Fossil

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.7.8"
#define SQLITE_VERSION_NUMBER 3007008
#define SQLITE_SOURCE_ID      "2011-09-04 01:27:00 6b657ae75035eb10b0ad640998d3c9eadfdffa6e"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
** on the command-line
*/
#ifndef SQLITE_TEMP_STORE
# define SQLITE_TEMP_STORE 1
#endif









/*
** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
#endif

** 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 */


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 sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*);

#define OP_AutoCommit                          33
#define OP_Transaction                         34
#define OP_ReadCookie                          35
#define OP_SetCookie                           36
#define OP_VerifyCookie                        37
#define OP_OpenRead                            38
#define OP_OpenWrite                           39

#define OP_OpenAutoindex                       40
#define OP_OpenEphemeral                       41
#define OP_SorterOpen                          42
#define OP_OpenPseudo                          43
#define OP_Close                               44
#define OP_SeekLt                              45
#define OP_SeekLe                              46
#define OP_SeekGe                              47
#define OP_SeekGt                              48
#define OP_Seek                                49
#define OP_NotFound                            50
#define OP_Found                               51
#define OP_IsUnique                            52
#define OP_NotExists                           53
#define OP_Sequence                            54
#define OP_NewRowid                            55
#define OP_Insert                              56
#define OP_InsertInt                           57
#define OP_Delete                              58
#define OP_ResetCount                          59
#define OP_SorterCompare                       60
#define OP_SorterData                          61
#define OP_RowKey                              62
#define OP_RowData                             63
#define OP_Rowid                               64
#define OP_NullRow                             65
#define OP_Last                                66
#define OP_SorterSort                          67
#define OP_Sort                                70
#define OP_Rewind                              71
#define OP_SorterNext                          72
#define OP_Prev                                81
#define OP_Next                                92
#define OP_SorterInsert                        95
#define OP_IdxInsert                           96
#define OP_IdxDelete                           97
#define OP_IdxRowid                            98
#define OP_IdxLT                               99
#define OP_IdxGE                              100
#define OP_Destroy                            101
#define OP_Clear                              102
#define OP_CreateIndex                        103
#define OP_CreateTable                        104
#define OP_ParseSchema                        105
#define OP_LoadAnalysis                       106
#define OP_DropTable                          107
#define OP_DropIndex                          108
#define OP_DropTrigger                        109
#define OP_IntegrityCk                        110
#define OP_RowSetAdd                          111
#define OP_RowSetRead                         112
#define OP_RowSetTest                         113
#define OP_Program                            114
#define OP_Param                              115
#define OP_FkCounter                          116
#define OP_FkIfZero                           117
#define OP_MemMax                             118
#define OP_IfPos                              119
#define OP_IfNeg                              120
#define OP_IfZero                             121
#define OP_AggStep                            122
#define OP_AggFinal                           123
#define OP_Checkpoint                         124
#define OP_JournalMode                        125
#define OP_Vacuum                             126
#define OP_IncrVacuum                         127
#define OP_Expire                             128
#define OP_TableLock                          129
#define OP_VBegin                             131
#define OP_VCreate                            132
#define OP_VDestroy                           133
#define OP_VOpen                              134
#define OP_VFilter                            135
#define OP_VColumn                            136
#define OP_VNext                              137
#define OP_VRename                            138
#define OP_VUpdate                            139
#define OP_Pagecount                          140
#define OP_MaxPgcnt                           146
#define OP_Trace                              147
#define OP_Noop                               148
#define OP_Explain                            149





/* 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 */

/*   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, 0x00, 0x00, 0x00, 0x02,\
/*  32 */ 0x00, 0x00, 0x00, 0x02, 0x10, 0x00, 0x00, 0x00,\
/*  40 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x11, 0x11, 0x11,\
/*  48 */ 0x11, 0x08, 0x11, 0x11, 0x11, 0x11, 0x02, 0x02,\
/*  56 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/*  64 */ 0x02, 0x00, 0x01, 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, 0x08,\
/*  96 */ 0x08, 0x00, 0x02, 0x01, 0x01, 0x02, 0x00, 0x02,\
/* 104 */ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0c,\
/* 112 */ 0x45, 0x15, 0x01, 0x02, 0x00, 0x01, 0x08, 0x05,\
/* 120 */ 0x05, 0x05, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01,\
/* 128 */ 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x01,\
/* 136 */ 0x00, 0x01, 0x00, 0x00, 0x02, 0x04, 0x04, 0x04,\

/* 144 */ 0x04, 0x04, 0x02, 0x00, 0x00, 0x00,}

/************** End of opcodes.h *********************************************/
/************** Continuing where we left off in vdbe.h ***********************/

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.

SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*);
SQLITE_PRIVATE const sqlite3_vfs *sqlite3PagerVfs(Pager*);
SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*);
SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*);
SQLITE_PRIVATE int sqlite3PagerNosync(Pager*);
SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*);
SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager*);




/* Functions used to truncate the database file. */
SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager*,Pgno);

#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL)
SQLITE_PRIVATE void *sqlite3PagerCodec(DbPage *);
#endif

*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** 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 */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */

*/
#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".
*/
#define SRT_Union        1  /* Store result as keys in an index */

#endif
#ifdef SQLITE_INT64_TYPE
  "INT64_TYPE",
#endif
#ifdef SQLITE_LOCK_TRACE
  "LOCK_TRACE",
#endif
#ifdef SQLITE_MAX_SCHEMA_RETRY
  "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),
#endif
#ifdef SQLITE_MEMDEBUG
  "MEMDEBUG",
#endif
#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
  "MIXED_ENDIAN_64BIT_FLOAT",
#endif
#ifdef SQLITE_NO_SYNC

  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 */
  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;

  /* Cached information about the header for the data record that the
  ** cursor is currently pointing to.  Only valid if cacheStatus matches

#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 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 *);
#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);
SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)

     /*  33 */ "AutoCommit",
     /*  34 */ "Transaction",
     /*  35 */ "ReadCookie",
     /*  36 */ "SetCookie",
     /*  37 */ "VerifyCookie",
     /*  38 */ "OpenRead",
     /*  39 */ "OpenWrite",
     /*  40 */ "OpenAutoindex",
     /*  41 */ "OpenEphemeral",
     /*  42 */ "SorterOpen",
     /*  43 */ "OpenPseudo",
     /*  44 */ "Close",
     /*  45 */ "SeekLt",
     /*  46 */ "SeekLe",
     /*  47 */ "SeekGe",
     /*  48 */ "SeekGt",
     /*  49 */ "Seek",
     /*  50 */ "NotFound",
     /*  51 */ "Found",
     /*  52 */ "IsUnique",
     /*  53 */ "NotExists",
     /*  54 */ "Sequence",
     /*  55 */ "NewRowid",
     /*  56 */ "Insert",
     /*  57 */ "InsertInt",
     /*  58 */ "Delete",
     /*  59 */ "ResetCount",
     /*  60 */ "SorterCompare",
     /*  61 */ "SorterData",
     /*  62 */ "RowKey",
     /*  63 */ "RowData",
     /*  64 */ "Rowid",
     /*  65 */ "NullRow",
     /*  66 */ "Last",
     /*  67 */ "SorterSort",
     /*  68 */ "Or",
     /*  69 */ "And",
     /*  70 */ "Sort",
     /*  71 */ "Rewind",
     /*  72 */ "SorterNext",
     /*  73 */ "IsNull",
     /*  74 */ "NotNull",
     /*  75 */ "Ne",
     /*  76 */ "Eq",
     /*  77 */ "Gt",
     /*  78 */ "Le",
     /*  79 */ "Lt",
     /*  80 */ "Ge",
     /*  81 */ "Prev",
     /*  82 */ "BitAnd",
     /*  83 */ "BitOr",
     /*  84 */ "ShiftLeft",
     /*  85 */ "ShiftRight",
     /*  86 */ "Add",
     /*  87 */ "Subtract",
     /*  88 */ "Multiply",
     /*  89 */ "Divide",
     /*  90 */ "Remainder",
     /*  91 */ "Concat",
     /*  92 */ "Next",
     /*  93 */ "BitNot",
     /*  94 */ "String8",
     /*  95 */ "SorterInsert",
     /*  96 */ "IdxInsert",
     /*  97 */ "IdxDelete",
     /*  98 */ "IdxRowid",
     /*  99 */ "IdxLT",
     /* 100 */ "IdxGE",
     /* 101 */ "Destroy",
     /* 102 */ "Clear",
     /* 103 */ "CreateIndex",
     /* 104 */ "CreateTable",
     /* 105 */ "ParseSchema",
     /* 106 */ "LoadAnalysis",
     /* 107 */ "DropTable",
     /* 108 */ "DropIndex",
     /* 109 */ "DropTrigger",
     /* 110 */ "IntegrityCk",
     /* 111 */ "RowSetAdd",
     /* 112 */ "RowSetRead",
     /* 113 */ "RowSetTest",
     /* 114 */ "Program",
     /* 115 */ "Param",
     /* 116 */ "FkCounter",
     /* 117 */ "FkIfZero",
     /* 118 */ "MemMax",
     /* 119 */ "IfPos",
     /* 120 */ "IfNeg",
     /* 121 */ "IfZero",
     /* 122 */ "AggStep",
     /* 123 */ "AggFinal",
     /* 124 */ "Checkpoint",
     /* 125 */ "JournalMode",
     /* 126 */ "Vacuum",
     /* 127 */ "IncrVacuum",
     /* 128 */ "Expire",
     /* 129 */ "TableLock",
     /* 130 */ "Real",
     /* 131 */ "VBegin",
     /* 132 */ "VCreate",
     /* 133 */ "VDestroy",
     /* 134 */ "VOpen",
     /* 135 */ "VFilter",
     /* 136 */ "VColumn",
     /* 137 */ "VNext",
     /* 138 */ "VRename",
     /* 139 */ "VUpdate",
     /* 140 */ "Pagecount",
     /* 141 */ "ToText",
     /* 142 */ "ToBlob",
     /* 143 */ "ToNumeric",
     /* 144 */ "ToInt",
     /* 145 */ "ToReal",
     /* 146 */ "MaxPgcnt",
     /* 147 */ "Trace",
     /* 148 */ "Noop",
     /* 149 */ "Explain",
  };
  return azName[i];
}
#endif

/************** End of opcodes.c *********************************************/
/************** Begin file os_os2.c ******************************************/

** 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)

** 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)

*/
SQLITE_API int sqlite3_sync_count = 0;
SQLITE_API int sqlite3_fullsync_count = 0;
#endif

/*
** 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
*/
#if !defined(fdatasync)
# define fdatasync fsync
#endif

/*
** Define HAVE_FULLFSYNC to 0 or 1 depending on whether or not
** the F_FULLFSYNC macro is defined.  F_FULLFSYNC is currently
** only available on Mac OS X.  But that could change.

/* 
** This function is called to handle the SQLITE_FCNTL_SIZE_HINT 
** file-control operation.  Enlarge the database to nBytes in size
** (rounded up to the next chunk-size).  If the database is already
** nBytes or larger, this routine is a no-op.
*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){
  if( pFile->szChunk>0 ){
    i64 nSize;                    /* Required file size */
    struct stat buf;              /* Used to hold return values of 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 ){

** All other fields are read/write.  The unixShm.pFile->mutex must be held
** while accessing any read/write fields.
*/
struct unixShm {
  unixShmNode *pShmNode;     /* The underlying unixShmNode object */
  unixShm *pNext;            /* Next unixShm with the same unixShmNode */
  u8 hasMutex;               /* True if holding the unixShmNode mutex */
  u8 id;                     /* Id of this connection within its unixShmNode */
  u16 sharedMask;            /* Mask of shared locks held */
  u16 exclMask;              /* Mask of exclusive locks held */



};

/*
** Constants used for locking
*/
#define UNIX_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)         /* first lock byte */
#define UNIX_SHM_DMS    (UNIX_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */

** 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)

  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>0 ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  /* 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) ){

      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      if( pFile->szChunk>0 ){
        sqlite3_int64 oldSz;
        int rc = winFileSize(id, &oldSz);
        if( rc==SQLITE_OK ){
          sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
          if( newSz>oldSz ){
            SimulateIOErrorBenign(1);
            rc = winTruncate(id, newSz);
            SimulateIOErrorBenign(0);
          }
        }
        return rc;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = pFile->bPersistWal;
      }else{
        pFile->bPersistWal = bPersist!=0;

  u8 fullSync;                /* Do extra syncs of the journal for robustness */
  u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
  u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
  u8 tempFile;                /* zFilename is a temporary file */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */
  u8 hasSeenStress;           /* pagerStress() called one or more times */


  /**************************************************************************
  ** The following block contains those class members that change during
  ** routine opertion.  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

    assert( p->journalMode==PAGER_JOURNALMODE_OFF 
         || p->journalMode==PAGER_JOURNALMODE_MEMORY 
    );
    assert( p->eState!=PAGER_ERROR && p->eState!=PAGER_OPEN );
    assert( pagerUseWal(p)==0 );
  }










  /* If changeCountDone is set, a RESERVED lock or greater must be held
  ** on the file.
  */
  assert( pPager->changeCountDone==0 || pPager->eLock>=RESERVED_LOCK );
  assert( p->eLock!=PENDING_LOCK );

  switch( p->eState ){

  }else if( memDb ){
    pPager->journalMode = PAGER_JOURNALMODE_MEMORY;
  }
  /* pPager->xBusyHandler = 0; */
  /* pPager->pBusyHandlerArg = 0; */
  pPager->xReiniter = xReinit;
  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */







  *ppPager = pPager;
  return SQLITE_OK;
}

/*
** Return true if this is an in-memory pager.
*/
SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){
  return MEMDB;
}












/*
** Check that there are at least nSavepoint savepoints open. If there are
** currently less than nSavepoints open, then open one or more savepoints
** to make up the difference. If the number of savepoints is already
** equal to nSavepoint, then this function is a no-op.
**
** If a memory allocation fails, SQLITE_NOMEM is returned. If an error 

  /* Only a BTREE_SINGLE database can be BTREE_UNORDERED */
  assert( (flags & BTREE_UNORDERED)==0 || (flags & BTREE_SINGLE)!=0 );

  /* 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;

  }
  if( (vfsFlags & SQLITE_OPEN_MAIN_DB)!=0 && (isMemdb || isTempDb) ){
    vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;
  }
  p = sqlite3MallocZero(sizeof(Btree));
  if( !p ){
    return SQLITE_NOMEM;

    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])
        ){
          put4byte(&pCell[info.iOverflow], iTo);
          break;

        }
      }else{
        if( get4byte(pCell)==iFrom ){
          put4byte(pCell, iTo);
          break;
        }
      }

  u32 ovflPageSize;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  btreeParseCellPtr(pPage, pCell, &info);
  if( info.iOverflow==0 ){
    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 */
  }
  ovflPgno = get4byte(&pCell[info.iOverflow]);
  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( ovflPgno==0 || nOvfl>0 );
  while( nOvfl-- ){
    Pgno iNext = 0;

    */
    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
    releasePage(pPage);
  }
  return rc;  
}
SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){

  int rc;
  sqlite3BtreeEnter(p);





  rc = btreeDropTable(p, iTable, piMoved);

  sqlite3BtreeLeave(p);
  return rc;
}


/*
** This function may only be called if the b-tree connection already

    }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;
#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;
    }

      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;
      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
  ********************************************************************/

  assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
  sqlite3VdbeEnter(p);
  if( p->rc==SQLITE_NOMEM ){

/* Opcode: OpenAutoindex P1 P2 * P4 *
**
** This opcode works the same as OP_OpenEphemeral.  It has a
** different name to distinguish its use.  Tables created using
** by this opcode will be used for automatically created transient
** indices in joins.
*/







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 =
      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,
                        BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(u.ax.pCx->pBt, 1);

    }else{
      rc = sqlite3BtreeCursor(u.ax.pCx->pBt, MASTER_ROOT, 1, 0, u.ax.pCx->pCursor);
      u.ax.pCx->isTable = 1;
    }
  }
  u.ax.pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  u.ax.pCx->isIndex = !u.ax.pCx->isTable;
  break;
}

/* Opcode: OpenSorter P1 P2 * 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.
*/
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
  break;
}

/* Opcode: OpenPseudo P1 P2 P3 * *
**
** 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
** register P2.  In other words, cursor P1 becomes an alias for the 
** MEM_Blob content contained in register P2.
**
** A pseudo-table created by this opcode is used to hold a single
** row output from the sorter so that the row can be decomposed into
** individual columns using the OP_Column opcode.  The OP_Column opcode
** is the only cursor opcode that works with a pseudo-table.
**
** P3 is the number of fields in the records that will be stored by
** 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;
  break;
}

/* Opcode: Close P1 * * * *
**
** Close a cursor previously opened as P1.  If P1 is not
** currently open, this instruction is a no-op.

**
** 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 */

  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--;
        }
      }
      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( u.ba.res==0 ){
        u.ba.pC->rowidIsValid = 1;
        u.ba.pC->lastRowid = u.ba.iKey;
      }
    }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;

      /* 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 );

      u.ba.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]) ); }
#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;
    }
    u.ba.pC->deferredMoveto = 0;
    u.ba.pC->cacheStatus = CACHE_STALE;
#ifdef SQLITE_TEST
    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;
      }
    }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;
    }
  }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).
    */

** 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;
  }
  break;
}
  

/* Opcode: Found P1 P2 P3 P4 *
**

** falls through to the next instruction and P1 is left pointing at the
** matching entry.
**
** See also: Found, NotExists, IsUnique
*/
case OP_NotFound:       /* jump, in3 */
case OP_Found: {        /* jump, in3 */
#if 0  /* local variables moved into u.bc */
  int alreadyExists;
  VdbeCursor *pC;
  int res;
  UnpackedRecord *pIdxKey;
  UnpackedRecord r;
  char aTempRec[ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*3 + 7];
#endif /* local variables moved into u.bc */

#ifdef SQLITE_TEST
  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 );
  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;
#ifdef SQLITE_DEBUG
      { int i; for(i=0; i<u.bc.r.nField; i++) assert( memIsValid(&u.bc.r.aMem[i]) ); }
#endif
      u.bc.r.flags = UNPACKED_PREFIX_MATCH;
      u.bc.pIdxKey = &u.bc.r;
    }else{
      assert( pIn3->flags & MEM_Blob );
      assert( (pIn3->flags & MEM_Zero)==0 );  /* zeroblobs already expanded */
      u.bc.pIdxKey = sqlite3VdbeRecordUnpack(u.bc.pC->pKeyInfo, pIn3->n, pIn3->z,
                                        u.bc.aTempRec, sizeof(u.bc.aTempRec));
      if( u.bc.pIdxKey==0 ){
        goto no_mem;
      }
      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 ){
      sqlite3VdbeDeleteUnpackedRecord(u.bc.pIdxKey);
    }
    if( rc!=SQLITE_OK ){
      break;
    }
    u.bc.alreadyExists = (u.bc.res==0);
    u.bc.pC->deferredMoveto = 0;
    u.bc.pC->cacheStatus = CACHE_STALE;
  }
  if( pOp->opcode==OP_Found ){
    if( u.bc.alreadyExists ) pc = pOp->p2 - 1;
  }else{
    if( !u.bc.alreadyExists ) pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IsUnique P1 P2 P3 P4 *
**
** Cursor P1 is open on an index b-tree - that is to say, a btree which

** to instruction P2. Otherwise, the rowid of the conflicting index
** entry is copied to register P3 and control falls through to the next
** instruction.
**
** See also: NotFound, NotExists, Found
*/
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 * *
**
** 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.
**
** 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.
**
** See also: Found, NotFound, IsUnique
*/
case OP_NotExists: {        /* jump, in3 */
#if 0  /* local variables moved into u.be */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  u64 iKey;
#endif /* local variables moved into u.be */

  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;
  }
  break;
}

/* Opcode: Sequence P1 P2 * * *
**
** Find the next available sequence number for cursor P1.

** the largest previously generated record number. No new record numbers are
** allowed to be less than this value. When this value reaches its maximum, 
** an SQLITE_FULL error is generated. The P3 register is updated with the '
** 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 */
  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;
  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{
    /* The next rowid or record number (different terms for the same
    ** thing) is obtained in a two-step algorithm.
    **
    ** First we attempt to find the largest existing rowid and add one
    ** to that.  But if the largest existing rowid is already the maximum
    ** positive integer, we have to fall through to the second
    ** probabilistic algorithm
    **
    ** The second algorithm is to select a rowid at random and see if
    ** it already exists in the table.  If it does not exist, we have
    ** succeeded.  If the random rowid does exist, we select a new one
    ** and try again, up to 100 times.
    */
    assert( u.bf.pC->isTable );

#ifdef SQLITE_32BIT_ROWID
#   define MAX_ROWID 0x7fffffff
#else
    /* Some compilers complain about constants of the form 0x7fffffffffffffff.
    ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
    ** to provide the constant while making all compilers happy.
    */
#   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 */
        }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 */
          }
        }
      }

#ifndef SQLITE_OMIT_AUTOINCREMENT
      if( pOp->p3 ){
        /* 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;
      }
#endif

      sqlite3BtreeSetCachedRowid(u.bf.pC->pCursor, u.bf.v<MAX_ROWID ? u.bf.v+1 : 0);
    }
    if( u.bf.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 ){
        rc = SQLITE_FULL;   /* IMP: R-38219-53002 */
        goto abort_due_to_error;
      }
      assert( u.bf.v>0 );  /* EV: R-40812-03570 */
    }
    u.bf.pC->rowidIsValid = 0;
    u.bf.pC->deferredMoveto = 0;
    u.bf.pC->cacheStatus = CACHE_STALE;
  }
  pOut->u.i = u.bf.v;
  break;
}

/* Opcode: Insert P1 P2 P3 P4 P5
**
** 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

/* Opcode: InsertInt P1 P2 P3 P4 P5
**
** 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 */
  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
#endif /* local variables moved into u.bg */

  u.bg.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);

  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;
  }else{
    assert( pOp->opcode==OP_InsertInt );
    u.bg.iKey = pOp->p3;
  }

  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;
  }else{
    assert( u.bg.pData->flags & (MEM_Blob|MEM_Str) );
  }
  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;
  }else{
    u.bg.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
  );
  u.bg.pC->rowidIsValid = 0;
  u.bg.pC->deferredMoveto = 0;
  u.bg.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 );
  }
  break;
}

/* Opcode: Delete P1 P2 * P4 *
**
** Delete the record at which the P1 cursor is currently pointing.

**
** 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.
*/
case OP_Delete: {
#if 0  /* local variables moved into u.bh */
  i64 iKey;
  VdbeCursor *pC;
#endif /* local variables moved into u.bh */

  u.bh.iKey = 0;
  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 */

  /* 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;
  }

  /* 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;

  sqlite3BtreeSetCachedRowid(u.bh.pC->pCursor, 0);
  rc = sqlite3BtreeDelete(u.bh.pC->pCursor);
  u.bh.pC->cacheStatus = CACHE_STALE;

  /* 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( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
/* Opcode: ResetCount * * * * *
**
** The value of the change counter is copied to the database handle
** change counter (returned by subsequent calls to sqlite3_changes()).
** Then the VMs internal change counter resets to 0.
** This is used by trigger programs.
*/
case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}

/* Opcode: SorterCompare P1 P2 P3
**
** 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.
*/
case OP_SorterCompare: {
#if 0  /* local variables moved into u.bi */
  VdbeCursor *pC;
  int res;
#endif /* local variables moved into u.bi */

  u.bi.pC = p->apCsr[pOp->p1];
  assert( isSorter(u.bi.pC) );
  pIn3 = &aMem[pOp->p3];
  rc = sqlite3VdbeSorterCompare(u.bi.pC, pIn3, &u.bi.res);
  if( u.bi.res ){
    pc = pOp->p2-1;
  }
  break;
};

/* Opcode: SorterData P1 P2 * * *
**
** Write into register P2 the current sorter data for sorter cursor P1.
*/
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
  break;
}

/* Opcode: RowData P1 P2 * * *
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.  
** It is just copied onto the P2 register exactly as 
** it is found in the database file.

** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
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) );

  /* 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 );
    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{
    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;
    }
  }
  if( sqlite3VdbeMemGrow(pOut, u.bk.n, 0) ){
    goto no_mem;
  }
  pOut->n = u.bk.n;
  MemSetTypeFlag(pOut, MEM_Blob);
  if( u.bk.pC->isIndex ){
    rc = sqlite3BtreeKey(u.bk.pCrsr, 0, u.bk.n, pOut->z);
  }else{
    rc = sqlite3BtreeData(u.bk.pCrsr, 0, u.bk.n, pOut->z);
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Rowid P1 P2 * * *
**
** Store in register P2 an integer which is the key of the table entry that
** P1 is currently point to.
**
** P1 can be either an ordinary table or a virtual table.  There used to
** 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 */
  VdbeCursor *pC;
  i64 v;
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
#endif /* local variables moved into u.bl */

  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 ){
    pOut->flags = MEM_Null;
    break;
  }else if( u.bl.pC->deferredMoveto ){
    u.bl.v = u.bl.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);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  }else{
    assert( u.bl.pC->pCursor!=0 );
    rc = sqlite3VdbeCursorMoveto(u.bl.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 */
    }
  }
  pOut->u.i = u.bl.v;
  break;
}

/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always
** 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);
  }
  break;
}

/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Next 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.
*/
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;
  if( NEVER(u.bn.pCrsr==0) ){
    u.bn.res = 1;
  }else{
    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;
  }
  break;
}


/* Opcode: Sort P1 P2 * * *
**
** This opcode does exactly the same thing as OP_Rewind except that
** it increments an undocumented global variable used for testing.
**
** Sorting is accomplished by writing records into a sorting index,
** then rewinding that index and playing it back from beginning to
** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
** rewinding so that the global variable will be incremented and
** regression tests can determine whether or not the optimizer is
** 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]++;
  /* 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.
*/
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;
  assert( pOp->p2>0 && pOp->p2<p->nOp );
  if( u.bo.res ){
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: Next P1 P2 * P4 P5
**

**
** P4 is always of type P4_ADVANCE. The function pointer points to
** sqlite3BtreePrevious().
**
** 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 */
  VdbeCursor *pC;
  int res;
#endif /* local variables moved into u.bp */

  CHECK_FOR_INTERRUPT;
  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]++;
#ifdef SQLITE_TEST
    sqlite3_search_count++;
#endif
  }
  u.bp.pC->rowidIsValid = 0;
  break;
}

/* Opcode: IdxInsert P1 P2 P3 * P5
**
** Register P2 holds an SQL index key made using the
** MakeRecord instructions.  This opcode writes that key
** into the index P1.  Data for the entry is nil.
**
** P3 is a flag that provides a hint to the b-tree layer that this
** insert is likely to be an append.
**
** 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 */

  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) );
  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;
      }

    }
  }
  break;
}

/* Opcode: IdxDelete P1 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->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;
  }
  break;
}

/* Opcode: IdxRowid P1 P2 * * *
**
** 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
** the rowid of the table entry to which this index entry points.
**
** 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 */

  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;
      pOut->flags = MEM_Int;
    }
  }
  break;
}

/* Opcode: IdxGE P1 P2 P3 P4 P5

** Otherwise fall through to the next instruction.
**
** 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.
*/
case OP_IdxLT:          /* jump */
case OP_IdxGE: {        /* jump */
#if 0  /* local variables moved into u.bt */
  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];
#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 ;
    }
  }
  break;
}

/* Opcode: Destroy P1 P2 P3 * *

** movement was required (because the table being dropped was already 
** the last one in the database) then a zero is stored in register P2.
** If AUTOVACUUM is disabled then a zero is stored in register P2.
**
** See also: Clear
*/
case OP_Destroy: {     /* out2-prerelease */
#if 0  /* local variables moved into u.bu */
  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
  pOut->flags = MEM_Null;
  if( u.bu.iCnt>1 ){
    rc = SQLITE_LOCKED;
    p->errorAction = OE_Abort;
  }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);
    pOut->flags = MEM_Int;
    pOut->u.i = u.bu.iMoved;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( rc==SQLITE_OK && u.bu.iMoved!=0 ){
      sqlite3RootPageMoved(db, u.bu.iDb, u.bu.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;
    }
#endif
  }
  break;
}

/* Opcode: Clear P1 P2 P3

** count is incremented by the number of rows in the table being cleared. 
** If P3 is greater than zero, then the value stored in register P3 is
** also incremented by the number of rows in the table being cleared.
**
** 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 );
  rc = sqlite3BtreeClearTable(
      db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &u.bv.nChange : 0)
  );
  if( pOp->p3 ){
    p->nChange += u.bv.nChange;
    if( pOp->p3>0 ){
      assert( memIsValid(&aMem[pOp->p3]) );
      memAboutToChange(p, &aMem[pOp->p3]);
      aMem[pOp->p3].u.i += u.bv.nChange;
    }
  }
  break;
}

/* Opcode: CreateTable P1 P2 * * *
**

** P1>1.  Write the root page number of the new table into
** register P2.
**
** 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 */
  int pgno;
  int flags;
  Db *pDb;
#endif /* local variables moved into u.bw */

  u.bw.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 );
  if( pOp->opcode==OP_CreateTable ){
    /* u.bw.flags = BTREE_INTKEY; */
    u.bw.flags = BTREE_INTKEY;
  }else{
    u.bw.flags = BTREE_BLOBKEY;
  }
  rc = sqlite3BtreeCreateTable(u.bw.pDb->pBt, &u.bw.pgno, u.bw.flags);
  pOut->u.i = u.bw.pgno;
  break;
}

/* Opcode: ParseSchema P1 * * P4 *
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P4. 
**
** This opcode invokes the parser to create a new virtual machine,
** 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
  ** 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) );
  }
#endif

  u.bx.iDb = pOp->p1;
  assert( u.bx.iDb>=0 && u.bx.iDb<db->nDb );
  assert( DbHasProperty(db, u.bx.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,
       "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;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      u.bx.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);
      db->init.busy = 0;
    }
  }
  if( rc==SQLITE_NOMEM ){
    goto no_mem;
  }
  break;

**
** If P5 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** 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 );
  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;
  sqlite3VdbeMemSetNull(pIn1);
  if( u.by.nErr==0 ){
    assert( u.by.z==0 );
  }else if( u.by.z==0 ){
    goto no_mem;
  }else{
    sqlite3VdbeMemSetStr(pIn1, u.by.z, -1, SQLITE_UTF8, sqlite3_free);
  }
  UPDATE_MAX_BLOBSIZE(pIn1);
  sqlite3VdbeChangeEncoding(pIn1, encoding);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/* Opcode: RowSetRead P1 P2 P3 * *
**
** 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
  ){
    /* The boolean index is empty */
    sqlite3VdbeMemSetNull(pIn1);
    pc = pOp->p2 - 1;
  }else{
    /* A value was pulled from the index */
    sqlite3VdbeMemSetInt64(&aMem[pOp->p3], u.bz.val);
  }
  break;
}

/* Opcode: RowSetTest P1 P2 P3 P4
**
** Register P3 is assumed to hold a 64-bit integer value. If register P1

** (b) when P4==-1 there is no need to insert the value, as it will
** never be tested for, and (c) when a value that is part of set X is
** inserted, there is no need to search to see if the same value was
** previously inserted as part of set X (only if it was previously
** 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;
  assert( pIn3->flags&MEM_Int );

  /* If there is anything other than a rowset object in memory cell P1,
  ** delete it now and initialize P1 with an empty rowset
  */
  if( (pIn1->flags & MEM_RowSet)==0 ){
    sqlite3VdbeMemSetRowSet(pIn1);
    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
  }

  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;
    }
  }
  if( u.ca.iSet>=0 ){
    sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
  }
  break;
}


#ifndef SQLITE_OMIT_TRIGGER

** exception using the RAISE() function. Register P3 contains the address 
** of a memory cell in this (the parent) VM that is used to allocate the 
** memory required by the sub-vdbe at runtime.
**
** P4 is a pointer to the VM containing the trigger program.
*/
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 */
  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 */
#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
  ** 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
  ** ON CONFLICT algorithm). SubProgram structures associated with a
  ** 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;
  }

  if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
    break;
  }

  /* Register u.cb.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
  ** 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
    ** 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.
    */
    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 ){
      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;
    }
  }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 );
  }

  p->nFrame++;
  u.cb.pFrame->pParent = p->pFrame;
  u.cb.pFrame->lastRowid = lastRowid;
  u.cb.pFrame->nChange = p->nChange;
  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;

  break;
}

/* Opcode: Param P1 P2 * * *
**
** This opcode is only ever present in sub-programs called via the 
** OP_Program instruction. Copy a value currently stored in a memory 
** cell of the calling (parent) frame to cell P2 in the current frames 
** address space. This is used by trigger programs to access the new.* 
** and old.* values.
**
** The address of the cell in the parent frame is determined by adding
** 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 */
  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);
  break;
}

#endif /* #ifndef SQLITE_OMIT_TRIGGER */

#ifndef SQLITE_OMIT_FOREIGN_KEY
/* Opcode: FkCounter P1 P2 * * *

** within a sub-program). Set the value of register P1 to the maximum of 
** its current value and the value in register P2.
**
** This instruction throws an error if the memory cell is not initially
** 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];
  }else{
    u.cd.pIn1 = &aMem[pOp->p1];
  }
  assert( memIsValid(u.cd.pIn1) );
  sqlite3VdbeMemIntegerify(u.cd.pIn1);
  pIn2 = &aMem[pOp->p2];
  sqlite3VdbeMemIntegerify(pIn2);
  if( u.cd.pIn1->u.i<pIn2->u.i){
    u.cd.pIn1->u.i = pIn2->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfPos P1 P2 * * *
**

** structure that specifies the function.  Use register
** P3 as the accumulator.
**
** The P5 arguments are taken from register P2 and its
** successors.
*/
case OP_AggStep: {
#if 0  /* local variables moved into u.ce */
  int n;
  int i;
  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;
  }

  sqlite3VdbeMemRelease(&u.ce.ctx.s);

  break;
}

/* Opcode: AggFinal P1 P2 * P4 *
**
** Execute the finalizer function for an aggregate.  P1 is
** the memory location that is the accumulator for the aggregate.
**
** P2 is the number of arguments that the step function takes and
** P4 is a pointer to the FuncDef for this function.  The P2
** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** 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);
  if( rc ){
    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(u.cf.pMem));
  }
  sqlite3VdbeChangeEncoding(u.cf.pMem, encoding);
  UPDATE_MAX_BLOBSIZE(u.cf.pMem);
  if( sqlite3VdbeMemTooBig(u.cf.pMem) ){
    goto too_big;
  }
  break;
}

#ifndef SQLITE_OMIT_WAL
/* 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
** 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
** completes into mem[P3+2].  However on an error, mem[P3+1] and
** 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( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
       || pOp->p2==SQLITE_CHECKPOINT_FULL
       || pOp->p2==SQLITE_CHECKPOINT_RESTART
  );
  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &u.cg.aRes[1], &u.cg.aRes[2]);
  if( rc==SQLITE_BUSY ){
    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]);
  }
  break;
};  
#endif

#ifndef SQLITE_OMIT_PRAGMA
/* Opcode: JournalMode P1 P2 P3 * P5
**
** 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
** modes (delete, truncate, persist, off and memory), this is a simple
** operation. No IO is required.
**
** If changing into or out of WAL mode the procedure is more complicated.
**
** Write a string containing the final journal-mode to register P2.
*/
case OP_JournalMode: {    /* out2-prerelease */
#if 0  /* local variables moved into u.ch */
  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 */
#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
  );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );

  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;

#ifndef SQLITE_OMIT_WAL
  u.ch.zFilename = sqlite3PagerFilename(u.ch.pPager);

  /* Do not allow a transition to journal_mode=WAL for a database
  ** in temporary storage or if the VFS does not support shared memory
  */
  if( u.ch.eNew==PAGER_JOURNALMODE_WAL
   && (u.ch.zFilename[0]==0                         /* Temp file */
       || !sqlite3PagerWalSupported(u.ch.pPager))   /* No shared-memory support */
  ){
    u.ch.eNew = u.ch.eOld;
  }

  if( (u.ch.eNew!=u.ch.eOld)
   && (u.ch.eOld==PAGER_JOURNALMODE_WAL || u.ch.eNew==PAGER_JOURNALMODE_WAL)
  ){
    if( !db->autoCommit || db->activeVdbeCnt>1 ){
      rc = SQLITE_ERROR;
      sqlite3SetString(&p->zErrMsg, db,
          "cannot change %s wal mode from within a transaction",
          (u.ch.eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")
      );
      break;
    }else{

      if( u.ch.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.
        */
        rc = sqlite3PagerCloseWal(u.ch.pPager);
        if( rc==SQLITE_OK ){
          sqlite3PagerSetJournalMode(u.ch.pPager, u.ch.eNew);
        }
      }else if( u.ch.eOld==PAGER_JOURNALMODE_MEMORY ){
        /* Cannot transition directly from MEMORY to WAL.  Use mode OFF
        ** as an intermediate */
        sqlite3PagerSetJournalMode(u.ch.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 );
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeSetVersion(u.ch.pBt, (u.ch.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);

  pOut = &aMem[pOp->p2];
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = (char *)sqlite3JournalModename(u.ch.eNew);
  pOut->n = sqlite3Strlen30(pOut->z);
  pOut->enc = SQLITE_UTF8;
  sqlite3VdbeChangeEncoding(pOut, encoding);
  break;
};
#endif /* SQLITE_OMIT_PRAGMA */

/* Opcode: IncrVacuum P1 P2 * * *
**
** Perform a single step of the incremental vacuum procedure on
** the P1 database. If the vacuum has finished, jump to instruction
** 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;
    rc = SQLITE_OK;
  }
  break;
}
#endif

** xBegin method for that table.
**
** Also, whether or not P4 is set, check that this is not being called from
** within a callback to a virtual table xSync() method. If it is, the error
** 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);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VCreate P1 * * P4 *
**

/* Opcode: VOpen P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** 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 *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;

    /* 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);
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE

** xFilter method. Registers P3+2..P3+1+argc are the argc
** additional parameters which are passed to
** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
**
** 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 *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;

  /* 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;

  /* 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;

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VColumn P1 P2 P3 * *
**
** 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);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(u.cm.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) ){
    goto too_big;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VNext P1 P2 * * *
**
** Advance virtual table P1 to the next row in its result set and
** jump to instruction P2.  Or, if the virtual table has reached
** 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 ){
    break;
  }
  u.cn.pVtab = u.cn.pCur->pVtabCursor->pVtab;
  u.cn.pModule = u.cn.pVtab->pModule;
  assert( u.cn.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
  ** 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 ){
    /* If there is data, jump to P2 */
    pc = pOp->p2 - 1;
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VRename P1 * * P4 *
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xRename method. The value
** 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 );
  rc = u.co.pVtab->pModule->xRename(u.co.pVtab, u.co.pName->z);
  importVtabErrMsg(p, u.co.pVtab);
  p->expired = 0;

  break;
}
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE

** a row to delete.
**
** 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.
*/
case OP_VUpdate: {
#if 0  /* local variables moved into u.cp */
  sqlite3_vtab *pVtab;
  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
       || 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( pOp->p4type==P4_VTAB );
  if( ALWAYS(u.cp.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++;
    }
    db->vtabOnConflict = pOp->p5;
    rc = u.cp.pModule->xUpdate(u.cp.pVtab, u.cp.nArg, u.cp.apArg, &u.cp.rowid);
    db->vtabOnConflict = vtabOnConflict;
    importVtabErrMsg(p, u.cp.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;
    }
    if( rc==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){
      if( pOp->p5==OE_Ignore ){
        rc = SQLITE_OK;
      }else{
        p->errorAction = ((pOp->p5==OE_Replace) ? OE_Abort : pOp->p5);
      }

#ifndef SQLITE_OMIT_TRACE
/* Opcode: Trace * * * P4 *
**
** If tracing is enabled (by the sqlite3_trace()) interface, then
** the UTF-8 string contained in P4 is emitted on the trace callback.
*/
case OP_Trace: {
#if 0  /* local variables moved into u.cq */
  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);
  }
#ifdef SQLITE_DEBUG
  if( (db->flags & SQLITE_SqlTrace)!=0
   && (u.cq.zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    sqlite3DebugPrintf("SQL-trace: %s\n", u.cq.zTrace);
  }
#endif /* SQLITE_DEBUG */
  break;
}
#endif

** memory).
*/


#ifndef SQLITE_OMIT_MERGE_SORT

typedef struct VdbeSorterIter VdbeSorterIter;
typedef struct SorterRecord SorterRecord;

/*
** NOTES ON DATA STRUCTURE USED FOR N-WAY MERGES:
**
** 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

**     aTree[] = { X, 0   0, 6    0, 3, 5, 6 }
**
** In other words, each time we advance to the next sorter element, log2(N)
** key comparison operations are required, where N is the number of segments
** being merged (rounded up to the next power of 2).
*/
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 */
  char *aSpace;                   /* Space for UnpackRecord() */
  int nSpace;                     /* Size of aSpace in bytes */
};

/*
** 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.
*/
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 */
};

/*
** 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.
*/
struct SorterRecord {
  void *pVal;
  int nVal;
  SorterRecord *pNext;
};

/* Minimum allowable value for the VdbeSorter.nWorking variable */
#define SORTER_MIN_WORKING 10

/* Maximum number of segments to merge in a single pass. */
#define SORTER_MAX_MERGE_COUNT 16

*/
static int vdbeSorterIterNext(
  sqlite3 *db,                    /* Database handle (for sqlite3DbMalloc() ) */
  VdbeSorterIter *pIter           /* Iterator to advance */
){
  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 */

  nRead = pIter->iEof - pIter->iReadOff;
  if( nRead>5 ) nRead = 5;
  if( nRead<=0 ){
    /* This is an EOF condition */
    vdbeSorterIterZero(db, pIter);
    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( rc!=SQLITE_OK || nRec>0 );
  pIter->iReadOff += iOff+nRec;
  pIter->nKey = nRec;
  pIter->aKey = &pIter->aAlloc[iOff];
  return rc;
}

/*

** (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.
*/
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 */






  rc = sqlite3OsRead(pFile, aVarint, 9, iOff);
  if( rc==SQLITE_OK ){
    *piOffset += getVarint(aVarint, (u64 *)piVal);
  }

  return rc;
}

  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);
    *pnByte += nByte;
    pIter->iEof = pIter->iReadOff + nByte;
  }
  if( rc==SQLITE_OK ){
    rc = vdbeSorterIterNext(db, pIter);
  }
  return rc;
}


/*
** 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 int 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 */
){
  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
  VdbeSorter *pSorter = pCsr->pSorter;
  char *aSpace = pSorter->aSpace;
  int nSpace = pSorter->nSpace;
  UnpackedRecord *r2;
  int i;

  if( aSpace==0 ){
    nSpace = ROUND8(sizeof(UnpackedRecord))+(pKeyInfo->nField+1)*sizeof(Mem);
    aSpace = (char *)sqlite3Malloc(nSpace);
    if( aSpace==0 ) return SQLITE_NOMEM;
    pSorter->aSpace = aSpace;
    pSorter->nSpace = nSpace;
  }

  if( pKey2 ){
    /* This call cannot fail. As the memory is already allocated. */
    r2 = sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, aSpace, nSpace);
    assert( r2 && (r2->flags & UNPACKED_NEED_FREE)==0 );
    assert( r2==(UnpackedRecord*)aSpace );
  }else{
    r2 = (UnpackedRecord *)aSpace;
    assert( !bOmitRowid );
  }

  if( bOmitRowid ){
    for(i=0; i<r2->nField-1; i++){
      if( r2->aMem[i].flags & MEM_Null ){
        *pRes = -1;
        return SQLITE_OK;
      }
    }
    r2->flags |= UNPACKED_PREFIX_MATCH;
    r2->nField--;
    assert( r2->nField>0 );
  }

  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
  return SQLITE_OK;
}

/*
** 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.
*/
static int vdbeSorterDoCompare(VdbeCursor *pCsr, int iOut){
  VdbeSorter *pSorter = pCsr->pSorter;

  p2 = &pSorter->aIter[i2];

  if( p1->pFile==0 ){
    iRes = i2;
  }else if( p2->pFile==0 ){
    iRes = i1;
  }else{
    int res;
    int rc;
    assert( pCsr->pSorter->aSpace!=0 );  /* allocated in vdbeSorterMerge() */
    rc = vdbeSorterCompare(
        pCsr, 0, p1->aKey, p1->nKey, p2->aKey, p2->nKey, &res
    );
    /* The vdbeSorterCompare() call cannot fail since pCsr->pSorter->aSpace
    ** has already been allocated. */
    assert( rc==SQLITE_OK );

    if( res<=0 ){
      iRes = i1;
    }else{
      iRes = i2;
    }

  }

  pSorter->aTree[iOut] = iRes;
  return SQLITE_OK;
}

/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
  int pgsz;                       /* Page size of main database */
  int mxCache;                    /* Cache size */
  VdbeSorter *pSorter;            /* The new sorter */

  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  pCsr->pSorter = pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
  if( pSorter==0 ){
    return SQLITE_NOMEM;
  }

  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;
  }

  return SQLITE_OK;
}

/*
** Free the list of sorted records starting at pRecord.
*/
static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
  SorterRecord *p;
  SorterRecord *pNext;
  for(p=pRecord; p; p=pNext){
    pNext = p->pNext;
    sqlite3DbFree(db, p);
  }
}

/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
  VdbeSorter *pSorter = pCsr->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);
    sqlite3_free(pSorter->aSpace);
    sqlite3DbFree(db, pSorter);
    pCsr->pSorter = 0;
  }
}

/*
** 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.
*/
static int vdbeSorterOpenTempFile(sqlite3 *db, sqlite3_file **ppFile){
  int dummy;
  return sqlite3OsOpenMalloc(db->pVfs, 0, ppFile,
      SQLITE_OPEN_TEMP_JOURNAL |
      SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &dummy
  );
}

/*
** Attemp to merge the two sorted lists p1 and p2 into a single list. If no
** error occurs set *ppOut to the head of the new list and return SQLITE_OK.
*/
static int vdbeSorterMerge(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* For pKeyInfo */
  SorterRecord *p1,               /* First list to merge */
  SorterRecord *p2,               /* Second list to merge */
  SorterRecord **ppOut            /* OUT: Head of merged list */
){
  int rc = SQLITE_OK;
  SorterRecord *pFinal = 0;
  SorterRecord **pp = &pFinal;
  void *pVal2 = p2 ? p2->pVal : 0;

  while( p1 && p2 ){
    int res;
    rc = vdbeSorterCompare(pCsr, 0, p1->pVal, p1->nVal, pVal2, p2->nVal, &res);
    if( rc!=SQLITE_OK ){
      *pp = 0;
      vdbeSorterRecordFree(db, p1);
      vdbeSorterRecordFree(db, p2);
      vdbeSorterRecordFree(db, pFinal);
      *ppOut = 0;
      return rc;
    }
    if( res<=0 ){
      *pp = p1;
      pp = &p1->pNext;
      p1 = p1->pNext;
      pVal2 = 0;
    }else{
      *pp = p2;
       pp = &p2->pNext;
      p2 = p2->pNext;
      if( p2==0 ) break;
      pVal2 = p2->pVal;
    }
  }
  *pp = p1 ? p1 : p2;

  *ppOut = pFinal;
  return SQLITE_OK;
}

/*
** 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.
*/
static int vdbeSorterSort(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;
  int i;
  SorterRecord **aSlot;
  SorterRecord *p;
  VdbeSorter *pSorter = pCsr->pSorter;

  aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));
  if( !aSlot ){
    return SQLITE_NOMEM;
  }

  p = pSorter->pRecord;
  while( p ){
    SorterRecord *pNext = p->pNext;
    p->pNext = 0;
    for(i=0; rc==SQLITE_OK && aSlot[i]; i++){
      rc = vdbeSorterMerge(db, pCsr, p, aSlot[i], &p);
      aSlot[i] = 0;
    }
    if( rc!=SQLITE_OK ){
      vdbeSorterRecordFree(db, pNext);
      break;
    }
    aSlot[i] = p;
    p = pNext;
  }

  p = 0;
  for(i=0; i<64; i++){
    if( rc==SQLITE_OK ){
      rc = vdbeSorterMerge(db, pCsr, p, aSlot[i], &p);
    }else{
      vdbeSorterRecordFree(db, aSlot[i]);
    }
  }
  pSorter->pRecord = p;

  sqlite3_free(aSlot);
  return rc;
}


/*
** Write the current contents of the in-memory linked-list to a PMA. Return
** SQLITE_OK if successful, or an SQLite error code otherwise.
**
** The format of a PMA is:
**
**     * A varint. This varint contains the total number of bytes of content
**       in the PMA (not including the varint itself).
**
**     * One or more records packed end-to-end in order of ascending keys. 
**       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){
  int rc = SQLITE_OK;             /* Return code */
  VdbeSorter *pSorter = pCsr->pSorter;



  if( pSorter->nInMemory==0 ){


    assert( pSorter->pRecord==0 );
    return rc;
  }

  rc = vdbeSorterSort(db, pCsr);

  /* 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( 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);












      if( rc==SQLITE_OK ){



        rc = sqlite3OsWrite(pSorter->pTemp1, p->pVal, p->nVal, iOff);
        iOff += p->nVal;
      }

      sqlite3DbFree(db, p);

    }

    /* 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)
    ));

    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);
    }
    pSorter->pRecord = p;
  }

  return rc;
}

/*
** Add a record to the sorter.










*/
SQLITE_PRIVATE int sqlite3VdbeSorterWrite(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal                       /* Memory cell containing record */
){
  VdbeSorter *pSorter = pCsr->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;
  }else{
    pNew->pVal = (void *)&pNew[1];
    memcpy(pNew->pVal, pVal->z, pVal->n);



    pNew->nVal = pVal->n;

    pNew->pNext = pSorter->pRecord;

    pSorter->pRecord = pNew;
  }









  /* See if the contents of the sorter should now be written out. They
  ** are written out when either of the following are true:
  **
  **   * The total memory allocated for the in-memory list is greater 
  **     than (page-size * cache-size), or

  **
  **   * 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;

  }




  return rc;
}

/*
** 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 */

  /* 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;
  }

  /* Initialize the aTree[] array. */
  for(i=pSorter->nTree-1; rc==SQLITE_OK && i>0; i--){
    rc = vdbeSorterDoCompare(pCsr, i);
  }

  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 */

  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->nPMA==0 ){
    *pbEof = !pSorter->pRecord;
    assert( pSorter->aTree==0 );
    return vdbeSorterSort(db, pCsr);
  }

  /* Write the current b-tree to a PMA. Close the b-tree cursor. */
  rc = vdbeSorterListToPMA(db, pCsr);
  if( rc!=SQLITE_OK ) return rc;

  /* 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));

}

/*
** Advance to the next element in the sorter.
*/
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);
  }else{
    SorterRecord *pFree = pSorter->pRecord;
    pSorter->pRecord = pFree->pNext;
    pFree->pNext = 0;
    vdbeSorterRecordFree(db, pFree);
    *pbEof = !pSorter->pRecord;
    rc = SQLITE_OK;
  }
  return rc;
}

/*
** Return a pointer to a buffer owned by the sorter that contains the 
** current key.
*/
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;
}

/*
** Copy the current sorter key into the memory cell pOut.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
  VdbeSorter *pSorter = pCsr->pSorter;
  void *pKey; int nKey;           /* Sorter key to copy into pOut */


  pKey = vdbeSorterRowkey(pSorter, &nKey);





  if( sqlite3VdbeMemGrow(pOut, nKey, 0) ){

    return SQLITE_NOMEM;
  }
  pOut->n = nKey;
  MemSetTypeFlag(pOut, MEM_Blob);
  memcpy(pOut->z, pKey, nKey);

  return SQLITE_OK;
}

/*
** 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 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.
*/
SQLITE_PRIVATE int sqlite3VdbeSorterCompare(
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal,                      /* Value to compare to current sorter key */
  int *pRes                       /* OUT: Result of comparison */
){
  int rc;
  VdbeSorter *pSorter = pCsr->pSorter;
  void *pKey; int nKey;           /* Sorter key to compare pVal with */

  pKey = vdbeSorterRowkey(pSorter, &nKey);
  rc = vdbeSorterCompare(pCsr, 1, pVal->z, pVal->n, pKey, nKey, pRes);
  assert( rc!=SQLITE_OK || pVal->db->mallocFailed || (*pRes)<=0 );
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */

/************** End of vdbesort.c ********************************************/
/************** Begin file journal.c *****************************************/
/*
** 2007 August 22

      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        inReg = pCol->iMem;
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                              pCol->iSorterColumn, target);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){

*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
  int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */
  int iSorter = iTab;            /* Cursor opened by OpenSorter (if in use) */
  int addr1;                     /* Address of top of loop */
  int addr2;                     /* Address to jump to for next iteration */
  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */
  int regIdxKey;                 /* Registers containing the index key */
  int regRecord;                 /* Register holding assemblied index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);










#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
      db->aDb[iDb].zName ) ){
    return;
  }
#endif

  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
  if( memRootPage>=0 ){
    sqlite3VdbeChangeP5(v, 1);
  }

#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);
#endif


  /* 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);
  addr2 = addr1 + 1;
  regRecord = sqlite3GetTempReg(pParse);
  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);


#ifndef SQLITE_OMIT_MERGE_SORT
  sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);
  addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0);
  if( pIndex->onError!=OE_None ){
    int j2 = sqlite3VdbeCurrentAddr(v) + 3;
    sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
    addr2 = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp3(v, OP_SorterCompare, iSorter, j2, regRecord);
    sqlite3HaltConstraint(
        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC
    );
  }else{
    addr2 = sqlite3VdbeCurrentAddr(v);
  }
  sqlite3VdbeAddOp2(v, OP_SorterData, iSorter, regRecord);
  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 1);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
#else
  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_IdxInsert, iIdx, regRecord, 0);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
#endif
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2);
  sqlite3VdbeJumpHere(v, addr1);

  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
  sqlite3VdbeAddOp1(v, OP_Close, iSorter);
}

  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 ){
    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;

  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, pseudoTab, regRow, nColumn);
    regRowid = 0;
  }else{
    regRowid = sqlite3GetTempReg(pParse);
  }
  if( p->selFlags & SF_UseSorter ){
    int regSortOut = ++pParse->nMem;
    int ptab2 = pParse->nTab++;
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, ptab2, regSortOut, pOrderBy->nExpr+2);
    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);
  }else{
    addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak);
    codeOffset(v, p, addrContinue);
    sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr+1, regRow);
  }
  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);

  }
  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);
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr);
  }
  sqlite3VdbeResolveLabel(v, addrBreak);
  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
  }
}

/*

  }

  /* Set the limiter.
  */
  iEnd = sqlite3VdbeMakeLabel(v);
  p->nSelectRow = (double)LARGEST_INT64;
  computeLimitRegisters(pParse, p, iEnd);
  if( p->iLimit==0 && addrSortIndex>=0 ){
    sqlite3VdbeGetOp(v, addrSortIndex)->opcode = OP_SorterOpen;
    p->selFlags |= SF_UseSorter;
  }

  /* Open a virtual index to use for the distinct set.
  */
  if( p->selFlags & SF_Distinct ){
    KeyInfo *pKeyInfo;
    distinct = pParse->nTab++;
    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);

      sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
      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;

    int iBMem;          /* First Mem address for previous GROUP BY */
    int iUseFlag;       /* Mem address holding flag indicating that at least
                        ** one row of the input to the aggregator has been
                        ** processed */
    int iAbortFlag;     /* Mem address which causes query abort if positive */
    int groupBySort;    /* Rows come from source in GROUP BY order */
    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 */

    /* Remove any and all aliases between the result set and the
    ** GROUP BY clause.
    */
    if( pGroupBy ){
      int k;                        /* Loop counter */
      struct ExprList_item *pItem;  /* For looping over expression in a list */

      int addrTopOfLoop;  /* Top of the input loop */
      int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
      int addrReset;      /* Subroutine for resetting the accumulator */
      int regReset;       /* Return address register for reset subroutine */

      /* If there is a GROUP BY clause we might need a sorting index to
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OP_SorterOpen instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
      addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, 
          sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
          0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = ++pParse->nMem;
      iAbortFlag = ++pParse->nMem;

              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
            }
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sAggInfo.sortingIdxPTab = sortPTab = pParse->nTab++;
        sortOut = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
        sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
        sqlite3ExprCacheClear(pParse);
      }

      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
      ** Then compare the current GROUP BY terms against the GROUP BY terms
      ** from the previous row currently stored in a0, a1, a2...
      */
      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
      sqlite3ExprCacheClear(pParse);
      if( groupBySort ){
        sqlite3VdbeAddOp2(v, OP_SorterData, sAggInfo.sortingIdx, sortOut);
      }
      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);

      updateAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
      VdbeComment((v, "indicate data in accumulator"));

      /* End of the loop
      */
      if( groupBySort ){
        sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);
      }else{
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
      }

      /* Output the final row of result
      */

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.7.8"
#define SQLITE_VERSION_NUMBER 3007008
#define SQLITE_SOURCE_ID      "2011-09-04 01:27:00 6b657ae75035eb10b0ad640998d3c9eadfdffa6e"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros