-order bit is set if any column after
+** the 64th is used.
+*/
+case OP_ColumnsUsed: {
+  VdbeCursor *pC;
+  pC = p->apCsr[pOp->p1];
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pC->maskUsed = *(u64*)pOp->p4.pI64;
+  break;
+}
+#endif
+
+/* Opcode: SeekGE P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
 **
 ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
 ** use the value in register P3 as the key.  If cursor P1 refers 
@@ -66751,9 +80759,21 @@ case OP_Close: {
 ** is greater than or equal to the key value. If there are no records 
 ** greater than or equal to the key and P2 is not zero, then jump to P2.
 **
-** See also: Found, NotFound, Distinct, SeekLt, SeekGt, SeekLe
+** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
+** opcode will always land on a record that equally equals the key, or
+** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this
+** opcode must be followed by an IdxLE opcode with the same arguments.
+** The IdxLE opcode will be skipped if this opcode succeeds, but the
+** IdxLE opcode will be used on subsequent loop iterations.
+**
+** This opcode leaves the cursor configured to move in forward order,
+** from the beginning toward the end.  In other words, the cursor is
+** configured to use Next, not Prev.
+**
+** See also: Found, NotFound, SeekLt, SeekGt, SeekLe
 */
-/* Opcode: SeekGt P1 P2 P3 P4 *
+/* Opcode: SeekGT P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
 **
 ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
 ** use the value in register P3 as a key. If cursor P1 refers 
@@ -66764,9 +80784,14 @@ case OP_Close: {
 ** is greater than the key value. If there are no records greater than 
 ** the key and P2 is not zero, then jump to P2.
 **
-** See also: Found, NotFound, Distinct, SeekLt, SeekGe, SeekLe
+** This opcode leaves the cursor configured to move in forward order,
+** from the beginning toward the end.  In other words, the cursor is
+** configured to use Next, not Prev.
+**
+** See also: Found, NotFound, SeekLt, SeekGe, SeekLe
 */
-/* Opcode: SeekLt P1 P2 P3 P4 * 
+/* Opcode: SeekLT P1 P2 P3 P4 * 
+** Synopsis: key=r[P3@P4]
 **
 ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
 ** use the value in register P3 as a key. If cursor P1 refers 
@@ -66777,9 +80802,14 @@ case OP_Close: {
 ** is less than the key value. If there are no records less than 
 ** the key and P2 is not zero, then jump to P2.
 **
-** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLe
+** This opcode leaves the cursor configured to move in reverse order,
+** from the end toward the beginning.  In other words, the cursor is
+** configured to use Prev, not Next.
+**
+** See also: Found, NotFound, SeekGt, SeekGe, SeekLe
 */
-/* Opcode: SeekLe P1 P2 P3 P4 *
+/* Opcode: SeekLE P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
 **
 ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
 ** use the value in register P3 as a key. If cursor P1 refers 
@@ -66790,192 +80820,189 @@ case OP_Close: {
 ** is less than or equal to the key value. If there are no records 
 ** less than or equal to the key and P2 is not zero, then jump to P2.
 **
-** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLt
-*/
-case OP_SeekLt:         /* jump, in3 */
-case OP_SeekLe:         /* jump, in3 */
-case OP_SeekGe:         /* jump, in3 */
-case OP_SeekGt: {       /* jump, in3 */
-#if 0  /* local variables moved into u.ba */
-  int res;
-  int oc;
-  VdbeCursor *pC;
-  UnpackedRecord r;
-  int nField;
-  i64 iKey;      /* The rowid we are to seek to */
-#endif /* local variables moved into u.ba */
+** This opcode leaves the cursor configured to move in reverse order,
+** from the end toward the beginning.  In other words, the cursor is
+** configured to use Prev, not Next.
+**
+** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
+** opcode will always land on a record that equally equals the key, or
+** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this
+** opcode must be followed by an IdxGE opcode with the same arguments.
+** The IdxGE opcode will be skipped if this opcode succeeds, but the
+** IdxGE opcode will be used on subsequent loop iterations.
+**
+** See also: Found, NotFound, SeekGt, SeekGe, SeekLt
+*/
+case OP_SeekLT:         /* jump, in3 */
+case OP_SeekLE:         /* jump, in3 */
+case OP_SeekGE:         /* jump, in3 */
+case OP_SeekGT: {       /* jump, in3 */
+  int res;           /* Comparison result */
+  int oc;            /* Opcode */
+  VdbeCursor *pC;    /* The cursor to seek */
+  UnpackedRecord r;  /* The key to seek for */
+  int nField;        /* Number of columns or fields in the key */
+  i64 iKey;          /* The rowid we are to seek to */
+  int eqOnly;        /* Only interested in == results */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   assert( pOp->p2!=0 );
-  u.ba.pC = p->apCsr[pOp->p1];
-  assert( u.ba.pC!=0 );
-  assert( u.ba.pC->pseudoTableReg==0 );
-  assert( OP_SeekLe == OP_SeekLt+1 );
-  assert( OP_SeekGe == OP_SeekLt+2 );
-  assert( OP_SeekGt == OP_SeekLt+3 );
-  assert( u.ba.pC->isOrdered );
-  if( ALWAYS(u.ba.pC->pCursor!=0) ){
-    u.ba.oc = pOp->opcode;
-    u.ba.pC->nullRow = 0;
-    if( u.ba.pC->isTable ){
-      /* The input value in P3 might be of any type: integer, real, string,
-      ** blob, or NULL.  But it needs to be an integer before we can do
-      ** the seek, so covert it. */
-      pIn3 = &aMem[pOp->p3];
-      applyNumericAffinity(pIn3);
-      u.ba.iKey = sqlite3VdbeIntValue(pIn3);
-      u.ba.pC->rowidIsValid = 0;
-
-      /* If the P3 value could not be converted into an integer without
-      ** loss of information, then special processing is required... */
-      if( (pIn3->flags & MEM_Int)==0 ){
-        if( (pIn3->flags & MEM_Real)==0 ){
-          /* If the P3 value cannot be converted into any kind of a number,
-          ** then the seek is not possible, so jump to P2 */
-          pc = pOp->p2 - 1;
-          break;
-        }
-        /* If we reach this point, then the P3 value must be a floating
-        ** point number. */
-        assert( (pIn3->flags & MEM_Real)!=0 );
-
-        if( u.ba.iKey==SMALLEST_INT64 && (pIn3->r<(double)u.ba.iKey || pIn3->r>0) ){
-          /* The P3 value is too large in magnitude to be expressed as an
-          ** integer. */
-          u.ba.res = 1;
-          if( pIn3->r<0 ){
-            if( u.ba.oc>=OP_SeekGe ){  assert( u.ba.oc==OP_SeekGe || u.ba.oc==OP_SeekGt );
-              rc = sqlite3BtreeFirst(u.ba.pC->pCursor, &u.ba.res);
-              if( rc!=SQLITE_OK ) goto abort_due_to_error;
-            }
-          }else{
-            if( u.ba.oc<=OP_SeekLe ){  assert( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekLe );
-              rc = sqlite3BtreeLast(u.ba.pC->pCursor, &u.ba.res);
-              if( rc!=SQLITE_OK ) goto abort_due_to_error;
-            }
-          }
-          if( u.ba.res ){
-            pc = pOp->p2 - 1;
-          }
-          break;
-        }else if( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekGe ){
-          /* Use the ceiling() function to convert real->int */
-          if( pIn3->r > (double)u.ba.iKey ) u.ba.iKey++;
-        }else{
-          /* Use the floor() function to convert real->int */
-          assert( u.ba.oc==OP_SeekLe || u.ba.oc==OP_SeekGt );
-          if( pIn3->r < (double)u.ba.iKey ) u.ba.iKey--;
-        }
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( OP_SeekLE == OP_SeekLT+1 );
+  assert( OP_SeekGE == OP_SeekLT+2 );
+  assert( OP_SeekGT == OP_SeekLT+3 );
+  assert( pC->isOrdered );
+  assert( pC->uc.pCursor!=0 );
+  oc = pOp->opcode;
+  eqOnly = 0;
+  pC->nullRow = 0;
+#ifdef SQLITE_DEBUG
+  pC->seekOp = pOp->opcode;
+#endif
+
+  if( pC->isTable ){
+    /* The BTREE_SEEK_EQ flag is only set on index cursors */
+    assert( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ)==0 );
+
+    /* The input value in P3 might be of any type: integer, real, string,
+    ** blob, or NULL.  But it needs to be an integer before we can do
+    ** the seek, so convert it. */
+    pIn3 = &aMem[pOp->p3];
+    if( (pIn3->flags & (MEM_Int|MEM_Real|MEM_Str))==MEM_Str ){
+      applyNumericAffinity(pIn3, 0);
+    }
+    iKey = sqlite3VdbeIntValue(pIn3);
+
+    /* If the P3 value could not be converted into an integer without
+    ** loss of information, then special processing is required... */
+    if( (pIn3->flags & MEM_Int)==0 ){
+      if( (pIn3->flags & MEM_Real)==0 ){
+        /* If the P3 value cannot be converted into any kind of a number,
+        ** then the seek is not possible, so jump to P2 */
+        VdbeBranchTaken(1,2); goto jump_to_p2;
+        break;
       }
-      rc = sqlite3BtreeMovetoUnpacked(u.ba.pC->pCursor, 0, (u64)u.ba.iKey, 0, &u.ba.res);
-      if( rc!=SQLITE_OK ){
-        goto abort_due_to_error;
+
+      /* If the approximation iKey is larger than the actual real search
+      ** term, substitute >= for > and < for <=. e.g. if the search term
+      ** is 4.9 and the integer approximation 5:
+      **
+      **        (x >  4.9)    ->     (x >= 5)
+      **        (x <= 4.9)    ->     (x <  5)
+      */
+      if( pIn3->u.r<(double)iKey ){
+        assert( OP_SeekGE==(OP_SeekGT-1) );
+        assert( OP_SeekLT==(OP_SeekLE-1) );
+        assert( (OP_SeekLE & 0x0001)==(OP_SeekGT & 0x0001) );
+        if( (oc & 0x0001)==(OP_SeekGT & 0x0001) ) oc--;
       }
-      if( u.ba.res==0 ){
-        u.ba.pC->rowidIsValid = 1;
-        u.ba.pC->lastRowid = u.ba.iKey;
+
+      /* If the approximation iKey is smaller than the actual real search
+      ** term, substitute <= for < and > for >=.  */
+      else if( pIn3->u.r>(double)iKey ){
+        assert( OP_SeekLE==(OP_SeekLT+1) );
+        assert( OP_SeekGT==(OP_SeekGE+1) );
+        assert( (OP_SeekLT & 0x0001)==(OP_SeekGE & 0x0001) );
+        if( (oc & 0x0001)==(OP_SeekLT & 0x0001) ) oc++;
       }
-    }else{
-      u.ba.nField = pOp->p4.i;
-      assert( pOp->p4type==P4_INT32 );
-      assert( u.ba.nField>0 );
-      u.ba.r.pKeyInfo = u.ba.pC->pKeyInfo;
-      u.ba.r.nField = (u16)u.ba.nField;
+    } 
+    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)iKey, 0, &res);
+    pC->movetoTarget = iKey;  /* Used by OP_Delete */
+    if( rc!=SQLITE_OK ){
+      goto abort_due_to_error;
+    }
+  }else{
+    /* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and
+    ** OP_SeekLE opcodes are allowed, and these must be immediately followed
+    ** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.
+    */
+    if( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ) ){
+      eqOnly = 1;
+      assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );
+      assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
+      assert( pOp[1].p1==pOp[0].p1 );
+      assert( pOp[1].p2==pOp[0].p2 );
+      assert( pOp[1].p3==pOp[0].p3 );
+      assert( pOp[1].p4.i==pOp[0].p4.i );
+    }
 
-      /* The next line of code computes as follows, only faster:
-      **   if( u.ba.oc==OP_SeekGt || u.ba.oc==OP_SeekLe ){
-      **     u.ba.r.flags = UNPACKED_INCRKEY;
-      **   }else{
-      **     u.ba.r.flags = 0;
-      **   }
-      */
-      u.ba.r.flags = (u16)(UNPACKED_INCRKEY * (1 & (u.ba.oc - OP_SeekLt)));
-      assert( u.ba.oc!=OP_SeekGt || u.ba.r.flags==UNPACKED_INCRKEY );
-      assert( u.ba.oc!=OP_SeekLe || u.ba.r.flags==UNPACKED_INCRKEY );
-      assert( u.ba.oc!=OP_SeekGe || u.ba.r.flags==0 );
-      assert( u.ba.oc!=OP_SeekLt || u.ba.r.flags==0 );
+    nField = pOp->p4.i;
+    assert( pOp->p4type==P4_INT32 );
+    assert( nField>0 );
+    r.pKeyInfo = pC->pKeyInfo;
+    r.nField = (u16)nField;
+
+    /* The next line of code computes as follows, only faster:
+    **   if( oc==OP_SeekGT || oc==OP_SeekLE ){
+    **     r.default_rc = -1;
+    **   }else{
+    **     r.default_rc = +1;
+    **   }
+    */
+    r.default_rc = ((1 & (oc - OP_SeekLT)) ? -1 : +1);
+    assert( oc!=OP_SeekGT || r.default_rc==-1 );
+    assert( oc!=OP_SeekLE || r.default_rc==-1 );
+    assert( oc!=OP_SeekGE || r.default_rc==+1 );
+    assert( oc!=OP_SeekLT || r.default_rc==+1 );
 
-      u.ba.r.aMem = &aMem[pOp->p3];
+    r.aMem = &aMem[pOp->p3];
 #ifdef SQLITE_DEBUG
-      { int i; for(i=0; i<u.ba.r.nField; i++) assert( memIsValid(&u.ba.r.aMem[i]) ); }
+    { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
 #endif
-      ExpandBlob(u.ba.r.aMem);
-      rc = sqlite3BtreeMovetoUnpacked(u.ba.pC->pCursor, &u.ba.r, 0, 0, &u.ba.res);
-      if( rc!=SQLITE_OK ){
-        goto abort_due_to_error;
-      }
-      u.ba.pC->rowidIsValid = 0;
+    ExpandBlob(r.aMem);
+    r.eqSeen = 0;
+    rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, &r, 0, 0, &res);
+    if( rc!=SQLITE_OK ){
+      goto abort_due_to_error;
+    }
+    if( eqOnly && r.eqSeen==0 ){
+      assert( res!=0 );
+      goto seek_not_found;
     }
-    u.ba.pC->deferredMoveto = 0;
-    u.ba.pC->cacheStatus = CACHE_STALE;
+  }
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
 #ifdef SQLITE_TEST
-    sqlite3_search_count++;
+  sqlite3_search_count++;
 #endif
-    if( u.ba.oc>=OP_SeekGe ){  assert( u.ba.oc==OP_SeekGe || u.ba.oc==OP_SeekGt );
-      if( u.ba.res<0 || (u.ba.res==0 && u.ba.oc==OP_SeekGt) ){
-        rc = sqlite3BtreeNext(u.ba.pC->pCursor, &u.ba.res);
-        if( rc!=SQLITE_OK ) goto abort_due_to_error;
-        u.ba.pC->rowidIsValid = 0;
-      }else{
-        u.ba.res = 0;
-      }
+  if( oc>=OP_SeekGE ){  assert( oc==OP_SeekGE || oc==OP_SeekGT );
+    if( res<0 || (res==0 && oc==OP_SeekGT) ){
+      res = 0;
+      rc = sqlite3BtreeNext(pC->uc.pCursor, &res);
+      if( rc!=SQLITE_OK ) goto abort_due_to_error;
     }else{
-      assert( u.ba.oc==OP_SeekLt || u.ba.oc==OP_SeekLe );
-      if( u.ba.res>0 || (u.ba.res==0 && u.ba.oc==OP_SeekLt) ){
-        rc = sqlite3BtreePrevious(u.ba.pC->pCursor, &u.ba.res);
-        if( rc!=SQLITE_OK ) goto abort_due_to_error;
-        u.ba.pC->rowidIsValid = 0;
-      }else{
-        /* u.ba.res might be negative because the table is empty.  Check to
-        ** see if this is the case.
-        */
-        u.ba.res = sqlite3BtreeEof(u.ba.pC->pCursor);
-      }
-    }
-    assert( pOp->p2>0 );
-    if( u.ba.res ){
-      pc = pOp->p2 - 1;
+      res = 0;
     }
   }else{
-    /* This happens when attempting to open the sqlite3_master table
-    ** for read access returns SQLITE_EMPTY. In this case always
-    ** take the jump (since there are no records in the table).
-    */
-    pc = pOp->p2 - 1;
+    assert( oc==OP_SeekLT || oc==OP_SeekLE );
+    if( res>0 || (res==0 && oc==OP_SeekLT) ){
+      res = 0;
+      rc = sqlite3BtreePrevious(pC->uc.pCursor, &res);
+      if( rc!=SQLITE_OK ) goto abort_due_to_error;
+    }else{
+      /* res might be negative because the table is empty.  Check to
+      ** see if this is the case.
+      */
+      res = sqlite3BtreeEof(pC->uc.pCursor);
+    }
   }
-  break;
-}
-
-/* Opcode: Seek P1 P2 * * *
-**
-** P1 is an open table cursor and P2 is a rowid integer.  Arrange
-** for P1 to move so that it points to the rowid given by P2.
-**
-** This is actually a deferred seek.  Nothing actually happens until
-** the cursor is used to read a record.  That way, if no reads
-** occur, no unnecessary I/O happens.
-*/
-case OP_Seek: {    /* in2 */
-#if 0  /* local variables moved into u.bb */
-  VdbeCursor *pC;
-#endif /* local variables moved into u.bb */
-
-  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bb.pC = p->apCsr[pOp->p1];
-  assert( u.bb.pC!=0 );
-  if( ALWAYS(u.bb.pC->pCursor!=0) ){
-    assert( u.bb.pC->isTable );
-    u.bb.pC->nullRow = 0;
-    pIn2 = &aMem[pOp->p2];
-    u.bb.pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
-    u.bb.pC->rowidIsValid = 0;
-    u.bb.pC->deferredMoveto = 1;
+seek_not_found:
+  assert( pOp->p2>0 );
+  VdbeBranchTaken(res!=0,2);
+  if( res ){
+    goto jump_to_p2;
+  }else if( eqOnly ){
+    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
+    pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */
   }
   break;
 }
   
 
 /* Opcode: Found P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
 **
 ** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
 ** P4>0 then register P3 is the first of P4 registers that form an unpacked
@@ -66984,8 +81011,15 @@ case OP_Seek: {    /* in2 */
 ** Cursor P1 is on an index btree.  If the record identified by P3 and P4
 ** is a prefix of any entry in P1 then a jump is made to P2 and
 ** P1 is left pointing at the matching entry.
+**
+** This operation leaves the cursor in a state where it can be
+** advanced in the forward direction.  The Next instruction will work,
+** but not the Prev instruction.
+**
+** See also: NotFound, NoConflict, NotExists. SeekGe
 */
 /* Opcode: NotFound P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
 **
 ** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
 ** P4>0 then register P3 is the first of P4 registers that form an unpacked
@@ -66997,231 +81031,232 @@ case OP_Seek: {    /* in2 */
 ** falls through to the next instruction and P1 is left pointing at the
 ** matching entry.
 **
-** See also: Found, NotExists, IsUnique
+** This operation leaves the cursor in a state where it cannot be
+** advanced in either direction.  In other words, the Next and Prev
+** opcodes do not work after this operation.
+**
+** See also: Found, NotExists, NoConflict
 */
+/* Opcode: NoConflict P1 P2 P3 P4 *
+** Synopsis: key=r[P3@P4]
+**
+** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
+** P4>0 then register P3 is the first of P4 registers that form an unpacked
+** record.
+** 
+** Cursor P1 is on an index btree.  If the record identified by P3 and P4
+** contains any NULL value, jump immediately to P2.  If all terms of the
+** record are not-NULL then a check is done to determine if any row in the
+** P1 index btree has a matching key prefix.  If there are no matches, jump
+** immediately to P2.  If there is a match, fall through and leave the P1
+** cursor pointing to the matching row.
+**
+** This opcode is similar to OP_NotFound with the exceptions that the
+** branch is always taken if any part of the search key input is NULL.
+**
+** This operation leaves the cursor in a state where it cannot be
+** advanced in either direction.  In other words, the Next and Prev
+** opcodes do not work after this operation.
+**
+** See also: NotFound, Found, NotExists
+*/
+case OP_NoConflict:     /* jump, in3 */
 case OP_NotFound:       /* jump, in3 */
 case OP_Found: {        /* jump, in3 */
-#if 0  /* local variables moved into u.bc */
   int alreadyExists;
+  int takeJump;
+  int ii;
   VdbeCursor *pC;
   int res;
   char *pFree;
   UnpackedRecord *pIdxKey;
   UnpackedRecord r;
-  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
-#endif /* local variables moved into u.bc */
+  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*4 + 7];
 
 #ifdef SQLITE_TEST
-  sqlite3_found_count++;
+  if( pOp->opcode!=OP_NoConflict ) sqlite3_found_count++;
 #endif
 
-  u.bc.alreadyExists = 0;
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   assert( pOp->p4type==P4_INT32 );
-  u.bc.pC = p->apCsr[pOp->p1];
-  assert( u.bc.pC!=0 );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+#ifdef SQLITE_DEBUG
+  pC->seekOp = pOp->opcode;
+#endif
   pIn3 = &aMem[pOp->p3];
-  if( ALWAYS(u.bc.pC->pCursor!=0) ){
-
-    assert( u.bc.pC->isTable==0 );
-    if( pOp->p4.i>0 ){
-      u.bc.r.pKeyInfo = u.bc.pC->pKeyInfo;
-      u.bc.r.nField = (u16)pOp->p4.i;
-      u.bc.r.aMem = pIn3;
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  assert( pC->isTable==0 );
+  pFree = 0;
+  if( pOp->p4.i>0 ){
+    r.pKeyInfo = pC->pKeyInfo;
+    r.nField = (u16)pOp->p4.i;
+    r.aMem = pIn3;
+    for(ii=0; ii<r.nField; ii++){
+      assert( memIsValid(&r.aMem[ii]) );
+      ExpandBlob(&r.aMem[ii]);
 #ifdef SQLITE_DEBUG
-      { int i; for(i=0; i<u.bc.r.nField; i++) assert( memIsValid(&u.bc.r.aMem[i]) ); }
+      if( ii ) REGISTER_TRACE(pOp->p3+ii, &r.aMem[ii]);
 #endif
-      u.bc.r.flags = UNPACKED_PREFIX_MATCH;
-      u.bc.pIdxKey = &u.bc.r;
-    }else{
-      u.bc.pIdxKey = sqlite3VdbeAllocUnpackedRecord(
-          u.bc.pC->pKeyInfo, u.bc.aTempRec, sizeof(u.bc.aTempRec), &u.bc.pFree
-      );
-      if( u.bc.pIdxKey==0 ) goto no_mem;
-      assert( pIn3->flags & MEM_Blob );
-      assert( (pIn3->flags & MEM_Zero)==0 );  /* zeroblobs already expanded */
-      sqlite3VdbeRecordUnpack(u.bc.pC->pKeyInfo, pIn3->n, pIn3->z, u.bc.pIdxKey);
-      u.bc.pIdxKey->flags |= UNPACKED_PREFIX_MATCH;
-    }
-    rc = sqlite3BtreeMovetoUnpacked(u.bc.pC->pCursor, u.bc.pIdxKey, 0, 0, &u.bc.res);
-    if( pOp->p4.i==0 ){
-      sqlite3DbFree(db, u.bc.pFree);
     }
-    if( rc!=SQLITE_OK ){
-      break;
+    pIdxKey = &r;
+  }else{
+    pIdxKey = sqlite3VdbeAllocUnpackedRecord(
+        pC->pKeyInfo, aTempRec, sizeof(aTempRec), &pFree
+    );
+    if( pIdxKey==0 ) goto no_mem;
+    assert( pIn3->flags & MEM_Blob );
+    ExpandBlob(pIn3);
+    sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z, pIdxKey);
+  }
+  pIdxKey->default_rc = 0;
+  takeJump = 0;
+  if( pOp->opcode==OP_NoConflict ){
+    /* For the OP_NoConflict opcode, take the jump if any of the
+    ** input fields are NULL, since any key with a NULL will not
+    ** conflict */
+    for(ii=0; ii<pIdxKey->nField; ii++){
+      if( pIdxKey->aMem[ii].flags & MEM_Null ){
+        takeJump = 1;
+        break;
+      }
     }
-    u.bc.alreadyExists = (u.bc.res==0);
-    u.bc.pC->deferredMoveto = 0;
-    u.bc.pC->cacheStatus = CACHE_STALE;
   }
+  rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, pIdxKey, 0, 0, &res);
+  sqlite3DbFree(db, pFree);
+  if( rc!=SQLITE_OK ){
+    goto abort_due_to_error;
+  }
+  pC->seekResult = res;
+  alreadyExists = (res==0);
+  pC->nullRow = 1-alreadyExists;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
   if( pOp->opcode==OP_Found ){
-    if( u.bc.alreadyExists ) pc = pOp->p2 - 1;
+    VdbeBranchTaken(alreadyExists!=0,2);
+    if( alreadyExists ) goto jump_to_p2;
   }else{
-    if( !u.bc.alreadyExists ) pc = pOp->p2 - 1;
+    VdbeBranchTaken(takeJump||alreadyExists==0,2);
+    if( takeJump || !alreadyExists ) goto jump_to_p2;
   }
   break;
 }
 
-/* Opcode: IsUnique P1 P2 P3 P4 *
+/* Opcode: SeekRowid P1 P2 P3 * *
+** Synopsis: intkey=r[P3]
 **
-** Cursor P1 is open on an index b-tree - that is to say, a btree which
-** no data and where the key are records generated by OP_MakeRecord with
-** the list field being the integer ROWID of the entry that the index
-** entry refers to.
+** P1 is the index of a cursor open on an SQL table btree (with integer
+** keys).  If register P3 does not contain an integer or if P1 does not
+** contain a record with rowid P3 then jump immediately to P2.  
+** Or, if P2 is 0, raise an SQLITE_CORRUPT error. If P1 does contain
+** a record with rowid P3 then 
+** leave the cursor pointing at that record and fall through to the next
+** instruction.
 **
-** The P3 register contains an integer record number. Call this record 
-** number R. Register P4 is the first in a set of N contiguous registers
-** that make up an unpacked index key that can be used with cursor P1.
-** The value of N can be inferred from the cursor. N includes the rowid
-** value appended to the end of the index record. This rowid value may
-** or may not be the same as R.
+** The OP_NotExists opcode performs the same operation, but with OP_NotExists
+** the P3 register must be guaranteed to contain an integer value.  With this
+** opcode, register P3 might not contain an integer.
 **
-** If any of the N registers beginning with register P4 contains a NULL
-** value, jump immediately to P2.
+** The OP_NotFound opcode performs the same operation on index btrees
+** (with arbitrary multi-value keys).
 **
-** Otherwise, this instruction checks if cursor P1 contains an entry
-** where the first (N-1) fields match but the rowid value at the end
-** of the index entry is not R. If there is no such entry, control jumps
-** to instruction P2. Otherwise, the rowid of the conflicting index
-** entry is copied to register P3 and control falls through to the next
-** instruction.
+** This opcode leaves the cursor in a state where it cannot be advanced
+** in either direction.  In other words, the Next and Prev opcodes will
+** not work following this opcode.
 **
-** See also: NotFound, NotExists, Found
+** See also: Found, NotFound, NoConflict, SeekRowid
 */
-case OP_IsUnique: {        /* jump, in3 */
-#if 0  /* local variables moved into u.bd */
-  u16 ii;
-  VdbeCursor *pCx;
-  BtCursor *pCrsr;
-  u16 nField;
-  Mem *aMx;
-  UnpackedRecord r;                  /* B-Tree index search key */
-  i64 R;                             /* Rowid stored in register P3 */
-#endif /* local variables moved into u.bd */
-
-  pIn3 = &aMem[pOp->p3];
-  u.bd.aMx = &aMem[pOp->p4.i];
-  /* Assert that the values of parameters P1 and P4 are in range. */
-  assert( pOp->p4type==P4_INT32 );
-  assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
-  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-
-  /* Find the index cursor. */
-  u.bd.pCx = p->apCsr[pOp->p1];
-  assert( u.bd.pCx->deferredMoveto==0 );
-  u.bd.pCx->seekResult = 0;
-  u.bd.pCx->cacheStatus = CACHE_STALE;
-  u.bd.pCrsr = u.bd.pCx->pCursor;
-
-  /* If any of the values are NULL, take the jump. */
-  u.bd.nField = u.bd.pCx->pKeyInfo->nField;
-  for(u.bd.ii=0; u.bd.ii<u.bd.nField; u.bd.ii++){
-    if( u.bd.aMx[u.bd.ii].flags & MEM_Null ){
-      pc = pOp->p2 - 1;
-      u.bd.pCrsr = 0;
-      break;
-    }
-  }
-  assert( (u.bd.aMx[u.bd.nField].flags & MEM_Null)==0 );
-
-  if( u.bd.pCrsr!=0 ){
-    /* Populate the index search key. */
-    u.bd.r.pKeyInfo = u.bd.pCx->pKeyInfo;
-    u.bd.r.nField = u.bd.nField + 1;
-    u.bd.r.flags = UNPACKED_PREFIX_SEARCH;
-    u.bd.r.aMem = u.bd.aMx;
-#ifdef SQLITE_DEBUG
-    { int i; for(i=0; i<u.bd.r.nField; i++) assert( memIsValid(&u.bd.r.aMem[i]) ); }
-#endif
-
-    /* Extract the value of u.bd.R from register P3. */
-    sqlite3VdbeMemIntegerify(pIn3);
-    u.bd.R = pIn3->u.i;
-
-    /* Search the B-Tree index. If no conflicting record is found, jump
-    ** to P2. Otherwise, copy the rowid of the conflicting record to
-    ** register P3 and fall through to the next instruction.  */
-    rc = sqlite3BtreeMovetoUnpacked(u.bd.pCrsr, &u.bd.r, 0, 0, &u.bd.pCx->seekResult);
-    if( (u.bd.r.flags & UNPACKED_PREFIX_SEARCH) || u.bd.r.rowid==u.bd.R ){
-      pc = pOp->p2 - 1;
-    }else{
-      pIn3->u.i = u.bd.r.rowid;
-    }
-  }
-  break;
-}
-
 /* Opcode: NotExists P1 P2 P3 * *
+** Synopsis: intkey=r[P3]
 **
-** Use the content of register P3 as an integer key.  If a record 
-** with that key does not exist in table of P1, then jump to P2. 
-** If the record does exist, then fall through.  The cursor is left 
-** pointing to the record if it exists.
+** P1 is the index of a cursor open on an SQL table btree (with integer
+** keys).  P3 is an integer rowid.  If P1 does not contain a record with
+** rowid P3 then jump immediately to P2.  Or, if P2 is 0, raise an
+** SQLITE_CORRUPT error. If P1 does contain a record with rowid P3 then 
+** leave the cursor pointing at that record and fall through to the next
+** instruction.
 **
-** The difference between this operation and NotFound is that this
-** operation assumes the key is an integer and that P1 is a table whereas
-** NotFound assumes key is a blob constructed from MakeRecord and
-** P1 is an index.
+** The OP_SeekRowid opcode performs the same operation but also allows the
+** P3 register to contain a non-integer value, in which case the jump is
+** always taken.  This opcode requires that P3 always contain an integer.
 **
-** See also: Found, NotFound, IsUnique
+** The OP_NotFound opcode performs the same operation on index btrees
+** (with arbitrary multi-value keys).
+**
+** This opcode leaves the cursor in a state where it cannot be advanced
+** in either direction.  In other words, the Next and Prev opcodes will
+** not work following this opcode.
+**
+** See also: Found, NotFound, NoConflict, SeekRowid
 */
-case OP_NotExists: {        /* jump, in3 */
-#if 0  /* local variables moved into u.be */
+case OP_SeekRowid: {        /* jump, in3 */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
   u64 iKey;
-#endif /* local variables moved into u.be */
 
   pIn3 = &aMem[pOp->p3];
+  if( (pIn3->flags & MEM_Int)==0 ){
+    applyAffinity(pIn3, SQLITE_AFF_NUMERIC, encoding);
+    if( (pIn3->flags & MEM_Int)==0 ) goto jump_to_p2;
+  }
+  /* Fall through into OP_NotExists */
+case OP_NotExists:          /* jump, in3 */
+  pIn3 = &aMem[pOp->p3];
   assert( pIn3->flags & MEM_Int );
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.be.pC = p->apCsr[pOp->p1];
-  assert( u.be.pC!=0 );
-  assert( u.be.pC->isTable );
-  assert( u.be.pC->pseudoTableReg==0 );
-  u.be.pCrsr = u.be.pC->pCursor;
-  if( ALWAYS(u.be.pCrsr!=0) ){
-    u.be.res = 0;
-    u.be.iKey = pIn3->u.i;
-    rc = sqlite3BtreeMovetoUnpacked(u.be.pCrsr, 0, u.be.iKey, 0, &u.be.res);
-    u.be.pC->lastRowid = pIn3->u.i;
-    u.be.pC->rowidIsValid = u.be.res==0 ?1:0;
-    u.be.pC->nullRow = 0;
-    u.be.pC->cacheStatus = CACHE_STALE;
-    u.be.pC->deferredMoveto = 0;
-    if( u.be.res!=0 ){
-      pc = pOp->p2 - 1;
-      assert( u.be.pC->rowidIsValid==0 );
-    }
-    u.be.pC->seekResult = u.be.res;
-  }else{
-    /* This happens when an attempt to open a read cursor on the
-    ** sqlite_master table returns SQLITE_EMPTY.
-    */
-    pc = pOp->p2 - 1;
-    assert( u.be.pC->rowidIsValid==0 );
-    u.be.pC->seekResult = 0;
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+#ifdef SQLITE_DEBUG
+  pC->seekOp = 0;
+#endif
+  assert( pC->isTable );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
+  assert( pCrsr!=0 );
+  res = 0;
+  iKey = pIn3->u.i;
+  rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);
+  assert( rc==SQLITE_OK || res==0 );
+  pC->movetoTarget = iKey;  /* Used by OP_Delete */
+  pC->nullRow = 0;
+  pC->cacheStatus = CACHE_STALE;
+  pC->deferredMoveto = 0;
+  VdbeBranchTaken(res!=0,2);
+  pC->seekResult = res;
+  if( res!=0 ){
+    assert( rc==SQLITE_OK );
+    if( pOp->p2==0 ){
+      rc = SQLITE_CORRUPT_BKPT;
+    }else{
+      goto jump_to_p2;
+    }
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 
 /* Opcode: Sequence P1 P2 * * *
+** Synopsis: r[P2]=cursor[P1].ctr++
 **
 ** Find the next available sequence number for cursor P1.
 ** Write the sequence number into register P2.
 ** The sequence number on the cursor is incremented after this
 ** instruction.  
 */
-case OP_Sequence: {           /* out2-prerelease */
+case OP_Sequence: {           /* out2 */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   assert( p->apCsr[pOp->p1]!=0 );
+  assert( p->apCsr[pOp->p1]->eCurType!=CURTYPE_VTAB );
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = p->apCsr[pOp->p1]->seqCount++;
   break;
 }
 
 
 /* Opcode: NewRowid P1 P2 P3 * *
+** Synopsis: r[P2]=rowid
 **
 ** Get a new integer record number (a.k.a "rowid") used as the key to a table.
 ** The record number is not previously used as a key in the database
@@ -67235,24 +81270,23 @@ case OP_Sequence: {           /* out2-prerelease */
 ** generated record number. This P3 mechanism is used to help implement the
 ** AUTOINCREMENT feature.
 */
-case OP_NewRowid: {           /* out2-prerelease */
-#if 0  /* local variables moved into u.bf */
+case OP_NewRowid: {           /* out2 */
   i64 v;                 /* The new rowid */
   VdbeCursor *pC;        /* Cursor of table to get the new rowid */
   int res;               /* Result of an sqlite3BtreeLast() */
   int cnt;               /* Counter to limit the number of searches */
   Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */
   VdbeFrame *pFrame;     /* Root frame of VDBE */
-#endif /* local variables moved into u.bf */
 
-  u.bf.v = 0;
-  u.bf.res = 0;
+  v = 0;
+  res = 0;
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bf.pC = p->apCsr[pOp->p1];
-  assert( u.bf.pC!=0 );
-  if( NEVER(u.bf.pC->pCursor==0) ){
-    /* The zero initialization above is all that is needed */
-  }else{
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  {
     /* The next rowid or record number (different terms for the same
     ** thing) is obtained in a two-step algorithm.
     **
@@ -67266,7 +81300,7 @@ case OP_NewRowid: {           /* out2-prerelease */
     ** succeeded.  If the random rowid does exist, we select a new one
     ** and try again, up to 100 times.
     */
-    assert( u.bf.pC->isTable );
+    assert( pC->isTable );
 
 #ifdef SQLITE_32BIT_ROWID
 #   define MAX_ROWID 0x7fffffff
@@ -67278,101 +81312,85 @@ case OP_NewRowid: {           /* out2-prerelease */
 #   define MAX_ROWID  (i64)( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
 #endif
 
-    if( !u.bf.pC->useRandomRowid ){
-      u.bf.v = sqlite3BtreeGetCachedRowid(u.bf.pC->pCursor);
-      if( u.bf.v==0 ){
-        rc = sqlite3BtreeLast(u.bf.pC->pCursor, &u.bf.res);
-        if( rc!=SQLITE_OK ){
-          goto abort_due_to_error;
-        }
-        if( u.bf.res ){
-          u.bf.v = 1;   /* IMP: R-61914-48074 */
+    if( !pC->useRandomRowid ){
+      rc = sqlite3BtreeLast(pC->uc.pCursor, &res);
+      if( rc!=SQLITE_OK ){
+        goto abort_due_to_error;
+      }
+      if( res ){
+        v = 1;   /* IMP: R-61914-48074 */
+      }else{
+        assert( sqlite3BtreeCursorIsValid(pC->uc.pCursor) );
+        v = sqlite3BtreeIntegerKey(pC->uc.pCursor);
+        if( v>=MAX_ROWID ){
+          pC->useRandomRowid = 1;
         }else{
-          assert( sqlite3BtreeCursorIsValid(u.bf.pC->pCursor) );
-          rc = sqlite3BtreeKeySize(u.bf.pC->pCursor, &u.bf.v);
-          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
-          if( u.bf.v==MAX_ROWID ){
-            u.bf.pC->useRandomRowid = 1;
-          }else{
-            u.bf.v++;   /* IMP: R-29538-34987 */
-          }
+          v++;   /* IMP: R-29538-34987 */
         }
       }
+    }
 
 #ifndef SQLITE_OMIT_AUTOINCREMENT
-      if( pOp->p3 ){
+    if( pOp->p3 ){
+      /* Assert that P3 is a valid memory cell. */
+      assert( pOp->p3>0 );
+      if( p->pFrame ){
+        for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
         /* Assert that P3 is a valid memory cell. */
-        assert( pOp->p3>0 );
-        if( p->pFrame ){
-          for(u.bf.pFrame=p->pFrame; u.bf.pFrame->pParent; u.bf.pFrame=u.bf.pFrame->pParent);
-          /* Assert that P3 is a valid memory cell. */
-          assert( pOp->p3<=u.bf.pFrame->nMem );
-          u.bf.pMem = &u.bf.pFrame->aMem[pOp->p3];
-        }else{
-          /* Assert that P3 is a valid memory cell. */
-          assert( pOp->p3<=p->nMem );
-          u.bf.pMem = &aMem[pOp->p3];
-          memAboutToChange(p, u.bf.pMem);
-        }
-        assert( memIsValid(u.bf.pMem) );
-
-        REGISTER_TRACE(pOp->p3, u.bf.pMem);
-        sqlite3VdbeMemIntegerify(u.bf.pMem);
-        assert( (u.bf.pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
-        if( u.bf.pMem->u.i==MAX_ROWID || u.bf.pC->useRandomRowid ){
-          rc = SQLITE_FULL;   /* IMP: R-12275-61338 */
-          goto abort_due_to_error;
-        }
-        if( u.bf.v<u.bf.pMem->u.i+1 ){
-          u.bf.v = u.bf.pMem->u.i + 1;
-        }
-        u.bf.pMem->u.i = u.bf.v;
+        assert( pOp->p3<=pFrame->nMem );
+        pMem = &pFrame->aMem[pOp->p3];
+      }else{
+        /* Assert that P3 is a valid memory cell. */
+        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
+        pMem = &aMem[pOp->p3];
+        memAboutToChange(p, pMem);
       }
-#endif
+      assert( memIsValid(pMem) );
 
-      sqlite3BtreeSetCachedRowid(u.bf.pC->pCursor, u.bf.v<MAX_ROWID ? u.bf.v+1 : 0);
+      REGISTER_TRACE(pOp->p3, pMem);
+      sqlite3VdbeMemIntegerify(pMem);
+      assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
+      if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
+        rc = SQLITE_FULL;   /* IMP: R-12275-61338 */
+        goto abort_due_to_error;
+      }
+      if( v<pMem->u.i+1 ){
+        v = pMem->u.i + 1;
+      }
+      pMem->u.i = v;
     }
-    if( u.bf.pC->useRandomRowid ){
+#endif
+    if( pC->useRandomRowid ){
       /* IMPLEMENTATION-OF: R-07677-41881 If the largest ROWID is equal to the
       ** largest possible integer (9223372036854775807) then the database
       ** engine starts picking positive candidate ROWIDs at random until
       ** it finds one that is not previously used. */
       assert( pOp->p3==0 );  /* We cannot be in random rowid mode if this is
                              ** an AUTOINCREMENT table. */
-      /* on the first attempt, simply do one more than previous */
-      u.bf.v = lastRowid;
-      u.bf.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
-      u.bf.v++; /* ensure non-zero */
-      u.bf.cnt = 0;
-      while(   ((rc = sqlite3BtreeMovetoUnpacked(u.bf.pC->pCursor, 0, (u64)u.bf.v,
-                                                 0, &u.bf.res))==SQLITE_OK)
-            && (u.bf.res==0)
-            && (++u.bf.cnt<100)){
-        /* collision - try another random rowid */
-        sqlite3_randomness(sizeof(u.bf.v), &u.bf.v);
-        if( u.bf.cnt<5 ){
-          /* try "small" random rowids for the initial attempts */
-          u.bf.v &= 0xffffff;
-        }else{
-          u.bf.v &= (MAX_ROWID>>1); /* ensure doesn't go negative */
-        }
-        u.bf.v++; /* ensure non-zero */
-      }
-      if( rc==SQLITE_OK && u.bf.res==0 ){
+      cnt = 0;
+      do{
+        sqlite3_randomness(sizeof(v), &v);
+        v &= (MAX_ROWID>>1); v++;  /* Ensure that v is greater than zero */
+      }while(  ((rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)v,
+                                                 0, &res))==SQLITE_OK)
+            && (res==0)
+            && (++cnt<100));
+      if( rc ) goto abort_due_to_error;
+      if( res==0 ){
         rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
         goto abort_due_to_error;
       }
-      assert( u.bf.v>0 );  /* EV: R-40812-03570 */
+      assert( v>0 );  /* EV: R-40812-03570 */
     }
-    u.bf.pC->rowidIsValid = 0;
-    u.bf.pC->deferredMoveto = 0;
-    u.bf.pC->cacheStatus = CACHE_STALE;
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
   }
-  pOut->u.i = u.bf.v;
+  pOut->u.i = v;
   break;
 }
 
 /* Opcode: Insert P1 P2 P3 P4 P5
+** Synopsis: intkey=r[P3] data=r[P2]
 **
 ** Write an entry into the table of cursor P1.  A new entry is
 ** created if it doesn't already exist or the data for an existing
@@ -67386,10 +81404,12 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
 **
 ** If the OPFLAG_USESEEKRESULT flag of P5 is set and if the result of
-** the last seek operation (OP_NotExists) was a success, then this
+** the last seek operation (OP_NotExists or OP_SeekRowid) was a success,
+** then this
 ** operation will not attempt to find the appropriate row before doing
 ** the insert but will instead overwrite the row that the cursor is
-** currently pointing to.  Presumably, the prior OP_NotExists opcode
+** currently pointing to.  Presumably, the prior OP_NotExists or
+** OP_SeekRowid opcode
 ** has already positioned the cursor correctly.  This is an optimization
 ** that boosts performance by avoiding redundant seeks.
 **
@@ -67398,9 +81418,9 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** is part of an INSERT operation.  The difference is only important to
 ** the update hook.
 **
-** Parameter P4 may point to a string containing the table-name, or
-** may be NULL. If it is not NULL, then the update-hook 
-** (sqlite3.xUpdateCallback) is invoked following a successful insert.
+** Parameter P4 may point to a Table structure, or may be NULL. If it is 
+** not NULL, then the update-hook (sqlite3.xUpdateCallback) is invoked 
+** following a successful insert.
 **
 ** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
 ** allocated, then ownership of P2 is transferred to the pseudo-cursor
@@ -67412,144 +81432,221 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** for indices is OP_IdxInsert.
 */
 /* Opcode: InsertInt P1 P2 P3 P4 P5
+** Synopsis:  intkey=P3 data=r[P2]
 **
 ** This works exactly like OP_Insert except that the key is the
 ** integer value P3, not the value of the integer stored in register P3.
 */
 case OP_Insert: 
 case OP_InsertInt: {
-#if 0  /* local variables moved into u.bg */
   Mem *pData;       /* MEM cell holding data for the record to be inserted */
   Mem *pKey;        /* MEM cell holding key  for the record */
-  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
   VdbeCursor *pC;   /* Cursor to table into which insert is written */
-  int nZero;        /* Number of zero-bytes to append */
   int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
   const char *zDb;  /* database name - used by the update hook */
-  const char *zTbl; /* Table name - used by the opdate hook */
+  Table *pTab;      /* Table structure - used by update and pre-update hooks */
   int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
-#endif /* local variables moved into u.bg */
+  BtreePayload x;   /* Payload to be inserted */
 
-  u.bg.pData = &aMem[pOp->p2];
+  op = 0;
+  pData = &aMem[pOp->p2];
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  assert( memIsValid(u.bg.pData) );
-  u.bg.pC = p->apCsr[pOp->p1];
-  assert( u.bg.pC!=0 );
-  assert( u.bg.pC->pCursor!=0 );
-  assert( u.bg.pC->pseudoTableReg==0 );
-  assert( u.bg.pC->isTable );
-  REGISTER_TRACE(pOp->p2, u.bg.pData);
+  assert( memIsValid(pData) );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  assert( pC->isTable );
+  assert( pOp->p4type==P4_TABLE || pOp->p4type>=P4_STATIC );
+  REGISTER_TRACE(pOp->p2, pData);
 
   if( pOp->opcode==OP_Insert ){
-    u.bg.pKey = &aMem[pOp->p3];
-    assert( u.bg.pKey->flags & MEM_Int );
-    assert( memIsValid(u.bg.pKey) );
-    REGISTER_TRACE(pOp->p3, u.bg.pKey);
-    u.bg.iKey = u.bg.pKey->u.i;
+    pKey = &aMem[pOp->p3];
+    assert( pKey->flags & MEM_Int );
+    assert( memIsValid(pKey) );
+    REGISTER_TRACE(pOp->p3, pKey);
+    x.nKey = pKey->u.i;
   }else{
     assert( pOp->opcode==OP_InsertInt );
-    u.bg.iKey = pOp->p3;
+    x.nKey = pOp->p3;
   }
 
+  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
+    assert( pC->isTable );
+    assert( pC->iDb>=0 );
+    zDb = db->aDb[pC->iDb].zName;
+    pTab = pOp->p4.pTab;
+    assert( HasRowid(pTab) );
+    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
+  }else{
+    pTab = 0; /* Not needed.  Silence a comiler warning. */
+    zDb = 0;  /* Not needed.  Silence a compiler warning. */
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update hook, if any */
+  if( db->xPreUpdateCallback 
+   && pOp->p4type==P4_TABLE
+   && !(pOp->p5 & OPFLAG_ISUPDATE)
+  ){
+    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey, pOp->p2);
+  }
+#endif
+
   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
-  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = u.bg.iKey;
-  if( u.bg.pData->flags & MEM_Null ){
-    u.bg.pData->z = 0;
-    u.bg.pData->n = 0;
+  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = x.nKey;
+  if( pData->flags & MEM_Null ){
+    x.pData = 0;
+    x.nData = 0;
   }else{
-    assert( u.bg.pData->flags & (MEM_Blob|MEM_Str) );
+    assert( pData->flags & (MEM_Blob|MEM_Str) );
+    x.pData = pData->z;
+    x.nData = pData->n;
   }
-  u.bg.seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bg.pC->seekResult : 0);
-  if( u.bg.pData->flags & MEM_Zero ){
-    u.bg.nZero = u.bg.pData->u.nZero;
+  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
+  if( pData->flags & MEM_Zero ){
+    x.nZero = pData->u.nZero;
   }else{
-    u.bg.nZero = 0;
+    x.nZero = 0;
   }
-  sqlite3BtreeSetCachedRowid(u.bg.pC->pCursor, 0);
-  rc = sqlite3BtreeInsert(u.bg.pC->pCursor, 0, u.bg.iKey,
-                          u.bg.pData->z, u.bg.pData->n, u.bg.nZero,
-                          pOp->p5 & OPFLAG_APPEND, u.bg.seekResult
+  x.pKey = 0;
+  rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,
+                          (pOp->p5 & OPFLAG_APPEND)!=0, seekResult
   );
-  u.bg.pC->rowidIsValid = 0;
-  u.bg.pC->deferredMoveto = 0;
-  u.bg.pC->cacheStatus = CACHE_STALE;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
 
   /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
-    u.bg.zDb = db->aDb[u.bg.pC->iDb].zName;
-    u.bg.zTbl = pOp->p4.z;
-    u.bg.op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
-    assert( u.bg.pC->isTable );
-    db->xUpdateCallback(db->pUpdateArg, u.bg.op, u.bg.zDb, u.bg.zTbl, u.bg.iKey);
-    assert( u.bg.pC->iDb>=0 );
+  if( rc ) goto abort_due_to_error;
+  if( db->xUpdateCallback && op ){
+    db->xUpdateCallback(db->pUpdateArg, op, zDb, pTab->zName, x.nKey);
   }
   break;
 }
 
-/* Opcode: Delete P1 P2 * P4 *
+/* Opcode: Delete P1 P2 P3 P4 P5
 **
 ** Delete the record at which the P1 cursor is currently pointing.
 **
-** The cursor will be left pointing at either the next or the previous
+** If the OPFLAG_SAVEPOSITION bit of the P5 parameter is set, then
+** the cursor will be left pointing at  either the next or the previous
 ** record in the table. If it is left pointing at the next record, then
-** the next Next instruction will be a no-op.  Hence it is OK to delete
-** a record from within an Next loop.
+** the next Next instruction will be a no-op. As a result, in this case
+** it is ok to delete a record from within a Next loop. If 
+** OPFLAG_SAVEPOSITION bit of P5 is clear, then the cursor will be
+** left in an undefined state.
 **
-** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
-** incremented (otherwise not).
+** If the OPFLAG_AUXDELETE bit is set on P5, that indicates that this
+** delete one of several associated with deleting a table row and all its
+** associated index entries.  Exactly one of those deletes is the "primary"
+** delete.  The others are all on OPFLAG_FORDELETE cursors or else are
+** marked with the AUXDELETE flag.
+**
+** If the OPFLAG_NCHANGE flag of P2 (NB: P2 not P5) is set, then the row
+** change count is incremented (otherwise not).
 **
 ** P1 must not be pseudo-table.  It has to be a real table with
 ** multiple rows.
 **
-** If P4 is not NULL, then it is the name of the table that P1 is
-** pointing to.  The update hook will be invoked, if it exists.
-** If P4 is not NULL then the P1 cursor must have been positioned
-** using OP_NotFound prior to invoking this opcode.
+** If P4 is not NULL then it points to a Table struture. In this case either 
+** the update or pre-update hook, or both, may be invoked. The P1 cursor must
+** have been positioned using OP_NotFound prior to invoking this opcode in 
+** this case. Specifically, if one is configured, the pre-update hook is 
+** invoked if P4 is not NULL. The update-hook is invoked if one is configured, 
+** P4 is not NULL, and the OPFLAG_NCHANGE flag is set in P2.
+**
+** If the OPFLAG_ISUPDATE flag is set in P2, then P3 contains the address
+** of the memory cell that contains the value that the rowid of the row will
+** be set to by the update.
 */
 case OP_Delete: {
-#if 0  /* local variables moved into u.bh */
-  i64 iKey;
   VdbeCursor *pC;
-#endif /* local variables moved into u.bh */
+  const char *zDb;
+  Table *pTab;
+  int opflags;
 
-  u.bh.iKey = 0;
+  opflags = pOp->p2;
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bh.pC = p->apCsr[pOp->p1];
-  assert( u.bh.pC!=0 );
-  assert( u.bh.pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  assert( pC->deferredMoveto==0 );
 
-  /* If the update-hook will be invoked, set u.bh.iKey to the rowid of the
-  ** row being deleted.
-  */
-  if( db->xUpdateCallback && pOp->p4.z ){
-    assert( u.bh.pC->isTable );
-    assert( u.bh.pC->rowidIsValid );  /* lastRowid set by previous OP_NotFound */
-    u.bh.iKey = u.bh.pC->lastRowid;
+#ifdef SQLITE_DEBUG
+  if( pOp->p4type==P4_TABLE && HasRowid(pOp->p4.pTab) && pOp->p5==0 ){
+    /* If p5 is zero, the seek operation that positioned the cursor prior to
+    ** OP_Delete will have also set the pC->movetoTarget field to the rowid of
+    ** the row that is being deleted */
+    i64 iKey = sqlite3BtreeIntegerKey(pC->uc.pCursor);
+    assert( pC->movetoTarget==iKey );
+  }
+#endif
+
+  /* If the update-hook or pre-update-hook will be invoked, set zDb to
+  ** the name of the db to pass as to it. Also set local pTab to a copy
+  ** of p4.pTab. Finally, if p5 is true, indicating that this cursor was
+  ** last moved with OP_Next or OP_Prev, not Seek or NotFound, set 
+  ** VdbeCursor.movetoTarget to the current rowid.  */
+  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
+    assert( pC->iDb>=0 );
+    assert( pOp->p4.pTab!=0 );
+    zDb = db->aDb[pC->iDb].zName;
+    pTab = pOp->p4.pTab;
+    if( (pOp->p5 & OPFLAG_SAVEPOSITION)!=0 && pC->isTable ){
+      pC->movetoTarget = sqlite3BtreeIntegerKey(pC->uc.pCursor);
+    }
+  }else{
+    zDb = 0;   /* Not needed.  Silence a compiler warning. */
+    pTab = 0;  /* Not needed.  Silence a compiler warning. */
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update-hook if required. */
+  if( db->xPreUpdateCallback && pOp->p4.pTab && HasRowid(pTab) ){
+    assert( !(opflags & OPFLAG_ISUPDATE) || (aMem[pOp->p3].flags & MEM_Int) );
+    sqlite3VdbePreUpdateHook(p, pC,
+        (opflags & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_DELETE, 
+        zDb, pTab, pC->movetoTarget,
+        pOp->p3
+    );
   }
+  if( opflags & OPFLAG_ISNOOP ) break;
+#endif
+ 
+  /* Only flags that can be set are SAVEPOISTION and AUXDELETE */ 
+  assert( (pOp->p5 & ~(OPFLAG_SAVEPOSITION|OPFLAG_AUXDELETE))==0 );
+  assert( OPFLAG_SAVEPOSITION==BTREE_SAVEPOSITION );
+  assert( OPFLAG_AUXDELETE==BTREE_AUXDELETE );
 
-  /* The OP_Delete opcode always follows an OP_NotExists or OP_Last or
-  ** OP_Column on the same table without any intervening operations that
-  ** might move or invalidate the cursor.  Hence cursor u.bh.pC is always pointing
-  ** to the row to be deleted and the sqlite3VdbeCursorMoveto() operation
-  ** below is always a no-op and cannot fail.  We will run it anyhow, though,
-  ** to guard against future changes to the code generator.
-  **/
-  assert( u.bh.pC->deferredMoveto==0 );
-  rc = sqlite3VdbeCursorMoveto(u.bh.pC);
-  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
+#ifdef SQLITE_DEBUG
+  if( p->pFrame==0 ){
+    if( pC->isEphemeral==0
+        && (pOp->p5 & OPFLAG_AUXDELETE)==0
+        && (pC->wrFlag & OPFLAG_FORDELETE)==0
+      ){
+      nExtraDelete++;
+    }
+    if( pOp->p2 & OPFLAG_NCHANGE ){
+      nExtraDelete--;
+    }
+  }
+#endif
 
-  sqlite3BtreeSetCachedRowid(u.bh.pC->pCursor, 0);
-  rc = sqlite3BtreeDelete(u.bh.pC->pCursor);
-  u.bh.pC->cacheStatus = CACHE_STALE;
+  rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);
+  pC->cacheStatus = CACHE_STALE;
+  if( rc ) goto abort_due_to_error;
 
   /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
-    const char *zDb = db->aDb[u.bh.pC->iDb].zName;
-    const char *zTbl = pOp->p4.z;
-    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, u.bh.iKey);
-    assert( u.bh.pC->iDb>=0 );
+  if( opflags & OPFLAG_NCHANGE ){
+    p->nChange++;
+    if( db->xUpdateCallback && HasRowid(pTab) ){
+      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,
+          pC->movetoTarget);
+      assert( pC->iDb>=0 );
+    }
   }
-  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
+
   break;
 }
 /* Opcode: ResetCount * * * * *
@@ -67565,50 +81662,67 @@ case OP_ResetCount: {
   break;
 }
 
-/* Opcode: SorterCompare P1 P2 P3
+/* Opcode: SorterCompare P1 P2 P3 P4
+** Synopsis:  if key(P1)!=trim(r[P3],P4) goto P2
+**
+** P1 is a sorter cursor. This instruction compares a prefix of the
+** record blob in register P3 against a prefix of the entry that 
+** the sorter cursor currently points to.  Only the first P4 fields
+** of r[P3] and the sorter record are compared.
+**
+** If either P3 or the sorter contains a NULL in one of their significant
+** fields (not counting the P4 fields at the end which are ignored) then
+** the comparison is assumed to be equal.
 **
-** P1 is a sorter cursor. This instruction compares the record blob in 
-** register P3 with the entry that the sorter cursor currently points to.
-** If, excluding the rowid fields at the end, the two records are a match,
-** fall through to the next instruction. Otherwise, jump to instruction P2.
+** Fall through to next instruction if the two records compare equal to
+** each other.  Jump to P2 if they are different.
 */
 case OP_SorterCompare: {
-#if 0  /* local variables moved into u.bi */
   VdbeCursor *pC;
   int res;
-#endif /* local variables moved into u.bi */
+  int nKeyCol;
 
-  u.bi.pC = p->apCsr[pOp->p1];
-  assert( isSorter(u.bi.pC) );
+  pC = p->apCsr[pOp->p1];
+  assert( isSorter(pC) );
+  assert( pOp->p4type==P4_INT32 );
   pIn3 = &aMem[pOp->p3];
-  rc = sqlite3VdbeSorterCompare(u.bi.pC, pIn3, &u.bi.res);
-  if( u.bi.res ){
-    pc = pOp->p2-1;
-  }
+  nKeyCol = pOp->p4.i;
+  res = 0;
+  rc = sqlite3VdbeSorterCompare(pC, pIn3, nKeyCol, &res);
+  VdbeBranchTaken(res!=0,2);
+  if( rc ) goto abort_due_to_error;
+  if( res ) goto jump_to_p2;
   break;
 };
 
-/* Opcode: SorterData P1 P2 * * *
+/* Opcode: SorterData P1 P2 P3 * *
+** Synopsis: r[P2]=data
 **
 ** Write into register P2 the current sorter data for sorter cursor P1.
+** Then clear the column header cache on cursor P3.
+**
+** This opcode is normally use to move a record out of the sorter and into
+** a register that is the source for a pseudo-table cursor created using
+** OpenPseudo.  That pseudo-table cursor is the one that is identified by
+** parameter P3.  Clearing the P3 column cache as part of this opcode saves
+** us from having to issue a separate NullRow instruction to clear that cache.
 */
 case OP_SorterData: {
-#if 0  /* local variables moved into u.bj */
   VdbeCursor *pC;
-#endif /* local variables moved into u.bj */
-#ifndef SQLITE_OMIT_MERGE_SORT
+
   pOut = &aMem[pOp->p2];
-  u.bj.pC = p->apCsr[pOp->p1];
-  assert( u.bj.pC->isSorter );
-  rc = sqlite3VdbeSorterRowkey(u.bj.pC, pOut);
-#else
-  pOp->opcode = OP_RowKey;
-  pc--;
-#endif
+  pC = p->apCsr[pOp->p1];
+  assert( isSorter(pC) );
+  rc = sqlite3VdbeSorterRowkey(pC, pOut);
+  assert( rc!=SQLITE_OK || (pOut->flags & MEM_Blob) );
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  if( rc ) goto abort_due_to_error;
+  p->apCsr[pOp->p3]->cacheStatus = CACHE_STALE;
   break;
 }
 
 /* Opcode: RowData P1 P2 * * *
+** Synopsis: r[P2]=data
 **
 ** Write into register P2 the complete row data for cursor P1.
 ** There is no interpretation of the data.  
@@ -67619,10 +81733,11 @@ case OP_SorterData: {
 ** of a real table, not a pseudo-table.
 */
 /* Opcode: RowKey P1 P2 * * *
+** Synopsis: r[P2]=key
 **
 ** Write into register P2 the complete row key for cursor P1.
 ** There is no interpretation of the data.  
-** The key is copied onto the P3 register exactly as 
+** The key is copied onto the P2 register exactly as 
 ** it is found in the database file.
 **
 ** If the P1 cursor must be pointing to a valid row (not a NULL row)
@@ -67630,70 +81745,64 @@ case OP_SorterData: {
 */
 case OP_RowKey:
 case OP_RowData: {
-#if 0  /* local variables moved into u.bk */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   u32 n;
-  i64 n64;
-#endif /* local variables moved into u.bk */
 
   pOut = &aMem[pOp->p2];
   memAboutToChange(p, pOut);
 
   /* Note that RowKey and RowData are really exactly the same instruction */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bk.pC = p->apCsr[pOp->p1];
-  assert( u.bk.pC->isSorter==0 );
-  assert( u.bk.pC->isTable || pOp->opcode!=OP_RowData );
-  assert( u.bk.pC->isIndex || pOp->opcode==OP_RowData );
-  assert( u.bk.pC!=0 );
-  assert( u.bk.pC->nullRow==0 );
-  assert( u.bk.pC->pseudoTableReg==0 );
-  assert( !u.bk.pC->isSorter );
-  assert( u.bk.pC->pCursor!=0 );
-  u.bk.pCrsr = u.bk.pC->pCursor;
-  assert( sqlite3BtreeCursorIsValid(u.bk.pCrsr) );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( isSorter(pC)==0 );
+  assert( pC->isTable || pOp->opcode!=OP_RowData );
+  assert( pC->isTable==0 || pOp->opcode==OP_RowData );
+  assert( pC->nullRow==0 );
+  assert( pC->uc.pCursor!=0 );
+  pCrsr = pC->uc.pCursor;
 
   /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
-  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
-  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always
-  ** a no-op and can never fail.  But we leave it in place as a safety.
-  */
-  assert( u.bk.pC->deferredMoveto==0 );
-  rc = sqlite3VdbeCursorMoveto(u.bk.pC);
-  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
-
-  if( u.bk.pC->isIndex ){
-    assert( !u.bk.pC->isTable );
-    VVA_ONLY(rc =) sqlite3BtreeKeySize(u.bk.pCrsr, &u.bk.n64);
-    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
-    if( u.bk.n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
-      goto too_big;
-    }
-    u.bk.n = (u32)u.bk.n64;
-  }else{
-    VVA_ONLY(rc =) sqlite3BtreeDataSize(u.bk.pCrsr, &u.bk.n);
-    assert( rc==SQLITE_OK );    /* DataSize() cannot fail */
-    if( u.bk.n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-      goto too_big;
-    }
+  ** OP_SeekRowid or OP_Rewind/Op_Next with no intervening instructions
+  ** that might invalidate the cursor.
+  ** If this where not the case, on of the following assert()s
+  ** would fail.  Should this ever change (because of changes in the code
+  ** generator) then the fix would be to insert a call to
+  ** sqlite3VdbeCursorMoveto().
+  */
+  assert( pC->deferredMoveto==0 );
+  assert( sqlite3BtreeCursorIsValid(pCrsr) );
+#if 0  /* Not required due to the previous to assert() statements */
+  rc = sqlite3VdbeCursorMoveto(pC);
+  if( rc!=SQLITE_OK ) goto abort_due_to_error;
+#endif
+
+  n = sqlite3BtreePayloadSize(pCrsr);
+  if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+    goto too_big;
   }
-  if( sqlite3VdbeMemGrow(pOut, u.bk.n, 0) ){
+  testcase( n==0 );
+  if( sqlite3VdbeMemClearAndResize(pOut, MAX(n,32)) ){
     goto no_mem;
   }
-  pOut->n = u.bk.n;
+  pOut->n = n;
   MemSetTypeFlag(pOut, MEM_Blob);
-  if( u.bk.pC->isIndex ){
-    rc = sqlite3BtreeKey(u.bk.pCrsr, 0, u.bk.n, pOut->z);
+  if( pC->isTable==0 ){
+    rc = sqlite3BtreeKey(pCrsr, 0, n, pOut->z);
   }else{
-    rc = sqlite3BtreeData(u.bk.pCrsr, 0, u.bk.n, pOut->z);
+    rc = sqlite3BtreeData(pCrsr, 0, n, pOut->z);
   }
+  if( rc ) goto abort_due_to_error;
   pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
   UPDATE_MAX_BLOBSIZE(pOut);
+  REGISTER_TRACE(pOp->p2, pOut);
   break;
 }
 
 /* Opcode: Rowid P1 P2 * * *
+** Synopsis: r[P2]=rowid
 **
 ** Store in register P2 an integer which is the key of the table entry that
 ** P1 is currently point to.
@@ -67702,43 +81811,44 @@ case OP_RowData: {
 ** be a separate OP_VRowid opcode for use with virtual tables, but this
 ** one opcode now works for both table types.
 */
-case OP_Rowid: {                 /* out2-prerelease */
-#if 0  /* local variables moved into u.bl */
+case OP_Rowid: {                 /* out2 */
   VdbeCursor *pC;
   i64 v;
   sqlite3_vtab *pVtab;
   const sqlite3_module *pModule;
-#endif /* local variables moved into u.bl */
 
+  pOut = out2Prerelease(p, pOp);
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bl.pC = p->apCsr[pOp->p1];
-  assert( u.bl.pC!=0 );
-  assert( u.bl.pC->pseudoTableReg==0 );
-  if( u.bl.pC->nullRow ){
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );
+  if( pC->nullRow ){
     pOut->flags = MEM_Null;
     break;
-  }else if( u.bl.pC->deferredMoveto ){
-    u.bl.v = u.bl.pC->movetoTarget;
+  }else if( pC->deferredMoveto ){
+    v = pC->movetoTarget;
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  }else if( u.bl.pC->pVtabCursor ){
-    u.bl.pVtab = u.bl.pC->pVtabCursor->pVtab;
-    u.bl.pModule = u.bl.pVtab->pModule;
-    assert( u.bl.pModule->xRowid );
-    rc = u.bl.pModule->xRowid(u.bl.pC->pVtabCursor, &u.bl.v);
-    importVtabErrMsg(p, u.bl.pVtab);
+  }else if( pC->eCurType==CURTYPE_VTAB ){
+    assert( pC->uc.pVCur!=0 );
+    pVtab = pC->uc.pVCur->pVtab;
+    pModule = pVtab->pModule;
+    assert( pModule->xRowid );
+    rc = pModule->xRowid(pC->uc.pVCur, &v);
+    sqlite3VtabImportErrmsg(p, pVtab);
+    if( rc ) goto abort_due_to_error;
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
   }else{
-    assert( u.bl.pC->pCursor!=0 );
-    rc = sqlite3VdbeCursorMoveto(u.bl.pC);
+    assert( pC->eCurType==CURTYPE_BTREE );
+    assert( pC->uc.pCursor!=0 );
+    rc = sqlite3VdbeCursorRestore(pC);
     if( rc ) goto abort_due_to_error;
-    if( u.bl.pC->rowidIsValid ){
-      u.bl.v = u.bl.pC->lastRowid;
-    }else{
-      rc = sqlite3BtreeKeySize(u.bl.pC->pCursor, &u.bl.v);
-      assert( rc==SQLITE_OK );  /* Always so because of CursorMoveto() above */
+    if( pC->nullRow ){
+      pOut->flags = MEM_Null;
+      break;
     }
+    v = sqlite3BtreeIntegerKey(pC->uc.pCursor);
   }
-  pOut->u.i = u.bl.v;
+  pOut->u.i = v;
   break;
 }
 
@@ -67749,51 +81859,56 @@ case OP_Rowid: {                 /* out2-prerelease */
 ** write a NULL.
 */
 case OP_NullRow: {
-#if 0  /* local variables moved into u.bm */
   VdbeCursor *pC;
-#endif /* local variables moved into u.bm */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bm.pC = p->apCsr[pOp->p1];
-  assert( u.bm.pC!=0 );
-  u.bm.pC->nullRow = 1;
-  u.bm.pC->rowidIsValid = 0;
-  assert( u.bm.pC->pCursor || u.bm.pC->pVtabCursor );
-  if( u.bm.pC->pCursor ){
-    sqlite3BtreeClearCursor(u.bm.pC->pCursor);
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  pC->nullRow = 1;
+  pC->cacheStatus = CACHE_STALE;
+  if( pC->eCurType==CURTYPE_BTREE ){
+    assert( pC->uc.pCursor!=0 );
+    sqlite3BtreeClearCursor(pC->uc.pCursor);
   }
   break;
 }
 
-/* Opcode: Last P1 P2 * * *
+/* Opcode: Last P1 P2 P3 * *
 **
-** The next use of the Rowid or Column or Next instruction for P1 
+** The next use of the Rowid or Column or Prev instruction for P1 
 ** will refer to the last entry in the database table or index.
 ** If the table or index is empty and P2>0, then jump immediately to P2.
 ** If P2 is 0 or if the table or index is not empty, fall through
 ** to the following instruction.
+**
+** This opcode leaves the cursor configured to move in reverse order,
+** from the end toward the beginning.  In other words, the cursor is
+** configured to use Prev, not Next.
 */
 case OP_Last: {        /* jump */
-#if 0  /* local variables moved into u.bn */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
-#endif /* local variables moved into u.bn */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bn.pC = p->apCsr[pOp->p1];
-  assert( u.bn.pC!=0 );
-  u.bn.pCrsr = u.bn.pC->pCursor;
-  u.bn.res = 0;
-  if( ALWAYS(u.bn.pCrsr!=0) ){
-    rc = sqlite3BtreeLast(u.bn.pCrsr, &u.bn.res);
-  }
-  u.bn.pC->nullRow = (u8)u.bn.res;
-  u.bn.pC->deferredMoveto = 0;
-  u.bn.pC->rowidIsValid = 0;
-  u.bn.pC->cacheStatus = CACHE_STALE;
-  if( pOp->p2>0 && u.bn.res ){
-    pc = pOp->p2 - 1;
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
+  res = 0;
+  assert( pCrsr!=0 );
+  rc = sqlite3BtreeLast(pCrsr, &res);
+  pC->nullRow = (u8)res;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
+  pC->seekResult = pOp->p3;
+#ifdef SQLITE_DEBUG
+  pC->seekOp = OP_Last;
+#endif
+  if( rc ) goto abort_due_to_error;
+  if( pOp->p2>0 ){
+    VdbeBranchTaken(res!=0,2);
+    if( res ) goto jump_to_p2;
   }
   break;
 }
@@ -67812,64 +81927,75 @@ case OP_Last: {        /* jump */
 ** correctly optimizing out sorts.
 */
 case OP_SorterSort:    /* jump */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_Sort;
-#endif
 case OP_Sort: {        /* jump */
 #ifdef SQLITE_TEST
   sqlite3_sort_count++;
   sqlite3_search_count--;
 #endif
-  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
+  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
   /* Fall through into OP_Rewind */
 }
 /* Opcode: Rewind P1 P2 * * *
 **
 ** The next use of the Rowid or Column or Next instruction for P1 
 ** will refer to the first entry in the database table or index.
-** If the table or index is empty and P2>0, then jump immediately to P2.
-** If P2 is 0 or if the table or index is not empty, fall through
-** to the following instruction.
+** If the table or index is empty, jump immediately to P2.
+** If the table or index is not empty, fall through to the following 
+** instruction.
+**
+** This opcode leaves the cursor configured to move in forward order,
+** from the beginning toward the end.  In other words, the cursor is
+** configured to use Next, not Prev.
 */
 case OP_Rewind: {        /* jump */
-#if 0  /* local variables moved into u.bo */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
-#endif /* local variables moved into u.bo */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bo.pC = p->apCsr[pOp->p1];
-  assert( u.bo.pC!=0 );
-  assert( u.bo.pC->isSorter==(pOp->opcode==OP_SorterSort) );
-  u.bo.res = 1;
-  if( isSorter(u.bo.pC) ){
-    rc = sqlite3VdbeSorterRewind(db, u.bo.pC, &u.bo.res);
-  }else{
-    u.bo.pCrsr = u.bo.pC->pCursor;
-    assert( u.bo.pCrsr );
-    rc = sqlite3BtreeFirst(u.bo.pCrsr, &u.bo.res);
-    u.bo.pC->atFirst = u.bo.res==0 ?1:0;
-    u.bo.pC->deferredMoveto = 0;
-    u.bo.pC->cacheStatus = CACHE_STALE;
-    u.bo.pC->rowidIsValid = 0;
-  }
-  u.bo.pC->nullRow = (u8)u.bo.res;
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( isSorter(pC)==(pOp->opcode==OP_SorterSort) );
+  res = 1;
+#ifdef SQLITE_DEBUG
+  pC->seekOp = OP_Rewind;
+#endif
+  if( isSorter(pC) ){
+    rc = sqlite3VdbeSorterRewind(pC, &res);
+  }else{
+    assert( pC->eCurType==CURTYPE_BTREE );
+    pCrsr = pC->uc.pCursor;
+    assert( pCrsr );
+    rc = sqlite3BtreeFirst(pCrsr, &res);
+    pC->deferredMoveto = 0;
+    pC->cacheStatus = CACHE_STALE;
+  }
+  if( rc ) goto abort_due_to_error;
+  pC->nullRow = (u8)res;
   assert( pOp->p2>0 && pOp->p2<p->nOp );
-  if( u.bo.res ){
-    pc = pOp->p2 - 1;
-  }
+  VdbeBranchTaken(res!=0,2);
+  if( res ) goto jump_to_p2;
   break;
 }
 
-/* Opcode: Next P1 P2 * P4 P5
+/* Opcode: Next P1 P2 P3 P4 P5
 **
 ** Advance cursor P1 so that it points to the next key/data pair in its
 ** table or index.  If there are no more key/value pairs then fall through
 ** to the following instruction.  But if the cursor advance was successful,
 ** jump immediately to P2.
 **
-** The P1 cursor must be for a real table, not a pseudo-table.
+** The Next opcode is only valid following an SeekGT, SeekGE, or
+** OP_Rewind opcode used to position the cursor.  Next is not allowed
+** to follow SeekLT, SeekLE, or OP_Last.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.  P1 must have
+** been opened prior to this opcode or the program will segfault.
+**
+** The P3 value is a hint to the btree implementation. If P3==1, that
+** means P1 is an SQL index and that this instruction could have been
+** omitted if that index had been unique.  P3 is usually 0.  P3 is
+** always either 0 or 1.
 **
 ** P4 is always of type P4_ADVANCE. The function pointer points to
 ** sqlite3BtreeNext().
@@ -67877,16 +82003,32 @@ case OP_Rewind: {        /* jump */
 ** If P5 is positive and the jump is taken, then event counter
 ** number P5-1 in the prepared statement is incremented.
 **
-** See also: Prev
+** See also: Prev, NextIfOpen
+*/
+/* Opcode: NextIfOpen P1 P2 P3 P4 P5
+**
+** This opcode works just like Next except that if cursor P1 is not
+** open it behaves a no-op.
 */
-/* Opcode: Prev P1 P2 * * P5
+/* Opcode: Prev P1 P2 P3 P4 P5
 **
 ** Back up cursor P1 so that it points to the previous key/data pair in its
 ** table or index.  If there is no previous key/value pairs then fall through
 ** to the following instruction.  But if the cursor backup was successful,
 ** jump immediately to P2.
 **
-** The P1 cursor must be for a real table, not a pseudo-table.
+**
+** The Prev opcode is only valid following an SeekLT, SeekLE, or
+** OP_Last opcode used to position the cursor.  Prev is not allowed
+** to follow SeekGT, SeekGE, or OP_Rewind.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.  If P1 is
+** not open then the behavior is undefined.
+**
+** The P3 value is a hint to the btree implementation. If P3==1, that
+** means P1 is an SQL index and that this instruction could have been
+** omitted if that index had been unique.  P3 is usually 0.  P3 is
+** always either 0 or 1.
 **
 ** P4 is always of type P4_ADVANCE. The function pointer points to
 ** sqlite3BtreePrevious().
@@ -67894,50 +82036,69 @@ case OP_Rewind: {        /* jump */
 ** If P5 is positive and the jump is taken, then event counter
 ** number P5-1 in the prepared statement is incremented.
 */
-case OP_SorterNext:    /* jump */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_Next;
-#endif
-case OP_Prev:          /* jump */
-case OP_Next: {        /* jump */
-#if 0  /* local variables moved into u.bp */
+/* Opcode: PrevIfOpen P1 P2 P3 P4 P5
+**
+** This opcode works just like Prev except that if cursor P1 is not
+** open it behaves a no-op.
+*/
+case OP_SorterNext: {  /* jump */
   VdbeCursor *pC;
   int res;
-#endif /* local variables moved into u.bp */
 
-  CHECK_FOR_INTERRUPT;
+  pC = p->apCsr[pOp->p1];
+  assert( isSorter(pC) );
+  res = 0;
+  rc = sqlite3VdbeSorterNext(db, pC, &res);
+  goto next_tail;
+case OP_PrevIfOpen:    /* jump */
+case OP_NextIfOpen:    /* jump */
+  if( p->apCsr[pOp->p1]==0 ) break;
+  /* Fall through */
+case OP_Prev:          /* jump */
+case OP_Next:          /* jump */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  assert( pOp->p5<=ArraySize(p->aCounter) );
-  u.bp.pC = p->apCsr[pOp->p1];
-  if( u.bp.pC==0 ){
-    break;  /* See ticket #2273 */
-  }
-  assert( u.bp.pC->isSorter==(pOp->opcode==OP_SorterNext) );
-  if( isSorter(u.bp.pC) ){
-    assert( pOp->opcode==OP_SorterNext );
-    rc = sqlite3VdbeSorterNext(db, u.bp.pC, &u.bp.res);
-  }else{
-    u.bp.res = 1;
-    assert( u.bp.pC->deferredMoveto==0 );
-    assert( u.bp.pC->pCursor );
-    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
-    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
-    rc = pOp->p4.xAdvance(u.bp.pC->pCursor, &u.bp.res);
-  }
-  u.bp.pC->nullRow = (u8)u.bp.res;
-  u.bp.pC->cacheStatus = CACHE_STALE;
-  if( u.bp.res==0 ){
-    pc = pOp->p2 - 1;
-    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
+  assert( pOp->p5<ArraySize(p->aCounter) );
+  pC = p->apCsr[pOp->p1];
+  res = pOp->p3;
+  assert( pC!=0 );
+  assert( pC->deferredMoveto==0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( res==0 || (res==1 && pC->isTable==0) );
+  testcase( res==1 );
+  assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
+  assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
+  assert( pOp->opcode!=OP_NextIfOpen || pOp->p4.xAdvance==sqlite3BtreeNext );
+  assert( pOp->opcode!=OP_PrevIfOpen || pOp->p4.xAdvance==sqlite3BtreePrevious);
+
+  /* The Next opcode is only used after SeekGT, SeekGE, and Rewind.
+  ** The Prev opcode is only used after SeekLT, SeekLE, and Last. */
+  assert( pOp->opcode!=OP_Next || pOp->opcode!=OP_NextIfOpen
+       || pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE
+       || pC->seekOp==OP_Rewind || pC->seekOp==OP_Found);
+  assert( pOp->opcode!=OP_Prev || pOp->opcode!=OP_PrevIfOpen
+       || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
+       || pC->seekOp==OP_Last );
+
+  rc = pOp->p4.xAdvance(pC->uc.pCursor, &res);
+next_tail:
+  pC->cacheStatus = CACHE_STALE;
+  VdbeBranchTaken(res==0,2);
+  if( rc ) goto abort_due_to_error;
+  if( res==0 ){
+    pC->nullRow = 0;
+    p->aCounter[pOp->p5]++;
 #ifdef SQLITE_TEST
     sqlite3_search_count++;
 #endif
+    goto jump_to_p2_and_check_for_interrupt;
+  }else{
+    pC->nullRow = 1;
   }
-  u.bp.pC->rowidIsValid = 0;
-  break;
+  goto check_for_interrupt;
 }
 
 /* Opcode: IdxInsert P1 P2 P3 * P5
+** Synopsis: key=r[P2]
 **
 ** Register P2 holds an SQL index key made using the
 ** MakeRecord instructions.  This opcode writes that key
@@ -67946,87 +82107,109 @@ case OP_Next: {        /* jump */
 ** P3 is a flag that provides a hint to the b-tree layer that this
 ** insert is likely to be an append.
 **
+** If P5 has the OPFLAG_NCHANGE bit set, then the change counter is
+** incremented by this instruction.  If the OPFLAG_NCHANGE bit is clear,
+** then the change counter is unchanged.
+**
+** If P5 has the OPFLAG_USESEEKRESULT bit set, then the cursor must have
+** just done a seek to the spot where the new entry is to be inserted.
+** This flag avoids doing an extra seek.
+**
 ** This instruction only works for indices.  The equivalent instruction
 ** for tables is OP_Insert.
 */
 case OP_SorterInsert:       /* in2 */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  pOp->opcode = OP_IdxInsert;
-#endif
 case OP_IdxInsert: {        /* in2 */
-#if 0  /* local variables moved into u.bq */
   VdbeCursor *pC;
-  BtCursor *pCrsr;
-  int nKey;
-  const char *zKey;
-#endif /* local variables moved into u.bq */
+  BtreePayload x;
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bq.pC = p->apCsr[pOp->p1];
-  assert( u.bq.pC!=0 );
-  assert( u.bq.pC->isSorter==(pOp->opcode==OP_SorterInsert) );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );
   pIn2 = &aMem[pOp->p2];
   assert( pIn2->flags & MEM_Blob );
-  u.bq.pCrsr = u.bq.pC->pCursor;
-  if( ALWAYS(u.bq.pCrsr!=0) ){
-    assert( u.bq.pC->isTable==0 );
-    rc = ExpandBlob(pIn2);
-    if( rc==SQLITE_OK ){
-      if( isSorter(u.bq.pC) ){
-        rc = sqlite3VdbeSorterWrite(db, u.bq.pC, pIn2);
-      }else{
-        u.bq.nKey = pIn2->n;
-        u.bq.zKey = pIn2->z;
-        rc = sqlite3BtreeInsert(u.bq.pCrsr, u.bq.zKey, u.bq.nKey, "", 0, 0, pOp->p3,
-            ((pOp->p5 & OPFLAG_USESEEKRESULT) ? u.bq.pC->seekResult : 0)
-            );
-        assert( u.bq.pC->deferredMoveto==0 );
-        u.bq.pC->cacheStatus = CACHE_STALE;
-      }
-    }
+  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
+  assert( pC->eCurType==CURTYPE_BTREE || pOp->opcode==OP_SorterInsert );
+  assert( pC->isTable==0 );
+  rc = ExpandBlob(pIn2);
+  if( rc ) goto abort_due_to_error;
+  if( pOp->opcode==OP_SorterInsert ){
+    rc = sqlite3VdbeSorterWrite(pC, pIn2);
+  }else{
+    x.nKey = pIn2->n;
+    x.pKey = pIn2->z;
+    x.nData = 0;
+    x.nZero = 0;
+    x.pData = 0;
+    rc = sqlite3BtreeInsert(pC->uc.pCursor, &x, pOp->p3, 
+        ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
+        );
+    assert( pC->deferredMoveto==0 );
+    pC->cacheStatus = CACHE_STALE;
   }
+  if( rc) goto abort_due_to_error;
   break;
 }
 
 /* Opcode: IdxDelete P1 P2 P3 * *
+** Synopsis: key=r[P2@P3]
 **
 ** The content of P3 registers starting at register P2 form
 ** an unpacked index key. This opcode removes that entry from the 
 ** index opened by cursor P1.
 */
 case OP_IdxDelete: {
-#if 0  /* local variables moved into u.br */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
   UnpackedRecord r;
-#endif /* local variables moved into u.br */
 
   assert( pOp->p3>0 );
-  assert( pOp->p2>0 && pOp->p2+pOp->p3<=p->nMem+1 );
+  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem+1 - p->nCursor)+1 );
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.br.pC = p->apCsr[pOp->p1];
-  assert( u.br.pC!=0 );
-  u.br.pCrsr = u.br.pC->pCursor;
-  if( ALWAYS(u.br.pCrsr!=0) ){
-    u.br.r.pKeyInfo = u.br.pC->pKeyInfo;
-    u.br.r.nField = (u16)pOp->p3;
-    u.br.r.flags = 0;
-    u.br.r.aMem = &aMem[pOp->p2];
-#ifdef SQLITE_DEBUG
-    { int i; for(i=0; i<u.br.r.nField; i++) assert( memIsValid(&u.br.r.aMem[i]) ); }
-#endif
-    rc = sqlite3BtreeMovetoUnpacked(u.br.pCrsr, &u.br.r, 0, 0, &u.br.res);
-    if( rc==SQLITE_OK && u.br.res==0 ){
-      rc = sqlite3BtreeDelete(u.br.pCrsr);
-    }
-    assert( u.br.pC->deferredMoveto==0 );
-    u.br.pC->cacheStatus = CACHE_STALE;
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  pCrsr = pC->uc.pCursor;
+  assert( pCrsr!=0 );
+  assert( pOp->p5==0 );
+  r.pKeyInfo = pC->pKeyInfo;
+  r.nField = (u16)pOp->p3;
+  r.default_rc = 0;
+  r.aMem = &aMem[pOp->p2];
+  rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
+  if( rc ) goto abort_due_to_error;
+  if( res==0 ){
+    rc = sqlite3BtreeDelete(pCrsr, BTREE_AUXDELETE);
+    if( rc ) goto abort_due_to_error;
   }
+  assert( pC->deferredMoveto==0 );
+  pC->cacheStatus = CACHE_STALE;
   break;
 }
 
+/* Opcode: Seek P1 * P3 P4 *
+** Synopsis:  Move P3 to P1.rowid
+**
+** P1 is an open index cursor and P3 is a cursor on the corresponding
+** table.  This opcode does a deferred seek of the P3 table cursor
+** to the row that corresponds to the current row of P1.
+**
+** This is a deferred seek.  Nothing actually happens until
+** the cursor is used to read a record.  That way, if no reads
+** occur, no unnecessary I/O happens.
+**
+** P4 may be an array of integers (type P4_INTARRAY) containing
+** one entry for each column in the P3 table.  If array entry a(i)
+** is non-zero, then reading column a(i)-1 from cursor P3 is 
+** equivalent to performing the deferred seek and then reading column i 
+** from P1.  This information is stored in P3 and used to redirect
+** reads against P3 over to P1, thus possibly avoiding the need to
+** seek and read cursor P3.
+*/
 /* Opcode: IdxRowid P1 P2 * * *
+** Synopsis: r[P2]=rowid
 **
 ** Write into register P2 an integer which is the last entry in the record at
 ** the end of the index key pointed to by cursor P1.  This integer should be
@@ -68034,99 +82217,148 @@ case OP_IdxDelete: {
 **
 ** See also: Rowid, MakeRecord.
 */
-case OP_IdxRowid: {              /* out2-prerelease */
-#if 0  /* local variables moved into u.bs */
-  BtCursor *pCrsr;
-  VdbeCursor *pC;
-  i64 rowid;
-#endif /* local variables moved into u.bs */
+case OP_Seek:
+case OP_IdxRowid: {              /* out2 */
+  VdbeCursor *pC;                /* The P1 index cursor */
+  VdbeCursor *pTabCur;           /* The P2 table cursor (OP_Seek only) */
+  i64 rowid;                     /* Rowid that P1 current points to */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bs.pC = p->apCsr[pOp->p1];
-  assert( u.bs.pC!=0 );
-  u.bs.pCrsr = u.bs.pC->pCursor;
-  pOut->flags = MEM_Null;
-  if( ALWAYS(u.bs.pCrsr!=0) ){
-    rc = sqlite3VdbeCursorMoveto(u.bs.pC);
-    if( NEVER(rc) ) goto abort_due_to_error;
-    assert( u.bs.pC->deferredMoveto==0 );
-    assert( u.bs.pC->isTable==0 );
-    if( !u.bs.pC->nullRow ){
-      rc = sqlite3VdbeIdxRowid(db, u.bs.pCrsr, &u.bs.rowid);
-      if( rc!=SQLITE_OK ){
-        goto abort_due_to_error;
-      }
-      pOut->u.i = u.bs.rowid;
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0 );
+  assert( pC->isTable==0 );
+  assert( pC->deferredMoveto==0 );
+  assert( !pC->nullRow || pOp->opcode==OP_IdxRowid );
+
+  /* The IdxRowid and Seek opcodes are combined because of the commonality
+  ** of sqlite3VdbeCursorRestore() and sqlite3VdbeIdxRowid(). */
+  rc = sqlite3VdbeCursorRestore(pC);
+
+  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
+  ** out from under the cursor.  That will never happens for an IdxRowid
+  ** or Seek opcode */
+  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
+
+  if( !pC->nullRow ){
+    rowid = 0;  /* Not needed.  Only used to silence a warning. */
+    rc = sqlite3VdbeIdxRowid(db, pC->uc.pCursor, &rowid);
+    if( rc!=SQLITE_OK ){
+      goto abort_due_to_error;
+    }
+    if( pOp->opcode==OP_Seek ){
+      assert( pOp->p3>=0 && pOp->p3<p->nCursor );
+      pTabCur = p->apCsr[pOp->p3];
+      assert( pTabCur!=0 );
+      assert( pTabCur->eCurType==CURTYPE_BTREE );
+      assert( pTabCur->uc.pCursor!=0 );
+      assert( pTabCur->isTable );
+      pTabCur->nullRow = 0;
+      pTabCur->movetoTarget = rowid;
+      pTabCur->deferredMoveto = 1;
+      assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );
+      pTabCur->aAltMap = pOp->p4.ai;
+      pTabCur->pAltCursor = pC;
+    }else{
+      pOut = out2Prerelease(p, pOp);
+      pOut->u.i = rowid;
       pOut->flags = MEM_Int;
     }
+  }else{
+    assert( pOp->opcode==OP_IdxRowid );
+    sqlite3VdbeMemSetNull(&aMem[pOp->p2]);
   }
   break;
 }
 
 /* Opcode: IdxGE P1 P2 P3 P4 P5
+** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
-** key that omits the ROWID.  Compare this key value against the index 
-** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+** key that omits the PRIMARY KEY.  Compare this key value against the index 
+** that P1 is currently pointing to, ignoring the PRIMARY KEY or ROWID 
+** fields at the end.
 **
 ** If the P1 index entry is greater than or equal to the key value
 ** then jump to P2.  Otherwise fall through to the next instruction.
+*/
+/* Opcode: IdxGT P1 P2 P3 P4 P5
+** Synopsis: key=r[P3@P4]
 **
-** If P5 is non-zero then the key value is increased by an epsilon 
-** prior to the comparison.  This make the opcode work like IdxGT except
-** that if the key from register P3 is a prefix of the key in the cursor,
-** the result is false whereas it would be true with IdxGT.
+** The P4 register values beginning with P3 form an unpacked index 
+** key that omits the PRIMARY KEY.  Compare this key value against the index 
+** that P1 is currently pointing to, ignoring the PRIMARY KEY or ROWID 
+** fields at the end.
+**
+** If the P1 index entry is greater than the key value
+** then jump to P2.  Otherwise fall through to the next instruction.
 */
 /* Opcode: IdxLT P1 P2 P3 P4 P5
+** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
-** key that omits the ROWID.  Compare this key value against the index 
-** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+** key that omits the PRIMARY KEY or ROWID.  Compare this key value against
+** the index that P1 is currently pointing to, ignoring the PRIMARY KEY or
+** ROWID on the P1 index.
 **
 ** If the P1 index entry is less than the key value then jump to P2.
 ** Otherwise fall through to the next instruction.
+*/
+/* Opcode: IdxLE P1 P2 P3 P4 P5
+** Synopsis: key=r[P3@P4]
+**
+** The P4 register values beginning with P3 form an unpacked index 
+** key that omits the PRIMARY KEY or ROWID.  Compare this key value against
+** the index that P1 is currently pointing to, ignoring the PRIMARY KEY or
+** ROWID on the P1 index.
 **
-** If P5 is non-zero then the key value is increased by an epsilon prior 
-** to the comparison.  This makes the opcode work like IdxLE.
+** If the P1 index entry is less than or equal to the key value then jump
+** to P2. Otherwise fall through to the next instruction.
 */
+case OP_IdxLE:          /* jump */
+case OP_IdxGT:          /* jump */
 case OP_IdxLT:          /* jump */
-case OP_IdxGE: {        /* jump */
-#if 0  /* local variables moved into u.bt */
+case OP_IdxGE:  {       /* jump */
   VdbeCursor *pC;
   int res;
   UnpackedRecord r;
-#endif /* local variables moved into u.bt */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  u.bt.pC = p->apCsr[pOp->p1];
-  assert( u.bt.pC!=0 );
-  assert( u.bt.pC->isOrdered );
-  if( ALWAYS(u.bt.pC->pCursor!=0) ){
-    assert( u.bt.pC->deferredMoveto==0 );
-    assert( pOp->p5==0 || pOp->p5==1 );
-    assert( pOp->p4type==P4_INT32 );
-    u.bt.r.pKeyInfo = u.bt.pC->pKeyInfo;
-    u.bt.r.nField = (u16)pOp->p4.i;
-    if( pOp->p5 ){
-      u.bt.r.flags = UNPACKED_INCRKEY | UNPACKED_IGNORE_ROWID;
-    }else{
-      u.bt.r.flags = UNPACKED_IGNORE_ROWID;
-    }
-    u.bt.r.aMem = &aMem[pOp->p3];
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  assert( pC->isOrdered );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( pC->uc.pCursor!=0);
+  assert( pC->deferredMoveto==0 );
+  assert( pOp->p5==0 || pOp->p5==1 );
+  assert( pOp->p4type==P4_INT32 );
+  r.pKeyInfo = pC->pKeyInfo;
+  r.nField = (u16)pOp->p4.i;
+  if( pOp->opcode<OP_IdxLT ){
+    assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxGT );
+    r.default_rc = -1;
+  }else{
+    assert( pOp->opcode==OP_IdxGE || pOp->opcode==OP_IdxLT );
+    r.default_rc = 0;
+  }
+  r.aMem = &aMem[pOp->p3];
 #ifdef SQLITE_DEBUG
-    { int i; for(i=0; i<u.bt.r.nField; i++) assert( memIsValid(&u.bt.r.aMem[i]) ); }
-#endif
-    rc = sqlite3VdbeIdxKeyCompare(u.bt.pC, &u.bt.r, &u.bt.res);
-    if( pOp->opcode==OP_IdxLT ){
-      u.bt.res = -u.bt.res;
-    }else{
-      assert( pOp->opcode==OP_IdxGE );
-      u.bt.res++;
-    }
-    if( u.bt.res>0 ){
-      pc = pOp->p2 - 1 ;
-    }
+  { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
+#endif
+  res = 0;  /* Not needed.  Only used to silence a warning. */
+  rc = sqlite3VdbeIdxKeyCompare(db, pC, &r, &res);
+  assert( (OP_IdxLE&1)==(OP_IdxLT&1) && (OP_IdxGE&1)==(OP_IdxGT&1) );
+  if( (pOp->opcode&1)==(OP_IdxLT&1) ){
+    assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxLT );
+    res = -res;
+  }else{
+    assert( pOp->opcode==OP_IdxGE || pOp->opcode==OP_IdxGT );
+    res++;
   }
+  VdbeBranchTaken(res>0,2);
+  if( rc ) goto abort_due_to_error;
+  if( res>0 ) goto jump_to_p2;
   break;
 }
 
@@ -68150,40 +82382,32 @@ case OP_IdxGE: {        /* jump */
 **
 ** See also: Clear
 */
-case OP_Destroy: {     /* out2-prerelease */
-#if 0  /* local variables moved into u.bu */
+case OP_Destroy: {     /* out2 */
   int iMoved;
-  int iCnt;
-  Vdbe *pVdbe;
   int iDb;
-#endif /* local variables moved into u.bu */
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  u.bu.iCnt = 0;
-  for(u.bu.pVdbe=db->pVdbe; u.bu.pVdbe; u.bu.pVdbe = u.bu.pVdbe->pNext){
-    if( u.bu.pVdbe->magic==VDBE_MAGIC_RUN && u.bu.pVdbe->inVtabMethod<2 && u.bu.pVdbe->pc>=0 ){
-      u.bu.iCnt++;
-    }
-  }
-#else
-  u.bu.iCnt = db->activeVdbeCnt;
-#endif
+
+  assert( p->readOnly==0 );
+  assert( pOp->p1>1 );
+  pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Null;
-  if( u.bu.iCnt>1 ){
+  if( db->nVdbeRead > db->nVDestroy+1 ){
     rc = SQLITE_LOCKED;
     p->errorAction = OE_Abort;
+    goto abort_due_to_error;
   }else{
-    u.bu.iDb = pOp->p3;
-    assert( u.bu.iCnt==1 );
-    assert( (p->btreeMask & (((yDbMask)1)<<u.bu.iDb))!=0 );
-    rc = sqlite3BtreeDropTable(db->aDb[u.bu.iDb].pBt, pOp->p1, &u.bu.iMoved);
+    iDb = pOp->p3;
+    assert( DbMaskTest(p->btreeMask, iDb) );
+    iMoved = 0;  /* Not needed.  Only to silence a warning. */
+    rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
     pOut->flags = MEM_Int;
-    pOut->u.i = u.bu.iMoved;
+    pOut->u.i = iMoved;
+    if( rc ) goto abort_due_to_error;
 #ifndef SQLITE_OMIT_AUTOVACUUM
-    if( rc==SQLITE_OK && u.bu.iMoved!=0 ){
-      sqlite3RootPageMoved(db, u.bu.iDb, u.bu.iMoved, pOp->p1);
+    if( iMoved!=0 ){
+      sqlite3RootPageMoved(db, iDb, iMoved, pOp->p1);
       /* All OP_Destroy operations occur on the same btree */
-      assert( resetSchemaOnFault==0 || resetSchemaOnFault==u.bu.iDb+1 );
-      resetSchemaOnFault = u.bu.iDb+1;
+      assert( resetSchemaOnFault==0 || resetSchemaOnFault==iDb+1 );
+      resetSchemaOnFault = iDb+1;
     }
 #endif
   }
@@ -68209,27 +82433,53 @@ case OP_Destroy: {     /* out2-prerelease */
 ** See also: Destroy
 */
 case OP_Clear: {
-#if 0  /* local variables moved into u.bv */
   int nChange;
-#endif /* local variables moved into u.bv */
-
-  u.bv.nChange = 0;
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p2))!=0 );
+ 
+  nChange = 0;
+  assert( p->readOnly==0 );
+  assert( DbMaskTest(p->btreeMask, pOp->p2) );
   rc = sqlite3BtreeClearTable(
-      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &u.bv.nChange : 0)
+      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &nChange : 0)
   );
   if( pOp->p3 ){
-    p->nChange += u.bv.nChange;
+    p->nChange += nChange;
     if( pOp->p3>0 ){
       assert( memIsValid(&aMem[pOp->p3]) );
       memAboutToChange(p, &aMem[pOp->p3]);
-      aMem[pOp->p3].u.i += u.bv.nChange;
+      aMem[pOp->p3].u.i += nChange;
     }
   }
+  if( rc ) goto abort_due_to_error;
+  break;
+}
+
+/* Opcode: ResetSorter P1 * * * *
+**
+** Delete all contents from the ephemeral table or sorter
+** that is open on cursor P1.
+**
+** This opcode only works for cursors used for sorting and
+** opened with OP_OpenEphemeral or OP_SorterOpen.
+*/
+case OP_ResetSorter: {
+  VdbeCursor *pC;
+ 
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  pC = p->apCsr[pOp->p1];
+  assert( pC!=0 );
+  if( isSorter(pC) ){
+    sqlite3VdbeSorterReset(db, pC->uc.pSorter);
+  }else{
+    assert( pC->eCurType==CURTYPE_BTREE );
+    assert( pC->isEphemeral );
+    rc = sqlite3BtreeClearTableOfCursor(pC->uc.pCursor);
+    if( rc ) goto abort_due_to_error;
+  }
   break;
 }
 
 /* Opcode: CreateTable P1 P2 * * *
+** Synopsis: r[P2]=root iDb=P1
 **
 ** Allocate a new table in the main database file if P1==0 or in the
 ** auxiliary database file if P1==1 or in an attached database if
@@ -68243,6 +82493,7 @@ case OP_Clear: {
 ** See also: CreateIndex
 */
 /* Opcode: CreateIndex P1 P2 * * *
+** Synopsis: r[P2]=root iDb=P1
 **
 ** Allocate a new index in the main database file if P1==0 or in the
 ** auxiliary database file if P1==1 or in an attached database if
@@ -68251,27 +82502,28 @@ case OP_Clear: {
 **
 ** See documentation on OP_CreateTable for additional information.
 */
-case OP_CreateIndex:            /* out2-prerelease */
-case OP_CreateTable: {          /* out2-prerelease */
-#if 0  /* local variables moved into u.bw */
+case OP_CreateIndex:            /* out2 */
+case OP_CreateTable: {          /* out2 */
   int pgno;
   int flags;
   Db *pDb;
-#endif /* local variables moved into u.bw */
 
-  u.bw.pgno = 0;
+  pOut = out2Prerelease(p, pOp);
+  pgno = 0;
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
-  u.bw.pDb = &db->aDb[pOp->p1];
-  assert( u.bw.pDb->pBt!=0 );
+  assert( DbMaskTest(p->btreeMask, pOp->p1) );
+  assert( p->readOnly==0 );
+  pDb = &db->aDb[pOp->p1];
+  assert( pDb->pBt!=0 );
   if( pOp->opcode==OP_CreateTable ){
-    /* u.bw.flags = BTREE_INTKEY; */
-    u.bw.flags = BTREE_INTKEY;
+    /* flags = BTREE_INTKEY; */
+    flags = BTREE_INTKEY;
   }else{
-    u.bw.flags = BTREE_BLOBKEY;
+    flags = BTREE_BLOBKEY;
   }
-  rc = sqlite3BtreeCreateTable(u.bw.pDb->pBt, &u.bw.pgno, u.bw.flags);
-  pOut->u.i = u.bw.pgno;
+  rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
+  if( rc ) goto abort_due_to_error;
+  pOut->u.i = pgno;
   break;
 }
 
@@ -68284,51 +82536,53 @@ case OP_CreateTable: {          /* out2-prerelease */
 ** then runs the new virtual machine.  It is thus a re-entrant opcode.
 */
 case OP_ParseSchema: {
-#if 0  /* local variables moved into u.bx */
   int iDb;
   const char *zMaster;
   char *zSql;
   InitData initData;
-#endif /* local variables moved into u.bx */
 
   /* Any prepared statement that invokes this opcode will hold mutexes
-  ** on every btree.  This is a prerequisite for invoking
+  ** on every btree.  This is a prerequisite for invoking 
   ** sqlite3InitCallback().
   */
 #ifdef SQLITE_DEBUG
-  for(u.bx.iDb=0; u.bx.iDb<db->nDb; u.bx.iDb++){
-    assert( u.bx.iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[u.bx.iDb].pBt) );
+  for(iDb=0; iDb<db->nDb; iDb++){
+    assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
   }
 #endif
 
-  u.bx.iDb = pOp->p1;
-  assert( u.bx.iDb>=0 && u.bx.iDb<db->nDb );
-  assert( DbHasProperty(db, u.bx.iDb, DB_SchemaLoaded) );
+  iDb = pOp->p1;
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( DbHasProperty(db, iDb, DB_SchemaLoaded) );
   /* Used to be a conditional */ {
-    u.bx.zMaster = SCHEMA_TABLE(u.bx.iDb);
-    u.bx.initData.db = db;
-    u.bx.initData.iDb = pOp->p1;
-    u.bx.initData.pzErrMsg = &p->zErrMsg;
-    u.bx.zSql = sqlite3MPrintf(db,
+    zMaster = SCHEMA_TABLE(iDb);
+    initData.db = db;
+    initData.iDb = pOp->p1;
+    initData.pzErrMsg = &p->zErrMsg;
+    zSql = sqlite3MPrintf(db,
        "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
-       db->aDb[u.bx.iDb].zName, u.bx.zMaster, pOp->p4.z);
-    if( u.bx.zSql==0 ){
-      rc = SQLITE_NOMEM;
+       db->aDb[iDb].zName, zMaster, pOp->p4.z);
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM_BKPT;
     }else{
       assert( db->init.busy==0 );
       db->init.busy = 1;
-      u.bx.initData.rc = SQLITE_OK;
+      initData.rc = SQLITE_OK;
       assert( !db->mallocFailed );
-      rc = sqlite3_exec(db, u.bx.zSql, sqlite3InitCallback, &u.bx.initData, 0);
-      if( rc==SQLITE_OK ) rc = u.bx.initData.rc;
-      sqlite3DbFree(db, u.bx.zSql);
+      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+      if( rc==SQLITE_OK ) rc = initData.rc;
+      sqlite3DbFree(db, zSql);
       db->init.busy = 0;
     }
   }
-  if( rc==SQLITE_NOMEM ){
-    goto no_mem;
+  if( rc ){
+    sqlite3ResetAllSchemasOfConnection(db);
+    if( rc==SQLITE_NOMEM ){
+      goto no_mem;
+    }
+    goto abort_due_to_error;
   }
-  break;
+  break;  
 }
 
 #if !defined(SQLITE_OMIT_ANALYZE)
@@ -68341,6 +82595,7 @@ case OP_ParseSchema: {
 case OP_LoadAnalysis: {
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   rc = sqlite3AnalysisLoad(db, pOp->p1);
+  if( rc ) goto abort_due_to_error;
   break;  
 }
 #endif /* !defined(SQLITE_OMIT_ANALYZE) */
@@ -68349,7 +82604,8 @@ case OP_LoadAnalysis: {
 **
 ** Remove the internal (in-memory) data structures that describe
 ** the table named P4 in database P1.  This is called after a table
-** is dropped in order to keep the internal representation of the
+** is dropped from disk (using the Destroy opcode) in order to keep 
+** the internal representation of the
 ** schema consistent with what is on disk.
 */
 case OP_DropTable: {
@@ -68361,7 +82617,8 @@ case OP_DropTable: {
 **
 ** Remove the internal (in-memory) data structures that describe
 ** the index named P4 in database P1.  This is called after an index
-** is dropped in order to keep the internal representation of the
+** is dropped from disk (using the Destroy opcode)
+** in order to keep the internal representation of the
 ** schema consistent with what is on disk.
 */
 case OP_DropIndex: {
@@ -68373,7 +82630,8 @@ case OP_DropIndex: {
 **
 ** Remove the internal (in-memory) data structures that describe
 ** the trigger named P4 in database P1.  This is called after a trigger
-** is dropped in order to keep the internal representation of the
+** is dropped from disk (using the Destroy opcode) in order to keep 
+** the internal representation of the
 ** schema consistent with what is on disk.
 */
 case OP_DropTrigger: {
@@ -68383,7 +82641,7 @@ case OP_DropTrigger: {
 
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
-/* Opcode: IntegrityCk P1 P2 P3 * P5
+/* Opcode: IntegrityCk P1 P2 P3 P4 P5
 **
 ** Do an analysis of the currently open database.  Store in
 ** register P1 the text of an error message describing any problems.
@@ -68394,9 +82652,8 @@ case OP_DropTrigger: {
 ** In other words, the analysis stops as soon as reg(P1) errors are 
 ** seen.  Reg(P1) is updated with the number of errors remaining.
 **
-** The root page numbers of all tables in the database are integer
-** stored in reg(P1), reg(P1+1), reg(P1+2), ....  There are P2 tables
-** total.
+** The root page numbers of all tables in the database are integers
+** stored in P4_INTARRAY argument.
 **
 ** If P5 is not zero, the check is done on the auxiliary database
 ** file, not the main database file.
@@ -68404,41 +82661,34 @@ case OP_DropTrigger: {
 ** This opcode is used to implement the integrity_check pragma.
 */
 case OP_IntegrityCk: {
-#if 0  /* local variables moved into u.by */
   int nRoot;      /* Number of tables to check.  (Number of root pages.) */
   int *aRoot;     /* Array of rootpage numbers for tables to be checked */
-  int j;          /* Loop counter */
   int nErr;       /* Number of errors reported */
   char *z;        /* Text of the error report */
   Mem *pnErr;     /* Register keeping track of errors remaining */
-#endif /* local variables moved into u.by */
-
-  u.by.nRoot = pOp->p2;
-  assert( u.by.nRoot>0 );
-  u.by.aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(u.by.nRoot+1) );
-  if( u.by.aRoot==0 ) goto no_mem;
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  u.by.pnErr = &aMem[pOp->p3];
-  assert( (u.by.pnErr->flags & MEM_Int)!=0 );
-  assert( (u.by.pnErr->flags & (MEM_Str|MEM_Blob))==0 );
+
+  assert( p->bIsReader );
+  nRoot = pOp->p2;
+  aRoot = pOp->p4.ai;
+  assert( nRoot>0 );
+  assert( aRoot[nRoot]==0 );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  pnErr = &aMem[pOp->p3];
+  assert( (pnErr->flags & MEM_Int)!=0 );
+  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
   pIn1 = &aMem[pOp->p1];
-  for(u.by.j=0; u.by.j<u.by.nRoot; u.by.j++){
-    u.by.aRoot[u.by.j] = (int)sqlite3VdbeIntValue(&pIn1[u.by.j]);
-  }
-  u.by.aRoot[u.by.j] = 0;
   assert( pOp->p5<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p5))!=0 );
-  u.by.z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, u.by.aRoot, u.by.nRoot,
-                                 (int)u.by.pnErr->u.i, &u.by.nErr);
-  sqlite3DbFree(db, u.by.aRoot);
-  u.by.pnErr->u.i -= u.by.nErr;
+  assert( DbMaskTest(p->btreeMask, pOp->p5) );
+  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,
+                                 (int)pnErr->u.i, &nErr);
+  pnErr->u.i -= nErr;
   sqlite3VdbeMemSetNull(pIn1);
-  if( u.by.nErr==0 ){
-    assert( u.by.z==0 );
-  }else if( u.by.z==0 ){
+  if( nErr==0 ){
+    assert( z==0 );
+  }else if( z==0 ){
     goto no_mem;
   }else{
-    sqlite3VdbeMemSetStr(pIn1, u.by.z, -1, SQLITE_UTF8, sqlite3_free);
+    sqlite3VdbeMemSetStr(pIn1, z, -1, SQLITE_UTF8, sqlite3_free);
   }
   UPDATE_MAX_BLOBSIZE(pIn1);
   sqlite3VdbeChangeEncoding(pIn1, encoding);
@@ -68447,6 +82697,7 @@ case OP_IntegrityCk: {
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
 /* Opcode: RowSetAdd P1 P2 * * *
+** Synopsis:  rowset(P1)=r[P2]
 **
 ** Insert the integer value held by register P2 into a boolean index
 ** held in register P1.
@@ -68466,31 +82717,33 @@ case OP_RowSetAdd: {       /* in1, in2 */
 }
 
 /* Opcode: RowSetRead P1 P2 P3 * *
+** Synopsis:  r[P3]=rowset(P1)
 **
 ** Extract the smallest value from boolean index P1 and put that value into
 ** register P3.  Or, if boolean index P1 is initially empty, leave P3
 ** unchanged and jump to instruction P2.
 */
 case OP_RowSetRead: {       /* jump, in1, out3 */
-#if 0  /* local variables moved into u.bz */
   i64 val;
-#endif /* local variables moved into u.bz */
-  CHECK_FOR_INTERRUPT;
+
   pIn1 = &aMem[pOp->p1];
-  if( (pIn1->flags & MEM_RowSet)==0
-   || sqlite3RowSetNext(pIn1->u.pRowSet, &u.bz.val)==0
+  if( (pIn1->flags & MEM_RowSet)==0 
+   || sqlite3RowSetNext(pIn1->u.pRowSet, &val)==0
   ){
     /* The boolean index is empty */
     sqlite3VdbeMemSetNull(pIn1);
-    pc = pOp->p2 - 1;
+    VdbeBranchTaken(1,2);
+    goto jump_to_p2_and_check_for_interrupt;
   }else{
     /* A value was pulled from the index */
-    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], u.bz.val);
+    VdbeBranchTaken(0,2);
+    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], val);
   }
-  break;
+  goto check_for_interrupt;
 }
 
 /* Opcode: RowSetTest P1 P2 P3 P4
+** Synopsis: if r[P3] in rowset(P1) goto P2
 **
 ** Register P3 is assumed to hold a 64-bit integer value. If register P1
 ** contains a RowSet object and that RowSet object contains
@@ -68514,14 +82767,12 @@ case OP_RowSetRead: {       /* jump, in1, out3 */
 ** inserted as part of some other set).
 */
 case OP_RowSetTest: {                     /* jump, in1, in3 */
-#if 0  /* local variables moved into u.ca */
   int iSet;
   int exists;
-#endif /* local variables moved into u.ca */
 
   pIn1 = &aMem[pOp->p1];
   pIn3 = &aMem[pOp->p3];
-  u.ca.iSet = pOp->p4.i;
+  iSet = pOp->p4.i;
   assert( pIn3->flags&MEM_Int );
 
   /* If there is anything other than a rowset object in memory cell P1,
@@ -68533,17 +82784,13 @@ case OP_RowSetTest: {                     /* jump, in1, in3 */
   }
 
   assert( pOp->p4type==P4_INT32 );
-  assert( u.ca.iSet==-1 || u.ca.iSet>=0 );
-  if( u.ca.iSet ){
-    u.ca.exists = sqlite3RowSetTest(pIn1->u.pRowSet,
-                               (u8)(u.ca.iSet>=0 ? u.ca.iSet & 0xf : 0xff),
-                               pIn3->u.i);
-    if( u.ca.exists ){
-      pc = pOp->p2 - 1;
-      break;
-    }
+  assert( iSet==-1 || iSet>=0 );
+  if( iSet ){
+    exists = sqlite3RowSetTest(pIn1->u.pRowSet, iSet, pIn3->u.i);
+    VdbeBranchTaken(exists!=0,2);
+    if( exists ) goto jump_to_p2;
   }
-  if( u.ca.iSet>=0 ){
+  if( iSet>=0 ){
     sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
   }
   break;
@@ -68552,7 +82799,7 @@ case OP_RowSetTest: {                     /* jump, in1, in3 */
 
 #ifndef SQLITE_OMIT_TRIGGER
 
-/* Opcode: Program P1 P2 P3 P4 *
+/* Opcode: Program P1 P2 P3 P4 P5
 **
 ** Execute the trigger program passed as P4 (type P4_SUBPROGRAM). 
 **
@@ -68564,9 +82811,10 @@ case OP_RowSetTest: {                     /* jump, in1, in3 */
 ** memory required by the sub-vdbe at runtime.
 **
 ** P4 is a pointer to the VM containing the trigger program.
+**
+** If P5 is non-zero, then recursive program invocation is enabled.
 */
 case OP_Program: {        /* jump */
-#if 0  /* local variables moved into u.cb */
   int nMem;               /* Number of memory registers for sub-program */
   int nByte;              /* Bytes of runtime space required for sub-program */
   Mem *pRt;               /* Register to allocate runtime space */
@@ -68575,95 +82823,112 @@ case OP_Program: {        /* jump */
   VdbeFrame *pFrame;      /* New vdbe frame to execute in */
   SubProgram *pProgram;   /* Sub-program to execute */
   void *t;                /* Token identifying trigger */
-#endif /* local variables moved into u.cb */
 
-  u.cb.pProgram = pOp->p4.pProgram;
-  u.cb.pRt = &aMem[pOp->p3];
-  assert( memIsValid(u.cb.pRt) );
-  assert( u.cb.pProgram->nOp>0 );
-
-  /* If the p5 flag is clear, then recursive invocation of triggers is
+  pProgram = pOp->p4.pProgram;
+  pRt = &aMem[pOp->p3];
+  assert( pProgram->nOp>0 );
+  
+  /* If the p5 flag is clear, then recursive invocation of triggers is 
   ** disabled for backwards compatibility (p5 is set if this sub-program
   ** is really a trigger, not a foreign key action, and the flag set
   ** and cleared by the "PRAGMA recursive_triggers" command is clear).
-  **
-  ** It is recursive invocation of triggers, at the SQL level, that is
-  ** disabled. In some cases a single trigger may generate more than one
-  ** SubProgram (if the trigger may be executed with more than one different
+  ** 
+  ** It is recursive invocation of triggers, at the SQL level, that is 
+  ** disabled. In some cases a single trigger may generate more than one 
+  ** SubProgram (if the trigger may be executed with more than one different 
   ** ON CONFLICT algorithm). SubProgram structures associated with a
-  ** single trigger all have the same value for the SubProgram.token
+  ** single trigger all have the same value for the SubProgram.token 
   ** variable.  */
   if( pOp->p5 ){
-    u.cb.t = u.cb.pProgram->token;
-    for(u.cb.pFrame=p->pFrame; u.cb.pFrame && u.cb.pFrame->token!=u.cb.t; u.cb.pFrame=u.cb.pFrame->pParent);
-    if( u.cb.pFrame ) break;
+    t = pProgram->token;
+    for(pFrame=p->pFrame; pFrame && pFrame->token!=t; pFrame=pFrame->pParent);
+    if( pFrame ) break;
   }
 
   if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
     rc = SQLITE_ERROR;
-    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
-    break;
+    sqlite3VdbeError(p, "too many levels of trigger recursion");
+    goto abort_due_to_error;
   }
 
-  /* Register u.cb.pRt is used to store the memory required to save the state
+  /* Register pRt is used to store the memory required to save the state
   ** of the current program, and the memory required at runtime to execute
-  ** the trigger program. If this trigger has been fired before, then u.cb.pRt
+  ** the trigger program. If this trigger has been fired before, then pRt 
   ** is already allocated. Otherwise, it must be initialized.  */
-  if( (u.cb.pRt->flags&MEM_Frame)==0 ){
-    /* SubProgram.nMem is set to the number of memory cells used by the
+  if( (pRt->flags&MEM_Frame)==0 ){
+    /* SubProgram.nMem is set to the number of memory cells used by the 
     ** program stored in SubProgram.aOp. As well as these, one memory
     ** cell is required for each cursor used by the program. Set local
-    ** variable u.cb.nMem (and later, VdbeFrame.nChildMem) to this value.
+    ** variable nMem (and later, VdbeFrame.nChildMem) to this value.
     */
-    u.cb.nMem = u.cb.pProgram->nMem + u.cb.pProgram->nCsr;
-    u.cb.nByte = ROUND8(sizeof(VdbeFrame))
-              + u.cb.nMem * sizeof(Mem)
-              + u.cb.pProgram->nCsr * sizeof(VdbeCursor *);
-    u.cb.pFrame = sqlite3DbMallocZero(db, u.cb.nByte);
-    if( !u.cb.pFrame ){
+    nMem = pProgram->nMem + pProgram->nCsr;
+    assert( nMem>0 );
+    if( pProgram->nCsr==0 ) nMem++;
+    nByte = ROUND8(sizeof(VdbeFrame))
+              + nMem * sizeof(Mem)
+              + pProgram->nCsr * sizeof(VdbeCursor *)
+              + pProgram->nOnce * sizeof(u8);
+    pFrame = sqlite3DbMallocZero(db, nByte);
+    if( !pFrame ){
       goto no_mem;
     }
-    sqlite3VdbeMemRelease(u.cb.pRt);
-    u.cb.pRt->flags = MEM_Frame;
-    u.cb.pRt->u.pFrame = u.cb.pFrame;
-
-    u.cb.pFrame->v = p;
-    u.cb.pFrame->nChildMem = u.cb.nMem;
-    u.cb.pFrame->nChildCsr = u.cb.pProgram->nCsr;
-    u.cb.pFrame->pc = pc;
-    u.cb.pFrame->aMem = p->aMem;
-    u.cb.pFrame->nMem = p->nMem;
-    u.cb.pFrame->apCsr = p->apCsr;
-    u.cb.pFrame->nCursor = p->nCursor;
-    u.cb.pFrame->aOp = p->aOp;
-    u.cb.pFrame->nOp = p->nOp;
-    u.cb.pFrame->token = u.cb.pProgram->token;
-
-    u.cb.pEnd = &VdbeFrameMem(u.cb.pFrame)[u.cb.pFrame->nChildMem];
-    for(u.cb.pMem=VdbeFrameMem(u.cb.pFrame); u.cb.pMem!=u.cb.pEnd; u.cb.pMem++){
-      u.cb.pMem->flags = MEM_Null;
-      u.cb.pMem->db = db;
+    sqlite3VdbeMemRelease(pRt);
+    pRt->flags = MEM_Frame;
+    pRt->u.pFrame = pFrame;
+
+    pFrame->v = p;
+    pFrame->nChildMem = nMem;
+    pFrame->nChildCsr = pProgram->nCsr;
+    pFrame->pc = (int)(pOp - aOp);
+    pFrame->aMem = p->aMem;
+    pFrame->nMem = p->nMem;
+    pFrame->apCsr = p->apCsr;
+    pFrame->nCursor = p->nCursor;
+    pFrame->aOp = p->aOp;
+    pFrame->nOp = p->nOp;
+    pFrame->token = pProgram->token;
+    pFrame->aOnceFlag = p->aOnceFlag;
+    pFrame->nOnceFlag = p->nOnceFlag;
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+    pFrame->anExec = p->anExec;
+#endif
+
+    pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
+    for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
+      pMem->flags = MEM_Undefined;
+      pMem->db = db;
     }
   }else{
-    u.cb.pFrame = u.cb.pRt->u.pFrame;
-    assert( u.cb.pProgram->nMem+u.cb.pProgram->nCsr==u.cb.pFrame->nChildMem );
-    assert( u.cb.pProgram->nCsr==u.cb.pFrame->nChildCsr );
-    assert( pc==u.cb.pFrame->pc );
+    pFrame = pRt->u.pFrame;
+    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem 
+        || (pProgram->nCsr==0 && pProgram->nMem+1==pFrame->nChildMem) );
+    assert( pProgram->nCsr==pFrame->nChildCsr );
+    assert( (int)(pOp - aOp)==pFrame->pc );
   }
 
   p->nFrame++;
-  u.cb.pFrame->pParent = p->pFrame;
-  u.cb.pFrame->lastRowid = lastRowid;
-  u.cb.pFrame->nChange = p->nChange;
+  pFrame->pParent = p->pFrame;
+  pFrame->lastRowid = lastRowid;
+  pFrame->nChange = p->nChange;
+  pFrame->nDbChange = p->db->nChange;
+  assert( pFrame->pAuxData==0 );
+  pFrame->pAuxData = p->pAuxData;
+  p->pAuxData = 0;
   p->nChange = 0;
-  p->pFrame = u.cb.pFrame;
-  p->aMem = aMem = &VdbeFrameMem(u.cb.pFrame)[-1];
-  p->nMem = u.cb.pFrame->nChildMem;
-  p->nCursor = (u16)u.cb.pFrame->nChildCsr;
-  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
-  p->aOp = aOp = u.cb.pProgram->aOp;
-  p->nOp = u.cb.pProgram->nOp;
-  pc = -1;
+  p->pFrame = pFrame;
+  p->aMem = aMem = VdbeFrameMem(pFrame);
+  p->nMem = pFrame->nChildMem;
+  p->nCursor = (u16)pFrame->nChildCsr;
+  p->apCsr = (VdbeCursor **)&aMem[p->nMem];
+  p->aOp = aOp = pProgram->aOp;
+  p->nOp = pProgram->nOp;
+  p->aOnceFlag = (u8 *)&p->apCsr[p->nCursor];
+  p->nOnceFlag = pProgram->nOnce;
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  p->anExec = 0;
+#endif
+  pOp = &aOp[-1];
+  memset(p->aOnceFlag, 0, p->nOnceFlag);
 
   break;
 }
@@ -68680,14 +82945,13 @@ case OP_Program: {        /* jump */
 ** the value of the P1 argument to the value of the P1 argument to the
 ** calling OP_Program instruction.
 */
-case OP_Param: {           /* out2-prerelease */
-#if 0  /* local variables moved into u.cc */
+case OP_Param: {           /* out2 */
   VdbeFrame *pFrame;
   Mem *pIn;
-#endif /* local variables moved into u.cc */
-  u.cc.pFrame = p->pFrame;
-  u.cc.pIn = &u.cc.pFrame->aMem[pOp->p1 + u.cc.pFrame->aOp[u.cc.pFrame->pc].p1];
-  sqlite3VdbeMemShallowCopy(pOut, u.cc.pIn, MEM_Ephem);
+  pOut = out2Prerelease(p, pOp);
+  pFrame = p->pFrame;
+  pIn = &pFrame->aMem[pOp->p1 + pFrame->aOp[pFrame->pc].p1];   
+  sqlite3VdbeMemShallowCopy(pOut, pIn, MEM_Ephem);
   break;
 }
 
@@ -68695,6 +82959,7 @@ case OP_Param: {           /* out2-prerelease */
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 /* Opcode: FkCounter P1 P2 * * *
+** Synopsis: fkctr[P1]+=P2
 **
 ** Increment a "constraint counter" by P2 (P2 may be negative or positive).
 ** If P1 is non-zero, the database constraint counter is incremented 
@@ -68702,7 +82967,9 @@ case OP_Param: {           /* out2-prerelease */
 ** statement counter is incremented (immediate foreign key constraints).
 */
 case OP_FkCounter: {
-  if( pOp->p1 ){
+  if( db->flags & SQLITE_DeferFKs ){
+    db->nDeferredImmCons += pOp->p2;
+  }else if( pOp->p1 ){
     db->nDeferredCons += pOp->p2;
   }else{
     p->nFkConstraint += pOp->p2;
@@ -68711,6 +82978,7 @@ case OP_FkCounter: {
 }
 
 /* Opcode: FkIfZero P1 P2 * * *
+** Synopsis: if fkctr[P1]==0 goto P2
 **
 ** This opcode tests if a foreign key constraint-counter is currently zero.
 ** If so, jump to instruction P2. Otherwise, fall through to the next 
@@ -68723,9 +82991,11 @@ case OP_FkCounter: {
 */
 case OP_FkIfZero: {         /* jump */
   if( pOp->p1 ){
-    if( db->nDeferredCons==0 ) pc = pOp->p2-1;
+    VdbeBranchTaken(db->nDeferredCons==0 && db->nDeferredImmCons==0, 2);
+    if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;
   }else{
-    if( p->nFkConstraint==0 ) pc = pOp->p2-1;
+    VdbeBranchTaken(p->nFkConstraint==0 && db->nDeferredImmCons==0, 2);
+    if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;
   }
   break;
 }
@@ -68733,6 +83003,7 @@ case OP_FkIfZero: {         /* jump */
 
 #ifndef SQLITE_OMIT_AUTOINCREMENT
 /* Opcode: MemMax P1 P2 * * *
+** Synopsis: r[P1]=max(r[P1],r[P2])
 **
 ** P1 is a register in the root frame of this VM (the root frame is
 ** different from the current frame if this instruction is being executed
@@ -68743,137 +83014,209 @@ case OP_FkIfZero: {         /* jump */
 ** an integer.
 */
 case OP_MemMax: {        /* in2 */
-#if 0  /* local variables moved into u.cd */
-  Mem *pIn1;
   VdbeFrame *pFrame;
-#endif /* local variables moved into u.cd */
   if( p->pFrame ){
-    for(u.cd.pFrame=p->pFrame; u.cd.pFrame->pParent; u.cd.pFrame=u.cd.pFrame->pParent);
-    u.cd.pIn1 = &u.cd.pFrame->aMem[pOp->p1];
+    for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
+    pIn1 = &pFrame->aMem[pOp->p1];
   }else{
-    u.cd.pIn1 = &aMem[pOp->p1];
+    pIn1 = &aMem[pOp->p1];
   }
-  assert( memIsValid(u.cd.pIn1) );
-  sqlite3VdbeMemIntegerify(u.cd.pIn1);
+  assert( memIsValid(pIn1) );
+  sqlite3VdbeMemIntegerify(pIn1);
   pIn2 = &aMem[pOp->p2];
   sqlite3VdbeMemIntegerify(pIn2);
-  if( u.cd.pIn1->u.i<pIn2->u.i){
-    u.cd.pIn1->u.i = pIn2->u.i;
+  if( pIn1->u.i<pIn2->u.i){
+    pIn1->u.i = pIn2->u.i;
   }
   break;
 }
 #endif /* SQLITE_OMIT_AUTOINCREMENT */
 
-/* Opcode: IfPos P1 P2 * * *
+/* Opcode: IfPos P1 P2 P3 * *
+** Synopsis: if r[P1]>0 then r[P1]-=P3, goto P2
 **
-** If the value of register P1 is 1 or greater, jump to P2.
+** Register P1 must contain an integer.
+** If the value of register P1 is 1 or greater, subtract P3 from the
+** value in P1 and jump to P2.
 **
-** It is illegal to use this instruction on a register that does
-** not contain an integer.  An assertion fault will result if you try.
+** If the initial value of register P1 is less than 1, then the
+** value is unchanged and control passes through to the next instruction.
 */
 case OP_IfPos: {        /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
+  VdbeBranchTaken( pIn1->u.i>0, 2);
   if( pIn1->u.i>0 ){
-     pc = pOp->p2 - 1;
+    pIn1->u.i -= pOp->p3;
+    goto jump_to_p2;
   }
   break;
 }
 
-/* Opcode: IfNeg P1 P2 * * *
+/* Opcode: OffsetLimit P1 P2 P3 * *
+** Synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)
+**
+** This opcode performs a commonly used computation associated with
+** LIMIT and OFFSET process.  r[P1] holds the limit counter.  r[P3]
+** holds the offset counter.  The opcode computes the combined value
+** of the LIMIT and OFFSET and stores that value in r[P2].  The r[P2]
+** value computed is the total number of rows that will need to be
+** visited in order to complete the query.
+**
+** If r[P3] is zero or negative, that means there is no OFFSET
+** and r[P2] is set to be the value of the LIMIT, r[P1].
 **
-** If the value of register P1 is less than zero, jump to P2. 
+** if r[P1] is zero or negative, that means there is no LIMIT
+** and r[P2] is set to -1. 
 **
-** It is illegal to use this instruction on a register that does
-** not contain an integer.  An assertion fault will result if you try.
+** Otherwise, r[P2] is set to the sum of r[P1] and r[P3].
 */
-case OP_IfNeg: {        /* jump, in1 */
+case OP_OffsetLimit: {    /* in1, out2, in3 */
+  pIn1 = &aMem[pOp->p1];
+  pIn3 = &aMem[pOp->p3];
+  pOut = out2Prerelease(p, pOp);
+  assert( pIn1->flags & MEM_Int );
+  assert( pIn3->flags & MEM_Int );
+  pOut->u.i = pIn1->u.i<=0 ? -1 : pIn1->u.i+(pIn3->u.i>0?pIn3->u.i:0);
+  break;
+}
+
+/* Opcode: IfNotZero P1 P2 P3 * *
+** Synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2
+**
+** Register P1 must contain an integer.  If the content of register P1 is
+** initially nonzero, then subtract P3 from the value in register P1 and
+** jump to P2.  If register P1 is initially zero, leave it unchanged
+** and fall through.
+*/
+case OP_IfNotZero: {        /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
-  if( pIn1->u.i<0 ){
-     pc = pOp->p2 - 1;
+  VdbeBranchTaken(pIn1->u.i<0, 2);
+  if( pIn1->u.i ){
+     pIn1->u.i -= pOp->p3;
+     goto jump_to_p2;
   }
   break;
 }
 
-/* Opcode: IfZero P1 P2 P3 * *
+/* Opcode: DecrJumpZero P1 P2 * * *
+** Synopsis: if (--r[P1])==0 goto P2
 **
-** The register P1 must contain an integer.  Add literal P3 to the
-** value in register P1.  If the result is exactly 0, jump to P2. 
-**
-** It is illegal to use this instruction on a register that does
-** not contain an integer.  An assertion fault will result if you try.
+** Register P1 must hold an integer.  Decrement the value in register P1
+** then jump to P2 if the new value is exactly zero.
 */
-case OP_IfZero: {        /* jump, in1 */
+case OP_DecrJumpZero: {      /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
   assert( pIn1->flags&MEM_Int );
-  pIn1->u.i += pOp->p3;
-  if( pIn1->u.i==0 ){
-     pc = pOp->p2 - 1;
-  }
+  pIn1->u.i--;
+  VdbeBranchTaken(pIn1->u.i==0, 2);
+  if( pIn1->u.i==0 ) goto jump_to_p2;
   break;
 }
 
-/* Opcode: AggStep * P2 P3 P4 P5
+
+/* Opcode: AggStep0 * P2 P3 P4 P5
+** Synopsis: accum=r[P3] step(r[P2@P5])
 **
 ** Execute the step function for an aggregate.  The
 ** function has P5 arguments.   P4 is a pointer to the FuncDef
-** structure that specifies the function.  Use register
-** P3 as the accumulator.
+** structure that specifies the function.  Register P3 is the
+** accumulator.
 **
 ** The P5 arguments are taken from register P2 and its
 ** successors.
 */
-case OP_AggStep: {
-#if 0  /* local variables moved into u.ce */
+/* Opcode: AggStep * P2 P3 P4 P5
+** Synopsis: accum=r[P3] step(r[P2@P5])
+**
+** Execute the step function for an aggregate.  The
+** function has P5 arguments.   P4 is a pointer to an sqlite3_context
+** object that is used to run the function.  Register P3 is
+** as the accumulator.
+**
+** The P5 arguments are taken from register P2 and its
+** successors.
+**
+** This opcode is initially coded as OP_AggStep0.  On first evaluation,
+** the FuncDef stored in P4 is converted into an sqlite3_context and
+** the opcode is changed.  In this way, the initialization of the
+** sqlite3_context only happens once, instead of on each call to the
+** step function.
+*/
+case OP_AggStep0: {
   int n;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCDEF );
+  n = pOp->p5;
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
+  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
+  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
+  if( pCtx==0 ) goto no_mem;
+  pCtx->pMem = 0;
+  pCtx->pFunc = pOp->p4.pFunc;
+  pCtx->iOp = (int)(pOp - aOp);
+  pCtx->pVdbe = p;
+  pCtx->argc = n;
+  pOp->p4type = P4_FUNCCTX;
+  pOp->p4.pCtx = pCtx;
+  pOp->opcode = OP_AggStep;
+  /* Fall through into OP_AggStep */
+}
+case OP_AggStep: {
   int i;
+  sqlite3_context *pCtx;
   Mem *pMem;
-  Mem *pRec;
-  sqlite3_context ctx;
-  sqlite3_value **apVal;
-#endif /* local variables moved into u.ce */
-
-  u.ce.n = pOp->p5;
-  assert( u.ce.n>=0 );
-  u.ce.pRec = &aMem[pOp->p2];
-  u.ce.apVal = p->apArg;
-  assert( u.ce.apVal || u.ce.n==0 );
-  for(u.ce.i=0; u.ce.i<u.ce.n; u.ce.i++, u.ce.pRec++){
-    assert( memIsValid(u.ce.pRec) );
-    u.ce.apVal[u.ce.i] = u.ce.pRec;
-    memAboutToChange(p, u.ce.pRec);
-    sqlite3VdbeMemStoreType(u.ce.pRec);
-  }
-  u.ce.ctx.pFunc = pOp->p4.pFunc;
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  u.ce.ctx.pMem = u.ce.pMem = &aMem[pOp->p3];
-  u.ce.pMem->n++;
-  u.ce.ctx.s.flags = MEM_Null;
-  u.ce.ctx.s.z = 0;
-  u.ce.ctx.s.zMalloc = 0;
-  u.ce.ctx.s.xDel = 0;
-  u.ce.ctx.s.db = db;
-  u.ce.ctx.isError = 0;
-  u.ce.ctx.pColl = 0;
-  if( u.ce.ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
-    assert( pOp>p->aOp );
-    assert( pOp[-1].p4type==P4_COLLSEQ );
-    assert( pOp[-1].opcode==OP_CollSeq );
-    u.ce.ctx.pColl = pOp[-1].p4.pColl;
-  }
-  (u.ce.ctx.pFunc->xStep)(&u.ce.ctx, u.ce.n, u.ce.apVal); /* IMP: R-24505-23230 */
-  if( u.ce.ctx.isError ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&u.ce.ctx.s));
-    rc = u.ce.ctx.isError;
+  Mem t;
+
+  assert( pOp->p4type==P4_FUNCCTX );
+  pCtx = pOp->p4.pCtx;
+  pMem = &aMem[pOp->p3];
+
+  /* If this function is inside of a trigger, the register array in aMem[]
+  ** might change from one evaluation to the next.  The next block of code
+  ** checks to see if the register array has changed, and if so it
+  ** reinitializes the relavant parts of the sqlite3_context object */
+  if( pCtx->pMem != pMem ){
+    pCtx->pMem = pMem;
+    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
   }
 
-  sqlite3VdbeMemRelease(&u.ce.ctx.s);
+#ifdef SQLITE_DEBUG
+  for(i=0; i<pCtx->argc; i++){
+    assert( memIsValid(pCtx->argv[i]) );
+    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
+  }
+#endif
 
+  pMem->n++;
+  sqlite3VdbeMemInit(&t, db, MEM_Null);
+  pCtx->pOut = &t;
+  pCtx->fErrorOrAux = 0;
+  pCtx->skipFlag = 0;
+  (pCtx->pFunc->xSFunc)(pCtx,pCtx->argc,pCtx->argv); /* IMP: R-24505-23230 */
+  if( pCtx->fErrorOrAux ){
+    if( pCtx->isError ){
+      sqlite3VdbeError(p, "%s", sqlite3_value_text(&t));
+      rc = pCtx->isError;
+    }
+    sqlite3VdbeMemRelease(&t);
+    if( rc ) goto abort_due_to_error;
+  }else{
+    assert( t.flags==MEM_Null );
+  }
+  if( pCtx->skipFlag ){
+    assert( pOp[-1].opcode==OP_CollSeq );
+    i = pOp[-1].p1;
+    if( i ) sqlite3VdbeMemSetInt64(&aMem[i], 1);
+  }
   break;
 }
 
 /* Opcode: AggFinal P1 P2 * P4 *
+** Synopsis: accum=r[P1] N=P2
 **
 ** Execute the finalizer function for an aggregate.  P1 is
 ** the memory location that is the accumulator for the aggregate.
@@ -68886,19 +83229,18 @@ case OP_AggStep: {
 ** the step function was not previously called.
 */
 case OP_AggFinal: {
-#if 0  /* local variables moved into u.cf */
   Mem *pMem;
-#endif /* local variables moved into u.cf */
-  assert( pOp->p1>0 && pOp->p1<=p->nMem );
-  u.cf.pMem = &aMem[pOp->p1];
-  assert( (u.cf.pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
-  rc = sqlite3VdbeMemFinalize(u.cf.pMem, pOp->p4.pFunc);
+  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
+  pMem = &aMem[pOp->p1];
+  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
+  rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
   if( rc ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(u.cf.pMem));
+    sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));
+    goto abort_due_to_error;
   }
-  sqlite3VdbeChangeEncoding(u.cf.pMem, encoding);
-  UPDATE_MAX_BLOBSIZE(u.cf.pMem);
-  if( sqlite3VdbeMemTooBig(u.cf.pMem) ){
+  sqlite3VdbeChangeEncoding(pMem, encoding);
+  UPDATE_MAX_BLOBSIZE(pMem);
+  if( sqlite3VdbeMemTooBig(pMem) ){
     goto too_big;
   }
   break;
@@ -68908,8 +83250,8 @@ case OP_AggFinal: {
 /* Opcode: Checkpoint P1 P2 P3 * *
 **
 ** Checkpoint database P1. This is a no-op if P1 is not currently in
-** WAL mode. Parameter P2 is one of SQLITE_CHECKPOINT_PASSIVE, FULL
-** or RESTART.  Write 1 or 0 into mem[P3] if the checkpoint returns
+** WAL mode. Parameter P2 is one of SQLITE_CHECKPOINT_PASSIVE, FULL,
+** RESTART, or TRUNCATE.  Write 1 or 0 into mem[P3] if the checkpoint returns
 ** SQLITE_BUSY or not, respectively.  Write the number of pages in the
 ** WAL after the checkpoint into mem[P3+1] and the number of pages
 ** in the WAL that have been checkpointed after the checkpoint
@@ -68917,32 +83259,33 @@ case OP_AggFinal: {
 ** mem[P3+2] are initialized to -1.
 */
 case OP_Checkpoint: {
-#if 0  /* local variables moved into u.cg */
   int i;                          /* Loop counter */
   int aRes[3];                    /* Results */
   Mem *pMem;                      /* Write results here */
-#endif /* local variables moved into u.cg */
 
-  u.cg.aRes[0] = 0;
-  u.cg.aRes[1] = u.cg.aRes[2] = -1;
+  assert( p->readOnly==0 );
+  aRes[0] = 0;
+  aRes[1] = aRes[2] = -1;
   assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
        || pOp->p2==SQLITE_CHECKPOINT_FULL
        || pOp->p2==SQLITE_CHECKPOINT_RESTART
+       || pOp->p2==SQLITE_CHECKPOINT_TRUNCATE
   );
-  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &u.cg.aRes[1], &u.cg.aRes[2]);
-  if( rc==SQLITE_BUSY ){
+  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &aRes[1], &aRes[2]);
+  if( rc ){
+    if( rc!=SQLITE_BUSY ) goto abort_due_to_error;
     rc = SQLITE_OK;
-    u.cg.aRes[0] = 1;
-  }
-  for(u.cg.i=0, u.cg.pMem = &aMem[pOp->p3]; u.cg.i<3; u.cg.i++, u.cg.pMem++){
-    sqlite3VdbeMemSetInt64(u.cg.pMem, (i64)u.cg.aRes[u.cg.i]);
+    aRes[0] = 1;
   }
+  for(i=0, pMem = &aMem[pOp->p3]; i<3; i++, pMem++){
+    sqlite3VdbeMemSetInt64(pMem, (i64)aRes[i]);
+  }    
   break;
 };  
 #endif
 
 #ifndef SQLITE_OMIT_PRAGMA
-/* Opcode: JournalMode P1 P2 P3 * P5
+/* Opcode: JournalMode P1 P2 P3 * *
 **
 ** Change the journal mode of database P1 to P3. P3 must be one of the
 ** PAGER_JOURNALMODE_XXX values. If changing between the various rollback
@@ -68953,95 +83296,95 @@ case OP_Checkpoint: {
 **
 ** Write a string containing the final journal-mode to register P2.
 */
-case OP_JournalMode: {    /* out2-prerelease */
-#if 0  /* local variables moved into u.ch */
+case OP_JournalMode: {    /* out2 */
   Btree *pBt;                     /* Btree to change journal mode of */
   Pager *pPager;                  /* Pager associated with pBt */
   int eNew;                       /* New journal mode */
   int eOld;                       /* The old journal mode */
+#ifndef SQLITE_OMIT_WAL
   const char *zFilename;          /* Name of database file for pPager */
-#endif /* local variables moved into u.ch */
-
-  u.ch.eNew = pOp->p3;
-  assert( u.ch.eNew==PAGER_JOURNALMODE_DELETE
-       || u.ch.eNew==PAGER_JOURNALMODE_TRUNCATE
-       || u.ch.eNew==PAGER_JOURNALMODE_PERSIST
-       || u.ch.eNew==PAGER_JOURNALMODE_OFF
-       || u.ch.eNew==PAGER_JOURNALMODE_MEMORY
-       || u.ch.eNew==PAGER_JOURNALMODE_WAL
-       || u.ch.eNew==PAGER_JOURNALMODE_QUERY
+#endif
+
+  pOut = out2Prerelease(p, pOp);
+  eNew = pOp->p3;
+  assert( eNew==PAGER_JOURNALMODE_DELETE 
+       || eNew==PAGER_JOURNALMODE_TRUNCATE 
+       || eNew==PAGER_JOURNALMODE_PERSIST 
+       || eNew==PAGER_JOURNALMODE_OFF
+       || eNew==PAGER_JOURNALMODE_MEMORY
+       || eNew==PAGER_JOURNALMODE_WAL
+       || eNew==PAGER_JOURNALMODE_QUERY
   );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( p->readOnly==0 );
 
-  u.ch.pBt = db->aDb[pOp->p1].pBt;
-  u.ch.pPager = sqlite3BtreePager(u.ch.pBt);
-  u.ch.eOld = sqlite3PagerGetJournalMode(u.ch.pPager);
-  if( u.ch.eNew==PAGER_JOURNALMODE_QUERY ) u.ch.eNew = u.ch.eOld;
-  if( !sqlite3PagerOkToChangeJournalMode(u.ch.pPager) ) u.ch.eNew = u.ch.eOld;
+  pBt = db->aDb[pOp->p1].pBt;
+  pPager = sqlite3BtreePager(pBt);
+  eOld = sqlite3PagerGetJournalMode(pPager);
+  if( eNew==PAGER_JOURNALMODE_QUERY ) eNew = eOld;
+  if( !sqlite3PagerOkToChangeJournalMode(pPager) ) eNew = eOld;
 
 #ifndef SQLITE_OMIT_WAL
-  u.ch.zFilename = sqlite3PagerFilename(u.ch.pPager);
+  zFilename = sqlite3PagerFilename(pPager, 1);
 
   /* Do not allow a transition to journal_mode=WAL for a database
-  ** in temporary storage or if the VFS does not support shared memory
+  ** in temporary storage or if the VFS does not support shared memory 
   */
-  if( u.ch.eNew==PAGER_JOURNALMODE_WAL
-   && (sqlite3Strlen30(u.ch.zFilename)==0           /* Temp file */
-       || !sqlite3PagerWalSupported(u.ch.pPager))   /* No shared-memory support */
+  if( eNew==PAGER_JOURNALMODE_WAL
+   && (sqlite3Strlen30(zFilename)==0           /* Temp file */
+       || !sqlite3PagerWalSupported(pPager))   /* No shared-memory support */
   ){
-    u.ch.eNew = u.ch.eOld;
+    eNew = eOld;
   }
 
-  if( (u.ch.eNew!=u.ch.eOld)
-   && (u.ch.eOld==PAGER_JOURNALMODE_WAL || u.ch.eNew==PAGER_JOURNALMODE_WAL)
+  if( (eNew!=eOld)
+   && (eOld==PAGER_JOURNALMODE_WAL || eNew==PAGER_JOURNALMODE_WAL)
   ){
-    if( !db->autoCommit || db->activeVdbeCnt>1 ){
+    if( !db->autoCommit || db->nVdbeRead>1 ){
       rc = SQLITE_ERROR;
-      sqlite3SetString(&p->zErrMsg, db,
+      sqlite3VdbeError(p,
           "cannot change %s wal mode from within a transaction",
-          (u.ch.eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
+          (eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
       );
-      break;
+      goto abort_due_to_error;
     }else{
-
-      if( u.ch.eOld==PAGER_JOURNALMODE_WAL ){
+ 
+      if( eOld==PAGER_JOURNALMODE_WAL ){
         /* If leaving WAL mode, close the log file. If successful, the call
-        ** to PagerCloseWal() checkpoints and deletes the write-ahead-log
-        ** file. An EXCLUSIVE lock may still be held on the database file
-        ** after a successful return.
+        ** to PagerCloseWal() checkpoints and deletes the write-ahead-log 
+        ** file. An EXCLUSIVE lock may still be held on the database file 
+        ** after a successful return. 
         */
-        rc = sqlite3PagerCloseWal(u.ch.pPager);
+        rc = sqlite3PagerCloseWal(pPager);
         if( rc==SQLITE_OK ){
-          sqlite3PagerSetJournalMode(u.ch.pPager, u.ch.eNew);
+          sqlite3PagerSetJournalMode(pPager, eNew);
         }
-      }else if( u.ch.eOld==PAGER_JOURNALMODE_MEMORY ){
+      }else if( eOld==PAGER_JOURNALMODE_MEMORY ){
         /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
         ** as an intermediate */
-        sqlite3PagerSetJournalMode(u.ch.pPager, PAGER_JOURNALMODE_OFF);
+        sqlite3PagerSetJournalMode(pPager, PAGER_JOURNALMODE_OFF);
       }
-
+  
       /* Open a transaction on the database file. Regardless of the journal
       ** mode, this transaction always uses a rollback journal.
       */
-      assert( sqlite3BtreeIsInTrans(u.ch.pBt)==0 );
+      assert( sqlite3BtreeIsInTrans(pBt)==0 );
       if( rc==SQLITE_OK ){
-        rc = sqlite3BtreeSetVersion(u.ch.pBt, (u.ch.eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
+        rc = sqlite3BtreeSetVersion(pBt, (eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
       }
     }
   }
 #endif /* ifndef SQLITE_OMIT_WAL */
 
-  if( rc ){
-    u.ch.eNew = u.ch.eOld;
-  }
-  u.ch.eNew = sqlite3PagerSetJournalMode(u.ch.pPager, u.ch.eNew);
+  if( rc ) eNew = eOld;
+  eNew = sqlite3PagerSetJournalMode(pPager, eNew);
 
-  pOut = &aMem[pOp->p2];
   pOut->flags = MEM_Str|MEM_Static|MEM_Term;
-  pOut->z = (char *)sqlite3JournalModename(u.ch.eNew);
+  pOut->z = (char *)sqlite3JournalModename(eNew);
   pOut->n = sqlite3Strlen30(pOut->z);
   pOut->enc = SQLITE_UTF8;
   sqlite3VdbeChangeEncoding(pOut, encoding);
+  if( rc ) goto abort_due_to_error;
   break;
 };
 #endif /* SQLITE_OMIT_PRAGMA */
@@ -69054,7 +83397,9 @@ case OP_JournalMode: {    /* out2-prerelease */
 ** a transaction.
 */
 case OP_Vacuum: {
+  assert( p->readOnly==0 );
   rc = sqlite3RunVacuum(&p->zErrMsg, db);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif
@@ -69067,17 +83412,18 @@ case OP_Vacuum: {
 ** P2. Otherwise, fall through to the next instruction.
 */
 case OP_IncrVacuum: {        /* jump */
-#if 0  /* local variables moved into u.ci */
   Btree *pBt;
-#endif /* local variables moved into u.ci */
 
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
-  u.ci.pBt = db->aDb[pOp->p1].pBt;
-  rc = sqlite3BtreeIncrVacuum(u.ci.pBt);
-  if( rc==SQLITE_DONE ){
-    pc = pOp->p2 - 1;
+  assert( DbMaskTest(p->btreeMask, pOp->p1) );
+  assert( p->readOnly==0 );
+  pBt = db->aDb[pOp->p1].pBt;
+  rc = sqlite3BtreeIncrVacuum(pBt);
+  VdbeBranchTaken(rc==SQLITE_DONE,2);
+  if( rc ){
+    if( rc!=SQLITE_DONE ) goto abort_due_to_error;
     rc = SQLITE_OK;
+    goto jump_to_p2;
   }
   break;
 }
@@ -69085,12 +83431,13 @@ case OP_IncrVacuum: {        /* jump */
 
 /* Opcode: Expire P1 * * * *
 **
-** Cause precompiled statements to become expired. An expired statement
-** fails with an error code of SQLITE_SCHEMA if it is ever executed 
-** (via sqlite3_step()).
+** Cause precompiled statements to expire.  When an expired statement
+** is executed using sqlite3_step() it will either automatically
+** reprepare itself (if it was originally created using sqlite3_prepare_v2())
+** or it will fail with SQLITE_SCHEMA.
 ** 
 ** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,
-** then only the currently executing statement is affected. 
+** then only the currently executing statement is expired.
 */
 case OP_Expire: {
   if( !pOp->p1 ){
@@ -69103,6 +83450,7 @@ case OP_Expire: {
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
 /* Opcode: TableLock P1 P2 P3 P4 *
+** Synopsis: iDb=P1 root=P2 write=P3
 **
 ** Obtain a lock on a particular table. This instruction is only used when
 ** the shared-cache feature is enabled. 
@@ -69121,12 +83469,15 @@ case OP_TableLock: {
   if( isWriteLock || 0==(db->flags&SQLITE_ReadUncommitted) ){
     int p1 = pOp->p1; 
     assert( p1>=0 && p1<db->nDb );
-    assert( (p->btreeMask & (((yDbMask)1)<<p1))!=0 );
+    assert( DbMaskTest(p->btreeMask, p1) );
     assert( isWriteLock==0 || isWriteLock==1 );
     rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
-    if( (rc&0xFF)==SQLITE_LOCKED ){
-      const char *z = pOp->p4.z;
-      sqlite3SetString(&p->zErrMsg, db, "database table is locked: %s", z);
+    if( rc ){
+      if( (rc&0xFF)==SQLITE_LOCKED ){
+        const char *z = pOp->p4.z;
+        sqlite3VdbeError(p, "database table is locked: %s", z);
+      }
+      goto abort_due_to_error;
     }
   }
   break;
@@ -69144,24 +83495,40 @@ case OP_TableLock: {
 ** code will be set to SQLITE_LOCKED.
 */
 case OP_VBegin: {
-#if 0  /* local variables moved into u.cj */
   VTable *pVTab;
-#endif /* local variables moved into u.cj */
-  u.cj.pVTab = pOp->p4.pVtab;
-  rc = sqlite3VtabBegin(db, u.cj.pVTab);
-  if( u.cj.pVTab ) importVtabErrMsg(p, u.cj.pVTab->pVtab);
+  pVTab = pOp->p4.pVtab;
+  rc = sqlite3VtabBegin(db, pVTab);
+  if( pVTab ) sqlite3VtabImportErrmsg(p, pVTab->pVtab);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-/* Opcode: VCreate P1 * * P4 *
+/* Opcode: VCreate P1 P2 * * *
 **
-** P4 is the name of a virtual table in database P1. Call the xCreate method
-** for that table.
+** P2 is a register that holds the name of a virtual table in database 
+** P1. Call the xCreate method for that table.
 */
 case OP_VCreate: {
-  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.z, &p->zErrMsg);
+  Mem sMem;          /* For storing the record being decoded */
+  const char *zTab;  /* Name of the virtual table */
+
+  memset(&sMem, 0, sizeof(sMem));
+  sMem.db = db;
+  /* Because P2 is always a static string, it is impossible for the
+  ** sqlite3VdbeMemCopy() to fail */
+  assert( (aMem[pOp->p2].flags & MEM_Str)!=0 );
+  assert( (aMem[pOp->p2].flags & MEM_Static)!=0 );
+  rc = sqlite3VdbeMemCopy(&sMem, &aMem[pOp->p2]);
+  assert( rc==SQLITE_OK );
+  zTab = (const char*)sqlite3_value_text(&sMem);
+  assert( zTab || db->mallocFailed );
+  if( zTab ){
+    rc = sqlite3VtabCallCreate(db, pOp->p1, zTab, &p->zErrMsg);
+  }
+  sqlite3VdbeMemRelease(&sMem);
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -69173,9 +83540,10 @@ case OP_VCreate: {
 ** of that table.
 */
 case OP_VDestroy: {
-  p->inVtabMethod = 2;
+  db->nVDestroy++;
   rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
-  p->inVtabMethod = 0;
+  db->nVDestroy--;
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -69188,33 +83556,36 @@ case OP_VDestroy: {
 ** table and stores that cursor in P1.
 */
 case OP_VOpen: {
-#if 0  /* local variables moved into u.ck */
   VdbeCursor *pCur;
-  sqlite3_vtab_cursor *pVtabCursor;
+  sqlite3_vtab_cursor *pVCur;
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
-#endif /* local variables moved into u.ck */
-
-  u.ck.pCur = 0;
-  u.ck.pVtabCursor = 0;
-  u.ck.pVtab = pOp->p4.pVtab->pVtab;
-  u.ck.pModule = (sqlite3_module *)u.ck.pVtab->pModule;
-  assert(u.ck.pVtab && u.ck.pModule);
-  rc = u.ck.pModule->xOpen(u.ck.pVtab, &u.ck.pVtabCursor);
-  importVtabErrMsg(p, u.ck.pVtab);
-  if( SQLITE_OK==rc ){
-    /* Initialize sqlite3_vtab_cursor base class */
-    u.ck.pVtabCursor->pVtab = u.ck.pVtab;
+  const sqlite3_module *pModule;
 
-    /* Initialise vdbe cursor object */
-    u.ck.pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
-    if( u.ck.pCur ){
-      u.ck.pCur->pVtabCursor = u.ck.pVtabCursor;
-      u.ck.pCur->pModule = u.ck.pVtabCursor->pVtab->pModule;
-    }else{
-      db->mallocFailed = 1;
-      u.ck.pModule->xClose(u.ck.pVtabCursor);
-    }
+  assert( p->bIsReader );
+  pCur = 0;
+  pVCur = 0;
+  pVtab = pOp->p4.pVtab->pVtab;
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    goto abort_due_to_error;
+  }
+  pModule = pVtab->pModule;
+  rc = pModule->xOpen(pVtab, &pVCur);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  if( rc ) goto abort_due_to_error;
+
+  /* Initialize sqlite3_vtab_cursor base class */
+  pVCur->pVtab = pVtab;
+
+  /* Initialize vdbe cursor object */
+  pCur = allocateCursor(p, pOp->p1, 0, -1, CURTYPE_VTAB);
+  if( pCur ){
+    pCur->uc.pVCur = pVCur;
+    pVtab->nRef++;
+  }else{
+    assert( db->mallocFailed );
+    pModule->xClose(pVCur);
+    goto no_mem;
   }
   break;
 }
@@ -69222,6 +83593,7 @@ case OP_VOpen: {
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /* Opcode: VFilter P1 P2 P3 P4 *
+** Synopsis: iplan=r[P3] zplan='P4'
 **
 ** P1 is a cursor opened using VOpen.  P2 is an address to jump to if
 ** the filtered result set is empty.
@@ -69240,117 +83612,92 @@ case OP_VOpen: {
 ** A jump is made to P2 if the result set after filtering would be empty.
 */
 case OP_VFilter: {   /* jump */
-#if 0  /* local variables moved into u.cl */
   int nArg;
   int iQuery;
   const sqlite3_module *pModule;
   Mem *pQuery;
   Mem *pArgc;
-  sqlite3_vtab_cursor *pVtabCursor;
+  sqlite3_vtab_cursor *pVCur;
   sqlite3_vtab *pVtab;
   VdbeCursor *pCur;
   int res;
   int i;
   Mem **apArg;
-#endif /* local variables moved into u.cl */
-
-  u.cl.pQuery = &aMem[pOp->p3];
-  u.cl.pArgc = &u.cl.pQuery[1];
-  u.cl.pCur = p->apCsr[pOp->p1];
-  assert( memIsValid(u.cl.pQuery) );
-  REGISTER_TRACE(pOp->p3, u.cl.pQuery);
-  assert( u.cl.pCur->pVtabCursor );
-  u.cl.pVtabCursor = u.cl.pCur->pVtabCursor;
-  u.cl.pVtab = u.cl.pVtabCursor->pVtab;
-  u.cl.pModule = u.cl.pVtab->pModule;
+
+  pQuery = &aMem[pOp->p3];
+  pArgc = &pQuery[1];
+  pCur = p->apCsr[pOp->p1];
+  assert( memIsValid(pQuery) );
+  REGISTER_TRACE(pOp->p3, pQuery);
+  assert( pCur->eCurType==CURTYPE_VTAB );
+  pVCur = pCur->uc.pVCur;
+  pVtab = pVCur->pVtab;
+  pModule = pVtab->pModule;
 
   /* Grab the index number and argc parameters */
-  assert( (u.cl.pQuery->flags&MEM_Int)!=0 && u.cl.pArgc->flags==MEM_Int );
-  u.cl.nArg = (int)u.cl.pArgc->u.i;
-  u.cl.iQuery = (int)u.cl.pQuery->u.i;
+  assert( (pQuery->flags&MEM_Int)!=0 && pArgc->flags==MEM_Int );
+  nArg = (int)pArgc->u.i;
+  iQuery = (int)pQuery->u.i;
 
   /* Invoke the xFilter method */
-  {
-    u.cl.res = 0;
-    u.cl.apArg = p->apArg;
-    for(u.cl.i = 0; u.cl.i<u.cl.nArg; u.cl.i++){
-      u.cl.apArg[u.cl.i] = &u.cl.pArgc[u.cl.i+1];
-      sqlite3VdbeMemStoreType(u.cl.apArg[u.cl.i]);
-    }
-
-    p->inVtabMethod = 1;
-    rc = u.cl.pModule->xFilter(u.cl.pVtabCursor, u.cl.iQuery, pOp->p4.z, u.cl.nArg, u.cl.apArg);
-    p->inVtabMethod = 0;
-    importVtabErrMsg(p, u.cl.pVtab);
-    if( rc==SQLITE_OK ){
-      u.cl.res = u.cl.pModule->xEof(u.cl.pVtabCursor);
-    }
-
-    if( u.cl.res ){
-      pc = pOp->p2 - 1;
-    }
-  }
-  u.cl.pCur->nullRow = 0;
-
+  res = 0;
+  apArg = p->apArg;
+  for(i = 0; i<nArg; i++){
+    apArg[i] = &pArgc[i+1];
+  }
+  rc = pModule->xFilter(pVCur, iQuery, pOp->p4.z, nArg, apArg);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  if( rc ) goto abort_due_to_error;
+  res = pModule->xEof(pVCur);
+  pCur->nullRow = 0;
+  VdbeBranchTaken(res!=0,2);
+  if( res ) goto jump_to_p2;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /* Opcode: VColumn P1 P2 P3 * *
+** Synopsis: r[P3]=vcolumn(P2)
 **
 ** Store the value of the P2-th column of
 ** the row of the virtual-table that the 
 ** P1 cursor is pointing to into register P3.
 */
 case OP_VColumn: {
-#if 0  /* local variables moved into u.cm */
   sqlite3_vtab *pVtab;
   const sqlite3_module *pModule;
   Mem *pDest;
   sqlite3_context sContext;
-#endif /* local variables moved into u.cm */
 
   VdbeCursor *pCur = p->apCsr[pOp->p1];
-  assert( pCur->pVtabCursor );
-  assert( pOp->p3>0 && pOp->p3<=p->nMem );
-  u.cm.pDest = &aMem[pOp->p3];
-  memAboutToChange(p, u.cm.pDest);
+  assert( pCur->eCurType==CURTYPE_VTAB );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  pDest = &aMem[pOp->p3];
+  memAboutToChange(p, pDest);
   if( pCur->nullRow ){
-    sqlite3VdbeMemSetNull(u.cm.pDest);
+    sqlite3VdbeMemSetNull(pDest);
     break;
   }
-  u.cm.pVtab = pCur->pVtabCursor->pVtab;
-  u.cm.pModule = u.cm.pVtab->pModule;
-  assert( u.cm.pModule->xColumn );
-  memset(&u.cm.sContext, 0, sizeof(u.cm.sContext));
-
-  /* The output cell may already have a buffer allocated. Move
-  ** the current contents to u.cm.sContext.s so in case the user-function
-  ** can use the already allocated buffer instead of allocating a
-  ** new one.
-  */
-  sqlite3VdbeMemMove(&u.cm.sContext.s, u.cm.pDest);
-  MemSetTypeFlag(&u.cm.sContext.s, MEM_Null);
-
-  rc = u.cm.pModule->xColumn(pCur->pVtabCursor, &u.cm.sContext, pOp->p2);
-  importVtabErrMsg(p, u.cm.pVtab);
-  if( u.cm.sContext.isError ){
-    rc = u.cm.sContext.isError;
-  }
-
-  /* Copy the result of the function to the P3 register. We
-  ** do this regardless of whether or not an error occurred to ensure any
-  ** dynamic allocation in u.cm.sContext.s (a Mem struct) is  released.
-  */
-  sqlite3VdbeChangeEncoding(&u.cm.sContext.s, encoding);
-  sqlite3VdbeMemMove(u.cm.pDest, &u.cm.sContext.s);
-  REGISTER_TRACE(pOp->p3, u.cm.pDest);
-  UPDATE_MAX_BLOBSIZE(u.cm.pDest);
-
-  if( sqlite3VdbeMemTooBig(u.cm.pDest) ){
+  pVtab = pCur->uc.pVCur->pVtab;
+  pModule = pVtab->pModule;
+  assert( pModule->xColumn );
+  memset(&sContext, 0, sizeof(sContext));
+  sContext.pOut = pDest;
+  MemSetTypeFlag(pDest, MEM_Null);
+  rc = pModule->xColumn(pCur->uc.pVCur, &sContext, pOp->p2);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  if( sContext.isError ){
+    rc = sContext.isError;
+  }
+  sqlite3VdbeChangeEncoding(pDest, encoding);
+  REGISTER_TRACE(pOp->p3, pDest);
+  UPDATE_MAX_BLOBSIZE(pDest);
+
+  if( sqlite3VdbeMemTooBig(pDest) ){
     goto too_big;
   }
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -69363,42 +83710,37 @@ case OP_VColumn: {
 ** the end of its result set, then fall through to the next instruction.
 */
 case OP_VNext: {   /* jump */
-#if 0  /* local variables moved into u.cn */
   sqlite3_vtab *pVtab;
   const sqlite3_module *pModule;
   int res;
   VdbeCursor *pCur;
-#endif /* local variables moved into u.cn */
 
-  u.cn.res = 0;
-  u.cn.pCur = p->apCsr[pOp->p1];
-  assert( u.cn.pCur->pVtabCursor );
-  if( u.cn.pCur->nullRow ){
+  res = 0;
+  pCur = p->apCsr[pOp->p1];
+  assert( pCur->eCurType==CURTYPE_VTAB );
+  if( pCur->nullRow ){
     break;
   }
-  u.cn.pVtab = u.cn.pCur->pVtabCursor->pVtab;
-  u.cn.pModule = u.cn.pVtab->pModule;
-  assert( u.cn.pModule->xNext );
+  pVtab = pCur->uc.pVCur->pVtab;
+  pModule = pVtab->pModule;
+  assert( pModule->xNext );
 
   /* Invoke the xNext() method of the module. There is no way for the
   ** underlying implementation to return an error if one occurs during
-  ** xNext(). Instead, if an error occurs, true is returned (indicating that
+  ** xNext(). Instead, if an error occurs, true is returned (indicating that 
   ** data is available) and the error code returned when xColumn or
   ** some other method is next invoked on the save virtual table cursor.
   */
-  p->inVtabMethod = 1;
-  rc = u.cn.pModule->xNext(u.cn.pCur->pVtabCursor);
-  p->inVtabMethod = 0;
-  importVtabErrMsg(p, u.cn.pVtab);
-  if( rc==SQLITE_OK ){
-    u.cn.res = u.cn.pModule->xEof(u.cn.pCur->pVtabCursor);
-  }
-
-  if( !u.cn.res ){
+  rc = pModule->xNext(pCur->uc.pVCur);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  if( rc ) goto abort_due_to_error;
+  res = pModule->xEof(pCur->uc.pVCur);
+  VdbeBranchTaken(!res,2);
+  if( !res ){
     /* If there is data, jump to P2 */
-    pc = pOp->p2 - 1;
+    goto jump_to_p2_and_check_for_interrupt;
   }
-  break;
+  goto check_for_interrupt;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -69410,32 +83752,32 @@ case OP_VNext: {   /* jump */
 ** in register P1 is passed as the zName argument to the xRename method.
 */
 case OP_VRename: {
-#if 0  /* local variables moved into u.co */
   sqlite3_vtab *pVtab;
   Mem *pName;
-#endif /* local variables moved into u.co */
-
-  u.co.pVtab = pOp->p4.pVtab->pVtab;
-  u.co.pName = &aMem[pOp->p1];
-  assert( u.co.pVtab->pModule->xRename );
-  assert( memIsValid(u.co.pName) );
-  REGISTER_TRACE(pOp->p1, u.co.pName);
-  assert( u.co.pName->flags & MEM_Str );
-  testcase( u.co.pName->enc==SQLITE_UTF8 );
-  testcase( u.co.pName->enc==SQLITE_UTF16BE );
-  testcase( u.co.pName->enc==SQLITE_UTF16LE );
-  rc = sqlite3VdbeChangeEncoding(u.co.pName, SQLITE_UTF8);
-  if( rc==SQLITE_OK ){
-    rc = u.co.pVtab->pModule->xRename(u.co.pVtab, u.co.pName->z);
-    importVtabErrMsg(p, u.co.pVtab);
-    p->expired = 0;
-  }
+
+  pVtab = pOp->p4.pVtab->pVtab;
+  pName = &aMem[pOp->p1];
+  assert( pVtab->pModule->xRename );
+  assert( memIsValid(pName) );
+  assert( p->readOnly==0 );
+  REGISTER_TRACE(pOp->p1, pName);
+  assert( pName->flags & MEM_Str );
+  testcase( pName->enc==SQLITE_UTF8 );
+  testcase( pName->enc==SQLITE_UTF16BE );
+  testcase( pName->enc==SQLITE_UTF16LE );
+  rc = sqlite3VdbeChangeEncoding(pName, SQLITE_UTF8);
+  if( rc ) goto abort_due_to_error;
+  rc = pVtab->pModule->xRename(pVtab, pName->z);
+  sqlite3VtabImportErrmsg(p, pVtab);
+  p->expired = 0;
+  if( rc ) goto abort_due_to_error;
   break;
 }
 #endif
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-/* Opcode: VUpdate P1 P2 P3 P4 *
+/* Opcode: VUpdate P1 P2 P3 P4 P5
+** Synopsis: data=r[P3@P2]
 **
 ** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
 ** This opcode invokes the corresponding xUpdate method. P2 values
@@ -69457,45 +83799,50 @@ case OP_VRename: {
 ** P1 is a boolean flag. If it is set to true and the xUpdate call
 ** is successful, then the value returned by sqlite3_last_insert_rowid() 
 ** is set to the value of the rowid for the row just inserted.
+**
+** P5 is the error actions (OE_Replace, OE_Fail, OE_Ignore, etc) to
+** apply in the case of a constraint failure on an insert or update.
 */
 case OP_VUpdate: {
-#if 0  /* local variables moved into u.cp */
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
+  const sqlite3_module *pModule;
   int nArg;
   int i;
   sqlite_int64 rowid;
   Mem **apArg;
   Mem *pX;
-#endif /* local variables moved into u.cp */
 
-  assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback
+  assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback 
        || pOp->p5==OE_Abort || pOp->p5==OE_Ignore || pOp->p5==OE_Replace
   );
-  u.cp.pVtab = pOp->p4.pVtab->pVtab;
-  u.cp.pModule = (sqlite3_module *)u.cp.pVtab->pModule;
-  u.cp.nArg = pOp->p2;
+  assert( p->readOnly==0 );
+  pVtab = pOp->p4.pVtab->pVtab;
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    goto abort_due_to_error;
+  }
+  pModule = pVtab->pModule;
+  nArg = pOp->p2;
   assert( pOp->p4type==P4_VTAB );
-  if( ALWAYS(u.cp.pModule->xUpdate) ){
+  if( ALWAYS(pModule->xUpdate) ){
     u8 vtabOnConflict = db->vtabOnConflict;
-    u.cp.apArg = p->apArg;
-    u.cp.pX = &aMem[pOp->p3];
-    for(u.cp.i=0; u.cp.i<u.cp.nArg; u.cp.i++){
-      assert( memIsValid(u.cp.pX) );
-      memAboutToChange(p, u.cp.pX);
-      sqlite3VdbeMemStoreType(u.cp.pX);
-      u.cp.apArg[u.cp.i] = u.cp.pX;
-      u.cp.pX++;
+    apArg = p->apArg;
+    pX = &aMem[pOp->p3];
+    for(i=0; i<nArg; i++){
+      assert( memIsValid(pX) );
+      memAboutToChange(p, pX);
+      apArg[i] = pX;
+      pX++;
     }
     db->vtabOnConflict = pOp->p5;
-    rc = u.cp.pModule->xUpdate(u.cp.pVtab, u.cp.nArg, u.cp.apArg, &u.cp.rowid);
+    rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);
     db->vtabOnConflict = vtabOnConflict;
-    importVtabErrMsg(p, u.cp.pVtab);
+    sqlite3VtabImportErrmsg(p, pVtab);
     if( rc==SQLITE_OK && pOp->p1 ){
-      assert( u.cp.nArg>1 && u.cp.apArg[0] && (u.cp.apArg[0]->flags&MEM_Null) );
-      db->lastRowid = lastRowid = u.cp.rowid;
+      assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
+      db->lastRowid = lastRowid = rowid;
     }
-    if( rc==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
+    if( (rc&0xff)==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
       if( pOp->p5==OE_Ignore ){
         rc = SQLITE_OK;
       }else{
@@ -69504,6 +83851,7 @@ case OP_VUpdate: {
     }else{
       p->nChange++;
     }
+    if( rc ) goto abort_due_to_error;
   }
   break;
 }
@@ -69514,7 +83862,8 @@ case OP_VUpdate: {
 **
 ** Write the current number of pages in database P1 to memory cell P2.
 */
-case OP_Pagecount: {            /* out2-prerelease */
+case OP_Pagecount: {            /* out2 */
+  pOut = out2Prerelease(p, pOp);
   pOut->u.i = sqlite3BtreeLastPage(db->aDb[pOp->p1].pBt);
   break;
 }
@@ -69530,10 +83879,11 @@ case OP_Pagecount: {            /* out2-prerelease */
 **
 ** Store the maximum page count after the change in register P2.
 */
-case OP_MaxPgcnt: {            /* out2-prerelease */
+case OP_MaxPgcnt: {            /* out2 */
   unsigned int newMax;
   Btree *pBt;
 
+  pOut = out2Prerelease(p, pOp);
   pBt = db->aDb[pOp->p1].pBt;
   newMax = 0;
   if( pOp->p3 ){
@@ -69546,34 +83896,93 @@ case OP_MaxPgcnt: {            /* out2-prerelease */
 #endif
 
 
-#ifndef SQLITE_OMIT_TRACE
-/* Opcode: Trace * * * P4 *
+/* Opcode: Init * P2 * P4 *
+** Synopsis:  Start at P2
+**
+** Programs contain a single instance of this opcode as the very first
+** opcode.
 **
 ** If tracing is enabled (by the sqlite3_trace()) interface, then
 ** the UTF-8 string contained in P4 is emitted on the trace callback.
+** Or if P4 is blank, use the string returned by sqlite3_sql().
+**
+** If P2 is not zero, jump to instruction P2.
 */
-case OP_Trace: {
-#if 0  /* local variables moved into u.cq */
+case OP_Init: {          /* jump */
   char *zTrace;
-  char *z;
-#endif /* local variables moved into u.cq */
 
-  if( db->xTrace && (u.cq.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0 ){
-    u.cq.z = sqlite3VdbeExpandSql(p, u.cq.zTrace);
-    db->xTrace(db->pTraceArg, u.cq.z);
-    sqlite3DbFree(db, u.cq.z);
+  /* If the P4 argument is not NULL, then it must be an SQL comment string.
+  ** The "--" string is broken up to prevent false-positives with srcck1.c.
+  **
+  ** This assert() provides evidence for:
+  ** EVIDENCE-OF: R-50676-09860 The callback can compute the same text that
+  ** would have been returned by the legacy sqlite3_trace() interface by
+  ** using the X argument when X begins with "--" and invoking
+  ** sqlite3_expanded_sql(P) otherwise.
+  */
+  assert( pOp->p4.z==0 || strncmp(pOp->p4.z, "-" "- ", 3)==0 );
+
+#ifndef SQLITE_OMIT_TRACE
+  if( (db->mTrace & (SQLITE_TRACE_STMT|SQLITE_TRACE_LEGACY))!=0
+   && !p->doingRerun
+   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
+  ){
+#ifndef SQLITE_OMIT_DEPRECATED
+    if( db->mTrace & SQLITE_TRACE_LEGACY ){
+      void (*x)(void*,const char*) = (void(*)(void*,const char*))db->xTrace;
+      char *z = sqlite3VdbeExpandSql(p, zTrace);
+      x(db->pTraceArg, z);
+      sqlite3_free(z);
+    }else
+#endif
+    {
+      (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, zTrace);
+    }
+  }
+#ifdef SQLITE_USE_FCNTL_TRACE
+  zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
+  if( zTrace ){
+    int i;
+    for(i=0; i<db->nDb; i++){
+      if( DbMaskTest(p->btreeMask, i)==0 ) continue;
+      sqlite3_file_control(db, db->aDb[i].zName, SQLITE_FCNTL_TRACE, zTrace);
+    }
   }
+#endif /* SQLITE_USE_FCNTL_TRACE */
 #ifdef SQLITE_DEBUG
   if( (db->flags & SQLITE_SqlTrace)!=0
-   && (u.cq.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
+   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
   ){
-    sqlite3DebugPrintf("SQL-trace: %s\n", u.cq.zTrace);
+    sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);
   }
 #endif /* SQLITE_DEBUG */
+#endif /* SQLITE_OMIT_TRACE */
+  if( pOp->p2 ) goto jump_to_p2;
   break;
 }
-#endif
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/* Opcode: CursorHint P1 * * P4 *
+**
+** Provide a hint to cursor P1 that it only needs to return rows that
+** satisfy the Expr in P4.  TK_REGISTER terms in the P4 expression refer
+** to values currently held in registers.  TK_COLUMN terms in the P4
+** expression refer to columns in the b-tree to which cursor P1 is pointing.
+*/
+case OP_CursorHint: {
+  VdbeCursor *pC;
+
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  assert( pOp->p4type==P4_EXPR );
+  pC = p->apCsr[pOp->p1];
+  if( pC ){
+    assert( pC->eCurType==CURTYPE_BTREE );
+    sqlite3BtreeCursorHint(pC->uc.pCursor, BTREE_HINT_RANGE,
+                           pOp->p4.pExpr, aMem);
+  }
+  break;
+}
+#endif /* SQLITE_ENABLE_CURSOR_HINTS */
 
 /* Opcode: Noop * * * * *
 **
@@ -69601,13 +84010,9 @@ default: {          /* This is really OP_Noop and OP_Explain */
 
 #ifdef VDBE_PROFILE
     {
-      u64 elapsed = sqlite3Hwtime() - start;
-      pOp->cycles += elapsed;
-      pOp->cnt++;
-#if 0
-        fprintf(stdout, "%10llu ", elapsed);
-        sqlite3VdbePrintOp(stdout, origPc, &aOp[origPc]);
-#endif
+      u64 endTime = sqlite3Hwtime();
+      if( endTime>start ) pOrigOp->cycles += endTime - start;
+      pOrigOp->cnt++;
     }
 #endif
 
@@ -69617,16 +84022,17 @@ default: {          /* This is really OP_Noop and OP_Explain */
     ** the evaluator loop.  So we can leave it out when NDEBUG is defined.
     */
 #ifndef NDEBUG
-    assert( pc>=-1 && pc<p->nOp );
+    assert( pOp>=&aOp[-1] && pOp<&aOp[p->nOp-1] );
 
 #ifdef SQLITE_DEBUG
-    if( p->trace ){
-      if( rc!=0 ) fprintf(p->trace,"rc=%d\n",rc);
-      if( pOp->opflags & (OPFLG_OUT2_PRERELEASE|OPFLG_OUT2) ){
-        registerTrace(p->trace, pOp->p2, &aMem[pOp->p2]);
+    if( db->flags & SQLITE_VdbeTrace ){
+      u8 opProperty = sqlite3OpcodeProperty[pOrigOp->opcode];
+      if( rc!=0 ) printf("rc=%d\n",rc);
+      if( opProperty & (OPFLG_OUT2) ){
+        registerTrace(pOrigOp->p2, &aMem[pOrigOp->p2]);
       }
-      if( pOp->opflags & OPFLG_OUT3 ){
-        registerTrace(p->trace, pOp->p3, &aMem[pOp->p3]);
+      if( opProperty & OPFLG_OUT3 ){
+        registerTrace(pOrigOp->p3, &aMem[pOrigOp->p3]);
       }
     }
 #endif  /* SQLITE_DEBUG */
@@ -69636,17 +84042,22 @@ default: {          /* This is really OP_Noop and OP_Explain */
   /* If we reach this point, it means that execution is finished with
   ** an error of some kind.
   */
-vdbe_error_halt:
+abort_due_to_error:
+  if( db->mallocFailed ) rc = SQLITE_NOMEM_BKPT;
   assert( rc );
+  if( p->zErrMsg==0 && rc!=SQLITE_IOERR_NOMEM ){
+    sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
+  }
   p->rc = rc;
+  sqlite3SystemError(db, rc);
   testcase( sqlite3GlobalConfig.xLog!=0 );
   sqlite3_log(rc, "statement aborts at %d: [%s] %s", 
-                   pc, p->zSql, p->zErrMsg);
+                   (int)(pOp - aOp), p->zSql, p->zErrMsg);
   sqlite3VdbeHalt(p);
-  if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
+  if( rc==SQLITE_IOERR_NOMEM ) sqlite3OomFault(db);
   rc = SQLITE_ERROR;
   if( resetSchemaOnFault>0 ){
-    sqlite3ResetInternalSchema(db, resetSchemaOnFault-1);
+    sqlite3ResetOneSchema(db, resetSchemaOnFault-1);
   }
 
   /* This is the only way out of this procedure.  We have to
@@ -69654,47 +84065,42 @@ vdbe_error_halt:
   ** top. */
 vdbe_return:
   db->lastRowid = lastRowid;
+  testcase( nVmStep>0 );
+  p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
   sqlite3VdbeLeave(p);
+  assert( rc!=SQLITE_OK || nExtraDelete==0 
+       || sqlite3_strlike("DELETE%",p->zSql,0)!=0 
+  );
   return rc;
 
   /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
   ** is encountered.
   */
 too_big:
-  sqlite3SetString(&p->zErrMsg, db, "string or blob too big");
+  sqlite3VdbeError(p, "string or blob too big");
   rc = SQLITE_TOOBIG;
-  goto vdbe_error_halt;
+  goto abort_due_to_error;
 
   /* Jump to here if a malloc() fails.
   */
 no_mem:
-  db->mallocFailed = 1;
-  sqlite3SetString(&p->zErrMsg, db, "out of memory");
-  rc = SQLITE_NOMEM;
-  goto vdbe_error_halt;
-
-  /* Jump to here for any other kind of fatal error.  The "rc" variable
-  ** should hold the error number.
-  */
-abort_due_to_error:
-  assert( p->zErrMsg==0 );
-  if( db->mallocFailed ) rc = SQLITE_NOMEM;
-  if( rc!=SQLITE_IOERR_NOMEM ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
-  }
-  goto vdbe_error_halt;
+  sqlite3OomFault(db);
+  sqlite3VdbeError(p, "out of memory");
+  rc = SQLITE_NOMEM_BKPT;
+  goto abort_due_to_error;
 
   /* Jump to here if the sqlite3_interrupt() API sets the interrupt
   ** flag.
   */
 abort_due_to_interrupt:
   assert( db->u1.isInterrupted );
-  rc = SQLITE_INTERRUPT;
+  rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;
   p->rc = rc;
-  sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
-  goto vdbe_error_halt;
+  sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
+  goto abort_due_to_error;
 }
 
+
 /************** End of vdbe.c ************************************************/
 /************** Begin file vdbeblob.c ****************************************/
 /*
@@ -69712,6 +84118,8 @@ abort_due_to_interrupt:
 ** This file contains code used to implement incremental BLOB I/O.
 */
 
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #ifndef SQLITE_OMIT_INCRBLOB
 
@@ -69727,6 +84135,8 @@ struct Incrblob {
   BtCursor *pCsr;         /* Cursor pointing at blob row */
   sqlite3_stmt *pStmt;    /* Statement holding cursor open */
   sqlite3 *db;            /* The associated database */
+  char *zDb;              /* Database name */
+  Table *pTab;            /* Table object */
 };
 
 
@@ -69761,7 +84171,8 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
 
   rc = sqlite3_step(p->pStmt);
   if( rc==SQLITE_ROW ){
-    u32 type = v->apCsr[0]->aType[p->iCol];
+    VdbeCursor *pC = v->apCsr[0];
+    u32 type = pC->aType[p->iCol];
     if( type<12 ){
       zErr = sqlite3MPrintf(p->db, "cannot open value of type %s",
           type==0?"null": type==7?"real": "integer"
@@ -69770,12 +84181,10 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
       sqlite3_finalize(p->pStmt);
       p->pStmt = 0;
     }else{
-      p->iOffset = v->apCsr[0]->aOffset[p->iCol];
+      p->iOffset = pC->aType[p->iCol + pC->nField];
       p->nByte = sqlite3VdbeSerialTypeLen(type);
-      p->pCsr =  v->apCsr[0]->pCursor;
-      sqlite3BtreeEnterCursor(p->pCsr);
-      sqlite3BtreeCacheOverflow(p->pCsr);
-      sqlite3BtreeLeaveCursor(p->pCsr);
+      p->pCsr =  pC->uc.pCursor;
+      sqlite3BtreeIncrblobCursor(p->pCsr);
     }
   }
 
@@ -69802,7 +84211,7 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
 /*
 ** Open a blob handle.
 */
-SQLITE_API int sqlite3_blob_open(
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_open(
   sqlite3* db,            /* The database connection */
   const char *zDb,        /* The attached database containing the blob */
   const char *zTable,     /* The table containing the blob */
@@ -69813,48 +84222,24 @@ SQLITE_API int sqlite3_blob_open(
 ){
   int nAttempt = 0;
   int iCol;               /* Index of zColumn in row-record */
-
-  /* This VDBE program seeks a btree cursor to the identified 
-  ** db/table/row entry. The reason for using a vdbe program instead
-  ** of writing code to use the b-tree layer directly is that the
-  ** vdbe program will take advantage of the various transaction,
-  ** locking and error handling infrastructure built into the vdbe.
-  **
-  ** After seeking the cursor, the vdbe executes an OP_ResultRow.
-  ** Code external to the Vdbe then "borrows" the b-tree cursor and
-  ** uses it to implement the blob_read(), blob_write() and 
-  ** blob_bytes() functions.
-  **
-  ** The sqlite3_blob_close() function finalizes the vdbe program,
-  ** which closes the b-tree cursor and (possibly) commits the 
-  ** transaction.
-  */
-  static const VdbeOpList openBlob[] = {
-    {OP_Transaction, 0, 0, 0},     /* 0: Start a transaction */
-    {OP_VerifyCookie, 0, 0, 0},    /* 1: Check the schema cookie */
-    {OP_TableLock, 0, 0, 0},       /* 2: Acquire a read or write lock */
-
-    /* One of the following two instructions is replaced by an OP_Noop. */
-    {OP_OpenRead, 0, 0, 0},        /* 3: Open cursor 0 for reading */
-    {OP_OpenWrite, 0, 0, 0},       /* 4: Open cursor 0 for read/write */
-
-    {OP_Variable, 1, 1, 1},        /* 5: Push the rowid to the stack */
-    {OP_NotExists, 0, 10, 1},      /* 6: Seek the cursor */
-    {OP_Column, 0, 0, 1},          /* 7  */
-    {OP_ResultRow, 1, 0, 0},       /* 8  */
-    {OP_Goto, 0, 5, 0},            /* 9  */
-    {OP_Close, 0, 0, 0},           /* 10 */
-    {OP_Halt, 0, 0, 0},            /* 11 */
-  };
-
   int rc = SQLITE_OK;
   char *zErr = 0;
   Table *pTab;
   Parse *pParse = 0;
   Incrblob *pBlob = 0;
 
-  flags = !!flags;                /* flags = (flags ? 1 : 0); */
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppBlob==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
   *ppBlob = 0;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zTable==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  flags = !!flags;                /* flags = (flags ? 1 : 0); */
 
   sqlite3_mutex_enter(db->mutex);
 
@@ -69875,6 +84260,10 @@ SQLITE_API int sqlite3_blob_open(
       pTab = 0;
       sqlite3ErrorMsg(pParse, "cannot open virtual table: %s", zTable);
     }
+    if( pTab && !HasRowid(pTab) ){
+      pTab = 0;
+      sqlite3ErrorMsg(pParse, "cannot open table without rowid: %s", zTable);
+    }
 #ifndef SQLITE_OMIT_VIEW
     if( pTab && pTab->pSelect ){
       pTab = 0;
@@ -69891,6 +84280,8 @@ SQLITE_API int sqlite3_blob_open(
       sqlite3BtreeLeaveAll(db);
       goto blob_open_out;
     }
+    pBlob->pTab = pTab;
+    pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zName;
 
     /* Now search pTab for the exact column. */
     for(iCol=0; iCol<pTab->nCol; iCol++) {
@@ -69932,8 +84323,9 @@ SQLITE_API int sqlite3_blob_open(
 #endif
       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
         int j;
-        for(j=0; j<pIdx->nColumn; j++){
-          if( pIdx->aiColumn[j]==iCol ){
+        for(j=0; j<pIdx->nKeyCol; j++){
+          /* FIXME: Be smarter about indexes that use expressions */
+          if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==XN_EXPR ){
             zFault = "indexed";
           }
         }
@@ -69947,53 +84339,81 @@ SQLITE_API int sqlite3_blob_open(
       }
     }
 
-    pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(db);
+    pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(pParse);
     assert( pBlob->pStmt || db->mallocFailed );
     if( pBlob->pStmt ){
+      
+      /* This VDBE program seeks a btree cursor to the identified 
+      ** db/table/row entry. The reason for using a vdbe program instead
+      ** of writing code to use the b-tree layer directly is that the
+      ** vdbe program will take advantage of the various transaction,
+      ** locking and error handling infrastructure built into the vdbe.
+      **
+      ** After seeking the cursor, the vdbe executes an OP_ResultRow.
+      ** Code external to the Vdbe then "borrows" the b-tree cursor and
+      ** uses it to implement the blob_read(), blob_write() and 
+      ** blob_bytes() functions.
+      **
+      ** The sqlite3_blob_close() function finalizes the vdbe program,
+      ** which closes the b-tree cursor and (possibly) commits the 
+      ** transaction.
+      */
+      static const int iLn = VDBE_OFFSET_LINENO(2);
+      static const VdbeOpList openBlob[] = {
+        {OP_TableLock,      0, 0, 0},  /* 0: Acquire a read or write lock */
+        {OP_OpenRead,       0, 0, 0},  /* 1: Open a cursor */
+        {OP_Variable,       1, 1, 0},  /* 2: Move ?1 into reg[1] */
+        {OP_NotExists,      0, 7, 1},  /* 3: Seek the cursor */
+        {OP_Column,         0, 0, 1},  /* 4  */
+        {OP_ResultRow,      1, 0, 0},  /* 5  */
+        {OP_Goto,           0, 2, 0},  /* 6  */
+        {OP_Close,          0, 0, 0},  /* 7  */
+        {OP_Halt,           0, 0, 0},  /* 8  */
+      };
       Vdbe *v = (Vdbe *)pBlob->pStmt;
       int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+      VdbeOp *aOp;
 
-      sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
-
-
-      /* Configure the OP_Transaction */
-      sqlite3VdbeChangeP1(v, 0, iDb);
-      sqlite3VdbeChangeP2(v, 0, flags);
-
-      /* Configure the OP_VerifyCookie */
-      sqlite3VdbeChangeP1(v, 1, iDb);
-      sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);
-      sqlite3VdbeChangeP3(v, 1, pTab->pSchema->iGeneration);
+      sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags, 
+                           pTab->pSchema->schema_cookie,
+                           pTab->pSchema->iGeneration);
+      sqlite3VdbeChangeP5(v, 1);     
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);
 
       /* Make sure a mutex is held on the table to be accessed */
       sqlite3VdbeUsesBtree(v, iDb); 
 
-      /* Configure the OP_TableLock instruction */
+      if( db->mallocFailed==0 ){
+        assert( aOp!=0 );
+        /* Configure the OP_TableLock instruction */
 #ifdef SQLITE_OMIT_SHARED_CACHE
-      sqlite3VdbeChangeToNoop(v, 2);
+        aOp[0].opcode = OP_Noop;
 #else
-      sqlite3VdbeChangeP1(v, 2, iDb);
-      sqlite3VdbeChangeP2(v, 2, pTab->tnum);
-      sqlite3VdbeChangeP3(v, 2, flags);
-      sqlite3VdbeChangeP4(v, 2, pTab->zName, P4_TRANSIENT);
-#endif
-
-      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
-      ** parameter of the other to pTab->tnum.  */
-      sqlite3VdbeChangeToNoop(v, 4 - flags);
-      sqlite3VdbeChangeP2(v, 3 + flags, pTab->tnum);
-      sqlite3VdbeChangeP3(v, 3 + flags, iDb);
-
-      /* Configure the number of columns. Configure the cursor to
-      ** think that the table has one more column than it really
-      ** does. An OP_Column to retrieve this imaginary column will
-      ** always return an SQL NULL. This is useful because it means
-      ** we can invoke OP_Column to fill in the vdbe cursors type 
-      ** and offset cache without causing any IO.
-      */
-      sqlite3VdbeChangeP4(v, 3+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
-      sqlite3VdbeChangeP2(v, 7, pTab->nCol);
-      if( !db->mallocFailed ){
+        aOp[0].p1 = iDb;
+        aOp[0].p2 = pTab->tnum;
+        aOp[0].p3 = flags;
+        sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
+      }
+      if( db->mallocFailed==0 ){
+#endif
+
+        /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
+        ** parameter of the other to pTab->tnum.  */
+        if( flags ) aOp[1].opcode = OP_OpenWrite;
+        aOp[1].p2 = pTab->tnum;
+        aOp[1].p3 = iDb;   
+
+        /* Configure the number of columns. Configure the cursor to
+        ** think that the table has one more column than it really
+        ** does. An OP_Column to retrieve this imaginary column will
+        ** always return an SQL NULL. This is useful because it means
+        ** we can invoke OP_Column to fill in the vdbe cursors type 
+        ** and offset cache without causing any IO.
+        */
+        aOp[1].p4type = P4_INT32;
+        aOp[1].p4.i = pTab->nCol+1;
+        aOp[4].p2 = pTab->nCol;
+
         pParse->nVar = 1;
         pParse->nMem = 1;
         pParse->nTab = 1;
@@ -70010,7 +84430,7 @@ SQLITE_API int sqlite3_blob_open(
     }
     sqlite3_bind_int64(pBlob->pStmt, 1, iRow);
     rc = blobSeekToRow(pBlob, iRow, &zErr);
-  } while( (++nAttempt)<5 && rc==SQLITE_SCHEMA );
+  } while( (++nAttempt)<SQLITE_MAX_SCHEMA_RETRY && rc==SQLITE_SCHEMA );
 
 blob_open_out:
   if( rc==SQLITE_OK && db->mallocFailed==0 ){
@@ -70019,8 +84439,9 @@ blob_open_out:
     if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);
     sqlite3DbFree(db, pBlob);
   }
-  sqlite3Error(db, rc, (zErr ? "%s" : 0), zErr);
+  sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);
   sqlite3DbFree(db, zErr);
+  sqlite3ParserReset(pParse);
   sqlite3StackFree(db, pParse);
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
@@ -70031,7 +84452,7 @@ blob_open_out:
 ** Close a blob handle that was previously created using
 ** sqlite3_blob_open().
 */
-SQLITE_API int sqlite3_blob_close(sqlite3_blob *pBlob){
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *pBlob){
   Incrblob *p = (Incrblob *)pBlob;
   int rc;
   sqlite3 *db;
@@ -70068,10 +84489,9 @@ static int blobReadWrite(
   sqlite3_mutex_enter(db->mutex);
   v = (Vdbe*)p->pStmt;
 
-  if( n<0 || iOffset<0 || (iOffset+n)>p->nByte ){
+  if( n<0 || iOffset<0 || ((sqlite3_int64)iOffset+n)>p->nByte ){
     /* Request is out of range. Return a transient error. */
     rc = SQLITE_ERROR;
-    sqlite3Error(db, SQLITE_ERROR, 0);
   }else if( v==0 ){
     /* If there is no statement handle, then the blob-handle has
     ** already been invalidated. Return SQLITE_ABORT in this case.
@@ -70083,16 +84503,40 @@ static int blobReadWrite(
     */
     assert( db == v->db );
     sqlite3BtreeEnterCursor(p->pCsr);
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+    if( xCall==sqlite3BtreePutData && db->xPreUpdateCallback ){
+      /* If a pre-update hook is registered and this is a write cursor, 
+      ** invoke it here. 
+      ** 
+      ** TODO: The preupdate-hook is passed SQLITE_DELETE, even though this
+      ** operation should really be an SQLITE_UPDATE. This is probably
+      ** incorrect, but is convenient because at this point the new.* values 
+      ** are not easily obtainable. And for the sessions module, an 
+      ** SQLITE_UPDATE where the PK columns do not change is handled in the 
+      ** same way as an SQLITE_DELETE (the SQLITE_DELETE code is actually
+      ** slightly more efficient). Since you cannot write to a PK column
+      ** using the incremental-blob API, this works. For the sessions module
+      ** anyhow.
+      */
+      sqlite3_int64 iKey;
+      iKey = sqlite3BtreeIntegerKey(p->pCsr);
+      sqlite3VdbePreUpdateHook(
+          v, v->apCsr[0], SQLITE_DELETE, p->zDb, p->pTab, iKey, -1
+      );
+    }
+#endif
+
     rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
     sqlite3BtreeLeaveCursor(p->pCsr);
     if( rc==SQLITE_ABORT ){
       sqlite3VdbeFinalize(v);
       p->pStmt = 0;
     }else{
-      db->errCode = rc;
       v->rc = rc;
     }
   }
+  sqlite3Error(db, rc);
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
   return rc;
@@ -70101,14 +84545,14 @@ static int blobReadWrite(
 /*
 ** Read data from a blob handle.
 */
-SQLITE_API int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
   return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreeData);
 }
 
 /*
 ** Write data to a blob handle.
 */
-SQLITE_API int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){
   return blobReadWrite(pBlob, (void *)z, n, iOffset, sqlite3BtreePutData);
 }
 
@@ -70118,7 +84562,7 @@ SQLITE_API int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int
 ** The Incrblob.nByte field is fixed for the lifetime of the Incrblob
 ** so no mutex is required for access.
 */
-SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *pBlob){
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *pBlob){
   Incrblob *p = (Incrblob *)pBlob;
   return (p && p->pStmt) ? p->nByte : 0;
 }
@@ -70133,7 +84577,7 @@ SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *pBlob){
 ** subsequent calls to sqlite3_blob_xxx() functions (except blob_close()) 
 ** immediately return SQLITE_ABORT.
 */
-SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
+SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
   int rc;
   Incrblob *p = (Incrblob *)pBlob;
   sqlite3 *db;
@@ -70151,7 +84595,7 @@ SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
     char *zErr;
     rc = blobSeekToRow(p, iRow, &zErr);
     if( rc!=SQLITE_OK ){
-      sqlite3Error(db, rc, (zErr ? "%s" : 0), zErr);
+      sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);
       sqlite3DbFree(db, zErr);
     }
     assert( rc!=SQLITE_SCHEMA );
@@ -70168,7 +84612,7 @@ SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
 /************** End of vdbeblob.c ********************************************/
 /************** Begin file vdbesort.c ****************************************/
 /*
-** 2011 July 9
+** 2011-07-09
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -70179,77 +84623,240 @@ SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){
 **
 *************************************************************************
 ** This file contains code for the VdbeSorter object, used in concert with
-** a VdbeCursor to sort large numbers of keys (as may be required, for
-** example, by CREATE INDEX statements on tables too large to fit in main
-** memory).
+** a VdbeCursor to sort large numbers of keys for CREATE INDEX statements
+** or by SELECT statements with ORDER BY clauses that cannot be satisfied
+** using indexes and without LIMIT clauses.
+**
+** The VdbeSorter object implements a multi-threaded external merge sort
+** algorithm that is efficient even if the number of elements being sorted
+** exceeds the available memory.
+**
+** Here is the (internal, non-API) interface between this module and the
+** rest of the SQLite system:
+**
+**    sqlite3VdbeSorterInit()       Create a new VdbeSorter object.
+**
+**    sqlite3VdbeSorterWrite()      Add a single new row to the VdbeSorter
+**                                  object.  The row is a binary blob in the
+**                                  OP_MakeRecord format that contains both
+**                                  the ORDER BY key columns and result columns
+**                                  in the case of a SELECT w/ ORDER BY, or
+**                                  the complete record for an index entry
+**                                  in the case of a CREATE INDEX.
+**
+**    sqlite3VdbeSorterRewind()     Sort all content previously added.
+**                                  Position the read cursor on the
+**                                  first sorted element.
+**
+**    sqlite3VdbeSorterNext()       Advance the read cursor to the next sorted
+**                                  element.
+**
+**    sqlite3VdbeSorterRowkey()     Return the complete binary blob for the
+**                                  row currently under the read cursor.
+**
+**    sqlite3VdbeSorterCompare()    Compare the binary blob for the row
+**                                  currently under the read cursor against
+**                                  another binary blob X and report if
+**                                  X is strictly less than the read cursor.
+**                                  Used to enforce uniqueness in a
+**                                  CREATE UNIQUE INDEX statement.
+**
+**    sqlite3VdbeSorterClose()      Close the VdbeSorter object and reclaim
+**                                  all resources.
+**
+**    sqlite3VdbeSorterReset()      Refurbish the VdbeSorter for reuse.  This
+**                                  is like Close() followed by Init() only
+**                                  much faster.
+**
+** The interfaces above must be called in a particular order.  Write() can 
+** only occur in between Init()/Reset() and Rewind().  Next(), Rowkey(), and
+** Compare() can only occur in between Rewind() and Close()/Reset(). i.e.
+**
+**   Init()
+**   for each record: Write()
+**   Rewind()
+**     Rowkey()/Compare()
+**   Next() 
+**   Close()
+**
+** Algorithm:
+**
+** Records passed to the sorter via calls to Write() are initially held 
+** unsorted in main memory. Assuming the amount of memory used never exceeds
+** a threshold, when Rewind() is called the set of records is sorted using
+** an in-memory merge sort. In this case, no temporary files are required
+** and subsequent calls to Rowkey(), Next() and Compare() read records 
+** directly from main memory.
+**
+** If the amount of space used to store records in main memory exceeds the
+** threshold, then the set of records currently in memory are sorted and
+** written to a temporary file in "Packed Memory Array" (PMA) format.
+** A PMA created at this point is known as a "level-0 PMA". Higher levels
+** of PMAs may be created by merging existing PMAs together - for example
+** merging two or more level-0 PMAs together creates a level-1 PMA.
+**
+** The threshold for the amount of main memory to use before flushing 
+** records to a PMA is roughly the same as the limit configured for the
+** page-cache of the main database. Specifically, the threshold is set to 
+** the value returned by "PRAGMA main.page_size" multipled by 
+** that returned by "PRAGMA main.cache_size", in bytes.
+**
+** If the sorter is running in single-threaded mode, then all PMAs generated
+** are appended to a single temporary file. Or, if the sorter is running in
+** multi-threaded mode then up to (N+1) temporary files may be opened, where
+** N is the configured number of worker threads. In this case, instead of
+** sorting the records and writing the PMA to a temporary file itself, the
+** calling thread usually launches a worker thread to do so. Except, if
+** there are already N worker threads running, the main thread does the work
+** itself.
+**
+** The sorter is running in multi-threaded mode if (a) the library was built
+** with pre-processor symbol SQLITE_MAX_WORKER_THREADS set to a value greater
+** than zero, and (b) worker threads have been enabled at runtime by calling
+** "PRAGMA threads=N" with some value of N greater than 0.
+**
+** When Rewind() is called, any data remaining in memory is flushed to a 
+** final PMA. So at this point the data is stored in some number of sorted
+** PMAs within temporary files on disk.
+**
+** If there are fewer than SORTER_MAX_MERGE_COUNT PMAs in total and the
+** sorter is running in single-threaded mode, then these PMAs are merged
+** incrementally as keys are retreived from the sorter by the VDBE.  The
+** MergeEngine object, described in further detail below, performs this
+** merge.
+**
+** Or, if running in multi-threaded mode, then a background thread is
+** launched to merge the existing PMAs. Once the background thread has
+** merged T bytes of data into a single sorted PMA, the main thread 
+** begins reading keys from that PMA while the background thread proceeds
+** with merging the next T bytes of data. And so on.
+**
+** Parameter T is set to half the value of the memory threshold used 
+** by Write() above to determine when to create a new PMA.
+**
+** If there are more than SORTER_MAX_MERGE_COUNT PMAs in total when 
+** Rewind() is called, then a hierarchy of incremental-merges is used. 
+** First, T bytes of data from the first SORTER_MAX_MERGE_COUNT PMAs on 
+** disk are merged together. Then T bytes of data from the second set, and
+** so on, such that no operation ever merges more than SORTER_MAX_MERGE_COUNT
+** PMAs at a time. This done is to improve locality.
+**
+** If running in multi-threaded mode and there are more than
+** SORTER_MAX_MERGE_COUNT PMAs on disk when Rewind() is called, then more
+** than one background thread may be created. Specifically, there may be
+** one background thread for each temporary file on disk, and one background
+** thread to merge the output of each of the others to a single PMA for
+** the main thread to read from.
+*/
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
+
+/* 
+** If SQLITE_DEBUG_SORTER_THREADS is defined, this module outputs various
+** messages to stderr that may be helpful in understanding the performance
+** characteristics of the sorter in multi-threaded mode.
 */
+#if 0
+# define SQLITE_DEBUG_SORTER_THREADS 1
+#endif
 
+/*
+** Hard-coded maximum amount of data to accumulate in memory before flushing
+** to a level 0 PMA. The purpose of this limit is to prevent various integer
+** overflows. 512MiB.
+*/
+#define SQLITE_MAX_PMASZ    (1<<29)
 
-#ifndef SQLITE_OMIT_MERGE_SORT
+/*
+** Private objects used by the sorter
+*/
+typedef struct MergeEngine MergeEngine;     /* Merge PMAs together */
+typedef struct PmaReader PmaReader;         /* Incrementally read one PMA */
+typedef struct PmaWriter PmaWriter;         /* Incrementally write one PMA */
+typedef struct SorterRecord SorterRecord;   /* A record being sorted */
+typedef struct SortSubtask SortSubtask;     /* A sub-task in the sort process */
+typedef struct SorterFile SorterFile;       /* Temporary file object wrapper */
+typedef struct SorterList SorterList;       /* In-memory list of records */
+typedef struct IncrMerger IncrMerger;       /* Read & merge multiple PMAs */
 
-typedef struct VdbeSorterIter VdbeSorterIter;
-typedef struct SorterRecord SorterRecord;
+/*
+** A container for a temp file handle and the current amount of data 
+** stored in the file.
+*/
+struct SorterFile {
+  sqlite3_file *pFd;              /* File handle */
+  i64 iEof;                       /* Bytes of data stored in pFd */
+};
 
 /*
-** NOTES ON DATA STRUCTURE USED FOR N-WAY MERGES:
+** An in-memory list of objects to be sorted.
 **
-** As keys are added to the sorter, they are written to disk in a series
-** of sorted packed-memory-arrays (PMAs). The size of each PMA is roughly
-** the same as the cache-size allowed for temporary databases. In order
-** to allow the caller to extract keys from the sorter in sorted order,
-** all PMAs currently stored on disk must be merged together. This comment
-** describes the data structure used to do so. The structure supports 
-** merging any number of arrays in a single pass with no redundant comparison 
-** operations.
+** If aMemory==0 then each object is allocated separately and the objects
+** are connected using SorterRecord.u.pNext.  If aMemory!=0 then all objects
+** are stored in the aMemory[] bulk memory, one right after the other, and
+** are connected using SorterRecord.u.iNext.
+*/
+struct SorterList {
+  SorterRecord *pList;            /* Linked list of records */
+  u8 *aMemory;                    /* If non-NULL, bulk memory to hold pList */
+  int szPMA;                      /* Size of pList as PMA in bytes */
+};
+
+/*
+** The MergeEngine object is used to combine two or more smaller PMAs into
+** one big PMA using a merge operation.  Separate PMAs all need to be
+** combined into one big PMA in order to be able to step through the sorted
+** records in order.
 **
-** The aIter[] array contains an iterator for each of the PMAs being merged.
-** An aIter[] iterator either points to a valid key or else is at EOF. For 
-** the purposes of the paragraphs below, we assume that the array is actually 
-** N elements in size, where N is the smallest power of 2 greater to or equal 
-** to the number of iterators being merged. The extra aIter[] elements are 
-** treated as if they are empty (always at EOF).
+** The aReadr[] array contains a PmaReader object for each of the PMAs being
+** merged.  An aReadr[] object either points to a valid key or else is at EOF.
+** ("EOF" means "End Of File".  When aReadr[] is at EOF there is no more data.)
+** For the purposes of the paragraphs below, we assume that the array is
+** actually N elements in size, where N is the smallest power of 2 greater
+** to or equal to the number of PMAs being merged. The extra aReadr[] elements
+** are treated as if they are empty (always at EOF).
 **
 ** The aTree[] array is also N elements in size. The value of N is stored in
-** the VdbeSorter.nTree variable.
+** the MergeEngine.nTree variable.
 **
 ** The final (N/2) elements of aTree[] contain the results of comparing
-** pairs of iterator keys together. Element i contains the result of 
-** comparing aIter[2*i-N] and aIter[2*i-N+1]. Whichever key is smaller, the
+** pairs of PMA keys together. Element i contains the result of 
+** comparing aReadr[2*i-N] and aReadr[2*i-N+1]. Whichever key is smaller, the
 ** aTree element is set to the index of it. 
 **
 ** For the purposes of this comparison, EOF is considered greater than any
 ** other key value. If the keys are equal (only possible with two EOF
 ** values), it doesn't matter which index is stored.
 **
-** The (N/4) elements of aTree[] that preceed the final (N/2) described 
-** above contains the index of the smallest of each block of 4 iterators.
-** And so on. So that aTree[1] contains the index of the iterator that 
+** The (N/4) elements of aTree[] that precede the final (N/2) described 
+** above contains the index of the smallest of each block of 4 PmaReaders
+** And so on. So that aTree[1] contains the index of the PmaReader that 
 ** currently points to the smallest key value. aTree[0] is unused.
 **
 ** Example:
 **
-**     aIter[0] -> Banana
-**     aIter[1] -> Feijoa
-**     aIter[2] -> Elderberry
-**     aIter[3] -> Currant
-**     aIter[4] -> Grapefruit
-**     aIter[5] -> Apple
-**     aIter[6] -> Durian
-**     aIter[7] -> EOF
+**     aReadr[0] -> Banana
+**     aReadr[1] -> Feijoa
+**     aReadr[2] -> Elderberry
+**     aReadr[3] -> Currant
+**     aReadr[4] -> Grapefruit
+**     aReadr[5] -> Apple
+**     aReadr[6] -> Durian
+**     aReadr[7] -> EOF
 **
 **     aTree[] = { X, 5   0, 5    0, 3, 5, 6 }
 **
 ** The current element is "Apple" (the value of the key indicated by 
-** iterator 5). When the Next() operation is invoked, iterator 5 will
+** PmaReader 5). When the Next() operation is invoked, PmaReader 5 will
 ** be advanced to the next key in its segment. Say the next key is
 ** "Eggplant":
 **
-**     aIter[5] -> Eggplant
+**     aReadr[5] -> Eggplant
 **
-** The contents of aTree[] are updated first by comparing the new iterator
-** 5 key to the current key of iterator 4 (still "Grapefruit"). The iterator
+** The contents of aTree[] are updated first by comparing the new PmaReader
+** 5 key to the current key of PmaReader 4 (still "Grapefruit"). The PmaReader
 ** 5 value is still smaller, so aTree[6] is set to 5. And so on up the tree.
-** The value of iterator 6 - "Durian" - is now smaller than that of iterator
+** The value of PmaReader 6 - "Durian" - is now smaller than that of PmaReader
 ** 5, so aTree[3] is set to 6. Key 0 is smaller than key 6 (Banana<Durian),
 ** so the value written into element 1 of the array is 0. As follows:
 **
@@ -70259,323 +84866,777 @@ typedef struct SorterRecord SorterRecord;
 ** key comparison operations are required, where N is the number of segments
 ** being merged (rounded up to the next power of 2).
 */
+struct MergeEngine {
+  int nTree;                 /* Used size of aTree/aReadr (power of 2) */
+  SortSubtask *pTask;        /* Used by this thread only */
+  int *aTree;                /* Current state of incremental merge */
+  PmaReader *aReadr;         /* Array of PmaReaders to merge data from */
+};
+
+/*
+** This object represents a single thread of control in a sort operation.
+** Exactly VdbeSorter.nTask instances of this object are allocated
+** as part of each VdbeSorter object. Instances are never allocated any
+** other way. VdbeSorter.nTask is set to the number of worker threads allowed
+** (see SQLITE_CONFIG_WORKER_THREADS) plus one (the main thread).  Thus for
+** single-threaded operation, there is exactly one instance of this object
+** and for multi-threaded operation there are two or more instances.
+**
+** Essentially, this structure contains all those fields of the VdbeSorter
+** structure for which each thread requires a separate instance. For example,
+** each thread requries its own UnpackedRecord object to unpack records in
+** as part of comparison operations.
+**
+** Before a background thread is launched, variable bDone is set to 0. Then, 
+** right before it exits, the thread itself sets bDone to 1. This is used for 
+** two purposes:
+**
+**   1. When flushing the contents of memory to a level-0 PMA on disk, to
+**      attempt to select a SortSubtask for which there is not already an
+**      active background thread (since doing so causes the main thread
+**      to block until it finishes).
+**
+**   2. If SQLITE_DEBUG_SORTER_THREADS is defined, to determine if a call
+**      to sqlite3ThreadJoin() is likely to block. Cases that are likely to
+**      block provoke debugging output.
+**
+** In both cases, the effects of the main thread seeing (bDone==0) even
+** after the thread has finished are not dire. So we don't worry about
+** memory barriers and such here.
+*/
+typedef int (*SorterCompare)(SortSubtask*,int*,const void*,int,const void*,int);
+struct SortSubtask {
+  SQLiteThread *pThread;          /* Background thread, if any */
+  int bDone;                      /* Set if thread is finished but not joined */
+  VdbeSorter *pSorter;            /* Sorter that owns this sub-task */
+  UnpackedRecord *pUnpacked;      /* Space to unpack a record */
+  SorterList list;                /* List for thread to write to a PMA */
+  int nPMA;                       /* Number of PMAs currently in file */
+  SorterCompare xCompare;         /* Compare function to use */
+  SorterFile file;                /* Temp file for level-0 PMAs */
+  SorterFile file2;               /* Space for other PMAs */
+};
+
+
+/*
+** Main sorter structure. A single instance of this is allocated for each 
+** sorter cursor created by the VDBE.
+**
+** mxKeysize:
+**   As records are added to the sorter by calls to sqlite3VdbeSorterWrite(),
+**   this variable is updated so as to be set to the size on disk of the
+**   largest record in the sorter.
+*/
 struct VdbeSorter {
-  int nInMemory;                  /* Current size of pRecord list as PMA */
-  int nTree;                      /* Used size of aTree/aIter (power of 2) */
-  VdbeSorterIter *aIter;          /* Array of iterators to merge */
-  int *aTree;                     /* Current state of incremental merge */
-  i64 iWriteOff;                  /* Current write offset within file pTemp1 */
-  i64 iReadOff;                   /* Current read offset within file pTemp1 */
-  sqlite3_file *pTemp1;           /* PMA file 1 */
-  int nPMA;                       /* Number of PMAs stored in pTemp1 */
-  SorterRecord *pRecord;          /* Head of in-memory record list */
   int mnPmaSize;                  /* Minimum PMA size, in bytes */
   int mxPmaSize;                  /* Maximum PMA size, in bytes.  0==no limit */
-  UnpackedRecord *pUnpacked;      /* Used to unpack keys */
+  int mxKeysize;                  /* Largest serialized key seen so far */
+  int pgsz;                       /* Main database page size */
+  PmaReader *pReader;             /* Readr data from here after Rewind() */
+  MergeEngine *pMerger;           /* Or here, if bUseThreads==0 */
+  sqlite3 *db;                    /* Database connection */
+  KeyInfo *pKeyInfo;              /* How to compare records */
+  UnpackedRecord *pUnpacked;      /* Used by VdbeSorterCompare() */
+  SorterList list;                /* List of in-memory records */
+  int iMemory;                    /* Offset of free space in list.aMemory */
+  int nMemory;                    /* Size of list.aMemory allocation in bytes */
+  u8 bUsePMA;                     /* True if one or more PMAs created */
+  u8 bUseThreads;                 /* True to use background threads */
+  u8 iPrev;                       /* Previous thread used to flush PMA */
+  u8 nTask;                       /* Size of aTask[] array */
+  u8 typeMask;
+  SortSubtask aTask[1];           /* One or more subtasks */
+};
+
+#define SORTER_TYPE_INTEGER 0x01
+#define SORTER_TYPE_TEXT    0x02
+
+/*
+** An instance of the following object is used to read records out of a
+** PMA, in sorted order.  The next key to be read is cached in nKey/aKey.
+** aKey might point into aMap or into aBuffer.  If neither of those locations
+** contain a contiguous representation of the key, then aAlloc is allocated
+** and the key is copied into aAlloc and aKey is made to poitn to aAlloc.
+**
+** pFd==0 at EOF.
+*/
+struct PmaReader {
+  i64 iReadOff;               /* Current read offset */
+  i64 iEof;                   /* 1 byte past EOF for this PmaReader */
+  int nAlloc;                 /* Bytes of space at aAlloc */
+  int nKey;                   /* Number of bytes in key */
+  sqlite3_file *pFd;          /* File handle we are reading from */
+  u8 *aAlloc;                 /* Space for aKey if aBuffer and pMap wont work */
+  u8 *aKey;                   /* Pointer to current key */
+  u8 *aBuffer;                /* Current read buffer */
+  int nBuffer;                /* Size of read buffer in bytes */
+  u8 *aMap;                   /* Pointer to mapping of entire file */
+  IncrMerger *pIncr;          /* Incremental merger */
 };
 
 /*
-** The following type is an iterator for a PMA. It caches the current key in 
-** variables nKey/aKey. If the iterator is at EOF, pFile==0.
+** Normally, a PmaReader object iterates through an existing PMA stored 
+** within a temp file. However, if the PmaReader.pIncr variable points to
+** an object of the following type, it may be used to iterate/merge through
+** multiple PMAs simultaneously.
+**
+** There are two types of IncrMerger object - single (bUseThread==0) and 
+** multi-threaded (bUseThread==1). 
+**
+** A multi-threaded IncrMerger object uses two temporary files - aFile[0] 
+** and aFile[1]. Neither file is allowed to grow to more than mxSz bytes in 
+** size. When the IncrMerger is initialized, it reads enough data from 
+** pMerger to populate aFile[0]. It then sets variables within the 
+** corresponding PmaReader object to read from that file and kicks off 
+** a background thread to populate aFile[1] with the next mxSz bytes of 
+** sorted record data from pMerger. 
+**
+** When the PmaReader reaches the end of aFile[0], it blocks until the
+** background thread has finished populating aFile[1]. It then exchanges
+** the contents of the aFile[0] and aFile[1] variables within this structure,
+** sets the PmaReader fields to read from the new aFile[0] and kicks off
+** another background thread to populate the new aFile[1]. And so on, until
+** the contents of pMerger are exhausted.
+**
+** A single-threaded IncrMerger does not open any temporary files of its
+** own. Instead, it has exclusive access to mxSz bytes of space beginning
+** at offset iStartOff of file pTask->file2. And instead of using a 
+** background thread to prepare data for the PmaReader, with a single
+** threaded IncrMerger the allocate part of pTask->file2 is "refilled" with
+** keys from pMerger by the calling thread whenever the PmaReader runs out
+** of data.
+*/
+struct IncrMerger {
+  SortSubtask *pTask;             /* Task that owns this merger */
+  MergeEngine *pMerger;           /* Merge engine thread reads data from */
+  i64 iStartOff;                  /* Offset to start writing file at */
+  int mxSz;                       /* Maximum bytes of data to store */
+  int bEof;                       /* Set to true when merge is finished */
+  int bUseThread;                 /* True to use a bg thread for this object */
+  SorterFile aFile[2];            /* aFile[0] for reading, [1] for writing */
+};
+
+/*
+** An instance of this object is used for writing a PMA.
+**
+** The PMA is written one record at a time.  Each record is of an arbitrary
+** size.  But I/O is more efficient if it occurs in page-sized blocks where
+** each block is aligned on a page boundary.  This object caches writes to
+** the PMA so that aligned, page-size blocks are written.
 */
-struct VdbeSorterIter {
-  i64 iReadOff;                   /* Current read offset */
-  i64 iEof;                       /* 1 byte past EOF for this iterator */
-  sqlite3_file *pFile;            /* File iterator is reading from */
-  int nAlloc;                     /* Bytes of space at aAlloc */
-  u8 *aAlloc;                     /* Allocated space */
-  int nKey;                       /* Number of bytes in key */
-  u8 *aKey;                       /* Pointer to current key */
+struct PmaWriter {
+  int eFWErr;                     /* Non-zero if in an error state */
+  u8 *aBuffer;                    /* Pointer to write buffer */
+  int nBuffer;                    /* Size of write buffer in bytes */
+  int iBufStart;                  /* First byte of buffer to write */
+  int iBufEnd;                    /* Last byte of buffer to write */
+  i64 iWriteOff;                  /* Offset of start of buffer in file */
+  sqlite3_file *pFd;              /* File handle to write to */
 };
 
 /*
-** A structure to store a single record. All in-memory records are connected
-** together into a linked list headed at VdbeSorter.pRecord using the 
-** SorterRecord.pNext pointer.
+** This object is the header on a single record while that record is being
+** held in memory and prior to being written out as part of a PMA.
+**
+** How the linked list is connected depends on how memory is being managed
+** by this module. If using a separate allocation for each in-memory record
+** (VdbeSorter.list.aMemory==0), then the list is always connected using the
+** SorterRecord.u.pNext pointers.
+**
+** Or, if using the single large allocation method (VdbeSorter.list.aMemory!=0),
+** then while records are being accumulated the list is linked using the
+** SorterRecord.u.iNext offset. This is because the aMemory[] array may
+** be sqlite3Realloc()ed while records are being accumulated. Once the VM
+** has finished passing records to the sorter, or when the in-memory buffer
+** is full, the list is sorted. As part of the sorting process, it is
+** converted to use the SorterRecord.u.pNext pointers. See function
+** vdbeSorterSort() for details.
 */
 struct SorterRecord {
-  void *pVal;
-  int nVal;
-  SorterRecord *pNext;
+  int nVal;                       /* Size of the record in bytes */
+  union {
+    SorterRecord *pNext;          /* Pointer to next record in list */
+    int iNext;                    /* Offset within aMemory of next record */
+  } u;
+  /* The data for the record immediately follows this header */
 };
 
-/* Minimum allowable value for the VdbeSorter.nWorking variable */
-#define SORTER_MIN_WORKING 10
+/* Return a pointer to the buffer containing the record data for SorterRecord
+** object p. Should be used as if:
+**
+**   void *SRVAL(SorterRecord *p) { return (void*)&p[1]; }
+*/
+#define SRVAL(p) ((void*)((SorterRecord*)(p) + 1))
 
-/* Maximum number of segments to merge in a single pass. */
+
+/* Maximum number of PMAs that a single MergeEngine can merge */
 #define SORTER_MAX_MERGE_COUNT 16
 
+static int vdbeIncrSwap(IncrMerger*);
+static void vdbeIncrFree(IncrMerger *);
+
 /*
-** Free all memory belonging to the VdbeSorterIter object passed as the second
+** Free all memory belonging to the PmaReader object passed as the
 ** argument. All structure fields are set to zero before returning.
 */
-static void vdbeSorterIterZero(sqlite3 *db, VdbeSorterIter *pIter){
-  sqlite3DbFree(db, pIter->aAlloc);
-  memset(pIter, 0, sizeof(VdbeSorterIter));
+static void vdbePmaReaderClear(PmaReader *pReadr){
+  sqlite3_free(pReadr->aAlloc);
+  sqlite3_free(pReadr->aBuffer);
+  if( pReadr->aMap ) sqlite3OsUnfetch(pReadr->pFd, 0, pReadr->aMap);
+  vdbeIncrFree(pReadr->pIncr);
+  memset(pReadr, 0, sizeof(PmaReader));
 }
 
 /*
-** Advance iterator pIter to the next key in its PMA. Return SQLITE_OK if
-** no error occurs, or an SQLite error code if one does.
+** Read the next nByte bytes of data from the PMA p.
+** If successful, set *ppOut to point to a buffer containing the data
+** and return SQLITE_OK. Otherwise, if an error occurs, return an SQLite
+** error code.
+**
+** The buffer returned in *ppOut is only valid until the
+** next call to this function.
 */
-static int vdbeSorterIterNext(
-  sqlite3 *db,                    /* Database handle (for sqlite3DbMalloc() ) */
-  VdbeSorterIter *pIter           /* Iterator to advance */
+static int vdbePmaReadBlob(
+  PmaReader *p,                   /* PmaReader from which to take the blob */
+  int nByte,                      /* Bytes of data to read */
+  u8 **ppOut                      /* OUT: Pointer to buffer containing data */
 ){
-  int rc;                         /* Return Code */
-  int nRead;                      /* Number of bytes read */
-  int nRec = 0;                   /* Size of record in bytes */
-  int iOff = 0;                   /* Size of serialized size varint in bytes */
+  int iBuf;                       /* Offset within buffer to read from */
+  int nAvail;                     /* Bytes of data available in buffer */
 
-  assert( pIter->iEof>=pIter->iReadOff );
-  if( pIter->iEof-pIter->iReadOff>5 ){
-    nRead = 5;
-  }else{
-    nRead = (int)(pIter->iEof - pIter->iReadOff);
-  }
-  if( nRead<=0 ){
-    /* This is an EOF condition */
-    vdbeSorterIterZero(db, pIter);
+  if( p->aMap ){
+    *ppOut = &p->aMap[p->iReadOff];
+    p->iReadOff += nByte;
     return SQLITE_OK;
   }
 
-  rc = sqlite3OsRead(pIter->pFile, pIter->aAlloc, nRead, pIter->iReadOff);
-  if( rc==SQLITE_OK ){
-    iOff = getVarint32(pIter->aAlloc, nRec);
-    if( (iOff+nRec)>nRead ){
-      int nRead2;                   /* Number of extra bytes to read */
-      if( (iOff+nRec)>pIter->nAlloc ){
-        int nNew = pIter->nAlloc*2;
-        while( (iOff+nRec)>nNew ) nNew = nNew*2;
-        pIter->aAlloc = sqlite3DbReallocOrFree(db, pIter->aAlloc, nNew);
-        if( !pIter->aAlloc ) return SQLITE_NOMEM;
-        pIter->nAlloc = nNew;
-      }
-  
-      nRead2 = iOff + nRec - nRead;
-      rc = sqlite3OsRead(
-          pIter->pFile, &pIter->aAlloc[nRead], nRead2, pIter->iReadOff+nRead
-      );
+  assert( p->aBuffer );
+
+  /* If there is no more data to be read from the buffer, read the next 
+  ** p->nBuffer bytes of data from the file into it. Or, if there are less
+  ** than p->nBuffer bytes remaining in the PMA, read all remaining data.  */
+  iBuf = p->iReadOff % p->nBuffer;
+  if( iBuf==0 ){
+    int nRead;                    /* Bytes to read from disk */
+    int rc;                       /* sqlite3OsRead() return code */
+
+    /* Determine how many bytes of data to read. */
+    if( (p->iEof - p->iReadOff) > (i64)p->nBuffer ){
+      nRead = p->nBuffer;
+    }else{
+      nRead = (int)(p->iEof - p->iReadOff);
     }
+    assert( nRead>0 );
+
+    /* Readr data from the file. Return early if an error occurs. */
+    rc = sqlite3OsRead(p->pFd, p->aBuffer, nRead, p->iReadOff);
+    assert( rc!=SQLITE_IOERR_SHORT_READ );
+    if( rc!=SQLITE_OK ) return rc;
   }
+  nAvail = p->nBuffer - iBuf; 
 
-  assert( rc!=SQLITE_OK || nRec>0 );
-  pIter->iReadOff += iOff+nRec;
-  pIter->nKey = nRec;
-  pIter->aKey = &pIter->aAlloc[iOff];
-  return rc;
+  if( nByte<=nAvail ){
+    /* The requested data is available in the in-memory buffer. In this
+    ** case there is no need to make a copy of the data, just return a 
+    ** pointer into the buffer to the caller.  */
+    *ppOut = &p->aBuffer[iBuf];
+    p->iReadOff += nByte;
+  }else{
+    /* The requested data is not all available in the in-memory buffer.
+    ** In this case, allocate space at p->aAlloc[] to copy the requested
+    ** range into. Then return a copy of pointer p->aAlloc to the caller.  */
+    int nRem;                     /* Bytes remaining to copy */
+
+    /* Extend the p->aAlloc[] allocation if required. */
+    if( p->nAlloc<nByte ){
+      u8 *aNew;
+      int nNew = MAX(128, p->nAlloc*2);
+      while( nByte>nNew ) nNew = nNew*2;
+      aNew = sqlite3Realloc(p->aAlloc, nNew);
+      if( !aNew ) return SQLITE_NOMEM_BKPT;
+      p->nAlloc = nNew;
+      p->aAlloc = aNew;
+    }
+
+    /* Copy as much data as is available in the buffer into the start of
+    ** p->aAlloc[].  */
+    memcpy(p->aAlloc, &p->aBuffer[iBuf], nAvail);
+    p->iReadOff += nAvail;
+    nRem = nByte - nAvail;
+
+    /* The following loop copies up to p->nBuffer bytes per iteration into
+    ** the p->aAlloc[] buffer.  */
+    while( nRem>0 ){
+      int rc;                     /* vdbePmaReadBlob() return code */
+      int nCopy;                  /* Number of bytes to copy */
+      u8 *aNext;                  /* Pointer to buffer to copy data from */
+
+      nCopy = nRem;
+      if( nRem>p->nBuffer ) nCopy = p->nBuffer;
+      rc = vdbePmaReadBlob(p, nCopy, &aNext);
+      if( rc!=SQLITE_OK ) return rc;
+      assert( aNext!=p->aAlloc );
+      memcpy(&p->aAlloc[nByte - nRem], aNext, nCopy);
+      nRem -= nCopy;
+    }
+
+    *ppOut = p->aAlloc;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Read a varint from the stream of data accessed by p. Set *pnOut to
+** the value read.
+*/
+static int vdbePmaReadVarint(PmaReader *p, u64 *pnOut){
+  int iBuf;
+
+  if( p->aMap ){
+    p->iReadOff += sqlite3GetVarint(&p->aMap[p->iReadOff], pnOut);
+  }else{
+    iBuf = p->iReadOff % p->nBuffer;
+    if( iBuf && (p->nBuffer-iBuf)>=9 ){
+      p->iReadOff += sqlite3GetVarint(&p->aBuffer[iBuf], pnOut);
+    }else{
+      u8 aVarint[16], *a;
+      int i = 0, rc;
+      do{
+        rc = vdbePmaReadBlob(p, 1, &a);
+        if( rc ) return rc;
+        aVarint[(i++)&0xf] = a[0];
+      }while( (a[0]&0x80)!=0 );
+      sqlite3GetVarint(aVarint, pnOut);
+    }
+  }
+
+  return SQLITE_OK;
 }
 
 /*
-** Write a single varint, value iVal, to file-descriptor pFile. Return
-** SQLITE_OK if successful, or an SQLite error code if some error occurs.
+** Attempt to memory map file pFile. If successful, set *pp to point to the
+** new mapping and return SQLITE_OK. If the mapping is not attempted 
+** (because the file is too large or the VFS layer is configured not to use
+** mmap), return SQLITE_OK and set *pp to NULL.
 **
-** The value of *piOffset when this function is called is used as the byte
-** offset in file pFile to write to. Before returning, *piOffset is 
-** incremented by the number of bytes written.
+** Or, if an error occurs, return an SQLite error code. The final value of
+** *pp is undefined in this case.
 */
-static int vdbeSorterWriteVarint(
-  sqlite3_file *pFile,            /* File to write to */
-  i64 iVal,                       /* Value to write as a varint */
-  i64 *piOffset                   /* IN/OUT: Write offset in file pFile */
+static int vdbeSorterMapFile(SortSubtask *pTask, SorterFile *pFile, u8 **pp){
+  int rc = SQLITE_OK;
+  if( pFile->iEof<=(i64)(pTask->pSorter->db->nMaxSorterMmap) ){
+    sqlite3_file *pFd = pFile->pFd;
+    if( pFd->pMethods->iVersion>=3 ){
+      rc = sqlite3OsFetch(pFd, 0, (int)pFile->iEof, (void**)pp);
+      testcase( rc!=SQLITE_OK );
+    }
+  }
+  return rc;
+}
+
+/*
+** Attach PmaReader pReadr to file pFile (if it is not already attached to
+** that file) and seek it to offset iOff within the file.  Return SQLITE_OK 
+** if successful, or an SQLite error code if an error occurs.
+*/
+static int vdbePmaReaderSeek(
+  SortSubtask *pTask,             /* Task context */
+  PmaReader *pReadr,              /* Reader whose cursor is to be moved */
+  SorterFile *pFile,              /* Sorter file to read from */
+  i64 iOff                        /* Offset in pFile */
 ){
-  u8 aVarint[9];                  /* Buffer large enough for a varint */
-  int nVarint;                    /* Number of used bytes in varint */
-  int rc;                         /* Result of write() call */
+  int rc = SQLITE_OK;
+
+  assert( pReadr->pIncr==0 || pReadr->pIncr->bEof==0 );
 
-  nVarint = sqlite3PutVarint(aVarint, iVal);
-  rc = sqlite3OsWrite(pFile, aVarint, nVarint, *piOffset);
-  *piOffset += nVarint;
+  if( sqlite3FaultSim(201) ) return SQLITE_IOERR_READ;
+  if( pReadr->aMap ){
+    sqlite3OsUnfetch(pReadr->pFd, 0, pReadr->aMap);
+    pReadr->aMap = 0;
+  }
+  pReadr->iReadOff = iOff;
+  pReadr->iEof = pFile->iEof;
+  pReadr->pFd = pFile->pFd;
+
+  rc = vdbeSorterMapFile(pTask, pFile, &pReadr->aMap);
+  if( rc==SQLITE_OK && pReadr->aMap==0 ){
+    int pgsz = pTask->pSorter->pgsz;
+    int iBuf = pReadr->iReadOff % pgsz;
+    if( pReadr->aBuffer==0 ){
+      pReadr->aBuffer = (u8*)sqlite3Malloc(pgsz);
+      if( pReadr->aBuffer==0 ) rc = SQLITE_NOMEM_BKPT;
+      pReadr->nBuffer = pgsz;
+    }
+    if( rc==SQLITE_OK && iBuf ){
+      int nRead = pgsz - iBuf;
+      if( (pReadr->iReadOff + nRead) > pReadr->iEof ){
+        nRead = (int)(pReadr->iEof - pReadr->iReadOff);
+      }
+      rc = sqlite3OsRead(
+          pReadr->pFd, &pReadr->aBuffer[iBuf], nRead, pReadr->iReadOff
+      );
+      testcase( rc!=SQLITE_OK );
+    }
+  }
 
   return rc;
 }
 
 /*
-** Read a single varint from file-descriptor pFile. Return SQLITE_OK if
-** successful, or an SQLite error code if some error occurs.
-**
-** The value of *piOffset when this function is called is used as the
-** byte offset in file pFile from whence to read the varint. If successful
-** (i.e. if no IO error occurs), then *piOffset is set to the offset of
-** the first byte past the end of the varint before returning. *piVal is
-** set to the integer value read. If an error occurs, the final values of
-** both *piOffset and *piVal are undefined.
+** Advance PmaReader pReadr to the next key in its PMA. Return SQLITE_OK if
+** no error occurs, or an SQLite error code if one does.
 */
-static int vdbeSorterReadVarint(
-  sqlite3_file *pFile,            /* File to read from */
-  i64 *piOffset,                  /* IN/OUT: Read offset in pFile */
-  i64 *piVal                      /* OUT: Value read from file */
-){
-  u8 aVarint[9];                  /* Buffer large enough for a varint */
-  i64 iOff = *piOffset;           /* Offset in file to read from */
-  int rc;                         /* Return code */
+static int vdbePmaReaderNext(PmaReader *pReadr){
+  int rc = SQLITE_OK;             /* Return Code */
+  u64 nRec = 0;                   /* Size of record in bytes */
+
+
+  if( pReadr->iReadOff>=pReadr->iEof ){
+    IncrMerger *pIncr = pReadr->pIncr;
+    int bEof = 1;
+    if( pIncr ){
+      rc = vdbeIncrSwap(pIncr);
+      if( rc==SQLITE_OK && pIncr->bEof==0 ){
+        rc = vdbePmaReaderSeek(
+            pIncr->pTask, pReadr, &pIncr->aFile[0], pIncr->iStartOff
+        );
+        bEof = 0;
+      }
+    }
+
+    if( bEof ){
+      /* This is an EOF condition */
+      vdbePmaReaderClear(pReadr);
+      testcase( rc!=SQLITE_OK );
+      return rc;
+    }
+  }
 
-  rc = sqlite3OsRead(pFile, aVarint, 9, iOff);
   if( rc==SQLITE_OK ){
-    *piOffset += getVarint(aVarint, (u64 *)piVal);
+    rc = vdbePmaReadVarint(pReadr, &nRec);
+  }
+  if( rc==SQLITE_OK ){
+    pReadr->nKey = (int)nRec;
+    rc = vdbePmaReadBlob(pReadr, (int)nRec, &pReadr->aKey);
+    testcase( rc!=SQLITE_OK );
   }
 
   return rc;
 }
 
 /*
-** Initialize iterator pIter to scan through the PMA stored in file pFile
+** Initialize PmaReader pReadr to scan through the PMA stored in file pFile
 ** starting at offset iStart and ending at offset iEof-1. This function 
-** leaves the iterator pointing to the first key in the PMA (or EOF if the 
+** leaves the PmaReader pointing to the first key in the PMA (or EOF if the 
 ** PMA is empty).
+**
+** If the pnByte parameter is NULL, then it is assumed that the file 
+** contains a single PMA, and that that PMA omits the initial length varint.
 */
-static int vdbeSorterIterInit(
-  sqlite3 *db,                    /* Database handle */
-  VdbeSorter *pSorter,            /* Sorter object */
+static int vdbePmaReaderInit(
+  SortSubtask *pTask,             /* Task context */
+  SorterFile *pFile,              /* Sorter file to read from */
   i64 iStart,                     /* Start offset in pFile */
-  VdbeSorterIter *pIter,          /* Iterator to populate */
+  PmaReader *pReadr,              /* PmaReader to populate */
   i64 *pnByte                     /* IN/OUT: Increment this value by PMA size */
 ){
   int rc;
 
-  assert( pSorter->iWriteOff>iStart );
-  assert( pIter->aAlloc==0 );
-  pIter->pFile = pSorter->pTemp1;
-  pIter->iReadOff = iStart;
-  pIter->nAlloc = 128;
-  pIter->aAlloc = (u8 *)sqlite3DbMallocRaw(db, pIter->nAlloc);
-  if( !pIter->aAlloc ){
-    rc = SQLITE_NOMEM;
-  }else{
-    i64 nByte;                         /* Total size of PMA in bytes */
-    rc = vdbeSorterReadVarint(pSorter->pTemp1, &pIter->iReadOff, &nByte);
+  assert( pFile->iEof>iStart );
+  assert( pReadr->aAlloc==0 && pReadr->nAlloc==0 );
+  assert( pReadr->aBuffer==0 );
+  assert( pReadr->aMap==0 );
+
+  rc = vdbePmaReaderSeek(pTask, pReadr, pFile, iStart);
+  if( rc==SQLITE_OK ){
+    u64 nByte = 0;                 /* Size of PMA in bytes */
+    rc = vdbePmaReadVarint(pReadr, &nByte);
+    pReadr->iEof = pReadr->iReadOff + nByte;
     *pnByte += nByte;
-    pIter->iEof = pIter->iReadOff + nByte;
   }
+
   if( rc==SQLITE_OK ){
-    rc = vdbeSorterIterNext(db, pIter);
+    rc = vdbePmaReaderNext(pReadr);
   }
   return rc;
 }
 
+/*
+** A version of vdbeSorterCompare() that assumes that it has already been
+** determined that the first field of key1 is equal to the first field of 
+** key2.
+*/
+static int vdbeSorterCompareTail(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  UnpackedRecord *r2 = pTask->pUnpacked;
+  if( *pbKey2Cached==0 ){
+    sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);
+    *pbKey2Cached = 1;
+  }
+  return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, r2, 1);
+}
 
 /*
 ** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, 
-** size nKey2 bytes).  Argument pKeyInfo supplies the collation functions
-** used by the comparison. If an error occurs, return an SQLite error code.
-** Otherwise, return SQLITE_OK and set *pRes to a negative, zero or positive
-** value, depending on whether key1 is smaller, equal to or larger than key2.
-**
-** If the bOmitRowid argument is non-zero, assume both keys end in a rowid
-** field. For the purposes of the comparison, ignore it. Also, if bOmitRowid
-** is true and key1 contains even a single NULL value, it is considered to
-** be less than key2. Even if key2 also contains NULL values.
-**
-** If pKey2 is passed a NULL pointer, then it is assumed that the pCsr->aSpace
-** has been allocated and contains an unpacked record that is used as key2.
-*/
-static void vdbeSorterCompare(
-  VdbeCursor *pCsr,               /* Cursor object (for pKeyInfo) */
-  int bOmitRowid,                 /* Ignore rowid field at end of keys */
-  void *pKey1, int nKey1,         /* Left side of comparison */
-  void *pKey2, int nKey2,         /* Right side of comparison */
-  int *pRes                       /* OUT: Result of comparison */
+** size nKey2 bytes). Use (pTask->pKeyInfo) for the collation sequences
+** used by the comparison. Return the result of the comparison.
+**
+** If IN/OUT parameter *pbKey2Cached is true when this function is called,
+** it is assumed that (pTask->pUnpacked) contains the unpacked version
+** of key2. If it is false, (pTask->pUnpacked) is populated with the unpacked
+** version of key2 and *pbKey2Cached set to true before returning.
+**
+** If an OOM error is encountered, (pTask->pUnpacked->error_rc) is set
+** to SQLITE_NOMEM.
+*/
+static int vdbeSorterCompare(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
 ){
-  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
-  VdbeSorter *pSorter = pCsr->pSorter;
-  UnpackedRecord *r2 = pSorter->pUnpacked;
-  int i;
+  UnpackedRecord *r2 = pTask->pUnpacked;
+  if( !*pbKey2Cached ){
+    sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);
+    *pbKey2Cached = 1;
+  }
+  return sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
+}
 
-  if( pKey2 ){
-    sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, r2);
+/*
+** A specially optimized version of vdbeSorterCompare() that assumes that
+** the first field of each key is a TEXT value and that the collation
+** sequence to compare them with is BINARY.
+*/
+static int vdbeSorterCompareText(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  const u8 * const p1 = (const u8 * const)pKey1;
+  const u8 * const p2 = (const u8 * const)pKey2;
+  const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */
+  const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */
+
+  int n1;
+  int n2;
+  int res;
+
+  getVarint32(&p1[1], n1); n1 = (n1 - 13) / 2;
+  getVarint32(&p2[1], n2); n2 = (n2 - 13) / 2;
+  res = memcmp(v1, v2, MIN(n1, n2));
+  if( res==0 ){
+    res = n1 - n2;
   }
 
-  if( bOmitRowid ){
-    r2->nField = pKeyInfo->nField;
-    assert( r2->nField>0 );
-    for(i=0; i<r2->nField; i++){
-      if( r2->aMem[i].flags & MEM_Null ){
-        *pRes = -1;
-        return;
-      }
+  if( res==0 ){
+    if( pTask->pSorter->pKeyInfo->nField>1 ){
+      res = vdbeSorterCompareTail(
+          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
+      );
+    }
+  }else{
+    if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
+      res = res * -1;
     }
-    r2->flags |= UNPACKED_PREFIX_MATCH;
   }
 
-  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
+  return res;
 }
 
 /*
-** This function is called to compare two iterator keys when merging 
-** multiple b-tree segments. Parameter iOut is the index of the aTree[] 
-** value to recalculate.
+** A specially optimized version of vdbeSorterCompare() that assumes that
+** the first field of each key is an INTEGER value.
 */
-static int vdbeSorterDoCompare(VdbeCursor *pCsr, int iOut){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  int i1;
-  int i2;
-  int iRes;
-  VdbeSorterIter *p1;
-  VdbeSorterIter *p2;
+static int vdbeSorterCompareInt(
+  SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */
+  int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */
+  const void *pKey1, int nKey1,   /* Left side of comparison */
+  const void *pKey2, int nKey2    /* Right side of comparison */
+){
+  const u8 * const p1 = (const u8 * const)pKey1;
+  const u8 * const p2 = (const u8 * const)pKey2;
+  const int s1 = p1[1];                 /* Left hand serial type */
+  const int s2 = p2[1];                 /* Right hand serial type */
+  const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */
+  const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */
+  int res;                              /* Return value */
 
-  assert( iOut<pSorter->nTree && iOut>0 );
+  assert( (s1>0 && s1<7) || s1==8 || s1==9 );
+  assert( (s2>0 && s2<7) || s2==8 || s2==9 );
 
-  if( iOut>=(pSorter->nTree/2) ){
-    i1 = (iOut - pSorter->nTree/2) * 2;
-    i2 = i1 + 1;
+  if( s1>7 && s2>7 ){
+    res = s1 - s2;
   }else{
-    i1 = pSorter->aTree[iOut*2];
-    i2 = pSorter->aTree[iOut*2+1];
-  }
+    if( s1==s2 ){
+      if( (*v1 ^ *v2) & 0x80 ){
+        /* The two values have different signs */
+        res = (*v1 & 0x80) ? -1 : +1;
+      }else{
+        /* The two values have the same sign. Compare using memcmp(). */
+        static const u8 aLen[] = {0, 1, 2, 3, 4, 6, 8 };
+        int i;
+        res = 0;
+        for(i=0; i<aLen[s1]; i++){
+          if( (res = v1[i] - v2[i]) ) break;
+        }
+      }
+    }else{
+      if( s2>7 ){
+        res = +1;
+      }else if( s1>7 ){
+        res = -1;
+      }else{
+        res = s1 - s2;
+      }
+      assert( res!=0 );
 
-  p1 = &pSorter->aIter[i1];
-  p2 = &pSorter->aIter[i2];
+      if( res>0 ){
+        if( *v1 & 0x80 ) res = -1;
+      }else{
+        if( *v2 & 0x80 ) res = +1;
+      }
+    }
+  }
 
-  if( p1->pFile==0 ){
-    iRes = i2;
-  }else if( p2->pFile==0 ){
-    iRes = i1;
-  }else{
-    int res;
-    assert( pCsr->pSorter->pUnpacked!=0 );  /* allocated in vdbeSorterMerge() */
-    vdbeSorterCompare(
-        pCsr, 0, p1->aKey, p1->nKey, p2->aKey, p2->nKey, &res
-    );
-    if( res<=0 ){
-      iRes = i1;
-    }else{
-      iRes = i2;
+  if( res==0 ){
+    if( pTask->pSorter->pKeyInfo->nField>1 ){
+      res = vdbeSorterCompareTail(
+          pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2
+      );
     }
+  }else if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){
+    res = res * -1;
   }
 
-  pSorter->aTree[iOut] = iRes;
-  return SQLITE_OK;
+  return res;
 }
 
 /*
 ** Initialize the temporary index cursor just opened as a sorter cursor.
+**
+** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nField)
+** to determine the number of fields that should be compared from the
+** records being sorted. However, if the value passed as argument nField
+** is non-zero and the sorter is able to guarantee a stable sort, nField
+** is used instead. This is used when sorting records for a CREATE INDEX
+** statement. In this case, keys are always delivered to the sorter in
+** order of the primary key, which happens to be make up the final part 
+** of the records being sorted. So if the sort is stable, there is never
+** any reason to compare PK fields and they can be ignored for a small
+** performance boost.
+**
+** The sorter can guarantee a stable sort when running in single-threaded
+** mode, but not in multi-threaded mode.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
+SQLITE_PRIVATE int sqlite3VdbeSorterInit(
+  sqlite3 *db,                    /* Database connection (for malloc()) */
+  int nField,                     /* Number of key fields in each record */
+  VdbeCursor *pCsr                /* Cursor that holds the new sorter */
+){
   int pgsz;                       /* Page size of main database */
-  int mxCache;                    /* Cache size */
+  int i;                          /* Used to iterate through aTask[] */
   VdbeSorter *pSorter;            /* The new sorter */
-  char *d;                        /* Dummy */
+  KeyInfo *pKeyInfo;              /* Copy of pCsr->pKeyInfo with db==0 */
+  int szKeyInfo;                  /* Size of pCsr->pKeyInfo in bytes */
+  int sz;                         /* Size of pSorter in bytes */
+  int rc = SQLITE_OK;
+#if SQLITE_MAX_WORKER_THREADS==0
+# define nWorker 0
+#else
+  int nWorker;
+#endif
+
+  /* Initialize the upper limit on the number of worker threads */
+#if SQLITE_MAX_WORKER_THREADS>0
+  if( sqlite3TempInMemory(db) || sqlite3GlobalConfig.bCoreMutex==0 ){
+    nWorker = 0;
+  }else{
+    nWorker = db->aLimit[SQLITE_LIMIT_WORKER_THREADS];
+  }
+#endif
+
+  /* Do not allow the total number of threads (main thread + all workers)
+  ** to exceed the maximum merge count */
+#if SQLITE_MAX_WORKER_THREADS>=SORTER_MAX_MERGE_COUNT
+  if( nWorker>=SORTER_MAX_MERGE_COUNT ){
+    nWorker = SORTER_MAX_MERGE_COUNT-1;
+  }
+#endif
 
   assert( pCsr->pKeyInfo && pCsr->pBt==0 );
-  pCsr->pSorter = pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  szKeyInfo = sizeof(KeyInfo) + (pCsr->pKeyInfo->nField-1)*sizeof(CollSeq*);
+  sz = sizeof(VdbeSorter) + nWorker * sizeof(SortSubtask);
+
+  pSorter = (VdbeSorter*)sqlite3DbMallocZero(db, sz + szKeyInfo);
+  pCsr->uc.pSorter = pSorter;
   if( pSorter==0 ){
-    return SQLITE_NOMEM;
-  }
-  
-  pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pCsr->pKeyInfo, 0, 0, &d);
-  if( pSorter->pUnpacked==0 ) return SQLITE_NOMEM;
-  assert( pSorter->pUnpacked==(UnpackedRecord *)d );
+    rc = SQLITE_NOMEM_BKPT;
+  }else{
+    pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);
+    memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);
+    pKeyInfo->db = 0;
+    if( nField && nWorker==0 ){
+      pKeyInfo->nXField += (pKeyInfo->nField - nField);
+      pKeyInfo->nField = nField;
+    }
+    pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
+    pSorter->nTask = nWorker + 1;
+    pSorter->iPrev = (u8)(nWorker - 1);
+    pSorter->bUseThreads = (pSorter->nTask>1);
+    pSorter->db = db;
+    for(i=0; i<pSorter->nTask; i++){
+      SortSubtask *pTask = &pSorter->aTask[i];
+      pTask->pSorter = pSorter;
+    }
+
+    if( !sqlite3TempInMemory(db) ){
+      i64 mxCache;                /* Cache size in bytes*/
+      u32 szPma = sqlite3GlobalConfig.szPma;
+      pSorter->mnPmaSize = szPma * pgsz;
+
+      mxCache = db->aDb[0].pSchema->cache_size;
+      if( mxCache<0 ){
+        /* A negative cache-size value C indicates that the cache is abs(C)
+        ** KiB in size.  */
+        mxCache = mxCache * -1024;
+      }else{
+        mxCache = mxCache * pgsz;
+      }
+      mxCache = MIN(mxCache, SQLITE_MAX_PMASZ);
+      pSorter->mxPmaSize = MAX(pSorter->mnPmaSize, (int)mxCache);
 
-  if( !sqlite3TempInMemory(db) ){
-    pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
-    pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
-    mxCache = db->aDb[0].pSchema->cache_size;
-    if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
-    pSorter->mxPmaSize = mxCache * pgsz;
+      /* EVIDENCE-OF: R-26747-61719 When the application provides any amount of
+      ** scratch memory using SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary
+      ** large heap allocations.
+      */
+      if( sqlite3GlobalConfig.pScratch==0 ){
+        assert( pSorter->iMemory==0 );
+        pSorter->nMemory = pgsz;
+        pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);
+        if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM_BKPT;
+      }
+    }
+
+    if( (pKeyInfo->nField+pKeyInfo->nXField)<13 
+     && (pKeyInfo->aColl[0]==0 || pKeyInfo->aColl[0]==db->pDfltColl)
+    ){
+      pSorter->typeMask = SORTER_TYPE_INTEGER | SORTER_TYPE_TEXT;
+    }
   }
 
-  return SQLITE_OK;
+  return rc;
 }
+#undef nWorker   /* Defined at the top of this function */
 
 /*
 ** Free the list of sorted records starting at pRecord.
@@ -70584,104 +85645,406 @@ static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
   SorterRecord *p;
   SorterRecord *pNext;
   for(p=pRecord; p; p=pNext){
-    pNext = p->pNext;
+    pNext = p->u.pNext;
     sqlite3DbFree(db, p);
   }
 }
 
 /*
+** Free all resources owned by the object indicated by argument pTask. All 
+** fields of *pTask are zeroed before returning.
+*/
+static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){
+  sqlite3DbFree(db, pTask->pUnpacked);
+#if SQLITE_MAX_WORKER_THREADS>0
+  /* pTask->list.aMemory can only be non-zero if it was handed memory
+  ** from the main thread.  That only occurs SQLITE_MAX_WORKER_THREADS>0 */
+  if( pTask->list.aMemory ){
+    sqlite3_free(pTask->list.aMemory);
+  }else
+#endif
+  {
+    assert( pTask->list.aMemory==0 );
+    vdbeSorterRecordFree(0, pTask->list.pList);
+  }
+  if( pTask->file.pFd ){
+    sqlite3OsCloseFree(pTask->file.pFd);
+  }
+  if( pTask->file2.pFd ){
+    sqlite3OsCloseFree(pTask->file2.pFd);
+  }
+  memset(pTask, 0, sizeof(SortSubtask));
+}
+
+#ifdef SQLITE_DEBUG_SORTER_THREADS
+static void vdbeSorterWorkDebug(SortSubtask *pTask, const char *zEvent){
+  i64 t;
+  int iTask = (pTask - pTask->pSorter->aTask);
+  sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);
+  fprintf(stderr, "%lld:%d %s\n", t, iTask, zEvent);
+}
+static void vdbeSorterRewindDebug(const char *zEvent){
+  i64 t;
+  sqlite3OsCurrentTimeInt64(sqlite3_vfs_find(0), &t);
+  fprintf(stderr, "%lld:X %s\n", t, zEvent);
+}
+static void vdbeSorterPopulateDebug(
+  SortSubtask *pTask,
+  const char *zEvent
+){
+  i64 t;
+  int iTask = (pTask - pTask->pSorter->aTask);
+  sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);
+  fprintf(stderr, "%lld:bg%d %s\n", t, iTask, zEvent);
+}
+static void vdbeSorterBlockDebug(
+  SortSubtask *pTask,
+  int bBlocked,
+  const char *zEvent
+){
+  if( bBlocked ){
+    i64 t;
+    sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);
+    fprintf(stderr, "%lld:main %s\n", t, zEvent);
+  }
+}
+#else
+# define vdbeSorterWorkDebug(x,y)
+# define vdbeSorterRewindDebug(y)
+# define vdbeSorterPopulateDebug(x,y)
+# define vdbeSorterBlockDebug(x,y,z)
+#endif
+
+#if SQLITE_MAX_WORKER_THREADS>0
+/*
+** Join thread pTask->thread.
+*/
+static int vdbeSorterJoinThread(SortSubtask *pTask){
+  int rc = SQLITE_OK;
+  if( pTask->pThread ){
+#ifdef SQLITE_DEBUG_SORTER_THREADS
+    int bDone = pTask->bDone;
+#endif
+    void *pRet = SQLITE_INT_TO_PTR(SQLITE_ERROR);
+    vdbeSorterBlockDebug(pTask, !bDone, "enter");
+    (void)sqlite3ThreadJoin(pTask->pThread, &pRet);
+    vdbeSorterBlockDebug(pTask, !bDone, "exit");
+    rc = SQLITE_PTR_TO_INT(pRet);
+    assert( pTask->bDone==1 );
+    pTask->bDone = 0;
+    pTask->pThread = 0;
+  }
+  return rc;
+}
+
+/*
+** Launch a background thread to run xTask(pIn).
+*/
+static int vdbeSorterCreateThread(
+  SortSubtask *pTask,             /* Thread will use this task object */
+  void *(*xTask)(void*),          /* Routine to run in a separate thread */
+  void *pIn                       /* Argument passed into xTask() */
+){
+  assert( pTask->pThread==0 && pTask->bDone==0 );
+  return sqlite3ThreadCreate(&pTask->pThread, xTask, pIn);
+}
+
+/*
+** Join all outstanding threads launched by SorterWrite() to create 
+** level-0 PMAs.
+*/
+static int vdbeSorterJoinAll(VdbeSorter *pSorter, int rcin){
+  int rc = rcin;
+  int i;
+
+  /* This function is always called by the main user thread.
+  **
+  ** If this function is being called after SorterRewind() has been called, 
+  ** it is possible that thread pSorter->aTask[pSorter->nTask-1].pThread
+  ** is currently attempt to join one of the other threads. To avoid a race
+  ** condition where this thread also attempts to join the same object, join 
+  ** thread pSorter->aTask[pSorter->nTask-1].pThread first. */
+  for(i=pSorter->nTask-1; i>=0; i--){
+    SortSubtask *pTask = &pSorter->aTask[i];
+    int rc2 = vdbeSorterJoinThread(pTask);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+  return rc;
+}
+#else
+# define vdbeSorterJoinAll(x,rcin) (rcin)
+# define vdbeSorterJoinThread(pTask) SQLITE_OK
+#endif
+
+/*
+** Allocate a new MergeEngine object capable of handling up to
+** nReader PmaReader inputs.
+**
+** nReader is automatically rounded up to the next power of two.
+** nReader may not exceed SORTER_MAX_MERGE_COUNT even after rounding up.
+*/
+static MergeEngine *vdbeMergeEngineNew(int nReader){
+  int N = 2;                      /* Smallest power of two >= nReader */
+  int nByte;                      /* Total bytes of space to allocate */
+  MergeEngine *pNew;              /* Pointer to allocated object to return */
+
+  assert( nReader<=SORTER_MAX_MERGE_COUNT );
+
+  while( N<nReader ) N += N;
+  nByte = sizeof(MergeEngine) + N * (sizeof(int) + sizeof(PmaReader));
+
+  pNew = sqlite3FaultSim(100) ? 0 : (MergeEngine*)sqlite3MallocZero(nByte);
+  if( pNew ){
+    pNew->nTree = N;
+    pNew->pTask = 0;
+    pNew->aReadr = (PmaReader*)&pNew[1];
+    pNew->aTree = (int*)&pNew->aReadr[N];
+  }
+  return pNew;
+}
+
+/*
+** Free the MergeEngine object passed as the only argument.
+*/
+static void vdbeMergeEngineFree(MergeEngine *pMerger){
+  int i;
+  if( pMerger ){
+    for(i=0; i<pMerger->nTree; i++){
+      vdbePmaReaderClear(&pMerger->aReadr[i]);
+    }
+  }
+  sqlite3_free(pMerger);
+}
+
+/*
+** Free all resources associated with the IncrMerger object indicated by
+** the first argument.
+*/
+static void vdbeIncrFree(IncrMerger *pIncr){
+  if( pIncr ){
+#if SQLITE_MAX_WORKER_THREADS>0
+    if( pIncr->bUseThread ){
+      vdbeSorterJoinThread(pIncr->pTask);
+      if( pIncr->aFile[0].pFd ) sqlite3OsCloseFree(pIncr->aFile[0].pFd);
+      if( pIncr->aFile[1].pFd ) sqlite3OsCloseFree(pIncr->aFile[1].pFd);
+    }
+#endif
+    vdbeMergeEngineFree(pIncr->pMerger);
+    sqlite3_free(pIncr);
+  }
+}
+
+/*
+** Reset a sorting cursor back to its original empty state.
+*/
+SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
+  int i;
+  (void)vdbeSorterJoinAll(pSorter, SQLITE_OK);
+  assert( pSorter->bUseThreads || pSorter->pReader==0 );
+#if SQLITE_MAX_WORKER_THREADS>0
+  if( pSorter->pReader ){
+    vdbePmaReaderClear(pSorter->pReader);
+    sqlite3DbFree(db, pSorter->pReader);
+    pSorter->pReader = 0;
+  }
+#endif
+  vdbeMergeEngineFree(pSorter->pMerger);
+  pSorter->pMerger = 0;
+  for(i=0; i<pSorter->nTask; i++){
+    SortSubtask *pTask = &pSorter->aTask[i];
+    vdbeSortSubtaskCleanup(db, pTask);
+    pTask->pSorter = pSorter;
+  }
+  if( pSorter->list.aMemory==0 ){
+    vdbeSorterRecordFree(0, pSorter->list.pList);
+  }
+  pSorter->list.pList = 0;
+  pSorter->list.szPMA = 0;
+  pSorter->bUsePMA = 0;
+  pSorter->iMemory = 0;
+  pSorter->mxKeysize = 0;
+  sqlite3DbFree(db, pSorter->pUnpacked);
+  pSorter->pUnpacked = 0;
+}
+
+/*
 ** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
 */
 SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
   if( pSorter ){
-    if( pSorter->aIter ){
-      int i;
-      for(i=0; i<pSorter->nTree; i++){
-        vdbeSorterIterZero(db, &pSorter->aIter[i]);
-      }
-      sqlite3DbFree(db, pSorter->aIter);
-    }
-    if( pSorter->pTemp1 ){
-      sqlite3OsCloseFree(pSorter->pTemp1);
-    }
-    vdbeSorterRecordFree(db, pSorter->pRecord);
-    sqlite3DbFree(db, pSorter->pUnpacked);
+    sqlite3VdbeSorterReset(db, pSorter);
+    sqlite3_free(pSorter->list.aMemory);
     sqlite3DbFree(db, pSorter);
-    pCsr->pSorter = 0;
+    pCsr->uc.pSorter = 0;
   }
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/*
+** The first argument is a file-handle open on a temporary file. The file
+** is guaranteed to be nByte bytes or smaller in size. This function
+** attempts to extend the file to nByte bytes in size and to ensure that
+** the VFS has memory mapped it.
+**
+** Whether or not the file does end up memory mapped of course depends on
+** the specific VFS implementation.
+*/
+static void vdbeSorterExtendFile(sqlite3 *db, sqlite3_file *pFd, i64 nByte){
+  if( nByte<=(i64)(db->nMaxSorterMmap) && pFd->pMethods->iVersion>=3 ){
+    void *p = 0;
+    int chunksize = 4*1024;
+    sqlite3OsFileControlHint(pFd, SQLITE_FCNTL_CHUNK_SIZE, &chunksize);
+    sqlite3OsFileControlHint(pFd, SQLITE_FCNTL_SIZE_HINT, &nByte);
+    sqlite3OsFetch(pFd, 0, (int)nByte, &p);
+    sqlite3OsUnfetch(pFd, 0, p);
+  }
+}
+#else
+# define vdbeSorterExtendFile(x,y,z)
+#endif
+
 /*
 ** Allocate space for a file-handle and open a temporary file. If successful,
-** set *ppFile to point to the malloc'd file-handle and return SQLITE_OK.
-** Otherwise, set *ppFile to 0 and return an SQLite error code.
+** set *ppFd to point to the malloc'd file-handle and return SQLITE_OK.
+** Otherwise, set *ppFd to 0 and return an SQLite error code.
 */
-static int vdbeSorterOpenTempFile(sqlite3 *db, sqlite3_file **ppFile){
-  int dummy;
-  return sqlite3OsOpenMalloc(db->pVfs, 0, ppFile,
+static int vdbeSorterOpenTempFile(
+  sqlite3 *db,                    /* Database handle doing sort */
+  i64 nExtend,                    /* Attempt to extend file to this size */
+  sqlite3_file **ppFd
+){
+  int rc;
+  if( sqlite3FaultSim(202) ) return SQLITE_IOERR_ACCESS;
+  rc = sqlite3OsOpenMalloc(db->pVfs, 0, ppFd,
       SQLITE_OPEN_TEMP_JOURNAL |
       SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
-      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &dummy
+      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &rc
   );
+  if( rc==SQLITE_OK ){
+    i64 max = SQLITE_MAX_MMAP_SIZE;
+    sqlite3OsFileControlHint(*ppFd, SQLITE_FCNTL_MMAP_SIZE, (void*)&max);
+    if( nExtend>0 ){
+      vdbeSorterExtendFile(db, *ppFd, nExtend);
+    }
+  }
+  return rc;
 }
 
 /*
+** If it has not already been allocated, allocate the UnpackedRecord 
+** structure at pTask->pUnpacked. Return SQLITE_OK if successful (or 
+** if no allocation was required), or SQLITE_NOMEM otherwise.
+*/
+static int vdbeSortAllocUnpacked(SortSubtask *pTask){
+  if( pTask->pUnpacked==0 ){
+    char *pFree;
+    pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord(
+        pTask->pSorter->pKeyInfo, 0, 0, &pFree
+    );
+    assert( pTask->pUnpacked==(UnpackedRecord*)pFree );
+    if( pFree==0 ) return SQLITE_NOMEM_BKPT;
+    pTask->pUnpacked->nField = pTask->pSorter->pKeyInfo->nField;
+    pTask->pUnpacked->errCode = 0;
+  }
+  return SQLITE_OK;
+}
+
+
+/*
 ** Merge the two sorted lists p1 and p2 into a single list.
-** Set *ppOut to the head of the new list.
 */
-static void vdbeSorterMerge(
-  VdbeCursor *pCsr,               /* For pKeyInfo */
+static SorterRecord *vdbeSorterMerge(
+  SortSubtask *pTask,             /* Calling thread context */
   SorterRecord *p1,               /* First list to merge */
-  SorterRecord *p2,               /* Second list to merge */
-  SorterRecord **ppOut            /* OUT: Head of merged list */
+  SorterRecord *p2                /* Second list to merge */
 ){
   SorterRecord *pFinal = 0;
   SorterRecord **pp = &pFinal;
-  void *pVal2 = p2 ? p2->pVal : 0;
+  int bCached = 0;
 
-  while( p1 && p2 ){
+  assert( p1!=0 && p2!=0 );
+  for(;;){
     int res;
-    vdbeSorterCompare(pCsr, 0, p1->pVal, p1->nVal, pVal2, p2->nVal, &res);
+    res = pTask->xCompare(
+        pTask, &bCached, SRVAL(p1), p1->nVal, SRVAL(p2), p2->nVal
+    );
+
     if( res<=0 ){
       *pp = p1;
-      pp = &p1->pNext;
-      p1 = p1->pNext;
-      pVal2 = 0;
+      pp = &p1->u.pNext;
+      p1 = p1->u.pNext;
+      if( p1==0 ){
+        *pp = p2;
+        break;
+      }
     }else{
       *pp = p2;
-       pp = &p2->pNext;
-      p2 = p2->pNext;
-      if( p2==0 ) break;
-      pVal2 = p2->pVal;
+      pp = &p2->u.pNext;
+      p2 = p2->u.pNext;
+      bCached = 0;
+      if( p2==0 ){
+        *pp = p1;
+        break;
+      }
     }
   }
-  *pp = p1 ? p1 : p2;
-  *ppOut = pFinal;
+  return pFinal;
 }
 
 /*
-** Sort the linked list of records headed at pCsr->pRecord. Return SQLITE_OK
-** if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if an error
-** occurs.
+** Return the SorterCompare function to compare values collected by the
+** sorter object passed as the only argument.
+*/
+static SorterCompare vdbeSorterGetCompare(VdbeSorter *p){
+  if( p->typeMask==SORTER_TYPE_INTEGER ){
+    return vdbeSorterCompareInt;
+  }else if( p->typeMask==SORTER_TYPE_TEXT ){
+    return vdbeSorterCompareText; 
+  }
+  return vdbeSorterCompare;
+}
+
+/*
+** Sort the linked list of records headed at pTask->pList. Return 
+** SQLITE_OK if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if 
+** an error occurs.
 */
-static int vdbeSorterSort(VdbeCursor *pCsr){
+static int vdbeSorterSort(SortSubtask *pTask, SorterList *pList){
   int i;
   SorterRecord **aSlot;
   SorterRecord *p;
-  VdbeSorter *pSorter = pCsr->pSorter;
+  int rc;
+
+  rc = vdbeSortAllocUnpacked(pTask);
+  if( rc!=SQLITE_OK ) return rc;
+
+  p = pList->pList;
+  pTask->xCompare = vdbeSorterGetCompare(pTask->pSorter);
 
   aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));
   if( !aSlot ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
-  p = pSorter->pRecord;
   while( p ){
-    SorterRecord *pNext = p->pNext;
-    p->pNext = 0;
+    SorterRecord *pNext;
+    if( pList->aMemory ){
+      if( (u8*)p==pList->aMemory ){
+        pNext = 0;
+      }else{
+        assert( p->u.iNext<sqlite3MallocSize(pList->aMemory) );
+        pNext = (SorterRecord*)&pList->aMemory[p->u.iNext];
+      }
+    }else{
+      pNext = p->u.pNext;
+    }
+
+    p->u.pNext = 0;
     for(i=0; aSlot[i]; i++){
-      vdbeSorterMerge(pCsr, p, aSlot[i], &p);
+      p = vdbeSorterMerge(pTask, p, aSlot[i]);
       aSlot[i] = 0;
     }
     aSlot[i] = p;
@@ -70690,18 +86053,106 @@ static int vdbeSorterSort(VdbeCursor *pCsr){
 
   p = 0;
   for(i=0; i<64; i++){
-    vdbeSorterMerge(pCsr, p, aSlot[i], &p);
+    if( aSlot[i]==0 ) continue;
+    p = p ? vdbeSorterMerge(pTask, p, aSlot[i]) : aSlot[i];
   }
-  pSorter->pRecord = p;
+  pList->pList = p;
 
   sqlite3_free(aSlot);
-  return SQLITE_OK;
+  assert( pTask->pUnpacked->errCode==SQLITE_OK 
+       || pTask->pUnpacked->errCode==SQLITE_NOMEM 
+  );
+  return pTask->pUnpacked->errCode;
 }
 
+/*
+** Initialize a PMA-writer object.
+*/
+static void vdbePmaWriterInit(
+  sqlite3_file *pFd,              /* File handle to write to */
+  PmaWriter *p,                   /* Object to populate */
+  int nBuf,                       /* Buffer size */
+  i64 iStart                      /* Offset of pFd to begin writing at */
+){
+  memset(p, 0, sizeof(PmaWriter));
+  p->aBuffer = (u8*)sqlite3Malloc(nBuf);
+  if( !p->aBuffer ){
+    p->eFWErr = SQLITE_NOMEM_BKPT;
+  }else{
+    p->iBufEnd = p->iBufStart = (iStart % nBuf);
+    p->iWriteOff = iStart - p->iBufStart;
+    p->nBuffer = nBuf;
+    p->pFd = pFd;
+  }
+}
 
 /*
-** Write the current contents of the in-memory linked-list to a PMA. Return
-** SQLITE_OK if successful, or an SQLite error code otherwise.
+** Write nData bytes of data to the PMA. Return SQLITE_OK
+** if successful, or an SQLite error code if an error occurs.
+*/
+static void vdbePmaWriteBlob(PmaWriter *p, u8 *pData, int nData){
+  int nRem = nData;
+  while( nRem>0 && p->eFWErr==0 ){
+    int nCopy = nRem;
+    if( nCopy>(p->nBuffer - p->iBufEnd) ){
+      nCopy = p->nBuffer - p->iBufEnd;
+    }
+
+    memcpy(&p->aBuffer[p->iBufEnd], &pData[nData-nRem], nCopy);
+    p->iBufEnd += nCopy;
+    if( p->iBufEnd==p->nBuffer ){
+      p->eFWErr = sqlite3OsWrite(p->pFd, 
+          &p->aBuffer[p->iBufStart], p->iBufEnd - p->iBufStart, 
+          p->iWriteOff + p->iBufStart
+      );
+      p->iBufStart = p->iBufEnd = 0;
+      p->iWriteOff += p->nBuffer;
+    }
+    assert( p->iBufEnd<p->nBuffer );
+
+    nRem -= nCopy;
+  }
+}
+
+/*
+** Flush any buffered data to disk and clean up the PMA-writer object.
+** The results of using the PMA-writer after this call are undefined.
+** Return SQLITE_OK if flushing the buffered data succeeds or is not 
+** required. Otherwise, return an SQLite error code.
+**
+** Before returning, set *piEof to the offset immediately following the
+** last byte written to the file.
+*/
+static int vdbePmaWriterFinish(PmaWriter *p, i64 *piEof){
+  int rc;
+  if( p->eFWErr==0 && ALWAYS(p->aBuffer) && p->iBufEnd>p->iBufStart ){
+    p->eFWErr = sqlite3OsWrite(p->pFd, 
+        &p->aBuffer[p->iBufStart], p->iBufEnd - p->iBufStart, 
+        p->iWriteOff + p->iBufStart
+    );
+  }
+  *piEof = (p->iWriteOff + p->iBufEnd);
+  sqlite3_free(p->aBuffer);
+  rc = p->eFWErr;
+  memset(p, 0, sizeof(PmaWriter));
+  return rc;
+}
+
+/*
+** Write value iVal encoded as a varint to the PMA. Return 
+** SQLITE_OK if successful, or an SQLite error code if an error occurs.
+*/
+static void vdbePmaWriteVarint(PmaWriter *p, u64 iVal){
+  int nByte; 
+  u8 aByte[10];
+  nByte = sqlite3PutVarint(aByte, iVal);
+  vdbePmaWriteBlob(p, aByte, nByte);
+}
+
+/*
+** Write the current contents of in-memory linked-list pList to a level-0
+** PMA in the temp file belonging to sub-task pTask. Return SQLITE_OK if 
+** successful, or an SQLite error code otherwise.
 **
 ** The format of a PMA is:
 **
@@ -70712,92 +86163,256 @@ static int vdbeSorterSort(VdbeCursor *pCsr){
 **       Each record consists of a varint followed by a blob of data (the 
 **       key). The varint is the number of bytes in the blob of data.
 */
-static int vdbeSorterListToPMA(sqlite3 *db, VdbeCursor *pCsr){
+static int vdbeSorterListToPMA(SortSubtask *pTask, SorterList *pList){
+  sqlite3 *db = pTask->pSorter->db;
   int rc = SQLITE_OK;             /* Return code */
-  VdbeSorter *pSorter = pCsr->pSorter;
+  PmaWriter writer;               /* Object used to write to the file */
 
-  if( pSorter->nInMemory==0 ){
-    assert( pSorter->pRecord==0 );
-    return rc;
-  }
+#ifdef SQLITE_DEBUG
+  /* Set iSz to the expected size of file pTask->file after writing the PMA. 
+  ** This is used by an assert() statement at the end of this function.  */
+  i64 iSz = pList->szPMA + sqlite3VarintLen(pList->szPMA) + pTask->file.iEof;
+#endif
 
-  rc = vdbeSorterSort(pCsr);
+  vdbeSorterWorkDebug(pTask, "enter");
+  memset(&writer, 0, sizeof(PmaWriter));
+  assert( pList->szPMA>0 );
 
   /* If the first temporary PMA file has not been opened, open it now. */
-  if( rc==SQLITE_OK && pSorter->pTemp1==0 ){
-    rc = vdbeSorterOpenTempFile(db, &pSorter->pTemp1);
-    assert( rc!=SQLITE_OK || pSorter->pTemp1 );
-    assert( pSorter->iWriteOff==0 );
-    assert( pSorter->nPMA==0 );
+  if( pTask->file.pFd==0 ){
+    rc = vdbeSorterOpenTempFile(db, 0, &pTask->file.pFd);
+    assert( rc!=SQLITE_OK || pTask->file.pFd );
+    assert( pTask->file.iEof==0 );
+    assert( pTask->nPMA==0 );
+  }
+
+  /* Try to get the file to memory map */
+  if( rc==SQLITE_OK ){
+    vdbeSorterExtendFile(db, pTask->file.pFd, pTask->file.iEof+pList->szPMA+9);
+  }
+
+  /* Sort the list */
+  if( rc==SQLITE_OK ){
+    rc = vdbeSorterSort(pTask, pList);
   }
 
   if( rc==SQLITE_OK ){
-    i64 iOff = pSorter->iWriteOff;
     SorterRecord *p;
     SorterRecord *pNext = 0;
-    static const char eightZeros[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 
-    pSorter->nPMA++;
-    rc = vdbeSorterWriteVarint(pSorter->pTemp1, pSorter->nInMemory, &iOff);
-    for(p=pSorter->pRecord; rc==SQLITE_OK && p; p=pNext){
-      pNext = p->pNext;
-      rc = vdbeSorterWriteVarint(pSorter->pTemp1, p->nVal, &iOff);
+    vdbePmaWriterInit(pTask->file.pFd, &writer, pTask->pSorter->pgsz,
+                      pTask->file.iEof);
+    pTask->nPMA++;
+    vdbePmaWriteVarint(&writer, pList->szPMA);
+    for(p=pList->pList; p; p=pNext){
+      pNext = p->u.pNext;
+      vdbePmaWriteVarint(&writer, p->nVal);
+      vdbePmaWriteBlob(&writer, SRVAL(p), p->nVal);
+      if( pList->aMemory==0 ) sqlite3_free(p);
+    }
+    pList->pList = p;
+    rc = vdbePmaWriterFinish(&writer, &pTask->file.iEof);
+  }
 
-      if( rc==SQLITE_OK ){
-        rc = sqlite3OsWrite(pSorter->pTemp1, p->pVal, p->nVal, iOff);
-        iOff += p->nVal;
+  vdbeSorterWorkDebug(pTask, "exit");
+  assert( rc!=SQLITE_OK || pList->pList==0 );
+  assert( rc!=SQLITE_OK || pTask->file.iEof==iSz );
+  return rc;
+}
+
+/*
+** Advance the MergeEngine to its next entry.
+** Set *pbEof to true there is no next entry because
+** the MergeEngine has reached the end of all its inputs.
+**
+** Return SQLITE_OK if successful or an error code if an error occurs.
+*/
+static int vdbeMergeEngineStep(
+  MergeEngine *pMerger,      /* The merge engine to advance to the next row */
+  int *pbEof                 /* Set TRUE at EOF.  Set false for more content */
+){
+  int rc;
+  int iPrev = pMerger->aTree[1];/* Index of PmaReader to advance */
+  SortSubtask *pTask = pMerger->pTask;
+
+  /* Advance the current PmaReader */
+  rc = vdbePmaReaderNext(&pMerger->aReadr[iPrev]);
+
+  /* Update contents of aTree[] */
+  if( rc==SQLITE_OK ){
+    int i;                      /* Index of aTree[] to recalculate */
+    PmaReader *pReadr1;         /* First PmaReader to compare */
+    PmaReader *pReadr2;         /* Second PmaReader to compare */
+    int bCached = 0;
+
+    /* Find the first two PmaReaders to compare. The one that was just
+    ** advanced (iPrev) and the one next to it in the array.  */
+    pReadr1 = &pMerger->aReadr[(iPrev & 0xFFFE)];
+    pReadr2 = &pMerger->aReadr[(iPrev | 0x0001)];
+
+    for(i=(pMerger->nTree+iPrev)/2; i>0; i=i/2){
+      /* Compare pReadr1 and pReadr2. Store the result in variable iRes. */
+      int iRes;
+      if( pReadr1->pFd==0 ){
+        iRes = +1;
+      }else if( pReadr2->pFd==0 ){
+        iRes = -1;
+      }else{
+        iRes = pTask->xCompare(pTask, &bCached,
+            pReadr1->aKey, pReadr1->nKey, pReadr2->aKey, pReadr2->nKey
+        );
       }
 
-      sqlite3DbFree(db, p);
+      /* If pReadr1 contained the smaller value, set aTree[i] to its index.
+      ** Then set pReadr2 to the next PmaReader to compare to pReadr1. In this
+      ** case there is no cache of pReadr2 in pTask->pUnpacked, so set
+      ** pKey2 to point to the record belonging to pReadr2.
+      **
+      ** Alternatively, if pReadr2 contains the smaller of the two values,
+      ** set aTree[i] to its index and update pReadr1. If vdbeSorterCompare()
+      ** was actually called above, then pTask->pUnpacked now contains
+      ** a value equivalent to pReadr2. So set pKey2 to NULL to prevent
+      ** vdbeSorterCompare() from decoding pReadr2 again.
+      **
+      ** If the two values were equal, then the value from the oldest
+      ** PMA should be considered smaller. The VdbeSorter.aReadr[] array
+      ** is sorted from oldest to newest, so pReadr1 contains older values
+      ** than pReadr2 iff (pReadr1<pReadr2).  */
+      if( iRes<0 || (iRes==0 && pReadr1<pReadr2) ){
+        pMerger->aTree[i] = (int)(pReadr1 - pMerger->aReadr);
+        pReadr2 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];
+        bCached = 0;
+      }else{
+        if( pReadr1->pFd ) bCached = 0;
+        pMerger->aTree[i] = (int)(pReadr2 - pMerger->aReadr);
+        pReadr1 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];
+      }
     }
+    *pbEof = (pMerger->aReadr[pMerger->aTree[1]].pFd==0);
+  }
 
-    /* This assert verifies that unless an error has occurred, the size of 
-    ** the PMA on disk is the same as the expected size stored in
-    ** pSorter->nInMemory. */ 
-    assert( rc!=SQLITE_OK || pSorter->nInMemory==(
-          iOff-pSorter->iWriteOff-sqlite3VarintLen(pSorter->nInMemory)
-    ));
+  return (rc==SQLITE_OK ? pTask->pUnpacked->errCode : rc);
+}
 
-    pSorter->iWriteOff = iOff;
-    if( rc==SQLITE_OK ){
-      /* Terminate each file with 8 extra bytes so that from any offset
-      ** in the file we can always read 9 bytes without a SHORT_READ error */
-      rc = sqlite3OsWrite(pSorter->pTemp1, eightZeros, 8, iOff);
+#if SQLITE_MAX_WORKER_THREADS>0
+/*
+** The main routine for background threads that write level-0 PMAs.
+*/
+static void *vdbeSorterFlushThread(void *pCtx){
+  SortSubtask *pTask = (SortSubtask*)pCtx;
+  int rc;                         /* Return code */
+  assert( pTask->bDone==0 );
+  rc = vdbeSorterListToPMA(pTask, &pTask->list);
+  pTask->bDone = 1;
+  return SQLITE_INT_TO_PTR(rc);
+}
+#endif /* SQLITE_MAX_WORKER_THREADS>0 */
+
+/*
+** Flush the current contents of VdbeSorter.list to a new PMA, possibly
+** using a background thread.
+*/
+static int vdbeSorterFlushPMA(VdbeSorter *pSorter){
+#if SQLITE_MAX_WORKER_THREADS==0
+  pSorter->bUsePMA = 1;
+  return vdbeSorterListToPMA(&pSorter->aTask[0], &pSorter->list);
+#else
+  int rc = SQLITE_OK;
+  int i;
+  SortSubtask *pTask = 0;    /* Thread context used to create new PMA */
+  int nWorker = (pSorter->nTask-1);
+
+  /* Set the flag to indicate that at least one PMA has been written. 
+  ** Or will be, anyhow.  */
+  pSorter->bUsePMA = 1;
+
+  /* Select a sub-task to sort and flush the current list of in-memory
+  ** records to disk. If the sorter is running in multi-threaded mode,
+  ** round-robin between the first (pSorter->nTask-1) tasks. Except, if
+  ** the background thread from a sub-tasks previous turn is still running,
+  ** skip it. If the first (pSorter->nTask-1) sub-tasks are all still busy,
+  ** fall back to using the final sub-task. The first (pSorter->nTask-1)
+  ** sub-tasks are prefered as they use background threads - the final 
+  ** sub-task uses the main thread. */
+  for(i=0; i<nWorker; i++){
+    int iTest = (pSorter->iPrev + i + 1) % nWorker;
+    pTask = &pSorter->aTask[iTest];
+    if( pTask->bDone ){
+      rc = vdbeSorterJoinThread(pTask);
+    }
+    if( rc!=SQLITE_OK || pTask->pThread==0 ) break;
+  }
+
+  if( rc==SQLITE_OK ){
+    if( i==nWorker ){
+      /* Use the foreground thread for this operation */
+      rc = vdbeSorterListToPMA(&pSorter->aTask[nWorker], &pSorter->list);
+    }else{
+      /* Launch a background thread for this operation */
+      u8 *aMem = pTask->list.aMemory;
+      void *pCtx = (void*)pTask;
+
+      assert( pTask->pThread==0 && pTask->bDone==0 );
+      assert( pTask->list.pList==0 );
+      assert( pTask->list.aMemory==0 || pSorter->list.aMemory!=0 );
+
+      pSorter->iPrev = (u8)(pTask - pSorter->aTask);
+      pTask->list = pSorter->list;
+      pSorter->list.pList = 0;
+      pSorter->list.szPMA = 0;
+      if( aMem ){
+        pSorter->list.aMemory = aMem;
+        pSorter->nMemory = sqlite3MallocSize(aMem);
+      }else if( pSorter->list.aMemory ){
+        pSorter->list.aMemory = sqlite3Malloc(pSorter->nMemory);
+        if( !pSorter->list.aMemory ) return SQLITE_NOMEM_BKPT;
+      }
+
+      rc = vdbeSorterCreateThread(pTask, vdbeSorterFlushThread, pCtx);
     }
-    pSorter->pRecord = p;
   }
 
   return rc;
+#endif /* SQLITE_MAX_WORKER_THREADS!=0 */
 }
 
 /*
 ** Add a record to the sorter.
 */
 SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
-  sqlite3 *db,                    /* Database handle */
-  VdbeCursor *pCsr,               /* Sorter cursor */
+  const VdbeCursor *pCsr,         /* Sorter cursor */
   Mem *pVal                       /* Memory cell containing record */
 ){
-  VdbeSorter *pSorter = pCsr->pSorter;
+  VdbeSorter *pSorter;
   int rc = SQLITE_OK;             /* Return Code */
   SorterRecord *pNew;             /* New list element */
-
-  assert( pSorter );
-  pSorter->nInMemory += sqlite3VarintLen(pVal->n) + pVal->n;
-
-  pNew = (SorterRecord *)sqlite3DbMallocRaw(db, pVal->n + sizeof(SorterRecord));
-  if( pNew==0 ){
-    rc = SQLITE_NOMEM;
+  int bFlush;                     /* True to flush contents of memory to PMA */
+  int nReq;                       /* Bytes of memory required */
+  int nPMA;                       /* Bytes of PMA space required */
+  int t;                          /* serial type of first record field */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  getVarint32((const u8*)&pVal->z[1], t);
+  if( t>0 && t<10 && t!=7 ){
+    pSorter->typeMask &= SORTER_TYPE_INTEGER;
+  }else if( t>10 && (t & 0x01) ){
+    pSorter->typeMask &= SORTER_TYPE_TEXT;
   }else{
-    pNew->pVal = (void *)&pNew[1];
-    memcpy(pNew->pVal, pVal->z, pVal->n);
-    pNew->nVal = pVal->n;
-    pNew->pNext = pSorter->pRecord;
-    pSorter->pRecord = pNew;
+    pSorter->typeMask = 0;
   }
 
-  /* See if the contents of the sorter should now be written out. They
-  ** are written out when either of the following are true:
+  assert( pSorter );
+
+  /* Figure out whether or not the current contents of memory should be
+  ** flushed to a PMA before continuing. If so, do so.
+  **
+  ** If using the single large allocation mode (pSorter->aMemory!=0), then
+  ** flush the contents of memory to a new PMA if (a) at least one value is
+  ** already in memory and (b) the new value will not fit in memory.
+  ** 
+  ** Or, if using separate allocations for each record, flush the contents
+  ** of memory to a PMA if either of the following are true:
   **
   **   * The total memory allocated for the in-memory list is greater 
   **     than (page-size * cache-size), or
@@ -70805,490 +86420,954 @@ SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
   **   * The total memory allocated for the in-memory list is greater 
   **     than (page-size * 10) and sqlite3HeapNearlyFull() returns true.
   */
-  if( rc==SQLITE_OK && pSorter->mxPmaSize>0 && (
-        (pSorter->nInMemory>pSorter->mxPmaSize)
-     || (pSorter->nInMemory>pSorter->mnPmaSize && sqlite3HeapNearlyFull())
-  )){
-    rc = vdbeSorterListToPMA(db, pCsr);
-    pSorter->nInMemory = 0;
+  nReq = pVal->n + sizeof(SorterRecord);
+  nPMA = pVal->n + sqlite3VarintLen(pVal->n);
+  if( pSorter->mxPmaSize ){
+    if( pSorter->list.aMemory ){
+      bFlush = pSorter->iMemory && (pSorter->iMemory+nReq) > pSorter->mxPmaSize;
+    }else{
+      bFlush = (
+          (pSorter->list.szPMA > pSorter->mxPmaSize)
+       || (pSorter->list.szPMA > pSorter->mnPmaSize && sqlite3HeapNearlyFull())
+      );
+    }
+    if( bFlush ){
+      rc = vdbeSorterFlushPMA(pSorter);
+      pSorter->list.szPMA = 0;
+      pSorter->iMemory = 0;
+      assert( rc!=SQLITE_OK || pSorter->list.pList==0 );
+    }
   }
 
-  return rc;
-}
+  pSorter->list.szPMA += nPMA;
+  if( nPMA>pSorter->mxKeysize ){
+    pSorter->mxKeysize = nPMA;
+  }
 
-/*
-** Helper function for sqlite3VdbeSorterRewind(). 
-*/
-static int vdbeSorterInitMerge(
-  sqlite3 *db,                    /* Database handle */
-  VdbeCursor *pCsr,               /* Cursor handle for this sorter */
-  i64 *pnByte                     /* Sum of bytes in all opened PMAs */
-){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  int rc = SQLITE_OK;             /* Return code */
-  int i;                          /* Used to iterator through aIter[] */
-  i64 nByte = 0;                  /* Total bytes in all opened PMAs */
+  if( pSorter->list.aMemory ){
+    int nMin = pSorter->iMemory + nReq;
 
-  /* Initialize the iterators. */
-  for(i=0; i<SORTER_MAX_MERGE_COUNT; i++){
-    VdbeSorterIter *pIter = &pSorter->aIter[i];
-    rc = vdbeSorterIterInit(db, pSorter, pSorter->iReadOff, pIter, &nByte);
-    pSorter->iReadOff = pIter->iEof;
-    assert( rc!=SQLITE_OK || pSorter->iReadOff<=pSorter->iWriteOff );
-    if( rc!=SQLITE_OK || pSorter->iReadOff>=pSorter->iWriteOff ) break;
-  }
+    if( nMin>pSorter->nMemory ){
+      u8 *aNew;
+      int iListOff = (u8*)pSorter->list.pList - pSorter->list.aMemory;
+      int nNew = pSorter->nMemory * 2;
+      while( nNew < nMin ) nNew = nNew*2;
+      if( nNew > pSorter->mxPmaSize ) nNew = pSorter->mxPmaSize;
+      if( nNew < nMin ) nNew = nMin;
+
+      aNew = sqlite3Realloc(pSorter->list.aMemory, nNew);
+      if( !aNew ) return SQLITE_NOMEM_BKPT;
+      pSorter->list.pList = (SorterRecord*)&aNew[iListOff];
+      pSorter->list.aMemory = aNew;
+      pSorter->nMemory = nNew;
+    }
 
-  /* Initialize the aTree[] array. */
-  for(i=pSorter->nTree-1; rc==SQLITE_OK && i>0; i--){
-    rc = vdbeSorterDoCompare(pCsr, i);
+    pNew = (SorterRecord*)&pSorter->list.aMemory[pSorter->iMemory];
+    pSorter->iMemory += ROUND8(nReq);
+    if( pSorter->list.pList ){
+      pNew->u.iNext = (int)((u8*)(pSorter->list.pList) - pSorter->list.aMemory);
+    }
+  }else{
+    pNew = (SorterRecord *)sqlite3Malloc(nReq);
+    if( pNew==0 ){
+      return SQLITE_NOMEM_BKPT;
+    }
+    pNew->u.pNext = pSorter->list.pList;
   }
 
-  *pnByte = nByte;
+  memcpy(SRVAL(pNew), pVal->z, pVal->n);
+  pNew->nVal = pVal->n;
+  pSorter->list.pList = pNew;
+
   return rc;
 }
 
 /*
-** Once the sorter has been populated, this function is called to prepare
-** for iterating through its contents in sorted order.
+** Read keys from pIncr->pMerger and populate pIncr->aFile[1]. The format
+** of the data stored in aFile[1] is the same as that used by regular PMAs,
+** except that the number-of-bytes varint is omitted from the start.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterRewind(sqlite3 *db, VdbeCursor *pCsr, int *pbEof){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  int rc;                         /* Return code */
-  sqlite3_file *pTemp2 = 0;       /* Second temp file to use */
-  i64 iWrite2 = 0;                /* Write offset for pTemp2 */
-  int nIter;                      /* Number of iterators used */
-  int nByte;                      /* Bytes of space required for aIter/aTree */
-  int N = 2;                      /* Power of 2 >= nIter */
+static int vdbeIncrPopulate(IncrMerger *pIncr){
+  int rc = SQLITE_OK;
+  int rc2;
+  i64 iStart = pIncr->iStartOff;
+  SorterFile *pOut = &pIncr->aFile[1];
+  SortSubtask *pTask = pIncr->pTask;
+  MergeEngine *pMerger = pIncr->pMerger;
+  PmaWriter writer;
+  assert( pIncr->bEof==0 );
 
-  assert( pSorter );
+  vdbeSorterPopulateDebug(pTask, "enter");
 
-  /* If no data has been written to disk, then do not do so now. Instead,
-  ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly
-  ** from the in-memory list.  */
-  if( pSorter->nPMA==0 ){
-    *pbEof = !pSorter->pRecord;
-    assert( pSorter->aTree==0 );
-    return vdbeSorterSort(pCsr);
-  }
+  vdbePmaWriterInit(pOut->pFd, &writer, pTask->pSorter->pgsz, iStart);
+  while( rc==SQLITE_OK ){
+    int dummy;
+    PmaReader *pReader = &pMerger->aReadr[ pMerger->aTree[1] ];
+    int nKey = pReader->nKey;
+    i64 iEof = writer.iWriteOff + writer.iBufEnd;
 
-  /* Write the current b-tree to a PMA. Close the b-tree cursor. */
-  rc = vdbeSorterListToPMA(db, pCsr);
-  if( rc!=SQLITE_OK ) return rc;
+    /* Check if the output file is full or if the input has been exhausted.
+    ** In either case exit the loop. */
+    if( pReader->pFd==0 ) break;
+    if( (iEof + nKey + sqlite3VarintLen(nKey))>(iStart + pIncr->mxSz) ) break;
 
-  /* Allocate space for aIter[] and aTree[]. */
-  nIter = pSorter->nPMA;
-  if( nIter>SORTER_MAX_MERGE_COUNT ) nIter = SORTER_MAX_MERGE_COUNT;
-  assert( nIter>0 );
-  while( N<nIter ) N += N;
-  nByte = N * (sizeof(int) + sizeof(VdbeSorterIter));
-  pSorter->aIter = (VdbeSorterIter *)sqlite3DbMallocZero(db, nByte);
-  if( !pSorter->aIter ) return SQLITE_NOMEM;
-  pSorter->aTree = (int *)&pSorter->aIter[N];
-  pSorter->nTree = N;
+    /* Write the next key to the output. */
+    vdbePmaWriteVarint(&writer, nKey);
+    vdbePmaWriteBlob(&writer, pReader->aKey, nKey);
+    assert( pIncr->pMerger->pTask==pTask );
+    rc = vdbeMergeEngineStep(pIncr->pMerger, &dummy);
+  }
 
-  do {
-    int iNew;                     /* Index of new, merged, PMA */
+  rc2 = vdbePmaWriterFinish(&writer, &pOut->iEof);
+  if( rc==SQLITE_OK ) rc = rc2;
+  vdbeSorterPopulateDebug(pTask, "exit");
+  return rc;
+}
 
-    for(iNew=0; 
-        rc==SQLITE_OK && iNew*SORTER_MAX_MERGE_COUNT<pSorter->nPMA; 
-        iNew++
-    ){
-      i64 nWrite;                 /* Number of bytes in new PMA */
+#if SQLITE_MAX_WORKER_THREADS>0
+/*
+** The main routine for background threads that populate aFile[1] of
+** multi-threaded IncrMerger objects.
+*/
+static void *vdbeIncrPopulateThread(void *pCtx){
+  IncrMerger *pIncr = (IncrMerger*)pCtx;
+  void *pRet = SQLITE_INT_TO_PTR( vdbeIncrPopulate(pIncr) );
+  pIncr->pTask->bDone = 1;
+  return pRet;
+}
 
-      /* If there are SORTER_MAX_MERGE_COUNT or less PMAs in file pTemp1,
-      ** initialize an iterator for each of them and break out of the loop.
-      ** These iterators will be incrementally merged as the VDBE layer calls
-      ** sqlite3VdbeSorterNext().
-      **
-      ** Otherwise, if pTemp1 contains more than SORTER_MAX_MERGE_COUNT PMAs,
-      ** initialize interators for SORTER_MAX_MERGE_COUNT of them. These PMAs
-      ** are merged into a single PMA that is written to file pTemp2.
-      */
-      rc = vdbeSorterInitMerge(db, pCsr, &nWrite);
-      assert( rc!=SQLITE_OK || pSorter->aIter[ pSorter->aTree[1] ].pFile );
-      if( rc!=SQLITE_OK || pSorter->nPMA<=SORTER_MAX_MERGE_COUNT ){
-        break;
-      }
+/*
+** Launch a background thread to populate aFile[1] of pIncr.
+*/
+static int vdbeIncrBgPopulate(IncrMerger *pIncr){
+  void *p = (void*)pIncr;
+  assert( pIncr->bUseThread );
+  return vdbeSorterCreateThread(pIncr->pTask, vdbeIncrPopulateThread, p);
+}
+#endif
 
-      /* Open the second temp file, if it is not already open. */
-      if( pTemp2==0 ){
-        assert( iWrite2==0 );
-        rc = vdbeSorterOpenTempFile(db, &pTemp2);
-      }
+/*
+** This function is called when the PmaReader corresponding to pIncr has
+** finished reading the contents of aFile[0]. Its purpose is to "refill"
+** aFile[0] such that the PmaReader should start rereading it from the
+** beginning.
+**
+** For single-threaded objects, this is accomplished by literally reading 
+** keys from pIncr->pMerger and repopulating aFile[0]. 
+**
+** For multi-threaded objects, all that is required is to wait until the 
+** background thread is finished (if it is not already) and then swap 
+** aFile[0] and aFile[1] in place. If the contents of pMerger have not
+** been exhausted, this function also launches a new background thread
+** to populate the new aFile[1].
+**
+** SQLITE_OK is returned on success, or an SQLite error code otherwise.
+*/
+static int vdbeIncrSwap(IncrMerger *pIncr){
+  int rc = SQLITE_OK;
 
-      if( rc==SQLITE_OK ){
-        rc = vdbeSorterWriteVarint(pTemp2, nWrite, &iWrite2);
-      }
+#if SQLITE_MAX_WORKER_THREADS>0
+  if( pIncr->bUseThread ){
+    rc = vdbeSorterJoinThread(pIncr->pTask);
 
-      if( rc==SQLITE_OK ){
-        int bEof = 0;
-        while( rc==SQLITE_OK && bEof==0 ){
-          int nToWrite;
-          VdbeSorterIter *pIter = &pSorter->aIter[ pSorter->aTree[1] ];
-          assert( pIter->pFile );
-          nToWrite = pIter->nKey + sqlite3VarintLen(pIter->nKey);
-          rc = sqlite3OsWrite(pTemp2, pIter->aAlloc, nToWrite, iWrite2);
-          iWrite2 += nToWrite;
-          if( rc==SQLITE_OK ){
-            rc = sqlite3VdbeSorterNext(db, pCsr, &bEof);
-          }
-        }
-      }
+    if( rc==SQLITE_OK ){
+      SorterFile f0 = pIncr->aFile[0];
+      pIncr->aFile[0] = pIncr->aFile[1];
+      pIncr->aFile[1] = f0;
     }
 
-    if( pSorter->nPMA<=SORTER_MAX_MERGE_COUNT ){
-      break;
-    }else{
-      sqlite3_file *pTmp = pSorter->pTemp1;
-      pSorter->nPMA = iNew;
-      pSorter->pTemp1 = pTemp2;
-      pTemp2 = pTmp;
-      pSorter->iWriteOff = iWrite2;
-      pSorter->iReadOff = 0;
-      iWrite2 = 0;
+    if( rc==SQLITE_OK ){
+      if( pIncr->aFile[0].iEof==pIncr->iStartOff ){
+        pIncr->bEof = 1;
+      }else{
+        rc = vdbeIncrBgPopulate(pIncr);
+      }
+    }
+  }else
+#endif
+  {
+    rc = vdbeIncrPopulate(pIncr);
+    pIncr->aFile[0] = pIncr->aFile[1];
+    if( pIncr->aFile[0].iEof==pIncr->iStartOff ){
+      pIncr->bEof = 1;
     }
-  }while( rc==SQLITE_OK );
-
-  if( pTemp2 ){
-    sqlite3OsCloseFree(pTemp2);
   }
-  *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
+
   return rc;
 }
 
 /*
-** Advance to the next element in the sorter.
+** Allocate and return a new IncrMerger object to read data from pMerger.
+**
+** If an OOM condition is encountered, return NULL. In this case free the
+** pMerger argument before returning.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, VdbeCursor *pCsr, int *pbEof){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  int rc;                         /* Return code */
-
-  if( pSorter->aTree ){
-    int iPrev = pSorter->aTree[1];/* Index of iterator to advance */
-    int i;                        /* Index of aTree[] to recalculate */
-
-    rc = vdbeSorterIterNext(db, &pSorter->aIter[iPrev]);
-    for(i=(pSorter->nTree+iPrev)/2; rc==SQLITE_OK && i>0; i=i/2){
-      rc = vdbeSorterDoCompare(pCsr, i);
-    }
-
-    *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
+static int vdbeIncrMergerNew(
+  SortSubtask *pTask,     /* The thread that will be using the new IncrMerger */
+  MergeEngine *pMerger,   /* The MergeEngine that the IncrMerger will control */
+  IncrMerger **ppOut      /* Write the new IncrMerger here */
+){
+  int rc = SQLITE_OK;
+  IncrMerger *pIncr = *ppOut = (IncrMerger*)
+       (sqlite3FaultSim(100) ? 0 : sqlite3MallocZero(sizeof(*pIncr)));
+  if( pIncr ){
+    pIncr->pMerger = pMerger;
+    pIncr->pTask = pTask;
+    pIncr->mxSz = MAX(pTask->pSorter->mxKeysize+9,pTask->pSorter->mxPmaSize/2);
+    pTask->file2.iEof += pIncr->mxSz;
   }else{
-    SorterRecord *pFree = pSorter->pRecord;
-    pSorter->pRecord = pFree->pNext;
-    pFree->pNext = 0;
-    vdbeSorterRecordFree(db, pFree);
-    *pbEof = !pSorter->pRecord;
-    rc = SQLITE_OK;
+    vdbeMergeEngineFree(pMerger);
+    rc = SQLITE_NOMEM_BKPT;
   }
   return rc;
 }
 
+#if SQLITE_MAX_WORKER_THREADS>0
 /*
-** Return a pointer to a buffer owned by the sorter that contains the 
-** current key.
+** Set the "use-threads" flag on object pIncr.
 */
-static void *vdbeSorterRowkey(
-  VdbeSorter *pSorter,            /* Sorter object */
-  int *pnKey                      /* OUT: Size of current key in bytes */
-){
-  void *pKey;
-  if( pSorter->aTree ){
-    VdbeSorterIter *pIter;
-    pIter = &pSorter->aIter[ pSorter->aTree[1] ];
-    *pnKey = pIter->nKey;
-    pKey = pIter->aKey;
-  }else{
-    *pnKey = pSorter->pRecord->nVal;
-    pKey = pSorter->pRecord->pVal;
-  }
-  return pKey;
+static void vdbeIncrMergerSetThreads(IncrMerger *pIncr){
+  pIncr->bUseThread = 1;
+  pIncr->pTask->file2.iEof -= pIncr->mxSz;
 }
+#endif /* SQLITE_MAX_WORKER_THREADS>0 */
+
+
 
 /*
-** Copy the current sorter key into the memory cell pOut.
+** Recompute pMerger->aTree[iOut] by comparing the next keys on the
+** two PmaReaders that feed that entry.  Neither of the PmaReaders
+** are advanced.  This routine merely does the comparison.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  void *pKey; int nKey;           /* Sorter key to copy into pOut */
+static void vdbeMergeEngineCompare(
+  MergeEngine *pMerger,  /* Merge engine containing PmaReaders to compare */
+  int iOut               /* Store the result in pMerger->aTree[iOut] */
+){
+  int i1;
+  int i2;
+  int iRes;
+  PmaReader *p1;
+  PmaReader *p2;
 
-  pKey = vdbeSorterRowkey(pSorter, &nKey);
-  if( sqlite3VdbeMemGrow(pOut, nKey, 0) ){
-    return SQLITE_NOMEM;
+  assert( iOut<pMerger->nTree && iOut>0 );
+
+  if( iOut>=(pMerger->nTree/2) ){
+    i1 = (iOut - pMerger->nTree/2) * 2;
+    i2 = i1 + 1;
+  }else{
+    i1 = pMerger->aTree[iOut*2];
+    i2 = pMerger->aTree[iOut*2+1];
   }
-  pOut->n = nKey;
-  MemSetTypeFlag(pOut, MEM_Blob);
-  memcpy(pOut->z, pKey, nKey);
 
-  return SQLITE_OK;
+  p1 = &pMerger->aReadr[i1];
+  p2 = &pMerger->aReadr[i2];
+
+  if( p1->pFd==0 ){
+    iRes = i2;
+  }else if( p2->pFd==0 ){
+    iRes = i1;
+  }else{
+    SortSubtask *pTask = pMerger->pTask;
+    int bCached = 0;
+    int res;
+    assert( pTask->pUnpacked!=0 );  /* from vdbeSortSubtaskMain() */
+    res = pTask->xCompare(
+        pTask, &bCached, p1->aKey, p1->nKey, p2->aKey, p2->nKey
+    );
+    if( res<=0 ){
+      iRes = i1;
+    }else{
+      iRes = i2;
+    }
+  }
+
+  pMerger->aTree[iOut] = iRes;
 }
 
 /*
-** Compare the key in memory cell pVal with the key that the sorter cursor
-** passed as the first argument currently points to. For the purposes of
-** the comparison, ignore the rowid field at the end of each record.
+** Allowed values for the eMode parameter to vdbeMergeEngineInit()
+** and vdbePmaReaderIncrMergeInit().
 **
-** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).
-** Otherwise, set *pRes to a negative, zero or positive value if the
-** key in pVal is smaller than, equal to or larger than the current sorter
-** key.
+** Only INCRINIT_NORMAL is valid in single-threaded builds (when
+** SQLITE_MAX_WORKER_THREADS==0).  The other values are only used
+** when there exists one or more separate worker threads.
 */
-SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
-  VdbeCursor *pCsr,               /* Sorter cursor */
-  Mem *pVal,                      /* Value to compare to current sorter key */
-  int *pRes                       /* OUT: Result of comparison */
+#define INCRINIT_NORMAL 0
+#define INCRINIT_TASK   1
+#define INCRINIT_ROOT   2
+
+/* 
+** Forward reference required as the vdbeIncrMergeInit() and
+** vdbePmaReaderIncrInit() routines are called mutually recursively when
+** building a merge tree.
+*/
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode);
+
+/*
+** Initialize the MergeEngine object passed as the second argument. Once this
+** function returns, the first key of merged data may be read from the 
+** MergeEngine object in the usual fashion.
+**
+** If argument eMode is INCRINIT_ROOT, then it is assumed that any IncrMerge
+** objects attached to the PmaReader objects that the merger reads from have
+** already been populated, but that they have not yet populated aFile[0] and
+** set the PmaReader objects up to read from it. In this case all that is
+** required is to call vdbePmaReaderNext() on each PmaReader to point it at
+** its first key.
+**
+** Otherwise, if eMode is any value other than INCRINIT_ROOT, then use 
+** vdbePmaReaderIncrMergeInit() to initialize each PmaReader that feeds data 
+** to pMerger.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+static int vdbeMergeEngineInit(
+  SortSubtask *pTask,             /* Thread that will run pMerger */
+  MergeEngine *pMerger,           /* MergeEngine to initialize */
+  int eMode                       /* One of the INCRINIT_XXX constants */
 ){
-  VdbeSorter *pSorter = pCsr->pSorter;
-  void *pKey; int nKey;           /* Sorter key to compare pVal with */
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* For looping over PmaReader objects */
+  int nTree = pMerger->nTree;
+
+  /* eMode is always INCRINIT_NORMAL in single-threaded mode */
+  assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );
+
+  /* Verify that the MergeEngine is assigned to a single thread */
+  assert( pMerger->pTask==0 );
+  pMerger->pTask = pTask;
+
+  for(i=0; i<nTree; i++){
+    if( SQLITE_MAX_WORKER_THREADS>0 && eMode==INCRINIT_ROOT ){
+      /* PmaReaders should be normally initialized in order, as if they are
+      ** reading from the same temp file this makes for more linear file IO.
+      ** However, in the INCRINIT_ROOT case, if PmaReader aReadr[nTask-1] is
+      ** in use it will block the vdbePmaReaderNext() call while it uses
+      ** the main thread to fill its buffer. So calling PmaReaderNext()
+      ** on this PmaReader before any of the multi-threaded PmaReaders takes
+      ** better advantage of multi-processor hardware. */
+      rc = vdbePmaReaderNext(&pMerger->aReadr[nTree-i-1]);
+    }else{
+      rc = vdbePmaReaderIncrInit(&pMerger->aReadr[i], INCRINIT_NORMAL);
+    }
+    if( rc!=SQLITE_OK ) return rc;
+  }
 
-  pKey = vdbeSorterRowkey(pSorter, &nKey);
-  vdbeSorterCompare(pCsr, 1, pVal->z, pVal->n, pKey, nKey, pRes);
-  return SQLITE_OK;
+  for(i=pMerger->nTree-1; i>0; i--){
+    vdbeMergeEngineCompare(pMerger, i);
+  }
+  return pTask->pUnpacked->errCode;
 }
 
-#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */
-
-/************** End of vdbesort.c ********************************************/
-/************** Begin file journal.c *****************************************/
 /*
-** 2007 August 22
+** The PmaReader passed as the first argument is guaranteed to be an
+** incremental-reader (pReadr->pIncr!=0). This function serves to open
+** and/or initialize the temp file related fields of the IncrMerge
+** object at (pReadr->pIncr).
 **
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
+** If argument eMode is set to INCRINIT_NORMAL, then all PmaReaders
+** in the sub-tree headed by pReadr are also initialized. Data is then 
+** loaded into the buffers belonging to pReadr and it is set to point to 
+** the first key in its range.
 **
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
+** If argument eMode is set to INCRINIT_TASK, then pReadr is guaranteed
+** to be a multi-threaded PmaReader and this function is being called in a
+** background thread. In this case all PmaReaders in the sub-tree are 
+** initialized as for INCRINIT_NORMAL and the aFile[1] buffer belonging to
+** pReadr is populated. However, pReadr itself is not set up to point
+** to its first key. A call to vdbePmaReaderNext() is still required to do
+** that. 
 **
-*************************************************************************
+** The reason this function does not call vdbePmaReaderNext() immediately 
+** in the INCRINIT_TASK case is that vdbePmaReaderNext() assumes that it has
+** to block on thread (pTask->thread) before accessing aFile[1]. But, since
+** this entire function is being run by thread (pTask->thread), that will
+** lead to the current background thread attempting to join itself.
 **
-** This file implements a special kind of sqlite3_file object used
-** by SQLite to create journal files if the atomic-write optimization
-** is enabled.
+** Finally, if argument eMode is set to INCRINIT_ROOT, it may be assumed
+** that pReadr->pIncr is a multi-threaded IncrMerge objects, and that all
+** child-trees have already been initialized using IncrInit(INCRINIT_TASK).
+** In this case vdbePmaReaderNext() is called on all child PmaReaders and
+** the current PmaReader set to point to the first key in its range.
 **
-** The distinctive characteristic of this sqlite3_file is that the
-** actual on disk file is created lazily. When the file is created,
-** the caller specifies a buffer size for an in-memory buffer to
-** be used to service read() and write() requests. The actual file
-** on disk is not created or populated until either:
-**
-**   1) The in-memory representation grows too large for the allocated 
-**      buffer, or
-**   2) The sqlite3JournalCreate() function is called.
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
 */
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){
+  int rc = SQLITE_OK;
+  IncrMerger *pIncr = pReadr->pIncr;
+  SortSubtask *pTask = pIncr->pTask;
+  sqlite3 *db = pTask->pSorter->db;
+
+  /* eMode is always INCRINIT_NORMAL in single-threaded mode */
+  assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );
+
+  rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);
+
+  /* Set up the required files for pIncr. A multi-theaded IncrMerge object
+  ** requires two temp files to itself, whereas a single-threaded object
+  ** only requires a region of pTask->file2. */
+  if( rc==SQLITE_OK ){
+    int mxSz = pIncr->mxSz;
+#if SQLITE_MAX_WORKER_THREADS>0
+    if( pIncr->bUseThread ){
+      rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);
+      if( rc==SQLITE_OK ){
+        rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);
+      }
+    }else
+#endif
+    /*if( !pIncr->bUseThread )*/{
+      if( pTask->file2.pFd==0 ){
+        assert( pTask->file2.iEof>0 );
+        rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);
+        pTask->file2.iEof = 0;
+      }
+      if( rc==SQLITE_OK ){
+        pIncr->aFile[1].pFd = pTask->file2.pFd;
+        pIncr->iStartOff = pTask->file2.iEof;
+        pTask->file2.iEof += mxSz;
+      }
+    }
+  }
+
+#if SQLITE_MAX_WORKER_THREADS>0
+  if( rc==SQLITE_OK && pIncr->bUseThread ){
+    /* Use the current thread to populate aFile[1], even though this
+    ** PmaReader is multi-threaded. If this is an INCRINIT_TASK object,
+    ** then this function is already running in background thread 
+    ** pIncr->pTask->thread. 
+    **
+    ** If this is the INCRINIT_ROOT object, then it is running in the 
+    ** main VDBE thread. But that is Ok, as that thread cannot return
+    ** control to the VDBE or proceed with anything useful until the 
+    ** first results are ready from this merger object anyway.
+    */
+    assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );
+    rc = vdbeIncrPopulate(pIncr);
+  }
+#endif
+
+  if( rc==SQLITE_OK && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK) ){
+    rc = vdbePmaReaderNext(pReadr);
+  }
 
+  return rc;
+}
 
+#if SQLITE_MAX_WORKER_THREADS>0
 /*
-** A JournalFile object is a subclass of sqlite3_file used by
-** as an open file handle for journal files.
+** The main routine for vdbePmaReaderIncrMergeInit() operations run in 
+** background threads.
 */
-struct JournalFile {
-  sqlite3_io_methods *pMethod;    /* I/O methods on journal files */
-  int nBuf;                       /* Size of zBuf[] in bytes */
-  char *zBuf;                     /* Space to buffer journal writes */
-  int iSize;                      /* Amount of zBuf[] currently used */
-  int flags;                      /* xOpen flags */
-  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
-  sqlite3_file *pReal;            /* The "real" underlying file descriptor */
-  const char *zJournal;           /* Name of the journal file */
-};
-typedef struct JournalFile JournalFile;
+static void *vdbePmaReaderBgIncrInit(void *pCtx){
+  PmaReader *pReader = (PmaReader*)pCtx;
+  void *pRet = SQLITE_INT_TO_PTR(
+                  vdbePmaReaderIncrMergeInit(pReader,INCRINIT_TASK)
+               );
+  pReader->pIncr->pTask->bDone = 1;
+  return pRet;
+}
+#endif
 
 /*
-** If it does not already exists, create and populate the on-disk file 
-** for JournalFile p.
+** If the PmaReader passed as the first argument is not an incremental-reader
+** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it invokes
+** the vdbePmaReaderIncrMergeInit() function with the parameters passed to
+** this routine to initialize the incremental merge.
+** 
+** If the IncrMerger object is multi-threaded (IncrMerger.bUseThread==1), 
+** then a background thread is launched to call vdbePmaReaderIncrMergeInit().
+** Or, if the IncrMerger is single threaded, the same function is called
+** using the current thread.
 */
-static int createFile(JournalFile *p){
-  int rc = SQLITE_OK;
-  if( !p->pReal ){
-    sqlite3_file *pReal = (sqlite3_file *)&p[1];
-    rc = sqlite3OsOpen(p->pVfs, p->zJournal, pReal, p->flags, 0);
-    if( rc==SQLITE_OK ){
-      p->pReal = pReal;
-      if( p->iSize>0 ){
-        assert(p->iSize<=p->nBuf);
-        rc = sqlite3OsWrite(p->pReal, p->zBuf, p->iSize, 0);
-      }
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode){
+  IncrMerger *pIncr = pReadr->pIncr;   /* Incremental merger */
+  int rc = SQLITE_OK;                  /* Return code */
+  if( pIncr ){
+#if SQLITE_MAX_WORKER_THREADS>0
+    assert( pIncr->bUseThread==0 || eMode==INCRINIT_TASK );
+    if( pIncr->bUseThread ){
+      void *pCtx = (void*)pReadr;
+      rc = vdbeSorterCreateThread(pIncr->pTask, vdbePmaReaderBgIncrInit, pCtx);
+    }else
+#endif
+    {
+      rc = vdbePmaReaderIncrMergeInit(pReadr, eMode);
     }
   }
   return rc;
 }
 
 /*
-** Close the file.
+** Allocate a new MergeEngine object to merge the contents of nPMA level-0
+** PMAs from pTask->file. If no error occurs, set *ppOut to point to
+** the new object and return SQLITE_OK. Or, if an error does occur, set *ppOut
+** to NULL and return an SQLite error code.
+**
+** When this function is called, *piOffset is set to the offset of the
+** first PMA to read from pTask->file. Assuming no error occurs, it is 
+** set to the offset immediately following the last byte of the last
+** PMA before returning. If an error does occur, then the final value of
+** *piOffset is undefined.
 */
-static int jrnlClose(sqlite3_file *pJfd){
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    sqlite3OsClose(p->pReal);
+static int vdbeMergeEngineLevel0(
+  SortSubtask *pTask,             /* Sorter task to read from */
+  int nPMA,                       /* Number of PMAs to read */
+  i64 *piOffset,                  /* IN/OUT: Readr offset in pTask->file */
+  MergeEngine **ppOut             /* OUT: New merge-engine */
+){
+  MergeEngine *pNew;              /* Merge engine to return */
+  i64 iOff = *piOffset;
+  int i;
+  int rc = SQLITE_OK;
+
+  *ppOut = pNew = vdbeMergeEngineNew(nPMA);
+  if( pNew==0 ) rc = SQLITE_NOMEM_BKPT;
+
+  for(i=0; i<nPMA && rc==SQLITE_OK; i++){
+    i64 nDummy = 0;
+    PmaReader *pReadr = &pNew->aReadr[i];
+    rc = vdbePmaReaderInit(pTask, &pTask->file, iOff, pReadr, &nDummy);
+    iOff = pReadr->iEof;
   }
-  sqlite3_free(p->zBuf);
-  return SQLITE_OK;
+
+  if( rc!=SQLITE_OK ){
+    vdbeMergeEngineFree(pNew);
+    *ppOut = 0;
+  }
+  *piOffset = iOff;
+  return rc;
 }
 
 /*
-** Read data from the file.
+** Return the depth of a tree comprising nPMA PMAs, assuming a fanout of
+** SORTER_MAX_MERGE_COUNT. The returned value does not include leaf nodes.
+**
+** i.e.
+**
+**   nPMA<=16    -> TreeDepth() == 0
+**   nPMA<=256   -> TreeDepth() == 1
+**   nPMA<=65536 -> TreeDepth() == 2
 */
-static int jrnlRead(
-  sqlite3_file *pJfd,    /* The journal file from which to read */
-  void *zBuf,            /* Put the results here */
-  int iAmt,              /* Number of bytes to read */
-  sqlite_int64 iOfst     /* Begin reading at this offset */
+static int vdbeSorterTreeDepth(int nPMA){
+  int nDepth = 0;
+  i64 nDiv = SORTER_MAX_MERGE_COUNT;
+  while( nDiv < (i64)nPMA ){
+    nDiv = nDiv * SORTER_MAX_MERGE_COUNT;
+    nDepth++;
+  }
+  return nDepth;
+}
+
+/*
+** pRoot is the root of an incremental merge-tree with depth nDepth (according
+** to vdbeSorterTreeDepth()). pLeaf is the iSeq'th leaf to be added to the
+** tree, counting from zero. This function adds pLeaf to the tree.
+**
+** If successful, SQLITE_OK is returned. If an error occurs, an SQLite error
+** code is returned and pLeaf is freed.
+*/
+static int vdbeSorterAddToTree(
+  SortSubtask *pTask,             /* Task context */
+  int nDepth,                     /* Depth of tree according to TreeDepth() */
+  int iSeq,                       /* Sequence number of leaf within tree */
+  MergeEngine *pRoot,             /* Root of tree */
+  MergeEngine *pLeaf              /* Leaf to add to tree */
 ){
   int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
-  }else if( (iAmt+iOfst)>p->iSize ){
-    rc = SQLITE_IOERR_SHORT_READ;
+  int nDiv = 1;
+  int i;
+  MergeEngine *p = pRoot;
+  IncrMerger *pIncr;
+
+  rc = vdbeIncrMergerNew(pTask, pLeaf, &pIncr);
+
+  for(i=1; i<nDepth; i++){
+    nDiv = nDiv * SORTER_MAX_MERGE_COUNT;
+  }
+
+  for(i=1; i<nDepth && rc==SQLITE_OK; i++){
+    int iIter = (iSeq / nDiv) % SORTER_MAX_MERGE_COUNT;
+    PmaReader *pReadr = &p->aReadr[iIter];
+
+    if( pReadr->pIncr==0 ){
+      MergeEngine *pNew = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);
+      if( pNew==0 ){
+        rc = SQLITE_NOMEM_BKPT;
+      }else{
+        rc = vdbeIncrMergerNew(pTask, pNew, &pReadr->pIncr);
+      }
+    }
+    if( rc==SQLITE_OK ){
+      p = pReadr->pIncr->pMerger;
+      nDiv = nDiv / SORTER_MAX_MERGE_COUNT;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    p->aReadr[iSeq % SORTER_MAX_MERGE_COUNT].pIncr = pIncr;
   }else{
-    memcpy(zBuf, &p->zBuf[iOfst], iAmt);
+    vdbeIncrFree(pIncr);
   }
   return rc;
 }
 
 /*
-** Write data to the file.
+** This function is called as part of a SorterRewind() operation on a sorter
+** that has already written two or more level-0 PMAs to one or more temp
+** files. It builds a tree of MergeEngine/IncrMerger/PmaReader objects that 
+** can be used to incrementally merge all PMAs on disk.
+**
+** If successful, SQLITE_OK is returned and *ppOut set to point to the
+** MergeEngine object at the root of the tree before returning. Or, if an
+** error occurs, an SQLite error code is returned and the final value 
+** of *ppOut is undefined.
 */
-static int jrnlWrite(
-  sqlite3_file *pJfd,    /* The journal file into which to write */
-  const void *zBuf,      /* Take data to be written from here */
-  int iAmt,              /* Number of bytes to write */
-  sqlite_int64 iOfst     /* Begin writing at this offset into the file */
+static int vdbeSorterMergeTreeBuild(
+  VdbeSorter *pSorter,       /* The VDBE cursor that implements the sort */
+  MergeEngine **ppOut        /* Write the MergeEngine here */
 ){
+  MergeEngine *pMain = 0;
   int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( !p->pReal && (iOfst+iAmt)>p->nBuf ){
-    rc = createFile(p);
+  int iTask;
+
+#if SQLITE_MAX_WORKER_THREADS>0
+  /* If the sorter uses more than one task, then create the top-level 
+  ** MergeEngine here. This MergeEngine will read data from exactly 
+  ** one PmaReader per sub-task.  */
+  assert( pSorter->bUseThreads || pSorter->nTask==1 );
+  if( pSorter->nTask>1 ){
+    pMain = vdbeMergeEngineNew(pSorter->nTask);
+    if( pMain==0 ) rc = SQLITE_NOMEM_BKPT;
   }
-  if( rc==SQLITE_OK ){
-    if( p->pReal ){
-      rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
-    }else{
-      memcpy(&p->zBuf[iOfst], zBuf, iAmt);
-      if( p->iSize<(iOfst+iAmt) ){
-        p->iSize = (iOfst+iAmt);
+#endif
+
+  for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){
+    SortSubtask *pTask = &pSorter->aTask[iTask];
+    assert( pTask->nPMA>0 || SQLITE_MAX_WORKER_THREADS>0 );
+    if( SQLITE_MAX_WORKER_THREADS==0 || pTask->nPMA ){
+      MergeEngine *pRoot = 0;     /* Root node of tree for this task */
+      int nDepth = vdbeSorterTreeDepth(pTask->nPMA);
+      i64 iReadOff = 0;
+
+      if( pTask->nPMA<=SORTER_MAX_MERGE_COUNT ){
+        rc = vdbeMergeEngineLevel0(pTask, pTask->nPMA, &iReadOff, &pRoot);
+      }else{
+        int i;
+        int iSeq = 0;
+        pRoot = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);
+        if( pRoot==0 ) rc = SQLITE_NOMEM_BKPT;
+        for(i=0; i<pTask->nPMA && rc==SQLITE_OK; i += SORTER_MAX_MERGE_COUNT){
+          MergeEngine *pMerger = 0; /* New level-0 PMA merger */
+          int nReader;              /* Number of level-0 PMAs to merge */
+
+          nReader = MIN(pTask->nPMA - i, SORTER_MAX_MERGE_COUNT);
+          rc = vdbeMergeEngineLevel0(pTask, nReader, &iReadOff, &pMerger);
+          if( rc==SQLITE_OK ){
+            rc = vdbeSorterAddToTree(pTask, nDepth, iSeq++, pRoot, pMerger);
+          }
+        }
+      }
+
+      if( rc==SQLITE_OK ){
+#if SQLITE_MAX_WORKER_THREADS>0
+        if( pMain!=0 ){
+          rc = vdbeIncrMergerNew(pTask, pRoot, &pMain->aReadr[iTask].pIncr);
+        }else
+#endif
+        {
+          assert( pMain==0 );
+          pMain = pRoot;
+        }
+      }else{
+        vdbeMergeEngineFree(pRoot);
       }
     }
   }
+
+  if( rc!=SQLITE_OK ){
+    vdbeMergeEngineFree(pMain);
+    pMain = 0;
+  }
+  *ppOut = pMain;
   return rc;
 }
 
 /*
-** Truncate the file.
+** This function is called as part of an sqlite3VdbeSorterRewind() operation
+** on a sorter that has written two or more PMAs to temporary files. It sets
+** up either VdbeSorter.pMerger (for single threaded sorters) or pReader
+** (for multi-threaded sorters) so that it can be used to iterate through
+** all records stored in the sorter.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
 */
-static int jrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsTruncate(p->pReal, size);
-  }else if( size<p->iSize ){
-    p->iSize = size;
+static int vdbeSorterSetupMerge(VdbeSorter *pSorter){
+  int rc;                         /* Return code */
+  SortSubtask *pTask0 = &pSorter->aTask[0];
+  MergeEngine *pMain = 0;
+#if SQLITE_MAX_WORKER_THREADS
+  sqlite3 *db = pTask0->pSorter->db;
+  int i;
+  SorterCompare xCompare = vdbeSorterGetCompare(pSorter);
+  for(i=0; i<pSorter->nTask; i++){
+    pSorter->aTask[i].xCompare = xCompare;
+  }
+#endif
+
+  rc = vdbeSorterMergeTreeBuild(pSorter, &pMain);
+  if( rc==SQLITE_OK ){
+#if SQLITE_MAX_WORKER_THREADS
+    assert( pSorter->bUseThreads==0 || pSorter->nTask>1 );
+    if( pSorter->bUseThreads ){
+      int iTask;
+      PmaReader *pReadr = 0;
+      SortSubtask *pLast = &pSorter->aTask[pSorter->nTask-1];
+      rc = vdbeSortAllocUnpacked(pLast);
+      if( rc==SQLITE_OK ){
+        pReadr = (PmaReader*)sqlite3DbMallocZero(db, sizeof(PmaReader));
+        pSorter->pReader = pReadr;
+        if( pReadr==0 ) rc = SQLITE_NOMEM_BKPT;
+      }
+      if( rc==SQLITE_OK ){
+        rc = vdbeIncrMergerNew(pLast, pMain, &pReadr->pIncr);
+        if( rc==SQLITE_OK ){
+          vdbeIncrMergerSetThreads(pReadr->pIncr);
+          for(iTask=0; iTask<(pSorter->nTask-1); iTask++){
+            IncrMerger *pIncr;
+            if( (pIncr = pMain->aReadr[iTask].pIncr) ){
+              vdbeIncrMergerSetThreads(pIncr);
+              assert( pIncr->pTask!=pLast );
+            }
+          }
+          for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){
+            /* Check that:
+            **   
+            **   a) The incremental merge object is configured to use the
+            **      right task, and
+            **   b) If it is using task (nTask-1), it is configured to run
+            **      in single-threaded mode. This is important, as the
+            **      root merge (INCRINIT_ROOT) will be using the same task
+            **      object.
+            */
+            PmaReader *p = &pMain->aReadr[iTask];
+            assert( p->pIncr==0 || (
+                (p->pIncr->pTask==&pSorter->aTask[iTask])             /* a */
+             && (iTask!=pSorter->nTask-1 || p->pIncr->bUseThread==0)  /* b */
+            ));
+            rc = vdbePmaReaderIncrInit(p, INCRINIT_TASK);
+          }
+        }
+        pMain = 0;
+      }
+      if( rc==SQLITE_OK ){
+        rc = vdbePmaReaderIncrMergeInit(pReadr, INCRINIT_ROOT);
+      }
+    }else
+#endif
+    {
+      rc = vdbeMergeEngineInit(pTask0, pMain, INCRINIT_NORMAL);
+      pSorter->pMerger = pMain;
+      pMain = 0;
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    vdbeMergeEngineFree(pMain);
   }
   return rc;
 }
 
+
 /*
-** Sync the file.
+** Once the sorter has been populated by calls to sqlite3VdbeSorterWrite,
+** this function is called to prepare for iterating through the records
+** in sorted order.
 */
-static int jrnlSync(sqlite3_file *pJfd, int flags){
-  int rc;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsSync(p->pReal, flags);
-  }else{
-    rc = SQLITE_OK;
+SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *pCsr, int *pbEof){
+  VdbeSorter *pSorter;
+  int rc = SQLITE_OK;             /* Return code */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  assert( pSorter );
+
+  /* If no data has been written to disk, then do not do so now. Instead,
+  ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly
+  ** from the in-memory list.  */
+  if( pSorter->bUsePMA==0 ){
+    if( pSorter->list.pList ){
+      *pbEof = 0;
+      rc = vdbeSorterSort(&pSorter->aTask[0], &pSorter->list);
+    }else{
+      *pbEof = 1;
+    }
+    return rc;
+  }
+
+  /* Write the current in-memory list to a PMA. When the VdbeSorterWrite() 
+  ** function flushes the contents of memory to disk, it immediately always
+  ** creates a new list consisting of a single key immediately afterwards.
+  ** So the list is never empty at this point.  */
+  assert( pSorter->list.pList );
+  rc = vdbeSorterFlushPMA(pSorter);
+
+  /* Join all threads */
+  rc = vdbeSorterJoinAll(pSorter, rc);
+
+  vdbeSorterRewindDebug("rewind");
+
+  /* Assuming no errors have occurred, set up a merger structure to 
+  ** incrementally read and merge all remaining PMAs.  */
+  assert( pSorter->pReader==0 );
+  if( rc==SQLITE_OK ){
+    rc = vdbeSorterSetupMerge(pSorter);
+    *pbEof = 0;
   }
+
+  vdbeSorterRewindDebug("rewinddone");
   return rc;
 }
 
 /*
-** Query the size of the file in bytes.
+** Advance to the next element in the sorter.
 */
-static int jrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){
-  int rc = SQLITE_OK;
-  JournalFile *p = (JournalFile *)pJfd;
-  if( p->pReal ){
-    rc = sqlite3OsFileSize(p->pReal, pSize);
+SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr, int *pbEof){
+  VdbeSorter *pSorter;
+  int rc;                         /* Return code */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  assert( pSorter->bUsePMA || (pSorter->pReader==0 && pSorter->pMerger==0) );
+  if( pSorter->bUsePMA ){
+    assert( pSorter->pReader==0 || pSorter->pMerger==0 );
+    assert( pSorter->bUseThreads==0 || pSorter->pReader );
+    assert( pSorter->bUseThreads==1 || pSorter->pMerger );
+#if SQLITE_MAX_WORKER_THREADS>0
+    if( pSorter->bUseThreads ){
+      rc = vdbePmaReaderNext(pSorter->pReader);
+      *pbEof = (pSorter->pReader->pFd==0);
+    }else
+#endif
+    /*if( !pSorter->bUseThreads )*/ {
+      assert( pSorter->pMerger!=0 );
+      assert( pSorter->pMerger->pTask==(&pSorter->aTask[0]) );
+      rc = vdbeMergeEngineStep(pSorter->pMerger, pbEof);
+    }
   }else{
-    *pSize = (sqlite_int64) p->iSize;
+    SorterRecord *pFree = pSorter->list.pList;
+    pSorter->list.pList = pFree->u.pNext;
+    pFree->u.pNext = 0;
+    if( pSorter->list.aMemory==0 ) vdbeSorterRecordFree(db, pFree);
+    *pbEof = !pSorter->list.pList;
+    rc = SQLITE_OK;
   }
   return rc;
 }
 
 /*
-** Table of methods for JournalFile sqlite3_file object.
-*/
-static struct sqlite3_io_methods JournalFileMethods = {
-  1,             /* iVersion */
-  jrnlClose,     /* xClose */
-  jrnlRead,      /* xRead */
-  jrnlWrite,     /* xWrite */
-  jrnlTruncate,  /* xTruncate */
-  jrnlSync,      /* xSync */
-  jrnlFileSize,  /* xFileSize */
-  0,             /* xLock */
-  0,             /* xUnlock */
-  0,             /* xCheckReservedLock */
-  0,             /* xFileControl */
-  0,             /* xSectorSize */
-  0,             /* xDeviceCharacteristics */
-  0,             /* xShmMap */
-  0,             /* xShmLock */
-  0,             /* xShmBarrier */
-  0              /* xShmUnmap */
-};
-
-/* 
-** Open a journal file.
+** Return a pointer to a buffer owned by the sorter that contains the 
+** current key.
 */
-SQLITE_PRIVATE int sqlite3JournalOpen(
-  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
-  const char *zName,         /* Name of the journal file */
-  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
-  int flags,                 /* Opening flags */
-  int nBuf                   /* Bytes buffered before opening the file */
+static void *vdbeSorterRowkey(
+  const VdbeSorter *pSorter,      /* Sorter object */
+  int *pnKey                      /* OUT: Size of current key in bytes */
 ){
-  JournalFile *p = (JournalFile *)pJfd;
-  memset(p, 0, sqlite3JournalSize(pVfs));
-  if( nBuf>0 ){
-    p->zBuf = sqlite3MallocZero(nBuf);
-    if( !p->zBuf ){
-      return SQLITE_NOMEM;
+  void *pKey;
+  if( pSorter->bUsePMA ){
+    PmaReader *pReader;
+#if SQLITE_MAX_WORKER_THREADS>0
+    if( pSorter->bUseThreads ){
+      pReader = pSorter->pReader;
+    }else
+#endif
+    /*if( !pSorter->bUseThreads )*/{
+      pReader = &pSorter->pMerger->aReadr[pSorter->pMerger->aTree[1]];
     }
+    *pnKey = pReader->nKey;
+    pKey = pReader->aKey;
   }else{
-    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
+    *pnKey = pSorter->list.pList->nVal;
+    pKey = SRVAL(pSorter->list.pList);
   }
-  p->pMethod = &JournalFileMethods;
-  p->nBuf = nBuf;
-  p->flags = flags;
-  p->zJournal = zName;
-  p->pVfs = pVfs;
-  return SQLITE_OK;
+  return pKey;
 }
 
 /*
-** If the argument p points to a JournalFile structure, and the underlying
-** file has not yet been created, create it now.
+** Copy the current sorter key into the memory cell pOut.
 */
-SQLITE_PRIVATE int sqlite3JournalCreate(sqlite3_file *p){
-  if( p->pMethods!=&JournalFileMethods ){
-    return SQLITE_OK;
+SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *pCsr, Mem *pOut){
+  VdbeSorter *pSorter;
+  void *pKey; int nKey;           /* Sorter key to copy into pOut */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  pKey = vdbeSorterRowkey(pSorter, &nKey);
+  if( sqlite3VdbeMemClearAndResize(pOut, nKey) ){
+    return SQLITE_NOMEM_BKPT;
   }
-  return createFile((JournalFile *)p);
+  pOut->n = nKey;
+  MemSetTypeFlag(pOut, MEM_Blob);
+  memcpy(pOut->z, pKey, nKey);
+
+  return SQLITE_OK;
 }
 
-/* 
-** Return the number of bytes required to store a JournalFile that uses vfs
-** pVfs to create the underlying on-disk files.
+/*
+** Compare the key in memory cell pVal with the key that the sorter cursor
+** passed as the first argument currently points to. For the purposes of
+** the comparison, ignore the rowid field at the end of each record.
+**
+** If the sorter cursor key contains any NULL values, consider it to be
+** less than pVal. Even if pVal also contains NULL values.
+**
+** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).
+** Otherwise, set *pRes to a negative, zero or positive value if the
+** key in pVal is smaller than, equal to or larger than the current sorter
+** key.
+**
+** This routine forms the core of the OP_SorterCompare opcode, which in
+** turn is used to verify uniqueness when constructing a UNIQUE INDEX.
 */
-SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
-  return (pVfs->szOsFile+sizeof(JournalFile));
+SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
+  const VdbeCursor *pCsr,         /* Sorter cursor */
+  Mem *pVal,                      /* Value to compare to current sorter key */
+  int nKeyCol,                    /* Compare this many columns */
+  int *pRes                       /* OUT: Result of comparison */
+){
+  VdbeSorter *pSorter;
+  UnpackedRecord *r2;
+  KeyInfo *pKeyInfo;
+  int i;
+  void *pKey; int nKey;           /* Sorter key to compare pVal with */
+
+  assert( pCsr->eCurType==CURTYPE_SORTER );
+  pSorter = pCsr->uc.pSorter;
+  r2 = pSorter->pUnpacked;
+  pKeyInfo = pCsr->pKeyInfo;
+  if( r2==0 ){
+    char *p;
+    r2 = pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pKeyInfo,0,0,&p);
+    assert( pSorter->pUnpacked==(UnpackedRecord*)p );
+    if( r2==0 ) return SQLITE_NOMEM_BKPT;
+    r2->nField = nKeyCol;
+  }
+  assert( r2->nField==nKeyCol );
+
+  pKey = vdbeSorterRowkey(pSorter, &nKey);
+  sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, r2);
+  for(i=0; i<nKeyCol; i++){
+    if( r2->aMem[i].flags & MEM_Null ){
+      *pRes = -1;
+      return SQLITE_OK;
+    }
+  }
+
+  *pRes = sqlite3VdbeRecordCompare(pVal->n, pVal->z, r2);
+  return SQLITE_OK;
 }
-#endif
 
-/************** End of journal.c *********************************************/
+/************** End of vdbesort.c ********************************************/
 /************** Begin file memjournal.c **************************************/
 /*
 ** 2008 October 7
@@ -71305,36 +87384,44 @@ SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
 ** This file contains code use to implement an in-memory rollback journal.
 ** The in-memory rollback journal is used to journal transactions for
 ** ":memory:" databases and when the journal_mode=MEMORY pragma is used.
+**
+** Update:  The in-memory journal is also used to temporarily cache
+** smaller journals that are not critical for power-loss recovery.
+** For example, statement journals that are not too big will be held
+** entirely in memory, thus reducing the number of file I/O calls, and
+** more importantly, reducing temporary file creation events.  If these
+** journals become too large for memory, they are spilled to disk.  But
+** in the common case, they are usually small and no file I/O needs to
+** occur.
 */
+/* #include "sqliteInt.h" */
 
 /* Forward references to internal structures */
 typedef struct MemJournal MemJournal;
 typedef struct FilePoint FilePoint;
 typedef struct FileChunk FileChunk;
 
-/* Space to hold the rollback journal is allocated in increments of
-** this many bytes.
+/*
+** The rollback journal is composed of a linked list of these structures.
 **
-** The size chosen is a little less than a power of two.  That way,
-** the FileChunk object will have a size that almost exactly fills
-** a power-of-two allocation.  This mimimizes wasted space in power-of-two
-** memory allocators.
+** The zChunk array is always at least 8 bytes in size - usually much more.
+** Its actual size is stored in the MemJournal.nChunkSize variable.
 */
-#define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))
+struct FileChunk {
+  FileChunk *pNext;               /* Next chunk in the journal */
+  u8 zChunk[8];                   /* Content of this chunk */
+};
 
-/* Macro to find the minimum of two numeric values.
+/*
+** By default, allocate this many bytes of memory for each FileChunk object.
 */
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
+#define MEMJOURNAL_DFLT_FILECHUNKSIZE 1024
 
 /*
-** The rollback journal is composed of a linked list of these structures.
+** For chunk size nChunkSize, return the number of bytes that should
+** be allocated for each FileChunk structure.
 */
-struct FileChunk {
-  FileChunk *pNext;               /* Next chunk in the journal */
-  u8 zChunk[JOURNAL_CHUNKSIZE];   /* Content of this chunk */
-};
+#define fileChunkSize(nChunkSize) (sizeof(FileChunk) + ((nChunkSize)-8))
 
 /*
 ** An instance of this object serves as a cursor into the rollback journal.
@@ -71346,14 +87433,22 @@ struct FilePoint {
 };
 
 /*
-** This subclass is a subclass of sqlite3_file.  Each open memory-journal
+** This structure is a subclass of sqlite3_file. Each open memory-journal
 ** is an instance of this class.
 */
 struct MemJournal {
-  sqlite3_io_methods *pMethod;    /* Parent class. MUST BE FIRST */
+  const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
+  int nChunkSize;                 /* In-memory chunk-size */
+
+  int nSpill;                     /* Bytes of data before flushing */
+  int nSize;                      /* Bytes of data currently in memory */
   FileChunk *pFirst;              /* Head of in-memory chunk-list */
   FilePoint endpoint;             /* Pointer to the end of the file */
   FilePoint readpoint;            /* Pointer to the end of the last xRead() */
+
+  int flags;                      /* xOpen flags */
+  sqlite3_vfs *pVfs;              /* The "real" underlying VFS */
+  const char *zJournal;           /* Name of the journal file */
 };
 
 /*
@@ -71372,37 +87467,95 @@ static int memjrnlRead(
   int iChunkOffset;
   FileChunk *pChunk;
 
-  /* SQLite never tries to read past the end of a rollback journal file */
-  assert( iOfst+iAmt<=p->endpoint.iOffset );
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+  if( (iAmt+iOfst)>p->endpoint.iOffset ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
+#endif
 
+  assert( (iAmt+iOfst)<=p->endpoint.iOffset );
+  assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 );
   if( p->readpoint.iOffset!=iOfst || iOfst==0 ){
     sqlite3_int64 iOff = 0;
     for(pChunk=p->pFirst; 
-        ALWAYS(pChunk) && (iOff+JOURNAL_CHUNKSIZE)<=iOfst;
+        ALWAYS(pChunk) && (iOff+p->nChunkSize)<=iOfst;
         pChunk=pChunk->pNext
     ){
-      iOff += JOURNAL_CHUNKSIZE;
+      iOff += p->nChunkSize;
     }
   }else{
     pChunk = p->readpoint.pChunk;
+    assert( pChunk!=0 );
   }
 
-  iChunkOffset = (int)(iOfst%JOURNAL_CHUNKSIZE);
+  iChunkOffset = (int)(iOfst%p->nChunkSize);
   do {
-    int iSpace = JOURNAL_CHUNKSIZE - iChunkOffset;
-    int nCopy = MIN(nRead, (JOURNAL_CHUNKSIZE - iChunkOffset));
-    memcpy(zOut, &pChunk->zChunk[iChunkOffset], nCopy);
+    int iSpace = p->nChunkSize - iChunkOffset;
+    int nCopy = MIN(nRead, (p->nChunkSize - iChunkOffset));
+    memcpy(zOut, (u8*)pChunk->zChunk + iChunkOffset, nCopy);
     zOut += nCopy;
     nRead -= iSpace;
     iChunkOffset = 0;
   } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 );
-  p->readpoint.iOffset = iOfst+iAmt;
+  p->readpoint.iOffset = pChunk ? iOfst+iAmt : 0;
   p->readpoint.pChunk = pChunk;
 
   return SQLITE_OK;
 }
 
 /*
+** Free the list of FileChunk structures headed at MemJournal.pFirst.
+*/
+static void memjrnlFreeChunks(MemJournal *p){
+  FileChunk *pIter;
+  FileChunk *pNext;
+  for(pIter=p->pFirst; pIter; pIter=pNext){
+    pNext = pIter->pNext;
+    sqlite3_free(pIter);
+  } 
+  p->pFirst = 0;
+}
+
+/*
+** Flush the contents of memory to a real file on disk.
+*/
+static int memjrnlCreateFile(MemJournal *p){
+  int rc;
+  sqlite3_file *pReal = (sqlite3_file*)p;
+  MemJournal copy = *p;
+
+  memset(p, 0, sizeof(MemJournal));
+  rc = sqlite3OsOpen(copy.pVfs, copy.zJournal, pReal, copy.flags, 0);
+  if( rc==SQLITE_OK ){
+    int nChunk = copy.nChunkSize;
+    i64 iOff = 0;
+    FileChunk *pIter;
+    for(pIter=copy.pFirst; pIter; pIter=pIter->pNext){
+      if( iOff + nChunk > copy.endpoint.iOffset ){
+        nChunk = copy.endpoint.iOffset - iOff;
+      }
+      rc = sqlite3OsWrite(pReal, (u8*)pIter->zChunk, nChunk, iOff);
+      if( rc ) break;
+      iOff += nChunk;
+    }
+    if( rc==SQLITE_OK ){
+      /* No error has occurred. Free the in-memory buffers. */
+      memjrnlFreeChunks(&copy);
+    }
+  }
+  if( rc!=SQLITE_OK ){
+    /* If an error occurred while creating or writing to the file, restore
+    ** the original before returning. This way, SQLite uses the in-memory
+    ** journal data to roll back changes made to the internal page-cache
+    ** before this function was called.  */
+    sqlite3OsClose(pReal);
+    *p = copy;
+  }
+  return rc;
+}
+
+
+/*
 ** Write data to the file.
 */
 static int memjrnlWrite(
@@ -71415,38 +87568,62 @@ static int memjrnlWrite(
   int nWrite = iAmt;
   u8 *zWrite = (u8 *)zBuf;
 
-  /* An in-memory journal file should only ever be appended to. Random
-  ** access writes are not required by sqlite.
-  */
-  assert( iOfst==p->endpoint.iOffset );
-  UNUSED_PARAMETER(iOfst);
+  /* If the file should be created now, create it and write the new data
+  ** into the file on disk. */
+  if( p->nSpill>0 && (iAmt+iOfst)>p->nSpill ){
+    int rc = memjrnlCreateFile(p);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3OsWrite(pJfd, zBuf, iAmt, iOfst);
+    }
+    return rc;
+  }
 
-  while( nWrite>0 ){
-    FileChunk *pChunk = p->endpoint.pChunk;
-    int iChunkOffset = (int)(p->endpoint.iOffset%JOURNAL_CHUNKSIZE);
-    int iSpace = MIN(nWrite, JOURNAL_CHUNKSIZE - iChunkOffset);
+  /* If the contents of this write should be stored in memory */
+  else{
+    /* An in-memory journal file should only ever be appended to. Random
+    ** access writes are not required. The only exception to this is when
+    ** the in-memory journal is being used by a connection using the
+    ** atomic-write optimization. In this case the first 28 bytes of the
+    ** journal file may be written as part of committing the transaction. */ 
+    assert( iOfst==p->endpoint.iOffset || iOfst==0 );
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+    if( iOfst==0 && p->pFirst ){
+      assert( p->nChunkSize>iAmt );
+      memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt);
+    }else
+#else
+    assert( iOfst>0 || p->pFirst==0 );
+#endif
+    {
+      while( nWrite>0 ){
+        FileChunk *pChunk = p->endpoint.pChunk;
+        int iChunkOffset = (int)(p->endpoint.iOffset%p->nChunkSize);
+        int iSpace = MIN(nWrite, p->nChunkSize - iChunkOffset);
+
+        if( iChunkOffset==0 ){
+          /* New chunk is required to extend the file. */
+          FileChunk *pNew = sqlite3_malloc(fileChunkSize(p->nChunkSize));
+          if( !pNew ){
+            return SQLITE_IOERR_NOMEM_BKPT;
+          }
+          pNew->pNext = 0;
+          if( pChunk ){
+            assert( p->pFirst );
+            pChunk->pNext = pNew;
+          }else{
+            assert( !p->pFirst );
+            p->pFirst = pNew;
+          }
+          p->endpoint.pChunk = pNew;
+        }
 
-    if( iChunkOffset==0 ){
-      /* New chunk is required to extend the file. */
-      FileChunk *pNew = sqlite3_malloc(sizeof(FileChunk));
-      if( !pNew ){
-        return SQLITE_IOERR_NOMEM;
+        memcpy((u8*)p->endpoint.pChunk->zChunk + iChunkOffset, zWrite, iSpace);
+        zWrite += iSpace;
+        nWrite -= iSpace;
+        p->endpoint.iOffset += iSpace;
       }
-      pNew->pNext = 0;
-      if( pChunk ){
-        assert( p->pFirst );
-        pChunk->pNext = pNew;
-      }else{
-        assert( !p->pFirst );
-        p->pFirst = pNew;
-      }
-      p->endpoint.pChunk = pNew;
+      p->nSize = iAmt + iOfst;
     }
-
-    memcpy(&p->endpoint.pChunk->zChunk[iChunkOffset], zWrite, iSpace);
-    zWrite += iSpace;
-    nWrite -= iSpace;
-    p->endpoint.iOffset += iSpace;
   }
 
   return SQLITE_OK;
@@ -71454,19 +87631,21 @@ static int memjrnlWrite(
 
 /*
 ** Truncate the file.
+**
+** If the journal file is already on disk, truncate it there. Or, if it
+** is still in main memory but is being truncated to zero bytes in size,
+** ignore 
 */
 static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
   MemJournal *p = (MemJournal *)pJfd;
-  FileChunk *pChunk;
-  assert(size==0);
-  UNUSED_PARAMETER(size);
-  pChunk = p->pFirst;
-  while( pChunk ){
-    FileChunk *pTmp = pChunk;
-    pChunk = pChunk->pNext;
-    sqlite3_free(pTmp);
-  }
-  sqlite3MemJournalOpen(pJfd);
+  if( ALWAYS(size==0) ){
+    memjrnlFreeChunks(p);
+    p->nSize = 0;
+    p->endpoint.pChunk = 0;
+    p->endpoint.iOffset = 0;
+    p->readpoint.pChunk = 0;
+    p->readpoint.iOffset = 0;
+  }
   return SQLITE_OK;
 }
 
@@ -71474,21 +87653,19 @@ static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
 ** Close the file.
 */
 static int memjrnlClose(sqlite3_file *pJfd){
-  memjrnlTruncate(pJfd, 0);
+  MemJournal *p = (MemJournal *)pJfd;
+  memjrnlFreeChunks(p);
   return SQLITE_OK;
 }
 
-
 /*
 ** Sync the file.
 **
-** Syncing an in-memory journal is a no-op.  And, in fact, this routine
-** is never called in a working implementation.  This implementation
-** exists purely as a contingency, in case some malfunction in some other
-** part of SQLite causes Sync to be called by mistake.
+** If the real file has been created, call its xSync method. Otherwise, 
+** syncing an in-memory journal is a no-op. 
 */
-static int memjrnlSync(sqlite3_file *NotUsed, int NotUsed2){
-  UNUSED_PARAMETER2(NotUsed, NotUsed2);
+static int memjrnlSync(sqlite3_file *pJfd, int flags){
+  UNUSED_PARAMETER2(pJfd, flags);
   return SQLITE_OK;
 }
 
@@ -71521,32 +87698,94 @@ static const struct sqlite3_io_methods MemJournalMethods = {
   0,                /* xShmMap */
   0,                /* xShmLock */
   0,                /* xShmBarrier */
-  0                 /* xShmUnlock */
+  0,                /* xShmUnmap */
+  0,                /* xFetch */
+  0                 /* xUnfetch */
 };
 
 /* 
-** Open a journal file.
+** Open a journal file. 
+**
+** The behaviour of the journal file depends on the value of parameter 
+** nSpill. If nSpill is 0, then the journal file is always create and 
+** accessed using the underlying VFS. If nSpill is less than zero, then
+** all content is always stored in main-memory. Finally, if nSpill is a
+** positive value, then the journal file is initially created in-memory
+** but may be flushed to disk later on. In this case the journal file is
+** flushed to disk either when it grows larger than nSpill bytes in size,
+** or when sqlite3JournalCreate() is called.
+*/
+SQLITE_PRIVATE int sqlite3JournalOpen(
+  sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */
+  const char *zName,         /* Name of the journal file */
+  sqlite3_file *pJfd,        /* Preallocated, blank file handle */
+  int flags,                 /* Opening flags */
+  int nSpill                 /* Bytes buffered before opening the file */
+){
+  MemJournal *p = (MemJournal*)pJfd;
+
+  /* Zero the file-handle object. If nSpill was passed zero, initialize
+  ** it using the sqlite3OsOpen() function of the underlying VFS. In this
+  ** case none of the code in this module is executed as a result of calls
+  ** made on the journal file-handle.  */
+  memset(p, 0, sizeof(MemJournal));
+  if( nSpill==0 ){
+    return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);
+  }
+
+  if( nSpill>0 ){
+    p->nChunkSize = nSpill;
+  }else{
+    p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk);
+    assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );
+  }
+
+  p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;
+  p->nSpill = nSpill;
+  p->flags = flags;
+  p->zJournal = zName;
+  p->pVfs = pVfs;
+  return SQLITE_OK;
+}
+
+/*
+** Open an in-memory journal file.
 */
 SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *pJfd){
-  MemJournal *p = (MemJournal *)pJfd;
-  assert( EIGHT_BYTE_ALIGNMENT(p) );
-  memset(p, 0, sqlite3MemJournalSize());
-  p->pMethod = (sqlite3_io_methods*)&MemJournalMethods;
+  sqlite3JournalOpen(0, 0, pJfd, 0, -1);
 }
 
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
 /*
-** Return true if the file-handle passed as an argument is 
-** an in-memory journal 
+** If the argument p points to a MemJournal structure that is not an 
+** in-memory-only journal file (i.e. is one that was opened with a +ve
+** nSpill parameter), and the underlying file has not yet been created, 
+** create it now.
 */
-SQLITE_PRIVATE int sqlite3IsMemJournal(sqlite3_file *pJfd){
-  return pJfd->pMethods==&MemJournalMethods;
+SQLITE_PRIVATE int sqlite3JournalCreate(sqlite3_file *p){
+  int rc = SQLITE_OK;
+  if( p->pMethods==&MemJournalMethods && ((MemJournal*)p)->nSpill>0 ){
+    rc = memjrnlCreateFile((MemJournal*)p);
+  }
+  return rc;
+}
+#endif
+
+/*
+** The file-handle passed as the only argument is open on a journal file.
+** Return true if this "journal file" is currently stored in heap memory,
+** or false otherwise.
+*/
+SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p){
+  return p->pMethods==&MemJournalMethods;
 }
 
 /* 
-** Return the number of bytes required to store a MemJournal file descriptor.
+** Return the number of bytes required to store a JournalFile that uses vfs
+** pVfs to create the underlying on-disk files.
 */
-SQLITE_PRIVATE int sqlite3MemJournalSize(void){
-  return sizeof(MemJournal);
+SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){
+  return MAX(pVfs->szOsFile, (int)sizeof(MemJournal));
 }
 
 /************** End of memjournal.c ******************************************/
@@ -71565,13 +87804,14 @@ SQLITE_PRIVATE int sqlite3MemJournalSize(void){
 ** This file contains routines used for walking the parser tree for
 ** an SQL statement.
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 /* #include <string.h> */
 
 
 /*
 ** Walk an expression tree.  Invoke the callback once for each node
-** of the expression, while decending.  (In other words, the callback
+** of the expression, while descending.  (In other words, the callback
 ** is invoked before visiting children.)
 **
 ** The return value from the callback should be one of the WRC_*
@@ -71588,14 +87828,13 @@ SQLITE_PRIVATE int sqlite3MemJournalSize(void){
 ** The return value from this routine is WRC_Abort to abandon the tree walk
 ** and WRC_Continue to continue.
 */
-SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){
   int rc;
-  if( pExpr==0 ) return WRC_Continue;
   testcase( ExprHasProperty(pExpr, EP_TokenOnly) );
   testcase( ExprHasProperty(pExpr, EP_Reduced) );
   rc = pWalker->xExprCallback(pWalker, pExpr);
   if( rc==WRC_Continue
-              && !ExprHasAnyProperty(pExpr,EP_TokenOnly) ){
+              && !ExprHasProperty(pExpr,EP_TokenOnly) ){
     if( sqlite3WalkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
     if( sqlite3WalkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
@@ -71606,6 +87845,9 @@ SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
   }
   return rc & WRC_Abort;
 }
+SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+  return pExpr ? walkExpr(pWalker,pExpr) : WRC_Continue;
+}
 
 /*
 ** Call sqlite3WalkExpr() for every expression in list p or until
@@ -71657,6 +87899,11 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
       if( sqlite3WalkSelect(pWalker, pItem->pSelect) ){
         return WRC_Abort;
       }
+      if( pItem->fg.isTabFunc
+       && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)
+      ){
+        return WRC_Abort;
+      }
     }
   }
   return WRC_Continue;
@@ -71665,7 +87912,12 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
 /*
 ** Call sqlite3WalkExpr() for every expression in Select statement p.
 ** Invoke sqlite3WalkSelect() for subqueries in the FROM clause and
-** on the compound select chain, p->pPrior.
+** on the compound select chain, p->pPrior. 
+**
+** If it is not NULL, the xSelectCallback() callback is invoked before
+** the walk of the expressions and FROM clause. The xSelectCallback2()
+** method, if it is not NULL, is invoked following the walk of the 
+** expressions and FROM clause.
 **
 ** Return WRC_Continue under normal conditions.  Return WRC_Abort if
 ** there is an abort request.
@@ -71675,15 +87927,28 @@ SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
 */
 SQLITE_PRIVATE int sqlite3WalkSelect(Walker *pWalker, Select *p){
   int rc;
-  if( p==0 || pWalker->xSelectCallback==0 ) return WRC_Continue;
+  if( p==0 || (pWalker->xSelectCallback==0 && pWalker->xSelectCallback2==0) ){
+    return WRC_Continue;
+  }
   rc = WRC_Continue;
-  while( p  ){
-    rc = pWalker->xSelectCallback(pWalker, p);
-    if( rc ) break;
-    if( sqlite3WalkSelectExpr(pWalker, p) ) return WRC_Abort;
-    if( sqlite3WalkSelectFrom(pWalker, p) ) return WRC_Abort;
+  pWalker->walkerDepth++;
+  while( p ){
+    if( pWalker->xSelectCallback ){
+       rc = pWalker->xSelectCallback(pWalker, p);
+       if( rc ) break;
+    }
+    if( sqlite3WalkSelectExpr(pWalker, p)
+     || sqlite3WalkSelectFrom(pWalker, p)
+    ){
+      pWalker->walkerDepth--;
+      return WRC_Abort;
+    }
+    if( pWalker->xSelectCallback2 ){
+      pWalker->xSelectCallback2(pWalker, p);
+    }
     p = p->pPrior;
   }
+  pWalker->walkerDepth--;
   return rc & WRC_Abort;
 }
 
@@ -71705,42 +87970,59 @@ SQLITE_PRIVATE int sqlite3WalkSelect(Walker *pWalker, Select *p){
 ** resolve all identifiers by associating them with a particular
 ** table and column.
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 /* #include <string.h> */
 
 /*
+** Walk the expression tree pExpr and increase the aggregate function
+** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node.
+** This needs to occur when copying a TK_AGG_FUNCTION node from an
+** outer query into an inner subquery.
+**
+** incrAggFunctionDepth(pExpr,n) is the main routine.  incrAggDepth(..)
+** is a helper function - a callback for the tree walker.
+*/
+static int incrAggDepth(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n;
+  return WRC_Continue;
+}
+static void incrAggFunctionDepth(Expr *pExpr, int N){
+  if( N>0 ){
+    Walker w;
+    memset(&w, 0, sizeof(w));
+    w.xExprCallback = incrAggDepth;
+    w.u.n = N;
+    sqlite3WalkExpr(&w, pExpr);
+  }
+}
+
+/*
 ** Turn the pExpr expression into an alias for the iCol-th column of the
 ** result set in pEList.
 **
-** If the result set column is a simple column reference, then this routine
-** makes an exact copy.  But for any other kind of expression, this
-** routine make a copy of the result set column as the argument to the
-** TK_AS operator.  The TK_AS operator causes the expression to be
-** evaluated just once and then reused for each alias.
-**
-** The reason for suppressing the TK_AS term when the expression is a simple
-** column reference is so that the column reference will be recognized as
-** usable by indices within the WHERE clause processing logic. 
-**
-** Hack:  The TK_AS operator is inhibited if zType[0]=='G'.  This means
-** that in a GROUP BY clause, the expression is evaluated twice.  Hence:
+** If the reference is followed by a COLLATE operator, then make sure
+** the COLLATE operator is preserved.  For example:
 **
-**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
+**     SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;
 **
-** Is equivalent to:
+** Should be transformed into:
 **
-**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
+**     SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;
 **
-** The result of random()%5 in the GROUP BY clause is probably different
-** from the result in the result-set.  We might fix this someday.  Or
-** then again, we might not...
+** The nSubquery parameter specifies how many levels of subquery the
+** alias is removed from the original expression.  The usual value is
+** zero but it might be more if the alias is contained within a subquery
+** of the original expression.  The Expr.op2 field of TK_AGG_FUNCTION
+** structures must be increased by the nSubquery amount.
 */
 static void resolveAlias(
   Parse *pParse,         /* Parsing context */
   ExprList *pEList,      /* A result set */
   int iCol,              /* A column in the result set.  0..pEList->nExpr-1 */
   Expr *pExpr,           /* Transform this into an alias to the result set */
-  const char *zType      /* "GROUP" or "ORDER" or "" */
+  const char *zType,     /* "GROUP" or "ORDER" or "" */
+  int nSubquery          /* Number of subqueries that the label is moving */
 ){
   Expr *pOrig;           /* The iCol-th column of the result set */
   Expr *pDup;            /* Copy of pOrig */
@@ -71749,42 +88031,30 @@ static void resolveAlias(
   assert( iCol>=0 && iCol<pEList->nExpr );
   pOrig = pEList->a[iCol].pExpr;
   assert( pOrig!=0 );
-  assert( pOrig->flags & EP_Resolved );
   db = pParse->db;
-  if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
-    pDup = sqlite3ExprDup(db, pOrig, 0);
-    pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
-    if( pDup==0 ) return;
-    if( pEList->a[iCol].iAlias==0 ){
-      pEList->a[iCol].iAlias = (u16)(++pParse->nAlias);
-    }
-    pDup->iTable = pEList->a[iCol].iAlias;
-  }else if( ExprHasProperty(pOrig, EP_IntValue) || pOrig->u.zToken==0 ){
-    pDup = sqlite3ExprDup(db, pOrig, 0);
-    if( pDup==0 ) return;
-  }else{
-    char *zToken = pOrig->u.zToken;
-    assert( zToken!=0 );
-    pOrig->u.zToken = 0;
-    pDup = sqlite3ExprDup(db, pOrig, 0);
-    pOrig->u.zToken = zToken;
-    if( pDup==0 ) return;
-    assert( (pDup->flags & (EP_Reduced|EP_TokenOnly))==0 );
-    pDup->flags2 |= EP2_MallocedToken;
-    pDup->u.zToken = sqlite3DbStrDup(db, zToken);
-  }
-  if( pExpr->flags & EP_ExpCollate ){
-    pDup->pColl = pExpr->pColl;
-    pDup->flags |= EP_ExpCollate;
+  pDup = sqlite3ExprDup(db, pOrig, 0);
+  if( pDup==0 ) return;
+  if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery);
+  if( pExpr->op==TK_COLLATE ){
+    pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
   }
+  ExprSetProperty(pDup, EP_Alias);
 
   /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
   ** prevents ExprDelete() from deleting the Expr structure itself,
   ** allowing it to be repopulated by the memcpy() on the following line.
+  ** The pExpr->u.zToken might point into memory that will be freed by the
+  ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to
+  ** make a copy of the token before doing the sqlite3DbFree().
   */
   ExprSetProperty(pExpr, EP_Static);
   sqlite3ExprDelete(db, pExpr);
   memcpy(pExpr, pDup, sizeof(*pExpr));
+  if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){
+    assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 );
+    pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken);
+    pExpr->flags |= EP_MemToken;
+  }
   sqlite3DbFree(db, pDup);
 }
 
@@ -71805,6 +88075,35 @@ static int nameInUsingClause(IdList *pUsing, const char *zCol){
   return 0;
 }
 
+/*
+** Subqueries stores the original database, table and column names for their
+** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN".
+** Check to see if the zSpan given to this routine matches the zDb, zTab,
+** and zCol.  If any of zDb, zTab, and zCol are NULL then those fields will
+** match anything.
+*/
+SQLITE_PRIVATE int sqlite3MatchSpanName(
+  const char *zSpan,
+  const char *zCol,
+  const char *zTab,
+  const char *zDb
+){
+  int n;
+  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+  if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){
+    return 0;
+  }
+  zSpan += n+1;
+  for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}
+  if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){
+    return 0;
+  }
+  zSpan += n+1;
+  if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){
+    return 0;
+  }
+  return 1;
+}
 
 /*
 ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
@@ -71841,24 +88140,51 @@ static int lookupName(
   NameContext *pNC,    /* The name context used to resolve the name */
   Expr *pExpr          /* Make this EXPR node point to the selected column */
 ){
-  int i, j;            /* Loop counters */
+  int i, j;                         /* Loop counters */
   int cnt = 0;                      /* Number of matching column names */
   int cntTab = 0;                   /* Number of matching table names */
+  int nSubquery = 0;                /* How many levels of subquery */
   sqlite3 *db = pParse->db;         /* The database connection */
   struct SrcList_item *pItem;       /* Use for looping over pSrcList items */
   struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */
   NameContext *pTopNC = pNC;        /* First namecontext in the list */
   Schema *pSchema = 0;              /* Schema of the expression */
-  int isTrigger = 0;
+  int isTrigger = 0;                /* True if resolved to a trigger column */
+  Table *pTab = 0;                  /* Table hold the row */
+  Column *pCol;                     /* A column of pTab */
 
   assert( pNC );     /* the name context cannot be NULL. */
   assert( zCol );    /* The Z in X.Y.Z cannot be NULL */
-  assert( ~ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
+  assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
 
   /* Initialize the node to no-match */
   pExpr->iTable = -1;
   pExpr->pTab = 0;
-  ExprSetIrreducible(pExpr);
+  ExprSetVVAProperty(pExpr, EP_NoReduce);
+
+  /* Translate the schema name in zDb into a pointer to the corresponding
+  ** schema.  If not found, pSchema will remain NULL and nothing will match
+  ** resulting in an appropriate error message toward the end of this routine
+  */
+  if( zDb ){
+    testcase( pNC->ncFlags & NC_PartIdx );
+    testcase( pNC->ncFlags & NC_IsCheck );
+    if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
+      /* Silently ignore database qualifiers inside CHECK constraints and
+      ** partial indices.  Do not raise errors because that might break
+      ** legacy and because it does not hurt anything to just ignore the
+      ** database name. */
+      zDb = 0;
+    }else{
+      for(i=0; i<db->nDb; i++){
+        assert( db->aDb[i].zName );
+        if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+          pSchema = db->aDb[i].pSchema;
+          break;
+        }
+      }
+    }
+  }
 
   /* Start at the inner-most context and move outward until a match is found */
   while( pNC && cnt==0 ){
@@ -71867,32 +88193,34 @@ static int lookupName(
 
     if( pSrcList ){
       for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
-        Table *pTab;
-        int iDb;
-        Column *pCol;
-  
         pTab = pItem->pTab;
         assert( pTab!=0 && pTab->zName!=0 );
-        iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
         assert( pTab->nCol>0 );
-        if( zTab ){
-          if( pItem->zAlias ){
-            char *zTabName = pItem->zAlias;
-            if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
-          }else{
-            char *zTabName = pTab->zName;
-            if( NEVER(zTabName==0) || sqlite3StrICmp(zTabName, zTab)!=0 ){
-              continue;
-            }
-            if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
-              continue;
+        if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){
+          int hit = 0;
+          pEList = pItem->pSelect->pEList;
+          for(j=0; j<pEList->nExpr; j++){
+            if( sqlite3MatchSpanName(pEList->a[j].zSpan, zCol, zTab, zDb) ){
+              cnt++;
+              cntTab = 2;
+              pMatch = pItem;
+              pExpr->iColumn = j;
+              hit = 1;
             }
           }
+          if( hit || zTab==0 ) continue;
+        }
+        if( zDb && pTab->pSchema!=pSchema ){
+          continue;
+        }
+        if( zTab ){
+          const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName;
+          assert( zTabName!=0 );
+          if( sqlite3StrICmp(zTabName, zTab)!=0 ){
+            continue;
+          }
         }
         if( 0==(cntTab++) ){
-          pExpr->iTable = pItem->iCursor;
-          pExpr->pTab = pTab;
-          pSchema = pTab->pSchema;
           pMatch = pItem;
         }
         for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
@@ -71902,29 +88230,35 @@ static int lookupName(
             ** USING clause, then skip this match.
             */
             if( cnt==1 ){
-              if( pItem->jointype & JT_NATURAL ) continue;
+              if( pItem->fg.jointype & JT_NATURAL ) continue;
               if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
             }
             cnt++;
-            pExpr->iTable = pItem->iCursor;
-            pExpr->pTab = pTab;
             pMatch = pItem;
-            pSchema = pTab->pSchema;
             /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
             pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
             break;
           }
         }
       }
-    }
+      if( pMatch ){
+        pExpr->iTable = pMatch->iCursor;
+        pExpr->pTab = pMatch->pTab;
+        /* RIGHT JOIN not (yet) supported */
+        assert( (pMatch->fg.jointype & JT_RIGHT)==0 );
+        if( (pMatch->fg.jointype & JT_LEFT)!=0 ){
+          ExprSetProperty(pExpr, EP_CanBeNull);
+        }
+        pSchema = pExpr->pTab->pSchema;
+      }
+    } /* if( pSrcList ) */
 
 #ifndef SQLITE_OMIT_TRIGGER
     /* If we have not already resolved the name, then maybe 
     ** it is a new.* or old.* trigger argument reference
     */
-    if( zDb==0 && zTab!=0 && cnt==0 && pParse->pTriggerTab!=0 ){
+    if( zDb==0 && zTab!=0 && cntTab==0 && pParse->pTriggerTab!=0 ){
       int op = pParse->eTriggerOp;
-      Table *pTab = 0;
       assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
       if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){
         pExpr->iTable = 1;
@@ -71932,14 +88266,15 @@ static int lookupName(
       }else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){
         pExpr->iTable = 0;
         pTab = pParse->pTriggerTab;
+      }else{
+        pTab = 0;
       }
 
       if( pTab ){ 
         int iCol;
         pSchema = pTab->pSchema;
         cntTab++;
-        for(iCol=0; iCol<pTab->nCol; iCol++){
-          Column *pCol = &pTab->aCol[iCol];
+        for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){
           if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
             if( iCol==pTab->iPKey ){
               iCol = -1;
@@ -71947,8 +88282,9 @@ static int lookupName(
             break;
           }
         }
-        if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) ){
-          iCol = -1;        /* IMP: R-44911-55124 */
+        if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){
+          /* IMP: R-51414-32910 */
+          iCol = -1;
         }
         if( iCol<pTab->nCol ){
           cnt++;
@@ -71974,9 +88310,15 @@ static int lookupName(
     /*
     ** Perhaps the name is a reference to the ROWID
     */
-    if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
+    if( cnt==0
+     && cntTab==1
+     && pMatch
+     && (pNC->ncFlags & NC_IdxExpr)==0
+     && sqlite3IsRowid(zCol)
+     && VisibleRowid(pMatch->pTab)
+    ){
       cnt = 1;
-      pExpr->iColumn = -1;     /* IMP: R-44911-55124 */
+      pExpr->iColumn = -1;
       pExpr->affinity = SQLITE_AFF_INTEGER;
     }
 
@@ -71991,8 +88333,17 @@ static int lookupName(
     ** forms the result set entry ("a+b" in the example) and return immediately.
     ** Note that the expression in the result set should have already been
     ** resolved by the time the WHERE clause is resolved.
+    **
+    ** The ability to use an output result-set column in the WHERE, GROUP BY,
+    ** or HAVING clauses, or as part of a larger expression in the ORDER BY
+    ** clause is not standard SQL.  This is a (goofy) SQLite extension, that
+    ** is supported for backwards compatibility only. Hence, we issue a warning
+    ** on sqlite3_log() whenever the capability is used.
     */
-    if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
+    if( (pEList = pNC->pEList)!=0
+     && zTab==0
+     && cnt==0
+    ){
       for(j=0; j<pEList->nExpr; j++){
         char *zAs = pEList->a[j].zName;
         if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
@@ -72001,11 +88352,11 @@ static int lookupName(
           assert( pExpr->x.pList==0 );
           assert( pExpr->x.pSelect==0 );
           pOrig = pEList->a[j].pExpr;
-          if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
+          if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){
             sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
             return WRC_Abort;
           }
-          resolveAlias(pParse, pEList, j, pExpr, "");
+          resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);
           cnt = 1;
           pMatch = 0;
           assert( zTab==0 && zDb==0 );
@@ -72019,6 +88370,7 @@ static int lookupName(
     */
     if( cnt==0 ){
       pNC = pNC->pNext;
+      nSubquery++;
     }
   }
 
@@ -72082,7 +88434,9 @@ static int lookupName(
 lookupname_end:
   if( cnt==1 ){
     assert( pNC!=0 );
-    sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+    if( !ExprHasProperty(pExpr, EP_Alias) ){
+      sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+    }
     /* Increment the nRef value on all name contexts from TopNC up to
     ** the point where the name matched. */
     for(;;){
@@ -72121,6 +88475,41 @@ SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSr
 }
 
 /*
+** Report an error that an expression is not valid for some set of
+** pNC->ncFlags values determined by validMask.
+*/
+static void notValid(
+  Parse *pParse,       /* Leave error message here */
+  NameContext *pNC,    /* The name context */
+  const char *zMsg,    /* Type of error */
+  int validMask        /* Set of contexts for which prohibited */
+){
+  assert( (validMask&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr))==0 );
+  if( (pNC->ncFlags & validMask)!=0 ){
+    const char *zIn = "partial index WHERE clauses";
+    if( pNC->ncFlags & NC_IdxExpr )      zIn = "index expressions";
+#ifndef SQLITE_OMIT_CHECK
+    else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints";
+#endif
+    sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn);
+  }
+}
+
+/*
+** Expression p should encode a floating point value between 1.0 and 0.0.
+** Return 1024 times this value.  Or return -1 if p is not a floating point
+** value between 1.0 and 0.0.
+*/
+static int exprProbability(Expr *p){
+  double r = -1.0;
+  if( p->op!=TK_FLOAT ) return -1;
+  sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
+  assert( r>=0.0 );
+  if( r>1.0 ) return -1;
+  return (int)(r*134217728.0);
+}
+
+/*
 ** This routine is callback for sqlite3WalkExpr().
 **
 ** Resolve symbolic names into TK_COLUMN operators for the current
@@ -72140,7 +88529,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
   pParse = pNC->pParse;
   assert( pParse==pWalker->pParse );
 
-  if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return WRC_Prune;
+  if( ExprHasProperty(pExpr, EP_Resolved) ) return WRC_Prune;
   ExprSetProperty(pExpr, EP_Resolved);
 #ifndef NDEBUG
   if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
@@ -72170,7 +88559,8 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       pExpr->affinity = SQLITE_AFF_INTEGER;
       break;
     }
-#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
+#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
+          && !defined(SQLITE_OMIT_SUBQUERY) */
 
     /* A lone identifier is the name of a column.
     */
@@ -72188,6 +88578,8 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       Expr *pRight;
 
       /* if( pSrcList==0 ) break; */
+      notValid(pParse, pNC, "the \".\" operator", NC_IdxExpr);
+      /*notValid(pParse, pNC, "the \".\" operator", NC_PartIdx|NC_IsCheck, 1);*/
       pRight = pExpr->pRight;
       if( pRight->op==TK_ID ){
         zDb = 0;
@@ -72204,7 +88596,6 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
 
     /* Resolve function names
     */
-    case TK_CONST_FUNC:
     case TK_FUNCTION: {
       ExprList *pList = pExpr->x.pList;    /* The argument list */
       int n = pList ? pList->nExpr : 0;    /* Number of arguments */
@@ -72217,23 +88608,44 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       FuncDef *pDef;              /* Information about the function */
       u8 enc = ENC(pParse->db);   /* The database encoding */
 
-      testcase( pExpr->op==TK_CONST_FUNC );
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+      notValid(pParse, pNC, "functions", NC_PartIdx);
       zId = pExpr->u.zToken;
       nId = sqlite3Strlen30(zId);
-      pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
+      pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0);
       if( pDef==0 ){
-        pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
+        pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0);
         if( pDef==0 ){
           no_such_func = 1;
         }else{
           wrong_num_args = 1;
         }
       }else{
-        is_agg = pDef->xFunc==0;
-      }
+        is_agg = pDef->xFinalize!=0;
+        if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
+          ExprSetProperty(pExpr, EP_Unlikely|EP_Skip);
+          if( n==2 ){
+            pExpr->iTable = exprProbability(pList->a[1].pExpr);
+            if( pExpr->iTable<0 ){
+              sqlite3ErrorMsg(pParse,
+                "second argument to likelihood() must be a "
+                "constant between 0.0 and 1.0");
+              pNC->nErr++;
+            }
+          }else{
+            /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is
+            ** equivalent to likelihood(X, 0.0625).
+            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is
+            ** short-hand for likelihood(X,0.0625).
+            ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand
+            ** for likelihood(X,0.9375).
+            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent
+            ** to likelihood(X,0.9375). */
+            /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */
+            pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120;
+          }             
+        }
 #ifndef SQLITE_OMIT_AUTHORIZATION
-      if( pDef ){
         auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
         if( auth!=SQLITE_OK ){
           if( auth==SQLITE_DENY ){
@@ -72244,13 +88656,29 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
           pExpr->op = TK_NULL;
           return WRC_Prune;
         }
-      }
 #endif
-      if( is_agg && !pNC->allowAgg ){
+        if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){
+          /* For the purposes of the EP_ConstFunc flag, date and time
+          ** functions and other functions that change slowly are considered
+          ** constant because they are constant for the duration of one query */
+          ExprSetProperty(pExpr,EP_ConstFunc);
+        }
+        if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){
+          /* Date/time functions that use 'now', and other functions like
+          ** sqlite_version() that might change over time cannot be used
+          ** in an index. */
+          notValid(pParse, pNC, "non-deterministic functions", NC_IdxExpr);
+        }
+      }
+      if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
         pNC->nErr++;
         is_agg = 0;
-      }else if( no_such_func ){
+      }else if( no_such_func && pParse->db->init.busy==0
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+                && pParse->explain==0
+#endif
+      ){
         sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
         pNC->nErr++;
       }else if( wrong_num_args ){
@@ -72258,13 +88686,25 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
              nId, zId);
         pNC->nErr++;
       }
+      if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg;
+      sqlite3WalkExprList(pWalker, pList);
       if( is_agg ){
+        NameContext *pNC2 = pNC;
         pExpr->op = TK_AGG_FUNCTION;
-        pNC->hasAgg = 1;
+        pExpr->op2 = 0;
+        while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
+          pExpr->op2++;
+          pNC2 = pNC2->pNext;
+        }
+        assert( pDef!=0 );
+        if( pNC2 ){
+          assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
+          testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
+          pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);
+
+        }
+        pNC->ncFlags |= NC_AllowAgg;
       }
-      if( is_agg ) pNC->allowAgg = 0;
-      sqlite3WalkExprList(pWalker, pList);
-      if( is_agg ) pNC->allowAgg = 1;
       /* FIX ME:  Compute pExpr->affinity based on the expected return
       ** type of the function 
       */
@@ -72278,27 +88718,20 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_IN );
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         int nRef = pNC->nRef;
-#ifndef SQLITE_OMIT_CHECK
-        if( pNC->isCheck ){
-          sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
-        }
-#endif
+        notValid(pParse, pNC, "subqueries", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
         sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
         assert( pNC->nRef>=nRef );
         if( nRef!=pNC->nRef ){
           ExprSetProperty(pExpr, EP_VarSelect);
+          pNC->ncFlags |= NC_VarSelect;
         }
       }
       break;
     }
-#ifndef SQLITE_OMIT_CHECK
     case TK_VARIABLE: {
-      if( pNC->isCheck ){
-        sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
-      }
+      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
       break;
     }
-#endif
   }
   return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
 }
@@ -72375,7 +88808,7 @@ static int resolveOrderByTermToExprList(
   nc.pParse = pParse;
   nc.pSrcList = pSelect->pSrc;
   nc.pEList = pEList;
-  nc.allowAgg = 1;
+  nc.ncFlags = NC_AllowAgg;
   nc.nErr = 0;
   db = pParse->db;
   savedSuppErr = db->suppressErr;
@@ -72389,7 +88822,7 @@ static int resolveOrderByTermToExprList(
   ** result-set entry.
   */
   for(i=0; i<pEList->nExpr; i++){
-    if( sqlite3ExprCompare(pEList->a[i].pExpr, pE)<2 ){
+    if( sqlite3ExprCompare(pEList->a[i].pExpr, pE, -1)<2 ){
       return i+1;
     }
   }
@@ -72463,7 +88896,7 @@ static int resolveCompoundOrderBy(
       int iCol = -1;
       Expr *pE, *pDup;
       if( pItem->done ) continue;
-      pE = pItem->pExpr;
+      pE = sqlite3ExprSkipCollate(pItem->pExpr);
       if( sqlite3ExprIsInteger(pE, &iCol) ){
         if( iCol<=0 || iCol>pEList->nExpr ){
           resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
@@ -72481,15 +88914,23 @@ static int resolveCompoundOrderBy(
         }
       }
       if( iCol>0 ){
-        CollSeq *pColl = pE->pColl;
-        int flags = pE->flags & EP_ExpCollate;
+        /* Convert the ORDER BY term into an integer column number iCol,
+        ** taking care to preserve the COLLATE clause if it exists */
+        Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
+        if( pNew==0 ) return 1;
+        pNew->flags |= EP_IntValue;
+        pNew->u.iValue = iCol;
+        if( pItem->pExpr==pE ){
+          pItem->pExpr = pNew;
+        }else{
+          Expr *pParent = pItem->pExpr;
+          assert( pParent->op==TK_COLLATE );
+          while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft;
+          assert( pParent->pLeft==pE );
+          pParent->pLeft = pNew;
+        }
         sqlite3ExprDelete(db, pE);
-        pItem->pExpr = pE = sqlite3Expr(db, TK_INTEGER, 0);
-        if( pE==0 ) return 1;
-        pE->pColl = pColl;
-        pE->flags |= EP_IntValue | flags;
-        pE->u.iValue = iCol;
-        pItem->iCol = (u16)iCol;
+        pItem->u.x.iOrderByCol = (u16)iCol;
         pItem->done = 1;
       }else{
         moreToDo = 1;
@@ -72510,8 +88951,8 @@ static int resolveCompoundOrderBy(
 /*
 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of
 ** the SELECT statement pSelect.  If any term is reference to a
-** result set expression (as determined by the ExprList.a.iCol field)
-** then convert that term into a copy of the corresponding result set
+** result set expression (as determined by the ExprList.a.u.x.iOrderByCol
+** field) then convert that term into a copy of the corresponding result set
 ** column.
 **
 ** If any errors are detected, add an error message to pParse and
@@ -72538,12 +88979,13 @@ SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(
   pEList = pSelect->pEList;
   assert( pEList!=0 );  /* sqlite3SelectNew() guarantees this */
   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
-    if( pItem->iCol ){
-      if( pItem->iCol>pEList->nExpr ){
+    if( pItem->u.x.iOrderByCol ){
+      if( pItem->u.x.iOrderByCol>pEList->nExpr ){
         resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
         return 1;
       }
-      resolveAlias(pParse, pEList, pItem->iCol-1, pItem->pExpr, zType);
+      resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,
+                   zType,0);
     }
   }
   return 0;
@@ -72558,7 +89000,7 @@ SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(
 ** If the order-by term is an integer I between 1 and N (where N is the
 ** number of columns in the result set of the SELECT) then the expression
 ** in the resolution is a copy of the I-th result-set expression.  If
-** the order-by term is an identify that corresponds to the AS-name of
+** the order-by term is an identifier that corresponds to the AS-name of
 ** a result-set expression, then the term resolves to a copy of the
 ** result-set expression.  Otherwise, the expression is resolved in
 ** the usual way - using sqlite3ResolveExprNames().
@@ -72573,7 +89015,7 @@ static int resolveOrderGroupBy(
   ExprList *pOrderBy,   /* An ORDER BY or GROUP BY clause to resolve */
   const char *zType     /* Either "ORDER" or "GROUP", as appropriate */
 ){
-  int i;                         /* Loop counter */
+  int i, j;                      /* Loop counters */
   int iCol;                      /* Column number */
   struct ExprList_item *pItem;   /* A term of the ORDER BY clause */
   Parse *pParse;                 /* Parsing context */
@@ -72584,38 +89026,46 @@ static int resolveOrderGroupBy(
   pParse = pNC->pParse;
   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
     Expr *pE = pItem->pExpr;
-    iCol = resolveAsName(pParse, pSelect->pEList, pE);
-    if( iCol>0 ){
-      /* If an AS-name match is found, mark this ORDER BY column as being
-      ** a copy of the iCol-th result-set column.  The subsequent call to
-      ** sqlite3ResolveOrderGroupBy() will convert the expression to a
-      ** copy of the iCol-th result-set expression. */
-      pItem->iCol = (u16)iCol;
-      continue;
+    Expr *pE2 = sqlite3ExprSkipCollate(pE);
+    if( zType[0]!='G' ){
+      iCol = resolveAsName(pParse, pSelect->pEList, pE2);
+      if( iCol>0 ){
+        /* If an AS-name match is found, mark this ORDER BY column as being
+        ** a copy of the iCol-th result-set column.  The subsequent call to
+        ** sqlite3ResolveOrderGroupBy() will convert the expression to a
+        ** copy of the iCol-th result-set expression. */
+        pItem->u.x.iOrderByCol = (u16)iCol;
+        continue;
+      }
     }
-    if( sqlite3ExprIsInteger(pE, &iCol) ){
+    if( sqlite3ExprIsInteger(pE2, &iCol) ){
       /* The ORDER BY term is an integer constant.  Again, set the column
       ** number so that sqlite3ResolveOrderGroupBy() will convert the
       ** order-by term to a copy of the result-set expression */
-      if( iCol<1 ){
+      if( iCol<1 || iCol>0xffff ){
         resolveOutOfRangeError(pParse, zType, i+1, nResult);
         return 1;
       }
-      pItem->iCol = (u16)iCol;
+      pItem->u.x.iOrderByCol = (u16)iCol;
       continue;
     }
 
     /* Otherwise, treat the ORDER BY term as an ordinary expression */
-    pItem->iCol = 0;
+    pItem->u.x.iOrderByCol = 0;
     if( sqlite3ResolveExprNames(pNC, pE) ){
       return 1;
     }
+    for(j=0; j<pSelect->pEList->nExpr; j++){
+      if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
+        pItem->u.x.iOrderByCol = j+1;
+      }
+    }
   }
   return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);
 }
 
 /*
-** Resolve names in the SELECT statement p and all of its descendents.
+** Resolve names in the SELECT statement p and all of its descendants.
 */
 static int resolveSelectStep(Walker *pWalker, Select *p){
   NameContext *pOuterNC;  /* Context that contains this SELECT */
@@ -72623,7 +89073,6 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
   int isCompound;         /* True if p is a compound select */
   int nCompound;          /* Number of compound terms processed so far */
   Parse *pParse;          /* Parsing context */
-  ExprList *pEList;       /* Result set expression list */
   int i;                  /* Loop counter */
   ExprList *pGroupBy;     /* The GROUP BY clause */
   Select *pLeftmost;      /* Left-most of SELECT of a compound */
@@ -72668,22 +89117,19 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         sqlite3ResolveExprNames(&sNC, p->pOffset) ){
       return WRC_Abort;
     }
-  
-    /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
-    ** resolve the result-set expression list.
-    */
-    sNC.allowAgg = 1;
-    sNC.pSrcList = p->pSrc;
-    sNC.pNext = pOuterNC;
-  
-    /* Resolve names in the result set. */
-    pEList = p->pEList;
-    assert( pEList!=0 );
-    for(i=0; i<pEList->nExpr; i++){
-      Expr *pX = pEList->a[i].pExpr;
-      if( sqlite3ResolveExprNames(&sNC, pX) ){
-        return WRC_Abort;
-      }
+
+    /* If the SF_Converted flags is set, then this Select object was
+    ** was created by the convertCompoundSelectToSubquery() function.
+    ** In this case the ORDER BY clause (p->pOrderBy) should be resolved
+    ** as if it were part of the sub-query, not the parent. This block
+    ** moves the pOrderBy down to the sub-query. It will be moved back
+    ** after the names have been resolved.  */
+    if( p->selFlags & SF_Converted ){
+      Select *pSub = p->pSrc->a[0].pSelect;
+      assert( p->pSrc->nSrc==1 && p->pOrderBy );
+      assert( pSub->pPrior && pSub->pOrderBy==0 );
+      pSub->pOrderBy = p->pOrderBy;
+      p->pOrderBy = 0;
     }
   
     /* Recursively resolve names in all subqueries
@@ -72699,7 +89145,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         ** parent contexts. After resolving references to expressions in
         ** pItem->pSelect, check if this value has changed. If so, then
         ** SELECT statement pItem->pSelect must be correlated. Set the
-        ** pItem->isCorrelated flag if this is the case. */
+        ** pItem->fg.isCorrelated flag if this is the case. */
         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;
 
         if( pItem->zName ) pParse->zAuthContext = pItem->zName;
@@ -72708,20 +89154,31 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
         if( pParse->nErr || db->mallocFailed ) return WRC_Abort;
 
         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
-        assert( pItem->isCorrelated==0 && nRef<=0 );
-        pItem->isCorrelated = (nRef!=0);
+        assert( pItem->fg.isCorrelated==0 && nRef<=0 );
+        pItem->fg.isCorrelated = (nRef!=0);
       }
     }
   
+    /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
+    ** resolve the result-set expression list.
+    */
+    sNC.ncFlags = NC_AllowAgg;
+    sNC.pSrcList = p->pSrc;
+    sNC.pNext = pOuterNC;
+  
+    /* Resolve names in the result set. */
+    if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort;
+  
     /* If there are no aggregate functions in the result-set, and no GROUP BY 
     ** expression, do not allow aggregates in any of the other expressions.
     */
     assert( (p->selFlags & SF_Aggregate)==0 );
     pGroupBy = p->pGroupBy;
-    if( pGroupBy || sNC.hasAgg ){
-      p->selFlags |= SF_Aggregate;
+    if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
+      assert( NC_MinMaxAgg==SF_MinMaxAgg );
+      p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);
     }else{
-      sNC.allowAgg = 0;
+      sNC.ncFlags &= ~NC_AllowAgg;
     }
   
     /* If a HAVING clause is present, then there must be a GROUP BY clause.
@@ -72731,7 +89188,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       return WRC_Abort;
     }
   
-    /* Add the expression list to the name-context before parsing the
+    /* Add the output column list to the name-context before parsing the
     ** other expressions in the SELECT statement. This is so that
     ** expressions in the WHERE clause (etc.) can refer to expressions by
     ** aliases in the result set.
@@ -72740,24 +89197,49 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     ** re-evaluated for each reference to it.
     */
     sNC.pEList = p->pEList;
-    if( sqlite3ResolveExprNames(&sNC, p->pWhere) ||
-       sqlite3ResolveExprNames(&sNC, p->pHaving)
-    ){
-      return WRC_Abort;
+    if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
+    if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
+
+    /* Resolve names in table-valued-function arguments */
+    for(i=0; i<p->pSrc->nSrc; i++){
+      struct SrcList_item *pItem = &p->pSrc->a[i];
+      if( pItem->fg.isTabFunc
+       && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 
+      ){
+        return WRC_Abort;
+      }
     }
 
     /* The ORDER BY and GROUP BY clauses may not refer to terms in
     ** outer queries 
     */
     sNC.pNext = 0;
-    sNC.allowAgg = 1;
+    sNC.ncFlags |= NC_AllowAgg;
+
+    /* If this is a converted compound query, move the ORDER BY clause from 
+    ** the sub-query back to the parent query. At this point each term
+    ** within the ORDER BY clause has been transformed to an integer value.
+    ** These integers will be replaced by copies of the corresponding result
+    ** set expressions by the call to resolveOrderGroupBy() below.  */
+    if( p->selFlags & SF_Converted ){
+      Select *pSub = p->pSrc->a[0].pSelect;
+      p->pOrderBy = pSub->pOrderBy;
+      pSub->pOrderBy = 0;
+    }
 
     /* Process the ORDER BY clause for singleton SELECT statements.
     ** The ORDER BY clause for compounds SELECT statements is handled
     ** below, after all of the result-sets for all of the elements of
     ** the compound have been resolved.
+    **
+    ** If there is an ORDER BY clause on a term of a compound-select other
+    ** than the right-most term, then that is a syntax error.  But the error
+    ** is not detected until much later, and so we need to go ahead and
+    ** resolve those symbols on the incorrect ORDER BY for consistency.
     */
-    if( !isCompound && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER") ){
+    if( isCompound<=nCompound  /* Defer right-most ORDER BY of a compound */
+     && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER")
+    ){
       return WRC_Abort;
     }
     if( db->mallocFailed ){
@@ -72782,6 +89264,13 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       }
     }
 
+    /* If this is part of a compound SELECT, check that it has the right
+    ** number of expressions in the select list. */
+    if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){
+      sqlite3SelectWrongNumTermsError(pParse, p->pNext);
+      return WRC_Abort;
+    }
+
     /* Advance to the next term of the compound
     */
     p = p->pPrior;
@@ -72838,7 +89327,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
 **
 ** Function calls are checked to make sure that the function is 
 ** defined and that the correct number of arguments are specified.
-** If the function is an aggregate function, then the pNC->hasAgg is
+** If the function is an aggregate function, then the NC_HasAgg flag is
 ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION.
 ** If an expression contains aggregate functions then the EP_Agg
 ** property on the expression is set.
@@ -72850,7 +89339,7 @@ SQLITE_PRIVATE int sqlite3ResolveExprNames(
   NameContext *pNC,       /* Namespace to resolve expressions in. */
   Expr *pExpr             /* The expression to be analyzed. */
 ){
-  int savedHasAgg;
+  u16 savedHasAgg;
   Walker w;
 
   if( pExpr==0 ) return 0;
@@ -72863,11 +89352,14 @@ SQLITE_PRIVATE int sqlite3ResolveExprNames(
     pParse->nHeight += pExpr->nHeight;
   }
 #endif
-  savedHasAgg = pNC->hasAgg;
-  pNC->hasAgg = 0;
+  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
+  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
+  w.pParse = pNC->pParse;
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
-  w.pParse = pNC->pParse;
+  w.xSelectCallback2 = 0;
+  w.walkerDepth = 0;
+  w.eCode = 0;
   w.u.pNC = pNC;
   sqlite3WalkExpr(&w, pExpr);
 #if SQLITE_MAX_EXPR_DEPTH>0
@@ -72876,14 +89368,30 @@ SQLITE_PRIVATE int sqlite3ResolveExprNames(
   if( pNC->nErr>0 || w.pParse->nErr>0 ){
     ExprSetProperty(pExpr, EP_Error);
   }
-  if( pNC->hasAgg ){
+  if( pNC->ncFlags & NC_HasAgg ){
     ExprSetProperty(pExpr, EP_Agg);
-  }else if( savedHasAgg ){
-    pNC->hasAgg = 1;
   }
+  pNC->ncFlags |= savedHasAgg;
   return ExprHasProperty(pExpr, EP_Error);
 }
 
+/*
+** Resolve all names for all expression in an expression list.  This is
+** just like sqlite3ResolveExprNames() except that it works for an expression
+** list rather than a single expression.
+*/
+SQLITE_PRIVATE int sqlite3ResolveExprListNames( 
+  NameContext *pNC,       /* Namespace to resolve expressions in. */
+  ExprList *pList         /* The expression list to be analyzed. */
+){
+  int i;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+      if( sqlite3ResolveExprNames(pNC, pList->a[i].pExpr) ) return WRC_Abort;
+    }
+  }
+  return WRC_Continue;
+}
 
 /*
 ** Resolve all names in all expressions of a SELECT and in all
@@ -72905,6 +89413,7 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
   Walker w;
 
   assert( p!=0 );
+  memset(&w, 0, sizeof(w));
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
   w.pParse = pParse;
@@ -72912,6 +89421,41 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
   sqlite3WalkSelect(&w, p);
 }
 
+/*
+** Resolve names in expressions that can only reference a single table:
+**
+**    *   CHECK constraints
+**    *   WHERE clauses on partial indices
+**
+** The Expr.iTable value for Expr.op==TK_COLUMN nodes of the expression
+** is set to -1 and the Expr.iColumn value is set to the column number.
+**
+** Any errors cause an error message to be set in pParse.
+*/
+SQLITE_PRIVATE void sqlite3ResolveSelfReference(
+  Parse *pParse,      /* Parsing context */
+  Table *pTab,        /* The table being referenced */
+  int type,           /* NC_IsCheck or NC_PartIdx or NC_IdxExpr */
+  Expr *pExpr,        /* Expression to resolve.  May be NULL. */
+  ExprList *pList     /* Expression list to resolve.  May be NUL. */
+){
+  SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
+  NameContext sNC;                /* Name context for pParse->pNewTable */
+
+  assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr );
+  memset(&sNC, 0, sizeof(sNC));
+  memset(&sSrc, 0, sizeof(sSrc));
+  sSrc.nSrc = 1;
+  sSrc.a[0].zName = pTab->zName;
+  sSrc.a[0].pTab = pTab;
+  sSrc.a[0].iCursor = -1;
+  sNC.pParse = pParse;
+  sNC.pSrcList = &sSrc;
+  sNC.ncFlags = type;
+  if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
+  if( pList ) sqlite3ResolveExprListNames(&sNC, pList);
+}
+
 /************** End of resolve.c *********************************************/
 /************** Begin file expr.c ********************************************/
 /*
@@ -72928,6 +89472,7 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Return the 'affinity' of the expression pExpr if any.
@@ -72937,7 +89482,7 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
 ** affinity of that column is returned. Otherwise, 0x00 is returned,
 ** indicating no affinity for the expression.
 **
-** i.e. the WHERE clause expresssions in the following statements all
+** i.e. the WHERE clause expressions in the following statements all
 ** have an affinity:
 **
 ** CREATE TABLE t1(a);
@@ -72946,7 +89491,10 @@ SQLITE_PRIVATE void sqlite3ResolveSelectNames(
 ** SELECT * FROM t1 WHERE (select a from t1);
 */
 SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){
-  int op = pExpr->op;
+  int op;
+  pExpr = sqlite3ExprSkipCollate(pExpr);
+  if( pExpr->flags & EP_Generic ) return 0;
+  op = pExpr->op;
   if( op==TK_SELECT ){
     assert( pExpr->flags&EP_xIsSelect );
     return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
@@ -72954,7 +89502,7 @@ SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){
 #ifndef SQLITE_OMIT_CAST
   if( op==TK_CAST ){
     assert( !ExprHasProperty(pExpr, EP_IntValue) );
-    return sqlite3AffinityType(pExpr->u.zToken);
+    return sqlite3AffinityType(pExpr->u.zToken, 0);
   }
 #endif
   if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER) 
@@ -72971,66 +89519,116 @@ SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){
 }
 
 /*
-** Set the explicit collating sequence for an expression to the
-** collating sequence supplied in the second argument.
+** Set the collating sequence for expression pExpr to be the collating
+** sequence named by pToken.   Return a pointer to a new Expr node that
+** implements the COLLATE operator.
+**
+** If a memory allocation error occurs, that fact is recorded in pParse->db
+** and the pExpr parameter is returned unchanged.
 */
-SQLITE_PRIVATE Expr *sqlite3ExprSetColl(Expr *pExpr, CollSeq *pColl){
-  if( pExpr && pColl ){
-    pExpr->pColl = pColl;
-    pExpr->flags |= EP_ExpCollate;
+SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(
+  Parse *pParse,           /* Parsing context */
+  Expr *pExpr,             /* Add the "COLLATE" clause to this expression */
+  const Token *pCollName,  /* Name of collating sequence */
+  int dequote              /* True to dequote pCollName */
+){
+  if( pCollName->n>0 ){
+    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);
+    if( pNew ){
+      pNew->pLeft = pExpr;
+      pNew->flags |= EP_Collate|EP_Skip;
+      pExpr = pNew;
+    }
   }
   return pExpr;
 }
+SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
+  Token s;
+  assert( zC!=0 );
+  sqlite3TokenInit(&s, (char*)zC);
+  return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);
+}
 
 /*
-** Set the collating sequence for expression pExpr to be the collating
-** sequence named by pToken.   Return a pointer to the revised expression.
-** The collating sequence is marked as "explicit" using the EP_ExpCollate
-** flag.  An explicit collating sequence will override implicit
-** collating sequences.
+** Skip over any TK_COLLATE operators and any unlikely()
+** or likelihood() function at the root of an expression.
 */
-SQLITE_PRIVATE Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr *pExpr, Token *pCollName){
-  char *zColl = 0;            /* Dequoted name of collation sequence */
-  CollSeq *pColl;
-  sqlite3 *db = pParse->db;
-  zColl = sqlite3NameFromToken(db, pCollName);
-  pColl = sqlite3LocateCollSeq(pParse, zColl);
-  sqlite3ExprSetColl(pExpr, pColl);
-  sqlite3DbFree(db, zColl);
+SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr *pExpr){
+  while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
+    if( ExprHasProperty(pExpr, EP_Unlikely) ){
+      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+      assert( pExpr->x.pList->nExpr>0 );
+      assert( pExpr->op==TK_FUNCTION );
+      pExpr = pExpr->x.pList->a[0].pExpr;
+    }else{
+      assert( pExpr->op==TK_COLLATE );
+      pExpr = pExpr->pLeft;
+    }
+  }   
   return pExpr;
 }
 
 /*
-** Return the default collation sequence for the expression pExpr. If
-** there is no default collation type, return 0.
+** Return the collation sequence for the expression pExpr. If
+** there is no defined collating sequence, return NULL.
+**
+** The collating sequence might be determined by a COLLATE operator
+** or by the presence of a column with a defined collating sequence.
+** COLLATE operators take first precedence.  Left operands take
+** precedence over right operands.
 */
 SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
+  sqlite3 *db = pParse->db;
   CollSeq *pColl = 0;
   Expr *p = pExpr;
   while( p ){
-    int op;
-    pColl = p->pColl;
-    if( pColl ) break;
-    op = p->op;
-    if( p->pTab!=0 && (
-        op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER
-    )){
+    int op = p->op;
+    if( p->flags & EP_Generic ) break;
+    if( op==TK_CAST || op==TK_UPLUS ){
+      p = p->pLeft;
+      continue;
+    }
+    if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
+      pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
+      break;
+    }
+    if( (op==TK_AGG_COLUMN || op==TK_COLUMN
+          || op==TK_REGISTER || op==TK_TRIGGER)
+     && p->pTab!=0
+    ){
       /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
       ** a TK_COLUMN but was previously evaluated and cached in a register */
-      const char *zColl;
       int j = p->iColumn;
       if( j>=0 ){
-        sqlite3 *db = pParse->db;
-        zColl = p->pTab->aCol[j].zColl;
+        const char *zColl = p->pTab->aCol[j].zColl;
         pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
-        pExpr->pColl = pColl;
       }
       break;
     }
-    if( op!=TK_CAST && op!=TK_UPLUS ){
+    if( p->flags & EP_Collate ){
+      if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
+        p = p->pLeft;
+      }else{
+        Expr *pNext  = p->pRight;
+        /* The Expr.x union is never used at the same time as Expr.pRight */
+        assert( p->x.pList==0 || p->pRight==0 );
+        /* p->flags holds EP_Collate and p->pLeft->flags does not.  And
+        ** p->x.pSelect cannot.  So if p->x.pLeft exists, it must hold at
+        ** least one EP_Collate. Thus the following two ALWAYS. */
+        if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){
+          int i;
+          for(i=0; ALWAYS(i<p->x.pList->nExpr); i++){
+            if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
+              pNext = p->x.pList->a[i].pExpr;
+              break;
+            }
+          }
+        }
+        p = pNext;
+      }
+    }else{
       break;
     }
-    p = p->pLeft;
   }
   if( sqlite3CheckCollSeq(pParse, pColl) ){ 
     pColl = 0;
@@ -73052,13 +89650,13 @@ SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2){
     if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
       return SQLITE_AFF_NUMERIC;
     }else{
-      return SQLITE_AFF_NONE;
+      return SQLITE_AFF_BLOB;
     }
   }else if( !aff1 && !aff2 ){
     /* Neither side of the comparison is a column.  Compare the
     ** results directly.
     */
-    return SQLITE_AFF_NONE;
+    return SQLITE_AFF_BLOB;
   }else{
     /* One side is a column, the other is not. Use the columns affinity. */
     assert( aff1==0 || aff2==0 );
@@ -73082,7 +89680,7 @@ static char comparisonAffinity(Expr *pExpr){
   }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
     aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
   }else if( !aff ){
-    aff = SQLITE_AFF_NONE;
+    aff = SQLITE_AFF_BLOB;
   }
   return aff;
 }
@@ -73096,7 +89694,7 @@ static char comparisonAffinity(Expr *pExpr){
 SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
   char aff = comparisonAffinity(pExpr);
   switch( aff ){
-    case SQLITE_AFF_NONE:
+    case SQLITE_AFF_BLOB:
       return 1;
     case SQLITE_AFF_TEXT:
       return idx_affinity==SQLITE_AFF_TEXT;
@@ -73134,12 +89732,10 @@ SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(
 ){
   CollSeq *pColl;
   assert( pLeft );
-  if( pLeft->flags & EP_ExpCollate ){
-    assert( pLeft->pColl );
-    pColl = pLeft->pColl;
-  }else if( pRight && pRight->flags & EP_ExpCollate ){
-    assert( pRight->pColl );
-    pColl = pRight->pColl;
+  if( pLeft->flags & EP_Collate ){
+    pColl = sqlite3ExprCollSeq(pParse, pLeft);
+  }else if( pRight && (pRight->flags & EP_Collate)!=0 ){
+    pColl = sqlite3ExprCollSeq(pParse, pRight);
   }else{
     pColl = sqlite3ExprCollSeq(pParse, pLeft);
     if( !pColl ){
@@ -73234,6 +89830,9 @@ static void heightOfSelect(Select *p, int *pnHeight){
 ** Expr.pSelect member has a height of 1. Any other expression
 ** has a height equal to the maximum height of any other 
 ** referenced Expr plus one.
+**
+** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
+** if appropriate.
 */
 static void exprSetHeight(Expr *p){
   int nHeight = 0;
@@ -73241,8 +89840,9 @@ static void exprSetHeight(Expr *p){
   heightOfExpr(p->pRight, &nHeight);
   if( ExprHasProperty(p, EP_xIsSelect) ){
     heightOfSelect(p->x.pSelect, &nHeight);
-  }else{
+  }else if( p->x.pList ){
     heightOfExprList(p->x.pList, &nHeight);
+    p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
   }
   p->nHeight = nHeight + 1;
 }
@@ -73251,8 +89851,12 @@ static void exprSetHeight(Expr *p){
 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
 ** the height is greater than the maximum allowed expression depth,
 ** leave an error in pParse.
+**
+** Also propagate all EP_Propagate flags from the Expr.x.pList into
+** Expr.flags. 
 */
-SQLITE_PRIVATE void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
+  if( pParse->nErr ) return;
   exprSetHeight(p);
   sqlite3ExprCheckHeight(pParse, p->nHeight);
 }
@@ -73266,8 +89870,17 @@ SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){
   heightOfSelect(p, &nHeight);
   return nHeight;
 }
-#else
-  #define exprSetHeight(y)
+#else /* ABOVE:  Height enforcement enabled.  BELOW: Height enforcement off */
+/*
+** Propagate all EP_Propagate flags from the Expr.x.pList into
+** Expr.flags. 
+*/
+SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
+  if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
+    p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
+  }
+}
+#define exprSetHeight(y)
 #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
 
 /*
@@ -73279,7 +89892,7 @@ SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){
 ** is responsible for making sure the node eventually gets freed.
 **
 ** If dequote is true, then the token (if it exists) is dequoted.
-** If dequote is false, no dequoting is performance.  The deQuote
+** If dequote is false, no dequoting is performed.  The deQuote
 ** parameter is ignored if pToken is NULL or if the token does not
 ** appear to be quoted.  If the quotes were of the form "..." (double-quotes)
 ** then the EP_DblQuoted flag is set on the expression node.
@@ -73300,6 +89913,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
   int nExtra = 0;
   int iValue = 0;
 
+  assert( db!=0 );
   if( pToken ){
     if( op!=TK_INTEGER || pToken->z==0
           || sqlite3GetInt32(pToken->z, &iValue)==0 ){
@@ -73307,8 +89921,9 @@ SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
       assert( iValue>=0 );
     }
   }
-  pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
+  pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);
   if( pNew ){
+    memset(pNew, 0, sizeof(Expr));
     pNew->op = (u8)op;
     pNew->iAgg = -1;
     if( pToken ){
@@ -73316,15 +89931,13 @@ SQLITE_PRIVATE Expr *sqlite3ExprAlloc(
         pNew->flags |= EP_IntValue;
         pNew->u.iValue = iValue;
       }else{
-        int c;
         pNew->u.zToken = (char*)&pNew[1];
         assert( pToken->z!=0 || pToken->n==0 );
         if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
         pNew->u.zToken[pToken->n] = 0;
-        if( dequote && nExtra>=3 
-             && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){
+        if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){
+          if( pNew->u.zToken[0]=='"' ) pNew->flags |= EP_DblQuoted;
           sqlite3Dequote(pNew->u.zToken);
-          if( c=='"' ) pNew->flags |= EP_DblQuoted;
         }
       }
     }
@@ -73369,24 +89982,18 @@ SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(
   }else{
     if( pRight ){
       pRoot->pRight = pRight;
-      if( pRight->flags & EP_ExpCollate ){
-        pRoot->flags |= EP_ExpCollate;
-        pRoot->pColl = pRight->pColl;
-      }
+      pRoot->flags |= EP_Propagate & pRight->flags;
     }
     if( pLeft ){
       pRoot->pLeft = pLeft;
-      if( pLeft->flags & EP_ExpCollate ){
-        pRoot->flags |= EP_ExpCollate;
-        pRoot->pColl = pLeft->pColl;
-      }
+      pRoot->flags |= EP_Propagate & pLeft->flags;
     }
     exprSetHeight(pRoot);
   }
 }
 
 /*
-** Allocate a Expr node which joins as many as two subtrees.
+** Allocate an Expr node which joins as many as two subtrees.
 **
 ** One or both of the subtrees can be NULL.  Return a pointer to the new
 ** Expr node.  Or, if an OOM error occurs, set pParse->db->mallocFailed,
@@ -73399,8 +90006,14 @@ SQLITE_PRIVATE Expr *sqlite3PExpr(
   Expr *pRight,           /* Right operand */
   const Token *pToken     /* Argument token */
 ){
-  Expr *p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
-  sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
+  Expr *p;
+  if( op==TK_AND && pParse->nErr==0 ){
+    /* Take advantage of short-circuit false optimization for AND */
+    p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
+  }else{
+    p = sqlite3ExprAlloc(pParse->db, op & TKFLG_MASK, pToken, 1);
+    sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
+  }
   if( p ) {
     sqlite3ExprCheckHeight(pParse, p->nHeight);
   }
@@ -73408,14 +90021,65 @@ SQLITE_PRIVATE Expr *sqlite3PExpr(
 }
 
 /*
+** Add pSelect to the Expr.x.pSelect field.  Or, if pExpr is NULL (due
+** do a memory allocation failure) then delete the pSelect object.
+*/
+SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){
+  if( pExpr ){
+    pExpr->x.pSelect = pSelect;
+    ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);
+    sqlite3ExprSetHeightAndFlags(pParse, pExpr);
+  }else{
+    assert( pParse->db->mallocFailed );
+    sqlite3SelectDelete(pParse->db, pSelect);
+  }
+}
+
+
+/*
+** If the expression is always either TRUE or FALSE (respectively),
+** then return 1.  If one cannot determine the truth value of the
+** expression at compile-time return 0.
+**
+** This is an optimization.  If is OK to return 0 here even if
+** the expression really is always false or false (a false negative).
+** But it is a bug to return 1 if the expression might have different
+** boolean values in different circumstances (a false positive.)
+**
+** Note that if the expression is part of conditional for a
+** LEFT JOIN, then we cannot determine at compile-time whether or not
+** is it true or false, so always return 0.
+*/
+static int exprAlwaysTrue(Expr *p){
+  int v = 0;
+  if( ExprHasProperty(p, EP_FromJoin) ) return 0;
+  if( !sqlite3ExprIsInteger(p, &v) ) return 0;
+  return v!=0;
+}
+static int exprAlwaysFalse(Expr *p){
+  int v = 0;
+  if( ExprHasProperty(p, EP_FromJoin) ) return 0;
+  if( !sqlite3ExprIsInteger(p, &v) ) return 0;
+  return v==0;
+}
+
+/*
 ** Join two expressions using an AND operator.  If either expression is
 ** NULL, then just return the other expression.
+**
+** If one side or the other of the AND is known to be false, then instead
+** of returning an AND expression, just return a constant expression with
+** a value of false.
 */
 SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
   if( pLeft==0 ){
     return pRight;
   }else if( pRight==0 ){
     return pLeft;
+  }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
+    sqlite3ExprDelete(db, pLeft);
+    sqlite3ExprDelete(db, pRight);
+    return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
   }else{
     Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
     sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
@@ -73438,7 +90102,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *
   }
   pNew->x.pList = pList;
   assert( !ExprHasProperty(pNew, EP_xIsSelect) );
-  sqlite3ExprSetHeight(pParse, pNew);
+  sqlite3ExprSetHeightAndFlags(pParse, pNew);
   return pNew;
 }
 
@@ -73455,7 +90119,7 @@ SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *
 **
 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
 ** as the previous instance of the same wildcard.  Or if this is the first
-** instance of the wildcard, the next sequenial variable number is
+** instance of the wildcard, the next sequential variable number is
 ** assigned.
 */
 SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
@@ -73463,7 +90127,7 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
   const char *z;
 
   if( pExpr==0 ) return;
-  assert( !ExprHasAnyProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
+  assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
   z = pExpr->u.zToken;
   assert( z!=0 );
   assert( z[0]!=0 );
@@ -73499,7 +90163,7 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
       */
       ynVar i;
       for(i=0; i<pParse->nzVar; i++){
-        if( pParse->azVar[i] && memcmp(pParse->azVar[i],z,n+1)==0 ){
+        if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
           pExpr->iColumn = x = (ynVar)i+1;
           break;
         }
@@ -73510,7 +90174,10 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
       if( x>pParse->nzVar ){
         char **a;
         a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
-        if( a==0 ) return;  /* Error reported through db->mallocFailed */
+        if( a==0 ){
+          assert( db->mallocFailed ); /* Error reported through mallocFailed */
+          return;
+        }
         pParse->azVar = a;
         memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
         pParse->nzVar = x;
@@ -73529,16 +90196,16 @@ SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
 /*
 ** Recursively delete an expression tree.
 */
-SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){
-  if( p==0 ) return;
+static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
+  assert( p!=0 );
   /* Sanity check: Assert that the IntValue is non-negative if it exists */
   assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
-  if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
+  if( !ExprHasProperty(p, EP_TokenOnly) ){
+    /* The Expr.x union is never used at the same time as Expr.pRight */
+    assert( p->x.pList==0 || p->pRight==0 );
     sqlite3ExprDelete(db, p->pLeft);
     sqlite3ExprDelete(db, p->pRight);
-    if( !ExprHasProperty(p, EP_Reduced) && (p->flags2 & EP2_MallocedToken)!=0 ){
-      sqlite3DbFree(db, p->u.zToken);
-    }
+    if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
     if( ExprHasProperty(p, EP_xIsSelect) ){
       sqlite3SelectDelete(db, p->x.pSelect);
     }else{
@@ -73549,6 +90216,9 @@ SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){
     sqlite3DbFree(db, p);
   }
 }
+SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){
+  if( p ) sqlite3ExprDeleteNN(db, p);
+}
 
 /*
 ** Return the number of bytes allocated for the expression structure 
@@ -73590,7 +90260,7 @@ static int exprStructSize(Expr *p){
 ** During expression analysis, extra information is computed and moved into
 ** later parts of teh Expr object and that extra information might get chopped
 ** off if the expression is reduced.  Note also that it does not work to
-** make a EXPRDUP_REDUCE copy of a reduced expression.  It is only legal
+** make an EXPRDUP_REDUCE copy of a reduced expression.  It is only legal
 ** to reduce a pristine expression tree from the parser.  The implementation
 ** of dupedExprStructSize() contain multiple assert() statements that attempt
 ** to enforce this constraint.
@@ -73598,16 +90268,19 @@ static int exprStructSize(Expr *p){
 static int dupedExprStructSize(Expr *p, int flags){
   int nSize;
   assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
-  if( 0==(flags&EXPRDUP_REDUCE) ){
+  assert( EXPR_FULLSIZE<=0xfff );
+  assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
+  if( 0==flags ){
     nSize = EXPR_FULLSIZE;
   }else{
-    assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
+    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
     assert( !ExprHasProperty(p, EP_FromJoin) ); 
-    assert( (p->flags2 & EP2_MallocedToken)==0 );
-    assert( (p->flags2 & EP2_Irreducible)==0 );
-    if( p->pLeft || p->pRight || p->pColl || p->x.pList ){
+    assert( !ExprHasProperty(p, EP_MemToken) );
+    assert( !ExprHasProperty(p, EP_NoReduce) );
+    if( p->pLeft || p->x.pList ){
       nSize = EXPR_REDUCEDSIZE | EP_Reduced;
     }else{
+      assert( p->pRight==0 );
       nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
     }
   }
@@ -73656,94 +90329,124 @@ static int dupedExprSize(Expr *p, int flags){
 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough 
 ** to store the copy of expression p, the copies of p->u.zToken
 ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
-** if any. Before returning, *pzBuffer is set to the first byte passed the
+** if any. Before returning, *pzBuffer is set to the first byte past the
 ** portion of the buffer copied into by this function.
 */
-static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
-  Expr *pNew = 0;                      /* Value to return */
-  if( p ){
-    const int isReduced = (flags&EXPRDUP_REDUCE);
-    u8 *zAlloc;
-    u32 staticFlag = 0;
+static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
+  Expr *pNew;           /* Value to return */
+  u8 *zAlloc;           /* Memory space from which to build Expr object */
+  u32 staticFlag;       /* EP_Static if space not obtained from malloc */
 
-    assert( pzBuffer==0 || isReduced );
+  assert( db!=0 );
+  assert( p );
+  assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );
+  assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );
+
+  /* Figure out where to write the new Expr structure. */
+  if( pzBuffer ){
+    zAlloc = *pzBuffer;
+    staticFlag = EP_Static;
+  }else{
+    zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));
+    staticFlag = 0;
+  }
+  pNew = (Expr *)zAlloc;
 
-    /* Figure out where to write the new Expr structure. */
-    if( pzBuffer ){
-      zAlloc = *pzBuffer;
-      staticFlag = EP_Static;
+  if( pNew ){
+    /* Set nNewSize to the size allocated for the structure pointed to
+    ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
+    ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
+    ** by the copy of the p->u.zToken string (if any).
+    */
+    const unsigned nStructSize = dupedExprStructSize(p, dupFlags);
+    const int nNewSize = nStructSize & 0xfff;
+    int nToken;
+    if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
+      nToken = sqlite3Strlen30(p->u.zToken) + 1;
     }else{
-      zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
+      nToken = 0;
     }
-    pNew = (Expr *)zAlloc;
-
-    if( pNew ){
-      /* Set nNewSize to the size allocated for the structure pointed to
-      ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
-      ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
-      ** by the copy of the p->u.zToken string (if any).
-      */
-      const unsigned nStructSize = dupedExprStructSize(p, flags);
-      const int nNewSize = nStructSize & 0xfff;
-      int nToken;
-      if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
-        nToken = sqlite3Strlen30(p->u.zToken) + 1;
-      }else{
-        nToken = 0;
-      }
-      if( isReduced ){
-        assert( ExprHasProperty(p, EP_Reduced)==0 );
-        memcpy(zAlloc, p, nNewSize);
-      }else{
-        int nSize = exprStructSize(p);
-        memcpy(zAlloc, p, nSize);
+    if( dupFlags ){
+      assert( ExprHasProperty(p, EP_Reduced)==0 );
+      memcpy(zAlloc, p, nNewSize);
+    }else{
+      u32 nSize = (u32)exprStructSize(p);
+      memcpy(zAlloc, p, nSize);
+      if( nSize<EXPR_FULLSIZE ){ 
         memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
       }
+    }
 
-      /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
-      pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
-      pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
-      pNew->flags |= staticFlag;
+    /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
+    pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
+    pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
+    pNew->flags |= staticFlag;
 
-      /* Copy the p->u.zToken string, if any. */
-      if( nToken ){
-        char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
-        memcpy(zToken, p->u.zToken, nToken);
-      }
-
-      if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
-        /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
-        if( ExprHasProperty(p, EP_xIsSelect) ){
-          pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
-        }else{
-          pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
-        }
-      }
+    /* Copy the p->u.zToken string, if any. */
+    if( nToken ){
+      char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
+      memcpy(zToken, p->u.zToken, nToken);
+    }
 
-      /* Fill in pNew->pLeft and pNew->pRight. */
-      if( ExprHasAnyProperty(pNew, EP_Reduced|EP_TokenOnly) ){
-        zAlloc += dupedExprNodeSize(p, flags);
-        if( ExprHasProperty(pNew, EP_Reduced) ){
-          pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
-          pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
-        }
-        if( pzBuffer ){
-          *pzBuffer = zAlloc;
-        }
+    if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
+      /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
+      if( ExprHasProperty(p, EP_xIsSelect) ){
+        pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
       }else{
-        pNew->flags2 = 0;
-        if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
-          pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
-          pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
-        }
+        pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
       }
+    }
 
+    /* Fill in pNew->pLeft and pNew->pRight. */
+    if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
+      zAlloc += dupedExprNodeSize(p, dupFlags);
+      if( ExprHasProperty(pNew, EP_Reduced) ){
+        pNew->pLeft = p->pLeft ?
+                      exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;
+        pNew->pRight = p->pRight ?
+                       exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
+      }
+      if( pzBuffer ){
+        *pzBuffer = zAlloc;
+      }
+    }else{
+      if( !ExprHasProperty(p, EP_TokenOnly) ){
+        pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
+        pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
+      }
     }
   }
   return pNew;
 }
 
 /*
+** Create and return a deep copy of the object passed as the second 
+** argument. If an OOM condition is encountered, NULL is returned
+** and the db->mallocFailed flag set.
+*/
+#ifndef SQLITE_OMIT_CTE
+static With *withDup(sqlite3 *db, With *p){
+  With *pRet = 0;
+  if( p ){
+    int nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);
+    pRet = sqlite3DbMallocZero(db, nByte);
+    if( pRet ){
+      int i;
+      pRet->nCte = p->nCte;
+      for(i=0; i<p->nCte; i++){
+        pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);
+        pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);
+        pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);
+      }
+    }
+  }
+  return pRet;
+}
+#else
+# define withDup(x,y) 0
+#endif
+
+/*
 ** The following group of routines make deep copies of expressions,
 ** expression lists, ID lists, and select statements.  The copies can
 ** be deleted (by being passed to their respective ...Delete() routines)
@@ -73761,18 +90464,20 @@ static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
 ** part of the in-memory representation of the database schema.
 */
 SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
-  return exprDup(db, p, flags, 0);
+  assert( flags==0 || flags==EXPRDUP_REDUCE );
+  return p ? exprDup(db, p, flags, 0) : 0;
 }
 SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
   ExprList *pNew;
   struct ExprList_item *pItem, *pOldItem;
   int i;
+  assert( db!=0 );
   if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
   if( pNew==0 ) return 0;
-  pNew->iECursor = 0;
-  pNew->nExpr = pNew->nAlloc = p->nExpr;
-  pNew->a = pItem = sqlite3DbMallocRaw(db,  p->nExpr*sizeof(p->a[0]) );
+  pNew->nExpr = i = p->nExpr;
+  if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){}
+  pNew->a = pItem = sqlite3DbMallocRawNN(db,  i*sizeof(p->a[0]) );
   if( pItem==0 ){
     sqlite3DbFree(db, pNew);
     return 0;
@@ -73785,8 +90490,8 @@ SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags)
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
     pItem->sortOrder = pOldItem->sortOrder;
     pItem->done = 0;
-    pItem->iCol = pOldItem->iCol;
-    pItem->iAlias = pOldItem->iAlias;
+    pItem->bSpanIsTab = pOldItem->bSpanIsTab;
+    pItem->u = pOldItem->u;
   }
   return pNew;
 }
@@ -73803,26 +90508,32 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
   SrcList *pNew;
   int i;
   int nByte;
+  assert( db!=0 );
   if( p==0 ) return 0;
   nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
-  pNew = sqlite3DbMallocRaw(db, nByte );
+  pNew = sqlite3DbMallocRawNN(db, nByte );
   if( pNew==0 ) return 0;
   pNew->nSrc = pNew->nAlloc = p->nSrc;
   for(i=0; i<p->nSrc; i++){
     struct SrcList_item *pNewItem = &pNew->a[i];
     struct SrcList_item *pOldItem = &p->a[i];
     Table *pTab;
+    pNewItem->pSchema = pOldItem->pSchema;
     pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
     pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
-    pNewItem->jointype = pOldItem->jointype;
+    pNewItem->fg = pOldItem->fg;
     pNewItem->iCursor = pOldItem->iCursor;
     pNewItem->addrFillSub = pOldItem->addrFillSub;
     pNewItem->regReturn = pOldItem->regReturn;
-    pNewItem->isCorrelated = pOldItem->isCorrelated;
-    pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
-    pNewItem->notIndexed = pOldItem->notIndexed;
-    pNewItem->pIndex = pOldItem->pIndex;
+    if( pNewItem->fg.isIndexedBy ){
+      pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
+    }
+    pNewItem->pIBIndex = pOldItem->pIBIndex;
+    if( pNewItem->fg.isTabFunc ){
+      pNewItem->u1.pFuncArg = 
+          sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
+    }
     pTab = pNewItem->pTab = pOldItem->pTab;
     if( pTab ){
       pTab->nRef++;
@@ -73837,15 +90548,19 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
 SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
   IdList *pNew;
   int i;
+  assert( db!=0 );
   if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
+  pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
   if( pNew==0 ) return 0;
-  pNew->nId = pNew->nAlloc = p->nId;
-  pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
+  pNew->nId = p->nId;
+  pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );
   if( pNew->a==0 ){
     sqlite3DbFree(db, pNew);
     return 0;
   }
+  /* Note that because the size of the allocation for p->a[] is not
+  ** necessarily a power of two, sqlite3IdListAppend() may not be called
+  ** on the duplicate created by this function. */
   for(i=0; i<p->nId; i++){
     struct IdList_item *pNewItem = &pNew->a[i];
     struct IdList_item *pOldItem = &p->a[i];
@@ -73855,9 +90570,10 @@ SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
   return pNew;
 }
 SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
-  Select *pNew;
+  Select *pNew, *pPrior;
+  assert( db!=0 );
   if( p==0 ) return 0;
-  pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
+  pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );
   if( pNew==0 ) return 0;
   pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
   pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
@@ -73866,16 +90582,19 @@ SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
   pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
   pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
   pNew->op = p->op;
-  pNew->pPrior = sqlite3SelectDup(db, p->pPrior, flags);
+  pNew->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags);
+  if( pPrior ) pPrior->pNext = pNew;
+  pNew->pNext = 0;
   pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
   pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
   pNew->iLimit = 0;
   pNew->iOffset = 0;
   pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
-  pNew->pRightmost = 0;
   pNew->addrOpenEphm[0] = -1;
   pNew->addrOpenEphm[1] = -1;
-  pNew->addrOpenEphm[2] = -1;
+  pNew->nSelectRow = p->nSelectRow;
+  pNew->pWith = withDup(db, p->pWith);
+  sqlite3SelectSetName(pNew, p->zSelName);
   return pNew;
 }
 #else
@@ -73900,22 +90619,23 @@ SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(
   Expr *pExpr             /* Expression to be appended. Might be NULL */
 ){
   sqlite3 *db = pParse->db;
+  assert( db!=0 );
   if( pList==0 ){
-    pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
+    pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );
     if( pList==0 ){
       goto no_mem;
     }
-    assert( pList->nAlloc==0 );
-  }
-  if( pList->nAlloc<=pList->nExpr ){
+    pList->nExpr = 0;
+    pList->a = sqlite3DbMallocRawNN(db, sizeof(pList->a[0]));
+    if( pList->a==0 ) goto no_mem;
+  }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
     struct ExprList_item *a;
-    int n = pList->nAlloc*2 + 4;
-    a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
+    assert( pList->nExpr>0 );
+    a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
     if( a==0 ){
       goto no_mem;
     }
     pList->a = a;
-    pList->nAlloc = sqlite3DbMallocSize(db, a)/sizeof(a[0]);
   }
   assert( pList->a!=0 );
   if( 1 ){
@@ -73933,6 +90653,20 @@ no_mem:
 }
 
 /*
+** Set the sort order for the last element on the given ExprList.
+*/
+SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
+  if( p==0 ) return;
+  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );
+  assert( p->nExpr>0 );
+  if( iSortOrder<0 ){
+    assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC );
+    return;
+  }
+  p->a[p->nExpr-1].sortOrder = (u8)iSortOrder;
+}
+
+/*
 ** Set the ExprList.a[].zName element of the most recently added item
 ** on the expression list.
 **
@@ -73953,7 +90687,7 @@ SQLITE_PRIVATE void sqlite3ExprListSetName(
     pItem = &pList->a[pList->nExpr-1];
     assert( pItem->zName==0 );
     pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
-    if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName);
+    if( dequote ) sqlite3Dequote(pItem->zName);
   }
 }
 
@@ -74002,12 +90736,10 @@ SQLITE_PRIVATE void sqlite3ExprListCheckLength(
 /*
 ** Delete an entire expression list.
 */
-SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
+static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){
   int i;
   struct ExprList_item *pItem;
-  if( pList==0 ) return;
-  assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
-  assert( pList->nExpr<=pList->nAlloc );
+  assert( pList->a!=0 || pList->nExpr==0 );
   for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
     sqlite3ExprDelete(db, pItem->pExpr);
     sqlite3DbFree(db, pItem->zName);
@@ -74016,36 +90748,73 @@ SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
   sqlite3DbFree(db, pList->a);
   sqlite3DbFree(db, pList);
 }
+SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
+  if( pList ) exprListDeleteNN(db, pList);
+}
+
+/*
+** Return the bitwise-OR of all Expr.flags fields in the given
+** ExprList.
+*/
+SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList *pList){
+  int i;
+  u32 m = 0;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+       Expr *pExpr = pList->a[i].pExpr;
+       assert( pExpr!=0 );
+       m |= pExpr->flags;
+    }
+  }
+  return m;
+}
 
 /*
-** These routines are Walker callbacks.  Walker.u.pi is a pointer
-** to an integer.  These routines are checking an expression to see
-** if it is a constant.  Set *Walker.u.pi to 0 if the expression is
-** not constant.
+** These routines are Walker callbacks used to check expressions to
+** see if they are "constant" for some definition of constant.  The
+** Walker.eCode value determines the type of "constant" we are looking
+** for.
 **
 ** These callback routines are used to implement the following:
 **
-**     sqlite3ExprIsConstant()
-**     sqlite3ExprIsConstantNotJoin()
-**     sqlite3ExprIsConstantOrFunction()
+**     sqlite3ExprIsConstant()                  pWalker->eCode==1
+**     sqlite3ExprIsConstantNotJoin()           pWalker->eCode==2
+**     sqlite3ExprIsTableConstant()             pWalker->eCode==3
+**     sqlite3ExprIsConstantOrFunction()        pWalker->eCode==4 or 5
+**
+** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
+** is found to not be a constant.
 **
+** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions
+** in a CREATE TABLE statement.  The Walker.eCode value is 5 when parsing
+** an existing schema and 4 when processing a new statement.  A bound
+** parameter raises an error for new statements, but is silently converted
+** to NULL for existing schemas.  This allows sqlite_master tables that 
+** contain a bound parameter because they were generated by older versions
+** of SQLite to be parsed by newer versions of SQLite without raising a
+** malformed schema error.
 */
 static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
 
-  /* If pWalker->u.i is 3 then any term of the expression that comes from
-  ** the ON or USING clauses of a join disqualifies the expression
+  /* If pWalker->eCode is 2 then any term of the expression that comes from
+  ** the ON or USING clauses of a left join disqualifies the expression
   ** from being considered constant. */
-  if( pWalker->u.i==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
-    pWalker->u.i = 0;
+  if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){
+    pWalker->eCode = 0;
     return WRC_Abort;
   }
 
   switch( pExpr->op ){
     /* Consider functions to be constant if all their arguments are constant
-    ** and pWalker->u.i==2 */
+    ** and either pWalker->eCode==4 or 5 or the function has the
+    ** SQLITE_FUNC_CONST flag. */
     case TK_FUNCTION:
-      if( pWalker->u.i==2 ) return 0;
-      /* Fall through */
+      if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc) ){
+        return WRC_Continue;
+      }else{
+        pWalker->eCode = 0;
+        return WRC_Abort;
+      }
     case TK_ID:
     case TK_COLUMN:
     case TK_AGG_FUNCTION:
@@ -74054,8 +90823,25 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_COLUMN );
       testcase( pExpr->op==TK_AGG_FUNCTION );
       testcase( pExpr->op==TK_AGG_COLUMN );
-      pWalker->u.i = 0;
-      return WRC_Abort;
+      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
+        return WRC_Continue;
+      }else{
+        pWalker->eCode = 0;
+        return WRC_Abort;
+      }
+    case TK_VARIABLE:
+      if( pWalker->eCode==5 ){
+        /* Silently convert bound parameters that appear inside of CREATE
+        ** statements into a NULL when parsing the CREATE statement text out
+        ** of the sqlite_master table */
+        pExpr->op = TK_NULL;
+      }else if( pWalker->eCode==4 ){
+        /* A bound parameter in a CREATE statement that originates from
+        ** sqlite3_prepare() causes an error */
+        pWalker->eCode = 0;
+        return WRC_Abort;
+      }
+      /* Fall through */
     default:
       testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
       testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
@@ -74064,20 +90850,22 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
 }
 static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
   UNUSED_PARAMETER(NotUsed);
-  pWalker->u.i = 0;
+  pWalker->eCode = 0;
   return WRC_Abort;
 }
-static int exprIsConst(Expr *p, int initFlag){
+static int exprIsConst(Expr *p, int initFlag, int iCur){
   Walker w;
-  w.u.i = initFlag;
+  memset(&w, 0, sizeof(w));
+  w.eCode = initFlag;
   w.xExprCallback = exprNodeIsConstant;
   w.xSelectCallback = selectNodeIsConstant;
+  w.u.iCur = iCur;
   sqlite3WalkExpr(&w, p);
-  return w.u.i;
+  return w.eCode;
 }
 
 /*
-** Walk an expression tree.  Return 1 if the expression is constant
+** Walk an expression tree.  Return non-zero if the expression is constant
 ** and 0 if it involves variables or function calls.
 **
 ** For the purposes of this function, a double-quoted string (ex: "abc")
@@ -74085,21 +90873,31 @@ static int exprIsConst(Expr *p, int initFlag){
 ** a constant.
 */
 SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr *p){
-  return exprIsConst(p, 1);
+  return exprIsConst(p, 1, 0);
 }
 
 /*
-** Walk an expression tree.  Return 1 if the expression is constant
+** Walk an expression tree.  Return non-zero if the expression is constant
 ** that does no originate from the ON or USING clauses of a join.
 ** Return 0 if it involves variables or function calls or terms from
 ** an ON or USING clause.
 */
 SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr *p){
-  return exprIsConst(p, 3);
+  return exprIsConst(p, 2, 0);
+}
+
+/*
+** Walk an expression tree.  Return non-zero if the expression is constant
+** for any single row of the table with cursor iCur.  In other words, the
+** expression must not refer to any non-deterministic function nor any
+** table other than iCur.
+*/
+SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr *p, int iCur){
+  return exprIsConst(p, 3, iCur);
 }
 
 /*
-** Walk an expression tree.  Return 1 if the expression is constant
+** Walk an expression tree.  Return non-zero if the expression is constant
 ** or a function call with constant arguments.  Return and 0 if there
 ** are any variables.
 **
@@ -74107,10 +90905,27 @@ SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr *p){
 ** is considered a variable but a single-quoted string (ex: 'abc') is
 ** a constant.
 */
-SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr *p){
-  return exprIsConst(p, 2);
+SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
+  assert( isInit==0 || isInit==1 );
+  return exprIsConst(p, 4+isInit, 0);
 }
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Walk an expression tree.  Return 1 if the expression contains a
+** subquery of some kind.  Return 0 if there are no subqueries.
+*/
+SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr *p){
+  Walker w;
+  memset(&w, 0, sizeof(w));
+  w.eCode = 1;
+  w.xExprCallback = sqlite3ExprWalkNoop;
+  w.xSelectCallback = selectNodeIsConstant;
+  sqlite3WalkExpr(&w, p);
+  return w.eCode==0;
+}
+#endif
+
 /*
 ** If the expression p codes a constant integer that is small enough
 ** to fit in a 32-bit integer, return 1 and put the value of the integer
@@ -74137,6 +90952,7 @@ SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr *p, int *pValue){
     case TK_UMINUS: {
       int v;
       if( sqlite3ExprIsInteger(p->pLeft, &v) ){
+        assert( v!=(-2147483647-1) );
         *pValue = -v;
         rc = 1;
       }
@@ -74172,30 +90988,16 @@ SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr *p){
     case TK_FLOAT:
     case TK_BLOB:
       return 0;
+    case TK_COLUMN:
+      assert( p->pTab!=0 );
+      return ExprHasProperty(p, EP_CanBeNull) ||
+             (p->iColumn>=0 && p->pTab->aCol[p->iColumn].notNull==0);
     default:
       return 1;
   }
 }
 
 /*
-** Generate an OP_IsNull instruction that tests register iReg and jumps
-** to location iDest if the value in iReg is NULL.  The value in iReg 
-** was computed by pExpr.  If we can look at pExpr at compile-time and
-** determine that it can never generate a NULL, then the OP_IsNull operation
-** can be omitted.
-*/
-SQLITE_PRIVATE void sqlite3ExprCodeIsNullJump(
-  Vdbe *v,            /* The VDBE under construction */
-  const Expr *pExpr,  /* Only generate OP_IsNull if this expr can be NULL */
-  int iReg,           /* Test the value in this register for NULL */
-  int iDest           /* Jump here if the value is null */
-){
-  if( sqlite3ExprCanBeNull(pExpr) ){
-    sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest);
-  }
-}
-
-/*
 ** Return TRUE if the given expression is a constant which would be
 ** unchanged by OP_Affinity with the affinity given in the second
 ** argument.
@@ -74207,7 +91009,7 @@ SQLITE_PRIVATE void sqlite3ExprCodeIsNullJump(
 */
 SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
   u8 op;
-  if( aff==SQLITE_AFF_NONE ) return 1;
+  if( aff==SQLITE_AFF_BLOB ) return 1;
   while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
   op = p->op;
   if( op==TK_REGISTER ) op = p->op2;
@@ -74246,23 +91048,22 @@ SQLITE_PRIVATE int sqlite3IsRowid(const char *z){
 }
 
 /*
-** Return true if we are able to the IN operator optimization on a
-** query of the form
-**
-**       x IN (SELECT ...)
-**
-** Where the SELECT... clause is as specified by the parameter to this
-** routine.
-**
-** The Select object passed in has already been preprocessed and no
-** errors have been found.
+** pX is the RHS of an IN operator.  If pX is a SELECT statement 
+** that can be simplified to a direct table access, then return
+** a pointer to the SELECT statement.  If pX is not a SELECT statement,
+** or if the SELECT statement needs to be manifested into a transient
+** table, then return NULL.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
-static int isCandidateForInOpt(Select *p){
+static Select *isCandidateForInOpt(Expr *pX){
+  Select *p;
   SrcList *pSrc;
   ExprList *pEList;
+  Expr *pRes;
   Table *pTab;
-  if( p==0 ) return 0;                   /* right-hand side of IN is SELECT */
+  if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0;  /* Not a subquery */
+  if( ExprHasProperty(pX, EP_VarSelect)  ) return 0;  /* Correlated subq */
+  p = pX->x.pSelect;
   if( p->pPrior ) return 0;              /* Not a compound SELECT */
   if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
     testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
@@ -74278,101 +91079,161 @@ static int isCandidateForInOpt(Select *p){
   if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
   if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
   pTab = pSrc->a[0].pTab;
-  if( NEVER(pTab==0) ) return 0;
+  assert( pTab!=0 );
   assert( pTab->pSelect==0 );            /* FROM clause is not a view */
   if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
   pEList = p->pEList;
   if( pEList->nExpr!=1 ) return 0;       /* One column in the result set */
-  if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
-  return 1;
+  pRes = pEList->a[0].pExpr;
+  if( pRes->op!=TK_COLUMN ) return 0;    /* Result is a column */
+  assert( pRes->iTable==pSrc->a[0].iCursor );  /* Not a correlated subquery */
+  return p;
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
 /*
+** Code an OP_Once instruction and allocate space for its flag. Return the 
+** address of the new instruction.
+*/
+SQLITE_PRIVATE int sqlite3CodeOnce(Parse *pParse){
+  Vdbe *v = sqlite3GetVdbe(pParse);      /* Virtual machine being coded */
+  return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
+}
+
+/*
+** Generate code that checks the left-most column of index table iCur to see if
+** it contains any NULL entries.  Cause the register at regHasNull to be set
+** to a non-NULL value if iCur contains no NULLs.  Cause register regHasNull
+** to be set to NULL if iCur contains one or more NULL values.
+*/
+static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
+  int addr1;
+  sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
+  addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
+  sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
+  sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
+  VdbeComment((v, "first_entry_in(%d)", iCur));
+  sqlite3VdbeJumpHere(v, addr1);
+}
+
+
+#ifndef SQLITE_OMIT_SUBQUERY
+/*
+** The argument is an IN operator with a list (not a subquery) on the 
+** right-hand side.  Return TRUE if that list is constant.
+*/
+static int sqlite3InRhsIsConstant(Expr *pIn){
+  Expr *pLHS;
+  int res;
+  assert( !ExprHasProperty(pIn, EP_xIsSelect) );
+  pLHS = pIn->pLeft;
+  pIn->pLeft = 0;
+  res = sqlite3ExprIsConstant(pIn);
+  pIn->pLeft = pLHS;
+  return res;
+}
+#endif
+
+/*
 ** This function is used by the implementation of the IN (...) operator.
-** It's job is to find or create a b-tree structure that may be used
-** either to test for membership of the (...) set or to iterate through
-** its members, skipping duplicates.
+** The pX parameter is the expression on the RHS of the IN operator, which
+** might be either a list of expressions or a subquery.
+**
+** The job of this routine is to find or create a b-tree object that can
+** be used either to test for membership in the RHS set or to iterate through
+** all members of the RHS set, skipping duplicates.
+**
+** A cursor is opened on the b-tree object that is the RHS of the IN operator
+** and pX->iTable is set to the index of that cursor.
 **
-** The index of the cursor opened on the b-tree (database table, database index 
-** or ephermal table) is stored in pX->iTable before this function returns.
 ** The returned value of this function indicates the b-tree type, as follows:
 **
-**   IN_INDEX_ROWID - The cursor was opened on a database table.
-**   IN_INDEX_INDEX - The cursor was opened on a database index.
-**   IN_INDEX_EPH -   The cursor was opened on a specially created and
-**                    populated epheremal table.
+**   IN_INDEX_ROWID      - The cursor was opened on a database table.
+**   IN_INDEX_INDEX_ASC  - The cursor was opened on an ascending index.
+**   IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
+**   IN_INDEX_EPH        - The cursor was opened on a specially created and
+**                         populated epheremal table.
+**   IN_INDEX_NOOP       - No cursor was allocated.  The IN operator must be
+**                         implemented as a sequence of comparisons.
 **
-** An existing b-tree may only be used if the SELECT is of the simple
-** form:
+** An existing b-tree might be used if the RHS expression pX is a simple
+** subquery such as:
 **
 **     SELECT <column> FROM <table>
 **
-** If the prNotFound parameter is 0, then the b-tree will be used to iterate
-** through the set members, skipping any duplicates. In this case an
-** epheremal table must be used unless the selected <column> is guaranteed
+** If the RHS of the IN operator is a list or a more complex subquery, then
+** an ephemeral table might need to be generated from the RHS and then
+** pX->iTable made to point to the ephemeral table instead of an
+** existing table.
+**
+** The inFlags parameter must contain exactly one of the bits
+** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP.  If inFlags contains
+** IN_INDEX_MEMBERSHIP, then the generated table will be used for a
+** fast membership test.  When the IN_INDEX_LOOP bit is set, the
+** IN index will be used to loop over all values of the RHS of the
+** IN operator.
+**
+** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
+** through the set members) then the b-tree must not contain duplicates.
+** An epheremal table must be used unless the selected <column> is guaranteed
 ** to be unique - either because it is an INTEGER PRIMARY KEY or it
 ** has a UNIQUE constraint or UNIQUE index.
 **
-** If the prNotFound parameter is not 0, then the b-tree will be used 
-** for fast set membership tests. In this case an epheremal table must 
+** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used 
+** for fast set membership tests) then an epheremal table must 
 ** be used unless <column> is an INTEGER PRIMARY KEY or an index can 
 ** be found with <column> as its left-most column.
 **
+** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
+** if the RHS of the IN operator is a list (not a subquery) then this
+** routine might decide that creating an ephemeral b-tree for membership
+** testing is too expensive and return IN_INDEX_NOOP.  In that case, the
+** calling routine should implement the IN operator using a sequence
+** of Eq or Ne comparison operations.
+**
 ** When the b-tree is being used for membership tests, the calling function
-** needs to know whether or not the structure contains an SQL NULL 
-** value in order to correctly evaluate expressions like "X IN (Y, Z)".
-** If there is any chance that the (...) might contain a NULL value at
+** might need to know whether or not the RHS side of the IN operator
+** contains a NULL.  If prRhsHasNull is not a NULL pointer and 
+** if there is any chance that the (...) might contain a NULL value at
 ** runtime, then a register is allocated and the register number written
-** to *prNotFound. If there is no chance that the (...) contains a
-** NULL value, then *prNotFound is left unchanged.
-**
-** If a register is allocated and its location stored in *prNotFound, then
-** its initial value is NULL.  If the (...) does not remain constant
-** for the duration of the query (i.e. the SELECT within the (...)
-** is a correlated subquery) then the value of the allocated register is
-** reset to NULL each time the subquery is rerun. This allows the
-** caller to use vdbe code equivalent to the following:
-**
-**   if( register==NULL ){
-**     has_null = <test if data structure contains null>
-**     register = 1
-**   }
+** to *prRhsHasNull. If there is no chance that the (...) contains a
+** NULL value, then *prRhsHasNull is left unchanged.
 **
-** in order to avoid running the <test if data structure contains null>
-** test more often than is necessary.
+** If a register is allocated and its location stored in *prRhsHasNull, then
+** the value in that register will be NULL if the b-tree contains one or more
+** NULL values, and it will be some non-NULL value if the b-tree contains no
+** NULL values.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
-SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
+SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
   Select *p;                            /* SELECT to the right of IN operator */
   int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
   int iTab = pParse->nTab++;            /* Cursor of the RHS table */
-  int mustBeUnique = (prNotFound==0);   /* True if RHS must be unique */
+  int mustBeUnique;                     /* True if RHS must be unique */
+  Vdbe *v = sqlite3GetVdbe(pParse);     /* Virtual machine being coded */
 
   assert( pX->op==TK_IN );
+  mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
 
   /* Check to see if an existing table or index can be used to
   ** satisfy the query.  This is preferable to generating a new 
   ** ephemeral table.
   */
-  p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
-  if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
+  if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
     sqlite3 *db = pParse->db;              /* Database connection */
-    Vdbe *v = sqlite3GetVdbe(pParse);      /* Virtual machine being coded */
     Table *pTab;                           /* Table <table>. */
     Expr *pExpr;                           /* Expression <column> */
-    int iCol;                              /* Index of column <column> */
-    int iDb;                               /* Database idx for pTab */
+    i16 iCol;                              /* Index of column <column> */
+    i16 iDb;                               /* Database idx for pTab */
 
-    assert( p );                        /* Because of isCandidateForInOpt(p) */
     assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
     assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
     assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
     pTab = p->pSrc->a[0].pTab;
     pExpr = p->pEList->a[0].pExpr;
-    iCol = pExpr->iColumn;
+    iCol = (i16)pExpr->iColumn;
    
-    /* Code an OP_VerifyCookie and OP_TableLock for <table>. */
+    /* Code an OP_Transaction and OP_TableLock for <table>. */
     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
     sqlite3CodeVerifySchema(pParse, iDb);
     sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
@@ -74383,10 +91244,8 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
     */
     assert(v);
     if( iCol<0 ){
-      int iMem = ++pParse->nMem;
-      int iAddr;
-
-      iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
+      int iAddr = sqlite3CodeOnce(pParse);
+      VdbeCoverage(v);
 
       sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
       eType = IN_INDEX_ROWID;
@@ -74404,50 +91263,65 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
       ** comparison is the same as the affinity of the column. If
       ** it is not, it is not possible to use any index.
       */
-      char aff = comparisonAffinity(pX);
-      int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
+      int affinity_ok = sqlite3IndexAffinityOk(pX, pTab->aCol[iCol].affinity);
 
       for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
         if( (pIdx->aiColumn[0]==iCol)
          && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq
-         && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
+         && (!mustBeUnique || (pIdx->nKeyCol==1 && IsUniqueIndex(pIdx)))
         ){
-          int iMem = ++pParse->nMem;
-          int iAddr;
-          char *pKey;
-  
-          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
-          iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
-  
-          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
-                               pKey,P4_KEYINFO_HANDOFF);
+          int iAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+          sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
+          sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
           VdbeComment((v, "%s", pIdx->zName));
-          eType = IN_INDEX_INDEX;
+          assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
+          eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
 
-          sqlite3VdbeJumpHere(v, iAddr);
-          if( prNotFound && !pTab->aCol[iCol].notNull ){
-            *prNotFound = ++pParse->nMem;
+          if( prRhsHasNull && !pTab->aCol[iCol].notNull ){
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+            const i64 sOne = 1;
+            sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, 
+                iTab, 0, 0, (u8*)&sOne, P4_INT64);
+#endif
+            *prRhsHasNull = ++pParse->nMem;
+            sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
           }
+          sqlite3VdbeJumpHere(v, iAddr);
         }
       }
     }
   }
 
+  /* If no preexisting index is available for the IN clause
+  ** and IN_INDEX_NOOP is an allowed reply
+  ** and the RHS of the IN operator is a list, not a subquery
+  ** and the RHS is not constant or has two or fewer terms,
+  ** then it is not worth creating an ephemeral table to evaluate
+  ** the IN operator so return IN_INDEX_NOOP.
+  */
+  if( eType==0
+   && (inFlags & IN_INDEX_NOOP_OK)
+   && !ExprHasProperty(pX, EP_xIsSelect)
+   && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
+  ){
+    eType = IN_INDEX_NOOP;
+  }
+     
+
   if( eType==0 ){
-    /* Could not found an existing table or index to use as the RHS b-tree.
+    /* Could not find an existing table or index to use as the RHS b-tree.
     ** We will have to generate an ephemeral table to do the job.
     */
-    double savedNQueryLoop = pParse->nQueryLoop;
+    u32 savedNQueryLoop = pParse->nQueryLoop;
     int rMayHaveNull = 0;
     eType = IN_INDEX_EPH;
-    if( prNotFound ){
-      *prNotFound = rMayHaveNull = ++pParse->nMem;
-    }else{
-      testcase( pParse->nQueryLoop>(double)1 );
-      pParse->nQueryLoop = (double)1;
-      if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
+    if( inFlags & IN_INDEX_LOOP ){
+      pParse->nQueryLoop = 0;
+      if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
         eType = IN_INDEX_ROWID;
       }
+    }else if( prRhsHasNull ){
+      *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
     }
     sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
     pParse->nQueryLoop = savedNQueryLoop;
@@ -74478,15 +91352,9 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
 **
 ** If rMayHaveNull is non-zero, that means that the operation is an IN
 ** (not a SELECT or EXISTS) and that the RHS might contains NULLs.
-** Furthermore, the IN is in a WHERE clause and that we really want
-** to iterate over the RHS of the IN operator in order to quickly locate
-** all corresponding LHS elements.  All this routine does is initialize
-** the register given by rMayHaveNull to NULL.  Calling routines will take
-** care of changing this register value to non-NULL if the RHS is NULL-free.
-**
-** If rMayHaveNull is zero, that means that the subquery is being used
-** for membership testing only.  There is no need to initialize any
-** registers to indicate the presense or absence of NULLs on the RHS.
+** All this routine does is initialize the register given by rMayHaveNull
+** to NULL.  Calling routines will take care of changing this register
+** value to non-NULL if the RHS is NULL-free.
 **
 ** For a SELECT or EXISTS operator, return the register that holds the
 ** result.  For IN operators or if an error occurs, the return value is 0.
@@ -74495,10 +91363,10 @@ SQLITE_PRIVATE int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
 SQLITE_PRIVATE int sqlite3CodeSubselect(
   Parse *pParse,          /* Parsing context */
   Expr *pExpr,            /* The IN, SELECT, or EXISTS operator */
-  int rMayHaveNull,       /* Register that records whether NULLs exist in RHS */
+  int rHasNullFlag,       /* Register that records whether NULLs exist in RHS */
   int isRowid             /* If true, LHS of IN operator is a rowid */
 ){
-  int testAddr = -1;                      /* One-time test address */
+  int jmpIfDynamic = -1;                      /* One-time test address */
   int rReg = 0;                           /* Register storing resulting */
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( NEVER(v==0) ) return 0;
@@ -74514,16 +91382,16 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
   ** If all of the above are false, then we can run this code just once
   ** save the results, and reuse the same result on subsequent invocations.
   */
-  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->pTriggerTab ){
-    int mem = ++pParse->nMem;
-    testAddr = sqlite3VdbeAddOp1(v, OP_Once, mem);
+  if( !ExprHasProperty(pExpr, EP_VarSelect) ){
+    jmpIfDynamic = sqlite3CodeOnce(pParse); VdbeCoverage(v);
   }
 
 #ifndef SQLITE_OMIT_EXPLAIN
   if( pParse->explain==2 ){
-    char *zMsg = sqlite3MPrintf(
-        pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ",
-        pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId
+    char *zMsg = sqlite3MPrintf(pParse->db, "EXECUTE %s%s SUBQUERY %d",
+        jmpIfDynamic>=0?"":"CORRELATED ",
+        pExpr->op==TK_IN?"LIST":"SCALAR",
+        pParse->iNextSelectId
     );
     sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
   }
@@ -74532,13 +91400,9 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
   switch( pExpr->op ){
     case TK_IN: {
       char affinity;              /* Affinity of the LHS of the IN */
-      KeyInfo keyInfo;            /* Keyinfo for the generated table */
       int addr;                   /* Address of OP_OpenEphemeral instruction */
       Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
-
-      if( rMayHaveNull ){
-        sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
-      }
+      KeyInfo *pKeyInfo = 0;      /* Key information */
 
       affinity = sqlite3ExprAffinity(pLeft);
 
@@ -74557,9 +91421,7 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
       */
       pExpr->iTable = pParse->nTab++;
       addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
-      if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
-      memset(&keyInfo, 0, sizeof(keyInfo));
-      keyInfo.nField = 1;
+      pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, 1, 1);
 
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         /* Case 1:     expr IN (SELECT ...)
@@ -74567,22 +91429,28 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         ** Generate code to write the results of the select into the temporary
         ** table allocated and opened above.
         */
+        Select *pSelect = pExpr->x.pSelect;
         SelectDest dest;
         ExprList *pEList;
 
         assert( !isRowid );
         sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
-        dest.affinity = (u8)affinity;
+        dest.affSdst = (u8)affinity;
         assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
-        pExpr->x.pSelect->iLimit = 0;
-        if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
+        pSelect->iLimit = 0;
+        testcase( pSelect->selFlags & SF_Distinct );
+        testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
+        if( sqlite3Select(pParse, pSelect, &dest) ){
+          sqlite3KeyInfoUnref(pKeyInfo);
           return 0;
         }
-        pEList = pExpr->x.pSelect->pEList;
-        if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){ 
-          keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
-              pEList->a[0].pExpr);
-        }
+        pEList = pSelect->pEList;
+        assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
+        assert( pEList!=0 );
+        assert( pEList->nExpr>0 );
+        assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
+        pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
+                                                         pEList->a[0].pExpr);
       }else if( ALWAYS(pExpr->x.pList!=0) ){
         /* Case 2:     expr IN (exprlist)
         **
@@ -74597,14 +91465,17 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         int r1, r2, r3;
 
         if( !affinity ){
-          affinity = SQLITE_AFF_NONE;
+          affinity = SQLITE_AFF_BLOB;
+        }
+        if( pKeyInfo ){
+          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
+          pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
         }
-        keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
 
         /* Loop through each expression in <exprlist>. */
         r1 = sqlite3GetTempReg(pParse);
         r2 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
+        if( isRowid ) sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
         for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
           Expr *pE2 = pItem->pExpr;
           int iValToIns;
@@ -74614,9 +91485,9 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
           ** this code only executes once.  Because for a non-constant
           ** expression we need to rerun this code each time.
           */
-          if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
-            sqlite3VdbeChangeToNoop(v, testAddr);
-            testAddr = -1;
+          if( jmpIfDynamic>=0 && !sqlite3ExprIsConstant(pE2) ){
+            sqlite3VdbeChangeToNoop(v, jmpIfDynamic);
+            jmpIfDynamic = -1;
           }
 
           /* Evaluate the expression and insert it into the temp table */
@@ -74627,6 +91498,7 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
             if( isRowid ){
               sqlite3VdbeAddOp2(v, OP_MustBeInt, r3,
                                 sqlite3VdbeCurrentAddr(v)+2);
+              VdbeCoverage(v);
               sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
             }else{
               sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
@@ -74638,8 +91510,8 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
         sqlite3ReleaseTempReg(pParse, r1);
         sqlite3ReleaseTempReg(pParse, r2);
       }
-      if( !isRowid ){
-        sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
+      if( pKeyInfo ){
+        sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
       }
       break;
     }
@@ -74665,30 +91537,36 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
       sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
       if( pExpr->op==TK_SELECT ){
         dest.eDest = SRT_Mem;
-        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
+        dest.iSdst = dest.iSDParm;
+        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iSDParm);
         VdbeComment((v, "Init subquery result"));
       }else{
         dest.eDest = SRT_Exists;
-        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
         VdbeComment((v, "Init EXISTS result"));
       }
       sqlite3ExprDelete(pParse->db, pSel->pLimit);
       pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
                                   &sqlite3IntTokens[1]);
       pSel->iLimit = 0;
+      pSel->selFlags &= ~SF_MultiValue;
       if( sqlite3Select(pParse, pSel, &dest) ){
         return 0;
       }
-      rReg = dest.iParm;
-      ExprSetIrreducible(pExpr);
+      rReg = dest.iSDParm;
+      ExprSetVVAProperty(pExpr, EP_NoReduce);
       break;
     }
   }
 
-  if( testAddr>=0 ){
-    sqlite3VdbeJumpHere(v, testAddr);
+  if( rHasNullFlag ){
+    sqlite3SetHasNullFlag(v, pExpr->iTable, rHasNullFlag);
+  }
+
+  if( jmpIfDynamic>=0 ){
+    sqlite3VdbeJumpHere(v, jmpIfDynamic);
   }
-  sqlite3ExprCachePop(pParse, 1);
+  sqlite3ExprCachePop(pParse);
 
   return rReg;
 }
@@ -74707,7 +91585,7 @@ SQLITE_PRIVATE int sqlite3CodeSubselect(
 ** if the LHS is NULL or if the LHS is not contained within the RHS and the
 ** RHS contains one or more NULL values.
 **
-** This routine generates code will jump to destIfFalse if the LHS is not 
+** This routine generates code that jumps to destIfFalse if the LHS is not 
 ** contained within the RHS.  If due to NULLs we cannot determine if the LHS
 ** is contained in the RHS then jump to destIfNull.  If the LHS is contained
 ** within the RHS then fall through.
@@ -74730,7 +91608,9 @@ static void sqlite3ExprCodeIN(
   v = pParse->pVdbe;
   assert( v!=0 );       /* OOM detected prior to this routine */
   VdbeNoopComment((v, "begin IN expr"));
-  eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull);
+  eType = sqlite3FindInIndex(pParse, pExpr,
+                             IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
+                             destIfFalse==destIfNull ? 0 : &rRhsHasNull);
 
   /* Figure out the affinity to use to create a key from the results
   ** of the expression. affinityStr stores a static string suitable for
@@ -74744,101 +91624,121 @@ static void sqlite3ExprCodeIN(
   r1 = sqlite3GetTempReg(pParse);
   sqlite3ExprCode(pParse, pExpr->pLeft, r1);
 
-  /* If the LHS is NULL, then the result is either false or NULL depending
-  ** on whether the RHS is empty or not, respectively.
+  /* If sqlite3FindInIndex() did not find or create an index that is
+  ** suitable for evaluating the IN operator, then evaluate using a
+  ** sequence of comparisons.
   */
-  if( destIfNull==destIfFalse ){
-    /* Shortcut for the common case where the false and NULL outcomes are
-    ** the same. */
-    sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
-  }else{
-    int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
-    sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
-    sqlite3VdbeJumpHere(v, addr1);
-  }
-
-  if( eType==IN_INDEX_ROWID ){
-    /* In this case, the RHS is the ROWID of table b-tree
-    */
-    sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
-    sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
+  if( eType==IN_INDEX_NOOP ){
+    ExprList *pList = pExpr->x.pList;
+    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+    int labelOk = sqlite3VdbeMakeLabel(v);
+    int r2, regToFree;
+    int regCkNull = 0;
+    int ii;
+    assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+    if( destIfNull!=destIfFalse ){
+      regCkNull = sqlite3GetTempReg(pParse);
+      sqlite3VdbeAddOp3(v, OP_BitAnd, r1, r1, regCkNull);
+    }
+    for(ii=0; ii<pList->nExpr; ii++){
+      r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);
+      if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
+        sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
+      }
+      if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
+        sqlite3VdbeAddOp4(v, OP_Eq, r1, labelOk, r2,
+                          (void*)pColl, P4_COLLSEQ);
+        VdbeCoverageIf(v, ii<pList->nExpr-1);
+        VdbeCoverageIf(v, ii==pList->nExpr-1);
+        sqlite3VdbeChangeP5(v, affinity);
+      }else{
+        assert( destIfNull==destIfFalse );
+        sqlite3VdbeAddOp4(v, OP_Ne, r1, destIfFalse, r2,
+                          (void*)pColl, P4_COLLSEQ); VdbeCoverage(v);
+        sqlite3VdbeChangeP5(v, affinity | SQLITE_JUMPIFNULL);
+      }
+      sqlite3ReleaseTempReg(pParse, regToFree);
+    }
+    if( regCkNull ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
+      sqlite3VdbeGoto(v, destIfFalse);
+    }
+    sqlite3VdbeResolveLabel(v, labelOk);
+    sqlite3ReleaseTempReg(pParse, regCkNull);
   }else{
-    /* In this case, the RHS is an index b-tree.
-    */
-    sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
-
-    /* If the set membership test fails, then the result of the 
-    ** "x IN (...)" expression must be either 0 or NULL. If the set
-    ** contains no NULL values, then the result is 0. If the set 
-    ** contains one or more NULL values, then the result of the
-    ** expression is also NULL.
+  
+    /* If the LHS is NULL, then the result is either false or NULL depending
+    ** on whether the RHS is empty or not, respectively.
     */
-    if( rRhsHasNull==0 || destIfFalse==destIfNull ){
-      /* This branch runs if it is known at compile time that the RHS
-      ** cannot contain NULL values. This happens as the result
-      ** of a "NOT NULL" constraint in the database schema.
-      **
-      ** Also run this branch if NULL is equivalent to FALSE
-      ** for this particular IN operator.
+    if( sqlite3ExprCanBeNull(pExpr->pLeft) ){
+      if( destIfNull==destIfFalse ){
+        /* Shortcut for the common case where the false and NULL outcomes are
+        ** the same. */
+        sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull); VdbeCoverage(v);
+      }else{
+        int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1); VdbeCoverage(v);
+        sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
+        VdbeCoverage(v);
+        sqlite3VdbeGoto(v, destIfNull);
+        sqlite3VdbeJumpHere(v, addr1);
+      }
+    }
+  
+    if( eType==IN_INDEX_ROWID ){
+      /* In this case, the RHS is the ROWID of table b-tree
       */
-      sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
-
+      sqlite3VdbeAddOp3(v, OP_SeekRowid, pExpr->iTable, destIfFalse, r1);
+      VdbeCoverage(v);
     }else{
-      /* In this branch, the RHS of the IN might contain a NULL and
-      ** the presence of a NULL on the RHS makes a difference in the
-      ** outcome.
+      /* In this case, the RHS is an index b-tree.
       */
-      int j1, j2, j3;
-
-      /* First check to see if the LHS is contained in the RHS.  If so,
-      ** then the presence of NULLs in the RHS does not matter, so jump
-      ** over all of the code that follows.
-      */
-      j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
-
-      /* Here we begin generating code that runs if the LHS is not
-      ** contained within the RHS.  Generate additional code that
-      ** tests the RHS for NULLs.  If the RHS contains a NULL then
-      ** jump to destIfNull.  If there are no NULLs in the RHS then
-      ** jump to destIfFalse.
-      */
-      j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull);
-      j3 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, rRhsHasNull, 1);
-      sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull);
-      sqlite3VdbeJumpHere(v, j3);
-      sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1);
-      sqlite3VdbeJumpHere(v, j2);
-
-      /* Jump to the appropriate target depending on whether or not
-      ** the RHS contains a NULL
-      */
-      sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
-
-      /* The OP_Found at the top of this branch jumps here when true, 
-      ** causing the overall IN expression evaluation to fall through.
+      sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
+  
+      /* If the set membership test fails, then the result of the 
+      ** "x IN (...)" expression must be either 0 or NULL. If the set
+      ** contains no NULL values, then the result is 0. If the set 
+      ** contains one or more NULL values, then the result of the
+      ** expression is also NULL.
       */
-      sqlite3VdbeJumpHere(v, j1);
+      assert( destIfFalse!=destIfNull || rRhsHasNull==0 );
+      if( rRhsHasNull==0 ){
+        /* This branch runs if it is known at compile time that the RHS
+        ** cannot contain NULL values. This happens as the result
+        ** of a "NOT NULL" constraint in the database schema.
+        **
+        ** Also run this branch if NULL is equivalent to FALSE
+        ** for this particular IN operator.
+        */
+        sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
+        VdbeCoverage(v);
+      }else{
+        /* In this branch, the RHS of the IN might contain a NULL and
+        ** the presence of a NULL on the RHS makes a difference in the
+        ** outcome.
+        */
+        int addr1;
+  
+        /* First check to see if the LHS is contained in the RHS.  If so,
+        ** then the answer is TRUE the presence of NULLs in the RHS does
+        ** not matter.  If the LHS is not contained in the RHS, then the
+        ** answer is NULL if the RHS contains NULLs and the answer is
+        ** FALSE if the RHS is NULL-free.
+        */
+        addr1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
+        VdbeCoverage(v);
+        sqlite3VdbeAddOp2(v, OP_IsNull, rRhsHasNull, destIfNull);
+        VdbeCoverage(v);
+        sqlite3VdbeGoto(v, destIfFalse);
+        sqlite3VdbeJumpHere(v, addr1);
+      }
     }
   }
   sqlite3ReleaseTempReg(pParse, r1);
-  sqlite3ExprCachePop(pParse, 1);
+  sqlite3ExprCachePop(pParse);
   VdbeComment((v, "end IN expr"));
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
-/*
-** Duplicate an 8-byte value
-*/
-static char *dup8bytes(Vdbe *v, const char *in){
-  char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
-  if( out ){
-    memcpy(out, in, 8);
-  }
-  return out;
-}
-
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Generate an instruction that will put the floating point
@@ -74851,12 +91751,10 @@ static char *dup8bytes(Vdbe *v, const char *in){
 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
   if( ALWAYS(z!=0) ){
     double value;
-    char *zV;
     sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
     assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
     if( negateFlag ) value = -value;
-    zV = dup8bytes(v, (char*)&value);
-    sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
+    sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
   }
 }
 #endif
@@ -74880,22 +91778,40 @@ static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
     i64 value;
     const char *z = pExpr->u.zToken;
     assert( z!=0 );
-    c = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
+    c = sqlite3DecOrHexToI64(z, &value);
     if( c==0 || (c==2 && negFlag) ){
-      char *zV;
       if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
-      zV = dup8bytes(v, (char*)&value);
-      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
+      sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
     }else{
 #ifdef SQLITE_OMIT_FLOATING_POINT
       sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
 #else
-      codeReal(v, z, negFlag, iMem);
+#ifndef SQLITE_OMIT_HEX_INTEGER
+      if( sqlite3_strnicmp(z,"0x",2)==0 ){
+        sqlite3ErrorMsg(pParse, "hex literal too big: %s", z);
+      }else
+#endif
+      {
+        codeReal(v, z, negFlag, iMem);
+      }
 #endif
     }
   }
 }
 
+#if defined(SQLITE_DEBUG)
+/*
+** Verify the consistency of the column cache
+*/
+static int cacheIsValid(Parse *pParse){
+  int i, n;
+  for(i=n=0; i<SQLITE_N_COLCACHE; i++){
+    if( pParse->aColCache[i].iReg>0 ) n++;
+  }
+  return n==pParse->nColCache;
+}
+#endif
+
 /*
 ** Clear a cache entry.
 */
@@ -74906,6 +91822,9 @@ static void cacheEntryClear(Parse *pParse, struct yColCache *p){
     }
     p->tempReg = 0;
   }
+  p->iReg = 0;
+  pParse->nColCache--;
+  assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
 }
 
 
@@ -74919,14 +91838,15 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
   int idxLru;
   struct yColCache *p;
 
-  assert( iReg>0 );  /* Register numbers are always positive */
+  /* Unless an error has occurred, register numbers are always positive. */
+  assert( iReg>0 || pParse->nErr || pParse->db->mallocFailed );
   assert( iCol>=-1 && iCol<32768 );  /* Finite column numbers */
 
   /* The SQLITE_ColumnCache flag disables the column cache.  This is used
   ** for testing only - to verify that SQLite always gets the same answer
   ** with and without the column cache.
   */
-  if( pParse->db->flags & SQLITE_ColumnCache ) return;
+  if( OptimizationDisabled(pParse->db, SQLITE_ColumnCache) ) return;
 
   /* First replace any existing entry.
   **
@@ -74935,15 +91855,6 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
   */
 #ifndef NDEBUG
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-#if 0 /* This code wold remove the entry from the cache if it existed */
-    if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){
-      cacheEntryClear(pParse, p);
-      p->iLevel = pParse->iCacheLevel;
-      p->iReg = iReg;
-      p->lru = pParse->iCacheCnt++;
-      return;
-    }
-#endif
     assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
   }
 #endif
@@ -74957,6 +91868,8 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
       p->iReg = iReg;
       p->tempReg = 0;
       p->lru = pParse->iCacheCnt++;
+      pParse->nColCache++;
+      assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
       return;
     }
   }
@@ -74978,6 +91891,7 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
     p->iReg = iReg;
     p->tempReg = 0;
     p->lru = pParse->iCacheCnt++;
+    assert( cacheIsValid(pParse) );
     return;
   }
 }
@@ -74987,15 +91901,13 @@ SQLITE_PRIVATE void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int
 ** Purge the range of registers from the column cache.
 */
 SQLITE_PRIVATE void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
-  int i;
-  int iLast = iReg + nReg - 1;
   struct yColCache *p;
-  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-    int r = p->iReg;
-    if( r>=iReg && r<=iLast ){
-      cacheEntryClear(pParse, p);
-      p->iReg = 0;
-    }
+  if( iReg<=0 || pParse->nColCache==0 ) return;
+  p = &pParse->aColCache[SQLITE_N_COLCACHE-1];
+  while(1){
+    if( p->iReg >= iReg && p->iReg < iReg+nReg ) cacheEntryClear(pParse, p);
+    if( p==pParse->aColCache ) break;
+    p--;
   }
 }
 
@@ -75006,23 +91918,31 @@ SQLITE_PRIVATE void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
 */
 SQLITE_PRIVATE void sqlite3ExprCachePush(Parse *pParse){
   pParse->iCacheLevel++;
+#ifdef SQLITE_DEBUG
+  if( pParse->db->flags & SQLITE_VdbeAddopTrace ){
+    printf("PUSH to %d\n", pParse->iCacheLevel);
+  }
+#endif
 }
 
 /*
 ** Remove from the column cache any entries that were added since the
-** the previous N Push operations.  In other words, restore the cache
-** to the state it was in N Pushes ago.
+** the previous sqlite3ExprCachePush operation.  In other words, restore
+** the cache to the state it was in prior the most recent Push.
 */
-SQLITE_PRIVATE void sqlite3ExprCachePop(Parse *pParse, int N){
+SQLITE_PRIVATE void sqlite3ExprCachePop(Parse *pParse){
   int i;
   struct yColCache *p;
-  assert( N>0 );
-  assert( pParse->iCacheLevel>=N );
-  pParse->iCacheLevel -= N;
+  assert( pParse->iCacheLevel>=1 );
+  pParse->iCacheLevel--;
+#ifdef SQLITE_DEBUG
+  if( pParse->db->flags & SQLITE_VdbeAddopTrace ){
+    printf("POP  to %d\n", pParse->iCacheLevel);
+  }
+#endif
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     if( p->iReg && p->iLevel>pParse->iCacheLevel ){
       cacheEntryClear(pParse, p);
-      p->iReg = 0;
     }
   }
 }
@@ -75043,21 +91963,47 @@ static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
   }
 }
 
+/* Generate code that will load into register regOut a value that is
+** appropriate for the iIdxCol-th column of index pIdx.
+*/
+SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(
+  Parse *pParse,  /* The parsing context */
+  Index *pIdx,    /* The index whose column is to be loaded */
+  int iTabCur,    /* Cursor pointing to a table row */
+  int iIdxCol,    /* The column of the index to be loaded */
+  int regOut      /* Store the index column value in this register */
+){
+  i16 iTabCol = pIdx->aiColumn[iIdxCol];
+  if( iTabCol==XN_EXPR ){
+    assert( pIdx->aColExpr );
+    assert( pIdx->aColExpr->nExpr>iIdxCol );
+    pParse->iSelfTab = iTabCur;
+    sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
+  }else{
+    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
+                                    iTabCol, regOut);
+  }
+}
+
 /*
 ** Generate code to extract the value of the iCol-th column of a table.
 */
 SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
   Vdbe *v,        /* The VDBE under construction */
   Table *pTab,    /* The table containing the value */
-  int iTabCur,    /* The cursor for this table */
+  int iTabCur,    /* The table cursor.  Or the PK cursor for WITHOUT ROWID */
   int iCol,       /* Index of the column to extract */
-  int regOut      /* Extract the valud into this register */
+  int regOut      /* Extract the value into this register */
 ){
   if( iCol<0 || iCol==pTab->iPKey ){
     sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
   }else{
     int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
-    sqlite3VdbeAddOp3(v, op, iTabCur, iCol, regOut);
+    int x = iCol;
+    if( !HasRowid(pTab) && !IsVirtual(pTab) ){
+      x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
+    }
+    sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);
   }
   if( iCol>=0 ){
     sqlite3ColumnDefault(v, pTab, iCol, regOut);
@@ -75066,9 +92012,12 @@ SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
 
 /*
 ** Generate code that will extract the iColumn-th column from
-** table pTab and store the column value in a register.  An effort
-** is made to store the column value in register iReg, but this is
-** not guaranteed.  The location of the column value is returned.
+** table pTab and store the column value in a register. 
+**
+** An effort is made to store the column value in register iReg.  This
+** is not garanteeed for GetColumn() - the result can be stored in
+** any register.  But the result is guaranteed to land in register iReg
+** for GetColumnToReg().
 **
 ** There must be an open cursor to pTab in iTable when this routine
 ** is called.  If iColumn<0 then code is generated that extracts the rowid.
@@ -75078,7 +92027,8 @@ SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(
   Table *pTab,     /* Description of the table we are reading from */
   int iColumn,     /* Index of the table column */
   int iTable,      /* The cursor pointing to the table */
-  int iReg         /* Store results here */
+  int iReg,        /* Store results here */
+  u8 p5            /* P5 value for OP_Column + FLAGS */
 ){
   Vdbe *v = pParse->pVdbe;
   int i;
@@ -75093,9 +92043,24 @@ SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(
   }  
   assert( v!=0 );
   sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);
-  sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
+  if( p5 ){
+    sqlite3VdbeChangeP5(v, p5);
+  }else{   
+    sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
+  }
   return iReg;
 }
+SQLITE_PRIVATE void sqlite3ExprCodeGetColumnToReg(
+  Parse *pParse,   /* Parsing and code generating context */
+  Table *pTab,     /* Description of the table we are reading from */
+  int iColumn,     /* Index of the table column */
+  int iTable,      /* The cursor pointing to the table */
+  int iReg         /* Store results here */
+){
+  int r1 = sqlite3ExprCodeGetColumn(pParse, pTab, iColumn, iTable, iReg, 0);
+  if( r1!=iReg ) sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, r1, iReg);
+}
+
 
 /*
 ** Clear all column cache entries.
@@ -75104,10 +92069,14 @@ SQLITE_PRIVATE void sqlite3ExprCacheClear(Parse *pParse){
   int i;
   struct yColCache *p;
 
+#if SQLITE_DEBUG
+  if( pParse->db->flags & SQLITE_VdbeAddopTrace ){
+    printf("CLEAR\n");
+  }
+#endif
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     if( p->iReg ){
       cacheEntryClear(pParse, p);
-      p->iReg = 0;
     }
   }
 }
@@ -75125,28 +92094,9 @@ SQLITE_PRIVATE void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, in
 ** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
 */
 SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
-  int i;
-  struct yColCache *p;
-  if( NEVER(iFrom==iTo) ) return;
+  assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo );
   sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
-  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-    int x = p->iReg;
-    if( x>=iFrom && x<iFrom+nReg ){
-      p->iReg += iTo-iFrom;
-    }
-  }
-}
-
-/*
-** Generate code to copy content from registers iFrom...iFrom+nReg-1
-** over to iTo..iTo+nReg-1.
-*/
-SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
-  int i;
-  if( NEVER(iFrom==iTo) ) return;
-  for(i=0; i<nReg; i++){
-    sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
-  }
+  sqlite3ExprCacheRemove(pParse, iFrom, nReg);
 }
 
 #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
@@ -75168,6 +92118,17 @@ static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
 }
 #endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
 
+
+/*
+** Convert an expression node to a TK_REGISTER
+*/
+static void exprToRegister(Expr *p, int iReg){
+  p->op2 = p->op;
+  p->op = TK_REGISTER;
+  p->iTable = iReg;
+  ExprClearProperty(p, EP_Skip);
+}
+
 /*
 ** Generate code into the current Vdbe to evaluate the given
 ** expression.  Attempt to store the results in register "target".
@@ -75187,6 +92148,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
   int regFree2 = 0;         /* If non-zero free this temporary register */
   int r1, r2, r3, r4;       /* Various register numbers */
   sqlite3 *db = pParse->db; /* The database connection */
+  Expr tempX;               /* Temporary expression node */
 
   assert( target>0 && target<=pParse->nMem );
   if( v==0 ){
@@ -75215,14 +92177,21 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       /* Otherwise, fall thru into the TK_COLUMN case */
     }
     case TK_COLUMN: {
-      if( pExpr->iTable<0 ){
-        /* This only happens when coding check constraints */
-        assert( pParse->ckBase>0 );
-        inReg = pExpr->iColumn + pParse->ckBase;
-      }else{
-        inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
-                                 pExpr->iColumn, pExpr->iTable, target);
+      int iTab = pExpr->iTable;
+      if( iTab<0 ){
+        if( pParse->ckBase>0 ){
+          /* Generating CHECK constraints or inserting into partial index */
+          inReg = pExpr->iColumn + pParse->ckBase;
+          break;
+        }else{
+          /* Coding an expression that is part of an index where column names
+          ** in the index refer to the table to which the index belongs */
+          iTab = pParse->iSelfTab;
+        }
       }
+      inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
+                               pExpr->iColumn, iTab, target,
+                               pExpr->op2);
       break;
     }
     case TK_INTEGER: {
@@ -75238,7 +92207,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
 #endif
     case TK_STRING: {
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
-      sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0);
+      sqlite3VdbeLoadString(v, target, pExpr->u.zToken);
       break;
     }
     case TK_NULL: {
@@ -75277,33 +92246,16 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       inReg = pExpr->iTable;
       break;
     }
-    case TK_AS: {
-      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
-      break;
-    }
 #ifndef SQLITE_OMIT_CAST
     case TK_CAST: {
       /* Expressions of the form:   CAST(pLeft AS token) */
-      int aff, to_op;
       inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
-      assert( !ExprHasProperty(pExpr, EP_IntValue) );
-      aff = sqlite3AffinityType(pExpr->u.zToken);
-      to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
-      assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
-      assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
-      assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
-      assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
-      assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
-      testcase( to_op==OP_ToText );
-      testcase( to_op==OP_ToBlob );
-      testcase( to_op==OP_ToNumeric );
-      testcase( to_op==OP_ToInt );
-      testcase( to_op==OP_ToReal );
       if( inReg!=target ){
         sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
         inReg = target;
       }
-      sqlite3VdbeAddOp1(v, to_op, inReg);
+      sqlite3VdbeAddOp2(v, OP_Cast, target,
+                        sqlite3AffinityType(pExpr->u.zToken, 0));
       testcase( usedAsColumnCache(pParse, inReg, inReg) );
       sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
       break;
@@ -75315,22 +92267,16 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
-      assert( TK_LT==OP_Lt );
-      assert( TK_LE==OP_Le );
-      assert( TK_GT==OP_Gt );
-      assert( TK_GE==OP_Ge );
-      assert( TK_EQ==OP_Eq );
-      assert( TK_NE==OP_Ne );
-      testcase( op==TK_LT );
-      testcase( op==TK_LE );
-      testcase( op==TK_GT );
-      testcase( op==TK_GE );
-      testcase( op==TK_EQ );
-      testcase( op==TK_NE );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, inReg, SQLITE_STOREP2);
+      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
+      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
+      assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
+      assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
+      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
+      assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
@@ -75344,6 +92290,8 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       op = (op==TK_IS) ? TK_EQ : TK_NE;
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==TK_EQ);
+      VdbeCoverageIf(v, op==TK_NE);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
@@ -75360,28 +92308,17 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     case TK_LSHIFT:
     case TK_RSHIFT: 
     case TK_CONCAT: {
-      assert( TK_AND==OP_And );
-      assert( TK_OR==OP_Or );
-      assert( TK_PLUS==OP_Add );
-      assert( TK_MINUS==OP_Subtract );
-      assert( TK_REM==OP_Remainder );
-      assert( TK_BITAND==OP_BitAnd );
-      assert( TK_BITOR==OP_BitOr );
-      assert( TK_SLASH==OP_Divide );
-      assert( TK_LSHIFT==OP_ShiftLeft );
-      assert( TK_RSHIFT==OP_ShiftRight );
-      assert( TK_CONCAT==OP_Concat );
-      testcase( op==TK_AND );
-      testcase( op==TK_OR );
-      testcase( op==TK_PLUS );
-      testcase( op==TK_MINUS );
-      testcase( op==TK_REM );
-      testcase( op==TK_BITAND );
-      testcase( op==TK_BITOR );
-      testcase( op==TK_SLASH );
-      testcase( op==TK_LSHIFT );
-      testcase( op==TK_RSHIFT );
-      testcase( op==TK_CONCAT );
+      assert( TK_AND==OP_And );            testcase( op==TK_AND );
+      assert( TK_OR==OP_Or );              testcase( op==TK_OR );
+      assert( TK_PLUS==OP_Add );           testcase( op==TK_PLUS );
+      assert( TK_MINUS==OP_Subtract );     testcase( op==TK_MINUS );
+      assert( TK_REM==OP_Remainder );      testcase( op==TK_REM );
+      assert( TK_BITAND==OP_BitAnd );      testcase( op==TK_BITAND );
+      assert( TK_BITOR==OP_BitOr );        testcase( op==TK_BITOR );
+      assert( TK_SLASH==OP_Divide );       testcase( op==TK_SLASH );
+      assert( TK_LSHIFT==OP_ShiftLeft );   testcase( op==TK_LSHIFT );
+      assert( TK_RSHIFT==OP_ShiftRight );  testcase( op==TK_RSHIFT );
+      assert( TK_CONCAT==OP_Concat );      testcase( op==TK_CONCAT );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       sqlite3VdbeAddOp3(v, op, r2, r1, target);
@@ -75400,8 +92337,10 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         codeReal(v, pLeft->u.zToken, 1, target);
 #endif
       }else{
-        regFree1 = r1 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
+        tempX.op = TK_INTEGER;
+        tempX.flags = EP_IntValue|EP_TokenOnly;
+        tempX.u.iValue = 0;
+        r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);
         r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
         sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
         testcase( regFree2==0 );
@@ -75411,10 +92350,8 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     }
     case TK_BITNOT:
     case TK_NOT: {
-      assert( TK_BITNOT==OP_BitNot );
-      assert( TK_NOT==OP_Not );
-      testcase( op==TK_BITNOT );
-      testcase( op==TK_NOT );
+      assert( TK_BITNOT==OP_BitNot );   testcase( op==TK_BITNOT );
+      assert( TK_NOT==OP_Not );         testcase( op==TK_NOT );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       testcase( regFree1==0 );
       inReg = target;
@@ -75424,15 +92361,15 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     case TK_ISNULL:
     case TK_NOTNULL: {
       int addr;
-      assert( TK_ISNULL==OP_IsNull );
-      assert( TK_NOTNULL==OP_NotNull );
-      testcase( op==TK_ISNULL );
-      testcase( op==TK_NOTNULL );
+      assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );
+      assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
       sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       testcase( regFree1==0 );
       addr = sqlite3VdbeAddOp1(v, op, r1);
-      sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
+      VdbeCoverageIf(v, op==TK_ISNULL);
+      VdbeCoverageIf(v, op==TK_NOTNULL);
+      sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
       sqlite3VdbeJumpHere(v, addr);
       break;
     }
@@ -75446,22 +92383,18 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       }
       break;
     }
-    case TK_CONST_FUNC:
     case TK_FUNCTION: {
       ExprList *pFarg;       /* List of function arguments */
       int nFarg;             /* Number of function arguments */
       FuncDef *pDef;         /* The function definition object */
-      int nId;               /* Length of the function name in bytes */
       const char *zId;       /* The function name */
-      int constMask = 0;     /* Mask of function arguments that are constant */
+      u32 constMask = 0;     /* Mask of function arguments that are constant */
       int i;                 /* Loop counter */
       u8 enc = ENC(db);      /* The text encoding used by this database */
       CollSeq *pColl = 0;    /* A collating sequence */
 
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-      testcase( op==TK_CONST_FUNC );
-      testcase( op==TK_FUNCTION );
-      if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
+      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
         pFarg = 0;
       }else{
         pFarg = pExpr->x.pList;
@@ -75469,38 +92402,86 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       nFarg = pFarg ? pFarg->nExpr : 0;
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
       zId = pExpr->u.zToken;
-      nId = sqlite3Strlen30(zId);
-      pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
-      if( pDef==0 ){
-        sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
+      pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+      if( pDef==0 && pParse->explain ){
+        pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
+      }
+#endif
+      if( pDef==0 || pDef->xFinalize!=0 ){
+        sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);
         break;
       }
 
       /* Attempt a direct implementation of the built-in COALESCE() and
-      ** IFNULL() functions.  This avoids unnecessary evalation of
+      ** IFNULL() functions.  This avoids unnecessary evaluation of
       ** arguments past the first non-NULL argument.
       */
-      if( pDef->flags & SQLITE_FUNC_COALESCE ){
+      if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
         int endCoalesce = sqlite3VdbeMakeLabel(v);
         assert( nFarg>=2 );
         sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
         for(i=1; i<nFarg; i++){
           sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
+          VdbeCoverage(v);
           sqlite3ExprCacheRemove(pParse, target, 1);
           sqlite3ExprCachePush(pParse);
           sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
-          sqlite3ExprCachePop(pParse, 1);
+          sqlite3ExprCachePop(pParse);
         }
         sqlite3VdbeResolveLabel(v, endCoalesce);
         break;
       }
 
+      /* The UNLIKELY() function is a no-op.  The result is the value
+      ** of the first argument.
+      */
+      if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
+        assert( nFarg>=1 );
+        inReg = sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);
+        break;
+      }
 
+      for(i=0; i<nFarg; i++){
+        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
+          testcase( i==31 );
+          constMask |= MASKBIT32(i);
+        }
+        if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
+          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
+        }
+      }
       if( pFarg ){
-        r1 = sqlite3GetTempRange(pParse, nFarg);
+        if( constMask ){
+          r1 = pParse->nMem+1;
+          pParse->nMem += nFarg;
+        }else{
+          r1 = sqlite3GetTempRange(pParse, nFarg);
+        }
+
+        /* For length() and typeof() functions with a column argument,
+        ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
+        ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
+        ** loading.
+        */
+        if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
+          u8 exprOp;
+          assert( nFarg==1 );
+          assert( pFarg->a[0].pExpr!=0 );
+          exprOp = pFarg->a[0].pExpr->op;
+          if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
+            assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
+            assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
+            testcase( pDef->funcFlags & OPFLAG_LENGTHARG );
+            pFarg->a[0].pExpr->op2 = 
+                  pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);
+          }
+        }
+
         sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
-        sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
-        sqlite3ExprCachePop(pParse, 1);   /* Ticket 2ea2425d34be */
+        sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,
+                                SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
+        sqlite3ExprCachePop(pParse);      /* Ticket 2ea2425d34be */
       }else{
         r1 = 0;
       }
@@ -75523,22 +92504,14 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
       }
 #endif
-      for(i=0; i<nFarg; i++){
-        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
-          constMask |= (1<<i);
-        }
-        if( (pDef->flags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
-          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
-        }
-      }
-      if( pDef->flags & SQLITE_FUNC_NEEDCOLL ){
+      if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
         if( !pColl ) pColl = db->pDfltColl; 
         sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
       }
-      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
+      sqlite3VdbeAddOp4(v, OP_Function0, constMask, r1, target,
                         (char*)pDef, P4_FUNCDEF);
       sqlite3VdbeChangeP5(v, (u8)nFarg);
-      if( nFarg ){
+      if( nFarg && constMask==0 ){
         sqlite3ReleaseTempRange(pParse, r1, nFarg);
       }
       break;
@@ -75588,18 +92561,21 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       r3 = sqlite3GetTempReg(pParse);
       r4 = sqlite3GetTempReg(pParse);
       codeCompare(pParse, pLeft, pRight, OP_Ge,
-                  r1, r2, r3, SQLITE_STOREP2);
+                  r1, r2, r3, SQLITE_STOREP2);  VdbeCoverage(v);
       pLItem++;
       pRight = pLItem->pExpr;
       sqlite3ReleaseTempReg(pParse, regFree2);
       r2 = sqlite3ExprCodeTemp(pParse, pRight, &regFree2);
       testcase( regFree2==0 );
       codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
+      VdbeCoverage(v);
       sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
       sqlite3ReleaseTempReg(pParse, r3);
       sqlite3ReleaseTempReg(pParse, r4);
       break;
     }
+    case TK_SPAN:
+    case TK_COLLATE: 
     case TK_UPLUS: {
       inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
       break;
@@ -75648,7 +92624,10 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
 
 #ifndef SQLITE_OMIT_FLOATING_POINT
       /* If the column has REAL affinity, it may currently be stored as an
-      ** integer. Use OP_RealAffinity to make sure it is really real.  */
+      ** integer. Use OP_RealAffinity to make sure it is really real.
+      **
+      ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
+      ** floating point when extracting it from the record.  */
       if( pExpr->iColumn>=0 
        && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
       ){
@@ -75671,9 +92650,9 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
     **        WHEN x=eN THEN rN ELSE y END
     **
     ** X (if it exists) is in pExpr->pLeft.
-    ** Y is in pExpr->pRight.  The Y is also optional.  If there is no
-    ** ELSE clause and no other term matches, then the result of the
-    ** exprssion is NULL.
+    ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
+    ** odd.  The Y is also optional.  If the number of elements in x.pList
+    ** is even, then Y is omitted and the "otherwise" result is NULL.
     ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
     **
     ** The result of the expression is the Ri for the first matching Ei,
@@ -75688,27 +92667,23 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       ExprList *pEList;                 /* List of WHEN terms */
       struct ExprList_item *aListelem;  /* Array of WHEN terms */
       Expr opCompare;                   /* The X==Ei expression */
-      Expr cacheX;                      /* Cached expression X */
       Expr *pX;                         /* The X expression */
       Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */
       VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )
 
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
-      assert((pExpr->x.pList->nExpr % 2) == 0);
       assert(pExpr->x.pList->nExpr > 0);
       pEList = pExpr->x.pList;
       aListelem = pEList->a;
       nExpr = pEList->nExpr;
       endLabel = sqlite3VdbeMakeLabel(v);
       if( (pX = pExpr->pLeft)!=0 ){
-        cacheX = *pX;
+        tempX = *pX;
         testcase( pX->op==TK_COLUMN );
-        testcase( pX->op==TK_REGISTER );
-        cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, &regFree1);
+        exprToRegister(&tempX, sqlite3ExprCodeTemp(pParse, pX, &regFree1));
         testcase( regFree1==0 );
-        cacheX.op = TK_REGISTER;
         opCompare.op = TK_EQ;
-        opCompare.pLeft = &cacheX;
+        opCompare.pLeft = &tempX;
         pTest = &opCompare;
         /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
         ** The value in regFree1 might get SCopy-ed into the file result.
@@ -75716,7 +92691,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         ** purposes and possibly overwritten.  */
         regFree1 = 0;
       }
-      for(i=0; i<nExpr; i=i+2){
+      for(i=0; i<nExpr-1; i=i+2){
         sqlite3ExprCachePush(pParse);
         if( pX ){
           assert( pTest!=0 );
@@ -75728,16 +92703,15 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
         testcase( pTest->op==TK_COLUMN );
         sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
         testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
-        testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
         sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
-        sqlite3ExprCachePop(pParse, 1);
+        sqlite3VdbeGoto(v, endLabel);
+        sqlite3ExprCachePop(pParse);
         sqlite3VdbeResolveLabel(v, nextCase);
       }
-      if( pExpr->pRight ){
+      if( (nExpr&1)!=0 ){
         sqlite3ExprCachePush(pParse);
-        sqlite3ExprCode(pParse, pExpr->pRight, target);
-        sqlite3ExprCachePop(pParse, 1);
+        sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
+        sqlite3ExprCachePop(pParse);
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, target);
       }
@@ -75765,8 +92739,10 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
       if( pExpr->affinity==OE_Ignore ){
         sqlite3VdbeAddOp4(
             v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
+        VdbeCoverage(v);
       }else{
-        sqlite3HaltConstraint(pParse, pExpr->affinity, pExpr->u.zToken, 0);
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,
+                              pExpr->affinity, pExpr->u.zToken, 0, 0);
       }
 
       break;
@@ -75779,6 +92755,28 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
 }
 
 /*
+** Factor out the code of the given expression to initialization time.
+*/
+SQLITE_PRIVATE void sqlite3ExprCodeAtInit(
+  Parse *pParse,    /* Parsing context */
+  Expr *pExpr,      /* The expression to code when the VDBE initializes */
+  int regDest,      /* Store the value in this register */
+  u8 reusable       /* True if this expression is reusable */
+){
+  ExprList *p;
+  assert( ConstFactorOk(pParse) );
+  p = pParse->pConstExpr;
+  pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
+  p = sqlite3ExprListAppend(pParse, p, pExpr);
+  if( p ){
+     struct ExprList_item *pItem = &p->a[p->nExpr-1];
+     pItem->u.iConstExprReg = regDest;
+     pItem->reusable = reusable;
+  }
+  pParse->pConstExpr = p;
+}
+
+/*
 ** Generate code to evaluate an expression and store the results
 ** into a register.  Return the register number where the results
 ** are stored.
@@ -75786,15 +92784,40 @@ SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target)
 ** If the register is a temporary register that can be deallocated,
 ** then write its number into *pReg.  If the result register is not
 ** a temporary, then set *pReg to zero.
+**
+** If pExpr is a constant, then this routine might generate this
+** code to fill the register in the initialization section of the
+** VDBE program, in order to factor it out of the evaluation loop.
 */
 SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
-  int r1 = sqlite3GetTempReg(pParse);
-  int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
-  if( r2==r1 ){
-    *pReg = r1;
+  int r2;
+  pExpr = sqlite3ExprSkipCollate(pExpr);
+  if( ConstFactorOk(pParse)
+   && pExpr->op!=TK_REGISTER
+   && sqlite3ExprIsConstantNotJoin(pExpr)
+  ){
+    ExprList *p = pParse->pConstExpr;
+    int i;
+    *pReg  = 0;
+    if( p ){
+      struct ExprList_item *pItem;
+      for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
+        if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
+          return pItem->u.iConstExprReg;
+        }
+      }
+    }
+    r2 = ++pParse->nMem;
+    sqlite3ExprCodeAtInit(pParse, pExpr, r2, 1);
   }else{
-    sqlite3ReleaseTempReg(pParse, r1);
-    *pReg = 0;
+    int r1 = sqlite3GetTempReg(pParse);
+    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
+    if( r2==r1 ){
+      *pReg = r1;
+    }else{
+      sqlite3ReleaseTempReg(pParse, r1);
+      *pReg = 0;
+    }
   }
   return r2;
 }
@@ -75804,7 +92827,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
 ** results in register target.  The results are guaranteed to appear
 ** in register target.
 */
-SQLITE_PRIVATE int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
+SQLITE_PRIVATE void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
   int inReg;
 
   assert( target>0 && target<=pParse->nMem );
@@ -75812,203 +92835,115 @@ SQLITE_PRIVATE int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
     sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
   }else{
     inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
-    assert( pParse->pVdbe || pParse->db->mallocFailed );
+    assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
     if( inReg!=target && pParse->pVdbe ){
       sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
     }
   }
-  return target;
-}
-
-/*
-** Generate code that evalutes the given expression and puts the result
-** in register target.
-**
-** Also make a copy of the expression results into another "cache" register
-** and modify the expression so that the next time it is evaluated,
-** the result is a copy of the cache register.
-**
-** This routine is used for expressions that are used multiple 
-** times.  They are evaluated once and the results of the expression
-** are reused.
-*/
-SQLITE_PRIVATE int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
-  Vdbe *v = pParse->pVdbe;
-  int inReg;
-  inReg = sqlite3ExprCode(pParse, pExpr, target);
-  assert( target>0 );
-  /* This routine is called for terms to INSERT or UPDATE.  And the only
-  ** other place where expressions can be converted into TK_REGISTER is
-  ** in WHERE clause processing.  So as currently implemented, there is
-  ** no way for a TK_REGISTER to exist here.  But it seems prudent to
-  ** keep the ALWAYS() in case the conditions above change with future
-  ** modifications or enhancements. */
-  if( ALWAYS(pExpr->op!=TK_REGISTER) ){  
-    int iMem;
-    iMem = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
-    pExpr->iTable = iMem;
-    pExpr->op2 = pExpr->op;
-    pExpr->op = TK_REGISTER;
-  }
-  return inReg;
 }
 
 /*
-** Return TRUE if pExpr is an constant expression that is appropriate
-** for factoring out of a loop.  Appropriate expressions are:
-**
-**    *  Any expression that evaluates to two or more opcodes.
-**
-**    *  Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null, 
-**       or OP_Variable that does not need to be placed in a 
-**       specific register.
-**
-** There is no point in factoring out single-instruction constant
-** expressions that need to be placed in a particular register.  
-** We could factor them out, but then we would end up adding an
-** OP_SCopy instruction to move the value into the correct register
-** later.  We might as well just use the original instruction and
-** avoid the OP_SCopy.
+** Make a transient copy of expression pExpr and then code it using
+** sqlite3ExprCode().  This routine works just like sqlite3ExprCode()
+** except that the input expression is guaranteed to be unchanged.
 */
-static int isAppropriateForFactoring(Expr *p){
-  if( !sqlite3ExprIsConstantNotJoin(p) ){
-    return 0;  /* Only constant expressions are appropriate for factoring */
-  }
-  if( (p->flags & EP_FixedDest)==0 ){
-    return 1;  /* Any constant without a fixed destination is appropriate */
-  }
-  while( p->op==TK_UPLUS ) p = p->pLeft;
-  switch( p->op ){
-#ifndef SQLITE_OMIT_BLOB_LITERAL
-    case TK_BLOB:
-#endif
-    case TK_VARIABLE:
-    case TK_INTEGER:
-    case TK_FLOAT:
-    case TK_NULL:
-    case TK_STRING: {
-      testcase( p->op==TK_BLOB );
-      testcase( p->op==TK_VARIABLE );
-      testcase( p->op==TK_INTEGER );
-      testcase( p->op==TK_FLOAT );
-      testcase( p->op==TK_NULL );
-      testcase( p->op==TK_STRING );
-      /* Single-instruction constants with a fixed destination are
-      ** better done in-line.  If we factor them, they will just end
-      ** up generating an OP_SCopy to move the value to the destination
-      ** register. */
-      return 0;
-    }
-    case TK_UMINUS: {
-      if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
-        return 0;
-      }
-      break;
-    }
-    default: {
-      break;
-    }
-  }
-  return 1;
+SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
+  sqlite3 *db = pParse->db;
+  pExpr = sqlite3ExprDup(db, pExpr, 0);
+  if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);
+  sqlite3ExprDelete(db, pExpr);
 }
 
 /*
-** If pExpr is a constant expression that is appropriate for
-** factoring out of a loop, then evaluate the expression
-** into a register and convert the expression into a TK_REGISTER
-** expression.
+** Generate code that will evaluate expression pExpr and store the
+** results in register target.  The results are guaranteed to appear
+** in register target.  If the expression is constant, then this routine
+** might choose to code the expression at initialization time.
 */
-static int evalConstExpr(Walker *pWalker, Expr *pExpr){
-  Parse *pParse = pWalker->pParse;
-  switch( pExpr->op ){
-    case TK_IN:
-    case TK_REGISTER: {
-      return WRC_Prune;
-    }
-    case TK_FUNCTION:
-    case TK_AGG_FUNCTION:
-    case TK_CONST_FUNC: {
-      /* The arguments to a function have a fixed destination.
-      ** Mark them this way to avoid generated unneeded OP_SCopy
-      ** instructions. 
-      */
-      ExprList *pList = pExpr->x.pList;
-      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-      if( pList ){
-        int i = pList->nExpr;
-        struct ExprList_item *pItem = pList->a;
-        for(; i>0; i--, pItem++){
-          if( ALWAYS(pItem->pExpr) ) pItem->pExpr->flags |= EP_FixedDest;
-        }
-      }
-      break;
-    }
-  }
-  if( isAppropriateForFactoring(pExpr) ){
-    int r1 = ++pParse->nMem;
-    int r2;
-    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
-    if( NEVER(r1!=r2) ) sqlite3ReleaseTempReg(pParse, r1);
-    pExpr->op2 = pExpr->op;
-    pExpr->op = TK_REGISTER;
-    pExpr->iTable = r2;
-    return WRC_Prune;
+SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
+  if( pParse->okConstFactor && sqlite3ExprIsConstant(pExpr) ){
+    sqlite3ExprCodeAtInit(pParse, pExpr, target, 0);
+  }else{
+    sqlite3ExprCode(pParse, pExpr, target);
   }
-  return WRC_Continue;
 }
 
 /*
-** Preevaluate constant subexpressions within pExpr and store the
-** results in registers.  Modify pExpr so that the constant subexpresions
-** are TK_REGISTER opcodes that refer to the precomputed values.
+** Generate code that evaluates the given expression and puts the result
+** in register target.
 **
-** This routine is a no-op if the jump to the cookie-check code has
-** already occur.  Since the cookie-check jump is generated prior to
-** any other serious processing, this check ensures that there is no
-** way to accidently bypass the constant initializations.
+** Also make a copy of the expression results into another "cache" register
+** and modify the expression so that the next time it is evaluated,
+** the result is a copy of the cache register.
 **
-** This routine is also a no-op if the SQLITE_FactorOutConst optimization
-** is disabled via the sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS)
-** interface.  This allows test logic to verify that the same answer is
-** obtained for queries regardless of whether or not constants are
-** precomputed into registers or if they are inserted in-line.
+** This routine is used for expressions that are used multiple 
+** times.  They are evaluated once and the results of the expression
+** are reused.
 */
-SQLITE_PRIVATE void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
-  Walker w;
-  if( pParse->cookieGoto ) return;
-  if( (pParse->db->flags & SQLITE_FactorOutConst)!=0 ) return;
-  w.xExprCallback = evalConstExpr;
-  w.xSelectCallback = 0;
-  w.pParse = pParse;
-  sqlite3WalkExpr(&w, pExpr);
-}
+SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
+  Vdbe *v = pParse->pVdbe;
+  int iMem;
 
+  assert( target>0 );
+  assert( pExpr->op!=TK_REGISTER );
+  sqlite3ExprCode(pParse, pExpr, target);
+  iMem = ++pParse->nMem;
+  sqlite3VdbeAddOp2(v, OP_Copy, target, iMem);
+  exprToRegister(pExpr, iMem);
+}
 
 /*
 ** Generate code that pushes the value of every element of the given
 ** expression list into a sequence of registers beginning at target.
 **
 ** Return the number of elements evaluated.
+**
+** The SQLITE_ECEL_DUP flag prevents the arguments from being
+** filled using OP_SCopy.  OP_Copy must be used instead.
+**
+** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
+** factored out into initialization code.
+**
+** The SQLITE_ECEL_REF flag means that expressions in the list with
+** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
+** in registers at srcReg, and so the value can be copied from there.
 */
 SQLITE_PRIVATE int sqlite3ExprCodeExprList(
   Parse *pParse,     /* Parsing context */
   ExprList *pList,   /* The expression list to be coded */
   int target,        /* Where to write results */
-  int doHardCopy     /* Make a hard copy of every element */
+  int srcReg,        /* Source registers if SQLITE_ECEL_REF */
+  u8 flags           /* SQLITE_ECEL_* flags */
 ){
   struct ExprList_item *pItem;
-  int i, n;
+  int i, j, n;
+  u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
+  Vdbe *v = pParse->pVdbe;
   assert( pList!=0 );
   assert( target>0 );
   assert( pParse->pVdbe!=0 );  /* Never gets this far otherwise */
   n = pList->nExpr;
+  if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
   for(pItem=pList->a, i=0; i<n; i++, pItem++){
     Expr *pExpr = pItem->pExpr;
-    int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
-    if( inReg!=target+i ){
-      sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy,
-                        inReg, target+i);
+    if( (flags & SQLITE_ECEL_REF)!=0 && (j = pList->a[i].u.x.iOrderByCol)>0 ){
+      sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
+    }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
+      sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
+    }else{
+      int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
+      if( inReg!=target+i ){
+        VdbeOp *pOp;
+        if( copyOp==OP_Copy
+         && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
+         && pOp->p1+pOp->p3+1==inReg
+         && pOp->p2+pOp->p3+1==target+i
+        ){
+          pOp->p3++;
+        }else{
+          sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);
+        }
+      }
     }
   }
   return n;
@@ -76024,7 +92959,7 @@ SQLITE_PRIVATE int sqlite3ExprCodeExprList(
 **    x>=y AND x<=z
 **
 ** Code it as such, taking care to do the common subexpression
-** elementation of x.
+** elimination of x.
 */
 static void exprCodeBetween(
   Parse *pParse,    /* Parsing and code generating context */
@@ -76050,8 +92985,7 @@ static void exprCodeBetween(
   compRight.op = TK_LE;
   compRight.pLeft = &exprX;
   compRight.pRight = pExpr->x.pList->a[1].pExpr;
-  exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
-  exprX.op = TK_REGISTER;
+  exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, &regFree1));
   if( jumpIfTrue ){
     sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
   }else{
@@ -76092,24 +93026,26 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
   int r1, r2;
 
   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
-  if( NEVER(v==0) )     return;  /* Existance of VDBE checked by caller */
+  if( NEVER(v==0) )     return;  /* Existence of VDBE checked by caller */
   if( NEVER(pExpr==0) ) return;  /* No way this can happen */
   op = pExpr->op;
   switch( op ){
     case TK_AND: {
       int d2 = sqlite3VdbeMakeLabel(v);
       testcase( jumpIfNull==0 );
-      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
+      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
       sqlite3VdbeResolveLabel(v, d2);
-      sqlite3ExprCachePop(pParse, 1);
+      sqlite3ExprCachePop(pParse);
       break;
     }
     case TK_OR: {
       testcase( jumpIfNull==0 );
       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
+      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
+      sqlite3ExprCachePop(pParse);
       break;
     }
     case TK_NOT: {
@@ -76117,54 +93053,46 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
       break;
     }
+    case TK_IS:
+    case TK_ISNOT:
+      testcase( op==TK_IS );
+      testcase( op==TK_ISNOT );
+      op = (op==TK_IS) ? TK_EQ : TK_NE;
+      jumpIfNull = SQLITE_NULLEQ;
+      /* Fall thru */
     case TK_LT:
     case TK_LE:
     case TK_GT:
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
-      assert( TK_LT==OP_Lt );
-      assert( TK_LE==OP_Le );
-      assert( TK_GT==OP_Gt );
-      assert( TK_GE==OP_Ge );
-      assert( TK_EQ==OP_Eq );
-      assert( TK_NE==OP_Ne );
-      testcase( op==TK_LT );
-      testcase( op==TK_LE );
-      testcase( op==TK_GT );
-      testcase( op==TK_GE );
-      testcase( op==TK_EQ );
-      testcase( op==TK_NE );
       testcase( jumpIfNull==0 );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, jumpIfNull);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      break;
-    }
-    case TK_IS:
-    case TK_ISNOT: {
-      testcase( op==TK_IS );
-      testcase( op==TK_ISNOT );
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
-      op = (op==TK_IS) ? TK_EQ : TK_NE;
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, SQLITE_NULLEQ);
+      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
+      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
+      assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
+      assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
+      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
+      assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
     }
     case TK_ISNULL:
     case TK_NOTNULL: {
-      assert( TK_ISNULL==OP_IsNull );
-      assert( TK_NOTNULL==OP_NotNull );
-      testcase( op==TK_ISNULL );
-      testcase( op==TK_NOTNULL );
+      assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );
+      assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       sqlite3VdbeAddOp2(v, op, r1, dest);
+      VdbeCoverageIf(v, op==TK_ISNULL);
+      VdbeCoverageIf(v, op==TK_NOTNULL);
       testcase( regFree1==0 );
       break;
     }
@@ -76178,16 +93106,23 @@ SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int
       int destIfFalse = sqlite3VdbeMakeLabel(v);
       int destIfNull = jumpIfNull ? dest : destIfFalse;
       sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
+      sqlite3VdbeGoto(v, dest);
       sqlite3VdbeResolveLabel(v, destIfFalse);
       break;
     }
 #endif
     default: {
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
-      sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
-      testcase( regFree1==0 );
-      testcase( jumpIfNull==0 );
+      if( exprAlwaysTrue(pExpr) ){
+        sqlite3VdbeGoto(v, dest);
+      }else if( exprAlwaysFalse(pExpr) ){
+        /* No-op */
+      }else{
+        r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
+        sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
+        VdbeCoverage(v);
+        testcase( regFree1==0 );
+        testcase( jumpIfNull==0 );
+      }
       break;
     }
   }
@@ -76212,7 +93147,7 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
   int r1, r2;
 
   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
-  if( NEVER(v==0) ) return; /* Existance of VDBE checked by caller */
+  if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */
   if( pExpr==0 )    return;
 
   /* The value of pExpr->op and op are related as follows:
@@ -76250,17 +93185,19 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
     case TK_AND: {
       testcase( jumpIfNull==0 );
       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
+      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
+      sqlite3ExprCachePop(pParse);
       break;
     }
     case TK_OR: {
       int d2 = sqlite3VdbeMakeLabel(v);
       testcase( jumpIfNull==0 );
-      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
+      sqlite3ExprCachePush(pParse);
       sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
       sqlite3VdbeResolveLabel(v, d2);
-      sqlite3ExprCachePop(pParse, 1);
+      sqlite3ExprCachePop(pParse);
       break;
     }
     case TK_NOT: {
@@ -76268,46 +93205,44 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
       break;
     }
+    case TK_IS:
+    case TK_ISNOT:
+      testcase( pExpr->op==TK_IS );
+      testcase( pExpr->op==TK_ISNOT );
+      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
+      jumpIfNull = SQLITE_NULLEQ;
+      /* Fall thru */
     case TK_LT:
     case TK_LE:
     case TK_GT:
     case TK_GE:
     case TK_NE:
     case TK_EQ: {
-      testcase( op==TK_LT );
-      testcase( op==TK_LE );
-      testcase( op==TK_GT );
-      testcase( op==TK_GE );
-      testcase( op==TK_EQ );
-      testcase( op==TK_NE );
       testcase( jumpIfNull==0 );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, jumpIfNull);
-      testcase( regFree1==0 );
-      testcase( regFree2==0 );
-      break;
-    }
-    case TK_IS:
-    case TK_ISNOT: {
-      testcase( pExpr->op==TK_IS );
-      testcase( pExpr->op==TK_ISNOT );
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
-      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
-      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
-      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, SQLITE_NULLEQ);
+      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
+      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
+      assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
+      assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
+      assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);
+      assert(TK_NE==OP_Ne); testcase(op==OP_Ne);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);
+      VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       break;
     }
     case TK_ISNULL:
     case TK_NOTNULL: {
-      testcase( op==TK_ISNULL );
-      testcase( op==TK_NOTNULL );
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       sqlite3VdbeAddOp2(v, op, r1, dest);
+      testcase( op==TK_ISNULL );   VdbeCoverageIf(v, op==TK_ISNULL);
+      testcase( op==TK_NOTNULL );  VdbeCoverageIf(v, op==TK_NOTNULL);
       testcase( regFree1==0 );
       break;
     }
@@ -76329,10 +93264,17 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
     }
 #endif
     default: {
-      r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
-      sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
-      testcase( regFree1==0 );
-      testcase( jumpIfNull==0 );
+      if( exprAlwaysFalse(pExpr) ){
+        sqlite3VdbeGoto(v, dest);
+      }else if( exprAlwaysTrue(pExpr) ){
+        /* no-op */
+      }else{
+        r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
+        sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
+        VdbeCoverage(v);
+        testcase( regFree1==0 );
+        testcase( jumpIfNull==0 );
+      }
       break;
     }
   }
@@ -76341,11 +93283,32 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
 }
 
 /*
+** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
+** code generation, and that copy is deleted after code generation. This
+** ensures that the original pExpr is unchanged.
+*/
+SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){
+  sqlite3 *db = pParse->db;
+  Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);
+  if( db->mallocFailed==0 ){
+    sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);
+  }
+  sqlite3ExprDelete(db, pCopy);
+}
+
+
+/*
 ** Do a deep comparison of two expression trees.  Return 0 if the two
 ** expressions are completely identical.  Return 1 if they differ only
 ** by a COLLATE operator at the top level.  Return 2 if there are differences
 ** other than the top-level COLLATE operator.
 **
+** If any subelement of pB has Expr.iTable==(-1) then it is allowed
+** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
+**
+** The pA side might be using TK_REGISTER.  If that is the case and pB is
+** not using TK_REGISTER but is otherwise equivalent, then still return 0.
+**
 ** Sometimes this routine will return 2 even if the two expressions
 ** really are equivalent.  If we cannot prove that the expressions are
 ** identical, we return 2 just to be safe.  So if this routine
@@ -76356,33 +93319,46 @@ SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int
 ** just might result in some slightly slower code.  But returning
 ** an incorrect 0 or 1 could lead to a malfunction.
 */
-SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB){
-  if( pA==0||pB==0 ){
+SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
+  u32 combinedFlags;
+  if( pA==0 || pB==0 ){
     return pB==pA ? 0 : 2;
   }
-  assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) );
-  assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) );
-  if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
+  combinedFlags = pA->flags | pB->flags;
+  if( combinedFlags & EP_IntValue ){
+    if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
+      return 0;
+    }
     return 2;
   }
-  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
-  if( pA->op!=pB->op ) return 2;
-  if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
-  if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
-  if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
-  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
-  if( ExprHasProperty(pA, EP_IntValue) ){
-    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
-      return 2;
+  if( pA->op!=pB->op ){
+    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
+      return 1;
     }
-  }else if( pA->op!=TK_COLUMN && pA->u.zToken ){
-    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
-    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
-      return 2;
+    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
+      return 1;
+    }
+    return 2;
+  }
+  if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
+    if( pA->op==TK_FUNCTION ){
+      if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
+    }else if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
+      return pA->op==TK_COLLATE ? 1 : 2;
+    }
+  }
+  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
+  if( ALWAYS((combinedFlags & EP_TokenOnly)==0) ){
+    if( combinedFlags & EP_xIsSelect ) return 2;
+    if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
+    if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
+    if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
+    if( ALWAYS((combinedFlags & EP_Reduced)==0) && pA->op!=TK_STRING ){
+      if( pA->iColumn!=pB->iColumn ) return 2;
+      if( pA->iTable!=pB->iTable 
+       && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
     }
   }
-  if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
-  if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
   return 0;
 }
 
@@ -76390,6 +93366,9 @@ SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB){
 ** Compare two ExprList objects.  Return 0 if they are identical and 
 ** non-zero if they differ in any way.
 **
+** If any subelement of pB has Expr.iTable==(-1) then it is allowed
+** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
+**
 ** This routine might return non-zero for equivalent ExprLists.  The
 ** only consequence will be disabled optimizations.  But this routine
 ** must never return 0 if the two ExprList objects are different, or
@@ -76398,7 +93377,7 @@ SQLITE_PRIVATE int sqlite3ExprCompare(Expr *pA, Expr *pB){
 ** Two NULL pointers are considered to be the same.  But a NULL pointer
 ** always differs from a non-NULL pointer.
 */
-SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
+SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
   int i;
   if( pA==0 && pB==0 ) return 0;
   if( pA==0 || pB==0 ) return 1;
@@ -76407,12 +93386,164 @@ SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
     Expr *pExprA = pA->a[i].pExpr;
     Expr *pExprB = pB->a[i].pExpr;
     if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
-    if( sqlite3ExprCompare(pExprA, pExprB) ) return 1;
+    if( sqlite3ExprCompare(pExprA, pExprB, iTab) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Return true if we can prove the pE2 will always be true if pE1 is
+** true.  Return false if we cannot complete the proof or if pE2 might
+** be false.  Examples:
+**
+**     pE1: x==5       pE2: x==5             Result: true
+**     pE1: x>0        pE2: x==5             Result: false
+**     pE1: x=21       pE2: x=21 OR y=43     Result: true
+**     pE1: x!=123     pE2: x IS NOT NULL    Result: true
+**     pE1: x!=?1      pE2: x IS NOT NULL    Result: true
+**     pE1: x IS NULL  pE2: x IS NOT NULL    Result: false
+**     pE1: x IS ?2    pE2: x IS NOT NULL    Reuslt: false
+**
+** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
+** Expr.iTable<0 then assume a table number given by iTab.
+**
+** When in doubt, return false.  Returning true might give a performance
+** improvement.  Returning false might cause a performance reduction, but
+** it will always give the correct answer and is hence always safe.
+*/
+SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Expr *pE1, Expr *pE2, int iTab){
+  if( sqlite3ExprCompare(pE1, pE2, iTab)==0 ){
+    return 1;
+  }
+  if( pE2->op==TK_OR
+   && (sqlite3ExprImpliesExpr(pE1, pE2->pLeft, iTab)
+             || sqlite3ExprImpliesExpr(pE1, pE2->pRight, iTab) )
+  ){
+    return 1;
+  }
+  if( pE2->op==TK_NOTNULL
+   && sqlite3ExprCompare(pE1->pLeft, pE2->pLeft, iTab)==0
+   && (pE1->op!=TK_ISNULL && pE1->op!=TK_IS)
+  ){
+    return 1;
   }
   return 0;
 }
 
 /*
+** An instance of the following structure is used by the tree walker
+** to determine if an expression can be evaluated by reference to the
+** index only, without having to do a search for the corresponding
+** table entry.  The IdxCover.pIdx field is the index.  IdxCover.iCur
+** is the cursor for the table.
+*/
+struct IdxCover {
+  Index *pIdx;     /* The index to be tested for coverage */
+  int iCur;        /* Cursor number for the table corresponding to the index */
+};
+
+/*
+** Check to see if there are references to columns in table 
+** pWalker->u.pIdxCover->iCur can be satisfied using the index
+** pWalker->u.pIdxCover->pIdx.
+*/
+static int exprIdxCover(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN
+   && pExpr->iTable==pWalker->u.pIdxCover->iCur
+   && sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0
+  ){
+    pWalker->eCode = 1;
+    return WRC_Abort;
+  }
+  return WRC_Continue;
+}
+
+/*
+** Determine if an index pIdx on table with cursor iCur contains will
+** the expression pExpr.  Return true if the index does cover the
+** expression and false if the pExpr expression references table columns
+** that are not found in the index pIdx.
+**
+** An index covering an expression means that the expression can be
+** evaluated using only the index and without having to lookup the
+** corresponding table entry.
+*/
+SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(
+  Expr *pExpr,        /* The index to be tested */
+  int iCur,           /* The cursor number for the corresponding table */
+  Index *pIdx         /* The index that might be used for coverage */
+){
+  Walker w;
+  struct IdxCover xcov;
+  memset(&w, 0, sizeof(w));
+  xcov.iCur = iCur;
+  xcov.pIdx = pIdx;
+  w.xExprCallback = exprIdxCover;
+  w.u.pIdxCover = &xcov;
+  sqlite3WalkExpr(&w, pExpr);
+  return !w.eCode;
+}
+
+
+/*
+** An instance of the following structure is used by the tree walker
+** to count references to table columns in the arguments of an 
+** aggregate function, in order to implement the
+** sqlite3FunctionThisSrc() routine.
+*/
+struct SrcCount {
+  SrcList *pSrc;   /* One particular FROM clause in a nested query */
+  int nThis;       /* Number of references to columns in pSrcList */
+  int nOther;      /* Number of references to columns in other FROM clauses */
+};
+
+/*
+** Count the number of references to columns.
+*/
+static int exprSrcCount(Walker *pWalker, Expr *pExpr){
+  /* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc()
+  ** is always called before sqlite3ExprAnalyzeAggregates() and so the
+  ** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN.  If
+  ** sqlite3FunctionUsesThisSrc() is used differently in the future, the
+  ** NEVER() will need to be removed. */
+  if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){
+    int i;
+    struct SrcCount *p = pWalker->u.pSrcCount;
+    SrcList *pSrc = p->pSrc;
+    int nSrc = pSrc ? pSrc->nSrc : 0;
+    for(i=0; i<nSrc; i++){
+      if( pExpr->iTable==pSrc->a[i].iCursor ) break;
+    }
+    if( i<nSrc ){
+      p->nThis++;
+    }else{
+      p->nOther++;
+    }
+  }
+  return WRC_Continue;
+}
+
+/*
+** Determine if any of the arguments to the pExpr Function reference
+** pSrcList.  Return true if they do.  Also return true if the function
+** has no arguments or has only constant arguments.  Return false if pExpr
+** references columns but not columns of tables found in pSrcList.
+*/
+SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
+  Walker w;
+  struct SrcCount cnt;
+  assert( pExpr->op==TK_AGG_FUNCTION );
+  memset(&w, 0, sizeof(w));
+  w.xExprCallback = exprSrcCount;
+  w.u.pSrcCount = &cnt;
+  cnt.pSrc = pSrcList;
+  cnt.nThis = 0;
+  cnt.nOther = 0;
+  sqlite3WalkExprList(&w, pExpr->x.pList);
+  return cnt.nThis>0 || cnt.nOther==0;
+}
+
+/*
 ** Add a new element to the pAggInfo->aCol[] array.  Return the index of
 ** the new element.  Return a negative number if malloc fails.
 */
@@ -76422,9 +93553,7 @@ static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
        db,
        pInfo->aCol,
        sizeof(pInfo->aCol[0]),
-       3,
        &pInfo->nColumn,
-       &pInfo->nColumnAlloc,
        &i
   );
   return i;
@@ -76440,9 +93569,7 @@ static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
        db, 
        pInfo->aFunc,
        sizeof(pInfo->aFunc[0]),
-       3,
        &pInfo->nFunc,
-       &pInfo->nFuncAlloc,
        &i
   );
   return i;
@@ -76471,7 +93598,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
         struct SrcList_item *pItem = pSrcList->a;
         for(i=0; i<pSrcList->nSrc; i++, pItem++){
           struct AggInfo_col *pCol;
-          assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
+          assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
           if( pExpr->iTable==pItem->iCursor ){
             /* If we reach this point, it means that pExpr refers to a table
             ** that is in the FROM clause of the aggregate query.  
@@ -76520,7 +93647,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
             ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
             ** pAggInfo->aCol[] entry.
             */
-            ExprSetIrreducible(pExpr);
+            ExprSetVVAProperty(pExpr, EP_NoReduce);
             pExpr->pAggInfo = pAggInfo;
             pExpr->op = TK_AGG_COLUMN;
             pExpr->iAgg = (i16)k;
@@ -76531,15 +93658,15 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
       return WRC_Prune;
     }
     case TK_AGG_FUNCTION: {
-      /* The pNC->nDepth==0 test causes aggregate functions in subqueries
-      ** to be ignored */
-      if( pNC->nDepth==0 ){
+      if( (pNC->ncFlags & NC_InAggFunc)==0
+       && pWalker->walkerDepth==pExpr->op2
+      ){
         /* Check to see if pExpr is a duplicate of another aggregate 
         ** function that is already in the pAggInfo structure
         */
         struct AggInfo_func *pItem = pAggInfo->aFunc;
         for(i=0; i<pAggInfo->nFunc; i++, pItem++){
-          if( sqlite3ExprCompare(pItem->pExpr, pExpr)==0 ){
+          if( sqlite3ExprCompare(pItem->pExpr, pExpr, -1)==0 ){
             break;
           }
         }
@@ -76555,7 +93682,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
             pItem->iMem = ++pParse->nMem;
             assert( !ExprHasProperty(pExpr, EP_IntValue) );
             pItem->pFunc = sqlite3FindFunction(pParse->db,
-                   pExpr->u.zToken, sqlite3Strlen30(pExpr->u.zToken),
+                   pExpr->u.zToken, 
                    pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
             if( pExpr->flags & EP_Distinct ){
               pItem->iDistinct = pParse->nTab++;
@@ -76566,38 +93693,36 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
         }
         /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
         */
-        assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
-        ExprSetIrreducible(pExpr);
+        assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
+        ExprSetVVAProperty(pExpr, EP_NoReduce);
         pExpr->iAgg = (i16)i;
         pExpr->pAggInfo = pAggInfo;
         return WRC_Prune;
+      }else{
+        return WRC_Continue;
       }
     }
   }
   return WRC_Continue;
 }
 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
-  NameContext *pNC = pWalker->u.pNC;
-  if( pNC->nDepth==0 ){
-    pNC->nDepth++;
-    sqlite3WalkSelect(pWalker, pSelect);
-    pNC->nDepth--;
-    return WRC_Prune;
-  }else{
-    return WRC_Continue;
-  }
+  UNUSED_PARAMETER(pWalker);
+  UNUSED_PARAMETER(pSelect);
+  return WRC_Continue;
 }
 
 /*
-** Analyze the given expression looking for aggregate functions and
-** for variables that need to be added to the pParse->aAgg[] array.
-** Make additional entries to the pParse->aAgg[] array as necessary.
+** Analyze the pExpr expression looking for aggregate functions and
+** for variables that need to be added to AggInfo object that pNC->pAggInfo
+** points to.  Additional entries are made on the AggInfo object as
+** necessary.
 **
 ** This routine should only be called after the expression has been
 ** analyzed by sqlite3ResolveExprNames().
 */
 SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
   Walker w;
+  memset(&w, 0, sizeof(w));
   w.xExprCallback = analyzeAggregate;
   w.xSelectCallback = analyzeAggregatesInSelect;
   w.u.pNC = pNC;
@@ -76636,7 +93761,7 @@ SQLITE_PRIVATE int sqlite3GetTempReg(Parse *pParse){
 ** purpose.
 **
 ** If a register is currently being used by the column cache, then
-** the dallocation is deferred until the column cache line that uses
+** the deallocation is deferred until the column cache line that uses
 ** the register becomes stale.
 */
 SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
@@ -76678,6 +93803,37 @@ SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
   }
 }
 
+/*
+** Mark all temporary registers as being unavailable for reuse.
+*/
+SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse *pParse){
+  pParse->nTempReg = 0;
+  pParse->nRangeReg = 0;
+}
+
+/*
+** Validate that no temporary register falls within the range of
+** iFirst..iLast, inclusive.  This routine is only call from within assert()
+** statements.
+*/
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
+  int i;
+  if( pParse->nRangeReg>0
+   && pParse->iRangeReg+pParse->nRangeReg<iLast
+   && pParse->iRangeReg>=iFirst
+  ){
+     return 0;
+  }
+  for(i=0; i<pParse->nTempReg; i++){
+    if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
+      return 0;
+    }
+  }
+  return 1;
+}
+#endif /* SQLITE_DEBUG */
+
 /************** End of expr.c ************************************************/
 /************** Begin file alter.c *******************************************/
 /*
@@ -76694,6 +93850,7 @@ SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
 ** This file contains C code routines that used to generate VDBE code
 ** that implements the ALTER TABLE command.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** The code in this file only exists if we are not omitting the
@@ -76758,8 +93915,8 @@ static void renameTableFunc(
       assert( len>0 );
     } while( token!=TK_LP && token!=TK_USING );
 
-    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", ((u8*)tname.z) - zSql, zSql, 
-       zTableName, tname.z+tname.n);
+    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", (int)(((u8*)tname.z) - zSql),
+       zSql, zTableName, tname.z+tname.n);
     sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
   }
 }
@@ -76797,6 +93954,7 @@ static void renameParentFunc(
   int token;                      /* Type of token */
 
   UNUSED_PARAMETER(NotUsed);
+  if( zInput==0 || zOld==0 ) return;
   for(z=zInput; *z; z=z+n){
     n = sqlite3GetToken(z, &token);
     if( token==TK_REFERENCES ){
@@ -76806,12 +93964,13 @@ static void renameParentFunc(
         n = sqlite3GetToken(z, &token);
       }while( token==TK_SPACE );
 
+      if( token==TK_ILLEGAL ) break;
       zParent = sqlite3DbStrNDup(db, (const char *)z, n);
       if( zParent==0 ) break;
       sqlite3Dequote(zParent);
       if( 0==sqlite3StrICmp((const char *)zOld, zParent) ){
         char *zOut = sqlite3MPrintf(db, "%s%.*s\"%w\"", 
-            (zOutput?zOutput:""), z-zInput, zInput, (const char *)zNew
+            (zOutput?zOutput:""), (int)(z-zInput), zInput, (const char *)zNew
         );
         sqlite3DbFree(db, zOutput);
         zOutput = zOut;
@@ -76854,8 +94013,8 @@ static void renameTriggerFunc(
   UNUSED_PARAMETER(NotUsed);
 
   /* The principle used to locate the table name in the CREATE TRIGGER 
-  ** statement is that the table name is the first token that is immediatedly
-  ** preceded by either TK_ON or TK_DOT and immediatedly followed by one
+  ** statement is that the table name is the first token that is immediately
+  ** preceded by either TK_ON or TK_DOT and immediately followed by one
   ** of TK_WHEN, TK_BEGIN or TK_FOR.
   */
   if( zSql ){
@@ -76897,8 +94056,8 @@ static void renameTriggerFunc(
     /* Variable tname now contains the token that is the old table-name
     ** in the CREATE TRIGGER statement.
     */
-    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", ((u8*)tname.z) - zSql, zSql, 
-       zTableName, tname.z+tname.n);
+    zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", (int)(((u8*)tname.z) - zSql),
+       zSql, zTableName, tname.z+tname.n);
     sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC);
   }
 }
@@ -76908,7 +94067,7 @@ static void renameTriggerFunc(
 ** Register built-in functions used to help implement ALTER TABLE
 */
 SQLITE_PRIVATE void sqlite3AlterFunctions(void){
-  static SQLITE_WSD FuncDef aAlterTableFuncs[] = {
+  static FuncDef aAlterTableFuncs[] = {
     FUNCTION(sqlite_rename_table,   2, 0, 0, renameTableFunc),
 #ifndef SQLITE_OMIT_TRIGGER
     FUNCTION(sqlite_rename_trigger, 2, 0, 0, renameTriggerFunc),
@@ -76917,13 +94076,7 @@ SQLITE_PRIVATE void sqlite3AlterFunctions(void){
     FUNCTION(sqlite_rename_parent,  3, 0, 0, renameParentFunc),
 #endif
   };
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAlterTableFuncs);
-
-  for(i=0; i<ArraySize(aAlterTableFuncs); i++){
-    sqlite3FuncDefInsert(pHash, &aFunc[i]);
-  }
+  sqlite3InsertBuiltinFuncs(aAlterTableFuncs, ArraySize(aAlterTableFuncs));
 }
 
 /*
@@ -77095,7 +94248,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
   assert( pSrc->nSrc==1 );
   assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
 
-  pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+  pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
   if( !pTab ) goto exit_rename_table;
   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
   zDb = db->aDb[iDb].zName;
@@ -77150,7 +94303,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
   }
 #endif
 
-  /* Begin a transaction and code the VerifyCookie for database iDb. 
+  /* Begin a transaction for database iDb. 
   ** Then modify the schema cookie (since the ALTER TABLE modifies the
   ** schema). Open a statement transaction if the table is a virtual
   ** table.
@@ -77170,7 +94323,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   if( pVTab ){
     int i = ++pParse->nMem;
-    sqlite3VdbeAddOp4(v, OP_String8, 0, i, 0, zName, 0);
+    sqlite3VdbeLoadString(v, i, zName);
     sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);
     sqlite3MayAbort(pParse);
   }
@@ -77211,7 +94364,7 @@ SQLITE_PRIVATE void sqlite3AlterRenameTable(
             "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
              "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
             "ELSE name END "
-      "WHERE tbl_name=%Q AND "
+      "WHERE tbl_name=%Q COLLATE nocase AND "
           "(type='table' OR type='index' OR type='trigger');", 
       zDb, SCHEMA_TABLE(iDb), zName, zName, zName, 
 #ifndef SQLITE_OMIT_TRIGGER
@@ -77267,32 +94420,6 @@ exit_rename_table:
   db->flags = savedDbFlags;
 }
 
-
-/*
-** Generate code to make sure the file format number is at least minFormat.
-** The generated code will increase the file format number if necessary.
-*/
-SQLITE_PRIVATE void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
-  Vdbe *v;
-  v = sqlite3GetVdbe(pParse);
-  /* The VDBE should have been allocated before this routine is called.
-  ** If that allocation failed, we would have quit before reaching this
-  ** point */
-  if( ALWAYS(v) ){
-    int r1 = sqlite3GetTempReg(pParse);
-    int r2 = sqlite3GetTempReg(pParse);
-    int j1;
-    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
-    sqlite3VdbeUsesBtree(v, iDb);
-    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
-    j1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2);
-    sqlite3VdbeJumpHere(v, j1);
-    sqlite3ReleaseTempReg(pParse, r1);
-    sqlite3ReleaseTempReg(pParse, r2);
-  }
-}
-
 /*
 ** This function is called after an "ALTER TABLE ... ADD" statement
 ** has been parsed. Argument pColDef contains the text of the new
@@ -77311,9 +94438,12 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   Column *pCol;             /* The new column */
   Expr *pDflt;              /* Default value for the new column */
   sqlite3 *db;              /* The database connection; */
+  Vdbe *v = pParse->pVdbe;  /* The prepared statement under construction */
+  int r1;                   /* Temporary registers */
 
   db = pParse->db;
   if( pParse->nErr || db->mallocFailed ) return;
+  assert( v!=0 );
   pNew = pParse->pNewTable;
   assert( pNew );
 
@@ -77337,7 +94467,8 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   ** literal NULL, then set pDflt to 0. This simplifies checking
   ** for an SQL NULL default below.
   */
-  if( pDflt && pDflt->op==TK_NULL ){
+  assert( pDflt==0 || pDflt->op==TK_SPAN );
+  if( pDflt && pDflt->pLeft->op==TK_NULL ){
     pDflt = 0;
   }
 
@@ -77345,7 +94476,7 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   ** If there is a NOT NULL constraint, then the default value for the
   ** column must not be NULL.
   */
-  if( pCol->isPrimKey ){
+  if( pCol->colFlags & COLFLAG_PRIMKEY ){
     sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
     return;
   }
@@ -77368,9 +94499,12 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   ** can handle (i.e. not CURRENT_TIME etc.)
   */
   if( pDflt ){
-    sqlite3_value *pVal;
-    if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
-      db->mallocFailed = 1;
+    sqlite3_value *pVal = 0;
+    int rc;
+    rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);
+    assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );
+    if( rc!=SQLITE_OK ){
+      assert( db->mallocFailed == 1 );
       return;
     }
     if( !pVal ){
@@ -77400,11 +94534,18 @@ SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
     db->flags = savedDbFlags;
   }
 
-  /* If the default value of the new column is NULL, then set the file
-  ** format to 2. If the default value of the new column is not NULL,
-  ** the file format becomes 3.
+  /* Make sure the schema version is at least 3.  But do not upgrade
+  ** from less than 3 to 4, as that will corrupt any preexisting DESC
+  ** index.
   */
-  sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
+  r1 = sqlite3GetTempReg(pParse);
+  sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
+  sqlite3VdbeUsesBtree(v, iDb);
+  sqlite3VdbeAddOp2(v, OP_AddImm, r1, -2);
+  sqlite3VdbeAddOp2(v, OP_IfPos, r1, sqlite3VdbeCurrentAddr(v)+2);
+  VdbeCoverage(v);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, 3);
+  sqlite3ReleaseTempReg(pParse, r1);
 
   /* Reload the schema of the modified table. */
   reloadTableSchema(pParse, pTab, pTab->zName);
@@ -77438,7 +94579,7 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   assert( pParse->pNewTable==0 );
   assert( sqlite3BtreeHoldsAllMutexes(db) );
   if( db->mallocFailed ) goto exit_begin_add_column;
-  pTab = sqlite3LocateTable(pParse, 0, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+  pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
   if( !pTab ) goto exit_begin_add_column;
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
@@ -77478,7 +94619,7 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
   pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
   pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);
   if( !pNew->aCol || !pNew->zName ){
-    db->mallocFailed = 1;
+    assert( db->mallocFailed );
     goto exit_begin_add_column;
   }
   memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
@@ -77486,9 +94627,7 @@ SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
     Column *pCol = &pNew->aCol[i];
     pCol->zName = sqlite3DbStrDup(db, pCol->zName);
     pCol->zColl = 0;
-    pCol->zType = 0;
     pCol->pDflt = 0;
-    pCol->zDflt = 0;
   }
   pNew->pSchema = db->aDb[iDb].pSchema;
   pNew->addColOffset = pTab->addColOffset;
@@ -77509,7 +94648,7 @@ exit_begin_add_column:
 /************** End of alter.c ***********************************************/
 /************** Begin file analyze.c *****************************************/
 /*
-** 2005 July 8
+** 2005-07-08
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -77530,15 +94669,23 @@ exit_begin_add_column:
 **    CREATE TABLE sqlite_stat1(tbl, idx, stat);
 **    CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample);
 **    CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample);
+**    CREATE TABLE sqlite_stat4(tbl, idx, nEq, nLt, nDLt, sample);
 **
 ** Additional tables might be added in future releases of SQLite.
 ** The sqlite_stat2 table is not created or used unless the SQLite version
 ** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled
 ** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.
-** The sqlite_stat2 table is superceded by sqlite_stat3, which is only
+** The sqlite_stat2 table is superseded by sqlite_stat3, which is only
 ** created and used by SQLite versions 3.7.9 and later and with
-** SQLITE_ENABLE_STAT3 defined.  The fucntionality of sqlite_stat3
-** is a superset of sqlite_stat2.  
+** SQLITE_ENABLE_STAT3 defined.  The functionality of sqlite_stat3
+** is a superset of sqlite_stat2.  The sqlite_stat4 is an enhanced
+** version of sqlite_stat3 and is only available when compiled with
+** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.1 and later.  It is
+** not possible to enable both STAT3 and STAT4 at the same time.  If they
+** are both enabled, then STAT4 takes precedence.
+**
+** For most applications, sqlite_stat1 provides all the statistics required
+** for the query planner to make good choices.
 **
 ** Format of sqlite_stat1:
 **
@@ -77546,7 +94693,8 @@ exit_begin_add_column:
 ** name in the idx column.  The tbl column is the name of the table to
 ** which the index belongs.  In each such row, the stat column will be
 ** a string consisting of a list of integers.  The first integer in this
-** list is the number of rows in the index and in the table.  The second
+** list is the number of rows in the index.  (This is the same as the
+** number of rows in the table, except for partial indices.)  The second
 ** integer is the average number of rows in the index that have the same
 ** value in the first column of the index.  The third integer is the average
 ** number of rows in the index that have the same value for the first two
@@ -77593,53 +94741,82 @@ exit_begin_add_column:
 **
 ** Format for sqlite_stat3:
 **
-** The sqlite_stat3 is an enhancement to sqlite_stat2.  A new name is
-** used to avoid compatibility problems.  
+** The sqlite_stat3 format is a subset of sqlite_stat4.  Hence, the
+** sqlite_stat4 format will be described first.  Further information
+** about sqlite_stat3 follows the sqlite_stat4 description.
 **
-** The format of the sqlite_stat3 table is similar to the format of
-** the sqlite_stat2 table.  There are multiple entries for each index.
+** Format for sqlite_stat4:
+**
+** As with sqlite_stat2, the sqlite_stat4 table contains histogram data
+** to aid the query planner in choosing good indices based on the values
+** that indexed columns are compared against in the WHERE clauses of
+** queries.
+**
+** The sqlite_stat4 table contains multiple entries for each index.
 ** The idx column names the index and the tbl column is the table of the
 ** index.  If the idx and tbl columns are the same, then the sample is
-** of the INTEGER PRIMARY KEY.  The sample column is a value taken from
-** the left-most column of the index.  The nEq column is the approximate
-** number of entires in the index whose left-most column exactly matches
-** the sample.  nLt is the approximate number of entires whose left-most
-** column is less than the sample.  The nDLt column is the approximate
-** number of distinct left-most entries in the index that are less than
-** the sample.
-**
-** Future versions of SQLite might change to store a string containing
-** multiple integers values in the nDLt column of sqlite_stat3.  The first
-** integer will be the number of prior index entires that are distinct in
-** the left-most column.  The second integer will be the number of prior index
-** entries that are distinct in the first two columns.  The third integer
-** will be the number of prior index entries that are distinct in the first
-** three columns.  And so forth.  With that extension, the nDLt field is
-** similar in function to the sqlite_stat1.stat field.
-**
-** There can be an arbitrary number of sqlite_stat3 entries per index.
-** The ANALYZE command will typically generate sqlite_stat3 tables
+** of the INTEGER PRIMARY KEY.  The sample column is a blob which is the
+** binary encoding of a key from the index.  The nEq column is a
+** list of integers.  The first integer is the approximate number
+** of entries in the index whose left-most column exactly matches
+** the left-most column of the sample.  The second integer in nEq
+** is the approximate number of entries in the index where the
+** first two columns match the first two columns of the sample.
+** And so forth.  nLt is another list of integers that show the approximate
+** number of entries that are strictly less than the sample.  The first
+** integer in nLt contains the number of entries in the index where the
+** left-most column is less than the left-most column of the sample.
+** The K-th integer in the nLt entry is the number of index entries 
+** where the first K columns are less than the first K columns of the
+** sample.  The nDLt column is like nLt except that it contains the 
+** number of distinct entries in the index that are less than the
+** sample.
+**
+** There can be an arbitrary number of sqlite_stat4 entries per index.
+** The ANALYZE command will typically generate sqlite_stat4 tables
 ** that contain between 10 and 40 samples which are distributed across
 ** the key space, though not uniformly, and which include samples with
-** largest possible nEq values.
+** large nEq values.
+**
+** Format for sqlite_stat3 redux:
+**
+** The sqlite_stat3 table is like sqlite_stat4 except that it only
+** looks at the left-most column of the index.  The sqlite_stat3.sample
+** column contains the actual value of the left-most column instead
+** of a blob encoding of the complete index key as is found in
+** sqlite_stat4.sample.  The nEq, nLt, and nDLt entries of sqlite_stat3
+** all contain just a single integer which is the same as the first
+** integer in the equivalent columns in sqlite_stat4.
 */
 #ifndef SQLITE_OMIT_ANALYZE
+/* #include "sqliteInt.h" */
+
+#if defined(SQLITE_ENABLE_STAT4)
+# define IsStat4     1
+# define IsStat3     0
+#elif defined(SQLITE_ENABLE_STAT3)
+# define IsStat4     0
+# define IsStat3     1
+#else
+# define IsStat4     0
+# define IsStat3     0
+# undef SQLITE_STAT4_SAMPLES
+# define SQLITE_STAT4_SAMPLES 1
+#endif
+#define IsStat34    (IsStat3+IsStat4)  /* 1 for STAT3 or STAT4. 0 otherwise */
 
 /*
-** This routine generates code that opens the sqlite_stat1 table for
-** writing with cursor iStatCur. If the library was built with the
-** SQLITE_ENABLE_STAT3 macro defined, then the sqlite_stat3 table is
-** opened for writing using cursor (iStatCur+1)
+** This routine generates code that opens the sqlite_statN tables.
+** The sqlite_stat1 table is always relevant.  sqlite_stat2 is now
+** obsolete.  sqlite_stat3 and sqlite_stat4 are only opened when
+** appropriate compile-time options are provided.
 **
-** If the sqlite_stat1 tables does not previously exist, it is created.
-** Similarly, if the sqlite_stat3 table does not exist and the library
-** is compiled with SQLITE_ENABLE_STAT3 defined, it is created. 
+** If the sqlite_statN tables do not previously exist, it is created.
 **
 ** Argument zWhere may be a pointer to a buffer containing a table name,
 ** or it may be a NULL pointer. If it is not NULL, then all entries in
-** the sqlite_stat1 and (if applicable) sqlite_stat3 tables associated
-** with the named table are deleted. If zWhere==0, then code is generated
-** to delete all stat table entries.
+** the sqlite_statN tables associated with the named table are deleted.
+** If zWhere==0, then code is generated to delete all stat table entries.
 */
 static void openStatTable(
   Parse *pParse,          /* Parsing context */
@@ -77653,18 +94830,24 @@ static void openStatTable(
     const char *zCols;
   } aTable[] = {
     { "sqlite_stat1", "tbl,idx,stat" },
-#ifdef SQLITE_ENABLE_STAT3
+#if defined(SQLITE_ENABLE_STAT4)
+    { "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" },
+    { "sqlite_stat3", 0 },
+#elif defined(SQLITE_ENABLE_STAT3)
     { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" },
+    { "sqlite_stat4", 0 },
+#else
+    { "sqlite_stat3", 0 },
+    { "sqlite_stat4", 0 },
 #endif
   };
-
-  int aRoot[] = {0, 0};
-  u8 aCreateTbl[] = {0, 0};
-
   int i;
   sqlite3 *db = pParse->db;
   Db *pDb;
   Vdbe *v = sqlite3GetVdbe(pParse);
+  int aRoot[ArraySize(aTable)];
+  u8 aCreateTbl[ArraySize(aTable)];
+
   if( v==0 ) return;
   assert( sqlite3BtreeHoldsAllMutexes(db) );
   assert( sqlite3VdbeDb(v)==db );
@@ -77677,259 +94860,736 @@ static void openStatTable(
     const char *zTab = aTable[i].zName;
     Table *pStat;
     if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){
-      /* The sqlite_stat[12] table does not exist. Create it. Note that a 
-      ** side-effect of the CREATE TABLE statement is to leave the rootpage 
-      ** of the new table in register pParse->regRoot. This is important 
-      ** because the OpenWrite opcode below will be needing it. */
-      sqlite3NestedParse(pParse,
-          "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols
-      );
-      aRoot[i] = pParse->regRoot;
-      aCreateTbl[i] = 1;
+      if( aTable[i].zCols ){
+        /* The sqlite_statN table does not exist. Create it. Note that a 
+        ** side-effect of the CREATE TABLE statement is to leave the rootpage 
+        ** of the new table in register pParse->regRoot. This is important 
+        ** because the OpenWrite opcode below will be needing it. */
+        sqlite3NestedParse(pParse,
+            "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols
+        );
+        aRoot[i] = pParse->regRoot;
+        aCreateTbl[i] = OPFLAG_P2ISREG;
+      }
     }else{
       /* The table already exists. If zWhere is not NULL, delete all entries 
       ** associated with the table zWhere. If zWhere is NULL, delete the
       ** entire contents of the table. */
       aRoot[i] = pStat->tnum;
+      aCreateTbl[i] = 0;
       sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);
       if( zWhere ){
         sqlite3NestedParse(pParse,
-           "DELETE FROM %Q.%s WHERE %s=%Q", pDb->zName, zTab, zWhereType, zWhere
+           "DELETE FROM %Q.%s WHERE %s=%Q",
+           pDb->zName, zTab, zWhereType, zWhere
         );
       }else{
-        /* The sqlite_stat[12] table already exists.  Delete all rows. */
+        /* The sqlite_stat[134] table already exists.  Delete all rows. */
         sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
       }
     }
   }
 
-  /* Open the sqlite_stat[13] tables for writing. */
-  for(i=0; i<ArraySize(aTable); i++){
-    sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb);
-    sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32);
+  /* Open the sqlite_stat[134] tables for writing. */
+  for(i=0; aTable[i].zCols; i++){
+    assert( i<ArraySize(aTable) );
+    sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3);
     sqlite3VdbeChangeP5(v, aCreateTbl[i]);
+    VdbeComment((v, aTable[i].zName));
   }
 }
 
 /*
-** Recommended number of samples for sqlite_stat3
+** Recommended number of samples for sqlite_stat4
 */
-#ifndef SQLITE_STAT3_SAMPLES
-# define SQLITE_STAT3_SAMPLES 24
+#ifndef SQLITE_STAT4_SAMPLES
+# define SQLITE_STAT4_SAMPLES 24
 #endif
 
 /*
-** Three SQL functions - stat3_init(), stat3_push(), and stat3_pop() -
+** Three SQL functions - stat_init(), stat_push(), and stat_get() -
 ** share an instance of the following structure to hold their state
 ** information.
 */
-typedef struct Stat3Accum Stat3Accum;
-struct Stat3Accum {
+typedef struct Stat4Accum Stat4Accum;
+typedef struct Stat4Sample Stat4Sample;
+struct Stat4Sample {
+  tRowcnt *anEq;                  /* sqlite_stat4.nEq */
+  tRowcnt *anDLt;                 /* sqlite_stat4.nDLt */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  tRowcnt *anLt;                  /* sqlite_stat4.nLt */
+  union {
+    i64 iRowid;                     /* Rowid in main table of the key */
+    u8 *aRowid;                     /* Key for WITHOUT ROWID tables */
+  } u;
+  u32 nRowid;                     /* Sizeof aRowid[] */
+  u8 isPSample;                   /* True if a periodic sample */
+  int iCol;                       /* If !isPSample, the reason for inclusion */
+  u32 iHash;                      /* Tiebreaker hash */
+#endif
+};                                                    
+struct Stat4Accum {
   tRowcnt nRow;             /* Number of rows in the entire table */
   tRowcnt nPSample;         /* How often to do a periodic sample */
-  int iMin;                 /* Index of entry with minimum nEq and hash */
+  int nCol;                 /* Number of columns in index + pk/rowid */
+  int nKeyCol;              /* Number of index columns w/o the pk/rowid */
   int mxSample;             /* Maximum number of samples to accumulate */
-  int nSample;              /* Current number of samples */
+  Stat4Sample current;      /* Current row as a Stat4Sample */
   u32 iPrn;                 /* Pseudo-random number used for sampling */
-  struct Stat3Sample {
-    i64 iRowid;                /* Rowid in main table of the key */
-    tRowcnt nEq;               /* sqlite_stat3.nEq */
-    tRowcnt nLt;               /* sqlite_stat3.nLt */
-    tRowcnt nDLt;              /* sqlite_stat3.nDLt */
-    u8 isPSample;              /* True if a periodic sample */
-    u32 iHash;                 /* Tiebreaker hash */
-  } *a;                     /* An array of samples */
+  Stat4Sample *aBest;       /* Array of nCol best samples */
+  int iMin;                 /* Index in a[] of entry with minimum score */
+  int nSample;              /* Current number of samples */
+  int iGet;                 /* Index of current sample accessed by stat_get() */
+  Stat4Sample *a;           /* Array of mxSample Stat4Sample objects */
+  sqlite3 *db;              /* Database connection, for malloc() */
 };
 
-#ifdef SQLITE_ENABLE_STAT3
+/* Reclaim memory used by a Stat4Sample
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static void sampleClear(sqlite3 *db, Stat4Sample *p){
+  assert( db!=0 );
+  if( p->nRowid ){
+    sqlite3DbFree(db, p->u.aRowid);
+    p->nRowid = 0;
+  }
+}
+#endif
+
+/* Initialize the BLOB value of a ROWID
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){
+  assert( db!=0 );
+  if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
+  p->u.aRowid = sqlite3DbMallocRawNN(db, n);
+  if( p->u.aRowid ){
+    p->nRowid = n;
+    memcpy(p->u.aRowid, pData, n);
+  }else{
+    p->nRowid = 0;
+  }
+}
+#endif
+
+/* Initialize the INTEGER value of a ROWID.
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static void sampleSetRowidInt64(sqlite3 *db, Stat4Sample *p, i64 iRowid){
+  assert( db!=0 );
+  if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);
+  p->nRowid = 0;
+  p->u.iRowid = iRowid;
+}
+#endif
+
+
+/*
+** Copy the contents of object (*pFrom) into (*pTo).
+*/
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+static void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){
+  pTo->isPSample = pFrom->isPSample;
+  pTo->iCol = pFrom->iCol;
+  pTo->iHash = pFrom->iHash;
+  memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol);
+  memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol);
+  memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol);
+  if( pFrom->nRowid ){
+    sampleSetRowid(p->db, pTo, pFrom->nRowid, pFrom->u.aRowid);
+  }else{
+    sampleSetRowidInt64(p->db, pTo, pFrom->u.iRowid);
+  }
+}
+#endif
+
+/*
+** Reclaim all memory of a Stat4Accum structure.
+*/
+static void stat4Destructor(void *pOld){
+  Stat4Accum *p = (Stat4Accum*)pOld;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  int i;
+  for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i);
+  for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i);
+  sampleClear(p->db, &p->current);
+#endif
+  sqlite3DbFree(p->db, p);
+}
+
 /*
-** Implementation of the stat3_init(C,S) SQL function.  The two parameters
-** are the number of rows in the table or index (C) and the number of samples
-** to accumulate (S).
+** Implementation of the stat_init(N,K,C) SQL function. The three parameters
+** are:
+**     N:    The number of columns in the index including the rowid/pk (note 1)
+**     K:    The number of columns in the index excluding the rowid/pk.
+**     C:    The number of rows in the index (note 2)
+**
+** Note 1:  In the special case of the covering index that implements a
+** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the
+** total number of columns in the table.
 **
-** This routine allocates the Stat3Accum object.
+** Note 2:  C is only used for STAT3 and STAT4.
 **
-** The return value is the Stat3Accum object (P).
+** For indexes on ordinary rowid tables, N==K+1.  But for indexes on
+** WITHOUT ROWID tables, N=K+P where P is the number of columns in the
+** PRIMARY KEY of the table.  The covering index that implements the
+** original WITHOUT ROWID table as N==K as a special case.
+**
+** This routine allocates the Stat4Accum object in heap memory. The return 
+** value is a pointer to the Stat4Accum object.  The datatype of the
+** return value is BLOB, but it is really just a pointer to the Stat4Accum
+** object.
 */
-static void stat3Init(
+static void statInit(
   sqlite3_context *context,
   int argc,
   sqlite3_value **argv
 ){
-  Stat3Accum *p;
-  tRowcnt nRow;
-  int mxSample;
-  int n;
+  Stat4Accum *p;
+  int nCol;                       /* Number of columns in index being sampled */
+  int nKeyCol;                    /* Number of key columns */
+  int nColUp;                     /* nCol rounded up for alignment */
+  int n;                          /* Bytes of space to allocate */
+  sqlite3 *db;                    /* Database connection */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  int mxSample = SQLITE_STAT4_SAMPLES;
+#endif
 
+  /* Decode the three function arguments */
   UNUSED_PARAMETER(argc);
-  nRow = (tRowcnt)sqlite3_value_int64(argv[0]);
-  mxSample = sqlite3_value_int(argv[1]);
-  n = sizeof(*p) + sizeof(p->a[0])*mxSample;
-  p = sqlite3_malloc( n );
+  nCol = sqlite3_value_int(argv[0]);
+  assert( nCol>0 );
+  nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol;
+  nKeyCol = sqlite3_value_int(argv[1]);
+  assert( nKeyCol<=nCol );
+  assert( nKeyCol>0 );
+
+  /* Allocate the space required for the Stat4Accum object */
+  n = sizeof(*p) 
+    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anEq */
+    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anDLt */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anLt */
+    + sizeof(Stat4Sample)*(nCol+mxSample)     /* Stat4Accum.aBest[], a[] */
+    + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample)
+#endif
+  ;
+  db = sqlite3_context_db_handle(context);
+  p = sqlite3DbMallocZero(db, n);
   if( p==0 ){
     sqlite3_result_error_nomem(context);
     return;
   }
-  memset(p, 0, n);
-  p->a = (struct Stat3Sample*)&p[1];
-  p->nRow = nRow;
-  p->mxSample = mxSample;
-  p->nPSample = p->nRow/(mxSample/3+1) + 1;
-  sqlite3_randomness(sizeof(p->iPrn), &p->iPrn);
-  sqlite3_result_blob(context, p, sizeof(p), sqlite3_free);
-}
-static const FuncDef stat3InitFuncdef = {
-  2,                /* nArg */
-  SQLITE_UTF8,      /* iPrefEnc */
-  0,                /* flags */
-  0,                /* pUserData */
-  0,                /* pNext */
-  stat3Init,        /* xFunc */
-  0,                /* xStep */
-  0,                /* xFinalize */
-  "stat3_init",     /* zName */
-  0,                /* pHash */
-  0                 /* pDestructor */
+
+  p->db = db;
+  p->nRow = 0;
+  p->nCol = nCol;
+  p->nKeyCol = nKeyCol;
+  p->current.anDLt = (tRowcnt*)&p[1];
+  p->current.anEq = &p->current.anDLt[nColUp];
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  {
+    u8 *pSpace;                     /* Allocated space not yet assigned */
+    int i;                          /* Used to iterate through p->aSample[] */
+
+    p->iGet = -1;
+    p->mxSample = mxSample;
+    p->nPSample = (tRowcnt)(sqlite3_value_int64(argv[2])/(mxSample/3+1) + 1);
+    p->current.anLt = &p->current.anEq[nColUp];
+    p->iPrn = 0x689e962d*(u32)nCol ^ 0xd0944565*(u32)sqlite3_value_int(argv[2]);
+  
+    /* Set up the Stat4Accum.a[] and aBest[] arrays */
+    p->a = (struct Stat4Sample*)&p->current.anLt[nColUp];
+    p->aBest = &p->a[mxSample];
+    pSpace = (u8*)(&p->a[mxSample+nCol]);
+    for(i=0; i<(mxSample+nCol); i++){
+      p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
+      p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
+      p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);
+    }
+    assert( (pSpace - (u8*)p)==n );
+  
+    for(i=0; i<nCol; i++){
+      p->aBest[i].iCol = i;
+    }
+  }
+#endif
+
+  /* Return a pointer to the allocated object to the caller.  Note that
+  ** only the pointer (the 2nd parameter) matters.  The size of the object
+  ** (given by the 3rd parameter) is never used and can be any positive
+  ** value. */
+  sqlite3_result_blob(context, p, sizeof(*p), stat4Destructor);
+}
+static const FuncDef statInitFuncdef = {
+  2+IsStat34,      /* nArg */
+  SQLITE_UTF8,     /* funcFlags */
+  0,               /* pUserData */
+  0,               /* pNext */
+  statInit,        /* xSFunc */
+  0,               /* xFinalize */
+  "stat_init",     /* zName */
+  {0}
 };
 
+#ifdef SQLITE_ENABLE_STAT4
+/*
+** pNew and pOld are both candidate non-periodic samples selected for 
+** the same column (pNew->iCol==pOld->iCol). Ignoring this column and 
+** considering only any trailing columns and the sample hash value, this
+** function returns true if sample pNew is to be preferred over pOld.
+** In other words, if we assume that the cardinalities of the selected
+** column for pNew and pOld are equal, is pNew to be preferred over pOld.
+**
+** This function assumes that for each argument sample, the contents of
+** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. 
+*/
+static int sampleIsBetterPost(
+  Stat4Accum *pAccum, 
+  Stat4Sample *pNew, 
+  Stat4Sample *pOld
+){
+  int nCol = pAccum->nCol;
+  int i;
+  assert( pNew->iCol==pOld->iCol );
+  for(i=pNew->iCol+1; i<nCol; i++){
+    if( pNew->anEq[i]>pOld->anEq[i] ) return 1;
+    if( pNew->anEq[i]<pOld->anEq[i] ) return 0;
+  }
+  if( pNew->iHash>pOld->iHash ) return 1;
+  return 0;
+}
+#endif
 
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
-** Implementation of the stat3_push(nEq,nLt,nDLt,rowid,P) SQL function.  The
-** arguments describe a single key instance.  This routine makes the 
-** decision about whether or not to retain this key for the sqlite_stat3
-** table.
+** Return true if pNew is to be preferred over pOld.
 **
-** The return value is NULL.
+** This function assumes that for each argument sample, the contents of
+** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. 
 */
-static void stat3Push(
+static int sampleIsBetter(
+  Stat4Accum *pAccum, 
+  Stat4Sample *pNew, 
+  Stat4Sample *pOld
+){
+  tRowcnt nEqNew = pNew->anEq[pNew->iCol];
+  tRowcnt nEqOld = pOld->anEq[pOld->iCol];
+
+  assert( pOld->isPSample==0 && pNew->isPSample==0 );
+  assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) );
+
+  if( (nEqNew>nEqOld) ) return 1;
+#ifdef SQLITE_ENABLE_STAT4
+  if( nEqNew==nEqOld ){
+    if( pNew->iCol<pOld->iCol ) return 1;
+    return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld));
+  }
+  return 0;
+#else
+  return (nEqNew==nEqOld && pNew->iHash>pOld->iHash);
+#endif
+}
+
+/*
+** Copy the contents of sample *pNew into the p->a[] array. If necessary,
+** remove the least desirable sample from p->a[] to make room.
+*/
+static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){
+  Stat4Sample *pSample = 0;
+  int i;
+
+  assert( IsStat4 || nEqZero==0 );
+
+#ifdef SQLITE_ENABLE_STAT4
+  if( pNew->isPSample==0 ){
+    Stat4Sample *pUpgrade = 0;
+    assert( pNew->anEq[pNew->iCol]>0 );
+
+    /* This sample is being added because the prefix that ends in column 
+    ** iCol occurs many times in the table. However, if we have already
+    ** added a sample that shares this prefix, there is no need to add
+    ** this one. Instead, upgrade the priority of the highest priority
+    ** existing sample that shares this prefix.  */
+    for(i=p->nSample-1; i>=0; i--){
+      Stat4Sample *pOld = &p->a[i];
+      if( pOld->anEq[pNew->iCol]==0 ){
+        if( pOld->isPSample ) return;
+        assert( pOld->iCol>pNew->iCol );
+        assert( sampleIsBetter(p, pNew, pOld) );
+        if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){
+          pUpgrade = pOld;
+        }
+      }
+    }
+    if( pUpgrade ){
+      pUpgrade->iCol = pNew->iCol;
+      pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol];
+      goto find_new_min;
+    }
+  }
+#endif
+
+  /* If necessary, remove sample iMin to make room for the new sample. */
+  if( p->nSample>=p->mxSample ){
+    Stat4Sample *pMin = &p->a[p->iMin];
+    tRowcnt *anEq = pMin->anEq;
+    tRowcnt *anLt = pMin->anLt;
+    tRowcnt *anDLt = pMin->anDLt;
+    sampleClear(p->db, pMin);
+    memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1));
+    pSample = &p->a[p->nSample-1];
+    pSample->nRowid = 0;
+    pSample->anEq = anEq;
+    pSample->anDLt = anDLt;
+    pSample->anLt = anLt;
+    p->nSample = p->mxSample-1;
+  }
+
+  /* The "rows less-than" for the rowid column must be greater than that
+  ** for the last sample in the p->a[] array. Otherwise, the samples would
+  ** be out of order. */
+#ifdef SQLITE_ENABLE_STAT4
+  assert( p->nSample==0 
+       || pNew->anLt[p->nCol-1] > p->a[p->nSample-1].anLt[p->nCol-1] );
+#endif
+
+  /* Insert the new sample */
+  pSample = &p->a[p->nSample];
+  sampleCopy(p, pSample, pNew);
+  p->nSample++;
+
+  /* Zero the first nEqZero entries in the anEq[] array. */
+  memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero);
+
+#ifdef SQLITE_ENABLE_STAT4
+ find_new_min:
+#endif
+  if( p->nSample>=p->mxSample ){
+    int iMin = -1;
+    for(i=0; i<p->mxSample; i++){
+      if( p->a[i].isPSample ) continue;
+      if( iMin<0 || sampleIsBetter(p, &p->a[iMin], &p->a[i]) ){
+        iMin = i;
+      }
+    }
+    assert( iMin>=0 );
+    p->iMin = iMin;
+  }
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** Field iChng of the index being scanned has changed. So at this point
+** p->current contains a sample that reflects the previous row of the
+** index. The value of anEq[iChng] and subsequent anEq[] elements are
+** correct at this point.
+*/
+static void samplePushPrevious(Stat4Accum *p, int iChng){
+#ifdef SQLITE_ENABLE_STAT4
+  int i;
+
+  /* Check if any samples from the aBest[] array should be pushed
+  ** into IndexSample.a[] at this point.  */
+  for(i=(p->nCol-2); i>=iChng; i--){
+    Stat4Sample *pBest = &p->aBest[i];
+    pBest->anEq[i] = p->current.anEq[i];
+    if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){
+      sampleInsert(p, pBest, i);
+    }
+  }
+
+  /* Update the anEq[] fields of any samples already collected. */
+  for(i=p->nSample-1; i>=0; i--){
+    int j;
+    for(j=iChng; j<p->nCol; j++){
+      if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];
+    }
+  }
+#endif
+
+#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4)
+  if( iChng==0 ){
+    tRowcnt nLt = p->current.anLt[0];
+    tRowcnt nEq = p->current.anEq[0];
+
+    /* Check if this is to be a periodic sample. If so, add it. */
+    if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){
+      p->current.isPSample = 1;
+      sampleInsert(p, &p->current, 0);
+      p->current.isPSample = 0;
+    }else 
+
+    /* Or if it is a non-periodic sample. Add it in this case too. */
+    if( p->nSample<p->mxSample 
+     || sampleIsBetter(p, &p->current, &p->a[p->iMin]) 
+    ){
+      sampleInsert(p, &p->current, 0);
+    }
+  }
+#endif
+
+#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
+  UNUSED_PARAMETER( p );
+  UNUSED_PARAMETER( iChng );
+#endif
+}
+
+/*
+** Implementation of the stat_push SQL function:  stat_push(P,C,R)
+** Arguments:
+**
+**    P     Pointer to the Stat4Accum object created by stat_init()
+**    C     Index of left-most column to differ from previous row
+**    R     Rowid for the current row.  Might be a key record for
+**          WITHOUT ROWID tables.
+**
+** This SQL function always returns NULL.  It's purpose it to accumulate
+** statistical data and/or samples in the Stat4Accum object about the
+** index being analyzed.  The stat_get() SQL function will later be used to
+** extract relevant information for constructing the sqlite_statN tables.
+**
+** The R parameter is only used for STAT3 and STAT4
+*/
+static void statPush(
   sqlite3_context *context,
   int argc,
   sqlite3_value **argv
 ){
-  Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[4]);
-  tRowcnt nEq = sqlite3_value_int64(argv[0]);
-  tRowcnt nLt = sqlite3_value_int64(argv[1]);
-  tRowcnt nDLt = sqlite3_value_int64(argv[2]);
-  i64 rowid = sqlite3_value_int64(argv[3]);
-  u8 isPSample = 0;
-  u8 doInsert = 0;
-  int iMin = p->iMin;
-  struct Stat3Sample *pSample;
   int i;
-  u32 h;
 
-  UNUSED_PARAMETER(context);
-  UNUSED_PARAMETER(argc);
-  if( nEq==0 ) return;
-  h = p->iPrn = p->iPrn*1103515245 + 12345;
-  if( (nLt/p->nPSample)!=((nEq+nLt)/p->nPSample) ){
-    doInsert = isPSample = 1;
-  }else if( p->nSample<p->mxSample ){
-    doInsert = 1;
+  /* The three function arguments */
+  Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);
+  int iChng = sqlite3_value_int(argv[1]);
+
+  UNUSED_PARAMETER( argc );
+  UNUSED_PARAMETER( context );
+  assert( p->nCol>0 );
+  assert( iChng<p->nCol );
+
+  if( p->nRow==0 ){
+    /* This is the first call to this function. Do initialization. */
+    for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1;
   }else{
-    if( nEq>p->a[iMin].nEq || (nEq==p->a[iMin].nEq && h>p->a[iMin].iHash) ){
-      doInsert = 1;
+    /* Second and subsequent calls get processed here */
+    samplePushPrevious(p, iChng);
+
+    /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply
+    ** to the current row of the index. */
+    for(i=0; i<iChng; i++){
+      p->current.anEq[i]++;
+    }
+    for(i=iChng; i<p->nCol; i++){
+      p->current.anDLt[i]++;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+      p->current.anLt[i] += p->current.anEq[i];
+#endif
+      p->current.anEq[i] = 1;
     }
   }
-  if( !doInsert ) return;
-  if( p->nSample==p->mxSample ){
-    assert( p->nSample - iMin - 1 >= 0 );
-    memmove(&p->a[iMin], &p->a[iMin+1], sizeof(p->a[0])*(p->nSample-iMin-1));
-    pSample = &p->a[p->nSample-1];
+  p->nRow++;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){
+    sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2]));
   }else{
-    pSample = &p->a[p->nSample++];
+    sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]),
+                                       sqlite3_value_blob(argv[2]));
   }
-  pSample->iRowid = rowid;
-  pSample->nEq = nEq;
-  pSample->nLt = nLt;
-  pSample->nDLt = nDLt;
-  pSample->iHash = h;
-  pSample->isPSample = isPSample;
+  p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345;
+#endif
 
-  /* Find the new minimum */
-  if( p->nSample==p->mxSample ){
-    pSample = p->a;
-    i = 0;
-    while( pSample->isPSample ){
-      i++;
-      pSample++;
-      assert( i<p->nSample );
-    }
-    nEq = pSample->nEq;
-    h = pSample->iHash;
-    iMin = i;
-    for(i++, pSample++; i<p->nSample; i++, pSample++){
-      if( pSample->isPSample ) continue;
-      if( pSample->nEq<nEq
-       || (pSample->nEq==nEq && pSample->iHash<h)
-      ){
-        iMin = i;
-        nEq = pSample->nEq;
-        h = pSample->iHash;
+#ifdef SQLITE_ENABLE_STAT4
+  {
+    tRowcnt nLt = p->current.anLt[p->nCol-1];
+
+    /* Check if this is to be a periodic sample. If so, add it. */
+    if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){
+      p->current.isPSample = 1;
+      p->current.iCol = 0;
+      sampleInsert(p, &p->current, p->nCol-1);
+      p->current.isPSample = 0;
+    }
+
+    /* Update the aBest[] array. */
+    for(i=0; i<(p->nCol-1); i++){
+      p->current.iCol = i;
+      if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){
+        sampleCopy(p, &p->aBest[i], &p->current);
       }
     }
-    p->iMin = iMin;
   }
+#endif
 }
-static const FuncDef stat3PushFuncdef = {
-  5,                /* nArg */
-  SQLITE_UTF8,      /* iPrefEnc */
-  0,                /* flags */
-  0,                /* pUserData */
-  0,                /* pNext */
-  stat3Push,        /* xFunc */
-  0,                /* xStep */
-  0,                /* xFinalize */
-  "stat3_push",     /* zName */
-  0,                /* pHash */
-  0                 /* pDestructor */
+static const FuncDef statPushFuncdef = {
+  2+IsStat34,      /* nArg */
+  SQLITE_UTF8,     /* funcFlags */
+  0,               /* pUserData */
+  0,               /* pNext */
+  statPush,        /* xSFunc */
+  0,               /* xFinalize */
+  "stat_push",     /* zName */
+  {0}
 };
 
+#define STAT_GET_STAT1 0          /* "stat" column of stat1 table */
+#define STAT_GET_ROWID 1          /* "rowid" column of stat[34] entry */
+#define STAT_GET_NEQ   2          /* "neq" column of stat[34] entry */
+#define STAT_GET_NLT   3          /* "nlt" column of stat[34] entry */
+#define STAT_GET_NDLT  4          /* "ndlt" column of stat[34] entry */
+
 /*
-** Implementation of the stat3_get(P,N,...) SQL function.  This routine is
-** used to query the results.  Content is returned for the Nth sqlite_stat3
-** row where N is between 0 and S-1 and S is the number of samples.  The
-** value returned depends on the number of arguments.
+** Implementation of the stat_get(P,J) SQL function.  This routine is
+** used to query statistical information that has been gathered into
+** the Stat4Accum object by prior calls to stat_push().  The P parameter
+** has type BLOB but it is really just a pointer to the Stat4Accum object.
+** The content to returned is determined by the parameter J
+** which is one of the STAT_GET_xxxx values defined above.
 **
-**   argc==2    result:  rowid
-**   argc==3    result:  nEq
-**   argc==4    result:  nLt
-**   argc==5    result:  nDLt
+** If neither STAT3 nor STAT4 are enabled, then J is always
+** STAT_GET_STAT1 and is hence omitted and this routine becomes
+** a one-parameter function, stat_get(P), that always returns the
+** stat1 table entry information.
 */
-static void stat3Get(
+static void statGet(
   sqlite3_context *context,
   int argc,
   sqlite3_value **argv
 ){
-  int n = sqlite3_value_int(argv[1]);
-  Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[0]);
+  Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  /* STAT3 and STAT4 have a parameter on this routine. */
+  int eCall = sqlite3_value_int(argv[1]);
+  assert( argc==2 );
+  assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ 
+       || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT
+       || eCall==STAT_GET_NDLT 
+  );
+  if( eCall==STAT_GET_STAT1 )
+#else
+  assert( argc==1 );
+#endif
+  {
+    /* Return the value to store in the "stat" column of the sqlite_stat1
+    ** table for this index.
+    **
+    ** The value is a string composed of a list of integers describing 
+    ** the index. The first integer in the list is the total number of 
+    ** entries in the index. There is one additional integer in the list 
+    ** for each indexed column. This additional integer is an estimate of
+    ** the number of rows matched by a stabbing query on the index using
+    ** a key with the corresponding number of fields. In other words,
+    ** if the index is on columns (a,b) and the sqlite_stat1 value is 
+    ** "100 10 2", then SQLite estimates that:
+    **
+    **   * the index contains 100 rows,
+    **   * "WHERE a=?" matches 10 rows, and
+    **   * "WHERE a=? AND b=?" matches 2 rows.
+    **
+    ** If D is the count of distinct values and K is the total number of 
+    ** rows, then each estimate is computed as:
+    **
+    **        I = (K+D-1)/D
+    */
+    char *z;
+    int i;
 
-  assert( p!=0 );
-  if( p->nSample<=n ) return;
-  switch( argc ){
-    case 2:  sqlite3_result_int64(context, p->a[n].iRowid); break;
-    case 3:  sqlite3_result_int64(context, p->a[n].nEq);    break;
-    case 4:  sqlite3_result_int64(context, p->a[n].nLt);    break;
-    default: sqlite3_result_int64(context, p->a[n].nDLt);   break;
-  }
-}
-static const FuncDef stat3GetFuncdef = {
-  -1,               /* nArg */
-  SQLITE_UTF8,      /* iPrefEnc */
-  0,                /* flags */
-  0,                /* pUserData */
-  0,                /* pNext */
-  stat3Get,         /* xFunc */
-  0,                /* xStep */
-  0,                /* xFinalize */
-  "stat3_get",     /* zName */
-  0,                /* pHash */
-  0                 /* pDestructor */
-};
-#endif /* SQLITE_ENABLE_STAT3 */
+    char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );
+    if( zRet==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
 
+    sqlite3_snprintf(24, zRet, "%llu", (u64)p->nRow);
+    z = zRet + sqlite3Strlen30(zRet);
+    for(i=0; i<p->nKeyCol; i++){
+      u64 nDistinct = p->current.anDLt[i] + 1;
+      u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
+      sqlite3_snprintf(24, z, " %llu", iVal);
+      z += sqlite3Strlen30(z);
+      assert( p->current.anEq[i] );
+    }
+    assert( z[0]=='\0' && z>zRet );
 
+    sqlite3_result_text(context, zRet, -1, sqlite3_free);
+  }
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  else if( eCall==STAT_GET_ROWID ){
+    if( p->iGet<0 ){
+      samplePushPrevious(p, 0);
+      p->iGet = 0;
+    }
+    if( p->iGet<p->nSample ){
+      Stat4Sample *pS = p->a + p->iGet;
+      if( pS->nRowid==0 ){
+        sqlite3_result_int64(context, pS->u.iRowid);
+      }else{
+        sqlite3_result_blob(context, pS->u.aRowid, pS->nRowid,
+                            SQLITE_TRANSIENT);
+      }
+    }
+  }else{
+    tRowcnt *aCnt = 0;
+
+    assert( p->iGet<p->nSample );
+    switch( eCall ){
+      case STAT_GET_NEQ:  aCnt = p->a[p->iGet].anEq; break;
+      case STAT_GET_NLT:  aCnt = p->a[p->iGet].anLt; break;
+      default: {
+        aCnt = p->a[p->iGet].anDLt; 
+        p->iGet++;
+        break;
+      }
+    }
+
+    if( IsStat3 ){
+      sqlite3_result_int64(context, (i64)aCnt[0]);
+    }else{
+      char *zRet = sqlite3MallocZero(p->nCol * 25);
+      if( zRet==0 ){
+        sqlite3_result_error_nomem(context);
+      }else{
+        int i;
+        char *z = zRet;
+        for(i=0; i<p->nCol; i++){
+          sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]);
+          z += sqlite3Strlen30(z);
+        }
+        assert( z[0]=='\0' && z>zRet );
+        z[-1] = '\0';
+        sqlite3_result_text(context, zRet, -1, sqlite3_free);
+      }
+    }
+  }
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER( argc );
+#endif
+}
+static const FuncDef statGetFuncdef = {
+  1+IsStat34,      /* nArg */
+  SQLITE_UTF8,     /* funcFlags */
+  0,               /* pUserData */
+  0,               /* pNext */
+  statGet,         /* xSFunc */
+  0,               /* xFinalize */
+  "stat_get",      /* zName */
+  {0}
+};
 
+static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){
+  assert( regOut!=regStat4 && regOut!=regStat4+1 );
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1);
+#elif SQLITE_DEBUG
+  assert( iParam==STAT_GET_STAT1 );
+#else
+  UNUSED_PARAMETER( iParam );
+#endif
+  sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4, regOut,
+                    (char*)&statGetFuncdef, P4_FUNCDEF);
+  sqlite3VdbeChangeP5(v, 1 + IsStat34);
+}
 
 /*
 ** Generate code to do an analysis of all indices associated with
@@ -77940,41 +95600,31 @@ static void analyzeOneTable(
   Table *pTab,     /* Table whose indices are to be analyzed */
   Index *pOnlyIdx, /* If not NULL, only analyze this one index */
   int iStatCur,    /* Index of VdbeCursor that writes the sqlite_stat1 table */
-  int iMem         /* Available memory locations begin here */
+  int iMem,        /* Available memory locations begin here */
+  int iTab         /* Next available cursor */
 ){
   sqlite3 *db = pParse->db;    /* Database handle */
   Index *pIdx;                 /* An index to being analyzed */
   int iIdxCur;                 /* Cursor open on index being analyzed */
+  int iTabCur;                 /* Table cursor */
   Vdbe *v;                     /* The virtual machine being built up */
   int i;                       /* Loop counter */
-  int topOfLoop;               /* The top of the loop */
-  int endOfLoop;               /* The end of the loop */
   int jZeroRows = -1;          /* Jump from here if number of rows is zero */
   int iDb;                     /* Index of database containing pTab */
+  u8 needTableCnt = 1;         /* True to count the table */
+  int regNewRowid = iMem++;    /* Rowid for the inserted record */
+  int regStat4 = iMem++;       /* Register to hold Stat4Accum object */
+  int regChng = iMem++;        /* Index of changed index field */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  int regRowid = iMem++;       /* Rowid argument passed to stat_push() */
+#endif
+  int regTemp = iMem++;        /* Temporary use register */
   int regTabname = iMem++;     /* Register containing table name */
   int regIdxname = iMem++;     /* Register containing index name */
-  int regStat1 = iMem++;       /* The stat column of sqlite_stat1 */
-#ifdef SQLITE_ENABLE_STAT3
-  int regNumEq = regStat1;     /* Number of instances.  Same as regStat1 */
-  int regNumLt = iMem++;       /* Number of keys less than regSample */
-  int regNumDLt = iMem++;      /* Number of distinct keys less than regSample */
-  int regSample = iMem++;      /* The next sample value */
-  int regRowid = regSample;    /* Rowid of a sample */
-  int regAccum = iMem++;       /* Register to hold Stat3Accum object */
-  int regLoop = iMem++;        /* Loop counter */
-  int regCount = iMem++;       /* Number of rows in the table or index */
-  int regTemp1 = iMem++;       /* Intermediate register */
-  int regTemp2 = iMem++;       /* Intermediate register */
-  int once = 1;                /* One-time initialization */
-  int shortJump = 0;           /* Instruction address */
-  int iTabCur = pParse->nTab++; /* Table cursor */
-#endif
-  int regCol = iMem++;         /* Content of a column in analyzed table */
-  int regRec = iMem++;         /* Register holding completed record */
-  int regTemp = iMem++;        /* Temporary use register */
-  int regNewRowid = iMem++;    /* Rowid for the inserted record */
-
+  int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */
+  int regPrev = iMem;          /* MUST BE LAST (see below) */
 
+  pParse->nMem = MAX(pParse->nMem, iMem);
   v = sqlite3GetVdbe(pParse);
   if( v==0 || NEVER(pTab==0) ){
     return;
@@ -77983,7 +95633,7 @@ static void analyzeOneTable(
     /* Do not gather statistics on views or virtual tables */
     return;
   }
-  if( memcmp(pTab->zName, "sqlite_", 7)==0 ){
+  if( sqlite3_strlike("sqlite_%", pTab->zName, 0)==0 ){
     /* Do not gather statistics on system tables */
     return;
   }
@@ -77998,214 +95648,272 @@ static void analyzeOneTable(
   }
 #endif
 
-  /* Establish a read-lock on the table at the shared-cache level. */
+  /* Establish a read-lock on the table at the shared-cache level. 
+  ** Open a read-only cursor on the table. Also allocate a cursor number
+  ** to use for scanning indexes (iIdxCur). No index cursor is opened at
+  ** this time though.  */
   sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+  iTabCur = iTab++;
+  iIdxCur = iTab++;
+  pParse->nTab = MAX(pParse->nTab, iTab);
+  sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
+  sqlite3VdbeLoadString(v, regTabname, pTab->zName);
 
-  iIdxCur = pParse->nTab++;
-  sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-    int nCol;
-    KeyInfo *pKey;
-    int addrIfNot = 0;           /* address of OP_IfNot */
-    int *aChngAddr;              /* Array of jump instruction addresses */
+    int nCol;                     /* Number of columns in pIdx. "N" */
+    int addrRewind;               /* Address of "OP_Rewind iIdxCur" */
+    int addrNextRow;              /* Address of "next_row:" */
+    const char *zIdxName;         /* Name of the index */
+    int nColTest;                 /* Number of columns to test for changes */
 
     if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
-    VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName));
-    nCol = pIdx->nColumn;
-    aChngAddr = sqlite3DbMallocRaw(db, sizeof(int)*nCol);
-    if( aChngAddr==0 ) continue;
-    pKey = sqlite3IndexKeyinfo(pParse, pIdx);
-    if( iMem+1+(nCol*2)>pParse->nMem ){
-      pParse->nMem = iMem+1+(nCol*2);
+    if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;
+    if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){
+      nCol = pIdx->nKeyCol;
+      zIdxName = pTab->zName;
+      nColTest = nCol - 1;
+    }else{
+      nCol = pIdx->nColumn;
+      zIdxName = pIdx->zName;
+      nColTest = pIdx->uniqNotNull ? pIdx->nKeyCol-1 : nCol-1;
     }
 
-    /* Open a cursor to the index to be analyzed. */
-    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
-    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
-        (char *)pKey, P4_KEYINFO_HANDOFF);
-    VdbeComment((v, "%s", pIdx->zName));
-
     /* Populate the register containing the index name. */
-    sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);
+    sqlite3VdbeLoadString(v, regIdxname, zIdxName);
+    VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName));
 
-#ifdef SQLITE_ENABLE_STAT3
-    if( once ){
-      once = 0;
-      sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
-    }
-    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regCount);
-    sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES, regTemp1);
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumEq);
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumLt);
-    sqlite3VdbeAddOp2(v, OP_Integer, -1, regNumDLt);
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regCount, regAccum,
-                      (char*)&stat3InitFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 2);
-#endif /* SQLITE_ENABLE_STAT3 */
-
-    /* The block of memory cells initialized here is used as follows.
+    /*
+    ** Pseudo-code for loop that calls stat_push():
+    **
+    **   Rewind csr
+    **   if eof(csr) goto end_of_scan;
+    **   regChng = 0
+    **   goto chng_addr_0;
     **
-    **    iMem:                
-    **        The total number of rows in the table.
+    **  next_row:
+    **   regChng = 0
+    **   if( idx(0) != regPrev(0) ) goto chng_addr_0
+    **   regChng = 1
+    **   if( idx(1) != regPrev(1) ) goto chng_addr_1
+    **   ...
+    **   regChng = N
+    **   goto chng_addr_N
     **
-    **    iMem+1 .. iMem+nCol: 
-    **        Number of distinct entries in index considering the 
-    **        left-most N columns only, where N is between 1 and nCol, 
-    **        inclusive.
+    **  chng_addr_0:
+    **   regPrev(0) = idx(0)
+    **  chng_addr_1:
+    **   regPrev(1) = idx(1)
+    **  ...
     **
-    **    iMem+nCol+1 .. Mem+2*nCol:  
-    **        Previous value of indexed columns, from left to right.
+    **  endDistinctTest:
+    **   regRowid = idx(rowid)
+    **   stat_push(P, regChng, regRowid)
+    **   Next csr
+    **   if !eof(csr) goto next_row;
     **
-    ** Cells iMem through iMem+nCol are initialized to 0. The others are 
-    ** initialized to contain an SQL NULL.
+    **  end_of_scan:
     */
-    for(i=0; i<=nCol; i++){
-      sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i);
-    }
-    for(i=0; i<nCol; i++){
-      sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1);
-    }
 
-    /* Start the analysis loop. This loop runs through all the entries in
-    ** the index b-tree.  */
-    endOfLoop = sqlite3VdbeMakeLabel(v);
-    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
-    topOfLoop = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);  /* Increment row counter */
+    /* Make sure there are enough memory cells allocated to accommodate 
+    ** the regPrev array and a trailing rowid (the rowid slot is required
+    ** when building a record to insert into the sample column of 
+    ** the sqlite_stat4 table.  */
+    pParse->nMem = MAX(pParse->nMem, regPrev+nColTest);
 
-    for(i=0; i<nCol; i++){
-      CollSeq *pColl;
-      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol);
-      if( i==0 ){
-        /* Always record the very first row */
-        addrIfNot = sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1);
-      }
-      assert( pIdx->azColl!=0 );
-      assert( pIdx->azColl[i]!=0 );
-      pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
-      aChngAddr[i] = sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1,
-                                      (char*)pColl, P4_COLLSEQ);
-      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
-      VdbeComment((v, "jump if column %d changed", i));
-#ifdef SQLITE_ENABLE_STAT3
-      if( i==0 ){
-        sqlite3VdbeAddOp2(v, OP_AddImm, regNumEq, 1);
-        VdbeComment((v, "incr repeat count"));
-      }
-#endif
-    }
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
-    for(i=0; i<nCol; i++){
-      sqlite3VdbeJumpHere(v, aChngAddr[i]);  /* Set jump dest for the OP_Ne */
-      if( i==0 ){
-        sqlite3VdbeJumpHere(v, addrIfNot);   /* Jump dest for OP_IfNot */
-#ifdef SQLITE_ENABLE_STAT3
-        sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
-                          (char*)&stat3PushFuncdef, P4_FUNCDEF);
-        sqlite3VdbeChangeP5(v, 5);
-        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, pIdx->nColumn, regRowid);
-        sqlite3VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regNumLt);
-        sqlite3VdbeAddOp2(v, OP_AddImm, regNumDLt, 1);
-        sqlite3VdbeAddOp2(v, OP_Integer, 1, regNumEq);
-#endif        
-      }
-      sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
-      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
-    }
-    sqlite3DbFree(db, aChngAddr);
-
-    /* Always jump here after updating the iMem+1...iMem+1+nCol counters */
-    sqlite3VdbeResolveLabel(v, endOfLoop);
+    /* Open a read-only cursor on the index being analyzed. */
+    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
+    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb);
+    sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+    VdbeComment((v, "%s", pIdx->zName));
 
-    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
-    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
-#ifdef SQLITE_ENABLE_STAT3
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
-                      (char*)&stat3PushFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 5);
-    sqlite3VdbeAddOp2(v, OP_Integer, -1, regLoop);
-    shortJump = 
-    sqlite3VdbeAddOp2(v, OP_AddImm, regLoop, 1);
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regTemp1,
-                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 2);
-    sqlite3VdbeAddOp1(v, OP_IsNull, regTemp1);
-    sqlite3VdbeAddOp3(v, OP_NotExists, iTabCur, shortJump, regTemp1);
-    sqlite3VdbeAddOp3(v, OP_Column, iTabCur, pIdx->aiColumn[0], regSample);
-    sqlite3ColumnDefault(v, pTab, pIdx->aiColumn[0], regSample);
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumEq,
-                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 3);
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumLt,
-                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 4);
-    sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumDLt,
-                      (char*)&stat3GetFuncdef, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, 5);
-    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 6, regRec, "bbbbbb", 0);
-    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
-    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regNewRowid);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, shortJump);
-    sqlite3VdbeJumpHere(v, shortJump+2);
-#endif        
-
-    /* Store the results in sqlite_stat1.
+    /* Invoke the stat_init() function. The arguments are:
+    ** 
+    **    (1) the number of columns in the index including the rowid
+    **        (or for a WITHOUT ROWID table, the number of PK columns),
+    **    (2) the number of columns in the key without the rowid/pk
+    **    (3) the number of rows in the index,
     **
-    ** The result is a single row of the sqlite_stat1 table.  The first
-    ** two columns are the names of the table and index.  The third column
-    ** is a string composed of a list of integer statistics about the
-    ** index.  The first integer in the list is the total number of entries
-    ** in the index.  There is one additional integer in the list for each
-    ** column of the table.  This additional integer is a guess of how many
-    ** rows of the table the index will select.  If D is the count of distinct
-    ** values and K is the total number of rows, then the integer is computed
-    ** as:
     **
-    **        I = (K+D-1)/D
+    ** The third argument is only used for STAT3 and STAT4
+    */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3);
+#endif
+    sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1);
+    sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2);
+    sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4+1, regStat4,
+                     (char*)&statInitFuncdef, P4_FUNCDEF);
+    sqlite3VdbeChangeP5(v, 2+IsStat34);
+
+    /* Implementation of the following:
+    **
+    **   Rewind csr
+    **   if eof(csr) goto end_of_scan;
+    **   regChng = 0
+    **   goto next_push_0;
     **
-    ** If K==0 then no entry is made into the sqlite_stat1 table.  
-    ** If K>0 then it is always the case the D>0 so division by zero
-    ** is never possible.
     */
-    sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regStat1);
-    if( jZeroRows<0 ){
-      jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
+    addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
+    VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
+    addrNextRow = sqlite3VdbeCurrentAddr(v);
+
+    if( nColTest>0 ){
+      int endDistinctTest = sqlite3VdbeMakeLabel(v);
+      int *aGotoChng;               /* Array of jump instruction addresses */
+      aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);
+      if( aGotoChng==0 ) continue;
+
+      /*
+      **  next_row:
+      **   regChng = 0
+      **   if( idx(0) != regPrev(0) ) goto chng_addr_0
+      **   regChng = 1
+      **   if( idx(1) != regPrev(1) ) goto chng_addr_1
+      **   ...
+      **   regChng = N
+      **   goto endDistinctTest
+      */
+      sqlite3VdbeAddOp0(v, OP_Goto);
+      addrNextRow = sqlite3VdbeCurrentAddr(v);
+      if( nColTest==1 && pIdx->nKeyCol==1 && IsUniqueIndex(pIdx) ){
+        /* For a single-column UNIQUE index, once we have found a non-NULL
+        ** row, we know that all the rest will be distinct, so skip 
+        ** subsequent distinctness tests. */
+        sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest);
+        VdbeCoverage(v);
+      }
+      for(i=0; i<nColTest; i++){
+        char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
+        sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);
+        aGotoChng[i] = 
+        sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);
+        sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+        VdbeCoverage(v);
+      }
+      sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);
+      sqlite3VdbeGoto(v, endDistinctTest);
+  
+  
+      /*
+      **  chng_addr_0:
+      **   regPrev(0) = idx(0)
+      **  chng_addr_1:
+      **   regPrev(1) = idx(1)
+      **  ...
+      */
+      sqlite3VdbeJumpHere(v, addrNextRow-1);
+      for(i=0; i<nColTest; i++){
+        sqlite3VdbeJumpHere(v, aGotoChng[i]);
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
+      }
+      sqlite3VdbeResolveLabel(v, endDistinctTest);
+      sqlite3DbFree(db, aGotoChng);
     }
-    for(i=0; i<nCol; i++){
-      sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
-      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
-      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
-      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
-      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
-      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
-      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
-    }
-    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
+  
+    /*
+    **  chng_addr_N:
+    **   regRowid = idx(rowid)            // STAT34 only
+    **   stat_push(P, regChng, regRowid)  // 3rd parameter STAT34 only
+    **   Next csr
+    **   if !eof(csr) goto next_row;
+    */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    assert( regRowid==(regStat4+2) );
+    if( HasRowid(pTab) ){
+      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);
+    }else{
+      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
+      int j, k, regKey;
+      regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);
+      for(j=0; j<pPk->nKeyCol; j++){
+        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        assert( k>=0 && k<pTab->nCol );
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);
+        VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));
+      }
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);
+      sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);
+    }
+#endif
+    assert( regChng==(regStat4+1) );
+    sqlite3VdbeAddOp4(v, OP_Function0, 1, regStat4, regTemp,
+                     (char*)&statPushFuncdef, P4_FUNCDEF);
+    sqlite3VdbeChangeP5(v, 2+IsStat34);
+    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);
+
+    /* Add the entry to the stat1 table. */
+    callStatGet(v, regStat4, STAT_GET_STAT1, regStat1);
+    assert( "BBB"[0]==SQLITE_AFF_TEXT );
+    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);
     sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
-    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);
     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+
+    /* Add the entries to the stat3 or stat4 table. */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    {
+      int regEq = regStat1;
+      int regLt = regStat1+1;
+      int regDLt = regStat1+2;
+      int regSample = regStat1+3;
+      int regCol = regStat1+4;
+      int regSampleRowid = regCol + nCol;
+      int addrNext;
+      int addrIsNull;
+      u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
+
+      pParse->nMem = MAX(pParse->nMem, regCol+nCol);
+
+      addrNext = sqlite3VdbeCurrentAddr(v);
+      callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid);
+      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
+      VdbeCoverage(v);
+      callStatGet(v, regStat4, STAT_GET_NEQ, regEq);
+      callStatGet(v, regStat4, STAT_GET_NLT, regLt);
+      callStatGet(v, regStat4, STAT_GET_NDLT, regDLt);
+      sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0);
+      /* We know that the regSampleRowid row exists because it was read by
+      ** the previous loop.  Thus the not-found jump of seekOp will never
+      ** be taken */
+      VdbeCoverageNeverTaken(v);
+#ifdef SQLITE_ENABLE_STAT3
+      sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, 0, regSample);
+#else
+      for(i=0; i<nCol; i++){
+        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);
+      }
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);
+#endif
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid);
+      sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */
+      sqlite3VdbeJumpHere(v, addrIsNull);
+    }
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+    /* End of analysis */
+    sqlite3VdbeJumpHere(v, addrRewind);
   }
 
-  /* If the table has no indices, create a single sqlite_stat1 entry
-  ** containing NULL as the index name and the row count as the content.
+
+  /* Create a single sqlite_stat1 entry containing NULL as the index
+  ** name and the row count as the content.
   */
-  if( pTab->pIndex==0 ){
-    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
+  if( pOnlyIdx==0 && needTableCnt ){
     VdbeComment((v, "%s", pTab->zName));
-    sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat1);
-    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
-    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1);
-  }else{
+    sqlite3VdbeAddOp2(v, OP_Count, iTabCur, regStat1);
+    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
+    assert( "BBB"[0]==SQLITE_AFF_TEXT );
+    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);
+    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
     sqlite3VdbeJumpHere(v, jZeroRows);
-    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);
   }
-  sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
-  sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
-  sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
-  sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
-  sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-  if( pParse->nMem<regRec ) pParse->nMem = regRec;
-  sqlite3VdbeJumpHere(v, jZeroRows);
 }
 
 
@@ -78229,16 +95937,18 @@ static void analyzeDatabase(Parse *pParse, int iDb){
   HashElem *k;
   int iStatCur;
   int iMem;
+  int iTab;
 
   sqlite3BeginWriteOperation(pParse, 0, iDb);
   iStatCur = pParse->nTab;
   pParse->nTab += 3;
   openStatTable(pParse, iDb, iStatCur, 0, 0);
   iMem = pParse->nMem+1;
+  iTab = pParse->nTab;
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
     Table *pTab = (Table*)sqliteHashData(k);
-    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem);
+    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
   }
   loadAnalysis(pParse, iDb);
 }
@@ -78263,7 +95973,7 @@ static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){
   }else{
     openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");
   }
-  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur, pParse->nMem+1);
+  analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur,pParse->nMem+1,pParse->nTab);
   loadAnalysis(pParse, iDb);
 }
 
@@ -78287,6 +95997,7 @@ SQLITE_PRIVATE void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
   Table *pTab;
   Index *pIdx;
   Token *pTableName;
+  Vdbe *v;
 
   /* Read the database schema. If an error occurs, leave an error message
   ** and code in pParse and return NULL. */
@@ -78334,6 +96045,8 @@ SQLITE_PRIVATE void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
       }
     }   
   }
+  v = sqlite3GetVdbe(pParse);
+  if( v ) sqlite3VdbeAddOp0(v, OP_Expire);
 }
 
 /*
@@ -78347,6 +96060,71 @@ struct analysisInfo {
 };
 
 /*
+** The first argument points to a nul-terminated string containing a
+** list of space separated integers. Read the first nOut of these into
+** the array aOut[].
+*/
+static void decodeIntArray(
+  char *zIntArray,       /* String containing int array to decode */
+  int nOut,              /* Number of slots in aOut[] */
+  tRowcnt *aOut,         /* Store integers here */
+  LogEst *aLog,          /* Or, if aOut==0, here */
+  Index *pIndex          /* Handle extra flags for this index, if not NULL */
+){
+  char *z = zIntArray;
+  int c;
+  int i;
+  tRowcnt v;
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( z==0 ) z = "";
+#else
+  assert( z!=0 );
+#endif
+  for(i=0; *z && i<nOut; i++){
+    v = 0;
+    while( (c=z[0])>='0' && c<='9' ){
+      v = v*10 + c - '0';
+      z++;
+    }
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    if( aOut ) aOut[i] = v;
+    if( aLog ) aLog[i] = sqlite3LogEst(v);
+#else
+    assert( aOut==0 );
+    UNUSED_PARAMETER(aOut);
+    assert( aLog!=0 );
+    aLog[i] = sqlite3LogEst(v);
+#endif
+    if( *z==' ' ) z++;
+  }
+#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
+  assert( pIndex!=0 ); {
+#else
+  if( pIndex ){
+#endif
+    pIndex->bUnordered = 0;
+    pIndex->noSkipScan = 0;
+    while( z[0] ){
+      if( sqlite3_strglob("unordered*", z)==0 ){
+        pIndex->bUnordered = 1;
+      }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
+        pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));
+      }else if( sqlite3_strglob("noskipscan*", z)==0 ){
+        pIndex->noSkipScan = 1;
+      }
+#ifdef SQLITE_ENABLE_COSTMULT
+      else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
+        pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
+      }
+#endif
+      while( z[0]!=0 && z[0]!=' ' ) z++;
+      while( z[0]==' ' ) z++;
+    }
+  }
+}
+
+/*
 ** This callback is invoked once for each index when reading the
 ** sqlite_stat1 table.  
 **
@@ -78361,8 +96139,6 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
   analysisInfo *pInfo = (analysisInfo*)pData;
   Index *pIndex;
   Table *pTable;
-  int i, c, n;
-  tRowcnt v;
   const char *z;
 
   assert( argc==3 );
@@ -78375,28 +96151,41 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
   if( pTable==0 ){
     return 0;
   }
-  if( argv[1] ){
-    pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
-  }else{
+  if( argv[1]==0 ){
     pIndex = 0;
+  }else if( sqlite3_stricmp(argv[0],argv[1])==0 ){
+    pIndex = sqlite3PrimaryKeyIndex(pTable);
+  }else{
+    pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
   }
-  n = pIndex ? pIndex->nColumn : 0;
   z = argv[2];
-  for(i=0; *z && i<=n; i++){
-    v = 0;
-    while( (c=z[0])>='0' && c<='9' ){
-      v = v*10 + c - '0';
-      z++;
-    }
-    if( i==0 ) pTable->nRowEst = v;
-    if( pIndex==0 ) break;
-    pIndex->aiRowEst[i] = v;
-    if( *z==' ' ) z++;
-    if( memcmp(z, "unordered", 10)==0 ){
-      pIndex->bUnordered = 1;
-      break;
-    }
+
+  if( pIndex ){
+    tRowcnt *aiRowEst = 0;
+    int nCol = pIndex->nKeyCol+1;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    /* Index.aiRowEst may already be set here if there are duplicate 
+    ** sqlite_stat1 entries for this index. In that case just clobber
+    ** the old data with the new instead of allocating a new array.  */
+    if( pIndex->aiRowEst==0 ){
+      pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol);
+      if( pIndex->aiRowEst==0 ) sqlite3OomFault(pInfo->db);
+    }
+    aiRowEst = pIndex->aiRowEst;
+#endif
+    pIndex->bUnordered = 0;
+    decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex);
+    if( pIndex->pPartIdxWhere==0 ) pTable->nRowLogEst = pIndex->aiRowLogEst[0];
+  }else{
+    Index fakeIdx;
+    fakeIdx.szIdxRow = pTable->szTabRow;
+#ifdef SQLITE_ENABLE_COSTMULT
+    fakeIdx.pTable = pTable;
+#endif
+    decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx);
+    pTable->szTabRow = fakeIdx.szIdxRow;
   }
+
   return 0;
 }
 
@@ -78405,14 +96194,12 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
 ** and its contents.
 */
 SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   if( pIdx->aSample ){
     int j;
     for(j=0; j<pIdx->nSample; j++){
       IndexSample *p = &pIdx->aSample[j];
-      if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){
-        sqlite3DbFree(db, p->u.z);
-      }
+      sqlite3DbFree(db, p->p);
     }
     sqlite3DbFree(db, pIdx->aSample);
   }
@@ -78423,150 +96210,260 @@ SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
 #else
   UNUSED_PARAMETER(db);
   UNUSED_PARAMETER(pIdx);
-#endif
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+}
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Populate the pIdx->aAvgEq[] array based on the samples currently
+** stored in pIdx->aSample[]. 
+*/
+static void initAvgEq(Index *pIdx){
+  if( pIdx ){
+    IndexSample *aSample = pIdx->aSample;
+    IndexSample *pFinal = &aSample[pIdx->nSample-1];
+    int iCol;
+    int nCol = 1;
+    if( pIdx->nSampleCol>1 ){
+      /* If this is stat4 data, then calculate aAvgEq[] values for all
+      ** sample columns except the last. The last is always set to 1, as
+      ** once the trailing PK fields are considered all index keys are
+      ** unique.  */
+      nCol = pIdx->nSampleCol-1;
+      pIdx->aAvgEq[nCol] = 1;
+    }
+    for(iCol=0; iCol<nCol; iCol++){
+      int nSample = pIdx->nSample;
+      int i;                    /* Used to iterate through samples */
+      tRowcnt sumEq = 0;        /* Sum of the nEq values */
+      tRowcnt avgEq = 0;
+      tRowcnt nRow;             /* Number of rows in index */
+      i64 nSum100 = 0;          /* Number of terms contributing to sumEq */
+      i64 nDist100;             /* Number of distinct values in index */
+
+      if( !pIdx->aiRowEst || iCol>=pIdx->nKeyCol || pIdx->aiRowEst[iCol+1]==0 ){
+        nRow = pFinal->anLt[iCol];
+        nDist100 = (i64)100 * pFinal->anDLt[iCol];
+        nSample--;
+      }else{
+        nRow = pIdx->aiRowEst[0];
+        nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];
+      }
+      pIdx->nRowEst0 = nRow;
+
+      /* Set nSum to the number of distinct (iCol+1) field prefixes that
+      ** occur in the stat4 table for this index. Set sumEq to the sum of 
+      ** the nEq values for column iCol for the same set (adding the value 
+      ** only once where there exist duplicate prefixes).  */
+      for(i=0; i<nSample; i++){
+        if( i==(pIdx->nSample-1)
+         || aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] 
+        ){
+          sumEq += aSample[i].anEq[iCol];
+          nSum100 += 100;
+        }
+      }
+
+      if( nDist100>nSum100 ){
+        avgEq = ((i64)100 * (nRow - sumEq))/(nDist100 - nSum100);
+      }
+      if( avgEq==0 ) avgEq = 1;
+      pIdx->aAvgEq[iCol] = avgEq;
+    }
+  }
+}
+
+/*
+** Look up an index by name.  Or, if the name of a WITHOUT ROWID table
+** is supplied instead, find the PRIMARY KEY index for that table.
+*/
+static Index *findIndexOrPrimaryKey(
+  sqlite3 *db,
+  const char *zName,
+  const char *zDb
+){
+  Index *pIdx = sqlite3FindIndex(db, zName, zDb);
+  if( pIdx==0 ){
+    Table *pTab = sqlite3FindTable(db, zName, zDb);
+    if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab);
+  }
+  return pIdx;
 }
 
-#ifdef SQLITE_ENABLE_STAT3
 /*
-** Load content from the sqlite_stat3 table into the Index.aSample[]
-** arrays of all indices.
+** Load the content from either the sqlite_stat4 or sqlite_stat3 table 
+** into the relevant Index.aSample[] arrays.
+**
+** Arguments zSql1 and zSql2 must point to SQL statements that return
+** data equivalent to the following (statements are different for stat3,
+** see the caller of this function for details):
+**
+**    zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx
+**    zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4
+**
+** where %Q is replaced with the database name before the SQL is executed.
 */
-static int loadStat3(sqlite3 *db, const char *zDb){
+static int loadStatTbl(
+  sqlite3 *db,                  /* Database handle */
+  int bStat3,                   /* Assume single column records only */
+  const char *zSql1,            /* SQL statement 1 (see above) */
+  const char *zSql2,            /* SQL statement 2 (see above) */
+  const char *zDb               /* Database name (e.g. "main") */
+){
   int rc;                       /* Result codes from subroutines */
   sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */
   char *zSql;                   /* Text of the SQL statement */
   Index *pPrevIdx = 0;          /* Previous index in the loop */
-  int idx = 0;                  /* slot in pIdx->aSample[] for next sample */
-  int eType;                    /* Datatype of a sample */
   IndexSample *pSample;         /* A slot in pIdx->aSample[] */
 
-  if( !sqlite3FindTable(db, "sqlite_stat3", zDb) ){
-    return SQLITE_OK;
-  }
-
-  zSql = sqlite3MPrintf(db, 
-      "SELECT idx,count(*) FROM %Q.sqlite_stat3"
-      " GROUP BY idx", zDb);
+  assert( db->lookaside.bDisable );
+  zSql = sqlite3MPrintf(db, zSql1, zDb);
   if( !zSql ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
   sqlite3DbFree(db, zSql);
   if( rc ) return rc;
 
   while( sqlite3_step(pStmt)==SQLITE_ROW ){
+    int nIdxCol = 1;              /* Number of columns in stat4 records */
+
     char *zIndex;   /* Index name */
     Index *pIdx;    /* Pointer to the index object */
     int nSample;    /* Number of samples */
+    int nByte;      /* Bytes of space required */
+    int i;          /* Bytes of space required */
+    tRowcnt *pSpace;
 
     zIndex = (char *)sqlite3_column_text(pStmt, 0);
     if( zIndex==0 ) continue;
     nSample = sqlite3_column_int(pStmt, 1);
-    pIdx = sqlite3FindIndex(db, zIndex, zDb);
-    if( pIdx==0 ) continue;
-    assert( pIdx->nSample==0 );
-    pIdx->nSample = nSample;
-    pIdx->aSample = sqlite3MallocZero( nSample*sizeof(IndexSample) );
-    pIdx->avgEq = pIdx->aiRowEst[1];
+    pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
+    assert( pIdx==0 || bStat3 || pIdx->nSample==0 );
+    /* Index.nSample is non-zero at this point if data has already been
+    ** loaded from the stat4 table. In this case ignore stat3 data.  */
+    if( pIdx==0 || pIdx->nSample ) continue;
+    if( bStat3==0 ){
+      assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 );
+      if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
+        nIdxCol = pIdx->nKeyCol;
+      }else{
+        nIdxCol = pIdx->nColumn;
+      }
+    }
+    pIdx->nSampleCol = nIdxCol;
+    nByte = sizeof(IndexSample) * nSample;
+    nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;
+    nByte += nIdxCol * sizeof(tRowcnt);     /* Space for Index.aAvgEq[] */
+
+    pIdx->aSample = sqlite3DbMallocZero(db, nByte);
     if( pIdx->aSample==0 ){
-      db->mallocFailed = 1;
       sqlite3_finalize(pStmt);
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
+    }
+    pSpace = (tRowcnt*)&pIdx->aSample[nSample];
+    pIdx->aAvgEq = pSpace; pSpace += nIdxCol;
+    for(i=0; i<nSample; i++){
+      pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;
+      pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;
+      pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol;
     }
+    assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) );
   }
   rc = sqlite3_finalize(pStmt);
   if( rc ) return rc;
 
-  zSql = sqlite3MPrintf(db, 
-      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat3", zDb);
+  zSql = sqlite3MPrintf(db, zSql2, zDb);
   if( !zSql ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
   sqlite3DbFree(db, zSql);
   if( rc ) return rc;
 
   while( sqlite3_step(pStmt)==SQLITE_ROW ){
-    char *zIndex;   /* Index name */
-    Index *pIdx;    /* Pointer to the index object */
-    int i;          /* Loop counter */
-    tRowcnt sumEq;  /* Sum of the nEq values */
+    char *zIndex;                 /* Index name */
+    Index *pIdx;                  /* Pointer to the index object */
+    int nCol = 1;                 /* Number of columns in index */
 
     zIndex = (char *)sqlite3_column_text(pStmt, 0);
     if( zIndex==0 ) continue;
-    pIdx = sqlite3FindIndex(db, zIndex, zDb);
+    pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
     if( pIdx==0 ) continue;
-    if( pIdx==pPrevIdx ){
-      idx++;
-    }else{
+    /* This next condition is true if data has already been loaded from 
+    ** the sqlite_stat4 table. In this case ignore stat3 data.  */
+    nCol = pIdx->nSampleCol;
+    if( bStat3 && nCol>1 ) continue;
+    if( pIdx!=pPrevIdx ){
+      initAvgEq(pPrevIdx);
       pPrevIdx = pIdx;
-      idx = 0;
-    }
-    assert( idx<pIdx->nSample );
-    pSample = &pIdx->aSample[idx];
-    pSample->nEq = (tRowcnt)sqlite3_column_int64(pStmt, 1);
-    pSample->nLt = (tRowcnt)sqlite3_column_int64(pStmt, 2);
-    pSample->nDLt = (tRowcnt)sqlite3_column_int64(pStmt, 3);
-    if( idx==pIdx->nSample-1 ){
-      if( pSample->nDLt>0 ){
-        for(i=0, sumEq=0; i<=idx-1; i++) sumEq += pIdx->aSample[i].nEq;
-        pIdx->avgEq = (pSample->nLt - sumEq)/pSample->nDLt;
-      }
-      if( pIdx->avgEq<=0 ) pIdx->avgEq = 1;
-    }
-    eType = sqlite3_column_type(pStmt, 4);
-    pSample->eType = (u8)eType;
-    switch( eType ){
-      case SQLITE_INTEGER: {
-        pSample->u.i = sqlite3_column_int64(pStmt, 4);
-        break;
-      }
-      case SQLITE_FLOAT: {
-        pSample->u.r = sqlite3_column_double(pStmt, 4);
-        break;
-      }
-      case SQLITE_NULL: {
-        break;
-      }
-      default: assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); {
-        const char *z = (const char *)(
-              (eType==SQLITE_BLOB) ?
-              sqlite3_column_blob(pStmt, 4):
-              sqlite3_column_text(pStmt, 4)
-           );
-        int n = z ? sqlite3_column_bytes(pStmt, 4) : 0;
-        pSample->nByte = n;
-        if( n < 1){
-          pSample->u.z = 0;
-        }else{
-          pSample->u.z = sqlite3Malloc(n);
-          if( pSample->u.z==0 ){
-            db->mallocFailed = 1;
-            sqlite3_finalize(pStmt);
-            return SQLITE_NOMEM;
-          }
-          memcpy(pSample->u.z, z, n);
-        }
-      }
     }
+    pSample = &pIdx->aSample[pIdx->nSample];
+    decodeIntArray((char*)sqlite3_column_text(pStmt,1),nCol,pSample->anEq,0,0);
+    decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0);
+    decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0);
+
+    /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer.
+    ** This is in case the sample record is corrupted. In that case, the
+    ** sqlite3VdbeRecordCompare() may read up to two varints past the
+    ** end of the allocated buffer before it realizes it is dealing with
+    ** a corrupt record. Adding the two 0x00 bytes prevents this from causing
+    ** a buffer overread.  */
+    pSample->n = sqlite3_column_bytes(pStmt, 4);
+    pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);
+    if( pSample->p==0 ){
+      sqlite3_finalize(pStmt);
+      return SQLITE_NOMEM_BKPT;
+    }
+    memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);
+    pIdx->nSample++;
   }
-  return sqlite3_finalize(pStmt);
+  rc = sqlite3_finalize(pStmt);
+  if( rc==SQLITE_OK ) initAvgEq(pPrevIdx);
+  return rc;
 }
-#endif /* SQLITE_ENABLE_STAT3 */
 
 /*
-** Load the content of the sqlite_stat1 and sqlite_stat3 tables. The
+** Load content from the sqlite_stat4 and sqlite_stat3 tables into 
+** the Index.aSample[] arrays of all indices.
+*/
+static int loadStat4(sqlite3 *db, const char *zDb){
+  int rc = SQLITE_OK;             /* Result codes from subroutines */
+
+  assert( db->lookaside.bDisable );
+  if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
+    rc = loadStatTbl(db, 0,
+      "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 
+      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
+      zDb
+    );
+  }
+
+  if( rc==SQLITE_OK && sqlite3FindTable(db, "sqlite_stat3", zDb) ){
+    rc = loadStatTbl(db, 1,
+      "SELECT idx,count(*) FROM %Q.sqlite_stat3 GROUP BY idx", 
+      "SELECT idx,neq,nlt,ndlt,sqlite_record(sample) FROM %Q.sqlite_stat3",
+      zDb
+    );
+  }
+
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** Load the content of the sqlite_stat1 and sqlite_stat3/4 tables. The
 ** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]
-** arrays. The contents of sqlite_stat3 are used to populate the
+** arrays. The contents of sqlite_stat3/4 are used to populate the
 ** Index.aSample[] arrays.
 **
 ** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR
-** is returned. In this case, even if SQLITE_ENABLE_STAT3 was defined 
-** during compilation and the sqlite_stat3 table is present, no data is 
+** is returned. In this case, even if SQLITE_ENABLE_STAT3/4 was defined 
+** during compilation and the sqlite_stat3/4 table is present, no data is 
 ** read from it.
 **
-** If SQLITE_ENABLE_STAT3 was defined during compilation and the 
-** sqlite_stat3 table is not present in the database, SQLITE_ERROR is
+** If SQLITE_ENABLE_STAT3/4 was defined during compilation and the 
+** sqlite_stat4 table is not present in the database, SQLITE_ERROR is
 ** returned. However, in this case, data is read from the sqlite_stat1
 ** table (if it is present) before returning.
 **
@@ -78578,7 +96475,7 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
   analysisInfo sInfo;
   HashElem *i;
   char *zSql;
-  int rc;
+  int rc = SQLITE_OK;
 
   assert( iDb>=0 && iDb<db->nDb );
   assert( db->aDb[iDb].pBt!=0 );
@@ -78587,40 +96484,50 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
     Index *pIdx = sqliteHashData(i);
-    sqlite3DefaultRowEst(pIdx);
-#ifdef SQLITE_ENABLE_STAT3
+    pIdx->aiRowLogEst[0] = 0;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
     sqlite3DeleteIndexSamples(db, pIdx);
     pIdx->aSample = 0;
 #endif
   }
 
-  /* Check to make sure the sqlite_stat1 table exists */
+  /* Load new statistics out of the sqlite_stat1 table */
   sInfo.db = db;
   sInfo.zDatabase = db->aDb[iDb].zName;
-  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){
-    return SQLITE_ERROR;
+  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){
+    zSql = sqlite3MPrintf(db, 
+        "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+    }else{
+      rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
+      sqlite3DbFree(db, zSql);
+    }
   }
 
-  /* Load new statistics out of the sqlite_stat1 table */
-  zSql = sqlite3MPrintf(db, 
-      "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
-  if( zSql==0 ){
-    rc = SQLITE_NOMEM;
-  }else{
-    rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
-    sqlite3DbFree(db, zSql);
+  /* Set appropriate defaults on all indexes not in the sqlite_stat1 table */
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
+    Index *pIdx = sqliteHashData(i);
+    if( pIdx->aiRowLogEst[0]==0 ) sqlite3DefaultRowEst(pIdx);
   }
 
-
-  /* Load the statistics from the sqlite_stat3 table. */
-#ifdef SQLITE_ENABLE_STAT3
-  if( rc==SQLITE_OK ){
-    rc = loadStat3(db, sInfo.zDatabase);
+  /* Load the statistics from the sqlite_stat4 table. */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  if( rc==SQLITE_OK && OptimizationEnabled(db, SQLITE_Stat34) ){
+    db->lookaside.bDisable++;
+    rc = loadStat4(db, sInfo.zDatabase);
+    db->lookaside.bDisable--;
+  }
+  for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){
+    Index *pIdx = sqliteHashData(i);
+    sqlite3_free(pIdx->aiRowEst);
+    pIdx->aiRowEst = 0;
   }
 #endif
 
   if( rc==SQLITE_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return rc;
 }
@@ -78643,6 +96550,7 @@ SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
 *************************************************************************
 ** This file contains code used to implement the ATTACH and DETACH commands.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_ATTACH
 /*
@@ -78669,10 +96577,6 @@ static int resolveAttachExpr(NameContext *pName, Expr *pExpr)
   if( pExpr ){
     if( pExpr->op!=TK_ID ){
       rc = sqlite3ResolveExprNames(pName, pExpr);
-      if( rc==SQLITE_OK && !sqlite3ExprIsConstant(pExpr) ){
-        sqlite3ErrorMsg(pName->pParse, "invalid name: \"%s\"", pExpr->u.zToken);
-        return SQLITE_ERROR;
-      }
     }else{
       pExpr->op = TK_STRING;
     }
@@ -78740,11 +96644,11 @@ static void attachFunc(
     }
   }
 
-  /* Allocate the new entry in the db->aDb[] array and initialise the schema
+  /* Allocate the new entry in the db->aDb[] array and initialize the schema
   ** hash tables.
   */
   if( db->aDb==db->aDbStatic ){
-    aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
+    aNew = sqlite3DbMallocRawNN(db, sizeof(db->aDb[0])*3 );
     if( aNew==0 ) return;
     memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
   }else{
@@ -78757,12 +96661,12 @@ static void attachFunc(
 
   /* Open the database file. If the btree is successfully opened, use
   ** it to obtain the database schema. At this point the schema may
-  ** or may not be initialised.
+  ** or may not be initialized.
   */
   flags = db->openFlags;
   rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
   if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
     sqlite3_result_error(context, zErr, -1);
     sqlite3_free(zErr);
     return;
@@ -78779,21 +96683,27 @@ static void attachFunc(
     Pager *pPager;
     aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt);
     if( !aNew->pSchema ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
       zErrDyn = sqlite3MPrintf(db, 
         "attached databases must use the same text encoding as main database");
       rc = SQLITE_ERROR;
     }
+    sqlite3BtreeEnter(aNew->pBt);
     pPager = sqlite3BtreePager(aNew->pBt);
     sqlite3PagerLockingMode(pPager, db->dfltLockMode);
     sqlite3BtreeSecureDelete(aNew->pBt,
                              sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+    sqlite3BtreeSetPagerFlags(aNew->pBt,
+                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
+#endif
+    sqlite3BtreeLeave(aNew->pBt);
   }
-  aNew->safety_level = 3;
+  aNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
   aNew->zName = sqlite3DbStrDup(db, zName);
   if( rc==SQLITE_OK && aNew->zName==0 ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
 
 
@@ -78821,7 +96731,7 @@ static void attachFunc(
       case SQLITE_NULL:
         /* No key specified.  Use the key from the main database */
         sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
-        if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){
+        if( nKey>0 || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
           rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
         }
         break;
@@ -78839,6 +96749,15 @@ static void attachFunc(
     rc = sqlite3Init(db, &zErrDyn);
     sqlite3BtreeLeaveAll(db);
   }
+#ifdef SQLITE_USER_AUTHENTICATION
+  if( rc==SQLITE_OK ){
+    u8 newAuth = 0;
+    rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);
+    if( newAuth<db->auth.authLevel ){
+      rc = SQLITE_AUTH_USER;
+    }
+  }
+#endif
   if( rc ){
     int iDb = db->nDb - 1;
     assert( iDb>=2 );
@@ -78847,10 +96766,10 @@ static void attachFunc(
       db->aDb[iDb].pBt = 0;
       db->aDb[iDb].pSchema = 0;
     }
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
     db->nDb = iDb;
     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       sqlite3DbFree(db, zErrDyn);
       zErrDyn = sqlite3MPrintf(db, "out of memory");
     }else if( zErrDyn==0 ){
@@ -78919,7 +96838,7 @@ static void detachFunc(
   sqlite3BtreeClose(pDb->pBt);
   pDb->pBt = 0;
   pDb->pSchema = 0;
-  sqlite3ResetInternalSchema(db, -1);
+  sqlite3CollapseDatabaseArray(db);
   return;
 
 detach_error:
@@ -78953,7 +96872,6 @@ static void codeAttach(
       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
   ){
-    pParse->nErr++;
     goto attach_end;
   }
 
@@ -78981,11 +96899,11 @@ static void codeAttach(
 
   assert( v || db->mallocFailed );
   if( v ){
-    sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3);
+    sqlite3VdbeAddOp4(v, OP_Function0, 0, regArgs+3-pFunc->nArg, regArgs+3,
+                      (char *)pFunc, P4_FUNCDEF);
     assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
     sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
-    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);
-
+ 
     /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
     ** statement only). For DETACH, set it to false (expire all existing
     ** statements).
@@ -79007,16 +96925,13 @@ attach_end:
 SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){
   static const FuncDef detach_func = {
     1,                /* nArg */
-    SQLITE_UTF8,      /* iPrefEnc */
-    0,                /* flags */
+    SQLITE_UTF8,      /* funcFlags */
     0,                /* pUserData */
     0,                /* pNext */
-    detachFunc,       /* xFunc */
-    0,                /* xStep */
+    detachFunc,       /* xSFunc */
     0,                /* xFinalize */
     "sqlite_detach",  /* zName */
-    0,                /* pHash */
-    0                 /* pDestructor */
+    {0}
   };
   codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
 }
@@ -79029,16 +96944,13 @@ SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){
 SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
   static const FuncDef attach_func = {
     3,                /* nArg */
-    SQLITE_UTF8,      /* iPrefEnc */
-    0,                /* flags */
+    SQLITE_UTF8,      /* funcFlags */
     0,                /* pUserData */
     0,                /* pNext */
-    attachFunc,       /* xFunc */
-    0,                /* xStep */
+    attachFunc,       /* xSFunc */
     0,                /* xFinalize */
     "sqlite_attach",  /* zName */
-    0,                /* pHash */
-    0                 /* pDestructor */
+    {0}
   };
   codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
 }
@@ -79047,11 +96959,8 @@ SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *p
 /*
 ** Initialize a DbFixer structure.  This routine must be called prior
 ** to passing the structure to one of the sqliteFixAAAA() routines below.
-**
-** The return value indicates whether or not fixation is required.  TRUE
-** means we do need to fix the database references, FALSE means we do not.
 */
-SQLITE_PRIVATE int sqlite3FixInit(
+SQLITE_PRIVATE void sqlite3FixInit(
   DbFixer *pFix,      /* The fixer to be initialized */
   Parse *pParse,      /* Error messages will be written here */
   int iDb,            /* This is the database that must be used */
@@ -79060,14 +96969,14 @@ SQLITE_PRIVATE int sqlite3FixInit(
 ){
   sqlite3 *db;
 
-  if( NEVER(iDb<0) || iDb==1 ) return 0;
   db = pParse->db;
   assert( db->nDb>iDb );
   pFix->pParse = pParse;
   pFix->zDb = db->aDb[iDb].zName;
+  pFix->pSchema = db->aDb[iDb].pSchema;
   pFix->zType = zType;
   pFix->pName = pName;
-  return 1;
+  pFix->bVarOnly = (iDb==1);
 }
 
 /*
@@ -79095,13 +97004,16 @@ SQLITE_PRIVATE int sqlite3FixSrcList(
   if( NEVER(pList==0) ) return 0;
   zDb = pFix->zDb;
   for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
-    if( pItem->zDatabase==0 ){
-      pItem->zDatabase = sqlite3DbStrDup(pFix->pParse->db, zDb);
-    }else if( sqlite3StrICmp(pItem->zDatabase,zDb)!=0 ){
-      sqlite3ErrorMsg(pFix->pParse,
-         "%s %T cannot reference objects in database %s",
-         pFix->zType, pFix->pName, pItem->zDatabase);
-      return 1;
+    if( pFix->bVarOnly==0 ){
+      if( pItem->zDatabase && sqlite3StrICmp(pItem->zDatabase, zDb) ){
+        sqlite3ErrorMsg(pFix->pParse,
+            "%s %T cannot reference objects in database %s",
+            pFix->zType, pFix->pName, pItem->zDatabase);
+        return 1;
+      }
+      sqlite3DbFree(pFix->pParse->db, pItem->zDatabase);
+      pItem->zDatabase = 0;
+      pItem->pSchema = pFix->pSchema;
     }
 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
     if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
@@ -79125,9 +97037,21 @@ SQLITE_PRIVATE int sqlite3FixSelect(
     if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
       return 1;
     }
+    if( sqlite3FixExprList(pFix, pSelect->pGroupBy) ){
+      return 1;
+    }
     if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
       return 1;
     }
+    if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
+      return 1;
+    }
+    if( sqlite3FixExpr(pFix, pSelect->pOffset) ){
+      return 1;
+    }
     pSelect = pSelect->pPrior;
   }
   return 0;
@@ -79137,7 +97061,15 @@ SQLITE_PRIVATE int sqlite3FixExpr(
   Expr *pExpr        /* The expression to be fixed to one database */
 ){
   while( pExpr ){
-    if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ) break;
+    if( pExpr->op==TK_VARIABLE ){
+      if( pFix->pParse->db->init.busy ){
+        pExpr->op = TK_NULL;
+      }else{
+        sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType);
+        return 1;
+      }
+    }
+    if( ExprHasProperty(pExpr, EP_TokenOnly) ) break;
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
       if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;
     }else{
@@ -79205,6 +97137,7 @@ SQLITE_PRIVATE int sqlite3FixTriggerStep(
 ** systems that do not need this facility may omit it by recompiling
 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** All of the code in this file may be omitted by defining a single
@@ -79257,13 +97190,16 @@ SQLITE_PRIVATE int sqlite3FixTriggerStep(
 ** Setting the auth function to NULL disables this hook.  The default
 ** setting of the auth function is NULL.
 */
-SQLITE_API int sqlite3_set_authorizer(
+SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
   sqlite3 *db,
   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
   void *pArg
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
-  db->xAuth = xAuth;
+  db->xAuth = (sqlite3_xauth)xAuth;
   db->pAuthArg = pArg;
   sqlite3ExpirePreparedStatements(db);
   sqlite3_mutex_leave(db->mutex);
@@ -79298,7 +97234,12 @@ SQLITE_PRIVATE int sqlite3AuthReadCol(
   char *zDb = db->aDb[iDb].zName; /* Name of attached database */
   int rc;                         /* Auth callback return code */
 
-  rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext);
+  if( db->init.busy ) return SQLITE_OK;
+  rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext
+#ifdef SQLITE_USER_AUTHENTICATION
+                 ,db->auth.zAuthUser
+#endif
+                );
   if( rc==SQLITE_DENY ){
     if( db->nDb>2 || iDb!=0 ){
       sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol);
@@ -79398,7 +97339,11 @@ SQLITE_PRIVATE int sqlite3AuthCheck(
   if( db->xAuth==0 ){
     return SQLITE_OK;
   }
-  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
+  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext
+#ifdef SQLITE_USER_AUTHENTICATION
+                 ,db->auth.zAuthUser
+#endif
+                );
   if( rc==SQLITE_DENY ){
     sqlite3ErrorMsg(pParse, "not authorized");
     pParse->rc = SQLITE_AUTH;
@@ -79464,15 +97409,7 @@ SQLITE_PRIVATE void sqlite3AuthContextPop(AuthContext *pContext){
 **     COMMIT
 **     ROLLBACK
 */
-
-/*
-** This routine is called when a new SQL statement is beginning to
-** be parsed.  Initialize the pParse structure as needed.
-*/
-SQLITE_PRIVATE void sqlite3BeginParse(Parse *pParse, int explainFlag){
-  pParse->explain = (u8)explainFlag;
-  pParse->nVar = 0;
-}
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
 /*
@@ -79528,7 +97465,7 @@ SQLITE_PRIVATE void sqlite3TableLock(
     p->zName = zName;
   }else{
     pToplevel->nTableLock = 0;
-    pToplevel->db->mallocFailed = 1;
+    sqlite3OomFault(pToplevel->db);
   }
 }
 
@@ -79555,6 +97492,19 @@ static void codeTableLocks(Parse *pParse){
 #endif
 
 /*
+** Return TRUE if the given yDbMask object is empty - if it contains no
+** 1 bits.  This routine is used by the DbMaskAllZero() and DbMaskNotZero()
+** macros when SQLITE_MAX_ATTACHED is greater than 30.
+*/
+#if SQLITE_MAX_ATTACHED>30
+SQLITE_PRIVATE int sqlite3DbMaskAllZero(yDbMask m){
+  int i;
+  for(i=0; i<sizeof(yDbMask); i++) if( m[i] ) return 0;
+  return 1;
+}
+#endif
+
+/*
 ** This routine is called after a single SQL statement has been
 ** parsed and a VDBE program to execute that statement has been
 ** prepared.  This routine puts the finishing touches on the
@@ -79568,10 +97518,13 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
   sqlite3 *db;
   Vdbe *v;
 
+  assert( pParse->pToplevel==0 );
   db = pParse->db;
-  if( db->mallocFailed ) return;
   if( pParse->nested ) return;
-  if( pParse->nErr ) return;
+  if( db->mallocFailed || pParse->nErr ){
+    if( pParse->rc==SQLITE_OK ) pParse->rc = SQLITE_ERROR;
+    return;
+  }
 
   /* Begin by generating some termination code at the end of the
   ** vdbe program
@@ -79580,38 +97533,52 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
   assert( !pParse->isMultiWrite 
        || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
   if( v ){
+    while( sqlite3VdbeDeletePriorOpcode(v, OP_Close) ){}
     sqlite3VdbeAddOp0(v, OP_Halt);
 
+#if SQLITE_USER_AUTHENTICATION
+    if( pParse->nTableLock>0 && db->init.busy==0 ){
+      sqlite3UserAuthInit(db);
+      if( db->auth.authLevel<UAUTH_User ){
+        pParse->rc = SQLITE_AUTH_USER;
+        sqlite3ErrorMsg(pParse, "user not authenticated");
+        return;
+      }
+    }
+#endif
+
     /* The cookie mask contains one bit for each database file open.
     ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
     ** set for each database that is used.  Generate code to start a
     ** transaction on each used database and to verify the schema cookie
     ** on each used database.
     */
-    if( pParse->cookieGoto>0 ){
-      yDbMask mask;
-      int iDb;
-      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
-      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
-        if( (mask & pParse->cookieMask)==0 ) continue;
+    if( db->mallocFailed==0 
+     && (DbMaskNonZero(pParse->cookieMask) || pParse->pConstExpr)
+    ){
+      int iDb, i;
+      assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );
+      sqlite3VdbeJumpHere(v, 0);
+      for(iDb=0; iDb<db->nDb; iDb++){
+        if( DbMaskTest(pParse->cookieMask, iDb)==0 ) continue;
         sqlite3VdbeUsesBtree(v, iDb);
-        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
-        if( db->init.busy==0 ){
-          assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-          sqlite3VdbeAddOp3(v, OP_VerifyCookie,
-                            iDb, pParse->cookieValue[iDb],
-                            db->aDb[iDb].pSchema->iGeneration);
-        }
+        sqlite3VdbeAddOp4Int(v,
+          OP_Transaction,                    /* Opcode */
+          iDb,                               /* P1 */
+          DbMaskTest(pParse->writeMask,iDb), /* P2 */
+          pParse->cookieValue[iDb],          /* P3 */
+          db->aDb[iDb].pSchema->iGeneration  /* P4 */
+        );
+        if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
+        VdbeComment((v,
+              "usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));
       }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-      {
-        int i;
-        for(i=0; i<pParse->nVtabLock; i++){
-          char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
-          sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
-        }
-        pParse->nVtabLock = 0;
+      for(i=0; i<pParse->nVtabLock; i++){
+        char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
+        sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
       }
+      pParse->nVtabLock = 0;
 #endif
 
       /* Once all the cookies have been verified and transactions opened, 
@@ -79624,35 +97591,43 @@ SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
       */
       sqlite3AutoincrementBegin(pParse);
 
+      /* Code constant expressions that where factored out of inner loops */
+      if( pParse->pConstExpr ){
+        ExprList *pEL = pParse->pConstExpr;
+        pParse->okConstFactor = 0;
+        for(i=0; i<pEL->nExpr; i++){
+          sqlite3ExprCode(pParse, pEL->a[i].pExpr, pEL->a[i].u.iConstExprReg);
+        }
+      }
+
       /* Finally, jump back to the beginning of the executable code. */
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->cookieGoto);
+      sqlite3VdbeGoto(v, 1);
     }
   }
 
 
   /* Get the VDBE program ready for execution
   */
-  if( v && ALWAYS(pParse->nErr==0) && !db->mallocFailed ){
-#ifdef SQLITE_DEBUG
-    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
-    sqlite3VdbeTrace(v, trace);
-#endif
+  if( v && pParse->nErr==0 && !db->mallocFailed ){
     assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
     /* A minimum of one cursor is required if autoincrement is used
     *  See ticket [a696379c1f08866] */
     if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
     sqlite3VdbeMakeReady(v, pParse);
     pParse->rc = SQLITE_DONE;
-    pParse->colNamesSet = 0;
   }else{
     pParse->rc = SQLITE_ERROR;
   }
+
+  /* We are done with this Parse object. There is no need to de-initialize it */
+#if 0
+  pParse->colNamesSet = 0;
   pParse->nTab = 0;
   pParse->nMem = 0;
   pParse->nSet = 0;
   pParse->nVar = 0;
-  pParse->cookieMask = 0;
-  pParse->cookieGoto = 0;
+  DbMaskZero(pParse->cookieMask);
+#endif
 }
 
 /*
@@ -79693,6 +97668,16 @@ SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
   pParse->nested--;
 }
 
+#if SQLITE_USER_AUTHENTICATION
+/*
+** Return TRUE if zTable is the name of the system table that stores the
+** list of users and their access credentials.
+*/
+SQLITE_PRIVATE int sqlite3UserAuthTable(const char *zTable){
+  return sqlite3_stricmp(zTable, "sqlite_user")==0;
+}
+#endif
+
 /*
 ** Locate the in-memory structure that describes a particular database
 ** table given the name of that table and (optionally) the name of the
@@ -79708,16 +97693,21 @@ SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
 SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
   Table *p = 0;
   int i;
-  int nName;
-  assert( zName!=0 );
-  nName = sqlite3Strlen30(zName);
+
   /* All mutexes are required for schema access.  Make sure we hold them. */
   assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
+#if SQLITE_USER_AUTHENTICATION
+  /* Only the admin user is allowed to know that the sqlite_user table
+  ** exists */
+  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
+    return 0;
+  }
+#endif
   for(i=OMIT_TEMPDB; i<db->nDb; i++){
     int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
     if( zDatabase!=0 && sqlite3StrICmp(zDatabase, db->aDb[j].zName) ) continue;
     assert( sqlite3SchemaMutexHeld(db, j, 0) );
-    p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName, nName);
+    p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
     if( p ) break;
   }
   return p;
@@ -79735,7 +97725,7 @@ SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const cha
 */
 SQLITE_PRIVATE Table *sqlite3LocateTable(
   Parse *pParse,         /* context in which to report errors */
-  int isView,            /* True if looking for a VIEW rather than a TABLE */
+  u32 flags,             /* LOCATE_VIEW or LOCATE_NOERR */
   const char *zName,     /* Name of the table we are looking for */
   const char *zDbase     /* Name of the database.  Might be NULL */
 ){
@@ -79749,18 +97739,57 @@ SQLITE_PRIVATE Table *sqlite3LocateTable(
 
   p = sqlite3FindTable(pParse->db, zName, zDbase);
   if( p==0 ){
-    const char *zMsg = isView ? "no such view" : "no such table";
-    if( zDbase ){
-      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
-    }else{
-      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
+    const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( sqlite3FindDbName(pParse->db, zDbase)<1 ){
+      /* If zName is the not the name of a table in the schema created using
+      ** CREATE, then check to see if it is the name of an virtual table that
+      ** can be an eponymous virtual table. */
+      Module *pMod = (Module*)sqlite3HashFind(&pParse->db->aModule, zName);
+      if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
+        return pMod->pEpoTab;
+      }
+    }
+#endif
+    if( (flags & LOCATE_NOERR)==0 ){
+      if( zDbase ){
+        sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
+      }else{
+        sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
+      }
+      pParse->checkSchema = 1;
     }
-    pParse->checkSchema = 1;
   }
+
   return p;
 }
 
 /*
+** Locate the table identified by *p.
+**
+** This is a wrapper around sqlite3LocateTable(). The difference between
+** sqlite3LocateTable() and this function is that this function restricts
+** the search to schema (p->pSchema) if it is not NULL. p->pSchema may be
+** non-NULL if it is part of a view or trigger program definition. See
+** sqlite3FixSrcList() for details.
+*/
+SQLITE_PRIVATE Table *sqlite3LocateTableItem(
+  Parse *pParse, 
+  u32 flags,
+  struct SrcList_item *p
+){
+  const char *zDb;
+  assert( p->pSchema==0 || p->zDatabase==0 );
+  if( p->pSchema ){
+    int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);
+    zDb = pParse->db->aDb[iDb].zName;
+  }else{
+    zDb = p->zDatabase;
+  }
+  return sqlite3LocateTable(pParse, flags, p->zName, zDb);
+}
+
+/*
 ** Locate the in-memory structure that describes 
 ** a particular index given the name of that index
 ** and the name of the database that contains the index.
@@ -79775,7 +97804,6 @@ SQLITE_PRIVATE Table *sqlite3LocateTable(
 SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){
   Index *p = 0;
   int i;
-  int nName = sqlite3Strlen30(zName);
   /* All mutexes are required for schema access.  Make sure we hold them. */
   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
   for(i=OMIT_TEMPDB; i<db->nDb; i++){
@@ -79784,7 +97812,7 @@ SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const cha
     assert( pSchema );
     if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zName) ) continue;
     assert( sqlite3SchemaMutexHeld(db, j, 0) );
-    p = sqlite3HashFind(&pSchema->idxHash, zName, nName);
+    p = sqlite3HashFind(&pSchema->idxHash, zName);
     if( p ) break;
   }
   return p;
@@ -79797,7 +97825,13 @@ static void freeIndex(sqlite3 *db, Index *p){
 #ifndef SQLITE_OMIT_ANALYZE
   sqlite3DeleteIndexSamples(db, p);
 #endif
+  sqlite3ExprDelete(db, p->pPartIdxWhere);
+  sqlite3ExprListDelete(db, p->aColExpr);
   sqlite3DbFree(db, p->zColAff);
+  if( p->isResized ) sqlite3DbFree(db, (void *)p->azColl);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  sqlite3_free(p->aiRowEst);
+#endif
   sqlite3DbFree(db, p);
 }
 
@@ -79809,13 +97843,11 @@ static void freeIndex(sqlite3 *db, Index *p){
 */
 SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
   Index *pIndex;
-  int len;
   Hash *pHash;
 
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   pHash = &db->aDb[iDb].pSchema->idxHash;
-  len = sqlite3Strlen30(zIdxName);
-  pIndex = sqlite3HashInsert(pHash, zIdxName, len, 0);
+  pIndex = sqlite3HashInsert(pHash, zIdxName, 0);
   if( ALWAYS(pIndex) ){
     if( pIndex->pTable->pIndex==pIndex ){
       pIndex->pTable->pIndex = pIndex->pNext;
@@ -79835,58 +97867,15 @@ SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char
 }
 
 /*
-** Erase all schema information from the in-memory hash tables of
-** a single database.  This routine is called to reclaim memory
-** before the database closes.  It is also called during a rollback
-** if there were schema changes during the transaction or if a
-** schema-cookie mismatch occurs.
+** Look through the list of open database files in db->aDb[] and if
+** any have been closed, remove them from the list.  Reallocate the
+** db->aDb[] structure to a smaller size, if possible.
 **
-** If iDb<0 then reset the internal schema tables for all database
-** files.  If iDb>=0 then reset the internal schema for only the
-** single file indicated.
+** Entry 0 (the "main" database) and entry 1 (the "temp" database)
+** are never candidates for being collapsed.
 */
-SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
+SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3 *db){
   int i, j;
-  assert( iDb<db->nDb );
-
-  if( iDb>=0 ){
-    /* Case 1:  Reset the single schema identified by iDb */
-    Db *pDb = &db->aDb[iDb];
-    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-    assert( pDb->pSchema!=0 );
-    sqlite3SchemaClear(pDb->pSchema);
-
-    /* If any database other than TEMP is reset, then also reset TEMP
-    ** since TEMP might be holding triggers that reference tables in the
-    ** other database.
-    */
-    if( iDb!=1 ){
-      pDb = &db->aDb[1];
-      assert( pDb->pSchema!=0 );
-      sqlite3SchemaClear(pDb->pSchema);
-    }
-    return;
-  }
-  /* Case 2 (from here to the end): Reset all schemas for all attached
-  ** databases. */
-  assert( iDb<0 );
-  sqlite3BtreeEnterAll(db);
-  for(i=0; i<db->nDb; i++){
-    Db *pDb = &db->aDb[i];
-    if( pDb->pSchema ){
-      sqlite3SchemaClear(pDb->pSchema);
-    }
-  }
-  db->flags &= ~SQLITE_InternChanges;
-  sqlite3VtabUnlockList(db);
-  sqlite3BtreeLeaveAll(db);
-
-  /* If one or more of the auxiliary database files has been closed,
-  ** then remove them from the auxiliary database list.  We take the
-  ** opportunity to do this here since we have just deleted all of the
-  ** schema hash tables and therefore do not have to make any changes
-  ** to any of those tables.
-  */
   for(i=j=2; i<db->nDb; i++){
     struct Db *pDb = &db->aDb[i];
     if( pDb->pBt==0 ){
@@ -79899,7 +97888,6 @@ SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
     }
     j++;
   }
-  memset(&db->aDb[j], 0, (db->nDb-j)*sizeof(db->aDb[j]));
   db->nDb = j;
   if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
     memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
@@ -79909,6 +97897,51 @@ SQLITE_PRIVATE void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
 }
 
 /*
+** Reset the schema for the database at index iDb.  Also reset the
+** TEMP schema.
+*/
+SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
+  Db *pDb;
+  assert( iDb<db->nDb );
+
+  /* Case 1:  Reset the single schema identified by iDb */
+  pDb = &db->aDb[iDb];
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  assert( pDb->pSchema!=0 );
+  sqlite3SchemaClear(pDb->pSchema);
+
+  /* If any database other than TEMP is reset, then also reset TEMP
+  ** since TEMP might be holding triggers that reference tables in the
+  ** other database.
+  */
+  if( iDb!=1 ){
+    pDb = &db->aDb[1];
+    assert( pDb->pSchema!=0 );
+    sqlite3SchemaClear(pDb->pSchema);
+  }
+  return;
+}
+
+/*
+** Erase all schema information from all attached databases (including
+** "main" and "temp") for a single database connection.
+*/
+SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){
+  int i;
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Db *pDb = &db->aDb[i];
+    if( pDb->pSchema ){
+      sqlite3SchemaClear(pDb->pSchema);
+    }
+  }
+  db->flags &= ~SQLITE_InternChanges;
+  sqlite3VtabUnlockList(db);
+  sqlite3BtreeLeaveAll(db);
+  sqlite3CollapseDatabaseArray(db);
+}
+
+/*
 ** This routine is called when a commit occurs.
 */
 SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3 *db){
@@ -79919,7 +97952,7 @@ SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3 *db){
 ** Delete memory allocated for the column names of a table or view (the
 ** Table.aCol[] array).
 */
-static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
+SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){
   int i;
   Column *pCol;
   assert( pTable!=0 );
@@ -79927,8 +97960,6 @@ static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
     for(i=0; i<pTable->nCol; i++, pCol++){
       sqlite3DbFree(db, pCol->zName);
       sqlite3ExprDelete(db, pCol->pDflt);
-      sqlite3DbFree(db, pCol->zDflt);
-      sqlite3DbFree(db, pCol->zType);
       sqlite3DbFree(db, pCol->zColl);
     }
     sqlite3DbFree(db, pTable->aCol);
@@ -79943,24 +97974,32 @@ static void sqliteDeleteColumnNames(sqlite3 *db, Table *pTable){
 ** the table data structure from the hash table.  But it does destroy
 ** memory structures of the indices and foreign keys associated with 
 ** the table.
+**
+** The db parameter is optional.  It is needed if the Table object 
+** contains lookaside memory.  (Table objects in the schema do not use
+** lookaside memory, but some ephemeral Table objects do.)  Or the
+** db parameter can be used with db->pnBytesFreed to measure the memory
+** used by the Table object.
 */
-SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
+static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){
   Index *pIndex, *pNext;
+  TESTONLY( int nLookaside; ) /* Used to verify lookaside not used for schema */
 
-  assert( !pTable || pTable->nRef>0 );
-
-  /* Do not delete the table until the reference count reaches zero. */
-  if( !pTable ) return;
-  if( ((!db || db->pnBytesFreed==0) && (--pTable->nRef)>0) ) return;
+  /* Record the number of outstanding lookaside allocations in schema Tables
+  ** prior to doing any free() operations.  Since schema Tables do not use
+  ** lookaside, this number should not change. */
+  TESTONLY( nLookaside = (db && (pTable->tabFlags & TF_Ephemeral)==0) ?
+                         db->lookaside.nOut : 0 );
 
   /* Delete all indices associated with this table. */
   for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
     pNext = pIndex->pNext;
-    assert( pIndex->pSchema==pTable->pSchema );
-    if( !db || db->pnBytesFreed==0 ){
+    assert( pIndex->pSchema==pTable->pSchema
+         || (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) );
+    if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){
       char *zName = pIndex->zName; 
       TESTONLY ( Index *pOld = ) sqlite3HashInsert(
-	  &pIndex->pSchema->idxHash, zName, sqlite3Strlen30(zName), 0
+         &pIndex->pSchema->idxHash, zName, 0
       );
       assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
       assert( pOld==pIndex || pOld==0 );
@@ -79973,19 +98012,27 @@ SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
 
   /* Delete the Table structure itself.
   */
-  sqliteDeleteColumnNames(db, pTable);
+  sqlite3DeleteColumnNames(db, pTable);
   sqlite3DbFree(db, pTable->zName);
   sqlite3DbFree(db, pTable->zColAff);
   sqlite3SelectDelete(db, pTable->pSelect);
-#ifndef SQLITE_OMIT_CHECK
-  sqlite3ExprDelete(db, pTable->pCheck);
-#endif
+  sqlite3ExprListDelete(db, pTable->pCheck);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   sqlite3VtabClear(db, pTable);
 #endif
   sqlite3DbFree(db, pTable);
+
+  /* Verify that no lookaside memory was used by schema tables */
+  assert( nLookaside==0 || nLookaside==db->lookaside.nOut );
+}
+SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
+  /* Do not delete the table until the reference count reaches zero. */
+  if( !pTable ) return;
+  if( ((!db || db->pnBytesFreed==0) && (--pTable->nRef)>0) ) return;
+  deleteTable(db, pTable);
 }
 
+
 /*
 ** Unlink the given table from the hash tables and the delete the
 ** table structure with all its indices and foreign keys.
@@ -80000,8 +98047,7 @@ SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   testcase( zTabName[0]==0 );  /* Zero-length table names are allowed */
   pDb = &db->aDb[iDb];
-  p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName,
-                        sqlite3Strlen30(zTabName),0);
+  p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName, 0);
   sqlite3DeleteTable(db, p);
   db->flags |= SQLITE_InternChanges;
 }
@@ -80037,8 +98083,7 @@ SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3 *db, Token *pName){
 SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *p, int iDb){
   Vdbe *v = sqlite3GetVdbe(p);
   sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
-  sqlite3VdbeAddOp3(v, OP_OpenWrite, 0, MASTER_ROOT, iDb);
-  sqlite3VdbeChangeP4(v, -1, (char *)5, P4_INT32);  /* 5 column table */
+  sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, MASTER_ROOT, iDb, 5);
   if( p->nTab==0 ){
     p->nTab = 1;
   }
@@ -80054,12 +98099,8 @@ SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *db, const char *zName){
   int i = -1;         /* Database number */
   if( zName ){
     Db *pDb;
-    int n = sqlite3Strlen30(zName);
     for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
-      if( (!OMIT_TEMPDB || i!=1 ) && n==sqlite3Strlen30(pDb->zName) && 
-          0==sqlite3StrICmp(pDb->zName, zName) ){
-        break;
-      }
+      if( 0==sqlite3StrICmp(pDb->zName, zName) ) break;
     }
   }
   return i;
@@ -80105,17 +98146,16 @@ SQLITE_PRIVATE int sqlite3TwoPartName(
   int iDb;                    /* Database holding the object */
   sqlite3 *db = pParse->db;
 
-  if( ALWAYS(pName2!=0) && pName2->n>0 ){
+  assert( pName2!=0 );
+  if( pName2->n>0 ){
     if( db->init.busy ) {
       sqlite3ErrorMsg(pParse, "corrupt database");
-      pParse->nErr++;
       return -1;
     }
     *pUnqual = pName2;
     iDb = sqlite3FindDb(db, pName1);
     if( iDb<0 ){
       sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
-      pParse->nErr++;
       return -1;
     }
   }else{
@@ -80144,6 +98184,27 @@ SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *pParse, const char *zName){
 }
 
 /*
+** Return the PRIMARY KEY index of a table
+*/
+SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table *pTab){
+  Index *p;
+  for(p=pTab->pIndex; p && !IsPrimaryKeyIndex(p); p=p->pNext){}
+  return p;
+}
+
+/*
+** Return the column of index pIdx that corresponds to table
+** column iCol.  Return -1 if not found.
+*/
+SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index *pIdx, i16 iCol){
+  int i;
+  for(i=0; i<pIdx->nColumn; i++){
+    if( iCol==pIdx->aiColumn[i] ) return i;
+  }
+  return -1;
+}
+
+/*
 ** Begin constructing a new table representation in memory.  This is
 ** the first of several action routines that get called in response
 ** to a CREATE TABLE statement.  In particular, this routine is called
@@ -80175,62 +98236,46 @@ SQLITE_PRIVATE void sqlite3StartTable(
   int iDb;         /* Database number to create the table in */
   Token *pName;    /* Unqualified name of the table to create */
 
-  /* The table or view name to create is passed to this routine via tokens
-  ** pName1 and pName2. If the table name was fully qualified, for example:
-  **
-  ** CREATE TABLE xxx.yyy (...);
-  ** 
-  ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
-  ** the table name is not fully qualified, i.e.:
-  **
-  ** CREATE TABLE yyy(...);
-  **
-  ** Then pName1 is set to "yyy" and pName2 is "".
-  **
-  ** The call below sets the pName pointer to point at the token (pName1 or
-  ** pName2) that stores the unqualified table name. The variable iDb is
-  ** set to the index of the database that the table or view is to be
-  ** created in.
-  */
-  iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
-  if( iDb<0 ) return;
-  if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
-    /* If creating a temp table, the name may not be qualified. Unless 
-    ** the database name is "temp" anyway.  */
-    sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
-    return;
+  if( db->init.busy && db->init.newTnum==1 ){
+    /* Special case:  Parsing the sqlite_master or sqlite_temp_master schema */
+    iDb = db->init.iDb;
+    zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));
+    pName = pName1;
+  }else{
+    /* The common case */
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+    if( iDb<0 ) return;
+    if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
+      /* If creating a temp table, the name may not be qualified. Unless 
+      ** the database name is "temp" anyway.  */
+      sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
+      return;
+    }
+    if( !OMIT_TEMPDB && isTemp ) iDb = 1;
+    zName = sqlite3NameFromToken(db, pName);
   }
-  if( !OMIT_TEMPDB && isTemp ) iDb = 1;
-
   pParse->sNameToken = *pName;
-  zName = sqlite3NameFromToken(db, pName);
   if( zName==0 ) return;
   if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
     goto begin_table_error;
   }
   if( db->init.iDb==1 ) isTemp = 1;
 #ifndef SQLITE_OMIT_AUTHORIZATION
-  assert( (isTemp & 1)==isTemp );
+  assert( isTemp==0 || isTemp==1 );
+  assert( isView==0 || isView==1 );
   {
-    int code;
+    static const u8 aCode[] = {
+       SQLITE_CREATE_TABLE,
+       SQLITE_CREATE_TEMP_TABLE,
+       SQLITE_CREATE_VIEW,
+       SQLITE_CREATE_TEMP_VIEW
+    };
     char *zDb = db->aDb[iDb].zName;
     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
       goto begin_table_error;
     }
-    if( isView ){
-      if( !OMIT_TEMPDB && isTemp ){
-        code = SQLITE_CREATE_TEMP_VIEW;
-      }else{
-        code = SQLITE_CREATE_VIEW;
-      }
-    }else{
-      if( !OMIT_TEMPDB && isTemp ){
-        code = SQLITE_CREATE_TEMP_TABLE;
-      }else{
-        code = SQLITE_CREATE_TABLE;
-      }
-    }
-    if( !isVirtual && sqlite3AuthCheck(pParse, code, zName, 0, zDb) ){
+    if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],
+                                       zName, 0, zDb) ){
       goto begin_table_error;
     }
   }
@@ -80253,7 +98298,7 @@ SQLITE_PRIVATE void sqlite3StartTable(
       if( !noErr ){
         sqlite3ErrorMsg(pParse, "table %T already exists", pName);
       }else{
-        assert( !db->init.busy );
+        assert( !db->init.busy || CORRUPT_DB );
         sqlite3CodeVerifySchema(pParse, iDb);
       }
       goto begin_table_error;
@@ -80266,8 +98311,8 @@ SQLITE_PRIVATE void sqlite3StartTable(
 
   pTable = sqlite3DbMallocZero(db, sizeof(Table));
   if( pTable==0 ){
-    db->mallocFailed = 1;
-    pParse->rc = SQLITE_NOMEM;
+    assert( db->mallocFailed );
+    pParse->rc = SQLITE_NOMEM_BKPT;
     pParse->nErr++;
     goto begin_table_error;
   }
@@ -80275,7 +98320,7 @@ SQLITE_PRIVATE void sqlite3StartTable(
   pTable->iPKey = -1;
   pTable->pSchema = db->aDb[iDb].pSchema;
   pTable->nRef = 1;
-  pTable->nRowEst = 1000000;
+  pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
   assert( pParse->pNewTable==0 );
   pParse->pNewTable = pTable;
 
@@ -80299,10 +98344,12 @@ SQLITE_PRIVATE void sqlite3StartTable(
   ** now.
   */
   if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
-    int j1;
+    int addr1;
     int fileFormat;
     int reg1, reg2, reg3;
-    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    /* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */
+    static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     if( isVirtual ){
@@ -80318,14 +98365,12 @@ SQLITE_PRIVATE void sqlite3StartTable(
     reg3 = ++pParse->nMem;
     sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
     sqlite3VdbeUsesBtree(v, iDb);
-    j1 = sqlite3VdbeAddOp1(v, OP_If, reg3);
+    addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
     fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                   1 : SQLITE_MAX_FILE_FORMAT;
-    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, reg3);
-    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, reg3);
-    sqlite3VdbeJumpHere(v, j1);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
+    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
+    sqlite3VdbeJumpHere(v, addr1);
 
     /* This just creates a place-holder record in the sqlite_master table.
     ** The record created does not contain anything yet.  It will be replaced
@@ -80342,11 +98387,11 @@ SQLITE_PRIVATE void sqlite3StartTable(
     }else
 #endif
     {
-      sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
+      pParse->addrCrTab = sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
     }
     sqlite3OpenMasterTable(pParse, iDb);
     sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
-    sqlite3VdbeAddOp2(v, OP_Null, 0, reg3);
+    sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
     sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
     sqlite3VdbeAddOp0(v, OP_Close);
@@ -80361,18 +98406,19 @@ begin_table_error:
   return;
 }
 
-/*
-** This macro is used to compare two strings in a case-insensitive manner.
-** It is slightly faster than calling sqlite3StrICmp() directly, but
-** produces larger code.
-**
-** WARNING: This macro is not compatible with the strcmp() family. It
-** returns true if the two strings are equal, otherwise false.
+/* Set properties of a table column based on the (magical)
+** name of the column.
 */
-#define STRICMP(x, y) (\
-sqlite3UpperToLower[*(unsigned char *)(x)]==   \
-sqlite3UpperToLower[*(unsigned char *)(y)]     \
-&& sqlite3StrICmp((x)+1,(y)+1)==0 )
+#if SQLITE_ENABLE_HIDDEN_COLUMNS
+SQLITE_PRIVATE void sqlite3ColumnPropertiesFromName(Table *pTab, Column *pCol){
+  if( sqlite3_strnicmp(pCol->zName, "__hidden__", 10)==0 ){
+    pCol->colFlags |= COLFLAG_HIDDEN;
+  }else if( pTab && pCol!=pTab->aCol && (pCol[-1].colFlags & COLFLAG_HIDDEN) ){
+    pTab->tabFlags |= TF_OOOHidden;
+  }
+}
+#endif
+
 
 /*
 ** Add a new column to the table currently being constructed.
@@ -80382,10 +98428,11 @@ sqlite3UpperToLower[*(unsigned char *)(y)]     \
 ** first to get things going.  Then this routine is called for each
 ** column.
 */
-SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
+SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){
   Table *p;
   int i;
   char *z;
+  char *zType;
   Column *pCol;
   sqlite3 *db = pParse->db;
   if( (p = pParse->pNewTable)==0 ) return;
@@ -80395,10 +98442,13 @@ SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
     return;
   }
 #endif
-  z = sqlite3NameFromToken(db, pName);
+  z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
   if( z==0 ) return;
+  memcpy(z, pName->z, pName->n);
+  z[pName->n] = 0;
+  sqlite3Dequote(z);
   for(i=0; i<p->nCol; i++){
-    if( STRICMP(z, p->aCol[i].zName) ){
+    if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
       sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
       sqlite3DbFree(db, z);
       return;
@@ -80416,13 +98466,23 @@ SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName){
   pCol = &p->aCol[p->nCol];
   memset(pCol, 0, sizeof(p->aCol[0]));
   pCol->zName = z;
+  sqlite3ColumnPropertiesFromName(p, pCol);
  
-  /* If there is no type specified, columns have the default affinity
-  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
-  ** be called next to set pCol->affinity correctly.
-  */
-  pCol->affinity = SQLITE_AFF_NONE;
+  if( pType->n==0 ){
+    /* If there is no type specified, columns have the default affinity
+    ** 'BLOB'. */
+    pCol->affinity = SQLITE_AFF_BLOB;
+    pCol->szEst = 1;
+  }else{
+    zType = z + sqlite3Strlen30(z) + 1;
+    memcpy(zType, pType->z, pType->n);
+    zType[pType->n] = 0;
+    sqlite3Dequote(zType);
+    pCol->affinity = sqlite3AffinityType(zType, &pCol->szEst);
+    pCol->colFlags |= COLFLAG_HASTYPE;
+  }
   p->nCol++;
+  pParse->constraintName.n = 0;
 }
 
 /*
@@ -80455,7 +98515,7 @@ SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){
 ** 'CHAR'        | SQLITE_AFF_TEXT
 ** 'CLOB'        | SQLITE_AFF_TEXT
 ** 'TEXT'        | SQLITE_AFF_TEXT
-** 'BLOB'        | SQLITE_AFF_NONE
+** 'BLOB'        | SQLITE_AFF_BLOB
 ** 'REAL'        | SQLITE_AFF_REAL
 ** 'FLOA'        | SQLITE_AFF_REAL
 ** 'DOUB'        | SQLITE_AFF_REAL
@@ -80463,22 +98523,26 @@ SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){
 ** If none of the substrings in the above table are found,
 ** SQLITE_AFF_NUMERIC is returned.
 */
-SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn){
+SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, u8 *pszEst){
   u32 h = 0;
   char aff = SQLITE_AFF_NUMERIC;
+  const char *zChar = 0;
 
-  if( zIn ) while( zIn[0] ){
+  assert( zIn!=0 );
+  while( zIn[0] ){
     h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];
     zIn++;
     if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
-      aff = SQLITE_AFF_TEXT; 
+      aff = SQLITE_AFF_TEXT;
+      zChar = zIn;
     }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
       aff = SQLITE_AFF_TEXT;
     }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
       aff = SQLITE_AFF_TEXT;
     }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
         && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
-      aff = SQLITE_AFF_NONE;
+      aff = SQLITE_AFF_BLOB;
+      if( zIn[0]=='(' ) zChar = zIn;
 #ifndef SQLITE_OMIT_FLOATING_POINT
     }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
         && aff==SQLITE_AFF_NUMERIC ){
@@ -80496,31 +98560,32 @@ SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn){
     }
   }
 
+  /* If pszEst is not NULL, store an estimate of the field size.  The
+  ** estimate is scaled so that the size of an integer is 1.  */
+  if( pszEst ){
+    *pszEst = 1;   /* default size is approx 4 bytes */
+    if( aff<SQLITE_AFF_NUMERIC ){
+      if( zChar ){
+        while( zChar[0] ){
+          if( sqlite3Isdigit(zChar[0]) ){
+            int v = 0;
+            sqlite3GetInt32(zChar, &v);
+            v = v/4 + 1;
+            if( v>255 ) v = 255;
+            *pszEst = v; /* BLOB(k), VARCHAR(k), CHAR(k) -> r=(k/4+1) */
+            break;
+          }
+          zChar++;
+        }
+      }else{
+        *pszEst = 5;   /* BLOB, TEXT, CLOB -> r=5  (approx 20 bytes)*/
+      }
+    }
+  }
   return aff;
 }
 
 /*
-** This routine is called by the parser while in the middle of
-** parsing a CREATE TABLE statement.  The pFirst token is the first
-** token in the sequence of tokens that describe the type of the
-** column currently under construction.   pLast is the last token
-** in the sequence.  Use this information to construct a string
-** that contains the typename of the column and store that string
-** in zType.
-*/ 
-SQLITE_PRIVATE void sqlite3AddColumnType(Parse *pParse, Token *pType){
-  Table *p;
-  Column *pCol;
-
-  p = pParse->pNewTable;
-  if( p==0 || NEVER(p->nCol<1) ) return;
-  pCol = &p->aCol[p->nCol-1];
-  assert( pCol->zType==0 );
-  pCol->zType = sqlite3NameFromToken(pParse->db, pType);
-  pCol->affinity = sqlite3AffinityType(pCol->zType);
-}
-
-/*
 ** The expression is the default value for the most recently added column
 ** of the table currently under construction.
 **
@@ -80537,7 +98602,7 @@ SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse *pParse, ExprSpan *pSpan){
   p = pParse->pNewTable;
   if( p!=0 ){
     pCol = &(p->aCol[p->nCol-1]);
-    if( !sqlite3ExprIsConstantOrFunction(pSpan->pExpr) ){
+    if( !sqlite3ExprIsConstantOrFunction(pSpan->pExpr, db->init.busy) ){
       sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
           pCol->zName);
     }else{
@@ -80545,17 +98610,46 @@ SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse *pParse, ExprSpan *pSpan){
       ** tokens that point to volatile memory. The 'span' of the expression
       ** is required by pragma table_info.
       */
+      Expr x;
       sqlite3ExprDelete(db, pCol->pDflt);
-      pCol->pDflt = sqlite3ExprDup(db, pSpan->pExpr, EXPRDUP_REDUCE);
-      sqlite3DbFree(db, pCol->zDflt);
-      pCol->zDflt = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
-                                     (int)(pSpan->zEnd - pSpan->zStart));
+      memset(&x, 0, sizeof(x));
+      x.op = TK_SPAN;
+      x.u.zToken = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
+                                    (int)(pSpan->zEnd - pSpan->zStart));
+      x.pLeft = pSpan->pExpr;
+      x.flags = EP_Skip;
+      pCol->pDflt = sqlite3ExprDup(db, &x, EXPRDUP_REDUCE);
+      sqlite3DbFree(db, x.u.zToken);
     }
   }
   sqlite3ExprDelete(db, pSpan->pExpr);
 }
 
 /*
+** Backwards Compatibility Hack:
+** 
+** Historical versions of SQLite accepted strings as column names in
+** indexes and PRIMARY KEY constraints and in UNIQUE constraints.  Example:
+**
+**     CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)
+**     CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);
+**
+** This is goofy.  But to preserve backwards compatibility we continue to
+** accept it.  This routine does the necessary conversion.  It converts
+** the expression given in its argument from a TK_STRING into a TK_ID
+** if the expression is just a TK_STRING with an optional COLLATE clause.
+** If the epxression is anything other than TK_STRING, the expression is
+** unchanged.
+*/
+static void sqlite3StringToId(Expr *p){
+  if( p->op==TK_STRING ){
+    p->op = TK_ID;
+  }else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){
+    p->pLeft->op = TK_ID;
+  }
+}
+
+/*
 ** Designate the PRIMARY KEY for the table.  pList is a list of names 
 ** of columns that form the primary key.  If pList is NULL, then the
 ** most recently added column of the table is the primary key.
@@ -80581,9 +98675,10 @@ SQLITE_PRIVATE void sqlite3AddPrimaryKey(
   int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */
 ){
   Table *pTab = pParse->pNewTable;
-  char *zType = 0;
+  Column *pCol = 0;
   int iCol = -1, i;
-  if( pTab==0 || IN_DECLARE_VTAB ) goto primary_key_exit;
+  int nTerm;
+  if( pTab==0 ) goto primary_key_exit;
   if( pTab->tabFlags & TF_HasPrimaryKey ){
     sqlite3ErrorMsg(pParse, 
       "table \"%s\" has more than one primary key", pTab->zName);
@@ -80592,40 +98687,45 @@ SQLITE_PRIVATE void sqlite3AddPrimaryKey(
   pTab->tabFlags |= TF_HasPrimaryKey;
   if( pList==0 ){
     iCol = pTab->nCol - 1;
-    pTab->aCol[iCol].isPrimKey = 1;
+    pCol = &pTab->aCol[iCol];
+    pCol->colFlags |= COLFLAG_PRIMKEY;
+    nTerm = 1;
   }else{
-    for(i=0; i<pList->nExpr; i++){
-      for(iCol=0; iCol<pTab->nCol; iCol++){
-        if( sqlite3StrICmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
-          break;
+    nTerm = pList->nExpr;
+    for(i=0; i<nTerm; i++){
+      Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);
+      assert( pCExpr!=0 );
+      sqlite3StringToId(pCExpr);
+      if( pCExpr->op==TK_ID ){
+        const char *zCName = pCExpr->u.zToken;
+        for(iCol=0; iCol<pTab->nCol; iCol++){
+          if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){
+            pCol = &pTab->aCol[iCol];
+            pCol->colFlags |= COLFLAG_PRIMKEY;
+            break;
+          }
         }
       }
-      if( iCol<pTab->nCol ){
-        pTab->aCol[iCol].isPrimKey = 1;
-      }
     }
-    if( pList->nExpr>1 ) iCol = -1;
   }
-  if( iCol>=0 && iCol<pTab->nCol ){
-    zType = pTab->aCol[iCol].zType;
-  }
-  if( zType && sqlite3StrICmp(zType, "INTEGER")==0
-        && sortOrder==SQLITE_SO_ASC ){
+  if( nTerm==1
+   && pCol
+   && sqlite3StrICmp(sqlite3ColumnType(pCol,""), "INTEGER")==0
+   && sortOrder!=SQLITE_SO_DESC
+  ){
     pTab->iPKey = iCol;
     pTab->keyConf = (u8)onError;
     assert( autoInc==0 || autoInc==1 );
     pTab->tabFlags |= autoInc*TF_Autoincrement;
+    if( pList ) pParse->iPkSortOrder = pList->a[0].sortOrder;
   }else if( autoInc ){
 #ifndef SQLITE_OMIT_AUTOINCREMENT
     sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
        "INTEGER PRIMARY KEY");
 #endif
   }else{
-    Index *p;
-    p = sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
-    if( p ){
-      p->autoIndex = 2;
-    }
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
+                           0, sortOrder, 0, SQLITE_IDXTYPE_PRIMARYKEY);
     pList = 0;
   }
 
@@ -80641,15 +98741,20 @@ SQLITE_PRIVATE void sqlite3AddCheckConstraint(
   Parse *pParse,    /* Parsing context */
   Expr *pCheckExpr  /* The check expression */
 ){
-  sqlite3 *db = pParse->db;
 #ifndef SQLITE_OMIT_CHECK
   Table *pTab = pParse->pNewTable;
-  if( pTab && !IN_DECLARE_VTAB ){
-    pTab->pCheck = sqlite3ExprAnd(db, pTab->pCheck, pCheckExpr);
+  sqlite3 *db = pParse->db;
+  if( pTab && !IN_DECLARE_VTAB
+   && !sqlite3BtreeIsReadonly(db->aDb[db->init.iDb].pBt)
+  ){
+    pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);
+    if( pParse->constraintName.n ){
+      sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);
+    }
   }else
 #endif
   {
-    sqlite3ExprDelete(db, pCheckExpr);
+    sqlite3ExprDelete(pParse->db, pCheckExpr);
   }
 }
 
@@ -80671,6 +98776,7 @@ SQLITE_PRIVATE void sqlite3AddCollateType(Parse *pParse, Token *pToken){
 
   if( sqlite3LocateCollSeq(pParse, zColl) ){
     Index *pIdx;
+    sqlite3DbFree(db, p->aCol[i].zColl);
     p->aCol[i].zColl = zColl;
   
     /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
@@ -80678,7 +98784,7 @@ SQLITE_PRIVATE void sqlite3AddCollateType(Parse *pParse, Token *pToken){
     ** collation type was added. Correct this if it is the case.
     */
     for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
-      assert( pIdx->nColumn==1 );
+      assert( pIdx->nKeyCol==1 );
       if( pIdx->aiColumn[0]==i ){
         pIdx->azColl[0] = p->aCol[i].zColl;
       }
@@ -80716,10 +98822,7 @@ SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){
 
   pColl = sqlite3FindCollSeq(db, enc, zName, initbusy);
   if( !initbusy && (!pColl || !pColl->xCmp) ){
-    pColl = sqlite3GetCollSeq(db, enc, pColl, zName);
-    if( !pColl ){
-      sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
-    }
+    pColl = sqlite3GetCollSeq(pParse, enc, pColl, zName);
   }
 
   return pColl;
@@ -80743,13 +98846,11 @@ SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){
 ** 1 chance in 2^32.  So we're safe enough.
 */
 SQLITE_PRIVATE void sqlite3ChangeCookie(Parse *pParse, int iDb){
-  int r1 = sqlite3GetTempReg(pParse);
   sqlite3 *db = pParse->db;
   Vdbe *v = pParse->pVdbe;
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, r1);
-  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, r1);
-  sqlite3ReleaseTempReg(pParse, r1);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, 
+                    db->aDb[iDb].pSchema->schema_cookie+1);
 }
 
 /*
@@ -80789,10 +98890,10 @@ static void identPut(char *z, int *pIdx, char *zSignedIdent){
   for(j=0; zIdent[j]; j++){
     if( !sqlite3Isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
   }
-  needQuote = sqlite3Isdigit(zIdent[0]) || sqlite3KeywordCode(zIdent, j)!=TK_ID;
-  if( !needQuote ){
-    needQuote = zIdent[j];
-  }
+  needQuote = sqlite3Isdigit(zIdent[0])
+            || sqlite3KeywordCode(zIdent, j)!=TK_ID
+            || zIdent[j]!=0
+            || j==0;
 
   if( needQuote ) z[i++] = '"';
   for(j=0; zIdent[j]; j++){
@@ -80831,7 +98932,7 @@ static char *createTableStmt(sqlite3 *db, Table *p){
   n += 35 + 6*p->nCol;
   zStmt = sqlite3DbMallocRaw(0, n);
   if( zStmt==0 ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     return 0;
   }
   sqlite3_snprintf(n, zStmt, "CREATE TABLE ");
@@ -80840,8 +98941,8 @@ static char *createTableStmt(sqlite3 *db, Table *p){
   zStmt[k++] = '(';
   for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
     static const char * const azType[] = {
+        /* SQLITE_AFF_BLOB    */ "",
         /* SQLITE_AFF_TEXT    */ " TEXT",
-        /* SQLITE_AFF_NONE    */ "",
         /* SQLITE_AFF_NUMERIC */ " NUM",
         /* SQLITE_AFF_INTEGER */ " INT",
         /* SQLITE_AFF_REAL    */ " REAL"
@@ -80853,18 +98954,18 @@ static char *createTableStmt(sqlite3 *db, Table *p){
     k += sqlite3Strlen30(&zStmt[k]);
     zSep = zSep2;
     identPut(zStmt, &k, pCol->zName);
-    assert( pCol->affinity-SQLITE_AFF_TEXT >= 0 );
-    assert( pCol->affinity-SQLITE_AFF_TEXT < ArraySize(azType) );
+    assert( pCol->affinity-SQLITE_AFF_BLOB >= 0 );
+    assert( pCol->affinity-SQLITE_AFF_BLOB < ArraySize(azType) );
+    testcase( pCol->affinity==SQLITE_AFF_BLOB );
     testcase( pCol->affinity==SQLITE_AFF_TEXT );
-    testcase( pCol->affinity==SQLITE_AFF_NONE );
     testcase( pCol->affinity==SQLITE_AFF_NUMERIC );
     testcase( pCol->affinity==SQLITE_AFF_INTEGER );
     testcase( pCol->affinity==SQLITE_AFF_REAL );
     
-    zType = azType[pCol->affinity - SQLITE_AFF_TEXT];
+    zType = azType[pCol->affinity - SQLITE_AFF_BLOB];
     len = sqlite3Strlen30(zType);
-    assert( pCol->affinity==SQLITE_AFF_NONE 
-            || pCol->affinity==sqlite3AffinityType(zType) );
+    assert( pCol->affinity==SQLITE_AFF_BLOB 
+            || pCol->affinity==sqlite3AffinityType(zType, 0) );
     memcpy(&zStmt[k], zType, len);
     k += len;
     assert( k<=n );
@@ -80874,6 +98975,219 @@ static char *createTableStmt(sqlite3 *db, Table *p){
 }
 
 /*
+** Resize an Index object to hold N columns total.  Return SQLITE_OK
+** on success and SQLITE_NOMEM on an OOM error.
+*/
+static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){
+  char *zExtra;
+  int nByte;
+  if( pIdx->nColumn>=N ) return SQLITE_OK;
+  assert( pIdx->isResized==0 );
+  nByte = (sizeof(char*) + sizeof(i16) + 1)*N;
+  zExtra = sqlite3DbMallocZero(db, nByte);
+  if( zExtra==0 ) return SQLITE_NOMEM_BKPT;
+  memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);
+  pIdx->azColl = (const char**)zExtra;
+  zExtra += sizeof(char*)*N;
+  memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);
+  pIdx->aiColumn = (i16*)zExtra;
+  zExtra += sizeof(i16)*N;
+  memcpy(zExtra, pIdx->aSortOrder, pIdx->nColumn);
+  pIdx->aSortOrder = (u8*)zExtra;
+  pIdx->nColumn = N;
+  pIdx->isResized = 1;
+  return SQLITE_OK;
+}
+
+/*
+** Estimate the total row width for a table.
+*/
+static void estimateTableWidth(Table *pTab){
+  unsigned wTable = 0;
+  const Column *pTabCol;
+  int i;
+  for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){
+    wTable += pTabCol->szEst;
+  }
+  if( pTab->iPKey<0 ) wTable++;
+  pTab->szTabRow = sqlite3LogEst(wTable*4);
+}
+
+/*
+** Estimate the average size of a row for an index.
+*/
+static void estimateIndexWidth(Index *pIdx){
+  unsigned wIndex = 0;
+  int i;
+  const Column *aCol = pIdx->pTable->aCol;
+  for(i=0; i<pIdx->nColumn; i++){
+    i16 x = pIdx->aiColumn[i];
+    assert( x<pIdx->pTable->nCol );
+    wIndex += x<0 ? 1 : aCol[pIdx->aiColumn[i]].szEst;
+  }
+  pIdx->szIdxRow = sqlite3LogEst(wIndex*4);
+}
+
+/* Return true if value x is found any of the first nCol entries of aiCol[]
+*/
+static int hasColumn(const i16 *aiCol, int nCol, int x){
+  while( nCol-- > 0 ) if( x==*(aiCol++) ) return 1;
+  return 0;
+}
+
+/*
+** This routine runs at the end of parsing a CREATE TABLE statement that
+** has a WITHOUT ROWID clause.  The job of this routine is to convert both
+** internal schema data structures and the generated VDBE code so that they
+** are appropriate for a WITHOUT ROWID table instead of a rowid table.
+** Changes include:
+**
+**     (1)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
+**     (2)  Convert the OP_CreateTable into an OP_CreateIndex.  There is
+**          no rowid btree for a WITHOUT ROWID.  Instead, the canonical
+**          data storage is a covering index btree.
+**     (3)  Bypass the creation of the sqlite_master table entry
+**          for the PRIMARY KEY as the primary key index is now
+**          identified by the sqlite_master table entry of the table itself.
+**     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the
+**          schema to the rootpage from the main table.
+**     (5)  Add all table columns to the PRIMARY KEY Index object
+**          so that the PRIMARY KEY is a covering index.  The surplus
+**          columns are part of KeyInfo.nXField and are not used for
+**          sorting or lookup or uniqueness checks.
+**     (6)  Replace the rowid tail on all automatically generated UNIQUE
+**          indices with the PRIMARY KEY columns.
+**
+** For virtual tables, only (1) is performed.
+*/
+static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
+  Index *pIdx;
+  Index *pPk;
+  int nPk;
+  int i, j;
+  sqlite3 *db = pParse->db;
+  Vdbe *v = pParse->pVdbe;
+
+  /* Mark every PRIMARY KEY column as NOT NULL (except for imposter tables)
+  */
+  if( !db->init.imposterTable ){
+    for(i=0; i<pTab->nCol; i++){
+      if( (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){
+        pTab->aCol[i].notNull = OE_Abort;
+      }
+    }
+  }
+
+  /* The remaining transformations only apply to b-tree tables, not to
+  ** virtual tables */
+  if( IN_DECLARE_VTAB ) return;
+
+  /* Convert the OP_CreateTable opcode that would normally create the
+  ** root-page for the table into an OP_CreateIndex opcode.  The index
+  ** created will become the PRIMARY KEY index.
+  */
+  if( pParse->addrCrTab ){
+    assert( v );
+    sqlite3VdbeChangeOpcode(v, pParse->addrCrTab, OP_CreateIndex);
+  }
+
+  /* Locate the PRIMARY KEY index.  Or, if this table was originally
+  ** an INTEGER PRIMARY KEY table, create a new PRIMARY KEY index. 
+  */
+  if( pTab->iPKey>=0 ){
+    ExprList *pList;
+    Token ipkToken;
+    sqlite3TokenInit(&ipkToken, pTab->aCol[pTab->iPKey].zName);
+    pList = sqlite3ExprListAppend(pParse, 0, 
+                  sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));
+    if( pList==0 ) return;
+    pList->a[0].sortOrder = pParse->iPkSortOrder;
+    assert( pParse->pNewTable==pTab );
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0,
+                       SQLITE_IDXTYPE_PRIMARYKEY);
+    if( db->mallocFailed ) return;
+    pPk = sqlite3PrimaryKeyIndex(pTab);
+    pTab->iPKey = -1;
+  }else{
+    pPk = sqlite3PrimaryKeyIndex(pTab);
+
+    /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master
+    ** table entry. This is only required if currently generating VDBE
+    ** code for a CREATE TABLE (not when parsing one as part of reading
+    ** a database schema).  */
+    if( v ){
+      assert( db->init.busy==0 );
+      sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);
+    }
+
+    /*
+    ** Remove all redundant columns from the PRIMARY KEY.  For example, change
+    ** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)".  Later
+    ** code assumes the PRIMARY KEY contains no repeated columns.
+    */
+    for(i=j=1; i<pPk->nKeyCol; i++){
+      if( hasColumn(pPk->aiColumn, j, pPk->aiColumn[i]) ){
+        pPk->nColumn--;
+      }else{
+        pPk->aiColumn[j++] = pPk->aiColumn[i];
+      }
+    }
+    pPk->nKeyCol = j;
+  }
+  assert( pPk!=0 );
+  pPk->isCovering = 1;
+  if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
+  nPk = pPk->nKeyCol;
+
+  /* The root page of the PRIMARY KEY is the table root page */
+  pPk->tnum = pTab->tnum;
+
+  /* Update the in-memory representation of all UNIQUE indices by converting
+  ** the final rowid column into one or more columns of the PRIMARY KEY.
+  */
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    int n;
+    if( IsPrimaryKeyIndex(pIdx) ) continue;
+    for(i=n=0; i<nPk; i++){
+      if( !hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) ) n++;
+    }
+    if( n==0 ){
+      /* This index is a superset of the primary key */
+      pIdx->nColumn = pIdx->nKeyCol;
+      continue;
+    }
+    if( resizeIndexObject(db, pIdx, pIdx->nKeyCol+n) ) return;
+    for(i=0, j=pIdx->nKeyCol; i<nPk; i++){
+      if( !hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) ){
+        pIdx->aiColumn[j] = pPk->aiColumn[i];
+        pIdx->azColl[j] = pPk->azColl[i];
+        j++;
+      }
+    }
+    assert( pIdx->nColumn>=pIdx->nKeyCol+n );
+    assert( pIdx->nColumn>=j );
+  }
+
+  /* Add all table columns to the PRIMARY KEY index
+  */
+  if( nPk<pTab->nCol ){
+    if( resizeIndexObject(db, pPk, pTab->nCol) ) return;
+    for(i=0, j=nPk; i<pTab->nCol; i++){
+      if( !hasColumn(pPk->aiColumn, j, i) ){
+        assert( j<pPk->nColumn );
+        pPk->aiColumn[j] = i;
+        pPk->azColl[j] = sqlite3StrBINARY;
+        j++;
+      }
+    }
+    assert( pPk->nColumn==j );
+    assert( pTab->nCol==j );
+  }else{
+    pPk->nColumn = pTab->nCol;
+  }
+}
+
+/*
 ** This routine is called to report the final ")" that terminates
 ** a CREATE TABLE statement.
 **
@@ -80896,53 +99210,67 @@ static char *createTableStmt(sqlite3 *db, Table *p){
 SQLITE_PRIVATE void sqlite3EndTable(
   Parse *pParse,          /* Parse context */
   Token *pCons,           /* The ',' token after the last column defn. */
-  Token *pEnd,            /* The final ')' token in the CREATE TABLE */
+  Token *pEnd,            /* The ')' before options in the CREATE TABLE */
+  u8 tabOpts,             /* Extra table options. Usually 0. */
   Select *pSelect         /* Select from a "CREATE ... AS SELECT" */
 ){
-  Table *p;
-  sqlite3 *db = pParse->db;
-  int iDb;
+  Table *p;                 /* The new table */
+  sqlite3 *db = pParse->db; /* The database connection */
+  int iDb;                  /* Database in which the table lives */
+  Index *pIdx;              /* An implied index of the table */
 
-  if( (pEnd==0 && pSelect==0) || db->mallocFailed ){
+  if( pEnd==0 && pSelect==0 ){
     return;
   }
+  assert( !db->mallocFailed );
   p = pParse->pNewTable;
   if( p==0 ) return;
 
   assert( !db->init.busy || !pSelect );
 
+  /* If the db->init.busy is 1 it means we are reading the SQL off the
+  ** "sqlite_master" or "sqlite_temp_master" table on the disk.
+  ** So do not write to the disk again.  Extract the root page number
+  ** for the table from the db->init.newTnum field.  (The page number
+  ** should have been put there by the sqliteOpenCb routine.)
+  **
+  ** If the root page number is 1, that means this is the sqlite_master
+  ** table itself.  So mark it read-only.
+  */
+  if( db->init.busy ){
+    p->tnum = db->init.newTnum;
+    if( p->tnum==1 ) p->tabFlags |= TF_Readonly;
+  }
+
+  /* Special processing for WITHOUT ROWID Tables */
+  if( tabOpts & TF_WithoutRowid ){
+    if( (p->tabFlags & TF_Autoincrement) ){
+      sqlite3ErrorMsg(pParse,
+          "AUTOINCREMENT not allowed on WITHOUT ROWID tables");
+      return;
+    }
+    if( (p->tabFlags & TF_HasPrimaryKey)==0 ){
+      sqlite3ErrorMsg(pParse, "PRIMARY KEY missing on table %s", p->zName);
+    }else{
+      p->tabFlags |= TF_WithoutRowid | TF_NoVisibleRowid;
+      convertToWithoutRowidTable(pParse, p);
+    }
+  }
+
   iDb = sqlite3SchemaToIndex(db, p->pSchema);
 
 #ifndef SQLITE_OMIT_CHECK
   /* Resolve names in all CHECK constraint expressions.
   */
   if( p->pCheck ){
-    SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
-    NameContext sNC;                /* Name context for pParse->pNewTable */
-
-    memset(&sNC, 0, sizeof(sNC));
-    memset(&sSrc, 0, sizeof(sSrc));
-    sSrc.nSrc = 1;
-    sSrc.a[0].zName = p->zName;
-    sSrc.a[0].pTab = p;
-    sSrc.a[0].iCursor = -1;
-    sNC.pParse = pParse;
-    sNC.pSrcList = &sSrc;
-    sNC.isCheck = 1;
-    if( sqlite3ResolveExprNames(&sNC, p->pCheck) ){
-      return;
-    }
+    sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
   }
 #endif /* !defined(SQLITE_OMIT_CHECK) */
 
-  /* If the db->init.busy is 1 it means we are reading the SQL off the
-  ** "sqlite_master" or "sqlite_temp_master" table on the disk.
-  ** So do not write to the disk again.  Extract the root page number
-  ** for the table from the db->init.newTnum field.  (The page number
-  ** should have been put there by the sqliteOpenCb routine.)
-  */
-  if( db->init.busy ){
-    p->tnum = db->init.newTnum;
+  /* Estimate the average row size for the table and for all implied indices */
+  estimateTableWidth(p);
+  for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
+    estimateIndexWidth(pIdx);
   }
 
   /* If not initializing, then create a record for the new table
@@ -80992,33 +99320,55 @@ SQLITE_PRIVATE void sqlite3EndTable(
     ** be redundant.
     */
     if( pSelect ){
-      SelectDest dest;
-      Table *pSelTab;
-
+      SelectDest dest;    /* Where the SELECT should store results */
+      int regYield;       /* Register holding co-routine entry-point */
+      int addrTop;        /* Top of the co-routine */
+      int regRec;         /* A record to be insert into the new table */
+      int regRowid;       /* Rowid of the next row to insert */
+      int addrInsLoop;    /* Top of the loop for inserting rows */
+      Table *pSelTab;     /* A table that describes the SELECT results */
+
+      regYield = ++pParse->nMem;
+      regRec = ++pParse->nMem;
+      regRowid = ++pParse->nMem;
       assert(pParse->nTab==1);
+      sqlite3MayAbort(pParse);
       sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
-      sqlite3VdbeChangeP5(v, 1);
+      sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
       pParse->nTab = 2;
-      sqlite3SelectDestInit(&dest, SRT_Table, 1);
+      addrTop = sqlite3VdbeCurrentAddr(v) + 1;
+      sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
+      sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
       sqlite3Select(pParse, pSelect, &dest);
+      sqlite3VdbeEndCoroutine(v, regYield);
+      sqlite3VdbeJumpHere(v, addrTop - 1);
+      if( pParse->nErr ) return;
+      pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
+      if( pSelTab==0 ) return;
+      assert( p->aCol==0 );
+      p->nCol = pSelTab->nCol;
+      p->aCol = pSelTab->aCol;
+      pSelTab->nCol = 0;
+      pSelTab->aCol = 0;
+      sqlite3DeleteTable(db, pSelTab);
+      addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
+      VdbeCoverage(v);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);
+      sqlite3TableAffinity(v, p, 0);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);
+      sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);
+      sqlite3VdbeGoto(v, addrInsLoop);
+      sqlite3VdbeJumpHere(v, addrInsLoop);
       sqlite3VdbeAddOp1(v, OP_Close, 1);
-      if( pParse->nErr==0 ){
-        pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
-        if( pSelTab==0 ) return;
-        assert( p->aCol==0 );
-        p->nCol = pSelTab->nCol;
-        p->aCol = pSelTab->aCol;
-        pSelTab->nCol = 0;
-        pSelTab->aCol = 0;
-        sqlite3DeleteTable(db, pSelTab);
-      }
     }
 
     /* Compute the complete text of the CREATE statement */
     if( pSelect ){
       zStmt = createTableStmt(db, p);
     }else{
-      n = (int)(pEnd->z - pParse->sNameToken.z) + 1;
+      Token *pEnd2 = tabOpts ? &pParse->sLastToken : pEnd;
+      n = (int)(pEnd2->z - pParse->sNameToken.z);
+      if( pEnd2->z[0]!=';' ) n += pEnd2->n;
       zStmt = sqlite3MPrintf(db, 
           "CREATE %s %.*s", zType2, n, pParse->sNameToken.z
       );
@@ -81061,7 +99411,7 @@ SQLITE_PRIVATE void sqlite3EndTable(
 
     /* Reparse everything to update our internal data structures */
     sqlite3VdbeAddParseSchemaOp(v, iDb,
-               sqlite3MPrintf(db, "tbl_name='%q'", p->zName));
+           sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName));
   }
 
 
@@ -81071,15 +99421,13 @@ SQLITE_PRIVATE void sqlite3EndTable(
     Table *pOld;
     Schema *pSchema = p->pSchema;
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-    pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName,
-                             sqlite3Strlen30(p->zName),p);
+    pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);
     if( pOld ){
       assert( p==pOld );  /* Malloc must have failed inside HashInsert() */
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return;
     }
     pParse->pNewTable = 0;
-    db->nTable++;
     db->flags |= SQLITE_InternChanges;
 
 #ifndef SQLITE_OMIT_ALTERTABLE
@@ -81106,6 +99454,7 @@ SQLITE_PRIVATE void sqlite3CreateView(
   Token *pBegin,     /* The CREATE token that begins the statement */
   Token *pName1,     /* The token that holds the name of the view */
   Token *pName2,     /* The token that holds the name of the view */
+  ExprList *pCNames, /* Optional list of view column names */
   Select *pSelect,   /* A SELECT statement that will become the new view */
   int isTemp,        /* TRUE for a TEMPORARY view */
   int noErr          /* Suppress error messages if VIEW already exists */
@@ -81121,23 +99470,15 @@ SQLITE_PRIVATE void sqlite3CreateView(
 
   if( pParse->nVar>0 ){
     sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
-    sqlite3SelectDelete(db, pSelect);
-    return;
+    goto create_view_fail;
   }
   sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
   p = pParse->pNewTable;
-  if( p==0 || pParse->nErr ){
-    sqlite3SelectDelete(db, pSelect);
-    return;
-  }
+  if( p==0 || pParse->nErr ) goto create_view_fail;
   sqlite3TwoPartName(pParse, pName1, pName2, &pName);
   iDb = sqlite3SchemaToIndex(db, p->pSchema);
-  if( sqlite3FixInit(&sFix, pParse, iDb, "view", pName)
-    && sqlite3FixSelect(&sFix, pSelect)
-  ){
-    sqlite3SelectDelete(db, pSelect);
-    return;
-  }
+  sqlite3FixInit(&sFix, pParse, iDb, "view", pName);
+  if( sqlite3FixSelect(&sFix, pSelect) ) goto create_view_fail;
 
   /* Make a copy of the entire SELECT statement that defines the view.
   ** This will force all the Expr.token.z values to be dynamically
@@ -81145,30 +99486,31 @@ SQLITE_PRIVATE void sqlite3CreateView(
   ** they will persist after the current sqlite3_exec() call returns.
   */
   p->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
-  sqlite3SelectDelete(db, pSelect);
-  if( db->mallocFailed ){
-    return;
-  }
-  if( !db->init.busy ){
-    sqlite3ViewGetColumnNames(pParse, p);
-  }
+  p->pCheck = sqlite3ExprListDup(db, pCNames, EXPRDUP_REDUCE);
+  if( db->mallocFailed ) goto create_view_fail;
 
   /* Locate the end of the CREATE VIEW statement.  Make sEnd point to
   ** the end.
   */
   sEnd = pParse->sLastToken;
-  if( ALWAYS(sEnd.z[0]!=0) && sEnd.z[0]!=';' ){
+  assert( sEnd.z[0]!=0 );
+  if( sEnd.z[0]!=';' ){
     sEnd.z += sEnd.n;
   }
   sEnd.n = 0;
   n = (int)(sEnd.z - pBegin->z);
+  assert( n>0 );
   z = pBegin->z;
-  while( ALWAYS(n>0) && sqlite3Isspace(z[n-1]) ){ n--; }
+  while( sqlite3Isspace(z[n-1]) ){ n--; }
   sEnd.z = &z[n-1];
   sEnd.n = 1;
 
   /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */
-  sqlite3EndTable(pParse, 0, &sEnd, 0);
+  sqlite3EndTable(pParse, 0, &sEnd, 0, 0);
+
+create_view_fail:
+  sqlite3SelectDelete(db, pSelect);
+  sqlite3ExprListDelete(db, pCNames);
   return;
 }
 #endif /* SQLITE_OMIT_VIEW */
@@ -81185,7 +99527,7 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
   int nErr = 0;     /* Number of errors encountered */
   int n;            /* Temporarily holds the number of cursors assigned */
   sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
-  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+  sqlite3_xauth xAuth;       /* Saved xAuth pointer */
 
   assert( pTable );
 
@@ -81233,11 +99575,10 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
   assert( pTable->pSelect );
   pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
   if( pSel ){
-    u8 enableLookaside = db->lookaside.bEnabled;
     n = pParse->nTab;
     sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
     pTable->nCol = -1;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.bDisable++;
 #ifndef SQLITE_OMIT_AUTHORIZATION
     xAuth = db->xAuth;
     db->xAuth = 0;
@@ -81246,25 +99587,43 @@ SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
 #else
     pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);
 #endif
-    db->lookaside.bEnabled = enableLookaside;
     pParse->nTab = n;
-    if( pSelTab ){
+    if( pTable->pCheck ){
+      /* CREATE VIEW name(arglist) AS ...
+      ** The names of the columns in the table are taken from
+      ** arglist which is stored in pTable->pCheck.  The pCheck field
+      ** normally holds CHECK constraints on an ordinary table, but for
+      ** a VIEW it holds the list of column names.
+      */
+      sqlite3ColumnsFromExprList(pParse, pTable->pCheck, 
+                                 &pTable->nCol, &pTable->aCol);
+      if( db->mallocFailed==0 
+       && pParse->nErr==0
+       && pTable->nCol==pSel->pEList->nExpr
+      ){
+        sqlite3SelectAddColumnTypeAndCollation(pParse, pTable, pSel);
+      }
+    }else if( pSelTab ){
+      /* CREATE VIEW name AS...  without an argument list.  Construct
+      ** the column names from the SELECT statement that defines the view.
+      */
       assert( pTable->aCol==0 );
       pTable->nCol = pSelTab->nCol;
       pTable->aCol = pSelTab->aCol;
       pSelTab->nCol = 0;
       pSelTab->aCol = 0;
-      sqlite3DeleteTable(db, pSelTab);
       assert( sqlite3SchemaMutexHeld(db, 0, pTable->pSchema) );
-      pTable->pSchema->flags |= DB_UnresetViews;
     }else{
       pTable->nCol = 0;
       nErr++;
     }
+    sqlite3DeleteTable(db, pSelTab);
     sqlite3SelectDelete(db, pSel);
+    db->lookaside.bDisable--;
   } else {
     nErr++;
   }
+  pTable->pSchema->schemaFlags |= DB_UnresetViews;
 #endif /* SQLITE_OMIT_VIEW */
   return nErr;  
 }
@@ -81281,7 +99640,7 @@ static void sqliteViewResetAll(sqlite3 *db, int idx){
   for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){
     Table *pTab = sqliteHashData(i);
     if( pTab->pSelect ){
-      sqliteDeleteColumnNames(db, pTab);
+      sqlite3DeleteColumnNames(db, pTab);
       pTab->aCol = 0;
       pTab->nCol = 0;
     }
@@ -81343,6 +99702,7 @@ SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3 *db, int iDb, int iFrom, int iT
 static void destroyRootPage(Parse *pParse, int iTable, int iDb){
   Vdbe *v = sqlite3GetVdbe(pParse);
   int r1 = sqlite3GetTempReg(pParse);
+  assert( iTable>1 );
   sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
   sqlite3MayAbort(pParse);
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -81414,6 +99774,7 @@ static void destroyTable(Parse *pParse, Table *pTab){
       return;
     }else{
       int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+      assert( iDb>=0 && iDb<pParse->db->nDb );
       destroyRootPage(pParse, iLargest, iDb);
       iDestroyed = iLargest;
     }
@@ -81433,7 +99794,7 @@ static void sqlite3ClearStatTables(
 ){
   int i;
   const char *zDbName = pParse->db->aDb[iDb].zName;
-  for(i=1; i<=3; i++){
+  for(i=1; i<=4; i++){
     char zTab[24];
     sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
     if( sqlite3FindTable(pParse->db, zTab, zDbName) ){
@@ -81493,7 +99854,7 @@ SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, in
   /* Drop all SQLITE_MASTER table and index entries that refer to the
   ** table. The program name loops through the master table and deletes
   ** every row that refers to a table of the same name as the one being
-  ** dropped. Triggers are handled seperately because a trigger can be
+  ** dropped. Triggers are handled separately because a trigger can be
   ** created in the temp database that refers to a table in another
   ** database.
   */
@@ -81530,9 +99891,10 @@ SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView,
   }
   assert( pParse->nErr==0 );
   assert( pName->nSrc==1 );
+  if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
   if( noErr ) db->suppressErr++;
-  pTab = sqlite3LocateTable(pParse, isView, 
-                            pName->a[0].zName, pName->a[0].zDatabase);
+  assert( isView==0 || isView==LOCATE_VIEW );
+  pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
   if( noErr ) db->suppressErr--;
 
   if( pTab==0 ){
@@ -81623,8 +99985,8 @@ exit_drop_table:
 ** currently under construction.  pFromCol determines which columns
 ** in the current table point to the foreign key.  If pFromCol==0 then
 ** connect the key to the last column inserted.  pTo is the name of
-** the table referred to.  pToCol is a list of tables in the other
-** pTo table that the foreign key points to.  flags contains all
+** the table referred to (a.k.a the "parent" table).  pToCol is a list
+** of tables in the parent pTo table.  flags contains all
 ** information about the conflict resolution algorithms specified
 ** in the ON DELETE, ON UPDATE and ON INSERT clauses.
 **
@@ -81724,10 +100086,10 @@ SQLITE_PRIVATE void sqlite3CreateForeignKey(
 
   assert( sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
   pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash, 
-      pFKey->zTo, sqlite3Strlen30(pFKey->zTo), (void *)pFKey
+      pFKey->zTo, (void *)pFKey
   );
   if( pNextTo==pFKey ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
     goto fk_end;
   }
   if( pNextTo ){
@@ -81784,12 +100146,10 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   int addr1;                     /* Address of top of loop */
   int addr2;                     /* Address to jump to for next iteration */
   int tnum;                      /* Root page of index */
+  int iPartIdxLabel;             /* Jump to this label to skip a row */
   Vdbe *v;                       /* Generate code into this virtual machine */
   KeyInfo *pKey;                 /* KeyInfo for index */
-#ifdef SQLITE_OMIT_MERGE_SORT
-  int regIdxKey;                 /* Registers containing the index key */
-#endif
-  int regRecord;                 /* Register holding assemblied index record */
+  int regRecord;                 /* Register holding assembled index record */
   sqlite3 *db = pParse->db;      /* The database connection */
   int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
 
@@ -81809,75 +100169,48 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     tnum = memRootPage;
   }else{
     tnum = pIndex->tnum;
-    sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
-  }
-  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
-  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
-                    (char *)pKey, P4_KEYINFO_HANDOFF);
-  if( memRootPage>=0 ){
-    sqlite3VdbeChangeP5(v, 1);
   }
+  pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);
+  assert( pKey!=0 || db->mallocFailed || pParse->nErr );
 
-#ifndef SQLITE_OMIT_MERGE_SORT
   /* Open the sorter cursor if we are to use one. */
   iSorter = pParse->nTab++;
-  sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);
-#else
-  iSorter = iTab;
-#endif
+  sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, pIndex->nKeyCol, (char*)
+                    sqlite3KeyInfoRef(pKey), P4_KEYINFO);
 
   /* Open the table. Loop through all rows of the table, inserting index
   ** records into the sorter. */
   sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
-  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
+  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0); VdbeCoverage(v);
   regRecord = sqlite3GetTempReg(pParse);
 
-#ifndef SQLITE_OMIT_MERGE_SORT
-  sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
+  sqlite3GenerateIndexKey(pParse,pIndex,iTab,regRecord,0,&iPartIdxLabel,0,0);
   sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
-  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
+  sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
+  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1); VdbeCoverage(v);
   sqlite3VdbeJumpHere(v, addr1);
-  addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0);
-  if( pIndex->onError!=OE_None ){
+  if( memRootPage<0 ) sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
+  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
+                    (char *)pKey, P4_KEYINFO);
+  sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));
+
+  addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0); VdbeCoverage(v);
+  if( IsUniqueIndex(pIndex) ){
     int j2 = sqlite3VdbeCurrentAddr(v) + 3;
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
+    sqlite3VdbeGoto(v, j2);
     addr2 = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp3(v, OP_SorterCompare, iSorter, j2, regRecord);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC
-    );
+    sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,
+                         pIndex->nKeyCol); VdbeCoverage(v);
+    sqlite3UniqueConstraint(pParse, OE_Abort, pIndex);
   }else{
     addr2 = sqlite3VdbeCurrentAddr(v);
   }
-  sqlite3VdbeAddOp2(v, OP_SorterData, iSorter, regRecord);
-  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 1);
-  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-#else
-  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
-  addr2 = addr1 + 1;
-  if( pIndex->onError!=OE_None ){
-    const int regRowid = regIdxKey + pIndex->nColumn;
-    const int j2 = sqlite3VdbeCurrentAddr(v) + 2;
-    void * const pRegKey = SQLITE_INT_TO_PTR(regIdxKey);
-
-    /* The registers accessed by the OP_IsUnique opcode were allocated
-    ** using sqlite3GetTempRange() inside of the sqlite3GenerateIndexKey()
-    ** call above. Just before that function was freed they were released
-    ** (made available to the compiler for reuse) using 
-    ** sqlite3ReleaseTempRange(). So in some ways having the OP_IsUnique
-    ** opcode use the values stored within seems dangerous. However, since
-    ** we can be sure that no other temp registers have been allocated
-    ** since sqlite3ReleaseTempRange() was called, it is safe to do so.
-    */
-    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, j2, regRowid, pRegKey, P4_INT32);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
-  }
+  sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);
+  sqlite3VdbeAddOp3(v, OP_Last, iIdx, 0, -1);
   sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 0);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-#endif
   sqlite3ReleaseTempReg(pParse, regRecord);
-  sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2);
+  sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);
   sqlite3VdbeJumpHere(v, addr1);
 
   sqlite3VdbeAddOp1(v, OP_Close, iTab);
@@ -81886,6 +100219,41 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
 }
 
 /*
+** Allocate heap space to hold an Index object with nCol columns.
+**
+** Increase the allocation size to provide an extra nExtra bytes
+** of 8-byte aligned space after the Index object and return a
+** pointer to this extra space in *ppExtra.
+*/
+SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(
+  sqlite3 *db,         /* Database connection */
+  i16 nCol,            /* Total number of columns in the index */
+  int nExtra,          /* Number of bytes of extra space to alloc */
+  char **ppExtra       /* Pointer to the "extra" space */
+){
+  Index *p;            /* Allocated index object */
+  int nByte;           /* Bytes of space for Index object + arrays */
+
+  nByte = ROUND8(sizeof(Index)) +              /* Index structure  */
+          ROUND8(sizeof(char*)*nCol) +         /* Index.azColl     */
+          ROUND8(sizeof(LogEst)*(nCol+1) +     /* Index.aiRowLogEst   */
+                 sizeof(i16)*nCol +            /* Index.aiColumn   */
+                 sizeof(u8)*nCol);             /* Index.aSortOrder */
+  p = sqlite3DbMallocZero(db, nByte + nExtra);
+  if( p ){
+    char *pExtra = ((char*)p)+ROUND8(sizeof(Index));
+    p->azColl = (const char**)pExtra; pExtra += ROUND8(sizeof(char*)*nCol);
+    p->aiRowLogEst = (LogEst*)pExtra; pExtra += sizeof(LogEst)*(nCol+1);
+    p->aiColumn = (i16*)pExtra;       pExtra += sizeof(i16)*nCol;
+    p->aSortOrder = (u8*)pExtra;
+    p->nColumn = nCol;
+    p->nKeyCol = nCol - 1;
+    *ppExtra = ((char*)p) + nByte;
+  }
+  return p;
+}
+
+/*
 ** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
 ** and pTblList is the name of the table that is to be indexed.  Both will 
 ** be NULL for a primary key or an index that is created to satisfy a
@@ -81896,12 +100264,8 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
 ** pList is a list of columns to be indexed.  pList will be NULL if this
 ** is a primary key or unique-constraint on the most recent column added
 ** to the table currently under construction.  
-**
-** If the index is created successfully, return a pointer to the new Index
-** structure. This is used by sqlite3AddPrimaryKey() to mark the index
-** as the tables primary key (Index.autoIndex==2).
 */
-SQLITE_PRIVATE Index *sqlite3CreateIndex(
+SQLITE_PRIVATE void sqlite3CreateIndex(
   Parse *pParse,     /* All information about this parse */
   Token *pName1,     /* First part of index name. May be NULL */
   Token *pName2,     /* Second part of index name. May be NULL */
@@ -81909,17 +100273,16 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   ExprList *pList,   /* A list of columns to be indexed */
   int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
   Token *pStart,     /* The CREATE token that begins this statement */
-  Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
+  Expr *pPIWhere,    /* WHERE clause for partial indices */
   int sortOrder,     /* Sort order of primary key when pList==NULL */
-  int ifNotExist     /* Omit error if index already exists */
+  int ifNotExist,    /* Omit error if index already exists */
+  u8 idxType         /* The index type */
 ){
-  Index *pRet = 0;     /* Pointer to return */
   Table *pTab = 0;     /* Table to be indexed */
   Index *pIndex = 0;   /* The index to be created */
   char *zName = 0;     /* Name of the index */
   int nName;           /* Number of characters in zName */
   int i, j;
-  Token nullId;        /* Fake token for an empty ID list */
   DbFixer sFix;        /* For assigning database names to pTable */
   int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */
   sqlite3 *db = pParse->db;
@@ -81927,13 +100290,15 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   int iDb;             /* Index of the database that is being written */
   Token *pName = 0;    /* Unqualified name of the index to create */
   struct ExprList_item *pListItem; /* For looping over pList */
-  int nCol;
-  int nExtra = 0;
-  char *zExtra;
+  int nExtra = 0;                  /* Space allocated for zExtra[] */
+  int nExtraCol;                   /* Number of extra columns needed */
+  char *zExtra = 0;                /* Extra space after the Index object */
+  Index *pPk = 0;      /* PRIMARY KEY index for WITHOUT ROWID tables */
 
-  assert( pStart==0 || pEnd!=0 ); /* pEnd must be non-NULL if pStart is */
-  assert( pParse->nErr==0 );      /* Never called with prior errors */
-  if( db->mallocFailed || IN_DECLARE_VTAB ){
+  if( db->mallocFailed || pParse->nErr>0 ){
+    goto exit_create_index;
+  }
+  if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){
     goto exit_create_index;
   }
   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
@@ -81955,7 +100320,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     assert( pName && pName->z );
 
 #ifndef SQLITE_OMIT_TEMPDB
-    /* If the index name was unqualified, check if the the table
+    /* If the index name was unqualified, check if the table
     ** is a temp table. If so, set the database to 1. Do not do this
     ** if initialising a database schema.
     */
@@ -81967,17 +100332,22 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     }
 #endif
 
-    if( sqlite3FixInit(&sFix, pParse, iDb, "index", pName) &&
-        sqlite3FixSrcList(&sFix, pTblName)
-    ){
+    sqlite3FixInit(&sFix, pParse, iDb, "index", pName);
+    if( sqlite3FixSrcList(&sFix, pTblName) ){
       /* Because the parser constructs pTblName from a single identifier,
       ** sqlite3FixSrcList can never fail. */
       assert(0);
     }
-    pTab = sqlite3LocateTable(pParse, 0, pTblName->a[0].zName, 
-        pTblName->a[0].zDatabase);
-    if( !pTab || db->mallocFailed ) goto exit_create_index;
-    assert( db->aDb[iDb].pSchema==pTab->pSchema );
+    pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);
+    assert( db->mallocFailed==0 || pTab==0 );
+    if( pTab==0 ) goto exit_create_index;
+    if( iDb==1 && db->aDb[iDb].pSchema!=pTab->pSchema ){
+      sqlite3ErrorMsg(pParse, 
+           "cannot create a TEMP index on non-TEMP table \"%s\"",
+           pTab->zName);
+      goto exit_create_index;
+    }
+    if( !HasRowid(pTab) ) pPk = sqlite3PrimaryKeyIndex(pTab);
   }else{
     assert( pName==0 );
     assert( pStart==0 );
@@ -81990,7 +100360,11 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   assert( pTab!=0 );
   assert( pParse->nErr==0 );
   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
-       && memcmp(&pTab->zName[7],"altertab_",9)!=0 ){
+       && db->init.busy==0
+#if SQLITE_USER_AUTHENTICATION
+       && sqlite3UserAuthTable(pTab->zName)==0
+#endif
+       && sqlite3StrNICmp(&pTab->zName[7],"altertab_",9)!=0 ){
     sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
     goto exit_create_index;
   }
@@ -82050,6 +100424,13 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     if( zName==0 ){
       goto exit_create_index;
     }
+
+    /* Automatic index names generated from within sqlite3_declare_vtab()
+    ** must have names that are distinct from normal automatic index names.
+    ** The following statement converts "sqlite3_autoindex..." into
+    ** "sqlite3_butoindex..." in order to make the names distinct.
+    ** The "vtab_err.test" test demonstrates the need of this statement. */
+    if( IN_DECLARE_VTAB ) zName[7]++;
   }
 
   /* Check for authorization to create an index.
@@ -82073,12 +100454,15 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   ** So create a fake list to simulate this.
   */
   if( pList==0 ){
-    nullId.z = pTab->aCol[pTab->nCol-1].zName;
-    nullId.n = sqlite3Strlen30((char*)nullId.z);
-    pList = sqlite3ExprListAppend(pParse, 0, 0);
+    Token prevCol;
+    sqlite3TokenInit(&prevCol, pTab->aCol[pTab->nCol-1].zName);
+    pList = sqlite3ExprListAppend(pParse, 0,
+              sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
     if( pList==0 ) goto exit_create_index;
-    sqlite3ExprListSetName(pParse, pList, &nullId, 0);
-    pList->a[0].sortOrder = (u8)sortOrder;
+    assert( pList->nExpr==1 );
+    sqlite3ExprListSetSortOrder(pList, sortOrder);
+  }else{
+    sqlite3ExprListCheckLength(pParse, pList, "index");
   }
 
   /* Figure out how many bytes of space are required to store explicitly
@@ -82086,13 +100470,9 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   */
   for(i=0; i<pList->nExpr; i++){
     Expr *pExpr = pList->a[i].pExpr;
-    if( pExpr ){
-      CollSeq *pColl = pExpr->pColl;
-      /* Either pColl!=0 or there was an OOM failure.  But if an OOM
-      ** failure we have quit before reaching this point. */
-      if( ALWAYS(pColl) ){
-        nExtra += (1 + sqlite3Strlen30(pColl->zName));
-      }
+    assert( pExpr!=0 );
+    if( pExpr->op==TK_COLLATE ){
+      nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
     }
   }
 
@@ -82100,31 +100480,28 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   ** Allocate the index structure. 
   */
   nName = sqlite3Strlen30(zName);
-  nCol = pList->nExpr;
-  pIndex = sqlite3DbMallocZero(db, 
-      sizeof(Index) +              /* Index structure  */
-      sizeof(tRowcnt)*(nCol+1) +   /* Index.aiRowEst   */
-      sizeof(int)*nCol +           /* Index.aiColumn   */
-      sizeof(char *)*nCol +        /* Index.azColl     */
-      sizeof(u8)*nCol +            /* Index.aSortOrder */
-      nName + 1 +                  /* Index.zName      */
-      nExtra                       /* Collation sequence names */
-  );
+  nExtraCol = pPk ? pPk->nKeyCol : 1;
+  pIndex = sqlite3AllocateIndexObject(db, pList->nExpr + nExtraCol,
+                                      nName + nExtra + 1, &zExtra);
   if( db->mallocFailed ){
     goto exit_create_index;
   }
-  pIndex->aiRowEst = (tRowcnt*)(&pIndex[1]);
-  pIndex->azColl = (char**)(&pIndex->aiRowEst[nCol+1]);
-  pIndex->aiColumn = (int *)(&pIndex->azColl[nCol]);
-  pIndex->aSortOrder = (u8 *)(&pIndex->aiColumn[nCol]);
-  pIndex->zName = (char *)(&pIndex->aSortOrder[nCol]);
-  zExtra = (char *)(&pIndex->zName[nName+1]);
+  assert( EIGHT_BYTE_ALIGNMENT(pIndex->aiRowLogEst) );
+  assert( EIGHT_BYTE_ALIGNMENT(pIndex->azColl) );
+  pIndex->zName = zExtra;
+  zExtra += nName + 1;
   memcpy(pIndex->zName, zName, nName+1);
   pIndex->pTable = pTab;
-  pIndex->nColumn = pList->nExpr;
   pIndex->onError = (u8)onError;
-  pIndex->autoIndex = (u8)(pName==0);
+  pIndex->uniqNotNull = onError!=OE_None;
+  pIndex->idxType = idxType;
   pIndex->pSchema = db->aDb[iDb].pSchema;
+  pIndex->nKeyCol = pList->nExpr;
+  if( pPIWhere ){
+    sqlite3ResolveSelfReference(pParse, pTab, NC_PartIdx, pPIWhere, 0);
+    pIndex->pPartIdxWhere = pPIWhere;
+    pPIWhere = 0;
+  }
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
 
   /* Check to see if we should honor DESC requests on index columns
@@ -82135,52 +100512,65 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     sortOrderMask = 0;    /* Ignore DESC */
   }
 
-  /* Scan the names of the columns of the table to be indexed and
-  ** load the column indices into the Index structure.  Report an error
-  ** if any column is not found.
+  /* Analyze the list of expressions that form the terms of the index and
+  ** report any errors.  In the common case where the expression is exactly
+  ** a table column, store that column in aiColumn[].  For general expressions,
+  ** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].
   **
-  ** TODO:  Add a test to make sure that the same column is not named
-  ** more than once within the same index.  Only the first instance of
-  ** the column will ever be used by the optimizer.  Note that using the
-  ** same column more than once cannot be an error because that would 
-  ** break backwards compatibility - it needs to be a warning.
+  ** TODO: Issue a warning if two or more columns of the index are identical.
+  ** TODO: Issue a warning if the table primary key is used as part of the
+  ** index key.
   */
   for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
-    const char *zColName = pListItem->zName;
-    Column *pTabCol;
-    int requestedSortOrder;
-    char *zColl;                   /* Collation sequence name */
-
-    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
-      if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
-    }
-    if( j>=pTab->nCol ){
-      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
-        pTab->zName, zColName);
-      pParse->checkSchema = 1;
-      goto exit_create_index;
+    Expr *pCExpr;                  /* The i-th index expression */
+    int requestedSortOrder;        /* ASC or DESC on the i-th expression */
+    const char *zColl;             /* Collation sequence name */
+
+    sqlite3StringToId(pListItem->pExpr);
+    sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);
+    if( pParse->nErr ) goto exit_create_index;
+    pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
+    if( pCExpr->op!=TK_COLUMN ){
+      if( pTab==pParse->pNewTable ){
+        sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "
+                                "UNIQUE constraints");
+        goto exit_create_index;
+      }
+      if( pIndex->aColExpr==0 ){
+        ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
+        pIndex->aColExpr = pCopy;
+        if( !db->mallocFailed ){
+          assert( pCopy!=0 );
+          pListItem = &pCopy->a[i];
+        }
+      }
+      j = XN_EXPR;
+      pIndex->aiColumn[i] = XN_EXPR;
+      pIndex->uniqNotNull = 0;
+    }else{
+      j = pCExpr->iColumn;
+      assert( j<=0x7fff );
+      if( j<0 ){
+        j = pTab->iPKey;
+      }else if( pTab->aCol[j].notNull==0 ){
+        pIndex->uniqNotNull = 0;
+      }
+      pIndex->aiColumn[i] = (i16)j;
     }
-    pIndex->aiColumn[i] = j;
-    /* Justification of the ALWAYS(pListItem->pExpr->pColl):  Because of
-    ** the way the "idxlist" non-terminal is constructed by the parser,
-    ** if pListItem->pExpr is not null then either pListItem->pExpr->pColl
-    ** must exist or else there must have been an OOM error.  But if there
-    ** was an OOM error, we would never reach this point. */
-    if( pListItem->pExpr && ALWAYS(pListItem->pExpr->pColl) ){
+    zColl = 0;
+    if( pListItem->pExpr->op==TK_COLLATE ){
       int nColl;
-      zColl = pListItem->pExpr->pColl->zName;
+      zColl = pListItem->pExpr->u.zToken;
       nColl = sqlite3Strlen30(zColl) + 1;
       assert( nExtra>=nColl );
       memcpy(zExtra, zColl, nColl);
       zColl = zExtra;
       zExtra += nColl;
       nExtra -= nColl;
-    }else{
+    }else if( j>=0 ){
       zColl = pTab->aCol[j].zColl;
-      if( !zColl ){
-        zColl = db->pDfltColl->zName;
-      }
     }
+    if( !zColl ) zColl = sqlite3StrBINARY;
     if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
       goto exit_create_index;
     }
@@ -82188,7 +100578,45 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     requestedSortOrder = pListItem->sortOrder & sortOrderMask;
     pIndex->aSortOrder[i] = (u8)requestedSortOrder;
   }
+
+  /* Append the table key to the end of the index.  For WITHOUT ROWID
+  ** tables (when pPk!=0) this will be the declared PRIMARY KEY.  For
+  ** normal tables (when pPk==0) this will be the rowid.
+  */
+  if( pPk ){
+    for(j=0; j<pPk->nKeyCol; j++){
+      int x = pPk->aiColumn[j];
+      assert( x>=0 );
+      if( hasColumn(pIndex->aiColumn, pIndex->nKeyCol, x) ){
+        pIndex->nColumn--; 
+      }else{
+        pIndex->aiColumn[i] = x;
+        pIndex->azColl[i] = pPk->azColl[j];
+        pIndex->aSortOrder[i] = pPk->aSortOrder[j];
+        i++;
+      }
+    }
+    assert( i==pIndex->nColumn );
+  }else{
+    pIndex->aiColumn[i] = XN_ROWID;
+    pIndex->azColl[i] = sqlite3StrBINARY;
+  }
   sqlite3DefaultRowEst(pIndex);
+  if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);
+
+  /* If this index contains every column of its table, then mark
+  ** it as a covering index */
+  assert( HasRowid(pTab) 
+      || pTab->iPKey<0 || sqlite3ColumnOfIndex(pIndex, pTab->iPKey)>=0 );
+  if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
+    pIndex->isCovering = 1;
+    for(j=0; j<pTab->nCol; j++){
+      if( j==pTab->iPKey ) continue;
+      if( sqlite3ColumnOfIndex(pIndex,j)>=0 ) continue;
+      pIndex->isCovering = 0;
+      break;
+    }
+  }
 
   if( pTab==pParse->pNewTable ){
     /* This routine has been called to create an automatic index as a
@@ -82215,27 +100643,28 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     Index *pIdx;
     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
       int k;
-      assert( pIdx->onError!=OE_None );
-      assert( pIdx->autoIndex );
-      assert( pIndex->onError!=OE_None );
+      assert( IsUniqueIndex(pIdx) );
+      assert( pIdx->idxType!=SQLITE_IDXTYPE_APPDEF );
+      assert( IsUniqueIndex(pIndex) );
 
-      if( pIdx->nColumn!=pIndex->nColumn ) continue;
-      for(k=0; k<pIdx->nColumn; k++){
+      if( pIdx->nKeyCol!=pIndex->nKeyCol ) continue;
+      for(k=0; k<pIdx->nKeyCol; k++){
         const char *z1;
         const char *z2;
+        assert( pIdx->aiColumn[k]>=0 );
         if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
         z1 = pIdx->azColl[k];
         z2 = pIndex->azColl[k];
-        if( z1!=z2 && sqlite3StrICmp(z1, z2) ) break;
+        if( sqlite3StrICmp(z1, z2) ) break;
       }
-      if( k==pIdx->nColumn ){
+      if( k==pIdx->nKeyCol ){
         if( pIdx->onError!=pIndex->onError ){
           /* This constraint creates the same index as a previous
           ** constraint specified somewhere in the CREATE TABLE statement.
           ** However the ON CONFLICT clauses are different. If both this 
           ** constraint and the previous equivalent constraint have explicit
           ** ON CONFLICT clauses this is an error. Otherwise, use the
-          ** explicitly specified behaviour for the index.
+          ** explicitly specified behavior for the index.
           */
           if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
             sqlite3ErrorMsg(pParse, 
@@ -82245,6 +100674,7 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
             pIdx->onError = pIndex->onError;
           }
         }
+        if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;
         goto exit_create_index;
       }
     }
@@ -82253,15 +100683,16 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
   /* Link the new Index structure to its table and to the other
   ** in-memory database structures. 
   */
+  assert( pParse->nErr==0 );
   if( db->init.busy ){
     Index *p;
+    assert( !IN_DECLARE_VTAB );
     assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
     p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
-                          pIndex->zName, sqlite3Strlen30(pIndex->zName),
-                          pIndex);
+                          pIndex->zName, pIndex);
     if( p ){
       assert( p==pIndex );  /* Malloc must have failed */
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       goto exit_create_index;
     }
     db->flags |= SQLITE_InternChanges;
@@ -82270,22 +100701,20 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     }
   }
 
-  /* If the db->init.busy is 0 then create the index on disk.  This
-  ** involves writing the index into the master table and filling in the
-  ** index with the current table contents.
-  **
-  ** The db->init.busy is 0 when the user first enters a CREATE INDEX 
-  ** command.  db->init.busy is 1 when a database is opened and 
-  ** CREATE INDEX statements are read out of the master table.  In
-  ** the latter case the index already exists on disk, which is why
-  ** we don't want to recreate it.
+  /* If this is the initial CREATE INDEX statement (or CREATE TABLE if the
+  ** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then
+  ** emit code to allocate the index rootpage on disk and make an entry for
+  ** the index in the sqlite_master table and populate the index with
+  ** content.  But, do not do this if we are simply reading the sqlite_master
+  ** table to parse the schema, or if this index is the PRIMARY KEY index
+  ** of a WITHOUT ROWID table.
   **
-  ** If pTblName==0 it means this index is generated as a primary key
-  ** or UNIQUE constraint of a CREATE TABLE statement.  Since the table
+  ** If pTblName==0 it means this index is generated as an implied PRIMARY KEY
+  ** or UNIQUE index in a CREATE TABLE statement.  Since the table
   ** has just been created, it contains no data and the index initialization
   ** step can be skipped.
   */
-  else{ /* if( db->init.busy==0 ) */
+  else if( HasRowid(pTab) || pTblName!=0 ){
     Vdbe *v;
     char *zStmt;
     int iMem = ++pParse->nMem;
@@ -82293,22 +100722,26 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
     v = sqlite3GetVdbe(pParse);
     if( v==0 ) goto exit_create_index;
 
-
-    /* Create the rootpage for the index
-    */
     sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+    /* Create the rootpage for the index using CreateIndex. But before
+    ** doing so, code a Noop instruction and store its address in 
+    ** Index.tnum. This is required in case this index is actually a 
+    ** PRIMARY KEY and the table is actually a WITHOUT ROWID table. In 
+    ** that case the convertToWithoutRowidTable() routine will replace
+    ** the Noop with a Goto to jump over the VDBE code generated below. */
+    pIndex->tnum = sqlite3VdbeAddOp0(v, OP_Noop);
     sqlite3VdbeAddOp2(v, OP_CreateIndex, iDb, iMem);
 
     /* Gather the complete text of the CREATE INDEX statement into
     ** the zStmt variable
     */
     if( pStart ){
-      assert( pEnd!=0 );
+      int n = (int)(pParse->sLastToken.z - pName->z) + pParse->sLastToken.n;
+      if( pName->z[n-1]==';' ) n--;
       /* A named index with an explicit CREATE INDEX statement */
       zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
-        onError==OE_None ? "" : " UNIQUE",
-        (int)(pEnd->z - pName->z) + 1,
-        pName->z);
+        onError==OE_None ? "" : " UNIQUE", n, pName->z);
     }else{
       /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
       /* zStmt = sqlite3MPrintf(""); */
@@ -82335,8 +100768,10 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       sqlite3ChangeCookie(pParse, iDb);
       sqlite3VdbeAddParseSchemaOp(v, iDb,
          sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
-      sqlite3VdbeAddOp1(v, OP_Expire, 0);
+      sqlite3VdbeAddOp0(v, OP_Expire);
     }
+
+    sqlite3VdbeJumpHere(v, pIndex->tnum);
   }
 
   /* When adding an index to the list of indices for a table, make
@@ -82358,31 +100793,27 @@ SQLITE_PRIVATE Index *sqlite3CreateIndex(
       pIndex->pNext = pOther->pNext;
       pOther->pNext = pIndex;
     }
-    pRet = pIndex;
     pIndex = 0;
   }
 
   /* Clean up before exiting */
 exit_create_index:
-  if( pIndex ){
-    sqlite3DbFree(db, pIndex->zColAff);
-    sqlite3DbFree(db, pIndex);
-  }
+  if( pIndex ) freeIndex(db, pIndex);
+  sqlite3ExprDelete(db, pPIWhere);
   sqlite3ExprListDelete(db, pList);
   sqlite3SrcListDelete(db, pTblName);
   sqlite3DbFree(db, zName);
-  return pRet;
 }
 
 /*
 ** Fill the Index.aiRowEst[] array with default information - information
 ** to be used when we have not run the ANALYZE command.
 **
-** aiRowEst[0] is suppose to contain the number of elements in the index.
+** aiRowEst[0] is supposed to contain the number of elements in the index.
 ** Since we do not know, guess 1 million.  aiRowEst[1] is an estimate of the
 ** number of rows in the table that match any particular value of the
 ** first column of the index.  aiRowEst[2] is an estimate of the number
-** of rows that match any particular combiniation of the first 2 columns
+** of rows that match any particular combination of the first 2 columns
 ** of the index.  And so forth.  It must always be the case that
 *
 **           aiRowEst[N]<=aiRowEst[N-1]
@@ -82393,20 +100824,28 @@ exit_create_index:
 ** are based on typical values found in actual indices.
 */
 SQLITE_PRIVATE void sqlite3DefaultRowEst(Index *pIdx){
-  tRowcnt *a = pIdx->aiRowEst;
+  /*                10,  9,  8,  7,  6 */
+  LogEst aVal[] = { 33, 32, 30, 28, 26 };
+  LogEst *a = pIdx->aiRowLogEst;
+  int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);
   int i;
-  tRowcnt n;
-  assert( a!=0 );
-  a[0] = pIdx->pTable->nRowEst;
-  if( a[0]<10 ) a[0] = 10;
-  n = 10;
-  for(i=1; i<=pIdx->nColumn; i++){
-    a[i] = n;
-    if( n>5 ) n--;
-  }
-  if( pIdx->onError!=OE_None ){
-    a[pIdx->nColumn] = 1;
+
+  /* Set the first entry (number of rows in the index) to the estimated 
+  ** number of rows in the table, or half the number of rows in the table
+  ** for a partial index.   But do not let the estimate drop below 10. */
+  a[0] = pIdx->pTable->nRowLogEst;
+  if( pIdx->pPartIdxWhere!=0 ) a[0] -= 10;  assert( 10==sqlite3LogEst(2) );
+  if( a[0]<33 ) a[0] = 33;                  assert( 33==sqlite3LogEst(10) );
+
+  /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is
+  ** 6 and each subsequent value (if any) is 5.  */
+  memcpy(&a[1], aVal, nCopy*sizeof(LogEst));
+  for(i=nCopy+1; i<=pIdx->nKeyCol; i++){
+    a[i] = 23;                    assert( 23==sqlite3LogEst(5) );
   }
+
+  assert( 0==sqlite3LogEst(1) );
+  if( IsUniqueIndex(pIdx) ) a[pIdx->nKeyCol] = 0;
 }
 
 /*
@@ -82437,7 +100876,7 @@ SQLITE_PRIVATE void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists
     pParse->checkSchema = 1;
     goto exit_drop_index;
   }
-  if( pIndex->autoIndex ){
+  if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){
     sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
       "or PRIMARY KEY constraint cannot be dropped", 0);
     goto exit_drop_index;
@@ -82478,45 +100917,43 @@ exit_drop_index:
 }
 
 /*
-** pArray is a pointer to an array of objects.  Each object in the
-** array is szEntry bytes in size.  This routine allocates a new
-** object on the end of the array.
+** pArray is a pointer to an array of objects. Each object in the
+** array is szEntry bytes in size. This routine uses sqlite3DbRealloc()
+** to extend the array so that there is space for a new object at the end.
 **
-** *pnEntry is the number of entries already in use.  *pnAlloc is
-** the previously allocated size of the array.  initSize is the
-** suggested initial array size allocation.
+** When this function is called, *pnEntry contains the current size of
+** the array (in entries - so the allocation is ((*pnEntry) * szEntry) bytes
+** in total).
 **
-** The index of the new entry is returned in *pIdx.
+** If the realloc() is successful (i.e. if no OOM condition occurs), the
+** space allocated for the new object is zeroed, *pnEntry updated to
+** reflect the new size of the array and a pointer to the new allocation
+** returned. *pIdx is set to the index of the new array entry in this case.
 **
-** This routine returns a pointer to the array of objects.  This
-** might be the same as the pArray parameter or it might be a different
-** pointer if the array was resized.
+** Otherwise, if the realloc() fails, *pIdx is set to -1, *pnEntry remains
+** unchanged and a copy of pArray returned.
 */
 SQLITE_PRIVATE void *sqlite3ArrayAllocate(
   sqlite3 *db,      /* Connection to notify of malloc failures */
   void *pArray,     /* Array of objects.  Might be reallocated */
   int szEntry,      /* Size of each object in the array */
-  int initSize,     /* Suggested initial allocation, in elements */
   int *pnEntry,     /* Number of objects currently in use */
-  int *pnAlloc,     /* Current size of the allocation, in elements */
   int *pIdx         /* Write the index of a new slot here */
 ){
   char *z;
-  if( *pnEntry >= *pnAlloc ){
-    void *pNew;
-    int newSize;
-    newSize = (*pnAlloc)*2 + initSize;
-    pNew = sqlite3DbRealloc(db, pArray, newSize*szEntry);
+  int n = *pnEntry;
+  if( (n & (n-1))==0 ){
+    int sz = (n==0) ? 1 : 2*n;
+    void *pNew = sqlite3DbRealloc(db, pArray, sz*szEntry);
     if( pNew==0 ){
       *pIdx = -1;
       return pArray;
     }
-    *pnAlloc = sqlite3DbMallocSize(db, pNew)/szEntry;
     pArray = pNew;
   }
   z = (char*)pArray;
-  memset(&z[*pnEntry * szEntry], 0, szEntry);
-  *pIdx = *pnEntry;
+  memset(&z[n * szEntry], 0, szEntry);
+  *pIdx = n;
   ++*pnEntry;
   return pArray;
 }
@@ -82532,15 +100969,12 @@ SQLITE_PRIVATE IdList *sqlite3IdListAppend(sqlite3 *db, IdList *pList, Token *pT
   if( pList==0 ){
     pList = sqlite3DbMallocZero(db, sizeof(IdList) );
     if( pList==0 ) return 0;
-    pList->nAlloc = 0;
   }
   pList->a = sqlite3ArrayAllocate(
       db,
       pList->a,
       sizeof(pList->a[0]),
-      5,
       &pList->nId,
-      &pList->nAlloc,
       &i
   );
   if( i<0 ){
@@ -82611,7 +101045,7 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(
   assert( iStart<=pSrc->nSrc );
 
   /* Allocate additional space if needed */
-  if( pSrc->nSrc+nExtra>pSrc->nAlloc ){
+  if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){
     SrcList *pNew;
     int nAlloc = pSrc->nSrc+nExtra;
     int nGot;
@@ -82623,7 +101057,7 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(
     }
     pSrc = pNew;
     nGot = (sqlite3DbMallocSize(db, pNew) - sizeof(*pSrc))/sizeof(pSrc->a[0])+1;
-    pSrc->nAlloc = (u16)nGot;
+    pSrc->nAlloc = nGot;
   }
 
   /* Move existing slots that come after the newly inserted slots
@@ -82631,7 +101065,7 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(
   for(i=pSrc->nSrc-1; i>=iStart; i--){
     pSrc->a[i+nExtra] = pSrc->a[i];
   }
-  pSrc->nSrc += (i16)nExtra;
+  pSrc->nSrc += nExtra;
 
   /* Zero the newly allocated slots */
   memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);
@@ -82686,10 +101120,12 @@ SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(
 ){
   struct SrcList_item *pItem;
   assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */
+  assert( db!=0 );
   if( pList==0 ){
-    pList = sqlite3DbMallocZero(db, sizeof(SrcList) );
+    pList = sqlite3DbMallocRawNN(db, sizeof(SrcList) );
     if( pList==0 ) return 0;
     pList->nAlloc = 1;
+    pList->nSrc = 0;
   }
   pList = sqlite3SrcListEnlarge(db, pList, 1, pList->nSrc);
   if( db->mallocFailed ){
@@ -82739,7 +101175,8 @@ SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
     sqlite3DbFree(db, pItem->zDatabase);
     sqlite3DbFree(db, pItem->zName);
     sqlite3DbFree(db, pItem->zAlias);
-    sqlite3DbFree(db, pItem->zIndex);
+    if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
+    if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
     sqlite3DeleteTable(db, pItem->pTab);
     sqlite3SelectDelete(db, pItem->pSelect);
     sqlite3ExprDelete(db, pItem->pOn);
@@ -82755,7 +101192,7 @@ SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
 ** if this is the first term of the FROM clause.  pTable and pDatabase
 ** are the name of the table and database named in the FROM clause term.
 ** pDatabase is NULL if the database name qualifier is missing - the
-** usual case.  If the term has a alias, then pAlias points to the
+** usual case.  If the term has an alias, then pAlias points to the
 ** alias token.  If the term is a subquery, then pSubquery is the
 ** SELECT statement that the subquery encodes.  The pTable and
 ** pDatabase parameters are NULL for subqueries.  The pOn and pUsing
@@ -82812,18 +101249,38 @@ SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pI
   assert( pIndexedBy!=0 );
   if( p && ALWAYS(p->nSrc>0) ){
     struct SrcList_item *pItem = &p->a[p->nSrc-1];
-    assert( pItem->notIndexed==0 && pItem->zIndex==0 );
+    assert( pItem->fg.notIndexed==0 );
+    assert( pItem->fg.isIndexedBy==0 );
+    assert( pItem->fg.isTabFunc==0 );
     if( pIndexedBy->n==1 && !pIndexedBy->z ){
       /* A "NOT INDEXED" clause was supplied. See parse.y 
       ** construct "indexed_opt" for details. */
-      pItem->notIndexed = 1;
+      pItem->fg.notIndexed = 1;
     }else{
-      pItem->zIndex = sqlite3NameFromToken(pParse->db, pIndexedBy);
+      pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
+      pItem->fg.isIndexedBy = (pItem->u1.zIndexedBy!=0);
     }
   }
 }
 
 /*
+** Add the list of function arguments to the SrcList entry for a
+** table-valued-function.
+*/
+SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){
+  if( p ){
+    struct SrcList_item *pItem = &p->a[p->nSrc-1];
+    assert( pItem->fg.notIndexed==0 );
+    assert( pItem->fg.isIndexedBy==0 );
+    assert( pItem->fg.isTabFunc==0 );
+    pItem->u1.pFuncArg = pList;
+    pItem->fg.isTabFunc = 1;
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  }
+}
+
+/*
 ** When building up a FROM clause in the parser, the join operator
 ** is initially attached to the left operand.  But the code generator
 ** expects the join operator to be on the right operand.  This routine
@@ -82841,16 +101298,15 @@ SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pI
 SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList *p){
   if( p ){
     int i;
-    assert( p->a || p->nSrc==0 );
     for(i=p->nSrc-1; i>0; i--){
-      p->a[i].jointype = p->a[i-1].jointype;
+      p->a[i].fg.jointype = p->a[i-1].fg.jointype;
     }
-    p->a[0].jointype = 0;
+    p->a[0].fg.jointype = 0;
   }
 }
 
 /*
-** Begin a transaction
+** Generate VDBE code for a BEGIN statement.
 */
 SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
   sqlite3 *db;
@@ -82860,7 +101316,6 @@ SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
   assert( pParse!=0 );
   db = pParse->db;
   assert( db!=0 );
-/*  if( db->aDb[0].pBt==0 ) return; */
   if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){
     return;
   }
@@ -82872,11 +101327,11 @@ SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
       sqlite3VdbeUsesBtree(v, i);
     }
   }
-  sqlite3VdbeAddOp2(v, OP_AutoCommit, 0, 0);
+  sqlite3VdbeAddOp0(v, OP_AutoCommit);
 }
 
 /*
-** Commit a transaction
+** Generate VDBE code for a COMMIT statement.
 */
 SQLITE_PRIVATE void sqlite3CommitTransaction(Parse *pParse){
   Vdbe *v;
@@ -82888,12 +101343,12 @@ SQLITE_PRIVATE void sqlite3CommitTransaction(Parse *pParse){
   }
   v = sqlite3GetVdbe(pParse);
   if( v ){
-    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 0);
+    sqlite3VdbeAddOp1(v, OP_AutoCommit, 1);
   }
 }
 
 /*
-** Rollback a transaction
+** Generate VDBE code for a ROLLBACK statement.
 */
 SQLITE_PRIVATE void sqlite3RollbackTransaction(Parse *pParse){
   Vdbe *v;
@@ -82955,7 +101410,7 @@ SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){
     db->aDb[1].pBt = pBt;
     assert( db->aDb[1].pSchema );
     if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return 1;
     }
   }
@@ -82963,50 +101418,24 @@ SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){
 }
 
 /*
-** Generate VDBE code that will verify the schema cookie and start
-** a read-transaction for all named database files.
-**
-** It is important that all schema cookies be verified and all
-** read transactions be started before anything else happens in
-** the VDBE program.  But this routine can be called after much other
-** code has been generated.  So here is what we do:
-**
-** The first time this routine is called, we code an OP_Goto that
-** will jump to a subroutine at the end of the program.  Then we
-** record every database that needs its schema verified in the
-** pParse->cookieMask field.  Later, after all other code has been
-** generated, the subroutine that does the cookie verifications and
-** starts the transactions will be coded and the OP_Goto P2 value
-** will be made to point to that subroutine.  The generation of the
-** cookie verification subroutine code happens in sqlite3FinishCoding().
-**
-** If iDb<0 then code the OP_Goto only - don't set flag to verify the
-** schema on any databases.  This can be used to position the OP_Goto
-** early in the code, before we know if any database tables will be used.
+** Record the fact that the schema cookie will need to be verified
+** for database iDb.  The code to actually verify the schema cookie
+** will occur at the end of the top-level VDBE and will be generated
+** later, by sqlite3FinishCoding().
 */
 SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
   Parse *pToplevel = sqlite3ParseToplevel(pParse);
+  sqlite3 *db = pToplevel->db;
 
-  if( pToplevel->cookieGoto==0 ){
-    Vdbe *v = sqlite3GetVdbe(pToplevel);
-    if( v==0 ) return;  /* This only happens if there was a prior error */
-    pToplevel->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
-  }
-  if( iDb>=0 ){
-    sqlite3 *db = pToplevel->db;
-    yDbMask mask;
-
-    assert( iDb<db->nDb );
-    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
-    assert( iDb<SQLITE_MAX_ATTACHED+2 );
-    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-    mask = ((yDbMask)1)<<iDb;
-    if( (pToplevel->cookieMask & mask)==0 ){
-      pToplevel->cookieMask |= mask;
-      pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
-      if( !OMIT_TEMPDB && iDb==1 ){
-        sqlite3OpenTempDatabase(pToplevel);
-      }
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pBt!=0 || iDb==1 );
+  assert( iDb<SQLITE_MAX_ATTACHED+2 );
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){
+    DbMaskSet(pToplevel->cookieMask, iDb);
+    pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
+    if( !OMIT_TEMPDB && iDb==1 ){
+      sqlite3OpenTempDatabase(pToplevel);
     }
   }
 }
@@ -83042,7 +101471,7 @@ SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb)
 SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
   Parse *pToplevel = sqlite3ParseToplevel(pParse);
   sqlite3CodeVerifySchema(pParse, iDb);
-  pToplevel->writeMask |= ((yDbMask)1)<<iDb;
+  DbMaskSet(pToplevel->writeMask, iDb);
   pToplevel->isMultiWrite |= setStatement;
 }
 
@@ -83084,12 +101513,76 @@ SQLITE_PRIVATE void sqlite3MayAbort(Parse *pParse){
 ** error. The onError parameter determines which (if any) of the statement
 ** and/or current transaction is rolled back.
 */
-SQLITE_PRIVATE void sqlite3HaltConstraint(Parse *pParse, int onError, char *p4, int p4type){
+SQLITE_PRIVATE void sqlite3HaltConstraint(
+  Parse *pParse,    /* Parsing context */
+  int errCode,      /* extended error code */
+  int onError,      /* Constraint type */
+  char *p4,         /* Error message */
+  i8 p4type,        /* P4_STATIC or P4_TRANSIENT */
+  u8 p5Errmsg       /* P5_ErrMsg type */
+){
   Vdbe *v = sqlite3GetVdbe(pParse);
+  assert( (errCode&0xff)==SQLITE_CONSTRAINT );
   if( onError==OE_Abort ){
     sqlite3MayAbort(pParse);
   }
-  sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0, p4, p4type);
+  sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
+  sqlite3VdbeChangeP5(v, p5Errmsg);
+}
+
+/*
+** Code an OP_Halt due to UNIQUE or PRIMARY KEY constraint violation.
+*/
+SQLITE_PRIVATE void sqlite3UniqueConstraint(
+  Parse *pParse,    /* Parsing context */
+  int onError,      /* Constraint type */
+  Index *pIdx       /* The index that triggers the constraint */
+){
+  char *zErr;
+  int j;
+  StrAccum errMsg;
+  Table *pTab = pIdx->pTable;
+
+  sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 200);
+  if( pIdx->aColExpr ){
+    sqlite3XPrintf(&errMsg, "index '%q'", pIdx->zName);
+  }else{
+    for(j=0; j<pIdx->nKeyCol; j++){
+      char *zCol;
+      assert( pIdx->aiColumn[j]>=0 );
+      zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
+      if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
+      sqlite3XPrintf(&errMsg, "%s.%s", pTab->zName, zCol);
+    }
+  }
+  zErr = sqlite3StrAccumFinish(&errMsg);
+  sqlite3HaltConstraint(pParse, 
+    IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY 
+                            : SQLITE_CONSTRAINT_UNIQUE,
+    onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);
+}
+
+
+/*
+** Code an OP_Halt due to non-unique rowid.
+*/
+SQLITE_PRIVATE void sqlite3RowidConstraint(
+  Parse *pParse,    /* Parsing context */
+  int onError,      /* Conflict resolution algorithm */
+  Table *pTab       /* The table with the non-unique rowid */ 
+){
+  char *zMsg;
+  int rc;
+  if( pTab->iPKey>=0 ){
+    zMsg = sqlite3MPrintf(pParse->db, "%s.%s", pTab->zName,
+                          pTab->aCol[pTab->iPKey].zName);
+    rc = SQLITE_CONSTRAINT_PRIMARYKEY;
+  }else{
+    zMsg = sqlite3MPrintf(pParse->db, "%s.rowid", pTab->zName);
+    rc = SQLITE_CONSTRAINT_ROWID;
+  }
+  sqlite3HaltConstraint(pParse, rc, onError, zMsg, P4_DYNAMIC,
+                        P5_ConstraintUnique);
 }
 
 /*
@@ -83102,8 +101595,8 @@ static int collationMatch(const char *zColl, Index *pIndex){
   assert( zColl!=0 );
   for(i=0; i<pIndex->nColumn; i++){
     const char *z = pIndex->azColl[i];
-    assert( z!=0 );
-    if( 0==sqlite3StrICmp(z, zColl) ){
+    assert( z!=0 || pIndex->aiColumn[i]<0 );
+    if( pIndex->aiColumn[i]>=0 && 0==sqlite3StrICmp(z, zColl) ){
       return 1;
     }
   }
@@ -83222,41 +101715,106 @@ SQLITE_PRIVATE void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
 #endif
 
 /*
-** Return a dynamicly allocated KeyInfo structure that can be used
-** with OP_OpenRead or OP_OpenWrite to access database index pIdx.
+** Return a KeyInfo structure that is appropriate for the given Index.
 **
-** If successful, a pointer to the new structure is returned. In this case
-** the caller is responsible for calling sqlite3DbFree(db, ) on the returned 
-** pointer. If an error occurs (out of memory or missing collation 
-** sequence), NULL is returned and the state of pParse updated to reflect
-** the error.
+** The caller should invoke sqlite3KeyInfoUnref() on the returned object
+** when it has finished using it.
 */
-SQLITE_PRIVATE KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
   int i;
   int nCol = pIdx->nColumn;
-  int nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
-  sqlite3 *db = pParse->db;
-  KeyInfo *pKey = (KeyInfo *)sqlite3DbMallocZero(db, nBytes);
-
+  int nKey = pIdx->nKeyCol;
+  KeyInfo *pKey;
+  if( pParse->nErr ) return 0;
+  if( pIdx->uniqNotNull ){
+    pKey = sqlite3KeyInfoAlloc(pParse->db, nKey, nCol-nKey);
+  }else{
+    pKey = sqlite3KeyInfoAlloc(pParse->db, nCol, 0);
+  }
   if( pKey ){
-    pKey->db = pParse->db;
-    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
-    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );
+    assert( sqlite3KeyInfoIsWriteable(pKey) );
     for(i=0; i<nCol; i++){
-      char *zColl = pIdx->azColl[i];
-      assert( zColl );
-      pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl);
+      const char *zColl = pIdx->azColl[i];
+      pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
+                        sqlite3LocateCollSeq(pParse, zColl);
       pKey->aSortOrder[i] = pIdx->aSortOrder[i];
     }
-    pKey->nField = (u16)nCol;
+    if( pParse->nErr ){
+      sqlite3KeyInfoUnref(pKey);
+      pKey = 0;
+    }
   }
+  return pKey;
+}
 
-  if( pParse->nErr ){
-    sqlite3DbFree(db, pKey);
-    pKey = 0;
+#ifndef SQLITE_OMIT_CTE
+/* 
+** This routine is invoked once per CTE by the parser while parsing a 
+** WITH clause. 
+*/
+SQLITE_PRIVATE With *sqlite3WithAdd(
+  Parse *pParse,          /* Parsing context */
+  With *pWith,            /* Existing WITH clause, or NULL */
+  Token *pName,           /* Name of the common-table */
+  ExprList *pArglist,     /* Optional column name list for the table */
+  Select *pQuery          /* Query used to initialize the table */
+){
+  sqlite3 *db = pParse->db;
+  With *pNew;
+  char *zName;
+
+  /* Check that the CTE name is unique within this WITH clause. If
+  ** not, store an error in the Parse structure. */
+  zName = sqlite3NameFromToken(pParse->db, pName);
+  if( zName && pWith ){
+    int i;
+    for(i=0; i<pWith->nCte; i++){
+      if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){
+        sqlite3ErrorMsg(pParse, "duplicate WITH table name: %s", zName);
+      }
+    }
+  }
+
+  if( pWith ){
+    int nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);
+    pNew = sqlite3DbRealloc(db, pWith, nByte);
+  }else{
+    pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
+  }
+  assert( (pNew!=0 && zName!=0) || db->mallocFailed );
+
+  if( db->mallocFailed ){
+    sqlite3ExprListDelete(db, pArglist);
+    sqlite3SelectDelete(db, pQuery);
+    sqlite3DbFree(db, zName);
+    pNew = pWith;
+  }else{
+    pNew->a[pNew->nCte].pSelect = pQuery;
+    pNew->a[pNew->nCte].pCols = pArglist;
+    pNew->a[pNew->nCte].zName = zName;
+    pNew->a[pNew->nCte].zCteErr = 0;
+    pNew->nCte++;
+  }
+
+  return pNew;
+}
+
+/*
+** Free the contents of the With object passed as the second argument.
+*/
+SQLITE_PRIVATE void sqlite3WithDelete(sqlite3 *db, With *pWith){
+  if( pWith ){
+    int i;
+    for(i=0; i<pWith->nCte; i++){
+      struct Cte *pCte = &pWith->a[i];
+      sqlite3ExprListDelete(db, pCte->pCols);
+      sqlite3SelectDelete(db, pCte->pSelect);
+      sqlite3DbFree(db, pCte->zName);
+    }
+    sqlite3DbFree(db, pWith);
   }
-  return pKey;
 }
+#endif /* !defined(SQLITE_OMIT_CTE) */
 
 /************** End of build.c ***********************************************/
 /************** Begin file callback.c ****************************************/
@@ -83276,6 +101834,7 @@ SQLITE_PRIVATE KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
 ** of user defined functions and collation sequences.
 */
 
+/* #include "sqliteInt.h" */
 
 /*
 ** Invoke the 'collation needed' callback to request a collation sequence
@@ -83336,17 +101895,18 @@ static int synthCollSeq(sqlite3 *db, CollSeq *pColl){
 **
 ** The return value is either the collation sequence to be used in database
 ** db for collation type name zName, length nName, or NULL, if no collation
-** sequence can be found.
+** sequence can be found.  If no collation is found, leave an error message.
 **
 ** See also: sqlite3LocateCollSeq(), sqlite3FindCollSeq()
 */
 SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(
-  sqlite3* db,          /* The database connection */
+  Parse *pParse,        /* Parsing context */
   u8 enc,               /* The desired encoding for the collating sequence */
   CollSeq *pColl,       /* Collating sequence with native encoding, or NULL */
   const char *zName     /* Collating sequence name */
 ){
   CollSeq *p;
+  sqlite3 *db = pParse->db;
 
   p = pColl;
   if( !p ){
@@ -83363,6 +101923,9 @@ SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(
     p = 0;
   }
   assert( !p || p->xCmp );
+  if( p==0 ){
+    sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
+  }
   return p;
 }
 
@@ -83381,10 +101944,8 @@ SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
   if( pColl ){
     const char *zName = pColl->zName;
     sqlite3 *db = pParse->db;
-    CollSeq *p = sqlite3GetCollSeq(db, ENC(db), pColl, zName);
+    CollSeq *p = sqlite3GetCollSeq(pParse, ENC(db), pColl, zName);
     if( !p ){
-      sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
-      pParse->nErr++;
       return SQLITE_ERROR;
     }
     assert( p==pColl );
@@ -83401,7 +101962,7 @@ SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
 **
 ** Each pointer stored in the sqlite3.aCollSeq hash table contains an
 ** array of three CollSeq structures. The first is the collation sequence
-** prefferred for UTF-8, the second UTF-16le, and the third UTF-16be.
+** preferred for UTF-8, the second UTF-16le, and the third UTF-16be.
 **
 ** Stored immediately after the three collation sequences is a copy of
 ** the collation sequence name. A pointer to this string is stored in
@@ -83413,11 +101974,11 @@ static CollSeq *findCollSeqEntry(
   int create            /* Create a new entry if true */
 ){
   CollSeq *pColl;
-  int nName = sqlite3Strlen30(zName);
-  pColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
+  pColl = sqlite3HashFind(&db->aCollSeq, zName);
 
   if( 0==pColl && create ){
-    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1 );
+    int nName = sqlite3Strlen30(zName);
+    pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName + 1);
     if( pColl ){
       CollSeq *pDel = 0;
       pColl[0].zName = (char*)&pColl[3];
@@ -83428,7 +101989,7 @@ static CollSeq *findCollSeqEntry(
       pColl[2].enc = SQLITE_UTF16BE;
       memcpy(pColl[0].zName, zName, nName);
       pColl[0].zName[nName] = 0;
-      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);
+      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, pColl);
 
       /* If a malloc() failure occurred in sqlite3HashInsert(), it will 
       ** return the pColl pointer to be deleted (because it wasn't added
@@ -83436,7 +101997,7 @@ static CollSeq *findCollSeqEntry(
       */
       assert( pDel==0 || pDel==pColl );
       if( pDel!=0 ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
         sqlite3DbFree(db, pDel);
         pColl = 0;
       }
@@ -83484,38 +102045,57 @@ SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(
 ** that uses encoding enc. The value returned indicates how well the
 ** request is matched. A higher value indicates a better match.
 **
+** If nArg is -1 that means to only return a match (non-zero) if p->nArg
+** is also -1.  In other words, we are searching for a function that
+** takes a variable number of arguments.
+**
+** If nArg is -2 that means that we are searching for any function 
+** regardless of the number of arguments it uses, so return a positive
+** match score for any
+**
 ** The returned value is always between 0 and 6, as follows:
 **
-** 0: Not a match, or if nArg<0 and the function is has no implementation.
-** 1: A variable arguments function that prefers UTF-8 when a UTF-16
-**    encoding is requested, or vice versa.
-** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
-**    requested, or vice versa.
-** 3: A variable arguments function using the same text encoding.
-** 4: A function with the exact number of arguments requested that
-**    prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
-** 5: A function with the exact number of arguments requested that
-**    prefers UTF-16LE when UTF-16BE is requested, or vice versa.
-** 6: An exact match.
-**
-*/
-static int matchQuality(FuncDef *p, int nArg, u8 enc){
-  int match = 0;
-  if( p->nArg==-1 || p->nArg==nArg 
-   || (nArg==-1 && (p->xFunc!=0 || p->xStep!=0))
-  ){
+** 0: Not a match.
+** 1: UTF8/16 conversion required and function takes any number of arguments.
+** 2: UTF16 byte order change required and function takes any number of args.
+** 3: encoding matches and function takes any number of arguments
+** 4: UTF8/16 conversion required - argument count matches exactly
+** 5: UTF16 byte order conversion required - argument count matches exactly
+** 6: Perfect match:  encoding and argument count match exactly.
+**
+** If nArg==(-2) then any function with a non-null xSFunc is
+** a perfect match and any function with xSFunc NULL is
+** a non-match.
+*/
+#define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */
+static int matchQuality(
+  FuncDef *p,     /* The function we are evaluating for match quality */
+  int nArg,       /* Desired number of arguments.  (-1)==any */
+  u8 enc          /* Desired text encoding */
+){
+  int match;
+
+  /* nArg of -2 is a special case */
+  if( nArg==(-2) ) return (p->xSFunc==0) ? 0 : FUNC_PERFECT_MATCH;
+
+  /* Wrong number of arguments means "no match" */
+  if( p->nArg!=nArg && p->nArg>=0 ) return 0;
+
+  /* Give a better score to a function with a specific number of arguments
+  ** than to function that accepts any number of arguments. */
+  if( p->nArg==nArg ){
+    match = 4;
+  }else{
     match = 1;
-    if( p->nArg==nArg || nArg==-1 ){
-      match = 4;
-    }
-    if( enc==p->iPrefEnc ){
-      match += 2;
-    }
-    else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
-             (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
-      match += 1;
-    }
   }
+
+  /* Bonus points if the text encoding matches */
+  if( enc==(p->funcFlags & SQLITE_FUNC_ENCMASK) ){
+    match += 2;  /* Exact encoding match */
+  }else if( (enc & p->funcFlags & 2)!=0 ){
+    match += 1;  /* Both are UTF16, but with different byte orders */
+  }
+
   return match;
 }
 
@@ -83524,14 +102104,12 @@ static int matchQuality(FuncDef *p, int nArg, u8 enc){
 ** a pointer to the matching FuncDef if found, or 0 if there is no match.
 */
 static FuncDef *functionSearch(
-  FuncDefHash *pHash,  /* Hash table to search */
   int h,               /* Hash of the name */
-  const char *zFunc,   /* Name of function */
-  int nFunc            /* Number of bytes in zFunc */
+  const char *zFunc    /* Name of function */
 ){
   FuncDef *p;
-  for(p=pHash->a[h]; p; p=p->pHash){
-    if( sqlite3StrNICmp(p->zName, zFunc, nFunc)==0 && p->zName[nFunc]==0 ){
+  for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
+    if( sqlite3StrICmp(p->zName, zFunc)==0 ){
       return p;
     }
   }
@@ -83541,23 +102119,26 @@ static FuncDef *functionSearch(
 /*
 ** Insert a new FuncDef into a FuncDefHash hash table.
 */
-SQLITE_PRIVATE void sqlite3FuncDefInsert(
-  FuncDefHash *pHash,  /* The hash table into which to insert */
-  FuncDef *pDef        /* The function definition to insert */
+SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(
+  FuncDef *aDef,      /* List of global functions to be inserted */
+  int nDef            /* Length of the apDef[] list */
 ){
-  FuncDef *pOther;
-  int nName = sqlite3Strlen30(pDef->zName);
-  u8 c1 = (u8)pDef->zName[0];
-  int h = (sqlite3UpperToLower[c1] + nName) % ArraySize(pHash->a);
-  pOther = functionSearch(pHash, h, pDef->zName, nName);
-  if( pOther ){
-    assert( pOther!=pDef && pOther->pNext!=pDef );
-    pDef->pNext = pOther->pNext;
-    pOther->pNext = pDef;
-  }else{
-    pDef->pNext = 0;
-    pDef->pHash = pHash->a[h];
-    pHash->a[h] = pDef;
+  int i;
+  for(i=0; i<nDef; i++){
+    FuncDef *pOther;
+    const char *zName = aDef[i].zName;
+    int nName = sqlite3Strlen30(zName);
+    int h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % SQLITE_FUNC_HASH_SZ;
+    pOther = functionSearch(h, zName);
+    if( pOther ){
+      assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );
+      aDef[i].pNext = pOther->pNext;
+      pOther->pNext = &aDef[i];
+    }else{
+      aDef[i].pNext = 0;
+      aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];
+      sqlite3BuiltinFunctions.a[h] = &aDef[i];
+    }
   }
 }
   
@@ -83571,13 +102152,12 @@ SQLITE_PRIVATE void sqlite3FuncDefInsert(
 **
 ** If the createFlag argument is true, then a new (blank) FuncDef
 ** structure is created and liked into the "db" structure if a
-** no matching function previously existed.  When createFlag is true
-** and the nArg parameter is -1, then only a function that accepts
-** any number of arguments will be returned.
+** no matching function previously existed.
 **
-** If createFlag is false and nArg is -1, then the first valid
-** function found is returned.  A function is valid if either xFunc
-** or xStep is non-zero.
+** If nArg is -2, then the first valid function found is returned.  A
+** function is valid if xSFunc is non-zero.  The nArg==(-2)
+** case is used to see if zName is a valid function name for some number
+** of arguments.  If nArg is -2, then createFlag must be 0.
 **
 ** If createFlag is false, then a function with the required name and
 ** number of arguments may be returned even if the eTextRep flag does not
@@ -83585,24 +102165,24 @@ SQLITE_PRIVATE void sqlite3FuncDefInsert(
 */
 SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   sqlite3 *db,       /* An open database */
-  const char *zName, /* Name of the function.  Not null-terminated */
-  int nName,         /* Number of characters in the name */
+  const char *zName, /* Name of the function.  zero-terminated */
   int nArg,          /* Number of arguments.  -1 means any number */
   u8 enc,            /* Preferred text encoding */
-  int createFlag     /* Create new entry if true and does not otherwise exist */
+  u8 createFlag      /* Create new entry if true and does not otherwise exist */
 ){
   FuncDef *p;         /* Iterator variable */
   FuncDef *pBest = 0; /* Best match found so far */
   int bestScore = 0;  /* Score of best match */
   int h;              /* Hash value */
+  int nName;          /* Length of the name */
 
-
-  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
-  h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % ArraySize(db->aFunc.a);
+  assert( nArg>=(-2) );
+  assert( nArg>=(-1) || createFlag==0 );
+  nName = sqlite3Strlen30(zName);
 
   /* First search for a match amongst the application-defined functions.
   */
-  p = functionSearch(&db->aFunc, h, zName, nName);
+  p = (FuncDef*)sqlite3HashFind(&db->aFunc, zName);
   while( p ){
     int score = matchQuality(p, nArg, enc);
     if( score>bestScore ){
@@ -83625,9 +102205,9 @@ SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   ** So we must not search for built-ins when creating a new function.
   */ 
   if( !createFlag && (pBest==0 || (db->flags & SQLITE_PreferBuiltin)!=0) ){
-    FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
     bestScore = 0;
-    p = functionSearch(pHash, h, zName, nName);
+    h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % SQLITE_FUNC_HASH_SZ;
+    p = functionSearch(h, zName);
     while( p ){
       int score = matchQuality(p, nArg, enc);
       if( score>bestScore ){
@@ -83642,17 +102222,24 @@ SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
   ** exact match for the name, number of arguments and encoding, then add a
   ** new entry to the hash table and return it.
   */
-  if( createFlag && (bestScore<6 || pBest->nArg!=nArg) && 
+  if( createFlag && bestScore<FUNC_PERFECT_MATCH && 
       (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
-    pBest->zName = (char *)&pBest[1];
+    FuncDef *pOther;
+    pBest->zName = (const char*)&pBest[1];
     pBest->nArg = (u16)nArg;
-    pBest->iPrefEnc = enc;
-    memcpy(pBest->zName, zName, nName);
-    pBest->zName[nName] = 0;
-    sqlite3FuncDefInsert(&db->aFunc, pBest);
+    pBest->funcFlags = enc;
+    memcpy((char*)&pBest[1], zName, nName+1);
+    pOther = (FuncDef*)sqlite3HashInsert(&db->aFunc, pBest->zName, pBest);
+    if( pOther==pBest ){
+      sqlite3DbFree(db, pBest);
+      sqlite3OomFault(db);
+      return 0;
+    }else{
+      pBest->pNext = pOther;
+    }
   }
 
-  if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
+  if( pBest && (pBest->xSFunc || createFlag) ){
     return pBest;
   }
   return 0;
@@ -83688,9 +102275,9 @@ SQLITE_PRIVATE void sqlite3SchemaClear(void *p){
   sqlite3HashClear(&temp1);
   sqlite3HashClear(&pSchema->fkeyHash);
   pSchema->pSeqTab = 0;
-  if( pSchema->flags & DB_SchemaLoaded ){
+  if( pSchema->schemaFlags & DB_SchemaLoaded ){
     pSchema->iGeneration++;
-    pSchema->flags &= ~DB_SchemaLoaded;
+    pSchema->schemaFlags &= ~DB_SchemaLoaded;
   }
 }
 
@@ -83706,7 +102293,7 @@ SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
     p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
   }
   if( !p ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }else if ( 0==p->file_format ){
     sqlite3HashInit(&p->tblHash);
     sqlite3HashInit(&p->idxHash);
@@ -83733,6 +102320,7 @@ SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
 ** This file contains C code routines that are called by the parser
 ** in order to generate code for DELETE FROM statements.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** While a SrcList can in general represent multiple tables and subqueries
@@ -83752,7 +102340,7 @@ SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
   struct SrcList_item *pItem = pSrc->a;
   Table *pTab;
   assert( pItem && pSrc->nSrc==1 );
-  pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
+  pTab = sqlite3LocateTableItem(pParse, 0, pItem);
   sqlite3DeleteTable(pParse->db, pItem->pTab);
   pItem->pTab = pTab;
   if( pTab ){
@@ -83810,32 +102398,27 @@ SQLITE_PRIVATE void sqlite3MaterializeView(
   Parse *pParse,       /* Parsing context */
   Table *pView,        /* View definition */
   Expr *pWhere,        /* Optional WHERE clause to be added */
-  int iCur             /* Cursor number for ephemerial table */
+  int iCur             /* Cursor number for ephemeral table */
 ){
   SelectDest dest;
-  Select *pDup;
+  Select *pSel;
+  SrcList *pFrom;
   sqlite3 *db = pParse->db;
-
-  pDup = sqlite3SelectDup(db, pView->pSelect, 0);
-  if( pWhere ){
-    SrcList *pFrom;
-    
-    pWhere = sqlite3ExprDup(db, pWhere, 0);
-    pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
-    if( pFrom ){
-      assert( pFrom->nSrc==1 );
-      pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName);
-      pFrom->a[0].pSelect = pDup;
-      assert( pFrom->a[0].pOn==0 );
-      assert( pFrom->a[0].pUsing==0 );
-    }else{
-      sqlite3SelectDelete(db, pDup);
-    }
-    pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0);
-  }
+  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
+  pWhere = sqlite3ExprDup(db, pWhere, 0);
+  pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
+  if( pFrom ){
+    assert( pFrom->nSrc==1 );
+    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
+    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
+    assert( pFrom->a[0].pOn==0 );
+    assert( pFrom->a[0].pUsing==0 );
+  }
+  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 
+                          SF_IncludeHidden, 0, 0);
   sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
-  sqlite3Select(pParse, pDup, &dest);
-  sqlite3SelectDelete(db, pDup);
+  sqlite3Select(pParse, pSel, &dest);
+  sqlite3SelectDelete(db, pSel);
 }
 #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
 
@@ -83855,7 +102438,7 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   ExprList *pOrderBy,          /* The ORDER BY clause.  May be null */
   Expr *pLimit,                /* The LIMIT clause.  May be null */
   Expr *pOffset,               /* The OFFSET clause.  May be null */
-  char *zStmtType              /* Either DELETE or UPDATE.  For error messages. */
+  char *zStmtType              /* Either DELETE or UPDATE.  For err msgs. */
 ){
   Expr *pWhereRowid = NULL;    /* WHERE rowid .. */
   Expr *pInClause = NULL;      /* WHERE rowid IN ( select ) */
@@ -83868,8 +102451,7 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   */
   if( pOrderBy && (pLimit == 0) ) {
     sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
-    pParse->parseError = 1;
-    goto limit_where_cleanup_2;
+    goto limit_where_cleanup;
   }
 
   /* We only need to generate a select expression if there
@@ -83891,16 +102473,16 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
   */
 
   pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
-  if( pSelectRowid == 0 ) goto limit_where_cleanup_2;
+  if( pSelectRowid == 0 ) goto limit_where_cleanup;
   pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
-  if( pEList == 0 ) goto limit_where_cleanup_2;
+  if( pEList == 0 ) goto limit_where_cleanup;
 
   /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
   ** and the SELECT subtree. */
   pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
   if( pSelectSrc == 0 ) {
     sqlite3ExprListDelete(pParse->db, pEList);
-    goto limit_where_cleanup_2;
+    goto limit_where_cleanup;
   }
 
   /* generate the SELECT expression tree. */
@@ -83910,28 +102492,19 @@ SQLITE_PRIVATE Expr *sqlite3LimitWhere(
 
   /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
   pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0);
-  if( pWhereRowid == 0 ) goto limit_where_cleanup_1;
-  pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0);
-  if( pInClause == 0 ) goto limit_where_cleanup_1;
-
-  pInClause->x.pSelect = pSelect;
-  pInClause->flags |= EP_xIsSelect;
-  sqlite3ExprSetHeight(pParse, pInClause);
+  pInClause = pWhereRowid ? sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0) : 0;
+  sqlite3PExprAddSelect(pParse, pInClause, pSelect);
   return pInClause;
 
-  /* something went wrong. clean up anything allocated. */
-limit_where_cleanup_1:
-  sqlite3SelectDelete(pParse->db, pSelect);
-  return 0;
-
-limit_where_cleanup_2:
+limit_where_cleanup:
   sqlite3ExprDelete(pParse->db, pWhere);
   sqlite3ExprListDelete(pParse->db, pOrderBy);
   sqlite3ExprDelete(pParse->db, pLimit);
   sqlite3ExprDelete(pParse->db, pOffset);
   return 0;
 }
-#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
+#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
+       /*      && !defined(SQLITE_OMIT_SUBQUERY) */
 
 /*
 ** Generate code for a DELETE FROM statement.
@@ -83948,18 +102521,35 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   Vdbe *v;               /* The virtual database engine */
   Table *pTab;           /* The table from which records will be deleted */
   const char *zDb;       /* Name of database holding pTab */
-  int end, addr = 0;     /* A couple addresses of generated code */
   int i;                 /* Loop counter */
   WhereInfo *pWInfo;     /* Information about the WHERE clause */
   Index *pIdx;           /* For looping over indices of the table */
-  int iCur;              /* VDBE Cursor number for pTab */
+  int iTabCur;           /* Cursor number for the table */
+  int iDataCur = 0;      /* VDBE cursor for the canonical data source */
+  int iIdxCur = 0;       /* Cursor number of the first index */
+  int nIdx;              /* Number of indices */
   sqlite3 *db;           /* Main database structure */
   AuthContext sContext;  /* Authorization context */
   NameContext sNC;       /* Name context to resolve expressions in */
   int iDb;               /* Database number */
   int memCnt = -1;       /* Memory cell used for change counting */
   int rcauth;            /* Value returned by authorization callback */
-
+  int eOnePass;          /* ONEPASS_OFF or _SINGLE or _MULTI */
+  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
+  u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
+  Index *pPk;            /* The PRIMARY KEY index on the table */
+  int iPk = 0;           /* First of nPk registers holding PRIMARY KEY value */
+  i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */
+  int iKey;              /* Memory cell holding key of row to be deleted */
+  i16 nKey;              /* Number of memory cells in the row key */
+  int iEphCur = 0;       /* Ephemeral table holding all primary key values */
+  int iRowSet = 0;       /* Register for rowset of rows to delete */
+  int addrBypass = 0;    /* Address of jump over the delete logic */
+  int addrLoop = 0;      /* Top of the delete loop */
+  int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
+  int bComplex;          /* True if there are triggers or FKs or
+                         ** subqueries in the WHERE clause */
+ 
 #ifndef SQLITE_OMIT_TRIGGER
   int isView;                  /* True if attempting to delete from a view */
   Trigger *pTrigger;           /* List of table triggers, if required */
@@ -83986,6 +102576,7 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
 #ifndef SQLITE_OMIT_TRIGGER
   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
   isView = pTab->pSelect!=0;
+  bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
 #else
 # define pTrigger 0
 # define isView 0
@@ -84014,11 +102605,11 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   }
   assert(!isView || pTrigger);
 
-  /* Assign  cursor number to the table and all its indices.
+  /* Assign cursor numbers to the table and all its indices.
   */
   assert( pTabList->nSrc==1 );
-  iCur = pTabList->a[0].iCursor = pParse->nTab++;
-  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+  iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
     pParse->nTab++;
   }
 
@@ -84038,11 +102629,12 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   sqlite3BeginWriteOperation(pParse, 1, iDb);
 
   /* If we are trying to delete from a view, realize that view into
-  ** a ephemeral table.
+  ** an ephemeral table.
   */
 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
   if( isView ){
-    sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
+    sqlite3MaterializeView(pParse, pTab, pWhere, iTabCur);
+    iDataCur = iIdxCur = iTabCur;
   }
 #endif
 
@@ -84068,82 +102660,202 @@ SQLITE_PRIVATE void sqlite3DeleteFrom(
   ** It is easier just to erase the whole table. Prior to version 3.6.5,
   ** this optimization caused the row change count (the value returned by 
   ** API function sqlite3_count_changes) to be set incorrectly.  */
-  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) 
-   && 0==sqlite3FkRequired(pParse, pTab, 0, 0)
+  if( rcauth==SQLITE_OK
+   && pWhere==0
+   && !bComplex
+   && !IsVirtual(pTab)
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+   && db->xPreUpdateCallback==0
+#endif
   ){
     assert( !isView );
-    sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
-                      pTab->zName, P4_STATIC);
+    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
+    if( HasRowid(pTab) ){
+      sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
+                        pTab->zName, P4_STATIC);
+    }
     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
       assert( pIdx->pSchema==pTab->pSchema );
       sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
     }
   }else
 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
-  /* The usual case: There is a WHERE clause so we have to scan through
-  ** the table and pick which records to delete.
-  */
   {
-    int iRowSet = ++pParse->nMem;   /* Register for rowset of rows to delete */
-    int iRowid = ++pParse->nMem;    /* Used for storing rowid values. */
-    int regRowid;                   /* Actual register containing rowids */
-
-    /* Collect rowids of every row to be deleted.
+    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK|WHERE_SEEK_TABLE;
+    if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
+    wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
+    if( HasRowid(pTab) ){
+      /* For a rowid table, initialize the RowSet to an empty set */
+      pPk = 0;
+      nPk = 1;
+      iRowSet = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
+    }else{
+      /* For a WITHOUT ROWID table, create an ephemeral table used to
+      ** hold all primary keys for rows to be deleted. */
+      pPk = sqlite3PrimaryKeyIndex(pTab);
+      assert( pPk!=0 );
+      nPk = pPk->nKeyCol;
+      iPk = pParse->nMem+1;
+      pParse->nMem += nPk;
+      iEphCur = pParse->nTab++;
+      addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
+      sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+    }
+  
+    /* Construct a query to find the rowid or primary key for every row
+    ** to be deleted, based on the WHERE clause. Set variable eOnePass
+    ** to indicate the strategy used to implement this delete:
+    **
+    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
+    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
+    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
     */
-    sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
-    pWInfo = sqlite3WhereBegin(
-        pParse, pTabList, pWhere, 0, 0, WHERE_DUPLICATES_OK
-    );
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);
     if( pWInfo==0 ) goto delete_from_cleanup;
-    regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid);
-    sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
+    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
+    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
+  
+    /* Keep track of the number of rows to be deleted */
     if( db->flags & SQLITE_CountRows ){
       sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
     }
-    sqlite3WhereEnd(pWInfo);
-
-    /* Delete every item whose key was written to the list during the
-    ** database scan.  We have to delete items after the scan is complete
-    ** because deleting an item can change the scan order.  */
-    end = sqlite3VdbeMakeLabel(v);
-
+  
+    /* Extract the rowid or primary key for the current row */
+    if( pPk ){
+      for(i=0; i<nPk; i++){
+        assert( pPk->aiColumn[i]>=0 );
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
+                                        pPk->aiColumn[i], iPk+i);
+      }
+      iKey = iPk;
+    }else{
+      iKey = pParse->nMem + 1;
+      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
+      if( iKey>pParse->nMem ) pParse->nMem = iKey;
+    }
+  
+    if( eOnePass!=ONEPASS_OFF ){
+      /* For ONEPASS, no need to store the rowid/primary-key. There is only
+      ** one, so just keep it in its register(s) and fall through to the
+      ** delete code.  */
+      nKey = nPk; /* OP_Found will use an unpacked key */
+      aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);
+      if( aToOpen==0 ){
+        sqlite3WhereEnd(pWInfo);
+        goto delete_from_cleanup;
+      }
+      memset(aToOpen, 1, nIdx+1);
+      aToOpen[nIdx+1] = 0;
+      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
+      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
+      if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
+    }else{
+      if( pPk ){
+        /* Add the PK key for this row to the temporary table */
+        iKey = ++pParse->nMem;
+        nKey = 0;   /* Zero tells OP_Found to use a composite key */
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
+            sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
+        sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey);
+      }else{
+        /* Add the rowid of the row to be deleted to the RowSet */
+        nKey = 1;  /* OP_Seek always uses a single rowid */
+        sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
+      }
+    }
+  
+    /* If this DELETE cannot use the ONEPASS strategy, this is the 
+    ** end of the WHERE loop */
+    if( eOnePass!=ONEPASS_OFF ){
+      addrBypass = sqlite3VdbeMakeLabel(v);
+    }else{
+      sqlite3WhereEnd(pWInfo);
+    }
+  
     /* Unless this is a view, open cursors for the table we are 
     ** deleting from and all its indices. If this is a view, then the
     ** only effect this statement has is to fire the INSTEAD OF 
-    ** triggers.  */
+    ** triggers.
+    */
     if( !isView ){
-      sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite);
+      int iAddrOnce = 0;
+      if( eOnePass==ONEPASS_MULTI ){
+        iAddrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+      }
+      testcase( IsVirtual(pTab) );
+      sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
+                                 iTabCur, aToOpen, &iDataCur, &iIdxCur);
+      assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
+      assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
+      if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);
     }
-
-    addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
-
+  
+    /* Set up a loop over the rowids/primary-keys that were found in the
+    ** where-clause loop above.
+    */
+    if( eOnePass!=ONEPASS_OFF ){
+      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
+      if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
+        assert( pPk!=0 || pTab->pSelect!=0 );
+        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
+        VdbeCoverage(v);
+      }
+    }else if( pPk ){
+      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
+      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
+      assert( nKey==0 );  /* OP_Found will use a composite key */
+    }else{
+      addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
+      VdbeCoverage(v);
+      assert( nKey==1 );
+    }  
+  
     /* Delete the row */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     if( IsVirtual(pTab) ){
       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
       sqlite3VtabMakeWritable(pParse, pTab);
-      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB);
+      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
       sqlite3VdbeChangeP5(v, OE_Abort);
+      assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
       sqlite3MayAbort(pParse);
+      if( eOnePass==ONEPASS_SINGLE && sqlite3IsToplevel(pParse) ){
+        pParse->isMultiWrite = 0;
+      }
     }else
 #endif
     {
       int count = (pParse->nested==0);    /* True to count changes */
-      sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, count, pTrigger, OE_Default);
+      int iIdxNoSeek = -1;
+      if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
+        iIdxNoSeek = aiCurOnePass[1];
+      }
+      sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
+          iKey, nKey, count, OE_Default, eOnePass, iIdxNoSeek);
     }
-
-    /* End of the delete loop */
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
-    sqlite3VdbeResolveLabel(v, end);
-
+  
+    /* End of the loop over all rowids/primary-keys. */
+    if( eOnePass!=ONEPASS_OFF ){
+      sqlite3VdbeResolveLabel(v, addrBypass);
+      sqlite3WhereEnd(pWInfo);
+    }else if( pPk ){
+      sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
+      sqlite3VdbeJumpHere(v, addrLoop);
+    }else{
+      sqlite3VdbeGoto(v, addrLoop);
+      sqlite3VdbeJumpHere(v, addrLoop);
+    }     
+  
     /* Close the cursors open on the table and its indexes. */
     if( !isView && !IsVirtual(pTab) ){
-      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
-        sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
+      if( !pPk ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
+      for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
+        sqlite3VdbeAddOp1(v, OP_Close, iIdxCur + i);
       }
-      sqlite3VdbeAddOp1(v, OP_Close, iCur);
     }
-  }
+  } /* End non-truncate path */
 
   /* Update the sqlite_sequence table by storing the content of the
   ** maximum rowid counter values recorded while inserting into
@@ -84167,10 +102879,11 @@ delete_from_cleanup:
   sqlite3AuthContextPop(&sContext);
   sqlite3SrcListDelete(db, pTabList);
   sqlite3ExprDelete(db, pWhere);
+  sqlite3DbFree(db, aToOpen);
   return;
 }
 /* Make sure "isView" and other macros defined above are undefined. Otherwise
-** thely may interfere with compilation of other functions in this file
+** they may interfere with compilation of other functions in this file
 ** (or in another file, if this file becomes part of the amalgamation).  */
 #ifdef isView
  #undef isView
@@ -84181,50 +102894,83 @@ delete_from_cleanup:
 
 /*
 ** This routine generates VDBE code that causes a single row of a
-** single table to be deleted.
+** single table to be deleted.  Both the original table entry and
+** all indices are removed.
 **
-** The VDBE must be in a particular state when this routine is called.
-** These are the requirements:
+** Preconditions:
 **
-**   1.  A read/write cursor pointing to pTab, the table containing the row
-**       to be deleted, must be opened as cursor number $iCur.
+**   1.  iDataCur is an open cursor on the btree that is the canonical data
+**       store for the table.  (This will be either the table itself,
+**       in the case of a rowid table, or the PRIMARY KEY index in the case
+**       of a WITHOUT ROWID table.)
 **
 **   2.  Read/write cursors for all indices of pTab must be open as
-**       cursor number base+i for the i-th index.
-**
-**   3.  The record number of the row to be deleted must be stored in
-**       memory cell iRowid.
-**
-** This routine generates code to remove both the table record and all 
-** index entries that point to that record.
+**       cursor number iIdxCur+i for the i-th index.
+**
+**   3.  The primary key for the row to be deleted must be stored in a
+**       sequence of nPk memory cells starting at iPk.  If nPk==0 that means
+**       that a search record formed from OP_MakeRecord is contained in the
+**       single memory location iPk.
+**
+** eMode:
+**   Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
+**   ONEPASS_MULTI.  If eMode is not ONEPASS_OFF, then the cursor
+**   iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
+**   then this function must seek iDataCur to the entry identified by iPk
+**   and nPk before reading from it.
+**
+**   If eMode is ONEPASS_MULTI, then this call is being made as part
+**   of a ONEPASS delete that affects multiple rows. In this case, if 
+**   iIdxNoSeek is a valid cursor number (>=0), then its position should
+**   be preserved following the delete operation. Or, if iIdxNoSeek is not
+**   a valid cursor number, the position of iDataCur should be preserved
+**   instead.
+**
+** iIdxNoSeek:
+**   If iIdxNoSeek is a valid cursor number (>=0), then it identifies an
+**   index cursor (from within array of cursors starting at iIdxCur) that
+**   already points to the index entry to be deleted.
 */
 SQLITE_PRIVATE void sqlite3GenerateRowDelete(
   Parse *pParse,     /* Parsing context */
   Table *pTab,       /* Table containing the row to be deleted */
-  int iCur,          /* Cursor number for the table */
-  int iRowid,        /* Memory cell that contains the rowid to delete */
-  int count,         /* If non-zero, increment the row change counter */
   Trigger *pTrigger, /* List of triggers to (potentially) fire */
-  int onconf         /* Default ON CONFLICT policy for triggers */
+  int iDataCur,      /* Cursor from which column data is extracted */
+  int iIdxCur,       /* First index cursor */
+  int iPk,           /* First memory cell containing the PRIMARY KEY */
+  i16 nPk,           /* Number of PRIMARY KEY memory cells */
+  u8 count,          /* If non-zero, increment the row change counter */
+  u8 onconf,         /* Default ON CONFLICT policy for triggers */
+  u8 eMode,          /* ONEPASS_OFF, _SINGLE, or _MULTI.  See above */
+  int iIdxNoSeek     /* Cursor number of cursor that does not need seeking */
 ){
   Vdbe *v = pParse->pVdbe;        /* Vdbe */
   int iOld = 0;                   /* First register in OLD.* array */
   int iLabel;                     /* Label resolved to end of generated code */
+  u8 opSeek;                      /* Seek opcode */
 
   /* Vdbe is guaranteed to have been allocated by this stage. */
   assert( v );
+  VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
+                         iDataCur, iIdxCur, iPk, (int)nPk));
 
   /* Seek cursor iCur to the row to delete. If this row no longer exists 
   ** (this can happen if a trigger program has already deleted it), do
   ** not attempt to delete it or fire any DELETE triggers.  */
   iLabel = sqlite3VdbeMakeLabel(v);
-  sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);
+  opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
+  if( eMode==ONEPASS_OFF ){
+    sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
+    VdbeCoverageIf(v, opSeek==OP_NotExists);
+    VdbeCoverageIf(v, opSeek==OP_NotFound);
+  }
  
   /* If there are any triggers to fire, allocate a range of registers to
   ** use for the old.* references in the triggers.  */
   if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){
     u32 mask;                     /* Mask of OLD.* columns in use */
     int iCol;                     /* Iterator used while populating OLD.* */
+    int addrStart;                /* Start of BEFORE trigger programs */
 
     /* TODO: Could use temporary registers here. Also could attempt to
     ** avoid copying the contents of the rowid register.  */
@@ -84237,45 +102983,67 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
 
     /* Populate the OLD.* pseudo-table register array. These values will be 
     ** used by any BEFORE and AFTER triggers that exist.  */
-    sqlite3VdbeAddOp2(v, OP_Copy, iRowid, iOld);
+    sqlite3VdbeAddOp2(v, OP_Copy, iPk, iOld);
     for(iCol=0; iCol<pTab->nCol; iCol++){
-      if( mask==0xffffffff || mask&(1<<iCol) ){
-        sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol, iOld+iCol+1);
+      testcase( mask!=0xffffffff && iCol==31 );
+      testcase( mask!=0xffffffff && iCol==32 );
+      if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+iCol+1);
       }
     }
 
     /* Invoke BEFORE DELETE trigger programs. */
+    addrStart = sqlite3VdbeCurrentAddr(v);
     sqlite3CodeRowTrigger(pParse, pTrigger, 
         TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
     );
 
-    /* Seek the cursor to the row to be deleted again. It may be that
-    ** the BEFORE triggers coded above have already removed the row
-    ** being deleted. Do not attempt to delete the row a second time, and 
-    ** do not fire AFTER triggers.  */
-    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);
+    /* If any BEFORE triggers were coded, then seek the cursor to the 
+    ** row to be deleted again. It may be that the BEFORE triggers moved
+    ** the cursor or of already deleted the row that the cursor was
+    ** pointing to.
+    */
+    if( addrStart<sqlite3VdbeCurrentAddr(v) ){
+      sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
+      VdbeCoverageIf(v, opSeek==OP_NotExists);
+      VdbeCoverageIf(v, opSeek==OP_NotFound);
+    }
 
     /* Do FK processing. This call checks that any FK constraints that
     ** refer to this table (i.e. constraints attached to other tables) 
     ** are not violated by deleting this row.  */
-    sqlite3FkCheck(pParse, pTab, iOld, 0);
+    sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
   }
 
   /* Delete the index and table entries. Skip this step if pTab is really
   ** a view (in which case the only effect of the DELETE statement is to
-  ** fire the INSTEAD OF triggers).  */ 
+  ** fire the INSTEAD OF triggers).  
+  **
+  ** If variable 'count' is non-zero, then this OP_Delete instruction should
+  ** invoke the update-hook. The pre-update-hook, on the other hand should
+  ** be invoked unless table pTab is a system table. The difference is that
+  ** the update-hook is not invoked for rows removed by REPLACE, but the 
+  ** pre-update-hook is.
+  */ 
   if( pTab->pSelect==0 ){
-    sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0);
-    sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
-    if( count ){
-      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
+    u8 p5 = 0;
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
+    sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
+    sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE);
+    if( eMode!=ONEPASS_OFF ){
+      sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);
+    }
+    if( iIdxNoSeek>=0 ){
+      sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
     }
+    if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;
+    sqlite3VdbeChangeP5(v, p5);
   }
 
   /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
   ** handle rows (possibly in other tables) that refer via a foreign key
   ** to the row just deleted. */ 
-  sqlite3FkActions(pParse, pTab, 0, iOld);
+  sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);
 
   /* Invoke AFTER DELETE trigger programs. */
   sqlite3CodeRowTrigger(pParse, pTrigger, 
@@ -84286,91 +103054,156 @@ SQLITE_PRIVATE void sqlite3GenerateRowDelete(
   ** trigger programs were invoked. Or if a trigger program throws a 
   ** RAISE(IGNORE) exception.  */
   sqlite3VdbeResolveLabel(v, iLabel);
+  VdbeModuleComment((v, "END: GenRowDel()"));
 }
 
 /*
 ** This routine generates VDBE code that causes the deletion of all
-** index entries associated with a single row of a single table.
+** index entries associated with a single row of a single table, pTab
 **
-** The VDBE must be in a particular state when this routine is called.
-** These are the requirements:
+** Preconditions:
 **
-**   1.  A read/write cursor pointing to pTab, the table containing the row
-**       to be deleted, must be opened as cursor number "iCur".
+**   1.  A read/write cursor "iDataCur" must be open on the canonical storage
+**       btree for the table pTab.  (This will be either the table itself
+**       for rowid tables or to the primary key index for WITHOUT ROWID
+**       tables.)
 **
 **   2.  Read/write cursors for all indices of pTab must be open as
-**       cursor number iCur+i for the i-th index.
+**       cursor number iIdxCur+i for the i-th index.  (The pTab->pIndex
+**       index is the 0-th index.)
 **
-**   3.  The "iCur" cursor must be pointing to the row that is to be
-**       deleted.
+**   3.  The "iDataCur" cursor must be already be positioned on the row
+**       that is to be deleted.
 */
 SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(
   Parse *pParse,     /* Parsing and code generating context */
   Table *pTab,       /* Table containing the row to be deleted */
-  int iCur,          /* Cursor number for the table */
-  int *aRegIdx       /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
-){
-  int i;
-  Index *pIdx;
-  int r1;
+  int iDataCur,      /* Cursor of table holding data. */
+  int iIdxCur,       /* First index cursor */
+  int *aRegIdx,      /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
+  int iIdxNoSeek     /* Do not delete from this cursor */
+){
+  int i;             /* Index loop counter */
+  int r1 = -1;       /* Register holding an index key */
+  int iPartIdxLabel; /* Jump destination for skipping partial index entries */
+  Index *pIdx;       /* Current index */
+  Index *pPrior = 0; /* Prior index */
+  Vdbe *v;           /* The prepared statement under construction */
+  Index *pPk;        /* PRIMARY KEY index, or NULL for rowid tables */
 
-  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
-    if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
-    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
-    sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
+  v = pParse->pVdbe;
+  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
+  for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
+    assert( iIdxCur+i!=iDataCur || pPk==pIdx );
+    if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
+    if( pIdx==pPk ) continue;
+    if( iIdxCur+i==iIdxNoSeek ) continue;
+    VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
+    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
+        &iPartIdxLabel, pPrior, r1);
+    sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
+        pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
+    sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
+    pPrior = pIdx;
   }
 }
 
 /*
-** Generate code that will assemble an index key and put it in register
+** Generate code that will assemble an index key and stores it in register
 ** regOut.  The key with be for index pIdx which is an index on pTab.
 ** iCur is the index of a cursor open on the pTab table and pointing to
-** the entry that needs indexing.
+** the entry that needs indexing.  If pTab is a WITHOUT ROWID table, then
+** iCur must be the cursor of the PRIMARY KEY index.
 **
 ** Return a register number which is the first in a block of
 ** registers that holds the elements of the index key.  The
 ** block of registers has already been deallocated by the time
 ** this routine returns.
+**
+** If *piPartIdxLabel is not NULL, fill it in with a label and jump
+** to that label if pIdx is a partial index that should be skipped.
+** The label should be resolved using sqlite3ResolvePartIdxLabel().
+** A partial index should be skipped if its WHERE clause evaluates
+** to false or null.  If pIdx is not a partial index, *piPartIdxLabel
+** will be set to zero which is an empty label that is ignored by
+** sqlite3ResolvePartIdxLabel().
+**
+** The pPrior and regPrior parameters are used to implement a cache to
+** avoid unnecessary register loads.  If pPrior is not NULL, then it is
+** a pointer to a different index for which an index key has just been
+** computed into register regPrior.  If the current pIdx index is generating
+** its key into the same sequence of registers and if pPrior and pIdx share
+** a column in common, then the register corresponding to that column already
+** holds the correct value and the loading of that register is skipped.
+** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK 
+** on a table with multiple indices, and especially with the ROWID or
+** PRIMARY KEY columns of the index.
 */
 SQLITE_PRIVATE int sqlite3GenerateIndexKey(
-  Parse *pParse,     /* Parsing context */
-  Index *pIdx,       /* The index for which to generate a key */
-  int iCur,          /* Cursor number for the pIdx->pTable table */
-  int regOut,        /* Write the new index key to this register */
-  int doMakeRec      /* Run the OP_MakeRecord instruction if true */
+  Parse *pParse,       /* Parsing context */
+  Index *pIdx,         /* The index for which to generate a key */
+  int iDataCur,        /* Cursor number from which to take column data */
+  int regOut,          /* Put the new key into this register if not 0 */
+  int prefixOnly,      /* Compute only a unique prefix of the key */
+  int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */
+  Index *pPrior,       /* Previously generated index key */
+  int regPrior         /* Register holding previous generated key */
 ){
   Vdbe *v = pParse->pVdbe;
   int j;
-  Table *pTab = pIdx->pTable;
   int regBase;
   int nCol;
 
-  nCol = pIdx->nColumn;
-  regBase = sqlite3GetTempRange(pParse, nCol+1);
-  sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
-  for(j=0; j<nCol; j++){
-    int idx = pIdx->aiColumn[j];
-    if( idx==pTab->iPKey ){
-      sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
+  if( piPartIdxLabel ){
+    if( pIdx->pPartIdxWhere ){
+      *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
+      pParse->iSelfTab = iDataCur;
+      sqlite3ExprCachePush(pParse);
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
+                            SQLITE_JUMPIFNULL);
     }else{
-      sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
-      sqlite3ColumnDefault(v, pTab, idx, -1);
+      *piPartIdxLabel = 0;
     }
   }
-  if( doMakeRec ){
-    const char *zAff;
-    if( pTab->pSelect || (pParse->db->flags & SQLITE_IdxRealAsInt)!=0 ){
-      zAff = 0;
-    }else{
-      zAff = sqlite3IndexAffinityStr(v, pIdx);
+  nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
+  regBase = sqlite3GetTempRange(pParse, nCol);
+  if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
+  for(j=0; j<nCol; j++){
+    if( pPrior
+     && pPrior->aiColumn[j]==pIdx->aiColumn[j]
+     && pPrior->aiColumn[j]!=XN_EXPR
+    ){
+      /* This column was already computed by the previous index */
+      continue;
     }
-    sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
-    sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT);
+    sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
+    /* If the column affinity is REAL but the number is an integer, then it
+    ** might be stored in the table as an integer (using a compact
+    ** representation) then converted to REAL by an OP_RealAffinity opcode.
+    ** But we are getting ready to store this value back into an index, where
+    ** it should be converted by to INTEGER again.  So omit the OP_RealAffinity
+    ** opcode if it is present */
+    sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);
   }
-  sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
+  if( regOut ){
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
+  }
+  sqlite3ReleaseTempRange(pParse, regBase, nCol);
   return regBase;
 }
 
+/*
+** If a prior call to sqlite3GenerateIndexKey() generated a jump-over label
+** because it was a partial index, then this routine should be called to
+** resolve that label.
+*/
+SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){
+  if( iLabel ){
+    sqlite3VdbeResolveLabel(pParse->pVdbe, iLabel);
+    sqlite3ExprCachePop(pParse);
+  }
+}
+
 /************** End of delete.c **********************************************/
 /************** Begin file func.c ********************************************/
 /*
@@ -84384,21 +103217,33 @@ SQLITE_PRIVATE int sqlite3GenerateIndexKey(
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file contains the C functions that implement various SQL
-** functions of SQLite.  
-**
-** There is only one exported symbol in this file - the function
-** sqliteRegisterBuildinFunctions() found at the bottom of the file.
-** All other code has file scope.
+** This file contains the C-language implementations for many of the SQL
+** functions of SQLite.  (Some function, and in particular the date and
+** time functions, are implemented separately.)
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 /* #include <assert.h> */
+/* #include "vdbeInt.h" */
 
 /*
 ** Return the collating function associated with a function.
 */
 static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
-  return context->pColl;
+  VdbeOp *pOp;
+  assert( context->pVdbe!=0 );
+  pOp = &context->pVdbe->aOp[context->iOp-1];
+  assert( pOp->opcode==OP_CollSeq );
+  assert( pOp->p4type==P4_COLLSEQ );
+  return pOp->p4.pColl;
+}
+
+/*
+** Indicate that the accumulator load should be skipped on this
+** iteration of the aggregate loop.
+*/
+static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){
+  context->skipFlag = 1;
 }
 
 /*
@@ -84502,9 +103347,9 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
     case SQLITE_INTEGER: {
       i64 iVal = sqlite3_value_int64(argv[0]);
       if( iVal<0 ){
-        if( (iVal<<1)==0 ){
-          /* IMP: R-35460-15084 If X is the integer -9223372036854775807 then
-          ** abs(X) throws an integer overflow error since there is no
+        if( iVal==SMALLEST_INT64 ){
+          /* IMP: R-31676-45509 If X is the integer -9223372036854775808
+          ** then abs(X) throws an integer overflow error since there is no
           ** equivalent positive 64-bit two complement value. */
           sqlite3_result_error(context, "integer overflow", -1);
           return;
@@ -84522,8 +103367,8 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
     default: {
       /* Because sqlite3_value_double() returns 0.0 if the argument is not
       ** something that can be converted into a number, we have:
-      ** IMP: R-57326-31541 Abs(X) return 0.0 if X is a string or blob that
-      ** cannot be converted to a numeric value. 
+      ** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob
+      ** that cannot be converted to a numeric value.
       */
       double rVal = sqlite3_value_double(argv[0]);
       if( rVal<0 ) rVal = -rVal;
@@ -84534,6 +103379,83 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 }
 
 /*
+** Implementation of the instr() function.
+**
+** instr(haystack,needle) finds the first occurrence of needle
+** in haystack and returns the number of previous characters plus 1,
+** or 0 if needle does not occur within haystack.
+**
+** If both haystack and needle are BLOBs, then the result is one more than
+** the number of bytes in haystack prior to the first occurrence of needle,
+** or 0 if needle never occurs in haystack.
+*/
+static void instrFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zHaystack;
+  const unsigned char *zNeedle;
+  int nHaystack;
+  int nNeedle;
+  int typeHaystack, typeNeedle;
+  int N = 1;
+  int isText;
+
+  UNUSED_PARAMETER(argc);
+  typeHaystack = sqlite3_value_type(argv[0]);
+  typeNeedle = sqlite3_value_type(argv[1]);
+  if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
+  nHaystack = sqlite3_value_bytes(argv[0]);
+  nNeedle = sqlite3_value_bytes(argv[1]);
+  if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
+    zHaystack = sqlite3_value_blob(argv[0]);
+    zNeedle = sqlite3_value_blob(argv[1]);
+    isText = 0;
+  }else{
+    zHaystack = sqlite3_value_text(argv[0]);
+    zNeedle = sqlite3_value_text(argv[1]);
+    isText = 1;
+  }
+  while( nNeedle<=nHaystack && memcmp(zHaystack, zNeedle, nNeedle)!=0 ){
+    N++;
+    do{
+      nHaystack--;
+      zHaystack++;
+    }while( isText && (zHaystack[0]&0xc0)==0x80 );
+  }
+  if( nNeedle>nHaystack ) N = 0;
+  sqlite3_result_int(context, N);
+}
+
+/*
+** Implementation of the printf() function.
+*/
+static void printfFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  PrintfArguments x;
+  StrAccum str;
+  const char *zFormat;
+  int n;
+  sqlite3 *db = sqlite3_context_db_handle(context);
+
+  if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){
+    x.nArg = argc-1;
+    x.nUsed = 0;
+    x.apArg = argv+1;
+    sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
+    str.printfFlags = SQLITE_PRINTF_SQLFUNC;
+    sqlite3XPrintf(&str, zFormat, &x);
+    n = str.nChar;
+    sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
+                        SQLITE_DYNAMIC);
+  }
+}
+
+/*
 ** Implementation of the substr() function.
 **
 ** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
@@ -84543,7 +103465,7 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 **
 ** If p1 is negative, then we begin abs(p1) from the end of x[].
 **
-** If p2 is negative, return the p2 characters preceeding p1.
+** If p2 is negative, return the p2 characters preceding p1.
 */
 static void substrFunc(
   sqlite3_context *context,
@@ -84580,6 +103502,14 @@ static void substrFunc(
       }
     }
   }
+#ifdef SQLITE_SUBSTR_COMPATIBILITY
+  /* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as
+  ** as substr(X,1,N) - it returns the first N characters of X.  This
+  ** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]
+  ** from 2009-02-02 for compatibility of applications that exploited the
+  ** old buggy behavior. */
+  if( p1==0 ) p1 = 1; /* <rdar://problem/6778339> */
+#endif
   if( argc==3 ){
     p2 = sqlite3_value_int(argv[2]);
     if( p2<0 ){
@@ -84617,13 +103547,14 @@ static void substrFunc(
     for(z2=z; *z2 && p2; p2--){
       SQLITE_SKIP_UTF8(z2);
     }
-    sqlite3_result_text(context, (char*)z, (int)(z2-z), SQLITE_TRANSIENT);
+    sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,
+                          SQLITE_UTF8);
   }else{
     if( p1+p2>len ){
       p2 = len-p1;
       if( p2<0 ) p2 = 0;
     }
-    sqlite3_result_blob(context, (char*)&z[p1], (int)p2, SQLITE_TRANSIENT);
+    sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);
   }
 }
 
@@ -84666,7 +103597,7 @@ static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 #endif
 
 /*
-** Allocate nByte bytes of space using sqlite3_malloc(). If the
+** Allocate nByte bytes of space using sqlite3Malloc(). If the
 ** allocation fails, call sqlite3_result_error_nomem() to notify
 ** the database handle that malloc() has failed and return NULL.
 ** If nByte is larger than the maximum string or blob length, then
@@ -84682,7 +103613,7 @@ static void *contextMalloc(sqlite3_context *context, i64 nByte){
     sqlite3_result_error_toobig(context);
     z = 0;
   }else{
-    z = sqlite3Malloc((int)nByte);
+    z = sqlite3Malloc(nByte);
     if( !z ){
       sqlite3_result_error_nomem(context);
     }
@@ -84732,34 +103663,15 @@ static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   }
 }
 
-
-#if 0  /* This function is never used. */
-/*
-** The COALESCE() and IFNULL() functions used to be implemented as shown
-** here.  But now they are implemented as VDBE code so that unused arguments
-** do not have to be computed.  This legacy implementation is retained as
-** comment.
-*/
 /*
-** Implementation of the IFNULL(), NVL(), and COALESCE() functions.  
-** All three do the same thing.  They return the first non-NULL
-** argument.
+** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented
+** as VDBE code so that unused argument values do not have to be computed.
+** However, we still need some kind of function implementation for this
+** routines in the function table.  The noopFunc macro provides this.
+** noopFunc will never be called so it doesn't matter what the implementation
+** is.  We might as well use the "version()" function as a substitute.
 */
-static void ifnullFunc(
-  sqlite3_context *context,
-  int argc,
-  sqlite3_value **argv
-){
-  int i;
-  for(i=0; i<argc; i++){
-    if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
-      sqlite3_result_value(context, argv[i]);
-      break;
-    }
-  }
-}
-#endif /* NOT USED */
-#define ifnullFunc versionFunc   /* Substitute function - never called */
+#define noopFunc versionFunc   /* Substitute function - never called */
 
 /*
 ** Implementation of random().  Return a random integer.  
@@ -84781,7 +103693,7 @@ static void randomFunc(
     ** 2s complement of that positive value.  The end result can
     ** therefore be no less than -9223372036854775807.
     */
-    r = -(r ^ (((sqlite3_int64)1)<<63));
+    r = -(r & LARGEST_INT64);
   }
   sqlite3_result_int64(context, r);
 }
@@ -84864,23 +103776,23 @@ static void total_changes(
 ** A structure defining how to do GLOB-style comparisons.
 */
 struct compareInfo {
-  u8 matchAll;
-  u8 matchOne;
-  u8 matchSet;
-  u8 noCase;
+  u8 matchAll;          /* "*" or "%" */
+  u8 matchOne;          /* "?" or "_" */
+  u8 matchSet;          /* "[" or 0 */
+  u8 noCase;            /* true to ignore case differences */
 };
 
 /*
 ** For LIKE and GLOB matching on EBCDIC machines, assume that every
-** character is exactly one byte in size.  Also, all characters are
-** able to participate in upper-case-to-lower-case mappings in EBCDIC
-** whereas only characters less than 0x80 do in ASCII.
+** character is exactly one byte in size.  Also, provde the Utf8Read()
+** macro for fast reading of the next character in the common case where
+** the next character is ASCII.
 */
 #if defined(SQLITE_EBCDIC)
-# define sqlite3Utf8Read(A,C)  (*(A++))
-# define GlogUpperToLower(A)   A = sqlite3UpperToLower[A]
+# define sqlite3Utf8Read(A)        (*((*A)++))
+# define Utf8Read(A)               (*(A++))
 #else
-# define GlogUpperToLower(A)   if( !((A)&~0x7f) ){ A = sqlite3UpperToLower[A]; }
+# define Utf8Read(A)               (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))
 #endif
 
 static const struct compareInfo globInfo = { '*', '?', '[', 0 };
@@ -84893,7 +103805,7 @@ static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
 
 /*
 ** Compare two UTF-8 strings for equality where the first string can
-** potentially be a "glob" expression.  Return true (1) if they
+** potentially be a "glob" or "like" expression.  Return true (1) if they
 ** are the same and false (0) if they are different.
 **
 ** Globbing rules:
@@ -84913,121 +103825,153 @@ static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
 ** "[a-z]" matches any single lower-case letter.  To match a '-', make
 ** it the last character in the list.
 **
-** This routine is usually quick, but can be N**2 in the worst case.
+** Like matching rules:
+** 
+**      '%'       Matches any sequence of zero or more characters
+**
+***     '_'       Matches any one character
 **
-** Hints: to match '*' or '?', put them in "[]".  Like this:
+**      Ec        Where E is the "esc" character and c is any other
+**                character, including '%', '_', and esc, match exactly c.
 **
-**         abc[*]xyz        Matches "abc*xyz" only
+** The comments within this routine usually assume glob matching.
+**
+** This routine is usually quick, but can be N**2 in the worst case.
 */
 static int patternCompare(
   const u8 *zPattern,              /* The glob pattern */
   const u8 *zString,               /* The string to compare against the glob */
   const struct compareInfo *pInfo, /* Information about how to do the compare */
-  u32 esc                          /* The escape character */
-){
-  u32 c, c2;
-  int invert;
-  int seen;
-  u8 matchOne = pInfo->matchOne;
-  u8 matchAll = pInfo->matchAll;
-  u8 matchSet = pInfo->matchSet;
-  u8 noCase = pInfo->noCase; 
-  int prevEscape = 0;     /* True if the previous character was 'escape' */
-
-  while( (c = sqlite3Utf8Read(zPattern,&zPattern))!=0 ){
-    if( !prevEscape && c==matchAll ){
-      while( (c=sqlite3Utf8Read(zPattern,&zPattern)) == matchAll
-               || c == matchOne ){
-        if( c==matchOne && sqlite3Utf8Read(zString, &zString)==0 ){
+  u32 matchOther                   /* The escape char (LIKE) or '[' (GLOB) */
+){
+  u32 c, c2;                       /* Next pattern and input string chars */
+  u32 matchOne = pInfo->matchOne;  /* "?" or "_" */
+  u32 matchAll = pInfo->matchAll;  /* "*" or "%" */
+  u8 noCase = pInfo->noCase;       /* True if uppercase==lowercase */
+  const u8 *zEscaped = 0;          /* One past the last escaped input char */
+  
+  while( (c = Utf8Read(zPattern))!=0 ){
+    if( c==matchAll ){  /* Match "*" */
+      /* Skip over multiple "*" characters in the pattern.  If there
+      ** are also "?" characters, skip those as well, but consume a
+      ** single character of the input string for each "?" skipped */
+      while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
+        if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
           return 0;
         }
       }
       if( c==0 ){
-        return 1;
-      }else if( c==esc ){
-        c = sqlite3Utf8Read(zPattern, &zPattern);
-        if( c==0 ){
-          return 0;
-        }
-      }else if( c==matchSet ){
-        assert( esc==0 );         /* This is GLOB, not LIKE */
-        assert( matchSet<0x80 );  /* '[' is a single-byte character */
-        while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
-          SQLITE_SKIP_UTF8(zString);
+        return 1;   /* "*" at the end of the pattern matches */
+      }else if( c==matchOther ){
+        if( pInfo->matchSet==0 ){
+          c = sqlite3Utf8Read(&zPattern);
+          if( c==0 ) return 0;
+        }else{
+          /* "[...]" immediately follows the "*".  We have to do a slow
+          ** recursive search in this case, but it is an unusual case. */
+          assert( matchOther<0x80 );  /* '[' is a single-byte character */
+          while( *zString
+                 && patternCompare(&zPattern[-1],zString,pInfo,matchOther)==0 ){
+            SQLITE_SKIP_UTF8(zString);
+          }
+          return *zString!=0;
         }
-        return *zString!=0;
       }
-      while( (c2 = sqlite3Utf8Read(zString,&zString))!=0 ){
+
+      /* At this point variable c contains the first character of the
+      ** pattern string past the "*".  Search in the input string for the
+      ** first matching character and recursively contine the match from
+      ** that point.
+      **
+      ** For a case-insensitive search, set variable cx to be the same as
+      ** c but in the other case and search the input string for either
+      ** c or cx.
+      */
+      if( c<=0x80 ){
+        u32 cx;
         if( noCase ){
-          GlogUpperToLower(c2);
-          GlogUpperToLower(c);
-          while( c2 != 0 && c2 != c ){
-            c2 = sqlite3Utf8Read(zString, &zString);
-            GlogUpperToLower(c2);
-          }
+          cx = sqlite3Toupper(c);
+          c = sqlite3Tolower(c);
         }else{
-          while( c2 != 0 && c2 != c ){
-            c2 = sqlite3Utf8Read(zString, &zString);
-          }
+          cx = c;
+        }
+        while( (c2 = *(zString++))!=0 ){
+          if( c2!=c && c2!=cx ) continue;
+          if( patternCompare(zPattern,zString,pInfo,matchOther) ) return 1;
+        }
+      }else{
+        while( (c2 = Utf8Read(zString))!=0 ){
+          if( c2!=c ) continue;
+          if( patternCompare(zPattern,zString,pInfo,matchOther) ) return 1;
         }
-        if( c2==0 ) return 0;
-        if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
       }
       return 0;
-    }else if( !prevEscape && c==matchOne ){
-      if( sqlite3Utf8Read(zString, &zString)==0 ){
-        return 0;
-      }
-    }else if( c==matchSet ){
-      u32 prior_c = 0;
-      assert( esc==0 );    /* This only occurs for GLOB, not LIKE */
-      seen = 0;
-      invert = 0;
-      c = sqlite3Utf8Read(zString, &zString);
-      if( c==0 ) return 0;
-      c2 = sqlite3Utf8Read(zPattern, &zPattern);
-      if( c2=='^' ){
-        invert = 1;
-        c2 = sqlite3Utf8Read(zPattern, &zPattern);
-      }
-      if( c2==']' ){
-        if( c==']' ) seen = 1;
-        c2 = sqlite3Utf8Read(zPattern, &zPattern);
-      }
-      while( c2 && c2!=']' ){
-        if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
-          c2 = sqlite3Utf8Read(zPattern, &zPattern);
-          if( c>=prior_c && c<=c2 ) seen = 1;
-          prior_c = 0;
-        }else{
-          if( c==c2 ){
-            seen = 1;
+    }
+    if( c==matchOther ){
+      if( pInfo->matchSet==0 ){
+        c = sqlite3Utf8Read(&zPattern);
+        if( c==0 ) return 0;
+        zEscaped = zPattern;
+      }else{
+        u32 prior_c = 0;
+        int seen = 0;
+        int invert = 0;
+        c = sqlite3Utf8Read(&zString);
+        if( c==0 ) return 0;
+        c2 = sqlite3Utf8Read(&zPattern);
+        if( c2=='^' ){
+          invert = 1;
+          c2 = sqlite3Utf8Read(&zPattern);
+        }
+        if( c2==']' ){
+          if( c==']' ) seen = 1;
+          c2 = sqlite3Utf8Read(&zPattern);
+        }
+        while( c2 && c2!=']' ){
+          if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
+            c2 = sqlite3Utf8Read(&zPattern);
+            if( c>=prior_c && c<=c2 ) seen = 1;
+            prior_c = 0;
+          }else{
+            if( c==c2 ){
+              seen = 1;
+            }
+            prior_c = c2;
           }
-          prior_c = c2;
+          c2 = sqlite3Utf8Read(&zPattern);
         }
-        c2 = sqlite3Utf8Read(zPattern, &zPattern);
-      }
-      if( c2==0 || (seen ^ invert)==0 ){
-        return 0;
-      }
-    }else if( esc==c && !prevEscape ){
-      prevEscape = 1;
-    }else{
-      c2 = sqlite3Utf8Read(zString, &zString);
-      if( noCase ){
-        GlogUpperToLower(c);
-        GlogUpperToLower(c2);
-      }
-      if( c!=c2 ){
-        return 0;
+        if( c2==0 || (seen ^ invert)==0 ){
+          return 0;
+        }
+        continue;
       }
-      prevEscape = 0;
     }
+    c2 = Utf8Read(zString);
+    if( c==c2 ) continue;
+    if( noCase  && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){
+      continue;
+    }
+    if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;
+    return 0;
   }
   return *zString==0;
 }
 
 /*
+** The sqlite3_strglob() interface.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlobPattern, const char *zString){
+  return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[')==0;
+}
+
+/*
+** The sqlite3_strlike() interface.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
+  return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc)==0;
+}
+
+/*
 ** Count the number of times that the LIKE operator (or GLOB which is
 ** just a variation of LIKE) gets called.  This is used for testing
 ** only.
@@ -85055,10 +103999,22 @@ static void likeFunc(
   sqlite3_value **argv
 ){
   const unsigned char *zA, *zB;
-  u32 escape = 0;
+  u32 escape;
   int nPat;
   sqlite3 *db = sqlite3_context_db_handle(context);
+  struct compareInfo *pInfo = sqlite3_user_data(context);
 
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
+   || sqlite3_value_type(argv[1])==SQLITE_BLOB
+  ){
+#ifdef SQLITE_TEST
+    sqlite3_like_count++;
+#endif
+    sqlite3_result_int(context, 0);
+    return;
+  }
+#endif
   zB = sqlite3_value_text(argv[0]);
   zA = sqlite3_value_text(argv[1]);
 
@@ -85085,14 +104041,14 @@ static void likeFunc(
           "ESCAPE expression must be a single character", -1);
       return;
     }
-    escape = sqlite3Utf8Read(zEsc, &zEsc);
+    escape = sqlite3Utf8Read(&zEsc);
+  }else{
+    escape = pInfo->matchSet;
   }
   if( zA && zB ){
-    struct compareInfo *pInfo = sqlite3_user_data(context);
 #ifdef SQLITE_TEST
     sqlite3_like_count++;
 #endif
-    
     sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
   }
 }
@@ -85214,10 +104170,6 @@ static const char hexdigits[] = {
 };
 
 /*
-** EXPERIMENTAL - This is not an official function.  The interface may
-** change.  This function may disappear.  Do not write code that depends
-** on this function.
-**
 ** Implementation of the QUOTE() function.  This function takes a single
 ** argument.  If the argument is numeric, the return value is the same as
 ** the argument.  If the argument is NULL, the return value is the string
@@ -85228,8 +104180,19 @@ static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
   assert( argc==1 );
   UNUSED_PARAMETER(argc);
   switch( sqlite3_value_type(argv[0]) ){
-    case SQLITE_INTEGER:
     case SQLITE_FLOAT: {
+      double r1, r2;
+      char zBuf[50];
+      r1 = sqlite3_value_double(argv[0]);
+      sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
+      sqlite3AtoF(zBuf, &r2, 20, SQLITE_UTF8);
+      if( r1!=r2 ){
+        sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.20e", r1);
+      }
+      sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+      break;
+    }
+    case SQLITE_INTEGER: {
       sqlite3_result_value(context, argv[0]);
       break;
     }
@@ -85286,6 +104249,62 @@ static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 }
 
 /*
+** The unicode() function.  Return the integer unicode code-point value
+** for the first character of the input string. 
+*/
+static void unicodeFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *z = sqlite3_value_text(argv[0]);
+  (void)argc;
+  if( z && z[0] ) sqlite3_result_int(context, sqlite3Utf8Read(&z));
+}
+
+/*
+** The char() function takes zero or more arguments, each of which is
+** an integer.  It constructs a string where each character of the string
+** is the unicode character for the corresponding integer argument.
+*/
+static void charFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  unsigned char *z, *zOut;
+  int i;
+  zOut = z = sqlite3_malloc64( argc*4+1 );
+  if( z==0 ){
+    sqlite3_result_error_nomem(context);
+    return;
+  }
+  for(i=0; i<argc; i++){
+    sqlite3_int64 x;
+    unsigned c;
+    x = sqlite3_value_int64(argv[i]);
+    if( x<0 || x>0x10ffff ) x = 0xfffd;
+    c = (unsigned)(x & 0x1fffff);
+    if( c<0x00080 ){
+      *zOut++ = (u8)(c&0xFF);
+    }else if( c<0x00800 ){
+      *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }else if( c<0x10000 ){
+      *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);
+      *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }else{
+      *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);
+      *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);
+      *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
+      *zOut++ = 0x80 + (u8)(c & 0x3F);
+    }                                                    \
+  }
+  sqlite3_result_text64(context, (char*)z, zOut-z, sqlite3_free, SQLITE_UTF8);
+}
+
+/*
 ** The hex() function.  Interpret the argument as a blob.  Return
 ** a hexadecimal rendering as text.
 */
@@ -85323,23 +104342,21 @@ static void zeroblobFunc(
   sqlite3_value **argv
 ){
   i64 n;
-  sqlite3 *db = sqlite3_context_db_handle(context);
+  int rc;
   assert( argc==1 );
   UNUSED_PARAMETER(argc);
   n = sqlite3_value_int64(argv[0]);
-  testcase( n==db->aLimit[SQLITE_LIMIT_LENGTH] );
-  testcase( n==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
-  if( n>db->aLimit[SQLITE_LIMIT_LENGTH] ){
-    sqlite3_result_error_toobig(context);
-  }else{
-    sqlite3_result_zeroblob(context, (int)n); /* IMP: R-00293-64994 */
+  if( n<0 ) n = 0;
+  rc = sqlite3_result_zeroblob64(context, n); /* IMP: R-00293-64994 */
+  if( rc ){
+    sqlite3_result_error_code(context, rc);
   }
 }
 
 /*
 ** The replace() function.  Three arguments are all strings: call
 ** them A, B, and C. The result is also a string which is derived
-** from A by replacing every occurance of B with C.  The match
+** from A by replacing every occurrence of B with C.  The match
 ** must be exact.  Collating sequences are not used.
 */
 static void replaceFunc(
@@ -85403,7 +104420,7 @@ static void replaceFunc(
         return;
       }
       zOld = zOut;
-      zOut = sqlite3_realloc(zOut, (int)nOut);
+      zOut = sqlite3_realloc64(zOut, (int)nOut);
       if( zOut==0 ){
         sqlite3_result_error_nomem(context);
         sqlite3_free(zOld);
@@ -85507,6 +104524,26 @@ static void trimFunc(
 }
 
 
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+/*
+** The "unknown" function is automatically substituted in place of
+** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
+** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.
+** When the "sqlite3" command-line shell is built using this functionality,
+** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
+** involving application-defined functions to be examined in a generic
+** sqlite3 shell.
+*/
+static void unknownFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  /* no-op */
+}
+#endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/
+
+
 /* IMP: R-25361-16150 This function is omitted from SQLite by default. It
 ** is only available if the SQLITE_SOUNDEX compile-time option is used
 ** when SQLite is built.
@@ -85577,6 +104614,14 @@ static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
   sqlite3 *db = sqlite3_context_db_handle(context);
   char *zErrMsg = 0;
 
+  /* Disallow the load_extension() SQL function unless the SQLITE_LoadExtFunc
+  ** flag is set.  See the sqlite3_enable_load_extension() API.
+  */
+  if( (db->flags & SQLITE_LoadExtFunc)==0 ){
+    sqlite3_result_error(context, "not authorized", -1);
+    return;
+  }
+
   if( argc==2 ){
     zProc = (const char *)sqlite3_value_text(argv[1]);
   }else{
@@ -85707,11 +104752,12 @@ static void minmaxStep(
   Mem *pBest;
   UNUSED_PARAMETER(NotUsed);
 
-  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
   pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
   if( !pBest ) return;
 
-  if( pBest->flags ){
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+    if( pBest->flags ) sqlite3SkipAccumulatorLoad(context);
+  }else if( pBest->flags ){
     int max;
     int cmp;
     CollSeq *pColl = sqlite3GetFuncCollSeq(context);
@@ -85727,8 +104773,11 @@ static void minmaxStep(
     cmp = sqlite3MemCompare(pBest, pArg, pColl);
     if( (max && cmp<0) || (!max && cmp>0) ){
       sqlite3VdbeMemCopy(pBest, pArg);
+    }else{
+      sqlite3SkipAccumulatorLoad(context);
     }
   }else{
+    pBest->db = sqlite3_context_db_handle(context);
     sqlite3VdbeMemCopy(pBest, pArg);
   }
 }
@@ -85736,7 +104785,7 @@ static void minMaxFinalize(sqlite3_context *context){
   sqlite3_value *pRes;
   pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
   if( pRes ){
-    if( ALWAYS(pRes->flags) ){
+    if( pRes->flags ){
       sqlite3_result_value(context, pRes);
     }
     sqlite3VdbeMemRelease(pRes);
@@ -85761,8 +104810,7 @@ static void groupConcatStep(
 
   if( pAccum ){
     sqlite3 *db = sqlite3_context_db_handle(context);
-    int firstTerm = pAccum->useMalloc==0;
-    pAccum->useMalloc = 2;
+    int firstTerm = pAccum->mxAlloc==0;
     pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
     if( !firstTerm ){
       if( argc==2 ){
@@ -85772,20 +104820,20 @@ static void groupConcatStep(
         zSep = ",";
         nSep = 1;
       }
-      sqlite3StrAccumAppend(pAccum, zSep, nSep);
+      if( nSep ) sqlite3StrAccumAppend(pAccum, zSep, nSep);
     }
     zVal = (char*)sqlite3_value_text(argv[0]);
     nVal = sqlite3_value_bytes(argv[0]);
-    sqlite3StrAccumAppend(pAccum, zVal, nVal);
+    if( zVal ) sqlite3StrAccumAppend(pAccum, zVal, nVal);
   }
 }
 static void groupConcatFinalize(sqlite3_context *context){
   StrAccum *pAccum;
   pAccum = sqlite3_aggregate_context(context, 0);
   if( pAccum ){
-    if( pAccum->tooBig ){
+    if( pAccum->accError==STRACCUM_TOOBIG ){
       sqlite3_result_error_toobig(context);
-    }else if( pAccum->mallocFailed ){
+    }else if( pAccum->accError==STRACCUM_NOMEM ){
       sqlite3_result_error_nomem(context);
     }else{    
       sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1, 
@@ -85799,11 +104847,11 @@ static void groupConcatFinalize(sqlite3_context *context){
 ** of the built-in functions above are part of the global function set.
 ** This routine only deals with those that are not global.
 */
-SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
+SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3 *db){
   int rc = sqlite3_overload_function(db, "MATCH", 2);
   assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
   if( rc==SQLITE_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
 }
 
@@ -85812,10 +104860,9 @@ SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
 */
 static void setLikeOptFlag(sqlite3 *db, const char *zName, u8 flagVal){
   FuncDef *pDef;
-  pDef = sqlite3FindFunction(db, zName, sqlite3Strlen30(zName),
-                             2, SQLITE_UTF8, 0);
+  pDef = sqlite3FindFunction(db, zName, 2, SQLITE_UTF8, 0);
   if( ALWAYS(pDef) ){
-    pDef->flags = flagVal;
+    pDef->funcFlags |= flagVal;
   }
 }
 
@@ -85846,6 +104893,11 @@ SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive)
 ** then set aWc[0] through aWc[2] to the wildcard characters and
 ** return TRUE.  If the function is not a LIKE-style function then
 ** return FALSE.
+**
+** *pIsNocase is set to true if uppercase and lowercase are equivalent for
+** the function (default for LIKE).  If the function makes the distinction
+** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to
+** false.
 */
 SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
   FuncDef *pDef;
@@ -85856,10 +104908,8 @@ SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocas
     return 0;
   }
   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-  pDef = sqlite3FindFunction(db, pExpr->u.zToken, 
-                             sqlite3Strlen30(pExpr->u.zToken),
-                             2, SQLITE_UTF8, 0);
-  if( NEVER(pDef==0) || (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
+  pDef = sqlite3FindFunction(db, pExpr->u.zToken, 2, SQLITE_UTF8, 0);
+  if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
     return 0;
   }
 
@@ -85871,18 +104921,18 @@ SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocas
   assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
   assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
   assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
-  *pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
+  *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
   return 1;
 }
 
 /*
-** All all of the FuncDef structures in the aBuiltinFunc[] array above
+** All of the FuncDef structures in the aBuiltinFunc[] array above
 ** to the global function hash table.  This occurs at start-time (as
 ** a consequence of calling sqlite3_initialize()).
 **
 ** After this routine runs
 */
-SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
+SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void){
   /*
   ** The following array holds FuncDef structures for all of the functions
   ** defined in this file.
@@ -85890,8 +104940,27 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
   ** The array cannot be constant since changes are made to the
   ** FuncDef.pHash elements at start-time.  The elements of this array
   ** are read-only after initialization is complete.
+  **
+  ** For peak efficiency, put the most frequently used function last.
   */
-  static SQLITE_WSD FuncDef aBuiltinFunc[] = {
+  static FuncDef aBuiltinFunc[] = {
+#ifdef SQLITE_SOUNDEX
+    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    VFUNCTION(load_extension,    1, 0, 0, loadExt          ),
+    VFUNCTION(load_extension,    2, 0, 0, loadExt          ),
+#endif
+#if SQLITE_USER_AUTHENTICATION
+    FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
+#endif
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+    DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
+    DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
+#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
+    FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
+    FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
+    FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
     FUNCTION(ltrim,              1, 1, 0, trimFunc         ),
     FUNCTION(ltrim,              2, 1, 0, trimFunc         ),
     FUNCTION(rtrim,              1, 2, 0, trimFunc         ),
@@ -85900,14 +104969,18 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
     FUNCTION(trim,               2, 3, 0, trimFunc         ),
     FUNCTION(min,               -1, 0, 1, minmaxFunc       ),
     FUNCTION(min,                0, 0, 1, 0                ),
-    AGGREGATE(min,               1, 0, 1, minmaxStep,      minMaxFinalize ),
+    AGGREGATE2(min,              1, 0, 1, minmaxStep,      minMaxFinalize,
+                                          SQLITE_FUNC_MINMAX ),
     FUNCTION(max,               -1, 1, 1, minmaxFunc       ),
     FUNCTION(max,                0, 1, 1, 0                ),
-    AGGREGATE(max,               1, 1, 1, minmaxStep,      minMaxFinalize ),
-    FUNCTION(typeof,             1, 0, 0, typeofFunc       ),
-    FUNCTION(length,             1, 0, 0, lengthFunc       ),
-    FUNCTION(substr,             2, 0, 0, substrFunc       ),
-    FUNCTION(substr,             3, 0, 0, substrFunc       ),
+    AGGREGATE2(max,              1, 1, 1, minmaxStep,      minMaxFinalize,
+                                          SQLITE_FUNC_MINMAX ),
+    FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
+    FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
+    FUNCTION(instr,              2, 0, 0, instrFunc        ),
+    FUNCTION(printf,            -1, 0, 0, printfFunc       ),
+    FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),
+    FUNCTION(char,              -1, 0, 0, charFunc         ),
     FUNCTION(abs,                1, 0, 0, absFunc          ),
 #ifndef SQLITE_OMIT_FLOATING_POINT
     FUNCTION(round,              1, 0, 0, roundFunc        ),
@@ -85915,66 +104988,70 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 #endif
     FUNCTION(upper,              1, 0, 0, upperFunc        ),
     FUNCTION(lower,              1, 0, 0, lowerFunc        ),
-    FUNCTION(coalesce,           1, 0, 0, 0                ),
-    FUNCTION(coalesce,           0, 0, 0, 0                ),
-/*  FUNCTION(coalesce,          -1, 0, 0, ifnullFunc       ), */
-    {-1,SQLITE_UTF8,SQLITE_FUNC_COALESCE,0,0,ifnullFunc,0,0,"coalesce",0,0},
     FUNCTION(hex,                1, 0, 0, hexFunc          ),
-/*  FUNCTION(ifnull,             2, 0, 0, ifnullFunc       ), */
-    {2,SQLITE_UTF8,SQLITE_FUNC_COALESCE,0,0,ifnullFunc,0,0,"ifnull",0,0},
-    FUNCTION(random,             0, 0, 0, randomFunc       ),
-    FUNCTION(randomblob,         1, 0, 0, randomBlob       ),
+    FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
+    VFUNCTION(random,            0, 0, 0, randomFunc       ),
+    VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
     FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
-    FUNCTION(sqlite_version,     0, 0, 0, versionFunc      ),
-    FUNCTION(sqlite_source_id,   0, 0, 0, sourceidFunc     ),
+    DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),
+    DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),
     FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
-#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
-    FUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
-    FUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
-#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
     FUNCTION(quote,              1, 0, 0, quoteFunc        ),
-    FUNCTION(last_insert_rowid,  0, 0, 0, last_insert_rowid),
-    FUNCTION(changes,            0, 0, 0, changes          ),
-    FUNCTION(total_changes,      0, 0, 0, total_changes    ),
+    VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
+    VFUNCTION(changes,           0, 0, 0, changes          ),
+    VFUNCTION(total_changes,     0, 0, 0, total_changes    ),
     FUNCTION(replace,            3, 0, 0, replaceFunc      ),
     FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
-  #ifdef SQLITE_SOUNDEX
-    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
-  #endif
-  #ifndef SQLITE_OMIT_LOAD_EXTENSION
-    FUNCTION(load_extension,     1, 0, 0, loadExt          ),
-    FUNCTION(load_extension,     2, 0, 0, loadExt          ),
-  #endif
+    FUNCTION(substr,             2, 0, 0, substrFunc       ),
+    FUNCTION(substr,             3, 0, 0, substrFunc       ),
     AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
     AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
     AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
- /* AGGREGATE(count,             0, 0, 0, countStep,       countFinalize  ), */
-    {0,SQLITE_UTF8,SQLITE_FUNC_COUNT,0,0,0,countStep,countFinalize,"count",0,0},
+    AGGREGATE2(count,            0, 0, 0, countStep,       countFinalize,
+               SQLITE_FUNC_COUNT  ),
     AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),
     AGGREGATE(group_concat,      1, 0, 0, groupConcatStep, groupConcatFinalize),
     AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
   
     LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #ifdef SQLITE_CASE_SENSITIVE_LIKE
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
     LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
     LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #else
+#else
     LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
     LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
-  #endif
+#endif
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+    FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),
+#endif
+    FUNCTION(coalesce,           1, 0, 0, 0                ),
+    FUNCTION(coalesce,           0, 0, 0, 0                ),
+    FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
   };
-
-  int i;
-  FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
-  FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aBuiltinFunc);
-
-  for(i=0; i<ArraySize(aBuiltinFunc); i++){
-    sqlite3FuncDefInsert(pHash, &aFunc[i]);
-  }
-  sqlite3RegisterDateTimeFunctions();
 #ifndef SQLITE_OMIT_ALTERTABLE
   sqlite3AlterFunctions();
 #endif
+#if defined(SQLITE_ENABLE_STAT3) || defined(SQLITE_ENABLE_STAT4)
+  sqlite3AnalyzeFunctions();
+#endif
+  sqlite3RegisterDateTimeFunctions();
+  sqlite3InsertBuiltinFuncs(aBuiltinFunc, ArraySize(aBuiltinFunc));
+
+#if 0  /* Enable to print out how the built-in functions are hashed */
+  {
+    int i;
+    FuncDef *p;
+    for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){
+      printf("FUNC-HASH %02d:", i);
+      for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash){
+        int n = sqlite3Strlen30(p->zName);
+        int h = p->zName[0] + n;
+        printf(" %s(%d)", p->zName, h);
+      }
+      printf("\n");
+    }
+  }
+#endif
 }
 
 /************** End of func.c ************************************************/
@@ -85992,6 +105069,7 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 ** This file contains code used by the compiler to add foreign key
 ** support to compiled SQL statements.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 #ifndef SQLITE_OMIT_TRIGGER
@@ -86001,8 +105079,9 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 ** --------------------------
 **
 ** Foreign keys in SQLite come in two flavours: deferred and immediate.
-** If an immediate foreign key constraint is violated, SQLITE_CONSTRAINT
-** is returned and the current statement transaction rolled back. If a 
+** If an immediate foreign key constraint is violated,
+** SQLITE_CONSTRAINT_FOREIGNKEY is returned and the current
+** statement transaction rolled back. If a 
 ** deferred foreign key constraint is violated, no action is taken 
 ** immediately. However if the application attempts to commit the 
 ** transaction before fixing the constraint violation, the attempt fails.
@@ -86066,7 +105145,8 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 ** Immediate constraints are usually handled similarly. The only difference 
 ** is that the counter used is stored as part of each individual statement
 ** object (struct Vdbe). If, after the statement has run, its immediate
-** constraint counter is greater than zero, it returns SQLITE_CONSTRAINT
+** constraint counter is greater than zero,
+** it returns SQLITE_CONSTRAINT_FOREIGNKEY
 ** and the statement transaction is rolled back. An exception is an INSERT
 ** statement that inserts a single row only (no triggers). In this case,
 ** instead of using a counter, an exception is thrown immediately if the
@@ -86122,7 +105202,7 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 ** A foreign key constraint requires that the key columns in the parent
 ** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
 ** Given that pParent is the parent table for foreign key constraint pFKey, 
-** search the schema a unique index on the parent key columns. 
+** search the schema for a unique index on the parent key columns. 
 **
 ** If successful, zero is returned. If the parent key is an INTEGER PRIMARY 
 ** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx 
@@ -86151,14 +105231,14 @@ SQLITE_PRIVATE void sqlite3RegisterGlobalFunctions(void){
 **
 **   4) No parent key columns were provided explicitly as part of the
 **      foreign key definition, and the PRIMARY KEY of the parent table 
-**      consists of a a different number of columns to the child key in 
+**      consists of a different number of columns to the child key in 
 **      the child table.
 **
 ** then non-zero is returned, and a "foreign key mismatch" error loaded
 ** into pParse. If an OOM error occurs, non-zero is returned and the
 ** pParse->db->mallocFailed flag is set.
 */
-static int locateFkeyIndex(
+SQLITE_PRIVATE int sqlite3FkLocateIndex(
   Parse *pParse,                  /* Parse context to store any error in */
   Table *pParent,                 /* Parent table of FK constraint pFKey */
   FKey *pFKey,                    /* Foreign key to find index for */
@@ -86197,13 +105277,13 @@ static int locateFkeyIndex(
     }
   }else if( paiCol ){
     assert( nCol>1 );
-    aiCol = (int *)sqlite3DbMallocRaw(pParse->db, nCol*sizeof(int));
+    aiCol = (int *)sqlite3DbMallocRawNN(pParse->db, nCol*sizeof(int));
     if( !aiCol ) return 1;
     *paiCol = aiCol;
   }
 
   for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){
-    if( pIdx->nColumn==nCol && pIdx->onError!=OE_None ){ 
+    if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) ){ 
       /* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
       ** of columns. If each indexed column corresponds to a foreign key
       ** column of pFKey, then this index is a winner.  */
@@ -86211,8 +105291,8 @@ static int locateFkeyIndex(
       if( zKey==0 ){
         /* If zKey is NULL, then this foreign key is implicitly mapped to 
         ** the PRIMARY KEY of table pParent. The PRIMARY KEY index may be 
-        ** identified by the test (Index.autoIndex==2).  */
-        if( pIdx->autoIndex==2 ){
+        ** identified by the test.  */
+        if( IsPrimaryKeyIndex(pIdx) ){
           if( aiCol ){
             int i;
             for(i=0; i<nCol; i++) aiCol[i] = pFKey->aCol[i].iFrom;
@@ -86226,17 +105306,17 @@ static int locateFkeyIndex(
         ** the default collation sequences for each column. */
         int i, j;
         for(i=0; i<nCol; i++){
-          int iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
-          char *zDfltColl;                  /* Def. collation for column */
+          i16 iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
+          const char *zDfltColl;            /* Def. collation for column */
           char *zIdxCol;                    /* Name of indexed column */
 
+          if( iCol<0 ) break; /* No foreign keys against expression indexes */
+
           /* If the index uses a collation sequence that is different from
           ** the default collation sequence for the column, this index is
           ** unusable. Bail out early in this case.  */
           zDfltColl = pParent->aCol[iCol].zColl;
-          if( !zDfltColl ){
-            zDfltColl = "BINARY";
-          }
+          if( !zDfltColl ) zDfltColl = sqlite3StrBINARY;
           if( sqlite3StrICmp(pIdx->azColl[i], zDfltColl) ) break;
 
           zIdxCol = pParent->aCol[iCol].zName;
@@ -86255,7 +105335,9 @@ static int locateFkeyIndex(
 
   if( !pIdx ){
     if( !pParse->disableTriggers ){
-      sqlite3ErrorMsg(pParse, "foreign key mismatch");
+      sqlite3ErrorMsg(pParse,
+           "foreign key mismatch - \"%w\" referencing \"%w\"",
+           pFKey->pFrom->zName, pFKey->zTo);
     }
     sqlite3DbFree(pParse->db, aiCol);
     return 1;
@@ -86316,10 +105398,11 @@ static void fkLookupParent(
   ** search for a matching row in the parent table.  */
   if( nIncr<0 ){
     sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, iOk);
+    VdbeCoverage(v);
   }
   for(i=0; i<pFKey->nCol; i++){
     int iReg = aiCol[i] + regData + 1;
-    sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk);
+    sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk); VdbeCoverage(v);
   }
 
   if( isIgnore==0 ){
@@ -86336,18 +105419,20 @@ static void fkLookupParent(
       ** will have INTEGER affinity applied to it, which may not be correct.  */
       sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[0]+1+regData, regTemp);
       iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0);
+      VdbeCoverage(v);
   
       /* If the parent table is the same as the child table, and we are about
       ** to increment the constraint-counter (i.e. this is an INSERT operation),
       ** then check if the row being inserted matches itself. If so, do not
       ** increment the constraint-counter.  */
       if( pTab==pFKey->pFrom && nIncr==1 ){
-        sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp);
+        sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp); VdbeCoverage(v);
+        sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
       }
   
       sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
-      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
+      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); VdbeCoverage(v);
+      sqlite3VdbeGoto(v, iOk);
       sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
       sqlite3VdbeJumpHere(v, iMustBeInt);
       sqlite3ReleaseTempReg(pParse, regTemp);
@@ -86355,10 +105440,9 @@ static void fkLookupParent(
       int nCol = pFKey->nCol;
       int regTemp = sqlite3GetTempRange(pParse, nCol);
       int regRec = sqlite3GetTempReg(pParse);
-      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
   
       sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);
-      sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF);
+      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
       for(i=0; i<nCol; i++){
         sqlite3VdbeAddOp2(v, OP_Copy, aiCol[i]+1+regData, regTemp+i);
       }
@@ -86378,38 +105462,41 @@ static void fkLookupParent(
         for(i=0; i<nCol; i++){
           int iChild = aiCol[i]+1+regData;
           int iParent = pIdx->aiColumn[i]+1+regData;
+          assert( pIdx->aiColumn[i]>=0 );
           assert( aiCol[i]!=pTab->iPKey );
           if( pIdx->aiColumn[i]==pTab->iPKey ){
             /* The parent key is a composite key that includes the IPK column */
             iParent = regData;
           }
-          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent);
+          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
           sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
         }
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk);
+        sqlite3VdbeGoto(v, iOk);
       }
   
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regTemp, nCol, regRec);
-      sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v,pIdx), P4_TRANSIENT);
-      sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0);
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, regTemp, nCol, regRec,
+                        sqlite3IndexAffinityStr(pParse->db,pIdx), nCol);
+      sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); VdbeCoverage(v);
   
       sqlite3ReleaseTempReg(pParse, regRec);
       sqlite3ReleaseTempRange(pParse, regTemp, nCol);
     }
   }
 
-  if( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){
+  if( !pFKey->isDeferred && !(pParse->db->flags & SQLITE_DeferFKs)
+   && !pParse->pToplevel 
+   && !pParse->isMultiWrite 
+  ){
     /* Special case: If this is an INSERT statement that will insert exactly
     ** one row into the table, raise a constraint immediately instead of
     ** incrementing a counter. This is necessary as the VM code is being
     ** generated for will not open a statement transaction.  */
     assert( nIncr==1 );
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
-    );
+    sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
+        OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
   }else{
     if( nIncr>0 && pFKey->isDeferred==0 ){
-      sqlite3ParseToplevel(pParse)->mayAbort = 1;
+      sqlite3MayAbort(pParse);
     }
     sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
   }
@@ -86418,6 +105505,62 @@ static void fkLookupParent(
   sqlite3VdbeAddOp1(v, OP_Close, iCur);
 }
 
+
+/*
+** Return an Expr object that refers to a memory register corresponding
+** to column iCol of table pTab.
+**
+** regBase is the first of an array of register that contains the data
+** for pTab.  regBase itself holds the rowid.  regBase+1 holds the first
+** column.  regBase+2 holds the second column, and so forth.
+*/
+static Expr *exprTableRegister(
+  Parse *pParse,     /* Parsing and code generating context */
+  Table *pTab,       /* The table whose content is at r[regBase]... */
+  int regBase,       /* Contents of table pTab */
+  i16 iCol           /* Which column of pTab is desired */
+){
+  Expr *pExpr;
+  Column *pCol;
+  const char *zColl;
+  sqlite3 *db = pParse->db;
+
+  pExpr = sqlite3Expr(db, TK_REGISTER, 0);
+  if( pExpr ){
+    if( iCol>=0 && iCol!=pTab->iPKey ){
+      pCol = &pTab->aCol[iCol];
+      pExpr->iTable = regBase + iCol + 1;
+      pExpr->affinity = pCol->affinity;
+      zColl = pCol->zColl;
+      if( zColl==0 ) zColl = db->pDfltColl->zName;
+      pExpr = sqlite3ExprAddCollateString(pParse, pExpr, zColl);
+    }else{
+      pExpr->iTable = regBase;
+      pExpr->affinity = SQLITE_AFF_INTEGER;
+    }
+  }
+  return pExpr;
+}
+
+/*
+** Return an Expr object that refers to column iCol of table pTab which
+** has cursor iCur.
+*/
+static Expr *exprTableColumn(
+  sqlite3 *db,      /* The database connection */
+  Table *pTab,      /* The table whose column is desired */
+  int iCursor,      /* The open cursor on the table */
+  i16 iCol          /* The column that is wanted */
+){
+  Expr *pExpr = sqlite3Expr(db, TK_COLUMN, 0);
+  if( pExpr ){
+    pExpr->pTab = pTab;
+    pExpr->iTable = iCursor;
+    pExpr->iColumn = iCol;
+  }
+  return pExpr;
+}
+
 /*
 ** This function is called to generate code executed when a row is deleted
 ** from the parent table of foreign key constraint pFKey and, if pFKey is 
@@ -86425,6 +105568,10 @@ static void fkLookupParent(
 ** code for an SQL UPDATE operation, this function may be called twice -
 ** once to "delete" the old row and once to "insert" the new row.
 **
+** Parameter nIncr is passed -1 when inserting a row (as this may decrease
+** the number of FK violations in the db) or +1 when deleting one (as this
+** may increase the number of FK constraint problems).
+**
 ** The code generated by this function scans through the rows in the child
 ** table that correspond to the parent table row being deleted or inserted.
 ** For each child row found, one of the following actions is taken:
@@ -86433,13 +105580,13 @@ static void fkLookupParent(
 **   --------------------------------------------------------------------------
 **   DELETE      immediate   Increment the "immediate constraint counter".
 **                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,
-**                           throw a "foreign key constraint failed" exception.
+**                           throw a "FOREIGN KEY constraint failed" exception.
 **
 **   INSERT      immediate   Decrement the "immediate constraint counter".
 **
 **   DELETE      deferred    Increment the "deferred constraint counter".
 **                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,
-**                           throw a "foreign key constraint failed" exception.
+**                           throw a "FOREIGN KEY constraint failed" exception.
 **
 **   INSERT      deferred    Decrement the "deferred constraint counter".
 **
@@ -86448,12 +105595,12 @@ static void fkLookupParent(
 */
 static void fkScanChildren(
   Parse *pParse,                  /* Parse context */
-  SrcList *pSrc,                  /* SrcList containing the table to scan */
-  Table *pTab,
-  Index *pIdx,                    /* Foreign key index */
-  FKey *pFKey,                    /* Foreign key relationship */
+  SrcList *pSrc,                  /* The child table to be scanned */
+  Table *pTab,                    /* The parent table */
+  Index *pIdx,                    /* Index on parent covering the foreign key */
+  FKey *pFKey,                    /* The foreign key linking pSrc to pTab */
   int *aiCol,                     /* Map from pIdx cols to child table cols */
-  int regData,                    /* Referenced table data starts here */
+  int regData,                    /* Parent row data starts here */
   int nIncr                       /* Amount to increment deferred counter by */
 ){
   sqlite3 *db = pParse->db;       /* Database handle */
@@ -86464,10 +105611,14 @@ static void fkScanChildren(
   int iFkIfZero = 0;              /* Address of OP_FkIfZero */
   Vdbe *v = sqlite3GetVdbe(pParse);
 
-  assert( !pIdx || pIdx->pTable==pTab );
+  assert( pIdx==0 || pIdx->pTable==pTab );
+  assert( pIdx==0 || pIdx->nKeyCol==pFKey->nCol );
+  assert( pIdx!=0 || pFKey->nCol==1 );
+  assert( pIdx!=0 || HasRowid(pTab) );
 
   if( nIncr<0 ){
     iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, 0);
+    VdbeCoverage(v);
   }
 
   /* Create an Expr object representing an SQL expression like:
@@ -86482,26 +105633,11 @@ static void fkScanChildren(
     Expr *pLeft;                  /* Value from parent table row */
     Expr *pRight;                 /* Column ref to child table */
     Expr *pEq;                    /* Expression (pLeft = pRight) */
-    int iCol;                     /* Index of column in child table */ 
+    i16 iCol;                     /* Index of column in child table */ 
     const char *zCol;             /* Name of column in child table */
 
-    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
-    if( pLeft ){
-      /* Set the collation sequence and affinity of the LHS of each TK_EQ
-      ** expression to the parent key column defaults.  */
-      if( pIdx ){
-        Column *pCol;
-        iCol = pIdx->aiColumn[i];
-        pCol = &pTab->aCol[iCol];
-        if( pTab->iPKey==iCol ) iCol = -1;
-        pLeft->iTable = regData+iCol+1;
-        pLeft->affinity = pCol->affinity;
-        pLeft->pColl = sqlite3LocateCollSeq(pParse, pCol->zColl);
-      }else{
-        pLeft->iTable = regData;
-        pLeft->affinity = SQLITE_AFF_INTEGER;
-      }
-    }
+    iCol = pIdx ? pIdx->aiColumn[i] : -1;
+    pLeft = exprTableRegister(pParse, pTab, regData, iCol);
     iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
     assert( iCol>=0 );
     zCol = pFKey->pFrom->aCol[iCol].zName;
@@ -86510,24 +105646,40 @@ static void fkScanChildren(
     pWhere = sqlite3ExprAnd(db, pWhere, pEq);
   }
 
-  /* If the child table is the same as the parent table, and this scan
-  ** is taking place as part of a DELETE operation (operation D.2), omit the
-  ** row being deleted from the scan by adding ($rowid != rowid) to the WHERE 
-  ** clause, where $rowid is the rowid of the row being deleted.  */
+  /* If the child table is the same as the parent table, then add terms
+  ** to the WHERE clause that prevent this entry from being scanned.
+  ** The added WHERE clause terms are like this:
+  **
+  **     $current_rowid!=rowid
+  **     NOT( $current_a==a AND $current_b==b AND ... )
+  **
+  ** The first form is used for rowid tables.  The second form is used
+  ** for WITHOUT ROWID tables.  In the second form, the primary key is
+  ** (a,b,...)
+  */
   if( pTab==pFKey->pFrom && nIncr>0 ){
-    Expr *pEq;                    /* Expression (pLeft = pRight) */
+    Expr *pNe;                    /* Expression (pLeft != pRight) */
     Expr *pLeft;                  /* Value from parent table row */
     Expr *pRight;                 /* Column ref to child table */
-    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
-    pRight = sqlite3Expr(db, TK_COLUMN, 0);
-    if( pLeft && pRight ){
-      pLeft->iTable = regData;
-      pLeft->affinity = SQLITE_AFF_INTEGER;
-      pRight->iTable = pSrc->a[0].iCursor;
-      pRight->iColumn = -1;
-    }
-    pEq = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
-    pWhere = sqlite3ExprAnd(db, pWhere, pEq);
+    if( HasRowid(pTab) ){
+      pLeft = exprTableRegister(pParse, pTab, regData, -1);
+      pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);
+      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
+    }else{
+      Expr *pEq, *pAll = 0;
+      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+      assert( pIdx!=0 );
+      for(i=0; i<pPk->nKeyCol; i++){
+        i16 iCol = pIdx->aiColumn[i];
+        assert( iCol>=0 );
+        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
+        pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, iCol);
+        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
+        pAll = sqlite3ExprAnd(db, pAll, pEq);
+      }
+      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0, 0);
+    }
+    pWhere = sqlite3ExprAnd(db, pWhere, pNe);
   }
 
   /* Resolve the references in the WHERE clause. */
@@ -86537,13 +105689,9 @@ static void fkScanChildren(
   sqlite3ResolveExprNames(&sNameContext, pWhere);
 
   /* Create VDBE to loop through the entries in pSrc that match the WHERE
-  ** clause. If the constraint is not deferred, throw an exception for
-  ** each row found. Otherwise, for deferred constraints, increment the
-  ** deferred constraint counter by nIncr for each row selected.  */
-  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0);
-  if( nIncr>0 && pFKey->isDeferred==0 ){
-    sqlite3ParseToplevel(pParse)->mayAbort = 1;
-  }
+  ** clause. For each row found, increment either the deferred or immediate
+  ** foreign key constraint counter. */
+  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
   sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
   if( pWInfo ){
     sqlite3WhereEnd(pWInfo);
@@ -86557,8 +105705,8 @@ static void fkScanChildren(
 }
 
 /*
-** This function returns a pointer to the head of a linked list of FK
-** constraints for which table pTab is the parent table. For example,
+** This function returns a linked list of FKey objects (connected by
+** FKey.pNextTo) holding all children of table pTab.  For example,
 ** given the following schema:
 **
 **   CREATE TABLE t1(a PRIMARY KEY);
@@ -86571,8 +105719,7 @@ static void fkScanChildren(
 ** table).
 */
 SQLITE_PRIVATE FKey *sqlite3FkReferences(Table *pTab){
-  int nName = sqlite3Strlen30(pTab->zName);
-  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName, nName);
+  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName);
 }
 
 /*
@@ -86626,11 +105773,11 @@ SQLITE_PRIVATE void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTa
       ** when this statement is run.  */
       FKey *p;
       for(p=pTab->pFKey; p; p=p->pNextFrom){
-        if( p->isDeferred ) break;
+        if( p->isDeferred || (db->flags & SQLITE_DeferFKs) ) break;
       }
       if( !p ) return;
       iSkip = sqlite3VdbeMakeLabel(v);
-      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip);
+      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
     }
 
     pParse->disableTriggers = 1;
@@ -86640,11 +105787,18 @@ SQLITE_PRIVATE void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTa
     /* If the DELETE has generated immediate foreign key constraint 
     ** violations, halt the VDBE and return an error at this point, before
     ** any modifications to the schema are made. This is because statement
-    ** transactions are not able to rollback schema changes.  */
-    sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
-    sqlite3HaltConstraint(
-        pParse, OE_Abort, "foreign key constraint failed", P4_STATIC
-    );
+    ** transactions are not able to rollback schema changes.  
+    **
+    ** If the SQLITE_DeferFKs flag is set, then this is not required, as
+    ** the statement transaction will not be rolled back even if FK
+    ** constraints are violated.
+    */
+    if( (db->flags & SQLITE_DeferFKs)==0 ){
+      sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
+      VdbeCoverage(v);
+      sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
+          OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
+    }
 
     if( iSkip ){
       sqlite3VdbeResolveLabel(v, iSkip);
@@ -86652,6 +105806,88 @@ SQLITE_PRIVATE void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTa
   }
 }
 
+
+/*
+** The second argument points to an FKey object representing a foreign key
+** for which pTab is the child table. An UPDATE statement against pTab
+** is currently being processed. For each column of the table that is 
+** actually updated, the corresponding element in the aChange[] array
+** is zero or greater (if a column is unmodified the corresponding element
+** is set to -1). If the rowid column is modified by the UPDATE statement
+** the bChngRowid argument is non-zero.
+**
+** This function returns true if any of the columns that are part of the
+** child key for FK constraint *p are modified.
+*/
+static int fkChildIsModified(
+  Table *pTab,                    /* Table being updated */
+  FKey *p,                        /* Foreign key for which pTab is the child */
+  int *aChange,                   /* Array indicating modified columns */
+  int bChngRowid                  /* True if rowid is modified by this update */
+){
+  int i;
+  for(i=0; i<p->nCol; i++){
+    int iChildKey = p->aCol[i].iFrom;
+    if( aChange[iChildKey]>=0 ) return 1;
+    if( iChildKey==pTab->iPKey && bChngRowid ) return 1;
+  }
+  return 0;
+}
+
+/*
+** The second argument points to an FKey object representing a foreign key
+** for which pTab is the parent table. An UPDATE statement against pTab
+** is currently being processed. For each column of the table that is 
+** actually updated, the corresponding element in the aChange[] array
+** is zero or greater (if a column is unmodified the corresponding element
+** is set to -1). If the rowid column is modified by the UPDATE statement
+** the bChngRowid argument is non-zero.
+**
+** This function returns true if any of the columns that are part of the
+** parent key for FK constraint *p are modified.
+*/
+static int fkParentIsModified(
+  Table *pTab, 
+  FKey *p, 
+  int *aChange, 
+  int bChngRowid
+){
+  int i;
+  for(i=0; i<p->nCol; i++){
+    char *zKey = p->aCol[i].zCol;
+    int iKey;
+    for(iKey=0; iKey<pTab->nCol; iKey++){
+      if( aChange[iKey]>=0 || (iKey==pTab->iPKey && bChngRowid) ){
+        Column *pCol = &pTab->aCol[iKey];
+        if( zKey ){
+          if( 0==sqlite3StrICmp(pCol->zName, zKey) ) return 1;
+        }else if( pCol->colFlags & COLFLAG_PRIMKEY ){
+          return 1;
+        }
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Return true if the parser passed as the first argument is being
+** used to code a trigger that is really a "SET NULL" action belonging
+** to trigger pFKey.
+*/
+static int isSetNullAction(Parse *pParse, FKey *pFKey){
+  Parse *pTop = sqlite3ParseToplevel(pParse);
+  if( pTop->pTriggerPrg ){
+    Trigger *p = pTop->pTriggerPrg->pTrigger;
+    if( (p==pFKey->apTrigger[0] && pFKey->aAction[0]==OE_SetNull)
+     || (p==pFKey->apTrigger[1] && pFKey->aAction[1]==OE_SetNull)
+    ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
 /*
 ** This function is called when inserting, deleting or updating a row of
 ** table pTab to generate VDBE code to perform foreign key constraint 
@@ -86676,7 +105912,9 @@ SQLITE_PRIVATE void sqlite3FkCheck(
   Parse *pParse,                  /* Parse context */
   Table *pTab,                    /* Row is being deleted from this table */ 
   int regOld,                     /* Previous row data is stored here */
-  int regNew                      /* New row data is stored here */
+  int regNew,                     /* New row data is stored here */
+  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
+  int bChngRowid                  /* True if rowid is UPDATEd */
 ){
   sqlite3 *db = pParse->db;       /* Database handle */
   FKey *pFKey;                    /* Used to iterate through FKs */
@@ -86702,7 +105940,14 @@ SQLITE_PRIVATE void sqlite3FkCheck(
     int *aiCol;
     int iCol;
     int i;
-    int isIgnore = 0;
+    int bIgnore = 0;
+
+    if( aChange 
+     && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
+     && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 
+    ){
+      continue;
+    }
 
     /* Find the parent table of this foreign key. Also find a unique index 
     ** on the parent key columns in the parent table. If either of these 
@@ -86713,7 +105958,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
     }else{
       pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
     }
-    if( !pTo || locateFkeyIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
+    if( !pTo || sqlite3FkLocateIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
       assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );
       if( !isIgnoreErrors || db->mallocFailed ) return;
       if( pTo==0 ){
@@ -86728,7 +105973,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
         int iJump = sqlite3VdbeCurrentAddr(v) + pFKey->nCol + 1;
         for(i=0; i<pFKey->nCol; i++){
           int iReg = pFKey->aCol[i].iFrom + regOld + 1;
-          sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iJump);
+          sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iJump); VdbeCoverage(v);
         }
         sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, -1);
       }
@@ -86746,6 +105991,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
       if( aiCol[i]==pTab->iPKey ){
         aiCol[i] = -1;
       }
+      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
 #ifndef SQLITE_OMIT_AUTHORIZATION
       /* Request permission to read the parent key columns. If the 
       ** authorization callback returns SQLITE_IGNORE, behave as if any
@@ -86754,7 +106000,7 @@ SQLITE_PRIVATE void sqlite3FkCheck(
         int rcauth;
         char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
         rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
-        isIgnore = (rcauth==SQLITE_IGNORE);
+        bIgnore = (rcauth==SQLITE_IGNORE);
       }
 #endif
     }
@@ -86769,39 +106015,51 @@ SQLITE_PRIVATE void sqlite3FkCheck(
       /* A row is being removed from the child table. Search for the parent.
       ** If the parent does not exist, removing the child row resolves an 
       ** outstanding foreign key constraint violation. */
-      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1,isIgnore);
+      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);
     }
-    if( regNew!=0 ){
+    if( regNew!=0 && !isSetNullAction(pParse, pFKey) ){
       /* A row is being added to the child table. If a parent row cannot
-      ** be found, adding the child row has violated the FK constraint. */ 
-      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1,isIgnore);
+      ** be found, adding the child row has violated the FK constraint. 
+      **
+      ** If this operation is being performed as part of a trigger program
+      ** that is actually a "SET NULL" action belonging to this very 
+      ** foreign key, then omit this scan altogether. As all child key
+      ** values are guaranteed to be NULL, it is not possible for adding
+      ** this row to cause an FK violation.  */
+      fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1, bIgnore);
     }
 
     sqlite3DbFree(db, aiFree);
   }
 
-  /* Loop through all the foreign key constraints that refer to this table */
+  /* Loop through all the foreign key constraints that refer to this table.
+  ** (the "child" constraints) */
   for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
     Index *pIdx = 0;              /* Foreign key index for pFKey */
     SrcList *pSrc;
     int *aiCol = 0;
 
-    if( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){
+    if( aChange && fkParentIsModified(pTab, pFKey, aChange, bChngRowid)==0 ){
+      continue;
+    }
+
+    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
+     && !pParse->pToplevel && !pParse->isMultiWrite 
+    ){
       assert( regOld==0 && regNew!=0 );
-      /* Inserting a single row into a parent table cannot cause an immediate
-      ** foreign key violation. So do nothing in this case.  */
+      /* Inserting a single row into a parent table cannot cause (or fix)
+      ** an immediate foreign key violation. So do nothing in this case.  */
       continue;
     }
 
-    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
+    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
       if( !isIgnoreErrors || db->mallocFailed ) return;
       continue;
     }
     assert( aiCol || pFKey->nCol==1 );
 
-    /* Create a SrcList structure containing a single table (the table 
-    ** the foreign key that refers to this table is attached to). This
-    ** is required for the sqlite3WhereXXX() interface.  */
+    /* Create a SrcList structure containing the child table.  We need the
+    ** child table as a SrcList for sqlite3WhereBegin() */
     pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
     if( pSrc ){
       struct SrcList_item *pItem = pSrc->a;
@@ -86814,13 +106072,28 @@ SQLITE_PRIVATE void sqlite3FkCheck(
         fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
       }
       if( regOld!=0 ){
-        /* If there is a RESTRICT action configured for the current operation
-        ** on the parent table of this FK, then throw an exception 
-        ** immediately if the FK constraint is violated, even if this is a
-        ** deferred trigger. That's what RESTRICT means. To defer checking
-        ** the constraint, the FK should specify NO ACTION (represented
-        ** using OE_None). NO ACTION is the default.  */
+        int eAction = pFKey->aAction[aChange!=0];
         fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);
+        /* If this is a deferred FK constraint, or a CASCADE or SET NULL
+        ** action applies, then any foreign key violations caused by
+        ** removing the parent key will be rectified by the action trigger.
+        ** So do not set the "may-abort" flag in this case.
+        **
+        ** Note 1: If the FK is declared "ON UPDATE CASCADE", then the
+        ** may-abort flag will eventually be set on this statement anyway
+        ** (when this function is called as part of processing the UPDATE
+        ** within the action trigger).
+        **
+        ** Note 2: At first glance it may seem like SQLite could simply omit
+        ** all OP_FkCounter related scans when either CASCADE or SET NULL
+        ** applies. The trouble starts if the CASCADE or SET NULL action 
+        ** trigger causes other triggers or action rules attached to the 
+        ** child table to fire. In these cases the fk constraint counters
+        ** might be set incorrectly if any OP_FkCounter related scans are 
+        ** omitted.  */
+        if( !pFKey->isDeferred && eAction!=OE_Cascade && eAction!=OE_SetNull ){
+          sqlite3MayAbort(pParse);
+        }
       }
       pItem->zName = 0;
       sqlite3SrcListDelete(db, pSrc);
@@ -86848,15 +106121,19 @@ SQLITE_PRIVATE u32 sqlite3FkOldmask(
     }
     for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
       Index *pIdx = 0;
-      locateFkeyIndex(pParse, pTab, p, &pIdx, 0);
+      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
       if( pIdx ){
-        for(i=0; i<pIdx->nColumn; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
+        for(i=0; i<pIdx->nKeyCol; i++){
+          assert( pIdx->aiColumn[i]>=0 );
+          mask |= COLUMN_MASK(pIdx->aiColumn[i]);
+        }
       }
     }
   }
   return mask;
 }
 
+
 /*
 ** This function is called before generating code to update or delete a 
 ** row contained in table pTab. If the operation is a DELETE, then
@@ -86886,31 +106163,16 @@ SQLITE_PRIVATE int sqlite3FkRequired(
     }else{
       /* This is an UPDATE. Foreign key processing is only required if the
       ** operation modifies one or more child or parent key columns. */
-      int i;
       FKey *p;
 
       /* Check if any child key columns are being modified. */
       for(p=pTab->pFKey; p; p=p->pNextFrom){
-        for(i=0; i<p->nCol; i++){
-          int iChildKey = p->aCol[i].iFrom;
-          if( aChange[iChildKey]>=0 ) return 1;
-          if( iChildKey==pTab->iPKey && chngRowid ) return 1;
-        }
+        if( fkChildIsModified(pTab, p, aChange, chngRowid) ) return 1;
       }
 
       /* Check if any parent key columns are being modified. */
       for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
-        for(i=0; i<p->nCol; i++){
-          char *zKey = p->aCol[i].zCol;
-          int iKey;
-          for(iKey=0; iKey<pTab->nCol; iKey++){
-            Column *pCol = &pTab->aCol[iKey];
-            if( (zKey ? !sqlite3StrICmp(pCol->zName, zKey) : pCol->isPrimKey) ){
-              if( aChange[iKey]>=0 ) return 1;
-              if( iKey==pTab->iPKey && chngRowid ) return 1;
-            }
-          }
-        }
+        if( fkParentIsModified(pTab, p, aChange, chngRowid) ) return 1;
       }
     }
   }
@@ -86958,10 +106220,12 @@ static Trigger *fkActionTrigger(
   int iAction = (pChanges!=0);    /* 1 for UPDATE, 0 for DELETE */
 
   action = pFKey->aAction[iAction];
+  if( action==OE_Restrict && (db->flags & SQLITE_DeferFKs) ){
+    return 0;
+  }
   pTrigger = pFKey->apTrigger[iAction];
 
   if( action!=OE_None && !pTrigger ){
-    u8 enableLookaside;           /* Copy of db->lookaside.bEnabled */
     char const *zFrom;            /* Name of child table */
     int nFrom;                    /* Length in bytes of zFrom */
     Index *pIdx = 0;              /* Parent key index for this FK */
@@ -86973,7 +106237,7 @@ static Trigger *fkActionTrigger(
     int i;                        /* Iterator variable */
     Expr *pWhen = 0;              /* WHEN clause for the trigger */
 
-    if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
+    if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
     assert( aiCol || pFKey->nCol==1 );
 
     for(i=0; i<pFKey->nCol; i++){
@@ -86986,11 +106250,11 @@ static Trigger *fkActionTrigger(
 
       iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
       assert( iFromCol>=0 );
-      tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
-      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;
-
-      tToCol.n = sqlite3Strlen30(tToCol.z);
-      tFromCol.n = sqlite3Strlen30(tFromCol.z);
+      assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );
+      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
+      sqlite3TokenInit(&tToCol,
+                   pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName);
+      sqlite3TokenInit(&tFromCol, pFKey->pFrom->aCol[iFromCol].zName);
 
       /* Create the expression "OLD.zToCol = zFromCol". It is important
       ** that the "OLD.zToCol" term is on the LHS of the = operator, so
@@ -86998,10 +106262,10 @@ static Trigger *fkActionTrigger(
       ** parent table are used for the comparison. */
       pEq = sqlite3PExpr(pParse, TK_EQ,
           sqlite3PExpr(pParse, TK_DOT, 
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
+            sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
+            sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)
           , 0),
-          sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol)
+          sqlite3ExprAlloc(db, TK_ID, &tFromCol, 0)
       , 0);
       pWhere = sqlite3ExprAnd(db, pWhere, pEq);
 
@@ -87013,12 +106277,12 @@ static Trigger *fkActionTrigger(
       if( pChanges ){
         pEq = sqlite3PExpr(pParse, TK_IS,
             sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
+              sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
+              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0),
               0),
             sqlite3PExpr(pParse, TK_DOT, 
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
-              sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol),
+              sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
+              sqlite3ExprAlloc(db, TK_ID, &tToCol, 0),
               0),
             0);
         pWhen = sqlite3ExprAnd(db, pWhen, pEq);
@@ -87028,8 +106292,8 @@ static Trigger *fkActionTrigger(
         Expr *pNew;
         if( action==OE_Cascade ){
           pNew = sqlite3PExpr(pParse, TK_DOT, 
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tNew),
-            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
+            sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
+            sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)
           , 0);
         }else if( action==OE_SetDflt ){
           Expr *pDflt = pFKey->pFrom->aCol[iFromCol].pDflt;
@@ -87056,7 +106320,7 @@ static Trigger *fkActionTrigger(
 
       tFrom.z = zFrom;
       tFrom.n = nFrom;
-      pRaise = sqlite3Expr(db, TK_RAISE, "foreign key constraint failed");
+      pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");
       if( pRaise ){
         pRaise->affinity = OE_Abort;
       }
@@ -87070,19 +106334,17 @@ static Trigger *fkActionTrigger(
     }
 
     /* Disable lookaside memory allocation */
-    enableLookaside = db->lookaside.bEnabled;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.bDisable++;
 
     pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
         sizeof(Trigger) +         /* struct Trigger */
         sizeof(TriggerStep) +     /* Single step in trigger program */
-        nFrom + 1                 /* Space for pStep->target.z */
+        nFrom + 1                 /* Space for pStep->zTarget */
     );
     if( pTrigger ){
       pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
-      pStep->target.z = (char *)&pStep[1];
-      pStep->target.n = nFrom;
-      memcpy((char *)pStep->target.z, zFrom, nFrom);
+      pStep->zTarget = (char *)&pStep[1];
+      memcpy((char *)pStep->zTarget, zFrom, nFrom);
   
       pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
       pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
@@ -87094,7 +106356,7 @@ static Trigger *fkActionTrigger(
     }
 
     /* Re-enable the lookaside buffer, if it was disabled earlier. */
-    db->lookaside.bEnabled = enableLookaside;
+    db->lookaside.bDisable--;
 
     sqlite3ExprDelete(db, pWhere);
     sqlite3ExprDelete(db, pWhen);
@@ -87136,7 +106398,9 @@ SQLITE_PRIVATE void sqlite3FkActions(
   Parse *pParse,                  /* Parse context */
   Table *pTab,                    /* Table being updated or deleted from */
   ExprList *pChanges,             /* Change-list for UPDATE, NULL for DELETE */
-  int regOld                      /* Address of array containing old row */
+  int regOld,                     /* Address of array containing old row */
+  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
+  int bChngRowid                  /* True if rowid is UPDATEd */
 ){
   /* If foreign-key support is enabled, iterate through all FKs that 
   ** refer to table pTab. If there is an action associated with the FK 
@@ -87145,9 +106409,11 @@ SQLITE_PRIVATE void sqlite3FkActions(
   if( pParse->db->flags&SQLITE_ForeignKeys ){
     FKey *pFKey;                  /* Iterator variable */
     for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
-      Trigger *pAction = fkActionTrigger(pParse, pTab, pFKey, pChanges);
-      if( pAction ){
-        sqlite3CodeRowTriggerDirect(pParse, pAction, pTab, regOld, OE_Abort, 0);
+      if( aChange==0 || fkParentIsModified(pTab, pFKey, aChange, bChngRowid) ){
+        Trigger *pAct = fkActionTrigger(pParse, pTab, pFKey, pChanges);
+        if( pAct ){
+          sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);
+        }
       }
     }
   }
@@ -87164,7 +106430,8 @@ SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
   FKey *pFKey;                    /* Iterator variable */
   FKey *pNext;                    /* Copy of pFKey->pNextFrom */
 
-  assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
+  assert( db==0 || IsVirtual(pTab)
+         || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
   for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){
 
     /* Remove the FK from the fkeyHash hash table. */
@@ -87174,7 +106441,7 @@ SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
       }else{
         void *p = (void *)pFKey->pNextTo;
         const char *z = (p ? pFKey->pNextTo->zTo : pFKey->zTo);
-        sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, sqlite3Strlen30(z), p);
+        sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, p);
       }
       if( pFKey->pNextTo ){
         pFKey->pNextTo->pPrevTo = pFKey->pPrevTo;
@@ -87214,25 +106481,41 @@ SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
 ** This file contains C code routines that are called by the parser
 ** to handle INSERT statements in SQLite.
 */
+/* #include "sqliteInt.h" */
 
 /*
-** Generate code that will open a table for reading.
+** Generate code that will 
+**
+**   (1) acquire a lock for table pTab then
+**   (2) open pTab as cursor iCur.
+**
+** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
+** for that table that is actually opened.
 */
 SQLITE_PRIVATE void sqlite3OpenTable(
-  Parse *p,       /* Generate code into this VDBE */
+  Parse *pParse,  /* Generate code into this VDBE */
   int iCur,       /* The cursor number of the table */
   int iDb,        /* The database index in sqlite3.aDb[] */
   Table *pTab,    /* The table to be opened */
   int opcode      /* OP_OpenRead or OP_OpenWrite */
 ){
   Vdbe *v;
-  if( IsVirtual(pTab) ) return;
-  v = sqlite3GetVdbe(p);
+  assert( !IsVirtual(pTab) );
+  v = sqlite3GetVdbe(pParse);
   assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
-  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
-  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
-  sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(pTab->nCol), P4_INT32);
-  VdbeComment((v, "%s", pTab->zName));
+  sqlite3TableLock(pParse, iDb, pTab->tnum, 
+                   (opcode==OP_OpenWrite)?1:0, pTab->zName);
+  if( HasRowid(pTab) ){
+    sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nCol);
+    VdbeComment((v, "%s", pTab->zName));
+  }else{
+    Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+    assert( pPk!=0 );
+    assert( pPk->tnum==pTab->tnum );
+    sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
+    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+    VdbeComment((v, "%s", pTab->zName));
+  }
 }
 
 /*
@@ -87242,20 +106525,20 @@ SQLITE_PRIVATE void sqlite3OpenTable(
 **
 **  Character      Column affinity
 **  ------------------------------
-**  'a'            TEXT
-**  'b'            NONE
-**  'c'            NUMERIC
-**  'd'            INTEGER
-**  'e'            REAL
+**  'A'            BLOB
+**  'B'            TEXT
+**  'C'            NUMERIC
+**  'D'            INTEGER
+**  'F'            REAL
 **
-** An extra 'b' is appended to the end of the string to cover the
+** An extra 'D' is appended to the end of the string to cover the
 ** rowid that appears as the last column in every index.
 **
 ** Memory for the buffer containing the column index affinity string
 ** is managed along with the rest of the Index structure. It will be
 ** released when sqlite3DeleteIndex() is called.
 */
-SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
+SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
   if( !pIdx->zColAff ){
     /* The first time a column affinity string for a particular index is
     ** required, it is allocated and populated here. It is then stored as
@@ -87267,16 +106550,26 @@ SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
     */
     int n;
     Table *pTab = pIdx->pTable;
-    sqlite3 *db = sqlite3VdbeDb(v);
-    pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+2);
+    pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
     if( !pIdx->zColAff ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return 0;
     }
     for(n=0; n<pIdx->nColumn; n++){
-      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
+      i16 x = pIdx->aiColumn[n];
+      if( x>=0 ){
+        pIdx->zColAff[n] = pTab->aCol[x].affinity;
+      }else if( x==XN_ROWID ){
+        pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
+      }else{
+        char aff;
+        assert( x==XN_EXPR );
+        assert( pIdx->aColExpr!=0 );
+        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
+        if( aff==0 ) aff = SQLITE_AFF_BLOB;
+        pIdx->zColAff[n] = aff;
+      }
     }
-    pIdx->zColAff[n++] = SQLITE_AFF_NONE;
     pIdx->zColAff[n] = 0;
   }
  
@@ -87284,57 +106577,61 @@ SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
 }
 
 /*
-** Set P4 of the most recently inserted opcode to a column affinity
-** string for table pTab. A column affinity string has one character
-** for each column indexed by the index, according to the affinity of the
-** column:
+** Compute the affinity string for table pTab, if it has not already been
+** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
+**
+** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
+** if iReg>0 then code an OP_Affinity opcode that will set the affinities
+** for register iReg and following.  Or if affinities exists and iReg==0,
+** then just set the P4 operand of the previous opcode (which should  be
+** an OP_MakeRecord) to the affinity string.
+**
+** A column affinity string has one character per column:
 **
 **  Character      Column affinity
 **  ------------------------------
-**  'a'            TEXT
-**  'b'            NONE
-**  'c'            NUMERIC
-**  'd'            INTEGER
-**  'e'            REAL
-*/
-SQLITE_PRIVATE void sqlite3TableAffinityStr(Vdbe *v, Table *pTab){
-  /* The first time a column affinity string for a particular table
-  ** is required, it is allocated and populated here. It is then 
-  ** stored as a member of the Table structure for subsequent use.
-  **
-  ** The column affinity string will eventually be deleted by
-  ** sqlite3DeleteTable() when the Table structure itself is cleaned up.
-  */
-  if( !pTab->zColAff ){
-    char *zColAff;
-    int i;
+**  'A'            BLOB
+**  'B'            TEXT
+**  'C'            NUMERIC
+**  'D'            INTEGER
+**  'E'            REAL
+*/
+SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
+  int i;
+  char *zColAff = pTab->zColAff;
+  if( zColAff==0 ){
     sqlite3 *db = sqlite3VdbeDb(v);
-
     zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
     if( !zColAff ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       return;
     }
 
     for(i=0; i<pTab->nCol; i++){
       zColAff[i] = pTab->aCol[i].affinity;
     }
-    zColAff[pTab->nCol] = '\0';
-
+    do{
+      zColAff[i--] = 0;
+    }while( i>=0 && zColAff[i]==SQLITE_AFF_BLOB );
     pTab->zColAff = zColAff;
   }
-
-  sqlite3VdbeChangeP4(v, -1, pTab->zColAff, P4_TRANSIENT);
+  i = sqlite3Strlen30(zColAff);
+  if( i ){
+    if( iReg ){
+      sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
+    }else{
+      sqlite3VdbeChangeP4(v, -1, zColAff, i);
+    }
+  }
 }
 
 /*
 ** Return non-zero if the table pTab in database iDb or any of its indices
-** have been opened at any point in the VDBE program beginning at location
-** iStartAddr throught the end of the program.  This is used to see if 
+** have been opened at any point in the VDBE program. This is used to see if 
 ** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can 
-** run without using temporary table for the results of the SELECT. 
+** run without using a temporary table for the results of the SELECT. 
 */
-static int readsTable(Parse *p, int iStartAddr, int iDb, Table *pTab){
+static int readsTable(Parse *p, int iDb, Table *pTab){
   Vdbe *v = sqlite3GetVdbe(p);
   int i;
   int iEnd = sqlite3VdbeCurrentAddr(v);
@@ -87342,7 +106639,7 @@ static int readsTable(Parse *p, int iStartAddr, int iDb, Table *pTab){
   VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
 #endif
 
-  for(i=iStartAddr; i<iEnd; i++){
+  for(i=1; i<iEnd; i++){
     VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
     assert( pOp!=0 );
     if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
@@ -87402,7 +106699,7 @@ static int autoIncBegin(
     pInfo = pToplevel->pAinc;
     while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
     if( pInfo==0 ){
-      pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
+      pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
       if( pInfo==0 ) return 0;
       pInfo->pNext = pToplevel->pAinc;
       pToplevel->pAinc = pInfo;
@@ -87426,42 +106723,55 @@ SQLITE_PRIVATE void sqlite3AutoincrementBegin(Parse *pParse){
   sqlite3 *db = pParse->db;  /* The database connection */
   Db *pDb;                   /* Database only autoinc table */
   int memId;                 /* Register holding max rowid */
-  int addr;                  /* A VDBE address */
   Vdbe *v = pParse->pVdbe;   /* VDBE under construction */
 
   /* This routine is never called during trigger-generation.  It is
   ** only called from the top-level */
   assert( pParse->pTriggerTab==0 );
-  assert( pParse==sqlite3ParseToplevel(pParse) );
+  assert( sqlite3IsToplevel(pParse) );
 
   assert( v );   /* We failed long ago if this is not so */
   for(p = pParse->pAinc; p; p = p->pNext){
+    static const int iLn = VDBE_OFFSET_LINENO(2);
+    static const VdbeOpList autoInc[] = {
+      /* 0  */ {OP_Null,    0,  0, 0},
+      /* 1  */ {OP_Rewind,  0,  9, 0},
+      /* 2  */ {OP_Column,  0,  0, 0},
+      /* 3  */ {OP_Ne,      0,  7, 0},
+      /* 4  */ {OP_Rowid,   0,  0, 0},
+      /* 5  */ {OP_Column,  0,  1, 0},
+      /* 6  */ {OP_Goto,    0,  9, 0},
+      /* 7  */ {OP_Next,    0,  2, 0},
+      /* 8  */ {OP_Integer, 0,  0, 0},
+      /* 9  */ {OP_Close,   0,  0, 0} 
+    };
+    VdbeOp *aOp;
     pDb = &db->aDb[p->iDb];
     memId = p->regCtr;
     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
-    addr = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, p->pTab->zName, 0);
-    sqlite3VdbeAddOp2(v, OP_Rewind, 0, addr+9);
-    sqlite3VdbeAddOp3(v, OP_Column, 0, 0, memId);
-    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId);
-    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
-    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
-    sqlite3VdbeAddOp3(v, OP_Column, 0, 1, memId);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+9);
-    sqlite3VdbeAddOp2(v, OP_Next, 0, addr+2);
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
-    sqlite3VdbeAddOp0(v, OP_Close);
+    sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
+    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
+    if( aOp==0 ) break;
+    aOp[0].p2 = memId;
+    aOp[0].p3 = memId+1;
+    aOp[2].p3 = memId;
+    aOp[3].p1 = memId-1;
+    aOp[3].p3 = memId;
+    aOp[3].p5 = SQLITE_JUMPIFNULL;
+    aOp[4].p2 = memId+1;
+    aOp[5].p3 = memId;
+    aOp[8].p2 = memId;
   }
 }
 
 /*
 ** Update the maximum rowid for an autoincrement calculation.
 **
-** This routine should be called when the top of the stack holds a
+** This routine should be called when the regRowid register holds a
 ** new rowid that is about to be inserted.  If that new rowid is
 ** larger than the maximum rowid in the memId memory cell, then the
-** memory cell is updated.  The stack is unchanged.
+** memory cell is updated.
 */
 static void autoIncStep(Parse *pParse, int memId, int regRowid){
   if( memId>0 ){
@@ -87476,40 +106786,44 @@ static void autoIncStep(Parse *pParse, int memId, int regRowid){
 ** table (either directly or through triggers) needs to call this
 ** routine just before the "exit" code.
 */
-SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
+static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
   AutoincInfo *p;
   Vdbe *v = pParse->pVdbe;
   sqlite3 *db = pParse->db;
 
   assert( v );
   for(p = pParse->pAinc; p; p = p->pNext){
+    static const int iLn = VDBE_OFFSET_LINENO(2);
+    static const VdbeOpList autoIncEnd[] = {
+      /* 0 */ {OP_NotNull,     0, 2, 0},
+      /* 1 */ {OP_NewRowid,    0, 0, 0},
+      /* 2 */ {OP_MakeRecord,  0, 2, 0},
+      /* 3 */ {OP_Insert,      0, 0, 0},
+      /* 4 */ {OP_Close,       0, 0, 0}
+    };
+    VdbeOp *aOp;
     Db *pDb = &db->aDb[p->iDb];
-    int j1, j2, j3, j4, j5;
     int iRec;
     int memId = p->regCtr;
 
     iRec = sqlite3GetTempReg(pParse);
     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
-    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
-    j2 = sqlite3VdbeAddOp0(v, OP_Rewind);
-    j3 = sqlite3VdbeAddOp3(v, OP_Column, 0, 0, iRec);
-    j4 = sqlite3VdbeAddOp3(v, OP_Eq, memId-1, 0, iRec);
-    sqlite3VdbeAddOp2(v, OP_Next, 0, j3);
-    sqlite3VdbeJumpHere(v, j2);
-    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, memId+1);
-    j5 = sqlite3VdbeAddOp0(v, OP_Goto);
-    sqlite3VdbeJumpHere(v, j4);
-    sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
-    sqlite3VdbeJumpHere(v, j1);
-    sqlite3VdbeJumpHere(v, j5);
-    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
-    sqlite3VdbeAddOp3(v, OP_Insert, 0, iRec, memId+1);
-    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-    sqlite3VdbeAddOp0(v, OP_Close);
+    aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
+    if( aOp==0 ) break;
+    aOp[0].p1 = memId+1;
+    aOp[1].p2 = memId+1;
+    aOp[2].p1 = memId-1;
+    aOp[2].p3 = iRec;
+    aOp[3].p2 = iRec;
+    aOp[3].p3 = memId+1;
+    aOp[3].p5 = OPFLAG_APPEND;
     sqlite3ReleaseTempReg(pParse, iRec);
   }
 }
+SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
+  if( pParse->pAinc ) autoIncrementEnd(pParse);
+}
 #else
 /*
 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
@@ -87530,27 +106844,30 @@ static int xferOptimization(
 );
 
 /*
-** This routine is call to handle SQL of the following forms:
+** This routine is called to handle SQL of the following forms:
 **
-**    insert into TABLE (IDLIST) values(EXPRLIST)
+**    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
 **    insert into TABLE (IDLIST) select
+**    insert into TABLE (IDLIST) default values
 **
 ** The IDLIST following the table name is always optional.  If omitted,
-** then a list of all columns for the table is substituted.  The IDLIST
-** appears in the pColumn parameter.  pColumn is NULL if IDLIST is omitted.
+** then a list of all (non-hidden) columns for the table is substituted.
+** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST
+** is omitted.
 **
-** The pList parameter holds EXPRLIST in the first form of the INSERT
-** statement above, and pSelect is NULL.  For the second form, pList is
-** NULL and pSelect is a pointer to the select statement used to generate
-** data for the insert.
+** For the pSelect parameter holds the values to be inserted for the
+** first two forms shown above.  A VALUES clause is really just short-hand
+** for a SELECT statement that omits the FROM clause and everything else
+** that follows.  If the pSelect parameter is NULL, that means that the
+** DEFAULT VALUES form of the INSERT statement is intended.
 **
 ** The code generated follows one of four templates.  For a simple
-** select with data coming from a VALUES clause, the code executes
+** insert with data coming from a single-row VALUES clause, the code executes
 ** once straight down through.  Pseudo-code follows (we call this
 ** the "1st template"):
 **
 **         open write cursor to <table> and its indices
-**         puts VALUES clause expressions onto the stack
+**         put VALUES clause expressions into registers
 **         write the resulting record into <table>
 **         cleanup
 **
@@ -87582,7 +106899,6 @@ static int xferOptimization(
 ** and the SELECT clause does not read from <table> at any time.
 ** The generated code follows this template:
 **
-**         EOF <- 0
 **         X <- A
 **         goto B
 **      A: setup for the SELECT
@@ -87591,12 +106907,9 @@ static int xferOptimization(
 **           yield X
 **         end loop
 **         cleanup after the SELECT
-**         EOF <- 1
-**         yield X
-**         goto A
+**         end-coroutine X
 **      B: open write cursor to <table> and its indices
-**      C: yield X
-**         if EOF goto D
+**      C: yield X, at EOF goto D
 **         insert the select result into <table> from R..R+n
 **         goto C
 **      D: cleanup
@@ -87604,10 +106917,9 @@ static int xferOptimization(
 ** The 4th template is used if the insert statement takes its
 ** values from a SELECT but the data is being inserted into a table
 ** that is also read as part of the SELECT.  In the third form,
-** we have to use a intermediate table to store the results of
+** we have to use an intermediate table to store the results of
 ** the select.  The template is like this:
 **
-**         EOF <- 0
 **         X <- A
 **         goto B
 **      A: setup for the SELECT
@@ -87616,12 +106928,9 @@ static int xferOptimization(
 **           yield X
 **         end loop
 **         cleanup after the SELECT
-**         EOF <- 1
-**         yield X
-**         halt-error
+**         end co-routine R
 **      B: open temp table
-**      L: yield X
-**         if EOF goto M
+**      L: yield X, at EOF goto M
 **         insert row from R..R+n into temp table
 **         goto L
 **      M: open write cursor to <table> and its indices
@@ -87634,7 +106943,6 @@ static int xferOptimization(
 SQLITE_PRIVATE void sqlite3Insert(
   Parse *pParse,        /* Parser context */
   SrcList *pTabList,    /* Name of table into which we are inserting */
-  ExprList *pList,      /* List of values to be inserted */
   Select *pSelect,      /* A SELECT statement to use as the data source */
   IdList *pColumn,      /* Column names corresponding to IDLIST. */
   int onError           /* How to handle constraint errors */
@@ -87648,18 +106956,21 @@ SQLITE_PRIVATE void sqlite3Insert(
   Index *pIdx;          /* For looping over indices of the table */
   int nColumn;          /* Number of columns in the data */
   int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */
-  int baseCur = 0;      /* VDBE Cursor number for pTab */
-  int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
+  int iDataCur = 0;     /* VDBE cursor that is the main data repository */
+  int iIdxCur = 0;      /* First index cursor */
+  int ipkColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
   int endOfLoop;        /* Label for the end of the insertion loop */
-  int useTempTable = 0; /* Store SELECT results in intermediate table */
   int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */
   int addrInsTop = 0;   /* Jump to label "D" */
   int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */
-  int addrSelect = 0;   /* Address of coroutine that implements the SELECT */
   SelectDest dest;      /* Destination for SELECT on rhs of INSERT */
   int iDb;              /* Index of database holding TABLE */
   Db *pDb;              /* The database containing table being inserted into */
-  int appendFlag = 0;   /* True if the insert is likely to be an append */
+  u8 useTempTable = 0;  /* Store SELECT results in intermediate table */
+  u8 appendFlag = 0;    /* True if the insert is likely to be an append */
+  u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */
+  u8 bIdListInOrder;    /* True if IDLIST is in table order */
+  ExprList *pList = 0;  /* List of VALUES() to be inserted  */
 
   /* Register allocations */
   int regFromSelect = 0;/* Base register for data coming from SELECT */
@@ -87668,7 +106979,6 @@ SQLITE_PRIVATE void sqlite3Insert(
   int regIns;           /* Block of regs holding rowid+data being inserted */
   int regRowid;         /* registers holding insert rowid */
   int regData;          /* register holding first column to insert */
-  int regEof = 0;       /* Register recording end of SELECT data */
   int *aRegIdx = 0;     /* One register allocated to each index */
 
 #ifndef SQLITE_OMIT_TRIGGER
@@ -87683,6 +106993,17 @@ SQLITE_PRIVATE void sqlite3Insert(
     goto insert_cleanup;
   }
 
+  /* If the Select object is really just a simple VALUES() list with a
+  ** single row (the common case) then keep that one row of values
+  ** and discard the other (unused) parts of the pSelect object
+  */
+  if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
+    pList = pSelect->pEList;
+    pSelect->pEList = 0;
+    sqlite3SelectDelete(db, pSelect);
+    pSelect = 0;
+  }
+
   /* Locate the table into which we will be inserting new information.
   */
   assert( pTabList->nSrc==1 );
@@ -87699,6 +107020,7 @@ SQLITE_PRIVATE void sqlite3Insert(
   if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
     goto insert_cleanup;
   }
+  withoutRowid = !HasRowid(pTab);
 
   /* Figure out if we have any triggers and if the table being
   ** inserted into is a view
@@ -87718,16 +107040,13 @@ SQLITE_PRIVATE void sqlite3Insert(
   assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
 
   /* If pTab is really a view, make sure it has been initialized.
-  ** ViewGetColumnNames() is a no-op if pTab is not a view (or virtual 
-  ** module table).
+  ** ViewGetColumnNames() is a no-op if pTab is not a view.
   */
   if( sqlite3ViewGetColumnNames(pParse, pTab) ){
     goto insert_cleanup;
   }
 
-  /* Ensure that:
-  *  (a) the table is not read-only, 
-  *  (b) that if it is a view then ON INSERT triggers exist
+  /* Cannot insert into a read-only table.
   */
   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
     goto insert_cleanup;
@@ -87762,72 +107081,94 @@ SQLITE_PRIVATE void sqlite3Insert(
   */
   regAutoinc = autoIncBegin(pParse, iDb, pTab);
 
+  /* Allocate registers for holding the rowid of the new row,
+  ** the content of the new row, and the assembled row record.
+  */
+  regRowid = regIns = pParse->nMem+1;
+  pParse->nMem += pTab->nCol + 1;
+  if( IsVirtual(pTab) ){
+    regRowid++;
+    pParse->nMem++;
+  }
+  regData = regRowid+1;
+
+  /* If the INSERT statement included an IDLIST term, then make sure
+  ** all elements of the IDLIST really are columns of the table and 
+  ** remember the column indices.
+  **
+  ** If the table has an INTEGER PRIMARY KEY column and that column
+  ** is named in the IDLIST, then record in the ipkColumn variable
+  ** the index into IDLIST of the primary key column.  ipkColumn is
+  ** the index of the primary key as it appears in IDLIST, not as
+  ** is appears in the original table.  (The index of the INTEGER
+  ** PRIMARY KEY in the original table is pTab->iPKey.)
+  */
+  bIdListInOrder = (pTab->tabFlags & TF_OOOHidden)==0;
+  if( pColumn ){
+    for(i=0; i<pColumn->nId; i++){
+      pColumn->a[i].idx = -1;
+    }
+    for(i=0; i<pColumn->nId; i++){
+      for(j=0; j<pTab->nCol; j++){
+        if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
+          pColumn->a[i].idx = j;
+          if( i!=j ) bIdListInOrder = 0;
+          if( j==pTab->iPKey ){
+            ipkColumn = i;  assert( !withoutRowid );
+          }
+          break;
+        }
+      }
+      if( j>=pTab->nCol ){
+        if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){
+          ipkColumn = i;
+          bIdListInOrder = 0;
+        }else{
+          sqlite3ErrorMsg(pParse, "table %S has no column named %s",
+              pTabList, 0, pColumn->a[i].zName);
+          pParse->checkSchema = 1;
+          goto insert_cleanup;
+        }
+      }
+    }
+  }
+
   /* Figure out how many columns of data are supplied.  If the data
   ** is coming from a SELECT statement, then generate a co-routine that
   ** produces a single row of the SELECT on each invocation.  The
   ** co-routine is the common header to the 3rd and 4th templates.
   */
   if( pSelect ){
-    /* Data is coming from a SELECT.  Generate code to implement that SELECT
-    ** as a co-routine.  The code is common to both the 3rd and 4th
-    ** templates:
-    **
-    **         EOF <- 0
-    **         X <- A
-    **         goto B
-    **      A: setup for the SELECT
-    **         loop over the tables in the SELECT
-    **           load value into register R..R+n
-    **           yield X
-    **         end loop
-    **         cleanup after the SELECT
-    **         EOF <- 1
-    **         yield X
-    **         halt-error
-    **
-    ** On each invocation of the co-routine, it puts a single row of the
-    ** SELECT result into registers dest.iMem...dest.iMem+dest.nMem-1.
-    ** (These output registers are allocated by sqlite3Select().)  When
-    ** the SELECT completes, it sets the EOF flag stored in regEof.
-    */
-    int rc, j1;
-
-    regEof = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof);      /* EOF <- 0 */
-    VdbeComment((v, "SELECT eof flag"));
-    sqlite3SelectDestInit(&dest, SRT_Coroutine, ++pParse->nMem);
-    addrSelect = sqlite3VdbeCurrentAddr(v)+2;
-    sqlite3VdbeAddOp2(v, OP_Integer, addrSelect-1, dest.iParm);
-    j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
-    VdbeComment((v, "Jump over SELECT coroutine"));
-
-    /* Resolve the expressions in the SELECT statement and execute it. */
+    /* Data is coming from a SELECT or from a multi-row VALUES clause.
+    ** Generate a co-routine to run the SELECT. */
+    int regYield;       /* Register holding co-routine entry-point */
+    int addrTop;        /* Top of the co-routine */
+    int rc;             /* Result code */
+
+    regYield = ++pParse->nMem;
+    addrTop = sqlite3VdbeCurrentAddr(v) + 1;
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
+    sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
+    dest.iSdst = bIdListInOrder ? regData : 0;
+    dest.nSdst = pTab->nCol;
     rc = sqlite3Select(pParse, pSelect, &dest);
-    assert( pParse->nErr==0 || rc );
-    if( rc || NEVER(pParse->nErr) || db->mallocFailed ){
-      goto insert_cleanup;
-    }
-    sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof);         /* EOF <- 1 */
-    sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);   /* yield X */
-    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
-    VdbeComment((v, "End of SELECT coroutine"));
-    sqlite3VdbeJumpHere(v, j1);                          /* label B: */
-
-    regFromSelect = dest.iMem;
+    regFromSelect = dest.iSdst;
+    if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
+    sqlite3VdbeEndCoroutine(v, regYield);
+    sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */
     assert( pSelect->pEList );
     nColumn = pSelect->pEList->nExpr;
-    assert( dest.nMem==nColumn );
 
     /* Set useTempTable to TRUE if the result of the SELECT statement
     ** should be written into a temporary table (template 4).  Set to
-    ** FALSE if each* row of the SELECT can be written directly into
+    ** FALSE if each output row of the SELECT can be written directly into
     ** the destination table (template 3).
     **
     ** A temp table must be used if the table being updated is also one
     ** of the tables being read by the SELECT statement.  Also use a 
     ** temp table in the case of row triggers.
     */
-    if( pTrigger || readsTable(pParse, addrSelect, iDb, pTab) ){
+    if( pTrigger || readsTable(pParse, iDb, pTab) ){
       useTempTable = 1;
     }
 
@@ -87837,55 +107178,60 @@ SQLITE_PRIVATE void sqlite3Insert(
       ** here is from the 4th template:
       **
       **      B: open temp table
-      **      L: yield X
-      **         if EOF goto M
+      **      L: yield X, goto M at EOF
       **         insert row from R..R+n into temp table
       **         goto L
       **      M: ...
       */
       int regRec;          /* Register to hold packed record */
       int regTempRowid;    /* Register to hold temp table ROWID */
-      int addrTop;         /* Label "L" */
-      int addrIf;          /* Address of jump to M */
+      int addrL;           /* Label "L" */
 
       srcTab = pParse->nTab++;
       regRec = sqlite3GetTempReg(pParse);
       regTempRowid = sqlite3GetTempReg(pParse);
       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
-      addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
-      addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof);
+      addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);
       sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
       sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
       sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
-      sqlite3VdbeJumpHere(v, addrIf);
+      sqlite3VdbeGoto(v, addrL);
+      sqlite3VdbeJumpHere(v, addrL);
       sqlite3ReleaseTempReg(pParse, regRec);
       sqlite3ReleaseTempReg(pParse, regTempRowid);
     }
   }else{
-    /* This is the case if the data for the INSERT is coming from a VALUES
-    ** clause
+    /* This is the case if the data for the INSERT is coming from a 
+    ** single-row VALUES clause
     */
     NameContext sNC;
     memset(&sNC, 0, sizeof(sNC));
     sNC.pParse = pParse;
     srcTab = -1;
     assert( useTempTable==0 );
-    nColumn = pList ? pList->nExpr : 0;
-    for(i=0; i<nColumn; i++){
-      if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
+    if( pList ){
+      nColumn = pList->nExpr;
+      if( sqlite3ResolveExprListNames(&sNC, pList) ){
         goto insert_cleanup;
       }
+    }else{
+      nColumn = 0;
     }
   }
 
+  /* If there is no IDLIST term but the table has an integer primary
+  ** key, the set the ipkColumn variable to the integer primary key 
+  ** column index in the original table definition.
+  */
+  if( pColumn==0 && nColumn>0 ){
+    ipkColumn = pTab->iPKey;
+  }
+
   /* Make sure the number of columns in the source data matches the number
   ** of columns to be inserted into the table.
   */
-  if( IsVirtual(pTab) ){
-    for(i=0; i<pTab->nCol; i++){
-      nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
-    }
+  for(i=0; i<pTab->nCol; i++){
+    nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
   }
   if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
     sqlite3ErrorMsg(pParse, 
@@ -87897,52 +107243,6 @@ SQLITE_PRIVATE void sqlite3Insert(
     sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
     goto insert_cleanup;
   }
-
-  /* If the INSERT statement included an IDLIST term, then make sure
-  ** all elements of the IDLIST really are columns of the table and 
-  ** remember the column indices.
-  **
-  ** If the table has an INTEGER PRIMARY KEY column and that column
-  ** is named in the IDLIST, then record in the keyColumn variable
-  ** the index into IDLIST of the primary key column.  keyColumn is
-  ** the index of the primary key as it appears in IDLIST, not as
-  ** is appears in the original table.  (The index of the primary
-  ** key in the original table is pTab->iPKey.)
-  */
-  if( pColumn ){
-    for(i=0; i<pColumn->nId; i++){
-      pColumn->a[i].idx = -1;
-    }
-    for(i=0; i<pColumn->nId; i++){
-      for(j=0; j<pTab->nCol; j++){
-        if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
-          pColumn->a[i].idx = j;
-          if( j==pTab->iPKey ){
-            keyColumn = i;
-          }
-          break;
-        }
-      }
-      if( j>=pTab->nCol ){
-        if( sqlite3IsRowid(pColumn->a[i].zName) ){
-          keyColumn = i;
-        }else{
-          sqlite3ErrorMsg(pParse, "table %S has no column named %s",
-              pTabList, 0, pColumn->a[i].zName);
-          pParse->checkSchema = 1;
-          goto insert_cleanup;
-        }
-      }
-    }
-  }
-
-  /* If there is no IDLIST term but the table has an integer primary
-  ** key, the set the keyColumn variable to the primary key column index
-  ** in the original table definition.
-  */
-  if( pColumn==0 && nColumn>0 ){
-    keyColumn = pTab->iPKey;
-  }
     
   /* Initialize the count of rows to be inserted
   */
@@ -87954,10 +107254,9 @@ SQLITE_PRIVATE void sqlite3Insert(
   /* If this is not a view, open the table and and all indices */
   if( !isView ){
     int nIdx;
-
-    baseCur = pParse->nTab;
-    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, baseCur, OP_OpenWrite);
-    aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
+    nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
+                                      &iDataCur, &iIdxCur);
+    aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+1));
     if( aRegIdx==0 ){
       goto insert_cleanup;
     }
@@ -87971,39 +107270,27 @@ SQLITE_PRIVATE void sqlite3Insert(
     /* This block codes the top of loop only.  The complete loop is the
     ** following pseudocode (template 4):
     **
-    **         rewind temp table
+    **         rewind temp table, if empty goto D
     **      C: loop over rows of intermediate table
     **           transfer values form intermediate table into <table>
     **         end loop
     **      D: ...
     */
-    addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab);
+    addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);
     addrCont = sqlite3VdbeCurrentAddr(v);
   }else if( pSelect ){
     /* This block codes the top of loop only.  The complete loop is the
     ** following pseudocode (template 3):
     **
-    **      C: yield X
-    **         if EOF goto D
+    **      C: yield X, at EOF goto D
     **         insert the select result into <table> from R..R+n
     **         goto C
     **      D: ...
     */
-    addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
-    addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
+    addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
+    VdbeCoverage(v);
   }
 
-  /* Allocate registers for holding the rowid of the new row,
-  ** the content of the new row, and the assemblied row record.
-  */
-  regRowid = regIns = pParse->nMem+1;
-  pParse->nMem += pTab->nCol + 1;
-  if( IsVirtual(pTab) ){
-    regRowid++;
-    pParse->nMem++;
-  }
-  regData = regRowid+1;
-
   /* Run the BEFORE and INSTEAD OF triggers, if there are any
   */
   endOfLoop = sqlite3VdbeMakeLabel(v);
@@ -88016,20 +107303,21 @@ SQLITE_PRIVATE void sqlite3Insert(
     ** we do not know what the unique ID will be (because the insert has
     ** not happened yet) so we substitute a rowid of -1
     */
-    if( keyColumn<0 ){
+    if( ipkColumn<0 ){
       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
     }else{
-      int j1;
+      int addr1;
+      assert( !withoutRowid );
       if( useTempTable ){
-        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regCols);
+        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
       }else{
         assert( pSelect==0 );  /* Otherwise useTempTable is true */
-        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regCols);
+        sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
       }
-      j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols);
+      addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
-      sqlite3VdbeJumpHere(v, j1);
-      sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols);
+      sqlite3VdbeJumpHere(v, addr1);
+      sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
     }
 
     /* Cannot have triggers on a virtual table. If it were possible,
@@ -88039,15 +107327,14 @@ SQLITE_PRIVATE void sqlite3Insert(
 
     /* Create the new column data
     */
-    for(i=0; i<pTab->nCol; i++){
-      if( pColumn==0 ){
-        j = i;
-      }else{
+    for(i=j=0; i<pTab->nCol; i++){
+      if( pColumn ){
         for(j=0; j<pColumn->nId; j++){
           if( pColumn->a[j].idx==i ) break;
         }
       }
-      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId) ){
+      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId)
+            || (pColumn==0 && IsOrdinaryHiddenColumn(&pTab->aCol[i])) ){
         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
       }else if( useTempTable ){
         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1); 
@@ -88055,6 +107342,7 @@ SQLITE_PRIVATE void sqlite3Insert(
         assert( pSelect==0 ); /* Otherwise useTempTable is true */
         sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
       }
+      if( pColumn==0 && !IsOrdinaryHiddenColumn(&pTab->aCol[i]) ) j++;
     }
 
     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
@@ -88063,8 +107351,7 @@ SQLITE_PRIVATE void sqlite3Insert(
     ** table column affinities.
     */
     if( !isView ){
-      sqlite3VdbeAddOp2(v, OP_Affinity, regCols+1, pTab->nCol);
-      sqlite3TableAffinityStr(v, pTab);
+      sqlite3TableAffinity(v, pTab, regCols+1);
     }
 
     /* Fire BEFORE or INSTEAD OF triggers */
@@ -88074,29 +107361,27 @@ SQLITE_PRIVATE void sqlite3Insert(
     sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
   }
 
-  /* Push the record number for the new entry onto the stack.  The
-  ** record number is a randomly generate integer created by NewRowid
-  ** except when the table has an INTEGER PRIMARY KEY column, in which
-  ** case the record number is the same as that column. 
+  /* Compute the content of the next row to insert into a range of
+  ** registers beginning at regIns.
   */
   if( !isView ){
     if( IsVirtual(pTab) ){
       /* The row that the VUpdate opcode will delete: none */
       sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
     }
-    if( keyColumn>=0 ){
+    if( ipkColumn>=0 ){
       if( useTempTable ){
-        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
+        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
       }else if( pSelect ){
-        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
+        sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
       }else{
         VdbeOp *pOp;
-        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
+        sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
         pOp = sqlite3VdbeGetOp(v, -1);
         if( ALWAYS(pOp) && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
           appendFlag = 1;
           pOp->opcode = OP_NewRowid;
-          pOp->p1 = baseCur;
+          pOp->p1 = iDataCur;
           pOp->p2 = regRowid;
           pOp->p3 = regAutoinc;
         }
@@ -88105,26 +107390,26 @@ SQLITE_PRIVATE void sqlite3Insert(
       ** to generate a unique primary key value.
       */
       if( !appendFlag ){
-        int j1;
+        int addr1;
         if( !IsVirtual(pTab) ){
-          j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
-          sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
-          sqlite3VdbeJumpHere(v, j1);
+          addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
+          sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
+          sqlite3VdbeJumpHere(v, addr1);
         }else{
-          j1 = sqlite3VdbeCurrentAddr(v);
-          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, j1+2);
+          addr1 = sqlite3VdbeCurrentAddr(v);
+          sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
         }
-        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
+        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
       }
-    }else if( IsVirtual(pTab) ){
+    }else if( IsVirtual(pTab) || withoutRowid ){
       sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
     }else{
-      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
+      sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
       appendFlag = 1;
     }
     autoIncStep(pParse, regAutoinc, regRowid);
 
-    /* Push onto the stack, data for all columns of the new entry, beginning
+    /* Compute data for all columns of the new entry, beginning
     ** with the first column.
     */
     nHidden = 0;
@@ -88132,15 +107417,15 @@ SQLITE_PRIVATE void sqlite3Insert(
       int iRegStore = regRowid+1+i;
       if( i==pTab->iPKey ){
         /* The value of the INTEGER PRIMARY KEY column is always a NULL.
-        ** Whenever this column is read, the record number will be substituted
-        ** in its place.  So will fill this column with a NULL to avoid
-        ** taking up data space with information that will never be used. */
-        sqlite3VdbeAddOp2(v, OP_Null, 0, iRegStore);
+        ** Whenever this column is read, the rowid will be substituted
+        ** in its place.  Hence, fill this column with a NULL to avoid
+        ** taking up data space with information that will never be used.
+        ** As there may be shallow copies of this value, make it a soft-NULL */
+        sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
         continue;
       }
       if( pColumn==0 ){
         if( IsHiddenColumn(&pTab->aCol[i]) ){
-          assert( IsVirtual(pTab) );
           j = -1;
           nHidden++;
         }else{
@@ -88152,11 +107437,13 @@ SQLITE_PRIVATE void sqlite3Insert(
         }
       }
       if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
-        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, iRegStore);
+        sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
       }else if( useTempTable ){
         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore); 
       }else if( pSelect ){
-        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
+        if( regFromSelect!=regData ){
+          sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
+        }
       }else{
         sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
       }
@@ -88176,13 +107463,12 @@ SQLITE_PRIVATE void sqlite3Insert(
 #endif
     {
       int isReplace;    /* Set to true if constraints may cause a replace */
-      sqlite3GenerateConstraintChecks(pParse, pTab, baseCur, regIns, aRegIdx,
-          keyColumn>=0, 0, onError, endOfLoop, &isReplace
-      );
-      sqlite3FkCheck(pParse, pTab, 0, regIns);
-      sqlite3CompleteInsertion(
-          pParse, pTab, baseCur, regIns, aRegIdx, 0, appendFlag, isReplace==0
+      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
+          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0
       );
+      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
+      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
+                               regIns, aRegIdx, 0, appendFlag, isReplace==0);
     }
   }
 
@@ -88203,19 +107489,19 @@ SQLITE_PRIVATE void sqlite3Insert(
   */
   sqlite3VdbeResolveLabel(v, endOfLoop);
   if( useTempTable ){
-    sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont);
+    sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);
     sqlite3VdbeJumpHere(v, addrInsTop);
     sqlite3VdbeAddOp1(v, OP_Close, srcTab);
   }else if( pSelect ){
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
+    sqlite3VdbeGoto(v, addrCont);
     sqlite3VdbeJumpHere(v, addrInsTop);
   }
 
   if( !IsVirtual(pTab) && !isView ){
     /* Close all tables opened */
-    sqlite3VdbeAddOp1(v, OP_Close, baseCur);
-    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
-      sqlite3VdbeAddOp1(v, OP_Close, idx+baseCur);
+    if( iDataCur<iIdxCur ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
+    for(idx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
+      sqlite3VdbeAddOp1(v, OP_Close, idx+iIdxCur);
     }
   }
 
@@ -88248,7 +107534,7 @@ insert_cleanup:
 }
 
 /* Make sure "isView" and other macros defined above are undefined. Otherwise
-** thely may interfere with compilation of other functions in this file
+** they may interfere with compilation of other functions in this file
 ** (or in another file, if this file becomes part of the amalgamation).  */
 #ifdef isView
  #undef isView
@@ -88260,36 +107546,101 @@ insert_cleanup:
  #undef tmask
 #endif
 
+/*
+** Meanings of bits in of pWalker->eCode for checkConstraintUnchanged()
+*/
+#define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */
+#define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */
+
+/* This is the Walker callback from checkConstraintUnchanged().  Set
+** bit 0x01 of pWalker->eCode if
+** pWalker->eCode to 0 if this expression node references any of the
+** columns that are being modifed by an UPDATE statement.
+*/
+static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN ){
+    assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
+    if( pExpr->iColumn>=0 ){
+      if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
+        pWalker->eCode |= CKCNSTRNT_COLUMN;
+      }
+    }else{
+      pWalker->eCode |= CKCNSTRNT_ROWID;
+    }
+  }
+  return WRC_Continue;
+}
 
 /*
-** Generate code to do constraint checks prior to an INSERT or an UPDATE.
-**
-** The input is a range of consecutive registers as follows:
-**
-**    1.  The rowid of the row after the update.
-**
-**    2.  The data in the first column of the entry after the update.
+** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The
+** only columns that are modified by the UPDATE are those for which
+** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
 **
-**    i.  Data from middle columns...
-**
-**    N.  The data in the last column of the entry after the update.
-**
-** The regRowid parameter is the index of the register containing (1).
-**
-** If isUpdate is true and rowidChng is non-zero, then rowidChng contains
-** the address of a register containing the rowid before the update takes
-** place. isUpdate is true for UPDATEs and false for INSERTs. If isUpdate
-** is false, indicating an INSERT statement, then a non-zero rowidChng 
-** indicates that the rowid was explicitly specified as part of the
-** INSERT statement. If rowidChng is false, it means that  the rowid is
-** computed automatically in an insert or that the rowid value is not 
-** modified by an update.
-**
-** The code generated by this routine store new index entries into
+** Return true if CHECK constraint pExpr does not use any of the
+** changing columns (or the rowid if it is changing).  In other words,
+** return true if this CHECK constraint can be skipped when validating
+** the new row in the UPDATE statement.
+*/
+static int checkConstraintUnchanged(Expr *pExpr, int *aiChng, int chngRowid){
+  Walker w;
+  memset(&w, 0, sizeof(w));
+  w.eCode = 0;
+  w.xExprCallback = checkConstraintExprNode;
+  w.u.aiCol = aiChng;
+  sqlite3WalkExpr(&w, pExpr);
+  if( !chngRowid ){
+    testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
+    w.eCode &= ~CKCNSTRNT_ROWID;
+  }
+  testcase( w.eCode==0 );
+  testcase( w.eCode==CKCNSTRNT_COLUMN );
+  testcase( w.eCode==CKCNSTRNT_ROWID );
+  testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
+  return !w.eCode;
+}
+
+/*
+** Generate code to do constraint checks prior to an INSERT or an UPDATE
+** on table pTab.
+**
+** The regNewData parameter is the first register in a range that contains
+** the data to be inserted or the data after the update.  There will be
+** pTab->nCol+1 registers in this range.  The first register (the one
+** that regNewData points to) will contain the new rowid, or NULL in the
+** case of a WITHOUT ROWID table.  The second register in the range will
+** contain the content of the first table column.  The third register will
+** contain the content of the second table column.  And so forth.
+**
+** The regOldData parameter is similar to regNewData except that it contains
+** the data prior to an UPDATE rather than afterwards.  regOldData is zero
+** for an INSERT.  This routine can distinguish between UPDATE and INSERT by
+** checking regOldData for zero.
+**
+** For an UPDATE, the pkChng boolean is true if the true primary key (the
+** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
+** might be modified by the UPDATE.  If pkChng is false, then the key of
+** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
+**
+** For an INSERT, the pkChng boolean indicates whether or not the rowid
+** was explicitly specified as part of the INSERT statement.  If pkChng
+** is zero, it means that the either rowid is computed automatically or
+** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,
+** pkChng will only be true if the INSERT statement provides an integer
+** value for either the rowid column or its INTEGER PRIMARY KEY alias.
+**
+** The code generated by this routine will store new index entries into
 ** registers identified by aRegIdx[].  No index entry is created for
 ** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
 ** the same as the order of indices on the linked list of indices
-** attached to the table.
+** at pTab->pIndex.
+**
+** The caller must have already opened writeable cursors on the main
+** table and all applicable indices (that is to say, all indices for which
+** aRegIdx[] is not zero).  iDataCur is the cursor for the main table when
+** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
+** index when operating on a WITHOUT ROWID table.  iIdxCur is the cursor
+** for the first index in the pTab->pIndex list.  Cursors for other indices
+** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
 **
 ** This routine also generates code to check constraints.  NOT NULL,
 ** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,
@@ -88299,22 +107650,23 @@ insert_cleanup:
 **  Constraint type  Action       What Happens
 **  ---------------  ----------   ----------------------------------------
 **  any              ROLLBACK     The current transaction is rolled back and
-**                                sqlite3_exec() returns immediately with a
+**                                sqlite3_step() returns immediately with a
 **                                return code of SQLITE_CONSTRAINT.
 **
 **  any              ABORT        Back out changes from the current command
 **                                only (do not do a complete rollback) then
-**                                cause sqlite3_exec() to return immediately
+**                                cause sqlite3_step() to return immediately
 **                                with SQLITE_CONSTRAINT.
 **
-**  any              FAIL         Sqlite_exec() returns immediately with a
+**  any              FAIL         Sqlite3_step() returns immediately with a
 **                                return code of SQLITE_CONSTRAINT.  The
 **                                transaction is not rolled back and any
-**                                prior changes are retained.
+**                                changes to prior rows are retained.
 **
-**  any              IGNORE       The record number and data is popped from
-**                                the stack and there is an immediate jump
-**                                to label ignoreDest.
+**  any              IGNORE       The attempt in insert or update the current
+**                                row is skipped, without throwing an error.
+**                                Processing continues with the next row.
+**                                (There is an immediate jump to ignoreDest.)
 **
 **  NOT NULL         REPLACE      The NULL value is replace by the default
 **                                value for that column.  If the default value
@@ -88329,51 +107681,73 @@ insert_cleanup:
 ** Or if overrideError==OE_Default, then the pParse->onError parameter
 ** is used.  Or if pParse->onError==OE_Default then the onError value
 ** for the constraint is used.
-**
-** The calling routine must open a read/write cursor for pTab with
-** cursor number "baseCur".  All indices of pTab must also have open
-** read/write cursors with cursor number baseCur+i for the i-th cursor.
-** Except, if there is no possibility of a REPLACE action then
-** cursors do not need to be open for indices where aRegIdx[i]==0.
 */
 SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
-  Parse *pParse,      /* The parser context */
-  Table *pTab,        /* the table into which we are inserting */
-  int baseCur,        /* Index of a read/write cursor pointing at pTab */
-  int regRowid,       /* Index of the range of input registers */
-  int *aRegIdx,       /* Register used by each index.  0 for unused indices */
-  int rowidChng,      /* True if the rowid might collide with existing entry */
-  int isUpdate,       /* True for UPDATE, False for INSERT */
-  int overrideError,  /* Override onError to this if not OE_Default */
-  int ignoreDest,     /* Jump to this label on an OE_Ignore resolution */
-  int *pbMayReplace   /* OUT: Set to true if constraint may cause a replace */
-){
-  int i;              /* loop counter */
-  Vdbe *v;            /* VDBE under constrution */
-  int nCol;           /* Number of columns */
-  int onError;        /* Conflict resolution strategy */
-  int j1;             /* Addresss of jump instruction */
-  int j2 = 0, j3;     /* Addresses of jump instructions */
-  int regData;        /* Register containing first data column */
-  int iCur;           /* Table cursor number */
+  Parse *pParse,       /* The parser context */
+  Table *pTab,         /* The table being inserted or updated */
+  int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */
+  int iDataCur,        /* Canonical data cursor (main table or PK index) */
+  int iIdxCur,         /* First index cursor */
+  int regNewData,      /* First register in a range holding values to insert */
+  int regOldData,      /* Previous content.  0 for INSERTs */
+  u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */
+  u8 overrideError,    /* Override onError to this if not OE_Default */
+  int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
+  int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */
+  int *aiChng          /* column i is unchanged if aiChng[i]<0 */
+){
+  Vdbe *v;             /* VDBE under constrution */
   Index *pIdx;         /* Pointer to one of the indices */
+  Index *pPk = 0;      /* The PRIMARY KEY index */
+  sqlite3 *db;         /* Database connection */
+  int i;               /* loop counter */
+  int ix;              /* Index loop counter */
+  int nCol;            /* Number of columns */
+  int onError;         /* Conflict resolution strategy */
+  int addr1;           /* Address of jump instruction */
   int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
-  int regOldRowid = (rowidChng && isUpdate) ? rowidChng : regRowid;
-
+  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
+  int ipkTop = 0;      /* Top of the rowid change constraint check */
+  int ipkBottom = 0;   /* Bottom of the rowid change constraint check */
+  u8 isUpdate;         /* True if this is an UPDATE operation */
+  u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
+  int regRowid = -1;   /* Register holding ROWID value */
+
+  isUpdate = regOldData!=0;
+  db = pParse->db;
   v = sqlite3GetVdbe(pParse);
   assert( v!=0 );
   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
   nCol = pTab->nCol;
-  regData = regRowid + 1;
+  
+  /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
+  ** normal rowid tables.  nPkField is the number of key fields in the 
+  ** pPk index or 1 for a rowid table.  In other words, nPkField is the
+  ** number of fields in the true primary key of the table. */
+  if( HasRowid(pTab) ){
+    pPk = 0;
+    nPkField = 1;
+  }else{
+    pPk = sqlite3PrimaryKeyIndex(pTab);
+    nPkField = pPk->nKeyCol;
+  }
+
+  /* Record that this module has started */
+  VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
+                     iDataCur, iIdxCur, regNewData, regOldData, pkChng));
 
   /* Test all NOT NULL constraints.
   */
   for(i=0; i<nCol; i++){
     if( i==pTab->iPKey ){
+      continue;        /* ROWID is never NULL */
+    }
+    if( aiChng && aiChng[i]<0 ){
+      /* Don't bother checking for NOT NULL on columns that do not change */
       continue;
     }
     onError = pTab->aCol[i].notNull;
-    if( onError==OE_None ) continue;
+    if( onError==OE_None ) continue;  /* This column is allowed to be NULL */
     if( overrideError!=OE_Default ){
       onError = overrideError;
     }else if( onError==OE_Default ){
@@ -88387,25 +107761,28 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     switch( onError ){
       case OE_Abort:
         sqlite3MayAbort(pParse);
+        /* Fall through */
       case OE_Rollback:
       case OE_Fail: {
-        char *zMsg;
-        sqlite3VdbeAddOp3(v, OP_HaltIfNull,
-                                  SQLITE_CONSTRAINT, onError, regData+i);
-        zMsg = sqlite3MPrintf(pParse->db, "%s.%s may not be NULL",
-                              pTab->zName, pTab->aCol[i].zName);
-        sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
+        char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
+                                    pTab->aCol[i].zName);
+        sqlite3VdbeAddOp4(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL, onError,
+                          regNewData+1+i, zMsg, P4_DYNAMIC);
+        sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
+        VdbeCoverage(v);
         break;
       }
       case OE_Ignore: {
-        sqlite3VdbeAddOp2(v, OP_IsNull, regData+i, ignoreDest);
+        sqlite3VdbeAddOp2(v, OP_IsNull, regNewData+1+i, ignoreDest);
+        VdbeCoverage(v);
         break;
       }
       default: {
         assert( onError==OE_Replace );
-        j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regData+i);
-        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regData+i);
-        sqlite3VdbeJumpHere(v, j1);
+        addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regNewData+1+i);
+           VdbeCoverage(v);
+        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regNewData+1+i);
+        sqlite3VdbeJumpHere(v, addr1);
         break;
       }
     }
@@ -88414,37 +107791,74 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
   /* Test all CHECK constraints
   */
 #ifndef SQLITE_OMIT_CHECK
-  if( pTab->pCheck && (pParse->db->flags & SQLITE_IgnoreChecks)==0 ){
-    int allOk = sqlite3VdbeMakeLabel(v);
-    pParse->ckBase = regData;
-    sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, SQLITE_JUMPIFNULL);
+  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
+    ExprList *pCheck = pTab->pCheck;
+    pParse->ckBase = regNewData+1;
     onError = overrideError!=OE_Default ? overrideError : OE_Abort;
-    if( onError==OE_Ignore ){
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
-    }else{
-      if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
-      sqlite3HaltConstraint(pParse, onError, 0, 0);
+    for(i=0; i<pCheck->nExpr; i++){
+      int allOk;
+      Expr *pExpr = pCheck->a[i].pExpr;
+      if( aiChng && checkConstraintUnchanged(pExpr, aiChng, pkChng) ) continue;
+      allOk = sqlite3VdbeMakeLabel(v);
+      sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);
+      if( onError==OE_Ignore ){
+        sqlite3VdbeGoto(v, ignoreDest);
+      }else{
+        char *zName = pCheck->a[i].zName;
+        if( zName==0 ) zName = pTab->zName;
+        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
+        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
+                              onError, zName, P4_TRANSIENT,
+                              P5_ConstraintCheck);
+      }
+      sqlite3VdbeResolveLabel(v, allOk);
     }
-    sqlite3VdbeResolveLabel(v, allOk);
   }
 #endif /* !defined(SQLITE_OMIT_CHECK) */
 
-  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
-  ** of the new record does not previously exist.  Except, if this
-  ** is an UPDATE and the primary key is not changing, that is OK.
+  /* If rowid is changing, make sure the new rowid does not previously
+  ** exist in the table.
   */
-  if( rowidChng ){
+  if( pkChng && pPk==0 ){
+    int addrRowidOk = sqlite3VdbeMakeLabel(v);
+
+    /* Figure out what action to take in case of a rowid collision */
     onError = pTab->keyConf;
     if( overrideError!=OE_Default ){
       onError = overrideError;
     }else if( onError==OE_Default ){
       onError = OE_Abort;
     }
-    
+
     if( isUpdate ){
-      j2 = sqlite3VdbeAddOp3(v, OP_Eq, regRowid, 0, rowidChng);
+      /* pkChng!=0 does not mean that the rowid has change, only that
+      ** it might have changed.  Skip the conflict logic below if the rowid
+      ** is unchanged. */
+      sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
+      sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
+      VdbeCoverage(v);
+    }
+
+    /* If the response to a rowid conflict is REPLACE but the response
+    ** to some other UNIQUE constraint is FAIL or IGNORE, then we need
+    ** to defer the running of the rowid conflict checking until after
+    ** the UNIQUE constraints have run.
+    */
+    if( onError==OE_Replace && overrideError!=OE_Replace ){
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        if( pIdx->onError==OE_Ignore || pIdx->onError==OE_Fail ){
+          ipkTop = sqlite3VdbeAddOp0(v, OP_Goto);
+          break;
+        }
+      }
     }
-    j3 = sqlite3VdbeAddOp3(v, OP_NotExists, baseCur, 0, regRowid);
+
+    /* Check to see if the new rowid already exists in the table.  Skip
+    ** the following conflict logic if it does not. */
+    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
+    VdbeCoverage(v);
+
+    /* Generate code that deals with a rowid collision */
     switch( onError ){
       default: {
         onError = OE_Abort;
@@ -88453,14 +107867,13 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
       case OE_Rollback:
       case OE_Abort:
       case OE_Fail: {
-        sqlite3HaltConstraint(
-          pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
+        sqlite3RowidConstraint(pParse, onError, pTab);
         break;
       }
       case OE_Replace: {
         /* If there are DELETE triggers on this table and the
         ** recursive-triggers flag is set, call GenerateRowDelete() to
-        ** remove the conflicting row from the the table. This will fire
+        ** remove the conflicting row from the table. This will fire
         ** the triggers and remove both the table and index b-tree entries.
         **
         ** Otherwise, if there are no triggers or the recursive-triggers
@@ -88481,62 +107894,117 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
         ** table.
         */
         Trigger *pTrigger = 0;
-        if( pParse->db->flags&SQLITE_RecTriggers ){
+        if( db->flags&SQLITE_RecTriggers ){
           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
         }
         if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
           sqlite3MultiWrite(pParse);
-          sqlite3GenerateRowDelete(
-              pParse, pTab, baseCur, regRowid, 0, pTrigger, OE_Replace
-          );
-        }else if( pTab->pIndex ){
-          sqlite3MultiWrite(pParse);
-          sqlite3GenerateRowIndexDelete(pParse, pTab, baseCur, 0);
+          sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
+                                   regNewData, 1, 0, OE_Replace, 1, -1);
+        }else{
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+          if( HasRowid(pTab) ){
+            /* This OP_Delete opcode fires the pre-update-hook only. It does
+            ** not modify the b-tree. It is more efficient to let the coming
+            ** OP_Insert replace the existing entry than it is to delete the
+            ** existing entry and then insert a new one. */
+            sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
+            sqlite3VdbeChangeP4(v, -1, (char *)pTab, P4_TABLE);
+          }
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+          if( pTab->pIndex ){
+            sqlite3MultiWrite(pParse);
+            sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
+          }
         }
         seenReplace = 1;
         break;
       }
       case OE_Ignore: {
-        assert( seenReplace==0 );
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        /*assert( seenReplace==0 );*/
+        sqlite3VdbeGoto(v, ignoreDest);
         break;
       }
     }
-    sqlite3VdbeJumpHere(v, j3);
-    if( isUpdate ){
-      sqlite3VdbeJumpHere(v, j2);
+    sqlite3VdbeResolveLabel(v, addrRowidOk);
+    if( ipkTop ){
+      ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);
+      sqlite3VdbeJumpHere(v, ipkTop);
     }
   }
 
   /* Test all UNIQUE constraints by creating entries for each UNIQUE
   ** index and making sure that duplicate entries do not already exist.
-  ** Add the new records to the indices as we go.
-  */
-  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
-    int regIdx;
-    int regR;
-
-    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */
-
-    /* Create a key for accessing the index entry */
-    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
+  ** Compute the revised record entries for indices as we go.
+  **
+  ** This loop also handles the case of the PRIMARY KEY index for a
+  ** WITHOUT ROWID table.
+  */
+  for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
+    int regIdx;          /* Range of registers hold conent for pIdx */
+    int regR;            /* Range of registers holding conflicting PK */
+    int iThisCur;        /* Cursor for this UNIQUE index */
+    int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */
+
+    if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
+    if( bAffinityDone==0 ){
+      sqlite3TableAffinity(v, pTab, regNewData+1);
+      bAffinityDone = 1;
+    }
+    iThisCur = iIdxCur+ix;
+    addrUniqueOk = sqlite3VdbeMakeLabel(v);
+
+    /* Skip partial indices for which the WHERE clause is not true */
+    if( pIdx->pPartIdxWhere ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
+      pParse->ckBase = regNewData+1;
+      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
+                            SQLITE_JUMPIFNULL);
+      pParse->ckBase = 0;
+    }
+
+    /* Create a record for this index entry as it should appear after
+    ** the insert or update.  Store that record in the aRegIdx[ix] register
+    */
+    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
     for(i=0; i<pIdx->nColumn; i++){
-      int idx = pIdx->aiColumn[i];
-      if( idx==pTab->iPKey ){
-        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
+      int iField = pIdx->aiColumn[i];
+      int x;
+      if( iField==XN_EXPR ){
+        pParse->ckBase = regNewData+1;
+        sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
+        pParse->ckBase = 0;
+        VdbeComment((v, "%s column %d", pIdx->zName, i));
       }else{
-        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
+        if( iField==XN_ROWID || iField==pTab->iPKey ){
+          if( regRowid==regIdx+i ) continue; /* ROWID already in regIdx+i */
+          x = regNewData;
+          regRowid =  pIdx->pPartIdxWhere ? -1 : regIdx+i;
+        }else{
+          x = iField + regNewData + 1;
+        }
+        sqlite3VdbeAddOp2(v, iField<0 ? OP_IntCopy : OP_SCopy, x, regIdx+i);
+        VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
       }
     }
-    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
-    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
-    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
-    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
+    VdbeComment((v, "for %s", pIdx->zName));
+    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn);
 
-    /* Find out what action to take in case there is an indexing conflict */
+    /* In an UPDATE operation, if this index is the PRIMARY KEY index 
+    ** of a WITHOUT ROWID table and there has been no change the
+    ** primary key, then no collision is possible.  The collision detection
+    ** logic below can all be skipped. */
+    if( isUpdate && pPk==pIdx && pkChng==0 ){
+      sqlite3VdbeResolveLabel(v, addrUniqueOk);
+      continue;
+    }
+
+    /* Find out what action to take in case there is a uniqueness conflict */
     onError = pIdx->onError;
     if( onError==OE_None ){ 
-      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
+      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
+      sqlite3VdbeResolveLabel(v, addrUniqueOk);
       continue;  /* pIdx is not a UNIQUE index */
     }
     if( overrideError!=OE_Default ){
@@ -88544,18 +108012,66 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
     }else if( onError==OE_Default ){
       onError = OE_Abort;
     }
-    if( seenReplace ){
-      if( onError==OE_Ignore ) onError = OE_Replace;
-      else if( onError==OE_Fail ) onError = OE_Abort;
-    }
     
     /* Check to see if the new index entry will be unique */
-    regR = sqlite3GetTempReg(pParse);
-    sqlite3VdbeAddOp2(v, OP_SCopy, regOldRowid, regR);
-    j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0,
-                           regR, SQLITE_INT_TO_PTR(regIdx),
-                           P4_INT32);
-    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
+    sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
+                         regIdx, pIdx->nKeyCol); VdbeCoverage(v);
+
+    /* Generate code to handle collisions */
+    regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);
+    if( isUpdate || onError==OE_Replace ){
+      if( HasRowid(pTab) ){
+        sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
+        /* Conflict only if the rowid of the existing index entry
+        ** is different from old-rowid */
+        if( isUpdate ){
+          sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
+          sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
+          VdbeCoverage(v);
+        }
+      }else{
+        int x;
+        /* Extract the PRIMARY KEY from the end of the index entry and
+        ** store it in registers regR..regR+nPk-1 */
+        if( pIdx!=pPk ){
+          for(i=0; i<pPk->nKeyCol; i++){
+            assert( pPk->aiColumn[i]>=0 );
+            x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
+            sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
+            VdbeComment((v, "%s.%s", pTab->zName,
+                         pTab->aCol[pPk->aiColumn[i]].zName));
+          }
+        }
+        if( isUpdate ){
+          /* If currently processing the PRIMARY KEY of a WITHOUT ROWID 
+          ** table, only conflict if the new PRIMARY KEY values are actually
+          ** different from the old.
+          **
+          ** For a UNIQUE index, only conflict if the PRIMARY KEY values
+          ** of the matched index row are different from the original PRIMARY
+          ** KEY values of this row before the update.  */
+          int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
+          int op = OP_Ne;
+          int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
+  
+          for(i=0; i<pPk->nKeyCol; i++){
+            char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
+            x = pPk->aiColumn[i];
+            assert( x>=0 );
+            if( i==(pPk->nKeyCol-1) ){
+              addrJump = addrUniqueOk;
+              op = OP_Eq;
+            }
+            sqlite3VdbeAddOp4(v, op, 
+                regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
+            );
+            sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
+            VdbeCoverageIf(v, op==OP_Eq);
+            VdbeCoverageIf(v, op==OP_Ne);
+          }
+        }
+      }
+    }
 
     /* Generate code that executes if the new index entry is not unique */
     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
@@ -88564,59 +108080,44 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
       case OE_Rollback:
       case OE_Abort:
       case OE_Fail: {
-        int j;
-        StrAccum errMsg;
-        const char *zSep;
-        char *zErr;
-
-        sqlite3StrAccumInit(&errMsg, 0, 0, 200);
-        errMsg.db = pParse->db;
-        zSep = pIdx->nColumn>1 ? "columns " : "column ";
-        for(j=0; j<pIdx->nColumn; j++){
-          char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
-          sqlite3StrAccumAppend(&errMsg, zSep, -1);
-          zSep = ", ";
-          sqlite3StrAccumAppend(&errMsg, zCol, -1);
-        }
-        sqlite3StrAccumAppend(&errMsg,
-            pIdx->nColumn>1 ? " are not unique" : " is not unique", -1);
-        zErr = sqlite3StrAccumFinish(&errMsg);
-        sqlite3HaltConstraint(pParse, onError, zErr, 0);
-        sqlite3DbFree(errMsg.db, zErr);
+        sqlite3UniqueConstraint(pParse, onError, pIdx);
         break;
       }
       case OE_Ignore: {
-        assert( seenReplace==0 );
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
+        sqlite3VdbeGoto(v, ignoreDest);
         break;
       }
       default: {
         Trigger *pTrigger = 0;
         assert( onError==OE_Replace );
         sqlite3MultiWrite(pParse);
-        if( pParse->db->flags&SQLITE_RecTriggers ){
+        if( db->flags&SQLITE_RecTriggers ){
           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
         }
-        sqlite3GenerateRowDelete(
-            pParse, pTab, baseCur, regR, 0, pTrigger, OE_Replace
-        );
+        sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
+            regR, nPkField, 0, OE_Replace,
+            (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), -1);
         seenReplace = 1;
         break;
       }
     }
-    sqlite3VdbeJumpHere(v, j3);
-    sqlite3ReleaseTempReg(pParse, regR);
+    sqlite3VdbeResolveLabel(v, addrUniqueOk);
+    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
+    if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
   }
-  
-  if( pbMayReplace ){
-    *pbMayReplace = seenReplace;
+  if( ipkTop ){
+    sqlite3VdbeGoto(v, ipkTop+1);
+    sqlite3VdbeJumpHere(v, ipkBottom);
   }
+  
+  *pbMayReplace = seenReplace;
+  VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
 }
 
 /*
 ** This routine generates code to finish the INSERT or UPDATE operation
 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
-** A consecutive range of registers starting at regRowid contains the
+** A consecutive range of registers starting at regNewData contains the
 ** rowid and the content to be inserted.
 **
 ** The arguments to this routine should be the same as the first six
@@ -88625,36 +108126,46 @@ SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
 SQLITE_PRIVATE void sqlite3CompleteInsertion(
   Parse *pParse,      /* The parser context */
   Table *pTab,        /* the table into which we are inserting */
-  int baseCur,        /* Index of a read/write cursor pointing at pTab */
-  int regRowid,       /* Range of content */
+  int iDataCur,       /* Cursor of the canonical data source */
+  int iIdxCur,        /* First index cursor */
+  int regNewData,     /* Range of content */
   int *aRegIdx,       /* Register used by each index.  0 for unused indices */
   int isUpdate,       /* True for UPDATE, False for INSERT */
   int appendBias,     /* True if this is likely to be an append */
   int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
 ){
-  int i;
-  Vdbe *v;
-  int nIdx;
-  Index *pIdx;
-  u8 pik_flags;
-  int regData;
-  int regRec;
+  Vdbe *v;            /* Prepared statements under construction */
+  Index *pIdx;        /* An index being inserted or updated */
+  u8 pik_flags;       /* flag values passed to the btree insert */
+  int regData;        /* Content registers (after the rowid) */
+  int regRec;         /* Register holding assembled record for the table */
+  int i;              /* Loop counter */
+  u8 bAffinityDone = 0; /* True if OP_Affinity has been run already */
 
   v = sqlite3GetVdbe(pParse);
   assert( v!=0 );
   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
-  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
-  for(i=nIdx-1; i>=0; i--){
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
     if( aRegIdx[i]==0 ) continue;
-    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
-    if( useSeekResult ){
-      sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+    bAffinityDone = 1;
+    if( pIdx->pPartIdxWhere ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
+      VdbeCoverage(v);
     }
+    sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i]);
+    pik_flags = 0;
+    if( useSeekResult ) pik_flags = OPFLAG_USESEEKRESULT;
+    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
+      assert( pParse->nested==0 );
+      pik_flags |= OPFLAG_NCHANGE;
+    }
+    sqlite3VdbeChangeP5(v, pik_flags);
   }
-  regData = regRowid + 1;
+  if( !HasRowid(pTab) ) return;
+  regData = regNewData + 1;
   regRec = sqlite3GetTempReg(pParse);
   sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
-  sqlite3TableAffinityStr(v, pTab);
+  if( !bAffinityDone ) sqlite3TableAffinity(v, pTab, 0);
   sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
   if( pParse->nested ){
     pik_flags = 0;
@@ -88668,47 +108179,86 @@ SQLITE_PRIVATE void sqlite3CompleteInsertion(
   if( useSeekResult ){
     pik_flags |= OPFLAG_USESEEKRESULT;
   }
-  sqlite3VdbeAddOp3(v, OP_Insert, baseCur, regRec, regRowid);
+  sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, regRec, regNewData);
   if( !pParse->nested ){
-    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
+    sqlite3VdbeChangeP4(v, -1, (char *)pTab, P4_TABLE);
   }
   sqlite3VdbeChangeP5(v, pik_flags);
 }
 
 /*
-** Generate code that will open cursors for a table and for all
-** indices of that table.  The "baseCur" parameter is the cursor number used
-** for the table.  Indices are opened on subsequent cursors.
+** Allocate cursors for the pTab table and all its indices and generate
+** code to open and initialized those cursors.
+**
+** The cursor for the object that contains the complete data (normally
+** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
+** ROWID table) is returned in *piDataCur.  The first index cursor is
+** returned in *piIdxCur.  The number of indices is returned.
+**
+** Use iBase as the first cursor (either the *piDataCur for rowid tables
+** or the first index for WITHOUT ROWID tables) if it is non-negative.
+** If iBase is negative, then allocate the next available cursor.
 **
-** Return the number of indices on the table.
+** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
+** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
+** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
+** pTab->pIndex list.
+**
+** If pTab is a virtual table, then this routine is a no-op and the
+** *piDataCur and *piIdxCur values are left uninitialized.
 */
 SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
   Parse *pParse,   /* Parsing context */
   Table *pTab,     /* Table to be opened */
-  int baseCur,     /* Cursor number assigned to the table */
-  int op           /* OP_OpenRead or OP_OpenWrite */
+  int op,          /* OP_OpenRead or OP_OpenWrite */
+  u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
+  int iBase,       /* Use this for the table cursor, if there is one */
+  u8 *aToOpen,     /* If not NULL: boolean for each table and index */
+  int *piDataCur,  /* Write the database source cursor number here */
+  int *piIdxCur    /* Write the first index cursor number here */
 ){
   int i;
   int iDb;
+  int iDataCur;
   Index *pIdx;
   Vdbe *v;
 
-  if( IsVirtual(pTab) ) return 0;
+  assert( op==OP_OpenRead || op==OP_OpenWrite );
+  assert( op==OP_OpenWrite || p5==0 );
+  if( IsVirtual(pTab) ){
+    /* This routine is a no-op for virtual tables. Leave the output
+    ** variables *piDataCur and *piIdxCur uninitialized so that valgrind
+    ** can detect if they are used by mistake in the caller. */
+    return 0;
+  }
   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
   v = sqlite3GetVdbe(pParse);
   assert( v!=0 );
-  sqlite3OpenTable(pParse, baseCur, iDb, pTab, op);
-  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
-    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
-    assert( pIdx->pSchema==pTab->pSchema );
-    sqlite3VdbeAddOp4(v, op, i+baseCur, pIdx->tnum, iDb,
-                      (char*)pKey, P4_KEYINFO_HANDOFF);
-    VdbeComment((v, "%s", pIdx->zName));
+  if( iBase<0 ) iBase = pParse->nTab;
+  iDataCur = iBase++;
+  if( piDataCur ) *piDataCur = iDataCur;
+  if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){
+    sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);
+  }else{
+    sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
   }
-  if( pParse->nTab<baseCur+i ){
-    pParse->nTab = baseCur+i;
+  if( piIdxCur ) *piIdxCur = iBase;
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+    int iIdxCur = iBase++;
+    assert( pIdx->pSchema==pTab->pSchema );
+    if( aToOpen==0 || aToOpen[i+1] ){
+      sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
+      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+      VdbeComment((v, "%s", pIdx->zName));
+    }
+    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
+      if( piDataCur ) *piDataCur = iIdxCur;
+    }else{
+      sqlite3VdbeChangeP5(v, p5);
+    }
   }
-  return i-1;
+  if( iBase>pParse->nTab ) pParse->nTab = iBase;
+  return i;
 }
 
 
@@ -88717,7 +108267,7 @@ SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
 ** The following global variable is incremented whenever the
 ** transfer optimization is used.  This is used for testing
 ** purposes only - to make sure the transfer optimization really
-** is happening when it is suppose to.
+** is happening when it is supposed to.
 */
 SQLITE_API int sqlite3_xferopt_count;
 #endif /* SQLITE_TEST */
@@ -88725,20 +108275,6 @@ SQLITE_API int sqlite3_xferopt_count;
 
 #ifndef SQLITE_OMIT_XFER_OPT
 /*
-** Check to collation names to see if they are compatible.
-*/
-static int xferCompatibleCollation(const char *z1, const char *z2){
-  if( z1==0 ){
-    return z2==0;
-  }
-  if( z2==0 ){
-    return 0;
-  }
-  return sqlite3StrICmp(z1, z2)==0;
-}
-
-
-/*
 ** Check to see if index pSrc is compatible as a source of data
 ** for index pDest in an insert transfer optimization.  The rules
 ** for a compatible index:
@@ -88747,28 +108283,39 @@ static int xferCompatibleCollation(const char *z1, const char *z2){
 **    *   The same DESC and ASC markings occurs on all columns
 **    *   The same onError processing (OE_Abort, OE_Ignore, etc)
 **    *   The same collating sequence on each column
+**    *   The index has the exact same WHERE clause
 */
 static int xferCompatibleIndex(Index *pDest, Index *pSrc){
   int i;
   assert( pDest && pSrc );
   assert( pDest->pTable!=pSrc->pTable );
-  if( pDest->nColumn!=pSrc->nColumn ){
+  if( pDest->nKeyCol!=pSrc->nKeyCol ){
     return 0;   /* Different number of columns */
   }
   if( pDest->onError!=pSrc->onError ){
     return 0;   /* Different conflict resolution strategies */
   }
-  for(i=0; i<pSrc->nColumn; i++){
+  for(i=0; i<pSrc->nKeyCol; i++){
     if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
       return 0;   /* Different columns indexed */
     }
+    if( pSrc->aiColumn[i]==XN_EXPR ){
+      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
+      if( sqlite3ExprCompare(pSrc->aColExpr->a[i].pExpr,
+                             pDest->aColExpr->a[i].pExpr, -1)!=0 ){
+        return 0;   /* Different expressions in the index */
+      }
+    }
     if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
       return 0;   /* Different sort orders */
     }
-    if( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
+    if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
       return 0;   /* Different collating sequences */
     }
   }
+  if( sqlite3ExprCompare(pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
+    return 0;     /* Different WHERE clauses */
+  }
 
   /* If no test above fails then the indices must be compatible */
   return 1;
@@ -88779,31 +108326,25 @@ static int xferCompatibleIndex(Index *pDest, Index *pSrc){
 **
 **     INSERT INTO tab1 SELECT * FROM tab2;
 **
-** This optimization is only attempted if
+** The xfer optimization transfers raw records from tab2 over to tab1.  
+** Columns are not decoded and reassembled, which greatly improves
+** performance.  Raw index records are transferred in the same way.
 **
-**    (1)  tab1 and tab2 have identical schemas including all the
-**         same indices and constraints
+** The xfer optimization is only attempted if tab1 and tab2 are compatible.
+** There are lots of rules for determining compatibility - see comments
+** embedded in the code for details.
 **
-**    (2)  tab1 and tab2 are different tables
+** This routine returns TRUE if the optimization is guaranteed to be used.
+** Sometimes the xfer optimization will only work if the destination table
+** is empty - a factor that can only be determined at run-time.  In that
+** case, this routine generates code for the xfer optimization but also
+** does a test to see if the destination table is empty and jumps over the
+** xfer optimization code if the test fails.  In that case, this routine
+** returns FALSE so that the caller will know to go ahead and generate
+** an unoptimized transfer.  This routine also returns FALSE if there
+** is no chance that the xfer optimization can be applied.
 **
-**    (3)  There must be no triggers on tab1
-**
-**    (4)  The result set of the SELECT statement is "*"
-**
-**    (5)  The SELECT statement has no WHERE, HAVING, ORDER BY, GROUP BY,
-**         or LIMIT clause.
-**
-**    (6)  The SELECT statement is a simple (not a compound) select that
-**         contains only tab2 in its FROM clause
-**
-** This method for implementing the INSERT transfers raw records from
-** tab2 over to tab1.  The columns are not decoded.  Raw records from
-** the indices of tab2 are transfered to tab1 as well.  In so doing,
-** the resulting tab1 has much less fragmentation.
-**
-** This routine returns TRUE if the optimization is attempted.  If any
-** of the conditions above fail so that the optimization should not
-** be attempted, then this routine returns FALSE.
+** This optimization is particularly useful at making VACUUM run faster.
 */
 static int xferOptimization(
   Parse *pParse,        /* Parser context */
@@ -88812,6 +108353,7 @@ static int xferOptimization(
   int onError,          /* How to handle constraint errors */
   int iDbDest           /* The database of pDest */
 ){
+  sqlite3 *db = pParse->db;
   ExprList *pEList;                /* The result set of the SELECT */
   Table *pSrc;                     /* The table in the FROM clause of SELECT */
   Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
@@ -88820,10 +108362,9 @@ static int xferOptimization(
   int iDbSrc;                      /* The database of pSrc */
   int iSrc, iDest;                 /* Cursors from source and destination */
   int addr1, addr2;                /* Loop addresses */
-  int emptyDestTest;               /* Address of test for empty pDest */
-  int emptySrcTest;                /* Address of test for empty pSrc */
+  int emptyDestTest = 0;           /* Address of test for empty pDest */
+  int emptySrcTest = 0;            /* Address of test for empty pSrc */
   Vdbe *v;                         /* The VDBE we are building */
-  KeyInfo *pKey;                   /* Key information for an index */
   int regAutoinc;                  /* Memory register used by AUTOINC */
   int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
   int regData, regRowid;           /* Registers holding data and rowid */
@@ -88831,6 +108372,12 @@ static int xferOptimization(
   if( pSelect==0 ){
     return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
   }
+  if( pParse->pWith || pSelect->pWith ){
+    /* Do not attempt to process this query if there are an WITH clauses
+    ** attached to it. Proceeding may generate a false "no such table: xxx"
+    ** error if pSelect reads from a CTE named "xxx".  */
+    return 0;
+  }
   if( sqlite3TriggerList(pParse, pDest) ){
     return 0;   /* tab1 must not have triggers */
   }
@@ -88840,10 +108387,8 @@ static int xferOptimization(
   }
 #endif
   if( onError==OE_Default ){
-    onError = OE_Abort;
-  }
-  if( onError!=OE_Abort && onError!=OE_Rollback ){
-    return 0;   /* Cannot do OR REPLACE or OR IGNORE or OR FAIL */
+    if( pDest->iPKey>=0 ) onError = pDest->keyConf;
+    if( onError==OE_Default ) onError = OE_Abort;
   }
   assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
   if( pSelect->pSrc->nSrc!=1 ){
@@ -88879,7 +108424,7 @@ static int xferOptimization(
     return 0;   /* The result set must have exactly one column */
   }
   assert( pEList->a[0].pExpr );
-  if( pEList->a[0].pExpr->op!=TK_ALL ){
+  if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
     return 0;   /* The result set must be the special operator "*" */
   }
 
@@ -88888,13 +108433,16 @@ static int xferOptimization(
   ** we have to check the semantics.
   */
   pItem = pSelect->pSrc->a;
-  pSrc = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
+  pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
   if( pSrc==0 ){
     return 0;   /* FROM clause does not contain a real table */
   }
   if( pSrc==pDest ){
     return 0;   /* tab1 and tab2 may not be the same table */
   }
+  if( HasRowid(pDest)!=HasRowid(pSrc) ){
+    return 0;   /* source and destination must both be WITHOUT ROWID or not */
+  }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   if( pSrc->tabFlags & TF_Virtual ){
     return 0;   /* tab2 must not be a virtual table */
@@ -88910,18 +108458,38 @@ static int xferOptimization(
     return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
   }
   for(i=0; i<pDest->nCol; i++){
-    if( pDest->aCol[i].affinity!=pSrc->aCol[i].affinity ){
+    Column *pDestCol = &pDest->aCol[i];
+    Column *pSrcCol = &pSrc->aCol[i];
+#ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
+    if( (db->flags & SQLITE_Vacuum)==0 
+     && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN 
+    ){
+      return 0;    /* Neither table may have __hidden__ columns */
+    }
+#endif
+    if( pDestCol->affinity!=pSrcCol->affinity ){
       return 0;    /* Affinity must be the same on all columns */
     }
-    if( !xferCompatibleCollation(pDest->aCol[i].zColl, pSrc->aCol[i].zColl) ){
+    if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){
       return 0;    /* Collating sequence must be the same on all columns */
     }
-    if( pDest->aCol[i].notNull && !pSrc->aCol[i].notNull ){
+    if( pDestCol->notNull && !pSrcCol->notNull ){
       return 0;    /* tab2 must be NOT NULL if tab1 is */
     }
+    /* Default values for second and subsequent columns need to match. */
+    if( i>0 ){
+      assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );
+      assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );
+      if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0) 
+       || (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,
+                                       pSrcCol->pDflt->u.zToken)!=0)
+      ){
+        return 0;    /* Default values must be the same for all columns */
+      }
+    }
   }
   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
-    if( pDestIdx->onError!=OE_None ){
+    if( IsUniqueIndex(pDestIdx) ){
       destHasUniqueIdx = 1;
     }
     for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
@@ -88932,7 +108500,7 @@ static int xferOptimization(
     }
   }
 #ifndef SQLITE_OMIT_CHECK
-  if( pDest->pCheck && sqlite3ExprCompare(pSrc->pCheck, pDest->pCheck) ){
+  if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
     return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
   }
 #endif
@@ -88944,97 +108512,138 @@ static int xferOptimization(
   ** the extra complication to make this rule less restrictive is probably
   ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
   */
-  if( (pParse->db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
+  if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
     return 0;
   }
 #endif
-  if( (pParse->db->flags & SQLITE_CountRows)!=0 ){
-    return 0;
+  if( (db->flags & SQLITE_CountRows)!=0 ){
+    return 0;  /* xfer opt does not play well with PRAGMA count_changes */
   }
 
-  /* If we get this far, it means either:
-  **
-  **    *   We can always do the transfer if the table contains an
-  **        an integer primary key
-  **
-  **    *   We can conditionally do the transfer if the destination
-  **        table is empty.
+  /* If we get this far, it means that the xfer optimization is at
+  ** least a possibility, though it might only work if the destination
+  ** table (tab1) is initially empty.
   */
 #ifdef SQLITE_TEST
   sqlite3_xferopt_count++;
 #endif
-  iDbSrc = sqlite3SchemaToIndex(pParse->db, pSrc->pSchema);
+  iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
   v = sqlite3GetVdbe(pParse);
   sqlite3CodeVerifySchema(pParse, iDbSrc);
   iSrc = pParse->nTab++;
   iDest = pParse->nTab++;
   regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
+  regData = sqlite3GetTempReg(pParse);
+  regRowid = sqlite3GetTempReg(pParse);
   sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
-  if( (pDest->iPKey<0 && pDest->pIndex!=0) || destHasUniqueIdx ){
-    /* If tables do not have an INTEGER PRIMARY KEY and there
-    ** are indices to be copied and the destination is not empty,
-    ** we have to disallow the transfer optimization because the
-    ** the rowids might change which will mess up indexing.
+  assert( HasRowid(pDest) || destHasUniqueIdx );
+  if( (db->flags & SQLITE_Vacuum)==0 && (
+      (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
+   || destHasUniqueIdx                              /* (2) */
+   || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
+  )){
+    /* In some circumstances, we are able to run the xfer optimization
+    ** only if the destination table is initially empty. Unless the
+    ** SQLITE_Vacuum flag is set, this block generates code to make
+    ** that determination. If SQLITE_Vacuum is set, then the destination
+    ** table is always empty.
     **
-    ** Or if the destination has a UNIQUE index and is not empty,
-    ** we also disallow the transfer optimization because we cannot
-    ** insure that all entries in the union of DEST and SRC will be
-    ** unique.
+    ** Conditions under which the destination must be empty:
+    **
+    ** (1) There is no INTEGER PRIMARY KEY but there are indices.
+    **     (If the destination is not initially empty, the rowid fields
+    **     of index entries might need to change.)
+    **
+    ** (2) The destination has a unique index.  (The xfer optimization 
+    **     is unable to test uniqueness.)
+    **
+    ** (3) onError is something other than OE_Abort and OE_Rollback.
     */
-    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0);
-    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
+    emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
     sqlite3VdbeJumpHere(v, addr1);
-  }else{
-    emptyDestTest = 0;
   }
-  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
-  emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
-  regData = sqlite3GetTempReg(pParse);
-  regRowid = sqlite3GetTempReg(pParse);
-  if( pDest->iPKey>=0 ){
-    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
-    addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
-    sqlite3HaltConstraint(
-        pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
-    sqlite3VdbeJumpHere(v, addr2);
-    autoIncStep(pParse, regAutoinc, regRowid);
-  }else if( pDest->pIndex==0 ){
-    addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
+  if( HasRowid(pSrc) ){
+    sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
+    emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
+    if( pDest->iPKey>=0 ){
+      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
+      addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
+      VdbeCoverage(v);
+      sqlite3RowidConstraint(pParse, onError, pDest);
+      sqlite3VdbeJumpHere(v, addr2);
+      autoIncStep(pParse, regAutoinc, regRowid);
+    }else if( pDest->pIndex==0 ){
+      addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
+    }else{
+      addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
+      assert( (pDest->tabFlags & TF_Autoincrement)==0 );
+    }
+    sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
+    sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
+                      (char*)pDest, P4_TABLE);
+    sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
+    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
+    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
   }else{
-    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
-    assert( (pDest->tabFlags & TF_Autoincrement)==0 );
+    sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
+    sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
   }
-  sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
-  sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
-  sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
-  sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
-  sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
+    u8 idxInsFlags = 0;
     for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
     }
     assert( pSrcIdx );
-    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
-    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
-    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
-    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
-                      (char*)pKey, P4_KEYINFO_HANDOFF);
+    sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);
+    sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);
     VdbeComment((v, "%s", pSrcIdx->zName));
-    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
-    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
-                      (char*)pKey, P4_KEYINFO_HANDOFF);
+    sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);
+    sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);
+    sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
     VdbeComment((v, "%s", pDestIdx->zName));
-    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
     sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
+    if( db->flags & SQLITE_Vacuum ){
+      /* This INSERT command is part of a VACUUM operation, which guarantees
+      ** that the destination table is empty. If all indexed columns use
+      ** collation sequence BINARY, then it can also be assumed that the
+      ** index will be populated by inserting keys in strictly sorted 
+      ** order. In this case, instead of seeking within the b-tree as part
+      ** of every OP_IdxInsert opcode, an OP_Last is added before the
+      ** OP_IdxInsert to seek to the point within the b-tree where each key 
+      ** should be inserted. This is faster.
+      **
+      ** If any of the indexed columns use a collation sequence other than
+      ** BINARY, this optimization is disabled. This is because the user 
+      ** might change the definition of a collation sequence and then run
+      ** a VACUUM command. In that case keys may not be written in strictly
+      ** sorted order.  */
+      for(i=0; i<pSrcIdx->nColumn; i++){
+        const char *zColl = pSrcIdx->azColl[i];
+        assert( sqlite3_stricmp(sqlite3StrBINARY, zColl)!=0
+                    || sqlite3StrBINARY==zColl );
+        if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
+      }
+      if( i==pSrcIdx->nColumn ){
+        idxInsFlags = OPFLAG_USESEEKRESULT;
+        sqlite3VdbeAddOp3(v, OP_Last, iDest, 0, -1);
+      }
+    }
+    if( !HasRowid(pSrc) && pDestIdx->idxType==2 ){
+      idxInsFlags |= OPFLAG_NCHANGE;
+    }
     sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
-    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
+    sqlite3VdbeChangeP5(v, idxInsFlags);
+    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
     sqlite3VdbeJumpHere(v, addr1);
+    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
+    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
   }
-  sqlite3VdbeJumpHere(v, emptySrcTest);
+  if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);
   sqlite3ReleaseTempReg(pParse, regRowid);
   sqlite3ReleaseTempReg(pParse, regData);
-  sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
-  sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
   if( emptyDestTest ){
     sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
     sqlite3VdbeJumpHere(v, emptyDestTest);
@@ -89065,6 +108674,7 @@ static int xferOptimization(
 ** accessed by users of the library.
 */
 
+/* #include "sqliteInt.h" */
 
 /*
 ** Execute SQL code.  Return one of the SQLITE_ success/failure
@@ -89076,7 +108686,7 @@ static int xferOptimization(
 ** argument to xCallback().  If xCallback=NULL then no callback
 ** is invoked, even for queries.
 */
-SQLITE_API int sqlite3_exec(
+SQLITE_API int SQLITE_STDCALL sqlite3_exec(
   sqlite3 *db,                /* The database on which the SQL executes */
   const char *zSql,           /* The SQL to be executed */
   sqlite3_callback xCallback, /* Invoke this callback routine */
@@ -89087,20 +108697,19 @@ SQLITE_API int sqlite3_exec(
   const char *zLeftover;      /* Tail of unprocessed SQL */
   sqlite3_stmt *pStmt = 0;    /* The current SQL statement */
   char **azCols = 0;          /* Names of result columns */
-  int nRetry = 0;             /* Number of retry attempts */
   int callbackIsInit;         /* True if callback data is initialized */
 
   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
   if( zSql==0 ) zSql = "";
 
   sqlite3_mutex_enter(db->mutex);
-  sqlite3Error(db, SQLITE_OK, 0);
-  while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
+  sqlite3Error(db, SQLITE_OK);
+  while( rc==SQLITE_OK && zSql[0] ){
     int nCol;
     char **azVals = 0;
 
     pStmt = 0;
-    rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
+    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
     assert( rc==SQLITE_OK || pStmt==0 );
     if( rc!=SQLITE_OK ){
       continue;
@@ -89140,16 +108749,19 @@ SQLITE_API int sqlite3_exec(
           for(i=0; i<nCol; i++){
             azVals[i] = (char *)sqlite3_column_text(pStmt, i);
             if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
-              db->mallocFailed = 1;
+              sqlite3OomFault(db);
               goto exec_out;
             }
           }
         }
         if( xCallback(pArg, nCol, azVals, azCols) ){
+          /* EVIDENCE-OF: R-38229-40159 If the callback function to
+          ** sqlite3_exec() returns non-zero, then sqlite3_exec() will
+          ** return SQLITE_ABORT. */
           rc = SQLITE_ABORT;
           sqlite3VdbeFinalize((Vdbe *)pStmt);
           pStmt = 0;
-          sqlite3Error(db, SQLITE_ABORT, 0);
+          sqlite3Error(db, SQLITE_ABORT);
           goto exec_out;
         }
       }
@@ -89157,11 +108769,8 @@ SQLITE_API int sqlite3_exec(
       if( rc!=SQLITE_ROW ){
         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
         pStmt = 0;
-        if( rc!=SQLITE_SCHEMA ){
-          nRetry = 0;
-          zSql = zLeftover;
-          while( sqlite3Isspace(zSql[0]) ) zSql++;
-        }
+        zSql = zLeftover;
+        while( sqlite3Isspace(zSql[0]) ) zSql++;
         break;
       }
     }
@@ -89175,14 +108784,14 @@ exec_out:
   sqlite3DbFree(db, azCols);
 
   rc = sqlite3ApiExit(db, rc);
-  if( rc!=SQLITE_OK && ALWAYS(rc==sqlite3_errcode(db)) && pzErrMsg ){
+  if( rc!=SQLITE_OK && pzErrMsg ){
     int nErrMsg = 1 + sqlite3Strlen30(sqlite3_errmsg(db));
     *pzErrMsg = sqlite3Malloc(nErrMsg);
     if( *pzErrMsg ){
       memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
     }else{
-      rc = SQLITE_NOMEM;
-      sqlite3Error(db, SQLITE_NOMEM, 0);
+      rc = SQLITE_NOMEM_BKPT;
+      sqlite3Error(db, SQLITE_NOMEM);
     }
   }else if( pzErrMsg ){
     *pzErrMsg = 0;
@@ -89232,10 +108841,9 @@ exec_out:
 ** as extensions by SQLite should #include this file instead of 
 ** sqlite3.h.
 */
-#ifndef _SQLITE3EXT_H_
-#define _SQLITE3EXT_H_
-
-typedef struct sqlite3_api_routines sqlite3_api_routines;
+#ifndef SQLITE3EXT_H
+#define SQLITE3EXT_H
+/* #include "sqlite3.h" */
 
 /*
 ** The following structure holds pointers to all of the SQLite API
@@ -89244,7 +108852,7 @@ typedef struct sqlite3_api_routines sqlite3_api_routines;
 ** WARNING:  In order to maintain backwards compatibility, add new
 ** interfaces to the end of this structure only.  If you insert new
 ** interfaces in the middle of this structure, then older different
-** versions of SQLite will not be able to load each others' shared
+** versions of SQLite will not be able to load each other's shared
 ** libraries!
 */
 struct sqlite3_api_routines {
@@ -89452,11 +109060,69 @@ struct sqlite3_api_routines {
   int (*blob_reopen)(sqlite3_blob*,sqlite3_int64);
   int (*vtab_config)(sqlite3*,int op,...);
   int (*vtab_on_conflict)(sqlite3*);
+  /* Version 3.7.16 and later */
+  int (*close_v2)(sqlite3*);
+  const char *(*db_filename)(sqlite3*,const char*);
+  int (*db_readonly)(sqlite3*,const char*);
+  int (*db_release_memory)(sqlite3*);
+  const char *(*errstr)(int);
+  int (*stmt_busy)(sqlite3_stmt*);
+  int (*stmt_readonly)(sqlite3_stmt*);
+  int (*stricmp)(const char*,const char*);
+  int (*uri_boolean)(const char*,const char*,int);
+  sqlite3_int64 (*uri_int64)(const char*,const char*,sqlite3_int64);
+  const char *(*uri_parameter)(const char*,const char*);
+  char *(*vsnprintf)(int,char*,const char*,va_list);
+  int (*wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);
+  /* Version 3.8.7 and later */
+  int (*auto_extension)(void(*)(void));
+  int (*bind_blob64)(sqlite3_stmt*,int,const void*,sqlite3_uint64,
+                     void(*)(void*));
+  int (*bind_text64)(sqlite3_stmt*,int,const char*,sqlite3_uint64,
+                      void(*)(void*),unsigned char);
+  int (*cancel_auto_extension)(void(*)(void));
+  int (*load_extension)(sqlite3*,const char*,const char*,char**);
+  void *(*malloc64)(sqlite3_uint64);
+  sqlite3_uint64 (*msize)(void*);
+  void *(*realloc64)(void*,sqlite3_uint64);
+  void (*reset_auto_extension)(void);
+  void (*result_blob64)(sqlite3_context*,const void*,sqlite3_uint64,
+                        void(*)(void*));
+  void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
+                         void(*)(void*), unsigned char);
+  int (*strglob)(const char*,const char*);
+  /* Version 3.8.11 and later */
+  sqlite3_value *(*value_dup)(const sqlite3_value*);
+  void (*value_free)(sqlite3_value*);
+  int (*result_zeroblob64)(sqlite3_context*,sqlite3_uint64);
+  int (*bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);
+  /* Version 3.9.0 and later */
+  unsigned int (*value_subtype)(sqlite3_value*);
+  void (*result_subtype)(sqlite3_context*,unsigned int);
+  /* Version 3.10.0 and later */
+  int (*status64)(int,sqlite3_int64*,sqlite3_int64*,int);
+  int (*strlike)(const char*,const char*,unsigned int);
+  int (*db_cacheflush)(sqlite3*);
+  /* Version 3.12.0 and later */
+  int (*system_errno)(sqlite3*);
+  /* Version 3.14.0 and later */
+  int (*trace_v2)(sqlite3*,unsigned,int(*)(unsigned,void*,void*,void*),void*);
+  char *(*expanded_sql)(sqlite3_stmt*);
 };
 
 /*
+** This is the function signature used for all extension entry points.  It
+** is also defined in the file "loadext.c".
+*/
+typedef int (*sqlite3_loadext_entry)(
+  sqlite3 *db,                       /* Handle to the database. */
+  char **pzErrMsg,                   /* Used to set error string on failure. */
+  const sqlite3_api_routines *pThunk /* Extension API function pointers. */
+);
+
+/*
 ** The following macros redefine the API routines so that they are
-** redirected throught the global sqlite3_api structure.
+** redirected through the global sqlite3_api structure.
 **
 ** This header file is also used by the loadext.c source file
 ** (part of the main SQLite library - not an extension) so that
@@ -89465,7 +109131,7 @@ struct sqlite3_api_routines {
 ** the API.  So the redefinition macros are only valid if the
 ** SQLITE_CORE macros is undefined.
 */
-#ifndef SQLITE_CORE
+#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
 #define sqlite3_aggregate_context      sqlite3_api->aggregate_context
 #ifndef SQLITE_OMIT_DEPRECATED
 #define sqlite3_aggregate_count        sqlite3_api->aggregate_count
@@ -89592,6 +109258,7 @@ struct sqlite3_api_routines {
 #define sqlite3_value_text16le         sqlite3_api->value_text16le
 #define sqlite3_value_type             sqlite3_api->value_type
 #define sqlite3_vmprintf               sqlite3_api->vmprintf
+#define sqlite3_vsnprintf              sqlite3_api->vsnprintf
 #define sqlite3_overload_function      sqlite3_api->overload_function
 #define sqlite3_prepare_v2             sqlite3_api->prepare_v2
 #define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2
@@ -89655,19 +109322,75 @@ struct sqlite3_api_routines {
 #define sqlite3_blob_reopen            sqlite3_api->blob_reopen
 #define sqlite3_vtab_config            sqlite3_api->vtab_config
 #define sqlite3_vtab_on_conflict       sqlite3_api->vtab_on_conflict
-#endif /* SQLITE_CORE */
-
-#define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api = 0;
-#define SQLITE_EXTENSION_INIT2(v)  sqlite3_api = v;
+/* Version 3.7.16 and later */
+#define sqlite3_close_v2               sqlite3_api->close_v2
+#define sqlite3_db_filename            sqlite3_api->db_filename
+#define sqlite3_db_readonly            sqlite3_api->db_readonly
+#define sqlite3_db_release_memory      sqlite3_api->db_release_memory
+#define sqlite3_errstr                 sqlite3_api->errstr
+#define sqlite3_stmt_busy              sqlite3_api->stmt_busy
+#define sqlite3_stmt_readonly          sqlite3_api->stmt_readonly
+#define sqlite3_stricmp                sqlite3_api->stricmp
+#define sqlite3_uri_boolean            sqlite3_api->uri_boolean
+#define sqlite3_uri_int64              sqlite3_api->uri_int64
+#define sqlite3_uri_parameter          sqlite3_api->uri_parameter
+#define sqlite3_uri_vsnprintf          sqlite3_api->vsnprintf
+#define sqlite3_wal_checkpoint_v2      sqlite3_api->wal_checkpoint_v2
+/* Version 3.8.7 and later */
+#define sqlite3_auto_extension         sqlite3_api->auto_extension
+#define sqlite3_bind_blob64            sqlite3_api->bind_blob64
+#define sqlite3_bind_text64            sqlite3_api->bind_text64
+#define sqlite3_cancel_auto_extension  sqlite3_api->cancel_auto_extension
+#define sqlite3_load_extension         sqlite3_api->load_extension
+#define sqlite3_malloc64               sqlite3_api->malloc64
+#define sqlite3_msize                  sqlite3_api->msize
+#define sqlite3_realloc64              sqlite3_api->realloc64
+#define sqlite3_reset_auto_extension   sqlite3_api->reset_auto_extension
+#define sqlite3_result_blob64          sqlite3_api->result_blob64
+#define sqlite3_result_text64          sqlite3_api->result_text64
+#define sqlite3_strglob                sqlite3_api->strglob
+/* Version 3.8.11 and later */
+#define sqlite3_value_dup              sqlite3_api->value_dup
+#define sqlite3_value_free             sqlite3_api->value_free
+#define sqlite3_result_zeroblob64      sqlite3_api->result_zeroblob64
+#define sqlite3_bind_zeroblob64        sqlite3_api->bind_zeroblob64
+/* Version 3.9.0 and later */
+#define sqlite3_value_subtype          sqlite3_api->value_subtype
+#define sqlite3_result_subtype         sqlite3_api->result_subtype
+/* Version 3.10.0 and later */
+#define sqlite3_status64               sqlite3_api->status64
+#define sqlite3_strlike                sqlite3_api->strlike
+#define sqlite3_db_cacheflush          sqlite3_api->db_cacheflush
+/* Version 3.12.0 and later */
+#define sqlite3_system_errno           sqlite3_api->system_errno
+/* Version 3.14.0 and later */
+#define sqlite3_trace_v2               sqlite3_api->trace_v2
+#define sqlite3_expanded_sql           sqlite3_api->expanded_sql
+#endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */
+
+#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
+  /* This case when the file really is being compiled as a loadable 
+  ** extension */
+# define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
+# define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;
+# define SQLITE_EXTENSION_INIT3     \
+    extern const sqlite3_api_routines *sqlite3_api;
+#else
+  /* This case when the file is being statically linked into the 
+  ** application */
+# define SQLITE_EXTENSION_INIT1     /*no-op*/
+# define SQLITE_EXTENSION_INIT2(v)  (void)v; /* unused parameter */
+# define SQLITE_EXTENSION_INIT3     /*no-op*/
+#endif
 
-#endif /* _SQLITE3EXT_H_ */
+#endif /* SQLITE3EXT_H */
 
 /************** End of sqlite3ext.h ******************************************/
 /************** Continuing where we left off in loadext.c ********************/
+/* #include "sqliteInt.h" */
 /* #include <string.h> */
 
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
-
 /*
 ** Some API routines are omitted when various features are
 ** excluded from a build of SQLite.  Substitute a NULL pointer
@@ -89680,7 +109403,6 @@ struct sqlite3_api_routines {
 # define sqlite3_column_table_name16    0
 # define sqlite3_column_origin_name     0
 # define sqlite3_column_origin_name16   0
-# define sqlite3_table_column_metadata  0
 #endif
 
 #ifdef SQLITE_OMIT_AUTHORIZATION
@@ -89738,7 +109460,7 @@ struct sqlite3_api_routines {
 # define sqlite3_enable_shared_cache 0
 #endif
 
-#ifdef SQLITE_OMIT_TRACE
+#if defined(SQLITE_OMIT_TRACE) || defined(SQLITE_OMIT_DEPRECATED)
 # define sqlite3_profile       0
 # define sqlite3_trace         0
 #endif
@@ -89758,6 +109480,10 @@ struct sqlite3_api_routines {
 #define sqlite3_blob_reopen    0
 #endif
 
+#if defined(SQLITE_OMIT_TRACE)
+# define sqlite3_trace_v2      0
+#endif
+
 /*
 ** The following structure contains pointers to all SQLite API routines.
 ** A pointer to this structure is passed into extensions when they are
@@ -90024,6 +109750,49 @@ static const sqlite3_api_routines sqlite3Apis = {
   sqlite3_blob_reopen,
   sqlite3_vtab_config,
   sqlite3_vtab_on_conflict,
+  sqlite3_close_v2,
+  sqlite3_db_filename,
+  sqlite3_db_readonly,
+  sqlite3_db_release_memory,
+  sqlite3_errstr,
+  sqlite3_stmt_busy,
+  sqlite3_stmt_readonly,
+  sqlite3_stricmp,
+  sqlite3_uri_boolean,
+  sqlite3_uri_int64,
+  sqlite3_uri_parameter,
+  sqlite3_vsnprintf,
+  sqlite3_wal_checkpoint_v2,
+  /* Version 3.8.7 and later */
+  sqlite3_auto_extension,
+  sqlite3_bind_blob64,
+  sqlite3_bind_text64,
+  sqlite3_cancel_auto_extension,
+  sqlite3_load_extension,
+  sqlite3_malloc64,
+  sqlite3_msize,
+  sqlite3_realloc64,
+  sqlite3_reset_auto_extension,
+  sqlite3_result_blob64,
+  sqlite3_result_text64,
+  sqlite3_strglob,
+  /* Version 3.8.11 and later */
+  (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
+  sqlite3_value_free,
+  sqlite3_result_zeroblob64,
+  sqlite3_bind_zeroblob64,
+  /* Version 3.9.0 and later */
+  sqlite3_value_subtype,
+  sqlite3_result_subtype,
+  /* Version 3.10.0 and later */
+  sqlite3_status64,
+  sqlite3_strlike,
+  sqlite3_db_cacheflush,
+  /* Version 3.12.0 and later */
+  sqlite3_system_errno,
+  /* Version 3.14.0 and later */
+  sqlite3_trace_v2,
+  sqlite3_expanded_sql
 };
 
 /*
@@ -90046,18 +109815,35 @@ static int sqlite3LoadExtension(
 ){
   sqlite3_vfs *pVfs = db->pVfs;
   void *handle;
-  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  sqlite3_loadext_entry xInit;
   char *zErrmsg = 0;
+  const char *zEntry;
+  char *zAltEntry = 0;
   void **aHandle;
-  int nMsg = 300 + sqlite3Strlen30(zFile);
+  u64 nMsg = 300 + sqlite3Strlen30(zFile);
+  int ii;
+  int rc;
+
+  /* Shared library endings to try if zFile cannot be loaded as written */
+  static const char *azEndings[] = {
+#if SQLITE_OS_WIN
+     "dll"   
+#elif defined(__APPLE__)
+     "dylib"
+#else
+     "so"
+#endif
+  };
+
 
   if( pzErrMsg ) *pzErrMsg = 0;
 
   /* Ticket #1863.  To avoid a creating security problems for older
   ** applications that relink against newer versions of SQLite, the
   ** ability to run load_extension is turned off by default.  One
-  ** must call sqlite3_enable_load_extension() to turn on extension
-  ** loading.  Otherwise you get the following error.
+  ** must call either sqlite3_enable_load_extension(db) or
+  ** sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, 0)
+  ** to turn on extension loading.
   */
   if( (db->flags & SQLITE_LoadExtension)==0 ){
     if( pzErrMsg ){
@@ -90066,14 +109852,20 @@ static int sqlite3LoadExtension(
     return SQLITE_ERROR;
   }
 
-  if( zProc==0 ){
-    zProc = "sqlite3_extension_init";
-  }
+  zEntry = zProc ? zProc : "sqlite3_extension_init";
 
   handle = sqlite3OsDlOpen(pVfs, zFile);
+#if SQLITE_OS_UNIX || SQLITE_OS_WIN
+  for(ii=0; ii<ArraySize(azEndings) && handle==0; ii++){
+    char *zAltFile = sqlite3_mprintf("%s.%s", zFile, azEndings[ii]);
+    if( zAltFile==0 ) return SQLITE_NOMEM_BKPT;
+    handle = sqlite3OsDlOpen(pVfs, zAltFile);
+    sqlite3_free(zAltFile);
+  }
+#endif
   if( handle==0 ){
     if( pzErrMsg ){
-      *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
+      *pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);
       if( zErrmsg ){
         sqlite3_snprintf(nMsg, zErrmsg, 
             "unable to open shared library [%s]", zFile);
@@ -90082,21 +109874,58 @@ static int sqlite3LoadExtension(
     }
     return SQLITE_ERROR;
   }
-  xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
-                   sqlite3OsDlSym(pVfs, handle, zProc);
+  xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);
+
+  /* If no entry point was specified and the default legacy
+  ** entry point name "sqlite3_extension_init" was not found, then
+  ** construct an entry point name "sqlite3_X_init" where the X is
+  ** replaced by the lowercase value of every ASCII alphabetic 
+  ** character in the filename after the last "/" upto the first ".",
+  ** and eliding the first three characters if they are "lib".  
+  ** Examples:
+  **
+  **    /usr/local/lib/libExample5.4.3.so ==>  sqlite3_example_init
+  **    C:/lib/mathfuncs.dll              ==>  sqlite3_mathfuncs_init
+  */
+  if( xInit==0 && zProc==0 ){
+    int iFile, iEntry, c;
+    int ncFile = sqlite3Strlen30(zFile);
+    zAltEntry = sqlite3_malloc64(ncFile+30);
+    if( zAltEntry==0 ){
+      sqlite3OsDlClose(pVfs, handle);
+      return SQLITE_NOMEM_BKPT;
+    }
+    memcpy(zAltEntry, "sqlite3_", 8);
+    for(iFile=ncFile-1; iFile>=0 && zFile[iFile]!='/'; iFile--){}
+    iFile++;
+    if( sqlite3_strnicmp(zFile+iFile, "lib", 3)==0 ) iFile += 3;
+    for(iEntry=8; (c = zFile[iFile])!=0 && c!='.'; iFile++){
+      if( sqlite3Isalpha(c) ){
+        zAltEntry[iEntry++] = (char)sqlite3UpperToLower[(unsigned)c];
+      }
+    }
+    memcpy(zAltEntry+iEntry, "_init", 6);
+    zEntry = zAltEntry;
+    xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);
+  }
   if( xInit==0 ){
     if( pzErrMsg ){
-      nMsg += sqlite3Strlen30(zProc);
-      *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
+      nMsg += sqlite3Strlen30(zEntry);
+      *pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);
       if( zErrmsg ){
         sqlite3_snprintf(nMsg, zErrmsg,
-            "no entry point [%s] in shared library [%s]", zProc,zFile);
+            "no entry point [%s] in shared library [%s]", zEntry, zFile);
         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
       }
-      sqlite3OsDlClose(pVfs, handle);
     }
+    sqlite3OsDlClose(pVfs, handle);
+    sqlite3_free(zAltEntry);
     return SQLITE_ERROR;
-  }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
+  }
+  sqlite3_free(zAltEntry);
+  rc = xInit(db, &zErrmsg, &sqlite3Apis);
+  if( rc ){
+    if( rc==SQLITE_OK_LOAD_PERMANENTLY ) return SQLITE_OK;
     if( pzErrMsg ){
       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
     }
@@ -90108,7 +109937,7 @@ static int sqlite3LoadExtension(
   /* Append the new shared library handle to the db->aExtension array. */
   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
   if( aHandle==0 ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   if( db->nExtension>0 ){
     memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
@@ -90119,7 +109948,7 @@ static int sqlite3LoadExtension(
   db->aExtension[db->nExtension++] = handle;
   return SQLITE_OK;
 }
-SQLITE_API int sqlite3_load_extension(
+SQLITE_API int SQLITE_STDCALL sqlite3_load_extension(
   sqlite3 *db,          /* Load the extension into this database connection */
   const char *zFile,    /* Name of the shared library containing extension */
   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
@@ -90150,12 +109979,12 @@ SQLITE_PRIVATE void sqlite3CloseExtensions(sqlite3 *db){
 ** Enable or disable extension loading.  Extension loading is disabled by
 ** default so as not to open security holes in older applications.
 */
-SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
+SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff){
   sqlite3_mutex_enter(db->mutex);
   if( onoff ){
-    db->flags |= SQLITE_LoadExtension;
+    db->flags |= SQLITE_LoadExtension|SQLITE_LoadExtFunc;
   }else{
-    db->flags &= ~SQLITE_LoadExtension;
+    db->flags &= ~(SQLITE_LoadExtension|SQLITE_LoadExtFunc);
   }
   sqlite3_mutex_leave(db->mutex);
   return SQLITE_OK;
@@ -90183,7 +110012,7 @@ static const sqlite3_api_routines sqlite3Apis = { 0 };
 */
 typedef struct sqlite3AutoExtList sqlite3AutoExtList;
 static SQLITE_WSD struct sqlite3AutoExtList {
-  int nExt;              /* Number of entries in aExt[] */          
+  u32 nExt;              /* Number of entries in aExt[] */          
   void (**aExt)(void);   /* Pointers to the extension init functions */
 } sqlite3Autoext = { 0, 0 };
 
@@ -90207,7 +110036,9 @@ static SQLITE_WSD struct sqlite3AutoExtList {
 ** Register a statically linked extension that is automatically
 ** loaded by every new database connection.
 */
-SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
+SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(
+  void (*xInit)(void)
+){
   int rc = SQLITE_OK;
 #ifndef SQLITE_OMIT_AUTOINIT
   rc = sqlite3_initialize();
@@ -90216,7 +110047,7 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
   }else
 #endif
   {
-    int i;
+    u32 i;
 #if SQLITE_THREADSAFE
     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
 #endif
@@ -90226,11 +110057,11 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
       if( wsdAutoext.aExt[i]==xInit ) break;
     }
     if( i==wsdAutoext.nExt ){
-      int nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
+      u64 nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
       void (**aNew)(void);
-      aNew = sqlite3_realloc(wsdAutoext.aExt, nByte);
+      aNew = sqlite3_realloc64(wsdAutoext.aExt, nByte);
       if( aNew==0 ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
       }else{
         wsdAutoext.aExt = aNew;
         wsdAutoext.aExt[wsdAutoext.nExt] = xInit;
@@ -90244,9 +110075,40 @@ SQLITE_API int sqlite3_auto_extension(void (*xInit)(void)){
 }
 
 /*
+** Cancel a prior call to sqlite3_auto_extension.  Remove xInit from the
+** set of routines that is invoked for each new database connection, if it
+** is currently on the list.  If xInit is not on the list, then this
+** routine is a no-op.
+**
+** Return 1 if xInit was found on the list and removed.  Return 0 if xInit
+** was not on the list.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(
+  void (*xInit)(void)
+){
+#if SQLITE_THREADSAFE
+  sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
+#endif
+  int i;
+  int n = 0;
+  wsdAutoextInit;
+  sqlite3_mutex_enter(mutex);
+  for(i=(int)wsdAutoext.nExt-1; i>=0; i--){
+    if( wsdAutoext.aExt[i]==xInit ){
+      wsdAutoext.nExt--;
+      wsdAutoext.aExt[i] = wsdAutoext.aExt[wsdAutoext.nExt];
+      n++;
+      break;
+    }
+  }
+  sqlite3_mutex_leave(mutex);
+  return n;
+}
+
+/*
 ** Reset the automatic extension loading mechanism.
 */
-SQLITE_API void sqlite3_reset_auto_extension(void){
+SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void){
 #ifndef SQLITE_OMIT_AUTOINIT
   if( sqlite3_initialize()==SQLITE_OK )
 #endif
@@ -90269,9 +110131,10 @@ SQLITE_API void sqlite3_reset_auto_extension(void){
 ** If anything goes wrong, set an error in the database connection.
 */
 SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
-  int i;
+  u32 i;
   int go = 1;
-  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
+  int rc;
+  sqlite3_loadext_entry xInit;
 
   wsdAutoextInit;
   if( wsdAutoext.nExt==0 ){
@@ -90288,13 +110151,12 @@ SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
       xInit = 0;
       go = 0;
     }else{
-      xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
-              wsdAutoext.aExt[i];
+      xInit = (sqlite3_loadext_entry)wsdAutoext.aExt[i];
     }
     sqlite3_mutex_leave(mutex);
     zErrmsg = 0;
-    if( xInit && xInit(db, &zErrmsg, &sqlite3Apis) ){
-      sqlite3Error(db, SQLITE_ERROR,
+    if( xInit && (rc = xInit(db, &zErrmsg, &sqlite3Apis))!=0 ){
+      sqlite3ErrorWithMsg(db, rc,
             "automatic extension loading failed: %s", zErrmsg);
       go = 0;
     }
@@ -90317,41 +110179,531 @@ SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
 *************************************************************************
 ** This file contains code used to implement the PRAGMA command.
 */
+/* #include "sqliteInt.h" */
+
+#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
+#  if defined(__APPLE__)
+#    define SQLITE_ENABLE_LOCKING_STYLE 1
+#  else
+#    define SQLITE_ENABLE_LOCKING_STYLE 0
+#  endif
+#endif
+
+/***************************************************************************
+** The "pragma.h" include file is an automatically generated file that
+** that includes the PragType_XXXX macro definitions and the aPragmaName[]
+** object.  This ensures that the aPragmaName[] table is arranged in
+** lexicographical order to facility a binary search of the pragma name.
+** Do not edit pragma.h directly.  Edit and rerun the script in at 
+** ../tool/mkpragmatab.tcl. */
+/************** Include pragma.h in the middle of pragma.c *******************/
+/************** Begin file pragma.h ******************************************/
+/* DO NOT EDIT!
+** This file is automatically generated by the script at
+** ../tool/mkpragmatab.tcl.  To update the set of pragmas, edit
+** that script and rerun it.
+*/
+#define PragTyp_HEADER_VALUE                   0
+#define PragTyp_AUTO_VACUUM                    1
+#define PragTyp_FLAG                           2
+#define PragTyp_BUSY_TIMEOUT                   3
+#define PragTyp_CACHE_SIZE                     4
+#define PragTyp_CACHE_SPILL                    5
+#define PragTyp_CASE_SENSITIVE_LIKE            6
+#define PragTyp_COLLATION_LIST                 7
+#define PragTyp_COMPILE_OPTIONS                8
+#define PragTyp_DATA_STORE_DIRECTORY           9
+#define PragTyp_DATABASE_LIST                 10
+#define PragTyp_DEFAULT_CACHE_SIZE            11
+#define PragTyp_ENCODING                      12
+#define PragTyp_FOREIGN_KEY_CHECK             13
+#define PragTyp_FOREIGN_KEY_LIST              14
+#define PragTyp_INCREMENTAL_VACUUM            15
+#define PragTyp_INDEX_INFO                    16
+#define PragTyp_INDEX_LIST                    17
+#define PragTyp_INTEGRITY_CHECK               18
+#define PragTyp_JOURNAL_MODE                  19
+#define PragTyp_JOURNAL_SIZE_LIMIT            20
+#define PragTyp_LOCK_PROXY_FILE               21
+#define PragTyp_LOCKING_MODE                  22
+#define PragTyp_PAGE_COUNT                    23
+#define PragTyp_MMAP_SIZE                     24
+#define PragTyp_PAGE_SIZE                     25
+#define PragTyp_SECURE_DELETE                 26
+#define PragTyp_SHRINK_MEMORY                 27
+#define PragTyp_SOFT_HEAP_LIMIT               28
+#define PragTyp_STATS                         29
+#define PragTyp_SYNCHRONOUS                   30
+#define PragTyp_TABLE_INFO                    31
+#define PragTyp_TEMP_STORE                    32
+#define PragTyp_TEMP_STORE_DIRECTORY          33
+#define PragTyp_THREADS                       34
+#define PragTyp_WAL_AUTOCHECKPOINT            35
+#define PragTyp_WAL_CHECKPOINT                36
+#define PragTyp_ACTIVATE_EXTENSIONS           37
+#define PragTyp_HEXKEY                        38
+#define PragTyp_KEY                           39
+#define PragTyp_REKEY                         40
+#define PragTyp_LOCK_STATUS                   41
+#define PragTyp_PARSER_TRACE                  42
+#define PragFlag_NeedSchema           0x01
+#define PragFlag_ReadOnly             0x02
+static const struct sPragmaNames {
+  const char *const zName;  /* Name of pragma */
+  u8 ePragTyp;              /* PragTyp_XXX value */
+  u8 mPragFlag;             /* Zero or more PragFlag_XXX values */
+  u32 iArg;                 /* Extra argument */
+} aPragmaNames[] = {
+#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
+  { /* zName:     */ "activate_extensions",
+    /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
+  { /* zName:     */ "application_id",
+    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ BTREE_APPLICATION_ID },
+#endif
+#if !defined(SQLITE_OMIT_AUTOVACUUM)
+  { /* zName:     */ "auto_vacuum",
+    /* ePragTyp:  */ PragTyp_AUTO_VACUUM,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)
+  { /* zName:     */ "automatic_index",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_AutoIndex },
+#endif
+#endif
+  { /* zName:     */ "busy_timeout",
+    /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "cache_size",
+    /* ePragTyp:  */ PragTyp_CACHE_SIZE,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "cache_spill",
+    /* ePragTyp:  */ PragTyp_CACHE_SPILL,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+  { /* zName:     */ "case_sensitive_like",
+    /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "cell_size_check",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_CellSizeCk },
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "checkpoint_fullfsync",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_CkptFullFSync },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+  { /* zName:     */ "collation_list",
+    /* ePragTyp:  */ PragTyp_COLLATION_LIST,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)
+  { /* zName:     */ "compile_options",
+    /* ePragTyp:  */ PragTyp_COMPILE_OPTIONS,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "count_changes",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_CountRows },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN
+  { /* zName:     */ "data_store_directory",
+    /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
+  { /* zName:     */ "data_version",
+    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+    /* ePragFlag: */ PragFlag_ReadOnly,
+    /* iArg:      */ BTREE_DATA_VERSION },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+  { /* zName:     */ "database_list",
+    /* ePragTyp:  */ PragTyp_DATABASE_LIST,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
+  { /* zName:     */ "default_cache_size",
+    /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+  { /* zName:     */ "defer_foreign_keys",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_DeferFKs },
+#endif
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "empty_result_callbacks",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_NullCallback },
+#endif
+#if !defined(SQLITE_OMIT_UTF16)
+  { /* zName:     */ "encoding",
+    /* ePragTyp:  */ PragTyp_ENCODING,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+  { /* zName:     */ "foreign_key_check",
+    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_CHECK,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FOREIGN_KEY)
+  { /* zName:     */ "foreign_key_list",
+    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
+  { /* zName:     */ "foreign_keys",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_ForeignKeys },
+#endif
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
+  { /* zName:     */ "freelist_count",
+    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+    /* ePragFlag: */ PragFlag_ReadOnly,
+    /* iArg:      */ BTREE_FREE_PAGE_COUNT },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "full_column_names",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_FullColNames },
+  { /* zName:     */ "fullfsync",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_FullFSync },
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  { /* zName:     */ "hexkey",
+    /* ePragTyp:  */ PragTyp_HEXKEY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "hexrekey",
+    /* ePragTyp:  */ PragTyp_HEXKEY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if !defined(SQLITE_OMIT_CHECK)
+  { /* zName:     */ "ignore_check_constraints",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_IgnoreChecks },
+#endif
+#endif
+#if !defined(SQLITE_OMIT_AUTOVACUUM)
+  { /* zName:     */ "incremental_vacuum",
+    /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+  { /* zName:     */ "index_info",
+    /* ePragTyp:  */ PragTyp_INDEX_INFO,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "index_list",
+    /* ePragTyp:  */ PragTyp_INDEX_LIST,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "index_xinfo",
+    /* ePragTyp:  */ PragTyp_INDEX_INFO,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 1 },
+#endif
+#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
+  { /* zName:     */ "integrity_check",
+    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "journal_mode",
+    /* ePragTyp:  */ PragTyp_JOURNAL_MODE,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "journal_size_limit",
+    /* ePragTyp:  */ PragTyp_JOURNAL_SIZE_LIMIT,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  { /* zName:     */ "key",
+    /* ePragTyp:  */ PragTyp_KEY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "legacy_file_format",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_LegacyFileFmt },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
+  { /* zName:     */ "lock_proxy_file",
+    /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
+  { /* zName:     */ "lock_status",
+    /* ePragTyp:  */ PragTyp_LOCK_STATUS,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "locking_mode",
+    /* ePragTyp:  */ PragTyp_LOCKING_MODE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "max_page_count",
+    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "mmap_size",
+    /* ePragTyp:  */ PragTyp_MMAP_SIZE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "page_count",
+    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "page_size",
+    /* ePragTyp:  */ PragTyp_PAGE_SIZE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_PARSER_TRACE)
+  { /* zName:     */ "parser_trace",
+    /* ePragTyp:  */ PragTyp_PARSER_TRACE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "query_only",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_QueryOnly },
+#endif
+#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
+  { /* zName:     */ "quick_check",
+    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "read_uncommitted",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_ReadUncommitted },
+  { /* zName:     */ "recursive_triggers",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_RecTriggers },
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  { /* zName:     */ "rekey",
+    /* ePragTyp:  */ PragTyp_REKEY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "reverse_unordered_selects",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_ReverseOrder },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
+  { /* zName:     */ "schema_version",
+    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ BTREE_SCHEMA_VERSION },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "secure_delete",
+    /* ePragTyp:  */ PragTyp_SECURE_DELETE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "short_column_names",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_ShortColNames },
+#endif
+  { /* zName:     */ "shrink_memory",
+    /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "soft_heap_limit",
+    /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if defined(SQLITE_DEBUG)
+  { /* zName:     */ "sql_trace",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_SqlTrace },
+#endif
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+  { /* zName:     */ "stats",
+    /* ePragTyp:  */ PragTyp_STATS,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "synchronous",
+    /* ePragTyp:  */ PragTyp_SYNCHRONOUS,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
+  { /* zName:     */ "table_info",
+    /* ePragTyp:  */ PragTyp_TABLE_INFO,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
+  { /* zName:     */ "temp_store",
+    /* ePragTyp:  */ PragTyp_TEMP_STORE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "temp_store_directory",
+    /* ePragTyp:  */ PragTyp_TEMP_STORE_DIRECTORY,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#endif
+  { /* zName:     */ "threads",
+    /* ePragTyp:  */ PragTyp_THREADS,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
+  { /* zName:     */ "user_version",
+    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ BTREE_USER_VERSION },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+#if defined(SQLITE_DEBUG)
+  { /* zName:     */ "vdbe_addoptrace",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_VdbeAddopTrace },
+  { /* zName:     */ "vdbe_debug",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },
+  { /* zName:     */ "vdbe_eqp",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_VdbeEQP },
+  { /* zName:     */ "vdbe_listing",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_VdbeListing },
+  { /* zName:     */ "vdbe_trace",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_VdbeTrace },
+#endif
+#endif
+#if !defined(SQLITE_OMIT_WAL)
+  { /* zName:     */ "wal_autocheckpoint",
+    /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ 0 },
+  { /* zName:     */ "wal_checkpoint",
+    /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
+  { /* zName:     */ "writable_schema",
+    /* ePragTyp:  */ PragTyp_FLAG,
+    /* ePragFlag: */ 0,
+    /* iArg:      */ SQLITE_WriteSchema|SQLITE_RecoveryMode },
+#endif
+};
+/* Number of pragmas: 60 on by default, 73 total. */
+
+/************** End of pragma.h **********************************************/
+/************** Continuing where we left off in pragma.c *********************/
 
 /*
 ** Interpret the given string as a safety level.  Return 0 for OFF,
-** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
-** unrecognized string argument.
+** 1 for ON or NORMAL, 2 for FULL, and 3 for EXTRA.  Return 1 for an empty or 
+** unrecognized string argument.  The FULL and EXTRA option is disallowed
+** if the omitFull parameter it 1.
 **
 ** Note that the values returned are one less that the values that
 ** should be passed into sqlite3BtreeSetSafetyLevel().  The is done
 ** to support legacy SQL code.  The safety level used to be boolean
 ** and older scripts may have used numbers 0 for OFF and 1 for ON.
 */
-static u8 getSafetyLevel(const char *z){
-                             /* 123456789 123456789 */
-  static const char zText[] = "onoffalseyestruefull";
-  static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 16};
-  static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 4};
-  static const u8 iValue[] =  {1, 0, 0, 0, 1, 1, 2};
+static u8 getSafetyLevel(const char *z, int omitFull, u8 dflt){
+                             /* 123456789 123456789 123 */
+  static const char zText[] = "onoffalseyestruextrafull";
+  static const u8 iOffset[] = {0, 1, 2,  4,    9,  12,  15,   20};
+  static const u8 iLength[] = {2, 2, 3,  5,    3,   4,   5,    4};
+  static const u8 iValue[] =  {1, 0, 0,  0,    1,   1,   3,    2};
+                            /* on no off false yes true extra full */
   int i, n;
   if( sqlite3Isdigit(*z) ){
     return (u8)sqlite3Atoi(z);
   }
   n = sqlite3Strlen30(z);
   for(i=0; i<ArraySize(iLength); i++){
-    if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0 ){
+    if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0
+     && (!omitFull || iValue[i]<=1)
+    ){
       return iValue[i];
     }
   }
-  return 1;
+  return dflt;
 }
 
 /*
 ** Interpret the given string as a boolean value.
 */
-SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z){
-  return getSafetyLevel(z)&1;
+SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z, u8 dflt){
+  return getSafetyLevel(z,1,dflt)!=0;
 }
 
 /* The sqlite3GetBoolean() function is used by other modules but the
@@ -90422,7 +110774,7 @@ static int invalidateTempStorage(Parse *pParse){
     }
     sqlite3BtreeClose(db->aDb[1].pBt);
     db->aDb[1].pBt = 0;
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
   }
   return SQLITE_OK;
 }
@@ -90447,105 +110799,76 @@ static int changeTempStorage(Parse *pParse, const char *zStorageType){
 #endif /* SQLITE_PAGER_PRAGMAS */
 
 /*
-** Generate code to return a single integer value.
+** Set the names of the first N columns to the values in azCol[]
 */
-static void returnSingleInt(Parse *pParse, const char *zLabel, i64 value){
-  Vdbe *v = sqlite3GetVdbe(pParse);
-  int mem = ++pParse->nMem;
-  i64 *pI64 = sqlite3DbMallocRaw(pParse->db, sizeof(value));
-  if( pI64 ){
-    memcpy(pI64, &value, sizeof(value));
+static void setAllColumnNames(
+  Vdbe *v,               /* The query under construction */
+  int N,                 /* Number of columns */
+  const char **azCol     /* Names of columns */
+){
+  int i;
+  sqlite3VdbeSetNumCols(v, N);
+  for(i=0; i<N; i++){
+    sqlite3VdbeSetColName(v, i, COLNAME_NAME, azCol[i], SQLITE_STATIC);
   }
-  sqlite3VdbeAddOp4(v, OP_Int64, 0, mem, 0, (char*)pI64, P4_INT64);
-  sqlite3VdbeSetNumCols(v, 1);
-  sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, SQLITE_STATIC);
-  sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
+}
+static void setOneColumnName(Vdbe *v, const char *z){
+  setAllColumnNames(v, 1, &z);
 }
 
-#ifndef SQLITE_OMIT_FLAG_PRAGMAS
 /*
-** Check to see if zRight and zLeft refer to a pragma that queries
-** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
-** Also, implement the pragma.
-*/
-static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
-  static const struct sPragmaType {
-    const char *zName;  /* Name of the pragma */
-    int mask;           /* Mask for the db->flags value */
-  } aPragma[] = {
-    { "full_column_names",        SQLITE_FullColNames  },
-    { "short_column_names",       SQLITE_ShortColNames },
-    { "count_changes",            SQLITE_CountRows     },
-    { "empty_result_callbacks",   SQLITE_NullCallback  },
-    { "legacy_file_format",       SQLITE_LegacyFileFmt },
-    { "fullfsync",                SQLITE_FullFSync     },
-    { "checkpoint_fullfsync",     SQLITE_CkptFullFSync },
-    { "reverse_unordered_selects", SQLITE_ReverseOrder  },
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-    { "automatic_index",          SQLITE_AutoIndex     },
-#endif
-#ifdef SQLITE_DEBUG
-    { "sql_trace",                SQLITE_SqlTrace      },
-    { "vdbe_listing",             SQLITE_VdbeListing   },
-    { "vdbe_trace",               SQLITE_VdbeTrace     },
-#endif
-#ifndef SQLITE_OMIT_CHECK
-    { "ignore_check_constraints", SQLITE_IgnoreChecks  },
-#endif
-    /* The following is VERY experimental */
-    { "writable_schema",          SQLITE_WriteSchema|SQLITE_RecoveryMode },
-    { "omit_readlock",            SQLITE_NoReadlock    },
-
-    /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
-    ** flag if there are any active statements. */
-    { "read_uncommitted",         SQLITE_ReadUncommitted },
-    { "recursive_triggers",       SQLITE_RecTriggers },
+** Generate code to return a single integer value.
+*/
+static void returnSingleInt(Vdbe *v, const char *zLabel, i64 value){
+  sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, 1, 0, (const u8*)&value, P4_INT64);
+  setOneColumnName(v, zLabel);
+  sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+}
 
-    /* This flag may only be set if both foreign-key and trigger support
-    ** are present in the build.  */
-#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-    { "foreign_keys",             SQLITE_ForeignKeys },
-#endif
-  };
-  int i;
-  const struct sPragmaType *p;
-  for(i=0, p=aPragma; i<ArraySize(aPragma); i++, p++){
-    if( sqlite3StrICmp(zLeft, p->zName)==0 ){
-      sqlite3 *db = pParse->db;
-      Vdbe *v;
-      v = sqlite3GetVdbe(pParse);
-      assert( v!=0 );  /* Already allocated by sqlite3Pragma() */
-      if( ALWAYS(v) ){
-        if( zRight==0 ){
-          returnSingleInt(pParse, p->zName, (db->flags & p->mask)!=0 );
-        }else{
-          int mask = p->mask;          /* Mask of bits to set or clear. */
-          if( db->autoCommit==0 ){
-            /* Foreign key support may not be enabled or disabled while not
-            ** in auto-commit mode.  */
-            mask &= ~(SQLITE_ForeignKeys);
-          }
+/*
+** Generate code to return a single text value.
+*/
+static void returnSingleText(
+  Vdbe *v,                /* Prepared statement under construction */
+  const char *zLabel,     /* Name of the result column */
+  const char *zValue      /* Value to be returned */
+){
+  if( zValue ){
+    sqlite3VdbeLoadString(v, 1, (const char*)zValue);
+    setOneColumnName(v, zLabel);
+    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+  }
+}
 
-          if( sqlite3GetBoolean(zRight) ){
-            db->flags |= mask;
-          }else{
-            db->flags &= ~mask;
-          }
 
-          /* Many of the flag-pragmas modify the code generated by the SQL 
-          ** compiler (eg. count_changes). So add an opcode to expire all
-          ** compiled SQL statements after modifying a pragma value.
-          */
-          sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
-        }
+/*
+** Set the safety_level and pager flags for pager iDb.  Or if iDb<0
+** set these values for all pagers.
+*/
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+static void setAllPagerFlags(sqlite3 *db){
+  if( db->autoCommit ){
+    Db *pDb = db->aDb;
+    int n = db->nDb;
+    assert( SQLITE_FullFSync==PAGER_FULLFSYNC );
+    assert( SQLITE_CkptFullFSync==PAGER_CKPT_FULLFSYNC );
+    assert( SQLITE_CacheSpill==PAGER_CACHESPILL );
+    assert( (PAGER_FULLFSYNC | PAGER_CKPT_FULLFSYNC | PAGER_CACHESPILL)
+             ==  PAGER_FLAGS_MASK );
+    assert( (pDb->safety_level & PAGER_SYNCHRONOUS_MASK)==pDb->safety_level );
+    while( (n--) > 0 ){
+      if( pDb->pBt ){
+        sqlite3BtreeSetPagerFlags(pDb->pBt,
+                 pDb->safety_level | (db->flags & PAGER_FLAGS_MASK) );
       }
-
-      return 1;
+      pDb++;
     }
   }
-  return 0;
 }
-#endif /* SQLITE_OMIT_FLAG_PRAGMAS */
+#else
+# define setAllPagerFlags(X)  /* no-op */
+#endif
+
 
 /*
 ** Return a human-readable name for a constraint resolution action.
@@ -90595,7 +110918,7 @@ SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){
 **
 ** Pragmas are of this form:
 **
-**      PRAGMA [database.]id [= value]
+**      PRAGMA [schema.]id [= value]
 **
 ** The identifier might also be a string.  The value is a string, and
 ** identifier, or a number.  If minusFlag is true, then the value is
@@ -90607,8 +110930,8 @@ SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){
 */
 SQLITE_PRIVATE void sqlite3Pragma(
   Parse *pParse, 
-  Token *pId1,        /* First part of [database.]id field */
-  Token *pId2,        /* Second part of [database.]id field, or NULL */
+  Token *pId1,        /* First part of [schema.]id field */
+  Token *pId2,        /* Second part of [schema.]id field, or NULL */
   Token *pValue,      /* Token for <value>, or NULL */
   int minusFlag       /* True if a '-' sign preceded <value> */
 ){
@@ -90616,15 +110939,20 @@ SQLITE_PRIVATE void sqlite3Pragma(
   char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
   const char *zDb = 0;   /* The database name */
   Token *pId;            /* Pointer to <id> token */
+  char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
   int iDb;               /* Database index for <database> */
-  sqlite3 *db = pParse->db;
-  Db *pDb;
-  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);
+  int lwr, upr, mid = 0;       /* Binary search bounds */
+  int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
+  sqlite3 *db = pParse->db;    /* The database connection */
+  Db *pDb;                     /* The specific database being pragmaed */
+  Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */
+  const struct sPragmaNames *pPragma;
+
   if( v==0 ) return;
   sqlite3VdbeRunOnlyOnce(v);
   pParse->nMem = 2;
 
-  /* Interpret the [database.] part of the pragma statement. iDb is the
+  /* Interpret the [schema.] part of the pragma statement. iDb is the
   ** index of the database this pragma is being applied to in db.aDb[]. */
   iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
   if( iDb<0 ) return;
@@ -90650,11 +110978,71 @@ SQLITE_PRIVATE void sqlite3Pragma(
   if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
     goto pragma_out;
   }
- 
-#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+
+  /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
+  ** connection.  If it returns SQLITE_OK, then assume that the VFS
+  ** handled the pragma and generate a no-op prepared statement.
+  **
+  ** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,
+  ** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
+  ** object corresponding to the database file to which the pragma
+  ** statement refers.
+  **
+  ** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
+  ** file control is an array of pointers to strings (char**) in which the
+  ** second element of the array is the name of the pragma and the third
+  ** element is the argument to the pragma or NULL if the pragma has no
+  ** argument.
+  */
+  aFcntl[0] = 0;
+  aFcntl[1] = zLeft;
+  aFcntl[2] = zRight;
+  aFcntl[3] = 0;
+  db->busyHandler.nBusy = 0;
+  rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);
+  if( rc==SQLITE_OK ){
+    returnSingleText(v, "result", aFcntl[0]);
+    sqlite3_free(aFcntl[0]);
+    goto pragma_out;
+  }
+  if( rc!=SQLITE_NOTFOUND ){
+    if( aFcntl[0] ){
+      sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);
+      sqlite3_free(aFcntl[0]);
+    }
+    pParse->nErr++;
+    pParse->rc = rc;
+    goto pragma_out;
+  }
+
+  /* Locate the pragma in the lookup table */
+  lwr = 0;
+  upr = ArraySize(aPragmaNames)-1;
+  while( lwr<=upr ){
+    mid = (lwr+upr)/2;
+    rc = sqlite3_stricmp(zLeft, aPragmaNames[mid].zName);
+    if( rc==0 ) break;
+    if( rc<0 ){
+      upr = mid - 1;
+    }else{
+      lwr = mid + 1;
+    }
+  }
+  if( lwr>upr ) goto pragma_out;
+  pPragma = &aPragmaNames[mid];
+
+  /* Make sure the database schema is loaded if the pragma requires that */
+  if( (pPragma->mPragFlag & PragFlag_NeedSchema)!=0 ){
+    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+  }
+
+  /* Jump to the appropriate pragma handler */
+  switch( pPragma->ePragTyp ){
+  
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
   /*
-  **  PRAGMA [database.]default_cache_size
-  **  PRAGMA [database.]default_cache_size=N
+  **  PRAGMA [schema.]default_cache_size
+  **  PRAGMA [schema.]default_cache_size=N
   **
   ** The first form reports the current persistent setting for the
   ** page cache size.  The value returned is the maximum number of
@@ -90668,79 +111056,84 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** size.  But continue to take the absolute value of the default cache
   ** size of historical compatibility.
   */
-  if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){
+  case PragTyp_DEFAULT_CACHE_SIZE: {
+    static const int iLn = VDBE_OFFSET_LINENO(2);
     static const VdbeOpList getCacheSize[] = {
       { OP_Transaction, 0, 0,        0},                         /* 0 */
       { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */
-      { OP_IfPos,       1, 7,        0},
+      { OP_IfPos,       1, 8,        0},
       { OP_Integer,     0, 2,        0},
       { OP_Subtract,    1, 2,        1},
-      { OP_IfPos,       1, 7,        0},
+      { OP_IfPos,       1, 8,        0},
       { OP_Integer,     0, 1,        0},                         /* 6 */
+      { OP_Noop,        0, 0,        0},
       { OP_ResultRow,   1, 1,        0},
     };
-    int addr;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    VdbeOp *aOp;
     sqlite3VdbeUsesBtree(v, iDb);
     if( !zRight ){
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", SQLITE_STATIC);
+      setOneColumnName(v, "cache_size");
       pParse->nMem += 2;
-      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, iDb);
-      sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE);
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(getCacheSize));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;
     }else{
       int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
       sqlite3BeginWriteOperation(pParse, 0, iDb);
-      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
-      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
+      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);
       assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
       pDb->pSchema->cache_size = size;
       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
     }
-  }else
+    break;
+  }
+#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */
 
+#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
   /*
-  **  PRAGMA [database.]page_size
-  **  PRAGMA [database.]page_size=N
+  **  PRAGMA [schema.]page_size
+  **  PRAGMA [schema.]page_size=N
   **
   ** The first form reports the current setting for the
   ** database page size in bytes.  The second form sets the
   ** database page size value.  The value can only be set if
   ** the database has not yet been created.
   */
-  if( sqlite3StrICmp(zLeft,"page_size")==0 ){
+  case PragTyp_PAGE_SIZE: {
     Btree *pBt = pDb->pBt;
     assert( pBt!=0 );
     if( !zRight ){
       int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
-      returnSingleInt(pParse, "page_size", size);
+      returnSingleInt(v, "page_size", size);
     }else{
       /* Malloc may fail when setting the page-size, as there is an internal
       ** buffer that the pager module resizes using sqlite3_realloc().
       */
       db->nextPagesize = sqlite3Atoi(zRight);
-      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
-        db->mallocFailed = 1;
+      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){
+        sqlite3OomFault(db);
       }
     }
-  }else
+    break;
+  }
 
   /*
-  **  PRAGMA [database.]secure_delete
-  **  PRAGMA [database.]secure_delete=ON/OFF
+  **  PRAGMA [schema.]secure_delete
+  **  PRAGMA [schema.]secure_delete=ON/OFF
   **
   ** The first form reports the current setting for the
   ** secure_delete flag.  The second form changes the secure_delete
   ** flag setting and reports thenew value.
   */
-  if( sqlite3StrICmp(zLeft,"secure_delete")==0 ){
+  case PragTyp_SECURE_DELETE: {
     Btree *pBt = pDb->pBt;
     int b = -1;
     assert( pBt!=0 );
     if( zRight ){
-      b = sqlite3GetBoolean(zRight);
+      b = sqlite3GetBoolean(zRight, 0);
     }
     if( pId2->n==0 && b>=0 ){
       int ii;
@@ -90749,44 +111142,48 @@ SQLITE_PRIVATE void sqlite3Pragma(
       }
     }
     b = sqlite3BtreeSecureDelete(pBt, b);
-    returnSingleInt(pParse, "secure_delete", b);
-  }else
+    returnSingleInt(v, "secure_delete", b);
+    break;
+  }
 
   /*
-  **  PRAGMA [database.]max_page_count
-  **  PRAGMA [database.]max_page_count=N
+  **  PRAGMA [schema.]max_page_count
+  **  PRAGMA [schema.]max_page_count=N
   **
   ** The first form reports the current setting for the
   ** maximum number of pages in the database file.  The 
   ** second form attempts to change this setting.  Both
   ** forms return the current setting.
   **
-  **  PRAGMA [database.]page_count
+  ** The absolute value of N is used.  This is undocumented and might
+  ** change.  The only purpose is to provide an easy way to test
+  ** the sqlite3AbsInt32() function.
+  **
+  **  PRAGMA [schema.]page_count
   **
   ** Return the number of pages in the specified database.
   */
-  if( sqlite3StrICmp(zLeft,"page_count")==0
-   || sqlite3StrICmp(zLeft,"max_page_count")==0
-  ){
+  case PragTyp_PAGE_COUNT: {
     int iReg;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
     sqlite3CodeVerifySchema(pParse, iDb);
     iReg = ++pParse->nMem;
     if( sqlite3Tolower(zLeft[0])=='p' ){
       sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
     }else{
-      sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, sqlite3Atoi(zRight));
+      sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, 
+                        sqlite3AbsInt32(sqlite3Atoi(zRight)));
     }
     sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
     sqlite3VdbeSetNumCols(v, 1);
     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
-  }else
+    break;
+  }
 
   /*
-  **  PRAGMA [database.]locking_mode
-  **  PRAGMA [database.]locking_mode = (normal|exclusive)
+  **  PRAGMA [schema.]locking_mode
+  **  PRAGMA [schema.]locking_mode = (normal|exclusive)
   */
-  if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){
+  case PragTyp_LOCKING_MODE: {
     const char *zRet = "normal";
     int eMode = getLockingMode(zRight);
 
@@ -90819,36 +111216,25 @@ SQLITE_PRIVATE void sqlite3Pragma(
       eMode = sqlite3PagerLockingMode(pPager, eMode);
     }
 
-    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
+    assert( eMode==PAGER_LOCKINGMODE_NORMAL
+            || eMode==PAGER_LOCKINGMODE_EXCLUSIVE );
     if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
       zRet = "exclusive";
     }
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", SQLITE_STATIC);
-    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
-    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-  }else
+    returnSingleText(v, "locking_mode", zRet);
+    break;
+  }
 
   /*
-  **  PRAGMA [database.]journal_mode
-  **  PRAGMA [database.]journal_mode =
+  **  PRAGMA [schema.]journal_mode
+  **  PRAGMA [schema.]journal_mode =
   **                      (delete|persist|off|truncate|memory|wal|off)
   */
-  if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
+  case PragTyp_JOURNAL_MODE: {
     int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */
     int ii;           /* Loop counter */
 
-    /* Force the schema to be loaded on all databases.  This causes all
-    ** database files to be opened and the journal_modes set.  This is
-    ** necessary because subsequent processing must know if the databases
-    ** are in WAL mode. */
-    if( sqlite3ReadSchema(pParse) ){
-      goto pragma_out;
-    }
-
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);
-
+    setOneColumnName(v, "journal_mode");
     if( zRight==0 ){
       /* If there is no "=MODE" part of the pragma, do a query for the
       ** current mode */
@@ -90877,138 +111263,215 @@ SQLITE_PRIVATE void sqlite3Pragma(
       }
     }
     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-  }else
+    break;
+  }
 
   /*
-  **  PRAGMA [database.]journal_size_limit
-  **  PRAGMA [database.]journal_size_limit=N
+  **  PRAGMA [schema.]journal_size_limit
+  **  PRAGMA [schema.]journal_size_limit=N
   **
   ** Get or set the size limit on rollback journal files.
   */
-  if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){
+  case PragTyp_JOURNAL_SIZE_LIMIT: {
     Pager *pPager = sqlite3BtreePager(pDb->pBt);
     i64 iLimit = -2;
     if( zRight ){
-      sqlite3Atoi64(zRight, &iLimit, 1000000, SQLITE_UTF8);
+      sqlite3DecOrHexToI64(zRight, &iLimit);
       if( iLimit<-1 ) iLimit = -1;
     }
     iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
-    returnSingleInt(pParse, "journal_size_limit", iLimit);
-  }else
+    returnSingleInt(v, "journal_size_limit", iLimit);
+    break;
+  }
 
 #endif /* SQLITE_OMIT_PAGER_PRAGMAS */
 
   /*
-  **  PRAGMA [database.]auto_vacuum
-  **  PRAGMA [database.]auto_vacuum=N
+  **  PRAGMA [schema.]auto_vacuum
+  **  PRAGMA [schema.]auto_vacuum=N
   **
   ** Get or set the value of the database 'auto-vacuum' parameter.
   ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL
   */
 #ifndef SQLITE_OMIT_AUTOVACUUM
-  if( sqlite3StrICmp(zLeft,"auto_vacuum")==0 ){
+  case PragTyp_AUTO_VACUUM: {
     Btree *pBt = pDb->pBt;
     assert( pBt!=0 );
-    if( sqlite3ReadSchema(pParse) ){
-      goto pragma_out;
-    }
     if( !zRight ){
-      int auto_vacuum;
-      if( ALWAYS(pBt) ){
-         auto_vacuum = sqlite3BtreeGetAutoVacuum(pBt);
-      }else{
-         auto_vacuum = SQLITE_DEFAULT_AUTOVACUUM;
-      }
-      returnSingleInt(pParse, "auto_vacuum", auto_vacuum);
+      returnSingleInt(v, "auto_vacuum", sqlite3BtreeGetAutoVacuum(pBt));
     }else{
       int eAuto = getAutoVacuum(zRight);
       assert( eAuto>=0 && eAuto<=2 );
       db->nextAutovac = (u8)eAuto;
-      if( ALWAYS(eAuto>=0) ){
-        /* Call SetAutoVacuum() to set initialize the internal auto and
-        ** incr-vacuum flags. This is required in case this connection
-        ** creates the database file. It is important that it is created
-        ** as an auto-vacuum capable db.
+      /* Call SetAutoVacuum() to set initialize the internal auto and
+      ** incr-vacuum flags. This is required in case this connection
+      ** creates the database file. It is important that it is created
+      ** as an auto-vacuum capable db.
+      */
+      rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
+      if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
+        /* When setting the auto_vacuum mode to either "full" or 
+        ** "incremental", write the value of meta[6] in the database
+        ** file. Before writing to meta[6], check that meta[3] indicates
+        ** that this really is an auto-vacuum capable database.
         */
-        int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
-        if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
-          /* When setting the auto_vacuum mode to either "full" or 
-          ** "incremental", write the value of meta[6] in the database
-          ** file. Before writing to meta[6], check that meta[3] indicates
-          ** that this really is an auto-vacuum capable database.
-          */
-          static const VdbeOpList setMeta6[] = {
-            { OP_Transaction,    0,         1,                 0},    /* 0 */
-            { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
-            { OP_If,             1,         0,                 0},    /* 2 */
-            { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
-            { OP_Integer,        0,         1,                 0},    /* 4 */
-            { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
-          };
-          int iAddr;
-          iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
-          sqlite3VdbeChangeP1(v, iAddr, iDb);
-          sqlite3VdbeChangeP1(v, iAddr+1, iDb);
-          sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
-          sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
-          sqlite3VdbeChangeP1(v, iAddr+5, iDb);
-          sqlite3VdbeUsesBtree(v, iDb);
-        }
+        static const int iLn = VDBE_OFFSET_LINENO(2);
+        static const VdbeOpList setMeta6[] = {
+          { OP_Transaction,    0,         1,                 0},    /* 0 */
+          { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
+          { OP_If,             1,         0,                 0},    /* 2 */
+          { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
+          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 0},    /* 4 */
+        };
+        VdbeOp *aOp;
+        int iAddr = sqlite3VdbeCurrentAddr(v);
+        sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));
+        aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
+        if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+        aOp[0].p1 = iDb;
+        aOp[1].p1 = iDb;
+        aOp[2].p2 = iAddr+4;
+        aOp[4].p1 = iDb;
+        aOp[4].p3 = eAuto - 1;
+        sqlite3VdbeUsesBtree(v, iDb);
       }
     }
-  }else
+    break;
+  }
 #endif
 
   /*
-  **  PRAGMA [database.]incremental_vacuum(N)
+  **  PRAGMA [schema.]incremental_vacuum(N)
   **
   ** Do N steps of incremental vacuuming on a database.
   */
 #ifndef SQLITE_OMIT_AUTOVACUUM
-  if( sqlite3StrICmp(zLeft,"incremental_vacuum")==0 ){
+  case PragTyp_INCREMENTAL_VACUUM: {
     int iLimit, addr;
-    if( sqlite3ReadSchema(pParse) ){
-      goto pragma_out;
-    }
     if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
       iLimit = 0x7fffffff;
     }
     sqlite3BeginWriteOperation(pParse, 0, iDb);
     sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
-    addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
+    addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb); VdbeCoverage(v);
     sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
     sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
-    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
+    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr); VdbeCoverage(v);
     sqlite3VdbeJumpHere(v, addr);
-  }else
+    break;
+  }
 #endif
 
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
   /*
-  **  PRAGMA [database.]cache_size
-  **  PRAGMA [database.]cache_size=N
+  **  PRAGMA [schema.]cache_size
+  **  PRAGMA [schema.]cache_size=N
   **
   ** The first form reports the current local setting for the
-  ** page cache size.  The local setting can be different from
-  ** the persistent cache size value that is stored in the database
-  ** file itself.  The value returned is the maximum number of
-  ** pages in the page cache.  The second form sets the local
-  ** page cache size value.  It does not change the persistent
-  ** cache size stored on the disk so the cache size will revert
-  ** to its default value when the database is closed and reopened.
-  ** N should be a positive integer.
-  */
-  if( sqlite3StrICmp(zLeft,"cache_size")==0 ){
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+  ** page cache size. The second form sets the local
+  ** page cache size value.  If N is positive then that is the
+  ** number of pages in the cache.  If N is negative, then the
+  ** number of pages is adjusted so that the cache uses -N kibibytes
+  ** of memory.
+  */
+  case PragTyp_CACHE_SIZE: {
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     if( !zRight ){
-      returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
+      returnSingleInt(v, "cache_size", pDb->pSchema->cache_size);
     }else{
-      int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
+      int size = sqlite3Atoi(zRight);
       pDb->pSchema->cache_size = size;
       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
     }
-  }else
+    break;
+  }
+
+  /*
+  **  PRAGMA [schema.]cache_spill
+  **  PRAGMA cache_spill=BOOLEAN
+  **  PRAGMA [schema.]cache_spill=N
+  **
+  ** The first form reports the current local setting for the
+  ** page cache spill size. The second form turns cache spill on
+  ** or off.  When turnning cache spill on, the size is set to the
+  ** current cache_size.  The third form sets a spill size that
+  ** may be different form the cache size.
+  ** If N is positive then that is the
+  ** number of pages in the cache.  If N is negative, then the
+  ** number of pages is adjusted so that the cache uses -N kibibytes
+  ** of memory.
+  **
+  ** If the number of cache_spill pages is less then the number of
+  ** cache_size pages, no spilling occurs until the page count exceeds
+  ** the number of cache_size pages.
+  **
+  ** The cache_spill=BOOLEAN setting applies to all attached schemas,
+  ** not just the schema specified.
+  */
+  case PragTyp_CACHE_SPILL: {
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( !zRight ){
+      returnSingleInt(v, "cache_spill", 
+         (db->flags & SQLITE_CacheSpill)==0 ? 0 : 
+            sqlite3BtreeSetSpillSize(pDb->pBt,0));
+    }else{
+      int size = 1;
+      if( sqlite3GetInt32(zRight, &size) ){
+        sqlite3BtreeSetSpillSize(pDb->pBt, size);
+      }
+      if( sqlite3GetBoolean(zRight, size!=0) ){
+        db->flags |= SQLITE_CacheSpill;
+      }else{
+        db->flags &= ~SQLITE_CacheSpill;
+      }
+      setAllPagerFlags(db);
+    }
+    break;
+  }
+
+  /*
+  **  PRAGMA [schema.]mmap_size(N)
+  **
+  ** Used to set mapping size limit. The mapping size limit is
+  ** used to limit the aggregate size of all memory mapped regions of the
+  ** database file. If this parameter is set to zero, then memory mapping
+  ** is not used at all.  If N is negative, then the default memory map
+  ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
+  ** The parameter N is measured in bytes.
+  **
+  ** This value is advisory.  The underlying VFS is free to memory map
+  ** as little or as much as it wants.  Except, if N is set to 0 then the
+  ** upper layers will never invoke the xFetch interfaces to the VFS.
+  */
+  case PragTyp_MMAP_SIZE: {
+    sqlite3_int64 sz;
+#if SQLITE_MAX_MMAP_SIZE>0
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    if( zRight ){
+      int ii;
+      sqlite3DecOrHexToI64(zRight, &sz);
+      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
+      if( pId2->n==0 ) db->szMmap = sz;
+      for(ii=db->nDb-1; ii>=0; ii--){
+        if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
+          sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
+        }
+      }
+    }
+    sz = -1;
+    rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
+#else
+    sz = 0;
+    rc = SQLITE_OK;
+#endif
+    if( rc==SQLITE_OK ){
+      returnSingleInt(v, "mmap_size", sz);
+    }else if( rc!=SQLITE_NOTFOUND ){
+      pParse->nErr++;
+      pParse->rc = rc;
+    }
+    break;
+  }
 
   /*
   **   PRAGMA temp_store
@@ -91021,13 +111484,14 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** Note that it is possible for the library compile-time options to
   ** override this setting
   */
-  if( sqlite3StrICmp(zLeft, "temp_store")==0 ){
+  case PragTyp_TEMP_STORE: {
     if( !zRight ){
-      returnSingleInt(pParse, "temp_store", db->temp_store);
+      returnSingleInt(v, "temp_store", db->temp_store);
     }else{
       changeTempStorage(pParse, zRight);
     }
-  }else
+    break;
+  }
 
   /*
   **   PRAGMA temp_store_directory
@@ -91039,19 +111503,12 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** If temporary directory is changed, then invalidateTempStorage.
   **
   */
-  if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
+  case PragTyp_TEMP_STORE_DIRECTORY: {
     if( !zRight ){
-      if( sqlite3_temp_directory ){
-        sqlite3VdbeSetNumCols(v, 1);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
-            "temp_store_directory", SQLITE_STATIC);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-      }
+      returnSingleText(v, "temp_store_directory", sqlite3_temp_directory);
     }else{
 #ifndef SQLITE_OMIT_WSD
       if( zRight[0] ){
-        int rc;
         int res;
         rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
         if( rc!=SQLITE_OK || res==0 ){
@@ -91073,39 +111530,65 @@ SQLITE_PRIVATE void sqlite3Pragma(
       }
 #endif /* SQLITE_OMIT_WSD */
     }
-  }else
+    break;
+  }
 
-#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
-#  if defined(__APPLE__)
-#    define SQLITE_ENABLE_LOCKING_STYLE 1
-#  else
-#    define SQLITE_ENABLE_LOCKING_STYLE 0
-#  endif
+#if SQLITE_OS_WIN
+  /*
+  **   PRAGMA data_store_directory
+  **   PRAGMA data_store_directory = ""|"directory_name"
+  **
+  ** Return or set the local value of the data_store_directory flag.  Changing
+  ** the value sets a specific directory to be used for database files that
+  ** were specified with a relative pathname.  Setting to a null string reverts
+  ** to the default database directory, which for database files specified with
+  ** a relative path will probably be based on the current directory for the
+  ** process.  Database file specified with an absolute path are not impacted
+  ** by this setting, regardless of its value.
+  **
+  */
+  case PragTyp_DATA_STORE_DIRECTORY: {
+    if( !zRight ){
+      returnSingleText(v, "data_store_directory", sqlite3_data_directory);
+    }else{
+#ifndef SQLITE_OMIT_WSD
+      if( zRight[0] ){
+        int res;
+        rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
+        if( rc!=SQLITE_OK || res==0 ){
+          sqlite3ErrorMsg(pParse, "not a writable directory");
+          goto pragma_out;
+        }
+      }
+      sqlite3_free(sqlite3_data_directory);
+      if( zRight[0] ){
+        sqlite3_data_directory = sqlite3_mprintf("%s", zRight);
+      }else{
+        sqlite3_data_directory = 0;
+      }
+#endif /* SQLITE_OMIT_WSD */
+    }
+    break;
+  }
 #endif
+
 #if SQLITE_ENABLE_LOCKING_STYLE
   /*
-   **   PRAGMA [database.]lock_proxy_file
-   **   PRAGMA [database.]lock_proxy_file = ":auto:"|"lock_file_path"
-   **
-   ** Return or set the value of the lock_proxy_file flag.  Changing
-   ** the value sets a specific file to be used for database access locks.
-   **
-   */
-  if( sqlite3StrICmp(zLeft, "lock_proxy_file")==0 ){
+  **   PRAGMA [schema.]lock_proxy_file
+  **   PRAGMA [schema.]lock_proxy_file = ":auto:"|"lock_file_path"
+  **
+  ** Return or set the value of the lock_proxy_file flag.  Changing
+  ** the value sets a specific file to be used for database access locks.
+  **
+  */
+  case PragTyp_LOCK_PROXY_FILE: {
     if( !zRight ){
       Pager *pPager = sqlite3BtreePager(pDb->pBt);
       char *proxy_file_path = NULL;
       sqlite3_file *pFile = sqlite3PagerFile(pPager);
-      sqlite3OsFileControl(pFile, SQLITE_GET_LOCKPROXYFILE, 
+      sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE, 
                            &proxy_file_path);
-      
-      if( proxy_file_path ){
-        sqlite3VdbeSetNumCols(v, 1);
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
-                              "lock_proxy_file", SQLITE_STATIC);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, proxy_file_path, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
-      }
+      returnSingleText(v, "lock_proxy_file", proxy_file_path);
     }else{
       Pager *pPager = sqlite3BtreePager(pDb->pBt);
       sqlite3_file *pFile = sqlite3PagerFile(pPager);
@@ -91122,38 +111605,72 @@ SQLITE_PRIVATE void sqlite3Pragma(
         goto pragma_out;
       }
     }
-  }else
+    break;
+  }
 #endif /* SQLITE_ENABLE_LOCKING_STYLE */      
     
   /*
-  **   PRAGMA [database.]synchronous
-  **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
+  **   PRAGMA [schema.]synchronous
+  **   PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL|EXTRA
   **
   ** Return or set the local value of the synchronous flag.  Changing
   ** the local value does not make changes to the disk file and the
   ** default value will be restored the next time the database is
   ** opened.
   */
-  if( sqlite3StrICmp(zLeft,"synchronous")==0 ){
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+  case PragTyp_SYNCHRONOUS: {
     if( !zRight ){
-      returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
+      returnSingleInt(v, "synchronous", pDb->safety_level-1);
     }else{
       if( !db->autoCommit ){
         sqlite3ErrorMsg(pParse, 
             "Safety level may not be changed inside a transaction");
       }else{
-        pDb->safety_level = getSafetyLevel(zRight)+1;
+        int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;
+        if( iLevel==0 ) iLevel = 1;
+        pDb->safety_level = iLevel;
+        pDb->bSyncSet = 1;
+        setAllPagerFlags(db);
       }
     }
-  }else
+    break;
+  }
 #endif /* SQLITE_OMIT_PAGER_PRAGMAS */
 
 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
-  if( flagPragma(pParse, zLeft, zRight) ){
-    /* The flagPragma() subroutine also generates any necessary code
-    ** there is nothing more to do here */
-  }else
+  case PragTyp_FLAG: {
+    if( zRight==0 ){
+      returnSingleInt(v, pPragma->zName, (db->flags & pPragma->iArg)!=0 );
+    }else{
+      int mask = pPragma->iArg;    /* Mask of bits to set or clear. */
+      if( db->autoCommit==0 ){
+        /* Foreign key support may not be enabled or disabled while not
+        ** in auto-commit mode.  */
+        mask &= ~(SQLITE_ForeignKeys);
+      }
+#if SQLITE_USER_AUTHENTICATION
+      if( db->auth.authLevel==UAUTH_User ){
+        /* Do not allow non-admin users to modify the schema arbitrarily */
+        mask &= ~(SQLITE_WriteSchema);
+      }
+#endif
+
+      if( sqlite3GetBoolean(zRight, 0) ){
+        db->flags |= mask;
+      }else{
+        db->flags &= ~mask;
+        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
+      }
+
+      /* Many of the flag-pragmas modify the code generated by the SQL 
+      ** compiler (eg. count_changes). So add an opcode to expire all
+      ** compiled SQL statements after modifying a pragma value.
+      */
+      sqlite3VdbeAddOp0(v, OP_Expire);
+      setAllPagerFlags(db);
+    }
+    break;
+  }
 #endif /* SQLITE_OMIT_FLAG_PRAGMAS */
 
 #ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
@@ -91169,166 +111686,201 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** notnull:    True if 'NOT NULL' is part of column declaration
   ** dflt_value: The default value for the column, if any.
   */
-  if( sqlite3StrICmp(zLeft, "table_info")==0 && zRight ){
+  case PragTyp_TABLE_INFO: if( zRight ){
     Table *pTab;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
-    pTab = sqlite3FindTable(db, zRight, zDb);
+    pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
     if( pTab ){
-      int i;
+      static const char *azCol[] = {
+         "cid", "name", "type", "notnull", "dflt_value", "pk"
+      };
+      int i, k;
       int nHidden = 0;
       Column *pCol;
-      sqlite3VdbeSetNumCols(v, 6);
+      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
       pParse->nMem = 6;
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", SQLITE_STATIC);
+      sqlite3CodeVerifySchema(pParse, iDb);
+      setAllColumnNames(v, 6, azCol); assert( 6==ArraySize(azCol) );
       sqlite3ViewGetColumnNames(pParse, pTab);
       for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
         if( IsHiddenColumn(pCol) ){
           nHidden++;
           continue;
         }
-        sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-           pCol->zType ? pCol->zType : "", 0);
-        sqlite3VdbeAddOp2(v, OP_Integer, (pCol->notNull ? 1 : 0), 4);
-        if( pCol->zDflt ){
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pCol->zDflt, 0);
+        if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){
+          k = 0;
+        }else if( pPk==0 ){
+          k = 1;
         }else{
-          sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
+          for(k=1; k<=pTab->nCol && pPk->aiColumn[k-1]!=i; k++){}
         }
-        sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
+        assert( pCol->pDflt==0 || pCol->pDflt->op==TK_SPAN );
+        sqlite3VdbeMultiLoad(v, 1, "issisi",
+               i-nHidden,
+               pCol->zName,
+               sqlite3ColumnType(pCol,""),
+               pCol->notNull ? 1 : 0,
+               pCol->pDflt ? pCol->pDflt->u.zToken : 0,
+               k);
         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
       }
     }
-  }else
+  }
+  break;
+
+  case PragTyp_STATS: {
+    static const char *azCol[] = { "table", "index", "width", "height" };
+    Index *pIdx;
+    HashElem *i;
+    v = sqlite3GetVdbe(pParse);
+    pParse->nMem = 4;
+    sqlite3CodeVerifySchema(pParse, iDb);
+    setAllColumnNames(v, 4, azCol);  assert( 4==ArraySize(azCol) );
+    for(i=sqliteHashFirst(&pDb->pSchema->tblHash); i; i=sqliteHashNext(i)){
+      Table *pTab = sqliteHashData(i);
+      sqlite3VdbeMultiLoad(v, 1, "ssii",
+           pTab->zName,
+           0,
+           pTab->szTabRow,
+           pTab->nRowLogEst);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        sqlite3VdbeMultiLoad(v, 2, "sii",
+           pIdx->zName,
+           pIdx->szIdxRow,
+           pIdx->aiRowLogEst[0]);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
+      }
+    }
+  }
+  break;
 
-  if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
+  case PragTyp_INDEX_INFO: if( zRight ){
     Index *pIdx;
     Table *pTab;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
     pIdx = sqlite3FindIndex(db, zRight, zDb);
     if( pIdx ){
+      static const char *azCol[] = {
+         "seqno", "cid", "name", "desc", "coll", "key"
+      };
       int i;
+      int mx;
+      if( pPragma->iArg ){
+        /* PRAGMA index_xinfo (newer version with more rows and columns) */
+        mx = pIdx->nColumn;
+        pParse->nMem = 6;
+      }else{
+        /* PRAGMA index_info (legacy version) */
+        mx = pIdx->nKeyCol;
+        pParse->nMem = 3;
+      }
       pTab = pIdx->pTable;
-      sqlite3VdbeSetNumCols(v, 3);
-      pParse->nMem = 3;
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE_STATIC);
-      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE_STATIC);
-      for(i=0; i<pIdx->nColumn; i++){
-        int cnum = pIdx->aiColumn[i];
-        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
-        assert( pTab->nCol>cnum );
-        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
-        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
+      sqlite3CodeVerifySchema(pParse, iDb);
+      assert( pParse->nMem<=ArraySize(azCol) );
+      setAllColumnNames(v, pParse->nMem, azCol);
+      for(i=0; i<mx; i++){
+        i16 cnum = pIdx->aiColumn[i];
+        sqlite3VdbeMultiLoad(v, 1, "iis", i, cnum,
+                             cnum<0 ? 0 : pTab->aCol[cnum].zName);
+        if( pPragma->iArg ){
+          sqlite3VdbeMultiLoad(v, 4, "isi",
+            pIdx->aSortOrder[i],
+            pIdx->azColl[i],
+            i<pIdx->nKeyCol);
+        }
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, pParse->nMem);
       }
     }
-  }else
+  }
+  break;
 
-  if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
+  case PragTyp_INDEX_LIST: if( zRight ){
     Index *pIdx;
     Table *pTab;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    int i;
     pTab = sqlite3FindTable(db, zRight, zDb);
     if( pTab ){
+      static const char *azCol[] = {
+        "seq", "name", "unique", "origin", "partial"
+      };
       v = sqlite3GetVdbe(pParse);
-      pIdx = pTab->pIndex;
-      if( pIdx ){
-        int i = 0; 
-        sqlite3VdbeSetNumCols(v, 3);
-        pParse->nMem = 3;
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
-        while(pIdx){
-          sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-          sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
-          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
-          sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
-          ++i;
-          pIdx = pIdx->pNext;
-        }
+      pParse->nMem = 5;
+      sqlite3CodeVerifySchema(pParse, iDb);
+      setAllColumnNames(v, 5, azCol);  assert( 5==ArraySize(azCol) );
+      for(pIdx=pTab->pIndex, i=0; pIdx; pIdx=pIdx->pNext, i++){
+        const char *azOrigin[] = { "c", "u", "pk" };
+        sqlite3VdbeMultiLoad(v, 1, "isisi",
+           i,
+           pIdx->zName,
+           IsUniqueIndex(pIdx),
+           azOrigin[pIdx->idxType],
+           pIdx->pPartIdxWhere!=0);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
       }
     }
-  }else
+  }
+  break;
 
-  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
+  case PragTyp_DATABASE_LIST: {
+    static const char *azCol[] = { "seq", "name", "file" };
     int i;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
-    sqlite3VdbeSetNumCols(v, 3);
     pParse->nMem = 3;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE_STATIC);
+    setAllColumnNames(v, 3, azCol); assert( 3==ArraySize(azCol) );
     for(i=0; i<db->nDb; i++){
       if( db->aDb[i].pBt==0 ) continue;
       assert( db->aDb[i].zName!=0 );
-      sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
-           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
+      sqlite3VdbeMultiLoad(v, 1, "iss",
+         i,
+         db->aDb[i].zName,
+         sqlite3BtreeGetFilename(db->aDb[i].pBt));
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
     }
-  }else
+  }
+  break;
 
-  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
+  case PragTyp_COLLATION_LIST: {
+    static const char *azCol[] = { "seq", "name" };
     int i = 0;
     HashElem *p;
-    sqlite3VdbeSetNumCols(v, 2);
     pParse->nMem = 2;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
+    setAllColumnNames(v, 2, azCol); assert( 2==ArraySize(azCol) );
     for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
       CollSeq *pColl = (CollSeq *)sqliteHashData(p);
-      sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
+      sqlite3VdbeMultiLoad(v, 1, "is", i++, pColl->zName);
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
     }
-  }else
+  }
+  break;
 #endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */
 
 #ifndef SQLITE_OMIT_FOREIGN_KEY
-  if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
+  case PragTyp_FOREIGN_KEY_LIST: if( zRight ){
     FKey *pFK;
     Table *pTab;
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
     pTab = sqlite3FindTable(db, zRight, zDb);
     if( pTab ){
       v = sqlite3GetVdbe(pParse);
       pFK = pTab->pFKey;
       if( pFK ){
+        static const char *azCol[] = {
+           "id", "seq", "table", "from", "to", "on_update", "on_delete",
+           "match"
+        };
         int i = 0; 
-        sqlite3VdbeSetNumCols(v, 8);
         pParse->nMem = 8;
-        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "on_update", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 6, COLNAME_NAME, "on_delete", SQLITE_STATIC);
-        sqlite3VdbeSetColName(v, 7, COLNAME_NAME, "match", SQLITE_STATIC);
+        sqlite3CodeVerifySchema(pParse, iDb);
+        setAllColumnNames(v, 8, azCol); assert( 8==ArraySize(azCol) );
         while(pFK){
           int j;
           for(j=0; j<pFK->nCol; j++){
-            char *zCol = pFK->aCol[j].zCol;
-            char *zOnDelete = (char *)actionName(pFK->aAction[0]);
-            char *zOnUpdate = (char *)actionName(pFK->aAction[1]);
-            sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
-            sqlite3VdbeAddOp2(v, OP_Integer, j, 2);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
-                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
-            sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 6, 0, zOnUpdate, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 7, 0, zOnDelete, 0);
-            sqlite3VdbeAddOp4(v, OP_String8, 0, 8, 0, "NONE", 0);
+            sqlite3VdbeMultiLoad(v, 1, "iissssss",
+                   i,
+                   j,
+                   pFK->zTo,
+                   pTab->aCol[pFK->aCol[j].iFrom].zName,
+                   pFK->aCol[j].zCol,
+                   actionName(pFK->aAction[1]),  /* ON UPDATE */
+                   actionName(pFK->aAction[0]),  /* ON DELETE */
+                   "NONE");
             sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 8);
           }
           ++i;
@@ -91336,62 +111888,174 @@ SQLITE_PRIVATE void sqlite3Pragma(
         }
       }
     }
-  }else
+  }
+  break;
+#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
+
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+#ifndef SQLITE_OMIT_TRIGGER
+  case PragTyp_FOREIGN_KEY_CHECK: {
+    FKey *pFK;             /* A foreign key constraint */
+    Table *pTab;           /* Child table contain "REFERENCES" keyword */
+    Table *pParent;        /* Parent table that child points to */
+    Index *pIdx;           /* Index in the parent table */
+    int i;                 /* Loop counter:  Foreign key number for pTab */
+    int j;                 /* Loop counter:  Field of the foreign key */
+    HashElem *k;           /* Loop counter:  Next table in schema */
+    int x;                 /* result variable */
+    int regResult;         /* 3 registers to hold a result row */
+    int regKey;            /* Register to hold key for checking the FK */
+    int regRow;            /* Registers to hold a row from pTab */
+    int addrTop;           /* Top of a loop checking foreign keys */
+    int addrOk;            /* Jump here if the key is OK */
+    int *aiCols;           /* child to parent column mapping */
+    static const char *azCol[] = { "table", "rowid", "parent", "fkid" };
+
+    regResult = pParse->nMem+1;
+    pParse->nMem += 4;
+    regKey = ++pParse->nMem;
+    regRow = ++pParse->nMem;
+    v = sqlite3GetVdbe(pParse);
+    setAllColumnNames(v, 4, azCol); assert( 4==ArraySize(azCol) );
+    sqlite3CodeVerifySchema(pParse, iDb);
+    k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);
+    while( k ){
+      if( zRight ){
+        pTab = sqlite3LocateTable(pParse, 0, zRight, zDb);
+        k = 0;
+      }else{
+        pTab = (Table*)sqliteHashData(k);
+        k = sqliteHashNext(k);
+      }
+      if( pTab==0 || pTab->pFKey==0 ) continue;
+      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+      if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;
+      sqlite3OpenTable(pParse, 0, iDb, pTab, OP_OpenRead);
+      sqlite3VdbeLoadString(v, regResult, pTab->zName);
+      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
+        pParent = sqlite3FindTable(db, pFK->zTo, zDb);
+        if( pParent==0 ) continue;
+        pIdx = 0;
+        sqlite3TableLock(pParse, iDb, pParent->tnum, 0, pParent->zName);
+        x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, 0);
+        if( x==0 ){
+          if( pIdx==0 ){
+            sqlite3OpenTable(pParse, i, iDb, pParent, OP_OpenRead);
+          }else{
+            sqlite3VdbeAddOp3(v, OP_OpenRead, i, pIdx->tnum, iDb);
+            sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+          }
+        }else{
+          k = 0;
+          break;
+        }
+      }
+      assert( pParse->nErr>0 || pFK==0 );
+      if( pFK ) break;
+      if( pParse->nTab<i ) pParse->nTab = i;
+      addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0); VdbeCoverage(v);
+      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
+        pParent = sqlite3FindTable(db, pFK->zTo, zDb);
+        pIdx = 0;
+        aiCols = 0;
+        if( pParent ){
+          x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
+          assert( x==0 );
+        }
+        addrOk = sqlite3VdbeMakeLabel(v);
+        if( pParent && pIdx==0 ){
+          int iKey = pFK->aCol[0].iFrom;
+          assert( iKey>=0 && iKey<pTab->nCol );
+          if( iKey!=pTab->iPKey ){
+            sqlite3VdbeAddOp3(v, OP_Column, 0, iKey, regRow);
+            sqlite3ColumnDefault(v, pTab, iKey, regRow);
+            sqlite3VdbeAddOp2(v, OP_IsNull, regRow, addrOk); VdbeCoverage(v);
+          }else{
+            sqlite3VdbeAddOp2(v, OP_Rowid, 0, regRow);
+          }
+          sqlite3VdbeAddOp3(v, OP_SeekRowid, i, 0, regRow); VdbeCoverage(v);
+          sqlite3VdbeGoto(v, addrOk);
+          sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
+        }else{
+          for(j=0; j<pFK->nCol; j++){
+            sqlite3ExprCodeGetColumnOfTable(v, pTab, 0,
+                            aiCols ? aiCols[j] : pFK->aCol[j].iFrom, regRow+j);
+            sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
+          }
+          if( pParent ){
+            sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,
+                              sqlite3IndexAffinityStr(db,pIdx), pFK->nCol);
+            sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
+            VdbeCoverage(v);
+          }
+        }
+        sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
+        sqlite3VdbeMultiLoad(v, regResult+2, "si", pFK->zTo, i-1);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
+        sqlite3VdbeResolveLabel(v, addrOk);
+        sqlite3DbFree(db, aiCols);
+      }
+      sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1); VdbeCoverage(v);
+      sqlite3VdbeJumpHere(v, addrTop);
+    }
+  }
+  break;
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
 #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
 
 #ifndef NDEBUG
-  if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
+  case PragTyp_PARSER_TRACE: {
     if( zRight ){
-      if( sqlite3GetBoolean(zRight) ){
-        sqlite3ParserTrace(stderr, "parser: ");
+      if( sqlite3GetBoolean(zRight, 0) ){
+        sqlite3ParserTrace(stdout, "parser: ");
       }else{
         sqlite3ParserTrace(0, 0);
       }
     }
-  }else
+  }
+  break;
 #endif
 
   /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
   ** used will be case sensitive or not depending on the RHS.
   */
-  if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){
+  case PragTyp_CASE_SENSITIVE_LIKE: {
     if( zRight ){
-      sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight));
+      sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight, 0));
     }
-  }else
+  }
+  break;
 
 #ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
 # define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
 #endif
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
-  /* Pragma "quick_check" is an experimental reduced version of 
+  /* Pragma "quick_check" is reduced version of 
   ** integrity_check designed to detect most database corruption
   ** without most of the overhead of a full integrity-check.
   */
-  if( sqlite3StrICmp(zLeft, "integrity_check")==0
-   || sqlite3StrICmp(zLeft, "quick_check")==0 
-  ){
+  case PragTyp_INTEGRITY_CHECK: {
     int i, j, addr, mxErr;
 
-    /* Code that appears at the end of the integrity check.  If no error
-    ** messages have been generated, output OK.  Otherwise output the
-    ** error message
-    */
-    static const VdbeOpList endCode[] = {
-      { OP_AddImm,      1, 0,        0},    /* 0 */
-      { OP_IfNeg,       1, 0,        0},    /* 1 */
-      { OP_String8,     0, 3,        0},    /* 2 */
-      { OP_ResultRow,   3, 1,        0},
-    };
-
     int isQuick = (sqlite3Tolower(zLeft[0])=='q');
 
+    /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
+    ** then iDb is set to the index of the database identified by <db>.
+    ** In this case, the integrity of database iDb only is verified by
+    ** the VDBE created below.
+    **
+    ** Otherwise, if the command was simply "PRAGMA integrity_check" (or
+    ** "PRAGMA quick_check"), then iDb is set to 0. In this case, set iDb
+    ** to -1 here, to indicate that the VDBE should verify the integrity
+    ** of all attached databases.  */
+    assert( iDb>=0 );
+    assert( iDb==0 || pId2->z );
+    if( pId2->z==0 ) iDb = -1;
+
     /* Initialize the VDBE program */
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
     pParse->nMem = 6;
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", SQLITE_STATIC);
+    setOneColumnName(v, "integrity_check");
 
     /* Set the maximum error count */
     mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
@@ -91407,42 +112071,53 @@ SQLITE_PRIVATE void sqlite3Pragma(
     for(i=0; i<db->nDb; i++){
       HashElem *x;
       Hash *pTbls;
+      int *aRoot;
       int cnt = 0;
+      int mxIdx = 0;
+      int nIdx;
 
       if( OMIT_TEMPDB && i==1 ) continue;
+      if( iDb>=0 && i!=iDb ) continue;
 
       sqlite3CodeVerifySchema(pParse, i);
       addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
+      VdbeCoverage(v);
       sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
       sqlite3VdbeJumpHere(v, addr);
 
       /* Do an integrity check of the B-Tree
       **
-      ** Begin by filling registers 2, 3, ... with the root pages numbers
+      ** Begin by finding the root pages numbers
       ** for all tables and indices in the database.
       */
-      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+      assert( sqlite3SchemaMutexHeld(db, i, 0) );
       pTbls = &db->aDb[i].pSchema->tblHash;
-      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
+      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
+        Table *pTab = sqliteHashData(x);
+        Index *pIdx;
+        if( HasRowid(pTab) ) cnt++;
+        for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ cnt++; }
+        if( nIdx>mxIdx ) mxIdx = nIdx;
+      }
+      aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));
+      if( aRoot==0 ) break;
+      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
         Table *pTab = sqliteHashData(x);
         Index *pIdx;
-        sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
-        cnt++;
+        if( HasRowid(pTab) ) aRoot[cnt++] = pTab->tnum;
         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
-          cnt++;
+          aRoot[cnt++] = pIdx->tnum;
         }
       }
+      aRoot[cnt] = 0;
 
       /* Make sure sufficient number of registers have been allocated */
-      if( pParse->nMem < cnt+4 ){
-        pParse->nMem = cnt+4;
-      }
+      pParse->nMem = MAX( pParse->nMem, 8+mxIdx );
 
       /* Do the b-tree integrity checks */
-      sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
+      sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
       sqlite3VdbeChangeP5(v, (u8)i);
-      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2);
+      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
       sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
          sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
          P4_DYNAMIC);
@@ -91455,77 +112130,137 @@ SQLITE_PRIVATE void sqlite3Pragma(
       */
       for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
         Table *pTab = sqliteHashData(x);
-        Index *pIdx;
+        Index *pIdx, *pPk;
+        Index *pPrior = 0;
         int loopTop;
+        int iDataCur, iIdxCur;
+        int r1 = -1;
 
         if( pTab->pIndex==0 ) continue;
+        pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
         addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);  /* Stop if out of errors */
+        VdbeCoverage(v);
         sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
         sqlite3VdbeJumpHere(v, addr);
-        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
-        sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);  /* reg(2) will count entries */
-        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
-        sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);   /* increment entry count */
+        sqlite3ExprCacheClear(pParse);
+        sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead, 0,
+                                   1, 0, &iDataCur, &iIdxCur);
+        sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);
         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-          int jmp2;
-          int r1;
-          static const VdbeOpList idxErr[] = {
-            { OP_AddImm,      1, -1,  0},
-            { OP_String8,     0,  3,  0},    /* 1 */
-            { OP_Rowid,       1,  4,  0},
-            { OP_String8,     0,  5,  0},    /* 3 */
-            { OP_String8,     0,  6,  0},    /* 4 */
-            { OP_Concat,      4,  3,  3},
-            { OP_Concat,      5,  3,  3},
-            { OP_Concat,      6,  3,  3},
-            { OP_ResultRow,   3,  1,  0},
-            { OP_IfPos,       1,  0,  0},    /* 9 */
-            { OP_Halt,        0,  0,  0},
-          };
-          r1 = sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 0);
-          jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, j+2, 0, r1, pIdx->nColumn+1);
-          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
-          sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
-          sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC);
-          sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_TRANSIENT);
-          sqlite3VdbeJumpHere(v, addr+9);
+          sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */
+        }
+        assert( pParse->nMem>=8+j );
+        assert( sqlite3NoTempsInRange(pParse,1,7+j) );
+        sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);
+        loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);
+        /* Verify that all NOT NULL columns really are NOT NULL */
+        for(j=0; j<pTab->nCol; j++){
+          char *zErr;
+          int jmp2, jmp3;
+          if( j==pTab->iPKey ) continue;
+          if( pTab->aCol[j].notNull==0 ) continue;
+          sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);
+          sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
+          jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);
+          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
+          zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
+                              pTab->aCol[j].zName);
+          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
+          jmp3 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
+          sqlite3VdbeAddOp0(v, OP_Halt);
           sqlite3VdbeJumpHere(v, jmp2);
+          sqlite3VdbeJumpHere(v, jmp3);
         }
-        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
-        sqlite3VdbeJumpHere(v, loopTop);
+        /* Validate index entries for the current row */
         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-          static const VdbeOpList cntIdx[] = {
-             { OP_Integer,      0,  3,  0},
-             { OP_Rewind,       0,  0,  0},  /* 1 */
-             { OP_AddImm,       3,  1,  0},
-             { OP_Next,         0,  0,  0},  /* 3 */
-             { OP_Eq,           2,  0,  3},  /* 4 */
-             { OP_AddImm,       1, -1,  0},
-             { OP_String8,      0,  2,  0},  /* 6 */
-             { OP_String8,      0,  3,  0},  /* 7 */
-             { OP_Concat,       3,  2,  2},
-             { OP_ResultRow,    2,  1,  0},
-          };
-          addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
+          int jmp2, jmp3, jmp4, jmp5;
+          int ckUniq = sqlite3VdbeMakeLabel(v);
+          if( pPk==pIdx ) continue;
+          r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 0, &jmp3,
+                                       pPrior, r1);
+          pPrior = pIdx;
+          sqlite3VdbeAddOp2(v, OP_AddImm, 8+j, 1);  /* increment entry count */
+          /* Verify that an index entry exists for the current table row */
+          jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,
+                                      pIdx->nColumn); VdbeCoverage(v);
+          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
+          sqlite3VdbeLoadString(v, 3, "row ");
+          sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
+          sqlite3VdbeLoadString(v, 4, " missing from index ");
+          sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
+          jmp5 = sqlite3VdbeLoadString(v, 4, pIdx->zName);
+          sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
+          jmp4 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
+          sqlite3VdbeAddOp0(v, OP_Halt);
+          sqlite3VdbeJumpHere(v, jmp2);
+          /* For UNIQUE indexes, verify that only one entry exists with the
+          ** current key.  The entry is unique if (1) any column is NULL
+          ** or (2) the next entry has a different key */
+          if( IsUniqueIndex(pIdx) ){
+            int uniqOk = sqlite3VdbeMakeLabel(v);
+            int jmp6;
+            int kk;
+            for(kk=0; kk<pIdx->nKeyCol; kk++){
+              int iCol = pIdx->aiColumn[kk];
+              assert( iCol!=XN_ROWID && iCol<pTab->nCol );
+              if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
+              sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
+              VdbeCoverage(v);
+            }
+            jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
+            sqlite3VdbeGoto(v, uniqOk);
+            sqlite3VdbeJumpHere(v, jmp6);
+            sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,
+                                 pIdx->nKeyCol); VdbeCoverage(v);
+            sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
+            sqlite3VdbeLoadString(v, 3, "non-unique entry in index ");
+            sqlite3VdbeGoto(v, jmp5);
+            sqlite3VdbeResolveLabel(v, uniqOk);
+          }
+          sqlite3VdbeJumpHere(v, jmp4);
+          sqlite3ResolvePartIdxLabel(pParse, jmp3);
+        }
+        sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
+        sqlite3VdbeJumpHere(v, loopTop-1);
+#ifndef SQLITE_OMIT_BTREECOUNT
+        sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");
+        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+          if( pPk==pIdx ) continue;
+          addr = sqlite3VdbeCurrentAddr(v);
+          sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr+2); VdbeCoverage(v);
           sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
-          sqlite3VdbeJumpHere(v, addr);
-          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
-          sqlite3VdbeChangeP1(v, addr+1, j+2);
-          sqlite3VdbeChangeP2(v, addr+1, addr+4);
-          sqlite3VdbeChangeP1(v, addr+3, j+2);
-          sqlite3VdbeChangeP2(v, addr+3, addr+2);
-          sqlite3VdbeJumpHere(v, addr+4);
-          sqlite3VdbeChangeP4(v, addr+6, 
-                     "wrong # of entries in index ", P4_STATIC);
-          sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_TRANSIENT);
+          sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
+          sqlite3VdbeAddOp3(v, OP_Eq, 8+j, addr+8, 3); VdbeCoverage(v);
+          sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
+          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
+          sqlite3VdbeLoadString(v, 3, pIdx->zName);
+          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
         }
+#endif /* SQLITE_OMIT_BTREECOUNT */
       } 
     }
-    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
-    sqlite3VdbeChangeP2(v, addr, -mxErr);
-    sqlite3VdbeJumpHere(v, addr+1);
-    sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
-  }else
+    {
+      static const int iLn = VDBE_OFFSET_LINENO(2);
+      static const VdbeOpList endCode[] = {
+        { OP_AddImm,      1, 0,        0},    /* 0 */
+        { OP_If,          1, 4,        0},    /* 1 */
+        { OP_String8,     0, 3,        0},    /* 2 */
+        { OP_ResultRow,   3, 1,        0},    /* 3 */
+      };
+      VdbeOp *aOp;
+
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
+      if( aOp ){
+        aOp[0].p2 = -mxErr;
+        aOp[2].p4type = P4_STATIC;
+        aOp[2].p4.z = "ok";
+      }
+    }
+  }
+  break;
 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
 
 #ifndef SQLITE_OMIT_UTF16
@@ -91551,7 +112286,7 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** new database files created using this database handle. It is only
   ** useful if invoked immediately after the main database i
   */
-  if( sqlite3StrICmp(zLeft, "encoding")==0 ){
+  case PragTyp_ENCODING: {
     static const struct EncName {
       char *zName;
       u8 enc;
@@ -91569,14 +112304,10 @@ SQLITE_PRIVATE void sqlite3Pragma(
     const struct EncName *pEnc;
     if( !zRight ){    /* "PRAGMA encoding" */
       if( sqlite3ReadSchema(pParse) ) goto pragma_out;
-      sqlite3VdbeSetNumCols(v, 1);
-      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", SQLITE_STATIC);
-      sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
       assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );
       assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );
       assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );
-      sqlite3VdbeChangeP4(v, -1, encnames[ENC(pParse->db)].zName, P4_STATIC);
-      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
+      returnSingleText(v, "encoding", encnames[ENC(pParse->db)].zName);
     }else{                        /* "PRAGMA encoding = XXX" */
       /* Only change the value of sqlite.enc if the database handle is not
       ** initialized. If the main database exists, the new sqlite.enc value
@@ -91589,7 +112320,8 @@ SQLITE_PRIVATE void sqlite3Pragma(
       ){
         for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
           if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
-            ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
+            SCHEMA_ENC(db) = ENC(db) =
+                pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
             break;
           }
         }
@@ -91598,16 +112330,24 @@ SQLITE_PRIVATE void sqlite3Pragma(
         }
       }
     }
-  }else
+  }
+  break;
 #endif /* SQLITE_OMIT_UTF16 */
 
 #ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
   /*
-  **   PRAGMA [database.]schema_version
-  **   PRAGMA [database.]schema_version = <integer>
+  **   PRAGMA [schema.]schema_version
+  **   PRAGMA [schema.]schema_version = <integer>
+  **
+  **   PRAGMA [schema.]user_version
+  **   PRAGMA [schema.]user_version = <integer>
+  **
+  **   PRAGMA [schema.]freelist_count
   **
-  **   PRAGMA [database.]user_version
-  **   PRAGMA [database.]user_version = <integer>
+  **   PRAGMA [schema.]data_version
+  **
+  **   PRAGMA [schema.]application_id
+  **   PRAGMA [schema.]application_id = <integer>
   **
   ** The pragma's schema_version and user_version are used to set or get
   ** the value of the schema-version and user-version, respectively. Both
@@ -91627,36 +112367,23 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** The user-version is not used internally by SQLite. It may be used by
   ** applications for any purpose.
   */
-  if( sqlite3StrICmp(zLeft, "schema_version")==0 
-   || sqlite3StrICmp(zLeft, "user_version")==0 
-   || sqlite3StrICmp(zLeft, "freelist_count")==0 
-  ){
-    int iCookie;   /* Cookie index. 1 for schema-cookie, 6 for user-cookie. */
+  case PragTyp_HEADER_VALUE: {
+    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
     sqlite3VdbeUsesBtree(v, iDb);
-    switch( zLeft[0] ){
-      case 'f': case 'F':
-        iCookie = BTREE_FREE_PAGE_COUNT;
-        break;
-      case 's': case 'S':
-        iCookie = BTREE_SCHEMA_VERSION;
-        break;
-      default:
-        iCookie = BTREE_USER_VERSION;
-        break;
-    }
-
-    if( zRight && iCookie!=BTREE_FREE_PAGE_COUNT ){
+    if( zRight && (pPragma->mPragFlag & PragFlag_ReadOnly)==0 ){
       /* Write the specified cookie value */
       static const VdbeOpList setCookie[] = {
         { OP_Transaction,    0,  1,  0},    /* 0 */
-        { OP_Integer,        0,  1,  0},    /* 1 */
-        { OP_SetCookie,      0,  0,  1},    /* 2 */
+        { OP_SetCookie,      0,  0,  0},    /* 1 */
       };
-      int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, sqlite3Atoi(zRight));
-      sqlite3VdbeChangeP1(v, addr+2, iDb);
-      sqlite3VdbeChangeP2(v, addr+2, iCookie);
+      VdbeOp *aOp;
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[1].p2 = iCookie;
+      aOp[1].p3 = sqlite3Atoi(zRight);
     }else{
       /* Read the specified cookie value */
       static const VdbeOpList readCookie[] = {
@@ -91664,14 +112391,19 @@ SQLITE_PRIVATE void sqlite3Pragma(
         { OP_ReadCookie,      0,  1,  0},    /* 1 */
         { OP_ResultRow,       1,  1,  0}
       };
-      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
-      sqlite3VdbeChangeP1(v, addr, iDb);
-      sqlite3VdbeChangeP1(v, addr+1, iDb);
-      sqlite3VdbeChangeP3(v, addr+1, iCookie);
+      VdbeOp *aOp;
+      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(readCookie));
+      aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0);
+      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
+      aOp[0].p1 = iDb;
+      aOp[1].p1 = iDb;
+      aOp[1].p3 = iCookie;
       sqlite3VdbeSetNumCols(v, 1);
       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
+      sqlite3VdbeReusable(v);
     }
-  }else
+  }
+  break;
 #endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
 
 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
@@ -91681,26 +112413,28 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** Return the names of all compile-time options used in this build,
   ** one option per row.
   */
-  if( sqlite3StrICmp(zLeft, "compile_options")==0 ){
+  case PragTyp_COMPILE_OPTIONS: {
     int i = 0;
     const char *zOpt;
-    sqlite3VdbeSetNumCols(v, 1);
     pParse->nMem = 1;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
+    setOneColumnName(v, "compile_option");
     while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
+      sqlite3VdbeLoadString(v, 1, zOpt);
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
     }
-  }else
+    sqlite3VdbeReusable(v);
+  }
+  break;
 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
 
 #ifndef SQLITE_OMIT_WAL
   /*
-  **   PRAGMA [database.]wal_checkpoint = passive|full|restart
+  **   PRAGMA [schema.]wal_checkpoint = passive|full|restart|truncate
   **
   ** Checkpoint the database.
   */
-  if( sqlite3StrICmp(zLeft, "wal_checkpoint")==0 ){
+  case PragTyp_WAL_CHECKPOINT: {
+    static const char *azCol[] = { "busy", "log", "checkpointed" };
     int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);
     int eMode = SQLITE_CHECKPOINT_PASSIVE;
     if( zRight ){
@@ -91708,18 +112442,16 @@ SQLITE_PRIVATE void sqlite3Pragma(
         eMode = SQLITE_CHECKPOINT_FULL;
       }else if( sqlite3StrICmp(zRight, "restart")==0 ){
         eMode = SQLITE_CHECKPOINT_RESTART;
+      }else if( sqlite3StrICmp(zRight, "truncate")==0 ){
+        eMode = SQLITE_CHECKPOINT_TRUNCATE;
       }
     }
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
-    sqlite3VdbeSetNumCols(v, 3);
+    setAllColumnNames(v, 3, azCol);  assert( 3==ArraySize(azCol) );
     pParse->nMem = 3;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "busy", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "log", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "checkpointed", SQLITE_STATIC);
-
     sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);
     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
-  }else
+  }
+  break;
 
   /*
   **   PRAGMA wal_autocheckpoint
@@ -91729,75 +112461,147 @@ SQLITE_PRIVATE void sqlite3Pragma(
   ** after accumulating N frames in the log. Or query for the current value
   ** of N.
   */
-  if( sqlite3StrICmp(zLeft, "wal_autocheckpoint")==0 ){
+  case PragTyp_WAL_AUTOCHECKPOINT: {
     if( zRight ){
       sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));
     }
-    returnSingleInt(pParse, "wal_autocheckpoint", 
+    returnSingleInt(v, "wal_autocheckpoint", 
        db->xWalCallback==sqlite3WalDefaultHook ? 
            SQLITE_PTR_TO_INT(db->pWalArg) : 0);
-  }else
+  }
+  break;
 #endif
 
+  /*
+  **  PRAGMA shrink_memory
+  **
+  ** IMPLEMENTATION-OF: R-23445-46109 This pragma causes the database
+  ** connection on which it is invoked to free up as much memory as it
+  ** can, by calling sqlite3_db_release_memory().
+  */
+  case PragTyp_SHRINK_MEMORY: {
+    sqlite3_db_release_memory(db);
+    break;
+  }
+
+  /*
+  **   PRAGMA busy_timeout
+  **   PRAGMA busy_timeout = N
+  **
+  ** Call sqlite3_busy_timeout(db, N).  Return the current timeout value
+  ** if one is set.  If no busy handler or a different busy handler is set
+  ** then 0 is returned.  Setting the busy_timeout to 0 or negative
+  ** disables the timeout.
+  */
+  /*case PragTyp_BUSY_TIMEOUT*/ default: {
+    assert( pPragma->ePragTyp==PragTyp_BUSY_TIMEOUT );
+    if( zRight ){
+      sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
+    }
+    returnSingleInt(v, "timeout",  db->busyTimeout);
+    break;
+  }
+
+  /*
+  **   PRAGMA soft_heap_limit
+  **   PRAGMA soft_heap_limit = N
+  **
+  ** IMPLEMENTATION-OF: R-26343-45930 This pragma invokes the
+  ** sqlite3_soft_heap_limit64() interface with the argument N, if N is
+  ** specified and is a non-negative integer.
+  ** IMPLEMENTATION-OF: R-64451-07163 The soft_heap_limit pragma always
+  ** returns the same integer that would be returned by the
+  ** sqlite3_soft_heap_limit64(-1) C-language function.
+  */
+  case PragTyp_SOFT_HEAP_LIMIT: {
+    sqlite3_int64 N;
+    if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
+      sqlite3_soft_heap_limit64(N);
+    }
+    returnSingleInt(v, "soft_heap_limit",  sqlite3_soft_heap_limit64(-1));
+    break;
+  }
+
+  /*
+  **   PRAGMA threads
+  **   PRAGMA threads = N
+  **
+  ** Configure the maximum number of worker threads.  Return the new
+  ** maximum, which might be less than requested.
+  */
+  case PragTyp_THREADS: {
+    sqlite3_int64 N;
+    if( zRight
+     && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK
+     && N>=0
+    ){
+      sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));
+    }
+    returnSingleInt(v, "threads",
+                    sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
+    break;
+  }
+
 #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
   /*
   ** Report the current state of file logs for all databases
   */
-  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
+  case PragTyp_LOCK_STATUS: {
     static const char *const azLockName[] = {
       "unlocked", "shared", "reserved", "pending", "exclusive"
     };
+    static const char *azCol[] = { "database", "status" };
     int i;
-    sqlite3VdbeSetNumCols(v, 2);
+    setAllColumnNames(v, 2, azCol); assert( 2==ArraySize(azCol) );
     pParse->nMem = 2;
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", SQLITE_STATIC);
-    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", SQLITE_STATIC);
     for(i=0; i<db->nDb; i++){
       Btree *pBt;
-      Pager *pPager;
       const char *zState = "unknown";
       int j;
       if( db->aDb[i].zName==0 ) continue;
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC);
       pBt = db->aDb[i].pBt;
-      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
+      if( pBt==0 || sqlite3BtreePager(pBt)==0 ){
         zState = "closed";
       }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0, 
                                      SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
          zState = azLockName[j];
       }
-      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
+      sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zName, zState);
       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
     }
-
-  }else
+    break;
+  }
 #endif
 
 #ifdef SQLITE_HAS_CODEC
-  if( sqlite3StrICmp(zLeft, "key")==0 && zRight ){
-    sqlite3_key(db, zRight, sqlite3Strlen30(zRight));
-  }else
-  if( sqlite3StrICmp(zLeft, "rekey")==0 && zRight ){
-    sqlite3_rekey(db, zRight, sqlite3Strlen30(zRight));
-  }else
-  if( zRight && (sqlite3StrICmp(zLeft, "hexkey")==0 ||
-                 sqlite3StrICmp(zLeft, "hexrekey")==0) ){
-    int i, h1, h2;
-    char zKey[40];
-    for(i=0; (h1 = zRight[i])!=0 && (h2 = zRight[i+1])!=0; i+=2){
-      h1 += 9*(1&(h1>>6));
-      h2 += 9*(1&(h2>>6));
-      zKey[i/2] = (h2 & 0x0f) | ((h1 & 0xf)<<4);
-    }
-    if( (zLeft[3] & 0xf)==0xb ){
-      sqlite3_key(db, zKey, i/2);
-    }else{
-      sqlite3_rekey(db, zKey, i/2);
+  case PragTyp_KEY: {
+    if( zRight ) sqlite3_key_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
+    break;
+  }
+  case PragTyp_REKEY: {
+    if( zRight ) sqlite3_rekey_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
+    break;
+  }
+  case PragTyp_HEXKEY: {
+    if( zRight ){
+      u8 iByte;
+      int i;
+      char zKey[40];
+      for(i=0, iByte=0; i<sizeof(zKey)*2 && sqlite3Isxdigit(zRight[i]); i++){
+        iByte = (iByte<<4) + sqlite3HexToInt(zRight[i]);
+        if( (i&1)!=0 ) zKey[i/2] = iByte;
+      }
+      if( (zLeft[3] & 0xf)==0xb ){
+        sqlite3_key_v2(db, zDb, zKey, i/2);
+      }else{
+        sqlite3_rekey_v2(db, zDb, zKey, i/2);
+      }
     }
-  }else
+    break;
+  }
 #endif
 #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
-  if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){
+  case PragTyp_ACTIVATE_EXTENSIONS: if( zRight ){
 #ifdef SQLITE_HAS_CODEC
     if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
       sqlite3_activate_see(&zRight[4]);
@@ -91808,23 +112612,12 @@ SQLITE_PRIVATE void sqlite3Pragma(
       sqlite3_activate_cerod(&zRight[6]);
     }
 #endif
-  }else
+  }
+  break;
 #endif
 
- 
-  {/* Empty ELSE clause */}
+  } /* End of the PRAGMA switch */
 
-  /*
-  ** Reset the safety level, in case the fullfsync flag or synchronous
-  ** setting changed.
-  */
-#ifndef SQLITE_OMIT_PAGER_PRAGMAS
-  if( db->autoCommit ){
-    sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
-               (db->flags&SQLITE_FullFSync)!=0,
-               (db->flags&SQLITE_CkptFullFSync)!=0);
-  }
-#endif
 pragma_out:
   sqlite3DbFree(db, zLeft);
   sqlite3DbFree(db, zRight);
@@ -91849,6 +112642,7 @@ pragma_out:
 ** interface, and routines that contribute to loading the database schema
 ** from disk.
 */
+/* #include "sqliteInt.h" */
 
 /*
 ** Fill the InitData structure with an error message that indicates
@@ -91861,15 +112655,14 @@ static void corruptSchema(
 ){
   sqlite3 *db = pData->db;
   if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){
+    char *z;
     if( zObj==0 ) zObj = "?";
-    sqlite3SetString(pData->pzErrMsg, db,
-      "malformed database schema (%s)", zObj);
-    if( zExtra ){
-      *pData->pzErrMsg = sqlite3MAppendf(db, *pData->pzErrMsg, 
-                                 "%s - %s", *pData->pzErrMsg, zExtra);
-    }
+    z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj);
+    if( zExtra ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra);
+    sqlite3DbFree(db, *pData->pzErrMsg);
+    *pData->pzErrMsg = z;
   }
-  pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT;
+  pData->rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_CORRUPT_BKPT;
 }
 
 /*
@@ -91902,7 +112695,7 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
   if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
   if( argv[1]==0 ){
     corruptSchema(pData, argv[0], 0);
-  }else if( argv[2] && argv[2][0] ){
+  }else if( sqlite3_strnicmp(argv[2],"create ",7)==0 ){
     /* Call the parser to process a CREATE TABLE, INDEX or VIEW.
     ** But because db->init.busy is set to 1, no VDBE code is generated
     ** or executed.  All the parser does is build the internal data
@@ -91926,15 +112719,15 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
       }else{
         pData->rc = rc;
         if( rc==SQLITE_NOMEM ){
-          db->mallocFailed = 1;
+          sqlite3OomFault(db);
         }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
           corruptSchema(pData, argv[0], sqlite3_errmsg(db));
         }
       }
     }
     sqlite3_finalize(pStmt);
-  }else if( argv[0]==0 ){
-    corruptSchema(pData, 0, 0);
+  }else if( argv[0]==0 || (argv[2]!=0 && argv[2][0]!=0) ){
+    corruptSchema(pData, argv[0], 0);
   }else{
     /* If the SQL column is blank it means this is an index that
     ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
@@ -91969,62 +112762,30 @@ SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char
 static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   int rc;
   int i;
+#ifndef SQLITE_OMIT_DEPRECATED
   int size;
-  Table *pTab;
+#endif
   Db *pDb;
   char const *azArg[4];
   int meta[5];
   InitData initData;
-  char const *zMasterSchema;
-  char const *zMasterName;
+  const char *zMasterName;
   int openedTransaction = 0;
 
-  /*
-  ** The master database table has a structure like this
-  */
-  static const char master_schema[] = 
-     "CREATE TABLE sqlite_master(\n"
-     "  type text,\n"
-     "  name text,\n"
-     "  tbl_name text,\n"
-     "  rootpage integer,\n"
-     "  sql text\n"
-     ")"
-  ;
-#ifndef SQLITE_OMIT_TEMPDB
-  static const char temp_master_schema[] = 
-     "CREATE TEMP TABLE sqlite_temp_master(\n"
-     "  type text,\n"
-     "  name text,\n"
-     "  tbl_name text,\n"
-     "  rootpage integer,\n"
-     "  sql text\n"
-     ")"
-  ;
-#else
-  #define temp_master_schema 0
-#endif
-
   assert( iDb>=0 && iDb<db->nDb );
   assert( db->aDb[iDb].pSchema );
   assert( sqlite3_mutex_held(db->mutex) );
   assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
 
-  /* zMasterSchema and zInitScript are set to point at the master schema
-  ** and initialisation script appropriate for the database being
-  ** initialised. zMasterName is the name of the master table.
-  */
-  if( !OMIT_TEMPDB && iDb==1 ){
-    zMasterSchema = temp_master_schema;
-  }else{
-    zMasterSchema = master_schema;
-  }
-  zMasterName = SCHEMA_TABLE(iDb);
-
-  /* Construct the schema tables.  */
-  azArg[0] = zMasterName;
+  /* Construct the in-memory representation schema tables (sqlite_master or
+  ** sqlite_temp_master) by invoking the parser directly.  The appropriate
+  ** table name will be inserted automatically by the parser so we can just
+  ** use the abbreviation "x" here.  The parser will also automatically tag
+  ** the schema table as read-only. */
+  azArg[0] = zMasterName = SCHEMA_TABLE(iDb);
   azArg[1] = "1";
-  azArg[2] = zMasterSchema;
+  azArg[2] = "CREATE TABLE x(type text,name text,tbl_name text,"
+                            "rootpage integer,sql text)";
   azArg[3] = 0;
   initData.db = db;
   initData.iDb = iDb;
@@ -92035,10 +112796,6 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
     rc = initData.rc;
     goto error_out;
   }
-  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
-  if( ALWAYS(pTab) ){
-    pTab->tabFlags |= TF_Readonly;
-  }
 
   /* Create a cursor to hold the database open
   */
@@ -92057,7 +112814,7 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){
     rc = sqlite3BtreeBeginTrans(pDb->pBt, 0);
     if( rc!=SQLITE_OK ){
-      sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc));
+      sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
       goto initone_error_out;
     }
     openedTransaction = 1;
@@ -92092,12 +112849,15 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   */
   if( meta[BTREE_TEXT_ENCODING-1] ){  /* text encoding */
     if( iDb==0 ){
+#ifndef SQLITE_OMIT_UTF16
       u8 encoding;
       /* If opening the main database, set ENC(db). */
       encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
       if( encoding==0 ) encoding = SQLITE_UTF8;
       ENC(db) = encoding;
-      db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
+#else
+      ENC(db) = SQLITE_UTF8;
+#endif
     }else{
       /* If opening an attached database, the encoding much match ENC(db) */
       if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){
@@ -92113,9 +112873,13 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   pDb->pSchema->enc = ENC(db);
 
   if( pDb->pSchema->cache_size==0 ){
+#ifndef SQLITE_OMIT_DEPRECATED
     size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);
     if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
     pDb->pSchema->cache_size = size;
+#else
+    pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE;
+#endif
     sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
   }
 
@@ -92150,11 +112914,11 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   {
     char *zSql;
     zSql = sqlite3MPrintf(db, 
-        "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid",
+        "SELECT name, rootpage, sql FROM \"%w\".%s ORDER BY rowid",
         db->aDb[iDb].zName, zMasterName);
 #ifndef SQLITE_OMIT_AUTHORIZATION
     {
-      int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+      sqlite3_xauth xAuth;
       xAuth = db->xAuth;
       db->xAuth = 0;
 #endif
@@ -92172,8 +112936,8 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
 #endif
   }
   if( db->mallocFailed ){
-    rc = SQLITE_NOMEM;
-    sqlite3ResetInternalSchema(db, -1);
+    rc = SQLITE_NOMEM_BKPT;
+    sqlite3ResetAllSchemasOfConnection(db);
   }
   if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
     /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
@@ -92200,7 +112964,7 @@ initone_error_out:
 
 error_out:
   if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-    db->mallocFailed = 1;
+    sqlite3OomFault(db);
   }
   return rc;
 }
@@ -92220,26 +112984,29 @@ SQLITE_PRIVATE int sqlite3Init(sqlite3 *db, char **pzErrMsg){
   int commit_internal = !(db->flags&SQLITE_InternChanges);
   
   assert( sqlite3_mutex_held(db->mutex) );
+  assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );
+  assert( db->init.busy==0 );
   rc = SQLITE_OK;
   db->init.busy = 1;
+  ENC(db) = SCHEMA_ENC(db);
   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
     if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
     rc = sqlite3InitOne(db, i, pzErrMsg);
     if( rc ){
-      sqlite3ResetInternalSchema(db, i);
+      sqlite3ResetOneSchema(db, i);
     }
   }
 
-  /* Once all the other databases have been initialised, load the schema
+  /* Once all the other databases have been initialized, load the schema
   ** for the TEMP database. This is loaded last, as the TEMP database
   ** schema may contain references to objects in other databases.
   */
 #ifndef SQLITE_OMIT_TEMPDB
-  if( rc==SQLITE_OK && ALWAYS(db->nDb>1)
-                    && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
+  assert( db->nDb>1 );
+  if( rc==SQLITE_OK && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
     rc = sqlite3InitOne(db, 1, pzErrMsg);
     if( rc ){
-      sqlite3ResetInternalSchema(db, 1);
+      sqlite3ResetOneSchema(db, 1);
     }
   }
 #endif
@@ -92253,7 +113020,7 @@ SQLITE_PRIVATE int sqlite3Init(sqlite3 *db, char **pzErrMsg){
 }
 
 /*
-** This routine is a no-op if the database schema is already initialised.
+** This routine is a no-op if the database schema is already initialized.
 ** Otherwise, the schema is loaded. An error code is returned.
 */
 SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse){
@@ -92295,7 +113062,7 @@ static void schemaIsValid(Parse *pParse){
     if( !sqlite3BtreeIsInReadTrans(pBt) ){
       rc = sqlite3BtreeBeginTrans(pBt, 0);
       if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
-        db->mallocFailed = 1;
+        sqlite3OomFault(db);
       }
       if( rc!=SQLITE_OK ) return;
       openedTransaction = 1;
@@ -92307,7 +113074,7 @@ static void schemaIsValid(Parse *pParse){
     sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){
-      sqlite3ResetInternalSchema(db, iDb);
+      sqlite3ResetOneSchema(db, iDb);
       pParse->rc = SQLITE_SCHEMA;
     }
 
@@ -92351,6 +113118,22 @@ SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
 }
 
 /*
+** Free all memory allocations in the pParse object
+*/
+SQLITE_PRIVATE void sqlite3ParserReset(Parse *pParse){
+  if( pParse ){
+    sqlite3 *db = pParse->db;
+    sqlite3DbFree(db, pParse->aLabel);
+    sqlite3ExprListDelete(db, pParse->pConstExpr);
+    if( db ){
+      assert( db->lookaside.bDisable >= pParse->disableLookaside );
+      db->lookaside.bDisable -= pParse->disableLookaside;
+    }
+    pParse->disableLookaside = 0;
+  }
+}
+
+/*
 ** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
 */
 static int sqlite3Prepare(
@@ -92370,12 +113153,12 @@ static int sqlite3Prepare(
   /* Allocate the parsing context */
   pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
   if( pParse==0 ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
     goto end_prepare;
   }
   pParse->pReprepare = pReprepare;
   assert( ppStmt && *ppStmt==0 );
-  assert( !db->mallocFailed );
+  /* assert( !db->mallocFailed ); // not true with SQLITE_USE_ALLOCA */
   assert( sqlite3_mutex_held(db->mutex) );
 
   /* Check to verify that it is possible to get a read lock on all
@@ -92408,7 +113191,7 @@ static int sqlite3Prepare(
       rc = sqlite3BtreeSchemaLocked(pBt);
       if( rc ){
         const char *zDb = db->aDb[i].zName;
-        sqlite3Error(db, rc, "database schema is locked: %s", zDb);
+        sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);
         testcase( db->flags & SQLITE_ReadUncommitted );
         goto end_prepare;
       }
@@ -92418,39 +113201,36 @@ static int sqlite3Prepare(
   sqlite3VtabUnlockList(db);
 
   pParse->db = db;
-  pParse->nQueryLoop = (double)1;
+  pParse->nQueryLoop = 0;  /* Logarithmic, so 0 really means 1 */
   if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
     char *zSqlCopy;
     int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
     testcase( nBytes==mxLen );
     testcase( nBytes==mxLen+1 );
     if( nBytes>mxLen ){
-      sqlite3Error(db, SQLITE_TOOBIG, "statement too long");
+      sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long");
       rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
       goto end_prepare;
     }
     zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
     if( zSqlCopy ){
       sqlite3RunParser(pParse, zSqlCopy, &zErrMsg);
-      sqlite3DbFree(db, zSqlCopy);
       pParse->zTail = &zSql[pParse->zTail-zSqlCopy];
+      sqlite3DbFree(db, zSqlCopy);
     }else{
       pParse->zTail = &zSql[nBytes];
     }
   }else{
     sqlite3RunParser(pParse, zSql, &zErrMsg);
   }
-  assert( 1==(int)pParse->nQueryLoop );
+  assert( 0==pParse->nQueryLoop );
 
-  if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
-  }
   if( pParse->rc==SQLITE_DONE ) pParse->rc = SQLITE_OK;
   if( pParse->checkSchema ){
     schemaIsValid(pParse);
   }
   if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
+    pParse->rc = SQLITE_NOMEM_BKPT;
   }
   if( pzTail ){
     *pzTail = pParse->zTail;
@@ -92480,7 +113260,6 @@ static int sqlite3Prepare(
   }
 #endif
 
-  assert( db->init.busy==0 || saveSqlFlag==0 );
   if( db->init.busy==0 ){
     Vdbe *pVdbe = pParse->pVdbe;
     sqlite3VdbeSetSql(pVdbe, zSql, (int)(pParse->zTail-zSql), saveSqlFlag);
@@ -92493,10 +113272,10 @@ static int sqlite3Prepare(
   }
 
   if( zErrMsg ){
-    sqlite3Error(db, rc, "%s", zErrMsg);
+    sqlite3ErrorWithMsg(db, rc, "%s", zErrMsg);
     sqlite3DbFree(db, zErrMsg);
   }else{
-    sqlite3Error(db, rc, 0);
+    sqlite3Error(db, rc);
   }
 
   /* Delete any TriggerPrg structures allocated while parsing this statement. */
@@ -92508,6 +113287,7 @@ static int sqlite3Prepare(
 
 end_prepare:
 
+  sqlite3ParserReset(pParse);
   sqlite3StackFree(db, pParse);
   rc = sqlite3ApiExit(db, rc);
   assert( (rc&db->errMask)==rc );
@@ -92523,9 +113303,12 @@ static int sqlite3LockAndPrepare(
   const char **pzTail       /* OUT: End of parsed string */
 ){
   int rc;
-  assert( ppStmt!=0 );
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   *ppStmt = 0;
-  if( !sqlite3SafetyCheckOk(db) ){
+  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
     return SQLITE_MISUSE_BKPT;
   }
   sqlite3_mutex_enter(db->mutex);
@@ -92537,6 +113320,7 @@ static int sqlite3LockAndPrepare(
   }
   sqlite3BtreeLeaveAll(db);
   sqlite3_mutex_leave(db->mutex);
+  assert( rc==SQLITE_OK || *ppStmt==0 );
   return rc;
 }
 
@@ -92562,7 +113346,7 @@ SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){
   rc = sqlite3LockAndPrepare(db, zSql, -1, 0, p, &pNew, 0);
   if( rc ){
     if( rc==SQLITE_NOMEM ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
     }
     assert( pNew==0 );
     return rc;
@@ -92585,7 +113369,7 @@ SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){
 ** and the statement is automatically recompiled if an schema change
 ** occurs.
 */
-SQLITE_API int sqlite3_prepare(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare(
   sqlite3 *db,              /* Database handle. */
   const char *zSql,         /* UTF-8 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
@@ -92597,7 +113381,7 @@ SQLITE_API int sqlite3_prepare(
   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
   return rc;
 }
-SQLITE_API int sqlite3_prepare_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2(
   sqlite3 *db,              /* Database handle. */
   const char *zSql,         /* UTF-8 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
@@ -92631,11 +113415,19 @@ static int sqlite3Prepare16(
   const char *zTail8 = 0;
   int rc = SQLITE_OK;
 
-  assert( ppStmt );
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   *ppStmt = 0;
-  if( !sqlite3SafetyCheckOk(db) ){
+  if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
     return SQLITE_MISUSE_BKPT;
   }
+  if( nBytes>=0 ){
+    int sz;
+    const char *z = (const char*)zSql;
+    for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
+    nBytes = sz;
+  }
   sqlite3_mutex_enter(db->mutex);
   zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
   if( zSql8 ){
@@ -92665,7 +113457,7 @@ static int sqlite3Prepare16(
 ** and the statement is automatically recompiled if an schema change
 ** occurs.
 */
-SQLITE_API int sqlite3_prepare16(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare16(
   sqlite3 *db,              /* Database handle. */ 
   const void *zSql,         /* UTF-16 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
@@ -92677,7 +113469,7 @@ SQLITE_API int sqlite3_prepare16(
   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */
   return rc;
 }
-SQLITE_API int sqlite3_prepare16_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2(
   sqlite3 *db,              /* Database handle. */ 
   const void *zSql,         /* UTF-16 encoded SQL statement. */
   int nBytes,               /* Length of zSql in bytes. */
@@ -92708,22 +113500,74 @@ SQLITE_API int sqlite3_prepare16_v2(
 ** This file contains C code routines that are called by the parser
 ** to handle SELECT statements in SQLite.
 */
+/* #include "sqliteInt.h" */
+
+/*
+** Trace output macros
+*/
+#if SELECTTRACE_ENABLED
+/***/ int sqlite3SelectTrace = 0;
+# define SELECTTRACE(K,P,S,X)  \
+  if(sqlite3SelectTrace&(K))   \
+    sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",\
+        (S)->zSelName,(S)),\
+    sqlite3DebugPrintf X
+#else
+# define SELECTTRACE(K,P,S,X)
+#endif
 
 
 /*
-** Delete all the content of a Select structure but do not deallocate
-** the select structure itself.
+** An instance of the following object is used to record information about
+** how to process the DISTINCT keyword, to simplify passing that information
+** into the selectInnerLoop() routine.
 */
-static void clearSelect(sqlite3 *db, Select *p){
-  sqlite3ExprListDelete(db, p->pEList);
-  sqlite3SrcListDelete(db, p->pSrc);
-  sqlite3ExprDelete(db, p->pWhere);
-  sqlite3ExprListDelete(db, p->pGroupBy);
-  sqlite3ExprDelete(db, p->pHaving);
-  sqlite3ExprListDelete(db, p->pOrderBy);
-  sqlite3SelectDelete(db, p->pPrior);
-  sqlite3ExprDelete(db, p->pLimit);
-  sqlite3ExprDelete(db, p->pOffset);
+typedef struct DistinctCtx DistinctCtx;
+struct DistinctCtx {
+  u8 isTnct;      /* True if the DISTINCT keyword is present */
+  u8 eTnctType;   /* One of the WHERE_DISTINCT_* operators */
+  int tabTnct;    /* Ephemeral table used for DISTINCT processing */
+  int addrTnct;   /* Address of OP_OpenEphemeral opcode for tabTnct */
+};
+
+/*
+** An instance of the following object is used to record information about
+** the ORDER BY (or GROUP BY) clause of query is being coded.
+*/
+typedef struct SortCtx SortCtx;
+struct SortCtx {
+  ExprList *pOrderBy;   /* The ORDER BY (or GROUP BY clause) */
+  int nOBSat;           /* Number of ORDER BY terms satisfied by indices */
+  int iECursor;         /* Cursor number for the sorter */
+  int regReturn;        /* Register holding block-output return address */
+  int labelBkOut;       /* Start label for the block-output subroutine */
+  int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */
+  int labelDone;        /* Jump here when done, ex: LIMIT reached */
+  u8 sortFlags;         /* Zero or more SORTFLAG_* bits */
+  u8 bOrderedInnerLoop; /* ORDER BY correctly sorts the inner loop */
+};
+#define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */
+
+/*
+** Delete all the content of a Select structure.  Deallocate the structure
+** itself only if bFree is true.
+*/
+static void clearSelect(sqlite3 *db, Select *p, int bFree){
+  while( p ){
+    Select *pPrior = p->pPrior;
+    sqlite3ExprListDelete(db, p->pEList);
+    sqlite3SrcListDelete(db, p->pSrc);
+    sqlite3ExprDelete(db, p->pWhere);
+    sqlite3ExprListDelete(db, p->pGroupBy);
+    sqlite3ExprDelete(db, p->pHaving);
+    sqlite3ExprListDelete(db, p->pOrderBy);
+    sqlite3ExprDelete(db, p->pLimit);
+    sqlite3ExprDelete(db, p->pOffset);
+    if( p->pWith ) sqlite3WithDelete(db, p->pWith);
+    if( bFree ) sqlite3DbFree(db, p);
+    p = pPrior;
+    bFree = 1;
+  }
 }
 
 /*
@@ -92731,10 +113575,10 @@ static void clearSelect(sqlite3 *db, Select *p){
 */
 SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
   pDest->eDest = (u8)eDest;
-  pDest->iParm = iParm;
-  pDest->affinity = 0;
-  pDest->iMem = 0;
-  pDest->nMem = 0;
+  pDest->iSDParm = iParm;
+  pDest->affSdst = 0;
+  pDest->iSdst = 0;
+  pDest->nSdst = 0;
 }
 
 
@@ -92750,40 +113594,46 @@ SQLITE_PRIVATE Select *sqlite3SelectNew(
   ExprList *pGroupBy,   /* the GROUP BY clause */
   Expr *pHaving,        /* the HAVING clause */
   ExprList *pOrderBy,   /* the ORDER BY clause */
-  int isDistinct,       /* true if the DISTINCT keyword is present */
+  u32 selFlags,         /* Flag parameters, such as SF_Distinct */
   Expr *pLimit,         /* LIMIT value.  NULL means not used */
   Expr *pOffset         /* OFFSET value.  NULL means no offset */
 ){
   Select *pNew;
   Select standin;
   sqlite3 *db = pParse->db;
-  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
-  assert( db->mallocFailed || !pOffset || pLimit ); /* OFFSET implies LIMIT */
+  pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );
   if( pNew==0 ){
     assert( db->mallocFailed );
     pNew = &standin;
-    memset(pNew, 0, sizeof(*pNew));
   }
   if( pEList==0 ){
-    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0));
+    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ASTERISK,0));
   }
   pNew->pEList = pEList;
+  pNew->op = TK_SELECT;
+  pNew->selFlags = selFlags;
+  pNew->iLimit = 0;
+  pNew->iOffset = 0;
+#if SELECTTRACE_ENABLED
+  pNew->zSelName[0] = 0;
+#endif
+  pNew->addrOpenEphm[0] = -1;
+  pNew->addrOpenEphm[1] = -1;
+  pNew->nSelectRow = 0;
+  if( pSrc==0 ) pSrc = sqlite3DbMallocZero(db, sizeof(*pSrc));
   pNew->pSrc = pSrc;
   pNew->pWhere = pWhere;
   pNew->pGroupBy = pGroupBy;
   pNew->pHaving = pHaving;
   pNew->pOrderBy = pOrderBy;
-  pNew->selFlags = isDistinct ? SF_Distinct : 0;
-  pNew->op = TK_SELECT;
+  pNew->pPrior = 0;
+  pNew->pNext = 0;
   pNew->pLimit = pLimit;
   pNew->pOffset = pOffset;
-  assert( pOffset==0 || pLimit!=0 );
-  pNew->addrOpenEphm[0] = -1;
-  pNew->addrOpenEphm[1] = -1;
-  pNew->addrOpenEphm[2] = -1;
+  pNew->pWith = 0;
+  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0 || db->mallocFailed!=0 );
   if( db->mallocFailed ) {
-    clearSelect(db, pNew);
-    if( pNew!=&standin ) sqlite3DbFree(db, pNew);
+    clearSelect(db, pNew, pNew!=&standin);
     pNew = 0;
   }else{
     assert( pNew->pSrc!=0 || pParse->nErr>0 );
@@ -92792,18 +113642,35 @@ SQLITE_PRIVATE Select *sqlite3SelectNew(
   return pNew;
 }
 
+#if SELECTTRACE_ENABLED
+/*
+** Set the name of a Select object
+*/
+SQLITE_PRIVATE void sqlite3SelectSetName(Select *p, const char *zName){
+  if( p && zName ){
+    sqlite3_snprintf(sizeof(p->zSelName), p->zSelName, "%s", zName);
+  }
+}
+#endif
+
+
 /*
 ** Delete the given Select structure and all of its substructures.
 */
 SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3 *db, Select *p){
-  if( p ){
-    clearSelect(db, p);
-    sqlite3DbFree(db, p);
-  }
+  if( p ) clearSelect(db, p, 1);
+}
+
+/*
+** Return a pointer to the right-most SELECT statement in a compound.
+*/
+static Select *findRightmost(Select *p){
+  while( p->pNext ) p = p->pNext;
+  return p;
 }
 
 /*
-** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
+** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
 ** type of join.  Return an integer constant that expresses that type
 ** in terms of the following bit values:
 **
@@ -92958,8 +113825,8 @@ static void addWhereTerm(
   pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
   if( pEq && isOuterJoin ){
     ExprSetProperty(pEq, EP_FromJoin);
-    assert( !ExprHasAnyProperty(pEq, EP_TokenOnly|EP_Reduced) );
-    ExprSetIrreducible(pEq);
+    assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
+    ExprSetVVAProperty(pEq, EP_NoReduce);
     pEq->iRightJoinTable = (i16)pE2->iTable;
   }
   *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq);
@@ -92994,9 +113861,15 @@ static void addWhereTerm(
 static void setJoinExpr(Expr *p, int iTable){
   while( p ){
     ExprSetProperty(p, EP_FromJoin);
-    assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
-    ExprSetIrreducible(p);
+    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
+    ExprSetVVAProperty(p, EP_NoReduce);
     p->iRightJoinTable = (i16)iTable;
+    if( p->op==TK_FUNCTION && p->x.pList ){
+      int i;
+      for(i=0; i<p->x.pList->nExpr; i++){
+        setJoinExpr(p->x.pList->a[i].pExpr, iTable);
+      }
+    }
     setJoinExpr(p->pLeft, iTable);
     p = p->pRight;
   } 
@@ -93031,12 +113904,12 @@ static int sqliteProcessJoin(Parse *pParse, Select *p){
     int isOuter;
 
     if( NEVER(pLeftTab==0 || pRightTab==0) ) continue;
-    isOuter = (pRight->jointype & JT_OUTER)!=0;
+    isOuter = (pRight->fg.jointype & JT_OUTER)!=0;
 
     /* When the NATURAL keyword is present, add WHERE clause terms for
     ** every column that the two tables have in common.
     */
-    if( pRight->jointype & JT_NATURAL ){
+    if( pRight->fg.jointype & JT_NATURAL ){
       if( pRight->pOn || pRight->pUsing ){
         sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
            "an ON or USING clause", 0);
@@ -93104,49 +113977,132 @@ static int sqliteProcessJoin(Parse *pParse, Select *p){
   return 0;
 }
 
+/* Forward reference */
+static KeyInfo *keyInfoFromExprList(
+  Parse *pParse,       /* Parsing context */
+  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
+  int iStart,          /* Begin with this column of pList */
+  int nExtra           /* Add this many extra columns to the end */
+);
+
 /*
-** Insert code into "v" that will push the record on the top of the
-** stack into the sorter.
+** Generate code that will push the record in registers regData
+** through regData+nData-1 onto the sorter.
 */
 static void pushOntoSorter(
   Parse *pParse,         /* Parser context */
-  ExprList *pOrderBy,    /* The ORDER BY clause */
+  SortCtx *pSort,        /* Information about the ORDER BY clause */
   Select *pSelect,       /* The whole SELECT statement */
-  int regData            /* Register holding data to be sorted */
-){
-  Vdbe *v = pParse->pVdbe;
-  int nExpr = pOrderBy->nExpr;
-  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
-  int regRecord = sqlite3GetTempReg(pParse);
-  int op;
-  sqlite3ExprCacheClear(pParse);
-  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0);
-  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
-  sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1);
-  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);
-  if( pSelect->selFlags & SF_UseSorter ){
+  int regData,           /* First register holding data to be sorted */
+  int regOrigData,       /* First register holding data before packing */
+  int nData,             /* Number of elements in the data array */
+  int nPrefixReg         /* No. of reg prior to regData available for use */
+){
+  Vdbe *v = pParse->pVdbe;                         /* Stmt under construction */
+  int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0);
+  int nExpr = pSort->pOrderBy->nExpr;              /* No. of ORDER BY terms */
+  int nBase = nExpr + bSeq + nData;                /* Fields in sorter record */
+  int regBase;                                     /* Regs for sorter record */
+  int regRecord = ++pParse->nMem;                  /* Assembled sorter record */
+  int nOBSat = pSort->nOBSat;                      /* ORDER BY terms to skip */
+  int op;                            /* Opcode to add sorter record to sorter */
+  int iLimit;                        /* LIMIT counter */
+
+  assert( bSeq==0 || bSeq==1 );
+  assert( nData==1 || regData==regOrigData );
+  if( nPrefixReg ){
+    assert( nPrefixReg==nExpr+bSeq );
+    regBase = regData - nExpr - bSeq;
+  }else{
+    regBase = pParse->nMem + 1;
+    pParse->nMem += nBase;
+  }
+  assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );
+  iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
+  pSort->labelDone = sqlite3VdbeMakeLabel(v);
+  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
+                          SQLITE_ECEL_DUP|SQLITE_ECEL_REF);
+  if( bSeq ){
+    sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
+  }
+  if( nPrefixReg==0 ){
+    sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
+  }
+  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
+  if( nOBSat>0 ){
+    int regPrevKey;   /* The first nOBSat columns of the previous row */
+    int addrFirst;    /* Address of the OP_IfNot opcode */
+    int addrJmp;      /* Address of the OP_Jump opcode */
+    VdbeOp *pOp;      /* Opcode that opens the sorter */
+    int nKey;         /* Number of sorting key columns, including OP_Sequence */
+    KeyInfo *pKI;     /* Original KeyInfo on the sorter table */
+
+    regPrevKey = pParse->nMem+1;
+    pParse->nMem += pSort->nOBSat;
+    nKey = nExpr - pSort->nOBSat + bSeq;
+    if( bSeq ){
+      addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); 
+    }else{
+      addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor);
+    }
+    VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
+    pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
+    if( pParse->db->mallocFailed ) return;
+    pOp->p2 = nKey + nData;
+    pKI = pOp->p4.pKeyInfo;
+    memset(pKI->aSortOrder, 0, pKI->nField); /* Makes OP_Jump below testable */
+    sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);
+    testcase( pKI->nXField>2 );
+    pOp->p4.pKeyInfo = keyInfoFromExprList(pParse, pSort->pOrderBy, nOBSat,
+                                           pKI->nXField-1);
+    addrJmp = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
+    pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
+    pSort->regReturn = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
+    sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
+    if( iLimit ){
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);
+      VdbeCoverage(v);
+    }
+    sqlite3VdbeJumpHere(v, addrFirst);
+    sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
+    sqlite3VdbeJumpHere(v, addrJmp);
+  }
+  if( pSort->sortFlags & SORTFLAG_UseSorter ){
     op = OP_SorterInsert;
   }else{
     op = OP_IdxInsert;
   }
-  sqlite3VdbeAddOp2(v, op, pOrderBy->iECursor, regRecord);
-  sqlite3ReleaseTempReg(pParse, regRecord);
-  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
-  if( pSelect->iLimit ){
-    int addr1, addr2;
-    int iLimit;
-    if( pSelect->iOffset ){
-      iLimit = pSelect->iOffset+1;
-    }else{
-      iLimit = pSelect->iLimit;
+  sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
+  if( iLimit ){
+    int addr;
+    int r1 = 0;
+    /* Fill the sorter until it contains LIMIT+OFFSET entries.  (The iLimit
+    ** register is initialized with value of LIMIT+OFFSET.)  After the sorter
+    ** fills up, delete the least entry in the sorter after each insert.
+    ** Thus we never hold more than the LIMIT+OFFSET rows in memory at once */
+    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, 1); VdbeCoverage(v);
+    sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
+    if( pSort->bOrderedInnerLoop ){
+      r1 = ++pParse->nMem;
+      sqlite3VdbeAddOp3(v, OP_Column, pSort->iECursor, nExpr, r1);
+      VdbeComment((v, "seq"));
+    }
+    sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
+    if( pSort->bOrderedInnerLoop ){
+      /* If the inner loop is driven by an index such that values from
+      ** the same iteration of the inner loop are in sorted order, then
+      ** immediately jump to the next iteration of an inner loop if the
+      ** entry from the current iteration does not fit into the top
+      ** LIMIT+OFFSET entries of the sorter. */
+      int iBrk = sqlite3VdbeCurrentAddr(v) + 2;
+      sqlite3VdbeAddOp3(v, OP_Eq, regBase+nExpr, iBrk, r1);
+      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+      VdbeCoverage(v);
     }
-    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit);
-    sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1);
-    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
-    sqlite3VdbeJumpHere(v, addr1);
-    sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor);
-    sqlite3VdbeAddOp1(v, OP_Delete, pOrderBy->iECursor);
-    sqlite3VdbeJumpHere(v, addr2);
+    sqlite3VdbeJumpHere(v, addr);
   }
 }
 
@@ -93155,16 +114111,12 @@ static void pushOntoSorter(
 */
 static void codeOffset(
   Vdbe *v,          /* Generate code into this VM */
-  Select *p,        /* The SELECT statement being coded */
+  int iOffset,      /* Register holding the offset counter */
   int iContinue     /* Jump here to skip the current record */
 ){
-  if( p->iOffset && iContinue!=0 ){
-    int addr;
-    sqlite3VdbeAddOp2(v, OP_AddImm, p->iOffset, -1);
-    addr = sqlite3VdbeAddOp1(v, OP_IfNeg, p->iOffset);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue);
-    VdbeComment((v, "skip OFFSET records"));
-    sqlite3VdbeJumpHere(v, addr);
+  if( iOffset>0 ){
+    sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);
+    VdbeComment((v, "OFFSET"));
   }
 }
 
@@ -93189,7 +114141,7 @@ static void codeDistinct(
 
   v = pParse->pVdbe;
   r1 = sqlite3GetTempReg(pParse);
-  sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N);
+  sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
   sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
   sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
   sqlite3ReleaseTempReg(pParse, r1);
@@ -93223,19 +114175,18 @@ static int checkForMultiColumnSelectError(
 ** This routine generates the code for the inside of the inner loop
 ** of a SELECT.
 **
-** If srcTab and nColumn are both zero, then the pEList expressions
-** are evaluated in order to get the data for this row.  If nColumn>0
-** then data is pulled from srcTab and pEList is used only to get the
-** datatypes for each column.
+** If srcTab is negative, then the pEList expressions
+** are evaluated in order to get the data for this row.  If srcTab is
+** zero or more, then data is pulled from srcTab and pEList is used only 
+** to get number columns and the datatype for each column.
 */
 static void selectInnerLoop(
   Parse *pParse,          /* The parser context */
   Select *p,              /* The complete select statement being coded */
   ExprList *pEList,       /* List of values being extracted */
   int srcTab,             /* Pull data from this table */
-  int nColumn,            /* Number of columns in the source table */
-  ExprList *pOrderBy,     /* If not NULL, sort results using this key */
-  int distinct,           /* If >=0, make sure results are distinct */
+  SortCtx *pSort,         /* If not NULL, info on how to process ORDER BY */
+  DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */
   SelectDest *pDest,      /* How to dispose of the results */
   int iContinue,          /* Jump here to continue with next row */
   int iBreak              /* Jump here to break out of the inner loop */
@@ -93245,55 +114196,118 @@ static void selectInnerLoop(
   int hasDistinct;        /* True if the DISTINCT keyword is present */
   int regResult;              /* Start of memory holding result set */
   int eDest = pDest->eDest;   /* How to dispose of results */
-  int iParm = pDest->iParm;   /* First argument to disposal method */
+  int iParm = pDest->iSDParm; /* First argument to disposal method */
   int nResultCol;             /* Number of result columns */
+  int nPrefixReg = 0;         /* Number of extra registers before regResult */
 
   assert( v );
-  if( NEVER(v==0) ) return;
   assert( pEList!=0 );
-  hasDistinct = distinct>=0;
-  if( pOrderBy==0 && !hasDistinct ){
-    codeOffset(v, p, iContinue);
+  hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
+  if( pSort && pSort->pOrderBy==0 ) pSort = 0;
+  if( pSort==0 && !hasDistinct ){
+    assert( iContinue!=0 );
+    codeOffset(v, p->iOffset, iContinue);
   }
 
   /* Pull the requested columns.
   */
-  if( nColumn>0 ){
-    nResultCol = nColumn;
-  }else{
-    nResultCol = pEList->nExpr;
-  }
-  if( pDest->iMem==0 ){
-    pDest->iMem = pParse->nMem+1;
-    pDest->nMem = nResultCol;
+  nResultCol = pEList->nExpr;
+
+  if( pDest->iSdst==0 ){
+    if( pSort ){
+      nPrefixReg = pSort->pOrderBy->nExpr;
+      if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++;
+      pParse->nMem += nPrefixReg;
+    }
+    pDest->iSdst = pParse->nMem+1;
+    pParse->nMem += nResultCol;
+  }else if( pDest->iSdst+nResultCol > pParse->nMem ){
+    /* This is an error condition that can result, for example, when a SELECT
+    ** on the right-hand side of an INSERT contains more result columns than
+    ** there are columns in the table on the left.  The error will be caught
+    ** and reported later.  But we need to make sure enough memory is allocated
+    ** to avoid other spurious errors in the meantime. */
     pParse->nMem += nResultCol;
-  }else{ 
-    assert( pDest->nMem==nResultCol );
   }
-  regResult = pDest->iMem;
-  if( nColumn>0 ){
-    for(i=0; i<nColumn; i++){
+  pDest->nSdst = nResultCol;
+  regResult = pDest->iSdst;
+  if( srcTab>=0 ){
+    for(i=0; i<nResultCol; i++){
       sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
+      VdbeComment((v, "%s", pEList->a[i].zName));
     }
   }else if( eDest!=SRT_Exists ){
     /* If the destination is an EXISTS(...) expression, the actual
     ** values returned by the SELECT are not required.
     */
-    sqlite3ExprCacheClear(pParse);
-    sqlite3ExprCodeExprList(pParse, pEList, regResult, eDest==SRT_Output);
+    u8 ecelFlags;
+    if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){
+      ecelFlags = SQLITE_ECEL_DUP;
+    }else{
+      ecelFlags = 0;
+    }
+    sqlite3ExprCodeExprList(pParse, pEList, regResult, 0, ecelFlags);
   }
-  nColumn = nResultCol;
 
   /* If the DISTINCT keyword was present on the SELECT statement
   ** and this row has been seen before, then do not make this row
   ** part of the result.
   */
   if( hasDistinct ){
-    assert( pEList!=0 );
-    assert( pEList->nExpr==nColumn );
-    codeDistinct(pParse, distinct, iContinue, nColumn, regResult);
-    if( pOrderBy==0 ){
-      codeOffset(v, p, iContinue);
+    switch( pDistinct->eTnctType ){
+      case WHERE_DISTINCT_ORDERED: {
+        VdbeOp *pOp;            /* No longer required OpenEphemeral instr. */
+        int iJump;              /* Jump destination */
+        int regPrev;            /* Previous row content */
+
+        /* Allocate space for the previous row */
+        regPrev = pParse->nMem+1;
+        pParse->nMem += nResultCol;
+
+        /* Change the OP_OpenEphemeral coded earlier to an OP_Null
+        ** sets the MEM_Cleared bit on the first register of the
+        ** previous value.  This will cause the OP_Ne below to always
+        ** fail on the first iteration of the loop even if the first
+        ** row is all NULLs.
+        */
+        sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
+        pOp = sqlite3VdbeGetOp(v, pDistinct->addrTnct);
+        pOp->opcode = OP_Null;
+        pOp->p1 = 1;
+        pOp->p2 = regPrev;
+
+        iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;
+        for(i=0; i<nResultCol; i++){
+          CollSeq *pColl = sqlite3ExprCollSeq(pParse, pEList->a[i].pExpr);
+          if( i<nResultCol-1 ){
+            sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);
+            VdbeCoverage(v);
+          }else{
+            sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);
+            VdbeCoverage(v);
+           }
+          sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
+          sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+        }
+        assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed );
+        sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);
+        break;
+      }
+
+      case WHERE_DISTINCT_UNIQUE: {
+        sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
+        break;
+      }
+
+      default: {
+        assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
+        codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,
+                     regResult);
+        break;
+      }
+    }
+    if( pSort==0 ){
+      codeOffset(v, p->iOffset, iContinue);
     }
   }
 
@@ -93305,7 +114319,7 @@ static void selectInnerLoop(
     case SRT_Union: {
       int r1;
       r1 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
       sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
       sqlite3ReleaseTempReg(pParse, r1);
       break;
@@ -93316,21 +114330,39 @@ static void selectInnerLoop(
     ** the temporary table iParm.
     */
     case SRT_Except: {
-      sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nColumn);
+      sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);
       break;
     }
-#endif
+#endif /* SQLITE_OMIT_COMPOUND_SELECT */
 
     /* Store the result as data using a unique key.
     */
+    case SRT_Fifo:
+    case SRT_DistFifo:
     case SRT_Table:
     case SRT_EphemTab: {
-      int r1 = sqlite3GetTempReg(pParse);
+      int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
       testcase( eDest==SRT_Table );
       testcase( eDest==SRT_EphemTab );
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
-      if( pOrderBy ){
-        pushOntoSorter(pParse, pOrderBy, p, r1);
+      testcase( eDest==SRT_Fifo );
+      testcase( eDest==SRT_DistFifo );
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
+#ifndef SQLITE_OMIT_CTE
+      if( eDest==SRT_DistFifo ){
+        /* If the destination is DistFifo, then cursor (iParm+1) is open
+        ** on an ephemeral index. If the current row is already present
+        ** in the index, do not write it to the output. If not, add the
+        ** current row to the index and proceed with writing it to the
+        ** output table as well.  */
+        int addr = sqlite3VdbeCurrentAddr(v) + 4;
+        sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);
+        VdbeCoverage(v);
+        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1);
+        assert( pSort==0 );
+      }
+#endif
+      if( pSort ){
+        pushOntoSorter(pParse, pSort, p, r1+nPrefixReg,regResult,1,nPrefixReg);
       }else{
         int r2 = sqlite3GetTempReg(pParse);
         sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
@@ -93338,7 +114370,7 @@ static void selectInnerLoop(
         sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
         sqlite3ReleaseTempReg(pParse, r2);
       }
-      sqlite3ReleaseTempReg(pParse, r1);
+      sqlite3ReleaseTempRange(pParse, r1, nPrefixReg+1);
       break;
     }
 
@@ -93348,17 +114380,18 @@ static void selectInnerLoop(
     ** item into the set table with bogus data.
     */
     case SRT_Set: {
-      assert( nColumn==1 );
-      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
-      if( pOrderBy ){
+      assert( nResultCol==1 );
+      pDest->affSdst =
+                  sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst);
+      if( pSort ){
         /* At first glance you would think we could optimize out the
         ** ORDER BY in this case since the order of entries in the set
         ** does not matter.  But there might be a LIMIT clause, in which
         ** case the order does matter */
-        pushOntoSorter(pParse, pOrderBy, p, regResult);
+        pushOntoSorter(pParse, pSort, p, regResult, regResult, 1, nPrefixReg);
       }else{
         int r1 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1);
+        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult,1,r1, &pDest->affSdst, 1);
         sqlite3ExprCacheAffinityChange(pParse, regResult, 1);
         sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
         sqlite3ReleaseTempReg(pParse, r1);
@@ -93379,39 +114412,82 @@ static void selectInnerLoop(
     ** of the scan loop.
     */
     case SRT_Mem: {
-      assert( nColumn==1 );
-      if( pOrderBy ){
-        pushOntoSorter(pParse, pOrderBy, p, regResult);
+      assert( nResultCol==1 );
+      if( pSort ){
+        pushOntoSorter(pParse, pSort, p, regResult, regResult, 1, nPrefixReg);
       }else{
-        sqlite3ExprCodeMove(pParse, regResult, iParm, 1);
+        assert( regResult==iParm );
         /* The LIMIT clause will jump out of the loop for us */
       }
       break;
     }
 #endif /* #ifndef SQLITE_OMIT_SUBQUERY */
 
-    /* Send the data to the callback function or to a subroutine.  In the
-    ** case of a subroutine, the subroutine itself is responsible for
-    ** popping the data from the stack.
-    */
-    case SRT_Coroutine:
-    case SRT_Output: {
+    case SRT_Coroutine:       /* Send data to a co-routine */
+    case SRT_Output: {        /* Return the results */
       testcase( eDest==SRT_Coroutine );
       testcase( eDest==SRT_Output );
-      if( pOrderBy ){
-        int r1 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
-        pushOntoSorter(pParse, pOrderBy, p, r1);
-        sqlite3ReleaseTempReg(pParse, r1);
+      if( pSort ){
+        pushOntoSorter(pParse, pSort, p, regResult, regResult, nResultCol,
+                       nPrefixReg);
       }else if( eDest==SRT_Coroutine ){
-        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
       }else{
-        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn);
-        sqlite3ExprCacheAffinityChange(pParse, regResult, nColumn);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
+        sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
       }
       break;
     }
 
+#ifndef SQLITE_OMIT_CTE
+    /* Write the results into a priority queue that is order according to
+    ** pDest->pOrderBy (in pSO).  pDest->iSDParm (in iParm) is the cursor for an
+    ** index with pSO->nExpr+2 columns.  Build a key using pSO for the first
+    ** pSO->nExpr columns, then make sure all keys are unique by adding a
+    ** final OP_Sequence column.  The last column is the record as a blob.
+    */
+    case SRT_DistQueue:
+    case SRT_Queue: {
+      int nKey;
+      int r1, r2, r3;
+      int addrTest = 0;
+      ExprList *pSO;
+      pSO = pDest->pOrderBy;
+      assert( pSO );
+      nKey = pSO->nExpr;
+      r1 = sqlite3GetTempReg(pParse);
+      r2 = sqlite3GetTempRange(pParse, nKey+2);
+      r3 = r2+nKey+1;
+      if( eDest==SRT_DistQueue ){
+        /* If the destination is DistQueue, then cursor (iParm+1) is open
+        ** on a second ephemeral index that holds all values every previously
+        ** added to the queue. */
+        addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0, 
+                                        regResult, nResultCol);
+        VdbeCoverage(v);
+      }
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);
+      if( eDest==SRT_DistQueue ){
+        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);
+        sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+      }
+      for(i=0; i<nKey; i++){
+        sqlite3VdbeAddOp2(v, OP_SCopy,
+                          regResult + pSO->a[i].u.x.iOrderByCol - 1,
+                          r2+i);
+      }
+      sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
+      if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);
+      sqlite3ReleaseTempReg(pParse, r1);
+      sqlite3ReleaseTempRange(pParse, r2, nKey+2);
+      break;
+    }
+#endif /* SQLITE_OMIT_CTE */
+
+
+
 #if !defined(SQLITE_OMIT_TRIGGER)
     /* Discard the results.  This is used for SELECT statements inside
     ** the body of a TRIGGER.  The purpose of such selects is to call
@@ -93429,12 +114505,65 @@ static void selectInnerLoop(
   ** there is a sorter, in which case the sorter has already limited
   ** the output for us.
   */
-  if( pOrderBy==0 && p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1);
+  if( pSort==0 && p->iLimit ){
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
+  }
+}
+
+/*
+** Allocate a KeyInfo object sufficient for an index of N key columns and
+** X extra columns.
+*/
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
+  int nExtra = (N+X)*(sizeof(CollSeq*)+1);
+  KeyInfo *p = sqlite3DbMallocRaw(db, sizeof(KeyInfo) + nExtra);
+  if( p ){
+    p->aSortOrder = (u8*)&p->aColl[N+X];
+    p->nField = (u16)N;
+    p->nXField = (u16)X;
+    p->enc = ENC(db);
+    p->db = db;
+    p->nRef = 1;
+    memset(&p[1], 0, nExtra);
+  }else{
+    sqlite3OomFault(db);
+  }
+  return p;
+}
+
+/*
+** Deallocate a KeyInfo object
+*/
+SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo *p){
+  if( p ){
+    assert( p->nRef>0 );
+    p->nRef--;
+    if( p->nRef==0 ) sqlite3DbFree(p->db, p);
   }
 }
 
 /*
+** Make a new pointer to a KeyInfo object
+*/
+SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo *p){
+  if( p ){
+    assert( p->nRef>0 );
+    p->nRef++;
+  }
+  return p;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** Return TRUE if a KeyInfo object can be change.  The KeyInfo object
+** can only be changed if this is just a single reference to the object.
+**
+** This routine is used only inside of assert() statements.
+*/
+SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; }
+#endif /* SQLITE_DEBUG */
+
+/*
 ** Given an expression list, generate a KeyInfo structure that records
 ** the collating sequence for each expression in that expression list.
 **
@@ -93444,39 +114573,37 @@ static void selectInnerLoop(
 ** then the KeyInfo structure is appropriate for initializing a virtual
 ** index to implement a DISTINCT test.
 **
-** Space to hold the KeyInfo structure is obtain from malloc.  The calling
+** Space to hold the KeyInfo structure is obtained from malloc.  The calling
 ** function is responsible for seeing that this structure is eventually
-** freed.  Add the KeyInfo structure to the P4 field of an opcode using
-** P4_KEYINFO_HANDOFF is the usual way of dealing with this.
+** freed.
 */
-static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
-  sqlite3 *db = pParse->db;
+static KeyInfo *keyInfoFromExprList(
+  Parse *pParse,       /* Parsing context */
+  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
+  int iStart,          /* Begin with this column of pList */
+  int nExtra           /* Add this many extra columns to the end */
+){
   int nExpr;
   KeyInfo *pInfo;
   struct ExprList_item *pItem;
+  sqlite3 *db = pParse->db;
   int i;
 
   nExpr = pList->nExpr;
-  pInfo = sqlite3DbMallocZero(db, sizeof(*pInfo) + nExpr*(sizeof(CollSeq*)+1) );
+  pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
   if( pInfo ){
-    pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr];
-    pInfo->nField = (u16)nExpr;
-    pInfo->enc = ENC(db);
-    pInfo->db = db;
-    for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){
+    assert( sqlite3KeyInfoIsWriteable(pInfo) );
+    for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
       CollSeq *pColl;
       pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      if( !pColl ){
-        pColl = db->pDfltColl;
-      }
-      pInfo->aColl[i] = pColl;
-      pInfo->aSortOrder[i] = pItem->sortOrder;
+      if( !pColl ) pColl = db->pDfltColl;
+      pInfo->aColl[i-iStart] = pColl;
+      pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
     }
   }
   return pInfo;
 }
 
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
 /*
 ** Name of the connection operator, used for error messages.
 */
@@ -93490,7 +114617,6 @@ static const char *selectOpName(int id){
   }
   return z;
 }
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
 
 #ifndef SQLITE_OMIT_EXPLAIN
 /*
@@ -93572,51 +114698,72 @@ static void explainComposite(
 static void generateSortTail(
   Parse *pParse,    /* Parsing context */
   Select *p,        /* The SELECT statement */
-  Vdbe *v,          /* Generate code into this VDBE */
+  SortCtx *pSort,   /* Information on the ORDER BY clause */
   int nColumn,      /* Number of columns of data */
   SelectDest *pDest /* Write the sorted results here */
 ){
-  int addrBreak = sqlite3VdbeMakeLabel(v);     /* Jump here to exit loop */
+  Vdbe *v = pParse->pVdbe;                     /* The prepared statement */
+  int addrBreak = pSort->labelDone;            /* Jump here to exit loop */
   int addrContinue = sqlite3VdbeMakeLabel(v);  /* Jump here for next cycle */
   int addr;
+  int addrOnce = 0;
   int iTab;
-  int pseudoTab = 0;
-  ExprList *pOrderBy = p->pOrderBy;
-
+  ExprList *pOrderBy = pSort->pOrderBy;
   int eDest = pDest->eDest;
-  int iParm = pDest->iParm;
-
+  int iParm = pDest->iSDParm;
   int regRow;
   int regRowid;
+  int nKey;
+  int iSortTab;                   /* Sorter cursor to read from */
+  int nSortData;                  /* Trailing values to read from sorter */
+  int i;
+  int bSeq;                       /* True if sorter record includes seq. no. */
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+  struct ExprList_item *aOutEx = p->pEList->a;
+#endif
 
-  iTab = pOrderBy->iECursor;
-  regRow = sqlite3GetTempReg(pParse);
+  assert( addrBreak<0 );
+  if( pSort->labelBkOut ){
+    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
+    sqlite3VdbeGoto(v, addrBreak);
+    sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
+  }
+  iTab = pSort->iECursor;
   if( eDest==SRT_Output || eDest==SRT_Coroutine ){
-    pseudoTab = pParse->nTab++;
-    sqlite3VdbeAddOp3(v, OP_OpenPseudo, pseudoTab, regRow, nColumn);
     regRowid = 0;
+    regRow = pDest->iSdst;
+    nSortData = nColumn;
   }else{
     regRowid = sqlite3GetTempReg(pParse);
+    regRow = sqlite3GetTempReg(pParse);
+    nSortData = 1;
   }
-  if( p->selFlags & SF_UseSorter ){
+  nKey = pOrderBy->nExpr - pSort->nOBSat;
+  if( pSort->sortFlags & SORTFLAG_UseSorter ){
     int regSortOut = ++pParse->nMem;
-    int ptab2 = pParse->nTab++;
-    sqlite3VdbeAddOp3(v, OP_OpenPseudo, ptab2, regSortOut, pOrderBy->nExpr+2);
+    iSortTab = pParse->nTab++;
+    if( pSort->labelBkOut ){
+      addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+    }
+    sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, nKey+1+nSortData);
+    if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
     addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
-    codeOffset(v, p, addrContinue);
-    sqlite3VdbeAddOp2(v, OP_SorterData, iTab, regSortOut);
-    sqlite3VdbeAddOp3(v, OP_Column, ptab2, pOrderBy->nExpr+1, regRow);
-    sqlite3VdbeChangeP5(v, OPFLAG_CLEARCACHE);
+    VdbeCoverage(v);
+    codeOffset(v, p->iOffset, addrContinue);
+    sqlite3VdbeAddOp3(v, OP_SorterData, iTab, regSortOut, iSortTab);
+    bSeq = 0;
   }else{
-    addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak);
-    codeOffset(v, p, addrContinue);
-    sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr+1, regRow);
+    addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);
+    codeOffset(v, p->iOffset, addrContinue);
+    iSortTab = iTab;
+    bSeq = 1;
+  }
+  for(i=0; i<nSortData; i++){
+    sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq+i, regRow+i);
+    VdbeComment((v, "%s", aOutEx[i].zName ? aOutEx[i].zName : aOutEx[i].zSpan));
   }
   switch( eDest ){
-    case SRT_Table:
     case SRT_EphemTab: {
-      testcase( eDest==SRT_Table );
-      testcase( eDest==SRT_EphemTab );
       sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
       sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
       sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
@@ -93625,7 +114772,8 @@ static void generateSortTail(
 #ifndef SQLITE_OMIT_SUBQUERY
     case SRT_Set: {
       assert( nColumn==1 );
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid, &p->affinity, 1);
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid,
+                        &pDest->affSdst, 1);
       sqlite3ExprCacheAffinityChange(pParse, regRow, 1);
       sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
       break;
@@ -93638,47 +114786,41 @@ static void generateSortTail(
     }
 #endif
     default: {
-      int i;
       assert( eDest==SRT_Output || eDest==SRT_Coroutine ); 
       testcase( eDest==SRT_Output );
       testcase( eDest==SRT_Coroutine );
-      for(i=0; i<nColumn; i++){
-        assert( regRow!=pDest->iMem+i );
-        sqlite3VdbeAddOp3(v, OP_Column, pseudoTab, i, pDest->iMem+i);
-        if( i==0 ){
-          sqlite3VdbeChangeP5(v, OPFLAG_CLEARCACHE);
-        }
-      }
       if( eDest==SRT_Output ){
-        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn);
-        sqlite3ExprCacheAffinityChange(pParse, pDest->iMem, nColumn);
+        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
+        sqlite3ExprCacheAffinityChange(pParse, pDest->iSdst, nColumn);
       }else{
-        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
       }
       break;
     }
   }
-  sqlite3ReleaseTempReg(pParse, regRow);
-  sqlite3ReleaseTempReg(pParse, regRowid);
-
+  if( regRowid ){
+    sqlite3ReleaseTempReg(pParse, regRow);
+    sqlite3ReleaseTempReg(pParse, regRowid);
+  }
   /* The bottom of the loop
   */
   sqlite3VdbeResolveLabel(v, addrContinue);
-  if( p->selFlags & SF_UseSorter ){
-    sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr);
+  if( pSort->sortFlags & SORTFLAG_UseSorter ){
+    sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);
   }else{
-    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr);
+    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);
   }
+  if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);
   sqlite3VdbeResolveLabel(v, addrBreak);
-  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
-    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
-  }
 }
 
 /*
 ** Return a pointer to a string containing the 'declaration type' of the
 ** expression pExpr. The string may be treated as static by the caller.
 **
+** Also try to estimate the size of the returned value and return that
+** result in *pEstWidth.
+**
 ** The declaration type is the exact datatype definition extracted from the
 ** original CREATE TABLE statement if the expression is a column. The
 ** declaration type for a ROWID field is INTEGER. Exactly when an expression
@@ -93692,21 +114834,36 @@ static void generateSortTail(
 **   SELECT abc FROM (SELECT col AS abc FROM tbl);
 ** 
 ** The declaration type for any expression other than a column is NULL.
+**
+** This routine has either 3 or 6 parameters depending on whether or not
+** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.
 */
-static const char *columnType(
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,C,D,E,F)
+#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
+# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F)
+#endif
+static const char *columnTypeImpl(
   NameContext *pNC, 
   Expr *pExpr,
-  const char **pzOriginDb,
-  const char **pzOriginTab,
-  const char **pzOriginCol
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+  const char **pzOrigDb,
+  const char **pzOrigTab,
+  const char **pzOrigCol,
+#endif
+  u8 *pEstWidth
 ){
   char const *zType = 0;
-  char const *zOriginDb = 0;
-  char const *zOriginTab = 0;
-  char const *zOriginCol = 0;
   int j;
-  if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0;
+  u8 estWidth = 1;
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
+  char const *zOrigDb = 0;
+  char const *zOrigTab = 0;
+  char const *zOrigCol = 0;
+#endif
 
+  assert( pExpr!=0 );
+  assert( pNC->pSrcList!=0 );
   switch( pExpr->op ){
     case TK_AGG_COLUMN:
     case TK_COLUMN: {
@@ -93761,31 +114918,44 @@ static const char *columnType(
           /* If iCol is less than zero, then the expression requests the
           ** rowid of the sub-select or view. This expression is legal (see 
           ** test case misc2.2.2) - it always evaluates to NULL.
+          **
+          ** The ALWAYS() is because iCol>=pS->pEList->nExpr will have been
+          ** caught already by name resolution.
           */
           NameContext sNC;
           Expr *p = pS->pEList->a[iCol].pExpr;
           sNC.pSrcList = pS->pSrc;
           sNC.pNext = pNC;
           sNC.pParse = pNC->pParse;
-          zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
+          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 
         }
-      }else if( ALWAYS(pTab->pSchema) ){
+      }else if( pTab->pSchema ){
         /* A real table */
         assert( !pS );
         if( iCol<0 ) iCol = pTab->iPKey;
         assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
+#ifdef SQLITE_ENABLE_COLUMN_METADATA
         if( iCol<0 ){
           zType = "INTEGER";
-          zOriginCol = "rowid";
+          zOrigCol = "rowid";
         }else{
-          zType = pTab->aCol[iCol].zType;
-          zOriginCol = pTab->aCol[iCol].zName;
+          zOrigCol = pTab->aCol[iCol].zName;
+          zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
+          estWidth = pTab->aCol[iCol].szEst;
         }
-        zOriginTab = pTab->zName;
+        zOrigTab = pTab->zName;
         if( pNC->pParse ){
           int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
-          zOriginDb = pNC->pParse->db->aDb[iDb].zName;
+          zOrigDb = pNC->pParse->db->aDb[iDb].zName;
+        }
+#else
+        if( iCol<0 ){
+          zType = "INTEGER";
+        }else{
+          zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
+          estWidth = pTab->aCol[iCol].szEst;
         }
+#endif
       }
       break;
     }
@@ -93802,18 +114972,21 @@ static const char *columnType(
       sNC.pSrcList = pS->pSrc;
       sNC.pNext = pNC;
       sNC.pParse = pNC->pParse;
-      zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
+      zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, &estWidth); 
       break;
     }
 #endif
   }
-  
-  if( pzOriginDb ){
-    assert( pzOriginTab && pzOriginCol );
-    *pzOriginDb = zOriginDb;
-    *pzOriginTab = zOriginTab;
-    *pzOriginCol = zOriginCol;
+
+#ifdef SQLITE_ENABLE_COLUMN_METADATA  
+  if( pzOrigDb ){
+    assert( pzOrigTab && pzOrigCol );
+    *pzOrigDb = zOrigDb;
+    *pzOrigTab = zOrigTab;
+    *pzOrigCol = zOrigCol;
   }
+#endif
+  if( pEstWidth ) *pEstWidth = estWidth;
   return zType;
 }
 
@@ -93839,7 +115012,7 @@ static void generateColumnTypes(
     const char *zOrigDb = 0;
     const char *zOrigTab = 0;
     const char *zOrigCol = 0;
-    zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
+    zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, 0);
 
     /* The vdbe must make its own copy of the column-type and other 
     ** column specific strings, in case the schema is reset before this
@@ -93849,11 +115022,11 @@ static void generateColumnTypes(
     sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);
     sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);
 #else
-    zType = columnType(&sNC, p, 0, 0, 0);
+    zType = columnType(&sNC, p, 0, 0, 0, 0);
 #endif
     sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
   }
-#endif /* SQLITE_OMIT_DECLTYPE */
+#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
 }
 
 /*
@@ -93878,7 +115051,9 @@ static void generateColumnNames(
   }
 #endif
 
-  if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return;
+  if( pParse->colNamesSet || db->mallocFailed ) return;
+  assert( v!=0 );
+  assert( pTabList!=0 );
   pParse->colNamesSet = 1;
   fullNames = (db->flags & SQLITE_FullColNames)!=0;
   shortNames = (db->flags & SQLITE_ShortColNames)!=0;
@@ -93890,7 +115065,7 @@ static void generateColumnNames(
     if( pEList->a[i].zName ){
       char *zName = pEList->a[i].zName;
       sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
-    }else if( (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN) && pTabList ){
+    }else if( p->op==TK_COLUMN || p->op==TK_AGG_COLUMN ){
       Table *pTab;
       char *zCol;
       int iCol = p->iColumn;
@@ -93917,15 +115092,16 @@ static void generateColumnNames(
         sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
       }
     }else{
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, 
-          sqlite3DbStrDup(db, pEList->a[i].zSpan), SQLITE_DYNAMIC);
+      const char *z = pEList->a[i].zSpan;
+      z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);
+      sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
     }
   }
   generateColumnTypes(pParse, pTabList, pEList);
 }
 
 /*
-** Given a an expression list (which is really the list of expressions
+** Given an expression list (which is really the list of expressions
 ** that form the result set of a SELECT statement) compute appropriate
 ** column names for a table that would hold the expression list.
 **
@@ -93937,33 +115113,41 @@ static void generateColumnNames(
 ** Return SQLITE_OK on success.  If a memory allocation error occurs,
 ** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.
 */
-static int selectColumnsFromExprList(
+SQLITE_PRIVATE int sqlite3ColumnsFromExprList(
   Parse *pParse,          /* Parsing context */
   ExprList *pEList,       /* Expr list from which to derive column names */
-  int *pnCol,             /* Write the number of columns here */
+  i16 *pnCol,             /* Write the number of columns here */
   Column **paCol          /* Write the new column list here */
 ){
   sqlite3 *db = pParse->db;   /* Database connection */
   int i, j;                   /* Loop counters */
-  int cnt;                    /* Index added to make the name unique */
+  u32 cnt;                    /* Index added to make the name unique */
   Column *aCol, *pCol;        /* For looping over result columns */
   int nCol;                   /* Number of columns in the result set */
   Expr *p;                    /* Expression for a single result column */
   char *zName;                /* Column name */
   int nName;                  /* Size of name in zName[] */
+  Hash ht;                    /* Hash table of column names */
+
+  sqlite3HashInit(&ht);
+  if( pEList ){
+    nCol = pEList->nExpr;
+    aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
+    testcase( aCol==0 );
+  }else{
+    nCol = 0;
+    aCol = 0;
+  }
+  assert( nCol==(i16)nCol );
+  *pnCol = nCol;
+  *paCol = aCol;
 
-  *pnCol = nCol = pEList->nExpr;
-  aCol = *paCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
-  if( aCol==0 ) return SQLITE_NOMEM;
-  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
+  for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
     /* Get an appropriate name for the column
     */
-    p = pEList->a[i].pExpr;
-    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)
-               || p->pRight->u.zToken==0 || p->pRight->u.zToken[0]!=0 );
+    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
     if( (zName = pEList->a[i].zName)!=0 ){
       /* If the column contains an "AS <name>" phrase, use <name> as the name */
-      zName = sqlite3DbStrDup(db, zName);
     }else{
       Expr *pColExpr = p;  /* The expression that is the result column name */
       Table *pTab;         /* Table associated with this expression */
@@ -93976,38 +115160,37 @@ static int selectColumnsFromExprList(
         int iCol = pColExpr->iColumn;
         pTab = pColExpr->pTab;
         if( iCol<0 ) iCol = pTab->iPKey;
-        zName = sqlite3MPrintf(db, "%s",
-                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
+        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
       }else if( pColExpr->op==TK_ID ){
         assert( !ExprHasProperty(pColExpr, EP_IntValue) );
-        zName = sqlite3MPrintf(db, "%s", pColExpr->u.zToken);
+        zName = pColExpr->u.zToken;
       }else{
         /* Use the original text of the column expression as its name */
-        zName = sqlite3MPrintf(db, "%s", pEList->a[i].zSpan);
+        zName = pEList->a[i].zSpan;
       }
     }
-    if( db->mallocFailed ){
-      sqlite3DbFree(db, zName);
-      break;
-    }
+    zName = sqlite3MPrintf(db, "%s", zName);
 
     /* Make sure the column name is unique.  If the name is not unique,
-    ** append a integer to the name so that it becomes unique.
+    ** append an integer to the name so that it becomes unique.
     */
-    nName = sqlite3Strlen30(zName);
-    for(j=cnt=0; j<i; j++){
-      if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
-        char *zNewName;
-        zName[nName] = 0;
-        zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt);
-        sqlite3DbFree(db, zName);
-        zName = zNewName;
-        j = -1;
-        if( zName==0 ) break;
+    cnt = 0;
+    while( zName && sqlite3HashFind(&ht, zName)!=0 ){
+      nName = sqlite3Strlen30(zName);
+      if( nName>0 ){
+        for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
+        if( zName[j]==':' ) nName = j;
       }
+      zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
+      if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
     }
     pCol->zName = zName;
+    sqlite3ColumnPropertiesFromName(0, pCol);
+    if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
+      sqlite3OomFault(db);
+    }
   }
+  sqlite3HashClear(&ht);
   if( db->mallocFailed ){
     for(j=0; j<i; j++){
       sqlite3DbFree(db, aCol[j].zName);
@@ -94015,7 +115198,7 @@ static int selectColumnsFromExprList(
     sqlite3DbFree(db, aCol);
     *paCol = 0;
     *pnCol = 0;
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   return SQLITE_OK;
 }
@@ -94031,10 +115214,9 @@ static int selectColumnsFromExprList(
 ** This routine requires that all identifiers in the SELECT
 ** statement be resolved.
 */
-static void selectAddColumnTypeAndCollation(
+SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(
   Parse *pParse,        /* Parsing contexts */
-  int nCol,             /* Number of columns */
-  Column *aCol,         /* List of columns */
+  Table *pTab,          /* Add column type information to this table */
   Select *pSelect       /* SELECT used to determine types and collations */
 ){
   sqlite3 *db = pParse->db;
@@ -94044,24 +115226,37 @@ static void selectAddColumnTypeAndCollation(
   int i;
   Expr *p;
   struct ExprList_item *a;
+  u64 szAll = 0;
 
   assert( pSelect!=0 );
   assert( (pSelect->selFlags & SF_Resolved)!=0 );
-  assert( nCol==pSelect->pEList->nExpr || db->mallocFailed );
+  assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );
   if( db->mallocFailed ) return;
   memset(&sNC, 0, sizeof(sNC));
   sNC.pSrcList = pSelect->pSrc;
   a = pSelect->pEList->a;
-  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
+  for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
+    const char *zType;
+    int n, m;
     p = a[i].pExpr;
-    pCol->zType = sqlite3DbStrDup(db, columnType(&sNC, p, 0, 0, 0));
+    zType = columnType(&sNC, p, 0, 0, 0, &pCol->szEst);
+    szAll += pCol->szEst;
     pCol->affinity = sqlite3ExprAffinity(p);
-    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_NONE;
+    if( zType && (m = sqlite3Strlen30(zType))>0 ){
+      n = sqlite3Strlen30(pCol->zName);
+      pCol->zName = sqlite3DbReallocOrFree(db, pCol->zName, n+m+2);
+      if( pCol->zName ){
+        memcpy(&pCol->zName[n+1], zType, m+1);
+        pCol->colFlags |= COLFLAG_HASTYPE;
+      }
+    }
+    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB;
     pColl = sqlite3ExprCollSeq(pParse, p);
-    if( pColl ){
+    if( pColl && pCol->zColl==0 ){
       pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
     }
   }
+  pTab->szTabRow = sqlite3LogEst(szAll*4);
 }
 
 /*
@@ -94086,12 +115281,12 @@ SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
   }
   /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
   ** is disabled */
-  assert( db->lookaside.bEnabled==0 );
+  assert( db->lookaside.bDisable );
   pTab->nRef = 1;
   pTab->zName = 0;
-  pTab->nRowEst = 1000000;
-  selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
-  selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSelect);
+  pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
+  sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
+  sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSelect);
   pTab->iPKey = -1;
   if( db->mallocFailed ){
     sqlite3DeleteTable(db, pTab);
@@ -94104,18 +115299,20 @@ SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
 ** Get a VDBE for the given parser context.  Create a new one if necessary.
 ** If an error occurs, return NULL and leave a message in pParse.
 */
-SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
-  Vdbe *v = pParse->pVdbe;
-  if( v==0 ){
-    v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db);
-#ifndef SQLITE_OMIT_TRACE
-    if( v ){
-      sqlite3VdbeAddOp0(v, OP_Trace);
-    }
-#endif
+static SQLITE_NOINLINE Vdbe *allocVdbe(Parse *pParse){
+  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(pParse);
+  if( v ) sqlite3VdbeAddOp0(v, OP_Init);
+  if( pParse->pToplevel==0
+   && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
+  ){
+    pParse->okConstFactor = 1;
   }
   return v;
 }
+SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
+  Vdbe *v = pParse->pVdbe;
+  return v ? v : allocVdbe(pParse);
+}
 
 
 /*
@@ -94129,8 +115326,13 @@ SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
 **
 ** This routine changes the values of iLimit and iOffset only if
 ** a limit or offset is defined by pLimit and pOffset.  iLimit and
-** iOffset should have been preset to appropriate default values
-** (usually but not always -1) prior to calling this routine.
+** iOffset should have been preset to appropriate default values (zero)
+** prior to calling this routine.
+**
+** The iOffset register (if it exists) is initialized to the value
+** of the OFFSET.  The iLimit register is initialized to LIMIT.  Register
+** iOffset+1 is initialized to LIMIT+OFFSET.
+**
 ** Only if pLimit!=0 or pOffset!=0 do the limit registers get
 ** redefined.  The UNION ALL operator uses this property to force
 ** the reuse of the same limit and offset registers across multiple
@@ -94140,12 +115342,12 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
   Vdbe *v = 0;
   int iLimit = 0;
   int iOffset;
-  int addr1, n;
+  int n;
   if( p->iLimit ) return;
 
   /* 
   ** "LIMIT -1" always shows all rows.  There is some
-  ** contraversy about what the correct behavior should be.
+  ** controversy about what the correct behavior should be.
   ** The current implementation interprets "LIMIT 0" to mean
   ** no rows.
   */
@@ -94154,35 +115356,30 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
   if( p->pLimit ){
     p->iLimit = iLimit = ++pParse->nMem;
     v = sqlite3GetVdbe(pParse);
-    if( NEVER(v==0) ) return;  /* VDBE should have already been allocated */
+    assert( v!=0 );
     if( sqlite3ExprIsInteger(p->pLimit, &n) ){
       sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
       VdbeComment((v, "LIMIT counter"));
       if( n==0 ){
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
-      }else{
-        if( p->nSelectRow > (double)n ) p->nSelectRow = (double)n;
+        sqlite3VdbeGoto(v, iBreak);
+      }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
+        p->nSelectRow = sqlite3LogEst((u64)n);
+        p->selFlags |= SF_FixedLimit;
       }
     }else{
       sqlite3ExprCode(pParse, p->pLimit, iLimit);
-      sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit);
+      sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
       VdbeComment((v, "LIMIT counter"));
-      sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak);
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
     }
     if( p->pOffset ){
       p->iOffset = iOffset = ++pParse->nMem;
       pParse->nMem++;   /* Allocate an extra register for limit+offset */
       sqlite3ExprCode(pParse, p->pOffset, iOffset);
-      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset);
+      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
       VdbeComment((v, "OFFSET counter"));
-      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset);
-      sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset);
-      sqlite3VdbeJumpHere(v, addr1);
-      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
+      sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
       VdbeComment((v, "LIMIT+OFFSET"));
-      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit);
-      sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1);
-      sqlite3VdbeJumpHere(v, addr1);
     }
   }
 }
@@ -94204,22 +115401,271 @@ static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
     pRet = 0;
   }
   assert( iCol>=0 );
-  if( pRet==0 && iCol<p->pEList->nExpr ){
+  /* iCol must be less than p->pEList->nExpr.  Otherwise an error would
+  ** have been thrown during name resolution and we would not have gotten
+  ** this far */
+  if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){
     pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
   }
   return pRet;
 }
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
 
-/* Forward reference */
+/*
+** The select statement passed as the second parameter is a compound SELECT
+** with an ORDER BY clause. This function allocates and returns a KeyInfo
+** structure suitable for implementing the ORDER BY.
+**
+** Space to hold the KeyInfo structure is obtained from malloc. The calling
+** function is responsible for ensuring that this structure is eventually
+** freed.
+*/
+static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){
+  ExprList *pOrderBy = p->pOrderBy;
+  int nOrderBy = p->pOrderBy->nExpr;
+  sqlite3 *db = pParse->db;
+  KeyInfo *pRet = sqlite3KeyInfoAlloc(db, nOrderBy+nExtra, 1);
+  if( pRet ){
+    int i;
+    for(i=0; i<nOrderBy; i++){
+      struct ExprList_item *pItem = &pOrderBy->a[i];
+      Expr *pTerm = pItem->pExpr;
+      CollSeq *pColl;
+
+      if( pTerm->flags & EP_Collate ){
+        pColl = sqlite3ExprCollSeq(pParse, pTerm);
+      }else{
+        pColl = multiSelectCollSeq(pParse, p, pItem->u.x.iOrderByCol-1);
+        if( pColl==0 ) pColl = db->pDfltColl;
+        pOrderBy->a[i].pExpr =
+          sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);
+      }
+      assert( sqlite3KeyInfoIsWriteable(pRet) );
+      pRet->aColl[i] = pColl;
+      pRet->aSortOrder[i] = pOrderBy->a[i].sortOrder;
+    }
+  }
+
+  return pRet;
+}
+
+#ifndef SQLITE_OMIT_CTE
+/*
+** This routine generates VDBE code to compute the content of a WITH RECURSIVE
+** query of the form:
+**
+**   <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)
+**                         \___________/             \_______________/
+**                           p->pPrior                      p
+**
+**
+** There is exactly one reference to the recursive-table in the FROM clause
+** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
+**
+** The setup-query runs once to generate an initial set of rows that go
+** into a Queue table.  Rows are extracted from the Queue table one by
+** one.  Each row extracted from Queue is output to pDest.  Then the single
+** extracted row (now in the iCurrent table) becomes the content of the
+** recursive-table for a recursive-query run.  The output of the recursive-query
+** is added back into the Queue table.  Then another row is extracted from Queue
+** and the iteration continues until the Queue table is empty.
+**
+** If the compound query operator is UNION then no duplicate rows are ever
+** inserted into the Queue table.  The iDistinct table keeps a copy of all rows
+** that have ever been inserted into Queue and causes duplicates to be
+** discarded.  If the operator is UNION ALL, then duplicates are allowed.
+** 
+** If the query has an ORDER BY, then entries in the Queue table are kept in
+** ORDER BY order and the first entry is extracted for each cycle.  Without
+** an ORDER BY, the Queue table is just a FIFO.
+**
+** If a LIMIT clause is provided, then the iteration stops after LIMIT rows
+** have been output to pDest.  A LIMIT of zero means to output no rows and a
+** negative LIMIT means to output all rows.  If there is also an OFFSET clause
+** with a positive value, then the first OFFSET outputs are discarded rather
+** than being sent to pDest.  The LIMIT count does not begin until after OFFSET
+** rows have been skipped.
+*/
+static void generateWithRecursiveQuery(
+  Parse *pParse,        /* Parsing context */
+  Select *p,            /* The recursive SELECT to be coded */
+  SelectDest *pDest     /* What to do with query results */
+){
+  SrcList *pSrc = p->pSrc;      /* The FROM clause of the recursive query */
+  int nCol = p->pEList->nExpr;  /* Number of columns in the recursive table */
+  Vdbe *v = pParse->pVdbe;      /* The prepared statement under construction */
+  Select *pSetup = p->pPrior;   /* The setup query */
+  int addrTop;                  /* Top of the loop */
+  int addrCont, addrBreak;      /* CONTINUE and BREAK addresses */
+  int iCurrent = 0;             /* The Current table */
+  int regCurrent;               /* Register holding Current table */
+  int iQueue;                   /* The Queue table */
+  int iDistinct = 0;            /* To ensure unique results if UNION */
+  int eDest = SRT_Fifo;         /* How to write to Queue */
+  SelectDest destQueue;         /* SelectDest targetting the Queue table */
+  int i;                        /* Loop counter */
+  int rc;                       /* Result code */
+  ExprList *pOrderBy;           /* The ORDER BY clause */
+  Expr *pLimit, *pOffset;       /* Saved LIMIT and OFFSET */
+  int regLimit, regOffset;      /* Registers used by LIMIT and OFFSET */
+
+  /* Obtain authorization to do a recursive query */
+  if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;
+
+  /* Process the LIMIT and OFFSET clauses, if they exist */
+  addrBreak = sqlite3VdbeMakeLabel(v);
+  computeLimitRegisters(pParse, p, addrBreak);
+  pLimit = p->pLimit;
+  pOffset = p->pOffset;
+  regLimit = p->iLimit;
+  regOffset = p->iOffset;
+  p->pLimit = p->pOffset = 0;
+  p->iLimit = p->iOffset = 0;
+  pOrderBy = p->pOrderBy;
+
+  /* Locate the cursor number of the Current table */
+  for(i=0; ALWAYS(i<pSrc->nSrc); i++){
+    if( pSrc->a[i].fg.isRecursive ){
+      iCurrent = pSrc->a[i].iCursor;
+      break;
+    }
+  }
+
+  /* Allocate cursors numbers for Queue and Distinct.  The cursor number for
+  ** the Distinct table must be exactly one greater than Queue in order
+  ** for the SRT_DistFifo and SRT_DistQueue destinations to work. */
+  iQueue = pParse->nTab++;
+  if( p->op==TK_UNION ){
+    eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;
+    iDistinct = pParse->nTab++;
+  }else{
+    eDest = pOrderBy ? SRT_Queue : SRT_Fifo;
+  }
+  sqlite3SelectDestInit(&destQueue, eDest, iQueue);
+
+  /* Allocate cursors for Current, Queue, and Distinct. */
+  regCurrent = ++pParse->nMem;
+  sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);
+  if( pOrderBy ){
+    KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);
+    sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,
+                      (char*)pKeyInfo, P4_KEYINFO);
+    destQueue.pOrderBy = pOrderBy;
+  }else{
+    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);
+  }
+  VdbeComment((v, "Queue table"));
+  if( iDistinct ){
+    p->addrOpenEphm[0] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iDistinct, 0);
+    p->selFlags |= SF_UsesEphemeral;
+  }
+
+  /* Detach the ORDER BY clause from the compound SELECT */
+  p->pOrderBy = 0;
+
+  /* Store the results of the setup-query in Queue. */
+  pSetup->pNext = 0;
+  rc = sqlite3Select(pParse, pSetup, &destQueue);
+  pSetup->pNext = p;
+  if( rc ) goto end_of_recursive_query;
+
+  /* Find the next row in the Queue and output that row */
+  addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak); VdbeCoverage(v);
+
+  /* Transfer the next row in Queue over to Current */
+  sqlite3VdbeAddOp1(v, OP_NullRow, iCurrent); /* To reset column cache */
+  if( pOrderBy ){
+    sqlite3VdbeAddOp3(v, OP_Column, iQueue, pOrderBy->nExpr+1, regCurrent);
+  }else{
+    sqlite3VdbeAddOp2(v, OP_RowData, iQueue, regCurrent);
+  }
+  sqlite3VdbeAddOp1(v, OP_Delete, iQueue);
+
+  /* Output the single row in Current */
+  addrCont = sqlite3VdbeMakeLabel(v);
+  codeOffset(v, regOffset, addrCont);
+  selectInnerLoop(pParse, p, p->pEList, iCurrent,
+      0, 0, pDest, addrCont, addrBreak);
+  if( regLimit ){
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
+    VdbeCoverage(v);
+  }
+  sqlite3VdbeResolveLabel(v, addrCont);
+
+  /* Execute the recursive SELECT taking the single row in Current as
+  ** the value for the recursive-table. Store the results in the Queue.
+  */
+  if( p->selFlags & SF_Aggregate ){
+    sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
+  }else{
+    p->pPrior = 0;
+    sqlite3Select(pParse, p, &destQueue);
+    assert( p->pPrior==0 );
+    p->pPrior = pSetup;
+  }
+
+  /* Keep running the loop until the Queue is empty */
+  sqlite3VdbeGoto(v, addrTop);
+  sqlite3VdbeResolveLabel(v, addrBreak);
+
+end_of_recursive_query:
+  sqlite3ExprListDelete(pParse->db, p->pOrderBy);
+  p->pOrderBy = pOrderBy;
+  p->pLimit = pLimit;
+  p->pOffset = pOffset;
+  return;
+}
+#endif /* SQLITE_OMIT_CTE */
+
+/* Forward references */
 static int multiSelectOrderBy(
   Parse *pParse,        /* Parsing context */
   Select *p,            /* The right-most of SELECTs to be coded */
   SelectDest *pDest     /* What to do with query results */
 );
 
+/*
+** Handle the special case of a compound-select that originates from a
+** VALUES clause.  By handling this as a special case, we avoid deep
+** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT
+** on a VALUES clause.
+**
+** Because the Select object originates from a VALUES clause:
+**   (1) It has no LIMIT or OFFSET
+**   (2) All terms are UNION ALL
+**   (3) There is no ORDER BY clause
+*/
+static int multiSelectValues(
+  Parse *pParse,        /* Parsing context */
+  Select *p,            /* The right-most of SELECTs to be coded */
+  SelectDest *pDest     /* What to do with query results */
+){
+  Select *pPrior;
+  int nRow = 1;
+  int rc = 0;
+  assert( p->selFlags & SF_MultiValue );
+  do{
+    assert( p->selFlags & SF_Values );
+    assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
+    assert( p->pLimit==0 );
+    assert( p->pOffset==0 );
+    assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
+    if( p->pPrior==0 ) break;
+    assert( p->pPrior->pNext==p );
+    p = p->pPrior;
+    nRow++;
+  }while(1);
+  while( p ){
+    pPrior = p->pPrior;
+    p->pPrior = 0;
+    rc = sqlite3Select(pParse, p, pDest);
+    p->pPrior = pPrior;
+    if( rc ) break;
+    p->nSelectRow = nRow;
+    p = p->pNext;
+  }
+  return rc;
+}
 
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
 /*
 ** This routine is called to process a compound query form from
 ** two or more separate queries using UNION, UNION ALL, EXCEPT, or
@@ -94263,18 +115709,17 @@ static int multiSelect(
   Select *pDelete = 0;  /* Chain of simple selects to delete */
   sqlite3 *db;          /* Database connection */
 #ifndef SQLITE_OMIT_EXPLAIN
-  int iSub1;            /* EQP id of left-hand query */
-  int iSub2;            /* EQP id of right-hand query */
+  int iSub1 = 0;        /* EQP id of left-hand query */
+  int iSub2 = 0;        /* EQP id of right-hand query */
 #endif
 
   /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
   ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
   */
   assert( p && p->pPrior );  /* Calling function guarantees this much */
+  assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );
   db = pParse->db;
   pPrior = p->pPrior;
-  assert( pPrior->pRightmost!=pPrior );
-  assert( pPrior->pRightmost==p->pRightmost );
   dest = *pDest;
   if( pPrior->pOrderBy ){
     sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
@@ -94296,27 +115741,34 @@ static int multiSelect(
   */
   if( dest.eDest==SRT_EphemTab ){
     assert( p->pEList );
-    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iParm, p->pEList->nExpr);
-    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
+    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);
     dest.eDest = SRT_Table;
   }
 
+  /* Special handling for a compound-select that originates as a VALUES clause.
+  */
+  if( p->selFlags & SF_MultiValue ){
+    rc = multiSelectValues(pParse, p, &dest);
+    goto multi_select_end;
+  }
+
   /* Make sure all SELECTs in the statement have the same number of elements
   ** in their result sets.
   */
   assert( p->pEList && pPrior->pEList );
-  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
-    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
-      " do not have the same number of result columns", selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
+  assert( p->pEList->nExpr==pPrior->pEList->nExpr );
+
+#ifndef SQLITE_OMIT_CTE
+  if( p->selFlags & SF_Recursive ){
+    generateWithRecursiveQuery(pParse, p, &dest);
+  }else
+#endif
 
   /* Compound SELECTs that have an ORDER BY clause are handled separately.
   */
   if( p->pOrderBy ){
     return multiSelectOrderBy(pParse, p, pDest);
-  }
+  }else
 
   /* Generate code for the left and right SELECT statements.
   */
@@ -94325,6 +115777,8 @@ static int multiSelect(
       int addr = 0;
       int nLimit;
       assert( !pPrior->pLimit );
+      pPrior->iLimit = p->iLimit;
+      pPrior->iOffset = p->iOffset;
       pPrior->pLimit = p->pLimit;
       pPrior->pOffset = p->pOffset;
       explainSetInteger(iSub1, pParse->iNextSelectId);
@@ -94338,20 +115792,24 @@ static int multiSelect(
       p->iLimit = pPrior->iLimit;
       p->iOffset = pPrior->iOffset;
       if( p->iLimit ){
-        addr = sqlite3VdbeAddOp1(v, OP_IfZero, p->iLimit);
+        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
         VdbeComment((v, "Jump ahead if LIMIT reached"));
+        if( p->iOffset ){
+          sqlite3VdbeAddOp3(v, OP_OffsetLimit,
+                            p->iLimit, p->iOffset+1, p->iOffset);
+        }
       }
       explainSetInteger(iSub2, pParse->iNextSelectId);
       rc = sqlite3Select(pParse, p, &dest);
       testcase( rc!=SQLITE_OK );
       pDelete = p->pPrior;
       p->pPrior = pPrior;
-      p->nSelectRow += pPrior->nSelectRow;
+      p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
       if( pPrior->pLimit
        && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
-       && p->nSelectRow > (double)nLimit 
+       && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit) 
       ){
-        p->nSelectRow = (double)nLimit;
+        p->nSelectRow = sqlite3LogEst((u64)nLimit);
       }
       if( addr ){
         sqlite3VdbeJumpHere(v, addr);
@@ -94370,15 +115828,13 @@ static int multiSelect(
       testcase( p->op==TK_EXCEPT );
       testcase( p->op==TK_UNION );
       priorOp = SRT_Union;
-      if( dest.eDest==priorOp && ALWAYS(!p->pLimit &&!p->pOffset) ){
+      if( dest.eDest==priorOp ){
         /* We can reuse a temporary table generated by a SELECT to our
         ** right.
         */
-        assert( p->pRightmost!=p );  /* Can only happen for leftward elements
-                                     ** of a 3-way or more compound */
         assert( p->pLimit==0 );      /* Not allowed on leftward elements */
         assert( p->pOffset==0 );     /* Not allowed on leftward elements */
-        unionTab = dest.iParm;
+        unionTab = dest.iSDParm;
       }else{
         /* We will need to create our own temporary table to hold the
         ** intermediate results.
@@ -94388,7 +115844,7 @@ static int multiSelect(
         addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
         assert( p->addrOpenEphm[0] == -1 );
         p->addrOpenEphm[0] = addr;
-        p->pRightmost->selFlags |= SF_UsesEphemeral;
+        findRightmost(p)->selFlags |= SF_UsesEphemeral;
         assert( p->pEList );
       }
 
@@ -94425,7 +115881,9 @@ static int multiSelect(
       pDelete = p->pPrior;
       p->pPrior = pPrior;
       p->pOrderBy = 0;
-      if( p->op==TK_UNION ) p->nSelectRow += pPrior->nSelectRow;
+      if( p->op==TK_UNION ){
+        p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
+      }
       sqlite3ExprDelete(db, p->pLimit);
       p->pLimit = pLimit;
       p->pOffset = pOffset;
@@ -94435,24 +115893,24 @@ static int multiSelect(
       /* Convert the data in the temporary table into whatever form
       ** it is that we currently need.
       */
-      assert( unionTab==dest.iParm || dest.eDest!=priorOp );
+      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
       if( dest.eDest!=priorOp ){
         int iCont, iBreak, iStart;
         assert( p->pEList );
         if( dest.eDest==SRT_Output ){
           Select *pFirst = p;
           while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-          generateColumnNames(pParse, 0, pFirst->pEList);
+          generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
         }
         iBreak = sqlite3VdbeMakeLabel(v);
         iCont = sqlite3VdbeMakeLabel(v);
         computeLimitRegisters(pParse, p, iBreak);
-        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak);
+        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
         iStart = sqlite3VdbeCurrentAddr(v);
-        selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
-                        0, -1, &dest, iCont, iBreak);
+        selectInnerLoop(pParse, p, p->pEList, unionTab,
+                        0, 0, &dest, iCont, iBreak);
         sqlite3VdbeResolveLabel(v, iCont);
-        sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart);
+        sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); VdbeCoverage(v);
         sqlite3VdbeResolveLabel(v, iBreak);
         sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
       }
@@ -94477,7 +115935,7 @@ static int multiSelect(
       addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
       assert( p->addrOpenEphm[0] == -1 );
       p->addrOpenEphm[0] = addr;
-      p->pRightmost->selFlags |= SF_UsesEphemeral;
+      findRightmost(p)->selFlags |= SF_UsesEphemeral;
       assert( p->pEList );
 
       /* Code the SELECTs to our left into temporary table "tab1".
@@ -94499,7 +115957,7 @@ static int multiSelect(
       p->pLimit = 0;
       pOffset = p->pOffset;
       p->pOffset = 0;
-      intersectdest.iParm = tab2;
+      intersectdest.iSDParm = tab2;
       explainSetInteger(iSub2, pParse->iNextSelectId);
       rc = sqlite3Select(pParse, p, &intersectdest);
       testcase( rc!=SQLITE_OK );
@@ -94517,20 +115975,20 @@ static int multiSelect(
       if( dest.eDest==SRT_Output ){
         Select *pFirst = p;
         while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-        generateColumnNames(pParse, 0, pFirst->pEList);
+        generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
       }
       iBreak = sqlite3VdbeMakeLabel(v);
       iCont = sqlite3VdbeMakeLabel(v);
       computeLimitRegisters(pParse, p, iBreak);
-      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak);
+      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
       r1 = sqlite3GetTempReg(pParse);
       iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);
-      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);
       sqlite3ReleaseTempReg(pParse, r1);
-      selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
-                      0, -1, &dest, iCont, iBreak);
+      selectInnerLoop(pParse, p, p->pEList, tab1,
+                      0, 0, &dest, iCont, iBreak);
       sqlite3VdbeResolveLabel(v, iCont);
-      sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart);
+      sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);
       sqlite3VdbeResolveLabel(v, iBreak);
       sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
       sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
@@ -94556,18 +116014,13 @@ static int multiSelect(
     CollSeq **apColl;             /* For looping through pKeyInfo->aColl[] */
     int nCol;                     /* Number of columns in result set */
 
-    assert( p->pRightmost==p );
+    assert( p->pNext==0 );
     nCol = p->pEList->nExpr;
-    pKeyInfo = sqlite3DbMallocZero(db,
-                       sizeof(*pKeyInfo)+nCol*(sizeof(CollSeq*) + 1));
+    pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
     if( !pKeyInfo ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
       goto multi_select_end;
     }
-
-    pKeyInfo->enc = ENC(db);
-    pKeyInfo->nField = (u16)nCol;
-
     for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
       *apColl = multiSelectCollSeq(pParse, p, i);
       if( 0==*apColl ){
@@ -94585,27 +116038,41 @@ static int multiSelect(
           break;
         }
         sqlite3VdbeChangeP2(v, addr, nCol);
-        sqlite3VdbeChangeP4(v, addr, (char*)pKeyInfo, P4_KEYINFO);
+        sqlite3VdbeChangeP4(v, addr, (char*)sqlite3KeyInfoRef(pKeyInfo),
+                            P4_KEYINFO);
         pLoop->addrOpenEphm[i] = -1;
       }
     }
-    sqlite3DbFree(db, pKeyInfo);
+    sqlite3KeyInfoUnref(pKeyInfo);
   }
 
 multi_select_end:
-  pDest->iMem = dest.iMem;
-  pDest->nMem = dest.nMem;
+  pDest->iSdst = dest.iSdst;
+  pDest->nSdst = dest.nSdst;
   sqlite3SelectDelete(db, pDelete);
   return rc;
 }
 #endif /* SQLITE_OMIT_COMPOUND_SELECT */
 
 /*
+** Error message for when two or more terms of a compound select have different
+** size result sets.
+*/
+SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){
+  if( p->selFlags & SF_Values ){
+    sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
+  }else{
+    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
+      " do not have the same number of result columns", selectOpName(p->op));
+  }
+}
+
+/*
 ** Code an output subroutine for a coroutine implementation of a
 ** SELECT statment.
 **
-** The data to be output is contained in pIn->iMem.  There are
-** pIn->nMem columns to be output.  pDest is where the output should
+** The data to be output is contained in pIn->iSdst.  There are
+** pIn->nSdst columns to be output.  pDest is where the output should
 ** be sent.
 **
 ** regReturn is the number of the register holding the subroutine
@@ -94628,7 +116095,6 @@ static int generateOutputSubroutine(
   int regReturn,          /* The return address register */
   int regPrev,            /* Previous result register.  No uniqueness if 0 */
   KeyInfo *pKeyInfo,      /* For comparing with previous entry */
-  int p4type,             /* The p4 type for pKeyInfo */
   int iBreak              /* Jump here if we hit the LIMIT */
 ){
   Vdbe *v = pParse->pVdbe;
@@ -94641,33 +116107,32 @@ static int generateOutputSubroutine(
   /* Suppress duplicates for UNION, EXCEPT, and INTERSECT 
   */
   if( regPrev ){
-    int j1, j2;
-    j1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev);
-    j2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iMem, regPrev+1, pIn->nMem,
-                              (char*)pKeyInfo, p4type);
-    sqlite3VdbeAddOp3(v, OP_Jump, j2+2, iContinue, j2+2);
-    sqlite3VdbeJumpHere(v, j1);
-    sqlite3ExprCodeCopy(pParse, pIn->iMem, regPrev+1, pIn->nMem);
+    int addr1, addr2;
+    addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
+    addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
+                              (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
+    sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr1);
+    sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);
     sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
   }
   if( pParse->db->mallocFailed ) return 0;
 
-  /* Suppress the the first OFFSET entries if there is an OFFSET clause
+  /* Suppress the first OFFSET entries if there is an OFFSET clause
   */
-  codeOffset(v, p, iContinue);
+  codeOffset(v, p->iOffset, iContinue);
 
+  assert( pDest->eDest!=SRT_Exists );
+  assert( pDest->eDest!=SRT_Table );
   switch( pDest->eDest ){
     /* Store the result as data using a unique key.
     */
-    case SRT_Table:
     case SRT_EphemTab: {
       int r1 = sqlite3GetTempReg(pParse);
       int r2 = sqlite3GetTempReg(pParse);
-      testcase( pDest->eDest==SRT_Table );
-      testcase( pDest->eDest==SRT_EphemTab );
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iMem, pIn->nMem, r1);
-      sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iParm, r2);
-      sqlite3VdbeAddOp3(v, OP_Insert, pDest->iParm, r1, r2);
+      sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);
+      sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);
+      sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);
       sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
       sqlite3ReleaseTempReg(pParse, r2);
       sqlite3ReleaseTempReg(pParse, r1);
@@ -94681,49 +116146,39 @@ static int generateOutputSubroutine(
     */
     case SRT_Set: {
       int r1;
-      assert( pIn->nMem==1 );
-      p->affinity = 
-         sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affinity);
+      assert( pIn->nSdst==1 || pParse->nErr>0 );
+      pDest->affSdst = 
+         sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affSdst);
       r1 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iMem, 1, r1, &p->affinity, 1);
-      sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, 1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iParm, r1);
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, 1, r1, &pDest->affSdst,1);
+      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, 1);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iSDParm, r1);
       sqlite3ReleaseTempReg(pParse, r1);
       break;
     }
 
-#if 0  /* Never occurs on an ORDER BY query */
-    /* If any row exist in the result set, record that fact and abort.
-    */
-    case SRT_Exists: {
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, pDest->iParm);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-#endif
-
     /* If this is a scalar select that is part of an expression, then
     ** store the results in the appropriate memory cell and break out
     ** of the scan loop.
     */
     case SRT_Mem: {
-      assert( pIn->nMem==1 );
-      sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iParm, 1);
+      assert( pIn->nSdst==1 || pParse->nErr>0 );  testcase( pIn->nSdst!=1 );
+      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1);
       /* The LIMIT clause will jump out of the loop for us */
       break;
     }
 #endif /* #ifndef SQLITE_OMIT_SUBQUERY */
 
     /* The results are stored in a sequence of registers
-    ** starting at pDest->iMem.  Then the co-routine yields.
+    ** starting at pDest->iSdst.  Then the co-routine yields.
     */
     case SRT_Coroutine: {
-      if( pDest->iMem==0 ){
-        pDest->iMem = sqlite3GetTempRange(pParse, pIn->nMem);
-        pDest->nMem = pIn->nMem;
+      if( pDest->iSdst==0 ){
+        pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);
+        pDest->nSdst = pIn->nSdst;
       }
-      sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iMem, pDest->nMem);
-      sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm);
+      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);
+      sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
       break;
     }
 
@@ -94737,8 +116192,8 @@ static int generateOutputSubroutine(
     */
     default: {
       assert( pDest->eDest==SRT_Output );
-      sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iMem, pIn->nMem);
-      sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, pIn->nMem);
+      sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iSdst, pIn->nSdst);
+      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
       break;
     }
   }
@@ -94746,7 +116201,7 @@ static int generateOutputSubroutine(
   /* Jump to the end of the loop if the LIMIT is reached.
   */
   if( p->iLimit ){
-    sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1);
+    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
   }
 
   /* Generate the subroutine return
@@ -94854,9 +116309,7 @@ static int multiSelectOrderBy(
   SelectDest destA;     /* Destination for coroutine A */
   SelectDest destB;     /* Destination for coroutine B */
   int regAddrA;         /* Address register for select-A coroutine */
-  int regEofA;          /* Flag to indicate when select-A is complete */
   int regAddrB;         /* Address register for select-B coroutine */
-  int regEofB;          /* Flag to indicate when select-B is complete */
   int addrSelectA;      /* Address of the select-A coroutine */
   int addrSelectB;      /* Address of the select-B coroutine */
   int regOutA;          /* Address register for the output-A subroutine */
@@ -94864,6 +116317,7 @@ static int multiSelectOrderBy(
   int addrOutA;         /* Address of the output-A subroutine */
   int addrOutB = 0;     /* Address of the output-B subroutine */
   int addrEofA;         /* Address of the select-A-exhausted subroutine */
+  int addrEofA_noB;     /* Alternate addrEofA if B is uninitialized */
   int addrEofB;         /* Address of the select-B-exhausted subroutine */
   int addrAltB;         /* Address of the A<B subroutine */
   int addrAeqB;         /* Address of the A==B subroutine */
@@ -94875,7 +116329,7 @@ static int multiSelectOrderBy(
   int savedOffset;      /* Saved value of p->iOffset */
   int labelCmpr;        /* Label for the start of the merge algorithm */
   int labelEnd;         /* Label for the end of the overall SELECT stmt */
-  int j1;               /* Jump instructions that get retargetted */
+  int addr1;            /* Jump instructions that get retargetted */
   int op;               /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
   KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */
   KeyInfo *pKeyMerge;   /* Comparison information for merging rows */
@@ -94914,16 +116368,16 @@ static int multiSelectOrderBy(
     for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){
       struct ExprList_item *pItem;
       for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){
-        assert( pItem->iCol>0 );
-        if( pItem->iCol==i ) break;
+        assert( pItem->u.x.iOrderByCol>0 );
+        if( pItem->u.x.iOrderByCol==i ) break;
       }
       if( j==nOrderBy ){
         Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
-        if( pNew==0 ) return SQLITE_NOMEM;
+        if( pNew==0 ) return SQLITE_NOMEM_BKPT;
         pNew->flags |= EP_IntValue;
         pNew->u.iValue = i;
         pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
-        pOrderBy->a[nOrderBy++].iCol = (u16)i;
+        if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;
       }
     }
   }
@@ -94935,33 +116389,16 @@ static int multiSelectOrderBy(
   ** to the right and the left are evaluated, they use the correct
   ** collation.
   */
-  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
+  aPermute = sqlite3DbMallocRawNN(db, sizeof(int)*(nOrderBy + 1));
   if( aPermute ){
     struct ExprList_item *pItem;
-    for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){
-      assert( pItem->iCol>0  && pItem->iCol<=p->pEList->nExpr );
-      aPermute[i] = pItem->iCol - 1;
-    }
-    pKeyMerge =
-      sqlite3DbMallocRaw(db, sizeof(*pKeyMerge)+nOrderBy*(sizeof(CollSeq*)+1));
-    if( pKeyMerge ){
-      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
-      pKeyMerge->nField = (u16)nOrderBy;
-      pKeyMerge->enc = ENC(db);
-      for(i=0; i<nOrderBy; i++){
-        CollSeq *pColl;
-        Expr *pTerm = pOrderBy->a[i].pExpr;
-        if( pTerm->flags & EP_ExpCollate ){
-          pColl = pTerm->pColl;
-        }else{
-          pColl = multiSelectCollSeq(pParse, p, aPermute[i]);
-          pTerm->flags |= EP_ExpCollate;
-          pTerm->pColl = pColl;
-        }
-        pKeyMerge->aColl[i] = pColl;
-        pKeyMerge->aSortOrder[i] = pOrderBy->a[i].sortOrder;
-      }
+    aPermute[0] = nOrderBy;
+    for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){
+      assert( pItem->u.x.iOrderByCol>0 );
+      assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
+      aPermute[i] = pItem->u.x.iOrderByCol - 1;
     }
+    pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
   }else{
     pKeyMerge = 0;
   }
@@ -94980,14 +116417,12 @@ static int multiSelectOrderBy(
   }else{
     int nExpr = p->pEList->nExpr;
     assert( nOrderBy>=nExpr || db->mallocFailed );
-    regPrev = sqlite3GetTempRange(pParse, nExpr+1);
+    regPrev = pParse->nMem+1;
+    pParse->nMem += nExpr+1;
     sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
-    pKeyDup = sqlite3DbMallocZero(db,
-                  sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) );
+    pKeyDup = sqlite3KeyInfoAlloc(db, nExpr, 1);
     if( pKeyDup ){
-      pKeyDup->aSortOrder = (u8*)&pKeyDup->aColl[nExpr];
-      pKeyDup->nField = (u16)nExpr;
-      pKeyDup->enc = ENC(db);
+      assert( sqlite3KeyInfoIsWriteable(pKeyDup) );
       for(i=0; i<nExpr; i++){
         pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
         pKeyDup->aSortOrder[i] = 0;
@@ -94998,6 +116433,7 @@ static int multiSelectOrderBy(
   /* Separate the left and the right query from one another
   */
   p->pPrior = 0;
+  pPrior->pNext = 0;
   sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");
   if( pPrior->pPrior==0 ){
     sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");
@@ -95020,37 +116456,30 @@ static int multiSelectOrderBy(
   p->pOffset = 0;
 
   regAddrA = ++pParse->nMem;
-  regEofA = ++pParse->nMem;
   regAddrB = ++pParse->nMem;
-  regEofB = ++pParse->nMem;
   regOutA = ++pParse->nMem;
   regOutB = ++pParse->nMem;
   sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
   sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
 
-  /* Jump past the various subroutines and coroutines to the main
-  ** merge loop
-  */
-  j1 = sqlite3VdbeAddOp0(v, OP_Goto);
-  addrSelectA = sqlite3VdbeCurrentAddr(v);
-
-
   /* Generate a coroutine to evaluate the SELECT statement to the
   ** left of the compound operator - the "A" select.
   */
-  VdbeNoopComment((v, "Begin coroutine for left SELECT"));
+  addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
+  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
+  VdbeComment((v, "left SELECT"));
   pPrior->iLimit = regLimitA;
   explainSetInteger(iSub1, pParse->iNextSelectId);
   sqlite3Select(pParse, pPrior, &destA);
-  sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofA);
-  sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
-  VdbeNoopComment((v, "End coroutine for left SELECT"));
+  sqlite3VdbeEndCoroutine(v, regAddrA);
+  sqlite3VdbeJumpHere(v, addr1);
 
   /* Generate a coroutine to evaluate the SELECT statement on 
   ** the right - the "B" select
   */
-  addrSelectB = sqlite3VdbeCurrentAddr(v);
-  VdbeNoopComment((v, "Begin coroutine for right SELECT"));
+  addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
+  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
+  VdbeComment((v, "right SELECT"));
   savedLimit = p->iLimit;
   savedOffset = p->iOffset;
   p->iLimit = regLimitB;
@@ -95059,9 +116488,7 @@ static int multiSelectOrderBy(
   sqlite3Select(pParse, p, &destB);
   p->iLimit = savedLimit;
   p->iOffset = savedOffset;
-  sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofB);
-  sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
-  VdbeNoopComment((v, "End coroutine for right SELECT"));
+  sqlite3VdbeEndCoroutine(v, regAddrB);
 
   /* Generate a subroutine that outputs the current row of the A
   ** select as the next output row of the compound select.
@@ -95069,7 +116496,7 @@ static int multiSelectOrderBy(
   VdbeNoopComment((v, "Output routine for A"));
   addrOutA = generateOutputSubroutine(pParse,
                  p, &destA, pDest, regOutA,
-                 regPrev, pKeyDup, P4_KEYINFO_HANDOFF, labelEnd);
+                 regPrev, pKeyDup, labelEnd);
   
   /* Generate a subroutine that outputs the current row of the B
   ** select as the next output row of the compound select.
@@ -95078,21 +116505,22 @@ static int multiSelectOrderBy(
     VdbeNoopComment((v, "Output routine for B"));
     addrOutB = generateOutputSubroutine(pParse,
                  p, &destB, pDest, regOutB,
-                 regPrev, pKeyDup, P4_KEYINFO_STATIC, labelEnd);
+                 regPrev, pKeyDup, labelEnd);
   }
+  sqlite3KeyInfoUnref(pKeyDup);
 
   /* Generate a subroutine to run when the results from select A
   ** are exhausted and only data in select B remains.
   */
-  VdbeNoopComment((v, "eof-A subroutine"));
   if( op==TK_EXCEPT || op==TK_INTERSECT ){
-    addrEofA = sqlite3VdbeAddOp2(v, OP_Goto, 0, labelEnd);
+    addrEofA_noB = addrEofA = labelEnd;
   }else{  
-    addrEofA = sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd);
-    sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
-    sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofA);
-    p->nSelectRow += pPrior->nSelectRow;
+    VdbeNoopComment((v, "eof-A subroutine"));
+    addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
+    addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);
+                                     VdbeCoverage(v);
+    sqlite3VdbeGoto(v, addrEofA);
+    p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
   }
 
   /* Generate a subroutine to run when the results from select B
@@ -95103,19 +116531,17 @@ static int multiSelectOrderBy(
     if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
   }else{  
     VdbeNoopComment((v, "eof-B subroutine"));
-    addrEofB = sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd);
-    sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
-    sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofB);
+    addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+    sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);
+    sqlite3VdbeGoto(v, addrEofB);
   }
 
   /* Generate code to handle the case of A<B
   */
   VdbeNoopComment((v, "A-lt-B subroutine"));
   addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
-  sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
-  sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
-  sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+  sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
+  sqlite3VdbeGoto(v, labelCmpr);
 
   /* Generate code to handle the case of A==B
   */
@@ -95127,9 +116553,8 @@ static int multiSelectOrderBy(
   }else{
     VdbeNoopComment((v, "A-eq-B subroutine"));
     addrAeqB =
-    sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
-    sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+    sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
+    sqlite3VdbeGoto(v, labelCmpr);
   }
 
   /* Generate code to handle the case of A>B
@@ -95139,33 +116564,23 @@ static int multiSelectOrderBy(
   if( op==TK_ALL || op==TK_UNION ){
     sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
   }
-  sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
-  sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB);
-  sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr);
+  sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
+  sqlite3VdbeGoto(v, labelCmpr);
 
   /* This code runs once to initialize everything.
   */
-  sqlite3VdbeJumpHere(v, j1);
-  sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofA);
-  sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofB);
-  sqlite3VdbeAddOp2(v, OP_Gosub, regAddrA, addrSelectA);
-  sqlite3VdbeAddOp2(v, OP_Gosub, regAddrB, addrSelectB);
-  sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
-  sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB);
+  sqlite3VdbeJumpHere(v, addr1);
+  sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);
+  sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
 
   /* Implement the main merge loop
   */
   sqlite3VdbeResolveLabel(v, labelCmpr);
   sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
-  sqlite3VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, nOrderBy,
-                         (char*)pKeyMerge, P4_KEYINFO_HANDOFF);
-  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);
-
-  /* Release temporary registers
-  */
-  if( regPrev ){
-    sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1);
-  }
+  sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
+                         (char*)pKeyMerge, P4_KEYINFO);
+  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
+  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);
 
   /* Jump to the this point in order to terminate the query.
   */
@@ -95176,7 +116591,7 @@ static int multiSelectOrderBy(
   if( pDest->eDest==SRT_Output ){
     Select *pFirst = pPrior;
     while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-    generateColumnNames(pParse, 0, pFirst->pEList);
+    generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
   }
 
   /* Reassembly the compound query so that it will be freed correctly
@@ -95185,18 +116600,19 @@ static int multiSelectOrderBy(
     sqlite3SelectDelete(db, p->pPrior);
   }
   p->pPrior = pPrior;
+  pPrior->pNext = p;
 
   /*** TBD:  Insert subroutine calls to close cursors on incomplete
   **** subqueries ****/
   explainComposite(pParse, p->op, iSub1, iSub2, 0);
-  return SQLITE_OK;
+  return pParse->nErr!=0;
 }
 #endif
 
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
 /* Forward Declarations */
 static void substExprList(sqlite3*, ExprList*, int, ExprList*);
-static void substSelect(sqlite3*, Select *, int, ExprList *);
+static void substSelect(sqlite3*, Select *, int, ExprList*, int);
 
 /*
 ** Scan through the expression pExpr.  Replace every reference to
@@ -95226,9 +116642,6 @@ static Expr *substExpr(
       assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
       assert( pExpr->pLeft==0 && pExpr->pRight==0 );
       pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0);
-      if( pNew && pExpr->pColl ){
-        pNew->pColl = pExpr->pColl;
-      }
       sqlite3ExprDelete(db, pExpr);
       pExpr = pNew;
     }
@@ -95236,7 +116649,7 @@ static Expr *substExpr(
     pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList);
     pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList);
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      substSelect(db, pExpr->x.pSelect, iTable, pEList);
+      substSelect(db, pExpr->x.pSelect, iTable, pEList, 1);
     }else{
       substExprList(db, pExpr->x.pList, iTable, pEList);
     }
@@ -95259,33 +116672,35 @@ static void substSelect(
   sqlite3 *db,         /* Report malloc errors here */
   Select *p,           /* SELECT statement in which to make substitutions */
   int iTable,          /* Table to be replaced */
-  ExprList *pEList     /* Substitute values */
+  ExprList *pEList,    /* Substitute values */
+  int doPrior          /* Do substitutes on p->pPrior too */
 ){
   SrcList *pSrc;
   struct SrcList_item *pItem;
   int i;
   if( !p ) return;
-  substExprList(db, p->pEList, iTable, pEList);
-  substExprList(db, p->pGroupBy, iTable, pEList);
-  substExprList(db, p->pOrderBy, iTable, pEList);
-  p->pHaving = substExpr(db, p->pHaving, iTable, pEList);
-  p->pWhere = substExpr(db, p->pWhere, iTable, pEList);
-  substSelect(db, p->pPrior, iTable, pEList);
-  pSrc = p->pSrc;
-  assert( pSrc );  /* Even for (SELECT 1) we have: pSrc!=0 but pSrc->nSrc==0 */
-  if( ALWAYS(pSrc) ){
+  do{
+    substExprList(db, p->pEList, iTable, pEList);
+    substExprList(db, p->pGroupBy, iTable, pEList);
+    substExprList(db, p->pOrderBy, iTable, pEList);
+    p->pHaving = substExpr(db, p->pHaving, iTable, pEList);
+    p->pWhere = substExpr(db, p->pWhere, iTable, pEList);
+    pSrc = p->pSrc;
+    assert( pSrc!=0 );
     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
-      substSelect(db, pItem->pSelect, iTable, pEList);
+      substSelect(db, pItem->pSelect, iTable, pEList, 1);
+      if( pItem->fg.isTabFunc ){
+        substExprList(db, pItem->u1.pFuncArg, iTable, pEList);
+      }
     }
-  }
+  }while( doPrior && (p = p->pPrior)!=0 );
 }
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
 /*
-** This routine attempts to flatten subqueries in order to speed
-** execution.  It returns 1 if it makes changes and 0 if no flattening
-** occurs.
+** This routine attempts to flatten subqueries as a performance optimization.
+** This routine returns 1 if it makes changes and 0 if no flattening occurs.
 **
 ** To understand the concept of flattening, consider the following
 ** query:
@@ -95304,7 +116719,7 @@ static void substSelect(
 **
 **     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
 **
-** The code generated for this simpification gives the same result
+** The code generated for this simplification gives the same result
 ** but only has to scan the data once.  And because indices might 
 ** exist on the table t1, a complete scan of the data might be
 ** avoided.
@@ -95313,7 +116728,10 @@ static void substSelect(
 **
 **   (1)  The subquery and the outer query do not both use aggregates.
 **
-**   (2)  The subquery is not an aggregate or the outer query is not a join.
+**   (2)  The subquery is not an aggregate or (2a) the outer query is not a join
+**        and (2b) the outer query does not use subqueries other than the one
+**        FROM-clause subquery that is a candidate for flattening.  (2b is
+**        due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
 **
 **   (3)  The subquery is not the right operand of a left outer join
 **        (Originally ticket #306.  Strengthened by ticket #3300)
@@ -95327,15 +116745,20 @@ static void substSelect(
 **   (6)  The subquery does not use aggregates or the outer query is not
 **        DISTINCT.
 **
-**   (7)  The subquery has a FROM clause.
+**   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
+**        A FROM clause, consider adding a FROM close with the special
+**        table sqlite_once that consists of a single row containing a
+**        single NULL.
 **
 **   (8)  The subquery does not use LIMIT or the outer query is not a join.
 **
 **   (9)  The subquery does not use LIMIT or the outer query does not use
 **        aggregates.
 **
-**  (10)  The subquery does not use aggregates or the outer query does not
-**        use LIMIT.
+**  (**)  Restriction (10) was removed from the code on 2005-02-05 but we
+**        accidently carried the comment forward until 2014-09-15.  Original
+**        text: "The subquery does not use aggregates or the outer query 
+**        does not use LIMIT."
 **
 **  (11)  The subquery and the outer query do not both have ORDER BY clauses.
 **
@@ -95360,11 +116783,20 @@ static void substSelect(
 **
 **          * is not itself part of a compound select,
 **          * is not an aggregate or DISTINCT query, and
-**          * has no other tables or sub-selects in the FROM clause.
+**          * is not a join
 **
 **        The parent and sub-query may contain WHERE clauses. Subject to
 **        rules (11), (13) and (14), they may also contain ORDER BY,
-**        LIMIT and OFFSET clauses.
+**        LIMIT and OFFSET clauses.  The subquery cannot use any compound
+**        operator other than UNION ALL because all the other compound
+**        operators have an implied DISTINCT which is disallowed by
+**        restriction (4).
+**
+**        Also, each component of the sub-query must return the same number
+**        of result columns. This is actually a requirement for any compound
+**        SELECT statement, but all the code here does is make sure that no
+**        such (illegal) sub-query is flattened. The caller will detect the
+**        syntax error and return a detailed message.
 **
 **  (18)  If the sub-query is a compound select, then all terms of the
 **        ORDER by clause of the parent must be simple references to 
@@ -95376,12 +116808,25 @@ static void substSelect(
 **  (20)  If the sub-query is a compound select, then it must not use
 **        an ORDER BY clause.  Ticket #3773.  We could relax this constraint
 **        somewhat by saying that the terms of the ORDER BY clause must
-**        appear as unmodified result columns in the outer query.  But
+**        appear as unmodified result columns in the outer query.  But we
 **        have other optimizations in mind to deal with that case.
 **
 **  (21)  The subquery does not use LIMIT or the outer query is not
 **        DISTINCT.  (See ticket [752e1646fc]).
 **
+**  (22)  The subquery is not a recursive CTE.
+**
+**  (23)  The parent is not a recursive CTE, or the sub-query is not a
+**        compound query. This restriction is because transforming the
+**        parent to a compound query confuses the code that handles
+**        recursive queries in multiSelect().
+**
+**  (24)  The subquery is not an aggregate that uses the built-in min() or 
+**        or max() functions.  (Without this restriction, a query like:
+**        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
+**        return the value X for which Y was maximal.)
+**
+**
 ** In this routine, the "p" parameter is a pointer to the outer query.
 ** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
 ** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
@@ -95400,7 +116845,7 @@ static int flattenSubquery(
   int subqueryIsAgg    /* True if the subquery uses aggregate functions */
 ){
   const char *zSavedAuthContext = pParse->zAuthContext;
-  Select *pParent;
+  Select *pParent;    /* Current UNION ALL term of the other query */
   Select *pSub;       /* The inner query or "subquery" */
   Select *pSub1;      /* Pointer to the rightmost select in sub-query */
   SrcList *pSrc;      /* The FROM clause of the outer query */
@@ -95416,25 +116861,34 @@ static int flattenSubquery(
   */
   assert( p!=0 );
   assert( p->pPrior==0 );  /* Unable to flatten compound queries */
-  if( db->flags & SQLITE_QueryFlattener ) return 0;
+  if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
   pSrc = p->pSrc;
   assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
   pSubitem = &pSrc->a[iFrom];
   iParent = pSubitem->iCursor;
   pSub = pSubitem->pSelect;
   assert( pSub!=0 );
-  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
-  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
+  if( subqueryIsAgg ){
+    if( isAgg ) return 0;                                /* Restriction (1)   */
+    if( pSrc->nSrc>1 ) return 0;                         /* Restriction (2a)  */
+    if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
+     || (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
+     || (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
+    ){
+      return 0;                                          /* Restriction (2b)  */
+    }
+  }
+    
   pSubSrc = pSub->pSrc;
   assert( pSubSrc );
   /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
-  ** not arbitrary expresssions, we allowed some combining of LIMIT and OFFSET
+  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
   ** because they could be computed at compile-time.  But when LIMIT and OFFSET
   ** became arbitrary expressions, we were forced to add restrictions (13)
   ** and (14). */
   if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
   if( pSub->pOffset ) return 0;                          /* Restriction (14) */
-  if( p->pRightmost && pSub->pLimit ){
+  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
     return 0;                                            /* Restriction (15) */
   }
   if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
@@ -95453,6 +116907,14 @@ static int flattenSubquery(
   if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
      return 0;         /* Restriction (21) */
   }
+  testcase( pSub->selFlags & SF_Recursive );
+  testcase( pSub->selFlags & SF_MinMaxAgg );
+  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
+    return 0; /* Restrictions (22) and (24) */
+  }
+  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
+    return 0; /* Restriction (23) */
+  }
 
   /* OBSOLETE COMMENT 1:
   ** Restriction 3:  If the subquery is a join, make sure the subquery is 
@@ -95486,7 +116948,7 @@ static int flattenSubquery(
   ** is fraught with danger.  Best to avoid the whole thing.  If the
   ** subquery is the right term of a LEFT JOIN, then do not flatten.
   */
-  if( (pSubitem->jointype & JT_OUTER)!=0 ){
+  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
     return 0;
   }
 
@@ -95505,28 +116967,34 @@ static int flattenSubquery(
     for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
+      assert( pSub->pSrc!=0 );
+      assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
       if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0
        || (pSub1->pPrior && pSub1->op!=TK_ALL) 
-       || NEVER(pSub1->pSrc==0) || pSub1->pSrc->nSrc!=1
+       || pSub1->pSrc->nSrc<1
       ){
         return 0;
       }
+      testcase( pSub1->pSrc->nSrc>1 );
     }
 
     /* Restriction 18. */
     if( p->pOrderBy ){
       int ii;
       for(ii=0; ii<p->pOrderBy->nExpr; ii++){
-        if( p->pOrderBy->a[ii].iCol==0 ) return 0;
+        if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;
       }
     }
   }
 
   /***** If we reach this point, flattening is permitted. *****/
+  SELECTTRACE(1,pParse,p,("flatten %s.%p from term %d\n",
+                   pSub->zSelName, pSub, iFrom));
 
   /* Authorize the subquery */
   pParse->zAuthContext = pSubitem->zName;
-  sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
+  TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
+  testcase( i==SQLITE_DENY );
   pParse->zAuthContext = zSavedAuthContext;
 
   /* If the sub-query is a compound SELECT statement, then (by restrictions
@@ -95566,24 +117034,31 @@ static int flattenSubquery(
     Select *pNew;
     ExprList *pOrderBy = p->pOrderBy;
     Expr *pLimit = p->pLimit;
+    Expr *pOffset = p->pOffset;
     Select *pPrior = p->pPrior;
     p->pOrderBy = 0;
     p->pSrc = 0;
     p->pPrior = 0;
     p->pLimit = 0;
+    p->pOffset = 0;
     pNew = sqlite3SelectDup(db, p, 0);
+    sqlite3SelectSetName(pNew, pSub->zSelName);
+    p->pOffset = pOffset;
     p->pLimit = pLimit;
     p->pOrderBy = pOrderBy;
     p->pSrc = pSrc;
     p->op = TK_ALL;
-    p->pRightmost = 0;
     if( pNew==0 ){
-      pNew = pPrior;
+      p->pPrior = pPrior;
     }else{
       pNew->pPrior = pPrior;
-      pNew->pRightmost = 0;
+      if( pPrior ) pPrior->pNext = pNew;
+      pNew->pNext = p;
+      p->pPrior = pNew;
+      SELECTTRACE(2,pParse,p,
+         ("compound-subquery flattener creates %s.%p as peer\n",
+         pNew->zSelName, pNew));
     }
-    p->pPrior = pNew;
     if( db->mallocFailed ) return 1;
   }
 
@@ -95644,7 +117119,7 @@ static int flattenSubquery(
 
     if( pSrc ){
       assert( pParent==p );  /* First time through the loop */
-      jointype = pSubitem->jointype;
+      jointype = pSubitem->fg.jointype;
     }else{
       assert( pParent!=p );  /* 2nd and subsequent times through the loop */
       pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
@@ -95665,9 +117140,9 @@ static int flattenSubquery(
     **
     ** The outer query has 3 slots in its FROM clause.  One slot of the
     ** outer query (the middle slot) is used by the subquery.  The next
-    ** block of code will expand the out query to 4 slots.  The middle
-    ** slot is expanded to two slots in order to make space for the
-    ** two elements in the FROM clause of the subquery.
+    ** block of code will expand the outer query FROM clause to 4 slots.
+    ** The middle slot is expanded to two slots in order to make space
+    ** for the two elements in the FROM clause of the subquery.
     */
     if( nSubSrc>1 ){
       pParent->pSrc = pSrc = sqlite3SrcListEnlarge(db, pSrc, nSubSrc-1,iFrom+1);
@@ -95681,10 +117156,11 @@ static int flattenSubquery(
     */
     for(i=0; i<nSubSrc; i++){
       sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
+      assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
       pSrc->a[i+iFrom] = pSubSrc->a[i];
       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
     }
-    pSrc->a[iFrom].jointype = jointype;
+    pSrc->a[iFrom].fg.jointype = jointype;
   
     /* Now begin substituting subquery result set expressions for 
     ** references to the iParent in the outer query.
@@ -95701,42 +117177,44 @@ static int flattenSubquery(
     pList = pParent->pEList;
     for(i=0; i<pList->nExpr; i++){
       if( pList->a[i].zName==0 ){
-        const char *zSpan = pList->a[i].zSpan;
-        if( ALWAYS(zSpan) ){
-          pList->a[i].zName = sqlite3DbStrDup(db, zSpan);
-        }
+        char *zName = sqlite3DbStrDup(db, pList->a[i].zSpan);
+        sqlite3Dequote(zName);
+        pList->a[i].zName = zName;
       }
     }
-    substExprList(db, pParent->pEList, iParent, pSub->pEList);
-    if( isAgg ){
-      substExprList(db, pParent->pGroupBy, iParent, pSub->pEList);
-      pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList);
-    }
     if( pSub->pOrderBy ){
+      /* At this point, any non-zero iOrderByCol values indicate that the
+      ** ORDER BY column expression is identical to the iOrderByCol'th
+      ** expression returned by SELECT statement pSub. Since these values
+      ** do not necessarily correspond to columns in SELECT statement pParent,
+      ** zero them before transfering the ORDER BY clause.
+      **
+      ** Not doing this may cause an error if a subsequent call to this
+      ** function attempts to flatten a compound sub-query into pParent
+      ** (the only way this can happen is if the compound sub-query is
+      ** currently part of pSub->pSrc). See ticket [d11a6e908f].  */
+      ExprList *pOrderBy = pSub->pOrderBy;
+      for(i=0; i<pOrderBy->nExpr; i++){
+        pOrderBy->a[i].u.x.iOrderByCol = 0;
+      }
       assert( pParent->pOrderBy==0 );
-      pParent->pOrderBy = pSub->pOrderBy;
+      assert( pSub->pPrior==0 );
+      pParent->pOrderBy = pOrderBy;
       pSub->pOrderBy = 0;
-    }else if( pParent->pOrderBy ){
-      substExprList(db, pParent->pOrderBy, iParent, pSub->pEList);
-    }
-    if( pSub->pWhere ){
-      pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
-    }else{
-      pWhere = 0;
     }
+    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
     if( subqueryIsAgg ){
       assert( pParent->pHaving==0 );
       pParent->pHaving = pParent->pWhere;
       pParent->pWhere = pWhere;
-      pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList);
       pParent->pHaving = sqlite3ExprAnd(db, pParent->pHaving, 
                                   sqlite3ExprDup(db, pSub->pHaving, 0));
       assert( pParent->pGroupBy==0 );
       pParent->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy, 0);
     }else{
-      pParent->pWhere = substExpr(db, pParent->pWhere, iParent, pSub->pEList);
       pParent->pWhere = sqlite3ExprAnd(db, pParent->pWhere, pWhere);
     }
+    substSelect(db, pParent, iParent, pSub->pEList, 0);
   
     /* The flattened query is distinct if either the inner or the
     ** outer query is distinct. 
@@ -95760,44 +117238,137 @@ static int flattenSubquery(
   */
   sqlite3SelectDelete(db, pSub1);
 
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x100 ){
+    SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
+
   return 1;
 }
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
+
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+/*
+** Make copies of relevant WHERE clause terms of the outer query into
+** the WHERE clause of subquery.  Example:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
+**
+** Transformed into:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
+**     WHERE x=5 AND y=10;
+**
+** The hope is that the terms added to the inner query will make it more
+** efficient.
+**
+** Do not attempt this optimization if:
+**
+**   (1) The inner query is an aggregate.  (In that case, we'd really want
+**       to copy the outer WHERE-clause terms onto the HAVING clause of the
+**       inner query.  But they probably won't help there so do not bother.)
+**
+**   (2) The inner query is the recursive part of a common table expression.
+**
+**   (3) The inner query has a LIMIT clause (since the changes to the WHERE
+**       close would change the meaning of the LIMIT).
+**
+**   (4) The inner query is the right operand of a LEFT JOIN.  (The caller
+**       enforces this restriction since this routine does not have enough
+**       information to know.)
+**
+**   (5) The WHERE clause expression originates in the ON or USING clause
+**       of a LEFT JOIN.
+**
+** Return 0 if no changes are made and non-zero if one or more WHERE clause
+** terms are duplicated into the subquery.
+*/
+static int pushDownWhereTerms(
+  sqlite3 *db,          /* The database connection (for malloc()) */
+  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
+  Expr *pWhere,         /* The WHERE clause of the outer query */
+  int iCursor           /* Cursor number of the subquery */
+){
+  Expr *pNew;
+  int nChng = 0;
+  Select *pX;           /* For looping over compound SELECTs in pSubq */
+  if( pWhere==0 ) return 0;
+  for(pX=pSubq; pX; pX=pX->pPrior){
+    if( (pX->selFlags & (SF_Aggregate|SF_Recursive))!=0 ){
+      testcase( pX->selFlags & SF_Aggregate );
+      testcase( pX->selFlags & SF_Recursive );
+      testcase( pX!=pSubq );
+      return 0; /* restrictions (1) and (2) */
+    }
+  }
+  if( pSubq->pLimit!=0 ){
+    return 0; /* restriction (3) */
+  }
+  while( pWhere->op==TK_AND ){
+    nChng += pushDownWhereTerms(db, pSubq, pWhere->pRight, iCursor);
+    pWhere = pWhere->pLeft;
+  }
+  if( ExprHasProperty(pWhere,EP_FromJoin) ) return 0; /* restriction 5 */
+  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
+    nChng++;
+    while( pSubq ){
+      pNew = sqlite3ExprDup(db, pWhere, 0);
+      pNew = substExpr(db, pNew, iCursor, pSubq->pEList);
+      pSubq->pWhere = sqlite3ExprAnd(db, pSubq->pWhere, pNew);
+      pSubq = pSubq->pPrior;
+    }
+  }
+  return nChng;
+}
+#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
+
 /*
-** Analyze the SELECT statement passed as an argument to see if it
-** is a min() or max() query. Return WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX if 
-** it is, or 0 otherwise. At present, a query is considered to be
-** a min()/max() query if:
+** Based on the contents of the AggInfo structure indicated by the first
+** argument, this function checks if the following are true:
 **
-**   1. There is a single object in the FROM clause.
+**    * the query contains just a single aggregate function,
+**    * the aggregate function is either min() or max(), and
+**    * the argument to the aggregate function is a column value.
 **
-**   2. There is a single expression in the result set, and it is
-**      either min(x) or max(x), where x is a column reference.
+** If all of the above are true, then WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX
+** is returned as appropriate. Also, *ppMinMax is set to point to the 
+** list of arguments passed to the aggregate before returning.
+**
+** Or, if the conditions above are not met, *ppMinMax is set to 0 and
+** WHERE_ORDERBY_NORMAL is returned.
 */
-static u8 minMaxQuery(Select *p){
-  Expr *pExpr;
-  ExprList *pEList = p->pEList;
+static u8 minMaxQuery(AggInfo *pAggInfo, ExprList **ppMinMax){
+  int eRet = WHERE_ORDERBY_NORMAL;          /* Return value */
 
-  if( pEList->nExpr!=1 ) return WHERE_ORDERBY_NORMAL;
-  pExpr = pEList->a[0].pExpr;
-  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
-  if( NEVER(ExprHasProperty(pExpr, EP_xIsSelect)) ) return 0;
-  pEList = pExpr->x.pList;
-  if( pEList==0 || pEList->nExpr!=1 ) return 0;
-  if( pEList->a[0].pExpr->op!=TK_AGG_COLUMN ) return WHERE_ORDERBY_NORMAL;
-  assert( !ExprHasProperty(pExpr, EP_IntValue) );
-  if( sqlite3StrICmp(pExpr->u.zToken,"min")==0 ){
-    return WHERE_ORDERBY_MIN;
-  }else if( sqlite3StrICmp(pExpr->u.zToken,"max")==0 ){
-    return WHERE_ORDERBY_MAX;
+  *ppMinMax = 0;
+  if( pAggInfo->nFunc==1 ){
+    Expr *pExpr = pAggInfo->aFunc[0].pExpr; /* Aggregate function */
+    ExprList *pEList = pExpr->x.pList;      /* Arguments to agg function */
+
+    assert( pExpr->op==TK_AGG_FUNCTION );
+    if( pEList && pEList->nExpr==1 && pEList->a[0].pExpr->op==TK_AGG_COLUMN ){
+      const char *zFunc = pExpr->u.zToken;
+      if( sqlite3StrICmp(zFunc, "min")==0 ){
+        eRet = WHERE_ORDERBY_MIN;
+        *ppMinMax = pEList;
+      }else if( sqlite3StrICmp(zFunc, "max")==0 ){
+        eRet = WHERE_ORDERBY_MAX;
+        *ppMinMax = pEList;
+      }
+    }
   }
-  return WHERE_ORDERBY_NORMAL;
+
+  assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 );
+  return eRet;
 }
 
 /*
 ** The select statement passed as the first argument is an aggregate query.
-** The second argment is the associated aggregate-info object. This 
+** The second argument is the associated aggregate-info object. This 
 ** function tests if the SELECT is of the form:
 **
 **   SELECT count(*) FROM <tbl>
@@ -95823,7 +117394,8 @@ static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
 
   if( IsVirtual(pTab) ) return 0;
   if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
-  if( (pAggInfo->aFunc[0].pFunc->flags&SQLITE_FUNC_COUNT)==0 ) return 0;
+  if( NEVER(pAggInfo->nFunc==0) ) return 0;
+  if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
   if( pExpr->flags&EP_Distinct ) return 0;
 
   return pTab;
@@ -95837,23 +117409,301 @@ static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
 ** pFrom->pIndex and return SQLITE_OK.
 */
 SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
-  if( pFrom->pTab && pFrom->zIndex ){
+  if( pFrom->pTab && pFrom->fg.isIndexedBy ){
     Table *pTab = pFrom->pTab;
-    char *zIndex = pFrom->zIndex;
+    char *zIndexedBy = pFrom->u1.zIndexedBy;
     Index *pIdx;
     for(pIdx=pTab->pIndex; 
-        pIdx && sqlite3StrICmp(pIdx->zName, zIndex); 
+        pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); 
         pIdx=pIdx->pNext
     );
     if( !pIdx ){
-      sqlite3ErrorMsg(pParse, "no such index: %s", zIndex, 0);
+      sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
       pParse->checkSchema = 1;
       return SQLITE_ERROR;
     }
-    pFrom->pIndex = pIdx;
+    pFrom->pIBIndex = pIdx;
   }
   return SQLITE_OK;
 }
+/*
+** Detect compound SELECT statements that use an ORDER BY clause with 
+** an alternative collating sequence.
+**
+**    SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...
+**
+** These are rewritten as a subquery:
+**
+**    SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)
+**     ORDER BY ... COLLATE ...
+**
+** This transformation is necessary because the multiSelectOrderBy() routine
+** above that generates the code for a compound SELECT with an ORDER BY clause
+** uses a merge algorithm that requires the same collating sequence on the
+** result columns as on the ORDER BY clause.  See ticket
+** http://www.sqlite.org/src/info/6709574d2a
+**
+** This transformation is only needed for EXCEPT, INTERSECT, and UNION.
+** The UNION ALL operator works fine with multiSelectOrderBy() even when
+** there are COLLATE terms in the ORDER BY.
+*/
+static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
+  int i;
+  Select *pNew;
+  Select *pX;
+  sqlite3 *db;
+  struct ExprList_item *a;
+  SrcList *pNewSrc;
+  Parse *pParse;
+  Token dummy;
+
+  if( p->pPrior==0 ) return WRC_Continue;
+  if( p->pOrderBy==0 ) return WRC_Continue;
+  for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
+  if( pX==0 ) return WRC_Continue;
+  a = p->pOrderBy->a;
+  for(i=p->pOrderBy->nExpr-1; i>=0; i--){
+    if( a[i].pExpr->flags & EP_Collate ) break;
+  }
+  if( i<0 ) return WRC_Continue;
+
+  /* If we reach this point, that means the transformation is required. */
+
+  pParse = pWalker->pParse;
+  db = pParse->db;
+  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
+  if( pNew==0 ) return WRC_Abort;
+  memset(&dummy, 0, sizeof(dummy));
+  pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);
+  if( pNewSrc==0 ) return WRC_Abort;
+  *pNew = *p;
+  p->pSrc = pNewSrc;
+  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));
+  p->op = TK_SELECT;
+  p->pWhere = 0;
+  pNew->pGroupBy = 0;
+  pNew->pHaving = 0;
+  pNew->pOrderBy = 0;
+  p->pPrior = 0;
+  p->pNext = 0;
+  p->pWith = 0;
+  p->selFlags &= ~SF_Compound;
+  assert( (p->selFlags & SF_Converted)==0 );
+  p->selFlags |= SF_Converted;
+  assert( pNew->pPrior!=0 );
+  pNew->pPrior->pNext = pNew;
+  pNew->pLimit = 0;
+  pNew->pOffset = 0;
+  return WRC_Continue;
+}
+
+/*
+** Check to see if the FROM clause term pFrom has table-valued function
+** arguments.  If it does, leave an error message in pParse and return
+** non-zero, since pFrom is not allowed to be a table-valued function.
+*/
+static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){
+  if( pFrom->fg.isTabFunc ){
+    sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);
+    return 1;
+  }
+  return 0;
+}
+
+#ifndef SQLITE_OMIT_CTE
+/*
+** Argument pWith (which may be NULL) points to a linked list of nested 
+** WITH contexts, from inner to outermost. If the table identified by 
+** FROM clause element pItem is really a common-table-expression (CTE) 
+** then return a pointer to the CTE definition for that table. Otherwise
+** return NULL.
+**
+** If a non-NULL value is returned, set *ppContext to point to the With
+** object that the returned CTE belongs to.
+*/
+static struct Cte *searchWith(
+  With *pWith,                    /* Current innermost WITH clause */
+  struct SrcList_item *pItem,     /* FROM clause element to resolve */
+  With **ppContext                /* OUT: WITH clause return value belongs to */
+){
+  const char *zName;
+  if( pItem->zDatabase==0 && (zName = pItem->zName)!=0 ){
+    With *p;
+    for(p=pWith; p; p=p->pOuter){
+      int i;
+      for(i=0; i<p->nCte; i++){
+        if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){
+          *ppContext = p;
+          return &p->a[i];
+        }
+      }
+    }
+  }
+  return 0;
+}
+
+/* The code generator maintains a stack of active WITH clauses
+** with the inner-most WITH clause being at the top of the stack.
+**
+** This routine pushes the WITH clause passed as the second argument
+** onto the top of the stack. If argument bFree is true, then this
+** WITH clause will never be popped from the stack. In this case it
+** should be freed along with the Parse object. In other cases, when
+** bFree==0, the With object will be freed along with the SELECT 
+** statement with which it is associated.
+*/
+SQLITE_PRIVATE void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){
+  assert( bFree==0 || (pParse->pWith==0 && pParse->pWithToFree==0) );
+  if( pWith ){
+    assert( pParse->pWith!=pWith );
+    pWith->pOuter = pParse->pWith;
+    pParse->pWith = pWith;
+    if( bFree ) pParse->pWithToFree = pWith;
+  }
+}
+
+/*
+** This function checks if argument pFrom refers to a CTE declared by 
+** a WITH clause on the stack currently maintained by the parser. And,
+** if currently processing a CTE expression, if it is a recursive
+** reference to the current CTE.
+**
+** If pFrom falls into either of the two categories above, pFrom->pTab
+** and other fields are populated accordingly. The caller should check
+** (pFrom->pTab!=0) to determine whether or not a successful match
+** was found.
+**
+** Whether or not a match is found, SQLITE_OK is returned if no error
+** occurs. If an error does occur, an error message is stored in the
+** parser and some error code other than SQLITE_OK returned.
+*/
+static int withExpand(
+  Walker *pWalker, 
+  struct SrcList_item *pFrom
+){
+  Parse *pParse = pWalker->pParse;
+  sqlite3 *db = pParse->db;
+  struct Cte *pCte;               /* Matched CTE (or NULL if no match) */
+  With *pWith;                    /* WITH clause that pCte belongs to */
+
+  assert( pFrom->pTab==0 );
+
+  pCte = searchWith(pParse->pWith, pFrom, &pWith);
+  if( pCte ){
+    Table *pTab;
+    ExprList *pEList;
+    Select *pSel;
+    Select *pLeft;                /* Left-most SELECT statement */
+    int bMayRecursive;            /* True if compound joined by UNION [ALL] */
+    With *pSavedWith;             /* Initial value of pParse->pWith */
+
+    /* If pCte->zCteErr is non-NULL at this point, then this is an illegal
+    ** recursive reference to CTE pCte. Leave an error in pParse and return
+    ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
+    ** In this case, proceed.  */
+    if( pCte->zCteErr ){
+      sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
+      return SQLITE_ERROR;
+    }
+    if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;
+
+    assert( pFrom->pTab==0 );
+    pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
+    if( pTab==0 ) return WRC_Abort;
+    pTab->nRef = 1;
+    pTab->zName = sqlite3DbStrDup(db, pCte->zName);
+    pTab->iPKey = -1;
+    pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
+    pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
+    pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
+    if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
+    assert( pFrom->pSelect );
+
+    /* Check if this is a recursive CTE. */
+    pSel = pFrom->pSelect;
+    bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
+    if( bMayRecursive ){
+      int i;
+      SrcList *pSrc = pFrom->pSelect->pSrc;
+      for(i=0; i<pSrc->nSrc; i++){
+        struct SrcList_item *pItem = &pSrc->a[i];
+        if( pItem->zDatabase==0 
+         && pItem->zName!=0 
+         && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
+          ){
+          pItem->pTab = pTab;
+          pItem->fg.isRecursive = 1;
+          pTab->nRef++;
+          pSel->selFlags |= SF_Recursive;
+        }
+      }
+    }
+
+    /* Only one recursive reference is permitted. */ 
+    if( pTab->nRef>2 ){
+      sqlite3ErrorMsg(
+          pParse, "multiple references to recursive table: %s", pCte->zName
+      );
+      return SQLITE_ERROR;
+    }
+    assert( pTab->nRef==1 || ((pSel->selFlags&SF_Recursive) && pTab->nRef==2 ));
+
+    pCte->zCteErr = "circular reference: %s";
+    pSavedWith = pParse->pWith;
+    pParse->pWith = pWith;
+    sqlite3WalkSelect(pWalker, bMayRecursive ? pSel->pPrior : pSel);
+    pParse->pWith = pWith;
+
+    for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);
+    pEList = pLeft->pEList;
+    if( pCte->pCols ){
+      if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){
+        sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",
+            pCte->zName, pEList->nExpr, pCte->pCols->nExpr
+        );
+        pParse->pWith = pSavedWith;
+        return SQLITE_ERROR;
+      }
+      pEList = pCte->pCols;
+    }
+
+    sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
+    if( bMayRecursive ){
+      if( pSel->selFlags & SF_Recursive ){
+        pCte->zCteErr = "multiple recursive references: %s";
+      }else{
+        pCte->zCteErr = "recursive reference in a subquery: %s";
+      }
+      sqlite3WalkSelect(pWalker, pSel);
+    }
+    pCte->zCteErr = 0;
+    pParse->pWith = pSavedWith;
+  }
+
+  return SQLITE_OK;
+}
+#endif
+
+#ifndef SQLITE_OMIT_CTE
+/*
+** If the SELECT passed as the second argument has an associated WITH 
+** clause, pop it from the stack stored as part of the Parse object.
+**
+** This function is used as the xSelectCallback2() callback by
+** sqlite3SelectExpand() when walking a SELECT tree to resolve table
+** names and other FROM clause elements. 
+*/
+static void selectPopWith(Walker *pWalker, Select *p){
+  Parse *pParse = pWalker->pParse;
+  With *pWith = findRightmost(p)->pWith;
+  if( pWith!=0 ){
+    assert( pParse->pWith==pWith );
+    pParse->pWith = pWith->pOuter;
+  }
+}
+#else
+#define selectPopWith 0
+#endif
 
 /*
 ** This routine is a Walker callback for "expanding" a SELECT statement.
@@ -95867,10 +117717,10 @@ SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pF
 **         fill pTabList->a[].pSelect with a copy of the SELECT statement
 **         that implements the view.  A copy is made of the view's SELECT
 **         statement so that we can freely modify or delete that statement
-**         without worrying about messing up the presistent representation
+**         without worrying about messing up the persistent representation
 **         of the view.
 **
-**    (3)  Add terms to the WHERE clause to accomodate the NATURAL keyword
+**    (3)  Add terms to the WHERE clause to accommodate the NATURAL keyword
 **         on joins and the ON and USING clause of joins.
 **
 **    (4)  Scan the list of columns in the result set (pEList) looking
@@ -95886,16 +117736,21 @@ static int selectExpander(Walker *pWalker, Select *p){
   ExprList *pEList;
   struct SrcList_item *pFrom;
   sqlite3 *db = pParse->db;
+  Expr *pE, *pRight, *pExpr;
+  u16 selFlags = p->selFlags;
 
+  p->selFlags |= SF_Expanded;
   if( db->mallocFailed  ){
     return WRC_Abort;
   }
-  if( NEVER(p->pSrc==0) || (p->selFlags & SF_Expanded)!=0 ){
+  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
     return WRC_Prune;
   }
-  p->selFlags |= SF_Expanded;
   pTabList = p->pSrc;
   pEList = p->pEList;
+  if( pWalker->xSelectCallback2==selectPopWith ){
+    sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
+  }
 
   /* Make sure cursor numbers have been assigned to all entries in
   ** the FROM clause of the SELECT statement.
@@ -95908,43 +117763,56 @@ static int selectExpander(Walker *pWalker, Select *p){
   */
   for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
     Table *pTab;
-    if( pFrom->pTab!=0 ){
-      /* This statement has already been prepared.  There is no need
-      ** to go further. */
-      assert( i==0 );
-      return WRC_Prune;
-    }
+    assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
+    if( pFrom->fg.isRecursive ) continue;
+    assert( pFrom->pTab==0 );
+#ifndef SQLITE_OMIT_CTE
+    if( withExpand(pWalker, pFrom) ) return WRC_Abort;
+    if( pFrom->pTab ) {} else
+#endif
     if( pFrom->zName==0 ){
 #ifndef SQLITE_OMIT_SUBQUERY
       Select *pSel = pFrom->pSelect;
       /* A sub-query in the FROM clause of a SELECT */
       assert( pSel!=0 );
       assert( pFrom->pTab==0 );
-      sqlite3WalkSelect(pWalker, pSel);
+      if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
       pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
       if( pTab==0 ) return WRC_Abort;
       pTab->nRef = 1;
-      pTab->zName = sqlite3MPrintf(db, "sqlite_subquery_%p_", (void*)pTab);
+      pTab->zName = sqlite3MPrintf(db, "sqlite_sq_%p", (void*)pTab);
       while( pSel->pPrior ){ pSel = pSel->pPrior; }
-      selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol);
+      sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
       pTab->iPKey = -1;
-      pTab->nRowEst = 1000000;
+      pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
       pTab->tabFlags |= TF_Ephemeral;
 #endif
     }else{
       /* An ordinary table or view name in the FROM clause */
       assert( pFrom->pTab==0 );
-      pFrom->pTab = pTab = 
-        sqlite3LocateTable(pParse,0,pFrom->zName,pFrom->zDatabase);
+      pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
       if( pTab==0 ) return WRC_Abort;
+      if( pTab->nRef==0xffff ){
+        sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
+           pTab->zName);
+        pFrom->pTab = 0;
+        return WRC_Abort;
+      }
       pTab->nRef++;
+      if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
+        return WRC_Abort;
+      }
 #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
-      if( pTab->pSelect || IsVirtual(pTab) ){
-        /* We reach here if the named table is a really a view */
+      if( IsVirtual(pTab) || pTab->pSelect ){
+        i16 nCol;
         if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
         assert( pFrom->pSelect==0 );
         pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
+        sqlite3SelectSetName(pFrom->pSelect, pTab->zName);
+        nCol = pTab->nCol;
+        pTab->nCol = -1;
         sqlite3WalkSelect(pWalker, pFrom->pSelect);
+        pTab->nCol = nCol;
       }
 #endif
     }
@@ -95964,19 +117832,20 @@ static int selectExpander(Walker *pWalker, Select *p){
   /* For every "*" that occurs in the column list, insert the names of
   ** all columns in all tables.  And for every TABLE.* insert the names
   ** of all columns in TABLE.  The parser inserted a special expression
-  ** with the TK_ALL operator for each "*" that it found in the column list.
-  ** The following code just has to locate the TK_ALL expressions and expand
-  ** each one to the list of all columns in all tables.
+  ** with the TK_ASTERISK operator for each "*" that it found in the column
+  ** list.  The following code just has to locate the TK_ASTERISK
+  ** expressions and expand each one to the list of all columns in
+  ** all tables.
   **
   ** The first loop just checks to see if there are any "*" operators
   ** that need expanding.
   */
   for(k=0; k<pEList->nExpr; k++){
-    Expr *pE = pEList->a[k].pExpr;
-    if( pE->op==TK_ALL ) break;
+    pE = pEList->a[k].pExpr;
+    if( pE->op==TK_ASTERISK ) break;
     assert( pE->op!=TK_DOT || pE->pRight!=0 );
     assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
-    if( pE->op==TK_DOT && pE->pRight->op==TK_ALL ) break;
+    if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;
   }
   if( k<pEList->nExpr ){
     /*
@@ -95991,9 +117860,12 @@ static int selectExpander(Walker *pWalker, Select *p){
                       && (flags & SQLITE_ShortColNames)==0;
 
     for(k=0; k<pEList->nExpr; k++){
-      Expr *pE = a[k].pExpr;
-      assert( pE->op!=TK_DOT || pE->pRight!=0 );
-      if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pE->pRight->op!=TK_ALL) ){
+      pE = a[k].pExpr;
+      pRight = pE->pRight;
+      assert( pE->op!=TK_DOT || pRight!=0 );
+      if( pE->op!=TK_ASTERISK
+       && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
+      ){
         /* This particular expression does not need to be expanded.
         */
         pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
@@ -96008,43 +117880,56 @@ static int selectExpander(Walker *pWalker, Select *p){
         /* This expression is a "*" or a "TABLE.*" and needs to be
         ** expanded. */
         int tableSeen = 0;      /* Set to 1 when TABLE matches */
-        char *zTName;            /* text of name of TABLE */
+        char *zTName = 0;       /* text of name of TABLE */
         if( pE->op==TK_DOT ){
           assert( pE->pLeft!=0 );
           assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );
           zTName = pE->pLeft->u.zToken;
-        }else{
-          zTName = 0;
         }
         for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
           Table *pTab = pFrom->pTab;
+          Select *pSub = pFrom->pSelect;
           char *zTabName = pFrom->zAlias;
+          const char *zSchemaName = 0;
+          int iDb;
           if( zTabName==0 ){
             zTabName = pTab->zName;
           }
           if( db->mallocFailed ) break;
-          if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
-            continue;
+          if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
+            pSub = 0;
+            if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
+              continue;
+            }
+            iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+            zSchemaName = iDb>=0 ? db->aDb[iDb].zName : "*";
           }
-          tableSeen = 1;
           for(j=0; j<pTab->nCol; j++){
-            Expr *pExpr, *pRight;
             char *zName = pTab->aCol[j].zName;
             char *zColname;  /* The computed column name */
             char *zToFree;   /* Malloced string that needs to be freed */
             Token sColname;  /* Computed column name as a token */
 
-            /* If a column is marked as 'hidden' (currently only possible
-            ** for virtual tables), do not include it in the expanded
-            ** result-set list.
+            assert( zName );
+            if( zTName && pSub
+             && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0
+            ){
+              continue;
+            }
+
+            /* If a column is marked as 'hidden', omit it from the expanded
+            ** result-set list unless the SELECT has the SF_IncludeHidden
+            ** bit set.
             */
-            if( IsHiddenColumn(&pTab->aCol[j]) ){
-              assert(IsVirtual(pTab));
+            if( (p->selFlags & SF_IncludeHidden)==0
+             && IsHiddenColumn(&pTab->aCol[j]) 
+            ){
               continue;
             }
+            tableSeen = 1;
 
             if( i>0 && zTName==0 ){
-              if( (pFrom->jointype & JT_NATURAL)!=0
+              if( (pFrom->fg.jointype & JT_NATURAL)!=0
                 && tableAndColumnIndex(pTabList, i, zName, 0, 0)
               ){
                 /* In a NATURAL join, omit the join columns from the 
@@ -96064,6 +117949,10 @@ static int selectExpander(Walker *pWalker, Select *p){
               Expr *pLeft;
               pLeft = sqlite3Expr(db, TK_ID, zTabName);
               pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+              if( zSchemaName ){
+                pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
+                pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr, 0);
+              }
               if( longNames ){
                 zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
                 zToFree = zColname;
@@ -96072,9 +117961,20 @@ static int selectExpander(Walker *pWalker, Select *p){
               pExpr = pRight;
             }
             pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
-            sColname.z = zColname;
-            sColname.n = sqlite3Strlen30(zColname);
+            sqlite3TokenInit(&sColname, zColname);
             sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
+            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
+              struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
+              if( pSub ){
+                pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);
+                testcase( pX->zSpan==0 );
+              }else{
+                pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s",
+                                           zSchemaName, zTabName, zColname);
+                testcase( pX->zSpan==0 );
+              }
+              pX->bSpanIsTab = 1;
+            }
             sqlite3DbFree(db, zToFree);
           }
         }
@@ -96093,6 +117993,7 @@ static int selectExpander(Walker *pWalker, Select *p){
 #if SQLITE_MAX_COLUMN
   if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many columns in result set");
+    return WRC_Abort;
   }
 #endif
   return WRC_Continue;
@@ -96107,7 +118008,7 @@ static int selectExpander(Walker *pWalker, Select *p){
 ** Walker.xSelectCallback is set to do something useful for every 
 ** subquery in the parser tree.
 */
-static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
+SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
   UNUSED_PARAMETER2(NotUsed, NotUsed2);
   return WRC_Continue;
 }
@@ -96127,9 +118028,17 @@ static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
 */
 static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
   Walker w;
-  w.xSelectCallback = selectExpander;
-  w.xExprCallback = exprWalkNoop;
+  memset(&w, 0, sizeof(w));
+  w.xExprCallback = sqlite3ExprWalkNoop;
   w.pParse = pParse;
+  if( pParse->hasCompound ){
+    w.xSelectCallback = convertCompoundSelectToSubquery;
+    sqlite3WalkSelect(&w, pSelect);
+  }
+  w.xSelectCallback = selectExpander;
+  if( (pSelect->selFlags & SF_MultiValue)==0 ){
+    w.xSelectCallback2 = selectPopWith;
+  }
   sqlite3WalkSelect(&w, pSelect);
 }
 
@@ -96148,29 +118057,29 @@ static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
 ** at that point because identifiers had not yet been resolved.  This
 ** routine is called after identifier resolution.
 */
-static int selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
+static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
   Parse *pParse;
   int i;
   SrcList *pTabList;
   struct SrcList_item *pFrom;
 
   assert( p->selFlags & SF_Resolved );
-  if( (p->selFlags & SF_HasTypeInfo)==0 ){
-    p->selFlags |= SF_HasTypeInfo;
-    pParse = pWalker->pParse;
-    pTabList = p->pSrc;
-    for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-      Table *pTab = pFrom->pTab;
-      if( ALWAYS(pTab!=0) && (pTab->tabFlags & TF_Ephemeral)!=0 ){
-        /* A sub-query in the FROM clause of a SELECT */
-        Select *pSel = pFrom->pSelect;
-        assert( pSel );
+  assert( (p->selFlags & SF_HasTypeInfo)==0 );
+  p->selFlags |= SF_HasTypeInfo;
+  pParse = pWalker->pParse;
+  pTabList = p->pSrc;
+  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
+    Table *pTab = pFrom->pTab;
+    assert( pTab!=0 );
+    if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
+      /* A sub-query in the FROM clause of a SELECT */
+      Select *pSel = pFrom->pSelect;
+      if( pSel ){
         while( pSel->pPrior ) pSel = pSel->pPrior;
-        selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSel);
+        sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSel);
       }
     }
   }
-  return WRC_Continue;
 }
 #endif
 
@@ -96185,8 +118094,9 @@ static int selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
 static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
 #ifndef SQLITE_OMIT_SUBQUERY
   Walker w;
-  w.xSelectCallback = selectAddSubqueryTypeInfo;
-  w.xExprCallback = exprWalkNoop;
+  memset(&w, 0, sizeof(w));
+  w.xSelectCallback2 = selectAddSubqueryTypeInfo;
+  w.xExprCallback = sqlite3ExprWalkNoop;
   w.pParse = pParse;
   sqlite3WalkSelect(&w, pSelect);
 #endif
@@ -96194,7 +118104,7 @@ static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
 
 
 /*
-** This routine sets of a SELECT statement for processing.  The
+** This routine sets up a SELECT statement for processing.  The
 ** following is accomplished:
 **
 **     *  VDBE Cursor numbers are assigned to all FROM-clause terms.
@@ -96213,6 +118123,7 @@ SQLITE_PRIVATE void sqlite3SelectPrep(
   sqlite3 *db;
   if( NEVER(p==0) ) return;
   db = pParse->db;
+  if( db->mallocFailed ) return;
   if( p->selFlags & SF_HasTypeInfo ) return;
   sqlite3SelectExpand(pParse, p);
   if( pParse->nErr || db->mallocFailed ) return;
@@ -96226,20 +118137,30 @@ SQLITE_PRIVATE void sqlite3SelectPrep(
 **
 ** The aggregate accumulator is a set of memory cells that hold
 ** intermediate results while calculating an aggregate.  This
-** routine simply stores NULLs in all of those memory cells.
+** routine generates code that stores NULLs in all of those memory
+** cells.
 */
 static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
   Vdbe *v = pParse->pVdbe;
   int i;
   struct AggInfo_func *pFunc;
-  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
-    return;
-  }
+  int nReg = pAggInfo->nFunc + pAggInfo->nColumn;
+  if( nReg==0 ) return;
+#ifdef SQLITE_DEBUG
+  /* Verify that all AggInfo registers are within the range specified by
+  ** AggInfo.mnReg..AggInfo.mxReg */
+  assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );
   for(i=0; i<pAggInfo->nColumn; i++){
-    sqlite3VdbeAddOp2(v, OP_Null, 0, pAggInfo->aCol[i].iMem);
+    assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg
+         && pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );
+  }
+  for(i=0; i<pAggInfo->nFunc; i++){
+    assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
+         && pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
   }
+#endif
+  sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
   for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
-    sqlite3VdbeAddOp2(v, OP_Null, 0, pFunc->iMem);
     if( pFunc->iDistinct>=0 ){
       Expr *pE = pFunc->pExpr;
       assert( !ExprHasProperty(pE, EP_xIsSelect) );
@@ -96248,9 +118169,9 @@ static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
            "argument");
         pFunc->iDistinct = -1;
       }else{
-        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList);
+        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList, 0, 0);
         sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
-                          (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+                          (char*)pKeyInfo, P4_KEYINFO);
       }
     }
   }
@@ -96279,11 +118200,12 @@ static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
 static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
   Vdbe *v = pParse->pVdbe;
   int i;
+  int regHit = 0;
+  int addrHitTest = 0;
   struct AggInfo_func *pF;
   struct AggInfo_col *pC;
 
   pAggInfo->directMode = 1;
-  sqlite3ExprCacheClear(pParse);
   for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
     int nArg;
     int addrNext = 0;
@@ -96293,17 +118215,18 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
     if( pList ){
       nArg = pList->nExpr;
       regAgg = sqlite3GetTempRange(pParse, nArg);
-      sqlite3ExprCodeExprList(pParse, pList, regAgg, 1);
+      sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);
     }else{
       nArg = 0;
       regAgg = 0;
     }
     if( pF->iDistinct>=0 ){
       addrNext = sqlite3VdbeMakeLabel(v);
-      assert( nArg==1 );
+      testcase( nArg==0 );  /* Error condition */
+      testcase( nArg>1 );   /* Also an error */
       codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
     }
-    if( pF->pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
+    if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
       CollSeq *pColl = 0;
       struct ExprList_item *pItem;
       int j;
@@ -96314,9 +118237,10 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
       if( !pColl ){
         pColl = pParse->db->pDfltColl;
       }
-      sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
+      if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;
+      sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);
     }
-    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
+    sqlite3VdbeAddOp4(v, OP_AggStep0, 0, regAgg, pF->iMem,
                       (void*)pF->pFunc, P4_FUNCDEF);
     sqlite3VdbeChangeP5(v, (u8)nArg);
     sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
@@ -96337,12 +118261,18 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
   ** Another solution would be to change the OP_SCopy used to copy cached
   ** values to an OP_Copy.
   */
+  if( regHit ){
+    addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
+  }
   sqlite3ExprCacheClear(pParse);
   for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
     sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
   }
   pAggInfo->directMode = 0;
   sqlite3ExprCacheClear(pParse);
+  if( addrHitTest ){
+    sqlite3VdbeJumpHere(v, addrHitTest);
+  }
 }
 
 /*
@@ -96356,11 +118286,11 @@ static void explainSimpleCount(
   Index *pIdx                     /* Index used to optimize scan, or NULL */
 ){
   if( pParse->explain==2 ){
-    char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s %s%s(~%d rows)",
-        pTab->zName, 
-        pIdx ? "USING COVERING INDEX " : "",
-        pIdx ? pIdx->zName : "",
-        pTab->nRowEst
+    int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));
+    char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s%s%s",
+        pTab->zName,
+        bCover ? " USING COVERING INDEX " : "",
+        bCover ? pIdx->zName : ""
     );
     sqlite3VdbeAddOp4(
         pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC
@@ -96374,49 +118304,8 @@ static void explainSimpleCount(
 /*
 ** Generate code for the SELECT statement given in the p argument.  
 **
-** The results are distributed in various ways depending on the
-** contents of the SelectDest structure pointed to by argument pDest
-** as follows:
-**
-**     pDest->eDest    Result
-**     ------------    -------------------------------------------
-**     SRT_Output      Generate a row of output (using the OP_ResultRow
-**                     opcode) for each row in the result set.
-**
-**     SRT_Mem         Only valid if the result is a single column.
-**                     Store the first column of the first result row
-**                     in register pDest->iParm then abandon the rest
-**                     of the query.  This destination implies "LIMIT 1".
-**
-**     SRT_Set         The result must be a single column.  Store each
-**                     row of result as the key in table pDest->iParm. 
-**                     Apply the affinity pDest->affinity before storing
-**                     results.  Used to implement "IN (SELECT ...)".
-**
-**     SRT_Union       Store results as a key in a temporary table pDest->iParm.
-**
-**     SRT_Except      Remove results from the temporary table pDest->iParm.
-**
-**     SRT_Table       Store results in temporary table pDest->iParm.
-**                     This is like SRT_EphemTab except that the table
-**                     is assumed to already be open.
-**
-**     SRT_EphemTab    Create an temporary table pDest->iParm and store
-**                     the result there. The cursor is left open after
-**                     returning.  This is like SRT_Table except that
-**                     this destination uses OP_OpenEphemeral to create
-**                     the table first.
-**
-**     SRT_Coroutine   Generate a co-routine that returns a new row of
-**                     results each time it is invoked.  The entry point
-**                     of the co-routine is stored in register pDest->iParm.
-**
-**     SRT_Exists      Store a 1 in memory cell pDest->iParm if the result
-**                     set is not empty.
-**
-**     SRT_Discard     Throw the results away.  This is used by SELECT
-**                     statements within triggers whose only purpose is
-**                     the side-effects of functions.
+** The results are returned according to the SelectDest structure.
+** See comments in sqliteInt.h for further information.
 **
 ** This routine returns the number of errors.  If any errors are
 ** encountered, then an appropriate error message is left in
@@ -96434,17 +118323,14 @@ SQLITE_PRIVATE int sqlite3Select(
   WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */
   Vdbe *v;               /* The virtual machine under construction */
   int isAgg;             /* True for select lists like "count(*)" */
-  ExprList *pEList;      /* List of columns to extract. */
+  ExprList *pEList = 0;  /* List of columns to extract. */
   SrcList *pTabList;     /* List of tables to select from */
   Expr *pWhere;          /* The WHERE clause.  May be NULL */
-  ExprList *pOrderBy;    /* The ORDER BY clause.  May be NULL */
   ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */
   Expr *pHaving;         /* The HAVING clause.  May be NULL */
-  int isDistinct;        /* True if the DISTINCT keyword is present */
-  int distinct;          /* Table to use for the distinct set */
   int rc = 1;            /* Value to return from this function */
-  int addrSortIndex;     /* Address of an OP_OpenEphemeral instruction */
-  int addrDistinctIndex; /* Address of an OP_OpenEphemeral instruction */
+  DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
+  SortCtx sSort;         /* Info on how to code the ORDER BY clause */
   AggInfo sAggInfo;      /* Information used by aggregate queries */
   int iEnd;              /* Address of the end of the query */
   sqlite3 *db;           /* The database connection */
@@ -96460,10 +118346,23 @@ SQLITE_PRIVATE int sqlite3Select(
   }
   if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
   memset(&sAggInfo, 0, sizeof(sAggInfo));
+#if SELECTTRACE_ENABLED
+  pParse->nSelectIndent++;
+  SELECTTRACE(1,pParse,p, ("begin processing:\n"));
+  if( sqlite3SelectTrace & 0x100 ){
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
 
+  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );
+  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
+  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
+  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
   if( IgnorableOrderby(pDest) ){
     assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
-           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard);
+           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
+           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
+           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
     /* If ORDER BY makes no difference in the output then neither does
     ** DISTINCT so it can be removed too. */
     sqlite3ExprListDelete(db, p->pOrderBy);
@@ -96471,46 +118370,110 @@ SQLITE_PRIVATE int sqlite3Select(
     p->selFlags &= ~SF_Distinct;
   }
   sqlite3SelectPrep(pParse, p, 0);
-  pOrderBy = p->pOrderBy;
+  memset(&sSort, 0, sizeof(sSort));
+  sSort.pOrderBy = p->pOrderBy;
   pTabList = p->pSrc;
-  pEList = p->pEList;
   if( pParse->nErr || db->mallocFailed ){
     goto select_end;
   }
+  assert( p->pEList!=0 );
   isAgg = (p->selFlags & SF_Aggregate)!=0;
-  assert( pEList!=0 );
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x100 ){
+    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
 
-  /* Begin generating code.
-  */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ) goto select_end;
 
   /* If writing to memory or generating a set
   ** only a single column may be output.
   */
 #ifndef SQLITE_OMIT_SUBQUERY
-  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
+  if( checkForMultiColumnSelectError(pParse, pDest, p->pEList->nExpr) ){
     goto select_end;
   }
 #endif
 
-  /* Generate code for all sub-queries in the FROM clause
+  /* Try to flatten subqueries in the FROM clause up into the main query
   */
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
   for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
     struct SrcList_item *pItem = &pTabList->a[i];
-    SelectDest dest;
     Select *pSub = pItem->pSelect;
     int isAggSub;
+    Table *pTab = pItem->pTab;
+    if( pSub==0 ) continue;
+
+    /* Catch mismatch in the declared columns of a view and the number of
+    ** columns in the SELECT on the RHS */
+    if( pTab->nCol!=pSub->pEList->nExpr ){
+      sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
+                      pTab->nCol, pTab->zName, pSub->pEList->nExpr);
+      goto select_end;
+    }
 
+    isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
+    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
+      /* This subquery can be absorbed into its parent. */
+      if( isAggSub ){
+        isAgg = 1;
+        p->selFlags |= SF_Aggregate;
+      }
+      i = -1;
+    }
+    pTabList = p->pSrc;
+    if( db->mallocFailed ) goto select_end;
+    if( !IgnorableOrderby(pDest) ){
+      sSort.pOrderBy = p->pOrderBy;
+    }
+  }
+#endif
+
+  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
+  ** does not already exist */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto select_end;
+
+#ifndef SQLITE_OMIT_COMPOUND_SELECT
+  /* Handle compound SELECT statements using the separate multiSelect()
+  ** procedure.
+  */
+  if( p->pPrior ){
+    rc = multiSelect(pParse, p, pDest);
+    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
+#if SELECTTRACE_ENABLED
+    SELECTTRACE(1,pParse,p,("end compound-select processing\n"));
+    pParse->nSelectIndent--;
+#endif
+    return rc;
+  }
+#endif
+
+  /* Generate code for all sub-queries in the FROM clause
+  */
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+  for(i=0; i<pTabList->nSrc; i++){
+    struct SrcList_item *pItem = &pTabList->a[i];
+    SelectDest dest;
+    Select *pSub = pItem->pSelect;
     if( pSub==0 ) continue;
+
+    /* Sometimes the code for a subquery will be generated more than
+    ** once, if the subquery is part of the WHERE clause in a LEFT JOIN,
+    ** for example.  In that case, do not regenerate the code to manifest
+    ** a view or the co-routine to implement a view.  The first instance
+    ** is sufficient, though the subroutine to manifest the view does need
+    ** to be invoked again. */
     if( pItem->addrFillSub ){
-      sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
+      if( pItem->fg.viaCoroutine==0 ){
+        sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
+      }
       continue;
     }
 
     /* Increment Parse.nHeight by the height of the largest expression
-    ** tree refered to by this, the parent select. The child select
+    ** tree referred to by this, the parent select. The child select
     ** may contain expression trees of at most
     ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
     ** more conservative than necessary, but much easier than enforcing
@@ -96518,14 +118481,57 @@ SQLITE_PRIVATE int sqlite3Select(
     */
     pParse->nHeight += sqlite3SelectExprHeight(p);
 
-    isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
-    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
-      /* This subquery can be absorbed into its parent. */
-      if( isAggSub ){
-        isAgg = 1;
-        p->selFlags |= SF_Aggregate;
+    /* Make copies of constant WHERE-clause terms in the outer query down
+    ** inside the subquery.  This can help the subquery to run more efficiently.
+    */
+    if( (pItem->fg.jointype & JT_OUTER)==0
+     && pushDownWhereTerms(db, pSub, p->pWhere, pItem->iCursor)
+    ){
+#if SELECTTRACE_ENABLED
+      if( sqlite3SelectTrace & 0x100 ){
+        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
+        sqlite3TreeViewSelect(0, p, 0);
       }
-      i = -1;
+#endif
+    }
+
+    /* Generate code to implement the subquery
+    **
+    ** The subquery is implemented as a co-routine if all of these are true:
+    **   (1)  The subquery is guaranteed to be the outer loop (so that it
+    **        does not need to be computed more than once)
+    **   (2)  The ALL keyword after SELECT is omitted.  (Applications are
+    **        allowed to say "SELECT ALL" instead of just "SELECT" to disable
+    **        the use of co-routines.)
+    **   (3)  Co-routines are not disabled using sqlite3_test_control()
+    **        with SQLITE_TESTCTRL_OPTIMIZATIONS.
+    **
+    ** TODO: Are there other reasons beside (1) to use a co-routine
+    ** implementation?
+    */
+    if( i==0
+     && (pTabList->nSrc==1
+            || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */
+     && (p->selFlags & SF_All)==0                                   /* (2) */
+     && OptimizationEnabled(db, SQLITE_SubqCoroutine)               /* (3) */
+    ){
+      /* Implement a co-routine that will return a single row of the result
+      ** set on each invocation.
+      */
+      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
+      pItem->regReturn = ++pParse->nMem;
+      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
+      VdbeComment((v, "%s", pItem->pTab->zName));
+      pItem->addrFillSub = addrTop;
+      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
+      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
+      sqlite3Select(pParse, pSub, &dest);
+      pItem->pTab->nRowLogEst = pSub->nSelectRow;
+      pItem->fg.viaCoroutine = 1;
+      pItem->regResult = dest.iSdst;
+      sqlite3VdbeEndCoroutine(v, pItem->regReturn);
+      sqlite3VdbeJumpHere(v, addrTop-1);
+      sqlite3ClearTempRegCache(pParse);
     }else{
       /* Generate a subroutine that will fill an ephemeral table with
       ** the content of this subquery.  pItem->addrFillSub will point
@@ -96539,77 +118545,45 @@ SQLITE_PRIVATE int sqlite3Select(
       pItem->regReturn = ++pParse->nMem;
       topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
       pItem->addrFillSub = topAddr+1;
-      VdbeNoopComment((v, "materialize %s", pItem->pTab->zName));
-      if( pItem->isCorrelated==0 && pParse->pTriggerTab==0 ){
-        /* If the subquery is no correlated and if we are not inside of
+      if( pItem->fg.isCorrelated==0 ){
+        /* If the subquery is not correlated and if we are not inside of
         ** a trigger, then we only need to compute the value of the subquery
         ** once. */
-        int regOnce = ++pParse->nMem;
-        onceAddr = sqlite3VdbeAddOp1(v, OP_Once, regOnce);
+        onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+        VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
+      }else{
+        VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
       }
       sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
       explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
       sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow;
+      pItem->pTab->nRowLogEst = pSub->nSelectRow;
       if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
       retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
       VdbeComment((v, "end %s", pItem->pTab->zName));
       sqlite3VdbeChangeP1(v, topAddr, retAddr);
-
-    }
-    if( /*pParse->nErr ||*/ db->mallocFailed ){
-      goto select_end;
+      sqlite3ClearTempRegCache(pParse);
     }
+    if( db->mallocFailed ) goto select_end;
     pParse->nHeight -= sqlite3SelectExprHeight(p);
-    pTabList = p->pSrc;
-    if( !IgnorableOrderby(pDest) ){
-      pOrderBy = p->pOrderBy;
-    }
   }
-  pEList = p->pEList;
 #endif
+
+  /* Various elements of the SELECT copied into local variables for
+  ** convenience */
+  pEList = p->pEList;
   pWhere = p->pWhere;
   pGroupBy = p->pGroupBy;
   pHaving = p->pHaving;
-  isDistinct = (p->selFlags & SF_Distinct)!=0;
+  sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;
 
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-  /* If there is are a sequence of queries, do the earlier ones first.
-  */
-  if( p->pPrior ){
-    if( p->pRightmost==0 ){
-      Select *pLoop, *pRight = 0;
-      int cnt = 0;
-      int mxSelect;
-      for(pLoop=p; pLoop; pLoop=pLoop->pPrior, cnt++){
-        pLoop->pRightmost = p;
-        pLoop->pNext = pRight;
-        pRight = pLoop;
-      }
-      mxSelect = db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT];
-      if( mxSelect && cnt>mxSelect ){
-        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
-        goto select_end;
-      }
-    }
-    rc = multiSelect(pParse, p, pDest);
-    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
-    return rc;
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x400 ){
+    SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
   }
 #endif
 
-  /* If there is both a GROUP BY and an ORDER BY clause and they are
-  ** identical, then disable the ORDER BY clause since the GROUP BY
-  ** will cause elements to come out in the correct order.  This is
-  ** an optimization - the correct answer should result regardless.
-  ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER
-  ** to disable this optimization for testing purposes.
-  */
-  if( sqlite3ExprListCompare(p->pGroupBy, pOrderBy)==0
-         && (db->flags & SQLITE_GroupByOrder)==0 ){
-    pOrderBy = 0;
-  }
-
   /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and 
   ** if the select-list is the same as the ORDER BY list, then this query
   ** can be rewritten as a GROUP BY. In other words, this:
@@ -96618,7 +118592,7 @@ SQLITE_PRIVATE int sqlite3Select(
   **
   ** is transformed to:
   **
-  **     SELECT xyz FROM ... GROUP BY xyz
+  **     SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz
   **
   ** The second form is preferred as a single index (or temp-table) may be 
   ** used for both the ORDER BY and DISTINCT processing. As originally 
@@ -96626,133 +118600,117 @@ SQLITE_PRIVATE int sqlite3Select(
   ** BY and DISTINCT, and an index or separate temp-table for the other.
   */
   if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
-   && sqlite3ExprListCompare(pOrderBy, p->pEList)==0
+   && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
   ){
     p->selFlags &= ~SF_Distinct;
-    p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0);
-    pGroupBy = p->pGroupBy;
-    pOrderBy = 0;
+    pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
+    /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
+    ** the sDistinct.isTnct is still set.  Hence, isTnct represents the
+    ** original setting of the SF_Distinct flag, not the current setting */
+    assert( sDistinct.isTnct );
+
+#if SELECTTRACE_ENABLED
+    if( sqlite3SelectTrace & 0x400 ){
+      SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));
+      sqlite3TreeViewSelect(0, p, 0);
+    }
+#endif
   }
 
-  /* If there is an ORDER BY clause, then this sorting
-  ** index might end up being unused if the data can be 
-  ** extracted in pre-sorted order.  If that is the case, then the
-  ** OP_OpenEphemeral instruction will be changed to an OP_Noop once
-  ** we figure out that the sorting index is not needed.  The addrSortIndex
-  ** variable is used to facilitate that change.
+  /* If there is an ORDER BY clause, then create an ephemeral index to
+  ** do the sorting.  But this sorting ephemeral index might end up
+  ** being unused if the data can be extracted in pre-sorted order.
+  ** If that is the case, then the OP_OpenEphemeral instruction will be
+  ** changed to an OP_Noop once we figure out that the sorting index is
+  ** not needed.  The sSort.addrSortIndex variable is used to facilitate
+  ** that change.
   */
-  if( pOrderBy ){
+  if( sSort.pOrderBy ){
     KeyInfo *pKeyInfo;
-    pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
-    pOrderBy->iECursor = pParse->nTab++;
-    p->addrOpenEphm[2] = addrSortIndex =
+    pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, pEList->nExpr);
+    sSort.iECursor = pParse->nTab++;
+    sSort.addrSortIndex =
       sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
-                           pOrderBy->iECursor, pOrderBy->nExpr+2, 0,
-                           (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+          sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
+          (char*)pKeyInfo, P4_KEYINFO
+      );
   }else{
-    addrSortIndex = -1;
+    sSort.addrSortIndex = -1;
   }
 
   /* If the output is destined for a temporary table, open that table.
   */
   if( pDest->eDest==SRT_EphemTab ){
-    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, pEList->nExpr);
+    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);
   }
 
   /* Set the limiter.
   */
   iEnd = sqlite3VdbeMakeLabel(v);
-  p->nSelectRow = (double)LARGEST_INT64;
+  p->nSelectRow = 320;  /* 4 billion rows */
   computeLimitRegisters(pParse, p, iEnd);
-  if( p->iLimit==0 && addrSortIndex>=0 ){
-    sqlite3VdbeGetOp(v, addrSortIndex)->opcode = OP_SorterOpen;
-    p->selFlags |= SF_UseSorter;
+  if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
+    sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
+    sSort.sortFlags |= SORTFLAG_UseSorter;
   }
 
-  /* Open a virtual index to use for the distinct set.
+  /* Open an ephemeral index to use for the distinct set.
   */
   if( p->selFlags & SF_Distinct ){
-    KeyInfo *pKeyInfo;
-    distinct = pParse->nTab++;
-    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
-    addrDistinctIndex = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, distinct, 0, 0,
-        (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+    sDistinct.tabTnct = pParse->nTab++;
+    sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
+                             sDistinct.tabTnct, 0, 0,
+                             (char*)keyInfoFromExprList(pParse, p->pEList,0,0),
+                             P4_KEYINFO);
     sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
+    sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
   }else{
-    distinct = addrDistinctIndex = -1;
+    sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
   }
 
-  /* Aggregate and non-aggregate queries are handled differently */
   if( !isAgg && pGroupBy==0 ){
-    ExprList *pDist = (isDistinct ? p->pEList : 0);
+    /* No aggregate functions and no GROUP BY clause */
+    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0);
+    assert( WHERE_USE_LIMIT==SF_FixedLimit );
+    wctrlFlags |= p->selFlags & SF_FixedLimit;
 
     /* Begin the database scan. */
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pOrderBy, pDist, 0);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
+                               p->pEList, wctrlFlags, p->nSelectRow);
     if( pWInfo==0 ) goto select_end;
-    if( pWInfo->nRowOut < p->nSelectRow ) p->nSelectRow = pWInfo->nRowOut;
+    if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
+      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
+    }
+    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
+      sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
+    }
+    if( sSort.pOrderBy ){
+      sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
+      sSort.bOrderedInnerLoop = sqlite3WhereOrderedInnerLoop(pWInfo);
+      if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
+        sSort.pOrderBy = 0;
+      }
+    }
 
     /* If sorting index that was created by a prior OP_OpenEphemeral 
     ** instruction ended up not being needed, then change the OP_OpenEphemeral
     ** into an OP_Noop.
     */
-    if( addrSortIndex>=0 && pOrderBy==0 ){
-      sqlite3VdbeChangeToNoop(v, addrSortIndex);
-      p->addrOpenEphm[2] = -1;
-    }
-
-    if( pWInfo->eDistinct ){
-      VdbeOp *pOp;                /* No longer required OpenEphemeral instr. */
-     
-      assert( addrDistinctIndex>=0 );
-      pOp = sqlite3VdbeGetOp(v, addrDistinctIndex);
-
-      assert( isDistinct );
-      assert( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED 
-           || pWInfo->eDistinct==WHERE_DISTINCT_UNIQUE 
-      );
-      distinct = -1;
-      if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED ){
-        int iJump;
-        int iExpr;
-        int iFlag = ++pParse->nMem;
-        int iBase = pParse->nMem+1;
-        int iBase2 = iBase + pEList->nExpr;
-        pParse->nMem += (pEList->nExpr*2);
-
-        /* Change the OP_OpenEphemeral coded earlier to an OP_Integer. The
-        ** OP_Integer initializes the "first row" flag.  */
-        pOp->opcode = OP_Integer;
-        pOp->p1 = 1;
-        pOp->p2 = iFlag;
-
-        sqlite3ExprCodeExprList(pParse, pEList, iBase, 1);
-        iJump = sqlite3VdbeCurrentAddr(v) + 1 + pEList->nExpr + 1 + 1;
-        sqlite3VdbeAddOp2(v, OP_If, iFlag, iJump-1);
-        for(iExpr=0; iExpr<pEList->nExpr; iExpr++){
-          CollSeq *pColl = sqlite3ExprCollSeq(pParse, pEList->a[iExpr].pExpr);
-          sqlite3VdbeAddOp3(v, OP_Ne, iBase+iExpr, iJump, iBase2+iExpr);
-          sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
-          sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
-        }
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iContinue);
-
-        sqlite3VdbeAddOp2(v, OP_Integer, 0, iFlag);
-        assert( sqlite3VdbeCurrentAddr(v)==iJump );
-        sqlite3VdbeAddOp3(v, OP_Move, iBase, iBase2, pEList->nExpr);
-      }else{
-        pOp->opcode = OP_Noop;
-      }
+    if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){
+      sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
     }
 
     /* Use the standard inner loop. */
-    selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, pDest,
-                    pWInfo->iContinue, pWInfo->iBreak);
+    selectInnerLoop(pParse, p, pEList, -1, &sSort, &sDistinct, pDest,
+                    sqlite3WhereContinueLabel(pWInfo),
+                    sqlite3WhereBreakLabel(pWInfo));
 
     /* End the database scan loop.
     */
     sqlite3WhereEnd(pWInfo);
   }else{
-    /* This is the processing for aggregate queries */
+    /* This case when there exist aggregate functions or a GROUP BY clause
+    ** or both */
     NameContext sNC;    /* Name context for processing aggregate information */
     int iAMem;          /* First Mem address for storing current GROUP BY */
     int iBMem;          /* First Mem address for previous GROUP BY */
@@ -96764,6 +118722,7 @@ SQLITE_PRIVATE int sqlite3Select(
     int addrEnd;        /* End of processing for this SELECT */
     int sortPTab = 0;   /* Pseudotable used to decode sorting results */
     int sortOut = 0;    /* Output register from the sorter */
+    int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */
 
     /* Remove any and all aliases between the result set and the
     ** GROUP BY clause.
@@ -96773,16 +118732,29 @@ SQLITE_PRIVATE int sqlite3Select(
       struct ExprList_item *pItem;  /* For looping over expression in a list */
 
       for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){
-        pItem->iAlias = 0;
+        pItem->u.x.iAlias = 0;
       }
       for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
-        pItem->iAlias = 0;
+        pItem->u.x.iAlias = 0;
       }
-      if( p->nSelectRow>(double)100 ) p->nSelectRow = (double)100;
+      assert( 66==sqlite3LogEst(100) );
+      if( p->nSelectRow>66 ) p->nSelectRow = 66;
     }else{
-      p->nSelectRow = (double)1;
+      assert( 0==sqlite3LogEst(1) );
+      p->nSelectRow = 0;
     }
 
+    /* If there is both a GROUP BY and an ORDER BY clause and they are
+    ** identical, then it may be possible to disable the ORDER BY clause 
+    ** on the grounds that the GROUP BY will cause elements to come out 
+    ** in the correct order. It also may not - the GROUP BY might use a
+    ** database index that causes rows to be grouped together as required
+    ** but not actually sorted. Either way, record the fact that the
+    ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp
+    ** variable.  */
+    if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){
+      orderByGrp = 1;
+    }
  
     /* Create a label to jump to when we want to abort the query */
     addrEnd = sqlite3VdbeMakeLabel(v);
@@ -96795,18 +118767,22 @@ SQLITE_PRIVATE int sqlite3Select(
     sNC.pParse = pParse;
     sNC.pSrcList = pTabList;
     sNC.pAggInfo = &sAggInfo;
-    sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0;
+    sAggInfo.mnReg = pParse->nMem+1;
+    sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;
     sAggInfo.pGroupBy = pGroupBy;
     sqlite3ExprAnalyzeAggList(&sNC, pEList);
-    sqlite3ExprAnalyzeAggList(&sNC, pOrderBy);
+    sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);
     if( pHaving ){
       sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
     }
     sAggInfo.nAccumulator = sAggInfo.nColumn;
     for(i=0; i<sAggInfo.nFunc; i++){
       assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );
+      sNC.ncFlags |= NC_InAggFunc;
       sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
+      sNC.ncFlags &= ~NC_InAggFunc;
     }
+    sAggInfo.mxReg = pParse->nMem;
     if( db->mallocFailed ) goto select_end;
 
     /* Processing for aggregates with GROUP BY is very different and
@@ -96814,7 +118790,7 @@ SQLITE_PRIVATE int sqlite3Select(
     */
     if( pGroupBy ){
       KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
-      int j1;             /* A-vs-B comparision jump */
+      int addr1;          /* A-vs-B comparision jump */
       int addrOutputRow;  /* Start of subroutine that outputs a result row */
       int regOutputRow;   /* Return address register for output subroutine */
       int addrSetAbort;   /* Set the abort flag and return */
@@ -96829,10 +118805,10 @@ SQLITE_PRIVATE int sqlite3Select(
       ** will be converted into a Noop.  
       */
       sAggInfo.sortingIdx = pParse->nTab++;
-      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
+      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0, sAggInfo.nColumn);
       addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, 
           sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
-          0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
+          0, (char*)pKeyInfo, P4_KEYINFO);
 
       /* Initialize memory locations used by GROUP BY aggregate processing
       */
@@ -96850,6 +118826,7 @@ SQLITE_PRIVATE int sqlite3Select(
       VdbeComment((v, "clear abort flag"));
       sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
       VdbeComment((v, "indicate accumulator empty"));
+      sqlite3VdbeAddOp3(v, OP_Null, 0, iAMem, iAMem+pGroupBy->nExpr-1);
 
       /* Begin a loop that will extract all source rows in GROUP BY order.
       ** This might involve two separate loops with an OP_Sort in between, or
@@ -96857,14 +118834,15 @@ SQLITE_PRIVATE int sqlite3Select(
       ** in the right order to begin with.
       */
       sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
-      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy, 0, 0);
+      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
+          WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0
+      );
       if( pWInfo==0 ) goto select_end;
-      if( pGroupBy==0 ){
+      if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){
         /* The optimizer is able to deliver rows in group by order so
         ** we do not have to sort.  The OP_OpenEphemeral table will be
         ** cancelled later because we still need to use the pKeyInfo
         */
-        pGroupBy = p->pGroupBy;
         groupBySort = 0;
       }else{
         /* Rows are coming out in undetermined order.  We have to push
@@ -96878,12 +118856,13 @@ SQLITE_PRIVATE int sqlite3Select(
         int nGroupBy;
 
         explainTempTable(pParse, 
-            isDistinct && !(p->selFlags&SF_Distinct)?"DISTINCT":"GROUP BY");
+            (sDistinct.isTnct && (p->selFlags&SF_Distinct)==0) ?
+                    "DISTINCT" : "GROUP BY");
 
         groupBySort = 1;
         nGroupBy = pGroupBy->nExpr;
-        nCol = nGroupBy + 1;
-        j = nGroupBy+1;
+        nCol = nGroupBy;
+        j = nGroupBy;
         for(i=0; i<sAggInfo.nColumn; i++){
           if( sAggInfo.aCol[i].iSorterColumn>=j ){
             nCol++;
@@ -96892,20 +118871,14 @@ SQLITE_PRIVATE int sqlite3Select(
         }
         regBase = sqlite3GetTempRange(pParse, nCol);
         sqlite3ExprCacheClear(pParse);
-        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0);
-        sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx,regBase+nGroupBy);
-        j = nGroupBy+1;
+        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);
+        j = nGroupBy;
         for(i=0; i<sAggInfo.nColumn; i++){
           struct AggInfo_col *pCol = &sAggInfo.aCol[i];
           if( pCol->iSorterColumn>=j ){
             int r1 = j + regBase;
-            int r2;
-
-            r2 = sqlite3ExprCodeGetColumn(pParse, 
+            sqlite3ExprCodeGetColumnToReg(pParse, 
                                pCol->pTab, pCol->iColumn, pCol->iTable, r1);
-            if( r1!=r2 ){
-              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
-            }
             j++;
           }
         }
@@ -96919,9 +118892,24 @@ SQLITE_PRIVATE int sqlite3Select(
         sortOut = sqlite3GetTempReg(pParse);
         sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
         sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
-        VdbeComment((v, "GROUP BY sort"));
+        VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v);
         sAggInfo.useSortingIdx = 1;
         sqlite3ExprCacheClear(pParse);
+
+      }
+
+      /* If the index or temporary table used by the GROUP BY sort
+      ** will naturally deliver rows in the order required by the ORDER BY
+      ** clause, cancel the ephemeral table open coded earlier.
+      **
+      ** This is an optimization - the correct answer should result regardless.
+      ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to 
+      ** disable this optimization for testing purposes.  */
+      if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder) 
+       && (groupBySort || sqlite3WhereIsSorted(pWInfo))
+      ){
+        sSort.pOrderBy = 0;
+        sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
       }
 
       /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
@@ -96932,21 +118920,21 @@ SQLITE_PRIVATE int sqlite3Select(
       addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
       sqlite3ExprCacheClear(pParse);
       if( groupBySort ){
-        sqlite3VdbeAddOp2(v, OP_SorterData, sAggInfo.sortingIdx, sortOut);
+        sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx,
+                          sortOut, sortPTab);
       }
       for(j=0; j<pGroupBy->nExpr; j++){
         if( groupBySort ){
           sqlite3VdbeAddOp3(v, OP_Column, sortPTab, j, iBMem+j);
-          if( j==0 ) sqlite3VdbeChangeP5(v, OPFLAG_CLEARCACHE);
         }else{
           sAggInfo.directMode = 1;
           sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
         }
       }
       sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
-                          (char*)pKeyInfo, P4_KEYINFO);
-      j1 = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp3(v, OP_Jump, j1+1, 0, j1+1);
+                          (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
+      addr1 = sqlite3VdbeCurrentAddr(v);
+      sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);
 
       /* Generate code that runs whenever the GROUP BY changes.
       ** Changes in the GROUP BY are detected by the previous code
@@ -96960,7 +118948,7 @@ SQLITE_PRIVATE int sqlite3Select(
       sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
       sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
       VdbeComment((v, "output one row"));
-      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd);
+      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);
       VdbeComment((v, "check abort flag"));
       sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
       VdbeComment((v, "reset accumulator"));
@@ -96968,7 +118956,7 @@ SQLITE_PRIVATE int sqlite3Select(
       /* Update the aggregate accumulators based on the content of
       ** the current row
       */
-      sqlite3VdbeJumpHere(v, j1);
+      sqlite3VdbeJumpHere(v, addr1);
       updateAccumulator(pParse, &sAggInfo);
       sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
       VdbeComment((v, "indicate data in accumulator"));
@@ -96977,6 +118965,7 @@ SQLITE_PRIVATE int sqlite3Select(
       */
       if( groupBySort ){
         sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);
+        VdbeCoverage(v);
       }else{
         sqlite3WhereEnd(pWInfo);
         sqlite3VdbeChangeToNoop(v, addrSortingIdx);
@@ -96989,7 +118978,7 @@ SQLITE_PRIVATE int sqlite3Select(
 
       /* Jump over the subroutines
       */
-      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEnd);
+      sqlite3VdbeGoto(v, addrEnd);
 
       /* Generate a subroutine that outputs a single row of the result
       ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
@@ -97005,12 +118994,13 @@ SQLITE_PRIVATE int sqlite3Select(
       sqlite3VdbeResolveLabel(v, addrOutputRow);
       addrOutputRow = sqlite3VdbeCurrentAddr(v);
       sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
+      VdbeCoverage(v);
       VdbeComment((v, "Groupby result generator entry point"));
       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
       finalizeAggFunctions(pParse, &sAggInfo);
       sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
-      selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
-                      distinct, pDest,
+      selectInnerLoop(pParse, p, p->pEList, -1, &sSort,
+                      &sDistinct, pDest,
                       addrOutputRow+1, addrSetAbort);
       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
       VdbeComment((v, "end groupby result generator"));
@@ -97050,33 +119040,34 @@ SQLITE_PRIVATE int sqlite3Select(
         sqlite3CodeVerifySchema(pParse, iDb);
         sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
 
-        /* Search for the index that has the least amount of columns. If
-        ** there is such an index, and it has less columns than the table
-        ** does, then we can assume that it consumes less space on disk and
-        ** will therefore be cheaper to scan to determine the query result.
-        ** In this case set iRoot to the root page number of the index b-tree
-        ** and pKeyInfo to the KeyInfo structure required to navigate the
-        ** index.
+        /* Search for the index that has the lowest scan cost.
         **
         ** (2011-04-15) Do not do a full scan of an unordered index.
         **
+        ** (2013-10-03) Do not count the entries in a partial index.
+        **
         ** In practice the KeyInfo structure will not be used. It is only 
         ** passed to keep OP_OpenRead happy.
         */
+        if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);
         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-          if( pIdx->bUnordered==0 && (!pBest || pIdx->nColumn<pBest->nColumn) ){
+          if( pIdx->bUnordered==0
+           && pIdx->szIdxRow<pTab->szTabRow
+           && pIdx->pPartIdxWhere==0
+           && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
+          ){
             pBest = pIdx;
           }
         }
-        if( pBest && pBest->nColumn<pTab->nCol ){
+        if( pBest ){
           iRoot = pBest->tnum;
-          pKeyInfo = sqlite3IndexKeyinfo(pParse, pBest);
+          pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);
         }
 
         /* Open a read-only cursor, execute the OP_Count, close the cursor. */
-        sqlite3VdbeAddOp3(v, OP_OpenRead, iCsr, iRoot, iDb);
+        sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);
         if( pKeyInfo ){
-          sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO_HANDOFF);
+          sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
         }
         sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
         sqlite3VdbeAddOp1(v, OP_Close, iCsr);
@@ -97098,7 +119089,7 @@ SQLITE_PRIVATE int sqlite3Select(
         ** value of x, the only row required).
         **
         ** A special flag must be passed to sqlite3WhereBegin() to slightly
-        ** modify behaviour as follows:
+        ** modify behavior as follows:
         **
         **   + If the query is a "SELECT min(x)", then the loop coded by
         **     where.c should not iterate over any values with a NULL value
@@ -97110,12 +119101,20 @@ SQLITE_PRIVATE int sqlite3Select(
         **     Refer to code and comments in where.c for details.
         */
         ExprList *pMinMax = 0;
-        u8 flag = minMaxQuery(p);
+        u8 flag = WHERE_ORDERBY_NORMAL;
+        
+        assert( p->pGroupBy==0 );
+        assert( flag==0 );
+        if( p->pHaving==0 ){
+          flag = minMaxQuery(&sAggInfo, &pMinMax);
+        }
+        assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) );
+
         if( flag ){
-          assert( !ExprHasProperty(p->pEList->a[0].pExpr, EP_xIsSelect) );
-          pMinMax = sqlite3ExprListDup(db, p->pEList->a[0].pExpr->x.pList,0);
+          pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
           pDel = pMinMax;
-          if( pMinMax && !db->mallocFailed ){
+          assert( db->mallocFailed || pMinMax!=0 );
+          if( !db->mallocFailed ){
             pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
             pMinMax->a[0].pExpr->op = TK_COLUMN;
           }
@@ -97126,14 +119125,15 @@ SQLITE_PRIVATE int sqlite3Select(
         ** of output.
         */
         resetAccumulator(pParse, &sAggInfo);
-        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pMinMax, 0, flag);
+        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMax,0,flag,0);
         if( pWInfo==0 ){
           sqlite3ExprListDelete(db, pDel);
           goto select_end;
         }
         updateAccumulator(pParse, &sAggInfo);
-        if( !pMinMax && flag ){
-          sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak);
+        assert( pMinMax==0 || pMinMax->nExpr==1 );
+        if( sqlite3WhereIsOrdered(pWInfo)>0 ){
+          sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
           VdbeComment((v, "%s() by index",
                 (flag==WHERE_ORDERBY_MIN?"min":"max")));
         }
@@ -97141,9 +119141,9 @@ SQLITE_PRIVATE int sqlite3Select(
         finalizeAggFunctions(pParse, &sAggInfo);
       }
 
-      pOrderBy = 0;
+      sSort.pOrderBy = 0;
       sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
-      selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, -1, 
+      selectInnerLoop(pParse, p, p->pEList, -1, 0, 0, 
                       pDest, addrEnd, addrEnd);
       sqlite3ExprListDelete(db, pDel);
     }
@@ -97151,26 +119151,26 @@ SQLITE_PRIVATE int sqlite3Select(
     
   } /* endif aggregate query */
 
-  if( distinct>=0 ){
+  if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
     explainTempTable(pParse, "DISTINCT");
   }
 
   /* If there is an ORDER BY clause, then we need to sort the results
   ** and send them to the callback one by one.
   */
-  if( pOrderBy ){
-    explainTempTable(pParse, "ORDER BY");
-    generateSortTail(pParse, p, v, pEList->nExpr, pDest);
+  if( sSort.pOrderBy ){
+    explainTempTable(pParse,
+                     sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
+    generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
   }
 
   /* Jump here to skip this query
   */
   sqlite3VdbeResolveLabel(v, iEnd);
 
-  /* The SELECT was successfully coded.   Set the return code to 0
-  ** to indicate no errors.
-  */
-  rc = 0;
+  /* The SELECT has been coded. If there is an error in the Parse structure,
+  ** set the return code to 1. Otherwise 0. */
+  rc = (pParse->nErr>0);
 
   /* Control jumps to here if an error is encountered above, or upon
   ** successful coding of the SELECT.
@@ -97186,105 +119186,13 @@ select_end:
 
   sqlite3DbFree(db, sAggInfo.aCol);
   sqlite3DbFree(db, sAggInfo.aFunc);
+#if SELECTTRACE_ENABLED
+  SELECTTRACE(1,pParse,p,("end processing\n"));
+  pParse->nSelectIndent--;
+#endif
   return rc;
 }
 
-#if defined(SQLITE_DEBUG)
-/*
-*******************************************************************************
-** The following code is used for testing and debugging only.  The code
-** that follows does not appear in normal builds.
-**
-** These routines are used to print out the content of all or part of a 
-** parse structures such as Select or Expr.  Such printouts are useful
-** for helping to understand what is happening inside the code generator
-** during the execution of complex SELECT statements.
-**
-** These routine are not called anywhere from within the normal
-** code base.  Then are intended to be called from within the debugger
-** or from temporary "printf" statements inserted for debugging.
-*/
-SQLITE_PRIVATE void sqlite3PrintExpr(Expr *p){
-  if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
-    sqlite3DebugPrintf("(%s", p->u.zToken);
-  }else{
-    sqlite3DebugPrintf("(%d", p->op);
-  }
-  if( p->pLeft ){
-    sqlite3DebugPrintf(" ");
-    sqlite3PrintExpr(p->pLeft);
-  }
-  if( p->pRight ){
-    sqlite3DebugPrintf(" ");
-    sqlite3PrintExpr(p->pRight);
-  }
-  sqlite3DebugPrintf(")");
-}
-SQLITE_PRIVATE void sqlite3PrintExprList(ExprList *pList){
-  int i;
-  for(i=0; i<pList->nExpr; i++){
-    sqlite3PrintExpr(pList->a[i].pExpr);
-    if( i<pList->nExpr-1 ){
-      sqlite3DebugPrintf(", ");
-    }
-  }
-}
-SQLITE_PRIVATE void sqlite3PrintSelect(Select *p, int indent){
-  sqlite3DebugPrintf("%*sSELECT(%p) ", indent, "", p);
-  sqlite3PrintExprList(p->pEList);
-  sqlite3DebugPrintf("\n");
-  if( p->pSrc ){
-    char *zPrefix;
-    int i;
-    zPrefix = "FROM";
-    for(i=0; i<p->pSrc->nSrc; i++){
-      struct SrcList_item *pItem = &p->pSrc->a[i];
-      sqlite3DebugPrintf("%*s ", indent+6, zPrefix);
-      zPrefix = "";
-      if( pItem->pSelect ){
-        sqlite3DebugPrintf("(\n");
-        sqlite3PrintSelect(pItem->pSelect, indent+10);
-        sqlite3DebugPrintf("%*s)", indent+8, "");
-      }else if( pItem->zName ){
-        sqlite3DebugPrintf("%s", pItem->zName);
-      }
-      if( pItem->pTab ){
-        sqlite3DebugPrintf("(table: %s)", pItem->pTab->zName);
-      }
-      if( pItem->zAlias ){
-        sqlite3DebugPrintf(" AS %s", pItem->zAlias);
-      }
-      if( i<p->pSrc->nSrc-1 ){
-        sqlite3DebugPrintf(",");
-      }
-      sqlite3DebugPrintf("\n");
-    }
-  }
-  if( p->pWhere ){
-    sqlite3DebugPrintf("%*s WHERE ", indent, "");
-    sqlite3PrintExpr(p->pWhere);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pGroupBy ){
-    sqlite3DebugPrintf("%*s GROUP BY ", indent, "");
-    sqlite3PrintExprList(p->pGroupBy);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pHaving ){
-    sqlite3DebugPrintf("%*s HAVING ", indent, "");
-    sqlite3PrintExpr(p->pHaving);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pOrderBy ){
-    sqlite3DebugPrintf("%*s ORDER BY ", indent, "");
-    sqlite3PrintExprList(p->pOrderBy);
-    sqlite3DebugPrintf("\n");
-  }
-}
-/* End of the structure debug printing code
-*****************************************************************************/
-#endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */
-
 /************** End of select.c **********************************************/
 /************** Begin file table.c *******************************************/
 /*
@@ -97305,6 +119213,7 @@ SQLITE_PRIVATE void sqlite3PrintSelect(Select *p, int indent){
 ** These routines are in a separate files so that they will not be linked
 ** if they are not used.
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 /* #include <string.h> */
 
@@ -97317,10 +119226,10 @@ SQLITE_PRIVATE void sqlite3PrintSelect(Select *p, int indent){
 typedef struct TabResult {
   char **azResult;   /* Accumulated output */
   char *zErrMsg;     /* Error message text, if an error occurs */
-  int nAlloc;        /* Slots allocated for azResult[] */
-  int nRow;          /* Number of rows in the result */
-  int nColumn;       /* Number of columns in the result */
-  int nData;         /* Slots used in azResult[].  (nRow+1)*nColumn */
+  u32 nAlloc;        /* Slots allocated for azResult[] */
+  u32 nRow;          /* Number of rows in the result */
+  u32 nColumn;       /* Number of columns in the result */
+  u32 nData;         /* Slots used in azResult[].  (nRow+1)*nColumn */
   int rc;            /* Return code from sqlite3_exec() */
 } TabResult;
 
@@ -97346,7 +119255,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
   if( p->nData + need > p->nAlloc ){
     char **azNew;
     p->nAlloc = p->nAlloc*2 + need;
-    azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
+    azNew = sqlite3_realloc64( p->azResult, sizeof(char*)*p->nAlloc );
     if( azNew==0 ) goto malloc_failed;
     p->azResult = azNew;
   }
@@ -97361,7 +119270,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
       if( z==0 ) goto malloc_failed;
       p->azResult[p->nData++] = z;
     }
-  }else if( p->nColumn!=nCol ){
+  }else if( (int)p->nColumn!=nCol ){
     sqlite3_free(p->zErrMsg);
     p->zErrMsg = sqlite3_mprintf(
        "sqlite3_get_table() called with two or more incompatible queries"
@@ -97378,7 +119287,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
         z = 0;
       }else{
         int n = sqlite3Strlen30(argv[i])+1;
-        z = sqlite3_malloc( n );
+        z = sqlite3_malloc64( n );
         if( z==0 ) goto malloc_failed;
         memcpy(z, argv[i], n);
       }
@@ -97389,7 +119298,7 @@ static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
   return 0;
 
 malloc_failed:
-  p->rc = SQLITE_NOMEM;
+  p->rc = SQLITE_NOMEM_BKPT;
   return 1;
 }
 
@@ -97403,7 +119312,7 @@ malloc_failed:
 ** Instead, the entire table should be passed to sqlite3_free_table() when
 ** the calling procedure is finished using it.
 */
-SQLITE_API int sqlite3_get_table(
+SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
   sqlite3 *db,                /* The database on which the SQL executes */
   const char *zSql,           /* The SQL to be executed */
   char ***pazResult,          /* Write the result table here */
@@ -97414,6 +119323,9 @@ SQLITE_API int sqlite3_get_table(
   int rc;
   TabResult res;
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || pazResult==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   *pazResult = 0;
   if( pnColumn ) *pnColumn = 0;
   if( pnRow ) *pnRow = 0;
@@ -97424,10 +119336,10 @@ SQLITE_API int sqlite3_get_table(
   res.nData = 1;
   res.nAlloc = 20;
   res.rc = SQLITE_OK;
-  res.azResult = sqlite3_malloc(sizeof(char*)*res.nAlloc );
+  res.azResult = sqlite3_malloc64(sizeof(char*)*res.nAlloc );
   if( res.azResult==0 ){
      db->errCode = SQLITE_NOMEM;
-     return SQLITE_NOMEM;
+     return SQLITE_NOMEM_BKPT;
   }
   res.azResult[0] = 0;
   rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
@@ -97452,11 +119364,11 @@ SQLITE_API int sqlite3_get_table(
   }
   if( res.nAlloc>res.nData ){
     char **azNew;
-    azNew = sqlite3_realloc( res.azResult, sizeof(char*)*res.nData );
+    azNew = sqlite3_realloc64( res.azResult, sizeof(char*)*res.nData );
     if( azNew==0 ){
       sqlite3_free_table(&res.azResult[1]);
       db->errCode = SQLITE_NOMEM;
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     res.azResult = azNew;
   }
@@ -97469,8 +119381,8 @@ SQLITE_API int sqlite3_get_table(
 /*
 ** This routine frees the space the sqlite3_get_table() malloced.
 */
-SQLITE_API void sqlite3_free_table(
-  char **azResult            /* Result returned from from sqlite3_get_table() */
+SQLITE_API void SQLITE_STDCALL sqlite3_free_table(
+  char **azResult            /* Result returned from sqlite3_get_table() */
 ){
   if( azResult ){
     int i, n;
@@ -97498,6 +119410,7 @@ SQLITE_API void sqlite3_free_table(
 *************************************************************************
 ** This file contains the implementation for TRIGGERs
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_TRIGGER
 /*
@@ -97598,7 +119511,7 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
     iDb = 1;
     pName = pName1;
   }else{
-    /* Figure out the db that the the trigger will be created in */
+    /* Figure out the db that the trigger will be created in */
     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
     if( iDb<0 ){
       goto trigger_cleanup;
@@ -97614,7 +119527,7 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
   **                                                 ^^^^^^^^
   **
   ** To maintain backwards compatibility, ignore the database
-  ** name on pTableName if we are reparsing our of SQLITE_MASTER.
+  ** name on pTableName if we are reparsing out of SQLITE_MASTER.
   */
   if( db->init.busy && iDb!=1 ){
     sqlite3DbFree(db, pTableName->a[0].zDatabase);
@@ -97635,8 +119548,8 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
   /* Ensure the table name matches database name and that the table exists */
   if( db->mallocFailed ) goto trigger_cleanup;
   assert( pTableName->nSrc==1 );
-  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) && 
-      sqlite3FixSrcList(&sFix, pTableName) ){
+  sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);
+  if( sqlite3FixSrcList(&sFix, pTableName) ){
     goto trigger_cleanup;
   }
   pTab = sqlite3SrcListLookup(pParse, pTableName);
@@ -97667,8 +119580,7 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
     goto trigger_cleanup;
   }
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-  if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),
-                      zName, sqlite3Strlen30(zName)) ){
+  if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
     if( !noErr ){
       sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
     }else{
@@ -97681,7 +119593,6 @@ SQLITE_PRIVATE void sqlite3BeginTrigger(
   /* Do not create a trigger on a system table */
   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
     sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
-    pParse->nErr++;
     goto trigger_cleanup;
   }
 
@@ -97776,10 +119687,11 @@ SQLITE_PRIVATE void sqlite3FinishTrigger(
     pStepList->pTrig = pTrig;
     pStepList = pStepList->pNext;
   }
-  nameToken.z = pTrig->zName;
-  nameToken.n = sqlite3Strlen30(nameToken.z);
-  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken) 
-          && sqlite3FixTriggerStep(&sFix, pTrig->step_list) ){
+  sqlite3TokenInit(&nameToken, pTrig->zName);
+  sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
+  if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 
+   || sqlite3FixExpr(&sFix, pTrig->pWhen) 
+  ){
     goto triggerfinish_cleanup;
   }
 
@@ -97809,13 +119721,12 @@ SQLITE_PRIVATE void sqlite3FinishTrigger(
     Trigger *pLink = pTrig;
     Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-    pTrig = sqlite3HashInsert(pHash, zName, sqlite3Strlen30(zName), pTrig);
+    pTrig = sqlite3HashInsert(pHash, zName, pTrig);
     if( pTrig ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
     }else if( pLink->pSchema==pLink->pTabSchema ){
       Table *pTab;
-      int n = sqlite3Strlen30(pLink->table);
-      pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table, n);
+      pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);
       assert( pTab!=0 );
       pLink->pNext = pTab->pTrigger;
       pTab->pTrigger = pLink;
@@ -97860,12 +119771,12 @@ static TriggerStep *triggerStepAllocate(
 ){
   TriggerStep *pTriggerStep;
 
-  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n);
+  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);
   if( pTriggerStep ){
     char *z = (char*)&pTriggerStep[1];
     memcpy(z, pName->z, pName->n);
-    pTriggerStep->target.z = z;
-    pTriggerStep->target.n = pName->n;
+    sqlite3Dequote(z);
+    pTriggerStep->zTarget = z;
     pTriggerStep->op = op;
   }
   return pTriggerStep;
@@ -97882,25 +119793,21 @@ SQLITE_PRIVATE TriggerStep *sqlite3TriggerInsertStep(
   sqlite3 *db,        /* The database connection */
   Token *pTableName,  /* Name of the table into which we insert */
   IdList *pColumn,    /* List of columns in pTableName to insert into */
-  ExprList *pEList,   /* The VALUE clause: a list of values to be inserted */
   Select *pSelect,    /* A SELECT statement that supplies values */
   u8 orconf           /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
 ){
   TriggerStep *pTriggerStep;
 
-  assert(pEList == 0 || pSelect == 0);
-  assert(pEList != 0 || pSelect != 0 || db->mallocFailed);
+  assert(pSelect != 0 || db->mallocFailed);
 
   pTriggerStep = triggerStepAllocate(db, TK_INSERT, pTableName);
   if( pTriggerStep ){
     pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
     pTriggerStep->pIdList = pColumn;
-    pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE);
     pTriggerStep->orconf = orconf;
   }else{
     sqlite3IdListDelete(db, pColumn);
   }
-  sqlite3ExprListDelete(db, pEList);
   sqlite3SelectDelete(db, pSelect);
 
   return pTriggerStep;
@@ -97978,7 +119885,6 @@ SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr)
   int i;
   const char *zDb;
   const char *zName;
-  int nName;
   sqlite3 *db = pParse->db;
 
   if( db->mallocFailed ) goto drop_trigger_cleanup;
@@ -97989,13 +119895,12 @@ SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr)
   assert( pName->nSrc==1 );
   zDb = pName->a[0].zDatabase;
   zName = pName->a[0].zName;
-  nName = sqlite3Strlen30(zName);
   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
   for(i=OMIT_TEMPDB; i<db->nDb; i++){
     int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
     if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
     assert( sqlite3SchemaMutexHeld(db, j, 0) );
-    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName);
+    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);
     if( pTrigger ) break;
   }
   if( !pTrigger ){
@@ -98018,8 +119923,7 @@ drop_trigger_cleanup:
 ** is set on.
 */
 static Table *tableOfTrigger(Trigger *pTrigger){
-  int n = sqlite3Strlen30(pTrigger->table);
-  return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table, n);
+  return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table);
 }
 
 
@@ -98054,30 +119958,12 @@ SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
   */
   assert( pTable!=0 );
   if( (v = sqlite3GetVdbe(pParse))!=0 ){
-    int base;
-    static const VdbeOpList dropTrigger[] = {
-      { OP_Rewind,     0, ADDR(9),  0},
-      { OP_String8,    0, 1,        0}, /* 1 */
-      { OP_Column,     0, 1,        2},
-      { OP_Ne,         2, ADDR(8),  1},
-      { OP_String8,    0, 1,        0}, /* 4: "trigger" */
-      { OP_Column,     0, 0,        2},
-      { OP_Ne,         2, ADDR(8),  1},
-      { OP_Delete,     0, 0,        0},
-      { OP_Next,       0, ADDR(1),  0}, /* 8 */
-    };
-
-    sqlite3BeginWriteOperation(pParse, 0, iDb);
-    sqlite3OpenMasterTable(pParse, iDb);
-    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);
-    sqlite3VdbeChangeP4(v, base+1, pTrigger->zName, P4_TRANSIENT);
-    sqlite3VdbeChangeP4(v, base+4, "trigger", P4_STATIC);
+    sqlite3NestedParse(pParse,
+       "DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",
+       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pTrigger->zName
+    );
     sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
     sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
-    if( pParse->nMem<3 ){
-      pParse->nMem = 3;
-    }
   }
 }
 
@@ -98090,7 +119976,7 @@ SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const ch
 
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   pHash = &(db->aDb[iDb].pSchema->trigHash);
-  pTrigger = sqlite3HashInsert(pHash, zName, sqlite3Strlen30(zName), 0);
+  pTrigger = sqlite3HashInsert(pHash, zName, 0);
   if( ALWAYS(pTrigger) ){
     if( pTrigger->pSchema==pTrigger->pTabSchema ){
       Table *pTab = tableOfTrigger(pTrigger);
@@ -98154,7 +120040,7 @@ SQLITE_PRIVATE Trigger *sqlite3TriggersExist(
 }
 
 /*
-** Convert the pStep->target token into a SrcList and return a pointer
+** Convert the pStep->zTarget string into a SrcList and return a pointer
 ** to that SrcList.
 **
 ** This routine adds a specific database name, if needed, to the target when
@@ -98167,17 +120053,17 @@ static SrcList *targetSrcList(
   Parse *pParse,       /* The parsing context */
   TriggerStep *pStep   /* The trigger containing the target token */
 ){
+  sqlite3 *db = pParse->db;
   int iDb;             /* Index of the database to use */
   SrcList *pSrc;       /* SrcList to be returned */
 
-  pSrc = sqlite3SrcListAppend(pParse->db, 0, &pStep->target, 0);
+  pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
   if( pSrc ){
     assert( pSrc->nSrc>0 );
-    assert( pSrc->a!=0 );
-    iDb = sqlite3SchemaToIndex(pParse->db, pStep->pTrig->pSchema);
+    pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);
+    iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);
     if( iDb==0 || iDb>=2 ){
-      sqlite3 *db = pParse->db;
-      assert( iDb<pParse->db->nDb );
+      assert( iDb<db->nDb );
       pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
     }
   }
@@ -98215,6 +120101,7 @@ static int codeTriggerProgram(
     **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy
     */
     pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
+    assert( pParse->okConstFactor==0 );
 
     switch( pStep->op ){
       case TK_UPDATE: {
@@ -98229,7 +120116,6 @@ static int codeTriggerProgram(
       case TK_INSERT: {
         sqlite3Insert(pParse, 
           targetSrcList(pParse, pStep),
-          sqlite3ExprListDup(db, pStep->pExprList, 0), 
           sqlite3SelectDup(db, pStep->pSelect, 0), 
           sqlite3IdListDup(db, pStep->pIdList), 
           pParse->eOrconf
@@ -98260,7 +120146,7 @@ static int codeTriggerProgram(
   return 0;
 }
 
-#ifdef SQLITE_DEBUG
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
 /*
 ** This function is used to add VdbeComment() annotations to a VDBE
 ** program. It is not used in production code, only for debugging.
@@ -98289,6 +120175,7 @@ static void transferParseError(Parse *pTo, Parse *pFrom){
   if( pTo->nErr==0 ){
     pTo->zErrMsg = pFrom->zErrMsg;
     pTo->nErr = pFrom->nErr;
+    pTo->rc = pFrom->rc;
   }else{
     sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
   }
@@ -98391,6 +120278,7 @@ static TriggerPrg *codeRowTrigger(
     }
     pProgram->nMem = pSubParse->nMem;
     pProgram->nCsr = pSubParse->nTab;
+    pProgram->nOnce = pSubParse->nOnce;
     pProgram->token = (void *)pTrigger;
     pPrg->aColmask[0] = pSubParse->oldmask;
     pPrg->aColmask[1] = pSubParse->newmask;
@@ -98399,6 +120287,7 @@ static TriggerPrg *codeRowTrigger(
 
   assert( !pSubParse->pAinc       && !pSubParse->pZombieTab );
   assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );
+  sqlite3ParserReset(pSubParse);
   sqlite3StackFree(db, pSubParse);
 
   return pPrg;
@@ -98462,8 +120351,8 @@ SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(
   if( pPrg ){
     int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));
 
-    sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem);
-    sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM);
+    sqlite3VdbeAddOp4(v, OP_Program, reg, ignoreJump, ++pParse->nMem,
+                      (const char *)pPrg->pProgram, P4_SUBPROGRAM);
     VdbeComment(
         (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));
 
@@ -98479,7 +120368,7 @@ SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(
 /*
 ** This is called to code the required FOR EACH ROW triggers for an operation
 ** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
-** is given by the op paramater. The tr_tm parameter determines whether the
+** is given by the op parameter. The tr_tm parameter determines whether the
 ** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
 ** parameter pChanges is passed the list of columns being modified.
 **
@@ -98625,6 +120514,7 @@ SQLITE_PRIVATE u32 sqlite3TriggerColmask(
 ** This file contains C code routines that are called by the parser
 ** to handle UPDATE statements.
 */
+/* #include "sqliteInt.h" */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /* Forward declaration */
@@ -98673,7 +120563,7 @@ static void updateVirtualTable(
 SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
   assert( pTab!=0 );
   if( !pTab->pSelect ){
-    sqlite3_value *pValue;
+    sqlite3_value *pValue = 0;
     u8 enc = ENC(sqlite3VdbeDb(v));
     Column *pCol = &pTab->aCol[i];
     VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
@@ -98684,7 +120574,7 @@ SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
       sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
     }
 #ifndef SQLITE_OMIT_FLOATING_POINT
-    if( iReg>=0 && pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
+    if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
       sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
     }
 #endif
@@ -98707,25 +120597,32 @@ SQLITE_PRIVATE void sqlite3Update(
 ){
   int i, j;              /* Loop counters */
   Table *pTab;           /* The table to be updated */
-  int addr = 0;          /* VDBE instruction address of the start of the loop */
+  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
   WhereInfo *pWInfo;     /* Information about the WHERE clause */
   Vdbe *v;               /* The virtual database engine */
   Index *pIdx;           /* For looping over indices */
+  Index *pPk;            /* The PRIMARY KEY index for WITHOUT ROWID tables */
   int nIdx;              /* Number of indices that need updating */
-  int iCur;              /* VDBE Cursor number of pTab */
+  int iBaseCur;          /* Base cursor number */
+  int iDataCur;          /* Cursor for the canonical data btree */
+  int iIdxCur;           /* Cursor for the first index */
   sqlite3 *db;           /* The database structure */
   int *aRegIdx = 0;      /* One register assigned to each index to be updated */
   int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
                          ** an expression for the i-th column of the table.
                          ** aXRef[i]==-1 if the i-th column is not changed. */
-  int chngRowid;         /* True if the record number is being changed */
+  u8 *aToOpen;           /* 1 for tables and indices to be opened */
+  u8 chngPk;             /* PRIMARY KEY changed in a WITHOUT ROWID table */
+  u8 chngRowid;          /* Rowid changed in a normal table */
+  u8 chngKey;            /* Either chngPk or chngRowid */
   Expr *pRowidExpr = 0;  /* Expression defining the new record number */
-  int openAll = 0;       /* True if all indices need to be opened */
   AuthContext sContext;  /* The authorization context */
   NameContext sNC;       /* The name-context to resolve expressions in */
   int iDb;               /* Database containing the table being updated */
   int okOnePass;         /* True for one-pass algorithm without the FIFO */
   int hasFK;             /* True if foreign key processing is required */
+  int labelBreak;        /* Jump here to break out of UPDATE loop */
+  int labelContinue;     /* Jump here to continue next step of UPDATE loop */
 
 #ifndef SQLITE_OMIT_TRIGGER
   int isView;            /* True when updating a view (INSTEAD OF trigger) */
@@ -98733,14 +120630,18 @@ SQLITE_PRIVATE void sqlite3Update(
   int tmask;             /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
 #endif
   int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */
+  int iEph = 0;          /* Ephemeral table holding all primary key values */
+  int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
+  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
 
   /* Register Allocations */
   int regRowCount = 0;   /* A count of rows changed */
-  int regOldRowid;       /* The old rowid */
-  int regNewRowid;       /* The new rowid */
-  int regNew;
-  int regOld = 0;
+  int regOldRowid = 0;   /* The old rowid */
+  int regNewRowid = 0;   /* The new rowid */
+  int regNew = 0;        /* Content of the NEW.* table in triggers */
+  int regOld = 0;        /* Content of OLD.* table in triggers */
   int regRowSet = 0;     /* Rowset of rows to be updated */
+  int regKey = 0;        /* composite PRIMARY KEY value */
 
   memset(&sContext, 0, sizeof(sContext));
   db = pParse->db;
@@ -98778,20 +120679,34 @@ SQLITE_PRIVATE void sqlite3Update(
   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
     goto update_cleanup;
   }
-  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol );
-  if( aXRef==0 ) goto update_cleanup;
-  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
 
   /* Allocate a cursors for the main database table and for all indices.
   ** The index cursors might not be used, but if they are used they
   ** need to occur right after the database cursor.  So go ahead and
   ** allocate enough space, just in case.
   */
-  pTabList->a[0].iCursor = iCur = pParse->nTab++;
-  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+  pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++;
+  iIdxCur = iDataCur+1;
+  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
+    if( IsPrimaryKeyIndex(pIdx) && pPk!=0 ){
+      iDataCur = pParse->nTab;
+      pTabList->a[0].iCursor = iDataCur;
+    }
     pParse->nTab++;
   }
 
+  /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  
+  ** Initialize aXRef[] and aToOpen[] to their default values.
+  */
+  aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
+  if( aXRef==0 ) goto update_cleanup;
+  aRegIdx = aXRef+pTab->nCol;
+  aToOpen = (u8*)(aRegIdx+nIdx);
+  memset(aToOpen, 1, nIdx+1);
+  aToOpen[nIdx+1] = 0;
+  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
+
   /* Initialize the name-context */
   memset(&sNC, 0, sizeof(sNC));
   sNC.pParse = pParse;
@@ -98803,7 +120718,7 @@ SQLITE_PRIVATE void sqlite3Update(
   ** column to be updated, make sure we have authorization to change
   ** that column.
   */
-  chngRowid = 0;
+  chngRowid = chngPk = 0;
   for(i=0; i<pChanges->nExpr; i++){
     if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
       goto update_cleanup;
@@ -98813,13 +120728,16 @@ SQLITE_PRIVATE void sqlite3Update(
         if( j==pTab->iPKey ){
           chngRowid = 1;
           pRowidExpr = pChanges->a[i].pExpr;
+        }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
+          chngPk = 1;
         }
         aXRef[j] = i;
         break;
       }
     }
     if( j>=pTab->nCol ){
-      if( sqlite3IsRowid(pChanges->a[i].zName) ){
+      if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
+        j = -1;
         chngRowid = 1;
         pRowidExpr = pChanges->a[i].pExpr;
       }else{
@@ -98832,7 +120750,8 @@ SQLITE_PRIVATE void sqlite3Update(
     {
       int rc;
       rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
-                           pTab->aCol[j].zName, db->aDb[iDb].zName);
+                            j<0 ? "ROWID" : pTab->aCol[j].zName,
+                            db->aDb[iDb].zName);
       if( rc==SQLITE_DENY ){
         goto update_cleanup;
       }else if( rc==SQLITE_IGNORE ){
@@ -98841,32 +120760,41 @@ SQLITE_PRIVATE void sqlite3Update(
     }
 #endif
   }
+  assert( (chngRowid & chngPk)==0 );
+  assert( chngRowid==0 || chngRowid==1 );
+  assert( chngPk==0 || chngPk==1 );
+  chngKey = chngRowid + chngPk;
+
+  /* The SET expressions are not actually used inside the WHERE loop.  
+  ** So reset the colUsed mask. Unless this is a virtual table. In that
+  ** case, set all bits of the colUsed mask (to ensure that the virtual
+  ** table implementation makes all columns available).
+  */
+  pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
 
-  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngRowid);
+  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
 
-  /* Allocate memory for the array aRegIdx[].  There is one entry in the
-  ** array for each index associated with table being updated.  Fill in
-  ** the value with a register number for indices that are to be used
-  ** and with zero for unused indices.
+  /* There is one entry in the aRegIdx[] array for each index on the table
+  ** being updated.  Fill in aRegIdx[] with a register number that will hold
+  ** the key for accessing each index.
+  **
+  ** FIXME:  Be smarter about omitting indexes that use expressions.
   */
-  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
-  if( nIdx>0 ){
-    aRegIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx );
-    if( aRegIdx==0 ) goto update_cleanup;
-  }
   for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
     int reg;
-    if( hasFK || chngRowid ){
+    if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
       reg = ++pParse->nMem;
     }else{
       reg = 0;
-      for(i=0; i<pIdx->nColumn; i++){
-        if( aXRef[pIdx->aiColumn[i]]>=0 ){
+      for(i=0; i<pIdx->nKeyCol; i++){
+        i16 iIdxCol = pIdx->aiColumn[i];
+        if( iIdxCol<0 || aXRef[iIdxCol]>=0 ){
           reg = ++pParse->nMem;
           break;
         }
       }
     }
+    if( reg==0 ) aToOpen[j+1] = 0;
     aRegIdx[j] = reg;
   }
 
@@ -98876,28 +120804,20 @@ SQLITE_PRIVATE void sqlite3Update(
   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
   sqlite3BeginWriteOperation(pParse, 1, iDb);
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  /* Virtual tables must be handled separately */
-  if( IsVirtual(pTab) ){
-    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
-                       pWhere, onError);
-    pWhere = 0;
-    pTabList = 0;
-    goto update_cleanup;
-  }
-#endif
-
   /* Allocate required registers. */
-  regOldRowid = regNewRowid = ++pParse->nMem;
-  if( pTrigger || hasFK ){
-    regOld = pParse->nMem + 1;
+  if( !IsVirtual(pTab) ){
+    regRowSet = ++pParse->nMem;
+    regOldRowid = regNewRowid = ++pParse->nMem;
+    if( chngPk || pTrigger || hasFK ){
+      regOld = pParse->nMem + 1;
+      pParse->nMem += pTab->nCol;
+    }
+    if( chngKey || pTrigger || hasFK ){
+      regNewRowid = ++pParse->nMem;
+    }
+    regNew = pParse->nMem + 1;
     pParse->nMem += pTab->nCol;
   }
-  if( chngRowid || pTrigger || hasFK ){
-    regNewRowid = ++pParse->nMem;
-  }
-  regNew = pParse->nMem + 1;
-  pParse->nMem += pTab->nCol;
 
   /* Start the view context. */
   if( isView ){
@@ -98905,11 +120825,11 @@ SQLITE_PRIVATE void sqlite3Update(
   }
 
   /* If we are trying to update a view, realize that view into
-  ** a ephemeral table.
+  ** an ephemeral table.
   */
 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
   if( isView ){
-    sqlite3MaterializeView(pParse, pTab, pWhere, iCur);
+    sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur);
   }
 #endif
 
@@ -98920,26 +120840,70 @@ SQLITE_PRIVATE void sqlite3Update(
     goto update_cleanup;
   }
 
-  /* Begin the database scan
-  */
-  sqlite3VdbeAddOp2(v, OP_Null, 0, regOldRowid);
-  pWInfo = sqlite3WhereBegin(
-      pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED
-  );
-  if( pWInfo==0 ) goto update_cleanup;
-  okOnePass = pWInfo->okOnePass;
-
-  /* Remember the rowid of every item to be updated.
-  */
-  sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regOldRowid);
-  if( !okOnePass ){
-    regRowSet = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Virtual tables must be handled separately */
+  if( IsVirtual(pTab) ){
+    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
+                       pWhere, onError);
+    goto update_cleanup;
   }
+#endif
 
-  /* End the database scan loop.
+  /* Begin the database scan
   */
-  sqlite3WhereEnd(pWInfo);
+  if( HasRowid(pTab) ){
+    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
+    pWInfo = sqlite3WhereBegin(
+        pParse, pTabList, pWhere, 0, 0,
+            WHERE_ONEPASS_DESIRED | WHERE_SEEK_TABLE, iIdxCur
+    );
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+  
+    /* Remember the rowid of every item to be updated.
+    */
+    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
+    if( !okOnePass ){
+      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+    }
+  
+    /* End the database scan loop.
+    */
+    sqlite3WhereEnd(pWInfo);
+  }else{
+    int iPk;         /* First of nPk memory cells holding PRIMARY KEY value */
+    i16 nPk;         /* Number of components of the PRIMARY KEY */
+    int addrOpen;    /* Address of the OpenEphemeral instruction */
+
+    assert( pPk!=0 );
+    nPk = pPk->nKeyCol;
+    iPk = pParse->nMem+1;
+    pParse->nMem += nPk;
+    regKey = ++pParse->nMem;
+    iEph = pParse->nTab++;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iPk);
+    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
+    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
+                               WHERE_ONEPASS_DESIRED, iIdxCur);
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    for(i=0; i<nPk; i++){
+      assert( pPk->aiColumn[i]>=0 );
+      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
+                                      iPk+i);
+    }
+    if( okOnePass ){
+      sqlite3VdbeChangeToNoop(v, addrOpen);
+      nKey = nPk;
+      regKey = iPk;
+    }else{
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
+                        sqlite3IndexAffinityStr(db, pPk), nPk);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey);
+    }
+    sqlite3WhereEnd(pWInfo);
+  }
 
   /* Initialize the count of updated rows
   */
@@ -98948,6 +120912,7 @@ SQLITE_PRIVATE void sqlite3Update(
     sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
   }
 
+  labelBreak = sqlite3VdbeMakeLabel(v);
   if( !isView ){
     /* 
     ** Open every index that needs updating.  Note that if any
@@ -98955,74 +120920,84 @@ SQLITE_PRIVATE void sqlite3Update(
     ** action, then we need to open all indices because we might need
     ** to be deleting some records.
     */
-    if( !okOnePass ) sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); 
     if( onError==OE_Replace ){
-      openAll = 1;
+      memset(aToOpen, 1, nIdx+1);
     }else{
-      openAll = 0;
       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
         if( pIdx->onError==OE_Replace ){
-          openAll = 1;
+          memset(aToOpen, 1, nIdx+1);
           break;
         }
       }
     }
-    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
-      assert( aRegIdx );
-      if( openAll || aRegIdx[i]>0 ){
-        KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
-        sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, iDb,
-                       (char*)pKey, P4_KEYINFO_HANDOFF);
-        assert( pParse->nTab>iCur+i+1 );
-      }
+    if( okOnePass ){
+      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
+      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
     }
+    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen,
+                               0, 0);
   }
 
   /* Top of the update loop */
   if( okOnePass ){
-    int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid);
-    addr = sqlite3VdbeAddOp0(v, OP_Goto);
-    sqlite3VdbeJumpHere(v, a1);
+    if( aToOpen[iDataCur-iBaseCur] && !isView ){
+      assert( pPk );
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
+      VdbeCoverageNeverTaken(v);
+    }
+    labelContinue = labelBreak;
+    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
+    VdbeCoverageIf(v, pPk==0);
+    VdbeCoverageIf(v, pPk!=0);
+  }else if( pPk ){
+    labelContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
+    addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey);
+    sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
+    VdbeCoverage(v);
   }else{
-    addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid);
+    labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak,
+                             regOldRowid);
+    VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+    VdbeCoverage(v);
   }
 
-  /* Make cursor iCur point to the record that is being updated. If
-  ** this record does not exist for some reason (deleted by a trigger,
-  ** for example, then jump to the next iteration of the RowSet loop.  */
-  sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);
-
   /* If the record number will change, set register regNewRowid to
   ** contain the new value. If the record number is not being modified,
   ** then regNewRowid is the same register as regOldRowid, which is
   ** already populated.  */
-  assert( chngRowid || pTrigger || hasFK || regOldRowid==regNewRowid );
+  assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
   if( chngRowid ){
     sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
-    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid);
+    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
   }
 
-  /* If there are triggers on this table, populate an array of registers 
-  ** with the required old.* column data.  */
-  if( hasFK || pTrigger ){
+  /* Compute the old pre-UPDATE content of the row being changed, if that
+  ** information is needed */
+  if( chngPk || hasFK || pTrigger ){
     u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
     oldmask |= sqlite3TriggerColmask(pParse, 
         pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
     );
     for(i=0; i<pTab->nCol; i++){
-      if( aXRef[i]<0 || oldmask==0xffffffff || (i<32 && (oldmask & (1<<i))) ){
-        sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, i, regOld+i);
+      if( oldmask==0xffffffff
+       || (i<32 && (oldmask & MASKBIT32(i))!=0)
+       || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0
+      ){
+        testcase(  oldmask!=0xffffffff && i==31 );
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
       }
     }
-    if( chngRowid==0 ){
+    if( chngRowid==0 && pPk==0 ){
       sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
     }
   }
 
   /* Populate the array of registers beginning at regNew with the new
-  ** row data. This array is used to check constaints, create the new
+  ** row data. This array is used to check constants, create the new
   ** table and index records, and as the values for any new.* references
   ** made by triggers.
   **
@@ -99044,7 +121019,7 @@ SQLITE_PRIVATE void sqlite3Update(
       j = aXRef[i];
       if( j>=0 ){
         sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
-      }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask&(1<<i)) ){
+      }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
         /* This branch loads the value of a column that will not be changed 
         ** into a register. This is done if there are no BEFORE triggers, or
         ** if there are one or more BEFORE triggers that use this value via
@@ -99052,8 +121027,9 @@ SQLITE_PRIVATE void sqlite3Update(
         */
         testcase( i==31 );
         testcase( i==32 );
-        sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i);
-        sqlite3ColumnDefault(v, pTab, i, regNew+i);
+        sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
       }
     }
   }
@@ -99062,18 +121038,23 @@ SQLITE_PRIVATE void sqlite3Update(
   ** verified. One could argue that this is wrong.
   */
   if( tmask&TRIGGER_BEFORE ){
-    sqlite3VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol);
-    sqlite3TableAffinityStr(v, pTab);
+    sqlite3TableAffinity(v, pTab, regNew);
     sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
-        TRIGGER_BEFORE, pTab, regOldRowid, onError, addr);
+        TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
 
     /* The row-trigger may have deleted the row being updated. In this
     ** case, jump to the next row. No updates or AFTER triggers are 
-    ** required. This behaviour - what happens when the row being updated
+    ** required. This behavior - what happens when the row being updated
     ** is deleted or renamed by a BEFORE trigger - is left undefined in the
     ** documentation.
     */
-    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);
+    if( pPk ){
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);
+      VdbeCoverage(v);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+      VdbeCoverage(v);
+    }
 
     /* If it did not delete it, the row-trigger may still have modified 
     ** some of the columns of the row being updated. Load the values for 
@@ -99082,46 +121063,77 @@ SQLITE_PRIVATE void sqlite3Update(
     */
     for(i=0; i<pTab->nCol; i++){
       if( aXRef[i]<0 && i!=pTab->iPKey ){
-        sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i);
-        sqlite3ColumnDefault(v, pTab, i, regNew+i);
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
       }
     }
   }
 
   if( !isView ){
-    int j1;                       /* Address of jump instruction */
+    int addr1 = 0;        /* Address of jump instruction */
+    int bReplace = 0;     /* True if REPLACE conflict resolution might happen */
 
     /* Do constraint checks. */
-    sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid,
-        aRegIdx, (chngRowid?regOldRowid:0), 1, onError, addr, 0);
+    assert( regOldRowid>0 );
+    sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
+        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,
+        aXRef);
 
     /* Do FK constraint checks. */
     if( hasFK ){
-      sqlite3FkCheck(pParse, pTab, regOldRowid, 0);
+      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
     }
 
     /* Delete the index entries associated with the current record.  */
-    j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid);
-    sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx);
-  
-    /* If changing the record number, delete the old record.  */
-    if( hasFK || chngRowid ){
-      sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0);
+    if( bReplace || chngKey ){
+      if( pPk ){
+        addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
+      }else{
+        addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
+      }
+      VdbeCoverageNeverTaken(v);
+    }
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
+
+    /* If changing the rowid value, or if there are foreign key constraints
+    ** to process, delete the old record. Otherwise, add a noop OP_Delete
+    ** to invoke the pre-update hook.
+    **
+    ** That (regNew==regnewRowid+1) is true is also important for the 
+    ** pre-update hook. If the caller invokes preupdate_new(), the returned
+    ** value is copied from memory cell (regNewRowid+1+iCol), where iCol
+    ** is the column index supplied by the user.
+    */
+    assert( regNew==regNewRowid+1 );
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+    sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
+        OPFLAG_ISUPDATE | ((hasFK || chngKey || pPk!=0) ? 0 : OPFLAG_ISNOOP),
+        regNewRowid
+    );
+    if( !pParse->nested ){
+      sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE);
+    }
+#else
+    if( hasFK || chngKey || pPk!=0 ){
+      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
+    }
+#endif
+    if( bReplace || chngKey ){
+      sqlite3VdbeJumpHere(v, addr1);
     }
-    sqlite3VdbeJumpHere(v, j1);
 
     if( hasFK ){
-      sqlite3FkCheck(pParse, pTab, 0, regNewRowid);
+      sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
     }
   
     /* Insert the new index entries and the new record. */
-    sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, aRegIdx, 1, 0, 0);
+    sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
+                             regNewRowid, aRegIdx, 1, 0, 0);
 
     /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
     ** handle rows (possibly in other tables) that refer via a foreign key
     ** to the row just updated. */ 
     if( hasFK ){
-      sqlite3FkActions(pParse, pTab, pChanges, regOldRowid);
+      sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
     }
   }
 
@@ -99132,22 +121144,29 @@ SQLITE_PRIVATE void sqlite3Update(
   }
 
   sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
-      TRIGGER_AFTER, pTab, regOldRowid, onError, addr);
+      TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
 
   /* Repeat the above with the next record to be updated, until
   ** all record selected by the WHERE clause have been updated.
   */
-  sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
-  sqlite3VdbeJumpHere(v, addr);
+  if( okOnePass ){
+    /* Nothing to do at end-of-loop for a single-pass */
+  }else if( pPk ){
+    sqlite3VdbeResolveLabel(v, labelContinue);
+    sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
+  }else{
+    sqlite3VdbeGoto(v, labelContinue);
+  }
+  sqlite3VdbeResolveLabel(v, labelBreak);
 
   /* Close all tables */
   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
     assert( aRegIdx );
-    if( openAll || aRegIdx[i]>0 ){
-      sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0);
+    if( aToOpen[i+1] ){
+      sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0);
     }
   }
-  sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
+  if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0);
 
   /* Update the sqlite_sequence table by storing the content of the
   ** maximum rowid counter values recorded while inserting into
@@ -99170,15 +121189,14 @@ SQLITE_PRIVATE void sqlite3Update(
 
 update_cleanup:
   sqlite3AuthContextPop(&sContext);
-  sqlite3DbFree(db, aRegIdx);
-  sqlite3DbFree(db, aXRef);
+  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
   sqlite3SrcListDelete(db, pTabList);
   sqlite3ExprListDelete(db, pChanges);
   sqlite3ExprDelete(db, pWhere);
   return;
 }
 /* Make sure "isView" and other macros defined above are undefined. Otherwise
-** thely may interfere with compilation of other functions in this file
+** they may interfere with compilation of other functions in this file
 ** (or in another file, if this file becomes part of the amalgamation).  */
 #ifdef isView
  #undef isView
@@ -99191,21 +121209,23 @@ update_cleanup:
 /*
 ** Generate code for an UPDATE of a virtual table.
 **
-** The strategy is that we create an ephemerial table that contains
+** There are two possible strategies - the default and the special 
+** "onepass" strategy. Onepass is only used if the virtual table 
+** implementation indicates that pWhere may match at most one row.
+**
+** The default strategy is to create an ephemeral table that contains
 ** for each row to be changed:
 **
 **   (A)  The original rowid of that row.
-**   (B)  The revised rowid for the row. (note1)
+**   (B)  The revised rowid for the row.
 **   (C)  The content of every column in the row.
 **
-** Then we loop over this ephemeral table and for each row in
-** the ephermeral table call VUpdate.
-**
-** When finished, drop the ephemeral table.
+** Then loop through the contents of this ephemeral table executing a
+** VUpdate for each row. When finished, drop the ephemeral table.
 **
-** (note1) Actually, if we know in advance that (A) is always the same
-** as (B) we only store (A), then duplicate (A) when pulling
-** it out of the ephemeral table before calling VUpdate.
+** The "onepass" strategy does not use an ephemeral table. Instead, it
+** stores the same values (A, B and C above) in a register array and
+** makes a single invocation of VUpdate.
 */
 static void updateVirtualTable(
   Parse *pParse,       /* The parsing context */
@@ -99218,68 +121238,96 @@ static void updateVirtualTable(
   int onError          /* ON CONFLICT strategy */
 ){
   Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */
-  ExprList *pEList = 0;     /* The result set of the SELECT statement */
-  Select *pSelect = 0;      /* The SELECT statement */
-  Expr *pExpr;              /* Temporary expression */
   int ephemTab;             /* Table holding the result of the SELECT */
   int i;                    /* Loop counter */
-  int addr;                 /* Address of top of loop */
-  int iReg;                 /* First register in set passed to OP_VUpdate */
   sqlite3 *db = pParse->db; /* Database connection */
   const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
-  SelectDest dest;
-
-  /* Construct the SELECT statement that will find the new values for
-  ** all updated rows. 
-  */
-  pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
+  WhereInfo *pWInfo;
+  int nArg = 2 + pTab->nCol;      /* Number of arguments to VUpdate */
+  int regArg;                     /* First register in VUpdate arg array */
+  int regRec;                     /* Register in which to assemble record */
+  int regRowid;                   /* Register for ephem table rowid */
+  int iCsr = pSrc->a[0].iCursor;  /* Cursor used for virtual table scan */
+  int aDummy[2];                  /* Unused arg for sqlite3WhereOkOnePass() */
+  int bOnePass;                   /* True to use onepass strategy */
+  int addr;                       /* Address of OP_OpenEphemeral */
+
+  /* Allocate nArg registers to martial the arguments to VUpdate. Then
+  ** create and open the ephemeral table in which the records created from
+  ** these arguments will be temporarily stored. */
+  assert( v );
+  ephemTab = pParse->nTab++;
+  addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
+  regArg = pParse->nMem + 1;
+  pParse->nMem += nArg;
+  regRec = ++pParse->nMem;
+  regRowid = ++pParse->nMem;
+
+  /* Start scanning the virtual table */
+  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
+  if( pWInfo==0 ) return;
+
+  /* Populate the argument registers. */
+  sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
   if( pRowid ){
-    pEList = sqlite3ExprListAppend(pParse, pEList,
-                                   sqlite3ExprDup(db, pRowid, 0));
+    sqlite3ExprCode(pParse, pRowid, regArg+1);
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
   }
-  assert( pTab->iPKey<0 );
   for(i=0; i<pTab->nCol; i++){
     if( aXRef[i]>=0 ){
-      pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
+      sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
     }else{
-      pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);
+      sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
     }
-    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
   }
-  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
-  
-  /* Create the ephemeral table into which the update results will
-  ** be stored.
-  */
-  assert( v );
-  ephemTab = pParse->nTab++;
-  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
-  sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
 
-  /* fill the ephemeral table 
-  */
-  sqlite3SelectDestInit(&dest, SRT_Table, ephemTab);
-  sqlite3Select(pParse, pSelect, &dest);
+  bOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);
 
-  /* Generate code to scan the ephemeral table and call VUpdate. */
-  iReg = ++pParse->nMem;
-  pParse->nMem += pTab->nCol+1;
-  addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0);
-  sqlite3VdbeAddOp3(v, OP_Column,  ephemTab, 0, iReg);
-  sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);
-  for(i=0; i<pTab->nCol; i++){
-    sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
+  if( bOnePass ){
+    /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
+    ** above. Also, if this is a top-level parse (not a trigger), clear the
+    ** multi-write flag so that the VM does not open a statement journal */
+    sqlite3VdbeChangeToNoop(v, addr);
+    if( sqlite3IsToplevel(pParse) ){
+      pParse->isMultiWrite = 0;
+    }
+  }else{
+    /* Create a record from the argument register contents and insert it into
+    ** the ephemeral table. */
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);
+  }
+
+
+  if( bOnePass==0 ){
+    /* End the virtual table scan */
+    sqlite3WhereEnd(pWInfo);
+
+    /* Begin scannning through the ephemeral table. */
+    addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);
+
+    /* Extract arguments from the current row of the ephemeral table and 
+    ** invoke the VUpdate method.  */
+    for(i=0; i<nArg; i++){
+      sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);
+    }
   }
   sqlite3VtabMakeWritable(pParse, pTab);
-  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB);
+  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
   sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
   sqlite3MayAbort(pParse);
-  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1);
-  sqlite3VdbeJumpHere(v, addr);
-  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
 
-  /* Cleanup */
-  sqlite3SelectDelete(db, pSelect);  
+  /* End of the ephemeral table scan. Or, if using the onepass strategy,
+  ** jump to here if the scan visited zero rows. */
+  if( bOnePass==0 ){
+    sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr);
+    sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
+  }else{
+    sqlite3WhereEnd(pWInfo);
+  }
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -99301,6 +121349,8 @@ static void updateVirtualTable(
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 */
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
 
 #if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
 /*
@@ -99323,7 +121373,7 @@ static int execSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
   sqlite3_stmt *pStmt;
   VVA_ONLY( int rc; )
   if( !zSql ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   if( SQLITE_OK!=sqlite3_prepare(db, zSql, -1, &pStmt, 0) ){
     sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
@@ -99357,19 +121407,40 @@ static int execExecSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
 }
 
 /*
-** The non-standard VACUUM command is used to clean up the database,
+** The VACUUM command is used to clean up the database,
 ** collapse free space, etc.  It is modelled after the VACUUM command
-** in PostgreSQL.
-**
-** In version 1.0.x of SQLite, the VACUUM command would call
-** gdbm_reorganize() on all the database tables.  But beginning
-** with 2.0.0, SQLite no longer uses GDBM so this command has
-** become a no-op.
+** in PostgreSQL.  The VACUUM command works as follows:
+**
+**   (1)  Create a new transient database file
+**   (2)  Copy all content from the database being vacuumed into
+**        the new transient database file
+**   (3)  Copy content from the transient database back into the
+**        original database.
+**
+** The transient database requires temporary disk space approximately
+** equal to the size of the original database.  The copy operation of
+** step (3) requires additional temporary disk space approximately equal
+** to the size of the original database for the rollback journal.
+** Hence, temporary disk space that is approximately 2x the size of the
+** original database is required.  Every page of the database is written
+** approximately 3 times:  Once for step (2) and twice for step (3).
+** Two writes per page are required in step (3) because the original
+** database content must be written into the rollback journal prior to
+** overwriting the database with the vacuumed content.
+**
+** Only 1x temporary space and only 1x writes would be required if
+** the copy of step (3) were replaced by deleting the original database
+** and renaming the transient database as the original.  But that will
+** not work if other processes are attached to the original database.
+** And a power loss in between deleting the original and renaming the
+** transient would cause the database file to appear to be deleted
+** following reboot.
 */
 SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse){
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( v ){
     sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
+    sqlite3VdbeUsesBtree(v, 0);
   }
   return;
 }
@@ -99385,7 +121456,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   int saved_flags;        /* Saved value of the db->flags */
   int saved_nChange;      /* Saved value of db->nChange */
   int saved_nTotalChange; /* Saved value of db->nTotalChange */
-  void (*saved_xTrace)(void*,const char*);  /* Saved db->xTrace */
+  u8 saved_mTrace;        /* Saved trace settings */
   Db *pDb = 0;            /* Database to detach at end of vacuum */
   int isMemDb;            /* True if vacuuming a :memory: database */
   int nRes;               /* Bytes of reserved space at the end of each page */
@@ -99395,7 +121466,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
     sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
     return SQLITE_ERROR;
   }
-  if( db->activeVdbeCnt>1 ){
+  if( db->nVdbeActive>1 ){
     sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");
     return SQLITE_ERROR;
   }
@@ -99406,10 +121477,10 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   saved_flags = db->flags;
   saved_nChange = db->nChange;
   saved_nTotalChange = db->nTotalChange;
-  saved_xTrace = db->xTrace;
+  saved_mTrace = db->mTrace;
   db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks | SQLITE_PreferBuiltin;
   db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder);
-  db->xTrace = 0;
+  db->mTrace = 0;
 
   pMain = db->aDb[0].pBt;
   isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
@@ -99448,7 +121519,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** cause problems for the call to BtreeSetPageSize() below.  */
   sqlite3BtreeCommit(pTemp);
 
-  nRes = sqlite3BtreeGetReserve(pMain);
+  nRes = sqlite3BtreeGetOptimalReserve(pMain);
 
   /* A VACUUM cannot change the pagesize of an encrypted database. */
 #ifdef SQLITE_HAS_CODEC
@@ -99461,6 +121532,20 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   }
 #endif
 
+  sqlite3BtreeSetCacheSize(pTemp, db->aDb[0].pSchema->cache_size);
+  sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain,0));
+  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Begin a transaction and take an exclusive lock on the main database
+  ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
+  ** to ensure that we do not try to change the page-size on a WAL database.
+  */
+  rc = execSql(db, pzErrMsg, "BEGIN;");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = sqlite3BtreeBeginTrans(pMain, 2);
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
   /* Do not attempt to change the page size for a WAL database */
   if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
                                                ==PAGER_JOURNALMODE_WAL ){
@@ -99471,11 +121556,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
    || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
    || NEVER(db->mallocFailed)
   ){
-    rc = SQLITE_NOMEM;
-    goto end_of_vacuum;
-  }
-  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
-  if( rc!=SQLITE_OK ){
+    rc = SQLITE_NOMEM_BKPT;
     goto end_of_vacuum;
   }
 
@@ -99484,17 +121565,13 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
                                            sqlite3BtreeGetAutoVacuum(pMain));
 #endif
 
-  /* Begin a transaction */
-  rc = execSql(db, pzErrMsg, "BEGIN EXCLUSIVE;");
-  if( rc!=SQLITE_OK ) goto end_of_vacuum;
-
   /* Query the schema of the main database. Create a mirror schema
   ** in the temporary database.
   */
   rc = execExecSql(db, pzErrMsg,
       "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
       "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
-      "   AND rootpage>0"
+      "   AND coalesce(rootpage,1)>0"
   );
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
   rc = execExecSql(db, pzErrMsg,
@@ -99510,13 +121587,17 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
   ** the contents to the temporary database.
   */
+  assert( (db->flags & SQLITE_Vacuum)==0 );
+  db->flags |= SQLITE_Vacuum;
   rc = execExecSql(db, pzErrMsg,
       "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
       "|| ' SELECT * FROM main.' || quote(name) || ';'"
       "FROM main.sqlite_master "
       "WHERE type = 'table' AND name!='sqlite_sequence' "
-      "  AND rootpage>0"
+      "  AND coalesce(rootpage,1)>0"
   );
+  assert( (db->flags & SQLITE_Vacuum)!=0 );
+  db->flags &= ~SQLITE_Vacuum;
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
 
   /* Copy over the sequence table
@@ -99569,6 +121650,7 @@ SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
        BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */
        BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */
        BTREE_USER_VERSION,       0,  /* Preserve the user version */
+       BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
     };
 
     assert( 1==sqlite3BtreeIsInTrans(pTemp) );
@@ -99600,7 +121682,7 @@ end_of_vacuum:
   db->flags = saved_flags;
   db->nChange = saved_nChange;
   db->nTotalChange = saved_nTotalChange;
-  db->xTrace = saved_xTrace;
+  db->mTrace = saved_mTrace;
   sqlite3BtreeSetPageSize(pMain, -1, -1, 1);
 
   /* Currently there is an SQL level transaction open on the vacuum
@@ -99620,7 +121702,7 @@ end_of_vacuum:
 
   /* This both clears the schemas and reduces the size of the db->aDb[]
   ** array. */ 
-  sqlite3ResetInternalSchema(db, -1);
+  sqlite3ResetAllSchemasOfConnection(db);
 
   return rc;
 }
@@ -99643,6 +121725,7 @@ end_of_vacuum:
 ** This file contains code used to help implement virtual tables.
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
+/* #include "sqliteInt.h" */
 
 /*
 ** Before a virtual table xCreate() or xConnect() method is invoked, the
@@ -99652,8 +121735,10 @@ end_of_vacuum:
 ** are invoked only from within xCreate and xConnect methods.
 */
 struct VtabCtx {
-  Table *pTab;
-  VTable *pVTable;
+  VTable *pVTable;    /* The virtual table being constructed */
+  Table *pTab;        /* The Table object to which the virtual table belongs */
+  VtabCtx *pPrior;    /* Parent context (if any) */
+  int bDeclared;      /* True after sqlite3_declare_vtab() is called */
 };
 
 /*
@@ -99668,33 +121753,36 @@ static int createModule(
   void *pAux,                     /* Context pointer for xCreate/xConnect */
   void (*xDestroy)(void *)        /* Module destructor function */
 ){
-  int rc, nName;
-  Module *pMod;
+  int rc = SQLITE_OK;
+  int nName;
 
   sqlite3_mutex_enter(db->mutex);
   nName = sqlite3Strlen30(zName);
-  pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
-  if( pMod ){
-    Module *pDel;
-    char *zCopy = (char *)(&pMod[1]);
-    memcpy(zCopy, zName, nName+1);
-    pMod->zName = zCopy;
-    pMod->pModule = pModule;
-    pMod->pAux = pAux;
-    pMod->xDestroy = xDestroy;
-    pDel = (Module *)sqlite3HashInsert(&db->aModule, zCopy, nName, (void*)pMod);
-    if( pDel && pDel->xDestroy ){
-      sqlite3ResetInternalSchema(db, -1);
-      pDel->xDestroy(pDel->pAux);
-    }
-    sqlite3DbFree(db, pDel);
-    if( pDel==pMod ){
-      db->mallocFailed = 1;
-    }
-  }else if( xDestroy ){
-    xDestroy(pAux);
-  }
-  rc = sqlite3ApiExit(db, SQLITE_OK);
+  if( sqlite3HashFind(&db->aModule, zName) ){
+    rc = SQLITE_MISUSE_BKPT;
+  }else{
+    Module *pMod;
+    pMod = (Module *)sqlite3DbMallocRawNN(db, sizeof(Module) + nName + 1);
+    if( pMod ){
+      Module *pDel;
+      char *zCopy = (char *)(&pMod[1]);
+      memcpy(zCopy, zName, nName+1);
+      pMod->zName = zCopy;
+      pMod->pModule = pModule;
+      pMod->pAux = pAux;
+      pMod->xDestroy = xDestroy;
+      pMod->pEpoTab = 0;
+      pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
+      assert( pDel==0 || pDel==pMod );
+      if( pDel ){
+        sqlite3OomFault(db);
+        sqlite3DbFree(db, pDel);
+      }
+    }
+  }
+  rc = sqlite3ApiExit(db, rc);
+  if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
+
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
@@ -99703,25 +121791,31 @@ static int createModule(
 /*
 ** External API function used to create a new virtual-table module.
 */
-SQLITE_API int sqlite3_create_module(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
   sqlite3 *db,                    /* Database in which module is registered */
   const char *zName,              /* Name assigned to this module */
   const sqlite3_module *pModule,  /* The definition of the module */
   void *pAux                      /* Context pointer for xCreate/xConnect */
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   return createModule(db, zName, pModule, pAux, 0);
 }
 
 /*
 ** External API function used to create a new virtual-table module.
 */
-SQLITE_API int sqlite3_create_module_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
   sqlite3 *db,                    /* Database in which module is registered */
   const char *zName,              /* Name assigned to this module */
   const sqlite3_module *pModule,  /* The definition of the module */
   void *pAux,                     /* Context pointer for xCreate/xConnect */
   void (*xDestroy)(void *)        /* Module destructor function */
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   return createModule(db, zName, pModule, pAux, xDestroy);
 }
 
@@ -99759,7 +121853,7 @@ SQLITE_PRIVATE void sqlite3VtabUnlock(VTable *pVTab){
 
   assert( db );
   assert( pVTab->nRef>0 );
-  assert( sqlite3SafetyCheckOk(db) );
+  assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE );
 
   pVTab->nRef--;
   if( pVTab->nRef==0 ){
@@ -99810,6 +121904,31 @@ static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){
   return pRet;
 }
 
+/*
+** Table *p is a virtual table. This function removes the VTable object
+** for table *p associated with database connection db from the linked
+** list in p->pVTab. It also decrements the VTable ref count. This is
+** used when closing database connection db to free all of its VTable
+** objects without disturbing the rest of the Schema object (which may
+** be being used by other shared-cache connections).
+*/
+SQLITE_PRIVATE void sqlite3VtabDisconnect(sqlite3 *db, Table *p){
+  VTable **ppVTab;
+
+  assert( IsVirtual(p) );
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){
+    if( (*ppVTab)->db==db  ){
+      VTable *pVTab = *ppVTab;
+      *ppVTab = pVTab->pNext;
+      sqlite3VtabUnlock(pVTab);
+      break;
+    }
+  }
+}
+
 
 /*
 ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list.
@@ -99867,7 +121986,7 @@ SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){
   if( p->azModuleArg ){
     int i;
     for(i=0; i<p->nModuleArg; i++){
-      sqlite3DbFree(db, p->azModuleArg[i]);
+      if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]);
     }
     sqlite3DbFree(db, p->azModuleArg);
   }
@@ -99880,23 +121999,17 @@ SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){
 ** deleted.
 */
 static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){
-  int i = pTable->nModuleArg++;
-  int nBytes = sizeof(char *)*(1+pTable->nModuleArg);
+  int nBytes = sizeof(char *)*(2+pTable->nModuleArg);
   char **azModuleArg;
   azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
   if( azModuleArg==0 ){
-    int j;
-    for(j=0; j<i; j++){
-      sqlite3DbFree(db, pTable->azModuleArg[j]);
-    }
     sqlite3DbFree(db, zArg);
-    sqlite3DbFree(db, pTable->azModuleArg);
-    pTable->nModuleArg = 0;
   }else{
+    int i = pTable->nModuleArg++;
     azModuleArg[i] = zArg;
     azModuleArg[i+1] = 0;
+    pTable->azModuleArg = azModuleArg;
   }
-  pTable->azModuleArg = azModuleArg;
 }
 
 /*
@@ -99908,13 +122021,14 @@ SQLITE_PRIVATE void sqlite3VtabBeginParse(
   Parse *pParse,        /* Parsing context */
   Token *pName1,        /* Name of new table, or database name */
   Token *pName2,        /* Name of new table or NULL */
-  Token *pModuleName    /* Name of the module for the virtual table */
+  Token *pModuleName,   /* Name of the module for the virtual table */
+  int ifNotExists       /* No error if the table already exists */
 ){
   int iDb;              /* The database the table is being created in */
   Table *pTable;        /* The new virtual table */
   sqlite3 *db;          /* Database connection */
 
-  sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, 0);
+  sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists);
   pTable = pParse->pNewTable;
   if( pTable==0 ) return;
   assert( 0==pTable->pIndex );
@@ -99926,9 +122040,14 @@ SQLITE_PRIVATE void sqlite3VtabBeginParse(
   pTable->tabFlags |= TF_Virtual;
   pTable->nModuleArg = 0;
   addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
-  addModuleArgument(db, pTable, sqlite3DbStrDup(db, db->aDb[iDb].zName));
+  addModuleArgument(db, pTable, 0);
   addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
-  pParse->sNameToken.n = (int)(&pModuleName->z[pModuleName->n] - pName1->z);
+  assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)
+       || (pParse->sNameToken.z==pName1->z && pName2->z==0)
+  );
+  pParse->sNameToken.n = (int)(
+      &pModuleName->z[pModuleName->n] - pParse->sNameToken.z
+  );
 
 #ifndef SQLITE_OMIT_AUTHORIZATION
   /* Creating a virtual table invokes the authorization callback twice.
@@ -99949,7 +122068,7 @@ SQLITE_PRIVATE void sqlite3VtabBeginParse(
 ** virtual table currently under construction in pParse->pTable.
 */
 static void addArgumentToVtab(Parse *pParse){
-  if( pParse->sArg.z && ALWAYS(pParse->pNewTable) ){
+  if( pParse->sArg.z && pParse->pNewTable ){
     const char *z = (const char*)pParse->sArg.z;
     int n = pParse->sArg.n;
     sqlite3 *db = pParse->db;
@@ -99980,6 +122099,7 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     char *zStmt;
     char *zWhere;
     int iDb;
+    int iReg;
     Vdbe *v;
 
     /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
@@ -100011,11 +122131,13 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     v = sqlite3GetVdbe(pParse);
     sqlite3ChangeCookie(pParse, iDb);
 
-    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+    sqlite3VdbeAddOp0(v, OP_Expire);
     zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
     sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
-    sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, 
-                         pTab->zName, sqlite3Strlen30(pTab->zName) + 1);
+
+    iReg = ++pParse->nMem;
+    sqlite3VdbeLoadString(v, iReg, pTab->zName);
+    sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
   }
 
   /* If we are rereading the sqlite_master table create the in-memory
@@ -100027,11 +122149,10 @@ SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     Table *pOld;
     Schema *pSchema = pTab->pSchema;
     const char *zName = pTab->zName;
-    int nName = sqlite3Strlen30(zName);
     assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
-    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
+    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
     if( pOld ){
-      db->mallocFailed = 1;
+      sqlite3OomFault(db);
       assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
       return;
     }
@@ -100059,7 +122180,7 @@ SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse *pParse, Token *p){
     pArg->z = p->z;
     pArg->n = p->n;
   }else{
-    assert(pArg->z < p->z);
+    assert(pArg->z <= p->z);
     pArg->n = (int)(&p->z[p->n] - pArg->z);
   }
 }
@@ -100082,29 +122203,48 @@ static int vtabCallConstructor(
   const char *const*azArg = (const char *const*)pTab->azModuleArg;
   int nArg = pTab->nModuleArg;
   char *zErr = 0;
-  char *zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
+  char *zModuleName;
+  int iDb;
+  VtabCtx *pCtx;
+
+  /* Check that the virtual-table is not already being initialized */
+  for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){
+    if( pCtx->pTab==pTab ){
+      *pzErr = sqlite3MPrintf(db, 
+          "vtable constructor called recursively: %s", pTab->zName
+      );
+      return SQLITE_LOCKED;
+    }
+  }
 
+  zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
   if( !zModuleName ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   pVTable = sqlite3DbMallocZero(db, sizeof(VTable));
   if( !pVTable ){
     sqlite3DbFree(db, zModuleName);
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   pVTable->db = db;
   pVTable->pMod = pMod;
 
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  pTab->azModuleArg[1] = db->aDb[iDb].zName;
+
   /* Invoke the virtual table constructor */
   assert( &db->pVtabCtx );
   assert( xConstruct );
   sCtx.pTab = pTab;
   sCtx.pVTable = pVTable;
+  sCtx.pPrior = db->pVtabCtx;
+  sCtx.bDeclared = 0;
   db->pVtabCtx = &sCtx;
   rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
-  db->pVtabCtx = 0;
-  if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+  db->pVtabCtx = sCtx.pPrior;
+  if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
+  assert( sCtx.pTab==pTab );
 
   if( SQLITE_OK!=rc ){
     if( zErr==0 ){
@@ -100117,37 +122257,36 @@ static int vtabCallConstructor(
   }else if( ALWAYS(pVTable->pVtab) ){
     /* Justification of ALWAYS():  A correct vtab constructor must allocate
     ** the sqlite3_vtab object if successful.  */
+    memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));
     pVTable->pVtab->pModule = pMod->pModule;
     pVTable->nRef = 1;
-    if( sCtx.pTab ){
+    if( sCtx.bDeclared==0 ){
       const char *zFormat = "vtable constructor did not declare schema: %s";
       *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
       sqlite3VtabUnlock(pVTable);
       rc = SQLITE_ERROR;
     }else{
       int iCol;
+      u8 oooHidden = 0;
       /* If everything went according to plan, link the new VTable structure
       ** into the linked list headed by pTab->pVTable. Then loop through the 
       ** columns of the table to see if any of them contain the token "hidden".
-      ** If so, set the Column.isHidden flag and remove the token from
+      ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from
       ** the type string.  */
       pVTable->pNext = pTab->pVTable;
       pTab->pVTable = pVTable;
 
       for(iCol=0; iCol<pTab->nCol; iCol++){
-        char *zType = pTab->aCol[iCol].zType;
+        char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");
         int nType;
         int i = 0;
-        if( !zType ) continue;
         nType = sqlite3Strlen30(zType);
-        if( sqlite3StrNICmp("hidden", zType, 6)||(zType[6] && zType[6]!=' ') ){
-          for(i=0; i<nType; i++){
-            if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7))
-             && (zType[i+7]=='\0' || zType[i+7]==' ')
-            ){
-              i++;
-              break;
-            }
+        for(i=0; i<nType; i++){
+          if( 0==sqlite3StrNICmp("hidden", &zType[i], 6)
+           && (i==0 || zType[i-1]==' ')
+           && (zType[i+6]=='\0' || zType[i+6]==' ')
+          ){
+            break;
           }
         }
         if( i<nType ){
@@ -100160,7 +122299,10 @@ static int vtabCallConstructor(
             assert(zType[i-1]==' ');
             zType[i-1] = '\0';
           }
-          pTab->aCol[iCol].isHidden = 1;
+          pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN;
+          oooHidden = TF_OOOHidden;
+        }else{
+          pTab->tabFlags |= oooHidden;
         }
       }
     }
@@ -100190,7 +122332,7 @@ SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
 
   /* Locate the required virtual table module */
   zMod = pTab->azModuleArg[0];
-  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod, sqlite3Strlen30(zMod));
+  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
 
   if( !pMod ){
     const char *zModule = pTab->azModuleArg[0];
@@ -100220,7 +122362,7 @@ static int growVTrans(sqlite3 *db){
     int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR);
     aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
     if( !aVTrans ){
-      return SQLITE_NOMEM;
+      return SQLITE_NOMEM_BKPT;
     }
     memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
     db->aVTrans = aVTrans;
@@ -100258,13 +122400,13 @@ SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab,
 
   /* Locate the required virtual table module */
   zMod = pTab->azModuleArg[0];
-  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod, sqlite3Strlen30(zMod));
+  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
 
   /* If the module has been registered and includes a Create method, 
   ** invoke it now. If the module has not been registered, return an 
   ** error. Otherwise, do nothing.
   */
-  if( !pMod ){
+  if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
     *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
     rc = SQLITE_ERROR;
   }else{
@@ -100288,24 +122430,31 @@ SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab,
 ** valid to call this function from within the xCreate() or xConnect() of a
 ** virtual table module.
 */
-SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
+SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
+  VtabCtx *pCtx;
   Parse *pParse;
-
   int rc = SQLITE_OK;
   Table *pTab;
   char *zErr = 0;
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
-  if( !db->pVtabCtx || !(pTab = db->pVtabCtx->pTab) ){
-    sqlite3Error(db, SQLITE_MISUSE, 0);
+  pCtx = db->pVtabCtx;
+  if( !pCtx || pCtx->bDeclared ){
+    sqlite3Error(db, SQLITE_MISUSE);
     sqlite3_mutex_leave(db->mutex);
     return SQLITE_MISUSE_BKPT;
   }
+  pTab = pCtx->pTab;
   assert( (pTab->tabFlags & TF_Virtual)!=0 );
 
   pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
   if( pParse==0 ){
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }else{
     pParse->declareVtab = 1;
     pParse->db = db;
@@ -100318,14 +122467,28 @@ SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
      && (pParse->pNewTable->tabFlags & TF_Virtual)==0
     ){
       if( !pTab->aCol ){
-        pTab->aCol = pParse->pNewTable->aCol;
-        pTab->nCol = pParse->pNewTable->nCol;
-        pParse->pNewTable->nCol = 0;
-        pParse->pNewTable->aCol = 0;
+        Table *pNew = pParse->pNewTable;
+        Index *pIdx;
+        pTab->aCol = pNew->aCol;
+        pTab->nCol = pNew->nCol;
+        pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
+        pNew->nCol = 0;
+        pNew->aCol = 0;
+        assert( pTab->pIndex==0 );
+        if( !HasRowid(pNew) && pCtx->pVTable->pMod->pModule->xUpdate!=0 ){
+          rc = SQLITE_ERROR;
+        }
+        pIdx = pNew->pIndex;
+        if( pIdx ){
+          assert( pIdx->pNext==0 );
+          pTab->pIndex = pIdx;
+          pNew->pIndex = 0;
+          pIdx->pTable = pTab;
+        }
       }
-      db->pVtabCtx->pTab = 0;
+      pCtx->bDeclared = 1;
     }else{
-      sqlite3Error(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
+      sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
       sqlite3DbFree(db, zErr);
       rc = SQLITE_ERROR;
     }
@@ -100335,6 +122498,7 @@ SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
       sqlite3VdbeFinalize(pParse->pVdbe);
     }
     sqlite3DeleteTable(db, pParse->pNewTable);
+    sqlite3ParserReset(pParse);
     sqlite3StackFree(db, pParse);
   }
 
@@ -100356,12 +122520,19 @@ SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab
   Table *pTab;
 
   pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
-  if( ALWAYS(pTab!=0 && pTab->pVTable!=0) ){
-    VTable *p = vtabDisconnectAll(db, pTab);
-
-    assert( rc==SQLITE_OK );
-    rc = p->pMod->pModule->xDestroy(p->pVtab);
-
+  if( pTab!=0 && ALWAYS(pTab->pVTable!=0) ){
+    VTable *p;
+    int (*xDestroy)(sqlite3_vtab *);
+    for(p=pTab->pVTable; p; p=p->pNext){
+      assert( p->pVtab );
+      if( p->pVtab->nRef>0 ){
+        return SQLITE_LOCKED;
+      }
+    }
+    p = vtabDisconnectAll(db, pTab);
+    xDestroy = p->pMod->pModule->xDestroy;
+    assert( xDestroy!=0 );  /* Checked before the virtual table is created */
+    rc = xDestroy(p->pVtab);
     /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */
     if( rc==SQLITE_OK ){
       assert( pTab->pVTable==p && p->pNext==0 );
@@ -100385,8 +122556,10 @@ SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab
 static void callFinaliser(sqlite3 *db, int offset){
   int i;
   if( db->aVTrans ){
+    VTable **aVTrans = db->aVTrans;
+    db->aVTrans = 0;
     for(i=0; i<db->nVTrans; i++){
-      VTable *pVTab = db->aVTrans[i];
+      VTable *pVTab = aVTrans[i];
       sqlite3_vtab *p = pVTab->pVtab;
       if( p ){
         int (*x)(sqlite3_vtab *);
@@ -100396,9 +122569,8 @@ static void callFinaliser(sqlite3 *db, int offset){
       pVTab->iSavepoint = 0;
       sqlite3VtabUnlock(pVTab);
     }
-    sqlite3DbFree(db, db->aVTrans);
+    sqlite3DbFree(db, aVTrans);
     db->nVTrans = 0;
-    db->aVTrans = 0;
   }
 }
 
@@ -100407,10 +122579,9 @@ static void callFinaliser(sqlite3 *db, int offset){
 ** array. Return the error code for the first error that occurs, or
 ** SQLITE_OK if all xSync operations are successful.
 **
-** Set *pzErrmsg to point to a buffer that should be released using 
-** sqlite3DbFree() containing an error message, if one is available.
+** If an error message is available, leave it in p->zErrMsg.
 */
-SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, char **pzErrmsg){
+SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, Vdbe *p){
   int i;
   int rc = SQLITE_OK;
   VTable **aVTrans = db->aVTrans;
@@ -100421,9 +122592,7 @@ SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, char **pzErrmsg){
     sqlite3_vtab *pVtab = aVTrans[i]->pVtab;
     if( pVtab && (x = pVtab->pModule->xSync)!=0 ){
       rc = x(pVtab);
-      sqlite3DbFree(db, *pzErrmsg);
-      *pzErrmsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-      sqlite3_free(pVtab->zErrMsg);
+      sqlite3VtabImportErrmsg(p, pVtab);
     }
   }
   db->aVTrans = aVTrans;
@@ -100489,7 +122658,12 @@ SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){
     if( rc==SQLITE_OK ){
       rc = pModule->xBegin(pVTab->pVtab);
       if( rc==SQLITE_OK ){
+        int iSvpt = db->nStatement + db->nSavepoint;
         addToVTrans(db, pVTab);
+        if( iSvpt && pModule->xSavepoint ){
+          pVTab->iSavepoint = iSvpt;
+          rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1);
+        }
       }
     }
   }
@@ -100515,7 +122689,7 @@ SQLITE_PRIVATE int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
   int rc = SQLITE_OK;
 
   assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );
-  assert( iSavepoint>=0 );
+  assert( iSavepoint>=-1 );
   if( db->aVTrans ){
     int i;
     for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
@@ -100566,7 +122740,7 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
   Table *pTab;
   sqlite3_vtab *pVtab;
   sqlite3_module *pMod;
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
   void *pArg = 0;
   FuncDef *pNew;
   int rc = 0;
@@ -100594,7 +122768,7 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
     for(z=(unsigned char*)zLowerName; *z; z++){
       *z = sqlite3UpperToLower[*z];
     }
-    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
+    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xSFunc, &pArg);
     sqlite3DbFree(db, zLowerName);
   }
   if( rc==0 ){
@@ -100609,11 +122783,11 @@ SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
     return pDef;
   }
   *pNew = *pDef;
-  pNew->zName = (char *)&pNew[1];
-  memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1);
-  pNew->xFunc = xFunc;
+  pNew->zName = (const char*)&pNew[1];
+  memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1);
+  pNew->xSFunc = xSFunc;
   pNew->pUserData = pArg;
-  pNew->flags |= SQLITE_FUNC_EPHEM;
+  pNew->funcFlags |= SQLITE_FUNC_EPHEM;
   return pNew;
 }
 
@@ -100633,12 +122807,76 @@ SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
     if( pTab==pToplevel->apVtabLock[i] ) return;
   }
   n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
-  apVtabLock = sqlite3_realloc(pToplevel->apVtabLock, n);
+  apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n);
   if( apVtabLock ){
     pToplevel->apVtabLock = apVtabLock;
     pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
   }else{
-    pToplevel->db->mallocFailed = 1;
+    sqlite3OomFault(pToplevel->db);
+  }
+}
+
+/*
+** Check to see if virtual table module pMod can be have an eponymous
+** virtual table instance.  If it can, create one if one does not already
+** exist. Return non-zero if the eponymous virtual table instance exists
+** when this routine returns, and return zero if it does not exist.
+**
+** An eponymous virtual table instance is one that is named after its
+** module, and more importantly, does not require a CREATE VIRTUAL TABLE
+** statement in order to come into existance.  Eponymous virtual table
+** instances always exist.  They cannot be DROP-ed.
+**
+** Any virtual table module for which xConnect and xCreate are the same
+** method can have an eponymous virtual table instance.
+*/
+SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
+  const sqlite3_module *pModule = pMod->pModule;
+  Table *pTab;
+  char *zErr = 0;
+  int rc;
+  sqlite3 *db = pParse->db;
+  if( pMod->pEpoTab ) return 1;
+  if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
+  pTab = sqlite3DbMallocZero(db, sizeof(Table));
+  if( pTab==0 ) return 0;
+  pTab->zName = sqlite3DbStrDup(db, pMod->zName);
+  if( pTab->zName==0 ){
+    sqlite3DbFree(db, pTab);
+    return 0;
+  }
+  pMod->pEpoTab = pTab;
+  pTab->nRef = 1;
+  pTab->pSchema = db->aDb[0].pSchema;
+  pTab->tabFlags |= TF_Virtual;
+  pTab->nModuleArg = 0;
+  pTab->iPKey = -1;
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  addModuleArgument(db, pTab, 0);
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
+  if( rc ){
+    sqlite3ErrorMsg(pParse, "%s", zErr);
+    sqlite3DbFree(db, zErr);
+    sqlite3VtabEponymousTableClear(db, pMod);
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Erase the eponymous virtual table instance associated with
+** virtual table module pMod, if it exists.
+*/
+SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){
+  Table *pTab = pMod->pEpoTab;
+  if( pTab!=0 ){
+    /* Mark the table as Ephemeral prior to deleting it, so that the
+    ** sqlite3DeleteTable() routine will know that it is not stored in 
+    ** the schema. */
+    pTab->tabFlags |= TF_Ephemeral;
+    sqlite3DeleteTable(db, pTab);
+    pMod->pEpoTab = 0;
   }
 }
 
@@ -100649,10 +122887,13 @@ SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
 ** The results of this routine are undefined unless it is called from
 ** within an xUpdate method.
 */
-SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *db){
   static const unsigned char aMap[] = { 
     SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 
   };
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
   assert( OE_Ignore==4 && OE_Replace==5 );
   assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
@@ -100664,12 +122905,14 @@ SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *db){
 ** the SQLite core with additional information about the behavior
 ** of the virtual table being implemented.
 */
-SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
+SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3 *db, int op, ...){
   va_list ap;
   int rc = SQLITE_OK;
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
-
   va_start(ap, op);
   switch( op ){
     case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
@@ -100688,7 +122931,7 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
   }
   va_end(ap);
 
-  if( rc!=SQLITE_OK ) sqlite3Error(db, rc, 0);
+  if( rc!=SQLITE_OK ) sqlite3Error(db, rc);
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
@@ -100696,9 +122939,9 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 /************** End of vtab.c ************************************************/
-/************** Begin file where.c *******************************************/
+/************** Begin file wherecode.c ***************************************/
 /*
-** 2001 September 15
+** 2015-06-06
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -100709,33 +122952,208 @@ SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){
 **
 *************************************************************************
 ** This module contains C code that generates VDBE code used to process
-** the WHERE clause of SQL statements.  This module is responsible for
-** generating the code that loops through a table looking for applicable
-** rows.  Indices are selected and used to speed the search when doing
-** so is applicable.  Because this module is responsible for selecting
-** indices, you might also think of this module as the "query optimizer".
+** the WHERE clause of SQL statements.
+**
+** This file was split off from where.c on 2015-06-06 in order to reduce the
+** size of where.c and make it easier to edit.  This file contains the routines
+** that actually generate the bulk of the WHERE loop code.  The original where.c
+** file retains the code that does query planning and analysis.
+*/
+/* #include "sqliteInt.h" */
+/************** Include whereInt.h in the middle of wherecode.c **************/
+/************** Begin file whereInt.h ****************************************/
+/*
+** 2013-11-12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains structure and macro definitions for the query
+** planner logic in "where.c".  These definitions are broken out into
+** a separate source file for easier editing.
 */
-
 
 /*
 ** Trace output macros
 */
 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
-SQLITE_PRIVATE int sqlite3WhereTrace = 0;
+/***/ int sqlite3WhereTrace;
 #endif
-#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
-# define WHERETRACE(X)  if(sqlite3WhereTrace) sqlite3DebugPrintf X
+#if defined(SQLITE_DEBUG) \
+    && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
+# define WHERETRACE(K,X)  if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X
+# define WHERETRACE_ENABLED 1
 #else
-# define WHERETRACE(X)
+# define WHERETRACE(K,X)
 #endif
 
-/* Forward reference
+/* Forward references
 */
 typedef struct WhereClause WhereClause;
 typedef struct WhereMaskSet WhereMaskSet;
 typedef struct WhereOrInfo WhereOrInfo;
 typedef struct WhereAndInfo WhereAndInfo;
-typedef struct WhereCost WhereCost;
+typedef struct WhereLevel WhereLevel;
+typedef struct WhereLoop WhereLoop;
+typedef struct WherePath WherePath;
+typedef struct WhereTerm WhereTerm;
+typedef struct WhereLoopBuilder WhereLoopBuilder;
+typedef struct WhereScan WhereScan;
+typedef struct WhereOrCost WhereOrCost;
+typedef struct WhereOrSet WhereOrSet;
+
+/*
+** This object contains information needed to implement a single nested
+** loop in WHERE clause.
+**
+** Contrast this object with WhereLoop.  This object describes the
+** implementation of the loop.  WhereLoop describes the algorithm.
+** This object contains a pointer to the WhereLoop algorithm as one of
+** its elements.
+**
+** The WhereInfo object contains a single instance of this object for
+** each term in the FROM clause (which is to say, for each of the
+** nested loops as implemented).  The order of WhereLevel objects determines
+** the loop nested order, with WhereInfo.a[0] being the outer loop and
+** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
+*/
+struct WhereLevel {
+  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
+  int iTabCur;          /* The VDBE cursor used to access the table */
+  int iIdxCur;          /* The VDBE cursor used to access pIdx */
+  int addrBrk;          /* Jump here to break out of the loop */
+  int addrNxt;          /* Jump here to start the next IN combination */
+  int addrSkip;         /* Jump here for next iteration of skip-scan */
+  int addrCont;         /* Jump here to continue with the next loop cycle */
+  int addrFirst;        /* First instruction of interior of the loop */
+  int addrBody;         /* Beginning of the body of this loop */
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  u32 iLikeRepCntr;     /* LIKE range processing counter register (times 2) */
+  int addrLikeRep;      /* LIKE range processing address */
+#endif
+  u8 iFrom;             /* Which entry in the FROM clause */
+  u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
+  int p1, p2;           /* Operands of the opcode used to ends the loop */
+  union {               /* Information that depends on pWLoop->wsFlags */
+    struct {
+      int nIn;              /* Number of entries in aInLoop[] */
+      struct InLoop {
+        int iCur;              /* The VDBE cursor used by this IN operator */
+        int addrInTop;         /* Top of the IN loop */
+        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
+      } *aInLoop;           /* Information about each nested IN operator */
+    } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
+    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
+  } u;
+  struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
+  Bitmask notReady;          /* FROM entries not usable at this level */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  int addrVisit;        /* Address at which row is visited */
+#endif
+};
+
+/*
+** Each instance of this object represents an algorithm for evaluating one
+** term of a join.  Every term of the FROM clause will have at least
+** one corresponding WhereLoop object (unless INDEXED BY constraints
+** prevent a query solution - which is an error) and many terms of the
+** FROM clause will have multiple WhereLoop objects, each describing a
+** potential way of implementing that FROM-clause term, together with
+** dependencies and cost estimates for using the chosen algorithm.
+**
+** Query planning consists of building up a collection of these WhereLoop
+** objects, then computing a particular sequence of WhereLoop objects, with
+** one WhereLoop object per FROM clause term, that satisfy all dependencies
+** and that minimize the overall cost.
+*/
+struct WhereLoop {
+  Bitmask prereq;       /* Bitmask of other loops that must run first */
+  Bitmask maskSelf;     /* Bitmask identifying table iTab */
+#ifdef SQLITE_DEBUG
+  char cId;             /* Symbolic ID of this loop for debugging use */
+#endif
+  u8 iTab;              /* Position in FROM clause of table for this loop */
+  u8 iSortIdx;          /* Sorting index number.  0==None */
+  LogEst rSetup;        /* One-time setup cost (ex: create transient index) */
+  LogEst rRun;          /* Cost of running each loop */
+  LogEst nOut;          /* Estimated number of output rows */
+  union {
+    struct {               /* Information for internal btree tables */
+      u16 nEq;               /* Number of equality constraints */
+      Index *pIndex;         /* Index used, or NULL */
+    } btree;
+    struct {               /* Information for virtual tables */
+      int idxNum;            /* Index number */
+      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
+      i8 isOrdered;          /* True if satisfies ORDER BY */
+      u16 omitMask;          /* Terms that may be omitted */
+      char *idxStr;          /* Index identifier string */
+    } vtab;
+  } u;
+  u32 wsFlags;          /* WHERE_* flags describing the plan */
+  u16 nLTerm;           /* Number of entries in aLTerm[] */
+  u16 nSkip;            /* Number of NULL aLTerm[] entries */
+  /**** whereLoopXfer() copies fields above ***********************/
+# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
+  u16 nLSlot;           /* Number of slots allocated for aLTerm[] */
+  WhereTerm **aLTerm;   /* WhereTerms used */
+  WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
+  WhereTerm *aLTermSpace[3];  /* Initial aLTerm[] space */
+};
+
+/* This object holds the prerequisites and the cost of running a
+** subquery on one operand of an OR operator in the WHERE clause.
+** See WhereOrSet for additional information 
+*/
+struct WhereOrCost {
+  Bitmask prereq;     /* Prerequisites */
+  LogEst rRun;        /* Cost of running this subquery */
+  LogEst nOut;        /* Number of outputs for this subquery */
+};
+
+/* The WhereOrSet object holds a set of possible WhereOrCosts that
+** correspond to the subquery(s) of OR-clause processing.  Only the
+** best N_OR_COST elements are retained.
+*/
+#define N_OR_COST 3
+struct WhereOrSet {
+  u16 n;                      /* Number of valid a[] entries */
+  WhereOrCost a[N_OR_COST];   /* Set of best costs */
+};
+
+/*
+** Each instance of this object holds a sequence of WhereLoop objects
+** that implement some or all of a query plan.
+**
+** Think of each WhereLoop object as a node in a graph with arcs
+** showing dependencies and costs for travelling between nodes.  (That is
+** not a completely accurate description because WhereLoop costs are a
+** vector, not a scalar, and because dependencies are many-to-one, not
+** one-to-one as are graph nodes.  But it is a useful visualization aid.)
+** Then a WherePath object is a path through the graph that visits some
+** or all of the WhereLoop objects once.
+**
+** The "solver" works by creating the N best WherePath objects of length
+** 1.  Then using those as a basis to compute the N best WherePath objects
+** of length 2.  And so forth until the length of WherePaths equals the
+** number of nodes in the FROM clause.  The best (lowest cost) WherePath
+** at the end is the chosen query plan.
+*/
+struct WherePath {
+  Bitmask maskLoop;     /* Bitmask of all WhereLoop objects in this path */
+  Bitmask revLoop;      /* aLoop[]s that should be reversed for ORDER BY */
+  LogEst nRow;          /* Estimated number of rows generated by this path */
+  LogEst rCost;         /* Total cost of this path */
+  LogEst rUnsorted;     /* Total cost of this path ignoring sorting costs */
+  i8 isOrdered;         /* No. of ORDER BY terms satisfied. -1 for unknown */
+  WhereLoop **aLoop;    /* Array of WhereLoop objects implementing this path */
+};
 
 /*
 ** The query generator uses an array of instances of this structure to
@@ -100763,9 +123181,9 @@ typedef struct WhereCost WhereCost;
 **
 **         (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
 **
-** In this second case, wtFlag as the TERM_ORINFO set and eOperator==WO_OR
+** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
 ** and the WhereTerm.u.pOrInfo field points to auxiliary information that
-** is collected about the
+** is collected about the OR clause.
 **
 ** If a term in the WHERE clause does not match either of the two previous
 ** categories, then eOperator==0.  The WhereTerm.pExpr field is still set
@@ -100788,19 +123206,20 @@ typedef struct WhereCost WhereCost;
 ** in prereqRight and prereqAll.  The default is 64 bits, hence SQLite
 ** is only able to process joins with 64 or fewer tables.
 */
-typedef struct WhereTerm WhereTerm;
 struct WhereTerm {
   Expr *pExpr;            /* Pointer to the subexpression that is this term */
   int iParent;            /* Disable pWC->a[iParent] when this term disabled */
   int leftCursor;         /* Cursor number of X in "X <op> <expr>" */
   union {
     int leftColumn;         /* Column number of X in "X <op> <expr>" */
-    WhereOrInfo *pOrInfo;   /* Extra information if eOperator==WO_OR */
-    WhereAndInfo *pAndInfo; /* Extra information if eOperator==WO_AND */
+    WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
+    WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
   } u;
+  LogEst truthProb;       /* Probability of truth for this expression */
   u16 eOperator;          /* A WO_xx value describing <op> */
-  u8 wtFlags;             /* TERM_xxx bit flags.  See below */
+  u16 wtFlags;            /* TERM_xxx bit flags.  See below */
   u8 nChild;              /* Number of children that must disable us */
+  u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
   WhereClause *pWC;       /* The clause this term is part of */
   Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */
   Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */
@@ -100816,11 +123235,33 @@ struct WhereTerm {
 #define TERM_ORINFO     0x10   /* Need to free the WhereTerm.u.pOrInfo object */
 #define TERM_ANDINFO    0x20   /* Need to free the WhereTerm.u.pAndInfo obj */
 #define TERM_OR_OK      0x40   /* Used during OR-clause processing */
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 #  define TERM_VNULL    0x80   /* Manufactured x>NULL or x<=NULL term */
 #else
 #  define TERM_VNULL    0x00   /* Disabled if not using stat3 */
 #endif
+#define TERM_LIKEOPT    0x100  /* Virtual terms from the LIKE optimization */
+#define TERM_LIKECOND   0x200  /* Conditionally this LIKE operator term */
+#define TERM_LIKE       0x400  /* The original LIKE operator */
+#define TERM_IS         0x800  /* Term.pExpr is an IS operator */
+
+/*
+** An instance of the WhereScan object is used as an iterator for locating
+** terms in the WHERE clause that are useful to the query planner.
+*/
+struct WhereScan {
+  WhereClause *pOrigWC;      /* Original, innermost WhereClause */
+  WhereClause *pWC;          /* WhereClause currently being scanned */
+  const char *zCollName;     /* Required collating sequence, if not NULL */
+  Expr *pIdxExpr;            /* Search for this index expression */
+  char idxaff;               /* Must match this affinity, if zCollName!=NULL */
+  unsigned char nEquiv;      /* Number of entries in aEquiv[] */
+  unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
+  u32 opMask;                /* Acceptable operators */
+  int k;                     /* Resume scanning at this->pWC->a[this->k] */
+  int aiCur[11];             /* Cursors in the equivalence class */
+  i16 aiColumn[11];          /* Corresponding column number in the eq-class */
+};
 
 /*
 ** An instance of the following structure holds all information about a
@@ -100835,12 +123276,9 @@ struct WhereTerm {
 ** subclauses points to the WhereClause object for the whole clause.
 */
 struct WhereClause {
-  Parse *pParse;           /* The parser context */
-  WhereMaskSet *pMaskSet;  /* Mapping of table cursor numbers to bitmasks */
-  Bitmask vmask;           /* Bitmask identifying virtual table cursors */
+  WhereInfo *pWInfo;       /* WHERE clause processing context */
   WhereClause *pOuter;     /* Outer conjunction */
   u8 op;                   /* Split operator.  TK_AND or TK_OR */
-  u16 wctrlFlags;          /* Might include WHERE_AND_ONLY */
   int nTerm;               /* Number of terms */
   int nSlot;               /* Number of entries in a[] */
   WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
@@ -100900,348 +123338,2144 @@ struct WhereMaskSet {
 };
 
 /*
-** A WhereCost object records a lookup strategy and the estimated
-** cost of pursuing that strategy.
+** Initialize a WhereMaskSet object
 */
-struct WhereCost {
-  WherePlan plan;    /* The lookup strategy */
-  double rCost;      /* Overall cost of pursuing this search strategy */
-  Bitmask used;      /* Bitmask of cursors used by this plan */
+#define initMaskSet(P)  (P)->n=0
+
+/*
+** This object is a convenience wrapper holding all information needed
+** to construct WhereLoop objects for a particular query.
+*/
+struct WhereLoopBuilder {
+  WhereInfo *pWInfo;        /* Information about this WHERE */
+  WhereClause *pWC;         /* WHERE clause terms */
+  ExprList *pOrderBy;       /* ORDER BY clause */
+  WhereLoop *pNew;          /* Template WhereLoop */
+  WhereOrSet *pOrSet;       /* Record best loops here, if not NULL */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  UnpackedRecord *pRec;     /* Probe for stat4 (if required) */
+  int nRecValid;            /* Number of valid fields currently in pRec */
+#endif
 };
 
 /*
-** Bitmasks for the operators that indices are able to exploit.  An
-** OR-ed combination of these values can be used when searching for
-** terms in the where clause.
+** The WHERE clause processing routine has two halves.  The
+** first part does the start of the WHERE loop and the second
+** half does the tail of the WHERE loop.  An instance of
+** this structure is returned by the first half and passed
+** into the second half to give some continuity.
+**
+** An instance of this object holds the complete state of the query
+** planner.
 */
-#define WO_IN     0x001
-#define WO_EQ     0x002
+struct WhereInfo {
+  Parse *pParse;            /* Parsing and code generating context */
+  SrcList *pTabList;        /* List of tables in the join */
+  ExprList *pOrderBy;       /* The ORDER BY clause or NULL */
+  ExprList *pDistinctSet;   /* DISTINCT over all these values */
+  WhereLoop *pLoops;        /* List of all WhereLoop objects */
+  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
+  LogEst nRowOut;           /* Estimated number of output rows */
+  LogEst iLimit;            /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
+  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
+  i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
+  u8 sorted;                /* True if really sorted (not just grouped) */
+  u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */
+  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
+  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values */
+  u8 nLevel;                /* Number of nested loop */
+  u8 bOrderedInnerLoop;     /* True if only the inner-most loop is ordered */
+  int iTop;                 /* The very beginning of the WHERE loop */
+  int iContinue;            /* Jump here to continue with next record */
+  int iBreak;               /* Jump here to break out of the loop */
+  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
+  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
+  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
+  WhereClause sWC;          /* Decomposition of the WHERE clause */
+  WhereLevel a[1];          /* Information about each nest loop in WHERE */
+};
+
+/*
+** Private interfaces - callable only by other where.c routines.
+**
+** where.c:
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
+#ifdef WHERETRACE_ENABLED
+SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC);
+#endif
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+);
+
+/* wherecode.c: */
+#ifndef SQLITE_OMIT_EXPLAIN
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+);
+#else
+# define sqlite3WhereExplainOneScan(u,v,w,x,y,z) 0
+#endif /* SQLITE_OMIT_EXPLAIN */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
+);
+#else
+# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
+#endif
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
+);
+
+/* whereexpr.c: */
+SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);
+
+
+
+
+
+/*
+** Bitmasks for the operators on WhereTerm objects.  These are all
+** operators that are of interest to the query planner.  An
+** OR-ed combination of these values can be used when searching for
+** particular WhereTerms within a WhereClause.
+**
+** Value constraints:
+**     WO_EQ    == SQLITE_INDEX_CONSTRAINT_EQ
+**     WO_LT    == SQLITE_INDEX_CONSTRAINT_LT
+**     WO_LE    == SQLITE_INDEX_CONSTRAINT_LE
+**     WO_GT    == SQLITE_INDEX_CONSTRAINT_GT
+**     WO_GE    == SQLITE_INDEX_CONSTRAINT_GE
+**     WO_MATCH == SQLITE_INDEX_CONSTRAINT_MATCH
+*/
+#define WO_IN     0x0001
+#define WO_EQ     0x0002
 #define WO_LT     (WO_EQ<<(TK_LT-TK_EQ))
 #define WO_LE     (WO_EQ<<(TK_LE-TK_EQ))
 #define WO_GT     (WO_EQ<<(TK_GT-TK_EQ))
 #define WO_GE     (WO_EQ<<(TK_GE-TK_EQ))
-#define WO_MATCH  0x040
-#define WO_ISNULL 0x080
-#define WO_OR     0x100       /* Two or more OR-connected terms */
-#define WO_AND    0x200       /* Two or more AND-connected terms */
-#define WO_NOOP   0x800       /* This term does not restrict search space */
-
-#define WO_ALL    0xfff       /* Mask of all possible WO_* values */
-#define WO_SINGLE 0x0ff       /* Mask of all non-compound WO_* values */
-
-/*
-** Value for wsFlags returned by bestIndex() and stored in
-** WhereLevel.wsFlags.  These flags determine which search
-** strategies are appropriate.
-**
-** The least significant 12 bits is reserved as a mask for WO_ values above.
-** The WhereLevel.wsFlags field is usually set to WO_IN|WO_EQ|WO_ISNULL.
-** But if the table is the right table of a left join, WhereLevel.wsFlags
-** is set to WO_IN|WO_EQ.  The WhereLevel.wsFlags field can then be used as
-** the "op" parameter to findTerm when we are resolving equality constraints.
-** ISNULL constraints will then not be used on the right table of a left
-** join.  Tickets #2177 and #2189.
-*/
-#define WHERE_ROWID_EQ     0x00001000  /* rowid=EXPR or rowid IN (...) */
-#define WHERE_ROWID_RANGE  0x00002000  /* rowid<EXPR and/or rowid>EXPR */
-#define WHERE_COLUMN_EQ    0x00010000  /* x=EXPR or x IN (...) or x IS NULL */
-#define WHERE_COLUMN_RANGE 0x00020000  /* x<EXPR and/or x>EXPR */
-#define WHERE_COLUMN_IN    0x00040000  /* x IN (...) */
-#define WHERE_COLUMN_NULL  0x00080000  /* x IS NULL */
-#define WHERE_INDEXED      0x000f0000  /* Anything that uses an index */
-#define WHERE_NOT_FULLSCAN 0x100f3000  /* Does not do a full table scan */
-#define WHERE_IN_ABLE      0x000f1000  /* Able to support an IN operator */
-#define WHERE_TOP_LIMIT    0x00100000  /* x<EXPR or x<=EXPR constraint */
-#define WHERE_BTM_LIMIT    0x00200000  /* x>EXPR or x>=EXPR constraint */
-#define WHERE_BOTH_LIMIT   0x00300000  /* Both x>EXPR and x<EXPR */
-#define WHERE_IDX_ONLY     0x00800000  /* Use index only - omit table */
-#define WHERE_ORDERBY      0x01000000  /* Output will appear in correct order */
-#define WHERE_REVERSE      0x02000000  /* Scan in reverse order */
-#define WHERE_UNIQUE       0x04000000  /* Selects no more than one row */
-#define WHERE_VIRTUALTABLE 0x08000000  /* Use virtual-table processing */
-#define WHERE_MULTI_OR     0x10000000  /* OR using multiple indices */
-#define WHERE_TEMP_INDEX   0x20000000  /* Uses an ephemeral index */
-#define WHERE_DISTINCT     0x40000000  /* Correct order for DISTINCT */
+#define WO_MATCH  0x0040
+#define WO_IS     0x0080
+#define WO_ISNULL 0x0100
+#define WO_OR     0x0200       /* Two or more OR-connected terms */
+#define WO_AND    0x0400       /* Two or more AND-connected terms */
+#define WO_EQUIV  0x0800       /* Of the form A==B, both columns */
+#define WO_NOOP   0x1000       /* This term does not restrict search space */
+
+#define WO_ALL    0x1fff       /* Mask of all possible WO_* values */
+#define WO_SINGLE 0x01ff       /* Mask of all non-compound WO_* values */
+
+/*
+** These are definitions of bits in the WhereLoop.wsFlags field.
+** The particular combination of bits in each WhereLoop help to
+** determine the algorithm that WhereLoop represents.
+*/
+#define WHERE_COLUMN_EQ    0x00000001  /* x=EXPR */
+#define WHERE_COLUMN_RANGE 0x00000002  /* x<EXPR and/or x>EXPR */
+#define WHERE_COLUMN_IN    0x00000004  /* x IN (...) */
+#define WHERE_COLUMN_NULL  0x00000008  /* x IS NULL */
+#define WHERE_CONSTRAINT   0x0000000f  /* Any of the WHERE_COLUMN_xxx values */
+#define WHERE_TOP_LIMIT    0x00000010  /* x<EXPR or x<=EXPR constraint */
+#define WHERE_BTM_LIMIT    0x00000020  /* x>EXPR or x>=EXPR constraint */
+#define WHERE_BOTH_LIMIT   0x00000030  /* Both x>EXPR and x<EXPR */
+#define WHERE_IDX_ONLY     0x00000040  /* Use index only - omit table */
+#define WHERE_IPK          0x00000100  /* x is the INTEGER PRIMARY KEY */
+#define WHERE_INDEXED      0x00000200  /* WhereLoop.u.btree.pIndex is valid */
+#define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */
+#define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */
+#define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
+#define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
+#define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
+#define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */
+#define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/
+#define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */
+
+/************** End of whereInt.h ********************************************/
+/************** Continuing where we left off in wherecode.c ******************/
 
+#ifndef SQLITE_OMIT_EXPLAIN
 /*
-** Initialize a preallocated WhereClause structure.
+** This routine is a helper for explainIndexRange() below
+**
+** pStr holds the text of an expression that we are building up one term
+** at a time.  This routine adds a new term to the end of the expression.
+** Terms are separated by AND so add the "AND" text for second and subsequent
+** terms only.
 */
-static void whereClauseInit(
-  WhereClause *pWC,        /* The WhereClause to be initialized */
-  Parse *pParse,           /* The parsing context */
-  WhereMaskSet *pMaskSet,  /* Mapping from table cursor numbers to bitmasks */
-  u16 wctrlFlags           /* Might include WHERE_AND_ONLY */
+static void explainAppendTerm(
+  StrAccum *pStr,             /* The text expression being built */
+  int iTerm,                  /* Index of this term.  First is zero */
+  const char *zColumn,        /* Name of the column */
+  const char *zOp             /* Name of the operator */
 ){
-  pWC->pParse = pParse;
-  pWC->pMaskSet = pMaskSet;
-  pWC->pOuter = 0;
-  pWC->nTerm = 0;
-  pWC->nSlot = ArraySize(pWC->aStatic);
-  pWC->a = pWC->aStatic;
-  pWC->vmask = 0;
-  pWC->wctrlFlags = wctrlFlags;
+  if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+  sqlite3StrAccumAppendAll(pStr, zColumn);
+  sqlite3StrAccumAppend(pStr, zOp, 1);
+  sqlite3StrAccumAppend(pStr, "?", 1);
 }
 
-/* Forward reference */
-static void whereClauseClear(WhereClause*);
-
 /*
-** Deallocate all memory associated with a WhereOrInfo object.
+** Return the name of the i-th column of the pIdx index.
 */
-static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
-  whereClauseClear(&p->wc);
-  sqlite3DbFree(db, p);
+static const char *explainIndexColumnName(Index *pIdx, int i){
+  i = pIdx->aiColumn[i];
+  if( i==XN_EXPR ) return "<expr>";
+  if( i==XN_ROWID ) return "rowid";
+  return pIdx->pTable->aCol[i].zName;
 }
 
 /*
-** Deallocate all memory associated with a WhereAndInfo object.
+** Argument pLevel describes a strategy for scanning table pTab. This 
+** function appends text to pStr that describes the subset of table
+** rows scanned by the strategy in the form of an SQL expression.
+**
+** For example, if the query:
+**
+**   SELECT * FROM t1 WHERE a=1 AND b>2;
+**
+** is run and there is an index on (a, b), then this function returns a
+** string similar to:
+**
+**   "a=? AND b>?"
 */
-static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
-  whereClauseClear(&p->wc);
-  sqlite3DbFree(db, p);
+static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){
+  Index *pIndex = pLoop->u.btree.pIndex;
+  u16 nEq = pLoop->u.btree.nEq;
+  u16 nSkip = pLoop->nSkip;
+  int i, j;
+
+  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
+  sqlite3StrAccumAppend(pStr, " (", 2);
+  for(i=0; i<nEq; i++){
+    const char *z = explainIndexColumnName(pIndex, i);
+    if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+    sqlite3XPrintf(pStr, i>=nSkip ? "%s=?" : "ANY(%s)", z);
+  }
+
+  j = i;
+  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
+    const char *z = explainIndexColumnName(pIndex, i);
+    explainAppendTerm(pStr, i++, z, ">");
+  }
+  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
+    const char *z = explainIndexColumnName(pIndex, j);
+    explainAppendTerm(pStr, i, z, "<");
+  }
+  sqlite3StrAccumAppend(pStr, ")", 1);
 }
 
 /*
-** Deallocate a WhereClause structure.  The WhereClause structure
-** itself is not freed.  This routine is the inverse of whereClauseInit().
+** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
+** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
+** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 
+** is added to the output to describe the table scan strategy in pLevel.
+**
+** If an OP_Explain opcode is added to the VM, its address is returned.
+** Otherwise, if no OP_Explain is coded, zero is returned.
 */
-static void whereClauseClear(WhereClause *pWC){
-  int i;
-  WhereTerm *a;
-  sqlite3 *db = pWC->pParse->db;
-  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
-    if( a->wtFlags & TERM_DYNAMIC ){
-      sqlite3ExprDelete(db, a->pExpr);
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+){
+  int ret = 0;
+#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
+  if( pParse->explain==2 )
+#endif
+  {
+    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
+    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
+    sqlite3 *db = pParse->db;     /* Database handle */
+    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
+    int isSearch;                 /* True for a SEARCH. False for SCAN. */
+    WhereLoop *pLoop;             /* The controlling WhereLoop object */
+    u32 flags;                    /* Flags that describe this loop */
+    char *zMsg;                   /* Text to add to EQP output */
+    StrAccum str;                 /* EQP output string */
+    char zBuf[100];               /* Initial space for EQP output string */
+
+    pLoop = pLevel->pWLoop;
+    flags = pLoop->wsFlags;
+    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;
+
+    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+
+    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
+    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
+    if( pItem->pSelect ){
+      sqlite3XPrintf(&str, " SUBQUERY %d", pItem->iSelectId);
+    }else{
+      sqlite3XPrintf(&str, " TABLE %s", pItem->zName);
     }
-    if( a->wtFlags & TERM_ORINFO ){
-      whereOrInfoDelete(db, a->u.pOrInfo);
-    }else if( a->wtFlags & TERM_ANDINFO ){
-      whereAndInfoDelete(db, a->u.pAndInfo);
+
+    if( pItem->zAlias ){
+      sqlite3XPrintf(&str, " AS %s", pItem->zAlias);
+    }
+    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
+      const char *zFmt = 0;
+      Index *pIdx;
+
+      assert( pLoop->u.btree.pIndex!=0 );
+      pIdx = pLoop->u.btree.pIndex;
+      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
+      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
+        if( isSearch ){
+          zFmt = "PRIMARY KEY";
+        }
+      }else if( flags & WHERE_PARTIALIDX ){
+        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
+      }else if( flags & WHERE_AUTO_INDEX ){
+        zFmt = "AUTOMATIC COVERING INDEX";
+      }else if( flags & WHERE_IDX_ONLY ){
+        zFmt = "COVERING INDEX %s";
+      }else{
+        zFmt = "INDEX %s";
+      }
+      if( zFmt ){
+        sqlite3StrAccumAppend(&str, " USING ", 7);
+        sqlite3XPrintf(&str, zFmt, pIdx->zName);
+        explainIndexRange(&str, pLoop);
+      }
+    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
+      const char *zRangeOp;
+      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
+        zRangeOp = "=";
+      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
+        zRangeOp = ">? AND rowid<";
+      }else if( flags&WHERE_BTM_LIMIT ){
+        zRangeOp = ">";
+      }else{
+        assert( flags&WHERE_TOP_LIMIT);
+        zRangeOp = "<";
+      }
+      sqlite3XPrintf(&str, " USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
     }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
+      sqlite3XPrintf(&str, " VIRTUAL TABLE INDEX %d:%s",
+                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
+    }
+#endif
+#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
+    if( pLoop->nOut>=10 ){
+      sqlite3XPrintf(&str, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
+    }else{
+      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
+    }
+#endif
+    zMsg = sqlite3StrAccumFinish(&str);
+    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
   }
-  if( pWC->a!=pWC->aStatic ){
-    sqlite3DbFree(db, pWC->a);
+  return ret;
+}
+#endif /* SQLITE_OMIT_EXPLAIN */
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+/*
+** Configure the VM passed as the first argument with an
+** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 
+** implement level pLvl. Argument pSrclist is a pointer to the FROM 
+** clause that the scan reads data from.
+**
+** If argument addrExplain is not 0, it must be the address of an 
+** OP_Explain instruction that describes the same loop.
+*/
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
+){
+  const char *zObj = 0;
+  WhereLoop *pLoop = pLvl->pWLoop;
+  if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
+    zObj = pLoop->u.btree.pIndex->zName;
+  }else{
+    zObj = pSrclist->a[pLvl->iFrom].zName;
   }
+  sqlite3VdbeScanStatus(
+      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
+  );
 }
+#endif
+
 
 /*
-** Add a single new WhereTerm entry to the WhereClause object pWC.
-** The new WhereTerm object is constructed from Expr p and with wtFlags.
-** The index in pWC->a[] of the new WhereTerm is returned on success.
-** 0 is returned if the new WhereTerm could not be added due to a memory
-** allocation error.  The memory allocation failure will be recorded in
-** the db->mallocFailed flag so that higher-level functions can detect it.
+** Disable a term in the WHERE clause.  Except, do not disable the term
+** if it controls a LEFT OUTER JOIN and it did not originate in the ON
+** or USING clause of that join.
 **
-** This routine will increase the size of the pWC->a[] array as necessary.
+** Consider the term t2.z='ok' in the following queries:
 **
-** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
-** for freeing the expression p is assumed by the WhereClause object pWC.
-** This is true even if this routine fails to allocate a new WhereTerm.
+**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
+**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
+**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
 **
-** WARNING:  This routine might reallocate the space used to store
-** WhereTerms.  All pointers to WhereTerms should be invalidated after
-** calling this routine.  Such pointers may be reinitialized by referencing
-** the pWC->a[] array.
+** The t2.z='ok' is disabled in the in (2) because it originates
+** in the ON clause.  The term is disabled in (3) because it is not part
+** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
+**
+** Disabling a term causes that term to not be tested in the inner loop
+** of the join.  Disabling is an optimization.  When terms are satisfied
+** by indices, we disable them to prevent redundant tests in the inner
+** loop.  We would get the correct results if nothing were ever disabled,
+** but joins might run a little slower.  The trick is to disable as much
+** as we can without disabling too much.  If we disabled in (1), we'd get
+** the wrong answer.  See ticket #813.
+**
+** If all the children of a term are disabled, then that term is also
+** automatically disabled.  In this way, terms get disabled if derived
+** virtual terms are tested first.  For example:
+**
+**      x GLOB 'abc*' AND x>='abc' AND x<'acd'
+**      \___________/     \______/     \_____/
+**         parent          child1       child2
+**
+** Only the parent term was in the original WHERE clause.  The child1
+** and child2 terms were added by the LIKE optimization.  If both of
+** the virtual child terms are valid, then testing of the parent can be 
+** skipped.
+**
+** Usually the parent term is marked as TERM_CODED.  But if the parent
+** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
+** The TERM_LIKECOND marking indicates that the term should be coded inside
+** a conditional such that is only evaluated on the second pass of a
+** LIKE-optimization loop, when scanning BLOBs instead of strings.
 */
-static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
-  WhereTerm *pTerm;
-  int idx;
-  testcase( wtFlags & TERM_VIRTUAL );  /* EV: R-00211-15100 */
-  if( pWC->nTerm>=pWC->nSlot ){
-    WhereTerm *pOld = pWC->a;
-    sqlite3 *db = pWC->pParse->db;
-    pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
-    if( pWC->a==0 ){
-      if( wtFlags & TERM_DYNAMIC ){
-        sqlite3ExprDelete(db, p);
-      }
-      pWC->a = pOld;
-      return 0;
-    }
-    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
-    if( pOld!=pWC->aStatic ){
-      sqlite3DbFree(db, pOld);
+static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
+  int nLoop = 0;
+  while( pTerm
+      && (pTerm->wtFlags & TERM_CODED)==0
+      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+      && (pLevel->notReady & pTerm->prereqAll)==0
+  ){
+    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
+      pTerm->wtFlags |= TERM_LIKECOND;
+    }else{
+      pTerm->wtFlags |= TERM_CODED;
     }
-    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
+    if( pTerm->iParent<0 ) break;
+    pTerm = &pTerm->pWC->a[pTerm->iParent];
+    pTerm->nChild--;
+    if( pTerm->nChild!=0 ) break;
+    nLoop++;
   }
-  pTerm = &pWC->a[idx = pWC->nTerm++];
-  pTerm->pExpr = p;
-  pTerm->wtFlags = wtFlags;
-  pTerm->pWC = pWC;
-  pTerm->iParent = -1;
-  return idx;
 }
 
 /*
-** This routine identifies subexpressions in the WHERE clause where
-** each subexpression is separated by the AND operator or some other
-** operator specified in the op parameter.  The WhereClause structure
-** is filled with pointers to subexpressions.  For example:
+** Code an OP_Affinity opcode to apply the column affinity string zAff
+** to the n registers starting at base. 
 **
-**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
-**           \________/     \_______________/     \________________/
-**            slot[0]            slot[1]               slot[2]
+** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the
+** beginning and end of zAff are ignored.  If all entries in zAff are
+** SQLITE_AFF_BLOB, then no code gets generated.
 **
-** The original WHERE clause in pExpr is unaltered.  All this routine
-** does is make slot[] entries point to substructure within pExpr.
+** This routine makes its own copy of zAff so that the caller is free
+** to modify zAff after this routine returns.
+*/
+static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
+  Vdbe *v = pParse->pVdbe;
+  if( zAff==0 ){
+    assert( pParse->db->mallocFailed );
+    return;
+  }
+  assert( v!=0 );
+
+  /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning
+  ** and end of the affinity string.
+  */
+  while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){
+    n--;
+    base++;
+    zAff++;
+  }
+  while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
+    n--;
+  }
+
+  /* Code the OP_Affinity opcode if there is anything left to do. */
+  if( n>0 ){
+    sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);
+    sqlite3ExprCacheAffinityChange(pParse, base, n);
+  }
+}
+
+
+/*
+** Generate code for a single equality term of the WHERE clause.  An equality
+** term can be either X=expr or X IN (...).   pTerm is the term to be 
+** coded.
 **
-** In the previous sentence and in the diagram, "slot[]" refers to
-** the WhereClause.a[] array.  The slot[] array grows as needed to contain
-** all terms of the WHERE clause.
+** The current value for the constraint is left in register iReg.
+**
+** For a constraint of the form X=expr, the expression is evaluated and its
+** result is left on the stack.  For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
 */
-static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
-  pWC->op = (u8)op;
-  if( pExpr==0 ) return;
-  if( pExpr->op!=op ){
-    whereClauseInsert(pWC, pExpr, 0);
+static int codeEqualityTerm(
+  Parse *pParse,      /* The parsing context */
+  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
+  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
+  int iEq,            /* Index of the equality term within this level */
+  int bRev,           /* True for reverse-order IN operations */
+  int iTarget         /* Attempt to leave results in this register */
+){
+  Expr *pX = pTerm->pExpr;
+  Vdbe *v = pParse->pVdbe;
+  int iReg;                  /* Register holding results */
+
+  assert( iTarget>0 );
+  if( pX->op==TK_EQ || pX->op==TK_IS ){
+    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+  }else if( pX->op==TK_ISNULL ){
+    iReg = iTarget;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
   }else{
-    whereSplit(pWC, pExpr->pLeft, op);
-    whereSplit(pWC, pExpr->pRight, op);
+    int eType;
+    int iTab;
+    struct InLoop *pIn;
+    WhereLoop *pLoop = pLevel->pWLoop;
+
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+      && pLoop->u.btree.pIndex!=0
+      && pLoop->u.btree.pIndex->aSortOrder[iEq]
+    ){
+      testcase( iEq==0 );
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    assert( pX->op==TK_IN );
+    iReg = iTarget;
+    eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0);
+    if( eType==IN_INDEX_INDEX_DESC ){
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    iTab = pX->iTable;
+    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
+    VdbeCoverageIf(v, bRev);
+    VdbeCoverageIf(v, !bRev);
+    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+    pLoop->wsFlags |= WHERE_IN_ABLE;
+    if( pLevel->u.in.nIn==0 ){
+      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+    }
+    pLevel->u.in.nIn++;
+    pLevel->u.in.aInLoop =
+       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
+                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
+    pIn = pLevel->u.in.aInLoop;
+    if( pIn ){
+      pIn += pLevel->u.in.nIn - 1;
+      pIn->iCur = iTab;
+      if( eType==IN_INDEX_ROWID ){
+        pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+      }else{
+        pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+      }
+      pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
+      sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v);
+    }else{
+      pLevel->u.in.nIn = 0;
+    }
+#endif
+  }
+  disableTerm(pLevel, pTerm);
+  return iReg;
+}
+
+/*
+** Generate code that will evaluate all == and IN constraints for an
+** index scan.
+**
+** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
+** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
+** The index has as many as three equality constraints, but in this
+** example, the third "c" value is an inequality.  So only two 
+** constraints are coded.  This routine will generate code to evaluate
+** a==5 and b IN (1,2,3).  The current values for a and b will be stored
+** in consecutive registers and the index of the first register is returned.
+**
+** In the example above nEq==2.  But this subroutine works for any value
+** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
+** The only thing it does is allocate the pLevel->iMem memory cell and
+** compute the affinity string.
+**
+** The nExtraReg parameter is 0 or 1.  It is 0 if all WHERE clause constraints
+** are == or IN and are covered by the nEq.  nExtraReg is 1 if there is
+** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
+** occurs after the nEq quality constraints.
+**
+** This routine allocates a range of nEq+nExtraReg memory cells and returns
+** the index of the first memory cell in that range. The code that
+** calls this routine will use that memory range to store keys for
+** start and termination conditions of the loop.
+** key value of the loop.  If one or more IN operators appear, then
+** this routine allocates an additional nEq memory cells for internal
+** use.
+**
+** Before returning, *pzAff is set to point to a buffer containing a
+** copy of the column affinity string of the index allocated using
+** sqlite3DbMalloc(). Except, entries in the copy of the string associated
+** with equality constraints that use BLOB or NONE affinity are set to
+** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
+**
+**   CREATE TABLE t1(a TEXT PRIMARY KEY, b);
+**   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
+**
+** In the example above, the index on t1(a) has TEXT affinity. But since
+** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
+** no conversion should be attempted before using a t2.b value as part of
+** a key to search the index. Hence the first byte in the returned affinity
+** string in this example would be set to SQLITE_AFF_BLOB.
+*/
+static int codeAllEqualityTerms(
+  Parse *pParse,        /* Parsing context */
+  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
+  int bRev,             /* Reverse the order of IN operators */
+  int nExtraReg,        /* Number of extra registers to allocate */
+  char **pzAff          /* OUT: Set to point to affinity string */
+){
+  u16 nEq;                      /* The number of == or IN constraints to code */
+  u16 nSkip;                    /* Number of left-most columns to skip */
+  Vdbe *v = pParse->pVdbe;      /* The vm under construction */
+  Index *pIdx;                  /* The index being used for this loop */
+  WhereTerm *pTerm;             /* A single constraint term */
+  WhereLoop *pLoop;             /* The WhereLoop object */
+  int j;                        /* Loop counter */
+  int regBase;                  /* Base register */
+  int nReg;                     /* Number of registers to allocate */
+  char *zAff;                   /* Affinity string to return */
+
+  /* This module is only called on query plans that use an index. */
+  pLoop = pLevel->pWLoop;
+  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  nEq = pLoop->u.btree.nEq;
+  nSkip = pLoop->nSkip;
+  pIdx = pLoop->u.btree.pIndex;
+  assert( pIdx!=0 );
+
+  /* Figure out how many memory cells we will need then allocate them.
+  */
+  regBase = pParse->nMem + 1;
+  nReg = pLoop->u.btree.nEq + nExtraReg;
+  pParse->nMem += nReg;
+
+  zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
+  assert( zAff!=0 || pParse->db->mallocFailed );
+
+  if( nSkip ){
+    int iIdxCur = pLevel->iIdxCur;
+    sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
+    j = sqlite3VdbeAddOp0(v, OP_Goto);
+    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
+                            iIdxCur, 0, regBase, nSkip);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    sqlite3VdbeJumpHere(v, j);
+    for(j=0; j<nSkip; j++){
+      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
+      testcase( pIdx->aiColumn[j]==XN_EXPR );
+      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
+    }
+  }    
+
+  /* Evaluate the equality constraints
+  */
+  assert( zAff==0 || (int)strlen(zAff)>=nEq );
+  for(j=nSkip; j<nEq; j++){
+    int r1;
+    pTerm = pLoop->aLTerm[j];
+    assert( pTerm!=0 );
+    /* The following testcase is true for indices with redundant columns. 
+    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
+    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
+    if( r1!=regBase+j ){
+      if( nReg==1 ){
+        sqlite3ReleaseTempReg(pParse, regBase);
+        regBase = r1;
+      }else{
+        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+      }
+    }
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IN );
+    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
+      Expr *pRight = pTerm->pExpr->pRight;
+      if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
+        VdbeCoverage(v);
+      }
+      if( zAff ){
+        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+        if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+      }
+    }
   }
+  *pzAff = zAff;
+  return regBase;
 }
 
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
 /*
-** Initialize an expression mask set (a WhereMaskSet object)
+** If the most recently coded instruction is a constant range constraint
+** (a string literal) that originated from the LIKE optimization, then 
+** set P3 and P5 on the OP_String opcode so that the string will be cast
+** to a BLOB at appropriate times.
+**
+** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
+** expression: "x>='ABC' AND x<'abd'".  But this requires that the range
+** scan loop run twice, once for strings and a second time for BLOBs.
+** The OP_String opcodes on the second pass convert the upper and lower
+** bound string constants to blobs.  This routine makes the necessary changes
+** to the OP_String opcodes for that to happen.
+**
+** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
+** only the one pass through the string space is required, so this routine
+** becomes a no-op.
 */
-#define initMaskSet(P)  memset(P, 0, sizeof(*P))
+static void whereLikeOptimizationStringFixup(
+  Vdbe *v,                /* prepared statement under construction */
+  WhereLevel *pLevel,     /* The loop that contains the LIKE operator */
+  WhereTerm *pTerm        /* The upper or lower bound just coded */
+){
+  if( pTerm->wtFlags & TERM_LIKEOPT ){
+    VdbeOp *pOp;
+    assert( pLevel->iLikeRepCntr>0 );
+    pOp = sqlite3VdbeGetOp(v, -1);
+    assert( pOp!=0 );
+    assert( pOp->opcode==OP_String8 
+            || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
+    pOp->p3 = (int)(pLevel->iLikeRepCntr>>1);  /* Register holding counter */
+    pOp->p5 = (u8)(pLevel->iLikeRepCntr&1);    /* ASC or DESC */
+  }
+}
+#else
+# define whereLikeOptimizationStringFixup(A,B,C)
+#endif
 
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
 /*
-** Return the bitmask for the given cursor number.  Return 0 if
-** iCursor is not in the set.
+** Information is passed from codeCursorHint() down to individual nodes of
+** the expression tree (by sqlite3WalkExpr()) using an instance of this
+** structure.
 */
-static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
-  int i;
-  assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
-  for(i=0; i<pMaskSet->n; i++){
-    if( pMaskSet->ix[i]==iCursor ){
-      return ((Bitmask)1)<<i;
-    }
+struct CCurHint {
+  int iTabCur;    /* Cursor for the main table */
+  int iIdxCur;    /* Cursor for the index, if pIdx!=0.  Unused otherwise */
+  Index *pIdx;    /* The index used to access the table */
+};
+
+/*
+** This function is called for every node of an expression that is a candidate
+** for a cursor hint on an index cursor.  For TK_COLUMN nodes that reference
+** the table CCurHint.iTabCur, verify that the same column can be
+** accessed through the index.  If it cannot, then set pWalker->eCode to 1.
+*/
+static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  assert( pHint->pIdx!=0 );
+  if( pExpr->op==TK_COLUMN
+   && pExpr->iTable==pHint->iTabCur
+   && sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn)<0
+  ){
+    pWalker->eCode = 1;
   }
-  return 0;
+  return WRC_Continue;
 }
 
 /*
-** Create a new mask for cursor iCursor.
+** Test whether or not expression pExpr, which was part of a WHERE clause,
+** should be included in the cursor-hint for a table that is on the rhs
+** of a LEFT JOIN. Set Walker.eCode to non-zero before returning if the 
+** expression is not suitable.
 **
-** There is one cursor per table in the FROM clause.  The number of
-** tables in the FROM clause is limited by a test early in the
-** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
-** array will never overflow.
+** An expression is unsuitable if it might evaluate to non NULL even if
+** a TK_COLUMN node that does affect the value of the expression is set
+** to NULL. For example:
+**
+**   col IS NULL
+**   col IS NOT NULL
+**   coalesce(col, 1)
+**   CASE WHEN col THEN 0 ELSE 1 END
 */
-static void createMask(WhereMaskSet *pMaskSet, int iCursor){
-  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
-  pMaskSet->ix[pMaskSet->n++] = iCursor;
+static int codeCursorHintIsOrFunction(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_IS 
+   || pExpr->op==TK_ISNULL || pExpr->op==TK_ISNOT 
+   || pExpr->op==TK_NOTNULL || pExpr->op==TK_CASE 
+  ){
+    pWalker->eCode = 1;
+  }else if( pExpr->op==TK_FUNCTION ){
+    int d1;
+    char d2[3];
+    if( 0==sqlite3IsLikeFunction(pWalker->pParse->db, pExpr, &d1, d2) ){
+      pWalker->eCode = 1;
+    }
+  }
+
+  return WRC_Continue;
 }
 
+
 /*
-** This routine walks (recursively) an expression tree and generates
-** a bitmask indicating which tables are used in that expression
-** tree.
+** This function is called on every node of an expression tree used as an
+** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN
+** that accesses any table other than the one identified by
+** CCurHint.iTabCur, then do the following:
 **
-** In order for this routine to work, the calling function must have
-** previously invoked sqlite3ResolveExprNames() on the expression.  See
-** the header comment on that routine for additional information.
-** The sqlite3ResolveExprNames() routines looks for column names and
-** sets their opcodes to TK_COLUMN and their Expr.iTable fields to
-** the VDBE cursor number of the table.  This routine just has to
-** translate the cursor numbers into bitmask values and OR all
-** the bitmasks together.
-*/
-static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
-static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
-static Bitmask exprTableUsage(WhereMaskSet *pMaskSet, Expr *p){
-  Bitmask mask = 0;
-  if( p==0 ) return 0;
-  if( p->op==TK_COLUMN ){
-    mask = getMask(pMaskSet, p->iTable);
-    return mask;
+**   1) allocate a register and code an OP_Column instruction to read 
+**      the specified column into the new register, and
+**
+**   2) transform the expression node to a TK_REGISTER node that reads 
+**      from the newly populated register.
+**
+** Also, if the node is a TK_COLUMN that does access the table idenified
+** by pCCurHint.iTabCur, and an index is being used (which we will
+** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
+** an access of the index rather than the original table.
+*/
+static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
+  int rc = WRC_Continue;
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  if( pExpr->op==TK_COLUMN ){
+    if( pExpr->iTable!=pHint->iTabCur ){
+      Vdbe *v = pWalker->pParse->pVdbe;
+      int reg = ++pWalker->pParse->nMem;   /* Register for column value */
+      sqlite3ExprCodeGetColumnOfTable(
+          v, pExpr->pTab, pExpr->iTable, pExpr->iColumn, reg
+      );
+      pExpr->op = TK_REGISTER;
+      pExpr->iTable = reg;
+    }else if( pHint->pIdx!=0 ){
+      pExpr->iTable = pHint->iIdxCur;
+      pExpr->iColumn = sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn);
+      assert( pExpr->iColumn>=0 );
+    }
+  }else if( pExpr->op==TK_AGG_FUNCTION ){
+    /* An aggregate function in the WHERE clause of a query means this must
+    ** be a correlated sub-query, and expression pExpr is an aggregate from
+    ** the parent context. Do not walk the function arguments in this case.
+    **
+    ** todo: It should be possible to replace this node with a TK_REGISTER
+    ** expression, as the result of the expression must be stored in a 
+    ** register at this point. The same holds for TK_AGG_COLUMN nodes. */
+    rc = WRC_Prune;
   }
-  mask = exprTableUsage(pMaskSet, p->pRight);
-  mask |= exprTableUsage(pMaskSet, p->pLeft);
-  if( ExprHasProperty(p, EP_xIsSelect) ){
-    mask |= exprSelectTableUsage(pMaskSet, p->x.pSelect);
-  }else{
-    mask |= exprListTableUsage(pMaskSet, p->x.pList);
+  return rc;
+}
+
+/*
+** Insert an OP_CursorHint instruction if it is appropriate to do so.
+*/
+static void codeCursorHint(
+  struct SrcList_item *pTabItem,  /* FROM clause item */
+  WhereInfo *pWInfo,    /* The where clause */
+  WhereLevel *pLevel,   /* Which loop to provide hints for */
+  WhereTerm *pEndRange  /* Hint this end-of-scan boundary term if not NULL */
+){
+  Parse *pParse = pWInfo->pParse;
+  sqlite3 *db = pParse->db;
+  Vdbe *v = pParse->pVdbe;
+  Expr *pExpr = 0;
+  WhereLoop *pLoop = pLevel->pWLoop;
+  int iCur;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  int i, j;
+  struct CCurHint sHint;
+  Walker sWalker;
+
+  if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;
+  iCur = pLevel->iTabCur;
+  assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );
+  sHint.iTabCur = iCur;
+  sHint.iIdxCur = pLevel->iIdxCur;
+  sHint.pIdx = pLoop->u.btree.pIndex;
+  memset(&sWalker, 0, sizeof(sWalker));
+  sWalker.pParse = pParse;
+  sWalker.u.pCCurHint = &sHint;
+  pWC = &pWInfo->sWC;
+  for(i=0; i<pWC->nTerm; i++){
+    pTerm = &pWC->a[i];
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( pTerm->prereqAll & pLevel->notReady ) continue;
+
+    /* Any terms specified as part of the ON(...) clause for any LEFT 
+    ** JOIN for which the current table is not the rhs are omitted
+    ** from the cursor-hint. 
+    **
+    ** If this table is the rhs of a LEFT JOIN, "IS" or "IS NULL" terms 
+    ** that were specified as part of the WHERE clause must be excluded.
+    ** This is to address the following:
+    **
+    **   SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;
+    **
+    ** Say there is a single row in t2 that matches (t1.a=t2.b), but its
+    ** t2.c values is not NULL. If the (t2.c IS NULL) constraint is 
+    ** pushed down to the cursor, this row is filtered out, causing
+    ** SQLite to synthesize a row of NULL values. Which does match the
+    ** WHERE clause, and so the query returns a row. Which is incorrect.
+    **
+    ** For the same reason, WHERE terms such as:
+    **
+    **   WHERE 1 = (t2.c IS NULL)
+    **
+    ** are also excluded. See codeCursorHintIsOrFunction() for details.
+    */
+    if( pTabItem->fg.jointype & JT_LEFT ){
+      Expr *pExpr = pTerm->pExpr;
+      if( !ExprHasProperty(pExpr, EP_FromJoin) 
+       || pExpr->iRightJoinTable!=pTabItem->iCursor
+      ){
+        sWalker.eCode = 0;
+        sWalker.xExprCallback = codeCursorHintIsOrFunction;
+        sqlite3WalkExpr(&sWalker, pTerm->pExpr);
+        if( sWalker.eCode ) continue;
+      }
+    }else{
+      if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
+    }
+
+    /* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
+    ** the cursor.  These terms are not needed as hints for a pure range
+    ** scan (that has no == terms) so omit them. */
+    if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){
+      for(j=0; j<pLoop->nLTerm && pLoop->aLTerm[j]!=pTerm; j++){}
+      if( j<pLoop->nLTerm ) continue;
+    }
+
+    /* No subqueries or non-deterministic functions allowed */
+    if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;
+
+    /* For an index scan, make sure referenced columns are actually in
+    ** the index. */
+    if( sHint.pIdx!=0 ){
+      sWalker.eCode = 0;
+      sWalker.xExprCallback = codeCursorHintCheckExpr;
+      sqlite3WalkExpr(&sWalker, pTerm->pExpr);
+      if( sWalker.eCode ) continue;
+    }
+
+    /* If we survive all prior tests, that means this term is worth hinting */
+    pExpr = sqlite3ExprAnd(db, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
+  }
+  if( pExpr!=0 ){
+    sWalker.xExprCallback = codeCursorHintFixExpr;
+    sqlite3WalkExpr(&sWalker, pExpr);
+    sqlite3VdbeAddOp4(v, OP_CursorHint, 
+                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
+                      (const char*)pExpr, P4_EXPR);
   }
-  return mask;
 }
-static Bitmask exprListTableUsage(WhereMaskSet *pMaskSet, ExprList *pList){
-  int i;
-  Bitmask mask = 0;
-  if( pList ){
-    for(i=0; i<pList->nExpr; i++){
-      mask |= exprTableUsage(pMaskSet, pList->a[i].pExpr);
+#else
+# define codeCursorHint(A,B,C,D)  /* No-op */
+#endif /* SQLITE_ENABLE_CURSOR_HINTS */
+
+/*
+** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains
+** a rowid value just read from cursor iIdxCur, open on index pIdx. This
+** function generates code to do a deferred seek of cursor iCur to the 
+** rowid stored in register iRowid.
+**
+** Normally, this is just:
+**
+**   OP_Seek $iCur $iRowid
+**
+** However, if the scan currently being coded is a branch of an OR-loop and
+** the statement currently being coded is a SELECT, then P3 of the OP_Seek
+** is set to iIdxCur and P4 is set to point to an array of integers
+** containing one entry for each column of the table cursor iCur is open 
+** on. For each table column, if the column is the i'th column of the 
+** index, then the corresponding array entry is set to (i+1). If the column
+** does not appear in the index at all, the array entry is set to 0.
+*/
+static void codeDeferredSeek(
+  WhereInfo *pWInfo,              /* Where clause context */
+  Index *pIdx,                    /* Index scan is using */
+  int iCur,                       /* Cursor for IPK b-tree */
+  int iIdxCur                     /* Index cursor */
+){
+  Parse *pParse = pWInfo->pParse; /* Parse context */
+  Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */
+
+  assert( iIdxCur>0 );
+  assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
+  
+  sqlite3VdbeAddOp3(v, OP_Seek, iIdxCur, 0, iCur);
+  if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
+   && DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
+  ){
+    int i;
+    Table *pTab = pIdx->pTable;
+    int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
+    if( ai ){
+      ai[0] = pTab->nCol;
+      for(i=0; i<pIdx->nColumn-1; i++){
+        assert( pIdx->aiColumn[i]<pTab->nCol );
+        if( pIdx->aiColumn[i]>=0 ) ai[pIdx->aiColumn[i]+1] = i+1;
+      }
+      sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
     }
   }
-  return mask;
 }
-static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
-  Bitmask mask = 0;
-  while( pS ){
-    SrcList *pSrc = pS->pSrc;
-    mask |= exprListTableUsage(pMaskSet, pS->pEList);
-    mask |= exprListTableUsage(pMaskSet, pS->pGroupBy);
-    mask |= exprListTableUsage(pMaskSet, pS->pOrderBy);
-    mask |= exprTableUsage(pMaskSet, pS->pWhere);
-    mask |= exprTableUsage(pMaskSet, pS->pHaving);
-    if( ALWAYS(pSrc!=0) ){
-      int i;
-      for(i=0; i<pSrc->nSrc; i++){
-        mask |= exprSelectTableUsage(pMaskSet, pSrc->a[i].pSelect);
-        mask |= exprTableUsage(pMaskSet, pSrc->a[i].pOn);
+
+/*
+** Generate code for the start of the iLevel-th loop in the WHERE clause
+** implementation described by pWInfo.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
+){
+  int j, k;            /* Loop counters */
+  int iCur;            /* The VDBE cursor for the table */
+  int addrNxt;         /* Where to jump to continue with the next IN case */
+  int omitTable;       /* True if we use the index only */
+  int bRev;            /* True if we need to scan in reverse order */
+  WhereLevel *pLevel;  /* The where level to be coded */
+  WhereLoop *pLoop;    /* The WhereLoop object being coded */
+  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
+  WhereTerm *pTerm;               /* A WHERE clause term */
+  Parse *pParse;                  /* Parsing context */
+  sqlite3 *db;                    /* Database connection */
+  Vdbe *v;                        /* The prepared stmt under constructions */
+  struct SrcList_item *pTabItem;  /* FROM clause term being coded */
+  int addrBrk;                    /* Jump here to break out of the loop */
+  int addrCont;                   /* Jump here to continue with next cycle */
+  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
+  int iReleaseReg = 0;      /* Temp register to free before returning */
+
+  pParse = pWInfo->pParse;
+  v = pParse->pVdbe;
+  pWC = &pWInfo->sWC;
+  db = pParse->db;
+  pLevel = &pWInfo->a[iLevel];
+  pLoop = pLevel->pWLoop;
+  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
+  iCur = pTabItem->iCursor;
+  pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+  bRev = (pWInfo->revMask>>iLevel)&1;
+  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
+           && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;
+  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
+
+  /* Create labels for the "break" and "continue" instructions
+  ** for the current loop.  Jump to addrBrk to break out of a loop.
+  ** Jump to cont to go immediately to the next iteration of the
+  ** loop.
+  **
+  ** When there is an IN operator, we also have a "addrNxt" label that
+  ** means to continue with the next IN value combination.  When
+  ** there are no IN operators in the constraints, the "addrNxt" label
+  ** is the same as "addrBrk".
+  */
+  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+
+  /* If this is the right table of a LEFT OUTER JOIN, allocate and
+  ** initialize a memory cell that records if this table matches any
+  ** row of the left table of the join.
+  */
+  if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
+    pLevel->iLeftJoin = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+    VdbeComment((v, "init LEFT JOIN no-match flag"));
+  }
+
+  /* Special case of a FROM clause subquery implemented as a co-routine */
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+    pLevel->op = OP_Goto;
+  }else
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
+    **          to access the data.
+    */
+    int iReg;   /* P3 Value for OP_VFilter */
+    int addrNotFound;
+    int nConstraint = pLoop->nLTerm;
+    int iIn;    /* Counter for IN constraints */
+
+    sqlite3ExprCachePush(pParse);
+    iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+    addrNotFound = pLevel->addrBrk;
+    for(j=0; j<nConstraint; j++){
+      int iTarget = iReg+j+2;
+      pTerm = pLoop->aLTerm[j];
+      if( NEVER(pTerm==0) ) continue;
+      if( pTerm->eOperator & WO_IN ){
+        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+        addrNotFound = pLevel->addrNxt;
+      }else{
+        sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
       }
     }
-    pS = pS->pPrior;
+    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+                      pLoop->u.vtab.idxStr,
+                      pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
+    VdbeCoverage(v);
+    pLoop->u.vtab.needFree = 0;
+    pLevel->p1 = iCur;
+    pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+    iIn = pLevel->u.in.nIn;
+    for(j=nConstraint-1; j>=0; j--){
+      pTerm = pLoop->aLTerm[j];
+      if( j<16 && (pLoop->u.vtab.omitMask>>j)&1 ){
+        disableTerm(pLevel, pTerm);
+      }else if( (pTerm->eOperator & WO_IN)!=0 ){
+        Expr *pCompare;  /* The comparison operator */
+        Expr *pRight;    /* RHS of the comparison */
+        VdbeOp *pOp;     /* Opcode to access the value of the IN constraint */
+
+        /* Reload the constraint value into reg[iReg+j+2].  The same value
+        ** was loaded into the same register prior to the OP_VFilter, but
+        ** the xFilter implementation might have changed the datatype or
+        ** encoding of the value in the register, so it *must* be reloaded. */
+        assert( pLevel->u.in.aInLoop!=0 || db->mallocFailed );
+        if( !db->mallocFailed ){
+          assert( iIn>0 );
+          pOp = sqlite3VdbeGetOp(v, pLevel->u.in.aInLoop[--iIn].addrInTop);
+          assert( pOp->opcode==OP_Column || pOp->opcode==OP_Rowid );
+          assert( pOp->opcode!=OP_Column || pOp->p3==iReg+j+2 );
+          assert( pOp->opcode!=OP_Rowid || pOp->p2==iReg+j+2 );
+          testcase( pOp->opcode==OP_Rowid );
+          sqlite3VdbeAddOp3(v, pOp->opcode, pOp->p1, pOp->p2, pOp->p3);
+        }
+
+        /* Generate code that will continue to the next row if 
+        ** the IN constraint is not satisfied */
+        pCompare = sqlite3PExpr(pParse, TK_EQ, 0, 0, 0);
+        assert( pCompare!=0 || db->mallocFailed );
+        if( pCompare ){
+          pCompare->pLeft = pTerm->pExpr->pLeft;
+          pCompare->pRight = pRight = sqlite3Expr(db, TK_REGISTER, 0);
+          if( pRight ){
+            pRight->iTable = iReg+j+2;
+            sqlite3ExprIfFalse(pParse, pCompare, pLevel->addrCont, 0);
+          }
+          pCompare->pLeft = 0;
+          sqlite3ExprDelete(db, pCompare);
+        }
+      }
+    }
+    /* These registers need to be preserved in case there is an IN operator
+    ** loop.  So we could deallocate the registers here (and potentially
+    ** reuse them later) if (pLoop->wsFlags & WHERE_IN_ABLE)==0.  But it seems
+    ** simpler and safer to simply not reuse the registers.
+    **
+    **    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+    */
+    sqlite3ExprCachePop(pParse);
+  }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+  if( (pLoop->wsFlags & WHERE_IPK)!=0
+   && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+  ){
+    /* Case 2:  We can directly reference a single row using an
+    **          equality comparison against the ROWID field.  Or
+    **          we reference multiple rows using a "rowid IN (...)"
+    **          construct.
+    */
+    assert( pLoop->u.btree.nEq==1 );
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->pExpr!=0 );
+    assert( omitTable==0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    iReleaseReg = ++pParse->nMem;
+    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
+    if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
+    addrNxt = pLevel->addrNxt;
+    sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);
+    VdbeCoverage(v);
+    sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
+    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+    VdbeComment((v, "pk"));
+    pLevel->op = OP_Noop;
+  }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+         && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+  ){
+    /* Case 3:  We have an inequality comparison against the ROWID field.
+    */
+    int testOp = OP_Noop;
+    int start;
+    int memEndValue = 0;
+    WhereTerm *pStart, *pEnd;
+
+    assert( omitTable==0 );
+    j = 0;
+    pStart = pEnd = 0;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+    assert( pStart!=0 || pEnd!=0 );
+    if( bRev ){
+      pTerm = pStart;
+      pStart = pEnd;
+      pEnd = pTerm;
+    }
+    codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
+    if( pStart ){
+      Expr *pX;             /* The expression that defines the start bound */
+      int r1, rTemp;        /* Registers for holding the start boundary */
+
+      /* The following constant maps TK_xx codes into corresponding 
+      ** seek opcodes.  It depends on a particular ordering of TK_xx
+      */
+      const u8 aMoveOp[] = {
+           /* TK_GT */  OP_SeekGT,
+           /* TK_LE */  OP_SeekLE,
+           /* TK_LT */  OP_SeekLT,
+           /* TK_GE */  OP_SeekGE
+      };
+      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
+      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
+      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
+
+      assert( (pStart->wtFlags & TERM_VNULL)==0 );
+      testcase( pStart->wtFlags & TERM_VIRTUAL );
+      pX = pStart->pExpr;
+      assert( pX!=0 );
+      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
+      r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
+      sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
+      VdbeComment((v, "pk"));
+      VdbeCoverageIf(v, pX->op==TK_GT);
+      VdbeCoverageIf(v, pX->op==TK_LE);
+      VdbeCoverageIf(v, pX->op==TK_LT);
+      VdbeCoverageIf(v, pX->op==TK_GE);
+      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
+      sqlite3ReleaseTempReg(pParse, rTemp);
+      disableTerm(pLevel, pStart);
+    }else{
+      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+    }
+    if( pEnd ){
+      Expr *pX;
+      pX = pEnd->pExpr;
+      assert( pX!=0 );
+      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
+      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
+      testcase( pEnd->wtFlags & TERM_VIRTUAL );
+      memEndValue = ++pParse->nMem;
+      sqlite3ExprCode(pParse, pX->pRight, memEndValue);
+      if( pX->op==TK_LT || pX->op==TK_GT ){
+        testOp = bRev ? OP_Le : OP_Ge;
+      }else{
+        testOp = bRev ? OP_Lt : OP_Gt;
+      }
+      disableTerm(pLevel, pEnd);
+    }
+    start = sqlite3VdbeCurrentAddr(v);
+    pLevel->op = bRev ? OP_Prev : OP_Next;
+    pLevel->p1 = iCur;
+    pLevel->p2 = start;
+    assert( pLevel->p5==0 );
+    if( testOp!=OP_Noop ){
+      iRowidReg = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
+      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
+      VdbeCoverageIf(v, testOp==OP_Le);
+      VdbeCoverageIf(v, testOp==OP_Lt);
+      VdbeCoverageIf(v, testOp==OP_Ge);
+      VdbeCoverageIf(v, testOp==OP_Gt);
+      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+    }
+  }else if( pLoop->wsFlags & WHERE_INDEXED ){
+    /* Case 4: A scan using an index.
+    **
+    **         The WHERE clause may contain zero or more equality 
+    **         terms ("==" or "IN" operators) that refer to the N
+    **         left-most columns of the index. It may also contain
+    **         inequality constraints (>, <, >= or <=) on the indexed
+    **         column that immediately follows the N equalities. Only 
+    **         the right-most column can be an inequality - the rest must
+    **         use the "==" and "IN" operators. For example, if the 
+    **         index is on (x,y,z), then the following clauses are all 
+    **         optimized:
+    **
+    **            x=5
+    **            x=5 AND y=10
+    **            x=5 AND y<10
+    **            x=5 AND y>5 AND y<10
+    **            x=5 AND y=5 AND z<=10
+    **
+    **         The z<10 term of the following cannot be used, only
+    **         the x=5 term:
+    **
+    **            x=5 AND z<10
+    **
+    **         N may be zero if there are inequality constraints.
+    **         If there are no inequality constraints, then N is at
+    **         least one.
+    **
+    **         This case is also used when there are no WHERE clause
+    **         constraints but an index is selected anyway, in order
+    **         to force the output order to conform to an ORDER BY.
+    */  
+    static const u8 aStartOp[] = {
+      0,
+      0,
+      OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
+      OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
+      OP_SeekGT,           /* 4: (start_constraints  && !startEq && !bRev) */
+      OP_SeekLT,           /* 5: (start_constraints  && !startEq &&  bRev) */
+      OP_SeekGE,           /* 6: (start_constraints  &&  startEq && !bRev) */
+      OP_SeekLE            /* 7: (start_constraints  &&  startEq &&  bRev) */
+    };
+    static const u8 aEndOp[] = {
+      OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */
+      OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */
+      OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */
+      OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */
+    };
+    u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */
+    int regBase;                 /* Base register holding constraint values */
+    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
+    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
+    int startEq;                 /* True if range start uses ==, >= or <= */
+    int endEq;                   /* True if range end uses ==, >= or <= */
+    int start_constraints;       /* Start of range is constrained */
+    int nConstraint;             /* Number of constraint terms */
+    Index *pIdx;                 /* The index we will be using */
+    int iIdxCur;                 /* The VDBE cursor for the index */
+    int nExtraReg = 0;           /* Number of extra registers needed */
+    int op;                      /* Instruction opcode */
+    char *zStartAff;             /* Affinity for start of range constraint */
+    char cEndAff = 0;            /* Affinity for end of range constraint */
+    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
+    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */
+
+    pIdx = pLoop->u.btree.pIndex;
+    iIdxCur = pLevel->iIdxCur;
+    assert( nEq>=pLoop->nSkip );
+
+    /* If this loop satisfies a sort order (pOrderBy) request that 
+    ** was passed to this function to implement a "SELECT min(x) ..." 
+    ** query, then the caller will only allow the loop to run for
+    ** a single iteration. This means that the first row returned
+    ** should not have a NULL value stored in 'x'. If column 'x' is
+    ** the first one after the nEq equality constraints in the index,
+    ** this requires some special handling.
+    */
+    assert( pWInfo->pOrderBy==0
+         || pWInfo->pOrderBy->nExpr==1
+         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
+    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+     && pWInfo->nOBSat>0
+     && (pIdx->nKeyCol>nEq)
+    ){
+      assert( pLoop->nSkip==0 );
+      bSeekPastNull = 1;
+      nExtraReg = 1;
+    }
+
+    /* Find any inequality constraint terms for the start and end 
+    ** of the range. 
+    */
+    j = nEq;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+      pRangeStart = pLoop->aLTerm[j++];
+      nExtraReg = 1;
+      /* Like optimization range constraints always occur in pairs */
+      assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 
+              (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
+    }
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+      pRangeEnd = pLoop->aLTerm[j++];
+      nExtraReg = 1;
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
+        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
+        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
+        pLevel->iLikeRepCntr = (u32)++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
+        VdbeComment((v, "LIKE loop counter"));
+        pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
+        /* iLikeRepCntr actually stores 2x the counter register number.  The
+        ** bottom bit indicates whether the search order is ASC or DESC. */
+        testcase( bRev );
+        testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
+        assert( (bRev & ~1)==0 );
+        pLevel->iLikeRepCntr <<=1;
+        pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);
+      }
+#endif
+      if( pRangeStart==0
+       && (j = pIdx->aiColumn[nEq])>=0 
+       && pIdx->pTable->aCol[j].notNull==0
+      ){
+        bSeekPastNull = 1;
+      }
+    }
+    assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
+
+    /* If we are doing a reverse order scan on an ascending index, or
+    ** a forward order scan on a descending index, interchange the 
+    ** start and end terms (pRangeStart and pRangeEnd).
+    */
+    if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
+     || (bRev && pIdx->nKeyCol==nEq)
+    ){
+      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+      SWAP(u8, bSeekPastNull, bStopAtNull);
+    }
+
+    /* Generate code to evaluate all constraint terms using == or IN
+    ** and store the values of those terms in an array of registers
+    ** starting at regBase.
+    */
+    codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
+    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
+    assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
+    if( zStartAff ) cEndAff = zStartAff[nEq];
+    addrNxt = pLevel->addrNxt;
+
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
+    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+    start_constraints = pRangeStart || nEq>0;
+
+    /* Seek the index cursor to the start of the range. */
+    nConstraint = nEq;
+    if( pRangeStart ){
+      Expr *pRight = pRangeStart->pExpr->pRight;
+      sqlite3ExprCode(pParse, pRight, regBase+nEq);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
+      if( (pRangeStart->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
+      }
+      if( zStartAff ){
+        if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_BLOB){
+          /* Since the comparison is to be performed with no conversions
+          ** applied to the operands, set the affinity to apply to pRight to 
+          ** SQLITE_AFF_BLOB.  */
+          zStartAff[nEq] = SQLITE_AFF_BLOB;
+        }
+        if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
+          zStartAff[nEq] = SQLITE_AFF_BLOB;
+        }
+      }  
+      nConstraint++;
+      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
+      bSeekPastNull = 0;
+    }else if( bSeekPastNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      nConstraint++;
+      startEq = 0;
+      start_constraints = 1;
+    }
+    codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
+    if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){
+      /* The skip-scan logic inside the call to codeAllEqualityConstraints()
+      ** above has already left the cursor sitting on the correct row,
+      ** so no further seeking is needed */
+    }else{
+      op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+      assert( op!=0 );
+      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+      VdbeCoverage(v);
+      VdbeCoverageIf(v, op==OP_Rewind);  testcase( op==OP_Rewind );
+      VdbeCoverageIf(v, op==OP_Last);    testcase( op==OP_Last );
+      VdbeCoverageIf(v, op==OP_SeekGT);  testcase( op==OP_SeekGT );
+      VdbeCoverageIf(v, op==OP_SeekGE);  testcase( op==OP_SeekGE );
+      VdbeCoverageIf(v, op==OP_SeekLE);  testcase( op==OP_SeekLE );
+      VdbeCoverageIf(v, op==OP_SeekLT);  testcase( op==OP_SeekLT );
+    }
+
+    /* Load the value for the inequality constraint at the end of the
+    ** range (if any).
+    */
+    nConstraint = nEq;
+    if( pRangeEnd ){
+      Expr *pRight = pRangeEnd->pExpr->pRight;
+      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
+      sqlite3ExprCode(pParse, pRight, regBase+nEq);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
+      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
+      }
+      if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_BLOB
+       && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
+      ){
+        codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
+      }
+      nConstraint++;
+      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
+    }else if( bStopAtNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      endEq = 0;
+      nConstraint++;
+    }
+    sqlite3DbFree(db, zStartAff);
+
+    /* Top of the loop body */
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+
+    /* Check if the index cursor is past the end of the range. */
+    if( nConstraint ){
+      op = aEndOp[bRev*2 + endEq];
+      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+      testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );
+      testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
+      testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
+      testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
+    }
+
+    /* Seek the table cursor, if required */
+    disableTerm(pLevel, pRangeStart);
+    disableTerm(pLevel, pRangeEnd);
+    if( omitTable ){
+      /* pIdx is a covering index.  No need to access the main table. */
+    }else if( HasRowid(pIdx->pTable) ){
+      if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE)!=0 ){
+        iRowidReg = ++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
+        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
+        VdbeCoverage(v);
+      }else{
+        codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);
+      }
+    }else if( iCur!=iIdxCur ){
+      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
+      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
+      for(j=0; j<pPk->nKeyCol; j++){
+        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
+      }
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
+                           iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
+    }
+
+    /* Record the instruction used to terminate the loop. Disable 
+    ** WHERE clause terms made redundant by the index range scan.
+    */
+    if( pLoop->wsFlags & WHERE_ONEROW ){
+      pLevel->op = OP_Noop;
+    }else if( bRev ){
+      pLevel->op = OP_Prev;
+    }else{
+      pLevel->op = OP_Next;
+    }
+    pLevel->p1 = iIdxCur;
+    pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
+    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }else{
+      assert( pLevel->p5==0 );
+    }
+  }else
+
+#ifndef SQLITE_OMIT_OR_OPTIMIZATION
+  if( pLoop->wsFlags & WHERE_MULTI_OR ){
+    /* Case 5:  Two or more separately indexed terms connected by OR
+    **
+    ** Example:
+    **
+    **   CREATE TABLE t1(a,b,c,d);
+    **   CREATE INDEX i1 ON t1(a);
+    **   CREATE INDEX i2 ON t1(b);
+    **   CREATE INDEX i3 ON t1(c);
+    **
+    **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
+    **
+    ** In the example, there are three indexed terms connected by OR.
+    ** The top of the loop looks like this:
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **
+    ** Then, for each indexed term, the following. The arguments to
+    ** RowSetTest are such that the rowid of the current row is inserted
+    ** into the RowSet. If it is already present, control skips the
+    ** Gosub opcode and jumps straight to the code generated by WhereEnd().
+    **
+    **        sqlite3WhereBegin(<term>)
+    **          RowSetTest                  # Insert rowid into rowset
+    **          Gosub      2 A
+    **        sqlite3WhereEnd()
+    **
+    ** Following the above, code to terminate the loop. Label A, the target
+    ** of the Gosub above, jumps to the instruction right after the Goto.
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **          Goto       B                # The loop is finished.
+    **
+    **       A: <loop body>                 # Return data, whatever.
+    **
+    **          Return     2                # Jump back to the Gosub
+    **
+    **       B: <after the loop>
+    **
+    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
+    ** use an ephemeral index instead of a RowSet to record the primary
+    ** keys of the rows we have already seen.
+    **
+    */
+    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
+    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
+    Index *pCov = 0;             /* Potential covering index (or NULL) */
+    int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */
+
+    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
+    int regRowset = 0;                        /* Register for RowSet object */
+    int regRowid = 0;                         /* Register holding rowid */
+    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
+    int iRetInit;                             /* Address of regReturn init */
+    int untestedTerms = 0;             /* Some terms not completely tested */
+    int ii;                            /* Loop counter */
+    u16 wctrlFlags;                    /* Flags for sub-WHERE clause */
+    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
+    Table *pTab = pTabItem->pTab;
+   
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->eOperator & WO_OR );
+    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
+    pOrWc = &pTerm->u.pOrInfo->wc;
+    pLevel->op = OP_Return;
+    pLevel->p1 = regReturn;
+
+    /* Set up a new SrcList in pOrTab containing the table being scanned
+    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
+    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
+    */
+    if( pWInfo->nLevel>1 ){
+      int nNotReady;                 /* The number of notReady tables */
+      struct SrcList_item *origSrc;     /* Original list of tables */
+      nNotReady = pWInfo->nLevel - iLevel - 1;
+      pOrTab = sqlite3StackAllocRaw(db,
+                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
+      if( pOrTab==0 ) return notReady;
+      pOrTab->nAlloc = (u8)(nNotReady + 1);
+      pOrTab->nSrc = pOrTab->nAlloc;
+      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
+      origSrc = pWInfo->pTabList->a;
+      for(k=1; k<=nNotReady; k++){
+        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
+      }
+    }else{
+      pOrTab = pWInfo->pTabList;
+    }
+
+    /* Initialize the rowset register to contain NULL. An SQL NULL is 
+    ** equivalent to an empty rowset.  Or, create an ephemeral index
+    ** capable of holding primary keys in the case of a WITHOUT ROWID.
+    **
+    ** Also initialize regReturn to contain the address of the instruction 
+    ** immediately following the OP_Return at the bottom of the loop. This
+    ** is required in a few obscure LEFT JOIN cases where control jumps
+    ** over the top of the loop into the body of it. In this case the 
+    ** correct response for the end-of-loop code (the OP_Return) is to 
+    ** fall through to the next instruction, just as an OP_Next does if
+    ** called on an uninitialized cursor.
+    */
+    if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+      if( HasRowid(pTab) ){
+        regRowset = ++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
+      }else{
+        Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+        regRowset = pParse->nTab++;
+        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
+        sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+      }
+      regRowid = ++pParse->nMem;
+    }
+    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
+
+    /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y
+    ** Then for every term xN, evaluate as the subexpression: xN AND z
+    ** That way, terms in y that are factored into the disjunction will
+    ** be picked up by the recursive calls to sqlite3WhereBegin() below.
+    **
+    ** Actually, each subexpression is converted to "xN AND w" where w is
+    ** the "interesting" terms of z - terms that did not originate in the
+    ** ON or USING clause of a LEFT JOIN, and terms that are usable as 
+    ** indices.
+    **
+    ** This optimization also only applies if the (x1 OR x2 OR ...) term
+    ** is not contained in the ON clause of a LEFT JOIN.
+    ** See ticket http://www.sqlite.org/src/info/f2369304e4
+    */
+    if( pWC->nTerm>1 ){
+      int iTerm;
+      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
+        Expr *pExpr = pWC->a[iTerm].pExpr;
+        if( &pWC->a[iTerm] == pTerm ) continue;
+        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
+        testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
+        testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
+        if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
+        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
+        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
+        pExpr = sqlite3ExprDup(db, pExpr, 0);
+        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
+      }
+      if( pAndExpr ){
+        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr, 0);
+      }
+    }
+
+    /* Run a separate WHERE clause for each term of the OR clause.  After
+    ** eliminating duplicates from other WHERE clauses, the action for each
+    ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
+    */
+    wctrlFlags =  WHERE_OR_SUBCLAUSE | (pWInfo->wctrlFlags & WHERE_SEEK_TABLE);
+    for(ii=0; ii<pOrWc->nTerm; ii++){
+      WhereTerm *pOrTerm = &pOrWc->a[ii];
+      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
+        WhereInfo *pSubWInfo;           /* Info for single OR-term scan */
+        Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
+        int jmp1 = 0;                   /* Address of jump operation */
+        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
+          pAndExpr->pLeft = pOrExpr;
+          pOrExpr = pAndExpr;
+        }
+        /* Loop through table entries that match term pOrTerm. */
+        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
+        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
+                                      wctrlFlags, iCovCur);
+        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
+        if( pSubWInfo ){
+          WhereLoop *pSubLoop;
+          int addrExplain = sqlite3WhereExplainOneScan(
+              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
+          );
+          sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
+
+          /* This is the sub-WHERE clause body.  First skip over
+          ** duplicate rows from prior sub-WHERE clauses, and record the
+          ** rowid (or PRIMARY KEY) for the current row so that the same
+          ** row will be skipped in subsequent sub-WHERE clauses.
+          */
+          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+            int r;
+            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
+            if( HasRowid(pTab) ){
+              r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
+              jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,
+                                           r,iSet);
+              VdbeCoverage(v);
+            }else{
+              Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+              int nPk = pPk->nKeyCol;
+              int iPk;
+
+              /* Read the PK into an array of temp registers. */
+              r = sqlite3GetTempRange(pParse, nPk);
+              for(iPk=0; iPk<nPk; iPk++){
+                int iCol = pPk->aiColumn[iPk];
+                sqlite3ExprCodeGetColumnToReg(pParse, pTab, iCol, iCur, r+iPk);
+              }
+
+              /* Check if the temp table already contains this key. If so,
+              ** the row has already been included in the result set and
+              ** can be ignored (by jumping past the Gosub below). Otherwise,
+              ** insert the key into the temp table and proceed with processing
+              ** the row.
+              **
+              ** Use some of the same optimizations as OP_RowSetTest: If iSet
+              ** is zero, assume that the key cannot already be present in
+              ** the temp table. And if iSet is -1, assume that there is no 
+              ** need to insert the key into the temp table, as it will never 
+              ** be tested for.  */ 
+              if( iSet ){
+                jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
+                VdbeCoverage(v);
+              }
+              if( iSet>=0 ){
+                sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
+                sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0);
+                if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+              }
+
+              /* Release the array of temp registers */
+              sqlite3ReleaseTempRange(pParse, r, nPk);
+            }
+          }
+
+          /* Invoke the main loop body as a subroutine */
+          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+
+          /* Jump here (skipping the main loop body subroutine) if the
+          ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
+          if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);
+
+          /* The pSubWInfo->untestedTerms flag means that this OR term
+          ** contained one or more AND term from a notReady table.  The
+          ** terms from the notReady table could not be tested and will
+          ** need to be tested later.
+          */
+          if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+
+          /* If all of the OR-connected terms are optimized using the same
+          ** index, and the index is opened using the same cursor number
+          ** by each call to sqlite3WhereBegin() made by this loop, it may
+          ** be possible to use that index as a covering index.
+          **
+          ** If the call to sqlite3WhereBegin() above resulted in a scan that
+          ** uses an index, and this is either the first OR-connected term
+          ** processed or the index is the same as that used by all previous
+          ** terms, set pCov to the candidate covering index. Otherwise, set 
+          ** pCov to NULL to indicate that no candidate covering index will 
+          ** be available.
+          */
+          pSubLoop = pSubWInfo->a[0].pWLoop;
+          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
+           && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
+          ){
+            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+            pCov = pSubLoop->u.btree.pIndex;
+          }else{
+            pCov = 0;
+          }
+
+          /* Finish the loop through table entries that match term pOrTerm. */
+          sqlite3WhereEnd(pSubWInfo);
+        }
+      }
+    }
+    pLevel->u.pCovidx = pCov;
+    if( pCov ) pLevel->iIdxCur = iCovCur;
+    if( pAndExpr ){
+      pAndExpr->pLeft = 0;
+      sqlite3ExprDelete(db, pAndExpr);
+    }
+    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
+    sqlite3VdbeGoto(v, pLevel->addrBrk);
+    sqlite3VdbeResolveLabel(v, iLoopBody);
+
+    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
+    if( !untestedTerms ) disableTerm(pLevel, pTerm);
+  }else
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+  {
+    /* Case 6:  There is no usable index.  We must do a complete
+    **          scan of the entire table.
+    */
+    static const u8 aStep[] = { OP_Next, OP_Prev };
+    static const u8 aStart[] = { OP_Rewind, OP_Last };
+    assert( bRev==0 || bRev==1 );
+    if( pTabItem->fg.isRecursive ){
+      /* Tables marked isRecursive have only a single row that is stored in
+      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
+      pLevel->op = OP_Noop;
+    }else{
+      codeCursorHint(pTabItem, pWInfo, pLevel, 0);
+      pLevel->op = aStep[bRev];
+      pLevel->p1 = iCur;
+      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }
   }
-  return mask;
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
+#endif
+
+  /* Insert code to test every subexpression that can be completely
+  ** computed using the current set of tables.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE;
+    int skipLikeAddr = 0;
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    testcase( pTerm->wtFlags & TERM_CODED );
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+      testcase( pWInfo->untestedTerms==0
+               && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
+      pWInfo->untestedTerms = 1;
+      continue;
+    }
+    pE = pTerm->pExpr;
+    assert( pE!=0 );
+    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+      continue;
+    }
+    if( pTerm->wtFlags & TERM_LIKECOND ){
+      /* If the TERM_LIKECOND flag is set, that means that the range search
+      ** is sufficient to guarantee that the LIKE operator is true, so we
+      ** can skip the call to the like(A,B) function.  But this only works
+      ** for strings.  So do not skip the call to the function on the pass
+      ** that compares BLOBs. */
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+      continue;
+#else
+      u32 x = pLevel->iLikeRepCntr;
+      assert( x>0 );
+      skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)? OP_IfNot : OP_If, (int)(x>>1));
+      VdbeCoverage(v);
+#endif
+    }
+    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+    if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
+    pTerm->wtFlags |= TERM_CODED;
+  }
+
+  /* Insert code to test for implied constraints based on transitivity
+  ** of the "==" operator.
+  **
+  ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
+  ** and we are coding the t1 loop and the t2 loop has not yet coded,
+  ** then we cannot use the "t1.a=t2.b" constraint, but we can code
+  ** the implied "t1.a=123" constraint.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE, *pEAlt;
+    WhereTerm *pAlt;
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
+    if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
+    if( pTerm->leftCursor!=iCur ) continue;
+    if( pLevel->iLeftJoin ) continue;
+    pE = pTerm->pExpr;
+    assert( !ExprHasProperty(pE, EP_FromJoin) );
+    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
+    pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
+                    WO_EQ|WO_IN|WO_IS, 0);
+    if( pAlt==0 ) continue;
+    if( pAlt->wtFlags & (TERM_CODED) ) continue;
+    testcase( pAlt->eOperator & WO_EQ );
+    testcase( pAlt->eOperator & WO_IS );
+    testcase( pAlt->eOperator & WO_IN );
+    VdbeModuleComment((v, "begin transitive constraint"));
+    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
+    if( pEAlt ){
+      *pEAlt = *pAlt->pExpr;
+      pEAlt->pLeft = pE->pLeft;
+      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
+      sqlite3StackFree(db, pEAlt);
+    }
+  }
+
+  /* For a LEFT OUTER JOIN, generate code that will record the fact that
+  ** at least one row of the right table has matched the left table.  
+  */
+  if( pLevel->iLeftJoin ){
+    pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+    VdbeComment((v, "record LEFT JOIN hit"));
+    sqlite3ExprCacheClear(pParse);
+    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
+      testcase( pTerm->wtFlags & TERM_CODED );
+      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+        assert( pWInfo->untestedTerms );
+        continue;
+      }
+      assert( pTerm->pExpr );
+      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
+      pTerm->wtFlags |= TERM_CODED;
+    }
+  }
+
+  return pLevel->notReady;
+}
+
+/************** End of wherecode.c *******************************************/
+/************** Begin file whereexpr.c ***************************************/
+/*
+** 2015-06-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.
+**
+** This file was originally part of where.c but was split out to improve
+** readability and editabiliity.  This file contains utility routines for
+** analyzing Expr objects in the WHERE clause.
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declarations */
+static void exprAnalyze(SrcList*, WhereClause*, int);
+
+/*
+** Deallocate all memory associated with a WhereOrInfo object.
+*/
+static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Deallocate all memory associated with a WhereAndInfo object.
+*/
+static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Add a single new WhereTerm entry to the WhereClause object pWC.
+** The new WhereTerm object is constructed from Expr p and with wtFlags.
+** The index in pWC->a[] of the new WhereTerm is returned on success.
+** 0 is returned if the new WhereTerm could not be added due to a memory
+** allocation error.  The memory allocation failure will be recorded in
+** the db->mallocFailed flag so that higher-level functions can detect it.
+**
+** This routine will increase the size of the pWC->a[] array as necessary.
+**
+** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
+** for freeing the expression p is assumed by the WhereClause object pWC.
+** This is true even if this routine fails to allocate a new WhereTerm.
+**
+** WARNING:  This routine might reallocate the space used to store
+** WhereTerms.  All pointers to WhereTerms should be invalidated after
+** calling this routine.  Such pointers may be reinitialized by referencing
+** the pWC->a[] array.
+*/
+static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
+  WhereTerm *pTerm;
+  int idx;
+  testcase( wtFlags & TERM_VIRTUAL );
+  if( pWC->nTerm>=pWC->nSlot ){
+    WhereTerm *pOld = pWC->a;
+    sqlite3 *db = pWC->pWInfo->pParse->db;
+    pWC->a = sqlite3DbMallocRawNN(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
+    if( pWC->a==0 ){
+      if( wtFlags & TERM_DYNAMIC ){
+        sqlite3ExprDelete(db, p);
+      }
+      pWC->a = pOld;
+      return 0;
+    }
+    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
+    if( pOld!=pWC->aStatic ){
+      sqlite3DbFree(db, pOld);
+    }
+    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
+    memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm));
+  }
+  pTerm = &pWC->a[idx = pWC->nTerm++];
+  if( p && ExprHasProperty(p, EP_Unlikely) ){
+    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
+  }else{
+    pTerm->truthProb = 1;
+  }
+  pTerm->pExpr = sqlite3ExprSkipCollate(p);
+  pTerm->wtFlags = wtFlags;
+  pTerm->pWC = pWC;
+  pTerm->iParent = -1;
+  return idx;
 }
 
 /*
 ** Return TRUE if the given operator is one of the operators that is
 ** allowed for an indexable WHERE clause term.  The allowed operators are
-** "=", "<", ">", "<=", ">=", and "IN".
-**
-** IMPLEMENTATION-OF: R-59926-26393 To be usable by an index a term must be
-** of one of the following forms: column = expression column > expression
-** column >= expression column < expression column <= expression
-** expression = column expression > column expression >= column
-** expression < column expression <= column column IN
-** (expression-list) column IN (subquery) column IS NULL
+** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
 */
 static int allowedOp(int op){
   assert( TK_GT>TK_EQ && TK_GT<TK_GE );
   assert( TK_LT>TK_EQ && TK_LT<TK_GE );
   assert( TK_LE>TK_EQ && TK_LE<TK_GE );
   assert( TK_GE==TK_EQ+4 );
-  return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL;
+  return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;
 }
 
 /*
-** Swap two objects of type TYPE.
-*/
-#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
-
-/*
 ** Commute a comparison operator.  Expressions of the form "X op Y"
 ** are converted into "Y op X".
 **
-** If a collation sequence is associated with either the left or right
-** side of the comparison, it remains associated with the same side after
-** the commutation. So "Y collate NOCASE op X" becomes 
-** "X collate NOCASE op Y". This is because any collation sequence on
+** If left/right precedence rules come into play when determining the
+** collating sequence, then COLLATE operators are adjusted to ensure
+** that the collating sequence does not change.  For example:
+** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
 ** the left hand side of a comparison overrides any collation sequence 
-** attached to the right. For the same reason the EP_ExpCollate flag
+** attached to the right. For the same reason the EP_Collate flag
 ** is not commuted.
 */
 static void exprCommute(Parse *pParse, Expr *pExpr){
-  u16 expRight = (pExpr->pRight->flags & EP_ExpCollate);
-  u16 expLeft = (pExpr->pLeft->flags & EP_ExpCollate);
+  u16 expRight = (pExpr->pRight->flags & EP_Collate);
+  u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
   assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
-  pExpr->pRight->pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
-  pExpr->pLeft->pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
-  SWAP(CollSeq*,pExpr->pRight->pColl,pExpr->pLeft->pColl);
-  pExpr->pRight->flags = (pExpr->pRight->flags & ~EP_ExpCollate) | expLeft;
-  pExpr->pLeft->flags = (pExpr->pLeft->flags & ~EP_ExpCollate) | expRight;
+  if( expRight==expLeft ){
+    /* Either X and Y both have COLLATE operator or neither do */
+    if( expRight ){
+      /* Both X and Y have COLLATE operators.  Make sure X is always
+      ** used by clearing the EP_Collate flag from Y. */
+      pExpr->pRight->flags &= ~EP_Collate;
+    }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){
+      /* Neither X nor Y have COLLATE operators, but X has a non-default
+      ** collating sequence.  So add the EP_Collate marker on X to cause
+      ** it to be searched first. */
+      pExpr->pLeft->flags |= EP_Collate;
+    }
+  }
   SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
   if( pExpr->op>=TK_GT ){
     assert( TK_LT==TK_GT+2 );
@@ -101263,6 +125497,8 @@ static u16 operatorMask(int op){
     c = WO_IN;
   }else if( op==TK_ISNULL ){
     c = WO_ISNULL;
+  }else if( op==TK_IS ){
+    c = WO_IS;
   }else{
     assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
     c = (u16)(WO_EQ<<(op-TK_EQ));
@@ -101274,81 +125510,10 @@ static u16 operatorMask(int op){
   assert( op!=TK_LE || c==WO_LE );
   assert( op!=TK_GT || c==WO_GT );
   assert( op!=TK_GE || c==WO_GE );
+  assert( op!=TK_IS || c==WO_IS );
   return c;
 }
 
-/*
-** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
-** where X is a reference to the iColumn of table iCur and <op> is one of
-** the WO_xx operator codes specified by the op parameter.
-** Return a pointer to the term.  Return 0 if not found.
-*/
-static WhereTerm *findTerm(
-  WhereClause *pWC,     /* The WHERE clause to be searched */
-  int iCur,             /* Cursor number of LHS */
-  int iColumn,          /* Column number of LHS */
-  Bitmask notReady,     /* RHS must not overlap with this mask */
-  u32 op,               /* Mask of WO_xx values describing operator */
-  Index *pIdx           /* Must be compatible with this index, if not NULL */
-){
-  WhereTerm *pTerm;
-  int k;
-  assert( iCur>=0 );
-  op &= WO_ALL;
-  for(; pWC; pWC=pWC->pOuter){
-    for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
-      if( pTerm->leftCursor==iCur
-         && (pTerm->prereqRight & notReady)==0
-         && pTerm->u.leftColumn==iColumn
-         && (pTerm->eOperator & op)!=0
-      ){
-        if( pIdx && pTerm->eOperator!=WO_ISNULL ){
-          Expr *pX = pTerm->pExpr;
-          CollSeq *pColl;
-          char idxaff;
-          int j;
-          Parse *pParse = pWC->pParse;
-  
-          idxaff = pIdx->pTable->aCol[iColumn].affinity;
-          if( !sqlite3IndexAffinityOk(pX, idxaff) ) continue;
-  
-          /* Figure out the collation sequence required from an index for
-          ** it to be useful for optimising expression pX. Store this
-          ** value in variable pColl.
-          */
-          assert(pX->pLeft);
-          pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-          assert(pColl || pParse->nErr);
-  
-          for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
-            if( NEVER(j>=pIdx->nColumn) ) return 0;
-          }
-          if( pColl && sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
-        }
-        return pTerm;
-      }
-    }
-  }
-  return 0;
-}
-
-/* Forward reference */
-static void exprAnalyze(SrcList*, WhereClause*, int);
-
-/*
-** Call exprAnalyze on all terms in a WHERE clause.  
-**
-**
-*/
-static void exprAnalyzeAll(
-  SrcList *pTabList,       /* the FROM clause */
-  WhereClause *pWC         /* the WHERE clause to be analyzed */
-){
-  int i;
-  for(i=pWC->nTerm-1; i>=0; i--){
-    exprAnalyze(pTabList, pWC, i);
-  }
-}
 
 #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
 /*
@@ -101357,7 +125522,11 @@ static void exprAnalyzeAll(
 ** so and false if not.
 **
 ** In order for the operator to be optimizible, the RHS must be a string
-** literal that does not begin with a wildcard.  
+** literal that does not begin with a wildcard.  The LHS must be a column
+** that may only be NULL, a string, or a BLOB, never a number. (This means
+** that virtual tables cannot participate in the LIKE optimization.)  The
+** collating sequence for the column on the LHS must be appropriate for
+** the operator.
 */
 static int isLikeOrGlob(
   Parse *pParse,    /* Parsing and code generating context */
@@ -101375,6 +125544,7 @@ static int isLikeOrGlob(
   sqlite3 *db = pParse->db;  /* Database connection */
   sqlite3_value *pVal = 0;
   int op;                    /* Opcode of pRight */
+  int rc;                    /* Result code to return */
 
   if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
     return 0;
@@ -101384,22 +125554,22 @@ static int isLikeOrGlob(
 #endif
   pList = pExpr->x.pList;
   pLeft = pList->a[1].pExpr;
-  if( pLeft->op!=TK_COLUMN || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT ){
+  if( pLeft->op!=TK_COLUMN 
+   || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT 
+   || IsVirtual(pLeft->pTab)  /* Value might be numeric */
+  ){
     /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must
     ** be the name of an indexed column with TEXT affinity. */
     return 0;
   }
   assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */
 
-  pRight = pList->a[0].pExpr;
+  pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
   op = pRight->op;
-  if( op==TK_REGISTER ){
-    op = pRight->op2;
-  }
   if( op==TK_VARIABLE ){
     Vdbe *pReprepare = pParse->pReprepare;
     int iCol = pRight->iColumn;
-    pVal = sqlite3VdbeGetValue(pReprepare, iCol, SQLITE_AFF_NONE);
+    pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);
     if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
       z = (char *)sqlite3_value_text(pVal);
     }
@@ -101427,7 +125597,7 @@ static int isLikeOrGlob(
           ** value of the variable means there is no need to invoke the LIKE
           ** function, then no OP_Variable will be added to the program.
           ** This causes problems for the sqlite3_bind_parameter_name()
-          ** API. To workaround them, add a dummy OP_Variable here.
+          ** API. To work around them, add a dummy OP_Variable here.
           */ 
           int r1 = sqlite3GetTempReg(pParse);
           sqlite3ExprCodeTarget(pParse, pRight, r1);
@@ -101440,8 +125610,9 @@ static int isLikeOrGlob(
     }
   }
 
+  rc = (z!=0);
   sqlite3ValueFree(pVal);
-  return (z!=0);
+  return rc;
 }
 #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
 
@@ -101450,29 +125621,48 @@ static int isLikeOrGlob(
 /*
 ** Check to see if the given expression is of the form
 **
-**         column MATCH expr
+**         column OP expr
+**
+** where OP is one of MATCH, GLOB, LIKE or REGEXP and "column" is a 
+** column of a virtual table.
 **
 ** If it is then return TRUE.  If not, return FALSE.
 */
 static int isMatchOfColumn(
-  Expr *pExpr      /* Test this expression */
-){
+  Expr *pExpr,                    /* Test this expression */
+  unsigned char *peOp2            /* OUT: 0 for MATCH, or else an op2 value */
+){
+  struct Op2 {
+    const char *zOp;
+    unsigned char eOp2;
+  } aOp[] = {
+    { "match",  SQLITE_INDEX_CONSTRAINT_MATCH },
+    { "glob",   SQLITE_INDEX_CONSTRAINT_GLOB },
+    { "like",   SQLITE_INDEX_CONSTRAINT_LIKE },
+    { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }
+  };
   ExprList *pList;
+  Expr *pCol;                     /* Column reference */
+  int i;
 
   if( pExpr->op!=TK_FUNCTION ){
     return 0;
   }
-  if( sqlite3StrICmp(pExpr->u.zToken,"match")!=0 ){
-    return 0;
-  }
   pList = pExpr->x.pList;
-  if( pList->nExpr!=2 ){
+  if( pList==0 || pList->nExpr!=2 ){
     return 0;
   }
-  if( pList->a[1].pExpr->op != TK_COLUMN ){
+  pCol = pList->a[1].pExpr;
+  if( pCol->op!=TK_COLUMN || !IsVirtual(pCol->pTab) ){
     return 0;
   }
-  return 1;
+  for(i=0; i<ArraySize(aOp); i++){
+    if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
+      *peOp2 = aOp[i].eOp2;
+      return 1;
+    }
+  }
+  return 0;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -101481,8 +125671,92 @@ static int isMatchOfColumn(
 ** a join, then transfer the appropriate markings over to derived.
 */
 static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
-  pDerived->flags |= pBase->flags & EP_FromJoin;
-  pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  if( pDerived ){
+    pDerived->flags |= pBase->flags & EP_FromJoin;
+    pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  }
+}
+
+/*
+** Mark term iChild as being a child of term iParent
+*/
+static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
+  pWC->a[iChild].iParent = iParent;
+  pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
+  pWC->a[iParent].nChild++;
+}
+
+/*
+** Return the N-th AND-connected subterm of pTerm.  Or if pTerm is not
+** a conjunction, then return just pTerm when N==0.  If N is exceeds
+** the number of available subterms, return NULL.
+*/
+static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){
+  if( pTerm->eOperator!=WO_AND ){
+    return N==0 ? pTerm : 0;
+  }
+  if( N<pTerm->u.pAndInfo->wc.nTerm ){
+    return &pTerm->u.pAndInfo->wc.a[N];
+  }
+  return 0;
+}
+
+/*
+** Subterms pOne and pTwo are contained within WHERE clause pWC.  The
+** two subterms are in disjunction - they are OR-ed together.
+**
+** If these two terms are both of the form:  "A op B" with the same
+** A and B values but different operators and if the operators are
+** compatible (if one is = and the other is <, for example) then
+** add a new virtual AND term to pWC that is the combination of the
+** two.
+**
+** Some examples:
+**
+**    x<y OR x=y    -->     x<=y
+**    x=y OR x=y    -->     x=y
+**    x<=y OR x<y   -->     x<=y
+**
+** The following is NOT generated:
+**
+**    x<y OR x>y    -->     x!=y     
+*/
+static void whereCombineDisjuncts(
+  SrcList *pSrc,         /* the FROM clause */
+  WhereClause *pWC,      /* The complete WHERE clause */
+  WhereTerm *pOne,       /* First disjunct */
+  WhereTerm *pTwo        /* Second disjunct */
+){
+  u16 eOp = pOne->eOperator | pTwo->eOperator;
+  sqlite3 *db;           /* Database connection (for malloc) */
+  Expr *pNew;            /* New virtual expression */
+  int op;                /* Operator for the combined expression */
+  int idxNew;            /* Index in pWC of the next virtual term */
+
+  if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
+   && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
+  assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
+  assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
+  if( sqlite3ExprCompare(pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
+  if( sqlite3ExprCompare(pOne->pExpr->pRight, pTwo->pExpr->pRight, -1) )return;
+  /* If we reach this point, it means the two subterms can be combined */
+  if( (eOp & (eOp-1))!=0 ){
+    if( eOp & (WO_LT|WO_LE) ){
+      eOp = WO_LE;
+    }else{
+      assert( eOp & (WO_GT|WO_GE) );
+      eOp = WO_GE;
+    }
+  }
+  db = pWC->pWInfo->pParse->db;
+  pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
+  if( pNew==0 ) return;
+  for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }
+  pNew->op = op;
+  idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+  exprAnalyze(pSrc, pWC, idxNew);
 }
 
 #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
@@ -101509,10 +125783,11 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
 **     (C)     t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
 **     (D)     x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
 **     (E)     (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
+**     (F)     x>A OR (x=A AND y>=B)
 **
 ** CASE 1:
 **
-** If all subterms are of the form T.C=expr for some single column of C
+** If all subterms are of the form T.C=expr for some single column of C and
 ** a single table T (as shown in example B above) then create a new virtual
 ** term that is an equivalent IN expression.  In other words, if the term
 ** being analyzed is:
@@ -101525,6 +125800,16 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
 **
 ** CASE 2:
 **
+** If there are exactly two disjuncts and one side has x>A and the other side
+** has x=A (for the same x and A) then add a new virtual conjunct term to the
+** WHERE clause of the form "x>=A".  Example:
+**
+**      x>A OR (x=A AND y>B)    adds:    x>=A
+**
+** The added conjunct can sometimes be helpful in query planning.
+**
+** CASE 3:
+**
 ** If all subterms are indexable by a single table T, then set
 **
 **     WhereTerm.eOperator              =  WO_OR
@@ -101541,25 +125826,25 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
 ** From another point of view, "indexable" means that the subterm could
 ** potentially be used with an index if an appropriate index exists.
 ** This analysis does not consider whether or not the index exists; that
-** is something the bestIndex() routine will determine.  This analysis
-** only looks at whether subterms appropriate for indexing exist.
+** is decided elsewhere.  This analysis only looks at whether subterms
+** appropriate for indexing exist.
 **
-** All examples A through E above all satisfy case 2.  But if a term
-** also statisfies case 1 (such as B) we know that the optimizer will
-** always prefer case 1, so in that case we pretend that case 2 is not
+** All examples A through E above satisfy case 3.  But if a term
+** also satisfies case 1 (such as B) we know that the optimizer will
+** always prefer case 1, so in that case we pretend that case 3 is not
 ** satisfied.
 **
 ** It might be the case that multiple tables are indexable.  For example,
 ** (E) above is indexable on tables P, Q, and R.
 **
-** Terms that satisfy case 2 are candidates for lookup by using
+** Terms that satisfy case 3 are candidates for lookup by using
 ** separate indices to find rowids for each subterm and composing
 ** the union of all rowids using a RowSet object.  This is similar
 ** to "bitmap indices" in other database engines.
 **
 ** OTHERWISE:
 **
-** If neither case 1 nor case 2 apply, then leave the eOperator set to
+** If none of cases 1, 2, or 3 apply, then leave the eOperator set to
 ** zero.  This term is not useful for search.
 */
 static void exprAnalyzeOrTerm(
@@ -101567,11 +125852,11 @@ static void exprAnalyzeOrTerm(
   WhereClause *pWC,         /* the complete WHERE clause */
   int idxTerm               /* Index of the OR-term to be analyzed */
 ){
-  Parse *pParse = pWC->pParse;            /* Parser context */
+  WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */
+  Parse *pParse = pWInfo->pParse;         /* Parser context */
   sqlite3 *db = pParse->db;               /* Database connection */
   WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */
   Expr *pExpr = pTerm->pExpr;             /* The expression of the term */
-  WhereMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */
   int i;                                  /* Loop counters */
   WhereClause *pOrWc;       /* Breakup of pTerm into subterms */
   WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */
@@ -101590,24 +125875,24 @@ static void exprAnalyzeOrTerm(
   if( pOrInfo==0 ) return;
   pTerm->wtFlags |= TERM_ORINFO;
   pOrWc = &pOrInfo->wc;
-  whereClauseInit(pOrWc, pWC->pParse, pMaskSet, pWC->wctrlFlags);
-  whereSplit(pOrWc, pExpr, TK_OR);
-  exprAnalyzeAll(pSrc, pOrWc);
+  memset(pOrWc->aStatic, 0, sizeof(pOrWc->aStatic));
+  sqlite3WhereClauseInit(pOrWc, pWInfo);
+  sqlite3WhereSplit(pOrWc, pExpr, TK_OR);
+  sqlite3WhereExprAnalyze(pSrc, pOrWc);
   if( db->mallocFailed ) return;
   assert( pOrWc->nTerm>=2 );
 
   /*
-  ** Compute the set of tables that might satisfy cases 1 or 2.
+  ** Compute the set of tables that might satisfy cases 1 or 3.
   */
   indexable = ~(Bitmask)0;
-  chngToIN = ~(pWC->vmask);
+  chngToIN = ~(Bitmask)0;
   for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
     if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
       WhereAndInfo *pAndInfo;
-      assert( pOrTerm->eOperator==0 );
       assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
       chngToIN = 0;
-      pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
+      pAndInfo = sqlite3DbMallocRawNN(db, sizeof(*pAndInfo));
       if( pAndInfo ){
         WhereClause *pAndWC;
         WhereTerm *pAndTerm;
@@ -101617,16 +125902,18 @@ static void exprAnalyzeOrTerm(
         pOrTerm->wtFlags |= TERM_ANDINFO;
         pOrTerm->eOperator = WO_AND;
         pAndWC = &pAndInfo->wc;
-        whereClauseInit(pAndWC, pWC->pParse, pMaskSet, pWC->wctrlFlags);
-        whereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
-        exprAnalyzeAll(pSrc, pAndWC);
+        memset(pAndWC->aStatic, 0, sizeof(pAndWC->aStatic));
+        sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
+        sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
+        sqlite3WhereExprAnalyze(pSrc, pAndWC);
         pAndWC->pOuter = pWC;
-        testcase( db->mallocFailed );
         if( !db->mallocFailed ){
           for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
             assert( pAndTerm->pExpr );
-            if( allowedOp(pAndTerm->pExpr->op) ){
-              b |= getMask(pMaskSet, pAndTerm->leftCursor);
+            if( allowedOp(pAndTerm->pExpr->op) 
+             || pAndTerm->eOperator==WO_MATCH 
+            ){
+              b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
             }
           }
         }
@@ -101637,13 +125924,13 @@ static void exprAnalyzeOrTerm(
       ** corresponding TERM_VIRTUAL term */
     }else{
       Bitmask b;
-      b = getMask(pMaskSet, pOrTerm->leftCursor);
+      b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
       if( pOrTerm->wtFlags & TERM_VIRTUAL ){
         WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
-        b |= getMask(pMaskSet, pOther->leftCursor);
+        b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
       }
       indexable &= b;
-      if( pOrTerm->eOperator!=WO_EQ ){
+      if( (pOrTerm->eOperator & WO_EQ)==0 ){
         chngToIN = 0;
       }else{
         chngToIN &= b;
@@ -101652,12 +125939,26 @@ static void exprAnalyzeOrTerm(
   }
 
   /*
-  ** Record the set of tables that satisfy case 2.  The set might be
+  ** Record the set of tables that satisfy case 3.  The set might be
   ** empty.
   */
   pOrInfo->indexable = indexable;
   pTerm->eOperator = indexable==0 ? 0 : WO_OR;
 
+  /* For a two-way OR, attempt to implementation case 2.
+  */
+  if( indexable && pOrWc->nTerm==2 ){
+    int iOne = 0;
+    WhereTerm *pOne;
+    while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){
+      int iTwo = 0;
+      WhereTerm *pTwo;
+      while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){
+        whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);
+      }
+    }
+  }
+
   /*
   ** chngToIN holds a set of tables that *might* satisfy case 1.  But
   ** we have to do some additional checking to see if case 1 really
@@ -101694,7 +125995,7 @@ static void exprAnalyzeOrTerm(
     for(j=0; j<2 && !okToChngToIN; j++){
       pOrTerm = pOrWc->a;
       for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         pOrTerm->wtFlags &= ~TERM_OR_OK;
         if( pOrTerm->leftCursor==iCursor ){
           /* This is the 2-bit case and we are on the second iteration and
@@ -101702,9 +126003,10 @@ static void exprAnalyzeOrTerm(
           assert( j==1 );
           continue;
         }
-        if( (chngToIN & getMask(pMaskSet, pOrTerm->leftCursor))==0 ){
+        if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,
+                                            pOrTerm->leftCursor))==0 ){
           /* This term must be of the form t1.a==t2.b where t2 is in the
-          ** chngToIN set but t1 is not.  This term will be either preceeded
+          ** chngToIN set but t1 is not.  This term will be either preceded
           ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
           ** and use its inversion. */
           testcase( pOrTerm->wtFlags & TERM_COPIED );
@@ -101720,8 +126022,8 @@ static void exprAnalyzeOrTerm(
         /* No candidate table+column was found.  This can only occur
         ** on the second iteration */
         assert( j==1 );
-        assert( (chngToIN&(chngToIN-1))==0 );
-        assert( chngToIN==getMask(pMaskSet, iCursor) );
+        assert( IsPowerOfTwo(chngToIN) );
+        assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
         break;
       }
       testcase( j==1 );
@@ -101730,7 +126032,7 @@ static void exprAnalyzeOrTerm(
       ** table and column is common to every term in the OR clause */
       okToChngToIN = 1;
       for(; i>=0 && okToChngToIN; i--, pOrTerm++){
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         if( pOrTerm->leftCursor!=iCursor ){
           pOrTerm->wtFlags &= ~TERM_OR_OK;
         }else if( pOrTerm->u.leftColumn!=iColumn ){
@@ -101755,8 +126057,6 @@ static void exprAnalyzeOrTerm(
     /* At this point, okToChngToIN is true if original pTerm satisfies
     ** case 1.  In that case, construct a new virtual term that is 
     ** pTerm converted into an IN operator.
-    **
-    ** EV: R-00211-15100
     */
     if( okToChngToIN ){
       Expr *pDup;            /* A transient duplicate expression */
@@ -101766,11 +126066,11 @@ static void exprAnalyzeOrTerm(
 
       for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
         if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
-        assert( pOrTerm->eOperator==WO_EQ );
+        assert( pOrTerm->eOperator & WO_EQ );
         assert( pOrTerm->leftCursor==iCursor );
         assert( pOrTerm->u.leftColumn==iColumn );
         pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
-        pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup);
+        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
         pLeft = pOrTerm->pExpr->pLeft;
       }
       assert( pLeft!=0 );
@@ -101785,17 +126085,124 @@ static void exprAnalyzeOrTerm(
         testcase( idxNew==0 );
         exprAnalyze(pSrc, pWC, idxNew);
         pTerm = &pWC->a[idxTerm];
-        pWC->a[idxNew].iParent = idxTerm;
-        pTerm->nChild = 1;
+        markTermAsChild(pWC, idxNew, idxTerm);
       }else{
         sqlite3ExprListDelete(db, pList);
       }
-      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 2 */
+      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 3 */
     }
   }
 }
 #endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
 
+/*
+** We already know that pExpr is a binary operator where both operands are
+** column references.  This routine checks to see if pExpr is an equivalence
+** relation:
+**   1.  The SQLITE_Transitive optimization must be enabled
+**   2.  Must be either an == or an IS operator
+**   3.  Not originating in the ON clause of an OUTER JOIN
+**   4.  The affinities of A and B must be compatible
+**   5a. Both operands use the same collating sequence OR
+**   5b. The overall collating sequence is BINARY
+** If this routine returns TRUE, that means that the RHS can be substituted
+** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
+** This is an optimization.  No harm comes from returning 0.  But if 1 is
+** returned when it should not be, then incorrect answers might result.
+*/
+static int termIsEquivalence(Parse *pParse, Expr *pExpr){
+  char aff1, aff2;
+  CollSeq *pColl;
+  const char *zColl1, *zColl2;
+  if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
+  if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
+  if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
+  aff1 = sqlite3ExprAffinity(pExpr->pLeft);
+  aff2 = sqlite3ExprAffinity(pExpr->pRight);
+  if( aff1!=aff2
+   && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
+  ){
+    return 0;
+  }
+  pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
+  if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+  zColl1 = pColl ? pColl->zName : 0;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
+  zColl2 = pColl ? pColl->zName : 0;
+  return sqlite3_stricmp(zColl1, zColl2)==0;
+}
+
+/*
+** Recursively walk the expressions of a SELECT statement and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
+*/
+static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){
+  Bitmask mask = 0;
+  while( pS ){
+    SrcList *pSrc = pS->pSrc;
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
+    if( ALWAYS(pSrc!=0) ){
+      int i;
+      for(i=0; i<pSrc->nSrc; i++){
+        mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);
+        mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
+      }
+    }
+    pS = pS->pPrior;
+  }
+  return mask;
+}
+
+/*
+** Expression pExpr is one operand of a comparison operator that might
+** be useful for indexing.  This routine checks to see if pExpr appears
+** in any index.  Return TRUE (1) if pExpr is an indexed term and return
+** FALSE (0) if not.  If TRUE is returned, also set *piCur to the cursor
+** number of the table that is indexed and *piColumn to the column number
+** of the column that is indexed, or -2 if an expression is being indexed.
+**
+** If pExpr is a TK_COLUMN column reference, then this routine always returns
+** true even if that particular column is not indexed, because the column
+** might be added to an automatic index later.
+*/
+static int exprMightBeIndexed(
+  SrcList *pFrom,        /* The FROM clause */
+  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
+  Expr *pExpr,           /* An operand of a comparison operator */
+  int *piCur,            /* Write the referenced table cursor number here */
+  int *piColumn          /* Write the referenced table column number here */
+){
+  Index *pIdx;
+  int i;
+  int iCur;
+  if( pExpr->op==TK_COLUMN ){
+    *piCur = pExpr->iTable;
+    *piColumn = pExpr->iColumn;
+    return 1;
+  }
+  if( mPrereq==0 ) return 0;                 /* No table references */
+  if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */
+  for(i=0; mPrereq>1; i++, mPrereq>>=1){}
+  iCur = pFrom->a[i].iCursor;
+  for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    if( pIdx->aColExpr==0 ) continue;
+    for(i=0; i<pIdx->nKeyCol; i++){
+      if( pIdx->aiColumn[i]!=(-2) ) continue;
+      if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
+        *piCur = iCur;
+        *piColumn = -2;
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
 
 /*
 ** The input to this routine is an WhereTerm structure with only the
@@ -101820,6 +126227,7 @@ static void exprAnalyze(
   WhereClause *pWC,         /* the WHERE clause */
   int idxTerm               /* Index of the term to be analyzed */
 ){
+  WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
   WhereTerm *pTerm;                /* The term to be analyzed */
   WhereMaskSet *pMaskSet;          /* Set of table index masks */
   Expr *pExpr;                     /* The expression to be analyzed */
@@ -101828,34 +126236,36 @@ static void exprAnalyze(
   Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
   Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
   int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
-  int noCase = 0;                  /* LIKE/GLOB distinguishes case */
+  int noCase = 0;                  /* uppercase equivalent to lowercase */
   int op;                          /* Top-level operator.  pExpr->op */
-  Parse *pParse = pWC->pParse;     /* Parsing context */
+  Parse *pParse = pWInfo->pParse;  /* Parsing context */
   sqlite3 *db = pParse->db;        /* Database connection */
+  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */
 
   if( db->mallocFailed ){
     return;
   }
   pTerm = &pWC->a[idxTerm];
-  pMaskSet = pWC->pMaskSet;
+  pMaskSet = &pWInfo->sMaskSet;
   pExpr = pTerm->pExpr;
-  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
+  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
+  prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
   op = pExpr->op;
   if( op==TK_IN ){
     assert( pExpr->pRight==0 );
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      pTerm->prereqRight = exprSelectTableUsage(pMaskSet, pExpr->x.pSelect);
+      pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
     }else{
-      pTerm->prereqRight = exprListTableUsage(pMaskSet, pExpr->x.pList);
+      pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
     }
   }else if( op==TK_ISNULL ){
     pTerm->prereqRight = 0;
   }else{
-    pTerm->prereqRight = exprTableUsage(pMaskSet, pExpr->pRight);
+    pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
   }
-  prereqAll = exprTableUsage(pMaskSet, pExpr);
+  prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr);
   if( ExprHasProperty(pExpr, EP_FromJoin) ){
-    Bitmask x = getMask(pMaskSet, pExpr->iRightJoinTable);
+    Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
     prereqAll |= x;
     extraRight = x-1;  /* ON clause terms may not be used with an index
                        ** on left table of a LEFT JOIN.  Ticket #3015 */
@@ -101864,17 +126274,23 @@ static void exprAnalyze(
   pTerm->leftCursor = -1;
   pTerm->iParent = -1;
   pTerm->eOperator = 0;
-  if( allowedOp(op) && (pTerm->prereqRight & prereqLeft)==0 ){
-    Expr *pLeft = pExpr->pLeft;
-    Expr *pRight = pExpr->pRight;
-    if( pLeft->op==TK_COLUMN ){
-      pTerm->leftCursor = pLeft->iTable;
-      pTerm->u.leftColumn = pLeft->iColumn;
-      pTerm->eOperator = operatorMask(op);
-    }
-    if( pRight && pRight->op==TK_COLUMN ){
+  if( allowedOp(op) ){
+    int iCur, iColumn;
+    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
+    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
+    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
+    if( exprMightBeIndexed(pSrc, prereqLeft, pLeft, &iCur, &iColumn) ){
+      pTerm->leftCursor = iCur;
+      pTerm->u.leftColumn = iColumn;
+      pTerm->eOperator = operatorMask(op) & opMask;
+    }
+    if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
+    if( pRight 
+     && exprMightBeIndexed(pSrc, pTerm->prereqRight, pRight, &iCur, &iColumn)
+    ){
       WhereTerm *pNew;
       Expr *pDup;
+      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
       if( pTerm->leftCursor>=0 ){
         int idxNew;
         pDup = sqlite3ExprDup(db, pExpr, 0);
@@ -101885,22 +126301,26 @@ static void exprAnalyze(
         idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
         if( idxNew==0 ) return;
         pNew = &pWC->a[idxNew];
-        pNew->iParent = idxTerm;
+        markTermAsChild(pWC, idxNew, idxTerm);
+        if( op==TK_IS ) pNew->wtFlags |= TERM_IS;
         pTerm = &pWC->a[idxTerm];
-        pTerm->nChild = 1;
         pTerm->wtFlags |= TERM_COPIED;
+
+        if( termIsEquivalence(pParse, pDup) ){
+          pTerm->eOperator |= WO_EQUIV;
+          eExtraOp = WO_EQUIV;
+        }
       }else{
         pDup = pExpr;
         pNew = pTerm;
       }
       exprCommute(pParse, pDup);
-      pLeft = pDup->pLeft;
-      pNew->leftCursor = pLeft->iTable;
-      pNew->u.leftColumn = pLeft->iColumn;
+      pNew->leftCursor = iCur;
+      pNew->u.leftColumn = iColumn;
       testcase( (prereqLeft | extraRight) != prereqLeft );
       pNew->prereqRight = prereqLeft | extraRight;
       pNew->prereqAll = prereqAll;
-      pNew->eOperator = operatorMask(pDup->op);
+      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
     }
   }
 
@@ -101932,13 +126352,13 @@ static void exprAnalyze(
       pNewExpr = sqlite3PExpr(pParse, ops[i], 
                              sqlite3ExprDup(db, pExpr->pLeft, 0),
                              sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
+      transferJoinMarkings(pNewExpr, pExpr);
       idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
       testcase( idxNew==0 );
       exprAnalyze(pSrc, pWC, idxNew);
       pTerm = &pWC->a[idxTerm];
-      pWC->a[idxNew].iParent = idxTerm;
+      markTermAsChild(pWC, idxNew, idxTerm);
     }
-    pTerm->nChild = 2;
   }
 #endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
 
@@ -101957,12 +126377,15 @@ static void exprAnalyze(
   /* Add constraints to reduce the search space on a LIKE or GLOB
   ** operator.
   **
-  ** A like pattern of the form "x LIKE 'abc%'" is changed into constraints
+  ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints
   **
-  **          x>='abc' AND x<'abd' AND x LIKE 'abc%'
+  **          x>='ABC' AND x<'abd' AND x LIKE 'aBc%'
   **
   ** The last character of the prefix "abc" is incremented to form the
-  ** termination condition "abd".
+  ** termination condition "abd".  If case is not significant (the default
+  ** for LIKE) then the lower-bound is made all uppercase and the upper-
+  ** bound is made all lowercase so that the bounds also work when comparing
+  ** BLOBs.
   */
   if( pWC->op==TK_AND 
    && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
@@ -101973,10 +126396,26 @@ static void exprAnalyze(
     Expr *pNewExpr2;
     int idxNew1;
     int idxNew2;
-    CollSeq *pColl;    /* Collating sequence to use */
+    const char *zCollSeqName;     /* Name of collating sequence */
+    const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;
 
     pLeft = pExpr->x.pList->a[1].pExpr;
     pStr2 = sqlite3ExprDup(db, pStr1, 0);
+
+    /* Convert the lower bound to upper-case and the upper bound to
+    ** lower-case (upper-case is less than lower-case in ASCII) so that
+    ** the range constraints also work for BLOBs
+    */
+    if( noCase && !pParse->db->mallocFailed ){
+      int i;
+      char c;
+      pTerm->wtFlags |= TERM_LIKE;
+      for(i=0; (c = pStr1->u.zToken[i])!=0; i++){
+        pStr1->u.zToken[i] = sqlite3Toupper(c);
+        pStr2->u.zToken[i] = sqlite3Tolower(c);
+      }
+    }
+
     if( !db->mallocFailed ){
       u8 c, *pC;       /* Last character before the first wildcard */
       pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
@@ -101988,31 +126427,32 @@ static void exprAnalyze(
         ** inequality.  To avoid this, make sure to also run the full
         ** LIKE on all candidate expressions by clearing the isComplete flag
         */
-        if( c=='A'-1 ) isComplete = 0;   /* EV: R-64339-08207 */
-
-
+        if( c=='A'-1 ) isComplete = 0;
         c = sqlite3UpperToLower[c];
       }
       *pC = c + 1;
     }
-    pColl = sqlite3FindCollSeq(db, SQLITE_UTF8, noCase ? "NOCASE" : "BINARY",0);
-    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 
-                     sqlite3ExprSetColl(sqlite3ExprDup(db,pLeft,0), pColl),
-                     pStr1, 0);
-    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
+    zCollSeqName = noCase ? "NOCASE" : "BINARY";
+    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
+    pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
+           sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
+           pStr1, 0);
+    transferJoinMarkings(pNewExpr1, pExpr);
+    idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
     testcase( idxNew1==0 );
     exprAnalyze(pSrc, pWC, idxNew1);
+    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
     pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
-                     sqlite3ExprSetColl(sqlite3ExprDup(db,pLeft,0), pColl),
-                     pStr2, 0);
-    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
+           sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),
+           pStr2, 0);
+    transferJoinMarkings(pNewExpr2, pExpr);
+    idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);
     testcase( idxNew2==0 );
     exprAnalyze(pSrc, pWC, idxNew2);
     pTerm = &pWC->a[idxTerm];
     if( isComplete ){
-      pWC->a[idxNew1].iParent = idxTerm;
-      pWC->a[idxNew2].iParent = idxTerm;
-      pTerm->nChild = 2;
+      markTermAsChild(pWC, idxNew1, idxTerm);
+      markTermAsChild(pWC, idxNew2, idxTerm);
     }
   }
 #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
@@ -102024,7 +126464,7 @@ static void exprAnalyze(
   ** virtual tables.  The native query optimizer does not attempt
   ** to do anything with MATCH functions.
   */
-  if( isMatchOfColumn(pExpr) ){
+  if( pWC->op==TK_AND && isMatchOfColumn(pExpr, &eOp2) ){
     int idxNew;
     Expr *pRight, *pLeft;
     WhereTerm *pNewTerm;
@@ -102032,8 +126472,8 @@ static void exprAnalyze(
 
     pRight = pExpr->x.pList->a[0].pExpr;
     pLeft = pExpr->x.pList->a[1].pExpr;
-    prereqExpr = exprTableUsage(pMaskSet, pRight);
-    prereqColumn = exprTableUsage(pMaskSet, pLeft);
+    prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
+    prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
     if( (prereqExpr & prereqColumn)==0 ){
       Expr *pNewExpr;
       pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 
@@ -102045,29 +126485,27 @@ static void exprAnalyze(
       pNewTerm->leftCursor = pLeft->iTable;
       pNewTerm->u.leftColumn = pLeft->iColumn;
       pNewTerm->eOperator = WO_MATCH;
-      pNewTerm->iParent = idxTerm;
+      pNewTerm->eMatchOp = eOp2;
+      markTermAsChild(pWC, idxNew, idxTerm);
       pTerm = &pWC->a[idxTerm];
-      pTerm->nChild = 1;
       pTerm->wtFlags |= TERM_COPIED;
       pNewTerm->prereqAll = pTerm->prereqAll;
     }
   }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
   /* When sqlite_stat3 histogram data is available an operator of the
   ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
   ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
   ** virtual term of that form.
   **
-  ** Note that the virtual term must be tagged with TERM_VNULL.  This
-  ** TERM_VNULL tag will suppress the not-null check at the beginning
-  ** of the loop.  Without the TERM_VNULL flag, the not-null check at
-  ** the start of the loop will prevent any results from being returned.
+  ** Note that the virtual term must be tagged with TERM_VNULL.
   */
   if( pExpr->op==TK_NOTNULL
    && pExpr->pLeft->op==TK_COLUMN
    && pExpr->pLeft->iColumn>=0
+   && OptimizationEnabled(db, SQLITE_Stat34)
   ){
     Expr *pNewExpr;
     Expr *pLeft = pExpr->pLeft;
@@ -102086,14 +126524,13 @@ static void exprAnalyze(
       pNewTerm->leftCursor = pLeft->iTable;
       pNewTerm->u.leftColumn = pLeft->iColumn;
       pNewTerm->eOperator = WO_GT;
-      pNewTerm->iParent = idxTerm;
+      markTermAsChild(pWC, idxNew, idxTerm);
       pTerm = &pWC->a[idxTerm];
-      pTerm->nChild = 1;
       pTerm->wtFlags |= TERM_COPIED;
       pNewTerm->prereqAll = pTerm->prereqAll;
     }
   }
-#endif /* SQLITE_ENABLE_STAT */
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
   /* Prevent ON clause terms of a LEFT JOIN from being used to drive
   ** an index for tables to the left of the join.
@@ -102101,31 +126538,551 @@ static void exprAnalyze(
   pTerm->prereqRight |= extraRight;
 }
 
+/***************************************************************************
+** Routines with file scope above.  Interface to the rest of the where.c
+** subsystem follows.
+***************************************************************************/
+
 /*
-** Return TRUE if any of the expressions in pList->a[iFirst...] contain
-** a reference to any table other than the iBase table.
+** This routine identifies subexpressions in the WHERE clause where
+** each subexpression is separated by the AND operator or some other
+** operator specified in the op parameter.  The WhereClause structure
+** is filled with pointers to subexpressions.  For example:
+**
+**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
+**           \________/     \_______________/     \________________/
+**            slot[0]            slot[1]               slot[2]
+**
+** The original WHERE clause in pExpr is unaltered.  All this routine
+** does is make slot[] entries point to substructure within pExpr.
+**
+** In the previous sentence and in the diagram, "slot[]" refers to
+** the WhereClause.a[] array.  The slot[] array grows as needed to contain
+** all terms of the WHERE clause.
 */
-static int referencesOtherTables(
-  ExprList *pList,          /* Search expressions in ths list */
-  WhereMaskSet *pMaskSet,   /* Mapping from tables to bitmaps */
-  int iFirst,               /* Be searching with the iFirst-th expression */
-  int iBase                 /* Ignore references to this table */
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
+  Expr *pE2 = sqlite3ExprSkipCollate(pExpr);
+  pWC->op = op;
+  if( pE2==0 ) return;
+  if( pE2->op!=op ){
+    whereClauseInsert(pWC, pExpr, 0);
+  }else{
+    sqlite3WhereSplit(pWC, pE2->pLeft, op);
+    sqlite3WhereSplit(pWC, pE2->pRight, op);
+  }
+}
+
+/*
+** Initialize a preallocated WhereClause structure.
+*/
+SQLITE_PRIVATE void sqlite3WhereClauseInit(
+  WhereClause *pWC,        /* The WhereClause to be initialized */
+  WhereInfo *pWInfo        /* The WHERE processing context */
 ){
-  Bitmask allowed = ~getMask(pMaskSet, iBase);
-  while( iFirst<pList->nExpr ){
-    if( (exprTableUsage(pMaskSet, pList->a[iFirst++].pExpr)&allowed)!=0 ){
-      return 1;
+  pWC->pWInfo = pWInfo;
+  pWC->pOuter = 0;
+  pWC->nTerm = 0;
+  pWC->nSlot = ArraySize(pWC->aStatic);
+  pWC->a = pWC->aStatic;
+}
+
+/*
+** Deallocate a WhereClause structure.  The WhereClause structure
+** itself is not freed.  This routine is the inverse of
+** sqlite3WhereClauseInit().
+*/
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause *pWC){
+  int i;
+  WhereTerm *a;
+  sqlite3 *db = pWC->pWInfo->pParse->db;
+  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
+    if( a->wtFlags & TERM_DYNAMIC ){
+      sqlite3ExprDelete(db, a->pExpr);
+    }
+    if( a->wtFlags & TERM_ORINFO ){
+      whereOrInfoDelete(db, a->u.pOrInfo);
+    }else if( a->wtFlags & TERM_ANDINFO ){
+      whereAndInfoDelete(db, a->u.pAndInfo);
+    }
+  }
+  if( pWC->a!=pWC->aStatic ){
+    sqlite3DbFree(db, pWC->a);
+  }
+}
+
+
+/*
+** These routines walk (recursively) an expression tree and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
+  Bitmask mask = 0;
+  if( p==0 ) return 0;
+  if( p->op==TK_COLUMN ){
+    mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
+    return mask;
+  }
+  mask = sqlite3WhereExprUsage(pMaskSet, p->pRight);
+  if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
+  if( ExprHasProperty(p, EP_xIsSelect) ){
+    mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
+  }else if( p->x.pList ){
+    mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
+  }
+  return mask;
+}
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
+  int i;
+  Bitmask mask = 0;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+      mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
+    }
+  }
+  return mask;
+}
+
+
+/*
+** Call exprAnalyze on all terms in a WHERE clause.  
+**
+** Note that exprAnalyze() might add new virtual terms onto the
+** end of the WHERE clause.  We do not want to analyze these new
+** virtual terms, so start analyzing at the end and work forward
+** so that the added virtual terms are never processed.
+*/
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(
+  SrcList *pTabList,       /* the FROM clause */
+  WhereClause *pWC         /* the WHERE clause to be analyzed */
+){
+  int i;
+  for(i=pWC->nTerm-1; i>=0; i--){
+    exprAnalyze(pTabList, pWC, i);
+  }
+}
+
+/*
+** For table-valued-functions, transform the function arguments into
+** new WHERE clause terms.  
+**
+** Each function argument translates into an equality constraint against
+** a HIDDEN column in the table.
+*/
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(
+  Parse *pParse,                    /* Parsing context */
+  struct SrcList_item *pItem,       /* The FROM clause term to process */
+  WhereClause *pWC                  /* Xfer function arguments to here */
+){
+  Table *pTab;
+  int j, k;
+  ExprList *pArgs;
+  Expr *pColRef;
+  Expr *pTerm;
+  if( pItem->fg.isTabFunc==0 ) return;
+  pTab = pItem->pTab;
+  assert( pTab!=0 );
+  pArgs = pItem->u1.pFuncArg;
+  if( pArgs==0 ) return;
+  for(j=k=0; j<pArgs->nExpr; j++){
+    while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
+    if( k>=pTab->nCol ){
+      sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
+                      pTab->zName, j);
+      return;
+    }
+    pColRef = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
+    if( pColRef==0 ) return;
+    pColRef->iTable = pItem->iCursor;
+    pColRef->iColumn = k++;
+    pColRef->pTab = pTab;
+    pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef,
+                         sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
+    whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
+  }
+}
+
+/************** End of whereexpr.c *******************************************/
+/************** Begin file where.c *******************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.  This module is responsible for
+** generating the code that loops through a table looking for applicable
+** rows.  Indices are selected and used to speed the search when doing
+** so is applicable.  Because this module is responsible for selecting
+** indices, you might also think of this module as the "query optimizer".
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/* Test variable that can be set to enable WHERE tracing */
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+/***/ int sqlite3WhereTrace = 0;
+#endif
+
+
+/*
+** Return the estimated number of output rows from a WHERE clause
+*/
+SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
+  return pWInfo->nRowOut;
+}
+
+/*
+** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
+** WHERE clause returns outputs for DISTINCT processing.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
+  return pWInfo->eDistinct;
+}
+
+/*
+** Return TRUE if the WHERE clause returns rows in ORDER BY order.
+** Return FALSE if the output needs to be sorted.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
+  return pWInfo->nOBSat;
+}
+
+/*
+** Return TRUE if the innermost loop of the WHERE clause implementation
+** returns rows in ORDER BY order for complete run of the inner loop.
+**
+** Across multiple iterations of outer loops, the output rows need not be
+** sorted.  As long as rows are sorted for just the innermost loop, this
+** routine can return TRUE.
+*/
+SQLITE_PRIVATE int sqlite3WhereOrderedInnerLoop(WhereInfo *pWInfo){
+  return pWInfo->bOrderedInnerLoop;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to continue
+** immediately with the next row of a WHERE clause.
+*/
+SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
+  assert( pWInfo->iContinue!=0 );
+  return pWInfo->iContinue;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to break
+** out of a WHERE loop.
+*/
+SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
+  return pWInfo->iBreak;
+}
+
+/*
+** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to
+** operate directly on the rowis returned by a WHERE clause.  Return
+** ONEPASS_SINGLE (1) if the statement can operation directly because only
+** a single row is to be changed.  Return ONEPASS_MULTI (2) if the one-pass
+** optimization can be used on multiple 
+**
+** If the ONEPASS optimization is used (if this routine returns true)
+** then also write the indices of open cursors used by ONEPASS
+** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
+** table and iaCur[1] gets the cursor used by an auxiliary index.
+** Either value may be -1, indicating that cursor is not used.
+** Any cursors returned will have been opened for writing.
+**
+** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
+** unable to use the ONEPASS optimization.
+*/
+SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
+  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){
+    sqlite3DebugPrintf("%s cursors: %d %d\n",
+         pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",
+         aiCur[0], aiCur[1]);
+  }
+#endif
+  return pWInfo->eOnePass;
+}
+
+/*
+** Move the content of pSrc into pDest
+*/
+static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
+  pDest->n = pSrc->n;
+  memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
+}
+
+/*
+** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
+**
+** The new entry might overwrite an existing entry, or it might be
+** appended, or it might be discarded.  Do whatever is the right thing
+** so that pSet keeps the N_OR_COST best entries seen so far.
+*/
+static int whereOrInsert(
+  WhereOrSet *pSet,      /* The WhereOrSet to be updated */
+  Bitmask prereq,        /* Prerequisites of the new entry */
+  LogEst rRun,           /* Run-cost of the new entry */
+  LogEst nOut            /* Number of outputs for the new entry */
+){
+  u16 i;
+  WhereOrCost *p;
+  for(i=pSet->n, p=pSet->a; i>0; i--, p++){
+    if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
+      goto whereOrInsert_done;
+    }
+    if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
+      return 0;
+    }
+  }
+  if( pSet->n<N_OR_COST ){
+    p = &pSet->a[pSet->n++];
+    p->nOut = nOut;
+  }else{
+    p = pSet->a;
+    for(i=1; i<pSet->n; i++){
+      if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
+    }
+    if( p->rRun<=rRun ) return 0;
+  }
+whereOrInsert_done:
+  p->prereq = prereq;
+  p->rRun = rRun;
+  if( p->nOut>nOut ) p->nOut = nOut;
+  return 1;
+}
+
+/*
+** Return the bitmask for the given cursor number.  Return 0 if
+** iCursor is not in the set.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
+  int i;
+  assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
+  for(i=0; i<pMaskSet->n; i++){
+    if( pMaskSet->ix[i]==iCursor ){
+      return MASKBIT(i);
     }
   }
   return 0;
 }
 
 /*
-** This function searches the expression list passed as the second argument
-** for an expression of type TK_COLUMN that refers to the same column and
-** uses the same collation sequence as the iCol'th column of index pIdx.
-** Argument iBase is the cursor number used for the table that pIdx refers
-** to.
+** Create a new mask for cursor iCursor.
+**
+** There is one cursor per table in the FROM clause.  The number of
+** tables in the FROM clause is limited by a test early in the
+** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
+** array will never overflow.
+*/
+static void createMask(WhereMaskSet *pMaskSet, int iCursor){
+  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
+  pMaskSet->ix[pMaskSet->n++] = iCursor;
+}
+
+/*
+** Advance to the next WhereTerm that matches according to the criteria
+** established when the pScan object was initialized by whereScanInit().
+** Return NULL if there are no more matching WhereTerms.
+*/
+static WhereTerm *whereScanNext(WhereScan *pScan){
+  int iCur;            /* The cursor on the LHS of the term */
+  i16 iColumn;         /* The column on the LHS of the term.  -1 for IPK */
+  Expr *pX;            /* An expression being tested */
+  WhereClause *pWC;    /* Shorthand for pScan->pWC */
+  WhereTerm *pTerm;    /* The term being tested */
+  int k = pScan->k;    /* Where to start scanning */
+
+  while( pScan->iEquiv<=pScan->nEquiv ){
+    iCur = pScan->aiCur[pScan->iEquiv-1];
+    iColumn = pScan->aiColumn[pScan->iEquiv-1];
+    if( iColumn==XN_EXPR && pScan->pIdxExpr==0 ) return 0;
+    while( (pWC = pScan->pWC)!=0 ){
+      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
+        if( pTerm->leftCursor==iCur
+         && pTerm->u.leftColumn==iColumn
+         && (iColumn!=XN_EXPR
+             || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
+         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+        ){
+          if( (pTerm->eOperator & WO_EQUIV)!=0
+           && pScan->nEquiv<ArraySize(pScan->aiCur)
+           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
+          ){
+            int j;
+            for(j=0; j<pScan->nEquiv; j++){
+              if( pScan->aiCur[j]==pX->iTable
+               && pScan->aiColumn[j]==pX->iColumn ){
+                  break;
+              }
+            }
+            if( j==pScan->nEquiv ){
+              pScan->aiCur[j] = pX->iTable;
+              pScan->aiColumn[j] = pX->iColumn;
+              pScan->nEquiv++;
+            }
+          }
+          if( (pTerm->eOperator & pScan->opMask)!=0 ){
+            /* Verify the affinity and collating sequence match */
+            if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
+              CollSeq *pColl;
+              Parse *pParse = pWC->pWInfo->pParse;
+              pX = pTerm->pExpr;
+              if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
+                continue;
+              }
+              assert(pX->pLeft);
+              pColl = sqlite3BinaryCompareCollSeq(pParse,
+                                                  pX->pLeft, pX->pRight);
+              if( pColl==0 ) pColl = pParse->db->pDfltColl;
+              if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
+                continue;
+              }
+            }
+            if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
+             && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
+             && pX->iTable==pScan->aiCur[0]
+             && pX->iColumn==pScan->aiColumn[0]
+            ){
+              testcase( pTerm->eOperator & WO_IS );
+              continue;
+            }
+            pScan->k = k+1;
+            return pTerm;
+          }
+        }
+      }
+      pScan->pWC = pScan->pWC->pOuter;
+      k = 0;
+    }
+    pScan->pWC = pScan->pOrigWC;
+    k = 0;
+    pScan->iEquiv++;
+  }
+  return 0;
+}
+
+/*
+** Initialize a WHERE clause scanner object.  Return a pointer to the
+** first match.  Return NULL if there are no matches.
+**
+** The scanner will be searching the WHERE clause pWC.  It will look
+** for terms of the form "X <op> <expr>" where X is column iColumn of table
+** iCur.   Or if pIdx!=0 then X is column iColumn of index pIdx.  pIdx
+** must be one of the indexes of table iCur.
+**
+** The <op> must be one of the operators described by opMask.
+**
+** If the search is for X and the WHERE clause contains terms of the
+** form X=Y then this routine might also return terms of the form
+** "Y <op> <expr>".  The number of levels of transitivity is limited,
+** but is enough to handle most commonly occurring SQL statements.
+**
+** If X is not the INTEGER PRIMARY KEY then X must be compatible with
+** index pIdx.
+*/
+static WhereTerm *whereScanInit(
+  WhereScan *pScan,       /* The WhereScan object being initialized */
+  WhereClause *pWC,       /* The WHERE clause to be scanned */
+  int iCur,               /* Cursor to scan for */
+  int iColumn,            /* Column to scan for */
+  u32 opMask,             /* Operator(s) to scan for */
+  Index *pIdx             /* Must be compatible with this index */
+){
+  int j = 0;
+
+  /* memset(pScan, 0, sizeof(*pScan)); */
+  pScan->pOrigWC = pWC;
+  pScan->pWC = pWC;
+  pScan->pIdxExpr = 0;
+  if( pIdx ){
+    j = iColumn;
+    iColumn = pIdx->aiColumn[j];
+    if( iColumn==XN_EXPR ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
+    if( iColumn==pIdx->pTable->iPKey ) iColumn = XN_ROWID;
+  }
+  if( pIdx && iColumn>=0 ){
+    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
+    pScan->zCollName = pIdx->azColl[j];
+  }else{
+    pScan->idxaff = 0;
+    pScan->zCollName = 0;
+  }
+  pScan->opMask = opMask;
+  pScan->k = 0;
+  pScan->aiCur[0] = iCur;
+  pScan->aiColumn[0] = iColumn;
+  pScan->nEquiv = 1;
+  pScan->iEquiv = 1;
+  return whereScanNext(pScan);
+}
+
+/*
+** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
+** where X is a reference to the iColumn of table iCur or of index pIdx
+** if pIdx!=0 and <op> is one of the WO_xx operator codes specified by
+** the op parameter.  Return a pointer to the term.  Return 0 if not found.
+**
+** If pIdx!=0 then it must be one of the indexes of table iCur.  
+** Search for terms matching the iColumn-th column of pIdx
+** rather than the iColumn-th column of table iCur.
+**
+** The term returned might by Y=<expr> if there is another constraint in
+** the WHERE clause that specifies that X=Y.  Any such constraints will be
+** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
+** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
+** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
+** other equivalent values.  Hence a search for X will return <expr> if X=A1
+** and A1=A2 and A2=A3 and ... and A9=A10 and A10=<expr>.
+**
+** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
+** then try for the one with no dependencies on <expr> - in other words where
+** <expr> is a constant expression of some kind.  Only return entries of
+** the form "X <op> Y" where Y is a column in another table if no terms of
+** the form "X <op> <const-expr>" exist.   If no terms with a constant RHS
+** exist, try to return a term that does not use WO_EQUIV.
+*/
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+){
+  WhereTerm *pResult = 0;
+  WhereTerm *p;
+  WhereScan scan;
+
+  p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
+  op &= WO_EQ|WO_IS;
+  while( p ){
+    if( (p->prereqRight & notReady)==0 ){
+      if( p->prereqRight==0 && (p->eOperator&op)!=0 ){
+        testcase( p->eOperator & WO_IS );
+        return p;
+      }
+      if( pResult==0 ) pResult = p;
+    }
+    p = whereScanNext(&scan);
+  }
+  return pResult;
+}
+
+/*
+** This function searches pList for an entry that matches the iCol-th column
+** of index pIdx.
 **
 ** If such an expression is found, its index in pList->a[] is returned. If
 ** no expression is found, -1 is returned.
@@ -102141,13 +127098,13 @@ static int findIndexCol(
   const char *zColl = pIdx->azColl[iCol];
 
   for(i=0; i<pList->nExpr; i++){
-    Expr *p = pList->a[i].pExpr;
+    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
     if( p->op==TK_COLUMN
      && p->iColumn==pIdx->aiColumn[iCol]
      && p->iTable==iBase
     ){
-      CollSeq *pColl = sqlite3ExprCollSeq(pParse, p);
-      if( ALWAYS(pColl) && 0==sqlite3StrICmp(pColl->zName, zColl) ){
+      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
+      if( pColl && 0==sqlite3StrICmp(pColl->zName, zColl) ){
         return i;
       }
     }
@@ -102157,75 +127114,36 @@ static int findIndexCol(
 }
 
 /*
-** This routine determines if pIdx can be used to assist in processing a
-** DISTINCT qualifier. In other words, it tests whether or not using this
-** index for the outer loop guarantees that rows with equal values for
-** all expressions in the pDistinct list are delivered grouped together.
-**
-** For example, the query 
-**
-**   SELECT DISTINCT a, b, c FROM tbl WHERE a = ?
-**
-** can benefit from any index on columns "b" and "c".
+** Return TRUE if the iCol-th column of index pIdx is NOT NULL
 */
-static int isDistinctIndex(
-  Parse *pParse,                  /* Parsing context */
-  WhereClause *pWC,               /* The WHERE clause */
-  Index *pIdx,                    /* The index being considered */
-  int base,                       /* Cursor number for the table pIdx is on */
-  ExprList *pDistinct,            /* The DISTINCT expressions */
-  int nEqCol                      /* Number of index columns with == */
-){
-  Bitmask mask = 0;               /* Mask of unaccounted for pDistinct exprs */
-  int i;                          /* Iterator variable */
-
-  if( pIdx->zName==0 || pDistinct==0 || pDistinct->nExpr>=BMS ) return 0;
-  testcase( pDistinct->nExpr==BMS-1 );
-
-  /* Loop through all the expressions in the distinct list. If any of them
-  ** are not simple column references, return early. Otherwise, test if the
-  ** WHERE clause contains a "col=X" clause. If it does, the expression
-  ** can be ignored. If it does not, and the column does not belong to the
-  ** same table as index pIdx, return early. Finally, if there is no
-  ** matching "col=X" expression and the column is on the same table as pIdx,
-  ** set the corresponding bit in variable mask.
-  */
-  for(i=0; i<pDistinct->nExpr; i++){
-    WhereTerm *pTerm;
-    Expr *p = pDistinct->a[i].pExpr;
-    if( p->op!=TK_COLUMN ) return 0;
-    pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0);
-    if( pTerm ){
-      Expr *pX = pTerm->pExpr;
-      CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-      CollSeq *p2 = sqlite3ExprCollSeq(pParse, p);
-      if( p1==p2 ) continue;
-    }
-    if( p->iTable!=base ) return 0;
-    mask |= (((Bitmask)1) << i);
-  }
+static int indexColumnNotNull(Index *pIdx, int iCol){
+  int j;
+  assert( pIdx!=0 );
+  assert( iCol>=0 && iCol<pIdx->nColumn );
+  j = pIdx->aiColumn[iCol];
+  if( j>=0 ){
+    return pIdx->pTable->aCol[j].notNull;
+  }else if( j==(-1) ){
+    return 1;
+  }else{
+    assert( j==(-2) );
+    return 0;  /* Assume an indexed expression can always yield a NULL */
 
-  for(i=nEqCol; mask && i<pIdx->nColumn; i++){
-    int iExpr = findIndexCol(pParse, pDistinct, base, pIdx, i);
-    if( iExpr<0 ) break;
-    mask &= ~(((Bitmask)1) << iExpr);
   }
-
-  return (mask==0);
 }
 
-
 /*
 ** Return true if the DISTINCT expression-list passed as the third argument
-** is redundant. A DISTINCT list is redundant if the database contains a
-** UNIQUE index that guarantees that the result of the query will be distinct
-** anyway.
+** is redundant.
+**
+** A DISTINCT list is redundant if any subset of the columns in the
+** DISTINCT list are collectively unique and individually non-null.
 */
 static int isDistinctRedundant(
-  Parse *pParse,
-  SrcList *pTabList,
-  WhereClause *pWC,
-  ExprList *pDistinct
+  Parse *pParse,            /* Parsing context */
+  SrcList *pTabList,        /* The FROM clause */
+  WhereClause *pWC,         /* The WHERE clause */
+  ExprList *pDistinct       /* The result set that needs to be DISTINCT */
 ){
   Table *pTab;
   Index *pIdx;
@@ -102244,7 +127162,7 @@ static int isDistinctRedundant(
   ** current SELECT is a correlated sub-query.
   */
   for(i=0; i<pDistinct->nExpr; i++){
-    Expr *p = pDistinct->a[i].pExpr;
+    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
     if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
   }
 
@@ -102257,18 +127175,19 @@ static int isDistinctRedundant(
   **      list, or else the WHERE clause contains a term of the form "col=X",
   **      where X is a constant value. The collation sequences of the
   **      comparison and select-list expressions must match those of the index.
+  **
+  **   3. All of those index columns for which the WHERE clause does not
+  **      contain a "col=X" term are subject to a NOT NULL constraint.
   */
   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-    if( pIdx->onError==OE_None ) continue;
-    for(i=0; i<pIdx->nColumn; i++){
-      int iCol = pIdx->aiColumn[i];
-      if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) 
-       && 0>findIndexCol(pParse, pDistinct, iBase, pIdx, i)
-      ){
-        break;
+    if( !IsUniqueIndex(pIdx) ) continue;
+    for(i=0; i<pIdx->nKeyCol; i++){
+      if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){
+        if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;
+        if( indexColumnNotNull(pIdx, i)==0 ) break;
       }
     }
-    if( i==pIdx->nColumn ){
+    if( i==pIdx->nKeyCol ){
       /* This index implies that the DISTINCT qualifier is redundant. */
       return 1;
     }
@@ -102277,169 +127196,55 @@ static int isDistinctRedundant(
   return 0;
 }
 
+
 /*
-** This routine decides if pIdx can be used to satisfy the ORDER BY
-** clause.  If it can, it returns 1.  If pIdx cannot satisfy the
-** ORDER BY clause, this routine returns 0.
-**
-** pOrderBy is an ORDER BY clause from a SELECT statement.  pTab is the
-** left-most table in the FROM clause of that same SELECT statement and
-** the table has a cursor number of "base".  pIdx is an index on pTab.
+** Estimate the logarithm of the input value to base 2.
+*/
+static LogEst estLog(LogEst N){
+  return N<=10 ? 0 : sqlite3LogEst(N) - 33;
+}
+
+/*
+** Convert OP_Column opcodes to OP_Copy in previously generated code.
 **
-** nEqCol is the number of columns of pIdx that are used as equality
-** constraints.  Any of these columns may be missing from the ORDER BY
-** clause and the match can still be a success.
+** This routine runs over generated VDBE code and translates OP_Column
+** opcodes into OP_Copy when the table is being accessed via co-routine 
+** instead of via table lookup.
 **
-** All terms of the ORDER BY that match against the index must be either
-** ASC or DESC.  (Terms of the ORDER BY clause past the end of a UNIQUE
-** index do not need to satisfy this constraint.)  The *pbRev value is
-** set to 1 if the ORDER BY clause is all DESC and it is set to 0 if
-** the ORDER BY clause is all ASC.
+** If the bIncrRowid parameter is 0, then any OP_Rowid instructions on
+** cursor iTabCur are transformed into OP_Null. Or, if bIncrRowid is non-zero,
+** then each OP_Rowid is transformed into an instruction to increment the
+** value stored in its output register.
 */
-static int isSortingIndex(
-  Parse *pParse,          /* Parsing context */
-  WhereMaskSet *pMaskSet, /* Mapping from table cursor numbers to bitmaps */
-  Index *pIdx,            /* The index we are testing */
-  int base,               /* Cursor number for the table to be sorted */
-  ExprList *pOrderBy,     /* The ORDER BY clause */
-  int nEqCol,             /* Number of index columns with == constraints */
-  int wsFlags,            /* Index usages flags */
-  int *pbRev              /* Set to 1 if ORDER BY is DESC */
+static void translateColumnToCopy(
+  Vdbe *v,            /* The VDBE containing code to translate */
+  int iStart,         /* Translate from this opcode to the end */
+  int iTabCur,        /* OP_Column/OP_Rowid references to this table */
+  int iRegister,      /* The first column is in this register */
+  int bIncrRowid      /* If non-zero, transform OP_rowid to OP_AddImm(1) */
 ){
-  int i, j;                       /* Loop counters */
-  int sortOrder = 0;              /* XOR of index and ORDER BY sort direction */
-  int nTerm;                      /* Number of ORDER BY terms */
-  struct ExprList_item *pTerm;    /* A term of the ORDER BY clause */
-  sqlite3 *db = pParse->db;
-
-  if( !pOrderBy ) return 0;
-  if( wsFlags & WHERE_COLUMN_IN ) return 0;
-  if( pIdx->bUnordered ) return 0;
-
-  nTerm = pOrderBy->nExpr;
-  assert( nTerm>0 );
-
-  /* Argument pIdx must either point to a 'real' named index structure, 
-  ** or an index structure allocated on the stack by bestBtreeIndex() to
-  ** represent the rowid index that is part of every table.  */
-  assert( pIdx->zName || (pIdx->nColumn==1 && pIdx->aiColumn[0]==-1) );
-
-  /* Match terms of the ORDER BY clause against columns of
-  ** the index.
-  **
-  ** Note that indices have pIdx->nColumn regular columns plus
-  ** one additional column containing the rowid.  The rowid column
-  ** of the index is also allowed to match against the ORDER BY
-  ** clause.
-  */
-  for(i=j=0, pTerm=pOrderBy->a; j<nTerm && i<=pIdx->nColumn; i++){
-    Expr *pExpr;       /* The expression of the ORDER BY pTerm */
-    CollSeq *pColl;    /* The collating sequence of pExpr */
-    int termSortOrder; /* Sort order for this term */
-    int iColumn;       /* The i-th column of the index.  -1 for rowid */
-    int iSortOrder;    /* 1 for DESC, 0 for ASC on the i-th index term */
-    const char *zColl; /* Name of the collating sequence for i-th index term */
-
-    pExpr = pTerm->pExpr;
-    if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
-      /* Can not use an index sort on anything that is not a column in the
-      ** left-most table of the FROM clause */
-      break;
-    }
-    pColl = sqlite3ExprCollSeq(pParse, pExpr);
-    if( !pColl ){
-      pColl = db->pDfltColl;
-    }
-    if( pIdx->zName && i<pIdx->nColumn ){
-      iColumn = pIdx->aiColumn[i];
-      if( iColumn==pIdx->pTable->iPKey ){
-        iColumn = -1;
-      }
-      iSortOrder = pIdx->aSortOrder[i];
-      zColl = pIdx->azColl[i];
-    }else{
-      iColumn = -1;
-      iSortOrder = 0;
-      zColl = pColl->zName;
-    }
-    if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
-      /* Term j of the ORDER BY clause does not match column i of the index */
-      if( i<nEqCol ){
-        /* If an index column that is constrained by == fails to match an
-        ** ORDER BY term, that is OK.  Just ignore that column of the index
-        */
-        continue;
-      }else if( i==pIdx->nColumn ){
-        /* Index column i is the rowid.  All other terms match. */
-        break;
+  VdbeOp *pOp = sqlite3VdbeGetOp(v, iStart);
+  int iEnd = sqlite3VdbeCurrentAddr(v);
+  for(; iStart<iEnd; iStart++, pOp++){
+    if( pOp->p1!=iTabCur ) continue;
+    if( pOp->opcode==OP_Column ){
+      pOp->opcode = OP_Copy;
+      pOp->p1 = pOp->p2 + iRegister;
+      pOp->p2 = pOp->p3;
+      pOp->p3 = 0;
+    }else if( pOp->opcode==OP_Rowid ){
+      if( bIncrRowid ){
+        /* Increment the value stored in the P2 operand of the OP_Rowid. */
+        pOp->opcode = OP_AddImm;
+        pOp->p1 = pOp->p2;
+        pOp->p2 = 1;
       }else{
-        /* If an index column fails to match and is not constrained by ==
-        ** then the index cannot satisfy the ORDER BY constraint.
-        */
-        return 0;
+        pOp->opcode = OP_Null;
+        pOp->p1 = 0;
+        pOp->p3 = 0;
       }
     }
-    assert( pIdx->aSortOrder!=0 || iColumn==-1 );
-    assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
-    assert( iSortOrder==0 || iSortOrder==1 );
-    termSortOrder = iSortOrder ^ pTerm->sortOrder;
-    if( i>nEqCol ){
-      if( termSortOrder!=sortOrder ){
-        /* Indices can only be used if all ORDER BY terms past the
-        ** equality constraints are all either DESC or ASC. */
-        return 0;
-      }
-    }else{
-      sortOrder = termSortOrder;
-    }
-    j++;
-    pTerm++;
-    if( iColumn<0 && !referencesOtherTables(pOrderBy, pMaskSet, j, base) ){
-      /* If the indexed column is the primary key and everything matches
-      ** so far and none of the ORDER BY terms to the right reference other
-      ** tables in the join, then we are assured that the index can be used 
-      ** to sort because the primary key is unique and so none of the other
-      ** columns will make any difference
-      */
-      j = nTerm;
-    }
-  }
-
-  *pbRev = sortOrder!=0;
-  if( j>=nTerm ){
-    /* All terms of the ORDER BY clause are covered by this index so
-    ** this index can be used for sorting. */
-    return 1;
   }
-  if( pIdx->onError!=OE_None && i==pIdx->nColumn
-      && (wsFlags & WHERE_COLUMN_NULL)==0
-      && !referencesOtherTables(pOrderBy, pMaskSet, j, base) ){
-    /* All terms of this index match some prefix of the ORDER BY clause
-    ** and the index is UNIQUE and no terms on the tail of the ORDER BY
-    ** clause reference other tables in a join.  If this is all true then
-    ** the order by clause is superfluous.  Not that if the matching
-    ** condition is IS NULL then the result is not necessarily unique
-    ** even on a UNIQUE index, so disallow those cases. */
-    return 1;
-  }
-  return 0;
-}
-
-/*
-** Prepare a crude estimate of the logarithm of the input value.
-** The results need not be exact.  This is only used for estimating
-** the total cost of performing operations with O(logN) or O(NlogN)
-** complexity.  Because N is just a guess, it is no great tragedy if
-** logN is a little off.
-*/
-static double estLog(double N){
-  double logN = 1;
-  double x = 10;
-  while( N>x ){
-    logN += 1;
-    x *= 10;
-  }
-  return logN;
 }
 
 /*
@@ -102448,7 +127253,7 @@ static double estLog(double N){
 ** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
 ** are no-ops.
 */
-#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_DEBUG)
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
 static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
   int i;
   if( !sqlite3WhereTrace ) return;
@@ -102480,115 +127285,13 @@ static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
   sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);
   sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);
   sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);
+  sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);
 }
 #else
 #define TRACE_IDX_INPUTS(A)
 #define TRACE_IDX_OUTPUTS(A)
 #endif
 
-/* 
-** Required because bestIndex() is called by bestOrClauseIndex() 
-*/
-static void bestIndex(
-    Parse*, WhereClause*, struct SrcList_item*,
-    Bitmask, Bitmask, ExprList*, WhereCost*);
-
-/*
-** This routine attempts to find an scanning strategy that can be used 
-** to optimize an 'OR' expression that is part of a WHERE clause. 
-**
-** The table associated with FROM clause term pSrc may be either a
-** regular B-Tree table or a virtual table.
-*/
-static void bestOrClauseIndex(
-  Parse *pParse,              /* The parsing context */
-  WhereClause *pWC,           /* The WHERE clause */
-  struct SrcList_item *pSrc,  /* The FROM clause term to search */
-  Bitmask notReady,           /* Mask of cursors not available for indexing */
-  Bitmask notValid,           /* Cursors not available for any purpose */
-  ExprList *pOrderBy,         /* The ORDER BY clause */
-  WhereCost *pCost            /* Lowest cost query plan */
-){
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
-  const int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
-  const Bitmask maskSrc = getMask(pWC->pMaskSet, iCur);  /* Bitmask for pSrc */
-  WhereTerm * const pWCEnd = &pWC->a[pWC->nTerm];        /* End of pWC->a[] */
-  WhereTerm *pTerm;                 /* A single term of the WHERE clause */
-
-  /* The OR-clause optimization is disallowed if the INDEXED BY or
-  ** NOT INDEXED clauses are used or if the WHERE_AND_ONLY bit is set. */
-  if( pSrc->notIndexed || pSrc->pIndex!=0 ){
-    return;
-  }
-  if( pWC->wctrlFlags & WHERE_AND_ONLY ){
-    return;
-  }
-
-  /* Search the WHERE clause terms for a usable WO_OR term. */
-  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
-    if( pTerm->eOperator==WO_OR 
-     && ((pTerm->prereqAll & ~maskSrc) & notReady)==0
-     && (pTerm->u.pOrInfo->indexable & maskSrc)!=0 
-    ){
-      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
-      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
-      WhereTerm *pOrTerm;
-      int flags = WHERE_MULTI_OR;
-      double rTotal = 0;
-      double nRow = 0;
-      Bitmask used = 0;
-
-      for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
-        WhereCost sTermCost;
-        WHERETRACE(("... Multi-index OR testing for term %d of %d....\n", 
-          (pOrTerm - pOrWC->a), (pTerm - pWC->a)
-        ));
-        if( pOrTerm->eOperator==WO_AND ){
-          WhereClause *pAndWC = &pOrTerm->u.pAndInfo->wc;
-          bestIndex(pParse, pAndWC, pSrc, notReady, notValid, 0, &sTermCost);
-        }else if( pOrTerm->leftCursor==iCur ){
-          WhereClause tempWC;
-          tempWC.pParse = pWC->pParse;
-          tempWC.pMaskSet = pWC->pMaskSet;
-          tempWC.pOuter = pWC;
-          tempWC.op = TK_AND;
-          tempWC.a = pOrTerm;
-          tempWC.wctrlFlags = 0;
-          tempWC.nTerm = 1;
-          bestIndex(pParse, &tempWC, pSrc, notReady, notValid, 0, &sTermCost);
-        }else{
-          continue;
-        }
-        rTotal += sTermCost.rCost;
-        nRow += sTermCost.plan.nRow;
-        used |= sTermCost.used;
-        if( rTotal>=pCost->rCost ) break;
-      }
-
-      /* If there is an ORDER BY clause, increase the scan cost to account 
-      ** for the cost of the sort. */
-      if( pOrderBy!=0 ){
-        WHERETRACE(("... sorting increases OR cost %.9g to %.9g\n",
-                    rTotal, rTotal+nRow*estLog(nRow)));
-        rTotal += nRow*estLog(nRow);
-      }
-
-      /* If the cost of scanning using this OR term for optimization is
-      ** less than the current cost stored in pCost, replace the contents
-      ** of pCost. */
-      WHERETRACE(("... multi-index OR cost=%.9g nrow=%.9g\n", rTotal, nRow));
-      if( rTotal<pCost->rCost ){
-        pCost->rCost = rTotal;
-        pCost->used = used;
-        pCost->plan.nRow = nRow;
-        pCost->plan.wsFlags = flags;
-        pCost->plan.u.pTerm = pTerm;
-      }
-    }
-  }
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
-}
-
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
 ** Return TRUE if the WHERE clause term pTerm is of a form where it
@@ -102602,87 +127305,16 @@ static int termCanDriveIndex(
 ){
   char aff;
   if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
-  if( pTerm->eOperator!=WO_EQ ) return 0;
+  if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;
   if( (pTerm->prereqRight & notReady)!=0 ) return 0;
+  if( pTerm->u.leftColumn<0 ) return 0;
   aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
   if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
+  testcase( pTerm->pExpr->op==TK_IS );
   return 1;
 }
 #endif
 
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-/*
-** If the query plan for pSrc specified in pCost is a full table scan
-** and indexing is allows (if there is no NOT INDEXED clause) and it
-** possible to construct a transient index that would perform better
-** than a full table scan even when the cost of constructing the index
-** is taken into account, then alter the query plan to use the
-** transient index.
-*/
-static void bestAutomaticIndex(
-  Parse *pParse,              /* The parsing context */
-  WhereClause *pWC,           /* The WHERE clause */
-  struct SrcList_item *pSrc,  /* The FROM clause term to search */
-  Bitmask notReady,           /* Mask of cursors that are not available */
-  WhereCost *pCost            /* Lowest cost query plan */
-){
-  double nTableRow;           /* Rows in the input table */
-  double logN;                /* log(nTableRow) */
-  double costTempIdx;         /* per-query cost of the transient index */
-  WhereTerm *pTerm;           /* A single term of the WHERE clause */
-  WhereTerm *pWCEnd;          /* End of pWC->a[] */
-  Table *pTable;              /* Table tht might be indexed */
-
-  if( pParse->nQueryLoop<=(double)1 ){
-    /* There is no point in building an automatic index for a single scan */
-    return;
-  }
-  if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
-    /* Automatic indices are disabled at run-time */
-    return;
-  }
-  if( (pCost->plan.wsFlags & WHERE_NOT_FULLSCAN)!=0 ){
-    /* We already have some kind of index in use for this query. */
-    return;
-  }
-  if( pSrc->notIndexed ){
-    /* The NOT INDEXED clause appears in the SQL. */
-    return;
-  }
-  if( pSrc->isCorrelated ){
-    /* The source is a correlated sub-query. No point in indexing it. */
-    return;
-  }
-
-  assert( pParse->nQueryLoop >= (double)1 );
-  pTable = pSrc->pTab;
-  nTableRow = pTable->nRowEst;
-  logN = estLog(nTableRow);
-  costTempIdx = 2*logN*(nTableRow/pParse->nQueryLoop + 1);
-  if( costTempIdx>=pCost->rCost ){
-    /* The cost of creating the transient table would be greater than
-    ** doing the full table scan */
-    return;
-  }
-
-  /* Search for any equality comparison term */
-  pWCEnd = &pWC->a[pWC->nTerm];
-  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
-    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
-      WHERETRACE(("auto-index reduces cost from %.1f to %.1f\n",
-                    pCost->rCost, costTempIdx));
-      pCost->rCost = costTempIdx;
-      pCost->plan.nRow = logN + 1;
-      pCost->plan.wsFlags = WHERE_TEMP_INDEX;
-      pCost->used = pTerm->prereqRight;
-      break;
-    }
-  }
-}
-#else
-# define bestAutomaticIndex(A,B,C,D,E)  /* no-op */
-#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
-
 
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
@@ -102697,52 +127329,79 @@ static void constructAutomaticIndex(
   Bitmask notReady,           /* Mask of cursors that are not available */
   WhereLevel *pLevel          /* Write new index here */
 ){
-  int nColumn;                /* Number of columns in the constructed index */
+  int nKeyCol;                /* Number of columns in the constructed index */
   WhereTerm *pTerm;           /* A single term of the WHERE clause */
   WhereTerm *pWCEnd;          /* End of pWC->a[] */
-  int nByte;                  /* Byte of memory needed for pIdx */
   Index *pIdx;                /* Object describing the transient index */
   Vdbe *v;                    /* Prepared statement under construction */
-  int regIsInit;              /* Register set by initialization */
   int addrInit;               /* Address of the initialization bypass jump */
   Table *pTable;              /* The table being indexed */
-  KeyInfo *pKeyinfo;          /* Key information for the index */   
   int addrTop;                /* Top of the index fill loop */
   int regRecord;              /* Register holding an index record */
   int n;                      /* Column counter */
   int i;                      /* Loop counter */
   int mxBitCol;               /* Maximum column in pSrc->colUsed */
   CollSeq *pColl;             /* Collating sequence to on a column */
+  WhereLoop *pLoop;           /* The Loop object */
+  char *zNotUsed;             /* Extra space on the end of pIdx */
   Bitmask idxCols;            /* Bitmap of columns used for indexing */
   Bitmask extraCols;          /* Bitmap of additional columns */
+  u8 sentWarning = 0;         /* True if a warnning has been issued */
+  Expr *pPartial = 0;         /* Partial Index Expression */
+  int iContinue = 0;          /* Jump here to skip excluded rows */
+  struct SrcList_item *pTabItem;  /* FROM clause term being indexed */
+  int addrCounter = 0;        /* Address where integer counter is initialized */
+  int regBase;                /* Array of registers where record is assembled */
 
   /* Generate code to skip over the creation and initialization of the
   ** transient index on 2nd and subsequent iterations of the loop. */
   v = pParse->pVdbe;
   assert( v!=0 );
-  regIsInit = ++pParse->nMem;
-  addrInit = sqlite3VdbeAddOp1(v, OP_Once, regIsInit);
+  addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v);
 
   /* Count the number of columns that will be added to the index
   ** and used to match WHERE clause constraints */
-  nColumn = 0;
+  nKeyCol = 0;
   pTable = pSrc->pTab;
   pWCEnd = &pWC->a[pWC->nTerm];
+  pLoop = pLevel->pWLoop;
   idxCols = 0;
   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
+    Expr *pExpr = pTerm->pExpr;
+    assert( !ExprHasProperty(pExpr, EP_FromJoin)    /* prereq always non-zero */
+         || pExpr->iRightJoinTable!=pSrc->iCursor   /*   for the right-hand   */
+         || pLoop->prereq!=0 );                     /*   table of a LEFT JOIN */
+    if( pLoop->prereq==0
+     && (pTerm->wtFlags & TERM_VIRTUAL)==0
+     && !ExprHasProperty(pExpr, EP_FromJoin)
+     && sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){
+      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
+                                sqlite3ExprDup(pParse->db, pExpr, 0));
+    }
     if( termCanDriveIndex(pTerm, pSrc, notReady) ){
       int iCol = pTerm->u.leftColumn;
-      Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
       testcase( iCol==BMS );
       testcase( iCol==BMS-1 );
+      if( !sentWarning ){
+        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
+            "automatic index on %s(%s)", pTable->zName,
+            pTable->aCol[iCol].zName);
+        sentWarning = 1;
+      }
       if( (idxCols & cMask)==0 ){
-        nColumn++;
+        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
+          goto end_auto_index_create;
+        }
+        pLoop->aLTerm[nKeyCol++] = pTerm;
         idxCols |= cMask;
       }
     }
   }
-  assert( nColumn>0 );
-  pLevel->plan.nEq = nColumn;
+  assert( nKeyCol>0 );
+  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
+  pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
+                     | WHERE_AUTO_INDEX;
 
   /* Count the number of additional columns needed to create a
   ** covering index.  A "covering index" is an index that contains all
@@ -102752,88 +127411,113 @@ static void constructAutomaticIndex(
   ** original table changes and the index and table cannot both be used
   ** if they go out of sync.
   */
-  extraCols = pSrc->colUsed & (~idxCols | (((Bitmask)1)<<(BMS-1)));
-  mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol;
+  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
+  mxBitCol = MIN(BMS-1,pTable->nCol);
   testcase( pTable->nCol==BMS-1 );
   testcase( pTable->nCol==BMS-2 );
   for(i=0; i<mxBitCol; i++){
-    if( extraCols & (((Bitmask)1)<<i) ) nColumn++;
+    if( extraCols & MASKBIT(i) ) nKeyCol++;
   }
-  if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
-    nColumn += pTable->nCol - BMS + 1;
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
+    nKeyCol += pTable->nCol - BMS + 1;
   }
-  pLevel->plan.wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WO_EQ;
 
   /* Construct the Index object to describe this index */
-  nByte = sizeof(Index);
-  nByte += nColumn*sizeof(int);     /* Index.aiColumn */
-  nByte += nColumn*sizeof(char*);   /* Index.azColl */
-  nByte += nColumn;                 /* Index.aSortOrder */
-  pIdx = sqlite3DbMallocZero(pParse->db, nByte);
-  if( pIdx==0 ) return;
-  pLevel->plan.u.pIdx = pIdx;
-  pIdx->azColl = (char**)&pIdx[1];
-  pIdx->aiColumn = (int*)&pIdx->azColl[nColumn];
-  pIdx->aSortOrder = (u8*)&pIdx->aiColumn[nColumn];
+  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
+  if( pIdx==0 ) goto end_auto_index_create;
+  pLoop->u.btree.pIndex = pIdx;
   pIdx->zName = "auto-index";
-  pIdx->nColumn = nColumn;
   pIdx->pTable = pTable;
   n = 0;
   idxCols = 0;
   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
     if( termCanDriveIndex(pTerm, pSrc, notReady) ){
       int iCol = pTerm->u.leftColumn;
-      Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS-1 );
+      testcase( iCol==BMS );
       if( (idxCols & cMask)==0 ){
         Expr *pX = pTerm->pExpr;
         idxCols |= cMask;
         pIdx->aiColumn[n] = pTerm->u.leftColumn;
         pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-        pIdx->azColl[n] = ALWAYS(pColl) ? pColl->zName : "BINARY";
+        pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
         n++;
       }
     }
   }
-  assert( (u32)n==pLevel->plan.nEq );
+  assert( (u32)n==pLoop->u.btree.nEq );
 
   /* Add additional columns needed to make the automatic index into
   ** a covering index */
   for(i=0; i<mxBitCol; i++){
-    if( extraCols & (((Bitmask)1)<<i) ){
+    if( extraCols & MASKBIT(i) ){
       pIdx->aiColumn[n] = i;
-      pIdx->azColl[n] = "BINARY";
+      pIdx->azColl[n] = sqlite3StrBINARY;
       n++;
     }
   }
-  if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
     for(i=BMS-1; i<pTable->nCol; i++){
       pIdx->aiColumn[n] = i;
-      pIdx->azColl[n] = "BINARY";
+      pIdx->azColl[n] = sqlite3StrBINARY;
       n++;
     }
   }
-  assert( n==nColumn );
+  assert( n==nKeyCol );
+  pIdx->aiColumn[n] = XN_ROWID;
+  pIdx->azColl[n] = sqlite3StrBINARY;
 
   /* Create the automatic index */
-  pKeyinfo = sqlite3IndexKeyinfo(pParse, pIdx);
   assert( pLevel->iIdxCur>=0 );
-  sqlite3VdbeAddOp4(v, OP_OpenAutoindex, pLevel->iIdxCur, nColumn+1, 0,
-                    (char*)pKeyinfo, P4_KEYINFO_HANDOFF);
+  pLevel->iIdxCur = pParse->nTab++;
+  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
+  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
   VdbeComment((v, "for %s", pTable->zName));
 
   /* Fill the automatic index with content */
-  addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur);
+  sqlite3ExprCachePush(pParse);
+  pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+  }else{
+    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
+  }
+  if( pPartial ){
+    iContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
+    pLoop->wsFlags |= WHERE_PARTIALIDX;
+  }
   regRecord = sqlite3GetTempReg(pParse);
-  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 1);
+  regBase = sqlite3GenerateIndexKey(
+      pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
+  );
   sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-  sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1);
+  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
+  if( pTabItem->fg.viaCoroutine ){
+    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
+    translateColumnToCopy(v, addrTop, pLevel->iTabCur, pTabItem->regResult, 1);
+    sqlite3VdbeGoto(v, addrTop);
+    pTabItem->fg.viaCoroutine = 0;
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
+  }
   sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
   sqlite3VdbeJumpHere(v, addrTop);
   sqlite3ReleaseTempReg(pParse, regRecord);
+  sqlite3ExprCachePop(pParse);
   
   /* Jump here when skipping the initialization */
   sqlite3VdbeJumpHere(v, addrInit);
+
+end_auto_index_create:
+  sqlite3ExprDelete(pParse->db, pPartial);
 }
 #endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
 
@@ -102844,8 +127528,9 @@ static void constructAutomaticIndex(
 ** by passing the pointer returned by this function to sqlite3_free().
 */
 static sqlite3_index_info *allocateIndexInfo(
-  Parse *pParse, 
+  Parse *pParse,
   WhereClause *pWC,
+  Bitmask mUnusable,              /* Ignore terms with these prereqs */
   struct SrcList_item *pSrc,
   ExprList *pOrderBy
 ){
@@ -102858,17 +127543,19 @@ static sqlite3_index_info *allocateIndexInfo(
   int nOrderBy;
   sqlite3_index_info *pIdxInfo;
 
-  WHERETRACE(("Recomputing index info for %s...\n", pSrc->pTab->zName));
-
   /* Count the number of possible WHERE clause constraints referring
   ** to this virtual table */
   for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
     if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
-    testcase( pTerm->eOperator==WO_IN );
-    testcase( pTerm->eOperator==WO_ISNULL );
-    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
     if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
     nTerm++;
   }
 
@@ -102878,12 +127565,13 @@ static sqlite3_index_info *allocateIndexInfo(
   */
   nOrderBy = 0;
   if( pOrderBy ){
-    for(i=0; i<pOrderBy->nExpr; i++){
+    int n = pOrderBy->nExpr;
+    for(i=0; i<n; i++){
       Expr *pExpr = pOrderBy->a[i].pExpr;
       if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
     }
-    if( i==pOrderBy->nExpr ){
-      nOrderBy = pOrderBy->nExpr;
+    if( i==n){
+      nOrderBy = n;
     }
   }
 
@@ -102894,7 +127582,6 @@ static sqlite3_index_info *allocateIndexInfo(
                            + sizeof(*pIdxOrderBy)*nOrderBy );
   if( pIdxInfo==0 ){
     sqlite3ErrorMsg(pParse, "out of memory");
-    /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
     return 0;
   }
 
@@ -102914,15 +127601,25 @@ static sqlite3_index_info *allocateIndexInfo(
                                                                    pUsage;
 
   for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    u8 op;
     if( pTerm->leftCursor != pSrc->iCursor ) continue;
-    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
-    testcase( pTerm->eOperator==WO_IN );
-    testcase( pTerm->eOperator==WO_ISNULL );
-    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
     if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
     pIdxCons[j].iColumn = pTerm->u.leftColumn;
     pIdxCons[j].iTermOffset = i;
-    pIdxCons[j].op = (u8)pTerm->eOperator;
+    op = (u8)pTerm->eOperator & WO_ALL;
+    if( op==WO_IN ) op = WO_EQ;
+    if( op==WO_MATCH ){
+      op = pTerm->eMatchOp;
+    }
+    pIdxCons[j].op = op;
     /* The direct assignment in the previous line is possible only because
     ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
     ** following asserts verify this fact. */
@@ -102932,7 +127629,7 @@ static sqlite3_index_info *allocateIndexInfo(
     assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
     assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
     assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
-    assert( pTerm->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
+    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
     j++;
   }
   for(i=0; i<nOrderBy; i++){
@@ -102947,8 +127644,8 @@ static sqlite3_index_info *allocateIndexInfo(
 /*
 ** The table object reference passed as the second argument to this function
 ** must represent a virtual table. This function invokes the xBestIndex()
-** method of the virtual table with the sqlite3_index_info pointer passed
-** as the argument.
+** method of the virtual table with the sqlite3_index_info object that
+** comes in as the 3rd argument to this function.
 **
 ** If an error occurs, pParse is populated with an error message and a
 ** non-zero value is returned. Otherwise, 0 is returned and the output
@@ -102960,17 +127657,15 @@ static sqlite3_index_info *allocateIndexInfo(
 */
 static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
   sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
-  int i;
   int rc;
 
-  WHERETRACE(("xBestIndex for %s\n", pTab->zName));
   TRACE_IDX_INPUTS(p);
   rc = pVtab->pModule->xBestIndex(pVtab, p);
   TRACE_IDX_OUTPUTS(p);
 
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM ){
-      pParse->db->mallocFailed = 1;
+      sqlite3OomFault(pParse->db);
     }else if( !pVtab->zErrMsg ){
       sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
     }else{
@@ -102980,318 +127675,196 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
   sqlite3_free(pVtab->zErrMsg);
   pVtab->zErrMsg = 0;
 
+#if 0
+  /* This error is now caught by the caller.
+  ** Search for "xBestIndex malfunction" below */
   for(i=0; i<p->nConstraint; i++){
     if( !p->aConstraint[i].usable && p->aConstraintUsage[i].argvIndex>0 ){
       sqlite3ErrorMsg(pParse, 
           "table %s: xBestIndex returned an invalid plan", pTab->zName);
     }
   }
+#endif
 
   return pParse->nErr;
 }
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
 
-
-/*
-** Compute the best index for a virtual table.
-**
-** The best index is computed by the xBestIndex method of the virtual
-** table module.  This routine is really just a wrapper that sets up
-** the sqlite3_index_info structure that is used to communicate with
-** xBestIndex.
-**
-** In a join, this routine might be called multiple times for the
-** same virtual table.  The sqlite3_index_info structure is created
-** and initialized on the first invocation and reused on all subsequent
-** invocations.  The sqlite3_index_info structure is also used when
-** code is generated to access the virtual table.  The whereInfoDelete() 
-** routine takes care of freeing the sqlite3_index_info structure after
-** everybody has finished with it.
-*/
-static void bestVirtualIndex(
-  Parse *pParse,                  /* The parsing context */
-  WhereClause *pWC,               /* The WHERE clause */
-  struct SrcList_item *pSrc,      /* The FROM clause term to search */
-  Bitmask notReady,               /* Mask of cursors not available for index */
-  Bitmask notValid,               /* Cursors not valid for any purpose */
-  ExprList *pOrderBy,             /* The order by clause */
-  WhereCost *pCost,               /* Lowest cost query plan */
-  sqlite3_index_info **ppIdxInfo  /* Index information passed to xBestIndex */
-){
-  Table *pTab = pSrc->pTab;
-  sqlite3_index_info *pIdxInfo;
-  struct sqlite3_index_constraint *pIdxCons;
-  struct sqlite3_index_constraint_usage *pUsage;
-  WhereTerm *pTerm;
-  int i, j;
-  int nOrderBy;
-  double rCost;
-
-  /* Make sure wsFlags is initialized to some sane value. Otherwise, if the 
-  ** malloc in allocateIndexInfo() fails and this function returns leaving
-  ** wsFlags in an uninitialized state, the caller may behave unpredictably.
-  */
-  memset(pCost, 0, sizeof(*pCost));
-  pCost->plan.wsFlags = WHERE_VIRTUALTABLE;
-
-  /* If the sqlite3_index_info structure has not been previously
-  ** allocated and initialized, then allocate and initialize it now.
-  */
-  pIdxInfo = *ppIdxInfo;
-  if( pIdxInfo==0 ){
-    *ppIdxInfo = pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pOrderBy);
-  }
-  if( pIdxInfo==0 ){
-    return;
-  }
-
-  /* At this point, the sqlite3_index_info structure that pIdxInfo points
-  ** to will have been initialized, either during the current invocation or
-  ** during some prior invocation.  Now we just have to customize the
-  ** details of pIdxInfo for the current invocation and pass it to
-  ** xBestIndex.
-  */
-
-  /* The module name must be defined. Also, by this point there must
-  ** be a pointer to an sqlite3_vtab structure. Otherwise
-  ** sqlite3ViewGetColumnNames() would have picked up the error. 
-  */
-  assert( pTab->azModuleArg && pTab->azModuleArg[0] );
-  assert( sqlite3GetVTable(pParse->db, pTab) );
-
-  /* Set the aConstraint[].usable fields and initialize all 
-  ** output variables to zero.
-  **
-  ** aConstraint[].usable is true for constraints where the right-hand
-  ** side contains only references to tables to the left of the current
-  ** table.  In other words, if the constraint is of the form:
-  **
-  **           column = expr
-  **
-  ** and we are evaluating a join, then the constraint on column is 
-  ** only valid if all tables referenced in expr occur to the left
-  ** of the table containing column.
-  **
-  ** The aConstraints[] array contains entries for all constraints
-  ** on the current table.  That way we only have to compute it once
-  ** even though we might try to pick the best index multiple times.
-  ** For each attempt at picking an index, the order of tables in the
-  ** join might be different so we have to recompute the usable flag
-  ** each time.
-  */
-  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-  pUsage = pIdxInfo->aConstraintUsage;
-  for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
-    j = pIdxCons->iTermOffset;
-    pTerm = &pWC->a[j];
-    pIdxCons->usable = (pTerm->prereqRight&notReady) ? 0 : 1;
-  }
-  memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
-  if( pIdxInfo->needToFreeIdxStr ){
-    sqlite3_free(pIdxInfo->idxStr);
-  }
-  pIdxInfo->idxStr = 0;
-  pIdxInfo->idxNum = 0;
-  pIdxInfo->needToFreeIdxStr = 0;
-  pIdxInfo->orderByConsumed = 0;
-  /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
-  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
-  nOrderBy = pIdxInfo->nOrderBy;
-  if( !pOrderBy ){
-    pIdxInfo->nOrderBy = 0;
-  }
-
-  if( vtabBestIndex(pParse, pTab, pIdxInfo) ){
-    return;
-  }
-
-  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-  for(i=0; i<pIdxInfo->nConstraint; i++){
-    if( pUsage[i].argvIndex>0 ){
-      pCost->used |= pWC->a[pIdxCons[i].iTermOffset].prereqRight;
-    }
-  }
-
-  /* If there is an ORDER BY clause, and the selected virtual table index
-  ** does not satisfy it, increase the cost of the scan accordingly. This
-  ** matches the processing for non-virtual tables in bestBtreeIndex().
-  */
-  rCost = pIdxInfo->estimatedCost;
-  if( pOrderBy && pIdxInfo->orderByConsumed==0 ){
-    rCost += estLog(rCost)*rCost;
-  }
-
-  /* The cost is not allowed to be larger than SQLITE_BIG_DBL (the
-  ** inital value of lowestCost in this loop. If it is, then the
-  ** (cost<lowestCost) test below will never be true.
-  ** 
-  ** Use "(double)2" instead of "2.0" in case OMIT_FLOATING_POINT 
-  ** is defined.
-  */
-  if( (SQLITE_BIG_DBL/((double)2))<rCost ){
-    pCost->rCost = (SQLITE_BIG_DBL/((double)2));
-  }else{
-    pCost->rCost = rCost;
-  }
-  pCost->plan.u.pVtabIdx = pIdxInfo;
-  if( pIdxInfo->orderByConsumed ){
-    pCost->plan.wsFlags |= WHERE_ORDERBY;
-  }
-  pCost->plan.nEq = 0;
-  pIdxInfo->nOrderBy = nOrderBy;
-
-  /* Try to find a more efficient access pattern by using multiple indexes
-  ** to optimize an OR expression within the WHERE clause. 
-  */
-  bestOrClauseIndex(pParse, pWC, pSrc, notReady, notValid, pOrderBy, pCost);
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
 ** Estimate the location of a particular key among all keys in an
 ** index.  Store the results in aStat as follows:
 **
-**    aStat[0]      Est. number of rows less than pVal
-**    aStat[1]      Est. number of rows equal to pVal
+**    aStat[0]      Est. number of rows less than pRec
+**    aStat[1]      Est. number of rows equal to pRec
 **
-** Return SQLITE_OK on success.
+** Return the index of the sample that is the smallest sample that
+** is greater than or equal to pRec. Note that this index is not an index
+** into the aSample[] array - it is an index into a virtual set of samples
+** based on the contents of aSample[] and the number of fields in record 
+** pRec. 
 */
 static int whereKeyStats(
   Parse *pParse,              /* Database connection */
   Index *pIdx,                /* Index to consider domain of */
-  sqlite3_value *pVal,        /* Value to consider */
+  UnpackedRecord *pRec,       /* Vector of values to consider */
   int roundUp,                /* Round up if true.  Round down if false */
   tRowcnt *aStat              /* OUT: stats written here */
 ){
-  tRowcnt n;
-  IndexSample *aSample;
-  int i, eType;
-  int isEq = 0;
-  i64 v;
-  double r, rS;
+  IndexSample *aSample = pIdx->aSample;
+  int iCol;                   /* Index of required stats in anEq[] etc. */
+  int i;                      /* Index of first sample >= pRec */
+  int iSample;                /* Smallest sample larger than or equal to pRec */
+  int iMin = 0;               /* Smallest sample not yet tested */
+  int iTest;                  /* Next sample to test */
+  int res;                    /* Result of comparison operation */
+  int nField;                 /* Number of fields in pRec */
+  tRowcnt iLower = 0;         /* anLt[] + anEq[] of largest sample pRec is > */
 
-  assert( roundUp==0 || roundUp==1 );
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER( pParse );
+#endif
+  assert( pRec!=0 );
   assert( pIdx->nSample>0 );
-  if( pVal==0 ) return SQLITE_ERROR;
-  n = pIdx->aiRowEst[0];
-  aSample = pIdx->aSample;
-  eType = sqlite3_value_type(pVal);
-
-  if( eType==SQLITE_INTEGER ){
-    v = sqlite3_value_int64(pVal);
-    r = (i64)v;
-    for(i=0; i<pIdx->nSample; i++){
-      if( aSample[i].eType==SQLITE_NULL ) continue;
-      if( aSample[i].eType>=SQLITE_TEXT ) break;
-      if( aSample[i].eType==SQLITE_INTEGER ){
-        if( aSample[i].u.i>=v ){
-          isEq = aSample[i].u.i==v;
-          break;
-        }
-      }else{
-        assert( aSample[i].eType==SQLITE_FLOAT );
-        if( aSample[i].u.r>=r ){
-          isEq = aSample[i].u.r==r;
-          break;
-        }
-      }
-    }
-  }else if( eType==SQLITE_FLOAT ){
-    r = sqlite3_value_double(pVal);
-    for(i=0; i<pIdx->nSample; i++){
-      if( aSample[i].eType==SQLITE_NULL ) continue;
-      if( aSample[i].eType>=SQLITE_TEXT ) break;
-      if( aSample[i].eType==SQLITE_FLOAT ){
-        rS = aSample[i].u.r;
-      }else{
-        rS = aSample[i].u.i;
-      }
-      if( rS>=r ){
-        isEq = rS==r;
-        break;
-      }
-    }
-  }else if( eType==SQLITE_NULL ){
-    i = 0;
-    if( aSample[0].eType==SQLITE_NULL ) isEq = 1;
-  }else{
-    assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
-    for(i=0; i<pIdx->nSample; i++){
-      if( aSample[i].eType==SQLITE_TEXT || aSample[i].eType==SQLITE_BLOB ){
-        break;
+  assert( pRec->nField>0 && pRec->nField<=pIdx->nSampleCol );
+
+  /* Do a binary search to find the first sample greater than or equal
+  ** to pRec. If pRec contains a single field, the set of samples to search
+  ** is simply the aSample[] array. If the samples in aSample[] contain more
+  ** than one fields, all fields following the first are ignored.
+  **
+  ** If pRec contains N fields, where N is more than one, then as well as the
+  ** samples in aSample[] (truncated to N fields), the search also has to
+  ** consider prefixes of those samples. For example, if the set of samples
+  ** in aSample is:
+  **
+  **     aSample[0] = (a, 5) 
+  **     aSample[1] = (a, 10) 
+  **     aSample[2] = (b, 5) 
+  **     aSample[3] = (c, 100) 
+  **     aSample[4] = (c, 105)
+  **
+  ** Then the search space should ideally be the samples above and the 
+  ** unique prefixes [a], [b] and [c]. But since that is hard to organize, 
+  ** the code actually searches this set:
+  **
+  **     0: (a) 
+  **     1: (a, 5) 
+  **     2: (a, 10) 
+  **     3: (a, 10) 
+  **     4: (b) 
+  **     5: (b, 5) 
+  **     6: (c) 
+  **     7: (c, 100) 
+  **     8: (c, 105)
+  **     9: (c, 105)
+  **
+  ** For each sample in the aSample[] array, N samples are present in the
+  ** effective sample array. In the above, samples 0 and 1 are based on 
+  ** sample aSample[0]. Samples 2 and 3 on aSample[1] etc.
+  **
+  ** Often, sample i of each block of N effective samples has (i+1) fields.
+  ** Except, each sample may be extended to ensure that it is greater than or
+  ** equal to the previous sample in the array. For example, in the above, 
+  ** sample 2 is the first sample of a block of N samples, so at first it 
+  ** appears that it should be 1 field in size. However, that would make it 
+  ** smaller than sample 1, so the binary search would not work. As a result, 
+  ** it is extended to two fields. The duplicates that this creates do not 
+  ** cause any problems.
+  */
+  nField = pRec->nField;
+  iCol = 0;
+  iSample = pIdx->nSample * nField;
+  do{
+    int iSamp;                    /* Index in aSample[] of test sample */
+    int n;                        /* Number of fields in test sample */
+
+    iTest = (iMin+iSample)/2;
+    iSamp = iTest / nField;
+    if( iSamp>0 ){
+      /* The proposed effective sample is a prefix of sample aSample[iSamp].
+      ** Specifically, the shortest prefix of at least (1 + iTest%nField) 
+      ** fields that is greater than the previous effective sample.  */
+      for(n=(iTest % nField) + 1; n<nField; n++){
+        if( aSample[iSamp-1].anLt[n-1]!=aSample[iSamp].anLt[n-1] ) break;
       }
+    }else{
+      n = iTest + 1;
+    }
+
+    pRec->nField = n;
+    res = sqlite3VdbeRecordCompare(aSample[iSamp].n, aSample[iSamp].p, pRec);
+    if( res<0 ){
+      iLower = aSample[iSamp].anLt[n-1] + aSample[iSamp].anEq[n-1];
+      iMin = iTest+1;
+    }else if( res==0 && n<nField ){
+      iLower = aSample[iSamp].anLt[n-1];
+      iMin = iTest+1;
+      res = -1;
+    }else{
+      iSample = iTest;
+      iCol = n-1;
     }
-    if( i<pIdx->nSample ){      
-      sqlite3 *db = pParse->db;
-      CollSeq *pColl;
-      const u8 *z;
-      if( eType==SQLITE_BLOB ){
-        z = (const u8 *)sqlite3_value_blob(pVal);
-        pColl = db->pDfltColl;
-        assert( pColl->enc==SQLITE_UTF8 );
-      }else{
-        pColl = sqlite3GetCollSeq(db, SQLITE_UTF8, 0, *pIdx->azColl);
-        if( pColl==0 ){
-          sqlite3ErrorMsg(pParse, "no such collation sequence: %s",
-                          *pIdx->azColl);
-          return SQLITE_ERROR;
-        }
-        z = (const u8 *)sqlite3ValueText(pVal, pColl->enc);
-        if( !z ){
-          return SQLITE_NOMEM;
-        }
-        assert( z && pColl && pColl->xCmp );
+  }while( res && iMin<iSample );
+  i = iSample / nField;
+
+#ifdef SQLITE_DEBUG
+  /* The following assert statements check that the binary search code
+  ** above found the right answer. This block serves no purpose other
+  ** than to invoke the asserts.  */
+  if( pParse->db->mallocFailed==0 ){
+    if( res==0 ){
+      /* If (res==0) is true, then pRec must be equal to sample i. */
+      assert( i<pIdx->nSample );
+      assert( iCol==nField-1 );
+      pRec->nField = nField;
+      assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec) 
+           || pParse->db->mallocFailed 
+      );
+    }else{
+      /* Unless i==pIdx->nSample, indicating that pRec is larger than
+      ** all samples in the aSample[] array, pRec must be smaller than the
+      ** (iCol+1) field prefix of sample i.  */
+      assert( i<=pIdx->nSample && i>=0 );
+      pRec->nField = iCol+1;
+      assert( i==pIdx->nSample 
+           || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
+           || pParse->db->mallocFailed );
+
+      /* if i==0 and iCol==0, then record pRec is smaller than all samples
+      ** in the aSample[] array. Otherwise, if (iCol>0) then pRec must
+      ** be greater than or equal to the (iCol) field prefix of sample i.
+      ** If (i>0), then pRec must also be greater than sample (i-1).  */
+      if( iCol>0 ){
+        pRec->nField = iCol;
+        assert( sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)<=0
+             || pParse->db->mallocFailed );
       }
-      n = sqlite3ValueBytes(pVal, pColl->enc);
-  
-      for(; i<pIdx->nSample; i++){
-        int c;
-        int eSampletype = aSample[i].eType;
-        if( eSampletype<eType ) continue;
-        if( eSampletype!=eType ) break;
-#ifndef SQLITE_OMIT_UTF16
-        if( pColl->enc!=SQLITE_UTF8 ){
-          int nSample;
-          char *zSample = sqlite3Utf8to16(
-              db, pColl->enc, aSample[i].u.z, aSample[i].nByte, &nSample
-          );
-          if( !zSample ){
-            assert( db->mallocFailed );
-            return SQLITE_NOMEM;
-          }
-          c = pColl->xCmp(pColl->pUser, nSample, zSample, n, z);
-          sqlite3DbFree(db, zSample);
-        }else
-#endif
-        {
-          c = pColl->xCmp(pColl->pUser, aSample[i].nByte, aSample[i].u.z, n, z);
-        }
-        if( c>=0 ){
-          if( c==0 ) isEq = 1;
-          break;
-        }
+      if( i>0 ){
+        pRec->nField = nField;
+        assert( sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
+             || pParse->db->mallocFailed );
       }
     }
   }
+#endif /* ifdef SQLITE_DEBUG */
 
-  /* At this point, aSample[i] is the first sample that is greater than
-  ** or equal to pVal.  Or if i==pIdx->nSample, then all samples are less
-  ** than pVal.  If aSample[i]==pVal, then isEq==1.
-  */
-  if( isEq ){
-    assert( i<pIdx->nSample );
-    aStat[0] = aSample[i].nLt;
-    aStat[1] = aSample[i].nEq;
+  if( res==0 ){
+    /* Record pRec is equal to sample i */
+    assert( iCol==nField-1 );
+    aStat[0] = aSample[i].anLt[iCol];
+    aStat[1] = aSample[i].anEq[iCol];
   }else{
-    tRowcnt iLower, iUpper, iGap;
-    if( i==0 ){
-      iLower = 0;
-      iUpper = aSample[0].nLt;
+    /* At this point, the (iCol+1) field prefix of aSample[i] is the first 
+    ** sample that is greater than pRec. Or, if i==pIdx->nSample then pRec
+    ** is larger than all samples in the array. */
+    tRowcnt iUpper, iGap;
+    if( i>=pIdx->nSample ){
+      iUpper = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
     }else{
-      iUpper = i>=pIdx->nSample ? n : aSample[i].nLt;
-      iLower = aSample[i-1].nEq + aSample[i-1].nLt;
+      iUpper = aSample[i].anLt[iCol];
     }
-    aStat[1] = pIdx->avgEq;
+
     if( iLower>=iUpper ){
       iGap = 0;
     }else{
@@ -103303,45 +127876,160 @@ static int whereKeyStats(
       iGap = iGap/3;
     }
     aStat[0] = iLower + iGap;
+    aStat[1] = pIdx->aAvgEq[iCol];
   }
-  return SQLITE_OK;
+
+  /* Restore the pRec->nField value before returning.  */
+  pRec->nField = nField;
+  return i;
 }
-#endif /* SQLITE_ENABLE_STAT3 */
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
 /*
-** If expression pExpr represents a literal value, set *pp to point to
-** an sqlite3_value structure containing the same value, with affinity
-** aff applied to it, before returning. It is the responsibility of the 
-** caller to eventually release this structure by passing it to 
-** sqlite3ValueFree().
+** If it is not NULL, pTerm is a term that provides an upper or lower
+** bound on a range scan. Without considering pTerm, it is estimated 
+** that the scan will visit nNew rows. This function returns the number
+** estimated to be visited after taking pTerm into account.
 **
-** If the current parse is a recompile (sqlite3Reprepare()) and pExpr
-** is an SQL variable that currently has a non-NULL value bound to it,
-** create an sqlite3_value structure containing this value, again with
-** affinity aff applied to it, instead.
+** If the user explicitly specified a likelihood() value for this term,
+** then the return value is the likelihood multiplied by the number of
+** input rows. Otherwise, this function assumes that an "IS NOT NULL" term
+** has a likelihood of 0.50, and any other term a likelihood of 0.25.
+*/
+static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
+  LogEst nRet = nNew;
+  if( pTerm ){
+    if( pTerm->truthProb<=0 ){
+      nRet += pTerm->truthProb;
+    }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){
+      nRet -= 20;        assert( 20==sqlite3LogEst(4) );
+    }
+  }
+  return nRet;
+}
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Return the affinity for a single column of an index.
+*/
+static char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){
+  assert( iCol>=0 && iCol<pIdx->nColumn );
+  if( !pIdx->zColAff ){
+    if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;
+  }
+  return pIdx->zColAff[iCol];
+}
+#endif
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/* 
+** This function is called to estimate the number of rows visited by a
+** range-scan on a skip-scan index. For example:
+**
+**   CREATE INDEX i1 ON t1(a, b, c);
+**   SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;
+**
+** Value pLoop->nOut is currently set to the estimated number of rows 
+** visited for scanning (a=? AND b=?). This function reduces that estimate 
+** by some factor to account for the (c BETWEEN ? AND ?) expression based
+** on the stat4 data for the index. this scan will be peformed multiple 
+** times (once for each (a,b) combination that matches a=?) is dealt with 
+** by the caller.
+**
+** It does this by scanning through all stat4 samples, comparing values
+** extracted from pLower and pUpper with the corresponding column in each
+** sample. If L and U are the number of samples found to be less than or
+** equal to the values extracted from pLower and pUpper respectively, and
+** N is the total number of samples, the pLoop->nOut value is adjusted
+** as follows:
+**
+**   nOut = nOut * ( min(U - L, 1) / N )
 **
-** If neither of the above apply, set *pp to NULL.
+** If pLower is NULL, or a value cannot be extracted from the term, L is
+** set to zero. If pUpper is NULL, or a value cannot be extracted from it,
+** U is set to N.
 **
-** If an error occurs, return an error code. Otherwise, SQLITE_OK.
+** Normally, this function sets *pbDone to 1 before returning. However,
+** if no value can be extracted from either pLower or pUpper (and so the
+** estimate of the number of rows delivered remains unchanged), *pbDone
+** is left as is.
+**
+** If an error occurs, an SQLite error code is returned. Otherwise, 
+** SQLITE_OK.
 */
-#ifdef SQLITE_ENABLE_STAT3
-static int valueFromExpr(
-  Parse *pParse, 
-  Expr *pExpr, 
-  u8 aff, 
-  sqlite3_value **pp
+static int whereRangeSkipScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
+  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
+  WhereLoop *pLoop,    /* Update the .nOut value of this loop */
+  int *pbDone          /* Set to true if at least one expr. value extracted */
 ){
-  if( pExpr->op==TK_VARIABLE
-   || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
-  ){
-    int iVar = pExpr->iColumn;
-    sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
-    *pp = sqlite3VdbeGetValue(pParse->pReprepare, iVar, aff);
-    return SQLITE_OK;
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+  sqlite3 *db = pParse->db;
+  int nLower = -1;
+  int nUpper = p->nSample+1;
+  int rc = SQLITE_OK;
+  u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);
+  CollSeq *pColl;
+  
+  sqlite3_value *p1 = 0;          /* Value extracted from pLower */
+  sqlite3_value *p2 = 0;          /* Value extracted from pUpper */
+  sqlite3_value *pVal = 0;        /* Value extracted from record */
+
+  pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);
+  if( pLower ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);
+    nLower = 0;
+  }
+  if( pUpper && rc==SQLITE_OK ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);
+    nUpper = p2 ? 0 : p->nSample;
   }
-  return sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, aff, pp);
+
+  if( p1 || p2 ){
+    int i;
+    int nDiff;
+    for(i=0; rc==SQLITE_OK && i<p->nSample; i++){
+      rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);
+      if( rc==SQLITE_OK && p1 ){
+        int res = sqlite3MemCompare(p1, pVal, pColl);
+        if( res>=0 ) nLower++;
+      }
+      if( rc==SQLITE_OK && p2 ){
+        int res = sqlite3MemCompare(p2, pVal, pColl);
+        if( res>=0 ) nUpper++;
+      }
+    }
+    nDiff = (nUpper - nLower);
+    if( nDiff<=0 ) nDiff = 1;
+
+    /* If there is both an upper and lower bound specified, and the 
+    ** comparisons indicate that they are close together, use the fallback
+    ** method (assume that the scan visits 1/64 of the rows) for estimating
+    ** the number of rows visited. Otherwise, estimate the number of rows
+    ** using the method described in the header comment for this function. */
+    if( nDiff!=1 || pUpper==0 || pLower==0 ){
+      int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));
+      pLoop->nOut -= nAdjust;
+      *pbDone = 1;
+      WHERETRACE(0x10, ("range skip-scan regions: %u..%u  adjust=%d est=%d\n",
+                           nLower, nUpper, nAdjust*-1, pLoop->nOut));
+    }
+
+  }else{
+    assert( *pbDone==0 );
+  }
+
+  sqlite3ValueFree(p1);
+  sqlite3ValueFree(p2);
+  sqlite3ValueFree(pVal);
+
+  return rc;
 }
-#endif
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
 /*
 ** This function is used to estimate the number of rows that will be visited
@@ -103358,97 +128046,189 @@ static int valueFromExpr(
 ** If either of the upper or lower bound is not present, then NULL is passed in
 ** place of the corresponding WhereTerm.
 **
-** The nEq parameter is passed the index of the index column subject to the
-** range constraint. Or, equivalently, the number of equality constraints
-** optimized by the proposed index scan. For example, assuming index p is
-** on t1(a, b), and the SQL query is:
+** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
+** column subject to the range constraint. Or, equivalently, the number of
+** equality constraints optimized by the proposed index scan. For example,
+** assuming index p is on t1(a, b), and the SQL query is:
 **
 **   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
 **
-** then nEq should be passed the value 1 (as the range restricted column,
-** b, is the second left-most column of the index). Or, if the query is:
+** then nEq is set to 1 (as the range restricted column, b, is the second 
+** left-most column of the index). Or, if the query is:
 **
 **   ... FROM t1 WHERE a > ? AND a < ? ...
 **
-** then nEq should be passed 0.
-**
-** The returned value is an integer divisor to reduce the estimated
-** search space.  A return value of 1 means that range constraints are
-** no help at all.  A return value of 2 means range constraints are
-** expected to reduce the search space by half.  And so forth...
+** then nEq is set to 0.
 **
-** In the absence of sqlite_stat3 ANALYZE data, each range inequality
-** reduces the search space by a factor of 4.  Hence a single constraint (x>?)
-** results in a return of 4 and a range constraint (x>? AND x<?) results
-** in a return of 16.
+** When this function is called, *pnOut is set to the sqlite3LogEst() of the
+** number of rows that the index scan is expected to visit without 
+** considering the range constraints. If nEq is 0, then *pnOut is the number of 
+** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
+** to account for the range constraints pLower and pUpper.
+** 
+** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
+** used, a single range inequality reduces the search space by a factor of 4. 
+** and a pair of constraints (x>? AND x<?) reduces the expected number of
+** rows visited by a factor of 64.
 */
 static int whereRangeScanEst(
   Parse *pParse,       /* Parsing & code generating context */
-  Index *p,            /* The index containing the range-compared column; "x" */
-  int nEq,             /* index into p->aCol[] of the range-compared column */
+  WhereLoopBuilder *pBuilder,
   WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
   WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
-  double *pRangeDiv   /* OUT: Reduce search space by this divisor */
+  WhereLoop *pLoop     /* Modify the .nOut and maybe .rRun fields */
 ){
   int rc = SQLITE_OK;
-
-#ifdef SQLITE_ENABLE_STAT3
-
-  if( nEq==0 && p->nSample ){
-    sqlite3_value *pRangeVal;
-    tRowcnt iLower = 0;
-    tRowcnt iUpper = p->aiRowEst[0];
-    tRowcnt a[2];
-    u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity;
-
-    if( pLower ){
-      Expr *pExpr = pLower->pExpr->pRight;
-      rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
-      assert( pLower->eOperator==WO_GT || pLower->eOperator==WO_GE );
-      if( rc==SQLITE_OK
-       && whereKeyStats(pParse, p, pRangeVal, 0, a)==SQLITE_OK
-      ){
+  int nOut = pLoop->nOut;
+  LogEst nNew;
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+
+  if( p->nSample>0 && nEq<p->nSampleCol ){
+    if( nEq==pBuilder->nRecValid ){
+      UnpackedRecord *pRec = pBuilder->pRec;
+      tRowcnt a[2];
+      u8 aff;
+
+      /* Variable iLower will be set to the estimate of the number of rows in 
+      ** the index that are less than the lower bound of the range query. The
+      ** lower bound being the concatenation of $P and $L, where $P is the
+      ** key-prefix formed by the nEq values matched against the nEq left-most
+      ** columns of the index, and $L is the value in pLower.
+      **
+      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
+      ** is not a simple variable or literal value), the lower bound of the
+      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
+      ** if $L is available, whereKeyStats() is called for both ($P) and 
+      ** ($P:$L) and the larger of the two returned values is used.
+      **
+      ** Similarly, iUpper is to be set to the estimate of the number of rows
+      ** less than the upper bound of the range query. Where the upper bound
+      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
+      ** of iUpper are requested of whereKeyStats() and the smaller used.
+      **
+      ** The number of rows between the two bounds is then just iUpper-iLower.
+      */
+      tRowcnt iLower;     /* Rows less than the lower bound */
+      tRowcnt iUpper;     /* Rows less than the upper bound */
+      int iLwrIdx = -2;   /* aSample[] for the lower bound */
+      int iUprIdx = -1;   /* aSample[] for the upper bound */
+
+      if( pRec ){
+        testcase( pRec->nField!=pBuilder->nRecValid );
+        pRec->nField = pBuilder->nRecValid;
+      }
+      aff = sqlite3IndexColumnAffinity(pParse->db, p, nEq);
+      assert( nEq!=p->nKeyCol || aff==SQLITE_AFF_INTEGER );
+      /* Determine iLower and iUpper using ($P) only. */
+      if( nEq==0 ){
+        iLower = 0;
+        iUpper = p->nRowEst0;
+      }else{
+        /* Note: this call could be optimized away - since the same values must 
+        ** have been requested when testing key $P in whereEqualScanEst().  */
+        whereKeyStats(pParse, p, pRec, 0, a);
         iLower = a[0];
-        if( pLower->eOperator==WO_GT ) iLower += a[1];
+        iUpper = a[0] + a[1];
+      }
+
+      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
+      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
+      assert( p->aSortOrder!=0 );
+      if( p->aSortOrder[nEq] ){
+        /* The roles of pLower and pUpper are swapped for a DESC index */
+        SWAP(WhereTerm*, pLower, pUpper);
+      }
+
+      /* If possible, improve on the iLower estimate using ($P:$L). */
+      if( pLower ){
+        int bOk;                    /* True if value is extracted from pExpr */
+        Expr *pExpr = pLower->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
+        if( rc==SQLITE_OK && bOk ){
+          tRowcnt iNew;
+          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
+          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
+          if( iNew>iLower ) iLower = iNew;
+          nOut--;
+          pLower = 0;
+        }
       }
-      sqlite3ValueFree(pRangeVal);
-    }
-    if( rc==SQLITE_OK && pUpper ){
-      Expr *pExpr = pUpper->pExpr->pRight;
-      rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
-      assert( pUpper->eOperator==WO_LT || pUpper->eOperator==WO_LE );
-      if( rc==SQLITE_OK
-       && whereKeyStats(pParse, p, pRangeVal, 1, a)==SQLITE_OK
-      ){
-        iUpper = a[0];
-        if( pUpper->eOperator==WO_LE ) iUpper += a[1];
+
+      /* If possible, improve on the iUpper estimate using ($P:$U). */
+      if( pUpper ){
+        int bOk;                    /* True if value is extracted from pExpr */
+        Expr *pExpr = pUpper->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
+        if( rc==SQLITE_OK && bOk ){
+          tRowcnt iNew;
+          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
+          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
+          if( iNew<iUpper ) iUpper = iNew;
+          nOut--;
+          pUpper = 0;
+        }
       }
-      sqlite3ValueFree(pRangeVal);
-    }
-    if( rc==SQLITE_OK ){
-      if( iUpper<=iLower ){
-        *pRangeDiv = (double)p->aiRowEst[0];
-      }else{
-        *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower);
+
+      pBuilder->pRec = pRec;
+      if( rc==SQLITE_OK ){
+        if( iUpper>iLower ){
+          nNew = sqlite3LogEst(iUpper - iLower);
+          /* TUNING:  If both iUpper and iLower are derived from the same
+          ** sample, then assume they are 4x more selective.  This brings
+          ** the estimated selectivity more in line with what it would be
+          ** if estimated without the use of STAT3/4 tables. */
+          if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );
+        }else{
+          nNew = 10;        assert( 10==sqlite3LogEst(2) );
+        }
+        if( nNew<nOut ){
+          nOut = nNew;
+        }
+        WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",
+                           (u32)iLower, (u32)iUpper, nOut));
       }
-      WHERETRACE(("range scan regions: %u..%u  div=%g\n",
-                  (u32)iLower, (u32)iUpper, *pRangeDiv));
-      return SQLITE_OK;
+    }else{
+      int bDone = 0;
+      rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone);
+      if( bDone ) return rc;
     }
   }
 #else
   UNUSED_PARAMETER(pParse);
-  UNUSED_PARAMETER(p);
-  UNUSED_PARAMETER(nEq);
-#endif
+  UNUSED_PARAMETER(pBuilder);
   assert( pLower || pUpper );
-  *pRangeDiv = (double)1;
-  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4;
-  if( pUpper ) *pRangeDiv *= (double)4;
+#endif
+  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
+  nNew = whereRangeAdjust(pLower, nOut);
+  nNew = whereRangeAdjust(pUpper, nNew);
+
+  /* TUNING: If there is both an upper and lower limit and neither limit
+  ** has an application-defined likelihood(), assume the range is
+  ** reduced by an additional 75%. This means that, by default, an open-ended
+  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
+  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
+  ** match 1/64 of the index. */ 
+  if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
+    nNew -= 20;
+  }
+
+  nOut -= (pLower!=0) + (pUpper!=0);
+  if( nNew<10 ) nNew = 10;
+  if( nNew<nOut ) nOut = nNew;
+#if defined(WHERETRACE_ENABLED)
+  if( pLoop->nOut>nOut ){
+    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
+                    pLoop->nOut, nOut));
+  }
+#endif
+  pLoop->nOut = (LogEst)nOut;
   return rc;
 }
 
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
 ** Estimate the number of rows that will be returned based on
 ** an equality constraint x=VALUE and where that VALUE occurs in
@@ -103468,37 +128248,54 @@ static int whereRangeScanEst(
 */
 static int whereEqualScanEst(
   Parse *pParse,       /* Parsing & code generating context */
-  Index *p,            /* The index whose left-most column is pTerm */
+  WhereLoopBuilder *pBuilder,
   Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
-  double *pnRow        /* Write the revised row estimate here */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
 ){
-  sqlite3_value *pRhs = 0;  /* VALUE on right-hand side of pTerm */
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  int nEq = pBuilder->pNew->u.btree.nEq;
+  UnpackedRecord *pRec = pBuilder->pRec;
   u8 aff;                   /* Column affinity */
   int rc;                   /* Subfunction return code */
   tRowcnt a[2];             /* Statistics */
+  int bOk;
 
+  assert( nEq>=1 );
+  assert( nEq<=p->nColumn );
   assert( p->aSample!=0 );
   assert( p->nSample>0 );
-  aff = p->pTable->aCol[p->aiColumn[0]].affinity;
-  if( pExpr ){
-    rc = valueFromExpr(pParse, pExpr, aff, &pRhs);
-    if( rc ) goto whereEqualScanEst_cancel;
-  }else{
-    pRhs = sqlite3ValueNew(pParse->db);
+  assert( pBuilder->nRecValid<nEq );
+
+  /* If values are not available for all fields of the index to the left
+  ** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */
+  if( pBuilder->nRecValid<(nEq-1) ){
+    return SQLITE_NOTFOUND;
   }
-  if( pRhs==0 ) return SQLITE_NOTFOUND;
-  rc = whereKeyStats(pParse, p, pRhs, 0, a);
-  if( rc==SQLITE_OK ){
-    WHERETRACE(("equality scan regions: %d\n", (int)a[1]));
-    *pnRow = a[1];
+
+  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
+  ** below would return the same value.  */
+  if( nEq>=p->nColumn ){
+    *pnRow = 1;
+    return SQLITE_OK;
   }
-whereEqualScanEst_cancel:
-  sqlite3ValueFree(pRhs);
+
+  aff = sqlite3IndexColumnAffinity(pParse->db, p, nEq-1);
+  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq-1, &bOk);
+  pBuilder->pRec = pRec;
+  if( rc!=SQLITE_OK ) return rc;
+  if( bOk==0 ) return SQLITE_NOTFOUND;
+  pBuilder->nRecValid = nEq;
+
+  whereKeyStats(pParse, p, pRec, 0, a);
+  WHERETRACE(0x10,("equality scan regions %s(%d): %d\n",
+                   p->zName, nEq-1, (int)a[1]));
+  *pnRow = a[1];
+  
   return rc;
 }
-#endif /* defined(SQLITE_ENABLE_STAT3) */
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
-#ifdef SQLITE_ENABLE_STAT3
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
 /*
 ** Estimate the number of rows that will be returned based on
 ** an IN constraint where the right-hand side of the IN operator
@@ -103517,1682 +128314,2492 @@ whereEqualScanEst_cancel:
 */
 static int whereInScanEst(
   Parse *pParse,       /* Parsing & code generating context */
-  Index *p,            /* The index whose left-most column is pTerm */
+  WhereLoopBuilder *pBuilder,
   ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
-  double *pnRow        /* Write the revised row estimate here */
-){
-  int rc = SQLITE_OK;         /* Subfunction return code */
-  double nEst;                /* Number of rows for a single term */
-  double nRowEst = (double)0; /* New estimate of the number of rows */
-  int i;                      /* Loop counter */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
+){
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);
+  int nRecValid = pBuilder->nRecValid;
+  int rc = SQLITE_OK;     /* Subfunction return code */
+  tRowcnt nEst;           /* Number of rows for a single term */
+  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
+  int i;                  /* Loop counter */
 
   assert( p->aSample!=0 );
   for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
-    nEst = p->aiRowEst[0];
-    rc = whereEqualScanEst(pParse, p, pList->a[i].pExpr, &nEst);
+    nEst = nRow0;
+    rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
     nRowEst += nEst;
+    pBuilder->nRecValid = nRecValid;
   }
+
   if( rc==SQLITE_OK ){
-    if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
+    if( nRowEst > nRow0 ) nRowEst = nRow0;
     *pnRow = nRowEst;
-    WHERETRACE(("IN row estimate: est=%g\n", nRowEst));
+    WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
   }
+  assert( pBuilder->nRecValid==nRecValid );
   return rc;
 }
-#endif /* defined(SQLITE_ENABLE_STAT3) */
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
 
+#ifdef WHERETRACE_ENABLED
 /*
-** Find the best query plan for accessing a particular table.  Write the
-** best query plan and its cost into the WhereCost object supplied as the
-** last parameter.
-**
-** The lowest cost plan wins.  The cost is an estimate of the amount of
-** CPU and disk I/O needed to process the requested result.
-** Factors that influence cost include:
-**
-**    *  The estimated number of rows that will be retrieved.  (The
-**       fewer the better.)
-**
-**    *  Whether or not sorting must occur.
-**
-**    *  Whether or not there must be separate lookups in the
-**       index and in the main table.
-**
-** If there was an INDEXED BY clause (pSrc->pIndex) attached to the table in
-** the SQL statement, then this function only considers plans using the 
-** named index. If no such plan is found, then the returned cost is
-** SQLITE_BIG_DBL. If a plan is found that uses the named index, 
-** then the cost is calculated in the usual way.
-**
-** If a NOT INDEXED clause (pSrc->notIndexed!=0) was attached to the table 
-** in the SELECT statement, then no indexes are considered. However, the 
-** selected plan may still take advantage of the built-in rowid primary key
-** index.
+** Print the content of a WhereTerm object
 */
-static void bestBtreeIndex(
-  Parse *pParse,              /* The parsing context */
-  WhereClause *pWC,           /* The WHERE clause */
-  struct SrcList_item *pSrc,  /* The FROM clause term to search */
-  Bitmask notReady,           /* Mask of cursors not available for indexing */
-  Bitmask notValid,           /* Cursors not available for any purpose */
-  ExprList *pOrderBy,         /* The ORDER BY clause */
-  ExprList *pDistinct,        /* The select-list if query is DISTINCT */
-  WhereCost *pCost            /* Lowest cost query plan */
-){
-  int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
-  Index *pProbe;              /* An index we are evaluating */
-  Index *pIdx;                /* Copy of pProbe, or zero for IPK index */
-  int eqTermMask;             /* Current mask of valid equality operators */
-  int idxEqTermMask;          /* Index mask of valid equality operators */
-  Index sPk;                  /* A fake index object for the primary key */
-  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
-  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
-  int wsFlagMask;             /* Allowed flags in pCost->plan.wsFlag */
-
-  /* Initialize the cost to a worst-case value */
-  memset(pCost, 0, sizeof(*pCost));
-  pCost->rCost = SQLITE_BIG_DBL;
-
-  /* If the pSrc table is the right table of a LEFT JOIN then we may not
-  ** use an index to satisfy IS NULL constraints on that table.  This is
-  ** because columns might end up being NULL if the table does not match -
-  ** a circumstance which the index cannot help us discover.  Ticket #2177.
-  */
-  if( pSrc->jointype & JT_LEFT ){
-    idxEqTermMask = WO_EQ|WO_IN;
+static void whereTermPrint(WhereTerm *pTerm, int iTerm){
+  if( pTerm==0 ){
+    sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
   }else{
-    idxEqTermMask = WO_EQ|WO_IN|WO_ISNULL;
-  }
-
-  if( pSrc->pIndex ){
-    /* An INDEXED BY clause specifies a particular index to use */
-    pIdx = pProbe = pSrc->pIndex;
-    wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
-    eqTermMask = idxEqTermMask;
-  }else{
-    /* There is no INDEXED BY clause.  Create a fake Index object in local
-    ** variable sPk to represent the rowid primary key index.  Make this
-    ** fake index the first in a chain of Index objects with all of the real
-    ** indices to follow */
-    Index *pFirst;                  /* First of real indices on the table */
-    memset(&sPk, 0, sizeof(Index));
-    sPk.nColumn = 1;
-    sPk.aiColumn = &aiColumnPk;
-    sPk.aiRowEst = aiRowEstPk;
-    sPk.onError = OE_Replace;
-    sPk.pTable = pSrc->pTab;
-    aiRowEstPk[0] = pSrc->pTab->nRowEst;
-    aiRowEstPk[1] = 1;
-    pFirst = pSrc->pTab->pIndex;
-    if( pSrc->notIndexed==0 ){
-      /* The real indices of the table are only considered if the
-      ** NOT INDEXED qualifier is omitted from the FROM clause */
-      sPk.pNext = pFirst;
+    char zType[4];
+    char zLeft[50];
+    memcpy(zType, "...", 4);
+    if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
+    if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';
+    if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
+    if( pTerm->eOperator & WO_SINGLE ){
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"left={%d:%d}",
+                       pTerm->leftCursor, pTerm->u.leftColumn);
+    }else if( (pTerm->eOperator & WO_OR)!=0 && pTerm->u.pOrInfo!=0 ){
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"indexable=0x%lld", 
+                       pTerm->u.pOrInfo->indexable);
+    }else{
+      sqlite3_snprintf(sizeof(zLeft),zLeft,"left=%d", pTerm->leftCursor);
     }
-    pProbe = &sPk;
-    wsFlagMask = ~(
-        WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE
-    );
-    eqTermMask = WO_EQ|WO_IN;
-    pIdx = 0;
+    sqlite3DebugPrintf(
+       "TERM-%-3d %p %s %-12s prob=%-3d op=0x%03x wtFlags=0x%04x\n",
+       iTerm, pTerm, zType, zLeft, pTerm->truthProb,
+       pTerm->eOperator, pTerm->wtFlags);
+    sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
   }
-
-  /* Loop over all indices looking for the best one to use
-  */
-  for(; pProbe; pIdx=pProbe=pProbe->pNext){
-    const tRowcnt * const aiRowEst = pProbe->aiRowEst;
-    double cost;                /* Cost of using pProbe */
-    double nRow;                /* Estimated number of rows in result set */
-    double log10N = (double)1;  /* base-10 logarithm of nRow (inexact) */
-    int rev;                    /* True to scan in reverse order */
-    int wsFlags = 0;
-    Bitmask used = 0;
-
-    /* The following variables are populated based on the properties of
-    ** index being evaluated. They are then used to determine the expected
-    ** cost and number of rows returned.
-    **
-    **  nEq: 
-    **    Number of equality terms that can be implemented using the index.
-    **    In other words, the number of initial fields in the index that
-    **    are used in == or IN or NOT NULL constraints of the WHERE clause.
-    **
-    **  nInMul:  
-    **    The "in-multiplier". This is an estimate of how many seek operations 
-    **    SQLite must perform on the index in question. For example, if the 
-    **    WHERE clause is:
-    **
-    **      WHERE a IN (1, 2, 3) AND b IN (4, 5, 6)
-    **
-    **    SQLite must perform 9 lookups on an index on (a, b), so nInMul is 
-    **    set to 9. Given the same schema and either of the following WHERE 
-    **    clauses:
-    **
-    **      WHERE a =  1
-    **      WHERE a >= 2
-    **
-    **    nInMul is set to 1.
-    **
-    **    If there exists a WHERE term of the form "x IN (SELECT ...)", then 
-    **    the sub-select is assumed to return 25 rows for the purposes of 
-    **    determining nInMul.
-    **
-    **  bInEst:  
-    **    Set to true if there was at least one "x IN (SELECT ...)" term used 
-    **    in determining the value of nInMul.  Note that the RHS of the
-    **    IN operator must be a SELECT, not a value list, for this variable
-    **    to be true.
-    **
-    **  rangeDiv:
-    **    An estimate of a divisor by which to reduce the search space due
-    **    to inequality constraints.  In the absence of sqlite_stat3 ANALYZE
-    **    data, a single inequality reduces the search space to 1/4rd its
-    **    original size (rangeDiv==4).  Two inequalities reduce the search
-    **    space to 1/16th of its original size (rangeDiv==16).
-    **
-    **  bSort:   
-    **    Boolean. True if there is an ORDER BY clause that will require an 
-    **    external sort (i.e. scanning the index being evaluated will not 
-    **    correctly order records).
-    **
-    **  bLookup: 
-    **    Boolean. True if a table lookup is required for each index entry
-    **    visited.  In other words, true if this is not a covering index.
-    **    This is always false for the rowid primary key index of a table.
-    **    For other indexes, it is true unless all the columns of the table
-    **    used by the SELECT statement are present in the index (such an
-    **    index is sometimes described as a covering index).
-    **    For example, given the index on (a, b), the second of the following 
-    **    two queries requires table b-tree lookups in order to find the value
-    **    of column c, but the first does not because columns a and b are
-    **    both available in the index.
-    **
-    **             SELECT a, b    FROM tbl WHERE a = 1;
-    **             SELECT a, b, c FROM tbl WHERE a = 1;
-    */
-    int nEq;                      /* Number of == or IN terms matching index */
-    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
-    int nInMul = 1;               /* Number of distinct equalities to lookup */
-    double rangeDiv = (double)1;  /* Estimated reduction in search space */
-    int nBound = 0;               /* Number of range constraints seen */
-    int bSort = !!pOrderBy;       /* True if external sort required */
-    int bDist = !!pDistinct;      /* True if index cannot help with DISTINCT */
-    int bLookup = 0;              /* True if not a covering index */
-    WhereTerm *pTerm;             /* A single term of the WHERE clause */
-#ifdef SQLITE_ENABLE_STAT3
-    WhereTerm *pFirstTerm = 0;    /* First term matching the index */
+}
 #endif
 
-    /* Determine the values of nEq and nInMul */
-    for(nEq=0; nEq<pProbe->nColumn; nEq++){
-      int j = pProbe->aiColumn[nEq];
-      pTerm = findTerm(pWC, iCur, j, notReady, eqTermMask, pIdx);
-      if( pTerm==0 ) break;
-      wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);
-      testcase( pTerm->pWC!=pWC );
-      if( pTerm->eOperator & WO_IN ){
-        Expr *pExpr = pTerm->pExpr;
-        wsFlags |= WHERE_COLUMN_IN;
-        if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-          /* "x IN (SELECT ...)":  Assume the SELECT returns 25 rows */
-          nInMul *= 25;
-          bInEst = 1;
-        }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
-          /* "x IN (value, value, ...)" */
-          nInMul *= pExpr->x.pList->nExpr;
-        }
-      }else if( pTerm->eOperator & WO_ISNULL ){
-        wsFlags |= WHERE_COLUMN_NULL;
-      }
-#ifdef SQLITE_ENABLE_STAT3
-      if( nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
-#endif
-      used |= pTerm->prereqRight;
-    }
-
-    /* Determine the value of rangeDiv */
-    if( nEq<pProbe->nColumn && pProbe->bUnordered==0 ){
-      int j = pProbe->aiColumn[nEq];
-      if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
-        WhereTerm *pTop = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pIdx);
-        WhereTerm *pBtm = findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pIdx);
-        whereRangeScanEst(pParse, pProbe, nEq, pBtm, pTop, &rangeDiv);
-        if( pTop ){
-          nBound = 1;
-          wsFlags |= WHERE_TOP_LIMIT;
-          used |= pTop->prereqRight;
-          testcase( pTop->pWC!=pWC );
-        }
-        if( pBtm ){
-          nBound++;
-          wsFlags |= WHERE_BTM_LIMIT;
-          used |= pBtm->prereqRight;
-          testcase( pBtm->pWC!=pWC );
-        }
-        wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE);
-      }
-    }else if( pProbe->onError!=OE_None ){
-      testcase( wsFlags & WHERE_COLUMN_IN );
-      testcase( wsFlags & WHERE_COLUMN_NULL );
-      if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
-        wsFlags |= WHERE_UNIQUE;
-      }
-    }
-
-    /* If there is an ORDER BY clause and the index being considered will
-    ** naturally scan rows in the required order, set the appropriate flags
-    ** in wsFlags. Otherwise, if there is an ORDER BY clause but the index
-    ** will scan rows in a different order, set the bSort variable.  */
-    if( isSortingIndex(
-          pParse, pWC->pMaskSet, pProbe, iCur, pOrderBy, nEq, wsFlags, &rev)
-    ){
-      bSort = 0;
-      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_ORDERBY;
-      wsFlags |= (rev ? WHERE_REVERSE : 0);
-    }
-
-    /* If there is a DISTINCT qualifier and this index will scan rows in
-    ** order of the DISTINCT expressions, clear bDist and set the appropriate
-    ** flags in wsFlags. */
-    if( isDistinctIndex(pParse, pWC, pProbe, iCur, pDistinct, nEq) ){
-      bDist = 0;
-      wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT;
-    }
-
-    /* If currently calculating the cost of using an index (not the IPK
-    ** index), determine if all required column data may be obtained without 
-    ** using the main table (i.e. if the index is a covering
-    ** index for this query). If it is, set the WHERE_IDX_ONLY flag in
-    ** wsFlags. Otherwise, set the bLookup variable to true.  */
-    if( pIdx && wsFlags ){
-      Bitmask m = pSrc->colUsed;
-      int j;
-      for(j=0; j<pIdx->nColumn; j++){
-        int x = pIdx->aiColumn[j];
-        if( x<BMS-1 ){
-          m &= ~(((Bitmask)1)<<x);
-        }
-      }
-      if( m==0 ){
-        wsFlags |= WHERE_IDX_ONLY;
-      }else{
-        bLookup = 1;
-      }
-    }
-
-    /*
-    ** Estimate the number of rows of output.  For an "x IN (SELECT...)"
-    ** constraint, do not let the estimate exceed half the rows in the table.
-    */
-    nRow = (double)(aiRowEst[nEq] * nInMul);
-    if( bInEst && nRow*2>aiRowEst[0] ){
-      nRow = aiRowEst[0]/2;
-      nInMul = (int)(nRow / aiRowEst[nEq]);
-    }
+#ifdef WHERETRACE_ENABLED
+/*
+** Show the complete content of a WhereClause
+*/
+SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC){
+  int i;
+  for(i=0; i<pWC->nTerm; i++){
+    whereTermPrint(&pWC->a[i], i);
+  }
+}
+#endif
 
-#ifdef SQLITE_ENABLE_STAT3
-    /* If the constraint is of the form x=VALUE or x IN (E1,E2,...)
-    ** and we do not think that values of x are unique and if histogram
-    ** data is available for column x, then it might be possible
-    ** to get a better estimate on the number of rows based on
-    ** VALUE and how common that value is according to the histogram.
-    */
-    if( nRow>(double)1 && nEq==1 && pFirstTerm!=0 && aiRowEst[1]>1 ){
-      assert( (pFirstTerm->eOperator & (WO_EQ|WO_ISNULL|WO_IN))!=0 );
-      if( pFirstTerm->eOperator & (WO_EQ|WO_ISNULL) ){
-        testcase( pFirstTerm->eOperator==WO_EQ );
-        testcase( pFirstTerm->eOperator==WO_ISNULL );
-        whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight, &nRow);
-      }else if( bInEst==0 ){
-        assert( pFirstTerm->eOperator==WO_IN );
-        whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList, &nRow);
+#ifdef WHERETRACE_ENABLED
+/*
+** Print a WhereLoop object for debugging purposes
+*/
+static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
+  WhereInfo *pWInfo = pWC->pWInfo;
+  int nb = 1+(pWInfo->pTabList->nSrc+3)/4;
+  struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
+  Table *pTab = pItem->pTab;
+  Bitmask mAll = (((Bitmask)1)<<(nb*4)) - 1;
+  sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
+                     p->iTab, nb, p->maskSelf, nb, p->prereq & mAll);
+  sqlite3DebugPrintf(" %12s",
+                     pItem->zAlias ? pItem->zAlias : pTab->zName);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    const char *zName;
+    if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
+      if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
+        int i = sqlite3Strlen30(zName) - 1;
+        while( zName[i]!='_' ) i--;
+        zName += i;
       }
-    }
-#endif /* SQLITE_ENABLE_STAT3 */
-
-    /* Adjust the number of output rows and downward to reflect rows
-    ** that are excluded by range constraints.
-    */
-    nRow = nRow/rangeDiv;
-    if( nRow<1 ) nRow = 1;
-
-    /* Experiments run on real SQLite databases show that the time needed
-    ** to do a binary search to locate a row in a table or index is roughly
-    ** log10(N) times the time to move from one row to the next row within
-    ** a table or index.  The actual times can vary, with the size of
-    ** records being an important factor.  Both moves and searches are
-    ** slower with larger records, presumably because fewer records fit
-    ** on one page and hence more pages have to be fetched.
-    **
-    ** The ANALYZE command and the sqlite_stat1 and sqlite_stat3 tables do
-    ** not give us data on the relative sizes of table and index records.
-    ** So this computation assumes table records are about twice as big
-    ** as index records
-    */
-    if( (wsFlags & WHERE_NOT_FULLSCAN)==0 ){
-      /* The cost of a full table scan is a number of move operations equal
-      ** to the number of rows in the table.
-      **
-      ** We add an additional 4x penalty to full table scans.  This causes
-      ** the cost function to err on the side of choosing an index over
-      ** choosing a full scan.  This 4x full-scan penalty is an arguable
-      ** decision and one which we expect to revisit in the future.  But
-      ** it seems to be working well enough at the moment.
-      */
-      cost = aiRowEst[0]*4;
+      sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
     }else{
-      log10N = estLog(aiRowEst[0]);
-      cost = nRow;
-      if( pIdx ){
-        if( bLookup ){
-          /* For an index lookup followed by a table lookup:
-          **    nInMul index searches to find the start of each index range
-          **  + nRow steps through the index
-          **  + nRow table searches to lookup the table entry using the rowid
-          */
-          cost += (nInMul + nRow)*log10N;
-        }else{
-          /* For a covering index:
-          **     nInMul index searches to find the initial entry 
-          **   + nRow steps through the index
-          */
-          cost += nInMul*log10N;
-        }
-      }else{
-        /* For a rowid primary key lookup:
-        **    nInMult table searches to find the initial entry for each range
-        **  + nRow steps through the table
-        */
-        cost += nInMul*log10N;
-      }
+      sqlite3DebugPrintf("%20s","");
     }
-
-    /* Add in the estimated cost of sorting the result.  Actual experimental
-    ** measurements of sorting performance in SQLite show that sorting time
-    ** adds C*N*log10(N) to the cost, where N is the number of rows to be 
-    ** sorted and C is a factor between 1.95 and 4.3.  We will split the
-    ** difference and select C of 3.0.
-    */
-    if( bSort ){
-      cost += nRow*estLog(nRow)*3;
+  }else{
+    char *z;
+    if( p->u.vtab.idxStr ){
+      z = sqlite3_mprintf("(%d,\"%s\",%x)",
+                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+    }else{
+      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
     }
-    if( bDist ){
-      cost += nRow*estLog(nRow)*3;
+    sqlite3DebugPrintf(" %-19s", z);
+    sqlite3_free(z);
+  }
+  if( p->wsFlags & WHERE_SKIPSCAN ){
+    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
+  }else{
+    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
+  }
+  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
+    int i;
+    for(i=0; i<p->nLTerm; i++){
+      whereTermPrint(p->aLTerm[i], i);
     }
+  }
+}
+#endif
 
-    /**** Cost of using this index has now been computed ****/
+/*
+** Convert bulk memory into a valid WhereLoop that can be passed
+** to whereLoopClear harmlessly.
+*/
+static void whereLoopInit(WhereLoop *p){
+  p->aLTerm = p->aLTermSpace;
+  p->nLTerm = 0;
+  p->nLSlot = ArraySize(p->aLTermSpace);
+  p->wsFlags = 0;
+}
 
-    /* If there are additional constraints on this table that cannot
-    ** be used with the current index, but which might lower the number
-    ** of output rows, adjust the nRow value accordingly.  This only 
-    ** matters if the current index is the least costly, so do not bother
-    ** with this step if we already know this index will not be chosen.
-    ** Also, never reduce the output row count below 2 using this step.
-    **
-    ** It is critical that the notValid mask be used here instead of
-    ** the notReady mask.  When computing an "optimal" index, the notReady
-    ** mask will only have one bit set - the bit for the current table.
-    ** The notValid mask, on the other hand, always has all bits set for
-    ** tables that are not in outer loops.  If notReady is used here instead
-    ** of notValid, then a optimal index that depends on inner joins loops
-    ** might be selected even when there exists an optimal index that has
-    ** no such dependency.
-    */
-    if( nRow>2 && cost<=pCost->rCost ){
-      int k;                       /* Loop counter */
-      int nSkipEq = nEq;           /* Number of == constraints to skip */
-      int nSkipRange = nBound;     /* Number of < constraints to skip */
-      Bitmask thisTab;             /* Bitmap for pSrc */
-
-      thisTab = getMask(pWC->pMaskSet, iCur);
-      for(pTerm=pWC->a, k=pWC->nTerm; nRow>2 && k; k--, pTerm++){
-        if( pTerm->wtFlags & TERM_VIRTUAL ) continue;
-        if( (pTerm->prereqAll & notValid)!=thisTab ) continue;
-        if( pTerm->eOperator & (WO_EQ|WO_IN|WO_ISNULL) ){
-          if( nSkipEq ){
-            /* Ignore the first nEq equality matches since the index
-            ** has already accounted for these */
-            nSkipEq--;
-          }else{
-            /* Assume each additional equality match reduces the result
-            ** set size by a factor of 10 */
-            nRow /= 10;
-          }
-        }else if( pTerm->eOperator & (WO_LT|WO_LE|WO_GT|WO_GE) ){
-          if( nSkipRange ){
-            /* Ignore the first nSkipRange range constraints since the index
-            ** has already accounted for these */
-            nSkipRange--;
-          }else{
-            /* Assume each additional range constraint reduces the result
-            ** set size by a factor of 3.  Indexed range constraints reduce
-            ** the search space by a larger factor: 4.  We make indexed range
-            ** more selective intentionally because of the subjective 
-            ** observation that indexed range constraints really are more
-            ** selective in practice, on average. */
-            nRow /= 3;
-          }
-        }else if( pTerm->eOperator!=WO_NOOP ){
-          /* Any other expression lowers the output row count by half */
-          nRow /= 2;
-        }
-      }
-      if( nRow<2 ) nRow = 2;
+/*
+** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.
+*/
+static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
+  if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
+    if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
+      sqlite3_free(p->u.vtab.idxStr);
+      p->u.vtab.needFree = 0;
+      p->u.vtab.idxStr = 0;
+    }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
+      sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
+      sqlite3DbFree(db, p->u.btree.pIndex);
+      p->u.btree.pIndex = 0;
     }
+  }
+}
 
+/*
+** Deallocate internal memory used by a WhereLoop object
+*/
+static void whereLoopClear(sqlite3 *db, WhereLoop *p){
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  whereLoopClearUnion(db, p);
+  whereLoopInit(p);
+}
 
-    WHERETRACE((
-      "%s(%s): nEq=%d nInMul=%d rangeDiv=%d bSort=%d bLookup=%d wsFlags=0x%x\n"
-      "         notReady=0x%llx log10N=%.1f nRow=%.1f cost=%.1f used=0x%llx\n",
-      pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk"), 
-      nEq, nInMul, (int)rangeDiv, bSort, bLookup, wsFlags,
-      notReady, log10N, nRow, cost, used
-    ));
-
-    /* If this index is the best we have seen so far, then record this
-    ** index and its cost in the pCost structure.
-    */
-    if( (!pIdx || wsFlags)
-     && (cost<pCost->rCost || (cost<=pCost->rCost && nRow<pCost->plan.nRow))
-    ){
-      pCost->rCost = cost;
-      pCost->used = used;
-      pCost->plan.nRow = nRow;
-      pCost->plan.wsFlags = (wsFlags&wsFlagMask);
-      pCost->plan.nEq = nEq;
-      pCost->plan.u.pIdx = pIdx;
-    }
-
-    /* If there was an INDEXED BY clause, then only that one index is
-    ** considered. */
-    if( pSrc->pIndex ) break;
+/*
+** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+*/
+static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
+  WhereTerm **paNew;
+  if( p->nLSlot>=n ) return SQLITE_OK;
+  n = (n+7)&~7;
+  paNew = sqlite3DbMallocRawNN(db, sizeof(p->aLTerm[0])*n);
+  if( paNew==0 ) return SQLITE_NOMEM_BKPT;
+  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  p->aLTerm = paNew;
+  p->nLSlot = n;
+  return SQLITE_OK;
+}
 
-    /* Reset masks for the next index in the loop */
-    wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
-    eqTermMask = idxEqTermMask;
+/*
+** Transfer content from the second pLoop into the first.
+*/
+static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
+  whereLoopClearUnion(db, pTo);
+  if( whereLoopResize(db, pTo, pFrom->nLTerm) ){
+    memset(&pTo->u, 0, sizeof(pTo->u));
+    return SQLITE_NOMEM_BKPT;
   }
-
-  /* If there is no ORDER BY clause and the SQLITE_ReverseOrder flag
-  ** is set, then reverse the order that the index will be scanned
-  ** in. This is used for application testing, to help find cases
-  ** where application behaviour depends on the (undefined) order that
-  ** SQLite outputs rows in in the absence of an ORDER BY clause.  */
-  if( !pOrderBy && pParse->db->flags & SQLITE_ReverseOrder ){
-    pCost->plan.wsFlags |= WHERE_REVERSE;
+  memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
+  memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
+  if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
+    pFrom->u.vtab.needFree = 0;
+  }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+    pFrom->u.btree.pIndex = 0;
   }
+  return SQLITE_OK;
+}
 
-  assert( pOrderBy || (pCost->plan.wsFlags&WHERE_ORDERBY)==0 );
-  assert( pCost->plan.u.pIdx==0 || (pCost->plan.wsFlags&WHERE_ROWID_EQ)==0 );
-  assert( pSrc->pIndex==0 
-       || pCost->plan.u.pIdx==0 
-       || pCost->plan.u.pIdx==pSrc->pIndex 
-  );
+/*
+** Delete a WhereLoop object
+*/
+static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
+  whereLoopClear(db, p);
+  sqlite3DbFree(db, p);
+}
 
-  WHERETRACE(("best index is: %s\n", 
-    ((pCost->plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ? "none" : 
-         pCost->plan.u.pIdx ? pCost->plan.u.pIdx->zName : "ipk")
-  ));
-  
-  bestOrClauseIndex(pParse, pWC, pSrc, notReady, notValid, pOrderBy, pCost);
-  bestAutomaticIndex(pParse, pWC, pSrc, notReady, pCost);
-  pCost->plan.wsFlags |= eqTermMask;
+/*
+** Free a WhereInfo structure
+*/
+static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
+  if( ALWAYS(pWInfo) ){
+    int i;
+    for(i=0; i<pWInfo->nLevel; i++){
+      WhereLevel *pLevel = &pWInfo->a[i];
+      if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
+        sqlite3DbFree(db, pLevel->u.in.aInLoop);
+      }
+    }
+    sqlite3WhereClauseClear(&pWInfo->sWC);
+    while( pWInfo->pLoops ){
+      WhereLoop *p = pWInfo->pLoops;
+      pWInfo->pLoops = p->pNextLoop;
+      whereLoopDelete(db, p);
+    }
+    sqlite3DbFree(db, pWInfo);
+  }
 }
 
 /*
-** Find the query plan for accessing table pSrc->pTab. Write the
-** best query plan and its cost into the WhereCost object supplied 
-** as the last parameter. This function may calculate the cost of
-** both real and virtual table scans.
+** Return TRUE if all of the following are true:
+**
+**   (1)  X has the same or lower cost that Y
+**   (2)  X is a proper subset of Y
+**   (3)  X skips at least as many columns as Y
+**
+** By "proper subset" we mean that X uses fewer WHERE clause terms
+** than Y and that every WHERE clause term used by X is also used
+** by Y.
+**
+** If X is a proper subset of Y then Y is a better choice and ought
+** to have a lower cost.  This routine returns TRUE when that cost 
+** relationship is inverted and needs to be adjusted.  The third rule
+** was added because if X uses skip-scan less than Y it still might
+** deserve a lower cost even if it is a proper subset of Y.
 */
-static void bestIndex(
-  Parse *pParse,              /* The parsing context */
-  WhereClause *pWC,           /* The WHERE clause */
-  struct SrcList_item *pSrc,  /* The FROM clause term to search */
-  Bitmask notReady,           /* Mask of cursors not available for indexing */
-  Bitmask notValid,           /* Cursors not available for any purpose */
-  ExprList *pOrderBy,         /* The ORDER BY clause */
-  WhereCost *pCost            /* Lowest cost query plan */
+static int whereLoopCheaperProperSubset(
+  const WhereLoop *pX,       /* First WhereLoop to compare */
+  const WhereLoop *pY        /* Compare against this WhereLoop */
 ){
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  if( IsVirtual(pSrc->pTab) ){
-    sqlite3_index_info *p = 0;
-    bestVirtualIndex(pParse, pWC, pSrc, notReady, notValid, pOrderBy, pCost,&p);
-    if( p->needToFreeIdxStr ){
-      sqlite3_free(p->idxStr);
+  int i, j;
+  if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
+    return 0; /* X is not a subset of Y */
+  }
+  if( pY->nSkip > pX->nSkip ) return 0;
+  if( pX->rRun >= pY->rRun ){
+    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
+    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
+  }
+  for(i=pX->nLTerm-1; i>=0; i--){
+    if( pX->aLTerm[i]==0 ) continue;
+    for(j=pY->nLTerm-1; j>=0; j--){
+      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
     }
-    sqlite3DbFree(pParse->db, p);
-  }else
-#endif
-  {
-    bestBtreeIndex(pParse, pWC, pSrc, notReady, notValid, pOrderBy, 0, pCost);
+    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
   }
+  return 1;  /* All conditions meet */
 }
 
 /*
-** Disable a term in the WHERE clause.  Except, do not disable the term
-** if it controls a LEFT OUTER JOIN and it did not originate in the ON
-** or USING clause of that join.
+** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so
+** that:
 **
-** Consider the term t2.z='ok' in the following queries:
+**   (1) pTemplate costs less than any other WhereLoops that are a proper
+**       subset of pTemplate
 **
-**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
-**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
-**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
+**       is a proper subset.
 **
-** The t2.z='ok' is disabled in the in (2) because it originates
-** in the ON clause.  The term is disabled in (3) because it is not part
-** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
+** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
+** WHERE clause terms than Y and that every WHERE clause term used by X is
+** also used by Y.
+*/
+static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
+  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
+  for(; p; p=p->pNextLoop){
+    if( p->iTab!=pTemplate->iTab ) continue;
+    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
+    if( whereLoopCheaperProperSubset(p, pTemplate) ){
+      /* Adjust pTemplate cost downward so that it is cheaper than its 
+      ** subset p. */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut - 1;
+    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
+      /* Adjust pTemplate cost upward so that it is costlier than p since
+      ** pTemplate is a proper subset of p */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut + 1;
+    }
+  }
+}
+
+/*
+** Search the list of WhereLoops in *ppPrev looking for one that can be
+** supplanted by pTemplate.
 **
-** IMPLEMENTATION-OF: R-24597-58655 No tests are done for terms that are
-** completely satisfied by indices.
+** Return NULL if the WhereLoop list contains an entry that can supplant
+** pTemplate, in other words if pTemplate does not belong on the list.
 **
-** Disabling a term causes that term to not be tested in the inner loop
-** of the join.  Disabling is an optimization.  When terms are satisfied
-** by indices, we disable them to prevent redundant tests in the inner
-** loop.  We would get the correct results if nothing were ever disabled,
-** but joins might run a little slower.  The trick is to disable as much
-** as we can without disabling too much.  If we disabled in (1), we'd get
-** the wrong answer.  See ticket #813.
+** If pX is a WhereLoop that pTemplate can supplant, then return the
+** link that points to pX.
+**
+** If pTemplate cannot supplant any existing element of the list but needs
+** to be added to the list, then return a pointer to the tail of the list.
 */
-static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
-  if( pTerm
-      && (pTerm->wtFlags & TERM_CODED)==0
-      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
-  ){
-    pTerm->wtFlags |= TERM_CODED;
-    if( pTerm->iParent>=0 ){
-      WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
-      if( (--pOther->nChild)==0 ){
-        disableTerm(pLevel, pOther);
-      }
+static WhereLoop **whereLoopFindLesser(
+  WhereLoop **ppPrev,
+  const WhereLoop *pTemplate
+){
+  WhereLoop *p;
+  for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
+    if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
+      /* If either the iTab or iSortIdx values for two WhereLoop are different
+      ** then those WhereLoops need to be considered separately.  Neither is
+      ** a candidate to replace the other. */
+      continue;
+    }
+    /* In the current implementation, the rSetup value is either zero
+    ** or the cost of building an automatic index (NlogN) and the NlogN
+    ** is the same for compatible WhereLoops. */
+    assert( p->rSetup==0 || pTemplate->rSetup==0 
+                 || p->rSetup==pTemplate->rSetup );
+
+    /* whereLoopAddBtree() always generates and inserts the automatic index
+    ** case first.  Hence compatible candidate WhereLoops never have a larger
+    ** rSetup. Call this SETUP-INVARIANT */
+    assert( p->rSetup>=pTemplate->rSetup );
+
+    /* Any loop using an appliation-defined index (or PRIMARY KEY or
+    ** UNIQUE constraint) with one or more == constraints is better
+    ** than an automatic index. Unless it is a skip-scan. */
+    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
+     && (pTemplate->nSkip)==0
+     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
+     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
+    ){
+      break;
+    }
+
+    /* If existing WhereLoop p is better than pTemplate, pTemplate can be
+    ** discarded.  WhereLoop p is better if:
+    **   (1)  p has no more dependencies than pTemplate, and
+    **   (2)  p has an equal or lower cost than pTemplate
+    */
+    if( (p->prereq & pTemplate->prereq)==p->prereq    /* (1)  */
+     && p->rSetup<=pTemplate->rSetup                  /* (2a) */
+     && p->rRun<=pTemplate->rRun                      /* (2b) */
+     && p->nOut<=pTemplate->nOut                      /* (2c) */
+    ){
+      return 0;  /* Discard pTemplate */
+    }
+
+    /* If pTemplate is always better than p, then cause p to be overwritten
+    ** with pTemplate.  pTemplate is better than p if:
+    **   (1)  pTemplate has no more dependences than p, and
+    **   (2)  pTemplate has an equal or lower cost than p.
+    */
+    if( (p->prereq & pTemplate->prereq)==pTemplate->prereq   /* (1)  */
+     && p->rRun>=pTemplate->rRun                             /* (2a) */
+     && p->nOut>=pTemplate->nOut                             /* (2b) */
+    ){
+      assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
+      break;   /* Cause p to be overwritten by pTemplate */
     }
   }
+  return ppPrev;
 }
 
 /*
-** Code an OP_Affinity opcode to apply the column affinity string zAff
-** to the n registers starting at base. 
+** Insert or replace a WhereLoop entry using the template supplied.
 **
-** As an optimization, SQLITE_AFF_NONE entries (which are no-ops) at the
-** beginning and end of zAff are ignored.  If all entries in zAff are
-** SQLITE_AFF_NONE, then no code gets generated.
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies.  Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template.  Otherwise a new WhereLoop is
+** added based on the template.
 **
-** This routine makes its own copy of zAff so that the caller is free
-** to modify zAff after this routine returns.
+** If pBuilder->pOrSet is not NULL then we care about only the
+** prerequisites and rRun and nOut costs of the N best loops.  That
+** information is gathered in the pBuilder->pOrSet object.  This special
+** processing mode is used only for OR clause processing.
+**
+** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
+** still might overwrite similar loops with the new template if the
+** new template is better.  Loops may be overwritten if the following 
+** conditions are met:
+**
+**    (1)  They have the same iTab.
+**    (2)  They have the same iSortIdx.
+**    (3)  The template has same or fewer dependencies than the current loop
+**    (4)  The template has the same or lower cost than the current loop
 */
-static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
-  Vdbe *v = pParse->pVdbe;
-  if( zAff==0 ){
-    assert( pParse->db->mallocFailed );
-    return;
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+  WhereLoop **ppPrev, *p;
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  sqlite3 *db = pWInfo->pParse->db;
+  int rc;
+
+  /* If pBuilder->pOrSet is defined, then only keep track of the costs
+  ** and prereqs.
+  */
+  if( pBuilder->pOrSet!=0 ){
+    if( pTemplate->nLTerm ){
+#if WHERETRACE_ENABLED
+      u16 n = pBuilder->pOrSet->n;
+      int x =
+#endif
+      whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+                                    pTemplate->nOut);
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
+        whereLoopPrint(pTemplate, pBuilder->pWC);
+      }
+#endif
+    }
+    return SQLITE_OK;
   }
-  assert( v!=0 );
 
-  /* Adjust base and n to skip over SQLITE_AFF_NONE entries at the beginning
-  ** and end of the affinity string.
+  /* Look for an existing WhereLoop to replace with pTemplate
   */
-  while( n>0 && zAff[0]==SQLITE_AFF_NONE ){
-    n--;
-    base++;
-    zAff++;
+  whereLoopAdjustCost(pWInfo->pLoops, pTemplate);
+  ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
+
+  if( ppPrev==0 ){
+    /* There already exists a WhereLoop on the list that is better
+    ** than pTemplate, so just ignore pTemplate */
+#if WHERETRACE_ENABLED /* 0x8 */
+    if( sqlite3WhereTrace & 0x8 ){
+      sqlite3DebugPrintf("   skip: ");
+      whereLoopPrint(pTemplate, pBuilder->pWC);
+    }
+#endif
+    return SQLITE_OK;  
+  }else{
+    p = *ppPrev;
   }
-  while( n>1 && zAff[n-1]==SQLITE_AFF_NONE ){
-    n--;
+
+  /* If we reach this point it means that either p[] should be overwritten
+  ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
+  ** WhereLoop and insert it.
+  */
+#if WHERETRACE_ENABLED /* 0x8 */
+  if( sqlite3WhereTrace & 0x8 ){
+    if( p!=0 ){
+      sqlite3DebugPrintf("replace: ");
+      whereLoopPrint(p, pBuilder->pWC);
+    }
+    sqlite3DebugPrintf("    add: ");
+    whereLoopPrint(pTemplate, pBuilder->pWC);
+  }
+#endif
+  if( p==0 ){
+    /* Allocate a new WhereLoop to add to the end of the list */
+    *ppPrev = p = sqlite3DbMallocRawNN(db, sizeof(WhereLoop));
+    if( p==0 ) return SQLITE_NOMEM_BKPT;
+    whereLoopInit(p);
+    p->pNextLoop = 0;
+  }else{
+    /* We will be overwriting WhereLoop p[].  But before we do, first
+    ** go through the rest of the list and delete any other entries besides
+    ** p[] that are also supplated by pTemplate */
+    WhereLoop **ppTail = &p->pNextLoop;
+    WhereLoop *pToDel;
+    while( *ppTail ){
+      ppTail = whereLoopFindLesser(ppTail, pTemplate);
+      if( ppTail==0 ) break;
+      pToDel = *ppTail;
+      if( pToDel==0 ) break;
+      *ppTail = pToDel->pNextLoop;
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(" delete: ");
+        whereLoopPrint(pToDel, pBuilder->pWC);
+      }
+#endif
+      whereLoopDelete(db, pToDel);
+    }
   }
+  rc = whereLoopXfer(db, p, pTemplate);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    Index *pIndex = p->u.btree.pIndex;
+    if( pIndex && pIndex->tnum==0 ){
+      p->u.btree.pIndex = 0;
+    }
+  }
+  return rc;
+}
 
-  /* Code the OP_Affinity opcode if there is anything left to do. */
-  if( n>0 ){
-    sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
-    sqlite3VdbeChangeP4(v, -1, zAff, n);
-    sqlite3ExprCacheAffinityChange(pParse, base, n);
+/*
+** Adjust the WhereLoop.nOut value downward to account for terms of the
+** WHERE clause that reference the loop but which are not used by an
+** index.
+*
+** For every WHERE clause term that is not used by the index
+** and which has a truth probability assigned by one of the likelihood(),
+** likely(), or unlikely() SQL functions, reduce the estimated number
+** of output rows by the probability specified.
+**
+** TUNING:  For every WHERE clause term that is not used by the index
+** and which does not have an assigned truth probability, heuristics
+** described below are used to try to estimate the truth probability.
+** TODO --> Perhaps this is something that could be improved by better
+** table statistics.
+**
+** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%
+** value corresponds to -1 in LogEst notation, so this means decrement
+** the WhereLoop.nOut field for every such WHERE clause term.
+**
+** Heuristic 2:  If there exists one or more WHERE clause terms of the
+** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
+** final output row estimate is no greater than 1/4 of the total number
+** of rows in the table.  In other words, assume that x==EXPR will filter
+** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the
+** "x" column is boolean or else -1 or 0 or 1 is a common default value
+** on the "x" column and so in that case only cap the output row estimate
+** at 1/2 instead of 1/4.
+*/
+static void whereLoopOutputAdjust(
+  WhereClause *pWC,      /* The WHERE clause */
+  WhereLoop *pLoop,      /* The loop to adjust downward */
+  LogEst nRow            /* Number of rows in the entire table */
+){
+  WhereTerm *pTerm, *pX;
+  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
+  int i, j, k;
+  LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */
+
+  assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
+    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
+    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
+    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
+    for(j=pLoop->nLTerm-1; j>=0; j--){
+      pX = pLoop->aLTerm[j];
+      if( pX==0 ) continue;
+      if( pX==pTerm ) break;
+      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
+    }
+    if( j<0 ){
+      if( pTerm->truthProb<=0 ){
+        /* If a truth probability is specified using the likelihood() hints,
+        ** then use the probability provided by the application. */
+        pLoop->nOut += pTerm->truthProb;
+      }else{
+        /* In the absence of explicit truth probabilities, use heuristics to
+        ** guess a reasonable truth probability. */
+        pLoop->nOut--;
+        if( pTerm->eOperator&(WO_EQ|WO_IS) ){
+          Expr *pRight = pTerm->pExpr->pRight;
+          testcase( pTerm->pExpr->op==TK_IS );
+          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
+            k = 10;
+          }else{
+            k = 20;
+          }
+          if( iReduce<k ) iReduce = k;
+        }
+      }
+    }
   }
+  if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
 }
 
+/*
+** Adjust the cost C by the costMult facter T.  This only occurs if
+** compiled with -DSQLITE_ENABLE_COSTMULT
+*/
+#ifdef SQLITE_ENABLE_COSTMULT
+# define ApplyCostMultiplier(C,T)  C += T
+#else
+# define ApplyCostMultiplier(C,T)
+#endif
 
 /*
-** Generate code for a single equality term of the WHERE clause.  An equality
-** term can be either X=expr or X IN (...).   pTerm is the term to be 
-** coded.
+** We have so far matched pBuilder->pNew->u.btree.nEq terms of the 
+** index pIndex. Try to match one more.
 **
-** The current value for the constraint is left in register iReg.
+** When this function is called, pBuilder->pNew->nOut contains the 
+** number of rows expected to be visited by filtering using the nEq 
+** terms only. If it is modified, this value is restored before this 
+** function returns.
 **
-** For a constraint of the form X=expr, the expression is evaluated and its
-** result is left on the stack.  For constraints of the form X IN (...)
-** this routine sets up a loop that will iterate over all values of X.
-*/
-static int codeEqualityTerm(
-  Parse *pParse,      /* The parsing context */
-  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
-  WhereLevel *pLevel, /* When level of the FROM clause we are working on */
-  int iTarget         /* Attempt to leave results in this register */
-){
-  Expr *pX = pTerm->pExpr;
-  Vdbe *v = pParse->pVdbe;
-  int iReg;                  /* Register holding results */
+** If pProbe->tnum==0, that means pIndex is a fake index used for the
+** INTEGER PRIMARY KEY.
+*/
+static int whereLoopAddBtreeIndex(
+  WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */
+  struct SrcList_item *pSrc,      /* FROM clause term being analyzed */
+  Index *pProbe,                  /* An index on pSrc */
+  LogEst nInMul                   /* log(Number of iterations due to IN) */
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */
+  Parse *pParse = pWInfo->pParse;        /* Parsing context */
+  sqlite3 *db = pParse->db;       /* Database connection malloc context */
+  WhereLoop *pNew;                /* Template WhereLoop under construction */
+  WhereTerm *pTerm;               /* A WhereTerm under consideration */
+  int opMask;                     /* Valid operators for constraints */
+  WhereScan scan;                 /* Iterator for WHERE terms */
+  Bitmask saved_prereq;           /* Original value of pNew->prereq */
+  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
+  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
+  u16 saved_nSkip;                /* Original value of pNew->nSkip */
+  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
+  LogEst saved_nOut;              /* Original value of pNew->nOut */
+  int rc = SQLITE_OK;             /* Return code */
+  LogEst rSize;                   /* Number of rows in the table */
+  LogEst rLogSize;                /* Logarithm of table size */
+  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
 
-  assert( iTarget>0 );
-  if( pX->op==TK_EQ ){
-    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
-  }else if( pX->op==TK_ISNULL ){
-    iReg = iTarget;
-    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
-#ifndef SQLITE_OMIT_SUBQUERY
+  pNew = pBuilder->pNew;
+  if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
+
+  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
+  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
+    opMask = WO_LT|WO_LE;
   }else{
-    int eType;
-    int iTab;
-    struct InLoop *pIn;
+    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
+  }
+  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+
+  assert( pNew->u.btree.nEq<pProbe->nColumn );
+
+  saved_nEq = pNew->u.btree.nEq;
+  saved_nSkip = pNew->nSkip;
+  saved_nLTerm = pNew->nLTerm;
+  saved_wsFlags = pNew->wsFlags;
+  saved_prereq = pNew->prereq;
+  saved_nOut = pNew->nOut;
+  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
+                        opMask, pProbe);
+  pNew->rSetup = 0;
+  rSize = pProbe->aiRowLogEst[0];
+  rLogSize = estLog(rSize);
+  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
+    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
+    LogEst rCostIdx;
+    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
+    int nIn = 0;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    int nRecValid = pBuilder->nRecValid;
+#endif
+    if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
+     && indexColumnNotNull(pProbe, saved_nEq)
+    ){
+      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
+    }
+    if( pTerm->prereqRight & pNew->maskSelf ) continue;
 
-    assert( pX->op==TK_IN );
-    iReg = iTarget;
-    eType = sqlite3FindInIndex(pParse, pX, 0);
-    iTab = pX->iTable;
-    sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
-    assert( pLevel->plan.wsFlags & WHERE_IN_ABLE );
-    if( pLevel->u.in.nIn==0 ){
-      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+    /* Do not allow the upper bound of a LIKE optimization range constraint
+    ** to mix with a lower range bound from some other source */
+    if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue;
+
+    /* Do not allow IS constraints from the WHERE clause to be used by the
+    ** right table of a LEFT JOIN.  Only constraints in the ON clause are
+    ** allowed */
+    if( (pSrc->fg.jointype & JT_LEFT)!=0
+     && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+     && (eOp & (WO_IS|WO_ISNULL))!=0
+    ){
+      testcase( eOp & WO_IS );
+      testcase( eOp & WO_ISNULL );
+      continue;
     }
-    pLevel->u.in.nIn++;
-    pLevel->u.in.aInLoop =
-       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
-                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
-    pIn = pLevel->u.in.aInLoop;
-    if( pIn ){
-      pIn += pLevel->u.in.nIn - 1;
-      pIn->iCur = iTab;
-      if( eType==IN_INDEX_ROWID ){
-        pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+
+    pNew->wsFlags = saved_wsFlags;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nLTerm = saved_nLTerm;
+    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+    pNew->aLTerm[pNew->nLTerm++] = pTerm;
+    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
+
+    assert( nInMul==0
+        || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 
+        || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 
+        || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 
+    );
+
+    if( eOp & WO_IN ){
+      Expr *pExpr = pTerm->pExpr;
+      pNew->wsFlags |= WHERE_COLUMN_IN;
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
+        nIn = 46;  assert( 46==sqlite3LogEst(25) );
+      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
+        /* "x IN (value, value, ...)" */
+        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
+      }
+      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
+                        ** changes "x IN (?)" into "x=?". */
+
+    }else if( eOp & (WO_EQ|WO_IS) ){
+      int iCol = pProbe->aiColumn[saved_nEq];
+      pNew->wsFlags |= WHERE_COLUMN_EQ;
+      assert( saved_nEq==pNew->u.btree.nEq );
+      if( iCol==XN_ROWID 
+       || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
+      ){
+        if( iCol>=0 && pProbe->uniqNotNull==0 ){
+          pNew->wsFlags |= WHERE_UNQ_WANTED;
+        }else{
+          pNew->wsFlags |= WHERE_ONEROW;
+        }
+      }
+    }else if( eOp & WO_ISNULL ){
+      pNew->wsFlags |= WHERE_COLUMN_NULL;
+    }else if( eOp & (WO_GT|WO_GE) ){
+      testcase( eOp & WO_GT );
+      testcase( eOp & WO_GE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
+      pBtm = pTerm;
+      pTop = 0;
+      if( pTerm->wtFlags & TERM_LIKEOPT ){
+        /* Range contraints that come from the LIKE optimization are
+        ** always used in pairs. */
+        pTop = &pTerm[1];
+        assert( (pTop-(pTerm->pWC->a))<pTerm->pWC->nTerm );
+        assert( pTop->wtFlags & TERM_LIKEOPT );
+        assert( pTop->eOperator==WO_LT );
+        if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+        pNew->aLTerm[pNew->nLTerm++] = pTop;
+        pNew->wsFlags |= WHERE_TOP_LIMIT;
+      }
+    }else{
+      assert( eOp & (WO_LT|WO_LE) );
+      testcase( eOp & WO_LT );
+      testcase( eOp & WO_LE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
+      pTop = pTerm;
+      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
+                     pNew->aLTerm[pNew->nLTerm-2] : 0;
+    }
+
+    /* At this point pNew->nOut is set to the number of rows expected to
+    ** be visited by the index scan before considering term pTerm, or the
+    ** values of nIn and nInMul. In other words, assuming that all 
+    ** "x IN(...)" terms are replaced with "x = ?". This block updates
+    ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul).  */
+    assert( pNew->nOut==saved_nOut );
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4
+      ** data, using some other estimate.  */
+      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
+    }else{
+      int nEq = ++pNew->u.btree.nEq;
+      assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );
+
+      assert( pNew->nOut==saved_nOut );
+      if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
+        assert( (eOp & WO_IN) || nIn==0 );
+        testcase( eOp & WO_IN );
+        pNew->nOut += pTerm->truthProb;
+        pNew->nOut -= nIn;
       }else{
-        pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+        tRowcnt nOut = 0;
+        if( nInMul==0 
+         && pProbe->nSample 
+         && pNew->u.btree.nEq<=pProbe->nSampleCol
+         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
+        ){
+          Expr *pExpr = pTerm->pExpr;
+          if( (eOp & (WO_EQ|WO_ISNULL|WO_IS))!=0 ){
+            testcase( eOp & WO_EQ );
+            testcase( eOp & WO_IS );
+            testcase( eOp & WO_ISNULL );
+            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
+          }else{
+            rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
+          }
+          if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+          if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */
+          if( nOut ){
+            pNew->nOut = sqlite3LogEst(nOut);
+            if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;
+            pNew->nOut -= nIn;
+          }
+        }
+        if( nOut==0 )
+#endif
+        {
+          pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);
+          if( eOp & WO_ISNULL ){
+            /* TUNING: If there is no likelihood() value, assume that a 
+            ** "col IS NULL" expression matches twice as many rows 
+            ** as (col=?). */
+            pNew->nOut += 10;
+          }
+        }
       }
-      sqlite3VdbeAddOp1(v, OP_IsNull, iReg);
+    }
+
+    /* Set rCostIdx to the cost of visiting selected rows in index. Add
+    ** it to pNew->rRun, which is currently set to the cost of the index
+    ** seek only. Then, if this is a non-covering index, add the cost of
+    ** visiting the rows in the main table.  */
+    rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
+    pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
+    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+      pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
+    }
+    ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
+
+    nOutUnadjusted = pNew->nOut;
+    pNew->rRun += nInMul + nIn;
+    pNew->nOut += nInMul + nIn;
+    whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
+    rc = whereLoopInsert(pBuilder, pNew);
+
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      pNew->nOut = saved_nOut;
     }else{
-      pLevel->u.in.nIn = 0;
+      pNew->nOut = nOutUnadjusted;
+    }
+
+    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
+     && pNew->u.btree.nEq<pProbe->nColumn
+    ){
+      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
     }
+    pNew->nOut = saved_nOut;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    pBuilder->nRecValid = nRecValid;
 #endif
   }
-  disableTerm(pLevel, pTerm);
-  return iReg;
+  pNew->prereq = saved_prereq;
+  pNew->u.btree.nEq = saved_nEq;
+  pNew->nSkip = saved_nSkip;
+  pNew->wsFlags = saved_wsFlags;
+  pNew->nOut = saved_nOut;
+  pNew->nLTerm = saved_nLTerm;
+
+  /* Consider using a skip-scan if there are no WHERE clause constraints
+  ** available for the left-most terms of the index, and if the average
+  ** number of repeats in the left-most terms is at least 18. 
+  **
+  ** The magic number 18 is selected on the basis that scanning 17 rows
+  ** is almost always quicker than an index seek (even though if the index
+  ** contains fewer than 2^17 rows we assume otherwise in other parts of
+  ** the code). And, even if it is not, it should not be too much slower. 
+  ** On the other hand, the extra seeks could end up being significantly
+  ** more expensive.  */
+  assert( 42==sqlite3LogEst(18) );
+  if( saved_nEq==saved_nSkip
+   && saved_nEq+1<pProbe->nKeyCol
+   && pProbe->noSkipScan==0
+   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
+   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
+  ){
+    LogEst nIter;
+    pNew->u.btree.nEq++;
+    pNew->nSkip++;
+    pNew->aLTerm[pNew->nLTerm++] = 0;
+    pNew->wsFlags |= WHERE_SKIPSCAN;
+    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
+    pNew->nOut -= nIter;
+    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
+    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
+    nIter += 5;
+    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
+    pNew->nOut = saved_nOut;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nSkip = saved_nSkip;
+    pNew->wsFlags = saved_wsFlags;
+  }
+
+  return rc;
 }
 
 /*
-** Generate code that will evaluate all == and IN constraints for an
-** index.
-**
-** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
-** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
-** The index has as many as three equality constraints, but in this
-** example, the third "c" value is an inequality.  So only two 
-** constraints are coded.  This routine will generate code to evaluate
-** a==5 and b IN (1,2,3).  The current values for a and b will be stored
-** in consecutive registers and the index of the first register is returned.
-**
-** In the example above nEq==2.  But this subroutine works for any value
-** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
-** The only thing it does is allocate the pLevel->iMem memory cell and
-** compute the affinity string.
-**
-** This routine always allocates at least one memory cell and returns
-** the index of that memory cell. The code that
-** calls this routine will use that memory cell to store the termination
-** key value of the loop.  If one or more IN operators appear, then
-** this routine allocates an additional nEq memory cells for internal
-** use.
+** Return True if it is possible that pIndex might be useful in
+** implementing the ORDER BY clause in pBuilder.
 **
-** Before returning, *pzAff is set to point to a buffer containing a
-** copy of the column affinity string of the index allocated using
-** sqlite3DbMalloc(). Except, entries in the copy of the string associated
-** with equality constraints that use NONE affinity are set to
-** SQLITE_AFF_NONE. This is to deal with SQL such as the following:
-**
-**   CREATE TABLE t1(a TEXT PRIMARY KEY, b);
-**   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
-**
-** In the example above, the index on t1(a) has TEXT affinity. But since
-** the right hand side of the equality constraint (t2.b) has NONE affinity,
-** no conversion should be attempted before using a t2.b value as part of
-** a key to search the index. Hence the first byte in the returned affinity
-** string in this example would be set to SQLITE_AFF_NONE.
+** Return False if pBuilder does not contain an ORDER BY clause or
+** if there is no way for pIndex to be useful in implementing that
+** ORDER BY clause.
 */
-static int codeAllEqualityTerms(
-  Parse *pParse,        /* Parsing context */
-  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
-  WhereClause *pWC,     /* The WHERE clause */
-  Bitmask notReady,     /* Which parts of FROM have not yet been coded */
-  int nExtraReg,        /* Number of extra registers to allocate */
-  char **pzAff          /* OUT: Set to point to affinity string */
+static int indexMightHelpWithOrderBy(
+  WhereLoopBuilder *pBuilder,
+  Index *pIndex,
+  int iCursor
 ){
-  int nEq = pLevel->plan.nEq;   /* The number of == or IN constraints to code */
-  Vdbe *v = pParse->pVdbe;      /* The vm under construction */
-  Index *pIdx;                  /* The index being used for this loop */
-  int iCur = pLevel->iTabCur;   /* The cursor of the table */
-  WhereTerm *pTerm;             /* A single constraint term */
-  int j;                        /* Loop counter */
-  int regBase;                  /* Base register */
-  int nReg;                     /* Number of registers to allocate */
-  char *zAff;                   /* Affinity string to return */
-
-  /* This module is only called on query plans that use an index. */
-  assert( pLevel->plan.wsFlags & WHERE_INDEXED );
-  pIdx = pLevel->plan.u.pIdx;
-
-  /* Figure out how many memory cells we will need then allocate them.
-  */
-  regBase = pParse->nMem + 1;
-  nReg = pLevel->plan.nEq + nExtraReg;
-  pParse->nMem += nReg;
+  ExprList *pOB;
+  ExprList *aColExpr;
+  int ii, jj;
 
-  zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
-  if( !zAff ){
-    pParse->db->mallocFailed = 1;
-  }
-
-  /* Evaluate the equality constraints
-  */
-  assert( pIdx->nColumn>=nEq );
-  for(j=0; j<nEq; j++){
-    int r1;
-    int k = pIdx->aiColumn[j];
-    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx);
-    if( NEVER(pTerm==0) ) break;
-    /* The following true for indices with redundant columns. 
-    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
-    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
-    if( r1!=regBase+j ){
-      if( nReg==1 ){
-        sqlite3ReleaseTempReg(pParse, regBase);
-        regBase = r1;
-      }else{
-        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+  if( pIndex->bUnordered ) return 0;
+  if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
+  for(ii=0; ii<pOB->nExpr; ii++){
+    Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
+    if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
+      if( pExpr->iColumn<0 ) return 1;
+      for(jj=0; jj<pIndex->nKeyCol; jj++){
+        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
       }
-    }
-    testcase( pTerm->eOperator & WO_ISNULL );
-    testcase( pTerm->eOperator & WO_IN );
-    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
-      Expr *pRight = pTerm->pExpr->pRight;
-      sqlite3ExprCodeIsNullJump(v, pRight, regBase+j, pLevel->addrBrk);
-      if( zAff ){
-        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){
-          zAff[j] = SQLITE_AFF_NONE;
-        }
-        if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
-          zAff[j] = SQLITE_AFF_NONE;
+    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
+      for(jj=0; jj<pIndex->nKeyCol; jj++){
+        if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
+        if( sqlite3ExprCompare(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
+          return 1;
         }
       }
     }
   }
-  *pzAff = zAff;
-  return regBase;
+  return 0;
 }
 
-#ifndef SQLITE_OMIT_EXPLAIN
 /*
-** This routine is a helper for explainIndexRange() below
-**
-** pStr holds the text of an expression that we are building up one term
-** at a time.  This routine adds a new term to the end of the expression.
-** Terms are separated by AND so add the "AND" text for second and subsequent
-** terms only.
+** Return a bitmask where 1s indicate that the corresponding column of
+** the table is used by an index.  Only the first 63 columns are considered.
 */
-static void explainAppendTerm(
-  StrAccum *pStr,             /* The text expression being built */
-  int iTerm,                  /* Index of this term.  First is zero */
-  const char *zColumn,        /* Name of the column */
-  const char *zOp             /* Name of the operator */
-){
-  if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
-  sqlite3StrAccumAppend(pStr, zColumn, -1);
-  sqlite3StrAccumAppend(pStr, zOp, 1);
-  sqlite3StrAccumAppend(pStr, "?", 1);
+static Bitmask columnsInIndex(Index *pIdx){
+  Bitmask m = 0;
+  int j;
+  for(j=pIdx->nColumn-1; j>=0; j--){
+    int x = pIdx->aiColumn[j];
+    if( x>=0 ){
+      testcase( x==BMS-1 );
+      testcase( x==BMS-2 );
+      if( x<BMS-1 ) m |= MASKBIT(x);
+    }
+  }
+  return m;
+}
+
+/* Check to see if a partial index with pPartIndexWhere can be used
+** in the current query.  Return true if it can be and false if not.
+*/
+static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
+  int i;
+  WhereTerm *pTerm;
+  while( pWhere->op==TK_AND ){
+    if( !whereUsablePartialIndex(iTab,pWC,pWhere->pLeft) ) return 0;
+    pWhere = pWhere->pRight;
+  }
+  for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    Expr *pExpr = pTerm->pExpr;
+    if( sqlite3ExprImpliesExpr(pExpr, pWhere, iTab) 
+     && (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)
+    ){
+      return 1;
+    }
+  }
+  return 0;
 }
 
 /*
-** Argument pLevel describes a strategy for scanning table pTab. This 
-** function returns a pointer to a string buffer containing a description
-** of the subset of table rows scanned by the strategy in the form of an
-** SQL expression. Or, if all rows are scanned, NULL is returned.
+** Add all WhereLoop objects for a single table of the join where the table
+** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be
+** a b-tree table, not a virtual table.
 **
-** For example, if the query:
+** The costs (WhereLoop.rRun) of the b-tree loops added by this function
+** are calculated as follows:
 **
-**   SELECT * FROM t1 WHERE a=1 AND b>2;
+** For a full scan, assuming the table (or index) contains nRow rows:
 **
-** is run and there is an index on (a, b), then this function returns a
-** string similar to:
+**     cost = nRow * 3.0                    // full-table scan
+**     cost = nRow * K                      // scan of covering index
+**     cost = nRow * (K+3.0)                // scan of non-covering index
 **
-**   "a=? AND b>?"
+** where K is a value between 1.1 and 3.0 set based on the relative 
+** estimated average size of the index and table records.
+**
+** For an index scan, where nVisit is the number of index rows visited
+** by the scan, and nSeek is the number of seek operations required on 
+** the index b-tree:
+**
+**     cost = nSeek * (log(nRow) + K * nVisit)          // covering index
+**     cost = nSeek * (log(nRow) + (K+3.0) * nVisit)    // non-covering index
 **
-** The returned pointer points to memory obtained from sqlite3DbMalloc().
-** It is the responsibility of the caller to free the buffer when it is
-** no longer required.
+** Normally, nSeek is 1. nSeek values greater than 1 come about if the 
+** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when 
+** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.
+**
+** The estimated values (nRow, nVisit, nSeek) often contain a large amount
+** of uncertainty.  For this reason, scoring is designed to pick plans that
+** "do the least harm" if the estimates are inaccurate.  For example, a
+** log(nRow) factor is omitted from a non-covering index scan in order to
+** bias the scoring in favor of using an index, since the worst-case
+** performance of using an index is far better than the worst-case performance
+** of a full table scan.
 */
-static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){
-  WherePlan *pPlan = &pLevel->plan;
-  Index *pIndex = pPlan->u.pIdx;
-  int nEq = pPlan->nEq;
-  int i, j;
-  Column *aCol = pTab->aCol;
-  int *aiColumn = pIndex->aiColumn;
-  StrAccum txt;
-
-  if( nEq==0 && (pPlan->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){
-    return 0;
-  }
-  sqlite3StrAccumInit(&txt, 0, 0, SQLITE_MAX_LENGTH);
-  txt.db = db;
-  sqlite3StrAccumAppend(&txt, " (", 2);
-  for(i=0; i<nEq; i++){
-    explainAppendTerm(&txt, i, aCol[aiColumn[i]].zName, "=");
+static int whereLoopAddBtree(
+  WhereLoopBuilder *pBuilder, /* WHERE clause information */
+  Bitmask mPrereq             /* Extra prerequesites for using this table */
+){
+  WhereInfo *pWInfo;          /* WHERE analysis context */
+  Index *pProbe;              /* An index we are evaluating */
+  Index sPk;                  /* A fake index object for the primary key */
+  LogEst aiRowEstPk[2];       /* The aiRowLogEst[] value for the sPk index */
+  i16 aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
+  SrcList *pTabList;          /* The FROM clause */
+  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
+  WhereLoop *pNew;            /* Template WhereLoop object */
+  int rc = SQLITE_OK;         /* Return code */
+  int iSortIdx = 1;           /* Index number */
+  int b;                      /* A boolean value */
+  LogEst rSize;               /* number of rows in the table */
+  LogEst rLogSize;            /* Logarithm of the number of rows in the table */
+  WhereClause *pWC;           /* The parsed WHERE clause */
+  Table *pTab;                /* Table being queried */
+  
+  pNew = pBuilder->pNew;
+  pWInfo = pBuilder->pWInfo;
+  pTabList = pWInfo->pTabList;
+  pSrc = pTabList->a + pNew->iTab;
+  pTab = pSrc->pTab;
+  pWC = pBuilder->pWC;
+  assert( !IsVirtual(pSrc->pTab) );
+
+  if( pSrc->pIBIndex ){
+    /* An INDEXED BY clause specifies a particular index to use */
+    pProbe = pSrc->pIBIndex;
+  }else if( !HasRowid(pTab) ){
+    pProbe = pTab->pIndex;
+  }else{
+    /* There is no INDEXED BY clause.  Create a fake Index object in local
+    ** variable sPk to represent the rowid primary key index.  Make this
+    ** fake index the first in a chain of Index objects with all of the real
+    ** indices to follow */
+    Index *pFirst;                  /* First of real indices on the table */
+    memset(&sPk, 0, sizeof(Index));
+    sPk.nKeyCol = 1;
+    sPk.nColumn = 1;
+    sPk.aiColumn = &aiColumnPk;
+    sPk.aiRowLogEst = aiRowEstPk;
+    sPk.onError = OE_Replace;
+    sPk.pTable = pTab;
+    sPk.szIdxRow = pTab->szTabRow;
+    aiRowEstPk[0] = pTab->nRowLogEst;
+    aiRowEstPk[1] = 0;
+    pFirst = pSrc->pTab->pIndex;
+    if( pSrc->fg.notIndexed==0 ){
+      /* The real indices of the table are only considered if the
+      ** NOT INDEXED qualifier is omitted from the FROM clause */
+      sPk.pNext = pFirst;
+    }
+    pProbe = &sPk;
   }
+  rSize = pTab->nRowLogEst;
+  rLogSize = estLog(rSize);
 
-  j = i;
-  if( pPlan->wsFlags&WHERE_BTM_LIMIT ){
-    explainAppendTerm(&txt, i++, aCol[aiColumn[j]].zName, ">");
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+  /* Automatic indexes */
+  if( !pBuilder->pOrSet      /* Not part of an OR optimization */
+   && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
+   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
+   && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */
+   && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */
+   && HasRowid(pTab)         /* Not WITHOUT ROWID table. (FIXME: Why not?) */
+   && !pSrc->fg.isCorrelated /* Not a correlated subquery */
+   && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */
+  ){
+    /* Generate auto-index WhereLoops */
+    WhereTerm *pTerm;
+    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
+    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
+      if( pTerm->prereqRight & pNew->maskSelf ) continue;
+      if( termCanDriveIndex(pTerm, pSrc, 0) ){
+        pNew->u.btree.nEq = 1;
+        pNew->nSkip = 0;
+        pNew->u.btree.pIndex = 0;
+        pNew->nLTerm = 1;
+        pNew->aLTerm[0] = pTerm;
+        /* TUNING: One-time cost for computing the automatic index is
+        ** estimated to be X*N*log2(N) where N is the number of rows in
+        ** the table being indexed and where X is 7 (LogEst=28) for normal
+        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
+        ** of X is smaller for views and subqueries so that the query planner
+        ** will be more aggressive about generating automatic indexes for
+        ** those objects, since there is no opportunity to add schema
+        ** indexes on subqueries and views. */
+        pNew->rSetup = rLogSize + rSize + 4;
+        if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){
+          pNew->rSetup += 24;
+        }
+        ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
+        if( pNew->rSetup<0 ) pNew->rSetup = 0;
+        /* TUNING: Each index lookup yields 20 rows in the table.  This
+        ** is more than the usual guess of 10 rows, since we have no way
+        ** of knowing how selective the index will ultimately be.  It would
+        ** not be unreasonable to make this value much larger. */
+        pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );
+        pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
+        pNew->wsFlags = WHERE_AUTO_INDEX;
+        pNew->prereq = mPrereq | pTerm->prereqRight;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+    }
   }
-  if( pPlan->wsFlags&WHERE_TOP_LIMIT ){
-    explainAppendTerm(&txt, i, aCol[aiColumn[j]].zName, "<");
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+  /* Loop over all indices
+  */
+  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
+    if( pProbe->pPartIdxWhere!=0
+     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
+      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
+      continue;  /* Partial index inappropriate for this query */
+    }
+    rSize = pProbe->aiRowLogEst[0];
+    pNew->u.btree.nEq = 0;
+    pNew->nSkip = 0;
+    pNew->nLTerm = 0;
+    pNew->iSortIdx = 0;
+    pNew->rSetup = 0;
+    pNew->prereq = mPrereq;
+    pNew->nOut = rSize;
+    pNew->u.btree.pIndex = pProbe;
+    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
+    if( pProbe->tnum<=0 ){
+      /* Integer primary key index */
+      pNew->wsFlags = WHERE_IPK;
+
+      /* Full table scan */
+      pNew->iSortIdx = b ? iSortIdx : 0;
+      /* TUNING: Cost of full table scan is (N*3.0). */
+      pNew->rRun = rSize + 16;
+      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+      whereLoopOutputAdjust(pWC, pNew, rSize);
+      rc = whereLoopInsert(pBuilder, pNew);
+      pNew->nOut = rSize;
+      if( rc ) break;
+    }else{
+      Bitmask m;
+      if( pProbe->isCovering ){
+        pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
+        m = 0;
+      }else{
+        m = pSrc->colUsed & ~columnsInIndex(pProbe);
+        pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
+      }
+
+      /* Full scan via index */
+      if( b
+       || !HasRowid(pTab)
+       || pProbe->pPartIdxWhere!=0
+       || ( m==0
+         && pProbe->bUnordered==0
+         && (pProbe->szIdxRow<pTab->szTabRow)
+         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+         && sqlite3GlobalConfig.bUseCis
+         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+          )
+      ){
+        pNew->iSortIdx = b ? iSortIdx : 0;
+
+        /* The cost of visiting the index rows is N*K, where K is
+        ** between 1.1 and 3.0, depending on the relative sizes of the
+        ** index and table rows. */
+        pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
+        if( m!=0 ){
+          /* If this is a non-covering index scan, add in the cost of
+          ** doing table lookups.  The cost will be 3x the number of
+          ** lookups.  Take into account WHERE clause terms that can be
+          ** satisfied using just the index, and that do not require a
+          ** table lookup. */
+          LogEst nLookup = rSize + 16;  /* Base cost:  N*3 */
+          int ii;
+          int iCur = pSrc->iCursor;
+          WhereClause *pWC2 = &pWInfo->sWC;
+          for(ii=0; ii<pWC2->nTerm; ii++){
+            WhereTerm *pTerm = &pWC2->a[ii];
+            if( !sqlite3ExprCoveredByIndex(pTerm->pExpr, iCur, pProbe) ){
+              break;
+            }
+            /* pTerm can be evaluated using just the index.  So reduce
+            ** the expected number of table lookups accordingly */
+            if( pTerm->truthProb<=0 ){
+              nLookup += pTerm->truthProb;
+            }else{
+              nLookup--;
+              if( pTerm->eOperator & (WO_EQ|WO_IS) ) nLookup -= 19;
+            }
+          }
+          
+          pNew->rRun = sqlite3LogEstAdd(pNew->rRun, nLookup);
+        }
+        ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+        whereLoopOutputAdjust(pWC, pNew, rSize);
+        rc = whereLoopInsert(pBuilder, pNew);
+        pNew->nOut = rSize;
+        if( rc ) break;
+      }
+    }
+
+    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    sqlite3Stat4ProbeFree(pBuilder->pRec);
+    pBuilder->nRecValid = 0;
+    pBuilder->pRec = 0;
+#endif
+
+    /* If there was an INDEXED BY clause, then only that one index is
+    ** considered. */
+    if( pSrc->pIBIndex ) break;
   }
-  sqlite3StrAccumAppend(&txt, ")", 1);
-  return sqlite3StrAccumFinish(&txt);
+  return rc;
 }
 
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
 /*
-** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
-** command. If the query being compiled is an EXPLAIN QUERY PLAN, a single
-** record is added to the output to describe the table scan strategy in 
-** pLevel.
+** Argument pIdxInfo is already populated with all constraints that may
+** be used by the virtual table identified by pBuilder->pNew->iTab. This
+** function marks a subset of those constraints usable, invokes the
+** xBestIndex method and adds the returned plan to pBuilder.
+**
+** A constraint is marked usable if:
+**
+**   * Argument mUsable indicates that its prerequisites are available, and
+**
+**   * It is not one of the operators specified in the mExclude mask passed
+**     as the fourth argument (which in practice is either WO_IN or 0).
+**
+** Argument mPrereq is a mask of tables that must be scanned before the
+** virtual table in question. These are added to the plans prerequisites
+** before it is added to pBuilder.
+**
+** Output parameter *pbIn is set to true if the plan added to pBuilder
+** uses one or more WO_IN terms, or false otherwise.
 */
-static void explainOneScan(
-  Parse *pParse,                  /* Parse context */
-  SrcList *pTabList,              /* Table list this loop refers to */
-  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
-  int iLevel,                     /* Value for "level" column of output */
-  int iFrom,                      /* Value for "from" column of output */
-  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+static int whereLoopAddVirtualOne(
+  WhereLoopBuilder *pBuilder,
+  Bitmask mPrereq,                /* Mask of tables that must be used. */
+  Bitmask mUsable,                /* Mask of usable tables */
+  u16 mExclude,                   /* Exclude terms using these operators */
+  sqlite3_index_info *pIdxInfo,   /* Populated object for xBestIndex */
+  int *pbIn                       /* OUT: True if plan uses an IN(...) op */
 ){
-  if( pParse->explain==2 ){
-    u32 flags = pLevel->plan.wsFlags;
-    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
-    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
-    sqlite3 *db = pParse->db;     /* Database handle */
-    char *zMsg;                   /* Text to add to EQP output */
-    sqlite3_int64 nRow;           /* Expected number of rows visited by scan */
-    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
-    int isSearch;                 /* True for a SEARCH. False for SCAN. */
-
-    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return;
+  WhereClause *pWC = pBuilder->pWC;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;
+  int i;
+  int mxTerm;
+  int rc = SQLITE_OK;
+  WhereLoop *pNew = pBuilder->pNew;
+  Parse *pParse = pBuilder->pWInfo->pParse;
+  struct SrcList_item *pSrc = &pBuilder->pWInfo->pTabList->a[pNew->iTab];
+  int nConstraint = pIdxInfo->nConstraint;
 
-    isSearch = (pLevel->plan.nEq>0)
-             || (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
-             || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+  assert( (mUsable & mPrereq)==mPrereq );
+  *pbIn = 0;
+  pNew->prereq = mPrereq;
 
-    zMsg = sqlite3MPrintf(db, "%s", isSearch?"SEARCH":"SCAN");
-    if( pItem->pSelect ){
-      zMsg = sqlite3MAppendf(db, zMsg, "%s SUBQUERY %d", zMsg,pItem->iSelectId);
-    }else{
-      zMsg = sqlite3MAppendf(db, zMsg, "%s TABLE %s", zMsg, pItem->zName);
+  /* Set the usable flag on the subset of constraints identified by 
+  ** arguments mUsable and mExclude. */
+  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+  for(i=0; i<nConstraint; i++, pIdxCons++){
+    WhereTerm *pTerm = &pWC->a[pIdxCons->iTermOffset];
+    pIdxCons->usable = 0;
+    if( (pTerm->prereqRight & mUsable)==pTerm->prereqRight 
+     && (pTerm->eOperator & mExclude)==0
+    ){
+      pIdxCons->usable = 1;
     }
+  }
 
-    if( pItem->zAlias ){
-      zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias);
-    }
-    if( (flags & WHERE_INDEXED)!=0 ){
-      char *zWhere = explainIndexRange(db, pLevel, pItem->pTab);
-      zMsg = sqlite3MAppendf(db, zMsg, "%s USING %s%sINDEX%s%s%s", zMsg, 
-          ((flags & WHERE_TEMP_INDEX)?"AUTOMATIC ":""),
-          ((flags & WHERE_IDX_ONLY)?"COVERING ":""),
-          ((flags & WHERE_TEMP_INDEX)?"":" "),
-          ((flags & WHERE_TEMP_INDEX)?"": pLevel->plan.u.pIdx->zName),
-          zWhere
-      );
-      sqlite3DbFree(db, zWhere);
-    }else if( flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
-      zMsg = sqlite3MAppendf(db, zMsg, "%s USING INTEGER PRIMARY KEY", zMsg);
+  /* Initialize the output fields of the sqlite3_index_info structure */
+  memset(pUsage, 0, sizeof(pUsage[0])*nConstraint);
+  assert( pIdxInfo->needToFreeIdxStr==0 );
+  pIdxInfo->idxStr = 0;
+  pIdxInfo->idxNum = 0;
+  pIdxInfo->orderByConsumed = 0;
+  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
+  pIdxInfo->estimatedRows = 25;
+  pIdxInfo->idxFlags = 0;
+  pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;
 
-      if( flags&WHERE_ROWID_EQ ){
-        zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid=?)", zMsg);
-      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
-        zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>? AND rowid<?)", zMsg);
-      }else if( flags&WHERE_BTM_LIMIT ){
-        zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>?)", zMsg);
-      }else if( flags&WHERE_TOP_LIMIT ){
-        zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid<?)", zMsg);
+  /* Invoke the virtual table xBestIndex() method */
+  rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);
+  if( rc ) return rc;
+
+  mxTerm = -1;
+  assert( pNew->nLSlot>=nConstraint );
+  for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
+  pNew->u.vtab.omitMask = 0;
+  pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+  for(i=0; i<nConstraint; i++, pIdxCons++){
+    int iTerm;
+    if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
+      WhereTerm *pTerm;
+      int j = pIdxCons->iTermOffset;
+      if( iTerm>=nConstraint
+       || j<0
+       || j>=pWC->nTerm
+       || pNew->aLTerm[iTerm]!=0
+       || pIdxCons->usable==0
+      ){
+        rc = SQLITE_ERROR;
+        sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);
+        return rc;
       }
-    }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
-      sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
-      zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg,
-                  pVtabIdx->idxNum, pVtabIdx->idxStr);
-    }
-#endif
-    if( wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) ){
-      testcase( wctrlFlags & WHERE_ORDERBY_MIN );
-      nRow = 1;
-    }else{
-      nRow = (sqlite3_int64)pLevel->plan.nRow;
-    }
-    zMsg = sqlite3MAppendf(db, zMsg, "%s (~%lld rows)", zMsg, nRow);
-    sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC);
+      testcase( iTerm==nConstraint-1 );
+      testcase( j==0 );
+      testcase( j==pWC->nTerm-1 );
+      pTerm = &pWC->a[j];
+      pNew->prereq |= pTerm->prereqRight;
+      assert( iTerm<pNew->nLSlot );
+      pNew->aLTerm[iTerm] = pTerm;
+      if( iTerm>mxTerm ) mxTerm = iTerm;
+      testcase( iTerm==15 );
+      testcase( iTerm==16 );
+      if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm;
+      if( (pTerm->eOperator & WO_IN)!=0 ){
+        /* A virtual table that is constrained by an IN clause may not
+        ** consume the ORDER BY clause because (1) the order of IN terms
+        ** is not necessarily related to the order of output terms and
+        ** (2) Multiple outputs from a single IN value will not merge
+        ** together.  */
+        pIdxInfo->orderByConsumed = 0;
+        pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
+        *pbIn = 1; assert( (mExclude & WO_IN)==0 );
+      }
+    }
+  }
+
+  pNew->nLTerm = mxTerm+1;
+  assert( pNew->nLTerm<=pNew->nLSlot );
+  pNew->u.vtab.idxNum = pIdxInfo->idxNum;
+  pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
+  pIdxInfo->needToFreeIdxStr = 0;
+  pNew->u.vtab.idxStr = pIdxInfo->idxStr;
+  pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
+      pIdxInfo->nOrderBy : 0);
+  pNew->rSetup = 0;
+  pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
+  pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);
+
+  /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
+  ** that the scan will visit at most one row. Clear it otherwise. */
+  if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){
+    pNew->wsFlags |= WHERE_ONEROW;
+  }else{
+    pNew->wsFlags &= ~WHERE_ONEROW;
   }
+  rc = whereLoopInsert(pBuilder, pNew);
+  if( pNew->u.vtab.needFree ){
+    sqlite3_free(pNew->u.vtab.idxStr);
+    pNew->u.vtab.needFree = 0;
+  }
+  WHERETRACE(0xffff, ("  bIn=%d prereqIn=%04llx prereqOut=%04llx\n",
+                      *pbIn, (sqlite3_uint64)mPrereq,
+                      (sqlite3_uint64)(pNew->prereq & ~mPrereq)));
+
+  return rc;
 }
-#else
-# define explainOneScan(u,v,w,x,y,z)
-#endif /* SQLITE_OMIT_EXPLAIN */
 
 
 /*
-** Generate code for the start of the iLevel-th loop in the WHERE clause
-** implementation described by pWInfo.
+** Add all WhereLoop objects for a table of the join identified by
+** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
+**
+** If there are no LEFT or CROSS JOIN joins in the query, both mPrereq and
+** mUnusable are set to 0. Otherwise, mPrereq is a mask of all FROM clause
+** entries that occur before the virtual table in the FROM clause and are
+** separated from it by at least one LEFT or CROSS JOIN. Similarly, the
+** mUnusable mask contains all FROM clause entries that occur after the
+** virtual table and are separated from it by at least one LEFT or 
+** CROSS JOIN. 
+**
+** For example, if the query were:
+**
+**   ... FROM t1, t2 LEFT JOIN t3, t4, vt CROSS JOIN t5, t6;
+**
+** then mPrereq corresponds to (t1, t2) and mUnusable to (t5, t6).
+**
+** All the tables in mPrereq must be scanned before the current virtual 
+** table. So any terms for which all prerequisites are satisfied by 
+** mPrereq may be specified as "usable" in all calls to xBestIndex. 
+** Conversely, all tables in mUnusable must be scanned after the current
+** virtual table, so any terms for which the prerequisites overlap with
+** mUnusable should always be configured as "not-usable" for xBestIndex.
 */
-static Bitmask codeOneLoopStart(
-  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
-  int iLevel,          /* Which level of pWInfo->a[] should be coded */
-  u16 wctrlFlags,      /* One of the WHERE_* flags defined in sqliteInt.h */
-  Bitmask notReady,    /* Which tables are currently available */
-  Expr *pWhere         /* Complete WHERE clause */
+static int whereLoopAddVirtual(
+  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
+  Bitmask mPrereq,             /* Tables that must be scanned before this one */
+  Bitmask mUnusable            /* Tables that must be scanned after this one */
 ){
-  int j, k;            /* Loop counters */
-  int iCur;            /* The VDBE cursor for the table */
-  int addrNxt;         /* Where to jump to continue with the next IN case */
-  int omitTable;       /* True if we use the index only */
-  int bRev;            /* True if we need to scan in reverse order */
-  WhereLevel *pLevel;  /* The where level to be coded */
-  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
-  WhereTerm *pTerm;               /* A WHERE clause term */
-  Parse *pParse;                  /* Parsing context */
-  Vdbe *v;                        /* The prepared stmt under constructions */
-  struct SrcList_item *pTabItem;  /* FROM clause term being coded */
-  int addrBrk;                    /* Jump here to break out of the loop */
-  int addrCont;                   /* Jump here to continue with next cycle */
-  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
-  int iReleaseReg = 0;      /* Temp register to free before returning */
-
+  int rc = SQLITE_OK;          /* Return code */
+  WhereInfo *pWInfo;           /* WHERE analysis context */
+  Parse *pParse;               /* The parsing context */
+  WhereClause *pWC;            /* The WHERE clause */
+  struct SrcList_item *pSrc;   /* The FROM clause term to search */
+  sqlite3_index_info *p;       /* Object to pass to xBestIndex() */
+  int nConstraint;             /* Number of constraints in p */
+  int bIn;                     /* True if plan uses IN(...) operator */
+  WhereLoop *pNew;
+  Bitmask mBest;               /* Tables used by best possible plan */
+
+  assert( (mPrereq & mUnusable)==0 );
+  pWInfo = pBuilder->pWInfo;
   pParse = pWInfo->pParse;
-  v = pParse->pVdbe;
-  pWC = pWInfo->pWC;
-  pLevel = &pWInfo->a[iLevel];
-  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
-  iCur = pTabItem->iCursor;
-  bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
-  omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0 
-           && (wctrlFlags & WHERE_FORCE_TABLE)==0;
+  pWC = pBuilder->pWC;
+  pNew = pBuilder->pNew;
+  pSrc = &pWInfo->pTabList->a[pNew->iTab];
+  assert( IsVirtual(pSrc->pTab) );
+  p = allocateIndexInfo(pParse, pWC, mUnusable, pSrc, pBuilder->pOrderBy);
+  if( p==0 ) return SQLITE_NOMEM_BKPT;
+  pNew->rSetup = 0;
+  pNew->wsFlags = WHERE_VIRTUALTABLE;
+  pNew->nLTerm = 0;
+  pNew->u.vtab.needFree = 0;
+  nConstraint = p->nConstraint;
+  if( whereLoopResize(pParse->db, pNew, nConstraint) ){
+    sqlite3DbFree(pParse->db, p);
+    return SQLITE_NOMEM_BKPT;
+  }
+
+  /* First call xBestIndex() with all constraints usable. */
+  WHERETRACE(0x40, ("  VirtualOne: all usable\n"));
+  rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, &bIn);
+
+  /* If the call to xBestIndex() with all terms enabled produced a plan
+  ** that does not require any source tables (IOW: a plan with mBest==0),
+  ** then there is no point in making any further calls to xBestIndex() 
+  ** since they will all return the same result (if the xBestIndex()
+  ** implementation is sane). */
+  if( rc==SQLITE_OK && (mBest = (pNew->prereq & ~mPrereq))!=0 ){
+    int seenZero = 0;             /* True if a plan with no prereqs seen */
+    int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
+    Bitmask mPrev = 0;
+    Bitmask mBestNoIn = 0;
+
+    /* If the plan produced by the earlier call uses an IN(...) term, call
+    ** xBestIndex again, this time with IN(...) terms disabled. */
+    if( bIn ){
+      WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));
+      rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, WO_IN, p, &bIn);
+      assert( bIn==0 );
+      mBestNoIn = pNew->prereq & ~mPrereq;
+      if( mBestNoIn==0 ){
+        seenZero = 1;
+        seenZeroNoIN = 1;
+      }
+    }
+
+    /* Call xBestIndex once for each distinct value of (prereqRight & ~mPrereq) 
+    ** in the set of terms that apply to the current virtual table.  */
+    while( rc==SQLITE_OK ){
+      int i;
+      Bitmask mNext = ALLBITS;
+      assert( mNext>0 );
+      for(i=0; i<nConstraint; i++){
+        Bitmask mThis = (
+            pWC->a[p->aConstraint[i].iTermOffset].prereqRight & ~mPrereq
+        );
+        if( mThis>mPrev && mThis<mNext ) mNext = mThis;
+      }
+      mPrev = mNext;
+      if( mNext==ALLBITS ) break;
+      if( mNext==mBest || mNext==mBestNoIn ) continue;
+      WHERETRACE(0x40, ("  VirtualOne: mPrev=%04llx mNext=%04llx\n",
+                       (sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));
+      rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mNext|mPrereq, 0, p, &bIn);
+      if( pNew->prereq==mPrereq ){
+        seenZero = 1;
+        if( bIn==0 ) seenZeroNoIN = 1;
+      }
+    }
 
-  /* Create labels for the "break" and "continue" instructions
-  ** for the current loop.  Jump to addrBrk to break out of a loop.
-  ** Jump to cont to go immediately to the next iteration of the
-  ** loop.
-  **
-  ** When there is an IN operator, we also have a "addrNxt" label that
-  ** means to continue with the next IN value combination.  When
-  ** there are no IN operators in the constraints, the "addrNxt" label
-  ** is the same as "addrBrk".
-  */
-  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
-  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+    /* If the calls to xBestIndex() in the above loop did not find a plan
+    ** that requires no source tables at all (i.e. one guaranteed to be
+    ** usable), make a call here with all source tables disabled */
+    if( rc==SQLITE_OK && seenZero==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));
+      rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mPrereq, 0, p, &bIn);
+      if( bIn==0 ) seenZeroNoIN = 1;
+    }
 
-  /* If this is the right table of a LEFT OUTER JOIN, allocate and
-  ** initialize a memory cell that records if this table matches any
-  ** row of the left table of the join.
-  */
-  if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
-    pLevel->iLeftJoin = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
-    VdbeComment((v, "init LEFT JOIN no-match flag"));
+    /* If the calls to xBestIndex() have so far failed to find a plan
+    ** that requires no source tables at all and does not use an IN(...)
+    ** operator, make a final call to obtain one here.  */
+    if( rc==SQLITE_OK && seenZeroNoIN==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));
+      rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mPrereq, WO_IN, p, &bIn);
+    }
   }
 
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  if(  (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
-    /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
-    **          to access the data.
-    */
-    int iReg;   /* P3 Value for OP_VFilter */
-    sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
-    int nConstraint = pVtabIdx->nConstraint;
-    struct sqlite3_index_constraint_usage *aUsage =
-                                                pVtabIdx->aConstraintUsage;
-    const struct sqlite3_index_constraint *aConstraint =
-                                                pVtabIdx->aConstraint;
+  if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);
+  sqlite3DbFree(pParse->db, p);
+  return rc;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
 
-    sqlite3ExprCachePush(pParse);
-    iReg = sqlite3GetTempRange(pParse, nConstraint+2);
-    for(j=1; j<=nConstraint; j++){
-      for(k=0; k<nConstraint; k++){
-        if( aUsage[k].argvIndex==j ){
-          int iTerm = aConstraint[k].iTermOffset;
-          sqlite3ExprCode(pParse, pWC->a[iTerm].pExpr->pRight, iReg+j+1);
+/*
+** Add WhereLoop entries to handle OR terms.  This works for either
+** btrees or virtual tables.
+*/
+static int whereLoopAddOr(
+  WhereLoopBuilder *pBuilder, 
+  Bitmask mPrereq, 
+  Bitmask mUnusable
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  WhereClause *pWC;
+  WhereLoop *pNew;
+  WhereTerm *pTerm, *pWCEnd;
+  int rc = SQLITE_OK;
+  int iCur;
+  WhereClause tempWC;
+  WhereLoopBuilder sSubBuild;
+  WhereOrSet sSum, sCur;
+  struct SrcList_item *pItem;
+  
+  pWC = pBuilder->pWC;
+  pWCEnd = pWC->a + pWC->nTerm;
+  pNew = pBuilder->pNew;
+  memset(&sSum, 0, sizeof(sSum));
+  pItem = pWInfo->pTabList->a + pNew->iTab;
+  iCur = pItem->iCursor;
+
+  for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){
+    if( (pTerm->eOperator & WO_OR)!=0
+     && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 
+    ){
+      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
+      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
+      WhereTerm *pOrTerm;
+      int once = 1;
+      int i, j;
+    
+      sSubBuild = *pBuilder;
+      sSubBuild.pOrderBy = 0;
+      sSubBuild.pOrSet = &sCur;
+
+      WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));
+      for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
+        if( (pOrTerm->eOperator & WO_AND)!=0 ){
+          sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
+        }else if( pOrTerm->leftCursor==iCur ){
+          tempWC.pWInfo = pWC->pWInfo;
+          tempWC.pOuter = pWC;
+          tempWC.op = TK_AND;
+          tempWC.nTerm = 1;
+          tempWC.a = pOrTerm;
+          sSubBuild.pWC = &tempWC;
+        }else{
+          continue;
+        }
+        sCur.n = 0;
+#ifdef WHERETRACE_ENABLED
+        WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n", 
+                   (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
+        if( sqlite3WhereTrace & 0x400 ){
+          sqlite3WhereClausePrint(sSubBuild.pWC);
+        }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+        if( IsVirtual(pItem->pTab) ){
+          rc = whereLoopAddVirtual(&sSubBuild, mPrereq, mUnusable);
+        }else
+#endif
+        {
+          rc = whereLoopAddBtree(&sSubBuild, mPrereq);
+        }
+        if( rc==SQLITE_OK ){
+          rc = whereLoopAddOr(&sSubBuild, mPrereq, mUnusable);
+        }
+        assert( rc==SQLITE_OK || sCur.n==0 );
+        if( sCur.n==0 ){
+          sSum.n = 0;
           break;
+        }else if( once ){
+          whereOrMove(&sSum, &sCur);
+          once = 0;
+        }else{
+          WhereOrSet sPrev;
+          whereOrMove(&sPrev, &sSum);
+          sSum.n = 0;
+          for(i=0; i<sPrev.n; i++){
+            for(j=0; j<sCur.n; j++){
+              whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq,
+                            sqlite3LogEstAdd(sPrev.a[i].rRun, sCur.a[j].rRun),
+                            sqlite3LogEstAdd(sPrev.a[i].nOut, sCur.a[j].nOut));
+            }
+          }
         }
       }
-      if( k==nConstraint ) break;
-    }
-    sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
-    sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
-    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pVtabIdx->idxStr,
-                      pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
-    pVtabIdx->needToFreeIdxStr = 0;
-    for(j=0; j<nConstraint; j++){
-      if( aUsage[j].omit ){
-        int iTerm = aConstraint[j].iTermOffset;
-        disableTerm(pLevel, &pWC->a[iTerm]);
+      pNew->nLTerm = 1;
+      pNew->aLTerm[0] = pTerm;
+      pNew->wsFlags = WHERE_MULTI_OR;
+      pNew->rSetup = 0;
+      pNew->iSortIdx = 0;
+      memset(&pNew->u, 0, sizeof(pNew->u));
+      for(i=0; rc==SQLITE_OK && i<sSum.n; i++){
+        /* TUNING: Currently sSum.a[i].rRun is set to the sum of the costs
+        ** of all sub-scans required by the OR-scan. However, due to rounding
+        ** errors, it may be that the cost of the OR-scan is equal to its
+        ** most expensive sub-scan. Add the smallest possible penalty 
+        ** (equivalent to multiplying the cost by 1.07) to ensure that 
+        ** this does not happen. Otherwise, for WHERE clauses such as the
+        ** following where there is an index on "y":
+        **
+        **     WHERE likelihood(x=?, 0.99) OR y=?
+        **
+        ** the planner may elect to "OR" together a full-table scan and an
+        ** index lookup. And other similarly odd results.  */
+        pNew->rRun = sSum.a[i].rRun + 1;
+        pNew->nOut = sSum.a[i].nOut;
+        pNew->prereq = sSum.a[i].prereq;
+        rc = whereLoopInsert(pBuilder, pNew);
       }
+      WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));
     }
-    pLevel->op = OP_VNext;
-    pLevel->p1 = iCur;
-    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
-    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
-    sqlite3ExprCachePop(pParse, 1);
-  }else
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-  if( pLevel->plan.wsFlags & WHERE_ROWID_EQ ){
-    /* Case 1:  We can directly reference a single row using an
-    **          equality comparison against the ROWID field.  Or
-    **          we reference multiple rows using a "rowid IN (...)"
-    **          construct.
-    */
-    iReleaseReg = sqlite3GetTempReg(pParse);
-    pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
-    assert( pTerm!=0 );
-    assert( pTerm->pExpr!=0 );
-    assert( pTerm->leftCursor==iCur );
-    assert( omitTable==0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, iReleaseReg);
-    addrNxt = pLevel->addrNxt;
-    sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt);
-    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
-    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-    VdbeComment((v, "pk"));
-    pLevel->op = OP_Noop;
-  }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){
-    /* Case 2:  We have an inequality comparison against the ROWID field.
-    */
-    int testOp = OP_Noop;
-    int start;
-    int memEndValue = 0;
-    WhereTerm *pStart, *pEnd;
-
-    assert( omitTable==0 );
-    pStart = findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0);
-    pEnd = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0);
-    if( bRev ){
-      pTerm = pStart;
-      pStart = pEnd;
-      pEnd = pTerm;
-    }
-    if( pStart ){
-      Expr *pX;             /* The expression that defines the start bound */
-      int r1, rTemp;        /* Registers for holding the start boundary */
-
-      /* The following constant maps TK_xx codes into corresponding 
-      ** seek opcodes.  It depends on a particular ordering of TK_xx
-      */
-      const u8 aMoveOp[] = {
-           /* TK_GT */  OP_SeekGt,
-           /* TK_LE */  OP_SeekLe,
-           /* TK_LT */  OP_SeekLt,
-           /* TK_GE */  OP_SeekGe
-      };
-      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
-      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
-      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
+  }
+  return rc;
+}
 
-      testcase( pStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-      pX = pStart->pExpr;
-      assert( pX!=0 );
-      assert( pStart->leftCursor==iCur );
-      r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
-      sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
-      VdbeComment((v, "pk"));
-      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
-      sqlite3ReleaseTempReg(pParse, rTemp);
-      disableTerm(pLevel, pStart);
-    }else{
-      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
-    }
-    if( pEnd ){
-      Expr *pX;
-      pX = pEnd->pExpr;
-      assert( pX!=0 );
-      assert( pEnd->leftCursor==iCur );
-      testcase( pEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-      memEndValue = ++pParse->nMem;
-      sqlite3ExprCode(pParse, pX->pRight, memEndValue);
-      if( pX->op==TK_LT || pX->op==TK_GT ){
-        testOp = bRev ? OP_Le : OP_Ge;
-      }else{
-        testOp = bRev ? OP_Lt : OP_Gt;
+/*
+** Add all WhereLoop objects for all tables 
+*/
+static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  Bitmask mPrereq = 0;
+  Bitmask mPrior = 0;
+  int iTab;
+  SrcList *pTabList = pWInfo->pTabList;
+  struct SrcList_item *pItem;
+  struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];
+  sqlite3 *db = pWInfo->pParse->db;
+  int rc = SQLITE_OK;
+  WhereLoop *pNew;
+  u8 priorJointype = 0;
+
+  /* Loop over the tables in the join, from left to right */
+  pNew = pBuilder->pNew;
+  whereLoopInit(pNew);
+  for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
+    Bitmask mUnusable = 0;
+    pNew->iTab = iTab;
+    pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
+    if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){
+      /* This condition is true when pItem is the FROM clause term on the
+      ** right-hand-side of a LEFT or CROSS JOIN.  */
+      mPrereq = mPrior;
+    }
+    priorJointype = pItem->fg.jointype;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( IsVirtual(pItem->pTab) ){
+      struct SrcList_item *p;
+      for(p=&pItem[1]; p<pEnd; p++){
+        if( mUnusable || (p->fg.jointype & (JT_LEFT|JT_CROSS)) ){
+          mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
+        }
       }
-      disableTerm(pLevel, pEnd);
-    }
-    start = sqlite3VdbeCurrentAddr(v);
-    pLevel->op = bRev ? OP_Prev : OP_Next;
-    pLevel->p1 = iCur;
-    pLevel->p2 = start;
-    if( pStart==0 && pEnd==0 ){
-      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
-    }else{
-      assert( pLevel->p5==0 );
+      rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);
+    }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+    {
+      rc = whereLoopAddBtree(pBuilder, mPrereq);
     }
-    if( testOp!=OP_Noop ){
-      iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
-      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
-      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+    if( rc==SQLITE_OK ){
+      rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);
     }
-  }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
-    /* Case 3: A scan using an index.
-    **
-    **         The WHERE clause may contain zero or more equality 
-    **         terms ("==" or "IN" operators) that refer to the N
-    **         left-most columns of the index. It may also contain
-    **         inequality constraints (>, <, >= or <=) on the indexed
-    **         column that immediately follows the N equalities. Only 
-    **         the right-most column can be an inequality - the rest must
-    **         use the "==" and "IN" operators. For example, if the 
-    **         index is on (x,y,z), then the following clauses are all 
-    **         optimized:
-    **
-    **            x=5
-    **            x=5 AND y=10
-    **            x=5 AND y<10
-    **            x=5 AND y>5 AND y<10
-    **            x=5 AND y=5 AND z<=10
-    **
-    **         The z<10 term of the following cannot be used, only
-    **         the x=5 term:
-    **
-    **            x=5 AND z<10
-    **
-    **         N may be zero if there are inequality constraints.
-    **         If there are no inequality constraints, then N is at
-    **         least one.
-    **
-    **         This case is also used when there are no WHERE clause
-    **         constraints but an index is selected anyway, in order
-    **         to force the output order to conform to an ORDER BY.
-    */  
-    static const u8 aStartOp[] = {
-      0,
-      0,
-      OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
-      OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
-      OP_SeekGt,           /* 4: (start_constraints  && !startEq && !bRev) */
-      OP_SeekLt,           /* 5: (start_constraints  && !startEq &&  bRev) */
-      OP_SeekGe,           /* 6: (start_constraints  &&  startEq && !bRev) */
-      OP_SeekLe            /* 7: (start_constraints  &&  startEq &&  bRev) */
-    };
-    static const u8 aEndOp[] = {
-      OP_Noop,             /* 0: (!end_constraints) */
-      OP_IdxGE,            /* 1: (end_constraints && !bRev) */
-      OP_IdxLT             /* 2: (end_constraints && bRev) */
-    };
-    int nEq = pLevel->plan.nEq;  /* Number of == or IN terms */
-    int isMinQuery = 0;          /* If this is an optimized SELECT min(x).. */
-    int regBase;                 /* Base register holding constraint values */
-    int r1;                      /* Temp register */
-    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
-    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
-    int startEq;                 /* True if range start uses ==, >= or <= */
-    int endEq;                   /* True if range end uses ==, >= or <= */
-    int start_constraints;       /* Start of range is constrained */
-    int nConstraint;             /* Number of constraint terms */
-    Index *pIdx;                 /* The index we will be using */
-    int iIdxCur;                 /* The VDBE cursor for the index */
-    int nExtraReg = 0;           /* Number of extra registers needed */
-    int op;                      /* Instruction opcode */
-    char *zStartAff;             /* Affinity for start of range constraint */
-    char *zEndAff;               /* Affinity for end of range constraint */
+    mPrior |= pNew->maskSelf;
+    if( rc || db->mallocFailed ) break;
+  }
 
-    pIdx = pLevel->plan.u.pIdx;
-    iIdxCur = pLevel->iIdxCur;
-    k = pIdx->aiColumn[nEq];     /* Column for inequality constraints */
+  whereLoopClear(db, pNew);
+  return rc;
+}
 
-    /* If this loop satisfies a sort order (pOrderBy) request that 
-    ** was passed to this function to implement a "SELECT min(x) ..." 
-    ** query, then the caller will only allow the loop to run for
-    ** a single iteration. This means that the first row returned
-    ** should not have a NULL value stored in 'x'. If column 'x' is
-    ** the first one after the nEq equality constraints in the index,
-    ** this requires some special handling.
-    */
-    if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0
-     && (pLevel->plan.wsFlags&WHERE_ORDERBY)
-     && (pIdx->nColumn>nEq)
-    ){
-      /* assert( pOrderBy->nExpr==1 ); */
-      /* assert( pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq] ); */
-      isMinQuery = 1;
-      nExtraReg = 1;
-    }
+/*
+** Examine a WherePath (with the addition of the extra WhereLoop of the 5th
+** parameters) to see if it outputs rows in the requested ORDER BY
+** (or GROUP BY) without requiring a separate sort operation.  Return N:
+** 
+**   N>0:   N terms of the ORDER BY clause are satisfied
+**   N==0:  No terms of the ORDER BY clause are satisfied
+**   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   
+**
+** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
+** strict.  With GROUP BY and DISTINCT the only requirement is that
+** equivalent rows appear immediately adjacent to one another.  GROUP BY
+** and DISTINCT do not require rows to appear in any particular order as long
+** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT
+** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
+** pOrderBy terms must be matched in strict left-to-right order.
+*/
+static i8 wherePathSatisfiesOrderBy(
+  WhereInfo *pWInfo,    /* The WHERE clause */
+  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
+  WherePath *pPath,     /* The WherePath to check */
+  u16 wctrlFlags,       /* WHERE_GROUPBY or _DISTINCTBY or _ORDERBY_LIMIT */
+  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
+  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
+  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
+){
+  u8 revSet;            /* True if rev is known */
+  u8 rev;               /* Composite sort order */
+  u8 revIdx;            /* Index sort order */
+  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
+  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
+  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
+  u16 eqOpMask;         /* Allowed equality operators */
+  u16 nKeyCol;          /* Number of key columns in pIndex */
+  u16 nColumn;          /* Total number of ordered columns in the index */
+  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
+  int iLoop;            /* Index of WhereLoop in pPath being processed */
+  int i, j;             /* Loop counters */
+  int iCur;             /* Cursor number for current WhereLoop */
+  int iColumn;          /* A column number within table iCur */
+  WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
+  WhereTerm *pTerm;     /* A single term of the WHERE clause */
+  Expr *pOBExpr;        /* An expression from the ORDER BY clause */
+  CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */
+  Index *pIndex;        /* The index associated with pLoop */
+  sqlite3 *db = pWInfo->pParse->db;  /* Database connection */
+  Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */
+  Bitmask obDone;       /* Mask of all ORDER BY terms */
+  Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */
+  Bitmask ready;              /* Mask of inner loops */
 
-    /* Find any inequality constraint terms for the start and end 
-    ** of the range. 
-    */
-    if( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ){
-      pRangeEnd = findTerm(pWC, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
-      nExtraReg = 1;
+  /*
+  ** We say the WhereLoop is "one-row" if it generates no more than one
+  ** row of output.  A WhereLoop is one-row if all of the following are true:
+  **  (a) All index columns match with WHERE_COLUMN_EQ.
+  **  (b) The index is unique
+  ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
+  ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
+  **
+  ** We say the WhereLoop is "order-distinct" if the set of columns from
+  ** that WhereLoop that are in the ORDER BY clause are different for every
+  ** row of the WhereLoop.  Every one-row WhereLoop is automatically
+  ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause
+  ** is not order-distinct. To be order-distinct is not quite the same as being
+  ** UNIQUE since a UNIQUE column or index can have multiple rows that 
+  ** are NULL and NULL values are equivalent for the purpose of order-distinct.
+  ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
+  **
+  ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
+  ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
+  ** automatically order-distinct.
+  */
+
+  assert( pOrderBy!=0 );
+  if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+
+  nOrderBy = pOrderBy->nExpr;
+  testcase( nOrderBy==BMS-1 );
+  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
+  isOrderDistinct = 1;
+  obDone = MASKBIT(nOrderBy)-1;
+  orderDistinctMask = 0;
+  ready = 0;
+  eqOpMask = WO_EQ | WO_IS | WO_ISNULL;
+  if( wctrlFlags & WHERE_ORDERBY_LIMIT ) eqOpMask |= WO_IN;
+  for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
+    if( iLoop>0 ) ready |= pLoop->maskSelf;
+    if( iLoop<nLoop ){
+      pLoop = pPath->aLoop[iLoop];
+      if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
+    }else{
+      pLoop = pLast;
     }
-    if( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ){
-      pRangeStart = findTerm(pWC, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
-      nExtraReg = 1;
+    if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
+      if( pLoop->u.vtab.isOrdered ) obSat = obDone;
+      break;
     }
+    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
 
-    /* Generate code to evaluate all constraint terms using == or IN
-    ** and store the values of those terms in an array of registers
-    ** starting at regBase.
+    /* Mark off any ORDER BY term X that is a column in the table of
+    ** the current loop for which there is term in the WHERE
+    ** clause of the form X IS NULL or X=? that reference only outer
+    ** loops.
     */
-    regBase = codeAllEqualityTerms(
-        pParse, pLevel, pWC, notReady, nExtraReg, &zStartAff
-    );
-    zEndAff = sqlite3DbStrDup(pParse->db, zStartAff);
-    addrNxt = pLevel->addrNxt;
+    for(i=0; i<nOrderBy; i++){
+      if( MASKBIT(i) & obSat ) continue;
+      pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+      if( pOBExpr->op!=TK_COLUMN ) continue;
+      if( pOBExpr->iTable!=iCur ) continue;
+      pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+                       ~ready, eqOpMask, 0);
+      if( pTerm==0 ) continue;
+      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
+        const char *z1, *z2;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z1 = pColl->zName;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z2 = pColl->zName;
+        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+        testcase( pTerm->pExpr->op==TK_IS );
+      }
+      obSat |= MASKBIT(i);
+    }
+
+    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
+      if( pLoop->wsFlags & WHERE_IPK ){
+        pIndex = 0;
+        nKeyCol = 0;
+        nColumn = 1;
+      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
+        return 0;
+      }else{
+        nKeyCol = pIndex->nKeyCol;
+        nColumn = pIndex->nColumn;
+        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
+        assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
+                          || !HasRowid(pIndex->pTable));
+        isOrderDistinct = IsUniqueIndex(pIndex);
+      }
 
-    /* If we are doing a reverse order scan on an ascending index, or
-    ** a forward order scan on a descending index, interchange the 
-    ** start and end terms (pRangeStart and pRangeEnd).
-    */
-    if( nEq<pIdx->nColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){
-      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
-    }
+      /* Loop through all columns of the index and deal with the ones
+      ** that are not constrained by == or IN.
+      */
+      rev = revSet = 0;
+      distinctColumns = 0;
+      for(j=0; j<nColumn; j++){
+        u8 bOnce;   /* True to run the ORDER BY search loop */
 
-    testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
-    testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
-    testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
-    testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
-    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
-    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
-    start_constraints = pRangeStart || nEq>0;
+        /* Skip over == and IS and ISNULL terms.
+        ** (Also skip IN terms when doing WHERE_ORDERBY_LIMIT processing)
+        */
+        if( j<pLoop->u.btree.nEq
+         && pLoop->nSkip==0
+         && ((i = pLoop->aLTerm[j]->eOperator) & eqOpMask)!=0
+        ){
+          if( i & WO_ISNULL ){
+            testcase( isOrderDistinct );
+            isOrderDistinct = 0;
+          }
+          continue;  
+        }
 
-    /* Seek the index cursor to the start of the range. */
-    nConstraint = nEq;
-    if( pRangeStart ){
-      Expr *pRight = pRangeStart->pExpr->pRight;
-      sqlite3ExprCode(pParse, pRight, regBase+nEq);
-      if( (pRangeStart->wtFlags & TERM_VNULL)==0 ){
-        sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt);
-      }
-      if( zStartAff ){
-        if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_NONE){
-          /* Since the comparison is to be performed with no conversions
-          ** applied to the operands, set the affinity to apply to pRight to 
-          ** SQLITE_AFF_NONE.  */
-          zStartAff[nEq] = SQLITE_AFF_NONE;
+        /* Get the column number in the table (iColumn) and sort order
+        ** (revIdx) for the j-th column of the index.
+        */
+        if( pIndex ){
+          iColumn = pIndex->aiColumn[j];
+          revIdx = pIndex->aSortOrder[j];
+          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
+        }else{
+          iColumn = XN_ROWID;
+          revIdx = 0;
         }
-        if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
-          zStartAff[nEq] = SQLITE_AFF_NONE;
+
+        /* An unconstrained column that might be NULL means that this
+        ** WhereLoop is not well-ordered
+        */
+        if( isOrderDistinct
+         && iColumn>=0
+         && j>=pLoop->u.btree.nEq
+         && pIndex->pTable->aCol[iColumn].notNull==0
+        ){
+          isOrderDistinct = 0;
         }
-      }  
-      nConstraint++;
-      testcase( pRangeStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    }else if( isMinQuery ){
-      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
-      nConstraint++;
-      startEq = 0;
-      start_constraints = 1;
-    }
-    codeApplyAffinity(pParse, regBase, nConstraint, zStartAff);
-    op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
-    assert( op!=0 );
-    testcase( op==OP_Rewind );
-    testcase( op==OP_Last );
-    testcase( op==OP_SeekGt );
-    testcase( op==OP_SeekGe );
-    testcase( op==OP_SeekLe );
-    testcase( op==OP_SeekLt );
-    sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
 
-    /* Load the value for the inequality constraint at the end of the
-    ** range (if any).
-    */
-    nConstraint = nEq;
-    if( pRangeEnd ){
-      Expr *pRight = pRangeEnd->pExpr->pRight;
-      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
-      sqlite3ExprCode(pParse, pRight, regBase+nEq);
-      if( (pRangeEnd->wtFlags & TERM_VNULL)==0 ){
-        sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt);
-      }
-      if( zEndAff ){
-        if( sqlite3CompareAffinity(pRight, zEndAff[nEq])==SQLITE_AFF_NONE){
-          /* Since the comparison is to be performed with no conversions
-          ** applied to the operands, set the affinity to apply to pRight to 
-          ** SQLITE_AFF_NONE.  */
-          zEndAff[nEq] = SQLITE_AFF_NONE;
+        /* Find the ORDER BY term that corresponds to the j-th column
+        ** of the index and mark that ORDER BY term off 
+        */
+        bOnce = 1;
+        isMatch = 0;
+        for(i=0; bOnce && i<nOrderBy; i++){
+          if( MASKBIT(i) & obSat ) continue;
+          pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+          testcase( wctrlFlags & WHERE_GROUPBY );
+          testcase( wctrlFlags & WHERE_DISTINCTBY );
+          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
+          if( iColumn>=(-1) ){
+            if( pOBExpr->op!=TK_COLUMN ) continue;
+            if( pOBExpr->iTable!=iCur ) continue;
+            if( pOBExpr->iColumn!=iColumn ) continue;
+          }else{
+            if( sqlite3ExprCompare(pOBExpr,pIndex->aColExpr->a[j].pExpr,iCur) ){
+              continue;
+            }
+          }
+          if( iColumn>=0 ){
+            pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+            if( !pColl ) pColl = db->pDfltColl;
+            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
+          }
+          isMatch = 1;
+          break;
         }
-        if( sqlite3ExprNeedsNoAffinityChange(pRight, zEndAff[nEq]) ){
-          zEndAff[nEq] = SQLITE_AFF_NONE;
+        if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
+          /* Make sure the sort order is compatible in an ORDER BY clause.
+          ** Sort order is irrelevant for a GROUP BY clause. */
+          if( revSet ){
+            if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0;
+          }else{
+            rev = revIdx ^ pOrderBy->a[i].sortOrder;
+            if( rev ) *pRevMask |= MASKBIT(iLoop);
+            revSet = 1;
+          }
         }
-      }  
-      codeApplyAffinity(pParse, regBase, nEq+1, zEndAff);
-      nConstraint++;
-      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    }
-    sqlite3DbFree(pParse->db, zStartAff);
-    sqlite3DbFree(pParse->db, zEndAff);
-
-    /* Top of the loop body */
-    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+        if( isMatch ){
+          if( iColumn<0 ){
+            testcase( distinctColumns==0 );
+            distinctColumns = 1;
+          }
+          obSat |= MASKBIT(i);
+        }else{
+          /* No match found */
+          if( j==0 || j<nKeyCol ){
+            testcase( isOrderDistinct!=0 );
+            isOrderDistinct = 0;
+          }
+          break;
+        }
+      } /* end Loop over all index columns */
+      if( distinctColumns ){
+        testcase( isOrderDistinct==0 );
+        isOrderDistinct = 1;
+      }
+    } /* end-if not one-row */
 
-    /* Check if the index cursor is past the end of the range. */
-    op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)];
-    testcase( op==OP_Noop );
-    testcase( op==OP_IdxGE );
-    testcase( op==OP_IdxLT );
-    if( op!=OP_Noop ){
-      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
-      sqlite3VdbeChangeP5(v, endEq!=bRev ?1:0);
+    /* Mark off any other ORDER BY terms that reference pLoop */
+    if( isOrderDistinct ){
+      orderDistinctMask |= pLoop->maskSelf;
+      for(i=0; i<nOrderBy; i++){
+        Expr *p;
+        Bitmask mTerm;
+        if( MASKBIT(i) & obSat ) continue;
+        p = pOrderBy->a[i].pExpr;
+        mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);
+        if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
+        if( (mTerm&~orderDistinctMask)==0 ){
+          obSat |= MASKBIT(i);
+        }
+      }
     }
-
-    /* If there are inequality constraints, check that the value
-    ** of the table column that the inequality contrains is not NULL.
-    ** If it is, jump to the next iteration of the loop.
-    */
-    r1 = sqlite3GetTempReg(pParse);
-    testcase( pLevel->plan.wsFlags & WHERE_BTM_LIMIT );
-    testcase( pLevel->plan.wsFlags & WHERE_TOP_LIMIT );
-    if( (pLevel->plan.wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
-      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
-      sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
-    }
-    sqlite3ReleaseTempReg(pParse, r1);
-
-    /* Seek the table cursor, if required */
-    disableTerm(pLevel, pRangeStart);
-    disableTerm(pLevel, pRangeEnd);
-    if( !omitTable ){
-      iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
-      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-      sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
+  } /* End the loop over all WhereLoops from outer-most down to inner-most */
+  if( obSat==obDone ) return (i8)nOrderBy;
+  if( !isOrderDistinct ){
+    for(i=nOrderBy-1; i>0; i--){
+      Bitmask m = MASKBIT(i) - 1;
+      if( (obSat&m)==m ) return i;
     }
+    return 0;
+  }
+  return -1;
+}
 
-    /* Record the instruction used to terminate the loop. Disable 
-    ** WHERE clause terms made redundant by the index range scan.
-    */
-    if( pLevel->plan.wsFlags & WHERE_UNIQUE ){
-      pLevel->op = OP_Noop;
-    }else if( bRev ){
-      pLevel->op = OP_Prev;
-    }else{
-      pLevel->op = OP_Next;
-    }
-    pLevel->p1 = iIdxCur;
-  }else
 
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
-  if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
-    /* Case 4:  Two or more separately indexed terms connected by OR
-    **
-    ** Example:
-    **
-    **   CREATE TABLE t1(a,b,c,d);
-    **   CREATE INDEX i1 ON t1(a);
-    **   CREATE INDEX i2 ON t1(b);
-    **   CREATE INDEX i3 ON t1(c);
-    **
-    **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
-    **
-    ** In the example, there are three indexed terms connected by OR.
-    ** The top of the loop looks like this:
-    **
-    **          Null       1                # Zero the rowset in reg 1
-    **
-    ** Then, for each indexed term, the following. The arguments to
-    ** RowSetTest are such that the rowid of the current row is inserted
-    ** into the RowSet. If it is already present, control skips the
-    ** Gosub opcode and jumps straight to the code generated by WhereEnd().
-    **
-    **        sqlite3WhereBegin(<term>)
-    **          RowSetTest                  # Insert rowid into rowset
-    **          Gosub      2 A
-    **        sqlite3WhereEnd()
-    **
-    ** Following the above, code to terminate the loop. Label A, the target
-    ** of the Gosub above, jumps to the instruction right after the Goto.
-    **
-    **          Null       1                # Zero the rowset in reg 1
-    **          Goto       B                # The loop is finished.
-    **
-    **       A: <loop body>                 # Return data, whatever.
-    **
-    **          Return     2                # Jump back to the Gosub
-    **
-    **       B: <after the loop>
-    **
-    */
-    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
-    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
+/*
+** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),
+** the planner assumes that the specified pOrderBy list is actually a GROUP
+** BY clause - and so any order that groups rows as required satisfies the
+** request.
+**
+** Normally, in this case it is not possible for the caller to determine
+** whether or not the rows are really being delivered in sorted order, or
+** just in some other order that provides the required grouping. However,
+** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then
+** this function may be called on the returned WhereInfo object. It returns
+** true if the rows really will be sorted in the specified order, or false
+** otherwise.
+**
+** For example, assuming:
+**
+**   CREATE INDEX i1 ON t1(x, Y);
+**
+** then
+**
+**   SELECT * FROM t1 GROUP BY x,y ORDER BY x,y;   -- IsSorted()==1
+**   SELECT * FROM t1 GROUP BY y,x ORDER BY y,x;   -- IsSorted()==0
+*/
+SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){
+  assert( pWInfo->wctrlFlags & WHERE_GROUPBY );
+  assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );
+  return pWInfo->sorted;
+}
 
-    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
-    int regRowset = 0;                        /* Register for RowSet object */
-    int regRowid = 0;                         /* Register holding rowid */
-    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
-    int iRetInit;                             /* Address of regReturn init */
-    int untestedTerms = 0;             /* Some terms not completely tested */
-    int ii;                            /* Loop counter */
-    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
-   
-    pTerm = pLevel->plan.u.pTerm;
-    assert( pTerm!=0 );
-    assert( pTerm->eOperator==WO_OR );
-    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
-    pOrWc = &pTerm->u.pOrInfo->wc;
-    pLevel->op = OP_Return;
-    pLevel->p1 = regReturn;
+#ifdef WHERETRACE_ENABLED
+/* For debugging use only: */
+static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
+  static char zName[65];
+  int i;
+  for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }
+  if( pLast ) zName[i++] = pLast->cId;
+  zName[i] = 0;
+  return zName;
+}
+#endif
 
-    /* Set up a new SrcList ni pOrTab containing the table being scanned
-    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
-    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
-    */
-    if( pWInfo->nLevel>1 ){
-      int nNotReady;                 /* The number of notReady tables */
-      struct SrcList_item *origSrc;     /* Original list of tables */
-      nNotReady = pWInfo->nLevel - iLevel - 1;
-      pOrTab = sqlite3StackAllocRaw(pParse->db,
-                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
-      if( pOrTab==0 ) return notReady;
-      pOrTab->nAlloc = (i16)(nNotReady + 1);
-      pOrTab->nSrc = pOrTab->nAlloc;
-      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
-      origSrc = pWInfo->pTabList->a;
-      for(k=1; k<=nNotReady; k++){
-        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
-      }
-    }else{
-      pOrTab = pWInfo->pTabList;
-    }
+/*
+** Return the cost of sorting nRow rows, assuming that the keys have 
+** nOrderby columns and that the first nSorted columns are already in
+** order.
+*/
+static LogEst whereSortingCost(
+  WhereInfo *pWInfo,
+  LogEst nRow,
+  int nOrderBy,
+  int nSorted
+){
+  /* TUNING: Estimated cost of a full external sort, where N is 
+  ** the number of rows to sort is:
+  **
+  **   cost = (3.0 * N * log(N)).
+  ** 
+  ** Or, if the order-by clause has X terms but only the last Y 
+  ** terms are out of order, then block-sorting will reduce the 
+  ** sorting cost to:
+  **
+  **   cost = (3.0 * N * log(N)) * (Y/X)
+  **
+  ** The (Y/X) term is implemented using stack variable rScale
+  ** below.  */
+  LogEst rScale, rSortCost;
+  assert( nOrderBy>0 && 66==sqlite3LogEst(100) );
+  rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;
+  rSortCost = nRow + rScale + 16;
 
-    /* Initialize the rowset register to contain NULL. An SQL NULL is 
-    ** equivalent to an empty rowset.
-    **
-    ** Also initialize regReturn to contain the address of the instruction 
-    ** immediately following the OP_Return at the bottom of the loop. This
-    ** is required in a few obscure LEFT JOIN cases where control jumps
-    ** over the top of the loop into the body of it. In this case the 
-    ** correct response for the end-of-loop code (the OP_Return) is to 
-    ** fall through to the next instruction, just as an OP_Next does if
-    ** called on an uninitialized cursor.
-    */
-    if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
-      regRowset = ++pParse->nMem;
-      regRowid = ++pParse->nMem;
-      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
-    }
-    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
+  /* Multiple by log(M) where M is the number of output rows.
+  ** Use the LIMIT for M if it is smaller */
+  if( (pWInfo->wctrlFlags & WHERE_USE_LIMIT)!=0 && pWInfo->iLimit<nRow ){
+    nRow = pWInfo->iLimit;
+  }
+  rSortCost += estLog(nRow);
+  return rSortCost;
+}
 
-    /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y
-    ** Then for every term xN, evaluate as the subexpression: xN AND z
-    ** That way, terms in y that are factored into the disjunction will
-    ** be picked up by the recursive calls to sqlite3WhereBegin() below.
-    */
-    if( pWC->nTerm>1 ){
-      pAndExpr = sqlite3ExprAlloc(pParse->db, TK_AND, 0, 0);
-      pAndExpr->pRight = pWhere;
-    }
+/*
+** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
+** attempts to find the lowest cost path that visits each WhereLoop
+** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
+**
+** Assume that the total number of output rows that will need to be sorted
+** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting
+** costs if nRowEst==0.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
+** error occurs.
+*/
+static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
+  int mxChoice;             /* Maximum number of simultaneous paths tracked */
+  int nLoop;                /* Number of terms in the join */
+  Parse *pParse;            /* Parsing context */
+  sqlite3 *db;              /* The database connection */
+  int iLoop;                /* Loop counter over the terms of the join */
+  int ii, jj;               /* Loop counters */
+  int mxI = 0;              /* Index of next entry to replace */
+  int nOrderBy;             /* Number of ORDER BY clause terms */
+  LogEst mxCost = 0;        /* Maximum cost of a set of paths */
+  LogEst mxUnsorted = 0;    /* Maximum unsorted cost of a set of path */
+  int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
+  WherePath *aFrom;         /* All nFrom paths at the previous level */
+  WherePath *aTo;           /* The nTo best paths at the current level */
+  WherePath *pFrom;         /* An element of aFrom[] that we are working on */
+  WherePath *pTo;           /* An element of aTo[] that we are working on */
+  WhereLoop *pWLoop;        /* One of the WhereLoop objects */
+  WhereLoop **pX;           /* Used to divy up the pSpace memory */
+  LogEst *aSortCost = 0;    /* Sorting and partial sorting costs */
+  char *pSpace;             /* Temporary memory used by this routine */
+  int nSpace;               /* Bytes of space allocated at pSpace */
 
-    for(ii=0; ii<pOrWc->nTerm; ii++){
-      WhereTerm *pOrTerm = &pOrWc->a[ii];
-      if( pOrTerm->leftCursor==iCur || pOrTerm->eOperator==WO_AND ){
-        WhereInfo *pSubWInfo;          /* Info for single OR-term scan */
-        Expr *pOrExpr = pOrTerm->pExpr;
-        if( pAndExpr ){
-          pAndExpr->pLeft = pOrExpr;
-          pOrExpr = pAndExpr;
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  nLoop = pWInfo->nLevel;
+  /* TUNING: For simple queries, only the best path is tracked.
+  ** For 2-way joins, the 5 best paths are followed.
+  ** For joins of 3 or more tables, track the 10 best paths */
+  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);
+  assert( nLoop<=pWInfo->pTabList->nSrc );
+  WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d)\n", nRowEst));
+
+  /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this
+  ** case the purpose of this call is to estimate the number of rows returned
+  ** by the overall query. Once this estimate has been obtained, the caller
+  ** will invoke this function a second time, passing the estimate as the
+  ** nRowEst parameter.  */
+  if( pWInfo->pOrderBy==0 || nRowEst==0 ){
+    nOrderBy = 0;
+  }else{
+    nOrderBy = pWInfo->pOrderBy->nExpr;
+  }
+
+  /* Allocate and initialize space for aTo, aFrom and aSortCost[] */
+  nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
+  nSpace += sizeof(LogEst) * nOrderBy;
+  pSpace = sqlite3DbMallocRawNN(db, nSpace);
+  if( pSpace==0 ) return SQLITE_NOMEM_BKPT;
+  aTo = (WherePath*)pSpace;
+  aFrom = aTo+mxChoice;
+  memset(aFrom, 0, sizeof(aFrom[0]));
+  pX = (WhereLoop**)(aFrom+mxChoice);
+  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
+    pFrom->aLoop = pX;
+  }
+  if( nOrderBy ){
+    /* If there is an ORDER BY clause and it is not being ignored, set up
+    ** space for the aSortCost[] array. Each element of the aSortCost array
+    ** is either zero - meaning it has not yet been initialized - or the
+    ** cost of sorting nRowEst rows of data where the first X terms of
+    ** the ORDER BY clause are already in order, where X is the array 
+    ** index.  */
+    aSortCost = (LogEst*)pX;
+    memset(aSortCost, 0, sizeof(LogEst) * nOrderBy);
+  }
+  assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] );
+  assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX );
+
+  /* Seed the search with a single WherePath containing zero WhereLoops.
+  **
+  ** TUNING: Do not let the number of iterations go above 28.  If the cost
+  ** of computing an automatic index is not paid back within the first 28
+  ** rows, then do not use the automatic index. */
+  aFrom[0].nRow = MIN(pParse->nQueryLoop, 48);  assert( 48==sqlite3LogEst(28) );
+  nFrom = 1;
+  assert( aFrom[0].isOrdered==0 );
+  if( nOrderBy ){
+    /* If nLoop is zero, then there are no FROM terms in the query. Since
+    ** in this case the query may return a maximum of one row, the results
+    ** are already in the requested order. Set isOrdered to nOrderBy to
+    ** indicate this. Or, if nLoop is greater than zero, set isOrdered to
+    ** -1, indicating that the result set may or may not be ordered, 
+    ** depending on the loops added to the current plan.  */
+    aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy;
+  }
+
+  /* Compute successively longer WherePaths using the previous generation
+  ** of WherePaths as the basis for the next.  Keep track of the mxChoice
+  ** best paths at each generation */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    nTo = 0;
+    for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){
+      for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
+        LogEst nOut;                      /* Rows visited by (pFrom+pWLoop) */
+        LogEst rCost;                     /* Cost of path (pFrom+pWLoop) */
+        LogEst rUnsorted;                 /* Unsorted cost of (pFrom+pWLoop) */
+        i8 isOrdered = pFrom->isOrdered;  /* isOrdered for (pFrom+pWLoop) */
+        Bitmask maskNew;                  /* Mask of src visited by (..) */
+        Bitmask revMask = 0;              /* Mask of rev-order loops for (..) */
+
+        if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 && pFrom->nRow<10 ){
+          /* Do not use an automatic index if the this loop is expected
+          ** to run less than 2 times. */
+          assert( 10==sqlite3LogEst(2) );
+          continue;
         }
-        /* Loop through table entries that match term pOrTerm. */
-        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
-                        WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY |
-                        WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY);
-        if( pSubWInfo ){
-          explainOneScan(
-              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
-          );
-          if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
-            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
-            int r;
-            r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, 
-                                         regRowid);
-            sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset,
-                                 sqlite3VdbeCurrentAddr(v)+2, r, iSet);
+        /* At this point, pWLoop is a candidate to be the next loop. 
+        ** Compute its cost */
+        rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
+        rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted);
+        nOut = pFrom->nRow + pWLoop->nOut;
+        maskNew = pFrom->maskLoop | pWLoop->maskSelf;
+        if( isOrdered<0 ){
+          isOrdered = wherePathSatisfiesOrderBy(pWInfo,
+                       pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
+                       iLoop, pWLoop, &revMask);
+        }else{
+          revMask = pFrom->revLoop;
+        }
+        if( isOrdered>=0 && isOrdered<nOrderBy ){
+          if( aSortCost[isOrdered]==0 ){
+            aSortCost[isOrdered] = whereSortingCost(
+                pWInfo, nRowEst, nOrderBy, isOrdered
+            );
           }
-          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+          rCost = sqlite3LogEstAdd(rUnsorted, aSortCost[isOrdered]);
 
-          /* The pSubWInfo->untestedTerms flag means that this OR term
-          ** contained one or more AND term from a notReady table.  The
-          ** terms from the notReady table could not be tested and will
-          ** need to be tested later.
-          */
-          if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+          WHERETRACE(0x002,
+              ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n",
+               aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, 
+               rUnsorted, rCost));
+        }else{
+          rCost = rUnsorted;
+        }
 
-          /* Finish the loop through table entries that match term pOrTerm. */
-          sqlite3WhereEnd(pSubWInfo);
+        /* Check to see if pWLoop should be added to the set of
+        ** mxChoice best-so-far paths.
+        **
+        ** First look for an existing path among best-so-far paths
+        ** that covers the same set of loops and has the same isOrdered
+        ** setting as the current path candidate.
+        **
+        ** The term "((pTo->isOrdered^isOrdered)&0x80)==0" is equivalent
+        ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range
+        ** of legal values for isOrdered, -1..64.
+        */
+        for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){
+          if( pTo->maskLoop==maskNew
+           && ((pTo->isOrdered^isOrdered)&0x80)==0
+          ){
+            testcase( jj==nTo-1 );
+            break;
+          }
+        }
+        if( jj>=nTo ){
+          /* None of the existing best-so-far paths match the candidate. */
+          if( nTo>=mxChoice
+           && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted))
+          ){
+            /* The current candidate is no better than any of the mxChoice
+            ** paths currently in the best-so-far buffer.  So discard
+            ** this candidate as not viable. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+            }
+#endif
+            continue;
+          }
+          /* If we reach this points it means that the new candidate path
+          ** needs to be added to the set of best-so-far paths. */
+          if( nTo<mxChoice ){
+            /* Increase the size of the aTo set by one */
+            jj = nTo++;
+          }else{
+            /* New path replaces the prior worst to keep count below mxChoice */
+            jj = mxI;
+          }
+          pTo = &aTo[jj];
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                isOrdered>=0 ? isOrdered+'0' : '?');
+          }
+#endif
+        }else{
+          /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
+          ** same set of loops and has the sam isOrdered setting as the
+          ** candidate path.  Check to see if the candidate should replace
+          ** pTo or if the candidate should be skipped */
+          if( pTo->rCost<rCost || (pTo->rCost==rCost && pTo->nRow<=nOut) ){
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf(
+                  "Skip   %s cost=%-3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
+                  wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                  pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+            }
+#endif
+            /* Discard the candidate path from further consideration */
+            testcase( pTo->rCost==rCost );
+            continue;
+          }
+          testcase( pTo->rCost==rCost+1 );
+          /* Control reaches here if the candidate path is better than the
+          ** pTo path.  Replace pTo with the candidate. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf(
+                "Update %s cost=%-3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                isOrdered>=0 ? isOrdered+'0' : '?');
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+          }
+#endif
+        }
+        /* pWLoop is a winner.  Add it to the set of best so far */
+        pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
+        pTo->revLoop = revMask;
+        pTo->nRow = nOut;
+        pTo->rCost = rCost;
+        pTo->rUnsorted = rUnsorted;
+        pTo->isOrdered = isOrdered;
+        memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
+        pTo->aLoop[iLoop] = pWLoop;
+        if( nTo>=mxChoice ){
+          mxI = 0;
+          mxCost = aTo[0].rCost;
+          mxUnsorted = aTo[0].nRow;
+          for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){
+            if( pTo->rCost>mxCost 
+             || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) 
+            ){
+              mxCost = pTo->rCost;
+              mxUnsorted = pTo->rUnsorted;
+              mxI = jj;
+            }
+          }
         }
       }
     }
-    sqlite3DbFree(pParse->db, pAndExpr);
-    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
-    sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
-    sqlite3VdbeResolveLabel(v, iLoopBody);
 
-    if( pWInfo->nLevel>1 ) sqlite3StackFree(pParse->db, pOrTab);
-    if( !untestedTerms ) disableTerm(pLevel, pTerm);
-  }else
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+#ifdef WHERETRACE_ENABLED  /* >=2 */
+    if( sqlite3WhereTrace & 0x02 ){
+      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
+      for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
+        sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
+           wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
+        if( pTo->isOrdered>0 ){
+          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
+        }else{
+          sqlite3DebugPrintf("\n");
+        }
+      }
+    }
+#endif
 
-  {
-    /* Case 5:  There is no usable index.  We must do a complete
-    **          scan of the entire table.
-    */
-    static const u8 aStep[] = { OP_Next, OP_Prev };
-    static const u8 aStart[] = { OP_Rewind, OP_Last };
-    assert( bRev==0 || bRev==1 );
-    assert( omitTable==0 );
-    pLevel->op = aStep[bRev];
-    pLevel->p1 = iCur;
-    pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
-    pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    /* Swap the roles of aFrom and aTo for the next generation */
+    pFrom = aTo;
+    aTo = aFrom;
+    aFrom = pFrom;
+    nFrom = nTo;
   }
-  notReady &= ~getMask(pWC->pMaskSet, iCur);
 
-  /* Insert code to test every subexpression that can be completely
-  ** computed using the current set of tables.
-  **
-  ** IMPLEMENTATION-OF: R-49525-50935 Terms that cannot be satisfied through
-  ** the use of indices become tests that are evaluated against each row of
-  ** the relevant input tables.
-  */
-  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE;
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* IMP: R-30575-11662 */
-    testcase( pTerm->wtFlags & TERM_CODED );
-    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( (pTerm->prereqAll & notReady)!=0 ){
-      testcase( pWInfo->untestedTerms==0
-               && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
-      pWInfo->untestedTerms = 1;
-      continue;
-    }
-    pE = pTerm->pExpr;
-    assert( pE!=0 );
-    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
-      continue;
+  if( nFrom==0 ){
+    sqlite3ErrorMsg(pParse, "no query solution");
+    sqlite3DbFree(db, pSpace);
+    return SQLITE_ERROR;
+  }
+  
+  /* Find the lowest cost path.  pFrom will be left pointing to that path */
+  pFrom = aFrom;
+  for(ii=1; ii<nFrom; ii++){
+    if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
+  }
+  assert( pWInfo->nLevel==nLoop );
+  /* Load the lowest cost path into pWInfo */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    WhereLevel *pLevel = pWInfo->a + iLoop;
+    pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
+    pLevel->iFrom = pWLoop->iTab;
+    pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
+  }
+  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
+   && nRowEst
+  ){
+    Bitmask notUsed;
+    int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pDistinctSet, pFrom,
+                 WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], &notUsed);
+    if( rc==pWInfo->pDistinctSet->nExpr ){
+      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
     }
-    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
-    pTerm->wtFlags |= TERM_CODED;
   }
-
-  /* For a LEFT OUTER JOIN, generate code that will record the fact that
-  ** at least one row of the right table has matched the left table.  
-  */
-  if( pLevel->iLeftJoin ){
-    pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
-    VdbeComment((v, "record LEFT JOIN hit"));
-    sqlite3ExprCacheClear(pParse);
-    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
-      testcase( pTerm->wtFlags & TERM_VIRTUAL );  /* IMP: R-30575-11662 */
-      testcase( pTerm->wtFlags & TERM_CODED );
-      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-      if( (pTerm->prereqAll & notReady)!=0 ){
-        assert( pWInfo->untestedTerms );
-        continue;
+  if( pWInfo->pOrderBy ){
+    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
+      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
+        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+      }
+    }else{
+      pWInfo->nOBSat = pFrom->isOrdered;
+      pWInfo->revMask = pFrom->revLoop;
+      if( pWInfo->nOBSat<=0 ){
+        pWInfo->nOBSat = 0;
+        if( nLoop>0 && (pFrom->aLoop[nLoop-1]->wsFlags & WHERE_ONEROW)==0 ){
+          Bitmask m = 0;
+          int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,
+                      WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);
+          if( rc==pWInfo->pOrderBy->nExpr ){
+            pWInfo->bOrderedInnerLoop = 1;
+            pWInfo->revMask = m;
+          }
+        }
+      }
+    }
+    if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
+        && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
+    ){
+      Bitmask revMask = 0;
+      int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 
+          pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask
+      );
+      assert( pWInfo->sorted==0 );
+      if( nOrder==pWInfo->pOrderBy->nExpr ){
+        pWInfo->sorted = 1;
+        pWInfo->revMask = revMask;
       }
-      assert( pTerm->pExpr );
-      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
-      pTerm->wtFlags |= TERM_CODED;
     }
   }
-  sqlite3ReleaseTempReg(pParse, iReleaseReg);
-
-  return notReady;
-}
 
-#if defined(SQLITE_TEST)
-/*
-** The following variable holds a text description of query plan generated
-** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
-** overwrites the previous.  This information is used for testing and
-** analysis only.
-*/
-SQLITE_API char sqlite3_query_plan[BMS*2*40];  /* Text of the join */
-static int nQPlan = 0;              /* Next free slow in _query_plan[] */
 
-#endif /* SQLITE_TEST */
+  pWInfo->nRowOut = pFrom->nRow;
 
+  /* Free temporary memory and return success */
+  sqlite3DbFree(db, pSpace);
+  return SQLITE_OK;
+}
 
 /*
-** Free a WhereInfo structure
+** Most queries use only a single table (they are not joins) and have
+** simple == constraints against indexed fields.  This routine attempts
+** to plan those simple cases using much less ceremony than the
+** general-purpose query planner, and thereby yield faster sqlite3_prepare()
+** times for the common case.
+**
+** Return non-zero on success, if this query can be handled by this
+** no-frills query planner.  Return zero if this query needs the 
+** general-purpose query planner.
 */
-static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
-  if( ALWAYS(pWInfo) ){
-    int i;
-    for(i=0; i<pWInfo->nLevel; i++){
-      sqlite3_index_info *pInfo = pWInfo->a[i].pIdxInfo;
-      if( pInfo ){
-        /* assert( pInfo->needToFreeIdxStr==0 || db->mallocFailed ); */
-        if( pInfo->needToFreeIdxStr ){
-          sqlite3_free(pInfo->idxStr);
-        }
-        sqlite3DbFree(db, pInfo);
-      }
-      if( pWInfo->a[i].plan.wsFlags & WHERE_TEMP_INDEX ){
-        Index *pIdx = pWInfo->a[i].plan.u.pIdx;
-        if( pIdx ){
-          sqlite3DbFree(db, pIdx->zColAff);
-          sqlite3DbFree(db, pIdx);
-        }
-      }
+static int whereShortCut(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo;
+  struct SrcList_item *pItem;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  WhereLoop *pLoop;
+  int iCur;
+  int j;
+  Table *pTab;
+  Index *pIdx;
+
+  pWInfo = pBuilder->pWInfo;
+  if( pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE ) return 0;
+  assert( pWInfo->pTabList->nSrc>=1 );
+  pItem = pWInfo->pTabList->a;
+  pTab = pItem->pTab;
+  if( IsVirtual(pTab) ) return 0;
+  if( pItem->fg.isIndexedBy ) return 0;
+  iCur = pItem->iCursor;
+  pWC = &pWInfo->sWC;
+  pLoop = pBuilder->pNew;
+  pLoop->wsFlags = 0;
+  pLoop->nSkip = 0;
+  pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
+  if( pTerm ){
+    testcase( pTerm->eOperator & WO_IS );
+    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
+    pLoop->aLTerm[0] = pTerm;
+    pLoop->nLTerm = 1;
+    pLoop->u.btree.nEq = 1;
+    /* TUNING: Cost of a rowid lookup is 10 */
+    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
+  }else{
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      int opMask;
+      assert( pLoop->aLTermSpace==pLoop->aLTerm );
+      if( !IsUniqueIndex(pIdx)
+       || pIdx->pPartIdxWhere!=0 
+       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
+      ) continue;
+      opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;
+      for(j=0; j<pIdx->nKeyCol; j++){
+        pTerm = sqlite3WhereFindTerm(pWC, iCur, j, 0, opMask, pIdx);
+        if( pTerm==0 ) break;
+        testcase( pTerm->eOperator & WO_IS );
+        pLoop->aLTerm[j] = pTerm;
+      }
+      if( j!=pIdx->nKeyCol ) continue;
+      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
+      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
+        pLoop->wsFlags |= WHERE_IDX_ONLY;
+      }
+      pLoop->nLTerm = j;
+      pLoop->u.btree.nEq = j;
+      pLoop->u.btree.pIndex = pIdx;
+      /* TUNING: Cost of a unique index lookup is 15 */
+      pLoop->rRun = 39;  /* 39==sqlite3LogEst(15) */
+      break;
     }
-    whereClauseClear(pWInfo->pWC);
-    sqlite3DbFree(db, pWInfo);
   }
+  if( pLoop->wsFlags ){
+    pLoop->nOut = (LogEst)1;
+    pWInfo->a[0].pWLoop = pLoop;
+    pLoop->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+    pWInfo->a[0].iTabCur = iCur;
+    pWInfo->nRowOut = 1;
+    if( pWInfo->pOrderBy ) pWInfo->nOBSat =  pWInfo->pOrderBy->nExpr;
+    if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+#ifdef SQLITE_DEBUG
+    pLoop->cId = '0';
+#endif
+    return 1;
+  }
+  return 0;
 }
 
-
 /*
 ** Generate the beginning of the loop used for WHERE clause processing.
 ** The return value is a pointer to an opaque structure that contains
@@ -105268,40 +130875,66 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
 **
 ** ORDER BY CLAUSE PROCESSING
 **
-** *ppOrderBy is a pointer to the ORDER BY clause of a SELECT statement,
+** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
+** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
 ** if there is one.  If there is no ORDER BY clause or if this routine
-** is called from an UPDATE or DELETE statement, then ppOrderBy is NULL.
-**
-** If an index can be used so that the natural output order of the table
-** scan is correct for the ORDER BY clause, then that index is used and
-** *ppOrderBy is set to NULL.  This is an optimization that prevents an
-** unnecessary sort of the result set if an index appropriate for the
-** ORDER BY clause already exists.
-**
-** If the where clause loops cannot be arranged to provide the correct
-** output order, then the *ppOrderBy is unchanged.
+** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
+**
+** The iIdxCur parameter is the cursor number of an index.  If 
+** WHERE_OR_SUBCLAUSE is set, iIdxCur is the cursor number of an index
+** to use for OR clause processing.  The WHERE clause should use this
+** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
+** the first cursor in an array of cursors for all indices.  iIdxCur should
+** be used to compute the appropriate cursor depending on which index is
+** used.
 */
 SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
-  Parse *pParse,        /* The parser context */
-  SrcList *pTabList,    /* A list of all tables to be scanned */
-  Expr *pWhere,         /* The WHERE clause */
-  ExprList **ppOrderBy, /* An ORDER BY clause, or NULL */
-  ExprList *pDistinct,  /* The select-list for DISTINCT queries - or NULL */
-  u16 wctrlFlags        /* One of the WHERE_* flags defined in sqliteInt.h */
+  Parse *pParse,          /* The parser context */
+  SrcList *pTabList,      /* FROM clause: A list of all tables to be scanned */
+  Expr *pWhere,           /* The WHERE clause */
+  ExprList *pOrderBy,     /* An ORDER BY (or GROUP BY) clause, or NULL */
+  ExprList *pDistinctSet, /* Try not to output two rows that duplicate these */
+  u16 wctrlFlags,         /* The WHERE_* flags defined in sqliteInt.h */
+  int iAuxArg             /* If WHERE_OR_SUBCLAUSE is set, index cursor number
+                          ** If WHERE_USE_LIMIT, then the limit amount */
 ){
-  int i;                     /* Loop counter */
   int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
   int nTabList;              /* Number of elements in pTabList */
   WhereInfo *pWInfo;         /* Will become the return value of this function */
   Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
   Bitmask notReady;          /* Cursors that are not yet positioned */
+  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
   WhereMaskSet *pMaskSet;    /* The expression mask set */
-  WhereClause *pWC;               /* Decomposition of the WHERE clause */
-  struct SrcList_item *pTabItem;  /* A single entry from pTabList */
-  WhereLevel *pLevel;             /* A single level in the pWInfo list */
-  int iFrom;                      /* First unused FROM clause element */
-  int andFlags;              /* AND-ed combination of all pWC->a[].wtFlags */
+  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
+  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
+  int ii;                    /* Loop counter */
   sqlite3 *db;               /* Database connection */
+  int rc;                    /* Return code */
+  u8 bFordelete = 0;         /* OPFLAG_FORDELETE or zero, as appropriate */
+
+  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
+        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
+     && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 
+  ));
+
+  /* Only one of WHERE_OR_SUBCLAUSE or WHERE_USE_LIMIT */
+  assert( (wctrlFlags & WHERE_OR_SUBCLAUSE)==0
+            || (wctrlFlags & WHERE_USE_LIMIT)==0 );
+
+  /* Variable initialization */
+  db = pParse->db;
+  memset(&sWLB, 0, sizeof(sWLB));
+
+  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
+  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
+  if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0;
+  sWLB.pOrderBy = pOrderBy;
+
+  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+    wctrlFlags &= ~WHERE_WANT_DISTINCT;
+  }
 
   /* The number of tables in the FROM clause is limited by the number of
   ** bits in a Bitmask 
@@ -105313,11 +130946,11 @@ SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
   }
 
   /* This function normally generates a nested loop for all tables in 
-  ** pTabList.  But if the WHERE_ONETABLE_ONLY flag is set, then we should
+  ** pTabList.  But if the WHERE_OR_SUBCLAUSE flag is set, then we should
   ** only generate code for the first table in pTabList and assume that
   ** any cursors associated with subsequent tables are uninitialized.
   */
-  nTabList = (wctrlFlags & WHERE_ONETABLE_ONLY) ? 1 : pTabList->nSrc;
+  nTabList = (wctrlFlags & WHERE_OR_SUBCLAUSE) ? 1 : pTabList->nSrc;
 
   /* Allocate and initialize the WhereInfo structure that will become the
   ** return value. A single allocation is used to store the WhereInfo
@@ -105326,397 +130959,345 @@ SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
   ** field (type Bitmask) it must be aligned on an 8-byte boundary on
   ** some architectures. Hence the ROUND8() below.
   */
-  db = pParse->db;
   nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
-  pWInfo = sqlite3DbMallocZero(db, 
-      nByteWInfo + 
-      sizeof(WhereClause) +
-      sizeof(WhereMaskSet)
-  );
+  pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
   if( db->mallocFailed ){
     sqlite3DbFree(db, pWInfo);
     pWInfo = 0;
     goto whereBeginError;
   }
+  pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;
   pWInfo->nLevel = nTabList;
   pWInfo->pParse = pParse;
   pWInfo->pTabList = pTabList;
-  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
-  pWInfo->pWC = pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
+  pWInfo->pOrderBy = pOrderBy;
+  pWInfo->pDistinctSet = pDistinctSet;
+  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
   pWInfo->wctrlFlags = wctrlFlags;
+  pWInfo->iLimit = iAuxArg;
   pWInfo->savedNQueryLoop = pParse->nQueryLoop;
-  pMaskSet = (WhereMaskSet*)&pWC[1];
-
-  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
-  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
-  if( db->flags & SQLITE_DistinctOpt ) pDistinct = 0;
+  assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */
+  pMaskSet = &pWInfo->sMaskSet;
+  sWLB.pWInfo = pWInfo;
+  sWLB.pWC = &pWInfo->sWC;
+  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
+  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
+  whereLoopInit(sWLB.pNew);
+#ifdef SQLITE_DEBUG
+  sWLB.pNew->cId = '*';
+#endif
 
   /* Split the WHERE clause into separate subexpressions where each
   ** subexpression is separated by an AND operator.
   */
   initMaskSet(pMaskSet);
-  whereClauseInit(pWC, pParse, pMaskSet, wctrlFlags);
-  sqlite3ExprCodeConstants(pParse, pWhere);
-  whereSplit(pWC, pWhere, TK_AND);   /* IMP: R-15842-53296 */
+  sqlite3WhereClauseInit(&pWInfo->sWC, pWInfo);
+  sqlite3WhereSplit(&pWInfo->sWC, pWhere, TK_AND);
     
   /* Special case: a WHERE clause that is constant.  Evaluate the
   ** expression and either jump over all of the code or fall thru.
   */
-  if( pWhere && (nTabList==0 || sqlite3ExprIsConstantNotJoin(pWhere)) ){
-    sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, SQLITE_JUMPIFNULL);
-    pWhere = 0;
+  for(ii=0; ii<sWLB.pWC->nTerm; ii++){
+    if( nTabList==0 || sqlite3ExprIsConstantNotJoin(sWLB.pWC->a[ii].pExpr) ){
+      sqlite3ExprIfFalse(pParse, sWLB.pWC->a[ii].pExpr, pWInfo->iBreak,
+                         SQLITE_JUMPIFNULL);
+      sWLB.pWC->a[ii].wtFlags |= TERM_CODED;
+    }
+  }
+
+  /* Special case: No FROM clause
+  */
+  if( nTabList==0 ){
+    if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
+    if( wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
   }
 
   /* Assign a bit from the bitmask to every term in the FROM clause.
   **
-  ** When assigning bitmask values to FROM clause cursors, it must be
-  ** the case that if X is the bitmask for the N-th FROM clause term then
-  ** the bitmask for all FROM clause terms to the left of the N-th term
-  ** is (X-1).   An expression from the ON clause of a LEFT JOIN can use
-  ** its Expr.iRightJoinTable value to find the bitmask of the right table
-  ** of the join.  Subtracting one from the right table bitmask gives a
-  ** bitmask for all tables to the left of the join.  Knowing the bitmask
-  ** for all tables to the left of a left join is important.  Ticket #3015.
+  ** The N-th term of the FROM clause is assigned a bitmask of 1<<N.
   **
-  ** Configure the WhereClause.vmask variable so that bits that correspond
-  ** to virtual table cursors are set. This is used to selectively disable 
-  ** the OR-to-IN transformation in exprAnalyzeOrTerm(). It is not helpful 
-  ** with virtual tables.
+  ** The rule of the previous sentence ensures thta if X is the bitmask for
+  ** a table T, then X-1 is the bitmask for all other tables to the left of T.
+  ** Knowing the bitmask for all tables to the left of a left join is
+  ** important.  Ticket #3015.
   **
   ** Note that bitmasks are created for all pTabList->nSrc tables in
   ** pTabList, not just the first nTabList tables.  nTabList is normally
   ** equal to pTabList->nSrc but might be shortened to 1 if the
-  ** WHERE_ONETABLE_ONLY flag is set.
+  ** WHERE_OR_SUBCLAUSE flag is set.
   */
-  assert( pWC->vmask==0 && pMaskSet->n==0 );
-  for(i=0; i<pTabList->nSrc; i++){
-    createMask(pMaskSet, pTabList->a[i].iCursor);
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    if( ALWAYS(pTabList->a[i].pTab) && IsVirtual(pTabList->a[i].pTab) ){
-      pWC->vmask |= ((Bitmask)1 << i);
-    }
-#endif
+  for(ii=0; ii<pTabList->nSrc; ii++){
+    createMask(pMaskSet, pTabList->a[ii].iCursor);
+    sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
   }
-#ifndef NDEBUG
-  {
-    Bitmask toTheLeft = 0;
-    for(i=0; i<pTabList->nSrc; i++){
-      Bitmask m = getMask(pMaskSet, pTabList->a[i].iCursor);
-      assert( (m-1)==toTheLeft );
-      toTheLeft |= m;
-    }
+#ifdef SQLITE_DEBUG
+  for(ii=0; ii<pTabList->nSrc; ii++){
+    Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
+    assert( m==MASKBIT(ii) );
   }
 #endif
 
-  /* Analyze all of the subexpressions.  Note that exprAnalyze() might
-  ** add new virtual terms onto the end of the WHERE clause.  We do not
-  ** want to analyze these virtual terms, so start analyzing at the end
-  ** and work forward so that the added virtual terms are never processed.
-  */
-  exprAnalyzeAll(pTabList, pWC);
-  if( db->mallocFailed ){
-    goto whereBeginError;
-  }
+  /* Analyze all of the subexpressions. */
+  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
+  if( db->mallocFailed ) goto whereBeginError;
 
-  /* Check if the DISTINCT qualifier, if there is one, is redundant. 
-  ** If it is, then set pDistinct to NULL and WhereInfo.eDistinct to
-  ** WHERE_DISTINCT_UNIQUE to tell the caller to ignore the DISTINCT.
-  */
-  if( pDistinct && isDistinctRedundant(pParse, pTabList, pWC, pDistinct) ){
-    pDistinct = 0;
-    pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+  if( wctrlFlags & WHERE_WANT_DISTINCT ){
+    if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pDistinctSet) ){
+      /* The DISTINCT marking is pointless.  Ignore it. */
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }else if( pOrderBy==0 ){
+      /* Try to ORDER BY the result set to make distinct processing easier */
+      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
+      pWInfo->pOrderBy = pDistinctSet;
+    }
   }
 
-  /* Chose the best index to use for each table in the FROM clause.
-  **
-  ** This loop fills in the following fields:
-  **
-  **   pWInfo->a[].pIdx      The index to use for this level of the loop.
-  **   pWInfo->a[].wsFlags   WHERE_xxx flags associated with pIdx
-  **   pWInfo->a[].nEq       The number of == and IN constraints
-  **   pWInfo->a[].iFrom     Which term of the FROM clause is being coded
-  **   pWInfo->a[].iTabCur   The VDBE cursor for the database table
-  **   pWInfo->a[].iIdxCur   The VDBE cursor for the index
-  **   pWInfo->a[].pTerm     When wsFlags==WO_OR, the OR-clause term
-  **
-  ** This loop also figures out the nesting order of tables in the FROM
-  ** clause.
-  */
-  notReady = ~(Bitmask)0;
-  andFlags = ~0;
-  WHERETRACE(("*** Optimizer Start ***\n"));
-  for(i=iFrom=0, pLevel=pWInfo->a; i<nTabList; i++, pLevel++){
-    WhereCost bestPlan;         /* Most efficient plan seen so far */
-    Index *pIdx;                /* Index for FROM table at pTabItem */
-    int j;                      /* For looping over FROM tables */
-    int bestJ = -1;             /* The value of j */
-    Bitmask m;                  /* Bitmask value for j or bestJ */
-    int isOptimal;              /* Iterator for optimal/non-optimal search */
-    int nUnconstrained;         /* Number tables without INDEXED BY */
-    Bitmask notIndexed;         /* Mask of tables that cannot use an index */
-
-    memset(&bestPlan, 0, sizeof(bestPlan));
-    bestPlan.rCost = SQLITE_BIG_DBL;
-    WHERETRACE(("*** Begin search for loop %d ***\n", i));
-
-    /* Loop through the remaining entries in the FROM clause to find the
-    ** next nested loop. The loop tests all FROM clause entries
-    ** either once or twice. 
-    **
-    ** The first test is always performed if there are two or more entries
-    ** remaining and never performed if there is only one FROM clause entry
-    ** to choose from.  The first test looks for an "optimal" scan.  In
-    ** this context an optimal scan is one that uses the same strategy
-    ** for the given FROM clause entry as would be selected if the entry
-    ** were used as the innermost nested loop.  In other words, a table
-    ** is chosen such that the cost of running that table cannot be reduced
-    ** by waiting for other tables to run first.  This "optimal" test works
-    ** by first assuming that the FROM clause is on the inner loop and finding
-    ** its query plan, then checking to see if that query plan uses any
-    ** other FROM clause terms that are notReady.  If no notReady terms are
-    ** used then the "optimal" query plan works.
-    **
-    ** Note that the WhereCost.nRow parameter for an optimal scan might
-    ** not be as small as it would be if the table really were the innermost
-    ** join.  The nRow value can be reduced by WHERE clause constraints
-    ** that do not use indices.  But this nRow reduction only happens if the
-    ** table really is the innermost join.  
-    **
-    ** The second loop iteration is only performed if no optimal scan
-    ** strategies were found by the first iteration. This second iteration
-    ** is used to search for the lowest cost scan overall.
-    **
-    ** Previous versions of SQLite performed only the second iteration -
-    ** the next outermost loop was always that with the lowest overall
-    ** cost. However, this meant that SQLite could select the wrong plan
-    ** for scripts such as the following:
-    **   
-    **   CREATE TABLE t1(a, b); 
-    **   CREATE TABLE t2(c, d);
-    **   SELECT * FROM t2, t1 WHERE t2.rowid = t1.a;
-    **
-    ** The best strategy is to iterate through table t1 first. However it
-    ** is not possible to determine this with a simple greedy algorithm.
-    ** Since the cost of a linear scan through table t2 is the same 
-    ** as the cost of a linear scan through table t1, a simple greedy 
-    ** algorithm may choose to use t2 for the outer loop, which is a much
-    ** costlier approach.
-    */
-    nUnconstrained = 0;
-    notIndexed = 0;
-    for(isOptimal=(iFrom<nTabList-1); isOptimal>=0 && bestJ<0; isOptimal--){
-      Bitmask mask;             /* Mask of tables not yet ready */
-      for(j=iFrom, pTabItem=&pTabList->a[j]; j<nTabList; j++, pTabItem++){
-        int doNotReorder;    /* True if this table should not be reordered */
-        WhereCost sCost;     /* Cost information from best[Virtual]Index() */
-        ExprList *pOrderBy;  /* ORDER BY clause for index to optimize */
-        ExprList *pDist;     /* DISTINCT clause for index to optimize */
-  
-        doNotReorder =  (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0;
-        if( j!=iFrom && doNotReorder ) break;
-        m = getMask(pMaskSet, pTabItem->iCursor);
-        if( (m & notReady)==0 ){
-          if( j==iFrom ) iFrom++;
-          continue;
-        }
-        mask = (isOptimal ? m : notReady);
-        pOrderBy = ((i==0 && ppOrderBy )?*ppOrderBy:0);
-        pDist = (i==0 ? pDistinct : 0);
-        if( pTabItem->pIndex==0 ) nUnconstrained++;
-  
-        WHERETRACE(("=== trying table %d with isOptimal=%d ===\n",
-                    j, isOptimal));
-        assert( pTabItem->pTab );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-        if( IsVirtual(pTabItem->pTab) ){
-          sqlite3_index_info **pp = &pWInfo->a[j].pIdxInfo;
-          bestVirtualIndex(pParse, pWC, pTabItem, mask, notReady, pOrderBy,
-                           &sCost, pp);
-        }else 
+  /* Construct the WhereLoop objects */
+#if defined(WHERETRACE_ENABLED)
+  if( sqlite3WhereTrace & 0xffff ){
+    sqlite3DebugPrintf("*** Optimizer Start *** (wctrlFlags: 0x%x",wctrlFlags);
+    if( wctrlFlags & WHERE_USE_LIMIT ){
+      sqlite3DebugPrintf(", limit: %d", iAuxArg);
+    }
+    sqlite3DebugPrintf(")\n");
+  }
+  if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */
+    sqlite3WhereClausePrint(sWLB.pWC);
+  }
 #endif
-        {
-          bestBtreeIndex(pParse, pWC, pTabItem, mask, notReady, pOrderBy,
-              pDist, &sCost);
-        }
-        assert( isOptimal || (sCost.used&notReady)==0 );
-
-        /* If an INDEXED BY clause is present, then the plan must use that
-        ** index if it uses any index at all */
-        assert( pTabItem->pIndex==0 
-                  || (sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0
-                  || sCost.plan.u.pIdx==pTabItem->pIndex );
 
-        if( isOptimal && (sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){
-          notIndexed |= m;
-        }
-
-        /* Conditions under which this table becomes the best so far:
-        **
-        **   (1) The table must not depend on other tables that have not
-        **       yet run.
-        **
-        **   (2) A full-table-scan plan cannot supercede indexed plan unless
-        **       the full-table-scan is an "optimal" plan as defined above.
-        **
-        **   (3) All tables have an INDEXED BY clause or this table lacks an
-        **       INDEXED BY clause or this table uses the specific
-        **       index specified by its INDEXED BY clause.  This rule ensures
-        **       that a best-so-far is always selected even if an impossible
-        **       combination of INDEXED BY clauses are given.  The error
-        **       will be detected and relayed back to the application later.
-        **       The NEVER() comes about because rule (2) above prevents
-        **       An indexable full-table-scan from reaching rule (3).
-        **
-        **   (4) The plan cost must be lower than prior plans or else the
-        **       cost must be the same and the number of rows must be lower.
-        */
-        if( (sCost.used&notReady)==0                       /* (1) */
-            && (bestJ<0 || (notIndexed&m)!=0               /* (2) */
-                || (bestPlan.plan.wsFlags & WHERE_NOT_FULLSCAN)==0
-                || (sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0)
-            && (nUnconstrained==0 || pTabItem->pIndex==0   /* (3) */
-                || NEVER((sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0))
-            && (bestJ<0 || sCost.rCost<bestPlan.rCost      /* (4) */
-                || (sCost.rCost<=bestPlan.rCost 
-                 && sCost.plan.nRow<bestPlan.plan.nRow))
-        ){
-          WHERETRACE(("=== table %d is best so far"
-                      " with cost=%g and nRow=%g\n",
-                      j, sCost.rCost, sCost.plan.nRow));
-          bestPlan = sCost;
-          bestJ = j;
-        }
-        if( doNotReorder ) break;
-      }
-    }
-    assert( bestJ>=0 );
-    assert( notReady & getMask(pMaskSet, pTabList->a[bestJ].iCursor) );
-    WHERETRACE(("*** Optimizer selects table %d for loop %d"
-                " with cost=%g and nRow=%g\n",
-                bestJ, pLevel-pWInfo->a, bestPlan.rCost, bestPlan.plan.nRow));
-    /* The ALWAYS() that follows was added to hush up clang scan-build */
-    if( (bestPlan.plan.wsFlags & WHERE_ORDERBY)!=0 && ALWAYS(ppOrderBy) ){
-      *ppOrderBy = 0;
-    }
-    if( (bestPlan.plan.wsFlags & WHERE_DISTINCT)!=0 ){
-      assert( pWInfo->eDistinct==0 );
-      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+  if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
+    rc = whereLoopAddAll(&sWLB);
+    if( rc ) goto whereBeginError;
+  
+#ifdef WHERETRACE_ENABLED
+    if( sqlite3WhereTrace ){    /* Display all of the WhereLoop objects */
+      WhereLoop *p;
+      int i;
+      static const char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
+                                             "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+        p->cId = zLabel[i%sizeof(zLabel)];
+        whereLoopPrint(p, sWLB.pWC);
+      }
     }
-    andFlags &= bestPlan.plan.wsFlags;
-    pLevel->plan = bestPlan.plan;
-    testcase( bestPlan.plan.wsFlags & WHERE_INDEXED );
-    testcase( bestPlan.plan.wsFlags & WHERE_TEMP_INDEX );
-    if( bestPlan.plan.wsFlags & (WHERE_INDEXED|WHERE_TEMP_INDEX) ){
-      pLevel->iIdxCur = pParse->nTab++;
-    }else{
-      pLevel->iIdxCur = -1;
+#endif
+  
+    wherePathSolver(pWInfo, 0);
+    if( db->mallocFailed ) goto whereBeginError;
+    if( pWInfo->pOrderBy ){
+       wherePathSolver(pWInfo, pWInfo->nRowOut+1);
+       if( db->mallocFailed ) goto whereBeginError;
     }
-    notReady &= ~getMask(pMaskSet, pTabList->a[bestJ].iCursor);
-    pLevel->iFrom = (u8)bestJ;
-    if( bestPlan.plan.nRow>=(double)1 ){
-      pParse->nQueryLoop *= bestPlan.plan.nRow;
+  }
+  if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
+     pWInfo->revMask = ALLBITS;
+  }
+  if( pParse->nErr || NEVER(db->mallocFailed) ){
+    goto whereBeginError;
+  }
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace ){
+    sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
+    if( pWInfo->nOBSat>0 ){
+      sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);
     }
-
-    /* Check that if the table scanned by this loop iteration had an
-    ** INDEXED BY clause attached to it, that the named index is being
-    ** used for the scan. If not, then query compilation has failed.
-    ** Return an error.
-    */
-    pIdx = pTabList->a[bestJ].pIndex;
-    if( pIdx ){
-      if( (bestPlan.plan.wsFlags & WHERE_INDEXED)==0 ){
-        sqlite3ErrorMsg(pParse, "cannot use index: %s", pIdx->zName);
-        goto whereBeginError;
-      }else{
-        /* If an INDEXED BY clause is used, the bestIndex() function is
-        ** guaranteed to find the index specified in the INDEXED BY clause
-        ** if it find an index at all. */
-        assert( bestPlan.plan.u.pIdx==pIdx );
+    switch( pWInfo->eDistinct ){
+      case WHERE_DISTINCT_UNIQUE: {
+        sqlite3DebugPrintf("  DISTINCT=unique");
+        break;
+      }
+      case WHERE_DISTINCT_ORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=ordered");
+        break;
+      }
+      case WHERE_DISTINCT_UNORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=unordered");
+        break;
       }
     }
+    sqlite3DebugPrintf("\n");
+    for(ii=0; ii<pWInfo->nLevel; ii++){
+      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
+    }
   }
-  WHERETRACE(("*** Optimizer Finished ***\n"));
-  if( pParse->nErr || db->mallocFailed ){
-    goto whereBeginError;
-  }
-
-  /* If the total query only selects a single row, then the ORDER BY
-  ** clause is irrelevant.
-  */
-  if( (andFlags & WHERE_UNIQUE)!=0 && ppOrderBy ){
-    *ppOrderBy = 0;
+#endif
+  /* Attempt to omit tables from the join that do not effect the result */
+  if( pWInfo->nLevel>=2
+   && pDistinctSet!=0
+   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
+  ){
+    Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pDistinctSet);
+    if( sWLB.pOrderBy ){
+      tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);
+    }
+    while( pWInfo->nLevel>=2 ){
+      WhereTerm *pTerm, *pEnd;
+      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+      if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break;
+      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
+       && (pLoop->wsFlags & WHERE_ONEROW)==0
+      ){
+        break;
+      }
+      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
+      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
+      for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){
+        if( (pTerm->prereqAll & pLoop->maskSelf)!=0
+         && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+        ){
+          break;
+        }
+      }
+      if( pTerm<pEnd ) break;
+      WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
+      pWInfo->nLevel--;
+      nTabList--;
+    }
   }
+  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
+  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
 
   /* If the caller is an UPDATE or DELETE statement that is requesting
   ** to use a one-pass algorithm, determine if this is appropriate.
-  ** The one-pass algorithm only works if the WHERE clause constraints
-  ** the statement to update a single row.
   */
   assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
-  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){
-    pWInfo->okOnePass = 1;
-    pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
+  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
+    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
+    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
+    if( bOnerow
+     || ((wctrlFlags & WHERE_ONEPASS_MULTIROW)!=0
+           && 0==(wsFlags & WHERE_VIRTUALTABLE))
+    ){
+      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
+      if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){
+        if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){
+          bFordelete = OPFLAG_FORDELETE;
+        }
+        pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);
+      }
+    }
   }
 
   /* Open all tables in the pTabList and any indices selected for
   ** searching those tables.
   */
-  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
-  notReady = ~(Bitmask)0;
-  pWInfo->nRowOut = (double)1;
-  for(i=0, pLevel=pWInfo->a; i<nTabList; i++, pLevel++){
+  for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
     Table *pTab;     /* Table to open */
     int iDb;         /* Index of database containing table/index */
+    struct SrcList_item *pTabItem;
 
     pTabItem = &pTabList->a[pLevel->iFrom];
     pTab = pTabItem->pTab;
-    pLevel->iTabCur = pTabItem->iCursor;
-    pWInfo->nRowOut *= pLevel->plan.nRow;
     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    pLoop = pLevel->pWLoop;
     if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
       /* Do nothing */
     }else
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-    if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
       int iCur = pTabItem->iCursor;
       sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
+    }else if( IsVirtual(pTab) ){
+      /* noop */
     }else
 #endif
-    if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
-         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
-      int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
+    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+         && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){
+      int op = OP_OpenRead;
+      if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
+      };
       sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
-      testcase( pTab->nCol==BMS-1 );
-      testcase( pTab->nCol==BMS );
-      if( !pWInfo->okOnePass && pTab->nCol<BMS ){
+      assert( pTabItem->iCursor==pLevel->iTabCur );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );
+      if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol<BMS && HasRowid(pTab) ){
         Bitmask b = pTabItem->colUsed;
         int n = 0;
         for(; b; b=b>>1, n++){}
-        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
-                            SQLITE_INT_TO_PTR(n), P4_INT32);
+        sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(n), P4_INT32);
         assert( n<=pTab->nCol );
       }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+      if( pLoop->u.btree.pIndex!=0 ){
+        sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);
+      }else
+#endif
+      {
+        sqlite3VdbeChangeP5(v, bFordelete);
+      }
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+      sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,
+                            (const u8*)&pTabItem->colUsed, P4_INT64);
+#endif
     }else{
       sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
     }
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-    if( (pLevel->plan.wsFlags & WHERE_TEMP_INDEX)!=0 ){
-      constructAutomaticIndex(pParse, pWC, pTabItem, notReady, pLevel);
-    }else
-#endif
-    if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
-      Index *pIx = pLevel->plan.u.pIdx;
-      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
-      int iIdxCur = pLevel->iIdxCur;
+    if( pLoop->wsFlags & WHERE_INDEXED ){
+      Index *pIx = pLoop->u.btree.pIndex;
+      int iIndexCur;
+      int op = OP_OpenRead;
+      /* iAuxArg is always set if to a positive value if ONEPASS is possible */
+      assert( iAuxArg!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );
+      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
+       && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0
+      ){
+        /* This is one term of an OR-optimization using the PRIMARY KEY of a
+        ** WITHOUT ROWID table.  No need for a separate index */
+        iIndexCur = pLevel->iTabCur;
+        op = 0;
+      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        Index *pJ = pTabItem->pTab->pIndex;
+        iIndexCur = iAuxArg;
+        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
+        while( ALWAYS(pJ) && pJ!=pIx ){
+          iIndexCur++;
+          pJ = pJ->pNext;
+        }
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[1] = iIndexCur;
+      }else if( iAuxArg && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 ){
+        iIndexCur = iAuxArg;
+        op = OP_ReopenIdx;
+      }else{
+        iIndexCur = pParse->nTab++;
+      }
+      pLevel->iIdxCur = iIndexCur;
       assert( pIx->pSchema==pTab->pSchema );
-      assert( iIdxCur>=0 );
-      sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb,
-                        (char*)pKey, P4_KEYINFO_HANDOFF);
-      VdbeComment((v, "%s", pIx->zName));
+      assert( iIndexCur>=0 );
+      if( op ){
+        sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb);
+        sqlite3VdbeSetP4KeyInfo(pParse, pIx);
+        if( (pLoop->wsFlags & WHERE_CONSTRAINT)!=0
+         && (pLoop->wsFlags & (WHERE_COLUMN_RANGE|WHERE_SKIPSCAN))==0
+         && (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0
+        ){
+          sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Hint to COMDB2 */
+        }
+        VdbeComment((v, "%s", pIx->zName));
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+        {
+          u64 colUsed = 0;
+          int ii, jj;
+          for(ii=0; ii<pIx->nColumn; ii++){
+            jj = pIx->aiColumn[ii];
+            if( jj<0 ) continue;
+            if( jj>63 ) jj = 63;
+            if( (pTabItem->colUsed & MASKBIT(jj))==0 ) continue;
+            colUsed |= ((u64)1)<<(ii<63 ? ii : 63);
+          }
+          sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, iIndexCur, 0, 0,
+                                (u8*)&colUsed, P4_INT64);
+        }
+#endif /* SQLITE_ENABLE_COLUMN_USED_MASK */
+      }
     }
-    sqlite3CodeVerifySchema(pParse, iDb);
-    notReady &= ~getMask(pWC->pMaskSet, pTabItem->iCursor);
+    if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);
   }
   pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
   if( db->mallocFailed ) goto whereBeginError;
@@ -105726,65 +131307,31 @@ SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
   ** program.
   */
   notReady = ~(Bitmask)0;
-  for(i=0; i<nTabList; i++){
-    pLevel = &pWInfo->a[i];
-    explainOneScan(pParse, pTabList, pLevel, i, pLevel->iFrom, wctrlFlags);
-    notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady, pWhere);
-    pWInfo->iContinue = pLevel->addrCont;
-  }
-
-#ifdef SQLITE_TEST  /* For testing and debugging use only */
-  /* Record in the query plan information about the current table
-  ** and the index used to access it (if any).  If the table itself
-  ** is not used, its name is just '{}'.  If no index is used
-  ** the index is listed as "{}".  If the primary key is used the
-  ** index name is '*'.
-  */
-  for(i=0; i<nTabList; i++){
-    char *z;
-    int n;
-    pLevel = &pWInfo->a[i];
-    pTabItem = &pTabList->a[pLevel->iFrom];
-    z = pTabItem->zAlias;
-    if( z==0 ) z = pTabItem->pTab->zName;
-    n = sqlite3Strlen30(z);
-    if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
-      if( pLevel->plan.wsFlags & WHERE_IDX_ONLY ){
-        memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
-        nQPlan += 2;
-      }else{
-        memcpy(&sqlite3_query_plan[nQPlan], z, n);
-        nQPlan += n;
-      }
-      sqlite3_query_plan[nQPlan++] = ' ';
+  for(ii=0; ii<nTabList; ii++){
+    int addrExplain;
+    int wsFlags;
+    pLevel = &pWInfo->a[ii];
+    wsFlags = pLevel->pWLoop->wsFlags;
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+      constructAutomaticIndex(pParse, &pWInfo->sWC,
+                &pTabList->a[pLevel->iFrom], notReady, pLevel);
+      if( db->mallocFailed ) goto whereBeginError;
     }
-    testcase( pLevel->plan.wsFlags & WHERE_ROWID_EQ );
-    testcase( pLevel->plan.wsFlags & WHERE_ROWID_RANGE );
-    if( pLevel->plan.wsFlags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
-      memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
-      nQPlan += 2;
-    }else if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
-      n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName);
-      if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
-        memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n);
-        nQPlan += n;
-        sqlite3_query_plan[nQPlan++] = ' ';
-      }
-    }else{
-      memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
-      nQPlan += 3;
+#endif
+    addrExplain = sqlite3WhereExplainOneScan(
+        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
+    );
+    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
+    notReady = sqlite3WhereCodeOneLoopStart(pWInfo, ii, notReady);
+    pWInfo->iContinue = pLevel->addrCont;
+    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_OR_SUBCLAUSE)==0 ){
+      sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);
     }
   }
-  while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
-    sqlite3_query_plan[--nQPlan] = 0;
-  }
-  sqlite3_query_plan[nQPlan] = 0;
-  nQPlan = 0;
-#endif /* SQLITE_TEST // Testing and debugging use only */
 
-  /* Record the continuation address in the WhereInfo structure.  Then
-  ** clean up and return.
-  */
+  /* Done. */
+  VdbeModuleComment((v, "Begin WHERE-core"));
   return pWInfo;
 
   /* Jump here if malloc fails */
@@ -105805,49 +131352,73 @@ SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
   Vdbe *v = pParse->pVdbe;
   int i;
   WhereLevel *pLevel;
+  WhereLoop *pLoop;
   SrcList *pTabList = pWInfo->pTabList;
   sqlite3 *db = pParse->db;
 
   /* Generate loop termination code.
   */
+  VdbeModuleComment((v, "End WHERE-core"));
   sqlite3ExprCacheClear(pParse);
   for(i=pWInfo->nLevel-1; i>=0; i--){
+    int addr;
     pLevel = &pWInfo->a[i];
+    pLoop = pLevel->pWLoop;
     sqlite3VdbeResolveLabel(v, pLevel->addrCont);
     if( pLevel->op!=OP_Noop ){
-      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
+      sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);
       sqlite3VdbeChangeP5(v, pLevel->p5);
+      VdbeCoverage(v);
+      VdbeCoverageIf(v, pLevel->op==OP_Next);
+      VdbeCoverageIf(v, pLevel->op==OP_Prev);
+      VdbeCoverageIf(v, pLevel->op==OP_VNext);
     }
-    if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
+    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
       struct InLoop *pIn;
       int j;
       sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
       for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
         sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
-        sqlite3VdbeAddOp2(v, OP_Next, pIn->iCur, pIn->addrInTop);
+        sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
+        VdbeCoverage(v);
+        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
+        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
         sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
       }
-      sqlite3DbFree(db, pLevel->u.in.aInLoop);
     }
     sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
+    if( pLevel->addrSkip ){
+      sqlite3VdbeGoto(v, pLevel->addrSkip);
+      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
+    }
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+    if( pLevel->addrLikeRep ){
+      sqlite3VdbeAddOp2(v, OP_DecrJumpZero, (int)(pLevel->iLikeRepCntr>>1),
+                        pLevel->addrLikeRep);
+      VdbeCoverage(v);
+    }
+#endif
     if( pLevel->iLeftJoin ){
-      int addr;
-      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin);
-      assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
-           || (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 );
-      if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
+      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
+      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
+      if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
         sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
       }
-      if( pLevel->iIdxCur>=0 ){
+      if( pLoop->wsFlags & WHERE_INDEXED ){
         sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
       }
       if( pLevel->op==OP_Return ){
         sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
       }else{
-        sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrFirst);
+        sqlite3VdbeGoto(v, pLevel->addrFirst);
       }
       sqlite3VdbeJumpHere(v, addr);
     }
+    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
+                     pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));
   }
 
   /* The "break" point is here, just past the end of the outer loop.
@@ -105855,32 +131426,51 @@ SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
   */
   sqlite3VdbeResolveLabel(v, pWInfo->iBreak);
 
-  /* Close all of the cursors that were opened by sqlite3WhereBegin.
-  */
-  assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc );
+  assert( pWInfo->nLevel<=pTabList->nSrc );
   for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
+    int k, last;
+    VdbeOp *pOp;
+    Index *pIdx = 0;
     struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
     Table *pTab = pTabItem->pTab;
     assert( pTab!=0 );
+    pLoop = pLevel->pWLoop;
+
+    /* For a co-routine, change all OP_Column references to the table of
+    ** the co-routine into OP_Copy of result contained in a register.
+    ** OP_Rowid becomes OP_Null.
+    */
+    if( pTabItem->fg.viaCoroutine && !db->mallocFailed ){
+      translateColumnToCopy(v, pLevel->addrBody, pLevel->iTabCur,
+                            pTabItem->regResult, 0);
+      continue;
+    }
+
+    /* Close all of the cursors that were opened by sqlite3WhereBegin.
+    ** Except, do not close cursors that will be reused by the OR optimization
+    ** (WHERE_OR_SUBCLAUSE).  And do not close the OP_OpenWrite cursors
+    ** created for the ONEPASS optimization.
+    */
     if( (pTab->tabFlags & TF_Ephemeral)==0
      && pTab->pSelect==0
-     && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
+     && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
     ){
-      int ws = pLevel->plan.wsFlags;
-      if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
+      int ws = pLoop->wsFlags;
+      if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
         sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
       }
-      if( (ws & WHERE_INDEXED)!=0 && (ws & WHERE_TEMP_INDEX)==0 ){
+      if( (ws & WHERE_INDEXED)!=0
+       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
+       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
+      ){
         sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
       }
     }
 
-    /* If this scan uses an index, make code substitutions to read data
-    ** from the index in preference to the table. Sometimes, this means
-    ** the table need never be read from. This is a performance boost,
-    ** as the vdbe level waits until the table is read before actually
-    ** seeking the table cursor to the record corresponding to the current
-    ** position in the index.
+    /* If this scan uses an index, make VDBE code substitutions to read data
+    ** from the index instead of from the table where possible.  In some cases
+    ** this optimization prevents the table from ever being read, which can
+    ** yield a significant performance boost.
     ** 
     ** Calls to the code generator in between sqlite3WhereBegin and
     ** sqlite3WhereEnd will have created code that references the table
@@ -105888,26 +131478,34 @@ SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
     ** that reference the table and converts them into opcodes that
     ** reference the index.
     */
-    if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 && !db->mallocFailed){
-      int k, j, last;
-      VdbeOp *pOp;
-      Index *pIdx = pLevel->plan.u.pIdx;
-
-      assert( pIdx!=0 );
-      pOp = sqlite3VdbeGetOp(v, pWInfo->iTop);
+    if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
+      pIdx = pLoop->u.btree.pIndex;
+    }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
+      pIdx = pLevel->u.pCovidx;
+    }
+    if( pIdx
+     && (pWInfo->eOnePass==ONEPASS_OFF || !HasRowid(pIdx->pTable))
+     && !db->mallocFailed
+    ){
       last = sqlite3VdbeCurrentAddr(v);
-      for(k=pWInfo->iTop; k<last; k++, pOp++){
+      k = pLevel->addrBody;
+      pOp = sqlite3VdbeGetOp(v, k);
+      for(; k<last; k++, pOp++){
         if( pOp->p1!=pLevel->iTabCur ) continue;
         if( pOp->opcode==OP_Column ){
-          for(j=0; j<pIdx->nColumn; j++){
-            if( pOp->p2==pIdx->aiColumn[j] ){
-              pOp->p2 = j;
-              pOp->p1 = pLevel->iIdxCur;
-              break;
-            }
+          int x = pOp->p2;
+          assert( pIdx->pTable==pTab );
+          if( !HasRowid(pTab) ){
+            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+            x = pPk->aiColumn[x];
+            assert( x>=0 );
           }
-          assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
-               || j<pIdx->nColumn );
+          x = sqlite3ColumnOfIndex(pIdx, x);
+          if( x>=0 ){
+            pOp->p2 = x;
+            pOp->p1 = pLevel->iIdxCur;
+          }
+          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 );
         }else if( pOp->opcode==OP_Rowid ){
           pOp->p1 = pLevel->iIdxCur;
           pOp->opcode = OP_IdxRowid;
@@ -105925,19 +131523,34 @@ SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
 
 /************** End of where.c ***********************************************/
 /************** Begin file parse.c *******************************************/
-/* Driver template for the LEMON parser generator.
-** The author disclaims copyright to this source code.
+/*
+** 2000-05-29
 **
-** This version of "lempar.c" is modified, slightly, for use by SQLite.
-** The only modifications are the addition of a couple of NEVER()
-** macros to disable tests that are needed in the case of a general
-** LALR(1) grammar but which are always false in the
-** specific grammar used by SQLite.
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Driver template for the LEMON parser generator.
+**
+** The "lemon" program processes an LALR(1) input grammar file, then uses
+** this template to construct a parser.  The "lemon" program inserts text
+** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the
+** interstitial "-" characters) contained in this template is changed into
+** the value of the %name directive from the grammar.  Otherwise, the content
+** of this template is copied straight through into the generate parser
+** source file.
+**
+** The following is the concatenation of all %include directives from the
+** input grammar file:
 */
-/* First off, code is included that follows the "include" declaration
-** in the input grammar file. */
 /* #include <stdio.h> */
+/************ Begin %include sections from the grammar ************************/
 
+/* #include "sqliteInt.h" */
 
 /*
 ** Disable all error recovery processing in the parser push-down
@@ -105951,6 +131564,18 @@ SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
 #define yytestcase(X) testcase(X)
 
 /*
+** Indicate that sqlite3ParserFree() will never be called with a null
+** pointer.
+*/
+#define YYPARSEFREENEVERNULL 1
+
+/*
+** Alternative datatype for the argument to the malloc() routine passed
+** into sqlite3ParserAlloc().  The default is size_t.
+*/
+#define YYMALLOCARGTYPE  u64
+
+/*
 ** An instance of this structure holds information about the
 ** LIMIT clause of a SELECT statement.
 */
@@ -105965,7 +131590,7 @@ struct LimitVal {
 */
 struct LikeOp {
   Token eOperator;  /* "like" or "glob" or "regexp" */
-  int not;         /* True if the NOT keyword is present */
+  int bNot;         /* True if the NOT keyword is present */
 };
 
 /*
@@ -105984,6 +131609,37 @@ struct TrigEvent { int a; IdList * b; };
 */
 struct AttachKey { int type;  Token key; };
 
+/*
+** Disable lookaside memory allocation for objects that might be
+** shared across database connections.
+*/
+static void disableLookaside(Parse *pParse){
+  pParse->disableLookaside++;
+  pParse->db->lookaside.bDisable++;
+}
+
+
+  /*
+  ** For a compound SELECT statement, make sure p->pPrior->pNext==p for
+  ** all elements in the list.  And make sure list length does not exceed
+  ** SQLITE_LIMIT_COMPOUND_SELECT.
+  */
+  static void parserDoubleLinkSelect(Parse *pParse, Select *p){
+    if( p->pPrior ){
+      Select *pNext = 0, *pLoop;
+      int mxSelect, cnt = 0;
+      for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){
+        pLoop->pNext = pNext;
+        pLoop->selFlags |= SF_Compound;
+      }
+      if( (p->selFlags & SF_MultiValue)==0 && 
+        (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0 &&
+        cnt>mxSelect
+      ){
+        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
+      }
+    }
+  }
 
   /* This is a utility routine used to set the ExprSpan.zStart and
   ** ExprSpan.zEnd values of pOut so that the span covers the complete
@@ -105998,46 +131654,51 @@ struct AttachKey { int type;  Token key; };
   ** new Expr to populate pOut.  Set the span of pOut to be the identifier
   ** that created the expression.
   */
-  static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token *pValue){
-    pOut->pExpr = sqlite3PExpr(pParse, op, 0, 0, pValue);
-    pOut->zStart = pValue->z;
-    pOut->zEnd = &pValue->z[pValue->n];
+  static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token t){
+    pOut->pExpr = sqlite3PExpr(pParse, op, 0, 0, &t);
+    pOut->zStart = t.z;
+    pOut->zEnd = &t.z[t.n];
   }
 
   /* This routine constructs a binary expression node out of two ExprSpan
   ** objects and uses the result to populate a new ExprSpan object.
   */
   static void spanBinaryExpr(
-    ExprSpan *pOut,     /* Write the result here */
     Parse *pParse,      /* The parsing context.  Errors accumulate here */
     int op,             /* The binary operation */
-    ExprSpan *pLeft,    /* The left operand */
+    ExprSpan *pLeft,    /* The left operand, and output */
     ExprSpan *pRight    /* The right operand */
   ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pLeft->pExpr, pRight->pExpr, 0);
-    pOut->zStart = pLeft->zStart;
-    pOut->zEnd = pRight->zEnd;
+    pLeft->pExpr = sqlite3PExpr(pParse, op, pLeft->pExpr, pRight->pExpr, 0);
+    pLeft->zEnd = pRight->zEnd;
+  }
+
+  /* If doNot is true, then add a TK_NOT Expr-node wrapper around the
+  ** outside of *ppExpr.
+  */
+  static void exprNot(Parse *pParse, int doNot, ExprSpan *pSpan){
+    if( doNot ){
+      pSpan->pExpr = sqlite3PExpr(pParse, TK_NOT, pSpan->pExpr, 0, 0);
+    }
   }
 
   /* Construct an expression node for a unary postfix operator
   */
   static void spanUnaryPostfix(
-    ExprSpan *pOut,        /* Write the new expression node here */
     Parse *pParse,         /* Parsing context to record errors */
     int op,                /* The operator */
-    ExprSpan *pOperand,    /* The operand */
+    ExprSpan *pOperand,    /* The operand, and output */
     Token *pPostOp         /* The operand token for setting the span */
   ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
-    pOut->zStart = pOperand->zStart;
-    pOut->zEnd = &pPostOp->z[pPostOp->n];
+    pOperand->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
+    pOperand->zEnd = &pPostOp->z[pPostOp->n];
   }                           
 
   /* A routine to convert a binary TK_IS or TK_ISNOT expression into a
   ** unary TK_ISNULL or TK_NOTNULL expression. */
   static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){
     sqlite3 *db = pParse->db;
-    if( db->mallocFailed==0 && pY->op==TK_NULL ){
+    if( pA && pY && pY->op==TK_NULL ){
       pA->op = (u8)op;
       sqlite3ExprDelete(db, pA->pRight);
       pA->pRight = 0;
@@ -106053,80 +131714,112 @@ struct AttachKey { int type;  Token key; };
     ExprSpan *pOperand,    /* The operand */
     Token *pPreOp         /* The operand token for setting the span */
   ){
-    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
     pOut->zStart = pPreOp->z;
+    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
     pOut->zEnd = pOperand->zEnd;
   }
-/* Next is all token values, in a form suitable for use by makeheaders.
-** This section will be null unless lemon is run with the -m switch.
-*/
-/* 
-** These constants (all generated automatically by the parser generator)
-** specify the various kinds of tokens (terminals) that the parser
-** understands. 
-**
-** Each symbol here is a terminal symbol in the grammar.
-*/
-/* Make sure the INTERFACE macro is defined.
-*/
-#ifndef INTERFACE
-# define INTERFACE 1
-#endif
-/* The next thing included is series of defines which control
+
+  /* Add a single new term to an ExprList that is used to store a
+  ** list of identifiers.  Report an error if the ID list contains
+  ** a COLLATE clause or an ASC or DESC keyword, except ignore the
+  ** error while parsing a legacy schema.
+  */
+  static ExprList *parserAddExprIdListTerm(
+    Parse *pParse,
+    ExprList *pPrior,
+    Token *pIdToken,
+    int hasCollate,
+    int sortOrder
+  ){
+    ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);
+    if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)
+        && pParse->db->init.busy==0
+    ){
+      sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",
+                         pIdToken->n, pIdToken->z);
+    }
+    sqlite3ExprListSetName(pParse, p, pIdToken, 1);
+    return p;
+  }
+/**************** End of %include directives **********************************/
+/* These constants specify the various numeric values for terminal symbols
+** in a format understandable to "makeheaders".  This section is blank unless
+** "lemon" is run with the "-m" command-line option.
+***************** Begin makeheaders token definitions *************************/
+/**************** End makeheaders token definitions ***************************/
+
+/* The next sections is a series of control #defines.
 ** various aspects of the generated parser.
-**    YYCODETYPE         is the data type used for storing terminal
-**                       and nonterminal numbers.  "unsigned char" is
-**                       used if there are fewer than 250 terminals
-**                       and nonterminals.  "int" is used otherwise.
-**    YYNOCODE           is a number of type YYCODETYPE which corresponds
-**                       to no legal terminal or nonterminal number.  This
-**                       number is used to fill in empty slots of the hash 
-**                       table.
+**    YYCODETYPE         is the data type used to store the integer codes
+**                       that represent terminal and non-terminal symbols.
+**                       "unsigned char" is used if there are fewer than
+**                       256 symbols.  Larger types otherwise.
+**    YYNOCODE           is a number of type YYCODETYPE that is not used for
+**                       any terminal or nonterminal symbol.
 **    YYFALLBACK         If defined, this indicates that one or more tokens
-**                       have fall-back values which should be used if the
-**                       original value of the token will not parse.
-**    YYACTIONTYPE       is the data type used for storing terminal
-**                       and nonterminal numbers.  "unsigned char" is
-**                       used if there are fewer than 250 rules and
-**                       states combined.  "int" is used otherwise.
-**    sqlite3ParserTOKENTYPE     is the data type used for minor tokens given 
-**                       directly to the parser from the tokenizer.
-**    YYMINORTYPE        is the data type used for all minor tokens.
+**                       (also known as: "terminal symbols") have fall-back
+**                       values which should be used if the original symbol
+**                       would not parse.  This permits keywords to sometimes
+**                       be used as identifiers, for example.
+**    YYACTIONTYPE       is the data type used for "action codes" - numbers
+**                       that indicate what to do in response to the next
+**                       token.
+**    sqlite3ParserTOKENTYPE     is the data type used for minor type for terminal
+**                       symbols.  Background: A "minor type" is a semantic
+**                       value associated with a terminal or non-terminal
+**                       symbols.  For example, for an "ID" terminal symbol,
+**                       the minor type might be the name of the identifier.
+**                       Each non-terminal can have a different minor type.
+**                       Terminal symbols all have the same minor type, though.
+**                       This macros defines the minor type for terminal 
+**                       symbols.
+**    YYMINORTYPE        is the data type used for all minor types.
 **                       This is typically a union of many types, one of
 **                       which is sqlite3ParserTOKENTYPE.  The entry in the union
-**                       for base tokens is called "yy0".
+**                       for terminal symbols is called "yy0".
 **    YYSTACKDEPTH       is the maximum depth of the parser's stack.  If
 **                       zero the stack is dynamically sized using realloc()
 **    sqlite3ParserARG_SDECL     A static variable declaration for the %extra_argument
 **    sqlite3ParserARG_PDECL     A parameter declaration for the %extra_argument
 **    sqlite3ParserARG_STORE     Code to store %extra_argument into yypParser
 **    sqlite3ParserARG_FETCH     Code to extract %extra_argument from yypParser
-**    YYNSTATE           the combined number of states.
-**    YYNRULE            the number of rules in the grammar
 **    YYERRORSYMBOL      is the code number of the error symbol.  If not
 **                       defined, then do no error processing.
+**    YYNSTATE           the combined number of states.
+**    YYNRULE            the number of rules in the grammar
+**    YY_MAX_SHIFT       Maximum value for shift actions
+**    YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
+**    YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
+**    YY_MIN_REDUCE      Maximum value for reduce actions
+**    YY_ERROR_ACTION    The yy_action[] code for syntax error
+**    YY_ACCEPT_ACTION   The yy_action[] code for accept
+**    YY_NO_ACTION       The yy_action[] code for no-op
 */
+#ifndef INTERFACE
+# define INTERFACE 1
+#endif
+/************* Begin control #defines *****************************************/
 #define YYCODETYPE unsigned char
-#define YYNOCODE 253
+#define YYNOCODE 252
 #define YYACTIONTYPE unsigned short int
-#define YYWILDCARD 67
+#define YYWILDCARD 96
 #define sqlite3ParserTOKENTYPE Token
 typedef union {
   int yyinit;
   sqlite3ParserTOKENTYPE yy0;
-  int yy4;
-  struct TrigEvent yy90;
-  ExprSpan yy118;
-  TriggerStep* yy203;
-  u8 yy210;
-  struct {int value; int mask;} yy215;
-  SrcList* yy259;
-  struct LimitVal yy292;
-  Expr* yy314;
-  ExprList* yy322;
-  struct LikeOp yy342;
-  IdList* yy384;
-  Select* yy387;
+  Expr* yy72;
+  TriggerStep* yy145;
+  ExprList* yy148;
+  SrcList* yy185;
+  ExprSpan yy190;
+  int yy194;
+  Select* yy243;
+  IdList* yy254;
+  With* yy285;
+  struct TrigEvent yy332;
+  struct LimitVal yy354;
+  struct LikeOp yy392;
+  struct {int value; int mask;} yy497;
 } YYMINORTYPE;
 #ifndef YYSTACKDEPTH
 #define YYSTACKDEPTH 100
@@ -106135,16 +131828,18 @@ typedef union {
 #define sqlite3ParserARG_PDECL ,Parse *pParse
 #define sqlite3ParserARG_FETCH Parse *pParse = yypParser->pParse
 #define sqlite3ParserARG_STORE yypParser->pParse = pParse
-#define YYNSTATE 630
-#define YYNRULE 329
 #define YYFALLBACK 1
-#define YY_NO_ACTION      (YYNSTATE+YYNRULE+2)
-#define YY_ACCEPT_ACTION  (YYNSTATE+YYNRULE+1)
-#define YY_ERROR_ACTION   (YYNSTATE+YYNRULE)
-
-/* The yyzerominor constant is used to initialize instances of
-** YYMINORTYPE objects to zero. */
-static const YYMINORTYPE yyzerominor = { 0 };
+#define YYNSTATE             443
+#define YYNRULE              328
+#define YY_MAX_SHIFT         442
+#define YY_MIN_SHIFTREDUCE   653
+#define YY_MAX_SHIFTREDUCE   980
+#define YY_MIN_REDUCE        981
+#define YY_MAX_REDUCE        1308
+#define YY_ERROR_ACTION      1309
+#define YY_ACCEPT_ACTION     1310
+#define YY_NO_ACTION         1311
+/************* End control #defines *******************************************/
 
 /* Define the yytestcase() macro to be a no-op if is not already defined
 ** otherwise.
@@ -106167,16 +131862,20 @@ static const YYMINORTYPE yyzerominor = { 0 };
 ** Suppose the action integer is N.  Then the action is determined as
 ** follows
 **
-**   0 <= N < YYNSTATE                  Shift N.  That is, push the lookahead
+**   0 <= N <= YY_MAX_SHIFT             Shift N.  That is, push the lookahead
 **                                      token onto the stack and goto state N.
 **
-**   YYNSTATE <= N < YYNSTATE+YYNRULE   Reduce by rule N-YYNSTATE.
+**   N between YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then
+**     and YY_MAX_SHIFTREDUCE           reduce by rule N-YY_MIN_SHIFTREDUCE.
 **
-**   N == YYNSTATE+YYNRULE              A syntax error has occurred.
+**   N between YY_MIN_REDUCE            Reduce by rule N-YY_MIN_REDUCE
+**     and YY_MAX_REDUCE
+
+**   N == YY_ERROR_ACTION               A syntax error has occurred.
 **
-**   N == YYNSTATE+YYNRULE+1            The parser accepts its input.
+**   N == YY_ACCEPT_ACTION              The parser accepts its input.
 **
-**   N == YYNSTATE+YYNRULE+2            No such action.  Denotes unused
+**   N == YY_NO_ACTION                  No such action.  Denotes unused
 **                                      slots in the yy_action[] table.
 **
 ** The action table is constructed as a single large table named yy_action[].
@@ -106205,478 +131904,455 @@ static const YYMINORTYPE yyzerominor = { 0 };
 **  yy_reduce_ofst[]   For each state, the offset into yy_action for
 **                     shifting non-terminals after a reduce.
 **  yy_default[]       Default action for each state.
-*/
-#define YY_ACTTAB_COUNT (1557)
+**
+*********** Begin parsing tables **********************************************/
+#define YY_ACTTAB_COUNT (1507)
 static const YYACTIONTYPE yy_action[] = {
- /*     0 */   313,  960,  186,  419,    2,  172,  627,  597,   55,   55,
- /*    10 */    55,   55,   48,   53,   53,   53,   53,   52,   52,   51,
- /*    20 */    51,   51,   50,  238,  302,  283,  623,  622,  516,  515,
- /*    30 */   590,  584,   55,   55,   55,   55,  282,   53,   53,   53,
- /*    40 */    53,   52,   52,   51,   51,   51,   50,  238,    6,   56,
- /*    50 */    57,   47,  582,  581,  583,  583,   54,   54,   55,   55,
- /*    60 */    55,   55,  608,   53,   53,   53,   53,   52,   52,   51,
- /*    70 */    51,   51,   50,  238,  313,  597,  409,  330,  579,  579,
- /*    80 */    32,   53,   53,   53,   53,   52,   52,   51,   51,   51,
- /*    90 */    50,  238,  330,  217,  620,  619,  166,  411,  624,  382,
- /*   100 */   379,  378,    7,  491,  590,  584,  200,  199,  198,   58,
- /*   110 */   377,  300,  414,  621,  481,   66,  623,  622,  621,  580,
- /*   120 */   254,  601,   94,   56,   57,   47,  582,  581,  583,  583,
- /*   130 */    54,   54,   55,   55,   55,   55,  671,   53,   53,   53,
- /*   140 */    53,   52,   52,   51,   51,   51,   50,  238,  313,  532,
- /*   150 */   226,  506,  507,  133,  177,  139,  284,  385,  279,  384,
- /*   160 */   169,  197,  342,  398,  251,  226,  253,  275,  388,  167,
- /*   170 */   139,  284,  385,  279,  384,  169,  570,  236,  590,  584,
- /*   180 */   672,  240,  275,  157,  620,  619,  554,  437,   51,   51,
- /*   190 */    51,   50,  238,  343,  439,  553,  438,   56,   57,   47,
- /*   200 */   582,  581,  583,  583,   54,   54,   55,   55,   55,   55,
- /*   210 */   465,   53,   53,   53,   53,   52,   52,   51,   51,   51,
- /*   220 */    50,  238,  313,  390,   52,   52,   51,   51,   51,   50,
- /*   230 */   238,  391,  166,  491,  566,  382,  379,  378,  409,  440,
- /*   240 */   579,  579,  252,  440,  607,   66,  377,  513,  621,   49,
- /*   250 */    46,  147,  590,  584,  621,   16,  466,  189,  621,  441,
- /*   260 */   442,  673,  526,  441,  340,  577,  595,   64,  194,  482,
- /*   270 */   434,   56,   57,   47,  582,  581,  583,  583,   54,   54,
- /*   280 */    55,   55,   55,   55,   30,   53,   53,   53,   53,   52,
- /*   290 */    52,   51,   51,   51,   50,  238,  313,  593,  593,  593,
- /*   300 */   387,  578,  606,  493,  259,  351,  258,  411,    1,  623,
- /*   310 */   622,  496,  623,  622,   65,  240,  623,  622,  597,  443,
- /*   320 */   237,  239,  414,  341,  237,  602,  590,  584,   18,  603,
- /*   330 */   166,  601,   87,  382,  379,  378,   67,  623,  622,   38,
- /*   340 */   623,  622,  176,  270,  377,   56,   57,   47,  582,  581,
- /*   350 */   583,  583,   54,   54,   55,   55,   55,   55,  175,   53,
- /*   360 */    53,   53,   53,   52,   52,   51,   51,   51,   50,  238,
- /*   370 */   313,  396,  233,  411,  531,  565,  317,  620,  619,   44,
- /*   380 */   620,  619,  240,  206,  620,  619,  597,  266,  414,  268,
- /*   390 */   409,  597,  579,  579,  352,  184,  505,  601,   73,  533,
- /*   400 */   590,  584,  466,  548,  190,  620,  619,  576,  620,  619,
- /*   410 */   547,  383,  551,   35,  332,  575,  574,  600,  504,   56,
- /*   420 */    57,   47,  582,  581,  583,  583,   54,   54,   55,   55,
- /*   430 */    55,   55,  567,   53,   53,   53,   53,   52,   52,   51,
- /*   440 */    51,   51,   50,  238,  313,  411,  561,  561,  528,  364,
- /*   450 */   259,  351,  258,  183,  361,  549,  524,  374,  411,  597,
- /*   460 */   414,  240,  560,  560,  409,  604,  579,  579,  328,  601,
- /*   470 */    93,  623,  622,  414,  590,  584,  237,  564,  559,  559,
- /*   480 */   520,  402,  601,   87,  409,  210,  579,  579,  168,  421,
- /*   490 */   950,  519,  950,   56,   57,   47,  582,  581,  583,  583,
- /*   500 */    54,   54,   55,   55,   55,   55,  192,   53,   53,   53,
- /*   510 */    53,   52,   52,   51,   51,   51,   50,  238,  313,  600,
- /*   520 */   293,  563,  511,  234,  357,  146,  475,  475,  367,  411,
- /*   530 */   562,  411,  358,  542,  425,  171,  411,  215,  144,  620,
- /*   540 */   619,  544,  318,  353,  414,  203,  414,  275,  590,  584,
- /*   550 */   549,  414,  174,  601,   94,  601,   79,  558,  471,   61,
- /*   560 */   601,   79,  421,  949,  350,  949,   34,   56,   57,   47,
- /*   570 */   582,  581,  583,  583,   54,   54,   55,   55,   55,   55,
- /*   580 */   535,   53,   53,   53,   53,   52,   52,   51,   51,   51,
- /*   590 */    50,  238,  313,  307,  424,  394,  272,   49,   46,  147,
- /*   600 */   349,  322,    4,  411,  491,  312,  321,  425,  568,  492,
- /*   610 */   216,  264,  407,  575,  574,  429,   66,  549,  414,  621,
- /*   620 */   540,  602,  590,  584,   13,  603,  621,  601,   72,   12,
- /*   630 */   618,  617,  616,  202,  210,  621,  546,  469,  422,  319,
- /*   640 */   148,   56,   57,   47,  582,  581,  583,  583,   54,   54,
- /*   650 */    55,   55,   55,   55,  338,   53,   53,   53,   53,   52,
- /*   660 */    52,   51,   51,   51,   50,  238,  313,  600,  600,  411,
- /*   670 */    39,   21,   37,  170,  237,  875,  411,  572,  572,  201,
- /*   680 */   144,  473,  538,  331,  414,  474,  143,  146,  630,  628,
- /*   690 */   334,  414,  353,  601,   68,  168,  590,  584,  132,  365,
- /*   700 */   601,   96,  307,  423,  530,  336,   49,   46,  147,  568,
- /*   710 */   406,  216,  549,  360,  529,   56,   57,   47,  582,  581,
- /*   720 */   583,  583,   54,   54,   55,   55,   55,   55,  411,   53,
- /*   730 */    53,   53,   53,   52,   52,   51,   51,   51,   50,  238,
- /*   740 */   313,  411,  605,  414,  484,  510,  172,  422,  597,  318,
- /*   750 */   496,  485,  601,   99,  411,  142,  414,  411,  231,  411,
- /*   760 */   540,  411,  359,  629,    2,  601,   97,  426,  308,  414,
- /*   770 */   590,  584,  414,   20,  414,  621,  414,  621,  601,  106,
- /*   780 */   503,  601,  105,  601,  108,  601,  109,  204,   28,   56,
- /*   790 */    57,   47,  582,  581,  583,  583,   54,   54,   55,   55,
- /*   800 */    55,   55,  411,   53,   53,   53,   53,   52,   52,   51,
- /*   810 */    51,   51,   50,  238,  313,  411,  597,  414,  411,  276,
- /*   820 */   214,  600,  411,  366,  213,  381,  601,  134,  274,  500,
- /*   830 */   414,  167,  130,  414,  621,  411,  354,  414,  376,  601,
- /*   840 */   135,  129,  601,  100,  590,  584,  601,  104,  522,  521,
- /*   850 */   414,  621,  224,  273,  600,  167,  327,  282,  600,  601,
- /*   860 */   103,  468,  521,   56,   57,   47,  582,  581,  583,  583,
- /*   870 */    54,   54,   55,   55,   55,   55,  411,   53,   53,   53,
- /*   880 */    53,   52,   52,   51,   51,   51,   50,  238,  313,  411,
- /*   890 */    27,  414,  411,  375,  276,  167,  359,  544,   50,  238,
- /*   900 */   601,   95,  128,  223,  414,  411,  165,  414,  411,  621,
- /*   910 */   411,  621,  612,  601,  102,  372,  601,   76,  590,  584,
- /*   920 */   414,  570,  236,  414,  470,  414,  167,  621,  188,  601,
- /*   930 */    98,  225,  601,  138,  601,  137,  232,   56,   45,   47,
- /*   940 */   582,  581,  583,  583,   54,   54,   55,   55,   55,   55,
- /*   950 */   411,   53,   53,   53,   53,   52,   52,   51,   51,   51,
- /*   960 */    50,  238,  313,  276,  276,  414,  411,  276,  544,  459,
- /*   970 */   359,  171,  209,  479,  601,  136,  628,  334,  621,  621,
- /*   980 */   125,  414,  621,  368,  411,  621,  257,  540,  589,  588,
- /*   990 */   601,   75,  590,  584,  458,  446,   23,   23,  124,  414,
- /*  1000 */   326,  325,  621,  427,  324,  309,  600,  288,  601,   92,
- /*  1010 */   586,  585,   57,   47,  582,  581,  583,  583,   54,   54,
- /*  1020 */    55,   55,   55,   55,  411,   53,   53,   53,   53,   52,
- /*  1030 */    52,   51,   51,   51,   50,  238,  313,  587,  411,  414,
- /*  1040 */   411,  207,  611,  476,  171,  472,  160,  123,  601,   91,
- /*  1050 */   323,  261,   15,  414,  464,  414,  411,  621,  411,  354,
- /*  1060 */   222,  411,  601,   74,  601,   90,  590,  584,  159,  264,
- /*  1070 */   158,  414,  461,  414,  621,  600,  414,  121,  120,   25,
- /*  1080 */   601,   89,  601,  101,  621,  601,   88,   47,  582,  581,
- /*  1090 */   583,  583,   54,   54,   55,   55,   55,   55,  544,   53,
- /*  1100 */    53,   53,   53,   52,   52,   51,   51,   51,   50,  238,
- /*  1110 */    43,  405,  263,    3,  610,  264,  140,  415,  622,   24,
- /*  1120 */   410,   11,  456,  594,  118,  155,  219,  452,  408,  621,
- /*  1130 */   621,  621,  156,   43,  405,  621,    3,  286,  621,  113,
- /*  1140 */   415,  622,  111,  445,  411,  400,  557,  403,  545,   10,
- /*  1150 */   411,  408,  264,  110,  205,  436,  541,  566,  453,  414,
- /*  1160 */   621,  621,   63,  621,  435,  414,  411,  621,  601,   94,
- /*  1170 */   403,  621,  411,  337,  601,   86,  150,   40,   41,  534,
- /*  1180 */   566,  414,  242,  264,   42,  413,  412,  414,  600,  595,
- /*  1190 */   601,   85,  191,  333,  107,  451,  601,   84,  621,  539,
- /*  1200 */    40,   41,  420,  230,  411,  149,  316,   42,  413,  412,
- /*  1210 */   398,  127,  595,  315,  621,  399,  278,  625,  181,  414,
- /*  1220 */   593,  593,  593,  592,  591,   14,  450,  411,  601,   71,
- /*  1230 */   240,  621,   43,  405,  264,    3,  615,  180,  264,  415,
- /*  1240 */   622,  614,  414,  593,  593,  593,  592,  591,   14,  621,
- /*  1250 */   408,  601,   70,  621,  417,   33,  405,  613,    3,  411,
- /*  1260 */   264,  411,  415,  622,  418,  626,  178,  509,    8,  403,
- /*  1270 */   241,  416,  126,  408,  414,  621,  414,  449,  208,  566,
- /*  1280 */   240,  221,  621,  601,   83,  601,   82,  599,  297,  277,
- /*  1290 */   296,   30,  403,   31,  395,  264,  295,  397,  489,   40,
- /*  1300 */    41,  411,  566,  220,  621,  294,   42,  413,  412,  271,
- /*  1310 */   621,  595,  600,  621,   59,   60,  414,  269,  267,  623,
- /*  1320 */   622,   36,   40,   41,  621,  601,   81,  598,  235,   42,
- /*  1330 */   413,  412,  621,  621,  595,  265,  344,  411,  248,  556,
- /*  1340 */   173,  185,  593,  593,  593,  592,  591,   14,  218,   29,
- /*  1350 */   621,  543,  414,  305,  304,  303,  179,  301,  411,  566,
- /*  1360 */   454,  601,   80,  289,  335,  593,  593,  593,  592,  591,
- /*  1370 */    14,  411,  287,  414,  151,  392,  246,  260,  411,  196,
- /*  1380 */   195,  523,  601,   69,  411,  245,  414,  526,  537,  285,
- /*  1390 */   389,  595,  621,  414,  536,  601,   17,  362,  153,  414,
- /*  1400 */   466,  463,  601,   78,  154,  414,  462,  152,  601,   77,
- /*  1410 */   355,  255,  621,  455,  601,    9,  621,  386,  444,  517,
- /*  1420 */   247,  621,  593,  593,  593,  621,  621,  244,  621,  243,
- /*  1430 */   430,  518,  292,  621,  329,  621,  145,  393,  280,  513,
- /*  1440 */   291,  131,  621,  514,  621,  621,  311,  621,  259,  346,
- /*  1450 */   249,  621,  621,  229,  314,  621,  228,  512,  227,  240,
- /*  1460 */   494,  488,  310,  164,  487,  486,  373,  480,  163,  262,
- /*  1470 */   369,  371,  162,   26,  212,  478,  477,  161,  141,  363,
- /*  1480 */   467,  122,  339,  187,  119,  348,  347,  117,  116,  115,
- /*  1490 */   114,  112,  182,  457,  320,   22,  433,  432,  448,   19,
- /*  1500 */   609,  431,  428,   62,  193,  596,  573,  298,  555,  552,
- /*  1510 */   571,  404,  290,  380,  498,  510,  495,  306,  281,  499,
- /*  1520 */   250,    5,  497,  460,  345,  447,  569,  550,  238,  299,
- /*  1530 */   527,  525,  508,  961,  502,  501,  961,  401,  961,  211,
- /*  1540 */   490,  356,  256,  961,  483,  961,  961,  961,  961,  961,
- /*  1550 */   961,  961,  961,  961,  961,  961,  370,
+ /*     0 */   317,  814,  341,  808,    5,  195,  195,  802,   93,   94,
+ /*    10 */    84,  823,  823,  835,  838,  827,  827,   91,   91,   92,
+ /*    20 */    92,   92,   92,  293,   90,   90,   90,   90,   89,   89,
+ /*    30 */    88,   88,   88,   87,  341,  317,  958,  958,  807,  807,
+ /*    40 */   807,  928,  344,   93,   94,   84,  823,  823,  835,  838,
+ /*    50 */   827,  827,   91,   91,   92,   92,   92,   92,  328,   90,
+ /*    60 */    90,   90,   90,   89,   89,   88,   88,   88,   87,  341,
+ /*    70 */    89,   89,   88,   88,   88,   87,  341,  776,  958,  958,
+ /*    80 */   317,   88,   88,   88,   87,  341,  777,   69,   93,   94,
+ /*    90 */    84,  823,  823,  835,  838,  827,  827,   91,   91,   92,
+ /*   100 */    92,   92,   92,  437,   90,   90,   90,   90,   89,   89,
+ /*   110 */    88,   88,   88,   87,  341, 1310,  147,  147,    2,  317,
+ /*   120 */    76,   25,   74,   49,   49,   87,  341,   93,   94,   84,
+ /*   130 */   823,  823,  835,  838,  827,  827,   91,   91,   92,   92,
+ /*   140 */    92,   92,   95,   90,   90,   90,   90,   89,   89,   88,
+ /*   150 */    88,   88,   87,  341,  939,  939,  317,  260,  415,  400,
+ /*   160 */   398,   58,  737,  737,   93,   94,   84,  823,  823,  835,
+ /*   170 */   838,  827,  827,   91,   91,   92,   92,   92,   92,   57,
+ /*   180 */    90,   90,   90,   90,   89,   89,   88,   88,   88,   87,
+ /*   190 */   341,  317, 1253,  928,  344,  269,  940,  941,  242,   93,
+ /*   200 */    94,   84,  823,  823,  835,  838,  827,  827,   91,   91,
+ /*   210 */    92,   92,   92,   92,  293,   90,   90,   90,   90,   89,
+ /*   220 */    89,   88,   88,   88,   87,  341,  317,  919, 1303,  793,
+ /*   230 */   691, 1303,  724,  724,   93,   94,   84,  823,  823,  835,
+ /*   240 */   838,  827,  827,   91,   91,   92,   92,   92,   92,  337,
+ /*   250 */    90,   90,   90,   90,   89,   89,   88,   88,   88,   87,
+ /*   260 */   341,  317,  114,  919, 1304,  684,  395, 1304,  124,   93,
+ /*   270 */    94,   84,  823,  823,  835,  838,  827,  827,   91,   91,
+ /*   280 */    92,   92,   92,   92,  683,   90,   90,   90,   90,   89,
+ /*   290 */    89,   88,   88,   88,   87,  341,  317,   86,   83,  169,
+ /*   300 */   801,  917,  234,  399,   93,   94,   84,  823,  823,  835,
+ /*   310 */   838,  827,  827,   91,   91,   92,   92,   92,   92,  686,
+ /*   320 */    90,   90,   90,   90,   89,   89,   88,   88,   88,   87,
+ /*   330 */   341,  317,  436,  742,   86,   83,  169,  917,  741,   93,
+ /*   340 */    94,   84,  823,  823,  835,  838,  827,  827,   91,   91,
+ /*   350 */    92,   92,   92,   92,  902,   90,   90,   90,   90,   89,
+ /*   360 */    89,   88,   88,   88,   87,  341,  317,  321,  434,  434,
+ /*   370 */   434,    1,  722,  722,   93,   94,   84,  823,  823,  835,
+ /*   380 */   838,  827,  827,   91,   91,   92,   92,   92,   92,  190,
+ /*   390 */    90,   90,   90,   90,   89,   89,   88,   88,   88,   87,
+ /*   400 */   341,  317,  685,  292,  939,  939,  150,  977,  310,   93,
+ /*   410 */    94,   84,  823,  823,  835,  838,  827,  827,   91,   91,
+ /*   420 */    92,   92,   92,   92,  437,   90,   90,   90,   90,   89,
+ /*   430 */    89,   88,   88,   88,   87,  341,  926,    2,  372,  719,
+ /*   440 */   698,  369,  950,  317,   49,   49,  940,  941,  719,  177,
+ /*   450 */    72,   93,   94,   84,  823,  823,  835,  838,  827,  827,
+ /*   460 */    91,   91,   92,   92,   92,   92,  322,   90,   90,   90,
+ /*   470 */    90,   89,   89,   88,   88,   88,   87,  341,  317,  415,
+ /*   480 */   405,  824,  824,  836,  839,   75,   93,   82,   84,  823,
+ /*   490 */   823,  835,  838,  827,  827,   91,   91,   92,   92,   92,
+ /*   500 */    92,  430,   90,   90,   90,   90,   89,   89,   88,   88,
+ /*   510 */    88,   87,  341,  317,  340,  340,  340,  658,  659,  660,
+ /*   520 */   333,  288,   94,   84,  823,  823,  835,  838,  827,  827,
+ /*   530 */    91,   91,   92,   92,   92,   92,  437,   90,   90,   90,
+ /*   540 */    90,   89,   89,   88,   88,   88,   87,  341,  317,  882,
+ /*   550 */   882,  375,  828,   66,  330,  409,   49,   49,   84,  823,
+ /*   560 */   823,  835,  838,  827,  827,   91,   91,   92,   92,   92,
+ /*   570 */    92,  351,   90,   90,   90,   90,   89,   89,   88,   88,
+ /*   580 */    88,   87,  341,   80,  432,  742,    3, 1180,  351,  350,
+ /*   590 */   741,  334,  796,  939,  939,  761,   80,  432,  278,    3,
+ /*   600 */   204,  161,  279,  393,  274,  392,  191,  362,  437,  277,
+ /*   610 */   745,   77,   78,  272,  800,  254,  355,  243,   79,  342,
+ /*   620 */   342,   86,   83,  169,   77,   78,  234,  399,   49,   49,
+ /*   630 */   435,   79,  342,  342,  437,  940,  941,  186,  442,  655,
+ /*   640 */   390,  387,  386,  435,  235,  213,  108,  421,  761,  351,
+ /*   650 */   437,  385,  167,  732,   10,   10,  124,  124,  671,  814,
+ /*   660 */   421,  439,  438,  415,  414,  802,  362,  168,  327,  124,
+ /*   670 */    49,   49,  814,  219,  439,  438,  800,  186,  802,  326,
+ /*   680 */   390,  387,  386,  437, 1248, 1248,   23,  939,  939,   80,
+ /*   690 */   432,  385,    3,  761,  416,  876,  807,  807,  807,  809,
+ /*   700 */    19,  290,  149,   49,   49,  415,  396,  260,  910,  807,
+ /*   710 */   807,  807,  809,   19,  312,  237,  145,   77,   78,  746,
+ /*   720 */   168,  702,  437,  149,   79,  342,  342,  114,  358,  940,
+ /*   730 */   941,  302,  223,  397,  345,  313,  435,  260,  415,  417,
+ /*   740 */   858,  374,   31,   31,   80,  432,  761,    3,  348,   92,
+ /*   750 */    92,   92,   92,  421,   90,   90,   90,   90,   89,   89,
+ /*   760 */    88,   88,   88,   87,  341,  814,  114,  439,  438,  796,
+ /*   770 */   367,  802,   77,   78,  701,  796,  124, 1187,  220,   79,
+ /*   780 */   342,  342,  124,  747,  734,  939,  939,  775,  404,  939,
+ /*   790 */   939,  435,  254,  360,  253,  402,  895,  346,  254,  360,
+ /*   800 */   253,  774,  807,  807,  807,  809,   19,  800,  421,   90,
+ /*   810 */    90,   90,   90,   89,   89,   88,   88,   88,   87,  341,
+ /*   820 */   814,  114,  439,  438,  939,  939,  802,  940,  941,  114,
+ /*   830 */   437,  940,  941,   86,   83,  169,  192,  166,  309,  979,
+ /*   840 */    70,  432,  700,    3,  382,  870,  238,   86,   83,  169,
+ /*   850 */    10,   10,  361,  406,  763,  190,  222,  807,  807,  807,
+ /*   860 */   809,   19,  870,  872,  329,   24,  940,  941,   77,   78,
+ /*   870 */   359,  437,  335,  260,  218,   79,  342,  342,  437,  307,
+ /*   880 */   306,  305,  207,  303,  339,  338,  668,  435,  339,  338,
+ /*   890 */   407,   10,   10,  762,  216,  216,  939,  939,   49,   49,
+ /*   900 */   437,  260,   97,  241,  421,  225,  402,  189,  188,  187,
+ /*   910 */   309,  918,  980,  149,  221,  898,  814,  868,  439,  438,
+ /*   920 */    10,   10,  802,  870,  915,  316,  898,  163,  162,  171,
+ /*   930 */   249,  240,  322,  410,  412,  687,  687,  272,  940,  941,
+ /*   940 */   239,  965,  901,  437,  226,  403,  226,  437,  963,  367,
+ /*   950 */   964,  173,  248,  807,  807,  807,  809,   19,  174,  367,
+ /*   960 */   899,  124,  172,   48,   48,    9,    9,   35,   35,  966,
+ /*   970 */   966,  899,  363,  966,  966,  814,  900,  808,  725,  939,
+ /*   980 */   939,  802,  895,  318,  980,  324,  125,  900,  726,  420,
+ /*   990 */    92,   92,   92,   92,   85,   90,   90,   90,   90,   89,
+ /*  1000 */    89,   88,   88,   88,   87,  341,  216,  216,  437,  946,
+ /*  1010 */   349,  292,  807,  807,  807,  114,  291,  693,  402,  705,
+ /*  1020 */   890,  940,  941,  437,  245,  889,  247,  437,   36,   36,
+ /*  1030 */   437,  353,  391,  437,  260,  252,  260,  437,  361,  437,
+ /*  1040 */   706,  437,  370,   12,   12,  224,  437,   27,   27,  437,
+ /*  1050 */    37,   37,  437,   38,   38,  752,  368,   39,   39,   28,
+ /*  1060 */    28,   29,   29,  215,  166,  331,   40,   40,  437,   41,
+ /*  1070 */    41,  437,   42,   42,  437,  866,  246,  731,  437,  879,
+ /*  1080 */   437,  256,  437,  878,  437,  267,  437,  261,   11,   11,
+ /*  1090 */   437,   43,   43,  437,   99,   99,  437,  373,   44,   44,
+ /*  1100 */    45,   45,   32,   32,   46,   46,   47,   47,  437,  426,
+ /*  1110 */    33,   33,  776,  116,  116,  437,  117,  117,  437,  124,
+ /*  1120 */   437,  777,  437,  260,  437,  957,  437,  352,  118,  118,
+ /*  1130 */   437,  195,  437,  111,  437,   53,   53,  264,   34,   34,
+ /*  1140 */   100,  100,   50,   50,  101,  101,  102,  102,  437,  260,
+ /*  1150 */    98,   98,  115,  115,  113,  113,  437,  262,  437,  265,
+ /*  1160 */   437,  943,  958,  437,  727,  437,  681,  437,  106,  106,
+ /*  1170 */    68,  437,  893,  730,  437,  365,  105,  105,  103,  103,
+ /*  1180 */   104,  104,  217,   52,   52,   54,   54,   51,   51,  694,
+ /*  1190 */   259,   26,   26,  266,   30,   30,  677,  323,  433,  323,
+ /*  1200 */   674,  423,  427,  943,  958,  114,  114,  431,  681,  865,
+ /*  1210 */  1277,  233,  366,  714,  112,   20,  154,  704,  703,  810,
+ /*  1220 */   914,   55,  159,  311,  798,  255,  383,  194,   68,  200,
+ /*  1230 */    21,  694,  268,  114,  114,  114,  270,  711,  712,   68,
+ /*  1240 */   114,  739,  770,  715,   71,  194,  861,  875,  875,  200,
+ /*  1250 */   696,  865,  874,  874,  679,  699,  273,  110,  229,  419,
+ /*  1260 */   768,  810,  799,  378,  748,  759,  418,  210,  294,  281,
+ /*  1270 */   295,  806,  283,  682,  676,  665,  664,  666,  933,  151,
+ /*  1280 */   285,    7, 1267,  308,  251,  790,  354,  244,  892,  364,
+ /*  1290 */   287,  422,  300,  164,  160,  936,  974,  127,  197,  137,
+ /*  1300 */   909,  907,  971,  388,  276,  863,  862,   56,  698,  325,
+ /*  1310 */   148,   59,  122,   66,  356,  381,  357,  176,  152,   62,
+ /*  1320 */   371,  130,  877,  181,  377,  760,  211,  182,  132,  133,
+ /*  1330 */   134,  135,  258,  146,  140,  795,  787,  263,  183,  379,
+ /*  1340 */   667,  394,  184,  332,  894,  314,  718,  717,  857,  716,
+ /*  1350 */   696,  315,  709,  690,   65,  196,    6,  408,  289,  708,
+ /*  1360 */   275,  689,  688,  948,  756,  757,  280,  282,  425,  755,
+ /*  1370 */   284,  336,   73,   67,  754,  429,  411,   96,  286,  413,
+ /*  1380 */   205,  934,  673,   22,  209,  440,  119,  120,  109,  206,
+ /*  1390 */   208,  441,  662,  661,  656,  843,  654,  343,  158,  236,
+ /*  1400 */   170,  347,  107,  227,  121,  738,  873,  298,  296,  297,
+ /*  1410 */   299,  871,  794,  128,  129,  728,  230,  131,  175,  250,
+ /*  1420 */   888,  136,  138,  231,  232,  139,   60,   61,  891,  178,
+ /*  1430 */   179,  887,    8,   13,  180,  257,  880,  968,  194,  141,
+ /*  1440 */   142,  376,  153,  670,  380,  185,  143,  277,   63,  384,
+ /*  1450 */    14,  707,  271,   15,  389,   64,  319,  320,  126,  228,
+ /*  1460 */   813,  812,  841,  736,  123,   16,  401,  740,    4,  769,
+ /*  1470 */   165,  212,  214,  193,  144,  764,   71,   68,   17,   18,
+ /*  1480 */   856,  842,  840,  897,  845,  896,  199,  198,  923,  155,
+ /*  1490 */   424,  929,  924,  156,  201,  202,  428,  844,  157,  203,
+ /*  1500 */   811,  680,   81, 1269, 1268,  301,  304,
 };
 static const YYCODETYPE yy_lookahead[] = {
- /*     0 */    19,  142,  143,  144,  145,   24,    1,   26,   77,   78,
- /*    10 */    79,   80,   81,   82,   83,   84,   85,   86,   87,   88,
- /*    20 */    89,   90,   91,   92,   15,   98,   26,   27,    7,    8,
- /*    30 */    49,   50,   77,   78,   79,   80,  109,   82,   83,   84,
- /*    40 */    85,   86,   87,   88,   89,   90,   91,   92,   22,   68,
- /*    50 */    69,   70,   71,   72,   73,   74,   75,   76,   77,   78,
- /*    60 */    79,   80,   23,   82,   83,   84,   85,   86,   87,   88,
- /*    70 */    89,   90,   91,   92,   19,   94,  112,   19,  114,  115,
- /*    80 */    25,   82,   83,   84,   85,   86,   87,   88,   89,   90,
- /*    90 */    91,   92,   19,   22,   94,   95,   96,  150,  150,   99,
- /*   100 */   100,  101,   76,  150,   49,   50,  105,  106,  107,   54,
- /*   110 */   110,  158,  165,  165,  161,  162,   26,   27,  165,  113,
- /*   120 */    16,  174,  175,   68,   69,   70,   71,   72,   73,   74,
- /*   130 */    75,   76,   77,   78,   79,   80,  118,   82,   83,   84,
- /*   140 */    85,   86,   87,   88,   89,   90,   91,   92,   19,   23,
- /*   150 */    92,   97,   98,   24,   96,   97,   98,   99,  100,  101,
- /*   160 */   102,   25,   97,  216,   60,   92,   62,  109,  221,   25,
- /*   170 */    97,   98,   99,  100,  101,  102,   86,   87,   49,   50,
- /*   180 */   118,  116,  109,   25,   94,   95,   32,   97,   88,   89,
- /*   190 */    90,   91,   92,  128,  104,   41,  106,   68,   69,   70,
- /*   200 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
- /*   210 */    11,   82,   83,   84,   85,   86,   87,   88,   89,   90,
- /*   220 */    91,   92,   19,   19,   86,   87,   88,   89,   90,   91,
- /*   230 */    92,   27,   96,  150,   66,   99,  100,  101,  112,  150,
- /*   240 */   114,  115,  138,  150,  161,  162,  110,  103,  165,  222,
- /*   250 */   223,  224,   49,   50,  165,   22,   57,   24,  165,  170,
- /*   260 */   171,  118,   94,  170,  171,   23,   98,   25,  185,  186,
- /*   270 */   243,   68,   69,   70,   71,   72,   73,   74,   75,   76,
- /*   280 */    77,   78,   79,   80,  126,   82,   83,   84,   85,   86,
- /*   290 */    87,   88,   89,   90,   91,   92,   19,  129,  130,  131,
- /*   300 */    88,   23,  172,  173,  105,  106,  107,  150,   22,   26,
- /*   310 */    27,  181,   26,   27,   22,  116,   26,   27,   26,  230,
- /*   320 */   231,  197,  165,  230,  231,  113,   49,   50,  204,  117,
- /*   330 */    96,  174,  175,   99,  100,  101,   22,   26,   27,  136,
- /*   340 */    26,   27,  118,   16,  110,   68,   69,   70,   71,   72,
- /*   350 */    73,   74,   75,   76,   77,   78,   79,   80,  118,   82,
- /*   360 */    83,   84,   85,   86,   87,   88,   89,   90,   91,   92,
- /*   370 */    19,  214,  215,  150,   23,   23,  155,   94,   95,   22,
- /*   380 */    94,   95,  116,  160,   94,   95,   94,   60,  165,   62,
- /*   390 */   112,   26,  114,  115,  128,   23,   36,  174,  175,   88,
- /*   400 */    49,   50,   57,  120,   22,   94,   95,   23,   94,   95,
- /*   410 */   120,   51,   25,  136,  169,  170,  171,  194,   58,   68,
- /*   420 */    69,   70,   71,   72,   73,   74,   75,   76,   77,   78,
- /*   430 */    79,   80,   23,   82,   83,   84,   85,   86,   87,   88,
- /*   440 */    89,   90,   91,   92,   19,  150,   12,   12,   23,  228,
- /*   450 */   105,  106,  107,   23,  233,   25,  165,   19,  150,   94,
- /*   460 */   165,  116,   28,   28,  112,  174,  114,  115,  108,  174,
- /*   470 */   175,   26,   27,  165,   49,   50,  231,   11,   44,   44,
- /*   480 */    46,   46,  174,  175,  112,  160,  114,  115,   50,   22,
- /*   490 */    23,   57,   25,   68,   69,   70,   71,   72,   73,   74,
- /*   500 */    75,   76,   77,   78,   79,   80,  119,   82,   83,   84,
- /*   510 */    85,   86,   87,   88,   89,   90,   91,   92,   19,  194,
- /*   520 */   225,   23,   23,  215,   19,   95,  105,  106,  107,  150,
- /*   530 */    23,  150,   27,   23,   67,   25,  150,  206,  207,   94,
- /*   540 */    95,  166,  104,  218,  165,   22,  165,  109,   49,   50,
- /*   550 */   120,  165,   25,  174,  175,  174,  175,   23,   21,  234,
- /*   560 */   174,  175,   22,   23,  239,   25,   25,   68,   69,   70,
- /*   570 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
- /*   580 */   205,   82,   83,   84,   85,   86,   87,   88,   89,   90,
- /*   590 */    91,   92,   19,   22,   23,  216,   23,  222,  223,  224,
- /*   600 */    63,  220,   35,  150,  150,  163,  220,   67,  166,  167,
- /*   610 */   168,  150,  169,  170,  171,  161,  162,   25,  165,  165,
- /*   620 */   150,  113,   49,   50,   25,  117,  165,  174,  175,   35,
- /*   630 */     7,    8,    9,  160,  160,  165,  120,  100,   67,  247,
- /*   640 */   248,   68,   69,   70,   71,   72,   73,   74,   75,   76,
- /*   650 */    77,   78,   79,   80,  193,   82,   83,   84,   85,   86,
- /*   660 */    87,   88,   89,   90,   91,   92,   19,  194,  194,  150,
- /*   670 */   135,   24,  137,   35,  231,  138,  150,  129,  130,  206,
- /*   680 */   207,   30,   27,  213,  165,   34,  118,   95,    0,    1,
- /*   690 */     2,  165,  218,  174,  175,   50,   49,   50,   22,   48,
- /*   700 */   174,  175,   22,   23,   23,  244,  222,  223,  224,  166,
- /*   710 */   167,  168,  120,  239,   23,   68,   69,   70,   71,   72,
- /*   720 */    73,   74,   75,   76,   77,   78,   79,   80,  150,   82,
- /*   730 */    83,   84,   85,   86,   87,   88,   89,   90,   91,   92,
- /*   740 */    19,  150,  173,  165,  181,  182,   24,   67,   26,  104,
- /*   750 */   181,  188,  174,  175,  150,   39,  165,  150,   52,  150,
- /*   760 */   150,  150,  150,  144,  145,  174,  175,  249,  250,  165,
- /*   770 */    49,   50,  165,   52,  165,  165,  165,  165,  174,  175,
- /*   780 */    29,  174,  175,  174,  175,  174,  175,  160,   22,   68,
- /*   790 */    69,   70,   71,   72,   73,   74,   75,   76,   77,   78,
- /*   800 */    79,   80,  150,   82,   83,   84,   85,   86,   87,   88,
- /*   810 */    89,   90,   91,   92,   19,  150,   94,  165,  150,  150,
- /*   820 */   160,  194,  150,  213,  160,   52,  174,  175,   23,   23,
- /*   830 */   165,   25,   22,  165,  165,  150,  150,  165,   52,  174,
- /*   840 */   175,   22,  174,  175,   49,   50,  174,  175,  190,  191,
- /*   850 */   165,  165,  240,   23,  194,   25,  187,  109,  194,  174,
- /*   860 */   175,  190,  191,   68,   69,   70,   71,   72,   73,   74,
- /*   870 */    75,   76,   77,   78,   79,   80,  150,   82,   83,   84,
- /*   880 */    85,   86,   87,   88,   89,   90,   91,   92,   19,  150,
- /*   890 */    22,  165,  150,   23,  150,   25,  150,  166,   91,   92,
- /*   900 */   174,  175,   22,  217,  165,  150,  102,  165,  150,  165,
- /*   910 */   150,  165,  150,  174,  175,   19,  174,  175,   49,   50,
- /*   920 */   165,   86,   87,  165,   23,  165,   25,  165,   24,  174,
- /*   930 */   175,  187,  174,  175,  174,  175,  205,   68,   69,   70,
- /*   940 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
- /*   950 */   150,   82,   83,   84,   85,   86,   87,   88,   89,   90,
- /*   960 */    91,   92,   19,  150,  150,  165,  150,  150,  166,   23,
- /*   970 */   150,   25,  160,   20,  174,  175,    1,    2,  165,  165,
- /*   980 */   104,  165,  165,   43,  150,  165,  240,  150,   49,   50,
- /*   990 */   174,  175,   49,   50,   23,   23,   25,   25,   53,  165,
- /*  1000 */   187,  187,  165,   23,  187,   25,  194,  205,  174,  175,
- /*  1010 */    71,   72,   69,   70,   71,   72,   73,   74,   75,   76,
- /*  1020 */    77,   78,   79,   80,  150,   82,   83,   84,   85,   86,
- /*  1030 */    87,   88,   89,   90,   91,   92,   19,   98,  150,  165,
- /*  1040 */   150,  160,  150,   59,   25,   53,  104,   22,  174,  175,
- /*  1050 */   213,  138,    5,  165,    1,  165,  150,  165,  150,  150,
- /*  1060 */   240,  150,  174,  175,  174,  175,   49,   50,  118,  150,
- /*  1070 */    35,  165,   27,  165,  165,  194,  165,  108,  127,   76,
- /*  1080 */   174,  175,  174,  175,  165,  174,  175,   70,   71,   72,
- /*  1090 */    73,   74,   75,   76,   77,   78,   79,   80,  166,   82,
- /*  1100 */    83,   84,   85,   86,   87,   88,   89,   90,   91,   92,
- /*  1110 */    19,   20,  193,   22,  150,  150,  150,   26,   27,   76,
- /*  1120 */   150,   22,    1,  150,  119,  121,  217,   20,   37,  165,
- /*  1130 */   165,  165,   16,   19,   20,  165,   22,  205,  165,  119,
- /*  1140 */    26,   27,  108,  128,  150,  150,  150,   56,  150,   22,
- /*  1150 */   150,   37,  150,  127,  160,   23,  150,   66,  193,  165,
- /*  1160 */   165,  165,   16,  165,   23,  165,  150,  165,  174,  175,
- /*  1170 */    56,  165,  150,   65,  174,  175,   15,   86,   87,   88,
- /*  1180 */    66,  165,  140,  150,   93,   94,   95,  165,  194,   98,
- /*  1190 */   174,  175,   22,    3,  164,  193,  174,  175,  165,  150,
- /*  1200 */    86,   87,    4,  180,  150,  248,  251,   93,   94,   95,
- /*  1210 */   216,  180,   98,  251,  165,  221,  150,  149,    6,  165,
- /*  1220 */   129,  130,  131,  132,  133,  134,  193,  150,  174,  175,
- /*  1230 */   116,  165,   19,   20,  150,   22,  149,  151,  150,   26,
- /*  1240 */    27,  149,  165,  129,  130,  131,  132,  133,  134,  165,
- /*  1250 */    37,  174,  175,  165,  149,   19,   20,   13,   22,  150,
- /*  1260 */   150,  150,   26,   27,  146,  147,  151,  150,   25,   56,
- /*  1270 */   152,  159,  154,   37,  165,  165,  165,  193,  160,   66,
- /*  1280 */   116,  193,  165,  174,  175,  174,  175,  194,  199,  150,
- /*  1290 */   200,  126,   56,  124,  123,  150,  201,  122,  150,   86,
- /*  1300 */    87,  150,   66,  193,  165,  202,   93,   94,   95,  150,
- /*  1310 */   165,   98,  194,  165,  125,   22,  165,  150,  150,   26,
- /*  1320 */    27,  135,   86,   87,  165,  174,  175,  203,  226,   93,
- /*  1330 */    94,   95,  165,  165,   98,  150,  218,  150,  193,  157,
- /*  1340 */   118,  157,  129,  130,  131,  132,  133,  134,    5,  104,
- /*  1350 */   165,  211,  165,   10,   11,   12,   13,   14,  150,   66,
- /*  1360 */    17,  174,  175,  210,  246,  129,  130,  131,  132,  133,
- /*  1370 */   134,  150,  210,  165,   31,  121,   33,  150,  150,   86,
- /*  1380 */    87,  176,  174,  175,  150,   42,  165,   94,  211,  210,
- /*  1390 */   150,   98,  165,  165,  211,  174,  175,  150,   55,  165,
- /*  1400 */    57,  150,  174,  175,   61,  165,  150,   64,  174,  175,
- /*  1410 */   150,  150,  165,  150,  174,  175,  165,  104,  150,  184,
- /*  1420 */   150,  165,  129,  130,  131,  165,  165,  150,  165,  150,
- /*  1430 */   150,  176,  150,  165,   47,  165,  150,  150,  176,  103,
- /*  1440 */   150,   22,  165,  178,  165,  165,  179,  165,  105,  106,
- /*  1450 */   107,  165,  165,  229,  111,  165,   92,  176,  229,  116,
- /*  1460 */   184,  176,  179,  156,  176,  176,   18,  157,  156,  237,
- /*  1470 */    45,  157,  156,  135,  157,  157,  238,  156,   68,  157,
- /*  1480 */   189,  189,  139,  219,   22,  157,   18,  192,  192,  192,
- /*  1490 */   192,  189,  219,  199,  157,  242,   40,  157,  199,  242,
- /*  1500 */   153,  157,   38,  245,  196,  166,  232,  198,  177,  177,
- /*  1510 */   232,  227,  209,  178,  166,  182,  166,  148,  177,  177,
- /*  1520 */   209,  196,  177,  199,  209,  199,  166,  208,   92,  195,
- /*  1530 */   174,  174,  183,  252,  183,  183,  252,  191,  252,  235,
- /*  1540 */   186,  241,  241,  252,  186,  252,  252,  252,  252,  252,
- /*  1550 */   252,  252,  252,  252,  252,  252,  236,
+ /*     0 */    19,   95,   53,   97,   22,   24,   24,  101,   27,   28,
+ /*    10 */    29,   30,   31,   32,   33,   34,   35,   36,   37,   38,
+ /*    20 */    39,   40,   41,  152,   43,   44,   45,   46,   47,   48,
+ /*    30 */    49,   50,   51,   52,   53,   19,   55,   55,  132,  133,
+ /*    40 */   134,    1,    2,   27,   28,   29,   30,   31,   32,   33,
+ /*    50 */    34,   35,   36,   37,   38,   39,   40,   41,  187,   43,
+ /*    60 */    44,   45,   46,   47,   48,   49,   50,   51,   52,   53,
+ /*    70 */    47,   48,   49,   50,   51,   52,   53,   61,   97,   97,
+ /*    80 */    19,   49,   50,   51,   52,   53,   70,   26,   27,   28,
+ /*    90 */    29,   30,   31,   32,   33,   34,   35,   36,   37,   38,
+ /*   100 */    39,   40,   41,  152,   43,   44,   45,   46,   47,   48,
+ /*   110 */    49,   50,   51,   52,   53,  144,  145,  146,  147,   19,
+ /*   120 */   137,   22,  139,  172,  173,   52,   53,   27,   28,   29,
+ /*   130 */    30,   31,   32,   33,   34,   35,   36,   37,   38,   39,
+ /*   140 */    40,   41,   81,   43,   44,   45,   46,   47,   48,   49,
+ /*   150 */    50,   51,   52,   53,   55,   56,   19,  152,  207,  208,
+ /*   160 */   115,   24,  117,  118,   27,   28,   29,   30,   31,   32,
+ /*   170 */    33,   34,   35,   36,   37,   38,   39,   40,   41,   79,
+ /*   180 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,
+ /*   190 */    53,   19,    0,    1,    2,   23,   97,   98,  193,   27,
+ /*   200 */    28,   29,   30,   31,   32,   33,   34,   35,   36,   37,
+ /*   210 */    38,   39,   40,   41,  152,   43,   44,   45,   46,   47,
+ /*   220 */    48,   49,   50,   51,   52,   53,   19,   22,   23,  163,
+ /*   230 */    23,   26,  190,  191,   27,   28,   29,   30,   31,   32,
+ /*   240 */    33,   34,   35,   36,   37,   38,   39,   40,   41,  187,
+ /*   250 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,
+ /*   260 */    53,   19,  196,   22,   23,   23,   49,   26,   92,   27,
+ /*   270 */    28,   29,   30,   31,   32,   33,   34,   35,   36,   37,
+ /*   280 */    38,   39,   40,   41,  172,   43,   44,   45,   46,   47,
+ /*   290 */    48,   49,   50,   51,   52,   53,   19,  221,  222,  223,
+ /*   300 */    23,   96,  119,  120,   27,   28,   29,   30,   31,   32,
+ /*   310 */    33,   34,   35,   36,   37,   38,   39,   40,   41,  172,
+ /*   320 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,
+ /*   330 */    53,   19,  152,  116,  221,  222,  223,   96,  121,   27,
+ /*   340 */    28,   29,   30,   31,   32,   33,   34,   35,   36,   37,
+ /*   350 */    38,   39,   40,   41,  241,   43,   44,   45,   46,   47,
+ /*   360 */    48,   49,   50,   51,   52,   53,   19,  157,  168,  169,
+ /*   370 */   170,   22,  190,  191,   27,   28,   29,   30,   31,   32,
+ /*   380 */    33,   34,   35,   36,   37,   38,   39,   40,   41,   30,
+ /*   390 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,
+ /*   400 */    53,   19,  172,  152,   55,   56,   24,  247,  248,   27,
+ /*   410 */    28,   29,   30,   31,   32,   33,   34,   35,   36,   37,
+ /*   420 */    38,   39,   40,   41,  152,   43,   44,   45,   46,   47,
+ /*   430 */    48,   49,   50,   51,   52,   53,  146,  147,  228,  179,
+ /*   440 */   180,  231,  185,   19,  172,  173,   97,   98,  188,   26,
+ /*   450 */   138,   27,   28,   29,   30,   31,   32,   33,   34,   35,
+ /*   460 */    36,   37,   38,   39,   40,   41,  107,   43,   44,   45,
+ /*   470 */    46,   47,   48,   49,   50,   51,   52,   53,   19,  207,
+ /*   480 */   208,   30,   31,   32,   33,  138,   27,   28,   29,   30,
+ /*   490 */    31,   32,   33,   34,   35,   36,   37,   38,   39,   40,
+ /*   500 */    41,  250,   43,   44,   45,   46,   47,   48,   49,   50,
+ /*   510 */    51,   52,   53,   19,  168,  169,  170,    7,    8,    9,
+ /*   520 */    19,  152,   28,   29,   30,   31,   32,   33,   34,   35,
+ /*   530 */    36,   37,   38,   39,   40,   41,  152,   43,   44,   45,
+ /*   540 */    46,   47,   48,   49,   50,   51,   52,   53,   19,  108,
+ /*   550 */   109,  110,  101,  130,   53,  152,  172,  173,   29,   30,
+ /*   560 */    31,   32,   33,   34,   35,   36,   37,   38,   39,   40,
+ /*   570 */    41,  152,   43,   44,   45,   46,   47,   48,   49,   50,
+ /*   580 */    51,   52,   53,   19,   20,  116,   22,   23,  169,  170,
+ /*   590 */   121,  207,   85,   55,   56,   26,   19,   20,  101,   22,
+ /*   600 */    99,  100,  101,  102,  103,  104,  105,  152,  152,  112,
+ /*   610 */   210,   47,   48,  112,  152,  108,  109,  110,   54,   55,
+ /*   620 */    56,  221,  222,  223,   47,   48,  119,  120,  172,  173,
+ /*   630 */    66,   54,   55,   56,  152,   97,   98,   99,  148,  149,
+ /*   640 */   102,  103,  104,   66,  154,   23,  156,   83,   26,  230,
+ /*   650 */   152,  113,  152,  163,  172,  173,   92,   92,   21,   95,
+ /*   660 */    83,   97,   98,  207,  208,  101,  152,   98,  186,   92,
+ /*   670 */   172,  173,   95,  218,   97,   98,  152,   99,  101,  217,
+ /*   680 */   102,  103,  104,  152,  119,  120,  196,   55,   56,   19,
+ /*   690 */    20,  113,   22,  124,  163,   11,  132,  133,  134,  135,
+ /*   700 */   136,  152,  152,  172,  173,  207,  208,  152,  152,  132,
+ /*   710 */   133,  134,  135,  136,  164,  152,   84,   47,   48,   49,
+ /*   720 */    98,  181,  152,  152,   54,   55,   56,  196,   91,   97,
+ /*   730 */    98,  160,  218,  163,  244,  164,   66,  152,  207,  208,
+ /*   740 */   103,  217,  172,  173,   19,   20,  124,   22,  193,   38,
+ /*   750 */    39,   40,   41,   83,   43,   44,   45,   46,   47,   48,
+ /*   760 */    49,   50,   51,   52,   53,   95,  196,   97,   98,   85,
+ /*   770 */   152,  101,   47,   48,  181,   85,   92,  140,  193,   54,
+ /*   780 */    55,   56,   92,   49,  195,   55,   56,  175,  163,   55,
+ /*   790 */    56,   66,  108,  109,  110,  206,  163,  242,  108,  109,
+ /*   800 */   110,  175,  132,  133,  134,  135,  136,  152,   83,   43,
+ /*   810 */    44,   45,   46,   47,   48,   49,   50,   51,   52,   53,
+ /*   820 */    95,  196,   97,   98,   55,   56,  101,   97,   98,  196,
+ /*   830 */   152,   97,   98,  221,  222,  223,  211,  212,   22,   23,
+ /*   840 */    19,   20,  181,   22,   19,  152,  152,  221,  222,  223,
+ /*   850 */   172,  173,  219,   19,  124,   30,  238,  132,  133,  134,
+ /*   860 */   135,  136,  169,  170,  186,  232,   97,   98,   47,   48,
+ /*   870 */   237,  152,  217,  152,    5,   54,   55,   56,  152,   10,
+ /*   880 */    11,   12,   13,   14,   47,   48,   17,   66,   47,   48,
+ /*   890 */    56,  172,  173,  124,  194,  195,   55,   56,  172,  173,
+ /*   900 */   152,  152,   22,  152,   83,  186,  206,  108,  109,  110,
+ /*   910 */    22,   23,   96,  152,  193,   12,   95,  152,   97,   98,
+ /*   920 */   172,  173,  101,  230,  152,  164,   12,   47,   48,   60,
+ /*   930 */   152,   62,  107,  207,  186,   55,   56,  112,   97,   98,
+ /*   940 */    71,  100,  193,  152,  183,  152,  185,  152,  107,  152,
+ /*   950 */   109,   82,   16,  132,  133,  134,  135,  136,   89,  152,
+ /*   960 */    57,   92,   93,  172,  173,  172,  173,  172,  173,  132,
+ /*   970 */   133,   57,  152,  132,  133,   95,   73,   97,   75,   55,
+ /*   980 */    56,  101,  163,  114,   96,  245,  246,   73,   85,   75,
+ /*   990 */    38,   39,   40,   41,   42,   43,   44,   45,   46,   47,
+ /*  1000 */    48,   49,   50,   51,   52,   53,  194,  195,  152,  171,
+ /*  1010 */   141,  152,  132,  133,  134,  196,  225,  179,  206,   65,
+ /*  1020 */   152,   97,   98,  152,   88,  152,   90,  152,  172,  173,
+ /*  1030 */   152,  219,   78,  152,  152,  238,  152,  152,  219,  152,
+ /*  1040 */    86,  152,  152,  172,  173,  238,  152,  172,  173,  152,
+ /*  1050 */   172,  173,  152,  172,  173,  213,  237,  172,  173,  172,
+ /*  1060 */   173,  172,  173,  211,  212,  111,  172,  173,  152,  172,
+ /*  1070 */   173,  152,  172,  173,  152,  193,  140,  193,  152,   59,
+ /*  1080 */   152,  152,  152,   63,  152,   16,  152,  152,  172,  173,
+ /*  1090 */   152,  172,  173,  152,  172,  173,  152,   77,  172,  173,
+ /*  1100 */   172,  173,  172,  173,  172,  173,  172,  173,  152,  250,
+ /*  1110 */   172,  173,   61,  172,  173,  152,  172,  173,  152,   92,
+ /*  1120 */   152,   70,  152,  152,  152,   26,  152,  100,  172,  173,
+ /*  1130 */   152,   24,  152,   22,  152,  172,  173,  152,  172,  173,
+ /*  1140 */   172,  173,  172,  173,  172,  173,  172,  173,  152,  152,
+ /*  1150 */   172,  173,  172,  173,  172,  173,  152,   88,  152,   90,
+ /*  1160 */   152,   55,   55,  152,  193,  152,   55,  152,  172,  173,
+ /*  1170 */    26,  152,  163,  163,  152,   19,  172,  173,  172,  173,
+ /*  1180 */   172,  173,   22,  172,  173,  172,  173,  172,  173,   55,
+ /*  1190 */   193,  172,  173,  152,  172,  173,  166,  167,  166,  167,
+ /*  1200 */   163,  163,  163,   97,   97,  196,  196,  163,   97,   55,
+ /*  1210 */    23,  199,   56,   26,   22,   22,   24,  100,  101,   55,
+ /*  1220 */    23,  209,  123,   26,   23,   23,   23,   26,   26,   26,
+ /*  1230 */    37,   97,  152,  196,  196,  196,   23,    7,    8,   26,
+ /*  1240 */   196,   23,   23,  152,   26,   26,   23,  132,  133,   26,
+ /*  1250 */   106,   97,  132,  133,   23,  152,  152,   26,  210,  191,
+ /*  1260 */   152,   97,  152,  234,  152,  152,  152,  233,  152,  210,
+ /*  1270 */   152,  152,  210,  152,  152,  152,  152,  152,  152,  197,
+ /*  1280 */   210,  198,  122,  150,  239,  201,  214,  214,  201,  239,
+ /*  1290 */   214,  227,  200,  184,  198,  155,   67,  243,  122,   22,
+ /*  1300 */   159,  159,   69,  176,  175,  175,  175,  240,  180,  159,
+ /*  1310 */   220,  240,   27,  130,   18,   18,  159,  158,  220,  137,
+ /*  1320 */   159,  189,  236,  158,   74,  159,  159,  158,  192,  192,
+ /*  1330 */   192,  192,  235,   22,  189,  189,  201,  159,  158,  177,
+ /*  1340 */   159,  107,  158,   76,  201,  177,  174,  174,  201,  174,
+ /*  1350 */   106,  177,  182,  174,  107,  159,   22,  125,  159,  182,
+ /*  1360 */   174,  176,  174,  174,  216,  216,  215,  215,  177,  216,
+ /*  1370 */   215,   53,  137,  128,  216,  177,  127,  129,  215,  126,
+ /*  1380 */    25,   13,  162,   26,    6,  161,  165,  165,  178,  153,
+ /*  1390 */   153,  151,  151,  151,  151,  224,    4,    3,   22,  142,
+ /*  1400 */    15,   94,   16,  178,  165,  205,   23,  202,  204,  203,
+ /*  1410 */   201,   23,  120,  131,  111,   20,  226,  123,  125,   16,
+ /*  1420 */     1,  123,  131,  229,  229,  111,   37,   37,   56,   64,
+ /*  1430 */   122,    1,    5,   22,  107,  140,   80,   87,   26,   80,
+ /*  1440 */   107,   72,   24,   20,   19,  105,   22,  112,   22,   79,
+ /*  1450 */    22,   58,   23,   22,   79,   22,  249,  249,  246,   79,
+ /*  1460 */    23,   23,   23,  116,   68,   22,   26,   23,   22,   56,
+ /*  1470 */   122,   23,   23,   64,   22,  124,   26,   26,   64,   64,
+ /*  1480 */    23,   23,   23,   23,   11,   23,   22,   26,   23,   22,
+ /*  1490 */    24,    1,   23,   22,   26,  122,   24,   23,   22,  122,
+ /*  1500 */    23,   23,   22,  122,  122,   23,   15,
 };
-#define YY_SHIFT_USE_DFLT (-74)
-#define YY_SHIFT_COUNT (418)
-#define YY_SHIFT_MIN   (-73)
-#define YY_SHIFT_MAX   (1468)
+#define YY_SHIFT_USE_DFLT (-95)
+#define YY_SHIFT_COUNT (442)
+#define YY_SHIFT_MIN   (-94)
+#define YY_SHIFT_MAX   (1491)
 static const short yy_shift_ofst[] = {
- /*     0 */   975, 1114, 1343, 1114, 1213, 1213,   90,   90,    0,  -19,
- /*    10 */  1213, 1213, 1213, 1213, 1213,  345,  445,  721, 1091, 1213,
- /*    20 */  1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213,
- /*    30 */  1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213,
- /*    40 */  1213, 1213, 1213, 1213, 1213, 1213, 1213, 1236, 1213, 1213,
- /*    50 */  1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213, 1213,
- /*    60 */  1213,  199,  445,  445,  835,  835,  365, 1164,   55,  647,
- /*    70 */   573,  499,  425,  351,  277,  203,  129,  795,  795,  795,
- /*    80 */   795,  795,  795,  795,  795,  795,  795,  795,  795,  795,
- /*    90 */   795,  795,  795,  795,  795,  869,  795,  943, 1017, 1017,
- /*   100 */   -69,  -45,  -45,  -45,  -45,  -45,   -1,   58,  138,  100,
- /*   110 */   445,  445,  445,  445,  445,  445,  445,  445,  445,  445,
- /*   120 */   445,  445,  445,  445,  445,  445,  537,  438,  445,  445,
- /*   130 */   445,  445,  445,  365,  807, 1436,  -74,  -74,  -74, 1293,
- /*   140 */    73,  434,  434,  311,  314,  290,  283,  286,  540,  467,
- /*   150 */   445,  445,  445,  445,  445,  445,  445,  445,  445,  445,
- /*   160 */   445,  445,  445,  445,  445,  445,  445,  445,  445,  445,
- /*   170 */   445,  445,  445,  445,  445,  445,  445,  445,  445,  445,
- /*   180 */   445,  445,   65,  722,  722,  722,  688,  266, 1164, 1164,
- /*   190 */  1164,  -74,  -74,  -74,  136,  168,  168,  234,  360,  360,
- /*   200 */   360,  430,  372,  435,  352,  278,  126,  -36,  -36,  -36,
- /*   210 */   -36,  421,  651,  -36,  -36,  592,  292,  212,  623,  158,
- /*   220 */   204,  204,  505,  158,  505,  144,  365,  154,  365,  154,
- /*   230 */   645,  154,  204,  154,  154,  535,  548,  548,  365,  387,
- /*   240 */   508,  233, 1464, 1222, 1222, 1456, 1456, 1222, 1462, 1410,
- /*   250 */  1165, 1468, 1468, 1468, 1468, 1222, 1165, 1462, 1410, 1410,
- /*   260 */  1222, 1448, 1338, 1425, 1222, 1222, 1448, 1222, 1448, 1222,
- /*   270 */  1448, 1419, 1313, 1313, 1313, 1387, 1364, 1364, 1419, 1313,
- /*   280 */  1336, 1313, 1387, 1313, 1313, 1254, 1245, 1254, 1245, 1254,
- /*   290 */  1245, 1222, 1222, 1186, 1189, 1175, 1169, 1171, 1165, 1164,
- /*   300 */  1243, 1244, 1244, 1212, 1212, 1212, 1212,  -74,  -74,  -74,
- /*   310 */   -74,  -74,  -74,  939,  104,  680,  571,  327,    1,  980,
- /*   320 */    26,  972,  971,  946,  901,  870,  830,  806,   54,   21,
- /*   330 */   -73,  510,  242, 1198, 1190, 1170, 1042, 1161, 1108, 1146,
- /*   340 */  1141, 1132, 1015, 1127, 1026, 1034, 1020, 1107, 1004, 1116,
- /*   350 */  1121, 1005, 1099,  951, 1043, 1003,  969, 1045, 1035,  950,
- /*   360 */  1053, 1047, 1025,  942,  913,  992, 1019,  945,  984,  940,
- /*   370 */   876,  904,  953,  896,  748,  804,  880,  786,  868,  819,
- /*   380 */   805,  810,  773,  751,  766,  706,  716,  691,  681,  568,
- /*   390 */   655,  638,  676,  516,  541,  594,  599,  567,  541,  534,
- /*   400 */   507,  527,  498,  523,  466,  382,  409,  384,  357,    6,
- /*   410 */   240,  224,  143,   62,   18,   71,   39,    9,    5,
+ /*     0 */    40,  564,  869,  577,  725,  725,  725,  725,  690,  -19,
+ /*    10 */    16,   16,  100,  725,  725,  725,  725,  725,  725,  725,
+ /*    20 */   841,  841,  538,  507,  684,  565,   61,  137,  172,  207,
+ /*    30 */   242,  277,  312,  347,  382,  424,  424,  424,  424,  424,
+ /*    40 */   424,  424,  424,  424,  424,  424,  424,  424,  424,  424,
+ /*    50 */   459,  424,  494,  529,  529,  670,  725,  725,  725,  725,
+ /*    60 */   725,  725,  725,  725,  725,  725,  725,  725,  725,  725,
+ /*    70 */   725,  725,  725,  725,  725,  725,  725,  725,  725,  725,
+ /*    80 */   725,  725,  725,  725,  821,  725,  725,  725,  725,  725,
+ /*    90 */   725,  725,  725,  725,  725,  725,  725,  725,  952,  711,
+ /*   100 */   711,  711,  711,  711,  766,   23,   32,  924,  637,  825,
+ /*   110 */   837,  837,  924,   73,  183,  -51,  -95,  -95,  -95,  501,
+ /*   120 */   501,  501,  903,  903,  632,  205,  241,  924,  924,  924,
+ /*   130 */   924,  924,  924,  924,  924,  924,  924,  924,  924,  924,
+ /*   140 */   924,  924,  924,  924,  924,  924,  924,  192, 1027, 1106,
+ /*   150 */  1106,  183,  176,  176,  176,  176,  176,  176,  -95,  -95,
+ /*   160 */   -95,  880,  -94,  -94,  578,  734,   99,  730,  769,  349,
+ /*   170 */   924,  924,  924,  924,  924,  924,  924,  924,  924,  924,
+ /*   180 */   924,  924,  924,  924,  924,  924,  924,  954,  954,  954,
+ /*   190 */   924,  924,  622,  924,  924,  924,  -18,  924,  924,  914,
+ /*   200 */   924,  924,  924,  924,  924,  924,  924,  924,  924,  924,
+ /*   210 */   441, 1020, 1107, 1107, 1107,  569,   45,  217,  510,  423,
+ /*   220 */   834,  834, 1156,  423, 1156, 1144, 1187,  359, 1051,  834,
+ /*   230 */   -17, 1051, 1051, 1099,  469, 1192, 1229, 1176, 1176, 1233,
+ /*   240 */  1233, 1176, 1277, 1285, 1183, 1296, 1296, 1296, 1296, 1176,
+ /*   250 */  1297, 1183, 1277, 1285, 1285, 1183, 1176, 1297, 1182, 1250,
+ /*   260 */  1176, 1176, 1297, 1311, 1176, 1297, 1176, 1297, 1311, 1234,
+ /*   270 */  1234, 1234, 1267, 1311, 1234, 1244, 1234, 1267, 1234, 1234,
+ /*   280 */  1232, 1247, 1232, 1247, 1232, 1247, 1232, 1247, 1176, 1334,
+ /*   290 */  1176, 1235, 1311, 1318, 1318, 1311, 1248, 1253, 1245, 1249,
+ /*   300 */  1183, 1355, 1357, 1368, 1368, 1378, 1378, 1378, 1378,  -95,
+ /*   310 */   -95,  -95,  -95,  -95,  -95,  -95,  -95,  451,  936,  816,
+ /*   320 */   888, 1069,  799, 1111, 1197, 1193, 1201, 1202, 1203, 1213,
+ /*   330 */  1134, 1117, 1230,  497, 1218, 1219, 1154, 1223, 1115, 1120,
+ /*   340 */  1231, 1164, 1160, 1392, 1394, 1376, 1257, 1385, 1307, 1386,
+ /*   350 */  1383, 1388, 1292, 1282, 1303, 1294, 1395, 1293, 1403, 1419,
+ /*   360 */  1298, 1291, 1389, 1390, 1314, 1372, 1365, 1308, 1430, 1427,
+ /*   370 */  1411, 1327, 1295, 1356, 1412, 1359, 1350, 1369, 1333, 1418,
+ /*   380 */  1423, 1425, 1335, 1340, 1424, 1370, 1426, 1428, 1429, 1431,
+ /*   390 */  1375, 1393, 1433, 1380, 1396, 1437, 1438, 1439, 1347, 1443,
+ /*   400 */  1444, 1446, 1440, 1348, 1448, 1449, 1413, 1409, 1452, 1351,
+ /*   410 */  1450, 1414, 1451, 1415, 1457, 1450, 1458, 1459, 1460, 1461,
+ /*   420 */  1462, 1464, 1473, 1465, 1467, 1466, 1468, 1469, 1471, 1472,
+ /*   430 */  1468, 1474, 1476, 1477, 1478, 1480, 1373, 1377, 1381, 1382,
+ /*   440 */  1482, 1491, 1490,
 };
-#define YY_REDUCE_USE_DFLT (-142)
-#define YY_REDUCE_COUNT (312)
-#define YY_REDUCE_MIN   (-141)
-#define YY_REDUCE_MAX   (1369)
+#define YY_REDUCE_USE_DFLT (-130)
+#define YY_REDUCE_COUNT (316)
+#define YY_REDUCE_MIN   (-129)
+#define YY_REDUCE_MAX   (1243)
 static const short yy_reduce_ofst[] = {
- /*     0 */  -141,  994, 1118,  223,  157,  -53,   93,   89,   83,  375,
- /*    10 */   386,  381,  379,  308,  295,  325,  -47,   27, 1240, 1234,
- /*    20 */  1228, 1221, 1208, 1187, 1151, 1111, 1109, 1077, 1054, 1022,
- /*    30 */  1016, 1000,  911,  908,  906,  890,  888,  874,  834,  816,
- /*    40 */   800,  760,  758,  755,  742,  739,  726,  685,  672,  668,
- /*    50 */   665,  652,  611,  609,  607,  604,  591,  578,  526,  519,
- /*    60 */   453,  474,  454,  461,  443,  245,  442,  473,  484,  484,
- /*    70 */   484,  484,  484,  484,  484,  484,  484,  484,  484,  484,
- /*    80 */   484,  484,  484,  484,  484,  484,  484,  484,  484,  484,
- /*    90 */   484,  484,  484,  484,  484,  484,  484,  484,  484,  484,
- /*   100 */   484,  484,  484,  484,  484,  484,  484,  130,  484,  484,
- /*   110 */  1145,  909, 1110, 1088, 1084, 1033, 1002,  965,  820,  837,
- /*   120 */   746,  686,  612,  817,  610,  919,  221,  563,  814,  813,
- /*   130 */   744,  669,  470,  543,  484,  484,  484,  484,  484,  291,
- /*   140 */   569,  671,  658,  970, 1290, 1287, 1286, 1282,  518,  518,
- /*   150 */  1280, 1279, 1277, 1270, 1268, 1263, 1261, 1260, 1256, 1251,
- /*   160 */  1247, 1227, 1185, 1168, 1167, 1159, 1148, 1139, 1117, 1066,
- /*   170 */  1049, 1006,  998,  996,  995,  973,  970,  966,  964,  892,
- /*   180 */   762,  -52,  881,  932,  802,  731,  619,  812,  664,  660,
- /*   190 */   627,  392,  331,  124, 1358, 1357, 1356, 1354, 1352, 1351,
- /*   200 */  1349, 1319, 1334, 1346, 1334, 1334, 1334, 1334, 1334, 1334,
- /*   210 */  1334, 1320, 1304, 1334, 1334, 1319, 1360, 1325, 1369, 1326,
- /*   220 */  1315, 1311, 1301, 1324, 1300, 1335, 1350, 1345, 1348, 1342,
- /*   230 */  1333, 1341, 1303, 1332, 1331, 1284, 1278, 1274, 1339, 1309,
- /*   240 */  1308, 1347, 1258, 1344, 1340, 1257, 1253, 1337, 1273, 1302,
- /*   250 */  1299, 1298, 1297, 1296, 1295, 1328, 1294, 1264, 1292, 1291,
- /*   260 */  1322, 1321, 1238, 1232, 1318, 1317, 1316, 1314, 1312, 1310,
- /*   270 */  1307, 1283, 1289, 1288, 1285, 1276, 1229, 1224, 1267, 1281,
- /*   280 */  1265, 1262, 1235, 1255, 1205, 1183, 1179, 1177, 1162, 1140,
- /*   290 */  1153, 1184, 1182, 1102, 1124, 1103, 1095, 1090, 1089, 1093,
- /*   300 */  1112, 1115, 1086, 1105, 1092, 1087, 1068,  962,  955,  957,
- /*   310 */  1031, 1023, 1030,
+ /*     0 */   -29,  531,  490,  570,  -49,  272,  456,  498,  633,  400,
+ /*    10 */   612,  626,  113,  482,  678,  719,  384,  726,  748,  791,
+ /*    20 */   419,  693,  761,  812,  819,  625,   76,   76,   76,   76,
+ /*    30 */    76,   76,   76,   76,   76,   76,   76,   76,   76,   76,
+ /*    40 */    76,   76,   76,   76,   76,   76,   76,   76,   76,   76,
+ /*    50 */    76,   76,   76,   76,   76,  793,  795,  856,  871,  875,
+ /*    60 */   878,  881,  885,  887,  889,  894,  897,  900,  916,  919,
+ /*    70 */   922,  926,  928,  930,  932,  934,  938,  941,  944,  956,
+ /*    80 */   963,  966,  968,  970,  972,  974,  978,  980,  982,  996,
+ /*    90 */  1004, 1006, 1008, 1011, 1013, 1015, 1019, 1022,   76,   76,
+ /*   100 */    76,   76,   76,   76,   76,   76,   76,  555,  210,  260,
+ /*   110 */   200,  346,  571,   76,  700,   76,   76,   76,   76,  838,
+ /*   120 */   838,  838,   42,  182,  251,  160,  160,  550,    5,  455,
+ /*   130 */   585,  721,  749,  882,  884,  971,  618,  462,  797,  514,
+ /*   140 */   807,  524,  997, -129,  655,  859,   62,  290,   66, 1030,
+ /*   150 */  1032,  589, 1009, 1010, 1037, 1038, 1039, 1044,  740,  852,
+ /*   160 */  1012,  112,  147,  230,  257,  180,  369,  403,  500,  549,
+ /*   170 */   556,  563,  694,  751,  765,  772,  778,  820,  868,  873,
+ /*   180 */   890,  929,  935,  985, 1041, 1080, 1091,  540,  593,  661,
+ /*   190 */  1103, 1104,  842, 1108, 1110, 1112, 1048, 1113, 1114, 1068,
+ /*   200 */  1116, 1118, 1119,  180, 1121, 1122, 1123, 1124, 1125, 1126,
+ /*   210 */  1029, 1034, 1059, 1062, 1070,  842, 1082, 1083, 1133, 1084,
+ /*   220 */  1072, 1073, 1045, 1087, 1050, 1127, 1109, 1128, 1129, 1076,
+ /*   230 */  1064, 1130, 1131, 1092, 1096, 1140, 1054, 1141, 1142, 1067,
+ /*   240 */  1071, 1150, 1090, 1132, 1135, 1136, 1137, 1138, 1139, 1157,
+ /*   250 */  1159, 1143, 1098, 1145, 1146, 1147, 1161, 1165, 1086, 1097,
+ /*   260 */  1166, 1167, 1169, 1162, 1178, 1180, 1181, 1184, 1168, 1172,
+ /*   270 */  1173, 1175, 1170, 1174, 1179, 1185, 1186, 1177, 1188, 1189,
+ /*   280 */  1148, 1151, 1149, 1152, 1153, 1155, 1158, 1163, 1196, 1171,
+ /*   290 */  1199, 1190, 1191, 1194, 1195, 1198, 1200, 1204, 1206, 1205,
+ /*   300 */  1209, 1220, 1224, 1236, 1237, 1240, 1241, 1242, 1243, 1207,
+ /*   310 */  1208, 1212, 1221, 1222, 1210, 1225, 1239,
 };
 static const YYACTIONTYPE yy_default[] = {
- /*     0 */   635,  870,  959,  959,  959,  870,  899,  899,  959,  759,
- /*    10 */   959,  959,  959,  959,  868,  959,  959,  933,  959,  959,
- /*    20 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*    30 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*    40 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*    50 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*    60 */   959,  959,  959,  959,  899,  899,  674,  763,  794,  959,
- /*    70 */   959,  959,  959,  959,  959,  959,  959,  932,  934,  809,
- /*    80 */   808,  802,  801,  912,  774,  799,  792,  785,  796,  871,
- /*    90 */   864,  865,  863,  867,  872,  959,  795,  831,  848,  830,
- /*   100 */   842,  847,  854,  846,  843,  833,  832,  666,  834,  835,
- /*   110 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   120 */   959,  959,  959,  959,  959,  959,  661,  728,  959,  959,
- /*   130 */   959,  959,  959,  959,  836,  837,  851,  850,  849,  959,
- /*   140 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   150 */   959,  939,  937,  959,  883,  959,  959,  959,  959,  959,
- /*   160 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   170 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   180 */   959,  641,  959,  759,  759,  759,  635,  959,  959,  959,
- /*   190 */   959,  951,  763,  753,  719,  959,  959,  959,  959,  959,
- /*   200 */   959,  959,  959,  959,  959,  959,  959,  804,  742,  922,
- /*   210 */   924,  959,  905,  740,  663,  761,  676,  751,  643,  798,
- /*   220 */   776,  776,  917,  798,  917,  700,  959,  788,  959,  788,
- /*   230 */   697,  788,  776,  788,  788,  866,  959,  959,  959,  760,
- /*   240 */   751,  959,  944,  767,  767,  936,  936,  767,  810,  732,
- /*   250 */   798,  739,  739,  739,  739,  767,  798,  810,  732,  732,
- /*   260 */   767,  658,  911,  909,  767,  767,  658,  767,  658,  767,
- /*   270 */   658,  876,  730,  730,  730,  715,  880,  880,  876,  730,
- /*   280 */   700,  730,  715,  730,  730,  780,  775,  780,  775,  780,
- /*   290 */   775,  767,  767,  959,  793,  781,  791,  789,  798,  959,
- /*   300 */   718,  651,  651,  640,  640,  640,  640,  956,  956,  951,
- /*   310 */   702,  702,  684,  959,  959,  959,  959,  959,  959,  959,
- /*   320 */   885,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   330 */   959,  959,  959,  959,  636,  946,  959,  959,  943,  959,
- /*   340 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   350 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  915,
- /*   360 */   959,  959,  959,  959,  959,  959,  908,  907,  959,  959,
- /*   370 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   380 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  959,
- /*   390 */   959,  959,  959,  959,  790,  959,  782,  959,  869,  959,
- /*   400 */   959,  959,  959,  959,  959,  959,  959,  959,  959,  745,
- /*   410 */   819,  959,  818,  822,  817,  668,  959,  649,  959,  632,
- /*   420 */   637,  955,  958,  957,  954,  953,  952,  947,  945,  942,
- /*   430 */   941,  940,  938,  935,  931,  889,  887,  894,  893,  892,
- /*   440 */   891,  890,  888,  886,  884,  805,  803,  800,  797,  930,
- /*   450 */   882,  741,  738,  737,  657,  948,  914,  923,  921,  811,
- /*   460 */   920,  919,  918,  916,  913,  900,  807,  806,  733,  874,
- /*   470 */   873,  660,  904,  903,  902,  906,  910,  901,  769,  659,
- /*   480 */   656,  665,  722,  721,  729,  727,  726,  725,  724,  723,
- /*   490 */   720,  667,  675,  686,  714,  699,  698,  879,  881,  878,
- /*   500 */   877,  707,  706,  712,  711,  710,  709,  708,  705,  704,
- /*   510 */   703,  696,  695,  701,  694,  717,  716,  713,  693,  736,
- /*   520 */   735,  734,  731,  692,  691,  690,  822,  689,  688,  828,
- /*   530 */   827,  815,  858,  756,  755,  754,  766,  765,  778,  777,
- /*   540 */   813,  812,  779,  764,  758,  757,  773,  772,  771,  770,
- /*   550 */   762,  752,  784,  787,  786,  783,  860,  768,  857,  929,
- /*   560 */   928,  927,  926,  925,  862,  861,  829,  826,  679,  680,
- /*   570 */   898,  896,  897,  895,  682,  681,  678,  677,  859,  747,
- /*   580 */   746,  855,  852,  844,  840,  856,  853,  845,  841,  839,
- /*   590 */   838,  824,  823,  821,  820,  816,  825,  670,  748,  744,
- /*   600 */   743,  814,  750,  749,  687,  685,  683,  664,  662,  655,
- /*   610 */   653,  652,  654,  650,  648,  647,  646,  645,  644,  673,
- /*   620 */   672,  671,  669,  668,  642,  639,  638,  634,  633,  631,
+ /*     0 */  1258, 1248, 1248, 1248, 1180, 1180, 1180, 1180, 1248, 1077,
+ /*    10 */  1106, 1106, 1232, 1309, 1309, 1309, 1309, 1309, 1309, 1179,
+ /*    20 */  1309, 1309, 1309, 1309, 1248, 1081, 1112, 1309, 1309, 1309,
+ /*    30 */  1309, 1309, 1309, 1309, 1309, 1231, 1233, 1120, 1119, 1214,
+ /*    40 */  1093, 1117, 1110, 1114, 1181, 1175, 1176, 1174, 1178, 1182,
+ /*    50 */  1309, 1113, 1144, 1159, 1143, 1309, 1309, 1309, 1309, 1309,
+ /*    60 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*    70 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*    80 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*    90 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1153, 1158,
+ /*   100 */  1165, 1157, 1154, 1146, 1145, 1147, 1148, 1309, 1000, 1048,
+ /*   110 */  1309, 1309, 1309, 1149, 1309, 1150, 1162, 1161, 1160, 1239,
+ /*   120 */  1266, 1265, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   130 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   140 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1258, 1248, 1006,
+ /*   150 */  1006, 1309, 1248, 1248, 1248, 1248, 1248, 1248, 1244, 1081,
+ /*   160 */  1072, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   170 */  1309, 1236, 1234, 1309, 1195, 1309, 1309, 1309, 1309, 1309,
+ /*   180 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   190 */  1309, 1309, 1309, 1309, 1309, 1309, 1077, 1309, 1309, 1309,
+ /*   200 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1260,
+ /*   210 */  1309, 1209, 1077, 1077, 1077, 1079, 1061, 1071,  985, 1116,
+ /*   220 */  1095, 1095, 1298, 1116, 1298, 1023, 1280, 1020, 1106, 1095,
+ /*   230 */  1177, 1106, 1106, 1078, 1071, 1309, 1301, 1086, 1086, 1300,
+ /*   240 */  1300, 1086, 1125, 1051, 1116, 1057, 1057, 1057, 1057, 1086,
+ /*   250 */   997, 1116, 1125, 1051, 1051, 1116, 1086,  997, 1213, 1295,
+ /*   260 */  1086, 1086,  997, 1188, 1086,  997, 1086,  997, 1188, 1049,
+ /*   270 */  1049, 1049, 1038, 1188, 1049, 1023, 1049, 1038, 1049, 1049,
+ /*   280 */  1099, 1094, 1099, 1094, 1099, 1094, 1099, 1094, 1086, 1183,
+ /*   290 */  1086, 1309, 1188, 1192, 1192, 1188, 1111, 1100, 1109, 1107,
+ /*   300 */  1116, 1003, 1041, 1263, 1263, 1259, 1259, 1259, 1259, 1306,
+ /*   310 */  1306, 1244, 1275, 1275, 1025, 1025, 1275, 1309, 1309, 1309,
+ /*   320 */  1309, 1309, 1309, 1270, 1309, 1197, 1309, 1309, 1309, 1309,
+ /*   330 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   340 */  1309, 1309, 1131, 1309,  981, 1241, 1309, 1309, 1240, 1309,
+ /*   350 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   360 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1297, 1309, 1309,
+ /*   370 */  1309, 1309, 1309, 1309, 1212, 1211, 1309, 1309, 1309, 1309,
+ /*   380 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   390 */  1309, 1309, 1309, 1309, 1309, 1309, 1309, 1309, 1063, 1309,
+ /*   400 */  1309, 1309, 1284, 1309, 1309, 1309, 1309, 1309, 1309, 1309,
+ /*   410 */  1108, 1309, 1101, 1309, 1309, 1288, 1309, 1309, 1309, 1309,
+ /*   420 */  1309, 1309, 1309, 1309, 1309, 1309, 1250, 1309, 1309, 1309,
+ /*   430 */  1249, 1309, 1309, 1309, 1309, 1309, 1133, 1309, 1132, 1136,
+ /*   440 */  1309,  991, 1309,
 };
+/********** End of lemon-generated parsing tables *****************************/
 
-/* The next table maps tokens into fallback tokens.  If a construct
-** like the following:
+/* The next table maps tokens (terminal symbols) into fallback tokens.  
+** If a construct like the following:
 ** 
 **      %fallback ID X Y Z.
 **
@@ -106684,76 +132360,109 @@ static const YYACTIONTYPE yy_default[] = {
 ** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
 ** but it does not parse, the type of the token is changed to ID and
 ** the parse is retried before an error is thrown.
+**
+** This feature can be used, for example, to cause some keywords in a language
+** to revert to identifiers if they keyword does not apply in the context where
+** it appears.
 */
 #ifdef YYFALLBACK
 static const YYCODETYPE yyFallback[] = {
     0,  /*          $ => nothing */
     0,  /*       SEMI => nothing */
-   26,  /*    EXPLAIN => ID */
-   26,  /*      QUERY => ID */
-   26,  /*       PLAN => ID */
-   26,  /*      BEGIN => ID */
+   55,  /*    EXPLAIN => ID */
+   55,  /*      QUERY => ID */
+   55,  /*       PLAN => ID */
+   55,  /*      BEGIN => ID */
     0,  /* TRANSACTION => nothing */
-   26,  /*   DEFERRED => ID */
-   26,  /*  IMMEDIATE => ID */
-   26,  /*  EXCLUSIVE => ID */
+   55,  /*   DEFERRED => ID */
+   55,  /*  IMMEDIATE => ID */
+   55,  /*  EXCLUSIVE => ID */
     0,  /*     COMMIT => nothing */
-   26,  /*        END => ID */
-   26,  /*   ROLLBACK => ID */
-   26,  /*  SAVEPOINT => ID */
-   26,  /*    RELEASE => ID */
+   55,  /*        END => ID */
+   55,  /*   ROLLBACK => ID */
+   55,  /*  SAVEPOINT => ID */
+   55,  /*    RELEASE => ID */
     0,  /*         TO => nothing */
     0,  /*      TABLE => nothing */
     0,  /*     CREATE => nothing */
-   26,  /*         IF => ID */
+   55,  /*         IF => ID */
     0,  /*        NOT => nothing */
     0,  /*     EXISTS => nothing */
-   26,  /*       TEMP => ID */
+   55,  /*       TEMP => ID */
     0,  /*         LP => nothing */
     0,  /*         RP => nothing */
     0,  /*         AS => nothing */
+   55,  /*    WITHOUT => ID */
     0,  /*      COMMA => nothing */
+    0,  /*         OR => nothing */
+    0,  /*        AND => nothing */
+    0,  /*         IS => nothing */
+   55,  /*      MATCH => ID */
+   55,  /*    LIKE_KW => ID */
+    0,  /*    BETWEEN => nothing */
+    0,  /*         IN => nothing */
+    0,  /*     ISNULL => nothing */
+    0,  /*    NOTNULL => nothing */
+    0,  /*         NE => nothing */
+    0,  /*         EQ => nothing */
+    0,  /*         GT => nothing */
+    0,  /*         LE => nothing */
+    0,  /*         LT => nothing */
+    0,  /*         GE => nothing */
+    0,  /*     ESCAPE => nothing */
+    0,  /*     BITAND => nothing */
+    0,  /*      BITOR => nothing */
+    0,  /*     LSHIFT => nothing */
+    0,  /*     RSHIFT => nothing */
+    0,  /*       PLUS => nothing */
+    0,  /*      MINUS => nothing */
+    0,  /*       STAR => nothing */
+    0,  /*      SLASH => nothing */
+    0,  /*        REM => nothing */
+    0,  /*     CONCAT => nothing */
+    0,  /*    COLLATE => nothing */
+    0,  /*     BITNOT => nothing */
     0,  /*         ID => nothing */
     0,  /*    INDEXED => nothing */
-   26,  /*      ABORT => ID */
-   26,  /*     ACTION => ID */
-   26,  /*      AFTER => ID */
-   26,  /*    ANALYZE => ID */
-   26,  /*        ASC => ID */
-   26,  /*     ATTACH => ID */
-   26,  /*     BEFORE => ID */
-   26,  /*         BY => ID */
-   26,  /*    CASCADE => ID */
-   26,  /*       CAST => ID */
-   26,  /*   COLUMNKW => ID */
-   26,  /*   CONFLICT => ID */
-   26,  /*   DATABASE => ID */
-   26,  /*       DESC => ID */
-   26,  /*     DETACH => ID */
-   26,  /*       EACH => ID */
-   26,  /*       FAIL => ID */
-   26,  /*        FOR => ID */
-   26,  /*     IGNORE => ID */
-   26,  /*  INITIALLY => ID */
-   26,  /*    INSTEAD => ID */
-   26,  /*    LIKE_KW => ID */
-   26,  /*      MATCH => ID */
-   26,  /*         NO => ID */
-   26,  /*        KEY => ID */
-   26,  /*         OF => ID */
-   26,  /*     OFFSET => ID */
-   26,  /*     PRAGMA => ID */
-   26,  /*      RAISE => ID */
-   26,  /*    REPLACE => ID */
-   26,  /*   RESTRICT => ID */
-   26,  /*        ROW => ID */
-   26,  /*    TRIGGER => ID */
-   26,  /*     VACUUM => ID */
-   26,  /*       VIEW => ID */
-   26,  /*    VIRTUAL => ID */
-   26,  /*    REINDEX => ID */
-   26,  /*     RENAME => ID */
-   26,  /*   CTIME_KW => ID */
+   55,  /*      ABORT => ID */
+   55,  /*     ACTION => ID */
+   55,  /*      AFTER => ID */
+   55,  /*    ANALYZE => ID */
+   55,  /*        ASC => ID */
+   55,  /*     ATTACH => ID */
+   55,  /*     BEFORE => ID */
+   55,  /*         BY => ID */
+   55,  /*    CASCADE => ID */
+   55,  /*       CAST => ID */
+   55,  /*   COLUMNKW => ID */
+   55,  /*   CONFLICT => ID */
+   55,  /*   DATABASE => ID */
+   55,  /*       DESC => ID */
+   55,  /*     DETACH => ID */
+   55,  /*       EACH => ID */
+   55,  /*       FAIL => ID */
+   55,  /*        FOR => ID */
+   55,  /*     IGNORE => ID */
+   55,  /*  INITIALLY => ID */
+   55,  /*    INSTEAD => ID */
+   55,  /*         NO => ID */
+   55,  /*        KEY => ID */
+   55,  /*         OF => ID */
+   55,  /*     OFFSET => ID */
+   55,  /*     PRAGMA => ID */
+   55,  /*      RAISE => ID */
+   55,  /*  RECURSIVE => ID */
+   55,  /*    REPLACE => ID */
+   55,  /*   RESTRICT => ID */
+   55,  /*        ROW => ID */
+   55,  /*    TRIGGER => ID */
+   55,  /*     VACUUM => ID */
+   55,  /*       VIEW => ID */
+   55,  /*    VIRTUAL => ID */
+   55,  /*       WITH => ID */
+   55,  /*    REINDEX => ID */
+   55,  /*     RENAME => ID */
+   55,  /*   CTIME_KW => ID */
 };
 #endif /* YYFALLBACK */
 
@@ -106768,9 +132477,13 @@ static const YYCODETYPE yyFallback[] = {
 **   +  The semantic value stored at this level of the stack.  This is
 **      the information used by the action routines in the grammar.
 **      It is sometimes called the "minor" token.
+**
+** After the "shift" half of a SHIFTREDUCE action, the stateno field
+** actually contains the reduce action for the second half of the
+** SHIFTREDUCE.
 */
 struct yyStackEntry {
-  YYACTIONTYPE stateno;  /* The state-number */
+  YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */
   YYCODETYPE major;      /* The major token value.  This is the code
                          ** number for the token at this stack level */
   YYMINORTYPE minor;     /* The user-supplied minor token value.  This
@@ -106781,15 +132494,18 @@ typedef struct yyStackEntry yyStackEntry;
 /* The state of the parser is completely contained in an instance of
 ** the following structure */
 struct yyParser {
-  int yyidx;                    /* Index of top element in stack */
+  yyStackEntry *yytos;          /* Pointer to top element of the stack */
 #ifdef YYTRACKMAXSTACKDEPTH
-  int yyidxMax;                 /* Maximum value of yyidx */
+  int yyhwm;                    /* High-water mark of the stack */
 #endif
+#ifndef YYNOERRORRECOVERY
   int yyerrcnt;                 /* Shifts left before out of the error */
+#endif
   sqlite3ParserARG_SDECL                /* A place to hold %extra_argument */
 #if YYSTACKDEPTH<=0
   int yystksz;                  /* Current side of the stack */
   yyStackEntry *yystack;        /* The parser's stack */
+  yyStackEntry yystk0;          /* First stack entry */
 #else
   yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */
 #endif
@@ -106838,63 +132554,63 @@ static const char *const yyTokenName[] = {
   "ROLLBACK",      "SAVEPOINT",     "RELEASE",       "TO",          
   "TABLE",         "CREATE",        "IF",            "NOT",         
   "EXISTS",        "TEMP",          "LP",            "RP",          
-  "AS",            "COMMA",         "ID",            "INDEXED",     
-  "ABORT",         "ACTION",        "AFTER",         "ANALYZE",     
-  "ASC",           "ATTACH",        "BEFORE",        "BY",          
-  "CASCADE",       "CAST",          "COLUMNKW",      "CONFLICT",    
-  "DATABASE",      "DESC",          "DETACH",        "EACH",        
-  "FAIL",          "FOR",           "IGNORE",        "INITIALLY",   
-  "INSTEAD",       "LIKE_KW",       "MATCH",         "NO",          
-  "KEY",           "OF",            "OFFSET",        "PRAGMA",      
-  "RAISE",         "REPLACE",       "RESTRICT",      "ROW",         
+  "AS",            "WITHOUT",       "COMMA",         "OR",          
+  "AND",           "IS",            "MATCH",         "LIKE_KW",     
+  "BETWEEN",       "IN",            "ISNULL",        "NOTNULL",     
+  "NE",            "EQ",            "GT",            "LE",          
+  "LT",            "GE",            "ESCAPE",        "BITAND",      
+  "BITOR",         "LSHIFT",        "RSHIFT",        "PLUS",        
+  "MINUS",         "STAR",          "SLASH",         "REM",         
+  "CONCAT",        "COLLATE",       "BITNOT",        "ID",          
+  "INDEXED",       "ABORT",         "ACTION",        "AFTER",       
+  "ANALYZE",       "ASC",           "ATTACH",        "BEFORE",      
+  "BY",            "CASCADE",       "CAST",          "COLUMNKW",    
+  "CONFLICT",      "DATABASE",      "DESC",          "DETACH",      
+  "EACH",          "FAIL",          "FOR",           "IGNORE",      
+  "INITIALLY",     "INSTEAD",       "NO",            "KEY",         
+  "OF",            "OFFSET",        "PRAGMA",        "RAISE",       
+  "RECURSIVE",     "REPLACE",       "RESTRICT",      "ROW",         
   "TRIGGER",       "VACUUM",        "VIEW",          "VIRTUAL",     
-  "REINDEX",       "RENAME",        "CTIME_KW",      "ANY",         
-  "OR",            "AND",           "IS",            "BETWEEN",     
-  "IN",            "ISNULL",        "NOTNULL",       "NE",          
-  "EQ",            "GT",            "LE",            "LT",          
-  "GE",            "ESCAPE",        "BITAND",        "BITOR",       
-  "LSHIFT",        "RSHIFT",        "PLUS",          "MINUS",       
-  "STAR",          "SLASH",         "REM",           "CONCAT",      
-  "COLLATE",       "BITNOT",        "STRING",        "JOIN_KW",     
-  "CONSTRAINT",    "DEFAULT",       "NULL",          "PRIMARY",     
-  "UNIQUE",        "CHECK",         "REFERENCES",    "AUTOINCR",    
-  "ON",            "INSERT",        "DELETE",        "UPDATE",      
-  "SET",           "DEFERRABLE",    "FOREIGN",       "DROP",        
-  "UNION",         "ALL",           "EXCEPT",        "INTERSECT",   
-  "SELECT",        "DISTINCT",      "DOT",           "FROM",        
+  "WITH",          "REINDEX",       "RENAME",        "CTIME_KW",    
+  "ANY",           "STRING",        "JOIN_KW",       "CONSTRAINT",  
+  "DEFAULT",       "NULL",          "PRIMARY",       "UNIQUE",      
+  "CHECK",         "REFERENCES",    "AUTOINCR",      "ON",          
+  "INSERT",        "DELETE",        "UPDATE",        "SET",         
+  "DEFERRABLE",    "FOREIGN",       "DROP",          "UNION",       
+  "ALL",           "EXCEPT",        "INTERSECT",     "SELECT",      
+  "VALUES",        "DISTINCT",      "DOT",           "FROM",        
   "JOIN",          "USING",         "ORDER",         "GROUP",       
   "HAVING",        "LIMIT",         "WHERE",         "INTO",        
-  "VALUES",        "INTEGER",       "FLOAT",         "BLOB",        
-  "REGISTER",      "VARIABLE",      "CASE",          "WHEN",        
-  "THEN",          "ELSE",          "INDEX",         "ALTER",       
-  "ADD",           "error",         "input",         "cmdlist",     
-  "ecmd",          "explain",       "cmdx",          "cmd",         
-  "transtype",     "trans_opt",     "nm",            "savepoint_opt",
-  "create_table",  "create_table_args",  "createkw",      "temp",        
-  "ifnotexists",   "dbnm",          "columnlist",    "conslist_opt",
-  "select",        "column",        "columnid",      "type",        
-  "carglist",      "id",            "ids",           "typetoken",   
-  "typename",      "signed",        "plus_num",      "minus_num",   
-  "carg",          "ccons",         "term",          "expr",        
-  "onconf",        "sortorder",     "autoinc",       "idxlist_opt", 
-  "refargs",       "defer_subclause",  "refarg",        "refact",      
-  "init_deferred_pred_opt",  "conslist",      "tcons",         "idxlist",     
+  "INTEGER",       "FLOAT",         "BLOB",          "VARIABLE",    
+  "CASE",          "WHEN",          "THEN",          "ELSE",        
+  "INDEX",         "ALTER",         "ADD",           "error",       
+  "input",         "cmdlist",       "ecmd",          "explain",     
+  "cmdx",          "cmd",           "transtype",     "trans_opt",   
+  "nm",            "savepoint_opt",  "create_table",  "create_table_args",
+  "createkw",      "temp",          "ifnotexists",   "dbnm",        
+  "columnlist",    "conslist_opt",  "table_options",  "select",      
+  "columnname",    "carglist",      "typetoken",     "typename",    
+  "signed",        "plus_num",      "minus_num",     "ccons",       
+  "term",          "expr",          "onconf",        "sortorder",   
+  "autoinc",       "eidlist_opt",   "refargs",       "defer_subclause",
+  "refarg",        "refact",        "init_deferred_pred_opt",  "conslist",    
+  "tconscomma",    "tcons",         "sortlist",      "eidlist",     
   "defer_subclause_opt",  "orconf",        "resolvetype",   "raisetype",   
-  "ifexists",      "fullname",      "oneselect",     "multiselect_op",
-  "distinct",      "selcollist",    "from",          "where_opt",   
-  "groupby_opt",   "having_opt",    "orderby_opt",   "limit_opt",   
-  "sclp",          "as",            "seltablist",    "stl_prefix",  
-  "joinop",        "indexed_opt",   "on_opt",        "using_opt",   
-  "joinop2",       "inscollist",    "sortlist",      "sortitem",    
-  "nexprlist",     "setlist",       "insert_cmd",    "inscollist_opt",
-  "itemlist",      "exprlist",      "likeop",        "between_op",  
-  "in_op",         "case_operand",  "case_exprlist",  "case_else",   
-  "uniqueflag",    "collate",       "nmnum",         "plus_opt",    
-  "number",        "trigger_decl",  "trigger_cmd_list",  "trigger_time",
-  "trigger_event",  "foreach_clause",  "when_clause",   "trigger_cmd", 
-  "trnm",          "tridxby",       "database_kw_opt",  "key_opt",     
-  "add_column_fullname",  "kwcolumn_opt",  "create_vtab",   "vtabarglist", 
-  "vtabarg",       "vtabargtoken",  "lp",            "anylist",     
+  "ifexists",      "fullname",      "selectnowith",  "oneselect",   
+  "with",          "multiselect_op",  "distinct",      "selcollist",  
+  "from",          "where_opt",     "groupby_opt",   "having_opt",  
+  "orderby_opt",   "limit_opt",     "values",        "nexprlist",   
+  "exprlist",      "sclp",          "as",            "seltablist",  
+  "stl_prefix",    "joinop",        "indexed_opt",   "on_opt",      
+  "using_opt",     "idlist",        "setlist",       "insert_cmd",  
+  "idlist_opt",    "likeop",        "between_op",    "in_op",       
+  "paren_exprlist",  "case_operand",  "case_exprlist",  "case_else",   
+  "uniqueflag",    "collate",       "nmnum",         "trigger_decl",
+  "trigger_cmd_list",  "trigger_time",  "trigger_event",  "foreach_clause",
+  "when_clause",   "trigger_cmd",   "trnm",          "tridxby",     
+  "database_kw_opt",  "key_opt",       "add_column_fullname",  "kwcolumn_opt",
+  "create_vtab",   "vtabarglist",   "vtabarg",       "vtabargtoken",
+  "lp",            "anylist",       "wqlist",      
 };
 #endif /* NDEBUG */
 
@@ -106902,362 +132618,380 @@ static const char *const yyTokenName[] = {
 /* For tracing reduce actions, the names of all rules are required.
 */
 static const char *const yyRuleName[] = {
- /*   0 */ "input ::= cmdlist",
- /*   1 */ "cmdlist ::= cmdlist ecmd",
- /*   2 */ "cmdlist ::= ecmd",
- /*   3 */ "ecmd ::= SEMI",
- /*   4 */ "ecmd ::= explain cmdx SEMI",
- /*   5 */ "explain ::=",
- /*   6 */ "explain ::= EXPLAIN",
- /*   7 */ "explain ::= EXPLAIN QUERY PLAN",
- /*   8 */ "cmdx ::= cmd",
- /*   9 */ "cmd ::= BEGIN transtype trans_opt",
- /*  10 */ "trans_opt ::=",
- /*  11 */ "trans_opt ::= TRANSACTION",
- /*  12 */ "trans_opt ::= TRANSACTION nm",
- /*  13 */ "transtype ::=",
- /*  14 */ "transtype ::= DEFERRED",
- /*  15 */ "transtype ::= IMMEDIATE",
- /*  16 */ "transtype ::= EXCLUSIVE",
- /*  17 */ "cmd ::= COMMIT trans_opt",
- /*  18 */ "cmd ::= END trans_opt",
- /*  19 */ "cmd ::= ROLLBACK trans_opt",
- /*  20 */ "savepoint_opt ::= SAVEPOINT",
- /*  21 */ "savepoint_opt ::=",
- /*  22 */ "cmd ::= SAVEPOINT nm",
- /*  23 */ "cmd ::= RELEASE savepoint_opt nm",
- /*  24 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",
- /*  25 */ "cmd ::= create_table create_table_args",
- /*  26 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",
- /*  27 */ "createkw ::= CREATE",
- /*  28 */ "ifnotexists ::=",
- /*  29 */ "ifnotexists ::= IF NOT EXISTS",
- /*  30 */ "temp ::= TEMP",
- /*  31 */ "temp ::=",
- /*  32 */ "create_table_args ::= LP columnlist conslist_opt RP",
- /*  33 */ "create_table_args ::= AS select",
- /*  34 */ "columnlist ::= columnlist COMMA column",
- /*  35 */ "columnlist ::= column",
- /*  36 */ "column ::= columnid type carglist",
- /*  37 */ "columnid ::= nm",
- /*  38 */ "id ::= ID",
- /*  39 */ "id ::= INDEXED",
- /*  40 */ "ids ::= ID|STRING",
- /*  41 */ "nm ::= id",
- /*  42 */ "nm ::= STRING",
- /*  43 */ "nm ::= JOIN_KW",
- /*  44 */ "type ::=",
- /*  45 */ "type ::= typetoken",
- /*  46 */ "typetoken ::= typename",
- /*  47 */ "typetoken ::= typename LP signed RP",
- /*  48 */ "typetoken ::= typename LP signed COMMA signed RP",
- /*  49 */ "typename ::= ids",
- /*  50 */ "typename ::= typename ids",
- /*  51 */ "signed ::= plus_num",
- /*  52 */ "signed ::= minus_num",
- /*  53 */ "carglist ::= carglist carg",
- /*  54 */ "carglist ::=",
- /*  55 */ "carg ::= CONSTRAINT nm ccons",
- /*  56 */ "carg ::= ccons",
- /*  57 */ "ccons ::= DEFAULT term",
- /*  58 */ "ccons ::= DEFAULT LP expr RP",
- /*  59 */ "ccons ::= DEFAULT PLUS term",
- /*  60 */ "ccons ::= DEFAULT MINUS term",
- /*  61 */ "ccons ::= DEFAULT id",
- /*  62 */ "ccons ::= NULL onconf",
- /*  63 */ "ccons ::= NOT NULL onconf",
- /*  64 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",
- /*  65 */ "ccons ::= UNIQUE onconf",
- /*  66 */ "ccons ::= CHECK LP expr RP",
- /*  67 */ "ccons ::= REFERENCES nm idxlist_opt refargs",
- /*  68 */ "ccons ::= defer_subclause",
- /*  69 */ "ccons ::= COLLATE ids",
- /*  70 */ "autoinc ::=",
- /*  71 */ "autoinc ::= AUTOINCR",
- /*  72 */ "refargs ::=",
- /*  73 */ "refargs ::= refargs refarg",
- /*  74 */ "refarg ::= MATCH nm",
- /*  75 */ "refarg ::= ON INSERT refact",
- /*  76 */ "refarg ::= ON DELETE refact",
- /*  77 */ "refarg ::= ON UPDATE refact",
- /*  78 */ "refact ::= SET NULL",
- /*  79 */ "refact ::= SET DEFAULT",
- /*  80 */ "refact ::= CASCADE",
- /*  81 */ "refact ::= RESTRICT",
- /*  82 */ "refact ::= NO ACTION",
- /*  83 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",
- /*  84 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",
- /*  85 */ "init_deferred_pred_opt ::=",
- /*  86 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",
- /*  87 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",
- /*  88 */ "conslist_opt ::=",
- /*  89 */ "conslist_opt ::= COMMA conslist",
- /*  90 */ "conslist ::= conslist COMMA tcons",
- /*  91 */ "conslist ::= conslist tcons",
- /*  92 */ "conslist ::= tcons",
- /*  93 */ "tcons ::= CONSTRAINT nm",
- /*  94 */ "tcons ::= PRIMARY KEY LP idxlist autoinc RP onconf",
- /*  95 */ "tcons ::= UNIQUE LP idxlist RP onconf",
- /*  96 */ "tcons ::= CHECK LP expr RP onconf",
- /*  97 */ "tcons ::= FOREIGN KEY LP idxlist RP REFERENCES nm idxlist_opt refargs defer_subclause_opt",
- /*  98 */ "defer_subclause_opt ::=",
- /*  99 */ "defer_subclause_opt ::= defer_subclause",
- /* 100 */ "onconf ::=",
- /* 101 */ "onconf ::= ON CONFLICT resolvetype",
- /* 102 */ "orconf ::=",
- /* 103 */ "orconf ::= OR resolvetype",
- /* 104 */ "resolvetype ::= raisetype",
- /* 105 */ "resolvetype ::= IGNORE",
- /* 106 */ "resolvetype ::= REPLACE",
- /* 107 */ "cmd ::= DROP TABLE ifexists fullname",
- /* 108 */ "ifexists ::= IF EXISTS",
- /* 109 */ "ifexists ::=",
- /* 110 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm AS select",
- /* 111 */ "cmd ::= DROP VIEW ifexists fullname",
- /* 112 */ "cmd ::= select",
- /* 113 */ "select ::= oneselect",
- /* 114 */ "select ::= select multiselect_op oneselect",
- /* 115 */ "multiselect_op ::= UNION",
- /* 116 */ "multiselect_op ::= UNION ALL",
- /* 117 */ "multiselect_op ::= EXCEPT|INTERSECT",
- /* 118 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",
- /* 119 */ "distinct ::= DISTINCT",
- /* 120 */ "distinct ::= ALL",
- /* 121 */ "distinct ::=",
- /* 122 */ "sclp ::= selcollist COMMA",
- /* 123 */ "sclp ::=",
- /* 124 */ "selcollist ::= sclp expr as",
- /* 125 */ "selcollist ::= sclp STAR",
- /* 126 */ "selcollist ::= sclp nm DOT STAR",
- /* 127 */ "as ::= AS nm",
- /* 128 */ "as ::= ids",
- /* 129 */ "as ::=",
- /* 130 */ "from ::=",
- /* 131 */ "from ::= FROM seltablist",
- /* 132 */ "stl_prefix ::= seltablist joinop",
- /* 133 */ "stl_prefix ::=",
- /* 134 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",
- /* 135 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",
- /* 136 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",
- /* 137 */ "dbnm ::=",
- /* 138 */ "dbnm ::= DOT nm",
- /* 139 */ "fullname ::= nm dbnm",
- /* 140 */ "joinop ::= COMMA|JOIN",
- /* 141 */ "joinop ::= JOIN_KW JOIN",
- /* 142 */ "joinop ::= JOIN_KW nm JOIN",
- /* 143 */ "joinop ::= JOIN_KW nm nm JOIN",
- /* 144 */ "on_opt ::= ON expr",
- /* 145 */ "on_opt ::=",
- /* 146 */ "indexed_opt ::=",
- /* 147 */ "indexed_opt ::= INDEXED BY nm",
- /* 148 */ "indexed_opt ::= NOT INDEXED",
- /* 149 */ "using_opt ::= USING LP inscollist RP",
- /* 150 */ "using_opt ::=",
- /* 151 */ "orderby_opt ::=",
- /* 152 */ "orderby_opt ::= ORDER BY sortlist",
- /* 153 */ "sortlist ::= sortlist COMMA sortitem sortorder",
- /* 154 */ "sortlist ::= sortitem sortorder",
- /* 155 */ "sortitem ::= expr",
- /* 156 */ "sortorder ::= ASC",
- /* 157 */ "sortorder ::= DESC",
- /* 158 */ "sortorder ::=",
- /* 159 */ "groupby_opt ::=",
- /* 160 */ "groupby_opt ::= GROUP BY nexprlist",
- /* 161 */ "having_opt ::=",
- /* 162 */ "having_opt ::= HAVING expr",
- /* 163 */ "limit_opt ::=",
- /* 164 */ "limit_opt ::= LIMIT expr",
- /* 165 */ "limit_opt ::= LIMIT expr OFFSET expr",
- /* 166 */ "limit_opt ::= LIMIT expr COMMA expr",
- /* 167 */ "cmd ::= DELETE FROM fullname indexed_opt where_opt",
- /* 168 */ "where_opt ::=",
- /* 169 */ "where_opt ::= WHERE expr",
- /* 170 */ "cmd ::= UPDATE orconf fullname indexed_opt SET setlist where_opt",
- /* 171 */ "setlist ::= setlist COMMA nm EQ expr",
- /* 172 */ "setlist ::= nm EQ expr",
- /* 173 */ "cmd ::= insert_cmd INTO fullname inscollist_opt VALUES LP itemlist RP",
- /* 174 */ "cmd ::= insert_cmd INTO fullname inscollist_opt select",
- /* 175 */ "cmd ::= insert_cmd INTO fullname inscollist_opt DEFAULT VALUES",
- /* 176 */ "insert_cmd ::= INSERT orconf",
- /* 177 */ "insert_cmd ::= REPLACE",
- /* 178 */ "itemlist ::= itemlist COMMA expr",
- /* 179 */ "itemlist ::= expr",
- /* 180 */ "inscollist_opt ::=",
- /* 181 */ "inscollist_opt ::= LP inscollist RP",
- /* 182 */ "inscollist ::= inscollist COMMA nm",
- /* 183 */ "inscollist ::= nm",
- /* 184 */ "expr ::= term",
- /* 185 */ "expr ::= LP expr RP",
- /* 186 */ "term ::= NULL",
- /* 187 */ "expr ::= id",
- /* 188 */ "expr ::= JOIN_KW",
- /* 189 */ "expr ::= nm DOT nm",
- /* 190 */ "expr ::= nm DOT nm DOT nm",
- /* 191 */ "term ::= INTEGER|FLOAT|BLOB",
- /* 192 */ "term ::= STRING",
- /* 193 */ "expr ::= REGISTER",
- /* 194 */ "expr ::= VARIABLE",
- /* 195 */ "expr ::= expr COLLATE ids",
- /* 196 */ "expr ::= CAST LP expr AS typetoken RP",
- /* 197 */ "expr ::= ID LP distinct exprlist RP",
- /* 198 */ "expr ::= ID LP STAR RP",
- /* 199 */ "term ::= CTIME_KW",
- /* 200 */ "expr ::= expr AND expr",
- /* 201 */ "expr ::= expr OR expr",
- /* 202 */ "expr ::= expr LT|GT|GE|LE expr",
- /* 203 */ "expr ::= expr EQ|NE expr",
- /* 204 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",
- /* 205 */ "expr ::= expr PLUS|MINUS expr",
- /* 206 */ "expr ::= expr STAR|SLASH|REM expr",
- /* 207 */ "expr ::= expr CONCAT expr",
- /* 208 */ "likeop ::= LIKE_KW",
- /* 209 */ "likeop ::= NOT LIKE_KW",
- /* 210 */ "likeop ::= MATCH",
- /* 211 */ "likeop ::= NOT MATCH",
- /* 212 */ "expr ::= expr likeop expr",
- /* 213 */ "expr ::= expr likeop expr ESCAPE expr",
- /* 214 */ "expr ::= expr ISNULL|NOTNULL",
- /* 215 */ "expr ::= expr NOT NULL",
- /* 216 */ "expr ::= expr IS expr",
- /* 217 */ "expr ::= expr IS NOT expr",
- /* 218 */ "expr ::= NOT expr",
- /* 219 */ "expr ::= BITNOT expr",
- /* 220 */ "expr ::= MINUS expr",
- /* 221 */ "expr ::= PLUS expr",
- /* 222 */ "between_op ::= BETWEEN",
- /* 223 */ "between_op ::= NOT BETWEEN",
- /* 224 */ "expr ::= expr between_op expr AND expr",
- /* 225 */ "in_op ::= IN",
- /* 226 */ "in_op ::= NOT IN",
- /* 227 */ "expr ::= expr in_op LP exprlist RP",
- /* 228 */ "expr ::= LP select RP",
- /* 229 */ "expr ::= expr in_op LP select RP",
- /* 230 */ "expr ::= expr in_op nm dbnm",
- /* 231 */ "expr ::= EXISTS LP select RP",
- /* 232 */ "expr ::= CASE case_operand case_exprlist case_else END",
- /* 233 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",
- /* 234 */ "case_exprlist ::= WHEN expr THEN expr",
- /* 235 */ "case_else ::= ELSE expr",
- /* 236 */ "case_else ::=",
- /* 237 */ "case_operand ::= expr",
- /* 238 */ "case_operand ::=",
- /* 239 */ "exprlist ::= nexprlist",
- /* 240 */ "exprlist ::=",
- /* 241 */ "nexprlist ::= nexprlist COMMA expr",
- /* 242 */ "nexprlist ::= expr",
- /* 243 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP idxlist RP",
- /* 244 */ "uniqueflag ::= UNIQUE",
- /* 245 */ "uniqueflag ::=",
- /* 246 */ "idxlist_opt ::=",
- /* 247 */ "idxlist_opt ::= LP idxlist RP",
- /* 248 */ "idxlist ::= idxlist COMMA nm collate sortorder",
- /* 249 */ "idxlist ::= nm collate sortorder",
- /* 250 */ "collate ::=",
- /* 251 */ "collate ::= COLLATE ids",
- /* 252 */ "cmd ::= DROP INDEX ifexists fullname",
- /* 253 */ "cmd ::= VACUUM",
- /* 254 */ "cmd ::= VACUUM nm",
- /* 255 */ "cmd ::= PRAGMA nm dbnm",
- /* 256 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",
- /* 257 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",
- /* 258 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",
- /* 259 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",
- /* 260 */ "nmnum ::= plus_num",
- /* 261 */ "nmnum ::= nm",
- /* 262 */ "nmnum ::= ON",
- /* 263 */ "nmnum ::= DELETE",
- /* 264 */ "nmnum ::= DEFAULT",
- /* 265 */ "plus_num ::= plus_opt number",
- /* 266 */ "minus_num ::= MINUS number",
- /* 267 */ "number ::= INTEGER|FLOAT",
- /* 268 */ "plus_opt ::= PLUS",
- /* 269 */ "plus_opt ::=",
- /* 270 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",
- /* 271 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",
- /* 272 */ "trigger_time ::= BEFORE",
- /* 273 */ "trigger_time ::= AFTER",
- /* 274 */ "trigger_time ::= INSTEAD OF",
- /* 275 */ "trigger_time ::=",
- /* 276 */ "trigger_event ::= DELETE|INSERT",
- /* 277 */ "trigger_event ::= UPDATE",
- /* 278 */ "trigger_event ::= UPDATE OF inscollist",
- /* 279 */ "foreach_clause ::=",
- /* 280 */ "foreach_clause ::= FOR EACH ROW",
- /* 281 */ "when_clause ::=",
- /* 282 */ "when_clause ::= WHEN expr",
- /* 283 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",
- /* 284 */ "trigger_cmd_list ::= trigger_cmd SEMI",
- /* 285 */ "trnm ::= nm",
- /* 286 */ "trnm ::= nm DOT nm",
- /* 287 */ "tridxby ::=",
- /* 288 */ "tridxby ::= INDEXED BY nm",
- /* 289 */ "tridxby ::= NOT INDEXED",
- /* 290 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt",
- /* 291 */ "trigger_cmd ::= insert_cmd INTO trnm inscollist_opt VALUES LP itemlist RP",
- /* 292 */ "trigger_cmd ::= insert_cmd INTO trnm inscollist_opt select",
- /* 293 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt",
- /* 294 */ "trigger_cmd ::= select",
- /* 295 */ "expr ::= RAISE LP IGNORE RP",
- /* 296 */ "expr ::= RAISE LP raisetype COMMA nm RP",
- /* 297 */ "raisetype ::= ROLLBACK",
- /* 298 */ "raisetype ::= ABORT",
- /* 299 */ "raisetype ::= FAIL",
- /* 300 */ "cmd ::= DROP TRIGGER ifexists fullname",
- /* 301 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",
- /* 302 */ "cmd ::= DETACH database_kw_opt expr",
- /* 303 */ "key_opt ::=",
- /* 304 */ "key_opt ::= KEY expr",
- /* 305 */ "database_kw_opt ::= DATABASE",
- /* 306 */ "database_kw_opt ::=",
- /* 307 */ "cmd ::= REINDEX",
- /* 308 */ "cmd ::= REINDEX nm dbnm",
- /* 309 */ "cmd ::= ANALYZE",
- /* 310 */ "cmd ::= ANALYZE nm dbnm",
- /* 311 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",
- /* 312 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column",
- /* 313 */ "add_column_fullname ::= fullname",
- /* 314 */ "kwcolumn_opt ::=",
- /* 315 */ "kwcolumn_opt ::= COLUMNKW",
- /* 316 */ "cmd ::= create_vtab",
- /* 317 */ "cmd ::= create_vtab LP vtabarglist RP",
- /* 318 */ "create_vtab ::= createkw VIRTUAL TABLE nm dbnm USING nm",
- /* 319 */ "vtabarglist ::= vtabarg",
- /* 320 */ "vtabarglist ::= vtabarglist COMMA vtabarg",
- /* 321 */ "vtabarg ::=",
- /* 322 */ "vtabarg ::= vtabarg vtabargtoken",
- /* 323 */ "vtabargtoken ::= ANY",
- /* 324 */ "vtabargtoken ::= lp anylist RP",
- /* 325 */ "lp ::= LP",
- /* 326 */ "anylist ::=",
- /* 327 */ "anylist ::= anylist LP anylist RP",
- /* 328 */ "anylist ::= anylist ANY",
+ /*   0 */ "explain ::= EXPLAIN",
+ /*   1 */ "explain ::= EXPLAIN QUERY PLAN",
+ /*   2 */ "cmdx ::= cmd",
+ /*   3 */ "cmd ::= BEGIN transtype trans_opt",
+ /*   4 */ "transtype ::=",
+ /*   5 */ "transtype ::= DEFERRED",
+ /*   6 */ "transtype ::= IMMEDIATE",
+ /*   7 */ "transtype ::= EXCLUSIVE",
+ /*   8 */ "cmd ::= COMMIT trans_opt",
+ /*   9 */ "cmd ::= END trans_opt",
+ /*  10 */ "cmd ::= ROLLBACK trans_opt",
+ /*  11 */ "cmd ::= SAVEPOINT nm",
+ /*  12 */ "cmd ::= RELEASE savepoint_opt nm",
+ /*  13 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",
+ /*  14 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",
+ /*  15 */ "createkw ::= CREATE",
+ /*  16 */ "ifnotexists ::=",
+ /*  17 */ "ifnotexists ::= IF NOT EXISTS",
+ /*  18 */ "temp ::= TEMP",
+ /*  19 */ "temp ::=",
+ /*  20 */ "create_table_args ::= LP columnlist conslist_opt RP table_options",
+ /*  21 */ "create_table_args ::= AS select",
+ /*  22 */ "table_options ::=",
+ /*  23 */ "table_options ::= WITHOUT nm",
+ /*  24 */ "columnname ::= nm typetoken",
+ /*  25 */ "typetoken ::=",
+ /*  26 */ "typetoken ::= typename LP signed RP",
+ /*  27 */ "typetoken ::= typename LP signed COMMA signed RP",
+ /*  28 */ "typename ::= typename ID|STRING",
+ /*  29 */ "ccons ::= CONSTRAINT nm",
+ /*  30 */ "ccons ::= DEFAULT term",
+ /*  31 */ "ccons ::= DEFAULT LP expr RP",
+ /*  32 */ "ccons ::= DEFAULT PLUS term",
+ /*  33 */ "ccons ::= DEFAULT MINUS term",
+ /*  34 */ "ccons ::= DEFAULT ID|INDEXED",
+ /*  35 */ "ccons ::= NOT NULL onconf",
+ /*  36 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",
+ /*  37 */ "ccons ::= UNIQUE onconf",
+ /*  38 */ "ccons ::= CHECK LP expr RP",
+ /*  39 */ "ccons ::= REFERENCES nm eidlist_opt refargs",
+ /*  40 */ "ccons ::= defer_subclause",
+ /*  41 */ "ccons ::= COLLATE ID|STRING",
+ /*  42 */ "autoinc ::=",
+ /*  43 */ "autoinc ::= AUTOINCR",
+ /*  44 */ "refargs ::=",
+ /*  45 */ "refargs ::= refargs refarg",
+ /*  46 */ "refarg ::= MATCH nm",
+ /*  47 */ "refarg ::= ON INSERT refact",
+ /*  48 */ "refarg ::= ON DELETE refact",
+ /*  49 */ "refarg ::= ON UPDATE refact",
+ /*  50 */ "refact ::= SET NULL",
+ /*  51 */ "refact ::= SET DEFAULT",
+ /*  52 */ "refact ::= CASCADE",
+ /*  53 */ "refact ::= RESTRICT",
+ /*  54 */ "refact ::= NO ACTION",
+ /*  55 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",
+ /*  56 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",
+ /*  57 */ "init_deferred_pred_opt ::=",
+ /*  58 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",
+ /*  59 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",
+ /*  60 */ "conslist_opt ::=",
+ /*  61 */ "tconscomma ::= COMMA",
+ /*  62 */ "tcons ::= CONSTRAINT nm",
+ /*  63 */ "tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf",
+ /*  64 */ "tcons ::= UNIQUE LP sortlist RP onconf",
+ /*  65 */ "tcons ::= CHECK LP expr RP onconf",
+ /*  66 */ "tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt",
+ /*  67 */ "defer_subclause_opt ::=",
+ /*  68 */ "onconf ::=",
+ /*  69 */ "onconf ::= ON CONFLICT resolvetype",
+ /*  70 */ "orconf ::=",
+ /*  71 */ "orconf ::= OR resolvetype",
+ /*  72 */ "resolvetype ::= IGNORE",
+ /*  73 */ "resolvetype ::= REPLACE",
+ /*  74 */ "cmd ::= DROP TABLE ifexists fullname",
+ /*  75 */ "ifexists ::= IF EXISTS",
+ /*  76 */ "ifexists ::=",
+ /*  77 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select",
+ /*  78 */ "cmd ::= DROP VIEW ifexists fullname",
+ /*  79 */ "cmd ::= select",
+ /*  80 */ "select ::= with selectnowith",
+ /*  81 */ "selectnowith ::= selectnowith multiselect_op oneselect",
+ /*  82 */ "multiselect_op ::= UNION",
+ /*  83 */ "multiselect_op ::= UNION ALL",
+ /*  84 */ "multiselect_op ::= EXCEPT|INTERSECT",
+ /*  85 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",
+ /*  86 */ "values ::= VALUES LP nexprlist RP",
+ /*  87 */ "values ::= values COMMA LP exprlist RP",
+ /*  88 */ "distinct ::= DISTINCT",
+ /*  89 */ "distinct ::= ALL",
+ /*  90 */ "distinct ::=",
+ /*  91 */ "sclp ::=",
+ /*  92 */ "selcollist ::= sclp expr as",
+ /*  93 */ "selcollist ::= sclp STAR",
+ /*  94 */ "selcollist ::= sclp nm DOT STAR",
+ /*  95 */ "as ::= AS nm",
+ /*  96 */ "as ::=",
+ /*  97 */ "from ::=",
+ /*  98 */ "from ::= FROM seltablist",
+ /*  99 */ "stl_prefix ::= seltablist joinop",
+ /* 100 */ "stl_prefix ::=",
+ /* 101 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",
+ /* 102 */ "seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt",
+ /* 103 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",
+ /* 104 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",
+ /* 105 */ "dbnm ::=",
+ /* 106 */ "dbnm ::= DOT nm",
+ /* 107 */ "fullname ::= nm dbnm",
+ /* 108 */ "joinop ::= COMMA|JOIN",
+ /* 109 */ "joinop ::= JOIN_KW JOIN",
+ /* 110 */ "joinop ::= JOIN_KW nm JOIN",
+ /* 111 */ "joinop ::= JOIN_KW nm nm JOIN",
+ /* 112 */ "on_opt ::= ON expr",
+ /* 113 */ "on_opt ::=",
+ /* 114 */ "indexed_opt ::=",
+ /* 115 */ "indexed_opt ::= INDEXED BY nm",
+ /* 116 */ "indexed_opt ::= NOT INDEXED",
+ /* 117 */ "using_opt ::= USING LP idlist RP",
+ /* 118 */ "using_opt ::=",
+ /* 119 */ "orderby_opt ::=",
+ /* 120 */ "orderby_opt ::= ORDER BY sortlist",
+ /* 121 */ "sortlist ::= sortlist COMMA expr sortorder",
+ /* 122 */ "sortlist ::= expr sortorder",
+ /* 123 */ "sortorder ::= ASC",
+ /* 124 */ "sortorder ::= DESC",
+ /* 125 */ "sortorder ::=",
+ /* 126 */ "groupby_opt ::=",
+ /* 127 */ "groupby_opt ::= GROUP BY nexprlist",
+ /* 128 */ "having_opt ::=",
+ /* 129 */ "having_opt ::= HAVING expr",
+ /* 130 */ "limit_opt ::=",
+ /* 131 */ "limit_opt ::= LIMIT expr",
+ /* 132 */ "limit_opt ::= LIMIT expr OFFSET expr",
+ /* 133 */ "limit_opt ::= LIMIT expr COMMA expr",
+ /* 134 */ "cmd ::= with DELETE FROM fullname indexed_opt where_opt",
+ /* 135 */ "where_opt ::=",
+ /* 136 */ "where_opt ::= WHERE expr",
+ /* 137 */ "cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt",
+ /* 138 */ "setlist ::= setlist COMMA nm EQ expr",
+ /* 139 */ "setlist ::= nm EQ expr",
+ /* 140 */ "cmd ::= with insert_cmd INTO fullname idlist_opt select",
+ /* 141 */ "cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES",
+ /* 142 */ "insert_cmd ::= INSERT orconf",
+ /* 143 */ "insert_cmd ::= REPLACE",
+ /* 144 */ "idlist_opt ::=",
+ /* 145 */ "idlist_opt ::= LP idlist RP",
+ /* 146 */ "idlist ::= idlist COMMA nm",
+ /* 147 */ "idlist ::= nm",
+ /* 148 */ "expr ::= LP expr RP",
+ /* 149 */ "term ::= NULL",
+ /* 150 */ "expr ::= ID|INDEXED",
+ /* 151 */ "expr ::= JOIN_KW",
+ /* 152 */ "expr ::= nm DOT nm",
+ /* 153 */ "expr ::= nm DOT nm DOT nm",
+ /* 154 */ "term ::= INTEGER|FLOAT|BLOB",
+ /* 155 */ "term ::= STRING",
+ /* 156 */ "expr ::= VARIABLE",
+ /* 157 */ "expr ::= expr COLLATE ID|STRING",
+ /* 158 */ "expr ::= CAST LP expr AS typetoken RP",
+ /* 159 */ "expr ::= ID|INDEXED LP distinct exprlist RP",
+ /* 160 */ "expr ::= ID|INDEXED LP STAR RP",
+ /* 161 */ "term ::= CTIME_KW",
+ /* 162 */ "expr ::= expr AND expr",
+ /* 163 */ "expr ::= expr OR expr",
+ /* 164 */ "expr ::= expr LT|GT|GE|LE expr",
+ /* 165 */ "expr ::= expr EQ|NE expr",
+ /* 166 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",
+ /* 167 */ "expr ::= expr PLUS|MINUS expr",
+ /* 168 */ "expr ::= expr STAR|SLASH|REM expr",
+ /* 169 */ "expr ::= expr CONCAT expr",
+ /* 170 */ "likeop ::= LIKE_KW|MATCH",
+ /* 171 */ "likeop ::= NOT LIKE_KW|MATCH",
+ /* 172 */ "expr ::= expr likeop expr",
+ /* 173 */ "expr ::= expr likeop expr ESCAPE expr",
+ /* 174 */ "expr ::= expr ISNULL|NOTNULL",
+ /* 175 */ "expr ::= expr NOT NULL",
+ /* 176 */ "expr ::= expr IS expr",
+ /* 177 */ "expr ::= expr IS NOT expr",
+ /* 178 */ "expr ::= NOT expr",
+ /* 179 */ "expr ::= BITNOT expr",
+ /* 180 */ "expr ::= MINUS expr",
+ /* 181 */ "expr ::= PLUS expr",
+ /* 182 */ "between_op ::= BETWEEN",
+ /* 183 */ "between_op ::= NOT BETWEEN",
+ /* 184 */ "expr ::= expr between_op expr AND expr",
+ /* 185 */ "in_op ::= IN",
+ /* 186 */ "in_op ::= NOT IN",
+ /* 187 */ "expr ::= expr in_op LP exprlist RP",
+ /* 188 */ "expr ::= LP select RP",
+ /* 189 */ "expr ::= expr in_op LP select RP",
+ /* 190 */ "expr ::= expr in_op nm dbnm paren_exprlist",
+ /* 191 */ "expr ::= EXISTS LP select RP",
+ /* 192 */ "expr ::= CASE case_operand case_exprlist case_else END",
+ /* 193 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",
+ /* 194 */ "case_exprlist ::= WHEN expr THEN expr",
+ /* 195 */ "case_else ::= ELSE expr",
+ /* 196 */ "case_else ::=",
+ /* 197 */ "case_operand ::= expr",
+ /* 198 */ "case_operand ::=",
+ /* 199 */ "exprlist ::=",
+ /* 200 */ "nexprlist ::= nexprlist COMMA expr",
+ /* 201 */ "nexprlist ::= expr",
+ /* 202 */ "paren_exprlist ::=",
+ /* 203 */ "paren_exprlist ::= LP exprlist RP",
+ /* 204 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt",
+ /* 205 */ "uniqueflag ::= UNIQUE",
+ /* 206 */ "uniqueflag ::=",
+ /* 207 */ "eidlist_opt ::=",
+ /* 208 */ "eidlist_opt ::= LP eidlist RP",
+ /* 209 */ "eidlist ::= eidlist COMMA nm collate sortorder",
+ /* 210 */ "eidlist ::= nm collate sortorder",
+ /* 211 */ "collate ::=",
+ /* 212 */ "collate ::= COLLATE ID|STRING",
+ /* 213 */ "cmd ::= DROP INDEX ifexists fullname",
+ /* 214 */ "cmd ::= VACUUM",
+ /* 215 */ "cmd ::= VACUUM nm",
+ /* 216 */ "cmd ::= PRAGMA nm dbnm",
+ /* 217 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",
+ /* 218 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",
+ /* 219 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",
+ /* 220 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",
+ /* 221 */ "plus_num ::= PLUS INTEGER|FLOAT",
+ /* 222 */ "minus_num ::= MINUS INTEGER|FLOAT",
+ /* 223 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",
+ /* 224 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",
+ /* 225 */ "trigger_time ::= BEFORE",
+ /* 226 */ "trigger_time ::= AFTER",
+ /* 227 */ "trigger_time ::= INSTEAD OF",
+ /* 228 */ "trigger_time ::=",
+ /* 229 */ "trigger_event ::= DELETE|INSERT",
+ /* 230 */ "trigger_event ::= UPDATE",
+ /* 231 */ "trigger_event ::= UPDATE OF idlist",
+ /* 232 */ "when_clause ::=",
+ /* 233 */ "when_clause ::= WHEN expr",
+ /* 234 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",
+ /* 235 */ "trigger_cmd_list ::= trigger_cmd SEMI",
+ /* 236 */ "trnm ::= nm DOT nm",
+ /* 237 */ "tridxby ::= INDEXED BY nm",
+ /* 238 */ "tridxby ::= NOT INDEXED",
+ /* 239 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt",
+ /* 240 */ "trigger_cmd ::= insert_cmd INTO trnm idlist_opt select",
+ /* 241 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt",
+ /* 242 */ "trigger_cmd ::= select",
+ /* 243 */ "expr ::= RAISE LP IGNORE RP",
+ /* 244 */ "expr ::= RAISE LP raisetype COMMA nm RP",
+ /* 245 */ "raisetype ::= ROLLBACK",
+ /* 246 */ "raisetype ::= ABORT",
+ /* 247 */ "raisetype ::= FAIL",
+ /* 248 */ "cmd ::= DROP TRIGGER ifexists fullname",
+ /* 249 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",
+ /* 250 */ "cmd ::= DETACH database_kw_opt expr",
+ /* 251 */ "key_opt ::=",
+ /* 252 */ "key_opt ::= KEY expr",
+ /* 253 */ "cmd ::= REINDEX",
+ /* 254 */ "cmd ::= REINDEX nm dbnm",
+ /* 255 */ "cmd ::= ANALYZE",
+ /* 256 */ "cmd ::= ANALYZE nm dbnm",
+ /* 257 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",
+ /* 258 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist",
+ /* 259 */ "add_column_fullname ::= fullname",
+ /* 260 */ "cmd ::= create_vtab",
+ /* 261 */ "cmd ::= create_vtab LP vtabarglist RP",
+ /* 262 */ "create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm",
+ /* 263 */ "vtabarg ::=",
+ /* 264 */ "vtabargtoken ::= ANY",
+ /* 265 */ "vtabargtoken ::= lp anylist RP",
+ /* 266 */ "lp ::= LP",
+ /* 267 */ "with ::=",
+ /* 268 */ "with ::= WITH wqlist",
+ /* 269 */ "with ::= WITH RECURSIVE wqlist",
+ /* 270 */ "wqlist ::= nm eidlist_opt AS LP select RP",
+ /* 271 */ "wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP",
+ /* 272 */ "input ::= cmdlist",
+ /* 273 */ "cmdlist ::= cmdlist ecmd",
+ /* 274 */ "cmdlist ::= ecmd",
+ /* 275 */ "ecmd ::= SEMI",
+ /* 276 */ "ecmd ::= explain cmdx SEMI",
+ /* 277 */ "explain ::=",
+ /* 278 */ "trans_opt ::=",
+ /* 279 */ "trans_opt ::= TRANSACTION",
+ /* 280 */ "trans_opt ::= TRANSACTION nm",
+ /* 281 */ "savepoint_opt ::= SAVEPOINT",
+ /* 282 */ "savepoint_opt ::=",
+ /* 283 */ "cmd ::= create_table create_table_args",
+ /* 284 */ "columnlist ::= columnlist COMMA columnname carglist",
+ /* 285 */ "columnlist ::= columnname carglist",
+ /* 286 */ "nm ::= ID|INDEXED",
+ /* 287 */ "nm ::= STRING",
+ /* 288 */ "nm ::= JOIN_KW",
+ /* 289 */ "typetoken ::= typename",
+ /* 290 */ "typename ::= ID|STRING",
+ /* 291 */ "signed ::= plus_num",
+ /* 292 */ "signed ::= minus_num",
+ /* 293 */ "carglist ::= carglist ccons",
+ /* 294 */ "carglist ::=",
+ /* 295 */ "ccons ::= NULL onconf",
+ /* 296 */ "conslist_opt ::= COMMA conslist",
+ /* 297 */ "conslist ::= conslist tconscomma tcons",
+ /* 298 */ "conslist ::= tcons",
+ /* 299 */ "tconscomma ::=",
+ /* 300 */ "defer_subclause_opt ::= defer_subclause",
+ /* 301 */ "resolvetype ::= raisetype",
+ /* 302 */ "selectnowith ::= oneselect",
+ /* 303 */ "oneselect ::= values",
+ /* 304 */ "sclp ::= selcollist COMMA",
+ /* 305 */ "as ::= ID|STRING",
+ /* 306 */ "expr ::= term",
+ /* 307 */ "exprlist ::= nexprlist",
+ /* 308 */ "nmnum ::= plus_num",
+ /* 309 */ "nmnum ::= nm",
+ /* 310 */ "nmnum ::= ON",
+ /* 311 */ "nmnum ::= DELETE",
+ /* 312 */ "nmnum ::= DEFAULT",
+ /* 313 */ "plus_num ::= INTEGER|FLOAT",
+ /* 314 */ "foreach_clause ::=",
+ /* 315 */ "foreach_clause ::= FOR EACH ROW",
+ /* 316 */ "trnm ::= nm",
+ /* 317 */ "tridxby ::=",
+ /* 318 */ "database_kw_opt ::= DATABASE",
+ /* 319 */ "database_kw_opt ::=",
+ /* 320 */ "kwcolumn_opt ::=",
+ /* 321 */ "kwcolumn_opt ::= COLUMNKW",
+ /* 322 */ "vtabarglist ::= vtabarg",
+ /* 323 */ "vtabarglist ::= vtabarglist COMMA vtabarg",
+ /* 324 */ "vtabarg ::= vtabarg vtabargtoken",
+ /* 325 */ "anylist ::=",
+ /* 326 */ "anylist ::= anylist LP anylist RP",
+ /* 327 */ "anylist ::= anylist ANY",
 };
 #endif /* NDEBUG */
 
 
 #if YYSTACKDEPTH<=0
 /*
-** Try to increase the size of the parser stack.
+** Try to increase the size of the parser stack.  Return the number
+** of errors.  Return 0 on success.
 */
-static void yyGrowStack(yyParser *p){
+static int yyGrowStack(yyParser *p){
   int newSize;
+  int idx;
   yyStackEntry *pNew;
 
   newSize = p->yystksz*2 + 100;
-  pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));
+  idx = p->yytos ? (int)(p->yytos - p->yystack) : 0;
+  if( p->yystack==&p->yystk0 ){
+    pNew = malloc(newSize*sizeof(pNew[0]));
+    if( pNew ) pNew[0] = p->yystk0;
+  }else{
+    pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));
+  }
   if( pNew ){
     p->yystack = pNew;
-    p->yystksz = newSize;
+    p->yytos = &p->yystack[idx];
 #ifndef NDEBUG
     if( yyTraceFILE ){
-      fprintf(yyTraceFILE,"%sStack grows to %d entries!\n",
-              yyTracePrompt, p->yystksz);
+      fprintf(yyTraceFILE,"%sStack grows from %d to %d entries.\n",
+              yyTracePrompt, p->yystksz, newSize);
     }
 #endif
+    p->yystksz = newSize;
   }
+  return pNew==0; 
 }
 #endif
 
+/* Datatype of the argument to the memory allocated passed as the
+** second argument to sqlite3ParserAlloc() below.  This can be changed by
+** putting an appropriate #define in the %include section of the input
+** grammar.
+*/
+#ifndef YYMALLOCARGTYPE
+# define YYMALLOCARGTYPE size_t
+#endif
+
 /* 
 ** This function allocates a new parser.
 ** The only argument is a pointer to a function which works like
@@ -107270,27 +133004,38 @@ static void yyGrowStack(yyParser *p){
 ** A pointer to a parser.  This pointer is used in subsequent calls
 ** to sqlite3Parser and sqlite3ParserFree.
 */
-SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(size_t)){
+SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(YYMALLOCARGTYPE)){
   yyParser *pParser;
-  pParser = (yyParser*)(*mallocProc)( (size_t)sizeof(yyParser) );
+  pParser = (yyParser*)(*mallocProc)( (YYMALLOCARGTYPE)sizeof(yyParser) );
   if( pParser ){
-    pParser->yyidx = -1;
 #ifdef YYTRACKMAXSTACKDEPTH
-    pParser->yyidxMax = 0;
+    pParser->yyhwm = 0;
 #endif
 #if YYSTACKDEPTH<=0
+    pParser->yytos = NULL;
     pParser->yystack = NULL;
     pParser->yystksz = 0;
-    yyGrowStack(pParser);
+    if( yyGrowStack(pParser) ){
+      pParser->yystack = &pParser->yystk0;
+      pParser->yystksz = 1;
+    }
+#endif
+#ifndef YYNOERRORRECOVERY
+    pParser->yyerrcnt = -1;
 #endif
+    pParser->yytos = pParser->yystack;
+    pParser->yystack[0].stateno = 0;
+    pParser->yystack[0].major = 0;
   }
   return pParser;
 }
 
-/* The following function deletes the value associated with a
-** symbol.  The symbol can be either a terminal or nonterminal.
-** "yymajor" is the symbol code, and "yypminor" is a pointer to
-** the value.
+/* The following function deletes the "minor type" or semantic value
+** associated with a symbol.  The symbol can be either a terminal
+** or nonterminal. "yymajor" is the symbol code, and "yypminor" is
+** a pointer to the value to be deleted.  The code used to do the 
+** deletions is derived from the %destructor and/or %token_destructor
+** directives of the input grammar.
 */
 static void yy_destructor(
   yyParser *yypParser,    /* The parser */
@@ -107306,75 +133051,84 @@ static void yy_destructor(
     ** being destroyed before it is finished parsing.
     **
     ** Note: during a reduce, the only symbols destroyed are those
-    ** which appear on the RHS of the rule, but which are not used
+    ** which appear on the RHS of the rule, but which are *not* used
     ** inside the C code.
     */
-    case 160: /* select */
-    case 194: /* oneselect */
+/********* Begin destructor definitions ***************************************/
+    case 163: /* select */
+    case 194: /* selectnowith */
+    case 195: /* oneselect */
+    case 206: /* values */
 {
-sqlite3SelectDelete(pParse->db, (yypminor->yy387));
+sqlite3SelectDelete(pParse->db, (yypminor->yy243));
 }
       break;
-    case 174: /* term */
-    case 175: /* expr */
+    case 172: /* term */
+    case 173: /* expr */
 {
-sqlite3ExprDelete(pParse->db, (yypminor->yy118).pExpr);
+sqlite3ExprDelete(pParse->db, (yypminor->yy190).pExpr);
 }
       break;
-    case 179: /* idxlist_opt */
-    case 187: /* idxlist */
-    case 197: /* selcollist */
-    case 200: /* groupby_opt */
-    case 202: /* orderby_opt */
-    case 204: /* sclp */
-    case 214: /* sortlist */
-    case 216: /* nexprlist */
-    case 217: /* setlist */
-    case 220: /* itemlist */
-    case 221: /* exprlist */
+    case 177: /* eidlist_opt */
+    case 186: /* sortlist */
+    case 187: /* eidlist */
+    case 199: /* selcollist */
+    case 202: /* groupby_opt */
+    case 204: /* orderby_opt */
+    case 207: /* nexprlist */
+    case 208: /* exprlist */
+    case 209: /* sclp */
+    case 218: /* setlist */
+    case 224: /* paren_exprlist */
     case 226: /* case_exprlist */
 {
-sqlite3ExprListDelete(pParse->db, (yypminor->yy322));
+sqlite3ExprListDelete(pParse->db, (yypminor->yy148));
 }
       break;
     case 193: /* fullname */
-    case 198: /* from */
-    case 206: /* seltablist */
-    case 207: /* stl_prefix */
+    case 200: /* from */
+    case 211: /* seltablist */
+    case 212: /* stl_prefix */
 {
-sqlite3SrcListDelete(pParse->db, (yypminor->yy259));
+sqlite3SrcListDelete(pParse->db, (yypminor->yy185));
 }
       break;
-    case 199: /* where_opt */
-    case 201: /* having_opt */
-    case 210: /* on_opt */
-    case 215: /* sortitem */
+    case 196: /* with */
+    case 250: /* wqlist */
+{
+sqlite3WithDelete(pParse->db, (yypminor->yy285));
+}
+      break;
+    case 201: /* where_opt */
+    case 203: /* having_opt */
+    case 215: /* on_opt */
     case 225: /* case_operand */
     case 227: /* case_else */
-    case 238: /* when_clause */
-    case 243: /* key_opt */
+    case 236: /* when_clause */
+    case 241: /* key_opt */
 {
-sqlite3ExprDelete(pParse->db, (yypminor->yy314));
+sqlite3ExprDelete(pParse->db, (yypminor->yy72));
 }
       break;
-    case 211: /* using_opt */
-    case 213: /* inscollist */
-    case 219: /* inscollist_opt */
+    case 216: /* using_opt */
+    case 217: /* idlist */
+    case 220: /* idlist_opt */
 {
-sqlite3IdListDelete(pParse->db, (yypminor->yy384));
+sqlite3IdListDelete(pParse->db, (yypminor->yy254));
 }
       break;
-    case 234: /* trigger_cmd_list */
-    case 239: /* trigger_cmd */
+    case 232: /* trigger_cmd_list */
+    case 237: /* trigger_cmd */
 {
-sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy203));
+sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy145));
 }
       break;
-    case 236: /* trigger_event */
+    case 234: /* trigger_event */
 {
-sqlite3IdListDelete(pParse->db, (yypminor->yy90).b);
+sqlite3IdListDelete(pParse->db, (yypminor->yy332).b);
 }
       break;
+/********* End destructor definitions *****************************************/
     default:  break;   /* If no destructor action specified: do nothing */
   }
 }
@@ -107384,52 +133138,41 @@ sqlite3IdListDelete(pParse->db, (yypminor->yy90).b);
 **
 ** If there is a destructor routine associated with the token which
 ** is popped from the stack, then call it.
-**
-** Return the major token number for the symbol popped.
 */
-static int yy_pop_parser_stack(yyParser *pParser){
-  YYCODETYPE yymajor;
-  yyStackEntry *yytos = &pParser->yystack[pParser->yyidx];
-
-  /* There is no mechanism by which the parser stack can be popped below
-  ** empty in SQLite.  */
-  if( NEVER(pParser->yyidx<0) ) return 0;
+static void yy_pop_parser_stack(yyParser *pParser){
+  yyStackEntry *yytos;
+  assert( pParser->yytos!=0 );
+  assert( pParser->yytos > pParser->yystack );
+  yytos = pParser->yytos--;
 #ifndef NDEBUG
-  if( yyTraceFILE && pParser->yyidx>=0 ){
+  if( yyTraceFILE ){
     fprintf(yyTraceFILE,"%sPopping %s\n",
       yyTracePrompt,
       yyTokenName[yytos->major]);
   }
 #endif
-  yymajor = yytos->major;
-  yy_destructor(pParser, yymajor, &yytos->minor);
-  pParser->yyidx--;
-  return yymajor;
+  yy_destructor(pParser, yytos->major, &yytos->minor);
 }
 
 /* 
-** Deallocate and destroy a parser.  Destructors are all called for
+** Deallocate and destroy a parser.  Destructors are called for
 ** all stack elements before shutting the parser down.
 **
-** Inputs:
-** <ul>
-** <li>  A pointer to the parser.  This should be a pointer
-**       obtained from sqlite3ParserAlloc.
-** <li>  A pointer to a function used to reclaim memory obtained
-**       from malloc.
-** </ul>
+** If the YYPARSEFREENEVERNULL macro exists (for example because it
+** is defined in a %include section of the input grammar) then it is
+** assumed that the input pointer is never NULL.
 */
 SQLITE_PRIVATE void sqlite3ParserFree(
   void *p,                    /* The parser to be deleted */
   void (*freeProc)(void*)     /* Function used to reclaim memory */
 ){
   yyParser *pParser = (yyParser*)p;
-  /* In SQLite, we never try to destroy a parser that was not successfully
-  ** created in the first place. */
-  if( NEVER(pParser==0) ) return;
-  while( pParser->yyidx>=0 ) yy_pop_parser_stack(pParser);
+#ifndef YYPARSEFREENEVERNULL
+  if( pParser==0 ) return;
+#endif
+  while( pParser->yytos>pParser->yystack ) yy_pop_parser_stack(pParser);
 #if YYSTACKDEPTH<=0
-  free(pParser->yystack);
+  if( pParser->yystack!=&pParser->yystk0 ) free(pParser->yystack);
 #endif
   (*freeProc)((void*)pParser);
 }
@@ -107440,82 +133183,79 @@ SQLITE_PRIVATE void sqlite3ParserFree(
 #ifdef YYTRACKMAXSTACKDEPTH
 SQLITE_PRIVATE int sqlite3ParserStackPeak(void *p){
   yyParser *pParser = (yyParser*)p;
-  return pParser->yyidxMax;
+  return pParser->yyhwm;
 }
 #endif
 
 /*
 ** Find the appropriate action for a parser given the terminal
 ** look-ahead token iLookAhead.
-**
-** If the look-ahead token is YYNOCODE, then check to see if the action is
-** independent of the look-ahead.  If it is, return the action, otherwise
-** return YY_NO_ACTION.
 */
-static int yy_find_shift_action(
+static unsigned int yy_find_shift_action(
   yyParser *pParser,        /* The parser */
   YYCODETYPE iLookAhead     /* The look-ahead token */
 ){
   int i;
-  int stateno = pParser->yystack[pParser->yyidx].stateno;
+  int stateno = pParser->yytos->stateno;
  
-  if( stateno>YY_SHIFT_COUNT
-   || (i = yy_shift_ofst[stateno])==YY_SHIFT_USE_DFLT ){
-    return yy_default[stateno];
-  }
-  assert( iLookAhead!=YYNOCODE );
-  i += iLookAhead;
-  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
-    if( iLookAhead>0 ){
+  if( stateno>=YY_MIN_REDUCE ) return stateno;
+  assert( stateno <= YY_SHIFT_COUNT );
+  do{
+    i = yy_shift_ofst[stateno];
+    if( i==YY_SHIFT_USE_DFLT ) return yy_default[stateno];
+    assert( iLookAhead!=YYNOCODE );
+    i += iLookAhead;
+    if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
+      if( iLookAhead>0 ){
 #ifdef YYFALLBACK
-      YYCODETYPE iFallback;            /* Fallback token */
-      if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])
-             && (iFallback = yyFallback[iLookAhead])!=0 ){
+        YYCODETYPE iFallback;            /* Fallback token */
+        if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])
+               && (iFallback = yyFallback[iLookAhead])!=0 ){
 #ifndef NDEBUG
-        if( yyTraceFILE ){
-          fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",
-             yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);
-        }
+          if( yyTraceFILE ){
+            fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",
+               yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);
+          }
 #endif
-        return yy_find_shift_action(pParser, iFallback);
-      }
+          assert( yyFallback[iFallback]==0 ); /* Fallback loop must terminate */
+          iLookAhead = iFallback;
+          continue;
+        }
 #endif
 #ifdef YYWILDCARD
-      {
-        int j = i - iLookAhead + YYWILDCARD;
-        if( 
+        {
+          int j = i - iLookAhead + YYWILDCARD;
+          if( 
 #if YY_SHIFT_MIN+YYWILDCARD<0
-          j>=0 &&
+            j>=0 &&
 #endif
 #if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT
-          j<YY_ACTTAB_COUNT &&
+            j<YY_ACTTAB_COUNT &&
 #endif
-          yy_lookahead[j]==YYWILDCARD
-        ){
+            yy_lookahead[j]==YYWILDCARD
+          ){
 #ifndef NDEBUG
-          if( yyTraceFILE ){
-            fprintf(yyTraceFILE, "%sWILDCARD %s => %s\n",
-               yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[YYWILDCARD]);
-          }
+            if( yyTraceFILE ){
+              fprintf(yyTraceFILE, "%sWILDCARD %s => %s\n",
+                 yyTracePrompt, yyTokenName[iLookAhead],
+                 yyTokenName[YYWILDCARD]);
+            }
 #endif /* NDEBUG */
-          return yy_action[j];
+            return yy_action[j];
+          }
         }
-      }
 #endif /* YYWILDCARD */
+      }
+      return yy_default[stateno];
+    }else{
+      return yy_action[i];
     }
-    return yy_default[stateno];
-  }else{
-    return yy_action[i];
-  }
+  }while(1);
 }
 
 /*
 ** Find the appropriate action for a parser given the non-terminal
 ** look-ahead token iLookAhead.
-**
-** If the look-ahead token is YYNOCODE, then check to see if the action is
-** independent of the look-ahead.  If it is, return the action, otherwise
-** return YY_NO_ACTION.
 */
 static int yy_find_reduce_action(
   int stateno,              /* Current state number */
@@ -107547,68 +133287,82 @@ static int yy_find_reduce_action(
 /*
 ** The following routine is called if the stack overflows.
 */
-static void yyStackOverflow(yyParser *yypParser, YYMINORTYPE *yypMinor){
+static void yyStackOverflow(yyParser *yypParser){
    sqlite3ParserARG_FETCH;
-   yypParser->yyidx--;
+   yypParser->yytos--;
 #ifndef NDEBUG
    if( yyTraceFILE ){
      fprintf(yyTraceFILE,"%sStack Overflow!\n",yyTracePrompt);
    }
 #endif
-   while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+   while( yypParser->yytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);
    /* Here code is inserted which will execute if the parser
    ** stack every overflows */
+/******** Begin %stack_overflow code ******************************************/
 
-  UNUSED_PARAMETER(yypMinor); /* Silence some compiler warnings */
   sqlite3ErrorMsg(pParse, "parser stack overflow");
-  pParse->parseError = 1;
+/******** End %stack_overflow code ********************************************/
    sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
 }
 
 /*
+** Print tracing information for a SHIFT action
+*/
+#ifndef NDEBUG
+static void yyTraceShift(yyParser *yypParser, int yyNewState){
+  if( yyTraceFILE ){
+    if( yyNewState<YYNSTATE ){
+      fprintf(yyTraceFILE,"%sShift '%s', go to state %d\n",
+         yyTracePrompt,yyTokenName[yypParser->yytos->major],
+         yyNewState);
+    }else{
+      fprintf(yyTraceFILE,"%sShift '%s'\n",
+         yyTracePrompt,yyTokenName[yypParser->yytos->major]);
+    }
+  }
+}
+#else
+# define yyTraceShift(X,Y)
+#endif
+
+/*
 ** Perform a shift action.
 */
 static void yy_shift(
   yyParser *yypParser,          /* The parser to be shifted */
   int yyNewState,               /* The new state to shift in */
   int yyMajor,                  /* The major token to shift in */
-  YYMINORTYPE *yypMinor         /* Pointer to the minor token to shift in */
+  sqlite3ParserTOKENTYPE yyMinor        /* The minor token to shift in */
 ){
   yyStackEntry *yytos;
-  yypParser->yyidx++;
+  yypParser->yytos++;
 #ifdef YYTRACKMAXSTACKDEPTH
-  if( yypParser->yyidx>yypParser->yyidxMax ){
-    yypParser->yyidxMax = yypParser->yyidx;
+  if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
+    yypParser->yyhwm++;
+    assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack) );
   }
 #endif
 #if YYSTACKDEPTH>0 
-  if( yypParser->yyidx>=YYSTACKDEPTH ){
-    yyStackOverflow(yypParser, yypMinor);
+  if( yypParser->yytos>=&yypParser->yystack[YYSTACKDEPTH] ){
+    yyStackOverflow(yypParser);
     return;
   }
 #else
-  if( yypParser->yyidx>=yypParser->yystksz ){
-    yyGrowStack(yypParser);
-    if( yypParser->yyidx>=yypParser->yystksz ){
-      yyStackOverflow(yypParser, yypMinor);
+  if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz] ){
+    if( yyGrowStack(yypParser) ){
+      yyStackOverflow(yypParser);
       return;
     }
   }
 #endif
-  yytos = &yypParser->yystack[yypParser->yyidx];
+  if( yyNewState > YY_MAX_SHIFT ){
+    yyNewState += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
+  }
+  yytos = yypParser->yytos;
   yytos->stateno = (YYACTIONTYPE)yyNewState;
   yytos->major = (YYCODETYPE)yyMajor;
-  yytos->minor = *yypMinor;
-#ifndef NDEBUG
-  if( yyTraceFILE && yypParser->yyidx>0 ){
-    int i;
-    fprintf(yyTraceFILE,"%sShift %d\n",yyTracePrompt,yyNewState);
-    fprintf(yyTraceFILE,"%sStack:",yyTracePrompt);
-    for(i=1; i<=yypParser->yyidx; i++)
-      fprintf(yyTraceFILE," %s",yyTokenName[yypParser->yystack[i].major]);
-    fprintf(yyTraceFILE,"\n");
-  }
-#endif
+  yytos->minor.yy0 = yyMinor;
+  yyTraceShift(yypParser, yyNewState);
 }
 
 /* The following table contains information about every rule that
@@ -107618,335 +133372,334 @@ static const struct {
   YYCODETYPE lhs;         /* Symbol on the left-hand side of the rule */
   unsigned char nrhs;     /* Number of right-hand side symbols in the rule */
 } yyRuleInfo[] = {
-  { 142, 1 },
-  { 143, 2 },
-  { 143, 1 },
-  { 144, 1 },
-  { 144, 3 },
-  { 145, 0 },
-  { 145, 1 },
-  { 145, 3 },
-  { 146, 1 },
+  { 147, 1 },
   { 147, 3 },
-  { 149, 0 },
-  { 149, 1 },
-  { 149, 2 },
-  { 148, 0 },
-  { 148, 1 },
   { 148, 1 },
-  { 148, 1 },
-  { 147, 2 },
-  { 147, 2 },
-  { 147, 2 },
-  { 151, 1 },
-  { 151, 0 },
-  { 147, 2 },
-  { 147, 3 },
-  { 147, 5 },
-  { 147, 2 },
-  { 152, 6 },
-  { 154, 1 },
-  { 156, 0 },
-  { 156, 3 },
-  { 155, 1 },
-  { 155, 0 },
-  { 153, 4 },
-  { 153, 2 },
-  { 158, 3 },
-  { 158, 1 },
-  { 161, 3 },
-  { 162, 1 },
-  { 165, 1 },
-  { 165, 1 },
-  { 166, 1 },
+  { 149, 3 },
+  { 150, 0 },
   { 150, 1 },
   { 150, 1 },
   { 150, 1 },
-  { 163, 0 },
-  { 163, 1 },
-  { 167, 1 },
-  { 167, 4 },
-  { 167, 6 },
-  { 168, 1 },
-  { 168, 2 },
-  { 169, 1 },
-  { 169, 1 },
+  { 149, 2 },
+  { 149, 2 },
+  { 149, 2 },
+  { 149, 2 },
+  { 149, 3 },
+  { 149, 5 },
+  { 154, 6 },
+  { 156, 1 },
+  { 158, 0 },
+  { 158, 3 },
+  { 157, 1 },
+  { 157, 0 },
+  { 155, 5 },
+  { 155, 2 },
+  { 162, 0 },
+  { 162, 2 },
   { 164, 2 },
-  { 164, 0 },
-  { 172, 3 },
-  { 172, 1 },
-  { 173, 2 },
-  { 173, 4 },
-  { 173, 3 },
-  { 173, 3 },
-  { 173, 2 },
-  { 173, 2 },
-  { 173, 3 },
-  { 173, 5 },
-  { 173, 2 },
-  { 173, 4 },
-  { 173, 4 },
-  { 173, 1 },
-  { 173, 2 },
+  { 166, 0 },
+  { 166, 4 },
+  { 166, 6 },
+  { 167, 2 },
+  { 171, 2 },
+  { 171, 2 },
+  { 171, 4 },
+  { 171, 3 },
+  { 171, 3 },
+  { 171, 2 },
+  { 171, 3 },
+  { 171, 5 },
+  { 171, 2 },
+  { 171, 4 },
+  { 171, 4 },
+  { 171, 1 },
+  { 171, 2 },
+  { 176, 0 },
+  { 176, 1 },
   { 178, 0 },
-  { 178, 1 },
-  { 180, 0 },
+  { 178, 2 },
   { 180, 2 },
-  { 182, 2 },
-  { 182, 3 },
-  { 182, 3 },
-  { 182, 3 },
-  { 183, 2 },
-  { 183, 2 },
-  { 183, 1 },
-  { 183, 1 },
-  { 183, 2 },
-  { 181, 3 },
+  { 180, 3 },
+  { 180, 3 },
+  { 180, 3 },
   { 181, 2 },
-  { 184, 0 },
-  { 184, 2 },
-  { 184, 2 },
-  { 159, 0 },
-  { 159, 2 },
-  { 185, 3 },
+  { 181, 2 },
+  { 181, 1 },
+  { 181, 1 },
+  { 181, 2 },
+  { 179, 3 },
+  { 179, 2 },
+  { 182, 0 },
+  { 182, 2 },
+  { 182, 2 },
+  { 161, 0 },
+  { 184, 1 },
   { 185, 2 },
-  { 185, 1 },
-  { 186, 2 },
-  { 186, 7 },
-  { 186, 5 },
-  { 186, 5 },
-  { 186, 10 },
+  { 185, 7 },
+  { 185, 5 },
+  { 185, 5 },
+  { 185, 10 },
   { 188, 0 },
-  { 188, 1 },
-  { 176, 0 },
-  { 176, 3 },
+  { 174, 0 },
+  { 174, 3 },
   { 189, 0 },
   { 189, 2 },
   { 190, 1 },
   { 190, 1 },
-  { 190, 1 },
-  { 147, 4 },
+  { 149, 4 },
   { 192, 2 },
   { 192, 0 },
-  { 147, 8 },
-  { 147, 4 },
-  { 147, 1 },
-  { 160, 1 },
-  { 160, 3 },
-  { 195, 1 },
-  { 195, 2 },
-  { 195, 1 },
-  { 194, 9 },
-  { 196, 1 },
-  { 196, 1 },
-  { 196, 0 },
-  { 204, 2 },
-  { 204, 0 },
-  { 197, 3 },
+  { 149, 9 },
+  { 149, 4 },
+  { 149, 1 },
+  { 163, 2 },
+  { 194, 3 },
+  { 197, 1 },
   { 197, 2 },
-  { 197, 4 },
-  { 205, 2 },
-  { 205, 1 },
-  { 205, 0 },
+  { 197, 1 },
+  { 195, 9 },
+  { 206, 4 },
+  { 206, 5 },
+  { 198, 1 },
+  { 198, 1 },
   { 198, 0 },
-  { 198, 2 },
-  { 207, 2 },
-  { 207, 0 },
-  { 206, 7 },
-  { 206, 7 },
-  { 206, 7 },
-  { 157, 0 },
-  { 157, 2 },
-  { 193, 2 },
-  { 208, 1 },
-  { 208, 2 },
-  { 208, 3 },
-  { 208, 4 },
+  { 209, 0 },
+  { 199, 3 },
+  { 199, 2 },
+  { 199, 4 },
   { 210, 2 },
   { 210, 0 },
-  { 209, 0 },
-  { 209, 3 },
-  { 209, 2 },
-  { 211, 4 },
-  { 211, 0 },
+  { 200, 0 },
+  { 200, 2 },
+  { 212, 2 },
+  { 212, 0 },
+  { 211, 7 },
+  { 211, 9 },
+  { 211, 7 },
+  { 211, 7 },
+  { 159, 0 },
+  { 159, 2 },
+  { 193, 2 },
+  { 213, 1 },
+  { 213, 2 },
+  { 213, 3 },
+  { 213, 4 },
+  { 215, 2 },
+  { 215, 0 },
+  { 214, 0 },
+  { 214, 3 },
+  { 214, 2 },
+  { 216, 4 },
+  { 216, 0 },
+  { 204, 0 },
+  { 204, 3 },
+  { 186, 4 },
+  { 186, 2 },
+  { 175, 1 },
+  { 175, 1 },
+  { 175, 0 },
   { 202, 0 },
   { 202, 3 },
-  { 214, 4 },
-  { 214, 2 },
-  { 215, 1 },
-  { 177, 1 },
-  { 177, 1 },
-  { 177, 0 },
-  { 200, 0 },
-  { 200, 3 },
-  { 201, 0 },
-  { 201, 2 },
   { 203, 0 },
   { 203, 2 },
-  { 203, 4 },
-  { 203, 4 },
-  { 147, 5 },
-  { 199, 0 },
-  { 199, 2 },
-  { 147, 7 },
-  { 217, 5 },
-  { 217, 3 },
-  { 147, 8 },
-  { 147, 5 },
-  { 147, 6 },
-  { 218, 2 },
-  { 218, 1 },
+  { 205, 0 },
+  { 205, 2 },
+  { 205, 4 },
+  { 205, 4 },
+  { 149, 6 },
+  { 201, 0 },
+  { 201, 2 },
+  { 149, 8 },
+  { 218, 5 },
+  { 218, 3 },
+  { 149, 6 },
+  { 149, 7 },
+  { 219, 2 },
+  { 219, 1 },
+  { 220, 0 },
   { 220, 3 },
-  { 220, 1 },
-  { 219, 0 },
-  { 219, 3 },
-  { 213, 3 },
-  { 213, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 174, 1 },
-  { 175, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 175, 5 },
-  { 174, 1 },
-  { 174, 1 },
-  { 175, 1 },
-  { 175, 1 },
-  { 175, 3 },
-  { 175, 6 },
-  { 175, 5 },
-  { 175, 4 },
-  { 174, 1 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 3 },
-  { 222, 1 },
-  { 222, 2 },
+  { 217, 3 },
+  { 217, 1 },
+  { 173, 3 },
+  { 172, 1 },
+  { 173, 1 },
+  { 173, 1 },
+  { 173, 3 },
+  { 173, 5 },
+  { 172, 1 },
+  { 172, 1 },
+  { 173, 1 },
+  { 173, 3 },
+  { 173, 6 },
+  { 173, 5 },
+  { 173, 4 },
+  { 172, 1 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 3 },
+  { 221, 1 },
+  { 221, 2 },
+  { 173, 3 },
+  { 173, 5 },
+  { 173, 2 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 4 },
+  { 173, 2 },
+  { 173, 2 },
+  { 173, 2 },
+  { 173, 2 },
   { 222, 1 },
   { 222, 2 },
-  { 175, 3 },
-  { 175, 5 },
-  { 175, 2 },
-  { 175, 3 },
-  { 175, 3 },
-  { 175, 4 },
-  { 175, 2 },
-  { 175, 2 },
-  { 175, 2 },
-  { 175, 2 },
+  { 173, 5 },
   { 223, 1 },
   { 223, 2 },
-  { 175, 5 },
-  { 224, 1 },
-  { 224, 2 },
-  { 175, 5 },
-  { 175, 3 },
-  { 175, 5 },
-  { 175, 4 },
-  { 175, 4 },
-  { 175, 5 },
+  { 173, 5 },
+  { 173, 3 },
+  { 173, 5 },
+  { 173, 5 },
+  { 173, 4 },
+  { 173, 5 },
   { 226, 5 },
   { 226, 4 },
   { 227, 2 },
   { 227, 0 },
   { 225, 1 },
   { 225, 0 },
-  { 221, 1 },
-  { 221, 0 },
-  { 216, 3 },
-  { 216, 1 },
-  { 147, 11 },
+  { 208, 0 },
+  { 207, 3 },
+  { 207, 1 },
+  { 224, 0 },
+  { 224, 3 },
+  { 149, 12 },
   { 228, 1 },
   { 228, 0 },
-  { 179, 0 },
-  { 179, 3 },
+  { 177, 0 },
+  { 177, 3 },
   { 187, 5 },
   { 187, 3 },
   { 229, 0 },
   { 229, 2 },
-  { 147, 4 },
-  { 147, 1 },
-  { 147, 2 },
-  { 147, 3 },
-  { 147, 5 },
-  { 147, 6 },
-  { 147, 5 },
-  { 147, 6 },
+  { 149, 4 },
+  { 149, 1 },
+  { 149, 2 },
+  { 149, 3 },
+  { 149, 5 },
+  { 149, 6 },
+  { 149, 5 },
+  { 149, 6 },
+  { 169, 2 },
+  { 170, 2 },
+  { 149, 5 },
+  { 231, 11 },
+  { 233, 1 },
+  { 233, 1 },
+  { 233, 2 },
+  { 233, 0 },
+  { 234, 1 },
+  { 234, 1 },
+  { 234, 3 },
+  { 236, 0 },
+  { 236, 2 },
+  { 232, 3 },
+  { 232, 2 },
+  { 238, 3 },
+  { 239, 3 },
+  { 239, 2 },
+  { 237, 7 },
+  { 237, 5 },
+  { 237, 5 },
+  { 237, 1 },
+  { 173, 4 },
+  { 173, 6 },
+  { 191, 1 },
+  { 191, 1 },
+  { 191, 1 },
+  { 149, 4 },
+  { 149, 6 },
+  { 149, 3 },
+  { 241, 0 },
+  { 241, 2 },
+  { 149, 1 },
+  { 149, 3 },
+  { 149, 1 },
+  { 149, 3 },
+  { 149, 6 },
+  { 149, 7 },
+  { 242, 1 },
+  { 149, 1 },
+  { 149, 4 },
+  { 244, 8 },
+  { 246, 0 },
+  { 247, 1 },
+  { 247, 3 },
+  { 248, 1 },
+  { 196, 0 },
+  { 196, 2 },
+  { 196, 3 },
+  { 250, 6 },
+  { 250, 8 },
+  { 144, 1 },
+  { 145, 2 },
+  { 145, 1 },
+  { 146, 1 },
+  { 146, 3 },
+  { 147, 0 },
+  { 151, 0 },
+  { 151, 1 },
+  { 151, 2 },
+  { 153, 1 },
+  { 153, 0 },
+  { 149, 2 },
+  { 160, 4 },
+  { 160, 2 },
+  { 152, 1 },
+  { 152, 1 },
+  { 152, 1 },
+  { 166, 1 },
+  { 167, 1 },
+  { 168, 1 },
+  { 168, 1 },
+  { 165, 2 },
+  { 165, 0 },
+  { 171, 2 },
+  { 161, 2 },
+  { 183, 3 },
+  { 183, 1 },
+  { 184, 0 },
+  { 188, 1 },
+  { 190, 1 },
+  { 194, 1 },
+  { 195, 1 },
+  { 209, 2 },
+  { 210, 1 },
+  { 173, 1 },
+  { 208, 1 },
   { 230, 1 },
   { 230, 1 },
   { 230, 1 },
   { 230, 1 },
   { 230, 1 },
-  { 170, 2 },
-  { 171, 2 },
-  { 232, 1 },
-  { 231, 1 },
-  { 231, 0 },
-  { 147, 5 },
-  { 233, 11 },
-  { 235, 1 },
-  { 235, 1 },
-  { 235, 2 },
+  { 169, 1 },
   { 235, 0 },
-  { 236, 1 },
-  { 236, 1 },
-  { 236, 3 },
-  { 237, 0 },
-  { 237, 3 },
-  { 238, 0 },
-  { 238, 2 },
-  { 234, 3 },
-  { 234, 2 },
+  { 235, 3 },
+  { 238, 1 },
+  { 239, 0 },
   { 240, 1 },
-  { 240, 3 },
-  { 241, 0 },
-  { 241, 3 },
-  { 241, 2 },
-  { 239, 7 },
-  { 239, 8 },
-  { 239, 5 },
-  { 239, 5 },
-  { 239, 1 },
-  { 175, 4 },
-  { 175, 6 },
-  { 191, 1 },
-  { 191, 1 },
-  { 191, 1 },
-  { 147, 4 },
-  { 147, 6 },
-  { 147, 3 },
+  { 240, 0 },
   { 243, 0 },
-  { 243, 2 },
-  { 242, 1 },
-  { 242, 0 },
-  { 147, 1 },
-  { 147, 3 },
-  { 147, 1 },
-  { 147, 3 },
-  { 147, 6 },
-  { 147, 6 },
-  { 244, 1 },
-  { 245, 0 },
+  { 243, 1 },
   { 245, 1 },
-  { 147, 1 },
-  { 147, 4 },
-  { 246, 7 },
-  { 247, 1 },
-  { 247, 3 },
-  { 248, 0 },
-  { 248, 2 },
-  { 249, 1 },
-  { 249, 3 },
-  { 250, 1 },
-  { 251, 0 },
-  { 251, 4 },
-  { 251, 2 },
+  { 245, 3 },
+  { 246, 2 },
+  { 249, 0 },
+  { 249, 4 },
+  { 249, 2 },
 };
 
 static void yy_accept(yyParser*);  /* Forward Declaration */
@@ -107957,40 +133710,47 @@ static void yy_accept(yyParser*);  /* Forward Declaration */
 */
 static void yy_reduce(
   yyParser *yypParser,         /* The parser */
-  int yyruleno                 /* Number of the rule by which to reduce */
+  unsigned int yyruleno        /* Number of the rule by which to reduce */
 ){
   int yygoto;                     /* The next state */
   int yyact;                      /* The next action */
-  YYMINORTYPE yygotominor;        /* The LHS of the rule reduced */
   yyStackEntry *yymsp;            /* The top of the parser's stack */
   int yysize;                     /* Amount to pop the stack */
   sqlite3ParserARG_FETCH;
-  yymsp = &yypParser->yystack[yypParser->yyidx];
+  yymsp = yypParser->yytos;
 #ifndef NDEBUG
-  if( yyTraceFILE && yyruleno>=0 
-        && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
-    fprintf(yyTraceFILE, "%sReduce [%s].\n", yyTracePrompt,
-      yyRuleName[yyruleno]);
+  if( yyTraceFILE && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
+    yysize = yyRuleInfo[yyruleno].nrhs;
+    fprintf(yyTraceFILE, "%sReduce [%s], go to state %d.\n", yyTracePrompt,
+      yyRuleName[yyruleno], yymsp[-yysize].stateno);
   }
 #endif /* NDEBUG */
 
-  /* Silence complaints from purify about yygotominor being uninitialized
-  ** in some cases when it is copied into the stack after the following
-  ** switch.  yygotominor is uninitialized when a rule reduces that does
-  ** not set the value of its left-hand side nonterminal.  Leaving the
-  ** value of the nonterminal uninitialized is utterly harmless as long
-  ** as the value is never used.  So really the only thing this code
-  ** accomplishes is to quieten purify.  
-  **
-  ** 2007-01-16:  The wireshark project (www.wireshark.org) reports that
-  ** without this code, their parser segfaults.  I'm not sure what there
-  ** parser is doing to make this happen.  This is the second bug report
-  ** from wireshark this week.  Clearly they are stressing Lemon in ways
-  ** that it has not been previously stressed...  (SQLite ticket #2172)
-  */
-  /*memset(&yygotominor, 0, sizeof(yygotominor));*/
-  yygotominor = yyzerominor;
-
+  /* Check that the stack is large enough to grow by a single entry
+  ** if the RHS of the rule is empty.  This ensures that there is room
+  ** enough on the stack to push the LHS value */
+  if( yyRuleInfo[yyruleno].nrhs==0 ){
+#ifdef YYTRACKMAXSTACKDEPTH
+    if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
+      yypParser->yyhwm++;
+      assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack));
+    }
+#endif
+#if YYSTACKDEPTH>0 
+    if( yypParser->yytos>=&yypParser->yystack[YYSTACKDEPTH-1] ){
+      yyStackOverflow(yypParser);
+      return;
+    }
+#else
+    if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz-1] ){
+      if( yyGrowStack(yypParser) ){
+        yyStackOverflow(yypParser);
+        return;
+      }
+      yymsp = yypParser->yytos;
+    }
+#endif
+  }
 
   switch( yyruleno ){
   /* Beginning here are the reduction cases.  A typical example
@@ -108001,711 +133761,776 @@ static void yy_reduce(
   **  #line <lineno> <thisfile>
   **     break;
   */
-      case 5: /* explain ::= */
-{ sqlite3BeginParse(pParse, 0); }
-        break;
-      case 6: /* explain ::= EXPLAIN */
-{ sqlite3BeginParse(pParse, 1); }
+/********** Begin reduce actions **********************************************/
+        YYMINORTYPE yylhsminor;
+      case 0: /* explain ::= EXPLAIN */
+{ pParse->explain = 1; }
         break;
-      case 7: /* explain ::= EXPLAIN QUERY PLAN */
-{ sqlite3BeginParse(pParse, 2); }
+      case 1: /* explain ::= EXPLAIN QUERY PLAN */
+{ pParse->explain = 2; }
         break;
-      case 8: /* cmdx ::= cmd */
+      case 2: /* cmdx ::= cmd */
 { sqlite3FinishCoding(pParse); }
         break;
-      case 9: /* cmd ::= BEGIN transtype trans_opt */
-{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy4);}
+      case 3: /* cmd ::= BEGIN transtype trans_opt */
+{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy194);}
         break;
-      case 13: /* transtype ::= */
-{yygotominor.yy4 = TK_DEFERRED;}
+      case 4: /* transtype ::= */
+{yymsp[1].minor.yy194 = TK_DEFERRED;}
         break;
-      case 14: /* transtype ::= DEFERRED */
-      case 15: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==15);
-      case 16: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==16);
-      case 115: /* multiselect_op ::= UNION */ yytestcase(yyruleno==115);
-      case 117: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==117);
-{yygotominor.yy4 = yymsp[0].major;}
+      case 5: /* transtype ::= DEFERRED */
+      case 6: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==6);
+      case 7: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==7);
+{yymsp[0].minor.yy194 = yymsp[0].major; /*A-overwrites-X*/}
         break;
-      case 17: /* cmd ::= COMMIT trans_opt */
-      case 18: /* cmd ::= END trans_opt */ yytestcase(yyruleno==18);
+      case 8: /* cmd ::= COMMIT trans_opt */
+      case 9: /* cmd ::= END trans_opt */ yytestcase(yyruleno==9);
 {sqlite3CommitTransaction(pParse);}
         break;
-      case 19: /* cmd ::= ROLLBACK trans_opt */
+      case 10: /* cmd ::= ROLLBACK trans_opt */
 {sqlite3RollbackTransaction(pParse);}
         break;
-      case 22: /* cmd ::= SAVEPOINT nm */
+      case 11: /* cmd ::= SAVEPOINT nm */
 {
   sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &yymsp[0].minor.yy0);
 }
         break;
-      case 23: /* cmd ::= RELEASE savepoint_opt nm */
+      case 12: /* cmd ::= RELEASE savepoint_opt nm */
 {
   sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &yymsp[0].minor.yy0);
 }
         break;
-      case 24: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */
+      case 13: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */
 {
   sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &yymsp[0].minor.yy0);
 }
         break;
-      case 26: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
+      case 14: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
 {
-   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy4,0,0,yymsp[-2].minor.yy4);
+   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy194,0,0,yymsp[-2].minor.yy194);
 }
         break;
-      case 27: /* createkw ::= CREATE */
-{
-  pParse->db->lookaside.bEnabled = 0;
-  yygotominor.yy0 = yymsp[0].minor.yy0;
-}
+      case 15: /* createkw ::= CREATE */
+{disableLookaside(pParse);}
         break;
-      case 28: /* ifnotexists ::= */
-      case 31: /* temp ::= */ yytestcase(yyruleno==31);
-      case 70: /* autoinc ::= */ yytestcase(yyruleno==70);
-      case 83: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */ yytestcase(yyruleno==83);
-      case 85: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==85);
-      case 87: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */ yytestcase(yyruleno==87);
-      case 98: /* defer_subclause_opt ::= */ yytestcase(yyruleno==98);
-      case 109: /* ifexists ::= */ yytestcase(yyruleno==109);
-      case 120: /* distinct ::= ALL */ yytestcase(yyruleno==120);
-      case 121: /* distinct ::= */ yytestcase(yyruleno==121);
-      case 222: /* between_op ::= BETWEEN */ yytestcase(yyruleno==222);
-      case 225: /* in_op ::= IN */ yytestcase(yyruleno==225);
-{yygotominor.yy4 = 0;}
+      case 16: /* ifnotexists ::= */
+      case 19: /* temp ::= */ yytestcase(yyruleno==19);
+      case 22: /* table_options ::= */ yytestcase(yyruleno==22);
+      case 42: /* autoinc ::= */ yytestcase(yyruleno==42);
+      case 57: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==57);
+      case 67: /* defer_subclause_opt ::= */ yytestcase(yyruleno==67);
+      case 76: /* ifexists ::= */ yytestcase(yyruleno==76);
+      case 90: /* distinct ::= */ yytestcase(yyruleno==90);
+      case 211: /* collate ::= */ yytestcase(yyruleno==211);
+{yymsp[1].minor.yy194 = 0;}
         break;
-      case 29: /* ifnotexists ::= IF NOT EXISTS */
-      case 30: /* temp ::= TEMP */ yytestcase(yyruleno==30);
-      case 71: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==71);
-      case 86: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */ yytestcase(yyruleno==86);
-      case 108: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==108);
-      case 119: /* distinct ::= DISTINCT */ yytestcase(yyruleno==119);
-      case 223: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==223);
-      case 226: /* in_op ::= NOT IN */ yytestcase(yyruleno==226);
-{yygotominor.yy4 = 1;}
+      case 17: /* ifnotexists ::= IF NOT EXISTS */
+{yymsp[-2].minor.yy194 = 1;}
         break;
-      case 32: /* create_table_args ::= LP columnlist conslist_opt RP */
-{
-  sqlite3EndTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0);
-}
+      case 18: /* temp ::= TEMP */
+      case 43: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==43);
+{yymsp[0].minor.yy194 = 1;}
         break;
-      case 33: /* create_table_args ::= AS select */
+      case 20: /* create_table_args ::= LP columnlist conslist_opt RP table_options */
 {
-  sqlite3EndTable(pParse,0,0,yymsp[0].minor.yy387);
-  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy387);
+  sqlite3EndTable(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,yymsp[0].minor.yy194,0);
 }
         break;
-      case 36: /* column ::= columnid type carglist */
+      case 21: /* create_table_args ::= AS select */
 {
-  yygotominor.yy0.z = yymsp[-2].minor.yy0.z;
-  yygotominor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-2].minor.yy0.z) + pParse->sLastToken.n;
+  sqlite3EndTable(pParse,0,0,0,yymsp[0].minor.yy243);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy243);
 }
         break;
-      case 37: /* columnid ::= nm */
+      case 23: /* table_options ::= WITHOUT nm */
 {
-  sqlite3AddColumn(pParse,&yymsp[0].minor.yy0);
-  yygotominor.yy0 = yymsp[0].minor.yy0;
+  if( yymsp[0].minor.yy0.n==5 && sqlite3_strnicmp(yymsp[0].minor.yy0.z,"rowid",5)==0 ){
+    yymsp[-1].minor.yy194 = TF_WithoutRowid | TF_NoVisibleRowid;
+  }else{
+    yymsp[-1].minor.yy194 = 0;
+    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", yymsp[0].minor.yy0.n, yymsp[0].minor.yy0.z);
+  }
 }
         break;
-      case 38: /* id ::= ID */
-      case 39: /* id ::= INDEXED */ yytestcase(yyruleno==39);
-      case 40: /* ids ::= ID|STRING */ yytestcase(yyruleno==40);
-      case 41: /* nm ::= id */ yytestcase(yyruleno==41);
-      case 42: /* nm ::= STRING */ yytestcase(yyruleno==42);
-      case 43: /* nm ::= JOIN_KW */ yytestcase(yyruleno==43);
-      case 46: /* typetoken ::= typename */ yytestcase(yyruleno==46);
-      case 49: /* typename ::= ids */ yytestcase(yyruleno==49);
-      case 127: /* as ::= AS nm */ yytestcase(yyruleno==127);
-      case 128: /* as ::= ids */ yytestcase(yyruleno==128);
-      case 138: /* dbnm ::= DOT nm */ yytestcase(yyruleno==138);
-      case 147: /* indexed_opt ::= INDEXED BY nm */ yytestcase(yyruleno==147);
-      case 251: /* collate ::= COLLATE ids */ yytestcase(yyruleno==251);
-      case 260: /* nmnum ::= plus_num */ yytestcase(yyruleno==260);
-      case 261: /* nmnum ::= nm */ yytestcase(yyruleno==261);
-      case 262: /* nmnum ::= ON */ yytestcase(yyruleno==262);
-      case 263: /* nmnum ::= DELETE */ yytestcase(yyruleno==263);
-      case 264: /* nmnum ::= DEFAULT */ yytestcase(yyruleno==264);
-      case 265: /* plus_num ::= plus_opt number */ yytestcase(yyruleno==265);
-      case 266: /* minus_num ::= MINUS number */ yytestcase(yyruleno==266);
-      case 267: /* number ::= INTEGER|FLOAT */ yytestcase(yyruleno==267);
-      case 285: /* trnm ::= nm */ yytestcase(yyruleno==285);
-{yygotominor.yy0 = yymsp[0].minor.yy0;}
+      case 24: /* columnname ::= nm typetoken */
+{sqlite3AddColumn(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}
         break;
-      case 45: /* type ::= typetoken */
-{sqlite3AddColumnType(pParse,&yymsp[0].minor.yy0);}
+      case 25: /* typetoken ::= */
+      case 60: /* conslist_opt ::= */ yytestcase(yyruleno==60);
+      case 96: /* as ::= */ yytestcase(yyruleno==96);
+{yymsp[1].minor.yy0.n = 0; yymsp[1].minor.yy0.z = 0;}
         break;
-      case 47: /* typetoken ::= typename LP signed RP */
+      case 26: /* typetoken ::= typename LP signed RP */
 {
-  yygotominor.yy0.z = yymsp[-3].minor.yy0.z;
-  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);
+  yymsp[-3].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);
 }
         break;
-      case 48: /* typetoken ::= typename LP signed COMMA signed RP */
+      case 27: /* typetoken ::= typename LP signed COMMA signed RP */
 {
-  yygotominor.yy0.z = yymsp[-5].minor.yy0.z;
-  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);
+  yymsp[-5].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);
 }
         break;
-      case 50: /* typename ::= typename ids */
-{yygotominor.yy0.z=yymsp[-1].minor.yy0.z; yygotominor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}
+      case 28: /* typename ::= typename ID|STRING */
+{yymsp[-1].minor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}
         break;
-      case 57: /* ccons ::= DEFAULT term */
-      case 59: /* ccons ::= DEFAULT PLUS term */ yytestcase(yyruleno==59);
-{sqlite3AddDefaultValue(pParse,&yymsp[0].minor.yy118);}
+      case 29: /* ccons ::= CONSTRAINT nm */
+      case 62: /* tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==62);
+{pParse->constraintName = yymsp[0].minor.yy0;}
         break;
-      case 58: /* ccons ::= DEFAULT LP expr RP */
-{sqlite3AddDefaultValue(pParse,&yymsp[-1].minor.yy118);}
+      case 30: /* ccons ::= DEFAULT term */
+      case 32: /* ccons ::= DEFAULT PLUS term */ yytestcase(yyruleno==32);
+{sqlite3AddDefaultValue(pParse,&yymsp[0].minor.yy190);}
         break;
-      case 60: /* ccons ::= DEFAULT MINUS term */
+      case 31: /* ccons ::= DEFAULT LP expr RP */
+{sqlite3AddDefaultValue(pParse,&yymsp[-1].minor.yy190);}
+        break;
+      case 33: /* ccons ::= DEFAULT MINUS term */
 {
   ExprSpan v;
-  v.pExpr = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy118.pExpr, 0, 0);
+  v.pExpr = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy190.pExpr, 0, 0);
   v.zStart = yymsp[-1].minor.yy0.z;
-  v.zEnd = yymsp[0].minor.yy118.zEnd;
+  v.zEnd = yymsp[0].minor.yy190.zEnd;
   sqlite3AddDefaultValue(pParse,&v);
 }
         break;
-      case 61: /* ccons ::= DEFAULT id */
+      case 34: /* ccons ::= DEFAULT ID|INDEXED */
 {
   ExprSpan v;
-  spanExpr(&v, pParse, TK_STRING, &yymsp[0].minor.yy0);
+  spanExpr(&v, pParse, TK_STRING, yymsp[0].minor.yy0);
   sqlite3AddDefaultValue(pParse,&v);
 }
         break;
-      case 63: /* ccons ::= NOT NULL onconf */
-{sqlite3AddNotNull(pParse, yymsp[0].minor.yy4);}
+      case 35: /* ccons ::= NOT NULL onconf */
+{sqlite3AddNotNull(pParse, yymsp[0].minor.yy194);}
         break;
-      case 64: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */
-{sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy4,yymsp[0].minor.yy4,yymsp[-2].minor.yy4);}
+      case 36: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */
+{sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy194,yymsp[0].minor.yy194,yymsp[-2].minor.yy194);}
         break;
-      case 65: /* ccons ::= UNIQUE onconf */
-{sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy4,0,0,0,0);}
+      case 37: /* ccons ::= UNIQUE onconf */
+{sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy194,0,0,0,0,
+                                   SQLITE_IDXTYPE_UNIQUE);}
         break;
-      case 66: /* ccons ::= CHECK LP expr RP */
-{sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy118.pExpr);}
+      case 38: /* ccons ::= CHECK LP expr RP */
+{sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy190.pExpr);}
         break;
-      case 67: /* ccons ::= REFERENCES nm idxlist_opt refargs */
-{sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy322,yymsp[0].minor.yy4);}
+      case 39: /* ccons ::= REFERENCES nm eidlist_opt refargs */
+{sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy148,yymsp[0].minor.yy194);}
         break;
-      case 68: /* ccons ::= defer_subclause */
-{sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy4);}
+      case 40: /* ccons ::= defer_subclause */
+{sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy194);}
         break;
-      case 69: /* ccons ::= COLLATE ids */
+      case 41: /* ccons ::= COLLATE ID|STRING */
 {sqlite3AddCollateType(pParse, &yymsp[0].minor.yy0);}
         break;
-      case 72: /* refargs ::= */
-{ yygotominor.yy4 = OE_None*0x0101; /* EV: R-19803-45884 */}
+      case 44: /* refargs ::= */
+{ yymsp[1].minor.yy194 = OE_None*0x0101; /* EV: R-19803-45884 */}
+        break;
+      case 45: /* refargs ::= refargs refarg */
+{ yymsp[-1].minor.yy194 = (yymsp[-1].minor.yy194 & ~yymsp[0].minor.yy497.mask) | yymsp[0].minor.yy497.value; }
         break;
-      case 73: /* refargs ::= refargs refarg */
-{ yygotominor.yy4 = (yymsp[-1].minor.yy4 & ~yymsp[0].minor.yy215.mask) | yymsp[0].minor.yy215.value; }
+      case 46: /* refarg ::= MATCH nm */
+{ yymsp[-1].minor.yy497.value = 0;     yymsp[-1].minor.yy497.mask = 0x000000; }
         break;
-      case 74: /* refarg ::= MATCH nm */
-      case 75: /* refarg ::= ON INSERT refact */ yytestcase(yyruleno==75);
-{ yygotominor.yy215.value = 0;     yygotominor.yy215.mask = 0x000000; }
+      case 47: /* refarg ::= ON INSERT refact */
+{ yymsp[-2].minor.yy497.value = 0;     yymsp[-2].minor.yy497.mask = 0x000000; }
         break;
-      case 76: /* refarg ::= ON DELETE refact */
-{ yygotominor.yy215.value = yymsp[0].minor.yy4;     yygotominor.yy215.mask = 0x0000ff; }
+      case 48: /* refarg ::= ON DELETE refact */
+{ yymsp[-2].minor.yy497.value = yymsp[0].minor.yy194;     yymsp[-2].minor.yy497.mask = 0x0000ff; }
         break;
-      case 77: /* refarg ::= ON UPDATE refact */
-{ yygotominor.yy215.value = yymsp[0].minor.yy4<<8;  yygotominor.yy215.mask = 0x00ff00; }
+      case 49: /* refarg ::= ON UPDATE refact */
+{ yymsp[-2].minor.yy497.value = yymsp[0].minor.yy194<<8;  yymsp[-2].minor.yy497.mask = 0x00ff00; }
         break;
-      case 78: /* refact ::= SET NULL */
-{ yygotominor.yy4 = OE_SetNull;  /* EV: R-33326-45252 */}
+      case 50: /* refact ::= SET NULL */
+{ yymsp[-1].minor.yy194 = OE_SetNull;  /* EV: R-33326-45252 */}
         break;
-      case 79: /* refact ::= SET DEFAULT */
-{ yygotominor.yy4 = OE_SetDflt;  /* EV: R-33326-45252 */}
+      case 51: /* refact ::= SET DEFAULT */
+{ yymsp[-1].minor.yy194 = OE_SetDflt;  /* EV: R-33326-45252 */}
         break;
-      case 80: /* refact ::= CASCADE */
-{ yygotominor.yy4 = OE_Cascade;  /* EV: R-33326-45252 */}
+      case 52: /* refact ::= CASCADE */
+{ yymsp[0].minor.yy194 = OE_Cascade;  /* EV: R-33326-45252 */}
         break;
-      case 81: /* refact ::= RESTRICT */
-{ yygotominor.yy4 = OE_Restrict; /* EV: R-33326-45252 */}
+      case 53: /* refact ::= RESTRICT */
+{ yymsp[0].minor.yy194 = OE_Restrict; /* EV: R-33326-45252 */}
         break;
-      case 82: /* refact ::= NO ACTION */
-{ yygotominor.yy4 = OE_None;     /* EV: R-33326-45252 */}
+      case 54: /* refact ::= NO ACTION */
+{ yymsp[-1].minor.yy194 = OE_None;     /* EV: R-33326-45252 */}
         break;
-      case 84: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */
-      case 99: /* defer_subclause_opt ::= defer_subclause */ yytestcase(yyruleno==99);
-      case 101: /* onconf ::= ON CONFLICT resolvetype */ yytestcase(yyruleno==101);
-      case 104: /* resolvetype ::= raisetype */ yytestcase(yyruleno==104);
-{yygotominor.yy4 = yymsp[0].minor.yy4;}
+      case 55: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */
+{yymsp[-2].minor.yy194 = 0;}
         break;
-      case 88: /* conslist_opt ::= */
-{yygotominor.yy0.n = 0; yygotominor.yy0.z = 0;}
+      case 56: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */
+      case 71: /* orconf ::= OR resolvetype */ yytestcase(yyruleno==71);
+      case 142: /* insert_cmd ::= INSERT orconf */ yytestcase(yyruleno==142);
+{yymsp[-1].minor.yy194 = yymsp[0].minor.yy194;}
         break;
-      case 89: /* conslist_opt ::= COMMA conslist */
-{yygotominor.yy0 = yymsp[-1].minor.yy0;}
+      case 58: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */
+      case 75: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==75);
+      case 183: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==183);
+      case 186: /* in_op ::= NOT IN */ yytestcase(yyruleno==186);
+      case 212: /* collate ::= COLLATE ID|STRING */ yytestcase(yyruleno==212);
+{yymsp[-1].minor.yy194 = 1;}
         break;
-      case 94: /* tcons ::= PRIMARY KEY LP idxlist autoinc RP onconf */
-{sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy322,yymsp[0].minor.yy4,yymsp[-2].minor.yy4,0);}
+      case 59: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */
+{yymsp[-1].minor.yy194 = 0;}
         break;
-      case 95: /* tcons ::= UNIQUE LP idxlist RP onconf */
-{sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy322,yymsp[0].minor.yy4,0,0,0,0);}
+      case 61: /* tconscomma ::= COMMA */
+{pParse->constraintName.n = 0;}
         break;
-      case 96: /* tcons ::= CHECK LP expr RP onconf */
-{sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy118.pExpr);}
+      case 63: /* tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */
+{sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy148,yymsp[0].minor.yy194,yymsp[-2].minor.yy194,0);}
         break;
-      case 97: /* tcons ::= FOREIGN KEY LP idxlist RP REFERENCES nm idxlist_opt refargs defer_subclause_opt */
+      case 64: /* tcons ::= UNIQUE LP sortlist RP onconf */
+{sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy148,yymsp[0].minor.yy194,0,0,0,0,
+                                       SQLITE_IDXTYPE_UNIQUE);}
+        break;
+      case 65: /* tcons ::= CHECK LP expr RP onconf */
+{sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy190.pExpr);}
+        break;
+      case 66: /* tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */
 {
-    sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy322, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy322, yymsp[-1].minor.yy4);
-    sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy4);
+    sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy148, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy148, yymsp[-1].minor.yy194);
+    sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy194);
 }
         break;
-      case 100: /* onconf ::= */
-{yygotominor.yy4 = OE_Default;}
-        break;
-      case 102: /* orconf ::= */
-{yygotominor.yy210 = OE_Default;}
+      case 68: /* onconf ::= */
+      case 70: /* orconf ::= */ yytestcase(yyruleno==70);
+{yymsp[1].minor.yy194 = OE_Default;}
         break;
-      case 103: /* orconf ::= OR resolvetype */
-{yygotominor.yy210 = (u8)yymsp[0].minor.yy4;}
+      case 69: /* onconf ::= ON CONFLICT resolvetype */
+{yymsp[-2].minor.yy194 = yymsp[0].minor.yy194;}
         break;
-      case 105: /* resolvetype ::= IGNORE */
-{yygotominor.yy4 = OE_Ignore;}
+      case 72: /* resolvetype ::= IGNORE */
+{yymsp[0].minor.yy194 = OE_Ignore;}
         break;
-      case 106: /* resolvetype ::= REPLACE */
-{yygotominor.yy4 = OE_Replace;}
+      case 73: /* resolvetype ::= REPLACE */
+      case 143: /* insert_cmd ::= REPLACE */ yytestcase(yyruleno==143);
+{yymsp[0].minor.yy194 = OE_Replace;}
         break;
-      case 107: /* cmd ::= DROP TABLE ifexists fullname */
+      case 74: /* cmd ::= DROP TABLE ifexists fullname */
 {
-  sqlite3DropTable(pParse, yymsp[0].minor.yy259, 0, yymsp[-1].minor.yy4);
+  sqlite3DropTable(pParse, yymsp[0].minor.yy185, 0, yymsp[-1].minor.yy194);
 }
         break;
-      case 110: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm AS select */
+      case 77: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */
 {
-  sqlite3CreateView(pParse, &yymsp[-7].minor.yy0, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, yymsp[0].minor.yy387, yymsp[-6].minor.yy4, yymsp[-4].minor.yy4);
+  sqlite3CreateView(pParse, &yymsp[-8].minor.yy0, &yymsp[-4].minor.yy0, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy148, yymsp[0].minor.yy243, yymsp[-7].minor.yy194, yymsp[-5].minor.yy194);
 }
         break;
-      case 111: /* cmd ::= DROP VIEW ifexists fullname */
+      case 78: /* cmd ::= DROP VIEW ifexists fullname */
 {
-  sqlite3DropTable(pParse, yymsp[0].minor.yy259, 1, yymsp[-1].minor.yy4);
+  sqlite3DropTable(pParse, yymsp[0].minor.yy185, 1, yymsp[-1].minor.yy194);
 }
         break;
-      case 112: /* cmd ::= select */
+      case 79: /* cmd ::= select */
 {
-  SelectDest dest = {SRT_Output, 0, 0, 0, 0};
-  sqlite3Select(pParse, yymsp[0].minor.yy387, &dest);
-  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy387);
+  SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};
+  sqlite3Select(pParse, yymsp[0].minor.yy243, &dest);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy243);
 }
         break;
-      case 113: /* select ::= oneselect */
-{yygotominor.yy387 = yymsp[0].minor.yy387;}
+      case 80: /* select ::= with selectnowith */
+{
+  Select *p = yymsp[0].minor.yy243;
+  if( p ){
+    p->pWith = yymsp[-1].minor.yy285;
+    parserDoubleLinkSelect(pParse, p);
+  }else{
+    sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy285);
+  }
+  yymsp[-1].minor.yy243 = p; /*A-overwrites-W*/
+}
         break;
-      case 114: /* select ::= select multiselect_op oneselect */
+      case 81: /* selectnowith ::= selectnowith multiselect_op oneselect */
 {
-  if( yymsp[0].minor.yy387 ){
-    yymsp[0].minor.yy387->op = (u8)yymsp[-1].minor.yy4;
-    yymsp[0].minor.yy387->pPrior = yymsp[-2].minor.yy387;
+  Select *pRhs = yymsp[0].minor.yy243;
+  Select *pLhs = yymsp[-2].minor.yy243;
+  if( pRhs && pRhs->pPrior ){
+    SrcList *pFrom;
+    Token x;
+    x.n = 0;
+    parserDoubleLinkSelect(pParse, pRhs);
+    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
+    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0,0);
+  }
+  if( pRhs ){
+    pRhs->op = (u8)yymsp[-1].minor.yy194;
+    pRhs->pPrior = pLhs;
+    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
+    pRhs->selFlags &= ~SF_MultiValue;
+    if( yymsp[-1].minor.yy194!=TK_ALL ) pParse->hasCompound = 1;
   }else{
-    sqlite3SelectDelete(pParse->db, yymsp[-2].minor.yy387);
+    sqlite3SelectDelete(pParse->db, pLhs);
   }
-  yygotominor.yy387 = yymsp[0].minor.yy387;
+  yymsp[-2].minor.yy243 = pRhs;
 }
         break;
-      case 116: /* multiselect_op ::= UNION ALL */
-{yygotominor.yy4 = TK_ALL;}
+      case 82: /* multiselect_op ::= UNION */
+      case 84: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==84);
+{yymsp[0].minor.yy194 = yymsp[0].major; /*A-overwrites-OP*/}
         break;
-      case 118: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */
+      case 83: /* multiselect_op ::= UNION ALL */
+{yymsp[-1].minor.yy194 = TK_ALL;}
+        break;
+      case 85: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */
 {
-  yygotominor.yy387 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy322,yymsp[-5].minor.yy259,yymsp[-4].minor.yy314,yymsp[-3].minor.yy322,yymsp[-2].minor.yy314,yymsp[-1].minor.yy322,yymsp[-7].minor.yy4,yymsp[0].minor.yy292.pLimit,yymsp[0].minor.yy292.pOffset);
+#if SELECTTRACE_ENABLED
+  Token s = yymsp[-8].minor.yy0; /*A-overwrites-S*/
+#endif
+  yymsp[-8].minor.yy243 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy148,yymsp[-5].minor.yy185,yymsp[-4].minor.yy72,yymsp[-3].minor.yy148,yymsp[-2].minor.yy72,yymsp[-1].minor.yy148,yymsp[-7].minor.yy194,yymsp[0].minor.yy354.pLimit,yymsp[0].minor.yy354.pOffset);
+#if SELECTTRACE_ENABLED
+  /* Populate the Select.zSelName[] string that is used to help with
+  ** query planner debugging, to differentiate between multiple Select
+  ** objects in a complex query.
+  **
+  ** If the SELECT keyword is immediately followed by a C-style comment
+  ** then extract the first few alphanumeric characters from within that
+  ** comment to be the zSelName value.  Otherwise, the label is #N where
+  ** is an integer that is incremented with each SELECT statement seen.
+  */
+  if( yymsp[-8].minor.yy243!=0 ){
+    const char *z = s.z+6;
+    int i;
+    sqlite3_snprintf(sizeof(yymsp[-8].minor.yy243->zSelName), yymsp[-8].minor.yy243->zSelName, "#%d",
+                     ++pParse->nSelect);
+    while( z[0]==' ' ) z++;
+    if( z[0]=='/' && z[1]=='*' ){
+      z += 2;
+      while( z[0]==' ' ) z++;
+      for(i=0; sqlite3Isalnum(z[i]); i++){}
+      sqlite3_snprintf(sizeof(yymsp[-8].minor.yy243->zSelName), yymsp[-8].minor.yy243->zSelName, "%.*s", i, z);
+    }
+  }
+#endif /* SELECTRACE_ENABLED */
 }
         break;
-      case 122: /* sclp ::= selcollist COMMA */
-      case 247: /* idxlist_opt ::= LP idxlist RP */ yytestcase(yyruleno==247);
-{yygotominor.yy322 = yymsp[-1].minor.yy322;}
+      case 86: /* values ::= VALUES LP nexprlist RP */
+{
+  yymsp[-3].minor.yy243 = sqlite3SelectNew(pParse,yymsp[-1].minor.yy148,0,0,0,0,0,SF_Values,0,0);
+}
         break;
-      case 123: /* sclp ::= */
-      case 151: /* orderby_opt ::= */ yytestcase(yyruleno==151);
-      case 159: /* groupby_opt ::= */ yytestcase(yyruleno==159);
-      case 240: /* exprlist ::= */ yytestcase(yyruleno==240);
-      case 246: /* idxlist_opt ::= */ yytestcase(yyruleno==246);
-{yygotominor.yy322 = 0;}
+      case 87: /* values ::= values COMMA LP exprlist RP */
+{
+  Select *pRight, *pLeft = yymsp[-4].minor.yy243;
+  pRight = sqlite3SelectNew(pParse,yymsp[-1].minor.yy148,0,0,0,0,0,SF_Values|SF_MultiValue,0,0);
+  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
+  if( pRight ){
+    pRight->op = TK_ALL;
+    pRight->pPrior = pLeft;
+    yymsp[-4].minor.yy243 = pRight;
+  }else{
+    yymsp[-4].minor.yy243 = pLeft;
+  }
+}
+        break;
+      case 88: /* distinct ::= DISTINCT */
+{yymsp[0].minor.yy194 = SF_Distinct;}
+        break;
+      case 89: /* distinct ::= ALL */
+{yymsp[0].minor.yy194 = SF_All;}
+        break;
+      case 91: /* sclp ::= */
+      case 119: /* orderby_opt ::= */ yytestcase(yyruleno==119);
+      case 126: /* groupby_opt ::= */ yytestcase(yyruleno==126);
+      case 199: /* exprlist ::= */ yytestcase(yyruleno==199);
+      case 202: /* paren_exprlist ::= */ yytestcase(yyruleno==202);
+      case 207: /* eidlist_opt ::= */ yytestcase(yyruleno==207);
+{yymsp[1].minor.yy148 = 0;}
         break;
-      case 124: /* selcollist ::= sclp expr as */
+      case 92: /* selcollist ::= sclp expr as */
 {
-   yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy322, yymsp[-1].minor.yy118.pExpr);
-   if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[0].minor.yy0, 1);
-   sqlite3ExprListSetSpan(pParse,yygotominor.yy322,&yymsp[-1].minor.yy118);
+   yymsp[-2].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy148, yymsp[-1].minor.yy190.pExpr);
+   if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yymsp[-2].minor.yy148, &yymsp[0].minor.yy0, 1);
+   sqlite3ExprListSetSpan(pParse,yymsp[-2].minor.yy148,&yymsp[-1].minor.yy190);
 }
         break;
-      case 125: /* selcollist ::= sclp STAR */
+      case 93: /* selcollist ::= sclp STAR */
 {
-  Expr *p = sqlite3Expr(pParse->db, TK_ALL, 0);
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-1].minor.yy322, p);
+  Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
+  yymsp[-1].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-1].minor.yy148, p);
 }
         break;
-      case 126: /* selcollist ::= sclp nm DOT STAR */
+      case 94: /* selcollist ::= sclp nm DOT STAR */
 {
-  Expr *pRight = sqlite3PExpr(pParse, TK_ALL, 0, 0, &yymsp[0].minor.yy0);
+  Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0, &yymsp[0].minor.yy0);
   Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
   Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy322, pDot);
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148, pDot);
 }
         break;
-      case 129: /* as ::= */
-{yygotominor.yy0.n = 0;}
+      case 95: /* as ::= AS nm */
+      case 106: /* dbnm ::= DOT nm */ yytestcase(yyruleno==106);
+      case 221: /* plus_num ::= PLUS INTEGER|FLOAT */ yytestcase(yyruleno==221);
+      case 222: /* minus_num ::= MINUS INTEGER|FLOAT */ yytestcase(yyruleno==222);
+{yymsp[-1].minor.yy0 = yymsp[0].minor.yy0;}
         break;
-      case 130: /* from ::= */
-{yygotominor.yy259 = sqlite3DbMallocZero(pParse->db, sizeof(*yygotominor.yy259));}
+      case 97: /* from ::= */
+{yymsp[1].minor.yy185 = sqlite3DbMallocZero(pParse->db, sizeof(*yymsp[1].minor.yy185));}
         break;
-      case 131: /* from ::= FROM seltablist */
+      case 98: /* from ::= FROM seltablist */
 {
-  yygotominor.yy259 = yymsp[0].minor.yy259;
-  sqlite3SrcListShiftJoinType(yygotominor.yy259);
+  yymsp[-1].minor.yy185 = yymsp[0].minor.yy185;
+  sqlite3SrcListShiftJoinType(yymsp[-1].minor.yy185);
 }
         break;
-      case 132: /* stl_prefix ::= seltablist joinop */
+      case 99: /* stl_prefix ::= seltablist joinop */
 {
-   yygotominor.yy259 = yymsp[-1].minor.yy259;
-   if( ALWAYS(yygotominor.yy259 && yygotominor.yy259->nSrc>0) ) yygotominor.yy259->a[yygotominor.yy259->nSrc-1].jointype = (u8)yymsp[0].minor.yy4;
+   if( ALWAYS(yymsp[-1].minor.yy185 && yymsp[-1].minor.yy185->nSrc>0) ) yymsp[-1].minor.yy185->a[yymsp[-1].minor.yy185->nSrc-1].fg.jointype = (u8)yymsp[0].minor.yy194;
 }
         break;
-      case 133: /* stl_prefix ::= */
-{yygotominor.yy259 = 0;}
+      case 100: /* stl_prefix ::= */
+{yymsp[1].minor.yy185 = 0;}
         break;
-      case 134: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */
+      case 101: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */
 {
-  yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
-  sqlite3SrcListIndexedBy(pParse, yygotominor.yy259, &yymsp[-2].minor.yy0);
+  yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-6].minor.yy185, &yymsp[-2].minor.yy0);
 }
         break;
-      case 135: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */
+      case 102: /* seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */
 {
-    yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy387,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+  yymsp[-8].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-8].minor.yy185,&yymsp[-7].minor.yy0,&yymsp[-6].minor.yy0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+  sqlite3SrcListFuncArgs(pParse, yymsp[-8].minor.yy185, yymsp[-4].minor.yy148);
+}
+        break;
+      case 103: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */
+{
+    yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy243,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
   }
         break;
-      case 136: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */
+      case 104: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */
 {
-    if( yymsp[-6].minor.yy259==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy314==0 && yymsp[0].minor.yy384==0 ){
-      yygotominor.yy259 = yymsp[-4].minor.yy259;
+    if( yymsp[-6].minor.yy185==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy72==0 && yymsp[0].minor.yy254==0 ){
+      yymsp[-6].minor.yy185 = yymsp[-4].minor.yy185;
+    }else if( yymsp[-4].minor.yy185->nSrc==1 ){
+      yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
+      if( yymsp[-6].minor.yy185 ){
+        struct SrcList_item *pNew = &yymsp[-6].minor.yy185->a[yymsp[-6].minor.yy185->nSrc-1];
+        struct SrcList_item *pOld = yymsp[-4].minor.yy185->a;
+        pNew->zName = pOld->zName;
+        pNew->zDatabase = pOld->zDatabase;
+        pNew->pSelect = pOld->pSelect;
+        pOld->zName = pOld->zDatabase = 0;
+        pOld->pSelect = 0;
+      }
+      sqlite3SrcListDelete(pParse->db, yymsp[-4].minor.yy185);
     }else{
       Select *pSubquery;
-      sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy259);
-      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy259,0,0,0,0,0,0,0);
-      yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+      sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy185);
+      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy185,0,0,0,0,SF_NestedFrom,0,0);
+      yymsp[-6].minor.yy185 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy185,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy72,yymsp[0].minor.yy254);
     }
   }
         break;
-      case 137: /* dbnm ::= */
-      case 146: /* indexed_opt ::= */ yytestcase(yyruleno==146);
-{yygotominor.yy0.z=0; yygotominor.yy0.n=0;}
+      case 105: /* dbnm ::= */
+      case 114: /* indexed_opt ::= */ yytestcase(yyruleno==114);
+{yymsp[1].minor.yy0.z=0; yymsp[1].minor.yy0.n=0;}
+        break;
+      case 107: /* fullname ::= nm dbnm */
+{yymsp[-1].minor.yy185 = sqlite3SrcListAppend(pParse->db,0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/}
         break;
-      case 139: /* fullname ::= nm dbnm */
-{yygotominor.yy259 = sqlite3SrcListAppend(pParse->db,0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}
+      case 108: /* joinop ::= COMMA|JOIN */
+{ yymsp[0].minor.yy194 = JT_INNER; }
         break;
-      case 140: /* joinop ::= COMMA|JOIN */
-{ yygotominor.yy4 = JT_INNER; }
+      case 109: /* joinop ::= JOIN_KW JOIN */
+{yymsp[-1].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0);  /*X-overwrites-A*/}
         break;
-      case 141: /* joinop ::= JOIN_KW JOIN */
-{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0); }
+      case 110: /* joinop ::= JOIN_KW nm JOIN */
+{yymsp[-2].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); /*X-overwrites-A*/}
         break;
-      case 142: /* joinop ::= JOIN_KW nm JOIN */
-{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); }
+      case 111: /* joinop ::= JOIN_KW nm nm JOIN */
+{yymsp[-3].minor.yy194 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);/*X-overwrites-A*/}
         break;
-      case 143: /* joinop ::= JOIN_KW nm nm JOIN */
-{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0); }
+      case 112: /* on_opt ::= ON expr */
+      case 129: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==129);
+      case 136: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==136);
+      case 195: /* case_else ::= ELSE expr */ yytestcase(yyruleno==195);
+{yymsp[-1].minor.yy72 = yymsp[0].minor.yy190.pExpr;}
         break;
-      case 144: /* on_opt ::= ON expr */
-      case 155: /* sortitem ::= expr */ yytestcase(yyruleno==155);
-      case 162: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==162);
-      case 169: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==169);
-      case 235: /* case_else ::= ELSE expr */ yytestcase(yyruleno==235);
-      case 237: /* case_operand ::= expr */ yytestcase(yyruleno==237);
-{yygotominor.yy314 = yymsp[0].minor.yy118.pExpr;}
+      case 113: /* on_opt ::= */
+      case 128: /* having_opt ::= */ yytestcase(yyruleno==128);
+      case 135: /* where_opt ::= */ yytestcase(yyruleno==135);
+      case 196: /* case_else ::= */ yytestcase(yyruleno==196);
+      case 198: /* case_operand ::= */ yytestcase(yyruleno==198);
+{yymsp[1].minor.yy72 = 0;}
         break;
-      case 145: /* on_opt ::= */
-      case 161: /* having_opt ::= */ yytestcase(yyruleno==161);
-      case 168: /* where_opt ::= */ yytestcase(yyruleno==168);
-      case 236: /* case_else ::= */ yytestcase(yyruleno==236);
-      case 238: /* case_operand ::= */ yytestcase(yyruleno==238);
-{yygotominor.yy314 = 0;}
+      case 115: /* indexed_opt ::= INDEXED BY nm */
+{yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;}
         break;
-      case 148: /* indexed_opt ::= NOT INDEXED */
-{yygotominor.yy0.z=0; yygotominor.yy0.n=1;}
+      case 116: /* indexed_opt ::= NOT INDEXED */
+{yymsp[-1].minor.yy0.z=0; yymsp[-1].minor.yy0.n=1;}
         break;
-      case 149: /* using_opt ::= USING LP inscollist RP */
-      case 181: /* inscollist_opt ::= LP inscollist RP */ yytestcase(yyruleno==181);
-{yygotominor.yy384 = yymsp[-1].minor.yy384;}
+      case 117: /* using_opt ::= USING LP idlist RP */
+{yymsp[-3].minor.yy254 = yymsp[-1].minor.yy254;}
         break;
-      case 150: /* using_opt ::= */
-      case 180: /* inscollist_opt ::= */ yytestcase(yyruleno==180);
-{yygotominor.yy384 = 0;}
+      case 118: /* using_opt ::= */
+      case 144: /* idlist_opt ::= */ yytestcase(yyruleno==144);
+{yymsp[1].minor.yy254 = 0;}
         break;
-      case 152: /* orderby_opt ::= ORDER BY sortlist */
-      case 160: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==160);
-      case 239: /* exprlist ::= nexprlist */ yytestcase(yyruleno==239);
-{yygotominor.yy322 = yymsp[0].minor.yy322;}
+      case 120: /* orderby_opt ::= ORDER BY sortlist */
+      case 127: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==127);
+{yymsp[-2].minor.yy148 = yymsp[0].minor.yy148;}
         break;
-      case 153: /* sortlist ::= sortlist COMMA sortitem sortorder */
+      case 121: /* sortlist ::= sortlist COMMA expr sortorder */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy322,yymsp[-1].minor.yy314);
-  if( yygotominor.yy322 ) yygotominor.yy322->a[yygotominor.yy322->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy4;
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148,yymsp[-1].minor.yy190.pExpr);
+  sqlite3ExprListSetSortOrder(yymsp[-3].minor.yy148,yymsp[0].minor.yy194);
 }
         break;
-      case 154: /* sortlist ::= sortitem sortorder */
+      case 122: /* sortlist ::= expr sortorder */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy314);
-  if( yygotominor.yy322 && ALWAYS(yygotominor.yy322->a) ) yygotominor.yy322->a[0].sortOrder = (u8)yymsp[0].minor.yy4;
+  yymsp[-1].minor.yy148 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy190.pExpr); /*A-overwrites-Y*/
+  sqlite3ExprListSetSortOrder(yymsp[-1].minor.yy148,yymsp[0].minor.yy194);
 }
         break;
-      case 156: /* sortorder ::= ASC */
-      case 158: /* sortorder ::= */ yytestcase(yyruleno==158);
-{yygotominor.yy4 = SQLITE_SO_ASC;}
+      case 123: /* sortorder ::= ASC */
+{yymsp[0].minor.yy194 = SQLITE_SO_ASC;}
         break;
-      case 157: /* sortorder ::= DESC */
-{yygotominor.yy4 = SQLITE_SO_DESC;}
+      case 124: /* sortorder ::= DESC */
+{yymsp[0].minor.yy194 = SQLITE_SO_DESC;}
         break;
-      case 163: /* limit_opt ::= */
-{yygotominor.yy292.pLimit = 0; yygotominor.yy292.pOffset = 0;}
+      case 125: /* sortorder ::= */
+{yymsp[1].minor.yy194 = SQLITE_SO_UNDEFINED;}
         break;
-      case 164: /* limit_opt ::= LIMIT expr */
-{yygotominor.yy292.pLimit = yymsp[0].minor.yy118.pExpr; yygotominor.yy292.pOffset = 0;}
+      case 130: /* limit_opt ::= */
+{yymsp[1].minor.yy354.pLimit = 0; yymsp[1].minor.yy354.pOffset = 0;}
         break;
-      case 165: /* limit_opt ::= LIMIT expr OFFSET expr */
-{yygotominor.yy292.pLimit = yymsp[-2].minor.yy118.pExpr; yygotominor.yy292.pOffset = yymsp[0].minor.yy118.pExpr;}
+      case 131: /* limit_opt ::= LIMIT expr */
+{yymsp[-1].minor.yy354.pLimit = yymsp[0].minor.yy190.pExpr; yymsp[-1].minor.yy354.pOffset = 0;}
         break;
-      case 166: /* limit_opt ::= LIMIT expr COMMA expr */
-{yygotominor.yy292.pOffset = yymsp[-2].minor.yy118.pExpr; yygotominor.yy292.pLimit = yymsp[0].minor.yy118.pExpr;}
+      case 132: /* limit_opt ::= LIMIT expr OFFSET expr */
+{yymsp[-3].minor.yy354.pLimit = yymsp[-2].minor.yy190.pExpr; yymsp[-3].minor.yy354.pOffset = yymsp[0].minor.yy190.pExpr;}
         break;
-      case 167: /* cmd ::= DELETE FROM fullname indexed_opt where_opt */
+      case 133: /* limit_opt ::= LIMIT expr COMMA expr */
+{yymsp[-3].minor.yy354.pOffset = yymsp[-2].minor.yy190.pExpr; yymsp[-3].minor.yy354.pLimit = yymsp[0].minor.yy190.pExpr;}
+        break;
+      case 134: /* cmd ::= with DELETE FROM fullname indexed_opt where_opt */
 {
-  sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy259, &yymsp[-1].minor.yy0);
-  sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy259,yymsp[0].minor.yy314);
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy285, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy185, &yymsp[-1].minor.yy0);
+  sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy185,yymsp[0].minor.yy72);
 }
         break;
-      case 170: /* cmd ::= UPDATE orconf fullname indexed_opt SET setlist where_opt */
+      case 137: /* cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt */
 {
-  sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy259, &yymsp[-3].minor.yy0);
-  sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy322,"set list"); 
-  sqlite3Update(pParse,yymsp[-4].minor.yy259,yymsp[-1].minor.yy322,yymsp[0].minor.yy314,yymsp[-5].minor.yy210);
+  sqlite3WithPush(pParse, yymsp[-7].minor.yy285, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy185, &yymsp[-3].minor.yy0);
+  sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy148,"set list"); 
+  sqlite3Update(pParse,yymsp[-4].minor.yy185,yymsp[-1].minor.yy148,yymsp[0].minor.yy72,yymsp[-5].minor.yy194);
 }
         break;
-      case 171: /* setlist ::= setlist COMMA nm EQ expr */
+      case 138: /* setlist ::= setlist COMMA nm EQ expr */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy322, yymsp[0].minor.yy118.pExpr);
-  sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[-2].minor.yy0, 1);
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy148, yymsp[0].minor.yy190.pExpr);
+  sqlite3ExprListSetName(pParse, yymsp[-4].minor.yy148, &yymsp[-2].minor.yy0, 1);
 }
         break;
-      case 172: /* setlist ::= nm EQ expr */
+      case 139: /* setlist ::= nm EQ expr */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy118.pExpr);
-  sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[-2].minor.yy0, 1);
+  yylhsminor.yy148 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy190.pExpr);
+  sqlite3ExprListSetName(pParse, yylhsminor.yy148, &yymsp[-2].minor.yy0, 1);
 }
+  yymsp[-2].minor.yy148 = yylhsminor.yy148;
         break;
-      case 173: /* cmd ::= insert_cmd INTO fullname inscollist_opt VALUES LP itemlist RP */
-{sqlite3Insert(pParse, yymsp[-5].minor.yy259, yymsp[-1].minor.yy322, 0, yymsp[-4].minor.yy384, yymsp[-7].minor.yy210);}
-        break;
-      case 174: /* cmd ::= insert_cmd INTO fullname inscollist_opt select */
-{sqlite3Insert(pParse, yymsp[-2].minor.yy259, 0, yymsp[0].minor.yy387, yymsp[-1].minor.yy384, yymsp[-4].minor.yy210);}
-        break;
-      case 175: /* cmd ::= insert_cmd INTO fullname inscollist_opt DEFAULT VALUES */
-{sqlite3Insert(pParse, yymsp[-3].minor.yy259, 0, 0, yymsp[-2].minor.yy384, yymsp[-5].minor.yy210);}
-        break;
-      case 176: /* insert_cmd ::= INSERT orconf */
-{yygotominor.yy210 = yymsp[0].minor.yy210;}
-        break;
-      case 177: /* insert_cmd ::= REPLACE */
-{yygotominor.yy210 = OE_Replace;}
-        break;
-      case 178: /* itemlist ::= itemlist COMMA expr */
-      case 241: /* nexprlist ::= nexprlist COMMA expr */ yytestcase(yyruleno==241);
-{yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy322,yymsp[0].minor.yy118.pExpr);}
+      case 140: /* cmd ::= with insert_cmd INTO fullname idlist_opt select */
+{
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy285, 1);
+  sqlite3Insert(pParse, yymsp[-2].minor.yy185, yymsp[0].minor.yy243, yymsp[-1].minor.yy254, yymsp[-4].minor.yy194);
+}
         break;
-      case 179: /* itemlist ::= expr */
-      case 242: /* nexprlist ::= expr */ yytestcase(yyruleno==242);
-{yygotominor.yy322 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy118.pExpr);}
+      case 141: /* cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES */
+{
+  sqlite3WithPush(pParse, yymsp[-6].minor.yy285, 1);
+  sqlite3Insert(pParse, yymsp[-3].minor.yy185, 0, yymsp[-2].minor.yy254, yymsp[-5].minor.yy194);
+}
         break;
-      case 182: /* inscollist ::= inscollist COMMA nm */
-{yygotominor.yy384 = sqlite3IdListAppend(pParse->db,yymsp[-2].minor.yy384,&yymsp[0].minor.yy0);}
+      case 145: /* idlist_opt ::= LP idlist RP */
+{yymsp[-2].minor.yy254 = yymsp[-1].minor.yy254;}
         break;
-      case 183: /* inscollist ::= nm */
-{yygotominor.yy384 = sqlite3IdListAppend(pParse->db,0,&yymsp[0].minor.yy0);}
+      case 146: /* idlist ::= idlist COMMA nm */
+{yymsp[-2].minor.yy254 = sqlite3IdListAppend(pParse->db,yymsp[-2].minor.yy254,&yymsp[0].minor.yy0);}
         break;
-      case 184: /* expr ::= term */
-{yygotominor.yy118 = yymsp[0].minor.yy118;}
+      case 147: /* idlist ::= nm */
+{yymsp[0].minor.yy254 = sqlite3IdListAppend(pParse->db,0,&yymsp[0].minor.yy0); /*A-overwrites-Y*/}
         break;
-      case 185: /* expr ::= LP expr RP */
-{yygotominor.yy118.pExpr = yymsp[-1].minor.yy118.pExpr; spanSet(&yygotominor.yy118,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);}
+      case 148: /* expr ::= LP expr RP */
+{spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/  yymsp[-2].minor.yy190.pExpr = yymsp[-1].minor.yy190.pExpr;}
         break;
-      case 186: /* term ::= NULL */
-      case 191: /* term ::= INTEGER|FLOAT|BLOB */ yytestcase(yyruleno==191);
-      case 192: /* term ::= STRING */ yytestcase(yyruleno==192);
-{spanExpr(&yygotominor.yy118, pParse, yymsp[0].major, &yymsp[0].minor.yy0);}
+      case 149: /* term ::= NULL */
+      case 154: /* term ::= INTEGER|FLOAT|BLOB */ yytestcase(yyruleno==154);
+      case 155: /* term ::= STRING */ yytestcase(yyruleno==155);
+{spanExpr(&yymsp[0].minor.yy190,pParse,yymsp[0].major,yymsp[0].minor.yy0);/*A-overwrites-X*/}
         break;
-      case 187: /* expr ::= id */
-      case 188: /* expr ::= JOIN_KW */ yytestcase(yyruleno==188);
-{spanExpr(&yygotominor.yy118, pParse, TK_ID, &yymsp[0].minor.yy0);}
+      case 150: /* expr ::= ID|INDEXED */
+      case 151: /* expr ::= JOIN_KW */ yytestcase(yyruleno==151);
+{spanExpr(&yymsp[0].minor.yy190,pParse,TK_ID,yymsp[0].minor.yy0); /*A-overwrites-X*/}
         break;
-      case 189: /* expr ::= nm DOT nm */
+      case 152: /* expr ::= nm DOT nm */
 {
   Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
   Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp2, 0);
-  spanSet(&yygotominor.yy118,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);
+  spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-2].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp2, 0);
 }
         break;
-      case 190: /* expr ::= nm DOT nm DOT nm */
+      case 153: /* expr ::= nm DOT nm DOT nm */
 {
   Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-4].minor.yy0);
   Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
   Expr *temp3 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
   Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0);
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
-  spanSet(&yygotominor.yy118,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
+  spanSet(&yymsp[-4].minor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
 }
         break;
-      case 193: /* expr ::= REGISTER */
+      case 156: /* expr ::= VARIABLE */
 {
-  /* When doing a nested parse, one can include terms in an expression
-  ** that look like this:   #1 #2 ...  These terms refer to registers
-  ** in the virtual machine.  #N is the N-th register. */
-  if( pParse->nested==0 ){
-    sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &yymsp[0].minor.yy0);
-    yygotominor.yy118.pExpr = 0;
+  if( !(yymsp[0].minor.yy0.z[0]=='#' && sqlite3Isdigit(yymsp[0].minor.yy0.z[1])) ){
+    spanExpr(&yymsp[0].minor.yy190, pParse, TK_VARIABLE, yymsp[0].minor.yy0);
+    sqlite3ExprAssignVarNumber(pParse, yymsp[0].minor.yy190.pExpr);
   }else{
-    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, &yymsp[0].minor.yy0);
-    if( yygotominor.yy118.pExpr ) sqlite3GetInt32(&yymsp[0].minor.yy0.z[1], &yygotominor.yy118.pExpr->iTable);
+    /* When doing a nested parse, one can include terms in an expression
+    ** that look like this:   #1 #2 ...  These terms refer to registers
+    ** in the virtual machine.  #N is the N-th register. */
+    Token t = yymsp[0].minor.yy0; /*A-overwrites-X*/
+    assert( t.n>=2 );
+    spanSet(&yymsp[0].minor.yy190, &t, &t);
+    if( pParse->nested==0 ){
+      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);
+      yymsp[0].minor.yy190.pExpr = 0;
+    }else{
+      yymsp[0].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, &t);
+      if( yymsp[0].minor.yy190.pExpr ) sqlite3GetInt32(&t.z[1], &yymsp[0].minor.yy190.pExpr->iTable);
+    }
   }
-  spanSet(&yygotominor.yy118, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
 }
         break;
-      case 194: /* expr ::= VARIABLE */
+      case 157: /* expr ::= expr COLLATE ID|STRING */
 {
-  spanExpr(&yygotominor.yy118, pParse, TK_VARIABLE, &yymsp[0].minor.yy0);
-  sqlite3ExprAssignVarNumber(pParse, yygotominor.yy118.pExpr);
-  spanSet(&yygotominor.yy118, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
+  yymsp[-2].minor.yy190.pExpr = sqlite3ExprAddCollateToken(pParse, yymsp[-2].minor.yy190.pExpr, &yymsp[0].minor.yy0, 1);
+  yymsp[-2].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
 }
         break;
-      case 195: /* expr ::= expr COLLATE ids */
+      case 158: /* expr ::= CAST LP expr AS typetoken RP */
 {
-  yygotominor.yy118.pExpr = sqlite3ExprSetCollByToken(pParse, yymsp[-2].minor.yy118.pExpr, &yymsp[0].minor.yy0);
-  yygotominor.yy118.zStart = yymsp[-2].minor.yy118.zStart;
-  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  spanSet(&yymsp[-5].minor.yy190,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/
+  yymsp[-5].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_CAST, yymsp[-3].minor.yy190.pExpr, 0, &yymsp[-1].minor.yy0);
 }
         break;
-      case 196: /* expr ::= CAST LP expr AS typetoken RP */
+      case 159: /* expr ::= ID|INDEXED LP distinct exprlist RP */
 {
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_CAST, yymsp[-3].minor.yy118.pExpr, 0, &yymsp[-1].minor.yy0);
-  spanSet(&yygotominor.yy118,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0);
-}
-        break;
-      case 197: /* expr ::= ID LP distinct exprlist RP */
-{
-  if( yymsp[-1].minor.yy322 && yymsp[-1].minor.yy322->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
+  if( yymsp[-1].minor.yy148 && yymsp[-1].minor.yy148->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
     sqlite3ErrorMsg(pParse, "too many arguments on function %T", &yymsp[-4].minor.yy0);
   }
-  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy322, &yymsp[-4].minor.yy0);
-  spanSet(&yygotominor.yy118,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
-  if( yymsp[-2].minor.yy4 && yygotominor.yy118.pExpr ){
-    yygotominor.yy118.pExpr->flags |= EP_Distinct;
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy148, &yymsp[-4].minor.yy0);
+  spanSet(&yylhsminor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
+  if( yymsp[-2].minor.yy194==SF_Distinct && yylhsminor.yy190.pExpr ){
+    yylhsminor.yy190.pExpr->flags |= EP_Distinct;
   }
 }
+  yymsp[-4].minor.yy190 = yylhsminor.yy190;
         break;
-      case 198: /* expr ::= ID LP STAR RP */
+      case 160: /* expr ::= ID|INDEXED LP STAR RP */
 {
-  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0);
-  spanSet(&yygotominor.yy118,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0);
+  spanSet(&yylhsminor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);
 }
+  yymsp[-3].minor.yy190 = yylhsminor.yy190;
         break;
-      case 199: /* term ::= CTIME_KW */
+      case 161: /* term ::= CTIME_KW */
 {
-  /* The CURRENT_TIME, CURRENT_DATE, and CURRENT_TIMESTAMP values are
-  ** treated as functions that return constants */
-  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, 0,&yymsp[0].minor.yy0);
-  if( yygotominor.yy118.pExpr ){
-    yygotominor.yy118.pExpr->op = TK_CONST_FUNC;  
-  }
-  spanSet(&yygotominor.yy118, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
+  yylhsminor.yy190.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[0].minor.yy0);
+  spanSet(&yylhsminor.yy190, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
 }
+  yymsp[0].minor.yy190 = yylhsminor.yy190;
         break;
-      case 200: /* expr ::= expr AND expr */
-      case 201: /* expr ::= expr OR expr */ yytestcase(yyruleno==201);
-      case 202: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==202);
-      case 203: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==203);
-      case 204: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==204);
-      case 205: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==205);
-      case 206: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==206);
-      case 207: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==207);
-{spanBinaryExpr(&yygotominor.yy118,pParse,yymsp[-1].major,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy118);}
+      case 162: /* expr ::= expr AND expr */
+      case 163: /* expr ::= expr OR expr */ yytestcase(yyruleno==163);
+      case 164: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==164);
+      case 165: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==165);
+      case 166: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==166);
+      case 167: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==167);
+      case 168: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==168);
+      case 169: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==169);
+{spanBinaryExpr(pParse,yymsp[-1].major,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy190);}
         break;
-      case 208: /* likeop ::= LIKE_KW */
-      case 210: /* likeop ::= MATCH */ yytestcase(yyruleno==210);
-{yygotominor.yy342.eOperator = yymsp[0].minor.yy0; yygotominor.yy342.not = 0;}
+      case 170: /* likeop ::= LIKE_KW|MATCH */
+{yymsp[0].minor.yy392.eOperator = yymsp[0].minor.yy0; yymsp[0].minor.yy392.bNot = 0;/*A-overwrites-X*/}
         break;
-      case 209: /* likeop ::= NOT LIKE_KW */
-      case 211: /* likeop ::= NOT MATCH */ yytestcase(yyruleno==211);
-{yygotominor.yy342.eOperator = yymsp[0].minor.yy0; yygotominor.yy342.not = 1;}
+      case 171: /* likeop ::= NOT LIKE_KW|MATCH */
+{yymsp[-1].minor.yy392.eOperator = yymsp[0].minor.yy0; yymsp[-1].minor.yy392.bNot = 1;}
         break;
-      case 212: /* expr ::= expr likeop expr */
+      case 172: /* expr ::= expr likeop expr */
 {
   ExprList *pList;
-  pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy118.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy118.pExpr);
-  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy342.eOperator);
-  if( yymsp[-1].minor.yy342.not ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
-  yygotominor.yy118.zStart = yymsp[-2].minor.yy118.zStart;
-  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
-  if( yygotominor.yy118.pExpr ) yygotominor.yy118.pExpr->flags |= EP_InfixFunc;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-2].minor.yy190.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy392.eOperator);
+  exprNot(pParse, yymsp[-1].minor.yy392.bNot, &yymsp[-2].minor.yy190);
+  yymsp[-2].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
+  if( yymsp[-2].minor.yy190.pExpr ) yymsp[-2].minor.yy190.pExpr->flags |= EP_InfixFunc;
 }
         break;
-      case 213: /* expr ::= expr likeop expr ESCAPE expr */
+      case 173: /* expr ::= expr likeop expr ESCAPE expr */
 {
   ExprList *pList;
-  pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy118.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy118.pExpr);
-  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy342.eOperator);
-  if( yymsp[-3].minor.yy342.not ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
-  yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
-  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
-  if( yygotominor.yy118.pExpr ) yygotominor.yy118.pExpr->flags |= EP_InfixFunc;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy190.pExpr);
+  yymsp[-4].minor.yy190.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy392.eOperator);
+  exprNot(pParse, yymsp[-3].minor.yy392.bNot, &yymsp[-4].minor.yy190);
+  yymsp[-4].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
+  if( yymsp[-4].minor.yy190.pExpr ) yymsp[-4].minor.yy190.pExpr->flags |= EP_InfixFunc;
 }
         break;
-      case 214: /* expr ::= expr ISNULL|NOTNULL */
-{spanUnaryPostfix(&yygotominor.yy118,pParse,yymsp[0].major,&yymsp[-1].minor.yy118,&yymsp[0].minor.yy0);}
+      case 174: /* expr ::= expr ISNULL|NOTNULL */
+{spanUnaryPostfix(pParse,yymsp[0].major,&yymsp[-1].minor.yy190,&yymsp[0].minor.yy0);}
         break;
-      case 215: /* expr ::= expr NOT NULL */
-{spanUnaryPostfix(&yygotominor.yy118,pParse,TK_NOTNULL,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy0);}
+      case 175: /* expr ::= expr NOT NULL */
+{spanUnaryPostfix(pParse,TK_NOTNULL,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy0);}
         break;
-      case 216: /* expr ::= expr IS expr */
+      case 176: /* expr ::= expr IS expr */
 {
-  spanBinaryExpr(&yygotominor.yy118,pParse,TK_IS,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy118);
-  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy118.pExpr, yygotominor.yy118.pExpr, TK_ISNULL);
+  spanBinaryExpr(pParse,TK_IS,&yymsp[-2].minor.yy190,&yymsp[0].minor.yy190);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy190.pExpr, yymsp[-2].minor.yy190.pExpr, TK_ISNULL);
 }
         break;
-      case 217: /* expr ::= expr IS NOT expr */
+      case 177: /* expr ::= expr IS NOT expr */
 {
-  spanBinaryExpr(&yygotominor.yy118,pParse,TK_ISNOT,&yymsp[-3].minor.yy118,&yymsp[0].minor.yy118);
-  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy118.pExpr, yygotominor.yy118.pExpr, TK_NOTNULL);
+  spanBinaryExpr(pParse,TK_ISNOT,&yymsp[-3].minor.yy190,&yymsp[0].minor.yy190);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy190.pExpr, yymsp[-3].minor.yy190.pExpr, TK_NOTNULL);
 }
         break;
-      case 218: /* expr ::= NOT expr */
-      case 219: /* expr ::= BITNOT expr */ yytestcase(yyruleno==219);
-{spanUnaryPrefix(&yygotominor.yy118,pParse,yymsp[-1].major,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+      case 178: /* expr ::= NOT expr */
+      case 179: /* expr ::= BITNOT expr */ yytestcase(yyruleno==179);
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,yymsp[-1].major,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
         break;
-      case 220: /* expr ::= MINUS expr */
-{spanUnaryPrefix(&yygotominor.yy118,pParse,TK_UMINUS,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+      case 180: /* expr ::= MINUS expr */
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,TK_UMINUS,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
         break;
-      case 221: /* expr ::= PLUS expr */
-{spanUnaryPrefix(&yygotominor.yy118,pParse,TK_UPLUS,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+      case 181: /* expr ::= PLUS expr */
+{spanUnaryPrefix(&yymsp[-1].minor.yy190,pParse,TK_UPLUS,&yymsp[0].minor.yy190,&yymsp[-1].minor.yy0);/*A-overwrites-B*/}
         break;
-      case 224: /* expr ::= expr between_op expr AND expr */
+      case 182: /* between_op ::= BETWEEN */
+      case 185: /* in_op ::= IN */ yytestcase(yyruleno==185);
+{yymsp[0].minor.yy194 = 0;}
+        break;
+      case 184: /* expr ::= expr between_op expr AND expr */
 {
-  ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
-  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy118.pExpr);
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy118.pExpr, 0, 0);
-  if( yygotominor.yy118.pExpr ){
-    yygotominor.yy118.pExpr->x.pList = pList;
+  ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy190.pExpr);
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy190.pExpr, 0, 0);
+  if( yymsp[-4].minor.yy190.pExpr ){
+    yymsp[-4].minor.yy190.pExpr->x.pList = pList;
   }else{
     sqlite3ExprListDelete(pParse->db, pList);
   } 
-  if( yymsp[-3].minor.yy4 ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
-  yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
-  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
+  exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+  yymsp[-4].minor.yy190.zEnd = yymsp[0].minor.yy190.zEnd;
 }
         break;
-      case 227: /* expr ::= expr in_op LP exprlist RP */
+      case 187: /* expr ::= expr in_op LP exprlist RP */
 {
-    if( yymsp[-1].minor.yy322==0 ){
+    if( yymsp[-1].minor.yy148==0 ){
       /* Expressions of the form
       **
       **      expr1 IN ()
@@ -108714,416 +134539,436 @@ static void yy_reduce(
       ** simplify to constants 0 (false) and 1 (true), respectively,
       ** regardless of the value of expr1.
       */
-      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &sqlite3IntTokens[yymsp[-3].minor.yy4]);
-      sqlite3ExprDelete(pParse->db, yymsp[-4].minor.yy118.pExpr);
+      sqlite3ExprDelete(pParse->db, yymsp[-4].minor.yy190.pExpr);
+      yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &sqlite3IntTokens[yymsp[-3].minor.yy194]);
+    }else if( yymsp[-1].minor.yy148->nExpr==1 ){
+      /* Expressions of the form:
+      **
+      **      expr1 IN (?1)
+      **      expr1 NOT IN (?2)
+      **
+      ** with exactly one value on the RHS can be simplified to something
+      ** like this:
+      **
+      **      expr1 == ?1
+      **      expr1 <> ?2
+      **
+      ** But, the RHS of the == or <> is marked with the EP_Generic flag
+      ** so that it may not contribute to the computation of comparison
+      ** affinity or the collating sequence to use for comparison.  Otherwise,
+      ** the semantics would be subtly different from IN or NOT IN.
+      */
+      Expr *pRHS = yymsp[-1].minor.yy148->a[0].pExpr;
+      yymsp[-1].minor.yy148->a[0].pExpr = 0;
+      sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy148);
+      /* pRHS cannot be NULL because a malloc error would have been detected
+      ** before now and control would have never reached this point */
+      if( ALWAYS(pRHS) ){
+        pRHS->flags &= ~EP_Collate;
+        pRHS->flags |= EP_Generic;
+      }
+      yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, yymsp[-3].minor.yy194 ? TK_NE : TK_EQ, yymsp[-4].minor.yy190.pExpr, pRHS, 0);
     }else{
-      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy118.pExpr, 0, 0);
-      if( yygotominor.yy118.pExpr ){
-        yygotominor.yy118.pExpr->x.pList = yymsp[-1].minor.yy322;
-        sqlite3ExprSetHeight(pParse, yygotominor.yy118.pExpr);
+      yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0, 0);
+      if( yymsp[-4].minor.yy190.pExpr ){
+        yymsp[-4].minor.yy190.pExpr->x.pList = yymsp[-1].minor.yy148;
+        sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy190.pExpr);
       }else{
-        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy322);
+        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy148);
       }
-      if( yymsp[-3].minor.yy4 ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
+      exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
     }
-    yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
-    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+    yymsp[-4].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
   }
         break;
-      case 228: /* expr ::= LP select RP */
+      case 188: /* expr ::= LP select RP */
 {
-    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
-    if( yygotominor.yy118.pExpr ){
-      yygotominor.yy118.pExpr->x.pSelect = yymsp[-1].minor.yy387;
-      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy118.pExpr);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
-    }
-    yygotominor.yy118.zStart = yymsp[-2].minor.yy0.z;
-    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+    spanSet(&yymsp[-2].minor.yy190,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/
+    yymsp[-2].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-2].minor.yy190.pExpr, yymsp[-1].minor.yy243);
   }
         break;
-      case 229: /* expr ::= expr in_op LP select RP */
+      case 189: /* expr ::= expr in_op LP select RP */
 {
-    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy118.pExpr, 0, 0);
-    if( yygotominor.yy118.pExpr ){
-      yygotominor.yy118.pExpr->x.pSelect = yymsp[-1].minor.yy387;
-      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy118.pExpr);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
-    }
-    if( yymsp[-3].minor.yy4 ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
-    yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
-    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+    yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy190.pExpr, yymsp[-1].minor.yy243);
+    exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+    yymsp[-4].minor.yy190.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
   }
         break;
-      case 230: /* expr ::= expr in_op nm dbnm */
+      case 190: /* expr ::= expr in_op nm dbnm paren_exprlist */
 {
-    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);
-    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-3].minor.yy118.pExpr, 0, 0);
-    if( yygotominor.yy118.pExpr ){
-      yygotominor.yy118.pExpr->x.pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
-      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, yygotominor.yy118.pExpr);
-    }else{
-      sqlite3SrcListDelete(pParse->db, pSrc);
-    }
-    if( yymsp[-2].minor.yy4 ) yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_NOT, yygotominor.yy118.pExpr, 0, 0);
-    yygotominor.yy118.zStart = yymsp[-3].minor.yy118.zStart;
-    yygotominor.yy118.zEnd = yymsp[0].minor.yy0.z ? &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] : &yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n];
+    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);
+    Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
+    if( yymsp[0].minor.yy148 )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, yymsp[0].minor.yy148);
+    yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy190.pExpr, 0, 0);
+    sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy190.pExpr, pSelect);
+    exprNot(pParse, yymsp[-3].minor.yy194, &yymsp[-4].minor.yy190);
+    yymsp[-4].minor.yy190.zEnd = yymsp[-1].minor.yy0.z ? &yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n] : &yymsp[-2].minor.yy0.z[yymsp[-2].minor.yy0.n];
   }
         break;
-      case 231: /* expr ::= EXISTS LP select RP */
+      case 191: /* expr ::= EXISTS LP select RP */
 {
-    Expr *p = yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
-    if( p ){
-      p->x.pSelect = yymsp[-1].minor.yy387;
-      ExprSetProperty(p, EP_xIsSelect);
-      sqlite3ExprSetHeight(pParse, p);
-    }else{
-      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
-    }
-    yygotominor.yy118.zStart = yymsp[-3].minor.yy0.z;
-    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+    Expr *p;
+    spanSet(&yymsp[-3].minor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-B*/
+    p = yymsp[-3].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
+    sqlite3PExprAddSelect(pParse, p, yymsp[-1].minor.yy243);
   }
         break;
-      case 232: /* expr ::= CASE case_operand case_exprlist case_else END */
+      case 192: /* expr ::= CASE case_operand case_exprlist case_else END */
 {
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy314, yymsp[-1].minor.yy314, 0);
-  if( yygotominor.yy118.pExpr ){
-    yygotominor.yy118.pExpr->x.pList = yymsp[-2].minor.yy322;
-    sqlite3ExprSetHeight(pParse, yygotominor.yy118.pExpr);
+  spanSet(&yymsp[-4].minor.yy190,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-C*/
+  yymsp[-4].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy72, 0, 0);
+  if( yymsp[-4].minor.yy190.pExpr ){
+    yymsp[-4].minor.yy190.pExpr->x.pList = yymsp[-1].minor.yy72 ? sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy148,yymsp[-1].minor.yy72) : yymsp[-2].minor.yy148;
+    sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy190.pExpr);
   }else{
-    sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy322);
+    sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy148);
+    sqlite3ExprDelete(pParse->db, yymsp[-1].minor.yy72);
   }
-  yygotominor.yy118.zStart = yymsp[-4].minor.yy0.z;
-  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
 }
         break;
-      case 233: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */
+      case 193: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy322, yymsp[-2].minor.yy118.pExpr);
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yygotominor.yy322, yymsp[0].minor.yy118.pExpr);
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy148, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-4].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy148, yymsp[0].minor.yy190.pExpr);
 }
         break;
-      case 234: /* case_exprlist ::= WHEN expr THEN expr */
+      case 194: /* case_exprlist ::= WHEN expr THEN expr */
 {
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yygotominor.yy322, yymsp[0].minor.yy118.pExpr);
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy190.pExpr);
+  yymsp[-3].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy148, yymsp[0].minor.yy190.pExpr);
 }
         break;
-      case 243: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP idxlist RP */
+      case 197: /* case_operand ::= expr */
+{yymsp[0].minor.yy72 = yymsp[0].minor.yy190.pExpr; /*A-overwrites-X*/}
+        break;
+      case 200: /* nexprlist ::= nexprlist COMMA expr */
+{yymsp[-2].minor.yy148 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy148,yymsp[0].minor.yy190.pExpr);}
+        break;
+      case 201: /* nexprlist ::= expr */
+{yymsp[0].minor.yy148 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy190.pExpr); /*A-overwrites-Y*/}
+        break;
+      case 203: /* paren_exprlist ::= LP exprlist RP */
+      case 208: /* eidlist_opt ::= LP eidlist RP */ yytestcase(yyruleno==208);
+{yymsp[-2].minor.yy148 = yymsp[-1].minor.yy148;}
+        break;
+      case 204: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */
 {
-  sqlite3CreateIndex(pParse, &yymsp[-6].minor.yy0, &yymsp[-5].minor.yy0, 
-                     sqlite3SrcListAppend(pParse->db,0,&yymsp[-3].minor.yy0,0), yymsp[-1].minor.yy322, yymsp[-9].minor.yy4,
-                      &yymsp[-10].minor.yy0, &yymsp[0].minor.yy0, SQLITE_SO_ASC, yymsp[-7].minor.yy4);
+  sqlite3CreateIndex(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, 
+                     sqlite3SrcListAppend(pParse->db,0,&yymsp[-4].minor.yy0,0), yymsp[-2].minor.yy148, yymsp[-10].minor.yy194,
+                      &yymsp[-11].minor.yy0, yymsp[0].minor.yy72, SQLITE_SO_ASC, yymsp[-8].minor.yy194, SQLITE_IDXTYPE_APPDEF);
 }
         break;
-      case 244: /* uniqueflag ::= UNIQUE */
-      case 298: /* raisetype ::= ABORT */ yytestcase(yyruleno==298);
-{yygotominor.yy4 = OE_Abort;}
+      case 205: /* uniqueflag ::= UNIQUE */
+      case 246: /* raisetype ::= ABORT */ yytestcase(yyruleno==246);
+{yymsp[0].minor.yy194 = OE_Abort;}
         break;
-      case 245: /* uniqueflag ::= */
-{yygotominor.yy4 = OE_None;}
+      case 206: /* uniqueflag ::= */
+{yymsp[1].minor.yy194 = OE_None;}
         break;
-      case 248: /* idxlist ::= idxlist COMMA nm collate sortorder */
+      case 209: /* eidlist ::= eidlist COMMA nm collate sortorder */
 {
-  Expr *p = 0;
-  if( yymsp[-1].minor.yy0.n>0 ){
-    p = sqlite3Expr(pParse->db, TK_COLUMN, 0);
-    sqlite3ExprSetCollByToken(pParse, p, &yymsp[-1].minor.yy0);
-  }
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy322, p);
-  sqlite3ExprListSetName(pParse,yygotominor.yy322,&yymsp[-2].minor.yy0,1);
-  sqlite3ExprListCheckLength(pParse, yygotominor.yy322, "index");
-  if( yygotominor.yy322 ) yygotominor.yy322->a[yygotominor.yy322->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy4;
+  yymsp[-4].minor.yy148 = parserAddExprIdListTerm(pParse, yymsp[-4].minor.yy148, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy194, yymsp[0].minor.yy194);
 }
         break;
-      case 249: /* idxlist ::= nm collate sortorder */
+      case 210: /* eidlist ::= nm collate sortorder */
 {
-  Expr *p = 0;
-  if( yymsp[-1].minor.yy0.n>0 ){
-    p = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
-    sqlite3ExprSetCollByToken(pParse, p, &yymsp[-1].minor.yy0);
-  }
-  yygotominor.yy322 = sqlite3ExprListAppend(pParse,0, p);
-  sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[-2].minor.yy0, 1);
-  sqlite3ExprListCheckLength(pParse, yygotominor.yy322, "index");
-  if( yygotominor.yy322 ) yygotominor.yy322->a[yygotominor.yy322->nExpr-1].sortOrder = (u8)yymsp[0].minor.yy4;
+  yymsp[-2].minor.yy148 = parserAddExprIdListTerm(pParse, 0, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy194, yymsp[0].minor.yy194); /*A-overwrites-Y*/
 }
         break;
-      case 250: /* collate ::= */
-{yygotominor.yy0.z = 0; yygotominor.yy0.n = 0;}
-        break;
-      case 252: /* cmd ::= DROP INDEX ifexists fullname */
-{sqlite3DropIndex(pParse, yymsp[0].minor.yy259, yymsp[-1].minor.yy4);}
+      case 213: /* cmd ::= DROP INDEX ifexists fullname */
+{sqlite3DropIndex(pParse, yymsp[0].minor.yy185, yymsp[-1].minor.yy194);}
         break;
-      case 253: /* cmd ::= VACUUM */
-      case 254: /* cmd ::= VACUUM nm */ yytestcase(yyruleno==254);
+      case 214: /* cmd ::= VACUUM */
+      case 215: /* cmd ::= VACUUM nm */ yytestcase(yyruleno==215);
 {sqlite3Vacuum(pParse);}
         break;
-      case 255: /* cmd ::= PRAGMA nm dbnm */
+      case 216: /* cmd ::= PRAGMA nm dbnm */
 {sqlite3Pragma(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0,0);}
         break;
-      case 256: /* cmd ::= PRAGMA nm dbnm EQ nmnum */
+      case 217: /* cmd ::= PRAGMA nm dbnm EQ nmnum */
 {sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,0);}
         break;
-      case 257: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */
+      case 218: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */
 {sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,0);}
         break;
-      case 258: /* cmd ::= PRAGMA nm dbnm EQ minus_num */
+      case 219: /* cmd ::= PRAGMA nm dbnm EQ minus_num */
 {sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,1);}
         break;
-      case 259: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */
+      case 220: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */
 {sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,1);}
         break;
-      case 270: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */
+      case 223: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */
 {
   Token all;
   all.z = yymsp[-3].minor.yy0.z;
   all.n = (int)(yymsp[0].minor.yy0.z - yymsp[-3].minor.yy0.z) + yymsp[0].minor.yy0.n;
-  sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy203, &all);
+  sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy145, &all);
 }
         break;
-      case 271: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */
+      case 224: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */
 {
-  sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy4, yymsp[-4].minor.yy90.a, yymsp[-4].minor.yy90.b, yymsp[-2].minor.yy259, yymsp[0].minor.yy314, yymsp[-10].minor.yy4, yymsp[-8].minor.yy4);
-  yygotominor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0);
+  sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy194, yymsp[-4].minor.yy332.a, yymsp[-4].minor.yy332.b, yymsp[-2].minor.yy185, yymsp[0].minor.yy72, yymsp[-10].minor.yy194, yymsp[-8].minor.yy194);
+  yymsp[-10].minor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0); /*A-overwrites-T*/
 }
         break;
-      case 272: /* trigger_time ::= BEFORE */
-      case 275: /* trigger_time ::= */ yytestcase(yyruleno==275);
-{ yygotominor.yy4 = TK_BEFORE; }
+      case 225: /* trigger_time ::= BEFORE */
+{ yymsp[0].minor.yy194 = TK_BEFORE; }
+        break;
+      case 226: /* trigger_time ::= AFTER */
+{ yymsp[0].minor.yy194 = TK_AFTER;  }
         break;
-      case 273: /* trigger_time ::= AFTER */
-{ yygotominor.yy4 = TK_AFTER;  }
+      case 227: /* trigger_time ::= INSTEAD OF */
+{ yymsp[-1].minor.yy194 = TK_INSTEAD;}
         break;
-      case 274: /* trigger_time ::= INSTEAD OF */
-{ yygotominor.yy4 = TK_INSTEAD;}
+      case 228: /* trigger_time ::= */
+{ yymsp[1].minor.yy194 = TK_BEFORE; }
         break;
-      case 276: /* trigger_event ::= DELETE|INSERT */
-      case 277: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==277);
-{yygotominor.yy90.a = yymsp[0].major; yygotominor.yy90.b = 0;}
+      case 229: /* trigger_event ::= DELETE|INSERT */
+      case 230: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==230);
+{yymsp[0].minor.yy332.a = yymsp[0].major; /*A-overwrites-X*/ yymsp[0].minor.yy332.b = 0;}
         break;
-      case 278: /* trigger_event ::= UPDATE OF inscollist */
-{yygotominor.yy90.a = TK_UPDATE; yygotominor.yy90.b = yymsp[0].minor.yy384;}
+      case 231: /* trigger_event ::= UPDATE OF idlist */
+{yymsp[-2].minor.yy332.a = TK_UPDATE; yymsp[-2].minor.yy332.b = yymsp[0].minor.yy254;}
         break;
-      case 281: /* when_clause ::= */
-      case 303: /* key_opt ::= */ yytestcase(yyruleno==303);
-{ yygotominor.yy314 = 0; }
+      case 232: /* when_clause ::= */
+      case 251: /* key_opt ::= */ yytestcase(yyruleno==251);
+{ yymsp[1].minor.yy72 = 0; }
         break;
-      case 282: /* when_clause ::= WHEN expr */
-      case 304: /* key_opt ::= KEY expr */ yytestcase(yyruleno==304);
-{ yygotominor.yy314 = yymsp[0].minor.yy118.pExpr; }
+      case 233: /* when_clause ::= WHEN expr */
+      case 252: /* key_opt ::= KEY expr */ yytestcase(yyruleno==252);
+{ yymsp[-1].minor.yy72 = yymsp[0].minor.yy190.pExpr; }
         break;
-      case 283: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */
+      case 234: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */
 {
-  assert( yymsp[-2].minor.yy203!=0 );
-  yymsp[-2].minor.yy203->pLast->pNext = yymsp[-1].minor.yy203;
-  yymsp[-2].minor.yy203->pLast = yymsp[-1].minor.yy203;
-  yygotominor.yy203 = yymsp[-2].minor.yy203;
+  assert( yymsp[-2].minor.yy145!=0 );
+  yymsp[-2].minor.yy145->pLast->pNext = yymsp[-1].minor.yy145;
+  yymsp[-2].minor.yy145->pLast = yymsp[-1].minor.yy145;
 }
         break;
-      case 284: /* trigger_cmd_list ::= trigger_cmd SEMI */
+      case 235: /* trigger_cmd_list ::= trigger_cmd SEMI */
 { 
-  assert( yymsp[-1].minor.yy203!=0 );
-  yymsp[-1].minor.yy203->pLast = yymsp[-1].minor.yy203;
-  yygotominor.yy203 = yymsp[-1].minor.yy203;
+  assert( yymsp[-1].minor.yy145!=0 );
+  yymsp[-1].minor.yy145->pLast = yymsp[-1].minor.yy145;
 }
         break;
-      case 286: /* trnm ::= nm DOT nm */
+      case 236: /* trnm ::= nm DOT nm */
 {
-  yygotominor.yy0 = yymsp[0].minor.yy0;
+  yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;
   sqlite3ErrorMsg(pParse, 
         "qualified table names are not allowed on INSERT, UPDATE, and DELETE "
         "statements within triggers");
 }
         break;
-      case 288: /* tridxby ::= INDEXED BY nm */
+      case 237: /* tridxby ::= INDEXED BY nm */
 {
   sqlite3ErrorMsg(pParse,
         "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "
         "within triggers");
 }
         break;
-      case 289: /* tridxby ::= NOT INDEXED */
+      case 238: /* tridxby ::= NOT INDEXED */
 {
   sqlite3ErrorMsg(pParse,
         "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "
         "within triggers");
 }
         break;
-      case 290: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt */
-{ yygotominor.yy203 = sqlite3TriggerUpdateStep(pParse->db, &yymsp[-4].minor.yy0, yymsp[-1].minor.yy322, yymsp[0].minor.yy314, yymsp[-5].minor.yy210); }
+      case 239: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt */
+{yymsp[-6].minor.yy145 = sqlite3TriggerUpdateStep(pParse->db, &yymsp[-4].minor.yy0, yymsp[-1].minor.yy148, yymsp[0].minor.yy72, yymsp[-5].minor.yy194);}
         break;
-      case 291: /* trigger_cmd ::= insert_cmd INTO trnm inscollist_opt VALUES LP itemlist RP */
-{yygotominor.yy203 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy384, yymsp[-1].minor.yy322, 0, yymsp[-7].minor.yy210);}
+      case 240: /* trigger_cmd ::= insert_cmd INTO trnm idlist_opt select */
+{yymsp[-4].minor.yy145 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy254, yymsp[0].minor.yy243, yymsp[-4].minor.yy194);/*A-overwrites-R*/}
         break;
-      case 292: /* trigger_cmd ::= insert_cmd INTO trnm inscollist_opt select */
-{yygotominor.yy203 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy384, 0, yymsp[0].minor.yy387, yymsp[-4].minor.yy210);}
+      case 241: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt */
+{yymsp[-4].minor.yy145 = sqlite3TriggerDeleteStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[0].minor.yy72);}
         break;
-      case 293: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt */
-{yygotominor.yy203 = sqlite3TriggerDeleteStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[0].minor.yy314);}
+      case 242: /* trigger_cmd ::= select */
+{yymsp[0].minor.yy145 = sqlite3TriggerSelectStep(pParse->db, yymsp[0].minor.yy243); /*A-overwrites-X*/}
         break;
-      case 294: /* trigger_cmd ::= select */
-{yygotominor.yy203 = sqlite3TriggerSelectStep(pParse->db, yymsp[0].minor.yy387); }
-        break;
-      case 295: /* expr ::= RAISE LP IGNORE RP */
+      case 243: /* expr ::= RAISE LP IGNORE RP */
 {
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, 0); 
-  if( yygotominor.yy118.pExpr ){
-    yygotominor.yy118.pExpr->affinity = OE_Ignore;
+  spanSet(&yymsp[-3].minor.yy190,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-X*/
+  yymsp[-3].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, 0); 
+  if( yymsp[-3].minor.yy190.pExpr ){
+    yymsp[-3].minor.yy190.pExpr->affinity = OE_Ignore;
   }
-  yygotominor.yy118.zStart = yymsp[-3].minor.yy0.z;
-  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
 }
         break;
-      case 296: /* expr ::= RAISE LP raisetype COMMA nm RP */
+      case 244: /* expr ::= RAISE LP raisetype COMMA nm RP */
 {
-  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, &yymsp[-1].minor.yy0); 
-  if( yygotominor.yy118.pExpr ) {
-    yygotominor.yy118.pExpr->affinity = (char)yymsp[-3].minor.yy4;
+  spanSet(&yymsp[-5].minor.yy190,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0);  /*A-overwrites-X*/
+  yymsp[-5].minor.yy190.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, &yymsp[-1].minor.yy0); 
+  if( yymsp[-5].minor.yy190.pExpr ) {
+    yymsp[-5].minor.yy190.pExpr->affinity = (char)yymsp[-3].minor.yy194;
   }
-  yygotominor.yy118.zStart = yymsp[-5].minor.yy0.z;
-  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
 }
         break;
-      case 297: /* raisetype ::= ROLLBACK */
-{yygotominor.yy4 = OE_Rollback;}
+      case 245: /* raisetype ::= ROLLBACK */
+{yymsp[0].minor.yy194 = OE_Rollback;}
         break;
-      case 299: /* raisetype ::= FAIL */
-{yygotominor.yy4 = OE_Fail;}
+      case 247: /* raisetype ::= FAIL */
+{yymsp[0].minor.yy194 = OE_Fail;}
         break;
-      case 300: /* cmd ::= DROP TRIGGER ifexists fullname */
+      case 248: /* cmd ::= DROP TRIGGER ifexists fullname */
 {
-  sqlite3DropTrigger(pParse,yymsp[0].minor.yy259,yymsp[-1].minor.yy4);
+  sqlite3DropTrigger(pParse,yymsp[0].minor.yy185,yymsp[-1].minor.yy194);
 }
         break;
-      case 301: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */
+      case 249: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */
 {
-  sqlite3Attach(pParse, yymsp[-3].minor.yy118.pExpr, yymsp[-1].minor.yy118.pExpr, yymsp[0].minor.yy314);
+  sqlite3Attach(pParse, yymsp[-3].minor.yy190.pExpr, yymsp[-1].minor.yy190.pExpr, yymsp[0].minor.yy72);
 }
         break;
-      case 302: /* cmd ::= DETACH database_kw_opt expr */
+      case 250: /* cmd ::= DETACH database_kw_opt expr */
 {
-  sqlite3Detach(pParse, yymsp[0].minor.yy118.pExpr);
+  sqlite3Detach(pParse, yymsp[0].minor.yy190.pExpr);
 }
         break;
-      case 307: /* cmd ::= REINDEX */
+      case 253: /* cmd ::= REINDEX */
 {sqlite3Reindex(pParse, 0, 0);}
         break;
-      case 308: /* cmd ::= REINDEX nm dbnm */
+      case 254: /* cmd ::= REINDEX nm dbnm */
 {sqlite3Reindex(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
         break;
-      case 309: /* cmd ::= ANALYZE */
+      case 255: /* cmd ::= ANALYZE */
 {sqlite3Analyze(pParse, 0, 0);}
         break;
-      case 310: /* cmd ::= ANALYZE nm dbnm */
+      case 256: /* cmd ::= ANALYZE nm dbnm */
 {sqlite3Analyze(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
         break;
-      case 311: /* cmd ::= ALTER TABLE fullname RENAME TO nm */
+      case 257: /* cmd ::= ALTER TABLE fullname RENAME TO nm */
 {
-  sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy259,&yymsp[0].minor.yy0);
+  sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy185,&yymsp[0].minor.yy0);
 }
         break;
-      case 312: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column */
+      case 258: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist */
 {
-  sqlite3AlterFinishAddColumn(pParse, &yymsp[0].minor.yy0);
+  yymsp[-1].minor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-1].minor.yy0.z) + pParse->sLastToken.n;
+  sqlite3AlterFinishAddColumn(pParse, &yymsp[-1].minor.yy0);
 }
         break;
-      case 313: /* add_column_fullname ::= fullname */
+      case 259: /* add_column_fullname ::= fullname */
 {
-  pParse->db->lookaside.bEnabled = 0;
-  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy259);
+  disableLookaside(pParse);
+  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy185);
 }
         break;
-      case 316: /* cmd ::= create_vtab */
+      case 260: /* cmd ::= create_vtab */
 {sqlite3VtabFinishParse(pParse,0);}
         break;
-      case 317: /* cmd ::= create_vtab LP vtabarglist RP */
+      case 261: /* cmd ::= create_vtab LP vtabarglist RP */
 {sqlite3VtabFinishParse(pParse,&yymsp[0].minor.yy0);}
         break;
-      case 318: /* create_vtab ::= createkw VIRTUAL TABLE nm dbnm USING nm */
+      case 262: /* create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */
 {
-    sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0);
+    sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0, yymsp[-4].minor.yy194);
 }
         break;
-      case 321: /* vtabarg ::= */
+      case 263: /* vtabarg ::= */
 {sqlite3VtabArgInit(pParse);}
         break;
-      case 323: /* vtabargtoken ::= ANY */
-      case 324: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==324);
-      case 325: /* lp ::= LP */ yytestcase(yyruleno==325);
+      case 264: /* vtabargtoken ::= ANY */
+      case 265: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==265);
+      case 266: /* lp ::= LP */ yytestcase(yyruleno==266);
 {sqlite3VtabArgExtend(pParse,&yymsp[0].minor.yy0);}
         break;
+      case 267: /* with ::= */
+{yymsp[1].minor.yy285 = 0;}
+        break;
+      case 268: /* with ::= WITH wqlist */
+{ yymsp[-1].minor.yy285 = yymsp[0].minor.yy285; }
+        break;
+      case 269: /* with ::= WITH RECURSIVE wqlist */
+{ yymsp[-2].minor.yy285 = yymsp[0].minor.yy285; }
+        break;
+      case 270: /* wqlist ::= nm eidlist_opt AS LP select RP */
+{
+  yymsp[-5].minor.yy285 = sqlite3WithAdd(pParse, 0, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy148, yymsp[-1].minor.yy243); /*A-overwrites-X*/
+}
+        break;
+      case 271: /* wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */
+{
+  yymsp[-7].minor.yy285 = sqlite3WithAdd(pParse, yymsp[-7].minor.yy285, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy148, yymsp[-1].minor.yy243);
+}
+        break;
       default:
-      /* (0) input ::= cmdlist */ yytestcase(yyruleno==0);
-      /* (1) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==1);
-      /* (2) cmdlist ::= ecmd */ yytestcase(yyruleno==2);
-      /* (3) ecmd ::= SEMI */ yytestcase(yyruleno==3);
-      /* (4) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==4);
-      /* (10) trans_opt ::= */ yytestcase(yyruleno==10);
-      /* (11) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==11);
-      /* (12) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==12);
-      /* (20) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==20);
-      /* (21) savepoint_opt ::= */ yytestcase(yyruleno==21);
-      /* (25) cmd ::= create_table create_table_args */ yytestcase(yyruleno==25);
-      /* (34) columnlist ::= columnlist COMMA column */ yytestcase(yyruleno==34);
-      /* (35) columnlist ::= column */ yytestcase(yyruleno==35);
-      /* (44) type ::= */ yytestcase(yyruleno==44);
-      /* (51) signed ::= plus_num */ yytestcase(yyruleno==51);
-      /* (52) signed ::= minus_num */ yytestcase(yyruleno==52);
-      /* (53) carglist ::= carglist carg */ yytestcase(yyruleno==53);
-      /* (54) carglist ::= */ yytestcase(yyruleno==54);
-      /* (55) carg ::= CONSTRAINT nm ccons */ yytestcase(yyruleno==55);
-      /* (56) carg ::= ccons */ yytestcase(yyruleno==56);
-      /* (62) ccons ::= NULL onconf */ yytestcase(yyruleno==62);
-      /* (90) conslist ::= conslist COMMA tcons */ yytestcase(yyruleno==90);
-      /* (91) conslist ::= conslist tcons */ yytestcase(yyruleno==91);
-      /* (92) conslist ::= tcons */ yytestcase(yyruleno==92);
-      /* (93) tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==93);
-      /* (268) plus_opt ::= PLUS */ yytestcase(yyruleno==268);
-      /* (269) plus_opt ::= */ yytestcase(yyruleno==269);
-      /* (279) foreach_clause ::= */ yytestcase(yyruleno==279);
-      /* (280) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==280);
-      /* (287) tridxby ::= */ yytestcase(yyruleno==287);
-      /* (305) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==305);
-      /* (306) database_kw_opt ::= */ yytestcase(yyruleno==306);
-      /* (314) kwcolumn_opt ::= */ yytestcase(yyruleno==314);
-      /* (315) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==315);
-      /* (319) vtabarglist ::= vtabarg */ yytestcase(yyruleno==319);
-      /* (320) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==320);
-      /* (322) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==322);
-      /* (326) anylist ::= */ yytestcase(yyruleno==326);
-      /* (327) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==327);
-      /* (328) anylist ::= anylist ANY */ yytestcase(yyruleno==328);
+      /* (272) input ::= cmdlist */ yytestcase(yyruleno==272);
+      /* (273) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==273);
+      /* (274) cmdlist ::= ecmd (OPTIMIZED OUT) */ assert(yyruleno!=274);
+      /* (275) ecmd ::= SEMI */ yytestcase(yyruleno==275);
+      /* (276) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==276);
+      /* (277) explain ::= */ yytestcase(yyruleno==277);
+      /* (278) trans_opt ::= */ yytestcase(yyruleno==278);
+      /* (279) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==279);
+      /* (280) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==280);
+      /* (281) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==281);
+      /* (282) savepoint_opt ::= */ yytestcase(yyruleno==282);
+      /* (283) cmd ::= create_table create_table_args */ yytestcase(yyruleno==283);
+      /* (284) columnlist ::= columnlist COMMA columnname carglist */ yytestcase(yyruleno==284);
+      /* (285) columnlist ::= columnname carglist */ yytestcase(yyruleno==285);
+      /* (286) nm ::= ID|INDEXED */ yytestcase(yyruleno==286);
+      /* (287) nm ::= STRING */ yytestcase(yyruleno==287);
+      /* (288) nm ::= JOIN_KW */ yytestcase(yyruleno==288);
+      /* (289) typetoken ::= typename */ yytestcase(yyruleno==289);
+      /* (290) typename ::= ID|STRING */ yytestcase(yyruleno==290);
+      /* (291) signed ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=291);
+      /* (292) signed ::= minus_num (OPTIMIZED OUT) */ assert(yyruleno!=292);
+      /* (293) carglist ::= carglist ccons */ yytestcase(yyruleno==293);
+      /* (294) carglist ::= */ yytestcase(yyruleno==294);
+      /* (295) ccons ::= NULL onconf */ yytestcase(yyruleno==295);
+      /* (296) conslist_opt ::= COMMA conslist */ yytestcase(yyruleno==296);
+      /* (297) conslist ::= conslist tconscomma tcons */ yytestcase(yyruleno==297);
+      /* (298) conslist ::= tcons (OPTIMIZED OUT) */ assert(yyruleno!=298);
+      /* (299) tconscomma ::= */ yytestcase(yyruleno==299);
+      /* (300) defer_subclause_opt ::= defer_subclause (OPTIMIZED OUT) */ assert(yyruleno!=300);
+      /* (301) resolvetype ::= raisetype (OPTIMIZED OUT) */ assert(yyruleno!=301);
+      /* (302) selectnowith ::= oneselect (OPTIMIZED OUT) */ assert(yyruleno!=302);
+      /* (303) oneselect ::= values */ yytestcase(yyruleno==303);
+      /* (304) sclp ::= selcollist COMMA */ yytestcase(yyruleno==304);
+      /* (305) as ::= ID|STRING */ yytestcase(yyruleno==305);
+      /* (306) expr ::= term (OPTIMIZED OUT) */ assert(yyruleno!=306);
+      /* (307) exprlist ::= nexprlist */ yytestcase(yyruleno==307);
+      /* (308) nmnum ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=308);
+      /* (309) nmnum ::= nm (OPTIMIZED OUT) */ assert(yyruleno!=309);
+      /* (310) nmnum ::= ON */ yytestcase(yyruleno==310);
+      /* (311) nmnum ::= DELETE */ yytestcase(yyruleno==311);
+      /* (312) nmnum ::= DEFAULT */ yytestcase(yyruleno==312);
+      /* (313) plus_num ::= INTEGER|FLOAT */ yytestcase(yyruleno==313);
+      /* (314) foreach_clause ::= */ yytestcase(yyruleno==314);
+      /* (315) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==315);
+      /* (316) trnm ::= nm */ yytestcase(yyruleno==316);
+      /* (317) tridxby ::= */ yytestcase(yyruleno==317);
+      /* (318) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==318);
+      /* (319) database_kw_opt ::= */ yytestcase(yyruleno==319);
+      /* (320) kwcolumn_opt ::= */ yytestcase(yyruleno==320);
+      /* (321) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==321);
+      /* (322) vtabarglist ::= vtabarg */ yytestcase(yyruleno==322);
+      /* (323) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==323);
+      /* (324) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==324);
+      /* (325) anylist ::= */ yytestcase(yyruleno==325);
+      /* (326) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==326);
+      /* (327) anylist ::= anylist ANY */ yytestcase(yyruleno==327);
         break;
+/********** End reduce actions ************************************************/
   };
+  assert( yyruleno<sizeof(yyRuleInfo)/sizeof(yyRuleInfo[0]) );
   yygoto = yyRuleInfo[yyruleno].lhs;
   yysize = yyRuleInfo[yyruleno].nrhs;
-  yypParser->yyidx -= yysize;
   yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto);
-  if( yyact < YYNSTATE ){
-#ifdef NDEBUG
-    /* If we are not debugging and the reduce action popped at least
-    ** one element off the stack, then we can push the new element back
-    ** onto the stack here, and skip the stack overflow test in yy_shift().
-    ** That gives a significant speed improvement. */
-    if( yysize ){
-      yypParser->yyidx++;
-      yymsp -= yysize-1;
-      yymsp->stateno = (YYACTIONTYPE)yyact;
-      yymsp->major = (YYCODETYPE)yygoto;
-      yymsp->minor = yygotominor;
-    }else
-#endif
-    {
-      yy_shift(yypParser,yyact,yygoto,&yygotominor);
-    }
+  if( yyact <= YY_MAX_SHIFTREDUCE ){
+    if( yyact>YY_MAX_SHIFT ){
+      yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
+    }
+    yymsp -= yysize-1;
+    yypParser->yytos = yymsp;
+    yymsp->stateno = (YYACTIONTYPE)yyact;
+    yymsp->major = (YYCODETYPE)yygoto;
+    yyTraceShift(yypParser, yyact);
   }else{
-    assert( yyact == YYNSTATE + YYNRULE + 1 );
+    assert( yyact == YY_ACCEPT_ACTION );
+    yypParser->yytos -= yysize;
     yy_accept(yypParser);
   }
 }
@@ -109141,9 +134986,11 @@ static void yy_parse_failed(
     fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt);
   }
 #endif
-  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+  while( yypParser->yytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);
   /* Here code is inserted which will be executed whenever the
   ** parser fails */
+/************ Begin %parse_failure code ***************************************/
+/************ End %parse_failure code *****************************************/
   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
 }
 #endif /* YYNOERRORRECOVERY */
@@ -109154,15 +135001,16 @@ static void yy_parse_failed(
 static void yy_syntax_error(
   yyParser *yypParser,           /* The parser */
   int yymajor,                   /* The major type of the error token */
-  YYMINORTYPE yyminor            /* The minor type of the error token */
+  sqlite3ParserTOKENTYPE yyminor         /* The minor type of the error token */
 ){
   sqlite3ParserARG_FETCH;
-#define TOKEN (yyminor.yy0)
+#define TOKEN yyminor
+/************ Begin %syntax_error code ****************************************/
 
   UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */
   assert( TOKEN.z[0] );  /* The tokenizer always gives us a token */
   sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
-  pParse->parseError = 1;
+/************ End %syntax_error code ******************************************/
   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
 }
 
@@ -109178,9 +135026,14 @@ static void yy_accept(
     fprintf(yyTraceFILE,"%sAccept!\n",yyTracePrompt);
   }
 #endif
-  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+#ifndef YYNOERRORRECOVERY
+  yypParser->yyerrcnt = -1;
+#endif
+  assert( yypParser->yytos==yypParser->yystack );
   /* Here code is inserted which will be executed whenever the
   ** parser accepts */
+/*********** Begin %parse_accept code *****************************************/
+/*********** End %parse_accept code *******************************************/
   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
 }
 
@@ -109210,7 +135063,7 @@ SQLITE_PRIVATE void sqlite3Parser(
   sqlite3ParserARG_PDECL               /* Optional %extra_argument parameter */
 ){
   YYMINORTYPE yyminorunion;
-  int yyact;            /* The parser action. */
+  unsigned int yyact;   /* The parser action. */
 #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
   int yyendofinput;     /* True if we are at the end of input */
 #endif
@@ -109219,23 +135072,8 @@ SQLITE_PRIVATE void sqlite3Parser(
 #endif
   yyParser *yypParser;  /* The parser */
 
-  /* (re)initialize the parser, if necessary */
   yypParser = (yyParser*)yyp;
-  if( yypParser->yyidx<0 ){
-#if YYSTACKDEPTH<=0
-    if( yypParser->yystksz <=0 ){
-      /*memset(&yyminorunion, 0, sizeof(yyminorunion));*/
-      yyminorunion = yyzerominor;
-      yyStackOverflow(yypParser, &yyminorunion);
-      return;
-    }
-#endif
-    yypParser->yyidx = 0;
-    yypParser->yyerrcnt = -1;
-    yypParser->yystack[0].stateno = 0;
-    yypParser->yystack[0].major = 0;
-  }
-  yyminorunion.yy0 = yyminor;
+  assert( yypParser->yytos!=0 );
 #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
   yyendofinput = (yymajor==0);
 #endif
@@ -109243,20 +135081,23 @@ SQLITE_PRIVATE void sqlite3Parser(
 
 #ifndef NDEBUG
   if( yyTraceFILE ){
-    fprintf(yyTraceFILE,"%sInput %s\n",yyTracePrompt,yyTokenName[yymajor]);
+    fprintf(yyTraceFILE,"%sInput '%s'\n",yyTracePrompt,yyTokenName[yymajor]);
   }
 #endif
 
   do{
     yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
-    if( yyact<YYNSTATE ){
-      yy_shift(yypParser,yyact,yymajor,&yyminorunion);
+    if( yyact <= YY_MAX_SHIFTREDUCE ){
+      yy_shift(yypParser,yyact,yymajor,yyminor);
+#ifndef YYNOERRORRECOVERY
       yypParser->yyerrcnt--;
+#endif
       yymajor = YYNOCODE;
-    }else if( yyact < YYNSTATE + YYNRULE ){
-      yy_reduce(yypParser,yyact-YYNSTATE);
+    }else if( yyact <= YY_MAX_REDUCE ){
+      yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
     }else{
       assert( yyact == YY_ERROR_ACTION );
+      yyminorunion.yy0 = yyminor;
 #ifdef YYERRORSYMBOL
       int yymx;
 #endif
@@ -109286,9 +135127,9 @@ SQLITE_PRIVATE void sqlite3Parser(
       **
       */
       if( yypParser->yyerrcnt<0 ){
-        yy_syntax_error(yypParser,yymajor,yyminorunion);
+        yy_syntax_error(yypParser,yymajor,yyminor);
       }
-      yymx = yypParser->yystack[yypParser->yyidx].major;
+      yymx = yypParser->yytos->major;
       if( yymx==YYERRORSYMBOL || yyerrorhit ){
 #ifndef NDEBUG
         if( yyTraceFILE ){
@@ -109296,26 +135137,26 @@ SQLITE_PRIVATE void sqlite3Parser(
              yyTracePrompt,yyTokenName[yymajor]);
         }
 #endif
-        yy_destructor(yypParser, (YYCODETYPE)yymajor,&yyminorunion);
+        yy_destructor(yypParser, (YYCODETYPE)yymajor, &yyminorunion);
         yymajor = YYNOCODE;
       }else{
-         while(
-          yypParser->yyidx >= 0 &&
-          yymx != YYERRORSYMBOL &&
-          (yyact = yy_find_reduce_action(
-                        yypParser->yystack[yypParser->yyidx].stateno,
-                        YYERRORSYMBOL)) >= YYNSTATE
+        while( yypParser->yytos >= &yypParser->yystack
+            && yymx != YYERRORSYMBOL
+            && (yyact = yy_find_reduce_action(
+                        yypParser->yytos->stateno,
+                        YYERRORSYMBOL)) >= YY_MIN_REDUCE
         ){
           yy_pop_parser_stack(yypParser);
         }
-        if( yypParser->yyidx < 0 || yymajor==0 ){
+        if( yypParser->yytos < yypParser->yystack || yymajor==0 ){
           yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
           yy_parse_failed(yypParser);
+#ifndef YYNOERRORRECOVERY
+          yypParser->yyerrcnt = -1;
+#endif
           yymajor = YYNOCODE;
         }else if( yymx!=YYERRORSYMBOL ){
-          YYMINORTYPE u2;
-          u2.YYERRSYMDT = 0;
-          yy_shift(yypParser,yyact,YYERRORSYMBOL,&u2);
+          yy_shift(yypParser,yyact,YYERRORSYMBOL,yyminor);
         }
       }
       yypParser->yyerrcnt = 3;
@@ -109328,7 +135169,7 @@ SQLITE_PRIVATE void sqlite3Parser(
       ** Applications can set this macro (for example inside %include) if
       ** they intend to abandon the parse upon the first syntax error seen.
       */
-      yy_syntax_error(yypParser,yymajor,yyminorunion);
+      yy_syntax_error(yypParser,yymajor, yyminor);
       yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
       yymajor = YYNOCODE;
       
@@ -109343,17 +135184,32 @@ SQLITE_PRIVATE void sqlite3Parser(
       ** three input tokens have been successfully shifted.
       */
       if( yypParser->yyerrcnt<=0 ){
-        yy_syntax_error(yypParser,yymajor,yyminorunion);
+        yy_syntax_error(yypParser,yymajor, yyminor);
       }
       yypParser->yyerrcnt = 3;
       yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
       if( yyendofinput ){
         yy_parse_failed(yypParser);
+#ifndef YYNOERRORRECOVERY
+        yypParser->yyerrcnt = -1;
+#endif
       }
       yymajor = YYNOCODE;
 #endif
     }
-  }while( yymajor!=YYNOCODE && yypParser->yyidx>=0 );
+  }while( yymajor!=YYNOCODE && yypParser->yytos>yypParser->yystack );
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    yyStackEntry *i;
+    char cDiv = '[';
+    fprintf(yyTraceFILE,"%sReturn. Stack=",yyTracePrompt);
+    for(i=&yypParser->yystack[1]; i<=yypParser->yytos; i++){
+      fprintf(yyTraceFILE,"%c%s", cDiv, yyTokenName[i->major]);
+      cDiv = ' ';
+    }
+    fprintf(yyTraceFILE,"]\n");
+  }
+#endif
   return;
 }
 
@@ -109376,14 +135232,95 @@ SQLITE_PRIVATE void sqlite3Parser(
 ** individual tokens and sends those tokens one-by-one over to the
 ** parser for analysis.
 */
+/* #include "sqliteInt.h" */
 /* #include <stdlib.h> */
 
+/* Character classes for tokenizing
+**
+** In the sqlite3GetToken() function, a switch() on aiClass[c] is implemented
+** using a lookup table, whereas a switch() directly on c uses a binary search.
+** The lookup table is much faster.  To maximize speed, and to ensure that
+** a lookup table is used, all of the classes need to be small integers and
+** all of them need to be used within the switch.
+*/
+#define CC_X          0    /* The letter 'x', or start of BLOB literal */
+#define CC_KYWD       1    /* Alphabetics or '_'.  Usable in a keyword */
+#define CC_ID         2    /* unicode characters usable in IDs */
+#define CC_DIGIT      3    /* Digits */
+#define CC_DOLLAR     4    /* '$' */
+#define CC_VARALPHA   5    /* '@', '#', ':'.  Alphabetic SQL variables */
+#define CC_VARNUM     6    /* '?'.  Numeric SQL variables */
+#define CC_SPACE      7    /* Space characters */
+#define CC_QUOTE      8    /* '"', '\'', or '`'.  String literals, quoted ids */
+#define CC_QUOTE2     9    /* '['.   [...] style quoted ids */
+#define CC_PIPE      10    /* '|'.   Bitwise OR or concatenate */
+#define CC_MINUS     11    /* '-'.  Minus or SQL-style comment */
+#define CC_LT        12    /* '<'.  Part of < or <= or <> */
+#define CC_GT        13    /* '>'.  Part of > or >= */
+#define CC_EQ        14    /* '='.  Part of = or == */
+#define CC_BANG      15    /* '!'.  Part of != */
+#define CC_SLASH     16    /* '/'.  / or c-style comment */
+#define CC_LP        17    /* '(' */
+#define CC_RP        18    /* ')' */
+#define CC_SEMI      19    /* ';' */
+#define CC_PLUS      20    /* '+' */
+#define CC_STAR      21    /* '*' */
+#define CC_PERCENT   22    /* '%' */
+#define CC_COMMA     23    /* ',' */
+#define CC_AND       24    /* '&' */
+#define CC_TILDA     25    /* '~' */
+#define CC_DOT       26    /* '.' */
+#define CC_ILLEGAL   27    /* Illegal character */
+
+static const unsigned char aiClass[] = {
+#ifdef SQLITE_ASCII
+/*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
+/* 0x */   27, 27, 27, 27, 27, 27, 27, 27, 27,  7,  7, 27,  7,  7, 27, 27,
+/* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 2x */    7, 15,  8,  5,  4, 22, 24,  8, 17, 18, 21, 20, 23, 11, 26, 16,
+/* 3x */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  5, 19, 12, 14, 13,  6,
+/* 4x */    5,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+/* 5x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1,  9, 27, 27, 27,  1,
+/* 6x */    8,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+/* 7x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1, 27, 10, 27, 25, 27,
+/* 8x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* 9x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Ax */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Bx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Cx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Dx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Ex */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
+/* Fx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2
+#endif
+#ifdef SQLITE_EBCDIC
+/*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */
+/* 0x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27,  7,  7, 27, 27,
+/* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 2x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 3x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+/* 4x */    7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 12, 17, 20, 10,
+/* 5x */   24, 27, 27, 27, 27, 27, 27, 27, 27, 27, 15,  4, 21, 18, 19, 27,
+/* 6x */   11, 16, 27, 27, 27, 27, 27, 27, 27, 27, 27, 23, 22,  1, 13,  7,
+/* 7x */   27, 27, 27, 27, 27, 27, 27, 27, 27,  8,  5,  5,  5,  8, 14,  8,
+/* 8x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* 9x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* 9x */   25,  1,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Bx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27,  9, 27, 27, 27, 27, 27,
+/* Cx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Dx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Ex */   27, 27,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,
+/* Fx */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3, 27, 27, 27, 27, 27, 27,
+#endif
+};
+
 /*
-** The charMap() macro maps alphabetic characters into their
+** The charMap() macro maps alphabetic characters (only) into their
 ** lower-case ASCII equivalent.  On ASCII machines, this is just
 ** an upper-to-lower case map.  On EBCDIC machines we also need
-** to adjust the encoding.  Only alphabetic characters and underscores
-** need to be translated.
+** to adjust the encoding.  The mapping is only valid for alphabetics
+** which are the only characters for which this feature is used. 
+**
+** Used by keywordhash.h
 */
 #ifdef SQLITE_ASCII
 # define charMap(X) sqlite3UpperToLower[(unsigned char)X]
@@ -109417,7 +135354,7 @@ const unsigned char ebcdicToAscii[] = {
 ** returned.  If the input is not a keyword, TK_ID is returned.
 **
 ** The implementation of this routine was generated by a program,
-** mkkeywordhash.h, located in the tool subdirectory of the distribution.
+** mkkeywordhash.c, located in the tool subdirectory of the distribution.
 ** The output of the mkkeywordhash.c program is written into a file
 ** named keywordhash.h and then included into this source file by
 ** the #include below.
@@ -109437,20 +135374,20 @@ const unsigned char ebcdicToAscii[] = {
 ** is substantially reduced.  This is important for embedded applications
 ** on platforms with limited memory.
 */
-/* Hash score: 175 */
-static int keywordCode(const char *z, int n){
-  /* zText[] encodes 811 bytes of keywords in 541 bytes */
+/* Hash score: 182 */
+static int keywordCode(const char *z, int n, int *pType){
+  /* zText[] encodes 834 bytes of keywords in 554 bytes */
   /*   REINDEXEDESCAPEACHECKEYBEFOREIGNOREGEXPLAINSTEADDATABASELECT       */
   /*   ABLEFTHENDEFERRABLELSEXCEPTRANSACTIONATURALTERAISEXCLUSIVE         */
   /*   XISTSAVEPOINTERSECTRIGGEREFERENCESCONSTRAINTOFFSETEMPORARY         */
-  /*   UNIQUERYATTACHAVINGROUPDATEBEGINNERELEASEBETWEENOTNULLIKE          */
-  /*   CASCADELETECASECOLLATECREATECURRENT_DATEDETACHIMMEDIATEJOIN        */
-  /*   SERTMATCHPLANALYZEPRAGMABORTVALUESVIRTUALIMITWHENWHERENAME         */
-  /*   AFTEREPLACEANDEFAULTAUTOINCREMENTCASTCOLUMNCOMMITCONFLICTCROSS     */
-  /*   CURRENT_TIMESTAMPRIMARYDEFERREDISTINCTDROPFAILFROMFULLGLOBYIF      */
-  /*   ISNULLORDERESTRICTOUTERIGHTROLLBACKROWUNIONUSINGVACUUMVIEW         */
-  /*   INITIALLY                                                          */
-  static const char zText[540] = {
+  /*   UNIQUERYWITHOUTERELEASEATTACHAVINGROUPDATEBEGINNERECURSIVE         */
+  /*   BETWEENOTNULLIKECASCADELETECASECOLLATECREATECURRENT_DATEDETACH     */
+  /*   IMMEDIATEJOINSERTMATCHPLANALYZEPRAGMABORTVALUESVIRTUALIMITWHEN     */
+  /*   WHERENAMEAFTEREPLACEANDEFAULTAUTOINCREMENTCASTCOLUMNCOMMIT         */
+  /*   CONFLICTCROSSCURRENT_TIMESTAMPRIMARYDEFERREDISTINCTDROPFAIL        */
+  /*   FROMFULLGLOBYIFISNULLORDERESTRICTRIGHTROLLBACKROWUNIONUSING        */
+  /*   VACUUMVIEWINITIALLY                                                */
+  static const char zText[553] = {
     'R','E','I','N','D','E','X','E','D','E','S','C','A','P','E','A','C','H',
     'E','C','K','E','Y','B','E','F','O','R','E','I','G','N','O','R','E','G',
     'E','X','P','L','A','I','N','S','T','E','A','D','D','A','T','A','B','A',
@@ -109461,76 +135398,77 @@ static int keywordCode(const char *z, int n){
     'P','O','I','N','T','E','R','S','E','C','T','R','I','G','G','E','R','E',
     'F','E','R','E','N','C','E','S','C','O','N','S','T','R','A','I','N','T',
     'O','F','F','S','E','T','E','M','P','O','R','A','R','Y','U','N','I','Q',
-    'U','E','R','Y','A','T','T','A','C','H','A','V','I','N','G','R','O','U',
-    'P','D','A','T','E','B','E','G','I','N','N','E','R','E','L','E','A','S',
-    'E','B','E','T','W','E','E','N','O','T','N','U','L','L','I','K','E','C',
-    'A','S','C','A','D','E','L','E','T','E','C','A','S','E','C','O','L','L',
-    'A','T','E','C','R','E','A','T','E','C','U','R','R','E','N','T','_','D',
-    'A','T','E','D','E','T','A','C','H','I','M','M','E','D','I','A','T','E',
-    'J','O','I','N','S','E','R','T','M','A','T','C','H','P','L','A','N','A',
-    'L','Y','Z','E','P','R','A','G','M','A','B','O','R','T','V','A','L','U',
-    'E','S','V','I','R','T','U','A','L','I','M','I','T','W','H','E','N','W',
-    'H','E','R','E','N','A','M','E','A','F','T','E','R','E','P','L','A','C',
-    'E','A','N','D','E','F','A','U','L','T','A','U','T','O','I','N','C','R',
-    'E','M','E','N','T','C','A','S','T','C','O','L','U','M','N','C','O','M',
-    'M','I','T','C','O','N','F','L','I','C','T','C','R','O','S','S','C','U',
-    'R','R','E','N','T','_','T','I','M','E','S','T','A','M','P','R','I','M',
-    'A','R','Y','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T',
-    'D','R','O','P','F','A','I','L','F','R','O','M','F','U','L','L','G','L',
-    'O','B','Y','I','F','I','S','N','U','L','L','O','R','D','E','R','E','S',
-    'T','R','I','C','T','O','U','T','E','R','I','G','H','T','R','O','L','L',
-    'B','A','C','K','R','O','W','U','N','I','O','N','U','S','I','N','G','V',
-    'A','C','U','U','M','V','I','E','W','I','N','I','T','I','A','L','L','Y',
+    'U','E','R','Y','W','I','T','H','O','U','T','E','R','E','L','E','A','S',
+    'E','A','T','T','A','C','H','A','V','I','N','G','R','O','U','P','D','A',
+    'T','E','B','E','G','I','N','N','E','R','E','C','U','R','S','I','V','E',
+    'B','E','T','W','E','E','N','O','T','N','U','L','L','I','K','E','C','A',
+    'S','C','A','D','E','L','E','T','E','C','A','S','E','C','O','L','L','A',
+    'T','E','C','R','E','A','T','E','C','U','R','R','E','N','T','_','D','A',
+    'T','E','D','E','T','A','C','H','I','M','M','E','D','I','A','T','E','J',
+    'O','I','N','S','E','R','T','M','A','T','C','H','P','L','A','N','A','L',
+    'Y','Z','E','P','R','A','G','M','A','B','O','R','T','V','A','L','U','E',
+    'S','V','I','R','T','U','A','L','I','M','I','T','W','H','E','N','W','H',
+    'E','R','E','N','A','M','E','A','F','T','E','R','E','P','L','A','C','E',
+    'A','N','D','E','F','A','U','L','T','A','U','T','O','I','N','C','R','E',
+    'M','E','N','T','C','A','S','T','C','O','L','U','M','N','C','O','M','M',
+    'I','T','C','O','N','F','L','I','C','T','C','R','O','S','S','C','U','R',
+    'R','E','N','T','_','T','I','M','E','S','T','A','M','P','R','I','M','A',
+    'R','Y','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T','D',
+    'R','O','P','F','A','I','L','F','R','O','M','F','U','L','L','G','L','O',
+    'B','Y','I','F','I','S','N','U','L','L','O','R','D','E','R','E','S','T',
+    'R','I','C','T','R','I','G','H','T','R','O','L','L','B','A','C','K','R',
+    'O','W','U','N','I','O','N','U','S','I','N','G','V','A','C','U','U','M',
+    'V','I','E','W','I','N','I','T','I','A','L','L','Y',
   };
   static const unsigned char aHash[127] = {
-      72, 101, 114,  70,   0,  45,   0,   0,  78,   0,  73,   0,   0,
-      42,  12,  74,  15,   0, 113,  81,  50, 108,   0,  19,   0,   0,
-     118,   0, 116, 111,   0,  22,  89,   0,   9,   0,   0,  66,  67,
-       0,  65,   6,   0,  48,  86,  98,   0, 115,  97,   0,   0,  44,
-       0,  99,  24,   0,  17,   0, 119,  49,  23,   0,   5, 106,  25,
-      92,   0,   0, 121, 102,  56, 120,  53,  28,  51,   0,  87,   0,
-      96,  26,   0,  95,   0,   0,   0,  91,  88,  93,  84, 105,  14,
-      39, 104,   0,  77,   0,  18,  85, 107,  32,   0, 117,  76, 109,
-      58,  46,  80,   0,   0,  90,  40,   0, 112,   0,  36,   0,   0,
-      29,   0,  82,  59,  60,   0,  20,  57,   0,  52,
+      76, 105, 117,  74,   0,  45,   0,   0,  82,   0,  77,   0,   0,
+      42,  12,  78,  15,   0, 116,  85,  54, 112,   0,  19,   0,   0,
+     121,   0, 119, 115,   0,  22,  93,   0,   9,   0,   0,  70,  71,
+       0,  69,   6,   0,  48,  90, 102,   0, 118, 101,   0,   0,  44,
+       0, 103,  24,   0,  17,   0, 122,  53,  23,   0,   5, 110,  25,
+      96,   0,   0, 124, 106,  60, 123,  57,  28,  55,   0,  91,   0,
+     100,  26,   0,  99,   0,   0,   0,  95,  92,  97,  88, 109,  14,
+      39, 108,   0,  81,   0,  18,  89, 111,  32,   0, 120,  80, 113,
+      62,  46,  84,   0,   0,  94,  40,  59, 114,   0,  36,   0,   0,
+      29,   0,  86,  63,  64,   0,  20,  61,   0,  56,
   };
-  static const unsigned char aNext[121] = {
+  static const unsigned char aNext[124] = {
        0,   0,   0,   0,   4,   0,   0,   0,   0,   0,   0,   0,   0,
        0,   2,   0,   0,   0,   0,   0,   0,  13,   0,   0,   0,   0,
        0,   7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
-       0,   0,   0,   0,  33,   0,  21,   0,   0,   0,  43,   3,  47,
-       0,   0,   0,   0,  30,   0,  54,   0,  38,   0,   0,   0,   1,
-      62,   0,   0,  63,   0,  41,   0,   0,   0,   0,   0,   0,   0,
-      61,   0,   0,   0,   0,  31,  55,  16,  34,  10,   0,   0,   0,
-       0,   0,   0,   0,  11,  68,  75,   0,   8,   0, 100,  94,   0,
-     103,   0,  83,   0,  71,   0,   0, 110,  27,  37,  69,  79,   0,
-      35,  64,   0,   0,
+       0,   0,   0,   0,  33,   0,  21,   0,   0,   0,   0,   0,  50,
+       0,  43,   3,  47,   0,   0,   0,   0,  30,   0,  58,   0,  38,
+       0,   0,   0,   1,  66,   0,   0,  67,   0,  41,   0,   0,   0,
+       0,   0,   0,  49,  65,   0,   0,   0,   0,  31,  52,  16,  34,
+      10,   0,   0,   0,   0,   0,   0,   0,  11,  72,  79,   0,   8,
+       0, 104,  98,   0, 107,   0,  87,   0,  75,  51,   0,  27,  37,
+      73,  83,   0,  35,  68,   0,   0,
   };
-  static const unsigned char aLen[121] = {
+  static const unsigned char aLen[124] = {
        7,   7,   5,   4,   6,   4,   5,   3,   6,   7,   3,   6,   6,
        7,   7,   3,   8,   2,   6,   5,   4,   4,   3,  10,   4,   6,
       11,   6,   2,   7,   5,   5,   9,   6,   9,   9,   7,  10,  10,
-       4,   6,   2,   3,   9,   4,   2,   6,   5,   6,   6,   5,   6,
-       5,   5,   7,   7,   7,   3,   2,   4,   4,   7,   3,   6,   4,
-       7,   6,  12,   6,   9,   4,   6,   5,   4,   7,   6,   5,   6,
-       7,   5,   4,   5,   6,   5,   7,   3,   7,  13,   2,   2,   4,
-       6,   6,   8,   5,  17,  12,   7,   8,   8,   2,   4,   4,   4,
-       4,   4,   2,   2,   6,   5,   8,   5,   5,   8,   3,   5,   5,
-       6,   4,   9,   3,
+       4,   6,   2,   3,   9,   4,   2,   6,   5,   7,   4,   5,   7,
+       6,   6,   5,   6,   5,   5,   9,   7,   7,   3,   2,   4,   4,
+       7,   3,   6,   4,   7,   6,  12,   6,   9,   4,   6,   5,   4,
+       7,   6,   5,   6,   7,   5,   4,   5,   6,   5,   7,   3,   7,
+      13,   2,   2,   4,   6,   6,   8,   5,  17,  12,   7,   8,   8,
+       2,   4,   4,   4,   4,   4,   2,   2,   6,   5,   8,   5,   8,
+       3,   5,   5,   6,   4,   9,   3,
   };
-  static const unsigned short int aOffset[121] = {
+  static const unsigned short int aOffset[124] = {
        0,   2,   2,   8,   9,  14,  16,  20,  23,  25,  25,  29,  33,
       36,  41,  46,  48,  53,  54,  59,  62,  65,  67,  69,  78,  81,
       86,  91,  95,  96, 101, 105, 109, 117, 122, 128, 136, 142, 152,
-     159, 162, 162, 165, 167, 167, 171, 176, 179, 184, 189, 194, 197,
-     203, 206, 210, 217, 223, 223, 223, 226, 229, 233, 234, 238, 244,
-     248, 255, 261, 273, 279, 288, 290, 296, 301, 303, 310, 315, 320,
-     326, 332, 337, 341, 344, 350, 354, 361, 363, 370, 372, 374, 383,
-     387, 393, 399, 407, 412, 412, 428, 435, 442, 443, 450, 454, 458,
-     462, 466, 469, 471, 473, 479, 483, 491, 495, 500, 508, 511, 516,
-     521, 527, 531, 536,
+     159, 162, 162, 165, 167, 167, 171, 176, 179, 184, 184, 188, 192,
+     199, 204, 209, 212, 218, 221, 225, 234, 240, 240, 240, 243, 246,
+     250, 251, 255, 261, 265, 272, 278, 290, 296, 305, 307, 313, 318,
+     320, 327, 332, 337, 343, 349, 354, 358, 361, 367, 371, 378, 380,
+     387, 389, 391, 400, 404, 410, 416, 424, 429, 429, 445, 452, 459,
+     460, 467, 471, 475, 479, 483, 486, 488, 490, 496, 500, 508, 513,
+     521, 524, 529, 534, 540, 544, 549,
   };
-  static const unsigned char aCode[121] = {
+  static const unsigned char aCode[124] = {
     TK_REINDEX,    TK_INDEXED,    TK_INDEX,      TK_DESC,       TK_ESCAPE,     
     TK_EACH,       TK_CHECK,      TK_KEY,        TK_BEFORE,     TK_FOREIGN,    
     TK_FOR,        TK_IGNORE,     TK_LIKE_KW,    TK_EXPLAIN,    TK_INSTEAD,    
@@ -109540,30 +135478,38 @@ static int keywordCode(const char *z, int n){
     TK_ALTER,      TK_RAISE,      TK_EXCLUSIVE,  TK_EXISTS,     TK_SAVEPOINT,  
     TK_INTERSECT,  TK_TRIGGER,    TK_REFERENCES, TK_CONSTRAINT, TK_INTO,       
     TK_OFFSET,     TK_OF,         TK_SET,        TK_TEMP,       TK_TEMP,       
-    TK_OR,         TK_UNIQUE,     TK_QUERY,      TK_ATTACH,     TK_HAVING,     
-    TK_GROUP,      TK_UPDATE,     TK_BEGIN,      TK_JOIN_KW,    TK_RELEASE,    
-    TK_BETWEEN,    TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       
-    TK_LIKE_KW,    TK_CASCADE,    TK_ASC,        TK_DELETE,     TK_CASE,       
-    TK_COLLATE,    TK_CREATE,     TK_CTIME_KW,   TK_DETACH,     TK_IMMEDIATE,  
-    TK_JOIN,       TK_INSERT,     TK_MATCH,      TK_PLAN,       TK_ANALYZE,    
-    TK_PRAGMA,     TK_ABORT,      TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      
-    TK_WHEN,       TK_WHERE,      TK_RENAME,     TK_AFTER,      TK_REPLACE,    
-    TK_AND,        TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         
-    TK_CAST,       TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    
-    TK_CTIME_KW,   TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   
-    TK_IS,         TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    
-    TK_LIKE_KW,    TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      
-    TK_RESTRICT,   TK_JOIN_KW,    TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        
-    TK_UNION,      TK_USING,      TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  
-    TK_ALL,        
+    TK_OR,         TK_UNIQUE,     TK_QUERY,      TK_WITHOUT,    TK_WITH,       
+    TK_JOIN_KW,    TK_RELEASE,    TK_ATTACH,     TK_HAVING,     TK_GROUP,      
+    TK_UPDATE,     TK_BEGIN,      TK_JOIN_KW,    TK_RECURSIVE,  TK_BETWEEN,    
+    TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       TK_LIKE_KW,    
+    TK_CASCADE,    TK_ASC,        TK_DELETE,     TK_CASE,       TK_COLLATE,    
+    TK_CREATE,     TK_CTIME_KW,   TK_DETACH,     TK_IMMEDIATE,  TK_JOIN,       
+    TK_INSERT,     TK_MATCH,      TK_PLAN,       TK_ANALYZE,    TK_PRAGMA,     
+    TK_ABORT,      TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      TK_WHEN,       
+    TK_WHERE,      TK_RENAME,     TK_AFTER,      TK_REPLACE,    TK_AND,        
+    TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         TK_CAST,       
+    TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   
+    TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   TK_IS,         
+    TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    TK_LIKE_KW,    
+    TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   
+    TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        TK_UNION,      TK_USING,      
+    TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  TK_ALL,        
   };
-  int h, i;
-  if( n<2 ) return TK_ID;
-  h = ((charMap(z[0])*4) ^
-      (charMap(z[n-1])*3) ^
-      n) % 127;
-  for(i=((int)aHash[h])-1; i>=0; i=((int)aNext[i])-1){
-    if( aLen[i]==n && sqlite3StrNICmp(&zText[aOffset[i]],z,n)==0 ){
+  int i, j;
+  const char *zKW;
+  if( n>=2 ){
+    i = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) % 127;
+    for(i=((int)aHash[i])-1; i>=0; i=((int)aNext[i])-1){
+      if( aLen[i]!=n ) continue;
+      j = 0;
+      zKW = &zText[aOffset[i]];
+#ifdef SQLITE_ASCII
+      while( j<n && (z[j]&~0x20)==zKW[j] ){ j++; }
+#endif
+#ifdef SQLITE_EBCDIC
+      while( j<n && toupper(z[j])==zKW[j] ){ j++; }
+#endif
+      if( j<n ) continue;
       testcase( i==0 ); /* REINDEX */
       testcase( i==1 ); /* INDEXED */
       testcase( i==2 ); /* INDEX */
@@ -109612,88 +135558,94 @@ static int keywordCode(const char *z, int n){
       testcase( i==45 ); /* OR */
       testcase( i==46 ); /* UNIQUE */
       testcase( i==47 ); /* QUERY */
-      testcase( i==48 ); /* ATTACH */
-      testcase( i==49 ); /* HAVING */
-      testcase( i==50 ); /* GROUP */
-      testcase( i==51 ); /* UPDATE */
-      testcase( i==52 ); /* BEGIN */
-      testcase( i==53 ); /* INNER */
-      testcase( i==54 ); /* RELEASE */
-      testcase( i==55 ); /* BETWEEN */
-      testcase( i==56 ); /* NOTNULL */
-      testcase( i==57 ); /* NOT */
-      testcase( i==58 ); /* NO */
-      testcase( i==59 ); /* NULL */
-      testcase( i==60 ); /* LIKE */
-      testcase( i==61 ); /* CASCADE */
-      testcase( i==62 ); /* ASC */
-      testcase( i==63 ); /* DELETE */
-      testcase( i==64 ); /* CASE */
-      testcase( i==65 ); /* COLLATE */
-      testcase( i==66 ); /* CREATE */
-      testcase( i==67 ); /* CURRENT_DATE */
-      testcase( i==68 ); /* DETACH */
-      testcase( i==69 ); /* IMMEDIATE */
-      testcase( i==70 ); /* JOIN */
-      testcase( i==71 ); /* INSERT */
-      testcase( i==72 ); /* MATCH */
-      testcase( i==73 ); /* PLAN */
-      testcase( i==74 ); /* ANALYZE */
-      testcase( i==75 ); /* PRAGMA */
-      testcase( i==76 ); /* ABORT */
-      testcase( i==77 ); /* VALUES */
-      testcase( i==78 ); /* VIRTUAL */
-      testcase( i==79 ); /* LIMIT */
-      testcase( i==80 ); /* WHEN */
-      testcase( i==81 ); /* WHERE */
-      testcase( i==82 ); /* RENAME */
-      testcase( i==83 ); /* AFTER */
-      testcase( i==84 ); /* REPLACE */
-      testcase( i==85 ); /* AND */
-      testcase( i==86 ); /* DEFAULT */
-      testcase( i==87 ); /* AUTOINCREMENT */
-      testcase( i==88 ); /* TO */
-      testcase( i==89 ); /* IN */
-      testcase( i==90 ); /* CAST */
-      testcase( i==91 ); /* COLUMN */
-      testcase( i==92 ); /* COMMIT */
-      testcase( i==93 ); /* CONFLICT */
-      testcase( i==94 ); /* CROSS */
-      testcase( i==95 ); /* CURRENT_TIMESTAMP */
-      testcase( i==96 ); /* CURRENT_TIME */
-      testcase( i==97 ); /* PRIMARY */
-      testcase( i==98 ); /* DEFERRED */
-      testcase( i==99 ); /* DISTINCT */
-      testcase( i==100 ); /* IS */
-      testcase( i==101 ); /* DROP */
-      testcase( i==102 ); /* FAIL */
-      testcase( i==103 ); /* FROM */
-      testcase( i==104 ); /* FULL */
-      testcase( i==105 ); /* GLOB */
-      testcase( i==106 ); /* BY */
-      testcase( i==107 ); /* IF */
-      testcase( i==108 ); /* ISNULL */
-      testcase( i==109 ); /* ORDER */
-      testcase( i==110 ); /* RESTRICT */
-      testcase( i==111 ); /* OUTER */
-      testcase( i==112 ); /* RIGHT */
-      testcase( i==113 ); /* ROLLBACK */
-      testcase( i==114 ); /* ROW */
-      testcase( i==115 ); /* UNION */
-      testcase( i==116 ); /* USING */
-      testcase( i==117 ); /* VACUUM */
-      testcase( i==118 ); /* VIEW */
-      testcase( i==119 ); /* INITIALLY */
-      testcase( i==120 ); /* ALL */
-      return aCode[i];
-    }
-  }
-  return TK_ID;
+      testcase( i==48 ); /* WITHOUT */
+      testcase( i==49 ); /* WITH */
+      testcase( i==50 ); /* OUTER */
+      testcase( i==51 ); /* RELEASE */
+      testcase( i==52 ); /* ATTACH */
+      testcase( i==53 ); /* HAVING */
+      testcase( i==54 ); /* GROUP */
+      testcase( i==55 ); /* UPDATE */
+      testcase( i==56 ); /* BEGIN */
+      testcase( i==57 ); /* INNER */
+      testcase( i==58 ); /* RECURSIVE */
+      testcase( i==59 ); /* BETWEEN */
+      testcase( i==60 ); /* NOTNULL */
+      testcase( i==61 ); /* NOT */
+      testcase( i==62 ); /* NO */
+      testcase( i==63 ); /* NULL */
+      testcase( i==64 ); /* LIKE */
+      testcase( i==65 ); /* CASCADE */
+      testcase( i==66 ); /* ASC */
+      testcase( i==67 ); /* DELETE */
+      testcase( i==68 ); /* CASE */
+      testcase( i==69 ); /* COLLATE */
+      testcase( i==70 ); /* CREATE */
+      testcase( i==71 ); /* CURRENT_DATE */
+      testcase( i==72 ); /* DETACH */
+      testcase( i==73 ); /* IMMEDIATE */
+      testcase( i==74 ); /* JOIN */
+      testcase( i==75 ); /* INSERT */
+      testcase( i==76 ); /* MATCH */
+      testcase( i==77 ); /* PLAN */
+      testcase( i==78 ); /* ANALYZE */
+      testcase( i==79 ); /* PRAGMA */
+      testcase( i==80 ); /* ABORT */
+      testcase( i==81 ); /* VALUES */
+      testcase( i==82 ); /* VIRTUAL */
+      testcase( i==83 ); /* LIMIT */
+      testcase( i==84 ); /* WHEN */
+      testcase( i==85 ); /* WHERE */
+      testcase( i==86 ); /* RENAME */
+      testcase( i==87 ); /* AFTER */
+      testcase( i==88 ); /* REPLACE */
+      testcase( i==89 ); /* AND */
+      testcase( i==90 ); /* DEFAULT */
+      testcase( i==91 ); /* AUTOINCREMENT */
+      testcase( i==92 ); /* TO */
+      testcase( i==93 ); /* IN */
+      testcase( i==94 ); /* CAST */
+      testcase( i==95 ); /* COLUMN */
+      testcase( i==96 ); /* COMMIT */
+      testcase( i==97 ); /* CONFLICT */
+      testcase( i==98 ); /* CROSS */
+      testcase( i==99 ); /* CURRENT_TIMESTAMP */
+      testcase( i==100 ); /* CURRENT_TIME */
+      testcase( i==101 ); /* PRIMARY */
+      testcase( i==102 ); /* DEFERRED */
+      testcase( i==103 ); /* DISTINCT */
+      testcase( i==104 ); /* IS */
+      testcase( i==105 ); /* DROP */
+      testcase( i==106 ); /* FAIL */
+      testcase( i==107 ); /* FROM */
+      testcase( i==108 ); /* FULL */
+      testcase( i==109 ); /* GLOB */
+      testcase( i==110 ); /* BY */
+      testcase( i==111 ); /* IF */
+      testcase( i==112 ); /* ISNULL */
+      testcase( i==113 ); /* ORDER */
+      testcase( i==114 ); /* RESTRICT */
+      testcase( i==115 ); /* RIGHT */
+      testcase( i==116 ); /* ROLLBACK */
+      testcase( i==117 ); /* ROW */
+      testcase( i==118 ); /* UNION */
+      testcase( i==119 ); /* USING */
+      testcase( i==120 ); /* VACUUM */
+      testcase( i==121 ); /* VIEW */
+      testcase( i==122 ); /* INITIALLY */
+      testcase( i==123 ); /* ALL */
+      *pType = aCode[i];
+      break;
+    }
+  }
+  return n;
 }
 SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){
-  return keywordCode((char*)z, n);
+  int id = TK_ID;
+  keywordCode((char*)z, n, &id);
+  return id;
 }
-#define SQLITE_N_KEYWORD 121
+#define SQLITE_N_KEYWORD 124
 
 /************** End of keywordhash.h *****************************************/
 /************** Continuing where we left off in tokenize.c *******************/
@@ -109711,7 +135663,7 @@ SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){
 ** end result.
 **
 ** Ticket #1066.  the SQL standard does not allow '$' in the
-** middle of identfiers.  But many SQL implementations do. 
+** middle of identifiers.  But many SQL implementations do. 
 ** SQLite will allow '$' in identifiers for compatibility.
 ** But the feature is undocumented.
 */
@@ -109737,15 +135689,22 @@ SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[] = {
 #define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
 #endif
 
+/* Make the IdChar function accessible from ctime.c */
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }
+#endif
+
 
 /*
-** Return the length of the token that begins at z[0]. 
+** Return the length (in bytes) of the token that begins at z[0]. 
 ** Store the token type in *tokenType before returning.
 */
 SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
   int i, c;
-  switch( *z ){
-    case ' ': case '\t': case '\n': case '\f': case '\r': {
+  switch( aiClass[*z] ){  /* Switch on the character-class of the first byte
+                          ** of the token. See the comment on the CC_ defines
+                          ** above. */
+    case CC_SPACE: {
       testcase( z[0]==' ' );
       testcase( z[0]=='\t' );
       testcase( z[0]=='\n' );
@@ -109755,9 +135714,8 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
       *tokenType = TK_SPACE;
       return i;
     }
-    case '-': {
+    case CC_MINUS: {
       if( z[1]=='-' ){
-        /* IMP: R-15891-05542 -- syntax diagram for comments */
         for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
         *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
         return i;
@@ -109765,46 +135723,45 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
       *tokenType = TK_MINUS;
       return 1;
     }
-    case '(': {
+    case CC_LP: {
       *tokenType = TK_LP;
       return 1;
     }
-    case ')': {
+    case CC_RP: {
       *tokenType = TK_RP;
       return 1;
     }
-    case ';': {
+    case CC_SEMI: {
       *tokenType = TK_SEMI;
       return 1;
     }
-    case '+': {
+    case CC_PLUS: {
       *tokenType = TK_PLUS;
       return 1;
     }
-    case '*': {
+    case CC_STAR: {
       *tokenType = TK_STAR;
       return 1;
     }
-    case '/': {
+    case CC_SLASH: {
       if( z[1]!='*' || z[2]==0 ){
         *tokenType = TK_SLASH;
         return 1;
       }
-      /* IMP: R-15891-05542 -- syntax diagram for comments */
       for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
       if( c ) i++;
       *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
       return i;
     }
-    case '%': {
+    case CC_PERCENT: {
       *tokenType = TK_REM;
       return 1;
     }
-    case '=': {
+    case CC_EQ: {
       *tokenType = TK_EQ;
       return 1 + (z[1]=='=');
     }
-    case '<': {
+    case CC_LT: {
       if( (c=z[1])=='=' ){
         *tokenType = TK_LE;
         return 2;
@@ -109819,7 +135776,7 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
         return 1;
       }
     }
-    case '>': {
+    case CC_GT: {
       if( (c=z[1])=='=' ){
         *tokenType = TK_GE;
         return 2;
@@ -109831,16 +135788,16 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
         return 1;
       }
     }
-    case '!': {
+    case CC_BANG: {
       if( z[1]!='=' ){
         *tokenType = TK_ILLEGAL;
-        return 2;
+        return 1;
       }else{
         *tokenType = TK_NE;
         return 2;
       }
     }
-    case '|': {
+    case CC_PIPE: {
       if( z[1]!='|' ){
         *tokenType = TK_BITOR;
         return 1;
@@ -109849,21 +135806,19 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
         return 2;
       }
     }
-    case ',': {
+    case CC_COMMA: {
       *tokenType = TK_COMMA;
       return 1;
     }
-    case '&': {
+    case CC_AND: {
       *tokenType = TK_BITAND;
       return 1;
     }
-    case '~': {
+    case CC_TILDA: {
       *tokenType = TK_BITNOT;
       return 1;
     }
-    case '`':
-    case '\'':
-    case '"': {
+    case CC_QUOTE: {
       int delim = z[0];
       testcase( delim=='`' );
       testcase( delim=='\'' );
@@ -109888,7 +135843,7 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
         return i;
       }
     }
-    case '.': {
+    case CC_DOT: {
 #ifndef SQLITE_OMIT_FLOATING_POINT
       if( !sqlite3Isdigit(z[1]) )
 #endif
@@ -109899,13 +135854,18 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
       /* If the next character is a digit, this is a floating point
       ** number that begins with ".".  Fall thru into the next case */
     }
-    case '0': case '1': case '2': case '3': case '4':
-    case '5': case '6': case '7': case '8': case '9': {
+    case CC_DIGIT: {
       testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
       testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
       testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
       testcase( z[0]=='9' );
       *tokenType = TK_INTEGER;
+#ifndef SQLITE_OMIT_HEX_INTEGER
+      if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
+        for(i=3; sqlite3Isxdigit(z[i]); i++){}
+        return i;
+      }
+#endif
       for(i=0; sqlite3Isdigit(z[i]); i++){}
 #ifndef SQLITE_OMIT_FLOATING_POINT
       if( z[i]=='.' ){
@@ -109929,34 +135889,21 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
       }
       return i;
     }
-    case '[': {
+    case CC_QUOTE2: {
       for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
       *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
       return i;
     }
-    case '?': {
+    case CC_VARNUM: {
       *tokenType = TK_VARIABLE;
       for(i=1; sqlite3Isdigit(z[i]); i++){}
       return i;
     }
-    case '#': {
-      for(i=1; sqlite3Isdigit(z[i]); i++){}
-      if( i>1 ){
-        /* Parameters of the form #NNN (where NNN is a number) are used
-        ** internally by sqlite3NestedParse.  */
-        *tokenType = TK_REGISTER;
-        return i;
-      }
-      /* Fall through into the next case if the '#' is not followed by
-      ** a digit. Try to match #AAAA where AAAA is a parameter name. */
-    }
-#ifndef SQLITE_OMIT_TCL_VARIABLE
-    case '$':
-#endif
-    case '@':  /* For compatibility with MS SQL Server */
-    case ':': {
+    case CC_DOLLAR:
+    case CC_VARALPHA: {
       int n = 0;
-      testcase( z[0]=='$' );  testcase( z[0]=='@' );  testcase( z[0]==':' );
+      testcase( z[0]=='$' );  testcase( z[0]=='@' );
+      testcase( z[0]==':' );  testcase( z[0]=='#' );
       *tokenType = TK_VARIABLE;
       for(i=1; (c=z[i])!=0; i++){
         if( IdChar(c) ){
@@ -109982,8 +135929,20 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
       if( n==0 ) *tokenType = TK_ILLEGAL;
       return i;
     }
+    case CC_KYWD: {
+      for(i=1; aiClass[z[i]]<=CC_KYWD; i++){}
+      if( IdChar(z[i]) ){
+        /* This token started out using characters that can appear in keywords,
+        ** but z[i] is a character not allowed within keywords, so this must
+        ** be an identifier instead */
+        i++;
+        break;
+      }
+      *tokenType = TK_ID;
+      return keywordCode((char*)z, i, tokenType);
+    }
+    case CC_X: {
 #ifndef SQLITE_OMIT_BLOB_LITERAL
-    case 'x': case 'X': {
       testcase( z[0]=='x' ); testcase( z[0]=='X' );
       if( z[1]=='\'' ){
         *tokenType = TK_BLOB;
@@ -109995,20 +135954,22 @@ SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
         if( z[i] ) i++;
         return i;
       }
-      /* Otherwise fall through to the next case */
-    }
 #endif
+      /* If it is not a BLOB literal, then it must be an ID, since no
+      ** SQL keywords start with the letter 'x'.  Fall through */
+    }
+    case CC_ID: {
+      i = 1;
+      break;
+    }
     default: {
-      if( !IdChar(*z) ){
-        break;
-      }
-      for(i=1; IdChar(z[i]); i++){}
-      *tokenType = keywordCode((char*)z, i);
-      return i;
+      *tokenType = TK_ILLEGAL;
+      return 1;
     }
   }
-  *tokenType = TK_ILLEGAL;
-  return 1;
+  while( IdChar(z[i]) ){ i++; }
+  *tokenType = TK_ID;
+  return i;
 }
 
 /*
@@ -110024,32 +135985,30 @@ SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzEr
   void *pEngine;                  /* The LEMON-generated LALR(1) parser */
   int tokenType;                  /* type of the next token */
   int lastTokenParsed = -1;       /* type of the previous token */
-  u8 enableLookaside;             /* Saved value of db->lookaside.bEnabled */
   sqlite3 *db = pParse->db;       /* The database connection */
   int mxSqlLen;                   /* Max length of an SQL string */
 
-
+  assert( zSql!=0 );
   mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
-  if( db->activeVdbeCnt==0 ){
+  if( db->nVdbeActive==0 ){
     db->u1.isInterrupted = 0;
   }
   pParse->rc = SQLITE_OK;
   pParse->zTail = zSql;
   i = 0;
   assert( pzErrMsg!=0 );
-  pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
+  /* sqlite3ParserTrace(stdout, "parser: "); */
+  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
   if( pEngine==0 ){
-    db->mallocFailed = 1;
-    return SQLITE_NOMEM;
+    sqlite3OomFault(db);
+    return SQLITE_NOMEM_BKPT;
   }
   assert( pParse->pNewTable==0 );
   assert( pParse->pNewTrigger==0 );
   assert( pParse->nVar==0 );
   assert( pParse->nzVar==0 );
   assert( pParse->azVar==0 );
-  enableLookaside = db->lookaside.bEnabled;
-  if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
-  while( !db->mallocFailed && zSql[i]!=0 ){
+  while( zSql[i]!=0 ){
     assert( i>=0 );
     pParse->sLastToken.z = &zSql[i];
     pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
@@ -110058,56 +136017,47 @@ SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzEr
       pParse->rc = SQLITE_TOOBIG;
       break;
     }
-    switch( tokenType ){
-      case TK_SPACE: {
-        if( db->u1.isInterrupted ){
-          sqlite3ErrorMsg(pParse, "interrupt");
-          pParse->rc = SQLITE_INTERRUPT;
-          goto abort_parse;
-        }
+    if( tokenType>=TK_SPACE ){
+      assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
+      if( db->u1.isInterrupted ){
+        pParse->rc = SQLITE_INTERRUPT;
         break;
       }
-      case TK_ILLEGAL: {
-        sqlite3DbFree(db, *pzErrMsg);
-        *pzErrMsg = sqlite3MPrintf(db, "unrecognized token: \"%T\"",
+      if( tokenType==TK_ILLEGAL ){
+        sqlite3ErrorMsg(pParse, "unrecognized token: \"%T\"",
                         &pParse->sLastToken);
-        nErr++;
-        goto abort_parse;
-      }
-      case TK_SEMI: {
-        pParse->zTail = &zSql[i];
-        /* Fall thru into the default case */
-      }
-      default: {
-        sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
-        lastTokenParsed = tokenType;
-        if( pParse->rc!=SQLITE_OK ){
-          goto abort_parse;
-        }
         break;
       }
+    }else{
+      sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
+      lastTokenParsed = tokenType;
+      if( pParse->rc!=SQLITE_OK || db->mallocFailed ) break;
     }
   }
-abort_parse:
-  if( zSql[i]==0 && nErr==0 && pParse->rc==SQLITE_OK ){
+  assert( nErr==0 );
+  pParse->zTail = &zSql[i];
+  if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
+    assert( zSql[i]==0 );
     if( lastTokenParsed!=TK_SEMI ){
       sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
-      pParse->zTail = &zSql[i];
     }
-    sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
+    if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
+      sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
+    }
   }
 #ifdef YYTRACKMAXSTACKDEPTH
-  sqlite3StatusSet(SQLITE_STATUS_PARSER_STACK,
+  sqlite3_mutex_enter(sqlite3MallocMutex());
+  sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
       sqlite3ParserStackPeak(pEngine)
   );
+  sqlite3_mutex_leave(sqlite3MallocMutex());
 #endif /* YYDEBUG */
   sqlite3ParserFree(pEngine, sqlite3_free);
-  db->lookaside.bEnabled = enableLookaside;
   if( db->mallocFailed ){
-    pParse->rc = SQLITE_NOMEM;
+    pParse->rc = SQLITE_NOMEM_BKPT;
   }
   if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
-    sqlite3SetString(&pParse->zErrMsg, db, "%s", sqlite3ErrStr(pParse->rc));
+    pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
   }
   assert( pzErrMsg!=0 );
   if( pParse->zErrMsg ){
@@ -110139,10 +136089,10 @@ abort_parse:
     sqlite3DeleteTable(db, pParse->pNewTable);
   }
 
+  if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);
   sqlite3DeleteTrigger(db, pParse->pNewTrigger);
   for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
   sqlite3DbFree(db, pParse->azVar);
-  sqlite3DbFree(db, pParse->aAlias);
   while( pParse->pAinc ){
     AutoincInfo *p = pParse->pAinc;
     pParse->pAinc = p->pNext;
@@ -110153,9 +136103,7 @@ abort_parse:
     pParse->pZombieTab = p->pNextZombie;
     sqlite3DeleteTable(db, p);
   }
-  if( nErr>0 && pParse->rc==SQLITE_OK ){
-    pParse->rc = SQLITE_ERROR;
-  }
+  assert( nErr==0 || pParse->rc!=SQLITE_OK );
   return nErr;
 }
 
@@ -110179,6 +136127,7 @@ abort_parse:
 ** separating it out, the code will be automatically omitted from
 ** static links that do not use it.
 */
+/* #include "sqliteInt.h" */
 #ifndef SQLITE_OMIT_COMPLETE
 
 /*
@@ -110232,7 +136181,7 @@ SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
 **                 a statement.
 **
 **   (4) CREATE    The keyword CREATE has been seen at the beginning of a
-**                 statement, possibly preceeded by EXPLAIN and/or followed by
+**                 statement, possibly preceded by EXPLAIN and/or followed by
 **                 TEMP or TEMPORARY
 **
 **   (5) TRIGGER   We are in the middle of a trigger definition that must be
@@ -110242,7 +136191,7 @@ SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
 **                 the end of a trigger definition.
 **
 **   (7) END       We've seen the ";END" of the ";END;" that occurs at the end
-**                 of a trigger difinition.
+**                 of a trigger definition.
 **
 ** Transitions between states above are determined by tokens extracted
 ** from the input.  The following tokens are significant:
@@ -110263,7 +136212,7 @@ SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
 ** to recognize the end of a trigger can be omitted.  All we have to do
 ** is look for a semicolon that is not part of an string or comment.
 */
-SQLITE_API int sqlite3_complete(const char *zSql){
+SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *zSql){
   u8 state = 0;   /* Current state, using numbers defined in header comment */
   u8 token;       /* Value of the next token */
 
@@ -110285,7 +136234,7 @@ SQLITE_API int sqlite3_complete(const char *zSql){
   };
 #else
   /* If triggers are not supported by this compile then the statement machine
-  ** used to detect the end of a statement is much simplier
+  ** used to detect the end of a statement is much simpler
   */
   static const u8 trans[3][3] = {
                      /* Token:           */
@@ -110296,6 +136245,13 @@ SQLITE_API int sqlite3_complete(const char *zSql){
   };
 #endif /* SQLITE_OMIT_TRIGGER */
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( zSql==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+
   while( *zSql ){
     switch( *zSql ){
       case ';': {  /* A semicolon */
@@ -110421,10 +136377,10 @@ SQLITE_API int sqlite3_complete(const char *zSql){
 ** above, except that the parameter is required to be UTF-16 encoded, not
 ** UTF-8.
 */
-SQLITE_API int sqlite3_complete16(const void *zSql){
+SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *zSql){
   sqlite3_value *pVal;
   char const *zSql8;
-  int rc = SQLITE_NOMEM;
+  int rc;
 
 #ifndef SQLITE_OMIT_AUTOINIT
   rc = sqlite3_initialize();
@@ -110436,10 +136392,10 @@ SQLITE_API int sqlite3_complete16(const void *zSql){
   if( zSql8 ){
     rc = sqlite3_complete(zSql8);
   }else{
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
   sqlite3ValueFree(pVal);
-  return sqlite3ApiExit(0, rc);
+  return rc & 0xff;
 }
 #endif /* SQLITE_OMIT_UTF16 */
 #endif /* SQLITE_OMIT_COMPLETE */
@@ -110462,6 +136418,7 @@ SQLITE_API int sqlite3_complete16(const void *zSql){
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 */
+/* #include "sqliteInt.h" */
 
 #ifdef SQLITE_ENABLE_FTS3
 /************** Include fts3.h in the middle of main.c ***********************/
@@ -110481,6 +136438,7 @@ SQLITE_API int sqlite3_complete16(const void *zSql){
 ** This header file is used by programs that want to link against the
 ** FTS3 library.  All it does is declare the sqlite3Fts3Init() interface.
 */
+/* #include "sqlite3.h" */
 
 #if 0
 extern "C" {
@@ -110513,6 +136471,7 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);
 ** This header file is used by programs that want to link against the
 ** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.
 */
+/* #include "sqlite3.h" */
 
 #if 0
 extern "C" {
@@ -110545,6 +136504,7 @@ SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db);
 ** This header file is used by programs that want to link against the
 ** ICU extension.  All it does is declare the sqlite3IcuInit() interface.
 */
+/* #include "sqlite3.h" */
 
 #if 0
 extern "C" {
@@ -110560,6 +136520,12 @@ SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);
 /************** End of sqliteicu.h *******************************************/
 /************** Continuing where we left off in main.c ***********************/
 #endif
+#ifdef SQLITE_ENABLE_JSON1
+SQLITE_PRIVATE int sqlite3Json1Init(sqlite3*);
+#endif
+#ifdef SQLITE_ENABLE_FTS5
+SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3*);
+#endif
 
 #ifndef SQLITE_AMALGAMATION
 /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
@@ -110571,24 +136537,36 @@ SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
 /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
 ** a pointer to the to the sqlite3_version[] string constant. 
 */
-SQLITE_API const char *sqlite3_libversion(void){ return sqlite3_version; }
+SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void){ return sqlite3_version; }
 
 /* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
 ** pointer to a string constant whose value is the same as the
 ** SQLITE_SOURCE_ID C preprocessor macro. 
 */
-SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
+SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
 
 /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
 ** returns an integer equal to SQLITE_VERSION_NUMBER.
 */
-SQLITE_API int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
+SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
 
-/* IMPLEMENTATION-OF: R-54823-41343 The sqlite3_threadsafe() function returns
-** zero if and only if SQLite was compiled mutexing code omitted due to
+/* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
+** zero if and only if SQLite was compiled with mutexing code omitted due to
 ** the SQLITE_THREADSAFE compile-time option being set to 0.
 */
-SQLITE_API int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+
+/*
+** When compiling the test fixture or with debugging enabled (on Win32),
+** this variable being set to non-zero will cause OSTRACE macros to emit
+** extra diagnostic information.
+*/
+#ifdef SQLITE_HAVE_OS_TRACE
+# ifndef SQLITE_DEBUG_OS_TRACE
+#   define SQLITE_DEBUG_OS_TRACE 0
+# endif
+  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
+#endif
 
 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
 /*
@@ -110597,7 +136575,7 @@ SQLITE_API int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
 ** I/O active are written using this function.  These messages
 ** are intended for debugging activity only.
 */
-SQLITE_PRIVATE void (*sqlite3IoTrace)(const char*, ...) = 0;
+SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
 #endif
 
 /*
@@ -110610,6 +136588,15 @@ SQLITE_PRIVATE void (*sqlite3IoTrace)(const char*, ...) = 0;
 SQLITE_API char *sqlite3_temp_directory = 0;
 
 /*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** all database files specified with a relative pathname.
+**
+** See also the "PRAGMA data_store_directory" SQL command.
+*/
+SQLITE_API char *sqlite3_data_directory = 0;
+
+/*
 ** Initialize SQLite.  
 **
 ** This routine must be called to initialize the memory allocation,
@@ -110640,9 +136627,12 @@ SQLITE_API char *sqlite3_temp_directory = 0;
 **    *  Recursive calls to this routine from thread X return immediately
 **       without blocking.
 */
-SQLITE_API int sqlite3_initialize(void){
+SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void){
   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
   int rc;                                      /* Result code */
+#ifdef SQLITE_EXTRA_INIT
+  int bRunExtraInit = 0;                       /* Extra initialization needed */
+#endif
 
 #ifdef SQLITE_OMIT_WSD
   rc = sqlite3_wsd_init(4096, 24);
@@ -110651,6 +136641,11 @@ SQLITE_API int sqlite3_initialize(void){
   }
 #endif
 
+  /* If the following assert() fails on some obscure processor/compiler
+  ** combination, the work-around is to set the correct pointer
+  ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
+  assert( SQLITE_PTRSIZE==sizeof(char*) );
+
   /* If SQLite is already completely initialized, then this call
   ** to sqlite3_initialize() should be a no-op.  But the initialization
   ** must be complete.  So isInit must not be set until the very end
@@ -110687,7 +136682,7 @@ SQLITE_API int sqlite3_initialize(void){
       sqlite3GlobalConfig.pInitMutex =
            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
-        rc = SQLITE_NOMEM;
+        rc = SQLITE_NOMEM_BKPT;
       }
     }
   }
@@ -110718,10 +136713,15 @@ SQLITE_API int sqlite3_initialize(void){
   */
   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
-    FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
     sqlite3GlobalConfig.inProgress = 1;
-    memset(pHash, 0, sizeof(sqlite3GlobalFunctions));
-    sqlite3RegisterGlobalFunctions();
+#ifdef SQLITE_ENABLE_SQLLOG
+    {
+      extern void sqlite3_init_sqllog(void);
+      sqlite3_init_sqllog();
+    }
+#endif
+    memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
+    sqlite3RegisterBuiltinFunctions();
     if( sqlite3GlobalConfig.isPCacheInit==0 ){
       rc = sqlite3PcacheInitialize();
     }
@@ -110733,6 +136733,9 @@ SQLITE_API int sqlite3_initialize(void){
       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
       sqlite3GlobalConfig.isInit = 1;
+#ifdef SQLITE_EXTRA_INIT
+      bRunExtraInit = 1;
+#endif
     }
     sqlite3GlobalConfig.inProgress = 0;
   }
@@ -110773,9 +136776,9 @@ SQLITE_API int sqlite3_initialize(void){
   ** compile-time option.
   */
 #ifdef SQLITE_EXTRA_INIT
-  if( rc==SQLITE_OK && sqlite3GlobalConfig.isInit ){
-    int SQLITE_EXTRA_INIT(void);
-    rc = SQLITE_EXTRA_INIT();
+  if( bRunExtraInit ){
+    int SQLITE_EXTRA_INIT(const char*);
+    rc = SQLITE_EXTRA_INIT(0);
   }
 #endif
 
@@ -110790,8 +136793,19 @@ SQLITE_API int sqlite3_initialize(void){
 ** on when SQLite is already shut down.  If SQLite is already shut down
 ** when this routine is invoked, then this routine is a harmless no-op.
 */
-SQLITE_API int sqlite3_shutdown(void){
+SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void){
+#ifdef SQLITE_OMIT_WSD
+  int rc = sqlite3_wsd_init(4096, 24);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+#endif
+
   if( sqlite3GlobalConfig.isInit ){
+#ifdef SQLITE_EXTRA_SHUTDOWN
+    void SQLITE_EXTRA_SHUTDOWN(void);
+    SQLITE_EXTRA_SHUTDOWN();
+#endif
     sqlite3_os_end();
     sqlite3_reset_auto_extension();
     sqlite3GlobalConfig.isInit = 0;
@@ -110803,6 +136817,18 @@ SQLITE_API int sqlite3_shutdown(void){
   if( sqlite3GlobalConfig.isMallocInit ){
     sqlite3MallocEnd();
     sqlite3GlobalConfig.isMallocInit = 0;
+
+#ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
+    /* The heap subsystem has now been shutdown and these values are supposed
+    ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
+    ** which would rely on that heap subsystem; therefore, make sure these
+    ** values cannot refer to heap memory that was just invalidated when the
+    ** heap subsystem was shutdown.  This is only done if the current call to
+    ** this function resulted in the heap subsystem actually being shutdown.
+    */
+    sqlite3_data_directory = 0;
+    sqlite3_temp_directory = 0;
+#endif
   }
   if( sqlite3GlobalConfig.isMutexInit ){
     sqlite3MutexEnd();
@@ -110821,7 +136847,7 @@ SQLITE_API int sqlite3_shutdown(void){
 ** threadsafe.  Failure to heed these warnings can lead to unpredictable
 ** behavior.
 */
-SQLITE_API int sqlite3_config(int op, ...){
+SQLITE_API int SQLITE_CDECL sqlite3_config(int op, ...){
   va_list ap;
   int rc = SQLITE_OK;
 
@@ -110833,33 +136859,43 @@ SQLITE_API int sqlite3_config(int op, ...){
   switch( op ){
 
     /* Mutex configuration options are only available in a threadsafe
-    ** compile. 
+    ** compile.
     */
-#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
     case SQLITE_CONFIG_SINGLETHREAD: {
-      /* Disable all mutexing */
-      sqlite3GlobalConfig.bCoreMutex = 0;
-      sqlite3GlobalConfig.bFullMutex = 0;
+      /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
+      ** Single-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
       break;
     }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
     case SQLITE_CONFIG_MULTITHREAD: {
-      /* Disable mutexing of database connections */
-      /* Enable mutexing of core data structures */
-      sqlite3GlobalConfig.bCoreMutex = 1;
-      sqlite3GlobalConfig.bFullMutex = 0;
+      /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
+      ** Multi-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
       break;
     }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
     case SQLITE_CONFIG_SERIALIZED: {
-      /* Enable all mutexing */
-      sqlite3GlobalConfig.bCoreMutex = 1;
-      sqlite3GlobalConfig.bFullMutex = 1;
+      /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
+      ** Serialized. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
       break;
     }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
     case SQLITE_CONFIG_MUTEX: {
       /* Specify an alternative mutex implementation */
       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
       break;
     }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
     case SQLITE_CONFIG_GETMUTEX: {
       /* Retrieve the current mutex implementation */
       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
@@ -110867,55 +136903,102 @@ SQLITE_API int sqlite3_config(int op, ...){
     }
 #endif
 
-
     case SQLITE_CONFIG_MALLOC: {
-      /* Specify an alternative malloc implementation */
+      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The argument specifies alternative
+      ** low-level memory allocation routines to be used in place of the memory
+      ** allocation routines built into SQLite. */
       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
       break;
     }
     case SQLITE_CONFIG_GETMALLOC: {
-      /* Retrieve the current malloc() implementation */
+      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
+      ** filled with the currently defined memory allocation routines. */
       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
       break;
     }
     case SQLITE_CONFIG_MEMSTATUS: {
-      /* Enable or disable the malloc status collection */
+      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
+      ** single argument of type int, interpreted as a boolean, which enables
+      ** or disables the collection of memory allocation statistics. */
       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
       break;
     }
     case SQLITE_CONFIG_SCRATCH: {
-      /* Designate a buffer for scratch memory space */
+      /* EVIDENCE-OF: R-08404-60887 There are three arguments to
+      ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
+      ** which the scratch allocations will be drawn, the size of each scratch
+      ** allocation (sz), and the maximum number of scratch allocations (N). */
       sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
       sqlite3GlobalConfig.szScratch = va_arg(ap, int);
       sqlite3GlobalConfig.nScratch = va_arg(ap, int);
       break;
     }
     case SQLITE_CONFIG_PAGECACHE: {
-      /* Designate a buffer for page cache memory space */
+      /* EVIDENCE-OF: R-18761-36601 There are three arguments to
+      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
+      ** the size of each page cache line (sz), and the number of cache lines
+      ** (N). */
       sqlite3GlobalConfig.pPage = va_arg(ap, void*);
       sqlite3GlobalConfig.szPage = va_arg(ap, int);
       sqlite3GlobalConfig.nPage = va_arg(ap, int);
       break;
     }
+    case SQLITE_CONFIG_PCACHE_HDRSZ: {
+      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
+      ** a single parameter which is a pointer to an integer and writes into
+      ** that integer the number of extra bytes per page required for each page
+      ** in SQLITE_CONFIG_PAGECACHE. */
+      *va_arg(ap, int*) = 
+          sqlite3HeaderSizeBtree() +
+          sqlite3HeaderSizePcache() +
+          sqlite3HeaderSizePcache1();
+      break;
+    }
 
     case SQLITE_CONFIG_PCACHE: {
-      /* Specify an alternative page cache implementation */
-      sqlite3GlobalConfig.pcache = *va_arg(ap, sqlite3_pcache_methods*);
+      /* no-op */
       break;
     }
-
     case SQLITE_CONFIG_GETPCACHE: {
-      if( sqlite3GlobalConfig.pcache.xInit==0 ){
+      /* now an error */
+      rc = SQLITE_ERROR;
+      break;
+    }
+
+    case SQLITE_CONFIG_PCACHE2: {
+      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. This object specifies the interface to a custom page cache
+      ** implementation. */
+      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
+      break;
+    }
+    case SQLITE_CONFIG_GETPCACHE2: {
+      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. SQLite copies of the current page cache implementation into
+      ** that object. */
+      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
         sqlite3PCacheSetDefault();
       }
-      *va_arg(ap, sqlite3_pcache_methods*) = sqlite3GlobalConfig.pcache;
+      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
       break;
     }
 
+/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
+** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
+** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
 #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
     case SQLITE_CONFIG_HEAP: {
-      /* Designate a buffer for heap memory space */
+      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
+      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
+      ** number of bytes in the memory buffer, and the minimum allocation size.
+      */
       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
       sqlite3GlobalConfig.nHeap = va_arg(ap, int);
       sqlite3GlobalConfig.mnReq = va_arg(ap, int);
@@ -110928,17 +137011,19 @@ SQLITE_API int sqlite3_config(int op, ...){
       }
 
       if( sqlite3GlobalConfig.pHeap==0 ){
-        /* If the heap pointer is NULL, then restore the malloc implementation
-        ** back to NULL pointers too.  This will cause the malloc to go
-        ** back to its default implementation when sqlite3_initialize() is
-        ** run.
+        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
+        ** is NULL, then SQLite reverts to using its default memory allocator
+        ** (the system malloc() implementation), undoing any prior invocation of
+        ** SQLITE_CONFIG_MALLOC.
+        **
+        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
+        ** revert to its default implementation when sqlite3_initialize() is run
         */
         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
       }else{
-        /* The heap pointer is not NULL, then install one of the
-        ** mem5.c/mem3.c methods. If neither ENABLE_MEMSYS3 nor
-        ** ENABLE_MEMSYS5 is defined, return an error.
-        */
+        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
+        ** alternative memory allocator is engaged to handle all of SQLites
+        ** memory allocation needs. */
 #ifdef SQLITE_ENABLE_MEMSYS3
         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
 #endif
@@ -110956,7 +137041,7 @@ SQLITE_API int sqlite3_config(int op, ...){
       break;
     }
     
-    /* Record a pointer to the logger funcction and its first argument.
+    /* Record a pointer to the logger function and its first argument.
     ** The default is NULL.  Logging is disabled if the function pointer is
     ** NULL.
     */
@@ -110971,11 +137056,83 @@ SQLITE_API int sqlite3_config(int op, ...){
       break;
     }
 
+    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
+    ** can be changed at start-time using the
+    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
+    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
+    */
     case SQLITE_CONFIG_URI: {
+      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
+      ** argument of type int. If non-zero, then URI handling is globally
+      ** enabled. If the parameter is zero, then URI handling is globally
+      ** disabled. */
       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
       break;
     }
 
+    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
+      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
+      ** option takes a single integer argument which is interpreted as a
+      ** boolean in order to enable or disable the use of covering indices for
+      ** full table scans in the query optimizer. */
+      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
+      break;
+    }
+
+#ifdef SQLITE_ENABLE_SQLLOG
+    case SQLITE_CONFIG_SQLLOG: {
+      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
+      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
+      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_MMAP_SIZE: {
+      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
+      ** integer (sqlite3_int64) values that are the default mmap size limit
+      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
+      ** mmap size limit. */
+      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
+      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
+      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
+      ** negative, then that argument is changed to its compile-time default.
+      **
+      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
+      ** silently truncated if necessary so that it does not exceed the
+      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
+      ** compile-time option.
+      */
+      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
+        mxMmap = SQLITE_MAX_MMAP_SIZE;
+      }
+      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
+      if( szMmap>mxMmap) szMmap = mxMmap;
+      sqlite3GlobalConfig.mxMmap = mxMmap;
+      sqlite3GlobalConfig.szMmap = szMmap;
+      break;
+    }
+
+#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
+    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
+      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
+      ** unsigned integer value that specifies the maximum size of the created
+      ** heap. */
+      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_PMASZ: {
+      sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
+      break;
+    }
+
+    case SQLITE_CONFIG_STMTJRNL_SPILL: {
+      sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
+      break;
+    }
+
     default: {
       rc = SQLITE_ERROR;
       break;
@@ -110997,6 +137154,7 @@ SQLITE_API int sqlite3_config(int op, ...){
 ** the lookaside memory.
 */
 static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
+#ifndef SQLITE_OMIT_LOOKASIDE
   void *pStart;
   if( db->lookaside.nOut ){
     return SQLITE_BUSY;
@@ -111008,21 +137166,21 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
   if( db->lookaside.bMalloced ){
     sqlite3_free(db->lookaside.pStart);
   }
-  /* The size of a lookaside slot needs to be larger than a pointer
-  ** to be useful.
+  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
+  ** than a pointer to be useful.
   */
+  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
   if( cnt<0 ) cnt = 0;
   if( sz==0 || cnt==0 ){
     sz = 0;
     pStart = 0;
   }else if( pBuf==0 ){
-    sz = ROUNDDOWN8(sz); /* IMP: R-33038-09382 */
     sqlite3BeginBenignMalloc();
     pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
     sqlite3EndBenignMalloc();
+    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
   }else{
-    sz = ROUNDDOWN8(sz); /* IMP: R-33038-09382 */
     pStart = pBuf;
   }
   db->lookaside.pStart = pStart;
@@ -111039,27 +137197,89 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
       p = (LookasideSlot*)&((u8*)p)[sz];
     }
     db->lookaside.pEnd = p;
-    db->lookaside.bEnabled = 1;
+    db->lookaside.bDisable = 0;
     db->lookaside.bMalloced = pBuf==0 ?1:0;
   }else{
-    db->lookaside.pEnd = 0;
-    db->lookaside.bEnabled = 0;
+    db->lookaside.pStart = db;
+    db->lookaside.pEnd = db;
+    db->lookaside.bDisable = 1;
     db->lookaside.bMalloced = 0;
   }
+#endif /* SQLITE_OMIT_LOOKASIDE */
   return SQLITE_OK;
 }
 
 /*
 ** Return the mutex associated with a database connection.
 */
-SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
+SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return db->mutex;
 }
 
 /*
+** Free up as much memory as we can from the given database
+** connection.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3 *db){
+  int i;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      sqlite3PagerShrink(pPager);
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Flush any dirty pages in the pager-cache for any attached database
+** to disk.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3 *db){
+  int i;
+  int rc = SQLITE_OK;
+  int bSeenBusy = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      rc = sqlite3PagerFlush(pPager);
+      if( rc==SQLITE_BUSY ){
+        bSeenBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
+}
+
+/*
 ** Configuration settings for an individual database connection
 */
-SQLITE_API int sqlite3_db_config(sqlite3 *db, int op, ...){
+SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3 *db, int op, ...){
   va_list ap;
   int rc;
   va_start(ap, op);
@@ -111076,8 +137296,10 @@ SQLITE_API int sqlite3_db_config(sqlite3 *db, int op, ...){
         int op;      /* The opcode */
         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
       } aFlagOp[] = {
-        { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
-        { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
+        { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
+        { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
+        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
+        { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
       };
       unsigned int i;
       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
@@ -111131,13 +137353,20 @@ static int binCollFunc(
 ){
   int rc, n;
   n = nKey1<nKey2 ? nKey1 : nKey2;
+  /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
+  ** strings byte by byte using the memcmp() function from the standard C
+  ** library. */
   rc = memcmp(pKey1, pKey2, n);
   if( rc==0 ){
     if( padFlag
      && allSpaces(((char*)pKey1)+n, nKey1-n)
      && allSpaces(((char*)pKey2)+n, nKey2-n)
     ){
-      /* Leave rc unchanged at 0 */
+      /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
+      ** spaces at the end of either string do not change the result. In other
+      ** words, strings will compare equal to one another as long as they
+      ** differ only in the number of spaces at the end.
+      */
     }else{
       rc = nKey1 - nKey2;
     }
@@ -111148,7 +137377,7 @@ static int binCollFunc(
 /*
 ** Another built-in collating sequence: NOCASE. 
 **
-** This collating sequence is intended to be used for "case independant
+** This collating sequence is intended to be used for "case independent
 ** comparison". SQLite's knowledge of upper and lower case equivalents
 ** extends only to the 26 characters used in the English language.
 **
@@ -111171,21 +137400,39 @@ static int nocaseCollatingFunc(
 /*
 ** Return the ROWID of the most recent insert
 */
-SQLITE_API sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
+SQLITE_API sqlite_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return db->lastRowid;
 }
 
 /*
 ** Return the number of changes in the most recent call to sqlite3_exec().
 */
-SQLITE_API int sqlite3_changes(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return db->nChange;
 }
 
 /*
 ** Return the number of changes since the database handle was opened.
 */
-SQLITE_API int sqlite3_total_changes(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return db->nTotalChange;
 }
 
@@ -111212,7 +137459,7 @@ SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *db){
 ** with SQLITE_ANY as the encoding.
 */
 static void functionDestroy(sqlite3 *db, FuncDef *p){
-  FuncDestructor *pDestructor = p->pDestructor;
+  FuncDestructor *pDestructor = p->u.pDestructor;
   if( pDestructor ){
     pDestructor->nRef--;
     if( pDestructor->nRef==0 ){
@@ -111223,24 +137470,72 @@ static void functionDestroy(sqlite3 *db, FuncDef *p){
 }
 
 /*
-** Close an existing SQLite database
+** Disconnect all sqlite3_vtab objects that belong to database connection
+** db. This is called when db is being closed.
 */
-SQLITE_API int sqlite3_close(sqlite3 *db){
-  HashElem *i;                    /* Hash table iterator */
+static void disconnectAllVtab(sqlite3 *db){
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  int i;
+  HashElem *p;
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Schema *pSchema = db->aDb[i].pSchema;
+    if( db->aDb[i].pSchema ){
+      for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
+        Table *pTab = (Table *)sqliteHashData(p);
+        if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
+      }
+    }
+  }
+  for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
+    Module *pMod = (Module *)sqliteHashData(p);
+    if( pMod->pEpoTab ){
+      sqlite3VtabDisconnect(db, pMod->pEpoTab);
+    }
+  }
+  sqlite3VtabUnlockList(db);
+  sqlite3BtreeLeaveAll(db);
+#else
+  UNUSED_PARAMETER(db);
+#endif
+}
+
+/*
+** Return TRUE if database connection db has unfinalized prepared
+** statements or unfinished sqlite3_backup objects.  
+*/
+static int connectionIsBusy(sqlite3 *db){
   int j;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->pVdbe ) return 1;
+  for(j=0; j<db->nDb; j++){
+    Btree *pBt = db->aDb[j].pBt;
+    if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
+  }
+  return 0;
+}
 
+/*
+** Close an existing SQLite database
+*/
+static int sqlite3Close(sqlite3 *db, int forceZombie){
   if( !db ){
+    /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
+    ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
     return SQLITE_OK;
   }
   if( !sqlite3SafetyCheckSickOrOk(db) ){
     return SQLITE_MISUSE_BKPT;
   }
   sqlite3_mutex_enter(db->mutex);
+  if( db->mTrace & SQLITE_TRACE_CLOSE ){
+    db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
+  }
 
-  /* Force xDestroy calls on all virtual tables */
-  sqlite3ResetInternalSchema(db, -1);
+  /* Force xDisconnect calls on all virtual tables */
+  disconnectAllVtab(db);
 
-  /* If a transaction is open, the ResetInternalSchema() call above
+  /* If a transaction is open, the disconnectAllVtab() call above
   ** will not have called the xDisconnect() method on any virtual
   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
   ** call will do so. We need to do this before the check for active
@@ -111249,28 +137544,80 @@ SQLITE_API int sqlite3_close(sqlite3 *db){
   */
   sqlite3VtabRollback(db);
 
-  /* If there are any outstanding VMs, return SQLITE_BUSY. */
-  if( db->pVdbe ){
-    sqlite3Error(db, SQLITE_BUSY, 
-        "unable to close due to unfinalised statements");
+  /* Legacy behavior (sqlite3_close() behavior) is to return
+  ** SQLITE_BUSY if the connection can not be closed immediately.
+  */
+  if( !forceZombie && connectionIsBusy(db) ){
+    sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
+       "statements or unfinished backups");
     sqlite3_mutex_leave(db->mutex);
     return SQLITE_BUSY;
   }
-  assert( sqlite3SafetyCheckSickOrOk(db) );
 
-  for(j=0; j<db->nDb; j++){
-    Btree *pBt = db->aDb[j].pBt;
-    if( pBt && sqlite3BtreeIsInBackup(pBt) ){
-      sqlite3Error(db, SQLITE_BUSY, 
-          "unable to close due to unfinished backup operation");
-      sqlite3_mutex_leave(db->mutex);
-      return SQLITE_BUSY;
-    }
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Closing the handle. Fourth parameter is passed the value 2. */
+    sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
   }
+#endif
+
+  /* Convert the connection into a zombie and then close it.
+  */
+  db->magic = SQLITE_MAGIC_ZOMBIE;
+  sqlite3LeaveMutexAndCloseZombie(db);
+  return SQLITE_OK;
+}
+
+/*
+** Two variations on the public interface for closing a database
+** connection. The sqlite3_close() version returns SQLITE_BUSY and
+** leaves the connection option if there are unfinalized prepared
+** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
+** version forces the connection to become a zombie if there are
+** unclosed resources, and arranges for deallocation when the last
+** prepare statement or sqlite3_backup closes.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
+SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
+
+
+/*
+** Close the mutex on database connection db.
+**
+** Furthermore, if database connection db is a zombie (meaning that there
+** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
+** every sqlite3_stmt has now been finalized and every sqlite3_backup has
+** finished, then free all resources.
+*/
+SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
+  HashElem *i;                    /* Hash table iterator */
+  int j;
+
+  /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
+  ** or if the connection has not yet been closed by sqlite3_close_v2(),
+  ** then just leave the mutex and return.
+  */
+  if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
+    sqlite3_mutex_leave(db->mutex);
+    return;
+  }
+
+  /* If we reach this point, it means that the database connection has
+  ** closed all sqlite3_stmt and sqlite3_backup objects and has been
+  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
+  ** go ahead and free all resources.
+  */
+
+  /* If a transaction is open, roll it back. This also ensures that if
+  ** any database schemas have been modified by an uncommitted transaction
+  ** they are reset. And that the required b-tree mutex is held to make
+  ** the pager rollback and schema reset an atomic operation. */
+  sqlite3RollbackAll(db, SQLITE_OK);
 
   /* Free any outstanding Savepoint structures. */
   sqlite3CloseSavepoints(db);
 
+  /* Close all database connections */
   for(j=0; j<db->nDb; j++){
     struct Db *pDb = &db->aDb[j];
     if( pDb->pBt ){
@@ -111281,27 +137628,33 @@ SQLITE_API int sqlite3_close(sqlite3 *db){
       }
     }
   }
-  sqlite3ResetInternalSchema(db, -1);
+  /* Clear the TEMP schema separately and last */
+  if( db->aDb[1].pSchema ){
+    sqlite3SchemaClear(db->aDb[1].pSchema);
+  }
+  sqlite3VtabUnlockList(db);
+
+  /* Free up the array of auxiliary databases */
+  sqlite3CollapseDatabaseArray(db);
+  assert( db->nDb<=2 );
+  assert( db->aDb==db->aDbStatic );
 
   /* Tell the code in notify.c that the connection no longer holds any
   ** locks and does not require any further unlock-notify callbacks.
   */
   sqlite3ConnectionClosed(db);
 
-  assert( db->nDb<=2 );
-  assert( db->aDb==db->aDbStatic );
-  for(j=0; j<ArraySize(db->aFunc.a); j++){
-    FuncDef *pNext, *pHash, *p;
-    for(p=db->aFunc.a[j]; p; p=pHash){
-      pHash = p->pHash;
-      while( p ){
-        functionDestroy(db, p);
-        pNext = p->pNext;
-        sqlite3DbFree(db, p);
-        p = pNext;
-      }
-    }
+  for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
+    FuncDef *pNext, *p;
+    p = sqliteHashData(i);
+    do{
+      functionDestroy(db, p);
+      pNext = p->pNext;
+      sqlite3DbFree(db, p);
+      p = pNext;
+    }while( p );
   }
+  sqlite3HashClear(&db->aFunc);
   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
     CollSeq *pColl = (CollSeq *)sqliteHashData(i);
     /* Invoke any destructors registered for collation sequence user data. */
@@ -111319,16 +137672,19 @@ SQLITE_API int sqlite3_close(sqlite3 *db){
     if( pMod->xDestroy ){
       pMod->xDestroy(pMod->pAux);
     }
+    sqlite3VtabEponymousTableClear(db, pMod);
     sqlite3DbFree(db, pMod);
   }
   sqlite3HashClear(&db->aModule);
 #endif
 
-  sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
-  if( db->pErr ){
-    sqlite3ValueFree(db->pErr);
-  }
+  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
+  sqlite3ValueFree(db->pErr);
   sqlite3CloseExtensions(db);
+#if SQLITE_USER_AUTHENTICATION
+  sqlite3_free(db->auth.zAuthUser);
+  sqlite3_free(db->auth.zAuthPW);
+#endif
 
   db->magic = SQLITE_MAGIC_ERROR;
 
@@ -111347,36 +137703,53 @@ SQLITE_API int sqlite3_close(sqlite3 *db){
     sqlite3_free(db->lookaside.pStart);
   }
   sqlite3_free(db);
-  return SQLITE_OK;
 }
 
 /*
-** Rollback all database files.
+** Rollback all database files.  If tripCode is not SQLITE_OK, then
+** any write cursors are invalidated ("tripped" - as in "tripping a circuit
+** breaker") and made to return tripCode if there are any further
+** attempts to use that cursor.  Read cursors remain open and valid
+** but are "saved" in case the table pages are moved around.
 */
-SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db){
+SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){
   int i;
   int inTrans = 0;
+  int schemaChange;
   assert( sqlite3_mutex_held(db->mutex) );
   sqlite3BeginBenignMalloc();
+
+  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
+  ** This is important in case the transaction being rolled back has
+  ** modified the database schema. If the b-tree mutexes are not taken
+  ** here, then another shared-cache connection might sneak in between
+  ** the database rollback and schema reset, which can cause false
+  ** corruption reports in some cases.  */
+  sqlite3BtreeEnterAll(db);
+  schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
+
   for(i=0; i<db->nDb; i++){
-    if( db->aDb[i].pBt ){
-      if( sqlite3BtreeIsInTrans(db->aDb[i].pBt) ){
+    Btree *p = db->aDb[i].pBt;
+    if( p ){
+      if( sqlite3BtreeIsInTrans(p) ){
         inTrans = 1;
       }
-      sqlite3BtreeRollback(db->aDb[i].pBt);
-      db->aDb[i].inTrans = 0;
+      sqlite3BtreeRollback(p, tripCode, !schemaChange);
     }
   }
   sqlite3VtabRollback(db);
   sqlite3EndBenignMalloc();
 
-  if( db->flags&SQLITE_InternChanges ){
+  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
     sqlite3ExpirePreparedStatements(db);
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
   }
+  sqlite3BtreeLeaveAll(db);
 
   /* Any deferred constraint violations have now been resolved. */
   db->nDeferredCons = 0;
+  db->nDeferredImmCons = 0;
+  db->flags &= ~SQLITE_DeferFKs;
 
   /* If one has been configured, invoke the rollback-hook callback */
   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
@@ -111385,6 +137758,115 @@ SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db){
 }
 
 /*
+** Return a static string containing the name corresponding to the error code
+** specified in the argument.
+*/
+#if defined(SQLITE_NEED_ERR_NAME)
+SQLITE_PRIVATE const char *sqlite3ErrName(int rc){
+  const char *zName = 0;
+  int i, origRc = rc;
+  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
+    switch( rc ){
+      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
+      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
+      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
+      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
+      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
+      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
+      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
+      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
+      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
+      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
+      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
+      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
+      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
+      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
+      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
+      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
+      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
+      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
+      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
+      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
+      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
+      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
+      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
+      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
+      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
+      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
+      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
+      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
+      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
+      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
+      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
+      case SQLITE_IOERR_CHECKRESERVEDLOCK:
+                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
+      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
+      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
+      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
+      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
+      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
+      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
+      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
+      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
+      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
+      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
+      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
+      case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
+      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
+      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
+      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
+      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
+      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
+      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
+      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
+      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
+      case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
+      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
+      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
+      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
+      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
+      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
+      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
+      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
+      case SQLITE_CONSTRAINT_FOREIGNKEY:
+                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
+      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
+      case SQLITE_CONSTRAINT_PRIMARYKEY:
+                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
+      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
+      case SQLITE_CONSTRAINT_COMMITHOOK:
+                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
+      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
+      case SQLITE_CONSTRAINT_FUNCTION:
+                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
+      case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
+      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
+      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
+      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
+      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
+      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
+      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
+      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
+      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
+      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
+      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
+      case SQLITE_NOTICE_RECOVER_ROLLBACK:
+                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
+      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
+      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
+      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
+    }
+  }
+  if( zName==0 ){
+    static char zBuf[50];
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
+    zName = zBuf;
+  }
+  return zName;
+}
+#endif
+
+/*
 ** Return a static string that describes the kind of error specified in the
 ** argument.
 */
@@ -111418,12 +137900,21 @@ SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){
     /* SQLITE_RANGE       */ "bind or column index out of range",
     /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
   };
-  rc &= 0xff;
-  if( ALWAYS(rc>=0) && rc<(int)(sizeof(aMsg)/sizeof(aMsg[0])) && aMsg[rc]!=0 ){
-    return aMsg[rc];
-  }else{
-    return "unknown error";
+  const char *zErr = "unknown error";
+  switch( rc ){
+    case SQLITE_ABORT_ROLLBACK: {
+      zErr = "abort due to ROLLBACK";
+      break;
+    }
+    default: {
+      rc &= 0xff;
+      if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
+        zErr = aMsg[rc];
+      }
+      break;
+    }
   }
+  return zErr;
 }
 
 /*
@@ -111436,7 +137927,7 @@ static int sqliteDefaultBusyCallback(
  void *ptr,               /* Database connection */
  int count                /* Number of times table has been busy */
 ){
-#if SQLITE_OS_WIN || (defined(HAVE_USLEEP) && HAVE_USLEEP)
+#if SQLITE_OS_WIN || HAVE_USLEEP
   static const u8 delays[] =
      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
   static const u8 totals[] =
@@ -111494,15 +137985,19 @@ SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler *p){
 ** This routine sets the busy callback for an Sqlite database to the
 ** given callback function with the given argument.
 */
-SQLITE_API int sqlite3_busy_handler(
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(
   sqlite3 *db,
   int (*xBusy)(void*,int),
   void *pArg
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   db->busyHandler.xFunc = xBusy;
   db->busyHandler.pArg = pArg;
   db->busyHandler.nBusy = 0;
+  db->busyTimeout = 0;
   sqlite3_mutex_leave(db->mutex);
   return SQLITE_OK;
 }
@@ -111513,16 +138008,22 @@ SQLITE_API int sqlite3_busy_handler(
 ** given callback function with the given argument. The progress callback will
 ** be invoked every nOps opcodes.
 */
-SQLITE_API void sqlite3_progress_handler(
+SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(
   sqlite3 *db, 
   int nOps,
   int (*xProgress)(void*), 
   void *pArg
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   if( nOps>0 ){
     db->xProgress = xProgress;
-    db->nProgressOps = nOps;
+    db->nProgressOps = (unsigned)nOps;
     db->pProgressArg = pArg;
   }else{
     db->xProgress = 0;
@@ -111538,10 +138039,13 @@ SQLITE_API void sqlite3_progress_handler(
 ** This routine installs a default busy handler that waits for the
 ** specified number of milliseconds before returning 0.
 */
-SQLITE_API int sqlite3_busy_timeout(sqlite3 *db, int ms){
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3 *db, int ms){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   if( ms>0 ){
-    db->busyTimeout = ms;
     sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
+    db->busyTimeout = ms;
   }else{
     sqlite3_busy_handler(db, 0, 0);
   }
@@ -111551,7 +138055,13 @@ SQLITE_API int sqlite3_busy_timeout(sqlite3 *db, int ms){
 /*
 ** Cause any pending operation to stop at its earliest opportunity.
 */
-SQLITE_API void sqlite3_interrupt(sqlite3 *db){
+SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
   db->u1.isInterrupted = 1;
 }
 
@@ -111568,23 +138078,28 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
   int nArg,
   int enc,
   void *pUserData,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
   void (*xFinal)(sqlite3_context*),
   FuncDestructor *pDestructor
 ){
   FuncDef *p;
   int nName;
+  int extraFlags;
 
   assert( sqlite3_mutex_held(db->mutex) );
   if( zFunctionName==0 ||
-      (xFunc && (xFinal || xStep)) || 
-      (!xFunc && (xFinal && !xStep)) ||
-      (!xFunc && (!xFinal && xStep)) ||
+      (xSFunc && (xFinal || xStep)) || 
+      (!xSFunc && (xFinal && !xStep)) ||
+      (!xSFunc && (!xFinal && xStep)) ||
       (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
     return SQLITE_MISUSE_BKPT;
   }
+
+  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
+  extraFlags = enc &  SQLITE_DETERMINISTIC;
+  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
   
 #ifndef SQLITE_OMIT_UTF16
   /* If SQLITE_UTF16 is specified as the encoding type, transform this
@@ -111598,11 +138113,11 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
     enc = SQLITE_UTF16NATIVE;
   }else if( enc==SQLITE_ANY ){
     int rc;
-    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8,
-         pUserData, xFunc, xStep, xFinal, pDestructor);
+    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
+         pUserData, xSFunc, xStep, xFinal, pDestructor);
     if( rc==SQLITE_OK ){
-      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE,
-          pUserData, xFunc, xStep, xFinal, pDestructor);
+      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
+          pUserData, xSFunc, xStep, xFinal, pDestructor);
     }
     if( rc!=SQLITE_OK ){
       return rc;
@@ -111618,10 +138133,10 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
   ** is being overridden/deleted but there are no active VMs, allow the
   ** operation to continue but invalidate all precompiled statements.
   */
-  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
-  if( p && p->iPrefEnc==enc && p->nArg==nArg ){
-    if( db->activeVdbeCnt ){
-      sqlite3Error(db, SQLITE_BUSY, 
+  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
+  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
         "unable to delete/modify user-function due to active statements");
       assert( !db->mallocFailed );
       return SQLITE_BUSY;
@@ -111630,10 +138145,10 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
     }
   }
 
-  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 1);
+  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
   assert(p || db->mallocFailed);
   if( !p ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
 
   /* If an older version of the function with a configured destructor is
@@ -111643,10 +138158,10 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
   if( pDestructor ){
     pDestructor->nRef++;
   }
-  p->pDestructor = pDestructor;
-  p->flags = 0;
-  p->xFunc = xFunc;
-  p->xStep = xStep;
+  p->u.pDestructor = pDestructor;
+  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
+  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
+  p->xSFunc = xSFunc ? xSFunc : xStep;
   p->xFinalize = xFinal;
   p->pUserData = pUserData;
   p->nArg = (u16)nArg;
@@ -111656,33 +138171,39 @@ SQLITE_PRIVATE int sqlite3CreateFunc(
 /*
 ** Create new user functions.
 */
-SQLITE_API int sqlite3_create_function(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
   sqlite3 *db,
   const char *zFunc,
   int nArg,
   int enc,
   void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
   void (*xFinal)(sqlite3_context*)
 ){
-  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
+  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xSFunc, xStep,
                                     xFinal, 0);
 }
 
-SQLITE_API int sqlite3_create_function_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
   sqlite3 *db,
   const char *zFunc,
   int nArg,
   int enc,
   void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
   void (*xStep)(sqlite3_context*,int,sqlite3_value **),
   void (*xFinal)(sqlite3_context*),
   void (*xDestroy)(void *)
 ){
   int rc = SQLITE_ERROR;
   FuncDestructor *pArg = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   if( xDestroy ){
     pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
@@ -111693,7 +138214,7 @@ SQLITE_API int sqlite3_create_function_v2(
     pArg->xDestroy = xDestroy;
     pArg->pUserData = p;
   }
-  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
+  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xSFunc, xStep, xFinal, pArg);
   if( pArg && pArg->nRef==0 ){
     assert( rc!=SQLITE_OK );
     xDestroy(p);
@@ -111707,22 +138228,26 @@ SQLITE_API int sqlite3_create_function_v2(
 }
 
 #ifndef SQLITE_OMIT_UTF16
-SQLITE_API int sqlite3_create_function16(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
   sqlite3 *db,
   const void *zFunctionName,
   int nArg,
   int eTextRep,
   void *p,
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
+  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
   void (*xFinal)(sqlite3_context*)
 ){
   int rc;
   char *zFunc8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   assert( !db->mallocFailed );
   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
-  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
+  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0);
   sqlite3DbFree(db, zFunc8);
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
@@ -111743,15 +138268,20 @@ SQLITE_API int sqlite3_create_function16(
 ** A global function must exist in order for name resolution to work
 ** properly.
 */
-SQLITE_API int sqlite3_overload_function(
+SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(
   sqlite3 *db,
   const char *zName,
   int nArg
 ){
-  int nName = sqlite3Strlen30(zName);
   int rc = SQLITE_OK;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
-  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
+  if( sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)==0 ){
     rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
                            0, sqlite3InvalidFunction, 0, 0, 0);
   }
@@ -111769,15 +138299,48 @@ SQLITE_API int sqlite3_overload_function(
 ** trace is a pointer to a function that is invoked at the start of each
 ** SQL statement.
 */
-SQLITE_API void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
+#ifndef SQLITE_OMIT_DEPRECATED
+SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
   void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pOld = db->pTraceArg;
-  db->xTrace = xTrace;
+  db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
+  db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
   db->pTraceArg = pArg;
   sqlite3_mutex_leave(db->mutex);
   return pOld;
 }
+#endif /* SQLITE_OMIT_DEPRECATED */
+
+/* Register a trace callback using the version-2 interface.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_trace_v2(
+  sqlite3 *db,                               /* Trace this connection */
+  unsigned mTrace,                           /* Mask of events to be traced */
+  int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
+  void *pArg                                 /* Context */
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->mTrace = mTrace;
+  db->xTrace = xTrace;
+  db->pTraceArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_DEPRECATED
 /*
 ** Register a profile function.  The pArg from the previously registered 
 ** profile function is returned.  
@@ -111786,12 +138349,19 @@ SQLITE_API void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), v
 ** profile is a pointer to a function that is invoked at the conclusion of
 ** each SQL statement that is run.
 */
-SQLITE_API void *sqlite3_profile(
+SQLITE_API void *SQLITE_STDCALL sqlite3_profile(
   sqlite3 *db,
   void (*xProfile)(void*,const char*,sqlite_uint64),
   void *pArg
 ){
   void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pOld = db->pProfileArg;
   db->xProfile = xProfile;
@@ -111799,20 +138369,27 @@ SQLITE_API void *sqlite3_profile(
   sqlite3_mutex_leave(db->mutex);
   return pOld;
 }
+#endif /* SQLITE_OMIT_DEPRECATED */
 #endif /* SQLITE_OMIT_TRACE */
 
-/*** EXPERIMENTAL ***
-**
-** Register a function to be invoked when a transaction comments.
+/*
+** Register a function to be invoked when a transaction commits.
 ** If the invoked function returns non-zero, then the commit becomes a
 ** rollback.
 */
-SQLITE_API void *sqlite3_commit_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(
   sqlite3 *db,              /* Attach the hook to this database */
   int (*xCallback)(void*),  /* Function to invoke on each commit */
   void *pArg                /* Argument to the function */
 ){
   void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pOld = db->pCommitArg;
   db->xCommitCallback = xCallback;
@@ -111825,12 +138402,19 @@ SQLITE_API void *sqlite3_commit_hook(
 ** Register a callback to be invoked each time a row is updated,
 ** inserted or deleted using this database connection.
 */
-SQLITE_API void *sqlite3_update_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
   sqlite3 *db,              /* Attach the hook to this database */
   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
   void *pArg                /* Argument to the function */
 ){
   void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pRet = db->pUpdateArg;
   db->xUpdateCallback = xCallback;
@@ -111843,12 +138427,19 @@ SQLITE_API void *sqlite3_update_hook(
 ** Register a callback to be invoked each time a transaction is rolled
 ** back by this database connection.
 */
-SQLITE_API void *sqlite3_rollback_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(
   sqlite3 *db,              /* Attach the hook to this database */
   void (*xCallback)(void*), /* Callback function */
   void *pArg                /* Argument to the function */
 ){
   void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pRet = db->pRollbackArg;
   db->xRollbackCallback = xCallback;
@@ -111857,6 +138448,27 @@ SQLITE_API void *sqlite3_rollback_hook(
   return pRet;
 }
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_preupdate_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void(*xCallback)(         /* Callback function */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
+  void *pArg                /* First callback argument */
+){
+  void *pRet;
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pPreUpdateArg;
+  db->xPreUpdateCallback = xCallback;
+  db->pPreUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 #ifndef SQLITE_OMIT_WAL
 /*
 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
@@ -111890,11 +138502,14 @@ SQLITE_PRIVATE int sqlite3WalDefaultHook(
 ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
 ** configured by this function.
 */
-SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
 #ifdef SQLITE_OMIT_WAL
   UNUSED_PARAMETER(db);
   UNUSED_PARAMETER(nFrame);
 #else
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   if( nFrame>0 ){
     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
   }else{
@@ -111908,13 +138523,19 @@ SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
 ** Register a callback to be invoked each time a transaction is written
 ** into the write-ahead-log by this database connection.
 */
-SQLITE_API void *sqlite3_wal_hook(
+SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
   sqlite3 *db,                    /* Attach the hook to this db handle */
   int(*xCallback)(void *, sqlite3*, const char*, int),
   void *pArg                      /* First argument passed to xCallback() */
 ){
 #ifndef SQLITE_OMIT_WAL
   void *pRet;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   sqlite3_mutex_enter(db->mutex);
   pRet = db->pWalArg;
   db->xWalCallback = xCallback;
@@ -111929,7 +138550,7 @@ SQLITE_API void *sqlite3_wal_hook(
 /*
 ** Checkpoint database zDb.
 */
-SQLITE_API int sqlite3_wal_checkpoint_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
   sqlite3 *db,                    /* Database handle */
   const char *zDb,                /* Name of attached database (or NULL) */
   int eMode,                      /* SQLITE_CHECKPOINT_* value */
@@ -111942,14 +138563,21 @@ SQLITE_API int sqlite3_wal_checkpoint_v2(
   int rc;                         /* Return code */
   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+
   /* Initialize the output variables to -1 in case an error occurs. */
   if( pnLog ) *pnLog = -1;
   if( pnCkpt ) *pnCkpt = -1;
 
-  assert( SQLITE_CHECKPOINT_FULL>SQLITE_CHECKPOINT_PASSIVE );
-  assert( SQLITE_CHECKPOINT_FULL<SQLITE_CHECKPOINT_RESTART );
-  assert( SQLITE_CHECKPOINT_PASSIVE+2==SQLITE_CHECKPOINT_RESTART );
-  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_RESTART ){
+  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
+  assert( SQLITE_CHECKPOINT_FULL==1 );
+  assert( SQLITE_CHECKPOINT_RESTART==2 );
+  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
+  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
+    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
+    ** mode: */
     return SQLITE_MISUSE;
   }
 
@@ -111959,10 +138587,11 @@ SQLITE_API int sqlite3_wal_checkpoint_v2(
   }
   if( iDb<0 ){
     rc = SQLITE_ERROR;
-    sqlite3Error(db, SQLITE_ERROR, "unknown database: %s", zDb);
+    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
   }else{
+    db->busyHandler.nBusy = 0;
     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
-    sqlite3Error(db, rc, 0);
+    sqlite3Error(db, rc);
   }
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
@@ -111976,8 +138605,10 @@ SQLITE_API int sqlite3_wal_checkpoint_v2(
 ** to contains a zero-length string, all attached databases are 
 ** checkpointed.
 */
-SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
-  return sqlite3_wal_checkpoint_v2(db, zDb, SQLITE_CHECKPOINT_PASSIVE, 0, 0);
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
+  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
+  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
+  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
 }
 
 #ifndef SQLITE_OMIT_WAL
@@ -112052,9 +138683,11 @@ SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){
   return ( db->temp_store!=1 );
 #endif
 #if SQLITE_TEMP_STORE==3
+  UNUSED_PARAMETER(db);
   return 1;
 #endif
 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
+  UNUSED_PARAMETER(db);
   return 0;
 #endif
 }
@@ -112063,18 +138696,19 @@ SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){
 ** Return UTF-8 encoded English language explanation of the most recent
 ** error.
 */
-SQLITE_API const char *sqlite3_errmsg(sqlite3 *db){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3 *db){
   const char *z;
   if( !db ){
-    return sqlite3ErrStr(SQLITE_NOMEM);
+    return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
   }
   if( !sqlite3SafetyCheckSickOrOk(db) ){
     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
   }
   sqlite3_mutex_enter(db->mutex);
   if( db->mallocFailed ){
-    z = sqlite3ErrStr(SQLITE_NOMEM);
+    z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
   }else{
+    testcase( db->pErr==0 );
     z = (char*)sqlite3_value_text(db->pErr);
     assert( !db->mallocFailed );
     if( z==0 ){
@@ -112090,7 +138724,7 @@ SQLITE_API const char *sqlite3_errmsg(sqlite3 *db){
 ** Return UTF-16 encoded English language explanation of the most recent
 ** error.
 */
-SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
+SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3 *db){
   static const u16 outOfMem[] = {
     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
   };
@@ -112116,8 +138750,7 @@ SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
   }else{
     z = sqlite3_value_text16(db->pErr);
     if( z==0 ){
-      sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
-           SQLITE_UTF8, SQLITE_STATIC);
+      sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
       z = sqlite3_value_text16(db->pErr);
     }
     /* A malloc() may have failed within the call to sqlite3_value_text16()
@@ -112125,7 +138758,7 @@ SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
     ** be cleared before returning. Do this directly, instead of via
     ** sqlite3ApiExit(), to avoid setting the database handle error message.
     */
-    db->mallocFailed = 0;
+    sqlite3OomClear(db);
   }
   sqlite3_mutex_leave(db->mutex);
   return z;
@@ -112136,24 +138769,36 @@ SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){
 ** Return the most recent error code generated by an SQLite routine. If NULL is
 ** passed to this function, we assume a malloc() failed during sqlite3_open().
 */
-SQLITE_API int sqlite3_errcode(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db){
   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
     return SQLITE_MISUSE_BKPT;
   }
   if( !db || db->mallocFailed ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   return db->errCode & db->errMask;
 }
-SQLITE_API int sqlite3_extended_errcode(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db){
   if( db && !sqlite3SafetyCheckSickOrOk(db) ){
     return SQLITE_MISUSE_BKPT;
   }
   if( !db || db->mallocFailed ){
-    return SQLITE_NOMEM;
+    return SQLITE_NOMEM_BKPT;
   }
   return db->errCode;
 }
+SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3 *db){
+  return db ? db->iSysErrno : 0;
+}  
+
+/*
+** Return a string that describes the kind of error specified in the
+** argument.  For now, this simply calls the internal sqlite3ErrStr()
+** function.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int rc){
+  return sqlite3ErrStr(rc);
+}
 
 /*
 ** Create a new collating function for database "db".  The name is zName
@@ -112163,14 +138808,12 @@ static int createCollation(
   sqlite3* db,
   const char *zName, 
   u8 enc,
-  u8 collType,
   void* pCtx,
   int(*xCompare)(void*,int,const void*,int,const void*),
   void(*xDel)(void*)
 ){
   CollSeq *pColl;
   int enc2;
-  int nName = sqlite3Strlen30(zName);
   
   assert( sqlite3_mutex_held(db->mutex) );
 
@@ -112194,8 +138837,8 @@ static int createCollation(
   */
   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
   if( pColl && pColl->xCmp ){
-    if( db->activeVdbeCnt ){
-      sqlite3Error(db, SQLITE_BUSY, 
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
         "unable to delete/modify collation sequence due to active statements");
       return SQLITE_BUSY;
     }
@@ -112208,7 +138851,7 @@ static int createCollation(
     ** to be called.
     */ 
     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
-      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName, nName);
+      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
       int j;
       for(j=0; j<3; j++){
         CollSeq *p = &aColl[j];
@@ -112223,13 +138866,12 @@ static int createCollation(
   }
 
   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
-  if( pColl==0 ) return SQLITE_NOMEM;
+  if( pColl==0 ) return SQLITE_NOMEM_BKPT;
   pColl->xCmp = xCompare;
   pColl->pUser = pCtx;
   pColl->xDel = xDel;
   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
-  pColl->type = collType;
-  sqlite3Error(db, SQLITE_OK, 0);
+  sqlite3Error(db, SQLITE_OK);
   return SQLITE_OK;
 }
 
@@ -112249,8 +138891,9 @@ static const int aHardLimit[] = {
   SQLITE_MAX_FUNCTION_ARG,
   SQLITE_MAX_ATTACHED,
   SQLITE_MAX_LIKE_PATTERN_LENGTH,
-  SQLITE_MAX_VARIABLE_NUMBER,
+  SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
   SQLITE_MAX_TRIGGER_DEPTH,
+  SQLITE_MAX_WORKER_THREADS,
 };
 
 /*
@@ -112271,11 +138914,11 @@ static const int aHardLimit[] = {
 #if SQLITE_MAX_VDBE_OP<40
 # error SQLITE_MAX_VDBE_OP must be at least 40
 #endif
-#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
-# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
+#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
+# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
 #endif
-#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>62
-# error SQLITE_MAX_ATTACHED must be between 0 and 62
+#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
+# error SQLITE_MAX_ATTACHED must be between 0 and 125
 #endif
 #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
 # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
@@ -112286,6 +138929,9 @@ static const int aHardLimit[] = {
 #if SQLITE_MAX_TRIGGER_DEPTH<1
 # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
 #endif
+#if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
+# error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
+#endif
 
 
 /*
@@ -112298,9 +138944,15 @@ static const int aHardLimit[] = {
 ** It merely prevents new constructs that exceed the limit
 ** from forming.
 */
-SQLITE_API int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
+SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
   int oldLimit;
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
 
   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
   ** there is a hard upper bound set at compile-time by a C preprocessor
@@ -112319,7 +138971,8 @@ SQLITE_API int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );
   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
-  assert( SQLITE_LIMIT_TRIGGER_DEPTH==(SQLITE_N_LIMIT-1) );
+  assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
+  assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
 
 
   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
@@ -112376,37 +139029,50 @@ SQLITE_PRIVATE int sqlite3ParseUri(
 
   assert( *pzErrMsg==0 );
 
-  if( ((flags & SQLITE_OPEN_URI) || sqlite3GlobalConfig.bOpenUri) 
-   && nUri>=5 && memcmp(zUri, "file:", 5)==0 
+  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
+            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
+   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
   ){
     char *zOpt;
     int eState;                   /* Parser state when parsing URI */
     int iIn;                      /* Input character index */
     int iOut = 0;                 /* Output character index */
-    int nByte = nUri+2;           /* Bytes of space to allocate */
+    u64 nByte = nUri+2;           /* Bytes of space to allocate */
 
     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
     ** method that there may be extra parameters following the file-name.  */
     flags |= SQLITE_OPEN_URI;
 
     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
-    zFile = sqlite3_malloc(nByte);
-    if( !zFile ) return SQLITE_NOMEM;
+    zFile = sqlite3_malloc64(nByte);
+    if( !zFile ) return SQLITE_NOMEM_BKPT;
 
+    iIn = 5;
+#ifdef SQLITE_ALLOW_URI_AUTHORITY
+    if( strncmp(zUri+5, "///", 3)==0 ){
+      iIn = 7;
+      /* The following condition causes URIs with five leading / characters
+      ** like file://///host/path to be converted into UNCs like //host/path.
+      ** The correct URI for that UNC has only two or four leading / characters
+      ** file://host/path or file:////host/path.  But 5 leading slashes is a 
+      ** common error, we are told, so we handle it as a special case. */
+      if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
+    }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
+      iIn = 16;
+    }
+#else
     /* Discard the scheme and authority segments of the URI. */
     if( zUri[5]=='/' && zUri[6]=='/' ){
       iIn = 7;
       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
-
       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
             iIn-7, &zUri[7]);
         rc = SQLITE_ERROR;
         goto parse_uri_out;
       }
-    }else{
-      iIn = 5;
     }
+#endif
 
     /* Copy the filename and any query parameters into the zFile buffer. 
     ** Decode %HH escape codes along the way. 
@@ -112504,10 +139170,12 @@ SQLITE_PRIVATE int sqlite3ParseUri(
             { "ro",  SQLITE_OPEN_READONLY },
             { "rw",  SQLITE_OPEN_READWRITE }, 
             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
+            { "memory", SQLITE_OPEN_MEMORY },
             { 0, 0 }
           };
 
-          mask = SQLITE_OPEN_READONLY|SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
+          mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
+                   | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
           aMode = aOpenMode;
           limit = mask & flags;
           zModeType = "access";
@@ -112528,7 +139196,7 @@ SQLITE_PRIVATE int sqlite3ParseUri(
             rc = SQLITE_ERROR;
             goto parse_uri_out;
           }
-          if( mode>limit ){
+          if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
                                         zModeType, zVal);
             rc = SQLITE_PERM;
@@ -112542,11 +139210,12 @@ SQLITE_PRIVATE int sqlite3ParseUri(
     }
 
   }else{
-    zFile = sqlite3_malloc(nUri+2);
-    if( !zFile ) return SQLITE_NOMEM;
+    zFile = sqlite3_malloc64(nUri+2);
+    if( !zFile ) return SQLITE_NOMEM_BKPT;
     memcpy(zFile, zUri, nUri);
     zFile[nUri] = '\0';
     zFile[nUri+1] = '\0';
+    flags &= ~SQLITE_OPEN_URI;
   }
 
   *ppVfs = sqlite3_vfs_find(zVfs);
@@ -112582,6 +139251,9 @@ static int openDatabase(
   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
 
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   *ppDb = 0;
 #ifndef SQLITE_OMIT_AUTOINIT
   rc = sqlite3_initialize();
@@ -112604,7 +139276,9 @@ static int openDatabase(
   testcase( (1<<(flags&7))==0x02 ); /* READONLY */
   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
-  if( ((1<<(flags&7)) & 0x46)==0 ) return SQLITE_MISUSE_BKPT;
+  if( ((1<<(flags&7)) & 0x46)==0 ){
+    return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
+  }
 
   if( sqlite3GlobalConfig.bCoreMutex==0 ){
     isThreadsafe = 0;
@@ -112663,10 +139337,19 @@ static int openDatabase(
 
   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
+  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
   db->autoCommit = 1;
   db->nextAutovac = -1;
+  db->szMmap = sqlite3GlobalConfig.szMmap;
   db->nextPagesize = 0;
-  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
+  db->nMaxSorterMmap = 0x7FFFFFFF;
+  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
+#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
+                 | SQLITE_AutoIndex
+#endif
+#if SQLITE_DEFAULT_CKPTFULLFSYNC
+                 | SQLITE_CkptFullFSync
+#endif
 #if SQLITE_DEFAULT_FILE_FORMAT<4
                  | SQLITE_LegacyFileFmt
 #endif
@@ -112679,6 +139362,15 @@ static int openDatabase(
 #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
                  | SQLITE_ForeignKeys
 #endif
+#if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
+                 | SQLITE_ReverseOrder
+#endif
+#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
+                 | SQLITE_CellSizeCk
+#endif
+#if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
+                 | SQLITE_Fts3Tokenizer
+#endif
       ;
   sqlite3HashInit(&db->aCollSeq);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
@@ -112688,31 +139380,30 @@ static int openDatabase(
   /* Add the default collation sequence BINARY. BINARY works for both UTF-8
   ** and UTF-16, so add a version for each to avoid any unnecessary
   ** conversions. The only error that can occur here is a malloc() failure.
-  */
-  createCollation(db, "BINARY", SQLITE_UTF8, SQLITE_COLL_BINARY, 0,
-                  binCollFunc, 0);
-  createCollation(db, "BINARY", SQLITE_UTF16BE, SQLITE_COLL_BINARY, 0,
-                  binCollFunc, 0);
-  createCollation(db, "BINARY", SQLITE_UTF16LE, SQLITE_COLL_BINARY, 0,
-                  binCollFunc, 0);
-  createCollation(db, "RTRIM", SQLITE_UTF8, SQLITE_COLL_USER, (void*)1,
-                  binCollFunc, 0);
+  **
+  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
+  ** functions:
+  */
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
+  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
+  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
   if( db->mallocFailed ){
     goto opendb_out;
   }
-  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0);
+  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
+  ** strings is BINARY. 
+  */
+  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
   assert( db->pDfltColl!=0 );
 
-  /* Also add a UTF-8 case-insensitive collation sequence. */
-  createCollation(db, "NOCASE", SQLITE_UTF8, SQLITE_COLL_NOCASE, 0,
-                  nocaseCollatingFunc, 0);
-
   /* Parse the filename/URI argument. */
   db->openFlags = flags;
   rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
   if( rc!=SQLITE_OK ){
-    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
-    sqlite3Error(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
+    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
+    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
     sqlite3_free(zErrMsg);
     goto opendb_out;
   }
@@ -112722,22 +139413,24 @@ static int openDatabase(
                         flags | SQLITE_OPEN_MAIN_DB);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_IOERR_NOMEM ){
-      rc = SQLITE_NOMEM;
+      rc = SQLITE_NOMEM_BKPT;
     }
-    sqlite3Error(db, rc, 0);
+    sqlite3Error(db, rc);
     goto opendb_out;
   }
+  sqlite3BtreeEnter(db->aDb[0].pBt);
   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
+  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
+  sqlite3BtreeLeave(db->aDb[0].pBt);
   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
 
-
-  /* The default safety_level for the main database is 'full'; for the temp
-  ** database it is 'NONE'. This matches the pager layer defaults.  
+  /* The default safety_level for the main database is FULL; for the temp
+  ** database it is OFF. This matches the pager layer defaults.  
   */
   db->aDb[0].zName = "main";
-  db->aDb[0].safety_level = 3;
+  db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
   db->aDb[1].zName = "temp";
-  db->aDb[1].safety_level = 1;
+  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;
 
   db->magic = SQLITE_MAGIC_OPEN;
   if( db->mallocFailed ){
@@ -112748,16 +139441,19 @@ static int openDatabase(
   ** database schema yet. This is delayed until the first time the database
   ** is accessed.
   */
-  sqlite3Error(db, SQLITE_OK, 0);
-  sqlite3RegisterBuiltinFunctions(db);
+  sqlite3Error(db, SQLITE_OK);
+  sqlite3RegisterPerConnectionBuiltinFunctions(db);
 
   /* Load automatic extensions - extensions that have been registered
   ** using the sqlite3_automatic_extension() API.
   */
-  sqlite3AutoLoadExtensions(db);
   rc = sqlite3_errcode(db);
-  if( rc!=SQLITE_OK ){
-    goto opendb_out;
+  if( rc==SQLITE_OK ){
+    sqlite3AutoLoadExtensions(db);
+    rc = sqlite3_errcode(db);
+    if( rc!=SQLITE_OK ){
+      goto opendb_out;
+    }
   }
 
 #ifdef SQLITE_ENABLE_FTS1
@@ -112774,12 +139470,18 @@ static int openDatabase(
   }
 #endif
 
-#ifdef SQLITE_ENABLE_FTS3
+#ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
   if( !db->mallocFailed && rc==SQLITE_OK ){
     rc = sqlite3Fts3Init(db);
   }
 #endif
 
+#ifdef SQLITE_ENABLE_FTS5
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts5Init(db);
+  }
+#endif
+
 #ifdef SQLITE_ENABLE_ICU
   if( !db->mallocFailed && rc==SQLITE_OK ){
     rc = sqlite3IcuInit(db);
@@ -112792,7 +139494,17 @@ static int openDatabase(
   }
 #endif
 
-  sqlite3Error(db, rc, 0);
+#ifdef SQLITE_ENABLE_DBSTAT_VTAB
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3DbstatRegister(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_JSON1
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3Json1Init(db);
+  }
+#endif
 
   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
@@ -112804,6 +139516,8 @@ static int openDatabase(
                           SQLITE_DEFAULT_LOCKING_MODE);
 #endif
 
+  if( rc ) sqlite3Error(db, rc);
+
   /* Enable the lookaside-malloc subsystem */
   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
                         sqlite3GlobalConfig.nLookaside);
@@ -112811,9 +139525,9 @@ static int openDatabase(
   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
 
 opendb_out:
-  sqlite3_free(zOpen);
   if( db ){
-    assert( db->mutex!=0 || isThreadsafe==0 || sqlite3GlobalConfig.bFullMutex==0 );
+    assert( db->mutex!=0 || isThreadsafe==0
+           || sqlite3GlobalConfig.bFullMutex==0 );
     sqlite3_mutex_leave(db->mutex);
   }
   rc = sqlite3_errcode(db);
@@ -112825,20 +139539,43 @@ opendb_out:
     db->magic = SQLITE_MAGIC_SICK;
   }
   *ppDb = db;
-  return sqlite3ApiExit(0, rc);
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Opening a db handle. Fourth parameter is passed 0. */
+    void *pArg = sqlite3GlobalConfig.pSqllogArg;
+    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
+  }
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  if( rc==SQLITE_OK ){
+    const char *zHexKey = sqlite3_uri_parameter(zOpen, "hexkey");
+    if( zHexKey && zHexKey[0] ){
+      u8 iByte;
+      int i;
+      char zKey[40];
+      for(i=0, iByte=0; i<sizeof(zKey)*2 && sqlite3Isxdigit(zHexKey[i]); i++){
+        iByte = (iByte<<4) + sqlite3HexToInt(zHexKey[i]);
+        if( (i&1)!=0 ) zKey[i/2] = iByte;
+      }
+      sqlite3_key_v2(db, 0, zKey, i/2);
+    }
+  }
+#endif
+  sqlite3_free(zOpen);
+  return rc & 0xff;
 }
 
 /*
 ** Open a new database handle.
 */
-SQLITE_API int sqlite3_open(
+SQLITE_API int SQLITE_STDCALL sqlite3_open(
   const char *zFilename, 
   sqlite3 **ppDb 
 ){
   return openDatabase(zFilename, ppDb,
                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
 }
-SQLITE_API int sqlite3_open_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
   const char *filename,   /* Database filename (UTF-8) */
   sqlite3 **ppDb,         /* OUT: SQLite db handle */
   int flags,              /* Flags */
@@ -112851,7 +139588,7 @@ SQLITE_API int sqlite3_open_v2(
 /*
 ** Open a new database handle.
 */
-SQLITE_API int sqlite3_open16(
+SQLITE_API int SQLITE_STDCALL sqlite3_open16(
   const void *zFilename, 
   sqlite3 **ppDb
 ){
@@ -112859,13 +139596,15 @@ SQLITE_API int sqlite3_open16(
   sqlite3_value *pVal;
   int rc;
 
-  assert( zFilename );
-  assert( ppDb );
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   *ppDb = 0;
 #ifndef SQLITE_OMIT_AUTOINIT
   rc = sqlite3_initialize();
   if( rc ) return rc;
 #endif
+  if( zFilename==0 ) zFilename = "\000\000";
   pVal = sqlite3ValueNew(0);
   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
@@ -112874,40 +139613,34 @@ SQLITE_API int sqlite3_open16(
                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
     assert( *ppDb || rc==SQLITE_NOMEM );
     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
-      ENC(*ppDb) = SQLITE_UTF16NATIVE;
+      SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
     }
   }else{
-    rc = SQLITE_NOMEM;
+    rc = SQLITE_NOMEM_BKPT;
   }
   sqlite3ValueFree(pVal);
 
-  return sqlite3ApiExit(0, rc);
+  return rc & 0xff;
 }
 #endif /* SQLITE_OMIT_UTF16 */
 
 /*
 ** Register a new collation sequence with the database handle db.
 */
-SQLITE_API int sqlite3_create_collation(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
   sqlite3* db, 
   const char *zName, 
   int enc, 
   void* pCtx,
   int(*xCompare)(void*,int,const void*,int,const void*)
 ){
-  int rc;
-  sqlite3_mutex_enter(db->mutex);
-  assert( !db->mallocFailed );
-  rc = createCollation(db, zName, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, 0);
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
+  return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
 }
 
 /*
 ** Register a new collation sequence with the database handle db.
 */
-SQLITE_API int sqlite3_create_collation_v2(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
   sqlite3* db, 
   const char *zName, 
   int enc, 
@@ -112916,9 +139649,13 @@ SQLITE_API int sqlite3_create_collation_v2(
   void(*xDel)(void*)
 ){
   int rc;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   assert( !db->mallocFailed );
-  rc = createCollation(db, zName, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, xDel);
+  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
   return rc;
@@ -112928,7 +139665,7 @@ SQLITE_API int sqlite3_create_collation_v2(
 /*
 ** Register a new collation sequence with the database handle db.
 */
-SQLITE_API int sqlite3_create_collation16(
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
   sqlite3* db, 
   const void *zName,
   int enc, 
@@ -112937,11 +139674,15 @@ SQLITE_API int sqlite3_create_collation16(
 ){
   int rc = SQLITE_OK;
   char *zName8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   assert( !db->mallocFailed );
   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
   if( zName8 ){
-    rc = createCollation(db, zName8, (u8)enc, SQLITE_COLL_USER, pCtx, xCompare, 0);
+    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
     sqlite3DbFree(db, zName8);
   }
   rc = sqlite3ApiExit(db, rc);
@@ -112954,11 +139695,14 @@ SQLITE_API int sqlite3_create_collation16(
 ** Register a collation sequence factory callback with the database handle
 ** db. Replace any previously installed collation sequence factory.
 */
-SQLITE_API int sqlite3_collation_needed(
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
   sqlite3 *db, 
   void *pCollNeededArg, 
   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   db->xCollNeeded = xCollNeeded;
   db->xCollNeeded16 = 0;
@@ -112972,11 +139716,14 @@ SQLITE_API int sqlite3_collation_needed(
 ** Register a collation sequence factory callback with the database handle
 ** db. Replace any previously installed collation sequence factory.
 */
-SQLITE_API int sqlite3_collation_needed16(
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
   sqlite3 *db, 
   void *pCollNeededArg, 
   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
 ){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   db->xCollNeeded = 0;
   db->xCollNeeded16 = xCollNeeded16;
@@ -112991,7 +139738,7 @@ SQLITE_API int sqlite3_collation_needed16(
 ** This function is now an anachronism. It used to be used to recover from a
 ** malloc() failure, but SQLite now does this automatically.
 */
-SQLITE_API int sqlite3_global_recover(void){
+SQLITE_API int SQLITE_STDCALL sqlite3_global_recover(void){
   return SQLITE_OK;
 }
 #endif
@@ -113001,17 +139748,21 @@ SQLITE_API int sqlite3_global_recover(void){
 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
 ** by the next COMMIT or ROLLBACK.
-**
-******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
 */
-SQLITE_API int sqlite3_get_autocommit(sqlite3 *db){
+SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
   return db->autoCommit;
 }
 
 /*
-** The following routines are subtitutes for constants SQLITE_CORRUPT,
-** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
-** constants.  They server two purposes:
+** The following routines are substitutes for constants SQLITE_CORRUPT,
+** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
+** constants.  They serve two purposes:
 **
 **   1.  Serve as a convenient place to set a breakpoint in a debugger
 **       to detect when version error conditions occurs.
@@ -113019,28 +139770,33 @@ SQLITE_API int sqlite3_get_autocommit(sqlite3 *db){
 **   2.  Invoke sqlite3_log() to provide the source code location where
 **       a low-level error is first detected.
 */
+static int reportError(int iErr, int lineno, const char *zType){
+  sqlite3_log(iErr, "%s at line %d of [%.10s]",
+              zType, lineno, 20+sqlite3_sourceid());
+  return iErr;
+}
 SQLITE_PRIVATE int sqlite3CorruptError(int lineno){
   testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_CORRUPT,
-              "database corruption at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_CORRUPT;
+  return reportError(SQLITE_CORRUPT, lineno, "database corruption");
 }
 SQLITE_PRIVATE int sqlite3MisuseError(int lineno){
   testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_MISUSE, 
-              "misuse at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_MISUSE;
+  return reportError(SQLITE_MISUSE, lineno, "misuse");
 }
 SQLITE_PRIVATE int sqlite3CantopenError(int lineno){
   testcase( sqlite3GlobalConfig.xLog!=0 );
-  sqlite3_log(SQLITE_CANTOPEN, 
-              "cannot open file at line %d of [%.10s]",
-              lineno, 20+sqlite3_sourceid());
-  return SQLITE_CANTOPEN;
+  return reportError(SQLITE_CANTOPEN, lineno, "cannot open file");
 }
-
+#ifdef SQLITE_DEBUG
+SQLITE_PRIVATE int sqlite3NomemError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_NOMEM, lineno, "OOM");
+}
+SQLITE_PRIVATE int sqlite3IoerrnomemError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  return reportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
+}
+#endif
 
 #ifndef SQLITE_OMIT_DEPRECATED
 /*
@@ -113050,7 +139806,7 @@ SQLITE_PRIVATE int sqlite3CantopenError(int lineno){
 ** SQLite no longer uses thread-specific data so this routine is now a
 ** no-op.  It is retained for historical compatibility.
 */
-SQLITE_API void sqlite3_thread_cleanup(void){
+SQLITE_API void SQLITE_STDCALL sqlite3_thread_cleanup(void){
 }
 #endif
 
@@ -113058,8 +139814,7 @@ SQLITE_API void sqlite3_thread_cleanup(void){
 ** Return meta information about a specific column of a database table.
 ** See comment in sqlite3.h (sqlite.h.in) for details.
 */
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-SQLITE_API int sqlite3_table_column_metadata(
+SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
   sqlite3 *db,                /* Connection handle */
   const char *zDbName,        /* Database name or NULL */
   const char *zTableName,     /* Table name */
@@ -113074,14 +139829,20 @@ SQLITE_API int sqlite3_table_column_metadata(
   char *zErrMsg = 0;
   Table *pTab = 0;
   Column *pCol = 0;
-  int iCol;
-
+  int iCol = 0;
   char const *zDataType = 0;
   char const *zCollSeq = 0;
   int notnull = 0;
   int primarykey = 0;
   int autoinc = 0;
 
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+
   /* Ensure the database schema has been loaded */
   sqlite3_mutex_enter(db->mutex);
   sqlite3BtreeEnterAll(db);
@@ -113098,11 +139859,8 @@ SQLITE_API int sqlite3_table_column_metadata(
   }
 
   /* Find the column for which info is requested */
-  if( sqlite3IsRowid(zColumnName) ){
-    iCol = pTab->iPKey;
-    if( iCol>=0 ){
-      pCol = &pTab->aCol[iCol];
-    }
+  if( zColumnName==0 ){
+    /* Query for existance of table only */
   }else{
     for(iCol=0; iCol<pTab->nCol; iCol++){
       pCol = &pTab->aCol[iCol];
@@ -113111,8 +139869,13 @@ SQLITE_API int sqlite3_table_column_metadata(
       }
     }
     if( iCol==pTab->nCol ){
-      pTab = 0;
-      goto error_out;
+      if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
+        iCol = pTab->iPKey;
+        pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
+      }else{
+        pTab = 0;
+        goto error_out;
+      }
     }
   }
 
@@ -113127,17 +139890,17 @@ SQLITE_API int sqlite3_table_column_metadata(
   **        explicitly declared column. Copy meta information from *pCol.
   */ 
   if( pCol ){
-    zDataType = pCol->zType;
+    zDataType = sqlite3ColumnType(pCol,0);
     zCollSeq = pCol->zColl;
     notnull = pCol->notNull!=0;
-    primarykey  = pCol->isPrimKey!=0;
+    primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
   }else{
     zDataType = "INTEGER";
     primarykey = 1;
   }
   if( !zCollSeq ){
-    zCollSeq = "BINARY";
+    zCollSeq = sqlite3StrBINARY;
   }
 
 error_out:
@@ -113159,18 +139922,17 @@ error_out:
         zColumnName);
     rc = SQLITE_ERROR;
   }
-  sqlite3Error(db, rc, (zErrMsg?"%s":0), zErrMsg);
+  sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
   sqlite3DbFree(db, zErrMsg);
   rc = sqlite3ApiExit(db, rc);
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
-#endif
 
 /*
 ** Sleep for a little while.  Return the amount of time slept.
 */
-SQLITE_API int sqlite3_sleep(int ms){
+SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int ms){
   sqlite3_vfs *pVfs;
   int rc;
   pVfs = sqlite3_vfs_find(0);
@@ -113186,7 +139948,10 @@ SQLITE_API int sqlite3_sleep(int ms){
 /*
 ** Enable or disable the extended result codes.
 */
-SQLITE_API int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3 *db, int onoff){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
   db->errMask = onoff ? 0xffffffff : 0xff;
   sqlite3_mutex_leave(db->mutex);
@@ -113196,48 +139961,51 @@ SQLITE_API int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
 /*
 ** Invoke the xFileControl method on a particular database.
 */
-SQLITE_API int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
+SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
   int rc = SQLITE_ERROR;
-  int iDb;
+  Btree *pBtree;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
   sqlite3_mutex_enter(db->mutex);
-  if( zDbName==0 ){
-    iDb = 0;
-  }else{
-    for(iDb=0; iDb<db->nDb; iDb++){
-      if( strcmp(db->aDb[iDb].zName, zDbName)==0 ) break;
-    }
-  }
-  if( iDb<db->nDb ){
-    Btree *pBtree = db->aDb[iDb].pBt;
-    if( pBtree ){
-      Pager *pPager;
-      sqlite3_file *fd;
-      sqlite3BtreeEnter(pBtree);
-      pPager = sqlite3BtreePager(pBtree);
-      assert( pPager!=0 );
-      fd = sqlite3PagerFile(pPager);
-      assert( fd!=0 );
-      if( op==SQLITE_FCNTL_FILE_POINTER ){
-        *(sqlite3_file**)pArg = fd;
-        rc = SQLITE_OK;
-      }else if( fd->pMethods ){
-        rc = sqlite3OsFileControl(fd, op, pArg);
-      }else{
-        rc = SQLITE_NOTFOUND;
-      }
-      sqlite3BtreeLeave(pBtree);
+  pBtree = sqlite3DbNameToBtree(db, zDbName);
+  if( pBtree ){
+    Pager *pPager;
+    sqlite3_file *fd;
+    sqlite3BtreeEnter(pBtree);
+    pPager = sqlite3BtreePager(pBtree);
+    assert( pPager!=0 );
+    fd = sqlite3PagerFile(pPager);
+    assert( fd!=0 );
+    if( op==SQLITE_FCNTL_FILE_POINTER ){
+      *(sqlite3_file**)pArg = fd;
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_VFS_POINTER ){
+      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
+      *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
+      rc = SQLITE_OK;
+    }else if( fd->pMethods ){
+      rc = sqlite3OsFileControl(fd, op, pArg);
+    }else{
+      rc = SQLITE_NOTFOUND;
     }
+    sqlite3BtreeLeave(pBtree);
   }
   sqlite3_mutex_leave(db->mutex);
-  return rc;   
+  return rc;
 }
 
 /*
 ** Interface to the testing logic.
 */
-SQLITE_API int sqlite3_test_control(int op, ...){
+SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...){
   int rc = 0;
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifdef SQLITE_OMIT_BUILTIN_TEST
+  UNUSED_PARAMETER(op);
+#else
   va_list ap;
   va_start(ap, op);
   switch( op ){
@@ -113266,7 +140034,7 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     ** to the xRandomness method of the default VFS.
     */
     case SQLITE_TESTCTRL_PRNG_RESET: {
-      sqlite3PrngResetState();
+      sqlite3_randomness(0,0);
       break;
     }
 
@@ -113286,6 +140054,28 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     }
 
     /*
+    **  sqlite3_test_control(FAULT_INSTALL, xCallback)
+    **
+    ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
+    ** if xCallback is not NULL.
+    **
+    ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
+    ** is called immediately after installing the new callback and the return
+    ** value from sqlite3FaultSim(0) becomes the return from
+    ** sqlite3_test_control().
+    */
+    case SQLITE_TESTCTRL_FAULT_INSTALL: {
+      /* MSVC is picky about pulling func ptrs from va lists.
+      ** http://support.microsoft.com/kb/47961
+      ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
+      */
+      typedef int(*TESTCALLBACKFUNC_t)(int);
+      sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
+      rc = sqlite3FaultSim(0);
+      break;
+    }
+
+    /*
     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
     **
     ** Register hooks to call to indicate which malloc() failures 
@@ -113311,7 +140101,7 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
     ** an incompatible database file format.  Changing the PENDING byte
     ** while any database connection is open results in undefined and
-    ** dileterious behavior.
+    ** deleterious behavior.
     */
     case SQLITE_TESTCTRL_PENDING_BYTE: {
       rc = PENDING_BYTE;
@@ -113337,7 +140127,7 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     */
     case SQLITE_TESTCTRL_ASSERT: {
       volatile int x = 0;
-      assert( (x = va_arg(ap,int))!=0 );
+      assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
       rc = x;
       break;
     }
@@ -113376,6 +140166,22 @@ SQLITE_API int sqlite3_test_control(int op, ...){
       break;
     }
 
+    /*
+    **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
+    **
+    ** The integer returned reveals the byte-order of the computer on which
+    ** SQLite is running:
+    **
+    **       1     big-endian,    determined at run-time
+    **      10     little-endian, determined at run-time
+    **  432101     big-endian,    determined at compile-time
+    **  123410     little-endian, determined at compile-time
+    */ 
+    case SQLITE_TESTCTRL_BYTEORDER: {
+      rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
+      break;
+    }
+
     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
     **
     ** Set the nReserve size to N for the main database on the database
@@ -113401,8 +140207,7 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     */
     case SQLITE_TESTCTRL_OPTIMIZATIONS: {
       sqlite3 *db = va_arg(ap, sqlite3*);
-      int x = va_arg(ap,int);
-      db->flags = (x & SQLITE_OptMask) | (db->flags & ~SQLITE_OptMask);
+      db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
       break;
     }
 
@@ -113424,15 +140229,6 @@ SQLITE_API int sqlite3_test_control(int op, ...){
     }
 #endif 
 
-    /* sqlite3_test_control(SQLITE_TESTCTRL_PGHDRSZ)
-    **
-    ** Return the size of a pcache header in bytes.
-    */
-    case SQLITE_TESTCTRL_PGHDRSZ: {
-      rc = sizeof(PgHdr);
-      break;
-    }
-
     /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
     **
     ** Pass pFree into sqlite3ScratchFree(). 
@@ -113460,6 +140256,79 @@ SQLITE_API int sqlite3_test_control(int op, ...){
       break;
     }
 
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
+    **
+    ** Set or clear a flag that indicates that the database file is always well-
+    ** formed and never corrupt.  This flag is clear by default, indicating that
+    ** database files might have arbitrary corruption.  Setting the flag during
+    ** testing causes certain assert() statements in the code to be activated
+    ** that demonstrat invariants on well-formed database files.
+    */
+    case SQLITE_TESTCTRL_NEVER_CORRUPT: {
+      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
+      break;
+    }
+
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
+    **
+    ** Set the VDBE coverage callback function to xCallback with context 
+    ** pointer ptr.
+    */
+    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
+#ifdef SQLITE_VDBE_COVERAGE
+      typedef void (*branch_callback)(void*,int,u8,u8);
+      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
+      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
+#endif
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
+    case SQLITE_TESTCTRL_SORTER_MMAP: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      db->nMaxSorterMmap = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
+    **
+    ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
+    ** not.
+    */
+    case SQLITE_TESTCTRL_ISINIT: {
+      if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
+      break;
+    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
+    **
+    ** This test control is used to create imposter tables.  "db" is a pointer
+    ** to the database connection.  dbName is the database name (ex: "main" or
+    ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
+    ** or off.  "tnum" is the root page of the b-tree to which the imposter
+    ** table should connect.
+    **
+    ** Enable imposter mode only when the schema has already been parsed.  Then
+    ** run a single CREATE TABLE statement to construct the imposter table in
+    ** the parsed schema.  Then turn imposter mode back off again.
+    **
+    ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
+    ** the schema to be reparsed the next time it is needed.  This has the
+    ** effect of erasing all imposter tables.
+    */
+    case SQLITE_TESTCTRL_IMPOSTER: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      sqlite3_mutex_enter(db->mutex);
+      db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
+      db->init.busy = db->init.imposterTable = va_arg(ap,int);
+      db->init.newTnum = va_arg(ap,int);
+      if( db->init.busy==0 && db->init.newTnum>0 ){
+        sqlite3ResetAllSchemasOfConnection(db);
+      }
+      sqlite3_mutex_leave(db->mutex);
+      break;
+    }
   }
   va_end(ap);
 #endif /* SQLITE_OMIT_BUILTIN_TEST */
@@ -113477,7 +140346,8 @@ SQLITE_API int sqlite3_test_control(int op, ...){
 ** parameter if it exists.  If the parameter does not exist, this routine
 ** returns a NULL pointer.
 */
-SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
+SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam){
+  if( zFilename==0 || zParam==0 ) return 0;
   zFilename += sqlite3Strlen30(zFilename) + 1;
   while( zFilename[0] ){
     int x = strcmp(zFilename, zParam);
@@ -113488,6 +140358,160 @@ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *
   return 0;
 }
 
+/*
+** Return a boolean value for a query parameter.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  bDflt = bDflt!=0;
+  return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
+}
+
+/*
+** Return a 64-bit integer value for a query parameter.
+*/
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(
+  const char *zFilename,    /* Filename as passed to xOpen */
+  const char *zParam,       /* URI parameter sought */
+  sqlite3_int64 bDflt       /* return if parameter is missing */
+){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  sqlite3_int64 v;
+  if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
+    bDflt = v;
+  }
+  return bDflt;
+}
+
+/*
+** Return the Btree pointer identified by zDbName.  Return NULL if not found.
+*/
+SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
+  int i;
+  for(i=0; i<db->nDb; i++){
+    if( db->aDb[i].pBt
+     && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zName)==0)
+    ){
+      return db->aDb[i].pBt;
+    }
+  }
+  return 0;
+}
+
+/*
+** Return the filename of the database associated with a database
+** connection.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
+}
+
+/*
+** Return 1 if database is read-only or 0 if read/write.  Return -1 if
+** no such database exists.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
+}
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/*
+** Obtain a snapshot handle for the snapshot of database zDb currently 
+** being read by handle db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_snapshot_get(
+  sqlite3 *db, 
+  const char *zDb,
+  sqlite3_snapshot **ppSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+  int iDb;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+
+  iDb = sqlite3FindDbName(db, zDb);
+  if( iDb==0 || iDb>1 ){
+    Btree *pBt = db->aDb[iDb].pBt;
+    if( 0==sqlite3BtreeIsInTrans(pBt) ){
+      rc = sqlite3BtreeBeginTrans(pBt, 0);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Open a read-transaction on the snapshot idendified by pSnapshot.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_snapshot_open(
+  sqlite3 *db, 
+  const char *zDb, 
+  sqlite3_snapshot *pSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( db->autoCommit==0 ){
+    int iDb;
+    iDb = sqlite3FindDbName(db, zDb);
+    if( iDb==0 || iDb>1 ){
+      Btree *pBt = db->aDb[iDb].pBt;
+      if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
+        rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3BtreeBeginTrans(pBt, 0);
+          sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
+        }
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Free a snapshot handle obtained from sqlite3_snapshot_get().
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
+  sqlite3_free(pSnapshot);
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
+
 /************** End of main.c ************************************************/
 /************** Begin file notify.c ******************************************/
 /*
@@ -113505,6 +140529,8 @@ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *
 ** This file contains the implementation of the sqlite3_unlock_notify()
 ** API method and its associated functionality.
 */
+/* #include "sqliteInt.h" */
+/* #include "btreeInt.h" */
 
 /* Omit this entire file if SQLITE_ENABLE_UNLOCK_NOTIFY is not defined. */
 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
@@ -113635,7 +140661,7 @@ static void leaveMutex(void){
 ** on the same "db".  If xNotify==0 then any prior callbacks are immediately
 ** cancelled.
 */
-SQLITE_API int sqlite3_unlock_notify(
+SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
   sqlite3 *db,
   void (*xNotify)(void **, int),
   void *pArg
@@ -113674,7 +140700,7 @@ SQLITE_API int sqlite3_unlock_notify(
 
   leaveMutex();
   assert( !db->mallocFailed );
-  sqlite3Error(db, rc, (rc?"database is deadlocked":0));
+  sqlite3ErrorWithMsg(db, rc, (rc?"database is deadlocked":0));
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }
@@ -113895,7 +140921,7 @@ SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
 ** A doclist is stored like this:
 **
 ** array {
-**   varint docid;
+**   varint docid;          (delta from previous doclist)
 **   array {                (position list for column 0)
 **     varint position;     (2 more than the delta from previous position)
 **   }
@@ -113926,8 +140952,8 @@ SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
 ** at D signals the start of a new column; the 1 at E indicates that the
 ** new column is column number 1.  There are two positions at 12 and 45
 ** (14-2 and 35-2+12).  The 0 at H indicate the end-of-document.  The
-** 234 at I is the next docid.  It has one position 72 (72-2) and then
-** terminates with the 0 at K.
+** 234 at I is the delta to next docid (357).  It has one position 70
+** (72-2) and then terminates with the 0 at K.
 **
 ** A "position-list" is the list of positions for multiple columns for
 ** a single docid.  A "column-list" is the set of positions for a single
@@ -114111,10 +141137,6 @@ SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
 ** will eventually overtake the earlier data and knock it out.  The
 ** query logic likewise merges doclists so that newer data knocks out
 ** older data.
-**
-** TODO(shess) Provide a VACUUM type operation to clear out all
-** deletions and duplications.  This would basically be a forced merge
-** into a single segment.
 */
 
 /************** Include fts3Int.h in the middle of fts3.c ********************/
@@ -114139,6 +141161,12 @@ SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
 # define NDEBUG 1
 #endif
 
+/* FTS3/FTS4 require virtual tables */
+#ifdef SQLITE_OMIT_VIRTUALTABLE
+# undef SQLITE_ENABLE_FTS3
+# undef SQLITE_ENABLE_FTS4
+#endif
+
 /*
 ** FTS4 is really an extension for FTS3.  It is enabled using the
 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
@@ -114152,9 +141180,11 @@ SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
 
 /* If not building as part of the core, include sqlite3ext.h. */
 #ifndef SQLITE_CORE
-SQLITE_API extern const sqlite3_api_routines *sqlite3_api;
+/* # include "sqlite3ext.h"  */
+SQLITE_EXTENSION_INIT3
 #endif
 
+/* #include "sqlite3.h" */
 /************** Include fts3_tokenizer.h in the middle of fts3Int.h **********/
 /************** Begin file fts3_tokenizer.h **********************************/
 /*
@@ -114183,6 +141213,7 @@ SQLITE_API extern const sqlite3_api_routines *sqlite3_api;
 ** If tokenizers are to be allowed to call sqlite3_*() functions, then
 ** we will need a way to register the API consistently.
 */
+/* #include "sqlite3.h" */
 
 /*
 ** Structures used by the tokenizer interface. When a new tokenizer
@@ -114210,7 +141241,7 @@ typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
 struct sqlite3_tokenizer_module {
 
   /*
-  ** Structure version. Should always be set to 0.
+  ** Structure version. Should always be set to 0 or 1.
   */
   int iVersion;
 
@@ -114228,7 +141259,7 @@ struct sqlite3_tokenizer_module {
   ** This method should return either SQLITE_OK (0), or an SQLite error 
   ** code. If SQLITE_OK is returned, then *ppTokenizer should be set
   ** to point at the newly created tokenizer structure. The generic
-  ** sqlite3_tokenizer.pModule variable should not be initialised by
+  ** sqlite3_tokenizer.pModule variable should not be initialized by
   ** this callback. The caller will do so.
   */
   int (*xCreate)(
@@ -114291,6 +141322,15 @@ struct sqlite3_tokenizer_module {
     int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */
     int *piPosition      /* OUT: Number of tokens returned before this one */
   );
+
+  /***********************************************************************
+  ** Methods below this point are only available if iVersion>=1.
+  */
+
+  /* 
+  ** Configure the language id of a tokenizer cursor.
+  */
+  int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);
 };
 
 struct sqlite3_tokenizer {
@@ -114324,7 +141364,7 @@ int fts3_term_cnt(int iTerm, int iCol);
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This is the header file for the generic hash-table implemenation
+** This is the header file for the generic hash-table implementation
 ** used in SQLite.  We've modified it slightly to serve as a standalone
 ** hash table implementation for the full-text indexing module.
 **
@@ -114430,6 +141470,18 @@ SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const voi
 /************** Continuing where we left off in fts3Int.h ********************/
 
 /*
+** This constant determines the maximum depth of an FTS expression tree
+** that the library will create and use. FTS uses recursion to perform 
+** various operations on the query tree, so the disadvantage of a large
+** limit is that it may allow very large queries to use large amounts
+** of stack space (perhaps causing a stack overflow).
+*/
+#ifndef SQLITE_FTS3_MAX_EXPR_DEPTH
+# define SQLITE_FTS3_MAX_EXPR_DEPTH 12
+#endif
+
+
+/*
 ** This constant controls how often segments are merged. Once there are
 ** FTS3_MERGE_COUNT segments of level N, they are merged into a single
 ** segment of level N+1.
@@ -114457,6 +141509,9 @@ SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const voi
 #ifndef MIN
 # define MIN(x,y) ((x)<(y)?(x):(y))
 #endif
+#ifndef MAX
+# define MAX(x,y) ((x)>(y)?(x):(y))
+#endif
 
 /*
 ** Maximum length of a varint encoded integer. The varint format is different
@@ -114509,9 +141564,14 @@ SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const voi
 #ifdef SQLITE_COVERAGE_TEST
 # define ALWAYS(x) (1)
 # define NEVER(X)  (0)
+#elif defined(SQLITE_DEBUG)
+# define ALWAYS(x) sqlite3Fts3Always((x)!=0)
+# define NEVER(x) sqlite3Fts3Never((x)!=0)
+SQLITE_PRIVATE int sqlite3Fts3Always(int b);
+SQLITE_PRIVATE int sqlite3Fts3Never(int b);
 #else
 # define ALWAYS(x) (x)
-# define NEVER(X)  (x)
+# define NEVER(x)  (x)
 #endif
 
 /*
@@ -114521,6 +141581,7 @@ typedef unsigned char u8;         /* 1-byte (or larger) unsigned integer */
 typedef short int i16;            /* 2-byte (or larger) signed integer */
 typedef unsigned int u32;         /* 4-byte unsigned integer */
 typedef sqlite3_uint64 u64;       /* 8-byte unsigned integer */
+typedef sqlite3_int64 i64;        /* 8-byte signed integer */
 
 /*
 ** Macro used to suppress compiler warnings for unused parameters.
@@ -114566,6 +141627,8 @@ typedef struct Fts3DeferredToken Fts3DeferredToken;
 typedef struct Fts3SegReader Fts3SegReader;
 typedef struct Fts3MultiSegReader Fts3MultiSegReader;
 
+typedef struct MatchinfoBuffer MatchinfoBuffer;
+
 /*
 ** A connection to a fulltext index is an instance of the following
 ** structure. The xCreate and xConnect methods create an instance
@@ -114580,38 +141643,47 @@ struct Fts3Table {
   const char *zName;              /* virtual table name */
   int nColumn;                    /* number of named columns in virtual table */
   char **azColumn;                /* column names.  malloced */
+  u8 *abNotindexed;               /* True for 'notindexed' columns */
   sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
   char *zContentTbl;              /* content=xxx option, or NULL */
+  char *zLanguageid;              /* languageid=xxx option, or NULL */
+  int nAutoincrmerge;             /* Value configured by 'automerge' */
+  u32 nLeafAdd;                   /* Number of leaf blocks added this trans */
 
   /* Precompiled statements used by the implementation. Each of these 
   ** statements is run and reset within a single virtual table API call. 
   */
-  sqlite3_stmt *aStmt[27];
+  sqlite3_stmt *aStmt[40];
 
   char *zReadExprlist;
   char *zWriteExprlist;
 
   int nNodeSize;                  /* Soft limit for node size */
-  u8 bHasStat;                    /* True if %_stat table exists */
+  u8 bFts4;                       /* True for FTS4, false for FTS3 */
+  u8 bHasStat;                    /* True if %_stat table exists (2==unknown) */
   u8 bHasDocsize;                 /* True if %_docsize table exists */
   u8 bDescIdx;                    /* True if doclists are in reverse order */
+  u8 bIgnoreSavepoint;            /* True to ignore xSavepoint invocations */
   int nPgsz;                      /* Page size for host database */
   char *zSegmentsTbl;             /* Name of %_segments table */
   sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */
 
-  /* TODO: Fix the first paragraph of this comment.
-  **
-  ** The following hash table is used to buffer pending index updates during
-  ** transactions. Variable nPendingData estimates the memory size of the 
-  ** pending data, including hash table overhead, but not malloc overhead. 
-  ** When nPendingData exceeds nMaxPendingData, the buffer is flushed 
-  ** automatically. Variable iPrevDocid is the docid of the most recently
-  ** inserted record.
+  /* 
+  ** The following array of hash tables is used to buffer pending index 
+  ** updates during transactions. All pending updates buffered at any one
+  ** time must share a common language-id (see the FTS4 langid= feature).
+  ** The current language id is stored in variable iPrevLangid.
   **
   ** A single FTS4 table may have multiple full-text indexes. For each index
   ** there is an entry in the aIndex[] array. Index 0 is an index of all the
   ** terms that appear in the document set. Each subsequent index in aIndex[]
   ** is an index of prefixes of a specific length.
+  **
+  ** Variable nPendingData contains an estimate the memory consumed by the 
+  ** pending data structures, including hash table overhead, but not including
+  ** malloc overhead.  When nPendingData exceeds nMaxPendingData, all hash
+  ** tables are flushed to disk. Variable iPrevDocid is the docid of the most 
+  ** recently inserted record.
   */
   int nIndex;                     /* Size of aIndex[] */
   struct Fts3Index {
@@ -114621,16 +141693,24 @@ struct Fts3Table {
   int nMaxPendingData;            /* Max pending data before flush to disk */
   int nPendingData;               /* Current bytes of pending data */
   sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */
+  int iPrevLangid;                /* Langid of recently inserted document */
+  int bPrevDelete;                /* True if last operation was a delete */
 
 #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
   /* State variables used for validating that the transaction control
   ** methods of the virtual table are called at appropriate times.  These
-  ** values do not contribution to the FTS computation; they are used for
-  ** verifying the SQLite core.
+  ** values do not contribute to FTS functionality; they are used for
+  ** verifying the operation of the SQLite core.
   */
   int inTransaction;     /* True after xBegin but before xCommit/xRollback */
   int mxSavepoint;       /* Largest valid xSavepoint integer */
 #endif
+
+#ifdef SQLITE_TEST
+  /* True to disable the incremental doclist optimization. This is controled
+  ** by special insert command 'test-no-incr-doclist'.  */
+  int bNoIncrDoclist;
+#endif
 };
 
 /*
@@ -114645,6 +141725,7 @@ struct Fts3Cursor {
   u8 isRequireSeek;               /* True if must seek pStmt to %_content row */
   sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */
   Fts3Expr *pExpr;                /* Parsed MATCH query string */
+  int iLangid;                    /* Language being queried for */
   int nPhrase;                    /* Number of matchable phrases in query */
   Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */
   sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */
@@ -114655,11 +141736,10 @@ struct Fts3Cursor {
   int eEvalmode;                  /* An FTS3_EVAL_XX constant */
   int nRowAvg;                    /* Average size of database rows, in pages */
   sqlite3_int64 nDoc;             /* Documents in table */
-
+  i64 iMinDocid;                  /* Minimum docid to return */
+  i64 iMaxDocid;                  /* Maximum docid to return */
   int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
-  u32 *aMatchinfo;                /* Information about most recent match */
-  int nMatchinfo;                 /* Number of elements in aMatchinfo[] */
-  char *zMatchinfo;               /* Matchinfo specification */
+  MatchinfoBuffer *pMIBuffer;     /* Buffer for matchinfo data */
 };
 
 #define FTS3_EVAL_FILTER    0
@@ -114685,6 +141765,15 @@ struct Fts3Cursor {
 #define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
 #define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */
 
+/*
+** The lower 16-bits of the sqlite3_index_info.idxNum value set by
+** the xBestIndex() method contains the Fts3Cursor.eSearch value described
+** above. The upper 16-bits contain a combination of the following
+** bits, used to describe extra constraints on full-text searches.
+*/
+#define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */
+#define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */
+#define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */
 
 struct Fts3Doclist {
   char *aAll;                    /* Array containing doclist (or NULL) */
@@ -114722,6 +141811,11 @@ struct Fts3Phrase {
   int bIncr;                 /* True if doclist is loaded incrementally */
   int iDoclistToken;
 
+  /* Used by sqlite3Fts3EvalPhrasePoslist() if this is a descendent of an
+  ** OR condition.  */
+  char *pOrPoslist;
+  i64 iOrDocid;
+
   /* Variables below this point are populated by fts3_expr.c when parsing 
   ** a MATCH expression. Everything above is part of the evaluation phase. 
   */
@@ -114765,7 +141859,9 @@ struct Fts3Expr {
   u8 bStart;                 /* True if iDocid is valid */
   u8 bDeferred;              /* True if this expression is entirely deferred */
 
-  u32 *aMI;
+  /* The following are used by the fts3_snippet.c module. */
+  int iPhrase;               /* Index of this phrase in matchinfo() results */
+  u32 *aMI;                  /* See above */
 };
 
 /*
@@ -114791,23 +141887,33 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sql
 SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *);
 SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *);
 SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *);
-SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(int, sqlite3_int64,
+SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,
   sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
 SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
   Fts3Table*,int,const char*,int,int,Fts3SegReader**);
 SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *);
-SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, sqlite3_stmt **);
-SQLITE_PRIVATE int sqlite3Fts3ReadLock(Fts3Table *);
+SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
 SQLITE_PRIVATE int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);
 
 SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
 SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);
 
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
 SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
 SQLITE_PRIVATE int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
 SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
 SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
+SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, int *);
+#else
+# define sqlite3Fts3FreeDeferredTokens(x)
+# define sqlite3Fts3DeferToken(x,y,z) SQLITE_OK
+# define sqlite3Fts3CacheDeferredDoclists(x) SQLITE_OK
+# define sqlite3Fts3FreeDeferredDoclists(x)
+# define sqlite3Fts3DeferredTokenList(x,y,z) SQLITE_OK
+#endif
+
 SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *);
+SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *, int *);
 
 /* Special values interpreted by sqlite3SegReaderCursor() */
 #define FTS3_SEGCURSOR_PENDING        -1
@@ -114817,8 +141923,8 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Ft
 SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);
 SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);
 
-SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
-    Fts3Table *, int, int, const char *, int, int, int, Fts3MultiSegReader *);
+SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(Fts3Table *, 
+    int, int, int, const char *, int, int, int, Fts3MultiSegReader *);
 
 /* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
 #define FTS3_SEGMENT_REQUIRE_POS   0x00000001
@@ -114859,7 +141965,14 @@ struct Fts3MultiSegReader {
   int nDoclist;                   /* Size of aDoclist[] in bytes */
 };
 
+SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table*,int,int);
+
+#define fts3GetVarint32(p, piVal) (                                           \
+  (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \
+)
+
 /* fts3.c */
+SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char**,const char*,...);
 SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *, sqlite3_int64);
 SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
 SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *, int *);
@@ -114868,6 +141981,8 @@ SQLITE_PRIVATE void sqlite3Fts3Dequote(char *);
 SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
 SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
 SQLITE_PRIVATE int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
+SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
+SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);
 
 /* fts3_tokenizer.c */
 SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *, int *);
@@ -114883,10 +141998,11 @@ SQLITE_PRIVATE void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const ch
   const char *, const char *, int, int
 );
 SQLITE_PRIVATE void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);
+SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p);
 
 /* fts3_expr.c */
-SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
-  char **, int, int, int, const char *, int, Fts3Expr **
+SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
+  char **, int, int, int, const char *, int, Fts3Expr **, char **
 );
 SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *);
 #ifdef SQLITE_TEST
@@ -114894,6 +142010,10 @@ SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
 SQLITE_PRIVATE int sqlite3Fts3InitTerm(sqlite3 *db);
 #endif
 
+SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,
+  sqlite3_tokenizer_cursor **
+);
+
 /* fts3_aux.c */
 SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db);
 
@@ -114903,11 +142023,19 @@ SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(
     Fts3Table*, Fts3MultiSegReader*, int, const char*, int);
 SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
     Fts3Table *, Fts3MultiSegReader *, sqlite3_int64 *, char **, int *);
-SQLITE_PRIVATE char *sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol); 
+SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol, char **); 
 SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(Fts3Cursor *, Fts3MultiSegReader *, int *);
 SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);
 
-SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, int *);
+/* fts3_tokenize_vtab.c */
+SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);
+
+/* fts3_unicode2.c (functions generated by parsing unicode text files) */
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int, int);
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int);
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int);
+#endif
 
 #endif /* !SQLITE_CORE || SQLITE_ENABLE_FTS3 */
 #endif /* _FTSINT_H */
@@ -114927,7 +142055,9 @@ SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, in
 /* #include <string.h> */
 /* #include <stdarg.h> */
 
+/* #include "fts3.h" */
 #ifndef SQLITE_CORE 
+/* # include "sqlite3ext.h" */
   SQLITE_EXTENSION_INIT1
 #endif
 
@@ -114936,6 +142066,13 @@ static int fts3EvalStart(Fts3Cursor *pCsr);
 static int fts3TermSegReaderCursor(
     Fts3Cursor *, const char *, int, int, Fts3MultiSegReader **);
 
+#ifndef SQLITE_AMALGAMATION
+# if defined(SQLITE_DEBUG)
+SQLITE_PRIVATE int sqlite3Fts3Always(int b) { assert( b ); return b; }
+SQLITE_PRIVATE int sqlite3Fts3Never(int b)  { assert( !b ); return b; }
+# endif
+#endif
+
 /* 
 ** Write a 64-bit variable-length integer to memory starting at p[0].
 ** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
@@ -114953,21 +142090,37 @@ SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
   return (int) (q - (unsigned char *)p);
 }
 
+#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (v & mask1) | ( (*ptr++) << shift );                    \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (*ptr++);                                               \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+
 /* 
 ** Read a 64-bit variable-length integer from memory starting at p[0].
 ** Return the number of bytes read, or 0 on error.
 ** The value is stored in *v.
 */
 SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
-  const unsigned char *q = (const unsigned char *) p;
-  sqlite_uint64 x = 0, y = 1;
-  while( (*q&0x80)==0x80 && q-(unsigned char *)p<FTS3_VARINT_MAX ){
-    x += y * (*q++ & 0x7f);
-    y <<= 7;
-  }
-  x += y * (*q++);
-  *v = (sqlite_int64) x;
-  return (int) (q - (unsigned char *)p);
+  const char *pStart = p;
+  u32 a;
+  u64 b;
+  int shift;
+
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
+  b = (a & 0x0FFFFFFF );
+
+  for(shift=28; shift<=63; shift+=7){
+    u64 c = *p++;
+    b += (c&0x7F) << shift;
+    if( (c & 0x80)==0 ) break;
+  }
+  *v = b;
+  return (int)(p - pStart);
 }
 
 /*
@@ -114975,10 +142128,21 @@ SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
 ** 32-bit integer before it is returned.
 */
 SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *p, int *pi){
- sqlite_int64 i;
- int ret = sqlite3Fts3GetVarint(p, &i);
- *pi = (int) i;
- return ret;
+  u32 a;
+
+#ifndef fts3GetVarint32
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
+#else
+  a = (*p++);
+  assert( a & 0x80 );
+#endif
+
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *pi, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *pi, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *pi, 4);
+  a = (a & 0x0FFFFFFF );
+  *pi = (int)(a | ((u32)(*p & 0x0F) << 28));
+  return 5;
 }
 
 /*
@@ -115018,7 +142182,7 @@ SQLITE_PRIVATE void sqlite3Fts3Dequote(char *z){
     /* If the first byte was a '[', then the close-quote character is a ']' */
     if( quote=='[' ) quote = ']';  
 
-    while( ALWAYS(z[iIn]) ){
+    while( z[iIn] ){
       if( z[iIn]==quote ){
         if( z[iIn+1]!=quote ) break;
         z[iOut++] = quote;
@@ -115088,6 +142252,7 @@ static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
   sqlite3_free(p->zReadExprlist);
   sqlite3_free(p->zWriteExprlist);
   sqlite3_free(p->zContentTbl);
+  sqlite3_free(p->zLanguageid);
 
   /* Invoke the tokenizer destructor to free the tokenizer. */
   p->pTokenizer->pModule->xDestroy(p->pTokenizer);
@@ -115097,6 +142262,17 @@ static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
 }
 
 /*
+** Write an error message into *pzErr
+*/
+SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char **pzErr, const char *zFormat, ...){
+  va_list ap;
+  sqlite3_free(*pzErr);
+  va_start(ap, zFormat);
+  *pzErr = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+}
+
+/*
 ** Construct one or more SQL statements from the format string given
 ** and then evaluate those statements. The success code is written
 ** into *pRc.
@@ -115164,7 +142340,9 @@ static void fts3DeclareVtab(int *pRc, Fts3Table *p){
     int rc;                       /* Return code */
     char *zSql;                   /* SQL statement passed to declare_vtab() */
     char *zCols;                  /* List of user defined columns */
+    const char *zLanguageid;
 
+    zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");
     sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
 
     /* Create a list of user columns for the virtual table */
@@ -115175,7 +142353,8 @@ static void fts3DeclareVtab(int *pRc, Fts3Table *p){
 
     /* Create the whole "CREATE TABLE" statement to pass to SQLite */
     zSql = sqlite3_mprintf(
-        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN)", zCols, p->zName
+        "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)", 
+        zCols, p->zName, zLanguageid
     );
     if( !zCols || !zSql ){
       rc = SQLITE_NOMEM;
@@ -115190,6 +142369,18 @@ static void fts3DeclareVtab(int *pRc, Fts3Table *p){
 }
 
 /*
+** Create the %_stat table if it does not already exist.
+*/
+SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int *pRc, Fts3Table *p){
+  fts3DbExec(pRc, p->db, 
+      "CREATE TABLE IF NOT EXISTS %Q.'%q_stat'"
+          "(id INTEGER PRIMARY KEY, value BLOB);",
+      p->zDb, p->zName
+  );
+  if( (*pRc)==SQLITE_OK ) p->bHasStat = 1;
+}
+
+/*
 ** Create the backing store tables (%_content, %_segments and %_segdir)
 ** required by the FTS3 table passed as the only argument. This is done
 ** as part of the vtab xCreate() method.
@@ -115204,6 +142395,7 @@ static int fts3CreateTables(Fts3Table *p){
   sqlite3 *db = p->db;            /* The database connection */
 
   if( p->zContentTbl==0 ){
+    const char *zLanguageid = p->zLanguageid;
     char *zContentCols;           /* Columns of %_content table */
 
     /* Create a list of user columns for the content table */
@@ -115212,6 +142404,9 @@ static int fts3CreateTables(Fts3Table *p){
       char *z = p->azColumn[i];
       zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
     }
+    if( zLanguageid && zContentCols ){
+      zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);
+    }
     if( zContentCols==0 ) rc = SQLITE_NOMEM;
   
     /* Create the content table */
@@ -115245,11 +142440,9 @@ static int fts3CreateTables(Fts3Table *p){
         p->zDb, p->zName
     );
   }
+  assert( p->bHasStat==p->bFts4 );
   if( p->bHasStat ){
-    fts3DbExec(&rc, db, 
-        "CREATE TABLE %Q.'%q_stat'(id INTEGER PRIMARY KEY, value BLOB);",
-        p->zDb, p->zName
-    );
+    sqlite3Fts3CreateStatTable(&rc, p);
   }
   return rc;
 }
@@ -115331,6 +142524,7 @@ static void fts3Appendf(
     char *z;
     va_start(ap, zFormat);
     z = sqlite3_vmprintf(zFormat, ap);
+    va_end(ap);
     if( z && *pz ){
       char *z2 = sqlite3_mprintf("%s%s", *pz, z);
       sqlite3_free(z);
@@ -115355,7 +142549,7 @@ static void fts3Appendf(
 static char *fts3QuoteId(char const *zInput){
   int nRet;
   char *zRet;
-  nRet = 2 + strlen(zInput)*2 + 1;
+  nRet = 2 + (int)strlen(zInput)*2 + 1;
   zRet = sqlite3_malloc(nRet);
   if( zRet ){
     int i;
@@ -115410,14 +142604,20 @@ static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){
     for(i=0; i<p->nColumn; i++){
       fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
     }
+    if( p->zLanguageid ){
+      fts3Appendf(pRc, &zRet, ", x.%Q", "langid");
+    }
     sqlite3_free(zFree);
   }else{
     fts3Appendf(pRc, &zRet, "rowid");
     for(i=0; i<p->nColumn; i++){
       fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
     }
+    if( p->zLanguageid ){
+      fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);
+    }
   }
-  fts3Appendf(pRc, &zRet, "FROM '%q'.'%q%s' AS x", 
+  fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x", 
       p->zDb,
       (p->zContentTbl ? p->zContentTbl : p->zName),
       (p->zContentTbl ? "" : "_content")
@@ -115460,6 +142660,9 @@ static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
   for(i=0; i<p->nColumn; i++){
     fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
   }
+  if( p->zLanguageid ){
+    fts3Appendf(pRc, &zRet, ", ?");
+  }
   sqlite3_free(zFree);
   return zRet;
 }
@@ -115478,11 +142681,16 @@ static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
 ** This function is used when parsing the "prefix=" FTS4 parameter.
 */
 static int fts3GobbleInt(const char **pp, int *pnOut){
+  const int MAX_NPREFIX = 10000000;
   const char *p;                  /* Iterator pointer */
   int nInt = 0;                   /* Output value */
 
   for(p=*pp; p[0]>='0' && p[0]<='9'; p++){
     nInt = nInt * 10 + (p[0] - '0');
+    if( nInt>MAX_NPREFIX ){
+      nInt = 0;
+      break;
+    }
   }
   if( p==*pp ) return SQLITE_ERROR;
   *pnOut = nInt;
@@ -115525,7 +142733,6 @@ static int fts3PrefixParameter(
 
   aIndex = sqlite3_malloc(sizeof(struct Fts3Index) * nIndex);
   *apIndex = aIndex;
-  *pnIndex = nIndex;
   if( !aIndex ){
     return SQLITE_NOMEM;
   }
@@ -115535,13 +142742,20 @@ static int fts3PrefixParameter(
     const char *p = zParam;
     int i;
     for(i=1; i<nIndex; i++){
-      int nPrefix;
+      int nPrefix = 0;
       if( fts3GobbleInt(&p, &nPrefix) ) return SQLITE_ERROR;
-      aIndex[i].nPrefix = nPrefix;
+      assert( nPrefix>=0 );
+      if( nPrefix==0 ){
+        nIndex--;
+        i--;
+      }else{
+        aIndex[i].nPrefix = nPrefix;
+      }
       p++;
     }
   }
 
+  *pnIndex = nIndex;
   return SQLITE_OK;
 }
 
@@ -115576,7 +142790,8 @@ static int fts3ContentColumns(
   const char *zTbl,               /* Name of content table */
   const char ***pazCol,           /* OUT: Malloc'd array of column names */
   int *pnCol,                     /* OUT: Size of array *pazCol */
-  int *pnStr                      /* OUT: Bytes of string content */
+  int *pnStr,                     /* OUT: Bytes of string content */
+  char **pzErr                    /* OUT: error message */
 ){
   int rc = SQLITE_OK;             /* Return code */
   char *zSql;                     /* "SELECT *" statement on zTbl */  
@@ -115587,6 +142802,9 @@ static int fts3ContentColumns(
     rc = SQLITE_NOMEM;
   }else{
     rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+    if( rc!=SQLITE_OK ){
+      sqlite3Fts3ErrMsg(pzErr, "%s", sqlite3_errmsg(db));
+    }
   }
   sqlite3_free(zSql);
 
@@ -115602,7 +142820,7 @@ static int fts3ContentColumns(
     nCol = sqlite3_column_count(pStmt);
     for(i=0; i<nCol; i++){
       const char *zCol = sqlite3_column_name(pStmt, i);
-      nStr += strlen(zCol) + 1;
+      nStr += (int)strlen(zCol) + 1;
     }
 
     /* Allocate and populate the array to return. */
@@ -115613,7 +142831,7 @@ static int fts3ContentColumns(
       char *p = (char *)&azCol[nCol];
       for(i=0; i<nCol; i++){
         const char *zCol = sqlite3_column_name(pStmt, i);
-        int n = strlen(zCol)+1;
+        int n = (int)strlen(zCol)+1;
         memcpy(p, zCol, n);
         azCol[i] = p;
         p += n;
@@ -115665,7 +142883,7 @@ static int fts3InitVtab(
   const char **aCol;              /* Array of column names */
   sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */
 
-  int nIndex;                     /* Size of aIndex[] array */
+  int nIndex = 0;                 /* Size of aIndex[] array */
   struct Fts3Index *aIndex = 0;   /* Array of indexes for this table */
 
   /* The results of parsing supported FTS4 key=value options: */
@@ -115675,6 +142893,9 @@ static int fts3InitVtab(
   char *zCompress = 0;            /* compress=? parameter (or NULL) */
   char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
   char *zContent = 0;             /* content=? parameter (or NULL) */
+  char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */
+  char **azNotindexed = 0;        /* The set of notindexed= columns */
+  int nNotindexed = 0;            /* Size of azNotindexed[] array */
 
   assert( strlen(argv[0])==4 );
   assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
@@ -115684,9 +142905,19 @@ static int fts3InitVtab(
   nDb = (int)strlen(argv[1]) + 1;
   nName = (int)strlen(argv[2]) + 1;
 
-  aCol = (const char **)sqlite3_malloc(sizeof(const char *) * (argc-2) );
-  if( !aCol ) return SQLITE_NOMEM;
-  memset((void *)aCol, 0, sizeof(const char *) * (argc-2));
+  nByte = sizeof(const char *) * (argc-2);
+  aCol = (const char **)sqlite3_malloc(nByte);
+  if( aCol ){
+    memset((void*)aCol, 0, nByte);
+    azNotindexed = (char **)sqlite3_malloc(nByte);
+  }
+  if( azNotindexed ){
+    memset(azNotindexed, 0, nByte);
+  }
+  if( !aCol || !azNotindexed ){
+    rc = SQLITE_NOMEM;
+    goto fts3_init_out;
+  }
 
   /* Loop through all of the arguments passed by the user to the FTS3/4
   ** module (i.e. all the column names and special arguments). This loop
@@ -115724,7 +142955,9 @@ static int fts3InitVtab(
         { "compress",    8 },     /* 2 -> COMPRESS */
         { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
         { "order",       5 },     /* 4 -> ORDER */
-        { "content",     7 }      /* 5 -> CONTENT */
+        { "content",     7 },     /* 5 -> CONTENT */
+        { "languageid", 10 },     /* 6 -> LANGUAGEID */
+        { "notindexed", 10 }      /* 7 -> NOTINDEXED */
       };
 
       int iOpt;
@@ -115738,13 +142971,13 @@ static int fts3InitVtab(
           }
         }
         if( iOpt==SizeofArray(aFts4Opt) ){
-          *pzErr = sqlite3_mprintf("unrecognized parameter: %s", z);
+          sqlite3Fts3ErrMsg(pzErr, "unrecognized parameter: %s", z);
           rc = SQLITE_ERROR;
         }else{
           switch( iOpt ){
             case 0:               /* MATCHINFO */
               if( strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "fts3", 4) ){
-                *pzErr = sqlite3_mprintf("unrecognized matchinfo: %s", zVal);
+                sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo: %s", zVal);
                 rc = SQLITE_ERROR;
               }
               bNoDocsize = 1;
@@ -115772,18 +143005,29 @@ static int fts3InitVtab(
               if( (strlen(zVal)!=3 || sqlite3_strnicmp(zVal, "asc", 3)) 
                && (strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "desc", 4)) 
               ){
-                *pzErr = sqlite3_mprintf("unrecognized order: %s", zVal);
+                sqlite3Fts3ErrMsg(pzErr, "unrecognized order: %s", zVal);
                 rc = SQLITE_ERROR;
               }
               bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
               break;
 
-            default:              /* CONTENT */
-              assert( iOpt==5 );
-              sqlite3_free(zUncompress);
+            case 5:              /* CONTENT */
+              sqlite3_free(zContent);
               zContent = zVal;
               zVal = 0;
               break;
+
+            case 6:              /* LANGUAGEID */
+              assert( iOpt==6 );
+              sqlite3_free(zLanguageid);
+              zLanguageid = zVal;
+              zVal = 0;
+              break;
+
+            case 7:              /* NOTINDEXED */
+              azNotindexed[nNotindexed++] = zVal;
+              zVal = 0;
+              break;
           }
         }
         sqlite3_free(zVal);
@@ -115812,9 +143056,22 @@ static int fts3InitVtab(
     if( nCol==0 ){
       sqlite3_free((void*)aCol); 
       aCol = 0;
-      rc = fts3ContentColumns(db, argv[1], zContent, &aCol, &nCol, &nString);
+      rc = fts3ContentColumns(db, argv[1], zContent,&aCol,&nCol,&nString,pzErr);
+
+      /* If a languageid= option was specified, remove the language id
+      ** column from the aCol[] array. */ 
+      if( rc==SQLITE_OK && zLanguageid ){
+        int j;
+        for(j=0; j<nCol; j++){
+          if( sqlite3_stricmp(zLanguageid, aCol[j])==0 ){
+            int k;
+            for(k=j; k<nCol; k++) aCol[k] = aCol[k+1];
+            nCol--;
+            break;
+          }
+        }
+      }
     }
-    assert( rc!=SQLITE_OK || nCol>0 );
   }
   if( rc!=SQLITE_OK ) goto fts3_init_out;
 
@@ -115834,7 +143091,7 @@ static int fts3InitVtab(
   rc = fts3PrefixParameter(zPrefix, &nIndex, &aIndex);
   if( rc==SQLITE_ERROR ){
     assert( zPrefix );
-    *pzErr = sqlite3_mprintf("error parsing prefix parameter: %s", zPrefix);
+    sqlite3Fts3ErrMsg(pzErr, "error parsing prefix parameter: %s", zPrefix);
   }
   if( rc!=SQLITE_OK ) goto fts3_init_out;
 
@@ -115842,6 +143099,7 @@ static int fts3InitVtab(
   nByte = sizeof(Fts3Table) +                  /* Fts3Table */
           nCol * sizeof(char *) +              /* azColumn */
           nIndex * sizeof(struct Fts3Index) +  /* aIndex */
+          nCol * sizeof(u8) +                  /* abNotindexed */
           nName +                              /* zName */
           nDb +                                /* zDb */
           nString;                             /* Space for azColumn strings */
@@ -115859,9 +143117,13 @@ static int fts3InitVtab(
   p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
   p->bHasDocsize = (isFts4 && bNoDocsize==0);
   p->bHasStat = isFts4;
+  p->bFts4 = isFts4;
   p->bDescIdx = bDescIdx;
+  p->nAutoincrmerge = 0xff;   /* 0xff means setting unknown */
   p->zContentTbl = zContent;
+  p->zLanguageid = zLanguageid;
   zContent = 0;
+  zLanguageid = 0;
   TESTONLY( p->inTransaction = -1 );
   TESTONLY( p->mxSavepoint = -1 );
 
@@ -115871,9 +143133,10 @@ static int fts3InitVtab(
   for(i=0; i<nIndex; i++){
     fts3HashInit(&p->aIndex[i].hPending, FTS3_HASH_STRING, 1);
   }
+  p->abNotindexed = (u8 *)&p->aIndex[nIndex];
 
   /* Fill in the zName and zDb fields of the vtab structure. */
-  zCsr = (char *)&p->aIndex[nIndex];
+  zCsr = (char *)&p->abNotindexed[nCol];
   p->zName = zCsr;
   memcpy(zCsr, argv[2], nName);
   zCsr += nName;
@@ -115894,10 +143157,31 @@ static int fts3InitVtab(
     assert( zCsr <= &((char *)p)[nByte] );
   }
 
-  if( (zCompress==0)!=(zUncompress==0) ){
+  /* Fill in the abNotindexed array */
+  for(iCol=0; iCol<nCol; iCol++){
+    int n = (int)strlen(p->azColumn[iCol]);
+    for(i=0; i<nNotindexed; i++){
+      char *zNot = azNotindexed[i];
+      if( zNot && n==(int)strlen(zNot)
+       && 0==sqlite3_strnicmp(p->azColumn[iCol], zNot, n) 
+      ){
+        p->abNotindexed[iCol] = 1;
+        sqlite3_free(zNot);
+        azNotindexed[i] = 0;
+      }
+    }
+  }
+  for(i=0; i<nNotindexed; i++){
+    if( azNotindexed[i] ){
+      sqlite3Fts3ErrMsg(pzErr, "no such column: %s", azNotindexed[i]);
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){
     char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
     rc = SQLITE_ERROR;
-    *pzErr = sqlite3_mprintf("missing %s parameter in fts4 constructor", zMiss);
+    sqlite3Fts3ErrMsg(pzErr, "missing %s parameter in fts4 constructor", zMiss);
   }
   p->zReadExprlist = fts3ReadExprList(p, zUncompress, &rc);
   p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);
@@ -115910,6 +143194,13 @@ static int fts3InitVtab(
     rc = fts3CreateTables(p);
   }
 
+  /* Check to see if a legacy fts3 table has been "upgraded" by the
+  ** addition of a %_stat table so that it can use incremental merge.
+  */
+  if( !isFts4 && !isCreate ){
+    p->bHasStat = 2;
+  }
+
   /* Figure out the page-size for the database. This is required in order to
   ** estimate the cost of loading large doclists from the database.  */
   fts3DatabasePageSize(&rc, p);
@@ -115924,7 +143215,10 @@ fts3_init_out:
   sqlite3_free(zCompress);
   sqlite3_free(zUncompress);
   sqlite3_free(zContent);
+  sqlite3_free(zLanguageid);
+  for(i=0; i<nNotindexed; i++) sqlite3_free(azNotindexed[i]);
   sqlite3_free((void *)aCol);
+  sqlite3_free((void *)azNotindexed);
   if( rc!=SQLITE_OK ){
     if( p ){
       fts3DisconnectMethod((sqlite3_vtab *)p);
@@ -115963,6 +143257,32 @@ static int fts3CreateMethod(
   return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
 }
 
+/*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+  if( sqlite3_libversion_number()>=3008002 ){
+    pIdxInfo->estimatedRows = nRow;
+  }
+#endif
+}
+
+/*
+** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support index-info flags. In that case this function is a no-op.
+*/
+static void fts3SetUniqueFlag(sqlite3_index_info *pIdxInfo){
+#if SQLITE_VERSION_NUMBER>=3008012
+  if( sqlite3_libversion_number()>=3008012 ){
+    pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;
+  }
+#endif
+}
+
 /* 
 ** Implementation of the xBestIndex method for FTS3 tables. There
 ** are three possible strategies, in order of preference:
@@ -115976,20 +143296,39 @@ static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
   int i;                          /* Iterator variable */
   int iCons = -1;                 /* Index of constraint to use */
 
+  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
+  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
+  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
+  int iIdx;
+
   /* By default use a full table scan. This is an expensive option,
   ** so search through the constraints to see if a more efficient 
   ** strategy is possible.
   */
   pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
-  pInfo->estimatedCost = 500000;
+  pInfo->estimatedCost = 5000000;
   for(i=0; i<pInfo->nConstraint; i++){
+    int bDocid;                 /* True if this constraint is on docid */
     struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
-    if( pCons->usable==0 ) continue;
+    if( pCons->usable==0 ){
+      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+        /* There exists an unusable MATCH constraint. This means that if
+        ** the planner does elect to use the results of this call as part
+        ** of the overall query plan the user will see an "unable to use
+        ** function MATCH in the requested context" error. To discourage
+        ** this, return a very high cost here.  */
+        pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+        pInfo->estimatedCost = 1e50;
+        fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
+        return SQLITE_OK;
+      }
+      continue;
+    }
+
+    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);
 
     /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
-    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
-     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
-    ){
+    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
       pInfo->idxNum = FTS3_DOCID_SEARCH;
       pInfo->estimatedCost = 1.0;
       iCons = i;
@@ -116010,14 +143349,50 @@ static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
       pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
       pInfo->estimatedCost = 2.0;
       iCons = i;
-      break;
+    }
+
+    /* Equality constraint on the langid column */
+    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
+     && pCons->iColumn==p->nColumn + 2
+    ){
+      iLangidCons = i;
+    }
+
+    if( bDocid ){
+      switch( pCons->op ){
+        case SQLITE_INDEX_CONSTRAINT_GE:
+        case SQLITE_INDEX_CONSTRAINT_GT:
+          iDocidGe = i;
+          break;
+
+        case SQLITE_INDEX_CONSTRAINT_LE:
+        case SQLITE_INDEX_CONSTRAINT_LT:
+          iDocidLe = i;
+          break;
+      }
     }
   }
 
+  /* If using a docid=? or rowid=? strategy, set the UNIQUE flag. */
+  if( pInfo->idxNum==FTS3_DOCID_SEARCH ) fts3SetUniqueFlag(pInfo);
+
+  iIdx = 1;
   if( iCons>=0 ){
-    pInfo->aConstraintUsage[iCons].argvIndex = 1;
+    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
     pInfo->aConstraintUsage[iCons].omit = 1;
   } 
+  if( iLangidCons>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_LANGID;
+    pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
+  } 
+  if( iDocidGe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
+    pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
+  } 
+  if( iDocidLe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
+    pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
+  } 
 
   /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
   ** docid) order. Both ascending and descending are possible. 
@@ -116069,7 +143444,7 @@ static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
   sqlite3Fts3ExprFree(pCsr->pExpr);
   sqlite3Fts3FreeDeferredTokens(pCsr);
   sqlite3_free(pCsr->aDoclist);
-  sqlite3_free(pCsr->aMatchinfo);
+  sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
   assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
   sqlite3_free(pCsr);
   return SQLITE_OK;
@@ -116119,7 +143494,7 @@ static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
       }else{
         rc = sqlite3_reset(pCsr->pStmt);
         if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
-          /* If no row was found and no error has occured, then the %_content
+          /* If no row was found and no error has occurred, then the %_content
           ** table is missing a row that is present in the full-text index.
           ** The data structures are corrupt.  */
           rc = FTS_CORRUPT_VTAB;
@@ -116194,10 +143569,10 @@ static int fts3ScanInteriorNode(
     /* Load the next term on the node into zBuffer. Use realloc() to expand
     ** the size of zBuffer if required.  */
     if( !isFirstTerm ){
-      zCsr += sqlite3Fts3GetVarint32(zCsr, &nPrefix);
+      zCsr += fts3GetVarint32(zCsr, &nPrefix);
     }
     isFirstTerm = 0;
-    zCsr += sqlite3Fts3GetVarint32(zCsr, &nSuffix);
+    zCsr += fts3GetVarint32(zCsr, &nSuffix);
     
     if( nPrefix<0 || nSuffix<0 || &zCsr[nSuffix]>zEnd ){
       rc = FTS_CORRUPT_VTAB;
@@ -116280,18 +143655,18 @@ static int fts3SelectLeaf(
   sqlite3_int64 *piLeaf,          /* Selected leaf node */
   sqlite3_int64 *piLeaf2          /* Selected leaf node */
 ){
-  int rc;                         /* Return code */
+  int rc = SQLITE_OK;             /* Return code */
   int iHeight;                    /* Height of this node in tree */
 
   assert( piLeaf || piLeaf2 );
 
-  sqlite3Fts3GetVarint32(zNode, &iHeight);
+  fts3GetVarint32(zNode, &iHeight);
   rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
   assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
 
   if( rc==SQLITE_OK && iHeight>1 ){
     char *zBlob = 0;              /* Blob read from %_segments table */
-    int nBlob;                    /* Size of zBlob in bytes */
+    int nBlob = 0;                /* Size of zBlob in bytes */
 
     if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
       rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);
@@ -116487,11 +143862,11 @@ static void fts3PoslistMerge(
     int iCol1;         /* The current column index in pp1 */
     int iCol2;         /* The current column index in pp2 */
 
-    if( *p1==POS_COLUMN ) sqlite3Fts3GetVarint32(&p1[1], &iCol1);
+    if( *p1==POS_COLUMN ) fts3GetVarint32(&p1[1], &iCol1);
     else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;
     else iCol1 = 0;
 
-    if( *p2==POS_COLUMN ) sqlite3Fts3GetVarint32(&p2[1], &iCol2);
+    if( *p2==POS_COLUMN ) fts3GetVarint32(&p2[1], &iCol2);
     else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;
     else iCol2 = 0;
 
@@ -116584,11 +143959,11 @@ static int fts3PoslistPhraseMerge(
   assert( p!=0 && *p1!=0 && *p2!=0 );
   if( *p1==POS_COLUMN ){ 
     p1++;
-    p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+    p1 += fts3GetVarint32(p1, &iCol1);
   }
   if( *p2==POS_COLUMN ){ 
     p2++;
-    p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+    p2 += fts3GetVarint32(p2, &iCol2);
   }
 
   while( 1 ){
@@ -116638,9 +144013,9 @@ static int fts3PoslistPhraseMerge(
       if( 0==*p1 || 0==*p2 ) break;
 
       p1++;
-      p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+      p1 += fts3GetVarint32(p1, &iCol1);
       p2++;
-      p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+      p2 += fts3GetVarint32(p2, &iCol2);
     }
 
     /* Advance pointer p1 or p2 (whichever corresponds to the smaller of
@@ -116652,12 +144027,12 @@ static int fts3PoslistPhraseMerge(
       fts3ColumnlistCopy(0, &p1);
       if( 0==*p1 ) break;
       p1++;
-      p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+      p1 += fts3GetVarint32(p1, &iCol1);
     }else{
       fts3ColumnlistCopy(0, &p2);
       if( 0==*p2 ) break;
       p2++;
-      p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+      p2 += fts3GetVarint32(p2, &iCol2);
     }
   }
 
@@ -116901,7 +144276,7 @@ static int fts3DoclistOrMerge(
   }
 
   *paOut = aOut;
-  *pnOut = (p-aOut);
+  *pnOut = (int)(p-aOut);
   assert( *pnOut<=n1+n2+FTS3_VARINT_MAX-1 );
   return SQLITE_OK;
 }
@@ -116918,26 +144293,33 @@ static int fts3DoclistOrMerge(
 **
 ** The right-hand input doclist is overwritten by this function.
 */
-static void fts3DoclistPhraseMerge(
+static int fts3DoclistPhraseMerge(
   int bDescDoclist,               /* True if arguments are desc */
   int nDist,                      /* Distance from left to right (1=adjacent) */
   char *aLeft, int nLeft,         /* Left doclist */
-  char *aRight, int *pnRight      /* IN/OUT: Right/output doclist */
+  char **paRight, int *pnRight    /* IN/OUT: Right/output doclist */
 ){
   sqlite3_int64 i1 = 0;
   sqlite3_int64 i2 = 0;
   sqlite3_int64 iPrev = 0;
+  char *aRight = *paRight;
   char *pEnd1 = &aLeft[nLeft];
   char *pEnd2 = &aRight[*pnRight];
   char *p1 = aLeft;
   char *p2 = aRight;
   char *p;
   int bFirstOut = 0;
-  char *aOut = aRight;
+  char *aOut;
 
   assert( nDist>0 );
-
+  if( bDescDoclist ){
+    aOut = sqlite3_malloc(*pnRight + FTS3_VARINT_MAX);
+    if( aOut==0 ) return SQLITE_NOMEM;
+  }else{
+    aOut = aRight;
+  }
   p = aOut;
+
   fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
   fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
 
@@ -116965,7 +144347,13 @@ static void fts3DoclistPhraseMerge(
     }
   }
 
-  *pnRight = p - aOut;
+  *pnRight = (int)(p - aOut);
+  if( bDescDoclist ){
+    sqlite3_free(aRight);
+    *paRight = aOut;
+  }
+
+  return SQLITE_OK;
 }
 
 /*
@@ -117090,8 +144478,22 @@ static int fts3TermSelectMerge(
 ){
   if( pTS->aaOutput[0]==0 ){
     /* If this is the first term selected, copy the doclist to the output
-    ** buffer using memcpy(). */
-    pTS->aaOutput[0] = sqlite3_malloc(nDoclist);
+    ** buffer using memcpy(). 
+    **
+    ** Add FTS3_VARINT_MAX bytes of unused space to the end of the 
+    ** allocation. This is so as to ensure that the buffer is big enough
+    ** to hold the current doclist AND'd with any other doclist. If the
+    ** doclists are stored in order=ASC order, this padding would not be
+    ** required (since the size of [doclistA AND doclistB] is always less
+    ** than or equal to the size of [doclistA] in that case). But this is
+    ** not true for order=DESC. For example, a doclist containing (1, -1) 
+    ** may be smaller than (-1), as in the first example the -1 may be stored
+    ** as a single-byte delta, whereas in the second it must be stored as a
+    ** FTS3_VARINT_MAX byte varint.
+    **
+    ** Similar padding is added in the fts3DoclistOrMerge() function.
+    */
+    pTS->aaOutput[0] = sqlite3_malloc(nDoclist + FTS3_VARINT_MAX + 1);
     pTS->anOutput[0] = nDoclist;
     if( pTS->aaOutput[0] ){
       memcpy(pTS->aaOutput[0], aDoclist, nDoclist);
@@ -117167,6 +144569,7 @@ static int fts3SegReaderCursorAppend(
 */
 static int fts3SegReaderCursor(
   Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id */
   int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
   int iLevel,                     /* Level of segments to scan */
   const char *zTerm,              /* Term to query for */
@@ -117187,7 +144590,7 @@ static int fts3SegReaderCursor(
   ** calls out here.  */
   if( iLevel<0 && p->aIndex ){
     Fts3SegReader *pSeg = 0;
-    rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix, &pSeg);
+    rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix||isScan, &pSeg);
     if( rc==SQLITE_OK && pSeg ){
       rc = fts3SegReaderCursorAppend(pCsr, pSeg);
     }
@@ -117195,7 +144598,7 @@ static int fts3SegReaderCursor(
 
   if( iLevel!=FTS3_SEGCURSOR_PENDING ){
     if( rc==SQLITE_OK ){
-      rc = sqlite3Fts3AllSegdirs(p, iIndex, iLevel, &pStmt);
+      rc = sqlite3Fts3AllSegdirs(p, iLangid, iIndex, iLevel, &pStmt);
     }
 
     while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
@@ -117218,7 +144621,9 @@ static int fts3SegReaderCursor(
       }
  
       rc = sqlite3Fts3SegReaderNew(pCsr->nSegment+1, 
-          iStartBlock, iLeavesEndBlock, iEndBlock, zRoot, nRoot, &pSeg
+          (isPrefix==0 && isScan==0),
+          iStartBlock, iLeavesEndBlock, 
+          iEndBlock, zRoot, nRoot, &pSeg
       );
       if( rc!=SQLITE_OK ) goto finished;
       rc = fts3SegReaderCursorAppend(pCsr, pSeg);
@@ -117238,6 +144643,7 @@ static int fts3SegReaderCursor(
 */
 SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
   Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language-id to search */
   int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */
   int iLevel,                     /* Level of segments to scan */
   const char *zTerm,              /* Term to query for */
@@ -117255,14 +144661,9 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
   assert( FTS3_SEGCURSOR_ALL<0 && FTS3_SEGCURSOR_PENDING<0 );
   assert( isPrefix==0 || isScan==0 );
 
-  /* "isScan" is only set to true by the ft4aux module, an ordinary
-  ** full-text tables. */
-  assert( isScan==0 || p->aIndex==0 );
-
   memset(pCsr, 0, sizeof(Fts3MultiSegReader));
-
   return fts3SegReaderCursor(
-      p, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr
+      p, iLangid, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr
   );
 }
 
@@ -117274,11 +144675,14 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(
 */
 static int fts3SegReaderCursorAddZero(
   Fts3Table *p,                   /* FTS virtual table handle */
+  int iLangid,
   const char *zTerm,              /* Term to scan doclist of */
   int nTerm,                      /* Number of bytes in zTerm */
   Fts3MultiSegReader *pCsr        /* Fts3MultiSegReader to modify */
 ){
-  return fts3SegReaderCursor(p, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr);
+  return fts3SegReaderCursor(p, 
+      iLangid, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr
+  );
 }
 
 /*
@@ -117314,8 +144718,9 @@ static int fts3TermSegReaderCursor(
       for(i=1; bFound==0 && i<p->nIndex; i++){
         if( p->aIndex[i].nPrefix==nTerm ){
           bFound = 1;
-          rc = sqlite3Fts3SegReaderCursor(
-              p, i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr);
+          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr
+          );
           pSegcsr->bLookup = 1;
         }
       }
@@ -117323,19 +144728,21 @@ static int fts3TermSegReaderCursor(
       for(i=1; bFound==0 && i<p->nIndex; i++){
         if( p->aIndex[i].nPrefix==nTerm+1 ){
           bFound = 1;
-          rc = sqlite3Fts3SegReaderCursor(
-              p, i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
+          rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+              i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
           );
           if( rc==SQLITE_OK ){
-            rc = fts3SegReaderCursorAddZero(p, zTerm, nTerm, pSegcsr);
+            rc = fts3SegReaderCursorAddZero(
+                p, pCsr->iLangid, zTerm, nTerm, pSegcsr
+            );
           }
         }
       }
     }
 
     if( bFound==0 ){
-      rc = sqlite3Fts3SegReaderCursor(
-          p, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
+      rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 
+          0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
       );
       pSegcsr->bLookup = !isPrefix;
     }
@@ -117354,7 +144761,7 @@ static void fts3SegReaderCursorFree(Fts3MultiSegReader *pSegcsr){
 }
 
 /*
-** This function retreives the doclist for the specified term (or term
+** This function retrieves the doclist for the specified term (or term
 ** prefix) from the database.
 */
 static int fts3TermSelect(
@@ -117459,6 +144866,33 @@ static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
 }
 
 /*
+** The following are copied from sqliteInt.h.
+**
+** Constants for the largest and smallest possible 64-bit signed integers.
+** These macros are designed to work correctly on both 32-bit and 64-bit
+** compilers.
+*/
+#ifndef SQLITE_AMALGAMATION
+# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
+# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
+#endif
+
+/*
+** If the numeric type of argument pVal is "integer", then return it
+** converted to a 64-bit signed integer. Otherwise, return a copy of
+** the second parameter, iDefault.
+*/
+static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
+  if( pVal ){
+    int eType = sqlite3_value_numeric_type(pVal);
+    if( eType==SQLITE_INTEGER ){
+      return sqlite3_value_int64(pVal);
+    }
+  }
+  return iDefault;
+}
+
+/*
 ** This is the xFilter interface for the virtual table.  See
 ** the virtual table xFilter method documentation for additional
 ** information.
@@ -117481,56 +144915,72 @@ static int fts3FilterMethod(
   int nVal,                       /* Number of elements in apVal */
   sqlite3_value **apVal           /* Arguments for the indexing scheme */
 ){
-  int rc;
+  int rc = SQLITE_OK;
   char *zSql;                     /* SQL statement used to access %_content */
+  int eSearch;
   Fts3Table *p = (Fts3Table *)pCursor->pVtab;
   Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
 
+  sqlite3_value *pCons = 0;       /* The MATCH or rowid constraint, if any */
+  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
+  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
+  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
+  int iIdx;
+
   UNUSED_PARAMETER(idxStr);
   UNUSED_PARAMETER(nVal);
 
-  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
-  assert( nVal==0 || nVal==1 );
-  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );
+  eSearch = (idxNum & 0x0000FFFF);
+  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
   assert( p->pSegments==0 );
 
+  /* Collect arguments into local variables */
+  iIdx = 0;
+  if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
+  assert( iIdx==nVal );
+
   /* In case the cursor has been used before, clear it now. */
   sqlite3_finalize(pCsr->pStmt);
   sqlite3_free(pCsr->aDoclist);
+  sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
   sqlite3Fts3ExprFree(pCsr->pExpr);
   memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
 
+  /* Set the lower and upper bounds on docids to return */
+  pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
+  pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);
+
   if( idxStr ){
     pCsr->bDesc = (idxStr[0]=='D');
   }else{
     pCsr->bDesc = p->bDescIdx;
   }
-  pCsr->eSearch = (i16)idxNum;
+  pCsr->eSearch = (i16)eSearch;
 
-  if( idxNum!=FTS3_DOCID_SEARCH && idxNum!=FTS3_FULLSCAN_SEARCH ){
-    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
-    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);
+  if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){
+    int iCol = eSearch-FTS3_FULLTEXT_SEARCH;
+    const char *zQuery = (const char *)sqlite3_value_text(pCons);
 
-    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
+    if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){
       return SQLITE_NOMEM;
     }
 
-    rc = sqlite3Fts3ExprParse(p->pTokenizer, p->azColumn, p->bHasStat, 
-        p->nColumn, iCol, zQuery, -1, &pCsr->pExpr
+    pCsr->iLangid = 0;
+    if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);
+
+    assert( p->base.zErrMsg==0 );
+    rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
+        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 
+        &p->base.zErrMsg
     );
     if( rc!=SQLITE_OK ){
-      if( rc==SQLITE_ERROR ){
-        static const char *zErr = "malformed MATCH expression: [%s]";
-        p->base.zErrMsg = sqlite3_mprintf(zErr, zQuery);
-      }
       return rc;
     }
 
-    rc = sqlite3Fts3ReadLock(p);
-    if( rc!=SQLITE_OK ) return rc;
-
     rc = fts3EvalStart(pCsr);
-
     sqlite3Fts3SegmentsClose(p);
     if( rc!=SQLITE_OK ) return rc;
     pCsr->pNextId = pCsr->aDoclist;
@@ -117542,21 +144992,28 @@ static int fts3FilterMethod(
   ** full-text query or docid lookup, the statement retrieves a single
   ** row by docid.
   */
-  if( idxNum==FTS3_FULLSCAN_SEARCH ){
-    zSql = sqlite3_mprintf(
-        "SELECT %s ORDER BY rowid %s",
-        p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
-    );
+  if( eSearch==FTS3_FULLSCAN_SEARCH ){
+    if( pDocidGe || pDocidLe ){
+      zSql = sqlite3_mprintf(
+          "SELECT %s WHERE rowid BETWEEN %lld AND %lld ORDER BY rowid %s",
+          p->zReadExprlist, pCsr->iMinDocid, pCsr->iMaxDocid,
+          (pCsr->bDesc ? "DESC" : "ASC")
+      );
+    }else{
+      zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s", 
+          p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
+      );
+    }
     if( zSql ){
       rc = sqlite3_prepare_v2(p->db, zSql, -1, &pCsr->pStmt, 0);
       sqlite3_free(zSql);
     }else{
       rc = SQLITE_NOMEM;
     }
-  }else if( idxNum==FTS3_DOCID_SEARCH ){
+  }else if( eSearch==FTS3_DOCID_SEARCH ){
     rc = fts3CursorSeekStmt(pCsr, &pCsr->pStmt);
     if( rc==SQLITE_OK ){
-      rc = sqlite3_bind_value(pCsr->pStmt, 1, apVal[0]);
+      rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);
     }
   }
   if( rc!=SQLITE_OK ) return rc;
@@ -117587,10 +145044,17 @@ static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
 /* 
 ** This is the xColumn method, called by SQLite to request a value from
 ** the row that the supplied cursor currently points to.
+**
+** If:
+**
+**   (iCol <  p->nColumn)   -> The value of the iCol'th user column.
+**   (iCol == p->nColumn)   -> Magic column with the same name as the table.
+**   (iCol == p->nColumn+1) -> Docid column
+**   (iCol == p->nColumn+2) -> Langid column
 */
 static int fts3ColumnMethod(
   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
-  sqlite3_context *pContext,      /* Context for sqlite3_result_xxx() calls */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
   int iCol                        /* Index of column to read value from */
 ){
   int rc = SQLITE_OK;             /* Return Code */
@@ -117598,22 +145062,34 @@ static int fts3ColumnMethod(
   Fts3Table *p = (Fts3Table *)pCursor->pVtab;
 
   /* The column value supplied by SQLite must be in range. */
-  assert( iCol>=0 && iCol<=p->nColumn+1 );
+  assert( iCol>=0 && iCol<=p->nColumn+2 );
 
   if( iCol==p->nColumn+1 ){
     /* This call is a request for the "docid" column. Since "docid" is an 
     ** alias for "rowid", use the xRowid() method to obtain the value.
     */
-    sqlite3_result_int64(pContext, pCsr->iPrevId);
+    sqlite3_result_int64(pCtx, pCsr->iPrevId);
   }else if( iCol==p->nColumn ){
     /* The extra column whose name is the same as the table.
-    ** Return a blob which is a pointer to the cursor.
-    */
-    sqlite3_result_blob(pContext, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);
+    ** Return a blob which is a pointer to the cursor.  */
+    sqlite3_result_blob(pCtx, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);
+  }else if( iCol==p->nColumn+2 && pCsr->pExpr ){
+    sqlite3_result_int64(pCtx, pCsr->iLangid);
   }else{
+    /* The requested column is either a user column (one that contains 
+    ** indexed data), or the language-id column.  */
     rc = fts3CursorSeek(0, pCsr);
-    if( rc==SQLITE_OK && sqlite3_data_count(pCsr->pStmt)>(iCol+1) ){
-      sqlite3_result_value(pContext, sqlite3_column_value(pCsr->pStmt, iCol+1));
+
+    if( rc==SQLITE_OK ){
+      if( iCol==p->nColumn+2 ){
+        int iLangid = 0;
+        if( p->zLanguageid ){
+          iLangid = sqlite3_column_int(pCsr->pStmt, p->nColumn+1);
+        }
+        sqlite3_result_int(pCtx, iLangid);
+      }else if( sqlite3_data_count(pCsr->pStmt)>(iCol+1) ){
+        sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));
+      }
     }
   }
 
@@ -117640,23 +145116,88 @@ static int fts3UpdateMethod(
 ** hash-table to the database.
 */
 static int fts3SyncMethod(sqlite3_vtab *pVtab){
-  int rc = sqlite3Fts3PendingTermsFlush((Fts3Table *)pVtab);
-  sqlite3Fts3SegmentsClose((Fts3Table *)pVtab);
+
+  /* Following an incremental-merge operation, assuming that the input
+  ** segments are not completely consumed (the usual case), they are updated
+  ** in place to remove the entries that have already been merged. This
+  ** involves updating the leaf block that contains the smallest unmerged
+  ** entry and each block (if any) between the leaf and the root node. So
+  ** if the height of the input segment b-trees is N, and input segments
+  ** are merged eight at a time, updating the input segments at the end
+  ** of an incremental-merge requires writing (8*(1+N)) blocks. N is usually
+  ** small - often between 0 and 2. So the overhead of the incremental
+  ** merge is somewhere between 8 and 24 blocks. To avoid this overhead
+  ** dwarfing the actual productive work accomplished, the incremental merge
+  ** is only attempted if it will write at least 64 leaf blocks. Hence
+  ** nMinMerge.
+  **
+  ** Of course, updating the input segments also involves deleting a bunch
+  ** of blocks from the segments table. But this is not considered overhead
+  ** as it would also be required by a crisis-merge that used the same input 
+  ** segments.
+  */
+  const u32 nMinMerge = 64;       /* Minimum amount of incr-merge work to do */
+
+  Fts3Table *p = (Fts3Table*)pVtab;
+  int rc = sqlite3Fts3PendingTermsFlush(p);
+
+  if( rc==SQLITE_OK 
+   && p->nLeafAdd>(nMinMerge/16) 
+   && p->nAutoincrmerge && p->nAutoincrmerge!=0xff
+  ){
+    int mxLevel = 0;              /* Maximum relative level value in db */
+    int A;                        /* Incr-merge parameter A */
+
+    rc = sqlite3Fts3MaxLevel(p, &mxLevel);
+    assert( rc==SQLITE_OK || mxLevel==0 );
+    A = p->nLeafAdd * mxLevel;
+    A += (A/2);
+    if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, p->nAutoincrmerge);
+  }
+  sqlite3Fts3SegmentsClose(p);
+  return rc;
+}
+
+/*
+** If it is currently unknown whether or not the FTS table has an %_stat
+** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat
+** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code
+** if an error occurs.
+*/
+static int fts3SetHasStat(Fts3Table *p){
+  int rc = SQLITE_OK;
+  if( p->bHasStat==2 ){
+    const char *zFmt ="SELECT 1 FROM %Q.sqlite_master WHERE tbl_name='%q_stat'";
+    char *zSql = sqlite3_mprintf(zFmt, p->zDb, p->zName);
+    if( zSql ){
+      sqlite3_stmt *pStmt = 0;
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      if( rc==SQLITE_OK ){
+        int bHasStat = (sqlite3_step(pStmt)==SQLITE_ROW);
+        rc = sqlite3_finalize(pStmt);
+        if( rc==SQLITE_OK ) p->bHasStat = bHasStat;
+      }
+      sqlite3_free(zSql);
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
   return rc;
 }
 
 /*
-** Implementation of xBegin() method. This is a no-op.
+** Implementation of xBegin() method. 
 */
 static int fts3BeginMethod(sqlite3_vtab *pVtab){
-  TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+  Fts3Table *p = (Fts3Table*)pVtab;
   UNUSED_PARAMETER(pVtab);
   assert( p->pSegments==0 );
   assert( p->nPendingData==0 );
   assert( p->inTransaction!=1 );
   TESTONLY( p->inTransaction = 1 );
   TESTONLY( p->mxSavepoint = -1; );
-  return SQLITE_OK;
+  p->nLeafAdd = 0;
+  return fts3SetHasStat(p);
 }
 
 /*
@@ -117698,11 +145239,31 @@ static void fts3ReversePoslist(char *pStart, char **ppPoslist){
   char *p = &(*ppPoslist)[-2];
   char c = 0;
 
+  /* Skip backwards passed any trailing 0x00 bytes added by NearTrim() */
   while( p>pStart && (c=*p--)==0 );
+
+  /* Search backwards for a varint with value zero (the end of the previous 
+  ** poslist). This is an 0x00 byte preceded by some byte that does not
+  ** have the 0x80 bit set.  */
   while( p>pStart && (*p & 0x80) | c ){ 
     c = *p--; 
   }
-  if( p>pStart ){ p = &p[2]; }
+  assert( p==pStart || c==0 );
+
+  /* At this point p points to that preceding byte without the 0x80 bit
+  ** set. So to find the start of the poslist, skip forward 2 bytes then
+  ** over a varint. 
+  **
+  ** Normally. The other case is that p==pStart and the poslist to return
+  ** is the first in the doclist. In this case do not skip forward 2 bytes.
+  ** The second part of the if condition (c==0 && *ppPoslist>&p[2])
+  ** is required for cases where the first byte of a doclist and the
+  ** doclist is empty. For example, if the first docid is 10, a doclist
+  ** that begins with:
+  **
+  **   0x0A 0x00 <next docid delta varint>
+  */
+  if( p>pStart || (c==0 && *ppPoslist>&p[2]) ){ p = &p[2]; }
   while( *p++&0x80 );
   *ppPoslist = p;
 }
@@ -117773,6 +145334,8 @@ static void fts3SnippetFunc(
   }
   if( !zEllipsis || !zEnd || !zStart ){
     sqlite3_result_error_nomem(pContext);
+  }else if( nToken==0 ){
+    sqlite3_result_text(pContext, "", -1, SQLITE_STATIC);
   }else if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
     sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis, iCol, nToken);
   }
@@ -117905,6 +145468,10 @@ static int fts3RenameMethod(
   sqlite3 *db = p->db;            /* Database connection */
   int rc;                         /* Return Code */
 
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  rc = fts3SetHasStat(p);
+  
   /* As it happens, the pending terms table is always empty here. This is
   ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction 
   ** always opens a savepoint transaction. And the xSavepoint() method 
@@ -117912,7 +145479,9 @@ static int fts3RenameMethod(
   ** PendingTermsFlush() in in case that changes.
   */
   assert( p->nPendingData==0 );
-  rc = sqlite3Fts3PendingTermsFlush(p);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3PendingTermsFlush(p);
+  }
 
   if( p->zContentTbl==0 ){
     fts3DbExec(&rc, db,
@@ -117950,11 +145519,15 @@ static int fts3RenameMethod(
 ** Flush the contents of the pending-terms table to disk.
 */
 static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  int rc = SQLITE_OK;
   UNUSED_PARAMETER(iSavepoint);
   assert( ((Fts3Table *)pVtab)->inTransaction );
   assert( ((Fts3Table *)pVtab)->mxSavepoint < iSavepoint );
   TESTONLY( ((Fts3Table *)pVtab)->mxSavepoint = iSavepoint );
-  return fts3SyncMethod(pVtab);
+  if( ((Fts3Table *)pVtab)->bIgnoreSavepoint==0 ){
+    rc = fts3SyncMethod(pVtab);
+  }
+  return rc;
 }
 
 /*
@@ -118036,12 +145609,15 @@ static void hashDestroy(void *p){
 */
 SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
 SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const**ppModule);
+#endif
 #ifdef SQLITE_ENABLE_ICU
 SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
 #endif
 
 /*
-** Initialise the fts3 extension. If this extension is built as part
+** Initialize the fts3 extension. If this extension is built as part
 ** of the sqlite library, then this function is called directly by
 ** SQLite. If fts3 is built as a dynamically loadable extension, this
 ** function is called by the sqlite3_extension_init() entry point.
@@ -118051,12 +145627,19 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){
   Fts3Hash *pHash = 0;
   const sqlite3_tokenizer_module *pSimple = 0;
   const sqlite3_tokenizer_module *pPorter = 0;
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+  const sqlite3_tokenizer_module *pUnicode = 0;
+#endif
 
 #ifdef SQLITE_ENABLE_ICU
   const sqlite3_tokenizer_module *pIcu = 0;
   sqlite3Fts3IcuTokenizerModule(&pIcu);
 #endif
 
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+  sqlite3Fts3UnicodeTokenizer(&pUnicode);
+#endif
+
 #ifdef SQLITE_TEST
   rc = sqlite3Fts3InitTerm(db);
   if( rc!=SQLITE_OK ) return rc;
@@ -118068,7 +145651,7 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){
   sqlite3Fts3SimpleTokenizerModule(&pSimple);
   sqlite3Fts3PorterTokenizerModule(&pPorter);
 
-  /* Allocate and initialise the hash-table used to store tokenizers. */
+  /* Allocate and initialize the hash-table used to store tokenizers. */
   pHash = sqlite3_malloc(sizeof(Fts3Hash));
   if( !pHash ){
     rc = SQLITE_NOMEM;
@@ -118080,6 +145663,10 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){
   if( rc==SQLITE_OK ){
     if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)
      || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+     || sqlite3Fts3HashInsert(pHash, "unicode61", 10, (void *)pUnicode) 
+#endif
 #ifdef SQLITE_ENABLE_ICU
      || (pIcu && sqlite3Fts3HashInsert(pHash, "icu", 4, (void *)pIcu))
 #endif
@@ -118114,9 +145701,13 @@ SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){
           db, "fts4", &fts3Module, (void *)pHash, 0
       );
     }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3InitTok(db, (void *)pHash);
+    }
     return rc;
   }
 
+
   /* An error has occurred. Delete the hash table and return the error code. */
   assert( rc!=SQLITE_OK );
   if( pHash ){
@@ -118180,14 +145771,17 @@ static void fts3EvalAllocateReaders(
 ** This function assumes that pList points to a buffer allocated using
 ** sqlite3_malloc(). This function takes responsibility for eventually
 ** freeing the buffer.
+**
+** SQLITE_OK is returned if successful, or SQLITE_NOMEM if an error occurs.
 */
-static void fts3EvalPhraseMergeToken(
+static int fts3EvalPhraseMergeToken(
   Fts3Table *pTab,                /* FTS Table pointer */
   Fts3Phrase *p,                  /* Phrase to merge pList/nList into */
   int iToken,                     /* Token pList/nList corresponds to */
   char *pList,                    /* Pointer to doclist */
   int nList                       /* Number of bytes in pList */
 ){
+  int rc = SQLITE_OK;
   assert( iToken!=p->iDoclistToken );
 
   if( pList==0 ){
@@ -118226,13 +145820,16 @@ static void fts3EvalPhraseMergeToken(
       nDiff = p->iDoclistToken - iToken;
     }
 
-    fts3DoclistPhraseMerge(pTab->bDescIdx, nDiff, pLeft, nLeft, pRight,&nRight);
+    rc = fts3DoclistPhraseMerge(
+        pTab->bDescIdx, nDiff, pLeft, nLeft, &pRight, &nRight
+    );
     sqlite3_free(pLeft);
     p->doclist.aAll = pRight;
     p->doclist.nAll = nRight;
   }
 
   if( iToken>p->iDoclistToken ) p->iDoclistToken = iToken;
+  return rc;
 }
 
 /*
@@ -118258,7 +145855,7 @@ static int fts3EvalPhraseLoad(
       char *pThis = 0;
       rc = fts3TermSelect(pTab, pToken, p->iColumn, &nThis, &pThis);
       if( rc==SQLITE_OK ){
-        fts3EvalPhraseMergeToken(pTab, p, iToken, pThis, nThis);
+        rc = fts3EvalPhraseMergeToken(pTab, p, iToken, pThis, nThis);
       }
     }
     assert( pToken->pSegcsr==0 );
@@ -118314,7 +145911,7 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
         fts3PoslistPhraseMerge(&aOut, iToken-iPrev, 0, 1, &p1, &p2);
         sqlite3_free(aPoslist);
         aPoslist = pList;
-        nPoslist = aOut - aPoslist;
+        nPoslist = (int)(aOut - aPoslist);
         if( nPoslist==0 ){
           sqlite3_free(aPoslist);
           pPhrase->doclist.pList = 0;
@@ -118358,7 +145955,7 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
       pPhrase->doclist.pList = aOut;
       if( fts3PoslistPhraseMerge(&aOut, nDistance, 0, 1, &p1, &p2) ){
         pPhrase->doclist.bFreeList = 1;
-        pPhrase->doclist.nList = (aOut - pPhrase->doclist.pList);
+        pPhrase->doclist.nList = (int)(aOut - pPhrase->doclist.pList);
       }else{
         sqlite3_free(aOut);
         pPhrase->doclist.pList = 0;
@@ -118372,6 +145969,12 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
 }
 
 /*
+** Maximum number of tokens a phrase may have to be considered for the
+** incremental doclists strategy.
+*/
+#define MAX_INCR_PHRASE_TOKENS 4
+
+/*
 ** This function is called for each Fts3Phrase in a full-text query 
 ** expression to initialize the mechanism for returning rows. Once this
 ** function has been called successfully on an Fts3Phrase, it may be
@@ -118384,23 +145987,42 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
 ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
 */
 static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){
-  int rc;                         /* Error code */
-  Fts3PhraseToken *pFirst = &p->aToken[0];
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;             /* Error code */
+  int i;
 
-  if( pCsr->bDesc==pTab->bDescIdx 
-   && bOptOk==1 
-   && p->nToken==1 
-   && pFirst->pSegcsr 
-   && pFirst->pSegcsr->bLookup 
-   && pFirst->bFirst==0
-  ){
+  /* Determine if doclists may be loaded from disk incrementally. This is
+  ** possible if the bOptOk argument is true, the FTS doclists will be
+  ** scanned in forward order, and the phrase consists of 
+  ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
+  ** tokens or prefix tokens that cannot use a prefix-index.  */
+  int bHaveIncr = 0;
+  int bIncrOk = (bOptOk 
+   && pCsr->bDesc==pTab->bDescIdx 
+   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
+#ifdef SQLITE_TEST
+   && pTab->bNoIncrDoclist==0
+#endif
+  );
+  for(i=0; bIncrOk==1 && i<p->nToken; i++){
+    Fts3PhraseToken *pToken = &p->aToken[i];
+    if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
+      bIncrOk = 0;
+    }
+    if( pToken->pSegcsr ) bHaveIncr = 1;
+  }
+
+  if( bIncrOk && bHaveIncr ){
     /* Use the incremental approach. */
     int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);
-    rc = sqlite3Fts3MsrIncrStart(
-        pTab, pFirst->pSegcsr, iCol, pFirst->z, pFirst->n);
+    for(i=0; rc==SQLITE_OK && i<p->nToken; i++){
+      Fts3PhraseToken *pToken = &p->aToken[i];
+      Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;
+      if( pSegcsr ){
+        rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);
+      }
+    }
     p->bIncr = 1;
-
   }else{
     /* Load the full doclist for the phrase into memory. */
     rc = fts3EvalPhraseLoad(pCsr, p);
@@ -118427,7 +146049,7 @@ SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(
   int nDoclist,                   /* Length of aDoclist in bytes */
   char **ppIter,                  /* IN/OUT: Iterator pointer */
   sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */
-  int *pnList,                    /* IN/OUT: List length pointer */
+  int *pnList,                    /* OUT: List length pointer */
   u8 *pbEof                       /* OUT: End-of-file flag */
 ){
   char *p = *ppIter;
@@ -118454,7 +146076,7 @@ SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(
       iMul = (bDescIdx ? -1 : 1);
     }
 
-    *pnList = pEnd - pNext;
+    *pnList = (int)(pEnd - pNext);
     *ppIter = pNext;
     *piDocid = iDocid;
   }else{
@@ -118468,22 +146090,168 @@ SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(
     }else{
       char *pSave = p;
       fts3ReversePoslist(aDoclist, &p);
-      *pnList = (pSave - p);
+      *pnList = (int)(pSave - p);
     }
     *ppIter = p;
   }
 }
 
 /*
-** Attempt to move the phrase iterator to point to the next matching docid. 
+** Iterate forwards through a doclist.
+*/
+SQLITE_PRIVATE void sqlite3Fts3DoclistNext(
+  int bDescIdx,                   /* True if the doclist is desc */
+  char *aDoclist,                 /* Pointer to entire doclist */
+  int nDoclist,                   /* Length of aDoclist in bytes */
+  char **ppIter,                  /* IN/OUT: Iterator pointer */
+  sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */
+  u8 *pbEof                       /* OUT: End-of-file flag */
+){
+  char *p = *ppIter;
+
+  assert( nDoclist>0 );
+  assert( *pbEof==0 );
+  assert( p || *piDocid==0 );
+  assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );
+
+  if( p==0 ){
+    p = aDoclist;
+    p += sqlite3Fts3GetVarint(p, piDocid);
+  }else{
+    fts3PoslistCopy(0, &p);
+    while( p<&aDoclist[nDoclist] && *p==0 ) p++; 
+    if( p>=&aDoclist[nDoclist] ){
+      *pbEof = 1;
+    }else{
+      sqlite3_int64 iVar;
+      p += sqlite3Fts3GetVarint(p, &iVar);
+      *piDocid += ((bDescIdx ? -1 : 1) * iVar);
+    }
+  }
+
+  *ppIter = p;
+}
+
+/*
+** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof
+** to true if EOF is reached.
+*/
+static void fts3EvalDlPhraseNext(
+  Fts3Table *pTab,
+  Fts3Doclist *pDL,
+  u8 *pbEof
+){
+  char *pIter;                            /* Used to iterate through aAll */
+  char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
+ 
+  if( pDL->pNextDocid ){
+    pIter = pDL->pNextDocid;
+  }else{
+    pIter = pDL->aAll;
+  }
+
+  if( pIter>=pEnd ){
+    /* We have already reached the end of this doclist. EOF. */
+    *pbEof = 1;
+  }else{
+    sqlite3_int64 iDelta;
+    pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
+    if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
+      pDL->iDocid += iDelta;
+    }else{
+      pDL->iDocid -= iDelta;
+    }
+    pDL->pList = pIter;
+    fts3PoslistCopy(0, &pIter);
+    pDL->nList = (int)(pIter - pDL->pList);
+
+    /* pIter now points just past the 0x00 that terminates the position-
+    ** list for document pDL->iDocid. However, if this position-list was
+    ** edited in place by fts3EvalNearTrim(), then pIter may not actually
+    ** point to the start of the next docid value. The following line deals
+    ** with this case by advancing pIter past the zero-padding added by
+    ** fts3EvalNearTrim().  */
+    while( pIter<pEnd && *pIter==0 ) pIter++;
+
+    pDL->pNextDocid = pIter;
+    assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
+    *pbEof = 0;
+  }
+}
+
+/*
+** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().
+*/
+typedef struct TokenDoclist TokenDoclist;
+struct TokenDoclist {
+  int bIgnore;
+  sqlite3_int64 iDocid;
+  char *pList;
+  int nList;
+};
+
+/*
+** Token pToken is an incrementally loaded token that is part of a 
+** multi-token phrase. Advance it to the next matching document in the
+** database and populate output variable *p with the details of the new
+** entry. Or, if the iterator has reached EOF, set *pbEof to true.
+**
 ** If an error occurs, return an SQLite error code. Otherwise, return 
 ** SQLITE_OK.
+*/
+static int incrPhraseTokenNext(
+  Fts3Table *pTab,                /* Virtual table handle */
+  Fts3Phrase *pPhrase,            /* Phrase to advance token of */
+  int iToken,                     /* Specific token to advance */
+  TokenDoclist *p,                /* OUT: Docid and doclist for new entry */
+  u8 *pbEof                       /* OUT: True if iterator is at EOF */
+){
+  int rc = SQLITE_OK;
+
+  if( pPhrase->iDoclistToken==iToken ){
+    assert( p->bIgnore==0 );
+    assert( pPhrase->aToken[iToken].pSegcsr==0 );
+    fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);
+    p->pList = pPhrase->doclist.pList;
+    p->nList = pPhrase->doclist.nList;
+    p->iDocid = pPhrase->doclist.iDocid;
+  }else{
+    Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+    assert( pToken->pDeferred==0 );
+    assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );
+    if( pToken->pSegcsr ){
+      assert( p->bIgnore==0 );
+      rc = sqlite3Fts3MsrIncrNext(
+          pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList
+      );
+      if( p->pList==0 ) *pbEof = 1;
+    }else{
+      p->bIgnore = 1;
+    }
+  }
+
+  return rc;
+}
+
+
+/*
+** The phrase iterator passed as the second argument:
+**
+**   * features at least one token that uses an incremental doclist, and 
+**
+**   * does not contain any deferred tokens.
+**
+** Advance it to the next matching documnent in the database and populate
+** the Fts3Doclist.pList and nList fields. 
 **
 ** If there is no "next" entry and no error occurs, then *pbEof is set to
 ** 1 before returning. Otherwise, if no error occurs and the iterator is
 ** successfully advanced, *pbEof is set to 0.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
 */
-static int fts3EvalPhraseNext(
+static int fts3EvalIncrPhraseNext(
   Fts3Cursor *pCsr,               /* FTS Cursor handle */
   Fts3Phrase *p,                  /* Phrase object to advance to next docid */
   u8 *pbEof                       /* OUT: Set to 1 if EOF */
@@ -118491,57 +146259,116 @@ static int fts3EvalPhraseNext(
   int rc = SQLITE_OK;
   Fts3Doclist *pDL = &p->doclist;
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  u8 bEof = 0;
 
-  if( p->bIncr ){
-    assert( p->nToken==1 );
-    assert( pDL->pNextDocid==0 );
+  /* This is only called if it is guaranteed that the phrase has at least
+  ** one incremental token. In which case the bIncr flag is set. */
+  assert( p->bIncr==1 );
+
+  if( p->nToken==1 && p->bIncr ){
     rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr, 
         &pDL->iDocid, &pDL->pList, &pDL->nList
     );
-    if( rc==SQLITE_OK && !pDL->pList ){
-      *pbEof = 1;
+    if( pDL->pList==0 ) bEof = 1;
+  }else{
+    int bDescDoclist = pCsr->bDesc;
+    struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];
+
+    memset(a, 0, sizeof(a));
+    assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );
+    assert( p->iDoclistToken<MAX_INCR_PHRASE_TOKENS );
+
+    while( bEof==0 ){
+      int bMaxSet = 0;
+      sqlite3_int64 iMax = 0;     /* Largest docid for all iterators */
+      int i;                      /* Used to iterate through tokens */
+
+      /* Advance the iterator for each token in the phrase once. */
+      for(i=0; rc==SQLITE_OK && i<p->nToken && bEof==0; i++){
+        rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+        if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){
+          iMax = a[i].iDocid;
+          bMaxSet = 1;
+        }
+      }
+      assert( rc!=SQLITE_OK || (p->nToken>=1 && a[p->nToken-1].bIgnore==0) );
+      assert( rc!=SQLITE_OK || bMaxSet );
+
+      /* Keep advancing iterators until they all point to the same document */
+      for(i=0; i<p->nToken; i++){
+        while( rc==SQLITE_OK && bEof==0 
+            && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0 
+        ){
+          rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+          if( DOCID_CMP(a[i].iDocid, iMax)>0 ){
+            iMax = a[i].iDocid;
+            i = 0;
+          }
+        }
+      }
+
+      /* Check if the current entries really are a phrase match */
+      if( bEof==0 ){
+        int nList = 0;
+        int nByte = a[p->nToken-1].nList;
+        char *aDoclist = sqlite3_malloc(nByte+1);
+        if( !aDoclist ) return SQLITE_NOMEM;
+        memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);
+
+        for(i=0; i<(p->nToken-1); i++){
+          if( a[i].bIgnore==0 ){
+            char *pL = a[i].pList;
+            char *pR = aDoclist;
+            char *pOut = aDoclist;
+            int nDist = p->nToken-1-i;
+            int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);
+            if( res==0 ) break;
+            nList = (int)(pOut - aDoclist);
+          }
+        }
+        if( i==(p->nToken-1) ){
+          pDL->iDocid = iMax;
+          pDL->pList = aDoclist;
+          pDL->nList = nList;
+          pDL->bFreeList = 1;
+          break;
+        }
+        sqlite3_free(aDoclist);
+      }
     }
+  }
+
+  *pbEof = bEof;
+  return rc;
+}
+
+/*
+** Attempt to move the phrase iterator to point to the next matching docid. 
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+*/
+static int fts3EvalPhraseNext(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
+  u8 *pbEof                       /* OUT: Set to 1 if EOF */
+){
+  int rc = SQLITE_OK;
+  Fts3Doclist *pDL = &p->doclist;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+
+  if( p->bIncr ){
+    rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);
   }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){
     sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll, 
         &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof
     );
     pDL->pList = pDL->pNextDocid;
   }else{
-    char *pIter;                            /* Used to iterate through aAll */
-    char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
-    if( pDL->pNextDocid ){
-      pIter = pDL->pNextDocid;
-    }else{
-      pIter = pDL->aAll;
-    }
-
-    if( pIter>=pEnd ){
-      /* We have already reached the end of this doclist. EOF. */
-      *pbEof = 1;
-    }else{
-      sqlite3_int64 iDelta;
-      pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
-      if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
-        pDL->iDocid += iDelta;
-      }else{
-        pDL->iDocid -= iDelta;
-      }
-      pDL->pList = pIter;
-      fts3PoslistCopy(0, &pIter);
-      pDL->nList = (pIter - pDL->pList);
-
-      /* pIter now points just past the 0x00 that terminates the position-
-      ** list for document pDL->iDocid. However, if this position-list was
-      ** edited in place by fts3EvalNearTrim(), then pIter may not actually
-      ** point to the start of the next docid value. The following line deals
-      ** with this case by advancing pIter past the zero-padding added by
-      ** fts3EvalNearTrim().  */
-      while( pIter<pEnd && *pIter==0 ) pIter++;
-
-      pDL->pNextDocid = pIter;
-      assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
-      *pbEof = 0;
-    }
+    fts3EvalDlPhraseNext(pTab, pDL, pbEof);
   }
 
   return rc;
@@ -118566,21 +146393,22 @@ static int fts3EvalPhraseNext(
 static void fts3EvalStartReaders(
   Fts3Cursor *pCsr,               /* FTS Cursor handle */
   Fts3Expr *pExpr,                /* Expression to initialize phrases in */
-  int bOptOk,                     /* True to enable incremental loading */
   int *pRc                        /* IN/OUT: Error code */
 ){
   if( pExpr && SQLITE_OK==*pRc ){
     if( pExpr->eType==FTSQUERY_PHRASE ){
-      int i;
       int nToken = pExpr->pPhrase->nToken;
-      for(i=0; i<nToken; i++){
-        if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;
+      if( nToken ){
+        int i;
+        for(i=0; i<nToken; i++){
+          if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;
+        }
+        pExpr->bDeferred = (i==nToken);
       }
-      pExpr->bDeferred = (i==nToken);
-      *pRc = fts3EvalPhraseStart(pCsr, bOptOk, pExpr->pPhrase);
+      *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);
     }else{
-      fts3EvalStartReaders(pCsr, pExpr->pLeft, bOptOk, pRc);
-      fts3EvalStartReaders(pCsr, pExpr->pRight, bOptOk, pRc);
+      fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);
+      fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);
       pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);
     }
   }
@@ -118822,7 +146650,7 @@ static int fts3EvalSelectDeferred(
       ** overflowing the 32-bit integer it is stored in. */
       if( ii<12 ) nLoad4 = nLoad4*4;
 
-      if( ii==0 || pTC->pPhrase->nToken>1 ){
+      if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){
         /* Either this is the cheapest token in the entire query, or it is
         ** part of a multi-token phrase. Either way, the entire doclist will
         ** (eventually) be loaded into memory. It may as well be now. */
@@ -118832,8 +146660,12 @@ static int fts3EvalSelectDeferred(
         rc = fts3TermSelect(pTab, pToken, pTC->iCol, &nList, &pList);
         assert( rc==SQLITE_OK || pList==0 );
         if( rc==SQLITE_OK ){
+          rc = fts3EvalPhraseMergeToken(
+              pTab, pTC->pPhrase, pTC->iToken,pList,nList
+          );
+        }
+        if( rc==SQLITE_OK ){
           int nCount;
-          fts3EvalPhraseMergeToken(pTab, pTC->pPhrase, pTC->iToken,pList,nList);
           nCount = fts3DoclistCountDocids(
               pTC->pPhrase->doclist.aAll, pTC->pPhrase->doclist.nAll
           );
@@ -118869,7 +146701,8 @@ static int fts3EvalStart(Fts3Cursor *pCsr){
   fts3EvalAllocateReaders(pCsr, pCsr->pExpr, &nToken, &nOr, &rc);
 
   /* Determine which, if any, tokens in the expression should be deferred. */
-  if( rc==SQLITE_OK && nToken>1 && pTab->bHasStat ){
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+  if( rc==SQLITE_OK && nToken>1 && pTab->bFts4 ){
     Fts3TokenAndCost *aTC;
     Fts3Expr **apOr;
     aTC = (Fts3TokenAndCost *)sqlite3_malloc(
@@ -118886,8 +146719,8 @@ static int fts3EvalStart(Fts3Cursor *pCsr){
       Fts3Expr **ppOr = apOr;
 
       fts3EvalTokenCosts(pCsr, 0, pCsr->pExpr, &pTC, &ppOr, &rc);
-      nToken = pTC-aTC;
-      nOr = ppOr-apOr;
+      nToken = (int)(pTC-aTC);
+      nOr = (int)(ppOr-apOr);
 
       if( rc==SQLITE_OK ){
         rc = fts3EvalSelectDeferred(pCsr, 0, aTC, nToken);
@@ -118899,8 +146732,9 @@ static int fts3EvalStart(Fts3Cursor *pCsr){
       sqlite3_free(aTC);
     }
   }
+#endif
 
-  fts3EvalStartReaders(pCsr, pCsr->pExpr, 1, &rc);
+  fts3EvalStartReaders(pCsr, pCsr->pExpr, &rc);
   return rc;
 }
 
@@ -118959,7 +146793,7 @@ static int fts3EvalNearTrim(
     &pOut, aTmp, nParam1, nParam2, paPoslist, &p2
   );
   if( res ){
-    nNew = (pOut - pPhrase->doclist.pList) - 1;
+    nNew = (int)(pOut - pPhrase->doclist.pList) - 1;
     assert( pPhrase->doclist.pList[nNew]=='\0' );
     assert( nNew<=pPhrase->doclist.nList && nNew>0 );
     memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);
@@ -119009,7 +146843,7 @@ static int fts3EvalNearTrim(
 **   2. NEAR is treated as AND. If the expression is "x NEAR y", it is 
 **      advanced to point to the next row that matches "x AND y".
 ** 
-** See fts3EvalTestDeferredAndNear() for details on testing if a row is
+** See sqlite3Fts3EvalTestDeferred() for details on testing if a row is
 ** really a match, taking into account deferred tokens and NEAR operators.
 */
 static void fts3EvalNextRow(
@@ -119056,6 +146890,22 @@ static void fts3EvalNextRow(
           }
           pExpr->iDocid = pLeft->iDocid;
           pExpr->bEof = (pLeft->bEof || pRight->bEof);
+          if( pExpr->eType==FTSQUERY_NEAR && pExpr->bEof ){
+            if( pRight->pPhrase && pRight->pPhrase->doclist.aAll ){
+              Fts3Doclist *pDl = &pRight->pPhrase->doclist;
+              while( *pRc==SQLITE_OK && pRight->bEof==0 ){
+                memset(pDl->pList, 0, pDl->nList);
+                fts3EvalNextRow(pCsr, pRight, pRc);
+              }
+            }
+            if( pLeft->pPhrase && pLeft->pPhrase->doclist.aAll ){
+              Fts3Doclist *pDl = &pLeft->pPhrase->doclist;
+              while( *pRc==SQLITE_OK && pLeft->bEof==0 ){
+                memset(pDl->pList, 0, pDl->nList);
+                fts3EvalNextRow(pCsr, pLeft, pRc);
+              }
+            }
+          }
         }
         break;
       }
@@ -119174,42 +147024,46 @@ static int fts3EvalNearTest(Fts3Expr *pExpr, int *pRc){
       nTmp += p->pRight->pPhrase->doclist.nList;
     }
     nTmp += p->pPhrase->doclist.nList;
-    aTmp = sqlite3_malloc(nTmp*2);
-    if( !aTmp ){
-      *pRc = SQLITE_NOMEM;
+    if( nTmp==0 ){
       res = 0;
     }else{
-      char *aPoslist = p->pPhrase->doclist.pList;
-      int nToken = p->pPhrase->nToken;
+      aTmp = sqlite3_malloc(nTmp*2);
+      if( !aTmp ){
+        *pRc = SQLITE_NOMEM;
+        res = 0;
+      }else{
+        char *aPoslist = p->pPhrase->doclist.pList;
+        int nToken = p->pPhrase->nToken;
 
-      for(p=p->pParent;res && p && p->eType==FTSQUERY_NEAR; p=p->pParent){
-        Fts3Phrase *pPhrase = p->pRight->pPhrase;
-        int nNear = p->nNear;
-        res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
-      }
-  
-      aPoslist = pExpr->pRight->pPhrase->doclist.pList;
-      nToken = pExpr->pRight->pPhrase->nToken;
-      for(p=pExpr->pLeft; p && res; p=p->pLeft){
-        int nNear;
-        Fts3Phrase *pPhrase;
-        assert( p->pParent && p->pParent->pLeft==p );
-        nNear = p->pParent->nNear;
-        pPhrase = (
-            p->eType==FTSQUERY_NEAR ? p->pRight->pPhrase : p->pPhrase
-        );
-        res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+        for(p=p->pParent;res && p && p->eType==FTSQUERY_NEAR; p=p->pParent){
+          Fts3Phrase *pPhrase = p->pRight->pPhrase;
+          int nNear = p->nNear;
+          res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+        }
+
+        aPoslist = pExpr->pRight->pPhrase->doclist.pList;
+        nToken = pExpr->pRight->pPhrase->nToken;
+        for(p=pExpr->pLeft; p && res; p=p->pLeft){
+          int nNear;
+          Fts3Phrase *pPhrase;
+          assert( p->pParent && p->pParent->pLeft==p );
+          nNear = p->pParent->nNear;
+          pPhrase = (
+              p->eType==FTSQUERY_NEAR ? p->pRight->pPhrase : p->pPhrase
+              );
+          res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+        }
       }
-    }
 
-    sqlite3_free(aTmp);
+      sqlite3_free(aTmp);
+    }
   }
 
   return res;
 }
 
 /*
-** This function is a helper function for fts3EvalTestDeferredAndNear().
+** This function is a helper function for sqlite3Fts3EvalTestDeferred().
 ** Assuming no error occurs or has occurred, It returns non-zero if the
 ** expression passed as the second argument matches the row that pCsr 
 ** currently points to, or zero if it does not.
@@ -119282,6 +147136,7 @@ static int fts3EvalTestExpr(
         break;
 
       default: {
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
         if( pCsr->pDeferred 
          && (pExpr->iDocid==pCsr->iPrevId || pExpr->bDeferred)
         ){
@@ -119293,7 +147148,9 @@ static int fts3EvalTestExpr(
           *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);
           bHit = (pPhrase->doclist.pList!=0);
           pExpr->iDocid = pCsr->iPrevId;
-        }else{
+        }else
+#endif
+        {
           bHit = (pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId);
         }
         break;
@@ -119327,7 +147184,7 @@ static int fts3EvalTestExpr(
 ** Or, if no error occurs and it seems the current row does match the FTS
 ** query, return 0.
 */
-static int fts3EvalTestDeferredAndNear(Fts3Cursor *pCsr, int *pRc){
+SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc){
   int rc = *pRc;
   int bMiss = 0;
   if( rc==SQLITE_OK ){
@@ -119374,8 +147231,18 @@ static int fts3EvalNext(Fts3Cursor *pCsr){
       pCsr->isRequireSeek = 1;
       pCsr->isMatchinfoNeeded = 1;
       pCsr->iPrevId = pExpr->iDocid;
-    }while( pCsr->isEof==0 && fts3EvalTestDeferredAndNear(pCsr, &rc) );
+    }while( pCsr->isEof==0 && sqlite3Fts3EvalTestDeferred(pCsr, &rc) );
+  }
+
+  /* Check if the cursor is past the end of the docid range specified
+  ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */
+  if( rc==SQLITE_OK && (
+        (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
+     || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)
+  )){
+    pCsr->isEof = 1;
   }
+
   return rc;
 }
 
@@ -119399,14 +147266,19 @@ static void fts3EvalRestart(
     if( pPhrase ){
       fts3EvalInvalidatePoslist(pPhrase);
       if( pPhrase->bIncr ){
-        assert( pPhrase->nToken==1 );
-        assert( pPhrase->aToken[0].pSegcsr );
-        sqlite3Fts3MsrIncrRestart(pPhrase->aToken[0].pSegcsr);
+        int i;
+        for(i=0; i<pPhrase->nToken; i++){
+          Fts3PhraseToken *pToken = &pPhrase->aToken[i];
+          assert( pToken->pDeferred==0 );
+          if( pToken->pSegcsr ){
+            sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);
+          }
+        }
         *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);
       }
-
       pPhrase->doclist.pNextDocid = 0;
       pPhrase->doclist.iDocid = 0;
+      pPhrase->pOrPoslist = 0;
     }
 
     pExpr->iDocid = 0;
@@ -119449,7 +147321,7 @@ static void fts3EvalUpdateCounts(Fts3Expr *pExpr){
         pExpr->aMI[iCol*3 + 2] += (iCnt>0);
         if( *p==0x00 ) break;
         p++;
-        p += sqlite3Fts3GetVarint32(p, &iCol);
+        p += fts3GetVarint32(p, &iCol);
       }
     }
 
@@ -119520,7 +147392,7 @@ static int fts3EvalGatherStats(
         pCsr->iPrevId = pRoot->iDocid;
       }while( pCsr->isEof==0 
            && pRoot->eType==FTSQUERY_NEAR 
-           && fts3EvalTestDeferredAndNear(pCsr, &rc) 
+           && sqlite3Fts3EvalTestDeferred(pCsr, &rc) 
       );
 
       if( rc==SQLITE_OK && pCsr->isEof==0 ){
@@ -119545,7 +147417,6 @@ static int fts3EvalGatherStats(
         fts3EvalNextRow(pCsr, pRoot, &rc);
         assert( pRoot->bEof==0 );
       }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
-      fts3EvalTestDeferredAndNear(pCsr, &rc);
     }
   }
   return rc;
@@ -119619,7 +147490,7 @@ SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(
 ** of the current row. 
 **
 ** More specifically, the returned buffer contains 1 varint for each 
-** occurence of the phrase in the column, stored using the normal (delta+2) 
+** occurrence of the phrase in the column, stored using the normal (delta+2) 
 ** compression and is terminated by either an 0x01 or 0x00 byte. For example,
 ** if the requested column contains "a b X c d X X" and the position-list
 ** for 'X' is requested, the buffer returned may contain:
@@ -119629,40 +147500,131 @@ SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(
 ** This function works regardless of whether or not the phrase is deferred,
 ** incremental, or neither.
 */
-SQLITE_PRIVATE char *sqlite3Fts3EvalPhrasePoslist(
+SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(
   Fts3Cursor *pCsr,               /* FTS3 cursor object */
   Fts3Expr *pExpr,                /* Phrase to return doclist for */
-  int iCol                        /* Column to return position list for */
+  int iCol,                       /* Column to return position list for */
+  char **ppOut                    /* OUT: Pointer to position list */
 ){
   Fts3Phrase *pPhrase = pExpr->pPhrase;
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
-  char *pIter = pPhrase->doclist.pList;
+  char *pIter;
   int iThis;
+  sqlite3_int64 iDocid;
 
+  /* If this phrase is applies specifically to some column other than 
+  ** column iCol, return a NULL pointer.  */
+  *ppOut = 0;
   assert( iCol>=0 && iCol<pTab->nColumn );
-  if( !pIter 
-   || pExpr->bEof 
-   || pExpr->iDocid!=pCsr->iPrevId
-   || (pPhrase->iColumn<pTab->nColumn && pPhrase->iColumn!=iCol) 
-  ){
-    return 0;
+  if( (pPhrase->iColumn<pTab->nColumn && pPhrase->iColumn!=iCol) ){
+    return SQLITE_OK;
+  }
+
+  iDocid = pExpr->iDocid;
+  pIter = pPhrase->doclist.pList;
+  if( iDocid!=pCsr->iPrevId || pExpr->bEof ){
+    int rc = SQLITE_OK;
+    int bDescDoclist = pTab->bDescIdx;      /* For DOCID_CMP macro */
+    int bOr = 0;
+    u8 bTreeEof = 0;
+    Fts3Expr *p;                  /* Used to iterate from pExpr to root */
+    Fts3Expr *pNear;              /* Most senior NEAR ancestor (or pExpr) */
+    int bMatch;
+
+    /* Check if this phrase descends from an OR expression node. If not, 
+    ** return NULL. Otherwise, the entry that corresponds to docid 
+    ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the
+    ** tree that the node is part of has been marked as EOF, but the node
+    ** itself is not EOF, then it may point to an earlier entry. */
+    pNear = pExpr;
+    for(p=pExpr->pParent; p; p=p->pParent){
+      if( p->eType==FTSQUERY_OR ) bOr = 1;
+      if( p->eType==FTSQUERY_NEAR ) pNear = p;
+      if( p->bEof ) bTreeEof = 1;
+    }
+    if( bOr==0 ) return SQLITE_OK;
+
+    /* This is the descendent of an OR node. In this case we cannot use
+    ** an incremental phrase. Load the entire doclist for the phrase
+    ** into memory in this case.  */
+    if( pPhrase->bIncr ){
+      int bEofSave = pNear->bEof;
+      fts3EvalRestart(pCsr, pNear, &rc);
+      while( rc==SQLITE_OK && !pNear->bEof ){
+        fts3EvalNextRow(pCsr, pNear, &rc);
+        if( bEofSave==0 && pNear->iDocid==iDocid ) break;
+      }
+      assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );
+    }
+    if( bTreeEof ){
+      while( rc==SQLITE_OK && !pNear->bEof ){
+        fts3EvalNextRow(pCsr, pNear, &rc);
+      }
+    }
+    if( rc!=SQLITE_OK ) return rc;
+
+    bMatch = 1;
+    for(p=pNear; p; p=p->pLeft){
+      u8 bEof = 0;
+      Fts3Expr *pTest = p;
+      Fts3Phrase *pPh;
+      assert( pTest->eType==FTSQUERY_NEAR || pTest->eType==FTSQUERY_PHRASE );
+      if( pTest->eType==FTSQUERY_NEAR ) pTest = pTest->pRight;
+      assert( pTest->eType==FTSQUERY_PHRASE );
+      pPh = pTest->pPhrase;
+
+      pIter = pPh->pOrPoslist;
+      iDocid = pPh->iOrDocid;
+      if( pCsr->bDesc==bDescDoclist ){
+        bEof = !pPh->doclist.nAll ||
+          (pIter >= (pPh->doclist.aAll + pPh->doclist.nAll));
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
+          sqlite3Fts3DoclistNext(
+              bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 
+              &pIter, &iDocid, &bEof
+          );
+        }
+      }else{
+        bEof = !pPh->doclist.nAll || (pIter && pIter<=pPh->doclist.aAll);
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
+          int dummy;
+          sqlite3Fts3DoclistPrev(
+              bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 
+              &pIter, &iDocid, &dummy, &bEof
+              );
+        }
+      }
+      pPh->pOrPoslist = pIter;
+      pPh->iOrDocid = iDocid;
+      if( bEof || iDocid!=pCsr->iPrevId ) bMatch = 0;
+    }
+
+    if( bMatch ){
+      pIter = pPhrase->pOrPoslist;
+    }else{
+      pIter = 0;
+    }
   }
+  if( pIter==0 ) return SQLITE_OK;
 
-  assert( pPhrase->doclist.nList>0 );
   if( *pIter==0x01 ){
     pIter++;
-    pIter += sqlite3Fts3GetVarint32(pIter, &iThis);
+    pIter += fts3GetVarint32(pIter, &iThis);
   }else{
     iThis = 0;
   }
   while( iThis<iCol ){
     fts3ColumnlistCopy(0, &pIter);
-    if( *pIter==0x00 ) return 0;
+    if( *pIter==0x00 ) return SQLITE_OK;
     pIter++;
-    pIter += sqlite3Fts3GetVarint32(pIter, &iThis);
+    pIter += fts3GetVarint32(pIter, &iThis);
+  }
+  if( *pIter==0x00 ){
+    pIter = 0;
   }
 
-  return ((iCol==iThis)?pIter:0);
+  *ppOut = ((iCol==iThis)?pIter:0);
+  return SQLITE_OK;
 }
 
 /*
@@ -119685,6 +147647,7 @@ SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *pPhrase){
   }
 }
 
+
 /*
 ** Return SQLITE_CORRUPT_VTAB.
 */
@@ -119698,7 +147661,10 @@ SQLITE_PRIVATE int sqlite3Fts3Corrupt(){
 /*
 ** Initialize API pointer table, if required.
 */
-SQLITE_API int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_fts3_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
@@ -119725,6 +147691,7 @@ SQLITE_API int sqlite3_extension_init(
 ******************************************************************************
 **
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <string.h> */
@@ -119744,6 +147711,7 @@ struct Fts3auxCursor {
   Fts3SegFilter filter;
   char *zStop;
   int nStop;                      /* Byte-length of string zStop */
+  int iLangid;                    /* Language id to query */
   int isEof;                      /* True if cursor is at EOF */
   sqlite3_int64 iRowid;           /* Current rowid */
 
@@ -119758,7 +147726,8 @@ struct Fts3auxCursor {
 /*
 ** Schema of the terms table.
 */
-#define FTS3_TERMS_SCHEMA "CREATE TABLE x(term, col, documents, occurrences)"
+#define FTS3_AUX_SCHEMA \
+  "CREATE TABLE x(term, col, documents, occurrences, languageid HIDDEN)"
 
 /*
 ** This function does all the work for both the xConnect and xCreate methods.
@@ -119783,20 +147752,29 @@ static int fts3auxConnectMethod(
 
   UNUSED_PARAMETER(pUnused);
 
-  /* The user should specify a single argument - the name of an fts3 table. */
-  if( argc!=4 ){
-    *pzErr = sqlite3_mprintf(
-        "wrong number of arguments to fts4aux constructor"
-    );
-    return SQLITE_ERROR;
-  }
+  /* The user should invoke this in one of two forms:
+  **
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table);
+  **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table-db, fts4-table);
+  */
+  if( argc!=4 && argc!=5 ) goto bad_args;
 
   zDb = argv[1]; 
-  nDb = strlen(zDb);
-  zFts3 = argv[3];
-  nFts3 = strlen(zFts3);
+  nDb = (int)strlen(zDb);
+  if( argc==5 ){
+    if( nDb==4 && 0==sqlite3_strnicmp("temp", zDb, 4) ){
+      zDb = argv[3]; 
+      nDb = (int)strlen(zDb);
+      zFts3 = argv[4];
+    }else{
+      goto bad_args;
+    }
+  }else{
+    zFts3 = argv[3];
+  }
+  nFts3 = (int)strlen(zFts3);
 
-  rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA);
+  rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA);
   if( rc!=SQLITE_OK ) return rc;
 
   nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
@@ -119816,6 +147794,10 @@ static int fts3auxConnectMethod(
 
   *ppVtab = (sqlite3_vtab *)p;
   return SQLITE_OK;
+
+ bad_args:
+  sqlite3Fts3ErrMsg(pzErr, "invalid arguments to fts4aux constructor");
+  return SQLITE_ERROR;
 }
 
 /*
@@ -119852,6 +147834,8 @@ static int fts3auxBestIndexMethod(
   int iEq = -1;
   int iGe = -1;
   int iLe = -1;
+  int iLangid = -1;
+  int iNext = 1;                  /* Next free argvIndex value */
 
   UNUSED_PARAMETER(pVTab);
 
@@ -119863,36 +147847,48 @@ static int fts3auxBestIndexMethod(
     pInfo->orderByConsumed = 1;
   }
 
-  /* Search for equality and range constraints on the "term" column. */
+  /* Search for equality and range constraints on the "term" column. 
+  ** And equality constraints on the hidden "languageid" column. */
   for(i=0; i<pInfo->nConstraint; i++){
-    if( pInfo->aConstraint[i].usable && pInfo->aConstraint[i].iColumn==0 ){
+    if( pInfo->aConstraint[i].usable ){
       int op = pInfo->aConstraint[i].op;
-      if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
+      int iCol = pInfo->aConstraint[i].iColumn;
+
+      if( iCol==0 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
+      }
+      if( iCol==4 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iLangid = i;
+      }
     }
   }
 
   if( iEq>=0 ){
     pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT;
-    pInfo->aConstraintUsage[iEq].argvIndex = 1;
+    pInfo->aConstraintUsage[iEq].argvIndex = iNext++;
     pInfo->estimatedCost = 5;
   }else{
     pInfo->idxNum = 0;
     pInfo->estimatedCost = 20000;
     if( iGe>=0 ){
       pInfo->idxNum += FTS4AUX_GE_CONSTRAINT;
-      pInfo->aConstraintUsage[iGe].argvIndex = 1;
+      pInfo->aConstraintUsage[iGe].argvIndex = iNext++;
       pInfo->estimatedCost /= 2;
     }
     if( iLe>=0 ){
       pInfo->idxNum += FTS4AUX_LE_CONSTRAINT;
-      pInfo->aConstraintUsage[iLe].argvIndex = 1 + (iGe>=0);
+      pInfo->aConstraintUsage[iLe].argvIndex = iNext++;
       pInfo->estimatedCost /= 2;
     }
   }
+  if( iLangid>=0 ){
+    pInfo->aConstraintUsage[iLangid].argvIndex = iNext++;
+    pInfo->estimatedCost--;
+  }
 
   return SQLITE_OK;
 }
@@ -120052,7 +148048,14 @@ static int fts3auxFilterMethod(
   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
   Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
   int rc;
-  int isScan;
+  int isScan = 0;
+  int iLangVal = 0;               /* Language id to query */
+
+  int iEq = -1;                   /* Index of term=? value in apVal */
+  int iGe = -1;                   /* Index of term>=? value in apVal */
+  int iLe = -1;                   /* Index of term<=? value in apVal */
+  int iLangid = -1;               /* Index of languageid=? value in apVal */
+  int iNext = 0;
 
   UNUSED_PARAMETER(nVal);
   UNUSED_PARAMETER(idxStr);
@@ -120062,7 +148065,21 @@ static int fts3auxFilterMethod(
        || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT
        || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT)
   );
-  isScan = (idxNum!=FTS4AUX_EQ_CONSTRAINT);
+
+  if( idxNum==FTS4AUX_EQ_CONSTRAINT ){
+    iEq = iNext++;
+  }else{
+    isScan = 1;
+    if( idxNum & FTS4AUX_GE_CONSTRAINT ){
+      iGe = iNext++;
+    }
+    if( idxNum & FTS4AUX_LE_CONSTRAINT ){
+      iLe = iNext++;
+    }
+  }
+  if( iNext<nVal ){
+    iLangid = iNext++;
+  }
 
   /* In case this cursor is being reused, close and zero it. */
   testcase(pCsr->filter.zTerm);
@@ -120074,22 +148091,35 @@ static int fts3auxFilterMethod(
   pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
   if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;
 
-  if( idxNum&(FTS4AUX_EQ_CONSTRAINT|FTS4AUX_GE_CONSTRAINT) ){
+  if( iEq>=0 || iGe>=0 ){
     const unsigned char *zStr = sqlite3_value_text(apVal[0]);
+    assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) );
     if( zStr ){
       pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);
       pCsr->filter.nTerm = sqlite3_value_bytes(apVal[0]);
       if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;
     }
   }
-  if( idxNum&FTS4AUX_LE_CONSTRAINT ){
-    int iIdx = (idxNum&FTS4AUX_GE_CONSTRAINT) ? 1 : 0;
-    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iIdx]));
-    pCsr->nStop = sqlite3_value_bytes(apVal[iIdx]);
+
+  if( iLe>=0 ){
+    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe]));
+    pCsr->nStop = sqlite3_value_bytes(apVal[iLe]);
     if( pCsr->zStop==0 ) return SQLITE_NOMEM;
   }
+  
+  if( iLangid>=0 ){
+    iLangVal = sqlite3_value_int(apVal[iLangid]);
+
+    /* If the user specified a negative value for the languageid, use zero
+    ** instead. This works, as the "languageid=?" constraint will also
+    ** be tested by the VDBE layer. The test will always be false (since
+    ** this module will not return a row with a negative languageid), and
+    ** so the overall query will return zero rows.  */
+    if( iLangVal<0 ) iLangVal = 0;
+  }
+  pCsr->iLangid = iLangVal;
 
-  rc = sqlite3Fts3SegReaderCursor(pFts3, 0, FTS3_SEGCURSOR_ALL,
+  rc = sqlite3Fts3SegReaderCursor(pFts3, iLangVal, 0, FTS3_SEGCURSOR_ALL,
       pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
   );
   if( rc==SQLITE_OK ){
@@ -120113,24 +148143,37 @@ static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){
 */
 static int fts3auxColumnMethod(
   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
-  sqlite3_context *pContext,      /* Context for sqlite3_result_xxx() calls */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
   int iCol                        /* Index of column to read value from */
 ){
   Fts3auxCursor *p = (Fts3auxCursor *)pCursor;
 
   assert( p->isEof==0 );
-  if( iCol==0 ){        /* Column "term" */
-    sqlite3_result_text(pContext, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
-  }else if( iCol==1 ){  /* Column "col" */
-    if( p->iCol ){
-      sqlite3_result_int(pContext, p->iCol-1);
-    }else{
-      sqlite3_result_text(pContext, "*", -1, SQLITE_STATIC);
-    }
-  }else if( iCol==2 ){  /* Column "documents" */
-    sqlite3_result_int64(pContext, p->aStat[p->iCol].nDoc);
-  }else{                /* Column "occurrences" */
-    sqlite3_result_int64(pContext, p->aStat[p->iCol].nOcc);
+  switch( iCol ){
+    case 0: /* term */
+      sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
+      break;
+
+    case 1: /* col */
+      if( p->iCol ){
+        sqlite3_result_int(pCtx, p->iCol-1);
+      }else{
+        sqlite3_result_text(pCtx, "*", -1, SQLITE_STATIC);
+      }
+      break;
+
+    case 2: /* documents */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nDoc);
+      break;
+
+    case 3: /* occurrences */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nOcc);
+      break;
+
+    default: /* languageid */
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, p->iLangid);
+      break;
   }
 
   return SQLITE_OK;
@@ -120205,6 +148248,7 @@ SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db){
 ** syntax is relatively simple, the whole tokenizer/parser system is
 ** hand-coded. 
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /*
@@ -120281,6 +148325,7 @@ SQLITE_API int sqlite3_fts3_enable_parentheses = 0;
 typedef struct ParseContext ParseContext;
 struct ParseContext {
   sqlite3_tokenizer *pTokenizer;      /* Tokenizer module */
+  int iLangid;                        /* Language id used with tokenizer */
   const char **azCol;                 /* Array of column names for fts3 table */
   int bFts4;                          /* True to allow FTS4-only syntax */
   int nCol;                           /* Number of entries in azCol[] */
@@ -120294,7 +148339,7 @@ struct ParseContext {
 ** This function is equivalent to the standard isspace() function. 
 **
 ** The standard isspace() can be awkward to use safely, because although it
-** is defined to accept an argument of type int, its behaviour when passed
+** is defined to accept an argument of type int, its behavior when passed
 ** an integer that falls outside of the range of the unsigned char type
 ** is undefined (and sometimes, "undefined" means segfault). This wrapper
 ** is defined to accept an argument of type char, and always returns 0 for
@@ -120316,6 +148361,38 @@ static void *fts3MallocZero(int nByte){
   return pRet;
 }
 
+SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(
+  sqlite3_tokenizer *pTokenizer,
+  int iLangid,
+  const char *z,
+  int n,
+  sqlite3_tokenizer_cursor **ppCsr
+){
+  sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
+  sqlite3_tokenizer_cursor *pCsr = 0;
+  int rc;
+
+  rc = pModule->xOpen(pTokenizer, z, n, &pCsr);
+  assert( rc==SQLITE_OK || pCsr==0 );
+  if( rc==SQLITE_OK ){
+    pCsr->pTokenizer = pTokenizer;
+    if( pModule->iVersion>=1 ){
+      rc = pModule->xLanguageid(pCsr, iLangid);
+      if( rc!=SQLITE_OK ){
+        pModule->xClose(pCsr);
+        pCsr = 0;
+      }
+    }
+  }
+  *ppCsr = pCsr;
+  return rc;
+}
+
+/*
+** Function getNextNode(), which is called by fts3ExprParse(), may itself
+** call fts3ExprParse(). So this forward declaration is required.
+*/
+static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);
 
 /*
 ** Extract the next token from buffer z (length n) using the tokenizer
@@ -120341,17 +148418,22 @@ static int getNextToken(
   int rc;
   sqlite3_tokenizer_cursor *pCursor;
   Fts3Expr *pRet = 0;
-  int nConsumed = 0;
+  int i = 0;
 
-  rc = pModule->xOpen(pTokenizer, z, n, &pCursor);
+  /* Set variable i to the maximum number of bytes of input to tokenize. */
+  for(i=0; i<n; i++){
+    if( sqlite3_fts3_enable_parentheses && (z[i]=='(' || z[i]==')') ) break;
+    if( z[i]=='"' ) break;
+  }
+
+  *pnConsumed = i;
+  rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, i, &pCursor);
   if( rc==SQLITE_OK ){
     const char *zToken;
-    int nToken, iStart, iEnd, iPosition;
+    int nToken = 0, iStart = 0, iEnd = 0, iPosition = 0;
     int nByte;                               /* total space to allocate */
 
-    pCursor->pTokenizer = pTokenizer;
     rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);
-
     if( rc==SQLITE_OK ){
       nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;
       pRet = (Fts3Expr *)fts3MallocZero(nByte);
@@ -120386,13 +148468,14 @@ static int getNextToken(
         }
 
       }
-      nConsumed = iEnd;
+      *pnConsumed = iEnd;
+    }else if( i && rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
     }
 
     pModule->xClose(pCursor);
   }
   
-  *pnConsumed = nConsumed;
   *ppExpr = pRet;
   return rc;
 }
@@ -120457,13 +148540,13 @@ static int getNextString(
   ** appends buffer zTemp to buffer p, and fills in the Fts3Expr and Fts3Phrase
   ** structures.
   */
-  rc = pModule->xOpen(pTokenizer, zInput, nInput, &pCursor);
+  rc = sqlite3Fts3OpenTokenizer(
+      pTokenizer, pParse->iLangid, zInput, nInput, &pCursor);
   if( rc==SQLITE_OK ){
     int ii;
-    pCursor->pTokenizer = pTokenizer;
     for(ii=0; rc==SQLITE_OK; ii++){
       const char *zByte;
-      int nByte, iBegin, iEnd, iPos;
+      int nByte = 0, iBegin = 0, iEnd = 0, iPos = 0;
       rc = pModule->xNext(pCursor, &zByte, &nByte, &iBegin, &iEnd, &iPos);
       if( rc==SQLITE_OK ){
         Fts3PhraseToken *pToken;
@@ -120533,12 +148616,6 @@ no_mem:
 }
 
 /*
-** Function getNextNode(), which is called by fts3ExprParse(), may itself
-** call fts3ExprParse(). So this forward declaration is required.
-*/
-static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);
-
-/*
 ** The output variable *ppExpr is populated with an allocated Fts3Expr 
 ** structure, or set to 0 if the end of the input buffer is reached.
 **
@@ -120634,27 +148711,6 @@ static int getNextNode(
     }
   }
 
-  /* Check for an open bracket. */
-  if( sqlite3_fts3_enable_parentheses ){
-    if( *zInput=='(' ){
-      int nConsumed;
-      pParse->nNest++;
-      rc = fts3ExprParse(pParse, &zInput[1], nInput-1, ppExpr, &nConsumed);
-      if( rc==SQLITE_OK && !*ppExpr ){
-        rc = SQLITE_DONE;
-      }
-      *pnConsumed = (int)((zInput - z) + 1 + nConsumed);
-      return rc;
-    }
-  
-    /* Check for a close bracket. */
-    if( *zInput==')' ){
-      pParse->nNest--;
-      *pnConsumed = (int)((zInput - z) + 1);
-      return SQLITE_DONE;
-    }
-  }
-
   /* See if we are dealing with a quoted phrase. If this is the case, then
   ** search for the closing quote and pass the whole string to getNextString()
   ** for processing. This is easy to do, as fts3 has no syntax for escaping
@@ -120669,6 +148725,21 @@ static int getNextNode(
     return getNextString(pParse, &zInput[1], ii-1, ppExpr);
   }
 
+  if( sqlite3_fts3_enable_parentheses ){
+    if( *zInput=='(' ){
+      int nConsumed = 0;
+      pParse->nNest++;
+      rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);
+      if( rc==SQLITE_OK && !*ppExpr ){ rc = SQLITE_DONE; }
+      *pnConsumed = (int)(zInput - z) + 1 + nConsumed;
+      return rc;
+    }else if( *zInput==')' ){
+      pParse->nNest--;
+      *pnConsumed = (int)((zInput - z) + 1);
+      *ppExpr = 0;
+      return SQLITE_DONE;
+    }
+  }
 
   /* If control flows to this point, this must be a regular token, or 
   ** the end of the input. Read a regular token using the sqlite3_tokenizer
@@ -120787,94 +148858,100 @@ static int fts3ExprParse(
   while( rc==SQLITE_OK ){
     Fts3Expr *p = 0;
     int nByte = 0;
+
     rc = getNextNode(pParse, zIn, nIn, &p, &nByte);
+    assert( nByte>0 || (rc!=SQLITE_OK && p==0) );
     if( rc==SQLITE_OK ){
-      int isPhrase;
-
-      if( !sqlite3_fts3_enable_parentheses 
-       && p->eType==FTSQUERY_PHRASE && pParse->isNot 
-      ){
-        /* Create an implicit NOT operator. */
-        Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
-        if( !pNot ){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_NOMEM;
-          goto exprparse_out;
-        }
-        pNot->eType = FTSQUERY_NOT;
-        pNot->pRight = p;
-        if( pNotBranch ){
-          pNot->pLeft = pNotBranch;
-        }
-        pNotBranch = pNot;
-        p = pPrev;
-      }else{
-        int eType = p->eType;
-        isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);
+      if( p ){
+        int isPhrase;
 
-        /* The isRequirePhrase variable is set to true if a phrase or
-        ** an expression contained in parenthesis is required. If a
-        ** binary operator (AND, OR, NOT or NEAR) is encounted when
-        ** isRequirePhrase is set, this is a syntax error.
-        */
-        if( !isPhrase && isRequirePhrase ){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_ERROR;
-          goto exprparse_out;
-        }
-  
-        if( isPhrase && !isRequirePhrase ){
-          /* Insert an implicit AND operator. */
-          Fts3Expr *pAnd;
-          assert( pRet && pPrev );
-          pAnd = fts3MallocZero(sizeof(Fts3Expr));
-          if( !pAnd ){
+        if( !sqlite3_fts3_enable_parentheses 
+            && p->eType==FTSQUERY_PHRASE && pParse->isNot 
+        ){
+          /* Create an implicit NOT operator. */
+          Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
+          if( !pNot ){
             sqlite3Fts3ExprFree(p);
             rc = SQLITE_NOMEM;
             goto exprparse_out;
           }
-          pAnd->eType = FTSQUERY_AND;
-          insertBinaryOperator(&pRet, pPrev, pAnd);
-          pPrev = pAnd;
-        }
+          pNot->eType = FTSQUERY_NOT;
+          pNot->pRight = p;
+          p->pParent = pNot;
+          if( pNotBranch ){
+            pNot->pLeft = pNotBranch;
+            pNotBranch->pParent = pNot;
+          }
+          pNotBranch = pNot;
+          p = pPrev;
+        }else{
+          int eType = p->eType;
+          isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);
 
-        /* This test catches attempts to make either operand of a NEAR
-        ** operator something other than a phrase. For example, either of
-        ** the following:
-        **
-        **    (bracketed expression) NEAR phrase
-        **    phrase NEAR (bracketed expression)
-        **
-        ** Return an error in either case.
-        */
-        if( pPrev && (
+          /* The isRequirePhrase variable is set to true if a phrase or
+          ** an expression contained in parenthesis is required. If a
+          ** binary operator (AND, OR, NOT or NEAR) is encounted when
+          ** isRequirePhrase is set, this is a syntax error.
+          */
+          if( !isPhrase && isRequirePhrase ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase && !isRequirePhrase ){
+            /* Insert an implicit AND operator. */
+            Fts3Expr *pAnd;
+            assert( pRet && pPrev );
+            pAnd = fts3MallocZero(sizeof(Fts3Expr));
+            if( !pAnd ){
+              sqlite3Fts3ExprFree(p);
+              rc = SQLITE_NOMEM;
+              goto exprparse_out;
+            }
+            pAnd->eType = FTSQUERY_AND;
+            insertBinaryOperator(&pRet, pPrev, pAnd);
+            pPrev = pAnd;
+          }
+
+          /* This test catches attempts to make either operand of a NEAR
+           ** operator something other than a phrase. For example, either of
+           ** the following:
+           **
+           **    (bracketed expression) NEAR phrase
+           **    phrase NEAR (bracketed expression)
+           **
+           ** Return an error in either case.
+           */
+          if( pPrev && (
             (eType==FTSQUERY_NEAR && !isPhrase && pPrev->eType!=FTSQUERY_PHRASE)
          || (eType!=FTSQUERY_PHRASE && isPhrase && pPrev->eType==FTSQUERY_NEAR)
-        )){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_ERROR;
-          goto exprparse_out;
-        }
-  
-        if( isPhrase ){
-          if( pRet ){
-            assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );
-            pPrev->pRight = p;
-            p->pParent = pPrev;
+          )){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase ){
+            if( pRet ){
+              assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );
+              pPrev->pRight = p;
+              p->pParent = pPrev;
+            }else{
+              pRet = p;
+            }
           }else{
-            pRet = p;
+            insertBinaryOperator(&pRet, pPrev, p);
           }
-        }else{
-          insertBinaryOperator(&pRet, pPrev, p);
+          isRequirePhrase = !isPhrase;
         }
-        isRequirePhrase = !isPhrase;
+        pPrev = p;
       }
       assert( nByte>0 );
     }
     assert( rc!=SQLITE_OK || (nByte>0 && nByte<=nIn) );
     nIn -= nByte;
     zIn += nByte;
-    pPrev = p;
   }
 
   if( rc==SQLITE_DONE && pRet && isRequirePhrase ){
@@ -120892,6 +148969,7 @@ static int fts3ExprParse(
           pIter = pIter->pLeft;
         }
         pIter->pLeft = pRet;
+        pRet->pParent = pIter;
         pRet = pNotBranch;
       }
     }
@@ -120909,6 +148987,249 @@ exprparse_out:
 }
 
 /*
+** Return SQLITE_ERROR if the maximum depth of the expression tree passed 
+** as the only argument is more than nMaxDepth.
+*/
+static int fts3ExprCheckDepth(Fts3Expr *p, int nMaxDepth){
+  int rc = SQLITE_OK;
+  if( p ){
+    if( nMaxDepth<0 ){ 
+      rc = SQLITE_TOOBIG;
+    }else{
+      rc = fts3ExprCheckDepth(p->pLeft, nMaxDepth-1);
+      if( rc==SQLITE_OK ){
+        rc = fts3ExprCheckDepth(p->pRight, nMaxDepth-1);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** This function attempts to transform the expression tree at (*pp) to
+** an equivalent but more balanced form. The tree is modified in place.
+** If successful, SQLITE_OK is returned and (*pp) set to point to the 
+** new root expression node. 
+**
+** nMaxDepth is the maximum allowable depth of the balanced sub-tree.
+**
+** Otherwise, if an error occurs, an SQLite error code is returned and 
+** expression (*pp) freed.
+*/
+static int fts3ExprBalance(Fts3Expr **pp, int nMaxDepth){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts3Expr *pRoot = *pp;          /* Initial root node */
+  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
+  int eType = pRoot->eType;       /* Type of node in this tree */
+
+  if( nMaxDepth==0 ){
+    rc = SQLITE_ERROR;
+  }
+
+  if( rc==SQLITE_OK ){
+    if( (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
+      Fts3Expr **apLeaf;
+      apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
+      if( 0==apLeaf ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
+      }
+
+      if( rc==SQLITE_OK ){
+        int i;
+        Fts3Expr *p;
+
+        /* Set $p to point to the left-most leaf in the tree of eType nodes. */
+        for(p=pRoot; p->eType==eType; p=p->pLeft){
+          assert( p->pParent==0 || p->pParent->pLeft==p );
+          assert( p->pLeft && p->pRight );
+        }
+
+        /* This loop runs once for each leaf in the tree of eType nodes. */
+        while( 1 ){
+          int iLvl;
+          Fts3Expr *pParent = p->pParent;     /* Current parent of p */
+
+          assert( pParent==0 || pParent->pLeft==p );
+          p->pParent = 0;
+          if( pParent ){
+            pParent->pLeft = 0;
+          }else{
+            pRoot = 0;
+          }
+          rc = fts3ExprBalance(&p, nMaxDepth-1);
+          if( rc!=SQLITE_OK ) break;
+
+          for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){
+            if( apLeaf[iLvl]==0 ){
+              apLeaf[iLvl] = p;
+              p = 0;
+            }else{
+              assert( pFree );
+              pFree->pLeft = apLeaf[iLvl];
+              pFree->pRight = p;
+              pFree->pLeft->pParent = pFree;
+              pFree->pRight->pParent = pFree;
+
+              p = pFree;
+              pFree = pFree->pParent;
+              p->pParent = 0;
+              apLeaf[iLvl] = 0;
+            }
+          }
+          if( p ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_TOOBIG;
+            break;
+          }
+
+          /* If that was the last leaf node, break out of the loop */
+          if( pParent==0 ) break;
+
+          /* Set $p to point to the next leaf in the tree of eType nodes */
+          for(p=pParent->pRight; p->eType==eType; p=p->pLeft);
+
+          /* Remove pParent from the original tree. */
+          assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
+          pParent->pRight->pParent = pParent->pParent;
+          if( pParent->pParent ){
+            pParent->pParent->pLeft = pParent->pRight;
+          }else{
+            assert( pParent==pRoot );
+            pRoot = pParent->pRight;
+          }
+
+          /* Link pParent into the free node list. It will be used as an
+          ** internal node of the new tree.  */
+          pParent->pParent = pFree;
+          pFree = pParent;
+        }
+
+        if( rc==SQLITE_OK ){
+          p = 0;
+          for(i=0; i<nMaxDepth; i++){
+            if( apLeaf[i] ){
+              if( p==0 ){
+                p = apLeaf[i];
+                p->pParent = 0;
+              }else{
+                assert( pFree!=0 );
+                pFree->pRight = p;
+                pFree->pLeft = apLeaf[i];
+                pFree->pLeft->pParent = pFree;
+                pFree->pRight->pParent = pFree;
+
+                p = pFree;
+                pFree = pFree->pParent;
+                p->pParent = 0;
+              }
+            }
+          }
+          pRoot = p;
+        }else{
+          /* An error occurred. Delete the contents of the apLeaf[] array 
+          ** and pFree list. Everything else is cleaned up by the call to
+          ** sqlite3Fts3ExprFree(pRoot) below.  */
+          Fts3Expr *pDel;
+          for(i=0; i<nMaxDepth; i++){
+            sqlite3Fts3ExprFree(apLeaf[i]);
+          }
+          while( (pDel=pFree)!=0 ){
+            pFree = pDel->pParent;
+            sqlite3_free(pDel);
+          }
+        }
+
+        assert( pFree==0 );
+        sqlite3_free( apLeaf );
+      }
+    }else if( eType==FTSQUERY_NOT ){
+      Fts3Expr *pLeft = pRoot->pLeft;
+      Fts3Expr *pRight = pRoot->pRight;
+
+      pRoot->pLeft = 0;
+      pRoot->pRight = 0;
+      pLeft->pParent = 0;
+      pRight->pParent = 0;
+
+      rc = fts3ExprBalance(&pLeft, nMaxDepth-1);
+      if( rc==SQLITE_OK ){
+        rc = fts3ExprBalance(&pRight, nMaxDepth-1);
+      }
+
+      if( rc!=SQLITE_OK ){
+        sqlite3Fts3ExprFree(pRight);
+        sqlite3Fts3ExprFree(pLeft);
+      }else{
+        assert( pLeft && pRight );
+        pRoot->pLeft = pLeft;
+        pLeft->pParent = pRoot;
+        pRoot->pRight = pRight;
+        pRight->pParent = pRoot;
+      }
+    }
+  }
+  
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts3ExprFree(pRoot);
+    pRoot = 0;
+  }
+  *pp = pRoot;
+  return rc;
+}
+
+/*
+** This function is similar to sqlite3Fts3ExprParse(), with the following
+** differences:
+**
+**   1. It does not do expression rebalancing.
+**   2. It does not check that the expression does not exceed the 
+**      maximum allowable depth.
+**   3. Even if it fails, *ppExpr may still be set to point to an 
+**      expression tree. It should be deleted using sqlite3Fts3ExprFree()
+**      in this case.
+*/
+static int fts3ExprParseUnbalanced(
+  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
+  int iLangid,                        /* Language id for tokenizer */
+  char **azCol,                       /* Array of column names for fts3 table */
+  int bFts4,                          /* True to allow FTS4-only syntax */
+  int nCol,                           /* Number of entries in azCol[] */
+  int iDefaultCol,                    /* Default column to query */
+  const char *z, int n,               /* Text of MATCH query */
+  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
+){
+  int nParsed;
+  int rc;
+  ParseContext sParse;
+
+  memset(&sParse, 0, sizeof(ParseContext));
+  sParse.pTokenizer = pTokenizer;
+  sParse.iLangid = iLangid;
+  sParse.azCol = (const char **)azCol;
+  sParse.nCol = nCol;
+  sParse.iDefaultCol = iDefaultCol;
+  sParse.bFts4 = bFts4;
+  if( z==0 ){
+    *ppExpr = 0;
+    return SQLITE_OK;
+  }
+  if( n<0 ){
+    n = (int)strlen(z);
+  }
+  rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);
+  assert( rc==SQLITE_OK || *ppExpr==0 );
+
+  /* Check for mismatched parenthesis */
+  if( rc==SQLITE_OK && sParse.nNest ){
+    rc = SQLITE_ERROR;
+  }
+  
+  return rc;
+}
+
+/*
 ** Parameters z and n contain a pointer to and length of a buffer containing
 ** an fts3 query expression, respectively. This function attempts to parse the
 ** query expression and create a tree of Fts3Expr structures representing the
@@ -120934,52 +149255,80 @@ exprparse_out:
 */
 SQLITE_PRIVATE int sqlite3Fts3ExprParse(
   sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
+  int iLangid,                        /* Language id for tokenizer */
   char **azCol,                       /* Array of column names for fts3 table */
   int bFts4,                          /* True to allow FTS4-only syntax */
   int nCol,                           /* Number of entries in azCol[] */
   int iDefaultCol,                    /* Default column to query */
   const char *z, int n,               /* Text of MATCH query */
-  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
+  Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
+  char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
 ){
-  int nParsed;
-  int rc;
-  ParseContext sParse;
-  sParse.pTokenizer = pTokenizer;
-  sParse.azCol = (const char **)azCol;
-  sParse.nCol = nCol;
-  sParse.iDefaultCol = iDefaultCol;
-  sParse.nNest = 0;
-  sParse.bFts4 = bFts4;
-  if( z==0 ){
-    *ppExpr = 0;
-    return SQLITE_OK;
-  }
-  if( n<0 ){
-    n = (int)strlen(z);
+  int rc = fts3ExprParseUnbalanced(
+      pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
+  );
+  
+  /* Rebalance the expression. And check that its depth does not exceed
+  ** SQLITE_FTS3_MAX_EXPR_DEPTH.  */
+  if( rc==SQLITE_OK && *ppExpr ){
+    rc = fts3ExprBalance(ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
+    if( rc==SQLITE_OK ){
+      rc = fts3ExprCheckDepth(*ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
+    }
   }
-  rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);
 
-  /* Check for mismatched parenthesis */
-  if( rc==SQLITE_OK && sParse.nNest ){
-    rc = SQLITE_ERROR;
+  if( rc!=SQLITE_OK ){
     sqlite3Fts3ExprFree(*ppExpr);
     *ppExpr = 0;
+    if( rc==SQLITE_TOOBIG ){
+      sqlite3Fts3ErrMsg(pzErr,
+          "FTS expression tree is too large (maximum depth %d)", 
+          SQLITE_FTS3_MAX_EXPR_DEPTH
+      );
+      rc = SQLITE_ERROR;
+    }else if( rc==SQLITE_ERROR ){
+      sqlite3Fts3ErrMsg(pzErr, "malformed MATCH expression: [%s]", z);
+    }
   }
 
   return rc;
 }
 
 /*
+** Free a single node of an expression tree.
+*/
+static void fts3FreeExprNode(Fts3Expr *p){
+  assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
+  sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
+  sqlite3_free(p->aMI);
+  sqlite3_free(p);
+}
+
+/*
 ** Free a parsed fts3 query expression allocated by sqlite3Fts3ExprParse().
+**
+** This function would be simpler if it recursively called itself. But
+** that would mean passing a sufficiently large expression to ExprParse()
+** could cause a stack overflow.
 */
-SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *p){
-  if( p ){
-    assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
-    sqlite3Fts3ExprFree(p->pLeft);
-    sqlite3Fts3ExprFree(p->pRight);
-    sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
-    sqlite3_free(p->aMI);
-    sqlite3_free(p);
+SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *pDel){
+  Fts3Expr *p;
+  assert( pDel==0 || pDel->pParent==0 );
+  for(p=pDel; p && (p->pLeft||p->pRight); p=(p->pLeft ? p->pLeft : p->pRight)){
+    assert( p->pParent==0 || p==p->pParent->pRight || p==p->pParent->pLeft );
+  }
+  while( p ){
+    Fts3Expr *pParent = p->pParent;
+    fts3FreeExprNode(p);
+    if( pParent && p==pParent->pLeft && pParent->pRight ){
+      p = pParent->pRight;
+      while( p && (p->pLeft || p->pRight) ){
+        assert( p==p->pParent->pRight || p==p->pParent->pLeft );
+        p = (p->pLeft ? p->pLeft : p->pRight);
+      }
+    }else{
+      p = pParent;
+    }
   }
 }
 
@@ -121031,6 +149380,9 @@ static int queryTestTokenizer(
 ** the returned expression text and then freed using sqlite3_free().
 */
 static char *exprToString(Fts3Expr *pExpr, char *zBuf){
+  if( pExpr==0 ){
+    return sqlite3_mprintf("");
+  }
   switch( pExpr->eType ){
     case FTSQUERY_PHRASE: {
       Fts3Phrase *pPhrase = pExpr->pPhrase;
@@ -121138,10 +149490,21 @@ static void fts3ExprTest(
     azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
   }
 
-  rc = sqlite3Fts3ExprParse(
-      pTokenizer, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
-  );
+  if( sqlite3_user_data(context) ){
+    char *zDummy = 0;
+    rc = sqlite3Fts3ExprParse(
+        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr, &zDummy
+    );
+    assert( rc==SQLITE_OK || pExpr==0 );
+    sqlite3_free(zDummy);
+  }else{
+    rc = fts3ExprParseUnbalanced(
+        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
+    );
+  }
+
   if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){
+    sqlite3Fts3ExprFree(pExpr);
     sqlite3_result_error(context, "Error parsing expression", -1);
   }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){
     sqlite3_result_error_nomem(context);
@@ -121164,9 +149527,15 @@ exprtest_out:
 ** with database connection db. 
 */
 SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
-  return sqlite3_create_function(
+  int rc = sqlite3_create_function(
       db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
   );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 
+        -1, SQLITE_UTF8, (void *)1, fts3ExprTest, 0, 0
+    );
+  }
+  return rc;
 }
 
 #endif
@@ -121199,12 +149568,14 @@ SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
 **     * The FTS3 module is being built into the core of
 **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <assert.h> */
 /* #include <stdlib.h> */
 /* #include <string.h> */
 
+/* #include "fts3_hash.h" */
 
 /*
 ** Malloc and Free functions
@@ -121270,13 +149641,13 @@ SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash *pH){
 */
 static int fts3StrHash(const void *pKey, int nKey){
   const char *z = (const char *)pKey;
-  int h = 0;
+  unsigned h = 0;
   if( nKey<=0 ) nKey = (int) strlen(z);
   while( nKey > 0  ){
     h = (h<<3) ^ h ^ *z++;
     nKey--;
   }
-  return h & 0x7fffffff;
+  return (int)(h & 0x7fffffff);
 }
 static int fts3StrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
   if( n1!=n2 ) return 1;
@@ -121582,6 +149953,7 @@ SQLITE_PRIVATE void *sqlite3Fts3HashInsert(
 **     * The FTS3 module is being built into the core of
 **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <assert.h> */
@@ -121589,6 +149961,7 @@ SQLITE_PRIVATE void *sqlite3Fts3HashInsert(
 /* #include <stdio.h> */
 /* #include <string.h> */
 
+/* #include "fts3_tokenizer.h" */
 
 /*
 ** Class derived from sqlite3_tokenizer
@@ -121598,7 +149971,7 @@ typedef struct porter_tokenizer {
 } porter_tokenizer;
 
 /*
-** Class derived from sqlit3_tokenizer_cursor
+** Class derived from sqlite3_tokenizer_cursor
 */
 typedef struct porter_tokenizer_cursor {
   sqlite3_tokenizer_cursor base;
@@ -121741,7 +150114,7 @@ static int isVowel(const char *z){
 ** by a consonant.
 **
 ** In this routine z[] is in reverse order.  So we are really looking
-** for an instance of of a consonant followed by a vowel.
+** for an instance of a consonant followed by a vowel.
 */
 static int m_gt_0(const char *z){
   while( isVowel(z) ){ z++; }
@@ -121961,12 +150334,14 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
   /* Step 2 */
   switch( z[1] ){
    case 'a':
-     stem(&z, "lanoita", "ate", m_gt_0) ||
-     stem(&z, "lanoit", "tion", m_gt_0);
+     if( !stem(&z, "lanoita", "ate", m_gt_0) ){
+       stem(&z, "lanoit", "tion", m_gt_0);
+     }
      break;
    case 'c':
-     stem(&z, "icne", "ence", m_gt_0) ||
-     stem(&z, "icna", "ance", m_gt_0);
+     if( !stem(&z, "icne", "ence", m_gt_0) ){
+       stem(&z, "icna", "ance", m_gt_0);
+     }
      break;
    case 'e':
      stem(&z, "rezi", "ize", m_gt_0);
@@ -121975,43 +150350,54 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
      stem(&z, "igol", "log", m_gt_0);
      break;
    case 'l':
-     stem(&z, "ilb", "ble", m_gt_0) ||
-     stem(&z, "illa", "al", m_gt_0) ||
-     stem(&z, "iltne", "ent", m_gt_0) ||
-     stem(&z, "ile", "e", m_gt_0) ||
-     stem(&z, "ilsuo", "ous", m_gt_0);
+     if( !stem(&z, "ilb", "ble", m_gt_0) 
+      && !stem(&z, "illa", "al", m_gt_0)
+      && !stem(&z, "iltne", "ent", m_gt_0)
+      && !stem(&z, "ile", "e", m_gt_0)
+     ){
+       stem(&z, "ilsuo", "ous", m_gt_0);
+     }
      break;
    case 'o':
-     stem(&z, "noitazi", "ize", m_gt_0) ||
-     stem(&z, "noita", "ate", m_gt_0) ||
-     stem(&z, "rota", "ate", m_gt_0);
+     if( !stem(&z, "noitazi", "ize", m_gt_0)
+      && !stem(&z, "noita", "ate", m_gt_0)
+     ){
+       stem(&z, "rota", "ate", m_gt_0);
+     }
      break;
    case 's':
-     stem(&z, "msila", "al", m_gt_0) ||
-     stem(&z, "ssenevi", "ive", m_gt_0) ||
-     stem(&z, "ssenluf", "ful", m_gt_0) ||
-     stem(&z, "ssensuo", "ous", m_gt_0);
+     if( !stem(&z, "msila", "al", m_gt_0)
+      && !stem(&z, "ssenevi", "ive", m_gt_0)
+      && !stem(&z, "ssenluf", "ful", m_gt_0)
+     ){
+       stem(&z, "ssensuo", "ous", m_gt_0);
+     }
      break;
    case 't':
-     stem(&z, "itila", "al", m_gt_0) ||
-     stem(&z, "itivi", "ive", m_gt_0) ||
-     stem(&z, "itilib", "ble", m_gt_0);
+     if( !stem(&z, "itila", "al", m_gt_0)
+      && !stem(&z, "itivi", "ive", m_gt_0)
+     ){
+       stem(&z, "itilib", "ble", m_gt_0);
+     }
      break;
   }
 
   /* Step 3 */
   switch( z[0] ){
    case 'e':
-     stem(&z, "etaci", "ic", m_gt_0) ||
-     stem(&z, "evita", "", m_gt_0)   ||
-     stem(&z, "ezila", "al", m_gt_0);
+     if( !stem(&z, "etaci", "ic", m_gt_0)
+      && !stem(&z, "evita", "", m_gt_0)
+     ){
+       stem(&z, "ezila", "al", m_gt_0);
+     }
      break;
    case 'i':
      stem(&z, "itici", "ic", m_gt_0);
      break;
    case 'l':
-     stem(&z, "laci", "ic", m_gt_0) ||
-     stem(&z, "luf", "", m_gt_0);
+     if( !stem(&z, "laci", "ic", m_gt_0) ){
+       stem(&z, "luf", "", m_gt_0);
+     }
      break;
    case 's':
      stem(&z, "ssen", "", m_gt_0);
@@ -122052,9 +150438,11 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
            z += 3;
          }
        }else if( z[2]=='e' ){
-         stem(&z, "tneme", "", m_gt_1) ||
-         stem(&z, "tnem", "", m_gt_1) ||
-         stem(&z, "tne", "", m_gt_1);
+         if( !stem(&z, "tneme", "", m_gt_1)
+          && !stem(&z, "tnem", "", m_gt_1)
+         ){
+           stem(&z, "tne", "", m_gt_1);
+         }
        }
      }
      break;
@@ -122073,8 +150461,9 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
      }
      break;
    case 't':
-     stem(&z, "eta", "", m_gt_1) ||
-     stem(&z, "iti", "", m_gt_1);
+     if( !stem(&z, "eta", "", m_gt_1) ){
+       stem(&z, "iti", "", m_gt_1);
+     }
      break;
    case 'u':
      if( z[0]=='s' && z[2]=='o' && m_gt_1(z+3) ){
@@ -122188,6 +150577,7 @@ static const sqlite3_tokenizer_module porterTokenizerModule = {
   porterOpen,
   porterClose,
   porterNext,
+  0
 };
 
 /*
@@ -122229,12 +150619,25 @@ SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(
 **     * The FTS3 module is being built into the core of
 **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <assert.h> */
 /* #include <string.h> */
 
 /*
+** Return true if the two-argument version of fts3_tokenizer()
+** has been activated via a prior call to sqlite3_db_config(db,
+** SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);
+*/
+static int fts3TokenizerEnabled(sqlite3_context *context){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int isEnabled = 0;
+  sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled);
+  return isEnabled;
+}
+
+/*
 ** Implementation of the SQL scalar function for accessing the underlying 
 ** hash table. This function may be called as follows:
 **
@@ -122254,7 +150657,7 @@ SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(
 ** is a blob containing the pointer stored as the hash data corresponding
 ** to string <key-name> (after the hash-table is updated, if applicable).
 */
-static void scalarFunc(
+static void fts3TokenizerFunc(
   sqlite3_context *context,
   int argc,
   sqlite3_value **argv
@@ -122272,20 +150675,26 @@ static void scalarFunc(
   nName = sqlite3_value_bytes(argv[0])+1;
 
   if( argc==2 ){
-    void *pOld;
-    int n = sqlite3_value_bytes(argv[1]);
-    if( n!=sizeof(pPtr) ){
-      sqlite3_result_error(context, "argument type mismatch", -1);
-      return;
-    }
-    pPtr = *(void **)sqlite3_value_blob(argv[1]);
-    pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
-    if( pOld==pPtr ){
-      sqlite3_result_error(context, "out of memory", -1);
+    if( fts3TokenizerEnabled(context) ){
+      void *pOld;
+      int n = sqlite3_value_bytes(argv[1]);
+      if( zName==0 || n!=sizeof(pPtr) ){
+        sqlite3_result_error(context, "argument type mismatch", -1);
+        return;
+      }
+      pPtr = *(void **)sqlite3_value_blob(argv[1]);
+      pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
+      if( pOld==pPtr ){
+        sqlite3_result_error(context, "out of memory", -1);
+      }
+    }else{
+      sqlite3_result_error(context, "fts3tokenize disabled", -1);
       return;
     }
   }else{
-    pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
+    if( zName ){
+      pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
+    }
     if( !pPtr ){
       char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
       sqlite3_result_error(context, zErr, -1);
@@ -122293,7 +150702,6 @@ static void scalarFunc(
       return;
     }
   }
-
   sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
 }
 
@@ -122366,12 +150774,16 @@ SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(
   zEnd = &zCopy[strlen(zCopy)];
 
   z = (char *)sqlite3Fts3NextToken(zCopy, &n);
+  if( z==0 ){
+    assert( n==0 );
+    z = zCopy;
+  }
   z[n] = '\0';
   sqlite3Fts3Dequote(z);
 
   m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);
   if( !m ){
-    *pzErr = sqlite3_mprintf("unknown tokenizer: %s", z);
+    sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", z);
     rc = SQLITE_ERROR;
   }else{
     char const **aArg = 0;
@@ -122394,7 +150806,7 @@ SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(
     rc = m->xCreate(iArg, aArg, ppTok);
     assert( rc!=SQLITE_OK || *ppTok );
     if( rc!=SQLITE_OK ){
-      *pzErr = sqlite3_mprintf("unknown tokenizer");
+      sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer");
     }else{
       (*ppTok)->pModule = m; 
     }
@@ -122408,16 +150820,19 @@ SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(
 
 #ifdef SQLITE_TEST
 
-/* #include <tcl.h> */
+#if defined(INCLUDE_SQLITE_TCL_H)
+#  include "sqlite_tcl.h"
+#else
+#  include "tcl.h"
+#endif
 /* #include <string.h> */
 
 /*
 ** Implementation of a special SQL scalar function for testing tokenizers 
 ** designed to be used in concert with the Tcl testing framework. This
-** function must be called with two arguments:
+** function must be called with two or more arguments:
 **
-**   SELECT <function-name>(<key-name>, <input-string>);
-**   SELECT <function-name>(<key-name>, <pointer>);
+**   SELECT <function-name>(<key-name>, ..., <input-string>);
 **
 ** where <function-name> is the name passed as the second argument
 ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer')
@@ -122454,50 +150869,53 @@ static void testFunc(
   const char *zInput;
   int nInput;
 
-  const char *zArg = 0;
+  const char *azArg[64];
 
   const char *zToken;
-  int nToken;
-  int iStart;
-  int iEnd;
-  int iPos;
+  int nToken = 0;
+  int iStart = 0;
+  int iEnd = 0;
+  int iPos = 0;
+  int i;
 
   Tcl_Obj *pRet;
 
-  assert( argc==2 || argc==3 );
+  if( argc<2 ){
+    sqlite3_result_error(context, "insufficient arguments", -1);
+    return;
+  }
 
   nName = sqlite3_value_bytes(argv[0]);
   zName = (const char *)sqlite3_value_text(argv[0]);
   nInput = sqlite3_value_bytes(argv[argc-1]);
   zInput = (const char *)sqlite3_value_text(argv[argc-1]);
 
-  if( argc==3 ){
-    zArg = (const char *)sqlite3_value_text(argv[1]);
-  }
-
   pHash = (Fts3Hash *)sqlite3_user_data(context);
   p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
 
   if( !p ){
-    char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
-    sqlite3_result_error(context, zErr, -1);
-    sqlite3_free(zErr);
+    char *zErr2 = sqlite3_mprintf("unknown tokenizer: %s", zName);
+    sqlite3_result_error(context, zErr2, -1);
+    sqlite3_free(zErr2);
     return;
   }
 
   pRet = Tcl_NewObj();
   Tcl_IncrRefCount(pRet);
 
-  if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){
+  for(i=1; i<argc-1; i++){
+    azArg[i-1] = (const char *)sqlite3_value_text(argv[i]);
+  }
+
+  if( SQLITE_OK!=p->xCreate(argc-2, azArg, &pTokenizer) ){
     zErr = "error in xCreate()";
     goto finish;
   }
   pTokenizer->pModule = p;
-  if( SQLITE_OK!=p->xOpen(pTokenizer, zInput, nInput, &pCsr) ){
+  if( sqlite3Fts3OpenTokenizer(pTokenizer, 0, zInput, nInput, &pCsr) ){
     zErr = "error in xOpen()";
     goto finish;
   }
-  pCsr->pTokenizer = pTokenizer;
 
   while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){
     Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos));
@@ -122547,6 +150965,7 @@ int registerTokenizer(
   return sqlite3_finalize(pStmt);
 }
 
+
 static
 int queryTokenizer(
   sqlite3 *db, 
@@ -122617,11 +151036,13 @@ static void intTestFunc(
   assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );
 
   /* Test the storage function */
-  rc = registerTokenizer(db, "nosuchtokenizer", p1);
-  assert( rc==SQLITE_OK );
-  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
-  assert( rc==SQLITE_OK );
-  assert( p2==p1 );
+  if( fts3TokenizerEnabled(context) ){
+    rc = registerTokenizer(db, "nosuchtokenizer", p1);
+    assert( rc==SQLITE_OK );
+    rc = queryTokenizer(db, "nosuchtokenizer", &p2);
+    assert( rc==SQLITE_OK );
+    assert( p2==p1 );
+  }
 
   sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
 }
@@ -122631,13 +151052,13 @@ static void intTestFunc(
 /*
 ** Set up SQL objects in database db used to access the contents of
 ** the hash table pointed to by argument pHash. The hash table must
-** been initialised to use string keys, and to take a private copy 
+** been initialized to use string keys, and to take a private copy 
 ** of the key when a value is inserted. i.e. by a call similar to:
 **
 **    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
 **
 ** This function adds a scalar function (see header comment above
-** scalarFunc() in this file for details) and, if ENABLE_TABLE is
+** fts3TokenizerFunc() in this file for details) and, if ENABLE_TABLE is
 ** defined at compilation time, a temporary virtual table (see header 
 ** comment above struct HashTableVtab) to the database schema. Both 
 ** provide read/write access to the contents of *pHash.
@@ -122666,17 +151087,14 @@ SQLITE_PRIVATE int sqlite3Fts3InitHashTable(
 #endif
 
   if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0);
+    rc = sqlite3_create_function(db, zName, 1, any, p, fts3TokenizerFunc, 0, 0);
   }
   if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0);
+    rc = sqlite3_create_function(db, zName, 2, any, p, fts3TokenizerFunc, 0, 0);
   }
 #ifdef SQLITE_TEST
   if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0);
-  }
-  if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0);
+    rc = sqlite3_create_function(db, zTest, -1, any, p, testFunc, 0, 0);
   }
   if( SQLITE_OK==rc ){
     rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0);
@@ -122719,6 +151137,7 @@ SQLITE_PRIVATE int sqlite3Fts3InitHashTable(
 **     * The FTS3 module is being built into the core of
 **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <assert.h> */
@@ -122726,6 +151145,7 @@ SQLITE_PRIVATE int sqlite3Fts3InitHashTable(
 /* #include <stdio.h> */
 /* #include <string.h> */
 
+/* #include "fts3_tokenizer.h" */
 
 typedef struct simple_tokenizer {
   sqlite3_tokenizer base;
@@ -122913,6 +151333,7 @@ static const sqlite3_tokenizer_module simpleTokenizerModule = {
   simpleOpen,
   simpleClose,
   simpleNext,
+  0,
 };
 
 /*
@@ -122928,6 +151349,463 @@ SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
 
 /************** End of fts3_tokenizer1.c *************************************/
+/************** Begin file fts3_tokenize_vtab.c ******************************/
+/*
+** 2013 Apr 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code for the "fts3tokenize" virtual table module.
+** An fts3tokenize virtual table is created as follows:
+**
+**   CREATE VIRTUAL TABLE <tbl> USING fts3tokenize(
+**       <tokenizer-name>, <arg-1>, ...
+**   );
+**
+** The table created has the following schema:
+**
+**   CREATE TABLE <tbl>(input, token, start, end, position)
+**
+** When queried, the query must include a WHERE clause of type:
+**
+**   input = <string>
+**
+** The virtual table module tokenizes this <string>, using the FTS3 
+** tokenizer specified by the arguments to the CREATE VIRTUAL TABLE 
+** statement and returns one row for each token in the result. With
+** fields set as follows:
+**
+**   input:   Always set to a copy of <string>
+**   token:   A token from the input.
+**   start:   Byte offset of the token within the input <string>.
+**   end:     Byte offset of the byte immediately following the end of the
+**            token within the input string.
+**   pos:     Token offset of token within input.
+**
+*/
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include <string.h> */
+/* #include <assert.h> */
+
+typedef struct Fts3tokTable Fts3tokTable;
+typedef struct Fts3tokCursor Fts3tokCursor;
+
+/*
+** Virtual table structure.
+*/
+struct Fts3tokTable {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  const sqlite3_tokenizer_module *pMod;
+  sqlite3_tokenizer *pTok;
+};
+
+/*
+** Virtual table cursor structure.
+*/
+struct Fts3tokCursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  char *zInput;                   /* Input string */
+  sqlite3_tokenizer_cursor *pCsr; /* Cursor to iterate through zInput */
+  int iRowid;                     /* Current 'rowid' value */
+  const char *zToken;             /* Current 'token' value */
+  int nToken;                     /* Size of zToken in bytes */
+  int iStart;                     /* Current 'start' value */
+  int iEnd;                       /* Current 'end' value */
+  int iPos;                       /* Current 'pos' value */
+};
+
+/*
+** Query FTS for the tokenizer implementation named zName.
+*/
+static int fts3tokQueryTokenizer(
+  Fts3Hash *pHash,
+  const char *zName,
+  const sqlite3_tokenizer_module **pp,
+  char **pzErr
+){
+  sqlite3_tokenizer_module *p;
+  int nName = (int)strlen(zName);
+
+  p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
+  if( !p ){
+    sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", zName);
+    return SQLITE_ERROR;
+  }
+
+  *pp = p;
+  return SQLITE_OK;
+}
+
+/*
+** The second argument, argv[], is an array of pointers to nul-terminated
+** strings. This function makes a copy of the array and strings into a 
+** single block of memory. It then dequotes any of the strings that appear
+** to be quoted.
+**
+** If successful, output parameter *pazDequote is set to point at the
+** array of dequoted strings and SQLITE_OK is returned. The caller is
+** responsible for eventually calling sqlite3_free() to free the array
+** in this case. Or, if an error occurs, an SQLite error code is returned.
+** The final value of *pazDequote is undefined in this case.
+*/
+static int fts3tokDequoteArray(
+  int argc,                       /* Number of elements in argv[] */
+  const char * const *argv,       /* Input array */
+  char ***pazDequote              /* Output array */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( argc==0 ){
+    *pazDequote = 0;
+  }else{
+    int i;
+    int nByte = 0;
+    char **azDequote;
+
+    for(i=0; i<argc; i++){
+      nByte += (int)(strlen(argv[i]) + 1);
+    }
+
+    *pazDequote = azDequote = sqlite3_malloc(sizeof(char *)*argc + nByte);
+    if( azDequote==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      char *pSpace = (char *)&azDequote[argc];
+      for(i=0; i<argc; i++){
+        int n = (int)strlen(argv[i]);
+        azDequote[i] = pSpace;
+        memcpy(pSpace, argv[i], n+1);
+        sqlite3Fts3Dequote(pSpace);
+        pSpace += (n+1);
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Schema of the tokenizer table.
+*/
+#define FTS3_TOK_SCHEMA "CREATE TABLE x(input, token, start, end, position)"
+
+/*
+** This function does all the work for both the xConnect and xCreate methods.
+** These tables have no persistent representation of their own, so xConnect
+** and xCreate are identical operations.
+**
+**   argv[0]: module name
+**   argv[1]: database name 
+**   argv[2]: table name
+**   argv[3]: first argument (tokenizer name)
+*/
+static int fts3tokConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pHash,                    /* Hash table of tokenizers */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  Fts3tokTable *pTab = 0;
+  const sqlite3_tokenizer_module *pMod = 0;
+  sqlite3_tokenizer *pTok = 0;
+  int rc;
+  char **azDequote = 0;
+  int nDequote;
+
+  rc = sqlite3_declare_vtab(db, FTS3_TOK_SCHEMA);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nDequote = argc-3;
+  rc = fts3tokDequoteArray(nDequote, &argv[3], &azDequote);
+
+  if( rc==SQLITE_OK ){
+    const char *zModule;
+    if( nDequote<1 ){
+      zModule = "simple";
+    }else{
+      zModule = azDequote[0];
+    }
+    rc = fts3tokQueryTokenizer((Fts3Hash*)pHash, zModule, &pMod, pzErr);
+  }
+
+  assert( (rc==SQLITE_OK)==(pMod!=0) );
+  if( rc==SQLITE_OK ){
+    const char * const *azArg = (const char * const *)&azDequote[1];
+    rc = pMod->xCreate((nDequote>1 ? nDequote-1 : 0), azArg, &pTok);
+  }
+
+  if( rc==SQLITE_OK ){
+    pTab = (Fts3tokTable *)sqlite3_malloc(sizeof(Fts3tokTable));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    memset(pTab, 0, sizeof(Fts3tokTable));
+    pTab->pMod = pMod;
+    pTab->pTok = pTok;
+    *ppVtab = &pTab->base;
+  }else{
+    if( pTok ){
+      pMod->xDestroy(pTok);
+    }
+  }
+
+  sqlite3_free(azDequote);
+  return rc;
+}
+
+/*
+** This function does the work for both the xDisconnect and xDestroy methods.
+** These tables have no persistent representation of their own, so xDisconnect
+** and xDestroy are identical operations.
+*/
+static int fts3tokDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts3tokTable *pTab = (Fts3tokTable *)pVtab;
+
+  pTab->pMod->xDestroy(pTab->pTok);
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex - Analyze a WHERE and ORDER BY clause.
+*/
+static int fts3tokBestIndexMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_index_info *pInfo
+){
+  int i;
+  UNUSED_PARAMETER(pVTab);
+
+  for(i=0; i<pInfo->nConstraint; i++){
+    if( pInfo->aConstraint[i].usable 
+     && pInfo->aConstraint[i].iColumn==0 
+     && pInfo->aConstraint[i].op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
+      pInfo->idxNum = 1;
+      pInfo->aConstraintUsage[i].argvIndex = 1;
+      pInfo->aConstraintUsage[i].omit = 1;
+      pInfo->estimatedCost = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  pInfo->idxNum = 0;
+  assert( pInfo->estimatedCost>1000000.0 );
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen - Open a cursor.
+*/
+static int fts3tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts3tokCursor *pCsr;
+  UNUSED_PARAMETER(pVTab);
+
+  pCsr = (Fts3tokCursor *)sqlite3_malloc(sizeof(Fts3tokCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(Fts3tokCursor));
+
+  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** Reset the tokenizer cursor passed as the only argument. As if it had
+** just been returned by fts3tokOpenMethod().
+*/
+static void fts3tokResetCursor(Fts3tokCursor *pCsr){
+  if( pCsr->pCsr ){
+    Fts3tokTable *pTab = (Fts3tokTable *)(pCsr->base.pVtab);
+    pTab->pMod->xClose(pCsr->pCsr);
+    pCsr->pCsr = 0;
+  }
+  sqlite3_free(pCsr->zInput);
+  pCsr->zInput = 0;
+  pCsr->zToken = 0;
+  pCsr->nToken = 0;
+  pCsr->iStart = 0;
+  pCsr->iEnd = 0;
+  pCsr->iPos = 0;
+  pCsr->iRowid = 0;
+}
+
+/*
+** xClose - Close a cursor.
+*/
+static int fts3tokCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  fts3tokResetCursor(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** xNext - Advance the cursor to the next row, if any.
+*/
+static int fts3tokNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  int rc;                         /* Return code */
+
+  pCsr->iRowid++;
+  rc = pTab->pMod->xNext(pCsr->pCsr,
+      &pCsr->zToken, &pCsr->nToken,
+      &pCsr->iStart, &pCsr->iEnd, &pCsr->iPos
+  );
+
+  if( rc!=SQLITE_OK ){
+    fts3tokResetCursor(pCsr);
+    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  }
+
+  return rc;
+}
+
+/*
+** xFilter - Initialize a cursor to point at the start of its data.
+*/
+static int fts3tokFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  int rc = SQLITE_ERROR;
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);
+  UNUSED_PARAMETER(idxStr);
+  UNUSED_PARAMETER(nVal);
+
+  fts3tokResetCursor(pCsr);
+  if( idxNum==1 ){
+    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
+    int nByte = sqlite3_value_bytes(apVal[0]);
+    pCsr->zInput = sqlite3_malloc(nByte+1);
+    if( pCsr->zInput==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memcpy(pCsr->zInput, zByte, nByte);
+      pCsr->zInput[nByte] = 0;
+      rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);
+      if( rc==SQLITE_OK ){
+        pCsr->pCsr->pTokenizer = pTab->pTok;
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ) return rc;
+  return fts3tokNextMethod(pCursor);
+}
+
+/*
+** xEof - Return true if the cursor is at EOF, or false otherwise.
+*/
+static int fts3tokEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  return (pCsr->zToken==0);
+}
+
+/*
+** xColumn - Return a column value.
+*/
+static int fts3tokColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+
+  /* CREATE TABLE x(input, token, start, end, position) */
+  switch( iCol ){
+    case 0:
+      sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);
+      break;
+    case 1:
+      sqlite3_result_text(pCtx, pCsr->zToken, pCsr->nToken, SQLITE_TRANSIENT);
+      break;
+    case 2:
+      sqlite3_result_int(pCtx, pCsr->iStart);
+      break;
+    case 3:
+      sqlite3_result_int(pCtx, pCsr->iEnd);
+      break;
+    default:
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, pCsr->iPos);
+      break;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** xRowid - Return the current rowid for the cursor.
+*/
+static int fts3tokRowidMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite_int64 *pRowid            /* OUT: Rowid value */
+){
+  Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;
+  *pRowid = (sqlite3_int64)pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** Register the fts3tok module with database connection db. Return SQLITE_OK
+** if successful or an error code if sqlite3_create_module() fails.
+*/
+SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3 *db, Fts3Hash *pHash){
+  static const sqlite3_module fts3tok_module = {
+     0,                           /* iVersion      */
+     fts3tokConnectMethod,        /* xCreate       */
+     fts3tokConnectMethod,        /* xConnect      */
+     fts3tokBestIndexMethod,      /* xBestIndex    */
+     fts3tokDisconnectMethod,     /* xDisconnect   */
+     fts3tokDisconnectMethod,     /* xDestroy      */
+     fts3tokOpenMethod,           /* xOpen         */
+     fts3tokCloseMethod,          /* xClose        */
+     fts3tokFilterMethod,         /* xFilter       */
+     fts3tokNextMethod,           /* xNext         */
+     fts3tokEofMethod,            /* xEof          */
+     fts3tokColumnMethod,         /* xColumn       */
+     fts3tokRowidMethod,          /* xRowid        */
+     0,                           /* xUpdate       */
+     0,                           /* xBegin        */
+     0,                           /* xSync         */
+     0,                           /* xCommit       */
+     0,                           /* xRollback     */
+     0,                           /* xFindFunction */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
+  };
+  int rc;                         /* Return code */
+
+  rc = sqlite3_create_module(db, "fts3tokenize", &fts3tok_module, (void*)pHash);
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+
+/************** End of fts3_tokenize_vtab.c **********************************/
 /************** Begin file fts3_write.c **************************************/
 /*
 ** 2009 Oct 23
@@ -122948,12 +151826,16 @@ SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(
 ** code in fts3.c.
 */
 
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <string.h> */
 /* #include <assert.h> */
 /* #include <stdlib.h> */
 
+
+#define FTS_MAX_APPENDABLE_HEIGHT 16
+
 /*
 ** When full-text index nodes are loaded from disk, the buffer that they
 ** are loaded into has the following number of bytes of padding at the end 
@@ -122993,6 +151875,29 @@ int test_fts3_node_chunk_threshold = (4*1024)*4;
 # define FTS3_NODE_CHUNK_THRESHOLD (FTS3_NODE_CHUNKSIZE*4)
 #endif
 
+/*
+** The two values that may be meaningfully bound to the :1 parameter in
+** statements SQL_REPLACE_STAT and SQL_SELECT_STAT.
+*/
+#define FTS_STAT_DOCTOTAL      0
+#define FTS_STAT_INCRMERGEHINT 1
+#define FTS_STAT_AUTOINCRMERGE 2
+
+/*
+** If FTS_LOG_MERGES is defined, call sqlite3_log() to report each automatic
+** and incremental merge operation that takes place. This is used for 
+** debugging FTS only, it should not usually be turned on in production
+** systems.
+*/
+#ifdef FTS3_LOG_MERGES
+static void fts3LogMerge(int nMerge, sqlite3_int64 iAbsLevel){
+  sqlite3_log(SQLITE_OK, "%d-way merge from level %d", nMerge, (int)iAbsLevel);
+}
+#else
+#define fts3LogMerge(x, y)
+#endif
+
+
 typedef struct PendingList PendingList;
 typedef struct SegmentNode SegmentNode;
 typedef struct SegmentWriter SegmentWriter;
@@ -123040,6 +151945,8 @@ struct Fts3DeferredToken {
 */
 struct Fts3SegReader {
   int iIdx;                       /* Index within level, or 0x7FFFFFFF for PT */
+  u8 bLookup;                     /* True for a lookup only */
+  u8 rootOnly;                    /* True for a root-only reader */
 
   sqlite3_int64 iStartBlock;      /* Rowid of first leaf block to traverse */
   sqlite3_int64 iLeafEndBlock;    /* Rowid of final leaf block to traverse */
@@ -123073,7 +151980,7 @@ struct Fts3SegReader {
 };
 
 #define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0)
-#define fts3SegReaderIsRootOnly(p) ((p)->aNode==(char *)&(p)[1])
+#define fts3SegReaderIsRootOnly(p) ((p)->rootOnly!=0)
 
 /*
 ** An instance of this structure is used to create a segment b-tree in the
@@ -123095,6 +152002,7 @@ struct SegmentWriter {
   int nSize;                      /* Size of allocation at aData */
   int nData;                      /* Bytes of data in aData */
   char *aData;                    /* Pointer to block from malloc() */
+  i64 nLeafData;                  /* Number of bytes of leaf data written */
 };
 
 /*
@@ -123153,13 +152061,26 @@ struct SegmentNode {
 #define SQL_DELETE_DOCSIZE            19
 #define SQL_REPLACE_DOCSIZE           20
 #define SQL_SELECT_DOCSIZE            21
-#define SQL_SELECT_DOCTOTAL           22
-#define SQL_REPLACE_DOCTOTAL          23
+#define SQL_SELECT_STAT               22
+#define SQL_REPLACE_STAT              23
 
 #define SQL_SELECT_ALL_PREFIX_LEVEL   24
 #define SQL_DELETE_ALL_TERMS_SEGDIR   25
-
 #define SQL_DELETE_SEGDIR_RANGE       26
+#define SQL_SELECT_ALL_LANGID         27
+#define SQL_FIND_MERGE_LEVEL          28
+#define SQL_MAX_LEAF_NODE_ESTIMATE    29
+#define SQL_DELETE_SEGDIR_ENTRY       30
+#define SQL_SHIFT_SEGDIR_ENTRY        31
+#define SQL_SELECT_SEGDIR             32
+#define SQL_CHOMP_SEGDIR              33
+#define SQL_SEGMENT_IS_APPENDABLE     34
+#define SQL_SELECT_INDEXES            35
+#define SQL_SELECT_MXLEVEL            36
+
+#define SQL_SELECT_LEVEL_RANGE2       37
+#define SQL_UPDATE_LEVEL_IDX          38
+#define SQL_UPDATE_LEVEL              39
 
 /*
 ** This function is used to obtain an SQLite prepared statement handle
@@ -123188,9 +152109,9 @@ static int fts3SqlStmt(
 /* 6  */  "DELETE FROM %Q.'%q_stat'",
 /* 7  */  "SELECT %s WHERE rowid=?",
 /* 8  */  "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1",
-/* 9  */  "INSERT INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)",
+/* 9  */  "REPLACE INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)",
 /* 10 */  "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)",
-/* 11 */  "INSERT INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)",
+/* 11 */  "REPLACE INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)",
 
           /* Return segments in order from oldest to newest.*/ 
 /* 12 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
@@ -123208,12 +152129,72 @@ static int fts3SqlStmt(
 /* 19 */  "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",
 /* 20 */  "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",
 /* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",
-/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=0",
-/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(0,?)",
+/* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=?",
+/* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(?,?)",
 /* 24 */  "",
 /* 25 */  "",
 
 /* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",
+/* 27 */ "SELECT ? UNION SELECT level / (1024 * ?) FROM %Q.'%q_segdir'",
+
+/* This statement is used to determine which level to read the input from
+** when performing an incremental merge. It returns the absolute level number
+** of the oldest level in the db that contains at least ? segments. Or,
+** if no level in the FTS index contains more than ? segments, the statement
+** returns zero rows.  */
+/* 28 */ "SELECT level, count(*) AS cnt FROM %Q.'%q_segdir' "
+         "  GROUP BY level HAVING cnt>=?"
+         "  ORDER BY (level %% 1024) ASC LIMIT 1",
+
+/* Estimate the upper limit on the number of leaf nodes in a new segment
+** created by merging the oldest :2 segments from absolute level :1. See 
+** function sqlite3Fts3Incrmerge() for details.  */
+/* 29 */ "SELECT 2 * total(1 + leaves_end_block - start_block) "
+         "  FROM %Q.'%q_segdir' WHERE level = ? AND idx < ?",
+
+/* SQL_DELETE_SEGDIR_ENTRY
+**   Delete the %_segdir entry on absolute level :1 with index :2.  */
+/* 30 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",
+
+/* SQL_SHIFT_SEGDIR_ENTRY
+**   Modify the idx value for the segment with idx=:3 on absolute level :2
+**   to :1.  */
+/* 31 */ "UPDATE %Q.'%q_segdir' SET idx = ? WHERE level=? AND idx=?",
+
+/* SQL_SELECT_SEGDIR
+**   Read a single entry from the %_segdir table. The entry from absolute 
+**   level :1 with index value :2.  */
+/* 32 */  "SELECT idx, start_block, leaves_end_block, end_block, root "
+            "FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",
+
+/* SQL_CHOMP_SEGDIR
+**   Update the start_block (:1) and root (:2) fields of the %_segdir
+**   entry located on absolute level :3 with index :4.  */
+/* 33 */  "UPDATE %Q.'%q_segdir' SET start_block = ?, root = ?"
+            "WHERE level = ? AND idx = ?",
+
+/* SQL_SEGMENT_IS_APPENDABLE
+**   Return a single row if the segment with end_block=? is appendable. Or
+**   no rows otherwise.  */
+/* 34 */  "SELECT 1 FROM %Q.'%q_segments' WHERE blockid=? AND block IS NULL",
+
+/* SQL_SELECT_INDEXES
+**   Return the list of valid segment indexes for absolute level ?  */
+/* 35 */  "SELECT idx FROM %Q.'%q_segdir' WHERE level=? ORDER BY 1 ASC",
+
+/* SQL_SELECT_MXLEVEL
+**   Return the largest relative level in the FTS index or indexes.  */
+/* 36 */  "SELECT max( level %% 1024 ) FROM %Q.'%q_segdir'",
+
+          /* Return segments in order from oldest to newest.*/ 
+/* 37 */  "SELECT level, idx, end_block "
+            "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ? "
+            "ORDER BY level DESC, idx ASC",
+
+          /* Update statements used while promoting segments */
+/* 38 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=-1,idx=? "
+            "WHERE level=? AND idx=?",
+/* 39 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=? WHERE level=-1"
 
   };
   int rc = SQLITE_OK;
@@ -123252,22 +152233,18 @@ static int fts3SqlStmt(
   return rc;
 }
 
+
 static int fts3SelectDocsize(
   Fts3Table *pTab,                /* FTS3 table handle */
-  int eStmt,                      /* Either SQL_SELECT_DOCSIZE or DOCTOTAL */
   sqlite3_int64 iDocid,           /* Docid to bind for SQL_SELECT_DOCSIZE */
   sqlite3_stmt **ppStmt           /* OUT: Statement handle */
 ){
   sqlite3_stmt *pStmt = 0;        /* Statement requested from fts3SqlStmt() */
   int rc;                         /* Return code */
 
-  assert( eStmt==SQL_SELECT_DOCSIZE || eStmt==SQL_SELECT_DOCTOTAL );
-
-  rc = fts3SqlStmt(pTab, eStmt, &pStmt, 0);
+  rc = fts3SqlStmt(pTab, SQL_SELECT_DOCSIZE, &pStmt, 0);
   if( rc==SQLITE_OK ){
-    if( eStmt==SQL_SELECT_DOCSIZE ){
-      sqlite3_bind_int64(pStmt, 1, iDocid);
-    }
+    sqlite3_bind_int64(pStmt, 1, iDocid);
     rc = sqlite3_step(pStmt);
     if( rc!=SQLITE_ROW || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){
       rc = sqlite3_reset(pStmt);
@@ -123286,7 +152263,21 @@ SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(
   Fts3Table *pTab,                /* Fts3 table handle */
   sqlite3_stmt **ppStmt           /* OUT: Statement handle */
 ){
-  return fts3SelectDocsize(pTab, SQL_SELECT_DOCTOTAL, 0, ppStmt);
+  sqlite3_stmt *pStmt = 0;
+  int rc;
+  rc = fts3SqlStmt(pTab, SQL_SELECT_STAT, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
+    if( sqlite3_step(pStmt)!=SQLITE_ROW
+     || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB
+    ){
+      rc = sqlite3_reset(pStmt);
+      if( rc==SQLITE_OK ) rc = FTS_CORRUPT_VTAB;
+      pStmt = 0;
+    }
+  }
+  *ppStmt = pStmt;
+  return rc;
 }
 
 SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(
@@ -123294,7 +152285,7 @@ SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(
   sqlite3_int64 iDocid,           /* Docid to read size data for */
   sqlite3_stmt **ppStmt           /* OUT: Statement handle */
 ){
-  return fts3SelectDocsize(pTab, SQL_SELECT_DOCSIZE, iDocid, ppStmt);
+  return fts3SelectDocsize(pTab, iDocid, ppStmt);
 }
 
 /*
@@ -123324,43 +152315,74 @@ static void fts3SqlExec(
 
 
 /*
-** This function ensures that the caller has obtained a shared-cache
-** table-lock on the %_content table. This is required before reading
-** data from the fts3 table. If this lock is not acquired first, then
-** the caller may end up holding read-locks on the %_segments and %_segdir
-** tables, but no read-lock on the %_content table. If this happens 
-** a second connection will be able to write to the fts3 table, but
-** attempting to commit those writes might return SQLITE_LOCKED or
-** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain 
-** write-locks on the %_segments and %_segdir ** tables). 
+** This function ensures that the caller has obtained an exclusive 
+** shared-cache table-lock on the %_segdir table. This is required before 
+** writing data to the fts3 table. If this lock is not acquired first, then
+** the caller may end up attempting to take this lock as part of committing
+** a transaction, causing SQLite to return SQLITE_LOCKED or 
+** LOCKED_SHAREDCACHEto a COMMIT command.
 **
-** We try to avoid this because if FTS3 returns any error when committing
-** a transaction, the whole transaction will be rolled back. And this is
-** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can
-** still happen if the user reads data directly from the %_segments or
-** %_segdir tables instead of going through FTS3 though.
-**
-** This reasoning does not apply to a content=xxx table.
+** It is best to avoid this because if FTS3 returns any error when 
+** committing a transaction, the whole transaction will be rolled back. 
+** And this is not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. 
+** It can still happen if the user locks the underlying tables directly 
+** instead of accessing them via FTS.
 */
-SQLITE_PRIVATE int sqlite3Fts3ReadLock(Fts3Table *p){
-  int rc;                         /* Return code */
-  sqlite3_stmt *pStmt;            /* Statement used to obtain lock */
-
-  if( p->zContentTbl==0 ){
-    rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0);
+static int fts3Writelock(Fts3Table *p){
+  int rc = SQLITE_OK;
+  
+  if( p->nPendingData==0 ){
+    sqlite3_stmt *pStmt;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pStmt, 0);
     if( rc==SQLITE_OK ){
       sqlite3_bind_null(pStmt, 1);
       sqlite3_step(pStmt);
       rc = sqlite3_reset(pStmt);
     }
-  }else{
-    rc = SQLITE_OK;
   }
 
   return rc;
 }
 
 /*
+** FTS maintains a separate indexes for each language-id (a 32-bit integer).
+** Within each language id, a separate index is maintained to store the
+** document terms, and each configured prefix size (configured the FTS 
+** "prefix=" option). And each index consists of multiple levels ("relative
+** levels").
+**
+** All three of these values (the language id, the specific index and the
+** level within the index) are encoded in 64-bit integer values stored
+** in the %_segdir table on disk. This function is used to convert three
+** separate component values into the single 64-bit integer value that
+** can be used to query the %_segdir table.
+**
+** Specifically, each language-id/index combination is allocated 1024 
+** 64-bit integer level values ("absolute levels"). The main terms index
+** for language-id 0 is allocate values 0-1023. The first prefix index
+** (if any) for language-id 0 is allocated values 1024-2047. And so on.
+** Language 1 indexes are allocated immediately following language 0.
+**
+** So, for a system with nPrefix prefix indexes configured, the block of
+** absolute levels that corresponds to language-id iLangid and index 
+** iIndex starts at absolute level ((iLangid * (nPrefix+1) + iIndex) * 1024).
+*/
+static sqlite3_int64 getAbsoluteLevel(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id */
+  int iIndex,                     /* Index in p->aIndex[] */
+  int iLevel                      /* Level of segments */
+){
+  sqlite3_int64 iBase;            /* First absolute level for iLangid/iIndex */
+  assert( iLangid>=0 );
+  assert( p->nIndex>0 );
+  assert( iIndex>=0 && iIndex<p->nIndex );
+
+  iBase = ((sqlite3_int64)iLangid * p->nIndex + iIndex) * FTS3_SEGDIR_MAXLEVEL;
+  return iBase + iLevel;
+}
+
+/*
 ** Set *ppStmt to a statement handle that may be used to iterate through
 ** all rows in the %_segdir table, from oldest to newest. If successful,
 ** return SQLITE_OK. If an error occurs while preparing the statement, 
@@ -123379,8 +152401,9 @@ SQLITE_PRIVATE int sqlite3Fts3ReadLock(Fts3Table *p){
 */
 SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(
   Fts3Table *p,                   /* FTS3 table */
+  int iLangid,                    /* Language being queried */
   int iIndex,                     /* Index for p->aIndex[] */
-  int iLevel,                     /* Level to select */
+  int iLevel,                     /* Level to select (relative level) */
   sqlite3_stmt **ppStmt           /* OUT: Compiled statement */
 ){
   int rc;
@@ -123394,14 +152417,16 @@ SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(
     /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */
     rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0);
     if( rc==SQLITE_OK ){ 
-      sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
-      sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL-1);
+      sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+      sqlite3_bind_int64(pStmt, 2, 
+          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+      );
     }
   }else{
     /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */
     rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
     if( rc==SQLITE_OK ){ 
-      sqlite3_bind_int(pStmt, 1, iLevel+iIndex*FTS3_SEGDIR_MAXLEVEL);
+      sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex,iLevel));
     }
   }
   *ppStmt = pStmt;
@@ -123567,18 +152592,19 @@ static int fts3PendingTermsAddOne(
 */
 static int fts3PendingTermsAdd(
   Fts3Table *p,                   /* Table into which text will be inserted */
+  int iLangid,                    /* Language id to use */
   const char *zText,              /* Text of document to be inserted */
   int iCol,                       /* Column into which text is being inserted */
-  u32 *pnWord                     /* OUT: Number of tokens inserted */
+  u32 *pnWord                     /* IN/OUT: Incr. by number tokens inserted */
 ){
   int rc;
-  int iStart;
-  int iEnd;
-  int iPos;
+  int iStart = 0;
+  int iEnd = 0;
+  int iPos = 0;
   int nWord = 0;
 
   char const *zToken;
-  int nToken;
+  int nToken = 0;
 
   sqlite3_tokenizer *pTokenizer = p->pTokenizer;
   sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;
@@ -123596,11 +152622,10 @@ static int fts3PendingTermsAdd(
     return SQLITE_OK;
   }
 
-  rc = pModule->xOpen(pTokenizer, zText, -1, &pCsr);
+  rc = sqlite3Fts3OpenTokenizer(pTokenizer, iLangid, zText, -1, &pCsr);
   if( rc!=SQLITE_OK ){
     return rc;
   }
-  pCsr->pTokenizer = pTokenizer;
 
   xNext = pModule->xNext;
   while( SQLITE_OK==rc
@@ -123634,7 +152659,7 @@ static int fts3PendingTermsAdd(
   }
 
   pModule->xClose(pCsr);
-  *pnWord = nWord;
+  *pnWord += nWord;
   return (rc==SQLITE_DONE ? SQLITE_OK : rc);
 }
 
@@ -123643,18 +152668,32 @@ static int fts3PendingTermsAdd(
 ** fts3PendingTermsAdd() are to add term/position-list pairs for the
 ** contents of the document with docid iDocid.
 */
-static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){
+static int fts3PendingTermsDocid(
+  Fts3Table *p,                   /* Full-text table handle */
+  int bDelete,                    /* True if this op is a delete */
+  int iLangid,                    /* Language id of row being written */
+  sqlite_int64 iDocid             /* Docid of row being written */
+){
+  assert( iLangid>=0 );
+  assert( bDelete==1 || bDelete==0 );
+
   /* TODO(shess) Explore whether partially flushing the buffer on
   ** forced-flush would provide better performance.  I suspect that if
   ** we ordered the doclists by size and flushed the largest until the
   ** buffer was half empty, that would let the less frequent terms
   ** generate longer doclists.
   */
-  if( iDocid<=p->iPrevDocid || p->nPendingData>p->nMaxPendingData ){
+  if( iDocid<p->iPrevDocid 
+   || (iDocid==p->iPrevDocid && p->bPrevDelete==0)
+   || p->iPrevLangid!=iLangid
+   || p->nPendingData>p->nMaxPendingData 
+  ){
     int rc = sqlite3Fts3PendingTermsFlush(p);
     if( rc!=SQLITE_OK ) return rc;
   }
   p->iPrevDocid = iDocid;
+  p->iPrevLangid = iLangid;
+  p->bPrevDelete = bDelete;
   return SQLITE_OK;
 }
 
@@ -123683,15 +152722,23 @@ SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *p){
 ** Argument apVal is the same as the similarly named argument passed to
 ** fts3InsertData(). Parameter iDocid is the docid of the new row.
 */
-static int fts3InsertTerms(Fts3Table *p, sqlite3_value **apVal, u32 *aSz){
+static int fts3InsertTerms(
+  Fts3Table *p, 
+  int iLangid, 
+  sqlite3_value **apVal, 
+  u32 *aSz
+){
   int i;                          /* Iterator variable */
   for(i=2; i<p->nColumn+2; i++){
-    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
-    int rc = fts3PendingTermsAdd(p, zText, i-2, &aSz[i-2]);
-    if( rc!=SQLITE_OK ){
-      return rc;
+    int iCol = i-2;
+    if( p->abNotindexed[iCol]==0 ){
+      const char *zText = (const char *)sqlite3_value_text(apVal[i]);
+      int rc = fts3PendingTermsAdd(p, iLangid, zText, iCol, &aSz[iCol]);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
     }
-    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
   }
   return SQLITE_OK;
 }
@@ -123708,6 +152755,7 @@ static int fts3InsertTerms(Fts3Table *p, sqlite3_value **apVal, u32 *aSz){
 **   apVal[p->nColumn+1]     Right-most user-defined column
 **   apVal[p->nColumn+2]     Hidden column with same name as table
 **   apVal[p->nColumn+3]     Hidden "docid" column (alias for rowid)
+**   apVal[p->nColumn+4]     Hidden languageid column
 */
 static int fts3InsertData(
   Fts3Table *p,                   /* Full-text table */
@@ -123738,9 +152786,13 @@ static int fts3InsertData(
   ** defined columns in the FTS3 table, plus one for the docid field.
   */
   rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]);
-  if( rc!=SQLITE_OK ){
-    return rc;
+  if( rc==SQLITE_OK && p->zLanguageid ){
+    rc = sqlite3_bind_int(
+        pContentInsert, p->nColumn+2, 
+        sqlite3_value_int(apVal[p->nColumn+4])
+    );
   }
+  if( rc!=SQLITE_OK ) return rc;
 
   /* There is a quirk here. The users INSERT statement may have specified
   ** a value for the "rowid" field, for the "docid" field, or for both.
@@ -123801,6 +152853,15 @@ static int fts3DeleteAll(Fts3Table *p, int bContent){
 }
 
 /*
+**
+*/
+static int langidFromSelect(Fts3Table *p, sqlite3_stmt *pSelect){
+  int iLangid = 0;
+  if( p->zLanguageid ) iLangid = sqlite3_column_int(pSelect, p->nColumn+1);
+  return iLangid;
+}
+
+/*
 ** The first element in the apVal[] array is assumed to contain the docid
 ** (an integer) of a row about to be deleted. Remove all terms from the
 ** full-text index.
@@ -123809,26 +152870,35 @@ static void fts3DeleteTerms(
   int *pRC,               /* Result code */
   Fts3Table *p,           /* The FTS table to delete from */
   sqlite3_value *pRowid,  /* The docid to be deleted */
-  u32 *aSz                /* Sizes of deleted document written here */
+  u32 *aSz,               /* Sizes of deleted document written here */
+  int *pbFound            /* OUT: Set to true if row really does exist */
 ){
   int rc;
   sqlite3_stmt *pSelect;
 
+  assert( *pbFound==0 );
   if( *pRC ) return;
   rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
   if( rc==SQLITE_OK ){
     if( SQLITE_ROW==sqlite3_step(pSelect) ){
       int i;
-      for(i=1; i<=p->nColumn; i++){
-        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
-        rc = fts3PendingTermsAdd(p, zText, -1, &aSz[i-1]);
-        if( rc!=SQLITE_OK ){
-          sqlite3_reset(pSelect);
-          *pRC = rc;
-          return;
+      int iLangid = langidFromSelect(p, pSelect);
+      i64 iDocid = sqlite3_column_int64(pSelect, 0);
+      rc = fts3PendingTermsDocid(p, 1, iLangid, iDocid);
+      for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
+        int iCol = i-1;
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
+          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
         }
-        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
       }
+      if( rc!=SQLITE_OK ){
+        sqlite3_reset(pSelect);
+        *pRC = rc;
+        return;
+      }
+      *pbFound = 1;
     }
     rc = sqlite3_reset(pSelect);
   }else{
@@ -123841,7 +152911,7 @@ static void fts3DeleteTerms(
 ** Forward declaration to account for the circular dependency between
 ** functions fts3SegmentMerge() and fts3AllocateSegdirIdx().
 */
-static int fts3SegmentMerge(Fts3Table *, int, int);
+static int fts3SegmentMerge(Fts3Table *, int, int, int);
 
 /* 
 ** This function allocates a new level iLevel index in the segdir table.
@@ -123860,6 +152930,7 @@ static int fts3SegmentMerge(Fts3Table *, int, int);
 */
 static int fts3AllocateSegdirIdx(
   Fts3Table *p, 
+  int iLangid,                    /* Language id */
   int iIndex,                     /* Index for p->aIndex */
   int iLevel, 
   int *piIdx
@@ -123868,10 +152939,15 @@ static int fts3AllocateSegdirIdx(
   sqlite3_stmt *pNextIdx;         /* Query for next idx at level iLevel */
   int iNext = 0;                  /* Result of query pNextIdx */
 
+  assert( iLangid>=0 );
+  assert( p->nIndex>=1 );
+
   /* Set variable iNext to the next available segdir index at level iLevel. */
   rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0);
   if( rc==SQLITE_OK ){
-    sqlite3_bind_int(pNextIdx, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel);
+    sqlite3_bind_int64(
+        pNextIdx, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)
+    );
     if( SQLITE_ROW==sqlite3_step(pNextIdx) ){
       iNext = sqlite3_column_int(pNextIdx, 0);
     }
@@ -123885,7 +152961,8 @@ static int fts3AllocateSegdirIdx(
     ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.
     */
     if( iNext>=FTS3_MERGE_COUNT ){
-      rc = fts3SegmentMerge(p, iIndex, iLevel);
+      fts3LogMerge(16, getAbsoluteLevel(p, iLangid, iIndex, iLevel));
+      rc = fts3SegmentMerge(p, iLangid, iIndex, iLevel);
       *piIdx = 0;
     }else{
       *piIdx = iNext;
@@ -123932,7 +153009,7 @@ SQLITE_PRIVATE int sqlite3Fts3ReadBlock(
   int rc;                         /* Return code */
 
   /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */
-  assert( pnBlob);
+  assert( pnBlob );
 
   if( p->pSegments ){
     rc = sqlite3_blob_reopen(p->pSegments, iBlockid);
@@ -124019,6 +153096,18 @@ static int fts3SegReaderRequire(Fts3SegReader *pReader, char *pFrom, int nByte){
 }
 
 /*
+** Set an Fts3SegReader cursor to point at EOF.
+*/
+static void fts3SegReaderSetEof(Fts3SegReader *pSeg){
+  if( !fts3SegReaderIsRootOnly(pSeg) ){
+    sqlite3_free(pSeg->aNode);
+    sqlite3_blob_close(pSeg->pBlob);
+    pSeg->pBlob = 0;
+  }
+  pSeg->aNode = 0;
+}
+
+/*
 ** Move the iterator passed as the first argument to the next term in the
 ** segment. If successful, SQLITE_OK is returned. If there is no next term,
 ** SQLITE_DONE. Otherwise, an SQLite error code.
@@ -124043,26 +153132,26 @@ static int fts3SegReaderNext(
 
     if( fts3SegReaderIsPending(pReader) ){
       Fts3HashElem *pElem = *(pReader->ppNextElem);
-      if( pElem==0 ){
-        pReader->aNode = 0;
-      }else{
+      sqlite3_free(pReader->aNode);
+      pReader->aNode = 0;
+      if( pElem ){
+        char *aCopy;
         PendingList *pList = (PendingList *)fts3HashData(pElem);
+        int nCopy = pList->nData+1;
         pReader->zTerm = (char *)fts3HashKey(pElem);
         pReader->nTerm = fts3HashKeysize(pElem);
-        pReader->nNode = pReader->nDoclist = pList->nData + 1;
-        pReader->aNode = pReader->aDoclist = pList->aData;
+        aCopy = (char*)sqlite3_malloc(nCopy);
+        if( !aCopy ) return SQLITE_NOMEM;
+        memcpy(aCopy, pList->aData, nCopy);
+        pReader->nNode = pReader->nDoclist = nCopy;
+        pReader->aNode = pReader->aDoclist = aCopy;
         pReader->ppNextElem++;
         assert( pReader->aNode );
       }
       return SQLITE_OK;
     }
 
-    if( !fts3SegReaderIsRootOnly(pReader) ){
-      sqlite3_free(pReader->aNode);
-      sqlite3_blob_close(pReader->pBlob);
-      pReader->pBlob = 0;
-    }
-    pReader->aNode = 0;
+    fts3SegReaderSetEof(pReader);
 
     /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf 
     ** blocks have already been traversed.  */
@@ -124091,8 +153180,8 @@ static int fts3SegReaderNext(
   
   /* Because of the FTS3_NODE_PADDING bytes of padding, the following is 
   ** safe (no risk of overread) even if the node data is corrupted. */
-  pNext += sqlite3Fts3GetVarint32(pNext, &nPrefix);
-  pNext += sqlite3Fts3GetVarint32(pNext, &nSuffix);
+  pNext += fts3GetVarint32(pNext, &nPrefix);
+  pNext += fts3GetVarint32(pNext, &nSuffix);
   if( nPrefix<0 || nSuffix<=0 
    || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] 
   ){
@@ -124115,7 +153204,7 @@ static int fts3SegReaderNext(
   memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);
   pReader->nTerm = nPrefix+nSuffix;
   pNext += nSuffix;
-  pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist);
+  pNext += fts3GetVarint32(pNext, &pReader->nDoclist);
   pReader->aDoclist = pNext;
   pReader->pOffsetList = 0;
 
@@ -124208,7 +153297,7 @@ static int fts3SegReaderNextDocid(
       /* The following line of code (and the "p++" below the while() loop) is
       ** normally all that is required to move pointer p to the desired 
       ** position. The exception is if this node is being loaded from disk
-      ** incrementally and pointer "p" now points to the first byte passed
+      ** incrementally and pointer "p" now points to the first byte past
       ** the populated part of pReader->aNode[].
       */
       while( *p | c ) c = *p++ & 0x80;
@@ -124228,6 +153317,7 @@ static int fts3SegReaderNextDocid(
       *pnOffsetList = (int)(p - pReader->pOffsetList - 1);
     }
 
+    /* List may have been edited in place by fts3EvalNearTrim() */
     while( p<pEnd && *p==0 ) p++;
   
     /* If there are no more entries in the doclist, set pOffsetList to
@@ -124266,7 +153356,7 @@ SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(
   int rc = SQLITE_OK;
   int pgsz = p->nPgsz;
 
-  assert( p->bHasStat );
+  assert( p->bFts4 );
   assert( pgsz>0 );
 
   for(ii=0; rc==SQLITE_OK && ii<pMsr->nSegment; ii++){
@@ -124294,12 +153384,14 @@ SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(
 ** second argument.
 */
 SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){
-  if( pReader && !fts3SegReaderIsPending(pReader) ){
-    sqlite3_free(pReader->zTerm);
+  if( pReader ){
+    if( !fts3SegReaderIsPending(pReader) ){
+      sqlite3_free(pReader->zTerm);
+    }
     if( !fts3SegReaderIsRootOnly(pReader) ){
       sqlite3_free(pReader->aNode);
-      sqlite3_blob_close(pReader->pBlob);
     }
+    sqlite3_blob_close(pReader->pBlob);
   }
   sqlite3_free(pReader);
 }
@@ -124309,6 +153401,7 @@ SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){
 */
 SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
   int iAge,                       /* Segment "age". */
+  int bLookup,                    /* True for a lookup only */
   sqlite3_int64 iStartLeaf,       /* First leaf to traverse */
   sqlite3_int64 iEndLeaf,         /* Final leaf to traverse */
   sqlite3_int64 iEndBlock,        /* Final block of segment */
@@ -124316,7 +153409,6 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
   int nRoot,                      /* Size of buffer containing root node */
   Fts3SegReader **ppReader        /* OUT: Allocated Fts3SegReader */
 ){
-  int rc = SQLITE_OK;             /* Return code */
   Fts3SegReader *pReader;         /* Newly allocated SegReader object */
   int nExtra = 0;                 /* Bytes to allocate segment root node */
 
@@ -124331,6 +153423,7 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
   }
   memset(pReader, 0, sizeof(Fts3SegReader));
   pReader->iIdx = iAge;
+  pReader->bLookup = bLookup!=0;
   pReader->iStartBlock = iStartLeaf;
   pReader->iLeafEndBlock = iEndLeaf;
   pReader->iEndBlock = iEndBlock;
@@ -124338,19 +153431,15 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
   if( nExtra ){
     /* The entire segment is stored in the root node. */
     pReader->aNode = (char *)&pReader[1];
+    pReader->rootOnly = 1;
     pReader->nNode = nRoot;
     memcpy(pReader->aNode, zRoot, nRoot);
     memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING);
   }else{
     pReader->iCurrentBlock = iStartLeaf-1;
   }
-
-  if( rc==SQLITE_OK ){
-    *ppReader = pReader;
-  }else{
-    sqlite3Fts3SegReaderFree(pReader);
-  }
-  return rc;
+  *ppReader = pReader;
+  return SQLITE_OK;
 }
 
 /*
@@ -124358,7 +153447,10 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(
 ** an array of pending terms by term. This occurs as part of flushing
 ** the contents of the pending-terms hash table to the database.
 */
-static int fts3CompareElemByTerm(const void *lhs, const void *rhs){
+static int SQLITE_CDECL fts3CompareElemByTerm(
+  const void *lhs,
+  const void *rhs
+){
   char *z1 = fts3HashKey(*(Fts3HashElem **)lhs);
   char *z2 = fts3HashKey(*(Fts3HashElem **)rhs);
   int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs);
@@ -124400,6 +153492,7 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
   Fts3SegReader **ppReader        /* OUT: SegReader for pending-terms */
 ){
   Fts3SegReader *pReader = 0;     /* Fts3SegReader object to return */
+  Fts3HashElem *pE;               /* Iterator variable */
   Fts3HashElem **aElem = 0;       /* Array of term hash entries to scan */
   int nElem = 0;                  /* Size of array at aElem */
   int rc = SQLITE_OK;             /* Return Code */
@@ -124408,7 +153501,6 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
   pHash = &p->aIndex[iIndex].hPending;
   if( bPrefix ){
     int nAlloc = 0;               /* Size of allocated array at aElem */
-    Fts3HashElem *pE = 0;         /* Iterator variable */
 
     for(pE=fts3HashFirst(pHash); pE; pE=fts3HashNext(pE)){
       char *zKey = (char *)fts3HashKey(pE);
@@ -124442,8 +153534,13 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(
 
   }else{
     /* The query is a simple term lookup that matches at most one term in
-    ** the index. All that is required is a straight hash-lookup. */
-    Fts3HashElem *pE = fts3HashFindElem(pHash, zTerm, nTerm);
+    ** the index. All that is required is a straight hash-lookup. 
+    **
+    ** Because the stack address of pE may be accessed via the aElem pointer
+    ** below, the "Fts3HashElem *pE" must be declared so that it is valid
+    ** within this entire function, not just this "else{...}" block.
+    */
+    pE = fts3HashFindElem(pHash, zTerm, nTerm);
     if( pE ){
       aElem = &pE;
       nElem = 1;
@@ -124623,27 +153720,55 @@ static int fts3WriteSegment(
   return rc;
 }
 
+/*
+** Find the largest relative level number in the table. If successful, set
+** *pnMax to this value and return SQLITE_OK. Otherwise, if an error occurs,
+** set *pnMax to zero and return an SQLite error code.
+*/
+SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *p, int *pnMax){
+  int rc;
+  int mxLevel = 0;
+  sqlite3_stmt *pStmt = 0;
+
+  rc = fts3SqlStmt(p, SQL_SELECT_MXLEVEL, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pStmt) ){
+      mxLevel = sqlite3_column_int(pStmt, 0);
+    }
+    rc = sqlite3_reset(pStmt);
+  }
+  *pnMax = mxLevel;
+  return rc;
+}
+
 /* 
 ** Insert a record into the %_segdir table.
 */
 static int fts3WriteSegdir(
   Fts3Table *p,                   /* Virtual table handle */
-  int iLevel,                     /* Value for "level" field */
+  sqlite3_int64 iLevel,           /* Value for "level" field (absolute level) */
   int iIdx,                       /* Value for "idx" field */
   sqlite3_int64 iStartBlock,      /* Value for "start_block" field */
   sqlite3_int64 iLeafEndBlock,    /* Value for "leaves_end_block" field */
   sqlite3_int64 iEndBlock,        /* Value for "end_block" field */
+  sqlite3_int64 nLeafData,        /* Bytes of leaf data in segment */
   char *zRoot,                    /* Blob value for "root" field */
   int nRoot                       /* Number of bytes in buffer zRoot */
 ){
   sqlite3_stmt *pStmt;
   int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0);
   if( rc==SQLITE_OK ){
-    sqlite3_bind_int(pStmt, 1, iLevel);
+    sqlite3_bind_int64(pStmt, 1, iLevel);
     sqlite3_bind_int(pStmt, 2, iIdx);
     sqlite3_bind_int64(pStmt, 3, iStartBlock);
     sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);
-    sqlite3_bind_int64(pStmt, 5, iEndBlock);
+    if( nLeafData==0 ){
+      sqlite3_bind_int64(pStmt, 5, iEndBlock);
+    }else{
+      char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);
+      if( !zEnd ) return SQLITE_NOMEM;
+      sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);
+    }
     sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
     sqlite3_step(pStmt);
     rc = sqlite3_reset(pStmt);
@@ -124939,6 +154064,7 @@ static int fts3SegWriterAdd(
     /* The current leaf node is full. Write it out to the database. */
     rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData);
     if( rc!=SQLITE_OK ) return rc;
+    p->nLeafAdd++;
 
     /* Add the current term to the interior node tree. The term added to
     ** the interior tree must:
@@ -124968,6 +154094,9 @@ static int fts3SegWriterAdd(
       nDoclist;                             /* Doclist data */
   }
 
+  /* Increase the total number of bytes written to account for the new entry. */
+  pWriter->nLeafData += nReq;
+
   /* If the buffer currently allocated is too small for this entry, realloc
   ** the buffer to make it large enough.
   */
@@ -125022,7 +154151,7 @@ static int fts3SegWriterAdd(
 static int fts3SegWriterFlush(
   Fts3Table *p,                   /* Virtual table handle */
   SegmentWriter *pWriter,         /* SegmentWriter to flush to the db */
-  int iLevel,                     /* Value for 'level' column of %_segdir */
+  sqlite3_int64 iLevel,           /* Value for 'level' column of %_segdir */
   int iIdx                        /* Value for 'idx' column of %_segdir */
 ){
   int rc;                         /* Return code */
@@ -125039,14 +154168,15 @@ static int fts3SegWriterFlush(
           pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot);
     }
     if( rc==SQLITE_OK ){
-      rc = fts3WriteSegdir(
-          p, iLevel, iIdx, pWriter->iFirst, iLastLeaf, iLast, zRoot, nRoot);
+      rc = fts3WriteSegdir(p, iLevel, iIdx, 
+          pWriter->iFirst, iLastLeaf, iLast, pWriter->nLeafData, zRoot, nRoot);
     }
   }else{
     /* The entire tree fits on the root node. Write it to the segdir table. */
-    rc = fts3WriteSegdir(
-        p, iLevel, iIdx, 0, 0, 0, pWriter->aData, pWriter->nData);
+    rc = fts3WriteSegdir(p, iLevel, iIdx, 
+        0, 0, 0, pWriter->nLeafData, pWriter->aData, pWriter->nData);
   }
+  p->nLeafAdd++;
   return rc;
 }
 
@@ -125100,7 +154230,12 @@ static int fts3IsEmpty(Fts3Table *p, sqlite3_value *pRowid, int *pisEmpty){
 **
 ** Return SQLITE_OK if successful, or an SQLite error code if not.
 */
-static int fts3SegmentMaxLevel(Fts3Table *p, int iIndex, int *pnMax){
+static int fts3SegmentMaxLevel(
+  Fts3Table *p, 
+  int iLangid,
+  int iIndex, 
+  sqlite3_int64 *pnMax
+){
   sqlite3_stmt *pStmt;
   int rc;
   assert( iIndex>=0 && iIndex<p->nIndex );
@@ -125113,15 +154248,71 @@ static int fts3SegmentMaxLevel(Fts3Table *p, int iIndex, int *pnMax){
   */
   rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
   if( rc!=SQLITE_OK ) return rc;
-  sqlite3_bind_int(pStmt, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
-  sqlite3_bind_int(pStmt, 2, (iIndex+1)*FTS3_SEGDIR_MAXLEVEL - 1);
+  sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+  sqlite3_bind_int64(pStmt, 2, 
+      getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+  );
   if( SQLITE_ROW==sqlite3_step(pStmt) ){
-    *pnMax = sqlite3_column_int(pStmt, 0);
+    *pnMax = sqlite3_column_int64(pStmt, 0);
   }
   return sqlite3_reset(pStmt);
 }
 
 /*
+** iAbsLevel is an absolute level that may be assumed to exist within
+** the database. This function checks if it is the largest level number
+** within its index. Assuming no error occurs, *pbMax is set to 1 if
+** iAbsLevel is indeed the largest level, or 0 otherwise, and SQLITE_OK
+** is returned. If an error occurs, an error code is returned and the
+** final value of *pbMax is undefined.
+*/
+static int fts3SegmentIsMaxLevel(Fts3Table *p, i64 iAbsLevel, int *pbMax){
+
+  /* Set pStmt to the compiled version of:
+  **
+  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
+  **
+  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
+  */
+  sqlite3_stmt *pStmt;
+  int rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+  sqlite3_bind_int64(pStmt, 1, iAbsLevel+1);
+  sqlite3_bind_int64(pStmt, 2, 
+      ((iAbsLevel/FTS3_SEGDIR_MAXLEVEL)+1) * FTS3_SEGDIR_MAXLEVEL
+  );
+
+  *pbMax = 0;
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    *pbMax = sqlite3_column_type(pStmt, 0)==SQLITE_NULL;
+  }
+  return sqlite3_reset(pStmt);
+}
+
+/*
+** Delete all entries in the %_segments table associated with the segment
+** opened with seg-reader pSeg. This function does not affect the contents
+** of the %_segdir table.
+*/
+static int fts3DeleteSegment(
+  Fts3Table *p,                   /* FTS table handle */
+  Fts3SegReader *pSeg             /* Segment to delete */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( pSeg->iStartBlock ){
+    sqlite3_stmt *pDelete;        /* SQL statement to delete rows */
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDelete, 1, pSeg->iStartBlock);
+      sqlite3_bind_int64(pDelete, 2, pSeg->iEndBlock);
+      sqlite3_step(pDelete);
+      rc = sqlite3_reset(pDelete);
+    }
+  }
+  return rc;
+}
+
+/*
 ** This function is used after merging multiple segments into a single large
 ** segment to delete the old, now redundant, segment b-trees. Specifically,
 ** it:
@@ -125137,24 +154328,18 @@ static int fts3SegmentMaxLevel(Fts3Table *p, int iIndex, int *pnMax){
 */
 static int fts3DeleteSegdir(
   Fts3Table *p,                   /* Virtual table handle */
+  int iLangid,                    /* Language id */
   int iIndex,                     /* Index for p->aIndex */
   int iLevel,                     /* Level of %_segdir entries to delete */
   Fts3SegReader **apSegment,      /* Array of SegReader objects */
   int nReader                     /* Size of array apSegment */
 ){
-  int rc;                         /* Return Code */
+  int rc = SQLITE_OK;             /* Return Code */
   int i;                          /* Iterator variable */
-  sqlite3_stmt *pDelete;          /* SQL statement to delete rows */
+  sqlite3_stmt *pDelete = 0;      /* SQL statement to delete rows */
 
-  rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0);
   for(i=0; rc==SQLITE_OK && i<nReader; i++){
-    Fts3SegReader *pSegment = apSegment[i];
-    if( pSegment->iStartBlock ){
-      sqlite3_bind_int64(pDelete, 1, pSegment->iStartBlock);
-      sqlite3_bind_int64(pDelete, 2, pSegment->iEndBlock);
-      sqlite3_step(pDelete);
-      rc = sqlite3_reset(pDelete);
-    }
+    rc = fts3DeleteSegment(p, apSegment[i]);
   }
   if( rc!=SQLITE_OK ){
     return rc;
@@ -125164,13 +154349,17 @@ static int fts3DeleteSegdir(
   if( iLevel==FTS3_SEGCURSOR_ALL ){
     rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0);
     if( rc==SQLITE_OK ){
-      sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL);
-      sqlite3_bind_int(pDelete, 2, (iIndex+1) * FTS3_SEGDIR_MAXLEVEL - 1);
+      sqlite3_bind_int64(pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));
+      sqlite3_bind_int64(pDelete, 2, 
+          getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)
+      );
     }
   }else{
     rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0);
     if( rc==SQLITE_OK ){
-      sqlite3_bind_int(pDelete, 1, iIndex*FTS3_SEGDIR_MAXLEVEL + iLevel);
+      sqlite3_bind_int64(
+          pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)
+      );
     }
   }
 
@@ -125190,9 +154379,13 @@ static int fts3DeleteSegdir(
 **
 ** If there are no entries in the input position list for column iCol, then
 ** *pnList is set to zero before returning.
+**
+** If parameter bZero is non-zero, then any part of the input list following
+** the end of the output list is zeroed before returning.
 */
 static void fts3ColumnFilter(
   int iCol,                       /* Column to filter on */
+  int bZero,                      /* Zero out anything following *ppList */
   char **ppList,                  /* IN/OUT: Pointer to position list */
   int *pnList                     /* IN/OUT: Size of buffer *ppList in bytes */
 ){
@@ -125218,9 +154411,12 @@ static void fts3ColumnFilter(
       break;
     }
     p = &pList[1];
-    p += sqlite3Fts3GetVarint32(p, &iCurrent);
+    p += fts3GetVarint32(p, &iCurrent);
   }
 
+  if( bZero && &pList[nList]!=pEnd ){
+    memset(&pList[nList], 0, pEnd - &pList[nList]);
+  }
   *ppList = pList;
   *pnList = nList;
 }
@@ -125294,19 +154490,19 @@ SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(
       if( rc!=SQLITE_OK ) return rc;
       fts3SegReaderSort(pMsr->apSegment, nMerge, j, xCmp);
 
+      if( nList>0 && fts3SegReaderIsPending(apSegment[0]) ){
+        rc = fts3MsrBufferData(pMsr, pList, nList+1);
+        if( rc!=SQLITE_OK ) return rc;
+        assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );
+        pList = pMsr->aBuffer;
+      }
+
       if( pMsr->iColFilter>=0 ){
-        fts3ColumnFilter(pMsr->iColFilter, &pList, &nList);
+        fts3ColumnFilter(pMsr->iColFilter, 1, &pList, &nList);
       }
 
       if( nList>0 ){
-        if( fts3SegReaderIsPending(apSegment[0]) ){
-          rc = fts3MsrBufferData(pMsr, pList, nList+1);
-          if( rc!=SQLITE_OK ) return rc;
-          *paPoslist = pMsr->aBuffer;
-          assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );
-        }else{
-          *paPoslist = pList;
-        }
+        *paPoslist = pList;
         *piDocid = iDocid;
         *pnPoslist = nList;
         break;
@@ -125333,11 +154529,16 @@ static int fts3SegReaderStart(
   ** b-tree leaf nodes contain more than one term.
   */
   for(i=0; pCsr->bRestart==0 && i<pCsr->nSegment; i++){
+    int res = 0;
     Fts3SegReader *pSeg = pCsr->apSegment[i];
     do {
       int rc = fts3SegReaderNext(p, pSeg, 0);
       if( rc!=SQLITE_OK ) return rc;
-    }while( zTerm && fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 );
+    }while( zTerm && (res = fts3SegReaderTermCmp(pSeg, zTerm, nTerm))<0 );
+
+    if( pSeg->bLookup && res!=0 ){
+      fts3SegReaderSetEof(pSeg);
+    }
   }
   fts3SegReaderSort(pCsr->apSegment, nSeg, nSeg, fts3SegReaderCmp);
 
@@ -125458,7 +154659,12 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(
     ** forward. Then sort the list in order of current term again.  
     */
     for(i=0; i<pCsr->nAdvance; i++){
-      rc = fts3SegReaderNext(p, apSegment[i], 0);
+      Fts3SegReader *pSeg = apSegment[i];
+      if( pSeg->bLookup ){
+        fts3SegReaderSetEof(pSeg);
+      }else{
+        rc = fts3SegReaderNext(p, pSeg, 0);
+      }
       if( rc!=SQLITE_OK ) return rc;
     }
     fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp);
@@ -125524,8 +154730,8 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(
       fts3SegReaderSort(apSegment, nMerge, nMerge, xCmp);
       while( apSegment[0]->pOffsetList ){
         int j;                    /* Number of segments that share a docid */
-        char *pList;
-        int nList;
+        char *pList = 0;
+        int nList = 0;
         int nByte;
         sqlite3_int64 iDocid = apSegment[0]->iDocid;
         fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);
@@ -125539,7 +154745,7 @@ SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(
         }
 
         if( isColFilter ){
-          fts3ColumnFilter(pFilter->iCol, &pList, &nList);
+          fts3ColumnFilter(pFilter->iCol, 0, &pList, &nList);
         }
 
         if( !isIgnoreEmpty || nList>0 ){
@@ -125619,6 +154825,140 @@ SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(
 }
 
 /*
+** Decode the "end_block" field, selected by column iCol of the SELECT 
+** statement passed as the first argument. 
+**
+** The "end_block" field may contain either an integer, or a text field
+** containing the text representation of two non-negative integers separated 
+** by one or more space (0x20) characters. In the first case, set *piEndBlock 
+** to the integer value and *pnByte to zero before returning. In the second, 
+** set *piEndBlock to the first value and *pnByte to the second.
+*/
+static void fts3ReadEndBlockField(
+  sqlite3_stmt *pStmt, 
+  int iCol, 
+  i64 *piEndBlock,
+  i64 *pnByte
+){
+  const unsigned char *zText = sqlite3_column_text(pStmt, iCol);
+  if( zText ){
+    int i;
+    int iMul = 1;
+    i64 iVal = 0;
+    for(i=0; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
+    }
+    *piEndBlock = iVal;
+    while( zText[i]==' ' ) i++;
+    iVal = 0;
+    if( zText[i]=='-' ){
+      i++;
+      iMul = -1;
+    }
+    for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
+    }
+    *pnByte = (iVal * (i64)iMul);
+  }
+}
+
+
+/*
+** A segment of size nByte bytes has just been written to absolute level
+** iAbsLevel. Promote any segments that should be promoted as a result.
+*/
+static int fts3PromoteSegments(
+  Fts3Table *p,                   /* FTS table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level just updated */
+  sqlite3_int64 nByte             /* Size of new segment at iAbsLevel */
+){
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pRange;
+
+  rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE2, &pRange, 0);
+
+  if( rc==SQLITE_OK ){
+    int bOk = 0;
+    i64 iLast = (iAbsLevel/FTS3_SEGDIR_MAXLEVEL + 1) * FTS3_SEGDIR_MAXLEVEL - 1;
+    i64 nLimit = (nByte*3)/2;
+
+    /* Loop through all entries in the %_segdir table corresponding to 
+    ** segments in this index on levels greater than iAbsLevel. If there is
+    ** at least one such segment, and it is possible to determine that all 
+    ** such segments are smaller than nLimit bytes in size, they will be 
+    ** promoted to level iAbsLevel.  */
+    sqlite3_bind_int64(pRange, 1, iAbsLevel+1);
+    sqlite3_bind_int64(pRange, 2, iLast);
+    while( SQLITE_ROW==sqlite3_step(pRange) ){
+      i64 nSize = 0, dummy;
+      fts3ReadEndBlockField(pRange, 2, &dummy, &nSize);
+      if( nSize<=0 || nSize>nLimit ){
+        /* If nSize==0, then the %_segdir.end_block field does not not 
+        ** contain a size value. This happens if it was written by an
+        ** old version of FTS. In this case it is not possible to determine
+        ** the size of the segment, and so segment promotion does not
+        ** take place.  */
+        bOk = 0;
+        break;
+      }
+      bOk = 1;
+    }
+    rc = sqlite3_reset(pRange);
+
+    if( bOk ){
+      int iIdx = 0;
+      sqlite3_stmt *pUpdate1 = 0;
+      sqlite3_stmt *pUpdate2 = 0;
+
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL_IDX, &pUpdate1, 0);
+      }
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL, &pUpdate2, 0);
+      }
+
+      if( rc==SQLITE_OK ){
+
+        /* Loop through all %_segdir entries for segments in this index with
+        ** levels equal to or greater than iAbsLevel. As each entry is visited,
+        ** updated it to set (level = -1) and (idx = N), where N is 0 for the
+        ** oldest segment in the range, 1 for the next oldest, and so on.
+        **
+        ** In other words, move all segments being promoted to level -1,
+        ** setting the "idx" fields as appropriate to keep them in the same
+        ** order. The contents of level -1 (which is never used, except
+        ** transiently here), will be moved back to level iAbsLevel below.  */
+        sqlite3_bind_int64(pRange, 1, iAbsLevel);
+        while( SQLITE_ROW==sqlite3_step(pRange) ){
+          sqlite3_bind_int(pUpdate1, 1, iIdx++);
+          sqlite3_bind_int(pUpdate1, 2, sqlite3_column_int(pRange, 0));
+          sqlite3_bind_int(pUpdate1, 3, sqlite3_column_int(pRange, 1));
+          sqlite3_step(pUpdate1);
+          rc = sqlite3_reset(pUpdate1);
+          if( rc!=SQLITE_OK ){
+            sqlite3_reset(pRange);
+            break;
+          }
+        }
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3_reset(pRange);
+      }
+
+      /* Move level -1 to level iAbsLevel */
+      if( rc==SQLITE_OK ){
+        sqlite3_bind_int64(pUpdate2, 1, iAbsLevel);
+        sqlite3_step(pUpdate2);
+        rc = sqlite3_reset(pUpdate2);
+      }
+    }
+  }
+
+
+  return rc;
+}
+
+/*
 ** Merge all level iLevel segments in the database into a single 
 ** iLevel+1 segment. Or, if iLevel<0, merge all segments into a
 ** single segment with a level equal to the numerically largest level 
@@ -125629,14 +154969,20 @@ SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(
 ** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 
 ** an SQLite error code is returned.
 */
-static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){
+static int fts3SegmentMerge(
+  Fts3Table *p, 
+  int iLangid,                    /* Language id to merge */
+  int iIndex,                     /* Index in p->aIndex[] to merge */
+  int iLevel                      /* Level to merge */
+){
   int rc;                         /* Return code */
   int iIdx = 0;                   /* Index of new segment */
-  int iNewLevel = 0;              /* Level/index to create new segment at */
+  sqlite3_int64 iNewLevel = 0;    /* Level/index to create new segment at */
   SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */
   Fts3SegFilter filter;           /* Segment term filter condition */
-  Fts3MultiSegReader csr;        /* Cursor to iterate through level(s) */
+  Fts3MultiSegReader csr;         /* Cursor to iterate through level(s) */
   int bIgnoreEmpty = 0;           /* True to ignore empty segments */
+  i64 iMaxLevel = 0;              /* Max level number for this index/langid */
 
   assert( iLevel==FTS3_SEGCURSOR_ALL
        || iLevel==FTS3_SEGCURSOR_PENDING
@@ -125645,36 +154991,41 @@ static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){
   assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
   assert( iIndex>=0 && iIndex<p->nIndex );
 
-  rc = sqlite3Fts3SegReaderCursor(p, iIndex, iLevel, 0, 0, 1, 0, &csr);
+  rc = sqlite3Fts3SegReaderCursor(p, iLangid, iIndex, iLevel, 0, 0, 1, 0, &csr);
   if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;
 
+  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
+    rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iMaxLevel);
+    if( rc!=SQLITE_OK ) goto finished;
+  }
+
   if( iLevel==FTS3_SEGCURSOR_ALL ){
     /* This call is to merge all segments in the database to a single
-    ** segment. The level of the new segment is equal to the the numerically 
+    ** segment. The level of the new segment is equal to the numerically
     ** greatest segment level currently present in the database for this
     ** index. The idx of the new segment is always 0.  */
-    if( csr.nSegment==1 ){
+    if( csr.nSegment==1 && 0==fts3SegReaderIsPending(csr.apSegment[0]) ){
       rc = SQLITE_DONE;
       goto finished;
     }
-    rc = fts3SegmentMaxLevel(p, iIndex, &iNewLevel);
+    iNewLevel = iMaxLevel;
     bIgnoreEmpty = 1;
 
-  }else if( iLevel==FTS3_SEGCURSOR_PENDING ){
-    iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL; 
-    rc = fts3AllocateSegdirIdx(p, iIndex, 0, &iIdx);
   }else{
     /* This call is to merge all segments at level iLevel. find the next
     ** available segment index at level iLevel+1. The call to
     ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
     ** a single iLevel+2 segment if necessary.  */
-    rc = fts3AllocateSegdirIdx(p, iIndex, iLevel+1, &iIdx);
-    iNewLevel = iIndex * FTS3_SEGDIR_MAXLEVEL + iLevel+1;
+    assert( FTS3_SEGCURSOR_PENDING==-1 );
+    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);
+    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
+    bIgnoreEmpty = (iLevel!=FTS3_SEGCURSOR_PENDING) && (iNewLevel>iMaxLevel);
   }
   if( rc!=SQLITE_OK ) goto finished;
+
   assert( csr.nSegment>0 );
-  assert( iNewLevel>=(iIndex*FTS3_SEGDIR_MAXLEVEL) );
-  assert( iNewLevel<((iIndex+1)*FTS3_SEGDIR_MAXLEVEL) );
+  assert( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
+  assert( iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) );
 
   memset(&filter, 0, sizeof(Fts3SegFilter));
   filter.flags = FTS3_SEGMENT_REQUIRE_POS;
@@ -125688,13 +155039,22 @@ static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){
         csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
   }
   if( rc!=SQLITE_OK ) goto finished;
-  assert( pWriter );
+  assert( pWriter || bIgnoreEmpty );
 
   if( iLevel!=FTS3_SEGCURSOR_PENDING ){
-    rc = fts3DeleteSegdir(p, iIndex, iLevel, csr.apSegment, csr.nSegment);
+    rc = fts3DeleteSegdir(
+        p, iLangid, iIndex, iLevel, csr.apSegment, csr.nSegment
+    );
     if( rc!=SQLITE_OK ) goto finished;
   }
-  rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);
+  if( pWriter ){
+    rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);
+    if( rc==SQLITE_OK ){
+      if( iLevel==FTS3_SEGCURSOR_PENDING || iNewLevel<iMaxLevel ){
+        rc = fts3PromoteSegments(p, iNewLevel, pWriter->nLeafData);
+      }
+    }
+  }
 
  finished:
   fts3SegWriterFree(pWriter);
@@ -125704,16 +155064,38 @@ static int fts3SegmentMerge(Fts3Table *p, int iIndex, int iLevel){
 
 
 /* 
-** Flush the contents of pendingTerms to level 0 segments.
+** Flush the contents of pendingTerms to level 0 segments. 
 */
 SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
   int rc = SQLITE_OK;
   int i;
+        
   for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
-    rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_PENDING);
+    rc = fts3SegmentMerge(p, p->iPrevLangid, i, FTS3_SEGCURSOR_PENDING);
     if( rc==SQLITE_DONE ) rc = SQLITE_OK;
   }
   sqlite3Fts3PendingTermsClear(p);
+
+  /* Determine the auto-incr-merge setting if unknown.  If enabled,
+  ** estimate the number of leaf blocks of content to be written
+  */
+  if( rc==SQLITE_OK && p->bHasStat
+   && p->nAutoincrmerge==0xff && p->nLeafAdd>0
+  ){
+    sqlite3_stmt *pStmt = 0;
+    rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
+      rc = sqlite3_step(pStmt);
+      if( rc==SQLITE_ROW ){
+        p->nAutoincrmerge = sqlite3_column_int(pStmt, 0);
+        if( p->nAutoincrmerge==1 ) p->nAutoincrmerge = 8;
+      }else if( rc==SQLITE_DONE ){
+        p->nAutoincrmerge = 0;
+      }
+      rc = sqlite3_reset(pStmt);
+    }
+  }
   return rc;
 }
 
@@ -125824,12 +155206,13 @@ static void fts3UpdateDocTotals(
     return;
   }
   pBlob = (char*)&a[nStat];
-  rc = fts3SqlStmt(p, SQL_SELECT_DOCTOTAL, &pStmt, 0);
+  rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
   if( rc ){
     sqlite3_free(a);
     *pRC = rc;
     return;
   }
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
   if( sqlite3_step(pStmt)==SQLITE_ROW ){
     fts3DecodeIntArray(nStat, a,
          sqlite3_column_blob(pStmt, 0),
@@ -125837,7 +155220,12 @@ static void fts3UpdateDocTotals(
   }else{
     memset(a, 0, sizeof(u32)*(nStat) );
   }
-  sqlite3_reset(pStmt);
+  rc = sqlite3_reset(pStmt);
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(a);
+    *pRC = rc;
+    return;
+  }
   if( nChng<0 && a[0]<(u32)(-nChng) ){
     a[0] = 0;
   }else{
@@ -125853,29 +155241,48 @@ static void fts3UpdateDocTotals(
     a[i+1] = x;
   }
   fts3EncodeIntArray(nStat, a, pBlob, &nBlob);
-  rc = fts3SqlStmt(p, SQL_REPLACE_DOCTOTAL, &pStmt, 0);
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
   if( rc ){
     sqlite3_free(a);
     *pRC = rc;
     return;
   }
-  sqlite3_bind_blob(pStmt, 1, pBlob, nBlob, SQLITE_STATIC);
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);
+  sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, SQLITE_STATIC);
   sqlite3_step(pStmt);
   *pRC = sqlite3_reset(pStmt);
   sqlite3_free(a);
 }
 
+/*
+** Merge the entire database so that there is one segment for each 
+** iIndex/iLangid combination.
+*/
 static int fts3DoOptimize(Fts3Table *p, int bReturnDone){
-  int i;
   int bSeenDone = 0;
-  int rc = SQLITE_OK;
-  for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
-    rc = fts3SegmentMerge(p, i, FTS3_SEGCURSOR_ALL);
-    if( rc==SQLITE_DONE ){
-      bSeenDone = 1;
-      rc = SQLITE_OK;
+  int rc;
+  sqlite3_stmt *pAllLangid = 0;
+
+  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);
+    sqlite3_bind_int(pAllLangid, 2, p->nIndex);
+    while( sqlite3_step(pAllLangid)==SQLITE_ROW ){
+      int i;
+      int iLangid = sqlite3_column_int(pAllLangid, 0);
+      for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){
+        rc = fts3SegmentMerge(p, iLangid, i, FTS3_SEGCURSOR_ALL);
+        if( rc==SQLITE_DONE ){
+          bSeenDone = 1;
+          rc = SQLITE_OK;
+        }
+      }
     }
+    rc2 = sqlite3_reset(pAllLangid);
+    if( rc==SQLITE_OK ) rc = rc2;
   }
+
   sqlite3Fts3SegmentsClose(p);
   sqlite3Fts3PendingTermsClear(p);
 
@@ -125926,12 +155333,15 @@ static int fts3DoRebuild(Fts3Table *p){
 
     while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
       int iCol;
-      rc = fts3PendingTermsDocid(p, sqlite3_column_int64(pStmt, 0));
-      aSz[p->nColumn] = 0;
+      int iLangid = langidFromSelect(p, pStmt);
+      rc = fts3PendingTermsDocid(p, 0, iLangid, sqlite3_column_int64(pStmt, 0));
+      memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
-        const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
-        rc = fts3PendingTermsAdd(p, z, iCol, &aSz[iCol]);
-        aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        if( p->abNotindexed[iCol]==0 ){
+          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
+          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        }
       }
       if( p->bHasDocsize ){
         fts3InsertDocsize(&rc, p, aSz);
@@ -125946,7 +155356,7 @@ static int fts3DoRebuild(Fts3Table *p){
         }
       }
     }
-    if( p->bHasStat ){
+    if( p->bFts4 ){
       fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nEntry);
     }
     sqlite3_free(aSz);
@@ -125962,6 +155372,1716 @@ static int fts3DoRebuild(Fts3Table *p){
   return rc;
 }
 
+
+/*
+** This function opens a cursor used to read the input data for an 
+** incremental merge operation. Specifically, it opens a cursor to scan
+** the oldest nSeg segments (idx=0 through idx=(nSeg-1)) in absolute 
+** level iAbsLevel.
+*/
+static int fts3IncrmergeCsr(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level to open */
+  int nSeg,                       /* Number of segments to merge */
+  Fts3MultiSegReader *pCsr        /* Cursor object to populate */
+){
+  int rc;                         /* Return Code */
+  sqlite3_stmt *pStmt = 0;        /* Statement used to read %_segdir entry */  
+  int nByte;                      /* Bytes allocated at pCsr->apSegment[] */
+
+  /* Allocate space for the Fts3MultiSegReader.aCsr[] array */
+  memset(pCsr, 0, sizeof(*pCsr));
+  nByte = sizeof(Fts3SegReader *) * nSeg;
+  pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc(nByte);
+
+  if( pCsr->apSegment==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    memset(pCsr->apSegment, 0, nByte);
+    rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);
+  }
+  if( rc==SQLITE_OK ){
+    int i;
+    int rc2;
+    sqlite3_bind_int64(pStmt, 1, iAbsLevel);
+    assert( pCsr->nSegment==0 );
+    for(i=0; rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW && i<nSeg; i++){
+      rc = sqlite3Fts3SegReaderNew(i, 0,
+          sqlite3_column_int64(pStmt, 1),        /* segdir.start_block */
+          sqlite3_column_int64(pStmt, 2),        /* segdir.leaves_end_block */
+          sqlite3_column_int64(pStmt, 3),        /* segdir.end_block */
+          sqlite3_column_blob(pStmt, 4),         /* segdir.root */
+          sqlite3_column_bytes(pStmt, 4),        /* segdir.root */
+          &pCsr->apSegment[i]
+      );
+      pCsr->nSegment++;
+    }
+    rc2 = sqlite3_reset(pStmt);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  return rc;
+}
+
+typedef struct IncrmergeWriter IncrmergeWriter;
+typedef struct NodeWriter NodeWriter;
+typedef struct Blob Blob;
+typedef struct NodeReader NodeReader;
+
+/*
+** An instance of the following structure is used as a dynamic buffer
+** to build up nodes or other blobs of data in.
+**
+** The function blobGrowBuffer() is used to extend the allocation.
+*/
+struct Blob {
+  char *a;                        /* Pointer to allocation */
+  int n;                          /* Number of valid bytes of data in a[] */
+  int nAlloc;                     /* Allocated size of a[] (nAlloc>=n) */
+};
+
+/*
+** This structure is used to build up buffers containing segment b-tree 
+** nodes (blocks).
+*/
+struct NodeWriter {
+  sqlite3_int64 iBlock;           /* Current block id */
+  Blob key;                       /* Last key written to the current block */
+  Blob block;                     /* Current block image */
+};
+
+/*
+** An object of this type contains the state required to create or append
+** to an appendable b-tree segment.
+*/
+struct IncrmergeWriter {
+  int nLeafEst;                   /* Space allocated for leaf blocks */
+  int nWork;                      /* Number of leaf pages flushed */
+  sqlite3_int64 iAbsLevel;        /* Absolute level of input segments */
+  int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */
+  sqlite3_int64 iStart;           /* Block number of first allocated block */
+  sqlite3_int64 iEnd;             /* Block number of last allocated block */
+  sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */
+  u8 bNoLeafData;                 /* If true, store 0 for segment size */
+  NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];
+};
+
+/*
+** An object of the following type is used to read data from a single
+** FTS segment node. See the following functions:
+**
+**     nodeReaderInit()
+**     nodeReaderNext()
+**     nodeReaderRelease()
+*/
+struct NodeReader {
+  const char *aNode;
+  int nNode;
+  int iOff;                       /* Current offset within aNode[] */
+
+  /* Output variables. Containing the current node entry. */
+  sqlite3_int64 iChild;           /* Pointer to child node */
+  Blob term;                      /* Current term */
+  const char *aDoclist;           /* Pointer to doclist */
+  int nDoclist;                   /* Size of doclist in bytes */
+};
+
+/*
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, if the allocation at pBlob->a is not already at least nMin
+** bytes in size, extend (realloc) it to be so.
+**
+** If an OOM error occurs, set *pRc to SQLITE_NOMEM and leave pBlob->a
+** unmodified. Otherwise, if the allocation succeeds, update pBlob->nAlloc
+** to reflect the new size of the pBlob->a[] buffer.
+*/
+static void blobGrowBuffer(Blob *pBlob, int nMin, int *pRc){
+  if( *pRc==SQLITE_OK && nMin>pBlob->nAlloc ){
+    int nAlloc = nMin;
+    char *a = (char *)sqlite3_realloc(pBlob->a, nAlloc);
+    if( a ){
+      pBlob->nAlloc = nAlloc;
+      pBlob->a = a;
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+}
+
+/*
+** Attempt to advance the node-reader object passed as the first argument to
+** the next entry on the node. 
+**
+** Return an error code if an error occurs (SQLITE_NOMEM is possible). 
+** Otherwise return SQLITE_OK. If there is no next entry on the node
+** (e.g. because the current entry is the last) set NodeReader->aNode to
+** NULL to indicate EOF. Otherwise, populate the NodeReader structure output 
+** variables for the new entry.
+*/
+static int nodeReaderNext(NodeReader *p){
+  int bFirst = (p->term.n==0);    /* True for first term on the node */
+  int nPrefix = 0;                /* Bytes to copy from previous term */
+  int nSuffix = 0;                /* Bytes to append to the prefix */
+  int rc = SQLITE_OK;             /* Return code */
+
+  assert( p->aNode );
+  if( p->iChild && bFirst==0 ) p->iChild++;
+  if( p->iOff>=p->nNode ){
+    /* EOF */
+    p->aNode = 0;
+  }else{
+    if( bFirst==0 ){
+      p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);
+    }
+    p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);
+
+    blobGrowBuffer(&p->term, nPrefix+nSuffix, &rc);
+    if( rc==SQLITE_OK ){
+      memcpy(&p->term.a[nPrefix], &p->aNode[p->iOff], nSuffix);
+      p->term.n = nPrefix+nSuffix;
+      p->iOff += nSuffix;
+      if( p->iChild==0 ){
+        p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);
+        p->aDoclist = &p->aNode[p->iOff];
+        p->iOff += p->nDoclist;
+      }
+    }
+  }
+
+  assert( p->iOff<=p->nNode );
+
+  return rc;
+}
+
+/*
+** Release all dynamic resources held by node-reader object *p.
+*/
+static void nodeReaderRelease(NodeReader *p){
+  sqlite3_free(p->term.a);
+}
+
+/*
+** Initialize a node-reader object to read the node in buffer aNode/nNode.
+**
+** If successful, SQLITE_OK is returned and the NodeReader object set to 
+** point to the first entry on the node (if any). Otherwise, an SQLite
+** error code is returned.
+*/
+static int nodeReaderInit(NodeReader *p, const char *aNode, int nNode){
+  memset(p, 0, sizeof(NodeReader));
+  p->aNode = aNode;
+  p->nNode = nNode;
+
+  /* Figure out if this is a leaf or an internal node. */
+  if( p->aNode[0] ){
+    /* An internal node. */
+    p->iOff = 1 + sqlite3Fts3GetVarint(&p->aNode[1], &p->iChild);
+  }else{
+    p->iOff = 1;
+  }
+
+  return nodeReaderNext(p);
+}
+
+/*
+** This function is called while writing an FTS segment each time a leaf o
+** node is finished and written to disk. The key (zTerm/nTerm) is guaranteed
+** to be greater than the largest key on the node just written, but smaller
+** than or equal to the first key that will be written to the next leaf
+** node.
+**
+** The block id of the leaf node just written to disk may be found in
+** (pWriter->aNodeWriter[0].iBlock) when this function is called.
+*/
+static int fts3IncrmergePush(
+  Fts3Table *p,                   /* Fts3 table handle */
+  IncrmergeWriter *pWriter,       /* Writer object */
+  const char *zTerm,              /* Term to write to internal node */
+  int nTerm                       /* Bytes at zTerm */
+){
+  sqlite3_int64 iPtr = pWriter->aNodeWriter[0].iBlock;
+  int iLayer;
+
+  assert( nTerm>0 );
+  for(iLayer=1; ALWAYS(iLayer<FTS_MAX_APPENDABLE_HEIGHT); iLayer++){
+    sqlite3_int64 iNextPtr = 0;
+    NodeWriter *pNode = &pWriter->aNodeWriter[iLayer];
+    int rc = SQLITE_OK;
+    int nPrefix;
+    int nSuffix;
+    int nSpace;
+
+    /* Figure out how much space the key will consume if it is written to
+    ** the current node of layer iLayer. Due to the prefix compression, 
+    ** the space required changes depending on which node the key is to
+    ** be added to.  */
+    nPrefix = fts3PrefixCompress(pNode->key.a, pNode->key.n, zTerm, nTerm);
+    nSuffix = nTerm - nPrefix;
+    nSpace  = sqlite3Fts3VarintLen(nPrefix);
+    nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+
+    if( pNode->key.n==0 || (pNode->block.n + nSpace)<=p->nNodeSize ){ 
+      /* If the current node of layer iLayer contains zero keys, or if adding
+      ** the key to it will not cause it to grow to larger than nNodeSize 
+      ** bytes in size, write the key here.  */
+
+      Blob *pBlk = &pNode->block;
+      if( pBlk->n==0 ){
+        blobGrowBuffer(pBlk, p->nNodeSize, &rc);
+        if( rc==SQLITE_OK ){
+          pBlk->a[0] = (char)iLayer;
+          pBlk->n = 1 + sqlite3Fts3PutVarint(&pBlk->a[1], iPtr);
+        }
+      }
+      blobGrowBuffer(pBlk, pBlk->n + nSpace, &rc);
+      blobGrowBuffer(&pNode->key, nTerm, &rc);
+
+      if( rc==SQLITE_OK ){
+        if( pNode->key.n ){
+          pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nPrefix);
+        }
+        pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nSuffix);
+        memcpy(&pBlk->a[pBlk->n], &zTerm[nPrefix], nSuffix);
+        pBlk->n += nSuffix;
+
+        memcpy(pNode->key.a, zTerm, nTerm);
+        pNode->key.n = nTerm;
+      }
+    }else{
+      /* Otherwise, flush the current node of layer iLayer to disk.
+      ** Then allocate a new, empty sibling node. The key will be written
+      ** into the parent of this node. */
+      rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);
+
+      assert( pNode->block.nAlloc>=p->nNodeSize );
+      pNode->block.a[0] = (char)iLayer;
+      pNode->block.n = 1 + sqlite3Fts3PutVarint(&pNode->block.a[1], iPtr+1);
+
+      iNextPtr = pNode->iBlock;
+      pNode->iBlock++;
+      pNode->key.n = 0;
+    }
+
+    if( rc!=SQLITE_OK || iNextPtr==0 ) return rc;
+    iPtr = iNextPtr;
+  }
+
+  assert( 0 );
+  return 0;
+}
+
+/*
+** Append a term and (optionally) doclist to the FTS segment node currently
+** stored in blob *pNode. The node need not contain any terms, but the
+** header must be written before this function is called.
+**
+** A node header is a single 0x00 byte for a leaf node, or a height varint
+** followed by the left-hand-child varint for an internal node.
+**
+** The term to be appended is passed via arguments zTerm/nTerm. For a 
+** leaf node, the doclist is passed as aDoclist/nDoclist. For an internal
+** node, both aDoclist and nDoclist must be passed 0.
+**
+** If the size of the value in blob pPrev is zero, then this is the first
+** term written to the node. Otherwise, pPrev contains a copy of the 
+** previous term. Before this function returns, it is updated to contain a
+** copy of zTerm/nTerm.
+**
+** It is assumed that the buffer associated with pNode is already large
+** enough to accommodate the new entry. The buffer associated with pPrev
+** is extended by this function if requrired.
+**
+** If an error (i.e. OOM condition) occurs, an SQLite error code is
+** returned. Otherwise, SQLITE_OK.
+*/
+static int fts3AppendToNode(
+  Blob *pNode,                    /* Current node image to append to */
+  Blob *pPrev,                    /* Buffer containing previous term written */
+  const char *zTerm,              /* New term to write */
+  int nTerm,                      /* Size of zTerm in bytes */
+  const char *aDoclist,           /* Doclist (or NULL) to write */
+  int nDoclist                    /* Size of aDoclist in bytes */ 
+){
+  int rc = SQLITE_OK;             /* Return code */
+  int bFirst = (pPrev->n==0);     /* True if this is the first term written */
+  int nPrefix;                    /* Size of term prefix in bytes */
+  int nSuffix;                    /* Size of term suffix in bytes */
+
+  /* Node must have already been started. There must be a doclist for a
+  ** leaf node, and there must not be a doclist for an internal node.  */
+  assert( pNode->n>0 );
+  assert( (pNode->a[0]=='\0')==(aDoclist!=0) );
+
+  blobGrowBuffer(pPrev, nTerm, &rc);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nPrefix = fts3PrefixCompress(pPrev->a, pPrev->n, zTerm, nTerm);
+  nSuffix = nTerm - nPrefix;
+  memcpy(pPrev->a, zTerm, nTerm);
+  pPrev->n = nTerm;
+
+  if( bFirst==0 ){
+    pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nPrefix);
+  }
+  pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nSuffix);
+  memcpy(&pNode->a[pNode->n], &zTerm[nPrefix], nSuffix);
+  pNode->n += nSuffix;
+
+  if( aDoclist ){
+    pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nDoclist);
+    memcpy(&pNode->a[pNode->n], aDoclist, nDoclist);
+    pNode->n += nDoclist;
+  }
+
+  assert( pNode->n<=pNode->nAlloc );
+
+  return SQLITE_OK;
+}
+
+/*
+** Append the current term and doclist pointed to by cursor pCsr to the
+** appendable b-tree segment opened for writing by pWriter.
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise.
+*/
+static int fts3IncrmergeAppend(
+  Fts3Table *p,                   /* Fts3 table handle */
+  IncrmergeWriter *pWriter,       /* Writer object */
+  Fts3MultiSegReader *pCsr        /* Cursor containing term and doclist */
+){
+  const char *zTerm = pCsr->zTerm;
+  int nTerm = pCsr->nTerm;
+  const char *aDoclist = pCsr->aDoclist;
+  int nDoclist = pCsr->nDoclist;
+  int rc = SQLITE_OK;           /* Return code */
+  int nSpace;                   /* Total space in bytes required on leaf */
+  int nPrefix;                  /* Size of prefix shared with previous term */
+  int nSuffix;                  /* Size of suffix (nTerm - nPrefix) */
+  NodeWriter *pLeaf;            /* Object used to write leaf nodes */
+
+  pLeaf = &pWriter->aNodeWriter[0];
+  nPrefix = fts3PrefixCompress(pLeaf->key.a, pLeaf->key.n, zTerm, nTerm);
+  nSuffix = nTerm - nPrefix;
+
+  nSpace  = sqlite3Fts3VarintLen(nPrefix);
+  nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+  nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;
+
+  /* If the current block is not empty, and if adding this term/doclist
+  ** to the current block would make it larger than Fts3Table.nNodeSize
+  ** bytes, write this block out to the database. */
+  if( pLeaf->block.n>0 && (pLeaf->block.n + nSpace)>p->nNodeSize ){
+    rc = fts3WriteSegment(p, pLeaf->iBlock, pLeaf->block.a, pLeaf->block.n);
+    pWriter->nWork++;
+
+    /* Add the current term to the parent node. The term added to the 
+    ** parent must:
+    **
+    **   a) be greater than the largest term on the leaf node just written
+    **      to the database (still available in pLeaf->key), and
+    **
+    **   b) be less than or equal to the term about to be added to the new
+    **      leaf node (zTerm/nTerm).
+    **
+    ** In other words, it must be the prefix of zTerm 1 byte longer than
+    ** the common prefix (if any) of zTerm and pWriter->zTerm.
+    */
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergePush(p, pWriter, zTerm, nPrefix+1);
+    }
+
+    /* Advance to the next output block */
+    pLeaf->iBlock++;
+    pLeaf->key.n = 0;
+    pLeaf->block.n = 0;
+
+    nSuffix = nTerm;
+    nSpace  = 1;
+    nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;
+    nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;
+  }
+
+  pWriter->nLeafData += nSpace;
+  blobGrowBuffer(&pLeaf->block, pLeaf->block.n + nSpace, &rc);
+  if( rc==SQLITE_OK ){
+    if( pLeaf->block.n==0 ){
+      pLeaf->block.n = 1;
+      pLeaf->block.a[0] = '\0';
+    }
+    rc = fts3AppendToNode(
+        &pLeaf->block, &pLeaf->key, zTerm, nTerm, aDoclist, nDoclist
+    );
+  }
+
+  return rc;
+}
+
+/*
+** This function is called to release all dynamic resources held by the
+** merge-writer object pWriter, and if no error has occurred, to flush
+** all outstanding node buffers held by pWriter to disk.
+**
+** If *pRc is not SQLITE_OK when this function is called, then no attempt
+** is made to write any data to disk. Instead, this function serves only
+** to release outstanding resources.
+**
+** Otherwise, if *pRc is initially SQLITE_OK and an error occurs while
+** flushing buffers to disk, *pRc is set to an SQLite error code before
+** returning.
+*/
+static void fts3IncrmergeRelease(
+  Fts3Table *p,                   /* FTS3 table handle */
+  IncrmergeWriter *pWriter,       /* Merge-writer object */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  int i;                          /* Used to iterate through non-root layers */
+  int iRoot;                      /* Index of root in pWriter->aNodeWriter */
+  NodeWriter *pRoot;              /* NodeWriter for root node */
+  int rc = *pRc;                  /* Error code */
+
+  /* Set iRoot to the index in pWriter->aNodeWriter[] of the output segment 
+  ** root node. If the segment fits entirely on a single leaf node, iRoot
+  ** will be set to 0. If the root node is the parent of the leaves, iRoot
+  ** will be 1. And so on.  */
+  for(iRoot=FTS_MAX_APPENDABLE_HEIGHT-1; iRoot>=0; iRoot--){
+    NodeWriter *pNode = &pWriter->aNodeWriter[iRoot];
+    if( pNode->block.n>0 ) break;
+    assert( *pRc || pNode->block.nAlloc==0 );
+    assert( *pRc || pNode->key.nAlloc==0 );
+    sqlite3_free(pNode->block.a);
+    sqlite3_free(pNode->key.a);
+  }
+
+  /* Empty output segment. This is a no-op. */
+  if( iRoot<0 ) return;
+
+  /* The entire output segment fits on a single node. Normally, this means
+  ** the node would be stored as a blob in the "root" column of the %_segdir
+  ** table. However, this is not permitted in this case. The problem is that 
+  ** space has already been reserved in the %_segments table, and so the 
+  ** start_block and end_block fields of the %_segdir table must be populated. 
+  ** And, by design or by accident, released versions of FTS cannot handle 
+  ** segments that fit entirely on the root node with start_block!=0.
+  **
+  ** Instead, create a synthetic root node that contains nothing but a 
+  ** pointer to the single content node. So that the segment consists of a
+  ** single leaf and a single interior (root) node.
+  **
+  ** Todo: Better might be to defer allocating space in the %_segments 
+  ** table until we are sure it is needed.
+  */
+  if( iRoot==0 ){
+    Blob *pBlock = &pWriter->aNodeWriter[1].block;
+    blobGrowBuffer(pBlock, 1 + FTS3_VARINT_MAX, &rc);
+    if( rc==SQLITE_OK ){
+      pBlock->a[0] = 0x01;
+      pBlock->n = 1 + sqlite3Fts3PutVarint(
+          &pBlock->a[1], pWriter->aNodeWriter[0].iBlock
+      );
+    }
+    iRoot = 1;
+  }
+  pRoot = &pWriter->aNodeWriter[iRoot];
+
+  /* Flush all currently outstanding nodes to disk. */
+  for(i=0; i<iRoot; i++){
+    NodeWriter *pNode = &pWriter->aNodeWriter[i];
+    if( pNode->block.n>0 && rc==SQLITE_OK ){
+      rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);
+    }
+    sqlite3_free(pNode->block.a);
+    sqlite3_free(pNode->key.a);
+  }
+
+  /* Write the %_segdir record. */
+  if( rc==SQLITE_OK ){
+    rc = fts3WriteSegdir(p, 
+        pWriter->iAbsLevel+1,               /* level */
+        pWriter->iIdx,                      /* idx */
+        pWriter->iStart,                    /* start_block */
+        pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */
+        pWriter->iEnd,                      /* end_block */
+        (pWriter->bNoLeafData==0 ? pWriter->nLeafData : 0),   /* end_block */
+        pRoot->block.a, pRoot->block.n      /* root */
+    );
+  }
+  sqlite3_free(pRoot->block.a);
+  sqlite3_free(pRoot->key.a);
+
+  *pRc = rc;
+}
+
+/*
+** Compare the term in buffer zLhs (size in bytes nLhs) with that in
+** zRhs (size in bytes nRhs) using memcmp. If one term is a prefix of
+** the other, it is considered to be smaller than the other.
+**
+** Return -ve if zLhs is smaller than zRhs, 0 if it is equal, or +ve
+** if it is greater.
+*/
+static int fts3TermCmp(
+  const char *zLhs, int nLhs,     /* LHS of comparison */
+  const char *zRhs, int nRhs      /* RHS of comparison */
+){
+  int nCmp = MIN(nLhs, nRhs);
+  int res;
+
+  res = memcmp(zLhs, zRhs, nCmp);
+  if( res==0 ) res = nLhs - nRhs;
+
+  return res;
+}
+
+
+/*
+** Query to see if the entry in the %_segments table with blockid iEnd is 
+** NULL. If no error occurs and the entry is NULL, set *pbRes 1 before
+** returning. Otherwise, set *pbRes to 0. 
+**
+** Or, if an error occurs while querying the database, return an SQLite 
+** error code. The final value of *pbRes is undefined in this case.
+**
+** This is used to test if a segment is an "appendable" segment. If it
+** is, then a NULL entry has been inserted into the %_segments table
+** with blockid %_segdir.end_block.
+*/
+static int fts3IsAppendable(Fts3Table *p, sqlite3_int64 iEnd, int *pbRes){
+  int bRes = 0;                   /* Result to set *pbRes to */
+  sqlite3_stmt *pCheck = 0;       /* Statement to query database with */
+  int rc;                         /* Return code */
+
+  rc = fts3SqlStmt(p, SQL_SEGMENT_IS_APPENDABLE, &pCheck, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pCheck, 1, iEnd);
+    if( SQLITE_ROW==sqlite3_step(pCheck) ) bRes = 1;
+    rc = sqlite3_reset(pCheck);
+  }
+  
+  *pbRes = bRes;
+  return rc;
+}
+
+/*
+** This function is called when initializing an incremental-merge operation.
+** It checks if the existing segment with index value iIdx at absolute level 
+** (iAbsLevel+1) can be appended to by the incremental merge. If it can, the
+** merge-writer object *pWriter is initialized to write to it.
+**
+** An existing segment can be appended to by an incremental merge if:
+**
+**   * It was initially created as an appendable segment (with all required
+**     space pre-allocated), and
+**
+**   * The first key read from the input (arguments zKey and nKey) is 
+**     greater than the largest key currently stored in the potential
+**     output segment.
+*/
+static int fts3IncrmergeLoad(
+  Fts3Table *p,                   /* Fts3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */
+  int iIdx,                       /* Index of candidate output segment */
+  const char *zKey,               /* First key to write */
+  int nKey,                       /* Number of bytes in nKey */
+  IncrmergeWriter *pWriter        /* Populate this object */
+){
+  int rc;                         /* Return code */
+  sqlite3_stmt *pSelect = 0;      /* SELECT to read %_segdir entry */
+
+  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pSelect, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_int64 iStart = 0;     /* Value of %_segdir.start_block */
+    sqlite3_int64 iLeafEnd = 0;   /* Value of %_segdir.leaves_end_block */
+    sqlite3_int64 iEnd = 0;       /* Value of %_segdir.end_block */
+    const char *aRoot = 0;        /* Pointer to %_segdir.root buffer */
+    int nRoot = 0;                /* Size of aRoot[] in bytes */
+    int rc2;                      /* Return code from sqlite3_reset() */
+    int bAppendable = 0;          /* Set to true if segment is appendable */
+
+    /* Read the %_segdir entry for index iIdx absolute level (iAbsLevel+1) */
+    sqlite3_bind_int64(pSelect, 1, iAbsLevel+1);
+    sqlite3_bind_int(pSelect, 2, iIdx);
+    if( sqlite3_step(pSelect)==SQLITE_ROW ){
+      iStart = sqlite3_column_int64(pSelect, 1);
+      iLeafEnd = sqlite3_column_int64(pSelect, 2);
+      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
+      if( pWriter->nLeafData<0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
+      pWriter->bNoLeafData = (pWriter->nLeafData==0);
+      nRoot = sqlite3_column_bytes(pSelect, 4);
+      aRoot = sqlite3_column_blob(pSelect, 4);
+    }else{
+      return sqlite3_reset(pSelect);
+    }
+
+    /* Check for the zero-length marker in the %_segments table */
+    rc = fts3IsAppendable(p, iEnd, &bAppendable);
+
+    /* Check that zKey/nKey is larger than the largest key the candidate */
+    if( rc==SQLITE_OK && bAppendable ){
+      char *aLeaf = 0;
+      int nLeaf = 0;
+
+      rc = sqlite3Fts3ReadBlock(p, iLeafEnd, &aLeaf, &nLeaf, 0);
+      if( rc==SQLITE_OK ){
+        NodeReader reader;
+        for(rc = nodeReaderInit(&reader, aLeaf, nLeaf);
+            rc==SQLITE_OK && reader.aNode;
+            rc = nodeReaderNext(&reader)
+        ){
+          assert( reader.aNode );
+        }
+        if( fts3TermCmp(zKey, nKey, reader.term.a, reader.term.n)<=0 ){
+          bAppendable = 0;
+        }
+        nodeReaderRelease(&reader);
+      }
+      sqlite3_free(aLeaf);
+    }
+
+    if( rc==SQLITE_OK && bAppendable ){
+      /* It is possible to append to this segment. Set up the IncrmergeWriter
+      ** object to do so.  */
+      int i;
+      int nHeight = (int)aRoot[0];
+      NodeWriter *pNode;
+
+      pWriter->nLeafEst = (int)((iEnd - iStart) + 1)/FTS_MAX_APPENDABLE_HEIGHT;
+      pWriter->iStart = iStart;
+      pWriter->iEnd = iEnd;
+      pWriter->iAbsLevel = iAbsLevel;
+      pWriter->iIdx = iIdx;
+
+      for(i=nHeight+1; i<FTS_MAX_APPENDABLE_HEIGHT; i++){
+        pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
+      }
+
+      pNode = &pWriter->aNodeWriter[nHeight];
+      pNode->iBlock = pWriter->iStart + pWriter->nLeafEst*nHeight;
+      blobGrowBuffer(&pNode->block, MAX(nRoot, p->nNodeSize), &rc);
+      if( rc==SQLITE_OK ){
+        memcpy(pNode->block.a, aRoot, nRoot);
+        pNode->block.n = nRoot;
+      }
+
+      for(i=nHeight; i>=0 && rc==SQLITE_OK; i--){
+        NodeReader reader;
+        pNode = &pWriter->aNodeWriter[i];
+
+        rc = nodeReaderInit(&reader, pNode->block.a, pNode->block.n);
+        while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);
+        blobGrowBuffer(&pNode->key, reader.term.n, &rc);
+        if( rc==SQLITE_OK ){
+          memcpy(pNode->key.a, reader.term.a, reader.term.n);
+          pNode->key.n = reader.term.n;
+          if( i>0 ){
+            char *aBlock = 0;
+            int nBlock = 0;
+            pNode = &pWriter->aNodeWriter[i-1];
+            pNode->iBlock = reader.iChild;
+            rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
+            blobGrowBuffer(&pNode->block, MAX(nBlock, p->nNodeSize), &rc);
+            if( rc==SQLITE_OK ){
+              memcpy(pNode->block.a, aBlock, nBlock);
+              pNode->block.n = nBlock;
+            }
+            sqlite3_free(aBlock);
+          }
+        }
+        nodeReaderRelease(&reader);
+      }
+    }
+
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  return rc;
+}
+
+/*
+** Determine the largest segment index value that exists within absolute
+** level iAbsLevel+1. If no error occurs, set *piIdx to this value plus
+** one before returning SQLITE_OK. Or, if there are no segments at all 
+** within level iAbsLevel, set *piIdx to zero.
+**
+** If an error occurs, return an SQLite error code. The final value of
+** *piIdx is undefined in this case.
+*/
+static int fts3IncrmergeOutputIdx( 
+  Fts3Table *p,                   /* FTS Table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute index of input segments */
+  int *piIdx                      /* OUT: Next free index at iAbsLevel+1 */
+){
+  int rc;
+  sqlite3_stmt *pOutputIdx = 0;   /* SQL used to find output index */
+
+  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pOutputIdx, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pOutputIdx, 1, iAbsLevel+1);
+    sqlite3_step(pOutputIdx);
+    *piIdx = sqlite3_column_int(pOutputIdx, 0);
+    rc = sqlite3_reset(pOutputIdx);
+  }
+
+  return rc;
+}
+
+/* 
+** Allocate an appendable output segment on absolute level iAbsLevel+1
+** with idx value iIdx.
+**
+** In the %_segdir table, a segment is defined by the values in three
+** columns:
+**
+**     start_block
+**     leaves_end_block
+**     end_block
+**
+** When an appendable segment is allocated, it is estimated that the
+** maximum number of leaf blocks that may be required is the sum of the
+** number of leaf blocks consumed by the input segments, plus the number
+** of input segments, multiplied by two. This value is stored in stack 
+** variable nLeafEst.
+**
+** A total of 16*nLeafEst blocks are allocated when an appendable segment
+** is created ((1 + end_block - start_block)==16*nLeafEst). The contiguous
+** array of leaf nodes starts at the first block allocated. The array
+** of interior nodes that are parents of the leaf nodes start at block
+** (start_block + (1 + end_block - start_block) / 16). And so on.
+**
+** In the actual code below, the value "16" is replaced with the 
+** pre-processor macro FTS_MAX_APPENDABLE_HEIGHT.
+*/
+static int fts3IncrmergeWriter( 
+  Fts3Table *p,                   /* Fts3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */
+  int iIdx,                       /* Index of new output segment */
+  Fts3MultiSegReader *pCsr,       /* Cursor that data will be read from */
+  IncrmergeWriter *pWriter        /* Populate this object */
+){
+  int rc;                         /* Return Code */
+  int i;                          /* Iterator variable */
+  int nLeafEst = 0;               /* Blocks allocated for leaf nodes */
+  sqlite3_stmt *pLeafEst = 0;     /* SQL used to determine nLeafEst */
+  sqlite3_stmt *pFirstBlock = 0;  /* SQL used to determine first block */
+
+  /* Calculate nLeafEst. */
+  rc = fts3SqlStmt(p, SQL_MAX_LEAF_NODE_ESTIMATE, &pLeafEst, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pLeafEst, 1, iAbsLevel);
+    sqlite3_bind_int64(pLeafEst, 2, pCsr->nSegment);
+    if( SQLITE_ROW==sqlite3_step(pLeafEst) ){
+      nLeafEst = sqlite3_column_int(pLeafEst, 0);
+    }
+    rc = sqlite3_reset(pLeafEst);
+  }
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* Calculate the first block to use in the output segment */
+  rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pFirstBlock, 0);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pFirstBlock) ){
+      pWriter->iStart = sqlite3_column_int64(pFirstBlock, 0);
+      pWriter->iEnd = pWriter->iStart - 1;
+      pWriter->iEnd += nLeafEst * FTS_MAX_APPENDABLE_HEIGHT;
+    }
+    rc = sqlite3_reset(pFirstBlock);
+  }
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* Insert the marker in the %_segments table to make sure nobody tries
+  ** to steal the space just allocated. This is also used to identify 
+  ** appendable segments.  */
+  rc = fts3WriteSegment(p, pWriter->iEnd, 0, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  pWriter->iAbsLevel = iAbsLevel;
+  pWriter->nLeafEst = nLeafEst;
+  pWriter->iIdx = iIdx;
+
+  /* Set up the array of NodeWriter objects */
+  for(i=0; i<FTS_MAX_APPENDABLE_HEIGHT; i++){
+    pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Remove an entry from the %_segdir table. This involves running the 
+** following two statements:
+**
+**   DELETE FROM %_segdir WHERE level = :iAbsLevel AND idx = :iIdx
+**   UPDATE %_segdir SET idx = idx - 1 WHERE level = :iAbsLevel AND idx > :iIdx
+**
+** The DELETE statement removes the specific %_segdir level. The UPDATE 
+** statement ensures that the remaining segments have contiguously allocated
+** idx values.
+*/
+static int fts3RemoveSegdirEntry(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level to delete from */
+  int iIdx                        /* Index of %_segdir entry to delete */
+){
+  int rc;                         /* Return code */
+  sqlite3_stmt *pDelete = 0;      /* DELETE statement */
+
+  rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_ENTRY, &pDelete, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pDelete, 1, iAbsLevel);
+    sqlite3_bind_int(pDelete, 2, iIdx);
+    sqlite3_step(pDelete);
+    rc = sqlite3_reset(pDelete);
+  }
+
+  return rc;
+}
+
+/*
+** One or more segments have just been removed from absolute level iAbsLevel.
+** Update the 'idx' values of the remaining segments in the level so that
+** the idx values are a contiguous sequence starting from 0.
+*/
+static int fts3RepackSegdirLevel(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel         /* Absolute level to repack */
+){
+  int rc;                         /* Return code */
+  int *aIdx = 0;                  /* Array of remaining idx values */
+  int nIdx = 0;                   /* Valid entries in aIdx[] */
+  int nAlloc = 0;                 /* Allocated size of aIdx[] */
+  int i;                          /* Iterator variable */
+  sqlite3_stmt *pSelect = 0;      /* Select statement to read idx values */
+  sqlite3_stmt *pUpdate = 0;      /* Update statement to modify idx values */
+
+  rc = fts3SqlStmt(p, SQL_SELECT_INDEXES, &pSelect, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int64(pSelect, 1, iAbsLevel);
+    while( SQLITE_ROW==sqlite3_step(pSelect) ){
+      if( nIdx>=nAlloc ){
+        int *aNew;
+        nAlloc += 16;
+        aNew = sqlite3_realloc(aIdx, nAlloc*sizeof(int));
+        if( !aNew ){
+          rc = SQLITE_NOMEM;
+          break;
+        }
+        aIdx = aNew;
+      }
+      aIdx[nIdx++] = sqlite3_column_int(pSelect, 0);
+    }
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = fts3SqlStmt(p, SQL_SHIFT_SEGDIR_ENTRY, &pUpdate, 0);
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int64(pUpdate, 2, iAbsLevel);
+  }
+
+  assert( p->bIgnoreSavepoint==0 );
+  p->bIgnoreSavepoint = 1;
+  for(i=0; rc==SQLITE_OK && i<nIdx; i++){
+    if( aIdx[i]!=i ){
+      sqlite3_bind_int(pUpdate, 3, aIdx[i]);
+      sqlite3_bind_int(pUpdate, 1, i);
+      sqlite3_step(pUpdate);
+      rc = sqlite3_reset(pUpdate);
+    }
+  }
+  p->bIgnoreSavepoint = 0;
+
+  sqlite3_free(aIdx);
+  return rc;
+}
+
+static void fts3StartNode(Blob *pNode, int iHeight, sqlite3_int64 iChild){
+  pNode->a[0] = (char)iHeight;
+  if( iChild ){
+    assert( pNode->nAlloc>=1+sqlite3Fts3VarintLen(iChild) );
+    pNode->n = 1 + sqlite3Fts3PutVarint(&pNode->a[1], iChild);
+  }else{
+    assert( pNode->nAlloc>=1 );
+    pNode->n = 1;
+  }
+}
+
+/*
+** The first two arguments are a pointer to and the size of a segment b-tree
+** node. The node may be a leaf or an internal node.
+**
+** This function creates a new node image in blob object *pNew by copying
+** all terms that are greater than or equal to zTerm/nTerm (for leaf nodes)
+** or greater than zTerm/nTerm (for internal nodes) from aNode/nNode.
+*/
+static int fts3TruncateNode(
+  const char *aNode,              /* Current node image */
+  int nNode,                      /* Size of aNode in bytes */
+  Blob *pNew,                     /* OUT: Write new node image here */
+  const char *zTerm,              /* Omit all terms smaller than this */
+  int nTerm,                      /* Size of zTerm in bytes */
+  sqlite3_int64 *piBlock          /* OUT: Block number in next layer down */
+){
+  NodeReader reader;              /* Reader object */
+  Blob prev = {0, 0, 0};          /* Previous term written to new node */
+  int rc = SQLITE_OK;             /* Return code */
+  int bLeaf = aNode[0]=='\0';     /* True for a leaf node */
+
+  /* Allocate required output space */
+  blobGrowBuffer(pNew, nNode, &rc);
+  if( rc!=SQLITE_OK ) return rc;
+  pNew->n = 0;
+
+  /* Populate new node buffer */
+  for(rc = nodeReaderInit(&reader, aNode, nNode); 
+      rc==SQLITE_OK && reader.aNode; 
+      rc = nodeReaderNext(&reader)
+  ){
+    if( pNew->n==0 ){
+      int res = fts3TermCmp(reader.term.a, reader.term.n, zTerm, nTerm);
+      if( res<0 || (bLeaf==0 && res==0) ) continue;
+      fts3StartNode(pNew, (int)aNode[0], reader.iChild);
+      *piBlock = reader.iChild;
+    }
+    rc = fts3AppendToNode(
+        pNew, &prev, reader.term.a, reader.term.n,
+        reader.aDoclist, reader.nDoclist
+    );
+    if( rc!=SQLITE_OK ) break;
+  }
+  if( pNew->n==0 ){
+    fts3StartNode(pNew, (int)aNode[0], reader.iChild);
+    *piBlock = reader.iChild;
+  }
+  assert( pNew->n<=pNew->nAlloc );
+
+  nodeReaderRelease(&reader);
+  sqlite3_free(prev.a);
+  return rc;
+}
+
+/*
+** Remove all terms smaller than zTerm/nTerm from segment iIdx in absolute 
+** level iAbsLevel. This may involve deleting entries from the %_segments
+** table, and modifying existing entries in both the %_segments and %_segdir
+** tables.
+**
+** SQLITE_OK is returned if the segment is updated successfully. Or an
+** SQLite error code otherwise.
+*/
+static int fts3TruncateSegment(
+  Fts3Table *p,                   /* FTS3 table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level of segment to modify */
+  int iIdx,                       /* Index within level of segment to modify */
+  const char *zTerm,              /* Remove terms smaller than this */
+  int nTerm                      /* Number of bytes in buffer zTerm */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Blob root = {0,0,0};            /* New root page image */
+  Blob block = {0,0,0};           /* Buffer used for any other block */
+  sqlite3_int64 iBlock = 0;       /* Block id */
+  sqlite3_int64 iNewStart = 0;    /* New value for iStartBlock */
+  sqlite3_int64 iOldStart = 0;    /* Old value for iStartBlock */
+  sqlite3_stmt *pFetch = 0;       /* Statement used to fetch segdir */
+
+  rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pFetch, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;                      /* sqlite3_reset() return code */
+    sqlite3_bind_int64(pFetch, 1, iAbsLevel);
+    sqlite3_bind_int(pFetch, 2, iIdx);
+    if( SQLITE_ROW==sqlite3_step(pFetch) ){
+      const char *aRoot = sqlite3_column_blob(pFetch, 4);
+      int nRoot = sqlite3_column_bytes(pFetch, 4);
+      iOldStart = sqlite3_column_int64(pFetch, 1);
+      rc = fts3TruncateNode(aRoot, nRoot, &root, zTerm, nTerm, &iBlock);
+    }
+    rc2 = sqlite3_reset(pFetch);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  while( rc==SQLITE_OK && iBlock ){
+    char *aBlock = 0;
+    int nBlock = 0;
+    iNewStart = iBlock;
+
+    rc = sqlite3Fts3ReadBlock(p, iBlock, &aBlock, &nBlock, 0);
+    if( rc==SQLITE_OK ){
+      rc = fts3TruncateNode(aBlock, nBlock, &block, zTerm, nTerm, &iBlock);
+    }
+    if( rc==SQLITE_OK ){
+      rc = fts3WriteSegment(p, iNewStart, block.a, block.n);
+    }
+    sqlite3_free(aBlock);
+  }
+
+  /* Variable iNewStart now contains the first valid leaf node. */
+  if( rc==SQLITE_OK && iNewStart ){
+    sqlite3_stmt *pDel = 0;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDel, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDel, 1, iOldStart);
+      sqlite3_bind_int64(pDel, 2, iNewStart-1);
+      sqlite3_step(pDel);
+      rc = sqlite3_reset(pDel);
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    sqlite3_stmt *pChomp = 0;
+    rc = fts3SqlStmt(p, SQL_CHOMP_SEGDIR, &pChomp, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pChomp, 1, iNewStart);
+      sqlite3_bind_blob(pChomp, 2, root.a, root.n, SQLITE_STATIC);
+      sqlite3_bind_int64(pChomp, 3, iAbsLevel);
+      sqlite3_bind_int(pChomp, 4, iIdx);
+      sqlite3_step(pChomp);
+      rc = sqlite3_reset(pChomp);
+    }
+  }
+
+  sqlite3_free(root.a);
+  sqlite3_free(block.a);
+  return rc;
+}
+
+/*
+** This function is called after an incrmental-merge operation has run to
+** merge (or partially merge) two or more segments from absolute level
+** iAbsLevel.
+**
+** Each input segment is either removed from the db completely (if all of
+** its data was copied to the output segment by the incrmerge operation)
+** or modified in place so that it no longer contains those entries that
+** have been duplicated in the output segment.
+*/
+static int fts3IncrmergeChomp(
+  Fts3Table *p,                   /* FTS table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level containing segments */
+  Fts3MultiSegReader *pCsr,       /* Chomp all segments opened by this cursor */
+  int *pnRem                      /* Number of segments not deleted */
+){
+  int i;
+  int nRem = 0;
+  int rc = SQLITE_OK;
+
+  for(i=pCsr->nSegment-1; i>=0 && rc==SQLITE_OK; i--){
+    Fts3SegReader *pSeg = 0;
+    int j;
+
+    /* Find the Fts3SegReader object with Fts3SegReader.iIdx==i. It is hiding
+    ** somewhere in the pCsr->apSegment[] array.  */
+    for(j=0; ALWAYS(j<pCsr->nSegment); j++){
+      pSeg = pCsr->apSegment[j];
+      if( pSeg->iIdx==i ) break;
+    }
+    assert( j<pCsr->nSegment && pSeg->iIdx==i );
+
+    if( pSeg->aNode==0 ){
+      /* Seg-reader is at EOF. Remove the entire input segment. */
+      rc = fts3DeleteSegment(p, pSeg);
+      if( rc==SQLITE_OK ){
+        rc = fts3RemoveSegdirEntry(p, iAbsLevel, pSeg->iIdx);
+      }
+      *pnRem = 0;
+    }else{
+      /* The incremental merge did not copy all the data from this 
+      ** segment to the upper level. The segment is modified in place
+      ** so that it contains no keys smaller than zTerm/nTerm. */ 
+      const char *zTerm = pSeg->zTerm;
+      int nTerm = pSeg->nTerm;
+      rc = fts3TruncateSegment(p, iAbsLevel, pSeg->iIdx, zTerm, nTerm);
+      nRem++;
+    }
+  }
+
+  if( rc==SQLITE_OK && nRem!=pCsr->nSegment ){
+    rc = fts3RepackSegdirLevel(p, iAbsLevel);
+  }
+
+  *pnRem = nRem;
+  return rc;
+}
+
+/*
+** Store an incr-merge hint in the database.
+*/
+static int fts3IncrmergeHintStore(Fts3Table *p, Blob *pHint){
+  sqlite3_stmt *pReplace = 0;
+  int rc;                         /* Return code */
+
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pReplace, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_int(pReplace, 1, FTS_STAT_INCRMERGEHINT);
+    sqlite3_bind_blob(pReplace, 2, pHint->a, pHint->n, SQLITE_STATIC);
+    sqlite3_step(pReplace);
+    rc = sqlite3_reset(pReplace);
+  }
+
+  return rc;
+}
+
+/*
+** Load an incr-merge hint from the database. The incr-merge hint, if one 
+** exists, is stored in the rowid==1 row of the %_stat table.
+**
+** If successful, populate blob *pHint with the value read from the %_stat
+** table and return SQLITE_OK. Otherwise, if an error occurs, return an
+** SQLite error code.
+*/
+static int fts3IncrmergeHintLoad(Fts3Table *p, Blob *pHint){
+  sqlite3_stmt *pSelect = 0;
+  int rc;
+
+  pHint->n = 0;
+  rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pSelect, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pSelect, 1, FTS_STAT_INCRMERGEHINT);
+    if( SQLITE_ROW==sqlite3_step(pSelect) ){
+      const char *aHint = sqlite3_column_blob(pSelect, 0);
+      int nHint = sqlite3_column_bytes(pSelect, 0);
+      if( aHint ){
+        blobGrowBuffer(pHint, nHint, &rc);
+        if( rc==SQLITE_OK ){
+          memcpy(pHint->a, aHint, nHint);
+          pHint->n = nHint;
+        }
+      }
+    }
+    rc2 = sqlite3_reset(pSelect);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  return rc;
+}
+
+/*
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, append an entry to the hint stored in blob *pHint. Each entry
+** consists of two varints, the absolute level number of the input segments 
+** and the number of input segments.
+**
+** If successful, leave *pRc set to SQLITE_OK and return. If an error occurs,
+** set *pRc to an SQLite error code before returning.
+*/
+static void fts3IncrmergeHintPush(
+  Blob *pHint,                    /* Hint blob to append to */
+  i64 iAbsLevel,                  /* First varint to store in hint */
+  int nInput,                     /* Second varint to store in hint */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  blobGrowBuffer(pHint, pHint->n + 2*FTS3_VARINT_MAX, pRc);
+  if( *pRc==SQLITE_OK ){
+    pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], iAbsLevel);
+    pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], (i64)nInput);
+  }
+}
+
+/*
+** Read the last entry (most recently pushed) from the hint blob *pHint
+** and then remove the entry. Write the two values read to *piAbsLevel and 
+** *pnInput before returning.
+**
+** If no error occurs, return SQLITE_OK. If the hint blob in *pHint does
+** not contain at least two valid varints, return SQLITE_CORRUPT_VTAB.
+*/
+static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){
+  const int nHint = pHint->n;
+  int i;
+
+  i = pHint->n-2;
+  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;
+  while( i>0 && (pHint->a[i-1] & 0x80) ) i--;
+
+  pHint->n = i;
+  i += sqlite3Fts3GetVarint(&pHint->a[i], piAbsLevel);
+  i += fts3GetVarint32(&pHint->a[i], pnInput);
+  if( i!=nHint ) return FTS_CORRUPT_VTAB;
+
+  return SQLITE_OK;
+}
+
+
+/*
+** Attempt an incremental merge that writes nMerge leaf blocks.
+**
+** Incremental merges happen nMin segments at a time. The segments 
+** to be merged are the nMin oldest segments (the ones with the smallest 
+** values for the _segdir.idx field) in the highest level that contains 
+** at least nMin segments. Multiple merges might occur in an attempt to 
+** write the quota of nMerge leaf blocks.
+*/
+SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
+  int rc;                         /* Return code */
+  int nRem = nMerge;              /* Number of leaf pages yet to  be written */
+  Fts3MultiSegReader *pCsr;       /* Cursor used to read input data */
+  Fts3SegFilter *pFilter;         /* Filter used with cursor pCsr */
+  IncrmergeWriter *pWriter;       /* Writer object */
+  int nSeg = 0;                   /* Number of input segments */
+  sqlite3_int64 iAbsLevel = 0;    /* Absolute level number to work on */
+  Blob hint = {0, 0, 0};          /* Hint read from %_stat table */
+  int bDirtyHint = 0;             /* True if blob 'hint' has been modified */
+
+  /* Allocate space for the cursor, filter and writer objects */
+  const int nAlloc = sizeof(*pCsr) + sizeof(*pFilter) + sizeof(*pWriter);
+  pWriter = (IncrmergeWriter *)sqlite3_malloc(nAlloc);
+  if( !pWriter ) return SQLITE_NOMEM;
+  pFilter = (Fts3SegFilter *)&pWriter[1];
+  pCsr = (Fts3MultiSegReader *)&pFilter[1];
+
+  rc = fts3IncrmergeHintLoad(p, &hint);
+  while( rc==SQLITE_OK && nRem>0 ){
+    const i64 nMod = FTS3_SEGDIR_MAXLEVEL * p->nIndex;
+    sqlite3_stmt *pFindLevel = 0; /* SQL used to determine iAbsLevel */
+    int bUseHint = 0;             /* True if attempting to append */
+    int iIdx = 0;                 /* Largest idx in level (iAbsLevel+1) */
+
+    /* Search the %_segdir table for the absolute level with the smallest
+    ** relative level number that contains at least nMin segments, if any.
+    ** If one is found, set iAbsLevel to the absolute level number and
+    ** nSeg to nMin. If no level with at least nMin segments can be found, 
+    ** set nSeg to -1.
+    */
+    rc = fts3SqlStmt(p, SQL_FIND_MERGE_LEVEL, &pFindLevel, 0);
+    sqlite3_bind_int(pFindLevel, 1, MAX(2, nMin));
+    if( sqlite3_step(pFindLevel)==SQLITE_ROW ){
+      iAbsLevel = sqlite3_column_int64(pFindLevel, 0);
+      nSeg = sqlite3_column_int(pFindLevel, 1);
+      assert( nSeg>=2 );
+    }else{
+      nSeg = -1;
+    }
+    rc = sqlite3_reset(pFindLevel);
+
+    /* If the hint read from the %_stat table is not empty, check if the
+    ** last entry in it specifies a relative level smaller than or equal
+    ** to the level identified by the block above (if any). If so, this 
+    ** iteration of the loop will work on merging at the hinted level.
+    */
+    if( rc==SQLITE_OK && hint.n ){
+      int nHint = hint.n;
+      sqlite3_int64 iHintAbsLevel = 0;      /* Hint level */
+      int nHintSeg = 0;                     /* Hint number of segments */
+
+      rc = fts3IncrmergeHintPop(&hint, &iHintAbsLevel, &nHintSeg);
+      if( nSeg<0 || (iAbsLevel % nMod) >= (iHintAbsLevel % nMod) ){
+        iAbsLevel = iHintAbsLevel;
+        nSeg = nHintSeg;
+        bUseHint = 1;
+        bDirtyHint = 1;
+      }else{
+        /* This undoes the effect of the HintPop() above - so that no entry
+        ** is removed from the hint blob.  */
+        hint.n = nHint;
+      }
+    }
+
+    /* If nSeg is less that zero, then there is no level with at least
+    ** nMin segments and no hint in the %_stat table. No work to do.
+    ** Exit early in this case.  */
+    if( nSeg<0 ) break;
+
+    /* Open a cursor to iterate through the contents of the oldest nSeg 
+    ** indexes of absolute level iAbsLevel. If this cursor is opened using 
+    ** the 'hint' parameters, it is possible that there are less than nSeg
+    ** segments available in level iAbsLevel. In this case, no work is
+    ** done on iAbsLevel - fall through to the next iteration of the loop 
+    ** to start work on some other level.  */
+    memset(pWriter, 0, nAlloc);
+    pFilter->flags = FTS3_SEGMENT_REQUIRE_POS;
+
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);
+      assert( bUseHint==1 || bUseHint==0 );
+      if( iIdx==0 || (bUseHint && iIdx==1) ){
+        int bIgnore = 0;
+        rc = fts3SegmentIsMaxLevel(p, iAbsLevel+1, &bIgnore);
+        if( bIgnore ){
+          pFilter->flags |= FTS3_SEGMENT_IGNORE_EMPTY;
+        }
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergeCsr(p, iAbsLevel, nSeg, pCsr);
+    }
+    if( SQLITE_OK==rc && pCsr->nSegment==nSeg
+     && SQLITE_OK==(rc = sqlite3Fts3SegReaderStart(p, pCsr, pFilter))
+     && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pCsr))
+    ){
+      if( bUseHint && iIdx>0 ){
+        const char *zKey = pCsr->zTerm;
+        int nKey = pCsr->nTerm;
+        rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);
+      }else{
+        rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);
+      }
+
+      if( rc==SQLITE_OK && pWriter->nLeafEst ){
+        fts3LogMerge(nSeg, iAbsLevel);
+        do {
+          rc = fts3IncrmergeAppend(p, pWriter, pCsr);
+          if( rc==SQLITE_OK ) rc = sqlite3Fts3SegReaderStep(p, pCsr);
+          if( pWriter->nWork>=nRem && rc==SQLITE_ROW ) rc = SQLITE_OK;
+        }while( rc==SQLITE_ROW );
+
+        /* Update or delete the input segments */
+        if( rc==SQLITE_OK ){
+          nRem -= (1 + pWriter->nWork);
+          rc = fts3IncrmergeChomp(p, iAbsLevel, pCsr, &nSeg);
+          if( nSeg!=0 ){
+            bDirtyHint = 1;
+            fts3IncrmergeHintPush(&hint, iAbsLevel, nSeg, &rc);
+          }
+        }
+      }
+
+      if( nSeg!=0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
+      fts3IncrmergeRelease(p, pWriter, &rc);
+      if( nSeg==0 && pWriter->bNoLeafData==0 ){
+        fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);
+      }
+    }
+
+    sqlite3Fts3SegReaderFinish(pCsr);
+  }
+
+  /* Write the hint values into the %_stat table for the next incr-merger */
+  if( bDirtyHint && rc==SQLITE_OK ){
+    rc = fts3IncrmergeHintStore(p, &hint);
+  }
+
+  sqlite3_free(pWriter);
+  sqlite3_free(hint.a);
+  return rc;
+}
+
+/*
+** Convert the text beginning at *pz into an integer and return
+** its value.  Advance *pz to point to the first character past
+** the integer.
+*/
+static int fts3Getint(const char **pz){
+  const char *z = *pz;
+  int i = 0;
+  while( (*z)>='0' && (*z)<='9' ) i = 10*i + *(z++) - '0';
+  *pz = z;
+  return i;
+}
+
+/*
+** Process statements of the form:
+**
+**    INSERT INTO table(table) VALUES('merge=A,B');
+**
+** A and B are integers that decode to be the number of leaf pages
+** written for the merge, and the minimum number of segments on a level
+** before it will be selected for a merge, respectively.
+*/
+static int fts3DoIncrmerge(
+  Fts3Table *p,                   /* FTS3 table handle */
+  const char *zParam              /* Nul-terminated string containing "A,B" */
+){
+  int rc;
+  int nMin = (FTS3_MERGE_COUNT / 2);
+  int nMerge = 0;
+  const char *z = zParam;
+
+  /* Read the first integer value */
+  nMerge = fts3Getint(&z);
+
+  /* If the first integer value is followed by a ',',  read the second
+  ** integer value. */
+  if( z[0]==',' && z[1]!='\0' ){
+    z++;
+    nMin = fts3Getint(&z);
+  }
+
+  if( z[0]!='\0' || nMin<2 ){
+    rc = SQLITE_ERROR;
+  }else{
+    rc = SQLITE_OK;
+    if( !p->bHasStat ){
+      assert( p->bFts4==0 );
+      sqlite3Fts3CreateStatTable(&rc, p);
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts3Incrmerge(p, nMerge, nMin);
+    }
+    sqlite3Fts3SegmentsClose(p);
+  }
+  return rc;
+}
+
+/*
+** Process statements of the form:
+**
+**    INSERT INTO table(table) VALUES('automerge=X');
+**
+** where X is an integer.  X==0 means to turn automerge off.  X!=0 means
+** turn it on.  The setting is persistent.
+*/
+static int fts3DoAutoincrmerge(
+  Fts3Table *p,                   /* FTS3 table handle */
+  const char *zParam              /* Nul-terminated string containing boolean */
+){
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pStmt = 0;
+  p->nAutoincrmerge = fts3Getint(&zParam);
+  if( p->nAutoincrmerge==1 || p->nAutoincrmerge>FTS3_MERGE_COUNT ){
+    p->nAutoincrmerge = 8;
+  }
+  if( !p->bHasStat ){
+    assert( p->bFts4==0 );
+    sqlite3Fts3CreateStatTable(&rc, p);
+    if( rc ) return rc;
+  }
+  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
+  if( rc ) return rc;
+  sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
+  sqlite3_bind_int(pStmt, 2, p->nAutoincrmerge);
+  sqlite3_step(pStmt);
+  rc = sqlite3_reset(pStmt);
+  return rc;
+}
+
+/*
+** Return a 64-bit checksum for the FTS index entry specified by the
+** arguments to this function.
+*/
+static u64 fts3ChecksumEntry(
+  const char *zTerm,              /* Pointer to buffer containing term */
+  int nTerm,                      /* Size of zTerm in bytes */
+  int iLangid,                    /* Language id for current row */
+  int iIndex,                     /* Index (0..Fts3Table.nIndex-1) */
+  i64 iDocid,                     /* Docid for current row. */
+  int iCol,                       /* Column number */
+  int iPos                        /* Position */
+){
+  int i;
+  u64 ret = (u64)iDocid;
+
+  ret += (ret<<3) + iLangid;
+  ret += (ret<<3) + iIndex;
+  ret += (ret<<3) + iCol;
+  ret += (ret<<3) + iPos;
+  for(i=0; i<nTerm; i++) ret += (ret<<3) + zTerm[i];
+
+  return ret;
+}
+
+/*
+** Return a checksum of all entries in the FTS index that correspond to
+** language id iLangid. The checksum is calculated by XORing the checksums
+** of each individual entry (see fts3ChecksumEntry()) together.
+**
+** If successful, the checksum value is returned and *pRc set to SQLITE_OK.
+** Otherwise, if an error occurs, *pRc is set to an SQLite error code. The
+** return value is undefined in this case.
+*/
+static u64 fts3ChecksumIndex(
+  Fts3Table *p,                   /* FTS3 table handle */
+  int iLangid,                    /* Language id to return cksum for */
+  int iIndex,                     /* Index to cksum (0..p->nIndex-1) */
+  int *pRc                        /* OUT: Return code */
+){
+  Fts3SegFilter filter;
+  Fts3MultiSegReader csr;
+  int rc;
+  u64 cksum = 0;
+
+  assert( *pRc==SQLITE_OK );
+
+  memset(&filter, 0, sizeof(filter));
+  memset(&csr, 0, sizeof(csr));
+  filter.flags =  FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
+  filter.flags |= FTS3_SEGMENT_SCAN;
+
+  rc = sqlite3Fts3SegReaderCursor(
+      p, iLangid, iIndex, FTS3_SEGCURSOR_ALL, 0, 0, 0, 1,&csr
+  );
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);
+  }
+
+  if( rc==SQLITE_OK ){
+    while( SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, &csr)) ){
+      char *pCsr = csr.aDoclist;
+      char *pEnd = &pCsr[csr.nDoclist];
+
+      i64 iDocid = 0;
+      i64 iCol = 0;
+      i64 iPos = 0;
+
+      pCsr += sqlite3Fts3GetVarint(pCsr, &iDocid);
+      while( pCsr<pEnd ){
+        i64 iVal = 0;
+        pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
+        if( pCsr<pEnd ){
+          if( iVal==0 || iVal==1 ){
+            iCol = 0;
+            iPos = 0;
+            if( iVal ){
+              pCsr += sqlite3Fts3GetVarint(pCsr, &iCol);
+            }else{
+              pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
+              iDocid += iVal;
+            }
+          }else{
+            iPos += (iVal - 2);
+            cksum = cksum ^ fts3ChecksumEntry(
+                csr.zTerm, csr.nTerm, iLangid, iIndex, iDocid,
+                (int)iCol, (int)iPos
+            );
+          }
+        }
+      }
+    }
+  }
+  sqlite3Fts3SegReaderFinish(&csr);
+
+  *pRc = rc;
+  return cksum;
+}
+
+/*
+** Check if the contents of the FTS index match the current contents of the
+** content table. If no error occurs and the contents do match, set *pbOk
+** to true and return SQLITE_OK. Or if the contents do not match, set *pbOk
+** to false before returning.
+**
+** If an error occurs (e.g. an OOM or IO error), return an SQLite error 
+** code. The final value of *pbOk is undefined in this case.
+*/
+static int fts3IntegrityCheck(Fts3Table *p, int *pbOk){
+  int rc = SQLITE_OK;             /* Return code */
+  u64 cksum1 = 0;                 /* Checksum based on FTS index contents */
+  u64 cksum2 = 0;                 /* Checksum based on %_content contents */
+  sqlite3_stmt *pAllLangid = 0;   /* Statement to return all language-ids */
+
+  /* This block calculates the checksum according to the FTS index. */
+  rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);
+    sqlite3_bind_int(pAllLangid, 2, p->nIndex);
+    while( rc==SQLITE_OK && sqlite3_step(pAllLangid)==SQLITE_ROW ){
+      int iLangid = sqlite3_column_int(pAllLangid, 0);
+      int i;
+      for(i=0; i<p->nIndex; i++){
+        cksum1 = cksum1 ^ fts3ChecksumIndex(p, iLangid, i, &rc);
+      }
+    }
+    rc2 = sqlite3_reset(pAllLangid);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  /* This block calculates the checksum according to the %_content table */
+  if( rc==SQLITE_OK ){
+    sqlite3_tokenizer_module const *pModule = p->pTokenizer->pModule;
+    sqlite3_stmt *pStmt = 0;
+    char *zSql;
+   
+    zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist);
+    if( !zSql ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      sqlite3_free(zSql);
+    }
+
+    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      i64 iDocid = sqlite3_column_int64(pStmt, 0);
+      int iLang = langidFromSelect(p, pStmt);
+      int iCol;
+
+      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
+          int nText = sqlite3_column_bytes(pStmt, iCol+1);
+          sqlite3_tokenizer_cursor *pT = 0;
+
+          rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);
+          while( rc==SQLITE_OK ){
+            char const *zToken;       /* Buffer containing token */
+            int nToken = 0;           /* Number of bytes in token */
+            int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+            int iPos = 0;             /* Position of token in zText */
+
+            rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+            if( rc==SQLITE_OK ){
+              int i;
+              cksum2 = cksum2 ^ fts3ChecksumEntry(
+                  zToken, nToken, iLang, 0, iDocid, iCol, iPos
+              );
+              for(i=1; i<p->nIndex; i++){
+                if( p->aIndex[i].nPrefix<=nToken ){
+                  cksum2 = cksum2 ^ fts3ChecksumEntry(
+                      zToken, p->aIndex[i].nPrefix, iLang, i, iDocid, iCol, iPos
+                  );
+                }
+              }
+            }
+          }
+          if( pT ) pModule->xClose(pT);
+          if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+        }
+      }
+    }
+
+    sqlite3_finalize(pStmt);
+  }
+
+  *pbOk = (cksum1==cksum2);
+  return rc;
+}
+
+/*
+** Run the integrity-check. If no error occurs and the current contents of
+** the FTS index are correct, return SQLITE_OK. Or, if the contents of the
+** FTS index are incorrect, return SQLITE_CORRUPT_VTAB.
+**
+** Or, if an error (e.g. an OOM or IO error) occurs, return an SQLite 
+** error code.
+**
+** The integrity-check works as follows. For each token and indexed token
+** prefix in the document set, a 64-bit checksum is calculated (by code
+** in fts3ChecksumEntry()) based on the following:
+**
+**     + The index number (0 for the main index, 1 for the first prefix
+**       index etc.),
+**     + The token (or token prefix) text itself, 
+**     + The language-id of the row it appears in,
+**     + The docid of the row it appears in,
+**     + The column it appears in, and
+**     + The tokens position within that column.
+**
+** The checksums for all entries in the index are XORed together to create
+** a single checksum for the entire index.
+**
+** The integrity-check code calculates the same checksum in two ways:
+**
+**     1. By scanning the contents of the FTS index, and 
+**     2. By scanning and tokenizing the content table.
+**
+** If the two checksums are identical, the integrity-check is deemed to have
+** passed.
+*/
+static int fts3DoIntegrityCheck(
+  Fts3Table *p                    /* FTS3 table handle */
+){
+  int rc;
+  int bOk = 0;
+  rc = fts3IntegrityCheck(p, &bOk);
+  if( rc==SQLITE_OK && bOk==0 ) rc = FTS_CORRUPT_VTAB;
+  return rc;
+}
+
 /*
 ** Handle a 'special' INSERT of the form:
 **
@@ -125981,6 +157101,12 @@ static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
     rc = fts3DoOptimize(p, 0);
   }else if( nVal==7 && 0==sqlite3_strnicmp(zVal, "rebuild", 7) ){
     rc = fts3DoRebuild(p);
+  }else if( nVal==15 && 0==sqlite3_strnicmp(zVal, "integrity-check", 15) ){
+    rc = fts3DoIntegrityCheck(p);
+  }else if( nVal>6 && 0==sqlite3_strnicmp(zVal, "merge=", 6) ){
+    rc = fts3DoIncrmerge(p, &zVal[6]);
+  }else if( nVal>10 && 0==sqlite3_strnicmp(zVal, "automerge=", 10) ){
+    rc = fts3DoAutoincrmerge(p, &zVal[10]);
 #ifdef SQLITE_TEST
   }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
     p->nNodeSize = atoi(&zVal[9]);
@@ -125988,6 +157114,9 @@ static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
   }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
     p->nMaxPendingData = atoi(&zVal[11]);
     rc = SQLITE_OK;
+  }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){
+    p->bNoIncrDoclist = atoi(&zVal[21]);
+    rc = SQLITE_OK;
 #endif
   }else{
     rc = SQLITE_ERROR;
@@ -125996,6 +157125,7 @@ static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
   return rc;
 }
 
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
 /*
 ** Delete all cached deferred doclists. Deferred doclists are cached
 ** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function.
@@ -126046,33 +157176,34 @@ SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){
     iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
   
     for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
-      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
-      sqlite3_tokenizer_cursor *pTC = 0;
-  
-      rc = pModule->xOpen(pT, zText, -1, &pTC);
-      while( rc==SQLITE_OK ){
-        char const *zToken;       /* Buffer containing token */
-        int nToken;               /* Number of bytes in token */
-        int iDum1, iDum2;         /* Dummy variables */
-        int iPos;                 /* Position of token in zText */
-  
-        pTC->pTokenizer = pT;
-        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
-        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
-          Fts3PhraseToken *pPT = pDef->pToken;
-          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
-           && (pPT->bFirst==0 || iPos==0)
-           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
-           && (0==memcmp(zToken, pPT->z, pPT->n))
-          ){
-            fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+      if( p->abNotindexed[i]==0 ){
+        const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
+        sqlite3_tokenizer_cursor *pTC = 0;
+
+        rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
+        while( rc==SQLITE_OK ){
+          char const *zToken;       /* Buffer containing token */
+          int nToken = 0;           /* Number of bytes in token */
+          int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+          int iPos = 0;             /* Position of token in zText */
+
+          rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+          for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
+            Fts3PhraseToken *pPT = pDef->pToken;
+            if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
+                && (pPT->bFirst==0 || iPos==0)
+                && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
+                && (0==memcmp(zToken, pPT->z, pPT->n))
+              ){
+              fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+            }
           }
         }
+        if( pTC ) pModule->xClose(pTC);
+        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
       }
-      if( pTC ) pModule->xClose(pTC);
-      if( rc==SQLITE_DONE ) rc = SQLITE_OK;
     }
-  
+
     for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
       if( pDef->pList ){
         rc = fts3PendingListAppendVarint(&pDef->pList, 0);
@@ -126134,6 +157265,7 @@ SQLITE_PRIVATE int sqlite3Fts3DeferToken(
 
   return SQLITE_OK;
 }
+#endif
 
 /*
 ** SQLite value pRowid contains the rowid of a row that may or may not be
@@ -126143,30 +157275,32 @@ SQLITE_PRIVATE int sqlite3Fts3DeferToken(
 static int fts3DeleteByRowid(
   Fts3Table *p, 
   sqlite3_value *pRowid, 
-  int *pnDoc,
+  int *pnChng,                    /* IN/OUT: Decrement if row is deleted */
   u32 *aSzDel
 ){
-  int isEmpty = 0;
-  int rc = fts3IsEmpty(p, pRowid, &isEmpty);
-  if( rc==SQLITE_OK ){
-    if( isEmpty ){
-      /* Deleting this row means the whole table is empty. In this case
-      ** delete the contents of all three tables and throw away any
-      ** data in the pendingTerms hash table.  */
-      rc = fts3DeleteAll(p, 1);
-      *pnDoc = *pnDoc - 1;
-    }else{
-      sqlite3_int64 iRemove = sqlite3_value_int64(pRowid);
-      rc = fts3PendingTermsDocid(p, iRemove);
-      fts3DeleteTerms(&rc, p, pRowid, aSzDel);
-      if( p->zContentTbl==0 ){
-        fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
-        if( sqlite3_changes(p->db) ) *pnDoc = *pnDoc - 1;
+  int rc = SQLITE_OK;             /* Return code */
+  int bFound = 0;                 /* True if *pRowid really is in the table */
+
+  fts3DeleteTerms(&rc, p, pRowid, aSzDel, &bFound);
+  if( bFound && rc==SQLITE_OK ){
+    int isEmpty = 0;              /* Deleting *pRowid leaves the table empty */
+    rc = fts3IsEmpty(p, pRowid, &isEmpty);
+    if( rc==SQLITE_OK ){
+      if( isEmpty ){
+        /* Deleting this row means the whole table is empty. In this case
+        ** delete the contents of all three tables and throw away any
+        ** data in the pendingTerms hash table.  */
+        rc = fts3DeleteAll(p, 1);
+        *pnChng = 0;
+        memset(aSzDel, 0, sizeof(u32) * (p->nColumn+1) * 2);
       }else{
-        *pnDoc = *pnDoc - 1;
-      }
-      if( p->bHasDocsize ){
-        fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);
+        *pnChng = *pnChng - 1;
+        if( p->zContentTbl==0 ){
+          fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
+        }
+        if( p->bHasDocsize ){
+          fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);
+        }
       }
     }
   }
@@ -126176,7 +157310,16 @@ static int fts3DeleteByRowid(
 
 /*
 ** This function does the work for the xUpdate method of FTS3 virtual
-** tables.
+** tables. The schema of the virtual table being:
+**
+**     CREATE TABLE <table name>( 
+**       <user columns>,
+**       <table name> HIDDEN, 
+**       docid HIDDEN, 
+**       <langid> HIDDEN
+**     );
+**
+** 
 */
 SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
   sqlite3_vtab *pVtab,            /* FTS3 vtab object */
@@ -126188,11 +157331,19 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
   int rc = SQLITE_OK;             /* Return Code */
   int isRemove = 0;               /* True for an UPDATE or DELETE */
   u32 *aSzIns = 0;                /* Sizes of inserted documents */
-  u32 *aSzDel;                    /* Sizes of deleted documents */
+  u32 *aSzDel = 0;                /* Sizes of deleted documents */
   int nChng = 0;                  /* Net change in number of documents */
   int bInsertDone = 0;
 
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  assert( p->bHasStat==0 || p->bHasStat==1 );
+
   assert( p->pSegments==0 );
+  assert( 
+      nArg==1                     /* DELETE operations */
+   || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */
+  );
 
   /* Check for a "special" INSERT operation. One of the form:
   **
@@ -126206,14 +157357,22 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
     goto update_out;
   }
 
+  if( nArg>1 && sqlite3_value_int(apVal[2 + p->nColumn + 2])<0 ){
+    rc = SQLITE_CONSTRAINT;
+    goto update_out;
+  }
+
   /* Allocate space to hold the change in document sizes */
-  aSzIns = sqlite3_malloc( sizeof(aSzIns[0])*(p->nColumn+1)*2 );
-  if( aSzIns==0 ){
+  aSzDel = sqlite3_malloc( sizeof(aSzDel[0])*(p->nColumn+1)*2 );
+  if( aSzDel==0 ){
     rc = SQLITE_NOMEM;
     goto update_out;
   }
-  aSzDel = &aSzIns[p->nColumn+1];
-  memset(aSzIns, 0, sizeof(aSzIns[0])*(p->nColumn+1)*2);
+  aSzIns = &aSzDel[p->nColumn+1];
+  memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);
+
+  rc = fts3Writelock(p);
+  if( rc!=SQLITE_OK ) goto update_out;
 
   /* If this is an INSERT operation, or an UPDATE that modifies the rowid
   ** value, then this operation requires constraint handling.
@@ -126273,6 +157432,7 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
   
   /* If this is an INSERT or UPDATE operation, insert the new record. */
   if( nArg>1 && rc==SQLITE_OK ){
+    int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);
     if( bInsertDone==0 ){
       rc = fts3InsertData(p, apVal, pRowid);
       if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
@@ -126280,11 +157440,11 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
       }
     }
     if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
-      rc = fts3PendingTermsDocid(p, *pRowid);
+      rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);
     }
     if( rc==SQLITE_OK ){
       assert( p->iPrevDocid==*pRowid );
-      rc = fts3InsertTerms(p, apVal, aSzIns);
+      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
     }
     if( p->bHasDocsize ){
       fts3InsertDocsize(&rc, p, aSzIns);
@@ -126292,12 +157452,12 @@ SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(
     nChng++;
   }
 
-  if( p->bHasStat ){
+  if( p->bFts4 ){
     fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng);
   }
 
  update_out:
-  sqlite3_free(aSzIns);
+  sqlite3_free(aSzDel);
   sqlite3Fts3SegmentsClose(p);
   return rc;
 }
@@ -126341,6 +157501,7 @@ SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *p){
 ******************************************************************************
 */
 
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 
 /* #include <string.h> */
@@ -126356,6 +157517,8 @@ SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *p){
 #define FTS3_MATCHINFO_LENGTH    'l'        /* nCol values */
 #define FTS3_MATCHINFO_LCS       's'        /* nCol values */
 #define FTS3_MATCHINFO_HITS      'x'        /* 3*nCol*nPhrase values */
+#define FTS3_MATCHINFO_LHITS     'y'        /* nCol*nPhrase values */
+#define FTS3_MATCHINFO_LHITS_BM  'b'        /* nCol*nPhrase values */
 
 /*
 ** The default value for the second argument to matchinfo(). 
@@ -126417,9 +157580,22 @@ struct MatchInfo {
   int nCol;                       /* Number of columns in table */
   int nPhrase;                    /* Number of matchable phrases in query */
   sqlite3_int64 nDoc;             /* Number of docs in database */
+  char flag;
   u32 *aMatchinfo;                /* Pre-allocated buffer */
 };
 
+/*
+** An instance of this structure is used to manage a pair of buffers, each
+** (nElem * sizeof(u32)) bytes in size. See the MatchinfoBuffer code below
+** for details.
+*/
+struct MatchinfoBuffer {
+  u8 aRef[3];
+  int nElem;
+  int bGlobal;                    /* Set if global data is loaded */
+  char *zMatchinfo;
+  u32 aMatchinfo[1];
+};
 
 
 /*
@@ -126435,6 +157611,97 @@ struct StrBuffer {
 };
 
 
+/*************************************************************************
+** Start of MatchinfoBuffer code.
+*/
+
+/*
+** Allocate a two-slot MatchinfoBuffer object.
+*/
+static MatchinfoBuffer *fts3MIBufferNew(int nElem, const char *zMatchinfo){
+  MatchinfoBuffer *pRet;
+  int nByte = sizeof(u32) * (2*nElem + 1) + sizeof(MatchinfoBuffer);
+  int nStr = (int)strlen(zMatchinfo);
+
+  pRet = sqlite3_malloc(nByte + nStr+1);
+  if( pRet ){
+    memset(pRet, 0, nByte);
+    pRet->aMatchinfo[0] = (u8*)(&pRet->aMatchinfo[1]) - (u8*)pRet;
+    pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0] + sizeof(u32)*(nElem+1);
+    pRet->nElem = nElem;
+    pRet->zMatchinfo = ((char*)pRet) + nByte;
+    memcpy(pRet->zMatchinfo, zMatchinfo, nStr+1);
+    pRet->aRef[0] = 1;
+  }
+
+  return pRet;
+}
+
+static void fts3MIBufferFree(void *p){
+  MatchinfoBuffer *pBuf = (MatchinfoBuffer*)((u8*)p - ((u32*)p)[-1]);
+
+  assert( (u32*)p==&pBuf->aMatchinfo[1] 
+       || (u32*)p==&pBuf->aMatchinfo[pBuf->nElem+2] 
+  );
+  if( (u32*)p==&pBuf->aMatchinfo[1] ){
+    pBuf->aRef[1] = 0;
+  }else{
+    pBuf->aRef[2] = 0;
+  }
+
+  if( pBuf->aRef[0]==0 && pBuf->aRef[1]==0 && pBuf->aRef[2]==0 ){
+    sqlite3_free(pBuf);
+  }
+}
+
+static void (*fts3MIBufferAlloc(MatchinfoBuffer *p, u32 **paOut))(void*){
+  void (*xRet)(void*) = 0;
+  u32 *aOut = 0;
+
+  if( p->aRef[1]==0 ){
+    p->aRef[1] = 1;
+    aOut = &p->aMatchinfo[1];
+    xRet = fts3MIBufferFree;
+  }
+  else if( p->aRef[2]==0 ){
+    p->aRef[2] = 1;
+    aOut = &p->aMatchinfo[p->nElem+2];
+    xRet = fts3MIBufferFree;
+  }else{
+    aOut = (u32*)sqlite3_malloc(p->nElem * sizeof(u32));
+    if( aOut ){
+      xRet = sqlite3_free;
+      if( p->bGlobal ) memcpy(aOut, &p->aMatchinfo[1], p->nElem*sizeof(u32));
+    }
+  }
+
+  *paOut = aOut;
+  return xRet;
+}
+
+static void fts3MIBufferSetGlobal(MatchinfoBuffer *p){
+  p->bGlobal = 1;
+  memcpy(&p->aMatchinfo[2+p->nElem], &p->aMatchinfo[1], p->nElem*sizeof(u32));
+}
+
+/*
+** Free a MatchinfoBuffer object allocated using fts3MIBufferNew()
+*/
+SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p){
+  if( p ){
+    assert( p->aRef[0]==1 );
+    p->aRef[0] = 0;
+    if( p->aRef[0]==0 && p->aRef[1]==0 && p->aRef[2]==0 ){
+      sqlite3_free(p);
+    }
+  }
+}
+
+/* 
+** End of MatchinfoBuffer code.
+*************************************************************************/
+
+
 /*
 ** This function is used to help iterate through a position-list. A position
 ** list is a list of unique integers, sorted from smallest to largest. Each
@@ -126457,7 +157724,7 @@ struct StrBuffer {
 */
 static void fts3GetDeltaPosition(char **pp, int *piPos){
   int iVal;
-  *pp += sqlite3Fts3GetVarint32(*pp, &iVal);
+  *pp += fts3GetVarint32(*pp, &iVal);
   *piPos += (iVal-2);
 }
 
@@ -126471,7 +157738,7 @@ static int fts3ExprIterate2(
   void *pCtx                      /* Second argument to pass to callback */
 ){
   int rc;                         /* Return code */
-  int eType = pExpr->eType;       /* Type of expression node pExpr */
+  int eType = pExpr->eType;     /* Type of expression node pExpr */
 
   if( eType!=FTSQUERY_PHRASE ){
     assert( pExpr->pLeft && pExpr->pRight );
@@ -126505,6 +157772,7 @@ static int fts3ExprIterate(
   return fts3ExprIterate2(pExpr, &iPhrase, x, pCtx);
 }
 
+
 /*
 ** This is an fts3ExprIterate() callback used while loading the doclists
 ** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also
@@ -126549,8 +157817,7 @@ static int fts3ExprLoadDoclists(
 
 static int fts3ExprPhraseCountCb(Fts3Expr *pExpr, int iPhrase, void *ctx){
   (*(int *)ctx)++;
-  UNUSED_PARAMETER(pExpr);
-  UNUSED_PARAMETER(iPhrase);
+  pExpr->iPhrase = iPhrase;
   return SQLITE_OK;
 }
 static int fts3ExprPhraseCount(Fts3Expr *pExpr){
@@ -126689,10 +157956,11 @@ static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){
   SnippetIter *p = (SnippetIter *)ctx;
   SnippetPhrase *pPhrase = &p->aPhrase[iPhrase];
   char *pCsr;
+  int rc;
 
   pPhrase->nToken = pExpr->pPhrase->nToken;
-
-  pCsr = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol);
+  rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pCsr);
+  assert( rc==SQLITE_OK || pCsr==0 );
   if( pCsr ){
     int iFirst = 0;
     pPhrase->pList = pCsr;
@@ -126703,10 +157971,12 @@ static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){
     pPhrase->iHead = iFirst;
     pPhrase->iTail = iFirst;
   }else{
-    assert( pPhrase->pList==0 && pPhrase->pHead==0 && pPhrase->pTail==0 );
+    assert( rc!=SQLITE_OK || (
+       pPhrase->pList==0 && pPhrase->pHead==0 && pPhrase->pTail==0 
+    ));
   }
 
-  return SQLITE_OK;
+  return rc;
 }
 
 /*
@@ -126715,9 +157985,9 @@ static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){
 ** is the snippet with the highest score, where scores are calculated
 ** by adding:
 **
-**   (a) +1 point for each occurence of a matchable phrase in the snippet.
+**   (a) +1 point for each occurrence of a matchable phrase in the snippet.
 **
-**   (b) +1000 points for the first occurence of each matchable phrase in 
+**   (b) +1000 points for the first occurrence of each matchable phrase in 
 **       the snippet for which the corresponding mCovered bit is not set.
 **
 ** The selected snippet parameters are stored in structure *pFragment before
@@ -126768,37 +158038,39 @@ static int fts3BestSnippet(
   sIter.nSnippet = nSnippet;
   sIter.nPhrase = nList;
   sIter.iCurrent = -1;
-  (void)fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void *)&sIter);
+  rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void*)&sIter);
+  if( rc==SQLITE_OK ){
 
-  /* Set the *pmSeen output variable. */
-  for(i=0; i<nList; i++){
-    if( sIter.aPhrase[i].pHead ){
-      *pmSeen |= (u64)1 << i;
+    /* Set the *pmSeen output variable. */
+    for(i=0; i<nList; i++){
+      if( sIter.aPhrase[i].pHead ){
+        *pmSeen |= (u64)1 << i;
+      }
     }
-  }
 
-  /* Loop through all candidate snippets. Store the best snippet in 
-  ** *pFragment. Store its associated 'score' in iBestScore.
-  */
-  pFragment->iCol = iCol;
-  while( !fts3SnippetNextCandidate(&sIter) ){
-    int iPos;
-    int iScore;
-    u64 mCover;
-    u64 mHighlight;
-    fts3SnippetDetails(&sIter, mCovered, &iPos, &iScore, &mCover, &mHighlight);
-    assert( iScore>=0 );
-    if( iScore>iBestScore ){
-      pFragment->iPos = iPos;
-      pFragment->hlmask = mHighlight;
-      pFragment->covered = mCover;
-      iBestScore = iScore;
+    /* Loop through all candidate snippets. Store the best snippet in 
+     ** *pFragment. Store its associated 'score' in iBestScore.
+     */
+    pFragment->iCol = iCol;
+    while( !fts3SnippetNextCandidate(&sIter) ){
+      int iPos;
+      int iScore;
+      u64 mCover;
+      u64 mHighlite;
+      fts3SnippetDetails(&sIter, mCovered, &iPos, &iScore, &mCover,&mHighlite);
+      assert( iScore>=0 );
+      if( iScore>iBestScore ){
+        pFragment->iPos = iPos;
+        pFragment->hlmask = mHighlite;
+        pFragment->covered = mCover;
+        iBestScore = iScore;
+      }
     }
-  }
 
+    *piScore = iBestScore;
+  }
   sqlite3_free(sIter.aPhrase);
-  *piScore = iBestScore;
-  return SQLITE_OK;
+  return rc;
 }
 
 
@@ -126830,6 +158102,7 @@ static int fts3StringAppend(
     pStr->z = zNew;
     pStr->nAlloc = nAlloc;
   }
+  assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );
 
   /* Append the data to the string buffer. */
   memcpy(&pStr->z[pStr->n], zAppend, nAppend);
@@ -126861,6 +158134,7 @@ static int fts3StringAppend(
 */
 static int fts3SnippetShift(
   Fts3Table *pTab,                /* FTS3 table snippet comes from */
+  int iLangid,                    /* Language id to use in tokenizing */
   int nSnippet,                   /* Number of tokens desired for snippet */
   const char *zDoc,               /* Document text to extract snippet from */
   int nDoc,                       /* Size of buffer zDoc in bytes */
@@ -126896,13 +158170,12 @@ static int fts3SnippetShift(
       /* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)
       ** or more tokens in zDoc/nDoc.
       */
-      rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
+      rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, iLangid, zDoc, nDoc, &pC);
       if( rc!=SQLITE_OK ){
         return rc;
       }
-      pC->pTokenizer = pTab->pTokenizer;
       while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){
-        const char *ZDUMMY; int DUMMY1, DUMMY2, DUMMY3;
+        const char *ZDUMMY; int DUMMY1 = 0, DUMMY2 = 0, DUMMY3 = 0;
         rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);
       }
       pMod->xClose(pC);
@@ -126946,8 +158219,6 @@ static int fts3SnippetText(
   int iCol = pFragment->iCol+1;   /* Query column to extract text from */
   sqlite3_tokenizer_module *pMod; /* Tokenizer module methods object */
   sqlite3_tokenizer_cursor *pC;   /* Tokenizer cursor open on zDoc/nDoc */
-  const char *ZDUMMY;             /* Dummy argument used with tokenizer */
-  int DUMMY1;                     /* Dummy argument used with tokenizer */
   
   zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol);
   if( zDoc==0 ){
@@ -126960,17 +158231,29 @@ static int fts3SnippetText(
 
   /* Open a token cursor on the document. */
   pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;
-  rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
+  rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid, zDoc,nDoc,&pC);
   if( rc!=SQLITE_OK ){
     return rc;
   }
-  pC->pTokenizer = pTab->pTokenizer;
 
   while( rc==SQLITE_OK ){
-    int iBegin;                   /* Offset in zDoc of start of token */
-    int iFin;                     /* Offset in zDoc of end of token */
-    int isHighlight;              /* True for highlighted terms */
-
+    const char *ZDUMMY;           /* Dummy argument used with tokenizer */
+    int DUMMY1 = -1;              /* Dummy argument used with tokenizer */
+    int iBegin = 0;               /* Offset in zDoc of start of token */
+    int iFin = 0;                 /* Offset in zDoc of end of token */
+    int isHighlight = 0;          /* True for highlighted terms */
+
+    /* Variable DUMMY1 is initialized to a negative value above. Elsewhere
+    ** in the FTS code the variable that the third argument to xNext points to
+    ** is initialized to zero before the first (*but not necessarily
+    ** subsequent*) call to xNext(). This is done for a particular application
+    ** that needs to know whether or not the tokenizer is being used for
+    ** snippet generation or for some other purpose.
+    **
+    ** Extreme care is required when writing code to depend on this
+    ** initialization. It is not a documented part of the tokenizer interface.
+    ** If a tokenizer is used directly by any code outside of FTS, this
+    ** convention might not be respected.  */
     rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &iBegin, &iFin, &iCurrent);
     if( rc!=SQLITE_OK ){
       if( rc==SQLITE_DONE ){
@@ -126986,15 +158269,21 @@ static int fts3SnippetText(
 
     if( !isShiftDone ){
       int n = nDoc - iBegin;
-      rc = fts3SnippetShift(pTab, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask);
+      rc = fts3SnippetShift(
+          pTab, pCsr->iLangid, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask
+      );
       isShiftDone = 1;
 
       /* Now that the shift has been done, check if the initial "..." are
       ** required. They are required if (a) this is not the first fragment,
       ** or (b) this fragment does not begin at position 0 of its column. 
       */
-      if( rc==SQLITE_OK && (iPos>0 || iFragment>0) ){
-        rc = fts3StringAppend(pOut, zEllipsis, -1);
+      if( rc==SQLITE_OK ){
+        if( iPos>0 || iFragment>0 ){
+          rc = fts3StringAppend(pOut, zEllipsis, -1);
+        }else if( iBegin ){
+          rc = fts3StringAppend(pOut, zDoc, iBegin);
+        }
       }
       if( rc!=SQLITE_OK || iCurrent<iPos ) continue;
     }
@@ -127051,6 +158340,60 @@ static int fts3ColumnlistCount(char **ppCollist){
 }
 
 /*
+** This function gathers 'y' or 'b' data for a single phrase.
+*/
+static void fts3ExprLHits(
+  Fts3Expr *pExpr,                /* Phrase expression node */
+  MatchInfo *p                    /* Matchinfo context */
+){
+  Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;
+  int iStart;
+  Fts3Phrase *pPhrase = pExpr->pPhrase;
+  char *pIter = pPhrase->doclist.pList;
+  int iCol = 0;
+
+  assert( p->flag==FTS3_MATCHINFO_LHITS_BM || p->flag==FTS3_MATCHINFO_LHITS );
+  if( p->flag==FTS3_MATCHINFO_LHITS ){
+    iStart = pExpr->iPhrase * p->nCol;
+  }else{
+    iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);
+  }
+
+  while( 1 ){
+    int nHit = fts3ColumnlistCount(&pIter);
+    if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
+      if( p->flag==FTS3_MATCHINFO_LHITS ){
+        p->aMatchinfo[iStart + iCol] = (u32)nHit;
+      }else if( nHit ){
+        p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));
+      }
+    }
+    assert( *pIter==0x00 || *pIter==0x01 );
+    if( *pIter!=0x01 ) break;
+    pIter++;
+    pIter += fts3GetVarint32(pIter, &iCol);
+  }
+}
+
+/*
+** Gather the results for matchinfo directives 'y' and 'b'.
+*/
+static void fts3ExprLHitGather(
+  Fts3Expr *pExpr,
+  MatchInfo *p
+){
+  assert( (pExpr->pLeft==0)==(pExpr->pRight==0) );
+  if( pExpr->bEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){
+    if( pExpr->pLeft ){
+      fts3ExprLHitGather(pExpr->pLeft, p);
+      fts3ExprLHitGather(pExpr->pRight, p);
+    }else{
+      fts3ExprLHits(pExpr, p);
+    }
+  }
+}
+
+/*
 ** fts3ExprIterate() callback used to collect the "global" matchinfo stats
 ** for a single query. 
 **
@@ -127098,13 +158441,14 @@ static int fts3ExprLocalHitsCb(
   int iPhrase,                    /* Phrase number */
   void *pCtx                      /* Pointer to MatchInfo structure */
 ){
+  int rc = SQLITE_OK;
   MatchInfo *p = (MatchInfo *)pCtx;
   int iStart = iPhrase * p->nCol * 3;
   int i;
 
-  for(i=0; i<p->nCol; i++){
+  for(i=0; i<p->nCol && rc==SQLITE_OK; i++){
     char *pCsr;
-    pCsr = sqlite3Fts3EvalPhrasePoslist(p->pCursor, pExpr, i);
+    rc = sqlite3Fts3EvalPhrasePoslist(p->pCursor, pExpr, i, &pCsr);
     if( pCsr ){
       p->aMatchinfo[iStart+i*3] = fts3ColumnlistCount(&pCsr);
     }else{
@@ -127112,7 +158456,7 @@ static int fts3ExprLocalHitsCb(
     }
   }
 
-  return SQLITE_OK;
+  return rc;
 }
 
 static int fts3MatchinfoCheck(
@@ -127122,15 +158466,17 @@ static int fts3MatchinfoCheck(
 ){
   if( (cArg==FTS3_MATCHINFO_NPHRASE)
    || (cArg==FTS3_MATCHINFO_NCOL)
-   || (cArg==FTS3_MATCHINFO_NDOC && pTab->bHasStat)
-   || (cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bHasStat)
+   || (cArg==FTS3_MATCHINFO_NDOC && pTab->bFts4)
+   || (cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bFts4)
    || (cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize)
    || (cArg==FTS3_MATCHINFO_LCS)
    || (cArg==FTS3_MATCHINFO_HITS)
+   || (cArg==FTS3_MATCHINFO_LHITS)
+   || (cArg==FTS3_MATCHINFO_LHITS_BM)
   ){
     return SQLITE_OK;
   }
-  *pzErr = sqlite3_mprintf("unrecognized matchinfo request: %c", cArg);
+  sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);
   return SQLITE_ERROR;
 }
 
@@ -127150,6 +158496,14 @@ static int fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
       nVal = pInfo->nCol;
       break;
 
+    case FTS3_MATCHINFO_LHITS:
+      nVal = pInfo->nCol * pInfo->nPhrase;
+      break;
+
+    case FTS3_MATCHINFO_LHITS_BM:
+      nVal = pInfo->nPhrase * ((pInfo->nCol + 31) / 32);
+      break;
+
     default:
       assert( cArg==FTS3_MATCHINFO_HITS );
       nVal = pInfo->nCol * pInfo->nPhrase * 3;
@@ -127273,8 +158627,10 @@ static int fts3MatchinfoLcs(Fts3Cursor *pCsr, MatchInfo *pInfo){
     int nLive = 0;                /* Number of iterators in aIter not at EOF */
 
     for(i=0; i<pInfo->nPhrase; i++){
+      int rc;
       LcsIterator *pIt = &aIter[i];
-      pIt->pRead = sqlite3Fts3EvalPhrasePoslist(pCsr, pIt->pExpr, iCol);
+      rc = sqlite3Fts3EvalPhrasePoslist(pCsr, pIt->pExpr, iCol, &pIt->pRead);
+      if( rc!=SQLITE_OK ) return rc;
       if( pIt->pRead ){
         pIt->iPos = pIt->iPosOffset;
         fts3LcsIteratorAdvance(&aIter[i]);
@@ -127342,7 +158698,7 @@ static int fts3MatchinfoValues(
   sqlite3_stmt *pSelect = 0;
 
   for(i=0; rc==SQLITE_OK && zArg[i]; i++){
-
+    pInfo->flag = zArg[i];
     switch( zArg[i] ){
       case FTS3_MATCHINFO_NPHRASE:
         if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nPhrase;
@@ -127402,6 +158758,14 @@ static int fts3MatchinfoValues(
         }
         break;
 
+      case FTS3_MATCHINFO_LHITS_BM:
+      case FTS3_MATCHINFO_LHITS: {
+        int nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);
+        memset(pInfo->aMatchinfo, 0, nZero);
+        fts3ExprLHitGather(pCsr->pExpr, pInfo);
+        break;
+      }
+
       default: {
         Fts3Expr *pExpr;
         assert( zArg[i]==FTS3_MATCHINFO_HITS );
@@ -127414,6 +158778,7 @@ static int fts3MatchinfoValues(
             if( rc!=SQLITE_OK ) break;
           }
           rc = fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
+          sqlite3Fts3EvalTestDeferred(pCsr, &rc);
           if( rc!=SQLITE_OK ) break;
         }
         (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);
@@ -127433,7 +158798,8 @@ static int fts3MatchinfoValues(
 ** Populate pCsr->aMatchinfo[] with data for the current row. The 
 ** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).
 */
-static int fts3GetMatchinfo(
+static void fts3GetMatchinfo(
+  sqlite3_context *pCtx,        /* Return results here */
   Fts3Cursor *pCsr,               /* FTS3 Cursor object */
   const char *zArg                /* Second argument to matchinfo() function */
 ){
@@ -127442,6 +158808,9 @@ static int fts3GetMatchinfo(
   int rc = SQLITE_OK;
   int bGlobal = 0;                /* Collect 'global' stats as well as local */
 
+  u32 *aOut = 0;
+  void (*xDestroyOut)(void*) = 0;
+
   memset(&sInfo, 0, sizeof(MatchInfo));
   sInfo.pCursor = pCsr;
   sInfo.nCol = pTab->nColumn;
@@ -127449,21 +158818,18 @@ static int fts3GetMatchinfo(
   /* If there is cached matchinfo() data, but the format string for the 
   ** cache does not match the format string for this request, discard 
   ** the cached data. */
-  if( pCsr->zMatchinfo && strcmp(pCsr->zMatchinfo, zArg) ){
-    assert( pCsr->aMatchinfo );
-    sqlite3_free(pCsr->aMatchinfo);
-    pCsr->zMatchinfo = 0;
-    pCsr->aMatchinfo = 0;
+  if( pCsr->pMIBuffer && strcmp(pCsr->pMIBuffer->zMatchinfo, zArg) ){
+    sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
+    pCsr->pMIBuffer = 0;
   }
 
-  /* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
+  /* If Fts3Cursor.pMIBuffer is NULL, then this is the first time the
   ** matchinfo function has been called for this query. In this case 
   ** allocate the array used to accumulate the matchinfo data and
   ** initialize those elements that are constant for every row.
   */
-  if( pCsr->aMatchinfo==0 ){
+  if( pCsr->pMIBuffer==0 ){
     int nMatchinfo = 0;           /* Number of u32 elements in match-info */
-    int nArg;                     /* Bytes in zArg */
     int i;                        /* Used to iterate through zArg */
 
     /* Determine the number of phrases in the query */
@@ -127472,30 +158838,46 @@ static int fts3GetMatchinfo(
 
     /* Determine the number of integers in the buffer returned by this call. */
     for(i=0; zArg[i]; i++){
+      char *zErr = 0;
+      if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
+        sqlite3_result_error(pCtx, zErr, -1);
+        sqlite3_free(zErr);
+        return;
+      }
       nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);
     }
 
     /* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */
-    nArg = (int)strlen(zArg);
-    pCsr->aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo + nArg + 1);
-    if( !pCsr->aMatchinfo ) return SQLITE_NOMEM;
-
-    pCsr->zMatchinfo = (char *)&pCsr->aMatchinfo[nMatchinfo];
-    pCsr->nMatchinfo = nMatchinfo;
-    memcpy(pCsr->zMatchinfo, zArg, nArg+1);
-    memset(pCsr->aMatchinfo, 0, sizeof(u32)*nMatchinfo);
+    pCsr->pMIBuffer = fts3MIBufferNew(nMatchinfo, zArg);
+    if( !pCsr->pMIBuffer ) rc = SQLITE_NOMEM;
+
     pCsr->isMatchinfoNeeded = 1;
     bGlobal = 1;
   }
 
-  sInfo.aMatchinfo = pCsr->aMatchinfo;
-  sInfo.nPhrase = pCsr->nPhrase;
-  if( pCsr->isMatchinfoNeeded ){
+  if( rc==SQLITE_OK ){
+    xDestroyOut = fts3MIBufferAlloc(pCsr->pMIBuffer, &aOut);
+    if( xDestroyOut==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    sInfo.aMatchinfo = aOut;
+    sInfo.nPhrase = pCsr->nPhrase;
     rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);
-    pCsr->isMatchinfoNeeded = 0;
+    if( bGlobal ){
+      fts3MIBufferSetGlobal(pCsr->pMIBuffer);
+    }
   }
 
-  return rc;
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx, rc);
+    if( xDestroyOut ) xDestroyOut(aOut);
+  }else{
+    int n = pCsr->pMIBuffer->nElem * sizeof(u32);
+    sqlite3_result_blob(pCtx, aOut, n, xDestroyOut);
+  }
 }
 
 /*
@@ -127557,7 +158939,7 @@ SQLITE_PRIVATE void sqlite3Fts3Snippet(
       */
       for(iRead=0; iRead<pTab->nColumn; iRead++){
         SnippetFragment sF = {0, 0, 0, 0};
-        int iS;
+        int iS = 0;
         if( iCol>=0 && iRead!=iCol ) continue;
 
         /* Find the best snippet of nFToken tokens in column iRead. */
@@ -127626,9 +159008,10 @@ static int fts3ExprTermOffsetInit(Fts3Expr *pExpr, int iPhrase, void *ctx){
   int iTerm;                      /* For looping through nTerm phrase terms */
   char *pList;                    /* Pointer to position list for phrase */
   int iPos = 0;                   /* First position in position-list */
+  int rc;
 
   UNUSED_PARAMETER(iPhrase);
-  pList = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol);
+  rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pList);
   nTerm = pExpr->pPhrase->nToken;
   if( pList ){
     fts3GetDeltaPosition(&pList, &iPos);
@@ -127642,7 +159025,7 @@ static int fts3ExprTermOffsetInit(Fts3Expr *pExpr, int iPhrase, void *ctx){
     pT->iPos = iPos;
   }
 
-  return SQLITE_OK;
+  return rc;
 }
 
 /*
@@ -127654,8 +159037,6 @@ SQLITE_PRIVATE void sqlite3Fts3Offsets(
 ){
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
   sqlite3_tokenizer_module const *pMod = pTab->pTokenizer->pModule;
-  const char *ZDUMMY;             /* Dummy argument used with xNext() */
-  int NDUMMY;                     /* Dummy argument used with xNext() */
   int rc;                         /* Return Code */
   int nToken;                     /* Number of tokens in query */
   int iCol;                       /* Column currently being processed */
@@ -127688,9 +159069,11 @@ SQLITE_PRIVATE void sqlite3Fts3Offsets(
   */
   for(iCol=0; iCol<pTab->nColumn; iCol++){
     sqlite3_tokenizer_cursor *pC; /* Tokenizer cursor */
-    int iStart;
-    int iEnd;
-    int iCurrent;
+    const char *ZDUMMY;           /* Dummy argument used with xNext() */
+    int NDUMMY = 0;               /* Dummy argument used with xNext() */
+    int iStart = 0;
+    int iEnd = 0;
+    int iCurrent = 0;
     const char *zDoc;
     int nDoc;
 
@@ -127700,7 +159083,7 @@ SQLITE_PRIVATE void sqlite3Fts3Offsets(
     */
     sCtx.iCol = iCol;
     sCtx.iTerm = 0;
-    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void *)&sCtx);
+    (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void*)&sCtx);
 
     /* Retreive the text stored in column iCol. If an SQL NULL is stored 
     ** in column iCol, jump immediately to the next iteration of the loop.
@@ -127719,9 +159102,10 @@ SQLITE_PRIVATE void sqlite3Fts3Offsets(
     }
 
     /* Initialize a tokenizer iterator to iterate through column iCol. */
-    rc = pMod->xOpen(pTab->pTokenizer, zDoc, nDoc, &pC);
+    rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid,
+        zDoc, nDoc, &pC
+    );
     if( rc!=SQLITE_OK ) goto offsets_out;
-    pC->pTokenizer = pTab->pTokenizer;
 
     rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);
     while( rc==SQLITE_OK ){
@@ -127791,19 +159175,9 @@ SQLITE_PRIVATE void sqlite3Fts3Matchinfo(
   const char *zArg                /* Second arg to matchinfo() function */
 ){
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
-  int rc;
-  int i;
   const char *zFormat;
 
   if( zArg ){
-    for(i=0; zArg[i]; i++){
-      char *zErr = 0;
-      if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
-        sqlite3_result_error(pContext, zErr, -1);
-        sqlite3_free(zErr);
-        return;
-      }
-    }
     zFormat = zArg;
   }else{
     zFormat = FTS3_MATCHINFO_DEFAULT;
@@ -127812,23 +159186,780 @@ SQLITE_PRIVATE void sqlite3Fts3Matchinfo(
   if( !pCsr->pExpr ){
     sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
     return;
+  }else{
+    /* Retrieve matchinfo() data. */
+    fts3GetMatchinfo(pContext, pCsr, zFormat);
+    sqlite3Fts3SegmentsClose(pTab);
   }
+}
 
-  /* Retrieve matchinfo() data. */
-  rc = fts3GetMatchinfo(pCsr, zFormat);
-  sqlite3Fts3SegmentsClose(pTab);
+#endif
+
+/************** End of fts3_snippet.c ****************************************/
+/************** Begin file fts3_unicode.c ************************************/
+/*
+** 2012 May 24
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Implementation of the "unicode" full-text-search tokenizer.
+*/
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+
+/* #include "fts3Int.h" */
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+/* #include <assert.h> */
+/* #include <stdlib.h> */
+/* #include <stdio.h> */
+/* #include <string.h> */
+
+/* #include "fts3_tokenizer.h" */
+
+/*
+** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied
+** from the sqlite3 source file utf.c. If this file is compiled as part
+** of the amalgamation, they are not required.
+*/
+#ifndef SQLITE_AMALGAMATION
+
+static const unsigned char sqlite3Utf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+
+#define READ_UTF8(zIn, zTerm, c)                           \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = sqlite3Utf8Trans1[c-0xc0];                         \
+    while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+    if( c<0x80                                             \
+        || (c&0xFFFFF800)==0xD800                          \
+        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
+  }
+
+#define WRITE_UTF8(zOut, c) {                          \
+  if( c<0x00080 ){                                     \
+    *zOut++ = (u8)(c&0xFF);                            \
+  }                                                    \
+  else if( c<0x00800 ){                                \
+    *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);                \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }                                                    \
+  else if( c<0x10000 ){                                \
+    *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);               \
+    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }else{                                               \
+    *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);             \
+    *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);             \
+    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
+    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
+  }                                                    \
+}
+
+#endif /* ifndef SQLITE_AMALGAMATION */
+
+typedef struct unicode_tokenizer unicode_tokenizer;
+typedef struct unicode_cursor unicode_cursor;
+
+struct unicode_tokenizer {
+  sqlite3_tokenizer base;
+  int bRemoveDiacritic;
+  int nException;
+  int *aiException;
+};
+
+struct unicode_cursor {
+  sqlite3_tokenizer_cursor base;
+  const unsigned char *aInput;    /* Input text being tokenized */
+  int nInput;                     /* Size of aInput[] in bytes */
+  int iOff;                       /* Current offset within aInput[] */
+  int iToken;                     /* Index of next token to be returned */
+  char *zToken;                   /* storage for current token */
+  int nAlloc;                     /* space allocated at zToken */
+};
+
+
+/*
+** Destroy a tokenizer allocated by unicodeCreate().
+*/
+static int unicodeDestroy(sqlite3_tokenizer *pTokenizer){
+  if( pTokenizer ){
+    unicode_tokenizer *p = (unicode_tokenizer *)pTokenizer;
+    sqlite3_free(p->aiException);
+    sqlite3_free(p);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** As part of a tokenchars= or separators= option, the CREATE VIRTUAL TABLE
+** statement has specified that the tokenizer for this table shall consider
+** all characters in string zIn/nIn to be separators (if bAlnum==0) or
+** token characters (if bAlnum==1).
+**
+** For each codepoint in the zIn/nIn string, this function checks if the
+** sqlite3FtsUnicodeIsalnum() function already returns the desired result.
+** If so, no action is taken. Otherwise, the codepoint is added to the 
+** unicode_tokenizer.aiException[] array. For the purposes of tokenization,
+** the return value of sqlite3FtsUnicodeIsalnum() is inverted for all
+** codepoints in the aiException[] array.
+**
+** If a standalone diacritic mark (one that sqlite3FtsUnicodeIsdiacritic()
+** identifies as a diacritic) occurs in the zIn/nIn string it is ignored.
+** It is not possible to change the behavior of the tokenizer with respect
+** to these codepoints.
+*/
+static int unicodeAddExceptions(
+  unicode_tokenizer *p,           /* Tokenizer to add exceptions to */
+  int bAlnum,                     /* Replace Isalnum() return value with this */
+  const char *zIn,                /* Array of characters to make exceptions */
+  int nIn                         /* Length of z in bytes */
+){
+  const unsigned char *z = (const unsigned char *)zIn;
+  const unsigned char *zTerm = &z[nIn];
+  int iCode;
+  int nEntry = 0;
+
+  assert( bAlnum==0 || bAlnum==1 );
+
+  while( z<zTerm ){
+    READ_UTF8(z, zTerm, iCode);
+    assert( (sqlite3FtsUnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
+    if( sqlite3FtsUnicodeIsalnum(iCode)!=bAlnum 
+     && sqlite3FtsUnicodeIsdiacritic(iCode)==0 
+    ){
+      nEntry++;
+    }
+  }
+
+  if( nEntry ){
+    int *aNew;                    /* New aiException[] array */
+    int nNew;                     /* Number of valid entries in array aNew[] */
+
+    aNew = sqlite3_realloc(p->aiException, (p->nException+nEntry)*sizeof(int));
+    if( aNew==0 ) return SQLITE_NOMEM;
+    nNew = p->nException;
+
+    z = (const unsigned char *)zIn;
+    while( z<zTerm ){
+      READ_UTF8(z, zTerm, iCode);
+      if( sqlite3FtsUnicodeIsalnum(iCode)!=bAlnum 
+       && sqlite3FtsUnicodeIsdiacritic(iCode)==0
+      ){
+        int i, j;
+        for(i=0; i<nNew && aNew[i]<iCode; i++);
+        for(j=nNew; j>i; j--) aNew[j] = aNew[j-1];
+        aNew[i] = iCode;
+        nNew++;
+      }
+    }
+    p->aiException = aNew;
+    p->nException = nNew;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Return true if the p->aiException[] array contains the value iCode.
+*/
+static int unicodeIsException(unicode_tokenizer *p, int iCode){
+  if( p->nException>0 ){
+    int *a = p->aiException;
+    int iLo = 0;
+    int iHi = p->nException-1;
+
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( iCode==a[iTest] ){
+        return 1;
+      }else if( iCode>a[iTest] ){
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+  }
+
+  return 0;
+}
+
+/*
+** Return true if, for the purposes of tokenization, codepoint iCode is
+** considered a token character (not a separator).
+*/
+static int unicodeIsAlnum(unicode_tokenizer *p, int iCode){
+  assert( (sqlite3FtsUnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
+  return sqlite3FtsUnicodeIsalnum(iCode) ^ unicodeIsException(p, iCode);
+}
+
+/*
+** Create a new tokenizer instance.
+*/
+static int unicodeCreate(
+  int nArg,                       /* Size of array argv[] */
+  const char * const *azArg,      /* Tokenizer creation arguments */
+  sqlite3_tokenizer **pp          /* OUT: New tokenizer handle */
+){
+  unicode_tokenizer *pNew;        /* New tokenizer object */
+  int i;
+  int rc = SQLITE_OK;
+
+  pNew = (unicode_tokenizer *) sqlite3_malloc(sizeof(unicode_tokenizer));
+  if( pNew==NULL ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(unicode_tokenizer));
+  pNew->bRemoveDiacritic = 1;
+
+  for(i=0; rc==SQLITE_OK && i<nArg; i++){
+    const char *z = azArg[i];
+    int n = (int)strlen(z);
+
+    if( n==19 && memcmp("remove_diacritics=1", z, 19)==0 ){
+      pNew->bRemoveDiacritic = 1;
+    }
+    else if( n==19 && memcmp("remove_diacritics=0", z, 19)==0 ){
+      pNew->bRemoveDiacritic = 0;
+    }
+    else if( n>=11 && memcmp("tokenchars=", z, 11)==0 ){
+      rc = unicodeAddExceptions(pNew, 1, &z[11], n-11);
+    }
+    else if( n>=11 && memcmp("separators=", z, 11)==0 ){
+      rc = unicodeAddExceptions(pNew, 0, &z[11], n-11);
+    }
+    else{
+      /* Unrecognized argument */
+      rc  = SQLITE_ERROR;
+    }
+  }
 
   if( rc!=SQLITE_OK ){
-    sqlite3_result_error_code(pContext, rc);
+    unicodeDestroy((sqlite3_tokenizer *)pNew);
+    pNew = 0;
+  }
+  *pp = (sqlite3_tokenizer *)pNew;
+  return rc;
+}
+
+/*
+** Prepare to begin tokenizing a particular string.  The input
+** string to be tokenized is pInput[0..nBytes-1].  A cursor
+** used to incrementally tokenize this string is returned in 
+** *ppCursor.
+*/
+static int unicodeOpen(
+  sqlite3_tokenizer *p,           /* The tokenizer */
+  const char *aInput,             /* Input string */
+  int nInput,                     /* Size of string aInput in bytes */
+  sqlite3_tokenizer_cursor **pp   /* OUT: New cursor object */
+){
+  unicode_cursor *pCsr;
+
+  pCsr = (unicode_cursor *)sqlite3_malloc(sizeof(unicode_cursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(unicode_cursor));
+
+  pCsr->aInput = (const unsigned char *)aInput;
+  if( aInput==0 ){
+    pCsr->nInput = 0;
+  }else if( nInput<0 ){
+    pCsr->nInput = (int)strlen(aInput);
   }else{
-    int n = pCsr->nMatchinfo * sizeof(u32);
-    sqlite3_result_blob(pContext, pCsr->aMatchinfo, n, SQLITE_TRANSIENT);
+    pCsr->nInput = nInput;
   }
+
+  *pp = &pCsr->base;
+  UNUSED_PARAMETER(p);
+  return SQLITE_OK;
 }
 
-#endif
+/*
+** Close a tokenization cursor previously opened by a call to
+** simpleOpen() above.
+*/
+static int unicodeClose(sqlite3_tokenizer_cursor *pCursor){
+  unicode_cursor *pCsr = (unicode_cursor *) pCursor;
+  sqlite3_free(pCsr->zToken);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
 
-/************** End of fts3_snippet.c ****************************************/
+/*
+** Extract the next token from a tokenization cursor.  The cursor must
+** have been opened by a prior call to simpleOpen().
+*/
+static int unicodeNext(
+  sqlite3_tokenizer_cursor *pC,   /* Cursor returned by simpleOpen */
+  const char **paToken,           /* OUT: Token text */
+  int *pnToken,                   /* OUT: Number of bytes at *paToken */
+  int *piStart,                   /* OUT: Starting offset of token */
+  int *piEnd,                     /* OUT: Ending offset of token */
+  int *piPos                      /* OUT: Position integer of token */
+){
+  unicode_cursor *pCsr = (unicode_cursor *)pC;
+  unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);
+  int iCode = 0;
+  char *zOut;
+  const unsigned char *z = &pCsr->aInput[pCsr->iOff];
+  const unsigned char *zStart = z;
+  const unsigned char *zEnd;
+  const unsigned char *zTerm = &pCsr->aInput[pCsr->nInput];
+
+  /* Scan past any delimiter characters before the start of the next token.
+  ** Return SQLITE_DONE early if this takes us all the way to the end of 
+  ** the input.  */
+  while( z<zTerm ){
+    READ_UTF8(z, zTerm, iCode);
+    if( unicodeIsAlnum(p, iCode) ) break;
+    zStart = z;
+  }
+  if( zStart>=zTerm ) return SQLITE_DONE;
+
+  zOut = pCsr->zToken;
+  do {
+    int iOut;
+
+    /* Grow the output buffer if required. */
+    if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){
+      char *zNew = sqlite3_realloc(pCsr->zToken, pCsr->nAlloc+64);
+      if( !zNew ) return SQLITE_NOMEM;
+      zOut = &zNew[zOut - pCsr->zToken];
+      pCsr->zToken = zNew;
+      pCsr->nAlloc += 64;
+    }
+
+    /* Write the folded case of the last character read to the output */
+    zEnd = z;
+    iOut = sqlite3FtsUnicodeFold(iCode, p->bRemoveDiacritic);
+    if( iOut ){
+      WRITE_UTF8(zOut, iOut);
+    }
+
+    /* If the cursor is not at EOF, read the next character */
+    if( z>=zTerm ) break;
+    READ_UTF8(z, zTerm, iCode);
+  }while( unicodeIsAlnum(p, iCode) 
+       || sqlite3FtsUnicodeIsdiacritic(iCode)
+  );
+
+  /* Set the output variables and return. */
+  pCsr->iOff = (int)(z - pCsr->aInput);
+  *paToken = pCsr->zToken;
+  *pnToken = (int)(zOut - pCsr->zToken);
+  *piStart = (int)(zStart - pCsr->aInput);
+  *piEnd = (int)(zEnd - pCsr->aInput);
+  *piPos = pCsr->iToken++;
+  return SQLITE_OK;
+}
+
+/*
+** Set *ppModule to a pointer to the sqlite3_tokenizer_module 
+** structure for the unicode tokenizer.
+*/
+SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const **ppModule){
+  static const sqlite3_tokenizer_module module = {
+    0,
+    unicodeCreate,
+    unicodeDestroy,
+    unicodeOpen,
+    unicodeClose,
+    unicodeNext,
+    0,
+  };
+  *ppModule = &module;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
+#endif /* ifndef SQLITE_DISABLE_FTS3_UNICODE */
+
+/************** End of fts3_unicode.c ****************************************/
+/************** Begin file fts3_unicode2.c ***********************************/
+/*
+** 2012 May 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+/*
+** DO NOT EDIT THIS MACHINE GENERATED FILE.
+*/
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
+
+/* #include <assert.h> */
+
+/*
+** Return true if the argument corresponds to a unicode codepoint
+** classified as either a letter or a number. Otherwise false.
+**
+** The results are undefined if the value passed to this function
+** is less than zero.
+*/
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int c){
+  /* Each unsigned integer in the following array corresponds to a contiguous
+  ** range of unicode codepoints that are not either letters or numbers (i.e.
+  ** codepoints for which this function should return 0).
+  **
+  ** The most significant 22 bits in each 32-bit value contain the first 
+  ** codepoint in the range. The least significant 10 bits are used to store
+  ** the size of the range (always at least 1). In other words, the value 
+  ** ((C<<22) + N) represents a range of N codepoints starting with codepoint 
+  ** C. It is not possible to represent a range larger than 1023 codepoints 
+  ** using this format.
+  */
+  static const unsigned int aEntry[] = {
+    0x00000030, 0x0000E807, 0x00016C06, 0x0001EC2F, 0x0002AC07,
+    0x0002D001, 0x0002D803, 0x0002EC01, 0x0002FC01, 0x00035C01,
+    0x0003DC01, 0x000B0804, 0x000B480E, 0x000B9407, 0x000BB401,
+    0x000BBC81, 0x000DD401, 0x000DF801, 0x000E1002, 0x000E1C01,
+    0x000FD801, 0x00120808, 0x00156806, 0x00162402, 0x00163C01,
+    0x00164437, 0x0017CC02, 0x00180005, 0x00181816, 0x00187802,
+    0x00192C15, 0x0019A804, 0x0019C001, 0x001B5001, 0x001B580F,
+    0x001B9C07, 0x001BF402, 0x001C000E, 0x001C3C01, 0x001C4401,
+    0x001CC01B, 0x001E980B, 0x001FAC09, 0x001FD804, 0x00205804,
+    0x00206C09, 0x00209403, 0x0020A405, 0x0020C00F, 0x00216403,
+    0x00217801, 0x0023901B, 0x00240004, 0x0024E803, 0x0024F812,
+    0x00254407, 0x00258804, 0x0025C001, 0x00260403, 0x0026F001,
+    0x0026F807, 0x00271C02, 0x00272C03, 0x00275C01, 0x00278802,
+    0x0027C802, 0x0027E802, 0x00280403, 0x0028F001, 0x0028F805,
+    0x00291C02, 0x00292C03, 0x00294401, 0x0029C002, 0x0029D401,
+    0x002A0403, 0x002AF001, 0x002AF808, 0x002B1C03, 0x002B2C03,
+    0x002B8802, 0x002BC002, 0x002C0403, 0x002CF001, 0x002CF807,
+    0x002D1C02, 0x002D2C03, 0x002D5802, 0x002D8802, 0x002DC001,
+    0x002E0801, 0x002EF805, 0x002F1803, 0x002F2804, 0x002F5C01,
+    0x002FCC08, 0x00300403, 0x0030F807, 0x00311803, 0x00312804,
+    0x00315402, 0x00318802, 0x0031FC01, 0x00320802, 0x0032F001,
+    0x0032F807, 0x00331803, 0x00332804, 0x00335402, 0x00338802,
+    0x00340802, 0x0034F807, 0x00351803, 0x00352804, 0x00355C01,
+    0x00358802, 0x0035E401, 0x00360802, 0x00372801, 0x00373C06,
+    0x00375801, 0x00376008, 0x0037C803, 0x0038C401, 0x0038D007,
+    0x0038FC01, 0x00391C09, 0x00396802, 0x003AC401, 0x003AD006,
+    0x003AEC02, 0x003B2006, 0x003C041F, 0x003CD00C, 0x003DC417,
+    0x003E340B, 0x003E6424, 0x003EF80F, 0x003F380D, 0x0040AC14,
+    0x00412806, 0x00415804, 0x00417803, 0x00418803, 0x00419C07,
+    0x0041C404, 0x0042080C, 0x00423C01, 0x00426806, 0x0043EC01,
+    0x004D740C, 0x004E400A, 0x00500001, 0x0059B402, 0x005A0001,
+    0x005A6C02, 0x005BAC03, 0x005C4803, 0x005CC805, 0x005D4802,
+    0x005DC802, 0x005ED023, 0x005F6004, 0x005F7401, 0x0060000F,
+    0x0062A401, 0x0064800C, 0x0064C00C, 0x00650001, 0x00651002,
+    0x0066C011, 0x00672002, 0x00677822, 0x00685C05, 0x00687802,
+    0x0069540A, 0x0069801D, 0x0069FC01, 0x006A8007, 0x006AA006,
+    0x006C0005, 0x006CD011, 0x006D6823, 0x006E0003, 0x006E840D,
+    0x006F980E, 0x006FF004, 0x00709014, 0x0070EC05, 0x0071F802,
+    0x00730008, 0x00734019, 0x0073B401, 0x0073C803, 0x00770027,
+    0x0077F004, 0x007EF401, 0x007EFC03, 0x007F3403, 0x007F7403,
+    0x007FB403, 0x007FF402, 0x00800065, 0x0081A806, 0x0081E805,
+    0x00822805, 0x0082801A, 0x00834021, 0x00840002, 0x00840C04,
+    0x00842002, 0x00845001, 0x00845803, 0x00847806, 0x00849401,
+    0x00849C01, 0x0084A401, 0x0084B801, 0x0084E802, 0x00850005,
+    0x00852804, 0x00853C01, 0x00864264, 0x00900027, 0x0091000B,
+    0x0092704E, 0x00940200, 0x009C0475, 0x009E53B9, 0x00AD400A,
+    0x00B39406, 0x00B3BC03, 0x00B3E404, 0x00B3F802, 0x00B5C001,
+    0x00B5FC01, 0x00B7804F, 0x00B8C00C, 0x00BA001A, 0x00BA6C59,
+    0x00BC00D6, 0x00BFC00C, 0x00C00005, 0x00C02019, 0x00C0A807,
+    0x00C0D802, 0x00C0F403, 0x00C26404, 0x00C28001, 0x00C3EC01,
+    0x00C64002, 0x00C6580A, 0x00C70024, 0x00C8001F, 0x00C8A81E,
+    0x00C94001, 0x00C98020, 0x00CA2827, 0x00CB003F, 0x00CC0100,
+    0x01370040, 0x02924037, 0x0293F802, 0x02983403, 0x0299BC10,
+    0x029A7C01, 0x029BC008, 0x029C0017, 0x029C8002, 0x029E2402,
+    0x02A00801, 0x02A01801, 0x02A02C01, 0x02A08C09, 0x02A0D804,
+    0x02A1D004, 0x02A20002, 0x02A2D011, 0x02A33802, 0x02A38012,
+    0x02A3E003, 0x02A4980A, 0x02A51C0D, 0x02A57C01, 0x02A60004,
+    0x02A6CC1B, 0x02A77802, 0x02A8A40E, 0x02A90C01, 0x02A93002,
+    0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,
+    0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,
+    0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,
+    0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,
+    0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,
+    0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,
+    0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,
+    0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,
+    0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,
+    0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,
+    0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,
+    0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,
+    0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,
+    0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,
+    0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,
+    0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,
+    0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,
+    0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,
+    0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,
+    0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,
+    0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,
+    0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,
+    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
+    0x380400F0,
+  };
+  static const unsigned int aAscii[4] = {
+    0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
+  };
+
+  if( c<128 ){
+    return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
+  }else if( c<(1<<22) ){
+    unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
+    int iRes = 0;
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( key >= aEntry[iTest] ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+    assert( aEntry[0]<key );
+    assert( key>=aEntry[iRes] );
+    return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
+  }
+  return 1;
+}
+
+
+/*
+** If the argument is a codepoint corresponding to a lowercase letter
+** in the ASCII range with a diacritic added, return the codepoint
+** of the ASCII letter only. For example, if passed 235 - "LATIN
+** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER
+** E"). The resuls of passing a codepoint that corresponds to an
+** uppercase letter are undefined.
+*/
+static int remove_diacritic(int c){
+  unsigned short aDia[] = {
+        0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 
+     2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 
+     2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 
+     2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 
+     3456,  3696,  3712,  3728,  3744,  3896,  3912,  3928, 
+     3968,  4008,  4040,  4106,  4138,  4170,  4202,  4234, 
+     4266,  4296,  4312,  4344,  4408,  4424,  4472,  4504, 
+     6148,  6198,  6264,  6280,  6360,  6429,  6505,  6529, 
+    61448, 61468, 61534, 61592, 61642, 61688, 61704, 61726, 
+    61784, 61800, 61836, 61880, 61914, 61948, 61998, 62122, 
+    62154, 62200, 62218, 62302, 62364, 62442, 62478, 62536, 
+    62554, 62584, 62604, 62640, 62648, 62656, 62664, 62730, 
+    62924, 63050, 63082, 63274, 63390, 
+  };
+  char aChar[] = {
+    '\0', 'a',  'c',  'e',  'i',  'n',  'o',  'u',  'y',  'y',  'a',  'c',  
+    'd',  'e',  'e',  'g',  'h',  'i',  'j',  'k',  'l',  'n',  'o',  'r',  
+    's',  't',  'u',  'u',  'w',  'y',  'z',  'o',  'u',  'a',  'i',  'o',  
+    'u',  'g',  'k',  'o',  'j',  'g',  'n',  'a',  'e',  'i',  'o',  'r',  
+    'u',  's',  't',  'h',  'a',  'e',  'o',  'y',  '\0', '\0', '\0', '\0', 
+    '\0', '\0', '\0', '\0', 'a',  'b',  'd',  'd',  'e',  'f',  'g',  'h',  
+    'h',  'i',  'k',  'l',  'l',  'm',  'n',  'p',  'r',  'r',  's',  't',  
+    'u',  'v',  'w',  'w',  'x',  'y',  'z',  'h',  't',  'w',  'y',  'a',  
+    'e',  'i',  'o',  'u',  'y',  
+  };
+
+  unsigned int key = (((unsigned int)c)<<3) | 0x00000007;
+  int iRes = 0;
+  int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;
+  int iLo = 0;
+  while( iHi>=iLo ){
+    int iTest = (iHi + iLo) / 2;
+    if( key >= aDia[iTest] ){
+      iRes = iTest;
+      iLo = iTest+1;
+    }else{
+      iHi = iTest-1;
+    }
+  }
+  assert( key>=aDia[iRes] );
+  return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);
+}
+
+
+/*
+** Return true if the argument interpreted as a unicode codepoint
+** is a diacritical modifier character.
+*/
+SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int c){
+  unsigned int mask0 = 0x08029FDF;
+  unsigned int mask1 = 0x000361F8;
+  if( c<768 || c>817 ) return 0;
+  return (c < 768+32) ?
+      (mask0 & (1 << (c-768))) :
+      (mask1 & (1 << (c-768-32)));
+}
+
+
+/*
+** Interpret the argument as a unicode codepoint. If the codepoint
+** is an upper case character that has a lower case equivalent,
+** return the codepoint corresponding to the lower case version.
+** Otherwise, return a copy of the argument.
+**
+** The results are undefined if the value passed to this function
+** is less than zero.
+*/
+SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int c, int bRemoveDiacritic){
+  /* Each entry in the following array defines a rule for folding a range
+  ** of codepoints to lower case. The rule applies to a range of nRange
+  ** codepoints starting at codepoint iCode.
+  **
+  ** If the least significant bit in flags is clear, then the rule applies
+  ** to all nRange codepoints (i.e. all nRange codepoints are upper case and
+  ** need to be folded). Or, if it is set, then the rule only applies to
+  ** every second codepoint in the range, starting with codepoint C.
+  **
+  ** The 7 most significant bits in flags are an index into the aiOff[]
+  ** array. If a specific codepoint C does require folding, then its lower
+  ** case equivalent is ((C + aiOff[flags>>1]) & 0xFFFF).
+  **
+  ** The contents of this array are generated by parsing the CaseFolding.txt
+  ** file distributed as part of the "Unicode Character Database". See
+  ** http://www.unicode.org for details.
+  */
+  static const struct TableEntry {
+    unsigned short iCode;
+    unsigned char flags;
+    unsigned char nRange;
+  } aEntry[] = {
+    {65, 14, 26},          {181, 64, 1},          {192, 14, 23},
+    {216, 14, 7},          {256, 1, 48},          {306, 1, 6},
+    {313, 1, 16},          {330, 1, 46},          {376, 116, 1},
+    {377, 1, 6},           {383, 104, 1},         {385, 50, 1},
+    {386, 1, 4},           {390, 44, 1},          {391, 0, 1},
+    {393, 42, 2},          {395, 0, 1},           {398, 32, 1},
+    {399, 38, 1},          {400, 40, 1},          {401, 0, 1},
+    {403, 42, 1},          {404, 46, 1},          {406, 52, 1},
+    {407, 48, 1},          {408, 0, 1},           {412, 52, 1},
+    {413, 54, 1},          {415, 56, 1},          {416, 1, 6},
+    {422, 60, 1},          {423, 0, 1},           {425, 60, 1},
+    {428, 0, 1},           {430, 60, 1},          {431, 0, 1},
+    {433, 58, 2},          {435, 1, 4},           {439, 62, 1},
+    {440, 0, 1},           {444, 0, 1},           {452, 2, 1},
+    {453, 0, 1},           {455, 2, 1},           {456, 0, 1},
+    {458, 2, 1},           {459, 1, 18},          {478, 1, 18},
+    {497, 2, 1},           {498, 1, 4},           {502, 122, 1},
+    {503, 134, 1},         {504, 1, 40},          {544, 110, 1},
+    {546, 1, 18},          {570, 70, 1},          {571, 0, 1},
+    {573, 108, 1},         {574, 68, 1},          {577, 0, 1},
+    {579, 106, 1},         {580, 28, 1},          {581, 30, 1},
+    {582, 1, 10},          {837, 36, 1},          {880, 1, 4},
+    {886, 0, 1},           {902, 18, 1},          {904, 16, 3},
+    {908, 26, 1},          {910, 24, 2},          {913, 14, 17},
+    {931, 14, 9},          {962, 0, 1},           {975, 4, 1},
+    {976, 140, 1},         {977, 142, 1},         {981, 146, 1},
+    {982, 144, 1},         {984, 1, 24},          {1008, 136, 1},
+    {1009, 138, 1},        {1012, 130, 1},        {1013, 128, 1},
+    {1015, 0, 1},          {1017, 152, 1},        {1018, 0, 1},
+    {1021, 110, 3},        {1024, 34, 16},        {1040, 14, 32},
+    {1120, 1, 34},         {1162, 1, 54},         {1216, 6, 1},
+    {1217, 1, 14},         {1232, 1, 88},         {1329, 22, 38},
+    {4256, 66, 38},        {4295, 66, 1},         {4301, 66, 1},
+    {7680, 1, 150},        {7835, 132, 1},        {7838, 96, 1},
+    {7840, 1, 96},         {7944, 150, 8},        {7960, 150, 6},
+    {7976, 150, 8},        {7992, 150, 8},        {8008, 150, 6},
+    {8025, 151, 8},        {8040, 150, 8},        {8072, 150, 8},
+    {8088, 150, 8},        {8104, 150, 8},        {8120, 150, 2},
+    {8122, 126, 2},        {8124, 148, 1},        {8126, 100, 1},
+    {8136, 124, 4},        {8140, 148, 1},        {8152, 150, 2},
+    {8154, 120, 2},        {8168, 150, 2},        {8170, 118, 2},
+    {8172, 152, 1},        {8184, 112, 2},        {8186, 114, 2},
+    {8188, 148, 1},        {8486, 98, 1},         {8490, 92, 1},
+    {8491, 94, 1},         {8498, 12, 1},         {8544, 8, 16},
+    {8579, 0, 1},          {9398, 10, 26},        {11264, 22, 47},
+    {11360, 0, 1},         {11362, 88, 1},        {11363, 102, 1},
+    {11364, 90, 1},        {11367, 1, 6},         {11373, 84, 1},
+    {11374, 86, 1},        {11375, 80, 1},        {11376, 82, 1},
+    {11378, 0, 1},         {11381, 0, 1},         {11390, 78, 2},
+    {11392, 1, 100},       {11499, 1, 4},         {11506, 0, 1},
+    {42560, 1, 46},        {42624, 1, 24},        {42786, 1, 14},
+    {42802, 1, 62},        {42873, 1, 4},         {42877, 76, 1},
+    {42878, 1, 10},        {42891, 0, 1},         {42893, 74, 1},
+    {42896, 1, 4},         {42912, 1, 10},        {42922, 72, 1},
+    {65313, 14, 26},       
+  };
+  static const unsigned short aiOff[] = {
+   1,     2,     8,     15,    16,    26,    28,    32,    
+   37,    38,    40,    48,    63,    64,    69,    71,    
+   79,    80,    116,   202,   203,   205,   206,   207,   
+   209,   210,   211,   213,   214,   217,   218,   219,   
+   775,   7264,  10792, 10795, 23228, 23256, 30204, 54721, 
+   54753, 54754, 54756, 54787, 54793, 54809, 57153, 57274, 
+   57921, 58019, 58363, 61722, 65268, 65341, 65373, 65406, 
+   65408, 65410, 65415, 65424, 65436, 65439, 65450, 65462, 
+   65472, 65476, 65478, 65480, 65482, 65488, 65506, 65511, 
+   65514, 65521, 65527, 65528, 65529, 
+  };
+
+  int ret = c;
+
+  assert( c>=0 );
+  assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );
+
+  if( c<128 ){
+    if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');
+  }else if( c<65536 ){
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    int iRes = -1;
+
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      int cmp = (c - aEntry[iTest].iCode);
+      if( cmp>=0 ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+    assert( iRes<0 || c>=aEntry[iRes].iCode );
+
+    if( iRes>=0 ){
+      const struct TableEntry *p = &aEntry[iRes];
+      if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){
+        ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;
+        assert( ret>0 );
+      }
+    }
+
+    if( bRemoveDiacritic ) ret = remove_diacritic(ret);
+  }
+  
+  else if( c>=66560 && c<66600 ){
+    ret = c + 40;
+  }
+
+  return ret;
+}
+#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */
+#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */
+
+/************** End of fts3_unicode2.c ***************************************/
 /************** Begin file rtree.c *******************************************/
 /*
 ** 2001 September 15
@@ -127886,60 +160017,22 @@ SQLITE_PRIVATE void sqlite3Fts3Matchinfo(
 
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RTREE)
 
-/*
-** This file contains an implementation of a couple of different variants
-** of the r-tree algorithm. See the README file for further details. The 
-** same data-structure is used for all, but the algorithms for insert and
-** delete operations vary. The variants used are selected at compile time 
-** by defining the following symbols:
-*/
-
-/* Either, both or none of the following may be set to activate 
-** r*tree variant algorithms.
-*/
-#define VARIANT_RSTARTREE_CHOOSESUBTREE 0
-#define VARIANT_RSTARTREE_REINSERT      1
-
-/* 
-** Exactly one of the following must be set to 1.
-*/
-#define VARIANT_GUTTMAN_QUADRATIC_SPLIT 0
-#define VARIANT_GUTTMAN_LINEAR_SPLIT    0
-#define VARIANT_RSTARTREE_SPLIT         1
-
-#define VARIANT_GUTTMAN_SPLIT \
-        (VARIANT_GUTTMAN_LINEAR_SPLIT||VARIANT_GUTTMAN_QUADRATIC_SPLIT)
-
-#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
-  #define PickNext QuadraticPickNext
-  #define PickSeeds QuadraticPickSeeds
-  #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_GUTTMAN_LINEAR_SPLIT
-  #define PickNext LinearPickNext
-  #define PickSeeds LinearPickSeeds
-  #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_RSTARTREE_SPLIT
-  #define AssignCells splitNodeStartree
-#endif
-
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
-# define NDEBUG 1
-#endif
-
 #ifndef SQLITE_CORE
+/*   #include "sqlite3ext.h" */
   SQLITE_EXTENSION_INIT1
 #else
+/*   #include "sqlite3.h" */
 #endif
 
 /* #include <string.h> */
 /* #include <assert.h> */
+/* #include <stdio.h> */
 
 #ifndef SQLITE_AMALGAMATION
 #include "sqlite3rtree.h"
 typedef sqlite3_int64 i64;
 typedef unsigned char u8;
+typedef unsigned short u16;
 typedef unsigned int u32;
 #endif
 
@@ -127957,6 +160050,7 @@ typedef struct RtreeConstraint RtreeConstraint;
 typedef struct RtreeMatchArg RtreeMatchArg;
 typedef struct RtreeGeomCallback RtreeGeomCallback;
 typedef union RtreeCoord RtreeCoord;
+typedef struct RtreeSearchPoint RtreeSearchPoint;
 
 /* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
 #define RTREE_MAX_DIMENSIONS 5
@@ -127965,22 +160059,33 @@ typedef union RtreeCoord RtreeCoord;
 ** ever contain very many entries, so a fixed number of buckets is 
 ** used.
 */
-#define HASHSIZE 128
+#define HASHSIZE 97
+
+/* The xBestIndex method of this virtual table requires an estimate of
+** the number of rows in the virtual table to calculate the costs of
+** various strategies. If possible, this estimate is loaded from the
+** sqlite_stat1 table (with RTREE_MIN_ROWEST as a hard-coded minimum).
+** Otherwise, if no sqlite_stat1 entry is available, use 
+** RTREE_DEFAULT_ROWEST.
+*/
+#define RTREE_DEFAULT_ROWEST 1048576
+#define RTREE_MIN_ROWEST         100
 
 /* 
 ** An rtree virtual-table object.
 */
 struct Rtree {
-  sqlite3_vtab base;
+  sqlite3_vtab base;          /* Base class.  Must be first */
   sqlite3 *db;                /* Host database connection */
   int iNodeSize;              /* Size in bytes of each node in the node table */
-  int nDim;                   /* Number of dimensions */
-  int nBytesPerCell;          /* Bytes consumed per cell */
+  u8 nDim;                    /* Number of dimensions */
+  u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */
+  u8 nBytesPerCell;           /* Bytes consumed per cell */
   int iDepth;                 /* Current depth of the r-tree structure */
   char *zDb;                  /* Name of database containing r-tree table */
   char *zName;                /* Name of r-tree table */ 
-  RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 
   int nBusy;                  /* Current number of users of this structure */
+  i64 nRowEst;                /* Estimated number of rows in this table */
 
   /* List of nodes removed during a CondenseTree operation. List is
   ** linked together via the pointer normally used for hash chains -
@@ -128005,14 +160110,46 @@ struct Rtree {
   sqlite3_stmt *pWriteParent;
   sqlite3_stmt *pDeleteParent;
 
-  int eCoordType;
+  RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 
 };
 
-/* Possible values for eCoordType: */
+/* Possible values for Rtree.eCoordType: */
 #define RTREE_COORD_REAL32 0
 #define RTREE_COORD_INT32  1
 
 /*
+** If SQLITE_RTREE_INT_ONLY is defined, then this virtual table will
+** only deal with integer coordinates.  No floating point operations
+** will be done.
+*/
+#ifdef SQLITE_RTREE_INT_ONLY
+  typedef sqlite3_int64 RtreeDValue;       /* High accuracy coordinate */
+  typedef int RtreeValue;                  /* Low accuracy coordinate */
+# define RTREE_ZERO 0
+#else
+  typedef double RtreeDValue;              /* High accuracy coordinate */
+  typedef float RtreeValue;                /* Low accuracy coordinate */
+# define RTREE_ZERO 0.0
+#endif
+
+/*
+** When doing a search of an r-tree, instances of the following structure
+** record intermediate results from the tree walk.
+**
+** The id is always a node-id.  For iLevel>=1 the id is the node-id of
+** the node that the RtreeSearchPoint represents.  When iLevel==0, however,
+** the id is of the parent node and the cell that RtreeSearchPoint
+** represents is the iCell-th entry in the parent node.
+*/
+struct RtreeSearchPoint {
+  RtreeDValue rScore;    /* The score for this node.  Smallest goes first. */
+  sqlite3_int64 id;      /* Node ID */
+  u8 iLevel;             /* 0=entries.  1=leaf node.  2+ for higher */
+  u8 eWithin;            /* PARTLY_WITHIN or FULLY_WITHIN */
+  u8 iCell;              /* Cell index within the node */
+};
+
+/*
 ** The minimum number of cells allowed for a node is a third of the 
 ** maximum. In Gutman's notation:
 **
@@ -128034,33 +160171,61 @@ struct Rtree {
 */
 #define RTREE_MAX_DEPTH 40
 
+
+/*
+** Number of entries in the cursor RtreeNode cache.  The first entry is
+** used to cache the RtreeNode for RtreeCursor.sPoint.  The remaining
+** entries cache the RtreeNode for the first elements of the priority queue.
+*/
+#define RTREE_CACHE_SZ  5
+
 /* 
 ** An rtree cursor object.
 */
 struct RtreeCursor {
-  sqlite3_vtab_cursor base;
-  RtreeNode *pNode;                 /* Node cursor is currently pointing at */
-  int iCell;                        /* Index of current cell in pNode */
+  sqlite3_vtab_cursor base;         /* Base class.  Must be first */
+  u8 atEOF;                         /* True if at end of search */
+  u8 bPoint;                        /* True if sPoint is valid */
   int iStrategy;                    /* Copy of idxNum search parameter */
   int nConstraint;                  /* Number of entries in aConstraint */
   RtreeConstraint *aConstraint;     /* Search constraints. */
+  int nPointAlloc;                  /* Number of slots allocated for aPoint[] */
+  int nPoint;                       /* Number of slots used in aPoint[] */
+  int mxLevel;                      /* iLevel value for root of the tree */
+  RtreeSearchPoint *aPoint;         /* Priority queue for search points */
+  RtreeSearchPoint sPoint;          /* Cached next search point */
+  RtreeNode *aNode[RTREE_CACHE_SZ]; /* Rtree node cache */
+  u32 anQueue[RTREE_MAX_DEPTH+1];   /* Number of queued entries by iLevel */
 };
 
+/* Return the Rtree of a RtreeCursor */
+#define RTREE_OF_CURSOR(X)   ((Rtree*)((X)->base.pVtab))
+
+/*
+** A coordinate can be either a floating point number or a integer.  All
+** coordinates within a single R-Tree are always of the same time.
+*/
 union RtreeCoord {
-  float f;
-  int i;
+  RtreeValue f;      /* Floating point value */
+  int i;             /* Integer value */
+  u32 u;             /* Unsigned for byte-order conversions */
 };
 
 /*
 ** The argument is an RtreeCoord. Return the value stored within the RtreeCoord
-** formatted as a double. This macro assumes that local variable pRtree points
-** to the Rtree structure associated with the RtreeCoord.
+** formatted as a RtreeDValue (double or int64). This macro assumes that local
+** variable pRtree points to the Rtree structure associated with the
+** RtreeCoord.
 */
-#define DCOORD(coord) (                           \
-  (pRtree->eCoordType==RTREE_COORD_REAL32) ?      \
-    ((double)coord.f) :                           \
-    ((double)coord.i)                             \
-)
+#ifdef SQLITE_RTREE_INT_ONLY
+# define DCOORD(coord) ((RtreeDValue)coord.i)
+#else
+# define DCOORD(coord) (                           \
+    (pRtree->eCoordType==RTREE_COORD_REAL32) ?      \
+      ((double)coord.f) :                           \
+      ((double)coord.i)                             \
+  )
+#endif
 
 /*
 ** A search constraint.
@@ -128068,38 +160233,67 @@ union RtreeCoord {
 struct RtreeConstraint {
   int iCoord;                     /* Index of constrained coordinate */
   int op;                         /* Constraining operation */
-  double rValue;                  /* Constraint value. */
-  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
-  sqlite3_rtree_geometry *pGeom;  /* Constraint callback argument for a MATCH */
+  union {
+    RtreeDValue rValue;             /* Constraint value. */
+    int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*);
+    int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  } u;
+  sqlite3_rtree_query_info *pInfo;  /* xGeom and xQueryFunc argument */
 };
 
 /* Possible values for RtreeConstraint.op */
-#define RTREE_EQ    0x41
-#define RTREE_LE    0x42
-#define RTREE_LT    0x43
-#define RTREE_GE    0x44
-#define RTREE_GT    0x45
-#define RTREE_MATCH 0x46
+#define RTREE_EQ    0x41  /* A */
+#define RTREE_LE    0x42  /* B */
+#define RTREE_LT    0x43  /* C */
+#define RTREE_GE    0x44  /* D */
+#define RTREE_GT    0x45  /* E */
+#define RTREE_MATCH 0x46  /* F: Old-style sqlite3_rtree_geometry_callback() */
+#define RTREE_QUERY 0x47  /* G: New-style sqlite3_rtree_query_callback() */
+
 
 /* 
 ** An rtree structure node.
 */
 struct RtreeNode {
-  RtreeNode *pParent;               /* Parent node */
-  i64 iNode;
-  int nRef;
-  int isDirty;
-  u8 *zData;
-  RtreeNode *pNext;                 /* Next node in this hash chain */
+  RtreeNode *pParent;         /* Parent node */
+  i64 iNode;                  /* The node number */
+  int nRef;                   /* Number of references to this node */
+  int isDirty;                /* True if the node needs to be written to disk */
+  u8 *zData;                  /* Content of the node, as should be on disk */
+  RtreeNode *pNext;           /* Next node in this hash collision chain */
 };
+
+/* Return the number of cells in a node  */
 #define NCELL(pNode) readInt16(&(pNode)->zData[2])
 
 /* 
-** Structure to store a deserialized rtree record.
+** A single cell from a node, deserialized
 */
 struct RtreeCell {
-  i64 iRowid;
-  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
+  i64 iRowid;                                 /* Node or entry ID */
+  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];  /* Bounding box coordinates */
+};
+
+
+/*
+** This object becomes the sqlite3_user_data() for the SQL functions
+** that are created by sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() and which appear on the right of MATCH
+** operators in order to constrain a search.
+**
+** xGeom and xQueryFunc are the callback functions.  Exactly one of 
+** xGeom and xQueryFunc fields is non-NULL, depending on whether the
+** SQL function was created using sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback().
+** 
+** This object is deleted automatically by the destructor mechanism in
+** sqlite3_create_function_v2().
+*/
+struct RtreeGeomCallback {
+  int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
+  int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  void (*xDestructor)(void*);
+  void *pContext;
 };
 
 
@@ -128111,29 +160305,17 @@ struct RtreeCell {
 #define RTREE_GEOMETRY_MAGIC 0x891245AB
 
 /*
-** An instance of this structure must be supplied as a blob argument to
-** the right-hand-side of an SQL MATCH operator used to constrain an
-** r-tree query.
+** An instance of this structure (in the form of a BLOB) is returned by
+** the SQL functions that sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() create, and is read as the right-hand
+** operand to the MATCH operator of an R-Tree.
 */
 struct RtreeMatchArg {
-  u32 magic;                      /* Always RTREE_GEOMETRY_MAGIC */
-  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
-  void *pContext;
-  int nParam;
-  double aParam[1];
-};
-
-/*
-** When a geometry callback is created (see sqlite3_rtree_geometry_callback),
-** a single instance of the following structure is allocated. It is used
-** as the context for the user-function created by by s_r_g_c(). The object
-** is eventually deleted by the destructor mechanism provided by
-** sqlite3_create_function_v2() (which is called by s_r_g_c() to create
-** the geometry callback function).
-*/
-struct RtreeGeomCallback {
-  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *);
-  void *pContext;
+  u32 magic;                  /* Always RTREE_GEOMETRY_MAGIC */
+  RtreeGeomCallback cb;       /* Info about the callback functions */
+  int nParam;                 /* Number of parameters to the SQL function */
+  sqlite3_value **apSqlParam; /* Original SQL parameter values */
+  RtreeDValue aParam[1];      /* Values for parameters to the SQL function */
 };
 
 #ifndef MAX
@@ -128151,13 +160333,12 @@ static int readInt16(u8 *p){
   return (p[0]<<8) + p[1];
 }
 static void readCoord(u8 *p, RtreeCoord *pCoord){
-  u32 i = (
+  pCoord->u = (
     (((u32)p[0]) << 24) + 
     (((u32)p[1]) << 16) + 
     (((u32)p[2]) <<  8) + 
     (((u32)p[3]) <<  0)
   );
-  *(u32 *)pCoord = i;
 }
 static i64 readInt64(u8 *p){
   return (
@@ -128186,7 +160367,7 @@ static int writeCoord(u8 *p, RtreeCoord *pCoord){
   u32 i;
   assert( sizeof(RtreeCoord)==4 );
   assert( sizeof(u32)==4 );
-  i = *(u32 *)pCoord;
+  i = pCoord->u;
   p[0] = (i>>24)&0xFF;
   p[1] = (i>>16)&0xFF;
   p[2] = (i>> 8)&0xFF;
@@ -128227,10 +160408,7 @@ static void nodeZero(Rtree *pRtree, RtreeNode *p){
 ** in the Rtree.aHash table.
 */
 static int nodeHash(i64 iNode){
-  return (
-    (iNode>>56) ^ (iNode>>48) ^ (iNode>>40) ^ (iNode>>32) ^ 
-    (iNode>>24) ^ (iNode>>16) ^ (iNode>> 8) ^ (iNode>> 0)
-  ) % HASHSIZE;
+  return iNode % HASHSIZE;
 }
 
 /*
@@ -128290,8 +160468,7 @@ static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
 /*
 ** Obtain a reference to an r-tree node.
 */
-static int
-nodeAcquire(
+static int nodeAcquire(
   Rtree *pRtree,             /* R-tree structure */
   i64 iNode,                 /* Node number to load */
   RtreeNode *pParent,        /* Either the parent node or NULL */
@@ -128380,10 +160557,10 @@ nodeAcquire(
 ** Overwrite cell iCell of node pNode with the contents of pCell.
 */
 static void nodeOverwriteCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode,  
-  RtreeCell *pCell, 
-  int iCell
+  Rtree *pRtree,             /* The overall R-Tree */
+  RtreeNode *pNode,          /* The node into which the cell is to be written */
+  RtreeCell *pCell,          /* The cell to write */
+  int iCell                  /* Index into pNode into which pCell is written */
 ){
   int ii;
   u8 *p = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
@@ -128395,7 +160572,7 @@ static void nodeOverwriteCell(
 }
 
 /*
-** Remove cell the cell with index iCell from node pNode.
+** Remove the cell with index iCell from node pNode.
 */
 static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){
   u8 *pDst = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
@@ -128412,11 +160589,10 @@ static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){
 **
 ** If there is not enough free space in pNode, return SQLITE_FULL.
 */
-static int
-nodeInsertCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  RtreeCell *pCell 
+static int nodeInsertCell(
+  Rtree *pRtree,                /* The overall R-Tree */
+  RtreeNode *pNode,             /* Write new cell into this node */
+  RtreeCell *pCell              /* The cell to be inserted */
 ){
   int nCell;                    /* Current number of cells in pNode */
   int nMaxCell;                 /* Maximum number of cells for pNode */
@@ -128437,8 +160613,7 @@ nodeInsertCell(
 /*
 ** If the node is dirty, write it out to the database.
 */
-static int
-nodeWrite(Rtree *pRtree, RtreeNode *pNode){
+static int nodeWrite(Rtree *pRtree, RtreeNode *pNode){
   int rc = SQLITE_OK;
   if( pNode->isDirty ){
     sqlite3_stmt *p = pRtree->pWriteNode;
@@ -128463,8 +160638,7 @@ nodeWrite(Rtree *pRtree, RtreeNode *pNode){
 ** Release a reference to a node. If the node is dirty and the reference
 ** count drops to zero, the node data is written to the database.
 */
-static int
-nodeRelease(Rtree *pRtree, RtreeNode *pNode){
+static int nodeRelease(Rtree *pRtree, RtreeNode *pNode){
   int rc = SQLITE_OK;
   if( pNode ){
     assert( pNode->nRef>0 );
@@ -128492,9 +160666,9 @@ nodeRelease(Rtree *pRtree, RtreeNode *pNode){
 ** an internal node, then the 64-bit integer is a child page number.
 */
 static i64 nodeGetRowid(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell
+  Rtree *pRtree,       /* The overall R-Tree */
+  RtreeNode *pNode,    /* The node from which to extract the ID */
+  int iCell            /* The cell index from which to extract the ID */
 ){
   assert( iCell<NCELL(pNode) );
   return readInt64(&pNode->zData[4 + pRtree->nBytesPerCell*iCell]);
@@ -128504,11 +160678,11 @@ static i64 nodeGetRowid(
 ** Return coordinate iCoord from cell iCell in node pNode.
 */
 static void nodeGetCoord(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell,
-  int iCoord,
-  RtreeCoord *pCoord           /* Space to write result to */
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node from which to extract a coordinate */
+  int iCell,                   /* The index of the cell within the node */
+  int iCoord,                  /* Which coordinate to extract */
+  RtreeCoord *pCoord           /* OUT: Space to write result to */
 ){
   readCoord(&pNode->zData[12 + pRtree->nBytesPerCell*iCell + 4*iCoord], pCoord);
 }
@@ -128518,15 +160692,19 @@ static void nodeGetCoord(
 ** to by pCell with the results.
 */
 static void nodeGetCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell,
-  RtreeCell *pCell
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node containing the cell to be read */
+  int iCell,                   /* Index of the cell within the node */
+  RtreeCell *pCell             /* OUT: Write the cell contents here */
 ){
+  u8 *pData;
+  RtreeCoord *pCoord;
   int ii;
   pCell->iRowid = nodeGetRowid(pRtree, pNode, iCell);
+  pData = pNode->zData + (12 + pRtree->nBytesPerCell*iCell);
+  pCoord = pCell->aCoord;
   for(ii=0; ii<pRtree->nDim*2; ii++){
-    nodeGetCoord(pRtree, pNode, iCell, ii, &pCell->aCoord[ii]);
+    readCoord(&pData[ii*4], &pCoord[ii]);
   }
 }
 
@@ -128652,10 +160830,10 @@ static void freeCursorConstraints(RtreeCursor *pCsr){
   if( pCsr->aConstraint ){
     int i;                        /* Used to iterate through constraint array */
     for(i=0; i<pCsr->nConstraint; i++){
-      sqlite3_rtree_geometry *pGeom = pCsr->aConstraint[i].pGeom;
-      if( pGeom ){
-        if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
-        sqlite3_free(pGeom);
+      sqlite3_rtree_query_info *pInfo = pCsr->aConstraint[i].pInfo;
+      if( pInfo ){
+        if( pInfo->xDelUser ) pInfo->xDelUser(pInfo->pUser);
+        sqlite3_free(pInfo);
       }
     }
     sqlite3_free(pCsr->aConstraint);
@@ -128668,12 +160846,13 @@ static void freeCursorConstraints(RtreeCursor *pCsr){
 */
 static int rtreeClose(sqlite3_vtab_cursor *cur){
   Rtree *pRtree = (Rtree *)(cur->pVtab);
-  int rc;
+  int ii;
   RtreeCursor *pCsr = (RtreeCursor *)cur;
   freeCursorConstraints(pCsr);
-  rc = nodeRelease(pRtree, pCsr->pNode);
+  sqlite3_free(pCsr->aPoint);
+  for(ii=0; ii<RTREE_CACHE_SZ; ii++) nodeRelease(pRtree, pCsr->aNode[ii]);
   sqlite3_free(pCsr);
-  return rc;
+  return SQLITE_OK;
 }
 
 /*
@@ -128684,194 +160863,164 @@ static int rtreeClose(sqlite3_vtab_cursor *cur){
 */
 static int rtreeEof(sqlite3_vtab_cursor *cur){
   RtreeCursor *pCsr = (RtreeCursor *)cur;
-  return (pCsr->pNode==0);
+  return pCsr->atEOF;
+}
+
+/*
+** Convert raw bits from the on-disk RTree record into a coordinate value.
+** The on-disk format is big-endian and needs to be converted for little-
+** endian platforms.  The on-disk record stores integer coordinates if
+** eInt is true and it stores 32-bit floating point records if eInt is
+** false.  a[] is the four bytes of the on-disk record to be decoded.
+** Store the results in "r".
+**
+** There are three versions of this macro, one each for little-endian and
+** big-endian processors and a third generic implementation.  The endian-
+** specific implementations are much faster and are preferred if the
+** processor endianness is known at compile-time.  The SQLITE_BYTEORDER
+** macro is part of sqliteInt.h and hence the endian-specific
+** implementation will only be used if this module is compiled as part
+** of the amalgamation.
+*/
+#if defined(SQLITE_BYTEORDER) && SQLITE_BYTEORDER==1234
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    c.u = ((c.u>>24)&0xff)|((c.u>>8)&0xff00)|                   \
+          ((c.u&0xff)<<24)|((c.u&0xff00)<<8);                   \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#elif defined(SQLITE_BYTEORDER) && SQLITE_BYTEORDER==4321
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
 }
+#else
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    c.u = ((u32)a[0]<<24) + ((u32)a[1]<<16)                     \
+           +((u32)a[2]<<8) + a[3];                              \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#endif
 
 /*
-** The r-tree constraint passed as the second argument to this function is
-** guaranteed to be a MATCH constraint.
+** Check the RTree node or entry given by pCellData and p against the MATCH
+** constraint pConstraint.  
 */
-static int testRtreeGeom(
-  Rtree *pRtree,                  /* R-Tree object */
-  RtreeConstraint *pConstraint,   /* MATCH constraint to test */
-  RtreeCell *pCell,               /* Cell to test */
-  int *pbRes                      /* OUT: Test result */
+static int rtreeCallbackConstraint(
+  RtreeConstraint *pConstraint,  /* The constraint to test */
+  int eInt,                      /* True if RTree holding integer coordinates */
+  u8 *pCellData,                 /* Raw cell content */
+  RtreeSearchPoint *pSearch,     /* Container of this cell */
+  sqlite3_rtree_dbl *prScore,    /* OUT: score for the cell */
+  int *peWithin                  /* OUT: visibility of the cell */
 ){
-  int i;
-  double aCoord[RTREE_MAX_DIMENSIONS*2];
-  int nCoord = pRtree->nDim*2;
+  int i;                                                /* Loop counter */
+  sqlite3_rtree_query_info *pInfo = pConstraint->pInfo; /* Callback info */
+  int nCoord = pInfo->nCoord;                           /* No. of coordinates */
+  int rc;                                             /* Callback return code */
+  sqlite3_rtree_dbl aCoord[RTREE_MAX_DIMENSIONS*2];   /* Decoded coordinates */
 
-  assert( pConstraint->op==RTREE_MATCH );
-  assert( pConstraint->pGeom );
+  assert( pConstraint->op==RTREE_MATCH || pConstraint->op==RTREE_QUERY );
+  assert( nCoord==2 || nCoord==4 || nCoord==6 || nCoord==8 || nCoord==10 );
 
-  for(i=0; i<nCoord; i++){
-    aCoord[i] = DCOORD(pCell->aCoord[i]);
+  if( pConstraint->op==RTREE_QUERY && pSearch->iLevel==1 ){
+    pInfo->iRowid = readInt64(pCellData);
   }
-  return pConstraint->xGeom(pConstraint->pGeom, nCoord, aCoord, pbRes);
-}
-
-/* 
-** Cursor pCursor currently points to a cell in a non-leaf page.
-** Set *pbEof to true if the sub-tree headed by the cell is filtered
-** (excluded) by the constraints in the pCursor->aConstraint[] 
-** array, or false otherwise.
-**
-** Return SQLITE_OK if successful or an SQLite error code if an error
-** occurs within a geometry callback.
-*/
-static int testRtreeCell(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
-  RtreeCell cell;
-  int ii;
-  int bRes = 0;
-  int rc = SQLITE_OK;
-
-  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
-  for(ii=0; bRes==0 && ii<pCursor->nConstraint; ii++){
-    RtreeConstraint *p = &pCursor->aConstraint[ii];
-    double cell_min = DCOORD(cell.aCoord[(p->iCoord>>1)*2]);
-    double cell_max = DCOORD(cell.aCoord[(p->iCoord>>1)*2+1]);
-
-    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
-        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
-    );
-
-    switch( p->op ){
-      case RTREE_LE: case RTREE_LT: 
-        bRes = p->rValue<cell_min; 
-        break;
-
-      case RTREE_GE: case RTREE_GT: 
-        bRes = p->rValue>cell_max; 
-        break;
-
-      case RTREE_EQ:
-        bRes = (p->rValue>cell_max || p->rValue<cell_min);
-        break;
-
-      default: {
-        assert( p->op==RTREE_MATCH );
-        rc = testRtreeGeom(pRtree, p, &cell, &bRes);
-        bRes = !bRes;
-        break;
-      }
+  pCellData += 8;
+  for(i=0; i<nCoord; i++, pCellData += 4){
+    RTREE_DECODE_COORD(eInt, pCellData, aCoord[i]);
+  }
+  if( pConstraint->op==RTREE_MATCH ){
+    rc = pConstraint->u.xGeom((sqlite3_rtree_geometry*)pInfo,
+                              nCoord, aCoord, &i);
+    if( i==0 ) *peWithin = NOT_WITHIN;
+    *prScore = RTREE_ZERO;
+  }else{
+    pInfo->aCoord = aCoord;
+    pInfo->iLevel = pSearch->iLevel - 1;
+    pInfo->rScore = pInfo->rParentScore = pSearch->rScore;
+    pInfo->eWithin = pInfo->eParentWithin = pSearch->eWithin;
+    rc = pConstraint->u.xQueryFunc(pInfo);
+    if( pInfo->eWithin<*peWithin ) *peWithin = pInfo->eWithin;
+    if( pInfo->rScore<*prScore || *prScore<RTREE_ZERO ){
+      *prScore = pInfo->rScore;
     }
   }
-
-  *pbEof = bRes;
   return rc;
 }
 
 /* 
-** Test if the cell that cursor pCursor currently points to
-** would be filtered (excluded) by the constraints in the 
-** pCursor->aConstraint[] array. If so, set *pbEof to true before
-** returning. If the cell is not filtered (excluded) by the constraints,
-** set pbEof to zero.
-**
-** Return SQLITE_OK if successful or an SQLite error code if an error
-** occurs within a geometry callback.
-**
-** This function assumes that the cell is part of a leaf node.
+** Check the internal RTree node given by pCellData against constraint p.
+** If this constraint cannot be satisfied by any child within the node,
+** set *peWithin to NOT_WITHIN.
 */
-static int testRtreeEntry(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
-  RtreeCell cell;
-  int ii;
-  *pbEof = 0;
+static void rtreeNonleafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
+){
+  sqlite3_rtree_dbl val;     /* Coordinate value convert to a double */
 
-  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
-  for(ii=0; ii<pCursor->nConstraint; ii++){
-    RtreeConstraint *p = &pCursor->aConstraint[ii];
-    double coord = DCOORD(cell.aCoord[p->iCoord]);
-    int res;
-    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
-        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
-    );
-    switch( p->op ){
-      case RTREE_LE: res = (coord<=p->rValue); break;
-      case RTREE_LT: res = (coord<p->rValue);  break;
-      case RTREE_GE: res = (coord>=p->rValue); break;
-      case RTREE_GT: res = (coord>p->rValue);  break;
-      case RTREE_EQ: res = (coord==p->rValue); break;
-      default: {
-        int rc;
-        assert( p->op==RTREE_MATCH );
-        rc = testRtreeGeom(pRtree, p, &cell, &res);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        break;
-      }
-    }
+  /* p->iCoord might point to either a lower or upper bound coordinate
+  ** in a coordinate pair.  But make pCellData point to the lower bound.
+  */
+  pCellData += 8 + 4*(p->iCoord&0xfe);
 
-    if( !res ){
-      *pbEof = 1;
-      return SQLITE_OK;
-    }
-  }
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  switch( p->op ){
+    case RTREE_LE:
+    case RTREE_LT:
+    case RTREE_EQ:
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the lower bound of the coordinate pair */
+      if( p->u.rValue>=val ) return;
+      if( p->op!=RTREE_EQ ) break;  /* RTREE_LE and RTREE_LT end here */
+      /* Fall through for the RTREE_EQ case */
 
-  return SQLITE_OK;
+    default: /* RTREE_GT or RTREE_GE,  or fallthrough of RTREE_EQ */
+      pCellData += 4;
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the upper bound of the coordinate pair */
+      if( p->u.rValue<=val ) return;
+  }
+  *peWithin = NOT_WITHIN;
 }
 
 /*
-** Cursor pCursor currently points at a node that heads a sub-tree of
-** height iHeight (if iHeight==0, then the node is a leaf). Descend
-** to point to the left-most cell of the sub-tree that matches the 
-** configured constraints.
+** Check the leaf RTree cell given by pCellData against constraint p.
+** If this constraint is not satisfied, set *peWithin to NOT_WITHIN.
+** If the constraint is satisfied, leave *peWithin unchanged.
+**
+** The constraint is of the form:  xN op $val
+**
+** The op is given by p->op.  The xN is p->iCoord-th coordinate in
+** pCellData.  $val is given by p->u.rValue.
 */
-static int descendToCell(
-  Rtree *pRtree, 
-  RtreeCursor *pCursor, 
-  int iHeight,
-  int *pEof                 /* OUT: Set to true if cannot descend */
+static void rtreeLeafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
 ){
-  int isEof;
-  int rc;
-  int ii;
-  RtreeNode *pChild;
-  sqlite3_int64 iRowid;
-
-  RtreeNode *pSavedNode = pCursor->pNode;
-  int iSavedCell = pCursor->iCell;
+  RtreeDValue xN;      /* Coordinate value converted to a double */
 
-  assert( iHeight>=0 );
-
-  if( iHeight==0 ){
-    rc = testRtreeEntry(pRtree, pCursor, &isEof);
-  }else{
-    rc = testRtreeCell(pRtree, pCursor, &isEof);
-  }
-  if( rc!=SQLITE_OK || isEof || iHeight==0 ){
-    goto descend_to_cell_out;
-  }
-
-  iRowid = nodeGetRowid(pRtree, pCursor->pNode, pCursor->iCell);
-  rc = nodeAcquire(pRtree, iRowid, pCursor->pNode, &pChild);
-  if( rc!=SQLITE_OK ){
-    goto descend_to_cell_out;
-  }
-
-  nodeRelease(pRtree, pCursor->pNode);
-  pCursor->pNode = pChild;
-  isEof = 1;
-  for(ii=0; isEof && ii<NCELL(pChild); ii++){
-    pCursor->iCell = ii;
-    rc = descendToCell(pRtree, pCursor, iHeight-1, &isEof);
-    if( rc!=SQLITE_OK ){
-      goto descend_to_cell_out;
-    }
-  }
-
-  if( isEof ){
-    assert( pCursor->pNode==pChild );
-    nodeReference(pSavedNode);
-    nodeRelease(pRtree, pChild);
-    pCursor->pNode = pSavedNode;
-    pCursor->iCell = iSavedCell;
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  pCellData += 8 + p->iCoord*4;
+  RTREE_DECODE_COORD(eInt, pCellData, xN);
+  switch( p->op ){
+    case RTREE_LE: if( xN <= p->u.rValue ) return;  break;
+    case RTREE_LT: if( xN <  p->u.rValue ) return;  break;
+    case RTREE_GE: if( xN >= p->u.rValue ) return;  break;
+    case RTREE_GT: if( xN >  p->u.rValue ) return;  break;
+    default:       if( xN == p->u.rValue ) return;  break;
   }
-
-descend_to_cell_out:
-  *pEof = isEof;
-  return rc;
+  *peWithin = NOT_WITHIN;
 }
 
 /*
@@ -128886,6 +161035,7 @@ static int nodeRowidIndex(
 ){
   int ii;
   int nCell = NCELL(pNode);
+  assert( nCell<200 );
   for(ii=0; ii<nCell; ii++){
     if( nodeGetRowid(pRtree, pNode, ii)==iRowid ){
       *piIndex = ii;
@@ -128908,48 +161058,302 @@ static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){
   return SQLITE_OK;
 }
 
-/* 
-** Rtree virtual table module xNext method.
+/*
+** Compare two search points.  Return negative, zero, or positive if the first
+** is less than, equal to, or greater than the second.
+**
+** The rScore is the primary key.  Smaller rScore values come first.
+** If the rScore is a tie, then use iLevel as the tie breaker with smaller
+** iLevel values coming first.  In this way, if rScore is the same for all
+** SearchPoints, then iLevel becomes the deciding factor and the result
+** is a depth-first search, which is the desired default behavior.
 */
-static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
-  Rtree *pRtree = (Rtree *)(pVtabCursor->pVtab);
-  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-  int rc = SQLITE_OK;
+static int rtreeSearchPointCompare(
+  const RtreeSearchPoint *pA,
+  const RtreeSearchPoint *pB
+){
+  if( pA->rScore<pB->rScore ) return -1;
+  if( pA->rScore>pB->rScore ) return +1;
+  if( pA->iLevel<pB->iLevel ) return -1;
+  if( pA->iLevel>pB->iLevel ) return +1;
+  return 0;
+}
 
-  /* RtreeCursor.pNode must not be NULL. If is is NULL, then this cursor is
-  ** already at EOF. It is against the rules to call the xNext() method of
-  ** a cursor that has already reached EOF.
-  */
-  assert( pCsr->pNode );
-
-  if( pCsr->iStrategy==1 ){
-    /* This "scan" is a direct lookup by rowid. There is no next entry. */
-    nodeRelease(pRtree, pCsr->pNode);
-    pCsr->pNode = 0;
-  }else{
-    /* Move to the next entry that matches the configured constraints. */
-    int iHeight = 0;
-    while( pCsr->pNode ){
-      RtreeNode *pNode = pCsr->pNode;
-      int nCell = NCELL(pNode);
-      for(pCsr->iCell++; pCsr->iCell<nCell; pCsr->iCell++){
-        int isEof;
-        rc = descendToCell(pRtree, pCsr, iHeight, &isEof);
-        if( rc!=SQLITE_OK || !isEof ){
-          return rc;
+/*
+** Interchange to search points in a cursor.
+*/
+static void rtreeSearchPointSwap(RtreeCursor *p, int i, int j){
+  RtreeSearchPoint t = p->aPoint[i];
+  assert( i<j );
+  p->aPoint[i] = p->aPoint[j];
+  p->aPoint[j] = t;
+  i++; j++;
+  if( i<RTREE_CACHE_SZ ){
+    if( j>=RTREE_CACHE_SZ ){
+      nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+      p->aNode[i] = 0;
+    }else{
+      RtreeNode *pTemp = p->aNode[i];
+      p->aNode[i] = p->aNode[j];
+      p->aNode[j] = pTemp;
+    }
+  }
+}
+
+/*
+** Return the search point with the lowest current score.
+*/
+static RtreeSearchPoint *rtreeSearchPointFirst(RtreeCursor *pCur){
+  return pCur->bPoint ? &pCur->sPoint : pCur->nPoint ? pCur->aPoint : 0;
+}
+
+/*
+** Get the RtreeNode for the search point with the lowest score.
+*/
+static RtreeNode *rtreeNodeOfFirstSearchPoint(RtreeCursor *pCur, int *pRC){
+  sqlite3_int64 id;
+  int ii = 1 - pCur->bPoint;
+  assert( ii==0 || ii==1 );
+  assert( pCur->bPoint || pCur->nPoint );
+  if( pCur->aNode[ii]==0 ){
+    assert( pRC!=0 );
+    id = ii ? pCur->aPoint[0].id : pCur->sPoint.id;
+    *pRC = nodeAcquire(RTREE_OF_CURSOR(pCur), id, 0, &pCur->aNode[ii]);
+  }
+  return pCur->aNode[ii];
+}
+
+/*
+** Push a new element onto the priority queue
+*/
+static RtreeSearchPoint *rtreeEnqueue(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
+){
+  int i, j;
+  RtreeSearchPoint *pNew;
+  if( pCur->nPoint>=pCur->nPointAlloc ){
+    int nNew = pCur->nPointAlloc*2 + 8;
+    pNew = sqlite3_realloc(pCur->aPoint, nNew*sizeof(pCur->aPoint[0]));
+    if( pNew==0 ) return 0;
+    pCur->aPoint = pNew;
+    pCur->nPointAlloc = nNew;
+  }
+  i = pCur->nPoint++;
+  pNew = pCur->aPoint + i;
+  pNew->rScore = rScore;
+  pNew->iLevel = iLevel;
+  assert( iLevel<=RTREE_MAX_DEPTH );
+  while( i>0 ){
+    RtreeSearchPoint *pParent;
+    j = (i-1)/2;
+    pParent = pCur->aPoint + j;
+    if( rtreeSearchPointCompare(pNew, pParent)>=0 ) break;
+    rtreeSearchPointSwap(pCur, j, i);
+    i = j;
+    pNew = pParent;
+  }
+  return pNew;
+}
+
+/*
+** Allocate a new RtreeSearchPoint and return a pointer to it.  Return
+** NULL if malloc fails.
+*/
+static RtreeSearchPoint *rtreeSearchPointNew(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
+){
+  RtreeSearchPoint *pNew, *pFirst;
+  pFirst = rtreeSearchPointFirst(pCur);
+  pCur->anQueue[iLevel]++;
+  if( pFirst==0
+   || pFirst->rScore>rScore 
+   || (pFirst->rScore==rScore && pFirst->iLevel>iLevel)
+  ){
+    if( pCur->bPoint ){
+      int ii;
+      pNew = rtreeEnqueue(pCur, rScore, iLevel);
+      if( pNew==0 ) return 0;
+      ii = (int)(pNew - pCur->aPoint) + 1;
+      if( ii<RTREE_CACHE_SZ ){
+        assert( pCur->aNode[ii]==0 );
+        pCur->aNode[ii] = pCur->aNode[0];
+       }else{
+        nodeRelease(RTREE_OF_CURSOR(pCur), pCur->aNode[0]);
+      }
+      pCur->aNode[0] = 0;
+      *pNew = pCur->sPoint;
+    }
+    pCur->sPoint.rScore = rScore;
+    pCur->sPoint.iLevel = iLevel;
+    pCur->bPoint = 1;
+    return &pCur->sPoint;
+  }else{
+    return rtreeEnqueue(pCur, rScore, iLevel);
+  }
+}
+
+#if 0
+/* Tracing routines for the RtreeSearchPoint queue */
+static void tracePoint(RtreeSearchPoint *p, int idx, RtreeCursor *pCur){
+  if( idx<0 ){ printf(" s"); }else{ printf("%2d", idx); }
+  printf(" %d.%05lld.%02d %g %d",
+    p->iLevel, p->id, p->iCell, p->rScore, p->eWithin
+  );
+  idx++;
+  if( idx<RTREE_CACHE_SZ ){
+    printf(" %p\n", pCur->aNode[idx]);
+  }else{
+    printf("\n");
+  }
+}
+static void traceQueue(RtreeCursor *pCur, const char *zPrefix){
+  int ii;
+  printf("=== %9s ", zPrefix);
+  if( pCur->bPoint ){
+    tracePoint(&pCur->sPoint, -1, pCur);
+  }
+  for(ii=0; ii<pCur->nPoint; ii++){
+    if( ii>0 || pCur->bPoint ) printf("              ");
+    tracePoint(&pCur->aPoint[ii], ii, pCur);
+  }
+}
+# define RTREE_QUEUE_TRACE(A,B) traceQueue(A,B)
+#else
+# define RTREE_QUEUE_TRACE(A,B)   /* no-op */
+#endif
+
+/* Remove the search point with the lowest current score.
+*/
+static void rtreeSearchPointPop(RtreeCursor *p){
+  int i, j, k, n;
+  i = 1 - p->bPoint;
+  assert( i==0 || i==1 );
+  if( p->aNode[i] ){
+    nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+    p->aNode[i] = 0;
+  }
+  if( p->bPoint ){
+    p->anQueue[p->sPoint.iLevel]--;
+    p->bPoint = 0;
+  }else if( p->nPoint ){
+    p->anQueue[p->aPoint[0].iLevel]--;
+    n = --p->nPoint;
+    p->aPoint[0] = p->aPoint[n];
+    if( n<RTREE_CACHE_SZ-1 ){
+      p->aNode[1] = p->aNode[n+1];
+      p->aNode[n+1] = 0;
+    }
+    i = 0;
+    while( (j = i*2+1)<n ){
+      k = j+1;
+      if( k<n && rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[j])<0 ){
+        if( rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, k);
+          i = k;
+        }else{
+          break;
+        }
+      }else{
+        if( rtreeSearchPointCompare(&p->aPoint[j], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, j);
+          i = j;
+        }else{
+          break;
         }
       }
-      pCsr->pNode = pNode->pParent;
-      rc = nodeParentIndex(pRtree, pNode, &pCsr->iCell);
-      if( rc!=SQLITE_OK ){
-        return rc;
-      }
-      nodeReference(pCsr->pNode);
-      nodeRelease(pRtree, pNode);
-      iHeight++;
     }
   }
+}
 
+
+/*
+** Continue the search on cursor pCur until the front of the queue
+** contains an entry suitable for returning as a result-set row,
+** or until the RtreeSearchPoint queue is empty, indicating that the
+** query has completed.
+*/
+static int rtreeStepToLeaf(RtreeCursor *pCur){
+  RtreeSearchPoint *p;
+  Rtree *pRtree = RTREE_OF_CURSOR(pCur);
+  RtreeNode *pNode;
+  int eWithin;
+  int rc = SQLITE_OK;
+  int nCell;
+  int nConstraint = pCur->nConstraint;
+  int ii;
+  int eInt;
+  RtreeSearchPoint x;
+
+  eInt = pRtree->eCoordType==RTREE_COORD_INT32;
+  while( (p = rtreeSearchPointFirst(pCur))!=0 && p->iLevel>0 ){
+    pNode = rtreeNodeOfFirstSearchPoint(pCur, &rc);
+    if( rc ) return rc;
+    nCell = NCELL(pNode);
+    assert( nCell<200 );
+    while( p->iCell<nCell ){
+      sqlite3_rtree_dbl rScore = (sqlite3_rtree_dbl)-1;
+      u8 *pCellData = pNode->zData + (4+pRtree->nBytesPerCell*p->iCell);
+      eWithin = FULLY_WITHIN;
+      for(ii=0; ii<nConstraint; ii++){
+        RtreeConstraint *pConstraint = pCur->aConstraint + ii;
+        if( pConstraint->op>=RTREE_MATCH ){
+          rc = rtreeCallbackConstraint(pConstraint, eInt, pCellData, p,
+                                       &rScore, &eWithin);
+          if( rc ) return rc;
+        }else if( p->iLevel==1 ){
+          rtreeLeafConstraint(pConstraint, eInt, pCellData, &eWithin);
+        }else{
+          rtreeNonleafConstraint(pConstraint, eInt, pCellData, &eWithin);
+        }
+        if( eWithin==NOT_WITHIN ) break;
+      }
+      p->iCell++;
+      if( eWithin==NOT_WITHIN ) continue;
+      x.iLevel = p->iLevel - 1;
+      if( x.iLevel ){
+        x.id = readInt64(pCellData);
+        x.iCell = 0;
+      }else{
+        x.id = p->id;
+        x.iCell = p->iCell - 1;
+      }
+      if( p->iCell>=nCell ){
+        RTREE_QUEUE_TRACE(pCur, "POP-S:");
+        rtreeSearchPointPop(pCur);
+      }
+      if( rScore<RTREE_ZERO ) rScore = RTREE_ZERO;
+      p = rtreeSearchPointNew(pCur, rScore, x.iLevel);
+      if( p==0 ) return SQLITE_NOMEM;
+      p->eWithin = eWithin;
+      p->id = x.id;
+      p->iCell = x.iCell;
+      RTREE_QUEUE_TRACE(pCur, "PUSH-S:");
+      break;
+    }
+    if( p->iCell>=nCell ){
+      RTREE_QUEUE_TRACE(pCur, "POP-Se:");
+      rtreeSearchPointPop(pCur);
+    }
+  }
+  pCur->atEOF = p==0;
+  return SQLITE_OK;
+}
+
+/* 
+** Rtree virtual table module xNext method.
+*/
+static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
+  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
+  int rc = SQLITE_OK;
+
+  /* Move to the next entry that matches the configured constraints. */
+  RTREE_QUEUE_TRACE(pCsr, "POP-Nx:");
+  rtreeSearchPointPop(pCsr);
+  rc = rtreeStepToLeaf(pCsr);
   return rc;
 }
 
@@ -128957,13 +161361,14 @@ static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
 ** Rtree virtual table module xRowid method.
 */
 static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
-  Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-
-  assert(pCsr->pNode);
-  *pRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
-
-  return SQLITE_OK;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
+  if( rc==SQLITE_OK && p ){
+    *pRowid = nodeGetRowid(RTREE_OF_CURSOR(pCsr), pNode, p->iCell);
+  }
+  return rc;
 }
 
 /* 
@@ -128972,21 +161377,28 @@ static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
 static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
   Rtree *pRtree = (Rtree *)cur->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)cur;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  RtreeCoord c;
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
 
+  if( rc ) return rc;
+  if( p==0 ) return SQLITE_OK;
   if( i==0 ){
-    i64 iRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
-    sqlite3_result_int64(ctx, iRowid);
+    sqlite3_result_int64(ctx, nodeGetRowid(pRtree, pNode, p->iCell));
   }else{
-    RtreeCoord c;
-    nodeGetCoord(pRtree, pCsr->pNode, pCsr->iCell, i-1, &c);
+    if( rc ) return rc;
+    nodeGetCoord(pRtree, pNode, p->iCell, i-1, &c);
+#ifndef SQLITE_RTREE_INT_ONLY
     if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
       sqlite3_result_double(ctx, c.f);
-    }else{
+    }else
+#endif
+    {
       assert( pRtree->eCoordType==RTREE_COORD_INT32 );
       sqlite3_result_int(ctx, c.i);
     }
   }
-
   return SQLITE_OK;
 }
 
@@ -128997,12 +161409,18 @@ static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
 ** *ppLeaf to 0 and return SQLITE_OK. If an error occurs, set *ppLeaf
 ** to zero and return an SQLite error code.
 */
-static int findLeafNode(Rtree *pRtree, i64 iRowid, RtreeNode **ppLeaf){
+static int findLeafNode(
+  Rtree *pRtree,              /* RTree to search */
+  i64 iRowid,                 /* The rowid searching for */
+  RtreeNode **ppLeaf,         /* Write the node here */
+  sqlite3_int64 *piNode       /* Write the node-id here */
+){
   int rc;
   *ppLeaf = 0;
   sqlite3_bind_int64(pRtree->pReadRowid, 1, iRowid);
   if( sqlite3_step(pRtree->pReadRowid)==SQLITE_ROW ){
     i64 iNode = sqlite3_column_int64(pRtree->pReadRowid, 0);
+    if( piNode ) *piNode = iNode;
     rc = nodeAcquire(pRtree, iNode, 0, ppLeaf);
     sqlite3_reset(pRtree->pReadRowid);
   }else{
@@ -129018,42 +161436,45 @@ static int findLeafNode(Rtree *pRtree, i64 iRowid, RtreeNode **ppLeaf){
 ** operator.
 */
 static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
-  RtreeMatchArg *p;
-  sqlite3_rtree_geometry *pGeom;
-  int nBlob;
+  RtreeMatchArg *pBlob;              /* BLOB returned by geometry function */
+  sqlite3_rtree_query_info *pInfo;   /* Callback information */
+  int nBlob;                         /* Size of the geometry function blob */
+  int nExpected;                     /* Expected size of the BLOB */
 
   /* Check that value is actually a blob. */
-  if( !sqlite3_value_type(pValue)==SQLITE_BLOB ) return SQLITE_ERROR;
+  if( sqlite3_value_type(pValue)!=SQLITE_BLOB ) return SQLITE_ERROR;
 
   /* Check that the blob is roughly the right size. */
   nBlob = sqlite3_value_bytes(pValue);
-  if( nBlob<(int)sizeof(RtreeMatchArg) 
-   || ((nBlob-sizeof(RtreeMatchArg))%sizeof(double))!=0
-  ){
+  if( nBlob<(int)sizeof(RtreeMatchArg) ){
     return SQLITE_ERROR;
   }
 
-  pGeom = (sqlite3_rtree_geometry *)sqlite3_malloc(
-      sizeof(sqlite3_rtree_geometry) + nBlob
-  );
-  if( !pGeom ) return SQLITE_NOMEM;
-  memset(pGeom, 0, sizeof(sqlite3_rtree_geometry));
-  p = (RtreeMatchArg *)&pGeom[1];
+  pInfo = (sqlite3_rtree_query_info*)sqlite3_malloc( sizeof(*pInfo)+nBlob );
+  if( !pInfo ) return SQLITE_NOMEM;
+  memset(pInfo, 0, sizeof(*pInfo));
+  pBlob = (RtreeMatchArg*)&pInfo[1];
 
-  memcpy(p, sqlite3_value_blob(pValue), nBlob);
-  if( p->magic!=RTREE_GEOMETRY_MAGIC 
-   || nBlob!=(int)(sizeof(RtreeMatchArg) + (p->nParam-1)*sizeof(double))
-  ){
-    sqlite3_free(pGeom);
+  memcpy(pBlob, sqlite3_value_blob(pValue), nBlob);
+  nExpected = (int)(sizeof(RtreeMatchArg) +
+                    pBlob->nParam*sizeof(sqlite3_value*) +
+                    (pBlob->nParam-1)*sizeof(RtreeDValue));
+  if( pBlob->magic!=RTREE_GEOMETRY_MAGIC || nBlob!=nExpected ){
+    sqlite3_free(pInfo);
     return SQLITE_ERROR;
   }
+  pInfo->pContext = pBlob->cb.pContext;
+  pInfo->nParam = pBlob->nParam;
+  pInfo->aParam = pBlob->aParam;
+  pInfo->apSqlParam = pBlob->apSqlParam;
 
-  pGeom->pContext = p->pContext;
-  pGeom->nParam = p->nParam;
-  pGeom->aParam = p->aParam;
-
-  pCons->xGeom = p->xGeom;
-  pCons->pGeom = pGeom;
+  if( pBlob->cb.xGeom ){
+    pCons->u.xGeom = pBlob->cb.xGeom;
+  }else{
+    pCons->op = RTREE_QUERY;
+    pCons->u.xQueryFunc = pBlob->cb.xQueryFunc;
+  }
+  pCons->pInfo = pInfo;
   return SQLITE_OK;
 }
 
@@ -129067,44 +161488,59 @@ static int rtreeFilter(
 ){
   Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-
   RtreeNode *pRoot = 0;
   int ii;
   int rc = SQLITE_OK;
+  int iCell = 0;
 
   rtreeReference(pRtree);
 
+  /* Reset the cursor to the same state as rtreeOpen() leaves it in. */
   freeCursorConstraints(pCsr);
-  pCsr->iStrategy = idxNum;
+  sqlite3_free(pCsr->aPoint);
+  memset(pCsr, 0, sizeof(RtreeCursor));
+  pCsr->base.pVtab = (sqlite3_vtab*)pRtree;
 
+  pCsr->iStrategy = idxNum;
   if( idxNum==1 ){
     /* Special case - lookup by rowid. */
     RtreeNode *pLeaf;        /* Leaf on which the required cell resides */
+    RtreeSearchPoint *p;     /* Search point for the the leaf */
     i64 iRowid = sqlite3_value_int64(argv[0]);
-    rc = findLeafNode(pRtree, iRowid, &pLeaf);
-    pCsr->pNode = pLeaf; 
-    if( pLeaf ){
-      assert( rc==SQLITE_OK );
-      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &pCsr->iCell);
+    i64 iNode = 0;
+    rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);
+    if( rc==SQLITE_OK && pLeaf!=0 ){
+      p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);
+      assert( p!=0 );  /* Always returns pCsr->sPoint */
+      pCsr->aNode[0] = pLeaf;
+      p->id = iNode;
+      p->eWithin = PARTLY_WITHIN;
+      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);
+      p->iCell = iCell;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");
+    }else{
+      pCsr->atEOF = 1;
     }
   }else{
     /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 
     ** with the configured constraints. 
     */
-    if( argc>0 ){
+    rc = nodeAcquire(pRtree, 1, 0, &pRoot);
+    if( rc==SQLITE_OK && argc>0 ){
       pCsr->aConstraint = sqlite3_malloc(sizeof(RtreeConstraint)*argc);
       pCsr->nConstraint = argc;
       if( !pCsr->aConstraint ){
         rc = SQLITE_NOMEM;
       }else{
         memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);
+        memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));
         assert( (idxStr==0 && argc==0)
                 || (idxStr && (int)strlen(idxStr)==argc*2) );
         for(ii=0; ii<argc; ii++){
           RtreeConstraint *p = &pCsr->aConstraint[ii];
           p->op = idxStr[ii*2];
-          p->iCoord = idxStr[ii*2+1]-'a';
-          if( p->op==RTREE_MATCH ){
+          p->iCoord = idxStr[ii*2+1]-'0';
+          if( p->op>=RTREE_MATCH ){
             /* A MATCH operator. The right-hand-side must be a blob that
             ** can be cast into an RtreeMatchArg object. One created using
             ** an sqlite3_rtree_geometry_callback() SQL user function.
@@ -129113,42 +161549,53 @@ static int rtreeFilter(
             if( rc!=SQLITE_OK ){
               break;
             }
+            p->pInfo->nCoord = pRtree->nDim*2;
+            p->pInfo->anQueue = pCsr->anQueue;
+            p->pInfo->mxLevel = pRtree->iDepth + 1;
           }else{
-            p->rValue = sqlite3_value_double(argv[ii]);
+#ifdef SQLITE_RTREE_INT_ONLY
+            p->u.rValue = sqlite3_value_int64(argv[ii]);
+#else
+            p->u.rValue = sqlite3_value_double(argv[ii]);
+#endif
           }
         }
       }
     }
-  
     if( rc==SQLITE_OK ){
-      pCsr->pNode = 0;
-      rc = nodeAcquire(pRtree, 1, 0, &pRoot);
-    }
-    if( rc==SQLITE_OK ){
-      int isEof = 1;
-      int nCell = NCELL(pRoot);
-      pCsr->pNode = pRoot;
-      for(pCsr->iCell=0; rc==SQLITE_OK && pCsr->iCell<nCell; pCsr->iCell++){
-        assert( pCsr->pNode==pRoot );
-        rc = descendToCell(pRtree, pCsr, pRtree->iDepth, &isEof);
-        if( !isEof ){
-          break;
-        }
-      }
-      if( rc==SQLITE_OK && isEof ){
-        assert( pCsr->pNode==pRoot );
-        nodeRelease(pRtree, pRoot);
-        pCsr->pNode = 0;
-      }
-      assert( rc!=SQLITE_OK || !pCsr->pNode || pCsr->iCell<NCELL(pCsr->pNode) );
+      RtreeSearchPoint *pNew;
+      pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, pRtree->iDepth+1);
+      if( pNew==0 ) return SQLITE_NOMEM;
+      pNew->id = 1;
+      pNew->iCell = 0;
+      pNew->eWithin = PARTLY_WITHIN;
+      assert( pCsr->bPoint==1 );
+      pCsr->aNode[0] = pRoot;
+      pRoot = 0;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");
+      rc = rtreeStepToLeaf(pCsr);
     }
   }
 
+  nodeRelease(pRtree, pRoot);
   rtreeRelease(pRtree);
   return rc;
 }
 
 /*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void setEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+  if( sqlite3_libversion_number()>=3008002 ){
+    pIdxInfo->estimatedRows = nRow;
+  }
+#endif
+}
+
+/*
 ** Rtree virtual table module xBestIndex method. There are three
 ** table scan strategies to choose from (in order from most to 
 ** least desirable):
@@ -129183,19 +161630,33 @@ static int rtreeFilter(
 ** is 'a', the second from the left 'b' etc.
 */
 static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  Rtree *pRtree = (Rtree*)tab;
   int rc = SQLITE_OK;
   int ii;
+  int bMatch = 0;                 /* True if there exists a MATCH constraint */
+  i64 nRow;                       /* Estimated rows returned by this scan */
 
   int iIdx = 0;
   char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
   memset(zIdxStr, 0, sizeof(zIdxStr));
-  UNUSED_PARAMETER(tab);
+
+  /* Check if there exists a MATCH constraint - even an unusable one. If there
+  ** is, do not consider the lookup-by-rowid plan as using such a plan would
+  ** require the VDBE to evaluate the MATCH constraint, which is not currently
+  ** possible. */
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    if( pIdxInfo->aConstraint[ii].op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+      bMatch = 1;
+    }
+  }
 
   assert( pIdxInfo->idxStr==0 );
   for(ii=0; ii<pIdxInfo->nConstraint && iIdx<(int)(sizeof(zIdxStr)-1); ii++){
     struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];
 
-    if( p->usable && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+    if( bMatch==0 && p->usable 
+     && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
       /* We have an equality constraint on the rowid. Use strategy 1. */
       int jj;
       for(jj=0; jj<ii; jj++){
@@ -129209,9 +161670,11 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       /* This strategy involves a two rowid lookups on an B-Tree structures
       ** and then a linear search of an R-Tree node. This should be 
       ** considered almost as quick as a direct rowid lookup (for which 
-      ** sqlite uses an internal cost of 0.0).
+      ** sqlite uses an internal cost of 0.0). It is expected to return
+      ** a single row.
       */ 
-      pIdxInfo->estimatedCost = 10.0;
+      pIdxInfo->estimatedCost = 30.0;
+      setEstimatedRows(pIdxInfo, 1);
       return SQLITE_OK;
     }
 
@@ -129229,7 +161692,7 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
           break;
       }
       zIdxStr[iIdx++] = op;
-      zIdxStr[iIdx++] = p->iColumn - 1 + 'a';
+      zIdxStr[iIdx++] = p->iColumn - 1 + '0';
       pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);
       pIdxInfo->aConstraintUsage[ii].omit = 1;
     }
@@ -129240,19 +161703,22 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){
     return SQLITE_NOMEM;
   }
-  assert( iIdx>=0 );
-  pIdxInfo->estimatedCost = (2000000.0 / (double)(iIdx + 1));
+
+  nRow = pRtree->nRowEst >> (iIdx/2);
+  pIdxInfo->estimatedCost = (double)6.0 * (double)nRow;
+  setEstimatedRows(pIdxInfo, nRow);
+
   return rc;
 }
 
 /*
 ** Return the N-dimensional volumn of the cell stored in *p.
 */
-static float cellArea(Rtree *pRtree, RtreeCell *p){
-  float area = 1.0;
+static RtreeDValue cellArea(Rtree *pRtree, RtreeCell *p){
+  RtreeDValue area = (RtreeDValue)1;
   int ii;
   for(ii=0; ii<(pRtree->nDim*2); ii+=2){
-    area = (float)(area * (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii])));
+    area = (area * (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii])));
   }
   return area;
 }
@@ -129261,11 +161727,11 @@ static float cellArea(Rtree *pRtree, RtreeCell *p){
 ** Return the margin length of cell p. The margin length is the sum
 ** of the objects size in each dimension.
 */
-static float cellMargin(Rtree *pRtree, RtreeCell *p){
-  float margin = 0.0;
+static RtreeDValue cellMargin(Rtree *pRtree, RtreeCell *p){
+  RtreeDValue margin = (RtreeDValue)0;
   int ii;
   for(ii=0; ii<(pRtree->nDim*2); ii+=2){
-    margin += (float)(DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));
+    margin += (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));
   }
   return margin;
 }
@@ -129310,8 +161776,8 @@ static int cellContains(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){
 /*
 ** Return the amount cell p would grow by if it were unioned with pCell.
 */
-static float cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
-  float area;
+static RtreeDValue cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
+  RtreeDValue area;
   RtreeCell cell;
   memcpy(&cell, p, sizeof(RtreeCell));
   area = cellArea(pRtree, &cell);
@@ -129319,64 +161785,32 @@ static float cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
   return (cellArea(pRtree, &cell)-area);
 }
 
-#if VARIANT_RSTARTREE_CHOOSESUBTREE || VARIANT_RSTARTREE_SPLIT
-static float cellOverlap(
+static RtreeDValue cellOverlap(
   Rtree *pRtree, 
   RtreeCell *p, 
   RtreeCell *aCell, 
-  int nCell, 
-  int iExclude
+  int nCell
 ){
   int ii;
-  float overlap = 0.0;
+  RtreeDValue overlap = RTREE_ZERO;
   for(ii=0; ii<nCell; ii++){
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    if( ii!=iExclude )
-#else
-    assert( iExclude==-1 );
-    UNUSED_PARAMETER(iExclude);
-#endif
-    {
-      int jj;
-      float o = 1.0;
-      for(jj=0; jj<(pRtree->nDim*2); jj+=2){
-        double x1;
-        double x2;
-
-        x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
-        x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
-
-        if( x2<x1 ){
-          o = 0.0;
-          break;
-        }else{
-          o = o * (float)(x2-x1);
-        }
+    int jj;
+    RtreeDValue o = (RtreeDValue)1;
+    for(jj=0; jj<(pRtree->nDim*2); jj+=2){
+      RtreeDValue x1, x2;
+      x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
+      x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
+      if( x2<x1 ){
+        o = (RtreeDValue)0;
+        break;
+      }else{
+        o = o * (x2-x1);
       }
-      overlap += o;
     }
+    overlap += o;
   }
   return overlap;
 }
-#endif
-
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-static float cellOverlapEnlargement(
-  Rtree *pRtree, 
-  RtreeCell *p, 
-  RtreeCell *pInsert, 
-  RtreeCell *aCell, 
-  int nCell, 
-  int iExclude
-){
-  double before;
-  double after;
-  before = cellOverlap(pRtree, p, aCell, nCell, iExclude);
-  cellUnion(pRtree, p, pInsert);
-  after = cellOverlap(pRtree, p, aCell, nCell, iExclude);
-  return (float)(after-before);
-}
-#endif
 
 
 /*
@@ -129398,12 +161832,8 @@ static int ChooseLeaf(
     int iCell;
     sqlite3_int64 iBest = 0;
 
-    float fMinGrowth = 0.0;
-    float fMinArea = 0.0;
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    float fMinOverlap = 0.0;
-    float overlap;
-#endif
+    RtreeDValue fMinGrowth = RTREE_ZERO;
+    RtreeDValue fMinArea = RTREE_ZERO;
 
     int nCell = NCELL(pNode);
     RtreeCell cell;
@@ -129411,53 +161841,20 @@ static int ChooseLeaf(
 
     RtreeCell *aCell = 0;
 
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    if( ii==(pRtree->iDepth-1) ){
-      int jj;
-      aCell = sqlite3_malloc(sizeof(RtreeCell)*nCell);
-      if( !aCell ){
-        rc = SQLITE_NOMEM;
-        nodeRelease(pRtree, pNode);
-        pNode = 0;
-        continue;
-      }
-      for(jj=0; jj<nCell; jj++){
-        nodeGetCell(pRtree, pNode, jj, &aCell[jj]);
-      }
-    }
-#endif
-
     /* Select the child node which will be enlarged the least if pCell
     ** is inserted into it. Resolve ties by choosing the entry with
     ** the smallest area.
     */
     for(iCell=0; iCell<nCell; iCell++){
       int bBest = 0;
-      float growth;
-      float area;
+      RtreeDValue growth;
+      RtreeDValue area;
       nodeGetCell(pRtree, pNode, iCell, &cell);
       growth = cellGrowth(pRtree, &cell, pCell);
       area = cellArea(pRtree, &cell);
-
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-      if( ii==(pRtree->iDepth-1) ){
-        overlap = cellOverlapEnlargement(pRtree,&cell,pCell,aCell,nCell,iCell);
-      }else{
-        overlap = 0.0;
-      }
-      if( (iCell==0) 
-       || (overlap<fMinOverlap) 
-       || (overlap==fMinOverlap && growth<fMinGrowth)
-       || (overlap==fMinOverlap && growth==fMinGrowth && area<fMinArea)
-      ){
-        bBest = 1;
-        fMinOverlap = overlap;
-      }
-#else
       if( iCell==0||growth<fMinGrowth||(growth==fMinGrowth && area<fMinArea) ){
         bBest = 1;
       }
-#endif
       if( bBest ){
         fMinGrowth = growth;
         fMinArea = area;
@@ -129528,155 +161925,6 @@ static int parentWrite(Rtree *pRtree, sqlite3_int64 iNode, sqlite3_int64 iPar){
 
 static int rtreeInsertCell(Rtree *, RtreeNode *, RtreeCell *, int);
 
-#if VARIANT_GUTTMAN_LINEAR_SPLIT
-/*
-** Implementation of the linear variant of the PickNext() function from
-** Guttman[84].
-*/
-static RtreeCell *LinearPickNext(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  RtreeCell *pLeftBox, 
-  RtreeCell *pRightBox,
-  int *aiUsed
-){
-  int ii;
-  for(ii=0; aiUsed[ii]; ii++);
-  aiUsed[ii] = 1;
-  return &aCell[ii];
-}
-
-/*
-** Implementation of the linear variant of the PickSeeds() function from
-** Guttman[84].
-*/
-static void LinearPickSeeds(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  int *piLeftSeed, 
-  int *piRightSeed
-){
-  int i;
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  float maxNormalInnerWidth = 0.0;
-
-  /* Pick two "seed" cells from the array of cells. The algorithm used
-  ** here is the LinearPickSeeds algorithm from Gutman[1984]. The 
-  ** indices of the two seed cells in the array are stored in local
-  ** variables iLeftSeek and iRightSeed.
-  */
-  for(i=0; i<pRtree->nDim; i++){
-    float x1 = DCOORD(aCell[0].aCoord[i*2]);
-    float x2 = DCOORD(aCell[0].aCoord[i*2+1]);
-    float x3 = x1;
-    float x4 = x2;
-    int jj;
-
-    int iCellLeft = 0;
-    int iCellRight = 0;
-
-    for(jj=1; jj<nCell; jj++){
-      float left = DCOORD(aCell[jj].aCoord[i*2]);
-      float right = DCOORD(aCell[jj].aCoord[i*2+1]);
-
-      if( left<x1 ) x1 = left;
-      if( right>x4 ) x4 = right;
-      if( left>x3 ){
-        x3 = left;
-        iCellRight = jj;
-      }
-      if( right<x2 ){
-        x2 = right;
-        iCellLeft = jj;
-      }
-    }
-
-    if( x4!=x1 ){
-      float normalwidth = (x3 - x2) / (x4 - x1);
-      if( normalwidth>maxNormalInnerWidth ){
-        iLeftSeed = iCellLeft;
-        iRightSeed = iCellRight;
-      }
-    }
-  }
-
-  *piLeftSeed = iLeftSeed;
-  *piRightSeed = iRightSeed;
-}
-#endif /* VARIANT_GUTTMAN_LINEAR_SPLIT */
-
-#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
-/*
-** Implementation of the quadratic variant of the PickNext() function from
-** Guttman[84].
-*/
-static RtreeCell *QuadraticPickNext(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  RtreeCell *pLeftBox, 
-  RtreeCell *pRightBox,
-  int *aiUsed
-){
-  #define FABS(a) ((a)<0.0?-1.0*(a):(a))
-
-  int iSelect = -1;
-  float fDiff;
-  int ii;
-  for(ii=0; ii<nCell; ii++){
-    if( aiUsed[ii]==0 ){
-      float left = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
-      float right = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
-      float diff = FABS(right-left);
-      if( iSelect<0 || diff>fDiff ){
-        fDiff = diff;
-        iSelect = ii;
-      }
-    }
-  }
-  aiUsed[iSelect] = 1;
-  return &aCell[iSelect];
-}
-
-/*
-** Implementation of the quadratic variant of the PickSeeds() function from
-** Guttman[84].
-*/
-static void QuadraticPickSeeds(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  int *piLeftSeed, 
-  int *piRightSeed
-){
-  int ii;
-  int jj;
-
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  float fWaste = 0.0;
-
-  for(ii=0; ii<nCell; ii++){
-    for(jj=ii+1; jj<nCell; jj++){
-      float right = cellArea(pRtree, &aCell[jj]);
-      float growth = cellGrowth(pRtree, &aCell[ii], &aCell[jj]);
-      float waste = growth - right;
-
-      if( waste>fWaste ){
-        iLeftSeed = ii;
-        iRightSeed = jj;
-        fWaste = waste;
-      }
-    }
-  }
-
-  *piLeftSeed = iLeftSeed;
-  *piRightSeed = iRightSeed;
-}
-#endif /* VARIANT_GUTTMAN_QUADRATIC_SPLIT */
 
 /*
 ** Arguments aIdx, aDistance and aSpare all point to arrays of size
@@ -129698,7 +161946,7 @@ static void QuadraticPickSeeds(
 static void SortByDistance(
   int *aIdx, 
   int nIdx, 
-  float *aDistance, 
+  RtreeDValue *aDistance, 
   int *aSpare
 ){
   if( nIdx>1 ){
@@ -129724,8 +161972,8 @@ static void SortByDistance(
         aIdx[iLeft+iRight] = aLeft[iLeft];
         iLeft++;
       }else{
-        float fLeft = aDistance[aLeft[iLeft]];
-        float fRight = aDistance[aRight[iRight]];
+        RtreeDValue fLeft = aDistance[aLeft[iLeft]];
+        RtreeDValue fRight = aDistance[aRight[iRight]];
         if( fLeft<fRight ){
           aIdx[iLeft+iRight] = aLeft[iLeft];
           iLeft++;
@@ -129741,8 +161989,8 @@ static void SortByDistance(
     {
       int jj;
       for(jj=1; jj<nIdx; jj++){
-        float left = aDistance[aIdx[jj-1]];
-        float right = aDistance[aIdx[jj]];
+        RtreeDValue left = aDistance[aIdx[jj-1]];
+        RtreeDValue right = aDistance[aIdx[jj]];
         assert( left<=right );
       }
     }
@@ -129785,10 +162033,10 @@ static void SortByDimension(
     memcpy(aSpare, aLeft, sizeof(int)*nLeft);
     aLeft = aSpare;
     while( iLeft<nLeft || iRight<nRight ){
-      double xleft1 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2]);
-      double xleft2 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2+1]);
-      double xright1 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2]);
-      double xright2 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2+1]);
+      RtreeDValue xleft1 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2]);
+      RtreeDValue xleft2 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2+1]);
+      RtreeDValue xright1 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2]);
+      RtreeDValue xright2 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2+1]);
       if( (iLeft!=nLeft) && ((iRight==nRight)
        || (xleft1<xright1)
        || (xleft1==xright1 && xleft2<xright2)
@@ -129806,10 +162054,10 @@ static void SortByDimension(
     {
       int jj;
       for(jj=1; jj<nIdx; jj++){
-        float xleft1 = aCell[aIdx[jj-1]].aCoord[iDim*2];
-        float xleft2 = aCell[aIdx[jj-1]].aCoord[iDim*2+1];
-        float xright1 = aCell[aIdx[jj]].aCoord[iDim*2];
-        float xright2 = aCell[aIdx[jj]].aCoord[iDim*2+1];
+        RtreeDValue xleft1 = aCell[aIdx[jj-1]].aCoord[iDim*2];
+        RtreeDValue xleft2 = aCell[aIdx[jj-1]].aCoord[iDim*2+1];
+        RtreeDValue xright1 = aCell[aIdx[jj]].aCoord[iDim*2];
+        RtreeDValue xright2 = aCell[aIdx[jj]].aCoord[iDim*2+1];
         assert( xleft1<=xright1 && (xleft1<xright1 || xleft2<=xright2) );
       }
     }
@@ -129817,7 +162065,6 @@ static void SortByDimension(
   }
 }
 
-#if VARIANT_RSTARTREE_SPLIT
 /*
 ** Implementation of the R*-tree variant of SplitNode from Beckman[1990].
 */
@@ -129836,7 +162083,7 @@ static int splitNodeStartree(
 
   int iBestDim = 0;
   int iBestSplit = 0;
-  float fBestMargin = 0.0;
+  RtreeDValue fBestMargin = RTREE_ZERO;
 
   int nByte = (pRtree->nDim+1)*(sizeof(int*)+nCell*sizeof(int));
 
@@ -129857,9 +162104,9 @@ static int splitNodeStartree(
   }
 
   for(ii=0; ii<pRtree->nDim; ii++){
-    float margin = 0.0;
-    float fBestOverlap = 0.0;
-    float fBestArea = 0.0;
+    RtreeDValue margin = RTREE_ZERO;
+    RtreeDValue fBestOverlap = RTREE_ZERO;
+    RtreeDValue fBestArea = RTREE_ZERO;
     int iBestLeft = 0;
     int nLeft;
 
@@ -129871,8 +162118,8 @@ static int splitNodeStartree(
       RtreeCell left;
       RtreeCell right;
       int kk;
-      float overlap;
-      float area;
+      RtreeDValue overlap;
+      RtreeDValue area;
 
       memcpy(&left, &aCell[aaSorted[ii][0]], sizeof(RtreeCell));
       memcpy(&right, &aCell[aaSorted[ii][nCell-1]], sizeof(RtreeCell));
@@ -129885,7 +162132,7 @@ static int splitNodeStartree(
       }
       margin += cellMargin(pRtree, &left);
       margin += cellMargin(pRtree, &right);
-      overlap = cellOverlap(pRtree, &left, &right, 1, -1);
+      overlap = cellOverlap(pRtree, &left, &right, 1);
       area = cellArea(pRtree, &left) + cellArea(pRtree, &right);
       if( (nLeft==RTREE_MINCELLS(pRtree))
        || (overlap<fBestOverlap)
@@ -129917,63 +162164,7 @@ static int splitNodeStartree(
   sqlite3_free(aaSorted);
   return SQLITE_OK;
 }
-#endif
-
-#if VARIANT_GUTTMAN_SPLIT
-/*
-** Implementation of the regular R-tree SplitNode from Guttman[1984].
-*/
-static int splitNodeGuttman(
-  Rtree *pRtree,
-  RtreeCell *aCell,
-  int nCell,
-  RtreeNode *pLeft,
-  RtreeNode *pRight,
-  RtreeCell *pBboxLeft,
-  RtreeCell *pBboxRight
-){
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  int *aiUsed;
-  int i;
 
-  aiUsed = sqlite3_malloc(sizeof(int)*nCell);
-  if( !aiUsed ){
-    return SQLITE_NOMEM;
-  }
-  memset(aiUsed, 0, sizeof(int)*nCell);
-
-  PickSeeds(pRtree, aCell, nCell, &iLeftSeed, &iRightSeed);
-
-  memcpy(pBboxLeft, &aCell[iLeftSeed], sizeof(RtreeCell));
-  memcpy(pBboxRight, &aCell[iRightSeed], sizeof(RtreeCell));
-  nodeInsertCell(pRtree, pLeft, &aCell[iLeftSeed]);
-  nodeInsertCell(pRtree, pRight, &aCell[iRightSeed]);
-  aiUsed[iLeftSeed] = 1;
-  aiUsed[iRightSeed] = 1;
-
-  for(i=nCell-2; i>0; i--){
-    RtreeCell *pNext;
-    pNext = PickNext(pRtree, aCell, nCell, pBboxLeft, pBboxRight, aiUsed);
-    float diff =  
-      cellGrowth(pRtree, pBboxLeft, pNext) - 
-      cellGrowth(pRtree, pBboxRight, pNext)
-    ;
-    if( (RTREE_MINCELLS(pRtree)-NCELL(pRight)==i)
-     || (diff>0.0 && (RTREE_MINCELLS(pRtree)-NCELL(pLeft)!=i))
-    ){
-      nodeInsertCell(pRtree, pRight, pNext);
-      cellUnion(pRtree, pBboxRight, pNext);
-    }else{
-      nodeInsertCell(pRtree, pLeft, pNext);
-      cellUnion(pRtree, pBboxLeft, pNext);
-    }
-  }
-
-  sqlite3_free(aiUsed);
-  return SQLITE_OK;
-}
-#endif
 
 static int updateMapping(
   Rtree *pRtree, 
@@ -130051,7 +162242,8 @@ static int SplitNode(
   memset(pLeft->zData, 0, pRtree->iNodeSize);
   memset(pRight->zData, 0, pRtree->iNodeSize);
 
-  rc = AssignCells(pRtree, aCell, nCell, pLeft, pRight, &leftbbox, &rightbbox);
+  rc = splitNodeStartree(pRtree, aCell, nCell, pLeft, pRight,
+                         &leftbbox, &rightbbox);
   if( rc!=SQLITE_OK ){
     goto splitnode_out;
   }
@@ -130288,32 +162480,34 @@ static int Reinsert(
   int *aOrder;
   int *aSpare;
   RtreeCell *aCell;
-  float *aDistance;
+  RtreeDValue *aDistance;
   int nCell;
-  float aCenterCoord[RTREE_MAX_DIMENSIONS];
+  RtreeDValue aCenterCoord[RTREE_MAX_DIMENSIONS];
   int iDim;
   int ii;
   int rc = SQLITE_OK;
+  int n;
 
-  memset(aCenterCoord, 0, sizeof(float)*RTREE_MAX_DIMENSIONS);
+  memset(aCenterCoord, 0, sizeof(RtreeDValue)*RTREE_MAX_DIMENSIONS);
 
   nCell = NCELL(pNode)+1;
+  n = (nCell+1)&(~1);
 
   /* Allocate the buffers used by this operation. The allocation is
   ** relinquished before this function returns.
   */
-  aCell = (RtreeCell *)sqlite3_malloc(nCell * (
-    sizeof(RtreeCell) +         /* aCell array */
-    sizeof(int)       +         /* aOrder array */
-    sizeof(int)       +         /* aSpare array */
-    sizeof(float)               /* aDistance array */
+  aCell = (RtreeCell *)sqlite3_malloc(n * (
+    sizeof(RtreeCell)     +         /* aCell array */
+    sizeof(int)           +         /* aOrder array */
+    sizeof(int)           +         /* aSpare array */
+    sizeof(RtreeDValue)             /* aDistance array */
   ));
   if( !aCell ){
     return SQLITE_NOMEM;
   }
-  aOrder    = (int *)&aCell[nCell];
-  aSpare    = (int *)&aOrder[nCell];
-  aDistance = (float *)&aSpare[nCell];
+  aOrder    = (int *)&aCell[n];
+  aSpare    = (int *)&aOrder[n];
+  aDistance = (RtreeDValue *)&aSpare[n];
 
   for(ii=0; ii<nCell; ii++){
     if( ii==(nCell-1) ){
@@ -130323,19 +162517,19 @@ static int Reinsert(
     }
     aOrder[ii] = ii;
     for(iDim=0; iDim<pRtree->nDim; iDim++){
-      aCenterCoord[iDim] += (float)DCOORD(aCell[ii].aCoord[iDim*2]);
-      aCenterCoord[iDim] += (float)DCOORD(aCell[ii].aCoord[iDim*2+1]);
+      aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2]);
+      aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2+1]);
     }
   }
   for(iDim=0; iDim<pRtree->nDim; iDim++){
-    aCenterCoord[iDim] = (float)(aCenterCoord[iDim]/((float)nCell*2.0));
+    aCenterCoord[iDim] = (aCenterCoord[iDim]/(nCell*(RtreeDValue)2));
   }
 
   for(ii=0; ii<nCell; ii++){
-    aDistance[ii] = 0.0;
+    aDistance[ii] = RTREE_ZERO;
     for(iDim=0; iDim<pRtree->nDim; iDim++){
-      float coord = (float)(DCOORD(aCell[ii].aCoord[iDim*2+1]) - 
-          DCOORD(aCell[ii].aCoord[iDim*2]));
+      RtreeDValue coord = (DCOORD(aCell[ii].aCoord[iDim*2+1]) - 
+                               DCOORD(aCell[ii].aCoord[iDim*2]));
       aDistance[ii] += (coord-aCenterCoord[iDim])*(coord-aCenterCoord[iDim]);
     }
   }
@@ -130398,16 +162592,12 @@ static int rtreeInsertCell(
     }
   }
   if( nodeInsertCell(pRtree, pNode, pCell) ){
-#if VARIANT_RSTARTREE_REINSERT
     if( iHeight<=pRtree->iReinsertHeight || pNode->iNode==1){
       rc = SplitNode(pRtree, pNode, pCell, iHeight);
     }else{
       pRtree->iReinsertHeight = iHeight;
       rc = Reinsert(pRtree, pNode, pCell, iHeight);
     }
-#else
-    rc = SplitNode(pRtree, pNode, pCell, iHeight);
-#endif
   }else{
     rc = AdjustTree(pRtree, pNode, pCell);
     if( rc==SQLITE_OK ){
@@ -130465,19 +162655,19 @@ static int newRowid(Rtree *pRtree, i64 *piRowid){
 */
 static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
   int rc;                         /* Return code */
-  RtreeNode *pLeaf;               /* Leaf node containing record iDelete */
+  RtreeNode *pLeaf = 0;           /* Leaf node containing record iDelete */
   int iCell;                      /* Index of iDelete cell in pLeaf */
   RtreeNode *pRoot;               /* Root node of rtree structure */
 
 
-  /* Obtain a reference to the root node to initialise Rtree.iDepth */
+  /* Obtain a reference to the root node to initialize Rtree.iDepth */
   rc = nodeAcquire(pRtree, 1, 0, &pRoot);
 
   /* Obtain a reference to the leaf node that contains the entry 
   ** about to be deleted. 
   */
   if( rc==SQLITE_OK ){
-    rc = findLeafNode(pRtree, iDelete, &pLeaf);
+    rc = findLeafNode(pRtree, iDelete, &pLeaf, 0);
   }
 
   /* Delete the cell in question from the leaf node. */
@@ -130545,6 +162735,83 @@ static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
 }
 
 /*
+** Rounding constants for float->double conversion.
+*/
+#define RNDTOWARDS  (1.0 - 1.0/8388608.0)  /* Round towards zero */
+#define RNDAWAY     (1.0 + 1.0/8388608.0)  /* Round away from zero */
+
+#if !defined(SQLITE_RTREE_INT_ONLY)
+/*
+** Convert an sqlite3_value into an RtreeValue (presumably a float)
+** while taking care to round toward negative or positive, respectively.
+*/
+static RtreeValue rtreeValueDown(sqlite3_value *v){
+  double d = sqlite3_value_double(v);
+  float f = (float)d;
+  if( f>d ){
+    f = (float)(d*(d<0 ? RNDAWAY : RNDTOWARDS));
+  }
+  return f;
+}
+static RtreeValue rtreeValueUp(sqlite3_value *v){
+  double d = sqlite3_value_double(v);
+  float f = (float)d;
+  if( f<d ){
+    f = (float)(d*(d<0 ? RNDTOWARDS : RNDAWAY));
+  }
+  return f;
+}
+#endif /* !defined(SQLITE_RTREE_INT_ONLY) */
+
+/*
+** A constraint has failed while inserting a row into an rtree table. 
+** Assuming no OOM error occurs, this function sets the error message 
+** (at pRtree->base.zErrMsg) to an appropriate value and returns
+** SQLITE_CONSTRAINT.
+**
+** Parameter iCol is the index of the leftmost column involved in the
+** constraint failure. If it is 0, then the constraint that failed is
+** the unique constraint on the id column. Otherwise, it is the rtree
+** (c1<=c2) constraint on columns iCol and iCol+1 that has failed.
+**
+** If an OOM occurs, SQLITE_NOMEM is returned instead of SQLITE_CONSTRAINT.
+*/
+static int rtreeConstraintError(Rtree *pRtree, int iCol){
+  sqlite3_stmt *pStmt = 0;
+  char *zSql; 
+  int rc;
+
+  assert( iCol==0 || iCol%2 );
+  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", pRtree->zDb, pRtree->zName);
+  if( zSql ){
+    rc = sqlite3_prepare_v2(pRtree->db, zSql, -1, &pStmt, 0);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3_free(zSql);
+
+  if( rc==SQLITE_OK ){
+    if( iCol==0 ){
+      const char *zCol = sqlite3_column_name(pStmt, 0);
+      pRtree->base.zErrMsg = sqlite3_mprintf(
+          "UNIQUE constraint failed: %s.%s", pRtree->zName, zCol
+      );
+    }else{
+      const char *zCol1 = sqlite3_column_name(pStmt, iCol);
+      const char *zCol2 = sqlite3_column_name(pStmt, iCol+1);
+      pRtree->base.zErrMsg = sqlite3_mprintf(
+          "rtree constraint failed: %s.(%s<=%s)", pRtree->zName, zCol1, zCol2
+      );
+    }
+  }
+
+  sqlite3_finalize(pStmt);
+  return (rc==SQLITE_OK ? SQLITE_CONSTRAINT : rc);
+}
+
+
+
+/*
 ** The xUpdate method for rtree module virtual tables.
 */
 static int rtreeUpdate(
@@ -130561,6 +162828,8 @@ static int rtreeUpdate(
   rtreeReference(pRtree);
   assert(nData>=1);
 
+  cell.iRowid = 0;  /* Used only to suppress a compiler warning */
+
   /* Constraint handling. A write operation on an r-tree table may return
   ** SQLITE_CONSTRAINT for two reasons:
   **
@@ -130575,23 +162844,34 @@ static int rtreeUpdate(
   if( nData>1 ){
     int ii;
 
-    /* Populate the cell.aCoord[] array. The first coordinate is azData[3]. */
-    assert( nData==(pRtree->nDim*2 + 3) );
+    /* Populate the cell.aCoord[] array. The first coordinate is azData[3].
+    **
+    ** NB: nData can only be less than nDim*2+3 if the rtree is mis-declared
+    ** with "column" that are interpreted as table constraints.
+    ** Example:  CREATE VIRTUAL TABLE bad USING rtree(x,y,CHECK(y>5));
+    ** This problem was discovered after years of use, so we silently ignore
+    ** these kinds of misdeclared tables to avoid breaking any legacy.
+    */
+    assert( nData<=(pRtree->nDim*2 + 3) );
+
+#ifndef SQLITE_RTREE_INT_ONLY
     if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
-      for(ii=0; ii<(pRtree->nDim*2); ii+=2){
-        cell.aCoord[ii].f = (float)sqlite3_value_double(azData[ii+3]);
-        cell.aCoord[ii+1].f = (float)sqlite3_value_double(azData[ii+4]);
+      for(ii=0; ii<nData-4; ii+=2){
+        cell.aCoord[ii].f = rtreeValueDown(azData[ii+3]);
+        cell.aCoord[ii+1].f = rtreeValueUp(azData[ii+4]);
         if( cell.aCoord[ii].f>cell.aCoord[ii+1].f ){
-          rc = SQLITE_CONSTRAINT;
+          rc = rtreeConstraintError(pRtree, ii+1);
           goto constraint;
         }
       }
-    }else{
-      for(ii=0; ii<(pRtree->nDim*2); ii+=2){
+    }else
+#endif
+    {
+      for(ii=0; ii<nData-4; ii+=2){
         cell.aCoord[ii].i = sqlite3_value_int(azData[ii+3]);
         cell.aCoord[ii+1].i = sqlite3_value_int(azData[ii+4]);
         if( cell.aCoord[ii].i>cell.aCoord[ii+1].i ){
-          rc = SQLITE_CONSTRAINT;
+          rc = rtreeConstraintError(pRtree, ii+1);
           goto constraint;
         }
       }
@@ -130612,7 +162892,7 @@ static int rtreeUpdate(
           if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){
             rc = rtreeDeleteRowid(pRtree, cell.iRowid);
           }else{
-            rc = SQLITE_CONSTRAINT;
+            rc = rtreeConstraintError(pRtree, 0);
             goto constraint;
           }
         }
@@ -130635,7 +162915,7 @@ static int rtreeUpdate(
   */
   if( rc==SQLITE_OK && nData>1 ){
     /* Insert the new record into the r-tree */
-    RtreeNode *pLeaf;
+    RtreeNode *pLeaf = 0;
 
     /* Figure out the rowid of the new row. */
     if( bHaveRowid==0 ){
@@ -130683,6 +162963,48 @@ static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
   return rc;
 }
 
+/*
+** This function populates the pRtree->nRowEst variable with an estimate
+** of the number of rows in the virtual table. If possible, this is based
+** on sqlite_stat1 data. Otherwise, use RTREE_DEFAULT_ROWEST.
+*/
+static int rtreeQueryStat1(sqlite3 *db, Rtree *pRtree){
+  const char *zFmt = "SELECT stat FROM %Q.sqlite_stat1 WHERE tbl = '%q_rowid'";
+  char *zSql;
+  sqlite3_stmt *p;
+  int rc;
+  i64 nRow = 0;
+
+  if( sqlite3_table_column_metadata(db,pRtree->zDb,"sqlite_stat1",
+          0,0,0,0,0,0)==SQLITE_ERROR ){
+    pRtree->nRowEst = RTREE_DEFAULT_ROWEST;
+    return SQLITE_OK;
+  }
+  zSql = sqlite3_mprintf(zFmt, pRtree->zDb, pRtree->zName);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare_v2(db, zSql, -1, &p, 0);
+    if( rc==SQLITE_OK ){
+      if( sqlite3_step(p)==SQLITE_ROW ) nRow = sqlite3_column_int64(p, 0);
+      rc = sqlite3_finalize(p);
+    }else if( rc!=SQLITE_NOMEM ){
+      rc = SQLITE_OK;
+    }
+
+    if( rc==SQLITE_OK ){
+      if( nRow==0 ){
+        pRtree->nRowEst = RTREE_DEFAULT_ROWEST;
+      }else{
+        pRtree->nRowEst = MAX(nRow, RTREE_MIN_ROWEST);
+      }
+    }
+    sqlite3_free(zSql);
+  }
+
+  return rc;
+}
+
 static sqlite3_module rtreeModule = {
   0,                          /* iVersion */
   rtreeCreate,                /* xCreate - create a table */
@@ -130744,7 +163066,8 @@ static int rtreeSqlInit(
     char *zCreate = sqlite3_mprintf(
 "CREATE TABLE \"%w\".\"%w_node\"(nodeno INTEGER PRIMARY KEY, data BLOB);"
 "CREATE TABLE \"%w\".\"%w_rowid\"(rowid INTEGER PRIMARY KEY, nodeno INTEGER);"
-"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY, parentnode INTEGER);"
+"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY,"
+                                  " parentnode INTEGER);"
 "INSERT INTO '%q'.'%q_node' VALUES(1, zeroblob(%d))",
       zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, pRtree->iNodeSize
     );
@@ -130768,6 +163091,7 @@ static int rtreeSqlInit(
   appStmt[7] = &pRtree->pWriteParent;
   appStmt[8] = &pRtree->pDeleteParent;
 
+  rc = rtreeQueryStat1(db, pRtree);
   for(i=0; i<N_STATEMENT && rc==SQLITE_OK; i++){
     char *zSql = sqlite3_mprintf(azSql[i], zDb, zPrefix);
     if( zSql ){
@@ -130821,7 +163145,8 @@ static int getIntFromStmt(sqlite3 *db, const char *zSql, int *piVal){
 static int getNodeSize(
   sqlite3 *db,                    /* Database handle */
   Rtree *pRtree,                  /* Rtree handle */
-  int isCreate                    /* True for xCreate, false for xConnect */
+  int isCreate,                   /* True for xCreate, false for xConnect */
+  char **pzErr                    /* OUT: Error message, if any */
 ){
   int rc;
   char *zSql;
@@ -130834,6 +163159,8 @@ static int getNodeSize(
       if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)<pRtree->iNodeSize ){
         pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;
       }
+    }else{
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
     }
   }else{
     zSql = sqlite3_mprintf(
@@ -130841,6 +163168,9 @@ static int getNodeSize(
         pRtree->zDb, pRtree->zName
     );
     rc = getIntFromStmt(db, zSql, &pRtree->iNodeSize);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    }
   }
 
   sqlite3_free(zSql);
@@ -130886,8 +163216,8 @@ static int rtreeInit(
   sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
 
   /* Allocate the sqlite3_vtab structure */
-  nDb = strlen(argv[1]);
-  nName = strlen(argv[2]);
+  nDb = (int)strlen(argv[1]);
+  nName = (int)strlen(argv[2]);
   pRtree = (Rtree *)sqlite3_malloc(sizeof(Rtree)+nDb+nName+2);
   if( !pRtree ){
     return SQLITE_NOMEM;
@@ -130904,7 +163234,7 @@ static int rtreeInit(
   memcpy(pRtree->zName, argv[2], nName);
 
   /* Figure out the node size to use. */
-  rc = getNodeSize(db, pRtree, isCreate);
+  rc = getNodeSize(db, pRtree, isCreate, pzErr);
 
   /* Create/Connect to the underlying relational database schema. If
   ** that is successful, call sqlite3_declare_vtab() to configure
@@ -130939,6 +163269,8 @@ static int rtreeInit(
   if( rc==SQLITE_OK ){
     *ppVtab = (sqlite3_vtab *)pRtree;
   }else{
+    assert( *ppVtab==0 );
+    assert( pRtree->nBusy==1 );
     rtreeRelease(pRtree);
   }
   return rc;
@@ -130949,10 +163281,10 @@ static int rtreeInit(
 ** Implementation of a scalar function that decodes r-tree nodes to
 ** human readable strings. This can be used for debugging and analysis.
 **
-** The scalar function takes two arguments, a blob of data containing
-** an r-tree node, and the number of dimensions the r-tree indexes.
-** For a two-dimensional r-tree structure called "rt", to deserialize
-** all nodes, a statement like:
+** The scalar function takes two arguments: (1) the number of dimensions
+** to the rtree (between 1 and 5, inclusive) and (2) a blob of data containing
+** an r-tree node.  For a two-dimensional r-tree structure called "rt", to
+** deserialize all nodes, a statement like:
 **
 **   SELECT rtreenode(2, data) FROM rt_node;
 **
@@ -130982,10 +163314,16 @@ static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
 
     nodeGetCell(&tree, &node, ii, &cell);
     sqlite3_snprintf(512-nCell,&zCell[nCell],"%lld", cell.iRowid);
-    nCell = strlen(zCell);
+    nCell = (int)strlen(zCell);
     for(jj=0; jj<tree.nDim*2; jj++){
-      sqlite3_snprintf(512-nCell,&zCell[nCell]," %f",(double)cell.aCoord[jj].f);
-      nCell = strlen(zCell);
+#ifndef SQLITE_RTREE_INT_ONLY
+      sqlite3_snprintf(512-nCell,&zCell[nCell], " %g",
+                       (double)cell.aCoord[jj].f);
+#else
+      sqlite3_snprintf(512-nCell,&zCell[nCell], " %d",
+                       cell.aCoord[jj].i);
+#endif
+      nCell = (int)strlen(zCell);
     }
 
     if( zText ){
@@ -131000,6 +163338,15 @@ static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
   sqlite3_result_text(ctx, zText, -1, sqlite3_free);
 }
 
+/* This routine implements an SQL function that returns the "depth" parameter
+** from the front of a blob that is an r-tree node.  For example:
+**
+**     SELECT rtreedepth(data) FROM rt_node WHERE nodeno=1;
+**
+** The depth value is 0 for all nodes other than the root node, and the root
+** node always has nodeno=1, so the example above is the primary use for this
+** routine.  This routine is intended for testing and analysis only.
+*/
 static void rtreedepth(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
   UNUSED_PARAMETER(nArg);
   if( sqlite3_value_type(apArg[0])!=SQLITE_BLOB 
@@ -131026,7 +163373,11 @@ SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db){
     rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
   }
   if( rc==SQLITE_OK ){
+#ifdef SQLITE_RTREE_INT_ONLY
+    void *c = (void *)RTREE_COORD_INT32;
+#else
     void *c = (void *)RTREE_COORD_REAL32;
+#endif
     rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);
   }
   if( rc==SQLITE_OK ){
@@ -131038,53 +163389,87 @@ SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db){
 }
 
 /*
-** A version of sqlite3_free() that can be used as a callback. This is used
-** in two places - as the destructor for the blob value returned by the
-** invocation of a geometry function, and as the destructor for the geometry
-** functions themselves.
+** This routine deletes the RtreeGeomCallback object that was attached
+** one of the SQL functions create by sqlite3_rtree_geometry_callback()
+** or sqlite3_rtree_query_callback().  In other words, this routine is the
+** destructor for an RtreeGeomCallback objecct.  This routine is called when
+** the corresponding SQL function is deleted.
+*/
+static void rtreeFreeCallback(void *p){
+  RtreeGeomCallback *pInfo = (RtreeGeomCallback*)p;
+  if( pInfo->xDestructor ) pInfo->xDestructor(pInfo->pContext);
+  sqlite3_free(p);
+}
+
+/*
+** This routine frees the BLOB that is returned by geomCallback().
 */
-static void doSqlite3Free(void *p){
+static void rtreeMatchArgFree(void *pArg){
+  int i;
+  RtreeMatchArg *p = (RtreeMatchArg*)pArg;
+  for(i=0; i<p->nParam; i++){
+    sqlite3_value_free(p->apSqlParam[i]);
+  }
   sqlite3_free(p);
 }
 
 /*
-** Each call to sqlite3_rtree_geometry_callback() creates an ordinary SQLite
-** scalar user function. This C function is the callback used for all such
-** registered SQL functions.
+** Each call to sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback() creates an ordinary SQLite
+** scalar function that is implemented by this routine.
+**
+** All this function does is construct an RtreeMatchArg object that
+** contains the geometry-checking callback routines and a list of
+** parameters to this function, then return that RtreeMatchArg object
+** as a BLOB.
 **
-** The scalar user functions return a blob that is interpreted by r-tree
-** table MATCH operators.
+** The R-Tree MATCH operator will read the returned BLOB, deserialize
+** the RtreeMatchArg object, and use the RtreeMatchArg object to figure
+** out which elements of the R-Tree should be returned by the query.
 */
 static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
   RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);
   RtreeMatchArg *pBlob;
   int nBlob;
+  int memErr = 0;
 
-  nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(double);
+  nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(RtreeDValue)
+           + nArg*sizeof(sqlite3_value*);
   pBlob = (RtreeMatchArg *)sqlite3_malloc(nBlob);
   if( !pBlob ){
     sqlite3_result_error_nomem(ctx);
   }else{
     int i;
     pBlob->magic = RTREE_GEOMETRY_MAGIC;
-    pBlob->xGeom = pGeomCtx->xGeom;
-    pBlob->pContext = pGeomCtx->pContext;
+    pBlob->cb = pGeomCtx[0];
+    pBlob->apSqlParam = (sqlite3_value**)&pBlob->aParam[nArg];
     pBlob->nParam = nArg;
     for(i=0; i<nArg; i++){
+      pBlob->apSqlParam[i] = sqlite3_value_dup(aArg[i]);
+      if( pBlob->apSqlParam[i]==0 ) memErr = 1;
+#ifdef SQLITE_RTREE_INT_ONLY
+      pBlob->aParam[i] = sqlite3_value_int64(aArg[i]);
+#else
       pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
+#endif
+    }
+    if( memErr ){
+      sqlite3_result_error_nomem(ctx);
+      rtreeMatchArgFree(pBlob);
+    }else{
+      sqlite3_result_blob(ctx, pBlob, nBlob, rtreeMatchArgFree);
     }
-    sqlite3_result_blob(ctx, pBlob, nBlob, doSqlite3Free);
   }
 }
 
 /*
 ** Register a new geometry function for use with the r-tree MATCH operator.
 */
-SQLITE_API int sqlite3_rtree_geometry_callback(
-  sqlite3 *db,
-  const char *zGeom,
-  int (*xGeom)(sqlite3_rtree_geometry *, int, double *, int *),
-  void *pContext
+SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback(
+  sqlite3 *db,                  /* Register SQL function on this connection */
+  const char *zGeom,            /* Name of the new SQL function */
+  int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*), /* Callback */
+  void *pContext                /* Extra data associated with the callback */
 ){
   RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
 
@@ -131092,17 +163477,44 @@ SQLITE_API int sqlite3_rtree_geometry_callback(
   pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
   if( !pGeomCtx ) return SQLITE_NOMEM;
   pGeomCtx->xGeom = xGeom;
+  pGeomCtx->xQueryFunc = 0;
+  pGeomCtx->xDestructor = 0;
   pGeomCtx->pContext = pContext;
-
-  /* Create the new user-function. Register a destructor function to delete
-  ** the context object when it is no longer required.  */
   return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY, 
-      (void *)pGeomCtx, geomCallback, 0, 0, doSqlite3Free
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
+  );
+}
+
+/*
+** Register a new 2nd-generation geometry function for use with the
+** r-tree MATCH operator.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback(
+  sqlite3 *db,                 /* Register SQL function on this connection */
+  const char *zQueryFunc,      /* Name of new SQL function */
+  int (*xQueryFunc)(sqlite3_rtree_query_info*), /* Callback */
+  void *pContext,              /* Extra data passed into the callback */
+  void (*xDestructor)(void*)   /* Destructor for the extra data */
+){
+  RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
+
+  /* Allocate and populate the context object. */
+  pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
+  if( !pGeomCtx ) return SQLITE_NOMEM;
+  pGeomCtx->xGeom = 0;
+  pGeomCtx->xQueryFunc = xQueryFunc;
+  pGeomCtx->xDestructor = xDestructor;
+  pGeomCtx->pContext = pContext;
+  return sqlite3_create_function_v2(db, zQueryFunc, -1, SQLITE_ANY, 
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
   );
 }
 
 #if !SQLITE_CORE
-SQLITE_API int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_rtree_init(
   sqlite3 *db,
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
@@ -131140,7 +163552,7 @@ SQLITE_API int sqlite3_extension_init(
 **   * Implementations of the SQL scalar upper() and lower() functions
 **     for case mapping.
 **
-**   * Integration of ICU and SQLite collation seqences.
+**   * Integration of ICU and SQLite collation sequences.
 **
 **   * An implementation of the LIKE operator that uses ICU to 
 **     provide case-independent matching.
@@ -131157,8 +163569,10 @@ SQLITE_API int sqlite3_extension_init(
 /* #include <assert.h> */
 
 #ifndef SQLITE_CORE
+/*   #include "sqlite3ext.h" */
   SQLITE_EXTENSION_INIT1
 #else
+/*   #include "sqlite3.h" */
 #endif
 
 /*
@@ -131177,6 +163591,38 @@ static void xFree(void *p){
 }
 
 /*
+** This lookup table is used to help decode the first byte of
+** a multi-byte UTF8 character. It is copied here from SQLite source
+** code file utf8.c.
+*/
+static const unsigned char icuUtf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+
+#define SQLITE_ICU_READ_UTF8(zIn, c)                       \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = icuUtf8Trans1[c-0xc0];                             \
+    while( (*zIn & 0xc0)==0x80 ){                          \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+  }
+
+#define SQLITE_ICU_SKIP_UTF8(zIn)                          \
+  assert( *zIn );                                          \
+  if( *(zIn++)>=0xc0 ){                                    \
+    while( (*zIn & 0xc0)==0x80 ){zIn++;}                   \
+  }
+
+
+/*
 ** Compare two UTF-8 strings for equality where the first string is
 ** a "LIKE" expression. Return true (1) if they are the same and 
 ** false (0) if they are different.
@@ -131189,17 +163635,14 @@ static int icuLikeCompare(
   static const int MATCH_ONE = (UChar32)'_';
   static const int MATCH_ALL = (UChar32)'%';
 
-  int iPattern = 0;       /* Current byte index in zPattern */
-  int iString = 0;        /* Current byte index in zString */
-
   int prevEscape = 0;     /* True if the previous character was uEsc */
 
-  while( zPattern[iPattern]!=0 ){
+  while( 1 ){
 
     /* Read (and consume) the next character from the input pattern. */
     UChar32 uPattern;
-    U8_NEXT_UNSAFE(zPattern, iPattern, uPattern);
-    assert(uPattern!=0);
+    SQLITE_ICU_READ_UTF8(zPattern, uPattern);
+    if( uPattern==0 ) break;
 
     /* There are now 4 possibilities:
     **
@@ -131216,28 +163659,28 @@ static int icuLikeCompare(
       ** MATCH_ALL. For each MATCH_ONE, skip one character in the 
       ** test string.
       */
-      while( (c=zPattern[iPattern]) == MATCH_ALL || c == MATCH_ONE ){
+      while( (c=*zPattern) == MATCH_ALL || c == MATCH_ONE ){
         if( c==MATCH_ONE ){
-          if( zString[iString]==0 ) return 0;
-          U8_FWD_1_UNSAFE(zString, iString);
+          if( *zString==0 ) return 0;
+          SQLITE_ICU_SKIP_UTF8(zString);
         }
-        iPattern++;
+        zPattern++;
       }
 
-      if( zPattern[iPattern]==0 ) return 1;
+      if( *zPattern==0 ) return 1;
 
-      while( zString[iString] ){
-        if( icuLikeCompare(&zPattern[iPattern], &zString[iString], uEsc) ){
+      while( *zString ){
+        if( icuLikeCompare(zPattern, zString, uEsc) ){
           return 1;
         }
-        U8_FWD_1_UNSAFE(zString, iString);
+        SQLITE_ICU_SKIP_UTF8(zString);
       }
       return 0;
 
     }else if( !prevEscape && uPattern==MATCH_ONE ){
       /* Case 2. */
-      if( zString[iString]==0 ) return 0;
-      U8_FWD_1_UNSAFE(zString, iString);
+      if( *zString==0 ) return 0;
+      SQLITE_ICU_SKIP_UTF8(zString);
 
     }else if( !prevEscape && uPattern==uEsc){
       /* Case 3. */
@@ -131246,7 +163689,7 @@ static int icuLikeCompare(
     }else{
       /* Case 4. */
       UChar32 uString;
-      U8_NEXT_UNSAFE(zString, iString, uString);
+      SQLITE_ICU_READ_UTF8(zString, uString);
       uString = u_foldCase(uString, U_FOLD_CASE_DEFAULT);
       uPattern = u_foldCase(uPattern, U_FOLD_CASE_DEFAULT);
       if( uString!=uPattern ){
@@ -131256,7 +163699,7 @@ static int icuLikeCompare(
     }
   }
 
-  return zString[iString]==0;
+  return *zString==0;
 }
 
 /*
@@ -131441,15 +163884,17 @@ static void icuRegexpFunc(sqlite3_context *p, int nArg, sqlite3_value **apArg){
 ** http://www.icu-project.org/userguide/posix.html#case_mappings
 */
 static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
-  const UChar *zInput;
-  UChar *zOutput;
-  int nInput;
-  int nOutput;
-
-  UErrorCode status = U_ZERO_ERROR;
+  const UChar *zInput;            /* Pointer to input string */
+  UChar *zOutput = 0;             /* Pointer to output buffer */
+  int nInput;                     /* Size of utf-16 input string in bytes */
+  int nOut;                       /* Size of output buffer in bytes */
+  int cnt;
+  int bToUpper;                   /* True for toupper(), false for tolower() */
+  UErrorCode status;
   const char *zLocale = 0;
 
   assert(nArg==1 || nArg==2);
+  bToUpper = (sqlite3_user_data(p)!=0);
   if( nArg==2 ){
     zLocale = (const char *)sqlite3_value_text(apArg[1]);
   }
@@ -131458,26 +163903,38 @@ static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
   if( !zInput ){
     return;
   }
-  nInput = sqlite3_value_bytes16(apArg[0]);
-
-  nOutput = nInput * 2 + 2;
-  zOutput = sqlite3_malloc(nOutput);
-  if( !zOutput ){
+  nOut = nInput = sqlite3_value_bytes16(apArg[0]);
+  if( nOut==0 ){
+    sqlite3_result_text16(p, "", 0, SQLITE_STATIC);
     return;
   }
 
-  if( sqlite3_user_data(p) ){
-    u_strToUpper(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
-  }else{
-    u_strToLower(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
-  }
+  for(cnt=0; cnt<2; cnt++){
+    UChar *zNew = sqlite3_realloc(zOutput, nOut);
+    if( zNew==0 ){
+      sqlite3_free(zOutput);
+      sqlite3_result_error_nomem(p);
+      return;
+    }
+    zOutput = zNew;
+    status = U_ZERO_ERROR;
+    if( bToUpper ){
+      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }else{
+      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
+    }
 
-  if( !U_SUCCESS(status) ){
-    icuFunctionError(p, "u_strToLower()/u_strToUpper", status);
+    if( U_SUCCESS(status) ){
+      sqlite3_result_text16(p, zOutput, nOut, xFree);
+    }else if( status==U_BUFFER_OVERFLOW_ERROR ){
+      assert( cnt==0 );
+      continue;
+    }else{
+      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
+    }
     return;
   }
-
-  sqlite3_result_text16(p, zOutput, -1, xFree);
+  assert( 0 );     /* Unreachable */
 }
 
 /*
@@ -131538,6 +163995,7 @@ static void icuLoadCollation(
   int rc;                   /* Return code from sqlite3_create_collation_x() */
 
   assert(nArg==2);
+  (void)nArg; /* Unused parameter */
   zLocale = (const char *)sqlite3_value_text(apArg[0]);
   zName = (const char *)sqlite3_value_text(apArg[1]);
 
@@ -131604,7 +164062,10 @@ SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-SQLITE_API int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_icu_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
@@ -131631,11 +164092,13 @@ SQLITE_API int sqlite3_extension_init(
 *************************************************************************
 ** This file implements a tokenizer for fts3 based on the ICU library.
 */
+/* #include "fts3Int.h" */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
 #ifdef SQLITE_ENABLE_ICU
 
 /* #include <assert.h> */
 /* #include <string.h> */
+/* #include "fts3_tokenizer.h" */
 
 #include <unicode/ubrk.h>
 /* #include <unicode/ucol.h> */
@@ -131728,13 +164191,16 @@ static int icuOpen(
 
   *ppCursor = 0;
 
-  if( nInput<0 ){
+  if( zInput==0 ){
+    nInput = 0;
+    zInput = "";
+  }else if( nInput<0 ){
     nInput = strlen(zInput);
   }
   nChar = nInput+1;
   pCsr = (IcuCursor *)sqlite3_malloc(
       sizeof(IcuCursor) +                /* IcuCursor */
-      nChar * sizeof(UChar) +            /* IcuCursor.aChar[] */
+      ((nChar+3)&~3) * sizeof(UChar) +   /* IcuCursor.aChar[] */
       (nChar+1) * sizeof(int)            /* IcuCursor.aOffset[] */
   );
   if( !pCsr ){
@@ -131742,7 +164208,7 @@ static int icuOpen(
   }
   memset(pCsr, 0, sizeof(IcuCursor));
   pCsr->aChar = (UChar *)&pCsr[1];
-  pCsr->aOffset = (int *)&pCsr->aChar[nChar];
+  pCsr->aOffset = (int *)&pCsr->aChar[(nChar+3)&~3];
 
   pCsr->aOffset[iOut] = iInput;
   U8_NEXT(zInput, iInput, nInput, c); 
@@ -131814,7 +164280,7 @@ static int icuNext(
 
     while( iStart<iEnd ){
       int iWhite = iStart;
-      U8_NEXT(pCsr->aChar, iWhite, pCsr->nChar, c);
+      U16_NEXT(pCsr->aChar, iWhite, pCsr->nChar, c);
       if( u_isspace(c) ){
         iStart = iWhite;
       }else{
@@ -131855,12 +164321,13 @@ static int icuNext(
 ** The set of routines that implement the simple tokenizer
 */
 static const sqlite3_tokenizer_module icuTokenizerModule = {
-  0,                           /* iVersion */
-  icuCreate,                   /* xCreate  */
-  icuDestroy,                  /* xCreate  */
-  icuOpen,                     /* xOpen    */
-  icuClose,                    /* xClose   */
-  icuNext,                     /* xNext    */
+  0,                           /* iVersion    */
+  icuCreate,                   /* xCreate     */
+  icuDestroy,                  /* xCreate     */
+  icuOpen,                     /* xOpen       */
+  icuClose,                    /* xClose      */
+  icuNext,                     /* xNext       */
+  0,                           /* xLanguageid */
 };
 
 /*
@@ -131876,3 +164343,33528 @@ SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
 
 /************** End of fts3_icu.c ********************************************/
+/************** Begin file sqlite3rbu.c **************************************/
+/*
+** 2014 August 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+**
+** OVERVIEW 
+**
+**  The RBU extension requires that the RBU update be packaged as an
+**  SQLite database. The tables it expects to find are described in
+**  sqlite3rbu.h.  Essentially, for each table xyz in the target database
+**  that the user wishes to write to, a corresponding data_xyz table is
+**  created in the RBU database and populated with one row for each row to
+**  update, insert or delete from the target table.
+** 
+**  The update proceeds in three stages:
+** 
+**  1) The database is updated. The modified database pages are written
+**     to a *-oal file. A *-oal file is just like a *-wal file, except
+**     that it is named "<database>-oal" instead of "<database>-wal".
+**     Because regular SQLite clients do not look for file named
+**     "<database>-oal", they go on using the original database in
+**     rollback mode while the *-oal file is being generated.
+** 
+**     During this stage RBU does not update the database by writing
+**     directly to the target tables. Instead it creates "imposter"
+**     tables using the SQLITE_TESTCTRL_IMPOSTER interface that it uses
+**     to update each b-tree individually. All updates required by each
+**     b-tree are completed before moving on to the next, and all
+**     updates are done in sorted key order.
+** 
+**  2) The "<database>-oal" file is moved to the equivalent "<database>-wal"
+**     location using a call to rename(2). Before doing this the RBU
+**     module takes an EXCLUSIVE lock on the database file, ensuring
+**     that there are no other active readers.
+** 
+**     Once the EXCLUSIVE lock is released, any other database readers
+**     detect the new *-wal file and read the database in wal mode. At
+**     this point they see the new version of the database - including
+**     the updates made as part of the RBU update.
+** 
+**  3) The new *-wal file is checkpointed. This proceeds in the same way 
+**     as a regular database checkpoint, except that a single frame is
+**     checkpointed each time sqlite3rbu_step() is called. If the RBU
+**     handle is closed before the entire *-wal file is checkpointed,
+**     the checkpoint progress is saved in the RBU database and the
+**     checkpoint can be resumed by another RBU client at some point in
+**     the future.
+**
+** POTENTIAL PROBLEMS
+** 
+**  The rename() call might not be portable. And RBU is not currently
+**  syncing the directory after renaming the file.
+**
+**  When state is saved, any commit to the *-oal file and the commit to
+**  the RBU update database are not atomic. So if the power fails at the
+**  wrong moment they might get out of sync. As the main database will be
+**  committed before the RBU update database this will likely either just
+**  pass unnoticed, or result in SQLITE_CONSTRAINT errors (due to UNIQUE
+**  constraint violations).
+**
+**  If some client does modify the target database mid RBU update, or some
+**  other error occurs, the RBU extension will keep throwing errors. It's
+**  not really clear how to get out of this state. The system could just
+**  by delete the RBU update database and *-oal file and have the device
+**  download the update again and start over.
+**
+**  At present, for an UPDATE, both the new.* and old.* records are
+**  collected in the rbu_xyz table. And for both UPDATEs and DELETEs all
+**  fields are collected.  This means we're probably writing a lot more
+**  data to disk when saving the state of an ongoing update to the RBU
+**  update database than is strictly necessary.
+** 
+*/
+
+/* #include <assert.h> */
+/* #include <string.h> */
+/* #include <stdio.h> */
+
+/* #include "sqlite3.h" */
+
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU)
+/************** Include sqlite3rbu.h in the middle of sqlite3rbu.c ***********/
+/************** Begin file sqlite3rbu.h **************************************/
+/*
+** 2014 August 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the public interface for the RBU extension. 
+*/
+
+/*
+** SUMMARY
+**
+** Writing a transaction containing a large number of operations on 
+** b-tree indexes that are collectively larger than the available cache
+** memory can be very inefficient. 
+**
+** The problem is that in order to update a b-tree, the leaf page (at least)
+** containing the entry being inserted or deleted must be modified. If the
+** working set of leaves is larger than the available cache memory, then a 
+** single leaf that is modified more than once as part of the transaction 
+** may be loaded from or written to the persistent media multiple times.
+** Additionally, because the index updates are likely to be applied in
+** random order, access to pages within the database is also likely to be in 
+** random order, which is itself quite inefficient.
+**
+** One way to improve the situation is to sort the operations on each index
+** by index key before applying them to the b-tree. This leads to an IO
+** pattern that resembles a single linear scan through the index b-tree,
+** and all but guarantees each modified leaf page is loaded and stored 
+** exactly once. SQLite uses this trick to improve the performance of
+** CREATE INDEX commands. This extension allows it to be used to improve
+** the performance of large transactions on existing databases.
+**
+** Additionally, this extension allows the work involved in writing the 
+** large transaction to be broken down into sub-transactions performed 
+** sequentially by separate processes. This is useful if the system cannot 
+** guarantee that a single update process will run for long enough to apply 
+** the entire update, for example because the update is being applied on a 
+** mobile device that is frequently rebooted. Even after the writer process 
+** has committed one or more sub-transactions, other database clients continue
+** to read from the original database snapshot. In other words, partially 
+** applied transactions are not visible to other clients. 
+**
+** "RBU" stands for "Resumable Bulk Update". As in a large database update
+** transmitted via a wireless network to a mobile device. A transaction
+** applied using this extension is hence refered to as an "RBU update".
+**
+**
+** LIMITATIONS
+**
+** An "RBU update" transaction is subject to the following limitations:
+**
+**   * The transaction must consist of INSERT, UPDATE and DELETE operations
+**     only.
+**
+**   * INSERT statements may not use any default values.
+**
+**   * UPDATE and DELETE statements must identify their target rows by 
+**     non-NULL PRIMARY KEY values. Rows with NULL values stored in PRIMARY
+**     KEY fields may not be updated or deleted. If the table being written 
+**     has no PRIMARY KEY, affected rows must be identified by rowid.
+**
+**   * UPDATE statements may not modify PRIMARY KEY columns.
+**
+**   * No triggers will be fired.
+**
+**   * No foreign key violations are detected or reported.
+**
+**   * CHECK constraints are not enforced.
+**
+**   * No constraint handling mode except for "OR ROLLBACK" is supported.
+**
+**
+** PREPARATION
+**
+** An "RBU update" is stored as a separate SQLite database. A database
+** containing an RBU update is an "RBU database". For each table in the 
+** target database to be updated, the RBU database should contain a table
+** named "data_<target name>" containing the same set of columns as the
+** target table, and one more - "rbu_control". The data_% table should 
+** have no PRIMARY KEY or UNIQUE constraints, but each column should have
+** the same type as the corresponding column in the target database.
+** The "rbu_control" column should have no type at all. For example, if
+** the target database contains:
+**
+**   CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT, c UNIQUE);
+**
+** Then the RBU database should contain:
+**
+**   CREATE TABLE data_t1(a INTEGER, b TEXT, c, rbu_control);
+**
+** The order of the columns in the data_% table does not matter.
+**
+** Instead of a regular table, the RBU database may also contain virtual
+** tables or view named using the data_<target> naming scheme. 
+**
+** Instead of the plain data_<target> naming scheme, RBU database tables 
+** may also be named data<integer>_<target>, where <integer> is any sequence
+** of zero or more numeric characters (0-9). This can be significant because
+** tables within the RBU database are always processed in order sorted by 
+** name. By judicious selection of the the <integer> portion of the names
+** of the RBU tables the user can therefore control the order in which they
+** are processed. This can be useful, for example, to ensure that "external
+** content" FTS4 tables are updated before their underlying content tables.
+**
+** If the target database table is a virtual table or a table that has no
+** PRIMARY KEY declaration, the data_% table must also contain a column 
+** named "rbu_rowid". This column is mapped to the tables implicit primary 
+** key column - "rowid". Virtual tables for which the "rowid" column does 
+** not function like a primary key value cannot be updated using RBU. For 
+** example, if the target db contains either of the following:
+**
+**   CREATE VIRTUAL TABLE x1 USING fts3(a, b);
+**   CREATE TABLE x1(a, b)
+**
+** then the RBU database should contain:
+**
+**   CREATE TABLE data_x1(a, b, rbu_rowid, rbu_control);
+**
+** All non-hidden columns (i.e. all columns matched by "SELECT *") of the
+** target table must be present in the input table. For virtual tables,
+** hidden columns are optional - they are updated by RBU if present in
+** the input table, or not otherwise. For example, to write to an fts4
+** table with a hidden languageid column such as:
+**
+**   CREATE VIRTUAL TABLE ft1 USING fts4(a, b, languageid='langid');
+**
+** Either of the following input table schemas may be used:
+**
+**   CREATE TABLE data_ft1(a, b, langid, rbu_rowid, rbu_control);
+**   CREATE TABLE data_ft1(a, b, rbu_rowid, rbu_control);
+**
+** For each row to INSERT into the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain integer value 0. The
+** other columns should be set to the values that make up the new record 
+** to insert. 
+**
+** If the target database table has an INTEGER PRIMARY KEY, it is not 
+** possible to insert a NULL value into the IPK column. Attempting to 
+** do so results in an SQLITE_MISMATCH error.
+**
+** For each row to DELETE from the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain integer value 1. The
+** real primary key values of the row to delete should be stored in the
+** corresponding columns of the data_% table. The values stored in the
+** other columns are not used.
+**
+** For each row to UPDATE from the target database as part of the RBU 
+** update, the corresponding data_% table should contain a single record
+** with the "rbu_control" column set to contain a value of type text.
+** The real primary key values identifying the row to update should be 
+** stored in the corresponding columns of the data_% table row, as should
+** the new values of all columns being update. The text value in the 
+** "rbu_control" column must contain the same number of characters as
+** there are columns in the target database table, and must consist entirely
+** of 'x' and '.' characters (or in some special cases 'd' - see below). For 
+** each column that is being updated, the corresponding character is set to
+** 'x'. For those that remain as they are, the corresponding character of the
+** rbu_control value should be set to '.'. For example, given the tables 
+** above, the update statement:
+**
+**   UPDATE t1 SET c = 'usa' WHERE a = 4;
+**
+** is represented by the data_t1 row created by:
+**
+**   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..x');
+**
+** Instead of an 'x' character, characters of the rbu_control value specified
+** for UPDATEs may also be set to 'd'. In this case, instead of updating the
+** target table with the value stored in the corresponding data_% column, the
+** user-defined SQL function "rbu_delta()" is invoked and the result stored in
+** the target table column. rbu_delta() is invoked with two arguments - the
+** original value currently stored in the target table column and the 
+** value specified in the data_xxx table.
+**
+** For example, this row:
+**
+**   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..d');
+**
+** is similar to an UPDATE statement such as: 
+**
+**   UPDATE t1 SET c = rbu_delta(c, 'usa') WHERE a = 4;
+**
+** Finally, if an 'f' character appears in place of a 'd' or 's' in an 
+** ota_control string, the contents of the data_xxx table column is assumed
+** to be a "fossil delta" - a patch to be applied to a blob value in the
+** format used by the fossil source-code management system. In this case
+** the existing value within the target database table must be of type BLOB. 
+** It is replaced by the result of applying the specified fossil delta to
+** itself.
+**
+** If the target database table is a virtual table or a table with no PRIMARY
+** KEY, the rbu_control value should not include a character corresponding 
+** to the rbu_rowid value. For example, this:
+**
+**   INSERT INTO data_ft1(a, b, rbu_rowid, rbu_control) 
+**       VALUES(NULL, 'usa', 12, '.x');
+**
+** causes a result similar to:
+**
+**   UPDATE ft1 SET b = 'usa' WHERE rowid = 12;
+**
+** The data_xxx tables themselves should have no PRIMARY KEY declarations.
+** However, RBU is more efficient if reading the rows in from each data_xxx
+** table in "rowid" order is roughly the same as reading them sorted by
+** the PRIMARY KEY of the corresponding target database table. In other 
+** words, rows should be sorted using the destination table PRIMARY KEY 
+** fields before they are inserted into the data_xxx tables.
+**
+** USAGE
+**
+** The API declared below allows an application to apply an RBU update 
+** stored on disk to an existing target database. Essentially, the 
+** application:
+**
+**     1) Opens an RBU handle using the sqlite3rbu_open() function.
+**
+**     2) Registers any required virtual table modules with the database
+**        handle returned by sqlite3rbu_db(). Also, if required, register
+**        the rbu_delta() implementation.
+**
+**     3) Calls the sqlite3rbu_step() function one or more times on
+**        the new handle. Each call to sqlite3rbu_step() performs a single
+**        b-tree operation, so thousands of calls may be required to apply 
+**        a complete update.
+**
+**     4) Calls sqlite3rbu_close() to close the RBU update handle. If
+**        sqlite3rbu_step() has been called enough times to completely
+**        apply the update to the target database, then the RBU database
+**        is marked as fully applied. Otherwise, the state of the RBU 
+**        update application is saved in the RBU database for later 
+**        resumption.
+**
+** See comments below for more detail on APIs.
+**
+** If an update is only partially applied to the target database by the
+** time sqlite3rbu_close() is called, various state information is saved 
+** within the RBU database. This allows subsequent processes to automatically
+** resume the RBU update from where it left off.
+**
+** To remove all RBU extension state information, returning an RBU database 
+** to its original contents, it is sufficient to drop all tables that begin
+** with the prefix "rbu_"
+**
+** DATABASE LOCKING
+**
+** An RBU update may not be applied to a database in WAL mode. Attempting
+** to do so is an error (SQLITE_ERROR).
+**
+** While an RBU handle is open, a SHARED lock may be held on the target
+** database file. This means it is possible for other clients to read the
+** database, but not to write it.
+**
+** If an RBU update is started and then suspended before it is completed,
+** then an external client writes to the database, then attempting to resume
+** the suspended RBU update is also an error (SQLITE_BUSY).
+*/
+
+#ifndef _SQLITE3RBU_H
+#define _SQLITE3RBU_H
+
+/* #include "sqlite3.h"              ** Required for error code definitions ** */
+
+#if 0
+extern "C" {
+#endif
+
+typedef struct sqlite3rbu sqlite3rbu;
+
+/*
+** Open an RBU handle.
+**
+** Argument zTarget is the path to the target database. Argument zRbu is
+** the path to the RBU database. Each call to this function must be matched
+** by a call to sqlite3rbu_close(). When opening the databases, RBU passes
+** the SQLITE_CONFIG_URI flag to sqlite3_open_v2(). So if either zTarget
+** or zRbu begin with "file:", it will be interpreted as an SQLite 
+** database URI, not a regular file name.
+**
+** If the zState argument is passed a NULL value, the RBU extension stores 
+** the current state of the update (how many rows have been updated, which 
+** indexes are yet to be updated etc.) within the RBU database itself. This
+** can be convenient, as it means that the RBU application does not need to
+** organize removing a separate state file after the update is concluded. 
+** Or, if zState is non-NULL, it must be a path to a database file in which 
+** the RBU extension can store the state of the update.
+**
+** When resuming an RBU update, the zState argument must be passed the same
+** value as when the RBU update was started.
+**
+** Once the RBU update is finished, the RBU extension does not 
+** automatically remove any zState database file, even if it created it.
+**
+** By default, RBU uses the default VFS to access the files on disk. To
+** use a VFS other than the default, an SQLite "file:" URI containing a
+** "vfs=..." option may be passed as the zTarget option.
+**
+** IMPORTANT NOTE FOR ZIPVFS USERS: The RBU extension works with all of
+** SQLite's built-in VFSs, including the multiplexor VFS. However it does
+** not work out of the box with zipvfs. Refer to the comment describing
+** the zipvfs_create_vfs() API below for details on using RBU with zipvfs.
+*/
+SQLITE_API sqlite3rbu *SQLITE_STDCALL sqlite3rbu_open(
+  const char *zTarget, 
+  const char *zRbu,
+  const char *zState
+);
+
+/*
+** Open an RBU handle to perform an RBU vacuum on database file zTarget.
+** An RBU vacuum is similar to SQLite's built-in VACUUM command, except
+** that it can be suspended and resumed like an RBU update.
+**
+** The second argument to this function, which may not be NULL, identifies 
+** a database in which to store the state of the RBU vacuum operation if
+** it is suspended. The first time sqlite3rbu_vacuum() is called, to start
+** an RBU vacuum operation, the state database should either not exist or
+** be empty (contain no tables). If an RBU vacuum is suspended by calling
+** sqlite3rbu_close() on the RBU handle before sqlite3rbu_step() has
+** returned SQLITE_DONE, the vacuum state is stored in the state database. 
+** The vacuum can be resumed by calling this function to open a new RBU
+** handle specifying the same target and state databases.
+**
+** This function does not delete the state database after an RBU vacuum
+** is completed, even if it created it. However, if the call to
+** sqlite3rbu_close() returns any value other than SQLITE_OK, the contents
+** of the state tables within the state database are zeroed. This way,
+** the next call to sqlite3rbu_vacuum() opens a handle that starts a 
+** new RBU vacuum operation.
+**
+** As with sqlite3rbu_open(), Zipvfs users should rever to the comment
+** describing the sqlite3rbu_create_vfs() API function below for 
+** a description of the complications associated with using RBU with 
+** zipvfs databases.
+*/
+SQLITE_API sqlite3rbu *SQLITE_STDCALL sqlite3rbu_vacuum(
+  const char *zTarget, 
+  const char *zState
+);
+
+/*
+** Internally, each RBU connection uses a separate SQLite database 
+** connection to access the target and rbu update databases. This
+** API allows the application direct access to these database handles.
+**
+** The first argument passed to this function must be a valid, open, RBU
+** handle. The second argument should be passed zero to access the target
+** database handle, or non-zero to access the rbu update database handle.
+** Accessing the underlying database handles may be useful in the
+** following scenarios:
+**
+**   * If any target tables are virtual tables, it may be necessary to
+**     call sqlite3_create_module() on the target database handle to 
+**     register the required virtual table implementations.
+**
+**   * If the data_xxx tables in the RBU source database are virtual 
+**     tables, the application may need to call sqlite3_create_module() on
+**     the rbu update db handle to any required virtual table
+**     implementations.
+**
+**   * If the application uses the "rbu_delta()" feature described above,
+**     it must use sqlite3_create_function() or similar to register the
+**     rbu_delta() implementation with the target database handle.
+**
+** If an error has occurred, either while opening or stepping the RBU object,
+** this function may return NULL. The error code and message may be collected
+** when sqlite3rbu_close() is called.
+**
+** Database handles returned by this function remain valid until the next
+** call to any sqlite3rbu_xxx() function other than sqlite3rbu_db().
+*/
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3rbu_db(sqlite3rbu*, int bRbu);
+
+/*
+** Do some work towards applying the RBU update to the target db. 
+**
+** Return SQLITE_DONE if the update has been completely applied, or 
+** SQLITE_OK if no error occurs but there remains work to do to apply
+** the RBU update. If an error does occur, some other error code is 
+** returned. 
+**
+** Once a call to sqlite3rbu_step() has returned a value other than
+** SQLITE_OK, all subsequent calls on the same RBU handle are no-ops
+** that immediately return the same value.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_step(sqlite3rbu *pRbu);
+
+/*
+** Force RBU to save its state to disk.
+**
+** If a power failure or application crash occurs during an update, following
+** system recovery RBU may resume the update from the point at which the state
+** was last saved. In other words, from the most recent successful call to 
+** sqlite3rbu_close() or this function.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_savestate(sqlite3rbu *pRbu);
+
+/*
+** Close an RBU handle. 
+**
+** If the RBU update has been completely applied, mark the RBU database
+** as fully applied. Otherwise, assuming no error has occurred, save the
+** current state of the RBU update appliation to the RBU database.
+**
+** If an error has already occurred as part of an sqlite3rbu_step()
+** or sqlite3rbu_open() call, or if one occurs within this function, an
+** SQLite error code is returned. Additionally, *pzErrmsg may be set to
+** point to a buffer containing a utf-8 formatted English language error
+** message. It is the responsibility of the caller to eventually free any 
+** such buffer using sqlite3_free().
+**
+** Otherwise, if no error occurs, this function returns SQLITE_OK if the
+** update has been partially applied, or SQLITE_DONE if it has been 
+** completely applied.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_close(sqlite3rbu *pRbu, char **pzErrmsg);
+
+/*
+** Return the total number of key-value operations (inserts, deletes or 
+** updates) that have been performed on the target database since the
+** current RBU update was started.
+*/
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3rbu_progress(sqlite3rbu *pRbu);
+
+/*
+** Obtain permyriadage (permyriadage is to 10000 as percentage is to 100) 
+** progress indications for the two stages of an RBU update. This API may
+** be useful for driving GUI progress indicators and similar.
+**
+** An RBU update is divided into two stages:
+**
+**   * Stage 1, in which changes are accumulated in an oal/wal file, and
+**   * Stage 2, in which the contents of the wal file are copied into the
+**     main database.
+**
+** The update is visible to non-RBU clients during stage 2. During stage 1
+** non-RBU reader clients may see the original database.
+**
+** If this API is called during stage 2 of the update, output variable 
+** (*pnOne) is set to 10000 to indicate that stage 1 has finished and (*pnTwo)
+** to a value between 0 and 10000 to indicate the permyriadage progress of
+** stage 2. A value of 5000 indicates that stage 2 is half finished, 
+** 9000 indicates that it is 90% finished, and so on.
+**
+** If this API is called during stage 1 of the update, output variable 
+** (*pnTwo) is set to 0 to indicate that stage 2 has not yet started. The
+** value to which (*pnOne) is set depends on whether or not the RBU 
+** database contains an "rbu_count" table. The rbu_count table, if it 
+** exists, must contain the same columns as the following:
+**
+**   CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID;
+**
+** There must be one row in the table for each source (data_xxx) table within
+** the RBU database. The 'tbl' column should contain the name of the source
+** table. The 'cnt' column should contain the number of rows within the
+** source table.
+**
+** If the rbu_count table is present and populated correctly and this
+** API is called during stage 1, the *pnOne output variable is set to the
+** permyriadage progress of the same stage. If the rbu_count table does
+** not exist, then (*pnOne) is set to -1 during stage 1. If the rbu_count
+** table exists but is not correctly populated, the value of the *pnOne
+** output variable during stage 1 is undefined.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3rbu_bp_progress(sqlite3rbu *pRbu, int *pnOne, int *pnTwo);
+
+/*
+** Obtain an indication as to the current stage of an RBU update or vacuum.
+** This function always returns one of the SQLITE_RBU_STATE_XXX constants
+** defined in this file. Return values should be interpreted as follows:
+**
+** SQLITE_RBU_STATE_OAL:
+**   RBU is currently building a *-oal file. The next call to sqlite3rbu_step()
+**   may either add further data to the *-oal file, or compute data that will
+**   be added by a subsequent call.
+**
+** SQLITE_RBU_STATE_MOVE:
+**   RBU has finished building the *-oal file. The next call to sqlite3rbu_step()
+**   will move the *-oal file to the equivalent *-wal path. If the current
+**   operation is an RBU update, then the updated version of the database
+**   file will become visible to ordinary SQLite clients following the next
+**   call to sqlite3rbu_step().
+**
+** SQLITE_RBU_STATE_CHECKPOINT:
+**   RBU is currently performing an incremental checkpoint. The next call to
+**   sqlite3rbu_step() will copy a page of data from the *-wal file into
+**   the target database file.
+**
+** SQLITE_RBU_STATE_DONE:
+**   The RBU operation has finished. Any subsequent calls to sqlite3rbu_step()
+**   will immediately return SQLITE_DONE.
+**
+** SQLITE_RBU_STATE_ERROR:
+**   An error has occurred. Any subsequent calls to sqlite3rbu_step() will
+**   immediately return the SQLite error code associated with the error.
+*/
+#define SQLITE_RBU_STATE_OAL        1
+#define SQLITE_RBU_STATE_MOVE       2
+#define SQLITE_RBU_STATE_CHECKPOINT 3
+#define SQLITE_RBU_STATE_DONE       4
+#define SQLITE_RBU_STATE_ERROR      5
+
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_state(sqlite3rbu *pRbu);
+
+/*
+** Create an RBU VFS named zName that accesses the underlying file-system
+** via existing VFS zParent. Or, if the zParent parameter is passed NULL, 
+** then the new RBU VFS uses the default system VFS to access the file-system.
+** The new object is registered as a non-default VFS with SQLite before 
+** returning.
+**
+** Part of the RBU implementation uses a custom VFS object. Usually, this
+** object is created and deleted automatically by RBU. 
+**
+** The exception is for applications that also use zipvfs. In this case,
+** the custom VFS must be explicitly created by the user before the RBU
+** handle is opened. The RBU VFS should be installed so that the zipvfs
+** VFS uses the RBU VFS, which in turn uses any other VFS layers in use 
+** (for example multiplexor) to access the file-system. For example,
+** to assemble an RBU enabled VFS stack that uses both zipvfs and 
+** multiplexor (error checking omitted):
+**
+**     // Create a VFS named "multiplex" (not the default).
+**     sqlite3_multiplex_initialize(0, 0);
+**
+**     // Create an rbu VFS named "rbu" that uses multiplexor. If the
+**     // second argument were replaced with NULL, the "rbu" VFS would
+**     // access the file-system via the system default VFS, bypassing the
+**     // multiplexor.
+**     sqlite3rbu_create_vfs("rbu", "multiplex");
+**
+**     // Create a zipvfs VFS named "zipvfs" that uses rbu.
+**     zipvfs_create_vfs_v3("zipvfs", "rbu", 0, xCompressorAlgorithmDetector);
+**
+**     // Make zipvfs the default VFS.
+**     sqlite3_vfs_register(sqlite3_vfs_find("zipvfs"), 1);
+**
+** Because the default VFS created above includes a RBU functionality, it
+** may be used by RBU clients. Attempting to use RBU with a zipvfs VFS stack
+** that does not include the RBU layer results in an error.
+**
+** The overhead of adding the "rbu" VFS to the system is negligible for 
+** non-RBU users. There is no harm in an application accessing the 
+** file-system via "rbu" all the time, even if it only uses RBU functionality 
+** occasionally.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_create_vfs(const char *zName, const char *zParent);
+
+/*
+** Deregister and destroy an RBU vfs created by an earlier call to
+** sqlite3rbu_create_vfs().
+**
+** VFS objects are not reference counted. If a VFS object is destroyed
+** before all database handles that use it have been closed, the results
+** are undefined.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3rbu_destroy_vfs(const char *zName);
+
+#if 0
+}  /* end of the 'extern "C"' block */
+#endif
+
+#endif /* _SQLITE3RBU_H */
+
+/************** End of sqlite3rbu.h ******************************************/
+/************** Continuing where we left off in sqlite3rbu.c *****************/
+
+#if defined(_WIN32_WCE)
+/* #include "windows.h" */
+#endif
+
+/* Maximum number of prepared UPDATE statements held by this module */
+#define SQLITE_RBU_UPDATE_CACHESIZE 16
+
+/*
+** Swap two objects of type TYPE.
+*/
+#if !defined(SQLITE_AMALGAMATION)
+# define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
+#endif
+
+/*
+** The rbu_state table is used to save the state of a partially applied
+** update so that it can be resumed later. The table consists of integer
+** keys mapped to values as follows:
+**
+** RBU_STATE_STAGE:
+**   May be set to integer values 1, 2, 4 or 5. As follows:
+**       1: the *-rbu file is currently under construction.
+**       2: the *-rbu file has been constructed, but not yet moved 
+**          to the *-wal path.
+**       4: the checkpoint is underway.
+**       5: the rbu update has been checkpointed.
+**
+** RBU_STATE_TBL:
+**   Only valid if STAGE==1. The target database name of the table 
+**   currently being written.
+**
+** RBU_STATE_IDX:
+**   Only valid if STAGE==1. The target database name of the index 
+**   currently being written, or NULL if the main table is currently being
+**   updated.
+**
+** RBU_STATE_ROW:
+**   Only valid if STAGE==1. Number of rows already processed for the current
+**   table/index.
+**
+** RBU_STATE_PROGRESS:
+**   Trbul number of sqlite3rbu_step() calls made so far as part of this
+**   rbu update.
+**
+** RBU_STATE_CKPT:
+**   Valid if STAGE==4. The 64-bit checksum associated with the wal-index
+**   header created by recovering the *-wal file. This is used to detect
+**   cases when another client appends frames to the *-wal file in the
+**   middle of an incremental checkpoint (an incremental checkpoint cannot
+**   be continued if this happens).
+**
+** RBU_STATE_COOKIE:
+**   Valid if STAGE==1. The current change-counter cookie value in the 
+**   target db file.
+**
+** RBU_STATE_OALSZ:
+**   Valid if STAGE==1. The size in bytes of the *-oal file.
+*/
+#define RBU_STATE_STAGE        1
+#define RBU_STATE_TBL          2
+#define RBU_STATE_IDX          3
+#define RBU_STATE_ROW          4
+#define RBU_STATE_PROGRESS     5
+#define RBU_STATE_CKPT         6
+#define RBU_STATE_COOKIE       7
+#define RBU_STATE_OALSZ        8
+#define RBU_STATE_PHASEONESTEP 9
+
+#define RBU_STAGE_OAL         1
+#define RBU_STAGE_MOVE        2
+#define RBU_STAGE_CAPTURE     3
+#define RBU_STAGE_CKPT        4
+#define RBU_STAGE_DONE        5
+
+
+#define RBU_CREATE_STATE \
+  "CREATE TABLE IF NOT EXISTS %s.rbu_state(k INTEGER PRIMARY KEY, v)"
+
+typedef struct RbuFrame RbuFrame;
+typedef struct RbuObjIter RbuObjIter;
+typedef struct RbuState RbuState;
+typedef struct rbu_vfs rbu_vfs;
+typedef struct rbu_file rbu_file;
+typedef struct RbuUpdateStmt RbuUpdateStmt;
+
+#if !defined(SQLITE_AMALGAMATION)
+typedef unsigned int u32;
+typedef unsigned short u16;
+typedef unsigned char u8;
+typedef sqlite3_int64 i64;
+#endif
+
+/*
+** These values must match the values defined in wal.c for the equivalent
+** locks. These are not magic numbers as they are part of the SQLite file
+** format.
+*/
+#define WAL_LOCK_WRITE  0
+#define WAL_LOCK_CKPT   1
+#define WAL_LOCK_READ0  3
+
+#define SQLITE_FCNTL_RBUCNT    5149216
+
+/*
+** A structure to store values read from the rbu_state table in memory.
+*/
+struct RbuState {
+  int eStage;
+  char *zTbl;
+  char *zIdx;
+  i64 iWalCksum;
+  int nRow;
+  i64 nProgress;
+  u32 iCookie;
+  i64 iOalSz;
+  i64 nPhaseOneStep;
+};
+
+struct RbuUpdateStmt {
+  char *zMask;                    /* Copy of update mask used with pUpdate */
+  sqlite3_stmt *pUpdate;          /* Last update statement (or NULL) */
+  RbuUpdateStmt *pNext;
+};
+
+/*
+** An iterator of this type is used to iterate through all objects in
+** the target database that require updating. For each such table, the
+** iterator visits, in order:
+**
+**     * the table itself, 
+**     * each index of the table (zero or more points to visit), and
+**     * a special "cleanup table" state.
+**
+** abIndexed:
+**   If the table has no indexes on it, abIndexed is set to NULL. Otherwise,
+**   it points to an array of flags nTblCol elements in size. The flag is
+**   set for each column that is either a part of the PK or a part of an
+**   index. Or clear otherwise.
+**   
+*/
+struct RbuObjIter {
+  sqlite3_stmt *pTblIter;         /* Iterate through tables */
+  sqlite3_stmt *pIdxIter;         /* Index iterator */
+  int nTblCol;                    /* Size of azTblCol[] array */
+  char **azTblCol;                /* Array of unquoted target column names */
+  char **azTblType;               /* Array of target column types */
+  int *aiSrcOrder;                /* src table col -> target table col */
+  u8 *abTblPk;                    /* Array of flags, set on target PK columns */
+  u8 *abNotNull;                  /* Array of flags, set on NOT NULL columns */
+  u8 *abIndexed;                  /* Array of flags, set on indexed & PK cols */
+  int eType;                      /* Table type - an RBU_PK_XXX value */
+
+  /* Output variables. zTbl==0 implies EOF. */
+  int bCleanup;                   /* True in "cleanup" state */
+  const char *zTbl;               /* Name of target db table */
+  const char *zDataTbl;           /* Name of rbu db table (or null) */
+  const char *zIdx;               /* Name of target db index (or null) */
+  int iTnum;                      /* Root page of current object */
+  int iPkTnum;                    /* If eType==EXTERNAL, root of PK index */
+  int bUnique;                    /* Current index is unique */
+  int nIndex;                     /* Number of aux. indexes on table zTbl */
+
+  /* Statements created by rbuObjIterPrepareAll() */
+  int nCol;                       /* Number of columns in current object */
+  sqlite3_stmt *pSelect;          /* Source data */
+  sqlite3_stmt *pInsert;          /* Statement for INSERT operations */
+  sqlite3_stmt *pDelete;          /* Statement for DELETE ops */
+  sqlite3_stmt *pTmpInsert;       /* Insert into rbu_tmp_$zDataTbl */
+
+  /* Last UPDATE used (for PK b-tree updates only), or NULL. */
+  RbuUpdateStmt *pRbuUpdate;
+};
+
+/*
+** Values for RbuObjIter.eType
+**
+**     0: Table does not exist (error)
+**     1: Table has an implicit rowid.
+**     2: Table has an explicit IPK column.
+**     3: Table has an external PK index.
+**     4: Table is WITHOUT ROWID.
+**     5: Table is a virtual table.
+*/
+#define RBU_PK_NOTABLE        0
+#define RBU_PK_NONE           1
+#define RBU_PK_IPK            2
+#define RBU_PK_EXTERNAL       3
+#define RBU_PK_WITHOUT_ROWID  4
+#define RBU_PK_VTAB           5
+
+
+/*
+** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs
+** one of the following operations.
+*/
+#define RBU_INSERT     1          /* Insert on a main table b-tree */
+#define RBU_DELETE     2          /* Delete a row from a main table b-tree */
+#define RBU_REPLACE    3          /* Delete and then insert a row */
+#define RBU_IDX_DELETE 4          /* Delete a row from an aux. index b-tree */
+#define RBU_IDX_INSERT 5          /* Insert on an aux. index b-tree */
+
+#define RBU_UPDATE     6          /* Update a row in a main table b-tree */
+
+/*
+** A single step of an incremental checkpoint - frame iWalFrame of the wal
+** file should be copied to page iDbPage of the database file.
+*/
+struct RbuFrame {
+  u32 iDbPage;
+  u32 iWalFrame;
+};
+
+/*
+** RBU handle.
+**
+** nPhaseOneStep:
+**   If the RBU database contains an rbu_count table, this value is set to
+**   a running estimate of the number of b-tree operations required to 
+**   finish populating the *-oal file. This allows the sqlite3_bp_progress()
+**   API to calculate the permyriadage progress of populating the *-oal file
+**   using the formula:
+**
+**     permyriadage = (10000 * nProgress) / nPhaseOneStep
+**
+**   nPhaseOneStep is initialized to the sum of:
+**
+**     nRow * (nIndex + 1)
+**
+**   for all source tables in the RBU database, where nRow is the number
+**   of rows in the source table and nIndex the number of indexes on the
+**   corresponding target database table.
+**
+**   This estimate is accurate if the RBU update consists entirely of
+**   INSERT operations. However, it is inaccurate if:
+**
+**     * the RBU update contains any UPDATE operations. If the PK specified
+**       for an UPDATE operation does not exist in the target table, then
+**       no b-tree operations are required on index b-trees. Or if the 
+**       specified PK does exist, then (nIndex*2) such operations are
+**       required (one delete and one insert on each index b-tree).
+**
+**     * the RBU update contains any DELETE operations for which the specified
+**       PK does not exist. In this case no operations are required on index
+**       b-trees.
+**
+**     * the RBU update contains REPLACE operations. These are similar to
+**       UPDATE operations.
+**
+**   nPhaseOneStep is updated to account for the conditions above during the
+**   first pass of each source table. The updated nPhaseOneStep value is
+**   stored in the rbu_state table if the RBU update is suspended.
+*/
+struct sqlite3rbu {
+  int eStage;                     /* Value of RBU_STATE_STAGE field */
+  sqlite3 *dbMain;                /* target database handle */
+  sqlite3 *dbRbu;                 /* rbu database handle */
+  char *zTarget;                  /* Path to target db */
+  char *zRbu;                     /* Path to rbu db */
+  char *zState;                   /* Path to state db (or NULL if zRbu) */
+  char zStateDb[5];               /* Db name for state ("stat" or "main") */
+  int rc;                         /* Value returned by last rbu_step() call */
+  char *zErrmsg;                  /* Error message if rc!=SQLITE_OK */
+  int nStep;                      /* Rows processed for current object */
+  int nProgress;                  /* Rows processed for all objects */
+  RbuObjIter objiter;             /* Iterator for skipping through tbl/idx */
+  const char *zVfsName;           /* Name of automatically created rbu vfs */
+  rbu_file *pTargetFd;            /* File handle open on target db */
+  i64 iOalSz;
+  i64 nPhaseOneStep;
+
+  /* The following state variables are used as part of the incremental
+  ** checkpoint stage (eStage==RBU_STAGE_CKPT). See comments surrounding
+  ** function rbuSetupCheckpoint() for details.  */
+  u32 iMaxFrame;                  /* Largest iWalFrame value in aFrame[] */
+  u32 mLock;
+  int nFrame;                     /* Entries in aFrame[] array */
+  int nFrameAlloc;                /* Allocated size of aFrame[] array */
+  RbuFrame *aFrame;
+  int pgsz;
+  u8 *aBuf;
+  i64 iWalCksum;
+
+  /* Used in RBU vacuum mode only */
+  int nRbu;                       /* Number of RBU VFS in the stack */
+  rbu_file *pRbuFd;               /* Fd for main db of dbRbu */
+};
+
+/*
+** An rbu VFS is implemented using an instance of this structure.
+*/
+struct rbu_vfs {
+  sqlite3_vfs base;               /* rbu VFS shim methods */
+  sqlite3_vfs *pRealVfs;          /* Underlying VFS */
+  sqlite3_mutex *mutex;           /* Mutex to protect pMain */
+  rbu_file *pMain;                /* Linked list of main db files */
+};
+
+/*
+** Each file opened by an rbu VFS is represented by an instance of
+** the following structure.
+*/
+struct rbu_file {
+  sqlite3_file base;              /* sqlite3_file methods */
+  sqlite3_file *pReal;            /* Underlying file handle */
+  rbu_vfs *pRbuVfs;               /* Pointer to the rbu_vfs object */
+  sqlite3rbu *pRbu;               /* Pointer to rbu object (rbu target only) */
+
+  int openFlags;                  /* Flags this file was opened with */
+  u32 iCookie;                    /* Cookie value for main db files */
+  u8 iWriteVer;                   /* "write-version" value for main db files */
+  u8 bNolock;                     /* True to fail EXCLUSIVE locks */
+
+  int nShm;                       /* Number of entries in apShm[] array */
+  char **apShm;                   /* Array of mmap'd *-shm regions */
+  char *zDel;                     /* Delete this when closing file */
+
+  const char *zWal;               /* Wal filename for this main db file */
+  rbu_file *pWalFd;               /* Wal file descriptor for this main db */
+  rbu_file *pMainNext;            /* Next MAIN_DB file */
+};
+
+/*
+** True for an RBU vacuum handle, or false otherwise.
+*/
+#define rbuIsVacuum(p) ((p)->zTarget==0)
+
+
+/*************************************************************************
+** The following three functions, found below:
+**
+**   rbuDeltaGetInt()
+**   rbuDeltaChecksum()
+**   rbuDeltaApply()
+**
+** are lifted from the fossil source code (http://fossil-scm.org). They
+** are used to implement the scalar SQL function rbu_fossil_delta().
+*/
+
+/*
+** Read bytes from *pz and convert them into a positive integer.  When
+** finished, leave *pz pointing to the first character past the end of
+** the integer.  The *pLen parameter holds the length of the string
+** in *pz and is decremented once for each character in the integer.
+*/
+static unsigned int rbuDeltaGetInt(const char **pz, int *pLen){
+  static const signed char zValue[] = {
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+     0,  1,  2,  3,  4,  5,  6,  7,    8,  9, -1, -1, -1, -1, -1, -1,
+    -1, 10, 11, 12, 13, 14, 15, 16,   17, 18, 19, 20, 21, 22, 23, 24,
+    25, 26, 27, 28, 29, 30, 31, 32,   33, 34, 35, -1, -1, -1, -1, 36,
+    -1, 37, 38, 39, 40, 41, 42, 43,   44, 45, 46, 47, 48, 49, 50, 51,
+    52, 53, 54, 55, 56, 57, 58, 59,   60, 61, 62, -1, -1, -1, 63, -1,
+  };
+  unsigned int v = 0;
+  int c;
+  unsigned char *z = (unsigned char*)*pz;
+  unsigned char *zStart = z;
+  while( (c = zValue[0x7f&*(z++)])>=0 ){
+     v = (v<<6) + c;
+  }
+  z--;
+  *pLen -= z - zStart;
+  *pz = (char*)z;
+  return v;
+}
+
+/*
+** Compute a 32-bit checksum on the N-byte buffer.  Return the result.
+*/
+static unsigned int rbuDeltaChecksum(const char *zIn, size_t N){
+  const unsigned char *z = (const unsigned char *)zIn;
+  unsigned sum0 = 0;
+  unsigned sum1 = 0;
+  unsigned sum2 = 0;
+  unsigned sum3 = 0;
+  while(N >= 16){
+    sum0 += ((unsigned)z[0] + z[4] + z[8] + z[12]);
+    sum1 += ((unsigned)z[1] + z[5] + z[9] + z[13]);
+    sum2 += ((unsigned)z[2] + z[6] + z[10]+ z[14]);
+    sum3 += ((unsigned)z[3] + z[7] + z[11]+ z[15]);
+    z += 16;
+    N -= 16;
+  }
+  while(N >= 4){
+    sum0 += z[0];
+    sum1 += z[1];
+    sum2 += z[2];
+    sum3 += z[3];
+    z += 4;
+    N -= 4;
+  }
+  sum3 += (sum2 << 8) + (sum1 << 16) + (sum0 << 24);
+  switch(N){
+    case 3:   sum3 += (z[2] << 8);
+    case 2:   sum3 += (z[1] << 16);
+    case 1:   sum3 += (z[0] << 24);
+    default:  ;
+  }
+  return sum3;
+}
+
+/*
+** Apply a delta.
+**
+** The output buffer should be big enough to hold the whole output
+** file and a NUL terminator at the end.  The delta_output_size()
+** routine will determine this size for you.
+**
+** The delta string should be null-terminated.  But the delta string
+** may contain embedded NUL characters (if the input and output are
+** binary files) so we also have to pass in the length of the delta in
+** the lenDelta parameter.
+**
+** This function returns the size of the output file in bytes (excluding
+** the final NUL terminator character).  Except, if the delta string is
+** malformed or intended for use with a source file other than zSrc,
+** then this routine returns -1.
+**
+** Refer to the delta_create() documentation above for a description
+** of the delta file format.
+*/
+static int rbuDeltaApply(
+  const char *zSrc,      /* The source or pattern file */
+  int lenSrc,            /* Length of the source file */
+  const char *zDelta,    /* Delta to apply to the pattern */
+  int lenDelta,          /* Length of the delta */
+  char *zOut             /* Write the output into this preallocated buffer */
+){
+  unsigned int limit;
+  unsigned int total = 0;
+#ifndef FOSSIL_OMIT_DELTA_CKSUM_TEST
+  char *zOrigOut = zOut;
+#endif
+
+  limit = rbuDeltaGetInt(&zDelta, &lenDelta);
+  if( *zDelta!='\n' ){
+    /* ERROR: size integer not terminated by "\n" */
+    return -1;
+  }
+  zDelta++; lenDelta--;
+  while( *zDelta && lenDelta>0 ){
+    unsigned int cnt, ofst;
+    cnt = rbuDeltaGetInt(&zDelta, &lenDelta);
+    switch( zDelta[0] ){
+      case '@': {
+        zDelta++; lenDelta--;
+        ofst = rbuDeltaGetInt(&zDelta, &lenDelta);
+        if( lenDelta>0 && zDelta[0]!=',' ){
+          /* ERROR: copy command not terminated by ',' */
+          return -1;
+        }
+        zDelta++; lenDelta--;
+        total += cnt;
+        if( total>limit ){
+          /* ERROR: copy exceeds output file size */
+          return -1;
+        }
+        if( (int)(ofst+cnt) > lenSrc ){
+          /* ERROR: copy extends past end of input */
+          return -1;
+        }
+        memcpy(zOut, &zSrc[ofst], cnt);
+        zOut += cnt;
+        break;
+      }
+      case ':': {
+        zDelta++; lenDelta--;
+        total += cnt;
+        if( total>limit ){
+          /* ERROR:  insert command gives an output larger than predicted */
+          return -1;
+        }
+        if( (int)cnt>lenDelta ){
+          /* ERROR: insert count exceeds size of delta */
+          return -1;
+        }
+        memcpy(zOut, zDelta, cnt);
+        zOut += cnt;
+        zDelta += cnt;
+        lenDelta -= cnt;
+        break;
+      }
+      case ';': {
+        zDelta++; lenDelta--;
+        zOut[0] = 0;
+#ifndef FOSSIL_OMIT_DELTA_CKSUM_TEST
+        if( cnt!=rbuDeltaChecksum(zOrigOut, total) ){
+          /* ERROR:  bad checksum */
+          return -1;
+        }
+#endif
+        if( total!=limit ){
+          /* ERROR: generated size does not match predicted size */
+          return -1;
+        }
+        return total;
+      }
+      default: {
+        /* ERROR: unknown delta operator */
+        return -1;
+      }
+    }
+  }
+  /* ERROR: unterminated delta */
+  return -1;
+}
+
+static int rbuDeltaOutputSize(const char *zDelta, int lenDelta){
+  int size;
+  size = rbuDeltaGetInt(&zDelta, &lenDelta);
+  if( *zDelta!='\n' ){
+    /* ERROR: size integer not terminated by "\n" */
+    return -1;
+  }
+  return size;
+}
+
+/*
+** End of code taken from fossil.
+*************************************************************************/
+
+/*
+** Implementation of SQL scalar function rbu_fossil_delta().
+**
+** This function applies a fossil delta patch to a blob. Exactly two
+** arguments must be passed to this function. The first is the blob to
+** patch and the second the patch to apply. If no error occurs, this
+** function returns the patched blob.
+*/
+static void rbuFossilDeltaFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *aDelta;
+  int nDelta;
+  const char *aOrig;
+  int nOrig;
+
+  int nOut;
+  int nOut2;
+  char *aOut;
+
+  assert( argc==2 );
+
+  nOrig = sqlite3_value_bytes(argv[0]);
+  aOrig = (const char*)sqlite3_value_blob(argv[0]);
+  nDelta = sqlite3_value_bytes(argv[1]);
+  aDelta = (const char*)sqlite3_value_blob(argv[1]);
+
+  /* Figure out the size of the output */
+  nOut = rbuDeltaOutputSize(aDelta, nDelta);
+  if( nOut<0 ){
+    sqlite3_result_error(context, "corrupt fossil delta", -1);
+    return;
+  }
+
+  aOut = sqlite3_malloc(nOut+1);
+  if( aOut==0 ){
+    sqlite3_result_error_nomem(context);
+  }else{
+    nOut2 = rbuDeltaApply(aOrig, nOrig, aDelta, nDelta, aOut);
+    if( nOut2!=nOut ){
+      sqlite3_result_error(context, "corrupt fossil delta", -1);
+    }else{
+      sqlite3_result_blob(context, aOut, nOut, sqlite3_free);
+    }
+  }
+}
+
+
+/*
+** Prepare the SQL statement in buffer zSql against database handle db.
+** If successful, set *ppStmt to point to the new statement and return
+** SQLITE_OK. 
+**
+** Otherwise, if an error does occur, set *ppStmt to NULL and return
+** an SQLite error code. Additionally, set output variable *pzErrmsg to
+** point to a buffer containing an error message. It is the responsibility
+** of the caller to (eventually) free this buffer using sqlite3_free().
+*/
+static int prepareAndCollectError(
+  sqlite3 *db, 
+  sqlite3_stmt **ppStmt,
+  char **pzErrmsg,
+  const char *zSql
+){
+  int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
+  if( rc!=SQLITE_OK ){
+    *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+    *ppStmt = 0;
+  }
+  return rc;
+}
+
+/*
+** Reset the SQL statement passed as the first argument. Return a copy
+** of the value returned by sqlite3_reset().
+**
+** If an error has occurred, then set *pzErrmsg to point to a buffer
+** containing an error message. It is the responsibility of the caller
+** to eventually free this buffer using sqlite3_free().
+*/
+static int resetAndCollectError(sqlite3_stmt *pStmt, char **pzErrmsg){
+  int rc = sqlite3_reset(pStmt);
+  if( rc!=SQLITE_OK ){
+    *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(sqlite3_db_handle(pStmt)));
+  }
+  return rc;
+}
+
+/*
+** Unless it is NULL, argument zSql points to a buffer allocated using
+** sqlite3_malloc containing an SQL statement. This function prepares the SQL
+** statement against database db and frees the buffer. If statement 
+** compilation is successful, *ppStmt is set to point to the new statement 
+** handle and SQLITE_OK is returned. 
+**
+** Otherwise, if an error occurs, *ppStmt is set to NULL and an error code
+** returned. In this case, *pzErrmsg may also be set to point to an error
+** message. It is the responsibility of the caller to free this error message
+** buffer using sqlite3_free().
+**
+** If argument zSql is NULL, this function assumes that an OOM has occurred.
+** In this case SQLITE_NOMEM is returned and *ppStmt set to NULL.
+*/
+static int prepareFreeAndCollectError(
+  sqlite3 *db, 
+  sqlite3_stmt **ppStmt,
+  char **pzErrmsg,
+  char *zSql
+){
+  int rc;
+  assert( *pzErrmsg==0 );
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+    *ppStmt = 0;
+  }else{
+    rc = prepareAndCollectError(db, ppStmt, pzErrmsg, zSql);
+    sqlite3_free(zSql);
+  }
+  return rc;
+}
+
+/*
+** Free the RbuObjIter.azTblCol[] and RbuObjIter.abTblPk[] arrays allocated
+** by an earlier call to rbuObjIterCacheTableInfo().
+*/
+static void rbuObjIterFreeCols(RbuObjIter *pIter){
+  int i;
+  for(i=0; i<pIter->nTblCol; i++){
+    sqlite3_free(pIter->azTblCol[i]);
+    sqlite3_free(pIter->azTblType[i]);
+  }
+  sqlite3_free(pIter->azTblCol);
+  pIter->azTblCol = 0;
+  pIter->azTblType = 0;
+  pIter->aiSrcOrder = 0;
+  pIter->abTblPk = 0;
+  pIter->abNotNull = 0;
+  pIter->nTblCol = 0;
+  pIter->eType = 0;               /* Invalid value */
+}
+
+/*
+** Finalize all statements and free all allocations that are specific to
+** the current object (table/index pair).
+*/
+static void rbuObjIterClearStatements(RbuObjIter *pIter){
+  RbuUpdateStmt *pUp;
+
+  sqlite3_finalize(pIter->pSelect);
+  sqlite3_finalize(pIter->pInsert);
+  sqlite3_finalize(pIter->pDelete);
+  sqlite3_finalize(pIter->pTmpInsert);
+  pUp = pIter->pRbuUpdate;
+  while( pUp ){
+    RbuUpdateStmt *pTmp = pUp->pNext;
+    sqlite3_finalize(pUp->pUpdate);
+    sqlite3_free(pUp);
+    pUp = pTmp;
+  }
+  
+  pIter->pSelect = 0;
+  pIter->pInsert = 0;
+  pIter->pDelete = 0;
+  pIter->pRbuUpdate = 0;
+  pIter->pTmpInsert = 0;
+  pIter->nCol = 0;
+}
+
+/*
+** Clean up any resources allocated as part of the iterator object passed
+** as the only argument.
+*/
+static void rbuObjIterFinalize(RbuObjIter *pIter){
+  rbuObjIterClearStatements(pIter);
+  sqlite3_finalize(pIter->pTblIter);
+  sqlite3_finalize(pIter->pIdxIter);
+  rbuObjIterFreeCols(pIter);
+  memset(pIter, 0, sizeof(RbuObjIter));
+}
+
+/*
+** Advance the iterator to the next position.
+**
+** If no error occurs, SQLITE_OK is returned and the iterator is left 
+** pointing to the next entry. Otherwise, an error code and message is 
+** left in the RBU handle passed as the first argument. A copy of the 
+** error code is returned.
+*/
+static int rbuObjIterNext(sqlite3rbu *p, RbuObjIter *pIter){
+  int rc = p->rc;
+  if( rc==SQLITE_OK ){
+
+    /* Free any SQLite statements used while processing the previous object */ 
+    rbuObjIterClearStatements(pIter);
+    if( pIter->zIdx==0 ){
+      rc = sqlite3_exec(p->dbMain,
+          "DROP TRIGGER IF EXISTS temp.rbu_insert_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_update1_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_update2_tr;"
+          "DROP TRIGGER IF EXISTS temp.rbu_delete_tr;"
+          , 0, 0, &p->zErrmsg
+      );
+    }
+
+    if( rc==SQLITE_OK ){
+      if( pIter->bCleanup ){
+        rbuObjIterFreeCols(pIter);
+        pIter->bCleanup = 0;
+        rc = sqlite3_step(pIter->pTblIter);
+        if( rc!=SQLITE_ROW ){
+          rc = resetAndCollectError(pIter->pTblIter, &p->zErrmsg);
+          pIter->zTbl = 0;
+        }else{
+          pIter->zTbl = (const char*)sqlite3_column_text(pIter->pTblIter, 0);
+          pIter->zDataTbl = (const char*)sqlite3_column_text(pIter->pTblIter,1);
+          rc = (pIter->zDataTbl && pIter->zTbl) ? SQLITE_OK : SQLITE_NOMEM;
+        }
+      }else{
+        if( pIter->zIdx==0 ){
+          sqlite3_stmt *pIdx = pIter->pIdxIter;
+          rc = sqlite3_bind_text(pIdx, 1, pIter->zTbl, -1, SQLITE_STATIC);
+        }
+        if( rc==SQLITE_OK ){
+          rc = sqlite3_step(pIter->pIdxIter);
+          if( rc!=SQLITE_ROW ){
+            rc = resetAndCollectError(pIter->pIdxIter, &p->zErrmsg);
+            pIter->bCleanup = 1;
+            pIter->zIdx = 0;
+          }else{
+            pIter->zIdx = (const char*)sqlite3_column_text(pIter->pIdxIter, 0);
+            pIter->iTnum = sqlite3_column_int(pIter->pIdxIter, 1);
+            pIter->bUnique = sqlite3_column_int(pIter->pIdxIter, 2);
+            rc = pIter->zIdx ? SQLITE_OK : SQLITE_NOMEM;
+          }
+        }
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    rbuObjIterFinalize(pIter);
+    p->rc = rc;
+  }
+  return rc;
+}
+
+
+/*
+** The implementation of the rbu_target_name() SQL function. This function
+** accepts one or two arguments. The first argument is the name of a table -
+** the name of a table in the RBU database.  The second, if it is present, is 1
+** for a view or 0 for a table. 
+**
+** For a non-vacuum RBU handle, if the table name matches the pattern:
+**
+**     data[0-9]_<name>
+**
+** where <name> is any sequence of 1 or more characters, <name> is returned.
+** Otherwise, if the only argument does not match the above pattern, an SQL
+** NULL is returned.
+**
+**     "data_t1"     -> "t1"
+**     "data0123_t2" -> "t2"
+**     "dataAB_t3"   -> NULL
+**
+** For an rbu vacuum handle, a copy of the first argument is returned if
+** the second argument is either missing or 0 (not a view).
+*/
+static void rbuTargetNameFunc(
+  sqlite3_context *pCtx,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3rbu *p = sqlite3_user_data(pCtx);
+  const char *zIn;
+  assert( argc==1 || argc==2 );
+
+  zIn = (const char*)sqlite3_value_text(argv[0]);
+  if( zIn ){
+    if( rbuIsVacuum(p) ){
+      if( argc==1 || 0==sqlite3_value_int(argv[1]) ){
+        sqlite3_result_text(pCtx, zIn, -1, SQLITE_STATIC);
+      }
+    }else{
+      if( strlen(zIn)>4 && memcmp("data", zIn, 4)==0 ){
+        int i;
+        for(i=4; zIn[i]>='0' && zIn[i]<='9'; i++);
+        if( zIn[i]=='_' && zIn[i+1] ){
+          sqlite3_result_text(pCtx, &zIn[i+1], -1, SQLITE_STATIC);
+        }
+      }
+    }
+  }
+}
+
+/*
+** Initialize the iterator structure passed as the second argument.
+**
+** If no error occurs, SQLITE_OK is returned and the iterator is left 
+** pointing to the first entry. Otherwise, an error code and message is 
+** left in the RBU handle passed as the first argument. A copy of the 
+** error code is returned.
+*/
+static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){
+  int rc;
+  memset(pIter, 0, sizeof(RbuObjIter));
+
+  rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, 
+    sqlite3_mprintf(
+      "SELECT rbu_target_name(name, type='view') AS target, name "
+      "FROM sqlite_master "
+      "WHERE type IN ('table', 'view') AND target IS NOT NULL "
+      " %s "
+      "ORDER BY name"
+  , rbuIsVacuum(p) ? "AND rootpage!=0 AND rootpage IS NOT NULL" : ""));
+
+  if( rc==SQLITE_OK ){
+    rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg,
+        "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' "
+        "  FROM main.sqlite_master "
+        "  WHERE type='index' AND tbl_name = ?"
+    );
+  }
+
+  pIter->bCleanup = 1;
+  p->rc = rc;
+  return rbuObjIterNext(p, pIter);
+}
+
+/*
+** This is a wrapper around "sqlite3_mprintf(zFmt, ...)". If an OOM occurs,
+** an error code is stored in the RBU handle passed as the first argument.
+**
+** If an error has already occurred (p->rc is already set to something other
+** than SQLITE_OK), then this function returns NULL without modifying the
+** stored error code. In this case it still calls sqlite3_free() on any 
+** printf() parameters associated with %z conversions.
+*/
+static char *rbuMPrintf(sqlite3rbu *p, const char *zFmt, ...){
+  char *zSql = 0;
+  va_list ap;
+  va_start(ap, zFmt);
+  zSql = sqlite3_vmprintf(zFmt, ap);
+  if( p->rc==SQLITE_OK ){
+    if( zSql==0 ) p->rc = SQLITE_NOMEM;
+  }else{
+    sqlite3_free(zSql);
+    zSql = 0;
+  }
+  va_end(ap);
+  return zSql;
+}
+
+/*
+** Argument zFmt is a sqlite3_mprintf() style format string. The trailing
+** arguments are the usual subsitution values. This function performs
+** the printf() style substitutions and executes the result as an SQL
+** statement on the RBU handles database.
+**
+** If an error occurs, an error code and error message is stored in the
+** RBU handle. If an error has already occurred when this function is
+** called, it is a no-op.
+*/
+static int rbuMPrintfExec(sqlite3rbu *p, sqlite3 *db, const char *zFmt, ...){
+  va_list ap;
+  char *zSql;
+  va_start(ap, zFmt);
+  zSql = sqlite3_vmprintf(zFmt, ap);
+  if( p->rc==SQLITE_OK ){
+    if( zSql==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      p->rc = sqlite3_exec(db, zSql, 0, 0, &p->zErrmsg);
+    }
+  }
+  sqlite3_free(zSql);
+  va_end(ap);
+  return p->rc;
+}
+
+/*
+** Attempt to allocate and return a pointer to a zeroed block of nByte 
+** bytes. 
+**
+** If an error (i.e. an OOM condition) occurs, return NULL and leave an 
+** error code in the rbu handle passed as the first argument. Or, if an 
+** error has already occurred when this function is called, return NULL 
+** immediately without attempting the allocation or modifying the stored
+** error code.
+*/
+static void *rbuMalloc(sqlite3rbu *p, int nByte){
+  void *pRet = 0;
+  if( p->rc==SQLITE_OK ){
+    assert( nByte>0 );
+    pRet = sqlite3_malloc64(nByte);
+    if( pRet==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      memset(pRet, 0, nByte);
+    }
+  }
+  return pRet;
+}
+
+
+/*
+** Allocate and zero the pIter->azTblCol[] and abTblPk[] arrays so that
+** there is room for at least nCol elements. If an OOM occurs, store an
+** error code in the RBU handle passed as the first argument.
+*/
+static void rbuAllocateIterArrays(sqlite3rbu *p, RbuObjIter *pIter, int nCol){
+  int nByte = (2*sizeof(char*) + sizeof(int) + 3*sizeof(u8)) * nCol;
+  char **azNew;
+
+  azNew = (char**)rbuMalloc(p, nByte);
+  if( azNew ){
+    pIter->azTblCol = azNew;
+    pIter->azTblType = &azNew[nCol];
+    pIter->aiSrcOrder = (int*)&pIter->azTblType[nCol];
+    pIter->abTblPk = (u8*)&pIter->aiSrcOrder[nCol];
+    pIter->abNotNull = (u8*)&pIter->abTblPk[nCol];
+    pIter->abIndexed = (u8*)&pIter->abNotNull[nCol];
+  }
+}
+
+/*
+** The first argument must be a nul-terminated string. This function
+** returns a copy of the string in memory obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free this memory
+** using sqlite3_free().
+**
+** If an OOM condition is encountered when attempting to allocate memory,
+** output variable (*pRc) is set to SQLITE_NOMEM before returning. Otherwise,
+** if the allocation succeeds, (*pRc) is left unchanged.
+*/
+static char *rbuStrndup(const char *zStr, int *pRc){
+  char *zRet = 0;
+
+  assert( *pRc==SQLITE_OK );
+  if( zStr ){
+    size_t nCopy = strlen(zStr) + 1;
+    zRet = (char*)sqlite3_malloc64(nCopy);
+    if( zRet ){
+      memcpy(zRet, zStr, nCopy);
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+
+  return zRet;
+}
+
+/*
+** Finalize the statement passed as the second argument.
+**
+** If the sqlite3_finalize() call indicates that an error occurs, and the
+** rbu handle error code is not already set, set the error code and error
+** message accordingly.
+*/
+static void rbuFinalize(sqlite3rbu *p, sqlite3_stmt *pStmt){
+  sqlite3 *db = sqlite3_db_handle(pStmt);
+  int rc = sqlite3_finalize(pStmt);
+  if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){
+    p->rc = rc;
+    p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+  }
+}
+
+/* Determine the type of a table.
+**
+**   peType is of type (int*), a pointer to an output parameter of type
+**   (int). This call sets the output parameter as follows, depending
+**   on the type of the table specified by parameters dbName and zTbl.
+**
+**     RBU_PK_NOTABLE:       No such table.
+**     RBU_PK_NONE:          Table has an implicit rowid.
+**     RBU_PK_IPK:           Table has an explicit IPK column.
+**     RBU_PK_EXTERNAL:      Table has an external PK index.
+**     RBU_PK_WITHOUT_ROWID: Table is WITHOUT ROWID.
+**     RBU_PK_VTAB:          Table is a virtual table.
+**
+**   Argument *piPk is also of type (int*), and also points to an output
+**   parameter. Unless the table has an external primary key index 
+**   (i.e. unless *peType is set to 3), then *piPk is set to zero. Or,
+**   if the table does have an external primary key index, then *piPk
+**   is set to the root page number of the primary key index before
+**   returning.
+**
+** ALGORITHM:
+**
+**   if( no entry exists in sqlite_master ){
+**     return RBU_PK_NOTABLE
+**   }else if( sql for the entry starts with "CREATE VIRTUAL" ){
+**     return RBU_PK_VTAB
+**   }else if( "PRAGMA index_list()" for the table contains a "pk" index ){
+**     if( the index that is the pk exists in sqlite_master ){
+**       *piPK = rootpage of that index.
+**       return RBU_PK_EXTERNAL
+**     }else{
+**       return RBU_PK_WITHOUT_ROWID
+**     }
+**   }else if( "PRAGMA table_info()" lists one or more "pk" columns ){
+**     return RBU_PK_IPK
+**   }else{
+**     return RBU_PK_NONE
+**   }
+*/
+static void rbuTableType(
+  sqlite3rbu *p,
+  const char *zTab,
+  int *peType,
+  int *piTnum,
+  int *piPk
+){
+  /*
+  ** 0) SELECT count(*) FROM sqlite_master where name=%Q AND IsVirtual(%Q)
+  ** 1) PRAGMA index_list = ?
+  ** 2) SELECT count(*) FROM sqlite_master where name=%Q 
+  ** 3) PRAGMA table_info = ?
+  */
+  sqlite3_stmt *aStmt[4] = {0, 0, 0, 0};
+
+  *peType = RBU_PK_NOTABLE;
+  *piPk = 0;
+
+  assert( p->rc==SQLITE_OK );
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, 
+    sqlite3_mprintf(
+          "SELECT (sql LIKE 'create virtual%%'), rootpage"
+          "  FROM sqlite_master"
+          " WHERE name=%Q", zTab
+  ));
+  if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){
+    /* Either an error, or no such table. */
+    goto rbuTableType_end;
+  }
+  if( sqlite3_column_int(aStmt[0], 0) ){
+    *peType = RBU_PK_VTAB;                     /* virtual table */
+    goto rbuTableType_end;
+  }
+  *piTnum = sqlite3_column_int(aStmt[0], 1);
+
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[1], &p->zErrmsg, 
+    sqlite3_mprintf("PRAGMA index_list=%Q",zTab)
+  );
+  if( p->rc ) goto rbuTableType_end;
+  while( sqlite3_step(aStmt[1])==SQLITE_ROW ){
+    const u8 *zOrig = sqlite3_column_text(aStmt[1], 3);
+    const u8 *zIdx = sqlite3_column_text(aStmt[1], 1);
+    if( zOrig && zIdx && zOrig[0]=='p' ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, 
+          sqlite3_mprintf(
+            "SELECT rootpage FROM sqlite_master WHERE name = %Q", zIdx
+      ));
+      if( p->rc==SQLITE_OK ){
+        if( sqlite3_step(aStmt[2])==SQLITE_ROW ){
+          *piPk = sqlite3_column_int(aStmt[2], 0);
+          *peType = RBU_PK_EXTERNAL;
+        }else{
+          *peType = RBU_PK_WITHOUT_ROWID;
+        }
+      }
+      goto rbuTableType_end;
+    }
+  }
+
+  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[3], &p->zErrmsg, 
+    sqlite3_mprintf("PRAGMA table_info=%Q",zTab)
+  );
+  if( p->rc==SQLITE_OK ){
+    while( sqlite3_step(aStmt[3])==SQLITE_ROW ){
+      if( sqlite3_column_int(aStmt[3],5)>0 ){
+        *peType = RBU_PK_IPK;                /* explicit IPK column */
+        goto rbuTableType_end;
+      }
+    }
+    *peType = RBU_PK_NONE;
+  }
+
+rbuTableType_end: {
+    unsigned int i;
+    for(i=0; i<sizeof(aStmt)/sizeof(aStmt[0]); i++){
+      rbuFinalize(p, aStmt[i]);
+    }
+  }
+}
+
+/*
+** This is a helper function for rbuObjIterCacheTableInfo(). It populates
+** the pIter->abIndexed[] array.
+*/
+static void rbuObjIterCacheIndexedCols(sqlite3rbu *p, RbuObjIter *pIter){
+  sqlite3_stmt *pList = 0;
+  int bIndex = 0;
+
+  if( p->rc==SQLITE_OK ){
+    memcpy(pIter->abIndexed, pIter->abTblPk, sizeof(u8)*pIter->nTblCol);
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pList, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)
+    );
+  }
+
+  pIter->nIndex = 0;
+  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pList) ){
+    const char *zIdx = (const char*)sqlite3_column_text(pList, 1);
+    sqlite3_stmt *pXInfo = 0;
+    if( zIdx==0 ) break;
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+    );
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      int iCid = sqlite3_column_int(pXInfo, 1);
+      if( iCid>=0 ) pIter->abIndexed[iCid] = 1;
+    }
+    rbuFinalize(p, pXInfo);
+    bIndex = 1;
+    pIter->nIndex++;
+  }
+
+  if( pIter->eType==RBU_PK_WITHOUT_ROWID ){
+    /* "PRAGMA index_list" includes the main PK b-tree */
+    pIter->nIndex--;
+  }
+
+  rbuFinalize(p, pList);
+  if( bIndex==0 ) pIter->abIndexed = 0;
+}
+
+
+/*
+** If they are not already populated, populate the pIter->azTblCol[],
+** pIter->abTblPk[], pIter->nTblCol and pIter->bRowid variables according to
+** the table (not index) that the iterator currently points to.
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise. If
+** an error does occur, an error code and error message are also left in 
+** the RBU handle.
+*/
+static int rbuObjIterCacheTableInfo(sqlite3rbu *p, RbuObjIter *pIter){
+  if( pIter->azTblCol==0 ){
+    sqlite3_stmt *pStmt = 0;
+    int nCol = 0;
+    int i;                        /* for() loop iterator variable */
+    int bRbuRowid = 0;            /* If input table has column "rbu_rowid" */
+    int iOrder = 0;
+    int iTnum = 0;
+
+    /* Figure out the type of table this step will deal with. */
+    assert( pIter->eType==0 );
+    rbuTableType(p, pIter->zTbl, &pIter->eType, &iTnum, &pIter->iPkTnum);
+    if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_NOTABLE ){
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf("no such table: %s", pIter->zTbl);
+    }
+    if( p->rc ) return p->rc;
+    if( pIter->zIdx==0 ) pIter->iTnum = iTnum;
+
+    assert( pIter->eType==RBU_PK_NONE || pIter->eType==RBU_PK_IPK 
+         || pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_WITHOUT_ROWID
+         || pIter->eType==RBU_PK_VTAB
+    );
+
+    /* Populate the azTblCol[] and nTblCol variables based on the columns
+    ** of the input table. Ignore any input table columns that begin with
+    ** "rbu_".  */
+    p->rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 
+        sqlite3_mprintf("SELECT * FROM '%q'", pIter->zDataTbl)
+    );
+    if( p->rc==SQLITE_OK ){
+      nCol = sqlite3_column_count(pStmt);
+      rbuAllocateIterArrays(p, pIter, nCol);
+    }
+    for(i=0; p->rc==SQLITE_OK && i<nCol; i++){
+      const char *zName = (const char*)sqlite3_column_name(pStmt, i);
+      if( sqlite3_strnicmp("rbu_", zName, 4) ){
+        char *zCopy = rbuStrndup(zName, &p->rc);
+        pIter->aiSrcOrder[pIter->nTblCol] = pIter->nTblCol;
+        pIter->azTblCol[pIter->nTblCol++] = zCopy;
+      }
+      else if( 0==sqlite3_stricmp("rbu_rowid", zName) ){
+        bRbuRowid = 1;
+      }
+    }
+    sqlite3_finalize(pStmt);
+    pStmt = 0;
+
+    if( p->rc==SQLITE_OK
+     && rbuIsVacuum(p)==0
+     && bRbuRowid!=(pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE)
+    ){
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf(
+          "table %q %s rbu_rowid column", pIter->zDataTbl,
+          (bRbuRowid ? "may not have" : "requires")
+      );
+    }
+
+    /* Check that all non-HIDDEN columns in the destination table are also
+    ** present in the input table. Populate the abTblPk[], azTblType[] and
+    ** aiTblOrder[] arrays at the same time.  */
+    if( p->rc==SQLITE_OK ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &p->zErrmsg, 
+          sqlite3_mprintf("PRAGMA table_info(%Q)", pIter->zTbl)
+      );
+    }
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      const char *zName = (const char*)sqlite3_column_text(pStmt, 1);
+      if( zName==0 ) break;  /* An OOM - finalize() below returns S_NOMEM */
+      for(i=iOrder; i<pIter->nTblCol; i++){
+        if( 0==strcmp(zName, pIter->azTblCol[i]) ) break;
+      }
+      if( i==pIter->nTblCol ){
+        p->rc = SQLITE_ERROR;
+        p->zErrmsg = sqlite3_mprintf("column missing from %q: %s",
+            pIter->zDataTbl, zName
+        );
+      }else{
+        int iPk = sqlite3_column_int(pStmt, 5);
+        int bNotNull = sqlite3_column_int(pStmt, 3);
+        const char *zType = (const char*)sqlite3_column_text(pStmt, 2);
+
+        if( i!=iOrder ){
+          SWAP(int, pIter->aiSrcOrder[i], pIter->aiSrcOrder[iOrder]);
+          SWAP(char*, pIter->azTblCol[i], pIter->azTblCol[iOrder]);
+        }
+
+        pIter->azTblType[iOrder] = rbuStrndup(zType, &p->rc);
+        pIter->abTblPk[iOrder] = (iPk!=0);
+        pIter->abNotNull[iOrder] = (u8)bNotNull || (iPk!=0);
+        iOrder++;
+      }
+    }
+
+    rbuFinalize(p, pStmt);
+    rbuObjIterCacheIndexedCols(p, pIter);
+    assert( pIter->eType!=RBU_PK_VTAB || pIter->abIndexed==0 );
+    assert( pIter->eType!=RBU_PK_VTAB || pIter->nIndex==0 );
+  }
+
+  return p->rc;
+}
+
+/*
+** This function constructs and returns a pointer to a nul-terminated 
+** string containing some SQL clause or list based on one or more of the 
+** column names currently stored in the pIter->azTblCol[] array.
+*/
+static char *rbuObjIterGetCollist(
+  sqlite3rbu *p,                  /* RBU object */
+  RbuObjIter *pIter               /* Object iterator for column names */
+){
+  char *zList = 0;
+  const char *zSep = "";
+  int i;
+  for(i=0; i<pIter->nTblCol; i++){
+    const char *z = pIter->azTblCol[i];
+    zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z);
+    zSep = ", ";
+  }
+  return zList;
+}
+
+/*
+** This function is used to create a SELECT list (the list of SQL 
+** expressions that follows a SELECT keyword) for a SELECT statement 
+** used to read from an data_xxx or rbu_tmp_xxx table while updating the 
+** index object currently indicated by the iterator object passed as the 
+** second argument. A "PRAGMA index_xinfo = <idxname>" statement is used 
+** to obtain the required information.
+**
+** If the index is of the following form:
+**
+**   CREATE INDEX i1 ON t1(c, b COLLATE nocase);
+**
+** and "t1" is a table with an explicit INTEGER PRIMARY KEY column 
+** "ipk", the returned string is:
+**
+**   "`c` COLLATE 'BINARY', `b` COLLATE 'NOCASE', `ipk` COLLATE 'BINARY'"
+**
+** As well as the returned string, three other malloc'd strings are 
+** returned via output parameters. As follows:
+**
+**   pzImposterCols: ...
+**   pzImposterPk: ...
+**   pzWhere: ...
+*/
+static char *rbuObjIterGetIndexCols(
+  sqlite3rbu *p,                  /* RBU object */
+  RbuObjIter *pIter,              /* Object iterator for column names */
+  char **pzImposterCols,          /* OUT: Columns for imposter table */
+  char **pzImposterPk,            /* OUT: Imposter PK clause */
+  char **pzWhere,                 /* OUT: WHERE clause */
+  int *pnBind                     /* OUT: Trbul number of columns */
+){
+  int rc = p->rc;                 /* Error code */
+  int rc2;                        /* sqlite3_finalize() return code */
+  char *zRet = 0;                 /* String to return */
+  char *zImpCols = 0;             /* String to return via *pzImposterCols */
+  char *zImpPK = 0;               /* String to return via *pzImposterPK */
+  char *zWhere = 0;               /* String to return via *pzWhere */
+  int nBind = 0;                  /* Value to return via *pnBind */
+  const char *zCom = "";          /* Set to ", " later on */
+  const char *zAnd = "";          /* Set to " AND " later on */
+  sqlite3_stmt *pXInfo = 0;       /* PRAGMA index_xinfo = ? */
+
+  if( rc==SQLITE_OK ){
+    assert( p->zErrmsg==0 );
+    rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx)
+    );
+  }
+
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+    int iCid = sqlite3_column_int(pXInfo, 1);
+    int bDesc = sqlite3_column_int(pXInfo, 3);
+    const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);
+    const char *zCol;
+    const char *zType;
+
+    if( iCid<0 ){
+      /* An integer primary key. If the table has an explicit IPK, use
+      ** its name. Otherwise, use "rbu_rowid".  */
+      if( pIter->eType==RBU_PK_IPK ){
+        int i;
+        for(i=0; pIter->abTblPk[i]==0; i++);
+        assert( i<pIter->nTblCol );
+        zCol = pIter->azTblCol[i];
+      }else if( rbuIsVacuum(p) ){
+        zCol = "_rowid_";
+      }else{
+        zCol = "rbu_rowid";
+      }
+      zType = "INTEGER";
+    }else{
+      zCol = pIter->azTblCol[iCid];
+      zType = pIter->azTblType[iCid];
+    }
+
+    zRet = sqlite3_mprintf("%z%s\"%w\" COLLATE %Q", zRet, zCom, zCol, zCollate);
+    if( pIter->bUnique==0 || sqlite3_column_int(pXInfo, 5) ){
+      const char *zOrder = (bDesc ? " DESC" : "");
+      zImpPK = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\"%s", 
+          zImpPK, zCom, nBind, zCol, zOrder
+      );
+    }
+    zImpCols = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\" %s COLLATE %Q", 
+        zImpCols, zCom, nBind, zCol, zType, zCollate
+    );
+    zWhere = sqlite3_mprintf(
+        "%z%s\"rbu_imp_%d%w\" IS ?", zWhere, zAnd, nBind, zCol
+    );
+    if( zRet==0 || zImpPK==0 || zImpCols==0 || zWhere==0 ) rc = SQLITE_NOMEM;
+    zCom = ", ";
+    zAnd = " AND ";
+    nBind++;
+  }
+
+  rc2 = sqlite3_finalize(pXInfo);
+  if( rc==SQLITE_OK ) rc = rc2;
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(zRet);
+    sqlite3_free(zImpCols);
+    sqlite3_free(zImpPK);
+    sqlite3_free(zWhere);
+    zRet = 0;
+    zImpCols = 0;
+    zImpPK = 0;
+    zWhere = 0;
+    p->rc = rc;
+  }
+
+  *pzImposterCols = zImpCols;
+  *pzImposterPk = zImpPK;
+  *pzWhere = zWhere;
+  *pnBind = nBind;
+  return zRet;
+}
+
+/*
+** Assuming the current table columns are "a", "b" and "c", and the zObj
+** paramter is passed "old", return a string of the form:
+**
+**     "old.a, old.b, old.b"
+**
+** With the column names escaped.
+**
+** For tables with implicit rowids - RBU_PK_EXTERNAL and RBU_PK_NONE, append
+** the text ", old._rowid_" to the returned value.
+*/
+static char *rbuObjIterGetOldlist(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  const char *zObj
+){
+  char *zList = 0;
+  if( p->rc==SQLITE_OK && pIter->abIndexed ){
+    const char *zS = "";
+    int i;
+    for(i=0; i<pIter->nTblCol; i++){
+      if( pIter->abIndexed[i] ){
+        const char *zCol = pIter->azTblCol[i];
+        zList = sqlite3_mprintf("%z%s%s.\"%w\"", zList, zS, zObj, zCol);
+      }else{
+        zList = sqlite3_mprintf("%z%sNULL", zList, zS);
+      }
+      zS = ", ";
+      if( zList==0 ){
+        p->rc = SQLITE_NOMEM;
+        break;
+      }
+    }
+
+    /* For a table with implicit rowids, append "old._rowid_" to the list. */
+    if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+      zList = rbuMPrintf(p, "%z, %s._rowid_", zList, zObj);
+    }
+  }
+  return zList;
+}
+
+/*
+** Return an expression that can be used in a WHERE clause to match the
+** primary key of the current table. For example, if the table is:
+**
+**   CREATE TABLE t1(a, b, c, PRIMARY KEY(b, c));
+**
+** Return the string:
+**
+**   "b = ?1 AND c = ?2"
+*/
+static char *rbuObjIterGetWhere(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter
+){
+  char *zList = 0;
+  if( pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE ){
+    zList = rbuMPrintf(p, "_rowid_ = ?%d", pIter->nTblCol+1);
+  }else if( pIter->eType==RBU_PK_EXTERNAL ){
+    const char *zSep = "";
+    int i;
+    for(i=0; i<pIter->nTblCol; i++){
+      if( pIter->abTblPk[i] ){
+        zList = rbuMPrintf(p, "%z%sc%d=?%d", zList, zSep, i, i+1);
+        zSep = " AND ";
+      }
+    }
+    zList = rbuMPrintf(p, 
+        "_rowid_ = (SELECT id FROM rbu_imposter2 WHERE %z)", zList
+    );
+
+  }else{
+    const char *zSep = "";
+    int i;
+    for(i=0; i<pIter->nTblCol; i++){
+      if( pIter->abTblPk[i] ){
+        const char *zCol = pIter->azTblCol[i];
+        zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", zList, zSep, zCol, i+1);
+        zSep = " AND ";
+      }
+    }
+  }
+  return zList;
+}
+
+/*
+** The SELECT statement iterating through the keys for the current object
+** (p->objiter.pSelect) currently points to a valid row. However, there
+** is something wrong with the rbu_control value in the rbu_control value
+** stored in the (p->nCol+1)'th column. Set the error code and error message
+** of the RBU handle to something reflecting this.
+*/
+static void rbuBadControlError(sqlite3rbu *p){
+  p->rc = SQLITE_ERROR;
+  p->zErrmsg = sqlite3_mprintf("invalid rbu_control value");
+}
+
+
+/*
+** Return a nul-terminated string containing the comma separated list of
+** assignments that should be included following the "SET" keyword of
+** an UPDATE statement used to update the table object that the iterator
+** passed as the second argument currently points to if the rbu_control
+** column of the data_xxx table entry is set to zMask.
+**
+** The memory for the returned string is obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free it using
+** sqlite3_free(). 
+**
+** If an OOM error is encountered when allocating space for the new
+** string, an error code is left in the rbu handle passed as the first
+** argument and NULL is returned. Or, if an error has already occurred
+** when this function is called, NULL is returned immediately, without
+** attempting the allocation or modifying the stored error code.
+*/
+static char *rbuObjIterGetSetlist(
+  sqlite3rbu *p,
+  RbuObjIter *pIter,
+  const char *zMask
+){
+  char *zList = 0;
+  if( p->rc==SQLITE_OK ){
+    int i;
+
+    if( (int)strlen(zMask)!=pIter->nTblCol ){
+      rbuBadControlError(p);
+    }else{
+      const char *zSep = "";
+      for(i=0; i<pIter->nTblCol; i++){
+        char c = zMask[pIter->aiSrcOrder[i]];
+        if( c=='x' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", 
+              zList, zSep, pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
+        else if( c=='d' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_delta(\"%w\", ?%d)", 
+              zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
+        else if( c=='f' ){
+          zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_fossil_delta(\"%w\", ?%d)", 
+              zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1
+          );
+          zSep = ", ";
+        }
+      }
+    }
+  }
+  return zList;
+}
+
+/*
+** Return a nul-terminated string consisting of nByte comma separated
+** "?" expressions. For example, if nByte is 3, return a pointer to
+** a buffer containing the string "?,?,?".
+**
+** The memory for the returned string is obtained from sqlite3_malloc().
+** It is the responsibility of the caller to eventually free it using
+** sqlite3_free(). 
+**
+** If an OOM error is encountered when allocating space for the new
+** string, an error code is left in the rbu handle passed as the first
+** argument and NULL is returned. Or, if an error has already occurred
+** when this function is called, NULL is returned immediately, without
+** attempting the allocation or modifying the stored error code.
+*/
+static char *rbuObjIterGetBindlist(sqlite3rbu *p, int nBind){
+  char *zRet = 0;
+  int nByte = nBind*2 + 1;
+
+  zRet = (char*)rbuMalloc(p, nByte);
+  if( zRet ){
+    int i;
+    for(i=0; i<nBind; i++){
+      zRet[i*2] = '?';
+      zRet[i*2+1] = (i+1==nBind) ? '\0' : ',';
+    }
+  }
+  return zRet;
+}
+
+/*
+** The iterator currently points to a table (not index) of type 
+** RBU_PK_WITHOUT_ROWID. This function creates the PRIMARY KEY 
+** declaration for the corresponding imposter table. For example,
+** if the iterator points to a table created as:
+**
+**   CREATE TABLE t1(a, b, c, PRIMARY KEY(b, a DESC)) WITHOUT ROWID
+**
+** this function returns:
+**
+**   PRIMARY KEY("b", "a" DESC)
+*/
+static char *rbuWithoutRowidPK(sqlite3rbu *p, RbuObjIter *pIter){
+  char *z = 0;
+  assert( pIter->zIdx==0 );
+  if( p->rc==SQLITE_OK ){
+    const char *zSep = "PRIMARY KEY(";
+    sqlite3_stmt *pXList = 0;     /* PRAGMA index_list = (pIter->zTbl) */
+    sqlite3_stmt *pXInfo = 0;     /* PRAGMA index_xinfo = <pk-index> */
+   
+    p->rc = prepareFreeAndCollectError(p->dbMain, &pXList, &p->zErrmsg,
+        sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)
+    );
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXList) ){
+      const char *zOrig = (const char*)sqlite3_column_text(pXList,3);
+      if( zOrig && strcmp(zOrig, "pk")==0 ){
+        const char *zIdx = (const char*)sqlite3_column_text(pXList,1);
+        if( zIdx ){
+          p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+              sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+          );
+        }
+        break;
+      }
+    }
+    rbuFinalize(p, pXList);
+
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      if( sqlite3_column_int(pXInfo, 5) ){
+        /* int iCid = sqlite3_column_int(pXInfo, 0); */
+        const char *zCol = (const char*)sqlite3_column_text(pXInfo, 2);
+        const char *zDesc = sqlite3_column_int(pXInfo, 3) ? " DESC" : "";
+        z = rbuMPrintf(p, "%z%s\"%w\"%s", z, zSep, zCol, zDesc);
+        zSep = ", ";
+      }
+    }
+    z = rbuMPrintf(p, "%z)", z);
+    rbuFinalize(p, pXInfo);
+  }
+  return z;
+}
+
+/*
+** This function creates the second imposter table used when writing to
+** a table b-tree where the table has an external primary key. If the
+** iterator passed as the second argument does not currently point to
+** a table (not index) with an external primary key, this function is a
+** no-op. 
+**
+** Assuming the iterator does point to a table with an external PK, this
+** function creates a WITHOUT ROWID imposter table named "rbu_imposter2"
+** used to access that PK index. For example, if the target table is
+** declared as follows:
+**
+**   CREATE TABLE t1(a, b TEXT, c REAL, PRIMARY KEY(b, c));
+**
+** then the imposter table schema is:
+**
+**   CREATE TABLE rbu_imposter2(c1 TEXT, c2 REAL, id INTEGER) WITHOUT ROWID;
+**
+*/
+static void rbuCreateImposterTable2(sqlite3rbu *p, RbuObjIter *pIter){
+  if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_EXTERNAL ){
+    int tnum = pIter->iPkTnum;    /* Root page of PK index */
+    sqlite3_stmt *pQuery = 0;     /* SELECT name ... WHERE rootpage = $tnum */
+    const char *zIdx = 0;         /* Name of PK index */
+    sqlite3_stmt *pXInfo = 0;     /* PRAGMA main.index_xinfo = $zIdx */
+    const char *zComma = "";
+    char *zCols = 0;              /* Used to build up list of table cols */
+    char *zPk = 0;                /* Used to build up table PK declaration */
+
+    /* Figure out the name of the primary key index for the current table.
+    ** This is needed for the argument to "PRAGMA index_xinfo". Set
+    ** zIdx to point to a nul-terminated string containing this name. */
+    p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, 
+        "SELECT name FROM sqlite_master WHERE rootpage = ?"
+    );
+    if( p->rc==SQLITE_OK ){
+      sqlite3_bind_int(pQuery, 1, tnum);
+      if( SQLITE_ROW==sqlite3_step(pQuery) ){
+        zIdx = (const char*)sqlite3_column_text(pQuery, 0);
+      }
+    }
+    if( zIdx ){
+      p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,
+          sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)
+      );
+    }
+    rbuFinalize(p, pQuery);
+
+    while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){
+      int bKey = sqlite3_column_int(pXInfo, 5);
+      if( bKey ){
+        int iCid = sqlite3_column_int(pXInfo, 1);
+        int bDesc = sqlite3_column_int(pXInfo, 3);
+        const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);
+        zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %s", zCols, zComma, 
+            iCid, pIter->azTblType[iCid], zCollate
+        );
+        zPk = rbuMPrintf(p, "%z%sc%d%s", zPk, zComma, iCid, bDesc?" DESC":"");
+        zComma = ", ";
+      }
+    }
+    zCols = rbuMPrintf(p, "%z, id INTEGER", zCols);
+    rbuFinalize(p, pXInfo);
+
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);
+    rbuMPrintfExec(p, p->dbMain,
+        "CREATE TABLE rbu_imposter2(%z, PRIMARY KEY(%z)) WITHOUT ROWID", 
+        zCols, zPk
+    );
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
+  }
+}
+
+/*
+** If an error has already occurred when this function is called, it 
+** immediately returns zero (without doing any work). Or, if an error
+** occurs during the execution of this function, it sets the error code
+** in the sqlite3rbu object indicated by the first argument and returns
+** zero.
+**
+** The iterator passed as the second argument is guaranteed to point to
+** a table (not an index) when this function is called. This function
+** attempts to create any imposter table required to write to the main
+** table b-tree of the table before returning. Non-zero is returned if
+** an imposter table are created, or zero otherwise.
+**
+** An imposter table is required in all cases except RBU_PK_VTAB. Only
+** virtual tables are written to directly. The imposter table has the 
+** same schema as the actual target table (less any UNIQUE constraints). 
+** More precisely, the "same schema" means the same columns, types, 
+** collation sequences. For tables that do not have an external PRIMARY
+** KEY, it also means the same PRIMARY KEY declaration.
+*/
+static void rbuCreateImposterTable(sqlite3rbu *p, RbuObjIter *pIter){
+  if( p->rc==SQLITE_OK && pIter->eType!=RBU_PK_VTAB ){
+    int tnum = pIter->iTnum;
+    const char *zComma = "";
+    char *zSql = 0;
+    int iCol;
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);
+
+    for(iCol=0; p->rc==SQLITE_OK && iCol<pIter->nTblCol; iCol++){
+      const char *zPk = "";
+      const char *zCol = pIter->azTblCol[iCol];
+      const char *zColl = 0;
+
+      p->rc = sqlite3_table_column_metadata(
+          p->dbMain, "main", pIter->zTbl, zCol, 0, &zColl, 0, 0, 0
+      );
+
+      if( pIter->eType==RBU_PK_IPK && pIter->abTblPk[iCol] ){
+        /* If the target table column is an "INTEGER PRIMARY KEY", add
+        ** "PRIMARY KEY" to the imposter table column declaration. */
+        zPk = "PRIMARY KEY ";
+      }
+      zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %s%s", 
+          zSql, zComma, zCol, pIter->azTblType[iCol], zPk, zColl,
+          (pIter->abNotNull[iCol] ? " NOT NULL" : "")
+      );
+      zComma = ", ";
+    }
+
+    if( pIter->eType==RBU_PK_WITHOUT_ROWID ){
+      char *zPk = rbuWithoutRowidPK(p, pIter);
+      if( zPk ){
+        zSql = rbuMPrintf(p, "%z, %z", zSql, zPk);
+      }
+    }
+
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);
+    rbuMPrintfExec(p, p->dbMain, "CREATE TABLE \"rbu_imp_%w\"(%z)%s", 
+        pIter->zTbl, zSql, 
+        (pIter->eType==RBU_PK_WITHOUT_ROWID ? " WITHOUT ROWID" : "")
+    );
+    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
+  }
+}
+
+/*
+** Prepare a statement used to insert rows into the "rbu_tmp_xxx" table.
+** Specifically a statement of the form:
+**
+**     INSERT INTO rbu_tmp_xxx VALUES(?, ?, ? ...);
+**
+** The number of bound variables is equal to the number of columns in
+** the target table, plus one (for the rbu_control column), plus one more 
+** (for the rbu_rowid column) if the target table is an implicit IPK or 
+** virtual table.
+*/
+static void rbuObjIterPrepareTmpInsert(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  const char *zCollist,
+  const char *zRbuRowid
+){
+  int bRbuRowid = (pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE);
+  char *zBind = rbuObjIterGetBindlist(p, pIter->nTblCol + 1 + bRbuRowid);
+  if( zBind ){
+    assert( pIter->pTmpInsert==0 );
+    p->rc = prepareFreeAndCollectError(
+        p->dbRbu, &pIter->pTmpInsert, &p->zErrmsg, sqlite3_mprintf(
+          "INSERT INTO %s.'rbu_tmp_%q'(rbu_control,%s%s) VALUES(%z)", 
+          p->zStateDb, pIter->zDataTbl, zCollist, zRbuRowid, zBind
+    ));
+  }
+}
+
+static void rbuTmpInsertFunc(
+  sqlite3_context *pCtx, 
+  int nVal,
+  sqlite3_value **apVal
+){
+  sqlite3rbu *p = sqlite3_user_data(pCtx);
+  int rc = SQLITE_OK;
+  int i;
+
+  assert( sqlite3_value_int(apVal[0])!=0
+      || p->objiter.eType==RBU_PK_EXTERNAL 
+      || p->objiter.eType==RBU_PK_NONE 
+  );
+  if( sqlite3_value_int(apVal[0])!=0 ){
+    p->nPhaseOneStep += p->objiter.nIndex;
+  }
+
+  for(i=0; rc==SQLITE_OK && i<nVal; i++){
+    rc = sqlite3_bind_value(p->objiter.pTmpInsert, i+1, apVal[i]);
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3_step(p->objiter.pTmpInsert);
+    rc = sqlite3_reset(p->objiter.pTmpInsert);
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx, rc);
+  }
+}
+
+/*
+** Ensure that the SQLite statement handles required to update the 
+** target database object currently indicated by the iterator passed 
+** as the second argument are available.
+*/
+static int rbuObjIterPrepareAll(
+  sqlite3rbu *p, 
+  RbuObjIter *pIter,
+  int nOffset                     /* Add "LIMIT -1 OFFSET $nOffset" to SELECT */
+){
+  assert( pIter->bCleanup==0 );
+  if( pIter->pSelect==0 && rbuObjIterCacheTableInfo(p, pIter)==SQLITE_OK ){
+    const int tnum = pIter->iTnum;
+    char *zCollist = 0;           /* List of indexed columns */
+    char **pz = &p->zErrmsg;
+    const char *zIdx = pIter->zIdx;
+    char *zLimit = 0;
+
+    if( nOffset ){
+      zLimit = sqlite3_mprintf(" LIMIT -1 OFFSET %d", nOffset);
+      if( !zLimit ) p->rc = SQLITE_NOMEM;
+    }
+
+    if( zIdx ){
+      const char *zTbl = pIter->zTbl;
+      char *zImposterCols = 0;    /* Columns for imposter table */
+      char *zImposterPK = 0;      /* Primary key declaration for imposter */
+      char *zWhere = 0;           /* WHERE clause on PK columns */
+      char *zBind = 0;
+      int nBind = 0;
+
+      assert( pIter->eType!=RBU_PK_VTAB );
+      zCollist = rbuObjIterGetIndexCols(
+          p, pIter, &zImposterCols, &zImposterPK, &zWhere, &nBind
+      );
+      zBind = rbuObjIterGetBindlist(p, nBind);
+
+      /* Create the imposter table used to write to this index. */
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1,tnum);
+      rbuMPrintfExec(p, p->dbMain,
+          "CREATE TABLE \"rbu_imp_%w\"( %s, PRIMARY KEY( %s ) ) WITHOUT ROWID",
+          zTbl, zImposterCols, zImposterPK
+      );
+      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);
+
+      /* Create the statement to insert index entries */
+      pIter->nCol = nBind;
+      if( p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(
+            p->dbMain, &pIter->pInsert, &p->zErrmsg,
+          sqlite3_mprintf("INSERT INTO \"rbu_imp_%w\" VALUES(%s)", zTbl, zBind)
+        );
+      }
+
+      /* And to delete index entries */
+      if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(
+            p->dbMain, &pIter->pDelete, &p->zErrmsg,
+          sqlite3_mprintf("DELETE FROM \"rbu_imp_%w\" WHERE %s", zTbl, zWhere)
+        );
+      }
+
+      /* Create the SELECT statement to read keys in sorted order */
+      if( p->rc==SQLITE_OK ){
+        char *zSql;
+        if( rbuIsVacuum(p) ){
+          zSql = sqlite3_mprintf(
+              "SELECT %s, 0 AS rbu_control FROM '%q' ORDER BY %s%s",
+              zCollist, 
+              pIter->zDataTbl,
+              zCollist, zLimit
+          );
+        }else
+
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          zSql = sqlite3_mprintf(
+              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' ORDER BY %s%s",
+              zCollist, p->zStateDb, pIter->zDataTbl,
+              zCollist, zLimit
+          );
+        }else{
+          zSql = sqlite3_mprintf(
+              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' "
+              "UNION ALL "
+              "SELECT %s, rbu_control FROM '%q' "
+              "WHERE typeof(rbu_control)='integer' AND rbu_control!=1 "
+              "ORDER BY %s%s",
+              zCollist, p->zStateDb, pIter->zDataTbl, 
+              zCollist, pIter->zDataTbl, 
+              zCollist, zLimit
+          );
+        }
+        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, zSql);
+      }
+
+      sqlite3_free(zImposterCols);
+      sqlite3_free(zImposterPK);
+      sqlite3_free(zWhere);
+      sqlite3_free(zBind);
+    }else{
+      int bRbuRowid = (pIter->eType==RBU_PK_VTAB)
+                    ||(pIter->eType==RBU_PK_NONE)
+                    ||(pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p));
+      const char *zTbl = pIter->zTbl;       /* Table this step applies to */
+      const char *zWrite;                   /* Imposter table name */
+
+      char *zBindings = rbuObjIterGetBindlist(p, pIter->nTblCol + bRbuRowid);
+      char *zWhere = rbuObjIterGetWhere(p, pIter);
+      char *zOldlist = rbuObjIterGetOldlist(p, pIter, "old");
+      char *zNewlist = rbuObjIterGetOldlist(p, pIter, "new");
+
+      zCollist = rbuObjIterGetCollist(p, pIter);
+      pIter->nCol = pIter->nTblCol;
+
+      /* Create the imposter table or tables (if required). */
+      rbuCreateImposterTable(p, pIter);
+      rbuCreateImposterTable2(p, pIter);
+      zWrite = (pIter->eType==RBU_PK_VTAB ? "" : "rbu_imp_");
+
+      /* Create the INSERT statement to write to the target PK b-tree */
+      if( p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pInsert, pz,
+            sqlite3_mprintf(
+              "INSERT INTO \"%s%w\"(%s%s) VALUES(%s)", 
+              zWrite, zTbl, zCollist, (bRbuRowid ? ", _rowid_" : ""), zBindings
+            )
+        );
+      }
+
+      /* Create the DELETE statement to write to the target PK b-tree.
+      ** Because it only performs INSERT operations, this is not required for
+      ** an rbu vacuum handle.  */
+      if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){
+        p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pDelete, pz,
+            sqlite3_mprintf(
+              "DELETE FROM \"%s%w\" WHERE %s", zWrite, zTbl, zWhere
+            )
+        );
+      }
+
+      if( rbuIsVacuum(p)==0 && pIter->abIndexed ){
+        const char *zRbuRowid = "";
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          zRbuRowid = ", rbu_rowid";
+        }
+
+        /* Create the rbu_tmp_xxx table and the triggers to populate it. */
+        rbuMPrintfExec(p, p->dbRbu,
+            "CREATE TABLE IF NOT EXISTS %s.'rbu_tmp_%q' AS "
+            "SELECT *%s FROM '%q' WHERE 0;"
+            , p->zStateDb, pIter->zDataTbl
+            , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "")
+            , pIter->zDataTbl
+        );
+
+        rbuMPrintfExec(p, p->dbMain,
+            "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(3, %s);"
+            "END;"
+
+            "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(3, %s);"
+            "END;"
+
+            "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" "
+            "BEGIN "
+            "  SELECT rbu_tmp_insert(4, %s);"
+            "END;",
+            zWrite, zTbl, zOldlist,
+            zWrite, zTbl, zOldlist,
+            zWrite, zTbl, zNewlist
+        );
+
+        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
+          rbuMPrintfExec(p, p->dbMain,
+              "CREATE TEMP TRIGGER rbu_insert_tr AFTER INSERT ON \"%s%w\" "
+              "BEGIN "
+              "  SELECT rbu_tmp_insert(0, %s);"
+              "END;",
+              zWrite, zTbl, zNewlist
+          );
+        }
+
+        rbuObjIterPrepareTmpInsert(p, pIter, zCollist, zRbuRowid);
+      }
+
+      /* Create the SELECT statement to read keys from data_xxx */
+      if( p->rc==SQLITE_OK ){
+        const char *zRbuRowid = "";
+        if( bRbuRowid ){
+          zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid";
+        }
+        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz,
+            sqlite3_mprintf(
+              "SELECT %s,%s rbu_control%s FROM '%q'%s", 
+              zCollist, 
+              (rbuIsVacuum(p) ? "0 AS " : ""),
+              zRbuRowid,
+              pIter->zDataTbl, zLimit
+            )
+        );
+      }
+
+      sqlite3_free(zWhere);
+      sqlite3_free(zOldlist);
+      sqlite3_free(zNewlist);
+      sqlite3_free(zBindings);
+    }
+    sqlite3_free(zCollist);
+    sqlite3_free(zLimit);
+  }
+  
+  return p->rc;
+}
+
+/*
+** Set output variable *ppStmt to point to an UPDATE statement that may
+** be used to update the imposter table for the main table b-tree of the
+** table object that pIter currently points to, assuming that the 
+** rbu_control column of the data_xyz table contains zMask.
+** 
+** If the zMask string does not specify any columns to update, then this
+** is not an error. Output variable *ppStmt is set to NULL in this case.
+*/
+static int rbuGetUpdateStmt(
+  sqlite3rbu *p,                  /* RBU handle */
+  RbuObjIter *pIter,              /* Object iterator */
+  const char *zMask,              /* rbu_control value ('x.x.') */
+  sqlite3_stmt **ppStmt           /* OUT: UPDATE statement handle */
+){
+  RbuUpdateStmt **pp;
+  RbuUpdateStmt *pUp = 0;
+  int nUp = 0;
+
+  /* In case an error occurs */
+  *ppStmt = 0;
+
+  /* Search for an existing statement. If one is found, shift it to the front
+  ** of the LRU queue and return immediately. Otherwise, leave nUp pointing
+  ** to the number of statements currently in the cache and pUp to the
+  ** last object in the list.  */
+  for(pp=&pIter->pRbuUpdate; *pp; pp=&((*pp)->pNext)){
+    pUp = *pp;
+    if( strcmp(pUp->zMask, zMask)==0 ){
+      *pp = pUp->pNext;
+      pUp->pNext = pIter->pRbuUpdate;
+      pIter->pRbuUpdate = pUp;
+      *ppStmt = pUp->pUpdate; 
+      return SQLITE_OK;
+    }
+    nUp++;
+  }
+  assert( pUp==0 || pUp->pNext==0 );
+
+  if( nUp>=SQLITE_RBU_UPDATE_CACHESIZE ){
+    for(pp=&pIter->pRbuUpdate; *pp!=pUp; pp=&((*pp)->pNext));
+    *pp = 0;
+    sqlite3_finalize(pUp->pUpdate);
+    pUp->pUpdate = 0;
+  }else{
+    pUp = (RbuUpdateStmt*)rbuMalloc(p, sizeof(RbuUpdateStmt)+pIter->nTblCol+1);
+  }
+
+  if( pUp ){
+    char *zWhere = rbuObjIterGetWhere(p, pIter);
+    char *zSet = rbuObjIterGetSetlist(p, pIter, zMask);
+    char *zUpdate = 0;
+
+    pUp->zMask = (char*)&pUp[1];
+    memcpy(pUp->zMask, zMask, pIter->nTblCol);
+    pUp->pNext = pIter->pRbuUpdate;
+    pIter->pRbuUpdate = pUp;
+
+    if( zSet ){
+      const char *zPrefix = "";
+
+      if( pIter->eType!=RBU_PK_VTAB ) zPrefix = "rbu_imp_";
+      zUpdate = sqlite3_mprintf("UPDATE \"%s%w\" SET %s WHERE %s", 
+          zPrefix, pIter->zTbl, zSet, zWhere
+      );
+      p->rc = prepareFreeAndCollectError(
+          p->dbMain, &pUp->pUpdate, &p->zErrmsg, zUpdate
+      );
+      *ppStmt = pUp->pUpdate;
+    }
+    sqlite3_free(zWhere);
+    sqlite3_free(zSet);
+  }
+
+  return p->rc;
+}
+
+static sqlite3 *rbuOpenDbhandle(
+  sqlite3rbu *p, 
+  const char *zName, 
+  int bUseVfs
+){
+  sqlite3 *db = 0;
+  if( p->rc==SQLITE_OK ){
+    const int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_URI;
+    p->rc = sqlite3_open_v2(zName, &db, flags, bUseVfs ? p->zVfsName : 0);
+    if( p->rc ){
+      p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+      sqlite3_close(db);
+      db = 0;
+    }
+  }
+  return db;
+}
+
+/*
+** Free an RbuState object allocated by rbuLoadState().
+*/
+static void rbuFreeState(RbuState *p){
+  if( p ){
+    sqlite3_free(p->zTbl);
+    sqlite3_free(p->zIdx);
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Allocate an RbuState object and load the contents of the rbu_state 
+** table into it. Return a pointer to the new object. It is the 
+** responsibility of the caller to eventually free the object using
+** sqlite3_free().
+**
+** If an error occurs, leave an error code and message in the rbu handle
+** and return NULL.
+*/
+static RbuState *rbuLoadState(sqlite3rbu *p){
+  RbuState *pRet = 0;
+  sqlite3_stmt *pStmt = 0;
+  int rc;
+  int rc2;
+
+  pRet = (RbuState*)rbuMalloc(p, sizeof(RbuState));
+  if( pRet==0 ) return 0;
+
+  rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 
+      sqlite3_mprintf("SELECT k, v FROM %s.rbu_state", p->zStateDb)
+  );
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+    switch( sqlite3_column_int(pStmt, 0) ){
+      case RBU_STATE_STAGE:
+        pRet->eStage = sqlite3_column_int(pStmt, 1);
+        if( pRet->eStage!=RBU_STAGE_OAL
+         && pRet->eStage!=RBU_STAGE_MOVE
+         && pRet->eStage!=RBU_STAGE_CKPT
+        ){
+          p->rc = SQLITE_CORRUPT;
+        }
+        break;
+
+      case RBU_STATE_TBL:
+        pRet->zTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);
+        break;
+
+      case RBU_STATE_IDX:
+        pRet->zIdx = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);
+        break;
+
+      case RBU_STATE_ROW:
+        pRet->nRow = sqlite3_column_int(pStmt, 1);
+        break;
+
+      case RBU_STATE_PROGRESS:
+        pRet->nProgress = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_CKPT:
+        pRet->iWalCksum = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_COOKIE:
+        pRet->iCookie = (u32)sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_OALSZ:
+        pRet->iOalSz = (u32)sqlite3_column_int64(pStmt, 1);
+        break;
+
+      case RBU_STATE_PHASEONESTEP:
+        pRet->nPhaseOneStep = sqlite3_column_int64(pStmt, 1);
+        break;
+
+      default:
+        rc = SQLITE_CORRUPT;
+        break;
+    }
+  }
+  rc2 = sqlite3_finalize(pStmt);
+  if( rc==SQLITE_OK ) rc = rc2;
+
+  p->rc = rc;
+  return pRet;
+}
+
+
+/*
+** Open the database handle and attach the RBU database as "rbu". If an
+** error occurs, leave an error code and message in the RBU handle.
+*/
+static void rbuOpenDatabase(sqlite3rbu *p){
+  assert( p->rc==SQLITE_OK );
+  assert( p->dbMain==0 && p->dbRbu==0 );
+  assert( rbuIsVacuum(p) || p->zTarget!=0 );
+
+  /* Open the RBU database */
+  p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1);
+
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);
+  }
+
+  /* If using separate RBU and state databases, attach the state database to
+  ** the RBU db handle now.  */
+  if( p->zState ){
+    rbuMPrintfExec(p, p->dbRbu, "ATTACH %Q AS stat", p->zState);
+    memcpy(p->zStateDb, "stat", 4);
+  }else{
+    memcpy(p->zStateDb, "main", 4);
+  }
+
+#if 0
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, 0);
+  }
+#endif
+
+  /* If it has not already been created, create the rbu_state table */
+  rbuMPrintfExec(p, p->dbRbu, RBU_CREATE_STATE, p->zStateDb);
+
+#if 0
+  if( rbuIsVacuum(p) ){
+    if( p->rc==SQLITE_OK ){
+      int rc2;
+      int bOk = 0;
+      sqlite3_stmt *pCnt = 0;
+      p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg,
+          "SELECT count(*) FROM stat.sqlite_master"
+      );
+      if( p->rc==SQLITE_OK 
+       && sqlite3_step(pCnt)==SQLITE_ROW
+       && 1==sqlite3_column_int(pCnt, 0)
+      ){
+        bOk = 1;
+      }
+      rc2 = sqlite3_finalize(pCnt);
+      if( p->rc==SQLITE_OK ) p->rc = rc2;
+
+      if( p->rc==SQLITE_OK && bOk==0 ){
+        p->rc = SQLITE_ERROR;
+        p->zErrmsg = sqlite3_mprintf("invalid state database");
+      }
+    
+      if( p->rc==SQLITE_OK ){
+        p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0);
+      }
+    }
+  }
+#endif
+
+  if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){
+    int bOpen = 0;
+    int rc;
+    p->nRbu = 0;
+    p->pRbuFd = 0;
+    rc = sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);
+    if( rc!=SQLITE_NOTFOUND ) p->rc = rc;
+    if( p->eStage>=RBU_STAGE_MOVE ){
+      bOpen = 1;
+    }else{
+      RbuState *pState = rbuLoadState(p);
+      if( pState ){
+        bOpen = (pState->eStage>RBU_STAGE_MOVE);
+        rbuFreeState(pState);
+      }
+    }
+    if( bOpen ) p->dbMain = rbuOpenDbhandle(p, p->zRbu, p->nRbu<=1);
+  }
+
+  p->eStage = 0;
+  if( p->rc==SQLITE_OK && p->dbMain==0 ){
+    if( !rbuIsVacuum(p) ){
+      p->dbMain = rbuOpenDbhandle(p, p->zTarget, 1);
+    }else if( p->pRbuFd->pWalFd ){
+      p->rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf("cannot vacuum wal mode database");
+    }else{
+      char *zTarget;
+      char *zExtra = 0;
+      if( strlen(p->zRbu)>=5 && 0==memcmp("file:", p->zRbu, 5) ){
+        zExtra = &p->zRbu[5];
+        while( *zExtra ){
+          if( *zExtra++=='?' ) break;
+        }
+        if( *zExtra=='\0' ) zExtra = 0;
+      }
+
+      zTarget = sqlite3_mprintf("file:%s-vacuum?rbu_memory=1%s%s", 
+          sqlite3_db_filename(p->dbRbu, "main"),
+          (zExtra==0 ? "" : "&"), (zExtra==0 ? "" : zExtra)
+      );
+
+      if( zTarget==0 ){
+        p->rc = SQLITE_NOMEM;
+        return;
+      }
+      p->dbMain = rbuOpenDbhandle(p, zTarget, p->nRbu<=1);
+      sqlite3_free(zTarget);
+    }
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbMain, 
+        "rbu_tmp_insert", -1, SQLITE_UTF8, (void*)p, rbuTmpInsertFunc, 0, 0
+    );
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbMain, 
+        "rbu_fossil_delta", 2, SQLITE_UTF8, 0, rbuFossilDeltaFunc, 0, 0
+    );
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_create_function(p->dbRbu, 
+        "rbu_target_name", -1, SQLITE_UTF8, (void*)p, rbuTargetNameFunc, 0, 0
+    );
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
+  }
+  rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_master");
+
+  /* Mark the database file just opened as an RBU target database. If 
+  ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use.
+  ** This is an error.  */
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
+  }
+
+  if( p->rc==SQLITE_NOTFOUND ){
+    p->rc = SQLITE_ERROR;
+    p->zErrmsg = sqlite3_mprintf("rbu vfs not found");
+  }
+}
+
+/*
+** This routine is a copy of the sqlite3FileSuffix3() routine from the core.
+** It is a no-op unless SQLITE_ENABLE_8_3_NAMES is defined.
+**
+** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database
+** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and
+** if filename in z[] has a suffix (a.k.a. "extension") that is longer than
+** three characters, then shorten the suffix on z[] to be the last three
+** characters of the original suffix.
+**
+** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always
+** do the suffix shortening regardless of URI parameter.
+**
+** Examples:
+**
+**     test.db-journal    =>   test.nal
+**     test.db-wal        =>   test.wal
+**     test.db-shm        =>   test.shm
+**     test.db-mj7f3319fa =>   test.9fa
+*/
+static void rbuFileSuffix3(const char *zBase, char *z){
+#ifdef SQLITE_ENABLE_8_3_NAMES
+#if SQLITE_ENABLE_8_3_NAMES<2
+  if( sqlite3_uri_boolean(zBase, "8_3_names", 0) )
+#endif
+  {
+    int i, sz;
+    sz = (int)strlen(z)&0xffffff;
+    for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
+    if( z[i]=='.' && sz>i+4 ) memmove(&z[i+1], &z[sz-3], 4);
+  }
+#endif
+}
+
+/*
+** Return the current wal-index header checksum for the target database 
+** as a 64-bit integer.
+**
+** The checksum is store in the first page of xShmMap memory as an 8-byte 
+** blob starting at byte offset 40.
+*/
+static i64 rbuShmChecksum(sqlite3rbu *p){
+  i64 iRet = 0;
+  if( p->rc==SQLITE_OK ){
+    sqlite3_file *pDb = p->pTargetFd->pReal;
+    u32 volatile *ptr;
+    p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, (void volatile**)&ptr);
+    if( p->rc==SQLITE_OK ){
+      iRet = ((i64)ptr[10] << 32) + ptr[11];
+    }
+  }
+  return iRet;
+}
+
+/*
+** This function is called as part of initializing or reinitializing an
+** incremental checkpoint. 
+**
+** It populates the sqlite3rbu.aFrame[] array with the set of 
+** (wal frame -> db page) copy operations required to checkpoint the 
+** current wal file, and obtains the set of shm locks required to safely 
+** perform the copy operations directly on the file-system.
+**
+** If argument pState is not NULL, then the incremental checkpoint is
+** being resumed. In this case, if the checksum of the wal-index-header
+** following recovery is not the same as the checksum saved in the RbuState
+** object, then the rbu handle is set to DONE state. This occurs if some
+** other client appends a transaction to the wal file in the middle of
+** an incremental checkpoint.
+*/
+static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){
+
+  /* If pState is NULL, then the wal file may not have been opened and
+  ** recovered. Running a read-statement here to ensure that doing so
+  ** does not interfere with the "capture" process below.  */
+  if( pState==0 ){
+    p->eStage = 0;
+    if( p->rc==SQLITE_OK ){
+      p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_master", 0, 0, 0);
+    }
+  }
+
+  /* Assuming no error has occurred, run a "restart" checkpoint with the
+  ** sqlite3rbu.eStage variable set to CAPTURE. This turns on the following
+  ** special behaviour in the rbu VFS:
+  **
+  **   * If the exclusive shm WRITER or READ0 lock cannot be obtained,
+  **     the checkpoint fails with SQLITE_BUSY (normally SQLite would
+  **     proceed with running a passive checkpoint instead of failing).
+  **
+  **   * Attempts to read from the *-wal file or write to the database file
+  **     do not perform any IO. Instead, the frame/page combinations that
+  **     would be read/written are recorded in the sqlite3rbu.aFrame[]
+  **     array.
+  **
+  **   * Calls to xShmLock(UNLOCK) to release the exclusive shm WRITER, 
+  **     READ0 and CHECKPOINT locks taken as part of the checkpoint are
+  **     no-ops. These locks will not be released until the connection
+  **     is closed.
+  **
+  **   * Attempting to xSync() the database file causes an SQLITE_INTERNAL 
+  **     error.
+  **
+  ** As a result, unless an error (i.e. OOM or SQLITE_BUSY) occurs, the
+  ** checkpoint below fails with SQLITE_INTERNAL, and leaves the aFrame[]
+  ** array populated with a set of (frame -> page) mappings. Because the 
+  ** WRITER, CHECKPOINT and READ0 locks are still held, it is safe to copy 
+  ** data from the wal file into the database file according to the 
+  ** contents of aFrame[].
+  */
+  if( p->rc==SQLITE_OK ){
+    int rc2;
+    p->eStage = RBU_STAGE_CAPTURE;
+    rc2 = sqlite3_exec(p->dbMain, "PRAGMA main.wal_checkpoint=restart", 0, 0,0);
+    if( rc2!=SQLITE_INTERNAL ) p->rc = rc2;
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->eStage = RBU_STAGE_CKPT;
+    p->nStep = (pState ? pState->nRow : 0);
+    p->aBuf = rbuMalloc(p, p->pgsz);
+    p->iWalCksum = rbuShmChecksum(p);
+  }
+
+  if( p->rc==SQLITE_OK && pState && pState->iWalCksum!=p->iWalCksum ){
+    p->rc = SQLITE_DONE;
+    p->eStage = RBU_STAGE_DONE;
+  }
+}
+
+/*
+** Called when iAmt bytes are read from offset iOff of the wal file while
+** the rbu object is in capture mode. Record the frame number of the frame
+** being read in the aFrame[] array.
+*/
+static int rbuCaptureWalRead(sqlite3rbu *pRbu, i64 iOff, int iAmt){
+  const u32 mReq = (1<<WAL_LOCK_WRITE)|(1<<WAL_LOCK_CKPT)|(1<<WAL_LOCK_READ0);
+  u32 iFrame;
+
+  if( pRbu->mLock!=mReq ){
+    pRbu->rc = SQLITE_BUSY;
+    return SQLITE_INTERNAL;
+  }
+
+  pRbu->pgsz = iAmt;
+  if( pRbu->nFrame==pRbu->nFrameAlloc ){
+    int nNew = (pRbu->nFrameAlloc ? pRbu->nFrameAlloc : 64) * 2;
+    RbuFrame *aNew;
+    aNew = (RbuFrame*)sqlite3_realloc64(pRbu->aFrame, nNew * sizeof(RbuFrame));
+    if( aNew==0 ) return SQLITE_NOMEM;
+    pRbu->aFrame = aNew;
+    pRbu->nFrameAlloc = nNew;
+  }
+
+  iFrame = (u32)((iOff-32) / (i64)(iAmt+24)) + 1;
+  if( pRbu->iMaxFrame<iFrame ) pRbu->iMaxFrame = iFrame;
+  pRbu->aFrame[pRbu->nFrame].iWalFrame = iFrame;
+  pRbu->aFrame[pRbu->nFrame].iDbPage = 0;
+  pRbu->nFrame++;
+  return SQLITE_OK;
+}
+
+/*
+** Called when a page of data is written to offset iOff of the database
+** file while the rbu handle is in capture mode. Record the page number 
+** of the page being written in the aFrame[] array.
+*/
+static int rbuCaptureDbWrite(sqlite3rbu *pRbu, i64 iOff){
+  pRbu->aFrame[pRbu->nFrame-1].iDbPage = (u32)(iOff / pRbu->pgsz) + 1;
+  return SQLITE_OK;
+}
+
+/*
+** This is called as part of an incremental checkpoint operation. Copy
+** a single frame of data from the wal file into the database file, as
+** indicated by the RbuFrame object.
+*/
+static void rbuCheckpointFrame(sqlite3rbu *p, RbuFrame *pFrame){
+  sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal;
+  sqlite3_file *pDb = p->pTargetFd->pReal;
+  i64 iOff;
+
+  assert( p->rc==SQLITE_OK );
+  iOff = (i64)(pFrame->iWalFrame-1) * (p->pgsz + 24) + 32 + 24;
+  p->rc = pWal->pMethods->xRead(pWal, p->aBuf, p->pgsz, iOff);
+  if( p->rc ) return;
+
+  iOff = (i64)(pFrame->iDbPage-1) * p->pgsz;
+  p->rc = pDb->pMethods->xWrite(pDb, p->aBuf, p->pgsz, iOff);
+}
+
+
+/*
+** Take an EXCLUSIVE lock on the database file.
+*/
+static void rbuLockDatabase(sqlite3rbu *p){
+  sqlite3_file *pReal = p->pTargetFd->pReal;
+  assert( p->rc==SQLITE_OK );
+  p->rc = pReal->pMethods->xLock(pReal, SQLITE_LOCK_SHARED);
+  if( p->rc==SQLITE_OK ){
+    p->rc = pReal->pMethods->xLock(pReal, SQLITE_LOCK_EXCLUSIVE);
+  }
+}
+
+#if defined(_WIN32_WCE)
+static LPWSTR rbuWinUtf8ToUnicode(const char *zFilename){
+  int nChar;
+  LPWSTR zWideFilename;
+
+  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
+  if( nChar==0 ){
+    return 0;
+  }
+  zWideFilename = sqlite3_malloc64( nChar*sizeof(zWideFilename[0]) );
+  if( zWideFilename==0 ){
+    return 0;
+  }
+  memset(zWideFilename, 0, nChar*sizeof(zWideFilename[0]));
+  nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename,
+                                nChar);
+  if( nChar==0 ){
+    sqlite3_free(zWideFilename);
+    zWideFilename = 0;
+  }
+  return zWideFilename;
+}
+#endif
+
+/*
+** The RBU handle is currently in RBU_STAGE_OAL state, with a SHARED lock
+** on the database file. This proc moves the *-oal file to the *-wal path,
+** then reopens the database file (this time in vanilla, non-oal, WAL mode).
+** If an error occurs, leave an error code and error message in the rbu 
+** handle.
+*/
+static void rbuMoveOalFile(sqlite3rbu *p){
+  const char *zBase = sqlite3_db_filename(p->dbMain, "main");
+  const char *zMove = zBase;
+  char *zOal;
+  char *zWal;
+
+  if( rbuIsVacuum(p) ){
+    zMove = sqlite3_db_filename(p->dbRbu, "main");
+  }
+  zOal = sqlite3_mprintf("%s-oal", zMove);
+  zWal = sqlite3_mprintf("%s-wal", zMove);
+
+  assert( p->eStage==RBU_STAGE_MOVE );
+  assert( p->rc==SQLITE_OK && p->zErrmsg==0 );
+  if( zWal==0 || zOal==0 ){
+    p->rc = SQLITE_NOMEM;
+  }else{
+    /* Move the *-oal file to *-wal. At this point connection p->db is
+    ** holding a SHARED lock on the target database file (because it is
+    ** in WAL mode). So no other connection may be writing the db. 
+    **
+    ** In order to ensure that there are no database readers, an EXCLUSIVE
+    ** lock is obtained here before the *-oal is moved to *-wal.
+    */
+    rbuLockDatabase(p);
+    if( p->rc==SQLITE_OK ){
+      rbuFileSuffix3(zBase, zWal);
+      rbuFileSuffix3(zBase, zOal);
+
+      /* Re-open the databases. */
+      rbuObjIterFinalize(&p->objiter);
+      sqlite3_close(p->dbRbu);
+      sqlite3_close(p->dbMain);
+      p->dbMain = 0;
+      p->dbRbu = 0;
+
+#if defined(_WIN32_WCE)
+      {
+        LPWSTR zWideOal;
+        LPWSTR zWideWal;
+
+        zWideOal = rbuWinUtf8ToUnicode(zOal);
+        if( zWideOal ){
+          zWideWal = rbuWinUtf8ToUnicode(zWal);
+          if( zWideWal ){
+            if( MoveFileW(zWideOal, zWideWal) ){
+              p->rc = SQLITE_OK;
+            }else{
+              p->rc = SQLITE_IOERR;
+            }
+            sqlite3_free(zWideWal);
+          }else{
+            p->rc = SQLITE_IOERR_NOMEM;
+          }
+          sqlite3_free(zWideOal);
+        }else{
+          p->rc = SQLITE_IOERR_NOMEM;
+        }
+      }
+#else
+      p->rc = rename(zOal, zWal) ? SQLITE_IOERR : SQLITE_OK;
+#endif
+
+      if( p->rc==SQLITE_OK ){
+        rbuOpenDatabase(p);
+        rbuSetupCheckpoint(p, 0);
+      }
+    }
+  }
+
+  sqlite3_free(zWal);
+  sqlite3_free(zOal);
+}
+
+/*
+** The SELECT statement iterating through the keys for the current object
+** (p->objiter.pSelect) currently points to a valid row. This function
+** determines the type of operation requested by this row and returns
+** one of the following values to indicate the result:
+**
+**     * RBU_INSERT
+**     * RBU_DELETE
+**     * RBU_IDX_DELETE
+**     * RBU_UPDATE
+**
+** If RBU_UPDATE is returned, then output variable *pzMask is set to
+** point to the text value indicating the columns to update.
+**
+** If the rbu_control field contains an invalid value, an error code and
+** message are left in the RBU handle and zero returned.
+*/
+static int rbuStepType(sqlite3rbu *p, const char **pzMask){
+  int iCol = p->objiter.nCol;     /* Index of rbu_control column */
+  int res = 0;                    /* Return value */
+
+  switch( sqlite3_column_type(p->objiter.pSelect, iCol) ){
+    case SQLITE_INTEGER: {
+      int iVal = sqlite3_column_int(p->objiter.pSelect, iCol);
+      switch( iVal ){
+        case 0: res = RBU_INSERT;     break;
+        case 1: res = RBU_DELETE;     break;
+        case 2: res = RBU_REPLACE;    break;
+        case 3: res = RBU_IDX_DELETE; break;
+        case 4: res = RBU_IDX_INSERT; break;
+      }
+      break;
+    }
+
+    case SQLITE_TEXT: {
+      const unsigned char *z = sqlite3_column_text(p->objiter.pSelect, iCol);
+      if( z==0 ){
+        p->rc = SQLITE_NOMEM;
+      }else{
+        *pzMask = (const char*)z;
+      }
+      res = RBU_UPDATE;
+
+      break;
+    }
+
+    default:
+      break;
+  }
+
+  if( res==0 ){
+    rbuBadControlError(p);
+  }
+  return res;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** Assert that column iCol of statement pStmt is named zName.
+*/
+static void assertColumnName(sqlite3_stmt *pStmt, int iCol, const char *zName){
+  const char *zCol = sqlite3_column_name(pStmt, iCol);
+  assert( 0==sqlite3_stricmp(zName, zCol) );
+}
+#else
+# define assertColumnName(x,y,z)
+#endif
+
+/*
+** Argument eType must be one of RBU_INSERT, RBU_DELETE, RBU_IDX_INSERT or
+** RBU_IDX_DELETE. This function performs the work of a single
+** sqlite3rbu_step() call for the type of operation specified by eType.
+*/
+static void rbuStepOneOp(sqlite3rbu *p, int eType){
+  RbuObjIter *pIter = &p->objiter;
+  sqlite3_value *pVal;
+  sqlite3_stmt *pWriter;
+  int i;
+
+  assert( p->rc==SQLITE_OK );
+  assert( eType!=RBU_DELETE || pIter->zIdx==0 );
+  assert( eType==RBU_DELETE || eType==RBU_IDX_DELETE
+       || eType==RBU_INSERT || eType==RBU_IDX_INSERT
+  );
+
+  /* If this is a delete, decrement nPhaseOneStep by nIndex. If the DELETE
+  ** statement below does actually delete a row, nPhaseOneStep will be
+  ** incremented by the same amount when SQL function rbu_tmp_insert()
+  ** is invoked by the trigger.  */
+  if( eType==RBU_DELETE ){
+    p->nPhaseOneStep -= p->objiter.nIndex;
+  }
+
+  if( eType==RBU_IDX_DELETE || eType==RBU_DELETE ){
+    pWriter = pIter->pDelete;
+  }else{
+    pWriter = pIter->pInsert;
+  }
+
+  for(i=0; i<pIter->nCol; i++){
+    /* If this is an INSERT into a table b-tree and the table has an
+    ** explicit INTEGER PRIMARY KEY, check that this is not an attempt
+    ** to write a NULL into the IPK column. That is not permitted.  */
+    if( eType==RBU_INSERT 
+     && pIter->zIdx==0 && pIter->eType==RBU_PK_IPK && pIter->abTblPk[i] 
+     && sqlite3_column_type(pIter->pSelect, i)==SQLITE_NULL
+    ){
+      p->rc = SQLITE_MISMATCH;
+      p->zErrmsg = sqlite3_mprintf("datatype mismatch");
+      return;
+    }
+
+    if( eType==RBU_DELETE && pIter->abTblPk[i]==0 ){
+      continue;
+    }
+
+    pVal = sqlite3_column_value(pIter->pSelect, i);
+    p->rc = sqlite3_bind_value(pWriter, i+1, pVal);
+    if( p->rc ) return;
+  }
+  if( pIter->zIdx==0 ){
+    if( pIter->eType==RBU_PK_VTAB 
+     || pIter->eType==RBU_PK_NONE 
+     || (pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p)) 
+    ){
+      /* For a virtual table, or a table with no primary key, the 
+      ** SELECT statement is:
+      **
+      **   SELECT <cols>, rbu_control, rbu_rowid FROM ....
+      **
+      ** Hence column_value(pIter->nCol+1).
+      */
+      assertColumnName(pIter->pSelect, pIter->nCol+1, 
+          rbuIsVacuum(p) ? "rowid" : "rbu_rowid"
+      );
+      pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);
+      p->rc = sqlite3_bind_value(pWriter, pIter->nCol+1, pVal);
+    }
+  }
+  if( p->rc==SQLITE_OK ){
+    sqlite3_step(pWriter);
+    p->rc = resetAndCollectError(pWriter, &p->zErrmsg);
+  }
+}
+
+/*
+** This function does the work for an sqlite3rbu_step() call.
+**
+** The object-iterator (p->objiter) currently points to a valid object,
+** and the input cursor (p->objiter.pSelect) currently points to a valid
+** input row. Perform whatever processing is required and return.
+**
+** If no  error occurs, SQLITE_OK is returned. Otherwise, an error code
+** and message is left in the RBU handle and a copy of the error code
+** returned.
+*/
+static int rbuStep(sqlite3rbu *p){
+  RbuObjIter *pIter = &p->objiter;
+  const char *zMask = 0;
+  int eType = rbuStepType(p, &zMask);
+
+  if( eType ){
+    assert( eType==RBU_INSERT     || eType==RBU_DELETE
+         || eType==RBU_REPLACE    || eType==RBU_IDX_DELETE
+         || eType==RBU_IDX_INSERT || eType==RBU_UPDATE
+    );
+    assert( eType!=RBU_UPDATE || pIter->zIdx==0 );
+
+    if( pIter->zIdx==0 && (eType==RBU_IDX_DELETE || eType==RBU_IDX_INSERT) ){
+      rbuBadControlError(p);
+    }
+    else if( eType==RBU_REPLACE ){
+      if( pIter->zIdx==0 ){
+        p->nPhaseOneStep += p->objiter.nIndex;
+        rbuStepOneOp(p, RBU_DELETE);
+      }
+      if( p->rc==SQLITE_OK ) rbuStepOneOp(p, RBU_INSERT);
+    }
+    else if( eType!=RBU_UPDATE ){
+      rbuStepOneOp(p, eType);
+    }
+    else{
+      sqlite3_value *pVal;
+      sqlite3_stmt *pUpdate = 0;
+      assert( eType==RBU_UPDATE );
+      p->nPhaseOneStep -= p->objiter.nIndex;
+      rbuGetUpdateStmt(p, pIter, zMask, &pUpdate);
+      if( pUpdate ){
+        int i;
+        for(i=0; p->rc==SQLITE_OK && i<pIter->nCol; i++){
+          char c = zMask[pIter->aiSrcOrder[i]];
+          pVal = sqlite3_column_value(pIter->pSelect, i);
+          if( pIter->abTblPk[i] || c!='.' ){
+            p->rc = sqlite3_bind_value(pUpdate, i+1, pVal);
+          }
+        }
+        if( p->rc==SQLITE_OK 
+         && (pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) 
+        ){
+          /* Bind the rbu_rowid value to column _rowid_ */
+          assertColumnName(pIter->pSelect, pIter->nCol+1, "rbu_rowid");
+          pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);
+          p->rc = sqlite3_bind_value(pUpdate, pIter->nCol+1, pVal);
+        }
+        if( p->rc==SQLITE_OK ){
+          sqlite3_step(pUpdate);
+          p->rc = resetAndCollectError(pUpdate, &p->zErrmsg);
+        }
+      }
+    }
+  }
+  return p->rc;
+}
+
+/*
+** Increment the schema cookie of the main database opened by p->dbMain.
+**
+** Or, if this is an RBU vacuum, set the schema cookie of the main db
+** opened by p->dbMain to one more than the schema cookie of the main
+** db opened by p->dbRbu.
+*/
+static void rbuIncrSchemaCookie(sqlite3rbu *p){
+  if( p->rc==SQLITE_OK ){
+    sqlite3 *dbread = (rbuIsVacuum(p) ? p->dbRbu : p->dbMain);
+    int iCookie = 1000000;
+    sqlite3_stmt *pStmt;
+
+    p->rc = prepareAndCollectError(dbread, &pStmt, &p->zErrmsg, 
+        "PRAGMA schema_version"
+    );
+    if( p->rc==SQLITE_OK ){
+      /* Coverage: it may be that this sqlite3_step() cannot fail. There
+      ** is already a transaction open, so the prepared statement cannot
+      ** throw an SQLITE_SCHEMA exception. The only database page the
+      ** statement reads is page 1, which is guaranteed to be in the cache.
+      ** And no memory allocations are required.  */
+      if( SQLITE_ROW==sqlite3_step(pStmt) ){
+        iCookie = sqlite3_column_int(pStmt, 0);
+      }
+      rbuFinalize(p, pStmt);
+    }
+    if( p->rc==SQLITE_OK ){
+      rbuMPrintfExec(p, p->dbMain, "PRAGMA schema_version = %d", iCookie+1);
+    }
+  }
+}
+
+/*
+** Update the contents of the rbu_state table within the rbu database. The
+** value stored in the RBU_STATE_STAGE column is eStage. All other values
+** are determined by inspecting the rbu handle passed as the first argument.
+*/
+static void rbuSaveState(sqlite3rbu *p, int eStage){
+  if( p->rc==SQLITE_OK || p->rc==SQLITE_DONE ){
+    sqlite3_stmt *pInsert = 0;
+    rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd);
+    int rc;
+
+    assert( p->zErrmsg==0 );
+    rc = prepareFreeAndCollectError(p->dbRbu, &pInsert, &p->zErrmsg, 
+        sqlite3_mprintf(
+          "INSERT OR REPLACE INTO %s.rbu_state(k, v) VALUES "
+          "(%d, %d), "
+          "(%d, %Q), "
+          "(%d, %Q), "
+          "(%d, %d), "
+          "(%d, %d), "
+          "(%d, %lld), "
+          "(%d, %lld), "
+          "(%d, %lld), "
+          "(%d, %lld) ",
+          p->zStateDb,
+          RBU_STATE_STAGE, eStage,
+          RBU_STATE_TBL, p->objiter.zTbl, 
+          RBU_STATE_IDX, p->objiter.zIdx, 
+          RBU_STATE_ROW, p->nStep, 
+          RBU_STATE_PROGRESS, p->nProgress,
+          RBU_STATE_CKPT, p->iWalCksum,
+          RBU_STATE_COOKIE, (i64)pFd->iCookie,
+          RBU_STATE_OALSZ, p->iOalSz,
+          RBU_STATE_PHASEONESTEP, p->nPhaseOneStep
+      )
+    );
+    assert( pInsert==0 || rc==SQLITE_OK );
+
+    if( rc==SQLITE_OK ){
+      sqlite3_step(pInsert);
+      rc = sqlite3_finalize(pInsert);
+    }
+    if( rc!=SQLITE_OK ) p->rc = rc;
+  }
+}
+
+
+/*
+** The second argument passed to this function is the name of a PRAGMA 
+** setting - "page_size", "auto_vacuum", "user_version" or "application_id".
+** This function executes the following on sqlite3rbu.dbRbu:
+**
+**   "PRAGMA main.$zPragma"
+**
+** where $zPragma is the string passed as the second argument, then
+** on sqlite3rbu.dbMain:
+**
+**   "PRAGMA main.$zPragma = $val"
+**
+** where $val is the value returned by the first PRAGMA invocation.
+**
+** In short, it copies the value  of the specified PRAGMA setting from
+** dbRbu to dbMain.
+*/
+static void rbuCopyPragma(sqlite3rbu *p, const char *zPragma){
+  if( p->rc==SQLITE_OK ){
+    sqlite3_stmt *pPragma = 0;
+    p->rc = prepareFreeAndCollectError(p->dbRbu, &pPragma, &p->zErrmsg, 
+        sqlite3_mprintf("PRAGMA main.%s", zPragma)
+    );
+    if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pPragma) ){
+      p->rc = rbuMPrintfExec(p, p->dbMain, "PRAGMA main.%s = %d",
+          zPragma, sqlite3_column_int(pPragma, 0)
+      );
+    }
+    rbuFinalize(p, pPragma);
+  }
+}
+
+/*
+** The RBU handle passed as the only argument has just been opened and 
+** the state database is empty. If this RBU handle was opened for an
+** RBU vacuum operation, create the schema in the target db.
+*/
+static void rbuCreateTargetSchema(sqlite3rbu *p){
+  sqlite3_stmt *pSql = 0;
+  sqlite3_stmt *pInsert = 0;
+
+  assert( rbuIsVacuum(p) );
+  p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=1", 0,0, &p->zErrmsg);
+  if( p->rc==SQLITE_OK ){
+    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
+      "SELECT sql FROM sqlite_master WHERE sql!='' AND rootpage!=0"
+      " AND name!='sqlite_sequence' "
+      " ORDER BY type DESC"
+    );
+  }
+
+  while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){
+    const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
+    p->rc = sqlite3_exec(p->dbMain, zSql, 0, 0, &p->zErrmsg);
+  }
+  rbuFinalize(p, pSql);
+  if( p->rc!=SQLITE_OK ) return;
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
+        "SELECT * FROM sqlite_master WHERE rootpage=0 OR rootpage IS NULL" 
+    );
+  }
+
+  if( p->rc==SQLITE_OK ){
+    p->rc = prepareAndCollectError(p->dbMain, &pInsert, &p->zErrmsg, 
+        "INSERT INTO sqlite_master VALUES(?,?,?,?,?)"
+    );
+  }
+
+  while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){
+    int i;
+    for(i=0; i<5; i++){
+      sqlite3_bind_value(pInsert, i+1, sqlite3_column_value(pSql, i));
+    }
+    sqlite3_step(pInsert);
+    p->rc = sqlite3_reset(pInsert);
+  }
+  if( p->rc==SQLITE_OK ){
+    p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=0",0,0,&p->zErrmsg);
+  }
+
+  rbuFinalize(p, pSql);
+  rbuFinalize(p, pInsert);
+}
+
+/*
+** Step the RBU object.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_step(sqlite3rbu *p){
+  if( p ){
+    switch( p->eStage ){
+      case RBU_STAGE_OAL: {
+        RbuObjIter *pIter = &p->objiter;
+
+        /* If this is an RBU vacuum operation and the state table was empty
+        ** when this handle was opened, create the target database schema. */
+        if( rbuIsVacuum(p) && p->nProgress==0 && p->rc==SQLITE_OK ){
+          rbuCreateTargetSchema(p);
+          rbuCopyPragma(p, "user_version");
+          rbuCopyPragma(p, "application_id");
+        }
+
+        while( p->rc==SQLITE_OK && pIter->zTbl ){
+
+          if( pIter->bCleanup ){
+            /* Clean up the rbu_tmp_xxx table for the previous table. It 
+            ** cannot be dropped as there are currently active SQL statements.
+            ** But the contents can be deleted.  */
+            if( rbuIsVacuum(p)==0 && pIter->abIndexed ){
+              rbuMPrintfExec(p, p->dbRbu, 
+                  "DELETE FROM %s.'rbu_tmp_%q'", p->zStateDb, pIter->zDataTbl
+              );
+            }
+          }else{
+            rbuObjIterPrepareAll(p, pIter, 0);
+
+            /* Advance to the next row to process. */
+            if( p->rc==SQLITE_OK ){
+              int rc = sqlite3_step(pIter->pSelect);
+              if( rc==SQLITE_ROW ){
+                p->nProgress++;
+                p->nStep++;
+                return rbuStep(p);
+              }
+              p->rc = sqlite3_reset(pIter->pSelect);
+              p->nStep = 0;
+            }
+          }
+
+          rbuObjIterNext(p, pIter);
+        }
+
+        if( p->rc==SQLITE_OK ){
+          assert( pIter->zTbl==0 );
+          rbuSaveState(p, RBU_STAGE_MOVE);
+          rbuIncrSchemaCookie(p);
+          if( p->rc==SQLITE_OK ){
+            p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg);
+          }
+          if( p->rc==SQLITE_OK ){
+            p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg);
+          }
+          p->eStage = RBU_STAGE_MOVE;
+        }
+        break;
+      }
+
+      case RBU_STAGE_MOVE: {
+        if( p->rc==SQLITE_OK ){
+          rbuMoveOalFile(p);
+          p->nProgress++;
+        }
+        break;
+      }
+
+      case RBU_STAGE_CKPT: {
+        if( p->rc==SQLITE_OK ){
+          if( p->nStep>=p->nFrame ){
+            sqlite3_file *pDb = p->pTargetFd->pReal;
+  
+            /* Sync the db file */
+            p->rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL);
+  
+            /* Update nBackfill */
+            if( p->rc==SQLITE_OK ){
+              void volatile *ptr;
+              p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, &ptr);
+              if( p->rc==SQLITE_OK ){
+                ((u32 volatile*)ptr)[24] = p->iMaxFrame;
+              }
+            }
+  
+            if( p->rc==SQLITE_OK ){
+              p->eStage = RBU_STAGE_DONE;
+              p->rc = SQLITE_DONE;
+            }
+          }else{
+            RbuFrame *pFrame = &p->aFrame[p->nStep];
+            rbuCheckpointFrame(p, pFrame);
+            p->nStep++;
+          }
+          p->nProgress++;
+        }
+        break;
+      }
+
+      default:
+        break;
+    }
+    return p->rc;
+  }else{
+    return SQLITE_NOMEM;
+  }
+}
+
+/*
+** Compare strings z1 and z2, returning 0 if they are identical, or non-zero
+** otherwise. Either or both argument may be NULL. Two NULL values are
+** considered equal, and NULL is considered distinct from all other values.
+*/
+static int rbuStrCompare(const char *z1, const char *z2){
+  if( z1==0 && z2==0 ) return 0;
+  if( z1==0 || z2==0 ) return 1;
+  return (sqlite3_stricmp(z1, z2)!=0);
+}
+
+/*
+** This function is called as part of sqlite3rbu_open() when initializing
+** an rbu handle in OAL stage. If the rbu update has not started (i.e.
+** the rbu_state table was empty) it is a no-op. Otherwise, it arranges
+** things so that the next call to sqlite3rbu_step() continues on from
+** where the previous rbu handle left off.
+**
+** If an error occurs, an error code and error message are left in the
+** rbu handle passed as the first argument.
+*/
+static void rbuSetupOal(sqlite3rbu *p, RbuState *pState){
+  assert( p->rc==SQLITE_OK );
+  if( pState->zTbl ){
+    RbuObjIter *pIter = &p->objiter;
+    int rc = SQLITE_OK;
+
+    while( rc==SQLITE_OK && pIter->zTbl && (pIter->bCleanup 
+       || rbuStrCompare(pIter->zIdx, pState->zIdx)
+       || rbuStrCompare(pIter->zTbl, pState->zTbl) 
+    )){
+      rc = rbuObjIterNext(p, pIter);
+    }
+
+    if( rc==SQLITE_OK && !pIter->zTbl ){
+      rc = SQLITE_ERROR;
+      p->zErrmsg = sqlite3_mprintf("rbu_state mismatch error");
+    }
+
+    if( rc==SQLITE_OK ){
+      p->nStep = pState->nRow;
+      rc = rbuObjIterPrepareAll(p, &p->objiter, p->nStep);
+    }
+
+    p->rc = rc;
+  }
+}
+
+/*
+** If there is a "*-oal" file in the file-system corresponding to the
+** target database in the file-system, delete it. If an error occurs,
+** leave an error code and error message in the rbu handle.
+*/
+static void rbuDeleteOalFile(sqlite3rbu *p){
+  char *zOal = rbuMPrintf(p, "%s-oal", p->zTarget);
+  if( zOal ){
+    sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
+    assert( pVfs && p->rc==SQLITE_OK && p->zErrmsg==0 );
+    pVfs->xDelete(pVfs, zOal, 0);
+    sqlite3_free(zOal);
+  }
+}
+
+/*
+** Allocate a private rbu VFS for the rbu handle passed as the only
+** argument. This VFS will be used unless the call to sqlite3rbu_open()
+** specified a URI with a vfs=? option in place of a target database
+** file name.
+*/
+static void rbuCreateVfs(sqlite3rbu *p){
+  int rnd;
+  char zRnd[64];
+
+  assert( p->rc==SQLITE_OK );
+  sqlite3_randomness(sizeof(int), (void*)&rnd);
+  sqlite3_snprintf(sizeof(zRnd), zRnd, "rbu_vfs_%d", rnd);
+  p->rc = sqlite3rbu_create_vfs(zRnd, 0);
+  if( p->rc==SQLITE_OK ){
+    sqlite3_vfs *pVfs = sqlite3_vfs_find(zRnd);
+    assert( pVfs );
+    p->zVfsName = pVfs->zName;
+  }
+}
+
+/*
+** Destroy the private VFS created for the rbu handle passed as the only
+** argument by an earlier call to rbuCreateVfs().
+*/
+static void rbuDeleteVfs(sqlite3rbu *p){
+  if( p->zVfsName ){
+    sqlite3rbu_destroy_vfs(p->zVfsName);
+    p->zVfsName = 0;
+  }
+}
+
+/*
+** This user-defined SQL function is invoked with a single argument - the
+** name of a table expected to appear in the target database. It returns
+** the number of auxilliary indexes on the table.
+*/
+static void rbuIndexCntFunc(
+  sqlite3_context *pCtx, 
+  int nVal,
+  sqlite3_value **apVal
+){
+  sqlite3rbu *p = (sqlite3rbu*)sqlite3_user_data(pCtx);
+  sqlite3_stmt *pStmt = 0;
+  char *zErrmsg = 0;
+  int rc;
+
+  assert( nVal==1 );
+  
+  rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &zErrmsg, 
+      sqlite3_mprintf("SELECT count(*) FROM sqlite_master "
+        "WHERE type='index' AND tbl_name = %Q", sqlite3_value_text(apVal[0]))
+  );
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error(pCtx, zErrmsg, -1);
+  }else{
+    int nIndex = 0;
+    if( SQLITE_ROW==sqlite3_step(pStmt) ){
+      nIndex = sqlite3_column_int(pStmt, 0);
+    }
+    rc = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ){
+      sqlite3_result_int(pCtx, nIndex);
+    }else{
+      sqlite3_result_error(pCtx, sqlite3_errmsg(p->dbMain), -1);
+    }
+  }
+
+  sqlite3_free(zErrmsg);
+}
+
+/*
+** If the RBU database contains the rbu_count table, use it to initialize
+** the sqlite3rbu.nPhaseOneStep variable. The schema of the rbu_count table
+** is assumed to contain the same columns as:
+**
+**   CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID;
+**
+** There should be one row in the table for each data_xxx table in the
+** database. The 'tbl' column should contain the name of a data_xxx table,
+** and the cnt column the number of rows it contains.
+**
+** sqlite3rbu.nPhaseOneStep is initialized to the sum of (1 + nIndex) * cnt
+** for all rows in the rbu_count table, where nIndex is the number of 
+** indexes on the corresponding target database table.
+*/
+static void rbuInitPhaseOneSteps(sqlite3rbu *p){
+  if( p->rc==SQLITE_OK ){
+    sqlite3_stmt *pStmt = 0;
+    int bExists = 0;                /* True if rbu_count exists */
+
+    p->nPhaseOneStep = -1;
+
+    p->rc = sqlite3_create_function(p->dbRbu, 
+        "rbu_index_cnt", 1, SQLITE_UTF8, (void*)p, rbuIndexCntFunc, 0, 0
+    );
+  
+    /* Check for the rbu_count table. If it does not exist, or if an error
+    ** occurs, nPhaseOneStep will be left set to -1. */
+    if( p->rc==SQLITE_OK ){
+      p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,
+          "SELECT 1 FROM sqlite_master WHERE tbl_name = 'rbu_count'"
+      );
+    }
+    if( p->rc==SQLITE_OK ){
+      if( SQLITE_ROW==sqlite3_step(pStmt) ){
+        bExists = 1;
+      }
+      p->rc = sqlite3_finalize(pStmt);
+    }
+  
+    if( p->rc==SQLITE_OK && bExists ){
+      p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,
+          "SELECT sum(cnt * (1 + rbu_index_cnt(rbu_target_name(tbl))))"
+          "FROM rbu_count"
+      );
+      if( p->rc==SQLITE_OK ){
+        if( SQLITE_ROW==sqlite3_step(pStmt) ){
+          p->nPhaseOneStep = sqlite3_column_int64(pStmt, 0);
+        }
+        p->rc = sqlite3_finalize(pStmt);
+      }
+    }
+  }
+}
+
+
+static sqlite3rbu *openRbuHandle(
+  const char *zTarget, 
+  const char *zRbu,
+  const char *zState
+){
+  sqlite3rbu *p;
+  size_t nTarget = zTarget ? strlen(zTarget) : 0;
+  size_t nRbu = strlen(zRbu);
+  size_t nState = zState ? strlen(zState) : 0;
+  size_t nByte = sizeof(sqlite3rbu) + nTarget+1 + nRbu+1+ nState+1;
+
+  p = (sqlite3rbu*)sqlite3_malloc64(nByte);
+  if( p ){
+    RbuState *pState = 0;
+
+    /* Create the custom VFS. */
+    memset(p, 0, sizeof(sqlite3rbu));
+    rbuCreateVfs(p);
+
+    /* Open the target, RBU and state databases */
+    if( p->rc==SQLITE_OK ){
+      char *pCsr = (char*)&p[1];
+      if( zTarget ){
+        p->zTarget = pCsr;
+        memcpy(p->zTarget, zTarget, nTarget+1);
+        pCsr += nTarget+1;
+      }
+      p->zRbu = pCsr;
+      memcpy(p->zRbu, zRbu, nRbu+1);
+      pCsr += nRbu+1;
+      if( zState ){
+        p->zState = pCsr;
+        memcpy(p->zState, zState, nState+1);
+      }
+      rbuOpenDatabase(p);
+    }
+
+    if( p->rc==SQLITE_OK ){
+      pState = rbuLoadState(p);
+      assert( pState || p->rc!=SQLITE_OK );
+      if( p->rc==SQLITE_OK ){
+
+        if( pState->eStage==0 ){ 
+          rbuDeleteOalFile(p);
+          rbuInitPhaseOneSteps(p);
+          p->eStage = RBU_STAGE_OAL;
+        }else{
+          p->eStage = pState->eStage;
+          p->nPhaseOneStep = pState->nPhaseOneStep;
+        }
+        p->nProgress = pState->nProgress;
+        p->iOalSz = pState->iOalSz;
+      }
+    }
+    assert( p->rc!=SQLITE_OK || p->eStage!=0 );
+
+    if( p->rc==SQLITE_OK && p->pTargetFd->pWalFd ){
+      if( p->eStage==RBU_STAGE_OAL ){
+        p->rc = SQLITE_ERROR;
+        p->zErrmsg = sqlite3_mprintf("cannot update wal mode database");
+      }else if( p->eStage==RBU_STAGE_MOVE ){
+        p->eStage = RBU_STAGE_CKPT;
+        p->nStep = 0;
+      }
+    }
+
+    if( p->rc==SQLITE_OK 
+     && (p->eStage==RBU_STAGE_OAL || p->eStage==RBU_STAGE_MOVE)
+     && pState->eStage!=0
+    ){
+      rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd);
+      if( pFd->iCookie!=pState->iCookie ){   
+        /* At this point (pTargetFd->iCookie) contains the value of the
+        ** change-counter cookie (the thing that gets incremented when a 
+        ** transaction is committed in rollback mode) currently stored on 
+        ** page 1 of the database file. */
+        p->rc = SQLITE_BUSY;
+        p->zErrmsg = sqlite3_mprintf("database modified during rbu %s",
+            (rbuIsVacuum(p) ? "vacuum" : "update")
+        );
+      }
+    }
+
+    if( p->rc==SQLITE_OK ){
+      if( p->eStage==RBU_STAGE_OAL ){
+        sqlite3 *db = p->dbMain;
+        p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, &p->zErrmsg);
+
+        /* Point the object iterator at the first object */
+        if( p->rc==SQLITE_OK ){
+          p->rc = rbuObjIterFirst(p, &p->objiter);
+        }
+
+        /* If the RBU database contains no data_xxx tables, declare the RBU
+        ** update finished.  */
+        if( p->rc==SQLITE_OK && p->objiter.zTbl==0 ){
+          p->rc = SQLITE_DONE;
+          p->eStage = RBU_STAGE_DONE;
+        }else{
+          if( p->rc==SQLITE_OK && pState->eStage==0 && rbuIsVacuum(p) ){
+            rbuCopyPragma(p, "page_size");
+            rbuCopyPragma(p, "auto_vacuum");
+          }
+
+          /* Open transactions both databases. The *-oal file is opened or
+          ** created at this point. */
+          if( p->rc==SQLITE_OK ){
+            p->rc = sqlite3_exec(db, "BEGIN IMMEDIATE", 0, 0, &p->zErrmsg);
+          }
+
+          /* Check if the main database is a zipvfs db. If it is, set the upper
+          ** level pager to use "journal_mode=off". This prevents it from 
+          ** generating a large journal using a temp file.  */
+          if( p->rc==SQLITE_OK ){
+            int frc = sqlite3_file_control(db, "main", SQLITE_FCNTL_ZIPVFS, 0);
+            if( frc==SQLITE_OK ){
+              p->rc = sqlite3_exec(
+                db, "PRAGMA journal_mode=off",0,0,&p->zErrmsg);
+            }
+          }
+
+          if( p->rc==SQLITE_OK ){
+            rbuSetupOal(p, pState);
+          }
+        }
+      }else if( p->eStage==RBU_STAGE_MOVE ){
+        /* no-op */
+      }else if( p->eStage==RBU_STAGE_CKPT ){
+        rbuSetupCheckpoint(p, pState);
+      }else if( p->eStage==RBU_STAGE_DONE ){
+        p->rc = SQLITE_DONE;
+      }else{
+        p->rc = SQLITE_CORRUPT;
+      }
+    }
+
+    rbuFreeState(pState);
+  }
+
+  return p;
+}
+
+/*
+** Open and return a new RBU handle. 
+*/
+SQLITE_API sqlite3rbu *SQLITE_STDCALL sqlite3rbu_open(
+  const char *zTarget, 
+  const char *zRbu,
+  const char *zState
+){
+  /* TODO: Check that zTarget and zRbu are non-NULL */
+  return openRbuHandle(zTarget, zRbu, zState);
+}
+
+/*
+** Open a handle to begin or resume an RBU VACUUM operation.
+*/
+SQLITE_API sqlite3rbu *SQLITE_STDCALL sqlite3rbu_vacuum(
+  const char *zTarget, 
+  const char *zState
+){
+  /* TODO: Check that both arguments are non-NULL */
+  return openRbuHandle(0, zTarget, zState);
+}
+
+/*
+** Return the database handle used by pRbu.
+*/
+SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3rbu_db(sqlite3rbu *pRbu, int bRbu){
+  sqlite3 *db = 0;
+  if( pRbu ){
+    db = (bRbu ? pRbu->dbRbu : pRbu->dbMain);
+  }
+  return db;
+}
+
+
+/*
+** If the error code currently stored in the RBU handle is SQLITE_CONSTRAINT,
+** then edit any error message string so as to remove all occurrences of
+** the pattern "rbu_imp_[0-9]*".
+*/
+static void rbuEditErrmsg(sqlite3rbu *p){
+  if( p->rc==SQLITE_CONSTRAINT && p->zErrmsg ){
+    unsigned int i;
+    size_t nErrmsg = strlen(p->zErrmsg);
+    for(i=0; i<(nErrmsg-8); i++){
+      if( memcmp(&p->zErrmsg[i], "rbu_imp_", 8)==0 ){
+        int nDel = 8;
+        while( p->zErrmsg[i+nDel]>='0' && p->zErrmsg[i+nDel]<='9' ) nDel++;
+        memmove(&p->zErrmsg[i], &p->zErrmsg[i+nDel], nErrmsg + 1 - i - nDel);
+        nErrmsg -= nDel;
+      }
+    }
+  }
+}
+
+/*
+** Close the RBU handle.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_close(sqlite3rbu *p, char **pzErrmsg){
+  int rc;
+  if( p ){
+
+    /* Commit the transaction to the *-oal file. */
+    if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){
+      p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg);
+    }
+
+    rbuSaveState(p, p->eStage);
+
+    if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){
+      p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg);
+    }
+
+    /* Close any open statement handles. */
+    rbuObjIterFinalize(&p->objiter);
+
+    /* If this is an RBU vacuum handle and the vacuum has either finished
+    ** successfully or encountered an error, delete the contents of the 
+    ** state table. This causes the next call to sqlite3rbu_vacuum() 
+    ** specifying the current target and state databases to start a new
+    ** vacuum from scratch.  */
+    if( rbuIsVacuum(p) && p->rc!=SQLITE_OK && p->dbRbu ){
+      int rc2 = sqlite3_exec(p->dbRbu, "DELETE FROM stat.rbu_state", 0, 0, 0);
+      if( p->rc==SQLITE_DONE && rc2!=SQLITE_OK ) p->rc = rc2;
+    }
+
+    /* Close the open database handle and VFS object. */
+    sqlite3_close(p->dbRbu);
+    sqlite3_close(p->dbMain);
+    rbuDeleteVfs(p);
+    sqlite3_free(p->aBuf);
+    sqlite3_free(p->aFrame);
+
+    rbuEditErrmsg(p);
+    rc = p->rc;
+    *pzErrmsg = p->zErrmsg;
+    sqlite3_free(p);
+  }else{
+    rc = SQLITE_NOMEM;
+    *pzErrmsg = 0;
+  }
+  return rc;
+}
+
+/*
+** Return the total number of key-value operations (inserts, deletes or 
+** updates) that have been performed on the target database since the
+** current RBU update was started.
+*/
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3rbu_progress(sqlite3rbu *pRbu){
+  return pRbu->nProgress;
+}
+
+/*
+** Return permyriadage progress indications for the two main stages of
+** an RBU update.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3rbu_bp_progress(sqlite3rbu *p, int *pnOne, int *pnTwo){
+  const int MAX_PROGRESS = 10000;
+  switch( p->eStage ){
+    case RBU_STAGE_OAL:
+      if( p->nPhaseOneStep>0 ){
+        *pnOne = (int)(MAX_PROGRESS * (i64)p->nProgress/(i64)p->nPhaseOneStep);
+      }else{
+        *pnOne = -1;
+      }
+      *pnTwo = 0;
+      break;
+
+    case RBU_STAGE_MOVE:
+      *pnOne = MAX_PROGRESS;
+      *pnTwo = 0;
+      break;
+
+    case RBU_STAGE_CKPT:
+      *pnOne = MAX_PROGRESS;
+      *pnTwo = (int)(MAX_PROGRESS * (i64)p->nStep / (i64)p->nFrame);
+      break;
+
+    case RBU_STAGE_DONE:
+      *pnOne = MAX_PROGRESS;
+      *pnTwo = MAX_PROGRESS;
+      break;
+
+    default:
+      assert( 0 );
+  }
+}
+
+/*
+** Return the current state of the RBU vacuum or update operation.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_state(sqlite3rbu *p){
+  int aRes[] = {
+    0, SQLITE_RBU_STATE_OAL, SQLITE_RBU_STATE_MOVE,
+    0, SQLITE_RBU_STATE_CHECKPOINT, SQLITE_RBU_STATE_DONE
+  };
+
+  assert( RBU_STAGE_OAL==1 );
+  assert( RBU_STAGE_MOVE==2 );
+  assert( RBU_STAGE_CKPT==4 );
+  assert( RBU_STAGE_DONE==5 );
+  assert( aRes[RBU_STAGE_OAL]==SQLITE_RBU_STATE_OAL );
+  assert( aRes[RBU_STAGE_MOVE]==SQLITE_RBU_STATE_MOVE );
+  assert( aRes[RBU_STAGE_CKPT]==SQLITE_RBU_STATE_CHECKPOINT );
+  assert( aRes[RBU_STAGE_DONE]==SQLITE_RBU_STATE_DONE );
+
+  if( p->rc!=SQLITE_OK && p->rc!=SQLITE_DONE ){
+    return SQLITE_RBU_STATE_ERROR;
+  }else{
+    assert( p->rc!=SQLITE_DONE || p->eStage==RBU_STAGE_DONE );
+    assert( p->eStage==RBU_STAGE_OAL
+         || p->eStage==RBU_STAGE_MOVE
+         || p->eStage==RBU_STAGE_CKPT
+         || p->eStage==RBU_STAGE_DONE
+    );
+    return aRes[p->eStage];
+  }
+}
+
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_savestate(sqlite3rbu *p){
+  int rc = p->rc;
+  if( rc==SQLITE_DONE ) return SQLITE_OK;
+
+  assert( p->eStage>=RBU_STAGE_OAL && p->eStage<=RBU_STAGE_DONE );
+  if( p->eStage==RBU_STAGE_OAL ){
+    assert( rc!=SQLITE_DONE );
+    if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, 0);
+  }
+
+  p->rc = rc;
+  rbuSaveState(p, p->eStage);
+  rc = p->rc;
+
+  if( p->eStage==RBU_STAGE_OAL ){
+    assert( rc!=SQLITE_DONE );
+    if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0);
+    if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbRbu, "BEGIN IMMEDIATE", 0, 0, 0);
+    if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "BEGIN IMMEDIATE", 0, 0,0);
+  }
+
+  p->rc = rc;
+  return rc;
+}
+
+/**************************************************************************
+** Beginning of RBU VFS shim methods. The VFS shim modifies the behaviour
+** of a standard VFS in the following ways:
+**
+** 1. Whenever the first page of a main database file is read or 
+**    written, the value of the change-counter cookie is stored in
+**    rbu_file.iCookie. Similarly, the value of the "write-version"
+**    database header field is stored in rbu_file.iWriteVer. This ensures
+**    that the values are always trustworthy within an open transaction.
+**
+** 2. Whenever an SQLITE_OPEN_WAL file is opened, the (rbu_file.pWalFd)
+**    member variable of the associated database file descriptor is set
+**    to point to the new file. A mutex protected linked list of all main 
+**    db fds opened using a particular RBU VFS is maintained at 
+**    rbu_vfs.pMain to facilitate this.
+**
+** 3. Using a new file-control "SQLITE_FCNTL_RBU", a main db rbu_file 
+**    object can be marked as the target database of an RBU update. This
+**    turns on the following extra special behaviour:
+**
+** 3a. If xAccess() is called to check if there exists a *-wal file 
+**     associated with an RBU target database currently in RBU_STAGE_OAL
+**     stage (preparing the *-oal file), the following special handling
+**     applies:
+**
+**      * if the *-wal file does exist, return SQLITE_CANTOPEN. An RBU
+**        target database may not be in wal mode already.
+**
+**      * if the *-wal file does not exist, set the output parameter to
+**        non-zero (to tell SQLite that it does exist) anyway.
+**
+**     Then, when xOpen() is called to open the *-wal file associated with
+**     the RBU target in RBU_STAGE_OAL stage, instead of opening the *-wal
+**     file, the rbu vfs opens the corresponding *-oal file instead. 
+**
+** 3b. The *-shm pages returned by xShmMap() for a target db file in
+**     RBU_STAGE_OAL mode are actually stored in heap memory. This is to
+**     avoid creating a *-shm file on disk. Additionally, xShmLock() calls
+**     are no-ops on target database files in RBU_STAGE_OAL mode. This is
+**     because assert() statements in some VFS implementations fail if 
+**     xShmLock() is called before xShmMap().
+**
+** 3c. If an EXCLUSIVE lock is attempted on a target database file in any
+**     mode except RBU_STAGE_DONE (all work completed and checkpointed), it 
+**     fails with an SQLITE_BUSY error. This is to stop RBU connections
+**     from automatically checkpointing a *-wal (or *-oal) file from within
+**     sqlite3_close().
+**
+** 3d. In RBU_STAGE_CAPTURE mode, all xRead() calls on the wal file, and
+**     all xWrite() calls on the target database file perform no IO. 
+**     Instead the frame and page numbers that would be read and written
+**     are recorded. Additionally, successful attempts to obtain exclusive
+**     xShmLock() WRITER, CHECKPOINTER and READ0 locks on the target 
+**     database file are recorded. xShmLock() calls to unlock the same
+**     locks are no-ops (so that once obtained, these locks are never
+**     relinquished). Finally, calls to xSync() on the target database
+**     file fail with SQLITE_INTERNAL errors.
+*/
+
+static void rbuUnlockShm(rbu_file *p){
+  if( p->pRbu ){
+    int (*xShmLock)(sqlite3_file*,int,int,int) = p->pReal->pMethods->xShmLock;
+    int i;
+    for(i=0; i<SQLITE_SHM_NLOCK;i++){
+      if( (1<<i) & p->pRbu->mLock ){
+        xShmLock(p->pReal, i, 1, SQLITE_SHM_UNLOCK|SQLITE_SHM_EXCLUSIVE);
+      }
+    }
+    p->pRbu->mLock = 0;
+  }
+}
+
+/*
+** Close an rbu file.
+*/
+static int rbuVfsClose(sqlite3_file *pFile){
+  rbu_file *p = (rbu_file*)pFile;
+  int rc;
+  int i;
+
+  /* Free the contents of the apShm[] array. And the array itself. */
+  for(i=0; i<p->nShm; i++){
+    sqlite3_free(p->apShm[i]);
+  }
+  sqlite3_free(p->apShm);
+  p->apShm = 0;
+  sqlite3_free(p->zDel);
+
+  if( p->openFlags & SQLITE_OPEN_MAIN_DB ){
+    rbu_file **pp;
+    sqlite3_mutex_enter(p->pRbuVfs->mutex);
+    for(pp=&p->pRbuVfs->pMain; *pp!=p; pp=&((*pp)->pMainNext));
+    *pp = p->pMainNext;
+    sqlite3_mutex_leave(p->pRbuVfs->mutex);
+    rbuUnlockShm(p);
+    p->pReal->pMethods->xShmUnmap(p->pReal, 0);
+  }
+
+  /* Close the underlying file handle */
+  rc = p->pReal->pMethods->xClose(p->pReal);
+  return rc;
+}
+
+
+/*
+** Read and return an unsigned 32-bit big-endian integer from the buffer 
+** passed as the only argument.
+*/
+static u32 rbuGetU32(u8 *aBuf){
+  return ((u32)aBuf[0] << 24)
+       + ((u32)aBuf[1] << 16)
+       + ((u32)aBuf[2] <<  8)
+       + ((u32)aBuf[3]);
+}
+
+/*
+** Write an unsigned 32-bit value in big-endian format to the supplied
+** buffer.
+*/
+static void rbuPutU32(u8 *aBuf, u32 iVal){
+  aBuf[0] = (iVal >> 24) & 0xFF;
+  aBuf[1] = (iVal >> 16) & 0xFF;
+  aBuf[2] = (iVal >>  8) & 0xFF;
+  aBuf[3] = (iVal >>  0) & 0xFF;
+}
+
+static void rbuPutU16(u8 *aBuf, u16 iVal){
+  aBuf[0] = (iVal >>  8) & 0xFF;
+  aBuf[1] = (iVal >>  0) & 0xFF;
+}
+
+/*
+** Read data from an rbuVfs-file.
+*/
+static int rbuVfsRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  rbu_file *p = (rbu_file*)pFile;
+  sqlite3rbu *pRbu = p->pRbu;
+  int rc;
+
+  if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){
+    assert( p->openFlags & SQLITE_OPEN_WAL );
+    rc = rbuCaptureWalRead(p->pRbu, iOfst, iAmt);
+  }else{
+    if( pRbu && pRbu->eStage==RBU_STAGE_OAL 
+     && (p->openFlags & SQLITE_OPEN_WAL) 
+     && iOfst>=pRbu->iOalSz 
+    ){
+      rc = SQLITE_OK;
+      memset(zBuf, 0, iAmt);
+    }else{
+      rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
+#if 1
+      /* If this is being called to read the first page of the target 
+      ** database as part of an rbu vacuum operation, synthesize the 
+      ** contents of the first page if it does not yet exist. Otherwise,
+      ** SQLite will not check for a *-wal file.  */
+      if( pRbu && rbuIsVacuum(pRbu) 
+          && rc==SQLITE_IOERR_SHORT_READ && iOfst==0
+          && (p->openFlags & SQLITE_OPEN_MAIN_DB)
+          && pRbu->rc==SQLITE_OK
+      ){
+        sqlite3_file *pFd = (sqlite3_file*)pRbu->pRbuFd;
+        rc = pFd->pMethods->xRead(pFd, zBuf, iAmt, iOfst);
+        if( rc==SQLITE_OK ){
+          u8 *aBuf = (u8*)zBuf;
+          u32 iRoot = rbuGetU32(&aBuf[52]) ? 1 : 0;
+          rbuPutU32(&aBuf[52], iRoot);      /* largest root page number */
+          rbuPutU32(&aBuf[36], 0);          /* number of free pages */
+          rbuPutU32(&aBuf[32], 0);          /* first page on free list trunk */
+          rbuPutU32(&aBuf[28], 1);          /* size of db file in pages */
+          rbuPutU32(&aBuf[24], pRbu->pRbuFd->iCookie+1);  /* Change counter */
+
+          if( iAmt>100 ){
+            memset(&aBuf[100], 0, iAmt-100);
+            rbuPutU16(&aBuf[105], iAmt & 0xFFFF);
+            aBuf[100] = 0x0D;
+          }
+        }
+      }
+#endif
+    }
+    if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){
+      /* These look like magic numbers. But they are stable, as they are part
+       ** of the definition of the SQLite file format, which may not change. */
+      u8 *pBuf = (u8*)zBuf;
+      p->iCookie = rbuGetU32(&pBuf[24]);
+      p->iWriteVer = pBuf[19];
+    }
+  }
+  return rc;
+}
+
+/*
+** Write data to an rbuVfs-file.
+*/
+static int rbuVfsWrite(
+  sqlite3_file *pFile, 
+  const void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  rbu_file *p = (rbu_file*)pFile;
+  sqlite3rbu *pRbu = p->pRbu;
+  int rc;
+
+  if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){
+    assert( p->openFlags & SQLITE_OPEN_MAIN_DB );
+    rc = rbuCaptureDbWrite(p->pRbu, iOfst);
+  }else{
+    if( pRbu && pRbu->eStage==RBU_STAGE_OAL 
+     && (p->openFlags & SQLITE_OPEN_WAL) 
+     && iOfst>=pRbu->iOalSz
+    ){
+      pRbu->iOalSz = iAmt + iOfst;
+    }
+    rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst);
+    if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){
+      /* These look like magic numbers. But they are stable, as they are part
+      ** of the definition of the SQLite file format, which may not change. */
+      u8 *pBuf = (u8*)zBuf;
+      p->iCookie = rbuGetU32(&pBuf[24]);
+      p->iWriteVer = pBuf[19];
+    }
+  }
+  return rc;
+}
+
+/*
+** Truncate an rbuVfs-file.
+*/
+static int rbuVfsTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  rbu_file *p = (rbu_file*)pFile;
+  return p->pReal->pMethods->xTruncate(p->pReal, size);
+}
+
+/*
+** Sync an rbuVfs-file.
+*/
+static int rbuVfsSync(sqlite3_file *pFile, int flags){
+  rbu_file *p = (rbu_file *)pFile;
+  if( p->pRbu && p->pRbu->eStage==RBU_STAGE_CAPTURE ){
+    if( p->openFlags & SQLITE_OPEN_MAIN_DB ){
+      return SQLITE_INTERNAL;
+    }
+    return SQLITE_OK;
+  }
+  return p->pReal->pMethods->xSync(p->pReal, flags);
+}
+
+/*
+** Return the current file-size of an rbuVfs-file.
+*/
+static int rbuVfsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  rbu_file *p = (rbu_file *)pFile;
+  int rc;
+  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
+
+  /* If this is an RBU vacuum operation and this is the target database,
+  ** pretend that it has at least one page. Otherwise, SQLite will not
+  ** check for the existance of a *-wal file. rbuVfsRead() contains 
+  ** similar logic.  */
+  if( rc==SQLITE_OK && *pSize==0 
+   && p->pRbu && rbuIsVacuum(p->pRbu) 
+   && (p->openFlags & SQLITE_OPEN_MAIN_DB)
+  ){
+    *pSize = 1024;
+  }
+  return rc;
+}
+
+/*
+** Lock an rbuVfs-file.
+*/
+static int rbuVfsLock(sqlite3_file *pFile, int eLock){
+  rbu_file *p = (rbu_file*)pFile;
+  sqlite3rbu *pRbu = p->pRbu;
+  int rc = SQLITE_OK;
+
+  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
+  if( eLock==SQLITE_LOCK_EXCLUSIVE 
+   && (p->bNolock || (pRbu && pRbu->eStage!=RBU_STAGE_DONE))
+  ){
+    /* Do not allow EXCLUSIVE locks. Preventing SQLite from taking this 
+    ** prevents it from checkpointing the database from sqlite3_close(). */
+    rc = SQLITE_BUSY;
+  }else{
+    rc = p->pReal->pMethods->xLock(p->pReal, eLock);
+  }
+
+  return rc;
+}
+
+/*
+** Unlock an rbuVfs-file.
+*/
+static int rbuVfsUnlock(sqlite3_file *pFile, int eLock){
+  rbu_file *p = (rbu_file *)pFile;
+  return p->pReal->pMethods->xUnlock(p->pReal, eLock);
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an rbuVfs-file.
+*/
+static int rbuVfsCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  rbu_file *p = (rbu_file *)pFile;
+  return p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
+}
+
+/*
+** File control method. For custom operations on an rbuVfs-file.
+*/
+static int rbuVfsFileControl(sqlite3_file *pFile, int op, void *pArg){
+  rbu_file *p = (rbu_file *)pFile;
+  int (*xControl)(sqlite3_file*,int,void*) = p->pReal->pMethods->xFileControl;
+  int rc;
+
+  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB)
+       || p->openFlags & (SQLITE_OPEN_TRANSIENT_DB|SQLITE_OPEN_TEMP_JOURNAL)
+  );
+  if( op==SQLITE_FCNTL_RBU ){
+    sqlite3rbu *pRbu = (sqlite3rbu*)pArg;
+
+    /* First try to find another RBU vfs lower down in the vfs stack. If
+    ** one is found, this vfs will operate in pass-through mode. The lower
+    ** level vfs will do the special RBU handling.  */
+    rc = xControl(p->pReal, op, pArg);
+
+    if( rc==SQLITE_NOTFOUND ){
+      /* Now search for a zipvfs instance lower down in the VFS stack. If
+      ** one is found, this is an error.  */
+      void *dummy = 0;
+      rc = xControl(p->pReal, SQLITE_FCNTL_ZIPVFS, &dummy);
+      if( rc==SQLITE_OK ){
+        rc = SQLITE_ERROR;
+        pRbu->zErrmsg = sqlite3_mprintf("rbu/zipvfs setup error");
+      }else if( rc==SQLITE_NOTFOUND ){
+        pRbu->pTargetFd = p;
+        p->pRbu = pRbu;
+        if( p->pWalFd ) p->pWalFd->pRbu = pRbu;
+        rc = SQLITE_OK;
+      }
+    }
+    return rc;
+  }
+  else if( op==SQLITE_FCNTL_RBUCNT ){
+    sqlite3rbu *pRbu = (sqlite3rbu*)pArg;
+    pRbu->nRbu++;
+    pRbu->pRbuFd = p;
+    p->bNolock = 1;
+  }
+
+  rc = xControl(p->pReal, op, pArg);
+  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
+    rbu_vfs *pRbuVfs = p->pRbuVfs;
+    char *zIn = *(char**)pArg;
+    char *zOut = sqlite3_mprintf("rbu(%s)/%z", pRbuVfs->base.zName, zIn);
+    *(char**)pArg = zOut;
+    if( zOut==0 ) rc = SQLITE_NOMEM;
+  }
+
+  return rc;
+}
+
+/*
+** Return the sector-size in bytes for an rbuVfs-file.
+*/
+static int rbuVfsSectorSize(sqlite3_file *pFile){
+  rbu_file *p = (rbu_file *)pFile;
+  return p->pReal->pMethods->xSectorSize(p->pReal);
+}
+
+/*
+** Return the device characteristic flags supported by an rbuVfs-file.
+*/
+static int rbuVfsDeviceCharacteristics(sqlite3_file *pFile){
+  rbu_file *p = (rbu_file *)pFile;
+  return p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
+}
+
+/*
+** Take or release a shared-memory lock.
+*/
+static int rbuVfsShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
+  rbu_file *p = (rbu_file*)pFile;
+  sqlite3rbu *pRbu = p->pRbu;
+  int rc = SQLITE_OK;
+
+#ifdef SQLITE_AMALGAMATION
+    assert( WAL_CKPT_LOCK==1 );
+#endif
+
+  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
+  if( pRbu && (pRbu->eStage==RBU_STAGE_OAL || pRbu->eStage==RBU_STAGE_MOVE) ){
+    /* Magic number 1 is the WAL_CKPT_LOCK lock. Preventing SQLite from
+    ** taking this lock also prevents any checkpoints from occurring. 
+    ** todo: really, it's not clear why this might occur, as 
+    ** wal_autocheckpoint ought to be turned off.  */
+    if( ofst==WAL_LOCK_CKPT && n==1 ) rc = SQLITE_BUSY;
+  }else{
+    int bCapture = 0;
+    if( n==1 && (flags & SQLITE_SHM_EXCLUSIVE)
+     && pRbu && pRbu->eStage==RBU_STAGE_CAPTURE
+     && (ofst==WAL_LOCK_WRITE || ofst==WAL_LOCK_CKPT || ofst==WAL_LOCK_READ0)
+    ){
+      bCapture = 1;
+    }
+
+    if( bCapture==0 || 0==(flags & SQLITE_SHM_UNLOCK) ){
+      rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
+      if( bCapture && rc==SQLITE_OK ){
+        pRbu->mLock |= (1 << ofst);
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Obtain a pointer to a mapping of a single 32KiB page of the *-shm file.
+*/
+static int rbuVfsShmMap(
+  sqlite3_file *pFile, 
+  int iRegion, 
+  int szRegion, 
+  int isWrite, 
+  void volatile **pp
+){
+  rbu_file *p = (rbu_file*)pFile;
+  int rc = SQLITE_OK;
+  int eStage = (p->pRbu ? p->pRbu->eStage : 0);
+
+  /* If not in RBU_STAGE_OAL, allow this call to pass through. Or, if this
+  ** rbu is in the RBU_STAGE_OAL state, use heap memory for *-shm space 
+  ** instead of a file on disk.  */
+  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
+  if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){
+    if( iRegion<=p->nShm ){
+      int nByte = (iRegion+1) * sizeof(char*);
+      char **apNew = (char**)sqlite3_realloc64(p->apShm, nByte);
+      if( apNew==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(&apNew[p->nShm], 0, sizeof(char*) * (1 + iRegion - p->nShm));
+        p->apShm = apNew;
+        p->nShm = iRegion+1;
+      }
+    }
+
+    if( rc==SQLITE_OK && p->apShm[iRegion]==0 ){
+      char *pNew = (char*)sqlite3_malloc64(szRegion);
+      if( pNew==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memset(pNew, 0, szRegion);
+        p->apShm[iRegion] = pNew;
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      *pp = p->apShm[iRegion];
+    }else{
+      *pp = 0;
+    }
+  }else{
+    assert( p->apShm==0 );
+    rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
+  }
+
+  return rc;
+}
+
+/*
+** Memory barrier.
+*/
+static void rbuVfsShmBarrier(sqlite3_file *pFile){
+  rbu_file *p = (rbu_file *)pFile;
+  p->pReal->pMethods->xShmBarrier(p->pReal);
+}
+
+/*
+** The xShmUnmap method.
+*/
+static int rbuVfsShmUnmap(sqlite3_file *pFile, int delFlag){
+  rbu_file *p = (rbu_file*)pFile;
+  int rc = SQLITE_OK;
+  int eStage = (p->pRbu ? p->pRbu->eStage : 0);
+
+  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
+  if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){
+    /* no-op */
+  }else{
+    /* Release the checkpointer and writer locks */
+    rbuUnlockShm(p);
+    rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
+  }
+  return rc;
+}
+
+/*
+** Given that zWal points to a buffer containing a wal file name passed to 
+** either the xOpen() or xAccess() VFS method, return a pointer to the
+** file-handle opened by the same database connection on the corresponding
+** database file.
+*/
+static rbu_file *rbuFindMaindb(rbu_vfs *pRbuVfs, const char *zWal){
+  rbu_file *pDb;
+  sqlite3_mutex_enter(pRbuVfs->mutex);
+  for(pDb=pRbuVfs->pMain; pDb && pDb->zWal!=zWal; pDb=pDb->pMainNext){}
+  sqlite3_mutex_leave(pRbuVfs->mutex);
+  return pDb;
+}
+
+/* 
+** A main database named zName has just been opened. The following 
+** function returns a pointer to a buffer owned by SQLite that contains
+** the name of the *-wal file this db connection will use. SQLite
+** happens to pass a pointer to this buffer when using xAccess()
+** or xOpen() to operate on the *-wal file.  
+*/
+static const char *rbuMainToWal(const char *zName, int flags){
+  int n = (int)strlen(zName);
+  const char *z = &zName[n];
+  if( flags & SQLITE_OPEN_URI ){
+    int odd = 0;
+    while( 1 ){
+      if( z[0]==0 ){
+        odd = 1 - odd;
+        if( odd && z[1]==0 ) break;
+      }
+      z++;
+    }
+    z += 2;
+  }else{
+    while( *z==0 ) z++;
+  }
+  z += (n + 8 + 1);
+  return z;
+}
+
+/*
+** Open an rbu file handle.
+*/
+static int rbuVfsOpen(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  static sqlite3_io_methods rbuvfs_io_methods = {
+    2,                            /* iVersion */
+    rbuVfsClose,                  /* xClose */
+    rbuVfsRead,                   /* xRead */
+    rbuVfsWrite,                  /* xWrite */
+    rbuVfsTruncate,               /* xTruncate */
+    rbuVfsSync,                   /* xSync */
+    rbuVfsFileSize,               /* xFileSize */
+    rbuVfsLock,                   /* xLock */
+    rbuVfsUnlock,                 /* xUnlock */
+    rbuVfsCheckReservedLock,      /* xCheckReservedLock */
+    rbuVfsFileControl,            /* xFileControl */
+    rbuVfsSectorSize,             /* xSectorSize */
+    rbuVfsDeviceCharacteristics,  /* xDeviceCharacteristics */
+    rbuVfsShmMap,                 /* xShmMap */
+    rbuVfsShmLock,                /* xShmLock */
+    rbuVfsShmBarrier,             /* xShmBarrier */
+    rbuVfsShmUnmap,               /* xShmUnmap */
+    0, 0                          /* xFetch, xUnfetch */
+  };
+  rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs;
+  sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs;
+  rbu_file *pFd = (rbu_file *)pFile;
+  int rc = SQLITE_OK;
+  const char *zOpen = zName;
+  int oflags = flags;
+
+  memset(pFd, 0, sizeof(rbu_file));
+  pFd->pReal = (sqlite3_file*)&pFd[1];
+  pFd->pRbuVfs = pRbuVfs;
+  pFd->openFlags = flags;
+  if( zName ){
+    if( flags & SQLITE_OPEN_MAIN_DB ){
+      /* A main database has just been opened. The following block sets
+      ** (pFd->zWal) to point to a buffer owned by SQLite that contains
+      ** the name of the *-wal file this db connection will use. SQLite
+      ** happens to pass a pointer to this buffer when using xAccess()
+      ** or xOpen() to operate on the *-wal file.  */
+      pFd->zWal = rbuMainToWal(zName, flags);
+    }
+    else if( flags & SQLITE_OPEN_WAL ){
+      rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName);
+      if( pDb ){
+        if( pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
+          /* This call is to open a *-wal file. Intead, open the *-oal. This
+          ** code ensures that the string passed to xOpen() is terminated by a
+          ** pair of '\0' bytes in case the VFS attempts to extract a URI 
+          ** parameter from it.  */
+          const char *zBase = zName;
+          size_t nCopy;
+          char *zCopy;
+          if( rbuIsVacuum(pDb->pRbu) ){
+            zBase = sqlite3_db_filename(pDb->pRbu->dbRbu, "main");
+            zBase = rbuMainToWal(zBase, SQLITE_OPEN_URI);
+          }
+          nCopy = strlen(zBase);
+          zCopy = sqlite3_malloc64(nCopy+2);
+          if( zCopy ){
+            memcpy(zCopy, zBase, nCopy);
+            zCopy[nCopy-3] = 'o';
+            zCopy[nCopy] = '\0';
+            zCopy[nCopy+1] = '\0';
+            zOpen = (const char*)(pFd->zDel = zCopy);
+          }else{
+            rc = SQLITE_NOMEM;
+          }
+          pFd->pRbu = pDb->pRbu;
+        }
+        pDb->pWalFd = pFd;
+      }
+    }
+  }
+
+  if( oflags & SQLITE_OPEN_MAIN_DB 
+   && sqlite3_uri_boolean(zName, "rbu_memory", 0) 
+  ){
+    assert( oflags & SQLITE_OPEN_MAIN_DB );
+    oflags =  SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
+              SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;
+    zOpen = 0;
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = pRealVfs->xOpen(pRealVfs, zOpen, pFd->pReal, oflags, pOutFlags);
+  }
+  if( pFd->pReal->pMethods ){
+    /* The xOpen() operation has succeeded. Set the sqlite3_file.pMethods
+    ** pointer and, if the file is a main database file, link it into the
+    ** mutex protected linked list of all such files.  */
+    pFile->pMethods = &rbuvfs_io_methods;
+    if( flags & SQLITE_OPEN_MAIN_DB ){
+      sqlite3_mutex_enter(pRbuVfs->mutex);
+      pFd->pMainNext = pRbuVfs->pMain;
+      pRbuVfs->pMain = pFd;
+      sqlite3_mutex_leave(pRbuVfs->mutex);
+    }
+  }else{
+    sqlite3_free(pFd->zDel);
+  }
+
+  return rc;
+}
+
+/*
+** Delete the file located at zPath.
+*/
+static int rbuVfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xDelete(pRealVfs, zPath, dirSync);
+}
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+*/
+static int rbuVfsAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs;
+  sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs;
+  int rc;
+
+  rc = pRealVfs->xAccess(pRealVfs, zPath, flags, pResOut);
+
+  /* If this call is to check if a *-wal file associated with an RBU target
+  ** database connection exists, and the RBU update is in RBU_STAGE_OAL,
+  ** the following special handling is activated:
+  **
+  **   a) if the *-wal file does exist, return SQLITE_CANTOPEN. This
+  **      ensures that the RBU extension never tries to update a database
+  **      in wal mode, even if the first page of the database file has
+  **      been damaged. 
+  **
+  **   b) if the *-wal file does not exist, claim that it does anyway,
+  **      causing SQLite to call xOpen() to open it. This call will also
+  **      be intercepted (see the rbuVfsOpen() function) and the *-oal
+  **      file opened instead.
+  */
+  if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){
+    rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath);
+    if( pDb && pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){
+      if( *pResOut ){
+        rc = SQLITE_CANTOPEN;
+      }else{
+        *pResOut = 1;
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Populate buffer zOut with the full canonical pathname corresponding
+** to the pathname in zPath. zOut is guaranteed to point to a buffer
+** of at least (DEVSYM_MAX_PATHNAME+1) bytes.
+*/
+static int rbuVfsFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nOut, 
+  char *zOut
+){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xFullPathname(pRealVfs, zPath, nOut, zOut);
+}
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *rbuVfsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xDlOpen(pRealVfs, zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated 
+** with dynamic libraries.
+*/
+static void rbuVfsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  pRealVfs->xDlError(pRealVfs, nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void (*rbuVfsDlSym(
+  sqlite3_vfs *pVfs, 
+  void *pArg, 
+  const char *zSym
+))(void){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xDlSym(pRealVfs, pArg, zSym);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void rbuVfsDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  pRealVfs->xDlClose(pRealVfs, pHandle);
+}
+#endif /* SQLITE_OMIT_LOAD_EXTENSION */
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of 
+** random data.
+*/
+static int rbuVfsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xRandomness(pRealVfs, nByte, zBufOut);
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds 
+** actually slept.
+*/
+static int rbuVfsSleep(sqlite3_vfs *pVfs, int nMicro){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xSleep(pRealVfs, nMicro);
+}
+
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int rbuVfsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;
+  return pRealVfs->xCurrentTime(pRealVfs, pTimeOut);
+}
+
+/*
+** No-op.
+*/
+static int rbuVfsGetLastError(sqlite3_vfs *pVfs, int a, char *b){
+  return 0;
+}
+
+/*
+** Deregister and destroy an RBU vfs created by an earlier call to
+** sqlite3rbu_create_vfs().
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3rbu_destroy_vfs(const char *zName){
+  sqlite3_vfs *pVfs = sqlite3_vfs_find(zName);
+  if( pVfs && pVfs->xOpen==rbuVfsOpen ){
+    sqlite3_mutex_free(((rbu_vfs*)pVfs)->mutex);
+    sqlite3_vfs_unregister(pVfs);
+    sqlite3_free(pVfs);
+  }
+}
+
+/*
+** Create an RBU VFS named zName that accesses the underlying file-system
+** via existing VFS zParent. The new object is registered as a non-default
+** VFS with SQLite before returning.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3rbu_create_vfs(const char *zName, const char *zParent){
+
+  /* Template for VFS */
+  static sqlite3_vfs vfs_template = {
+    1,                            /* iVersion */
+    0,                            /* szOsFile */
+    0,                            /* mxPathname */
+    0,                            /* pNext */
+    0,                            /* zName */
+    0,                            /* pAppData */
+    rbuVfsOpen,                   /* xOpen */
+    rbuVfsDelete,                 /* xDelete */
+    rbuVfsAccess,                 /* xAccess */
+    rbuVfsFullPathname,           /* xFullPathname */
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    rbuVfsDlOpen,                 /* xDlOpen */
+    rbuVfsDlError,                /* xDlError */
+    rbuVfsDlSym,                  /* xDlSym */
+    rbuVfsDlClose,                /* xDlClose */
+#else
+    0, 0, 0, 0,
+#endif
+
+    rbuVfsRandomness,             /* xRandomness */
+    rbuVfsSleep,                  /* xSleep */
+    rbuVfsCurrentTime,            /* xCurrentTime */
+    rbuVfsGetLastError,           /* xGetLastError */
+    0,                            /* xCurrentTimeInt64 (version 2) */
+    0, 0, 0                       /* Unimplemented version 3 methods */
+  };
+
+  rbu_vfs *pNew = 0;              /* Newly allocated VFS */
+  int rc = SQLITE_OK;
+  size_t nName;
+  size_t nByte;
+
+  nName = strlen(zName);
+  nByte = sizeof(rbu_vfs) + nName + 1;
+  pNew = (rbu_vfs*)sqlite3_malloc64(nByte);
+  if( pNew==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    sqlite3_vfs *pParent;           /* Parent VFS */
+    memset(pNew, 0, nByte);
+    pParent = sqlite3_vfs_find(zParent);
+    if( pParent==0 ){
+      rc = SQLITE_NOTFOUND;
+    }else{
+      char *zSpace;
+      memcpy(&pNew->base, &vfs_template, sizeof(sqlite3_vfs));
+      pNew->base.mxPathname = pParent->mxPathname;
+      pNew->base.szOsFile = sizeof(rbu_file) + pParent->szOsFile;
+      pNew->pRealVfs = pParent;
+      pNew->base.zName = (const char*)(zSpace = (char*)&pNew[1]);
+      memcpy(zSpace, zName, nName);
+
+      /* Allocate the mutex and register the new VFS (not as the default) */
+      pNew->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_RECURSIVE);
+      if( pNew->mutex==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        rc = sqlite3_vfs_register(&pNew->base, 0);
+      }
+    }
+
+    if( rc!=SQLITE_OK ){
+      sqlite3_mutex_free(pNew->mutex);
+      sqlite3_free(pNew);
+    }
+  }
+
+  return rc;
+}
+
+
+/**************************************************************************/
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU) */
+
+/************** End of sqlite3rbu.c ******************************************/
+/************** Begin file dbstat.c ******************************************/
+/*
+** 2010 July 12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains an implementation of the "dbstat" virtual table.
+**
+** The dbstat virtual table is used to extract low-level formatting
+** information from an SQLite database in order to implement the
+** "sqlite3_analyzer" utility.  See the ../tool/spaceanal.tcl script
+** for an example implementation.
+**
+** Additional information is available on the "dbstat.html" page of the
+** official SQLite documentation.
+*/
+
+/* #include "sqliteInt.h"   ** Requires access to internal data structures ** */
+#if (defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)) \
+    && !defined(SQLITE_OMIT_VIRTUALTABLE)
+
+/*
+** Page paths:
+** 
+**   The value of the 'path' column describes the path taken from the 
+**   root-node of the b-tree structure to each page. The value of the 
+**   root-node path is '/'.
+**
+**   The value of the path for the left-most child page of the root of
+**   a b-tree is '/000/'. (Btrees store content ordered from left to right
+**   so the pages to the left have smaller keys than the pages to the right.)
+**   The next to left-most child of the root page is
+**   '/001', and so on, each sibling page identified by a 3-digit hex 
+**   value. The children of the 451st left-most sibling have paths such
+**   as '/1c2/000/, '/1c2/001/' etc.
+**
+**   Overflow pages are specified by appending a '+' character and a 
+**   six-digit hexadecimal value to the path to the cell they are linked
+**   from. For example, the three overflow pages in a chain linked from 
+**   the left-most cell of the 450th child of the root page are identified
+**   by the paths:
+**
+**      '/1c2/000+000000'         // First page in overflow chain
+**      '/1c2/000+000001'         // Second page in overflow chain
+**      '/1c2/000+000002'         // Third page in overflow chain
+**
+**   If the paths are sorted using the BINARY collation sequence, then
+**   the overflow pages associated with a cell will appear earlier in the
+**   sort-order than its child page:
+**
+**      '/1c2/000/'               // Left-most child of 451st child of root
+*/
+#define VTAB_SCHEMA                                                         \
+  "CREATE TABLE xx( "                                                       \
+  "  name       TEXT,             /* Name of table or index */"             \
+  "  path       TEXT,             /* Path to page from root */"             \
+  "  pageno     INTEGER,          /* Page number */"                        \
+  "  pagetype   TEXT,             /* 'internal', 'leaf' or 'overflow' */"   \
+  "  ncell      INTEGER,          /* Cells on page (0 for overflow) */"     \
+  "  payload    INTEGER,          /* Bytes of payload on this page */"      \
+  "  unused     INTEGER,          /* Bytes of unused space on this page */" \
+  "  mx_payload INTEGER,          /* Largest payload size of all cells */"  \
+  "  pgoffset   INTEGER,          /* Offset of page in file */"             \
+  "  pgsize     INTEGER,          /* Size of the page */"                   \
+  "  schema     TEXT HIDDEN       /* Database schema being analyzed */"     \
+  ");"
+
+
+typedef struct StatTable StatTable;
+typedef struct StatCursor StatCursor;
+typedef struct StatPage StatPage;
+typedef struct StatCell StatCell;
+
+struct StatCell {
+  int nLocal;                     /* Bytes of local payload */
+  u32 iChildPg;                   /* Child node (or 0 if this is a leaf) */
+  int nOvfl;                      /* Entries in aOvfl[] */
+  u32 *aOvfl;                     /* Array of overflow page numbers */
+  int nLastOvfl;                  /* Bytes of payload on final overflow page */
+  int iOvfl;                      /* Iterates through aOvfl[] */
+};
+
+struct StatPage {
+  u32 iPgno;
+  DbPage *pPg;
+  int iCell;
+
+  char *zPath;                    /* Path to this page */
+
+  /* Variables populated by statDecodePage(): */
+  u8 flags;                       /* Copy of flags byte */
+  int nCell;                      /* Number of cells on page */
+  int nUnused;                    /* Number of unused bytes on page */
+  StatCell *aCell;                /* Array of parsed cells */
+  u32 iRightChildPg;              /* Right-child page number (or 0) */
+  int nMxPayload;                 /* Largest payload of any cell on this page */
+};
+
+struct StatCursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pStmt;            /* Iterates through set of root pages */
+  int isEof;                      /* After pStmt has returned SQLITE_DONE */
+  int iDb;                        /* Schema used for this query */
+
+  StatPage aPage[32];
+  int iPage;                      /* Current entry in aPage[] */
+
+  /* Values to return. */
+  char *zName;                    /* Value of 'name' column */
+  char *zPath;                    /* Value of 'path' column */
+  u32 iPageno;                    /* Value of 'pageno' column */
+  char *zPagetype;                /* Value of 'pagetype' column */
+  int nCell;                      /* Value of 'ncell' column */
+  int nPayload;                   /* Value of 'payload' column */
+  int nUnused;                    /* Value of 'unused' column */
+  int nMxPayload;                 /* Value of 'mx_payload' column */
+  i64 iOffset;                    /* Value of 'pgOffset' column */
+  int szPage;                     /* Value of 'pgSize' column */
+};
+
+struct StatTable {
+  sqlite3_vtab base;
+  sqlite3 *db;
+  int iDb;                        /* Index of database to analyze */
+};
+
+#ifndef get2byte
+# define get2byte(x)   ((x)[0]<<8 | (x)[1])
+#endif
+
+/*
+** Connect to or create a statvfs virtual table.
+*/
+static int statConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  StatTable *pTab = 0;
+  int rc = SQLITE_OK;
+  int iDb;
+
+  if( argc>=4 ){
+    Token nm;
+    sqlite3TokenInit(&nm, (char*)argv[3]);
+    iDb = sqlite3FindDb(db, &nm);
+    if( iDb<0 ){
+      *pzErr = sqlite3_mprintf("no such database: %s", argv[3]);
+      return SQLITE_ERROR;
+    }
+  }else{
+    iDb = 0;
+  }
+  rc = sqlite3_declare_vtab(db, VTAB_SCHEMA);
+  if( rc==SQLITE_OK ){
+    pTab = (StatTable *)sqlite3_malloc64(sizeof(StatTable));
+    if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
+  }
+
+  assert( rc==SQLITE_OK || pTab==0 );
+  if( rc==SQLITE_OK ){
+    memset(pTab, 0, sizeof(StatTable));
+    pTab->db = db;
+    pTab->iDb = iDb;
+  }
+
+  *ppVtab = (sqlite3_vtab*)pTab;
+  return rc;
+}
+
+/*
+** Disconnect from or destroy a statvfs virtual table.
+*/
+static int statDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** There is no "best-index". This virtual table always does a linear
+** scan.  However, a schema=? constraint should cause this table to
+** operate on a different database schema, so check for it.
+**
+** idxNum is normally 0, but will be 1 if a schema=? constraint exists.
+*/
+static int statBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int i;
+
+  pIdxInfo->estimatedCost = 1.0e6;  /* Initial cost estimate */
+
+  /* Look for a valid schema=? constraint.  If found, change the idxNum to
+  ** 1 and request the value of that constraint be sent to xFilter.  And
+  ** lower the cost estimate to encourage the constrained version to be
+  ** used.
+  */
+  for(i=0; i<pIdxInfo->nConstraint; i++){
+    if( pIdxInfo->aConstraint[i].usable==0 ) continue;
+    if( pIdxInfo->aConstraint[i].op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
+    if( pIdxInfo->aConstraint[i].iColumn!=10 ) continue;
+    pIdxInfo->idxNum = 1;
+    pIdxInfo->estimatedCost = 1.0;
+    pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+    pIdxInfo->aConstraintUsage[i].omit = 1;
+    break;
+  }
+
+
+  /* Records are always returned in ascending order of (name, path). 
+  ** If this will satisfy the client, set the orderByConsumed flag so that 
+  ** SQLite does not do an external sort.
+  */
+  if( ( pIdxInfo->nOrderBy==1
+     && pIdxInfo->aOrderBy[0].iColumn==0
+     && pIdxInfo->aOrderBy[0].desc==0
+     ) ||
+      ( pIdxInfo->nOrderBy==2
+     && pIdxInfo->aOrderBy[0].iColumn==0
+     && pIdxInfo->aOrderBy[0].desc==0
+     && pIdxInfo->aOrderBy[1].iColumn==1
+     && pIdxInfo->aOrderBy[1].desc==0
+     )
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Open a new statvfs cursor.
+*/
+static int statOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  StatTable *pTab = (StatTable *)pVTab;
+  StatCursor *pCsr;
+
+  pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM_BKPT;
+  }else{
+    memset(pCsr, 0, sizeof(StatCursor));
+    pCsr->base.pVtab = pVTab;
+    pCsr->iDb = pTab->iDb;
+  }
+
+  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+static void statClearPage(StatPage *p){
+  int i;
+  if( p->aCell ){
+    for(i=0; i<p->nCell; i++){
+      sqlite3_free(p->aCell[i].aOvfl);
+    }
+    sqlite3_free(p->aCell);
+  }
+  sqlite3PagerUnref(p->pPg);
+  sqlite3_free(p->zPath);
+  memset(p, 0, sizeof(StatPage));
+}
+
+static void statResetCsr(StatCursor *pCsr){
+  int i;
+  sqlite3_reset(pCsr->pStmt);
+  for(i=0; i<ArraySize(pCsr->aPage); i++){
+    statClearPage(&pCsr->aPage[i]);
+  }
+  pCsr->iPage = 0;
+  sqlite3_free(pCsr->zPath);
+  pCsr->zPath = 0;
+  pCsr->isEof = 0;
+}
+
+/*
+** Close a statvfs cursor.
+*/
+static int statClose(sqlite3_vtab_cursor *pCursor){
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  statResetCsr(pCsr);
+  sqlite3_finalize(pCsr->pStmt);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+static void getLocalPayload(
+  int nUsable,                    /* Usable bytes per page */
+  u8 flags,                       /* Page flags */
+  int nTotal,                     /* Total record (payload) size */
+  int *pnLocal                    /* OUT: Bytes stored locally */
+){
+  int nLocal;
+  int nMinLocal;
+  int nMaxLocal;
+ 
+  if( flags==0x0D ){              /* Table leaf node */
+    nMinLocal = (nUsable - 12) * 32 / 255 - 23;
+    nMaxLocal = nUsable - 35;
+  }else{                          /* Index interior and leaf nodes */
+    nMinLocal = (nUsable - 12) * 32 / 255 - 23;
+    nMaxLocal = (nUsable - 12) * 64 / 255 - 23;
+  }
+
+  nLocal = nMinLocal + (nTotal - nMinLocal) % (nUsable - 4);
+  if( nLocal>nMaxLocal ) nLocal = nMinLocal;
+  *pnLocal = nLocal;
+}
+
+static int statDecodePage(Btree *pBt, StatPage *p){
+  int nUnused;
+  int iOff;
+  int nHdr;
+  int isLeaf;
+  int szPage;
+
+  u8 *aData = sqlite3PagerGetData(p->pPg);
+  u8 *aHdr = &aData[p->iPgno==1 ? 100 : 0];
+
+  p->flags = aHdr[0];
+  p->nCell = get2byte(&aHdr[3]);
+  p->nMxPayload = 0;
+
+  isLeaf = (p->flags==0x0A || p->flags==0x0D);
+  nHdr = 12 - isLeaf*4 + (p->iPgno==1)*100;
+
+  nUnused = get2byte(&aHdr[5]) - nHdr - 2*p->nCell;
+  nUnused += (int)aHdr[7];
+  iOff = get2byte(&aHdr[1]);
+  while( iOff ){
+    nUnused += get2byte(&aData[iOff+2]);
+    iOff = get2byte(&aData[iOff]);
+  }
+  p->nUnused = nUnused;
+  p->iRightChildPg = isLeaf ? 0 : sqlite3Get4byte(&aHdr[8]);
+  szPage = sqlite3BtreeGetPageSize(pBt);
+
+  if( p->nCell ){
+    int i;                        /* Used to iterate through cells */
+    int nUsable;                  /* Usable bytes per page */
+
+    sqlite3BtreeEnter(pBt);
+    nUsable = szPage - sqlite3BtreeGetReserveNoMutex(pBt);
+    sqlite3BtreeLeave(pBt);
+    p->aCell = sqlite3_malloc64((p->nCell+1) * sizeof(StatCell));
+    if( p->aCell==0 ) return SQLITE_NOMEM_BKPT;
+    memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell));
+
+    for(i=0; i<p->nCell; i++){
+      StatCell *pCell = &p->aCell[i];
+
+      iOff = get2byte(&aData[nHdr+i*2]);
+      if( !isLeaf ){
+        pCell->iChildPg = sqlite3Get4byte(&aData[iOff]);
+        iOff += 4;
+      }
+      if( p->flags==0x05 ){
+        /* A table interior node. nPayload==0. */
+      }else{
+        u32 nPayload;             /* Bytes of payload total (local+overflow) */
+        int nLocal;               /* Bytes of payload stored locally */
+        iOff += getVarint32(&aData[iOff], nPayload);
+        if( p->flags==0x0D ){
+          u64 dummy;
+          iOff += sqlite3GetVarint(&aData[iOff], &dummy);
+        }
+        if( nPayload>(u32)p->nMxPayload ) p->nMxPayload = nPayload;
+        getLocalPayload(nUsable, p->flags, nPayload, &nLocal);
+        pCell->nLocal = nLocal;
+        assert( nLocal>=0 );
+        assert( nPayload>=(u32)nLocal );
+        assert( nLocal<=(nUsable-35) );
+        if( nPayload>(u32)nLocal ){
+          int j;
+          int nOvfl = ((nPayload - nLocal) + nUsable-4 - 1) / (nUsable - 4);
+          pCell->nLastOvfl = (nPayload-nLocal) - (nOvfl-1) * (nUsable-4);
+          pCell->nOvfl = nOvfl;
+          pCell->aOvfl = sqlite3_malloc64(sizeof(u32)*nOvfl);
+          if( pCell->aOvfl==0 ) return SQLITE_NOMEM_BKPT;
+          pCell->aOvfl[0] = sqlite3Get4byte(&aData[iOff+nLocal]);
+          for(j=1; j<nOvfl; j++){
+            int rc;
+            u32 iPrev = pCell->aOvfl[j-1];
+            DbPage *pPg = 0;
+            rc = sqlite3PagerGet(sqlite3BtreePager(pBt), iPrev, &pPg, 0);
+            if( rc!=SQLITE_OK ){
+              assert( pPg==0 );
+              return rc;
+            } 
+            pCell->aOvfl[j] = sqlite3Get4byte(sqlite3PagerGetData(pPg));
+            sqlite3PagerUnref(pPg);
+          }
+        }
+      }
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on
+** the current value of pCsr->iPageno.
+*/
+static void statSizeAndOffset(StatCursor *pCsr){
+  StatTable *pTab = (StatTable *)((sqlite3_vtab_cursor *)pCsr)->pVtab;
+  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
+  Pager *pPager = sqlite3BtreePager(pBt);
+  sqlite3_file *fd;
+  sqlite3_int64 x[2];
+
+  /* The default page size and offset */
+  pCsr->szPage = sqlite3BtreeGetPageSize(pBt);
+  pCsr->iOffset = (i64)pCsr->szPage * (pCsr->iPageno - 1);
+
+  /* If connected to a ZIPVFS backend, override the page size and
+  ** offset with actual values obtained from ZIPVFS.
+  */
+  fd = sqlite3PagerFile(pPager);
+  x[0] = pCsr->iPageno;
+  if( fd->pMethods!=0 && sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){
+    pCsr->iOffset = x[0];
+    pCsr->szPage = (int)x[1];
+  }
+}
+
+/*
+** Move a statvfs cursor to the next entry in the file.
+*/
+static int statNext(sqlite3_vtab_cursor *pCursor){
+  int rc;
+  int nPayload;
+  char *z;
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  StatTable *pTab = (StatTable *)pCursor->pVtab;
+  Btree *pBt = pTab->db->aDb[pCsr->iDb].pBt;
+  Pager *pPager = sqlite3BtreePager(pBt);
+
+  sqlite3_free(pCsr->zPath);
+  pCsr->zPath = 0;
+
+statNextRestart:
+  if( pCsr->aPage[0].pPg==0 ){
+    rc = sqlite3_step(pCsr->pStmt);
+    if( rc==SQLITE_ROW ){
+      int nPage;
+      u32 iRoot = (u32)sqlite3_column_int64(pCsr->pStmt, 1);
+      sqlite3PagerPagecount(pPager, &nPage);
+      if( nPage==0 ){
+        pCsr->isEof = 1;
+        return sqlite3_reset(pCsr->pStmt);
+      }
+      rc = sqlite3PagerGet(pPager, iRoot, &pCsr->aPage[0].pPg, 0);
+      pCsr->aPage[0].iPgno = iRoot;
+      pCsr->aPage[0].iCell = 0;
+      pCsr->aPage[0].zPath = z = sqlite3_mprintf("/");
+      pCsr->iPage = 0;
+      if( z==0 ) rc = SQLITE_NOMEM_BKPT;
+    }else{
+      pCsr->isEof = 1;
+      return sqlite3_reset(pCsr->pStmt);
+    }
+  }else{
+
+    /* Page p itself has already been visited. */
+    StatPage *p = &pCsr->aPage[pCsr->iPage];
+
+    while( p->iCell<p->nCell ){
+      StatCell *pCell = &p->aCell[p->iCell];
+      if( pCell->iOvfl<pCell->nOvfl ){
+        int nUsable;
+        sqlite3BtreeEnter(pBt);
+        nUsable = sqlite3BtreeGetPageSize(pBt) - 
+                        sqlite3BtreeGetReserveNoMutex(pBt);
+        sqlite3BtreeLeave(pBt);
+        pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);
+        pCsr->iPageno = pCell->aOvfl[pCell->iOvfl];
+        pCsr->zPagetype = "overflow";
+        pCsr->nCell = 0;
+        pCsr->nMxPayload = 0;
+        pCsr->zPath = z = sqlite3_mprintf(
+            "%s%.3x+%.6x", p->zPath, p->iCell, pCell->iOvfl
+        );
+        if( pCell->iOvfl<pCell->nOvfl-1 ){
+          pCsr->nUnused = 0;
+          pCsr->nPayload = nUsable - 4;
+        }else{
+          pCsr->nPayload = pCell->nLastOvfl;
+          pCsr->nUnused = nUsable - 4 - pCsr->nPayload;
+        }
+        pCell->iOvfl++;
+        statSizeAndOffset(pCsr);
+        return z==0 ? SQLITE_NOMEM_BKPT : SQLITE_OK;
+      }
+      if( p->iRightChildPg ) break;
+      p->iCell++;
+    }
+
+    if( !p->iRightChildPg || p->iCell>p->nCell ){
+      statClearPage(p);
+      if( pCsr->iPage==0 ) return statNext(pCursor);
+      pCsr->iPage--;
+      goto statNextRestart; /* Tail recursion */
+    }
+    pCsr->iPage++;
+    assert( p==&pCsr->aPage[pCsr->iPage-1] );
+
+    if( p->iCell==p->nCell ){
+      p[1].iPgno = p->iRightChildPg;
+    }else{
+      p[1].iPgno = p->aCell[p->iCell].iChildPg;
+    }
+    rc = sqlite3PagerGet(pPager, p[1].iPgno, &p[1].pPg, 0);
+    p[1].iCell = 0;
+    p[1].zPath = z = sqlite3_mprintf("%s%.3x/", p->zPath, p->iCell);
+    p->iCell++;
+    if( z==0 ) rc = SQLITE_NOMEM_BKPT;
+  }
+
+
+  /* Populate the StatCursor fields with the values to be returned
+  ** by the xColumn() and xRowid() methods.
+  */
+  if( rc==SQLITE_OK ){
+    int i;
+    StatPage *p = &pCsr->aPage[pCsr->iPage];
+    pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);
+    pCsr->iPageno = p->iPgno;
+
+    rc = statDecodePage(pBt, p);
+    if( rc==SQLITE_OK ){
+      statSizeAndOffset(pCsr);
+
+      switch( p->flags ){
+        case 0x05:             /* table internal */
+        case 0x02:             /* index internal */
+          pCsr->zPagetype = "internal";
+          break;
+        case 0x0D:             /* table leaf */
+        case 0x0A:             /* index leaf */
+          pCsr->zPagetype = "leaf";
+          break;
+        default:
+          pCsr->zPagetype = "corrupted";
+          break;
+      }
+      pCsr->nCell = p->nCell;
+      pCsr->nUnused = p->nUnused;
+      pCsr->nMxPayload = p->nMxPayload;
+      pCsr->zPath = z = sqlite3_mprintf("%s", p->zPath);
+      if( z==0 ) rc = SQLITE_NOMEM_BKPT;
+      nPayload = 0;
+      for(i=0; i<p->nCell; i++){
+        nPayload += p->aCell[i].nLocal;
+      }
+      pCsr->nPayload = nPayload;
+    }
+  }
+
+  return rc;
+}
+
+static int statEof(sqlite3_vtab_cursor *pCursor){
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  return pCsr->isEof;
+}
+
+static int statFilter(
+  sqlite3_vtab_cursor *pCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  StatTable *pTab = (StatTable*)(pCursor->pVtab);
+  char *zSql;
+  int rc = SQLITE_OK;
+  char *zMaster;
+
+  if( idxNum==1 ){
+    const char *zDbase = (const char*)sqlite3_value_text(argv[0]);
+    pCsr->iDb = sqlite3FindDbName(pTab->db, zDbase);
+    if( pCsr->iDb<0 ){
+      sqlite3_free(pCursor->pVtab->zErrMsg);
+      pCursor->pVtab->zErrMsg = sqlite3_mprintf("no such schema: %s", zDbase);
+      return pCursor->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM_BKPT;
+    }
+  }else{
+    pCsr->iDb = pTab->iDb;
+  }
+  statResetCsr(pCsr);
+  sqlite3_finalize(pCsr->pStmt);
+  pCsr->pStmt = 0;
+  zMaster = pCsr->iDb==1 ? "sqlite_temp_master" : "sqlite_master";
+  zSql = sqlite3_mprintf(
+      "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
+      "  UNION ALL  "
+      "SELECT name, rootpage, type"
+      "  FROM \"%w\".%s WHERE rootpage!=0"
+      "  ORDER BY name", pTab->db->aDb[pCsr->iDb].zName, zMaster);
+  if( zSql==0 ){
+    return SQLITE_NOMEM_BKPT;
+  }else{
+    rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
+    sqlite3_free(zSql);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = statNext(pCursor);
+  }
+  return rc;
+}
+
+static int statColumn(
+  sqlite3_vtab_cursor *pCursor, 
+  sqlite3_context *ctx, 
+  int i
+){
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  switch( i ){
+    case 0:            /* name */
+      sqlite3_result_text(ctx, pCsr->zName, -1, SQLITE_TRANSIENT);
+      break;
+    case 1:            /* path */
+      sqlite3_result_text(ctx, pCsr->zPath, -1, SQLITE_TRANSIENT);
+      break;
+    case 2:            /* pageno */
+      sqlite3_result_int64(ctx, pCsr->iPageno);
+      break;
+    case 3:            /* pagetype */
+      sqlite3_result_text(ctx, pCsr->zPagetype, -1, SQLITE_STATIC);
+      break;
+    case 4:            /* ncell */
+      sqlite3_result_int(ctx, pCsr->nCell);
+      break;
+    case 5:            /* payload */
+      sqlite3_result_int(ctx, pCsr->nPayload);
+      break;
+    case 6:            /* unused */
+      sqlite3_result_int(ctx, pCsr->nUnused);
+      break;
+    case 7:            /* mx_payload */
+      sqlite3_result_int(ctx, pCsr->nMxPayload);
+      break;
+    case 8:            /* pgoffset */
+      sqlite3_result_int64(ctx, pCsr->iOffset);
+      break;
+    case 9:            /* pgsize */
+      sqlite3_result_int(ctx, pCsr->szPage);
+      break;
+    default: {          /* schema */
+      sqlite3 *db = sqlite3_context_db_handle(ctx);
+      int iDb = pCsr->iDb;
+      sqlite3_result_text(ctx, db->aDb[iDb].zName, -1, SQLITE_STATIC);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
+  StatCursor *pCsr = (StatCursor *)pCursor;
+  *pRowid = pCsr->iPageno;
+  return SQLITE_OK;
+}
+
+/*
+** Invoke this routine to register the "dbstat" virtual table module
+*/
+SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3 *db){
+  static sqlite3_module dbstat_module = {
+    0,                            /* iVersion */
+    statConnect,                  /* xCreate */
+    statConnect,                  /* xConnect */
+    statBestIndex,                /* xBestIndex */
+    statDisconnect,               /* xDisconnect */
+    statDisconnect,               /* xDestroy */
+    statOpen,                     /* xOpen - open a cursor */
+    statClose,                    /* xClose - close a cursor */
+    statFilter,                   /* xFilter - configure scan constraints */
+    statNext,                     /* xNext - advance a cursor */
+    statEof,                      /* xEof - check for end of scan */
+    statColumn,                   /* xColumn - read data */
+    statRowid,                    /* xRowid - read data */
+    0,                            /* xUpdate */
+    0,                            /* xBegin */
+    0,                            /* xSync */
+    0,                            /* xCommit */
+    0,                            /* xRollback */
+    0,                            /* xFindMethod */
+    0,                            /* xRename */
+  };
+  return sqlite3_create_module(db, "dbstat", &dbstat_module, 0);
+}
+#elif defined(SQLITE_ENABLE_DBSTAT_VTAB)
+SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3 *db){ return SQLITE_OK; }
+#endif /* SQLITE_ENABLE_DBSTAT_VTAB */
+
+/************** End of dbstat.c **********************************************/
+/************** Begin file sqlite3session.c **********************************/
+
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+/* #include "sqlite3session.h" */
+/* #include <assert.h> */
+/* #include <string.h> */
+
+#ifndef SQLITE_AMALGAMATION
+/* # include "sqliteInt.h" */
+/* # include "vdbeInt.h" */
+#endif
+
+typedef struct SessionTable SessionTable;
+typedef struct SessionChange SessionChange;
+typedef struct SessionBuffer SessionBuffer;
+typedef struct SessionInput SessionInput;
+
+/*
+** Minimum chunk size used by streaming versions of functions.
+*/
+#ifndef SESSIONS_STRM_CHUNK_SIZE
+# ifdef SQLITE_TEST
+#   define SESSIONS_STRM_CHUNK_SIZE 64
+# else
+#   define SESSIONS_STRM_CHUNK_SIZE 1024
+# endif
+#endif
+
+typedef struct SessionHook SessionHook;
+struct SessionHook {
+  void *pCtx;
+  int (*xOld)(void*,int,sqlite3_value**);
+  int (*xNew)(void*,int,sqlite3_value**);
+  int (*xCount)(void*);
+  int (*xDepth)(void*);
+};
+
+/*
+** Session handle structure.
+*/
+struct sqlite3_session {
+  sqlite3 *db;                    /* Database handle session is attached to */
+  char *zDb;                      /* Name of database session is attached to */
+  int bEnable;                    /* True if currently recording */
+  int bIndirect;                  /* True if all changes are indirect */
+  int bAutoAttach;                /* True to auto-attach tables */
+  int rc;                         /* Non-zero if an error has occurred */
+  void *pFilterCtx;               /* First argument to pass to xTableFilter */
+  int (*xTableFilter)(void *pCtx, const char *zTab);
+  sqlite3_session *pNext;         /* Next session object on same db. */
+  SessionTable *pTable;           /* List of attached tables */
+  SessionHook hook;               /* APIs to grab new and old data with */
+};
+
+/*
+** Instances of this structure are used to build strings or binary records.
+*/
+struct SessionBuffer {
+  u8 *aBuf;                       /* Pointer to changeset buffer */
+  int nBuf;                       /* Size of buffer aBuf */
+  int nAlloc;                     /* Size of allocation containing aBuf */
+};
+
+/*
+** An object of this type is used internally as an abstraction for 
+** input data. Input data may be supplied either as a single large buffer
+** (e.g. sqlite3changeset_start()) or using a stream function (e.g.
+**  sqlite3changeset_start_strm()).
+*/
+struct SessionInput {
+  int bNoDiscard;                 /* If true, discard no data */
+  int iCurrent;                   /* Offset in aData[] of current change */
+  int iNext;                      /* Offset in aData[] of next change */
+  u8 *aData;                      /* Pointer to buffer containing changeset */
+  int nData;                      /* Number of bytes in aData */
+
+  SessionBuffer buf;              /* Current read buffer */
+  int (*xInput)(void*, void*, int*);        /* Input stream call (or NULL) */
+  void *pIn;                                /* First argument to xInput */
+  int bEof;                       /* Set to true after xInput finished */
+};
+
+/*
+** Structure for changeset iterators.
+*/
+struct sqlite3_changeset_iter {
+  SessionInput in;                /* Input buffer or stream */
+  SessionBuffer tblhdr;           /* Buffer to hold apValue/zTab/abPK/ */
+  int bPatchset;                  /* True if this is a patchset */
+  int rc;                         /* Iterator error code */
+  sqlite3_stmt *pConflict;        /* Points to conflicting row, if any */
+  char *zTab;                     /* Current table */
+  int nCol;                       /* Number of columns in zTab */
+  int op;                         /* Current operation */
+  int bIndirect;                  /* True if current change was indirect */
+  u8 *abPK;                       /* Primary key array */
+  sqlite3_value **apValue;        /* old.* and new.* values */
+};
+
+/*
+** Each session object maintains a set of the following structures, one
+** for each table the session object is monitoring. The structures are
+** stored in a linked list starting at sqlite3_session.pTable.
+**
+** The keys of the SessionTable.aChange[] hash table are all rows that have
+** been modified in any way since the session object was attached to the
+** table.
+**
+** The data associated with each hash-table entry is a structure containing
+** a subset of the initial values that the modified row contained at the
+** start of the session. Or no initial values if the row was inserted.
+*/
+struct SessionTable {
+  SessionTable *pNext;
+  char *zName;                    /* Local name of table */
+  int nCol;                       /* Number of columns in table zName */
+  const char **azCol;             /* Column names */
+  u8 *abPK;                       /* Array of primary key flags */
+  int nEntry;                     /* Total number of entries in hash table */
+  int nChange;                    /* Size of apChange[] array */
+  SessionChange **apChange;       /* Hash table buckets */
+};
+
+/* 
+** RECORD FORMAT:
+**
+** The following record format is similar to (but not compatible with) that 
+** used in SQLite database files. This format is used as part of the 
+** change-set binary format, and so must be architecture independent.
+**
+** Unlike the SQLite database record format, each field is self-contained -
+** there is no separation of header and data. Each field begins with a
+** single byte describing its type, as follows:
+**
+**       0x00: Undefined value.
+**       0x01: Integer value.
+**       0x02: Real value.
+**       0x03: Text value.
+**       0x04: Blob value.
+**       0x05: SQL NULL value.
+**
+** Note that the above match the definitions of SQLITE_INTEGER, SQLITE_TEXT
+** and so on in sqlite3.h. For undefined and NULL values, the field consists
+** only of the single type byte. For other types of values, the type byte
+** is followed by:
+**
+**   Text values:
+**     A varint containing the number of bytes in the value (encoded using
+**     UTF-8). Followed by a buffer containing the UTF-8 representation
+**     of the text value. There is no nul terminator.
+**
+**   Blob values:
+**     A varint containing the number of bytes in the value, followed by
+**     a buffer containing the value itself.
+**
+**   Integer values:
+**     An 8-byte big-endian integer value.
+**
+**   Real values:
+**     An 8-byte big-endian IEEE 754-2008 real value.
+**
+** Varint values are encoded in the same way as varints in the SQLite 
+** record format.
+**
+** CHANGESET FORMAT:
+**
+** A changeset is a collection of DELETE, UPDATE and INSERT operations on
+** one or more tables. Operations on a single table are grouped together,
+** but may occur in any order (i.e. deletes, updates and inserts are all
+** mixed together).
+**
+** Each group of changes begins with a table header:
+**
+**   1 byte: Constant 0x54 (capital 'T')
+**   Varint: Number of columns in the table.
+**   nCol bytes: 0x01 for PK columns, 0x00 otherwise.
+**   N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.
+**
+** Followed by one or more changes to the table.
+**
+**   1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09).
+**   1 byte: The "indirect-change" flag.
+**   old.* record: (delete and update only)
+**   new.* record: (insert and update only)
+**
+** The "old.*" and "new.*" records, if present, are N field records in the
+** format described above under "RECORD FORMAT", where N is the number of
+** columns in the table. The i'th field of each record is associated with
+** the i'th column of the table, counting from left to right in the order
+** in which columns were declared in the CREATE TABLE statement.
+**
+** The new.* record that is part of each INSERT change contains the values
+** that make up the new row. Similarly, the old.* record that is part of each
+** DELETE change contains the values that made up the row that was deleted 
+** from the database. In the changeset format, the records that are part
+** of INSERT or DELETE changes never contain any undefined (type byte 0x00)
+** fields.
+**
+** Within the old.* record associated with an UPDATE change, all fields
+** associated with table columns that are not PRIMARY KEY columns and are
+** not modified by the UPDATE change are set to "undefined". Other fields
+** are set to the values that made up the row before the UPDATE that the
+** change records took place. Within the new.* record, fields associated 
+** with table columns modified by the UPDATE change contain the new 
+** values. Fields associated with table columns that are not modified
+** are set to "undefined".
+**
+** PATCHSET FORMAT:
+**
+** A patchset is also a collection of changes. It is similar to a changeset,
+** but leaves undefined those fields that are not useful if no conflict
+** resolution is required when applying the changeset.
+**
+** Each group of changes begins with a table header:
+**
+**   1 byte: Constant 0x50 (capital 'P')
+**   Varint: Number of columns in the table.
+**   nCol bytes: 0x01 for PK columns, 0x00 otherwise.
+**   N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.
+**
+** Followed by one or more changes to the table.
+**
+**   1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09).
+**   1 byte: The "indirect-change" flag.
+**   single record: (PK fields for DELETE, PK and modified fields for UPDATE,
+**                   full record for INSERT).
+**
+** As in the changeset format, each field of the single record that is part
+** of a patchset change is associated with the correspondingly positioned
+** table column, counting from left to right within the CREATE TABLE 
+** statement.
+**
+** For a DELETE change, all fields within the record except those associated
+** with PRIMARY KEY columns are set to "undefined". The PRIMARY KEY fields
+** contain the values identifying the row to delete.
+**
+** For an UPDATE change, all fields except those associated with PRIMARY KEY
+** columns and columns that are modified by the UPDATE are set to "undefined".
+** PRIMARY KEY fields contain the values identifying the table row to update,
+** and fields associated with modified columns contain the new column values.
+**
+** The records associated with INSERT changes are in the same format as for
+** changesets. It is not possible for a record associated with an INSERT
+** change to contain a field set to "undefined".
+*/
+
+/*
+** For each row modified during a session, there exists a single instance of
+** this structure stored in a SessionTable.aChange[] hash table.
+*/
+struct SessionChange {
+  int op;                         /* One of UPDATE, DELETE, INSERT */
+  int bIndirect;                  /* True if this change is "indirect" */
+  int nRecord;                    /* Number of bytes in buffer aRecord[] */
+  u8 *aRecord;                    /* Buffer containing old.* record */
+  SessionChange *pNext;           /* For hash-table collisions */
+};
+
+/*
+** Write a varint with value iVal into the buffer at aBuf. Return the 
+** number of bytes written.
+*/
+static int sessionVarintPut(u8 *aBuf, int iVal){
+  return putVarint32(aBuf, iVal);
+}
+
+/*
+** Return the number of bytes required to store value iVal as a varint.
+*/
+static int sessionVarintLen(int iVal){
+  return sqlite3VarintLen(iVal);
+}
+
+/*
+** Read a varint value from aBuf[] into *piVal. Return the number of 
+** bytes read.
+*/
+static int sessionVarintGet(u8 *aBuf, int *piVal){
+  return getVarint32(aBuf, *piVal);
+}
+
+/* Load an unaligned and unsigned 32-bit integer */
+#define SESSION_UINT32(x) (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
+
+/*
+** Read a 64-bit big-endian integer value from buffer aRec[]. Return
+** the value read.
+*/
+static sqlite3_int64 sessionGetI64(u8 *aRec){
+  u64 x = SESSION_UINT32(aRec);
+  u32 y = SESSION_UINT32(aRec+4);
+  x = (x<<32) + y;
+  return (sqlite3_int64)x;
+}
+
+/*
+** Write a 64-bit big-endian integer value to the buffer aBuf[].
+*/
+static void sessionPutI64(u8 *aBuf, sqlite3_int64 i){
+  aBuf[0] = (i>>56) & 0xFF;
+  aBuf[1] = (i>>48) & 0xFF;
+  aBuf[2] = (i>>40) & 0xFF;
+  aBuf[3] = (i>>32) & 0xFF;
+  aBuf[4] = (i>>24) & 0xFF;
+  aBuf[5] = (i>>16) & 0xFF;
+  aBuf[6] = (i>> 8) & 0xFF;
+  aBuf[7] = (i>> 0) & 0xFF;
+}
+
+/*
+** This function is used to serialize the contents of value pValue (see
+** comment titled "RECORD FORMAT" above).
+**
+** If it is non-NULL, the serialized form of the value is written to 
+** buffer aBuf. *pnWrite is set to the number of bytes written before
+** returning. Or, if aBuf is NULL, the only thing this function does is
+** set *pnWrite.
+**
+** If no error occurs, SQLITE_OK is returned. Or, if an OOM error occurs
+** within a call to sqlite3_value_text() (may fail if the db is utf-16)) 
+** SQLITE_NOMEM is returned.
+*/
+static int sessionSerializeValue(
+  u8 *aBuf,                       /* If non-NULL, write serialized value here */
+  sqlite3_value *pValue,          /* Value to serialize */
+  int *pnWrite                    /* IN/OUT: Increment by bytes written */
+){
+  int nByte;                      /* Size of serialized value in bytes */
+
+  if( pValue ){
+    int eType;                    /* Value type (SQLITE_NULL, TEXT etc.) */
+  
+    eType = sqlite3_value_type(pValue);
+    if( aBuf ) aBuf[0] = eType;
+  
+    switch( eType ){
+      case SQLITE_NULL: 
+        nByte = 1;
+        break;
+  
+      case SQLITE_INTEGER: 
+      case SQLITE_FLOAT:
+        if( aBuf ){
+          /* TODO: SQLite does something special to deal with mixed-endian
+          ** floating point values (e.g. ARM7). This code probably should
+          ** too.  */
+          u64 i;
+          if( eType==SQLITE_INTEGER ){
+            i = (u64)sqlite3_value_int64(pValue);
+          }else{
+            double r;
+            assert( sizeof(double)==8 && sizeof(u64)==8 );
+            r = sqlite3_value_double(pValue);
+            memcpy(&i, &r, 8);
+          }
+          sessionPutI64(&aBuf[1], i);
+        }
+        nByte = 9; 
+        break;
+  
+      default: {
+        u8 *z;
+        int n;
+        int nVarint;
+  
+        assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
+        if( eType==SQLITE_TEXT ){
+          z = (u8 *)sqlite3_value_text(pValue);
+        }else{
+          z = (u8 *)sqlite3_value_blob(pValue);
+        }
+        n = sqlite3_value_bytes(pValue);
+        if( z==0 && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM;
+        nVarint = sessionVarintLen(n);
+  
+        if( aBuf ){
+          sessionVarintPut(&aBuf[1], n);
+          memcpy(&aBuf[nVarint + 1], eType==SQLITE_TEXT ? 
+              sqlite3_value_text(pValue) : sqlite3_value_blob(pValue), n
+          );
+        }
+  
+        nByte = 1 + nVarint + n;
+        break;
+      }
+    }
+  }else{
+    nByte = 1;
+    if( aBuf ) aBuf[0] = '\0';
+  }
+
+  if( pnWrite ) *pnWrite += nByte;
+  return SQLITE_OK;
+}
+
+
+/*
+** This macro is used to calculate hash key values for data structures. In
+** order to use this macro, the entire data structure must be represented
+** as a series of unsigned integers. In order to calculate a hash-key value
+** for a data structure represented as three such integers, the macro may
+** then be used as follows:
+**
+**    int hash_key_value;
+**    hash_key_value = HASH_APPEND(0, <value 1>);
+**    hash_key_value = HASH_APPEND(hash_key_value, <value 2>);
+**    hash_key_value = HASH_APPEND(hash_key_value, <value 3>);
+**
+** In practice, the data structures this macro is used for are the primary
+** key values of modified rows.
+*/
+#define HASH_APPEND(hash, add) ((hash) << 3) ^ (hash) ^ (unsigned int)(add)
+
+/*
+** Append the hash of the 64-bit integer passed as the second argument to the
+** hash-key value passed as the first. Return the new hash-key value.
+*/
+static unsigned int sessionHashAppendI64(unsigned int h, i64 i){
+  h = HASH_APPEND(h, i & 0xFFFFFFFF);
+  return HASH_APPEND(h, (i>>32)&0xFFFFFFFF);
+}
+
+/*
+** Append the hash of the blob passed via the second and third arguments to 
+** the hash-key value passed as the first. Return the new hash-key value.
+*/
+static unsigned int sessionHashAppendBlob(unsigned int h, int n, const u8 *z){
+  int i;
+  for(i=0; i<n; i++) h = HASH_APPEND(h, z[i]);
+  return h;
+}
+
+/*
+** Append the hash of the data type passed as the second argument to the
+** hash-key value passed as the first. Return the new hash-key value.
+*/
+static unsigned int sessionHashAppendType(unsigned int h, int eType){
+  return HASH_APPEND(h, eType);
+}
+
+/*
+** This function may only be called from within a pre-update callback.
+** It calculates a hash based on the primary key values of the old.* or 
+** new.* row currently available and, assuming no error occurs, writes it to
+** *piHash before returning. If the primary key contains one or more NULL
+** values, *pbNullPK is set to true before returning.
+**
+** If an error occurs, an SQLite error code is returned and the final values
+** of *piHash asn *pbNullPK are undefined. Otherwise, SQLITE_OK is returned
+** and the output variables are set as described above.
+*/
+static int sessionPreupdateHash(
+  sqlite3_session *pSession,      /* Session object that owns pTab */
+  SessionTable *pTab,             /* Session table handle */
+  int bNew,                       /* True to hash the new.* PK */
+  int *piHash,                    /* OUT: Hash value */
+  int *pbNullPK                   /* OUT: True if there are NULL values in PK */
+){
+  unsigned int h = 0;             /* Hash value to return */
+  int i;                          /* Used to iterate through columns */
+
+  assert( *pbNullPK==0 );
+  assert( pTab->nCol==pSession->hook.xCount(pSession->hook.pCtx) );
+  for(i=0; i<pTab->nCol; i++){
+    if( pTab->abPK[i] ){
+      int rc;
+      int eType;
+      sqlite3_value *pVal;
+
+      if( bNew ){
+        rc = pSession->hook.xNew(pSession->hook.pCtx, i, &pVal);
+      }else{
+        rc = pSession->hook.xOld(pSession->hook.pCtx, i, &pVal);
+      }
+      if( rc!=SQLITE_OK ) return rc;
+
+      eType = sqlite3_value_type(pVal);
+      h = sessionHashAppendType(h, eType);
+      if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+        i64 iVal;
+        if( eType==SQLITE_INTEGER ){
+          iVal = sqlite3_value_int64(pVal);
+        }else{
+          double rVal = sqlite3_value_double(pVal);
+          assert( sizeof(iVal)==8 && sizeof(rVal)==8 );
+          memcpy(&iVal, &rVal, 8);
+        }
+        h = sessionHashAppendI64(h, iVal);
+      }else if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
+        const u8 *z;
+        int n;
+        if( eType==SQLITE_TEXT ){
+          z = (const u8 *)sqlite3_value_text(pVal);
+        }else{
+          z = (const u8 *)sqlite3_value_blob(pVal);
+        }
+        n = sqlite3_value_bytes(pVal);
+        if( !z && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM;
+        h = sessionHashAppendBlob(h, n, z);
+      }else{
+        assert( eType==SQLITE_NULL );
+        *pbNullPK = 1;
+      }
+    }
+  }
+
+  *piHash = (h % pTab->nChange);
+  return SQLITE_OK;
+}
+
+/*
+** The buffer that the argument points to contains a serialized SQL value.
+** Return the number of bytes of space occupied by the value (including
+** the type byte).
+*/
+static int sessionSerialLen(u8 *a){
+  int e = *a;
+  int n;
+  if( e==0 ) return 1;
+  if( e==SQLITE_NULL ) return 1;
+  if( e==SQLITE_INTEGER || e==SQLITE_FLOAT ) return 9;
+  return sessionVarintGet(&a[1], &n) + 1 + n;
+}
+
+/*
+** Based on the primary key values stored in change aRecord, calculate a
+** hash key. Assume the has table has nBucket buckets. The hash keys
+** calculated by this function are compatible with those calculated by
+** sessionPreupdateHash().
+**
+** The bPkOnly argument is non-zero if the record at aRecord[] is from
+** a patchset DELETE. In this case the non-PK fields are omitted entirely.
+*/
+static unsigned int sessionChangeHash(
+  SessionTable *pTab,             /* Table handle */
+  int bPkOnly,                    /* Record consists of PK fields only */
+  u8 *aRecord,                    /* Change record */
+  int nBucket                     /* Assume this many buckets in hash table */
+){
+  unsigned int h = 0;             /* Value to return */
+  int i;                          /* Used to iterate through columns */
+  u8 *a = aRecord;                /* Used to iterate through change record */
+
+  for(i=0; i<pTab->nCol; i++){
+    int eType = *a;
+    int isPK = pTab->abPK[i];
+    if( bPkOnly && isPK==0 ) continue;
+
+    /* It is not possible for eType to be SQLITE_NULL here. The session 
+    ** module does not record changes for rows with NULL values stored in
+    ** primary key columns. */
+    assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT 
+         || eType==SQLITE_TEXT || eType==SQLITE_BLOB 
+         || eType==SQLITE_NULL || eType==0 
+    );
+    assert( !isPK || (eType!=0 && eType!=SQLITE_NULL) );
+
+    if( isPK ){
+      a++;
+      h = sessionHashAppendType(h, eType);
+      if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+        h = sessionHashAppendI64(h, sessionGetI64(a));
+        a += 8;
+      }else{
+        int n; 
+        a += sessionVarintGet(a, &n);
+        h = sessionHashAppendBlob(h, n, a);
+        a += n;
+      }
+    }else{
+      a += sessionSerialLen(a);
+    }
+  }
+  return (h % nBucket);
+}
+
+/*
+** Arguments aLeft and aRight are pointers to change records for table pTab.
+** This function returns true if the two records apply to the same row (i.e.
+** have the same values stored in the primary key columns), or false 
+** otherwise.
+*/
+static int sessionChangeEqual(
+  SessionTable *pTab,             /* Table used for PK definition */
+  int bLeftPkOnly,                /* True if aLeft[] contains PK fields only */
+  u8 *aLeft,                      /* Change record */
+  int bRightPkOnly,               /* True if aRight[] contains PK fields only */
+  u8 *aRight                      /* Change record */
+){
+  u8 *a1 = aLeft;                 /* Cursor to iterate through aLeft */
+  u8 *a2 = aRight;                /* Cursor to iterate through aRight */
+  int iCol;                       /* Used to iterate through table columns */
+
+  for(iCol=0; iCol<pTab->nCol; iCol++){
+    if( pTab->abPK[iCol] ){
+      int n1 = sessionSerialLen(a1);
+      int n2 = sessionSerialLen(a2);
+
+      if( pTab->abPK[iCol] && (n1!=n2 || memcmp(a1, a2, n1)) ){
+        return 0;
+      }
+      a1 += n1;
+      a2 += n2;
+    }else{
+      if( bLeftPkOnly==0 ) a1 += sessionSerialLen(a1);
+      if( bRightPkOnly==0 ) a2 += sessionSerialLen(a2);
+    }
+  }
+
+  return 1;
+}
+
+/*
+** Arguments aLeft and aRight both point to buffers containing change
+** records with nCol columns. This function "merges" the two records into
+** a single records which is written to the buffer at *paOut. *paOut is
+** then set to point to one byte after the last byte written before 
+** returning.
+**
+** The merging of records is done as follows: For each column, if the 
+** aRight record contains a value for the column, copy the value from
+** their. Otherwise, if aLeft contains a value, copy it. If neither
+** record contains a value for a given column, then neither does the
+** output record.
+*/
+static void sessionMergeRecord(
+  u8 **paOut, 
+  int nCol,
+  u8 *aLeft,
+  u8 *aRight
+){
+  u8 *a1 = aLeft;                 /* Cursor used to iterate through aLeft */
+  u8 *a2 = aRight;                /* Cursor used to iterate through aRight */
+  u8 *aOut = *paOut;              /* Output cursor */
+  int iCol;                       /* Used to iterate from 0 to nCol */
+
+  for(iCol=0; iCol<nCol; iCol++){
+    int n1 = sessionSerialLen(a1);
+    int n2 = sessionSerialLen(a2);
+    if( *a2 ){
+      memcpy(aOut, a2, n2);
+      aOut += n2;
+    }else{
+      memcpy(aOut, a1, n1);
+      aOut += n1;
+    }
+    a1 += n1;
+    a2 += n2;
+  }
+
+  *paOut = aOut;
+}
+
+/*
+** This is a helper function used by sessionMergeUpdate().
+**
+** When this function is called, both *paOne and *paTwo point to a value 
+** within a change record. Before it returns, both have been advanced so 
+** as to point to the next value in the record.
+**
+** If, when this function is called, *paTwo points to a valid value (i.e.
+** *paTwo[0] is not 0x00 - the "no value" placeholder), a copy of the *paTwo
+** pointer is returned and *pnVal is set to the number of bytes in the 
+** serialized value. Otherwise, a copy of *paOne is returned and *pnVal
+** set to the number of bytes in the value at *paOne. If *paOne points
+** to the "no value" placeholder, *pnVal is set to 1. In other words:
+**
+**   if( *paTwo is valid ) return *paTwo;
+**   return *paOne;
+**
+*/
+static u8 *sessionMergeValue(
+  u8 **paOne,                     /* IN/OUT: Left-hand buffer pointer */
+  u8 **paTwo,                     /* IN/OUT: Right-hand buffer pointer */
+  int *pnVal                      /* OUT: Bytes in returned value */
+){
+  u8 *a1 = *paOne;
+  u8 *a2 = *paTwo;
+  u8 *pRet = 0;
+  int n1;
+
+  assert( a1 );
+  if( a2 ){
+    int n2 = sessionSerialLen(a2);
+    if( *a2 ){
+      *pnVal = n2;
+      pRet = a2;
+    }
+    *paTwo = &a2[n2];
+  }
+
+  n1 = sessionSerialLen(a1);
+  if( pRet==0 ){
+    *pnVal = n1;
+    pRet = a1;
+  }
+  *paOne = &a1[n1];
+
+  return pRet;
+}
+
+/*
+** This function is used by changeset_concat() to merge two UPDATE changes
+** on the same row.
+*/
+static int sessionMergeUpdate(
+  u8 **paOut,                     /* IN/OUT: Pointer to output buffer */
+  SessionTable *pTab,             /* Table change pertains to */
+  int bPatchset,                  /* True if records are patchset records */
+  u8 *aOldRecord1,                /* old.* record for first change */
+  u8 *aOldRecord2,                /* old.* record for second change */
+  u8 *aNewRecord1,                /* new.* record for first change */
+  u8 *aNewRecord2                 /* new.* record for second change */
+){
+  u8 *aOld1 = aOldRecord1;
+  u8 *aOld2 = aOldRecord2;
+  u8 *aNew1 = aNewRecord1;
+  u8 *aNew2 = aNewRecord2;
+
+  u8 *aOut = *paOut;
+  int i;
+
+  if( bPatchset==0 ){
+    int bRequired = 0;
+
+    assert( aOldRecord1 && aNewRecord1 );
+
+    /* Write the old.* vector first. */
+    for(i=0; i<pTab->nCol; i++){
+      int nOld;
+      u8 *aOld;
+      int nNew;
+      u8 *aNew;
+
+      aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);
+      aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);
+      if( pTab->abPK[i] || nOld!=nNew || memcmp(aOld, aNew, nNew) ){
+        if( pTab->abPK[i]==0 ) bRequired = 1;
+        memcpy(aOut, aOld, nOld);
+        aOut += nOld;
+      }else{
+        *(aOut++) = '\0';
+      }
+    }
+
+    if( !bRequired ) return 0;
+  }
+
+  /* Write the new.* vector */
+  aOld1 = aOldRecord1;
+  aOld2 = aOldRecord2;
+  aNew1 = aNewRecord1;
+  aNew2 = aNewRecord2;
+  for(i=0; i<pTab->nCol; i++){
+    int nOld;
+    u8 *aOld;
+    int nNew;
+    u8 *aNew;
+
+    aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);
+    aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);
+    if( bPatchset==0 
+     && (pTab->abPK[i] || (nOld==nNew && 0==memcmp(aOld, aNew, nNew))) 
+    ){
+      *(aOut++) = '\0';
+    }else{
+      memcpy(aOut, aNew, nNew);
+      aOut += nNew;
+    }
+  }
+
+  *paOut = aOut;
+  return 1;
+}
+
+/*
+** This function is only called from within a pre-update-hook callback.
+** It determines if the current pre-update-hook change affects the same row
+** as the change stored in argument pChange. If so, it returns true. Otherwise
+** if the pre-update-hook does not affect the same row as pChange, it returns
+** false.
+*/
+static int sessionPreupdateEqual(
+  sqlite3_session *pSession,      /* Session object that owns SessionTable */
+  SessionTable *pTab,             /* Table associated with change */
+  SessionChange *pChange,         /* Change to compare to */
+  int op                          /* Current pre-update operation */
+){
+  int iCol;                       /* Used to iterate through columns */
+  u8 *a = pChange->aRecord;       /* Cursor used to scan change record */
+
+  assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
+  for(iCol=0; iCol<pTab->nCol; iCol++){
+    if( !pTab->abPK[iCol] ){
+      a += sessionSerialLen(a);
+    }else{
+      sqlite3_value *pVal;        /* Value returned by preupdate_new/old */
+      int rc;                     /* Error code from preupdate_new/old */
+      int eType = *a++;           /* Type of value from change record */
+
+      /* The following calls to preupdate_new() and preupdate_old() can not
+      ** fail. This is because they cache their return values, and by the
+      ** time control flows to here they have already been called once from
+      ** within sessionPreupdateHash(). The first two asserts below verify
+      ** this (that the method has already been called). */
+      if( op==SQLITE_INSERT ){
+        /* assert( db->pPreUpdate->pNewUnpacked || db->pPreUpdate->aNew ); */
+        rc = pSession->hook.xNew(pSession->hook.pCtx, iCol, &pVal);
+      }else{
+        /* assert( db->pPreUpdate->pUnpacked ); */
+        rc = pSession->hook.xOld(pSession->hook.pCtx, iCol, &pVal);
+      }
+      assert( rc==SQLITE_OK );
+      if( sqlite3_value_type(pVal)!=eType ) return 0;
+
+      /* A SessionChange object never has a NULL value in a PK column */
+      assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT
+           || eType==SQLITE_BLOB    || eType==SQLITE_TEXT
+      );
+
+      if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+        i64 iVal = sessionGetI64(a);
+        a += 8;
+        if( eType==SQLITE_INTEGER ){
+          if( sqlite3_value_int64(pVal)!=iVal ) return 0;
+        }else{
+          double rVal;
+          assert( sizeof(iVal)==8 && sizeof(rVal)==8 );
+          memcpy(&rVal, &iVal, 8);
+          if( sqlite3_value_double(pVal)!=rVal ) return 0;
+        }
+      }else{
+        int n;
+        const u8 *z;
+        a += sessionVarintGet(a, &n);
+        if( sqlite3_value_bytes(pVal)!=n ) return 0;
+        if( eType==SQLITE_TEXT ){
+          z = sqlite3_value_text(pVal);
+        }else{
+          z = sqlite3_value_blob(pVal);
+        }
+        if( memcmp(a, z, n) ) return 0;
+        a += n;
+        break;
+      }
+    }
+  }
+
+  return 1;
+}
+
+/*
+** If required, grow the hash table used to store changes on table pTab 
+** (part of the session pSession). If a fatal OOM error occurs, set the
+** session object to failed and return SQLITE_ERROR. Otherwise, return
+** SQLITE_OK.
+**
+** It is possible that a non-fatal OOM error occurs in this function. In
+** that case the hash-table does not grow, but SQLITE_OK is returned anyway.
+** Growing the hash table in this case is a performance optimization only,
+** it is not required for correct operation.
+*/
+static int sessionGrowHash(int bPatchset, SessionTable *pTab){
+  if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){
+    int i;
+    SessionChange **apNew;
+    int nNew = (pTab->nChange ? pTab->nChange : 128) * 2;
+
+    apNew = (SessionChange **)sqlite3_malloc(sizeof(SessionChange *) * nNew);
+    if( apNew==0 ){
+      if( pTab->nChange==0 ){
+        return SQLITE_ERROR;
+      }
+      return SQLITE_OK;
+    }
+    memset(apNew, 0, sizeof(SessionChange *) * nNew);
+
+    for(i=0; i<pTab->nChange; i++){
+      SessionChange *p;
+      SessionChange *pNext;
+      for(p=pTab->apChange[i]; p; p=pNext){
+        int bPkOnly = (p->op==SQLITE_DELETE && bPatchset);
+        int iHash = sessionChangeHash(pTab, bPkOnly, p->aRecord, nNew);
+        pNext = p->pNext;
+        p->pNext = apNew[iHash];
+        apNew[iHash] = p;
+      }
+    }
+
+    sqlite3_free(pTab->apChange);
+    pTab->nChange = nNew;
+    pTab->apChange = apNew;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** This function queries the database for the names of the columns of table
+** zThis, in schema zDb. It is expected that the table has nCol columns. If
+** not, SQLITE_SCHEMA is returned and none of the output variables are
+** populated.
+**
+** Otherwise, if they are not NULL, variable *pnCol is set to the number
+** of columns in the database table and variable *pzTab is set to point to a
+** nul-terminated copy of the table name. *pazCol (if not NULL) is set to
+** point to an array of pointers to column names. And *pabPK (again, if not
+** NULL) is set to point to an array of booleans - true if the corresponding
+** column is part of the primary key.
+**
+** For example, if the table is declared as:
+**
+**     CREATE TABLE tbl1(w, x, y, z, PRIMARY KEY(w, z));
+**
+** Then the four output variables are populated as follows:
+**
+**     *pnCol  = 4
+**     *pzTab  = "tbl1"
+**     *pazCol = {"w", "x", "y", "z"}
+**     *pabPK  = {1, 0, 0, 1}
+**
+** All returned buffers are part of the same single allocation, which must
+** be freed using sqlite3_free() by the caller. If pazCol was not NULL, then
+** pointer *pazCol should be freed to release all memory. Otherwise, pointer
+** *pabPK. It is illegal for both pazCol and pabPK to be NULL.
+*/
+static int sessionTableInfo(
+  sqlite3 *db,                    /* Database connection */
+  const char *zDb,                /* Name of attached database (e.g. "main") */
+  const char *zThis,              /* Table name */
+  int *pnCol,                     /* OUT: number of columns */
+  const char **pzTab,             /* OUT: Copy of zThis */
+  const char ***pazCol,           /* OUT: Array of column names for table */
+  u8 **pabPK                      /* OUT: Array of booleans - true for PK col */
+){
+  char *zPragma;
+  sqlite3_stmt *pStmt;
+  int rc;
+  int nByte;
+  int nDbCol = 0;
+  int nThis;
+  int i;
+  u8 *pAlloc = 0;
+  char **azCol = 0;
+  u8 *abPK = 0;
+
+  assert( pazCol && pabPK );
+
+  nThis = sqlite3Strlen30(zThis);
+  zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis);
+  if( !zPragma ) return SQLITE_NOMEM;
+
+  rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0);
+  sqlite3_free(zPragma);
+  if( rc!=SQLITE_OK ) return rc;
+
+  nByte = nThis + 1;
+  while( SQLITE_ROW==sqlite3_step(pStmt) ){
+    nByte += sqlite3_column_bytes(pStmt, 1);
+    nDbCol++;
+  }
+  rc = sqlite3_reset(pStmt);
+
+  if( rc==SQLITE_OK ){
+    nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);
+    pAlloc = sqlite3_malloc(nByte);
+    if( pAlloc==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+  if( rc==SQLITE_OK ){
+    azCol = (char **)pAlloc;
+    pAlloc = (u8 *)&azCol[nDbCol];
+    abPK = (u8 *)pAlloc;
+    pAlloc = &abPK[nDbCol];
+    if( pzTab ){
+      memcpy(pAlloc, zThis, nThis+1);
+      *pzTab = (char *)pAlloc;
+      pAlloc += nThis+1;
+    }
+  
+    i = 0;
+    while( SQLITE_ROW==sqlite3_step(pStmt) ){
+      int nName = sqlite3_column_bytes(pStmt, 1);
+      const unsigned char *zName = sqlite3_column_text(pStmt, 1);
+      if( zName==0 ) break;
+      memcpy(pAlloc, zName, nName+1);
+      azCol[i] = (char *)pAlloc;
+      pAlloc += nName+1;
+      abPK[i] = sqlite3_column_int(pStmt, 5);
+      i++;
+    }
+    rc = sqlite3_reset(pStmt);
+  
+  }
+
+  /* If successful, populate the output variables. Otherwise, zero them and
+  ** free any allocation made. An error code will be returned in this case.
+  */
+  if( rc==SQLITE_OK ){
+    *pazCol = (const char **)azCol;
+    *pabPK = abPK;
+    *pnCol = nDbCol;
+  }else{
+    *pazCol = 0;
+    *pabPK = 0;
+    *pnCol = 0;
+    if( pzTab ) *pzTab = 0;
+    sqlite3_free(azCol);
+  }
+  sqlite3_finalize(pStmt);
+  return rc;
+}
+
+/*
+** This function is only called from within a pre-update handler for a
+** write to table pTab, part of session pSession. If this is the first
+** write to this table, initalize the SessionTable.nCol, azCol[] and
+** abPK[] arrays accordingly.
+**
+** If an error occurs, an error code is stored in sqlite3_session.rc and
+** non-zero returned. Or, if no error occurs but the table has no primary
+** key, sqlite3_session.rc is left set to SQLITE_OK and non-zero returned to
+** indicate that updates on this table should be ignored. SessionTable.abPK 
+** is set to NULL in this case.
+*/
+static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){
+  if( pTab->nCol==0 ){
+    u8 *abPK;
+    assert( pTab->azCol==0 || pTab->abPK==0 );
+    pSession->rc = sessionTableInfo(pSession->db, pSession->zDb, 
+        pTab->zName, &pTab->nCol, 0, &pTab->azCol, &abPK
+    );
+    if( pSession->rc==SQLITE_OK ){
+      int i;
+      for(i=0; i<pTab->nCol; i++){
+        if( abPK[i] ){
+          pTab->abPK = abPK;
+          break;
+        }
+      }
+    }
+  }
+  return (pSession->rc || pTab->abPK==0);
+}
+
+/*
+** This function is only called from with a pre-update-hook reporting a 
+** change on table pTab (attached to session pSession). The type of change
+** (UPDATE, INSERT, DELETE) is specified by the first argument.
+**
+** Unless one is already present or an error occurs, an entry is added
+** to the changed-rows hash table associated with table pTab.
+*/
+static void sessionPreupdateOneChange(
+  int op,                         /* One of SQLITE_UPDATE, INSERT, DELETE */
+  sqlite3_session *pSession,      /* Session object pTab is attached to */
+  SessionTable *pTab              /* Table that change applies to */
+){
+  int iHash; 
+  int bNull = 0; 
+  int rc = SQLITE_OK;
+
+  if( pSession->rc ) return;
+
+  /* Load table details if required */
+  if( sessionInitTable(pSession, pTab) ) return;
+
+  /* Check the number of columns in this xPreUpdate call matches the 
+  ** number of columns in the table.  */
+  if( pTab->nCol!=pSession->hook.xCount(pSession->hook.pCtx) ){
+    pSession->rc = SQLITE_SCHEMA;
+    return;
+  }
+
+  /* Grow the hash table if required */
+  if( sessionGrowHash(0, pTab) ){
+    pSession->rc = SQLITE_NOMEM;
+    return;
+  }
+
+  /* Calculate the hash-key for this change. If the primary key of the row
+  ** includes a NULL value, exit early. Such changes are ignored by the
+  ** session module. */
+  rc = sessionPreupdateHash(pSession, pTab, op==SQLITE_INSERT, &iHash, &bNull);
+  if( rc!=SQLITE_OK ) goto error_out;
+
+  if( bNull==0 ){
+    /* Search the hash table for an existing record for this row. */
+    SessionChange *pC;
+    for(pC=pTab->apChange[iHash]; pC; pC=pC->pNext){
+      if( sessionPreupdateEqual(pSession, pTab, pC, op) ) break;
+    }
+
+    if( pC==0 ){
+      /* Create a new change object containing all the old values (if
+      ** this is an SQLITE_UPDATE or SQLITE_DELETE), or just the PK
+      ** values (if this is an INSERT). */
+      SessionChange *pChange; /* New change object */
+      int nByte;              /* Number of bytes to allocate */
+      int i;                  /* Used to iterate through columns */
+  
+      assert( rc==SQLITE_OK );
+      pTab->nEntry++;
+  
+      /* Figure out how large an allocation is required */
+      nByte = sizeof(SessionChange);
+      for(i=0; i<pTab->nCol; i++){
+        sqlite3_value *p = 0;
+        if( op!=SQLITE_INSERT ){
+          TESTONLY(int trc = ) pSession->hook.xOld(pSession->hook.pCtx, i, &p);
+          assert( trc==SQLITE_OK );
+        }else if( pTab->abPK[i] ){
+          TESTONLY(int trc = ) pSession->hook.xNew(pSession->hook.pCtx, i, &p);
+          assert( trc==SQLITE_OK );
+        }
+
+        /* This may fail if SQLite value p contains a utf-16 string that must
+        ** be converted to utf-8 and an OOM error occurs while doing so. */
+        rc = sessionSerializeValue(0, p, &nByte);
+        if( rc!=SQLITE_OK ) goto error_out;
+      }
+  
+      /* Allocate the change object */
+      pChange = (SessionChange *)sqlite3_malloc(nByte);
+      if( !pChange ){
+        rc = SQLITE_NOMEM;
+        goto error_out;
+      }else{
+        memset(pChange, 0, sizeof(SessionChange));
+        pChange->aRecord = (u8 *)&pChange[1];
+      }
+  
+      /* Populate the change object. None of the preupdate_old(),
+      ** preupdate_new() or SerializeValue() calls below may fail as all
+      ** required values and encodings have already been cached in memory.
+      ** It is not possible for an OOM to occur in this block. */
+      nByte = 0;
+      for(i=0; i<pTab->nCol; i++){
+        sqlite3_value *p = 0;
+        if( op!=SQLITE_INSERT ){
+          pSession->hook.xOld(pSession->hook.pCtx, i, &p);
+        }else if( pTab->abPK[i] ){
+          pSession->hook.xNew(pSession->hook.pCtx, i, &p);
+        }
+        sessionSerializeValue(&pChange->aRecord[nByte], p, &nByte);
+      }
+
+      /* Add the change to the hash-table */
+      if( pSession->bIndirect || pSession->hook.xDepth(pSession->hook.pCtx) ){
+        pChange->bIndirect = 1;
+      }
+      pChange->nRecord = nByte;
+      pChange->op = op;
+      pChange->pNext = pTab->apChange[iHash];
+      pTab->apChange[iHash] = pChange;
+
+    }else if( pC->bIndirect ){
+      /* If the existing change is considered "indirect", but this current
+      ** change is "direct", mark the change object as direct. */
+      if( pSession->hook.xDepth(pSession->hook.pCtx)==0 
+       && pSession->bIndirect==0 
+      ){
+        pC->bIndirect = 0;
+      }
+    }
+  }
+
+  /* If an error has occurred, mark the session object as failed. */
+ error_out:
+  if( rc!=SQLITE_OK ){
+    pSession->rc = rc;
+  }
+}
+
+static int sessionFindTable(
+  sqlite3_session *pSession, 
+  const char *zName,
+  SessionTable **ppTab
+){
+  int rc = SQLITE_OK;
+  int nName = sqlite3Strlen30(zName);
+  SessionTable *pRet;
+
+  /* Search for an existing table */
+  for(pRet=pSession->pTable; pRet; pRet=pRet->pNext){
+    if( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) ) break;
+  }
+
+  if( pRet==0 && pSession->bAutoAttach ){
+    /* If there is a table-filter configured, invoke it. If it returns 0,
+    ** do not automatically add the new table. */
+    if( pSession->xTableFilter==0
+     || pSession->xTableFilter(pSession->pFilterCtx, zName) 
+    ){
+      rc = sqlite3session_attach(pSession, zName);
+      if( rc==SQLITE_OK ){
+        for(pRet=pSession->pTable; pRet->pNext; pRet=pRet->pNext);
+        assert( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) );
+      }
+    }
+  }
+
+  assert( rc==SQLITE_OK || pRet==0 );
+  *ppTab = pRet;
+  return rc;
+}
+
+/*
+** The 'pre-update' hook registered by this module with SQLite databases.
+*/
+static void xPreUpdate(
+  void *pCtx,                     /* Copy of third arg to preupdate_hook() */
+  sqlite3 *db,                    /* Database handle */
+  int op,                         /* SQLITE_UPDATE, DELETE or INSERT */
+  char const *zDb,                /* Database name */
+  char const *zName,              /* Table name */
+  sqlite3_int64 iKey1,            /* Rowid of row about to be deleted/updated */
+  sqlite3_int64 iKey2             /* New rowid value (for a rowid UPDATE) */
+){
+  sqlite3_session *pSession;
+  int nDb = sqlite3Strlen30(zDb);
+
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  for(pSession=(sqlite3_session *)pCtx; pSession; pSession=pSession->pNext){
+    SessionTable *pTab;
+
+    /* If this session is attached to a different database ("main", "temp" 
+    ** etc.), or if it is not currently enabled, there is nothing to do. Skip 
+    ** to the next session object attached to this database. */
+    if( pSession->bEnable==0 ) continue;
+    if( pSession->rc ) continue;
+    if( sqlite3_strnicmp(zDb, pSession->zDb, nDb+1) ) continue;
+
+    pSession->rc = sessionFindTable(pSession, zName, &pTab);
+    if( pTab ){
+      assert( pSession->rc==SQLITE_OK );
+      sessionPreupdateOneChange(op, pSession, pTab);
+      if( op==SQLITE_UPDATE ){
+        sessionPreupdateOneChange(SQLITE_INSERT, pSession, pTab);
+      }
+    }
+  }
+}
+
+/*
+** The pre-update hook implementations.
+*/
+static int sessionPreupdateOld(void *pCtx, int iVal, sqlite3_value **ppVal){
+  return sqlite3_preupdate_old((sqlite3*)pCtx, iVal, ppVal);
+}
+static int sessionPreupdateNew(void *pCtx, int iVal, sqlite3_value **ppVal){
+  return sqlite3_preupdate_new((sqlite3*)pCtx, iVal, ppVal);
+}
+static int sessionPreupdateCount(void *pCtx){
+  return sqlite3_preupdate_count((sqlite3*)pCtx);
+}
+static int sessionPreupdateDepth(void *pCtx){
+  return sqlite3_preupdate_depth((sqlite3*)pCtx);
+}
+
+/*
+** Install the pre-update hooks on the session object passed as the only
+** argument.
+*/
+static void sessionPreupdateHooks(
+  sqlite3_session *pSession
+){
+  pSession->hook.pCtx = (void*)pSession->db;
+  pSession->hook.xOld = sessionPreupdateOld;
+  pSession->hook.xNew = sessionPreupdateNew;
+  pSession->hook.xCount = sessionPreupdateCount;
+  pSession->hook.xDepth = sessionPreupdateDepth;
+}
+
+typedef struct SessionDiffCtx SessionDiffCtx;
+struct SessionDiffCtx {
+  sqlite3_stmt *pStmt;
+  int nOldOff;
+};
+
+/*
+** The diff hook implementations.
+*/
+static int sessionDiffOld(void *pCtx, int iVal, sqlite3_value **ppVal){
+  SessionDiffCtx *p = (SessionDiffCtx*)pCtx;
+  *ppVal = sqlite3_column_value(p->pStmt, iVal+p->nOldOff);
+  return SQLITE_OK;
+}
+static int sessionDiffNew(void *pCtx, int iVal, sqlite3_value **ppVal){
+  SessionDiffCtx *p = (SessionDiffCtx*)pCtx;
+  *ppVal = sqlite3_column_value(p->pStmt, iVal);
+   return SQLITE_OK;
+}
+static int sessionDiffCount(void *pCtx){
+  SessionDiffCtx *p = (SessionDiffCtx*)pCtx;
+  return p->nOldOff ? p->nOldOff : sqlite3_column_count(p->pStmt);
+}
+static int sessionDiffDepth(void *pCtx){
+  return 0;
+}
+
+/*
+** Install the diff hooks on the session object passed as the only
+** argument.
+*/
+static void sessionDiffHooks(
+  sqlite3_session *pSession,
+  SessionDiffCtx *pDiffCtx
+){
+  pSession->hook.pCtx = (void*)pDiffCtx;
+  pSession->hook.xOld = sessionDiffOld;
+  pSession->hook.xNew = sessionDiffNew;
+  pSession->hook.xCount = sessionDiffCount;
+  pSession->hook.xDepth = sessionDiffDepth;
+}
+
+static char *sessionExprComparePK(
+  int nCol,
+  const char *zDb1, const char *zDb2, 
+  const char *zTab,
+  const char **azCol, u8 *abPK
+){
+  int i;
+  const char *zSep = "";
+  char *zRet = 0;
+
+  for(i=0; i<nCol; i++){
+    if( abPK[i] ){
+      zRet = sqlite3_mprintf("%z%s\"%w\".\"%w\".\"%w\"=\"%w\".\"%w\".\"%w\"",
+          zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i]
+      );
+      zSep = " AND ";
+      if( zRet==0 ) break;
+    }
+  }
+
+  return zRet;
+}
+
+static char *sessionExprCompareOther(
+  int nCol,
+  const char *zDb1, const char *zDb2, 
+  const char *zTab,
+  const char **azCol, u8 *abPK
+){
+  int i;
+  const char *zSep = "";
+  char *zRet = 0;
+  int bHave = 0;
+
+  for(i=0; i<nCol; i++){
+    if( abPK[i]==0 ){
+      bHave = 1;
+      zRet = sqlite3_mprintf(
+          "%z%s\"%w\".\"%w\".\"%w\" IS NOT \"%w\".\"%w\".\"%w\"",
+          zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i]
+      );
+      zSep = " OR ";
+      if( zRet==0 ) break;
+    }
+  }
+
+  if( bHave==0 ){
+    assert( zRet==0 );
+    zRet = sqlite3_mprintf("0");
+  }
+
+  return zRet;
+}
+
+static char *sessionSelectFindNew(
+  int nCol,
+  const char *zDb1,      /* Pick rows in this db only */
+  const char *zDb2,      /* But not in this one */
+  const char *zTbl,      /* Table name */
+  const char *zExpr
+){
+  char *zRet = sqlite3_mprintf(
+      "SELECT * FROM \"%w\".\"%w\" WHERE NOT EXISTS ("
+      "  SELECT 1 FROM \"%w\".\"%w\" WHERE %s"
+      ")",
+      zDb1, zTbl, zDb2, zTbl, zExpr
+  );
+  return zRet;
+}
+
+static int sessionDiffFindNew(
+  int op,
+  sqlite3_session *pSession,
+  SessionTable *pTab,
+  const char *zDb1,
+  const char *zDb2,
+  char *zExpr
+){
+  int rc = SQLITE_OK;
+  char *zStmt = sessionSelectFindNew(pTab->nCol, zDb1, zDb2, pTab->zName,zExpr);
+
+  if( zStmt==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    sqlite3_stmt *pStmt;
+    rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx;
+      pDiffCtx->pStmt = pStmt;
+      pDiffCtx->nOldOff = 0;
+      while( SQLITE_ROW==sqlite3_step(pStmt) ){
+        sessionPreupdateOneChange(op, pSession, pTab);
+      }
+      rc = sqlite3_finalize(pStmt);
+    }
+    sqlite3_free(zStmt);
+  }
+
+  return rc;
+}
+
+static int sessionDiffFindModified(
+  sqlite3_session *pSession, 
+  SessionTable *pTab, 
+  const char *zFrom, 
+  const char *zExpr
+){
+  int rc = SQLITE_OK;
+
+  char *zExpr2 = sessionExprCompareOther(pTab->nCol,
+      pSession->zDb, zFrom, pTab->zName, pTab->azCol, pTab->abPK
+  );
+  if( zExpr2==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    char *zStmt = sqlite3_mprintf(
+        "SELECT * FROM \"%w\".\"%w\", \"%w\".\"%w\" WHERE %s AND (%z)",
+        pSession->zDb, pTab->zName, zFrom, pTab->zName, zExpr, zExpr2
+    );
+    if( zStmt==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      sqlite3_stmt *pStmt;
+      rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0);
+
+      if( rc==SQLITE_OK ){
+        SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx;
+        pDiffCtx->pStmt = pStmt;
+        pDiffCtx->nOldOff = pTab->nCol;
+        while( SQLITE_ROW==sqlite3_step(pStmt) ){
+          sessionPreupdateOneChange(SQLITE_UPDATE, pSession, pTab);
+        }
+        rc = sqlite3_finalize(pStmt);
+      }
+      sqlite3_free(zStmt);
+    }
+  }
+
+  return rc;
+}
+
+SQLITE_API int SQLITE_STDCALL sqlite3session_diff(
+  sqlite3_session *pSession,
+  const char *zFrom,
+  const char *zTbl,
+  char **pzErrMsg
+){
+  const char *zDb = pSession->zDb;
+  int rc = pSession->rc;
+  SessionDiffCtx d;
+
+  memset(&d, 0, sizeof(d));
+  sessionDiffHooks(pSession, &d);
+
+  sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
+  if( pzErrMsg ) *pzErrMsg = 0;
+  if( rc==SQLITE_OK ){
+    char *zExpr = 0;
+    sqlite3 *db = pSession->db;
+    SessionTable *pTo;            /* Table zTbl */
+
+    /* Locate and if necessary initialize the target table object */
+    rc = sessionFindTable(pSession, zTbl, &pTo);
+    if( pTo==0 ) goto diff_out;
+    if( sessionInitTable(pSession, pTo) ){
+      rc = pSession->rc;
+      goto diff_out;
+    }
+
+    /* Check the table schemas match */
+    if( rc==SQLITE_OK ){
+      int bHasPk = 0;
+      int bMismatch = 0;
+      int nCol;                   /* Columns in zFrom.zTbl */
+      u8 *abPK;
+      const char **azCol = 0;
+      rc = sessionTableInfo(db, zFrom, zTbl, &nCol, 0, &azCol, &abPK);
+      if( rc==SQLITE_OK ){
+        if( pTo->nCol!=nCol ){
+          bMismatch = 1;
+        }else{
+          int i;
+          for(i=0; i<nCol; i++){
+            if( pTo->abPK[i]!=abPK[i] ) bMismatch = 1;
+            if( sqlite3_stricmp(azCol[i], pTo->azCol[i]) ) bMismatch = 1;
+            if( abPK[i] ) bHasPk = 1;
+          }
+        }
+
+      }
+      sqlite3_free((char*)azCol);
+      if( bMismatch ){
+        *pzErrMsg = sqlite3_mprintf("table schemas do not match");
+        rc = SQLITE_SCHEMA;
+      }
+      if( bHasPk==0 ){
+        /* Ignore tables with no primary keys */
+        goto diff_out;
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      zExpr = sessionExprComparePK(pTo->nCol, 
+          zDb, zFrom, pTo->zName, pTo->azCol, pTo->abPK
+      );
+    }
+
+    /* Find new rows */
+    if( rc==SQLITE_OK ){
+      rc = sessionDiffFindNew(SQLITE_INSERT, pSession, pTo, zDb, zFrom, zExpr);
+    }
+
+    /* Find old rows */
+    if( rc==SQLITE_OK ){
+      rc = sessionDiffFindNew(SQLITE_DELETE, pSession, pTo, zFrom, zDb, zExpr);
+    }
+
+    /* Find modified rows */
+    if( rc==SQLITE_OK ){
+      rc = sessionDiffFindModified(pSession, pTo, zFrom, zExpr);
+    }
+
+    sqlite3_free(zExpr);
+  }
+
+ diff_out:
+  sessionPreupdateHooks(pSession);
+  sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
+  return rc;
+}
+
+/*
+** Create a session object. This session object will record changes to
+** database zDb attached to connection db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_create(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of db (e.g. "main") */
+  sqlite3_session **ppSession     /* OUT: New session object */
+){
+  sqlite3_session *pNew;          /* Newly allocated session object */
+  sqlite3_session *pOld;          /* Session object already attached to db */
+  int nDb = sqlite3Strlen30(zDb); /* Length of zDb in bytes */
+
+  /* Zero the output value in case an error occurs. */
+  *ppSession = 0;
+
+  /* Allocate and populate the new session object. */
+  pNew = (sqlite3_session *)sqlite3_malloc(sizeof(sqlite3_session) + nDb + 1);
+  if( !pNew ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(sqlite3_session));
+  pNew->db = db;
+  pNew->zDb = (char *)&pNew[1];
+  pNew->bEnable = 1;
+  memcpy(pNew->zDb, zDb, nDb+1);
+  sessionPreupdateHooks(pNew);
+
+  /* Add the new session object to the linked list of session objects 
+  ** attached to database handle $db. Do this under the cover of the db
+  ** handle mutex.  */
+  sqlite3_mutex_enter(sqlite3_db_mutex(db));
+  pOld = (sqlite3_session*)sqlite3_preupdate_hook(db, xPreUpdate, (void*)pNew);
+  pNew->pNext = pOld;
+  sqlite3_mutex_leave(sqlite3_db_mutex(db));
+
+  *ppSession = pNew;
+  return SQLITE_OK;
+}
+
+/*
+** Free the list of table objects passed as the first argument. The contents
+** of the changed-rows hash tables are also deleted.
+*/
+static void sessionDeleteTable(SessionTable *pList){
+  SessionTable *pNext;
+  SessionTable *pTab;
+
+  for(pTab=pList; pTab; pTab=pNext){
+    int i;
+    pNext = pTab->pNext;
+    for(i=0; i<pTab->nChange; i++){
+      SessionChange *p;
+      SessionChange *pNextChange;
+      for(p=pTab->apChange[i]; p; p=pNextChange){
+        pNextChange = p->pNext;
+        sqlite3_free(p);
+      }
+    }
+    sqlite3_free((char*)pTab->azCol);  /* cast works around VC++ bug */
+    sqlite3_free(pTab->apChange);
+    sqlite3_free(pTab);
+  }
+}
+
+/*
+** Delete a session object previously allocated using sqlite3session_create().
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3session_delete(sqlite3_session *pSession){
+  sqlite3 *db = pSession->db;
+  sqlite3_session *pHead;
+  sqlite3_session **pp;
+
+  /* Unlink the session from the linked list of sessions attached to the
+  ** database handle. Hold the db mutex while doing so.  */
+  sqlite3_mutex_enter(sqlite3_db_mutex(db));
+  pHead = (sqlite3_session*)sqlite3_preupdate_hook(db, 0, 0);
+  for(pp=&pHead; ALWAYS((*pp)!=0); pp=&((*pp)->pNext)){
+    if( (*pp)==pSession ){
+      *pp = (*pp)->pNext;
+      if( pHead ) sqlite3_preupdate_hook(db, xPreUpdate, (void*)pHead);
+      break;
+    }
+  }
+  sqlite3_mutex_leave(sqlite3_db_mutex(db));
+
+  /* Delete all attached table objects. And the contents of their 
+  ** associated hash-tables. */
+  sessionDeleteTable(pSession->pTable);
+
+  /* Free the session object itself. */
+  sqlite3_free(pSession);
+}
+
+/*
+** Set a table filter on a Session Object.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3session_table_filter(
+  sqlite3_session *pSession, 
+  int(*xFilter)(void*, const char*),
+  void *pCtx                      /* First argument passed to xFilter */
+){
+  pSession->bAutoAttach = 1;
+  pSession->pFilterCtx = pCtx;
+  pSession->xTableFilter = xFilter;
+}
+
+/*
+** Attach a table to a session. All subsequent changes made to the table
+** while the session object is enabled will be recorded.
+**
+** Only tables that have a PRIMARY KEY defined may be attached. It does
+** not matter if the PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias)
+** or not.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_attach(
+  sqlite3_session *pSession,      /* Session object */
+  const char *zName               /* Table name */
+){
+  int rc = SQLITE_OK;
+  sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
+
+  if( !zName ){
+    pSession->bAutoAttach = 1;
+  }else{
+    SessionTable *pTab;           /* New table object (if required) */
+    int nName;                    /* Number of bytes in string zName */
+
+    /* First search for an existing entry. If one is found, this call is
+    ** a no-op. Return early. */
+    nName = sqlite3Strlen30(zName);
+    for(pTab=pSession->pTable; pTab; pTab=pTab->pNext){
+      if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ) break;
+    }
+
+    if( !pTab ){
+      /* Allocate new SessionTable object. */
+      pTab = (SessionTable *)sqlite3_malloc(sizeof(SessionTable) + nName + 1);
+      if( !pTab ){
+        rc = SQLITE_NOMEM;
+      }else{
+        /* Populate the new SessionTable object and link it into the list.
+        ** The new object must be linked onto the end of the list, not 
+        ** simply added to the start of it in order to ensure that tables
+        ** appear in the correct order when a changeset or patchset is
+        ** eventually generated. */
+        SessionTable **ppTab;
+        memset(pTab, 0, sizeof(SessionTable));
+        pTab->zName = (char *)&pTab[1];
+        memcpy(pTab->zName, zName, nName+1);
+        for(ppTab=&pSession->pTable; *ppTab; ppTab=&(*ppTab)->pNext);
+        *ppTab = pTab;
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
+  return rc;
+}
+
+/*
+** Ensure that there is room in the buffer to append nByte bytes of data.
+** If not, use sqlite3_realloc() to grow the buffer so that there is.
+**
+** If successful, return zero. Otherwise, if an OOM condition is encountered,
+** set *pRc to SQLITE_NOMEM and return non-zero.
+*/
+static int sessionBufferGrow(SessionBuffer *p, int nByte, int *pRc){
+  if( *pRc==SQLITE_OK && p->nAlloc-p->nBuf<nByte ){
+    u8 *aNew;
+    int nNew = p->nAlloc ? p->nAlloc : 128;
+    do {
+      nNew = nNew*2;
+    }while( nNew<(p->nBuf+nByte) );
+
+    aNew = (u8 *)sqlite3_realloc(p->aBuf, nNew);
+    if( 0==aNew ){
+      *pRc = SQLITE_NOMEM;
+    }else{
+      p->aBuf = aNew;
+      p->nAlloc = nNew;
+    }
+  }
+  return (*pRc!=SQLITE_OK);
+}
+
+/*
+** Append the value passed as the second argument to the buffer passed
+** as the first.
+**
+** This function is a no-op if *pRc is non-zero when it is called.
+** Otherwise, if an error occurs, *pRc is set to an SQLite error code
+** before returning.
+*/
+static void sessionAppendValue(SessionBuffer *p, sqlite3_value *pVal, int *pRc){
+  int rc = *pRc;
+  if( rc==SQLITE_OK ){
+    int nByte = 0;
+    rc = sessionSerializeValue(0, pVal, &nByte);
+    sessionBufferGrow(p, nByte, &rc);
+    if( rc==SQLITE_OK ){
+      rc = sessionSerializeValue(&p->aBuf[p->nBuf], pVal, 0);
+      p->nBuf += nByte;
+    }else{
+      *pRc = rc;
+    }
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append a single byte to the buffer. 
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendByte(SessionBuffer *p, u8 v, int *pRc){
+  if( 0==sessionBufferGrow(p, 1, pRc) ){
+    p->aBuf[p->nBuf++] = v;
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append a single varint to the buffer. 
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendVarint(SessionBuffer *p, int v, int *pRc){
+  if( 0==sessionBufferGrow(p, 9, pRc) ){
+    p->nBuf += sessionVarintPut(&p->aBuf[p->nBuf], v);
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append a blob of data to the buffer. 
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendBlob(
+  SessionBuffer *p, 
+  const u8 *aBlob, 
+  int nBlob, 
+  int *pRc
+){
+  if( 0==sessionBufferGrow(p, nBlob, pRc) ){
+    memcpy(&p->aBuf[p->nBuf], aBlob, nBlob);
+    p->nBuf += nBlob;
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append a string to the buffer. All bytes in the string
+** up to (but not including) the nul-terminator are written to the buffer.
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendStr(
+  SessionBuffer *p, 
+  const char *zStr, 
+  int *pRc
+){
+  int nStr = sqlite3Strlen30(zStr);
+  if( 0==sessionBufferGrow(p, nStr, pRc) ){
+    memcpy(&p->aBuf[p->nBuf], zStr, nStr);
+    p->nBuf += nStr;
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append the string representation of integer iVal
+** to the buffer. No nul-terminator is written.
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendInteger(
+  SessionBuffer *p,               /* Buffer to append to */
+  int iVal,                       /* Value to write the string rep. of */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  char aBuf[24];
+  sqlite3_snprintf(sizeof(aBuf)-1, aBuf, "%d", iVal);
+  sessionAppendStr(p, aBuf, pRc);
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is 
+** called. Otherwise, append the string zStr enclosed in quotes (") and
+** with any embedded quote characters escaped to the buffer. No 
+** nul-terminator byte is written.
+**
+** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before
+** returning.
+*/
+static void sessionAppendIdent(
+  SessionBuffer *p,               /* Buffer to a append to */
+  const char *zStr,               /* String to quote, escape and append */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  int nStr = sqlite3Strlen30(zStr)*2 + 2 + 1;
+  if( 0==sessionBufferGrow(p, nStr, pRc) ){
+    char *zOut = (char *)&p->aBuf[p->nBuf];
+    const char *zIn = zStr;
+    *zOut++ = '"';
+    while( *zIn ){
+      if( *zIn=='"' ) *zOut++ = '"';
+      *zOut++ = *(zIn++);
+    }
+    *zOut++ = '"';
+    p->nBuf = (int)((u8 *)zOut - p->aBuf);
+  }
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is
+** called. Otherwse, it appends the serialized version of the value stored
+** in column iCol of the row that SQL statement pStmt currently points
+** to to the buffer.
+*/
+static void sessionAppendCol(
+  SessionBuffer *p,               /* Buffer to append to */
+  sqlite3_stmt *pStmt,            /* Handle pointing to row containing value */
+  int iCol,                       /* Column to read value from */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  if( *pRc==SQLITE_OK ){
+    int eType = sqlite3_column_type(pStmt, iCol);
+    sessionAppendByte(p, (u8)eType, pRc);
+    if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+      sqlite3_int64 i;
+      u8 aBuf[8];
+      if( eType==SQLITE_INTEGER ){
+        i = sqlite3_column_int64(pStmt, iCol);
+      }else{
+        double r = sqlite3_column_double(pStmt, iCol);
+        memcpy(&i, &r, 8);
+      }
+      sessionPutI64(aBuf, i);
+      sessionAppendBlob(p, aBuf, 8, pRc);
+    }
+    if( eType==SQLITE_BLOB || eType==SQLITE_TEXT ){
+      u8 *z;
+      int nByte;
+      if( eType==SQLITE_BLOB ){
+        z = (u8 *)sqlite3_column_blob(pStmt, iCol);
+      }else{
+        z = (u8 *)sqlite3_column_text(pStmt, iCol);
+      }
+      nByte = sqlite3_column_bytes(pStmt, iCol);
+      if( z || (eType==SQLITE_BLOB && nByte==0) ){
+        sessionAppendVarint(p, nByte, pRc);
+        sessionAppendBlob(p, z, nByte, pRc);
+      }else{
+        *pRc = SQLITE_NOMEM;
+      }
+    }
+  }
+}
+
+/*
+**
+** This function appends an update change to the buffer (see the comments 
+** under "CHANGESET FORMAT" at the top of the file). An update change 
+** consists of:
+**
+**   1 byte:  SQLITE_UPDATE (0x17)
+**   n bytes: old.* record (see RECORD FORMAT)
+**   m bytes: new.* record (see RECORD FORMAT)
+**
+** The SessionChange object passed as the third argument contains the
+** values that were stored in the row when the session began (the old.*
+** values). The statement handle passed as the second argument points
+** at the current version of the row (the new.* values).
+**
+** If all of the old.* values are equal to their corresponding new.* value
+** (i.e. nothing has changed), then no data at all is appended to the buffer.
+**
+** Otherwise, the old.* record contains all primary key values and the 
+** original values of any fields that have been modified. The new.* record 
+** contains the new values of only those fields that have been modified.
+*/ 
+static int sessionAppendUpdate(
+  SessionBuffer *pBuf,            /* Buffer to append to */
+  int bPatchset,                  /* True for "patchset", 0 for "changeset" */
+  sqlite3_stmt *pStmt,            /* Statement handle pointing at new row */
+  SessionChange *p,               /* Object containing old values */
+  u8 *abPK                        /* Boolean array - true for PK columns */
+){
+  int rc = SQLITE_OK;
+  SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */
+  int bNoop = 1;                /* Set to zero if any values are modified */
+  int nRewind = pBuf->nBuf;     /* Set to zero if any values are modified */
+  int i;                        /* Used to iterate through columns */
+  u8 *pCsr = p->aRecord;        /* Used to iterate through old.* values */
+
+  sessionAppendByte(pBuf, SQLITE_UPDATE, &rc);
+  sessionAppendByte(pBuf, p->bIndirect, &rc);
+  for(i=0; i<sqlite3_column_count(pStmt); i++){
+    int bChanged = 0;
+    int nAdvance;
+    int eType = *pCsr;
+    switch( eType ){
+      case SQLITE_NULL:
+        nAdvance = 1;
+        if( sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
+          bChanged = 1;
+        }
+        break;
+
+      case SQLITE_FLOAT:
+      case SQLITE_INTEGER: {
+        nAdvance = 9;
+        if( eType==sqlite3_column_type(pStmt, i) ){
+          sqlite3_int64 iVal = sessionGetI64(&pCsr[1]);
+          if( eType==SQLITE_INTEGER ){
+            if( iVal==sqlite3_column_int64(pStmt, i) ) break;
+          }else{
+            double dVal;
+            memcpy(&dVal, &iVal, 8);
+            if( dVal==sqlite3_column_double(pStmt, i) ) break;
+          }
+        }
+        bChanged = 1;
+        break;
+      }
+
+      default: {
+        int nByte;
+        int nHdr = 1 + sessionVarintGet(&pCsr[1], &nByte);
+        assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );
+        nAdvance = nHdr + nByte;
+        if( eType==sqlite3_column_type(pStmt, i) 
+         && nByte==sqlite3_column_bytes(pStmt, i) 
+         && 0==memcmp(&pCsr[nHdr], sqlite3_column_blob(pStmt, i), nByte)
+        ){
+          break;
+        }
+        bChanged = 1;
+      }
+    }
+
+    /* If at least one field has been modified, this is not a no-op. */
+    if( bChanged ) bNoop = 0;
+
+    /* Add a field to the old.* record. This is omitted if this modules is
+    ** currently generating a patchset. */
+    if( bPatchset==0 ){
+      if( bChanged || abPK[i] ){
+        sessionAppendBlob(pBuf, pCsr, nAdvance, &rc);
+      }else{
+        sessionAppendByte(pBuf, 0, &rc);
+      }
+    }
+
+    /* Add a field to the new.* record. Or the only record if currently
+    ** generating a patchset.  */
+    if( bChanged || (bPatchset && abPK[i]) ){
+      sessionAppendCol(&buf2, pStmt, i, &rc);
+    }else{
+      sessionAppendByte(&buf2, 0, &rc);
+    }
+
+    pCsr += nAdvance;
+  }
+
+  if( bNoop ){
+    pBuf->nBuf = nRewind;
+  }else{
+    sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, &rc);
+  }
+  sqlite3_free(buf2.aBuf);
+
+  return rc;
+}
+
+/*
+** Append a DELETE change to the buffer passed as the first argument. Use
+** the changeset format if argument bPatchset is zero, or the patchset
+** format otherwise.
+*/
+static int sessionAppendDelete(
+  SessionBuffer *pBuf,            /* Buffer to append to */
+  int bPatchset,                  /* True for "patchset", 0 for "changeset" */
+  SessionChange *p,               /* Object containing old values */
+  int nCol,                       /* Number of columns in table */
+  u8 *abPK                        /* Boolean array - true for PK columns */
+){
+  int rc = SQLITE_OK;
+
+  sessionAppendByte(pBuf, SQLITE_DELETE, &rc);
+  sessionAppendByte(pBuf, p->bIndirect, &rc);
+
+  if( bPatchset==0 ){
+    sessionAppendBlob(pBuf, p->aRecord, p->nRecord, &rc);
+  }else{
+    int i;
+    u8 *a = p->aRecord;
+    for(i=0; i<nCol; i++){
+      u8 *pStart = a;
+      int eType = *a++;
+
+      switch( eType ){
+        case 0:
+        case SQLITE_NULL:
+          assert( abPK[i]==0 );
+          break;
+
+        case SQLITE_FLOAT:
+        case SQLITE_INTEGER:
+          a += 8;
+          break;
+
+        default: {
+          int n;
+          a += sessionVarintGet(a, &n);
+          a += n;
+          break;
+        }
+      }
+      if( abPK[i] ){
+        sessionAppendBlob(pBuf, pStart, (int)(a-pStart), &rc);
+      }
+    }
+    assert( (a - p->aRecord)==p->nRecord );
+  }
+
+  return rc;
+}
+
+/*
+** Formulate and prepare a SELECT statement to retrieve a row from table
+** zTab in database zDb based on its primary key. i.e.
+**
+**   SELECT * FROM zDb.zTab WHERE pk1 = ? AND pk2 = ? AND ...
+*/
+static int sessionSelectStmt(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Database name */
+  const char *zTab,               /* Table name */
+  int nCol,                       /* Number of columns in table */
+  const char **azCol,             /* Names of table columns */
+  u8 *abPK,                       /* PRIMARY KEY  array */
+  sqlite3_stmt **ppStmt           /* OUT: Prepared SELECT statement */
+){
+  int rc = SQLITE_OK;
+  int i;
+  const char *zSep = "";
+  SessionBuffer buf = {0, 0, 0};
+
+  sessionAppendStr(&buf, "SELECT * FROM ", &rc);
+  sessionAppendIdent(&buf, zDb, &rc);
+  sessionAppendStr(&buf, ".", &rc);
+  sessionAppendIdent(&buf, zTab, &rc);
+  sessionAppendStr(&buf, " WHERE ", &rc);
+  for(i=0; i<nCol; i++){
+    if( abPK[i] ){
+      sessionAppendStr(&buf, zSep, &rc);
+      sessionAppendIdent(&buf, azCol[i], &rc);
+      sessionAppendStr(&buf, " = ?", &rc);
+      sessionAppendInteger(&buf, i+1, &rc);
+      zSep = " AND ";
+    }
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, ppStmt, 0);
+  }
+  sqlite3_free(buf.aBuf);
+  return rc;
+}
+
+/*
+** Bind the PRIMARY KEY values from the change passed in argument pChange
+** to the SELECT statement passed as the first argument. The SELECT statement
+** is as prepared by function sessionSelectStmt().
+**
+** Return SQLITE_OK if all PK values are successfully bound, or an SQLite
+** error code (e.g. SQLITE_NOMEM) otherwise.
+*/
+static int sessionSelectBind(
+  sqlite3_stmt *pSelect,          /* SELECT from sessionSelectStmt() */
+  int nCol,                       /* Number of columns in table */
+  u8 *abPK,                       /* PRIMARY KEY array */
+  SessionChange *pChange          /* Change structure */
+){
+  int i;
+  int rc = SQLITE_OK;
+  u8 *a = pChange->aRecord;
+
+  for(i=0; i<nCol && rc==SQLITE_OK; i++){
+    int eType = *a++;
+
+    switch( eType ){
+      case 0:
+      case SQLITE_NULL:
+        assert( abPK[i]==0 );
+        break;
+
+      case SQLITE_INTEGER: {
+        if( abPK[i] ){
+          i64 iVal = sessionGetI64(a);
+          rc = sqlite3_bind_int64(pSelect, i+1, iVal);
+        }
+        a += 8;
+        break;
+      }
+
+      case SQLITE_FLOAT: {
+        if( abPK[i] ){
+          double rVal;
+          i64 iVal = sessionGetI64(a);
+          memcpy(&rVal, &iVal, 8);
+          rc = sqlite3_bind_double(pSelect, i+1, rVal);
+        }
+        a += 8;
+        break;
+      }
+
+      case SQLITE_TEXT: {
+        int n;
+        a += sessionVarintGet(a, &n);
+        if( abPK[i] ){
+          rc = sqlite3_bind_text(pSelect, i+1, (char *)a, n, SQLITE_TRANSIENT);
+        }
+        a += n;
+        break;
+      }
+
+      default: {
+        int n;
+        assert( eType==SQLITE_BLOB );
+        a += sessionVarintGet(a, &n);
+        if( abPK[i] ){
+          rc = sqlite3_bind_blob(pSelect, i+1, a, n, SQLITE_TRANSIENT);
+        }
+        a += n;
+        break;
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** This function is a no-op if *pRc is set to other than SQLITE_OK when it
+** is called. Otherwise, append a serialized table header (part of the binary 
+** changeset format) to buffer *pBuf. If an error occurs, set *pRc to an
+** SQLite error code before returning.
+*/
+static void sessionAppendTableHdr(
+  SessionBuffer *pBuf,            /* Append header to this buffer */
+  int bPatchset,                  /* Use the patchset format if true */
+  SessionTable *pTab,             /* Table object to append header for */
+  int *pRc                        /* IN/OUT: Error code */
+){
+  /* Write a table header */
+  sessionAppendByte(pBuf, (bPatchset ? 'P' : 'T'), pRc);
+  sessionAppendVarint(pBuf, pTab->nCol, pRc);
+  sessionAppendBlob(pBuf, pTab->abPK, pTab->nCol, pRc);
+  sessionAppendBlob(pBuf, (u8 *)pTab->zName, (int)strlen(pTab->zName)+1, pRc);
+}
+
+/*
+** Generate either a changeset (if argument bPatchset is zero) or a patchset
+** (if it is non-zero) based on the current contents of the session object
+** passed as the first argument.
+**
+** If no error occurs, SQLITE_OK is returned and the new changeset/patchset
+** stored in output variables *pnChangeset and *ppChangeset. Or, if an error
+** occurs, an SQLite error code is returned and both output variables set 
+** to 0.
+*/
+static int sessionGenerateChangeset(
+  sqlite3_session *pSession,      /* Session object */
+  int bPatchset,                  /* True for patchset, false for changeset */
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut,                     /* First argument for xOutput */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+){
+  sqlite3 *db = pSession->db;     /* Source database handle */
+  SessionTable *pTab;             /* Used to iterate through attached tables */
+  SessionBuffer buf = {0,0,0};    /* Buffer in which to accumlate changeset */
+  int rc;                         /* Return code */
+
+  assert( xOutput==0 || (pnChangeset==0 && ppChangeset==0 ) );
+
+  /* Zero the output variables in case an error occurs. If this session
+  ** object is already in the error state (sqlite3_session.rc != SQLITE_OK),
+  ** this call will be a no-op.  */
+  if( xOutput==0 ){
+    *pnChangeset = 0;
+    *ppChangeset = 0;
+  }
+
+  if( pSession->rc ) return pSession->rc;
+  rc = sqlite3_exec(pSession->db, "SAVEPOINT changeset", 0, 0, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  sqlite3_mutex_enter(sqlite3_db_mutex(db));
+
+  for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
+    if( pTab->nEntry ){
+      const char *zName = pTab->zName;
+      int nCol;                   /* Number of columns in table */
+      u8 *abPK;                   /* Primary key array */
+      const char **azCol = 0;     /* Table columns */
+      int i;                      /* Used to iterate through hash buckets */
+      sqlite3_stmt *pSel = 0;     /* SELECT statement to query table pTab */
+      int nRewind = buf.nBuf;     /* Initial size of write buffer */
+      int nNoop;                  /* Size of buffer after writing tbl header */
+
+      /* Check the table schema is still Ok. */
+      rc = sessionTableInfo(db, pSession->zDb, zName, &nCol, 0, &azCol, &abPK);
+      if( !rc && (pTab->nCol!=nCol || memcmp(abPK, pTab->abPK, nCol)) ){
+        rc = SQLITE_SCHEMA;
+      }
+
+      /* Write a table header */
+      sessionAppendTableHdr(&buf, bPatchset, pTab, &rc);
+
+      /* Build and compile a statement to execute: */
+      if( rc==SQLITE_OK ){
+        rc = sessionSelectStmt(
+            db, pSession->zDb, zName, nCol, azCol, abPK, &pSel);
+      }
+
+      nNoop = buf.nBuf;
+      for(i=0; i<pTab->nChange && rc==SQLITE_OK; i++){
+        SessionChange *p;         /* Used to iterate through changes */
+
+        for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){
+          rc = sessionSelectBind(pSel, nCol, abPK, p);
+          if( rc!=SQLITE_OK ) continue;
+          if( sqlite3_step(pSel)==SQLITE_ROW ){
+            if( p->op==SQLITE_INSERT ){
+              int iCol;
+              sessionAppendByte(&buf, SQLITE_INSERT, &rc);
+              sessionAppendByte(&buf, p->bIndirect, &rc);
+              for(iCol=0; iCol<nCol; iCol++){
+                sessionAppendCol(&buf, pSel, iCol, &rc);
+              }
+            }else{
+              rc = sessionAppendUpdate(&buf, bPatchset, pSel, p, abPK);
+            }
+          }else if( p->op!=SQLITE_INSERT ){
+            rc = sessionAppendDelete(&buf, bPatchset, p, nCol, abPK);
+          }
+          if( rc==SQLITE_OK ){
+            rc = sqlite3_reset(pSel);
+          }
+
+          /* If the buffer is now larger than SESSIONS_STRM_CHUNK_SIZE, pass
+          ** its contents to the xOutput() callback. */
+          if( xOutput 
+           && rc==SQLITE_OK 
+           && buf.nBuf>nNoop 
+           && buf.nBuf>SESSIONS_STRM_CHUNK_SIZE 
+          ){
+            rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf);
+            nNoop = -1;
+            buf.nBuf = 0;
+          }
+
+        }
+      }
+
+      sqlite3_finalize(pSel);
+      if( buf.nBuf==nNoop ){
+        buf.nBuf = nRewind;
+      }
+      sqlite3_free((char*)azCol);  /* cast works around VC++ bug */
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    if( xOutput==0 ){
+      *pnChangeset = buf.nBuf;
+      *ppChangeset = buf.aBuf;
+      buf.aBuf = 0;
+    }else if( buf.nBuf>0 ){
+      rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf);
+    }
+  }
+
+  sqlite3_free(buf.aBuf);
+  sqlite3_exec(db, "RELEASE changeset", 0, 0, 0);
+  sqlite3_mutex_leave(sqlite3_db_mutex(db));
+  return rc;
+}
+
+/*
+** Obtain a changeset object containing all changes recorded by the 
+** session object passed as the first argument.
+**
+** It is the responsibility of the caller to eventually free the buffer 
+** using sqlite3_free().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_changeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+){
+  return sessionGenerateChangeset(pSession, 0, 0, 0, pnChangeset, ppChangeset);
+}
+
+/*
+** Streaming version of sqlite3session_changeset().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_changeset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+){
+  return sessionGenerateChangeset(pSession, 0, xOutput, pOut, 0, 0);
+}
+
+/*
+** Streaming version of sqlite3session_patchset().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_patchset_strm(
+  sqlite3_session *pSession,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+){
+  return sessionGenerateChangeset(pSession, 1, xOutput, pOut, 0, 0);
+}
+
+/*
+** Obtain a patchset object containing all changes recorded by the 
+** session object passed as the first argument.
+**
+** It is the responsibility of the caller to eventually free the buffer 
+** using sqlite3_free().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_patchset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnPatchset,                /* OUT: Size of buffer at *ppChangeset */
+  void **ppPatchset               /* OUT: Buffer containing changeset */
+){
+  return sessionGenerateChangeset(pSession, 1, 0, 0, pnPatchset, ppPatchset);
+}
+
+/*
+** Enable or disable the session object passed as the first argument.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_enable(sqlite3_session *pSession, int bEnable){
+  int ret;
+  sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
+  if( bEnable>=0 ){
+    pSession->bEnable = bEnable;
+  }
+  ret = pSession->bEnable;
+  sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
+  return ret;
+}
+
+/*
+** Enable or disable the session object passed as the first argument.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_indirect(sqlite3_session *pSession, int bIndirect){
+  int ret;
+  sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
+  if( bIndirect>=0 ){
+    pSession->bIndirect = bIndirect;
+  }
+  ret = pSession->bIndirect;
+  sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
+  return ret;
+}
+
+/*
+** Return true if there have been no changes to monitored tables recorded
+** by the session object passed as the only argument.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3session_isempty(sqlite3_session *pSession){
+  int ret = 0;
+  SessionTable *pTab;
+
+  sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));
+  for(pTab=pSession->pTable; pTab && ret==0; pTab=pTab->pNext){
+    ret = (pTab->nEntry>0);
+  }
+  sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));
+
+  return (ret==0);
+}
+
+/*
+** Do the work for either sqlite3changeset_start() or start_strm().
+*/
+static int sessionChangesetStart(
+  sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn,
+  int nChangeset,                 /* Size of buffer pChangeset in bytes */
+  void *pChangeset                /* Pointer to buffer containing changeset */
+){
+  sqlite3_changeset_iter *pRet;   /* Iterator to return */
+  int nByte;                      /* Number of bytes to allocate for iterator */
+
+  assert( xInput==0 || (pChangeset==0 && nChangeset==0) );
+
+  /* Zero the output variable in case an error occurs. */
+  *pp = 0;
+
+  /* Allocate and initialize the iterator structure. */
+  nByte = sizeof(sqlite3_changeset_iter);
+  pRet = (sqlite3_changeset_iter *)sqlite3_malloc(nByte);
+  if( !pRet ) return SQLITE_NOMEM;
+  memset(pRet, 0, sizeof(sqlite3_changeset_iter));
+  pRet->in.aData = (u8 *)pChangeset;
+  pRet->in.nData = nChangeset;
+  pRet->in.xInput = xInput;
+  pRet->in.pIn = pIn;
+  pRet->in.bEof = (xInput ? 0 : 1);
+
+  /* Populate the output variable and return success. */
+  *pp = pRet;
+  return SQLITE_OK;
+}
+
+/*
+** Create an iterator used to iterate through the contents of a changeset.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_start(
+  sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */
+  int nChangeset,                 /* Size of buffer pChangeset in bytes */
+  void *pChangeset                /* Pointer to buffer containing changeset */
+){
+  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset);
+}
+
+/*
+** Streaming version of sqlite3changeset_start().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_start_strm(
+  sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn
+){
+  return sessionChangesetStart(pp, xInput, pIn, 0, 0);
+}
+
+/*
+** If the SessionInput object passed as the only argument is a streaming
+** object and the buffer is full, discard some data to free up space.
+*/
+static void sessionDiscardData(SessionInput *pIn){
+  if( pIn->bEof && pIn->xInput && pIn->iNext>=SESSIONS_STRM_CHUNK_SIZE ){
+    int nMove = pIn->buf.nBuf - pIn->iNext;
+    assert( nMove>=0 );
+    if( nMove>0 ){
+      memmove(pIn->buf.aBuf, &pIn->buf.aBuf[pIn->iNext], nMove);
+    }
+    pIn->buf.nBuf -= pIn->iNext;
+    pIn->iNext = 0;
+    pIn->nData = pIn->buf.nBuf;
+  }
+}
+
+/*
+** Ensure that there are at least nByte bytes available in the buffer. Or,
+** if there are not nByte bytes remaining in the input, that all available
+** data is in the buffer.
+**
+** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.
+*/
+static int sessionInputBuffer(SessionInput *pIn, int nByte){
+  int rc = SQLITE_OK;
+  if( pIn->xInput ){
+    while( !pIn->bEof && (pIn->iNext+nByte)>=pIn->nData && rc==SQLITE_OK ){
+      int nNew = SESSIONS_STRM_CHUNK_SIZE;
+
+      if( pIn->bNoDiscard==0 ) sessionDiscardData(pIn);
+      if( SQLITE_OK==sessionBufferGrow(&pIn->buf, nNew, &rc) ){
+        rc = pIn->xInput(pIn->pIn, &pIn->buf.aBuf[pIn->buf.nBuf], &nNew);
+        if( nNew==0 ){
+          pIn->bEof = 1;
+        }else{
+          pIn->buf.nBuf += nNew;
+        }
+      }
+
+      pIn->aData = pIn->buf.aBuf;
+      pIn->nData = pIn->buf.nBuf;
+    }
+  }
+  return rc;
+}
+
+/*
+** When this function is called, *ppRec points to the start of a record
+** that contains nCol values. This function advances the pointer *ppRec
+** until it points to the byte immediately following that record.
+*/
+static void sessionSkipRecord(
+  u8 **ppRec,                     /* IN/OUT: Record pointer */
+  int nCol                        /* Number of values in record */
+){
+  u8 *aRec = *ppRec;
+  int i;
+  for(i=0; i<nCol; i++){
+    int eType = *aRec++;
+    if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
+      int nByte;
+      aRec += sessionVarintGet((u8*)aRec, &nByte);
+      aRec += nByte;
+    }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+      aRec += 8;
+    }
+  }
+
+  *ppRec = aRec;
+}
+
+/*
+** This function sets the value of the sqlite3_value object passed as the
+** first argument to a copy of the string or blob held in the aData[] 
+** buffer. SQLITE_OK is returned if successful, or SQLITE_NOMEM if an OOM
+** error occurs.
+*/
+static int sessionValueSetStr(
+  sqlite3_value *pVal,            /* Set the value of this object */
+  u8 *aData,                      /* Buffer containing string or blob data */
+  int nData,                      /* Size of buffer aData[] in bytes */
+  u8 enc                          /* String encoding (0 for blobs) */
+){
+  /* In theory this code could just pass SQLITE_TRANSIENT as the final
+  ** argument to sqlite3ValueSetStr() and have the copy created 
+  ** automatically. But doing so makes it difficult to detect any OOM
+  ** error. Hence the code to create the copy externally. */
+  u8 *aCopy = sqlite3_malloc(nData+1);
+  if( aCopy==0 ) return SQLITE_NOMEM;
+  memcpy(aCopy, aData, nData);
+  sqlite3ValueSetStr(pVal, nData, (char*)aCopy, enc, sqlite3_free);
+  return SQLITE_OK;
+}
+
+/*
+** Deserialize a single record from a buffer in memory. See "RECORD FORMAT"
+** for details.
+**
+** When this function is called, *paChange points to the start of the record
+** to deserialize. Assuming no error occurs, *paChange is set to point to
+** one byte after the end of the same record before this function returns.
+** If the argument abPK is NULL, then the record contains nCol values. Or,
+** if abPK is other than NULL, then the record contains only the PK fields
+** (in other words, it is a patchset DELETE record).
+**
+** If successful, each element of the apOut[] array (allocated by the caller)
+** is set to point to an sqlite3_value object containing the value read
+** from the corresponding position in the record. If that value is not
+** included in the record (i.e. because the record is part of an UPDATE change
+** and the field was not modified), the corresponding element of apOut[] is
+** set to NULL.
+**
+** It is the responsibility of the caller to free all sqlite_value structures
+** using sqlite3_free().
+**
+** If an error occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
+** The apOut[] array may have been partially populated in this case.
+*/
+static int sessionReadRecord(
+  SessionInput *pIn,              /* Input data */
+  int nCol,                       /* Number of values in record */
+  u8 *abPK,                       /* Array of primary key flags, or NULL */
+  sqlite3_value **apOut           /* Write values to this array */
+){
+  int i;                          /* Used to iterate through columns */
+  int rc = SQLITE_OK;
+
+  for(i=0; i<nCol && rc==SQLITE_OK; i++){
+    int eType = 0;                /* Type of value (SQLITE_NULL, TEXT etc.) */
+    if( abPK && abPK[i]==0 ) continue;
+    rc = sessionInputBuffer(pIn, 9);
+    if( rc==SQLITE_OK ){
+      eType = pIn->aData[pIn->iNext++];
+    }
+
+    assert( apOut[i]==0 );
+    if( eType ){
+      apOut[i] = sqlite3ValueNew(0);
+      if( !apOut[i] ) rc = SQLITE_NOMEM;
+    }
+
+    if( rc==SQLITE_OK ){
+      u8 *aVal = &pIn->aData[pIn->iNext];
+      if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
+        int nByte;
+        pIn->iNext += sessionVarintGet(aVal, &nByte);
+        rc = sessionInputBuffer(pIn, nByte);
+        if( rc==SQLITE_OK ){
+          u8 enc = (eType==SQLITE_TEXT ? SQLITE_UTF8 : 0);
+          rc = sessionValueSetStr(apOut[i],&pIn->aData[pIn->iNext],nByte,enc);
+        }
+        pIn->iNext += nByte;
+      }
+      if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+        sqlite3_int64 v = sessionGetI64(aVal);
+        if( eType==SQLITE_INTEGER ){
+          sqlite3VdbeMemSetInt64(apOut[i], v);
+        }else{
+          double d;
+          memcpy(&d, &v, 8);
+          sqlite3VdbeMemSetDouble(apOut[i], d);
+        }
+        pIn->iNext += 8;
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** The input pointer currently points to the second byte of a table-header.
+** Specifically, to the following:
+**
+**   + number of columns in table (varint)
+**   + array of PK flags (1 byte per column),
+**   + table name (nul terminated).
+**
+** This function ensures that all of the above is present in the input 
+** buffer (i.e. that it can be accessed without any calls to xInput()).
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.
+** The input pointer is not moved.
+*/
+static int sessionChangesetBufferTblhdr(SessionInput *pIn, int *pnByte){
+  int rc = SQLITE_OK;
+  int nCol = 0;
+  int nRead = 0;
+
+  rc = sessionInputBuffer(pIn, 9);
+  if( rc==SQLITE_OK ){
+    nRead += sessionVarintGet(&pIn->aData[pIn->iNext + nRead], &nCol);
+    rc = sessionInputBuffer(pIn, nRead+nCol+100);
+    nRead += nCol;
+  }
+
+  while( rc==SQLITE_OK ){
+    while( (pIn->iNext + nRead)<pIn->nData && pIn->aData[pIn->iNext + nRead] ){
+      nRead++;
+    }
+    if( (pIn->iNext + nRead)<pIn->nData ) break;
+    rc = sessionInputBuffer(pIn, nRead + 100);
+  }
+  *pnByte = nRead+1;
+  return rc;
+}
+
+/*
+** The input pointer currently points to the first byte of the first field
+** of a record consisting of nCol columns. This function ensures the entire
+** record is buffered. It does not move the input pointer.
+**
+** If successful, SQLITE_OK is returned and *pnByte is set to the size of
+** the record in bytes. Otherwise, an SQLite error code is returned. The
+** final value of *pnByte is undefined in this case.
+*/
+static int sessionChangesetBufferRecord(
+  SessionInput *pIn,              /* Input data */
+  int nCol,                       /* Number of columns in record */
+  int *pnByte                     /* OUT: Size of record in bytes */
+){
+  int rc = SQLITE_OK;
+  int nByte = 0;
+  int i;
+  for(i=0; rc==SQLITE_OK && i<nCol; i++){
+    int eType;
+    rc = sessionInputBuffer(pIn, nByte + 10);
+    if( rc==SQLITE_OK ){
+      eType = pIn->aData[pIn->iNext + nByte++];
+      if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){
+        int n;
+        nByte += sessionVarintGet(&pIn->aData[pIn->iNext+nByte], &n);
+        nByte += n;
+        rc = sessionInputBuffer(pIn, nByte);
+      }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){
+        nByte += 8;
+      }
+    }
+  }
+  *pnByte = nByte;
+  return rc;
+}
+
+/*
+** The input pointer currently points to the second byte of a table-header.
+** Specifically, to the following:
+**
+**   + number of columns in table (varint)
+**   + array of PK flags (1 byte per column),
+**   + table name (nul terminated).
+**
+** This function decodes the table-header and populates the p->nCol, 
+** p->zTab and p->abPK[] variables accordingly. The p->apValue[] array is 
+** also allocated or resized according to the new value of p->nCol. The
+** input pointer is left pointing to the byte following the table header.
+**
+** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code
+** is returned and the final values of the various fields enumerated above
+** are undefined.
+*/
+static int sessionChangesetReadTblhdr(sqlite3_changeset_iter *p){
+  int rc;
+  int nCopy;
+  assert( p->rc==SQLITE_OK );
+
+  rc = sessionChangesetBufferTblhdr(&p->in, &nCopy);
+  if( rc==SQLITE_OK ){
+    int nByte;
+    int nVarint;
+    nVarint = sessionVarintGet(&p->in.aData[p->in.iNext], &p->nCol);
+    nCopy -= nVarint;
+    p->in.iNext += nVarint;
+    nByte = p->nCol * sizeof(sqlite3_value*) * 2 + nCopy;
+    p->tblhdr.nBuf = 0;
+    sessionBufferGrow(&p->tblhdr, nByte, &rc);
+  }
+
+  if( rc==SQLITE_OK ){
+    int iPK = sizeof(sqlite3_value*)*p->nCol*2;
+    memset(p->tblhdr.aBuf, 0, iPK);
+    memcpy(&p->tblhdr.aBuf[iPK], &p->in.aData[p->in.iNext], nCopy);
+    p->in.iNext += nCopy;
+  }
+
+  p->apValue = (sqlite3_value**)p->tblhdr.aBuf;
+  p->abPK = (u8*)&p->apValue[p->nCol*2];
+  p->zTab = (char*)&p->abPK[p->nCol];
+  return (p->rc = rc);
+}
+
+/*
+** Advance the changeset iterator to the next change.
+**
+** If both paRec and pnRec are NULL, then this function works like the public
+** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the
+** sqlite3changeset_new() and old() APIs may be used to query for values.
+**
+** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change
+** record is written to *paRec before returning and the number of bytes in
+** the record to *pnRec.
+**
+** Either way, this function returns SQLITE_ROW if the iterator is 
+** successfully advanced to the next change in the changeset, an SQLite 
+** error code if an error occurs, or SQLITE_DONE if there are no further 
+** changes in the changeset.
+*/
+static int sessionChangesetNext(
+  sqlite3_changeset_iter *p,      /* Changeset iterator */
+  u8 **paRec,                     /* If non-NULL, store record pointer here */
+  int *pnRec                      /* If non-NULL, store size of record here */
+){
+  int i;
+  u8 op;
+
+  assert( (paRec==0 && pnRec==0) || (paRec && pnRec) );
+
+  /* If the iterator is in the error-state, return immediately. */
+  if( p->rc!=SQLITE_OK ) return p->rc;
+
+  /* Free the current contents of p->apValue[], if any. */
+  if( p->apValue ){
+    for(i=0; i<p->nCol*2; i++){
+      sqlite3ValueFree(p->apValue[i]);
+    }
+    memset(p->apValue, 0, sizeof(sqlite3_value*)*p->nCol*2);
+  }
+
+  /* Make sure the buffer contains at least 10 bytes of input data, or all
+  ** remaining data if there are less than 10 bytes available. This is
+  ** sufficient either for the 'T' or 'P' byte and the varint that follows
+  ** it, or for the two single byte values otherwise. */
+  p->rc = sessionInputBuffer(&p->in, 2);
+  if( p->rc!=SQLITE_OK ) return p->rc;
+
+  /* If the iterator is already at the end of the changeset, return DONE. */
+  if( p->in.iNext>=p->in.nData ){
+    return SQLITE_DONE;
+  }
+
+  sessionDiscardData(&p->in);
+  p->in.iCurrent = p->in.iNext;
+
+  op = p->in.aData[p->in.iNext++];
+  if( op=='T' || op=='P' ){
+    p->bPatchset = (op=='P');
+    if( sessionChangesetReadTblhdr(p) ) return p->rc;
+    if( (p->rc = sessionInputBuffer(&p->in, 2)) ) return p->rc;
+    p->in.iCurrent = p->in.iNext;
+    op = p->in.aData[p->in.iNext++];
+  }
+
+  p->op = op;
+  p->bIndirect = p->in.aData[p->in.iNext++];
+  if( p->op!=SQLITE_UPDATE && p->op!=SQLITE_DELETE && p->op!=SQLITE_INSERT ){
+    return (p->rc = SQLITE_CORRUPT_BKPT);
+  }
+
+  if( paRec ){ 
+    int nVal;                     /* Number of values to buffer */
+    if( p->bPatchset==0 && op==SQLITE_UPDATE ){
+      nVal = p->nCol * 2;
+    }else if( p->bPatchset && op==SQLITE_DELETE ){
+      nVal = 0;
+      for(i=0; i<p->nCol; i++) if( p->abPK[i] ) nVal++;
+    }else{
+      nVal = p->nCol;
+    }
+    p->rc = sessionChangesetBufferRecord(&p->in, nVal, pnRec);
+    if( p->rc!=SQLITE_OK ) return p->rc;
+    *paRec = &p->in.aData[p->in.iNext];
+    p->in.iNext += *pnRec;
+  }else{
+
+    /* If this is an UPDATE or DELETE, read the old.* record. */
+    if( p->op!=SQLITE_INSERT && (p->bPatchset==0 || p->op==SQLITE_DELETE) ){
+      u8 *abPK = p->bPatchset ? p->abPK : 0;
+      p->rc = sessionReadRecord(&p->in, p->nCol, abPK, p->apValue);
+      if( p->rc!=SQLITE_OK ) return p->rc;
+    }
+
+    /* If this is an INSERT or UPDATE, read the new.* record. */
+    if( p->op!=SQLITE_DELETE ){
+      p->rc = sessionReadRecord(&p->in, p->nCol, 0, &p->apValue[p->nCol]);
+      if( p->rc!=SQLITE_OK ) return p->rc;
+    }
+
+    if( p->bPatchset && p->op==SQLITE_UPDATE ){
+      /* If this is an UPDATE that is part of a patchset, then all PK and
+      ** modified fields are present in the new.* record. The old.* record
+      ** is currently completely empty. This block shifts the PK fields from
+      ** new.* to old.*, to accommodate the code that reads these arrays.  */
+      for(i=0; i<p->nCol; i++){
+        assert( p->apValue[i]==0 );
+        assert( p->abPK[i]==0 || p->apValue[i+p->nCol] );
+        if( p->abPK[i] ){
+          p->apValue[i] = p->apValue[i+p->nCol];
+          p->apValue[i+p->nCol] = 0;
+        }
+      }
+    }
+  }
+
+  return SQLITE_ROW;
+}
+
+/*
+** Advance an iterator created by sqlite3changeset_start() to the next
+** change in the changeset. This function may return SQLITE_ROW, SQLITE_DONE
+** or SQLITE_CORRUPT.
+**
+** This function may not be called on iterators passed to a conflict handler
+** callback by changeset_apply().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_next(sqlite3_changeset_iter *p){
+  return sessionChangesetNext(p, 0, 0);
+}
+
+/*
+** The following function extracts information on the current change
+** from a changeset iterator. It may only be called after changeset_next()
+** has returned SQLITE_ROW.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_op(
+  sqlite3_changeset_iter *pIter,  /* Iterator handle */
+  const char **pzTab,             /* OUT: Pointer to table name */
+  int *pnCol,                     /* OUT: Number of columns in table */
+  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
+  int *pbIndirect                 /* OUT: True if change is indirect */
+){
+  *pOp = pIter->op;
+  *pnCol = pIter->nCol;
+  *pzTab = pIter->zTab;
+  if( pbIndirect ) *pbIndirect = pIter->bIndirect;
+  return SQLITE_OK;
+}
+
+/*
+** Return information regarding the PRIMARY KEY and number of columns in
+** the database table affected by the change that pIter currently points
+** to. This function may only be called after changeset_next() returns
+** SQLITE_ROW.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_pk(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
+  int *pnCol                      /* OUT: Number of entries in output array */
+){
+  *pabPK = pIter->abPK;
+  if( pnCol ) *pnCol = pIter->nCol;
+  return SQLITE_OK;
+}
+
+/*
+** This function may only be called while the iterator is pointing to an
+** SQLITE_UPDATE or SQLITE_DELETE change (see sqlite3changeset_op()).
+** Otherwise, SQLITE_MISUSE is returned.
+**
+** It sets *ppValue to point to an sqlite3_value structure containing the
+** iVal'th value in the old.* record. Or, if that particular value is not
+** included in the record (because the change is an UPDATE and the field
+** was not modified and is not a PK column), set *ppValue to NULL.
+**
+** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is
+** not modified. Otherwise, SQLITE_OK.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_old(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Index of old.* value to retrieve */
+  sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */
+){
+  if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_DELETE ){
+    return SQLITE_MISUSE;
+  }
+  if( iVal<0 || iVal>=pIter->nCol ){
+    return SQLITE_RANGE;
+  }
+  *ppValue = pIter->apValue[iVal];
+  return SQLITE_OK;
+}
+
+/*
+** This function may only be called while the iterator is pointing to an
+** SQLITE_UPDATE or SQLITE_INSERT change (see sqlite3changeset_op()).
+** Otherwise, SQLITE_MISUSE is returned.
+**
+** It sets *ppValue to point to an sqlite3_value structure containing the
+** iVal'th value in the new.* record. Or, if that particular value is not
+** included in the record (because the change is an UPDATE and the field
+** was not modified), set *ppValue to NULL.
+**
+** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is
+** not modified. Otherwise, SQLITE_OK.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_new(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Index of new.* value to retrieve */
+  sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */
+){
+  if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_INSERT ){
+    return SQLITE_MISUSE;
+  }
+  if( iVal<0 || iVal>=pIter->nCol ){
+    return SQLITE_RANGE;
+  }
+  *ppValue = pIter->apValue[pIter->nCol+iVal];
+  return SQLITE_OK;
+}
+
+/*
+** The following two macros are used internally. They are similar to the
+** sqlite3changeset_new() and sqlite3changeset_old() functions, except that
+** they omit all error checking and return a pointer to the requested value.
+*/
+#define sessionChangesetNew(pIter, iVal) (pIter)->apValue[(pIter)->nCol+(iVal)]
+#define sessionChangesetOld(pIter, iVal) (pIter)->apValue[(iVal)]
+
+/*
+** This function may only be called with a changeset iterator that has been
+** passed to an SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT 
+** conflict-handler function. Otherwise, SQLITE_MISUSE is returned.
+**
+** If successful, *ppValue is set to point to an sqlite3_value structure
+** containing the iVal'th value of the conflicting record.
+**
+** If value iVal is out-of-range or some other error occurs, an SQLite error
+** code is returned. Otherwise, SQLITE_OK.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_conflict(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Index of conflict record value to fetch */
+  sqlite3_value **ppValue         /* OUT: Value from conflicting row */
+){
+  if( !pIter->pConflict ){
+    return SQLITE_MISUSE;
+  }
+  if( iVal<0 || iVal>=sqlite3_column_count(pIter->pConflict) ){
+    return SQLITE_RANGE;
+  }
+  *ppValue = sqlite3_column_value(pIter->pConflict, iVal);
+  return SQLITE_OK;
+}
+
+/*
+** This function may only be called with an iterator passed to an
+** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
+** it sets the output variable to the total number of known foreign key
+** violations in the destination database and returns SQLITE_OK.
+**
+** In all other cases this function returns SQLITE_MISUSE.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_fk_conflicts(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int *pnOut                      /* OUT: Number of FK violations */
+){
+  if( pIter->pConflict || pIter->apValue ){
+    return SQLITE_MISUSE;
+  }
+  *pnOut = pIter->nCol;
+  return SQLITE_OK;
+}
+
+
+/*
+** Finalize an iterator allocated with sqlite3changeset_start().
+**
+** This function may not be called on iterators passed to a conflict handler
+** callback by changeset_apply().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_finalize(sqlite3_changeset_iter *p){
+  int rc = SQLITE_OK;
+  if( p ){
+    int i;                        /* Used to iterate through p->apValue[] */
+    rc = p->rc;
+    if( p->apValue ){
+      for(i=0; i<p->nCol*2; i++) sqlite3ValueFree(p->apValue[i]);
+    }
+    sqlite3_free(p->tblhdr.aBuf);
+    sqlite3_free(p->in.buf.aBuf);
+    sqlite3_free(p);
+  }
+  return rc;
+}
+
+static int sessionChangesetInvert(
+  SessionInput *pInput,           /* Input changeset */
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut,
+  int *pnInverted,                /* OUT: Number of bytes in output changeset */
+  void **ppInverted               /* OUT: Inverse of pChangeset */
+){
+  int rc = SQLITE_OK;             /* Return value */
+  SessionBuffer sOut;             /* Output buffer */
+  int nCol = 0;                   /* Number of cols in current table */
+  u8 *abPK = 0;                   /* PK array for current table */
+  sqlite3_value **apVal = 0;      /* Space for values for UPDATE inversion */
+  SessionBuffer sPK = {0, 0, 0};  /* PK array for current table */
+
+  /* Initialize the output buffer */
+  memset(&sOut, 0, sizeof(SessionBuffer));
+
+  /* Zero the output variables in case an error occurs. */
+  if( ppInverted ){
+    *ppInverted = 0;
+    *pnInverted = 0;
+  }
+
+  while( 1 ){
+    u8 eType;
+
+    /* Test for EOF. */
+    if( (rc = sessionInputBuffer(pInput, 2)) ) goto finished_invert;
+    if( pInput->iNext>=pInput->nData ) break;
+    eType = pInput->aData[pInput->iNext];
+
+    switch( eType ){
+      case 'T': {
+        /* A 'table' record consists of:
+        **
+        **   * A constant 'T' character,
+        **   * Number of columns in said table (a varint),
+        **   * An array of nCol bytes (sPK),
+        **   * A nul-terminated table name.
+        */
+        int nByte;
+        int nVar;
+        pInput->iNext++;
+        if( (rc = sessionChangesetBufferTblhdr(pInput, &nByte)) ){
+          goto finished_invert;
+        }
+        nVar = sessionVarintGet(&pInput->aData[pInput->iNext], &nCol);
+        sPK.nBuf = 0;
+        sessionAppendBlob(&sPK, &pInput->aData[pInput->iNext+nVar], nCol, &rc);
+        sessionAppendByte(&sOut, eType, &rc);
+        sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc);
+        if( rc ) goto finished_invert;
+
+        pInput->iNext += nByte;
+        sqlite3_free(apVal);
+        apVal = 0;
+        abPK = sPK.aBuf;
+        break;
+      }
+
+      case SQLITE_INSERT:
+      case SQLITE_DELETE: {
+        int nByte;
+        int bIndirect = pInput->aData[pInput->iNext+1];
+        int eType2 = (eType==SQLITE_DELETE ? SQLITE_INSERT : SQLITE_DELETE);
+        pInput->iNext += 2;
+        assert( rc==SQLITE_OK );
+        rc = sessionChangesetBufferRecord(pInput, nCol, &nByte);
+        sessionAppendByte(&sOut, eType2, &rc);
+        sessionAppendByte(&sOut, bIndirect, &rc);
+        sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc);
+        pInput->iNext += nByte;
+        if( rc ) goto finished_invert;
+        break;
+      }
+
+      case SQLITE_UPDATE: {
+        int iCol;
+
+        if( 0==apVal ){
+          apVal = (sqlite3_value **)sqlite3_malloc(sizeof(apVal[0])*nCol*2);
+          if( 0==apVal ){
+            rc = SQLITE_NOMEM;
+            goto finished_invert;
+          }
+          memset(apVal, 0, sizeof(apVal[0])*nCol*2);
+        }
+
+        /* Write the header for the new UPDATE change. Same as the original. */
+        sessionAppendByte(&sOut, eType, &rc);
+        sessionAppendByte(&sOut, pInput->aData[pInput->iNext+1], &rc);
+
+        /* Read the old.* and new.* records for the update change. */
+        pInput->iNext += 2;
+        rc = sessionReadRecord(pInput, nCol, 0, &apVal[0]);
+        if( rc==SQLITE_OK ){
+          rc = sessionReadRecord(pInput, nCol, 0, &apVal[nCol]);
+        }
+
+        /* Write the new old.* record. Consists of the PK columns from the
+        ** original old.* record, and the other values from the original
+        ** new.* record. */
+        for(iCol=0; iCol<nCol; iCol++){
+          sqlite3_value *pVal = apVal[iCol + (abPK[iCol] ? 0 : nCol)];
+          sessionAppendValue(&sOut, pVal, &rc);
+        }
+
+        /* Write the new new.* record. Consists of a copy of all values
+        ** from the original old.* record, except for the PK columns, which
+        ** are set to "undefined". */
+        for(iCol=0; iCol<nCol; iCol++){
+          sqlite3_value *pVal = (abPK[iCol] ? 0 : apVal[iCol]);
+          sessionAppendValue(&sOut, pVal, &rc);
+        }
+
+        for(iCol=0; iCol<nCol*2; iCol++){
+          sqlite3ValueFree(apVal[iCol]);
+        }
+        memset(apVal, 0, sizeof(apVal[0])*nCol*2);
+        if( rc!=SQLITE_OK ){
+          goto finished_invert;
+        }
+
+        break;
+      }
+
+      default:
+        rc = SQLITE_CORRUPT_BKPT;
+        goto finished_invert;
+    }
+
+    assert( rc==SQLITE_OK );
+    if( xOutput && sOut.nBuf>=SESSIONS_STRM_CHUNK_SIZE ){
+      rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);
+      sOut.nBuf = 0;
+      if( rc!=SQLITE_OK ) goto finished_invert;
+    }
+  }
+
+  assert( rc==SQLITE_OK );
+  if( pnInverted ){
+    *pnInverted = sOut.nBuf;
+    *ppInverted = sOut.aBuf;
+    sOut.aBuf = 0;
+  }else if( sOut.nBuf>0 ){
+    rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);
+  }
+
+ finished_invert:
+  sqlite3_free(sOut.aBuf);
+  sqlite3_free(apVal);
+  sqlite3_free(sPK.aBuf);
+  return rc;
+}
+
+
+/*
+** Invert a changeset object.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_invert(
+  int nChangeset,                 /* Number of bytes in input */
+  const void *pChangeset,         /* Input changeset */
+  int *pnInverted,                /* OUT: Number of bytes in output changeset */
+  void **ppInverted               /* OUT: Inverse of pChangeset */
+){
+  SessionInput sInput;
+
+  /* Set up the input stream */
+  memset(&sInput, 0, sizeof(SessionInput));
+  sInput.nData = nChangeset;
+  sInput.aData = (u8*)pChangeset;
+
+  return sessionChangesetInvert(&sInput, 0, 0, pnInverted, ppInverted);
+}
+
+/*
+** Streaming version of sqlite3changeset_invert().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_invert_strm(
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+){
+  SessionInput sInput;
+  int rc;
+
+  /* Set up the input stream */
+  memset(&sInput, 0, sizeof(SessionInput));
+  sInput.xInput = xInput;
+  sInput.pIn = pIn;
+
+  rc = sessionChangesetInvert(&sInput, xOutput, pOut, 0, 0);
+  sqlite3_free(sInput.buf.aBuf);
+  return rc;
+}
+
+typedef struct SessionApplyCtx SessionApplyCtx;
+struct SessionApplyCtx {
+  sqlite3 *db;
+  sqlite3_stmt *pDelete;          /* DELETE statement */
+  sqlite3_stmt *pUpdate;          /* UPDATE statement */
+  sqlite3_stmt *pInsert;          /* INSERT statement */
+  sqlite3_stmt *pSelect;          /* SELECT statement */
+  int nCol;                       /* Size of azCol[] and abPK[] arrays */
+  const char **azCol;             /* Array of column names */
+  u8 *abPK;                       /* Boolean array - true if column is in PK */
+
+  int bDeferConstraints;          /* True to defer constraints */
+  SessionBuffer constraints;      /* Deferred constraints are stored here */
+};
+
+/*
+** Formulate a statement to DELETE a row from database db. Assuming a table
+** structure like this:
+**
+**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
+**
+** The DELETE statement looks like this:
+**
+**     DELETE FROM x WHERE a = :1 AND c = :3 AND (:5 OR b IS :2 AND d IS :4)
+**
+** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require
+** matching b and d values, or 1 otherwise. The second case comes up if the
+** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE.
+**
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left
+** pointing to the prepared version of the SQL statement.
+*/
+static int sessionDeleteRow(
+  sqlite3 *db,                    /* Database handle */
+  const char *zTab,               /* Table name */
+  SessionApplyCtx *p              /* Session changeset-apply context */
+){
+  int i;
+  const char *zSep = "";
+  int rc = SQLITE_OK;
+  SessionBuffer buf = {0, 0, 0};
+  int nPk = 0;
+
+  sessionAppendStr(&buf, "DELETE FROM ", &rc);
+  sessionAppendIdent(&buf, zTab, &rc);
+  sessionAppendStr(&buf, " WHERE ", &rc);
+
+  for(i=0; i<p->nCol; i++){
+    if( p->abPK[i] ){
+      nPk++;
+      sessionAppendStr(&buf, zSep, &rc);
+      sessionAppendIdent(&buf, p->azCol[i], &rc);
+      sessionAppendStr(&buf, " = ?", &rc);
+      sessionAppendInteger(&buf, i+1, &rc);
+      zSep = " AND ";
+    }
+  }
+
+  if( nPk<p->nCol ){
+    sessionAppendStr(&buf, " AND (?", &rc);
+    sessionAppendInteger(&buf, p->nCol+1, &rc);
+    sessionAppendStr(&buf, " OR ", &rc);
+
+    zSep = "";
+    for(i=0; i<p->nCol; i++){
+      if( !p->abPK[i] ){
+        sessionAppendStr(&buf, zSep, &rc);
+        sessionAppendIdent(&buf, p->azCol[i], &rc);
+        sessionAppendStr(&buf, " IS ?", &rc);
+        sessionAppendInteger(&buf, i+1, &rc);
+        zSep = "AND ";
+      }
+    }
+    sessionAppendStr(&buf, ")", &rc);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pDelete, 0);
+  }
+  sqlite3_free(buf.aBuf);
+
+  return rc;
+}
+
+/*
+** Formulate and prepare a statement to UPDATE a row from database db. 
+** Assuming a table structure like this:
+**
+**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
+**
+** The UPDATE statement looks like this:
+**
+**     UPDATE x SET
+**     a = CASE WHEN ?2  THEN ?3  ELSE a END,
+**     b = CASE WHEN ?5  THEN ?6  ELSE b END,
+**     c = CASE WHEN ?8  THEN ?9  ELSE c END,
+**     d = CASE WHEN ?11 THEN ?12 ELSE d END
+**     WHERE a = ?1 AND c = ?7 AND (?13 OR 
+**       (?5==0 OR b IS ?4) AND (?11==0 OR d IS ?10) AND
+**     )
+**
+** For each column in the table, there are three variables to bind:
+**
+**     ?(i*3+1)    The old.* value of the column, if any.
+**     ?(i*3+2)    A boolean flag indicating that the value is being modified.
+**     ?(i*3+3)    The new.* value of the column, if any.
+**
+** Also, a boolean flag that, if set to true, causes the statement to update
+** a row even if the non-PK values do not match. This is required if the
+** conflict-handler is invoked with CHANGESET_DATA and returns
+** CHANGESET_REPLACE. This is variable "?(nCol*3+1)".
+**
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pUpdate is left
+** pointing to the prepared version of the SQL statement.
+*/
+static int sessionUpdateRow(
+  sqlite3 *db,                    /* Database handle */
+  const char *zTab,               /* Table name */
+  SessionApplyCtx *p              /* Session changeset-apply context */
+){
+  int rc = SQLITE_OK;
+  int i;
+  const char *zSep = "";
+  SessionBuffer buf = {0, 0, 0};
+
+  /* Append "UPDATE tbl SET " */
+  sessionAppendStr(&buf, "UPDATE ", &rc);
+  sessionAppendIdent(&buf, zTab, &rc);
+  sessionAppendStr(&buf, " SET ", &rc);
+
+  /* Append the assignments */
+  for(i=0; i<p->nCol; i++){
+    sessionAppendStr(&buf, zSep, &rc);
+    sessionAppendIdent(&buf, p->azCol[i], &rc);
+    sessionAppendStr(&buf, " = CASE WHEN ?", &rc);
+    sessionAppendInteger(&buf, i*3+2, &rc);
+    sessionAppendStr(&buf, " THEN ?", &rc);
+    sessionAppendInteger(&buf, i*3+3, &rc);
+    sessionAppendStr(&buf, " ELSE ", &rc);
+    sessionAppendIdent(&buf, p->azCol[i], &rc);
+    sessionAppendStr(&buf, " END", &rc);
+    zSep = ", ";
+  }
+
+  /* Append the PK part of the WHERE clause */
+  sessionAppendStr(&buf, " WHERE ", &rc);
+  for(i=0; i<p->nCol; i++){
+    if( p->abPK[i] ){
+      sessionAppendIdent(&buf, p->azCol[i], &rc);
+      sessionAppendStr(&buf, " = ?", &rc);
+      sessionAppendInteger(&buf, i*3+1, &rc);
+      sessionAppendStr(&buf, " AND ", &rc);
+    }
+  }
+
+  /* Append the non-PK part of the WHERE clause */
+  sessionAppendStr(&buf, " (?", &rc);
+  sessionAppendInteger(&buf, p->nCol*3+1, &rc);
+  sessionAppendStr(&buf, " OR 1", &rc);
+  for(i=0; i<p->nCol; i++){
+    if( !p->abPK[i] ){
+      sessionAppendStr(&buf, " AND (?", &rc);
+      sessionAppendInteger(&buf, i*3+2, &rc);
+      sessionAppendStr(&buf, "=0 OR ", &rc);
+      sessionAppendIdent(&buf, p->azCol[i], &rc);
+      sessionAppendStr(&buf, " IS ?", &rc);
+      sessionAppendInteger(&buf, i*3+1, &rc);
+      sessionAppendStr(&buf, ")", &rc);
+    }
+  }
+  sessionAppendStr(&buf, ")", &rc);
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pUpdate, 0);
+  }
+  sqlite3_free(buf.aBuf);
+
+  return rc;
+}
+
+/*
+** Formulate and prepare an SQL statement to query table zTab by primary
+** key. Assuming the following table structure:
+**
+**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
+**
+** The SELECT statement looks like this:
+**
+**     SELECT * FROM x WHERE a = ?1 AND c = ?3
+**
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pSelect is left
+** pointing to the prepared version of the SQL statement.
+*/
+static int sessionSelectRow(
+  sqlite3 *db,                    /* Database handle */
+  const char *zTab,               /* Table name */
+  SessionApplyCtx *p              /* Session changeset-apply context */
+){
+  return sessionSelectStmt(
+      db, "main", zTab, p->nCol, p->azCol, p->abPK, &p->pSelect);
+}
+
+/*
+** Formulate and prepare an INSERT statement to add a record to table zTab.
+** For example:
+**
+**     INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...);
+**
+** If successful, SQLITE_OK is returned and SessionApplyCtx.pInsert is left
+** pointing to the prepared version of the SQL statement.
+*/
+static int sessionInsertRow(
+  sqlite3 *db,                    /* Database handle */
+  const char *zTab,               /* Table name */
+  SessionApplyCtx *p              /* Session changeset-apply context */
+){
+  int rc = SQLITE_OK;
+  int i;
+  SessionBuffer buf = {0, 0, 0};
+
+  sessionAppendStr(&buf, "INSERT INTO main.", &rc);
+  sessionAppendIdent(&buf, zTab, &rc);
+  sessionAppendStr(&buf, " VALUES(?", &rc);
+  for(i=1; i<p->nCol; i++){
+    sessionAppendStr(&buf, ", ?", &rc);
+  }
+  sessionAppendStr(&buf, ")", &rc);
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0);
+  }
+  sqlite3_free(buf.aBuf);
+  return rc;
+}
+
+/*
+** A wrapper around sqlite3_bind_value() that detects an extra problem. 
+** See comments in the body of this function for details.
+*/
+static int sessionBindValue(
+  sqlite3_stmt *pStmt,            /* Statement to bind value to */
+  int i,                          /* Parameter number to bind to */
+  sqlite3_value *pVal             /* Value to bind */
+){
+  int eType = sqlite3_value_type(pVal);
+  /* COVERAGE: The (pVal->z==0) branch is never true using current versions
+  ** of SQLite. If a malloc fails in an sqlite3_value_xxx() function, either
+  ** the (pVal->z) variable remains as it was or the type of the value is
+  ** set to SQLITE_NULL.  */
+  if( (eType==SQLITE_TEXT || eType==SQLITE_BLOB) && pVal->z==0 ){
+    /* This condition occurs when an earlier OOM in a call to
+    ** sqlite3_value_text() or sqlite3_value_blob() (perhaps from within
+    ** a conflict-handler) has zeroed the pVal->z pointer. Return NOMEM. */
+    return SQLITE_NOMEM;
+  }
+  return sqlite3_bind_value(pStmt, i, pVal);
+}
+
+/*
+** Iterator pIter must point to an SQLITE_INSERT entry. This function 
+** transfers new.* values from the current iterator entry to statement
+** pStmt. The table being inserted into has nCol columns.
+**
+** New.* value $i from the iterator is bound to variable ($i+1) of 
+** statement pStmt. If parameter abPK is NULL, all values from 0 to (nCol-1)
+** are transfered to the statement. Otherwise, if abPK is not NULL, it points
+** to an array nCol elements in size. In this case only those values for 
+** which abPK[$i] is true are read from the iterator and bound to the 
+** statement.
+**
+** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK.
+*/
+static int sessionBindRow(
+  sqlite3_changeset_iter *pIter,  /* Iterator to read values from */
+  int(*xValue)(sqlite3_changeset_iter *, int, sqlite3_value **),
+  int nCol,                       /* Number of columns */
+  u8 *abPK,                       /* If not NULL, bind only if true */
+  sqlite3_stmt *pStmt             /* Bind values to this statement */
+){
+  int i;
+  int rc = SQLITE_OK;
+
+  /* Neither sqlite3changeset_old or sqlite3changeset_new can fail if the
+  ** argument iterator points to a suitable entry. Make sure that xValue 
+  ** is one of these to guarantee that it is safe to ignore the return 
+  ** in the code below. */
+  assert( xValue==sqlite3changeset_old || xValue==sqlite3changeset_new );
+
+  for(i=0; rc==SQLITE_OK && i<nCol; i++){
+    if( !abPK || abPK[i] ){
+      sqlite3_value *pVal;
+      (void)xValue(pIter, i, &pVal);
+      rc = sessionBindValue(pStmt, i+1, pVal);
+    }
+  }
+  return rc;
+}
+
+/*
+** SQL statement pSelect is as generated by the sessionSelectRow() function.
+** This function binds the primary key values from the change that changeset
+** iterator pIter points to to the SELECT and attempts to seek to the table
+** entry. If a row is found, the SELECT statement left pointing at the row 
+** and SQLITE_ROW is returned. Otherwise, if no row is found and no error
+** has occured, the statement is reset and SQLITE_OK is returned. If an
+** error occurs, the statement is reset and an SQLite error code is returned.
+**
+** If this function returns SQLITE_ROW, the caller must eventually reset() 
+** statement pSelect. If any other value is returned, the statement does
+** not require a reset().
+**
+** If the iterator currently points to an INSERT record, bind values from the
+** new.* record to the SELECT statement. Or, if it points to a DELETE or
+** UPDATE, bind values from the old.* record. 
+*/
+static int sessionSeekToRow(
+  sqlite3 *db,                    /* Database handle */
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  u8 *abPK,                       /* Primary key flags array */
+  sqlite3_stmt *pSelect           /* SELECT statement from sessionSelectRow() */
+){
+  int rc;                         /* Return code */
+  int nCol;                       /* Number of columns in table */
+  int op;                         /* Changset operation (SQLITE_UPDATE etc.) */
+  const char *zDummy;             /* Unused */
+
+  sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
+  rc = sessionBindRow(pIter, 
+      op==SQLITE_INSERT ? sqlite3changeset_new : sqlite3changeset_old,
+      nCol, abPK, pSelect
+  );
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_step(pSelect);
+    if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);
+  }
+
+  return rc;
+}
+
+/*
+** Invoke the conflict handler for the change that the changeset iterator
+** currently points to.
+**
+** Argument eType must be either CHANGESET_DATA or CHANGESET_CONFLICT.
+** If argument pbReplace is NULL, then the type of conflict handler invoked
+** depends solely on eType, as follows:
+**
+**    eType value                 Value passed to xConflict
+**    -------------------------------------------------
+**    CHANGESET_DATA              CHANGESET_NOTFOUND
+**    CHANGESET_CONFLICT          CHANGESET_CONSTRAINT
+**
+** Or, if pbReplace is not NULL, then an attempt is made to find an existing
+** record with the same primary key as the record about to be deleted, updated
+** or inserted. If such a record can be found, it is available to the conflict
+** handler as the "conflicting" record. In this case the type of conflict
+** handler invoked is as follows:
+**
+**    eType value         PK Record found?   Value passed to xConflict
+**    ----------------------------------------------------------------
+**    CHANGESET_DATA      Yes                CHANGESET_DATA
+**    CHANGESET_DATA      No                 CHANGESET_NOTFOUND
+**    CHANGESET_CONFLICT  Yes                CHANGESET_CONFLICT
+**    CHANGESET_CONFLICT  No                 CHANGESET_CONSTRAINT
+**
+** If pbReplace is not NULL, and a record with a matching PK is found, and
+** the conflict handler function returns SQLITE_CHANGESET_REPLACE, *pbReplace
+** is set to non-zero before returning SQLITE_OK.
+**
+** If the conflict handler returns SQLITE_CHANGESET_ABORT, SQLITE_ABORT is
+** returned. Or, if the conflict handler returns an invalid value, 
+** SQLITE_MISUSE. If the conflict handler returns SQLITE_CHANGESET_OMIT,
+** this function returns SQLITE_OK.
+*/
+static int sessionConflictHandler(
+  int eType,                      /* Either CHANGESET_DATA or CONFLICT */
+  SessionApplyCtx *p,             /* changeset_apply() context */
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int(*xConflict)(void *, int, sqlite3_changeset_iter*),
+  void *pCtx,                     /* First argument for conflict handler */
+  int *pbReplace                  /* OUT: Set to true if PK row is found */
+){
+  int res = 0;                    /* Value returned by conflict handler */
+  int rc;
+  int nCol;
+  int op;
+  const char *zDummy;
+
+  sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
+
+  assert( eType==SQLITE_CHANGESET_CONFLICT || eType==SQLITE_CHANGESET_DATA );
+  assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT );
+  assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND );
+
+  /* Bind the new.* PRIMARY KEY values to the SELECT statement. */
+  if( pbReplace ){
+    rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);
+  }else{
+    rc = SQLITE_OK;
+  }
+
+  if( rc==SQLITE_ROW ){
+    /* There exists another row with the new.* primary key. */
+    pIter->pConflict = p->pSelect;
+    res = xConflict(pCtx, eType, pIter);
+    pIter->pConflict = 0;
+    rc = sqlite3_reset(p->pSelect);
+  }else if( rc==SQLITE_OK ){
+    if( p->bDeferConstraints && eType==SQLITE_CHANGESET_CONFLICT ){
+      /* Instead of invoking the conflict handler, append the change blob
+      ** to the SessionApplyCtx.constraints buffer. */
+      u8 *aBlob = &pIter->in.aData[pIter->in.iCurrent];
+      int nBlob = pIter->in.iNext - pIter->in.iCurrent;
+      sessionAppendBlob(&p->constraints, aBlob, nBlob, &rc);
+      res = SQLITE_CHANGESET_OMIT;
+    }else{
+      /* No other row with the new.* primary key. */
+      res = xConflict(pCtx, eType+1, pIter);
+      if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    switch( res ){
+      case SQLITE_CHANGESET_REPLACE:
+        assert( pbReplace );
+        *pbReplace = 1;
+        break;
+
+      case SQLITE_CHANGESET_OMIT:
+        break;
+
+      case SQLITE_CHANGESET_ABORT:
+        rc = SQLITE_ABORT;
+        break;
+
+      default:
+        rc = SQLITE_MISUSE;
+        break;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Attempt to apply the change that the iterator passed as the first argument
+** currently points to to the database. If a conflict is encountered, invoke
+** the conflict handler callback.
+**
+** If argument pbRetry is NULL, then ignore any CHANGESET_DATA conflict. If
+** one is encountered, update or delete the row with the matching primary key
+** instead. Or, if pbRetry is not NULL and a CHANGESET_DATA conflict occurs,
+** invoke the conflict handler. If it returns CHANGESET_REPLACE, set *pbRetry
+** to true before returning. In this case the caller will invoke this function
+** again, this time with pbRetry set to NULL.
+**
+** If argument pbReplace is NULL and a CHANGESET_CONFLICT conflict is 
+** encountered invoke the conflict handler with CHANGESET_CONSTRAINT instead.
+** Or, if pbReplace is not NULL, invoke it with CHANGESET_CONFLICT. If such
+** an invocation returns SQLITE_CHANGESET_REPLACE, set *pbReplace to true
+** before retrying. In this case the caller attempts to remove the conflicting
+** row before invoking this function again, this time with pbReplace set 
+** to NULL.
+**
+** If any conflict handler returns SQLITE_CHANGESET_ABORT, this function
+** returns SQLITE_ABORT. Otherwise, if no error occurs, SQLITE_OK is 
+** returned.
+*/
+static int sessionApplyOneOp(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  SessionApplyCtx *p,             /* changeset_apply() context */
+  int(*xConflict)(void *, int, sqlite3_changeset_iter *),
+  void *pCtx,                     /* First argument for the conflict handler */
+  int *pbReplace,                 /* OUT: True to remove PK row and retry */
+  int *pbRetry                    /* OUT: True to retry. */
+){
+  const char *zDummy;
+  int op;
+  int nCol;
+  int rc = SQLITE_OK;
+
+  assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );
+  assert( p->azCol && p->abPK );
+  assert( !pbReplace || *pbReplace==0 );
+
+  sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);
+
+  if( op==SQLITE_DELETE ){
+
+    /* Bind values to the DELETE statement. If conflict handling is required,
+    ** bind values for all columns and set bound variable (nCol+1) to true.
+    ** Or, if conflict handling is not required, bind just the PK column
+    ** values and, if it exists, set (nCol+1) to false. Conflict handling
+    ** is not required if:
+    **
+    **   * this is a patchset, or
+    **   * (pbRetry==0), or
+    **   * all columns of the table are PK columns (in this case there is
+    **     no (nCol+1) variable to bind to).
+    */
+    u8 *abPK = (pIter->bPatchset ? p->abPK : 0);
+    rc = sessionBindRow(pIter, sqlite3changeset_old, nCol, abPK, p->pDelete);
+    if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){
+      rc = sqlite3_bind_int(p->pDelete, nCol+1, (pbRetry==0 || abPK));
+    }
+    if( rc!=SQLITE_OK ) return rc;
+
+    sqlite3_step(p->pDelete);
+    rc = sqlite3_reset(p->pDelete);
+    if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){
+      rc = sessionConflictHandler(
+          SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
+      );
+    }else if( (rc&0xff)==SQLITE_CONSTRAINT ){
+      rc = sessionConflictHandler(
+          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0
+      );
+    }
+
+  }else if( op==SQLITE_UPDATE ){
+    int i;
+
+    /* Bind values to the UPDATE statement. */
+    for(i=0; rc==SQLITE_OK && i<nCol; i++){
+      sqlite3_value *pOld = sessionChangesetOld(pIter, i);
+      sqlite3_value *pNew = sessionChangesetNew(pIter, i);
+
+      sqlite3_bind_int(p->pUpdate, i*3+2, !!pNew);
+      if( pOld ){
+        rc = sessionBindValue(p->pUpdate, i*3+1, pOld);
+      }
+      if( rc==SQLITE_OK && pNew ){
+        rc = sessionBindValue(p->pUpdate, i*3+3, pNew);
+      }
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int(p->pUpdate, nCol*3+1, pbRetry==0 || pIter->bPatchset);
+    }
+    if( rc!=SQLITE_OK ) return rc;
+
+    /* Attempt the UPDATE. In the case of a NOTFOUND or DATA conflict,
+    ** the result will be SQLITE_OK with 0 rows modified. */
+    sqlite3_step(p->pUpdate);
+    rc = sqlite3_reset(p->pUpdate);
+
+    if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){
+      /* A NOTFOUND or DATA error. Search the table to see if it contains
+      ** a row with a matching primary key. If so, this is a DATA conflict.
+      ** Otherwise, if there is no primary key match, it is a NOTFOUND. */
+
+      rc = sessionConflictHandler(
+          SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
+      );
+
+    }else if( (rc&0xff)==SQLITE_CONSTRAINT ){
+      /* This is always a CONSTRAINT conflict. */
+      rc = sessionConflictHandler(
+          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0
+      );
+    }
+
+  }else{
+    assert( op==SQLITE_INSERT );
+    rc = sessionBindRow(pIter, sqlite3changeset_new, nCol, 0, p->pInsert);
+    if( rc!=SQLITE_OK ) return rc;
+
+    sqlite3_step(p->pInsert);
+    rc = sqlite3_reset(p->pInsert);
+    if( (rc&0xff)==SQLITE_CONSTRAINT ){
+      rc = sessionConflictHandler(
+          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace
+      );
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Attempt to apply the change that the iterator passed as the first argument
+** currently points to to the database. If a conflict is encountered, invoke
+** the conflict handler callback.
+**
+** The difference between this function and sessionApplyOne() is that this
+** function handles the case where the conflict-handler is invoked and 
+** returns SQLITE_CHANGESET_REPLACE - indicating that the change should be
+** retried in some manner.
+*/
+static int sessionApplyOneWithRetry(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator to read change from */
+  SessionApplyCtx *pApply,        /* Apply context */
+  int(*xConflict)(void*, int, sqlite3_changeset_iter*),
+  void *pCtx                      /* First argument passed to xConflict */
+){
+  int bReplace = 0;
+  int bRetry = 0;
+  int rc;
+
+  rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, &bReplace, &bRetry);
+  assert( rc==SQLITE_OK || (bRetry==0 && bReplace==0) );
+
+  /* If the bRetry flag is set, the change has not been applied due to an
+  ** SQLITE_CHANGESET_DATA problem (i.e. this is an UPDATE or DELETE and
+  ** a row with the correct PK is present in the db, but one or more other
+  ** fields do not contain the expected values) and the conflict handler 
+  ** returned SQLITE_CHANGESET_REPLACE. In this case retry the operation,
+  ** but pass NULL as the final argument so that sessionApplyOneOp() ignores
+  ** the SQLITE_CHANGESET_DATA problem.  */
+  if( bRetry ){
+    assert( pIter->op==SQLITE_UPDATE || pIter->op==SQLITE_DELETE );
+    rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0);
+  }
+
+  /* If the bReplace flag is set, the change is an INSERT that has not
+  ** been performed because the database already contains a row with the
+  ** specified primary key and the conflict handler returned
+  ** SQLITE_CHANGESET_REPLACE. In this case remove the conflicting row
+  ** before reattempting the INSERT.  */
+  else if( bReplace ){
+    assert( pIter->op==SQLITE_INSERT );
+    rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0);
+    if( rc==SQLITE_OK ){
+      rc = sessionBindRow(pIter, 
+          sqlite3changeset_new, pApply->nCol, pApply->abPK, pApply->pDelete);
+      sqlite3_bind_int(pApply->pDelete, pApply->nCol+1, 1);
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3_step(pApply->pDelete);
+      rc = sqlite3_reset(pApply->pDelete);
+    }
+    if( rc==SQLITE_OK ){
+      rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0);
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_exec(db, "RELEASE replace_op", 0, 0, 0);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Retry the changes accumulated in the pApply->constraints buffer.
+*/
+static int sessionRetryConstraints(
+  sqlite3 *db, 
+  int bPatchset,
+  const char *zTab,
+  SessionApplyCtx *pApply,
+  int(*xConflict)(void*, int, sqlite3_changeset_iter*),
+  void *pCtx                      /* First argument passed to xConflict */
+){
+  int rc = SQLITE_OK;
+
+  while( pApply->constraints.nBuf ){
+    sqlite3_changeset_iter *pIter2 = 0;
+    SessionBuffer cons = pApply->constraints;
+    memset(&pApply->constraints, 0, sizeof(SessionBuffer));
+
+    rc = sessionChangesetStart(&pIter2, 0, 0, cons.nBuf, cons.aBuf);
+    if( rc==SQLITE_OK ){
+      int nByte = 2*pApply->nCol*sizeof(sqlite3_value*);
+      int rc2;
+      pIter2->bPatchset = bPatchset;
+      pIter2->zTab = (char*)zTab;
+      pIter2->nCol = pApply->nCol;
+      pIter2->abPK = pApply->abPK;
+      sessionBufferGrow(&pIter2->tblhdr, nByte, &rc);
+      pIter2->apValue = (sqlite3_value**)pIter2->tblhdr.aBuf;
+      if( rc==SQLITE_OK ) memset(pIter2->apValue, 0, nByte);
+
+      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter2) ){
+        rc = sessionApplyOneWithRetry(db, pIter2, pApply, xConflict, pCtx);
+      }
+
+      rc2 = sqlite3changeset_finalize(pIter2);
+      if( rc==SQLITE_OK ) rc = rc2;
+    }
+    assert( pApply->bDeferConstraints || pApply->constraints.nBuf==0 );
+
+    sqlite3_free(cons.aBuf);
+    if( rc!=SQLITE_OK ) break;
+    if( pApply->constraints.nBuf>=cons.nBuf ){
+      /* No progress was made on the last round. */
+      pApply->bDeferConstraints = 0;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Argument pIter is a changeset iterator that has been initialized, but
+** not yet passed to sqlite3changeset_next(). This function applies the 
+** changeset to the main database attached to handle "db". The supplied
+** conflict handler callback is invoked to resolve any conflicts encountered
+** while applying the change.
+*/
+static int sessionChangesetApply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  sqlite3_changeset_iter *pIter,  /* Changeset to apply */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of fifth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+){
+  int schemaMismatch = 0;
+  int rc;                         /* Return code */
+  const char *zTab = 0;           /* Name of current table */
+  int nTab = 0;                   /* Result of sqlite3Strlen30(zTab) */
+  SessionApplyCtx sApply;         /* changeset_apply() context object */
+  int bPatchset;
+
+  assert( xConflict!=0 );
+
+  pIter->in.bNoDiscard = 1;
+  memset(&sApply, 0, sizeof(sApply));
+  sqlite3_mutex_enter(sqlite3_db_mutex(db));
+  rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0);
+  }
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter) ){
+    int nCol;
+    int op;
+    const char *zNew;
+    
+    sqlite3changeset_op(pIter, &zNew, &nCol, &op, 0);
+
+    if( zTab==0 || sqlite3_strnicmp(zNew, zTab, nTab+1) ){
+      u8 *abPK;
+
+      rc = sessionRetryConstraints(
+          db, pIter->bPatchset, zTab, &sApply, xConflict, pCtx
+      );
+      if( rc!=SQLITE_OK ) break;
+
+      sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */
+      sqlite3_finalize(sApply.pDelete);
+      sqlite3_finalize(sApply.pUpdate); 
+      sqlite3_finalize(sApply.pInsert);
+      sqlite3_finalize(sApply.pSelect);
+      memset(&sApply, 0, sizeof(sApply));
+      sApply.db = db;
+      sApply.bDeferConstraints = 1;
+
+      /* If an xFilter() callback was specified, invoke it now. If the 
+      ** xFilter callback returns zero, skip this table. If it returns
+      ** non-zero, proceed. */
+      schemaMismatch = (xFilter && (0==xFilter(pCtx, zNew)));
+      if( schemaMismatch ){
+        zTab = sqlite3_mprintf("%s", zNew);
+        if( zTab==0 ){
+          rc = SQLITE_NOMEM;
+          break;
+        }
+        nTab = (int)strlen(zTab);
+        sApply.azCol = (const char **)zTab;
+      }else{
+        sqlite3changeset_pk(pIter, &abPK, 0);
+        rc = sessionTableInfo(
+            db, "main", zNew, &sApply.nCol, &zTab, &sApply.azCol, &sApply.abPK
+        );
+        if( rc!=SQLITE_OK ) break;
+  
+        if( sApply.nCol==0 ){
+          schemaMismatch = 1;
+          sqlite3_log(SQLITE_SCHEMA, 
+              "sqlite3changeset_apply(): no such table: %s", zTab
+          );
+        }
+        else if( sApply.nCol!=nCol ){
+          schemaMismatch = 1;
+          sqlite3_log(SQLITE_SCHEMA, 
+              "sqlite3changeset_apply(): table %s has %d columns, expected %d", 
+              zTab, sApply.nCol, nCol
+          );
+        }
+        else if( memcmp(sApply.abPK, abPK, nCol)!=0 ){
+          schemaMismatch = 1;
+          sqlite3_log(SQLITE_SCHEMA, "sqlite3changeset_apply(): "
+              "primary key mismatch for table %s", zTab
+          );
+        }
+        else if( 
+            (rc = sessionSelectRow(db, zTab, &sApply))
+         || (rc = sessionUpdateRow(db, zTab, &sApply))
+         || (rc = sessionDeleteRow(db, zTab, &sApply))
+         || (rc = sessionInsertRow(db, zTab, &sApply))
+        ){
+          break;
+        }
+        nTab = sqlite3Strlen30(zTab);
+      }
+    }
+
+    /* If there is a schema mismatch on the current table, proceed to the
+    ** next change. A log message has already been issued. */
+    if( schemaMismatch ) continue;
+
+    rc = sessionApplyOneWithRetry(db, pIter, &sApply, xConflict, pCtx);
+  }
+
+  bPatchset = pIter->bPatchset;
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changeset_finalize(pIter);
+  }else{
+    sqlite3changeset_finalize(pIter);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = sessionRetryConstraints(db, bPatchset, zTab, &sApply, xConflict, pCtx);
+  }
+
+  if( rc==SQLITE_OK ){
+    int nFk, notUsed;
+    sqlite3_db_status(db, SQLITE_DBSTATUS_DEFERRED_FKS, &nFk, &notUsed, 0);
+    if( nFk!=0 ){
+      int res = SQLITE_CHANGESET_ABORT;
+      sqlite3_changeset_iter sIter;
+      memset(&sIter, 0, sizeof(sIter));
+      sIter.nCol = nFk;
+      res = xConflict(pCtx, SQLITE_CHANGESET_FOREIGN_KEY, &sIter);
+      if( res!=SQLITE_CHANGESET_OMIT ){
+        rc = SQLITE_CONSTRAINT;
+      }
+    }
+  }
+  sqlite3_exec(db, "PRAGMA defer_foreign_keys = 0", 0, 0, 0);
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
+  }else{
+    sqlite3_exec(db, "ROLLBACK TO changeset_apply", 0, 0, 0);
+    sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);
+  }
+
+  sqlite3_finalize(sApply.pInsert);
+  sqlite3_finalize(sApply.pDelete);
+  sqlite3_finalize(sApply.pUpdate);
+  sqlite3_finalize(sApply.pSelect);
+  sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */
+  sqlite3_free((char*)sApply.constraints.aBuf);
+  sqlite3_mutex_leave(sqlite3_db_mutex(db));
+  return rc;
+}
+
+/*
+** Apply the changeset passed via pChangeset/nChangeset to the main database
+** attached to handle "db". Invoke the supplied conflict handler callback
+** to resolve any conflicts encountered while applying the change.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_apply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of fifth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+){
+  sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  
+  int rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset);
+  if( rc==SQLITE_OK ){
+    rc = sessionChangesetApply(db, pIter, xFilter, xConflict, pCtx);
+  }
+  return rc;
+}
+
+/*
+** Apply the changeset passed via xInput/pIn to the main database
+** attached to handle "db". Invoke the supplied conflict handler callback
+** to resolve any conflicts encountered while applying the change.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_apply_strm(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
+  void *pIn,                                          /* First arg for xInput */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+){
+  sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  
+  int rc = sqlite3changeset_start_strm(&pIter, xInput, pIn);
+  if( rc==SQLITE_OK ){
+    rc = sessionChangesetApply(db, pIter, xFilter, xConflict, pCtx);
+  }
+  return rc;
+}
+
+/*
+** sqlite3_changegroup handle.
+*/
+struct sqlite3_changegroup {
+  int rc;                         /* Error code */
+  int bPatch;                     /* True to accumulate patchsets */
+  SessionTable *pList;            /* List of tables in current patch */
+};
+
+/*
+** This function is called to merge two changes to the same row together as
+** part of an sqlite3changeset_concat() operation. A new change object is
+** allocated and a pointer to it stored in *ppNew.
+*/
+static int sessionChangeMerge(
+  SessionTable *pTab,             /* Table structure */
+  int bPatchset,                  /* True for patchsets */
+  SessionChange *pExist,          /* Existing change */
+  int op2,                        /* Second change operation */
+  int bIndirect,                  /* True if second change is indirect */
+  u8 *aRec,                       /* Second change record */
+  int nRec,                       /* Number of bytes in aRec */
+  SessionChange **ppNew           /* OUT: Merged change */
+){
+  SessionChange *pNew = 0;
+
+  if( !pExist ){
+    pNew = (SessionChange *)sqlite3_malloc(sizeof(SessionChange) + nRec);
+    if( !pNew ){
+      return SQLITE_NOMEM;
+    }
+    memset(pNew, 0, sizeof(SessionChange));
+    pNew->op = op2;
+    pNew->bIndirect = bIndirect;
+    pNew->nRecord = nRec;
+    pNew->aRecord = (u8*)&pNew[1];
+    memcpy(pNew->aRecord, aRec, nRec);
+  }else{
+    int op1 = pExist->op;
+
+    /* 
+    **   op1=INSERT, op2=INSERT      ->      Unsupported. Discard op2.
+    **   op1=INSERT, op2=UPDATE      ->      INSERT.
+    **   op1=INSERT, op2=DELETE      ->      (none)
+    **
+    **   op1=UPDATE, op2=INSERT      ->      Unsupported. Discard op2.
+    **   op1=UPDATE, op2=UPDATE      ->      UPDATE.
+    **   op1=UPDATE, op2=DELETE      ->      DELETE.
+    **
+    **   op1=DELETE, op2=INSERT      ->      UPDATE.
+    **   op1=DELETE, op2=UPDATE      ->      Unsupported. Discard op2.
+    **   op1=DELETE, op2=DELETE      ->      Unsupported. Discard op2.
+    */   
+    if( (op1==SQLITE_INSERT && op2==SQLITE_INSERT)
+     || (op1==SQLITE_UPDATE && op2==SQLITE_INSERT)
+     || (op1==SQLITE_DELETE && op2==SQLITE_UPDATE)
+     || (op1==SQLITE_DELETE && op2==SQLITE_DELETE)
+    ){
+      pNew = pExist;
+    }else if( op1==SQLITE_INSERT && op2==SQLITE_DELETE ){
+      sqlite3_free(pExist);
+      assert( pNew==0 );
+    }else{
+      u8 *aExist = pExist->aRecord;
+      int nByte;
+      u8 *aCsr;
+
+      /* Allocate a new SessionChange object. Ensure that the aRecord[]
+      ** buffer of the new object is large enough to hold any record that
+      ** may be generated by combining the input records.  */
+      nByte = sizeof(SessionChange) + pExist->nRecord + nRec;
+      pNew = (SessionChange *)sqlite3_malloc(nByte);
+      if( !pNew ){
+        sqlite3_free(pExist);
+        return SQLITE_NOMEM;
+      }
+      memset(pNew, 0, sizeof(SessionChange));
+      pNew->bIndirect = (bIndirect && pExist->bIndirect);
+      aCsr = pNew->aRecord = (u8 *)&pNew[1];
+
+      if( op1==SQLITE_INSERT ){             /* INSERT + UPDATE */
+        u8 *a1 = aRec;
+        assert( op2==SQLITE_UPDATE );
+        pNew->op = SQLITE_INSERT;
+        if( bPatchset==0 ) sessionSkipRecord(&a1, pTab->nCol);
+        sessionMergeRecord(&aCsr, pTab->nCol, aExist, a1);
+      }else if( op1==SQLITE_DELETE ){       /* DELETE + INSERT */
+        assert( op2==SQLITE_INSERT );
+        pNew->op = SQLITE_UPDATE;
+        if( bPatchset ){
+          memcpy(aCsr, aRec, nRec);
+          aCsr += nRec;
+        }else{
+          if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aExist, 0,aRec,0) ){
+            sqlite3_free(pNew);
+            pNew = 0;
+          }
+        }
+      }else if( op2==SQLITE_UPDATE ){       /* UPDATE + UPDATE */
+        u8 *a1 = aExist;
+        u8 *a2 = aRec;
+        assert( op1==SQLITE_UPDATE );
+        if( bPatchset==0 ){
+          sessionSkipRecord(&a1, pTab->nCol);
+          sessionSkipRecord(&a2, pTab->nCol);
+        }
+        pNew->op = SQLITE_UPDATE;
+        if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aRec, aExist,a1,a2) ){
+          sqlite3_free(pNew);
+          pNew = 0;
+        }
+      }else{                                /* UPDATE + DELETE */
+        assert( op1==SQLITE_UPDATE && op2==SQLITE_DELETE );
+        pNew->op = SQLITE_DELETE;
+        if( bPatchset ){
+          memcpy(aCsr, aRec, nRec);
+          aCsr += nRec;
+        }else{
+          sessionMergeRecord(&aCsr, pTab->nCol, aRec, aExist);
+        }
+      }
+
+      if( pNew ){
+        pNew->nRecord = (int)(aCsr - pNew->aRecord);
+      }
+      sqlite3_free(pExist);
+    }
+  }
+
+  *ppNew = pNew;
+  return SQLITE_OK;
+}
+
+/*
+** Add all changes in the changeset traversed by the iterator passed as
+** the first argument to the changegroup hash tables.
+*/
+static int sessionChangesetToHash(
+  sqlite3_changeset_iter *pIter,   /* Iterator to read from */
+  sqlite3_changegroup *pGrp        /* Changegroup object to add changeset to */
+){
+  u8 *aRec;
+  int nRec;
+  int rc = SQLITE_OK;
+  SessionTable *pTab = 0;
+
+
+  while( SQLITE_ROW==sessionChangesetNext(pIter, &aRec, &nRec) ){
+    const char *zNew;
+    int nCol;
+    int op;
+    int iHash;
+    int bIndirect;
+    SessionChange *pChange;
+    SessionChange *pExist = 0;
+    SessionChange **pp;
+
+    if( pGrp->pList==0 ){
+      pGrp->bPatch = pIter->bPatchset;
+    }else if( pIter->bPatchset!=pGrp->bPatch ){
+      rc = SQLITE_ERROR;
+      break;
+    }
+
+    sqlite3changeset_op(pIter, &zNew, &nCol, &op, &bIndirect);
+    if( !pTab || sqlite3_stricmp(zNew, pTab->zName) ){
+      /* Search the list for a matching table */
+      int nNew = (int)strlen(zNew);
+      u8 *abPK;
+
+      sqlite3changeset_pk(pIter, &abPK, 0);
+      for(pTab = pGrp->pList; pTab; pTab=pTab->pNext){
+        if( 0==sqlite3_strnicmp(pTab->zName, zNew, nNew+1) ) break;
+      }
+      if( !pTab ){
+        SessionTable **ppTab;
+
+        pTab = sqlite3_malloc(sizeof(SessionTable) + nCol + nNew+1);
+        if( !pTab ){
+          rc = SQLITE_NOMEM;
+          break;
+        }
+        memset(pTab, 0, sizeof(SessionTable));
+        pTab->nCol = nCol;
+        pTab->abPK = (u8*)&pTab[1];
+        memcpy(pTab->abPK, abPK, nCol);
+        pTab->zName = (char*)&pTab->abPK[nCol];
+        memcpy(pTab->zName, zNew, nNew+1);
+
+        /* The new object must be linked on to the end of the list, not
+        ** simply added to the start of it. This is to ensure that the
+        ** tables within the output of sqlite3changegroup_output() are in 
+        ** the right order.  */
+        for(ppTab=&pGrp->pList; *ppTab; ppTab=&(*ppTab)->pNext);
+        *ppTab = pTab;
+      }else if( pTab->nCol!=nCol || memcmp(pTab->abPK, abPK, nCol) ){
+        rc = SQLITE_SCHEMA;
+        break;
+      }
+    }
+
+    if( sessionGrowHash(pIter->bPatchset, pTab) ){
+      rc = SQLITE_NOMEM;
+      break;
+    }
+    iHash = sessionChangeHash(
+        pTab, (pIter->bPatchset && op==SQLITE_DELETE), aRec, pTab->nChange
+    );
+
+    /* Search for existing entry. If found, remove it from the hash table. 
+    ** Code below may link it back in.
+    */
+    for(pp=&pTab->apChange[iHash]; *pp; pp=&(*pp)->pNext){
+      int bPkOnly1 = 0;
+      int bPkOnly2 = 0;
+      if( pIter->bPatchset ){
+        bPkOnly1 = (*pp)->op==SQLITE_DELETE;
+        bPkOnly2 = op==SQLITE_DELETE;
+      }
+      if( sessionChangeEqual(pTab, bPkOnly1, (*pp)->aRecord, bPkOnly2, aRec) ){
+        pExist = *pp;
+        *pp = (*pp)->pNext;
+        pTab->nEntry--;
+        break;
+      }
+    }
+
+    rc = sessionChangeMerge(pTab, 
+        pIter->bPatchset, pExist, op, bIndirect, aRec, nRec, &pChange
+    );
+    if( rc ) break;
+    if( pChange ){
+      pChange->pNext = pTab->apChange[iHash];
+      pTab->apChange[iHash] = pChange;
+      pTab->nEntry++;
+    }
+  }
+
+  if( rc==SQLITE_OK ) rc = pIter->rc;
+  return rc;
+}
+
+/*
+** Serialize a changeset (or patchset) based on all changesets (or patchsets)
+** added to the changegroup object passed as the first argument.
+**
+** If xOutput is not NULL, then the changeset/patchset is returned to the
+** user via one or more calls to xOutput, as with the other streaming
+** interfaces. 
+**
+** Or, if xOutput is NULL, then (*ppOut) is populated with a pointer to a
+** buffer containing the output changeset before this function returns. In
+** this case (*pnOut) is set to the size of the output buffer in bytes. It
+** is the responsibility of the caller to free the output buffer using
+** sqlite3_free() when it is no longer required.
+**
+** If successful, SQLITE_OK is returned. Or, if an error occurs, an SQLite
+** error code. If an error occurs and xOutput is NULL, (*ppOut) and (*pnOut)
+** are both set to 0 before returning.
+*/
+static int sessionChangegroupOutput(
+  sqlite3_changegroup *pGrp,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut,
+  int *pnOut,
+  void **ppOut
+){
+  int rc = SQLITE_OK;
+  SessionBuffer buf = {0, 0, 0};
+  SessionTable *pTab;
+  assert( xOutput==0 || (ppOut==0 && pnOut==0) );
+
+  /* Create the serialized output changeset based on the contents of the
+  ** hash tables attached to the SessionTable objects in list p->pList. 
+  */
+  for(pTab=pGrp->pList; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
+    int i;
+    if( pTab->nEntry==0 ) continue;
+
+    sessionAppendTableHdr(&buf, pGrp->bPatch, pTab, &rc);
+    for(i=0; i<pTab->nChange; i++){
+      SessionChange *p;
+      for(p=pTab->apChange[i]; p; p=p->pNext){
+        sessionAppendByte(&buf, p->op, &rc);
+        sessionAppendByte(&buf, p->bIndirect, &rc);
+        sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc);
+      }
+    }
+
+    if( rc==SQLITE_OK && xOutput && buf.nBuf>=SESSIONS_STRM_CHUNK_SIZE ){
+      rc = xOutput(pOut, buf.aBuf, buf.nBuf);
+      buf.nBuf = 0;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    if( xOutput ){
+      if( buf.nBuf>0 ) rc = xOutput(pOut, buf.aBuf, buf.nBuf);
+    }else{
+      *ppOut = buf.aBuf;
+      *pnOut = buf.nBuf;
+      buf.aBuf = 0;
+    }
+  }
+  sqlite3_free(buf.aBuf);
+
+  return rc;
+}
+
+/*
+** Allocate a new, empty, sqlite3_changegroup.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changegroup_new(sqlite3_changegroup **pp){
+  int rc = SQLITE_OK;             /* Return code */
+  sqlite3_changegroup *p;         /* New object */
+  p = (sqlite3_changegroup*)sqlite3_malloc(sizeof(sqlite3_changegroup));
+  if( p==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    memset(p, 0, sizeof(sqlite3_changegroup));
+  }
+  *pp = p;
+  return rc;
+}
+
+/*
+** Add the changeset currently stored in buffer pData, size nData bytes,
+** to changeset-group p.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changegroup_add(sqlite3_changegroup *pGrp, int nData, void *pData){
+  sqlite3_changeset_iter *pIter;  /* Iterator opened on pData/nData */
+  int rc;                         /* Return code */
+
+  rc = sqlite3changeset_start(&pIter, nData, pData);
+  if( rc==SQLITE_OK ){
+    rc = sessionChangesetToHash(pIter, pGrp);
+  }
+  sqlite3changeset_finalize(pIter);
+  return rc;
+}
+
+/*
+** Obtain a buffer containing a changeset representing the concatenation
+** of all changesets added to the group so far.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changegroup_output(
+    sqlite3_changegroup *pGrp,
+    int *pnData,
+    void **ppData
+){
+  return sessionChangegroupOutput(pGrp, 0, 0, pnData, ppData);
+}
+
+/*
+** Streaming versions of changegroup_add().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changegroup_add_strm(
+  sqlite3_changegroup *pGrp,
+  int (*xInput)(void *pIn, void *pData, int *pnData),
+  void *pIn
+){
+  sqlite3_changeset_iter *pIter;  /* Iterator opened on pData/nData */
+  int rc;                         /* Return code */
+
+  rc = sqlite3changeset_start_strm(&pIter, xInput, pIn);
+  if( rc==SQLITE_OK ){
+    rc = sessionChangesetToHash(pIter, pGrp);
+  }
+  sqlite3changeset_finalize(pIter);
+  return rc;
+}
+
+/*
+** Streaming versions of changegroup_output().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changegroup_output_strm(
+  sqlite3_changegroup *pGrp,
+  int (*xOutput)(void *pOut, const void *pData, int nData), 
+  void *pOut
+){
+  return sessionChangegroupOutput(pGrp, xOutput, pOut, 0, 0);
+}
+
+/*
+** Delete a changegroup object.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3changegroup_delete(sqlite3_changegroup *pGrp){
+  if( pGrp ){
+    sessionDeleteTable(pGrp->pList);
+    sqlite3_free(pGrp);
+  }
+}
+
+/* 
+** Combine two changesets together.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_concat(
+  int nLeft,                      /* Number of bytes in lhs input */
+  void *pLeft,                    /* Lhs input changeset */
+  int nRight                      /* Number of bytes in rhs input */,
+  void *pRight,                   /* Rhs input changeset */
+  int *pnOut,                     /* OUT: Number of bytes in output changeset */
+  void **ppOut                    /* OUT: changeset (left <concat> right) */
+){
+  sqlite3_changegroup *pGrp;
+  int rc;
+
+  rc = sqlite3changegroup_new(&pGrp);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_add(pGrp, nLeft, pLeft);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_add(pGrp, nRight, pRight);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
+  }
+  sqlite3changegroup_delete(pGrp);
+
+  return rc;
+}
+
+/*
+** Streaming version of sqlite3changeset_concat().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3changeset_concat_strm(
+  int (*xInputA)(void *pIn, void *pData, int *pnData),
+  void *pInA,
+  int (*xInputB)(void *pIn, void *pData, int *pnData),
+  void *pInB,
+  int (*xOutput)(void *pOut, const void *pData, int nData),
+  void *pOut
+){
+  sqlite3_changegroup *pGrp;
+  int rc;
+
+  rc = sqlite3changegroup_new(&pGrp);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_add_strm(pGrp, xInputA, pInA);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_add_strm(pGrp, xInputB, pInB);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3changegroup_output_strm(pGrp, xOutput, pOut);
+  }
+  sqlite3changegroup_delete(pGrp);
+
+  return rc;
+}
+
+#endif /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */
+
+/************** End of sqlite3session.c **************************************/
+/************** Begin file json1.c *******************************************/
+/*
+** 2015-08-12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements JSON functions.  The interface is
+** modeled after MySQL JSON functions:
+**
+**     https://dev.mysql.com/doc/refman/5.7/en/json.html
+**
+** For the time being, all JSON is stored as pure text.  (We might add
+** a JSONB type in the future which stores a binary encoding of JSON in
+** a BLOB, but there is no support for JSONB in the current implementation.
+** This implementation parses JSON text at 250 MB/s, so it is hard to see
+** how JSONB might improve on that.)
+*/
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1)
+#if !defined(_SQLITEINT_H_)
+/* #include "sqlite3ext.h" */
+#endif
+SQLITE_EXTENSION_INIT1
+/* #include <assert.h> */
+/* #include <string.h> */
+/* #include <stdlib.h> */
+/* #include <stdarg.h> */
+
+/* Mark a function parameter as unused, to suppress nuisance compiler
+** warnings. */
+#ifndef UNUSED_PARAM
+# define UNUSED_PARAM(X)  (void)(X)
+#endif
+
+#ifndef LARGEST_INT64
+# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
+# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
+#endif
+
+/*
+** Versions of isspace(), isalnum() and isdigit() to which it is safe
+** to pass signed char values.
+*/
+#ifdef sqlite3Isdigit
+   /* Use the SQLite core versions if this routine is part of the
+   ** SQLite amalgamation */
+#  define safe_isdigit(x) sqlite3Isdigit(x)
+#  define safe_isalnum(x) sqlite3Isalnum(x)
+#else
+   /* Use the standard library for separate compilation */
+#include <ctype.h>  /* amalgamator: keep */
+#  define safe_isdigit(x) isdigit((unsigned char)(x))
+#  define safe_isalnum(x) isalnum((unsigned char)(x))
+#endif
+
+/*
+** Growing our own isspace() routine this way is twice as fast as
+** the library isspace() function, resulting in a 7% overall performance
+** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).
+*/
+static const char jsonIsSpace[] = {
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
+};
+#define safe_isspace(x) (jsonIsSpace[(unsigned char)x])
+
+#ifndef SQLITE_AMALGAMATION
+  /* Unsigned integer types.  These are already defined in the sqliteInt.h,
+  ** but the definitions need to be repeated for separate compilation. */
+  typedef sqlite3_uint64 u64;
+  typedef unsigned int u32;
+  typedef unsigned char u8;
+#endif
+
+/* Objects */
+typedef struct JsonString JsonString;
+typedef struct JsonNode JsonNode;
+typedef struct JsonParse JsonParse;
+
+/* An instance of this object represents a JSON string
+** under construction.  Really, this is a generic string accumulator
+** that can be and is used to create strings other than JSON.
+*/
+struct JsonString {
+  sqlite3_context *pCtx;   /* Function context - put error messages here */
+  char *zBuf;              /* Append JSON content here */
+  u64 nAlloc;              /* Bytes of storage available in zBuf[] */
+  u64 nUsed;               /* Bytes of zBuf[] currently used */
+  u8 bStatic;              /* True if zBuf is static space */
+  u8 bErr;                 /* True if an error has been encountered */
+  char zSpace[100];        /* Initial static space */
+};
+
+/* JSON type values
+*/
+#define JSON_NULL     0
+#define JSON_TRUE     1
+#define JSON_FALSE    2
+#define JSON_INT      3
+#define JSON_REAL     4
+#define JSON_STRING   5
+#define JSON_ARRAY    6
+#define JSON_OBJECT   7
+
+/* The "subtype" set for JSON values */
+#define JSON_SUBTYPE  74    /* Ascii for "J" */
+
+/*
+** Names of the various JSON types:
+*/
+static const char * const jsonType[] = {
+  "null", "true", "false", "integer", "real", "text", "array", "object"
+};
+
+/* Bit values for the JsonNode.jnFlag field
+*/
+#define JNODE_RAW     0x01         /* Content is raw, not JSON encoded */
+#define JNODE_ESCAPE  0x02         /* Content is text with \ escapes */
+#define JNODE_REMOVE  0x04         /* Do not output */
+#define JNODE_REPLACE 0x08         /* Replace with JsonNode.iVal */
+#define JNODE_APPEND  0x10         /* More ARRAY/OBJECT entries at u.iAppend */
+#define JNODE_LABEL   0x20         /* Is a label of an object */
+
+
+/* A single node of parsed JSON
+*/
+struct JsonNode {
+  u8 eType;              /* One of the JSON_ type values */
+  u8 jnFlags;            /* JNODE flags */
+  u8 iVal;               /* Replacement value when JNODE_REPLACE */
+  u32 n;                 /* Bytes of content, or number of sub-nodes */
+  union {
+    const char *zJContent; /* Content for INT, REAL, and STRING */
+    u32 iAppend;           /* More terms for ARRAY and OBJECT */
+    u32 iKey;              /* Key for ARRAY objects in json_tree() */
+  } u;
+};
+
+/* A completely parsed JSON string
+*/
+struct JsonParse {
+  u32 nNode;         /* Number of slots of aNode[] used */
+  u32 nAlloc;        /* Number of slots of aNode[] allocated */
+  JsonNode *aNode;   /* Array of nodes containing the parse */
+  const char *zJson; /* Original JSON string */
+  u32 *aUp;          /* Index of parent of each node */
+  u8 oom;            /* Set to true if out of memory */
+  u8 nErr;           /* Number of errors seen */
+};
+
+/**************************************************************************
+** Utility routines for dealing with JsonString objects
+**************************************************************************/
+
+/* Set the JsonString object to an empty string
+*/
+static void jsonZero(JsonString *p){
+  p->zBuf = p->zSpace;
+  p->nAlloc = sizeof(p->zSpace);
+  p->nUsed = 0;
+  p->bStatic = 1;
+}
+
+/* Initialize the JsonString object
+*/
+static void jsonInit(JsonString *p, sqlite3_context *pCtx){
+  p->pCtx = pCtx;
+  p->bErr = 0;
+  jsonZero(p);
+}
+
+
+/* Free all allocated memory and reset the JsonString object back to its
+** initial state.
+*/
+static void jsonReset(JsonString *p){
+  if( !p->bStatic ) sqlite3_free(p->zBuf);
+  jsonZero(p);
+}
+
+
+/* Report an out-of-memory (OOM) condition 
+*/
+static void jsonOom(JsonString *p){
+  p->bErr = 1;
+  sqlite3_result_error_nomem(p->pCtx);
+  jsonReset(p);
+}
+
+/* Enlarge pJson->zBuf so that it can hold at least N more bytes.
+** Return zero on success.  Return non-zero on an OOM error
+*/
+static int jsonGrow(JsonString *p, u32 N){
+  u64 nTotal = N<p->nAlloc ? p->nAlloc*2 : p->nAlloc+N+10;
+  char *zNew;
+  if( p->bStatic ){
+    if( p->bErr ) return 1;
+    zNew = sqlite3_malloc64(nTotal);
+    if( zNew==0 ){
+      jsonOom(p);
+      return SQLITE_NOMEM;
+    }
+    memcpy(zNew, p->zBuf, (size_t)p->nUsed);
+    p->zBuf = zNew;
+    p->bStatic = 0;
+  }else{
+    zNew = sqlite3_realloc64(p->zBuf, nTotal);
+    if( zNew==0 ){
+      jsonOom(p);
+      return SQLITE_NOMEM;
+    }
+    p->zBuf = zNew;
+  }
+  p->nAlloc = nTotal;
+  return SQLITE_OK;
+}
+
+/* Append N bytes from zIn onto the end of the JsonString string.
+*/
+static void jsonAppendRaw(JsonString *p, const char *zIn, u32 N){
+  if( (N+p->nUsed >= p->nAlloc) && jsonGrow(p,N)!=0 ) return;
+  memcpy(p->zBuf+p->nUsed, zIn, N);
+  p->nUsed += N;
+}
+
+/* Append formatted text (not to exceed N bytes) to the JsonString.
+*/
+static void jsonPrintf(int N, JsonString *p, const char *zFormat, ...){
+  va_list ap;
+  if( (p->nUsed + N >= p->nAlloc) && jsonGrow(p, N) ) return;
+  va_start(ap, zFormat);
+  sqlite3_vsnprintf(N, p->zBuf+p->nUsed, zFormat, ap);
+  va_end(ap);
+  p->nUsed += (int)strlen(p->zBuf+p->nUsed);
+}
+
+/* Append a single character
+*/
+static void jsonAppendChar(JsonString *p, char c){
+  if( p->nUsed>=p->nAlloc && jsonGrow(p,1)!=0 ) return;
+  p->zBuf[p->nUsed++] = c;
+}
+
+/* Append a comma separator to the output buffer, if the previous
+** character is not '[' or '{'.
+*/
+static void jsonAppendSeparator(JsonString *p){
+  char c;
+  if( p->nUsed==0 ) return;
+  c = p->zBuf[p->nUsed-1];
+  if( c!='[' && c!='{' ) jsonAppendChar(p, ',');
+}
+
+/* Append the N-byte string in zIn to the end of the JsonString string
+** under construction.  Enclose the string in "..." and escape
+** any double-quotes or backslash characters contained within the
+** string.
+*/
+static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
+  u32 i;
+  if( (N+p->nUsed+2 >= p->nAlloc) && jsonGrow(p,N+2)!=0 ) return;
+  p->zBuf[p->nUsed++] = '"';
+  for(i=0; i<N; i++){
+    unsigned char c = ((unsigned const char*)zIn)[i];
+    if( c=='"' || c=='\\' ){
+      json_simple_escape:
+      if( (p->nUsed+N+3-i > p->nAlloc) && jsonGrow(p,N+3-i)!=0 ) return;
+      p->zBuf[p->nUsed++] = '\\';
+    }else if( c<=0x1f ){
+      static const char aSpecial[] = {
+         0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
+         0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0
+      };
+      assert( sizeof(aSpecial)==32 );
+      assert( aSpecial['\b']=='b' );
+      assert( aSpecial['\f']=='f' );
+      assert( aSpecial['\n']=='n' );
+      assert( aSpecial['\r']=='r' );
+      assert( aSpecial['\t']=='t' );
+      if( aSpecial[c] ){
+        c = aSpecial[c];
+        goto json_simple_escape;
+      }
+      if( (p->nUsed+N+7+i > p->nAlloc) && jsonGrow(p,N+7-i)!=0 ) return;
+      p->zBuf[p->nUsed++] = '\\';
+      p->zBuf[p->nUsed++] = 'u';
+      p->zBuf[p->nUsed++] = '0';
+      p->zBuf[p->nUsed++] = '0';
+      p->zBuf[p->nUsed++] = '0' + (c>>4);
+      c = "0123456789abcdef"[c&0xf];
+    }
+    p->zBuf[p->nUsed++] = c;
+  }
+  p->zBuf[p->nUsed++] = '"';
+  assert( p->nUsed<p->nAlloc );
+}
+
+/*
+** Append a function parameter value to the JSON string under 
+** construction.
+*/
+static void jsonAppendValue(
+  JsonString *p,                 /* Append to this JSON string */
+  sqlite3_value *pValue          /* Value to append */
+){
+  switch( sqlite3_value_type(pValue) ){
+    case SQLITE_NULL: {
+      jsonAppendRaw(p, "null", 4);
+      break;
+    }
+    case SQLITE_INTEGER:
+    case SQLITE_FLOAT: {
+      const char *z = (const char*)sqlite3_value_text(pValue);
+      u32 n = (u32)sqlite3_value_bytes(pValue);
+      jsonAppendRaw(p, z, n);
+      break;
+    }
+    case SQLITE_TEXT: {
+      const char *z = (const char*)sqlite3_value_text(pValue);
+      u32 n = (u32)sqlite3_value_bytes(pValue);
+      if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){
+        jsonAppendRaw(p, z, n);
+      }else{
+        jsonAppendString(p, z, n);
+      }
+      break;
+    }
+    default: {
+      if( p->bErr==0 ){
+        sqlite3_result_error(p->pCtx, "JSON cannot hold BLOB values", -1);
+        p->bErr = 2;
+        jsonReset(p);
+      }
+      break;
+    }
+  }
+}
+
+
+/* Make the JSON in p the result of the SQL function.
+*/
+static void jsonResult(JsonString *p){
+  if( p->bErr==0 ){
+    sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed, 
+                          p->bStatic ? SQLITE_TRANSIENT : sqlite3_free,
+                          SQLITE_UTF8);
+    jsonZero(p);
+  }
+  assert( p->bStatic );
+}
+
+/**************************************************************************
+** Utility routines for dealing with JsonNode and JsonParse objects
+**************************************************************************/
+
+/*
+** Return the number of consecutive JsonNode slots need to represent
+** the parsed JSON at pNode.  The minimum answer is 1.  For ARRAY and
+** OBJECT types, the number might be larger.
+**
+** Appended elements are not counted.  The value returned is the number
+** by which the JsonNode counter should increment in order to go to the
+** next peer value.
+*/
+static u32 jsonNodeSize(JsonNode *pNode){
+  return pNode->eType>=JSON_ARRAY ? pNode->n+1 : 1;
+}
+
+/*
+** Reclaim all memory allocated by a JsonParse object.  But do not
+** delete the JsonParse object itself.
+*/
+static void jsonParseReset(JsonParse *pParse){
+  sqlite3_free(pParse->aNode);
+  pParse->aNode = 0;
+  pParse->nNode = 0;
+  pParse->nAlloc = 0;
+  sqlite3_free(pParse->aUp);
+  pParse->aUp = 0;
+}
+
+/*
+** Convert the JsonNode pNode into a pure JSON string and
+** append to pOut.  Subsubstructure is also included.  Return
+** the number of JsonNode objects that are encoded.
+*/
+static void jsonRenderNode(
+  JsonNode *pNode,               /* The node to render */
+  JsonString *pOut,              /* Write JSON here */
+  sqlite3_value **aReplace       /* Replacement values */
+){
+  switch( pNode->eType ){
+    default: {
+      assert( pNode->eType==JSON_NULL );
+      jsonAppendRaw(pOut, "null", 4);
+      break;
+    }
+    case JSON_TRUE: {
+      jsonAppendRaw(pOut, "true", 4);
+      break;
+    }
+    case JSON_FALSE: {
+      jsonAppendRaw(pOut, "false", 5);
+      break;
+    }
+    case JSON_STRING: {
+      if( pNode->jnFlags & JNODE_RAW ){
+        jsonAppendString(pOut, pNode->u.zJContent, pNode->n);
+        break;
+      }
+      /* Fall through into the next case */
+    }
+    case JSON_REAL:
+    case JSON_INT: {
+      jsonAppendRaw(pOut, pNode->u.zJContent, pNode->n);
+      break;
+    }
+    case JSON_ARRAY: {
+      u32 j = 1;
+      jsonAppendChar(pOut, '[');
+      for(;;){
+        while( j<=pNode->n ){
+          if( pNode[j].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ){
+            if( pNode[j].jnFlags & JNODE_REPLACE ){
+              jsonAppendSeparator(pOut);
+              jsonAppendValue(pOut, aReplace[pNode[j].iVal]);
+            }
+          }else{
+            jsonAppendSeparator(pOut);
+            jsonRenderNode(&pNode[j], pOut, aReplace);
+          }
+          j += jsonNodeSize(&pNode[j]);
+        }
+        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
+        pNode = &pNode[pNode->u.iAppend];
+        j = 1;
+      }
+      jsonAppendChar(pOut, ']');
+      break;
+    }
+    case JSON_OBJECT: {
+      u32 j = 1;
+      jsonAppendChar(pOut, '{');
+      for(;;){
+        while( j<=pNode->n ){
+          if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 ){
+            jsonAppendSeparator(pOut);
+            jsonRenderNode(&pNode[j], pOut, aReplace);
+            jsonAppendChar(pOut, ':');
+            if( pNode[j+1].jnFlags & JNODE_REPLACE ){
+              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal]);
+            }else{
+              jsonRenderNode(&pNode[j+1], pOut, aReplace);
+            }
+          }
+          j += 1 + jsonNodeSize(&pNode[j+1]);
+        }
+        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
+        pNode = &pNode[pNode->u.iAppend];
+        j = 1;
+      }
+      jsonAppendChar(pOut, '}');
+      break;
+    }
+  }
+}
+
+/*
+** Return a JsonNode and all its descendents as a JSON string.
+*/
+static void jsonReturnJson(
+  JsonNode *pNode,            /* Node to return */
+  sqlite3_context *pCtx,      /* Return value for this function */
+  sqlite3_value **aReplace    /* Array of replacement values */
+){
+  JsonString s;
+  jsonInit(&s, pCtx);
+  jsonRenderNode(pNode, &s, aReplace);
+  jsonResult(&s);
+  sqlite3_result_subtype(pCtx, JSON_SUBTYPE);
+}
+
+/*
+** Make the JsonNode the return value of the function.
+*/
+static void jsonReturn(
+  JsonNode *pNode,            /* Node to return */
+  sqlite3_context *pCtx,      /* Return value for this function */
+  sqlite3_value **aReplace    /* Array of replacement values */
+){
+  switch( pNode->eType ){
+    default: {
+      assert( pNode->eType==JSON_NULL );
+      sqlite3_result_null(pCtx);
+      break;
+    }
+    case JSON_TRUE: {
+      sqlite3_result_int(pCtx, 1);
+      break;
+    }
+    case JSON_FALSE: {
+      sqlite3_result_int(pCtx, 0);
+      break;
+    }
+    case JSON_INT: {
+      sqlite3_int64 i = 0;
+      const char *z = pNode->u.zJContent;
+      if( z[0]=='-' ){ z++; }
+      while( z[0]>='0' && z[0]<='9' ){
+        unsigned v = *(z++) - '0';
+        if( i>=LARGEST_INT64/10 ){
+          if( i>LARGEST_INT64/10 ) goto int_as_real;
+          if( z[0]>='0' && z[0]<='9' ) goto int_as_real;
+          if( v==9 ) goto int_as_real;
+          if( v==8 ){
+            if( pNode->u.zJContent[0]=='-' ){
+              sqlite3_result_int64(pCtx, SMALLEST_INT64);
+              goto int_done;
+            }else{
+              goto int_as_real;
+            }
+          }
+        }
+        i = i*10 + v;
+      }
+      if( pNode->u.zJContent[0]=='-' ){ i = -i; }
+      sqlite3_result_int64(pCtx, i);
+      int_done:
+      break;
+      int_as_real: /* fall through to real */;
+    }
+    case JSON_REAL: {
+      double r;
+#ifdef SQLITE_AMALGAMATION
+      const char *z = pNode->u.zJContent;
+      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
+#else
+      r = strtod(pNode->u.zJContent, 0);
+#endif
+      sqlite3_result_double(pCtx, r);
+      break;
+    }
+    case JSON_STRING: {
+#if 0 /* Never happens because JNODE_RAW is only set by json_set(),
+      ** json_insert() and json_replace() and those routines do not
+      ** call jsonReturn() */
+      if( pNode->jnFlags & JNODE_RAW ){
+        sqlite3_result_text(pCtx, pNode->u.zJContent, pNode->n,
+                            SQLITE_TRANSIENT);
+      }else 
+#endif
+      assert( (pNode->jnFlags & JNODE_RAW)==0 );
+      if( (pNode->jnFlags & JNODE_ESCAPE)==0 ){
+        /* JSON formatted without any backslash-escapes */
+        sqlite3_result_text(pCtx, pNode->u.zJContent+1, pNode->n-2,
+                            SQLITE_TRANSIENT);
+      }else{
+        /* Translate JSON formatted string into raw text */
+        u32 i;
+        u32 n = pNode->n;
+        const char *z = pNode->u.zJContent;
+        char *zOut;
+        u32 j;
+        zOut = sqlite3_malloc( n+1 );
+        if( zOut==0 ){
+          sqlite3_result_error_nomem(pCtx);
+          break;
+        }
+        for(i=1, j=0; i<n-1; i++){
+          char c = z[i];
+          if( c!='\\' ){
+            zOut[j++] = c;
+          }else{
+            c = z[++i];
+            if( c=='u' ){
+              u32 v = 0, k;
+              for(k=0; k<4 && i<n-2; i++, k++){
+                c = z[i+1];
+                if( c>='0' && c<='9' ) v = v*16 + c - '0';
+                else if( c>='A' && c<='F' ) v = v*16 + c - 'A' + 10;
+                else if( c>='a' && c<='f' ) v = v*16 + c - 'a' + 10;
+                else break;
+              }
+              if( v==0 ) break;
+              if( v<=0x7f ){
+                zOut[j++] = (char)v;
+              }else if( v<=0x7ff ){
+                zOut[j++] = (char)(0xc0 | (v>>6));
+                zOut[j++] = 0x80 | (v&0x3f);
+              }else{
+                zOut[j++] = (char)(0xe0 | (v>>12));
+                zOut[j++] = 0x80 | ((v>>6)&0x3f);
+                zOut[j++] = 0x80 | (v&0x3f);
+              }
+            }else{
+              if( c=='b' ){
+                c = '\b';
+              }else if( c=='f' ){
+                c = '\f';
+              }else if( c=='n' ){
+                c = '\n';
+              }else if( c=='r' ){
+                c = '\r';
+              }else if( c=='t' ){
+                c = '\t';
+              }
+              zOut[j++] = c;
+            }
+          }
+        }
+        zOut[j] = 0;
+        sqlite3_result_text(pCtx, zOut, j, sqlite3_free);
+      }
+      break;
+    }
+    case JSON_ARRAY:
+    case JSON_OBJECT: {
+      jsonReturnJson(pNode, pCtx, aReplace);
+      break;
+    }
+  }
+}
+
+/* Forward reference */
+static int jsonParseAddNode(JsonParse*,u32,u32,const char*);
+
+/*
+** A macro to hint to the compiler that a function should not be
+** inlined.
+*/
+#if defined(__GNUC__)
+#  define JSON_NOINLINE  __attribute__((noinline))
+#elif defined(_MSC_VER) && _MSC_VER>=1310
+#  define JSON_NOINLINE  __declspec(noinline)
+#else
+#  define JSON_NOINLINE
+#endif
+
+
+static JSON_NOINLINE int jsonParseAddNodeExpand(
+  JsonParse *pParse,        /* Append the node to this object */
+  u32 eType,                /* Node type */
+  u32 n,                    /* Content size or sub-node count */
+  const char *zContent      /* Content */
+){
+  u32 nNew;
+  JsonNode *pNew;
+  assert( pParse->nNode>=pParse->nAlloc );
+  if( pParse->oom ) return -1;
+  nNew = pParse->nAlloc*2 + 10;
+  pNew = sqlite3_realloc(pParse->aNode, sizeof(JsonNode)*nNew);
+  if( pNew==0 ){
+    pParse->oom = 1;
+    return -1;
+  }
+  pParse->nAlloc = nNew;
+  pParse->aNode = pNew;
+  assert( pParse->nNode<pParse->nAlloc );
+  return jsonParseAddNode(pParse, eType, n, zContent);
+}
+
+/*
+** Create a new JsonNode instance based on the arguments and append that
+** instance to the JsonParse.  Return the index in pParse->aNode[] of the
+** new node, or -1 if a memory allocation fails.
+*/
+static int jsonParseAddNode(
+  JsonParse *pParse,        /* Append the node to this object */
+  u32 eType,                /* Node type */
+  u32 n,                    /* Content size or sub-node count */
+  const char *zContent      /* Content */
+){
+  JsonNode *p;
+  if( pParse->nNode>=pParse->nAlloc ){
+    return jsonParseAddNodeExpand(pParse, eType, n, zContent);
+  }
+  p = &pParse->aNode[pParse->nNode];
+  p->eType = (u8)eType;
+  p->jnFlags = 0;
+  p->iVal = 0;
+  p->n = n;
+  p->u.zJContent = zContent;
+  return pParse->nNode++;
+}
+
+/*
+** Parse a single JSON value which begins at pParse->zJson[i].  Return the
+** index of the first character past the end of the value parsed.
+**
+** Return negative for a syntax error.  Special cases:  return -2 if the
+** first non-whitespace character is '}' and return -3 if the first
+** non-whitespace character is ']'.
+*/
+static int jsonParseValue(JsonParse *pParse, u32 i){
+  char c;
+  u32 j;
+  int iThis;
+  int x;
+  JsonNode *pNode;
+  while( safe_isspace(pParse->zJson[i]) ){ i++; }
+  if( (c = pParse->zJson[i])=='{' ){
+    /* Parse object */
+    iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
+    if( iThis<0 ) return -1;
+    for(j=i+1;;j++){
+      while( safe_isspace(pParse->zJson[j]) ){ j++; }
+      x = jsonParseValue(pParse, j);
+      if( x<0 ){
+        if( x==(-2) && pParse->nNode==(u32)iThis+1 ) return j+1;
+        return -1;
+      }
+      if( pParse->oom ) return -1;
+      pNode = &pParse->aNode[pParse->nNode-1];
+      if( pNode->eType!=JSON_STRING ) return -1;
+      pNode->jnFlags |= JNODE_LABEL;
+      j = x;
+      while( safe_isspace(pParse->zJson[j]) ){ j++; }
+      if( pParse->zJson[j]!=':' ) return -1;
+      j++;
+      x = jsonParseValue(pParse, j);
+      if( x<0 ) return -1;
+      j = x;
+      while( safe_isspace(pParse->zJson[j]) ){ j++; }
+      c = pParse->zJson[j];
+      if( c==',' ) continue;
+      if( c!='}' ) return -1;
+      break;
+    }
+    pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;
+    return j+1;
+  }else if( c=='[' ){
+    /* Parse array */
+    iThis = jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);
+    if( iThis<0 ) return -1;
+    for(j=i+1;;j++){
+      while( safe_isspace(pParse->zJson[j]) ){ j++; }
+      x = jsonParseValue(pParse, j);
+      if( x<0 ){
+        if( x==(-3) && pParse->nNode==(u32)iThis+1 ) return j+1;
+        return -1;
+      }
+      j = x;
+      while( safe_isspace(pParse->zJson[j]) ){ j++; }
+      c = pParse->zJson[j];
+      if( c==',' ) continue;
+      if( c!=']' ) return -1;
+      break;
+    }
+    pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;
+    return j+1;
+  }else if( c=='"' ){
+    /* Parse string */
+    u8 jnFlags = 0;
+    j = i+1;
+    for(;;){
+      c = pParse->zJson[j];
+      if( c==0 ) return -1;
+      if( c=='\\' ){
+        c = pParse->zJson[++j];
+        if( c==0 ) return -1;
+        jnFlags = JNODE_ESCAPE;
+      }else if( c=='"' ){
+        break;
+      }
+      j++;
+    }
+    jsonParseAddNode(pParse, JSON_STRING, j+1-i, &pParse->zJson[i]);
+    if( !pParse->oom ) pParse->aNode[pParse->nNode-1].jnFlags = jnFlags;
+    return j+1;
+  }else if( c=='n'
+         && strncmp(pParse->zJson+i,"null",4)==0
+         && !safe_isalnum(pParse->zJson[i+4]) ){
+    jsonParseAddNode(pParse, JSON_NULL, 0, 0);
+    return i+4;
+  }else if( c=='t'
+         && strncmp(pParse->zJson+i,"true",4)==0
+         && !safe_isalnum(pParse->zJson[i+4]) ){
+    jsonParseAddNode(pParse, JSON_TRUE, 0, 0);
+    return i+4;
+  }else if( c=='f'
+         && strncmp(pParse->zJson+i,"false",5)==0
+         && !safe_isalnum(pParse->zJson[i+5]) ){
+    jsonParseAddNode(pParse, JSON_FALSE, 0, 0);
+    return i+5;
+  }else if( c=='-' || (c>='0' && c<='9') ){
+    /* Parse number */
+    u8 seenDP = 0;
+    u8 seenE = 0;
+    j = i+1;
+    for(;; j++){
+      c = pParse->zJson[j];
+      if( c>='0' && c<='9' ) continue;
+      if( c=='.' ){
+        if( pParse->zJson[j-1]=='-' ) return -1;
+        if( seenDP ) return -1;
+        seenDP = 1;
+        continue;
+      }
+      if( c=='e' || c=='E' ){
+        if( pParse->zJson[j-1]<'0' ) return -1;
+        if( seenE ) return -1;
+        seenDP = seenE = 1;
+        c = pParse->zJson[j+1];
+        if( c=='+' || c=='-' ){
+          j++;
+          c = pParse->zJson[j+1];
+        }
+        if( c<'0' || c>'9' ) return -1;
+        continue;
+      }
+      break;
+    }
+    if( pParse->zJson[j-1]<'0' ) return -1;
+    jsonParseAddNode(pParse, seenDP ? JSON_REAL : JSON_INT,
+                        j - i, &pParse->zJson[i]);
+    return j;
+  }else if( c=='}' ){
+    return -2;  /* End of {...} */
+  }else if( c==']' ){
+    return -3;  /* End of [...] */
+  }else if( c==0 ){
+    return 0;   /* End of file */
+  }else{
+    return -1;  /* Syntax error */
+  }
+}
+
+/*
+** Parse a complete JSON string.  Return 0 on success or non-zero if there
+** are any errors.  If an error occurs, free all memory associated with
+** pParse.
+**
+** pParse is uninitialized when this routine is called.
+*/
+static int jsonParse(
+  JsonParse *pParse,           /* Initialize and fill this JsonParse object */
+  sqlite3_context *pCtx,       /* Report errors here */
+  const char *zJson            /* Input JSON text to be parsed */
+){
+  int i;
+  memset(pParse, 0, sizeof(*pParse));
+  if( zJson==0 ) return 1;
+  pParse->zJson = zJson;
+  i = jsonParseValue(pParse, 0);
+  if( pParse->oom ) i = -1;
+  if( i>0 ){
+    while( safe_isspace(zJson[i]) ) i++;
+    if( zJson[i] ) i = -1;
+  }
+  if( i<=0 ){
+    if( pCtx!=0 ){
+      if( pParse->oom ){
+        sqlite3_result_error_nomem(pCtx);
+      }else{
+        sqlite3_result_error(pCtx, "malformed JSON", -1);
+      }
+    }
+    jsonParseReset(pParse);
+    return 1;
+  }
+  return 0;
+}
+
+/* Mark node i of pParse as being a child of iParent.  Call recursively
+** to fill in all the descendants of node i.
+*/
+static void jsonParseFillInParentage(JsonParse *pParse, u32 i, u32 iParent){
+  JsonNode *pNode = &pParse->aNode[i];
+  u32 j;
+  pParse->aUp[i] = iParent;
+  switch( pNode->eType ){
+    case JSON_ARRAY: {
+      for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j)){
+        jsonParseFillInParentage(pParse, i+j, i);
+      }
+      break;
+    }
+    case JSON_OBJECT: {
+      for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j+1)+1){
+        pParse->aUp[i+j] = i;
+        jsonParseFillInParentage(pParse, i+j+1, i);
+      }
+      break;
+    }
+    default: {
+      break;
+    }
+  }
+}
+
+/*
+** Compute the parentage of all nodes in a completed parse.
+*/
+static int jsonParseFindParents(JsonParse *pParse){
+  u32 *aUp;
+  assert( pParse->aUp==0 );
+  aUp = pParse->aUp = sqlite3_malloc( sizeof(u32)*pParse->nNode );
+  if( aUp==0 ){
+    pParse->oom = 1;
+    return SQLITE_NOMEM;
+  }
+  jsonParseFillInParentage(pParse, 0, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Compare the OBJECT label at pNode against zKey,nKey.  Return true on
+** a match.
+*/
+static int jsonLabelCompare(JsonNode *pNode, const char *zKey, u32 nKey){
+  if( pNode->jnFlags & JNODE_RAW ){
+    if( pNode->n!=nKey ) return 0;
+    return strncmp(pNode->u.zJContent, zKey, nKey)==0;
+  }else{
+    if( pNode->n!=nKey+2 ) return 0;
+    return strncmp(pNode->u.zJContent+1, zKey, nKey)==0;
+  }
+}
+
+/* forward declaration */
+static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*,const char**);
+
+/*
+** Search along zPath to find the node specified.  Return a pointer
+** to that node, or NULL if zPath is malformed or if there is no such
+** node.
+**
+** If pApnd!=0, then try to append new nodes to complete zPath if it is
+** possible to do so and if no existing node corresponds to zPath.  If
+** new nodes are appended *pApnd is set to 1.
+*/
+static JsonNode *jsonLookupStep(
+  JsonParse *pParse,      /* The JSON to search */
+  u32 iRoot,              /* Begin the search at this node */
+  const char *zPath,      /* The path to search */
+  int *pApnd,             /* Append nodes to complete path if not NULL */
+  const char **pzErr      /* Make *pzErr point to any syntax error in zPath */
+){
+  u32 i, j, nKey;
+  const char *zKey;
+  JsonNode *pRoot = &pParse->aNode[iRoot];
+  if( zPath[0]==0 ) return pRoot;
+  if( zPath[0]=='.' ){
+    if( pRoot->eType!=JSON_OBJECT ) return 0;
+    zPath++;
+    if( zPath[0]=='"' ){
+      zKey = zPath + 1;
+      for(i=1; zPath[i] && zPath[i]!='"'; i++){}
+      nKey = i-1;
+      if( zPath[i] ){
+        i++;
+      }else{
+        *pzErr = zPath;
+        return 0;
+      }
+    }else{
+      zKey = zPath;
+      for(i=0; zPath[i] && zPath[i]!='.' && zPath[i]!='['; i++){}
+      nKey = i;
+    }
+    if( nKey==0 ){
+      *pzErr = zPath;
+      return 0;
+    }
+    j = 1;
+    for(;;){
+      while( j<=pRoot->n ){
+        if( jsonLabelCompare(pRoot+j, zKey, nKey) ){
+          return jsonLookupStep(pParse, iRoot+j+1, &zPath[i], pApnd, pzErr);
+        }
+        j++;
+        j += jsonNodeSize(&pRoot[j]);
+      }
+      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
+      iRoot += pRoot->u.iAppend;
+      pRoot = &pParse->aNode[iRoot];
+      j = 1;
+    }
+    if( pApnd ){
+      u32 iStart, iLabel;
+      JsonNode *pNode;
+      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);
+      iLabel = jsonParseAddNode(pParse, JSON_STRING, i, zPath);
+      zPath += i;
+      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
+      if( pParse->oom ) return 0;
+      if( pNode ){
+        pRoot = &pParse->aNode[iRoot];
+        pRoot->u.iAppend = iStart - iRoot;
+        pRoot->jnFlags |= JNODE_APPEND;
+        pParse->aNode[iLabel].jnFlags |= JNODE_RAW;
+      }
+      return pNode;
+    }
+  }else if( zPath[0]=='[' && safe_isdigit(zPath[1]) ){
+    if( pRoot->eType!=JSON_ARRAY ) return 0;
+    i = 0;
+    j = 1;
+    while( safe_isdigit(zPath[j]) ){
+      i = i*10 + zPath[j] - '0';
+      j++;
+    }
+    if( zPath[j]!=']' ){
+      *pzErr = zPath;
+      return 0;
+    }
+    zPath += j + 1;
+    j = 1;
+    for(;;){
+      while( j<=pRoot->n && (i>0 || (pRoot[j].jnFlags & JNODE_REMOVE)!=0) ){
+        if( (pRoot[j].jnFlags & JNODE_REMOVE)==0 ) i--;
+        j += jsonNodeSize(&pRoot[j]);
+      }
+      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
+      iRoot += pRoot->u.iAppend;
+      pRoot = &pParse->aNode[iRoot];
+      j = 1;
+    }
+    if( j<=pRoot->n ){
+      return jsonLookupStep(pParse, iRoot+j, zPath, pApnd, pzErr);
+    }
+    if( i==0 && pApnd ){
+      u32 iStart;
+      JsonNode *pNode;
+      iStart = jsonParseAddNode(pParse, JSON_ARRAY, 1, 0);
+      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
+      if( pParse->oom ) return 0;
+      if( pNode ){
+        pRoot = &pParse->aNode[iRoot];
+        pRoot->u.iAppend = iStart - iRoot;
+        pRoot->jnFlags |= JNODE_APPEND;
+      }
+      return pNode;
+    }
+  }else{
+    *pzErr = zPath;
+  }
+  return 0;
+}
+
+/*
+** Append content to pParse that will complete zPath.  Return a pointer
+** to the inserted node, or return NULL if the append fails.
+*/
+static JsonNode *jsonLookupAppend(
+  JsonParse *pParse,     /* Append content to the JSON parse */
+  const char *zPath,     /* Description of content to append */
+  int *pApnd,            /* Set this flag to 1 */
+  const char **pzErr     /* Make this point to any syntax error */
+){
+  *pApnd = 1;
+  if( zPath[0]==0 ){
+    jsonParseAddNode(pParse, JSON_NULL, 0, 0);
+    return pParse->oom ? 0 : &pParse->aNode[pParse->nNode-1];
+  }
+  if( zPath[0]=='.' ){
+    jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
+  }else if( strncmp(zPath,"[0]",3)==0 ){
+    jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);
+  }else{
+    return 0;
+  }
+  if( pParse->oom ) return 0;
+  return jsonLookupStep(pParse, pParse->nNode-1, zPath, pApnd, pzErr);
+}
+
+/*
+** Return the text of a syntax error message on a JSON path.  Space is
+** obtained from sqlite3_malloc().
+*/
+static char *jsonPathSyntaxError(const char *zErr){
+  return sqlite3_mprintf("JSON path error near '%q'", zErr);
+}
+
+/*
+** Do a node lookup using zPath.  Return a pointer to the node on success.
+** Return NULL if not found or if there is an error.
+**
+** On an error, write an error message into pCtx and increment the
+** pParse->nErr counter.
+**
+** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
+** nodes are appended.
+*/
+static JsonNode *jsonLookup(
+  JsonParse *pParse,      /* The JSON to search */
+  const char *zPath,      /* The path to search */
+  int *pApnd,             /* Append nodes to complete path if not NULL */
+  sqlite3_context *pCtx   /* Report errors here, if not NULL */
+){
+  const char *zErr = 0;
+  JsonNode *pNode = 0;
+  char *zMsg;
+
+  if( zPath==0 ) return 0;
+  if( zPath[0]!='$' ){
+    zErr = zPath;
+    goto lookup_err;
+  }
+  zPath++;
+  pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
+  if( zErr==0 ) return pNode;
+
+lookup_err:
+  pParse->nErr++;
+  assert( zErr!=0 && pCtx!=0 );
+  zMsg = jsonPathSyntaxError(zErr);
+  if( zMsg ){
+    sqlite3_result_error(pCtx, zMsg, -1);
+    sqlite3_free(zMsg);
+  }else{
+    sqlite3_result_error_nomem(pCtx);
+  }
+  return 0;
+}
+
+
+/*
+** Report the wrong number of arguments for json_insert(), json_replace()
+** or json_set().
+*/
+static void jsonWrongNumArgs(
+  sqlite3_context *pCtx,
+  const char *zFuncName
+){
+  char *zMsg = sqlite3_mprintf("json_%s() needs an odd number of arguments",
+                               zFuncName);
+  sqlite3_result_error(pCtx, zMsg, -1);
+  sqlite3_free(zMsg);     
+}
+
+
+/****************************************************************************
+** SQL functions used for testing and debugging
+****************************************************************************/
+
+#ifdef SQLITE_DEBUG
+/*
+** The json_parse(JSON) function returns a string which describes
+** a parse of the JSON provided.  Or it returns NULL if JSON is not
+** well-formed.
+*/
+static void jsonParseFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString s;       /* Output string - not real JSON */
+  JsonParse x;        /* The parse */
+  u32 i;
+
+  assert( argc==1 );
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  jsonParseFindParents(&x);
+  jsonInit(&s, ctx);
+  for(i=0; i<x.nNode; i++){
+    const char *zType;
+    if( x.aNode[i].jnFlags & JNODE_LABEL ){
+      assert( x.aNode[i].eType==JSON_STRING );
+      zType = "label";
+    }else{
+      zType = jsonType[x.aNode[i].eType];
+    }
+    jsonPrintf(100, &s,"node %3u: %7s n=%-4d up=%-4d",
+               i, zType, x.aNode[i].n, x.aUp[i]);
+    if( x.aNode[i].u.zJContent!=0 ){
+      jsonAppendRaw(&s, " ", 1);
+      jsonAppendRaw(&s, x.aNode[i].u.zJContent, x.aNode[i].n);
+    }
+    jsonAppendRaw(&s, "\n", 1);
+  }
+  jsonParseReset(&x);
+  jsonResult(&s);
+}
+
+/*
+** The json_test1(JSON) function return true (1) if the input is JSON
+** text generated by another json function.  It returns (0) if the input
+** is not known to be JSON.
+*/
+static void jsonTest1Func(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  UNUSED_PARAM(argc);
+  sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);
+}
+#endif /* SQLITE_DEBUG */
+
+/****************************************************************************
+** Scalar SQL function implementations
+****************************************************************************/
+
+/*
+** Implementation of the json_QUOTE(VALUE) function.  Return a JSON value
+** corresponding to the SQL value input.  Mostly this means putting 
+** double-quotes around strings and returning the unquoted string "null"
+** when given a NULL input.
+*/
+static void jsonQuoteFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString jx;
+  UNUSED_PARAM(argc);
+
+  jsonInit(&jx, ctx);
+  jsonAppendValue(&jx, argv[0]);
+  jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+/*
+** Implementation of the json_array(VALUE,...) function.  Return a JSON
+** array that contains all values given in arguments.  Or if any argument
+** is a BLOB, throw an error.
+*/
+static void jsonArrayFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  JsonString jx;
+
+  jsonInit(&jx, ctx);
+  jsonAppendChar(&jx, '[');
+  for(i=0; i<argc; i++){
+    jsonAppendSeparator(&jx);
+    jsonAppendValue(&jx, argv[i]);
+  }
+  jsonAppendChar(&jx, ']');
+  jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+
+/*
+** json_array_length(JSON)
+** json_array_length(JSON, PATH)
+**
+** Return the number of elements in the top-level JSON array.  
+** Return 0 if the input is not a well-formed JSON array.
+*/
+static void jsonArrayLengthFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  sqlite3_int64 n = 0;
+  u32 i;
+  JsonNode *pNode;
+
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  assert( x.nNode );
+  if( argc==2 ){
+    const char *zPath = (const char*)sqlite3_value_text(argv[1]);
+    pNode = jsonLookup(&x, zPath, 0, ctx);
+  }else{
+    pNode = x.aNode;
+  }
+  if( pNode==0 ){
+    x.nErr = 1;
+  }else if( pNode->eType==JSON_ARRAY ){
+    assert( (pNode->jnFlags & JNODE_APPEND)==0 );
+    for(i=1; i<=pNode->n; n++){
+      i += jsonNodeSize(&pNode[i]);
+    }
+  }
+  if( x.nErr==0 ) sqlite3_result_int64(ctx, n);
+  jsonParseReset(&x);
+}
+
+/*
+** json_extract(JSON, PATH, ...)
+**
+** Return the element described by PATH.  Return NULL if there is no
+** PATH element.  If there are multiple PATHs, then return a JSON array
+** with the result from each path.  Throw an error if the JSON or any PATH
+** is malformed.
+*/
+static void jsonExtractFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  JsonNode *pNode;
+  const char *zPath;
+  JsonString jx;
+  int i;
+
+  if( argc<2 ) return;
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  jsonInit(&jx, ctx);
+  jsonAppendChar(&jx, '[');
+  for(i=1; i<argc; i++){
+    zPath = (const char*)sqlite3_value_text(argv[i]);
+    pNode = jsonLookup(&x, zPath, 0, ctx);
+    if( x.nErr ) break;
+    if( argc>2 ){
+      jsonAppendSeparator(&jx);
+      if( pNode ){
+        jsonRenderNode(pNode, &jx, 0);
+      }else{
+        jsonAppendRaw(&jx, "null", 4);
+      }
+    }else if( pNode ){
+      jsonReturn(pNode, ctx, 0);
+    }
+  }
+  if( argc>2 && i==argc ){
+    jsonAppendChar(&jx, ']');
+    jsonResult(&jx);
+    sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+  }
+  jsonReset(&jx);
+  jsonParseReset(&x);
+}
+
+/*
+** Implementation of the json_object(NAME,VALUE,...) function.  Return a JSON
+** object that contains all name/value given in arguments.  Or if any name
+** is not a string or if any value is a BLOB, throw an error.
+*/
+static void jsonObjectFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  JsonString jx;
+  const char *z;
+  u32 n;
+
+  if( argc&1 ){
+    sqlite3_result_error(ctx, "json_object() requires an even number "
+                                  "of arguments", -1);
+    return;
+  }
+  jsonInit(&jx, ctx);
+  jsonAppendChar(&jx, '{');
+  for(i=0; i<argc; i+=2){
+    if( sqlite3_value_type(argv[i])!=SQLITE_TEXT ){
+      sqlite3_result_error(ctx, "json_object() labels must be TEXT", -1);
+      jsonReset(&jx);
+      return;
+    }
+    jsonAppendSeparator(&jx);
+    z = (const char*)sqlite3_value_text(argv[i]);
+    n = (u32)sqlite3_value_bytes(argv[i]);
+    jsonAppendString(&jx, z, n);
+    jsonAppendChar(&jx, ':');
+    jsonAppendValue(&jx, argv[i+1]);
+  }
+  jsonAppendChar(&jx, '}');
+  jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+
+/*
+** json_remove(JSON, PATH, ...)
+**
+** Remove the named elements from JSON and return the result.  malformed
+** JSON or PATH arguments result in an error.
+*/
+static void jsonRemoveFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  JsonNode *pNode;
+  const char *zPath;
+  u32 i;
+
+  if( argc<1 ) return;
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  assert( x.nNode );
+  for(i=1; i<(u32)argc; i++){
+    zPath = (const char*)sqlite3_value_text(argv[i]);
+    if( zPath==0 ) goto remove_done;
+    pNode = jsonLookup(&x, zPath, 0, ctx);
+    if( x.nErr ) goto remove_done;
+    if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
+  }
+  if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){
+    jsonReturnJson(x.aNode, ctx, 0);
+  }
+remove_done:
+  jsonParseReset(&x);
+}
+
+/*
+** json_replace(JSON, PATH, VALUE, ...)
+**
+** Replace the value at PATH with VALUE.  If PATH does not already exist,
+** this routine is a no-op.  If JSON or PATH is malformed, throw an error.
+*/
+static void jsonReplaceFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  JsonNode *pNode;
+  const char *zPath;
+  u32 i;
+
+  if( argc<1 ) return;
+  if( (argc&1)==0 ) {
+    jsonWrongNumArgs(ctx, "replace");
+    return;
+  }
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  assert( x.nNode );
+  for(i=1; i<(u32)argc; i+=2){
+    zPath = (const char*)sqlite3_value_text(argv[i]);
+    pNode = jsonLookup(&x, zPath, 0, ctx);
+    if( x.nErr ) goto replace_err;
+    if( pNode ){
+      pNode->jnFlags |= (u8)JNODE_REPLACE;
+      pNode->iVal = (u8)(i+1);
+    }
+  }
+  if( x.aNode[0].jnFlags & JNODE_REPLACE ){
+    sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
+  }else{
+    jsonReturnJson(x.aNode, ctx, argv);
+  }
+replace_err:
+  jsonParseReset(&x);
+}
+
+/*
+** json_set(JSON, PATH, VALUE, ...)
+**
+** Set the value at PATH to VALUE.  Create the PATH if it does not already
+** exist.  Overwrite existing values that do exist.
+** If JSON or PATH is malformed, throw an error.
+**
+** json_insert(JSON, PATH, VALUE, ...)
+**
+** Create PATH and initialize it to VALUE.  If PATH already exists, this
+** routine is a no-op.  If JSON or PATH is malformed, throw an error.
+*/
+static void jsonSetFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  JsonNode *pNode;
+  const char *zPath;
+  u32 i;
+  int bApnd;
+  int bIsSet = *(int*)sqlite3_user_data(ctx);
+
+  if( argc<1 ) return;
+  if( (argc&1)==0 ) {
+    jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");
+    return;
+  }
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  assert( x.nNode );
+  for(i=1; i<(u32)argc; i+=2){
+    zPath = (const char*)sqlite3_value_text(argv[i]);
+    bApnd = 0;
+    pNode = jsonLookup(&x, zPath, &bApnd, ctx);
+    if( x.oom ){
+      sqlite3_result_error_nomem(ctx);
+      goto jsonSetDone;
+    }else if( x.nErr ){
+      goto jsonSetDone;
+    }else if( pNode && (bApnd || bIsSet) ){
+      pNode->jnFlags |= (u8)JNODE_REPLACE;
+      pNode->iVal = (u8)(i+1);
+    }
+  }
+  if( x.aNode[0].jnFlags & JNODE_REPLACE ){
+    sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
+  }else{
+    jsonReturnJson(x.aNode, ctx, argv);
+  }
+jsonSetDone:
+  jsonParseReset(&x);
+}
+
+/*
+** json_type(JSON)
+** json_type(JSON, PATH)
+**
+** Return the top-level "type" of a JSON string.  Throw an error if
+** either the JSON or PATH inputs are not well-formed.
+*/
+static void jsonTypeFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  const char *zPath;
+  JsonNode *pNode;
+
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  assert( x.nNode );
+  if( argc==2 ){
+    zPath = (const char*)sqlite3_value_text(argv[1]);
+    pNode = jsonLookup(&x, zPath, 0, ctx);
+  }else{
+    pNode = x.aNode;
+  }
+  if( pNode ){
+    sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);
+  }
+  jsonParseReset(&x);
+}
+
+/*
+** json_valid(JSON)
+**
+** Return 1 if JSON is a well-formed JSON string according to RFC-7159.
+** Return 0 otherwise.
+*/
+static void jsonValidFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonParse x;          /* The parse */
+  int rc = 0;
+
+  UNUSED_PARAM(argc);
+  if( jsonParse(&x, 0, (const char*)sqlite3_value_text(argv[0]))==0 ){
+    rc = 1;
+  }
+  jsonParseReset(&x);
+  sqlite3_result_int(ctx, rc);
+}
+
+
+/****************************************************************************
+** Aggregate SQL function implementations
+****************************************************************************/
+/*
+** json_group_array(VALUE)
+**
+** Return a JSON array composed of all values in the aggregate.
+*/
+static void jsonArrayStep(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString *pStr;
+  UNUSED_PARAM(argc);
+  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
+  if( pStr ){
+    if( pStr->zBuf==0 ){
+      jsonInit(pStr, ctx);
+      jsonAppendChar(pStr, '[');
+    }else{
+      jsonAppendChar(pStr, ',');
+      pStr->pCtx = ctx;
+    }
+    jsonAppendValue(pStr, argv[0]);
+  }
+}
+static void jsonArrayFinal(sqlite3_context *ctx){
+  JsonString *pStr;
+  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
+  if( pStr ){
+    pStr->pCtx = ctx;
+    jsonAppendChar(pStr, ']');
+    if( pStr->bErr ){
+      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
+      assert( pStr->bStatic );
+    }else{
+      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
+                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
+      pStr->bStatic = 1;
+    }
+  }else{
+    sqlite3_result_text(ctx, "[]", 2, SQLITE_STATIC);
+  }
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+/*
+** json_group_obj(NAME,VALUE)
+**
+** Return a JSON object composed of all names and values in the aggregate.
+*/
+static void jsonObjectStep(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString *pStr;
+  const char *z;
+  u32 n;
+  UNUSED_PARAM(argc);
+  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
+  if( pStr ){
+    if( pStr->zBuf==0 ){
+      jsonInit(pStr, ctx);
+      jsonAppendChar(pStr, '{');
+    }else{
+      jsonAppendChar(pStr, ',');
+      pStr->pCtx = ctx;
+    }
+    z = (const char*)sqlite3_value_text(argv[0]);
+    n = (u32)sqlite3_value_bytes(argv[0]);
+    jsonAppendString(pStr, z, n);
+    jsonAppendChar(pStr, ':');
+    jsonAppendValue(pStr, argv[1]);
+  }
+}
+static void jsonObjectFinal(sqlite3_context *ctx){
+  JsonString *pStr;
+  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
+  if( pStr ){
+    jsonAppendChar(pStr, '}');
+    if( pStr->bErr ){
+      if( pStr->bErr==0 ) sqlite3_result_error_nomem(ctx);
+      assert( pStr->bStatic );
+    }else{
+      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
+                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
+      pStr->bStatic = 1;
+    }
+  }else{
+    sqlite3_result_text(ctx, "{}", 2, SQLITE_STATIC);
+  }
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/****************************************************************************
+** The json_each virtual table
+****************************************************************************/
+typedef struct JsonEachCursor JsonEachCursor;
+struct JsonEachCursor {
+  sqlite3_vtab_cursor base;  /* Base class - must be first */
+  u32 iRowid;                /* The rowid */
+  u32 iBegin;                /* The first node of the scan */
+  u32 i;                     /* Index in sParse.aNode[] of current row */
+  u32 iEnd;                  /* EOF when i equals or exceeds this value */
+  u8 eType;                  /* Type of top-level element */
+  u8 bRecursive;             /* True for json_tree().  False for json_each() */
+  char *zJson;               /* Input JSON */
+  char *zRoot;               /* Path by which to filter zJson */
+  JsonParse sParse;          /* Parse of the input JSON */
+};
+
+/* Constructor for the json_each virtual table */
+static int jsonEachConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  sqlite3_vtab *pNew;
+  int rc;
+
+/* Column numbers */
+#define JEACH_KEY     0
+#define JEACH_VALUE   1
+#define JEACH_TYPE    2
+#define JEACH_ATOM    3
+#define JEACH_ID      4
+#define JEACH_PARENT  5
+#define JEACH_FULLKEY 6
+#define JEACH_PATH    7
+#define JEACH_JSON    8
+#define JEACH_ROOT    9
+
+  UNUSED_PARAM(pzErr);
+  UNUSED_PARAM(argv);
+  UNUSED_PARAM(argc);
+  UNUSED_PARAM(pAux);
+  rc = sqlite3_declare_vtab(db, 
+     "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,path,"
+                    "json HIDDEN,root HIDDEN)");
+  if( rc==SQLITE_OK ){
+    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
+    if( pNew==0 ) return SQLITE_NOMEM;
+    memset(pNew, 0, sizeof(*pNew));
+  }
+  return rc;
+}
+
+/* destructor for json_each virtual table */
+static int jsonEachDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+
+/* constructor for a JsonEachCursor object for json_each(). */
+static int jsonEachOpenEach(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
+  JsonEachCursor *pCur;
+
+  UNUSED_PARAM(p);
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/* constructor for a JsonEachCursor object for json_tree(). */
+static int jsonEachOpenTree(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
+  int rc = jsonEachOpenEach(p, ppCursor);
+  if( rc==SQLITE_OK ){
+    JsonEachCursor *pCur = (JsonEachCursor*)*ppCursor;
+    pCur->bRecursive = 1;
+  }
+  return rc;
+}
+
+/* Reset a JsonEachCursor back to its original state.  Free any memory
+** held. */
+static void jsonEachCursorReset(JsonEachCursor *p){
+  sqlite3_free(p->zJson);
+  sqlite3_free(p->zRoot);
+  jsonParseReset(&p->sParse);
+  p->iRowid = 0;
+  p->i = 0;
+  p->iEnd = 0;
+  p->eType = 0;
+  p->zJson = 0;
+  p->zRoot = 0;
+}
+
+/* Destructor for a jsonEachCursor object */
+static int jsonEachClose(sqlite3_vtab_cursor *cur){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  jsonEachCursorReset(p);
+  sqlite3_free(cur);
+  return SQLITE_OK;
+}
+
+/* Return TRUE if the jsonEachCursor object has been advanced off the end
+** of the JSON object */
+static int jsonEachEof(sqlite3_vtab_cursor *cur){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  return p->i >= p->iEnd;
+}
+
+/* Advance the cursor to the next element for json_tree() */
+static int jsonEachNext(sqlite3_vtab_cursor *cur){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  if( p->bRecursive ){
+    if( p->sParse.aNode[p->i].jnFlags & JNODE_LABEL ) p->i++;
+    p->i++;
+    p->iRowid++;
+    if( p->i<p->iEnd ){
+      u32 iUp = p->sParse.aUp[p->i];
+      JsonNode *pUp = &p->sParse.aNode[iUp];
+      p->eType = pUp->eType;
+      if( pUp->eType==JSON_ARRAY ){
+        if( iUp==p->i-1 ){
+          pUp->u.iKey = 0;
+        }else{
+          pUp->u.iKey++;
+        }
+      }
+    }
+  }else{
+    switch( p->eType ){
+      case JSON_ARRAY: {
+        p->i += jsonNodeSize(&p->sParse.aNode[p->i]);
+        p->iRowid++;
+        break;
+      }
+      case JSON_OBJECT: {
+        p->i += 1 + jsonNodeSize(&p->sParse.aNode[p->i+1]);
+        p->iRowid++;
+        break;
+      }
+      default: {
+        p->i = p->iEnd;
+        break;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+/* Append the name of the path for element i to pStr
+*/
+static void jsonEachComputePath(
+  JsonEachCursor *p,       /* The cursor */
+  JsonString *pStr,        /* Write the path here */
+  u32 i                    /* Path to this element */
+){
+  JsonNode *pNode, *pUp;
+  u32 iUp;
+  if( i==0 ){
+    jsonAppendChar(pStr, '$');
+    return;
+  }
+  iUp = p->sParse.aUp[i];
+  jsonEachComputePath(p, pStr, iUp);
+  pNode = &p->sParse.aNode[i];
+  pUp = &p->sParse.aNode[iUp];
+  if( pUp->eType==JSON_ARRAY ){
+    jsonPrintf(30, pStr, "[%d]", pUp->u.iKey);
+  }else{
+    assert( pUp->eType==JSON_OBJECT );
+    if( (pNode->jnFlags & JNODE_LABEL)==0 ) pNode--;
+    assert( pNode->eType==JSON_STRING );
+    assert( pNode->jnFlags & JNODE_LABEL );
+    jsonPrintf(pNode->n+1, pStr, ".%.*s", pNode->n-2, pNode->u.zJContent+1);
+  }
+}
+
+/* Return the value of a column */
+static int jsonEachColumn(
+  sqlite3_vtab_cursor *cur,   /* The cursor */
+  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
+  int i                       /* Which column to return */
+){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  JsonNode *pThis = &p->sParse.aNode[p->i];
+  switch( i ){
+    case JEACH_KEY: {
+      if( p->i==0 ) break;
+      if( p->eType==JSON_OBJECT ){
+        jsonReturn(pThis, ctx, 0);
+      }else if( p->eType==JSON_ARRAY ){
+        u32 iKey;
+        if( p->bRecursive ){
+          if( p->iRowid==0 ) break;
+          iKey = p->sParse.aNode[p->sParse.aUp[p->i]].u.iKey;
+        }else{
+          iKey = p->iRowid;
+        }
+        sqlite3_result_int64(ctx, (sqlite3_int64)iKey);
+      }
+      break;
+    }
+    case JEACH_VALUE: {
+      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
+      jsonReturn(pThis, ctx, 0);
+      break;
+    }
+    case JEACH_TYPE: {
+      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
+      sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);
+      break;
+    }
+    case JEACH_ATOM: {
+      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
+      if( pThis->eType>=JSON_ARRAY ) break;
+      jsonReturn(pThis, ctx, 0);
+      break;
+    }
+    case JEACH_ID: {
+      sqlite3_result_int64(ctx, 
+         (sqlite3_int64)p->i + ((pThis->jnFlags & JNODE_LABEL)!=0));
+      break;
+    }
+    case JEACH_PARENT: {
+      if( p->i>p->iBegin && p->bRecursive ){
+        sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);
+      }
+      break;
+    }
+    case JEACH_FULLKEY: {
+      JsonString x;
+      jsonInit(&x, ctx);
+      if( p->bRecursive ){
+        jsonEachComputePath(p, &x, p->i);
+      }else{
+        if( p->zRoot ){
+          jsonAppendRaw(&x, p->zRoot, (int)strlen(p->zRoot));
+        }else{
+          jsonAppendChar(&x, '$');
+        }
+        if( p->eType==JSON_ARRAY ){
+          jsonPrintf(30, &x, "[%d]", p->iRowid);
+        }else{
+          jsonPrintf(pThis->n, &x, ".%.*s", pThis->n-2, pThis->u.zJContent+1);
+        }
+      }
+      jsonResult(&x);
+      break;
+    }
+    case JEACH_PATH: {
+      if( p->bRecursive ){
+        JsonString x;
+        jsonInit(&x, ctx);
+        jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);
+        jsonResult(&x);
+        break;
+      }
+      /* For json_each() path and root are the same so fall through
+      ** into the root case */
+    }
+    case JEACH_ROOT: {
+      const char *zRoot = p->zRoot;
+       if( zRoot==0 ) zRoot = "$";
+      sqlite3_result_text(ctx, zRoot, -1, SQLITE_STATIC);
+      break;
+    }
+    case JEACH_JSON: {
+      assert( i==JEACH_JSON );
+      sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/* Return the current rowid value */
+static int jsonEachRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  *pRowid = p->iRowid;
+  return SQLITE_OK;
+}
+
+/* The query strategy is to look for an equality constraint on the json
+** column.  Without such a constraint, the table cannot operate.  idxNum is
+** 1 if the constraint is found, 3 if the constraint and zRoot are found,
+** and 0 otherwise.
+*/
+static int jsonEachBestIndex(
+  sqlite3_vtab *tab,
+  sqlite3_index_info *pIdxInfo
+){
+  int i;
+  int jsonIdx = -1;
+  int rootIdx = -1;
+  const struct sqlite3_index_constraint *pConstraint;
+
+  UNUSED_PARAM(tab);
+  pConstraint = pIdxInfo->aConstraint;
+  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->usable==0 ) continue;
+    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
+    switch( pConstraint->iColumn ){
+      case JEACH_JSON:   jsonIdx = i;    break;
+      case JEACH_ROOT:   rootIdx = i;    break;
+      default:           /* no-op */     break;
+    }
+  }
+  if( jsonIdx<0 ){
+    pIdxInfo->idxNum = 0;
+    pIdxInfo->estimatedCost = 1e99;
+  }else{
+    pIdxInfo->estimatedCost = 1.0;
+    pIdxInfo->aConstraintUsage[jsonIdx].argvIndex = 1;
+    pIdxInfo->aConstraintUsage[jsonIdx].omit = 1;
+    if( rootIdx<0 ){
+      pIdxInfo->idxNum = 1;
+    }else{
+      pIdxInfo->aConstraintUsage[rootIdx].argvIndex = 2;
+      pIdxInfo->aConstraintUsage[rootIdx].omit = 1;
+      pIdxInfo->idxNum = 3;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/* Start a search on a new JSON string */
+static int jsonEachFilter(
+  sqlite3_vtab_cursor *cur,
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  JsonEachCursor *p = (JsonEachCursor*)cur;
+  const char *z;
+  const char *zRoot = 0;
+  sqlite3_int64 n;
+
+  UNUSED_PARAM(idxStr);
+  UNUSED_PARAM(argc);
+  jsonEachCursorReset(p);
+  if( idxNum==0 ) return SQLITE_OK;
+  z = (const char*)sqlite3_value_text(argv[0]);
+  if( z==0 ) return SQLITE_OK;
+  n = sqlite3_value_bytes(argv[0]);
+  p->zJson = sqlite3_malloc64( n+1 );
+  if( p->zJson==0 ) return SQLITE_NOMEM;
+  memcpy(p->zJson, z, (size_t)n+1);
+  if( jsonParse(&p->sParse, 0, p->zJson) ){
+    int rc = SQLITE_NOMEM;
+    if( p->sParse.oom==0 ){
+      sqlite3_free(cur->pVtab->zErrMsg);
+      cur->pVtab->zErrMsg = sqlite3_mprintf("malformed JSON");
+      if( cur->pVtab->zErrMsg ) rc = SQLITE_ERROR;
+    }
+    jsonEachCursorReset(p);
+    return rc;
+  }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){
+    jsonEachCursorReset(p);
+    return SQLITE_NOMEM;
+  }else{
+    JsonNode *pNode = 0;
+    if( idxNum==3 ){
+      const char *zErr = 0;
+      zRoot = (const char*)sqlite3_value_text(argv[1]);
+      if( zRoot==0 ) return SQLITE_OK;
+      n = sqlite3_value_bytes(argv[1]);
+      p->zRoot = sqlite3_malloc64( n+1 );
+      if( p->zRoot==0 ) return SQLITE_NOMEM;
+      memcpy(p->zRoot, zRoot, (size_t)n+1);
+      if( zRoot[0]!='$' ){
+        zErr = zRoot;
+      }else{
+        pNode = jsonLookupStep(&p->sParse, 0, p->zRoot+1, 0, &zErr);
+      }
+      if( zErr ){
+        sqlite3_free(cur->pVtab->zErrMsg);
+        cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);
+        jsonEachCursorReset(p);
+        return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
+      }else if( pNode==0 ){
+        return SQLITE_OK;
+      }
+    }else{
+      pNode = p->sParse.aNode;
+    }
+    p->iBegin = p->i = (int)(pNode - p->sParse.aNode);
+    p->eType = pNode->eType;
+    if( p->eType>=JSON_ARRAY ){
+      pNode->u.iKey = 0;
+      p->iEnd = p->i + pNode->n + 1;
+      if( p->bRecursive ){
+        p->eType = p->sParse.aNode[p->sParse.aUp[p->i]].eType;
+        if( p->i>0 && (p->sParse.aNode[p->i-1].jnFlags & JNODE_LABEL)!=0 ){
+          p->i--;
+        }
+      }else{
+        p->i++;
+      }
+    }else{
+      p->iEnd = p->i+1;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/* The methods of the json_each virtual table */
+static sqlite3_module jsonEachModule = {
+  0,                         /* iVersion */
+  0,                         /* xCreate */
+  jsonEachConnect,           /* xConnect */
+  jsonEachBestIndex,         /* xBestIndex */
+  jsonEachDisconnect,        /* xDisconnect */
+  0,                         /* xDestroy */
+  jsonEachOpenEach,          /* xOpen - open a cursor */
+  jsonEachClose,             /* xClose - close a cursor */
+  jsonEachFilter,            /* xFilter - configure scan constraints */
+  jsonEachNext,              /* xNext - advance a cursor */
+  jsonEachEof,               /* xEof - check for end of scan */
+  jsonEachColumn,            /* xColumn - read data */
+  jsonEachRowid,             /* xRowid - read data */
+  0,                         /* xUpdate */
+  0,                         /* xBegin */
+  0,                         /* xSync */
+  0,                         /* xCommit */
+  0,                         /* xRollback */
+  0,                         /* xFindMethod */
+  0,                         /* xRename */
+  0,                         /* xSavepoint */
+  0,                         /* xRelease */
+  0                          /* xRollbackTo */
+};
+
+/* The methods of the json_tree virtual table. */
+static sqlite3_module jsonTreeModule = {
+  0,                         /* iVersion */
+  0,                         /* xCreate */
+  jsonEachConnect,           /* xConnect */
+  jsonEachBestIndex,         /* xBestIndex */
+  jsonEachDisconnect,        /* xDisconnect */
+  0,                         /* xDestroy */
+  jsonEachOpenTree,          /* xOpen - open a cursor */
+  jsonEachClose,             /* xClose - close a cursor */
+  jsonEachFilter,            /* xFilter - configure scan constraints */
+  jsonEachNext,              /* xNext - advance a cursor */
+  jsonEachEof,               /* xEof - check for end of scan */
+  jsonEachColumn,            /* xColumn - read data */
+  jsonEachRowid,             /* xRowid - read data */
+  0,                         /* xUpdate */
+  0,                         /* xBegin */
+  0,                         /* xSync */
+  0,                         /* xCommit */
+  0,                         /* xRollback */
+  0,                         /* xFindMethod */
+  0,                         /* xRename */
+  0,                         /* xSavepoint */
+  0,                         /* xRelease */
+  0                          /* xRollbackTo */
+};
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/****************************************************************************
+** The following routines are the only publically visible identifiers in this
+** file.  Call the following routines in order to register the various SQL
+** functions and the virtual table implemented by this file.
+****************************************************************************/
+
+SQLITE_PRIVATE int sqlite3Json1Init(sqlite3 *db){
+  int rc = SQLITE_OK;
+  unsigned int i;
+  static const struct {
+     const char *zName;
+     int nArg;
+     int flag;
+     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } aFunc[] = {
+    { "json",                 1, 0,   jsonRemoveFunc        },
+    { "json_array",          -1, 0,   jsonArrayFunc         },
+    { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
+    { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
+    { "json_extract",        -1, 0,   jsonExtractFunc       },
+    { "json_insert",         -1, 0,   jsonSetFunc           },
+    { "json_object",         -1, 0,   jsonObjectFunc        },
+    { "json_quote",           1, 0,   jsonQuoteFunc         },
+    { "json_remove",         -1, 0,   jsonRemoveFunc        },
+    { "json_replace",        -1, 0,   jsonReplaceFunc       },
+    { "json_set",            -1, 1,   jsonSetFunc           },
+    { "json_type",            1, 0,   jsonTypeFunc          },
+    { "json_type",            2, 0,   jsonTypeFunc          },
+    { "json_valid",           1, 0,   jsonValidFunc         },
+
+#if SQLITE_DEBUG
+    /* DEBUG and TESTING functions */
+    { "json_parse",           1, 0,   jsonParseFunc         },
+    { "json_test1",           1, 0,   jsonTest1Func         },
+#endif
+  };
+  static const struct {
+     const char *zName;
+     int nArg;
+     void (*xStep)(sqlite3_context*,int,sqlite3_value**);
+     void (*xFinal)(sqlite3_context*);
+  } aAgg[] = {
+    { "json_group_array",     1,   jsonArrayStep,   jsonArrayFinal  },
+    { "json_group_object",    2,   jsonObjectStep,  jsonObjectFinal },
+  };
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  static const struct {
+     const char *zName;
+     sqlite3_module *pModule;
+  } aMod[] = {
+    { "json_each",            &jsonEachModule               },
+    { "json_tree",            &jsonTreeModule               },
+  };
+#endif
+  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
+    rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,
+                                 SQLITE_UTF8 | SQLITE_DETERMINISTIC, 
+                                 (void*)&aFunc[i].flag,
+                                 aFunc[i].xFunc, 0, 0);
+  }
+  for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){
+    rc = sqlite3_create_function(db, aAgg[i].zName, aAgg[i].nArg,
+                                 SQLITE_UTF8 | SQLITE_DETERMINISTIC, 0,
+                                 0, aAgg[i].xStep, aAgg[i].xFinal);
+  }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  for(i=0; i<sizeof(aMod)/sizeof(aMod[0]) && rc==SQLITE_OK; i++){
+    rc = sqlite3_create_module(db, aMod[i].zName, aMod[i].pModule, 0);
+  }
+#endif
+  return rc;
+}
+
+
+#ifndef SQLITE_CORE
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_json_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  return sqlite3Json1Init(db);
+}
+#endif
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */
+
+/************** End of json1.c ***********************************************/
+/************** Begin file fts5.c ********************************************/
+
+
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS5) 
+
+#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
+# define NDEBUG 1
+#endif
+#if defined(NDEBUG) && defined(SQLITE_DEBUG)
+# undef NDEBUG
+#endif
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Interfaces to extend FTS5. Using the interfaces defined in this file, 
+** FTS5 may be extended with:
+**
+**     * custom tokenizers, and
+**     * custom auxiliary functions.
+*/
+
+
+#ifndef _FTS5_H
+#define _FTS5_H
+
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif
+
+/*************************************************************************
+** CUSTOM AUXILIARY FUNCTIONS
+**
+** Virtual table implementations may overload SQL functions by implementing
+** the sqlite3_module.xFindFunction() method.
+*/
+
+typedef struct Fts5ExtensionApi Fts5ExtensionApi;
+typedef struct Fts5Context Fts5Context;
+typedef struct Fts5PhraseIter Fts5PhraseIter;
+
+typedef void (*fts5_extension_function)(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+);
+
+struct Fts5PhraseIter {
+  const unsigned char *a;
+  const unsigned char *b;
+};
+
+/*
+** EXTENSION API FUNCTIONS
+**
+** xUserData(pFts):
+**   Return a copy of the context pointer the extension function was 
+**   registered with.
+**
+** xColumnTotalSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the FTS5 table. Or, if iCol is
+**   non-negative but less than the number of columns in the table, return
+**   the total number of tokens in column iCol, considering all rows in 
+**   the FTS5 table.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+** xColumnCount(pFts):
+**   Return the number of columns in the table.
+**
+** xColumnSize(pFts, iCol, pnToken):
+**   If parameter iCol is less than zero, set output variable *pnToken
+**   to the total number of tokens in the current row. Or, if iCol is
+**   non-negative but less than the number of columns in the table, set
+**   *pnToken to the number of tokens in column iCol of the current row.
+**
+**   If parameter iCol is greater than or equal to the number of columns
+**   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
+**   an OOM condition or IO error), an appropriate SQLite error code is 
+**   returned.
+**
+**   This function may be quite inefficient if used with an FTS5 table
+**   created with the "columnsize=0" option.
+**
+** xColumnText:
+**   This function attempts to retrieve the text of column iCol of the
+**   current document. If successful, (*pz) is set to point to a buffer
+**   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
+**   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
+**   if an error occurs, an SQLite error code is returned and the final values
+**   of (*pz) and (*pn) are undefined.
+**
+** xPhraseCount:
+**   Returns the number of phrases in the current query expression.
+**
+** xPhraseSize:
+**   Returns the number of tokens in phrase iPhrase of the query. Phrases
+**   are numbered starting from zero.
+**
+** xInstCount:
+**   Set *pnInst to the total number of occurrences of all phrases within
+**   the query within the current row. Return SQLITE_OK if successful, or
+**   an error code (i.e. SQLITE_NOMEM) if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always returns 0.
+**
+** xInst:
+**   Query for the details of phrase match iIdx within the current row.
+**   Phrase matches are numbered starting from zero, so the iIdx argument
+**   should be greater than or equal to zero and smaller than the value
+**   output by xInstCount().
+**
+**   Usually, output parameter *piPhrase is set to the phrase number, *piCol
+**   to the column in which it occurs and *piOff the token offset of the
+**   first token of the phrase. The exception is if the table was created
+**   with the offsets=0 option specified. In this case *piOff is always
+**   set to -1.
+**
+**   Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 
+**   if an error occurs.
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. 
+**
+** xRowid:
+**   Returns the rowid of the current row.
+**
+** xTokenize:
+**   Tokenize text using the tokenizer belonging to the FTS5 table.
+**
+** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
+**   This API function is used to query the FTS table for phrase iPhrase
+**   of the current query. Specifically, a query equivalent to:
+**
+**       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
+**
+**   with $p set to a phrase equivalent to the phrase iPhrase of the
+**   current query is executed. Any column filter that applies to
+**   phrase iPhrase of the current query is included in $p. For each 
+**   row visited, the callback function passed as the fourth argument 
+**   is invoked. The context and API objects passed to the callback 
+**   function may be used to access the properties of each matched row.
+**   Invoking Api.xUserData() returns a copy of the pointer passed as 
+**   the third argument to pUserData.
+**
+**   If the callback function returns any value other than SQLITE_OK, the
+**   query is abandoned and the xQueryPhrase function returns immediately.
+**   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
+**   Otherwise, the error code is propagated upwards.
+**
+**   If the query runs to completion without incident, SQLITE_OK is returned.
+**   Or, if some error occurs before the query completes or is aborted by
+**   the callback, an SQLite error code is returned.
+**
+**
+** xSetAuxdata(pFts5, pAux, xDelete)
+**
+**   Save the pointer passed as the second argument as the extension functions 
+**   "auxiliary data". The pointer may then be retrieved by the current or any
+**   future invocation of the same fts5 extension function made as part of
+**   of the same MATCH query using the xGetAuxdata() API.
+**
+**   Each extension function is allocated a single auxiliary data slot for
+**   each FTS query (MATCH expression). If the extension function is invoked 
+**   more than once for a single FTS query, then all invocations share a 
+**   single auxiliary data context.
+**
+**   If there is already an auxiliary data pointer when this function is
+**   invoked, then it is replaced by the new pointer. If an xDelete callback
+**   was specified along with the original pointer, it is invoked at this
+**   point.
+**
+**   The xDelete callback, if one is specified, is also invoked on the
+**   auxiliary data pointer after the FTS5 query has finished.
+**
+**   If an error (e.g. an OOM condition) occurs within this function, an
+**   the auxiliary data is set to NULL and an error code returned. If the
+**   xDelete parameter was not NULL, it is invoked on the auxiliary data
+**   pointer before returning.
+**
+**
+** xGetAuxdata(pFts5, bClear)
+**
+**   Returns the current auxiliary data pointer for the fts5 extension 
+**   function. See the xSetAuxdata() method for details.
+**
+**   If the bClear argument is non-zero, then the auxiliary data is cleared
+**   (set to NULL) before this function returns. In this case the xDelete,
+**   if any, is not invoked.
+**
+**
+** xRowCount(pFts5, pnRow)
+**
+**   This function is used to retrieve the total number of rows in the table.
+**   In other words, the same value that would be returned by:
+**
+**        SELECT count(*) FROM ftstable;
+**
+** xPhraseFirst()
+**   This function is used, along with type Fts5PhraseIter and the xPhraseNext
+**   method, to iterate through all instances of a single query phrase within
+**   the current row. This is the same information as is accessible via the
+**   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
+**   to use, this API may be faster under some circumstances. To iterate 
+**   through instances of phrase iPhrase, use the following code:
+**
+**       Fts5PhraseIter iter;
+**       int iCol, iOff;
+**       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
+**           iCol>=0;
+**           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
+**       ){
+**         // An instance of phrase iPhrase at offset iOff of column iCol
+**       }
+**
+**   The Fts5PhraseIter structure is defined above. Applications should not
+**   modify this structure directly - it should only be used as shown above
+**   with the xPhraseFirst() and xPhraseNext() API methods (and by
+**   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" or "detail=column" option. If the FTS5 table is created 
+**   with either "detail=none" or "detail=column" and "content=" option 
+**   (i.e. if it is a contentless table), then this API always iterates
+**   through an empty set (all calls to xPhraseFirst() set iCol to -1).
+**
+** xPhraseNext()
+**   See xPhraseFirst above.
+**
+** xPhraseFirstColumn()
+**   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
+**   and xPhraseNext() APIs described above. The difference is that instead
+**   of iterating through all instances of a phrase in the current row, these
+**   APIs are used to iterate through the set of columns in the current row
+**   that contain one or more instances of a specified phrase. For example:
+**
+**       Fts5PhraseIter iter;
+**       int iCol;
+**       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
+**           iCol>=0;
+**           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
+**       ){
+**         // Column iCol contains at least one instance of phrase iPhrase
+**       }
+**
+**   This API can be quite slow if used with an FTS5 table created with the
+**   "detail=none" option. If the FTS5 table is created with either 
+**   "detail=none" "content=" option (i.e. if it is a contentless table), 
+**   then this API always iterates through an empty set (all calls to 
+**   xPhraseFirstColumn() set iCol to -1).
+**
+**   The information accessed using this API and its companion
+**   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
+**   (or xInst/xInstCount). The chief advantage of this API is that it is
+**   significantly more efficient than those alternatives when used with
+**   "detail=column" tables.  
+**
+** xPhraseNextColumn()
+**   See xPhraseFirstColumn above.
+*/
+struct Fts5ExtensionApi {
+  int iVersion;                   /* Currently always set to 3 */
+
+  void *(*xUserData)(Fts5Context*);
+
+  int (*xColumnCount)(Fts5Context*);
+  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
+  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
+
+  int (*xTokenize)(Fts5Context*, 
+    const char *pText, int nText, /* Text to tokenize */
+    void *pCtx,                   /* Context passed to xToken() */
+    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
+  );
+
+  int (*xPhraseCount)(Fts5Context*);
+  int (*xPhraseSize)(Fts5Context*, int iPhrase);
+
+  int (*xInstCount)(Fts5Context*, int *pnInst);
+  int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
+
+  sqlite3_int64 (*xRowid)(Fts5Context*);
+  int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
+  int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
+
+  int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
+    int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
+  );
+  int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
+  void *(*xGetAuxdata)(Fts5Context*, int bClear);
+
+  int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
+  void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
+
+  int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
+  void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
+};
+
+/* 
+** CUSTOM AUXILIARY FUNCTIONS
+*************************************************************************/
+
+/*************************************************************************
+** CUSTOM TOKENIZERS
+**
+** Applications may also register custom tokenizer types. A tokenizer 
+** is registered by providing fts5 with a populated instance of the 
+** following structure. All structure methods must be defined, setting
+** any member of the fts5_tokenizer struct to NULL leads to undefined
+** behaviour. The structure methods are expected to function as follows:
+**
+** xCreate:
+**   This function is used to allocate and initialize a tokenizer instance.
+**   A tokenizer instance is required to actually tokenize text.
+**
+**   The first argument passed to this function is a copy of the (void*)
+**   pointer provided by the application when the fts5_tokenizer object
+**   was registered with FTS5 (the third argument to xCreateTokenizer()). 
+**   The second and third arguments are an array of nul-terminated strings
+**   containing the tokenizer arguments, if any, specified following the
+**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
+**   to create the FTS5 table.
+**
+**   The final argument is an output variable. If successful, (*ppOut) 
+**   should be set to point to the new tokenizer handle and SQLITE_OK
+**   returned. If an error occurs, some value other than SQLITE_OK should
+**   be returned. In this case, fts5 assumes that the final value of *ppOut 
+**   is undefined.
+**
+** xDelete:
+**   This function is invoked to delete a tokenizer handle previously
+**   allocated using xCreate(). Fts5 guarantees that this function will
+**   be invoked exactly once for each successful call to xCreate().
+**
+** xTokenize:
+**   This function is expected to tokenize the nText byte string indicated 
+**   by argument pText. pText may or may not be nul-terminated. The first
+**   argument passed to this function is a pointer to an Fts5Tokenizer object
+**   returned by an earlier call to xCreate().
+**
+**   The second argument indicates the reason that FTS5 is requesting
+**   tokenization of the supplied text. This is always one of the following
+**   four values:
+**
+**   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
+**            or removed from the FTS table. The tokenizer is being invoked to
+**            determine the set of tokens to add to (or delete from) the
+**            FTS index.
+**
+**       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 
+**            against the FTS index. The tokenizer is being called to tokenize 
+**            a bareword or quoted string specified as part of the query.
+**
+**       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
+**            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
+**            followed by a "*" character, indicating that the last token
+**            returned by the tokenizer will be treated as a token prefix.
+**
+**       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 
+**            satisfy an fts5_api.xTokenize() request made by an auxiliary
+**            function. Or an fts5_api.xColumnSize() request made by the same
+**            on a columnsize=0 database.  
+**   </ul>
+**
+**   For each token in the input string, the supplied callback xToken() must
+**   be invoked. The first argument to it should be a copy of the pointer
+**   passed as the second argument to xTokenize(). The third and fourth
+**   arguments are a pointer to a buffer containing the token text, and the
+**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
+**   of the first byte of and first byte immediately following the text from
+**   which the token is derived within the input.
+**
+**   The second argument passed to the xToken() callback ("tflags") should
+**   normally be set to 0. The exception is if the tokenizer supports 
+**   synonyms. In this case see the discussion below for details.
+**
+**   FTS5 assumes the xToken() callback is invoked for each token in the 
+**   order that they occur within the input text.
+**
+**   If an xToken() callback returns any value other than SQLITE_OK, then
+**   the tokenization should be abandoned and the xTokenize() method should
+**   immediately return a copy of the xToken() return value. Or, if the
+**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
+**   if an error occurs with the xTokenize() implementation itself, it
+**   may abandon the tokenization and return any error code other than
+**   SQLITE_OK or SQLITE_DONE.
+**
+** SYNONYM SUPPORT
+**
+**   Custom tokenizers may also support synonyms. Consider a case in which a
+**   user wishes to query for a phrase such as "first place". Using the 
+**   built-in tokenizers, the FTS5 query 'first + place' will match instances
+**   of "first place" within the document set, but not alternative forms
+**   such as "1st place". In some applications, it would be better to match
+**   all instances of "first place" or "1st place" regardless of which form
+**   the user specified in the MATCH query text.
+**
+**   There are several ways to approach this in FTS5:
+**
+**   <ol><li> By mapping all synonyms to a single token. In this case, the 
+**            In the above example, this means that the tokenizer returns the
+**            same token for inputs "first" and "1st". Say that token is in
+**            fact "first", so that when the user inserts the document "I won
+**            1st place" entries are added to the index for tokens "i", "won",
+**            "first" and "place". If the user then queries for '1st + place',
+**            the tokenizer substitutes "first" for "1st" and the query works
+**            as expected.
+**
+**       <li> By adding multiple synonyms for a single term to the FTS index.
+**            In this case, when tokenizing query text, the tokenizer may 
+**            provide multiple synonyms for a single term within the document.
+**            FTS5 then queries the index for each synonym individually. For
+**            example, faced with the query:
+**
+**   <codeblock>
+**     ... MATCH 'first place'</codeblock>
+**
+**            the tokenizer offers both "1st" and "first" as synonyms for the
+**            first token in the MATCH query and FTS5 effectively runs a query 
+**            similar to:
+**
+**   <codeblock>
+**     ... MATCH '(first OR 1st) place'</codeblock>
+**
+**            except that, for the purposes of auxiliary functions, the query
+**            still appears to contain just two phrases - "(first OR 1st)" 
+**            being treated as a single phrase.
+**
+**       <li> By adding multiple synonyms for a single term to the FTS index.
+**            Using this method, when tokenizing document text, the tokenizer
+**            provides multiple synonyms for each token. So that when a 
+**            document such as "I won first place" is tokenized, entries are
+**            added to the FTS index for "i", "won", "first", "1st" and
+**            "place".
+**
+**            This way, even if the tokenizer does not provide synonyms
+**            when tokenizing query text (it should not - to do would be
+**            inefficient), it doesn't matter if the user queries for 
+**            'first + place' or '1st + place', as there are entires in the
+**            FTS index corresponding to both forms of the first token.
+**   </ol>
+**
+**   Whether it is parsing document or query text, any call to xToken that
+**   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
+**   is considered to supply a synonym for the previous token. For example,
+**   when parsing the document "I won first place", a tokenizer that supports
+**   synonyms would call xToken() 5 times, as follows:
+**
+**   <codeblock>
+**       xToken(pCtx, 0, "i",                      1,  0,  1);
+**       xToken(pCtx, 0, "won",                    3,  2,  5);
+**       xToken(pCtx, 0, "first",                  5,  6, 11);
+**       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
+**       xToken(pCtx, 0, "place",                  5, 12, 17);
+**</codeblock>
+**
+**   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
+**   xToken() is called. Multiple synonyms may be specified for a single token
+**   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 
+**   There is no limit to the number of synonyms that may be provided for a
+**   single token.
+**
+**   In many cases, method (1) above is the best approach. It does not add 
+**   extra data to the FTS index or require FTS5 to query for multiple terms,
+**   so it is efficient in terms of disk space and query speed. However, it
+**   does not support prefix queries very well. If, as suggested above, the
+**   token "first" is subsituted for "1st" by the tokenizer, then the query:
+**
+**   <codeblock>
+**     ... MATCH '1s*'</codeblock>
+**
+**   will not match documents that contain the token "1st" (as the tokenizer
+**   will probably not map "1s" to any prefix of "first").
+**
+**   For full prefix support, method (3) may be preferred. In this case, 
+**   because the index contains entries for both "first" and "1st", prefix
+**   queries such as 'fi*' or '1s*' will match correctly. However, because
+**   extra entries are added to the FTS index, this method uses more space
+**   within the database.
+**
+**   Method (2) offers a midpoint between (1) and (3). Using this method,
+**   a query such as '1s*' will match documents that contain the literal 
+**   token "1st", but not "first" (assuming the tokenizer is not able to
+**   provide synonyms for prefixes). However, a non-prefix query like '1st'
+**   will match against "1st" and "first". This method does not require
+**   extra disk space, as no extra entries are added to the FTS index. 
+**   On the other hand, it may require more CPU cycles to run MATCH queries,
+**   as separate queries of the FTS index are required for each synonym.
+**
+**   When using methods (2) or (3), it is important that the tokenizer only
+**   provide synonyms when tokenizing document text (method (2)) or query
+**   text (method (3)), not both. Doing so will not cause any errors, but is
+**   inefficient.
+*/
+typedef struct Fts5Tokenizer Fts5Tokenizer;
+typedef struct fts5_tokenizer fts5_tokenizer;
+struct fts5_tokenizer {
+  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
+  void (*xDelete)(Fts5Tokenizer*);
+  int (*xTokenize)(Fts5Tokenizer*, 
+      void *pCtx,
+      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
+      const char *pText, int nText, 
+      int (*xToken)(
+        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
+        int tflags,         /* Mask of FTS5_TOKEN_* flags */
+        const char *pToken, /* Pointer to buffer containing token */
+        int nToken,         /* Size of token in bytes */
+        int iStart,         /* Byte offset of token within input text */
+        int iEnd            /* Byte offset of end of token within input text */
+      )
+  );
+};
+
+/* Flags that may be passed as the third argument to xTokenize() */
+#define FTS5_TOKENIZE_QUERY     0x0001
+#define FTS5_TOKENIZE_PREFIX    0x0002
+#define FTS5_TOKENIZE_DOCUMENT  0x0004
+#define FTS5_TOKENIZE_AUX       0x0008
+
+/* Flags that may be passed by the tokenizer implementation back to FTS5
+** as the third argument to the supplied xToken callback. */
+#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */
+
+/*
+** END OF CUSTOM TOKENIZERS
+*************************************************************************/
+
+/*************************************************************************
+** FTS5 EXTENSION REGISTRATION API
+*/
+typedef struct fts5_api fts5_api;
+struct fts5_api {
+  int iVersion;                   /* Currently always set to 2 */
+
+  /* Create a new tokenizer */
+  int (*xCreateTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_tokenizer *pTokenizer,
+    void (*xDestroy)(void*)
+  );
+
+  /* Find an existing tokenizer */
+  int (*xFindTokenizer)(
+    fts5_api *pApi,
+    const char *zName,
+    void **ppContext,
+    fts5_tokenizer *pTokenizer
+  );
+
+  /* Create a new auxiliary function */
+  int (*xCreateFunction)(
+    fts5_api *pApi,
+    const char *zName,
+    void *pContext,
+    fts5_extension_function xFunction,
+    void (*xDestroy)(void*)
+  );
+};
+
+/*
+** END OF REGISTRATION API
+*************************************************************************/
+
+#if 0
+}  /* end of the 'extern "C"' block */
+#endif
+
+#endif /* _FTS5_H */
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+#ifndef _FTS5INT_H
+#define _FTS5INT_H
+
+/* #include "fts5.h" */
+/* #include "sqlite3ext.h" */
+SQLITE_EXTENSION_INIT1
+
+/* #include <string.h> */
+/* #include <assert.h> */
+
+#ifndef SQLITE_AMALGAMATION
+
+typedef unsigned char  u8;
+typedef unsigned int   u32;
+typedef unsigned short u16;
+typedef short i16;
+typedef sqlite3_int64 i64;
+typedef sqlite3_uint64 u64;
+
+#define ArraySize(x) ((int)(sizeof(x) / sizeof(x[0])))
+
+#define testcase(x)
+#define ALWAYS(x) 1
+#define NEVER(x) 0
+
+#define MIN(x,y) (((x) < (y)) ? (x) : (y))
+#define MAX(x,y) (((x) > (y)) ? (x) : (y))
+
+/*
+** Constants for the largest and smallest possible 64-bit signed integers.
+*/
+# define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
+# define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
+
+#endif
+
+/* Truncate very long tokens to this many bytes. Hard limit is 
+** (65536-1-1-4-9)==65521 bytes. The limiting factor is the 16-bit offset
+** field that occurs at the start of each leaf page (see fts5_index.c). */
+#define FTS5_MAX_TOKEN_SIZE 32768
+
+/*
+** Maximum number of prefix indexes on single FTS5 table. This must be
+** less than 32. If it is set to anything large than that, an #error
+** directive in fts5_index.c will cause the build to fail.
+*/
+#define FTS5_MAX_PREFIX_INDEXES 31
+
+#define FTS5_DEFAULT_NEARDIST 10
+#define FTS5_DEFAULT_RANK     "bm25"
+
+/* Name of rank and rowid columns */
+#define FTS5_RANK_NAME "rank"
+#define FTS5_ROWID_NAME "rowid"
+
+#ifdef SQLITE_DEBUG
+# define FTS5_CORRUPT sqlite3Fts5Corrupt()
+static int sqlite3Fts5Corrupt(void);
+#else
+# define FTS5_CORRUPT SQLITE_CORRUPT_VTAB
+#endif
+
+/*
+** The assert_nc() macro is similar to the assert() macro, except that it
+** is used for assert() conditions that are true only if it can be 
+** guranteed that the database is not corrupt.
+*/
+#ifdef SQLITE_DEBUG
+SQLITE_API extern int sqlite3_fts5_may_be_corrupt;
+# define assert_nc(x) assert(sqlite3_fts5_may_be_corrupt || (x))
+#else
+# define assert_nc(x) assert(x)
+#endif
+
+/* Mark a function parameter as unused, to suppress nuisance compiler
+** warnings. */
+#ifndef UNUSED_PARAM
+# define UNUSED_PARAM(X)  (void)(X)
+#endif
+
+#ifndef UNUSED_PARAM2
+# define UNUSED_PARAM2(X, Y)  (void)(X), (void)(Y)
+#endif
+
+typedef struct Fts5Global Fts5Global;
+typedef struct Fts5Colset Fts5Colset;
+
+/* If a NEAR() clump or phrase may only match a specific set of columns, 
+** then an object of the following type is used to record the set of columns.
+** Each entry in the aiCol[] array is a column that may be matched.
+**
+** This object is used by fts5_expr.c and fts5_index.c.
+*/
+struct Fts5Colset {
+  int nCol;
+  int aiCol[1];
+};
+
+
+
+/**************************************************************************
+** Interface to code in fts5_config.c. fts5_config.c contains contains code
+** to parse the arguments passed to the CREATE VIRTUAL TABLE statement.
+*/
+
+typedef struct Fts5Config Fts5Config;
+
+/*
+** An instance of the following structure encodes all information that can
+** be gleaned from the CREATE VIRTUAL TABLE statement.
+**
+** And all information loaded from the %_config table.
+**
+** nAutomerge:
+**   The minimum number of segments that an auto-merge operation should
+**   attempt to merge together. A value of 1 sets the object to use the 
+**   compile time default. Zero disables auto-merge altogether.
+**
+** zContent:
+**
+** zContentRowid:
+**   The value of the content_rowid= option, if one was specified. Or 
+**   the string "rowid" otherwise. This text is not quoted - if it is
+**   used as part of an SQL statement it needs to be quoted appropriately.
+**
+** zContentExprlist:
+**
+** pzErrmsg:
+**   This exists in order to allow the fts5_index.c module to return a 
+**   decent error message if it encounters a file-format version it does
+**   not understand.
+**
+** bColumnsize:
+**   True if the %_docsize table is created.
+**
+** bPrefixIndex:
+**   This is only used for debugging. If set to false, any prefix indexes
+**   are ignored. This value is configured using:
+**
+**       INSERT INTO tbl(tbl, rank) VALUES('prefix-index', $bPrefixIndex);
+**
+*/
+struct Fts5Config {
+  sqlite3 *db;                    /* Database handle */
+  char *zDb;                      /* Database holding FTS index (e.g. "main") */
+  char *zName;                    /* Name of FTS index */
+  int nCol;                       /* Number of columns */
+  char **azCol;                   /* Column names */
+  u8 *abUnindexed;                /* True for unindexed columns */
+  int nPrefix;                    /* Number of prefix indexes */
+  int *aPrefix;                   /* Sizes in bytes of nPrefix prefix indexes */
+  int eContent;                   /* An FTS5_CONTENT value */
+  char *zContent;                 /* content table */ 
+  char *zContentRowid;            /* "content_rowid=" option value */ 
+  int bColumnsize;                /* "columnsize=" option value (dflt==1) */
+  int eDetail;                    /* FTS5_DETAIL_XXX value */
+  char *zContentExprlist;
+  Fts5Tokenizer *pTok;
+  fts5_tokenizer *pTokApi;
+
+  /* Values loaded from the %_config table */
+  int iCookie;                    /* Incremented when %_config is modified */
+  int pgsz;                       /* Approximate page size used in %_data */
+  int nAutomerge;                 /* 'automerge' setting */
+  int nCrisisMerge;               /* Maximum allowed segments per level */
+  int nUsermerge;                 /* 'usermerge' setting */
+  int nHashSize;                  /* Bytes of memory for in-memory hash */
+  char *zRank;                    /* Name of rank function */
+  char *zRankArgs;                /* Arguments to rank function */
+
+  /* If non-NULL, points to sqlite3_vtab.base.zErrmsg. Often NULL. */
+  char **pzErrmsg;
+
+#ifdef SQLITE_DEBUG
+  int bPrefixIndex;               /* True to use prefix-indexes */
+#endif
+};
+
+/* Current expected value of %_config table 'version' field */
+#define FTS5_CURRENT_VERSION 4
+
+#define FTS5_CONTENT_NORMAL   0
+#define FTS5_CONTENT_NONE     1
+#define FTS5_CONTENT_EXTERNAL 2
+
+#define FTS5_DETAIL_FULL    0
+#define FTS5_DETAIL_NONE    1
+#define FTS5_DETAIL_COLUMNS 2
+
+
+
+static int sqlite3Fts5ConfigParse(
+    Fts5Global*, sqlite3*, int, const char **, Fts5Config**, char**
+);
+static void sqlite3Fts5ConfigFree(Fts5Config*);
+
+static int sqlite3Fts5ConfigDeclareVtab(Fts5Config *pConfig);
+
+static int sqlite3Fts5Tokenize(
+  Fts5Config *pConfig,            /* FTS5 Configuration object */
+  int flags,                      /* FTS5_TOKENIZE_* flags */
+  const char *pText, int nText,   /* Text to tokenize */
+  void *pCtx,                     /* Context passed to xToken() */
+  int (*xToken)(void*, int, const char*, int, int, int)    /* Callback */
+);
+
+static void sqlite3Fts5Dequote(char *z);
+
+/* Load the contents of the %_config table */
+static int sqlite3Fts5ConfigLoad(Fts5Config*, int);
+
+/* Set the value of a single config attribute */
+static int sqlite3Fts5ConfigSetValue(Fts5Config*, const char*, sqlite3_value*, int*);
+
+static int sqlite3Fts5ConfigParseRank(const char*, char**, char**);
+
+/*
+** End of interface to code in fts5_config.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_buffer.c.
+*/
+
+/*
+** Buffer object for the incremental building of string data.
+*/
+typedef struct Fts5Buffer Fts5Buffer;
+struct Fts5Buffer {
+  u8 *p;
+  int n;
+  int nSpace;
+};
+
+static int sqlite3Fts5BufferSize(int*, Fts5Buffer*, u32);
+static void sqlite3Fts5BufferAppendVarint(int*, Fts5Buffer*, i64);
+static void sqlite3Fts5BufferAppendBlob(int*, Fts5Buffer*, u32, const u8*);
+static void sqlite3Fts5BufferAppendString(int *, Fts5Buffer*, const char*);
+static void sqlite3Fts5BufferFree(Fts5Buffer*);
+static void sqlite3Fts5BufferZero(Fts5Buffer*);
+static void sqlite3Fts5BufferSet(int*, Fts5Buffer*, int, const u8*);
+static void sqlite3Fts5BufferAppendPrintf(int *, Fts5Buffer*, char *zFmt, ...);
+
+static char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...);
+
+#define fts5BufferZero(x)             sqlite3Fts5BufferZero(x)
+#define fts5BufferAppendVarint(a,b,c) sqlite3Fts5BufferAppendVarint(a,b,c)
+#define fts5BufferFree(a)             sqlite3Fts5BufferFree(a)
+#define fts5BufferAppendBlob(a,b,c,d) sqlite3Fts5BufferAppendBlob(a,b,c,d)
+#define fts5BufferSet(a,b,c,d)        sqlite3Fts5BufferSet(a,b,c,d)
+
+#define fts5BufferGrow(pRc,pBuf,nn) ( \
+  (u32)((pBuf)->n) + (u32)(nn) <= (u32)((pBuf)->nSpace) ? 0 : \
+    sqlite3Fts5BufferSize((pRc),(pBuf),(nn)+(pBuf)->n) \
+)
+
+/* Write and decode big-endian 32-bit integer values */
+static void sqlite3Fts5Put32(u8*, int);
+static int sqlite3Fts5Get32(const u8*);
+
+#define FTS5_POS2COLUMN(iPos) (int)(iPos >> 32)
+#define FTS5_POS2OFFSET(iPos) (int)(iPos & 0xFFFFFFFF)
+
+typedef struct Fts5PoslistReader Fts5PoslistReader;
+struct Fts5PoslistReader {
+  /* Variables used only by sqlite3Fts5PoslistIterXXX() functions. */
+  const u8 *a;                    /* Position list to iterate through */
+  int n;                          /* Size of buffer at a[] in bytes */
+  int i;                          /* Current offset in a[] */
+
+  u8 bFlag;                       /* For client use (any custom purpose) */
+
+  /* Output variables */
+  u8 bEof;                        /* Set to true at EOF */
+  i64 iPos;                       /* (iCol<<32) + iPos */
+};
+static int sqlite3Fts5PoslistReaderInit(
+  const u8 *a, int n,             /* Poslist buffer to iterate through */
+  Fts5PoslistReader *pIter        /* Iterator object to initialize */
+);
+static int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader*);
+
+typedef struct Fts5PoslistWriter Fts5PoslistWriter;
+struct Fts5PoslistWriter {
+  i64 iPrev;
+};
+static int sqlite3Fts5PoslistWriterAppend(Fts5Buffer*, Fts5PoslistWriter*, i64);
+static void sqlite3Fts5PoslistSafeAppend(Fts5Buffer*, i64*, i64);
+
+static int sqlite3Fts5PoslistNext64(
+  const u8 *a, int n,             /* Buffer containing poslist */
+  int *pi,                        /* IN/OUT: Offset within a[] */
+  i64 *piOff                      /* IN/OUT: Current offset */
+);
+
+/* Malloc utility */
+static void *sqlite3Fts5MallocZero(int *pRc, int nByte);
+static char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn);
+
+/* Character set tests (like isspace(), isalpha() etc.) */
+static int sqlite3Fts5IsBareword(char t);
+
+
+/* Bucket of terms object used by the integrity-check in offsets=0 mode. */
+typedef struct Fts5Termset Fts5Termset;
+static int sqlite3Fts5TermsetNew(Fts5Termset**);
+static int sqlite3Fts5TermsetAdd(Fts5Termset*, int, const char*, int, int *pbPresent);
+static void sqlite3Fts5TermsetFree(Fts5Termset*);
+
+/*
+** End of interface to code in fts5_buffer.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_index.c. fts5_index.c contains contains code
+** to access the data stored in the %_data table.
+*/
+
+typedef struct Fts5Index Fts5Index;
+typedef struct Fts5IndexIter Fts5IndexIter;
+
+struct Fts5IndexIter {
+  i64 iRowid;
+  const u8 *pData;
+  int nData;
+  u8 bEof;
+};
+
+#define sqlite3Fts5IterEof(x) ((x)->bEof)
+
+/*
+** Values used as part of the flags argument passed to IndexQuery().
+*/
+#define FTS5INDEX_QUERY_PREFIX     0x0001   /* Prefix query */
+#define FTS5INDEX_QUERY_DESC       0x0002   /* Docs in descending rowid order */
+#define FTS5INDEX_QUERY_TEST_NOIDX 0x0004   /* Do not use prefix index */
+#define FTS5INDEX_QUERY_SCAN       0x0008   /* Scan query (fts5vocab) */
+
+/* The following are used internally by the fts5_index.c module. They are
+** defined here only to make it easier to avoid clashes with the flags
+** above. */
+#define FTS5INDEX_QUERY_SKIPEMPTY  0x0010
+#define FTS5INDEX_QUERY_NOOUTPUT   0x0020
+
+/*
+** Create/destroy an Fts5Index object.
+*/
+static int sqlite3Fts5IndexOpen(Fts5Config *pConfig, int bCreate, Fts5Index**, char**);
+static int sqlite3Fts5IndexClose(Fts5Index *p);
+
+/*
+** Return a simple checksum value based on the arguments.
+*/
+static u64 sqlite3Fts5IndexEntryCksum(
+  i64 iRowid, 
+  int iCol, 
+  int iPos, 
+  int iIdx,
+  const char *pTerm,
+  int nTerm
+);
+
+/*
+** Argument p points to a buffer containing utf-8 text that is n bytes in 
+** size. Return the number of bytes in the nChar character prefix of the
+** buffer, or 0 if there are less than nChar characters in total.
+*/
+static int sqlite3Fts5IndexCharlenToBytelen(
+  const char *p, 
+  int nByte, 
+  int nChar
+);
+
+/*
+** Open a new iterator to iterate though all rowids that match the 
+** specified token or token prefix.
+*/
+static int sqlite3Fts5IndexQuery(
+  Fts5Index *p,                   /* FTS index to query */
+  const char *pToken, int nToken, /* Token (or prefix) to query for */
+  int flags,                      /* Mask of FTS5INDEX_QUERY_X flags */
+  Fts5Colset *pColset,            /* Match these columns only */
+  Fts5IndexIter **ppIter          /* OUT: New iterator object */
+);
+
+/*
+** The various operations on open token or token prefix iterators opened
+** using sqlite3Fts5IndexQuery().
+*/
+static int sqlite3Fts5IterNext(Fts5IndexIter*);
+static int sqlite3Fts5IterNextFrom(Fts5IndexIter*, i64 iMatch);
+
+/*
+** Close an iterator opened by sqlite3Fts5IndexQuery().
+*/
+static void sqlite3Fts5IterClose(Fts5IndexIter*);
+
+/*
+** This interface is used by the fts5vocab module.
+*/
+static const char *sqlite3Fts5IterTerm(Fts5IndexIter*, int*);
+static int sqlite3Fts5IterNextScan(Fts5IndexIter*);
+
+
+/*
+** Insert or remove data to or from the index. Each time a document is 
+** added to or removed from the index, this function is called one or more
+** times.
+**
+** For an insert, it must be called once for each token in the new document.
+** If the operation is a delete, it must be called (at least) once for each
+** unique token in the document with an iCol value less than zero. The iPos
+** argument is ignored for a delete.
+*/
+static int sqlite3Fts5IndexWrite(
+  Fts5Index *p,                   /* Index to write to */
+  int iCol,                       /* Column token appears in (-ve -> delete) */
+  int iPos,                       /* Position of token within column */
+  const char *pToken, int nToken  /* Token to add or remove to or from index */
+);
+
+/*
+** Indicate that subsequent calls to sqlite3Fts5IndexWrite() pertain to
+** document iDocid.
+*/
+static int sqlite3Fts5IndexBeginWrite(
+  Fts5Index *p,                   /* Index to write to */
+  int bDelete,                    /* True if current operation is a delete */
+  i64 iDocid                      /* Docid to add or remove data from */
+);
+
+/*
+** Flush any data stored in the in-memory hash tables to the database.
+** If the bCommit flag is true, also close any open blob handles.
+*/
+static int sqlite3Fts5IndexSync(Fts5Index *p, int bCommit);
+
+/*
+** Discard any data stored in the in-memory hash tables. Do not write it
+** to the database. Additionally, assume that the contents of the %_data
+** table may have changed on disk. So any in-memory caches of %_data 
+** records must be invalidated.
+*/
+static int sqlite3Fts5IndexRollback(Fts5Index *p);
+
+/*
+** Get or set the "averages" values.
+*/
+static int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize);
+static int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);
+
+/*
+** Functions called by the storage module as part of integrity-check.
+*/
+static int sqlite3Fts5IndexIntegrityCheck(Fts5Index*, u64 cksum);
+
+/* 
+** Called during virtual module initialization to register UDF 
+** fts5_decode() with SQLite 
+*/
+static int sqlite3Fts5IndexInit(sqlite3*);
+
+static int sqlite3Fts5IndexSetCookie(Fts5Index*, int);
+
+/*
+** Return the total number of entries read from the %_data table by 
+** this connection since it was created.
+*/
+static int sqlite3Fts5IndexReads(Fts5Index *p);
+
+static int sqlite3Fts5IndexReinit(Fts5Index *p);
+static int sqlite3Fts5IndexOptimize(Fts5Index *p);
+static int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge);
+static int sqlite3Fts5IndexReset(Fts5Index *p);
+
+static int sqlite3Fts5IndexLoadConfig(Fts5Index *p);
+
+/*
+** End of interface to code in fts5_index.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_varint.c. 
+*/
+static int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v);
+static int sqlite3Fts5GetVarintLen(u32 iVal);
+static u8 sqlite3Fts5GetVarint(const unsigned char*, u64*);
+static int sqlite3Fts5PutVarint(unsigned char *p, u64 v);
+
+#define fts5GetVarint32(a,b) sqlite3Fts5GetVarint32(a,(u32*)&b)
+#define fts5GetVarint    sqlite3Fts5GetVarint
+
+#define fts5FastGetVarint32(a, iOff, nVal) {      \
+  nVal = (a)[iOff++];                             \
+  if( nVal & 0x80 ){                              \
+    iOff--;                                       \
+    iOff += fts5GetVarint32(&(a)[iOff], nVal);    \
+  }                                               \
+}
+
+
+/*
+** End of interface to code in fts5_varint.c.
+**************************************************************************/
+
+
+/**************************************************************************
+** Interface to code in fts5.c. 
+*/
+
+static int sqlite3Fts5GetTokenizer(
+  Fts5Global*, 
+  const char **azArg,
+  int nArg,
+  Fts5Tokenizer**,
+  fts5_tokenizer**,
+  char **pzErr
+);
+
+static Fts5Index *sqlite3Fts5IndexFromCsrid(Fts5Global*, i64, Fts5Config **);
+
+/*
+** End of interface to code in fts5.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_hash.c. 
+*/
+typedef struct Fts5Hash Fts5Hash;
+
+/*
+** Create a hash table, free a hash table.
+*/
+static int sqlite3Fts5HashNew(Fts5Config*, Fts5Hash**, int *pnSize);
+static void sqlite3Fts5HashFree(Fts5Hash*);
+
+static int sqlite3Fts5HashWrite(
+  Fts5Hash*,
+  i64 iRowid,                     /* Rowid for this entry */
+  int iCol,                       /* Column token appears in (-ve -> delete) */
+  int iPos,                       /* Position of token within column */
+  char bByte,
+  const char *pToken, int nToken  /* Token to add or remove to or from index */
+);
+
+/*
+** Empty (but do not delete) a hash table.
+*/
+static void sqlite3Fts5HashClear(Fts5Hash*);
+
+static int sqlite3Fts5HashQuery(
+  Fts5Hash*,                      /* Hash table to query */
+  const char *pTerm, int nTerm,   /* Query term */
+  const u8 **ppDoclist,           /* OUT: Pointer to doclist for pTerm */
+  int *pnDoclist                  /* OUT: Size of doclist in bytes */
+);
+
+static int sqlite3Fts5HashScanInit(
+  Fts5Hash*,                      /* Hash table to query */
+  const char *pTerm, int nTerm    /* Query prefix */
+);
+static void sqlite3Fts5HashScanNext(Fts5Hash*);
+static int sqlite3Fts5HashScanEof(Fts5Hash*);
+static void sqlite3Fts5HashScanEntry(Fts5Hash *,
+  const char **pzTerm,            /* OUT: term (nul-terminated) */
+  const u8 **ppDoclist,           /* OUT: pointer to doclist */
+  int *pnDoclist                  /* OUT: size of doclist in bytes */
+);
+
+
+/*
+** End of interface to code in fts5_hash.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_storage.c. fts5_storage.c contains contains 
+** code to access the data stored in the %_content and %_docsize tables.
+*/
+
+#define FTS5_STMT_SCAN_ASC  0     /* SELECT rowid, * FROM ... ORDER BY 1 ASC */
+#define FTS5_STMT_SCAN_DESC 1     /* SELECT rowid, * FROM ... ORDER BY 1 DESC */
+#define FTS5_STMT_LOOKUP    2     /* SELECT rowid, * FROM ... WHERE rowid=? */
+
+typedef struct Fts5Storage Fts5Storage;
+
+static int sqlite3Fts5StorageOpen(Fts5Config*, Fts5Index*, int, Fts5Storage**, char**);
+static int sqlite3Fts5StorageClose(Fts5Storage *p);
+static int sqlite3Fts5StorageRename(Fts5Storage*, const char *zName);
+
+static int sqlite3Fts5DropAll(Fts5Config*);
+static int sqlite3Fts5CreateTable(Fts5Config*, const char*, const char*, int, char **);
+
+static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64, sqlite3_value**);
+static int sqlite3Fts5StorageContentInsert(Fts5Storage *p, sqlite3_value**, i64*);
+static int sqlite3Fts5StorageIndexInsert(Fts5Storage *p, sqlite3_value**, i64);
+
+static int sqlite3Fts5StorageIntegrity(Fts5Storage *p);
+
+static int sqlite3Fts5StorageStmt(Fts5Storage *p, int eStmt, sqlite3_stmt**, char**);
+static void sqlite3Fts5StorageStmtRelease(Fts5Storage *p, int eStmt, sqlite3_stmt*);
+
+static int sqlite3Fts5StorageDocsize(Fts5Storage *p, i64 iRowid, int *aCol);
+static int sqlite3Fts5StorageSize(Fts5Storage *p, int iCol, i64 *pnAvg);
+static int sqlite3Fts5StorageRowCount(Fts5Storage *p, i64 *pnRow);
+
+static int sqlite3Fts5StorageSync(Fts5Storage *p, int bCommit);
+static int sqlite3Fts5StorageRollback(Fts5Storage *p);
+
+static int sqlite3Fts5StorageConfigValue(
+    Fts5Storage *p, const char*, sqlite3_value*, int
+);
+
+static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);
+static int sqlite3Fts5StorageRebuild(Fts5Storage *p);
+static int sqlite3Fts5StorageOptimize(Fts5Storage *p);
+static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge);
+static int sqlite3Fts5StorageReset(Fts5Storage *p);
+
+/*
+** End of interface to code in fts5_storage.c.
+**************************************************************************/
+
+
+/**************************************************************************
+** Interface to code in fts5_expr.c. 
+*/
+typedef struct Fts5Expr Fts5Expr;
+typedef struct Fts5ExprNode Fts5ExprNode;
+typedef struct Fts5Parse Fts5Parse;
+typedef struct Fts5Token Fts5Token;
+typedef struct Fts5ExprPhrase Fts5ExprPhrase;
+typedef struct Fts5ExprNearset Fts5ExprNearset;
+
+struct Fts5Token {
+  const char *p;                  /* Token text (not NULL terminated) */
+  int n;                          /* Size of buffer p in bytes */
+};
+
+/* Parse a MATCH expression. */
+static int sqlite3Fts5ExprNew(
+  Fts5Config *pConfig, 
+  const char *zExpr,
+  Fts5Expr **ppNew, 
+  char **pzErr
+);
+
+/*
+** for(rc = sqlite3Fts5ExprFirst(pExpr, pIdx, bDesc);
+**     rc==SQLITE_OK && 0==sqlite3Fts5ExprEof(pExpr);
+**     rc = sqlite3Fts5ExprNext(pExpr)
+** ){
+**   // The document with rowid iRowid matches the expression!
+**   i64 iRowid = sqlite3Fts5ExprRowid(pExpr);
+** }
+*/
+static int sqlite3Fts5ExprFirst(Fts5Expr*, Fts5Index *pIdx, i64 iMin, int bDesc);
+static int sqlite3Fts5ExprNext(Fts5Expr*, i64 iMax);
+static int sqlite3Fts5ExprEof(Fts5Expr*);
+static i64 sqlite3Fts5ExprRowid(Fts5Expr*);
+
+static void sqlite3Fts5ExprFree(Fts5Expr*);
+
+/* Called during startup to register a UDF with SQLite */
+static int sqlite3Fts5ExprInit(Fts5Global*, sqlite3*);
+
+static int sqlite3Fts5ExprPhraseCount(Fts5Expr*);
+static int sqlite3Fts5ExprPhraseSize(Fts5Expr*, int iPhrase);
+static int sqlite3Fts5ExprPoslist(Fts5Expr*, int, const u8 **);
+
+typedef struct Fts5PoslistPopulator Fts5PoslistPopulator;
+static Fts5PoslistPopulator *sqlite3Fts5ExprClearPoslists(Fts5Expr*, int);
+static int sqlite3Fts5ExprPopulatePoslists(
+    Fts5Config*, Fts5Expr*, Fts5PoslistPopulator*, int, const char*, int
+);
+static void sqlite3Fts5ExprCheckPoslists(Fts5Expr*, i64);
+
+static int sqlite3Fts5ExprClonePhrase(Fts5Expr*, int, Fts5Expr**);
+
+static int sqlite3Fts5ExprPhraseCollist(Fts5Expr *, int, const u8 **, int *);
+
+/*******************************************
+** The fts5_expr.c API above this point is used by the other hand-written
+** C code in this module. The interfaces below this point are called by
+** the parser code in fts5parse.y.  */
+
+static void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...);
+
+static Fts5ExprNode *sqlite3Fts5ParseNode(
+  Fts5Parse *pParse,
+  int eType,
+  Fts5ExprNode *pLeft,
+  Fts5ExprNode *pRight,
+  Fts5ExprNearset *pNear
+);
+
+static Fts5ExprNode *sqlite3Fts5ParseImplicitAnd(
+  Fts5Parse *pParse,
+  Fts5ExprNode *pLeft,
+  Fts5ExprNode *pRight
+);
+
+static Fts5ExprPhrase *sqlite3Fts5ParseTerm(
+  Fts5Parse *pParse, 
+  Fts5ExprPhrase *pPhrase, 
+  Fts5Token *pToken,
+  int bPrefix
+);
+
+static Fts5ExprNearset *sqlite3Fts5ParseNearset(
+  Fts5Parse*, 
+  Fts5ExprNearset*,
+  Fts5ExprPhrase* 
+);
+
+static Fts5Colset *sqlite3Fts5ParseColset(
+  Fts5Parse*, 
+  Fts5Colset*, 
+  Fts5Token *
+);
+
+static void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase*);
+static void sqlite3Fts5ParseNearsetFree(Fts5ExprNearset*);
+static void sqlite3Fts5ParseNodeFree(Fts5ExprNode*);
+
+static void sqlite3Fts5ParseSetDistance(Fts5Parse*, Fts5ExprNearset*, Fts5Token*);
+static void sqlite3Fts5ParseSetColset(Fts5Parse*, Fts5ExprNearset*, Fts5Colset*);
+static void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p);
+static void sqlite3Fts5ParseNear(Fts5Parse *pParse, Fts5Token*);
+
+/*
+** End of interface to code in fts5_expr.c.
+**************************************************************************/
+
+
+
+/**************************************************************************
+** Interface to code in fts5_aux.c. 
+*/
+
+static int sqlite3Fts5AuxInit(fts5_api*);
+/*
+** End of interface to code in fts5_aux.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_tokenizer.c. 
+*/
+
+static int sqlite3Fts5TokenizerInit(fts5_api*);
+/*
+** End of interface to code in fts5_tokenizer.c.
+**************************************************************************/
+
+/**************************************************************************
+** Interface to code in fts5_vocab.c. 
+*/
+
+static int sqlite3Fts5VocabInit(Fts5Global*, sqlite3*);
+
+/*
+** End of interface to code in fts5_vocab.c.
+**************************************************************************/
+
+
+/**************************************************************************
+** Interface to automatically generated code in fts5_unicode2.c. 
+*/
+static int sqlite3Fts5UnicodeIsalnum(int c);
+static int sqlite3Fts5UnicodeIsdiacritic(int c);
+static int sqlite3Fts5UnicodeFold(int c, int bRemoveDiacritic);
+/*
+** End of interface to code in fts5_unicode2.c.
+**************************************************************************/
+
+#endif
+
+#define FTS5_OR                               1
+#define FTS5_AND                              2
+#define FTS5_NOT                              3
+#define FTS5_TERM                             4
+#define FTS5_COLON                            5
+#define FTS5_LP                               6
+#define FTS5_RP                               7
+#define FTS5_LCP                              8
+#define FTS5_RCP                              9
+#define FTS5_STRING                          10
+#define FTS5_COMMA                           11
+#define FTS5_PLUS                            12
+#define FTS5_STAR                            13
+
+/*
+** 2000-05-29
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Driver template for the LEMON parser generator.
+**
+** The "lemon" program processes an LALR(1) input grammar file, then uses
+** this template to construct a parser.  The "lemon" program inserts text
+** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the
+** interstitial "-" characters) contained in this template is changed into
+** the value of the %name directive from the grammar.  Otherwise, the content
+** of this template is copied straight through into the generate parser
+** source file.
+**
+** The following is the concatenation of all %include directives from the
+** input grammar file:
+*/
+/* #include <stdio.h> */
+/************ Begin %include sections from the grammar ************************/
+
+/* #include "fts5Int.h" */
+/* #include "fts5parse.h" */
+
+/*
+** Disable all error recovery processing in the parser push-down
+** automaton.
+*/
+#define fts5YYNOERRORRECOVERY 1
+
+/*
+** Make fts5yytestcase() the same as testcase()
+*/
+#define fts5yytestcase(X) testcase(X)
+
+/*
+** Indicate that sqlite3ParserFree() will never be called with a null
+** pointer.
+*/
+#define fts5YYPARSEFREENOTNULL 1
+
+/*
+** Alternative datatype for the argument to the malloc() routine passed
+** into sqlite3ParserAlloc().  The default is size_t.
+*/
+#define fts5YYMALLOCARGTYPE  u64
+
+/**************** End of %include directives **********************************/
+/* These constants specify the various numeric values for terminal symbols
+** in a format understandable to "makeheaders".  This section is blank unless
+** "lemon" is run with the "-m" command-line option.
+***************** Begin makeheaders token definitions *************************/
+/**************** End makeheaders token definitions ***************************/
+
+/* The next sections is a series of control #defines.
+** various aspects of the generated parser.
+**    fts5YYCODETYPE         is the data type used to store the integer codes
+**                       that represent terminal and non-terminal symbols.
+**                       "unsigned char" is used if there are fewer than
+**                       256 symbols.  Larger types otherwise.
+**    fts5YYNOCODE           is a number of type fts5YYCODETYPE that is not used for
+**                       any terminal or nonterminal symbol.
+**    fts5YYFALLBACK         If defined, this indicates that one or more tokens
+**                       (also known as: "terminal symbols") have fall-back
+**                       values which should be used if the original symbol
+**                       would not parse.  This permits keywords to sometimes
+**                       be used as identifiers, for example.
+**    fts5YYACTIONTYPE       is the data type used for "action codes" - numbers
+**                       that indicate what to do in response to the next
+**                       token.
+**    sqlite3Fts5ParserFTS5TOKENTYPE     is the data type used for minor type for terminal
+**                       symbols.  Background: A "minor type" is a semantic
+**                       value associated with a terminal or non-terminal
+**                       symbols.  For example, for an "ID" terminal symbol,
+**                       the minor type might be the name of the identifier.
+**                       Each non-terminal can have a different minor type.
+**                       Terminal symbols all have the same minor type, though.
+**                       This macros defines the minor type for terminal 
+**                       symbols.
+**    fts5YYMINORTYPE        is the data type used for all minor types.
+**                       This is typically a union of many types, one of
+**                       which is sqlite3Fts5ParserFTS5TOKENTYPE.  The entry in the union
+**                       for terminal symbols is called "fts5yy0".
+**    fts5YYSTACKDEPTH       is the maximum depth of the parser's stack.  If
+**                       zero the stack is dynamically sized using realloc()
+**    sqlite3Fts5ParserARG_SDECL     A static variable declaration for the %extra_argument
+**    sqlite3Fts5ParserARG_PDECL     A parameter declaration for the %extra_argument
+**    sqlite3Fts5ParserARG_STORE     Code to store %extra_argument into fts5yypParser
+**    sqlite3Fts5ParserARG_FETCH     Code to extract %extra_argument from fts5yypParser
+**    fts5YYERRORSYMBOL      is the code number of the error symbol.  If not
+**                       defined, then do no error processing.
+**    fts5YYNSTATE           the combined number of states.
+**    fts5YYNRULE            the number of rules in the grammar
+**    fts5YY_MAX_SHIFT       Maximum value for shift actions
+**    fts5YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
+**    fts5YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
+**    fts5YY_MIN_REDUCE      Maximum value for reduce actions
+**    fts5YY_ERROR_ACTION    The fts5yy_action[] code for syntax error
+**    fts5YY_ACCEPT_ACTION   The fts5yy_action[] code for accept
+**    fts5YY_NO_ACTION       The fts5yy_action[] code for no-op
+*/
+#ifndef INTERFACE
+# define INTERFACE 1
+#endif
+/************* Begin control #defines *****************************************/
+#define fts5YYCODETYPE unsigned char
+#define fts5YYNOCODE 27
+#define fts5YYACTIONTYPE unsigned char
+#define sqlite3Fts5ParserFTS5TOKENTYPE Fts5Token
+typedef union {
+  int fts5yyinit;
+  sqlite3Fts5ParserFTS5TOKENTYPE fts5yy0;
+  Fts5Colset* fts5yy3;
+  Fts5ExprPhrase* fts5yy11;
+  Fts5ExprNode* fts5yy18;
+  int fts5yy20;
+  Fts5ExprNearset* fts5yy26;
+} fts5YYMINORTYPE;
+#ifndef fts5YYSTACKDEPTH
+#define fts5YYSTACKDEPTH 100
+#endif
+#define sqlite3Fts5ParserARG_SDECL Fts5Parse *pParse;
+#define sqlite3Fts5ParserARG_PDECL ,Fts5Parse *pParse
+#define sqlite3Fts5ParserARG_FETCH Fts5Parse *pParse = fts5yypParser->pParse
+#define sqlite3Fts5ParserARG_STORE fts5yypParser->pParse = pParse
+#define fts5YYNSTATE             26
+#define fts5YYNRULE              24
+#define fts5YY_MAX_SHIFT         25
+#define fts5YY_MIN_SHIFTREDUCE   40
+#define fts5YY_MAX_SHIFTREDUCE   63
+#define fts5YY_MIN_REDUCE        64
+#define fts5YY_MAX_REDUCE        87
+#define fts5YY_ERROR_ACTION      88
+#define fts5YY_ACCEPT_ACTION     89
+#define fts5YY_NO_ACTION         90
+/************* End control #defines *******************************************/
+
+/* Define the fts5yytestcase() macro to be a no-op if is not already defined
+** otherwise.
+**
+** Applications can choose to define fts5yytestcase() in the %include section
+** to a macro that can assist in verifying code coverage.  For production
+** code the fts5yytestcase() macro should be turned off.  But it is useful
+** for testing.
+*/
+#ifndef fts5yytestcase
+# define fts5yytestcase(X)
+#endif
+
+
+/* Next are the tables used to determine what action to take based on the
+** current state and lookahead token.  These tables are used to implement
+** functions that take a state number and lookahead value and return an
+** action integer.  
+**
+** Suppose the action integer is N.  Then the action is determined as
+** follows
+**
+**   0 <= N <= fts5YY_MAX_SHIFT             Shift N.  That is, push the lookahead
+**                                      token onto the stack and goto state N.
+**
+**   N between fts5YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then
+**     and fts5YY_MAX_SHIFTREDUCE           reduce by rule N-fts5YY_MIN_SHIFTREDUCE.
+**
+**   N between fts5YY_MIN_REDUCE            Reduce by rule N-fts5YY_MIN_REDUCE
+**     and fts5YY_MAX_REDUCE
+
+**   N == fts5YY_ERROR_ACTION               A syntax error has occurred.
+**
+**   N == fts5YY_ACCEPT_ACTION              The parser accepts its input.
+**
+**   N == fts5YY_NO_ACTION                  No such action.  Denotes unused
+**                                      slots in the fts5yy_action[] table.
+**
+** The action table is constructed as a single large table named fts5yy_action[].
+** Given state S and lookahead X, the action is computed as
+**
+**      fts5yy_action[ fts5yy_shift_ofst[S] + X ]
+**
+** If the index value fts5yy_shift_ofst[S]+X is out of range or if the value
+** fts5yy_lookahead[fts5yy_shift_ofst[S]+X] is not equal to X or if fts5yy_shift_ofst[S]
+** is equal to fts5YY_SHIFT_USE_DFLT, it means that the action is not in the table
+** and that fts5yy_default[S] should be used instead.  
+**
+** The formula above is for computing the action when the lookahead is
+** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
+** a reduce action) then the fts5yy_reduce_ofst[] array is used in place of
+** the fts5yy_shift_ofst[] array and fts5YY_REDUCE_USE_DFLT is used in place of
+** fts5YY_SHIFT_USE_DFLT.
+**
+** The following are the tables generated in this section:
+**
+**  fts5yy_action[]        A single table containing all actions.
+**  fts5yy_lookahead[]     A table containing the lookahead for each entry in
+**                     fts5yy_action.  Used to detect hash collisions.
+**  fts5yy_shift_ofst[]    For each state, the offset into fts5yy_action for
+**                     shifting terminals.
+**  fts5yy_reduce_ofst[]   For each state, the offset into fts5yy_action for
+**                     shifting non-terminals after a reduce.
+**  fts5yy_default[]       Default action for each state.
+**
+*********** Begin parsing tables **********************************************/
+#define fts5YY_ACTTAB_COUNT (78)
+static const fts5YYACTIONTYPE fts5yy_action[] = {
+ /*     0 */    89,   15,   46,    5,   48,   24,   12,   19,   23,   14,
+ /*    10 */    46,    5,   48,   24,   20,   21,   23,   43,   46,    5,
+ /*    20 */    48,   24,    6,   18,   23,   17,   46,    5,   48,   24,
+ /*    30 */    75,    7,   23,   25,   46,    5,   48,   24,   62,   47,
+ /*    40 */    23,   48,   24,    7,   11,   23,    9,    3,    4,    2,
+ /*    50 */    62,   50,   52,   44,   64,    3,    4,    2,   49,    4,
+ /*    60 */     2,    1,   23,   11,   16,    9,   12,    2,   10,   61,
+ /*    70 */    53,   59,   62,   60,   22,   13,   55,    8,
+};
+static const fts5YYCODETYPE fts5yy_lookahead[] = {
+ /*     0 */    15,   16,   17,   18,   19,   20,   10,   11,   23,   16,
+ /*    10 */    17,   18,   19,   20,   23,   24,   23,   16,   17,   18,
+ /*    20 */    19,   20,   22,   23,   23,   16,   17,   18,   19,   20,
+ /*    30 */     5,    6,   23,   16,   17,   18,   19,   20,   13,   17,
+ /*    40 */    23,   19,   20,    6,    8,   23,   10,    1,    2,    3,
+ /*    50 */    13,    9,   10,    7,    0,    1,    2,    3,   19,    2,
+ /*    60 */     3,    6,   23,    8,   21,   10,   10,    3,   10,   25,
+ /*    70 */    10,   10,   13,   25,   12,   10,    7,    5,
+};
+#define fts5YY_SHIFT_USE_DFLT (-5)
+#define fts5YY_SHIFT_COUNT (25)
+#define fts5YY_SHIFT_MIN   (-4)
+#define fts5YY_SHIFT_MAX   (72)
+static const signed char fts5yy_shift_ofst[] = {
+ /*     0 */    55,   55,   55,   55,   55,   36,   -4,   56,   58,   25,
+ /*    10 */    37,   60,   59,   59,   46,   54,   42,   57,   62,   61,
+ /*    20 */    62,   69,   65,   62,   72,   64,
+};
+#define fts5YY_REDUCE_USE_DFLT (-16)
+#define fts5YY_REDUCE_COUNT (13)
+#define fts5YY_REDUCE_MIN   (-15)
+#define fts5YY_REDUCE_MAX   (48)
+static const signed char fts5yy_reduce_ofst[] = {
+ /*     0 */   -15,   -7,    1,    9,   17,   22,   -9,    0,   39,   44,
+ /*    10 */    44,   43,   44,   48,
+};
+static const fts5YYACTIONTYPE fts5yy_default[] = {
+ /*     0 */    88,   88,   88,   88,   88,   69,   82,   88,   88,   87,
+ /*    10 */    87,   88,   87,   87,   88,   88,   88,   66,   80,   88,
+ /*    20 */    81,   88,   88,   78,   88,   65,
+};
+/********** End of lemon-generated parsing tables *****************************/
+
+/* The next table maps tokens (terminal symbols) into fallback tokens.  
+** If a construct like the following:
+** 
+**      %fallback ID X Y Z.
+**
+** appears in the grammar, then ID becomes a fallback token for X, Y,
+** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
+** but it does not parse, the type of the token is changed to ID and
+** the parse is retried before an error is thrown.
+**
+** This feature can be used, for example, to cause some keywords in a language
+** to revert to identifiers if they keyword does not apply in the context where
+** it appears.
+*/
+#ifdef fts5YYFALLBACK
+static const fts5YYCODETYPE fts5yyFallback[] = {
+};
+#endif /* fts5YYFALLBACK */
+
+/* The following structure represents a single element of the
+** parser's stack.  Information stored includes:
+**
+**   +  The state number for the parser at this level of the stack.
+**
+**   +  The value of the token stored at this level of the stack.
+**      (In other words, the "major" token.)
+**
+**   +  The semantic value stored at this level of the stack.  This is
+**      the information used by the action routines in the grammar.
+**      It is sometimes called the "minor" token.
+**
+** After the "shift" half of a SHIFTREDUCE action, the stateno field
+** actually contains the reduce action for the second half of the
+** SHIFTREDUCE.
+*/
+struct fts5yyStackEntry {
+  fts5YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */
+  fts5YYCODETYPE major;      /* The major token value.  This is the code
+                         ** number for the token at this stack level */
+  fts5YYMINORTYPE minor;     /* The user-supplied minor token value.  This
+                         ** is the value of the token  */
+};
+typedef struct fts5yyStackEntry fts5yyStackEntry;
+
+/* The state of the parser is completely contained in an instance of
+** the following structure */
+struct fts5yyParser {
+  fts5yyStackEntry *fts5yytos;          /* Pointer to top element of the stack */
+#ifdef fts5YYTRACKMAXSTACKDEPTH
+  int fts5yyhwm;                    /* High-water mark of the stack */
+#endif
+#ifndef fts5YYNOERRORRECOVERY
+  int fts5yyerrcnt;                 /* Shifts left before out of the error */
+#endif
+  sqlite3Fts5ParserARG_SDECL                /* A place to hold %extra_argument */
+#if fts5YYSTACKDEPTH<=0
+  int fts5yystksz;                  /* Current side of the stack */
+  fts5yyStackEntry *fts5yystack;        /* The parser's stack */
+  fts5yyStackEntry fts5yystk0;          /* First stack entry */
+#else
+  fts5yyStackEntry fts5yystack[fts5YYSTACKDEPTH];  /* The parser's stack */
+#endif
+};
+typedef struct fts5yyParser fts5yyParser;
+
+#ifndef NDEBUG
+/* #include <stdio.h> */
+static FILE *fts5yyTraceFILE = 0;
+static char *fts5yyTracePrompt = 0;
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* 
+** Turn parser tracing on by giving a stream to which to write the trace
+** and a prompt to preface each trace message.  Tracing is turned off
+** by making either argument NULL 
+**
+** Inputs:
+** <ul>
+** <li> A FILE* to which trace output should be written.
+**      If NULL, then tracing is turned off.
+** <li> A prefix string written at the beginning of every
+**      line of trace output.  If NULL, then tracing is
+**      turned off.
+** </ul>
+**
+** Outputs:
+** None.
+*/
+static void sqlite3Fts5ParserTrace(FILE *TraceFILE, char *zTracePrompt){
+  fts5yyTraceFILE = TraceFILE;
+  fts5yyTracePrompt = zTracePrompt;
+  if( fts5yyTraceFILE==0 ) fts5yyTracePrompt = 0;
+  else if( fts5yyTracePrompt==0 ) fts5yyTraceFILE = 0;
+}
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing shifts, the names of all terminals and nonterminals
+** are required.  The following table supplies these names */
+static const char *const fts5yyTokenName[] = { 
+  "$",             "OR",            "AND",           "NOT",         
+  "TERM",          "COLON",         "LP",            "RP",          
+  "LCP",           "RCP",           "STRING",        "COMMA",       
+  "PLUS",          "STAR",          "error",         "input",       
+  "expr",          "cnearset",      "exprlist",      "nearset",     
+  "colset",        "colsetlist",    "nearphrases",   "phrase",      
+  "neardist_opt",  "star_opt",    
+};
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing reduce actions, the names of all rules are required.
+*/
+static const char *const fts5yyRuleName[] = {
+ /*   0 */ "input ::= expr",
+ /*   1 */ "expr ::= expr AND expr",
+ /*   2 */ "expr ::= expr OR expr",
+ /*   3 */ "expr ::= expr NOT expr",
+ /*   4 */ "expr ::= LP expr RP",
+ /*   5 */ "expr ::= exprlist",
+ /*   6 */ "exprlist ::= cnearset",
+ /*   7 */ "exprlist ::= exprlist cnearset",
+ /*   8 */ "cnearset ::= nearset",
+ /*   9 */ "cnearset ::= colset COLON nearset",
+ /*  10 */ "colset ::= LCP colsetlist RCP",
+ /*  11 */ "colset ::= STRING",
+ /*  12 */ "colsetlist ::= colsetlist STRING",
+ /*  13 */ "colsetlist ::= STRING",
+ /*  14 */ "nearset ::= phrase",
+ /*  15 */ "nearset ::= STRING LP nearphrases neardist_opt RP",
+ /*  16 */ "nearphrases ::= phrase",
+ /*  17 */ "nearphrases ::= nearphrases phrase",
+ /*  18 */ "neardist_opt ::=",
+ /*  19 */ "neardist_opt ::= COMMA STRING",
+ /*  20 */ "phrase ::= phrase PLUS STRING star_opt",
+ /*  21 */ "phrase ::= STRING star_opt",
+ /*  22 */ "star_opt ::= STAR",
+ /*  23 */ "star_opt ::=",
+};
+#endif /* NDEBUG */
+
+
+#if fts5YYSTACKDEPTH<=0
+/*
+** Try to increase the size of the parser stack.  Return the number
+** of errors.  Return 0 on success.
+*/
+static int fts5yyGrowStack(fts5yyParser *p){
+  int newSize;
+  int idx;
+  fts5yyStackEntry *pNew;
+
+  newSize = p->fts5yystksz*2 + 100;
+  idx = p->fts5yytos ? (int)(p->fts5yytos - p->fts5yystack) : 0;
+  if( p->fts5yystack==&p->fts5yystk0 ){
+    pNew = malloc(newSize*sizeof(pNew[0]));
+    if( pNew ) pNew[0] = p->fts5yystk0;
+  }else{
+    pNew = realloc(p->fts5yystack, newSize*sizeof(pNew[0]));
+  }
+  if( pNew ){
+    p->fts5yystack = pNew;
+    p->fts5yytos = &p->fts5yystack[idx];
+#ifndef NDEBUG
+    if( fts5yyTraceFILE ){
+      fprintf(fts5yyTraceFILE,"%sStack grows from %d to %d entries.\n",
+              fts5yyTracePrompt, p->fts5yystksz, newSize);
+    }
+#endif
+    p->fts5yystksz = newSize;
+  }
+  return pNew==0; 
+}
+#endif
+
+/* Datatype of the argument to the memory allocated passed as the
+** second argument to sqlite3Fts5ParserAlloc() below.  This can be changed by
+** putting an appropriate #define in the %include section of the input
+** grammar.
+*/
+#ifndef fts5YYMALLOCARGTYPE
+# define fts5YYMALLOCARGTYPE size_t
+#endif
+
+/* 
+** This function allocates a new parser.
+** The only argument is a pointer to a function which works like
+** malloc.
+**
+** Inputs:
+** A pointer to the function used to allocate memory.
+**
+** Outputs:
+** A pointer to a parser.  This pointer is used in subsequent calls
+** to sqlite3Fts5Parser and sqlite3Fts5ParserFree.
+*/
+static void *sqlite3Fts5ParserAlloc(void *(*mallocProc)(fts5YYMALLOCARGTYPE)){
+  fts5yyParser *pParser;
+  pParser = (fts5yyParser*)(*mallocProc)( (fts5YYMALLOCARGTYPE)sizeof(fts5yyParser) );
+  if( pParser ){
+#ifdef fts5YYTRACKMAXSTACKDEPTH
+    pParser->fts5yyhwm = 0;
+#endif
+#if fts5YYSTACKDEPTH<=0
+    pParser->fts5yytos = NULL;
+    pParser->fts5yystack = NULL;
+    pParser->fts5yystksz = 0;
+    if( fts5yyGrowStack(pParser) ){
+      pParser->fts5yystack = &pParser->fts5yystk0;
+      pParser->fts5yystksz = 1;
+    }
+#endif
+#ifndef fts5YYNOERRORRECOVERY
+    pParser->fts5yyerrcnt = -1;
+#endif
+    pParser->fts5yytos = pParser->fts5yystack;
+    pParser->fts5yystack[0].stateno = 0;
+    pParser->fts5yystack[0].major = 0;
+  }
+  return pParser;
+}
+
+/* The following function deletes the "minor type" or semantic value
+** associated with a symbol.  The symbol can be either a terminal
+** or nonterminal. "fts5yymajor" is the symbol code, and "fts5yypminor" is
+** a pointer to the value to be deleted.  The code used to do the 
+** deletions is derived from the %destructor and/or %token_destructor
+** directives of the input grammar.
+*/
+static void fts5yy_destructor(
+  fts5yyParser *fts5yypParser,    /* The parser */
+  fts5YYCODETYPE fts5yymajor,     /* Type code for object to destroy */
+  fts5YYMINORTYPE *fts5yypminor   /* The object to be destroyed */
+){
+  sqlite3Fts5ParserARG_FETCH;
+  switch( fts5yymajor ){
+    /* Here is inserted the actions which take place when a
+    ** terminal or non-terminal is destroyed.  This can happen
+    ** when the symbol is popped from the stack during a
+    ** reduce or during error processing or when a parser is 
+    ** being destroyed before it is finished parsing.
+    **
+    ** Note: during a reduce, the only symbols destroyed are those
+    ** which appear on the RHS of the rule, but which are *not* used
+    ** inside the C code.
+    */
+/********* Begin destructor definitions ***************************************/
+    case 15: /* input */
+{
+ (void)pParse; 
+}
+      break;
+    case 16: /* expr */
+    case 17: /* cnearset */
+    case 18: /* exprlist */
+{
+ sqlite3Fts5ParseNodeFree((fts5yypminor->fts5yy18)); 
+}
+      break;
+    case 19: /* nearset */
+    case 22: /* nearphrases */
+{
+ sqlite3Fts5ParseNearsetFree((fts5yypminor->fts5yy26)); 
+}
+      break;
+    case 20: /* colset */
+    case 21: /* colsetlist */
+{
+ sqlite3_free((fts5yypminor->fts5yy3)); 
+}
+      break;
+    case 23: /* phrase */
+{
+ sqlite3Fts5ParsePhraseFree((fts5yypminor->fts5yy11)); 
+}
+      break;
+/********* End destructor definitions *****************************************/
+    default:  break;   /* If no destructor action specified: do nothing */
+  }
+}
+
+/*
+** Pop the parser's stack once.
+**
+** If there is a destructor routine associated with the token which
+** is popped from the stack, then call it.
+*/
+static void fts5yy_pop_parser_stack(fts5yyParser *pParser){
+  fts5yyStackEntry *fts5yytos;
+  assert( pParser->fts5yytos!=0 );
+  assert( pParser->fts5yytos > pParser->fts5yystack );
+  fts5yytos = pParser->fts5yytos--;
+#ifndef NDEBUG
+  if( fts5yyTraceFILE ){
+    fprintf(fts5yyTraceFILE,"%sPopping %s\n",
+      fts5yyTracePrompt,
+      fts5yyTokenName[fts5yytos->major]);
+  }
+#endif
+  fts5yy_destructor(pParser, fts5yytos->major, &fts5yytos->minor);
+}
+
+/* 
+** Deallocate and destroy a parser.  Destructors are called for
+** all stack elements before shutting the parser down.
+**
+** If the fts5YYPARSEFREENEVERNULL macro exists (for example because it
+** is defined in a %include section of the input grammar) then it is
+** assumed that the input pointer is never NULL.
+*/
+static void sqlite3Fts5ParserFree(
+  void *p,                    /* The parser to be deleted */
+  void (*freeProc)(void*)     /* Function used to reclaim memory */
+){
+  fts5yyParser *pParser = (fts5yyParser*)p;
+#ifndef fts5YYPARSEFREENEVERNULL
+  if( pParser==0 ) return;
+#endif
+  while( pParser->fts5yytos>pParser->fts5yystack ) fts5yy_pop_parser_stack(pParser);
+#if fts5YYSTACKDEPTH<=0
+  if( pParser->fts5yystack!=&pParser->fts5yystk0 ) free(pParser->fts5yystack);
+#endif
+  (*freeProc)((void*)pParser);
+}
+
+/*
+** Return the peak depth of the stack for a parser.
+*/
+#ifdef fts5YYTRACKMAXSTACKDEPTH
+static int sqlite3Fts5ParserStackPeak(void *p){
+  fts5yyParser *pParser = (fts5yyParser*)p;
+  return pParser->fts5yyhwm;
+}
+#endif
+
+/*
+** Find the appropriate action for a parser given the terminal
+** look-ahead token iLookAhead.
+*/
+static unsigned int fts5yy_find_shift_action(
+  fts5yyParser *pParser,        /* The parser */
+  fts5YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+  int stateno = pParser->fts5yytos->stateno;
+ 
+  if( stateno>=fts5YY_MIN_REDUCE ) return stateno;
+  assert( stateno <= fts5YY_SHIFT_COUNT );
+  do{
+    i = fts5yy_shift_ofst[stateno];
+    if( i==fts5YY_SHIFT_USE_DFLT ) return fts5yy_default[stateno];
+    assert( iLookAhead!=fts5YYNOCODE );
+    i += iLookAhead;
+    if( i<0 || i>=fts5YY_ACTTAB_COUNT || fts5yy_lookahead[i]!=iLookAhead ){
+      if( iLookAhead>0 ){
+#ifdef fts5YYFALLBACK
+        fts5YYCODETYPE iFallback;            /* Fallback token */
+        if( iLookAhead<sizeof(fts5yyFallback)/sizeof(fts5yyFallback[0])
+               && (iFallback = fts5yyFallback[iLookAhead])!=0 ){
+#ifndef NDEBUG
+          if( fts5yyTraceFILE ){
+            fprintf(fts5yyTraceFILE, "%sFALLBACK %s => %s\n",
+               fts5yyTracePrompt, fts5yyTokenName[iLookAhead], fts5yyTokenName[iFallback]);
+          }
+#endif
+          assert( fts5yyFallback[iFallback]==0 ); /* Fallback loop must terminate */
+          iLookAhead = iFallback;
+          continue;
+        }
+#endif
+#ifdef fts5YYWILDCARD
+        {
+          int j = i - iLookAhead + fts5YYWILDCARD;
+          if( 
+#if fts5YY_SHIFT_MIN+fts5YYWILDCARD<0
+            j>=0 &&
+#endif
+#if fts5YY_SHIFT_MAX+fts5YYWILDCARD>=fts5YY_ACTTAB_COUNT
+            j<fts5YY_ACTTAB_COUNT &&
+#endif
+            fts5yy_lookahead[j]==fts5YYWILDCARD
+          ){
+#ifndef NDEBUG
+            if( fts5yyTraceFILE ){
+              fprintf(fts5yyTraceFILE, "%sWILDCARD %s => %s\n",
+                 fts5yyTracePrompt, fts5yyTokenName[iLookAhead],
+                 fts5yyTokenName[fts5YYWILDCARD]);
+            }
+#endif /* NDEBUG */
+            return fts5yy_action[j];
+          }
+        }
+#endif /* fts5YYWILDCARD */
+      }
+      return fts5yy_default[stateno];
+    }else{
+      return fts5yy_action[i];
+    }
+  }while(1);
+}
+
+/*
+** Find the appropriate action for a parser given the non-terminal
+** look-ahead token iLookAhead.
+*/
+static int fts5yy_find_reduce_action(
+  int stateno,              /* Current state number */
+  fts5YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+#ifdef fts5YYERRORSYMBOL
+  if( stateno>fts5YY_REDUCE_COUNT ){
+    return fts5yy_default[stateno];
+  }
+#else
+  assert( stateno<=fts5YY_REDUCE_COUNT );
+#endif
+  i = fts5yy_reduce_ofst[stateno];
+  assert( i!=fts5YY_REDUCE_USE_DFLT );
+  assert( iLookAhead!=fts5YYNOCODE );
+  i += iLookAhead;
+#ifdef fts5YYERRORSYMBOL
+  if( i<0 || i>=fts5YY_ACTTAB_COUNT || fts5yy_lookahead[i]!=iLookAhead ){
+    return fts5yy_default[stateno];
+  }
+#else
+  assert( i>=0 && i<fts5YY_ACTTAB_COUNT );
+  assert( fts5yy_lookahead[i]==iLookAhead );
+#endif
+  return fts5yy_action[i];
+}
+
+/*
+** The following routine is called if the stack overflows.
+*/
+static void fts5yyStackOverflow(fts5yyParser *fts5yypParser){
+   sqlite3Fts5ParserARG_FETCH;
+   fts5yypParser->fts5yytos--;
+#ifndef NDEBUG
+   if( fts5yyTraceFILE ){
+     fprintf(fts5yyTraceFILE,"%sStack Overflow!\n",fts5yyTracePrompt);
+   }
+#endif
+   while( fts5yypParser->fts5yytos>fts5yypParser->fts5yystack ) fts5yy_pop_parser_stack(fts5yypParser);
+   /* Here code is inserted which will execute if the parser
+   ** stack every overflows */
+/******** Begin %stack_overflow code ******************************************/
+
+  sqlite3Fts5ParseError(pParse, "fts5: parser stack overflow");
+/******** End %stack_overflow code ********************************************/
+   sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
+}
+
+/*
+** Print tracing information for a SHIFT action
+*/
+#ifndef NDEBUG
+static void fts5yyTraceShift(fts5yyParser *fts5yypParser, int fts5yyNewState){
+  if( fts5yyTraceFILE ){
+    if( fts5yyNewState<fts5YYNSTATE ){
+      fprintf(fts5yyTraceFILE,"%sShift '%s', go to state %d\n",
+         fts5yyTracePrompt,fts5yyTokenName[fts5yypParser->fts5yytos->major],
+         fts5yyNewState);
+    }else{
+      fprintf(fts5yyTraceFILE,"%sShift '%s'\n",
+         fts5yyTracePrompt,fts5yyTokenName[fts5yypParser->fts5yytos->major]);
+    }
+  }
+}
+#else
+# define fts5yyTraceShift(X,Y)
+#endif
+
+/*
+** Perform a shift action.
+*/
+static void fts5yy_shift(
+  fts5yyParser *fts5yypParser,          /* The parser to be shifted */
+  int fts5yyNewState,               /* The new state to shift in */
+  int fts5yyMajor,                  /* The major token to shift in */
+  sqlite3Fts5ParserFTS5TOKENTYPE fts5yyMinor        /* The minor token to shift in */
+){
+  fts5yyStackEntry *fts5yytos;
+  fts5yypParser->fts5yytos++;
+#ifdef fts5YYTRACKMAXSTACKDEPTH
+  if( (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack)>fts5yypParser->fts5yyhwm ){
+    fts5yypParser->fts5yyhwm++;
+    assert( fts5yypParser->fts5yyhwm == (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack) );
+  }
+#endif
+#if fts5YYSTACKDEPTH>0 
+  if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5YYSTACKDEPTH] ){
+    fts5yyStackOverflow(fts5yypParser);
+    return;
+  }
+#else
+  if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5yypParser->fts5yystksz] ){
+    if( fts5yyGrowStack(fts5yypParser) ){
+      fts5yyStackOverflow(fts5yypParser);
+      return;
+    }
+  }
+#endif
+  if( fts5yyNewState > fts5YY_MAX_SHIFT ){
+    fts5yyNewState += fts5YY_MIN_REDUCE - fts5YY_MIN_SHIFTREDUCE;
+  }
+  fts5yytos = fts5yypParser->fts5yytos;
+  fts5yytos->stateno = (fts5YYACTIONTYPE)fts5yyNewState;
+  fts5yytos->major = (fts5YYCODETYPE)fts5yyMajor;
+  fts5yytos->minor.fts5yy0 = fts5yyMinor;
+  fts5yyTraceShift(fts5yypParser, fts5yyNewState);
+}
+
+/* The following table contains information about every rule that
+** is used during the reduce.
+*/
+static const struct {
+  fts5YYCODETYPE lhs;         /* Symbol on the left-hand side of the rule */
+  unsigned char nrhs;     /* Number of right-hand side symbols in the rule */
+} fts5yyRuleInfo[] = {
+  { 15, 1 },
+  { 16, 3 },
+  { 16, 3 },
+  { 16, 3 },
+  { 16, 3 },
+  { 16, 1 },
+  { 18, 1 },
+  { 18, 2 },
+  { 17, 1 },
+  { 17, 3 },
+  { 20, 3 },
+  { 20, 1 },
+  { 21, 2 },
+  { 21, 1 },
+  { 19, 1 },
+  { 19, 5 },
+  { 22, 1 },
+  { 22, 2 },
+  { 24, 0 },
+  { 24, 2 },
+  { 23, 4 },
+  { 23, 2 },
+  { 25, 1 },
+  { 25, 0 },
+};
+
+static void fts5yy_accept(fts5yyParser*);  /* Forward Declaration */
+
+/*
+** Perform a reduce action and the shift that must immediately
+** follow the reduce.
+*/
+static void fts5yy_reduce(
+  fts5yyParser *fts5yypParser,         /* The parser */
+  unsigned int fts5yyruleno        /* Number of the rule by which to reduce */
+){
+  int fts5yygoto;                     /* The next state */
+  int fts5yyact;                      /* The next action */
+  fts5yyStackEntry *fts5yymsp;            /* The top of the parser's stack */
+  int fts5yysize;                     /* Amount to pop the stack */
+  sqlite3Fts5ParserARG_FETCH;
+  fts5yymsp = fts5yypParser->fts5yytos;
+#ifndef NDEBUG
+  if( fts5yyTraceFILE && fts5yyruleno<(int)(sizeof(fts5yyRuleName)/sizeof(fts5yyRuleName[0])) ){
+    fts5yysize = fts5yyRuleInfo[fts5yyruleno].nrhs;
+    fprintf(fts5yyTraceFILE, "%sReduce [%s], go to state %d.\n", fts5yyTracePrompt,
+      fts5yyRuleName[fts5yyruleno], fts5yymsp[-fts5yysize].stateno);
+  }
+#endif /* NDEBUG */
+
+  /* Check that the stack is large enough to grow by a single entry
+  ** if the RHS of the rule is empty.  This ensures that there is room
+  ** enough on the stack to push the LHS value */
+  if( fts5yyRuleInfo[fts5yyruleno].nrhs==0 ){
+#ifdef fts5YYTRACKMAXSTACKDEPTH
+    if( (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack)>fts5yypParser->fts5yyhwm ){
+      fts5yypParser->fts5yyhwm++;
+      assert( fts5yypParser->fts5yyhwm == (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack));
+    }
+#endif
+#if fts5YYSTACKDEPTH>0 
+    if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5YYSTACKDEPTH-1] ){
+      fts5yyStackOverflow(fts5yypParser);
+      return;
+    }
+#else
+    if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5yypParser->fts5yystksz-1] ){
+      if( fts5yyGrowStack(fts5yypParser) ){
+        fts5yyStackOverflow(fts5yypParser);
+        return;
+      }
+      fts5yymsp = fts5yypParser->fts5yytos;
+    }
+#endif
+  }
+
+  switch( fts5yyruleno ){
+  /* Beginning here are the reduction cases.  A typical example
+  ** follows:
+  **   case 0:
+  **  #line <lineno> <grammarfile>
+  **     { ... }           // User supplied code
+  **  #line <lineno> <thisfile>
+  **     break;
+  */
+/********** Begin reduce actions **********************************************/
+        fts5YYMINORTYPE fts5yylhsminor;
+      case 0: /* input ::= expr */
+{ sqlite3Fts5ParseFinished(pParse, fts5yymsp[0].minor.fts5yy18); }
+        break;
+      case 1: /* expr ::= expr AND expr */
+{
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseNode(pParse, FTS5_AND, fts5yymsp[-2].minor.fts5yy18, fts5yymsp[0].minor.fts5yy18, 0);
+}
+  fts5yymsp[-2].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 2: /* expr ::= expr OR expr */
+{
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseNode(pParse, FTS5_OR, fts5yymsp[-2].minor.fts5yy18, fts5yymsp[0].minor.fts5yy18, 0);
+}
+  fts5yymsp[-2].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 3: /* expr ::= expr NOT expr */
+{
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseNode(pParse, FTS5_NOT, fts5yymsp[-2].minor.fts5yy18, fts5yymsp[0].minor.fts5yy18, 0);
+}
+  fts5yymsp[-2].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 4: /* expr ::= LP expr RP */
+{fts5yymsp[-2].minor.fts5yy18 = fts5yymsp[-1].minor.fts5yy18;}
+        break;
+      case 5: /* expr ::= exprlist */
+      case 6: /* exprlist ::= cnearset */ fts5yytestcase(fts5yyruleno==6);
+{fts5yylhsminor.fts5yy18 = fts5yymsp[0].minor.fts5yy18;}
+  fts5yymsp[0].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 7: /* exprlist ::= exprlist cnearset */
+{
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseImplicitAnd(pParse, fts5yymsp[-1].minor.fts5yy18, fts5yymsp[0].minor.fts5yy18);
+}
+  fts5yymsp[-1].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 8: /* cnearset ::= nearset */
+{ 
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseNode(pParse, FTS5_STRING, 0, 0, fts5yymsp[0].minor.fts5yy26); 
+}
+  fts5yymsp[0].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 9: /* cnearset ::= colset COLON nearset */
+{ 
+  sqlite3Fts5ParseSetColset(pParse, fts5yymsp[0].minor.fts5yy26, fts5yymsp[-2].minor.fts5yy3);
+  fts5yylhsminor.fts5yy18 = sqlite3Fts5ParseNode(pParse, FTS5_STRING, 0, 0, fts5yymsp[0].minor.fts5yy26); 
+}
+  fts5yymsp[-2].minor.fts5yy18 = fts5yylhsminor.fts5yy18;
+        break;
+      case 10: /* colset ::= LCP colsetlist RCP */
+{ fts5yymsp[-2].minor.fts5yy3 = fts5yymsp[-1].minor.fts5yy3; }
+        break;
+      case 11: /* colset ::= STRING */
+{
+  fts5yylhsminor.fts5yy3 = sqlite3Fts5ParseColset(pParse, 0, &fts5yymsp[0].minor.fts5yy0);
+}
+  fts5yymsp[0].minor.fts5yy3 = fts5yylhsminor.fts5yy3;
+        break;
+      case 12: /* colsetlist ::= colsetlist STRING */
+{ 
+  fts5yylhsminor.fts5yy3 = sqlite3Fts5ParseColset(pParse, fts5yymsp[-1].minor.fts5yy3, &fts5yymsp[0].minor.fts5yy0); }
+  fts5yymsp[-1].minor.fts5yy3 = fts5yylhsminor.fts5yy3;
+        break;
+      case 13: /* colsetlist ::= STRING */
+{ 
+  fts5yylhsminor.fts5yy3 = sqlite3Fts5ParseColset(pParse, 0, &fts5yymsp[0].minor.fts5yy0); 
+}
+  fts5yymsp[0].minor.fts5yy3 = fts5yylhsminor.fts5yy3;
+        break;
+      case 14: /* nearset ::= phrase */
+{ fts5yylhsminor.fts5yy26 = sqlite3Fts5ParseNearset(pParse, 0, fts5yymsp[0].minor.fts5yy11); }
+  fts5yymsp[0].minor.fts5yy26 = fts5yylhsminor.fts5yy26;
+        break;
+      case 15: /* nearset ::= STRING LP nearphrases neardist_opt RP */
+{
+  sqlite3Fts5ParseNear(pParse, &fts5yymsp[-4].minor.fts5yy0);
+  sqlite3Fts5ParseSetDistance(pParse, fts5yymsp[-2].minor.fts5yy26, &fts5yymsp[-1].minor.fts5yy0);
+  fts5yylhsminor.fts5yy26 = fts5yymsp[-2].minor.fts5yy26;
+}
+  fts5yymsp[-4].minor.fts5yy26 = fts5yylhsminor.fts5yy26;
+        break;
+      case 16: /* nearphrases ::= phrase */
+{ 
+  fts5yylhsminor.fts5yy26 = sqlite3Fts5ParseNearset(pParse, 0, fts5yymsp[0].minor.fts5yy11); 
+}
+  fts5yymsp[0].minor.fts5yy26 = fts5yylhsminor.fts5yy26;
+        break;
+      case 17: /* nearphrases ::= nearphrases phrase */
+{
+  fts5yylhsminor.fts5yy26 = sqlite3Fts5ParseNearset(pParse, fts5yymsp[-1].minor.fts5yy26, fts5yymsp[0].minor.fts5yy11);
+}
+  fts5yymsp[-1].minor.fts5yy26 = fts5yylhsminor.fts5yy26;
+        break;
+      case 18: /* neardist_opt ::= */
+{ fts5yymsp[1].minor.fts5yy0.p = 0; fts5yymsp[1].minor.fts5yy0.n = 0; }
+        break;
+      case 19: /* neardist_opt ::= COMMA STRING */
+{ fts5yymsp[-1].minor.fts5yy0 = fts5yymsp[0].minor.fts5yy0; }
+        break;
+      case 20: /* phrase ::= phrase PLUS STRING star_opt */
+{ 
+  fts5yylhsminor.fts5yy11 = sqlite3Fts5ParseTerm(pParse, fts5yymsp[-3].minor.fts5yy11, &fts5yymsp[-1].minor.fts5yy0, fts5yymsp[0].minor.fts5yy20);
+}
+  fts5yymsp[-3].minor.fts5yy11 = fts5yylhsminor.fts5yy11;
+        break;
+      case 21: /* phrase ::= STRING star_opt */
+{ 
+  fts5yylhsminor.fts5yy11 = sqlite3Fts5ParseTerm(pParse, 0, &fts5yymsp[-1].minor.fts5yy0, fts5yymsp[0].minor.fts5yy20);
+}
+  fts5yymsp[-1].minor.fts5yy11 = fts5yylhsminor.fts5yy11;
+        break;
+      case 22: /* star_opt ::= STAR */
+{ fts5yymsp[0].minor.fts5yy20 = 1; }
+        break;
+      case 23: /* star_opt ::= */
+{ fts5yymsp[1].minor.fts5yy20 = 0; }
+        break;
+      default:
+        break;
+/********** End reduce actions ************************************************/
+  };
+  assert( fts5yyruleno<sizeof(fts5yyRuleInfo)/sizeof(fts5yyRuleInfo[0]) );
+  fts5yygoto = fts5yyRuleInfo[fts5yyruleno].lhs;
+  fts5yysize = fts5yyRuleInfo[fts5yyruleno].nrhs;
+  fts5yyact = fts5yy_find_reduce_action(fts5yymsp[-fts5yysize].stateno,(fts5YYCODETYPE)fts5yygoto);
+  if( fts5yyact <= fts5YY_MAX_SHIFTREDUCE ){
+    if( fts5yyact>fts5YY_MAX_SHIFT ){
+      fts5yyact += fts5YY_MIN_REDUCE - fts5YY_MIN_SHIFTREDUCE;
+    }
+    fts5yymsp -= fts5yysize-1;
+    fts5yypParser->fts5yytos = fts5yymsp;
+    fts5yymsp->stateno = (fts5YYACTIONTYPE)fts5yyact;
+    fts5yymsp->major = (fts5YYCODETYPE)fts5yygoto;
+    fts5yyTraceShift(fts5yypParser, fts5yyact);
+  }else{
+    assert( fts5yyact == fts5YY_ACCEPT_ACTION );
+    fts5yypParser->fts5yytos -= fts5yysize;
+    fts5yy_accept(fts5yypParser);
+  }
+}
+
+/*
+** The following code executes when the parse fails
+*/
+#ifndef fts5YYNOERRORRECOVERY
+static void fts5yy_parse_failed(
+  fts5yyParser *fts5yypParser           /* The parser */
+){
+  sqlite3Fts5ParserARG_FETCH;
+#ifndef NDEBUG
+  if( fts5yyTraceFILE ){
+    fprintf(fts5yyTraceFILE,"%sFail!\n",fts5yyTracePrompt);
+  }
+#endif
+  while( fts5yypParser->fts5yytos>fts5yypParser->fts5yystack ) fts5yy_pop_parser_stack(fts5yypParser);
+  /* Here code is inserted which will be executed whenever the
+  ** parser fails */
+/************ Begin %parse_failure code ***************************************/
+/************ End %parse_failure code *****************************************/
+  sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+#endif /* fts5YYNOERRORRECOVERY */
+
+/*
+** The following code executes when a syntax error first occurs.
+*/
+static void fts5yy_syntax_error(
+  fts5yyParser *fts5yypParser,           /* The parser */
+  int fts5yymajor,                   /* The major type of the error token */
+  sqlite3Fts5ParserFTS5TOKENTYPE fts5yyminor         /* The minor type of the error token */
+){
+  sqlite3Fts5ParserARG_FETCH;
+#define FTS5TOKEN fts5yyminor
+/************ Begin %syntax_error code ****************************************/
+
+  UNUSED_PARAM(fts5yymajor); /* Silence a compiler warning */
+  sqlite3Fts5ParseError(
+    pParse, "fts5: syntax error near \"%.*s\"",FTS5TOKEN.n,FTS5TOKEN.p
+  );
+/************ End %syntax_error code ******************************************/
+  sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/*
+** The following is executed when the parser accepts
+*/
+static void fts5yy_accept(
+  fts5yyParser *fts5yypParser           /* The parser */
+){
+  sqlite3Fts5ParserARG_FETCH;
+#ifndef NDEBUG
+  if( fts5yyTraceFILE ){
+    fprintf(fts5yyTraceFILE,"%sAccept!\n",fts5yyTracePrompt);
+  }
+#endif
+#ifndef fts5YYNOERRORRECOVERY
+  fts5yypParser->fts5yyerrcnt = -1;
+#endif
+  assert( fts5yypParser->fts5yytos==fts5yypParser->fts5yystack );
+  /* Here code is inserted which will be executed whenever the
+  ** parser accepts */
+/*********** Begin %parse_accept code *****************************************/
+/*********** End %parse_accept code *******************************************/
+  sqlite3Fts5ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/* The main parser program.
+** The first argument is a pointer to a structure obtained from
+** "sqlite3Fts5ParserAlloc" which describes the current state of the parser.
+** The second argument is the major token number.  The third is
+** the minor token.  The fourth optional argument is whatever the
+** user wants (and specified in the grammar) and is available for
+** use by the action routines.
+**
+** Inputs:
+** <ul>
+** <li> A pointer to the parser (an opaque structure.)
+** <li> The major token number.
+** <li> The minor token number.
+** <li> An option argument of a grammar-specified type.
+** </ul>
+**
+** Outputs:
+** None.
+*/
+static void sqlite3Fts5Parser(
+  void *fts5yyp,                   /* The parser */
+  int fts5yymajor,                 /* The major token code number */
+  sqlite3Fts5ParserFTS5TOKENTYPE fts5yyminor       /* The value for the token */
+  sqlite3Fts5ParserARG_PDECL               /* Optional %extra_argument parameter */
+){
+  fts5YYMINORTYPE fts5yyminorunion;
+  unsigned int fts5yyact;   /* The parser action. */
+#if !defined(fts5YYERRORSYMBOL) && !defined(fts5YYNOERRORRECOVERY)
+  int fts5yyendofinput;     /* True if we are at the end of input */
+#endif
+#ifdef fts5YYERRORSYMBOL
+  int fts5yyerrorhit = 0;   /* True if fts5yymajor has invoked an error */
+#endif
+  fts5yyParser *fts5yypParser;  /* The parser */
+
+  fts5yypParser = (fts5yyParser*)fts5yyp;
+  assert( fts5yypParser->fts5yytos!=0 );
+#if !defined(fts5YYERRORSYMBOL) && !defined(fts5YYNOERRORRECOVERY)
+  fts5yyendofinput = (fts5yymajor==0);
+#endif
+  sqlite3Fts5ParserARG_STORE;
+
+#ifndef NDEBUG
+  if( fts5yyTraceFILE ){
+    fprintf(fts5yyTraceFILE,"%sInput '%s'\n",fts5yyTracePrompt,fts5yyTokenName[fts5yymajor]);
+  }
+#endif
+
+  do{
+    fts5yyact = fts5yy_find_shift_action(fts5yypParser,(fts5YYCODETYPE)fts5yymajor);
+    if( fts5yyact <= fts5YY_MAX_SHIFTREDUCE ){
+      fts5yy_shift(fts5yypParser,fts5yyact,fts5yymajor,fts5yyminor);
+#ifndef fts5YYNOERRORRECOVERY
+      fts5yypParser->fts5yyerrcnt--;
+#endif
+      fts5yymajor = fts5YYNOCODE;
+    }else if( fts5yyact <= fts5YY_MAX_REDUCE ){
+      fts5yy_reduce(fts5yypParser,fts5yyact-fts5YY_MIN_REDUCE);
+    }else{
+      assert( fts5yyact == fts5YY_ERROR_ACTION );
+      fts5yyminorunion.fts5yy0 = fts5yyminor;
+#ifdef fts5YYERRORSYMBOL
+      int fts5yymx;
+#endif
+#ifndef NDEBUG
+      if( fts5yyTraceFILE ){
+        fprintf(fts5yyTraceFILE,"%sSyntax Error!\n",fts5yyTracePrompt);
+      }
+#endif
+#ifdef fts5YYERRORSYMBOL
+      /* A syntax error has occurred.
+      ** The response to an error depends upon whether or not the
+      ** grammar defines an error token "ERROR".  
+      **
+      ** This is what we do if the grammar does define ERROR:
+      **
+      **  * Call the %syntax_error function.
+      **
+      **  * Begin popping the stack until we enter a state where
+      **    it is legal to shift the error symbol, then shift
+      **    the error symbol.
+      **
+      **  * Set the error count to three.
+      **
+      **  * Begin accepting and shifting new tokens.  No new error
+      **    processing will occur until three tokens have been
+      **    shifted successfully.
+      **
+      */
+      if( fts5yypParser->fts5yyerrcnt<0 ){
+        fts5yy_syntax_error(fts5yypParser,fts5yymajor,fts5yyminor);
+      }
+      fts5yymx = fts5yypParser->fts5yytos->major;
+      if( fts5yymx==fts5YYERRORSYMBOL || fts5yyerrorhit ){
+#ifndef NDEBUG
+        if( fts5yyTraceFILE ){
+          fprintf(fts5yyTraceFILE,"%sDiscard input token %s\n",
+             fts5yyTracePrompt,fts5yyTokenName[fts5yymajor]);
+        }
+#endif
+        fts5yy_destructor(fts5yypParser, (fts5YYCODETYPE)fts5yymajor, &fts5yyminorunion);
+        fts5yymajor = fts5YYNOCODE;
+      }else{
+        while( fts5yypParser->fts5yytos >= &fts5yypParser->fts5yystack
+            && fts5yymx != fts5YYERRORSYMBOL
+            && (fts5yyact = fts5yy_find_reduce_action(
+                        fts5yypParser->fts5yytos->stateno,
+                        fts5YYERRORSYMBOL)) >= fts5YY_MIN_REDUCE
+        ){
+          fts5yy_pop_parser_stack(fts5yypParser);
+        }
+        if( fts5yypParser->fts5yytos < fts5yypParser->fts5yystack || fts5yymajor==0 ){
+          fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);
+          fts5yy_parse_failed(fts5yypParser);
+#ifndef fts5YYNOERRORRECOVERY
+          fts5yypParser->fts5yyerrcnt = -1;
+#endif
+          fts5yymajor = fts5YYNOCODE;
+        }else if( fts5yymx!=fts5YYERRORSYMBOL ){
+          fts5yy_shift(fts5yypParser,fts5yyact,fts5YYERRORSYMBOL,fts5yyminor);
+        }
+      }
+      fts5yypParser->fts5yyerrcnt = 3;
+      fts5yyerrorhit = 1;
+#elif defined(fts5YYNOERRORRECOVERY)
+      /* If the fts5YYNOERRORRECOVERY macro is defined, then do not attempt to
+      ** do any kind of error recovery.  Instead, simply invoke the syntax
+      ** error routine and continue going as if nothing had happened.
+      **
+      ** Applications can set this macro (for example inside %include) if
+      ** they intend to abandon the parse upon the first syntax error seen.
+      */
+      fts5yy_syntax_error(fts5yypParser,fts5yymajor, fts5yyminor);
+      fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);
+      fts5yymajor = fts5YYNOCODE;
+      
+#else  /* fts5YYERRORSYMBOL is not defined */
+      /* This is what we do if the grammar does not define ERROR:
+      **
+      **  * Report an error message, and throw away the input token.
+      **
+      **  * If the input token is $, then fail the parse.
+      **
+      ** As before, subsequent error messages are suppressed until
+      ** three input tokens have been successfully shifted.
+      */
+      if( fts5yypParser->fts5yyerrcnt<=0 ){
+        fts5yy_syntax_error(fts5yypParser,fts5yymajor, fts5yyminor);
+      }
+      fts5yypParser->fts5yyerrcnt = 3;
+      fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);
+      if( fts5yyendofinput ){
+        fts5yy_parse_failed(fts5yypParser);
+#ifndef fts5YYNOERRORRECOVERY
+        fts5yypParser->fts5yyerrcnt = -1;
+#endif
+      }
+      fts5yymajor = fts5YYNOCODE;
+#endif
+    }
+  }while( fts5yymajor!=fts5YYNOCODE && fts5yypParser->fts5yytos>fts5yypParser->fts5yystack );
+#ifndef NDEBUG
+  if( fts5yyTraceFILE ){
+    fts5yyStackEntry *i;
+    char cDiv = '[';
+    fprintf(fts5yyTraceFILE,"%sReturn. Stack=",fts5yyTracePrompt);
+    for(i=&fts5yypParser->fts5yystack[1]; i<=fts5yypParser->fts5yytos; i++){
+      fprintf(fts5yyTraceFILE,"%c%s", cDiv, fts5yyTokenName[i->major]);
+      cDiv = ' ';
+    }
+    fprintf(fts5yyTraceFILE,"]\n");
+  }
+#endif
+  return;
+}
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+
+/* #include "fts5Int.h" */
+#include <math.h>                 /* amalgamator: keep */
+
+/*
+** Object used to iterate through all "coalesced phrase instances" in 
+** a single column of the current row. If the phrase instances in the
+** column being considered do not overlap, this object simply iterates
+** through them. Or, if they do overlap (share one or more tokens in
+** common), each set of overlapping instances is treated as a single
+** match. See documentation for the highlight() auxiliary function for
+** details.
+**
+** Usage is:
+**
+**   for(rc = fts5CInstIterNext(pApi, pFts, iCol, &iter);
+**      (rc==SQLITE_OK && 0==fts5CInstIterEof(&iter);
+**      rc = fts5CInstIterNext(&iter)
+**   ){
+**     printf("instance starts at %d, ends at %d\n", iter.iStart, iter.iEnd);
+**   }
+**
+*/
+typedef struct CInstIter CInstIter;
+struct CInstIter {
+  const Fts5ExtensionApi *pApi;   /* API offered by current FTS version */
+  Fts5Context *pFts;              /* First arg to pass to pApi functions */
+  int iCol;                       /* Column to search */
+  int iInst;                      /* Next phrase instance index */
+  int nInst;                      /* Total number of phrase instances */
+
+  /* Output variables */
+  int iStart;                     /* First token in coalesced phrase instance */
+  int iEnd;                       /* Last token in coalesced phrase instance */
+};
+
+/*
+** Advance the iterator to the next coalesced phrase instance. Return
+** an SQLite error code if an error occurs, or SQLITE_OK otherwise.
+*/
+static int fts5CInstIterNext(CInstIter *pIter){
+  int rc = SQLITE_OK;
+  pIter->iStart = -1;
+  pIter->iEnd = -1;
+
+  while( rc==SQLITE_OK && pIter->iInst<pIter->nInst ){
+    int ip; int ic; int io;
+    rc = pIter->pApi->xInst(pIter->pFts, pIter->iInst, &ip, &ic, &io);
+    if( rc==SQLITE_OK ){
+      if( ic==pIter->iCol ){
+        int iEnd = io - 1 + pIter->pApi->xPhraseSize(pIter->pFts, ip);
+        if( pIter->iStart<0 ){
+          pIter->iStart = io;
+          pIter->iEnd = iEnd;
+        }else if( io<=pIter->iEnd ){
+          if( iEnd>pIter->iEnd ) pIter->iEnd = iEnd;
+        }else{
+          break;
+        }
+      }
+      pIter->iInst++;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Initialize the iterator object indicated by the final parameter to 
+** iterate through coalesced phrase instances in column iCol.
+*/
+static int fts5CInstIterInit(
+  const Fts5ExtensionApi *pApi,
+  Fts5Context *pFts,
+  int iCol,
+  CInstIter *pIter
+){
+  int rc;
+
+  memset(pIter, 0, sizeof(CInstIter));
+  pIter->pApi = pApi;
+  pIter->pFts = pFts;
+  pIter->iCol = iCol;
+  rc = pApi->xInstCount(pFts, &pIter->nInst);
+
+  if( rc==SQLITE_OK ){
+    rc = fts5CInstIterNext(pIter);
+  }
+
+  return rc;
+}
+
+
+
+/*************************************************************************
+** Start of highlight() implementation.
+*/
+typedef struct HighlightContext HighlightContext;
+struct HighlightContext {
+  CInstIter iter;                 /* Coalesced Instance Iterator */
+  int iPos;                       /* Current token offset in zIn[] */
+  int iRangeStart;                /* First token to include */
+  int iRangeEnd;                  /* If non-zero, last token to include */
+  const char *zOpen;              /* Opening highlight */
+  const char *zClose;             /* Closing highlight */
+  const char *zIn;                /* Input text */
+  int nIn;                        /* Size of input text in bytes */
+  int iOff;                       /* Current offset within zIn[] */
+  char *zOut;                     /* Output value */
+};
+
+/*
+** Append text to the HighlightContext output string - p->zOut. Argument
+** z points to a buffer containing n bytes of text to append. If n is 
+** negative, everything up until the first '\0' is appended to the output.
+**
+** If *pRc is set to any value other than SQLITE_OK when this function is 
+** called, it is a no-op. If an error (i.e. an OOM condition) is encountered, 
+** *pRc is set to an error code before returning. 
+*/
+static void fts5HighlightAppend(
+  int *pRc, 
+  HighlightContext *p, 
+  const char *z, int n
+){
+  if( *pRc==SQLITE_OK ){
+    if( n<0 ) n = (int)strlen(z);
+    p->zOut = sqlite3_mprintf("%z%.*s", p->zOut, n, z);
+    if( p->zOut==0 ) *pRc = SQLITE_NOMEM;
+  }
+}
+
+/*
+** Tokenizer callback used by implementation of highlight() function.
+*/
+static int fts5HighlightCb(
+  void *pContext,                 /* Pointer to HighlightContext object */
+  int tflags,                     /* Mask of FTS5_TOKEN_* flags */
+  const char *pToken,             /* Buffer containing token */
+  int nToken,                     /* Size of token in bytes */
+  int iStartOff,                  /* Start offset of token */
+  int iEndOff                     /* End offset of token */
+){
+  HighlightContext *p = (HighlightContext*)pContext;
+  int rc = SQLITE_OK;
+  int iPos;
+
+  UNUSED_PARAM2(pToken, nToken);
+
+  if( tflags & FTS5_TOKEN_COLOCATED ) return SQLITE_OK;
+  iPos = p->iPos++;
+
+  if( p->iRangeEnd>0 ){
+    if( iPos<p->iRangeStart || iPos>p->iRangeEnd ) return SQLITE_OK;
+    if( p->iRangeStart && iPos==p->iRangeStart ) p->iOff = iStartOff;
+  }
+
+  if( iPos==p->iter.iStart ){
+    fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iStartOff - p->iOff);
+    fts5HighlightAppend(&rc, p, p->zOpen, -1);
+    p->iOff = iStartOff;
+  }
+
+  if( iPos==p->iter.iEnd ){
+    if( p->iRangeEnd && p->iter.iStart<p->iRangeStart ){
+      fts5HighlightAppend(&rc, p, p->zOpen, -1);
+    }
+    fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
+    fts5HighlightAppend(&rc, p, p->zClose, -1);
+    p->iOff = iEndOff;
+    if( rc==SQLITE_OK ){
+      rc = fts5CInstIterNext(&p->iter);
+    }
+  }
+
+  if( p->iRangeEnd>0 && iPos==p->iRangeEnd ){
+    fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
+    p->iOff = iEndOff;
+    if( iPos<p->iter.iEnd ){
+      fts5HighlightAppend(&rc, p, p->zClose, -1);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Implementation of highlight() function.
+*/
+static void fts5HighlightFunction(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+){
+  HighlightContext ctx;
+  int rc;
+  int iCol;
+
+  if( nVal!=3 ){
+    const char *zErr = "wrong number of arguments to function highlight()";
+    sqlite3_result_error(pCtx, zErr, -1);
+    return;
+  }
+
+  iCol = sqlite3_value_int(apVal[0]);
+  memset(&ctx, 0, sizeof(HighlightContext));
+  ctx.zOpen = (const char*)sqlite3_value_text(apVal[1]);
+  ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);
+  rc = pApi->xColumnText(pFts, iCol, &ctx.zIn, &ctx.nIn);
+
+  if( ctx.zIn ){
+    if( rc==SQLITE_OK ){
+      rc = fts5CInstIterInit(pApi, pFts, iCol, &ctx.iter);
+    }
+
+    if( rc==SQLITE_OK ){
+      rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx,fts5HighlightCb);
+    }
+    fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);
+
+    if( rc==SQLITE_OK ){
+      sqlite3_result_text(pCtx, (const char*)ctx.zOut, -1, SQLITE_TRANSIENT);
+    }
+    sqlite3_free(ctx.zOut);
+  }
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(pCtx, rc);
+  }
+}
+/*
+** End of highlight() implementation.
+**************************************************************************/
+
+/*
+** Implementation of snippet() function.
+*/
+static void fts5SnippetFunction(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+){
+  HighlightContext ctx;
+  int rc = SQLITE_OK;             /* Return code */
+  int iCol;                       /* 1st argument to snippet() */
+  const char *zEllips;            /* 4th argument to snippet() */
+  int nToken;                     /* 5th argument to snippet() */
+  int nInst = 0;                  /* Number of instance matches this row */
+  int i;                          /* Used to iterate through instances */
+  int nPhrase;                    /* Number of phrases in query */
+  unsigned char *aSeen;           /* Array of "seen instance" flags */
+  int iBestCol;                   /* Column containing best snippet */
+  int iBestStart = 0;             /* First token of best snippet */
+  int iBestLast;                  /* Last token of best snippet */
+  int nBestScore = 0;             /* Score of best snippet */
+  int nColSize = 0;               /* Total size of iBestCol in tokens */
+
+  if( nVal!=5 ){
+    const char *zErr = "wrong number of arguments to function snippet()";
+    sqlite3_result_error(pCtx, zErr, -1);
+    return;
+  }
+
+  memset(&ctx, 0, sizeof(HighlightContext));
+  iCol = sqlite3_value_int(apVal[0]);
+  ctx.zOpen = (const char*)sqlite3_value_text(apVal[1]);
+  ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);
+  zEllips = (const char*)sqlite3_value_text(apVal[3]);
+  nToken = sqlite3_value_int(apVal[4]);
+  iBestLast = nToken-1;
+
+  iBestCol = (iCol>=0 ? iCol : 0);
+  nPhrase = pApi->xPhraseCount(pFts);
+  aSeen = sqlite3_malloc(nPhrase);
+  if( aSeen==0 ){
+    rc = SQLITE_NOMEM;
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = pApi->xInstCount(pFts, &nInst);
+  }
+  for(i=0; rc==SQLITE_OK && i<nInst; i++){
+    int ip, iSnippetCol, iStart;
+    memset(aSeen, 0, nPhrase);
+    rc = pApi->xInst(pFts, i, &ip, &iSnippetCol, &iStart);
+    if( rc==SQLITE_OK && (iCol<0 || iSnippetCol==iCol) ){
+      int nScore = 1000;
+      int iLast = iStart - 1 + pApi->xPhraseSize(pFts, ip);
+      int j;
+      aSeen[ip] = 1;
+
+      for(j=i+1; rc==SQLITE_OK && j<nInst; j++){
+        int ic; int io; int iFinal;
+        rc = pApi->xInst(pFts, j, &ip, &ic, &io);
+        iFinal = io + pApi->xPhraseSize(pFts, ip) - 1;
+        if( rc==SQLITE_OK && ic==iSnippetCol && iLast<iStart+nToken ){
+          nScore += aSeen[ip] ? 1000 : 1;
+          aSeen[ip] = 1;
+          if( iFinal>iLast ) iLast = iFinal;
+        }
+      }
+
+      if( rc==SQLITE_OK && nScore>nBestScore ){
+        iBestCol = iSnippetCol;
+        iBestStart = iStart;
+        iBestLast = iLast;
+        nBestScore = nScore;
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = pApi->xColumnSize(pFts, iBestCol, &nColSize);
+  }
+  if( rc==SQLITE_OK ){
+    rc = pApi->xColumnText(pFts, iBestCol, &ctx.zIn, &ctx.nIn);
+  }
+  if( ctx.zIn ){
+    if( rc==SQLITE_OK ){
+      rc = fts5CInstIterInit(pApi, pFts, iBestCol, &ctx.iter);
+    }
+
+    if( (iBestStart+nToken-1)>iBestLast ){
+      iBestStart -= (iBestStart+nToken-1-iBestLast) / 2;
+    }
+    if( iBestStart+nToken>nColSize ){
+      iBestStart = nColSize - nToken;
+    }
+    if( iBestStart<0 ) iBestStart = 0;
+
+    ctx.iRangeStart = iBestStart;
+    ctx.iRangeEnd = iBestStart + nToken - 1;
+
+    if( iBestStart>0 ){
+      fts5HighlightAppend(&rc, &ctx, zEllips, -1);
+    }
+    if( rc==SQLITE_OK ){
+      rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx,fts5HighlightCb);
+    }
+    if( ctx.iRangeEnd>=(nColSize-1) ){
+      fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);
+    }else{
+      fts5HighlightAppend(&rc, &ctx, zEllips, -1);
+    }
+
+    if( rc==SQLITE_OK ){
+      sqlite3_result_text(pCtx, (const char*)ctx.zOut, -1, SQLITE_TRANSIENT);
+    }else{
+      sqlite3_result_error_code(pCtx, rc);
+    }
+    sqlite3_free(ctx.zOut);
+  }
+  sqlite3_free(aSeen);
+}
+
+/************************************************************************/
+
+/*
+** The first time the bm25() function is called for a query, an instance
+** of the following structure is allocated and populated.
+*/
+typedef struct Fts5Bm25Data Fts5Bm25Data;
+struct Fts5Bm25Data {
+  int nPhrase;                    /* Number of phrases in query */
+  double avgdl;                   /* Average number of tokens in each row */
+  double *aIDF;                   /* IDF for each phrase */
+  double *aFreq;                  /* Array used to calculate phrase freq. */
+};
+
+/*
+** Callback used by fts5Bm25GetData() to count the number of rows in the
+** table matched by each individual phrase within the query.
+*/
+static int fts5CountCb(
+  const Fts5ExtensionApi *pApi, 
+  Fts5Context *pFts,
+  void *pUserData                 /* Pointer to sqlite3_int64 variable */
+){
+  sqlite3_int64 *pn = (sqlite3_int64*)pUserData;
+  UNUSED_PARAM2(pApi, pFts);
+  (*pn)++;
+  return SQLITE_OK;
+}
+
+/*
+** Set *ppData to point to the Fts5Bm25Data object for the current query. 
+** If the object has not already been allocated, allocate and populate it
+** now.
+*/
+static int fts5Bm25GetData(
+  const Fts5ExtensionApi *pApi, 
+  Fts5Context *pFts,
+  Fts5Bm25Data **ppData           /* OUT: bm25-data object for this query */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5Bm25Data *p;                /* Object to return */
+
+  p = pApi->xGetAuxdata(pFts, 0);
+  if( p==0 ){
+    int nPhrase;                  /* Number of phrases in query */
+    sqlite3_int64 nRow = 0;       /* Number of rows in table */
+    sqlite3_int64 nToken = 0;     /* Number of tokens in table */
+    int nByte;                    /* Bytes of space to allocate */
+    int i;
+
+    /* Allocate the Fts5Bm25Data object */
+    nPhrase = pApi->xPhraseCount(pFts);
+    nByte = sizeof(Fts5Bm25Data) + nPhrase*2*sizeof(double);
+    p = (Fts5Bm25Data*)sqlite3_malloc(nByte);
+    if( p==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(p, 0, nByte);
+      p->nPhrase = nPhrase;
+      p->aIDF = (double*)&p[1];
+      p->aFreq = &p->aIDF[nPhrase];
+    }
+
+    /* Calculate the average document length for this FTS5 table */
+    if( rc==SQLITE_OK ) rc = pApi->xRowCount(pFts, &nRow);
+    if( rc==SQLITE_OK ) rc = pApi->xColumnTotalSize(pFts, -1, &nToken);
+    if( rc==SQLITE_OK ) p->avgdl = (double)nToken  / (double)nRow;
+
+    /* Calculate an IDF for each phrase in the query */
+    for(i=0; rc==SQLITE_OK && i<nPhrase; i++){
+      sqlite3_int64 nHit = 0;
+      rc = pApi->xQueryPhrase(pFts, i, (void*)&nHit, fts5CountCb);
+      if( rc==SQLITE_OK ){
+        /* Calculate the IDF (Inverse Document Frequency) for phrase i.
+        ** This is done using the standard BM25 formula as found on wikipedia:
+        **
+        **   IDF = log( (N - nHit + 0.5) / (nHit + 0.5) )
+        **
+        ** where "N" is the total number of documents in the set and nHit
+        ** is the number that contain at least one instance of the phrase
+        ** under consideration.
+        **
+        ** The problem with this is that if (N < 2*nHit), the IDF is 
+        ** negative. Which is undesirable. So the mimimum allowable IDF is
+        ** (1e-6) - roughly the same as a term that appears in just over
+        ** half of set of 5,000,000 documents.  */
+        double idf = log( (nRow - nHit + 0.5) / (nHit + 0.5) );
+        if( idf<=0.0 ) idf = 1e-6;
+        p->aIDF[i] = idf;
+      }
+    }
+
+    if( rc!=SQLITE_OK ){
+      sqlite3_free(p);
+    }else{
+      rc = pApi->xSetAuxdata(pFts, p, sqlite3_free);
+    }
+    if( rc!=SQLITE_OK ) p = 0;
+  }
+  *ppData = p;
+  return rc;
+}
+
+/*
+** Implementation of bm25() function.
+*/
+static void fts5Bm25Function(
+  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
+  Fts5Context *pFts,              /* First arg to pass to pApi functions */
+  sqlite3_context *pCtx,          /* Context for returning result/error */
+  int nVal,                       /* Number of values in apVal[] array */
+  sqlite3_value **apVal           /* Array of trailing arguments */
+){
+  const double k1 = 1.2;          /* Constant "k1" from BM25 formula */
+  const double b = 0.75;          /* Constant "b" from BM25 formula */
+  int rc = SQLITE_OK;             /* Error code */
+  double score = 0.0;             /* SQL function return value */
+  Fts5Bm25Data *pData;            /* Values allocated/calculated once only */
+  int i;                          /* Iterator variable */
+  int nInst = 0;                  /* Value returned by xInstCount() */
+  double D = 0.0;                 /* Total number of tokens in row */
+  double *aFreq = 0;              /* Array of phrase freq. for current row */
+
+  /* Calculate the phrase frequency (symbol "f(qi,D)" in the documentation)
+  ** for each phrase in the query for the current row. */
+  rc = fts5Bm25GetData(pApi, pFts, &pData);
+  if( rc==SQLITE_OK ){
+    aFreq = pData->aFreq;
+    memset(aFreq, 0, sizeof(double) * pData->nPhrase);
+    rc = pApi->xInstCount(pFts, &nInst);
+  }
+  for(i=0; rc==SQLITE_OK && i<nInst; i++){
+    int ip; int ic; int io;
+    rc = pApi->xInst(pFts, i, &ip, &ic, &io);
+    if( rc==SQLITE_OK ){
+      double w = (nVal > ic) ? sqlite3_value_double(apVal[ic]) : 1.0;
+      aFreq[ip] += w;
+    }
+  }
+
+  /* Figure out the total size of the current row in tokens. */
+  if( rc==SQLITE_OK ){
+    int nTok;
+    rc = pApi->xColumnSize(pFts, -1, &nTok);
+    D = (double)nTok;
+  }
+
+  /* Determine the BM25 score for the current row. */
+  for(i=0; rc==SQLITE_OK && i<pData->nPhrase; i++){
+    score += pData->aIDF[i] * (
+      ( aFreq[i] * (k1 + 1.0) ) / 
+      ( aFreq[i] + k1 * (1 - b + b * D / pData->avgdl) )
+    );
+  }
+  
+  /* If no error has occurred, return the calculated score. Otherwise,
+  ** throw an SQL exception.  */
+  if( rc==SQLITE_OK ){
+    sqlite3_result_double(pCtx, -1.0 * score);
+  }else{
+    sqlite3_result_error_code(pCtx, rc);
+  }
+}
+
+static int sqlite3Fts5AuxInit(fts5_api *pApi){
+  struct Builtin {
+    const char *zFunc;            /* Function name (nul-terminated) */
+    void *pUserData;              /* User-data pointer */
+    fts5_extension_function xFunc;/* Callback function */
+    void (*xDestroy)(void*);      /* Destructor function */
+  } aBuiltin [] = {
+    { "snippet",   0, fts5SnippetFunction, 0 },
+    { "highlight", 0, fts5HighlightFunction, 0 },
+    { "bm25",      0, fts5Bm25Function,    0 },
+  };
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* To iterate through builtin functions */
+
+  for(i=0; rc==SQLITE_OK && i<ArraySize(aBuiltin); i++){
+    rc = pApi->xCreateFunction(pApi,
+        aBuiltin[i].zFunc,
+        aBuiltin[i].pUserData,
+        aBuiltin[i].xFunc,
+        aBuiltin[i].xDestroy
+    );
+  }
+
+  return rc;
+}
+
+
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+
+
+/* #include "fts5Int.h" */
+
+static int sqlite3Fts5BufferSize(int *pRc, Fts5Buffer *pBuf, u32 nByte){
+  if( (u32)pBuf->nSpace<nByte ){
+    u32 nNew = pBuf->nSpace ? pBuf->nSpace : 64;
+    u8 *pNew;
+    while( nNew<nByte ){
+      nNew = nNew * 2;
+    }
+    pNew = sqlite3_realloc(pBuf->p, nNew);
+    if( pNew==0 ){
+      *pRc = SQLITE_NOMEM;
+      return 1;
+    }else{
+      pBuf->nSpace = nNew;
+      pBuf->p = pNew;
+    }
+  }
+  return 0;
+}
+
+
+/*
+** Encode value iVal as an SQLite varint and append it to the buffer object
+** pBuf. If an OOM error occurs, set the error code in p.
+*/
+static void sqlite3Fts5BufferAppendVarint(int *pRc, Fts5Buffer *pBuf, i64 iVal){
+  if( fts5BufferGrow(pRc, pBuf, 9) ) return;
+  pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iVal);
+}
+
+static void sqlite3Fts5Put32(u8 *aBuf, int iVal){
+  aBuf[0] = (iVal>>24) & 0x00FF;
+  aBuf[1] = (iVal>>16) & 0x00FF;
+  aBuf[2] = (iVal>> 8) & 0x00FF;
+  aBuf[3] = (iVal>> 0) & 0x00FF;
+}
+
+static int sqlite3Fts5Get32(const u8 *aBuf){
+  return (aBuf[0] << 24) + (aBuf[1] << 16) + (aBuf[2] << 8) + aBuf[3];
+}
+
+/*
+** Append buffer nData/pData to buffer pBuf. If an OOM error occurs, set 
+** the error code in p. If an error has already occurred when this function
+** is called, it is a no-op.
+*/
+static void sqlite3Fts5BufferAppendBlob(
+  int *pRc,
+  Fts5Buffer *pBuf, 
+  u32 nData, 
+  const u8 *pData
+){
+  assert_nc( *pRc || nData>=0 );
+  if( fts5BufferGrow(pRc, pBuf, nData) ) return;
+  memcpy(&pBuf->p[pBuf->n], pData, nData);
+  pBuf->n += nData;
+}
+
+/*
+** Append the nul-terminated string zStr to the buffer pBuf. This function
+** ensures that the byte following the buffer data is set to 0x00, even 
+** though this byte is not included in the pBuf->n count.
+*/
+static void sqlite3Fts5BufferAppendString(
+  int *pRc,
+  Fts5Buffer *pBuf, 
+  const char *zStr
+){
+  int nStr = (int)strlen(zStr);
+  sqlite3Fts5BufferAppendBlob(pRc, pBuf, nStr+1, (const u8*)zStr);
+  pBuf->n--;
+}
+
+/*
+** Argument zFmt is a printf() style format string. This function performs
+** the printf() style processing, then appends the results to buffer pBuf.
+**
+** Like sqlite3Fts5BufferAppendString(), this function ensures that the byte 
+** following the buffer data is set to 0x00, even though this byte is not
+** included in the pBuf->n count.
+*/ 
+static void sqlite3Fts5BufferAppendPrintf(
+  int *pRc,
+  Fts5Buffer *pBuf, 
+  char *zFmt, ...
+){
+  if( *pRc==SQLITE_OK ){
+    char *zTmp;
+    va_list ap;
+    va_start(ap, zFmt);
+    zTmp = sqlite3_vmprintf(zFmt, ap);
+    va_end(ap);
+
+    if( zTmp==0 ){
+      *pRc = SQLITE_NOMEM;
+    }else{
+      sqlite3Fts5BufferAppendString(pRc, pBuf, zTmp);
+      sqlite3_free(zTmp);
+    }
+  }
+}
+
+static char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...){
+  char *zRet = 0;
+  if( *pRc==SQLITE_OK ){
+    va_list ap;
+    va_start(ap, zFmt);
+    zRet = sqlite3_vmprintf(zFmt, ap);
+    va_end(ap);
+    if( zRet==0 ){
+      *pRc = SQLITE_NOMEM; 
+    }
+  }
+  return zRet;
+}
+ 
+
+/*
+** Free any buffer allocated by pBuf. Zero the structure before returning.
+*/
+static void sqlite3Fts5BufferFree(Fts5Buffer *pBuf){
+  sqlite3_free(pBuf->p);
+  memset(pBuf, 0, sizeof(Fts5Buffer));
+}
+
+/*
+** Zero the contents of the buffer object. But do not free the associated 
+** memory allocation.
+*/
+static void sqlite3Fts5BufferZero(Fts5Buffer *pBuf){
+  pBuf->n = 0;
+}
+
+/*
+** Set the buffer to contain nData/pData. If an OOM error occurs, leave an
+** the error code in p. If an error has already occurred when this function
+** is called, it is a no-op.
+*/
+static void sqlite3Fts5BufferSet(
+  int *pRc,
+  Fts5Buffer *pBuf, 
+  int nData, 
+  const u8 *pData
+){
+  pBuf->n = 0;
+  sqlite3Fts5BufferAppendBlob(pRc, pBuf, nData, pData);
+}
+
+static int sqlite3Fts5PoslistNext64(
+  const u8 *a, int n,             /* Buffer containing poslist */
+  int *pi,                        /* IN/OUT: Offset within a[] */
+  i64 *piOff                      /* IN/OUT: Current offset */
+){
+  int i = *pi;
+  if( i>=n ){
+    /* EOF */
+    *piOff = -1;
+    return 1;  
+  }else{
+    i64 iOff = *piOff;
+    int iVal;
+    fts5FastGetVarint32(a, i, iVal);
+    if( iVal==1 ){
+      fts5FastGetVarint32(a, i, iVal);
+      iOff = ((i64)iVal) << 32;
+      fts5FastGetVarint32(a, i, iVal);
+    }
+    *piOff = iOff + (iVal-2);
+    *pi = i;
+    return 0;
+  }
+}
+
+
+/*
+** Advance the iterator object passed as the only argument. Return true
+** if the iterator reaches EOF, or false otherwise.
+*/
+static int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader *pIter){
+  if( sqlite3Fts5PoslistNext64(pIter->a, pIter->n, &pIter->i, &pIter->iPos) ){
+    pIter->bEof = 1;
+  }
+  return pIter->bEof;
+}
+
+static int sqlite3Fts5PoslistReaderInit(
+  const u8 *a, int n,             /* Poslist buffer to iterate through */
+  Fts5PoslistReader *pIter        /* Iterator object to initialize */
+){
+  memset(pIter, 0, sizeof(*pIter));
+  pIter->a = a;
+  pIter->n = n;
+  sqlite3Fts5PoslistReaderNext(pIter);
+  return pIter->bEof;
+}
+
+/*
+** Append position iPos to the position list being accumulated in buffer
+** pBuf, which must be already be large enough to hold the new data.
+** The previous position written to this list is *piPrev. *piPrev is set
+** to iPos before returning.
+*/
+static void sqlite3Fts5PoslistSafeAppend(
+  Fts5Buffer *pBuf, 
+  i64 *piPrev, 
+  i64 iPos
+){
+  static const i64 colmask = ((i64)(0x7FFFFFFF)) << 32;
+  if( (iPos & colmask) != (*piPrev & colmask) ){
+    pBuf->p[pBuf->n++] = 1;
+    pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos>>32));
+    *piPrev = (iPos & colmask);
+  }
+  pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos-*piPrev)+2);
+  *piPrev = iPos;
+}
+
+static int sqlite3Fts5PoslistWriterAppend(
+  Fts5Buffer *pBuf, 
+  Fts5PoslistWriter *pWriter,
+  i64 iPos
+){
+  int rc = 0;   /* Initialized only to suppress erroneous warning from Clang */
+  if( fts5BufferGrow(&rc, pBuf, 5+5+5) ) return rc;
+  sqlite3Fts5PoslistSafeAppend(pBuf, &pWriter->iPrev, iPos);
+  return SQLITE_OK;
+}
+
+static void *sqlite3Fts5MallocZero(int *pRc, int nByte){
+  void *pRet = 0;
+  if( *pRc==SQLITE_OK ){
+    pRet = sqlite3_malloc(nByte);
+    if( pRet==0 && nByte>0 ){
+      *pRc = SQLITE_NOMEM;
+    }else{
+      memset(pRet, 0, nByte);
+    }
+  }
+  return pRet;
+}
+
+/*
+** Return a nul-terminated copy of the string indicated by pIn. If nIn
+** is non-negative, then it is the length of the string in bytes. Otherwise,
+** the length of the string is determined using strlen().
+**
+** It is the responsibility of the caller to eventually free the returned
+** buffer using sqlite3_free(). If an OOM error occurs, NULL is returned. 
+*/
+static char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn){
+  char *zRet = 0;
+  if( *pRc==SQLITE_OK ){
+    if( nIn<0 ){
+      nIn = (int)strlen(pIn);
+    }
+    zRet = (char*)sqlite3_malloc(nIn+1);
+    if( zRet ){
+      memcpy(zRet, pIn, nIn);
+      zRet[nIn] = '\0';
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+  return zRet;
+}
+
+
+/*
+** Return true if character 't' may be part of an FTS5 bareword, or false
+** otherwise. Characters that may be part of barewords:
+**
+**   * All non-ASCII characters,
+**   * The 52 upper and lower case ASCII characters, and
+**   * The 10 integer ASCII characters.
+**   * The underscore character "_" (0x5F).
+**   * The unicode "subsitute" character (0x1A).
+*/
+static int sqlite3Fts5IsBareword(char t){
+  u8 aBareword[128] = {
+    0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 0, 0, 0, 0, 0, 0,   /* 0x00 .. 0x0F */
+    0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 1, 0, 0, 0, 0, 0,   /* 0x10 .. 0x1F */
+    0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 0, 0, 0, 0, 0, 0,   /* 0x20 .. 0x2F */
+    1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 0, 0, 0, 0, 0, 0,   /* 0x30 .. 0x3F */
+    0, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 1, 1, 1, 1, 1,   /* 0x40 .. 0x4F */
+    1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 0, 0, 0, 0, 1,   /* 0x50 .. 0x5F */
+    0, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 1, 1, 1, 1, 1,   /* 0x60 .. 0x6F */
+    1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 0, 0, 0, 0, 0    /* 0x70 .. 0x7F */
+  };
+
+  return (t & 0x80) || aBareword[(int)t];
+}
+
+
+/*************************************************************************
+*/
+typedef struct Fts5TermsetEntry Fts5TermsetEntry;
+struct Fts5TermsetEntry {
+  char *pTerm;
+  int nTerm;
+  int iIdx;                       /* Index (main or aPrefix[] entry) */
+  Fts5TermsetEntry *pNext;
+};
+
+struct Fts5Termset {
+  Fts5TermsetEntry *apHash[512];
+};
+
+static int sqlite3Fts5TermsetNew(Fts5Termset **pp){
+  int rc = SQLITE_OK;
+  *pp = sqlite3Fts5MallocZero(&rc, sizeof(Fts5Termset));
+  return rc;
+}
+
+static int sqlite3Fts5TermsetAdd(
+  Fts5Termset *p, 
+  int iIdx,
+  const char *pTerm, int nTerm, 
+  int *pbPresent
+){
+  int rc = SQLITE_OK;
+  *pbPresent = 0;
+  if( p ){
+    int i;
+    u32 hash = 13;
+    Fts5TermsetEntry *pEntry;
+
+    /* Calculate a hash value for this term. This is the same hash checksum
+    ** used by the fts5_hash.c module. This is not important for correct
+    ** operation of the module, but is necessary to ensure that some tests
+    ** designed to produce hash table collisions really do work.  */
+    for(i=nTerm-1; i>=0; i--){
+      hash = (hash << 3) ^ hash ^ pTerm[i];
+    }
+    hash = (hash << 3) ^ hash ^ iIdx;
+    hash = hash % ArraySize(p->apHash);
+
+    for(pEntry=p->apHash[hash]; pEntry; pEntry=pEntry->pNext){
+      if( pEntry->iIdx==iIdx 
+          && pEntry->nTerm==nTerm 
+          && memcmp(pEntry->pTerm, pTerm, nTerm)==0 
+      ){
+        *pbPresent = 1;
+        break;
+      }
+    }
+
+    if( pEntry==0 ){
+      pEntry = sqlite3Fts5MallocZero(&rc, sizeof(Fts5TermsetEntry) + nTerm);
+      if( pEntry ){
+        pEntry->pTerm = (char*)&pEntry[1];
+        pEntry->nTerm = nTerm;
+        pEntry->iIdx = iIdx;
+        memcpy(pEntry->pTerm, pTerm, nTerm);
+        pEntry->pNext = p->apHash[hash];
+        p->apHash[hash] = pEntry;
+      }
+    }
+  }
+
+  return rc;
+}
+
+static void sqlite3Fts5TermsetFree(Fts5Termset *p){
+  if( p ){
+    u32 i;
+    for(i=0; i<ArraySize(p->apHash); i++){
+      Fts5TermsetEntry *pEntry = p->apHash[i];
+      while( pEntry ){
+        Fts5TermsetEntry *pDel = pEntry;
+        pEntry = pEntry->pNext;
+        sqlite3_free(pDel);
+      }
+    }
+    sqlite3_free(p);
+  }
+}
+
+/*
+** 2014 Jun 09
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is an SQLite module implementing full-text search.
+*/
+
+
+/* #include "fts5Int.h" */
+
+#define FTS5_DEFAULT_PAGE_SIZE   4050
+#define FTS5_DEFAULT_AUTOMERGE      4
+#define FTS5_DEFAULT_USERMERGE      4
+#define FTS5_DEFAULT_CRISISMERGE   16
+#define FTS5_DEFAULT_HASHSIZE    (1024*1024)
+
+/* Maximum allowed page size */
+#define FTS5_MAX_PAGE_SIZE (128*1024)
+
+static int fts5_iswhitespace(char x){
+  return (x==' ');
+}
+
+static int fts5_isopenquote(char x){
+  return (x=='"' || x=='\'' || x=='[' || x=='`');
+}
+
+/*
+** Argument pIn points to a character that is part of a nul-terminated 
+** string. Return a pointer to the first character following *pIn in 
+** the string that is not a white-space character.
+*/
+static const char *fts5ConfigSkipWhitespace(const char *pIn){
+  const char *p = pIn;
+  if( p ){
+    while( fts5_iswhitespace(*p) ){ p++; }
+  }
+  return p;
+}
+
+/*
+** Argument pIn points to a character that is part of a nul-terminated 
+** string. Return a pointer to the first character following *pIn in 
+** the string that is not a "bareword" character.
+*/
+static const char *fts5ConfigSkipBareword(const char *pIn){
+  const char *p = pIn;
+  while ( sqlite3Fts5IsBareword(*p) ) p++;
+  if( p==pIn ) p = 0;
+  return p;
+}
+
+static int fts5_isdigit(char a){
+  return (a>='0' && a<='9');
+}
+
+
+
+static const char *fts5ConfigSkipLiteral(const char *pIn){
+  const char *p = pIn;
+  switch( *p ){
+    case 'n': case 'N':
+      if( sqlite3_strnicmp("null", p, 4)==0 ){
+        p = &p[4];
+      }else{
+        p = 0;
+      }
+      break;
+
+    case 'x': case 'X':
+      p++;
+      if( *p=='\'' ){
+        p++;
+        while( (*p>='a' && *p<='f') 
+            || (*p>='A' && *p<='F') 
+            || (*p>='0' && *p<='9') 
+            ){
+          p++;
+        }
+        if( *p=='\'' && 0==((p-pIn)%2) ){
+          p++;
+        }else{
+          p = 0;
+        }
+      }else{
+        p = 0;
+      }
+      break;
+
+    case '\'':
+      p++;
+      while( p ){
+        if( *p=='\'' ){
+          p++;
+          if( *p!='\'' ) break;
+        }
+        p++;
+        if( *p==0 ) p = 0;
+      }
+      break;
+
+    default:
+      /* maybe a number */
+      if( *p=='+' || *p=='-' ) p++;
+      while( fts5_isdigit(*p) ) p++;
+
+      /* At this point, if the literal was an integer, the parse is 
+      ** finished. Or, if it is a floating point value, it may continue
+      ** with either a decimal point or an 'E' character. */
+      if( *p=='.' && fts5_isdigit(p[1]) ){
+        p += 2;
+        while( fts5_isdigit(*p) ) p++;
+      }
+      if( p==pIn ) p = 0;
+
+      break;
+  }
+
+  return p;
+}
+
+/*
+** The first character of the string pointed to by argument z is guaranteed
+** to be an open-quote character (see function fts5_isopenquote()).
+**
+** This function searches for the corresponding close-quote character within
+** the string and, if found, dequotes the string in place and adds a new
+** nul-terminator byte.
+**
+** If the close-quote is found, the value returned is the byte offset of
+** the character immediately following it. Or, if the close-quote is not 
+** found, -1 is returned. If -1 is returned, the buffer is left in an 
+** undefined state.
+*/
+static int fts5Dequote(char *z){
+  char q;
+  int iIn = 1;
+  int iOut = 0;
+  q = z[0];
+
+  /* Set stack variable q to the close-quote character */
+  assert( q=='[' || q=='\'' || q=='"' || q=='`' );
+  if( q=='[' ) q = ']';  
+
+  while( ALWAYS(z[iIn]) ){
+    if( z[iIn]==q ){
+      if( z[iIn+1]!=q ){
+        /* Character iIn was the close quote. */
+        iIn++;
+        break;
+      }else{
+        /* Character iIn and iIn+1 form an escaped quote character. Skip
+        ** the input cursor past both and copy a single quote character 
+        ** to the output buffer. */
+        iIn += 2;
+        z[iOut++] = q;
+      }
+    }else{
+      z[iOut++] = z[iIn++];
+    }
+  }
+
+  z[iOut] = '\0';
+  return iIn;
+}
+
+/*
+** Convert an SQL-style quoted string into a normal string by removing
+** the quote characters.  The conversion is done in-place.  If the
+** input does not begin with a quote character, then this routine
+** is a no-op.
+**
+** Examples:
+**
+**     "abc"   becomes   abc
+**     'xyz'   becomes   xyz
+**     [pqr]   becomes   pqr
+**     `mno`   becomes   mno
+*/
+static void sqlite3Fts5Dequote(char *z){
+  char quote;                     /* Quote character (if any ) */
+
+  assert( 0==fts5_iswhitespace(z[0]) );
+  quote = z[0];
+  if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
+    fts5Dequote(z);
+  }
+}
+
+
+struct Fts5Enum {
+  const char *zName;
+  int eVal;
+};
+typedef struct Fts5Enum Fts5Enum;
+
+static int fts5ConfigSetEnum(
+  const Fts5Enum *aEnum, 
+  const char *zEnum, 
+  int *peVal
+){
+  int nEnum = (int)strlen(zEnum);
+  int i;
+  int iVal = -1;
+
+  for(i=0; aEnum[i].zName; i++){
+    if( sqlite3_strnicmp(aEnum[i].zName, zEnum, nEnum)==0 ){
+      if( iVal>=0 ) return SQLITE_ERROR;
+      iVal = aEnum[i].eVal;
+    }
+  }
+
+  *peVal = iVal;
+  return iVal<0 ? SQLITE_ERROR : SQLITE_OK;
+}
+
+/*
+** Parse a "special" CREATE VIRTUAL TABLE directive and update
+** configuration object pConfig as appropriate.
+**
+** If successful, object pConfig is updated and SQLITE_OK returned. If
+** an error occurs, an SQLite error code is returned and an error message
+** may be left in *pzErr. It is the responsibility of the caller to
+** eventually free any such error message using sqlite3_free().
+*/
+static int fts5ConfigParseSpecial(
+  Fts5Global *pGlobal,
+  Fts5Config *pConfig,            /* Configuration object to update */
+  const char *zCmd,               /* Special command to parse */
+  const char *zArg,               /* Argument to parse */
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc = SQLITE_OK;
+  int nCmd = (int)strlen(zCmd);
+  if( sqlite3_strnicmp("prefix", zCmd, nCmd)==0 ){
+    const int nByte = sizeof(int) * FTS5_MAX_PREFIX_INDEXES;
+    const char *p;
+    int bFirst = 1;
+    if( pConfig->aPrefix==0 ){
+      pConfig->aPrefix = sqlite3Fts5MallocZero(&rc, nByte);
+      if( rc ) return rc;
+    }
+
+    p = zArg;
+    while( 1 ){
+      int nPre = 0;
+
+      while( p[0]==' ' ) p++;
+      if( bFirst==0 && p[0]==',' ){
+        p++;
+        while( p[0]==' ' ) p++;
+      }else if( p[0]=='\0' ){
+        break;
+      }
+      if( p[0]<'0' || p[0]>'9' ){
+        *pzErr = sqlite3_mprintf("malformed prefix=... directive");
+        rc = SQLITE_ERROR;
+        break;
+      }
+
+      if( pConfig->nPrefix==FTS5_MAX_PREFIX_INDEXES ){
+        *pzErr = sqlite3_mprintf(
+            "too many prefix indexes (max %d)", FTS5_MAX_PREFIX_INDEXES
+        );
+        rc = SQLITE_ERROR;
+        break;
+      }
+
+      while( p[0]>='0' && p[0]<='9' && nPre<1000 ){
+        nPre = nPre*10 + (p[0] - '0');
+        p++;
+      }
+
+      if( nPre<=0 || nPre>=1000 ){
+        *pzErr = sqlite3_mprintf("prefix length out of range (max 999)");
+        rc = SQLITE_ERROR;
+        break;
+      }
+
+      pConfig->aPrefix[pConfig->nPrefix] = nPre;
+      pConfig->nPrefix++;
+      bFirst = 0;
+    }
+    assert( pConfig->nPrefix<=FTS5_MAX_PREFIX_INDEXES );
+    return rc;
+  }
+
+  if( sqlite3_strnicmp("tokenize", zCmd, nCmd)==0 ){
+    const char *p = (const char*)zArg;
+    int nArg = (int)strlen(zArg) + 1;
+    char **azArg = sqlite3Fts5MallocZero(&rc, sizeof(char*) * nArg);
+    char *pDel = sqlite3Fts5MallocZero(&rc, nArg * 2);
+    char *pSpace = pDel;
+
+    if( azArg && pSpace ){
+      if( pConfig->pTok ){
+        *pzErr = sqlite3_mprintf("multiple tokenize=... directives");
+        rc = SQLITE_ERROR;
+      }else{
+        for(nArg=0; p && *p; nArg++){
+          const char *p2 = fts5ConfigSkipWhitespace(p);
+          if( *p2=='\'' ){
+            p = fts5ConfigSkipLiteral(p2);
+          }else{
+            p = fts5ConfigSkipBareword(p2);
+          }
+          if( p ){
+            memcpy(pSpace, p2, p-p2);
+            azArg[nArg] = pSpace;
+            sqlite3Fts5Dequote(pSpace);
+            pSpace += (p - p2) + 1;
+            p = fts5ConfigSkipWhitespace(p);
+          }
+        }
+        if( p==0 ){
+          *pzErr = sqlite3_mprintf("parse error in tokenize directive");
+          rc = SQLITE_ERROR;
+        }else{
+          rc = sqlite3Fts5GetTokenizer(pGlobal, 
+              (const char**)azArg, nArg, &pConfig->pTok, &pConfig->pTokApi,
+              pzErr
+          );
+        }
+      }
+    }
+
+    sqlite3_free(azArg);
+    sqlite3_free(pDel);
+    return rc;
+  }
+
+  if( sqlite3_strnicmp("content", zCmd, nCmd)==0 ){
+    if( pConfig->eContent!=FTS5_CONTENT_NORMAL ){
+      *pzErr = sqlite3_mprintf("multiple content=... directives");
+      rc = SQLITE_ERROR;
+    }else{
+      if( zArg[0] ){
+        pConfig->eContent = FTS5_CONTENT_EXTERNAL;
+        pConfig->zContent = sqlite3Fts5Mprintf(&rc, "%Q.%Q", pConfig->zDb,zArg);
+      }else{
+        pConfig->eContent = FTS5_CONTENT_NONE;
+      }
+    }
+    return rc;
+  }
+
+  if( sqlite3_strnicmp("content_rowid", zCmd, nCmd)==0 ){
+    if( pConfig->zContentRowid ){
+      *pzErr = sqlite3_mprintf("multiple content_rowid=... directives");
+      rc = SQLITE_ERROR;
+    }else{
+      pConfig->zContentRowid = sqlite3Fts5Strndup(&rc, zArg, -1);
+    }
+    return rc;
+  }
+
+  if( sqlite3_strnicmp("columnsize", zCmd, nCmd)==0 ){
+    if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1]!='\0' ){
+      *pzErr = sqlite3_mprintf("malformed columnsize=... directive");
+      rc = SQLITE_ERROR;
+    }else{
+      pConfig->bColumnsize = (zArg[0]=='1');
+    }
+    return rc;
+  }
+
+  if( sqlite3_strnicmp("detail", zCmd, nCmd)==0 ){
+    const Fts5Enum aDetail[] = {
+      { "none", FTS5_DETAIL_NONE },
+      { "full", FTS5_DETAIL_FULL },
+      { "columns", FTS5_DETAIL_COLUMNS },
+      { 0, 0 }
+    };
+
+    if( (rc = fts5ConfigSetEnum(aDetail, zArg, &pConfig->eDetail)) ){
+      *pzErr = sqlite3_mprintf("malformed detail=... directive");
+    }
+    return rc;
+  }
+
+  *pzErr = sqlite3_mprintf("unrecognized option: \"%.*s\"", nCmd, zCmd);
+  return SQLITE_ERROR;
+}
+
+/*
+** Allocate an instance of the default tokenizer ("simple") at 
+** Fts5Config.pTokenizer. Return SQLITE_OK if successful, or an SQLite error
+** code if an error occurs.
+*/
+static int fts5ConfigDefaultTokenizer(Fts5Global *pGlobal, Fts5Config *pConfig){
+  assert( pConfig->pTok==0 && pConfig->pTokApi==0 );
+  return sqlite3Fts5GetTokenizer(
+      pGlobal, 0, 0, &pConfig->pTok, &pConfig->pTokApi, 0
+  );
+}
+
+/*
+** Gobble up the first bareword or quoted word from the input buffer zIn.
+** Return a pointer to the character immediately following the last in
+** the gobbled word if successful, or a NULL pointer otherwise (failed
+** to find close-quote character).
+**
+** Before returning, set pzOut to point to a new buffer containing a
+** nul-terminated, dequoted copy of the gobbled word. If the word was
+** quoted, *pbQuoted is also set to 1 before returning.
+**
+** If *pRc is other than SQLITE_OK when this function is called, it is
+** a no-op (NULL is returned). Otherwise, if an OOM occurs within this
+** function, *pRc is set to SQLITE_NOMEM before returning. *pRc is *not*
+** set if a parse error (failed to find close quote) occurs.
+*/
+static const char *fts5ConfigGobbleWord(
+  int *pRc,                       /* IN/OUT: Error code */
+  const char *zIn,                /* Buffer to gobble string/bareword from */
+  char **pzOut,                   /* OUT: malloc'd buffer containing str/bw */
+  int *pbQuoted                   /* OUT: Set to true if dequoting required */
+){
+  const char *zRet = 0;
+
+  int nIn = (int)strlen(zIn);
+  char *zOut = sqlite3_malloc(nIn+1);
+
+  assert( *pRc==SQLITE_OK );
+  *pbQuoted = 0;
+  *pzOut = 0;
+
+  if( zOut==0 ){
+    *pRc = SQLITE_NOMEM;
+  }else{
+    memcpy(zOut, zIn, nIn+1);
+    if( fts5_isopenquote(zOut[0]) ){
+      int ii = fts5Dequote(zOut);
+      zRet = &zIn[ii];
+      *pbQuoted = 1;
+    }else{
+      zRet = fts5ConfigSkipBareword(zIn);
+      if( zRet ){
+        zOut[zRet-zIn] = '\0';
+      }
+    }
+  }
+
+  if( zRet==0 ){
+    sqlite3_free(zOut);
+  }else{
+    *pzOut = zOut;
+  }
+
+  return zRet;
+}
+
+static int fts5ConfigParseColumn(
+  Fts5Config *p, 
+  char *zCol, 
+  char *zArg, 
+  char **pzErr
+){
+  int rc = SQLITE_OK;
+  if( 0==sqlite3_stricmp(zCol, FTS5_RANK_NAME) 
+   || 0==sqlite3_stricmp(zCol, FTS5_ROWID_NAME) 
+  ){
+    *pzErr = sqlite3_mprintf("reserved fts5 column name: %s", zCol);
+    rc = SQLITE_ERROR;
+  }else if( zArg ){
+    if( 0==sqlite3_stricmp(zArg, "unindexed") ){
+      p->abUnindexed[p->nCol] = 1;
+    }else{
+      *pzErr = sqlite3_mprintf("unrecognized column option: %s", zArg);
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  p->azCol[p->nCol++] = zCol;
+  return rc;
+}
+
+/*
+** Populate the Fts5Config.zContentExprlist string.
+*/
+static int fts5ConfigMakeExprlist(Fts5Config *p){
+  int i;
+  int rc = SQLITE_OK;
+  Fts5Buffer buf = {0, 0, 0};
+
+  sqlite3Fts5BufferAppendPrintf(&rc, &buf, "T.%Q", p->zContentRowid);
+  if( p->eContent!=FTS5_CONTENT_NONE ){
+    for(i=0; i<p->nCol; i++){
+      if( p->eContent==FTS5_CONTENT_EXTERNAL ){
+        sqlite3Fts5BufferAppendPrintf(&rc, &buf, ", T.%Q", p->azCol[i]);
+      }else{
+        sqlite3Fts5BufferAppendPrintf(&rc, &buf, ", T.c%d", i);
+      }
+    }
+  }
+
+  assert( p->zContentExprlist==0 );
+  p->zContentExprlist = (char*)buf.p;
+  return rc;
+}
+
+/*
+** Arguments nArg/azArg contain the string arguments passed to the xCreate
+** or xConnect method of the virtual table. This function attempts to 
+** allocate an instance of Fts5Config containing the results of parsing
+** those arguments.
+**
+** If successful, SQLITE_OK is returned and *ppOut is set to point to the
+** new Fts5Config object. If an error occurs, an SQLite error code is 
+** returned, *ppOut is set to NULL and an error message may be left in
+** *pzErr. It is the responsibility of the caller to eventually free any 
+** such error message using sqlite3_free().
+*/
+static int sqlite3Fts5ConfigParse(
+  Fts5Global *pGlobal,
+  sqlite3 *db,
+  int nArg,                       /* Number of arguments */
+  const char **azArg,             /* Array of nArg CREATE VIRTUAL TABLE args */
+  Fts5Config **ppOut,             /* OUT: Results of parse */
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5Config *pRet;               /* New object to return */
+  int i;
+  int nByte;
+
+  *ppOut = pRet = (Fts5Config*)sqlite3_malloc(sizeof(Fts5Config));
+  if( pRet==0 ) return SQLITE_NOMEM;
+  memset(pRet, 0, sizeof(Fts5Config));
+  pRet->db = db;
+  pRet->iCookie = -1;
+
+  nByte = nArg * (sizeof(char*) + sizeof(u8));
+  pRet->azCol = (char**)sqlite3Fts5MallocZero(&rc, nByte);
+  pRet->abUnindexed = (u8*)&pRet->azCol[nArg];
+  pRet->zDb = sqlite3Fts5Strndup(&rc, azArg[1], -1);
+  pRet->zName = sqlite3Fts5Strndup(&rc, azArg[2], -1);
+  pRet->bColumnsize = 1;
+  pRet->eDetail = FTS5_DETAIL_FULL;
+#ifdef SQLITE_DEBUG
+  pRet->bPrefixIndex = 1;
+#endif
+  if( rc==SQLITE_OK && sqlite3_stricmp(pRet->zName, FTS5_RANK_NAME)==0 ){
+    *pzErr = sqlite3_mprintf("reserved fts5 table name: %s", pRet->zName);
+    rc = SQLITE_ERROR;
+  }
+
+  for(i=3; rc==SQLITE_OK && i<nArg; i++){
+    const char *zOrig = azArg[i];
+    const char *z;
+    char *zOne = 0;
+    char *zTwo = 0;
+    int bOption = 0;
+    int bMustBeCol = 0;
+
+    z = fts5ConfigGobbleWord(&rc, zOrig, &zOne, &bMustBeCol);
+    z = fts5ConfigSkipWhitespace(z);
+    if( z && *z=='=' ){
+      bOption = 1;
+      z++;
+      if( bMustBeCol ) z = 0;
+    }
+    z = fts5ConfigSkipWhitespace(z);
+    if( z && z[0] ){
+      int bDummy;
+      z = fts5ConfigGobbleWord(&rc, z, &zTwo, &bDummy);
+      if( z && z[0] ) z = 0;
+    }
+
+    if( rc==SQLITE_OK ){
+      if( z==0 ){
+        *pzErr = sqlite3_mprintf("parse error in \"%s\"", zOrig);
+        rc = SQLITE_ERROR;
+      }else{
+        if( bOption ){
+          rc = fts5ConfigParseSpecial(pGlobal, pRet, zOne, zTwo?zTwo:"", pzErr);
+        }else{
+          rc = fts5ConfigParseColumn(pRet, zOne, zTwo, pzErr);
+          zOne = 0;
+        }
+      }
+    }
+
+    sqlite3_free(zOne);
+    sqlite3_free(zTwo);
+  }
+
+  /* If a tokenizer= option was successfully parsed, the tokenizer has
+  ** already been allocated. Otherwise, allocate an instance of the default
+  ** tokenizer (unicode61) now.  */
+  if( rc==SQLITE_OK && pRet->pTok==0 ){
+    rc = fts5ConfigDefaultTokenizer(pGlobal, pRet);
+  }
+
+  /* If no zContent option was specified, fill in the default values. */
+  if( rc==SQLITE_OK && pRet->zContent==0 ){
+    const char *zTail = 0;
+    assert( pRet->eContent==FTS5_CONTENT_NORMAL 
+         || pRet->eContent==FTS5_CONTENT_NONE 
+    );
+    if( pRet->eContent==FTS5_CONTENT_NORMAL ){
+      zTail = "content";
+    }else if( pRet->bColumnsize ){
+      zTail = "docsize";
+    }
+
+    if( zTail ){
+      pRet->zContent = sqlite3Fts5Mprintf(
+          &rc, "%Q.'%q_%s'", pRet->zDb, pRet->zName, zTail
+      );
+    }
+  }
+
+  if( rc==SQLITE_OK && pRet->zContentRowid==0 ){
+    pRet->zContentRowid = sqlite3Fts5Strndup(&rc, "rowid", -1);
+  }
+
+  /* Formulate the zContentExprlist text */
+  if( rc==SQLITE_OK ){
+    rc = fts5ConfigMakeExprlist(pRet);
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3Fts5ConfigFree(pRet);
+    *ppOut = 0;
+  }
+  return rc;
+}
+
+/*
+** Free the configuration object passed as the only argument.
+*/
+static void sqlite3Fts5ConfigFree(Fts5Config *pConfig){
+  if( pConfig ){
+    int i;
+    if( pConfig->pTok ){
+      pConfig->pTokApi->xDelete(pConfig->pTok);
+    }
+    sqlite3_free(pConfig->zDb);
+    sqlite3_free(pConfig->zName);
+    for(i=0; i<pConfig->nCol; i++){
+      sqlite3_free(pConfig->azCol[i]);
+    }
+    sqlite3_free(pConfig->azCol);
+    sqlite3_free(pConfig->aPrefix);
+    sqlite3_free(pConfig->zRank);
+    sqlite3_free(pConfig->zRankArgs);
+    sqlite3_free(pConfig->zContent);
+    sqlite3_free(pConfig->zContentRowid);
+    sqlite3_free(pConfig->zContentExprlist);
+    sqlite3_free(pConfig);
+  }
+}
+
+/*
+** Call sqlite3_declare_vtab() based on the contents of the configuration
+** object passed as the only argument. Return SQLITE_OK if successful, or
+** an SQLite error code if an error occurs.
+*/
+static int sqlite3Fts5ConfigDeclareVtab(Fts5Config *pConfig){
+  int i;
+  int rc = SQLITE_OK;
+  char *zSql;
+
+  zSql = sqlite3Fts5Mprintf(&rc, "CREATE TABLE x(");
+  for(i=0; zSql && i<pConfig->nCol; i++){
+    const char *zSep = (i==0?"":", ");
+    zSql = sqlite3Fts5Mprintf(&rc, "%z%s%Q", zSql, zSep, pConfig->azCol[i]);
+  }
+  zSql = sqlite3Fts5Mprintf(&rc, "%z, %Q HIDDEN, %s HIDDEN)", 
+      zSql, pConfig->zName, FTS5_RANK_NAME
+  );
+
+  assert( zSql || rc==SQLITE_NOMEM );
+  if( zSql ){
+    rc = sqlite3_declare_vtab(pConfig->db, zSql);
+    sqlite3_free(zSql);
+  }
+  
+  return rc;
+}
+
+/*
+** Tokenize the text passed via the second and third arguments.
+**
+** The callback is invoked once for each token in the input text. The
+** arguments passed to it are, in order:
+**
+**     void *pCtx          // Copy of 4th argument to sqlite3Fts5Tokenize()
+**     const char *pToken  // Pointer to buffer containing token
+**     int nToken          // Size of token in bytes
+**     int iStart          // Byte offset of start of token within input text
+**     int iEnd            // Byte offset of end of token within input text
+**     int iPos            // Position of token in input (first token is 0)
+**
+** If the callback returns a non-zero value the tokenization is abandoned
+** and no further callbacks are issued. 
+**
+** This function returns SQLITE_OK if successful or an SQLite error code
+** if an error occurs. If the tokenization was abandoned early because
+** the callback returned SQLITE_DONE, this is not an error and this function
+** still returns SQLITE_OK. Or, if the tokenization was abandoned early
+** because the callback returned another non-zero value, it is assumed
+** to be an SQLite error code and returned to the caller.
+*/
+static int sqlite3Fts5Tokenize(
+  Fts5Config *pConfig,            /* FTS5 Configuration object */
+  int flags,                      /* FTS5_TOKENIZE_* flags */
+  const char *pText, int nText,   /* Text to tokenize */
+  void *pCtx,                     /* Context passed to xToken() */
+  int (*xToken)(void*, int, const char*, int, int, int)    /* Callback */
+){
+  if( pText==0 ) return SQLITE_OK;
+  return pConfig->pTokApi->xTokenize(
+      pConfig->pTok, pCtx, flags, pText, nText, xToken
+  );
+}
+
+/*
+** Argument pIn points to the first character in what is expected to be
+** a comma-separated list of SQL literals followed by a ')' character.
+** If it actually is this, return a pointer to the ')'. Otherwise, return
+** NULL to indicate a parse error.
+*/
+static const char *fts5ConfigSkipArgs(const char *pIn){
+  const char *p = pIn;
+  
+  while( 1 ){
+    p = fts5ConfigSkipWhitespace(p);
+    p = fts5ConfigSkipLiteral(p);
+    p = fts5ConfigSkipWhitespace(p);
+    if( p==0 || *p==')' ) break;
+    if( *p!=',' ){
+      p = 0;
+      break;
+    }
+    p++;
+  }
+
+  return p;
+}
+
+/*
+** Parameter zIn contains a rank() function specification. The format of 
+** this is:
+**
+**   + Bareword (function name)
+**   + Open parenthesis - "("
+**   + Zero or more SQL literals in a comma separated list
+**   + Close parenthesis - ")"
+*/
+static int sqlite3Fts5ConfigParseRank(
+  const char *zIn,                /* Input string */
+  char **pzRank,                  /* OUT: Rank function name */
+  char **pzRankArgs               /* OUT: Rank function arguments */
+){
+  const char *p = zIn;
+  const char *pRank;
+  char *zRank = 0;
+  char *zRankArgs = 0;
+  int rc = SQLITE_OK;
+
+  *pzRank = 0;
+  *pzRankArgs = 0;
+
+  if( p==0 ){
+    rc = SQLITE_ERROR;
+  }else{
+    p = fts5ConfigSkipWhitespace(p);
+    pRank = p;
+    p = fts5ConfigSkipBareword(p);
+
+    if( p ){
+      zRank = sqlite3Fts5MallocZero(&rc, 1 + p - pRank);
+      if( zRank ) memcpy(zRank, pRank, p-pRank);
+    }else{
+      rc = SQLITE_ERROR;
+    }
+
+    if( rc==SQLITE_OK ){
+      p = fts5ConfigSkipWhitespace(p);
+      if( *p!='(' ) rc = SQLITE_ERROR;
+      p++;
+    }
+    if( rc==SQLITE_OK ){
+      const char *pArgs; 
+      p = fts5ConfigSkipWhitespace(p);
+      pArgs = p;
+      if( *p!=')' ){
+        p = fts5ConfigSkipArgs(p);
+        if( p==0 ){
+          rc = SQLITE_ERROR;
+        }else{
+          zRankArgs = sqlite3Fts5MallocZero(&rc, 1 + p - pArgs);
+          if( zRankArgs ) memcpy(zRankArgs, pArgs, p-pArgs);
+        }
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(zRank);
+    assert( zRankArgs==0 );
+  }else{
+    *pzRank = zRank;
+    *pzRankArgs = zRankArgs;
+  }
+  return rc;
+}
+
+static int sqlite3Fts5ConfigSetValue(
+  Fts5Config *pConfig, 
+  const char *zKey, 
+  sqlite3_value *pVal,
+  int *pbBadkey
+){
+  int rc = SQLITE_OK;
+
+  if( 0==sqlite3_stricmp(zKey, "pgsz") ){
+    int pgsz = 0;
+    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
+      pgsz = sqlite3_value_int(pVal);
+    }
+    if( pgsz<=0 || pgsz>FTS5_MAX_PAGE_SIZE ){
+      *pbBadkey = 1;
+    }else{
+      pConfig->pgsz = pgsz;
+    }
+  }
+
+  else if( 0==sqlite3_stricmp(zKey, "hashsize") ){
+    int nHashSize = -1;
+    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
+      nHashSize = sqlite3_value_int(pVal);
+    }
+    if( nHashSize<=0 ){
+      *pbBadkey = 1;
+    }else{
+      pConfig->nHashSize = nHashSize;
+    }
+  }
+
+  else if( 0==sqlite3_stricmp(zKey, "automerge") ){
+    int nAutomerge = -1;
+    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
+      nAutomerge = sqlite3_value_int(pVal);
+    }
+    if( nAutomerge<0 || nAutomerge>64 ){
+      *pbBadkey = 1;
+    }else{
+      if( nAutomerge==1 ) nAutomerge = FTS5_DEFAULT_AUTOMERGE;
+      pConfig->nAutomerge = nAutomerge;
+    }
+  }
+
+  else if( 0==sqlite3_stricmp(zKey, "usermerge") ){
+    int nUsermerge = -1;
+    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
+      nUsermerge = sqlite3_value_int(pVal);
+    }
+    if( nUsermerge<2 || nUsermerge>16 ){
+      *pbBadkey = 1;
+    }else{
+      pConfig->nUsermerge = nUsermerge;
+    }
+  }
+
+  else if( 0==sqlite3_stricmp(zKey, "crisismerge") ){
+    int nCrisisMerge = -1;
+    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
+      nCrisisMerge = sqlite3_value_int(pVal);
+    }
+    if( nCrisisMerge<0 ){
+      *pbBadkey = 1;
+    }else{
+      if( nCrisisMerge<=1 ) nCrisisMerge = FTS5_DEFAULT_CRISISMERGE;
+      pConfig->nCrisisMerge = nCrisisMerge;
+    }
+  }
+
+  else if( 0==sqlite3_stricmp(zKey, "rank") ){
+    const char *zIn = (const char*)sqlite3_value_text(pVal);
+    char *zRank;
+    char *zRankArgs;
+    rc = sqlite3Fts5ConfigParseRank(zIn, &zRank, &zRankArgs);
+    if( rc==SQLITE_OK ){
+      sqlite3_free(pConfig->zRank);
+      sqlite3_free(pConfig->zRankArgs);
+      pConfig->zRank = zRank;
+      pConfig->zRankArgs = zRankArgs;
+    }else if( rc==SQLITE_ERROR ){
+      rc = SQLITE_OK;
+      *pbBadkey = 1;
+    }
+  }else{
+    *pbBadkey = 1;
+  }
+  return rc;
+}
+
+/*
+** Load the contents of the %_config table into memory.
+*/
+static int sqlite3Fts5ConfigLoad(Fts5Config *pConfig, int iCookie){
+  const char *zSelect = "SELECT k, v FROM %Q.'%q_config'";
+  char *zSql;
+  sqlite3_stmt *p = 0;
+  int rc = SQLITE_OK;
+  int iVersion = 0;
+
+  /* Set default values */
+  pConfig->pgsz = FTS5_DEFAULT_PAGE_SIZE;
+  pConfig->nAutomerge = FTS5_DEFAULT_AUTOMERGE;
+  pConfig->nUsermerge = FTS5_DEFAULT_USERMERGE;
+  pConfig->nCrisisMerge = FTS5_DEFAULT_CRISISMERGE;
+  pConfig->nHashSize = FTS5_DEFAULT_HASHSIZE;
+
+  zSql = sqlite3Fts5Mprintf(&rc, zSelect, pConfig->zDb, pConfig->zName);
+  if( zSql ){
+    rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &p, 0);
+    sqlite3_free(zSql);
+  }
+
+  assert( rc==SQLITE_OK || p==0 );
+  if( rc==SQLITE_OK ){
+    while( SQLITE_ROW==sqlite3_step(p) ){
+      const char *zK = (const char*)sqlite3_column_text(p, 0);
+      sqlite3_value *pVal = sqlite3_column_value(p, 1);
+      if( 0==sqlite3_stricmp(zK, "version") ){
+        iVersion = sqlite3_value_int(pVal);
+      }else{
+        int bDummy = 0;
+        sqlite3Fts5ConfigSetValue(pConfig, zK, pVal, &bDummy);
+      }
+    }
+    rc = sqlite3_finalize(p);
+  }
+  
+  if( rc==SQLITE_OK && iVersion!=FTS5_CURRENT_VERSION ){
+    rc = SQLITE_ERROR;
+    if( pConfig->pzErrmsg ){
+      assert( 0==*pConfig->pzErrmsg );
+      *pConfig->pzErrmsg = sqlite3_mprintf(
+          "invalid fts5 file format (found %d, expected %d) - run 'rebuild'",
+          iVersion, FTS5_CURRENT_VERSION
+      );
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    pConfig->iCookie = iCookie;
+  }
+  return rc;
+}
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+
+
+
+/* #include "fts5Int.h" */
+/* #include "fts5parse.h" */
+
+/*
+** All token types in the generated fts5parse.h file are greater than 0.
+*/
+#define FTS5_EOF 0
+
+#define FTS5_LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
+
+typedef struct Fts5ExprTerm Fts5ExprTerm;
+
+/*
+** Functions generated by lemon from fts5parse.y.
+*/
+static void *sqlite3Fts5ParserAlloc(void *(*mallocProc)(u64));
+static void sqlite3Fts5ParserFree(void*, void (*freeProc)(void*));
+static void sqlite3Fts5Parser(void*, int, Fts5Token, Fts5Parse*);
+#ifndef NDEBUG
+/* #include <stdio.h> */
+static void sqlite3Fts5ParserTrace(FILE*, char*);
+#endif
+
+
+struct Fts5Expr {
+  Fts5Index *pIndex;
+  Fts5Config *pConfig;
+  Fts5ExprNode *pRoot;
+  int bDesc;                      /* Iterate in descending rowid order */
+  int nPhrase;                    /* Number of phrases in expression */
+  Fts5ExprPhrase **apExprPhrase;  /* Pointers to phrase objects */
+};
+
+/*
+** eType:
+**   Expression node type. Always one of:
+**
+**       FTS5_AND                 (nChild, apChild valid)
+**       FTS5_OR                  (nChild, apChild valid)
+**       FTS5_NOT                 (nChild, apChild valid)
+**       FTS5_STRING              (pNear valid)
+**       FTS5_TERM                (pNear valid)
+*/
+struct Fts5ExprNode {
+  int eType;                      /* Node type */
+  int bEof;                       /* True at EOF */
+  int bNomatch;                   /* True if entry is not a match */
+
+  /* Next method for this node. */
+  int (*xNext)(Fts5Expr*, Fts5ExprNode*, int, i64);
+
+  i64 iRowid;                     /* Current rowid */
+  Fts5ExprNearset *pNear;         /* For FTS5_STRING - cluster of phrases */
+
+  /* Child nodes. For a NOT node, this array always contains 2 entries. For 
+  ** AND or OR nodes, it contains 2 or more entries.  */
+  int nChild;                     /* Number of child nodes */
+  Fts5ExprNode *apChild[1];       /* Array of child nodes */
+};
+
+#define Fts5NodeIsString(p) ((p)->eType==FTS5_TERM || (p)->eType==FTS5_STRING)
+
+/*
+** Invoke the xNext method of an Fts5ExprNode object. This macro should be
+** used as if it has the same signature as the xNext() methods themselves.
+*/
+#define fts5ExprNodeNext(a,b,c,d) (b)->xNext((a), (b), (c), (d))
+
+/*
+** An instance of the following structure represents a single search term
+** or term prefix.
+*/
+struct Fts5ExprTerm {
+  int bPrefix;                    /* True for a prefix term */
+  char *zTerm;                    /* nul-terminated term */
+  Fts5IndexIter *pIter;           /* Iterator for this term */
+  Fts5ExprTerm *pSynonym;         /* Pointer to first in list of synonyms */
+};
+
+/*
+** A phrase. One or more terms that must appear in a contiguous sequence
+** within a document for it to match.
+*/
+struct Fts5ExprPhrase {
+  Fts5ExprNode *pNode;            /* FTS5_STRING node this phrase is part of */
+  Fts5Buffer poslist;             /* Current position list */
+  int nTerm;                      /* Number of entries in aTerm[] */
+  Fts5ExprTerm aTerm[1];          /* Terms that make up this phrase */
+};
+
+/*
+** One or more phrases that must appear within a certain token distance of
+** each other within each matching document.
+*/
+struct Fts5ExprNearset {
+  int nNear;                      /* NEAR parameter */
+  Fts5Colset *pColset;            /* Columns to search (NULL -> all columns) */
+  int nPhrase;                    /* Number of entries in aPhrase[] array */
+  Fts5ExprPhrase *apPhrase[1];    /* Array of phrase pointers */
+};
+
+
+/*
+** Parse context.
+*/
+struct Fts5Parse {
+  Fts5Config *pConfig;
+  char *zErr;
+  int rc;
+  int nPhrase;                    /* Size of apPhrase array */
+  Fts5ExprPhrase **apPhrase;      /* Array of all phrases */
+  Fts5ExprNode *pExpr;            /* Result of a successful parse */
+};
+
+static void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...){
+  va_list ap;
+  va_start(ap, zFmt);
+  if( pParse->rc==SQLITE_OK ){
+    pParse->zErr = sqlite3_vmprintf(zFmt, ap);
+    pParse->rc = SQLITE_ERROR;
+  }
+  va_end(ap);
+}
+
+static int fts5ExprIsspace(char t){
+  return t==' ' || t=='\t' || t=='\n' || t=='\r';
+}
+
+/*
+** Read the first token from the nul-terminated string at *pz.
+*/
+static int fts5ExprGetToken(
+  Fts5Parse *pParse, 
+  const char **pz,                /* IN/OUT: Pointer into buffer */
+  Fts5Token *pToken
+){
+  const char *z = *pz;
+  int tok;
+
+  /* Skip past any whitespace */
+  while( fts5ExprIsspace(*z) ) z++;
+
+  pToken->p = z;
+  pToken->n = 1;
+  switch( *z ){
+    case '(':  tok = FTS5_LP;    break;
+    case ')':  tok = FTS5_RP;    break;
+    case '{':  tok = FTS5_LCP;   break;
+    case '}':  tok = FTS5_RCP;   break;
+    case ':':  tok = FTS5_COLON; break;
+    case ',':  tok = FTS5_COMMA; break;
+    case '+':  tok = FTS5_PLUS;  break;
+    case '*':  tok = FTS5_STAR;  break;
+    case '\0': tok = FTS5_EOF;   break;
+
+    case '"': {
+      const char *z2;
+      tok = FTS5_STRING;
+
+      for(z2=&z[1]; 1; z2++){
+        if( z2[0]=='"' ){
+          z2++;
+          if( z2[0]!='"' ) break;
+        }
+        if( z2[0]=='\0' ){
+          sqlite3Fts5ParseError(pParse, "unterminated string");
+          return FTS5_EOF;
+        }
+      }
+      pToken->n = (z2 - z);
+      break;
+    }
+
+    default: {
+      const char *z2;
+      if( sqlite3Fts5IsBareword(z[0])==0 ){
+        sqlite3Fts5ParseError(pParse, "fts5: syntax error near \"%.1s\"", z);
+        return FTS5_EOF;
+      }
+      tok = FTS5_STRING;
+      for(z2=&z[1]; sqlite3Fts5IsBareword(*z2); z2++);
+      pToken->n = (z2 - z);
+      if( pToken->n==2 && memcmp(pToken->p, "OR", 2)==0 )  tok = FTS5_OR;
+      if( pToken->n==3 && memcmp(pToken->p, "NOT", 3)==0 ) tok = FTS5_NOT;
+      if( pToken->n==3 && memcmp(pToken->p, "AND", 3)==0 ) tok = FTS5_AND;
+      break;
+    }
+  }
+
+  *pz = &pToken->p[pToken->n];
+  return tok;
+}
+
+static void *fts5ParseAlloc(u64 t){ return sqlite3_malloc((int)t); }
+static void fts5ParseFree(void *p){ sqlite3_free(p); }
+
+static int sqlite3Fts5ExprNew(
+  Fts5Config *pConfig,            /* FTS5 Configuration */
+  const char *zExpr,              /* Expression text */
+  Fts5Expr **ppNew, 
+  char **pzErr
+){
+  Fts5Parse sParse;
+  Fts5Token token;
+  const char *z = zExpr;
+  int t;                          /* Next token type */
+  void *pEngine;
+  Fts5Expr *pNew;
+
+  *ppNew = 0;
+  *pzErr = 0;
+  memset(&sParse, 0, sizeof(sParse));
+  pEngine = sqlite3Fts5ParserAlloc(fts5ParseAlloc);
+  if( pEngine==0 ){ return SQLITE_NOMEM; }
+  sParse.pConfig = pConfig;
+
+  do {
+    t = fts5ExprGetToken(&sParse, &z, &token);
+    sqlite3Fts5Parser(pEngine, t, token, &sParse);
+  }while( sParse.rc==SQLITE_OK && t!=FTS5_EOF );
+  sqlite3Fts5ParserFree(pEngine, fts5ParseFree);
+
+  assert( sParse.rc!=SQLITE_OK || sParse.zErr==0 );
+  if( sParse.rc==SQLITE_OK ){
+    *ppNew = pNew = sqlite3_malloc(sizeof(Fts5Expr));
+    if( pNew==0 ){
+      sParse.rc = SQLITE_NOMEM;
+      sqlite3Fts5ParseNodeFree(sParse.pExpr);
+    }else{
+      if( !sParse.pExpr ){
+        const int nByte = sizeof(Fts5ExprNode);
+        pNew->pRoot = (Fts5ExprNode*)sqlite3Fts5MallocZero(&sParse.rc, nByte);
+        if( pNew->pRoot ){
+          pNew->pRoot->bEof = 1;
+        }
+      }else{
+        pNew->pRoot = sParse.pExpr;
+      }
+      pNew->pIndex = 0;
+      pNew->pConfig = pConfig;
+      pNew->apExprPhrase = sParse.apPhrase;
+      pNew->nPhrase = sParse.nPhrase;
+      sParse.apPhrase = 0;
+    }
+  }else{
+    sqlite3Fts5ParseNodeFree(sParse.pExpr);
+  }
+
+  sqlite3_free(sParse.apPhrase);
+  *pzErr = sParse.zErr;
+  return sParse.rc;
+}
+
+/*
+** Free the expression node object passed as the only argument.
+*/
+static void sqlite3Fts5ParseNodeFree(Fts5ExprNode *p){
+  if( p ){
+    int i;
+    for(i=0; i<p->nChild; i++){
+      sqlite3Fts5ParseNodeFree(p->apChild[i]);
+    }
+    sqlite3Fts5ParseNearsetFree(p->pNear);
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Free the expression object passed as the only argument.
+*/
+static void sqlite3Fts5ExprFree(Fts5Expr *p){
+  if( p ){
+    sqlite3Fts5ParseNodeFree(p->pRoot);
+    sqlite3_free(p->apExprPhrase);
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Argument pTerm must be a synonym iterator. Return the current rowid
+** that it points to.
+*/
+static i64 fts5ExprSynonymRowid(Fts5ExprTerm *pTerm, int bDesc, int *pbEof){
+  i64 iRet = 0;
+  int bRetValid = 0;
+  Fts5ExprTerm *p;
+
+  assert( pTerm->pSynonym );
+  assert( bDesc==0 || bDesc==1 );
+  for(p=pTerm; p; p=p->pSynonym){
+    if( 0==sqlite3Fts5IterEof(p->pIter) ){
+      i64 iRowid = p->pIter->iRowid;
+      if( bRetValid==0 || (bDesc!=(iRowid<iRet)) ){
+        iRet = iRowid;
+        bRetValid = 1;
+      }
+    }
+  }
+
+  if( pbEof && bRetValid==0 ) *pbEof = 1;
+  return iRet;
+}
+
+/*
+** Argument pTerm must be a synonym iterator.
+*/
+static int fts5ExprSynonymList(
+  Fts5ExprTerm *pTerm, 
+  i64 iRowid,
+  Fts5Buffer *pBuf,               /* Use this buffer for space if required */
+  u8 **pa, int *pn
+){
+  Fts5PoslistReader aStatic[4];
+  Fts5PoslistReader *aIter = aStatic;
+  int nIter = 0;
+  int nAlloc = 4;
+  int rc = SQLITE_OK;
+  Fts5ExprTerm *p;
+
+  assert( pTerm->pSynonym );
+  for(p=pTerm; p; p=p->pSynonym){
+    Fts5IndexIter *pIter = p->pIter;
+    if( sqlite3Fts5IterEof(pIter)==0 && pIter->iRowid==iRowid ){
+      if( pIter->nData==0 ) continue;
+      if( nIter==nAlloc ){
+        int nByte = sizeof(Fts5PoslistReader) * nAlloc * 2;
+        Fts5PoslistReader *aNew = (Fts5PoslistReader*)sqlite3_malloc(nByte);
+        if( aNew==0 ){
+          rc = SQLITE_NOMEM;
+          goto synonym_poslist_out;
+        }
+        memcpy(aNew, aIter, sizeof(Fts5PoslistReader) * nIter);
+        nAlloc = nAlloc*2;
+        if( aIter!=aStatic ) sqlite3_free(aIter);
+        aIter = aNew;
+      }
+      sqlite3Fts5PoslistReaderInit(pIter->pData, pIter->nData, &aIter[nIter]);
+      assert( aIter[nIter].bEof==0 );
+      nIter++;
+    }
+  }
+
+  if( nIter==1 ){
+    *pa = (u8*)aIter[0].a;
+    *pn = aIter[0].n;
+  }else{
+    Fts5PoslistWriter writer = {0};
+    i64 iPrev = -1;
+    fts5BufferZero(pBuf);
+    while( 1 ){
+      int i;
+      i64 iMin = FTS5_LARGEST_INT64;
+      for(i=0; i<nIter; i++){
+        if( aIter[i].bEof==0 ){
+          if( aIter[i].iPos==iPrev ){
+            if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) continue;
+          }
+          if( aIter[i].iPos<iMin ){
+            iMin = aIter[i].iPos;
+          }
+        }
+      }
+      if( iMin==FTS5_LARGEST_INT64 || rc!=SQLITE_OK ) break;
+      rc = sqlite3Fts5PoslistWriterAppend(pBuf, &writer, iMin);
+      iPrev = iMin;
+    }
+    if( rc==SQLITE_OK ){
+      *pa = pBuf->p;
+      *pn = pBuf->n;
+    }
+  }
+
+ synonym_poslist_out:
+  if( aIter!=aStatic ) sqlite3_free(aIter);
+  return rc;
+}
+
+
+/*
+** All individual term iterators in pPhrase are guaranteed to be valid and
+** pointing to the same rowid when this function is called. This function 
+** checks if the current rowid really is a match, and if so populates
+** the pPhrase->poslist buffer accordingly. Output parameter *pbMatch
+** is set to true if this is really a match, or false otherwise.
+**
+** SQLITE_OK is returned if an error occurs, or an SQLite error code 
+** otherwise. It is not considered an error code if the current rowid is 
+** not a match.
+*/
+static int fts5ExprPhraseIsMatch(
+  Fts5ExprNode *pNode,            /* Node pPhrase belongs to */
+  Fts5ExprPhrase *pPhrase,        /* Phrase object to initialize */
+  int *pbMatch                    /* OUT: Set to true if really a match */
+){
+  Fts5PoslistWriter writer = {0};
+  Fts5PoslistReader aStatic[4];
+  Fts5PoslistReader *aIter = aStatic;
+  int i;
+  int rc = SQLITE_OK;
+  
+  fts5BufferZero(&pPhrase->poslist);
+
+  /* If the aStatic[] array is not large enough, allocate a large array
+  ** using sqlite3_malloc(). This approach could be improved upon. */
+  if( pPhrase->nTerm>ArraySize(aStatic) ){
+    int nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;
+    aIter = (Fts5PoslistReader*)sqlite3_malloc(nByte);
+    if( !aIter ) return SQLITE_NOMEM;
+  }
+  memset(aIter, 0, sizeof(Fts5PoslistReader) * pPhrase->nTerm);
+
+  /* Initialize a term iterator for each term in the phrase */
+  for(i=0; i<pPhrase->nTerm; i++){
+    Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];
+    int n = 0;
+    int bFlag = 0;
+    u8 *a = 0;
+    if( pTerm->pSynonym ){
+      Fts5Buffer buf = {0, 0, 0};
+      rc = fts5ExprSynonymList(pTerm, pNode->iRowid, &buf, &a, &n);
+      if( rc ){
+        sqlite3_free(a);
+        goto ismatch_out;
+      }
+      if( a==buf.p ) bFlag = 1;
+    }else{
+      a = (u8*)pTerm->pIter->pData;
+      n = pTerm->pIter->nData;
+    }
+    sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);
+    aIter[i].bFlag = (u8)bFlag;
+    if( aIter[i].bEof ) goto ismatch_out;
+  }
+
+  while( 1 ){
+    int bMatch;
+    i64 iPos = aIter[0].iPos;
+    do {
+      bMatch = 1;
+      for(i=0; i<pPhrase->nTerm; i++){
+        Fts5PoslistReader *pPos = &aIter[i];
+        i64 iAdj = iPos + i;
+        if( pPos->iPos!=iAdj ){
+          bMatch = 0;
+          while( pPos->iPos<iAdj ){
+            if( sqlite3Fts5PoslistReaderNext(pPos) ) goto ismatch_out;
+          }
+          if( pPos->iPos>iAdj ) iPos = pPos->iPos-i;
+        }
+      }
+    }while( bMatch==0 );
+
+    /* Append position iPos to the output */
+    rc = sqlite3Fts5PoslistWriterAppend(&pPhrase->poslist, &writer, iPos);
+    if( rc!=SQLITE_OK ) goto ismatch_out;
+
+    for(i=0; i<pPhrase->nTerm; i++){
+      if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) goto ismatch_out;
+    }
+  }
+
+ ismatch_out:
+  *pbMatch = (pPhrase->poslist.n>0);
+  for(i=0; i<pPhrase->nTerm; i++){
+    if( aIter[i].bFlag ) sqlite3_free((u8*)aIter[i].a);
+  }
+  if( aIter!=aStatic ) sqlite3_free(aIter);
+  return rc;
+}
+
+typedef struct Fts5LookaheadReader Fts5LookaheadReader;
+struct Fts5LookaheadReader {
+  const u8 *a;                    /* Buffer containing position list */
+  int n;                          /* Size of buffer a[] in bytes */
+  int i;                          /* Current offset in position list */
+  i64 iPos;                       /* Current position */
+  i64 iLookahead;                 /* Next position */
+};
+
+#define FTS5_LOOKAHEAD_EOF (((i64)1) << 62)
+
+static int fts5LookaheadReaderNext(Fts5LookaheadReader *p){
+  p->iPos = p->iLookahead;
+  if( sqlite3Fts5PoslistNext64(p->a, p->n, &p->i, &p->iLookahead) ){
+    p->iLookahead = FTS5_LOOKAHEAD_EOF;
+  }
+  return (p->iPos==FTS5_LOOKAHEAD_EOF);
+}
+
+static int fts5LookaheadReaderInit(
+  const u8 *a, int n,             /* Buffer to read position list from */
+  Fts5LookaheadReader *p          /* Iterator object to initialize */
+){
+  memset(p, 0, sizeof(Fts5LookaheadReader));
+  p->a = a;
+  p->n = n;
+  fts5LookaheadReaderNext(p);
+  return fts5LookaheadReaderNext(p);
+}
+
+typedef struct Fts5NearTrimmer Fts5NearTrimmer;
+struct Fts5NearTrimmer {
+  Fts5LookaheadReader reader;     /* Input iterator */
+  Fts5PoslistWriter writer;       /* Writer context */
+  Fts5Buffer *pOut;               /* Output poslist */
+};
+
+/*
+** The near-set object passed as the first argument contains more than
+** one phrase. All phrases currently point to the same row. The
+** Fts5ExprPhrase.poslist buffers are populated accordingly. This function
+** tests if the current row contains instances of each phrase sufficiently
+** close together to meet the NEAR constraint. Non-zero is returned if it
+** does, or zero otherwise.
+**
+** If in/out parameter (*pRc) is set to other than SQLITE_OK when this
+** function is called, it is a no-op. Or, if an error (e.g. SQLITE_NOMEM)
+** occurs within this function (*pRc) is set accordingly before returning.
+** The return value is undefined in both these cases.
+** 
+** If no error occurs and non-zero (a match) is returned, the position-list
+** of each phrase object is edited to contain only those entries that
+** meet the constraint before returning.
+*/
+static int fts5ExprNearIsMatch(int *pRc, Fts5ExprNearset *pNear){
+  Fts5NearTrimmer aStatic[4];
+  Fts5NearTrimmer *a = aStatic;
+  Fts5ExprPhrase **apPhrase = pNear->apPhrase;
+
+  int i;
+  int rc = *pRc;
+  int bMatch;
+
+  assert( pNear->nPhrase>1 );
+
+  /* If the aStatic[] array is not large enough, allocate a large array
+  ** using sqlite3_malloc(). This approach could be improved upon. */
+  if( pNear->nPhrase>ArraySize(aStatic) ){
+    int nByte = sizeof(Fts5NearTrimmer) * pNear->nPhrase;
+    a = (Fts5NearTrimmer*)sqlite3Fts5MallocZero(&rc, nByte);
+  }else{
+    memset(aStatic, 0, sizeof(aStatic));
+  }
+  if( rc!=SQLITE_OK ){
+    *pRc = rc;
+    return 0;
+  }
+
+  /* Initialize a lookahead iterator for each phrase. After passing the
+  ** buffer and buffer size to the lookaside-reader init function, zero
+  ** the phrase poslist buffer. The new poslist for the phrase (containing
+  ** the same entries as the original with some entries removed on account 
+  ** of the NEAR constraint) is written over the original even as it is
+  ** being read. This is safe as the entries for the new poslist are a
+  ** subset of the old, so it is not possible for data yet to be read to
+  ** be overwritten.  */
+  for(i=0; i<pNear->nPhrase; i++){
+    Fts5Buffer *pPoslist = &apPhrase[i]->poslist;
+    fts5LookaheadReaderInit(pPoslist->p, pPoslist->n, &a[i].reader);
+    pPoslist->n = 0;
+    a[i].pOut = pPoslist;
+  }
+
+  while( 1 ){
+    int iAdv;
+    i64 iMin;
+    i64 iMax;
+
+    /* This block advances the phrase iterators until they point to a set of
+    ** entries that together comprise a match.  */
+    iMax = a[0].reader.iPos;
+    do {
+      bMatch = 1;
+      for(i=0; i<pNear->nPhrase; i++){
+        Fts5LookaheadReader *pPos = &a[i].reader;
+        iMin = iMax - pNear->apPhrase[i]->nTerm - pNear->nNear;
+        if( pPos->iPos<iMin || pPos->iPos>iMax ){
+          bMatch = 0;
+          while( pPos->iPos<iMin ){
+            if( fts5LookaheadReaderNext(pPos) ) goto ismatch_out;
+          }
+          if( pPos->iPos>iMax ) iMax = pPos->iPos;
+        }
+      }
+    }while( bMatch==0 );
+
+    /* Add an entry to each output position list */
+    for(i=0; i<pNear->nPhrase; i++){
+      i64 iPos = a[i].reader.iPos;
+      Fts5PoslistWriter *pWriter = &a[i].writer;
+      if( a[i].pOut->n==0 || iPos!=pWriter->iPrev ){
+        sqlite3Fts5PoslistWriterAppend(a[i].pOut, pWriter, iPos);
+      }
+    }
+
+    iAdv = 0;
+    iMin = a[0].reader.iLookahead;
+    for(i=0; i<pNear->nPhrase; i++){
+      if( a[i].reader.iLookahead < iMin ){
+        iMin = a[i].reader.iLookahead;
+        iAdv = i;
+      }
+    }
+    if( fts5LookaheadReaderNext(&a[iAdv].reader) ) goto ismatch_out;
+  }
+
+  ismatch_out: {
+    int bRet = a[0].pOut->n>0;
+    *pRc = rc;
+    if( a!=aStatic ) sqlite3_free(a);
+    return bRet;
+  }
+}
+
+/*
+** Advance iterator pIter until it points to a value equal to or laster
+** than the initial value of *piLast. If this means the iterator points
+** to a value laster than *piLast, update *piLast to the new lastest value.
+**
+** If the iterator reaches EOF, set *pbEof to true before returning. If
+** an error occurs, set *pRc to an error code. If either *pbEof or *pRc
+** are set, return a non-zero value. Otherwise, return zero.
+*/
+static int fts5ExprAdvanceto(
+  Fts5IndexIter *pIter,           /* Iterator to advance */
+  int bDesc,                      /* True if iterator is "rowid DESC" */
+  i64 *piLast,                    /* IN/OUT: Lastest rowid seen so far */
+  int *pRc,                       /* OUT: Error code */
+  int *pbEof                      /* OUT: Set to true if EOF */
+){
+  i64 iLast = *piLast;
+  i64 iRowid;
+
+  iRowid = pIter->iRowid;
+  if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){
+    int rc = sqlite3Fts5IterNextFrom(pIter, iLast);
+    if( rc || sqlite3Fts5IterEof(pIter) ){
+      *pRc = rc;
+      *pbEof = 1;
+      return 1;
+    }
+    iRowid = pIter->iRowid;
+    assert( (bDesc==0 && iRowid>=iLast) || (bDesc==1 && iRowid<=iLast) );
+  }
+  *piLast = iRowid;
+
+  return 0;
+}
+
+static int fts5ExprSynonymAdvanceto(
+  Fts5ExprTerm *pTerm,            /* Term iterator to advance */
+  int bDesc,                      /* True if iterator is "rowid DESC" */
+  i64 *piLast,                    /* IN/OUT: Lastest rowid seen so far */
+  int *pRc                        /* OUT: Error code */
+){
+  int rc = SQLITE_OK;
+  i64 iLast = *piLast;
+  Fts5ExprTerm *p;
+  int bEof = 0;
+
+  for(p=pTerm; rc==SQLITE_OK && p; p=p->pSynonym){
+    if( sqlite3Fts5IterEof(p->pIter)==0 ){
+      i64 iRowid = p->pIter->iRowid;
+      if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){
+        rc = sqlite3Fts5IterNextFrom(p->pIter, iLast);
+      }
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    *pRc = rc;
+    bEof = 1;
+  }else{
+    *piLast = fts5ExprSynonymRowid(pTerm, bDesc, &bEof);
+  }
+  return bEof;
+}
+
+
+static int fts5ExprNearTest(
+  int *pRc,
+  Fts5Expr *pExpr,                /* Expression that pNear is a part of */
+  Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_STRING) */
+){
+  Fts5ExprNearset *pNear = pNode->pNear;
+  int rc = *pRc;
+
+  if( pExpr->pConfig->eDetail!=FTS5_DETAIL_FULL ){
+    Fts5ExprTerm *pTerm;
+    Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
+    pPhrase->poslist.n = 0;
+    for(pTerm=&pPhrase->aTerm[0]; pTerm; pTerm=pTerm->pSynonym){
+      Fts5IndexIter *pIter = pTerm->pIter;
+      if( sqlite3Fts5IterEof(pIter)==0 ){
+        if( pIter->iRowid==pNode->iRowid && pIter->nData>0 ){
+          pPhrase->poslist.n = 1;
+        }
+      }
+    }
+    return pPhrase->poslist.n;
+  }else{
+    int i;
+
+    /* Check that each phrase in the nearset matches the current row.
+    ** Populate the pPhrase->poslist buffers at the same time. If any
+    ** phrase is not a match, break out of the loop early.  */
+    for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
+      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+      if( pPhrase->nTerm>1 || pPhrase->aTerm[0].pSynonym || pNear->pColset ){
+        int bMatch = 0;
+        rc = fts5ExprPhraseIsMatch(pNode, pPhrase, &bMatch);
+        if( bMatch==0 ) break;
+      }else{
+        Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;
+        fts5BufferSet(&rc, &pPhrase->poslist, pIter->nData, pIter->pData);
+      }
+    }
+
+    *pRc = rc;
+    if( i==pNear->nPhrase && (i==1 || fts5ExprNearIsMatch(pRc, pNear)) ){
+      return 1;
+    }
+    return 0;
+  }
+}
+
+
+/*
+** Initialize all term iterators in the pNear object. If any term is found
+** to match no documents at all, return immediately without initializing any
+** further iterators.
+*/
+static int fts5ExprNearInitAll(
+  Fts5Expr *pExpr,
+  Fts5ExprNode *pNode
+){
+  Fts5ExprNearset *pNear = pNode->pNear;
+  int i, j;
+  int rc = SQLITE_OK;
+
+  assert( pNode->bNomatch==0 );
+  for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
+    Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+    for(j=0; j<pPhrase->nTerm; j++){
+      Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
+      Fts5ExprTerm *p;
+      int bEof = 1;
+
+      for(p=pTerm; p && rc==SQLITE_OK; p=p->pSynonym){
+        if( p->pIter ){
+          sqlite3Fts5IterClose(p->pIter);
+          p->pIter = 0;
+        }
+        rc = sqlite3Fts5IndexQuery(
+            pExpr->pIndex, p->zTerm, (int)strlen(p->zTerm),
+            (pTerm->bPrefix ? FTS5INDEX_QUERY_PREFIX : 0) |
+            (pExpr->bDesc ? FTS5INDEX_QUERY_DESC : 0),
+            pNear->pColset,
+            &p->pIter
+        );
+        assert( rc==SQLITE_OK || p->pIter==0 );
+        if( p->pIter && 0==sqlite3Fts5IterEof(p->pIter) ){
+          bEof = 0;
+        }
+      }
+
+      if( bEof ){
+        pNode->bEof = 1;
+        return rc;
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** If pExpr is an ASC iterator, this function returns a value with the
+** same sign as:
+**
+**   (iLhs - iRhs)
+**
+** Otherwise, if this is a DESC iterator, the opposite is returned:
+**
+**   (iRhs - iLhs)
+*/
+static int fts5RowidCmp(
+  Fts5Expr *pExpr,
+  i64 iLhs,
+  i64 iRhs
+){
+  assert( pExpr->bDesc==0 || pExpr->bDesc==1 );
+  if( pExpr->bDesc==0 ){
+    if( iLhs<iRhs ) return -1;
+    return (iLhs > iRhs);
+  }else{
+    if( iLhs>iRhs ) return -1;
+    return (iLhs < iRhs);
+  }
+}
+
+static void fts5ExprSetEof(Fts5ExprNode *pNode){
+  int i;
+  pNode->bEof = 1;
+  pNode->bNomatch = 0;
+  for(i=0; i<pNode->nChild; i++){
+    fts5ExprSetEof(pNode->apChild[i]);
+  }
+}
+
+static void fts5ExprNodeZeroPoslist(Fts5ExprNode *pNode){
+  if( pNode->eType==FTS5_STRING || pNode->eType==FTS5_TERM ){
+    Fts5ExprNearset *pNear = pNode->pNear;
+    int i;
+    for(i=0; i<pNear->nPhrase; i++){
+      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+      pPhrase->poslist.n = 0;
+    }
+  }else{
+    int i;
+    for(i=0; i<pNode->nChild; i++){
+      fts5ExprNodeZeroPoslist(pNode->apChild[i]);
+    }
+  }
+}
+
+
+
+/*
+** Compare the values currently indicated by the two nodes as follows:
+**
+**    res = (*p1) - (*p2)
+**
+** Nodes that point to values that come later in the iteration order are
+** considered to be larger. Nodes at EOF are the largest of all.
+**
+** This means that if the iteration order is ASC, then numerically larger
+** rowids are considered larger. Or if it is the default DESC, numerically
+** smaller rowids are larger.
+*/
+static int fts5NodeCompare(
+  Fts5Expr *pExpr,
+  Fts5ExprNode *p1, 
+  Fts5ExprNode *p2
+){
+  if( p2->bEof ) return -1;
+  if( p1->bEof ) return +1;
+  return fts5RowidCmp(pExpr, p1->iRowid, p2->iRowid);
+}
+
+/*
+** All individual term iterators in pNear are guaranteed to be valid when
+** this function is called. This function checks if all term iterators
+** point to the same rowid, and if not, advances them until they do.
+** If an EOF is reached before this happens, *pbEof is set to true before
+** returning.
+**
+** SQLITE_OK is returned if an error occurs, or an SQLite error code 
+** otherwise. It is not considered an error code if an iterator reaches
+** EOF.
+*/
+static int fts5ExprNodeTest_STRING(
+  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
+  Fts5ExprNode *pNode
+){
+  Fts5ExprNearset *pNear = pNode->pNear;
+  Fts5ExprPhrase *pLeft = pNear->apPhrase[0];
+  int rc = SQLITE_OK;
+  i64 iLast;                      /* Lastest rowid any iterator points to */
+  int i, j;                       /* Phrase and token index, respectively */
+  int bMatch;                     /* True if all terms are at the same rowid */
+  const int bDesc = pExpr->bDesc;
+
+  /* Check that this node should not be FTS5_TERM */
+  assert( pNear->nPhrase>1 
+       || pNear->apPhrase[0]->nTerm>1 
+       || pNear->apPhrase[0]->aTerm[0].pSynonym
+  );
+
+  /* Initialize iLast, the "lastest" rowid any iterator points to. If the
+  ** iterator skips through rowids in the default ascending order, this means
+  ** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it
+  ** means the minimum rowid.  */
+  if( pLeft->aTerm[0].pSynonym ){
+    iLast = fts5ExprSynonymRowid(&pLeft->aTerm[0], bDesc, 0);
+  }else{
+    iLast = pLeft->aTerm[0].pIter->iRowid;
+  }
+
+  do {
+    bMatch = 1;
+    for(i=0; i<pNear->nPhrase; i++){
+      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+      for(j=0; j<pPhrase->nTerm; j++){
+        Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];
+        if( pTerm->pSynonym ){
+          i64 iRowid = fts5ExprSynonymRowid(pTerm, bDesc, 0);
+          if( iRowid==iLast ) continue;
+          bMatch = 0;
+          if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){
+            pNode->bNomatch = 0;
+            pNode->bEof = 1;
+            return rc;
+          }
+        }else{
+          Fts5IndexIter *pIter = pPhrase->aTerm[j].pIter;
+          if( pIter->iRowid==iLast ) continue;
+          bMatch = 0;
+          if( fts5ExprAdvanceto(pIter, bDesc, &iLast, &rc, &pNode->bEof) ){
+            return rc;
+          }
+        }
+      }
+    }
+  }while( bMatch==0 );
+
+  pNode->iRowid = iLast;
+  pNode->bNomatch = ((0==fts5ExprNearTest(&rc, pExpr, pNode)) && rc==SQLITE_OK);
+  assert( pNode->bEof==0 || pNode->bNomatch==0 );
+
+  return rc;
+}
+
+/*
+** Advance the first term iterator in the first phrase of pNear. Set output
+** variable *pbEof to true if it reaches EOF or if an error occurs.
+**
+** Return SQLITE_OK if successful, or an SQLite error code if an error
+** occurs.
+*/
+static int fts5ExprNodeNext_STRING(
+  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
+  Fts5ExprNode *pNode,            /* FTS5_STRING or FTS5_TERM node */
+  int bFromValid,
+  i64 iFrom 
+){
+  Fts5ExprTerm *pTerm = &pNode->pNear->apPhrase[0]->aTerm[0];
+  int rc = SQLITE_OK;
+
+  pNode->bNomatch = 0;
+  if( pTerm->pSynonym ){
+    int bEof = 1;
+    Fts5ExprTerm *p;
+
+    /* Find the firstest rowid any synonym points to. */
+    i64 iRowid = fts5ExprSynonymRowid(pTerm, pExpr->bDesc, 0);
+
+    /* Advance each iterator that currently points to iRowid. Or, if iFrom
+    ** is valid - each iterator that points to a rowid before iFrom.  */
+    for(p=pTerm; p; p=p->pSynonym){
+      if( sqlite3Fts5IterEof(p->pIter)==0 ){
+        i64 ii = p->pIter->iRowid;
+        if( ii==iRowid 
+         || (bFromValid && ii!=iFrom && (ii>iFrom)==pExpr->bDesc) 
+        ){
+          if( bFromValid ){
+            rc = sqlite3Fts5IterNextFrom(p->pIter, iFrom);
+          }else{
+            rc = sqlite3Fts5IterNext(p->pIter);
+          }
+          if( rc!=SQLITE_OK ) break;
+          if( sqlite3Fts5IterEof(p->pIter)==0 ){
+            bEof = 0;
+          }
+        }else{
+          bEof = 0;
+        }
+      }
+    }
+
+    /* Set the EOF flag if either all synonym iterators are at EOF or an
+    ** error has occurred.  */
+    pNode->bEof = (rc || bEof);
+  }else{
+    Fts5IndexIter *pIter = pTerm->pIter;
+
+    assert( Fts5NodeIsString(pNode) );
+    if( bFromValid ){
+      rc = sqlite3Fts5IterNextFrom(pIter, iFrom);
+    }else{
+      rc = sqlite3Fts5IterNext(pIter);
+    }
+
+    pNode->bEof = (rc || sqlite3Fts5IterEof(pIter));
+  }
+
+  if( pNode->bEof==0 ){
+    assert( rc==SQLITE_OK );
+    rc = fts5ExprNodeTest_STRING(pExpr, pNode);
+  }
+
+  return rc;
+}
+
+
+static int fts5ExprNodeTest_TERM(
+  Fts5Expr *pExpr,                /* Expression that pNear is a part of */
+  Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_TERM) */
+){
+  /* As this "NEAR" object is actually a single phrase that consists 
+  ** of a single term only, grab pointers into the poslist managed by the
+  ** fts5_index.c iterator object. This is much faster than synthesizing 
+  ** a new poslist the way we have to for more complicated phrase or NEAR
+  ** expressions.  */
+  Fts5ExprPhrase *pPhrase = pNode->pNear->apPhrase[0];
+  Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;
+
+  assert( pNode->eType==FTS5_TERM );
+  assert( pNode->pNear->nPhrase==1 && pPhrase->nTerm==1 );
+  assert( pPhrase->aTerm[0].pSynonym==0 );
+
+  pPhrase->poslist.n = pIter->nData;
+  if( pExpr->pConfig->eDetail==FTS5_DETAIL_FULL ){
+    pPhrase->poslist.p = (u8*)pIter->pData;
+  }
+  pNode->iRowid = pIter->iRowid;
+  pNode->bNomatch = (pPhrase->poslist.n==0);
+  return SQLITE_OK;
+}
+
+/*
+** xNext() method for a node of type FTS5_TERM.
+*/
+static int fts5ExprNodeNext_TERM(
+  Fts5Expr *pExpr, 
+  Fts5ExprNode *pNode,
+  int bFromValid,
+  i64 iFrom
+){
+  int rc;
+  Fts5IndexIter *pIter = pNode->pNear->apPhrase[0]->aTerm[0].pIter;
+
+  assert( pNode->bEof==0 );
+  if( bFromValid ){
+    rc = sqlite3Fts5IterNextFrom(pIter, iFrom);
+  }else{
+    rc = sqlite3Fts5IterNext(pIter);
+  }
+  if( rc==SQLITE_OK && sqlite3Fts5IterEof(pIter)==0 ){
+    rc = fts5ExprNodeTest_TERM(pExpr, pNode);
+  }else{
+    pNode->bEof = 1;
+    pNode->bNomatch = 0;
+  }
+  return rc;
+}
+
+static void fts5ExprNodeTest_OR(
+  Fts5Expr *pExpr,                /* Expression of which pNode is a part */
+  Fts5ExprNode *pNode             /* Expression node to test */
+){
+  Fts5ExprNode *pNext = pNode->apChild[0];
+  int i;
+
+  for(i=1; i<pNode->nChild; i++){
+    Fts5ExprNode *pChild = pNode->apChild[i];
+    int cmp = fts5NodeCompare(pExpr, pNext, pChild);
+    if( cmp>0 || (cmp==0 && pChild->bNomatch==0) ){
+      pNext = pChild;
+    }
+  }
+  pNode->iRowid = pNext->iRowid;
+  pNode->bEof = pNext->bEof;
+  pNode->bNomatch = pNext->bNomatch;
+}
+
+static int fts5ExprNodeNext_OR(
+  Fts5Expr *pExpr, 
+  Fts5ExprNode *pNode,
+  int bFromValid,
+  i64 iFrom
+){
+  int i;
+  i64 iLast = pNode->iRowid;
+
+  for(i=0; i<pNode->nChild; i++){
+    Fts5ExprNode *p1 = pNode->apChild[i];
+    assert( p1->bEof || fts5RowidCmp(pExpr, p1->iRowid, iLast)>=0 );
+    if( p1->bEof==0 ){
+      if( (p1->iRowid==iLast) 
+       || (bFromValid && fts5RowidCmp(pExpr, p1->iRowid, iFrom)<0)
+      ){
+        int rc = fts5ExprNodeNext(pExpr, p1, bFromValid, iFrom);
+        if( rc!=SQLITE_OK ) return rc;
+      }
+    }
+  }
+
+  fts5ExprNodeTest_OR(pExpr, pNode);
+  return SQLITE_OK;
+}
+
+/*
+** Argument pNode is an FTS5_AND node.
+*/
+static int fts5ExprNodeTest_AND(
+  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
+  Fts5ExprNode *pAnd              /* FTS5_AND node to advance */
+){
+  int iChild;
+  i64 iLast = pAnd->iRowid;
+  int rc = SQLITE_OK;
+  int bMatch;
+
+  assert( pAnd->bEof==0 );
+  do {
+    pAnd->bNomatch = 0;
+    bMatch = 1;
+    for(iChild=0; iChild<pAnd->nChild; iChild++){
+      Fts5ExprNode *pChild = pAnd->apChild[iChild];
+      int cmp = fts5RowidCmp(pExpr, iLast, pChild->iRowid);
+      if( cmp>0 ){
+        /* Advance pChild until it points to iLast or laster */
+        rc = fts5ExprNodeNext(pExpr, pChild, 1, iLast);
+        if( rc!=SQLITE_OK ) return rc;
+      }
+
+      /* If the child node is now at EOF, so is the parent AND node. Otherwise,
+      ** the child node is guaranteed to have advanced at least as far as
+      ** rowid iLast. So if it is not at exactly iLast, pChild->iRowid is the
+      ** new lastest rowid seen so far.  */
+      assert( pChild->bEof || fts5RowidCmp(pExpr, iLast, pChild->iRowid)<=0 );
+      if( pChild->bEof ){
+        fts5ExprSetEof(pAnd);
+        bMatch = 1;
+        break;
+      }else if( iLast!=pChild->iRowid ){
+        bMatch = 0;
+        iLast = pChild->iRowid;
+      }
+
+      if( pChild->bNomatch ){
+        pAnd->bNomatch = 1;
+      }
+    }
+  }while( bMatch==0 );
+
+  if( pAnd->bNomatch && pAnd!=pExpr->pRoot ){
+    fts5ExprNodeZeroPoslist(pAnd);
+  }
+  pAnd->iRowid = iLast;
+  return SQLITE_OK;
+}
+
+static int fts5ExprNodeNext_AND(
+  Fts5Expr *pExpr, 
+  Fts5ExprNode *pNode,
+  int bFromValid,
+  i64 iFrom
+){
+  int rc = fts5ExprNodeNext(pExpr, pNode->apChild[0], bFromValid, iFrom);
+  if( rc==SQLITE_OK ){
+    rc = fts5ExprNodeTest_AND(pExpr, pNode);
+  }
+  return rc;
+}
+
+static int fts5ExprNodeTest_NOT(
+  Fts5Expr *pExpr,                /* Expression pPhrase belongs to */
+  Fts5ExprNode *pNode             /* FTS5_NOT node to advance */
+){
+  int rc = SQLITE_OK;
+  Fts5ExprNode *p1 = pNode->apChild[0];
+  Fts5ExprNode *p2 = pNode->apChild[1];
+  assert( pNode->nChild==2 );
+
+  while( rc==SQLITE_OK && p1->bEof==0 ){
+    int cmp = fts5NodeCompare(pExpr, p1, p2);
+    if( cmp>0 ){
+      rc = fts5ExprNodeNext(pExpr, p2, 1, p1->iRowid);
+      cmp = fts5NodeCompare(pExpr, p1, p2);
+    }
+    assert( rc!=SQLITE_OK || cmp<=0 );
+    if( cmp || p2->bNomatch ) break;
+    rc = fts5ExprNodeNext(pExpr, p1, 0, 0);
+  }
+  pNode->bEof = p1->bEof;
+  pNode->bNomatch = p1->bNomatch;
+  pNode->iRowid = p1->iRowid;
+  if( p1->bEof ){
+    fts5ExprNodeZeroPoslist(p2);
+  }
+  return rc;
+}
+
+static int fts5ExprNodeNext_NOT(
+  Fts5Expr *pExpr, 
+  Fts5ExprNode *pNode,
+  int bFromValid,
+  i64 iFrom
+){
+  int rc = fts5ExprNodeNext(pExpr, pNode->apChild[0], bFromValid, iFrom);
+  if( rc==SQLITE_OK ){
+    rc = fts5ExprNodeTest_NOT(pExpr, pNode);
+  }
+  return rc;
+}
+
+/*
+** If pNode currently points to a match, this function returns SQLITE_OK
+** without modifying it. Otherwise, pNode is advanced until it does point
+** to a match or EOF is reached.
+*/
+static int fts5ExprNodeTest(
+  Fts5Expr *pExpr,                /* Expression of which pNode is a part */
+  Fts5ExprNode *pNode             /* Expression node to test */
+){
+  int rc = SQLITE_OK;
+  if( pNode->bEof==0 ){
+    switch( pNode->eType ){
+
+      case FTS5_STRING: {
+        rc = fts5ExprNodeTest_STRING(pExpr, pNode);
+        break;
+      }
+
+      case FTS5_TERM: {
+        rc = fts5ExprNodeTest_TERM(pExpr, pNode);
+        break;
+      }
+
+      case FTS5_AND: {
+        rc = fts5ExprNodeTest_AND(pExpr, pNode);
+        break;
+      }
+
+      case FTS5_OR: {
+        fts5ExprNodeTest_OR(pExpr, pNode);
+        break;
+      }
+
+      default: assert( pNode->eType==FTS5_NOT ); {
+        rc = fts5ExprNodeTest_NOT(pExpr, pNode);
+        break;
+      }
+    }
+  }
+  return rc;
+}
+
+ 
+/*
+** Set node pNode, which is part of expression pExpr, to point to the first
+** match. If there are no matches, set the Node.bEof flag to indicate EOF.
+**
+** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.
+** It is not an error if there are no matches.
+*/
+static int fts5ExprNodeFirst(Fts5Expr *pExpr, Fts5ExprNode *pNode){
+  int rc = SQLITE_OK;
+  pNode->bEof = 0;
+  pNode->bNomatch = 0;
+
+  if( Fts5NodeIsString(pNode) ){
+    /* Initialize all term iterators in the NEAR object. */
+    rc = fts5ExprNearInitAll(pExpr, pNode);
+  }else if( pNode->xNext==0 ){
+    pNode->bEof = 1;
+  }else{
+    int i;
+    int nEof = 0;
+    for(i=0; i<pNode->nChild && rc==SQLITE_OK; i++){
+      Fts5ExprNode *pChild = pNode->apChild[i];
+      rc = fts5ExprNodeFirst(pExpr, pNode->apChild[i]);
+      assert( pChild->bEof==0 || pChild->bEof==1 );
+      nEof += pChild->bEof;
+    }
+    pNode->iRowid = pNode->apChild[0]->iRowid;
+
+    switch( pNode->eType ){
+      case FTS5_AND:
+        if( nEof>0 ) fts5ExprSetEof(pNode);
+        break;
+
+      case FTS5_OR:
+        if( pNode->nChild==nEof ) fts5ExprSetEof(pNode);
+        break;
+
+      default:
+        assert( pNode->eType==FTS5_NOT );
+        pNode->bEof = pNode->apChild[0]->bEof;
+        break;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = fts5ExprNodeTest(pExpr, pNode);
+  }
+  return rc;
+}
+
+
+/*
+** Begin iterating through the set of documents in index pIdx matched by
+** the MATCH expression passed as the first argument. If the "bDesc" 
+** parameter is passed a non-zero value, iteration is in descending rowid 
+** order. Or, if it is zero, in ascending order.
+**
+** If iterating in ascending rowid order (bDesc==0), the first document
+** visited is that with the smallest rowid that is larger than or equal
+** to parameter iFirst. Or, if iterating in ascending order (bDesc==1),
+** then the first document visited must have a rowid smaller than or
+** equal to iFirst.
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
+** is not considered an error if the query does not match any documents.
+*/
+static int sqlite3Fts5ExprFirst(Fts5Expr *p, Fts5Index *pIdx, i64 iFirst, int bDesc){
+  Fts5ExprNode *pRoot = p->pRoot;
+  int rc;                         /* Return code */
+
+  p->pIndex = pIdx;
+  p->bDesc = bDesc;
+  rc = fts5ExprNodeFirst(p, pRoot);
+
+  /* If not at EOF but the current rowid occurs earlier than iFirst in
+  ** the iteration order, move to document iFirst or later. */
+  if( pRoot->bEof==0 && fts5RowidCmp(p, pRoot->iRowid, iFirst)<0 ){
+    rc = fts5ExprNodeNext(p, pRoot, 1, iFirst);
+  }
+
+  /* If the iterator is not at a real match, skip forward until it is. */
+  while( pRoot->bNomatch ){
+    assert( pRoot->bEof==0 && rc==SQLITE_OK );
+    rc = fts5ExprNodeNext(p, pRoot, 0, 0);
+  }
+  return rc;
+}
+
+/*
+** Move to the next document 
+**
+** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
+** is not considered an error if the query does not match any documents.
+*/
+static int sqlite3Fts5ExprNext(Fts5Expr *p, i64 iLast){
+  int rc;
+  Fts5ExprNode *pRoot = p->pRoot;
+  assert( pRoot->bEof==0 && pRoot->bNomatch==0 );
+  do {
+    rc = fts5ExprNodeNext(p, pRoot, 0, 0);
+    assert( pRoot->bNomatch==0 || (rc==SQLITE_OK && pRoot->bEof==0) );
+  }while( pRoot->bNomatch );
+  if( fts5RowidCmp(p, pRoot->iRowid, iLast)>0 ){
+    pRoot->bEof = 1;
+  }
+  return rc;
+}
+
+static int sqlite3Fts5ExprEof(Fts5Expr *p){
+  return p->pRoot->bEof;
+}
+
+static i64 sqlite3Fts5ExprRowid(Fts5Expr *p){
+  return p->pRoot->iRowid;
+}
+
+static int fts5ParseStringFromToken(Fts5Token *pToken, char **pz){
+  int rc = SQLITE_OK;
+  *pz = sqlite3Fts5Strndup(&rc, pToken->p, pToken->n);
+  return rc;
+}
+
+/*
+** Free the phrase object passed as the only argument.
+*/
+static void fts5ExprPhraseFree(Fts5ExprPhrase *pPhrase){
+  if( pPhrase ){
+    int i;
+    for(i=0; i<pPhrase->nTerm; i++){
+      Fts5ExprTerm *pSyn;
+      Fts5ExprTerm *pNext;
+      Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];
+      sqlite3_free(pTerm->zTerm);
+      sqlite3Fts5IterClose(pTerm->pIter);
+      for(pSyn=pTerm->pSynonym; pSyn; pSyn=pNext){
+        pNext = pSyn->pSynonym;
+        sqlite3Fts5IterClose(pSyn->pIter);
+        fts5BufferFree((Fts5Buffer*)&pSyn[1]);
+        sqlite3_free(pSyn);
+      }
+    }
+    if( pPhrase->poslist.nSpace>0 ) fts5BufferFree(&pPhrase->poslist);
+    sqlite3_free(pPhrase);
+  }
+}
+
+/*
+** If argument pNear is NULL, then a new Fts5ExprNearset object is allocated
+** and populated with pPhrase. Or, if pNear is not NULL, phrase pPhrase is
+** appended to it and the results returned.
+**
+** If an OOM error occurs, both the pNear and pPhrase objects are freed and
+** NULL returned.
+*/
+static Fts5ExprNearset *sqlite3Fts5ParseNearset(
+  Fts5Parse *pParse,              /* Parse context */
+  Fts5ExprNearset *pNear,         /* Existing nearset, or NULL */
+  Fts5ExprPhrase *pPhrase         /* Recently parsed phrase */
+){
+  const int SZALLOC = 8;
+  Fts5ExprNearset *pRet = 0;
+
+  if( pParse->rc==SQLITE_OK ){
+    if( pPhrase==0 ){
+      return pNear;
+    }
+    if( pNear==0 ){
+      int nByte = sizeof(Fts5ExprNearset) + SZALLOC * sizeof(Fts5ExprPhrase*);
+      pRet = sqlite3_malloc(nByte);
+      if( pRet==0 ){
+        pParse->rc = SQLITE_NOMEM;
+      }else{
+        memset(pRet, 0, nByte);
+      }
+    }else if( (pNear->nPhrase % SZALLOC)==0 ){
+      int nNew = pNear->nPhrase + SZALLOC;
+      int nByte = sizeof(Fts5ExprNearset) + nNew * sizeof(Fts5ExprPhrase*);
+
+      pRet = (Fts5ExprNearset*)sqlite3_realloc(pNear, nByte);
+      if( pRet==0 ){
+        pParse->rc = SQLITE_NOMEM;
+      }
+    }else{
+      pRet = pNear;
+    }
+  }
+
+  if( pRet==0 ){
+    assert( pParse->rc!=SQLITE_OK );
+    sqlite3Fts5ParseNearsetFree(pNear);
+    sqlite3Fts5ParsePhraseFree(pPhrase);
+  }else{
+    if( pRet->nPhrase>0 ){
+      Fts5ExprPhrase *pLast = pRet->apPhrase[pRet->nPhrase-1];
+      assert( pLast==pParse->apPhrase[pParse->nPhrase-2] );
+      if( pPhrase->nTerm==0 ){
+        fts5ExprPhraseFree(pPhrase);
+        pRet->nPhrase--;
+        pParse->nPhrase--;
+        pPhrase = pLast;
+      }else if( pLast->nTerm==0 ){
+        fts5ExprPhraseFree(pLast);
+        pParse->apPhrase[pParse->nPhrase-2] = pPhrase;
+        pParse->nPhrase--;
+        pRet->nPhrase--;
+      }
+    }
+    pRet->apPhrase[pRet->nPhrase++] = pPhrase;
+  }
+  return pRet;
+}
+
+typedef struct TokenCtx TokenCtx;
+struct TokenCtx {
+  Fts5ExprPhrase *pPhrase;
+  int rc;
+};
+
+/*
+** Callback for tokenizing terms used by ParseTerm().
+*/
+static int fts5ParseTokenize(
+  void *pContext,                 /* Pointer to Fts5InsertCtx object */
+  int tflags,                     /* Mask of FTS5_TOKEN_* flags */
+  const char *pToken,             /* Buffer containing token */
+  int nToken,                     /* Size of token in bytes */
+  int iUnused1,                   /* Start offset of token */
+  int iUnused2                    /* End offset of token */
+){
+  int rc = SQLITE_OK;
+  const int SZALLOC = 8;
+  TokenCtx *pCtx = (TokenCtx*)pContext;
+  Fts5ExprPhrase *pPhrase = pCtx->pPhrase;
+
+  UNUSED_PARAM2(iUnused1, iUnused2);
+
+  /* If an error has already occurred, this is a no-op */
+  if( pCtx->rc!=SQLITE_OK ) return pCtx->rc;
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
+
+  if( pPhrase && pPhrase->nTerm>0 && (tflags & FTS5_TOKEN_COLOCATED) ){
+    Fts5ExprTerm *pSyn;
+    int nByte = sizeof(Fts5ExprTerm) + sizeof(Fts5Buffer) + nToken+1;
+    pSyn = (Fts5ExprTerm*)sqlite3_malloc(nByte);
+    if( pSyn==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pSyn, 0, nByte);
+      pSyn->zTerm = ((char*)pSyn) + sizeof(Fts5ExprTerm) + sizeof(Fts5Buffer);
+      memcpy(pSyn->zTerm, pToken, nToken);
+      pSyn->pSynonym = pPhrase->aTerm[pPhrase->nTerm-1].pSynonym;
+      pPhrase->aTerm[pPhrase->nTerm-1].pSynonym = pSyn;
+    }
+  }else{
+    Fts5ExprTerm *pTerm;
+    if( pPhrase==0 || (pPhrase->nTerm % SZALLOC)==0 ){
+      Fts5ExprPhrase *pNew;
+      int nNew = SZALLOC + (pPhrase ? pPhrase->nTerm : 0);
+
+      pNew = (Fts5ExprPhrase*)sqlite3_realloc(pPhrase, 
+          sizeof(Fts5ExprPhrase) + sizeof(Fts5ExprTerm) * nNew
+      );
+      if( pNew==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        if( pPhrase==0 ) memset(pNew, 0, sizeof(Fts5ExprPhrase));
+        pCtx->pPhrase = pPhrase = pNew;
+        pNew->nTerm = nNew - SZALLOC;
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      pTerm = &pPhrase->aTerm[pPhrase->nTerm++];
+      memset(pTerm, 0, sizeof(Fts5ExprTerm));
+      pTerm->zTerm = sqlite3Fts5Strndup(&rc, pToken, nToken);
+    }
+  }
+
+  pCtx->rc = rc;
+  return rc;
+}
+
+
+/*
+** Free the phrase object passed as the only argument.
+*/
+static void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase *pPhrase){
+  fts5ExprPhraseFree(pPhrase);
+}
+
+/*
+** Free the phrase object passed as the second argument.
+*/
+static void sqlite3Fts5ParseNearsetFree(Fts5ExprNearset *pNear){
+  if( pNear ){
+    int i;
+    for(i=0; i<pNear->nPhrase; i++){
+      fts5ExprPhraseFree(pNear->apPhrase[i]);
+    }
+    sqlite3_free(pNear->pColset);
+    sqlite3_free(pNear);
+  }
+}
+
+static void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p){
+  assert( pParse->pExpr==0 );
+  pParse->pExpr = p;
+}
+
+/*
+** This function is called by the parser to process a string token. The
+** string may or may not be quoted. In any case it is tokenized and a
+** phrase object consisting of all tokens returned.
+*/
+static Fts5ExprPhrase *sqlite3Fts5ParseTerm(
+  Fts5Parse *pParse,              /* Parse context */
+  Fts5ExprPhrase *pAppend,        /* Phrase to append to */
+  Fts5Token *pToken,              /* String to tokenize */
+  int bPrefix                     /* True if there is a trailing "*" */
+){
+  Fts5Config *pConfig = pParse->pConfig;
+  TokenCtx sCtx;                  /* Context object passed to callback */
+  int rc;                         /* Tokenize return code */
+  char *z = 0;
+
+  memset(&sCtx, 0, sizeof(TokenCtx));
+  sCtx.pPhrase = pAppend;
+
+  rc = fts5ParseStringFromToken(pToken, &z);
+  if( rc==SQLITE_OK ){
+    int flags = FTS5_TOKENIZE_QUERY | (bPrefix ? FTS5_TOKENIZE_QUERY : 0);
+    int n;
+    sqlite3Fts5Dequote(z);
+    n = (int)strlen(z);
+    rc = sqlite3Fts5Tokenize(pConfig, flags, z, n, &sCtx, fts5ParseTokenize);
+  }
+  sqlite3_free(z);
+  if( rc || (rc = sCtx.rc) ){
+    pParse->rc = rc;
+    fts5ExprPhraseFree(sCtx.pPhrase);
+    sCtx.pPhrase = 0;
+  }else{
+
+    if( pAppend==0 ){
+      if( (pParse->nPhrase % 8)==0 ){
+        int nByte = sizeof(Fts5ExprPhrase*) * (pParse->nPhrase + 8);
+        Fts5ExprPhrase **apNew;
+        apNew = (Fts5ExprPhrase**)sqlite3_realloc(pParse->apPhrase, nByte);
+        if( apNew==0 ){
+          pParse->rc = SQLITE_NOMEM;
+          fts5ExprPhraseFree(sCtx.pPhrase);
+          return 0;
+        }
+        pParse->apPhrase = apNew;
+      }
+      pParse->nPhrase++;
+    }
+
+    if( sCtx.pPhrase==0 ){
+      /* This happens when parsing a token or quoted phrase that contains
+      ** no token characters at all. (e.g ... MATCH '""'). */
+      sCtx.pPhrase = sqlite3Fts5MallocZero(&pParse->rc, sizeof(Fts5ExprPhrase));
+    }else if( sCtx.pPhrase->nTerm ){
+      sCtx.pPhrase->aTerm[sCtx.pPhrase->nTerm-1].bPrefix = bPrefix;
+    }
+    pParse->apPhrase[pParse->nPhrase-1] = sCtx.pPhrase;
+  }
+
+  return sCtx.pPhrase;
+}
+
+/*
+** Create a new FTS5 expression by cloning phrase iPhrase of the
+** expression passed as the second argument.
+*/
+static int sqlite3Fts5ExprClonePhrase(
+  Fts5Expr *pExpr, 
+  int iPhrase, 
+  Fts5Expr **ppNew
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5ExprPhrase *pOrig;          /* The phrase extracted from pExpr */
+  int i;                          /* Used to iterate through phrase terms */
+  Fts5Expr *pNew = 0;             /* Expression to return via *ppNew */
+  TokenCtx sCtx = {0,0};          /* Context object for fts5ParseTokenize */
+
+  pOrig = pExpr->apExprPhrase[iPhrase];
+  pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));
+  if( rc==SQLITE_OK ){
+    pNew->apExprPhrase = (Fts5ExprPhrase**)sqlite3Fts5MallocZero(&rc, 
+        sizeof(Fts5ExprPhrase*));
+  }
+  if( rc==SQLITE_OK ){
+    pNew->pRoot = (Fts5ExprNode*)sqlite3Fts5MallocZero(&rc, 
+        sizeof(Fts5ExprNode));
+  }
+  if( rc==SQLITE_OK ){
+    pNew->pRoot->pNear = (Fts5ExprNearset*)sqlite3Fts5MallocZero(&rc, 
+        sizeof(Fts5ExprNearset) + sizeof(Fts5ExprPhrase*));
+  }
+  if( rc==SQLITE_OK ){
+    Fts5Colset *pColsetOrig = pOrig->pNode->pNear->pColset;
+    if( pColsetOrig ){
+      int nByte = sizeof(Fts5Colset) + pColsetOrig->nCol * sizeof(int);
+      Fts5Colset *pColset = (Fts5Colset*)sqlite3Fts5MallocZero(&rc, nByte);
+      if( pColset ){ 
+        memcpy(pColset, pColsetOrig, nByte);
+      }
+      pNew->pRoot->pNear->pColset = pColset;
+    }
+  }
+
+  for(i=0; rc==SQLITE_OK && i<pOrig->nTerm; i++){
+    int tflags = 0;
+    Fts5ExprTerm *p;
+    for(p=&pOrig->aTerm[i]; p && rc==SQLITE_OK; p=p->pSynonym){
+      const char *zTerm = p->zTerm;
+      rc = fts5ParseTokenize((void*)&sCtx, tflags, zTerm, (int)strlen(zTerm),
+          0, 0);
+      tflags = FTS5_TOKEN_COLOCATED;
+    }
+    if( rc==SQLITE_OK ){
+      sCtx.pPhrase->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    /* All the allocations succeeded. Put the expression object together. */
+    pNew->pIndex = pExpr->pIndex;
+    pNew->pConfig = pExpr->pConfig;
+    pNew->nPhrase = 1;
+    pNew->apExprPhrase[0] = sCtx.pPhrase;
+    pNew->pRoot->pNear->apPhrase[0] = sCtx.pPhrase;
+    pNew->pRoot->pNear->nPhrase = 1;
+    sCtx.pPhrase->pNode = pNew->pRoot;
+
+    if( pOrig->nTerm==1 && pOrig->aTerm[0].pSynonym==0 ){
+      pNew->pRoot->eType = FTS5_TERM;
+      pNew->pRoot->xNext = fts5ExprNodeNext_TERM;
+    }else{
+      pNew->pRoot->eType = FTS5_STRING;
+      pNew->pRoot->xNext = fts5ExprNodeNext_STRING;
+    }
+  }else{
+    sqlite3Fts5ExprFree(pNew);
+    fts5ExprPhraseFree(sCtx.pPhrase);
+    pNew = 0;
+  }
+
+  *ppNew = pNew;
+  return rc;
+}
+
+
+/*
+** Token pTok has appeared in a MATCH expression where the NEAR operator
+** is expected. If token pTok does not contain "NEAR", store an error
+** in the pParse object.
+*/
+static void sqlite3Fts5ParseNear(Fts5Parse *pParse, Fts5Token *pTok){
+  if( pTok->n!=4 || memcmp("NEAR", pTok->p, 4) ){
+    sqlite3Fts5ParseError(
+        pParse, "fts5: syntax error near \"%.*s\"", pTok->n, pTok->p
+    );
+  }
+}
+
+static void sqlite3Fts5ParseSetDistance(
+  Fts5Parse *pParse, 
+  Fts5ExprNearset *pNear,
+  Fts5Token *p
+){
+  if( pNear ){
+    int nNear = 0;
+    int i;
+    if( p->n ){
+      for(i=0; i<p->n; i++){
+        char c = (char)p->p[i];
+        if( c<'0' || c>'9' ){
+          sqlite3Fts5ParseError(
+              pParse, "expected integer, got \"%.*s\"", p->n, p->p
+              );
+          return;
+        }
+        nNear = nNear * 10 + (p->p[i] - '0');
+      }
+    }else{
+      nNear = FTS5_DEFAULT_NEARDIST;
+    }
+    pNear->nNear = nNear;
+  }
+}
+
+/*
+** The second argument passed to this function may be NULL, or it may be
+** an existing Fts5Colset object. This function returns a pointer to
+** a new colset object containing the contents of (p) with new value column
+** number iCol appended. 
+**
+** If an OOM error occurs, store an error code in pParse and return NULL.
+** The old colset object (if any) is not freed in this case.
+*/
+static Fts5Colset *fts5ParseColset(
+  Fts5Parse *pParse,              /* Store SQLITE_NOMEM here if required */
+  Fts5Colset *p,                  /* Existing colset object */
+  int iCol                        /* New column to add to colset object */
+){
+  int nCol = p ? p->nCol : 0;     /* Num. columns already in colset object */
+  Fts5Colset *pNew;               /* New colset object to return */
+
+  assert( pParse->rc==SQLITE_OK );
+  assert( iCol>=0 && iCol<pParse->pConfig->nCol );
+
+  pNew = sqlite3_realloc(p, sizeof(Fts5Colset) + sizeof(int)*nCol);
+  if( pNew==0 ){
+    pParse->rc = SQLITE_NOMEM;
+  }else{
+    int *aiCol = pNew->aiCol;
+    int i, j;
+    for(i=0; i<nCol; i++){
+      if( aiCol[i]==iCol ) return pNew;
+      if( aiCol[i]>iCol ) break;
+    }
+    for(j=nCol; j>i; j--){
+      aiCol[j] = aiCol[j-1];
+    }
+    aiCol[i] = iCol;
+    pNew->nCol = nCol+1;
+
+#ifndef NDEBUG
+    /* Check that the array is in order and contains no duplicate entries. */
+    for(i=1; i<pNew->nCol; i++) assert( pNew->aiCol[i]>pNew->aiCol[i-1] );
+#endif
+  }
+
+  return pNew;
+}
+
+static Fts5Colset *sqlite3Fts5ParseColset(
+  Fts5Parse *pParse,              /* Store SQLITE_NOMEM here if required */
+  Fts5Colset *pColset,            /* Existing colset object */
+  Fts5Token *p
+){
+  Fts5Colset *pRet = 0;
+  int iCol;
+  char *z;                        /* Dequoted copy of token p */
+
+  z = sqlite3Fts5Strndup(&pParse->rc, p->p, p->n);
+  if( pParse->rc==SQLITE_OK ){
+    Fts5Config *pConfig = pParse->pConfig;
+    sqlite3Fts5Dequote(z);
+    for(iCol=0; iCol<pConfig->nCol; iCol++){
+      if( 0==sqlite3_stricmp(pConfig->azCol[iCol], z) ) break;
+    }
+    if( iCol==pConfig->nCol ){
+      sqlite3Fts5ParseError(pParse, "no such column: %s", z);
+    }else{
+      pRet = fts5ParseColset(pParse, pColset, iCol);
+    }
+    sqlite3_free(z);
+  }
+
+  if( pRet==0 ){
+    assert( pParse->rc!=SQLITE_OK );
+    sqlite3_free(pColset);
+  }
+
+  return pRet;
+}
+
+static void sqlite3Fts5ParseSetColset(
+  Fts5Parse *pParse, 
+  Fts5ExprNearset *pNear, 
+  Fts5Colset *pColset 
+){
+  if( pParse->pConfig->eDetail==FTS5_DETAIL_NONE ){
+    pParse->rc = SQLITE_ERROR;
+    pParse->zErr = sqlite3_mprintf(
+      "fts5: column queries are not supported (detail=none)"
+    );
+    sqlite3_free(pColset);
+    return;
+  }
+
+  if( pNear ){
+    pNear->pColset = pColset;
+  }else{
+    sqlite3_free(pColset);
+  }
+}
+
+static void fts5ExprAssignXNext(Fts5ExprNode *pNode){
+  switch( pNode->eType ){
+    case FTS5_STRING: {
+      Fts5ExprNearset *pNear = pNode->pNear;
+      if( pNear->nPhrase==1 && pNear->apPhrase[0]->nTerm==1 
+       && pNear->apPhrase[0]->aTerm[0].pSynonym==0
+      ){
+        pNode->eType = FTS5_TERM;
+        pNode->xNext = fts5ExprNodeNext_TERM;
+      }else{
+        pNode->xNext = fts5ExprNodeNext_STRING;
+      }
+      break;
+    };
+
+    case FTS5_OR: {
+      pNode->xNext = fts5ExprNodeNext_OR;
+      break;
+    };
+
+    case FTS5_AND: {
+      pNode->xNext = fts5ExprNodeNext_AND;
+      break;
+    };
+
+    default: assert( pNode->eType==FTS5_NOT ); {
+      pNode->xNext = fts5ExprNodeNext_NOT;
+      break;
+    };
+  }
+}
+
+static void fts5ExprAddChildren(Fts5ExprNode *p, Fts5ExprNode *pSub){
+  if( p->eType!=FTS5_NOT && pSub->eType==p->eType ){
+    int nByte = sizeof(Fts5ExprNode*) * pSub->nChild;
+    memcpy(&p->apChild[p->nChild], pSub->apChild, nByte);
+    p->nChild += pSub->nChild;
+    sqlite3_free(pSub);
+  }else{
+    p->apChild[p->nChild++] = pSub;
+  }
+}
+
+/*
+** Allocate and return a new expression object. If anything goes wrong (i.e.
+** OOM error), leave an error code in pParse and return NULL.
+*/
+static Fts5ExprNode *sqlite3Fts5ParseNode(
+  Fts5Parse *pParse,              /* Parse context */
+  int eType,                      /* FTS5_STRING, AND, OR or NOT */
+  Fts5ExprNode *pLeft,            /* Left hand child expression */
+  Fts5ExprNode *pRight,           /* Right hand child expression */
+  Fts5ExprNearset *pNear          /* For STRING expressions, the near cluster */
+){
+  Fts5ExprNode *pRet = 0;
+
+  if( pParse->rc==SQLITE_OK ){
+    int nChild = 0;               /* Number of children of returned node */
+    int nByte;                    /* Bytes of space to allocate for this node */
+ 
+    assert( (eType!=FTS5_STRING && !pNear)
+         || (eType==FTS5_STRING && !pLeft && !pRight)
+    );
+    if( eType==FTS5_STRING && pNear==0 ) return 0;
+    if( eType!=FTS5_STRING && pLeft==0 ) return pRight;
+    if( eType!=FTS5_STRING && pRight==0 ) return pLeft;
+
+    if( eType==FTS5_NOT ){
+      nChild = 2;
+    }else if( eType==FTS5_AND || eType==FTS5_OR ){
+      nChild = 2;
+      if( pLeft->eType==eType ) nChild += pLeft->nChild-1;
+      if( pRight->eType==eType ) nChild += pRight->nChild-1;
+    }
+
+    nByte = sizeof(Fts5ExprNode) + sizeof(Fts5ExprNode*)*(nChild-1);
+    pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);
+
+    if( pRet ){
+      pRet->eType = eType;
+      pRet->pNear = pNear;
+      fts5ExprAssignXNext(pRet);
+      if( eType==FTS5_STRING ){
+        int iPhrase;
+        for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){
+          pNear->apPhrase[iPhrase]->pNode = pRet;
+          if( pNear->apPhrase[iPhrase]->nTerm==0 ){
+            pRet->xNext = 0;
+            pRet->eType = FTS5_EOF;
+          }
+        }
+
+        if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL 
+         && (pNear->nPhrase!=1 || pNear->apPhrase[0]->nTerm>1)
+        ){
+          assert( pParse->rc==SQLITE_OK );
+          pParse->rc = SQLITE_ERROR;
+          assert( pParse->zErr==0 );
+          pParse->zErr = sqlite3_mprintf(
+              "fts5: %s queries are not supported (detail!=full)", 
+              pNear->nPhrase==1 ? "phrase": "NEAR"
+          );
+          sqlite3_free(pRet);
+          pRet = 0;
+        }
+
+      }else{
+        fts5ExprAddChildren(pRet, pLeft);
+        fts5ExprAddChildren(pRet, pRight);
+      }
+    }
+  }
+
+  if( pRet==0 ){
+    assert( pParse->rc!=SQLITE_OK );
+    sqlite3Fts5ParseNodeFree(pLeft);
+    sqlite3Fts5ParseNodeFree(pRight);
+    sqlite3Fts5ParseNearsetFree(pNear);
+  }
+  return pRet;
+}
+
+static Fts5ExprNode *sqlite3Fts5ParseImplicitAnd(
+  Fts5Parse *pParse,              /* Parse context */
+  Fts5ExprNode *pLeft,            /* Left hand child expression */
+  Fts5ExprNode *pRight            /* Right hand child expression */
+){
+  Fts5ExprNode *pRet = 0;
+  Fts5ExprNode *pPrev;
+
+  if( pParse->rc ){
+    sqlite3Fts5ParseNodeFree(pLeft);
+    sqlite3Fts5ParseNodeFree(pRight);
+  }else{
+
+    assert( pLeft->eType==FTS5_STRING 
+        || pLeft->eType==FTS5_TERM
+        || pLeft->eType==FTS5_EOF
+        || pLeft->eType==FTS5_AND
+    );
+    assert( pRight->eType==FTS5_STRING 
+        || pRight->eType==FTS5_TERM 
+        || pRight->eType==FTS5_EOF 
+    );
+
+    if( pLeft->eType==FTS5_AND ){
+      pPrev = pLeft->apChild[pLeft->nChild-1];
+    }else{
+      pPrev = pLeft;
+    }
+    assert( pPrev->eType==FTS5_STRING 
+        || pPrev->eType==FTS5_TERM 
+        || pPrev->eType==FTS5_EOF 
+        );
+
+    if( pRight->eType==FTS5_EOF ){
+      assert( pParse->apPhrase[pParse->nPhrase-1]==pRight->pNear->apPhrase[0] );
+      sqlite3Fts5ParseNodeFree(pRight);
+      pRet = pLeft;
+      pParse->nPhrase--;
+    }
+    else if( pPrev->eType==FTS5_EOF ){
+      Fts5ExprPhrase **ap;
+
+      if( pPrev==pLeft ){
+        pRet = pRight;
+      }else{
+        pLeft->apChild[pLeft->nChild-1] = pRight;
+        pRet = pLeft;
+      }
+
+      ap = &pParse->apPhrase[pParse->nPhrase-1-pRight->pNear->nPhrase];
+      assert( ap[0]==pPrev->pNear->apPhrase[0] );
+      memmove(ap, &ap[1], sizeof(Fts5ExprPhrase*)*pRight->pNear->nPhrase);
+      pParse->nPhrase--;
+
+      sqlite3Fts5ParseNodeFree(pPrev);
+    }
+    else{
+      pRet = sqlite3Fts5ParseNode(pParse, FTS5_AND, pLeft, pRight, 0);
+    }
+  }
+
+  return pRet;
+}
+
+static char *fts5ExprTermPrint(Fts5ExprTerm *pTerm){
+  int nByte = 0;
+  Fts5ExprTerm *p;
+  char *zQuoted;
+
+  /* Determine the maximum amount of space required. */
+  for(p=pTerm; p; p=p->pSynonym){
+    nByte += (int)strlen(pTerm->zTerm) * 2 + 3 + 2;
+  }
+  zQuoted = sqlite3_malloc(nByte);
+
+  if( zQuoted ){
+    int i = 0;
+    for(p=pTerm; p; p=p->pSynonym){
+      char *zIn = p->zTerm;
+      zQuoted[i++] = '"';
+      while( *zIn ){
+        if( *zIn=='"' ) zQuoted[i++] = '"';
+        zQuoted[i++] = *zIn++;
+      }
+      zQuoted[i++] = '"';
+      if( p->pSynonym ) zQuoted[i++] = '|';
+    }
+    if( pTerm->bPrefix ){
+      zQuoted[i++] = ' ';
+      zQuoted[i++] = '*';
+    }
+    zQuoted[i++] = '\0';
+  }
+  return zQuoted;
+}
+
+static char *fts5PrintfAppend(char *zApp, const char *zFmt, ...){
+  char *zNew;
+  va_list ap;
+  va_start(ap, zFmt);
+  zNew = sqlite3_vmprintf(zFmt, ap);
+  va_end(ap);
+  if( zApp && zNew ){
+    char *zNew2 = sqlite3_mprintf("%s%s", zApp, zNew);
+    sqlite3_free(zNew);
+    zNew = zNew2;
+  }
+  sqlite3_free(zApp);
+  return zNew;
+}
+
+/*
+** Compose a tcl-readable representation of expression pExpr. Return a 
+** pointer to a buffer containing that representation. It is the 
+** responsibility of the caller to at some point free the buffer using 
+** sqlite3_free().
+*/
+static char *fts5ExprPrintTcl(
+  Fts5Config *pConfig, 
+  const char *zNearsetCmd,
+  Fts5ExprNode *pExpr
+){
+  char *zRet = 0;
+  if( pExpr->eType==FTS5_STRING || pExpr->eType==FTS5_TERM ){
+    Fts5ExprNearset *pNear = pExpr->pNear;
+    int i; 
+    int iTerm;
+
+    zRet = fts5PrintfAppend(zRet, "%s ", zNearsetCmd);
+    if( zRet==0 ) return 0;
+    if( pNear->pColset ){
+      int *aiCol = pNear->pColset->aiCol;
+      int nCol = pNear->pColset->nCol;
+      if( nCol==1 ){
+        zRet = fts5PrintfAppend(zRet, "-col %d ", aiCol[0]);
+      }else{
+        zRet = fts5PrintfAppend(zRet, "-col {%d", aiCol[0]);
+        for(i=1; i<pNear->pColset->nCol; i++){
+          zRet = fts5PrintfAppend(zRet, " %d", aiCol[i]);
+        }
+        zRet = fts5PrintfAppend(zRet, "} ");
+      }
+      if( zRet==0 ) return 0;
+    }
+
+    if( pNear->nPhrase>1 ){
+      zRet = fts5PrintfAppend(zRet, "-near %d ", pNear->nNear);
+      if( zRet==0 ) return 0;
+    }
+
+    zRet = fts5PrintfAppend(zRet, "--");
+    if( zRet==0 ) return 0;
+
+    for(i=0; i<pNear->nPhrase; i++){
+      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+
+      zRet = fts5PrintfAppend(zRet, " {");
+      for(iTerm=0; zRet && iTerm<pPhrase->nTerm; iTerm++){
+        char *zTerm = pPhrase->aTerm[iTerm].zTerm;
+        zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" ", zTerm);
+        if( pPhrase->aTerm[iTerm].bPrefix ){
+          zRet = fts5PrintfAppend(zRet, "*");
+        }
+      }
+
+      if( zRet ) zRet = fts5PrintfAppend(zRet, "}");
+      if( zRet==0 ) return 0;
+    }
+
+  }else{
+    char const *zOp = 0;
+    int i;
+    switch( pExpr->eType ){
+      case FTS5_AND: zOp = "AND"; break;
+      case FTS5_NOT: zOp = "NOT"; break;
+      default: 
+        assert( pExpr->eType==FTS5_OR );
+        zOp = "OR"; 
+        break;
+    }
+
+    zRet = sqlite3_mprintf("%s", zOp);
+    for(i=0; zRet && i<pExpr->nChild; i++){
+      char *z = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->apChild[i]);
+      if( !z ){
+        sqlite3_free(zRet);
+        zRet = 0;
+      }else{
+        zRet = fts5PrintfAppend(zRet, " [%z]", z);
+      }
+    }
+  }
+
+  return zRet;
+}
+
+static char *fts5ExprPrint(Fts5Config *pConfig, Fts5ExprNode *pExpr){
+  char *zRet = 0;
+  if( pExpr->eType==0 ){
+    return sqlite3_mprintf("\"\"");
+  }else
+  if( pExpr->eType==FTS5_STRING || pExpr->eType==FTS5_TERM ){
+    Fts5ExprNearset *pNear = pExpr->pNear;
+    int i; 
+    int iTerm;
+
+    if( pNear->pColset ){
+      int iCol = pNear->pColset->aiCol[0];
+      zRet = fts5PrintfAppend(zRet, "%s : ", pConfig->azCol[iCol]);
+      if( zRet==0 ) return 0;
+    }
+
+    if( pNear->nPhrase>1 ){
+      zRet = fts5PrintfAppend(zRet, "NEAR(");
+      if( zRet==0 ) return 0;
+    }
+
+    for(i=0; i<pNear->nPhrase; i++){
+      Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
+      if( i!=0 ){
+        zRet = fts5PrintfAppend(zRet, " ");
+        if( zRet==0 ) return 0;
+      }
+      for(iTerm=0; iTerm<pPhrase->nTerm; iTerm++){
+        char *zTerm = fts5ExprTermPrint(&pPhrase->aTerm[iTerm]);
+        if( zTerm ){
+          zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" + ", zTerm);
+          sqlite3_free(zTerm);
+        }
+        if( zTerm==0 || zRet==0 ){
+          sqlite3_free(zRet);
+          return 0;
+        }
+      }
+    }
+
+    if( pNear->nPhrase>1 ){
+      zRet = fts5PrintfAppend(zRet, ", %d)", pNear->nNear);
+      if( zRet==0 ) return 0;
+    }
+
+  }else{
+    char const *zOp = 0;
+    int i;
+
+    switch( pExpr->eType ){
+      case FTS5_AND: zOp = " AND "; break;
+      case FTS5_NOT: zOp = " NOT "; break;
+      default:  
+        assert( pExpr->eType==FTS5_OR );
+        zOp = " OR "; 
+        break;
+    }
+
+    for(i=0; i<pExpr->nChild; i++){
+      char *z = fts5ExprPrint(pConfig, pExpr->apChild[i]);
+      if( z==0 ){
+        sqlite3_free(zRet);
+        zRet = 0;
+      }else{
+        int e = pExpr->apChild[i]->eType;
+        int b = (e!=FTS5_STRING && e!=FTS5_TERM && e!=FTS5_EOF);
+        zRet = fts5PrintfAppend(zRet, "%s%s%z%s", 
+            (i==0 ? "" : zOp),
+            (b?"(":""), z, (b?")":"")
+        );
+      }
+      if( zRet==0 ) break;
+    }
+  }
+
+  return zRet;
+}
+
+/*
+** The implementation of user-defined scalar functions fts5_expr() (bTcl==0)
+** and fts5_expr_tcl() (bTcl!=0).
+*/
+static void fts5ExprFunction(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apVal,          /* Function arguments */
+  int bTcl
+){
+  Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);
+  sqlite3 *db = sqlite3_context_db_handle(pCtx);
+  const char *zExpr = 0;
+  char *zErr = 0;
+  Fts5Expr *pExpr = 0;
+  int rc;
+  int i;
+
+  const char **azConfig;          /* Array of arguments for Fts5Config */
+  const char *zNearsetCmd = "nearset";
+  int nConfig;                    /* Size of azConfig[] */
+  Fts5Config *pConfig = 0;
+  int iArg = 1;
+
+  if( nArg<1 ){
+    zErr = sqlite3_mprintf("wrong number of arguments to function %s",
+        bTcl ? "fts5_expr_tcl" : "fts5_expr"
+    );
+    sqlite3_result_error(pCtx, zErr, -1);
+    sqlite3_free(zErr);
+    return;
+  }
+
+  if( bTcl && nArg>1 ){
+    zNearsetCmd = (const char*)sqlite3_value_text(apVal[1]);
+    iArg = 2;
+  }
+
+  nConfig = 3 + (nArg-iArg);
+  azConfig = (const char**)sqlite3_malloc(sizeof(char*) * nConfig);
+  if( azConfig==0 ){
+    sqlite3_result_error_nomem(pCtx);
+    return;
+  }
+  azConfig[0] = 0;
+  azConfig[1] = "main";
+  azConfig[2] = "tbl";
+  for(i=3; iArg<nArg; iArg++){
+    azConfig[i++] = (const char*)sqlite3_value_text(apVal[iArg]);
+  }
+
+  zExpr = (const char*)sqlite3_value_text(apVal[0]);
+
+  rc = sqlite3Fts5ConfigParse(pGlobal, db, nConfig, azConfig, &pConfig, &zErr);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5ExprNew(pConfig, zExpr, &pExpr, &zErr);
+  }
+  if( rc==SQLITE_OK ){
+    char *zText;
+    if( pExpr->pRoot->xNext==0 ){
+      zText = sqlite3_mprintf("");
+    }else if( bTcl ){
+      zText = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pRoot);
+    }else{
+      zText = fts5ExprPrint(pConfig, pExpr->pRoot);
+    }
+    if( zText==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      sqlite3_result_text(pCtx, zText, -1, SQLITE_TRANSIENT);
+      sqlite3_free(zText);
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    if( zErr ){
+      sqlite3_result_error(pCtx, zErr, -1);
+      sqlite3_free(zErr);
+    }else{
+      sqlite3_result_error_code(pCtx, rc);
+    }
+  }
+  sqlite3_free((void *)azConfig);
+  sqlite3Fts5ConfigFree(pConfig);
+  sqlite3Fts5ExprFree(pExpr);
+}
+
+static void fts5ExprFunctionHr(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  fts5ExprFunction(pCtx, nArg, apVal, 0);
+}
+static void fts5ExprFunctionTcl(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  fts5ExprFunction(pCtx, nArg, apVal, 1);
+}
+
+/*
+** The implementation of an SQLite user-defined-function that accepts a
+** single integer as an argument. If the integer is an alpha-numeric 
+** unicode code point, 1 is returned. Otherwise 0.
+*/
+static void fts5ExprIsAlnum(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  int iCode;
+  if( nArg!=1 ){
+    sqlite3_result_error(pCtx, 
+        "wrong number of arguments to function fts5_isalnum", -1
+    );
+    return;
+  }
+  iCode = sqlite3_value_int(apVal[0]);
+  sqlite3_result_int(pCtx, sqlite3Fts5UnicodeIsalnum(iCode));
+}
+
+static void fts5ExprFold(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  if( nArg!=1 && nArg!=2 ){
+    sqlite3_result_error(pCtx, 
+        "wrong number of arguments to function fts5_fold", -1
+    );
+  }else{
+    int iCode;
+    int bRemoveDiacritics = 0;
+    iCode = sqlite3_value_int(apVal[0]);
+    if( nArg==2 ) bRemoveDiacritics = sqlite3_value_int(apVal[1]);
+    sqlite3_result_int(pCtx, sqlite3Fts5UnicodeFold(iCode, bRemoveDiacritics));
+  }
+}
+
+/*
+** This is called during initialization to register the fts5_expr() scalar
+** UDF with the SQLite handle passed as the only argument.
+*/
+static int sqlite3Fts5ExprInit(Fts5Global *pGlobal, sqlite3 *db){
+  struct Fts5ExprFunc {
+    const char *z;
+    void (*x)(sqlite3_context*,int,sqlite3_value**);
+  } aFunc[] = {
+    { "fts5_expr",     fts5ExprFunctionHr },
+    { "fts5_expr_tcl", fts5ExprFunctionTcl },
+    { "fts5_isalnum",  fts5ExprIsAlnum },
+    { "fts5_fold",     fts5ExprFold },
+  };
+  int i;
+  int rc = SQLITE_OK;
+  void *pCtx = (void*)pGlobal;
+
+  for(i=0; rc==SQLITE_OK && i<ArraySize(aFunc); i++){
+    struct Fts5ExprFunc *p = &aFunc[i];
+    rc = sqlite3_create_function(db, p->z, -1, SQLITE_UTF8, pCtx, p->x, 0, 0);
+  }
+
+  /* Avoid a warning indicating that sqlite3Fts5ParserTrace() is unused */
+#ifndef NDEBUG
+  (void)sqlite3Fts5ParserTrace;
+#endif
+
+  return rc;
+}
+
+/*
+** Return the number of phrases in expression pExpr.
+*/
+static int sqlite3Fts5ExprPhraseCount(Fts5Expr *pExpr){
+  return (pExpr ? pExpr->nPhrase : 0);
+}
+
+/*
+** Return the number of terms in the iPhrase'th phrase in pExpr.
+*/
+static int sqlite3Fts5ExprPhraseSize(Fts5Expr *pExpr, int iPhrase){
+  if( iPhrase<0 || iPhrase>=pExpr->nPhrase ) return 0;
+  return pExpr->apExprPhrase[iPhrase]->nTerm;
+}
+
+/*
+** This function is used to access the current position list for phrase
+** iPhrase.
+*/
+static int sqlite3Fts5ExprPoslist(Fts5Expr *pExpr, int iPhrase, const u8 **pa){
+  int nRet;
+  Fts5ExprPhrase *pPhrase = pExpr->apExprPhrase[iPhrase];
+  Fts5ExprNode *pNode = pPhrase->pNode;
+  if( pNode->bEof==0 && pNode->iRowid==pExpr->pRoot->iRowid ){
+    *pa = pPhrase->poslist.p;
+    nRet = pPhrase->poslist.n;
+  }else{
+    *pa = 0;
+    nRet = 0;
+  }
+  return nRet;
+}
+
+struct Fts5PoslistPopulator {
+  Fts5PoslistWriter writer;
+  int bOk;                        /* True if ok to populate */
+  int bMiss;
+};
+
+static Fts5PoslistPopulator *sqlite3Fts5ExprClearPoslists(Fts5Expr *pExpr, int bLive){
+  Fts5PoslistPopulator *pRet;
+  pRet = sqlite3_malloc(sizeof(Fts5PoslistPopulator)*pExpr->nPhrase);
+  if( pRet ){
+    int i;
+    memset(pRet, 0, sizeof(Fts5PoslistPopulator)*pExpr->nPhrase);
+    for(i=0; i<pExpr->nPhrase; i++){
+      Fts5Buffer *pBuf = &pExpr->apExprPhrase[i]->poslist;
+      Fts5ExprNode *pNode = pExpr->apExprPhrase[i]->pNode;
+      assert( pExpr->apExprPhrase[i]->nTerm==1 );
+      if( bLive && 
+          (pBuf->n==0 || pNode->iRowid!=pExpr->pRoot->iRowid || pNode->bEof)
+      ){
+        pRet[i].bMiss = 1;
+      }else{
+        pBuf->n = 0;
+      }
+    }
+  }
+  return pRet;
+}
+
+struct Fts5ExprCtx {
+  Fts5Expr *pExpr;
+  Fts5PoslistPopulator *aPopulator;
+  i64 iOff;
+};
+typedef struct Fts5ExprCtx Fts5ExprCtx;
+
+/*
+** TODO: Make this more efficient!
+*/
+static int fts5ExprColsetTest(Fts5Colset *pColset, int iCol){
+  int i;
+  for(i=0; i<pColset->nCol; i++){
+    if( pColset->aiCol[i]==iCol ) return 1;
+  }
+  return 0;
+}
+
+static int fts5ExprPopulatePoslistsCb(
+  void *pCtx,                /* Copy of 2nd argument to xTokenize() */
+  int tflags,                /* Mask of FTS5_TOKEN_* flags */
+  const char *pToken,        /* Pointer to buffer containing token */
+  int nToken,                /* Size of token in bytes */
+  int iUnused1,              /* Byte offset of token within input text */
+  int iUnused2               /* Byte offset of end of token within input text */
+){
+  Fts5ExprCtx *p = (Fts5ExprCtx*)pCtx;
+  Fts5Expr *pExpr = p->pExpr;
+  int i;
+
+  UNUSED_PARAM2(iUnused1, iUnused2);
+
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
+  if( (tflags & FTS5_TOKEN_COLOCATED)==0 ) p->iOff++;
+  for(i=0; i<pExpr->nPhrase; i++){
+    Fts5ExprTerm *pTerm;
+    if( p->aPopulator[i].bOk==0 ) continue;
+    for(pTerm=&pExpr->apExprPhrase[i]->aTerm[0]; pTerm; pTerm=pTerm->pSynonym){
+      int nTerm = (int)strlen(pTerm->zTerm);
+      if( (nTerm==nToken || (nTerm<nToken && pTerm->bPrefix))
+       && memcmp(pTerm->zTerm, pToken, nTerm)==0
+      ){
+        int rc = sqlite3Fts5PoslistWriterAppend(
+            &pExpr->apExprPhrase[i]->poslist, &p->aPopulator[i].writer, p->iOff
+        );
+        if( rc ) return rc;
+        break;
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+
+static int sqlite3Fts5ExprPopulatePoslists(
+  Fts5Config *pConfig,
+  Fts5Expr *pExpr, 
+  Fts5PoslistPopulator *aPopulator,
+  int iCol, 
+  const char *z, int n
+){
+  int i;
+  Fts5ExprCtx sCtx;
+  sCtx.pExpr = pExpr;
+  sCtx.aPopulator = aPopulator;
+  sCtx.iOff = (((i64)iCol) << 32) - 1;
+
+  for(i=0; i<pExpr->nPhrase; i++){
+    Fts5ExprNode *pNode = pExpr->apExprPhrase[i]->pNode;
+    Fts5Colset *pColset = pNode->pNear->pColset;
+    if( (pColset && 0==fts5ExprColsetTest(pColset, iCol)) 
+     || aPopulator[i].bMiss
+    ){
+      aPopulator[i].bOk = 0;
+    }else{
+      aPopulator[i].bOk = 1;
+    }
+  }
+
+  return sqlite3Fts5Tokenize(pConfig, 
+      FTS5_TOKENIZE_DOCUMENT, z, n, (void*)&sCtx, fts5ExprPopulatePoslistsCb
+  );
+}
+
+static void fts5ExprClearPoslists(Fts5ExprNode *pNode){
+  if( pNode->eType==FTS5_TERM || pNode->eType==FTS5_STRING ){
+    pNode->pNear->apPhrase[0]->poslist.n = 0;
+  }else{
+    int i;
+    for(i=0; i<pNode->nChild; i++){
+      fts5ExprClearPoslists(pNode->apChild[i]);
+    }
+  }
+}
+
+static int fts5ExprCheckPoslists(Fts5ExprNode *pNode, i64 iRowid){
+  pNode->iRowid = iRowid;
+  pNode->bEof = 0;
+  switch( pNode->eType ){
+    case FTS5_TERM:
+    case FTS5_STRING:
+      return (pNode->pNear->apPhrase[0]->poslist.n>0);
+
+    case FTS5_AND: {
+      int i;
+      for(i=0; i<pNode->nChild; i++){
+        if( fts5ExprCheckPoslists(pNode->apChild[i], iRowid)==0 ){
+          fts5ExprClearPoslists(pNode);
+          return 0;
+        }
+      }
+      break;
+    }
+
+    case FTS5_OR: {
+      int i;
+      int bRet = 0;
+      for(i=0; i<pNode->nChild; i++){
+        if( fts5ExprCheckPoslists(pNode->apChild[i], iRowid) ){
+          bRet = 1;
+        }
+      }
+      return bRet;
+    }
+
+    default: {
+      assert( pNode->eType==FTS5_NOT );
+      if( 0==fts5ExprCheckPoslists(pNode->apChild[0], iRowid)
+          || 0!=fts5ExprCheckPoslists(pNode->apChild[1], iRowid)
+        ){
+        fts5ExprClearPoslists(pNode);
+        return 0;
+      }
+      break;
+    }
+  }
+  return 1;
+}
+
+static void sqlite3Fts5ExprCheckPoslists(Fts5Expr *pExpr, i64 iRowid){
+  fts5ExprCheckPoslists(pExpr->pRoot, iRowid);
+}
+
+/*
+** This function is only called for detail=columns tables. 
+*/
+static int sqlite3Fts5ExprPhraseCollist(
+  Fts5Expr *pExpr, 
+  int iPhrase, 
+  const u8 **ppCollist, 
+  int *pnCollist
+){
+  Fts5ExprPhrase *pPhrase = pExpr->apExprPhrase[iPhrase];
+  Fts5ExprNode *pNode = pPhrase->pNode;
+  int rc = SQLITE_OK;
+
+  assert( iPhrase>=0 && iPhrase<pExpr->nPhrase );
+  assert( pExpr->pConfig->eDetail==FTS5_DETAIL_COLUMNS );
+
+  if( pNode->bEof==0 
+   && pNode->iRowid==pExpr->pRoot->iRowid 
+   && pPhrase->poslist.n>0
+  ){
+    Fts5ExprTerm *pTerm = &pPhrase->aTerm[0];
+    if( pTerm->pSynonym ){
+      Fts5Buffer *pBuf = (Fts5Buffer*)&pTerm->pSynonym[1];
+      rc = fts5ExprSynonymList(
+          pTerm, pNode->iRowid, pBuf, (u8**)ppCollist, pnCollist
+      );
+    }else{
+      *ppCollist = pPhrase->aTerm[0].pIter->pData;
+      *pnCollist = pPhrase->aTerm[0].pIter->nData;
+    }
+  }else{
+    *ppCollist = 0;
+    *pnCollist = 0;
+  }
+
+  return rc;
+}
+
+
+/*
+** 2014 August 11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+
+
+
+/* #include "fts5Int.h" */
+
+typedef struct Fts5HashEntry Fts5HashEntry;
+
+/*
+** This file contains the implementation of an in-memory hash table used
+** to accumuluate "term -> doclist" content before it is flused to a level-0
+** segment.
+*/
+
+
+struct Fts5Hash {
+  int eDetail;                    /* Copy of Fts5Config.eDetail */
+  int *pnByte;                    /* Pointer to bytes counter */
+  int nEntry;                     /* Number of entries currently in hash */
+  int nSlot;                      /* Size of aSlot[] array */
+  Fts5HashEntry *pScan;           /* Current ordered scan item */
+  Fts5HashEntry **aSlot;          /* Array of hash slots */
+};
+
+/*
+** Each entry in the hash table is represented by an object of the 
+** following type. Each object, its key (zKey[]) and its current data
+** are stored in a single memory allocation. The position list data 
+** immediately follows the key data in memory.
+**
+** The data that follows the key is in a similar, but not identical format
+** to the doclist data stored in the database. It is:
+**
+**   * Rowid, as a varint
+**   * Position list, without 0x00 terminator.
+**   * Size of previous position list and rowid, as a 4 byte
+**     big-endian integer.
+**
+** iRowidOff:
+**   Offset of last rowid written to data area. Relative to first byte of
+**   structure.
+**
+** nData:
+**   Bytes of data written since iRowidOff.
+*/
+struct Fts5HashEntry {
+  Fts5HashEntry *pHashNext;       /* Next hash entry with same hash-key */
+  Fts5HashEntry *pScanNext;       /* Next entry in sorted order */
+  
+  int nAlloc;                     /* Total size of allocation */
+  int iSzPoslist;                 /* Offset of space for 4-byte poslist size */
+  int nData;                      /* Total bytes of data (incl. structure) */
+  int nKey;                       /* Length of zKey[] in bytes */
+  u8 bDel;                        /* Set delete-flag @ iSzPoslist */
+  u8 bContent;                    /* Set content-flag (detail=none mode) */
+  i16 iCol;                       /* Column of last value written */
+  int iPos;                       /* Position of last value written */
+  i64 iRowid;                     /* Rowid of last value written */
+  char zKey[8];                   /* Nul-terminated entry key */
+};
+
+/*
+** Size of Fts5HashEntry without the zKey[] array.
+*/
+#define FTS5_HASHENTRYSIZE (sizeof(Fts5HashEntry)-8)
+
+
+
+/*
+** Allocate a new hash table.
+*/
+static int sqlite3Fts5HashNew(Fts5Config *pConfig, Fts5Hash **ppNew, int *pnByte){
+  int rc = SQLITE_OK;
+  Fts5Hash *pNew;
+
+  *ppNew = pNew = (Fts5Hash*)sqlite3_malloc(sizeof(Fts5Hash));
+  if( pNew==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    int nByte;
+    memset(pNew, 0, sizeof(Fts5Hash));
+    pNew->pnByte = pnByte;
+    pNew->eDetail = pConfig->eDetail;
+
+    pNew->nSlot = 1024;
+    nByte = sizeof(Fts5HashEntry*) * pNew->nSlot;
+    pNew->aSlot = (Fts5HashEntry**)sqlite3_malloc(nByte);
+    if( pNew->aSlot==0 ){
+      sqlite3_free(pNew);
+      *ppNew = 0;
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pNew->aSlot, 0, nByte);
+    }
+  }
+  return rc;
+}
+
+/*
+** Free a hash table object.
+*/
+static void sqlite3Fts5HashFree(Fts5Hash *pHash){
+  if( pHash ){
+    sqlite3Fts5HashClear(pHash);
+    sqlite3_free(pHash->aSlot);
+    sqlite3_free(pHash);
+  }
+}
+
+/*
+** Empty (but do not delete) a hash table.
+*/
+static void sqlite3Fts5HashClear(Fts5Hash *pHash){
+  int i;
+  for(i=0; i<pHash->nSlot; i++){
+    Fts5HashEntry *pNext;
+    Fts5HashEntry *pSlot;
+    for(pSlot=pHash->aSlot[i]; pSlot; pSlot=pNext){
+      pNext = pSlot->pHashNext;
+      sqlite3_free(pSlot);
+    }
+  }
+  memset(pHash->aSlot, 0, pHash->nSlot * sizeof(Fts5HashEntry*));
+  pHash->nEntry = 0;
+}
+
+static unsigned int fts5HashKey(int nSlot, const u8 *p, int n){
+  int i;
+  unsigned int h = 13;
+  for(i=n-1; i>=0; i--){
+    h = (h << 3) ^ h ^ p[i];
+  }
+  return (h % nSlot);
+}
+
+static unsigned int fts5HashKey2(int nSlot, u8 b, const u8 *p, int n){
+  int i;
+  unsigned int h = 13;
+  for(i=n-1; i>=0; i--){
+    h = (h << 3) ^ h ^ p[i];
+  }
+  h = (h << 3) ^ h ^ b;
+  return (h % nSlot);
+}
+
+/*
+** Resize the hash table by doubling the number of slots.
+*/
+static int fts5HashResize(Fts5Hash *pHash){
+  int nNew = pHash->nSlot*2;
+  int i;
+  Fts5HashEntry **apNew;
+  Fts5HashEntry **apOld = pHash->aSlot;
+
+  apNew = (Fts5HashEntry**)sqlite3_malloc(nNew*sizeof(Fts5HashEntry*));
+  if( !apNew ) return SQLITE_NOMEM;
+  memset(apNew, 0, nNew*sizeof(Fts5HashEntry*));
+
+  for(i=0; i<pHash->nSlot; i++){
+    while( apOld[i] ){
+      int iHash;
+      Fts5HashEntry *p = apOld[i];
+      apOld[i] = p->pHashNext;
+      iHash = fts5HashKey(nNew, (u8*)p->zKey, (int)strlen(p->zKey));
+      p->pHashNext = apNew[iHash];
+      apNew[iHash] = p;
+    }
+  }
+
+  sqlite3_free(apOld);
+  pHash->nSlot = nNew;
+  pHash->aSlot = apNew;
+  return SQLITE_OK;
+}
+
+static void fts5HashAddPoslistSize(Fts5Hash *pHash, Fts5HashEntry *p){
+  if( p->iSzPoslist ){
+    u8 *pPtr = (u8*)p;
+    if( pHash->eDetail==FTS5_DETAIL_NONE ){
+      assert( p->nData==p->iSzPoslist );
+      if( p->bDel ){
+        pPtr[p->nData++] = 0x00;
+        if( p->bContent ){
+          pPtr[p->nData++] = 0x00;
+        }
+      }
+    }else{
+      int nSz = (p->nData - p->iSzPoslist - 1);       /* Size in bytes */
+      int nPos = nSz*2 + p->bDel;                     /* Value of nPos field */
+
+      assert( p->bDel==0 || p->bDel==1 );
+      if( nPos<=127 ){
+        pPtr[p->iSzPoslist] = (u8)nPos;
+      }else{
+        int nByte = sqlite3Fts5GetVarintLen((u32)nPos);
+        memmove(&pPtr[p->iSzPoslist + nByte], &pPtr[p->iSzPoslist + 1], nSz);
+        sqlite3Fts5PutVarint(&pPtr[p->iSzPoslist], nPos);
+        p->nData += (nByte-1);
+      }
+    }
+
+    p->iSzPoslist = 0;
+    p->bDel = 0;
+    p->bContent = 0;
+  }
+}
+
+/*
+** Add an entry to the in-memory hash table. The key is the concatenation
+** of bByte and (pToken/nToken). The value is (iRowid/iCol/iPos).
+**
+**     (bByte || pToken) -> (iRowid,iCol,iPos)
+**
+** Or, if iCol is negative, then the value is a delete marker.
+*/
+static int sqlite3Fts5HashWrite(
+  Fts5Hash *pHash,
+  i64 iRowid,                     /* Rowid for this entry */
+  int iCol,                       /* Column token appears in (-ve -> delete) */
+  int iPos,                       /* Position of token within column */
+  char bByte,                     /* First byte of token */
+  const char *pToken, int nToken  /* Token to add or remove to or from index */
+){
+  unsigned int iHash;
+  Fts5HashEntry *p;
+  u8 *pPtr;
+  int nIncr = 0;                  /* Amount to increment (*pHash->pnByte) by */
+  int bNew;                       /* If non-delete entry should be written */
+  
+  bNew = (pHash->eDetail==FTS5_DETAIL_FULL);
+
+  /* Attempt to locate an existing hash entry */
+  iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);
+  for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){
+    if( p->zKey[0]==bByte 
+     && p->nKey==nToken
+     && memcmp(&p->zKey[1], pToken, nToken)==0 
+    ){
+      break;
+    }
+  }
+
+  /* If an existing hash entry cannot be found, create a new one. */
+  if( p==0 ){
+    /* Figure out how much space to allocate */
+    int nByte = FTS5_HASHENTRYSIZE + (nToken+1) + 1 + 64;
+    if( nByte<128 ) nByte = 128;
+
+    /* Grow the Fts5Hash.aSlot[] array if necessary. */
+    if( (pHash->nEntry*2)>=pHash->nSlot ){
+      int rc = fts5HashResize(pHash);
+      if( rc!=SQLITE_OK ) return rc;
+      iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);
+    }
+
+    /* Allocate new Fts5HashEntry and add it to the hash table. */
+    p = (Fts5HashEntry*)sqlite3_malloc(nByte);
+    if( !p ) return SQLITE_NOMEM;
+    memset(p, 0, FTS5_HASHENTRYSIZE);
+    p->nAlloc = nByte;
+    p->zKey[0] = bByte;
+    memcpy(&p->zKey[1], pToken, nToken);
+    assert( iHash==fts5HashKey(pHash->nSlot, (u8*)p->zKey, nToken+1) );
+    p->nKey = nToken;
+    p->zKey[nToken+1] = '\0';
+    p->nData = nToken+1 + 1 + FTS5_HASHENTRYSIZE;
+    p->pHashNext = pHash->aSlot[iHash];
+    pHash->aSlot[iHash] = p;
+    pHash->nEntry++;
+
+    /* Add the first rowid field to the hash-entry */
+    p->nData += sqlite3Fts5PutVarint(&((u8*)p)[p->nData], iRowid);
+    p->iRowid = iRowid;
+
+    p->iSzPoslist = p->nData;
+    if( pHash->eDetail!=FTS5_DETAIL_NONE ){
+      p->nData += 1;
+      p->iCol = (pHash->eDetail==FTS5_DETAIL_FULL ? 0 : -1);
+    }
+
+    nIncr += p->nData;
+  }else{
+
+    /* Appending to an existing hash-entry. Check that there is enough 
+    ** space to append the largest possible new entry. Worst case scenario 
+    ** is:
+    **
+    **     + 9 bytes for a new rowid,
+    **     + 4 byte reserved for the "poslist size" varint.
+    **     + 1 byte for a "new column" byte,
+    **     + 3 bytes for a new column number (16-bit max) as a varint,
+    **     + 5 bytes for the new position offset (32-bit max).
+    */
+    if( (p->nAlloc - p->nData) < (9 + 4 + 1 + 3 + 5) ){
+      int nNew = p->nAlloc * 2;
+      Fts5HashEntry *pNew;
+      Fts5HashEntry **pp;
+      pNew = (Fts5HashEntry*)sqlite3_realloc(p, nNew);
+      if( pNew==0 ) return SQLITE_NOMEM;
+      pNew->nAlloc = nNew;
+      for(pp=&pHash->aSlot[iHash]; *pp!=p; pp=&(*pp)->pHashNext);
+      *pp = pNew;
+      p = pNew;
+    }
+    nIncr -= p->nData;
+  }
+  assert( (p->nAlloc - p->nData) >= (9 + 4 + 1 + 3 + 5) );
+
+  pPtr = (u8*)p;
+
+  /* If this is a new rowid, append the 4-byte size field for the previous
+  ** entry, and the new rowid for this entry.  */
+  if( iRowid!=p->iRowid ){
+    fts5HashAddPoslistSize(pHash, p);
+    p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iRowid - p->iRowid);
+    p->iRowid = iRowid;
+    bNew = 1;
+    p->iSzPoslist = p->nData;
+    if( pHash->eDetail!=FTS5_DETAIL_NONE ){
+      p->nData += 1;
+      p->iCol = (pHash->eDetail==FTS5_DETAIL_FULL ? 0 : -1);
+      p->iPos = 0;
+    }
+  }
+
+  if( iCol>=0 ){
+    if( pHash->eDetail==FTS5_DETAIL_NONE ){
+      p->bContent = 1;
+    }else{
+      /* Append a new column value, if necessary */
+      assert( iCol>=p->iCol );
+      if( iCol!=p->iCol ){
+        if( pHash->eDetail==FTS5_DETAIL_FULL ){
+          pPtr[p->nData++] = 0x01;
+          p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iCol);
+          p->iCol = (i16)iCol;
+          p->iPos = 0;
+        }else{
+          bNew = 1;
+          p->iCol = (i16)(iPos = iCol);
+        }
+      }
+
+      /* Append the new position offset, if necessary */
+      if( bNew ){
+        p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iPos - p->iPos + 2);
+        p->iPos = iPos;
+      }
+    }
+  }else{
+    /* This is a delete. Set the delete flag. */
+    p->bDel = 1;
+  }
+
+  nIncr += p->nData;
+  *pHash->pnByte += nIncr;
+  return SQLITE_OK;
+}
+
+
+/*
+** Arguments pLeft and pRight point to linked-lists of hash-entry objects,
+** each sorted in key order. This function merges the two lists into a
+** single list and returns a pointer to its first element.
+*/
+static Fts5HashEntry *fts5HashEntryMerge(
+  Fts5HashEntry *pLeft,
+  Fts5HashEntry *pRight
+){
+  Fts5HashEntry *p1 = pLeft;
+  Fts5HashEntry *p2 = pRight;
+  Fts5HashEntry *pRet = 0;
+  Fts5HashEntry **ppOut = &pRet;
+
+  while( p1 || p2 ){
+    if( p1==0 ){
+      *ppOut = p2;
+      p2 = 0;
+    }else if( p2==0 ){
+      *ppOut = p1;
+      p1 = 0;
+    }else{
+      int i = 0;
+      while( p1->zKey[i]==p2->zKey[i] ) i++;
+
+      if( ((u8)p1->zKey[i])>((u8)p2->zKey[i]) ){
+        /* p2 is smaller */
+        *ppOut = p2;
+        ppOut = &p2->pScanNext;
+        p2 = p2->pScanNext;
+      }else{
+        /* p1 is smaller */
+        *ppOut = p1;
+        ppOut = &p1->pScanNext;
+        p1 = p1->pScanNext;
+      }
+      *ppOut = 0;
+    }
+  }
+
+  return pRet;
+}
+
+/*
+** Extract all tokens from hash table iHash and link them into a list
+** in sorted order. The hash table is cleared before returning. It is
+** the responsibility of the caller to free the elements of the returned
+** list.
+*/
+static int fts5HashEntrySort(
+  Fts5Hash *pHash, 
+  const char *pTerm, int nTerm,   /* Query prefix, if any */
+  Fts5HashEntry **ppSorted
+){
+  const int nMergeSlot = 32;
+  Fts5HashEntry **ap;
+  Fts5HashEntry *pList;
+  int iSlot;
+  int i;
+
+  *ppSorted = 0;
+  ap = sqlite3_malloc(sizeof(Fts5HashEntry*) * nMergeSlot);
+  if( !ap ) return SQLITE_NOMEM;
+  memset(ap, 0, sizeof(Fts5HashEntry*) * nMergeSlot);
+
+  for(iSlot=0; iSlot<pHash->nSlot; iSlot++){
+    Fts5HashEntry *pIter;
+    for(pIter=pHash->aSlot[iSlot]; pIter; pIter=pIter->pHashNext){
+      if( pTerm==0 || 0==memcmp(pIter->zKey, pTerm, nTerm) ){
+        Fts5HashEntry *pEntry = pIter;
+        pEntry->pScanNext = 0;
+        for(i=0; ap[i]; i++){
+          pEntry = fts5HashEntryMerge(pEntry, ap[i]);
+          ap[i] = 0;
+        }
+        ap[i] = pEntry;
+      }
+    }
+  }
+
+  pList = 0;
+  for(i=0; i<nMergeSlot; i++){
+    pList = fts5HashEntryMerge(pList, ap[i]);
+  }
+
+  pHash->nEntry = 0;
+  sqlite3_free(ap);
+  *ppSorted = pList;
+  return SQLITE_OK;
+}
+
+/*
+** Query the hash table for a doclist associated with term pTerm/nTerm.
+*/
+static int sqlite3Fts5HashQuery(
+  Fts5Hash *pHash,                /* Hash table to query */
+  const char *pTerm, int nTerm,   /* Query term */
+  const u8 **ppDoclist,           /* OUT: Pointer to doclist for pTerm */
+  int *pnDoclist                  /* OUT: Size of doclist in bytes */
+){
+  unsigned int iHash = fts5HashKey(pHash->nSlot, (const u8*)pTerm, nTerm);
+  Fts5HashEntry *p;
+
+  for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){
+    if( memcmp(p->zKey, pTerm, nTerm)==0 && p->zKey[nTerm]==0 ) break;
+  }
+
+  if( p ){
+    fts5HashAddPoslistSize(pHash, p);
+    *ppDoclist = (const u8*)&p->zKey[nTerm+1];
+    *pnDoclist = p->nData - (FTS5_HASHENTRYSIZE + nTerm + 1);
+  }else{
+    *ppDoclist = 0;
+    *pnDoclist = 0;
+  }
+
+  return SQLITE_OK;
+}
+
+static int sqlite3Fts5HashScanInit(
+  Fts5Hash *p,                    /* Hash table to query */
+  const char *pTerm, int nTerm    /* Query prefix */
+){
+  return fts5HashEntrySort(p, pTerm, nTerm, &p->pScan);
+}
+
+static void sqlite3Fts5HashScanNext(Fts5Hash *p){
+  assert( !sqlite3Fts5HashScanEof(p) );
+  p->pScan = p->pScan->pScanNext;
+}
+
+static int sqlite3Fts5HashScanEof(Fts5Hash *p){
+  return (p->pScan==0);
+}
+
+static void sqlite3Fts5HashScanEntry(
+  Fts5Hash *pHash,
+  const char **pzTerm,            /* OUT: term (nul-terminated) */
+  const u8 **ppDoclist,           /* OUT: pointer to doclist */
+  int *pnDoclist                  /* OUT: size of doclist in bytes */
+){
+  Fts5HashEntry *p;
+  if( (p = pHash->pScan) ){
+    int nTerm = (int)strlen(p->zKey);
+    fts5HashAddPoslistSize(pHash, p);
+    *pzTerm = p->zKey;
+    *ppDoclist = (const u8*)&p->zKey[nTerm+1];
+    *pnDoclist = p->nData - (FTS5_HASHENTRYSIZE + nTerm + 1);
+  }else{
+    *pzTerm = 0;
+    *ppDoclist = 0;
+    *pnDoclist = 0;
+  }
+}
+
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Low level access to the FTS index stored in the database file. The 
+** routines in this file file implement all read and write access to the
+** %_data table. Other parts of the system access this functionality via
+** the interface defined in fts5Int.h.
+*/
+
+
+/* #include "fts5Int.h" */
+
+/*
+** Overview:
+**
+** The %_data table contains all the FTS indexes for an FTS5 virtual table.
+** As well as the main term index, there may be up to 31 prefix indexes.
+** The format is similar to FTS3/4, except that:
+**
+**   * all segment b-tree leaf data is stored in fixed size page records 
+**     (e.g. 1000 bytes). A single doclist may span multiple pages. Care is 
+**     taken to ensure it is possible to iterate in either direction through 
+**     the entries in a doclist, or to seek to a specific entry within a 
+**     doclist, without loading it into memory.
+**
+**   * large doclists that span many pages have associated "doclist index"
+**     records that contain a copy of the first rowid on each page spanned by
+**     the doclist. This is used to speed up seek operations, and merges of
+**     large doclists with very small doclists.
+**
+**   * extra fields in the "structure record" record the state of ongoing
+**     incremental merge operations.
+**
+*/
+
+
+#define FTS5_OPT_WORK_UNIT  1000  /* Number of leaf pages per optimize step */
+#define FTS5_WORK_UNIT      64    /* Number of leaf pages in unit of work */
+
+#define FTS5_MIN_DLIDX_SIZE 4     /* Add dlidx if this many empty pages */
+
+#define FTS5_MAIN_PREFIX '0'
+
+#if FTS5_MAX_PREFIX_INDEXES > 31
+# error "FTS5_MAX_PREFIX_INDEXES is too large"
+#endif
+
+/*
+** Details:
+**
+** The %_data table managed by this module,
+**
+**     CREATE TABLE %_data(id INTEGER PRIMARY KEY, block BLOB);
+**
+** , contains the following 5 types of records. See the comments surrounding
+** the FTS5_*_ROWID macros below for a description of how %_data rowids are 
+** assigned to each fo them.
+**
+** 1. Structure Records:
+**
+**   The set of segments that make up an index - the index structure - are
+**   recorded in a single record within the %_data table. The record consists
+**   of a single 32-bit configuration cookie value followed by a list of 
+**   SQLite varints. If the FTS table features more than one index (because
+**   there are one or more prefix indexes), it is guaranteed that all share
+**   the same cookie value.
+**
+**   Immediately following the configuration cookie, the record begins with
+**   three varints:
+**
+**     + number of levels,
+**     + total number of segments on all levels,
+**     + value of write counter.
+**
+**   Then, for each level from 0 to nMax:
+**
+**     + number of input segments in ongoing merge.
+**     + total number of segments in level.
+**     + for each segment from oldest to newest:
+**         + segment id (always > 0)
+**         + first leaf page number (often 1, always greater than 0)
+**         + final leaf page number
+**
+** 2. The Averages Record:
+**
+**   A single record within the %_data table. The data is a list of varints.
+**   The first value is the number of rows in the index. Then, for each column
+**   from left to right, the total number of tokens in the column for all
+**   rows of the table.
+**
+** 3. Segment leaves:
+**
+**   TERM/DOCLIST FORMAT:
+**
+**     Most of each segment leaf is taken up by term/doclist data. The 
+**     general format of term/doclist, starting with the first term
+**     on the leaf page, is:
+**
+**         varint : size of first term
+**         blob:    first term data
+**         doclist: first doclist
+**         zero-or-more {
+**           varint:  number of bytes in common with previous term
+**           varint:  number of bytes of new term data (nNew)
+**           blob:    nNew bytes of new term data
+**           doclist: next doclist
+**         }
+**
+**     doclist format:
+**
+**         varint:  first rowid
+**         poslist: first poslist
+**         zero-or-more {
+**           varint:  rowid delta (always > 0)
+**           poslist: next poslist
+**         }
+**
+**     poslist format:
+**
+**         varint: size of poslist in bytes multiplied by 2, not including
+**                 this field. Plus 1 if this entry carries the "delete" flag.
+**         collist: collist for column 0
+**         zero-or-more {
+**           0x01 byte
+**           varint: column number (I)
+**           collist: collist for column I
+**         }
+**
+**     collist format:
+**
+**         varint: first offset + 2
+**         zero-or-more {
+**           varint: offset delta + 2
+**         }
+**
+**   PAGE FORMAT
+**
+**     Each leaf page begins with a 4-byte header containing 2 16-bit 
+**     unsigned integer fields in big-endian format. They are:
+**
+**       * The byte offset of the first rowid on the page, if it exists
+**         and occurs before the first term (otherwise 0).
+**
+**       * The byte offset of the start of the page footer. If the page
+**         footer is 0 bytes in size, then this field is the same as the
+**         size of the leaf page in bytes.
+**
+**     The page footer consists of a single varint for each term located
+**     on the page. Each varint is the byte offset of the current term
+**     within the page, delta-compressed against the previous value. In
+**     other words, the first varint in the footer is the byte offset of
+**     the first term, the second is the byte offset of the second less that
+**     of the first, and so on.
+**
+**     The term/doclist format described above is accurate if the entire
+**     term/doclist data fits on a single leaf page. If this is not the case,
+**     the format is changed in two ways:
+**
+**       + if the first rowid on a page occurs before the first term, it
+**         is stored as a literal value:
+**
+**             varint:  first rowid
+**
+**       + the first term on each page is stored in the same way as the
+**         very first term of the segment:
+**
+**             varint : size of first term
+**             blob:    first term data
+**
+** 5. Segment doclist indexes:
+**
+**   Doclist indexes are themselves b-trees, however they usually consist of
+**   a single leaf record only. The format of each doclist index leaf page 
+**   is:
+**
+**     * Flags byte. Bits are:
+**         0x01: Clear if leaf is also the root page, otherwise set.
+**
+**     * Page number of fts index leaf page. As a varint.
+**
+**     * First rowid on page indicated by previous field. As a varint.
+**
+**     * A list of varints, one for each subsequent termless page. A 
+**       positive delta if the termless page contains at least one rowid, 
+**       or an 0x00 byte otherwise.
+**
+**   Internal doclist index nodes are:
+**
+**     * Flags byte. Bits are:
+**         0x01: Clear for root page, otherwise set.
+**
+**     * Page number of first child page. As a varint.
+**
+**     * Copy of first rowid on page indicated by previous field. As a varint.
+**
+**     * A list of delta-encoded varints - the first rowid on each subsequent
+**       child page. 
+**
+*/
+
+/*
+** Rowids for the averages and structure records in the %_data table.
+*/
+#define FTS5_AVERAGES_ROWID     1    /* Rowid used for the averages record */
+#define FTS5_STRUCTURE_ROWID   10    /* The structure record */
+
+/*
+** Macros determining the rowids used by segment leaves and dlidx leaves
+** and nodes. All nodes and leaves are stored in the %_data table with large
+** positive rowids.
+**
+** Each segment has a unique non-zero 16-bit id.
+**
+** The rowid for each segment leaf is found by passing the segment id and 
+** the leaf page number to the FTS5_SEGMENT_ROWID macro. Leaves are numbered
+** sequentially starting from 1.
+*/
+#define FTS5_DATA_ID_B     16     /* Max seg id number 65535 */
+#define FTS5_DATA_DLI_B     1     /* Doclist-index flag (1 bit) */
+#define FTS5_DATA_HEIGHT_B  5     /* Max dlidx tree height of 32 */
+#define FTS5_DATA_PAGE_B   31     /* Max page number of 2147483648 */
+
+#define fts5_dri(segid, dlidx, height, pgno) (                                 \
+ ((i64)(segid)  << (FTS5_DATA_PAGE_B+FTS5_DATA_HEIGHT_B+FTS5_DATA_DLI_B)) +    \
+ ((i64)(dlidx)  << (FTS5_DATA_PAGE_B + FTS5_DATA_HEIGHT_B)) +                  \
+ ((i64)(height) << (FTS5_DATA_PAGE_B)) +                                       \
+ ((i64)(pgno))                                                                 \
+)
+
+#define FTS5_SEGMENT_ROWID(segid, pgno)       fts5_dri(segid, 0, 0, pgno)
+#define FTS5_DLIDX_ROWID(segid, height, pgno) fts5_dri(segid, 1, height, pgno)
+
+/*
+** Maximum segments permitted in a single index 
+*/
+#define FTS5_MAX_SEGMENT 2000
+
+#ifdef SQLITE_DEBUG
+static int sqlite3Fts5Corrupt() { return SQLITE_CORRUPT_VTAB; }
+#endif
+
+
+/*
+** Each time a blob is read from the %_data table, it is padded with this
+** many zero bytes. This makes it easier to decode the various record formats
+** without overreading if the records are corrupt.
+*/
+#define FTS5_DATA_ZERO_PADDING 8
+#define FTS5_DATA_PADDING 20
+
+typedef struct Fts5Data Fts5Data;
+typedef struct Fts5DlidxIter Fts5DlidxIter;
+typedef struct Fts5DlidxLvl Fts5DlidxLvl;
+typedef struct Fts5DlidxWriter Fts5DlidxWriter;
+typedef struct Fts5Iter Fts5Iter;
+typedef struct Fts5PageWriter Fts5PageWriter;
+typedef struct Fts5SegIter Fts5SegIter;
+typedef struct Fts5DoclistIter Fts5DoclistIter;
+typedef struct Fts5SegWriter Fts5SegWriter;
+typedef struct Fts5Structure Fts5Structure;
+typedef struct Fts5StructureLevel Fts5StructureLevel;
+typedef struct Fts5StructureSegment Fts5StructureSegment;
+
+struct Fts5Data {
+  u8 *p;                          /* Pointer to buffer containing record */
+  int nn;                         /* Size of record in bytes */
+  int szLeaf;                     /* Size of leaf without page-index */
+};
+
+/*
+** One object per %_data table.
+*/
+struct Fts5Index {
+  Fts5Config *pConfig;            /* Virtual table configuration */
+  char *zDataTbl;                 /* Name of %_data table */
+  int nWorkUnit;                  /* Leaf pages in a "unit" of work */
+
+  /*
+  ** Variables related to the accumulation of tokens and doclists within the
+  ** in-memory hash tables before they are flushed to disk.
+  */
+  Fts5Hash *pHash;                /* Hash table for in-memory data */
+  int nPendingData;               /* Current bytes of pending data */
+  i64 iWriteRowid;                /* Rowid for current doc being written */
+  int bDelete;                    /* Current write is a delete */
+
+  /* Error state. */
+  int rc;                         /* Current error code */
+
+  /* State used by the fts5DataXXX() functions. */
+  sqlite3_blob *pReader;          /* RO incr-blob open on %_data table */
+  sqlite3_stmt *pWriter;          /* "INSERT ... %_data VALUES(?,?)" */
+  sqlite3_stmt *pDeleter;         /* "DELETE FROM %_data ... id>=? AND id<=?" */
+  sqlite3_stmt *pIdxWriter;       /* "INSERT ... %_idx VALUES(?,?,?,?)" */
+  sqlite3_stmt *pIdxDeleter;      /* "DELETE FROM %_idx WHERE segid=? */
+  sqlite3_stmt *pIdxSelect;
+  int nRead;                      /* Total number of blocks read */
+
+  sqlite3_stmt *pDataVersion;
+  i64 iStructVersion;             /* data_version when pStruct read */
+  Fts5Structure *pStruct;         /* Current db structure (or NULL) */
+};
+
+struct Fts5DoclistIter {
+  u8 *aEof;                       /* Pointer to 1 byte past end of doclist */
+
+  /* Output variables. aPoslist==0 at EOF */
+  i64 iRowid;
+  u8 *aPoslist;
+  int nPoslist;
+  int nSize;
+};
+
+/*
+** The contents of the "structure" record for each index are represented
+** using an Fts5Structure record in memory. Which uses instances of the 
+** other Fts5StructureXXX types as components.
+*/
+struct Fts5StructureSegment {
+  int iSegid;                     /* Segment id */
+  int pgnoFirst;                  /* First leaf page number in segment */
+  int pgnoLast;                   /* Last leaf page number in segment */
+};
+struct Fts5StructureLevel {
+  int nMerge;                     /* Number of segments in incr-merge */
+  int nSeg;                       /* Total number of segments on level */
+  Fts5StructureSegment *aSeg;     /* Array of segments. aSeg[0] is oldest. */
+};
+struct Fts5Structure {
+  int nRef;                       /* Object reference count */
+  u64 nWriteCounter;              /* Total leaves written to level 0 */
+  int nSegment;                   /* Total segments in this structure */
+  int nLevel;                     /* Number of levels in this index */
+  Fts5StructureLevel aLevel[1];   /* Array of nLevel level objects */
+};
+
+/*
+** An object of type Fts5SegWriter is used to write to segments.
+*/
+struct Fts5PageWriter {
+  int pgno;                       /* Page number for this page */
+  int iPrevPgidx;                 /* Previous value written into pgidx */
+  Fts5Buffer buf;                 /* Buffer containing leaf data */
+  Fts5Buffer pgidx;               /* Buffer containing page-index */
+  Fts5Buffer term;                /* Buffer containing previous term on page */
+};
+struct Fts5DlidxWriter {
+  int pgno;                       /* Page number for this page */
+  int bPrevValid;                 /* True if iPrev is valid */
+  i64 iPrev;                      /* Previous rowid value written to page */
+  Fts5Buffer buf;                 /* Buffer containing page data */
+};
+struct Fts5SegWriter {
+  int iSegid;                     /* Segid to write to */
+  Fts5PageWriter writer;          /* PageWriter object */
+  i64 iPrevRowid;                 /* Previous rowid written to current leaf */
+  u8 bFirstRowidInDoclist;        /* True if next rowid is first in doclist */
+  u8 bFirstRowidInPage;           /* True if next rowid is first in page */
+  /* TODO1: Can use (writer.pgidx.n==0) instead of bFirstTermInPage */
+  u8 bFirstTermInPage;            /* True if next term will be first in leaf */
+  int nLeafWritten;               /* Number of leaf pages written */
+  int nEmpty;                     /* Number of contiguous term-less nodes */
+
+  int nDlidx;                     /* Allocated size of aDlidx[] array */
+  Fts5DlidxWriter *aDlidx;        /* Array of Fts5DlidxWriter objects */
+
+  /* Values to insert into the %_idx table */
+  Fts5Buffer btterm;              /* Next term to insert into %_idx table */
+  int iBtPage;                    /* Page number corresponding to btterm */
+};
+
+typedef struct Fts5CResult Fts5CResult;
+struct Fts5CResult {
+  u16 iFirst;                     /* aSeg[] index of firstest iterator */
+  u8 bTermEq;                     /* True if the terms are equal */
+};
+
+/*
+** Object for iterating through a single segment, visiting each term/rowid
+** pair in the segment.
+**
+** pSeg:
+**   The segment to iterate through.
+**
+** iLeafPgno:
+**   Current leaf page number within segment.
+**
+** iLeafOffset:
+**   Byte offset within the current leaf that is the first byte of the 
+**   position list data (one byte passed the position-list size field).
+**   rowid field of the current entry. Usually this is the size field of the
+**   position list data. The exception is if the rowid for the current entry 
+**   is the last thing on the leaf page.
+**
+** pLeaf:
+**   Buffer containing current leaf page data. Set to NULL at EOF.
+**
+** iTermLeafPgno, iTermLeafOffset:
+**   Leaf page number containing the last term read from the segment. And
+**   the offset immediately following the term data.
+**
+** flags:
+**   Mask of FTS5_SEGITER_XXX values. Interpreted as follows:
+**
+**   FTS5_SEGITER_ONETERM:
+**     If set, set the iterator to point to EOF after the current doclist 
+**     has been exhausted. Do not proceed to the next term in the segment.
+**
+**   FTS5_SEGITER_REVERSE:
+**     This flag is only ever set if FTS5_SEGITER_ONETERM is also set. If
+**     it is set, iterate through rowid in descending order instead of the
+**     default ascending order.
+**
+** iRowidOffset/nRowidOffset/aRowidOffset:
+**     These are used if the FTS5_SEGITER_REVERSE flag is set.
+**
+**     For each rowid on the page corresponding to the current term, the
+**     corresponding aRowidOffset[] entry is set to the byte offset of the
+**     start of the "position-list-size" field within the page.
+**
+** iTermIdx:
+**     Index of current term on iTermLeafPgno.
+*/
+struct Fts5SegIter {
+  Fts5StructureSegment *pSeg;     /* Segment to iterate through */
+  int flags;                      /* Mask of configuration flags */
+  int iLeafPgno;                  /* Current leaf page number */
+  Fts5Data *pLeaf;                /* Current leaf data */
+  Fts5Data *pNextLeaf;            /* Leaf page (iLeafPgno+1) */
+  int iLeafOffset;                /* Byte offset within current leaf */
+
+  /* Next method */
+  void (*xNext)(Fts5Index*, Fts5SegIter*, int*);
+
+  /* The page and offset from which the current term was read. The offset 
+  ** is the offset of the first rowid in the current doclist.  */
+  int iTermLeafPgno;
+  int iTermLeafOffset;
+
+  int iPgidxOff;                  /* Next offset in pgidx */
+  int iEndofDoclist;
+
+  /* The following are only used if the FTS5_SEGITER_REVERSE flag is set. */
+  int iRowidOffset;               /* Current entry in aRowidOffset[] */
+  int nRowidOffset;               /* Allocated size of aRowidOffset[] array */
+  int *aRowidOffset;              /* Array of offset to rowid fields */
+
+  Fts5DlidxIter *pDlidx;          /* If there is a doclist-index */
+
+  /* Variables populated based on current entry. */
+  Fts5Buffer term;                /* Current term */
+  i64 iRowid;                     /* Current rowid */
+  int nPos;                       /* Number of bytes in current position list */
+  u8 bDel;                        /* True if the delete flag is set */
+};
+
+/*
+** Argument is a pointer to an Fts5Data structure that contains a 
+** leaf page.
+*/
+#define ASSERT_SZLEAF_OK(x) assert( \
+    (x)->szLeaf==(x)->nn || (x)->szLeaf==fts5GetU16(&(x)->p[2]) \
+)
+
+#define FTS5_SEGITER_ONETERM 0x01
+#define FTS5_SEGITER_REVERSE 0x02
+
+/* 
+** Argument is a pointer to an Fts5Data structure that contains a leaf
+** page. This macro evaluates to true if the leaf contains no terms, or
+** false if it contains at least one term.
+*/
+#define fts5LeafIsTermless(x) ((x)->szLeaf >= (x)->nn)
+
+#define fts5LeafTermOff(x, i) (fts5GetU16(&(x)->p[(x)->szLeaf + (i)*2]))
+
+#define fts5LeafFirstRowidOff(x) (fts5GetU16((x)->p))
+
+/*
+** Object for iterating through the merged results of one or more segments,
+** visiting each term/rowid pair in the merged data.
+**
+** nSeg is always a power of two greater than or equal to the number of
+** segments that this object is merging data from. Both the aSeg[] and
+** aFirst[] arrays are sized at nSeg entries. The aSeg[] array is padded
+** with zeroed objects - these are handled as if they were iterators opened
+** on empty segments.
+**
+** The results of comparing segments aSeg[N] and aSeg[N+1], where N is an
+** even number, is stored in aFirst[(nSeg+N)/2]. The "result" of the 
+** comparison in this context is the index of the iterator that currently
+** points to the smaller term/rowid combination. Iterators at EOF are
+** considered to be greater than all other iterators.
+**
+** aFirst[1] contains the index in aSeg[] of the iterator that points to
+** the smallest key overall. aFirst[0] is unused. 
+**
+** poslist:
+**   Used by sqlite3Fts5IterPoslist() when the poslist needs to be buffered.
+**   There is no way to tell if this is populated or not.
+*/
+struct Fts5Iter {
+  Fts5IndexIter base;             /* Base class containing output vars */
+
+  Fts5Index *pIndex;              /* Index that owns this iterator */
+  Fts5Structure *pStruct;         /* Database structure for this iterator */
+  Fts5Buffer poslist;             /* Buffer containing current poslist */
+  Fts5Colset *pColset;            /* Restrict matches to these columns */
+
+  /* Invoked to set output variables. */
+  void (*xSetOutputs)(Fts5Iter*, Fts5SegIter*);
+
+  int nSeg;                       /* Size of aSeg[] array */
+  int bRev;                       /* True to iterate in reverse order */
+  u8 bSkipEmpty;                  /* True to skip deleted entries */
+
+  i64 iSwitchRowid;               /* Firstest rowid of other than aFirst[1] */
+  Fts5CResult *aFirst;            /* Current merge state (see above) */
+  Fts5SegIter aSeg[1];            /* Array of segment iterators */
+};
+
+
+/*
+** An instance of the following type is used to iterate through the contents
+** of a doclist-index record.
+**
+** pData:
+**   Record containing the doclist-index data.
+**
+** bEof:
+**   Set to true once iterator has reached EOF.
+**
+** iOff:
+**   Set to the current offset within record pData.
+*/
+struct Fts5DlidxLvl {
+  Fts5Data *pData;              /* Data for current page of this level */
+  int iOff;                     /* Current offset into pData */
+  int bEof;                     /* At EOF already */
+  int iFirstOff;                /* Used by reverse iterators */
+
+  /* Output variables */
+  int iLeafPgno;                /* Page number of current leaf page */
+  i64 iRowid;                   /* First rowid on leaf iLeafPgno */
+};
+struct Fts5DlidxIter {
+  int nLvl;
+  int iSegid;
+  Fts5DlidxLvl aLvl[1];
+};
+
+static void fts5PutU16(u8 *aOut, u16 iVal){
+  aOut[0] = (iVal>>8);
+  aOut[1] = (iVal&0xFF);
+}
+
+static u16 fts5GetU16(const u8 *aIn){
+  return ((u16)aIn[0] << 8) + aIn[1];
+} 
+
+/*
+** Allocate and return a buffer at least nByte bytes in size.
+**
+** If an OOM error is encountered, return NULL and set the error code in
+** the Fts5Index handle passed as the first argument.
+*/
+static void *fts5IdxMalloc(Fts5Index *p, int nByte){
+  return sqlite3Fts5MallocZero(&p->rc, nByte);
+}
+
+/*
+** Compare the contents of the pLeft buffer with the pRight/nRight blob.
+**
+** Return -ve if pLeft is smaller than pRight, 0 if they are equal or
+** +ve if pRight is smaller than pLeft. In other words:
+**
+**     res = *pLeft - *pRight
+*/
+#ifdef SQLITE_DEBUG
+static int fts5BufferCompareBlob(
+  Fts5Buffer *pLeft,              /* Left hand side of comparison */
+  const u8 *pRight, int nRight    /* Right hand side of comparison */
+){
+  int nCmp = MIN(pLeft->n, nRight);
+  int res = memcmp(pLeft->p, pRight, nCmp);
+  return (res==0 ? (pLeft->n - nRight) : res);
+}
+#endif
+
+/*
+** Compare the contents of the two buffers using memcmp(). If one buffer
+** is a prefix of the other, it is considered the lesser.
+**
+** Return -ve if pLeft is smaller than pRight, 0 if they are equal or
+** +ve if pRight is smaller than pLeft. In other words:
+**
+**     res = *pLeft - *pRight
+*/
+static int fts5BufferCompare(Fts5Buffer *pLeft, Fts5Buffer *pRight){
+  int nCmp = MIN(pLeft->n, pRight->n);
+  int res = memcmp(pLeft->p, pRight->p, nCmp);
+  return (res==0 ? (pLeft->n - pRight->n) : res);
+}
+
+static int fts5LeafFirstTermOff(Fts5Data *pLeaf){
+  int ret;
+  fts5GetVarint32(&pLeaf->p[pLeaf->szLeaf], ret);
+  return ret;
+}
+
+/*
+** Close the read-only blob handle, if it is open.
+*/
+static void fts5CloseReader(Fts5Index *p){
+  if( p->pReader ){
+    sqlite3_blob *pReader = p->pReader;
+    p->pReader = 0;
+    sqlite3_blob_close(pReader);
+  }
+}
+
+
+/*
+** Retrieve a record from the %_data table.
+**
+** If an error occurs, NULL is returned and an error left in the 
+** Fts5Index object.
+*/
+static Fts5Data *fts5DataRead(Fts5Index *p, i64 iRowid){
+  Fts5Data *pRet = 0;
+  if( p->rc==SQLITE_OK ){
+    int rc = SQLITE_OK;
+
+    if( p->pReader ){
+      /* This call may return SQLITE_ABORT if there has been a savepoint
+      ** rollback since it was last used. In this case a new blob handle
+      ** is required.  */
+      sqlite3_blob *pBlob = p->pReader;
+      p->pReader = 0;
+      rc = sqlite3_blob_reopen(pBlob, iRowid);
+      assert( p->pReader==0 );
+      p->pReader = pBlob;
+      if( rc!=SQLITE_OK ){
+        fts5CloseReader(p);
+      }
+      if( rc==SQLITE_ABORT ) rc = SQLITE_OK;
+    }
+
+    /* If the blob handle is not open at this point, open it and seek 
+    ** to the requested entry.  */
+    if( p->pReader==0 && rc==SQLITE_OK ){
+      Fts5Config *pConfig = p->pConfig;
+      rc = sqlite3_blob_open(pConfig->db, 
+          pConfig->zDb, p->zDataTbl, "block", iRowid, 0, &p->pReader
+      );
+    }
+
+    /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls
+    ** above returned SQLITE_ERROR, return SQLITE_CORRUPT_VTAB instead.
+    ** All the reasons those functions might return SQLITE_ERROR - missing
+    ** table, missing row, non-blob/text in block column - indicate 
+    ** backing store corruption.  */
+    if( rc==SQLITE_ERROR ) rc = FTS5_CORRUPT;
+
+    if( rc==SQLITE_OK ){
+      u8 *aOut = 0;               /* Read blob data into this buffer */
+      int nByte = sqlite3_blob_bytes(p->pReader);
+      int nAlloc = sizeof(Fts5Data) + nByte + FTS5_DATA_PADDING;
+      pRet = (Fts5Data*)sqlite3_malloc(nAlloc);
+      if( pRet ){
+        pRet->nn = nByte;
+        aOut = pRet->p = (u8*)&pRet[1];
+      }else{
+        rc = SQLITE_NOMEM;
+      }
+
+      if( rc==SQLITE_OK ){
+        rc = sqlite3_blob_read(p->pReader, aOut, nByte, 0);
+      }
+      if( rc!=SQLITE_OK ){
+        sqlite3_free(pRet);
+        pRet = 0;
+      }else{
+        /* TODO1: Fix this */
+        pRet->szLeaf = fts5GetU16(&pRet->p[2]);
+      }
+    }
+    p->rc = rc;
+    p->nRead++;
+  }
+
+  assert( (pRet==0)==(p->rc!=SQLITE_OK) );
+  return pRet;
+}
+
+
+/*
+** Release a reference to data record returned by an earlier call to
+** fts5DataRead().
+*/
+static void fts5DataRelease(Fts5Data *pData){
+  sqlite3_free(pData);
+}
+
+static int fts5IndexPrepareStmt(
+  Fts5Index *p,
+  sqlite3_stmt **ppStmt,
+  char *zSql
+){
+  if( p->rc==SQLITE_OK ){
+    if( zSql ){
+      p->rc = sqlite3_prepare_v2(p->pConfig->db, zSql, -1, ppStmt, 0);
+    }else{
+      p->rc = SQLITE_NOMEM;
+    }
+  }
+  sqlite3_free(zSql);
+  return p->rc;
+}
+
+
+/*
+** INSERT OR REPLACE a record into the %_data table.
+*/
+static void fts5DataWrite(Fts5Index *p, i64 iRowid, const u8 *pData, int nData){
+  if( p->rc!=SQLITE_OK ) return;
+
+  if( p->pWriter==0 ){
+    Fts5Config *pConfig = p->pConfig;
+    fts5IndexPrepareStmt(p, &p->pWriter, sqlite3_mprintf(
+          "REPLACE INTO '%q'.'%q_data'(id, block) VALUES(?,?)", 
+          pConfig->zDb, pConfig->zName
+    ));
+    if( p->rc ) return;
+  }
+
+  sqlite3_bind_int64(p->pWriter, 1, iRowid);
+  sqlite3_bind_blob(p->pWriter, 2, pData, nData, SQLITE_STATIC);
+  sqlite3_step(p->pWriter);
+  p->rc = sqlite3_reset(p->pWriter);
+}
+
+/*
+** Execute the following SQL:
+**
+**     DELETE FROM %_data WHERE id BETWEEN $iFirst AND $iLast
+*/
+static void fts5DataDelete(Fts5Index *p, i64 iFirst, i64 iLast){
+  if( p->rc!=SQLITE_OK ) return;
+
+  if( p->pDeleter==0 ){
+    int rc;
+    Fts5Config *pConfig = p->pConfig;
+    char *zSql = sqlite3_mprintf(
+        "DELETE FROM '%q'.'%q_data' WHERE id>=? AND id<=?", 
+          pConfig->zDb, pConfig->zName
+    );
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &p->pDeleter, 0);
+      sqlite3_free(zSql);
+    }
+    if( rc!=SQLITE_OK ){
+      p->rc = rc;
+      return;
+    }
+  }
+
+  sqlite3_bind_int64(p->pDeleter, 1, iFirst);
+  sqlite3_bind_int64(p->pDeleter, 2, iLast);
+  sqlite3_step(p->pDeleter);
+  p->rc = sqlite3_reset(p->pDeleter);
+}
+
+/*
+** Remove all records associated with segment iSegid.
+*/
+static void fts5DataRemoveSegment(Fts5Index *p, int iSegid){
+  i64 iFirst = FTS5_SEGMENT_ROWID(iSegid, 0);
+  i64 iLast = FTS5_SEGMENT_ROWID(iSegid+1, 0)-1;
+  fts5DataDelete(p, iFirst, iLast);
+  if( p->pIdxDeleter==0 ){
+    Fts5Config *pConfig = p->pConfig;
+    fts5IndexPrepareStmt(p, &p->pIdxDeleter, sqlite3_mprintf(
+          "DELETE FROM '%q'.'%q_idx' WHERE segid=?",
+          pConfig->zDb, pConfig->zName
+    ));
+  }
+  if( p->rc==SQLITE_OK ){
+    sqlite3_bind_int(p->pIdxDeleter, 1, iSegid);
+    sqlite3_step(p->pIdxDeleter);
+    p->rc = sqlite3_reset(p->pIdxDeleter);
+  }
+}
+
+/*
+** Release a reference to an Fts5Structure object returned by an earlier 
+** call to fts5StructureRead() or fts5StructureDecode().
+*/
+static void fts5StructureRelease(Fts5Structure *pStruct){
+  if( pStruct && 0>=(--pStruct->nRef) ){
+    int i;
+    assert( pStruct->nRef==0 );
+    for(i=0; i<pStruct->nLevel; i++){
+      sqlite3_free(pStruct->aLevel[i].aSeg);
+    }
+    sqlite3_free(pStruct);
+  }
+}
+
+static void fts5StructureRef(Fts5Structure *pStruct){
+  pStruct->nRef++;
+}
+
+/*
+** Deserialize and return the structure record currently stored in serialized
+** form within buffer pData/nData.
+**
+** The Fts5Structure.aLevel[] and each Fts5StructureLevel.aSeg[] array
+** are over-allocated by one slot. This allows the structure contents
+** to be more easily edited.
+**
+** If an error occurs, *ppOut is set to NULL and an SQLite error code
+** returned. Otherwise, *ppOut is set to point to the new object and
+** SQLITE_OK returned.
+*/
+static int fts5StructureDecode(
+  const u8 *pData,                /* Buffer containing serialized structure */
+  int nData,                      /* Size of buffer pData in bytes */
+  int *piCookie,                  /* Configuration cookie value */
+  Fts5Structure **ppOut           /* OUT: Deserialized object */
+){
+  int rc = SQLITE_OK;
+  int i = 0;
+  int iLvl;
+  int nLevel = 0;
+  int nSegment = 0;
+  int nByte;                      /* Bytes of space to allocate at pRet */
+  Fts5Structure *pRet = 0;        /* Structure object to return */
+
+  /* Grab the cookie value */
+  if( piCookie ) *piCookie = sqlite3Fts5Get32(pData);
+  i = 4;
+
+  /* Read the total number of levels and segments from the start of the
+  ** structure record.  */
+  i += fts5GetVarint32(&pData[i], nLevel);
+  i += fts5GetVarint32(&pData[i], nSegment);
+  nByte = (
+      sizeof(Fts5Structure) +                    /* Main structure */
+      sizeof(Fts5StructureLevel) * (nLevel-1)    /* aLevel[] array */
+  );
+  pRet = (Fts5Structure*)sqlite3Fts5MallocZero(&rc, nByte);
+
+  if( pRet ){
+    pRet->nRef = 1;
+    pRet->nLevel = nLevel;
+    pRet->nSegment = nSegment;
+    i += sqlite3Fts5GetVarint(&pData[i], &pRet->nWriteCounter);
+
+    for(iLvl=0; rc==SQLITE_OK && iLvl<nLevel; iLvl++){
+      Fts5StructureLevel *pLvl = &pRet->aLevel[iLvl];
+      int nTotal = 0;
+      int iSeg;
+
+      if( i>=nData ){
+        rc = FTS5_CORRUPT;
+      }else{
+        i += fts5GetVarint32(&pData[i], pLvl->nMerge);
+        i += fts5GetVarint32(&pData[i], nTotal);
+        assert( nTotal>=pLvl->nMerge );
+        pLvl->aSeg = (Fts5StructureSegment*)sqlite3Fts5MallocZero(&rc, 
+            nTotal * sizeof(Fts5StructureSegment)
+        );
+      }
+
+      if( rc==SQLITE_OK ){
+        pLvl->nSeg = nTotal;
+        for(iSeg=0; iSeg<nTotal; iSeg++){
+          if( i>=nData ){
+            rc = FTS5_CORRUPT;
+            break;
+          }
+          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].iSegid);
+          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoFirst);
+          i += fts5GetVarint32(&pData[i], pLvl->aSeg[iSeg].pgnoLast);
+        }
+      }
+    }
+    if( rc!=SQLITE_OK ){
+      fts5StructureRelease(pRet);
+      pRet = 0;
+    }
+  }
+
+  *ppOut = pRet;
+  return rc;
+}
+
+/*
+**
+*/
+static void fts5StructureAddLevel(int *pRc, Fts5Structure **ppStruct){
+  if( *pRc==SQLITE_OK ){
+    Fts5Structure *pStruct = *ppStruct;
+    int nLevel = pStruct->nLevel;
+    int nByte = (
+        sizeof(Fts5Structure) +                  /* Main structure */
+        sizeof(Fts5StructureLevel) * (nLevel+1)  /* aLevel[] array */
+    );
+
+    pStruct = sqlite3_realloc(pStruct, nByte);
+    if( pStruct ){
+      memset(&pStruct->aLevel[nLevel], 0, sizeof(Fts5StructureLevel));
+      pStruct->nLevel++;
+      *ppStruct = pStruct;
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+}
+
+/*
+** Extend level iLvl so that there is room for at least nExtra more
+** segments.
+*/
+static void fts5StructureExtendLevel(
+  int *pRc, 
+  Fts5Structure *pStruct, 
+  int iLvl, 
+  int nExtra, 
+  int bInsert
+){
+  if( *pRc==SQLITE_OK ){
+    Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
+    Fts5StructureSegment *aNew;
+    int nByte;
+
+    nByte = (pLvl->nSeg + nExtra) * sizeof(Fts5StructureSegment);
+    aNew = sqlite3_realloc(pLvl->aSeg, nByte);
+    if( aNew ){
+      if( bInsert==0 ){
+        memset(&aNew[pLvl->nSeg], 0, sizeof(Fts5StructureSegment) * nExtra);
+      }else{
+        int nMove = pLvl->nSeg * sizeof(Fts5StructureSegment);
+        memmove(&aNew[nExtra], aNew, nMove);
+        memset(aNew, 0, sizeof(Fts5StructureSegment) * nExtra);
+      }
+      pLvl->aSeg = aNew;
+    }else{
+      *pRc = SQLITE_NOMEM;
+    }
+  }
+}
+
+static Fts5Structure *fts5StructureReadUncached(Fts5Index *p){
+  Fts5Structure *pRet = 0;
+  Fts5Config *pConfig = p->pConfig;
+  int iCookie;                    /* Configuration cookie */
+  Fts5Data *pData;
+
+  pData = fts5DataRead(p, FTS5_STRUCTURE_ROWID);
+  if( p->rc==SQLITE_OK ){
+    /* TODO: Do we need this if the leaf-index is appended? Probably... */
+    memset(&pData->p[pData->nn], 0, FTS5_DATA_PADDING);
+    p->rc = fts5StructureDecode(pData->p, pData->nn, &iCookie, &pRet);
+    if( p->rc==SQLITE_OK && pConfig->iCookie!=iCookie ){
+      p->rc = sqlite3Fts5ConfigLoad(pConfig, iCookie);
+    }
+    fts5DataRelease(pData);
+    if( p->rc!=SQLITE_OK ){
+      fts5StructureRelease(pRet);
+      pRet = 0;
+    }
+  }
+
+  return pRet;
+}
+
+static i64 fts5IndexDataVersion(Fts5Index *p){
+  i64 iVersion = 0;
+
+  if( p->rc==SQLITE_OK ){
+    if( p->pDataVersion==0 ){
+      p->rc = fts5IndexPrepareStmt(p, &p->pDataVersion, 
+          sqlite3_mprintf("PRAGMA %Q.data_version", p->pConfig->zDb)
+          );
+      if( p->rc ) return 0;
+    }
+
+    if( SQLITE_ROW==sqlite3_step(p->pDataVersion) ){
+      iVersion = sqlite3_column_int64(p->pDataVersion, 0);
+    }
+    p->rc = sqlite3_reset(p->pDataVersion);
+  }
+
+  return iVersion;
+}
+
+/*
+** Read, deserialize and return the structure record.
+**
+** The Fts5Structure.aLevel[] and each Fts5StructureLevel.aSeg[] array
+** are over-allocated as described for function fts5StructureDecode() 
+** above.
+**
+** If an error occurs, NULL is returned and an error code left in the
+** Fts5Index handle. If an error has already occurred when this function
+** is called, it is a no-op.
+*/
+static Fts5Structure *fts5StructureRead(Fts5Index *p){
+
+  if( p->pStruct==0 ){
+    p->iStructVersion = fts5IndexDataVersion(p);
+    if( p->rc==SQLITE_OK ){
+      p->pStruct = fts5StructureReadUncached(p);
+    }
+  }
+
+#if 0
+  else{
+    Fts5Structure *pTest = fts5StructureReadUncached(p);
+    if( pTest ){
+      int i, j;
+      assert_nc( p->pStruct->nSegment==pTest->nSegment );
+      assert_nc( p->pStruct->nLevel==pTest->nLevel );
+      for(i=0; i<pTest->nLevel; i++){
+        assert_nc( p->pStruct->aLevel[i].nMerge==pTest->aLevel[i].nMerge );
+        assert_nc( p->pStruct->aLevel[i].nSeg==pTest->aLevel[i].nSeg );
+        for(j=0; j<pTest->aLevel[i].nSeg; j++){
+          Fts5StructureSegment *p1 = &pTest->aLevel[i].aSeg[j];
+          Fts5StructureSegment *p2 = &p->pStruct->aLevel[i].aSeg[j];
+          assert_nc( p1->iSegid==p2->iSegid );
+          assert_nc( p1->pgnoFirst==p2->pgnoFirst );
+          assert_nc( p1->pgnoLast==p2->pgnoLast );
+        }
+      }
+      fts5StructureRelease(pTest);
+    }
+  }
+#endif
+
+  if( p->rc!=SQLITE_OK ) return 0;
+  assert( p->iStructVersion!=0 );
+  assert( p->pStruct!=0 );
+  fts5StructureRef(p->pStruct);
+  return p->pStruct;
+}
+
+static void fts5StructureInvalidate(Fts5Index *p){
+  if( p->pStruct ){
+    fts5StructureRelease(p->pStruct);
+    p->pStruct = 0;
+  }
+}
+
+/*
+** Return the total number of segments in index structure pStruct. This
+** function is only ever used as part of assert() conditions.
+*/
+#ifdef SQLITE_DEBUG
+static int fts5StructureCountSegments(Fts5Structure *pStruct){
+  int nSegment = 0;               /* Total number of segments */
+  if( pStruct ){
+    int iLvl;                     /* Used to iterate through levels */
+    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+      nSegment += pStruct->aLevel[iLvl].nSeg;
+    }
+  }
+
+  return nSegment;
+}
+#endif
+
+#define fts5BufferSafeAppendBlob(pBuf, pBlob, nBlob) {     \
+  assert( (pBuf)->nSpace>=((pBuf)->n+nBlob) );             \
+  memcpy(&(pBuf)->p[(pBuf)->n], pBlob, nBlob);             \
+  (pBuf)->n += nBlob;                                      \
+}
+
+#define fts5BufferSafeAppendVarint(pBuf, iVal) {                \
+  (pBuf)->n += sqlite3Fts5PutVarint(&(pBuf)->p[(pBuf)->n], (iVal));  \
+  assert( (pBuf)->nSpace>=(pBuf)->n );                          \
+}
+
+
+/*
+** Serialize and store the "structure" record.
+**
+** If an error occurs, leave an error code in the Fts5Index object. If an
+** error has already occurred, this function is a no-op.
+*/
+static void fts5StructureWrite(Fts5Index *p, Fts5Structure *pStruct){
+  if( p->rc==SQLITE_OK ){
+    Fts5Buffer buf;               /* Buffer to serialize record into */
+    int iLvl;                     /* Used to iterate through levels */
+    int iCookie;                  /* Cookie value to store */
+
+    assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
+    memset(&buf, 0, sizeof(Fts5Buffer));
+
+    /* Append the current configuration cookie */
+    iCookie = p->pConfig->iCookie;
+    if( iCookie<0 ) iCookie = 0;
+
+    if( 0==sqlite3Fts5BufferSize(&p->rc, &buf, 4+9+9+9) ){
+      sqlite3Fts5Put32(buf.p, iCookie);
+      buf.n = 4;
+      fts5BufferSafeAppendVarint(&buf, pStruct->nLevel);
+      fts5BufferSafeAppendVarint(&buf, pStruct->nSegment);
+      fts5BufferSafeAppendVarint(&buf, (i64)pStruct->nWriteCounter);
+    }
+
+    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+      int iSeg;                     /* Used to iterate through segments */
+      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
+      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nMerge);
+      fts5BufferAppendVarint(&p->rc, &buf, pLvl->nSeg);
+      assert( pLvl->nMerge<=pLvl->nSeg );
+
+      for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
+        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].iSegid);
+        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoFirst);
+        fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoLast);
+      }
+    }
+
+    fts5DataWrite(p, FTS5_STRUCTURE_ROWID, buf.p, buf.n);
+    fts5BufferFree(&buf);
+  }
+}
+
+#if 0
+static void fts5DebugStructure(int*,Fts5Buffer*,Fts5Structure*);
+static void fts5PrintStructure(const char *zCaption, Fts5Structure *pStruct){
+  int rc = SQLITE_OK;
+  Fts5Buffer buf;
+  memset(&buf, 0, sizeof(buf));
+  fts5DebugStructure(&rc, &buf, pStruct);
+  fprintf(stdout, "%s: %s\n", zCaption, buf.p);
+  fflush(stdout);
+  fts5BufferFree(&buf);
+}
+#else
+# define fts5PrintStructure(x,y)
+#endif
+
+static int fts5SegmentSize(Fts5StructureSegment *pSeg){
+  return 1 + pSeg->pgnoLast - pSeg->pgnoFirst;
+}
+
+/*
+** Return a copy of index structure pStruct. Except, promote as many 
+** segments as possible to level iPromote. If an OOM occurs, NULL is 
+** returned.
+*/
+static void fts5StructurePromoteTo(
+  Fts5Index *p,
+  int iPromote,
+  int szPromote,
+  Fts5Structure *pStruct
+){
+  int il, is;
+  Fts5StructureLevel *pOut = &pStruct->aLevel[iPromote];
+
+  if( pOut->nMerge==0 ){
+    for(il=iPromote+1; il<pStruct->nLevel; il++){
+      Fts5StructureLevel *pLvl = &pStruct->aLevel[il];
+      if( pLvl->nMerge ) return;
+      for(is=pLvl->nSeg-1; is>=0; is--){
+        int sz = fts5SegmentSize(&pLvl->aSeg[is]);
+        if( sz>szPromote ) return;
+        fts5StructureExtendLevel(&p->rc, pStruct, iPromote, 1, 1);
+        if( p->rc ) return;
+        memcpy(pOut->aSeg, &pLvl->aSeg[is], sizeof(Fts5StructureSegment));
+        pOut->nSeg++;
+        pLvl->nSeg--;
+      }
+    }
+  }
+}
+
+/*
+** A new segment has just been written to level iLvl of index structure
+** pStruct. This function determines if any segments should be promoted
+** as a result. Segments are promoted in two scenarios:
+**
+**   a) If the segment just written is smaller than one or more segments
+**      within the previous populated level, it is promoted to the previous
+**      populated level.
+**
+**   b) If the segment just written is larger than the newest segment on
+**      the next populated level, then that segment, and any other adjacent
+**      segments that are also smaller than the one just written, are 
+**      promoted. 
+**
+** If one or more segments are promoted, the structure object is updated
+** to reflect this.
+*/
+static void fts5StructurePromote(
+  Fts5Index *p,                   /* FTS5 backend object */
+  int iLvl,                       /* Index level just updated */
+  Fts5Structure *pStruct          /* Index structure */
+){
+  if( p->rc==SQLITE_OK ){
+    int iTst;
+    int iPromote = -1;
+    int szPromote = 0;            /* Promote anything this size or smaller */
+    Fts5StructureSegment *pSeg;   /* Segment just written */
+    int szSeg;                    /* Size of segment just written */
+    int nSeg = pStruct->aLevel[iLvl].nSeg;
+
+    if( nSeg==0 ) return;
+    pSeg = &pStruct->aLevel[iLvl].aSeg[pStruct->aLevel[iLvl].nSeg-1];
+    szSeg = (1 + pSeg->pgnoLast - pSeg->pgnoFirst);
+
+    /* Check for condition (a) */
+    for(iTst=iLvl-1; iTst>=0 && pStruct->aLevel[iTst].nSeg==0; iTst--);
+    if( iTst>=0 ){
+      int i;
+      int szMax = 0;
+      Fts5StructureLevel *pTst = &pStruct->aLevel[iTst];
+      assert( pTst->nMerge==0 );
+      for(i=0; i<pTst->nSeg; i++){
+        int sz = pTst->aSeg[i].pgnoLast - pTst->aSeg[i].pgnoFirst + 1;
+        if( sz>szMax ) szMax = sz;
+      }
+      if( szMax>=szSeg ){
+        /* Condition (a) is true. Promote the newest segment on level 
+        ** iLvl to level iTst.  */
+        iPromote = iTst;
+        szPromote = szMax;
+      }
+    }
+
+    /* If condition (a) is not met, assume (b) is true. StructurePromoteTo()
+    ** is a no-op if it is not.  */
+    if( iPromote<0 ){
+      iPromote = iLvl;
+      szPromote = szSeg;
+    }
+    fts5StructurePromoteTo(p, iPromote, szPromote, pStruct);
+  }
+}
+
+
+/*
+** Advance the iterator passed as the only argument. If the end of the 
+** doclist-index page is reached, return non-zero.
+*/
+static int fts5DlidxLvlNext(Fts5DlidxLvl *pLvl){
+  Fts5Data *pData = pLvl->pData;
+
+  if( pLvl->iOff==0 ){
+    assert( pLvl->bEof==0 );
+    pLvl->iOff = 1;
+    pLvl->iOff += fts5GetVarint32(&pData->p[1], pLvl->iLeafPgno);
+    pLvl->iOff += fts5GetVarint(&pData->p[pLvl->iOff], (u64*)&pLvl->iRowid);
+    pLvl->iFirstOff = pLvl->iOff;
+  }else{
+    int iOff;
+    for(iOff=pLvl->iOff; iOff<pData->nn; iOff++){
+      if( pData->p[iOff] ) break; 
+    }
+
+    if( iOff<pData->nn ){
+      i64 iVal;
+      pLvl->iLeafPgno += (iOff - pLvl->iOff) + 1;
+      iOff += fts5GetVarint(&pData->p[iOff], (u64*)&iVal);
+      pLvl->iRowid += iVal;
+      pLvl->iOff = iOff;
+    }else{
+      pLvl->bEof = 1;
+    }
+  }
+
+  return pLvl->bEof;
+}
+
+/*
+** Advance the iterator passed as the only argument.
+*/
+static int fts5DlidxIterNextR(Fts5Index *p, Fts5DlidxIter *pIter, int iLvl){
+  Fts5DlidxLvl *pLvl = &pIter->aLvl[iLvl];
+
+  assert( iLvl<pIter->nLvl );
+  if( fts5DlidxLvlNext(pLvl) ){
+    if( (iLvl+1) < pIter->nLvl ){
+      fts5DlidxIterNextR(p, pIter, iLvl+1);
+      if( pLvl[1].bEof==0 ){
+        fts5DataRelease(pLvl->pData);
+        memset(pLvl, 0, sizeof(Fts5DlidxLvl));
+        pLvl->pData = fts5DataRead(p, 
+            FTS5_DLIDX_ROWID(pIter->iSegid, iLvl, pLvl[1].iLeafPgno)
+        );
+        if( pLvl->pData ) fts5DlidxLvlNext(pLvl);
+      }
+    }
+  }
+
+  return pIter->aLvl[0].bEof;
+}
+static int fts5DlidxIterNext(Fts5Index *p, Fts5DlidxIter *pIter){
+  return fts5DlidxIterNextR(p, pIter, 0);
+}
+
+/*
+** The iterator passed as the first argument has the following fields set
+** as follows. This function sets up the rest of the iterator so that it
+** points to the first rowid in the doclist-index.
+**
+**   pData:
+**     pointer to doclist-index record, 
+**
+** When this function is called pIter->iLeafPgno is the page number the
+** doclist is associated with (the one featuring the term).
+*/
+static int fts5DlidxIterFirst(Fts5DlidxIter *pIter){
+  int i;
+  for(i=0; i<pIter->nLvl; i++){
+    fts5DlidxLvlNext(&pIter->aLvl[i]);
+  }
+  return pIter->aLvl[0].bEof;
+}
+
+
+static int fts5DlidxIterEof(Fts5Index *p, Fts5DlidxIter *pIter){
+  return p->rc!=SQLITE_OK || pIter->aLvl[0].bEof;
+}
+
+static void fts5DlidxIterLast(Fts5Index *p, Fts5DlidxIter *pIter){
+  int i;
+
+  /* Advance each level to the last entry on the last page */
+  for(i=pIter->nLvl-1; p->rc==SQLITE_OK && i>=0; i--){
+    Fts5DlidxLvl *pLvl = &pIter->aLvl[i];
+    while( fts5DlidxLvlNext(pLvl)==0 );
+    pLvl->bEof = 0;
+
+    if( i>0 ){
+      Fts5DlidxLvl *pChild = &pLvl[-1];
+      fts5DataRelease(pChild->pData);
+      memset(pChild, 0, sizeof(Fts5DlidxLvl));
+      pChild->pData = fts5DataRead(p, 
+          FTS5_DLIDX_ROWID(pIter->iSegid, i-1, pLvl->iLeafPgno)
+      );
+    }
+  }
+}
+
+/*
+** Move the iterator passed as the only argument to the previous entry.
+*/
+static int fts5DlidxLvlPrev(Fts5DlidxLvl *pLvl){
+  int iOff = pLvl->iOff;
+
+  assert( pLvl->bEof==0 );
+  if( iOff<=pLvl->iFirstOff ){
+    pLvl->bEof = 1;
+  }else{
+    u8 *a = pLvl->pData->p;
+    i64 iVal;
+    int iLimit;
+    int ii;
+    int nZero = 0;
+
+    /* Currently iOff points to the first byte of a varint. This block 
+    ** decrements iOff until it points to the first byte of the previous 
+    ** varint. Taking care not to read any memory locations that occur
+    ** before the buffer in memory.  */
+    iLimit = (iOff>9 ? iOff-9 : 0);
+    for(iOff--; iOff>iLimit; iOff--){
+      if( (a[iOff-1] & 0x80)==0 ) break;
+    }
+
+    fts5GetVarint(&a[iOff], (u64*)&iVal);
+    pLvl->iRowid -= iVal;
+    pLvl->iLeafPgno--;
+
+    /* Skip backwards past any 0x00 varints. */
+    for(ii=iOff-1; ii>=pLvl->iFirstOff && a[ii]==0x00; ii--){
+      nZero++;
+    }
+    if( ii>=pLvl->iFirstOff && (a[ii] & 0x80) ){
+      /* The byte immediately before the last 0x00 byte has the 0x80 bit
+      ** set. So the last 0x00 is only a varint 0 if there are 8 more 0x80
+      ** bytes before a[ii]. */
+      int bZero = 0;              /* True if last 0x00 counts */
+      if( (ii-8)>=pLvl->iFirstOff ){
+        int j;
+        for(j=1; j<=8 && (a[ii-j] & 0x80); j++);
+        bZero = (j>8);
+      }
+      if( bZero==0 ) nZero--;
+    }
+    pLvl->iLeafPgno -= nZero;
+    pLvl->iOff = iOff - nZero;
+  }
+
+  return pLvl->bEof;
+}
+
+static int fts5DlidxIterPrevR(Fts5Index *p, Fts5DlidxIter *pIter, int iLvl){
+  Fts5DlidxLvl *pLvl = &pIter->aLvl[iLvl];
+
+  assert( iLvl<pIter->nLvl );
+  if( fts5DlidxLvlPrev(pLvl) ){
+    if( (iLvl+1) < pIter->nLvl ){
+      fts5DlidxIterPrevR(p, pIter, iLvl+1);
+      if( pLvl[1].bEof==0 ){
+        fts5DataRelease(pLvl->pData);
+        memset(pLvl, 0, sizeof(Fts5DlidxLvl));
+        pLvl->pData = fts5DataRead(p, 
+            FTS5_DLIDX_ROWID(pIter->iSegid, iLvl, pLvl[1].iLeafPgno)
+        );
+        if( pLvl->pData ){
+          while( fts5DlidxLvlNext(pLvl)==0 );
+          pLvl->bEof = 0;
+        }
+      }
+    }
+  }
+
+  return pIter->aLvl[0].bEof;
+}
+static int fts5DlidxIterPrev(Fts5Index *p, Fts5DlidxIter *pIter){
+  return fts5DlidxIterPrevR(p, pIter, 0);
+}
+
+/*
+** Free a doclist-index iterator object allocated by fts5DlidxIterInit().
+*/
+static void fts5DlidxIterFree(Fts5DlidxIter *pIter){
+  if( pIter ){
+    int i;
+    for(i=0; i<pIter->nLvl; i++){
+      fts5DataRelease(pIter->aLvl[i].pData);
+    }
+    sqlite3_free(pIter);
+  }
+}
+
+static Fts5DlidxIter *fts5DlidxIterInit(
+  Fts5Index *p,                   /* Fts5 Backend to iterate within */
+  int bRev,                       /* True for ORDER BY ASC */
+  int iSegid,                     /* Segment id */
+  int iLeafPg                     /* Leaf page number to load dlidx for */
+){
+  Fts5DlidxIter *pIter = 0;
+  int i;
+  int bDone = 0;
+
+  for(i=0; p->rc==SQLITE_OK && bDone==0; i++){
+    int nByte = sizeof(Fts5DlidxIter) + i * sizeof(Fts5DlidxLvl);
+    Fts5DlidxIter *pNew;
+
+    pNew = (Fts5DlidxIter*)sqlite3_realloc(pIter, nByte);
+    if( pNew==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      i64 iRowid = FTS5_DLIDX_ROWID(iSegid, i, iLeafPg);
+      Fts5DlidxLvl *pLvl = &pNew->aLvl[i];
+      pIter = pNew;
+      memset(pLvl, 0, sizeof(Fts5DlidxLvl));
+      pLvl->pData = fts5DataRead(p, iRowid);
+      if( pLvl->pData && (pLvl->pData->p[0] & 0x0001)==0 ){
+        bDone = 1;
+      }
+      pIter->nLvl = i+1;
+    }
+  }
+
+  if( p->rc==SQLITE_OK ){
+    pIter->iSegid = iSegid;
+    if( bRev==0 ){
+      fts5DlidxIterFirst(pIter);
+    }else{
+      fts5DlidxIterLast(p, pIter);
+    }
+  }
+
+  if( p->rc!=SQLITE_OK ){
+    fts5DlidxIterFree(pIter);
+    pIter = 0;
+  }
+
+  return pIter;
+}
+
+static i64 fts5DlidxIterRowid(Fts5DlidxIter *pIter){
+  return pIter->aLvl[0].iRowid;
+}
+static int fts5DlidxIterPgno(Fts5DlidxIter *pIter){
+  return pIter->aLvl[0].iLeafPgno;
+}
+
+/*
+** Load the next leaf page into the segment iterator.
+*/
+static void fts5SegIterNextPage(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter              /* Iterator to advance to next page */
+){
+  Fts5Data *pLeaf;
+  Fts5StructureSegment *pSeg = pIter->pSeg;
+  fts5DataRelease(pIter->pLeaf);
+  pIter->iLeafPgno++;
+  if( pIter->pNextLeaf ){
+    pIter->pLeaf = pIter->pNextLeaf;
+    pIter->pNextLeaf = 0;
+  }else if( pIter->iLeafPgno<=pSeg->pgnoLast ){
+    pIter->pLeaf = fts5DataRead(p, 
+        FTS5_SEGMENT_ROWID(pSeg->iSegid, pIter->iLeafPgno)
+    );
+  }else{
+    pIter->pLeaf = 0;
+  }
+  pLeaf = pIter->pLeaf;
+
+  if( pLeaf ){
+    pIter->iPgidxOff = pLeaf->szLeaf;
+    if( fts5LeafIsTermless(pLeaf) ){
+      pIter->iEndofDoclist = pLeaf->nn+1;
+    }else{
+      pIter->iPgidxOff += fts5GetVarint32(&pLeaf->p[pIter->iPgidxOff],
+          pIter->iEndofDoclist
+      );
+    }
+  }
+}
+
+/*
+** Argument p points to a buffer containing a varint to be interpreted as a
+** position list size field. Read the varint and return the number of bytes
+** read. Before returning, set *pnSz to the number of bytes in the position
+** list, and *pbDel to true if the delete flag is set, or false otherwise.
+*/
+static int fts5GetPoslistSize(const u8 *p, int *pnSz, int *pbDel){
+  int nSz;
+  int n = 0;
+  fts5FastGetVarint32(p, n, nSz);
+  assert_nc( nSz>=0 );
+  *pnSz = nSz/2;
+  *pbDel = nSz & 0x0001;
+  return n;
+}
+
+/*
+** Fts5SegIter.iLeafOffset currently points to the first byte of a
+** position-list size field. Read the value of the field and store it
+** in the following variables:
+**
+**   Fts5SegIter.nPos
+**   Fts5SegIter.bDel
+**
+** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 
+** position list content (if any).
+*/
+static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){
+  if( p->rc==SQLITE_OK ){
+    int iOff = pIter->iLeafOffset;  /* Offset to read at */
+    ASSERT_SZLEAF_OK(pIter->pLeaf);
+    if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){
+      int iEod = MIN(pIter->iEndofDoclist, pIter->pLeaf->szLeaf);
+      pIter->bDel = 0;
+      pIter->nPos = 1;
+      if( iOff<iEod && pIter->pLeaf->p[iOff]==0 ){
+        pIter->bDel = 1;
+        iOff++;
+        if( iOff<iEod && pIter->pLeaf->p[iOff]==0 ){
+          pIter->nPos = 1;
+          iOff++;
+        }else{
+          pIter->nPos = 0;
+        }
+      }
+    }else{
+      int nSz;
+      fts5FastGetVarint32(pIter->pLeaf->p, iOff, nSz);
+      pIter->bDel = (nSz & 0x0001);
+      pIter->nPos = nSz>>1;
+      assert_nc( pIter->nPos>=0 );
+    }
+    pIter->iLeafOffset = iOff;
+  }
+}
+
+static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){
+  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
+  int iOff = pIter->iLeafOffset;
+
+  ASSERT_SZLEAF_OK(pIter->pLeaf);
+  if( iOff>=pIter->pLeaf->szLeaf ){
+    fts5SegIterNextPage(p, pIter);
+    if( pIter->pLeaf==0 ){
+      if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
+      return;
+    }
+    iOff = 4;
+    a = pIter->pLeaf->p;
+  }
+  iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
+  pIter->iLeafOffset = iOff;
+}
+
+/*
+** Fts5SegIter.iLeafOffset currently points to the first byte of the 
+** "nSuffix" field of a term. Function parameter nKeep contains the value
+** of the "nPrefix" field (if there was one - it is passed 0 if this is
+** the first term in the segment).
+**
+** This function populates:
+**
+**   Fts5SegIter.term
+**   Fts5SegIter.rowid
+**
+** accordingly and leaves (Fts5SegIter.iLeafOffset) set to the content of
+** the first position list. The position list belonging to document 
+** (Fts5SegIter.iRowid).
+*/
+static void fts5SegIterLoadTerm(Fts5Index *p, Fts5SegIter *pIter, int nKeep){
+  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */
+  int iOff = pIter->iLeafOffset;  /* Offset to read at */
+  int nNew;                       /* Bytes of new data */
+
+  iOff += fts5GetVarint32(&a[iOff], nNew);
+  if( iOff+nNew>pIter->pLeaf->nn ){
+    p->rc = FTS5_CORRUPT;
+    return;
+  }
+  pIter->term.n = nKeep;
+  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
+  iOff += nNew;
+  pIter->iTermLeafOffset = iOff;
+  pIter->iTermLeafPgno = pIter->iLeafPgno;
+  pIter->iLeafOffset = iOff;
+
+  if( pIter->iPgidxOff>=pIter->pLeaf->nn ){
+    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
+  }else{
+    int nExtra;
+    pIter->iPgidxOff += fts5GetVarint32(&a[pIter->iPgidxOff], nExtra);
+    pIter->iEndofDoclist += nExtra;
+  }
+
+  fts5SegIterLoadRowid(p, pIter);
+}
+
+static void fts5SegIterNext(Fts5Index*, Fts5SegIter*, int*);
+static void fts5SegIterNext_Reverse(Fts5Index*, Fts5SegIter*, int*);
+static void fts5SegIterNext_None(Fts5Index*, Fts5SegIter*, int*);
+
+static void fts5SegIterSetNext(Fts5Index *p, Fts5SegIter *pIter){
+  if( pIter->flags & FTS5_SEGITER_REVERSE ){
+    pIter->xNext = fts5SegIterNext_Reverse;
+  }else if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){
+    pIter->xNext = fts5SegIterNext_None;
+  }else{
+    pIter->xNext = fts5SegIterNext;
+  }
+}
+
+/*
+** Initialize the iterator object pIter to iterate through the entries in
+** segment pSeg. The iterator is left pointing to the first entry when 
+** this function returns.
+**
+** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
+** an error has already occurred when this function is called, it is a no-op.
+*/
+static void fts5SegIterInit(
+  Fts5Index *p,                   /* FTS index object */
+  Fts5StructureSegment *pSeg,     /* Description of segment */
+  Fts5SegIter *pIter              /* Object to populate */
+){
+  if( pSeg->pgnoFirst==0 ){
+    /* This happens if the segment is being used as an input to an incremental
+    ** merge and all data has already been "trimmed". See function
+    ** fts5TrimSegments() for details. In this case leave the iterator empty.
+    ** The caller will see the (pIter->pLeaf==0) and assume the iterator is
+    ** at EOF already. */
+    assert( pIter->pLeaf==0 );
+    return;
+  }
+
+  if( p->rc==SQLITE_OK ){
+    memset(pIter, 0, sizeof(*pIter));
+    fts5SegIterSetNext(p, pIter);
+    pIter->pSeg = pSeg;
+    pIter->iLeafPgno = pSeg->pgnoFirst-1;
+    fts5SegIterNextPage(p, pIter);
+  }
+
+  if( p->rc==SQLITE_OK ){
+    pIter->iLeafOffset = 4;
+    assert_nc( pIter->pLeaf->nn>4 );
+    assert( fts5LeafFirstTermOff(pIter->pLeaf)==4 );
+    pIter->iPgidxOff = pIter->pLeaf->szLeaf+1;
+    fts5SegIterLoadTerm(p, pIter, 0);
+    fts5SegIterLoadNPos(p, pIter);
+  }
+}
+
+/*
+** This function is only ever called on iterators created by calls to
+** Fts5IndexQuery() with the FTS5INDEX_QUERY_DESC flag set.
+**
+** The iterator is in an unusual state when this function is called: the
+** Fts5SegIter.iLeafOffset variable is set to the offset of the start of
+** the position-list size field for the first relevant rowid on the page.
+** Fts5SegIter.rowid is set, but nPos and bDel are not.
+**
+** This function advances the iterator so that it points to the last 
+** relevant rowid on the page and, if necessary, initializes the 
+** aRowidOffset[] and iRowidOffset variables. At this point the iterator
+** is in its regular state - Fts5SegIter.iLeafOffset points to the first
+** byte of the position list content associated with said rowid.
+*/
+static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){
+  int eDetail = p->pConfig->eDetail;
+  int n = pIter->pLeaf->szLeaf;
+  int i = pIter->iLeafOffset;
+  u8 *a = pIter->pLeaf->p;
+  int iRowidOffset = 0;
+
+  if( n>pIter->iEndofDoclist ){
+    n = pIter->iEndofDoclist;
+  }
+
+  ASSERT_SZLEAF_OK(pIter->pLeaf);
+  while( 1 ){
+    i64 iDelta = 0;
+
+    if( eDetail==FTS5_DETAIL_NONE ){
+      /* todo */
+      if( i<n && a[i]==0 ){
+        i++;
+        if( i<n && a[i]==0 ) i++;
+      }
+    }else{
+      int nPos;
+      int bDummy;
+      i += fts5GetPoslistSize(&a[i], &nPos, &bDummy);
+      i += nPos;
+    }
+    if( i>=n ) break;
+    i += fts5GetVarint(&a[i], (u64*)&iDelta);
+    pIter->iRowid += iDelta;
+
+    /* If necessary, grow the pIter->aRowidOffset[] array. */
+    if( iRowidOffset>=pIter->nRowidOffset ){
+      int nNew = pIter->nRowidOffset + 8;
+      int *aNew = (int*)sqlite3_realloc(pIter->aRowidOffset, nNew*sizeof(int));
+      if( aNew==0 ){
+        p->rc = SQLITE_NOMEM;
+        break;
+      }
+      pIter->aRowidOffset = aNew;
+      pIter->nRowidOffset = nNew;
+    }
+
+    pIter->aRowidOffset[iRowidOffset++] = pIter->iLeafOffset;
+    pIter->iLeafOffset = i;
+  }
+  pIter->iRowidOffset = iRowidOffset;
+  fts5SegIterLoadNPos(p, pIter);
+}
+
+/*
+**
+*/
+static void fts5SegIterReverseNewPage(Fts5Index *p, Fts5SegIter *pIter){
+  assert( pIter->flags & FTS5_SEGITER_REVERSE );
+  assert( pIter->flags & FTS5_SEGITER_ONETERM );
+
+  fts5DataRelease(pIter->pLeaf);
+  pIter->pLeaf = 0;
+  while( p->rc==SQLITE_OK && pIter->iLeafPgno>pIter->iTermLeafPgno ){
+    Fts5Data *pNew;
+    pIter->iLeafPgno--;
+    pNew = fts5DataRead(p, FTS5_SEGMENT_ROWID(
+          pIter->pSeg->iSegid, pIter->iLeafPgno
+    ));
+    if( pNew ){
+      /* iTermLeafOffset may be equal to szLeaf if the term is the last
+      ** thing on the page - i.e. the first rowid is on the following page.
+      ** In this case leave pIter->pLeaf==0, this iterator is at EOF. */
+      if( pIter->iLeafPgno==pIter->iTermLeafPgno ){
+        assert( pIter->pLeaf==0 );
+        if( pIter->iTermLeafOffset<pNew->szLeaf ){
+          pIter->pLeaf = pNew;
+          pIter->iLeafOffset = pIter->iTermLeafOffset;
+        }
+      }else{
+        int iRowidOff;
+        iRowidOff = fts5LeafFirstRowidOff(pNew);
+        if( iRowidOff ){
+          pIter->pLeaf = pNew;
+          pIter->iLeafOffset = iRowidOff;
+        }
+      }
+
+      if( pIter->pLeaf ){
+        u8 *a = &pIter->pLeaf->p[pIter->iLeafOffset];
+        pIter->iLeafOffset += fts5GetVarint(a, (u64*)&pIter->iRowid);
+        break;
+      }else{
+        fts5DataRelease(pNew);
+      }
+    }
+  }
+
+  if( pIter->pLeaf ){
+    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
+    fts5SegIterReverseInitPage(p, pIter);
+  }
+}
+
+/*
+** Return true if the iterator passed as the second argument currently
+** points to a delete marker. A delete marker is an entry with a 0 byte
+** position-list.
+*/
+static int fts5MultiIterIsEmpty(Fts5Index *p, Fts5Iter *pIter){
+  Fts5SegIter *pSeg = &pIter->aSeg[pIter->aFirst[1].iFirst];
+  return (p->rc==SQLITE_OK && pSeg->pLeaf && pSeg->nPos==0);
+}
+
+/*
+** Advance iterator pIter to the next entry.
+**
+** This version of fts5SegIterNext() is only used by reverse iterators.
+*/
+static void fts5SegIterNext_Reverse(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter,             /* Iterator to advance */
+  int *pbUnused                   /* Unused */
+){
+  assert( pIter->flags & FTS5_SEGITER_REVERSE );
+  assert( pIter->pNextLeaf==0 );
+  UNUSED_PARAM(pbUnused);
+
+  if( pIter->iRowidOffset>0 ){
+    u8 *a = pIter->pLeaf->p;
+    int iOff;
+    i64 iDelta;
+
+    pIter->iRowidOffset--;
+    pIter->iLeafOffset = pIter->aRowidOffset[pIter->iRowidOffset];
+    fts5SegIterLoadNPos(p, pIter);
+    iOff = pIter->iLeafOffset;
+    if( p->pConfig->eDetail!=FTS5_DETAIL_NONE ){
+      iOff += pIter->nPos;
+    }
+    fts5GetVarint(&a[iOff], (u64*)&iDelta);
+    pIter->iRowid -= iDelta;
+  }else{
+    fts5SegIterReverseNewPage(p, pIter);
+  }
+}
+
+/*
+** Advance iterator pIter to the next entry.
+**
+** This version of fts5SegIterNext() is only used if detail=none and the
+** iterator is not a reverse direction iterator.
+*/
+static void fts5SegIterNext_None(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter,             /* Iterator to advance */
+  int *pbNewTerm                  /* OUT: Set for new term */
+){
+  int iOff;
+
+  assert( p->rc==SQLITE_OK );
+  assert( (pIter->flags & FTS5_SEGITER_REVERSE)==0 );
+  assert( p->pConfig->eDetail==FTS5_DETAIL_NONE );
+
+  ASSERT_SZLEAF_OK(pIter->pLeaf);
+  iOff = pIter->iLeafOffset;
+
+  /* Next entry is on the next page */
+  if( pIter->pSeg && iOff>=pIter->pLeaf->szLeaf ){
+    fts5SegIterNextPage(p, pIter);
+    if( p->rc || pIter->pLeaf==0 ) return;
+    pIter->iRowid = 0;
+    iOff = 4;
+  }
+
+  if( iOff<pIter->iEndofDoclist ){
+    /* Next entry is on the current page */
+    i64 iDelta;
+    iOff += sqlite3Fts5GetVarint(&pIter->pLeaf->p[iOff], (u64*)&iDelta);
+    pIter->iLeafOffset = iOff;
+    pIter->iRowid += iDelta;
+  }else if( (pIter->flags & FTS5_SEGITER_ONETERM)==0 ){
+    if( pIter->pSeg ){
+      int nKeep = 0;
+      if( iOff!=fts5LeafFirstTermOff(pIter->pLeaf) ){
+        iOff += fts5GetVarint32(&pIter->pLeaf->p[iOff], nKeep);
+      }
+      pIter->iLeafOffset = iOff;
+      fts5SegIterLoadTerm(p, pIter, nKeep);
+    }else{
+      const u8 *pList = 0;
+      const char *zTerm = 0;
+      int nList;
+      sqlite3Fts5HashScanNext(p->pHash);
+      sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);
+      if( pList==0 ) goto next_none_eof;
+      pIter->pLeaf->p = (u8*)pList;
+      pIter->pLeaf->nn = nList;
+      pIter->pLeaf->szLeaf = nList;
+      pIter->iEndofDoclist = nList;
+      sqlite3Fts5BufferSet(&p->rc,&pIter->term, (int)strlen(zTerm), (u8*)zTerm);
+      pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);
+    }
+
+    if( pbNewTerm ) *pbNewTerm = 1;
+  }else{
+    goto next_none_eof;
+  }
+
+  fts5SegIterLoadNPos(p, pIter);
+
+  return;
+ next_none_eof:
+  fts5DataRelease(pIter->pLeaf);
+  pIter->pLeaf = 0;
+}
+
+
+/*
+** Advance iterator pIter to the next entry. 
+**
+** If an error occurs, Fts5Index.rc is set to an appropriate error code. It 
+** is not considered an error if the iterator reaches EOF. If an error has 
+** already occurred when this function is called, it is a no-op.
+*/
+static void fts5SegIterNext(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter,             /* Iterator to advance */
+  int *pbNewTerm                  /* OUT: Set for new term */
+){
+  Fts5Data *pLeaf = pIter->pLeaf;
+  int iOff;
+  int bNewTerm = 0;
+  int nKeep = 0;
+  u8 *a;
+  int n;
+
+  assert( pbNewTerm==0 || *pbNewTerm==0 );
+  assert( p->pConfig->eDetail!=FTS5_DETAIL_NONE );
+
+  /* Search for the end of the position list within the current page. */
+  a = pLeaf->p;
+  n = pLeaf->szLeaf;
+
+  ASSERT_SZLEAF_OK(pLeaf);
+  iOff = pIter->iLeafOffset + pIter->nPos;
+
+  if( iOff<n ){
+    /* The next entry is on the current page. */
+    assert_nc( iOff<=pIter->iEndofDoclist );
+    if( iOff>=pIter->iEndofDoclist ){
+      bNewTerm = 1;
+      if( iOff!=fts5LeafFirstTermOff(pLeaf) ){
+        iOff += fts5GetVarint32(&a[iOff], nKeep);
+      }
+    }else{
+      u64 iDelta;
+      iOff += sqlite3Fts5GetVarint(&a[iOff], &iDelta);
+      pIter->iRowid += iDelta;
+      assert_nc( iDelta>0 );
+    }
+    pIter->iLeafOffset = iOff;
+
+  }else if( pIter->pSeg==0 ){
+    const u8 *pList = 0;
+    const char *zTerm = 0;
+    int nList = 0;
+    assert( (pIter->flags & FTS5_SEGITER_ONETERM) || pbNewTerm );
+    if( 0==(pIter->flags & FTS5_SEGITER_ONETERM) ){
+      sqlite3Fts5HashScanNext(p->pHash);
+      sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);
+    }
+    if( pList==0 ){
+      fts5DataRelease(pIter->pLeaf);
+      pIter->pLeaf = 0;
+    }else{
+      pIter->pLeaf->p = (u8*)pList;
+      pIter->pLeaf->nn = nList;
+      pIter->pLeaf->szLeaf = nList;
+      pIter->iEndofDoclist = nList+1;
+      sqlite3Fts5BufferSet(&p->rc, &pIter->term, (int)strlen(zTerm),
+          (u8*)zTerm);
+      pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);
+      *pbNewTerm = 1;
+    }
+  }else{
+    iOff = 0;
+    /* Next entry is not on the current page */
+    while( iOff==0 ){
+      fts5SegIterNextPage(p, pIter);
+      pLeaf = pIter->pLeaf;
+      if( pLeaf==0 ) break;
+      ASSERT_SZLEAF_OK(pLeaf);
+      if( (iOff = fts5LeafFirstRowidOff(pLeaf)) && iOff<pLeaf->szLeaf ){
+        iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);
+        pIter->iLeafOffset = iOff;
+
+        if( pLeaf->nn>pLeaf->szLeaf ){
+          pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
+              &pLeaf->p[pLeaf->szLeaf], pIter->iEndofDoclist
+              );
+        }
+
+      }
+      else if( pLeaf->nn>pLeaf->szLeaf ){
+        pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(
+            &pLeaf->p[pLeaf->szLeaf], iOff
+            );
+        pIter->iLeafOffset = iOff;
+        pIter->iEndofDoclist = iOff;
+        bNewTerm = 1;
+      }
+      assert_nc( iOff<pLeaf->szLeaf );
+      if( iOff>pLeaf->szLeaf ){
+        p->rc = FTS5_CORRUPT;
+        return;
+      }
+    }
+  }
+
+  /* Check if the iterator is now at EOF. If so, return early. */
+  if( pIter->pLeaf ){
+    if( bNewTerm ){
+      if( pIter->flags & FTS5_SEGITER_ONETERM ){
+        fts5DataRelease(pIter->pLeaf);
+        pIter->pLeaf = 0;
+      }else{
+        fts5SegIterLoadTerm(p, pIter, nKeep);
+        fts5SegIterLoadNPos(p, pIter);
+        if( pbNewTerm ) *pbNewTerm = 1;
+      }
+    }else{
+      /* The following could be done by calling fts5SegIterLoadNPos(). But
+      ** this block is particularly performance critical, so equivalent
+      ** code is inlined. 
+      **
+      ** Later: Switched back to fts5SegIterLoadNPos() because it supports
+      ** detail=none mode. Not ideal.
+      */
+      int nSz;
+      assert( p->rc==SQLITE_OK );
+      fts5FastGetVarint32(pIter->pLeaf->p, pIter->iLeafOffset, nSz);
+      pIter->bDel = (nSz & 0x0001);
+      pIter->nPos = nSz>>1;
+      assert_nc( pIter->nPos>=0 );
+    }
+  }
+}
+
+#define SWAPVAL(T, a, b) { T tmp; tmp=a; a=b; b=tmp; }
+
+#define fts5IndexSkipVarint(a, iOff) {            \
+  int iEnd = iOff+9;                              \
+  while( (a[iOff++] & 0x80) && iOff<iEnd );       \
+}
+
+/*
+** Iterator pIter currently points to the first rowid in a doclist. This
+** function sets the iterator up so that iterates in reverse order through
+** the doclist.
+*/
+static void fts5SegIterReverse(Fts5Index *p, Fts5SegIter *pIter){
+  Fts5DlidxIter *pDlidx = pIter->pDlidx;
+  Fts5Data *pLast = 0;
+  int pgnoLast = 0;
+
+  if( pDlidx ){
+    int iSegid = pIter->pSeg->iSegid;
+    pgnoLast = fts5DlidxIterPgno(pDlidx);
+    pLast = fts5DataRead(p, FTS5_SEGMENT_ROWID(iSegid, pgnoLast));
+  }else{
+    Fts5Data *pLeaf = pIter->pLeaf;         /* Current leaf data */
+
+    /* Currently, Fts5SegIter.iLeafOffset points to the first byte of
+    ** position-list content for the current rowid. Back it up so that it
+    ** points to the start of the position-list size field. */
+    int iPoslist;
+    if( pIter->iTermLeafPgno==pIter->iLeafPgno ){
+      iPoslist = pIter->iTermLeafOffset;
+    }else{
+      iPoslist = 4;
+    }
+    fts5IndexSkipVarint(pLeaf->p, iPoslist);
+    pIter->iLeafOffset = iPoslist;
+
+    /* If this condition is true then the largest rowid for the current
+    ** term may not be stored on the current page. So search forward to
+    ** see where said rowid really is.  */
+    if( pIter->iEndofDoclist>=pLeaf->szLeaf ){
+      int pgno;
+      Fts5StructureSegment *pSeg = pIter->pSeg;
+
+      /* The last rowid in the doclist may not be on the current page. Search
+      ** forward to find the page containing the last rowid.  */
+      for(pgno=pIter->iLeafPgno+1; !p->rc && pgno<=pSeg->pgnoLast; pgno++){
+        i64 iAbs = FTS5_SEGMENT_ROWID(pSeg->iSegid, pgno);
+        Fts5Data *pNew = fts5DataRead(p, iAbs);
+        if( pNew ){
+          int iRowid, bTermless;
+          iRowid = fts5LeafFirstRowidOff(pNew);
+          bTermless = fts5LeafIsTermless(pNew);
+          if( iRowid ){
+            SWAPVAL(Fts5Data*, pNew, pLast);
+            pgnoLast = pgno;
+          }
+          fts5DataRelease(pNew);
+          if( bTermless==0 ) break;
+        }
+      }
+    }
+  }
+
+  /* If pLast is NULL at this point, then the last rowid for this doclist
+  ** lies on the page currently indicated by the iterator. In this case 
+  ** pIter->iLeafOffset is already set to point to the position-list size
+  ** field associated with the first relevant rowid on the page.
+  **
+  ** Or, if pLast is non-NULL, then it is the page that contains the last
+  ** rowid. In this case configure the iterator so that it points to the
+  ** first rowid on this page.
+  */
+  if( pLast ){
+    int iOff;
+    fts5DataRelease(pIter->pLeaf);
+    pIter->pLeaf = pLast;
+    pIter->iLeafPgno = pgnoLast;
+    iOff = fts5LeafFirstRowidOff(pLast);
+    iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);
+    pIter->iLeafOffset = iOff;
+
+    if( fts5LeafIsTermless(pLast) ){
+      pIter->iEndofDoclist = pLast->nn+1;
+    }else{
+      pIter->iEndofDoclist = fts5LeafFirstTermOff(pLast);
+    }
+
+  }
+
+  fts5SegIterReverseInitPage(p, pIter);
+}
+
+/*
+** Iterator pIter currently points to the first rowid of a doclist.
+** There is a doclist-index associated with the final term on the current 
+** page. If the current term is the last term on the page, load the 
+** doclist-index from disk and initialize an iterator at (pIter->pDlidx).
+*/
+static void fts5SegIterLoadDlidx(Fts5Index *p, Fts5SegIter *pIter){
+  int iSeg = pIter->pSeg->iSegid;
+  int bRev = (pIter->flags & FTS5_SEGITER_REVERSE);
+  Fts5Data *pLeaf = pIter->pLeaf; /* Current leaf data */
+
+  assert( pIter->flags & FTS5_SEGITER_ONETERM );
+  assert( pIter->pDlidx==0 );
+
+  /* Check if the current doclist ends on this page. If it does, return
+  ** early without loading the doclist-index (as it belongs to a different
+  ** term. */
+  if( pIter->iTermLeafPgno==pIter->iLeafPgno 
+   && pIter->iEndofDoclist<pLeaf->szLeaf 
+  ){
+    return;
+  }
+
+  pIter->pDlidx = fts5DlidxIterInit(p, bRev, iSeg, pIter->iTermLeafPgno);
+}
+
+/*
+** The iterator object passed as the second argument currently contains
+** no valid values except for the Fts5SegIter.pLeaf member variable. This
+** function searches the leaf page for a term matching (pTerm/nTerm).
+**
+** If the specified term is found on the page, then the iterator is left
+** pointing to it. If argument bGe is zero and the term is not found,
+** the iterator is left pointing at EOF.
+**
+** If bGe is non-zero and the specified term is not found, then the
+** iterator is left pointing to the smallest term in the segment that
+** is larger than the specified term, even if this term is not on the
+** current page.
+*/
+static void fts5LeafSeek(
+  Fts5Index *p,                   /* Leave any error code here */
+  int bGe,                        /* True for a >= search */
+  Fts5SegIter *pIter,             /* Iterator to seek */
+  const u8 *pTerm, int nTerm      /* Term to search for */
+){
+  int iOff;
+  const u8 *a = pIter->pLeaf->p;
+  int szLeaf = pIter->pLeaf->szLeaf;
+  int n = pIter->pLeaf->nn;
+
+  int nMatch = 0;
+  int nKeep = 0;
+  int nNew = 0;
+  int iTermOff;
+  int iPgidx;                     /* Current offset in pgidx */
+  int bEndOfPage = 0;
+
+  assert( p->rc==SQLITE_OK );
+
+  iPgidx = szLeaf;
+  iPgidx += fts5GetVarint32(&a[iPgidx], iTermOff);
+  iOff = iTermOff;
+  if( iOff>n ){
+    p->rc = FTS5_CORRUPT;
+    return;
+  }
+
+  while( 1 ){
+
+    /* Figure out how many new bytes are in this term */
+    fts5FastGetVarint32(a, iOff, nNew);
+    if( nKeep<nMatch ){
+      goto search_failed;
+    }
+
+    assert( nKeep>=nMatch );
+    if( nKeep==nMatch ){
+      int nCmp;
+      int i;
+      nCmp = MIN(nNew, nTerm-nMatch);
+      for(i=0; i<nCmp; i++){
+        if( a[iOff+i]!=pTerm[nMatch+i] ) break;
+      }
+      nMatch += i;
+
+      if( nTerm==nMatch ){
+        if( i==nNew ){
+          goto search_success;
+        }else{
+          goto search_failed;
+        }
+      }else if( i<nNew && a[iOff+i]>pTerm[nMatch] ){
+        goto search_failed;
+      }
+    }
+
+    if( iPgidx>=n ){
+      bEndOfPage = 1;
+      break;
+    }
+
+    iPgidx += fts5GetVarint32(&a[iPgidx], nKeep);
+    iTermOff += nKeep;
+    iOff = iTermOff;
+
+    /* Read the nKeep field of the next term. */
+    fts5FastGetVarint32(a, iOff, nKeep);
+  }
+
+ search_failed:
+  if( bGe==0 ){
+    fts5DataRelease(pIter->pLeaf);
+    pIter->pLeaf = 0;
+    return;
+  }else if( bEndOfPage ){
+    do {
+      fts5SegIterNextPage(p, pIter);
+      if( pIter->pLeaf==0 ) return;
+      a = pIter->pLeaf->p;
+      if( fts5LeafIsTermless(pIter->pLeaf)==0 ){
+        iPgidx = pIter->pLeaf->szLeaf;
+        iPgidx += fts5GetVarint32(&pIter->pLeaf->p[iPgidx], iOff);
+        if( iOff<4 || iOff>=pIter->pLeaf->szLeaf ){
+          p->rc = FTS5_CORRUPT;
+        }else{
+          nKeep = 0;
+          iTermOff = iOff;
+          n = pIter->pLeaf->nn;
+          iOff += fts5GetVarint32(&a[iOff], nNew);
+          break;
+        }
+      }
+    }while( 1 );
+  }
+
+ search_success:
+
+  pIter->iLeafOffset = iOff + nNew;
+  pIter->iTermLeafOffset = pIter->iLeafOffset;
+  pIter->iTermLeafPgno = pIter->iLeafPgno;
+
+  fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);
+  fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);
+
+  if( iPgidx>=n ){
+    pIter->iEndofDoclist = pIter->pLeaf->nn+1;
+  }else{
+    int nExtra;
+    iPgidx += fts5GetVarint32(&a[iPgidx], nExtra);
+    pIter->iEndofDoclist = iTermOff + nExtra;
+  }
+  pIter->iPgidxOff = iPgidx;
+
+  fts5SegIterLoadRowid(p, pIter);
+  fts5SegIterLoadNPos(p, pIter);
+}
+
+static sqlite3_stmt *fts5IdxSelectStmt(Fts5Index *p){
+  if( p->pIdxSelect==0 ){
+    Fts5Config *pConfig = p->pConfig;
+    fts5IndexPrepareStmt(p, &p->pIdxSelect, sqlite3_mprintf(
+          "SELECT pgno FROM '%q'.'%q_idx' WHERE "
+          "segid=? AND term<=? ORDER BY term DESC LIMIT 1",
+          pConfig->zDb, pConfig->zName
+    ));
+  }
+  return p->pIdxSelect;
+}
+
+/*
+** Initialize the object pIter to point to term pTerm/nTerm within segment
+** pSeg. If there is no such term in the index, the iterator is set to EOF.
+**
+** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
+** an error has already occurred when this function is called, it is a no-op.
+*/
+static void fts5SegIterSeekInit(
+  Fts5Index *p,                   /* FTS5 backend */
+  const u8 *pTerm, int nTerm,     /* Term to seek to */
+  int flags,                      /* Mask of FTS5INDEX_XXX flags */
+  Fts5StructureSegment *pSeg,     /* Description of segment */
+  Fts5SegIter *pIter              /* Object to populate */
+){
+  int iPg = 1;
+  int bGe = (flags & FTS5INDEX_QUERY_SCAN);
+  int bDlidx = 0;                 /* True if there is a doclist-index */
+  sqlite3_stmt *pIdxSelect = 0;
+
+  assert( bGe==0 || (flags & FTS5INDEX_QUERY_DESC)==0 );
+  assert( pTerm && nTerm );
+  memset(pIter, 0, sizeof(*pIter));
+  pIter->pSeg = pSeg;
+
+  /* This block sets stack variable iPg to the leaf page number that may
+  ** contain term (pTerm/nTerm), if it is present in the segment. */
+  pIdxSelect = fts5IdxSelectStmt(p);
+  if( p->rc ) return;
+  sqlite3_bind_int(pIdxSelect, 1, pSeg->iSegid);
+  sqlite3_bind_blob(pIdxSelect, 2, pTerm, nTerm, SQLITE_STATIC);
+  if( SQLITE_ROW==sqlite3_step(pIdxSelect) ){
+    i64 val = sqlite3_column_int(pIdxSelect, 0);
+    iPg = (int)(val>>1);
+    bDlidx = (val & 0x0001);
+  }
+  p->rc = sqlite3_reset(pIdxSelect);
+
+  if( iPg<pSeg->pgnoFirst ){
+    iPg = pSeg->pgnoFirst;
+    bDlidx = 0;
+  }
+
+  pIter->iLeafPgno = iPg - 1;
+  fts5SegIterNextPage(p, pIter);
+
+  if( pIter->pLeaf ){
+    fts5LeafSeek(p, bGe, pIter, pTerm, nTerm);
+  }
+
+  if( p->rc==SQLITE_OK && bGe==0 ){
+    pIter->flags |= FTS5_SEGITER_ONETERM;
+    if( pIter->pLeaf ){
+      if( flags & FTS5INDEX_QUERY_DESC ){
+        pIter->flags |= FTS5_SEGITER_REVERSE;
+      }
+      if( bDlidx ){
+        fts5SegIterLoadDlidx(p, pIter);
+      }
+      if( flags & FTS5INDEX_QUERY_DESC ){
+        fts5SegIterReverse(p, pIter);
+      }
+    }
+  }
+
+  fts5SegIterSetNext(p, pIter);
+
+  /* Either:
+  **
+  **   1) an error has occurred, or
+  **   2) the iterator points to EOF, or
+  **   3) the iterator points to an entry with term (pTerm/nTerm), or
+  **   4) the FTS5INDEX_QUERY_SCAN flag was set and the iterator points
+  **      to an entry with a term greater than or equal to (pTerm/nTerm).
+  */
+  assert( p->rc!=SQLITE_OK                                          /* 1 */
+   || pIter->pLeaf==0                                               /* 2 */
+   || fts5BufferCompareBlob(&pIter->term, pTerm, nTerm)==0          /* 3 */
+   || (bGe && fts5BufferCompareBlob(&pIter->term, pTerm, nTerm)>0)  /* 4 */
+  );
+}
+
+/*
+** Initialize the object pIter to point to term pTerm/nTerm within the
+** in-memory hash table. If there is no such term in the hash-table, the 
+** iterator is set to EOF.
+**
+** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 
+** an error has already occurred when this function is called, it is a no-op.
+*/
+static void fts5SegIterHashInit(
+  Fts5Index *p,                   /* FTS5 backend */
+  const u8 *pTerm, int nTerm,     /* Term to seek to */
+  int flags,                      /* Mask of FTS5INDEX_XXX flags */
+  Fts5SegIter *pIter              /* Object to populate */
+){
+  const u8 *pList = 0;
+  int nList = 0;
+  const u8 *z = 0;
+  int n = 0;
+
+  assert( p->pHash );
+  assert( p->rc==SQLITE_OK );
+
+  if( pTerm==0 || (flags & FTS5INDEX_QUERY_SCAN) ){
+    p->rc = sqlite3Fts5HashScanInit(p->pHash, (const char*)pTerm, nTerm);
+    sqlite3Fts5HashScanEntry(p->pHash, (const char**)&z, &pList, &nList);
+    n = (z ? (int)strlen((const char*)z) : 0);
+  }else{
+    pIter->flags |= FTS5_SEGITER_ONETERM;
+    sqlite3Fts5HashQuery(p->pHash, (const char*)pTerm, nTerm, &pList, &nList);
+    z = pTerm;
+    n = nTerm;
+  }
+
+  if( pList ){
+    Fts5Data *pLeaf;
+    sqlite3Fts5BufferSet(&p->rc, &pIter->term, n, z);
+    pLeaf = fts5IdxMalloc(p, sizeof(Fts5Data));
+    if( pLeaf==0 ) return;
+    pLeaf->p = (u8*)pList;
+    pLeaf->nn = pLeaf->szLeaf = nList;
+    pIter->pLeaf = pLeaf;
+    pIter->iLeafOffset = fts5GetVarint(pLeaf->p, (u64*)&pIter->iRowid);
+    pIter->iEndofDoclist = pLeaf->nn;
+
+    if( flags & FTS5INDEX_QUERY_DESC ){
+      pIter->flags |= FTS5_SEGITER_REVERSE;
+      fts5SegIterReverseInitPage(p, pIter);
+    }else{
+      fts5SegIterLoadNPos(p, pIter);
+    }
+  }
+
+  fts5SegIterSetNext(p, pIter);
+}
+
+/*
+** Zero the iterator passed as the only argument.
+*/
+static void fts5SegIterClear(Fts5SegIter *pIter){
+  fts5BufferFree(&pIter->term);
+  fts5DataRelease(pIter->pLeaf);
+  fts5DataRelease(pIter->pNextLeaf);
+  fts5DlidxIterFree(pIter->pDlidx);
+  sqlite3_free(pIter->aRowidOffset);
+  memset(pIter, 0, sizeof(Fts5SegIter));
+}
+
+#ifdef SQLITE_DEBUG
+
+/*
+** This function is used as part of the big assert() procedure implemented by
+** fts5AssertMultiIterSetup(). It ensures that the result currently stored
+** in *pRes is the correct result of comparing the current positions of the
+** two iterators.
+*/
+static void fts5AssertComparisonResult(
+  Fts5Iter *pIter, 
+  Fts5SegIter *p1,
+  Fts5SegIter *p2,
+  Fts5CResult *pRes
+){
+  int i1 = p1 - pIter->aSeg;
+  int i2 = p2 - pIter->aSeg;
+
+  if( p1->pLeaf || p2->pLeaf ){
+    if( p1->pLeaf==0 ){
+      assert( pRes->iFirst==i2 );
+    }else if( p2->pLeaf==0 ){
+      assert( pRes->iFirst==i1 );
+    }else{
+      int nMin = MIN(p1->term.n, p2->term.n);
+      int res = memcmp(p1->term.p, p2->term.p, nMin);
+      if( res==0 ) res = p1->term.n - p2->term.n;
+
+      if( res==0 ){
+        assert( pRes->bTermEq==1 );
+        assert( p1->iRowid!=p2->iRowid );
+        res = ((p1->iRowid > p2->iRowid)==pIter->bRev) ? -1 : 1;
+      }else{
+        assert( pRes->bTermEq==0 );
+      }
+
+      if( res<0 ){
+        assert( pRes->iFirst==i1 );
+      }else{
+        assert( pRes->iFirst==i2 );
+      }
+    }
+  }
+}
+
+/*
+** This function is a no-op unless SQLITE_DEBUG is defined when this module
+** is compiled. In that case, this function is essentially an assert() 
+** statement used to verify that the contents of the pIter->aFirst[] array
+** are correct.
+*/
+static void fts5AssertMultiIterSetup(Fts5Index *p, Fts5Iter *pIter){
+  if( p->rc==SQLITE_OK ){
+    Fts5SegIter *pFirst = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
+    int i;
+
+    assert( (pFirst->pLeaf==0)==pIter->base.bEof );
+
+    /* Check that pIter->iSwitchRowid is set correctly. */
+    for(i=0; i<pIter->nSeg; i++){
+      Fts5SegIter *p1 = &pIter->aSeg[i];
+      assert( p1==pFirst 
+           || p1->pLeaf==0 
+           || fts5BufferCompare(&pFirst->term, &p1->term) 
+           || p1->iRowid==pIter->iSwitchRowid
+           || (p1->iRowid<pIter->iSwitchRowid)==pIter->bRev
+      );
+    }
+
+    for(i=0; i<pIter->nSeg; i+=2){
+      Fts5SegIter *p1 = &pIter->aSeg[i];
+      Fts5SegIter *p2 = &pIter->aSeg[i+1];
+      Fts5CResult *pRes = &pIter->aFirst[(pIter->nSeg + i) / 2];
+      fts5AssertComparisonResult(pIter, p1, p2, pRes);
+    }
+
+    for(i=1; i<(pIter->nSeg / 2); i+=2){
+      Fts5SegIter *p1 = &pIter->aSeg[ pIter->aFirst[i*2].iFirst ];
+      Fts5SegIter *p2 = &pIter->aSeg[ pIter->aFirst[i*2+1].iFirst ];
+      Fts5CResult *pRes = &pIter->aFirst[i];
+      fts5AssertComparisonResult(pIter, p1, p2, pRes);
+    }
+  }
+}
+#else
+# define fts5AssertMultiIterSetup(x,y)
+#endif
+
+/*
+** Do the comparison necessary to populate pIter->aFirst[iOut].
+**
+** If the returned value is non-zero, then it is the index of an entry
+** in the pIter->aSeg[] array that is (a) not at EOF, and (b) pointing
+** to a key that is a duplicate of another, higher priority, 
+** segment-iterator in the pSeg->aSeg[] array.
+*/
+static int fts5MultiIterDoCompare(Fts5Iter *pIter, int iOut){
+  int i1;                         /* Index of left-hand Fts5SegIter */
+  int i2;                         /* Index of right-hand Fts5SegIter */
+  int iRes;
+  Fts5SegIter *p1;                /* Left-hand Fts5SegIter */
+  Fts5SegIter *p2;                /* Right-hand Fts5SegIter */
+  Fts5CResult *pRes = &pIter->aFirst[iOut];
+
+  assert( iOut<pIter->nSeg && iOut>0 );
+  assert( pIter->bRev==0 || pIter->bRev==1 );
+
+  if( iOut>=(pIter->nSeg/2) ){
+    i1 = (iOut - pIter->nSeg/2) * 2;
+    i2 = i1 + 1;
+  }else{
+    i1 = pIter->aFirst[iOut*2].iFirst;
+    i2 = pIter->aFirst[iOut*2+1].iFirst;
+  }
+  p1 = &pIter->aSeg[i1];
+  p2 = &pIter->aSeg[i2];
+
+  pRes->bTermEq = 0;
+  if( p1->pLeaf==0 ){           /* If p1 is at EOF */
+    iRes = i2;
+  }else if( p2->pLeaf==0 ){     /* If p2 is at EOF */
+    iRes = i1;
+  }else{
+    int res = fts5BufferCompare(&p1->term, &p2->term);
+    if( res==0 ){
+      assert( i2>i1 );
+      assert( i2!=0 );
+      pRes->bTermEq = 1;
+      if( p1->iRowid==p2->iRowid ){
+        p1->bDel = p2->bDel;
+        return i2;
+      }
+      res = ((p1->iRowid > p2->iRowid)==pIter->bRev) ? -1 : +1;
+    }
+    assert( res!=0 );
+    if( res<0 ){
+      iRes = i1;
+    }else{
+      iRes = i2;
+    }
+  }
+
+  pRes->iFirst = (u16)iRes;
+  return 0;
+}
+
+/*
+** Move the seg-iter so that it points to the first rowid on page iLeafPgno.
+** It is an error if leaf iLeafPgno does not exist or contains no rowids.
+*/
+static void fts5SegIterGotoPage(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter,             /* Iterator to advance */
+  int iLeafPgno
+){
+  assert( iLeafPgno>pIter->iLeafPgno );
+
+  if( iLeafPgno>pIter->pSeg->pgnoLast ){
+    p->rc = FTS5_CORRUPT;
+  }else{
+    fts5DataRelease(pIter->pNextLeaf);
+    pIter->pNextLeaf = 0;
+    pIter->iLeafPgno = iLeafPgno-1;
+    fts5SegIterNextPage(p, pIter);
+    assert( p->rc!=SQLITE_OK || pIter->iLeafPgno==iLeafPgno );
+
+    if( p->rc==SQLITE_OK ){
+      int iOff;
+      u8 *a = pIter->pLeaf->p;
+      int n = pIter->pLeaf->szLeaf;
+
+      iOff = fts5LeafFirstRowidOff(pIter->pLeaf);
+      if( iOff<4 || iOff>=n ){
+        p->rc = FTS5_CORRUPT;
+      }else{
+        iOff += fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);
+        pIter->iLeafOffset = iOff;
+        fts5SegIterLoadNPos(p, pIter);
+      }
+    }
+  }
+}
+
+/*
+** Advance the iterator passed as the second argument until it is at or 
+** past rowid iFrom. Regardless of the value of iFrom, the iterator is
+** always advanced at least once.
+*/
+static void fts5SegIterNextFrom(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegIter *pIter,             /* Iterator to advance */
+  i64 iMatch                      /* Advance iterator at least this far */
+){
+  int bRev = (pIter->flags & FTS5_SEGITER_REVERSE);
+  Fts5DlidxIter *pDlidx = pIter->pDlidx;
+  int iLeafPgno = pIter->iLeafPgno;
+  int bMove = 1;
+
+  assert( pIter->flags & FTS5_SEGITER_ONETERM );
+  assert( pIter->pDlidx );
+  assert( pIter->pLeaf );
+
+  if( bRev==0 ){
+    while( !fts5DlidxIterEof(p, pDlidx) && iMatch>fts5DlidxIterRowid(pDlidx) ){
+      iLeafPgno = fts5DlidxIterPgno(pDlidx);
+      fts5DlidxIterNext(p, pDlidx);
+    }
+    assert_nc( iLeafPgno>=pIter->iLeafPgno || p->rc );
+    if( iLeafPgno>pIter->iLeafPgno ){
+      fts5SegIterGotoPage(p, pIter, iLeafPgno);
+      bMove = 0;
+    }
+  }else{
+    assert( pIter->pNextLeaf==0 );
+    assert( iMatch<pIter->iRowid );
+    while( !fts5DlidxIterEof(p, pDlidx) && iMatch<fts5DlidxIterRowid(pDlidx) ){
+      fts5DlidxIterPrev(p, pDlidx);
+    }
+    iLeafPgno = fts5DlidxIterPgno(pDlidx);
+
+    assert( fts5DlidxIterEof(p, pDlidx) || iLeafPgno<=pIter->iLeafPgno );
+
+    if( iLeafPgno<pIter->iLeafPgno ){
+      pIter->iLeafPgno = iLeafPgno+1;
+      fts5SegIterReverseNewPage(p, pIter);
+      bMove = 0;
+    }
+  }
+
+  do{
+    if( bMove && p->rc==SQLITE_OK ) pIter->xNext(p, pIter, 0);
+    if( pIter->pLeaf==0 ) break;
+    if( bRev==0 && pIter->iRowid>=iMatch ) break;
+    if( bRev!=0 && pIter->iRowid<=iMatch ) break;
+    bMove = 1;
+  }while( p->rc==SQLITE_OK );
+}
+
+
+/*
+** Free the iterator object passed as the second argument.
+*/
+static void fts5MultiIterFree(Fts5Iter *pIter){
+  if( pIter ){
+    int i;
+    for(i=0; i<pIter->nSeg; i++){
+      fts5SegIterClear(&pIter->aSeg[i]);
+    }
+    fts5StructureRelease(pIter->pStruct);
+    fts5BufferFree(&pIter->poslist);
+    sqlite3_free(pIter);
+  }
+}
+
+static void fts5MultiIterAdvanced(
+  Fts5Index *p,                   /* FTS5 backend to iterate within */
+  Fts5Iter *pIter,                /* Iterator to update aFirst[] array for */
+  int iChanged,                   /* Index of sub-iterator just advanced */
+  int iMinset                     /* Minimum entry in aFirst[] to set */
+){
+  int i;
+  for(i=(pIter->nSeg+iChanged)/2; i>=iMinset && p->rc==SQLITE_OK; i=i/2){
+    int iEq;
+    if( (iEq = fts5MultiIterDoCompare(pIter, i)) ){
+      Fts5SegIter *pSeg = &pIter->aSeg[iEq];
+      assert( p->rc==SQLITE_OK );
+      pSeg->xNext(p, pSeg, 0);
+      i = pIter->nSeg + iEq;
+    }
+  }
+}
+
+/*
+** Sub-iterator iChanged of iterator pIter has just been advanced. It still
+** points to the same term though - just a different rowid. This function
+** attempts to update the contents of the pIter->aFirst[] accordingly.
+** If it does so successfully, 0 is returned. Otherwise 1.
+**
+** If non-zero is returned, the caller should call fts5MultiIterAdvanced()
+** on the iterator instead. That function does the same as this one, except
+** that it deals with more complicated cases as well.
+*/ 
+static int fts5MultiIterAdvanceRowid(
+  Fts5Iter *pIter,                /* Iterator to update aFirst[] array for */
+  int iChanged,                   /* Index of sub-iterator just advanced */
+  Fts5SegIter **ppFirst
+){
+  Fts5SegIter *pNew = &pIter->aSeg[iChanged];
+
+  if( pNew->iRowid==pIter->iSwitchRowid
+   || (pNew->iRowid<pIter->iSwitchRowid)==pIter->bRev
+  ){
+    int i;
+    Fts5SegIter *pOther = &pIter->aSeg[iChanged ^ 0x0001];
+    pIter->iSwitchRowid = pIter->bRev ? SMALLEST_INT64 : LARGEST_INT64;
+    for(i=(pIter->nSeg+iChanged)/2; 1; i=i/2){
+      Fts5CResult *pRes = &pIter->aFirst[i];
+
+      assert( pNew->pLeaf );
+      assert( pRes->bTermEq==0 || pOther->pLeaf );
+
+      if( pRes->bTermEq ){
+        if( pNew->iRowid==pOther->iRowid ){
+          return 1;
+        }else if( (pOther->iRowid>pNew->iRowid)==pIter->bRev ){
+          pIter->iSwitchRowid = pOther->iRowid;
+          pNew = pOther;
+        }else if( (pOther->iRowid>pIter->iSwitchRowid)==pIter->bRev ){
+          pIter->iSwitchRowid = pOther->iRowid;
+        }
+      }
+      pRes->iFirst = (u16)(pNew - pIter->aSeg);
+      if( i==1 ) break;
+
+      pOther = &pIter->aSeg[ pIter->aFirst[i ^ 0x0001].iFirst ];
+    }
+  }
+
+  *ppFirst = pNew;
+  return 0;
+}
+
+/*
+** Set the pIter->bEof variable based on the state of the sub-iterators.
+*/
+static void fts5MultiIterSetEof(Fts5Iter *pIter){
+  Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
+  pIter->base.bEof = pSeg->pLeaf==0;
+  pIter->iSwitchRowid = pSeg->iRowid;
+}
+
+/*
+** Move the iterator to the next entry. 
+**
+** If an error occurs, an error code is left in Fts5Index.rc. It is not 
+** considered an error if the iterator reaches EOF, or if it is already at 
+** EOF when this function is called.
+*/
+static void fts5MultiIterNext(
+  Fts5Index *p, 
+  Fts5Iter *pIter,
+  int bFrom,                      /* True if argument iFrom is valid */
+  i64 iFrom                       /* Advance at least as far as this */
+){
+  int bUseFrom = bFrom;
+  while( p->rc==SQLITE_OK ){
+    int iFirst = pIter->aFirst[1].iFirst;
+    int bNewTerm = 0;
+    Fts5SegIter *pSeg = &pIter->aSeg[iFirst];
+    assert( p->rc==SQLITE_OK );
+    if( bUseFrom && pSeg->pDlidx ){
+      fts5SegIterNextFrom(p, pSeg, iFrom);
+    }else{
+      pSeg->xNext(p, pSeg, &bNewTerm);
+    }
+
+    if( pSeg->pLeaf==0 || bNewTerm 
+     || fts5MultiIterAdvanceRowid(pIter, iFirst, &pSeg)
+    ){
+      fts5MultiIterAdvanced(p, pIter, iFirst, 1);
+      fts5MultiIterSetEof(pIter);
+      pSeg = &pIter->aSeg[pIter->aFirst[1].iFirst];
+      if( pSeg->pLeaf==0 ) return;
+    }
+
+    fts5AssertMultiIterSetup(p, pIter);
+    assert( pSeg==&pIter->aSeg[pIter->aFirst[1].iFirst] && pSeg->pLeaf );
+    if( pIter->bSkipEmpty==0 || pSeg->nPos ){
+      pIter->xSetOutputs(pIter, pSeg);
+      return;
+    }
+    bUseFrom = 0;
+  }
+}
+
+static void fts5MultiIterNext2(
+  Fts5Index *p, 
+  Fts5Iter *pIter,
+  int *pbNewTerm                  /* OUT: True if *might* be new term */
+){
+  assert( pIter->bSkipEmpty );
+  if( p->rc==SQLITE_OK ){
+    do {
+      int iFirst = pIter->aFirst[1].iFirst;
+      Fts5SegIter *pSeg = &pIter->aSeg[iFirst];
+      int bNewTerm = 0;
+
+      assert( p->rc==SQLITE_OK );
+      pSeg->xNext(p, pSeg, &bNewTerm);
+      if( pSeg->pLeaf==0 || bNewTerm 
+       || fts5MultiIterAdvanceRowid(pIter, iFirst, &pSeg)
+      ){
+        fts5MultiIterAdvanced(p, pIter, iFirst, 1);
+        fts5MultiIterSetEof(pIter);
+        *pbNewTerm = 1;
+      }else{
+        *pbNewTerm = 0;
+      }
+      fts5AssertMultiIterSetup(p, pIter);
+
+    }while( fts5MultiIterIsEmpty(p, pIter) );
+  }
+}
+
+static void fts5IterSetOutputs_Noop(Fts5Iter *pUnused1, Fts5SegIter *pUnused2){
+  UNUSED_PARAM2(pUnused1, pUnused2);
+}
+
+static Fts5Iter *fts5MultiIterAlloc(
+  Fts5Index *p,                   /* FTS5 backend to iterate within */
+  int nSeg
+){
+  Fts5Iter *pNew;
+  int nSlot;                      /* Power of two >= nSeg */
+
+  for(nSlot=2; nSlot<nSeg; nSlot=nSlot*2);
+  pNew = fts5IdxMalloc(p, 
+      sizeof(Fts5Iter) +                  /* pNew */
+      sizeof(Fts5SegIter) * (nSlot-1) +   /* pNew->aSeg[] */
+      sizeof(Fts5CResult) * nSlot         /* pNew->aFirst[] */
+  );
+  if( pNew ){
+    pNew->nSeg = nSlot;
+    pNew->aFirst = (Fts5CResult*)&pNew->aSeg[nSlot];
+    pNew->pIndex = p;
+    pNew->xSetOutputs = fts5IterSetOutputs_Noop;
+  }
+  return pNew;
+}
+
+static void fts5PoslistCallback(
+  Fts5Index *pUnused, 
+  void *pContext, 
+  const u8 *pChunk, int nChunk
+){
+  UNUSED_PARAM(pUnused);
+  assert_nc( nChunk>=0 );
+  if( nChunk>0 ){
+    fts5BufferSafeAppendBlob((Fts5Buffer*)pContext, pChunk, nChunk);
+  }
+}
+
+typedef struct PoslistCallbackCtx PoslistCallbackCtx;
+struct PoslistCallbackCtx {
+  Fts5Buffer *pBuf;               /* Append to this buffer */
+  Fts5Colset *pColset;            /* Restrict matches to this column */
+  int eState;                     /* See above */
+};
+
+typedef struct PoslistOffsetsCtx PoslistOffsetsCtx;
+struct PoslistOffsetsCtx {
+  Fts5Buffer *pBuf;               /* Append to this buffer */
+  Fts5Colset *pColset;            /* Restrict matches to this column */
+  int iRead;
+  int iWrite;
+};
+
+/*
+** TODO: Make this more efficient!
+*/
+static int fts5IndexColsetTest(Fts5Colset *pColset, int iCol){
+  int i;
+  for(i=0; i<pColset->nCol; i++){
+    if( pColset->aiCol[i]==iCol ) return 1;
+  }
+  return 0;
+}
+
+static void fts5PoslistOffsetsCallback(
+  Fts5Index *pUnused, 
+  void *pContext, 
+  const u8 *pChunk, int nChunk
+){
+  PoslistOffsetsCtx *pCtx = (PoslistOffsetsCtx*)pContext;
+  UNUSED_PARAM(pUnused);
+  assert_nc( nChunk>=0 );
+  if( nChunk>0 ){
+    int i = 0;
+    while( i<nChunk ){
+      int iVal;
+      i += fts5GetVarint32(&pChunk[i], iVal);
+      iVal += pCtx->iRead - 2;
+      pCtx->iRead = iVal;
+      if( fts5IndexColsetTest(pCtx->pColset, iVal) ){
+        fts5BufferSafeAppendVarint(pCtx->pBuf, iVal + 2 - pCtx->iWrite);
+        pCtx->iWrite = iVal;
+      }
+    }
+  }
+}
+
+static void fts5PoslistFilterCallback(
+  Fts5Index *pUnused,
+  void *pContext, 
+  const u8 *pChunk, int nChunk
+){
+  PoslistCallbackCtx *pCtx = (PoslistCallbackCtx*)pContext;
+  UNUSED_PARAM(pUnused);
+  assert_nc( nChunk>=0 );
+  if( nChunk>0 ){
+    /* Search through to find the first varint with value 1. This is the
+    ** start of the next columns hits. */
+    int i = 0;
+    int iStart = 0;
+
+    if( pCtx->eState==2 ){
+      int iCol;
+      fts5FastGetVarint32(pChunk, i, iCol);
+      if( fts5IndexColsetTest(pCtx->pColset, iCol) ){
+        pCtx->eState = 1;
+        fts5BufferSafeAppendVarint(pCtx->pBuf, 1);
+      }else{
+        pCtx->eState = 0;
+      }
+    }
+
+    do {
+      while( i<nChunk && pChunk[i]!=0x01 ){
+        while( pChunk[i] & 0x80 ) i++;
+        i++;
+      }
+      if( pCtx->eState ){
+        fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);
+      }
+      if( i<nChunk ){
+        int iCol;
+        iStart = i;
+        i++;
+        if( i>=nChunk ){
+          pCtx->eState = 2;
+        }else{
+          fts5FastGetVarint32(pChunk, i, iCol);
+          pCtx->eState = fts5IndexColsetTest(pCtx->pColset, iCol);
+          if( pCtx->eState ){
+            fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);
+            iStart = i;
+          }
+        }
+      }
+    }while( i<nChunk );
+  }
+}
+
+static void fts5ChunkIterate(
+  Fts5Index *p,                   /* Index object */
+  Fts5SegIter *pSeg,              /* Poslist of this iterator */
+  void *pCtx,                     /* Context pointer for xChunk callback */
+  void (*xChunk)(Fts5Index*, void*, const u8*, int)
+){
+  int nRem = pSeg->nPos;          /* Number of bytes still to come */
+  Fts5Data *pData = 0;
+  u8 *pChunk = &pSeg->pLeaf->p[pSeg->iLeafOffset];
+  int nChunk = MIN(nRem, pSeg->pLeaf->szLeaf - pSeg->iLeafOffset);
+  int pgno = pSeg->iLeafPgno;
+  int pgnoSave = 0;
+
+  /* This function does notmwork with detail=none databases. */
+  assert( p->pConfig->eDetail!=FTS5_DETAIL_NONE );
+
+  if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){
+    pgnoSave = pgno+1;
+  }
+
+  while( 1 ){
+    xChunk(p, pCtx, pChunk, nChunk);
+    nRem -= nChunk;
+    fts5DataRelease(pData);
+    if( nRem<=0 ){
+      break;
+    }else{
+      pgno++;
+      pData = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, pgno));
+      if( pData==0 ) break;
+      pChunk = &pData->p[4];
+      nChunk = MIN(nRem, pData->szLeaf - 4);
+      if( pgno==pgnoSave ){
+        assert( pSeg->pNextLeaf==0 );
+        pSeg->pNextLeaf = pData;
+        pData = 0;
+      }
+    }
+  }
+}
+
+/*
+** Iterator pIter currently points to a valid entry (not EOF). This
+** function appends the position list data for the current entry to
+** buffer pBuf. It does not make a copy of the position-list size
+** field.
+*/
+static void fts5SegiterPoslist(
+  Fts5Index *p,
+  Fts5SegIter *pSeg,
+  Fts5Colset *pColset,
+  Fts5Buffer *pBuf
+){
+  if( 0==fts5BufferGrow(&p->rc, pBuf, pSeg->nPos) ){
+    if( pColset==0 ){
+      fts5ChunkIterate(p, pSeg, (void*)pBuf, fts5PoslistCallback);
+    }else{
+      if( p->pConfig->eDetail==FTS5_DETAIL_FULL ){
+        PoslistCallbackCtx sCtx;
+        sCtx.pBuf = pBuf;
+        sCtx.pColset = pColset;
+        sCtx.eState = fts5IndexColsetTest(pColset, 0);
+        assert( sCtx.eState==0 || sCtx.eState==1 );
+        fts5ChunkIterate(p, pSeg, (void*)&sCtx, fts5PoslistFilterCallback);
+      }else{
+        PoslistOffsetsCtx sCtx;
+        memset(&sCtx, 0, sizeof(sCtx));
+        sCtx.pBuf = pBuf;
+        sCtx.pColset = pColset;
+        fts5ChunkIterate(p, pSeg, (void*)&sCtx, fts5PoslistOffsetsCallback);
+      }
+    }
+  }
+}
+
+/*
+** IN/OUT parameter (*pa) points to a position list n bytes in size. If
+** the position list contains entries for column iCol, then (*pa) is set
+** to point to the sub-position-list for that column and the number of
+** bytes in it returned. Or, if the argument position list does not
+** contain any entries for column iCol, return 0.
+*/
+static int fts5IndexExtractCol(
+  const u8 **pa,                  /* IN/OUT: Pointer to poslist */
+  int n,                          /* IN: Size of poslist in bytes */
+  int iCol                        /* Column to extract from poslist */
+){
+  int iCurrent = 0;               /* Anything before the first 0x01 is col 0 */
+  const u8 *p = *pa;
+  const u8 *pEnd = &p[n];         /* One byte past end of position list */
+
+  while( iCol>iCurrent ){
+    /* Advance pointer p until it points to pEnd or an 0x01 byte that is
+    ** not part of a varint. Note that it is not possible for a negative
+    ** or extremely large varint to occur within an uncorrupted position 
+    ** list. So the last byte of each varint may be assumed to have a clear
+    ** 0x80 bit.  */
+    while( *p!=0x01 ){
+      while( *p++ & 0x80 );
+      if( p>=pEnd ) return 0;
+    }
+    *pa = p++;
+    iCurrent = *p++;
+    if( iCurrent & 0x80 ){
+      p--;
+      p += fts5GetVarint32(p, iCurrent);
+    }
+  }
+  if( iCol!=iCurrent ) return 0;
+
+  /* Advance pointer p until it points to pEnd or an 0x01 byte that is
+  ** not part of a varint */
+  while( p<pEnd && *p!=0x01 ){
+    while( *p++ & 0x80 );
+  }
+
+  return p - (*pa);
+}
+
+static int fts5IndexExtractColset (
+  Fts5Colset *pColset,            /* Colset to filter on */
+  const u8 *pPos, int nPos,       /* Position list */
+  Fts5Buffer *pBuf                /* Output buffer */
+){
+  int rc = SQLITE_OK;
+  int i;
+
+  fts5BufferZero(pBuf);
+  for(i=0; i<pColset->nCol; i++){
+    const u8 *pSub = pPos;
+    int nSub = fts5IndexExtractCol(&pSub, nPos, pColset->aiCol[i]);
+    if( nSub ){
+      fts5BufferAppendBlob(&rc, pBuf, nSub, pSub);
+    }
+  }
+  return rc;
+}
+
+/*
+** xSetOutputs callback used by detail=none tables.
+*/
+static void fts5IterSetOutputs_None(Fts5Iter *pIter, Fts5SegIter *pSeg){
+  assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_NONE );
+  pIter->base.iRowid = pSeg->iRowid;
+  pIter->base.nData = pSeg->nPos;
+}
+
+/*
+** xSetOutputs callback used by detail=full and detail=col tables when no
+** column filters are specified.
+*/
+static void fts5IterSetOutputs_Nocolset(Fts5Iter *pIter, Fts5SegIter *pSeg){
+  pIter->base.iRowid = pSeg->iRowid;
+  pIter->base.nData = pSeg->nPos;
+
+  assert( pIter->pIndex->pConfig->eDetail!=FTS5_DETAIL_NONE );
+  assert( pIter->pColset==0 );
+
+  if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf ){
+    /* All data is stored on the current page. Populate the output 
+    ** variables to point into the body of the page object. */
+    pIter->base.pData = &pSeg->pLeaf->p[pSeg->iLeafOffset];
+  }else{
+    /* The data is distributed over two or more pages. Copy it into the
+    ** Fts5Iter.poslist buffer and then set the output pointer to point
+    ** to this buffer.  */
+    fts5BufferZero(&pIter->poslist);
+    fts5SegiterPoslist(pIter->pIndex, pSeg, 0, &pIter->poslist);
+    pIter->base.pData = pIter->poslist.p;
+  }
+}
+
+/*
+** xSetOutputs callback used by detail=col when there is a column filter
+** and there are 100 or more columns. Also called as a fallback from
+** fts5IterSetOutputs_Col100 if the column-list spans more than one page.
+*/
+static void fts5IterSetOutputs_Col(Fts5Iter *pIter, Fts5SegIter *pSeg){
+  fts5BufferZero(&pIter->poslist);
+  fts5SegiterPoslist(pIter->pIndex, pSeg, pIter->pColset, &pIter->poslist);
+  pIter->base.iRowid = pSeg->iRowid;
+  pIter->base.pData = pIter->poslist.p;
+  pIter->base.nData = pIter->poslist.n;
+}
+
+/*
+** xSetOutputs callback used when: 
+**
+**   * detail=col,
+**   * there is a column filter, and
+**   * the table contains 100 or fewer columns. 
+**
+** The last point is to ensure all column numbers are stored as 
+** single-byte varints.
+*/
+static void fts5IterSetOutputs_Col100(Fts5Iter *pIter, Fts5SegIter *pSeg){
+
+  assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_COLUMNS );
+  assert( pIter->pColset );
+
+  if( pSeg->iLeafOffset+pSeg->nPos>pSeg->pLeaf->szLeaf ){
+    fts5IterSetOutputs_Col(pIter, pSeg);
+  }else{
+    u8 *a = (u8*)&pSeg->pLeaf->p[pSeg->iLeafOffset];
+    u8 *pEnd = (u8*)&a[pSeg->nPos]; 
+    int iPrev = 0;
+    int *aiCol = pIter->pColset->aiCol;
+    int *aiColEnd = &aiCol[pIter->pColset->nCol];
+
+    u8 *aOut = pIter->poslist.p;
+    int iPrevOut = 0;
+
+    pIter->base.iRowid = pSeg->iRowid;
+
+    while( a<pEnd ){
+      iPrev += (int)a++[0] - 2;
+      while( *aiCol<iPrev ){
+        aiCol++;
+        if( aiCol==aiColEnd ) goto setoutputs_col_out;
+      }
+      if( *aiCol==iPrev ){
+        *aOut++ = (u8)((iPrev - iPrevOut) + 2);
+        iPrevOut = iPrev;
+      }
+    }
+
+setoutputs_col_out:
+    pIter->base.pData = pIter->poslist.p;
+    pIter->base.nData = aOut - pIter->poslist.p;
+  }
+}
+
+/*
+** xSetOutputs callback used by detail=full when there is a column filter.
+*/
+static void fts5IterSetOutputs_Full(Fts5Iter *pIter, Fts5SegIter *pSeg){
+  Fts5Colset *pColset = pIter->pColset;
+  pIter->base.iRowid = pSeg->iRowid;
+
+  assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_FULL );
+  assert( pColset );
+
+  if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf ){
+    /* All data is stored on the current page. Populate the output 
+    ** variables to point into the body of the page object. */
+    const u8 *a = &pSeg->pLeaf->p[pSeg->iLeafOffset];
+    if( pColset->nCol==1 ){
+      pIter->base.nData = fts5IndexExtractCol(&a, pSeg->nPos,pColset->aiCol[0]);
+      pIter->base.pData = a;
+    }else{
+      fts5BufferZero(&pIter->poslist);
+      fts5IndexExtractColset(pColset, a, pSeg->nPos, &pIter->poslist);
+      pIter->base.pData = pIter->poslist.p;
+      pIter->base.nData = pIter->poslist.n;
+    }
+  }else{
+    /* The data is distributed over two or more pages. Copy it into the
+    ** Fts5Iter.poslist buffer and then set the output pointer to point
+    ** to this buffer.  */
+    fts5BufferZero(&pIter->poslist);
+    fts5SegiterPoslist(pIter->pIndex, pSeg, pColset, &pIter->poslist);
+    pIter->base.pData = pIter->poslist.p;
+    pIter->base.nData = pIter->poslist.n;
+  }
+}
+
+static void fts5IterSetOutputCb(int *pRc, Fts5Iter *pIter){
+  if( *pRc==SQLITE_OK ){
+    Fts5Config *pConfig = pIter->pIndex->pConfig;
+    if( pConfig->eDetail==FTS5_DETAIL_NONE ){
+      pIter->xSetOutputs = fts5IterSetOutputs_None;
+    }
+
+    else if( pIter->pColset==0 ){
+      pIter->xSetOutputs = fts5IterSetOutputs_Nocolset;
+    }
+
+    else if( pConfig->eDetail==FTS5_DETAIL_FULL ){
+      pIter->xSetOutputs = fts5IterSetOutputs_Full;
+    }
+
+    else{
+      assert( pConfig->eDetail==FTS5_DETAIL_COLUMNS );
+      if( pConfig->nCol<=100 ){
+        pIter->xSetOutputs = fts5IterSetOutputs_Col100;
+        sqlite3Fts5BufferSize(pRc, &pIter->poslist, pConfig->nCol);
+      }else{
+        pIter->xSetOutputs = fts5IterSetOutputs_Col;
+      }
+    }
+  }
+}
+
+
+/*
+** Allocate a new Fts5Iter object.
+**
+** The new object will be used to iterate through data in structure pStruct.
+** If iLevel is -ve, then all data in all segments is merged. Or, if iLevel
+** is zero or greater, data from the first nSegment segments on level iLevel
+** is merged.
+**
+** The iterator initially points to the first term/rowid entry in the 
+** iterated data.
+*/
+static void fts5MultiIterNew(
+  Fts5Index *p,                   /* FTS5 backend to iterate within */
+  Fts5Structure *pStruct,         /* Structure of specific index */
+  int flags,                      /* FTS5INDEX_QUERY_XXX flags */
+  Fts5Colset *pColset,            /* Colset to filter on (or NULL) */
+  const u8 *pTerm, int nTerm,     /* Term to seek to (or NULL/0) */
+  int iLevel,                     /* Level to iterate (-1 for all) */
+  int nSegment,                   /* Number of segments to merge (iLevel>=0) */
+  Fts5Iter **ppOut                /* New object */
+){
+  int nSeg = 0;                   /* Number of segment-iters in use */
+  int iIter = 0;                  /* */
+  int iSeg;                       /* Used to iterate through segments */
+  Fts5StructureLevel *pLvl;
+  Fts5Iter *pNew;
+
+  assert( (pTerm==0 && nTerm==0) || iLevel<0 );
+
+  /* Allocate space for the new multi-seg-iterator. */
+  if( p->rc==SQLITE_OK ){
+    if( iLevel<0 ){
+      assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );
+      nSeg = pStruct->nSegment;
+      nSeg += (p->pHash ? 1 : 0);
+    }else{
+      nSeg = MIN(pStruct->aLevel[iLevel].nSeg, nSegment);
+    }
+  }
+  *ppOut = pNew = fts5MultiIterAlloc(p, nSeg);
+  if( pNew==0 ) return;
+  pNew->bRev = (0!=(flags & FTS5INDEX_QUERY_DESC));
+  pNew->bSkipEmpty = (0!=(flags & FTS5INDEX_QUERY_SKIPEMPTY));
+  pNew->pStruct = pStruct;
+  pNew->pColset = pColset;
+  fts5StructureRef(pStruct);
+  if( (flags & FTS5INDEX_QUERY_NOOUTPUT)==0 ){
+    fts5IterSetOutputCb(&p->rc, pNew);
+  }
+
+  /* Initialize each of the component segment iterators. */
+  if( p->rc==SQLITE_OK ){
+    if( iLevel<0 ){
+      Fts5StructureLevel *pEnd = &pStruct->aLevel[pStruct->nLevel];
+      if( p->pHash ){
+        /* Add a segment iterator for the current contents of the hash table. */
+        Fts5SegIter *pIter = &pNew->aSeg[iIter++];
+        fts5SegIterHashInit(p, pTerm, nTerm, flags, pIter);
+      }
+      for(pLvl=&pStruct->aLevel[0]; pLvl<pEnd; pLvl++){
+        for(iSeg=pLvl->nSeg-1; iSeg>=0; iSeg--){
+          Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];
+          Fts5SegIter *pIter = &pNew->aSeg[iIter++];
+          if( pTerm==0 ){
+            fts5SegIterInit(p, pSeg, pIter);
+          }else{
+            fts5SegIterSeekInit(p, pTerm, nTerm, flags, pSeg, pIter);
+          }
+        }
+      }
+    }else{
+      pLvl = &pStruct->aLevel[iLevel];
+      for(iSeg=nSeg-1; iSeg>=0; iSeg--){
+        fts5SegIterInit(p, &pLvl->aSeg[iSeg], &pNew->aSeg[iIter++]);
+      }
+    }
+    assert( iIter==nSeg );
+  }
+
+  /* If the above was successful, each component iterators now points 
+  ** to the first entry in its segment. In this case initialize the 
+  ** aFirst[] array. Or, if an error has occurred, free the iterator
+  ** object and set the output variable to NULL.  */
+  if( p->rc==SQLITE_OK ){
+    for(iIter=pNew->nSeg-1; iIter>0; iIter--){
+      int iEq;
+      if( (iEq = fts5MultiIterDoCompare(pNew, iIter)) ){
+        Fts5SegIter *pSeg = &pNew->aSeg[iEq];
+        if( p->rc==SQLITE_OK ) pSeg->xNext(p, pSeg, 0);
+        fts5MultiIterAdvanced(p, pNew, iEq, iIter);
+      }
+    }
+    fts5MultiIterSetEof(pNew);
+    fts5AssertMultiIterSetup(p, pNew);
+
+    if( pNew->bSkipEmpty && fts5MultiIterIsEmpty(p, pNew) ){
+      fts5MultiIterNext(p, pNew, 0, 0);
+    }else if( pNew->base.bEof==0 ){
+      Fts5SegIter *pSeg = &pNew->aSeg[pNew->aFirst[1].iFirst];
+      pNew->xSetOutputs(pNew, pSeg);
+    }
+
+  }else{
+    fts5MultiIterFree(pNew);
+    *ppOut = 0;
+  }
+}
+
+/*
+** Create an Fts5Iter that iterates through the doclist provided
+** as the second argument.
+*/
+static void fts5MultiIterNew2(
+  Fts5Index *p,                   /* FTS5 backend to iterate within */
+  Fts5Data *pData,                /* Doclist to iterate through */
+  int bDesc,                      /* True for descending rowid order */
+  Fts5Iter **ppOut                /* New object */
+){
+  Fts5Iter *pNew;
+  pNew = fts5MultiIterAlloc(p, 2);
+  if( pNew ){
+    Fts5SegIter *pIter = &pNew->aSeg[1];
+
+    pIter->flags = FTS5_SEGITER_ONETERM;
+    if( pData->szLeaf>0 ){
+      pIter->pLeaf = pData;
+      pIter->iLeafOffset = fts5GetVarint(pData->p, (u64*)&pIter->iRowid);
+      pIter->iEndofDoclist = pData->nn;
+      pNew->aFirst[1].iFirst = 1;
+      if( bDesc ){
+        pNew->bRev = 1;
+        pIter->flags |= FTS5_SEGITER_REVERSE;
+        fts5SegIterReverseInitPage(p, pIter);
+      }else{
+        fts5SegIterLoadNPos(p, pIter);
+      }
+      pData = 0;
+    }else{
+      pNew->base.bEof = 1;
+    }
+    fts5SegIterSetNext(p, pIter);
+
+    *ppOut = pNew;
+  }
+
+  fts5DataRelease(pData);
+}
+
+/*
+** Return true if the iterator is at EOF or if an error has occurred. 
+** False otherwise.
+*/
+static int fts5MultiIterEof(Fts5Index *p, Fts5Iter *pIter){
+  assert( p->rc 
+      || (pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf==0)==pIter->base.bEof 
+  );
+  return (p->rc || pIter->base.bEof);
+}
+
+/*
+** Return the rowid of the entry that the iterator currently points
+** to. If the iterator points to EOF when this function is called the
+** results are undefined.
+*/
+static i64 fts5MultiIterRowid(Fts5Iter *pIter){
+  assert( pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf );
+  return pIter->aSeg[ pIter->aFirst[1].iFirst ].iRowid;
+}
+
+/*
+** Move the iterator to the next entry at or following iMatch.
+*/
+static void fts5MultiIterNextFrom(
+  Fts5Index *p, 
+  Fts5Iter *pIter, 
+  i64 iMatch
+){
+  while( 1 ){
+    i64 iRowid;
+    fts5MultiIterNext(p, pIter, 1, iMatch);
+    if( fts5MultiIterEof(p, pIter) ) break;
+    iRowid = fts5MultiIterRowid(pIter);
+    if( pIter->bRev==0 && iRowid>=iMatch ) break;
+    if( pIter->bRev!=0 && iRowid<=iMatch ) break;
+  }
+}
+
+/*
+** Return a pointer to a buffer containing the term associated with the 
+** entry that the iterator currently points to.
+*/
+static const u8 *fts5MultiIterTerm(Fts5Iter *pIter, int *pn){
+  Fts5SegIter *p = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
+  *pn = p->term.n;
+  return p->term.p;
+}
+
+/*
+** Allocate a new segment-id for the structure pStruct. The new segment
+** id must be between 1 and 65335 inclusive, and must not be used by 
+** any currently existing segment. If a free segment id cannot be found,
+** SQLITE_FULL is returned.
+**
+** If an error has already occurred, this function is a no-op. 0 is 
+** returned in this case.
+*/
+static int fts5AllocateSegid(Fts5Index *p, Fts5Structure *pStruct){
+  int iSegid = 0;
+
+  if( p->rc==SQLITE_OK ){
+    if( pStruct->nSegment>=FTS5_MAX_SEGMENT ){
+      p->rc = SQLITE_FULL;
+    }else{
+      /* FTS5_MAX_SEGMENT is currently defined as 2000. So the following
+      ** array is 63 elements, or 252 bytes, in size.  */
+      u32 aUsed[(FTS5_MAX_SEGMENT+31) / 32];
+      int iLvl, iSeg;
+      int i;
+      u32 mask;
+      memset(aUsed, 0, sizeof(aUsed));
+      for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+        for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){
+          int iId = pStruct->aLevel[iLvl].aSeg[iSeg].iSegid;
+          if( iId<=FTS5_MAX_SEGMENT ){
+            aUsed[(iId-1) / 32] |= 1 << ((iId-1) % 32);
+          }
+        }
+      }
+
+      for(i=0; aUsed[i]==0xFFFFFFFF; i++);
+      mask = aUsed[i];
+      for(iSegid=0; mask & (1 << iSegid); iSegid++);
+      iSegid += 1 + i*32;
+
+#ifdef SQLITE_DEBUG
+      for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+        for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){
+          assert( iSegid!=pStruct->aLevel[iLvl].aSeg[iSeg].iSegid );
+        }
+      }
+      assert( iSegid>0 && iSegid<=FTS5_MAX_SEGMENT );
+
+      {
+        sqlite3_stmt *pIdxSelect = fts5IdxSelectStmt(p);
+        if( p->rc==SQLITE_OK ){
+          u8 aBlob[2] = {0xff, 0xff};
+          sqlite3_bind_int(pIdxSelect, 1, iSegid);
+          sqlite3_bind_blob(pIdxSelect, 2, aBlob, 2, SQLITE_STATIC);
+          assert( sqlite3_step(pIdxSelect)!=SQLITE_ROW );
+          p->rc = sqlite3_reset(pIdxSelect);
+        }
+      }
+#endif
+    }
+  }
+
+  return iSegid;
+}
+
+/*
+** Discard all data currently cached in the hash-tables.
+*/
+static void fts5IndexDiscardData(Fts5Index *p){
+  assert( p->pHash || p->nPendingData==0 );
+  if( p->pHash ){
+    sqlite3Fts5HashClear(p->pHash);
+    p->nPendingData = 0;
+  }
+}
+
+/*
+** Return the size of the prefix, in bytes, that buffer 
+** (pNew/<length-unknown>) shares with buffer (pOld/nOld).
+**
+** Buffer (pNew/<length-unknown>) is guaranteed to be greater 
+** than buffer (pOld/nOld).
+*/
+static int fts5PrefixCompress(int nOld, const u8 *pOld, const u8 *pNew){
+  int i;
+  for(i=0; i<nOld; i++){
+    if( pOld[i]!=pNew[i] ) break;
+  }
+  return i;
+}
+
+static void fts5WriteDlidxClear(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter,
+  int bFlush                      /* If true, write dlidx to disk */
+){
+  int i;
+  assert( bFlush==0 || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n>0) );
+  for(i=0; i<pWriter->nDlidx; i++){
+    Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[i];
+    if( pDlidx->buf.n==0 ) break;
+    if( bFlush ){
+      assert( pDlidx->pgno!=0 );
+      fts5DataWrite(p, 
+          FTS5_DLIDX_ROWID(pWriter->iSegid, i, pDlidx->pgno),
+          pDlidx->buf.p, pDlidx->buf.n
+      );
+    }
+    sqlite3Fts5BufferZero(&pDlidx->buf);
+    pDlidx->bPrevValid = 0;
+  }
+}
+
+/*
+** Grow the pWriter->aDlidx[] array to at least nLvl elements in size.
+** Any new array elements are zeroed before returning.
+*/
+static int fts5WriteDlidxGrow(
+  Fts5Index *p,
+  Fts5SegWriter *pWriter,
+  int nLvl
+){
+  if( p->rc==SQLITE_OK && nLvl>=pWriter->nDlidx ){
+    Fts5DlidxWriter *aDlidx = (Fts5DlidxWriter*)sqlite3_realloc(
+        pWriter->aDlidx, sizeof(Fts5DlidxWriter) * nLvl
+    );
+    if( aDlidx==0 ){
+      p->rc = SQLITE_NOMEM;
+    }else{
+      int nByte = sizeof(Fts5DlidxWriter) * (nLvl - pWriter->nDlidx);
+      memset(&aDlidx[pWriter->nDlidx], 0, nByte);
+      pWriter->aDlidx = aDlidx;
+      pWriter->nDlidx = nLvl;
+    }
+  }
+  return p->rc;
+}
+
+/*
+** If the current doclist-index accumulating in pWriter->aDlidx[] is large
+** enough, flush it to disk and return 1. Otherwise discard it and return
+** zero.
+*/
+static int fts5WriteFlushDlidx(Fts5Index *p, Fts5SegWriter *pWriter){
+  int bFlag = 0;
+
+  /* If there were FTS5_MIN_DLIDX_SIZE or more empty leaf pages written
+  ** to the database, also write the doclist-index to disk.  */
+  if( pWriter->aDlidx[0].buf.n>0 && pWriter->nEmpty>=FTS5_MIN_DLIDX_SIZE ){
+    bFlag = 1;
+  }
+  fts5WriteDlidxClear(p, pWriter, bFlag);
+  pWriter->nEmpty = 0;
+  return bFlag;
+}
+
+/*
+** This function is called whenever processing of the doclist for the 
+** last term on leaf page (pWriter->iBtPage) is completed. 
+**
+** The doclist-index for that term is currently stored in-memory within the
+** Fts5SegWriter.aDlidx[] array. If it is large enough, this function
+** writes it out to disk. Or, if it is too small to bother with, discards
+** it.
+**
+** Fts5SegWriter.btterm currently contains the first term on page iBtPage.
+*/
+static void fts5WriteFlushBtree(Fts5Index *p, Fts5SegWriter *pWriter){
+  int bFlag;
+
+  assert( pWriter->iBtPage || pWriter->nEmpty==0 );
+  if( pWriter->iBtPage==0 ) return;
+  bFlag = fts5WriteFlushDlidx(p, pWriter);
+
+  if( p->rc==SQLITE_OK ){
+    const char *z = (pWriter->btterm.n>0?(const char*)pWriter->btterm.p:"");
+    /* The following was already done in fts5WriteInit(): */
+    /* sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid); */
+    sqlite3_bind_blob(p->pIdxWriter, 2, z, pWriter->btterm.n, SQLITE_STATIC);
+    sqlite3_bind_int64(p->pIdxWriter, 3, bFlag + ((i64)pWriter->iBtPage<<1));
+    sqlite3_step(p->pIdxWriter);
+    p->rc = sqlite3_reset(p->pIdxWriter);
+  }
+  pWriter->iBtPage = 0;
+}
+
+/*
+** This is called once for each leaf page except the first that contains
+** at least one term. Argument (nTerm/pTerm) is the split-key - a term that
+** is larger than all terms written to earlier leaves, and equal to or
+** smaller than the first term on the new leaf.
+**
+** If an error occurs, an error code is left in Fts5Index.rc. If an error
+** has already occurred when this function is called, it is a no-op.
+*/
+static void fts5WriteBtreeTerm(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegWriter *pWriter,         /* Writer object */
+  int nTerm, const u8 *pTerm      /* First term on new page */
+){
+  fts5WriteFlushBtree(p, pWriter);
+  fts5BufferSet(&p->rc, &pWriter->btterm, nTerm, pTerm);
+  pWriter->iBtPage = pWriter->writer.pgno;
+}
+
+/*
+** This function is called when flushing a leaf page that contains no
+** terms at all to disk.
+*/
+static void fts5WriteBtreeNoTerm(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5SegWriter *pWriter          /* Writer object */
+){
+  /* If there were no rowids on the leaf page either and the doclist-index
+  ** has already been started, append an 0x00 byte to it.  */
+  if( pWriter->bFirstRowidInPage && pWriter->aDlidx[0].buf.n>0 ){
+    Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[0];
+    assert( pDlidx->bPrevValid );
+    sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, 0);
+  }
+
+  /* Increment the "number of sequential leaves without a term" counter. */
+  pWriter->nEmpty++;
+}
+
+static i64 fts5DlidxExtractFirstRowid(Fts5Buffer *pBuf){
+  i64 iRowid;
+  int iOff;
+
+  iOff = 1 + fts5GetVarint(&pBuf->p[1], (u64*)&iRowid);
+  fts5GetVarint(&pBuf->p[iOff], (u64*)&iRowid);
+  return iRowid;
+}
+
+/*
+** Rowid iRowid has just been appended to the current leaf page. It is the
+** first on the page. This function appends an appropriate entry to the current
+** doclist-index.
+*/
+static void fts5WriteDlidxAppend(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter, 
+  i64 iRowid
+){
+  int i;
+  int bDone = 0;
+
+  for(i=0; p->rc==SQLITE_OK && bDone==0; i++){
+    i64 iVal;
+    Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[i];
+
+    if( pDlidx->buf.n>=p->pConfig->pgsz ){
+      /* The current doclist-index page is full. Write it to disk and push
+      ** a copy of iRowid (which will become the first rowid on the next
+      ** doclist-index leaf page) up into the next level of the b-tree 
+      ** hierarchy. If the node being flushed is currently the root node,
+      ** also push its first rowid upwards. */
+      pDlidx->buf.p[0] = 0x01;    /* Not the root node */
+      fts5DataWrite(p, 
+          FTS5_DLIDX_ROWID(pWriter->iSegid, i, pDlidx->pgno),
+          pDlidx->buf.p, pDlidx->buf.n
+      );
+      fts5WriteDlidxGrow(p, pWriter, i+2);
+      pDlidx = &pWriter->aDlidx[i];
+      if( p->rc==SQLITE_OK && pDlidx[1].buf.n==0 ){
+        i64 iFirst = fts5DlidxExtractFirstRowid(&pDlidx->buf);
+
+        /* This was the root node. Push its first rowid up to the new root. */
+        pDlidx[1].pgno = pDlidx->pgno;
+        sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, 0);
+        sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, pDlidx->pgno);
+        sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, iFirst);
+        pDlidx[1].bPrevValid = 1;
+        pDlidx[1].iPrev = iFirst;
+      }
+
+      sqlite3Fts5BufferZero(&pDlidx->buf);
+      pDlidx->bPrevValid = 0;
+      pDlidx->pgno++;
+    }else{
+      bDone = 1;
+    }
+
+    if( pDlidx->bPrevValid ){
+      iVal = iRowid - pDlidx->iPrev;
+    }else{
+      i64 iPgno = (i==0 ? pWriter->writer.pgno : pDlidx[-1].pgno);
+      assert( pDlidx->buf.n==0 );
+      sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, !bDone);
+      sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, iPgno);
+      iVal = iRowid;
+    }
+
+    sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, iVal);
+    pDlidx->bPrevValid = 1;
+    pDlidx->iPrev = iRowid;
+  }
+}
+
+static void fts5WriteFlushLeaf(Fts5Index *p, Fts5SegWriter *pWriter){
+  static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };
+  Fts5PageWriter *pPage = &pWriter->writer;
+  i64 iRowid;
+
+static int nCall = 0;
+nCall++;
+
+  assert( (pPage->pgidx.n==0)==(pWriter->bFirstTermInPage) );
+
+  /* Set the szLeaf header field. */
+  assert( 0==fts5GetU16(&pPage->buf.p[2]) );
+  fts5PutU16(&pPage->buf.p[2], (u16)pPage->buf.n);
+
+  if( pWriter->bFirstTermInPage ){
+    /* No term was written to this page. */
+    assert( pPage->pgidx.n==0 );
+    fts5WriteBtreeNoTerm(p, pWriter);
+  }else{
+    /* Append the pgidx to the page buffer. Set the szLeaf header field. */
+    fts5BufferAppendBlob(&p->rc, &pPage->buf, pPage->pgidx.n, pPage->pgidx.p);
+  }
+
+  /* Write the page out to disk */
+  iRowid = FTS5_SEGMENT_ROWID(pWriter->iSegid, pPage->pgno);
+  fts5DataWrite(p, iRowid, pPage->buf.p, pPage->buf.n);
+
+  /* Initialize the next page. */
+  fts5BufferZero(&pPage->buf);
+  fts5BufferZero(&pPage->pgidx);
+  fts5BufferAppendBlob(&p->rc, &pPage->buf, 4, zero);
+  pPage->iPrevPgidx = 0;
+  pPage->pgno++;
+
+  /* Increase the leaves written counter */
+  pWriter->nLeafWritten++;
+
+  /* The new leaf holds no terms or rowids */
+  pWriter->bFirstTermInPage = 1;
+  pWriter->bFirstRowidInPage = 1;
+}
+
+/*
+** Append term pTerm/nTerm to the segment being written by the writer passed
+** as the second argument.
+**
+** If an error occurs, set the Fts5Index.rc error code. If an error has 
+** already occurred, this function is a no-op.
+*/
+static void fts5WriteAppendTerm(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter,
+  int nTerm, const u8 *pTerm 
+){
+  int nPrefix;                    /* Bytes of prefix compression for term */
+  Fts5PageWriter *pPage = &pWriter->writer;
+  Fts5Buffer *pPgidx = &pWriter->writer.pgidx;
+
+  assert( p->rc==SQLITE_OK );
+  assert( pPage->buf.n>=4 );
+  assert( pPage->buf.n>4 || pWriter->bFirstTermInPage );
+
+  /* If the current leaf page is full, flush it to disk. */
+  if( (pPage->buf.n + pPgidx->n + nTerm + 2)>=p->pConfig->pgsz ){
+    if( pPage->buf.n>4 ){
+      fts5WriteFlushLeaf(p, pWriter);
+    }
+    fts5BufferGrow(&p->rc, &pPage->buf, nTerm+FTS5_DATA_PADDING);
+  }
+  
+  /* TODO1: Updating pgidx here. */
+  pPgidx->n += sqlite3Fts5PutVarint(
+      &pPgidx->p[pPgidx->n], pPage->buf.n - pPage->iPrevPgidx
+  );
+  pPage->iPrevPgidx = pPage->buf.n;
+#if 0
+  fts5PutU16(&pPgidx->p[pPgidx->n], pPage->buf.n);
+  pPgidx->n += 2;
+#endif
+
+  if( pWriter->bFirstTermInPage ){
+    nPrefix = 0;
+    if( pPage->pgno!=1 ){
+      /* This is the first term on a leaf that is not the leftmost leaf in
+      ** the segment b-tree. In this case it is necessary to add a term to
+      ** the b-tree hierarchy that is (a) larger than the largest term 
+      ** already written to the segment and (b) smaller than or equal to
+      ** this term. In other words, a prefix of (pTerm/nTerm) that is one
+      ** byte longer than the longest prefix (pTerm/nTerm) shares with the
+      ** previous term. 
+      **
+      ** Usually, the previous term is available in pPage->term. The exception
+      ** is if this is the first term written in an incremental-merge step.
+      ** In this case the previous term is not available, so just write a
+      ** copy of (pTerm/nTerm) into the parent node. This is slightly
+      ** inefficient, but still correct.  */
+      int n = nTerm;
+      if( pPage->term.n ){
+        n = 1 + fts5PrefixCompress(pPage->term.n, pPage->term.p, pTerm);
+      }
+      fts5WriteBtreeTerm(p, pWriter, n, pTerm);
+      pPage = &pWriter->writer;
+    }
+  }else{
+    nPrefix = fts5PrefixCompress(pPage->term.n, pPage->term.p, pTerm);
+    fts5BufferAppendVarint(&p->rc, &pPage->buf, nPrefix);
+  }
+
+  /* Append the number of bytes of new data, then the term data itself
+  ** to the page. */
+  fts5BufferAppendVarint(&p->rc, &pPage->buf, nTerm - nPrefix);
+  fts5BufferAppendBlob(&p->rc, &pPage->buf, nTerm - nPrefix, &pTerm[nPrefix]);
+
+  /* Update the Fts5PageWriter.term field. */
+  fts5BufferSet(&p->rc, &pPage->term, nTerm, pTerm);
+  pWriter->bFirstTermInPage = 0;
+
+  pWriter->bFirstRowidInPage = 0;
+  pWriter->bFirstRowidInDoclist = 1;
+
+  assert( p->rc || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n==0) );
+  pWriter->aDlidx[0].pgno = pPage->pgno;
+}
+
+/*
+** Append a rowid and position-list size field to the writers output. 
+*/
+static void fts5WriteAppendRowid(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter,
+  i64 iRowid
+){
+  if( p->rc==SQLITE_OK ){
+    Fts5PageWriter *pPage = &pWriter->writer;
+
+    if( (pPage->buf.n + pPage->pgidx.n)>=p->pConfig->pgsz ){
+      fts5WriteFlushLeaf(p, pWriter);
+    }
+
+    /* If this is to be the first rowid written to the page, set the 
+    ** rowid-pointer in the page-header. Also append a value to the dlidx
+    ** buffer, in case a doclist-index is required.  */
+    if( pWriter->bFirstRowidInPage ){
+      fts5PutU16(pPage->buf.p, (u16)pPage->buf.n);
+      fts5WriteDlidxAppend(p, pWriter, iRowid);
+    }
+
+    /* Write the rowid. */
+    if( pWriter->bFirstRowidInDoclist || pWriter->bFirstRowidInPage ){
+      fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid);
+    }else{
+      assert( p->rc || iRowid>pWriter->iPrevRowid );
+      fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid - pWriter->iPrevRowid);
+    }
+    pWriter->iPrevRowid = iRowid;
+    pWriter->bFirstRowidInDoclist = 0;
+    pWriter->bFirstRowidInPage = 0;
+  }
+}
+
+static void fts5WriteAppendPoslistData(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter, 
+  const u8 *aData, 
+  int nData
+){
+  Fts5PageWriter *pPage = &pWriter->writer;
+  const u8 *a = aData;
+  int n = nData;
+  
+  assert( p->pConfig->pgsz>0 );
+  while( p->rc==SQLITE_OK 
+     && (pPage->buf.n + pPage->pgidx.n + n)>=p->pConfig->pgsz 
+  ){
+    int nReq = p->pConfig->pgsz - pPage->buf.n - pPage->pgidx.n;
+    int nCopy = 0;
+    while( nCopy<nReq ){
+      i64 dummy;
+      nCopy += fts5GetVarint(&a[nCopy], (u64*)&dummy);
+    }
+    fts5BufferAppendBlob(&p->rc, &pPage->buf, nCopy, a);
+    a += nCopy;
+    n -= nCopy;
+    fts5WriteFlushLeaf(p, pWriter);
+  }
+  if( n>0 ){
+    fts5BufferAppendBlob(&p->rc, &pPage->buf, n, a);
+  }
+}
+
+/*
+** Flush any data cached by the writer object to the database. Free any
+** allocations associated with the writer.
+*/
+static void fts5WriteFinish(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter,         /* Writer object */
+  int *pnLeaf                     /* OUT: Number of leaf pages in b-tree */
+){
+  int i;
+  Fts5PageWriter *pLeaf = &pWriter->writer;
+  if( p->rc==SQLITE_OK ){
+    assert( pLeaf->pgno>=1 );
+    if( pLeaf->buf.n>4 ){
+      fts5WriteFlushLeaf(p, pWriter);
+    }
+    *pnLeaf = pLeaf->pgno-1;
+    if( pLeaf->pgno>1 ){
+      fts5WriteFlushBtree(p, pWriter);
+    }
+  }
+  fts5BufferFree(&pLeaf->term);
+  fts5BufferFree(&pLeaf->buf);
+  fts5BufferFree(&pLeaf->pgidx);
+  fts5BufferFree(&pWriter->btterm);
+
+  for(i=0; i<pWriter->nDlidx; i++){
+    sqlite3Fts5BufferFree(&pWriter->aDlidx[i].buf);
+  }
+  sqlite3_free(pWriter->aDlidx);
+}
+
+static void fts5WriteInit(
+  Fts5Index *p, 
+  Fts5SegWriter *pWriter, 
+  int iSegid
+){
+  const int nBuffer = p->pConfig->pgsz + FTS5_DATA_PADDING;
+
+  memset(pWriter, 0, sizeof(Fts5SegWriter));
+  pWriter->iSegid = iSegid;
+
+  fts5WriteDlidxGrow(p, pWriter, 1);
+  pWriter->writer.pgno = 1;
+  pWriter->bFirstTermInPage = 1;
+  pWriter->iBtPage = 1;
+
+  assert( pWriter->writer.buf.n==0 );
+  assert( pWriter->writer.pgidx.n==0 );
+
+  /* Grow the two buffers to pgsz + padding bytes in size. */
+  sqlite3Fts5BufferSize(&p->rc, &pWriter->writer.pgidx, nBuffer);
+  sqlite3Fts5BufferSize(&p->rc, &pWriter->writer.buf, nBuffer);
+
+  if( p->pIdxWriter==0 ){
+    Fts5Config *pConfig = p->pConfig;
+    fts5IndexPrepareStmt(p, &p->pIdxWriter, sqlite3_mprintf(
+          "INSERT INTO '%q'.'%q_idx'(segid,term,pgno) VALUES(?,?,?)", 
+          pConfig->zDb, pConfig->zName
+    ));
+  }
+
+  if( p->rc==SQLITE_OK ){
+    /* Initialize the 4-byte leaf-page header to 0x00. */
+    memset(pWriter->writer.buf.p, 0, 4);
+    pWriter->writer.buf.n = 4;
+
+    /* Bind the current output segment id to the index-writer. This is an
+    ** optimization over binding the same value over and over as rows are
+    ** inserted into %_idx by the current writer.  */
+    sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid);
+  }
+}
+
+/*
+** Iterator pIter was used to iterate through the input segments of on an
+** incremental merge operation. This function is called if the incremental
+** merge step has finished but the input has not been completely exhausted.
+*/
+static void fts5TrimSegments(Fts5Index *p, Fts5Iter *pIter){
+  int i;
+  Fts5Buffer buf;
+  memset(&buf, 0, sizeof(Fts5Buffer));
+  for(i=0; i<pIter->nSeg; i++){
+    Fts5SegIter *pSeg = &pIter->aSeg[i];
+    if( pSeg->pSeg==0 ){
+      /* no-op */
+    }else if( pSeg->pLeaf==0 ){
+      /* All keys from this input segment have been transfered to the output.
+      ** Set both the first and last page-numbers to 0 to indicate that the
+      ** segment is now empty. */
+      pSeg->pSeg->pgnoLast = 0;
+      pSeg->pSeg->pgnoFirst = 0;
+    }else{
+      int iOff = pSeg->iTermLeafOffset;     /* Offset on new first leaf page */
+      i64 iLeafRowid;
+      Fts5Data *pData;
+      int iId = pSeg->pSeg->iSegid;
+      u8 aHdr[4] = {0x00, 0x00, 0x00, 0x00};
+
+      iLeafRowid = FTS5_SEGMENT_ROWID(iId, pSeg->iTermLeafPgno);
+      pData = fts5DataRead(p, iLeafRowid);
+      if( pData ){
+        fts5BufferZero(&buf);
+        fts5BufferGrow(&p->rc, &buf, pData->nn);
+        fts5BufferAppendBlob(&p->rc, &buf, sizeof(aHdr), aHdr);
+        fts5BufferAppendVarint(&p->rc, &buf, pSeg->term.n);
+        fts5BufferAppendBlob(&p->rc, &buf, pSeg->term.n, pSeg->term.p);
+        fts5BufferAppendBlob(&p->rc, &buf, pData->szLeaf-iOff, &pData->p[iOff]);
+        if( p->rc==SQLITE_OK ){
+          /* Set the szLeaf field */
+          fts5PutU16(&buf.p[2], (u16)buf.n);
+        }
+
+        /* Set up the new page-index array */
+        fts5BufferAppendVarint(&p->rc, &buf, 4);
+        if( pSeg->iLeafPgno==pSeg->iTermLeafPgno 
+         && pSeg->iEndofDoclist<pData->szLeaf 
+        ){
+          int nDiff = pData->szLeaf - pSeg->iEndofDoclist;
+          fts5BufferAppendVarint(&p->rc, &buf, buf.n - 1 - nDiff - 4);
+          fts5BufferAppendBlob(&p->rc, &buf, 
+              pData->nn - pSeg->iPgidxOff, &pData->p[pSeg->iPgidxOff]
+          );
+        }
+
+        fts5DataRelease(pData);
+        pSeg->pSeg->pgnoFirst = pSeg->iTermLeafPgno;
+        fts5DataDelete(p, FTS5_SEGMENT_ROWID(iId, 1), iLeafRowid);
+        fts5DataWrite(p, iLeafRowid, buf.p, buf.n);
+      }
+    }
+  }
+  fts5BufferFree(&buf);
+}
+
+static void fts5MergeChunkCallback(
+  Fts5Index *p, 
+  void *pCtx, 
+  const u8 *pChunk, int nChunk
+){
+  Fts5SegWriter *pWriter = (Fts5SegWriter*)pCtx;
+  fts5WriteAppendPoslistData(p, pWriter, pChunk, nChunk);
+}
+
+/*
+**
+*/
+static void fts5IndexMergeLevel(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Structure **ppStruct,       /* IN/OUT: Stucture of index */
+  int iLvl,                       /* Level to read input from */
+  int *pnRem                      /* Write up to this many output leaves */
+){
+  Fts5Structure *pStruct = *ppStruct;
+  Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
+  Fts5StructureLevel *pLvlOut;
+  Fts5Iter *pIter = 0;       /* Iterator to read input data */
+  int nRem = pnRem ? *pnRem : 0;  /* Output leaf pages left to write */
+  int nInput;                     /* Number of input segments */
+  Fts5SegWriter writer;           /* Writer object */
+  Fts5StructureSegment *pSeg;     /* Output segment */
+  Fts5Buffer term;
+  int bOldest;                    /* True if the output segment is the oldest */
+  int eDetail = p->pConfig->eDetail;
+  const int flags = FTS5INDEX_QUERY_NOOUTPUT;
+
+  assert( iLvl<pStruct->nLevel );
+  assert( pLvl->nMerge<=pLvl->nSeg );
+
+  memset(&writer, 0, sizeof(Fts5SegWriter));
+  memset(&term, 0, sizeof(Fts5Buffer));
+  if( pLvl->nMerge ){
+    pLvlOut = &pStruct->aLevel[iLvl+1];
+    assert( pLvlOut->nSeg>0 );
+    nInput = pLvl->nMerge;
+    pSeg = &pLvlOut->aSeg[pLvlOut->nSeg-1];
+
+    fts5WriteInit(p, &writer, pSeg->iSegid);
+    writer.writer.pgno = pSeg->pgnoLast+1;
+    writer.iBtPage = 0;
+  }else{
+    int iSegid = fts5AllocateSegid(p, pStruct);
+
+    /* Extend the Fts5Structure object as required to ensure the output
+    ** segment exists. */
+    if( iLvl==pStruct->nLevel-1 ){
+      fts5StructureAddLevel(&p->rc, ppStruct);
+      pStruct = *ppStruct;
+    }
+    fts5StructureExtendLevel(&p->rc, pStruct, iLvl+1, 1, 0);
+    if( p->rc ) return;
+    pLvl = &pStruct->aLevel[iLvl];
+    pLvlOut = &pStruct->aLevel[iLvl+1];
+
+    fts5WriteInit(p, &writer, iSegid);
+
+    /* Add the new segment to the output level */
+    pSeg = &pLvlOut->aSeg[pLvlOut->nSeg];
+    pLvlOut->nSeg++;
+    pSeg->pgnoFirst = 1;
+    pSeg->iSegid = iSegid;
+    pStruct->nSegment++;
+
+    /* Read input from all segments in the input level */
+    nInput = pLvl->nSeg;
+  }
+  bOldest = (pLvlOut->nSeg==1 && pStruct->nLevel==iLvl+2);
+
+  assert( iLvl>=0 );
+  for(fts5MultiIterNew(p, pStruct, flags, 0, 0, 0, iLvl, nInput, &pIter);
+      fts5MultiIterEof(p, pIter)==0;
+      fts5MultiIterNext(p, pIter, 0, 0)
+  ){
+    Fts5SegIter *pSegIter = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
+    int nPos;                     /* position-list size field value */
+    int nTerm;
+    const u8 *pTerm;
+
+    /* Check for key annihilation. */
+    if( pSegIter->nPos==0 && (bOldest || pSegIter->bDel==0) ) continue;
+
+    pTerm = fts5MultiIterTerm(pIter, &nTerm);
+    if( nTerm!=term.n || memcmp(pTerm, term.p, nTerm) ){
+      if( pnRem && writer.nLeafWritten>nRem ){
+        break;
+      }
+
+      /* This is a new term. Append a term to the output segment. */
+      fts5WriteAppendTerm(p, &writer, nTerm, pTerm);
+      fts5BufferSet(&p->rc, &term, nTerm, pTerm);
+    }
+
+    /* Append the rowid to the output */
+    /* WRITEPOSLISTSIZE */
+    fts5WriteAppendRowid(p, &writer, fts5MultiIterRowid(pIter));
+
+    if( eDetail==FTS5_DETAIL_NONE ){
+      if( pSegIter->bDel ){
+        fts5BufferAppendVarint(&p->rc, &writer.writer.buf, 0);
+        if( pSegIter->nPos>0 ){
+          fts5BufferAppendVarint(&p->rc, &writer.writer.buf, 0);
+        }
+      }
+    }else{
+      /* Append the position-list data to the output */
+      nPos = pSegIter->nPos*2 + pSegIter->bDel;
+      fts5BufferAppendVarint(&p->rc, &writer.writer.buf, nPos);
+      fts5ChunkIterate(p, pSegIter, (void*)&writer, fts5MergeChunkCallback);
+    }
+  }
+
+  /* Flush the last leaf page to disk. Set the output segment b-tree height
+  ** and last leaf page number at the same time.  */
+  fts5WriteFinish(p, &writer, &pSeg->pgnoLast);
+
+  if( fts5MultiIterEof(p, pIter) ){
+    int i;
+
+    /* Remove the redundant segments from the %_data table */
+    for(i=0; i<nInput; i++){
+      fts5DataRemoveSegment(p, pLvl->aSeg[i].iSegid);
+    }
+
+    /* Remove the redundant segments from the input level */
+    if( pLvl->nSeg!=nInput ){
+      int nMove = (pLvl->nSeg - nInput) * sizeof(Fts5StructureSegment);
+      memmove(pLvl->aSeg, &pLvl->aSeg[nInput], nMove);
+    }
+    pStruct->nSegment -= nInput;
+    pLvl->nSeg -= nInput;
+    pLvl->nMerge = 0;
+    if( pSeg->pgnoLast==0 ){
+      pLvlOut->nSeg--;
+      pStruct->nSegment--;
+    }
+  }else{
+    assert( pSeg->pgnoLast>0 );
+    fts5TrimSegments(p, pIter);
+    pLvl->nMerge = nInput;
+  }
+
+  fts5MultiIterFree(pIter);
+  fts5BufferFree(&term);
+  if( pnRem ) *pnRem -= writer.nLeafWritten;
+}
+
+/*
+** Do up to nPg pages of automerge work on the index.
+**
+** Return true if any changes were actually made, or false otherwise.
+*/
+static int fts5IndexMerge(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
+  int nPg,                        /* Pages of work to do */
+  int nMin                        /* Minimum number of segments to merge */
+){
+  int nRem = nPg;
+  int bRet = 0;
+  Fts5Structure *pStruct = *ppStruct;
+  while( nRem>0 && p->rc==SQLITE_OK ){
+    int iLvl;                   /* To iterate through levels */
+    int iBestLvl = 0;           /* Level offering the most input segments */
+    int nBest = 0;              /* Number of input segments on best level */
+
+    /* Set iBestLvl to the level to read input segments from. */
+    assert( pStruct->nLevel>0 );
+    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+      Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];
+      if( pLvl->nMerge ){
+        if( pLvl->nMerge>nBest ){
+          iBestLvl = iLvl;
+          nBest = pLvl->nMerge;
+        }
+        break;
+      }
+      if( pLvl->nSeg>nBest ){
+        nBest = pLvl->nSeg;
+        iBestLvl = iLvl;
+      }
+    }
+
+    /* If nBest is still 0, then the index must be empty. */
+#ifdef SQLITE_DEBUG
+    for(iLvl=0; nBest==0 && iLvl<pStruct->nLevel; iLvl++){
+      assert( pStruct->aLevel[iLvl].nSeg==0 );
+    }
+#endif
+
+    if( nBest<nMin && pStruct->aLevel[iBestLvl].nMerge==0 ){
+      break;
+    }
+    bRet = 1;
+    fts5IndexMergeLevel(p, &pStruct, iBestLvl, &nRem);
+    if( p->rc==SQLITE_OK && pStruct->aLevel[iBestLvl].nMerge==0 ){
+      fts5StructurePromote(p, iBestLvl+1, pStruct);
+    }
+  }
+  *ppStruct = pStruct;
+  return bRet;
+}
+
+/*
+** A total of nLeaf leaf pages of data has just been flushed to a level-0
+** segment. This function updates the write-counter accordingly and, if
+** necessary, performs incremental merge work.
+**
+** If an error occurs, set the Fts5Index.rc error code. If an error has 
+** already occurred, this function is a no-op.
+*/
+static void fts5IndexAutomerge(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
+  int nLeaf                       /* Number of output leaves just written */
+){
+  if( p->rc==SQLITE_OK && p->pConfig->nAutomerge>0 ){
+    Fts5Structure *pStruct = *ppStruct;
+    u64 nWrite;                   /* Initial value of write-counter */
+    int nWork;                    /* Number of work-quanta to perform */
+    int nRem;                     /* Number of leaf pages left to write */
+
+    /* Update the write-counter. While doing so, set nWork. */
+    nWrite = pStruct->nWriteCounter;
+    nWork = (int)(((nWrite + nLeaf) / p->nWorkUnit) - (nWrite / p->nWorkUnit));
+    pStruct->nWriteCounter += nLeaf;
+    nRem = (int)(p->nWorkUnit * nWork * pStruct->nLevel);
+
+    fts5IndexMerge(p, ppStruct, nRem, p->pConfig->nAutomerge);
+  }
+}
+
+static void fts5IndexCrisismerge(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Structure **ppStruct        /* IN/OUT: Current structure of index */
+){
+  const int nCrisis = p->pConfig->nCrisisMerge;
+  Fts5Structure *pStruct = *ppStruct;
+  int iLvl = 0;
+
+  assert( p->rc!=SQLITE_OK || pStruct->nLevel>0 );
+  while( p->rc==SQLITE_OK && pStruct->aLevel[iLvl].nSeg>=nCrisis ){
+    fts5IndexMergeLevel(p, &pStruct, iLvl, 0);
+    assert( p->rc!=SQLITE_OK || pStruct->nLevel>(iLvl+1) );
+    fts5StructurePromote(p, iLvl+1, pStruct);
+    iLvl++;
+  }
+  *ppStruct = pStruct;
+}
+
+static int fts5IndexReturn(Fts5Index *p){
+  int rc = p->rc;
+  p->rc = SQLITE_OK;
+  return rc;
+}
+
+typedef struct Fts5FlushCtx Fts5FlushCtx;
+struct Fts5FlushCtx {
+  Fts5Index *pIdx;
+  Fts5SegWriter writer; 
+};
+
+/*
+** Buffer aBuf[] contains a list of varints, all small enough to fit
+** in a 32-bit integer. Return the size of the largest prefix of this 
+** list nMax bytes or less in size.
+*/
+static int fts5PoslistPrefix(const u8 *aBuf, int nMax){
+  int ret;
+  u32 dummy;
+  ret = fts5GetVarint32(aBuf, dummy);
+  if( ret<nMax ){
+    while( 1 ){
+      int i = fts5GetVarint32(&aBuf[ret], dummy);
+      if( (ret + i) > nMax ) break;
+      ret += i;
+    }
+  }
+  return ret;
+}
+
+/*
+** Flush the contents of in-memory hash table iHash to a new level-0 
+** segment on disk. Also update the corresponding structure record.
+**
+** If an error occurs, set the Fts5Index.rc error code. If an error has 
+** already occurred, this function is a no-op.
+*/
+static void fts5FlushOneHash(Fts5Index *p){
+  Fts5Hash *pHash = p->pHash;
+  Fts5Structure *pStruct;
+  int iSegid;
+  int pgnoLast = 0;                 /* Last leaf page number in segment */
+
+  /* Obtain a reference to the index structure and allocate a new segment-id
+  ** for the new level-0 segment.  */
+  pStruct = fts5StructureRead(p);
+  iSegid = fts5AllocateSegid(p, pStruct);
+  fts5StructureInvalidate(p);
+
+  if( iSegid ){
+    const int pgsz = p->pConfig->pgsz;
+    int eDetail = p->pConfig->eDetail;
+    Fts5StructureSegment *pSeg;   /* New segment within pStruct */
+    Fts5Buffer *pBuf;             /* Buffer in which to assemble leaf page */
+    Fts5Buffer *pPgidx;           /* Buffer in which to assemble pgidx */
+
+    Fts5SegWriter writer;
+    fts5WriteInit(p, &writer, iSegid);
+
+    pBuf = &writer.writer.buf;
+    pPgidx = &writer.writer.pgidx;
+
+    /* fts5WriteInit() should have initialized the buffers to (most likely)
+    ** the maximum space required. */
+    assert( p->rc || pBuf->nSpace>=(pgsz + FTS5_DATA_PADDING) );
+    assert( p->rc || pPgidx->nSpace>=(pgsz + FTS5_DATA_PADDING) );
+
+    /* Begin scanning through hash table entries. This loop runs once for each
+    ** term/doclist currently stored within the hash table. */
+    if( p->rc==SQLITE_OK ){
+      p->rc = sqlite3Fts5HashScanInit(pHash, 0, 0);
+    }
+    while( p->rc==SQLITE_OK && 0==sqlite3Fts5HashScanEof(pHash) ){
+      const char *zTerm;          /* Buffer containing term */
+      const u8 *pDoclist;         /* Pointer to doclist for this term */
+      int nDoclist;               /* Size of doclist in bytes */
+
+      /* Write the term for this entry to disk. */
+      sqlite3Fts5HashScanEntry(pHash, &zTerm, &pDoclist, &nDoclist);
+      fts5WriteAppendTerm(p, &writer, (int)strlen(zTerm), (const u8*)zTerm);
+
+      assert( writer.bFirstRowidInPage==0 );
+      if( pgsz>=(pBuf->n + pPgidx->n + nDoclist + 1) ){
+        /* The entire doclist will fit on the current leaf. */
+        fts5BufferSafeAppendBlob(pBuf, pDoclist, nDoclist);
+      }else{
+        i64 iRowid = 0;
+        i64 iDelta = 0;
+        int iOff = 0;
+
+        /* The entire doclist will not fit on this leaf. The following 
+        ** loop iterates through the poslists that make up the current 
+        ** doclist.  */
+        while( p->rc==SQLITE_OK && iOff<nDoclist ){
+          iOff += fts5GetVarint(&pDoclist[iOff], (u64*)&iDelta);
+          iRowid += iDelta;
+          
+          if( writer.bFirstRowidInPage ){
+            fts5PutU16(&pBuf->p[0], (u16)pBuf->n);   /* first rowid on page */
+            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iRowid);
+            writer.bFirstRowidInPage = 0;
+            fts5WriteDlidxAppend(p, &writer, iRowid);
+          }else{
+            pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iDelta);
+          }
+          assert( pBuf->n<=pBuf->nSpace );
+
+          if( eDetail==FTS5_DETAIL_NONE ){
+            if( iOff<nDoclist && pDoclist[iOff]==0 ){
+              pBuf->p[pBuf->n++] = 0;
+              iOff++;
+              if( iOff<nDoclist && pDoclist[iOff]==0 ){
+                pBuf->p[pBuf->n++] = 0;
+                iOff++;
+              }
+            }
+            if( (pBuf->n + pPgidx->n)>=pgsz ){
+              fts5WriteFlushLeaf(p, &writer);
+            }
+          }else{
+            int bDummy;
+            int nPos;
+            int nCopy = fts5GetPoslistSize(&pDoclist[iOff], &nPos, &bDummy);
+            nCopy += nPos;
+            if( (pBuf->n + pPgidx->n + nCopy) <= pgsz ){
+              /* The entire poslist will fit on the current leaf. So copy
+              ** it in one go. */
+              fts5BufferSafeAppendBlob(pBuf, &pDoclist[iOff], nCopy);
+            }else{
+              /* The entire poslist will not fit on this leaf. So it needs
+              ** to be broken into sections. The only qualification being
+              ** that each varint must be stored contiguously.  */
+              const u8 *pPoslist = &pDoclist[iOff];
+              int iPos = 0;
+              while( p->rc==SQLITE_OK ){
+                int nSpace = pgsz - pBuf->n - pPgidx->n;
+                int n = 0;
+                if( (nCopy - iPos)<=nSpace ){
+                  n = nCopy - iPos;
+                }else{
+                  n = fts5PoslistPrefix(&pPoslist[iPos], nSpace);
+                }
+                assert( n>0 );
+                fts5BufferSafeAppendBlob(pBuf, &pPoslist[iPos], n);
+                iPos += n;
+                if( (pBuf->n + pPgidx->n)>=pgsz ){
+                  fts5WriteFlushLeaf(p, &writer);
+                }
+                if( iPos>=nCopy ) break;
+              }
+            }
+            iOff += nCopy;
+          }
+        }
+      }
+
+      /* TODO2: Doclist terminator written here. */
+      /* pBuf->p[pBuf->n++] = '\0'; */
+      assert( pBuf->n<=pBuf->nSpace );
+      sqlite3Fts5HashScanNext(pHash);
+    }
+    sqlite3Fts5HashClear(pHash);
+    fts5WriteFinish(p, &writer, &pgnoLast);
+
+    /* Update the Fts5Structure. It is written back to the database by the
+    ** fts5StructureRelease() call below.  */
+    if( pStruct->nLevel==0 ){
+      fts5StructureAddLevel(&p->rc, &pStruct);
+    }
+    fts5StructureExtendLevel(&p->rc, pStruct, 0, 1, 0);
+    if( p->rc==SQLITE_OK ){
+      pSeg = &pStruct->aLevel[0].aSeg[ pStruct->aLevel[0].nSeg++ ];
+      pSeg->iSegid = iSegid;
+      pSeg->pgnoFirst = 1;
+      pSeg->pgnoLast = pgnoLast;
+      pStruct->nSegment++;
+    }
+    fts5StructurePromote(p, 0, pStruct);
+  }
+
+  fts5IndexAutomerge(p, &pStruct, pgnoLast);
+  fts5IndexCrisismerge(p, &pStruct);
+  fts5StructureWrite(p, pStruct);
+  fts5StructureRelease(pStruct);
+}
+
+/*
+** Flush any data stored in the in-memory hash tables to the database.
+*/
+static void fts5IndexFlush(Fts5Index *p){
+  /* Unless it is empty, flush the hash table to disk */
+  if( p->nPendingData ){
+    assert( p->pHash );
+    p->nPendingData = 0;
+    fts5FlushOneHash(p);
+  }
+}
+
+static Fts5Structure *fts5IndexOptimizeStruct(
+  Fts5Index *p, 
+  Fts5Structure *pStruct
+){
+  Fts5Structure *pNew = 0;
+  int nByte = sizeof(Fts5Structure);
+  int nSeg = pStruct->nSegment;
+  int i;
+
+  /* Figure out if this structure requires optimization. A structure does
+  ** not require optimization if either:
+  **
+  **  + it consists of fewer than two segments, or 
+  **  + all segments are on the same level, or
+  **  + all segments except one are currently inputs to a merge operation.
+  **
+  ** In the first case, return NULL. In the second, increment the ref-count
+  ** on *pStruct and return a copy of the pointer to it.
+  */
+  if( nSeg<2 ) return 0;
+  for(i=0; i<pStruct->nLevel; i++){
+    int nThis = pStruct->aLevel[i].nSeg;
+    if( nThis==nSeg || (nThis==nSeg-1 && pStruct->aLevel[i].nMerge==nThis) ){
+      fts5StructureRef(pStruct);
+      return pStruct;
+    }
+    assert( pStruct->aLevel[i].nMerge<=nThis );
+  }
+
+  nByte += (pStruct->nLevel+1) * sizeof(Fts5StructureLevel);
+  pNew = (Fts5Structure*)sqlite3Fts5MallocZero(&p->rc, nByte);
+
+  if( pNew ){
+    Fts5StructureLevel *pLvl;
+    nByte = nSeg * sizeof(Fts5StructureSegment);
+    pNew->nLevel = pStruct->nLevel+1;
+    pNew->nRef = 1;
+    pNew->nWriteCounter = pStruct->nWriteCounter;
+    pLvl = &pNew->aLevel[pStruct->nLevel];
+    pLvl->aSeg = (Fts5StructureSegment*)sqlite3Fts5MallocZero(&p->rc, nByte);
+    if( pLvl->aSeg ){
+      int iLvl, iSeg;
+      int iSegOut = 0;
+      /* Iterate through all segments, from oldest to newest. Add them to
+      ** the new Fts5Level object so that pLvl->aSeg[0] is the oldest
+      ** segment in the data structure.  */
+      for(iLvl=pStruct->nLevel-1; iLvl>=0; iLvl--){
+        for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){
+          pLvl->aSeg[iSegOut] = pStruct->aLevel[iLvl].aSeg[iSeg];
+          iSegOut++;
+        }
+      }
+      pNew->nSegment = pLvl->nSeg = nSeg;
+    }else{
+      sqlite3_free(pNew);
+      pNew = 0;
+    }
+  }
+
+  return pNew;
+}
+
+static int sqlite3Fts5IndexOptimize(Fts5Index *p){
+  Fts5Structure *pStruct;
+  Fts5Structure *pNew = 0;
+
+  assert( p->rc==SQLITE_OK );
+  fts5IndexFlush(p);
+  pStruct = fts5StructureRead(p);
+  fts5StructureInvalidate(p);
+
+  if( pStruct ){
+    pNew = fts5IndexOptimizeStruct(p, pStruct);
+  }
+  fts5StructureRelease(pStruct);
+
+  assert( pNew==0 || pNew->nSegment>0 );
+  if( pNew ){
+    int iLvl;
+    for(iLvl=0; pNew->aLevel[iLvl].nSeg==0; iLvl++){}
+    while( p->rc==SQLITE_OK && pNew->aLevel[iLvl].nSeg>0 ){
+      int nRem = FTS5_OPT_WORK_UNIT;
+      fts5IndexMergeLevel(p, &pNew, iLvl, &nRem);
+    }
+
+    fts5StructureWrite(p, pNew);
+    fts5StructureRelease(pNew);
+  }
+
+  return fts5IndexReturn(p); 
+}
+
+/*
+** This is called to implement the special "VALUES('merge', $nMerge)"
+** INSERT command.
+*/
+static int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge){
+  Fts5Structure *pStruct = fts5StructureRead(p);
+  if( pStruct ){
+    int nMin = p->pConfig->nUsermerge;
+    fts5StructureInvalidate(p);
+    if( nMerge<0 ){
+      Fts5Structure *pNew = fts5IndexOptimizeStruct(p, pStruct);
+      fts5StructureRelease(pStruct);
+      pStruct = pNew;
+      nMin = 2;
+      nMerge = nMerge*-1;
+    }
+    if( pStruct && pStruct->nLevel ){
+      if( fts5IndexMerge(p, &pStruct, nMerge, nMin) ){
+        fts5StructureWrite(p, pStruct);
+      }
+    }
+    fts5StructureRelease(pStruct);
+  }
+  return fts5IndexReturn(p);
+}
+
+static void fts5AppendRowid(
+  Fts5Index *p,
+  i64 iDelta,
+  Fts5Iter *pUnused,
+  Fts5Buffer *pBuf
+){
+  UNUSED_PARAM(pUnused);
+  fts5BufferAppendVarint(&p->rc, pBuf, iDelta);
+}
+
+static void fts5AppendPoslist(
+  Fts5Index *p,
+  i64 iDelta,
+  Fts5Iter *pMulti,
+  Fts5Buffer *pBuf
+){
+  int nData = pMulti->base.nData;
+  assert( nData>0 );
+  if( p->rc==SQLITE_OK && 0==fts5BufferGrow(&p->rc, pBuf, nData+9+9) ){
+    fts5BufferSafeAppendVarint(pBuf, iDelta);
+    fts5BufferSafeAppendVarint(pBuf, nData*2);
+    fts5BufferSafeAppendBlob(pBuf, pMulti->base.pData, nData);
+  }
+}
+
+
+static void fts5DoclistIterNext(Fts5DoclistIter *pIter){
+  u8 *p = pIter->aPoslist + pIter->nSize + pIter->nPoslist;
+
+  assert( pIter->aPoslist );
+  if( p>=pIter->aEof ){
+    pIter->aPoslist = 0;
+  }else{
+    i64 iDelta;
+
+    p += fts5GetVarint(p, (u64*)&iDelta);
+    pIter->iRowid += iDelta;
+
+    /* Read position list size */
+    if( p[0] & 0x80 ){
+      int nPos;
+      pIter->nSize = fts5GetVarint32(p, nPos);
+      pIter->nPoslist = (nPos>>1);
+    }else{
+      pIter->nPoslist = ((int)(p[0])) >> 1;
+      pIter->nSize = 1;
+    }
+
+    pIter->aPoslist = p;
+  }
+}
+
+static void fts5DoclistIterInit(
+  Fts5Buffer *pBuf, 
+  Fts5DoclistIter *pIter
+){
+  memset(pIter, 0, sizeof(*pIter));
+  pIter->aPoslist = pBuf->p;
+  pIter->aEof = &pBuf->p[pBuf->n];
+  fts5DoclistIterNext(pIter);
+}
+
+#if 0
+/*
+** Append a doclist to buffer pBuf.
+**
+** This function assumes that space within the buffer has already been
+** allocated.
+*/
+static void fts5MergeAppendDocid(
+  Fts5Buffer *pBuf,               /* Buffer to write to */
+  i64 *piLastRowid,               /* IN/OUT: Previous rowid written (if any) */
+  i64 iRowid                      /* Rowid to append */
+){
+  assert( pBuf->n!=0 || (*piLastRowid)==0 );
+  fts5BufferSafeAppendVarint(pBuf, iRowid - *piLastRowid);
+  *piLastRowid = iRowid;
+}
+#endif
+
+#define fts5MergeAppendDocid(pBuf, iLastRowid, iRowid) {       \
+  assert( (pBuf)->n!=0 || (iLastRowid)==0 );                   \
+  fts5BufferSafeAppendVarint((pBuf), (iRowid) - (iLastRowid)); \
+  (iLastRowid) = (iRowid);                                     \
+}
+
+/*
+** Swap the contents of buffer *p1 with that of *p2.
+*/
+static void fts5BufferSwap(Fts5Buffer *p1, Fts5Buffer *p2){
+  Fts5Buffer tmp = *p1;
+  *p1 = *p2;
+  *p2 = tmp;
+}
+
+static void fts5NextRowid(Fts5Buffer *pBuf, int *piOff, i64 *piRowid){
+  int i = *piOff;
+  if( i>=pBuf->n ){
+    *piOff = -1;
+  }else{
+    u64 iVal;
+    *piOff = i + sqlite3Fts5GetVarint(&pBuf->p[i], &iVal);
+    *piRowid += iVal;
+  }
+}
+
+/*
+** This is the equivalent of fts5MergePrefixLists() for detail=none mode.
+** In this case the buffers consist of a delta-encoded list of rowids only.
+*/
+static void fts5MergeRowidLists(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Buffer *p1,                 /* First list to merge */
+  Fts5Buffer *p2                  /* Second list to merge */
+){
+  int i1 = 0;
+  int i2 = 0;
+  i64 iRowid1 = 0;
+  i64 iRowid2 = 0;
+  i64 iOut = 0;
+
+  Fts5Buffer out;
+  memset(&out, 0, sizeof(out));
+  sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n);
+  if( p->rc ) return;
+
+  fts5NextRowid(p1, &i1, &iRowid1);
+  fts5NextRowid(p2, &i2, &iRowid2);
+  while( i1>=0 || i2>=0 ){
+    if( i1>=0 && (i2<0 || iRowid1<iRowid2) ){
+      assert( iOut==0 || iRowid1>iOut );
+      fts5BufferSafeAppendVarint(&out, iRowid1 - iOut);
+      iOut = iRowid1;
+      fts5NextRowid(p1, &i1, &iRowid1);
+    }else{
+      assert( iOut==0 || iRowid2>iOut );
+      fts5BufferSafeAppendVarint(&out, iRowid2 - iOut);
+      iOut = iRowid2;
+      if( i1>=0 && iRowid1==iRowid2 ){
+        fts5NextRowid(p1, &i1, &iRowid1);
+      }
+      fts5NextRowid(p2, &i2, &iRowid2);
+    }
+  }
+
+  fts5BufferSwap(&out, p1);
+  fts5BufferFree(&out);
+}
+
+/*
+** Buffers p1 and p2 contain doclists. This function merges the content
+** of the two doclists together and sets buffer p1 to the result before
+** returning.
+**
+** If an error occurs, an error code is left in p->rc. If an error has
+** already occurred, this function is a no-op.
+*/
+static void fts5MergePrefixLists(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5Buffer *p1,                 /* First list to merge */
+  Fts5Buffer *p2                  /* Second list to merge */
+){
+  if( p2->n ){
+    i64 iLastRowid = 0;
+    Fts5DoclistIter i1;
+    Fts5DoclistIter i2;
+    Fts5Buffer out = {0, 0, 0};
+    Fts5Buffer tmp = {0, 0, 0};
+
+    if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n) ) return;
+    fts5DoclistIterInit(p1, &i1);
+    fts5DoclistIterInit(p2, &i2);
+
+    while( 1 ){
+      if( i1.iRowid<i2.iRowid ){
+        /* Copy entry from i1 */
+        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
+        fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);
+        fts5DoclistIterNext(&i1);
+        if( i1.aPoslist==0 ) break;
+      }
+      else if( i2.iRowid!=i1.iRowid ){
+        /* Copy entry from i2 */
+        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
+        fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);
+        fts5DoclistIterNext(&i2);
+        if( i2.aPoslist==0 ) break;
+      }
+      else{
+        /* Merge the two position lists. */ 
+        i64 iPos1 = 0;
+        i64 iPos2 = 0;
+        int iOff1 = 0;
+        int iOff2 = 0;
+        u8 *a1 = &i1.aPoslist[i1.nSize];
+        u8 *a2 = &i2.aPoslist[i2.nSize];
+
+        i64 iPrev = 0;
+        Fts5PoslistWriter writer;
+        memset(&writer, 0, sizeof(writer));
+
+        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
+        fts5BufferZero(&tmp);
+        sqlite3Fts5BufferSize(&p->rc, &tmp, i1.nPoslist + i2.nPoslist);
+        if( p->rc ) break;
+
+        sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
+        sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
+        assert( iPos1>=0 && iPos2>=0 );
+
+        if( iPos1<iPos2 ){
+          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
+          sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
+        }else{
+          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
+          sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
+        }
+
+        if( iPos1>=0 && iPos2>=0 ){
+          while( 1 ){
+            if( iPos1<iPos2 ){
+              if( iPos1!=iPrev ){
+                sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
+              }
+              sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
+              if( iPos1<0 ) break;
+            }else{
+              assert( iPos2!=iPrev );
+              sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
+              sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
+              if( iPos2<0 ) break;
+            }
+          }
+        }
+
+        if( iPos1>=0 ){
+          if( iPos1!=iPrev ){
+            sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
+          }
+          fts5BufferSafeAppendBlob(&tmp, &a1[iOff1], i1.nPoslist-iOff1);
+        }else{
+          assert( iPos2>=0 && iPos2!=iPrev );
+          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
+          fts5BufferSafeAppendBlob(&tmp, &a2[iOff2], i2.nPoslist-iOff2);
+        }
+
+        /* WRITEPOSLISTSIZE */
+        fts5BufferSafeAppendVarint(&out, tmp.n * 2);
+        fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
+        fts5DoclistIterNext(&i1);
+        fts5DoclistIterNext(&i2);
+        if( i1.aPoslist==0 || i2.aPoslist==0 ) break;
+      }
+    }
+
+    if( i1.aPoslist ){
+      fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
+      fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
+    }
+    else if( i2.aPoslist ){
+      fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
+      fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
+    }
+
+    fts5BufferSet(&p->rc, p1, out.n, out.p);
+    fts5BufferFree(&tmp);
+    fts5BufferFree(&out);
+  }
+}
+
+static void fts5SetupPrefixIter(
+  Fts5Index *p,                   /* Index to read from */
+  int bDesc,                      /* True for "ORDER BY rowid DESC" */
+  const u8 *pToken,               /* Buffer containing prefix to match */
+  int nToken,                     /* Size of buffer pToken in bytes */
+  Fts5Colset *pColset,            /* Restrict matches to these columns */
+  Fts5Iter **ppIter          /* OUT: New iterator */
+){
+  Fts5Structure *pStruct;
+  Fts5Buffer *aBuf;
+  const int nBuf = 32;
+
+  void (*xMerge)(Fts5Index*, Fts5Buffer*, Fts5Buffer*);
+  void (*xAppend)(Fts5Index*, i64, Fts5Iter*, Fts5Buffer*);
+  if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){
+    xMerge = fts5MergeRowidLists;
+    xAppend = fts5AppendRowid;
+  }else{
+    xMerge = fts5MergePrefixLists;
+    xAppend = fts5AppendPoslist;
+  }
+
+  aBuf = (Fts5Buffer*)fts5IdxMalloc(p, sizeof(Fts5Buffer)*nBuf);
+  pStruct = fts5StructureRead(p);
+
+  if( aBuf && pStruct ){
+    const int flags = FTS5INDEX_QUERY_SCAN 
+                    | FTS5INDEX_QUERY_SKIPEMPTY 
+                    | FTS5INDEX_QUERY_NOOUTPUT;
+    int i;
+    i64 iLastRowid = 0;
+    Fts5Iter *p1 = 0;     /* Iterator used to gather data from index */
+    Fts5Data *pData;
+    Fts5Buffer doclist;
+    int bNewTerm = 1;
+
+    memset(&doclist, 0, sizeof(doclist));
+    fts5MultiIterNew(p, pStruct, flags, pColset, pToken, nToken, -1, 0, &p1);
+    fts5IterSetOutputCb(&p->rc, p1);
+    for( /* no-op */ ;
+        fts5MultiIterEof(p, p1)==0;
+        fts5MultiIterNext2(p, p1, &bNewTerm)
+    ){
+      Fts5SegIter *pSeg = &p1->aSeg[ p1->aFirst[1].iFirst ];
+      int nTerm = pSeg->term.n;
+      const u8 *pTerm = pSeg->term.p;
+      p1->xSetOutputs(p1, pSeg);
+
+      assert_nc( memcmp(pToken, pTerm, MIN(nToken, nTerm))<=0 );
+      if( bNewTerm ){
+        if( nTerm<nToken || memcmp(pToken, pTerm, nToken) ) break;
+      }
+
+      if( p1->base.nData==0 ) continue;
+
+      if( p1->base.iRowid<=iLastRowid && doclist.n>0 ){
+        for(i=0; p->rc==SQLITE_OK && doclist.n; i++){
+          assert( i<nBuf );
+          if( aBuf[i].n==0 ){
+            fts5BufferSwap(&doclist, &aBuf[i]);
+            fts5BufferZero(&doclist);
+          }else{
+            xMerge(p, &doclist, &aBuf[i]);
+            fts5BufferZero(&aBuf[i]);
+          }
+        }
+        iLastRowid = 0;
+      }
+
+      xAppend(p, p1->base.iRowid-iLastRowid, p1, &doclist);
+      iLastRowid = p1->base.iRowid;
+    }
+
+    for(i=0; i<nBuf; i++){
+      if( p->rc==SQLITE_OK ){
+        xMerge(p, &doclist, &aBuf[i]);
+      }
+      fts5BufferFree(&aBuf[i]);
+    }
+    fts5MultiIterFree(p1);
+
+    pData = fts5IdxMalloc(p, sizeof(Fts5Data) + doclist.n);
+    if( pData ){
+      pData->p = (u8*)&pData[1];
+      pData->nn = pData->szLeaf = doclist.n;
+      memcpy(pData->p, doclist.p, doclist.n);
+      fts5MultiIterNew2(p, pData, bDesc, ppIter);
+    }
+    fts5BufferFree(&doclist);
+  }
+
+  fts5StructureRelease(pStruct);
+  sqlite3_free(aBuf);
+}
+
+
+/*
+** Indicate that all subsequent calls to sqlite3Fts5IndexWrite() pertain
+** to the document with rowid iRowid.
+*/
+static int sqlite3Fts5IndexBeginWrite(Fts5Index *p, int bDelete, i64 iRowid){
+  assert( p->rc==SQLITE_OK );
+
+  /* Allocate the hash table if it has not already been allocated */
+  if( p->pHash==0 ){
+    p->rc = sqlite3Fts5HashNew(p->pConfig, &p->pHash, &p->nPendingData);
+  }
+
+  /* Flush the hash table to disk if required */
+  if( iRowid<p->iWriteRowid 
+   || (iRowid==p->iWriteRowid && p->bDelete==0)
+   || (p->nPendingData > p->pConfig->nHashSize) 
+  ){
+    fts5IndexFlush(p);
+  }
+
+  p->iWriteRowid = iRowid;
+  p->bDelete = bDelete;
+  return fts5IndexReturn(p);
+}
+
+/*
+** Commit data to disk.
+*/
+static int sqlite3Fts5IndexSync(Fts5Index *p, int bCommit){
+  assert( p->rc==SQLITE_OK );
+  fts5IndexFlush(p);
+  if( bCommit ) fts5CloseReader(p);
+  return fts5IndexReturn(p);
+}
+
+/*
+** Discard any data stored in the in-memory hash tables. Do not write it
+** to the database. Additionally, assume that the contents of the %_data
+** table may have changed on disk. So any in-memory caches of %_data 
+** records must be invalidated.
+*/
+static int sqlite3Fts5IndexRollback(Fts5Index *p){
+  fts5CloseReader(p);
+  fts5IndexDiscardData(p);
+  fts5StructureInvalidate(p);
+  /* assert( p->rc==SQLITE_OK ); */
+  return SQLITE_OK;
+}
+
+/*
+** The %_data table is completely empty when this function is called. This
+** function populates it with the initial structure objects for each index,
+** and the initial version of the "averages" record (a zero-byte blob).
+*/
+static int sqlite3Fts5IndexReinit(Fts5Index *p){
+  Fts5Structure s;
+  fts5StructureInvalidate(p);
+  memset(&s, 0, sizeof(Fts5Structure));
+  fts5DataWrite(p, FTS5_AVERAGES_ROWID, (const u8*)"", 0);
+  fts5StructureWrite(p, &s);
+  return fts5IndexReturn(p);
+}
+
+/*
+** Open a new Fts5Index handle. If the bCreate argument is true, create
+** and initialize the underlying %_data table.
+**
+** If successful, set *pp to point to the new object and return SQLITE_OK.
+** Otherwise, set *pp to NULL and return an SQLite error code.
+*/
+static int sqlite3Fts5IndexOpen(
+  Fts5Config *pConfig, 
+  int bCreate, 
+  Fts5Index **pp,
+  char **pzErr
+){
+  int rc = SQLITE_OK;
+  Fts5Index *p;                   /* New object */
+
+  *pp = p = (Fts5Index*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Index));
+  if( rc==SQLITE_OK ){
+    p->pConfig = pConfig;
+    p->nWorkUnit = FTS5_WORK_UNIT;
+    p->zDataTbl = sqlite3Fts5Mprintf(&rc, "%s_data", pConfig->zName);
+    if( p->zDataTbl && bCreate ){
+      rc = sqlite3Fts5CreateTable(
+          pConfig, "data", "id INTEGER PRIMARY KEY, block BLOB", 0, pzErr
+      );
+      if( rc==SQLITE_OK ){
+        rc = sqlite3Fts5CreateTable(pConfig, "idx", 
+            "segid, term, pgno, PRIMARY KEY(segid, term)", 
+            1, pzErr
+        );
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3Fts5IndexReinit(p);
+      }
+    }
+  }
+
+  assert( rc!=SQLITE_OK || p->rc==SQLITE_OK );
+  if( rc ){
+    sqlite3Fts5IndexClose(p);
+    *pp = 0;
+  }
+  return rc;
+}
+
+/*
+** Close a handle opened by an earlier call to sqlite3Fts5IndexOpen().
+*/
+static int sqlite3Fts5IndexClose(Fts5Index *p){
+  int rc = SQLITE_OK;
+  if( p ){
+    assert( p->pReader==0 );
+    fts5StructureInvalidate(p);
+    sqlite3_finalize(p->pWriter);
+    sqlite3_finalize(p->pDeleter);
+    sqlite3_finalize(p->pIdxWriter);
+    sqlite3_finalize(p->pIdxDeleter);
+    sqlite3_finalize(p->pIdxSelect);
+    sqlite3_finalize(p->pDataVersion);
+    sqlite3Fts5HashFree(p->pHash);
+    sqlite3_free(p->zDataTbl);
+    sqlite3_free(p);
+  }
+  return rc;
+}
+
+/*
+** Argument p points to a buffer containing utf-8 text that is n bytes in 
+** size. Return the number of bytes in the nChar character prefix of the
+** buffer, or 0 if there are less than nChar characters in total.
+*/
+static int sqlite3Fts5IndexCharlenToBytelen(
+  const char *p, 
+  int nByte, 
+  int nChar
+){
+  int n = 0;
+  int i;
+  for(i=0; i<nChar; i++){
+    if( n>=nByte ) return 0;      /* Input contains fewer than nChar chars */
+    if( (unsigned char)p[n++]>=0xc0 ){
+      while( (p[n] & 0xc0)==0x80 ) n++;
+    }
+  }
+  return n;
+}
+
+/*
+** pIn is a UTF-8 encoded string, nIn bytes in size. Return the number of
+** unicode characters in the string.
+*/
+static int fts5IndexCharlen(const char *pIn, int nIn){
+  int nChar = 0;            
+  int i = 0;
+  while( i<nIn ){
+    if( (unsigned char)pIn[i++]>=0xc0 ){
+      while( i<nIn && (pIn[i] & 0xc0)==0x80 ) i++;
+    }
+    nChar++;
+  }
+  return nChar;
+}
+
+/*
+** Insert or remove data to or from the index. Each time a document is 
+** added to or removed from the index, this function is called one or more
+** times.
+**
+** For an insert, it must be called once for each token in the new document.
+** If the operation is a delete, it must be called (at least) once for each
+** unique token in the document with an iCol value less than zero. The iPos
+** argument is ignored for a delete.
+*/
+static int sqlite3Fts5IndexWrite(
+  Fts5Index *p,                   /* Index to write to */
+  int iCol,                       /* Column token appears in (-ve -> delete) */
+  int iPos,                       /* Position of token within column */
+  const char *pToken, int nToken  /* Token to add or remove to or from index */
+){
+  int i;                          /* Used to iterate through indexes */
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5Config *pConfig = p->pConfig;
+
+  assert( p->rc==SQLITE_OK );
+  assert( (iCol<0)==p->bDelete );
+
+  /* Add the entry to the main terms index. */
+  rc = sqlite3Fts5HashWrite(
+      p->pHash, p->iWriteRowid, iCol, iPos, FTS5_MAIN_PREFIX, pToken, nToken
+  );
+
+  for(i=0; i<pConfig->nPrefix && rc==SQLITE_OK; i++){
+    const int nChar = pConfig->aPrefix[i];
+    int nByte = sqlite3Fts5IndexCharlenToBytelen(pToken, nToken, nChar);
+    if( nByte ){
+      rc = sqlite3Fts5HashWrite(p->pHash, 
+          p->iWriteRowid, iCol, iPos, (char)(FTS5_MAIN_PREFIX+i+1), pToken,
+          nByte
+      );
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Open a new iterator to iterate though all rowid that match the 
+** specified token or token prefix.
+*/
+static int sqlite3Fts5IndexQuery(
+  Fts5Index *p,                   /* FTS index to query */
+  const char *pToken, int nToken, /* Token (or prefix) to query for */
+  int flags,                      /* Mask of FTS5INDEX_QUERY_X flags */
+  Fts5Colset *pColset,            /* Match these columns only */
+  Fts5IndexIter **ppIter          /* OUT: New iterator object */
+){
+  Fts5Config *pConfig = p->pConfig;
+  Fts5Iter *pRet = 0;
+  Fts5Buffer buf = {0, 0, 0};
+
+  /* If the QUERY_SCAN flag is set, all other flags must be clear. */
+  assert( (flags & FTS5INDEX_QUERY_SCAN)==0 || flags==FTS5INDEX_QUERY_SCAN );
+
+  if( sqlite3Fts5BufferSize(&p->rc, &buf, nToken+1)==0 ){
+    int iIdx = 0;                 /* Index to search */
+    memcpy(&buf.p[1], pToken, nToken);
+
+    /* Figure out which index to search and set iIdx accordingly. If this
+    ** is a prefix query for which there is no prefix index, set iIdx to
+    ** greater than pConfig->nPrefix to indicate that the query will be
+    ** satisfied by scanning multiple terms in the main index.
+    **
+    ** If the QUERY_TEST_NOIDX flag was specified, then this must be a
+    ** prefix-query. Instead of using a prefix-index (if one exists), 
+    ** evaluate the prefix query using the main FTS index. This is used
+    ** for internal sanity checking by the integrity-check in debug 
+    ** mode only.  */
+#ifdef SQLITE_DEBUG
+    if( pConfig->bPrefixIndex==0 || (flags & FTS5INDEX_QUERY_TEST_NOIDX) ){
+      assert( flags & FTS5INDEX_QUERY_PREFIX );
+      iIdx = 1+pConfig->nPrefix;
+    }else
+#endif
+    if( flags & FTS5INDEX_QUERY_PREFIX ){
+      int nChar = fts5IndexCharlen(pToken, nToken);
+      for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){
+        if( pConfig->aPrefix[iIdx-1]==nChar ) break;
+      }
+    }
+
+    if( iIdx<=pConfig->nPrefix ){
+      /* Straight index lookup */
+      Fts5Structure *pStruct = fts5StructureRead(p);
+      buf.p[0] = (u8)(FTS5_MAIN_PREFIX + iIdx);
+      if( pStruct ){
+        fts5MultiIterNew(p, pStruct, flags | FTS5INDEX_QUERY_SKIPEMPTY, 
+            pColset, buf.p, nToken+1, -1, 0, &pRet
+        );
+        fts5StructureRelease(pStruct);
+      }
+    }else{
+      /* Scan multiple terms in the main index */
+      int bDesc = (flags & FTS5INDEX_QUERY_DESC)!=0;
+      buf.p[0] = FTS5_MAIN_PREFIX;
+      fts5SetupPrefixIter(p, bDesc, buf.p, nToken+1, pColset, &pRet);
+      assert( p->rc!=SQLITE_OK || pRet->pColset==0 );
+      fts5IterSetOutputCb(&p->rc, pRet);
+      if( p->rc==SQLITE_OK ){
+        Fts5SegIter *pSeg = &pRet->aSeg[pRet->aFirst[1].iFirst];
+        if( pSeg->pLeaf ) pRet->xSetOutputs(pRet, pSeg);
+      }
+    }
+
+    if( p->rc ){
+      sqlite3Fts5IterClose(&pRet->base);
+      pRet = 0;
+      fts5CloseReader(p);
+    }
+
+    *ppIter = &pRet->base;
+    sqlite3Fts5BufferFree(&buf);
+  }
+  return fts5IndexReturn(p);
+}
+
+/*
+** Return true if the iterator passed as the only argument is at EOF.
+*/
+/*
+** Move to the next matching rowid. 
+*/
+static int sqlite3Fts5IterNext(Fts5IndexIter *pIndexIter){
+  Fts5Iter *pIter = (Fts5Iter*)pIndexIter;
+  assert( pIter->pIndex->rc==SQLITE_OK );
+  fts5MultiIterNext(pIter->pIndex, pIter, 0, 0);
+  return fts5IndexReturn(pIter->pIndex);
+}
+
+/*
+** Move to the next matching term/rowid. Used by the fts5vocab module.
+*/
+static int sqlite3Fts5IterNextScan(Fts5IndexIter *pIndexIter){
+  Fts5Iter *pIter = (Fts5Iter*)pIndexIter;
+  Fts5Index *p = pIter->pIndex;
+
+  assert( pIter->pIndex->rc==SQLITE_OK );
+
+  fts5MultiIterNext(p, pIter, 0, 0);
+  if( p->rc==SQLITE_OK ){
+    Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];
+    if( pSeg->pLeaf && pSeg->term.p[0]!=FTS5_MAIN_PREFIX ){
+      fts5DataRelease(pSeg->pLeaf);
+      pSeg->pLeaf = 0;
+      pIter->base.bEof = 1;
+    }
+  }
+
+  return fts5IndexReturn(pIter->pIndex);
+}
+
+/*
+** Move to the next matching rowid that occurs at or after iMatch. The
+** definition of "at or after" depends on whether this iterator iterates
+** in ascending or descending rowid order.
+*/
+static int sqlite3Fts5IterNextFrom(Fts5IndexIter *pIndexIter, i64 iMatch){
+  Fts5Iter *pIter = (Fts5Iter*)pIndexIter;
+  fts5MultiIterNextFrom(pIter->pIndex, pIter, iMatch);
+  return fts5IndexReturn(pIter->pIndex);
+}
+
+/*
+** Return the current term.
+*/
+static const char *sqlite3Fts5IterTerm(Fts5IndexIter *pIndexIter, int *pn){
+  int n;
+  const char *z = (const char*)fts5MultiIterTerm((Fts5Iter*)pIndexIter, &n);
+  *pn = n-1;
+  return &z[1];
+}
+
+/*
+** Close an iterator opened by an earlier call to sqlite3Fts5IndexQuery().
+*/
+static void sqlite3Fts5IterClose(Fts5IndexIter *pIndexIter){
+  if( pIndexIter ){
+    Fts5Iter *pIter = (Fts5Iter*)pIndexIter;
+    Fts5Index *pIndex = pIter->pIndex;
+    fts5MultiIterFree(pIter);
+    fts5CloseReader(pIndex);
+  }
+}
+
+/*
+** Read and decode the "averages" record from the database. 
+**
+** Parameter anSize must point to an array of size nCol, where nCol is
+** the number of user defined columns in the FTS table.
+*/
+static int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize){
+  int nCol = p->pConfig->nCol;
+  Fts5Data *pData;
+
+  *pnRow = 0;
+  memset(anSize, 0, sizeof(i64) * nCol);
+  pData = fts5DataRead(p, FTS5_AVERAGES_ROWID);
+  if( p->rc==SQLITE_OK && pData->nn ){
+    int i = 0;
+    int iCol;
+    i += fts5GetVarint(&pData->p[i], (u64*)pnRow);
+    for(iCol=0; i<pData->nn && iCol<nCol; iCol++){
+      i += fts5GetVarint(&pData->p[i], (u64*)&anSize[iCol]);
+    }
+  }
+
+  fts5DataRelease(pData);
+  return fts5IndexReturn(p);
+}
+
+/*
+** Replace the current "averages" record with the contents of the buffer 
+** supplied as the second argument.
+*/
+static int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8 *pData, int nData){
+  assert( p->rc==SQLITE_OK );
+  fts5DataWrite(p, FTS5_AVERAGES_ROWID, pData, nData);
+  return fts5IndexReturn(p);
+}
+
+/*
+** Return the total number of blocks this module has read from the %_data
+** table since it was created.
+*/
+static int sqlite3Fts5IndexReads(Fts5Index *p){
+  return p->nRead;
+}
+
+/*
+** Set the 32-bit cookie value stored at the start of all structure 
+** records to the value passed as the second argument.
+**
+** Return SQLITE_OK if successful, or an SQLite error code if an error
+** occurs.
+*/
+static int sqlite3Fts5IndexSetCookie(Fts5Index *p, int iNew){
+  int rc;                              /* Return code */
+  Fts5Config *pConfig = p->pConfig;    /* Configuration object */
+  u8 aCookie[4];                       /* Binary representation of iNew */
+  sqlite3_blob *pBlob = 0;
+
+  assert( p->rc==SQLITE_OK );
+  sqlite3Fts5Put32(aCookie, iNew);
+
+  rc = sqlite3_blob_open(pConfig->db, pConfig->zDb, p->zDataTbl, 
+      "block", FTS5_STRUCTURE_ROWID, 1, &pBlob
+  );
+  if( rc==SQLITE_OK ){
+    sqlite3_blob_write(pBlob, aCookie, 4, 0);
+    rc = sqlite3_blob_close(pBlob);
+  }
+
+  return rc;
+}
+
+static int sqlite3Fts5IndexLoadConfig(Fts5Index *p){
+  Fts5Structure *pStruct;
+  pStruct = fts5StructureRead(p);
+  fts5StructureRelease(pStruct);
+  return fts5IndexReturn(p);
+}
+
+
+/*************************************************************************
+**************************************************************************
+** Below this point is the implementation of the integrity-check 
+** functionality.
+*/
+
+/*
+** Return a simple checksum value based on the arguments.
+*/
+static u64 sqlite3Fts5IndexEntryCksum(
+  i64 iRowid, 
+  int iCol, 
+  int iPos, 
+  int iIdx,
+  const char *pTerm,
+  int nTerm
+){
+  int i;
+  u64 ret = iRowid;
+  ret += (ret<<3) + iCol;
+  ret += (ret<<3) + iPos;
+  if( iIdx>=0 ) ret += (ret<<3) + (FTS5_MAIN_PREFIX + iIdx);
+  for(i=0; i<nTerm; i++) ret += (ret<<3) + pTerm[i];
+  return ret;
+}
+
+#ifdef SQLITE_DEBUG
+/*
+** This function is purely an internal test. It does not contribute to 
+** FTS functionality, or even the integrity-check, in any way.
+**
+** Instead, it tests that the same set of pgno/rowid combinations are 
+** visited regardless of whether the doclist-index identified by parameters
+** iSegid/iLeaf is iterated in forwards or reverse order.
+*/
+static void fts5TestDlidxReverse(
+  Fts5Index *p, 
+  int iSegid,                     /* Segment id to load from */
+  int iLeaf                       /* Load doclist-index for this leaf */
+){
+  Fts5DlidxIter *pDlidx = 0;
+  u64 cksum1 = 13;
+  u64 cksum2 = 13;
+
+  for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iLeaf);
+      fts5DlidxIterEof(p, pDlidx)==0;
+      fts5DlidxIterNext(p, pDlidx)
+  ){
+    i64 iRowid = fts5DlidxIterRowid(pDlidx);
+    int pgno = fts5DlidxIterPgno(pDlidx);
+    assert( pgno>iLeaf );
+    cksum1 += iRowid + ((i64)pgno<<32);
+  }
+  fts5DlidxIterFree(pDlidx);
+  pDlidx = 0;
+
+  for(pDlidx=fts5DlidxIterInit(p, 1, iSegid, iLeaf);
+      fts5DlidxIterEof(p, pDlidx)==0;
+      fts5DlidxIterPrev(p, pDlidx)
+  ){
+    i64 iRowid = fts5DlidxIterRowid(pDlidx);
+    int pgno = fts5DlidxIterPgno(pDlidx);
+    assert( fts5DlidxIterPgno(pDlidx)>iLeaf );
+    cksum2 += iRowid + ((i64)pgno<<32);
+  }
+  fts5DlidxIterFree(pDlidx);
+  pDlidx = 0;
+
+  if( p->rc==SQLITE_OK && cksum1!=cksum2 ) p->rc = FTS5_CORRUPT;
+}
+
+static int fts5QueryCksum(
+  Fts5Index *p,                   /* Fts5 index object */
+  int iIdx,
+  const char *z,                  /* Index key to query for */
+  int n,                          /* Size of index key in bytes */
+  int flags,                      /* Flags for Fts5IndexQuery */
+  u64 *pCksum                     /* IN/OUT: Checksum value */
+){
+  int eDetail = p->pConfig->eDetail;
+  u64 cksum = *pCksum;
+  Fts5IndexIter *pIter = 0;
+  int rc = sqlite3Fts5IndexQuery(p, z, n, flags, 0, &pIter);
+
+  while( rc==SQLITE_OK && 0==sqlite3Fts5IterEof(pIter) ){
+    i64 rowid = pIter->iRowid;
+
+    if( eDetail==FTS5_DETAIL_NONE ){
+      cksum ^= sqlite3Fts5IndexEntryCksum(rowid, 0, 0, iIdx, z, n);
+    }else{
+      Fts5PoslistReader sReader;
+      for(sqlite3Fts5PoslistReaderInit(pIter->pData, pIter->nData, &sReader);
+          sReader.bEof==0;
+          sqlite3Fts5PoslistReaderNext(&sReader)
+      ){
+        int iCol = FTS5_POS2COLUMN(sReader.iPos);
+        int iOff = FTS5_POS2OFFSET(sReader.iPos);
+        cksum ^= sqlite3Fts5IndexEntryCksum(rowid, iCol, iOff, iIdx, z, n);
+      }
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts5IterNext(pIter);
+    }
+  }
+  sqlite3Fts5IterClose(pIter);
+
+  *pCksum = cksum;
+  return rc;
+}
+
+
+/*
+** This function is also purely an internal test. It does not contribute to 
+** FTS functionality, or even the integrity-check, in any way.
+*/
+static void fts5TestTerm(
+  Fts5Index *p, 
+  Fts5Buffer *pPrev,              /* Previous term */
+  const char *z, int n,           /* Possibly new term to test */
+  u64 expected,
+  u64 *pCksum
+){
+  int rc = p->rc;
+  if( pPrev->n==0 ){
+    fts5BufferSet(&rc, pPrev, n, (const u8*)z);
+  }else
+  if( rc==SQLITE_OK && (pPrev->n!=n || memcmp(pPrev->p, z, n)) ){
+    u64 cksum3 = *pCksum;
+    const char *zTerm = (const char*)&pPrev->p[1];  /* term sans prefix-byte */
+    int nTerm = pPrev->n-1;            /* Size of zTerm in bytes */
+    int iIdx = (pPrev->p[0] - FTS5_MAIN_PREFIX);
+    int flags = (iIdx==0 ? 0 : FTS5INDEX_QUERY_PREFIX);
+    u64 ck1 = 0;
+    u64 ck2 = 0;
+
+    /* Check that the results returned for ASC and DESC queries are
+    ** the same. If not, call this corruption.  */
+    rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, flags, &ck1);
+    if( rc==SQLITE_OK ){
+      int f = flags|FTS5INDEX_QUERY_DESC;
+      rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
+    }
+    if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
+
+    /* If this is a prefix query, check that the results returned if the
+    ** the index is disabled are the same. In both ASC and DESC order. 
+    **
+    ** This check may only be performed if the hash table is empty. This
+    ** is because the hash table only supports a single scan query at
+    ** a time, and the multi-iter loop from which this function is called
+    ** is already performing such a scan. */
+    if( p->nPendingData==0 ){
+      if( iIdx>0 && rc==SQLITE_OK ){
+        int f = flags|FTS5INDEX_QUERY_TEST_NOIDX;
+        ck2 = 0;
+        rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
+        if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
+      }
+      if( iIdx>0 && rc==SQLITE_OK ){
+        int f = flags|FTS5INDEX_QUERY_TEST_NOIDX|FTS5INDEX_QUERY_DESC;
+        ck2 = 0;
+        rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);
+        if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;
+      }
+    }
+
+    cksum3 ^= ck1;
+    fts5BufferSet(&rc, pPrev, n, (const u8*)z);
+
+    if( rc==SQLITE_OK && cksum3!=expected ){
+      rc = FTS5_CORRUPT;
+    }
+    *pCksum = cksum3;
+  }
+  p->rc = rc;
+}
+ 
+#else
+# define fts5TestDlidxReverse(x,y,z)
+# define fts5TestTerm(u,v,w,x,y,z)
+#endif
+
+/*
+** Check that:
+**
+**   1) All leaves of pSeg between iFirst and iLast (inclusive) exist and
+**      contain zero terms.
+**   2) All leaves of pSeg between iNoRowid and iLast (inclusive) exist and
+**      contain zero rowids.
+*/
+static void fts5IndexIntegrityCheckEmpty(
+  Fts5Index *p,
+  Fts5StructureSegment *pSeg,     /* Segment to check internal consistency */
+  int iFirst,
+  int iNoRowid,
+  int iLast
+){
+  int i;
+
+  /* Now check that the iter.nEmpty leaves following the current leaf
+  ** (a) exist and (b) contain no terms. */
+  for(i=iFirst; p->rc==SQLITE_OK && i<=iLast; i++){
+    Fts5Data *pLeaf = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, i));
+    if( pLeaf ){
+      if( !fts5LeafIsTermless(pLeaf) ) p->rc = FTS5_CORRUPT;
+      if( i>=iNoRowid && 0!=fts5LeafFirstRowidOff(pLeaf) ) p->rc = FTS5_CORRUPT;
+    }
+    fts5DataRelease(pLeaf);
+  }
+}
+
+static void fts5IntegrityCheckPgidx(Fts5Index *p, Fts5Data *pLeaf){
+  int iTermOff = 0;
+  int ii;
+
+  Fts5Buffer buf1 = {0,0,0};
+  Fts5Buffer buf2 = {0,0,0};
+
+  ii = pLeaf->szLeaf;
+  while( ii<pLeaf->nn && p->rc==SQLITE_OK ){
+    int res;
+    int iOff;
+    int nIncr;
+
+    ii += fts5GetVarint32(&pLeaf->p[ii], nIncr);
+    iTermOff += nIncr;
+    iOff = iTermOff;
+
+    if( iOff>=pLeaf->szLeaf ){
+      p->rc = FTS5_CORRUPT;
+    }else if( iTermOff==nIncr ){
+      int nByte;
+      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
+      if( (iOff+nByte)>pLeaf->szLeaf ){
+        p->rc = FTS5_CORRUPT;
+      }else{
+        fts5BufferSet(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
+      }
+    }else{
+      int nKeep, nByte;
+      iOff += fts5GetVarint32(&pLeaf->p[iOff], nKeep);
+      iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);
+      if( nKeep>buf1.n || (iOff+nByte)>pLeaf->szLeaf ){
+        p->rc = FTS5_CORRUPT;
+      }else{
+        buf1.n = nKeep;
+        fts5BufferAppendBlob(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);
+      }
+
+      if( p->rc==SQLITE_OK ){
+        res = fts5BufferCompare(&buf1, &buf2);
+        if( res<=0 ) p->rc = FTS5_CORRUPT;
+      }
+    }
+    fts5BufferSet(&p->rc, &buf2, buf1.n, buf1.p);
+  }
+
+  fts5BufferFree(&buf1);
+  fts5BufferFree(&buf2);
+}
+
+static void fts5IndexIntegrityCheckSegment(
+  Fts5Index *p,                   /* FTS5 backend object */
+  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
+){
+  Fts5Config *pConfig = p->pConfig;
+  sqlite3_stmt *pStmt = 0;
+  int rc2;
+  int iIdxPrevLeaf = pSeg->pgnoFirst-1;
+  int iDlidxPrevLeaf = pSeg->pgnoLast;
+
+  if( pSeg->pgnoFirst==0 ) return;
+
+  fts5IndexPrepareStmt(p, &pStmt, sqlite3_mprintf(
+      "SELECT segid, term, (pgno>>1), (pgno&1) FROM %Q.'%q_idx' WHERE segid=%d",
+      pConfig->zDb, pConfig->zName, pSeg->iSegid
+  ));
+
+  /* Iterate through the b-tree hierarchy.  */
+  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+    i64 iRow;                     /* Rowid for this leaf */
+    Fts5Data *pLeaf;              /* Data for this leaf */
+
+    int nIdxTerm = sqlite3_column_bytes(pStmt, 1);
+    const char *zIdxTerm = (const char*)sqlite3_column_text(pStmt, 1);
+    int iIdxLeaf = sqlite3_column_int(pStmt, 2);
+    int bIdxDlidx = sqlite3_column_int(pStmt, 3);
+
+    /* If the leaf in question has already been trimmed from the segment, 
+    ** ignore this b-tree entry. Otherwise, load it into memory. */
+    if( iIdxLeaf<pSeg->pgnoFirst ) continue;
+    iRow = FTS5_SEGMENT_ROWID(pSeg->iSegid, iIdxLeaf);
+    pLeaf = fts5DataRead(p, iRow);
+    if( pLeaf==0 ) break;
+
+    /* Check that the leaf contains at least one term, and that it is equal
+    ** to or larger than the split-key in zIdxTerm.  Also check that if there
+    ** is also a rowid pointer within the leaf page header, it points to a
+    ** location before the term.  */
+    if( pLeaf->nn<=pLeaf->szLeaf ){
+      p->rc = FTS5_CORRUPT;
+    }else{
+      int iOff;                   /* Offset of first term on leaf */
+      int iRowidOff;              /* Offset of first rowid on leaf */
+      int nTerm;                  /* Size of term on leaf in bytes */
+      int res;                    /* Comparison of term and split-key */
+
+      iOff = fts5LeafFirstTermOff(pLeaf);
+      iRowidOff = fts5LeafFirstRowidOff(pLeaf);
+      if( iRowidOff>=iOff ){
+        p->rc = FTS5_CORRUPT;
+      }else{
+        iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);
+        res = memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));
+        if( res==0 ) res = nTerm - nIdxTerm;
+        if( res<0 ) p->rc = FTS5_CORRUPT;
+      }
+
+      fts5IntegrityCheckPgidx(p, pLeaf);
+    }
+    fts5DataRelease(pLeaf);
+    if( p->rc ) break;
+
+    /* Now check that the iter.nEmpty leaves following the current leaf
+    ** (a) exist and (b) contain no terms. */
+    fts5IndexIntegrityCheckEmpty(
+        p, pSeg, iIdxPrevLeaf+1, iDlidxPrevLeaf+1, iIdxLeaf-1
+    );
+    if( p->rc ) break;
+
+    /* If there is a doclist-index, check that it looks right. */
+    if( bIdxDlidx ){
+      Fts5DlidxIter *pDlidx = 0;  /* For iterating through doclist index */
+      int iPrevLeaf = iIdxLeaf;
+      int iSegid = pSeg->iSegid;
+      int iPg = 0;
+      i64 iKey;
+
+      for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iIdxLeaf);
+          fts5DlidxIterEof(p, pDlidx)==0;
+          fts5DlidxIterNext(p, pDlidx)
+      ){
+
+        /* Check any rowid-less pages that occur before the current leaf. */
+        for(iPg=iPrevLeaf+1; iPg<fts5DlidxIterPgno(pDlidx); iPg++){
+          iKey = FTS5_SEGMENT_ROWID(iSegid, iPg);
+          pLeaf = fts5DataRead(p, iKey);
+          if( pLeaf ){
+            if( fts5LeafFirstRowidOff(pLeaf)!=0 ) p->rc = FTS5_CORRUPT;
+            fts5DataRelease(pLeaf);
+          }
+        }
+        iPrevLeaf = fts5DlidxIterPgno(pDlidx);
+
+        /* Check that the leaf page indicated by the iterator really does
+        ** contain the rowid suggested by the same. */
+        iKey = FTS5_SEGMENT_ROWID(iSegid, iPrevLeaf);
+        pLeaf = fts5DataRead(p, iKey);
+        if( pLeaf ){
+          i64 iRowid;
+          int iRowidOff = fts5LeafFirstRowidOff(pLeaf);
+          ASSERT_SZLEAF_OK(pLeaf);
+          if( iRowidOff>=pLeaf->szLeaf ){
+            p->rc = FTS5_CORRUPT;
+          }else{
+            fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);
+            if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;
+          }
+          fts5DataRelease(pLeaf);
+        }
+      }
+
+      iDlidxPrevLeaf = iPg;
+      fts5DlidxIterFree(pDlidx);
+      fts5TestDlidxReverse(p, iSegid, iIdxLeaf);
+    }else{
+      iDlidxPrevLeaf = pSeg->pgnoLast;
+      /* TODO: Check there is no doclist index */
+    }
+
+    iIdxPrevLeaf = iIdxLeaf;
+  }
+
+  rc2 = sqlite3_finalize(pStmt);
+  if( p->rc==SQLITE_OK ) p->rc = rc2;
+
+  /* Page iter.iLeaf must now be the rightmost leaf-page in the segment */
+#if 0
+  if( p->rc==SQLITE_OK && iter.iLeaf!=pSeg->pgnoLast ){
+    p->rc = FTS5_CORRUPT;
+  }
+#endif
+}
+
+
+/*
+** Run internal checks to ensure that the FTS index (a) is internally 
+** consistent and (b) contains entries for which the XOR of the checksums
+** as calculated by sqlite3Fts5IndexEntryCksum() is cksum.
+**
+** Return SQLITE_CORRUPT if any of the internal checks fail, or if the
+** checksum does not match. Return SQLITE_OK if all checks pass without
+** error, or some other SQLite error code if another error (e.g. OOM)
+** occurs.
+*/
+static int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){
+  int eDetail = p->pConfig->eDetail;
+  u64 cksum2 = 0;                 /* Checksum based on contents of indexes */
+  Fts5Buffer poslist = {0,0,0};   /* Buffer used to hold a poslist */
+  Fts5Iter *pIter;                /* Used to iterate through entire index */
+  Fts5Structure *pStruct;         /* Index structure */
+
+#ifdef SQLITE_DEBUG
+  /* Used by extra internal tests only run if NDEBUG is not defined */
+  u64 cksum3 = 0;                 /* Checksum based on contents of indexes */
+  Fts5Buffer term = {0,0,0};      /* Buffer used to hold most recent term */
+#endif
+  const int flags = FTS5INDEX_QUERY_NOOUTPUT;
+  
+  /* Load the FTS index structure */
+  pStruct = fts5StructureRead(p);
+
+  /* Check that the internal nodes of each segment match the leaves */
+  if( pStruct ){
+    int iLvl, iSeg;
+    for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){
+      for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){
+        Fts5StructureSegment *pSeg = &pStruct->aLevel[iLvl].aSeg[iSeg];
+        fts5IndexIntegrityCheckSegment(p, pSeg);
+      }
+    }
+  }
+
+  /* The cksum argument passed to this function is a checksum calculated
+  ** based on all expected entries in the FTS index (including prefix index
+  ** entries). This block checks that a checksum calculated based on the
+  ** actual contents of FTS index is identical.
+  **
+  ** Two versions of the same checksum are calculated. The first (stack
+  ** variable cksum2) based on entries extracted from the full-text index
+  ** while doing a linear scan of each individual index in turn. 
+  **
+  ** As each term visited by the linear scans, a separate query for the
+  ** same term is performed. cksum3 is calculated based on the entries
+  ** extracted by these queries.
+  */
+  for(fts5MultiIterNew(p, pStruct, flags, 0, 0, 0, -1, 0, &pIter);
+      fts5MultiIterEof(p, pIter)==0;
+      fts5MultiIterNext(p, pIter, 0, 0)
+  ){
+    int n;                      /* Size of term in bytes */
+    i64 iPos = 0;               /* Position read from poslist */
+    int iOff = 0;               /* Offset within poslist */
+    i64 iRowid = fts5MultiIterRowid(pIter);
+    char *z = (char*)fts5MultiIterTerm(pIter, &n);
+
+    /* If this is a new term, query for it. Update cksum3 with the results. */
+    fts5TestTerm(p, &term, z, n, cksum2, &cksum3);
+
+    if( eDetail==FTS5_DETAIL_NONE ){
+      if( 0==fts5MultiIterIsEmpty(p, pIter) ){
+        cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, 0, 0, -1, z, n);
+      }
+    }else{
+      poslist.n = 0;
+      fts5SegiterPoslist(p, &pIter->aSeg[pIter->aFirst[1].iFirst], 0, &poslist);
+      while( 0==sqlite3Fts5PoslistNext64(poslist.p, poslist.n, &iOff, &iPos) ){
+        int iCol = FTS5_POS2COLUMN(iPos);
+        int iTokOff = FTS5_POS2OFFSET(iPos);
+        cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, iCol, iTokOff, -1, z, n);
+      }
+    }
+  }
+  fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3);
+
+  fts5MultiIterFree(pIter);
+  if( p->rc==SQLITE_OK && cksum!=cksum2 ) p->rc = FTS5_CORRUPT;
+
+  fts5StructureRelease(pStruct);
+#ifdef SQLITE_DEBUG
+  fts5BufferFree(&term);
+#endif
+  fts5BufferFree(&poslist);
+  return fts5IndexReturn(p);
+}
+
+/*************************************************************************
+**************************************************************************
+** Below this point is the implementation of the fts5_decode() scalar
+** function only.
+*/
+
+/*
+** Decode a segment-data rowid from the %_data table. This function is
+** the opposite of macro FTS5_SEGMENT_ROWID().
+*/
+static void fts5DecodeRowid(
+  i64 iRowid,                     /* Rowid from %_data table */
+  int *piSegid,                   /* OUT: Segment id */
+  int *pbDlidx,                   /* OUT: Dlidx flag */
+  int *piHeight,                  /* OUT: Height */
+  int *piPgno                     /* OUT: Page number */
+){
+  *piPgno = (int)(iRowid & (((i64)1 << FTS5_DATA_PAGE_B) - 1));
+  iRowid >>= FTS5_DATA_PAGE_B;
+
+  *piHeight = (int)(iRowid & (((i64)1 << FTS5_DATA_HEIGHT_B) - 1));
+  iRowid >>= FTS5_DATA_HEIGHT_B;
+
+  *pbDlidx = (int)(iRowid & 0x0001);
+  iRowid >>= FTS5_DATA_DLI_B;
+
+  *piSegid = (int)(iRowid & (((i64)1 << FTS5_DATA_ID_B) - 1));
+}
+
+static void fts5DebugRowid(int *pRc, Fts5Buffer *pBuf, i64 iKey){
+  int iSegid, iHeight, iPgno, bDlidx;       /* Rowid compenents */
+  fts5DecodeRowid(iKey, &iSegid, &bDlidx, &iHeight, &iPgno);
+
+  if( iSegid==0 ){
+    if( iKey==FTS5_AVERAGES_ROWID ){
+      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{averages} ");
+    }else{
+      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{structure}");
+    }
+  }
+  else{
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{%ssegid=%d h=%d pgno=%d}",
+        bDlidx ? "dlidx " : "", iSegid, iHeight, iPgno
+    );
+  }
+}
+
+static void fts5DebugStructure(
+  int *pRc,                       /* IN/OUT: error code */
+  Fts5Buffer *pBuf,
+  Fts5Structure *p
+){
+  int iLvl, iSeg;                 /* Iterate through levels, segments */
+
+  for(iLvl=0; iLvl<p->nLevel; iLvl++){
+    Fts5StructureLevel *pLvl = &p->aLevel[iLvl];
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, 
+        " {lvl=%d nMerge=%d nSeg=%d", iLvl, pLvl->nMerge, pLvl->nSeg
+    );
+    for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){
+      Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];
+      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " {id=%d leaves=%d..%d}", 
+          pSeg->iSegid, pSeg->pgnoFirst, pSeg->pgnoLast
+      );
+    }
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "}");
+  }
+}
+
+/*
+** This is part of the fts5_decode() debugging aid.
+**
+** Arguments pBlob/nBlob contain a serialized Fts5Structure object. This
+** function appends a human-readable representation of the same object
+** to the buffer passed as the second argument. 
+*/
+static void fts5DecodeStructure(
+  int *pRc,                       /* IN/OUT: error code */
+  Fts5Buffer *pBuf,
+  const u8 *pBlob, int nBlob
+){
+  int rc;                         /* Return code */
+  Fts5Structure *p = 0;           /* Decoded structure object */
+
+  rc = fts5StructureDecode(pBlob, nBlob, 0, &p);
+  if( rc!=SQLITE_OK ){
+    *pRc = rc;
+    return;
+  }
+
+  fts5DebugStructure(pRc, pBuf, p);
+  fts5StructureRelease(p);
+}
+
+/*
+** This is part of the fts5_decode() debugging aid.
+**
+** Arguments pBlob/nBlob contain an "averages" record. This function 
+** appends a human-readable representation of record to the buffer passed 
+** as the second argument. 
+*/
+static void fts5DecodeAverages(
+  int *pRc,                       /* IN/OUT: error code */
+  Fts5Buffer *pBuf,
+  const u8 *pBlob, int nBlob
+){
+  int i = 0;
+  const char *zSpace = "";
+
+  while( i<nBlob ){
+    u64 iVal;
+    i += sqlite3Fts5GetVarint(&pBlob[i], &iVal);
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "%s%d", zSpace, (int)iVal);
+    zSpace = " ";
+  }
+}
+
+/*
+** Buffer (a/n) is assumed to contain a list of serialized varints. Read
+** each varint and append its string representation to buffer pBuf. Return
+** after either the input buffer is exhausted or a 0 value is read.
+**
+** The return value is the number of bytes read from the input buffer.
+*/
+static int fts5DecodePoslist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){
+  int iOff = 0;
+  while( iOff<n ){
+    int iVal;
+    iOff += fts5GetVarint32(&a[iOff], iVal);
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " %d", iVal);
+  }
+  return iOff;
+}
+
+/*
+** The start of buffer (a/n) contains the start of a doclist. The doclist
+** may or may not finish within the buffer. This function appends a text
+** representation of the part of the doclist that is present to buffer
+** pBuf. 
+**
+** The return value is the number of bytes read from the input buffer.
+*/
+static int fts5DecodeDoclist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){
+  i64 iDocid = 0;
+  int iOff = 0;
+
+  if( n>0 ){
+    iOff = sqlite3Fts5GetVarint(a, (u64*)&iDocid);
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);
+  }
+  while( iOff<n ){
+    int nPos;
+    int bDel;
+    iOff += fts5GetPoslistSize(&a[iOff], &nPos, &bDel);
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " nPos=%d%s", nPos, bDel?"*":"");
+    iOff += fts5DecodePoslist(pRc, pBuf, &a[iOff], MIN(n-iOff, nPos));
+    if( iOff<n ){
+      i64 iDelta;
+      iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&iDelta);
+      iDocid += iDelta;
+      sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);
+    }
+  }
+
+  return iOff;
+}
+
+/*
+** This function is part of the fts5_decode() debugging function. It is 
+** only ever used with detail=none tables.
+**
+** Buffer (pData/nData) contains a doclist in the format used by detail=none
+** tables. This function appends a human-readable version of that list to
+** buffer pBuf.
+**
+** If *pRc is other than SQLITE_OK when this function is called, it is a
+** no-op. If an OOM or other error occurs within this function, *pRc is
+** set to an SQLite error code before returning. The final state of buffer
+** pBuf is undefined in this case.
+*/
+static void fts5DecodeRowidList(
+  int *pRc,                       /* IN/OUT: Error code */
+  Fts5Buffer *pBuf,               /* Buffer to append text to */
+  const u8 *pData, int nData      /* Data to decode list-of-rowids from */
+){
+  int i = 0;
+  i64 iRowid = 0;
+
+  while( i<nData ){
+    const char *zApp = "";
+    u64 iVal;
+    i += sqlite3Fts5GetVarint(&pData[i], &iVal);
+    iRowid += iVal;
+
+    if( i<nData && pData[i]==0x00 ){
+      i++;
+      if( i<nData && pData[i]==0x00 ){
+        i++;
+        zApp = "+";
+      }else{
+        zApp = "*";
+      }
+    }
+
+    sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " %lld%s", iRowid, zApp);
+  }
+}
+
+/*
+** The implementation of user-defined scalar function fts5_decode().
+*/
+static void fts5DecodeFunction(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args (always 2) */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  i64 iRowid;                     /* Rowid for record being decoded */
+  int iSegid,iHeight,iPgno,bDlidx;/* Rowid components */
+  const u8 *aBlob; int n;         /* Record to decode */
+  u8 *a = 0;
+  Fts5Buffer s;                   /* Build up text to return here */
+  int rc = SQLITE_OK;             /* Return code */
+  int nSpace = 0;
+  int eDetailNone = (sqlite3_user_data(pCtx)!=0);
+
+  assert( nArg==2 );
+  UNUSED_PARAM(nArg);
+  memset(&s, 0, sizeof(Fts5Buffer));
+  iRowid = sqlite3_value_int64(apVal[0]);
+
+  /* Make a copy of the second argument (a blob) in aBlob[]. The aBlob[]
+  ** copy is followed by FTS5_DATA_ZERO_PADDING 0x00 bytes, which prevents
+  ** buffer overreads even if the record is corrupt.  */
+  n = sqlite3_value_bytes(apVal[1]);
+  aBlob = sqlite3_value_blob(apVal[1]);
+  nSpace = n + FTS5_DATA_ZERO_PADDING;
+  a = (u8*)sqlite3Fts5MallocZero(&rc, nSpace);
+  if( a==0 ) goto decode_out;
+  memcpy(a, aBlob, n);
+
+
+  fts5DecodeRowid(iRowid, &iSegid, &bDlidx, &iHeight, &iPgno);
+
+  fts5DebugRowid(&rc, &s, iRowid);
+  if( bDlidx ){
+    Fts5Data dlidx;
+    Fts5DlidxLvl lvl;
+
+    dlidx.p = a;
+    dlidx.nn = n;
+
+    memset(&lvl, 0, sizeof(Fts5DlidxLvl));
+    lvl.pData = &dlidx;
+    lvl.iLeafPgno = iPgno;
+
+    for(fts5DlidxLvlNext(&lvl); lvl.bEof==0; fts5DlidxLvlNext(&lvl)){
+      sqlite3Fts5BufferAppendPrintf(&rc, &s, 
+          " %d(%lld)", lvl.iLeafPgno, lvl.iRowid
+      );
+    }
+  }else if( iSegid==0 ){
+    if( iRowid==FTS5_AVERAGES_ROWID ){
+      fts5DecodeAverages(&rc, &s, a, n);
+    }else{
+      fts5DecodeStructure(&rc, &s, a, n);
+    }
+  }else if( eDetailNone ){
+    Fts5Buffer term;              /* Current term read from page */
+    int szLeaf;
+    int iPgidxOff = szLeaf = fts5GetU16(&a[2]);
+    int iTermOff;
+    int nKeep = 0;
+    int iOff;
+
+    memset(&term, 0, sizeof(Fts5Buffer));
+
+    /* Decode any entries that occur before the first term. */
+    if( szLeaf<n ){
+      iPgidxOff += fts5GetVarint32(&a[iPgidxOff], iTermOff);
+    }else{
+      iTermOff = szLeaf;
+    }
+    fts5DecodeRowidList(&rc, &s, &a[4], iTermOff-4);
+
+    iOff = iTermOff;
+    while( iOff<szLeaf ){
+      int nAppend;
+
+      /* Read the term data for the next term*/
+      iOff += fts5GetVarint32(&a[iOff], nAppend);
+      term.n = nKeep;
+      fts5BufferAppendBlob(&rc, &term, nAppend, &a[iOff]);
+      sqlite3Fts5BufferAppendPrintf(
+          &rc, &s, " term=%.*s", term.n, (const char*)term.p
+      );
+      iOff += nAppend;
+
+      /* Figure out where the doclist for this term ends */
+      if( iPgidxOff<n ){
+        int nIncr;
+        iPgidxOff += fts5GetVarint32(&a[iPgidxOff], nIncr);
+        iTermOff += nIncr;
+      }else{
+        iTermOff = szLeaf;
+      }
+
+      fts5DecodeRowidList(&rc, &s, &a[iOff], iTermOff-iOff);
+      iOff = iTermOff;
+      if( iOff<szLeaf ){
+        iOff += fts5GetVarint32(&a[iOff], nKeep);
+      }
+    }
+
+    fts5BufferFree(&term);
+  }else{
+    Fts5Buffer term;              /* Current term read from page */
+    int szLeaf;                   /* Offset of pgidx in a[] */
+    int iPgidxOff;
+    int iPgidxPrev = 0;           /* Previous value read from pgidx */
+    int iTermOff = 0;
+    int iRowidOff = 0;
+    int iOff;
+    int nDoclist;
+
+    memset(&term, 0, sizeof(Fts5Buffer));
+
+    if( n<4 ){
+      sqlite3Fts5BufferSet(&rc, &s, 7, (const u8*)"corrupt");
+      goto decode_out;
+    }else{
+      iRowidOff = fts5GetU16(&a[0]);
+      iPgidxOff = szLeaf = fts5GetU16(&a[2]);
+      if( iPgidxOff<n ){
+        fts5GetVarint32(&a[iPgidxOff], iTermOff);
+      }
+    }
+
+    /* Decode the position list tail at the start of the page */
+    if( iRowidOff!=0 ){
+      iOff = iRowidOff;
+    }else if( iTermOff!=0 ){
+      iOff = iTermOff;
+    }else{
+      iOff = szLeaf;
+    }
+    fts5DecodePoslist(&rc, &s, &a[4], iOff-4);
+
+    /* Decode any more doclist data that appears on the page before the
+    ** first term. */
+    nDoclist = (iTermOff ? iTermOff : szLeaf) - iOff;
+    fts5DecodeDoclist(&rc, &s, &a[iOff], nDoclist);
+
+    while( iPgidxOff<n ){
+      int bFirst = (iPgidxOff==szLeaf);     /* True for first term on page */
+      int nByte;                            /* Bytes of data */
+      int iEnd;
+      
+      iPgidxOff += fts5GetVarint32(&a[iPgidxOff], nByte);
+      iPgidxPrev += nByte;
+      iOff = iPgidxPrev;
+
+      if( iPgidxOff<n ){
+        fts5GetVarint32(&a[iPgidxOff], nByte);
+        iEnd = iPgidxPrev + nByte;
+      }else{
+        iEnd = szLeaf;
+      }
+
+      if( bFirst==0 ){
+        iOff += fts5GetVarint32(&a[iOff], nByte);
+        term.n = nByte;
+      }
+      iOff += fts5GetVarint32(&a[iOff], nByte);
+      fts5BufferAppendBlob(&rc, &term, nByte, &a[iOff]);
+      iOff += nByte;
+
+      sqlite3Fts5BufferAppendPrintf(
+          &rc, &s, " term=%.*s", term.n, (const char*)term.p
+      );
+      iOff += fts5DecodeDoclist(&rc, &s, &a[iOff], iEnd-iOff);
+    }
+
+    fts5BufferFree(&term);
+  }
+  
+ decode_out:
+  sqlite3_free(a);
+  if( rc==SQLITE_OK ){
+    sqlite3_result_text(pCtx, (const char*)s.p, s.n, SQLITE_TRANSIENT);
+  }else{
+    sqlite3_result_error_code(pCtx, rc);
+  }
+  fts5BufferFree(&s);
+}
+
+/*
+** The implementation of user-defined scalar function fts5_rowid().
+*/
+static void fts5RowidFunction(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args (always 2) */
+  sqlite3_value **apVal           /* Function arguments */
+){
+  const char *zArg;
+  if( nArg==0 ){
+    sqlite3_result_error(pCtx, "should be: fts5_rowid(subject, ....)", -1);
+  }else{
+    zArg = (const char*)sqlite3_value_text(apVal[0]);
+    if( 0==sqlite3_stricmp(zArg, "segment") ){
+      i64 iRowid;
+      int segid, pgno;
+      if( nArg!=3 ){
+        sqlite3_result_error(pCtx, 
+            "should be: fts5_rowid('segment', segid, pgno))", -1
+        );
+      }else{
+        segid = sqlite3_value_int(apVal[1]);
+        pgno = sqlite3_value_int(apVal[2]);
+        iRowid = FTS5_SEGMENT_ROWID(segid, pgno);
+        sqlite3_result_int64(pCtx, iRowid);
+      }
+    }else{
+      sqlite3_result_error(pCtx, 
+        "first arg to fts5_rowid() must be 'segment'" , -1
+      );
+    }
+  }
+}
+
+/*
+** This is called as part of registering the FTS5 module with database
+** connection db. It registers several user-defined scalar functions useful
+** with FTS5.
+**
+** If successful, SQLITE_OK is returned. If an error occurs, some other
+** SQLite error code is returned instead.
+*/
+static int sqlite3Fts5IndexInit(sqlite3 *db){
+  int rc = sqlite3_create_function(
+      db, "fts5_decode", 2, SQLITE_UTF8, 0, fts5DecodeFunction, 0, 0
+  );
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(
+        db, "fts5_decode_none", 2, 
+        SQLITE_UTF8, (void*)db, fts5DecodeFunction, 0, 0
+    );
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(
+        db, "fts5_rowid", -1, SQLITE_UTF8, 0, fts5RowidFunction, 0, 0
+    );
+  }
+  return rc;
+}
+
+
+static int sqlite3Fts5IndexReset(Fts5Index *p){
+  assert( p->pStruct==0 || p->iStructVersion!=0 );
+  if( fts5IndexDataVersion(p)!=p->iStructVersion ){
+    fts5StructureInvalidate(p);
+  }
+  return fts5IndexReturn(p);
+}
+
+/*
+** 2014 Jun 09
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is an SQLite module implementing full-text search.
+*/
+
+
+/* #include "fts5Int.h" */
+
+/*
+** This variable is set to false when running tests for which the on disk
+** structures should not be corrupt. Otherwise, true. If it is false, extra
+** assert() conditions in the fts5 code are activated - conditions that are
+** only true if it is guaranteed that the fts5 database is not corrupt.
+*/
+SQLITE_API int sqlite3_fts5_may_be_corrupt = 1;
+
+
+typedef struct Fts5Auxdata Fts5Auxdata;
+typedef struct Fts5Auxiliary Fts5Auxiliary;
+typedef struct Fts5Cursor Fts5Cursor;
+typedef struct Fts5Sorter Fts5Sorter;
+typedef struct Fts5Table Fts5Table;
+typedef struct Fts5TokenizerModule Fts5TokenizerModule;
+
+/*
+** NOTES ON TRANSACTIONS: 
+**
+** SQLite invokes the following virtual table methods as transactions are 
+** opened and closed by the user:
+**
+**     xBegin():    Start of a new transaction.
+**     xSync():     Initial part of two-phase commit.
+**     xCommit():   Final part of two-phase commit.
+**     xRollback(): Rollback the transaction.
+**
+** Anything that is required as part of a commit that may fail is performed
+** in the xSync() callback. Current versions of SQLite ignore any errors 
+** returned by xCommit().
+**
+** And as sub-transactions are opened/closed:
+**
+**     xSavepoint(int S):  Open savepoint S.
+**     xRelease(int S):    Commit and close savepoint S.
+**     xRollbackTo(int S): Rollback to start of savepoint S.
+**
+** During a write-transaction the fts5_index.c module may cache some data 
+** in-memory. It is flushed to disk whenever xSync(), xRelease() or
+** xSavepoint() is called. And discarded whenever xRollback() or xRollbackTo() 
+** is called.
+**
+** Additionally, if SQLITE_DEBUG is defined, an instance of the following
+** structure is used to record the current transaction state. This information
+** is not required, but it is used in the assert() statements executed by
+** function fts5CheckTransactionState() (see below).
+*/
+struct Fts5TransactionState {
+  int eState;                     /* 0==closed, 1==open, 2==synced */
+  int iSavepoint;                 /* Number of open savepoints (0 -> none) */
+};
+
+/*
+** A single object of this type is allocated when the FTS5 module is 
+** registered with a database handle. It is used to store pointers to
+** all registered FTS5 extensions - tokenizers and auxiliary functions.
+*/
+struct Fts5Global {
+  fts5_api api;                   /* User visible part of object (see fts5.h) */
+  sqlite3 *db;                    /* Associated database connection */ 
+  i64 iNextId;                    /* Used to allocate unique cursor ids */
+  Fts5Auxiliary *pAux;            /* First in list of all aux. functions */
+  Fts5TokenizerModule *pTok;      /* First in list of all tokenizer modules */
+  Fts5TokenizerModule *pDfltTok;  /* Default tokenizer module */
+  Fts5Cursor *pCsr;               /* First in list of all open cursors */
+};
+
+/*
+** Each auxiliary function registered with the FTS5 module is represented
+** by an object of the following type. All such objects are stored as part
+** of the Fts5Global.pAux list.
+*/
+struct Fts5Auxiliary {
+  Fts5Global *pGlobal;            /* Global context for this function */
+  char *zFunc;                    /* Function name (nul-terminated) */
+  void *pUserData;                /* User-data pointer */
+  fts5_extension_function xFunc;  /* Callback function */
+  void (*xDestroy)(void*);        /* Destructor function */
+  Fts5Auxiliary *pNext;           /* Next registered auxiliary function */
+};
+
+/*
+** Each tokenizer module registered with the FTS5 module is represented
+** by an object of the following type. All such objects are stored as part
+** of the Fts5Global.pTok list.
+*/
+struct Fts5TokenizerModule {
+  char *zName;                    /* Name of tokenizer */
+  void *pUserData;                /* User pointer passed to xCreate() */
+  fts5_tokenizer x;               /* Tokenizer functions */
+  void (*xDestroy)(void*);        /* Destructor function */
+  Fts5TokenizerModule *pNext;     /* Next registered tokenizer module */
+};
+
+/*
+** Virtual-table object.
+*/
+struct Fts5Table {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  Fts5Config *pConfig;            /* Virtual table configuration */
+  Fts5Index *pIndex;              /* Full-text index */
+  Fts5Storage *pStorage;          /* Document store */
+  Fts5Global *pGlobal;            /* Global (connection wide) data */
+  Fts5Cursor *pSortCsr;           /* Sort data from this cursor */
+#ifdef SQLITE_DEBUG
+  struct Fts5TransactionState ts;
+#endif
+};
+
+struct Fts5MatchPhrase {
+  Fts5Buffer *pPoslist;           /* Pointer to current poslist */
+  int nTerm;                      /* Size of phrase in terms */
+};
+
+/*
+** pStmt:
+**   SELECT rowid, <fts> FROM <fts> ORDER BY +rank;
+**
+** aIdx[]:
+**   There is one entry in the aIdx[] array for each phrase in the query,
+**   the value of which is the offset within aPoslist[] following the last 
+**   byte of the position list for the corresponding phrase.
+*/
+struct Fts5Sorter {
+  sqlite3_stmt *pStmt;
+  i64 iRowid;                     /* Current rowid */
+  const u8 *aPoslist;             /* Position lists for current row */
+  int nIdx;                       /* Number of entries in aIdx[] */
+  int aIdx[1];                    /* Offsets into aPoslist for current row */
+};
+
+
+/*
+** Virtual-table cursor object.
+**
+** iSpecial:
+**   If this is a 'special' query (refer to function fts5SpecialMatch()), 
+**   then this variable contains the result of the query. 
+**
+** iFirstRowid, iLastRowid:
+**   These variables are only used for FTS5_PLAN_MATCH cursors. Assuming the
+**   cursor iterates in ascending order of rowids, iFirstRowid is the lower
+**   limit of rowids to return, and iLastRowid the upper. In other words, the
+**   WHERE clause in the user's query might have been:
+**
+**       <tbl> MATCH <expr> AND rowid BETWEEN $iFirstRowid AND $iLastRowid
+**
+**   If the cursor iterates in descending order of rowid, iFirstRowid
+**   is the upper limit (i.e. the "first" rowid visited) and iLastRowid
+**   the lower.
+*/
+struct Fts5Cursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  Fts5Cursor *pNext;              /* Next cursor in Fts5Cursor.pCsr list */
+  int *aColumnSize;               /* Values for xColumnSize() */
+  i64 iCsrId;                     /* Cursor id */
+
+  /* Zero from this point onwards on cursor reset */
+  int ePlan;                      /* FTS5_PLAN_XXX value */
+  int bDesc;                      /* True for "ORDER BY rowid DESC" queries */
+  i64 iFirstRowid;                /* Return no rowids earlier than this */
+  i64 iLastRowid;                 /* Return no rowids later than this */
+  sqlite3_stmt *pStmt;            /* Statement used to read %_content */
+  Fts5Expr *pExpr;                /* Expression for MATCH queries */
+  Fts5Sorter *pSorter;            /* Sorter for "ORDER BY rank" queries */
+  int csrflags;                   /* Mask of cursor flags (see below) */
+  i64 iSpecial;                   /* Result of special query */
+
+  /* "rank" function. Populated on demand from vtab.xColumn(). */
+  char *zRank;                    /* Custom rank function */
+  char *zRankArgs;                /* Custom rank function args */
+  Fts5Auxiliary *pRank;           /* Rank callback (or NULL) */
+  int nRankArg;                   /* Number of trailing arguments for rank() */
+  sqlite3_value **apRankArg;      /* Array of trailing arguments */
+  sqlite3_stmt *pRankArgStmt;     /* Origin of objects in apRankArg[] */
+
+  /* Auxiliary data storage */
+  Fts5Auxiliary *pAux;            /* Currently executing extension function */
+  Fts5Auxdata *pAuxdata;          /* First in linked list of saved aux-data */
+
+  /* Cache used by auxiliary functions xInst() and xInstCount() */
+  Fts5PoslistReader *aInstIter;   /* One for each phrase */
+  int nInstAlloc;                 /* Size of aInst[] array (entries / 3) */
+  int nInstCount;                 /* Number of phrase instances */
+  int *aInst;                     /* 3 integers per phrase instance */
+};
+
+/*
+** Bits that make up the "idxNum" parameter passed indirectly by 
+** xBestIndex() to xFilter().
+*/
+#define FTS5_BI_MATCH        0x0001         /* <tbl> MATCH ? */
+#define FTS5_BI_RANK         0x0002         /* rank MATCH ? */
+#define FTS5_BI_ROWID_EQ     0x0004         /* rowid == ? */
+#define FTS5_BI_ROWID_LE     0x0008         /* rowid <= ? */
+#define FTS5_BI_ROWID_GE     0x0010         /* rowid >= ? */
+
+#define FTS5_BI_ORDER_RANK   0x0020
+#define FTS5_BI_ORDER_ROWID  0x0040
+#define FTS5_BI_ORDER_DESC   0x0080
+
+/*
+** Values for Fts5Cursor.csrflags
+*/
+#define FTS5CSR_EOF               0x01
+#define FTS5CSR_REQUIRE_CONTENT   0x02
+#define FTS5CSR_REQUIRE_DOCSIZE   0x04
+#define FTS5CSR_REQUIRE_INST      0x08
+#define FTS5CSR_FREE_ZRANK        0x10
+#define FTS5CSR_REQUIRE_RESEEK    0x20
+#define FTS5CSR_REQUIRE_POSLIST   0x40
+
+#define BitFlagAllTest(x,y) (((x) & (y))==(y))
+#define BitFlagTest(x,y)    (((x) & (y))!=0)
+
+
+/*
+** Macros to Set(), Clear() and Test() cursor flags.
+*/
+#define CsrFlagSet(pCsr, flag)   ((pCsr)->csrflags |= (flag))
+#define CsrFlagClear(pCsr, flag) ((pCsr)->csrflags &= ~(flag))
+#define CsrFlagTest(pCsr, flag)  ((pCsr)->csrflags & (flag))
+
+struct Fts5Auxdata {
+  Fts5Auxiliary *pAux;            /* Extension to which this belongs */
+  void *pPtr;                     /* Pointer value */
+  void(*xDelete)(void*);          /* Destructor */
+  Fts5Auxdata *pNext;             /* Next object in linked list */
+};
+
+#ifdef SQLITE_DEBUG
+#define FTS5_BEGIN      1
+#define FTS5_SYNC       2
+#define FTS5_COMMIT     3
+#define FTS5_ROLLBACK   4
+#define FTS5_SAVEPOINT  5
+#define FTS5_RELEASE    6
+#define FTS5_ROLLBACKTO 7
+static void fts5CheckTransactionState(Fts5Table *p, int op, int iSavepoint){
+  switch( op ){
+    case FTS5_BEGIN:
+      assert( p->ts.eState==0 );
+      p->ts.eState = 1;
+      p->ts.iSavepoint = -1;
+      break;
+
+    case FTS5_SYNC:
+      assert( p->ts.eState==1 );
+      p->ts.eState = 2;
+      break;
+
+    case FTS5_COMMIT:
+      assert( p->ts.eState==2 );
+      p->ts.eState = 0;
+      break;
+
+    case FTS5_ROLLBACK:
+      assert( p->ts.eState==1 || p->ts.eState==2 || p->ts.eState==0 );
+      p->ts.eState = 0;
+      break;
+
+    case FTS5_SAVEPOINT:
+      assert( p->ts.eState==1 );
+      assert( iSavepoint>=0 );
+      assert( iSavepoint>p->ts.iSavepoint );
+      p->ts.iSavepoint = iSavepoint;
+      break;
+      
+    case FTS5_RELEASE:
+      assert( p->ts.eState==1 );
+      assert( iSavepoint>=0 );
+      assert( iSavepoint<=p->ts.iSavepoint );
+      p->ts.iSavepoint = iSavepoint-1;
+      break;
+
+    case FTS5_ROLLBACKTO:
+      assert( p->ts.eState==1 );
+      assert( iSavepoint>=0 );
+      assert( iSavepoint<=p->ts.iSavepoint );
+      p->ts.iSavepoint = iSavepoint;
+      break;
+  }
+}
+#else
+# define fts5CheckTransactionState(x,y,z)
+#endif
+
+/*
+** Return true if pTab is a contentless table.
+*/
+static int fts5IsContentless(Fts5Table *pTab){
+  return pTab->pConfig->eContent==FTS5_CONTENT_NONE;
+}
+
+/*
+** Delete a virtual table handle allocated by fts5InitVtab(). 
+*/
+static void fts5FreeVtab(Fts5Table *pTab){
+  if( pTab ){
+    sqlite3Fts5IndexClose(pTab->pIndex);
+    sqlite3Fts5StorageClose(pTab->pStorage);
+    sqlite3Fts5ConfigFree(pTab->pConfig);
+    sqlite3_free(pTab);
+  }
+}
+
+/*
+** The xDisconnect() virtual table method.
+*/
+static int fts5DisconnectMethod(sqlite3_vtab *pVtab){
+  fts5FreeVtab((Fts5Table*)pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** The xDestroy() virtual table method.
+*/
+static int fts5DestroyMethod(sqlite3_vtab *pVtab){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  int rc = sqlite3Fts5DropAll(pTab->pConfig);
+  if( rc==SQLITE_OK ){
+    fts5FreeVtab((Fts5Table*)pVtab);
+  }
+  return rc;
+}
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the FTS3 virtual table.
+**
+** The argv[] array contains the following:
+**
+**   argv[0]   -> module name  ("fts5")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**   argv[...] -> "column name" and other module argument fields.
+*/
+static int fts5InitVtab(
+  int bCreate,                    /* True for xCreate, false for xConnect */
+  sqlite3 *db,                    /* The SQLite database connection */
+  void *pAux,                     /* Hash table containing tokenizers */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
+  char **pzErr                    /* Write any error message here */
+){
+  Fts5Global *pGlobal = (Fts5Global*)pAux;
+  const char **azConfig = (const char**)argv;
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5Config *pConfig = 0;        /* Results of parsing argc/argv */
+  Fts5Table *pTab = 0;            /* New virtual table object */
+
+  /* Allocate the new vtab object and parse the configuration */
+  pTab = (Fts5Table*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Table));
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5ConfigParse(pGlobal, db, argc, azConfig, &pConfig, pzErr);
+    assert( (rc==SQLITE_OK && *pzErr==0) || pConfig==0 );
+  }
+  if( rc==SQLITE_OK ){
+    pTab->pConfig = pConfig;
+    pTab->pGlobal = pGlobal;
+  }
+
+  /* Open the index sub-system */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexOpen(pConfig, bCreate, &pTab->pIndex, pzErr);
+  }
+
+  /* Open the storage sub-system */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5StorageOpen(
+        pConfig, pTab->pIndex, bCreate, &pTab->pStorage, pzErr
+    );
+  }
+
+  /* Call sqlite3_declare_vtab() */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5ConfigDeclareVtab(pConfig);
+  }
+
+  /* Load the initial configuration */
+  if( rc==SQLITE_OK ){
+    assert( pConfig->pzErrmsg==0 );
+    pConfig->pzErrmsg = pzErr;
+    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
+    sqlite3Fts5IndexRollback(pTab->pIndex);
+    pConfig->pzErrmsg = 0;
+  }
+
+  if( rc!=SQLITE_OK ){
+    fts5FreeVtab(pTab);
+    pTab = 0;
+  }else if( bCreate ){
+    fts5CheckTransactionState(pTab, FTS5_BEGIN, 0);
+  }
+  *ppVTab = (sqlite3_vtab*)pTab;
+  return rc;
+}
+
+/*
+** The xConnect() and xCreate() methods for the virtual table. All the
+** work is done in function fts5InitVtab().
+*/
+static int fts5ConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts5InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);
+}
+static int fts5CreateMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts5InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/*
+** The different query plans.
+*/
+#define FTS5_PLAN_MATCH          1       /* (<tbl> MATCH ?) */
+#define FTS5_PLAN_SOURCE         2       /* A source cursor for SORTED_MATCH */
+#define FTS5_PLAN_SPECIAL        3       /* An internal query */
+#define FTS5_PLAN_SORTED_MATCH   4       /* (<tbl> MATCH ? ORDER BY rank) */
+#define FTS5_PLAN_SCAN           5       /* No usable constraint */
+#define FTS5_PLAN_ROWID          6       /* (rowid = ?) */
+
+/*
+** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support index-info flags. In that case this function is a no-op.
+*/
+static void fts5SetUniqueFlag(sqlite3_index_info *pIdxInfo){
+#if SQLITE_VERSION_NUMBER>=3008012
+#ifndef SQLITE_CORE
+  if( sqlite3_libversion_number()>=3008012 )
+#endif
+  {
+    pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;
+  }
+#endif
+}
+
+/*
+** Implementation of the xBestIndex method for FTS5 tables. Within the 
+** WHERE constraint, it searches for the following:
+**
+**   1. A MATCH constraint against the special column.
+**   2. A MATCH constraint against the "rank" column.
+**   3. An == constraint against the rowid column.
+**   4. A < or <= constraint against the rowid column.
+**   5. A > or >= constraint against the rowid column.
+**
+** Within the ORDER BY, either:
+**
+**   5. ORDER BY rank [ASC|DESC]
+**   6. ORDER BY rowid [ASC|DESC]
+**
+** Costs are assigned as follows:
+**
+**  a) If an unusable MATCH operator is present in the WHERE clause, the
+**     cost is unconditionally set to 1e50 (a really big number).
+**
+**  a) If a MATCH operator is present, the cost depends on the other
+**     constraints also present. As follows:
+**
+**       * No other constraints:         cost=1000.0
+**       * One rowid range constraint:   cost=750.0
+**       * Both rowid range constraints: cost=500.0
+**       * An == rowid constraint:       cost=100.0
+**
+**  b) Otherwise, if there is no MATCH:
+**
+**       * No other constraints:         cost=1000000.0
+**       * One rowid range constraint:   cost=750000.0
+**       * Both rowid range constraints: cost=250000.0
+**       * An == rowid constraint:       cost=10.0
+**
+** Costs are not modified by the ORDER BY clause.
+*/
+static int fts5BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
+  Fts5Table *pTab = (Fts5Table*)pVTab;
+  Fts5Config *pConfig = pTab->pConfig;
+  int idxFlags = 0;               /* Parameter passed through to xFilter() */
+  int bHasMatch;
+  int iNext;
+  int i;
+
+  struct Constraint {
+    int op;                       /* Mask against sqlite3_index_constraint.op */
+    int fts5op;                   /* FTS5 mask for idxFlags */
+    int iCol;                     /* 0==rowid, 1==tbl, 2==rank */
+    int omit;                     /* True to omit this if found */
+    int iConsIndex;               /* Index in pInfo->aConstraint[] */
+  } aConstraint[] = {
+    {SQLITE_INDEX_CONSTRAINT_MATCH|SQLITE_INDEX_CONSTRAINT_EQ, 
+                                    FTS5_BI_MATCH,    1, 1, -1},
+    {SQLITE_INDEX_CONSTRAINT_MATCH|SQLITE_INDEX_CONSTRAINT_EQ, 
+                                    FTS5_BI_RANK,     2, 1, -1},
+    {SQLITE_INDEX_CONSTRAINT_EQ,    FTS5_BI_ROWID_EQ, 0, 0, -1},
+    {SQLITE_INDEX_CONSTRAINT_LT|SQLITE_INDEX_CONSTRAINT_LE, 
+                                    FTS5_BI_ROWID_LE, 0, 0, -1},
+    {SQLITE_INDEX_CONSTRAINT_GT|SQLITE_INDEX_CONSTRAINT_GE, 
+                                    FTS5_BI_ROWID_GE, 0, 0, -1},
+  };
+
+  int aColMap[3];
+  aColMap[0] = -1;
+  aColMap[1] = pConfig->nCol;
+  aColMap[2] = pConfig->nCol+1;
+
+  /* Set idxFlags flags for all WHERE clause terms that will be used. */
+  for(i=0; i<pInfo->nConstraint; i++){
+    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
+    int j;
+    for(j=0; j<ArraySize(aConstraint); j++){
+      struct Constraint *pC = &aConstraint[j];
+      if( p->iColumn==aColMap[pC->iCol] && p->op & pC->op ){
+        if( p->usable ){
+          pC->iConsIndex = i;
+          idxFlags |= pC->fts5op;
+        }else if( j==0 ){
+          /* As there exists an unusable MATCH constraint this is an 
+          ** unusable plan. Set a prohibitively high cost. */
+          pInfo->estimatedCost = 1e50;
+          return SQLITE_OK;
+        }
+      }
+    }
+  }
+
+  /* Set idxFlags flags for the ORDER BY clause */
+  if( pInfo->nOrderBy==1 ){
+    int iSort = pInfo->aOrderBy[0].iColumn;
+    if( iSort==(pConfig->nCol+1) && BitFlagTest(idxFlags, FTS5_BI_MATCH) ){
+      idxFlags |= FTS5_BI_ORDER_RANK;
+    }else if( iSort==-1 ){
+      idxFlags |= FTS5_BI_ORDER_ROWID;
+    }
+    if( BitFlagTest(idxFlags, FTS5_BI_ORDER_RANK|FTS5_BI_ORDER_ROWID) ){
+      pInfo->orderByConsumed = 1;
+      if( pInfo->aOrderBy[0].desc ){
+        idxFlags |= FTS5_BI_ORDER_DESC;
+      }
+    }
+  }
+
+  /* Calculate the estimated cost based on the flags set in idxFlags. */
+  bHasMatch = BitFlagTest(idxFlags, FTS5_BI_MATCH);
+  if( BitFlagTest(idxFlags, FTS5_BI_ROWID_EQ) ){
+    pInfo->estimatedCost = bHasMatch ? 100.0 : 10.0;
+    if( bHasMatch==0 ) fts5SetUniqueFlag(pInfo);
+  }else if( BitFlagAllTest(idxFlags, FTS5_BI_ROWID_LE|FTS5_BI_ROWID_GE) ){
+    pInfo->estimatedCost = bHasMatch ? 500.0 : 250000.0;
+  }else if( BitFlagTest(idxFlags, FTS5_BI_ROWID_LE|FTS5_BI_ROWID_GE) ){
+    pInfo->estimatedCost = bHasMatch ? 750.0 : 750000.0;
+  }else{
+    pInfo->estimatedCost = bHasMatch ? 1000.0 : 1000000.0;
+  }
+
+  /* Assign argvIndex values to each constraint in use. */
+  iNext = 1;
+  for(i=0; i<ArraySize(aConstraint); i++){
+    struct Constraint *pC = &aConstraint[i];
+    if( pC->iConsIndex>=0 ){
+      pInfo->aConstraintUsage[pC->iConsIndex].argvIndex = iNext++;
+      pInfo->aConstraintUsage[pC->iConsIndex].omit = (unsigned char)pC->omit;
+    }
+  }
+
+  pInfo->idxNum = idxFlags;
+  return SQLITE_OK;
+}
+
+static int fts5NewTransaction(Fts5Table *pTab){
+  Fts5Cursor *pCsr;
+  for(pCsr=pTab->pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){
+    if( pCsr->base.pVtab==(sqlite3_vtab*)pTab ) return SQLITE_OK;
+  }
+  return sqlite3Fts5StorageReset(pTab->pStorage);
+}
+
+/*
+** Implementation of xOpen method.
+*/
+static int fts5OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts5Table *pTab = (Fts5Table*)pVTab;
+  Fts5Config *pConfig = pTab->pConfig;
+  Fts5Cursor *pCsr = 0;           /* New cursor object */
+  int nByte;                      /* Bytes of space to allocate */
+  int rc;                         /* Return code */
+
+  rc = fts5NewTransaction(pTab);
+  if( rc==SQLITE_OK ){
+    nByte = sizeof(Fts5Cursor) + pConfig->nCol * sizeof(int);
+    pCsr = (Fts5Cursor*)sqlite3_malloc(nByte);
+    if( pCsr ){
+      Fts5Global *pGlobal = pTab->pGlobal;
+      memset(pCsr, 0, nByte);
+      pCsr->aColumnSize = (int*)&pCsr[1];
+      pCsr->pNext = pGlobal->pCsr;
+      pGlobal->pCsr = pCsr;
+      pCsr->iCsrId = ++pGlobal->iNextId;
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  *ppCsr = (sqlite3_vtab_cursor*)pCsr;
+  return rc;
+}
+
+static int fts5StmtType(Fts5Cursor *pCsr){
+  if( pCsr->ePlan==FTS5_PLAN_SCAN ){
+    return (pCsr->bDesc) ? FTS5_STMT_SCAN_DESC : FTS5_STMT_SCAN_ASC;
+  }
+  return FTS5_STMT_LOOKUP;
+}
+
+/*
+** This function is called after the cursor passed as the only argument
+** is moved to point at a different row. It clears all cached data 
+** specific to the previous row stored by the cursor object.
+*/
+static void fts5CsrNewrow(Fts5Cursor *pCsr){
+  CsrFlagSet(pCsr, 
+      FTS5CSR_REQUIRE_CONTENT 
+    | FTS5CSR_REQUIRE_DOCSIZE 
+    | FTS5CSR_REQUIRE_INST 
+    | FTS5CSR_REQUIRE_POSLIST 
+  );
+}
+
+static void fts5FreeCursorComponents(Fts5Cursor *pCsr){
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  Fts5Auxdata *pData;
+  Fts5Auxdata *pNext;
+
+  sqlite3_free(pCsr->aInstIter);
+  sqlite3_free(pCsr->aInst);
+  if( pCsr->pStmt ){
+    int eStmt = fts5StmtType(pCsr);
+    sqlite3Fts5StorageStmtRelease(pTab->pStorage, eStmt, pCsr->pStmt);
+  }
+  if( pCsr->pSorter ){
+    Fts5Sorter *pSorter = pCsr->pSorter;
+    sqlite3_finalize(pSorter->pStmt);
+    sqlite3_free(pSorter);
+  }
+
+  if( pCsr->ePlan!=FTS5_PLAN_SOURCE ){
+    sqlite3Fts5ExprFree(pCsr->pExpr);
+  }
+
+  for(pData=pCsr->pAuxdata; pData; pData=pNext){
+    pNext = pData->pNext;
+    if( pData->xDelete ) pData->xDelete(pData->pPtr);
+    sqlite3_free(pData);
+  }
+
+  sqlite3_finalize(pCsr->pRankArgStmt);
+  sqlite3_free(pCsr->apRankArg);
+
+  if( CsrFlagTest(pCsr, FTS5CSR_FREE_ZRANK) ){
+    sqlite3_free(pCsr->zRank);
+    sqlite3_free(pCsr->zRankArgs);
+  }
+
+  memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan - (u8*)pCsr));
+}
+
+
+/*
+** Close the cursor.  For additional information see the documentation
+** on the xClose method of the virtual table interface.
+*/
+static int fts5CloseMethod(sqlite3_vtab_cursor *pCursor){
+  if( pCursor ){
+    Fts5Table *pTab = (Fts5Table*)(pCursor->pVtab);
+    Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+    Fts5Cursor **pp;
+
+    fts5FreeCursorComponents(pCsr);
+    /* Remove the cursor from the Fts5Global.pCsr list */
+    for(pp=&pTab->pGlobal->pCsr; (*pp)!=pCsr; pp=&(*pp)->pNext);
+    *pp = pCsr->pNext;
+
+    sqlite3_free(pCsr);
+  }
+  return SQLITE_OK;
+}
+
+static int fts5SorterNext(Fts5Cursor *pCsr){
+  Fts5Sorter *pSorter = pCsr->pSorter;
+  int rc;
+
+  rc = sqlite3_step(pSorter->pStmt);
+  if( rc==SQLITE_DONE ){
+    rc = SQLITE_OK;
+    CsrFlagSet(pCsr, FTS5CSR_EOF);
+  }else if( rc==SQLITE_ROW ){
+    const u8 *a;
+    const u8 *aBlob;
+    int nBlob;
+    int i;
+    int iOff = 0;
+    rc = SQLITE_OK;
+
+    pSorter->iRowid = sqlite3_column_int64(pSorter->pStmt, 0);
+    nBlob = sqlite3_column_bytes(pSorter->pStmt, 1);
+    aBlob = a = sqlite3_column_blob(pSorter->pStmt, 1);
+
+    /* nBlob==0 in detail=none mode. */
+    if( nBlob>0 ){
+      for(i=0; i<(pSorter->nIdx-1); i++){
+        int iVal;
+        a += fts5GetVarint32(a, iVal);
+        iOff += iVal;
+        pSorter->aIdx[i] = iOff;
+      }
+      pSorter->aIdx[i] = &aBlob[nBlob] - a;
+      pSorter->aPoslist = a;
+    }
+
+    fts5CsrNewrow(pCsr);
+  }
+
+  return rc;
+}
+
+
+/*
+** Set the FTS5CSR_REQUIRE_RESEEK flag on all FTS5_PLAN_MATCH cursors 
+** open on table pTab.
+*/
+static void fts5TripCursors(Fts5Table *pTab){
+  Fts5Cursor *pCsr;
+  for(pCsr=pTab->pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){
+    if( pCsr->ePlan==FTS5_PLAN_MATCH
+     && pCsr->base.pVtab==(sqlite3_vtab*)pTab 
+    ){
+      CsrFlagSet(pCsr, FTS5CSR_REQUIRE_RESEEK);
+    }
+  }
+}
+
+/*
+** If the REQUIRE_RESEEK flag is set on the cursor passed as the first
+** argument, close and reopen all Fts5IndexIter iterators that the cursor 
+** is using. Then attempt to move the cursor to a rowid equal to or laster
+** (in the cursors sort order - ASC or DESC) than the current rowid. 
+**
+** If the new rowid is not equal to the old, set output parameter *pbSkip
+** to 1 before returning. Otherwise, leave it unchanged.
+**
+** Return SQLITE_OK if successful or if no reseek was required, or an 
+** error code if an error occurred.
+*/
+static int fts5CursorReseek(Fts5Cursor *pCsr, int *pbSkip){
+  int rc = SQLITE_OK;
+  assert( *pbSkip==0 );
+  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_RESEEK) ){
+    Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+    int bDesc = pCsr->bDesc;
+    i64 iRowid = sqlite3Fts5ExprRowid(pCsr->pExpr);
+
+    rc = sqlite3Fts5ExprFirst(pCsr->pExpr, pTab->pIndex, iRowid, bDesc);
+    if( rc==SQLITE_OK &&  iRowid!=sqlite3Fts5ExprRowid(pCsr->pExpr) ){
+      *pbSkip = 1;
+    }
+
+    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_RESEEK);
+    fts5CsrNewrow(pCsr);
+    if( sqlite3Fts5ExprEof(pCsr->pExpr) ){
+      CsrFlagSet(pCsr, FTS5CSR_EOF);
+      *pbSkip = 1;
+    }
+  }
+  return rc;
+}
+
+
+/*
+** Advance the cursor to the next row in the table that matches the 
+** search criteria.
+**
+** Return SQLITE_OK if nothing goes wrong.  SQLITE_OK is returned
+** even if we reach end-of-file.  The fts5EofMethod() will be called
+** subsequently to determine whether or not an EOF was hit.
+*/
+static int fts5NextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+  int rc;
+
+  assert( (pCsr->ePlan<3)==
+          (pCsr->ePlan==FTS5_PLAN_MATCH || pCsr->ePlan==FTS5_PLAN_SOURCE) 
+  );
+  assert( !CsrFlagTest(pCsr, FTS5CSR_EOF) );
+
+  if( pCsr->ePlan<3 ){
+    int bSkip = 0;
+    if( (rc = fts5CursorReseek(pCsr, &bSkip)) || bSkip ) return rc;
+    rc = sqlite3Fts5ExprNext(pCsr->pExpr, pCsr->iLastRowid);
+    CsrFlagSet(pCsr, sqlite3Fts5ExprEof(pCsr->pExpr));
+    fts5CsrNewrow(pCsr);
+  }else{
+    switch( pCsr->ePlan ){
+      case FTS5_PLAN_SPECIAL: {
+        CsrFlagSet(pCsr, FTS5CSR_EOF);
+        rc = SQLITE_OK;
+        break;
+      }
+  
+      case FTS5_PLAN_SORTED_MATCH: {
+        rc = fts5SorterNext(pCsr);
+        break;
+      }
+  
+      default:
+        rc = sqlite3_step(pCsr->pStmt);
+        if( rc!=SQLITE_ROW ){
+          CsrFlagSet(pCsr, FTS5CSR_EOF);
+          rc = sqlite3_reset(pCsr->pStmt);
+        }else{
+          rc = SQLITE_OK;
+        }
+        break;
+    }
+  }
+  
+  return rc;
+}
+
+
+static int fts5PrepareStatement(
+  sqlite3_stmt **ppStmt,
+  Fts5Config *pConfig, 
+  const char *zFmt,
+  ...
+){
+  sqlite3_stmt *pRet = 0;
+  int rc;
+  char *zSql;
+  va_list ap;
+
+  va_start(ap, zFmt);
+  zSql = sqlite3_vmprintf(zFmt, ap);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM; 
+  }else{
+    rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &pRet, 0);
+    if( rc!=SQLITE_OK ){
+      *pConfig->pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(pConfig->db));
+    }
+    sqlite3_free(zSql);
+  }
+
+  va_end(ap);
+  *ppStmt = pRet;
+  return rc;
+} 
+
+static int fts5CursorFirstSorted(Fts5Table *pTab, Fts5Cursor *pCsr, int bDesc){
+  Fts5Config *pConfig = pTab->pConfig;
+  Fts5Sorter *pSorter;
+  int nPhrase;
+  int nByte;
+  int rc;
+  const char *zRank = pCsr->zRank;
+  const char *zRankArgs = pCsr->zRankArgs;
+  
+  nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
+  nByte = sizeof(Fts5Sorter) + sizeof(int) * (nPhrase-1);
+  pSorter = (Fts5Sorter*)sqlite3_malloc(nByte);
+  if( pSorter==0 ) return SQLITE_NOMEM;
+  memset(pSorter, 0, nByte);
+  pSorter->nIdx = nPhrase;
+
+  /* TODO: It would be better to have some system for reusing statement
+  ** handles here, rather than preparing a new one for each query. But that
+  ** is not possible as SQLite reference counts the virtual table objects.
+  ** And since the statement required here reads from this very virtual 
+  ** table, saving it creates a circular reference.
+  **
+  ** If SQLite a built-in statement cache, this wouldn't be a problem. */
+  rc = fts5PrepareStatement(&pSorter->pStmt, pConfig,
+      "SELECT rowid, rank FROM %Q.%Q ORDER BY %s(%s%s%s) %s",
+      pConfig->zDb, pConfig->zName, zRank, pConfig->zName,
+      (zRankArgs ? ", " : ""),
+      (zRankArgs ? zRankArgs : ""),
+      bDesc ? "DESC" : "ASC"
+  );
+
+  pCsr->pSorter = pSorter;
+  if( rc==SQLITE_OK ){
+    assert( pTab->pSortCsr==0 );
+    pTab->pSortCsr = pCsr;
+    rc = fts5SorterNext(pCsr);
+    pTab->pSortCsr = 0;
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_finalize(pSorter->pStmt);
+    sqlite3_free(pSorter);
+    pCsr->pSorter = 0;
+  }
+
+  return rc;
+}
+
+static int fts5CursorFirst(Fts5Table *pTab, Fts5Cursor *pCsr, int bDesc){
+  int rc;
+  Fts5Expr *pExpr = pCsr->pExpr;
+  rc = sqlite3Fts5ExprFirst(pExpr, pTab->pIndex, pCsr->iFirstRowid, bDesc);
+  if( sqlite3Fts5ExprEof(pExpr) ){
+    CsrFlagSet(pCsr, FTS5CSR_EOF);
+  }
+  fts5CsrNewrow(pCsr);
+  return rc;
+}
+
+/*
+** Process a "special" query. A special query is identified as one with a
+** MATCH expression that begins with a '*' character. The remainder of
+** the text passed to the MATCH operator are used as  the special query
+** parameters.
+*/
+static int fts5SpecialMatch(
+  Fts5Table *pTab, 
+  Fts5Cursor *pCsr, 
+  const char *zQuery
+){
+  int rc = SQLITE_OK;             /* Return code */
+  const char *z = zQuery;         /* Special query text */
+  int n;                          /* Number of bytes in text at z */
+
+  while( z[0]==' ' ) z++;
+  for(n=0; z[n] && z[n]!=' '; n++);
+
+  assert( pTab->base.zErrMsg==0 );
+  pCsr->ePlan = FTS5_PLAN_SPECIAL;
+
+  if( 0==sqlite3_strnicmp("reads", z, n) ){
+    pCsr->iSpecial = sqlite3Fts5IndexReads(pTab->pIndex);
+  }
+  else if( 0==sqlite3_strnicmp("id", z, n) ){
+    pCsr->iSpecial = pCsr->iCsrId;
+  }
+  else{
+    /* An unrecognized directive. Return an error message. */
+    pTab->base.zErrMsg = sqlite3_mprintf("unknown special query: %.*s", n, z);
+    rc = SQLITE_ERROR;
+  }
+
+  return rc;
+}
+
+/*
+** Search for an auxiliary function named zName that can be used with table
+** pTab. If one is found, return a pointer to the corresponding Fts5Auxiliary
+** structure. Otherwise, if no such function exists, return NULL.
+*/
+static Fts5Auxiliary *fts5FindAuxiliary(Fts5Table *pTab, const char *zName){
+  Fts5Auxiliary *pAux;
+
+  for(pAux=pTab->pGlobal->pAux; pAux; pAux=pAux->pNext){
+    if( sqlite3_stricmp(zName, pAux->zFunc)==0 ) return pAux;
+  }
+
+  /* No function of the specified name was found. Return 0. */
+  return 0;
+}
+
+
+static int fts5FindRankFunction(Fts5Cursor *pCsr){
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  Fts5Config *pConfig = pTab->pConfig;
+  int rc = SQLITE_OK;
+  Fts5Auxiliary *pAux = 0;
+  const char *zRank = pCsr->zRank;
+  const char *zRankArgs = pCsr->zRankArgs;
+
+  if( zRankArgs ){
+    char *zSql = sqlite3Fts5Mprintf(&rc, "SELECT %s", zRankArgs);
+    if( zSql ){
+      sqlite3_stmt *pStmt = 0;
+      rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &pStmt, 0);
+      sqlite3_free(zSql);
+      assert( rc==SQLITE_OK || pCsr->pRankArgStmt==0 );
+      if( rc==SQLITE_OK ){
+        if( SQLITE_ROW==sqlite3_step(pStmt) ){
+          int nByte;
+          pCsr->nRankArg = sqlite3_column_count(pStmt);
+          nByte = sizeof(sqlite3_value*)*pCsr->nRankArg;
+          pCsr->apRankArg = (sqlite3_value**)sqlite3Fts5MallocZero(&rc, nByte);
+          if( rc==SQLITE_OK ){
+            int i;
+            for(i=0; i<pCsr->nRankArg; i++){
+              pCsr->apRankArg[i] = sqlite3_column_value(pStmt, i);
+            }
+          }
+          pCsr->pRankArgStmt = pStmt;
+        }else{
+          rc = sqlite3_finalize(pStmt);
+          assert( rc!=SQLITE_OK );
+        }
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    pAux = fts5FindAuxiliary(pTab, zRank);
+    if( pAux==0 ){
+      assert( pTab->base.zErrMsg==0 );
+      pTab->base.zErrMsg = sqlite3_mprintf("no such function: %s", zRank);
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  pCsr->pRank = pAux;
+  return rc;
+}
+
+
+static int fts5CursorParseRank(
+  Fts5Config *pConfig,
+  Fts5Cursor *pCsr, 
+  sqlite3_value *pRank
+){
+  int rc = SQLITE_OK;
+  if( pRank ){
+    const char *z = (const char*)sqlite3_value_text(pRank);
+    char *zRank = 0;
+    char *zRankArgs = 0;
+
+    if( z==0 ){
+      if( sqlite3_value_type(pRank)==SQLITE_NULL ) rc = SQLITE_ERROR;
+    }else{
+      rc = sqlite3Fts5ConfigParseRank(z, &zRank, &zRankArgs);
+    }
+    if( rc==SQLITE_OK ){
+      pCsr->zRank = zRank;
+      pCsr->zRankArgs = zRankArgs;
+      CsrFlagSet(pCsr, FTS5CSR_FREE_ZRANK);
+    }else if( rc==SQLITE_ERROR ){
+      pCsr->base.pVtab->zErrMsg = sqlite3_mprintf(
+          "parse error in rank function: %s", z
+      );
+    }
+  }else{
+    if( pConfig->zRank ){
+      pCsr->zRank = (char*)pConfig->zRank;
+      pCsr->zRankArgs = (char*)pConfig->zRankArgs;
+    }else{
+      pCsr->zRank = (char*)FTS5_DEFAULT_RANK;
+      pCsr->zRankArgs = 0;
+    }
+  }
+  return rc;
+}
+
+static i64 fts5GetRowidLimit(sqlite3_value *pVal, i64 iDefault){
+  if( pVal ){
+    int eType = sqlite3_value_numeric_type(pVal);
+    if( eType==SQLITE_INTEGER ){
+      return sqlite3_value_int64(pVal);
+    }
+  }
+  return iDefault;
+}
+
+/*
+** This is the xFilter interface for the virtual table.  See
+** the virtual table xFilter method documentation for additional
+** information.
+** 
+** There are three possible query strategies:
+**
+**   1. Full-text search using a MATCH operator.
+**   2. A by-rowid lookup.
+**   3. A full-table scan.
+*/
+static int fts5FilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *zUnused,            /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  Fts5Table *pTab = (Fts5Table*)(pCursor->pVtab);
+  Fts5Config *pConfig = pTab->pConfig;
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+  int rc = SQLITE_OK;             /* Error code */
+  int iVal = 0;                   /* Counter for apVal[] */
+  int bDesc;                      /* True if ORDER BY [rank|rowid] DESC */
+  int bOrderByRank;               /* True if ORDER BY rank */
+  sqlite3_value *pMatch = 0;      /* <tbl> MATCH ? expression (or NULL) */
+  sqlite3_value *pRank = 0;       /* rank MATCH ? expression (or NULL) */
+  sqlite3_value *pRowidEq = 0;    /* rowid = ? expression (or NULL) */
+  sqlite3_value *pRowidLe = 0;    /* rowid <= ? expression (or NULL) */
+  sqlite3_value *pRowidGe = 0;    /* rowid >= ? expression (or NULL) */
+  char **pzErrmsg = pConfig->pzErrmsg;
+
+  UNUSED_PARAM(zUnused);
+  UNUSED_PARAM(nVal);
+
+  if( pCsr->ePlan ){
+    fts5FreeCursorComponents(pCsr);
+    memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan-(u8*)pCsr));
+  }
+
+  assert( pCsr->pStmt==0 );
+  assert( pCsr->pExpr==0 );
+  assert( pCsr->csrflags==0 );
+  assert( pCsr->pRank==0 );
+  assert( pCsr->zRank==0 );
+  assert( pCsr->zRankArgs==0 );
+
+  assert( pzErrmsg==0 || pzErrmsg==&pTab->base.zErrMsg );
+  pConfig->pzErrmsg = &pTab->base.zErrMsg;
+
+  /* Decode the arguments passed through to this function.
+  **
+  ** Note: The following set of if(...) statements must be in the same
+  ** order as the corresponding entries in the struct at the top of
+  ** fts5BestIndexMethod().  */
+  if( BitFlagTest(idxNum, FTS5_BI_MATCH) ) pMatch = apVal[iVal++];
+  if( BitFlagTest(idxNum, FTS5_BI_RANK) ) pRank = apVal[iVal++];
+  if( BitFlagTest(idxNum, FTS5_BI_ROWID_EQ) ) pRowidEq = apVal[iVal++];
+  if( BitFlagTest(idxNum, FTS5_BI_ROWID_LE) ) pRowidLe = apVal[iVal++];
+  if( BitFlagTest(idxNum, FTS5_BI_ROWID_GE) ) pRowidGe = apVal[iVal++];
+  assert( iVal==nVal );
+  bOrderByRank = ((idxNum & FTS5_BI_ORDER_RANK) ? 1 : 0);
+  pCsr->bDesc = bDesc = ((idxNum & FTS5_BI_ORDER_DESC) ? 1 : 0);
+
+  /* Set the cursor upper and lower rowid limits. Only some strategies 
+  ** actually use them. This is ok, as the xBestIndex() method leaves the
+  ** sqlite3_index_constraint.omit flag clear for range constraints
+  ** on the rowid field.  */
+  if( pRowidEq ){
+    pRowidLe = pRowidGe = pRowidEq;
+  }
+  if( bDesc ){
+    pCsr->iFirstRowid = fts5GetRowidLimit(pRowidLe, LARGEST_INT64);
+    pCsr->iLastRowid = fts5GetRowidLimit(pRowidGe, SMALLEST_INT64);
+  }else{
+    pCsr->iLastRowid = fts5GetRowidLimit(pRowidLe, LARGEST_INT64);
+    pCsr->iFirstRowid = fts5GetRowidLimit(pRowidGe, SMALLEST_INT64);
+  }
+
+  if( pTab->pSortCsr ){
+    /* If pSortCsr is non-NULL, then this call is being made as part of 
+    ** processing for a "... MATCH <expr> ORDER BY rank" query (ePlan is
+    ** set to FTS5_PLAN_SORTED_MATCH). pSortCsr is the cursor that will
+    ** return results to the user for this query. The current cursor 
+    ** (pCursor) is used to execute the query issued by function 
+    ** fts5CursorFirstSorted() above.  */
+    assert( pRowidEq==0 && pRowidLe==0 && pRowidGe==0 && pRank==0 );
+    assert( nVal==0 && pMatch==0 && bOrderByRank==0 && bDesc==0 );
+    assert( pCsr->iLastRowid==LARGEST_INT64 );
+    assert( pCsr->iFirstRowid==SMALLEST_INT64 );
+    pCsr->ePlan = FTS5_PLAN_SOURCE;
+    pCsr->pExpr = pTab->pSortCsr->pExpr;
+    rc = fts5CursorFirst(pTab, pCsr, bDesc);
+  }else if( pMatch ){
+    const char *zExpr = (const char*)sqlite3_value_text(apVal[0]);
+    if( zExpr==0 ) zExpr = "";
+
+    rc = fts5CursorParseRank(pConfig, pCsr, pRank);
+    if( rc==SQLITE_OK ){
+      if( zExpr[0]=='*' ){
+        /* The user has issued a query of the form "MATCH '*...'". This
+        ** indicates that the MATCH expression is not a full text query,
+        ** but a request for an internal parameter.  */
+        rc = fts5SpecialMatch(pTab, pCsr, &zExpr[1]);
+      }else{
+        char **pzErr = &pTab->base.zErrMsg;
+        rc = sqlite3Fts5ExprNew(pConfig, zExpr, &pCsr->pExpr, pzErr);
+        if( rc==SQLITE_OK ){
+          if( bOrderByRank ){
+            pCsr->ePlan = FTS5_PLAN_SORTED_MATCH;
+            rc = fts5CursorFirstSorted(pTab, pCsr, bDesc);
+          }else{
+            pCsr->ePlan = FTS5_PLAN_MATCH;
+            rc = fts5CursorFirst(pTab, pCsr, bDesc);
+          }
+        }
+      }
+    }
+  }else if( pConfig->zContent==0 ){
+    *pConfig->pzErrmsg = sqlite3_mprintf(
+        "%s: table does not support scanning", pConfig->zName
+    );
+    rc = SQLITE_ERROR;
+  }else{
+    /* This is either a full-table scan (ePlan==FTS5_PLAN_SCAN) or a lookup
+    ** by rowid (ePlan==FTS5_PLAN_ROWID).  */
+    pCsr->ePlan = (pRowidEq ? FTS5_PLAN_ROWID : FTS5_PLAN_SCAN);
+    rc = sqlite3Fts5StorageStmt(
+        pTab->pStorage, fts5StmtType(pCsr), &pCsr->pStmt, &pTab->base.zErrMsg
+    );
+    if( rc==SQLITE_OK ){
+      if( pCsr->ePlan==FTS5_PLAN_ROWID ){
+        sqlite3_bind_value(pCsr->pStmt, 1, apVal[0]);
+      }else{
+        sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iFirstRowid);
+        sqlite3_bind_int64(pCsr->pStmt, 2, pCsr->iLastRowid);
+      }
+      rc = fts5NextMethod(pCursor);
+    }
+  }
+
+  pConfig->pzErrmsg = pzErrmsg;
+  return rc;
+}
+
+/* 
+** This is the xEof method of the virtual table. SQLite calls this 
+** routine to find out if it has reached the end of a result set.
+*/
+static int fts5EofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+  return (CsrFlagTest(pCsr, FTS5CSR_EOF) ? 1 : 0);
+}
+
+/*
+** Return the rowid that the cursor currently points to.
+*/
+static i64 fts5CursorRowid(Fts5Cursor *pCsr){
+  assert( pCsr->ePlan==FTS5_PLAN_MATCH 
+       || pCsr->ePlan==FTS5_PLAN_SORTED_MATCH 
+       || pCsr->ePlan==FTS5_PLAN_SOURCE 
+  );
+  if( pCsr->pSorter ){
+    return pCsr->pSorter->iRowid;
+  }else{
+    return sqlite3Fts5ExprRowid(pCsr->pExpr);
+  }
+}
+
+/* 
+** This is the xRowid method. The SQLite core calls this routine to
+** retrieve the rowid for the current row of the result set. fts5
+** exposes %_content.rowid as the rowid for the virtual table. The
+** rowid should be written to *pRowid.
+*/
+static int fts5RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+  int ePlan = pCsr->ePlan;
+  
+  assert( CsrFlagTest(pCsr, FTS5CSR_EOF)==0 );
+  switch( ePlan ){
+    case FTS5_PLAN_SPECIAL:
+      *pRowid = 0;
+      break;
+
+    case FTS5_PLAN_SOURCE:
+    case FTS5_PLAN_MATCH:
+    case FTS5_PLAN_SORTED_MATCH:
+      *pRowid = fts5CursorRowid(pCsr);
+      break;
+
+    default:
+      *pRowid = sqlite3_column_int64(pCsr->pStmt, 0);
+      break;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** If the cursor requires seeking (bSeekRequired flag is set), seek it.
+** Return SQLITE_OK if no error occurs, or an SQLite error code otherwise.
+**
+** If argument bErrormsg is true and an error occurs, an error message may
+** be left in sqlite3_vtab.zErrMsg.
+*/
+static int fts5SeekCursor(Fts5Cursor *pCsr, int bErrormsg){
+  int rc = SQLITE_OK;
+
+  /* If the cursor does not yet have a statement handle, obtain one now. */ 
+  if( pCsr->pStmt==0 ){
+    Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+    int eStmt = fts5StmtType(pCsr);
+    rc = sqlite3Fts5StorageStmt(
+        pTab->pStorage, eStmt, &pCsr->pStmt, (bErrormsg?&pTab->base.zErrMsg:0)
+    );
+    assert( rc!=SQLITE_OK || pTab->base.zErrMsg==0 );
+    assert( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) );
+  }
+
+  if( rc==SQLITE_OK && CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) ){
+    assert( pCsr->pExpr );
+    sqlite3_reset(pCsr->pStmt);
+    sqlite3_bind_int64(pCsr->pStmt, 1, fts5CursorRowid(pCsr));
+    rc = sqlite3_step(pCsr->pStmt);
+    if( rc==SQLITE_ROW ){
+      rc = SQLITE_OK;
+      CsrFlagClear(pCsr, FTS5CSR_REQUIRE_CONTENT);
+    }else{
+      rc = sqlite3_reset(pCsr->pStmt);
+      if( rc==SQLITE_OK ){
+        rc = FTS5_CORRUPT;
+      }
+    }
+  }
+  return rc;
+}
+
+static void fts5SetVtabError(Fts5Table *p, const char *zFormat, ...){
+  va_list ap;                     /* ... printf arguments */
+  va_start(ap, zFormat);
+  assert( p->base.zErrMsg==0 );
+  p->base.zErrMsg = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+}
+
+/*
+** This function is called to handle an FTS INSERT command. In other words,
+** an INSERT statement of the form:
+**
+**     INSERT INTO fts(fts) VALUES($pCmd)
+**     INSERT INTO fts(fts, rank) VALUES($pCmd, $pVal)
+**
+** Argument pVal is the value assigned to column "fts" by the INSERT 
+** statement. This function returns SQLITE_OK if successful, or an SQLite
+** error code if an error occurs.
+**
+** The commands implemented by this function are documented in the "Special
+** INSERT Directives" section of the documentation. It should be updated if
+** more commands are added to this function.
+*/
+static int fts5SpecialInsert(
+  Fts5Table *pTab,                /* Fts5 table object */
+  const char *zCmd,               /* Text inserted into table-name column */
+  sqlite3_value *pVal             /* Value inserted into rank column */
+){
+  Fts5Config *pConfig = pTab->pConfig;
+  int rc = SQLITE_OK;
+  int bError = 0;
+
+  if( 0==sqlite3_stricmp("delete-all", zCmd) ){
+    if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
+      fts5SetVtabError(pTab, 
+          "'delete-all' may only be used with a "
+          "contentless or external content fts5 table"
+      );
+      rc = SQLITE_ERROR;
+    }else{
+      rc = sqlite3Fts5StorageDeleteAll(pTab->pStorage);
+    }
+  }else if( 0==sqlite3_stricmp("rebuild", zCmd) ){
+    if( pConfig->eContent==FTS5_CONTENT_NONE ){
+      fts5SetVtabError(pTab, 
+          "'rebuild' may not be used with a contentless fts5 table"
+      );
+      rc = SQLITE_ERROR;
+    }else{
+      rc = sqlite3Fts5StorageRebuild(pTab->pStorage);
+    }
+  }else if( 0==sqlite3_stricmp("optimize", zCmd) ){
+    rc = sqlite3Fts5StorageOptimize(pTab->pStorage);
+  }else if( 0==sqlite3_stricmp("merge", zCmd) ){
+    int nMerge = sqlite3_value_int(pVal);
+    rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);
+  }else if( 0==sqlite3_stricmp("integrity-check", zCmd) ){
+    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);
+#ifdef SQLITE_DEBUG
+  }else if( 0==sqlite3_stricmp("prefix-index", zCmd) ){
+    pConfig->bPrefixIndex = sqlite3_value_int(pVal);
+#endif
+  }else{
+    rc = sqlite3Fts5IndexLoadConfig(pTab->pIndex);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts5ConfigSetValue(pTab->pConfig, zCmd, pVal, &bError);
+    }
+    if( rc==SQLITE_OK ){
+      if( bError ){
+        rc = SQLITE_ERROR;
+      }else{
+        rc = sqlite3Fts5StorageConfigValue(pTab->pStorage, zCmd, pVal, 0);
+      }
+    }
+  }
+  return rc;
+}
+
+static int fts5SpecialDelete(
+  Fts5Table *pTab, 
+  sqlite3_value **apVal
+){
+  int rc = SQLITE_OK;
+  int eType1 = sqlite3_value_type(apVal[1]);
+  if( eType1==SQLITE_INTEGER ){
+    sqlite3_int64 iDel = sqlite3_value_int64(apVal[1]);
+    rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, &apVal[2]);
+  }
+  return rc;
+}
+
+static void fts5StorageInsert(
+  int *pRc, 
+  Fts5Table *pTab, 
+  sqlite3_value **apVal, 
+  i64 *piRowid
+){
+  int rc = *pRc;
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5StorageContentInsert(pTab->pStorage, apVal, piRowid);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal, *piRowid);
+  }
+  *pRc = rc;
+}
+
+/* 
+** This function is the implementation of the xUpdate callback used by 
+** FTS3 virtual tables. It is invoked by SQLite each time a row is to be
+** inserted, updated or deleted.
+**
+** A delete specifies a single argument - the rowid of the row to remove.
+** 
+** Update and insert operations pass:
+**
+**   1. The "old" rowid, or NULL.
+**   2. The "new" rowid.
+**   3. Values for each of the nCol matchable columns.
+**   4. Values for the two hidden columns (<tablename> and "rank").
+*/
+static int fts5UpdateMethod(
+  sqlite3_vtab *pVtab,            /* Virtual table handle */
+  int nArg,                       /* Size of argument array */
+  sqlite3_value **apVal,          /* Array of arguments */
+  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
+){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  Fts5Config *pConfig = pTab->pConfig;
+  int eType0;                     /* value_type() of apVal[0] */
+  int rc = SQLITE_OK;             /* Return code */
+
+  /* A transaction must be open when this is called. */
+  assert( pTab->ts.eState==1 );
+
+  assert( pVtab->zErrMsg==0 );
+  assert( nArg==1 || nArg==(2+pConfig->nCol+2) );
+  assert( nArg==1 
+      || sqlite3_value_type(apVal[1])==SQLITE_INTEGER 
+      || sqlite3_value_type(apVal[1])==SQLITE_NULL 
+  );
+  assert( pTab->pConfig->pzErrmsg==0 );
+  pTab->pConfig->pzErrmsg = &pTab->base.zErrMsg;
+
+  /* Put any active cursors into REQUIRE_SEEK state. */
+  fts5TripCursors(pTab);
+
+  eType0 = sqlite3_value_type(apVal[0]);
+  if( eType0==SQLITE_NULL 
+   && sqlite3_value_type(apVal[2+pConfig->nCol])!=SQLITE_NULL 
+  ){
+    /* A "special" INSERT op. These are handled separately. */
+    const char *z = (const char*)sqlite3_value_text(apVal[2+pConfig->nCol]);
+    if( pConfig->eContent!=FTS5_CONTENT_NORMAL 
+      && 0==sqlite3_stricmp("delete", z) 
+    ){
+      rc = fts5SpecialDelete(pTab, apVal);
+    }else{
+      rc = fts5SpecialInsert(pTab, z, apVal[2 + pConfig->nCol + 1]);
+    }
+  }else{
+    /* A regular INSERT, UPDATE or DELETE statement. The trick here is that
+    ** any conflict on the rowid value must be detected before any 
+    ** modifications are made to the database file. There are 4 cases:
+    **
+    **   1) DELETE
+    **   2) UPDATE (rowid not modified)
+    **   3) UPDATE (rowid modified)
+    **   4) INSERT
+    **
+    ** Cases 3 and 4 may violate the rowid constraint.
+    */
+    int eConflict = SQLITE_ABORT;
+    if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
+      eConflict = sqlite3_vtab_on_conflict(pConfig->db);
+    }
+
+    assert( eType0==SQLITE_INTEGER || eType0==SQLITE_NULL );
+    assert( nArg!=1 || eType0==SQLITE_INTEGER );
+
+    /* Filter out attempts to run UPDATE or DELETE on contentless tables.
+    ** This is not suported.  */
+    if( eType0==SQLITE_INTEGER && fts5IsContentless(pTab) ){
+      pTab->base.zErrMsg = sqlite3_mprintf(
+          "cannot %s contentless fts5 table: %s", 
+          (nArg>1 ? "UPDATE" : "DELETE from"), pConfig->zName
+      );
+      rc = SQLITE_ERROR;
+    }
+
+    /* DELETE */
+    else if( nArg==1 ){
+      i64 iDel = sqlite3_value_int64(apVal[0]);  /* Rowid to delete */
+      rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, 0);
+    }
+
+    /* INSERT */
+    else if( eType0!=SQLITE_INTEGER ){     
+      /* If this is a REPLACE, first remove the current entry (if any) */
+      if( eConflict==SQLITE_REPLACE 
+       && sqlite3_value_type(apVal[1])==SQLITE_INTEGER 
+      ){
+        i64 iNew = sqlite3_value_int64(apVal[1]);  /* Rowid to delete */
+        rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0);
+      }
+      fts5StorageInsert(&rc, pTab, apVal, pRowid);
+    }
+
+    /* UPDATE */
+    else{
+      i64 iOld = sqlite3_value_int64(apVal[0]);  /* Old rowid */
+      i64 iNew = sqlite3_value_int64(apVal[1]);  /* New rowid */
+      if( iOld!=iNew ){
+        if( eConflict==SQLITE_REPLACE ){
+          rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);
+          if( rc==SQLITE_OK ){
+            rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0);
+          }
+          fts5StorageInsert(&rc, pTab, apVal, pRowid);
+        }else{
+          rc = sqlite3Fts5StorageContentInsert(pTab->pStorage, apVal, pRowid);
+          if( rc==SQLITE_OK ){
+            rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);
+          }
+          if( rc==SQLITE_OK ){
+            rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal, *pRowid);
+          }
+        }
+      }else{
+        rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);
+        fts5StorageInsert(&rc, pTab, apVal, pRowid);
+      }
+    }
+  }
+
+  pTab->pConfig->pzErrmsg = 0;
+  return rc;
+}
+
+/*
+** Implementation of xSync() method. 
+*/
+static int fts5SyncMethod(sqlite3_vtab *pVtab){
+  int rc;
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  fts5CheckTransactionState(pTab, FTS5_SYNC, 0);
+  pTab->pConfig->pzErrmsg = &pTab->base.zErrMsg;
+  fts5TripCursors(pTab);
+  rc = sqlite3Fts5StorageSync(pTab->pStorage, 1);
+  pTab->pConfig->pzErrmsg = 0;
+  return rc;
+}
+
+/*
+** Implementation of xBegin() method. 
+*/
+static int fts5BeginMethod(sqlite3_vtab *pVtab){
+  fts5CheckTransactionState((Fts5Table*)pVtab, FTS5_BEGIN, 0);
+  fts5NewTransaction((Fts5Table*)pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of xCommit() method. This is a no-op. The contents of
+** the pending-terms hash-table have already been flushed into the database
+** by fts5SyncMethod().
+*/
+static int fts5CommitMethod(sqlite3_vtab *pVtab){
+  UNUSED_PARAM(pVtab);  /* Call below is a no-op for NDEBUG builds */
+  fts5CheckTransactionState((Fts5Table*)pVtab, FTS5_COMMIT, 0);
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of xRollback(). Discard the contents of the pending-terms
+** hash-table. Any changes made to the database are reverted by SQLite.
+*/
+static int fts5RollbackMethod(sqlite3_vtab *pVtab){
+  int rc;
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  fts5CheckTransactionState(pTab, FTS5_ROLLBACK, 0);
+  rc = sqlite3Fts5StorageRollback(pTab->pStorage);
+  return rc;
+}
+
+static int fts5CsrPoslist(Fts5Cursor*, int, const u8**, int*);
+
+static void *fts5ApiUserData(Fts5Context *pCtx){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  return pCsr->pAux->pUserData;
+}
+
+static int fts5ApiColumnCount(Fts5Context *pCtx){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  return ((Fts5Table*)(pCsr->base.pVtab))->pConfig->nCol;
+}
+
+static int fts5ApiColumnTotalSize(
+  Fts5Context *pCtx, 
+  int iCol, 
+  sqlite3_int64 *pnToken
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  return sqlite3Fts5StorageSize(pTab->pStorage, iCol, pnToken);
+}
+
+static int fts5ApiRowCount(Fts5Context *pCtx, i64 *pnRow){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  return sqlite3Fts5StorageRowCount(pTab->pStorage, pnRow);
+}
+
+static int fts5ApiTokenize(
+  Fts5Context *pCtx, 
+  const char *pText, int nText, 
+  void *pUserData,
+  int (*xToken)(void*, int, const char*, int, int, int)
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  return sqlite3Fts5Tokenize(
+      pTab->pConfig, FTS5_TOKENIZE_AUX, pText, nText, pUserData, xToken
+  );
+}
+
+static int fts5ApiPhraseCount(Fts5Context *pCtx){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  return sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
+}
+
+static int fts5ApiPhraseSize(Fts5Context *pCtx, int iPhrase){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  return sqlite3Fts5ExprPhraseSize(pCsr->pExpr, iPhrase);
+}
+
+static int fts5ApiColumnText(
+  Fts5Context *pCtx, 
+  int iCol, 
+  const char **pz, 
+  int *pn
+){
+  int rc = SQLITE_OK;
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  if( fts5IsContentless((Fts5Table*)(pCsr->base.pVtab)) ){
+    *pz = 0;
+    *pn = 0;
+  }else{
+    rc = fts5SeekCursor(pCsr, 0);
+    if( rc==SQLITE_OK ){
+      *pz = (const char*)sqlite3_column_text(pCsr->pStmt, iCol+1);
+      *pn = sqlite3_column_bytes(pCsr->pStmt, iCol+1);
+    }
+  }
+  return rc;
+}
+
+static int fts5CsrPoslist(
+  Fts5Cursor *pCsr, 
+  int iPhrase, 
+  const u8 **pa,
+  int *pn
+){
+  Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;
+  int rc = SQLITE_OK;
+  int bLive = (pCsr->pSorter==0);
+
+  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_POSLIST) ){
+
+    if( pConfig->eDetail!=FTS5_DETAIL_FULL ){
+      Fts5PoslistPopulator *aPopulator;
+      int i;
+      aPopulator = sqlite3Fts5ExprClearPoslists(pCsr->pExpr, bLive);
+      if( aPopulator==0 ) rc = SQLITE_NOMEM;
+      for(i=0; i<pConfig->nCol && rc==SQLITE_OK; i++){
+        int n; const char *z;
+        rc = fts5ApiColumnText((Fts5Context*)pCsr, i, &z, &n);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3Fts5ExprPopulatePoslists(
+              pConfig, pCsr->pExpr, aPopulator, i, z, n
+          );
+        }
+      }
+      sqlite3_free(aPopulator);
+
+      if( pCsr->pSorter ){
+        sqlite3Fts5ExprCheckPoslists(pCsr->pExpr, pCsr->pSorter->iRowid);
+      }
+    }
+    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_POSLIST);
+  }
+
+  if( pCsr->pSorter && pConfig->eDetail==FTS5_DETAIL_FULL ){
+    Fts5Sorter *pSorter = pCsr->pSorter;
+    int i1 = (iPhrase==0 ? 0 : pSorter->aIdx[iPhrase-1]);
+    *pn = pSorter->aIdx[iPhrase] - i1;
+    *pa = &pSorter->aPoslist[i1];
+  }else{
+    *pn = sqlite3Fts5ExprPoslist(pCsr->pExpr, iPhrase, pa);
+  }
+
+  return rc;
+}
+
+/*
+** Ensure that the Fts5Cursor.nInstCount and aInst[] variables are populated
+** correctly for the current view. Return SQLITE_OK if successful, or an
+** SQLite error code otherwise.
+*/
+static int fts5CacheInstArray(Fts5Cursor *pCsr){
+  int rc = SQLITE_OK;
+  Fts5PoslistReader *aIter;       /* One iterator for each phrase */
+  int nIter;                      /* Number of iterators/phrases */
+  
+  nIter = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
+  if( pCsr->aInstIter==0 ){
+    int nByte = sizeof(Fts5PoslistReader) * nIter;
+    pCsr->aInstIter = (Fts5PoslistReader*)sqlite3Fts5MallocZero(&rc, nByte);
+  }
+  aIter = pCsr->aInstIter;
+
+  if( aIter ){
+    int nInst = 0;                /* Number instances seen so far */
+    int i;
+
+    /* Initialize all iterators */
+    for(i=0; i<nIter && rc==SQLITE_OK; i++){
+      const u8 *a;
+      int n; 
+      rc = fts5CsrPoslist(pCsr, i, &a, &n);
+      if( rc==SQLITE_OK ){
+        sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);
+      }
+    }
+
+    if( rc==SQLITE_OK ){
+      while( 1 ){
+        int *aInst;
+        int iBest = -1;
+        for(i=0; i<nIter; i++){
+          if( (aIter[i].bEof==0) 
+              && (iBest<0 || aIter[i].iPos<aIter[iBest].iPos) 
+            ){
+            iBest = i;
+          }
+        }
+        if( iBest<0 ) break;
+
+        nInst++;
+        if( nInst>=pCsr->nInstAlloc ){
+          pCsr->nInstAlloc = pCsr->nInstAlloc ? pCsr->nInstAlloc*2 : 32;
+          aInst = (int*)sqlite3_realloc(
+              pCsr->aInst, pCsr->nInstAlloc*sizeof(int)*3
+              );
+          if( aInst ){
+            pCsr->aInst = aInst;
+          }else{
+            rc = SQLITE_NOMEM;
+            break;
+          }
+        }
+
+        aInst = &pCsr->aInst[3 * (nInst-1)];
+        aInst[0] = iBest;
+        aInst[1] = FTS5_POS2COLUMN(aIter[iBest].iPos);
+        aInst[2] = FTS5_POS2OFFSET(aIter[iBest].iPos);
+        sqlite3Fts5PoslistReaderNext(&aIter[iBest]);
+      }
+    }
+
+    pCsr->nInstCount = nInst;
+    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_INST);
+  }
+  return rc;
+}
+
+static int fts5ApiInstCount(Fts5Context *pCtx, int *pnInst){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  int rc = SQLITE_OK;
+  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_INST)==0 
+   || SQLITE_OK==(rc = fts5CacheInstArray(pCsr)) ){
+    *pnInst = pCsr->nInstCount;
+  }
+  return rc;
+}
+
+static int fts5ApiInst(
+  Fts5Context *pCtx, 
+  int iIdx, 
+  int *piPhrase, 
+  int *piCol, 
+  int *piOff
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  int rc = SQLITE_OK;
+  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_INST)==0 
+   || SQLITE_OK==(rc = fts5CacheInstArray(pCsr)) 
+  ){
+    if( iIdx<0 || iIdx>=pCsr->nInstCount ){
+      rc = SQLITE_RANGE;
+#if 0
+    }else if( fts5IsOffsetless((Fts5Table*)pCsr->base.pVtab) ){
+      *piPhrase = pCsr->aInst[iIdx*3];
+      *piCol = pCsr->aInst[iIdx*3 + 2];
+      *piOff = -1;
+#endif
+    }else{
+      *piPhrase = pCsr->aInst[iIdx*3];
+      *piCol = pCsr->aInst[iIdx*3 + 1];
+      *piOff = pCsr->aInst[iIdx*3 + 2];
+    }
+  }
+  return rc;
+}
+
+static sqlite3_int64 fts5ApiRowid(Fts5Context *pCtx){
+  return fts5CursorRowid((Fts5Cursor*)pCtx);
+}
+
+static int fts5ColumnSizeCb(
+  void *pContext,                 /* Pointer to int */
+  int tflags,
+  const char *pUnused,            /* Buffer containing token */
+  int nUnused,                    /* Size of token in bytes */
+  int iUnused1,                   /* Start offset of token */
+  int iUnused2                    /* End offset of token */
+){
+  int *pCnt = (int*)pContext;
+  UNUSED_PARAM2(pUnused, nUnused);
+  UNUSED_PARAM2(iUnused1, iUnused2);
+  if( (tflags & FTS5_TOKEN_COLOCATED)==0 ){
+    (*pCnt)++;
+  }
+  return SQLITE_OK;
+}
+
+static int fts5ApiColumnSize(Fts5Context *pCtx, int iCol, int *pnToken){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  Fts5Config *pConfig = pTab->pConfig;
+  int rc = SQLITE_OK;
+
+  if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_DOCSIZE) ){
+    if( pConfig->bColumnsize ){
+      i64 iRowid = fts5CursorRowid(pCsr);
+      rc = sqlite3Fts5StorageDocsize(pTab->pStorage, iRowid, pCsr->aColumnSize);
+    }else if( pConfig->zContent==0 ){
+      int i;
+      for(i=0; i<pConfig->nCol; i++){
+        if( pConfig->abUnindexed[i]==0 ){
+          pCsr->aColumnSize[i] = -1;
+        }
+      }
+    }else{
+      int i;
+      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
+        if( pConfig->abUnindexed[i]==0 ){
+          const char *z; int n;
+          void *p = (void*)(&pCsr->aColumnSize[i]);
+          pCsr->aColumnSize[i] = 0;
+          rc = fts5ApiColumnText(pCtx, i, &z, &n);
+          if( rc==SQLITE_OK ){
+            rc = sqlite3Fts5Tokenize(
+                pConfig, FTS5_TOKENIZE_AUX, z, n, p, fts5ColumnSizeCb
+            );
+          }
+        }
+      }
+    }
+    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_DOCSIZE);
+  }
+  if( iCol<0 ){
+    int i;
+    *pnToken = 0;
+    for(i=0; i<pConfig->nCol; i++){
+      *pnToken += pCsr->aColumnSize[i];
+    }
+  }else if( iCol<pConfig->nCol ){
+    *pnToken = pCsr->aColumnSize[iCol];
+  }else{
+    *pnToken = 0;
+    rc = SQLITE_RANGE;
+  }
+  return rc;
+}
+
+/*
+** Implementation of the xSetAuxdata() method.
+*/
+static int fts5ApiSetAuxdata(
+  Fts5Context *pCtx,              /* Fts5 context */
+  void *pPtr,                     /* Pointer to save as auxdata */
+  void(*xDelete)(void*)           /* Destructor for pPtr (or NULL) */
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Auxdata *pData;
+
+  /* Search through the cursors list of Fts5Auxdata objects for one that
+  ** corresponds to the currently executing auxiliary function.  */
+  for(pData=pCsr->pAuxdata; pData; pData=pData->pNext){
+    if( pData->pAux==pCsr->pAux ) break;
+  }
+
+  if( pData ){
+    if( pData->xDelete ){
+      pData->xDelete(pData->pPtr);
+    }
+  }else{
+    int rc = SQLITE_OK;
+    pData = (Fts5Auxdata*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Auxdata));
+    if( pData==0 ){
+      if( xDelete ) xDelete(pPtr);
+      return rc;
+    }
+    pData->pAux = pCsr->pAux;
+    pData->pNext = pCsr->pAuxdata;
+    pCsr->pAuxdata = pData;
+  }
+
+  pData->xDelete = xDelete;
+  pData->pPtr = pPtr;
+  return SQLITE_OK;
+}
+
+static void *fts5ApiGetAuxdata(Fts5Context *pCtx, int bClear){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Auxdata *pData;
+  void *pRet = 0;
+
+  for(pData=pCsr->pAuxdata; pData; pData=pData->pNext){
+    if( pData->pAux==pCsr->pAux ) break;
+  }
+
+  if( pData ){
+    pRet = pData->pPtr;
+    if( bClear ){
+      pData->pPtr = 0;
+      pData->xDelete = 0;
+    }
+  }
+
+  return pRet;
+}
+
+static void fts5ApiPhraseNext(
+  Fts5Context *pUnused, 
+  Fts5PhraseIter *pIter, 
+  int *piCol, int *piOff
+){
+  UNUSED_PARAM(pUnused);
+  if( pIter->a>=pIter->b ){
+    *piCol = -1;
+    *piOff = -1;
+  }else{
+    int iVal;
+    pIter->a += fts5GetVarint32(pIter->a, iVal);
+    if( iVal==1 ){
+      pIter->a += fts5GetVarint32(pIter->a, iVal);
+      *piCol = iVal;
+      *piOff = 0;
+      pIter->a += fts5GetVarint32(pIter->a, iVal);
+    }
+    *piOff += (iVal-2);
+  }
+}
+
+static int fts5ApiPhraseFirst(
+  Fts5Context *pCtx, 
+  int iPhrase, 
+  Fts5PhraseIter *pIter, 
+  int *piCol, int *piOff
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  int n;
+  int rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);
+  if( rc==SQLITE_OK ){
+    pIter->b = &pIter->a[n];
+    *piCol = 0;
+    *piOff = 0;
+    fts5ApiPhraseNext(pCtx, pIter, piCol, piOff);
+  }
+  return rc;
+}
+
+static void fts5ApiPhraseNextColumn(
+  Fts5Context *pCtx, 
+  Fts5PhraseIter *pIter, 
+  int *piCol
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;
+
+  if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+    if( pIter->a>=pIter->b ){
+      *piCol = -1;
+    }else{
+      int iIncr;
+      pIter->a += fts5GetVarint32(&pIter->a[0], iIncr);
+      *piCol += (iIncr-2);
+    }
+  }else{
+    while( 1 ){
+      int dummy;
+      if( pIter->a>=pIter->b ){
+        *piCol = -1;
+        return;
+      }
+      if( pIter->a[0]==0x01 ) break;
+      pIter->a += fts5GetVarint32(pIter->a, dummy);
+    }
+    pIter->a += 1 + fts5GetVarint32(&pIter->a[1], *piCol);
+  }
+}
+
+static int fts5ApiPhraseFirstColumn(
+  Fts5Context *pCtx, 
+  int iPhrase, 
+  Fts5PhraseIter *pIter, 
+  int *piCol
+){
+  int rc = SQLITE_OK;
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;
+
+  if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+    Fts5Sorter *pSorter = pCsr->pSorter;
+    int n;
+    if( pSorter ){
+      int i1 = (iPhrase==0 ? 0 : pSorter->aIdx[iPhrase-1]);
+      n = pSorter->aIdx[iPhrase] - i1;
+      pIter->a = &pSorter->aPoslist[i1];
+    }else{
+      rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, iPhrase, &pIter->a, &n);
+    }
+    if( rc==SQLITE_OK ){
+      pIter->b = &pIter->a[n];
+      *piCol = 0;
+      fts5ApiPhraseNextColumn(pCtx, pIter, piCol);
+    }
+  }else{
+    int n;
+    rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);
+    if( rc==SQLITE_OK ){
+      pIter->b = &pIter->a[n];
+      if( n<=0 ){
+        *piCol = -1;
+      }else if( pIter->a[0]==0x01 ){
+        pIter->a += 1 + fts5GetVarint32(&pIter->a[1], *piCol);
+      }else{
+        *piCol = 0;
+      }
+    }
+  }
+
+  return rc;
+}
+
+
+static int fts5ApiQueryPhrase(Fts5Context*, int, void*, 
+    int(*)(const Fts5ExtensionApi*, Fts5Context*, void*)
+);
+
+static const Fts5ExtensionApi sFts5Api = {
+  2,                            /* iVersion */
+  fts5ApiUserData,
+  fts5ApiColumnCount,
+  fts5ApiRowCount,
+  fts5ApiColumnTotalSize,
+  fts5ApiTokenize,
+  fts5ApiPhraseCount,
+  fts5ApiPhraseSize,
+  fts5ApiInstCount,
+  fts5ApiInst,
+  fts5ApiRowid,
+  fts5ApiColumnText,
+  fts5ApiColumnSize,
+  fts5ApiQueryPhrase,
+  fts5ApiSetAuxdata,
+  fts5ApiGetAuxdata,
+  fts5ApiPhraseFirst,
+  fts5ApiPhraseNext,
+  fts5ApiPhraseFirstColumn,
+  fts5ApiPhraseNextColumn,
+};
+
+/*
+** Implementation of API function xQueryPhrase().
+*/
+static int fts5ApiQueryPhrase(
+  Fts5Context *pCtx, 
+  int iPhrase, 
+  void *pUserData,
+  int(*xCallback)(const Fts5ExtensionApi*, Fts5Context*, void*)
+){
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
+  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
+  int rc;
+  Fts5Cursor *pNew = 0;
+
+  rc = fts5OpenMethod(pCsr->base.pVtab, (sqlite3_vtab_cursor**)&pNew);
+  if( rc==SQLITE_OK ){
+    pNew->ePlan = FTS5_PLAN_MATCH;
+    pNew->iFirstRowid = SMALLEST_INT64;
+    pNew->iLastRowid = LARGEST_INT64;
+    pNew->base.pVtab = (sqlite3_vtab*)pTab;
+    rc = sqlite3Fts5ExprClonePhrase(pCsr->pExpr, iPhrase, &pNew->pExpr);
+  }
+
+  if( rc==SQLITE_OK ){
+    for(rc = fts5CursorFirst(pTab, pNew, 0);
+        rc==SQLITE_OK && CsrFlagTest(pNew, FTS5CSR_EOF)==0;
+        rc = fts5NextMethod((sqlite3_vtab_cursor*)pNew)
+    ){
+      rc = xCallback(&sFts5Api, (Fts5Context*)pNew, pUserData);
+      if( rc!=SQLITE_OK ){
+        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+        break;
+      }
+    }
+  }
+
+  fts5CloseMethod((sqlite3_vtab_cursor*)pNew);
+  return rc;
+}
+
+static void fts5ApiInvoke(
+  Fts5Auxiliary *pAux,
+  Fts5Cursor *pCsr,
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( pCsr->pAux==0 );
+  pCsr->pAux = pAux;
+  pAux->xFunc(&sFts5Api, (Fts5Context*)pCsr, context, argc, argv);
+  pCsr->pAux = 0;
+}
+
+static Fts5Cursor *fts5CursorFromCsrid(Fts5Global *pGlobal, i64 iCsrId){
+  Fts5Cursor *pCsr;
+  for(pCsr=pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){
+    if( pCsr->iCsrId==iCsrId ) break;
+  }
+  return pCsr;
+}
+
+static void fts5ApiCallback(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+
+  Fts5Auxiliary *pAux;
+  Fts5Cursor *pCsr;
+  i64 iCsrId;
+
+  assert( argc>=1 );
+  pAux = (Fts5Auxiliary*)sqlite3_user_data(context);
+  iCsrId = sqlite3_value_int64(argv[0]);
+
+  pCsr = fts5CursorFromCsrid(pAux->pGlobal, iCsrId);
+  if( pCsr==0 ){
+    char *zErr = sqlite3_mprintf("no such cursor: %lld", iCsrId);
+    sqlite3_result_error(context, zErr, -1);
+    sqlite3_free(zErr);
+  }else{
+    fts5ApiInvoke(pAux, pCsr, context, argc-1, &argv[1]);
+  }
+}
+
+
+/*
+** Given cursor id iId, return a pointer to the corresponding Fts5Index 
+** object. Or NULL If the cursor id does not exist.
+**
+** If successful, set *ppConfig to point to the associated config object 
+** before returning.
+*/
+static Fts5Index *sqlite3Fts5IndexFromCsrid(
+  Fts5Global *pGlobal,            /* FTS5 global context for db handle */
+  i64 iCsrId,                     /* Id of cursor to find */
+  Fts5Config **ppConfig           /* OUT: Configuration object */
+){
+  Fts5Cursor *pCsr;
+  Fts5Table *pTab;
+
+  pCsr = fts5CursorFromCsrid(pGlobal, iCsrId);
+  pTab = (Fts5Table*)pCsr->base.pVtab;
+  *ppConfig = pTab->pConfig;
+
+  return pTab->pIndex;
+}
+
+/*
+** Return a "position-list blob" corresponding to the current position of
+** cursor pCsr via sqlite3_result_blob(). A position-list blob contains
+** the current position-list for each phrase in the query associated with
+** cursor pCsr.
+**
+** A position-list blob begins with (nPhrase-1) varints, where nPhrase is
+** the number of phrases in the query. Following the varints are the
+** concatenated position lists for each phrase, in order.
+**
+** The first varint (if it exists) contains the size of the position list
+** for phrase 0. The second (same disclaimer) contains the size of position
+** list 1. And so on. There is no size field for the final position list,
+** as it can be derived from the total size of the blob.
+*/
+static int fts5PoslistBlob(sqlite3_context *pCtx, Fts5Cursor *pCsr){
+  int i;
+  int rc = SQLITE_OK;
+  int nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
+  Fts5Buffer val;
+
+  memset(&val, 0, sizeof(Fts5Buffer));
+  switch( ((Fts5Table*)(pCsr->base.pVtab))->pConfig->eDetail ){
+    case FTS5_DETAIL_FULL:
+
+      /* Append the varints */
+      for(i=0; i<(nPhrase-1); i++){
+        const u8 *dummy;
+        int nByte = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &dummy);
+        sqlite3Fts5BufferAppendVarint(&rc, &val, nByte);
+      }
+
+      /* Append the position lists */
+      for(i=0; i<nPhrase; i++){
+        const u8 *pPoslist;
+        int nPoslist;
+        nPoslist = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &pPoslist);
+        sqlite3Fts5BufferAppendBlob(&rc, &val, nPoslist, pPoslist);
+      }
+      break;
+
+    case FTS5_DETAIL_COLUMNS:
+
+      /* Append the varints */
+      for(i=0; rc==SQLITE_OK && i<(nPhrase-1); i++){
+        const u8 *dummy;
+        int nByte;
+        rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, i, &dummy, &nByte);
+        sqlite3Fts5BufferAppendVarint(&rc, &val, nByte);
+      }
+
+      /* Append the position lists */
+      for(i=0; rc==SQLITE_OK && i<nPhrase; i++){
+        const u8 *pPoslist;
+        int nPoslist;
+        rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, i, &pPoslist, &nPoslist);
+        sqlite3Fts5BufferAppendBlob(&rc, &val, nPoslist, pPoslist);
+      }
+      break;
+
+    default:
+      break;
+  }
+
+  sqlite3_result_blob(pCtx, val.p, val.n, sqlite3_free);
+  return rc;
+}
+
+/* 
+** This is the xColumn method, called by SQLite to request a value from
+** the row that the supplied cursor currently points to.
+*/
+static int fts5ColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts5Table *pTab = (Fts5Table*)(pCursor->pVtab);
+  Fts5Config *pConfig = pTab->pConfig;
+  Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;
+  int rc = SQLITE_OK;
+  
+  assert( CsrFlagTest(pCsr, FTS5CSR_EOF)==0 );
+
+  if( pCsr->ePlan==FTS5_PLAN_SPECIAL ){
+    if( iCol==pConfig->nCol ){
+      sqlite3_result_int64(pCtx, pCsr->iSpecial);
+    }
+  }else
+
+  if( iCol==pConfig->nCol ){
+    /* User is requesting the value of the special column with the same name
+    ** as the table. Return the cursor integer id number. This value is only
+    ** useful in that it may be passed as the first argument to an FTS5
+    ** auxiliary function.  */
+    sqlite3_result_int64(pCtx, pCsr->iCsrId);
+  }else if( iCol==pConfig->nCol+1 ){
+
+    /* The value of the "rank" column. */
+    if( pCsr->ePlan==FTS5_PLAN_SOURCE ){
+      fts5PoslistBlob(pCtx, pCsr);
+    }else if( 
+        pCsr->ePlan==FTS5_PLAN_MATCH
+     || pCsr->ePlan==FTS5_PLAN_SORTED_MATCH
+    ){
+      if( pCsr->pRank || SQLITE_OK==(rc = fts5FindRankFunction(pCsr)) ){
+        fts5ApiInvoke(pCsr->pRank, pCsr, pCtx, pCsr->nRankArg, pCsr->apRankArg);
+      }
+    }
+  }else if( !fts5IsContentless(pTab) ){
+    rc = fts5SeekCursor(pCsr, 1);
+    if( rc==SQLITE_OK ){
+      sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));
+    }
+  }
+  return rc;
+}
+
+
+/*
+** This routine implements the xFindFunction method for the FTS3
+** virtual table.
+*/
+static int fts5FindFunctionMethod(
+  sqlite3_vtab *pVtab,            /* Virtual table handle */
+  int nUnused,                    /* Number of SQL function arguments */
+  const char *zName,              /* Name of SQL function */
+  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
+  void **ppArg                    /* OUT: User data for *pxFunc */
+){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  Fts5Auxiliary *pAux;
+
+  UNUSED_PARAM(nUnused);
+  pAux = fts5FindAuxiliary(pTab, zName);
+  if( pAux ){
+    *pxFunc = fts5ApiCallback;
+    *ppArg = (void*)pAux;
+    return 1;
+  }
+
+  /* No function of the specified name was found. Return 0. */
+  return 0;
+}
+
+/*
+** Implementation of FTS5 xRename method. Rename an fts5 table.
+*/
+static int fts5RenameMethod(
+  sqlite3_vtab *pVtab,            /* Virtual table handle */
+  const char *zName               /* New name of table */
+){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  return sqlite3Fts5StorageRename(pTab->pStorage, zName);
+}
+
+/*
+** The xSavepoint() method.
+**
+** Flush the contents of the pending-terms table to disk.
+*/
+static int fts5SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */
+  fts5CheckTransactionState(pTab, FTS5_SAVEPOINT, iSavepoint);
+  fts5TripCursors(pTab);
+  return sqlite3Fts5StorageSync(pTab->pStorage, 0);
+}
+
+/*
+** The xRelease() method.
+**
+** This is a no-op.
+*/
+static int fts5ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */
+  fts5CheckTransactionState(pTab, FTS5_RELEASE, iSavepoint);
+  fts5TripCursors(pTab);
+  return sqlite3Fts5StorageSync(pTab->pStorage, 0);
+}
+
+/*
+** The xRollbackTo() method.
+**
+** Discard the contents of the pending terms table.
+*/
+static int fts5RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
+  Fts5Table *pTab = (Fts5Table*)pVtab;
+  UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */
+  fts5CheckTransactionState(pTab, FTS5_ROLLBACKTO, iSavepoint);
+  fts5TripCursors(pTab);
+  return sqlite3Fts5StorageRollback(pTab->pStorage);
+}
+
+/*
+** Register a new auxiliary function with global context pGlobal.
+*/
+static int fts5CreateAux(
+  fts5_api *pApi,                 /* Global context (one per db handle) */
+  const char *zName,              /* Name of new function */
+  void *pUserData,                /* User data for aux. function */
+  fts5_extension_function xFunc,  /* Aux. function implementation */
+  void(*xDestroy)(void*)          /* Destructor for pUserData */
+){
+  Fts5Global *pGlobal = (Fts5Global*)pApi;
+  int rc = sqlite3_overload_function(pGlobal->db, zName, -1);
+  if( rc==SQLITE_OK ){
+    Fts5Auxiliary *pAux;
+    int nName;                      /* Size of zName in bytes, including \0 */
+    int nByte;                      /* Bytes of space to allocate */
+
+    nName = (int)strlen(zName) + 1;
+    nByte = sizeof(Fts5Auxiliary) + nName;
+    pAux = (Fts5Auxiliary*)sqlite3_malloc(nByte);
+    if( pAux ){
+      memset(pAux, 0, nByte);
+      pAux->zFunc = (char*)&pAux[1];
+      memcpy(pAux->zFunc, zName, nName);
+      pAux->pGlobal = pGlobal;
+      pAux->pUserData = pUserData;
+      pAux->xFunc = xFunc;
+      pAux->xDestroy = xDestroy;
+      pAux->pNext = pGlobal->pAux;
+      pGlobal->pAux = pAux;
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Register a new tokenizer. This is the implementation of the 
+** fts5_api.xCreateTokenizer() method.
+*/
+static int fts5CreateTokenizer(
+  fts5_api *pApi,                 /* Global context (one per db handle) */
+  const char *zName,              /* Name of new function */
+  void *pUserData,                /* User data for aux. function */
+  fts5_tokenizer *pTokenizer,     /* Tokenizer implementation */
+  void(*xDestroy)(void*)          /* Destructor for pUserData */
+){
+  Fts5Global *pGlobal = (Fts5Global*)pApi;
+  Fts5TokenizerModule *pNew;
+  int nName;                      /* Size of zName and its \0 terminator */
+  int nByte;                      /* Bytes of space to allocate */
+  int rc = SQLITE_OK;
+
+  nName = (int)strlen(zName) + 1;
+  nByte = sizeof(Fts5TokenizerModule) + nName;
+  pNew = (Fts5TokenizerModule*)sqlite3_malloc(nByte);
+  if( pNew ){
+    memset(pNew, 0, nByte);
+    pNew->zName = (char*)&pNew[1];
+    memcpy(pNew->zName, zName, nName);
+    pNew->pUserData = pUserData;
+    pNew->x = *pTokenizer;
+    pNew->xDestroy = xDestroy;
+    pNew->pNext = pGlobal->pTok;
+    pGlobal->pTok = pNew;
+    if( pNew->pNext==0 ){
+      pGlobal->pDfltTok = pNew;
+    }
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+
+  return rc;
+}
+
+static Fts5TokenizerModule *fts5LocateTokenizer(
+  Fts5Global *pGlobal, 
+  const char *zName
+){
+  Fts5TokenizerModule *pMod = 0;
+
+  if( zName==0 ){
+    pMod = pGlobal->pDfltTok;
+  }else{
+    for(pMod=pGlobal->pTok; pMod; pMod=pMod->pNext){
+      if( sqlite3_stricmp(zName, pMod->zName)==0 ) break;
+    }
+  }
+
+  return pMod;
+}
+
+/*
+** Find a tokenizer. This is the implementation of the 
+** fts5_api.xFindTokenizer() method.
+*/
+static int fts5FindTokenizer(
+  fts5_api *pApi,                 /* Global context (one per db handle) */
+  const char *zName,              /* Name of new function */
+  void **ppUserData,
+  fts5_tokenizer *pTokenizer      /* Populate this object */
+){
+  int rc = SQLITE_OK;
+  Fts5TokenizerModule *pMod;
+
+  pMod = fts5LocateTokenizer((Fts5Global*)pApi, zName);
+  if( pMod ){
+    *pTokenizer = pMod->x;
+    *ppUserData = pMod->pUserData;
+  }else{
+    memset(pTokenizer, 0, sizeof(fts5_tokenizer));
+    rc = SQLITE_ERROR;
+  }
+
+  return rc;
+}
+
+static int sqlite3Fts5GetTokenizer(
+  Fts5Global *pGlobal, 
+  const char **azArg,
+  int nArg,
+  Fts5Tokenizer **ppTok,
+  fts5_tokenizer **ppTokApi,
+  char **pzErr
+){
+  Fts5TokenizerModule *pMod;
+  int rc = SQLITE_OK;
+
+  pMod = fts5LocateTokenizer(pGlobal, nArg==0 ? 0 : azArg[0]);
+  if( pMod==0 ){
+    assert( nArg>0 );
+    rc = SQLITE_ERROR;
+    *pzErr = sqlite3_mprintf("no such tokenizer: %s", azArg[0]);
+  }else{
+    rc = pMod->x.xCreate(pMod->pUserData, &azArg[1], (nArg?nArg-1:0), ppTok);
+    *ppTokApi = &pMod->x;
+    if( rc!=SQLITE_OK && pzErr ){
+      *pzErr = sqlite3_mprintf("error in tokenizer constructor");
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    *ppTokApi = 0;
+    *ppTok = 0;
+  }
+
+  return rc;
+}
+
+static void fts5ModuleDestroy(void *pCtx){
+  Fts5TokenizerModule *pTok, *pNextTok;
+  Fts5Auxiliary *pAux, *pNextAux;
+  Fts5Global *pGlobal = (Fts5Global*)pCtx;
+
+  for(pAux=pGlobal->pAux; pAux; pAux=pNextAux){
+    pNextAux = pAux->pNext;
+    if( pAux->xDestroy ) pAux->xDestroy(pAux->pUserData);
+    sqlite3_free(pAux);
+  }
+
+  for(pTok=pGlobal->pTok; pTok; pTok=pNextTok){
+    pNextTok = pTok->pNext;
+    if( pTok->xDestroy ) pTok->xDestroy(pTok->pUserData);
+    sqlite3_free(pTok);
+  }
+
+  sqlite3_free(pGlobal);
+}
+
+static void fts5Fts5Func(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apUnused        /* Function arguments */
+){
+  Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);
+  char buf[8];
+  UNUSED_PARAM2(nArg, apUnused);
+  assert( nArg==0 );
+  assert( sizeof(buf)>=sizeof(pGlobal) );
+  memcpy(buf, (void*)&pGlobal, sizeof(pGlobal));
+  sqlite3_result_blob(pCtx, buf, sizeof(pGlobal), SQLITE_TRANSIENT);
+}
+
+/*
+** Implementation of fts5_source_id() function.
+*/
+static void fts5SourceIdFunc(
+  sqlite3_context *pCtx,          /* Function call context */
+  int nArg,                       /* Number of args */
+  sqlite3_value **apUnused        /* Function arguments */
+){
+  assert( nArg==0 );
+  UNUSED_PARAM2(nArg, apUnused);
+  sqlite3_result_text(pCtx, "fts5: 2016-08-11 18:53:32 a12d8059770df4bca59e321c266410344242bf7b", -1, SQLITE_TRANSIENT);
+}
+
+static int fts5Init(sqlite3 *db){
+  static const sqlite3_module fts5Mod = {
+    /* iVersion      */ 2,
+    /* xCreate       */ fts5CreateMethod,
+    /* xConnect      */ fts5ConnectMethod,
+    /* xBestIndex    */ fts5BestIndexMethod,
+    /* xDisconnect   */ fts5DisconnectMethod,
+    /* xDestroy      */ fts5DestroyMethod,
+    /* xOpen         */ fts5OpenMethod,
+    /* xClose        */ fts5CloseMethod,
+    /* xFilter       */ fts5FilterMethod,
+    /* xNext         */ fts5NextMethod,
+    /* xEof          */ fts5EofMethod,
+    /* xColumn       */ fts5ColumnMethod,
+    /* xRowid        */ fts5RowidMethod,
+    /* xUpdate       */ fts5UpdateMethod,
+    /* xBegin        */ fts5BeginMethod,
+    /* xSync         */ fts5SyncMethod,
+    /* xCommit       */ fts5CommitMethod,
+    /* xRollback     */ fts5RollbackMethod,
+    /* xFindFunction */ fts5FindFunctionMethod,
+    /* xRename       */ fts5RenameMethod,
+    /* xSavepoint    */ fts5SavepointMethod,
+    /* xRelease      */ fts5ReleaseMethod,
+    /* xRollbackTo   */ fts5RollbackToMethod,
+  };
+
+  int rc;
+  Fts5Global *pGlobal = 0;
+
+  pGlobal = (Fts5Global*)sqlite3_malloc(sizeof(Fts5Global));
+  if( pGlobal==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    void *p = (void*)pGlobal;
+    memset(pGlobal, 0, sizeof(Fts5Global));
+    pGlobal->db = db;
+    pGlobal->api.iVersion = 2;
+    pGlobal->api.xCreateFunction = fts5CreateAux;
+    pGlobal->api.xCreateTokenizer = fts5CreateTokenizer;
+    pGlobal->api.xFindTokenizer = fts5FindTokenizer;
+    rc = sqlite3_create_module_v2(db, "fts5", &fts5Mod, p, fts5ModuleDestroy);
+    if( rc==SQLITE_OK ) rc = sqlite3Fts5IndexInit(db);
+    if( rc==SQLITE_OK ) rc = sqlite3Fts5ExprInit(pGlobal, db);
+    if( rc==SQLITE_OK ) rc = sqlite3Fts5AuxInit(&pGlobal->api);
+    if( rc==SQLITE_OK ) rc = sqlite3Fts5TokenizerInit(&pGlobal->api);
+    if( rc==SQLITE_OK ) rc = sqlite3Fts5VocabInit(pGlobal, db);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_create_function(
+          db, "fts5", 0, SQLITE_UTF8, p, fts5Fts5Func, 0, 0
+      );
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3_create_function(
+          db, "fts5_source_id", 0, SQLITE_UTF8, p, fts5SourceIdFunc, 0, 0
+      );
+    }
+  }
+
+  /* If SQLITE_FTS5_ENABLE_TEST_MI is defined, assume that the file
+  ** fts5_test_mi.c is compiled and linked into the executable. And call
+  ** its entry point to enable the matchinfo() demo.  */
+#ifdef SQLITE_FTS5_ENABLE_TEST_MI
+  if( rc==SQLITE_OK ){
+    extern int sqlite3Fts5TestRegisterMatchinfo(sqlite3*);
+    rc = sqlite3Fts5TestRegisterMatchinfo(db);
+  }
+#endif
+
+  return rc;
+}
+
+/*
+** The following functions are used to register the module with SQLite. If
+** this module is being built as part of the SQLite core (SQLITE_CORE is
+** defined), then sqlite3_open() will call sqlite3Fts5Init() directly.
+**
+** Or, if this module is being built as a loadable extension, 
+** sqlite3Fts5Init() is omitted and the two standard entry points
+** sqlite3_fts_init() and sqlite3_fts5_init() defined instead.
+*/
+#ifndef SQLITE_CORE
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_fts_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  return fts5Init(db);
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+SQLITE_API int SQLITE_STDCALL sqlite3_fts5_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  return fts5Init(db);
+}
+#else
+SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3 *db){
+  return fts5Init(db);
+}
+#endif
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+*/
+
+
+
+/* #include "fts5Int.h" */
+
+struct Fts5Storage {
+  Fts5Config *pConfig;
+  Fts5Index *pIndex;
+  int bTotalsValid;               /* True if nTotalRow/aTotalSize[] are valid */
+  i64 nTotalRow;                  /* Total number of rows in FTS table */
+  i64 *aTotalSize;                /* Total sizes of each column */ 
+  sqlite3_stmt *aStmt[11];
+};
+
+
+#if FTS5_STMT_SCAN_ASC!=0 
+# error "FTS5_STMT_SCAN_ASC mismatch" 
+#endif
+#if FTS5_STMT_SCAN_DESC!=1 
+# error "FTS5_STMT_SCAN_DESC mismatch" 
+#endif
+#if FTS5_STMT_LOOKUP!=2
+# error "FTS5_STMT_LOOKUP mismatch" 
+#endif
+
+#define FTS5_STMT_INSERT_CONTENT  3
+#define FTS5_STMT_REPLACE_CONTENT 4
+#define FTS5_STMT_DELETE_CONTENT  5
+#define FTS5_STMT_REPLACE_DOCSIZE  6
+#define FTS5_STMT_DELETE_DOCSIZE  7
+#define FTS5_STMT_LOOKUP_DOCSIZE  8
+#define FTS5_STMT_REPLACE_CONFIG 9
+#define FTS5_STMT_SCAN 10
+
+/*
+** Prepare the two insert statements - Fts5Storage.pInsertContent and
+** Fts5Storage.pInsertDocsize - if they have not already been prepared.
+** Return SQLITE_OK if successful, or an SQLite error code if an error
+** occurs.
+*/
+static int fts5StorageGetStmt(
+  Fts5Storage *p,                 /* Storage handle */
+  int eStmt,                      /* FTS5_STMT_XXX constant */
+  sqlite3_stmt **ppStmt,          /* OUT: Prepared statement handle */
+  char **pzErrMsg                 /* OUT: Error message (if any) */
+){
+  int rc = SQLITE_OK;
+
+  /* If there is no %_docsize table, there should be no requests for 
+  ** statements to operate on it.  */
+  assert( p->pConfig->bColumnsize || (
+        eStmt!=FTS5_STMT_REPLACE_DOCSIZE 
+     && eStmt!=FTS5_STMT_DELETE_DOCSIZE 
+     && eStmt!=FTS5_STMT_LOOKUP_DOCSIZE 
+  ));
+
+  assert( eStmt>=0 && eStmt<ArraySize(p->aStmt) );
+  if( p->aStmt[eStmt]==0 ){
+    const char *azStmt[] = {
+      "SELECT %s FROM %s T WHERE T.%Q >= ? AND T.%Q <= ? ORDER BY T.%Q ASC",
+      "SELECT %s FROM %s T WHERE T.%Q <= ? AND T.%Q >= ? ORDER BY T.%Q DESC",
+      "SELECT %s FROM %s T WHERE T.%Q=?",               /* LOOKUP  */
+
+      "INSERT INTO %Q.'%q_content' VALUES(%s)",         /* INSERT_CONTENT  */
+      "REPLACE INTO %Q.'%q_content' VALUES(%s)",        /* REPLACE_CONTENT */
+      "DELETE FROM %Q.'%q_content' WHERE id=?",         /* DELETE_CONTENT  */
+      "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",       /* REPLACE_DOCSIZE  */
+      "DELETE FROM %Q.'%q_docsize' WHERE id=?",         /* DELETE_DOCSIZE  */
+
+      "SELECT sz FROM %Q.'%q_docsize' WHERE id=?",      /* LOOKUP_DOCSIZE  */
+
+      "REPLACE INTO %Q.'%q_config' VALUES(?,?)",        /* REPLACE_CONFIG */
+      "SELECT %s FROM %s AS T",                         /* SCAN */
+    };
+    Fts5Config *pC = p->pConfig;
+    char *zSql = 0;
+
+    switch( eStmt ){
+      case FTS5_STMT_SCAN:
+        zSql = sqlite3_mprintf(azStmt[eStmt], 
+            pC->zContentExprlist, pC->zContent
+        );
+        break;
+
+      case FTS5_STMT_SCAN_ASC:
+      case FTS5_STMT_SCAN_DESC:
+        zSql = sqlite3_mprintf(azStmt[eStmt], pC->zContentExprlist, 
+            pC->zContent, pC->zContentRowid, pC->zContentRowid,
+            pC->zContentRowid
+        );
+        break;
+
+      case FTS5_STMT_LOOKUP:
+        zSql = sqlite3_mprintf(azStmt[eStmt], 
+            pC->zContentExprlist, pC->zContent, pC->zContentRowid
+        );
+        break;
+
+      case FTS5_STMT_INSERT_CONTENT: 
+      case FTS5_STMT_REPLACE_CONTENT: {
+        int nCol = pC->nCol + 1;
+        char *zBind;
+        int i;
+
+        zBind = sqlite3_malloc(1 + nCol*2);
+        if( zBind ){
+          for(i=0; i<nCol; i++){
+            zBind[i*2] = '?';
+            zBind[i*2 + 1] = ',';
+          }
+          zBind[i*2-1] = '\0';
+          zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName, zBind);
+          sqlite3_free(zBind);
+        }
+        break;
+      }
+
+      default:
+        zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName);
+        break;
+    }
+
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v2(pC->db, zSql, -1, &p->aStmt[eStmt], 0);
+      sqlite3_free(zSql);
+      if( rc!=SQLITE_OK && pzErrMsg ){
+        *pzErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pC->db));
+      }
+    }
+  }
+
+  *ppStmt = p->aStmt[eStmt];
+  sqlite3_reset(*ppStmt);
+  return rc;
+}
+
+
+static int fts5ExecPrintf(
+  sqlite3 *db,
+  char **pzErr,
+  const char *zFormat,
+  ...
+){
+  int rc;
+  va_list ap;                     /* ... printf arguments */
+  char *zSql;
+
+  va_start(ap, zFormat);
+  zSql = sqlite3_vmprintf(zFormat, ap);
+
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_exec(db, zSql, 0, 0, pzErr);
+    sqlite3_free(zSql);
+  }
+
+  va_end(ap);
+  return rc;
+}
+
+/*
+** Drop all shadow tables. Return SQLITE_OK if successful or an SQLite error
+** code otherwise.
+*/
+static int sqlite3Fts5DropAll(Fts5Config *pConfig){
+  int rc = fts5ExecPrintf(pConfig->db, 0, 
+      "DROP TABLE IF EXISTS %Q.'%q_data';"
+      "DROP TABLE IF EXISTS %Q.'%q_idx';"
+      "DROP TABLE IF EXISTS %Q.'%q_config';",
+      pConfig->zDb, pConfig->zName,
+      pConfig->zDb, pConfig->zName,
+      pConfig->zDb, pConfig->zName
+  );
+  if( rc==SQLITE_OK && pConfig->bColumnsize ){
+    rc = fts5ExecPrintf(pConfig->db, 0, 
+        "DROP TABLE IF EXISTS %Q.'%q_docsize';",
+        pConfig->zDb, pConfig->zName
+    );
+  }
+  if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){
+    rc = fts5ExecPrintf(pConfig->db, 0, 
+        "DROP TABLE IF EXISTS %Q.'%q_content';",
+        pConfig->zDb, pConfig->zName
+    );
+  }
+  return rc;
+}
+
+static void fts5StorageRenameOne(
+  Fts5Config *pConfig,            /* Current FTS5 configuration */
+  int *pRc,                       /* IN/OUT: Error code */
+  const char *zTail,              /* Tail of table name e.g. "data", "config" */
+  const char *zName               /* New name of FTS5 table */
+){
+  if( *pRc==SQLITE_OK ){
+    *pRc = fts5ExecPrintf(pConfig->db, 0, 
+        "ALTER TABLE %Q.'%q_%s' RENAME TO '%q_%s';",
+        pConfig->zDb, pConfig->zName, zTail, zName, zTail
+    );
+  }
+}
+
+static int sqlite3Fts5StorageRename(Fts5Storage *pStorage, const char *zName){
+  Fts5Config *pConfig = pStorage->pConfig;
+  int rc = sqlite3Fts5StorageSync(pStorage, 1);
+
+  fts5StorageRenameOne(pConfig, &rc, "data", zName);
+  fts5StorageRenameOne(pConfig, &rc, "idx", zName);
+  fts5StorageRenameOne(pConfig, &rc, "config", zName);
+  if( pConfig->bColumnsize ){
+    fts5StorageRenameOne(pConfig, &rc, "docsize", zName);
+  }
+  if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
+    fts5StorageRenameOne(pConfig, &rc, "content", zName);
+  }
+  return rc;
+}
+
+/*
+** Create the shadow table named zPost, with definition zDefn. Return
+** SQLITE_OK if successful, or an SQLite error code otherwise.
+*/
+static int sqlite3Fts5CreateTable(
+  Fts5Config *pConfig,            /* FTS5 configuration */
+  const char *zPost,              /* Shadow table to create (e.g. "content") */
+  const char *zDefn,              /* Columns etc. for shadow table */
+  int bWithout,                   /* True for without rowid */
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc;
+  char *zErr = 0;
+
+  rc = fts5ExecPrintf(pConfig->db, &zErr, "CREATE TABLE %Q.'%q_%q'(%s)%s",
+      pConfig->zDb, pConfig->zName, zPost, zDefn, 
+#ifndef SQLITE_FTS5_NO_WITHOUT_ROWID
+      bWithout?" WITHOUT ROWID":
+#endif
+      ""
+  );
+  if( zErr ){
+    *pzErr = sqlite3_mprintf(
+        "fts5: error creating shadow table %q_%s: %s", 
+        pConfig->zName, zPost, zErr
+    );
+    sqlite3_free(zErr);
+  }
+
+  return rc;
+}
+
+/*
+** Open a new Fts5Index handle. If the bCreate argument is true, create
+** and initialize the underlying tables 
+**
+** If successful, set *pp to point to the new object and return SQLITE_OK.
+** Otherwise, set *pp to NULL and return an SQLite error code.
+*/
+static int sqlite3Fts5StorageOpen(
+  Fts5Config *pConfig, 
+  Fts5Index *pIndex, 
+  int bCreate, 
+  Fts5Storage **pp,
+  char **pzErr                    /* OUT: Error message */
+){
+  int rc = SQLITE_OK;
+  Fts5Storage *p;                 /* New object */
+  int nByte;                      /* Bytes of space to allocate */
+
+  nByte = sizeof(Fts5Storage)               /* Fts5Storage object */
+        + pConfig->nCol * sizeof(i64);      /* Fts5Storage.aTotalSize[] */
+  *pp = p = (Fts5Storage*)sqlite3_malloc(nByte);
+  if( !p ) return SQLITE_NOMEM;
+
+  memset(p, 0, nByte);
+  p->aTotalSize = (i64*)&p[1];
+  p->pConfig = pConfig;
+  p->pIndex = pIndex;
+
+  if( bCreate ){
+    if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
+      int nDefn = 32 + pConfig->nCol*10;
+      char *zDefn = sqlite3_malloc(32 + pConfig->nCol * 10);
+      if( zDefn==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        int i;
+        int iOff;
+        sqlite3_snprintf(nDefn, zDefn, "id INTEGER PRIMARY KEY");
+        iOff = (int)strlen(zDefn);
+        for(i=0; i<pConfig->nCol; i++){
+          sqlite3_snprintf(nDefn-iOff, &zDefn[iOff], ", c%d", i);
+          iOff += (int)strlen(&zDefn[iOff]);
+        }
+        rc = sqlite3Fts5CreateTable(pConfig, "content", zDefn, 0, pzErr);
+      }
+      sqlite3_free(zDefn);
+    }
+
+    if( rc==SQLITE_OK && pConfig->bColumnsize ){
+      rc = sqlite3Fts5CreateTable(
+          pConfig, "docsize", "id INTEGER PRIMARY KEY, sz BLOB", 0, pzErr
+      );
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts5CreateTable(
+          pConfig, "config", "k PRIMARY KEY, v", 1, pzErr
+      );
+    }
+    if( rc==SQLITE_OK ){
+      rc = sqlite3Fts5StorageConfigValue(p, "version", 0, FTS5_CURRENT_VERSION);
+    }
+  }
+
+  if( rc ){
+    sqlite3Fts5StorageClose(p);
+    *pp = 0;
+  }
+  return rc;
+}
+
+/*
+** Close a handle opened by an earlier call to sqlite3Fts5StorageOpen().
+*/
+static int sqlite3Fts5StorageClose(Fts5Storage *p){
+  int rc = SQLITE_OK;
+  if( p ){
+    int i;
+
+    /* Finalize all SQL statements */
+    for(i=0; i<ArraySize(p->aStmt); i++){
+      sqlite3_finalize(p->aStmt[i]);
+    }
+
+    sqlite3_free(p);
+  }
+  return rc;
+}
+
+typedef struct Fts5InsertCtx Fts5InsertCtx;
+struct Fts5InsertCtx {
+  Fts5Storage *pStorage;
+  int iCol;
+  int szCol;                      /* Size of column value in tokens */
+};
+
+/*
+** Tokenization callback used when inserting tokens into the FTS index.
+*/
+static int fts5StorageInsertCallback(
+  void *pContext,                 /* Pointer to Fts5InsertCtx object */
+  int tflags,
+  const char *pToken,             /* Buffer containing token */
+  int nToken,                     /* Size of token in bytes */
+  int iUnused1,                   /* Start offset of token */
+  int iUnused2                    /* End offset of token */
+){
+  Fts5InsertCtx *pCtx = (Fts5InsertCtx*)pContext;
+  Fts5Index *pIdx = pCtx->pStorage->pIndex;
+  UNUSED_PARAM2(iUnused1, iUnused2);
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
+  if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
+    pCtx->szCol++;
+  }
+  return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, pCtx->szCol-1, pToken, nToken);
+}
+
+/*
+** If a row with rowid iDel is present in the %_content table, add the
+** delete-markers to the FTS index necessary to delete it. Do not actually
+** remove the %_content row at this time though.
+*/
+static int fts5StorageDeleteFromIndex(
+  Fts5Storage *p, 
+  i64 iDel, 
+  sqlite3_value **apVal
+){
+  Fts5Config *pConfig = p->pConfig;
+  sqlite3_stmt *pSeek = 0;        /* SELECT to read row iDel from %_data */
+  int rc;                         /* Return code */
+  int rc2;                        /* sqlite3_reset() return code */
+  int iCol;
+  Fts5InsertCtx ctx;
+
+  if( apVal==0 ){
+    rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP, &pSeek, 0);
+    if( rc!=SQLITE_OK ) return rc;
+    sqlite3_bind_int64(pSeek, 1, iDel);
+    if( sqlite3_step(pSeek)!=SQLITE_ROW ){
+      return sqlite3_reset(pSeek);
+    }
+  }
+
+  ctx.pStorage = p;
+  ctx.iCol = -1;
+  rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 1, iDel);
+  for(iCol=1; rc==SQLITE_OK && iCol<=pConfig->nCol; iCol++){
+    if( pConfig->abUnindexed[iCol-1]==0 ){
+      const char *zText;
+      int nText;
+      if( pSeek ){
+        zText = (const char*)sqlite3_column_text(pSeek, iCol);
+        nText = sqlite3_column_bytes(pSeek, iCol);
+      }else{
+        zText = (const char*)sqlite3_value_text(apVal[iCol-1]);
+        nText = sqlite3_value_bytes(apVal[iCol-1]);
+      }
+      ctx.szCol = 0;
+      rc = sqlite3Fts5Tokenize(pConfig, FTS5_TOKENIZE_DOCUMENT, 
+          zText, nText, (void*)&ctx, fts5StorageInsertCallback
+      );
+      p->aTotalSize[iCol-1] -= (i64)ctx.szCol;
+    }
+  }
+  p->nTotalRow--;
+
+  rc2 = sqlite3_reset(pSeek);
+  if( rc==SQLITE_OK ) rc = rc2;
+  return rc;
+}
+
+
+/*
+** Insert a record into the %_docsize table. Specifically, do:
+**
+**   INSERT OR REPLACE INTO %_docsize(id, sz) VALUES(iRowid, pBuf);
+**
+** If there is no %_docsize table (as happens if the columnsize=0 option
+** is specified when the FTS5 table is created), this function is a no-op.
+*/
+static int fts5StorageInsertDocsize(
+  Fts5Storage *p,                 /* Storage module to write to */
+  i64 iRowid,                     /* id value */
+  Fts5Buffer *pBuf                /* sz value */
+){
+  int rc = SQLITE_OK;
+  if( p->pConfig->bColumnsize ){
+    sqlite3_stmt *pReplace = 0;
+    rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pReplace, 1, iRowid);
+      sqlite3_bind_blob(pReplace, 2, pBuf->p, pBuf->n, SQLITE_STATIC);
+      sqlite3_step(pReplace);
+      rc = sqlite3_reset(pReplace);
+    }
+  }
+  return rc;
+}
+
+/*
+** Load the contents of the "averages" record from disk into the 
+** p->nTotalRow and p->aTotalSize[] variables. If successful, and if
+** argument bCache is true, set the p->bTotalsValid flag to indicate
+** that the contents of aTotalSize[] and nTotalRow are valid until
+** further notice.
+**
+** Return SQLITE_OK if successful, or an SQLite error code if an error
+** occurs.
+*/
+static int fts5StorageLoadTotals(Fts5Storage *p, int bCache){
+  int rc = SQLITE_OK;
+  if( p->bTotalsValid==0 ){
+    rc = sqlite3Fts5IndexGetAverages(p->pIndex, &p->nTotalRow, p->aTotalSize);
+    p->bTotalsValid = bCache;
+  }
+  return rc;
+}
+
+/*
+** Store the current contents of the p->nTotalRow and p->aTotalSize[] 
+** variables in the "averages" record on disk.
+**
+** Return SQLITE_OK if successful, or an SQLite error code if an error
+** occurs.
+*/
+static int fts5StorageSaveTotals(Fts5Storage *p){
+  int nCol = p->pConfig->nCol;
+  int i;
+  Fts5Buffer buf;
+  int rc = SQLITE_OK;
+  memset(&buf, 0, sizeof(buf));
+
+  sqlite3Fts5BufferAppendVarint(&rc, &buf, p->nTotalRow);
+  for(i=0; i<nCol; i++){
+    sqlite3Fts5BufferAppendVarint(&rc, &buf, p->aTotalSize[i]);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexSetAverages(p->pIndex, buf.p, buf.n);
+  }
+  sqlite3_free(buf.p);
+
+  return rc;
+}
+
+/*
+** Remove a row from the FTS table.
+*/
+static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64 iDel, sqlite3_value **apVal){
+  Fts5Config *pConfig = p->pConfig;
+  int rc;
+  sqlite3_stmt *pDel = 0;
+
+  assert( pConfig->eContent!=FTS5_CONTENT_NORMAL || apVal==0 );
+  rc = fts5StorageLoadTotals(p, 1);
+
+  /* Delete the index records */
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageDeleteFromIndex(p, iDel, apVal);
+  }
+
+  /* Delete the %_docsize record */
+  if( rc==SQLITE_OK && pConfig->bColumnsize ){
+    rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_DOCSIZE, &pDel, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDel, 1, iDel);
+      sqlite3_step(pDel);
+      rc = sqlite3_reset(pDel);
+    }
+  }
+
+  /* Delete the %_content record */
+  if( pConfig->eContent==FTS5_CONTENT_NORMAL ){
+    if( rc==SQLITE_OK ){
+      rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_CONTENT, &pDel, 0);
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_int64(pDel, 1, iDel);
+      sqlite3_step(pDel);
+      rc = sqlite3_reset(pDel);
+    }
+  }
+
+  /* Write the averages record */
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageSaveTotals(p);
+  }
+
+  return rc;
+}
+
+/*
+** Delete all entries in the FTS5 index.
+*/
+static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p){
+  Fts5Config *pConfig = p->pConfig;
+  int rc;
+
+  /* Delete the contents of the %_data and %_docsize tables. */
+  rc = fts5ExecPrintf(pConfig->db, 0,
+      "DELETE FROM %Q.'%q_data';" 
+      "DELETE FROM %Q.'%q_idx';",
+      pConfig->zDb, pConfig->zName,
+      pConfig->zDb, pConfig->zName
+  );
+  if( rc==SQLITE_OK && pConfig->bColumnsize ){
+    rc = fts5ExecPrintf(pConfig->db, 0,
+        "DELETE FROM %Q.'%q_docsize';",
+        pConfig->zDb, pConfig->zName
+    );
+  }
+
+  /* Reinitialize the %_data table. This call creates the initial structure
+  ** and averages records.  */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexReinit(p->pIndex);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5StorageConfigValue(p, "version", 0, FTS5_CURRENT_VERSION);
+  }
+  return rc;
+}
+
+static int sqlite3Fts5StorageRebuild(Fts5Storage *p){
+  Fts5Buffer buf = {0,0,0};
+  Fts5Config *pConfig = p->pConfig;
+  sqlite3_stmt *pScan = 0;
+  Fts5InsertCtx ctx;
+  int rc;
+
+  memset(&ctx, 0, sizeof(Fts5InsertCtx));
+  ctx.pStorage = p;
+  rc = sqlite3Fts5StorageDeleteAll(p);
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageLoadTotals(p, 1);
+  }
+
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);
+  }
+
+  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pScan) ){
+    i64 iRowid = sqlite3_column_int64(pScan, 0);
+
+    sqlite3Fts5BufferZero(&buf);
+    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);
+    for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
+      ctx.szCol = 0;
+      if( pConfig->abUnindexed[ctx.iCol]==0 ){
+        rc = sqlite3Fts5Tokenize(pConfig, 
+            FTS5_TOKENIZE_DOCUMENT,
+            (const char*)sqlite3_column_text(pScan, ctx.iCol+1),
+            sqlite3_column_bytes(pScan, ctx.iCol+1),
+            (void*)&ctx,
+            fts5StorageInsertCallback
+        );
+      }
+      sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);
+      p->aTotalSize[ctx.iCol] += (i64)ctx.szCol;
+    }
+    p->nTotalRow++;
+
+    if( rc==SQLITE_OK ){
+      rc = fts5StorageInsertDocsize(p, iRowid, &buf);
+    }
+  }
+  sqlite3_free(buf.p);
+
+  /* Write the averages record */
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageSaveTotals(p);
+  }
+  return rc;
+}
+
+static int sqlite3Fts5StorageOptimize(Fts5Storage *p){
+  return sqlite3Fts5IndexOptimize(p->pIndex);
+}
+
+static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge){
+  return sqlite3Fts5IndexMerge(p->pIndex, nMerge);
+}
+
+static int sqlite3Fts5StorageReset(Fts5Storage *p){
+  return sqlite3Fts5IndexReset(p->pIndex);
+}
+
+/*
+** Allocate a new rowid. This is used for "external content" tables when
+** a NULL value is inserted into the rowid column. The new rowid is allocated
+** by inserting a dummy row into the %_docsize table. The dummy will be
+** overwritten later.
+**
+** If the %_docsize table does not exist, SQLITE_MISMATCH is returned. In
+** this case the user is required to provide a rowid explicitly.
+*/
+static int fts5StorageNewRowid(Fts5Storage *p, i64 *piRowid){
+  int rc = SQLITE_MISMATCH;
+  if( p->pConfig->bColumnsize ){
+    sqlite3_stmt *pReplace = 0;
+    rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace, 0);
+    if( rc==SQLITE_OK ){
+      sqlite3_bind_null(pReplace, 1);
+      sqlite3_bind_null(pReplace, 2);
+      sqlite3_step(pReplace);
+      rc = sqlite3_reset(pReplace);
+    }
+    if( rc==SQLITE_OK ){
+      *piRowid = sqlite3_last_insert_rowid(p->pConfig->db);
+    }
+  }
+  return rc;
+}
+
+/*
+** Insert a new row into the FTS content table.
+*/
+static int sqlite3Fts5StorageContentInsert(
+  Fts5Storage *p, 
+  sqlite3_value **apVal, 
+  i64 *piRowid
+){
+  Fts5Config *pConfig = p->pConfig;
+  int rc = SQLITE_OK;
+
+  /* Insert the new row into the %_content table. */
+  if( pConfig->eContent!=FTS5_CONTENT_NORMAL ){
+    if( sqlite3_value_type(apVal[1])==SQLITE_INTEGER ){
+      *piRowid = sqlite3_value_int64(apVal[1]);
+    }else{
+      rc = fts5StorageNewRowid(p, piRowid);
+    }
+  }else{
+    sqlite3_stmt *pInsert = 0;    /* Statement to write %_content table */
+    int i;                        /* Counter variable */
+    rc = fts5StorageGetStmt(p, FTS5_STMT_INSERT_CONTENT, &pInsert, 0);
+    for(i=1; rc==SQLITE_OK && i<=pConfig->nCol+1; i++){
+      rc = sqlite3_bind_value(pInsert, i, apVal[i]);
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3_step(pInsert);
+      rc = sqlite3_reset(pInsert);
+    }
+    *piRowid = sqlite3_last_insert_rowid(pConfig->db);
+  }
+
+  return rc;
+}
+
+/*
+** Insert new entries into the FTS index and %_docsize table.
+*/
+static int sqlite3Fts5StorageIndexInsert(
+  Fts5Storage *p, 
+  sqlite3_value **apVal, 
+  i64 iRowid
+){
+  Fts5Config *pConfig = p->pConfig;
+  int rc = SQLITE_OK;             /* Return code */
+  Fts5InsertCtx ctx;              /* Tokenization callback context object */
+  Fts5Buffer buf;                 /* Buffer used to build up %_docsize blob */
+
+  memset(&buf, 0, sizeof(Fts5Buffer));
+  ctx.pStorage = p;
+  rc = fts5StorageLoadTotals(p, 1);
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);
+  }
+  for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
+    ctx.szCol = 0;
+    if( pConfig->abUnindexed[ctx.iCol]==0 ){
+      rc = sqlite3Fts5Tokenize(pConfig, 
+          FTS5_TOKENIZE_DOCUMENT,
+          (const char*)sqlite3_value_text(apVal[ctx.iCol+2]),
+          sqlite3_value_bytes(apVal[ctx.iCol+2]),
+          (void*)&ctx,
+          fts5StorageInsertCallback
+      );
+    }
+    sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);
+    p->aTotalSize[ctx.iCol] += (i64)ctx.szCol;
+  }
+  p->nTotalRow++;
+
+  /* Write the %_docsize record */
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageInsertDocsize(p, iRowid, &buf);
+  }
+  sqlite3_free(buf.p);
+
+  /* Write the averages record */
+  if( rc==SQLITE_OK ){
+    rc = fts5StorageSaveTotals(p);
+  }
+
+  return rc;
+}
+
+static int fts5StorageCount(Fts5Storage *p, const char *zSuffix, i64 *pnRow){
+  Fts5Config *pConfig = p->pConfig;
+  char *zSql;
+  int rc;
+
+  zSql = sqlite3_mprintf("SELECT count(*) FROM %Q.'%q_%s'", 
+      pConfig->zDb, pConfig->zName, zSuffix
+  );
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    sqlite3_stmt *pCnt = 0;
+    rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &pCnt, 0);
+    if( rc==SQLITE_OK ){
+      if( SQLITE_ROW==sqlite3_step(pCnt) ){
+        *pnRow = sqlite3_column_int64(pCnt, 0);
+      }
+      rc = sqlite3_finalize(pCnt);
+    }
+  }
+
+  sqlite3_free(zSql);
+  return rc;
+}
+
+/*
+** Context object used by sqlite3Fts5StorageIntegrity().
+*/
+typedef struct Fts5IntegrityCtx Fts5IntegrityCtx;
+struct Fts5IntegrityCtx {
+  i64 iRowid;
+  int iCol;
+  int szCol;
+  u64 cksum;
+  Fts5Termset *pTermset;
+  Fts5Config *pConfig;
+};
+
+
+/*
+** Tokenization callback used by integrity check.
+*/
+static int fts5StorageIntegrityCallback(
+  void *pContext,                 /* Pointer to Fts5IntegrityCtx object */
+  int tflags,
+  const char *pToken,             /* Buffer containing token */
+  int nToken,                     /* Size of token in bytes */
+  int iUnused1,                   /* Start offset of token */
+  int iUnused2                    /* End offset of token */
+){
+  Fts5IntegrityCtx *pCtx = (Fts5IntegrityCtx*)pContext;
+  Fts5Termset *pTermset = pCtx->pTermset;
+  int bPresent;
+  int ii;
+  int rc = SQLITE_OK;
+  int iPos;
+  int iCol;
+
+  UNUSED_PARAM2(iUnused1, iUnused2);
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
+
+  if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
+    pCtx->szCol++;
+  }
+
+  switch( pCtx->pConfig->eDetail ){
+    case FTS5_DETAIL_FULL:
+      iPos = pCtx->szCol-1;
+      iCol = pCtx->iCol;
+      break;
+
+    case FTS5_DETAIL_COLUMNS:
+      iPos = pCtx->iCol;
+      iCol = 0;
+      break;
+
+    default:
+      assert( pCtx->pConfig->eDetail==FTS5_DETAIL_NONE );
+      iPos = 0;
+      iCol = 0;
+      break;
+  }
+
+  rc = sqlite3Fts5TermsetAdd(pTermset, 0, pToken, nToken, &bPresent);
+  if( rc==SQLITE_OK && bPresent==0 ){
+    pCtx->cksum ^= sqlite3Fts5IndexEntryCksum(
+        pCtx->iRowid, iCol, iPos, 0, pToken, nToken
+    );
+  }
+
+  for(ii=0; rc==SQLITE_OK && ii<pCtx->pConfig->nPrefix; ii++){
+    const int nChar = pCtx->pConfig->aPrefix[ii];
+    int nByte = sqlite3Fts5IndexCharlenToBytelen(pToken, nToken, nChar);
+    if( nByte ){
+      rc = sqlite3Fts5TermsetAdd(pTermset, ii+1, pToken, nByte, &bPresent);
+      if( bPresent==0 ){
+        pCtx->cksum ^= sqlite3Fts5IndexEntryCksum(
+            pCtx->iRowid, iCol, iPos, ii+1, pToken, nByte
+        );
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Check that the contents of the FTS index match that of the %_content
+** table. Return SQLITE_OK if they do, or SQLITE_CORRUPT if not. Return
+** some other SQLite error code if an error occurs while attempting to
+** determine this.
+*/
+static int sqlite3Fts5StorageIntegrity(Fts5Storage *p){
+  Fts5Config *pConfig = p->pConfig;
+  int rc;                         /* Return code */
+  int *aColSize;                  /* Array of size pConfig->nCol */
+  i64 *aTotalSize;                /* Array of size pConfig->nCol */
+  Fts5IntegrityCtx ctx;
+  sqlite3_stmt *pScan;
+
+  memset(&ctx, 0, sizeof(Fts5IntegrityCtx));
+  ctx.pConfig = p->pConfig;
+  aTotalSize = (i64*)sqlite3_malloc(pConfig->nCol * (sizeof(int)+sizeof(i64)));
+  if( !aTotalSize ) return SQLITE_NOMEM;
+  aColSize = (int*)&aTotalSize[pConfig->nCol];
+  memset(aTotalSize, 0, sizeof(i64) * pConfig->nCol);
+
+  /* Generate the expected index checksum based on the contents of the
+  ** %_content table. This block stores the checksum in ctx.cksum. */
+  rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);
+  if( rc==SQLITE_OK ){
+    int rc2;
+    while( SQLITE_ROW==sqlite3_step(pScan) ){
+      int i;
+      ctx.iRowid = sqlite3_column_int64(pScan, 0);
+      ctx.szCol = 0;
+      if( pConfig->bColumnsize ){
+        rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);
+      }
+      if( rc==SQLITE_OK && pConfig->eDetail==FTS5_DETAIL_NONE ){
+        rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
+      }
+      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
+        if( pConfig->abUnindexed[i] ) continue;
+        ctx.iCol = i;
+        ctx.szCol = 0;
+        if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+          rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
+        }
+        if( rc==SQLITE_OK ){
+          rc = sqlite3Fts5Tokenize(pConfig, 
+              FTS5_TOKENIZE_DOCUMENT,
+              (const char*)sqlite3_column_text(pScan, i+1),
+              sqlite3_column_bytes(pScan, i+1),
+              (void*)&ctx,
+              fts5StorageIntegrityCallback
+          );
+        }
+        if( rc==SQLITE_OK && pConfig->bColumnsize && ctx.szCol!=aColSize[i] ){
+          rc = FTS5_CORRUPT;
+        }
+        aTotalSize[i] += ctx.szCol;
+        if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+          sqlite3Fts5TermsetFree(ctx.pTermset);
+          ctx.pTermset = 0;
+        }
+      }
+      sqlite3Fts5TermsetFree(ctx.pTermset);
+      ctx.pTermset = 0;
+
+      if( rc!=SQLITE_OK ) break;
+    }
+    rc2 = sqlite3_reset(pScan);
+    if( rc==SQLITE_OK ) rc = rc2;
+  }
+
+  /* Test that the "totals" (sometimes called "averages") record looks Ok */
+  if( rc==SQLITE_OK ){
+    int i;
+    rc = fts5StorageLoadTotals(p, 0);
+    for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
+      if( p->aTotalSize[i]!=aTotalSize[i] ) rc = FTS5_CORRUPT;
+    }
+  }
+
+  /* Check that the %_docsize and %_content tables contain the expected
+  ** number of rows.  */
+  if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){
+    i64 nRow = 0;
+    rc = fts5StorageCount(p, "content", &nRow);
+    if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
+  }
+  if( rc==SQLITE_OK && pConfig->bColumnsize ){
+    i64 nRow = 0;
+    rc = fts5StorageCount(p, "docsize", &nRow);
+    if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
+  }
+
+  /* Pass the expected checksum down to the FTS index module. It will
+  ** verify, amongst other things, that it matches the checksum generated by
+  ** inspecting the index itself.  */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexIntegrityCheck(p->pIndex, ctx.cksum);
+  }
+
+  sqlite3_free(aTotalSize);
+  return rc;
+}
+
+/*
+** Obtain an SQLite statement handle that may be used to read data from the
+** %_content table.
+*/
+static int sqlite3Fts5StorageStmt(
+  Fts5Storage *p, 
+  int eStmt, 
+  sqlite3_stmt **pp, 
+  char **pzErrMsg
+){
+  int rc;
+  assert( eStmt==FTS5_STMT_SCAN_ASC 
+       || eStmt==FTS5_STMT_SCAN_DESC
+       || eStmt==FTS5_STMT_LOOKUP
+  );
+  rc = fts5StorageGetStmt(p, eStmt, pp, pzErrMsg);
+  if( rc==SQLITE_OK ){
+    assert( p->aStmt[eStmt]==*pp );
+    p->aStmt[eStmt] = 0;
+  }
+  return rc;
+}
+
+/*
+** Release an SQLite statement handle obtained via an earlier call to
+** sqlite3Fts5StorageStmt(). The eStmt parameter passed to this function
+** must match that passed to the sqlite3Fts5StorageStmt() call.
+*/
+static void sqlite3Fts5StorageStmtRelease(
+  Fts5Storage *p, 
+  int eStmt, 
+  sqlite3_stmt *pStmt
+){
+  assert( eStmt==FTS5_STMT_SCAN_ASC
+       || eStmt==FTS5_STMT_SCAN_DESC
+       || eStmt==FTS5_STMT_LOOKUP
+  );
+  if( p->aStmt[eStmt]==0 ){
+    sqlite3_reset(pStmt);
+    p->aStmt[eStmt] = pStmt;
+  }else{
+    sqlite3_finalize(pStmt);
+  }
+}
+
+static int fts5StorageDecodeSizeArray(
+  int *aCol, int nCol,            /* Array to populate */
+  const u8 *aBlob, int nBlob      /* Record to read varints from */
+){
+  int i;
+  int iOff = 0;
+  for(i=0; i<nCol; i++){
+    if( iOff>=nBlob ) return 1;
+    iOff += fts5GetVarint32(&aBlob[iOff], aCol[i]);
+  }
+  return (iOff!=nBlob);
+}
+
+/*
+** Argument aCol points to an array of integers containing one entry for
+** each table column. This function reads the %_docsize record for the
+** specified rowid and populates aCol[] with the results.
+**
+** An SQLite error code is returned if an error occurs, or SQLITE_OK
+** otherwise.
+*/
+static int sqlite3Fts5StorageDocsize(Fts5Storage *p, i64 iRowid, int *aCol){
+  int nCol = p->pConfig->nCol;    /* Number of user columns in table */
+  sqlite3_stmt *pLookup = 0;      /* Statement to query %_docsize */
+  int rc;                         /* Return Code */
+
+  assert( p->pConfig->bColumnsize );
+  rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP_DOCSIZE, &pLookup, 0);
+  if( rc==SQLITE_OK ){
+    int bCorrupt = 1;
+    sqlite3_bind_int64(pLookup, 1, iRowid);
+    if( SQLITE_ROW==sqlite3_step(pLookup) ){
+      const u8 *aBlob = sqlite3_column_blob(pLookup, 0);
+      int nBlob = sqlite3_column_bytes(pLookup, 0);
+      if( 0==fts5StorageDecodeSizeArray(aCol, nCol, aBlob, nBlob) ){
+        bCorrupt = 0;
+      }
+    }
+    rc = sqlite3_reset(pLookup);
+    if( bCorrupt && rc==SQLITE_OK ){
+      rc = FTS5_CORRUPT;
+    }
+  }
+
+  return rc;
+}
+
+static int sqlite3Fts5StorageSize(Fts5Storage *p, int iCol, i64 *pnToken){
+  int rc = fts5StorageLoadTotals(p, 0);
+  if( rc==SQLITE_OK ){
+    *pnToken = 0;
+    if( iCol<0 ){
+      int i;
+      for(i=0; i<p->pConfig->nCol; i++){
+        *pnToken += p->aTotalSize[i];
+      }
+    }else if( iCol<p->pConfig->nCol ){
+      *pnToken = p->aTotalSize[iCol];
+    }else{
+      rc = SQLITE_RANGE;
+    }
+  }
+  return rc;
+}
+
+static int sqlite3Fts5StorageRowCount(Fts5Storage *p, i64 *pnRow){
+  int rc = fts5StorageLoadTotals(p, 0);
+  if( rc==SQLITE_OK ){
+    *pnRow = p->nTotalRow;
+  }
+  return rc;
+}
+
+/*
+** Flush any data currently held in-memory to disk.
+*/
+static int sqlite3Fts5StorageSync(Fts5Storage *p, int bCommit){
+  if( bCommit && p->bTotalsValid ){
+    int rc = fts5StorageSaveTotals(p);
+    p->bTotalsValid = 0;
+    if( rc!=SQLITE_OK ) return rc;
+  }
+  return sqlite3Fts5IndexSync(p->pIndex, bCommit);
+}
+
+static int sqlite3Fts5StorageRollback(Fts5Storage *p){
+  p->bTotalsValid = 0;
+  return sqlite3Fts5IndexRollback(p->pIndex);
+}
+
+static int sqlite3Fts5StorageConfigValue(
+  Fts5Storage *p, 
+  const char *z,
+  sqlite3_value *pVal,
+  int iVal
+){
+  sqlite3_stmt *pReplace = 0;
+  int rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_CONFIG, &pReplace, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_text(pReplace, 1, z, -1, SQLITE_STATIC);
+    if( pVal ){
+      sqlite3_bind_value(pReplace, 2, pVal);
+    }else{
+      sqlite3_bind_int(pReplace, 2, iVal);
+    }
+    sqlite3_step(pReplace);
+    rc = sqlite3_reset(pReplace);
+  }
+  if( rc==SQLITE_OK && pVal ){
+    int iNew = p->pConfig->iCookie + 1;
+    rc = sqlite3Fts5IndexSetCookie(p->pIndex, iNew);
+    if( rc==SQLITE_OK ){
+      p->pConfig->iCookie = iNew;
+    }
+  }
+  return rc;
+}
+
+/*
+** 2014 May 31
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+
+/* #include "fts5Int.h" */
+
+/**************************************************************************
+** Start of ascii tokenizer implementation.
+*/
+
+/*
+** For tokenizers with no "unicode" modifier, the set of token characters
+** is the same as the set of ASCII range alphanumeric characters. 
+*/
+static unsigned char aAsciiTokenChar[128] = {
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x00..0x0F */
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x10..0x1F */
+  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x20..0x2F */
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 0, 0, 0, 0, 0, 0,   /* 0x30..0x3F */
+  0, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   /* 0x40..0x4F */
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 0, 0,   /* 0x50..0x5F */
+  0, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   /* 0x60..0x6F */
+  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 0, 0,   /* 0x70..0x7F */
+};
+
+typedef struct AsciiTokenizer AsciiTokenizer;
+struct AsciiTokenizer {
+  unsigned char aTokenChar[128];
+};
+
+static void fts5AsciiAddExceptions(
+  AsciiTokenizer *p, 
+  const char *zArg, 
+  int bTokenChars
+){
+  int i;
+  for(i=0; zArg[i]; i++){
+    if( (zArg[i] & 0x80)==0 ){
+      p->aTokenChar[(int)zArg[i]] = (unsigned char)bTokenChars;
+    }
+  }
+}
+
+/*
+** Delete a "ascii" tokenizer.
+*/
+static void fts5AsciiDelete(Fts5Tokenizer *p){
+  sqlite3_free(p);
+}
+
+/*
+** Create an "ascii" tokenizer.
+*/
+static int fts5AsciiCreate(
+  void *pUnused, 
+  const char **azArg, int nArg,
+  Fts5Tokenizer **ppOut
+){
+  int rc = SQLITE_OK;
+  AsciiTokenizer *p = 0;
+  UNUSED_PARAM(pUnused);
+  if( nArg%2 ){
+    rc = SQLITE_ERROR;
+  }else{
+    p = sqlite3_malloc(sizeof(AsciiTokenizer));
+    if( p==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      int i;
+      memset(p, 0, sizeof(AsciiTokenizer));
+      memcpy(p->aTokenChar, aAsciiTokenChar, sizeof(aAsciiTokenChar));
+      for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+        const char *zArg = azArg[i+1];
+        if( 0==sqlite3_stricmp(azArg[i], "tokenchars") ){
+          fts5AsciiAddExceptions(p, zArg, 1);
+        }else
+        if( 0==sqlite3_stricmp(azArg[i], "separators") ){
+          fts5AsciiAddExceptions(p, zArg, 0);
+        }else{
+          rc = SQLITE_ERROR;
+        }
+      }
+      if( rc!=SQLITE_OK ){
+        fts5AsciiDelete((Fts5Tokenizer*)p);
+        p = 0;
+      }
+    }
+  }
+
+  *ppOut = (Fts5Tokenizer*)p;
+  return rc;
+}
+
+
+static void asciiFold(char *aOut, const char *aIn, int nByte){
+  int i;
+  for(i=0; i<nByte; i++){
+    char c = aIn[i];
+    if( c>='A' && c<='Z' ) c += 32;
+    aOut[i] = c;
+  }
+}
+
+/*
+** Tokenize some text using the ascii tokenizer.
+*/
+static int fts5AsciiTokenize(
+  Fts5Tokenizer *pTokenizer,
+  void *pCtx,
+  int iUnused,
+  const char *pText, int nText,
+  int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)
+){
+  AsciiTokenizer *p = (AsciiTokenizer*)pTokenizer;
+  int rc = SQLITE_OK;
+  int ie;
+  int is = 0;
+
+  char aFold[64];
+  int nFold = sizeof(aFold);
+  char *pFold = aFold;
+  unsigned char *a = p->aTokenChar;
+
+  UNUSED_PARAM(iUnused);
+
+  while( is<nText && rc==SQLITE_OK ){
+    int nByte;
+
+    /* Skip any leading divider characters. */
+    while( is<nText && ((pText[is]&0x80)==0 && a[(int)pText[is]]==0) ){
+      is++;
+    }
+    if( is==nText ) break;
+
+    /* Count the token characters */
+    ie = is+1;
+    while( ie<nText && ((pText[ie]&0x80) || a[(int)pText[ie]] ) ){
+      ie++;
+    }
+
+    /* Fold to lower case */
+    nByte = ie-is;
+    if( nByte>nFold ){
+      if( pFold!=aFold ) sqlite3_free(pFold);
+      pFold = sqlite3_malloc(nByte*2);
+      if( pFold==0 ){
+        rc = SQLITE_NOMEM;
+        break;
+      }
+      nFold = nByte*2;
+    }
+    asciiFold(pFold, &pText[is], nByte);
+
+    /* Invoke the token callback */
+    rc = xToken(pCtx, 0, pFold, nByte, is, ie);
+    is = ie+1;
+  }
+  
+  if( pFold!=aFold ) sqlite3_free(pFold);
+  if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  return rc;
+}
+
+/**************************************************************************
+** Start of unicode61 tokenizer implementation.
+*/
+
+
+/*
+** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied
+** from the sqlite3 source file utf.c. If this file is compiled as part
+** of the amalgamation, they are not required.
+*/
+#ifndef SQLITE_AMALGAMATION
+
+static const unsigned char sqlite3Utf8Trans1[] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+
+#define READ_UTF8(zIn, zTerm, c)                           \
+  c = *(zIn++);                                            \
+  if( c>=0xc0 ){                                           \
+    c = sqlite3Utf8Trans1[c-0xc0];                         \
+    while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \
+      c = (c<<6) + (0x3f & *(zIn++));                      \
+    }                                                      \
+    if( c<0x80                                             \
+        || (c&0xFFFFF800)==0xD800                          \
+        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
+  }
+
+
+#define WRITE_UTF8(zOut, c) {                          \
+  if( c<0x00080 ){                                     \
+    *zOut++ = (unsigned char)(c&0xFF);                 \
+  }                                                    \
+  else if( c<0x00800 ){                                \
+    *zOut++ = 0xC0 + (unsigned char)((c>>6)&0x1F);     \
+    *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \
+  }                                                    \
+  else if( c<0x10000 ){                                \
+    *zOut++ = 0xE0 + (unsigned char)((c>>12)&0x0F);    \
+    *zOut++ = 0x80 + (unsigned char)((c>>6) & 0x3F);   \
+    *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \
+  }else{                                               \
+    *zOut++ = 0xF0 + (unsigned char)((c>>18) & 0x07);  \
+    *zOut++ = 0x80 + (unsigned char)((c>>12) & 0x3F);  \
+    *zOut++ = 0x80 + (unsigned char)((c>>6) & 0x3F);   \
+    *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \
+  }                                                    \
+}
+
+#endif /* ifndef SQLITE_AMALGAMATION */
+
+typedef struct Unicode61Tokenizer Unicode61Tokenizer;
+struct Unicode61Tokenizer {
+  unsigned char aTokenChar[128];  /* ASCII range token characters */
+  char *aFold;                    /* Buffer to fold text into */
+  int nFold;                      /* Size of aFold[] in bytes */
+  int bRemoveDiacritic;           /* True if remove_diacritics=1 is set */
+  int nException;
+  int *aiException;
+};
+
+static int fts5UnicodeAddExceptions(
+  Unicode61Tokenizer *p,          /* Tokenizer object */
+  const char *z,                  /* Characters to treat as exceptions */
+  int bTokenChars                 /* 1 for 'tokenchars', 0 for 'separators' */
+){
+  int rc = SQLITE_OK;
+  int n = (int)strlen(z);
+  int *aNew;
+
+  if( n>0 ){
+    aNew = (int*)sqlite3_realloc(p->aiException, (n+p->nException)*sizeof(int));
+    if( aNew ){
+      int nNew = p->nException;
+      const unsigned char *zCsr = (const unsigned char*)z;
+      const unsigned char *zTerm = (const unsigned char*)&z[n];
+      while( zCsr<zTerm ){
+        int iCode;
+        int bToken;
+        READ_UTF8(zCsr, zTerm, iCode);
+        if( iCode<128 ){
+          p->aTokenChar[iCode] = (unsigned char)bTokenChars;
+        }else{
+          bToken = sqlite3Fts5UnicodeIsalnum(iCode);
+          assert( (bToken==0 || bToken==1) ); 
+          assert( (bTokenChars==0 || bTokenChars==1) );
+          if( bToken!=bTokenChars && sqlite3Fts5UnicodeIsdiacritic(iCode)==0 ){
+            int i;
+            for(i=0; i<nNew; i++){
+              if( aNew[i]>iCode ) break;
+            }
+            memmove(&aNew[i+1], &aNew[i], (nNew-i)*sizeof(int));
+            aNew[i] = iCode;
+            nNew++;
+          }
+        }
+      }
+      p->aiException = aNew;
+      p->nException = nNew;
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Return true if the p->aiException[] array contains the value iCode.
+*/
+static int fts5UnicodeIsException(Unicode61Tokenizer *p, int iCode){
+  if( p->nException>0 ){
+    int *a = p->aiException;
+    int iLo = 0;
+    int iHi = p->nException-1;
+
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( iCode==a[iTest] ){
+        return 1;
+      }else if( iCode>a[iTest] ){
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+  }
+
+  return 0;
+}
+
+/*
+** Delete a "unicode61" tokenizer.
+*/
+static void fts5UnicodeDelete(Fts5Tokenizer *pTok){
+  if( pTok ){
+    Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTok;
+    sqlite3_free(p->aiException);
+    sqlite3_free(p->aFold);
+    sqlite3_free(p);
+  }
+  return;
+}
+
+/*
+** Create a "unicode61" tokenizer.
+*/
+static int fts5UnicodeCreate(
+  void *pUnused, 
+  const char **azArg, int nArg,
+  Fts5Tokenizer **ppOut
+){
+  int rc = SQLITE_OK;             /* Return code */
+  Unicode61Tokenizer *p = 0;      /* New tokenizer object */ 
+
+  UNUSED_PARAM(pUnused);
+
+  if( nArg%2 ){
+    rc = SQLITE_ERROR;
+  }else{
+    p = (Unicode61Tokenizer*)sqlite3_malloc(sizeof(Unicode61Tokenizer));
+    if( p ){
+      int i;
+      memset(p, 0, sizeof(Unicode61Tokenizer));
+      memcpy(p->aTokenChar, aAsciiTokenChar, sizeof(aAsciiTokenChar));
+      p->bRemoveDiacritic = 1;
+      p->nFold = 64;
+      p->aFold = sqlite3_malloc(p->nFold * sizeof(char));
+      if( p->aFold==0 ){
+        rc = SQLITE_NOMEM;
+      }
+      for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+        const char *zArg = azArg[i+1];
+        if( 0==sqlite3_stricmp(azArg[i], "remove_diacritics") ){
+          if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1] ){
+            rc = SQLITE_ERROR;
+          }
+          p->bRemoveDiacritic = (zArg[0]=='1');
+        }else
+        if( 0==sqlite3_stricmp(azArg[i], "tokenchars") ){
+          rc = fts5UnicodeAddExceptions(p, zArg, 1);
+        }else
+        if( 0==sqlite3_stricmp(azArg[i], "separators") ){
+          rc = fts5UnicodeAddExceptions(p, zArg, 0);
+        }else{
+          rc = SQLITE_ERROR;
+        }
+      }
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+    if( rc!=SQLITE_OK ){
+      fts5UnicodeDelete((Fts5Tokenizer*)p);
+      p = 0;
+    }
+    *ppOut = (Fts5Tokenizer*)p;
+  }
+  return rc;
+}
+
+/*
+** Return true if, for the purposes of tokenizing with the tokenizer
+** passed as the first argument, codepoint iCode is considered a token 
+** character (not a separator).
+*/
+static int fts5UnicodeIsAlnum(Unicode61Tokenizer *p, int iCode){
+  assert( (sqlite3Fts5UnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
+  return sqlite3Fts5UnicodeIsalnum(iCode) ^ fts5UnicodeIsException(p, iCode);
+}
+
+static int fts5UnicodeTokenize(
+  Fts5Tokenizer *pTokenizer,
+  void *pCtx,
+  int iUnused,
+  const char *pText, int nText,
+  int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)
+){
+  Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTokenizer;
+  int rc = SQLITE_OK;
+  unsigned char *a = p->aTokenChar;
+
+  unsigned char *zTerm = (unsigned char*)&pText[nText];
+  unsigned char *zCsr = (unsigned char *)pText;
+
+  /* Output buffer */
+  char *aFold = p->aFold;
+  int nFold = p->nFold;
+  const char *pEnd = &aFold[nFold-6];
+
+  UNUSED_PARAM(iUnused);
+
+  /* Each iteration of this loop gobbles up a contiguous run of separators,
+  ** then the next token.  */
+  while( rc==SQLITE_OK ){
+    int iCode;                    /* non-ASCII codepoint read from input */
+    char *zOut = aFold;
+    int is;
+    int ie;
+
+    /* Skip any separator characters. */
+    while( 1 ){
+      if( zCsr>=zTerm ) goto tokenize_done;
+      if( *zCsr & 0x80 ) {
+        /* A character outside of the ascii range. Skip past it if it is
+        ** a separator character. Or break out of the loop if it is not. */
+        is = zCsr - (unsigned char*)pText;
+        READ_UTF8(zCsr, zTerm, iCode);
+        if( fts5UnicodeIsAlnum(p, iCode) ){
+          goto non_ascii_tokenchar;
+        }
+      }else{
+        if( a[*zCsr] ){
+          is = zCsr - (unsigned char*)pText;
+          goto ascii_tokenchar;
+        }
+        zCsr++;
+      }
+    }
+
+    /* Run through the tokenchars. Fold them into the output buffer along
+    ** the way.  */
+    while( zCsr<zTerm ){
+
+      /* Grow the output buffer so that there is sufficient space to fit the
+      ** largest possible utf-8 character.  */
+      if( zOut>pEnd ){
+        aFold = sqlite3_malloc(nFold*2);
+        if( aFold==0 ){
+          rc = SQLITE_NOMEM;
+          goto tokenize_done;
+        }
+        zOut = &aFold[zOut - p->aFold];
+        memcpy(aFold, p->aFold, nFold);
+        sqlite3_free(p->aFold);
+        p->aFold = aFold;
+        p->nFold = nFold = nFold*2;
+        pEnd = &aFold[nFold-6];
+      }
+
+      if( *zCsr & 0x80 ){
+        /* An non-ascii-range character. Fold it into the output buffer if
+        ** it is a token character, or break out of the loop if it is not. */
+        READ_UTF8(zCsr, zTerm, iCode);
+        if( fts5UnicodeIsAlnum(p,iCode)||sqlite3Fts5UnicodeIsdiacritic(iCode) ){
+ non_ascii_tokenchar:
+          iCode = sqlite3Fts5UnicodeFold(iCode, p->bRemoveDiacritic);
+          if( iCode ) WRITE_UTF8(zOut, iCode);
+        }else{
+          break;
+        }
+      }else if( a[*zCsr]==0 ){
+        /* An ascii-range separator character. End of token. */
+        break; 
+      }else{
+ ascii_tokenchar:
+        if( *zCsr>='A' && *zCsr<='Z' ){
+          *zOut++ = *zCsr + 32;
+        }else{
+          *zOut++ = *zCsr;
+        }
+        zCsr++;
+      }
+      ie = zCsr - (unsigned char*)pText;
+    }
+
+    /* Invoke the token callback */
+    rc = xToken(pCtx, 0, aFold, zOut-aFold, is, ie); 
+  }
+  
+ tokenize_done:
+  if( rc==SQLITE_DONE ) rc = SQLITE_OK;
+  return rc;
+}
+
+/**************************************************************************
+** Start of porter stemmer implementation.
+*/
+
+/* Any tokens larger than this (in bytes) are passed through without
+** stemming. */
+#define FTS5_PORTER_MAX_TOKEN 64
+
+typedef struct PorterTokenizer PorterTokenizer;
+struct PorterTokenizer {
+  fts5_tokenizer tokenizer;       /* Parent tokenizer module */
+  Fts5Tokenizer *pTokenizer;      /* Parent tokenizer instance */
+  char aBuf[FTS5_PORTER_MAX_TOKEN + 64];
+};
+
+/*
+** Delete a "porter" tokenizer.
+*/
+static void fts5PorterDelete(Fts5Tokenizer *pTok){
+  if( pTok ){
+    PorterTokenizer *p = (PorterTokenizer*)pTok;
+    if( p->pTokenizer ){
+      p->tokenizer.xDelete(p->pTokenizer);
+    }
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Create a "porter" tokenizer.
+*/
+static int fts5PorterCreate(
+  void *pCtx, 
+  const char **azArg, int nArg,
+  Fts5Tokenizer **ppOut
+){
+  fts5_api *pApi = (fts5_api*)pCtx;
+  int rc = SQLITE_OK;
+  PorterTokenizer *pRet;
+  void *pUserdata = 0;
+  const char *zBase = "unicode61";
+
+  if( nArg>0 ){
+    zBase = azArg[0];
+  }
+
+  pRet = (PorterTokenizer*)sqlite3_malloc(sizeof(PorterTokenizer));
+  if( pRet ){
+    memset(pRet, 0, sizeof(PorterTokenizer));
+    rc = pApi->xFindTokenizer(pApi, zBase, &pUserdata, &pRet->tokenizer);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  if( rc==SQLITE_OK ){
+    int nArg2 = (nArg>0 ? nArg-1 : 0);
+    const char **azArg2 = (nArg2 ? &azArg[1] : 0);
+    rc = pRet->tokenizer.xCreate(pUserdata, azArg2, nArg2, &pRet->pTokenizer);
+  }
+
+  if( rc!=SQLITE_OK ){
+    fts5PorterDelete((Fts5Tokenizer*)pRet);
+    pRet = 0;
+  }
+  *ppOut = (Fts5Tokenizer*)pRet;
+  return rc;
+}
+
+typedef struct PorterContext PorterContext;
+struct PorterContext {
+  void *pCtx;
+  int (*xToken)(void*, int, const char*, int, int, int);
+  char *aBuf;
+};
+
+typedef struct PorterRule PorterRule;
+struct PorterRule {
+  const char *zSuffix;
+  int nSuffix;
+  int (*xCond)(char *zStem, int nStem);
+  const char *zOutput;
+  int nOutput;
+};
+
+#if 0
+static int fts5PorterApply(char *aBuf, int *pnBuf, PorterRule *aRule){
+  int ret = -1;
+  int nBuf = *pnBuf;
+  PorterRule *p;
+
+  for(p=aRule; p->zSuffix; p++){
+    assert( strlen(p->zSuffix)==p->nSuffix );
+    assert( strlen(p->zOutput)==p->nOutput );
+    if( nBuf<p->nSuffix ) continue;
+    if( 0==memcmp(&aBuf[nBuf - p->nSuffix], p->zSuffix, p->nSuffix) ) break;
+  }
+
+  if( p->zSuffix ){
+    int nStem = nBuf - p->nSuffix;
+    if( p->xCond==0 || p->xCond(aBuf, nStem) ){
+      memcpy(&aBuf[nStem], p->zOutput, p->nOutput);
+      *pnBuf = nStem + p->nOutput;
+      ret = p - aRule;
+    }
+  }
+
+  return ret;
+}
+#endif
+
+static int fts5PorterIsVowel(char c, int bYIsVowel){
+  return (
+      c=='a' || c=='e' || c=='i' || c=='o' || c=='u' || (bYIsVowel && c=='y')
+  );
+}
+
+static int fts5PorterGobbleVC(char *zStem, int nStem, int bPrevCons){
+  int i;
+  int bCons = bPrevCons;
+
+  /* Scan for a vowel */
+  for(i=0; i<nStem; i++){
+    if( 0==(bCons = !fts5PorterIsVowel(zStem[i], bCons)) ) break;
+  }
+
+  /* Scan for a consonent */
+  for(i++; i<nStem; i++){
+    if( (bCons = !fts5PorterIsVowel(zStem[i], bCons)) ) return i+1;
+  }
+  return 0;
+}
+
+/* porter rule condition: (m > 0) */
+static int fts5Porter_MGt0(char *zStem, int nStem){
+  return !!fts5PorterGobbleVC(zStem, nStem, 0);
+}
+
+/* porter rule condition: (m > 1) */
+static int fts5Porter_MGt1(char *zStem, int nStem){
+  int n;
+  n = fts5PorterGobbleVC(zStem, nStem, 0);
+  if( n && fts5PorterGobbleVC(&zStem[n], nStem-n, 1) ){
+    return 1;
+  }
+  return 0;
+}
+
+/* porter rule condition: (m = 1) */
+static int fts5Porter_MEq1(char *zStem, int nStem){
+  int n;
+  n = fts5PorterGobbleVC(zStem, nStem, 0);
+  if( n && 0==fts5PorterGobbleVC(&zStem[n], nStem-n, 1) ){
+    return 1;
+  }
+  return 0;
+}
+
+/* porter rule condition: (*o) */
+static int fts5Porter_Ostar(char *zStem, int nStem){
+  if( zStem[nStem-1]=='w' || zStem[nStem-1]=='x' || zStem[nStem-1]=='y' ){
+    return 0;
+  }else{
+    int i;
+    int mask = 0;
+    int bCons = 0;
+    for(i=0; i<nStem; i++){
+      bCons = !fts5PorterIsVowel(zStem[i], bCons);
+      assert( bCons==0 || bCons==1 );
+      mask = (mask << 1) + bCons;
+    }
+    return ((mask & 0x0007)==0x0005);
+  }
+}
+
+/* porter rule condition: (m > 1 and (*S or *T)) */
+static int fts5Porter_MGt1_and_S_or_T(char *zStem, int nStem){
+  assert( nStem>0 );
+  return (zStem[nStem-1]=='s' || zStem[nStem-1]=='t') 
+      && fts5Porter_MGt1(zStem, nStem);
+}
+
+/* porter rule condition: (*v*) */
+static int fts5Porter_Vowel(char *zStem, int nStem){
+  int i;
+  for(i=0; i<nStem; i++){
+    if( fts5PorterIsVowel(zStem[i], i>0) ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+/**************************************************************************
+***************************************************************************
+** GENERATED CODE STARTS HERE (mkportersteps.tcl)
+*/
+
+static int fts5PorterStep4(char *aBuf, int *pnBuf){
+  int ret = 0;
+  int nBuf = *pnBuf;
+  switch( aBuf[nBuf-2] ){
+    
+    case 'a': 
+      if( nBuf>2 && 0==memcmp("al", &aBuf[nBuf-2], 2) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-2) ){
+          *pnBuf = nBuf - 2;
+        }
+      }
+      break;
+  
+    case 'c': 
+      if( nBuf>4 && 0==memcmp("ance", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }else if( nBuf>4 && 0==memcmp("ence", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }
+      break;
+  
+    case 'e': 
+      if( nBuf>2 && 0==memcmp("er", &aBuf[nBuf-2], 2) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-2) ){
+          *pnBuf = nBuf - 2;
+        }
+      }
+      break;
+  
+    case 'i': 
+      if( nBuf>2 && 0==memcmp("ic", &aBuf[nBuf-2], 2) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-2) ){
+          *pnBuf = nBuf - 2;
+        }
+      }
+      break;
+  
+    case 'l': 
+      if( nBuf>4 && 0==memcmp("able", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }else if( nBuf>4 && 0==memcmp("ible", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }
+      break;
+  
+    case 'n': 
+      if( nBuf>3 && 0==memcmp("ant", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }else if( nBuf>5 && 0==memcmp("ement", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-5) ){
+          *pnBuf = nBuf - 5;
+        }
+      }else if( nBuf>4 && 0==memcmp("ment", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }else if( nBuf>3 && 0==memcmp("ent", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 'o': 
+      if( nBuf>3 && 0==memcmp("ion", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1_and_S_or_T(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }else if( nBuf>2 && 0==memcmp("ou", &aBuf[nBuf-2], 2) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-2) ){
+          *pnBuf = nBuf - 2;
+        }
+      }
+      break;
+  
+    case 's': 
+      if( nBuf>3 && 0==memcmp("ism", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 't': 
+      if( nBuf>3 && 0==memcmp("ate", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }else if( nBuf>3 && 0==memcmp("iti", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 'u': 
+      if( nBuf>3 && 0==memcmp("ous", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 'v': 
+      if( nBuf>3 && 0==memcmp("ive", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 'z': 
+      if( nBuf>3 && 0==memcmp("ize", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt1(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+  }
+  return ret;
+}
+  
+
+static int fts5PorterStep1B2(char *aBuf, int *pnBuf){
+  int ret = 0;
+  int nBuf = *pnBuf;
+  switch( aBuf[nBuf-2] ){
+    
+    case 'a': 
+      if( nBuf>2 && 0==memcmp("at", &aBuf[nBuf-2], 2) ){
+        memcpy(&aBuf[nBuf-2], "ate", 3);
+        *pnBuf = nBuf - 2 + 3;
+        ret = 1;
+      }
+      break;
+  
+    case 'b': 
+      if( nBuf>2 && 0==memcmp("bl", &aBuf[nBuf-2], 2) ){
+        memcpy(&aBuf[nBuf-2], "ble", 3);
+        *pnBuf = nBuf - 2 + 3;
+        ret = 1;
+      }
+      break;
+  
+    case 'i': 
+      if( nBuf>2 && 0==memcmp("iz", &aBuf[nBuf-2], 2) ){
+        memcpy(&aBuf[nBuf-2], "ize", 3);
+        *pnBuf = nBuf - 2 + 3;
+        ret = 1;
+      }
+      break;
+  
+  }
+  return ret;
+}
+  
+
+static int fts5PorterStep2(char *aBuf, int *pnBuf){
+  int ret = 0;
+  int nBuf = *pnBuf;
+  switch( aBuf[nBuf-2] ){
+    
+    case 'a': 
+      if( nBuf>7 && 0==memcmp("ational", &aBuf[nBuf-7], 7) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-7) ){
+          memcpy(&aBuf[nBuf-7], "ate", 3);
+          *pnBuf = nBuf - 7 + 3;
+        }
+      }else if( nBuf>6 && 0==memcmp("tional", &aBuf[nBuf-6], 6) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-6) ){
+          memcpy(&aBuf[nBuf-6], "tion", 4);
+          *pnBuf = nBuf - 6 + 4;
+        }
+      }
+      break;
+  
+    case 'c': 
+      if( nBuf>4 && 0==memcmp("enci", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "ence", 4);
+          *pnBuf = nBuf - 4 + 4;
+        }
+      }else if( nBuf>4 && 0==memcmp("anci", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "ance", 4);
+          *pnBuf = nBuf - 4 + 4;
+        }
+      }
+      break;
+  
+    case 'e': 
+      if( nBuf>4 && 0==memcmp("izer", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "ize", 3);
+          *pnBuf = nBuf - 4 + 3;
+        }
+      }
+      break;
+  
+    case 'g': 
+      if( nBuf>4 && 0==memcmp("logi", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "log", 3);
+          *pnBuf = nBuf - 4 + 3;
+        }
+      }
+      break;
+  
+    case 'l': 
+      if( nBuf>3 && 0==memcmp("bli", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-3) ){
+          memcpy(&aBuf[nBuf-3], "ble", 3);
+          *pnBuf = nBuf - 3 + 3;
+        }
+      }else if( nBuf>4 && 0==memcmp("alli", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "al", 2);
+          *pnBuf = nBuf - 4 + 2;
+        }
+      }else if( nBuf>5 && 0==memcmp("entli", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ent", 3);
+          *pnBuf = nBuf - 5 + 3;
+        }
+      }else if( nBuf>3 && 0==memcmp("eli", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-3) ){
+          memcpy(&aBuf[nBuf-3], "e", 1);
+          *pnBuf = nBuf - 3 + 1;
+        }
+      }else if( nBuf>5 && 0==memcmp("ousli", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ous", 3);
+          *pnBuf = nBuf - 5 + 3;
+        }
+      }
+      break;
+  
+    case 'o': 
+      if( nBuf>7 && 0==memcmp("ization", &aBuf[nBuf-7], 7) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-7) ){
+          memcpy(&aBuf[nBuf-7], "ize", 3);
+          *pnBuf = nBuf - 7 + 3;
+        }
+      }else if( nBuf>5 && 0==memcmp("ation", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ate", 3);
+          *pnBuf = nBuf - 5 + 3;
+        }
+      }else if( nBuf>4 && 0==memcmp("ator", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "ate", 3);
+          *pnBuf = nBuf - 4 + 3;
+        }
+      }
+      break;
+  
+    case 's': 
+      if( nBuf>5 && 0==memcmp("alism", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "al", 2);
+          *pnBuf = nBuf - 5 + 2;
+        }
+      }else if( nBuf>7 && 0==memcmp("iveness", &aBuf[nBuf-7], 7) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-7) ){
+          memcpy(&aBuf[nBuf-7], "ive", 3);
+          *pnBuf = nBuf - 7 + 3;
+        }
+      }else if( nBuf>7 && 0==memcmp("fulness", &aBuf[nBuf-7], 7) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-7) ){
+          memcpy(&aBuf[nBuf-7], "ful", 3);
+          *pnBuf = nBuf - 7 + 3;
+        }
+      }else if( nBuf>7 && 0==memcmp("ousness", &aBuf[nBuf-7], 7) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-7) ){
+          memcpy(&aBuf[nBuf-7], "ous", 3);
+          *pnBuf = nBuf - 7 + 3;
+        }
+      }
+      break;
+  
+    case 't': 
+      if( nBuf>5 && 0==memcmp("aliti", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "al", 2);
+          *pnBuf = nBuf - 5 + 2;
+        }
+      }else if( nBuf>5 && 0==memcmp("iviti", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ive", 3);
+          *pnBuf = nBuf - 5 + 3;
+        }
+      }else if( nBuf>6 && 0==memcmp("biliti", &aBuf[nBuf-6], 6) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-6) ){
+          memcpy(&aBuf[nBuf-6], "ble", 3);
+          *pnBuf = nBuf - 6 + 3;
+        }
+      }
+      break;
+  
+  }
+  return ret;
+}
+  
+
+static int fts5PorterStep3(char *aBuf, int *pnBuf){
+  int ret = 0;
+  int nBuf = *pnBuf;
+  switch( aBuf[nBuf-2] ){
+    
+    case 'a': 
+      if( nBuf>4 && 0==memcmp("ical", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          memcpy(&aBuf[nBuf-4], "ic", 2);
+          *pnBuf = nBuf - 4 + 2;
+        }
+      }
+      break;
+  
+    case 's': 
+      if( nBuf>4 && 0==memcmp("ness", &aBuf[nBuf-4], 4) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-4) ){
+          *pnBuf = nBuf - 4;
+        }
+      }
+      break;
+  
+    case 't': 
+      if( nBuf>5 && 0==memcmp("icate", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ic", 2);
+          *pnBuf = nBuf - 5 + 2;
+        }
+      }else if( nBuf>5 && 0==memcmp("iciti", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "ic", 2);
+          *pnBuf = nBuf - 5 + 2;
+        }
+      }
+      break;
+  
+    case 'u': 
+      if( nBuf>3 && 0==memcmp("ful", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+        }
+      }
+      break;
+  
+    case 'v': 
+      if( nBuf>5 && 0==memcmp("ative", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          *pnBuf = nBuf - 5;
+        }
+      }
+      break;
+  
+    case 'z': 
+      if( nBuf>5 && 0==memcmp("alize", &aBuf[nBuf-5], 5) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-5) ){
+          memcpy(&aBuf[nBuf-5], "al", 2);
+          *pnBuf = nBuf - 5 + 2;
+        }
+      }
+      break;
+  
+  }
+  return ret;
+}
+  
+
+static int fts5PorterStep1B(char *aBuf, int *pnBuf){
+  int ret = 0;
+  int nBuf = *pnBuf;
+  switch( aBuf[nBuf-2] ){
+    
+    case 'e': 
+      if( nBuf>3 && 0==memcmp("eed", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_MGt0(aBuf, nBuf-3) ){
+          memcpy(&aBuf[nBuf-3], "ee", 2);
+          *pnBuf = nBuf - 3 + 2;
+        }
+      }else if( nBuf>2 && 0==memcmp("ed", &aBuf[nBuf-2], 2) ){
+        if( fts5Porter_Vowel(aBuf, nBuf-2) ){
+          *pnBuf = nBuf - 2;
+          ret = 1;
+        }
+      }
+      break;
+  
+    case 'n': 
+      if( nBuf>3 && 0==memcmp("ing", &aBuf[nBuf-3], 3) ){
+        if( fts5Porter_Vowel(aBuf, nBuf-3) ){
+          *pnBuf = nBuf - 3;
+          ret = 1;
+        }
+      }
+      break;
+  
+  }
+  return ret;
+}
+  
+/* 
+** GENERATED CODE ENDS HERE (mkportersteps.tcl)
+***************************************************************************
+**************************************************************************/
+
+static void fts5PorterStep1A(char *aBuf, int *pnBuf){
+  int nBuf = *pnBuf;
+  if( aBuf[nBuf-1]=='s' ){
+    if( aBuf[nBuf-2]=='e' ){
+      if( (nBuf>4 && aBuf[nBuf-4]=='s' && aBuf[nBuf-3]=='s') 
+       || (nBuf>3 && aBuf[nBuf-3]=='i' )
+      ){
+        *pnBuf = nBuf-2;
+      }else{
+        *pnBuf = nBuf-1;
+      }
+    }
+    else if( aBuf[nBuf-2]!='s' ){
+      *pnBuf = nBuf-1;
+    }
+  }
+}
+
+static int fts5PorterCb(
+  void *pCtx, 
+  int tflags,
+  const char *pToken, 
+  int nToken, 
+  int iStart, 
+  int iEnd
+){
+  PorterContext *p = (PorterContext*)pCtx;
+
+  char *aBuf;
+  int nBuf;
+
+  if( nToken>FTS5_PORTER_MAX_TOKEN || nToken<3 ) goto pass_through;
+  aBuf = p->aBuf;
+  nBuf = nToken;
+  memcpy(aBuf, pToken, nBuf);
+
+  /* Step 1. */
+  fts5PorterStep1A(aBuf, &nBuf);
+  if( fts5PorterStep1B(aBuf, &nBuf) ){
+    if( fts5PorterStep1B2(aBuf, &nBuf)==0 ){
+      char c = aBuf[nBuf-1];
+      if( fts5PorterIsVowel(c, 0)==0 
+       && c!='l' && c!='s' && c!='z' && c==aBuf[nBuf-2] 
+      ){
+        nBuf--;
+      }else if( fts5Porter_MEq1(aBuf, nBuf) && fts5Porter_Ostar(aBuf, nBuf) ){
+        aBuf[nBuf++] = 'e';
+      }
+    }
+  }
+
+  /* Step 1C. */
+  if( aBuf[nBuf-1]=='y' && fts5Porter_Vowel(aBuf, nBuf-1) ){
+    aBuf[nBuf-1] = 'i';
+  }
+
+  /* Steps 2 through 4. */
+  fts5PorterStep2(aBuf, &nBuf);
+  fts5PorterStep3(aBuf, &nBuf);
+  fts5PorterStep4(aBuf, &nBuf);
+
+  /* Step 5a. */
+  assert( nBuf>0 );
+  if( aBuf[nBuf-1]=='e' ){
+    if( fts5Porter_MGt1(aBuf, nBuf-1) 
+     || (fts5Porter_MEq1(aBuf, nBuf-1) && !fts5Porter_Ostar(aBuf, nBuf-1))
+    ){
+      nBuf--;
+    }
+  }
+
+  /* Step 5b. */
+  if( nBuf>1 && aBuf[nBuf-1]=='l' 
+   && aBuf[nBuf-2]=='l' && fts5Porter_MGt1(aBuf, nBuf-1) 
+  ){
+    nBuf--;
+  }
+
+  return p->xToken(p->pCtx, tflags, aBuf, nBuf, iStart, iEnd);
+
+ pass_through:
+  return p->xToken(p->pCtx, tflags, pToken, nToken, iStart, iEnd);
+}
+
+/*
+** Tokenize using the porter tokenizer.
+*/
+static int fts5PorterTokenize(
+  Fts5Tokenizer *pTokenizer,
+  void *pCtx,
+  int flags,
+  const char *pText, int nText,
+  int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)
+){
+  PorterTokenizer *p = (PorterTokenizer*)pTokenizer;
+  PorterContext sCtx;
+  sCtx.xToken = xToken;
+  sCtx.pCtx = pCtx;
+  sCtx.aBuf = p->aBuf;
+  return p->tokenizer.xTokenize(
+      p->pTokenizer, (void*)&sCtx, flags, pText, nText, fts5PorterCb
+  );
+}
+
+/*
+** Register all built-in tokenizers with FTS5.
+*/
+static int sqlite3Fts5TokenizerInit(fts5_api *pApi){
+  struct BuiltinTokenizer {
+    const char *zName;
+    fts5_tokenizer x;
+  } aBuiltin[] = {
+    { "unicode61", {fts5UnicodeCreate, fts5UnicodeDelete, fts5UnicodeTokenize}},
+    { "ascii",     {fts5AsciiCreate, fts5AsciiDelete, fts5AsciiTokenize }},
+    { "porter",    {fts5PorterCreate, fts5PorterDelete, fts5PorterTokenize }},
+  };
+  
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* To iterate through builtin functions */
+
+  for(i=0; rc==SQLITE_OK && i<ArraySize(aBuiltin); i++){
+    rc = pApi->xCreateTokenizer(pApi,
+        aBuiltin[i].zName,
+        (void*)pApi,
+        &aBuiltin[i].x,
+        0
+    );
+  }
+
+  return rc;
+}
+
+
+
+/*
+** 2012 May 25
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+*/
+
+/*
+** DO NOT EDIT THIS MACHINE GENERATED FILE.
+*/
+
+
+/* #include <assert.h> */
+
+/*
+** Return true if the argument corresponds to a unicode codepoint
+** classified as either a letter or a number. Otherwise false.
+**
+** The results are undefined if the value passed to this function
+** is less than zero.
+*/
+static int sqlite3Fts5UnicodeIsalnum(int c){
+  /* Each unsigned integer in the following array corresponds to a contiguous
+  ** range of unicode codepoints that are not either letters or numbers (i.e.
+  ** codepoints for which this function should return 0).
+  **
+  ** The most significant 22 bits in each 32-bit value contain the first 
+  ** codepoint in the range. The least significant 10 bits are used to store
+  ** the size of the range (always at least 1). In other words, the value 
+  ** ((C<<22) + N) represents a range of N codepoints starting with codepoint 
+  ** C. It is not possible to represent a range larger than 1023 codepoints 
+  ** using this format.
+  */
+  static const unsigned int aEntry[] = {
+    0x00000030, 0x0000E807, 0x00016C06, 0x0001EC2F, 0x0002AC07,
+    0x0002D001, 0x0002D803, 0x0002EC01, 0x0002FC01, 0x00035C01,
+    0x0003DC01, 0x000B0804, 0x000B480E, 0x000B9407, 0x000BB401,
+    0x000BBC81, 0x000DD401, 0x000DF801, 0x000E1002, 0x000E1C01,
+    0x000FD801, 0x00120808, 0x00156806, 0x00162402, 0x00163C01,
+    0x00164437, 0x0017CC02, 0x00180005, 0x00181816, 0x00187802,
+    0x00192C15, 0x0019A804, 0x0019C001, 0x001B5001, 0x001B580F,
+    0x001B9C07, 0x001BF402, 0x001C000E, 0x001C3C01, 0x001C4401,
+    0x001CC01B, 0x001E980B, 0x001FAC09, 0x001FD804, 0x00205804,
+    0x00206C09, 0x00209403, 0x0020A405, 0x0020C00F, 0x00216403,
+    0x00217801, 0x0023901B, 0x00240004, 0x0024E803, 0x0024F812,
+    0x00254407, 0x00258804, 0x0025C001, 0x00260403, 0x0026F001,
+    0x0026F807, 0x00271C02, 0x00272C03, 0x00275C01, 0x00278802,
+    0x0027C802, 0x0027E802, 0x00280403, 0x0028F001, 0x0028F805,
+    0x00291C02, 0x00292C03, 0x00294401, 0x0029C002, 0x0029D401,
+    0x002A0403, 0x002AF001, 0x002AF808, 0x002B1C03, 0x002B2C03,
+    0x002B8802, 0x002BC002, 0x002C0403, 0x002CF001, 0x002CF807,
+    0x002D1C02, 0x002D2C03, 0x002D5802, 0x002D8802, 0x002DC001,
+    0x002E0801, 0x002EF805, 0x002F1803, 0x002F2804, 0x002F5C01,
+    0x002FCC08, 0x00300403, 0x0030F807, 0x00311803, 0x00312804,
+    0x00315402, 0x00318802, 0x0031FC01, 0x00320802, 0x0032F001,
+    0x0032F807, 0x00331803, 0x00332804, 0x00335402, 0x00338802,
+    0x00340802, 0x0034F807, 0x00351803, 0x00352804, 0x00355C01,
+    0x00358802, 0x0035E401, 0x00360802, 0x00372801, 0x00373C06,
+    0x00375801, 0x00376008, 0x0037C803, 0x0038C401, 0x0038D007,
+    0x0038FC01, 0x00391C09, 0x00396802, 0x003AC401, 0x003AD006,
+    0x003AEC02, 0x003B2006, 0x003C041F, 0x003CD00C, 0x003DC417,
+    0x003E340B, 0x003E6424, 0x003EF80F, 0x003F380D, 0x0040AC14,
+    0x00412806, 0x00415804, 0x00417803, 0x00418803, 0x00419C07,
+    0x0041C404, 0x0042080C, 0x00423C01, 0x00426806, 0x0043EC01,
+    0x004D740C, 0x004E400A, 0x00500001, 0x0059B402, 0x005A0001,
+    0x005A6C02, 0x005BAC03, 0x005C4803, 0x005CC805, 0x005D4802,
+    0x005DC802, 0x005ED023, 0x005F6004, 0x005F7401, 0x0060000F,
+    0x0062A401, 0x0064800C, 0x0064C00C, 0x00650001, 0x00651002,
+    0x0066C011, 0x00672002, 0x00677822, 0x00685C05, 0x00687802,
+    0x0069540A, 0x0069801D, 0x0069FC01, 0x006A8007, 0x006AA006,
+    0x006C0005, 0x006CD011, 0x006D6823, 0x006E0003, 0x006E840D,
+    0x006F980E, 0x006FF004, 0x00709014, 0x0070EC05, 0x0071F802,
+    0x00730008, 0x00734019, 0x0073B401, 0x0073C803, 0x00770027,
+    0x0077F004, 0x007EF401, 0x007EFC03, 0x007F3403, 0x007F7403,
+    0x007FB403, 0x007FF402, 0x00800065, 0x0081A806, 0x0081E805,
+    0x00822805, 0x0082801A, 0x00834021, 0x00840002, 0x00840C04,
+    0x00842002, 0x00845001, 0x00845803, 0x00847806, 0x00849401,
+    0x00849C01, 0x0084A401, 0x0084B801, 0x0084E802, 0x00850005,
+    0x00852804, 0x00853C01, 0x00864264, 0x00900027, 0x0091000B,
+    0x0092704E, 0x00940200, 0x009C0475, 0x009E53B9, 0x00AD400A,
+    0x00B39406, 0x00B3BC03, 0x00B3E404, 0x00B3F802, 0x00B5C001,
+    0x00B5FC01, 0x00B7804F, 0x00B8C00C, 0x00BA001A, 0x00BA6C59,
+    0x00BC00D6, 0x00BFC00C, 0x00C00005, 0x00C02019, 0x00C0A807,
+    0x00C0D802, 0x00C0F403, 0x00C26404, 0x00C28001, 0x00C3EC01,
+    0x00C64002, 0x00C6580A, 0x00C70024, 0x00C8001F, 0x00C8A81E,
+    0x00C94001, 0x00C98020, 0x00CA2827, 0x00CB003F, 0x00CC0100,
+    0x01370040, 0x02924037, 0x0293F802, 0x02983403, 0x0299BC10,
+    0x029A7C01, 0x029BC008, 0x029C0017, 0x029C8002, 0x029E2402,
+    0x02A00801, 0x02A01801, 0x02A02C01, 0x02A08C09, 0x02A0D804,
+    0x02A1D004, 0x02A20002, 0x02A2D011, 0x02A33802, 0x02A38012,
+    0x02A3E003, 0x02A4980A, 0x02A51C0D, 0x02A57C01, 0x02A60004,
+    0x02A6CC1B, 0x02A77802, 0x02A8A40E, 0x02A90C01, 0x02A93002,
+    0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,
+    0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,
+    0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,
+    0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,
+    0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,
+    0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,
+    0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,
+    0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,
+    0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,
+    0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,
+    0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,
+    0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,
+    0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,
+    0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,
+    0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,
+    0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,
+    0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,
+    0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,
+    0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,
+    0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,
+    0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,
+    0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,
+    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
+    0x380400F0,
+  };
+  static const unsigned int aAscii[4] = {
+    0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
+  };
+
+  if( (unsigned int)c<128 ){
+    return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
+  }else if( (unsigned int)c<(1<<22) ){
+    unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
+    int iRes = 0;
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      if( key >= aEntry[iTest] ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+    assert( aEntry[0]<key );
+    assert( key>=aEntry[iRes] );
+    return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
+  }
+  return 1;
+}
+
+
+/*
+** If the argument is a codepoint corresponding to a lowercase letter
+** in the ASCII range with a diacritic added, return the codepoint
+** of the ASCII letter only. For example, if passed 235 - "LATIN
+** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER
+** E"). The resuls of passing a codepoint that corresponds to an
+** uppercase letter are undefined.
+*/
+static int fts5_remove_diacritic(int c){
+  unsigned short aDia[] = {
+        0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 
+     2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 
+     2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 
+     2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 
+     3456,  3696,  3712,  3728,  3744,  3896,  3912,  3928, 
+     3968,  4008,  4040,  4106,  4138,  4170,  4202,  4234, 
+     4266,  4296,  4312,  4344,  4408,  4424,  4472,  4504, 
+     6148,  6198,  6264,  6280,  6360,  6429,  6505,  6529, 
+    61448, 61468, 61534, 61592, 61642, 61688, 61704, 61726, 
+    61784, 61800, 61836, 61880, 61914, 61948, 61998, 62122, 
+    62154, 62200, 62218, 62302, 62364, 62442, 62478, 62536, 
+    62554, 62584, 62604, 62640, 62648, 62656, 62664, 62730, 
+    62924, 63050, 63082, 63274, 63390, 
+  };
+  char aChar[] = {
+    '\0', 'a',  'c',  'e',  'i',  'n',  'o',  'u',  'y',  'y',  'a',  'c',  
+    'd',  'e',  'e',  'g',  'h',  'i',  'j',  'k',  'l',  'n',  'o',  'r',  
+    's',  't',  'u',  'u',  'w',  'y',  'z',  'o',  'u',  'a',  'i',  'o',  
+    'u',  'g',  'k',  'o',  'j',  'g',  'n',  'a',  'e',  'i',  'o',  'r',  
+    'u',  's',  't',  'h',  'a',  'e',  'o',  'y',  '\0', '\0', '\0', '\0', 
+    '\0', '\0', '\0', '\0', 'a',  'b',  'd',  'd',  'e',  'f',  'g',  'h',  
+    'h',  'i',  'k',  'l',  'l',  'm',  'n',  'p',  'r',  'r',  's',  't',  
+    'u',  'v',  'w',  'w',  'x',  'y',  'z',  'h',  't',  'w',  'y',  'a',  
+    'e',  'i',  'o',  'u',  'y',  
+  };
+
+  unsigned int key = (((unsigned int)c)<<3) | 0x00000007;
+  int iRes = 0;
+  int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;
+  int iLo = 0;
+  while( iHi>=iLo ){
+    int iTest = (iHi + iLo) / 2;
+    if( key >= aDia[iTest] ){
+      iRes = iTest;
+      iLo = iTest+1;
+    }else{
+      iHi = iTest-1;
+    }
+  }
+  assert( key>=aDia[iRes] );
+  return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);
+}
+
+
+/*
+** Return true if the argument interpreted as a unicode codepoint
+** is a diacritical modifier character.
+*/
+static int sqlite3Fts5UnicodeIsdiacritic(int c){
+  unsigned int mask0 = 0x08029FDF;
+  unsigned int mask1 = 0x000361F8;
+  if( c<768 || c>817 ) return 0;
+  return (c < 768+32) ?
+      (mask0 & (1 << (c-768))) :
+      (mask1 & (1 << (c-768-32)));
+}
+
+
+/*
+** Interpret the argument as a unicode codepoint. If the codepoint
+** is an upper case character that has a lower case equivalent,
+** return the codepoint corresponding to the lower case version.
+** Otherwise, return a copy of the argument.
+**
+** The results are undefined if the value passed to this function
+** is less than zero.
+*/
+static int sqlite3Fts5UnicodeFold(int c, int bRemoveDiacritic){
+  /* Each entry in the following array defines a rule for folding a range
+  ** of codepoints to lower case. The rule applies to a range of nRange
+  ** codepoints starting at codepoint iCode.
+  **
+  ** If the least significant bit in flags is clear, then the rule applies
+  ** to all nRange codepoints (i.e. all nRange codepoints are upper case and
+  ** need to be folded). Or, if it is set, then the rule only applies to
+  ** every second codepoint in the range, starting with codepoint C.
+  **
+  ** The 7 most significant bits in flags are an index into the aiOff[]
+  ** array. If a specific codepoint C does require folding, then its lower
+  ** case equivalent is ((C + aiOff[flags>>1]) & 0xFFFF).
+  **
+  ** The contents of this array are generated by parsing the CaseFolding.txt
+  ** file distributed as part of the "Unicode Character Database". See
+  ** http://www.unicode.org for details.
+  */
+  static const struct TableEntry {
+    unsigned short iCode;
+    unsigned char flags;
+    unsigned char nRange;
+  } aEntry[] = {
+    {65, 14, 26},          {181, 64, 1},          {192, 14, 23},
+    {216, 14, 7},          {256, 1, 48},          {306, 1, 6},
+    {313, 1, 16},          {330, 1, 46},          {376, 116, 1},
+    {377, 1, 6},           {383, 104, 1},         {385, 50, 1},
+    {386, 1, 4},           {390, 44, 1},          {391, 0, 1},
+    {393, 42, 2},          {395, 0, 1},           {398, 32, 1},
+    {399, 38, 1},          {400, 40, 1},          {401, 0, 1},
+    {403, 42, 1},          {404, 46, 1},          {406, 52, 1},
+    {407, 48, 1},          {408, 0, 1},           {412, 52, 1},
+    {413, 54, 1},          {415, 56, 1},          {416, 1, 6},
+    {422, 60, 1},          {423, 0, 1},           {425, 60, 1},
+    {428, 0, 1},           {430, 60, 1},          {431, 0, 1},
+    {433, 58, 2},          {435, 1, 4},           {439, 62, 1},
+    {440, 0, 1},           {444, 0, 1},           {452, 2, 1},
+    {453, 0, 1},           {455, 2, 1},           {456, 0, 1},
+    {458, 2, 1},           {459, 1, 18},          {478, 1, 18},
+    {497, 2, 1},           {498, 1, 4},           {502, 122, 1},
+    {503, 134, 1},         {504, 1, 40},          {544, 110, 1},
+    {546, 1, 18},          {570, 70, 1},          {571, 0, 1},
+    {573, 108, 1},         {574, 68, 1},          {577, 0, 1},
+    {579, 106, 1},         {580, 28, 1},          {581, 30, 1},
+    {582, 1, 10},          {837, 36, 1},          {880, 1, 4},
+    {886, 0, 1},           {902, 18, 1},          {904, 16, 3},
+    {908, 26, 1},          {910, 24, 2},          {913, 14, 17},
+    {931, 14, 9},          {962, 0, 1},           {975, 4, 1},
+    {976, 140, 1},         {977, 142, 1},         {981, 146, 1},
+    {982, 144, 1},         {984, 1, 24},          {1008, 136, 1},
+    {1009, 138, 1},        {1012, 130, 1},        {1013, 128, 1},
+    {1015, 0, 1},          {1017, 152, 1},        {1018, 0, 1},
+    {1021, 110, 3},        {1024, 34, 16},        {1040, 14, 32},
+    {1120, 1, 34},         {1162, 1, 54},         {1216, 6, 1},
+    {1217, 1, 14},         {1232, 1, 88},         {1329, 22, 38},
+    {4256, 66, 38},        {4295, 66, 1},         {4301, 66, 1},
+    {7680, 1, 150},        {7835, 132, 1},        {7838, 96, 1},
+    {7840, 1, 96},         {7944, 150, 8},        {7960, 150, 6},
+    {7976, 150, 8},        {7992, 150, 8},        {8008, 150, 6},
+    {8025, 151, 8},        {8040, 150, 8},        {8072, 150, 8},
+    {8088, 150, 8},        {8104, 150, 8},        {8120, 150, 2},
+    {8122, 126, 2},        {8124, 148, 1},        {8126, 100, 1},
+    {8136, 124, 4},        {8140, 148, 1},        {8152, 150, 2},
+    {8154, 120, 2},        {8168, 150, 2},        {8170, 118, 2},
+    {8172, 152, 1},        {8184, 112, 2},        {8186, 114, 2},
+    {8188, 148, 1},        {8486, 98, 1},         {8490, 92, 1},
+    {8491, 94, 1},         {8498, 12, 1},         {8544, 8, 16},
+    {8579, 0, 1},          {9398, 10, 26},        {11264, 22, 47},
+    {11360, 0, 1},         {11362, 88, 1},        {11363, 102, 1},
+    {11364, 90, 1},        {11367, 1, 6},         {11373, 84, 1},
+    {11374, 86, 1},        {11375, 80, 1},        {11376, 82, 1},
+    {11378, 0, 1},         {11381, 0, 1},         {11390, 78, 2},
+    {11392, 1, 100},       {11499, 1, 4},         {11506, 0, 1},
+    {42560, 1, 46},        {42624, 1, 24},        {42786, 1, 14},
+    {42802, 1, 62},        {42873, 1, 4},         {42877, 76, 1},
+    {42878, 1, 10},        {42891, 0, 1},         {42893, 74, 1},
+    {42896, 1, 4},         {42912, 1, 10},        {42922, 72, 1},
+    {65313, 14, 26},       
+  };
+  static const unsigned short aiOff[] = {
+   1,     2,     8,     15,    16,    26,    28,    32,    
+   37,    38,    40,    48,    63,    64,    69,    71,    
+   79,    80,    116,   202,   203,   205,   206,   207,   
+   209,   210,   211,   213,   214,   217,   218,   219,   
+   775,   7264,  10792, 10795, 23228, 23256, 30204, 54721, 
+   54753, 54754, 54756, 54787, 54793, 54809, 57153, 57274, 
+   57921, 58019, 58363, 61722, 65268, 65341, 65373, 65406, 
+   65408, 65410, 65415, 65424, 65436, 65439, 65450, 65462, 
+   65472, 65476, 65478, 65480, 65482, 65488, 65506, 65511, 
+   65514, 65521, 65527, 65528, 65529, 
+  };
+
+  int ret = c;
+
+  assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );
+
+  if( c<128 ){
+    if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');
+  }else if( c<65536 ){
+    const struct TableEntry *p;
+    int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
+    int iLo = 0;
+    int iRes = -1;
+
+    assert( c>aEntry[0].iCode );
+    while( iHi>=iLo ){
+      int iTest = (iHi + iLo) / 2;
+      int cmp = (c - aEntry[iTest].iCode);
+      if( cmp>=0 ){
+        iRes = iTest;
+        iLo = iTest+1;
+      }else{
+        iHi = iTest-1;
+      }
+    }
+
+    assert( iRes>=0 && c>=aEntry[iRes].iCode );
+    p = &aEntry[iRes];
+    if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){
+      ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;
+      assert( ret>0 );
+    }
+
+    if( bRemoveDiacritic ) ret = fts5_remove_diacritic(ret);
+  }
+  
+  else if( c>=66560 && c<66600 ){
+    ret = c + 40;
+  }
+
+  return ret;
+}
+
+/*
+** 2015 May 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Routines for varint serialization and deserialization.
+*/
+
+
+/* #include "fts5Int.h" */
+
+/*
+** This is a copy of the sqlite3GetVarint32() routine from the SQLite core.
+** Except, this version does handle the single byte case that the core
+** version depends on being handled before its function is called.
+*/
+static int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v){
+  u32 a,b;
+
+  /* The 1-byte case. Overwhelmingly the most common. */
+  a = *p;
+  /* a: p0 (unmasked) */
+  if (!(a&0x80))
+  {
+    /* Values between 0 and 127 */
+    *v = a;
+    return 1;
+  }
+
+  /* The 2-byte case */
+  p++;
+  b = *p;
+  /* b: p1 (unmasked) */
+  if (!(b&0x80))
+  {
+    /* Values between 128 and 16383 */
+    a &= 0x7f;
+    a = a<<7;
+    *v = a | b;
+    return 2;
+  }
+
+  /* The 3-byte case */
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<14 | p2 (unmasked) */
+  if (!(a&0x80))
+  {
+    /* Values between 16384 and 2097151 */
+    a &= (0x7f<<14)|(0x7f);
+    b &= 0x7f;
+    b = b<<7;
+    *v = a | b;
+    return 3;
+  }
+
+  /* A 32-bit varint is used to store size information in btrees.
+  ** Objects are rarely larger than 2MiB limit of a 3-byte varint.
+  ** A 3-byte varint is sufficient, for example, to record the size
+  ** of a 1048569-byte BLOB or string.
+  **
+  ** We only unroll the first 1-, 2-, and 3- byte cases.  The very
+  ** rare larger cases can be handled by the slower 64-bit varint
+  ** routine.
+  */
+  {
+    u64 v64;
+    u8 n;
+    p -= 2;
+    n = sqlite3Fts5GetVarint(p, &v64);
+    *v = (u32)v64;
+    assert( n>3 && n<=9 );
+    return n;
+  }
+}
+
+
+/*
+** Bitmasks used by sqlite3GetVarint().  These precomputed constants
+** are defined here rather than simply putting the constant expressions
+** inline in order to work around bugs in the RVT compiler.
+**
+** SLOT_2_0     A mask for  (0x7f<<14) | 0x7f
+**
+** SLOT_4_2_0   A mask for  (0x7f<<28) | SLOT_2_0
+*/
+#define SLOT_2_0     0x001fc07f
+#define SLOT_4_2_0   0xf01fc07f
+
+/*
+** Read a 64-bit variable-length integer from memory starting at p[0].
+** Return the number of bytes read.  The value is stored in *v.
+*/
+static u8 sqlite3Fts5GetVarint(const unsigned char *p, u64 *v){
+  u32 a,b,s;
+
+  a = *p;
+  /* a: p0 (unmasked) */
+  if (!(a&0x80))
+  {
+    *v = a;
+    return 1;
+  }
+
+  p++;
+  b = *p;
+  /* b: p1 (unmasked) */
+  if (!(b&0x80))
+  {
+    a &= 0x7f;
+    a = a<<7;
+    a |= b;
+    *v = a;
+    return 2;
+  }
+
+  /* Verify that constants are precomputed correctly */
+  assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );
+  assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) );
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<14 | p2 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= SLOT_2_0;
+    b &= 0x7f;
+    b = b<<7;
+    a |= b;
+    *v = a;
+    return 3;
+  }
+
+  /* CSE1 from below */
+  a &= SLOT_2_0;
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p1<<14 | p3 (unmasked) */
+  if (!(b&0x80))
+  {
+    b &= SLOT_2_0;
+    /* moved CSE1 up */
+    /* a &= (0x7f<<14)|(0x7f); */
+    a = a<<7;
+    a |= b;
+    *v = a;
+    return 4;
+  }
+
+  /* a: p0<<14 | p2 (masked) */
+  /* b: p1<<14 | p3 (unmasked) */
+  /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+  /* moved CSE1 up */
+  /* a &= (0x7f<<14)|(0x7f); */
+  b &= SLOT_2_0;
+  s = a;
+  /* s: p0<<14 | p2 (masked) */
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
+  if (!(a&0x80))
+  {
+    /* we can skip these cause they were (effectively) done above in calc'ing s */
+    /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
+    /* b &= (0x7f<<14)|(0x7f); */
+    b = b<<7;
+    a |= b;
+    s = s>>18;
+    *v = ((u64)s)<<32 | a;
+    return 5;
+  }
+
+  /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+  s = s<<7;
+  s |= b;
+  /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
+
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p1<<28 | p3<<14 | p5 (unmasked) */
+  if (!(b&0x80))
+  {
+    /* we can skip this cause it was (effectively) done above in calc'ing s */
+    /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
+    a &= SLOT_2_0;
+    a = a<<7;
+    a |= b;
+    s = s>>18;
+    *v = ((u64)s)<<32 | a;
+    return 6;
+  }
+
+  p++;
+  a = a<<14;
+  a |= *p;
+  /* a: p2<<28 | p4<<14 | p6 (unmasked) */
+  if (!(a&0x80))
+  {
+    a &= SLOT_4_2_0;
+    b &= SLOT_2_0;
+    b = b<<7;
+    a |= b;
+    s = s>>11;
+    *v = ((u64)s)<<32 | a;
+    return 7;
+  }
+
+  /* CSE2 from below */
+  a &= SLOT_2_0;
+  p++;
+  b = b<<14;
+  b |= *p;
+  /* b: p3<<28 | p5<<14 | p7 (unmasked) */
+  if (!(b&0x80))
+  {
+    b &= SLOT_4_2_0;
+    /* moved CSE2 up */
+    /* a &= (0x7f<<14)|(0x7f); */
+    a = a<<7;
+    a |= b;
+    s = s>>4;
+    *v = ((u64)s)<<32 | a;
+    return 8;
+  }
+
+  p++;
+  a = a<<15;
+  a |= *p;
+  /* a: p4<<29 | p6<<15 | p8 (unmasked) */
+
+  /* moved CSE2 up */
+  /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */
+  b &= SLOT_2_0;
+  b = b<<8;
+  a |= b;
+
+  s = s<<4;
+  b = p[-4];
+  b &= 0x7f;
+  b = b>>3;
+  s |= b;
+
+  *v = ((u64)s)<<32 | a;
+
+  return 9;
+}
+
+/*
+** The variable-length integer encoding is as follows:
+**
+** KEY:
+**         A = 0xxxxxxx    7 bits of data and one flag bit
+**         B = 1xxxxxxx    7 bits of data and one flag bit
+**         C = xxxxxxxx    8 bits of data
+**
+**  7 bits - A
+** 14 bits - BA
+** 21 bits - BBA
+** 28 bits - BBBA
+** 35 bits - BBBBA
+** 42 bits - BBBBBA
+** 49 bits - BBBBBBA
+** 56 bits - BBBBBBBA
+** 64 bits - BBBBBBBBC
+*/
+
+#ifdef SQLITE_NOINLINE
+# define FTS5_NOINLINE SQLITE_NOINLINE
+#else
+# define FTS5_NOINLINE
+#endif
+
+/*
+** Write a 64-bit variable-length integer to memory starting at p[0].
+** The length of data write will be between 1 and 9 bytes.  The number
+** of bytes written is returned.
+**
+** A variable-length integer consists of the lower 7 bits of each byte
+** for all bytes that have the 8th bit set and one byte with the 8th
+** bit clear.  Except, if we get to the 9th byte, it stores the full
+** 8 bits and is the last byte.
+*/
+static int FTS5_NOINLINE fts5PutVarint64(unsigned char *p, u64 v){
+  int i, j, n;
+  u8 buf[10];
+  if( v & (((u64)0xff000000)<<32) ){
+    p[8] = (u8)v;
+    v >>= 8;
+    for(i=7; i>=0; i--){
+      p[i] = (u8)((v & 0x7f) | 0x80);
+      v >>= 7;
+    }
+    return 9;
+  }    
+  n = 0;
+  do{
+    buf[n++] = (u8)((v & 0x7f) | 0x80);
+    v >>= 7;
+  }while( v!=0 );
+  buf[0] &= 0x7f;
+  assert( n<=9 );
+  for(i=0, j=n-1; j>=0; j--, i++){
+    p[i] = buf[j];
+  }
+  return n;
+}
+
+static int sqlite3Fts5PutVarint(unsigned char *p, u64 v){
+  if( v<=0x7f ){
+    p[0] = v&0x7f;
+    return 1;
+  }
+  if( v<=0x3fff ){
+    p[0] = ((v>>7)&0x7f)|0x80;
+    p[1] = v&0x7f;
+    return 2;
+  }
+  return fts5PutVarint64(p,v);
+}
+
+
+static int sqlite3Fts5GetVarintLen(u32 iVal){
+#if 0
+  if( iVal<(1 << 7 ) ) return 1;
+#endif
+  assert( iVal>=(1 << 7) );
+  if( iVal<(1 << 14) ) return 2;
+  if( iVal<(1 << 21) ) return 3;
+  if( iVal<(1 << 28) ) return 4;
+  return 5;
+}
+
+
+/*
+** 2015 May 08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is an SQLite virtual table module implementing direct access to an
+** existing FTS5 index. The module may create several different types of 
+** tables:
+**
+** col:
+**     CREATE TABLE vocab(term, col, doc, cnt, PRIMARY KEY(term, col));
+**
+**   One row for each term/column combination. The value of $doc is set to
+**   the number of fts5 rows that contain at least one instance of term
+**   $term within column $col. Field $cnt is set to the total number of 
+**   instances of term $term in column $col (in any row of the fts5 table). 
+**
+** row:
+**     CREATE TABLE vocab(term, doc, cnt, PRIMARY KEY(term));
+**
+**   One row for each term in the database. The value of $doc is set to
+**   the number of fts5 rows that contain at least one instance of term
+**   $term. Field $cnt is set to the total number of instances of term 
+**   $term in the database.
+*/
+
+
+/* #include "fts5Int.h" */
+
+
+typedef struct Fts5VocabTable Fts5VocabTable;
+typedef struct Fts5VocabCursor Fts5VocabCursor;
+
+struct Fts5VocabTable {
+  sqlite3_vtab base;
+  char *zFts5Tbl;                 /* Name of fts5 table */
+  char *zFts5Db;                  /* Db containing fts5 table */
+  sqlite3 *db;                    /* Database handle */
+  Fts5Global *pGlobal;            /* FTS5 global object for this database */
+  int eType;                      /* FTS5_VOCAB_COL or ROW */
+};
+
+struct Fts5VocabCursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pStmt;            /* Statement holding lock on pIndex */
+  Fts5Index *pIndex;              /* Associated FTS5 index */
+
+  int bEof;                       /* True if this cursor is at EOF */
+  Fts5IndexIter *pIter;           /* Term/rowid iterator object */
+
+  int nLeTerm;                    /* Size of zLeTerm in bytes */
+  char *zLeTerm;                  /* (term <= $zLeTerm) paramater, or NULL */
+
+  /* These are used by 'col' tables only */
+  Fts5Config *pConfig;            /* Fts5 table configuration */
+  int iCol;
+  i64 *aCnt;
+  i64 *aDoc;
+
+  /* Output values used by 'row' and 'col' tables */
+  i64 rowid;                      /* This table's current rowid value */
+  Fts5Buffer term;                /* Current value of 'term' column */
+};
+
+#define FTS5_VOCAB_COL    0
+#define FTS5_VOCAB_ROW    1
+
+#define FTS5_VOCAB_COL_SCHEMA  "term, col, doc, cnt"
+#define FTS5_VOCAB_ROW_SCHEMA  "term, doc, cnt"
+
+/*
+** Bits for the mask used as the idxNum value by xBestIndex/xFilter.
+*/
+#define FTS5_VOCAB_TERM_EQ 0x01
+#define FTS5_VOCAB_TERM_GE 0x02
+#define FTS5_VOCAB_TERM_LE 0x04
+
+
+/*
+** Translate a string containing an fts5vocab table type to an 
+** FTS5_VOCAB_XXX constant. If successful, set *peType to the output
+** value and return SQLITE_OK. Otherwise, set *pzErr to an error message
+** and return SQLITE_ERROR.
+*/
+static int fts5VocabTableType(const char *zType, char **pzErr, int *peType){
+  int rc = SQLITE_OK;
+  char *zCopy = sqlite3Fts5Strndup(&rc, zType, -1);
+  if( rc==SQLITE_OK ){
+    sqlite3Fts5Dequote(zCopy);
+    if( sqlite3_stricmp(zCopy, "col")==0 ){
+      *peType = FTS5_VOCAB_COL;
+    }else
+
+    if( sqlite3_stricmp(zCopy, "row")==0 ){
+      *peType = FTS5_VOCAB_ROW;
+    }else
+    {
+      *pzErr = sqlite3_mprintf("fts5vocab: unknown table type: %Q", zCopy);
+      rc = SQLITE_ERROR;
+    }
+    sqlite3_free(zCopy);
+  }
+
+  return rc;
+}
+
+
+/*
+** The xDisconnect() virtual table method.
+*/
+static int fts5VocabDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts5VocabTable *pTab = (Fts5VocabTable*)pVtab;
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** The xDestroy() virtual table method.
+*/
+static int fts5VocabDestroyMethod(sqlite3_vtab *pVtab){
+  Fts5VocabTable *pTab = (Fts5VocabTable*)pVtab;
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the FTS3 virtual table.
+**
+** The argv[] array contains the following:
+**
+**   argv[0]   -> module name  ("fts5vocab")
+**   argv[1]   -> database name
+**   argv[2]   -> table name
+**
+** then:
+**
+**   argv[3]   -> name of fts5 table
+**   argv[4]   -> type of fts5vocab table
+**
+** or, for tables in the TEMP schema only.
+**
+**   argv[3]   -> name of fts5 tables database
+**   argv[4]   -> name of fts5 table
+**   argv[5]   -> type of fts5vocab table
+*/
+static int fts5VocabInitVtab(
+  sqlite3 *db,                    /* The SQLite database connection */
+  void *pAux,                     /* Pointer to Fts5Global object */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
+  char **pzErr                    /* Write any error message here */
+){
+  const char *azSchema[] = { 
+    "CREATE TABlE vocab(" FTS5_VOCAB_COL_SCHEMA  ")", 
+    "CREATE TABlE vocab(" FTS5_VOCAB_ROW_SCHEMA  ")"
+  };
+
+  Fts5VocabTable *pRet = 0;
+  int rc = SQLITE_OK;             /* Return code */
+  int bDb;
+
+  bDb = (argc==6 && strlen(argv[1])==4 && memcmp("temp", argv[1], 4)==0);
+
+  if( argc!=5 && bDb==0 ){
+    *pzErr = sqlite3_mprintf("wrong number of vtable arguments");
+    rc = SQLITE_ERROR;
+  }else{
+    int nByte;                      /* Bytes of space to allocate */
+    const char *zDb = bDb ? argv[3] : argv[1];
+    const char *zTab = bDb ? argv[4] : argv[3];
+    const char *zType = bDb ? argv[5] : argv[4];
+    int nDb = (int)strlen(zDb)+1; 
+    int nTab = (int)strlen(zTab)+1;
+    int eType = 0;
+    
+    rc = fts5VocabTableType(zType, pzErr, &eType);
+    if( rc==SQLITE_OK ){
+      assert( eType>=0 && eType<ArraySize(azSchema) );
+      rc = sqlite3_declare_vtab(db, azSchema[eType]);
+    }
+
+    nByte = sizeof(Fts5VocabTable) + nDb + nTab;
+    pRet = sqlite3Fts5MallocZero(&rc, nByte);
+    if( pRet ){
+      pRet->pGlobal = (Fts5Global*)pAux;
+      pRet->eType = eType;
+      pRet->db = db;
+      pRet->zFts5Tbl = (char*)&pRet[1];
+      pRet->zFts5Db = &pRet->zFts5Tbl[nTab];
+      memcpy(pRet->zFts5Tbl, zTab, nTab);
+      memcpy(pRet->zFts5Db, zDb, nDb);
+      sqlite3Fts5Dequote(pRet->zFts5Tbl);
+      sqlite3Fts5Dequote(pRet->zFts5Db);
+    }
+  }
+
+  *ppVTab = (sqlite3_vtab*)pRet;
+  return rc;
+}
+
+
+/*
+** The xConnect() and xCreate() methods for the virtual table. All the
+** work is done in function fts5VocabInitVtab().
+*/
+static int fts5VocabConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts5VocabInitVtab(db, pAux, argc, argv, ppVtab, pzErr);
+}
+static int fts5VocabCreateMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pAux,                     /* Pointer to tokenizer hash table */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  return fts5VocabInitVtab(db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/* 
+** Implementation of the xBestIndex method.
+*/
+static int fts5VocabBestIndexMethod(
+  sqlite3_vtab *pUnused,
+  sqlite3_index_info *pInfo
+){
+  int i;
+  int iTermEq = -1;
+  int iTermGe = -1;
+  int iTermLe = -1;
+  int idxNum = 0;
+  int nArg = 0;
+
+  UNUSED_PARAM(pUnused);
+
+  for(i=0; i<pInfo->nConstraint; i++){
+    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
+    if( p->usable==0 ) continue;
+    if( p->iColumn==0 ){          /* term column */
+      if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ) iTermEq = i;
+      if( p->op==SQLITE_INDEX_CONSTRAINT_LE ) iTermLe = i;
+      if( p->op==SQLITE_INDEX_CONSTRAINT_LT ) iTermLe = i;
+      if( p->op==SQLITE_INDEX_CONSTRAINT_GE ) iTermGe = i;
+      if( p->op==SQLITE_INDEX_CONSTRAINT_GT ) iTermGe = i;
+    }
+  }
+
+  if( iTermEq>=0 ){
+    idxNum |= FTS5_VOCAB_TERM_EQ;
+    pInfo->aConstraintUsage[iTermEq].argvIndex = ++nArg;
+    pInfo->estimatedCost = 100;
+  }else{
+    pInfo->estimatedCost = 1000000;
+    if( iTermGe>=0 ){
+      idxNum |= FTS5_VOCAB_TERM_GE;
+      pInfo->aConstraintUsage[iTermGe].argvIndex = ++nArg;
+      pInfo->estimatedCost = pInfo->estimatedCost / 2;
+    }
+    if( iTermLe>=0 ){
+      idxNum |= FTS5_VOCAB_TERM_LE;
+      pInfo->aConstraintUsage[iTermLe].argvIndex = ++nArg;
+      pInfo->estimatedCost = pInfo->estimatedCost / 2;
+    }
+  }
+
+  pInfo->idxNum = idxNum;
+
+  return SQLITE_OK;
+}
+
+/*
+** Implementation of xOpen method.
+*/
+static int fts5VocabOpenMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_vtab_cursor **ppCsr
+){
+  Fts5VocabTable *pTab = (Fts5VocabTable*)pVTab;
+  Fts5Index *pIndex = 0;
+  Fts5Config *pConfig = 0;
+  Fts5VocabCursor *pCsr = 0;
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pStmt = 0;
+  char *zSql = 0;
+
+  zSql = sqlite3Fts5Mprintf(&rc,
+      "SELECT t.%Q FROM %Q.%Q AS t WHERE t.%Q MATCH '*id'",
+      pTab->zFts5Tbl, pTab->zFts5Db, pTab->zFts5Tbl, pTab->zFts5Tbl
+  );
+  if( zSql ){
+    rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
+  }
+  sqlite3_free(zSql);
+  assert( rc==SQLITE_OK || pStmt==0 );
+  if( rc==SQLITE_ERROR ) rc = SQLITE_OK;
+
+  if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
+    i64 iId = sqlite3_column_int64(pStmt, 0);
+    pIndex = sqlite3Fts5IndexFromCsrid(pTab->pGlobal, iId, &pConfig);
+  }
+
+  if( rc==SQLITE_OK && pIndex==0 ){
+    rc = sqlite3_finalize(pStmt);
+    pStmt = 0;
+    if( rc==SQLITE_OK ){
+      pVTab->zErrMsg = sqlite3_mprintf(
+          "no such fts5 table: %s.%s", pTab->zFts5Db, pTab->zFts5Tbl
+      );
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    int nByte = pConfig->nCol * sizeof(i64) * 2 + sizeof(Fts5VocabCursor);
+    pCsr = (Fts5VocabCursor*)sqlite3Fts5MallocZero(&rc, nByte);
+  }
+
+  if( pCsr ){
+    pCsr->pIndex = pIndex;
+    pCsr->pStmt = pStmt;
+    pCsr->pConfig = pConfig;
+    pCsr->aCnt = (i64*)&pCsr[1];
+    pCsr->aDoc = &pCsr->aCnt[pConfig->nCol];
+  }else{
+    sqlite3_finalize(pStmt);
+  }
+
+  *ppCsr = (sqlite3_vtab_cursor*)pCsr;
+  return rc;
+}
+
+static void fts5VocabResetCursor(Fts5VocabCursor *pCsr){
+  pCsr->rowid = 0;
+  sqlite3Fts5IterClose(pCsr->pIter);
+  pCsr->pIter = 0;
+  sqlite3_free(pCsr->zLeTerm);
+  pCsr->nLeTerm = -1;
+  pCsr->zLeTerm = 0;
+}
+
+/*
+** Close the cursor.  For additional information see the documentation
+** on the xClose method of the virtual table interface.
+*/
+static int fts5VocabCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  fts5VocabResetCursor(pCsr);
+  sqlite3Fts5BufferFree(&pCsr->term);
+  sqlite3_finalize(pCsr->pStmt);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+
+/*
+** Advance the cursor to the next row in the table.
+*/
+static int fts5VocabNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  Fts5VocabTable *pTab = (Fts5VocabTable*)pCursor->pVtab;
+  int rc = SQLITE_OK;
+  int nCol = pCsr->pConfig->nCol;
+
+  pCsr->rowid++;
+
+  if( pTab->eType==FTS5_VOCAB_COL ){
+    for(pCsr->iCol++; pCsr->iCol<nCol; pCsr->iCol++){
+      if( pCsr->aDoc[pCsr->iCol] ) break;
+    }
+  }
+
+  if( pTab->eType==FTS5_VOCAB_ROW || pCsr->iCol>=nCol ){
+    if( sqlite3Fts5IterEof(pCsr->pIter) ){
+      pCsr->bEof = 1;
+    }else{
+      const char *zTerm;
+      int nTerm;
+
+      zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);
+      if( pCsr->nLeTerm>=0 ){
+        int nCmp = MIN(nTerm, pCsr->nLeTerm);
+        int bCmp = memcmp(pCsr->zLeTerm, zTerm, nCmp);
+        if( bCmp<0 || (bCmp==0 && pCsr->nLeTerm<nTerm) ){
+          pCsr->bEof = 1;
+          return SQLITE_OK;
+        }
+      }
+
+      sqlite3Fts5BufferSet(&rc, &pCsr->term, nTerm, (const u8*)zTerm);
+      memset(pCsr->aCnt, 0, nCol * sizeof(i64));
+      memset(pCsr->aDoc, 0, nCol * sizeof(i64));
+      pCsr->iCol = 0;
+
+      assert( pTab->eType==FTS5_VOCAB_COL || pTab->eType==FTS5_VOCAB_ROW );
+      while( rc==SQLITE_OK ){
+        const u8 *pPos; int nPos;   /* Position list */
+        i64 iPos = 0;               /* 64-bit position read from poslist */
+        int iOff = 0;               /* Current offset within position list */
+
+        pPos = pCsr->pIter->pData;
+        nPos = pCsr->pIter->nData;
+        switch( pCsr->pConfig->eDetail ){
+          case FTS5_DETAIL_FULL:
+            pPos = pCsr->pIter->pData;
+            nPos = pCsr->pIter->nData;
+            if( pTab->eType==FTS5_VOCAB_ROW ){
+              while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){
+                pCsr->aCnt[0]++;
+              }
+              pCsr->aDoc[0]++;
+            }else{
+              int iCol = -1;
+              while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){
+                int ii = FTS5_POS2COLUMN(iPos);
+                pCsr->aCnt[ii]++;
+                if( iCol!=ii ){
+                  if( ii>=nCol ){
+                    rc = FTS5_CORRUPT;
+                    break;
+                  }
+                  pCsr->aDoc[ii]++;
+                  iCol = ii;
+                }
+              }
+            }
+            break;
+
+          case FTS5_DETAIL_COLUMNS:
+            if( pTab->eType==FTS5_VOCAB_ROW ){
+              pCsr->aDoc[0]++;
+            }else{
+              while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff,&iPos) ){
+                assert_nc( iPos>=0 && iPos<nCol );
+                if( iPos>=nCol ){
+                  rc = FTS5_CORRUPT;
+                  break;
+                }
+                pCsr->aDoc[iPos]++;
+              }
+            }
+            break;
+
+          default: 
+            assert( pCsr->pConfig->eDetail==FTS5_DETAIL_NONE );
+            pCsr->aDoc[0]++;
+            break;
+        }
+
+        if( rc==SQLITE_OK ){
+          rc = sqlite3Fts5IterNextScan(pCsr->pIter);
+        }
+
+        if( rc==SQLITE_OK ){
+          zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);
+          if( nTerm!=pCsr->term.n || memcmp(zTerm, pCsr->term.p, nTerm) ){
+            break;
+          }
+          if( sqlite3Fts5IterEof(pCsr->pIter) ) break;
+        }
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK && pCsr->bEof==0 && pTab->eType==FTS5_VOCAB_COL ){
+    while( pCsr->aDoc[pCsr->iCol]==0 ) pCsr->iCol++;
+    assert( pCsr->iCol<pCsr->pConfig->nCol );
+  }
+  return rc;
+}
+
+/*
+** This is the xFilter implementation for the virtual table.
+*/
+static int fts5VocabFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *zUnused,            /* Unused */
+  int nUnused,                    /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  int rc = SQLITE_OK;
+
+  int iVal = 0;
+  int f = FTS5INDEX_QUERY_SCAN;
+  const char *zTerm = 0;
+  int nTerm = 0;
+
+  sqlite3_value *pEq = 0;
+  sqlite3_value *pGe = 0;
+  sqlite3_value *pLe = 0;
+
+  UNUSED_PARAM2(zUnused, nUnused);
+
+  fts5VocabResetCursor(pCsr);
+  if( idxNum & FTS5_VOCAB_TERM_EQ ) pEq = apVal[iVal++];
+  if( idxNum & FTS5_VOCAB_TERM_GE ) pGe = apVal[iVal++];
+  if( idxNum & FTS5_VOCAB_TERM_LE ) pLe = apVal[iVal++];
+
+  if( pEq ){
+    zTerm = (const char *)sqlite3_value_text(pEq);
+    nTerm = sqlite3_value_bytes(pEq);
+    f = 0;
+  }else{
+    if( pGe ){
+      zTerm = (const char *)sqlite3_value_text(pGe);
+      nTerm = sqlite3_value_bytes(pGe);
+    }
+    if( pLe ){
+      const char *zCopy = (const char *)sqlite3_value_text(pLe);
+      pCsr->nLeTerm = sqlite3_value_bytes(pLe);
+      pCsr->zLeTerm = sqlite3_malloc(pCsr->nLeTerm+1);
+      if( pCsr->zLeTerm==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        memcpy(pCsr->zLeTerm, zCopy, pCsr->nLeTerm+1);
+      }
+    }
+  }
+
+
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts5IndexQuery(pCsr->pIndex, zTerm, nTerm, f, 0, &pCsr->pIter);
+  }
+  if( rc==SQLITE_OK ){
+    rc = fts5VocabNextMethod(pCursor);
+  }
+
+  return rc;
+}
+
+/* 
+** This is the xEof method of the virtual table. SQLite calls this 
+** routine to find out if it has reached the end of a result set.
+*/
+static int fts5VocabEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  return pCsr->bEof;
+}
+
+static int fts5VocabColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  int eDetail = pCsr->pConfig->eDetail;
+  int eType = ((Fts5VocabTable*)(pCursor->pVtab))->eType;
+  i64 iVal = 0;
+
+  if( iCol==0 ){
+    sqlite3_result_text(
+        pCtx, (const char*)pCsr->term.p, pCsr->term.n, SQLITE_TRANSIENT
+    );
+  }else if( eType==FTS5_VOCAB_COL ){
+    assert( iCol==1 || iCol==2 || iCol==3 );
+    if( iCol==1 ){
+      if( eDetail!=FTS5_DETAIL_NONE ){
+        const char *z = pCsr->pConfig->azCol[pCsr->iCol];
+        sqlite3_result_text(pCtx, z, -1, SQLITE_STATIC);
+      }
+    }else if( iCol==2 ){
+      iVal = pCsr->aDoc[pCsr->iCol];
+    }else{
+      iVal = pCsr->aCnt[pCsr->iCol];
+    }
+  }else{
+    assert( iCol==1 || iCol==2 );
+    if( iCol==1 ){
+      iVal = pCsr->aDoc[0];
+    }else{
+      iVal = pCsr->aCnt[0];
+    }
+  }
+
+  if( iVal>0 ) sqlite3_result_int64(pCtx, iVal);
+  return SQLITE_OK;
+}
+
+/* 
+** This is the xRowid method. The SQLite core calls this routine to
+** retrieve the rowid for the current row of the result set. The
+** rowid should be written to *pRowid.
+*/
+static int fts5VocabRowidMethod(
+  sqlite3_vtab_cursor *pCursor, 
+  sqlite_int64 *pRowid
+){
+  Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;
+  *pRowid = pCsr->rowid;
+  return SQLITE_OK;
+}
+
+static int sqlite3Fts5VocabInit(Fts5Global *pGlobal, sqlite3 *db){
+  static const sqlite3_module fts5Vocab = {
+    /* iVersion      */ 2,
+    /* xCreate       */ fts5VocabCreateMethod,
+    /* xConnect      */ fts5VocabConnectMethod,
+    /* xBestIndex    */ fts5VocabBestIndexMethod,
+    /* xDisconnect   */ fts5VocabDisconnectMethod,
+    /* xDestroy      */ fts5VocabDestroyMethod,
+    /* xOpen         */ fts5VocabOpenMethod,
+    /* xClose        */ fts5VocabCloseMethod,
+    /* xFilter       */ fts5VocabFilterMethod,
+    /* xNext         */ fts5VocabNextMethod,
+    /* xEof          */ fts5VocabEofMethod,
+    /* xColumn       */ fts5VocabColumnMethod,
+    /* xRowid        */ fts5VocabRowidMethod,
+    /* xUpdate       */ 0,
+    /* xBegin        */ 0,
+    /* xSync         */ 0,
+    /* xCommit       */ 0,
+    /* xRollback     */ 0,
+    /* xFindFunction */ 0,
+    /* xRename       */ 0,
+    /* xSavepoint    */ 0,
+    /* xRelease      */ 0,
+    /* xRollbackTo   */ 0,
+  };
+  void *p = (void*)pGlobal;
+
+  return sqlite3_create_module_v2(db, "fts5vocab", &fts5Vocab, p, 0);
+}
+
+
+
+
+    
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS5) */
+
+/************** End of fts5.c ************************************************/