Fossil

** the text of this file.  Search for "Begin file sqlite3.h" to find the start
** of the embedded sqlite3.h header file.) Additional code files may be needed
** if you want a wrapper to interface SQLite with your choice of programming
** language. The code for the "sqlite3" command-line shell is also in a
** separate file. This file contains only code for the core SQLite library.
**
** The content in this amalgamation comes from Fossil check-in
** 720387f8604f7cd997f1850ed62ce6ab3260 with changes in files:
**
**    
*/
#ifndef SQLITE_AMALGAMATION
#define SQLITE_CORE 1
#define SQLITE_AMALGAMATION 1
#ifndef SQLITE_PRIVATE

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.51.0"
#define SQLITE_VERSION_NUMBER 3051000
#define SQLITE_SOURCE_ID      "2025-07-08 20:28:35 720387f8604f7cd997f1850ed62ce6ab32608155d7f02a89c695041caafc4067"

/*
** 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

**   0x00004000     Push-down optimization
**   0x00008000     After all FROM-clause analysis
**   0x00010000     Beginning of DELETE/INSERT/UPDATE processing
**   0x00020000     Transform DISTINCT into GROUP BY
**   0x00040000     SELECT tree dump after all code has been generated
**   0x00080000     NOT NULL strength reduction
**   0x00100000     Pointers are all shown as zero
**   0x00200000     EXISTS-to-JOIN optimization
*/

/*
** Macros for "wheretrace"
*/
SQLITE_PRIVATE u32 sqlite3WhereTrace;
#if defined(SQLITE_DEBUG) \

  int nData;              /* Size of pData.  0 if none. */
  int nZero;              /* Extra zero data appended after pData,nData */
};

SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,
                       int flags, int seekResult);
SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeIsEmpty(BtCursor *pCur, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int flags);
SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);
SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int flags);
SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor*);
SQLITE_PRIVATE void sqlite3BtreeCursorPin(BtCursor*);
SQLITE_PRIVATE void sqlite3BtreeCursorUnpin(BtCursor*);

#define OP_SeekRowid      30 /* jump0, synopsis: intkey=r[P3]              */
#define OP_NotExists      31 /* jump, synopsis: intkey=r[P3]               */
#define OP_Last           32 /* jump0                                      */
#define OP_IfSizeBetween  33 /* jump                                       */
#define OP_SorterSort     34 /* jump                                       */
#define OP_Sort           35 /* jump                                       */
#define OP_Rewind         36 /* jump0                                      */
#define OP_IfEmpty        37 /* jump, synopsis: if( empty(P1) ) goto P2    */
#define OP_SorterNext     38 /* jump                                       */
#define OP_Prev           39 /* jump                                       */
#define OP_Next           40 /* jump                                       */

#define OP_IdxLE          41 /* jump, synopsis: key=r[P3@P4]               */
#define OP_IdxGT          42 /* jump, synopsis: key=r[P3@P4]               */
#define OP_Or             43 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */
#define OP_And            44 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */
#define OP_IdxLT          45 /* jump, synopsis: key=r[P3@P4]               */
#define OP_IdxGE          46 /* jump, synopsis: key=r[P3@P4]               */
#define OP_RowSetRead     47 /* jump, synopsis: r[P3]=rowset(P1)           */
#define OP_RowSetTest     48 /* jump, synopsis: if r[P3] in rowset(P1) goto P2 */
#define OP_Program        49 /* jump0                                      */
#define OP_FkIfZero       50 /* jump, synopsis: if fkctr[P1]==0 goto P2    */

#define OP_IsNull         51 /* jump, same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
#define OP_NotNull        52 /* jump, same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
#define OP_Ne             53 /* jump, same as TK_NE, synopsis: IF r[P3]!=r[P1] */
#define OP_Eq             54 /* jump, same as TK_EQ, synopsis: IF r[P3]==r[P1] */
#define OP_Gt             55 /* jump, same as TK_GT, synopsis: IF r[P3]>r[P1] */
#define OP_Le             56 /* jump, same as TK_LE, synopsis: IF r[P3]<=r[P1] */
#define OP_Lt             57 /* jump, same as TK_LT, synopsis: IF r[P3]<r[P1] */
#define OP_Ge             58 /* jump, same as TK_GE, synopsis: IF r[P3]>=r[P1] */
#define OP_ElseEq         59 /* jump, same as TK_ESCAPE                    */
#define OP_IfPos          60 /* jump, synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
#define OP_IfNotZero      61 /* jump, synopsis: if r[P1]!=0 then r[P1]--, goto P2 */
#define OP_DecrJumpZero   62 /* jump, synopsis: if (--r[P1])==0 goto P2    */
#define OP_IncrVacuum     63 /* jump                                       */
#define OP_VNext          64 /* jump                                       */
#define OP_Filter         65 /* jump, synopsis: if key(P3@P4) not in filter(P1) goto P2 */
#define OP_PureFunc       66 /* synopsis: r[P3]=func(r[P2@NP])             */
#define OP_Function       67 /* synopsis: r[P3]=func(r[P2@NP])             */
#define OP_Return         68
#define OP_EndCoroutine   69
#define OP_HaltIfNull     70 /* synopsis: if r[P3]=null halt               */
#define OP_Halt           71
#define OP_Integer        72 /* synopsis: r[P2]=P1                         */
#define OP_Int64          73 /* synopsis: r[P2]=P4                         */
#define OP_String         74 /* synopsis: r[P2]='P4' (len=P1)              */
#define OP_BeginSubrtn    75 /* synopsis: r[P2]=NULL                       */
#define OP_Null           76 /* synopsis: r[P2..P3]=NULL                   */
#define OP_SoftNull       77 /* synopsis: r[P1]=NULL                       */
#define OP_Blob           78 /* synopsis: r[P2]=P4 (len=P1)                */
#define OP_Variable       79 /* synopsis: r[P2]=parameter(P1)              */
#define OP_Move           80 /* synopsis: r[P2@P3]=r[P1@P3]                */
#define OP_Copy           81 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
#define OP_SCopy          82 /* synopsis: r[P2]=r[P1]                      */
#define OP_IntCopy        83 /* synopsis: r[P2]=r[P1]                      */
#define OP_FkCheck        84
#define OP_ResultRow      85 /* synopsis: output=r[P1@P2]                  */
#define OP_CollSeq        86
#define OP_AddImm         87 /* synopsis: r[P1]=r[P1]+P2                   */
#define OP_RealAffinity   88
#define OP_Cast           89 /* synopsis: affinity(r[P1])                  */
#define OP_Permutation    90
#define OP_Compare        91 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
#define OP_IsTrue         92 /* synopsis: r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4 */
#define OP_ZeroOrNull     93 /* synopsis: r[P2] = 0 OR NULL                */
#define OP_Offset         94 /* synopsis: r[P3] = sqlite_offset(P1)        */
#define OP_Column         95 /* synopsis: r[P3]=PX cursor P1 column P2     */
#define OP_TypeCheck      96 /* synopsis: typecheck(r[P1@P2])              */
#define OP_Affinity       97 /* synopsis: affinity(r[P1@P2])               */
#define OP_MakeRecord     98 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
#define OP_Count          99 /* synopsis: r[P2]=count()                    */
#define OP_ReadCookie    100
#define OP_SetCookie     101

#define OP_ReopenIdx     102 /* synopsis: root=P2 iDb=P3                   */
#define OP_BitAnd        103 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
#define OP_BitOr         104 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
#define OP_ShiftLeft     105 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<<r[P1] */
#define OP_ShiftRight    106 /* same as TK_RSHIFT, synopsis: r[P3]=r[P2]>>r[P1] */
#define OP_Add           107 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
#define OP_Subtract      108 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
#define OP_Multiply      109 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
#define OP_Divide        110 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
#define OP_Remainder     111 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
#define OP_Concat        112 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
#define OP_OpenRead      113 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenWrite     114 /* synopsis: root=P2 iDb=P3                   */
#define OP_BitNot        115 /* same as TK_BITNOT, synopsis: r[P2]= ~r[P1] */
#define OP_OpenDup       116
#define OP_OpenAutoindex 117 /* synopsis: nColumn=P2                       */
#define OP_String8       118 /* same as TK_STRING, synopsis: r[P2]='P4'    */
#define OP_OpenEphemeral 119 /* synopsis: nColumn=P2                       */
#define OP_SorterOpen    120
#define OP_SequenceTest  121 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
#define OP_OpenPseudo    122 /* synopsis: P3 columns in r[P2]              */
#define OP_Close         123
#define OP_ColumnsUsed   124
#define OP_SeekScan      125 /* synopsis: Scan-ahead up to P1 rows         */
#define OP_SeekHit       126 /* synopsis: set P2<=seekHit<=P3              */
#define OP_Sequence      127 /* synopsis: r[P2]=cursor[P1].ctr++           */
#define OP_NewRowid      128 /* synopsis: r[P2]=rowid                      */
#define OP_Insert        129 /* synopsis: intkey=r[P3] data=r[P2]          */
#define OP_RowCell       130
#define OP_Delete        131
#define OP_ResetCount    132
#define OP_SorterCompare 133 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
#define OP_SorterData    134 /* synopsis: r[P2]=data                       */
#define OP_RowData       135 /* synopsis: r[P2]=data                       */
#define OP_Rowid         136 /* synopsis: r[P2]=PX rowid of P1             */
#define OP_NullRow       137
#define OP_SeekEnd       138
#define OP_IdxInsert     139 /* synopsis: key=r[P2]                        */
#define OP_SorterInsert  140 /* synopsis: key=r[P2]                        */
#define OP_IdxDelete     141 /* synopsis: key=r[P2@P3]                     */
#define OP_DeferredSeek  142 /* synopsis: Move P3 to P1.rowid if needed    */
#define OP_IdxRowid      143 /* synopsis: r[P2]=rowid                      */
#define OP_FinishSeek    144
#define OP_Destroy       145
#define OP_Clear         146
#define OP_ResetSorter   147
#define OP_CreateBtree   148 /* synopsis: r[P2]=root iDb=P1 flags=P3       */
#define OP_SqlExec       149
#define OP_ParseSchema   150
#define OP_LoadAnalysis  151
#define OP_DropTable     152
#define OP_DropIndex     153

#define OP_Real          154 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
#define OP_DropTrigger   155
#define OP_IntegrityCk   156
#define OP_RowSetAdd     157 /* synopsis: rowset(P1)=r[P2]                 */
#define OP_Param         158
#define OP_FkCounter     159 /* synopsis: fkctr[P1]+=P2                    */
#define OP_MemMax        160 /* synopsis: r[P1]=max(r[P1],r[P2])           */
#define OP_OffsetLimit   161 /* synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1) */
#define OP_AggInverse    162 /* synopsis: accum=r[P3] inverse(r[P2@P5])    */
#define OP_AggStep       163 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggStep1      164 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggValue      165 /* synopsis: r[P3]=value N=P2                 */
#define OP_AggFinal      166 /* synopsis: accum=r[P1] N=P2                 */
#define OP_Expire        167
#define OP_CursorLock    168
#define OP_CursorUnlock  169
#define OP_TableLock     170 /* synopsis: iDb=P1 root=P2 write=P3          */
#define OP_VBegin        171
#define OP_VCreate       172
#define OP_VDestroy      173
#define OP_VOpen         174
#define OP_VCheck        175
#define OP_VInitIn       176 /* synopsis: r[P2]=ValueList(P1,P3)           */
#define OP_VColumn       177 /* synopsis: r[P3]=vcolumn(P2)                */
#define OP_VRename       178
#define OP_Pagecount     179
#define OP_MaxPgcnt      180
#define OP_ClrSubtype    181 /* synopsis: r[P1].subtype = 0                */
#define OP_GetSubtype    182 /* synopsis: r[P2] = r[P1].subtype            */
#define OP_SetSubtype    183 /* synopsis: r[P2].subtype = r[P1]            */
#define OP_FilterAdd     184 /* synopsis: filter(P1) += key(P3@P4)         */
#define OP_Trace         185
#define OP_CursorHint    186
#define OP_ReleaseReg    187 /* synopsis: release r[P1@P2] mask P3         */
#define OP_Noop          188
#define OP_Explain       189
#define OP_Abortable     190

/* 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        0x01  /* jump:  P2 holds jmp target */
#define OPFLG_IN1         0x02  /* in1:   P1 is an input */
#define OPFLG_IN2         0x04  /* in2:   P2 is an input */
#define OPFLG_IN3         0x08  /* in3:   P3 is an input */
#define OPFLG_OUT2        0x10  /* out2:  P2 is an output */
#define OPFLG_OUT3        0x20  /* out3:  P3 is an output */
#define OPFLG_NCYCLE      0x40  /* ncycle:Cycles count against P1 */
#define OPFLG_JUMP0       0x80  /* jump0:  P2 might be zero */
#define OPFLG_INITIALIZER {\
/*   0 */ 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x41, 0x00,\
/*   8 */ 0x81, 0x01, 0x01, 0x81, 0x83, 0x83, 0x01, 0x01,\
/*  16 */ 0x03, 0x03, 0x01, 0x12, 0x01, 0xc9, 0xc9, 0xc9,\
/*  24 */ 0xc9, 0x01, 0x49, 0x49, 0x49, 0x49, 0xc9, 0x49,\
/*  32 */ 0xc1, 0x01, 0x41, 0x41, 0xc1, 0x01, 0x01, 0x41,\
/*  40 */ 0x41, 0x41, 0x41, 0x26, 0x26, 0x41, 0x41, 0x23,\
/*  48 */ 0x0b, 0x81, 0x01, 0x03, 0x03, 0x0b, 0x0b, 0x0b,\
/*  56 */ 0x0b, 0x0b, 0x0b, 0x01, 0x03, 0x03, 0x03, 0x01,\
/*  64 */ 0x41, 0x01, 0x00, 0x00, 0x02, 0x02, 0x08, 0x00,\
/*  72 */ 0x10, 0x10, 0x10, 0x00, 0x10, 0x00, 0x10, 0x10,\
/*  80 */ 0x00, 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x02,\
/*  88 */ 0x02, 0x02, 0x00, 0x00, 0x12, 0x1e, 0x20, 0x40,\
/*  96 */ 0x00, 0x00, 0x00, 0x10, 0x10, 0x00, 0x40, 0x26,\
/* 104 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,\
/* 112 */ 0x26, 0x40, 0x00, 0x12, 0x40, 0x40, 0x10, 0x40,\
/* 120 */ 0x00, 0x00, 0x00, 0x40, 0x00, 0x40, 0x40, 0x10,\
/* 128 */ 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00,\
/* 136 */ 0x50, 0x00, 0x40, 0x04, 0x04, 0x00, 0x40, 0x50,\
/* 144 */ 0x40, 0x10, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,\
/* 152 */ 0x00, 0x00, 0x10, 0x00, 0x00, 0x06, 0x10, 0x00,\
/* 160 */ 0x04, 0x1a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 168 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x10,\
/* 176 */ 0x50, 0x40, 0x00, 0x10, 0x10, 0x02, 0x12, 0x12,\
/* 184 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,}

/* The resolve3P2Values() routine is able to run faster if it knows
** the value of the largest JUMP opcode.  The smaller the maximum
** JUMP opcode the better, so the mkopcodeh.tcl script that
** generated this include file strives to group all JUMP opcodes
** together near the beginning of the list.
*/
#define SQLITE_MX_JUMP_OPCODE  65  /* Maximum JUMP opcode */

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

/*
** Additional non-public SQLITE_PREPARE_* flags
*/

   /* TH3 expects this value  ^^^^^^^^^^ See flatten04.test */
#define SQLITE_IndexedExpr    0x01000000 /* Pull exprs from index when able */
#define SQLITE_Coroutines     0x02000000 /* Co-routines for subqueries */
#define SQLITE_NullUnusedCols 0x04000000 /* NULL unused columns in subqueries */
#define SQLITE_OnePass        0x08000000 /* Single-pass DELETE and UPDATE */
#define SQLITE_OrderBySubq    0x10000000 /* ORDER BY in subquery helps outer */
#define SQLITE_StarQuery      0x20000000 /* Heurists for star queries */
#define SQLITE_ExistsToJoin   0x40000000 /* The EXISTS-to-JOIN optimization */
#define SQLITE_AllOpts        0xffffffff /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
#define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)

  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */
  unsigned bNoQuery:1;     /* Do not use this index to optimize queries */
  unsigned bAscKeyBug:1;   /* True if the bba7b69f9849b5bf bug applies */

  unsigned bHasVCol:1;     /* Index references one or more VIRTUAL columns */
  unsigned bHasExpr:1;     /* Index contains an expression, either a literal
                           ** expression, or a reference to a VIRTUAL column */
#ifdef SQLITE_ENABLE_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int mxSample;            /* Number of slots allocated to aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */

    unsigned isUsing :1;       /* u3.pUsing is valid */
    unsigned isOn :1;          /* u3.pOn was once valid and non-NULL */
    unsigned isSynthUsing :1;  /* u3.pUsing is synthesized from NATURAL */
    unsigned isNestedFrom :1;  /* pSelect is a SF_NestedFrom subquery */
    unsigned rowidUsed :1;     /* The ROWID of this table is referenced */
    unsigned fixedSchema :1;   /* Uses u4.pSchema, not u4.zDatabase */
    unsigned hadSchema :1;     /* Had u4.zDatabase before u4.pSchema */
    unsigned fromExists :1;    /* Comes from WHERE EXISTS(...) */
  } fg;
  int iCursor;      /* The VDBE cursor number used to access this table */
  Bitmask colUsed;  /* Bit N set if column N used. Details above for N>62 */
  union {
    char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
    ExprList *pFuncArg;  /* Arguments to table-valued-function */
    u32 nRow;            /* Number of rows in a VALUES clause */

  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
  u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
  u8 mayAbort;         /* True if statement may throw an ABORT exception */
  u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
  u8 disableLookaside; /* Number of times lookaside has been disabled */
  u8 prepFlags;        /* SQLITE_PREPARE_* flags */
  u8 withinRJSubrtn;   /* Nesting level for RIGHT JOIN body subroutines */
  u8 bHasExists;       /* Has a correlated "EXISTS (SELECT ....)" expression */
  u8 mSubrtnSig;       /* mini Bloom filter on available SubrtnSig.selId */
  u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
  u8 bReturning;       /* Coding a RETURNING trigger */
  u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
  u8 disableTriggers;  /* True to disable triggers */
#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  u8 earlyCleanup;     /* OOM inside sqlite3ParserAddCleanup() */

    /*  30 */ "SeekRowid"        OpHelp("intkey=r[P3]"),
    /*  31 */ "NotExists"        OpHelp("intkey=r[P3]"),
    /*  32 */ "Last"             OpHelp(""),
    /*  33 */ "IfSizeBetween"    OpHelp(""),
    /*  34 */ "SorterSort"       OpHelp(""),
    /*  35 */ "Sort"             OpHelp(""),
    /*  36 */ "Rewind"           OpHelp(""),
    /*  37 */ "IfEmpty"          OpHelp("if( empty(P1) ) goto P2"),
    /*  38 */ "SorterNext"       OpHelp(""),
    /*  39 */ "Prev"             OpHelp(""),
    /*  40 */ "Next"             OpHelp(""),
    /*  41 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
    /*  42 */ "IdxGT"            OpHelp("key=r[P3@P4]"),

    /*  43 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),
    /*  44 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),
    /*  45 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
    /*  46 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
    /*  47 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
    /*  48 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
    /*  49 */ "Program"          OpHelp(""),
    /*  50 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),

    /*  51 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
    /*  52 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
    /*  53 */ "Ne"               OpHelp("IF r[P3]!=r[P1]"),
    /*  54 */ "Eq"               OpHelp("IF r[P3]==r[P1]"),
    /*  55 */ "Gt"               OpHelp("IF r[P3]>r[P1]"),
    /*  56 */ "Le"               OpHelp("IF r[P3]<=r[P1]"),
    /*  57 */ "Lt"               OpHelp("IF r[P3]<r[P1]"),
    /*  58 */ "Ge"               OpHelp("IF r[P3]>=r[P1]"),
    /*  59 */ "ElseEq"           OpHelp(""),
    /*  60 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
    /*  61 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]--, goto P2"),
    /*  62 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
    /*  63 */ "IncrVacuum"       OpHelp(""),
    /*  64 */ "VNext"            OpHelp(""),
    /*  65 */ "Filter"           OpHelp("if key(P3@P4) not in filter(P1) goto P2"),
    /*  66 */ "PureFunc"         OpHelp("r[P3]=func(r[P2@NP])"),
    /*  67 */ "Function"         OpHelp("r[P3]=func(r[P2@NP])"),
    /*  68 */ "Return"           OpHelp(""),
    /*  69 */ "EndCoroutine"     OpHelp(""),
    /*  70 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
    /*  71 */ "Halt"             OpHelp(""),
    /*  72 */ "Integer"          OpHelp("r[P2]=P1"),
    /*  73 */ "Int64"            OpHelp("r[P2]=P4"),
    /*  74 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
    /*  75 */ "BeginSubrtn"      OpHelp("r[P2]=NULL"),
    /*  76 */ "Null"             OpHelp("r[P2..P3]=NULL"),
    /*  77 */ "SoftNull"         OpHelp("r[P1]=NULL"),
    /*  78 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
    /*  79 */ "Variable"         OpHelp("r[P2]=parameter(P1)"),
    /*  80 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
    /*  81 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
    /*  82 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
    /*  83 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),
    /*  84 */ "FkCheck"          OpHelp(""),
    /*  85 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
    /*  86 */ "CollSeq"          OpHelp(""),
    /*  87 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
    /*  88 */ "RealAffinity"     OpHelp(""),
    /*  89 */ "Cast"             OpHelp("affinity(r[P1])"),
    /*  90 */ "Permutation"      OpHelp(""),
    /*  91 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
    /*  92 */ "IsTrue"           OpHelp("r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4"),
    /*  93 */ "ZeroOrNull"       OpHelp("r[P2] = 0 OR NULL"),
    /*  94 */ "Offset"           OpHelp("r[P3] = sqlite_offset(P1)"),
    /*  95 */ "Column"           OpHelp("r[P3]=PX cursor P1 column P2"),
    /*  96 */ "TypeCheck"        OpHelp("typecheck(r[P1@P2])"),
    /*  97 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
    /*  98 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
    /*  99 */ "Count"            OpHelp("r[P2]=count()"),
    /* 100 */ "ReadCookie"       OpHelp(""),
    /* 101 */ "SetCookie"        OpHelp(""),
    /* 102 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),

    /* 103 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
    /* 104 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
    /* 105 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<<r[P1]"),
    /* 106 */ "ShiftRight"       OpHelp("r[P3]=r[P2]>>r[P1]"),
    /* 107 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
    /* 108 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
    /* 109 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
    /* 110 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
    /* 111 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
    /* 112 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
    /* 113 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
    /* 114 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),

    /* 115 */ "BitNot"           OpHelp("r[P2]= ~r[P1]"),
    /* 116 */ "OpenDup"          OpHelp(""),
    /* 117 */ "OpenAutoindex"    OpHelp("nColumn=P2"),

    /* 118 */ "String8"          OpHelp("r[P2]='P4'"),
    /* 119 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
    /* 120 */ "SorterOpen"       OpHelp(""),
    /* 121 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
    /* 122 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
    /* 123 */ "Close"            OpHelp(""),
    /* 124 */ "ColumnsUsed"      OpHelp(""),
    /* 125 */ "SeekScan"         OpHelp("Scan-ahead up to P1 rows"),
    /* 126 */ "SeekHit"          OpHelp("set P2<=seekHit<=P3"),
    /* 127 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),
    /* 128 */ "NewRowid"         OpHelp("r[P2]=rowid"),
    /* 129 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
    /* 130 */ "RowCell"          OpHelp(""),
    /* 131 */ "Delete"           OpHelp(""),
    /* 132 */ "ResetCount"       OpHelp(""),
    /* 133 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
    /* 134 */ "SorterData"       OpHelp("r[P2]=data"),
    /* 135 */ "RowData"          OpHelp("r[P2]=data"),
    /* 136 */ "Rowid"            OpHelp("r[P2]=PX rowid of P1"),
    /* 137 */ "NullRow"          OpHelp(""),
    /* 138 */ "SeekEnd"          OpHelp(""),
    /* 139 */ "IdxInsert"        OpHelp("key=r[P2]"),
    /* 140 */ "SorterInsert"     OpHelp("key=r[P2]"),
    /* 141 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),
    /* 142 */ "DeferredSeek"     OpHelp("Move P3 to P1.rowid if needed"),
    /* 143 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
    /* 144 */ "FinishSeek"       OpHelp(""),
    /* 145 */ "Destroy"          OpHelp(""),
    /* 146 */ "Clear"            OpHelp(""),
    /* 147 */ "ResetSorter"      OpHelp(""),
    /* 148 */ "CreateBtree"      OpHelp("r[P2]=root iDb=P1 flags=P3"),
    /* 149 */ "SqlExec"          OpHelp(""),
    /* 150 */ "ParseSchema"      OpHelp(""),
    /* 151 */ "LoadAnalysis"     OpHelp(""),
    /* 152 */ "DropTable"        OpHelp(""),
    /* 153 */ "DropIndex"        OpHelp(""),

    /* 154 */ "Real"             OpHelp("r[P2]=P4"),
    /* 155 */ "DropTrigger"      OpHelp(""),
    /* 156 */ "IntegrityCk"      OpHelp(""),
    /* 157 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
    /* 158 */ "Param"            OpHelp(""),
    /* 159 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
    /* 160 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
    /* 161 */ "OffsetLimit"      OpHelp("if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)"),
    /* 162 */ "AggInverse"       OpHelp("accum=r[P3] inverse(r[P2@P5])"),
    /* 163 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 164 */ "AggStep1"         OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 165 */ "AggValue"         OpHelp("r[P3]=value N=P2"),
    /* 166 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
    /* 167 */ "Expire"           OpHelp(""),
    /* 168 */ "CursorLock"       OpHelp(""),
    /* 169 */ "CursorUnlock"     OpHelp(""),
    /* 170 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
    /* 171 */ "VBegin"           OpHelp(""),
    /* 172 */ "VCreate"          OpHelp(""),
    /* 173 */ "VDestroy"         OpHelp(""),
    /* 174 */ "VOpen"            OpHelp(""),
    /* 175 */ "VCheck"           OpHelp(""),
    /* 176 */ "VInitIn"          OpHelp("r[P2]=ValueList(P1,P3)"),
    /* 177 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
    /* 178 */ "VRename"          OpHelp(""),
    /* 179 */ "Pagecount"        OpHelp(""),
    /* 180 */ "MaxPgcnt"         OpHelp(""),
    /* 181 */ "ClrSubtype"       OpHelp("r[P1].subtype = 0"),
    /* 182 */ "GetSubtype"       OpHelp("r[P2] = r[P1].subtype"),
    /* 183 */ "SetSubtype"       OpHelp("r[P2].subtype = r[P1]"),
    /* 184 */ "FilterAdd"        OpHelp("filter(P1) += key(P3@P4)"),
    /* 185 */ "Trace"            OpHelp(""),
    /* 186 */ "CursorHint"       OpHelp(""),
    /* 187 */ "ReleaseReg"       OpHelp("release r[P1@P2] mask P3"),
    /* 188 */ "Noop"             OpHelp(""),
    /* 189 */ "Explain"          OpHelp(""),
    /* 190 */ "Abortable"        OpHelp(""),
  };
  return azName[i];
}
#endif

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

  int iEnd = iStart + iSize;            /* First byte past the iStart buffer */
  unsigned char *data = pPage->aData;   /* Page content */
  u8 *pTmp;                             /* Temporary ptr into data[] */

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
  assert( CORRUPT_DB || iEnd <= (int)pPage->pBt->usableSize );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( iSize>=4 );   /* Minimum cell size is 4 */
  assert( CORRUPT_DB || iStart<=(int)pPage->pBt->usableSize-4 );

  /* The list of freeblocks must be in ascending order.  Find the
  ** spot on the list where iStart should be inserted.
  */
  hdr = pPage->hdrOffset;
  iPtr = hdr + 1;
  if( data[iPtr+1]==0 && data[iPtr]==0 ){

  }else if( rc==SQLITE_EMPTY ){
    assert( pCur->pgnoRoot==0 || (pCur->pPage!=0 && pCur->pPage->nCell==0) );
    *pRes = 1;
    rc = SQLITE_OK;
  }
  return rc;
}

/* Set *pRes to 1 (true) if the BTree pointed to by cursor pCur contains zero
** rows of content.  Set *pRes to 0 (false) if the table contains content.
** Return SQLITE_OK on success or some error code (ex: SQLITE_NOMEM) if
** something goes wrong.
*/
SQLITE_PRIVATE int sqlite3BtreeIsEmpty(BtCursor *pCur, int *pRes){
  int rc;

  assert( cursorOwnsBtShared(pCur) );
  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
  if( pCur->eState==CURSOR_VALID ){
    *pRes = 0;
    return SQLITE_OK;
  }
  rc = moveToRoot(pCur);
  if( rc==SQLITE_EMPTY ){
    *pRes = 1;
    rc = SQLITE_OK;
  }else{
    *pRes = 0;
  }
  return rc;
}

#ifdef SQLITE_DEBUG
/* The cursors is CURSOR_VALID and has BTCF_AtLast set.  Verify that
** this flags are true for a consistent database.
**
** This routine is is called from within assert() statements only.
** It is an internal verification routine and does not appear in production

  pC->nullRow = (u8)res;
  if( pOp->p2>0 ){
    VdbeBranchTaken(res!=0,2);
    if( res ) goto jump_to_p2;
  }
  break;
}

/* Opcode: IfEmpty P1 P2 * * *
** Synopsis: if( empty(P1) ) goto P2
**
** Check to see if the b-tree table that cursor P1 references is empty
** and jump to P2 if it is.
*/
case OP_IfEmpty: {        /* jump */
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p2>=0 && pOp->p2<p->nOp );

  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr );
  rc = sqlite3BtreeIsEmpty(pCrsr, &res);
  if( rc ) goto abort_due_to_error;
  VdbeBranchTaken(res!=0,2);
  if( res ) goto jump_to_p2;
  break;
}

/* Opcode: Next P1 P2 P3 * P5
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index.  If there are no more key/value pairs then fall through
** to the following instruction.  But if the cursor advance was successful,
** jump immediately to P2.

case OP_VOpen: {             /* ncycle */
  VdbeCursor *pCur;
  sqlite3_vtab_cursor *pVCur;
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;

  assert( p->bIsReader );
  pCur = p->apCsr[pOp->p1];
  if( pCur!=0
   && ALWAYS( pCur->eCurType==CURTYPE_VTAB )
   && ALWAYS( pCur->uc.pVCur->pVtab==pOp->p4.pVtab->pVtab )
  ){
    /* This opcode is a no-op if the cursor is already open */
    break;
  }
  pVCur = 0;
  pVtab = pOp->p4.pVtab->pVtab;
  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
    rc = SQLITE_LOCKED;
    goto abort_due_to_error;
  }
  pModule = pVtab->pModule;

static int blobReadWrite(
  sqlite3_blob *pBlob,
  void *z,
  int n,
  int iOffset,
  int (*xCall)(BtCursor*, u32, u32, void*)
){
  int rc = SQLITE_OK;
  Incrblob *p = (Incrblob *)pBlob;
  Vdbe *v;
  sqlite3 *db;

  if( p==0 ) return SQLITE_MISUSE_BKPT;
  db = p->db;
  sqlite3_mutex_enter(db->mutex);

      ** are not easily obtainable. And for the sessions module, an
      ** SQLITE_UPDATE where the PK columns do not change is handled in the
      ** same way as an SQLITE_DELETE (the SQLITE_DELETE code is actually
      ** slightly more efficient). Since you cannot write to a PK column
      ** using the incremental-blob API, this works. For the sessions module
      ** anyhow.
      */
      if( sqlite3BtreeCursorIsValidNN(p->pCsr)==0 ){
        /* If the cursor is not currently valid, try to reseek it. This
        ** always either fails or finds the correct row - the cursor will
        ** have been marked permanently CURSOR_INVALID if the open row has
        ** been deleted.  */
        int bDiff = 0;
        rc = sqlite3BtreeCursorRestore(p->pCsr, &bDiff);
        assert( bDiff==0 || sqlite3BtreeCursorIsValidNN(p->pCsr)==0 );
      }
      if( sqlite3BtreeCursorIsValidNN(p->pCsr) ){
        sqlite3_int64 iKey;
        iKey = sqlite3BtreeIntegerKey(p->pCsr);
        assert( v->apCsr[0]!=0 );
        assert( v->apCsr[0]->eCurType==CURTYPE_BTREE );
        sqlite3VdbePreUpdateHook(
            v, v->apCsr[0], SQLITE_DELETE, p->zDb, p->pTab, iKey, -1, p->iCol
        );
      }
    }
    if( rc==SQLITE_OK ){
      rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
    }
#else
    rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
#endif

    sqlite3BtreeLeaveCursor(p->pCsr);
    if( rc==SQLITE_ABORT ){
      sqlite3VdbeFinalize(v);
      p->pStmt = 0;
    }else{
      v->rc = rc;
    }

      }
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function
      */
      return WRC_Prune;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT:
#endif
    case TK_IN: {
      testcase( pExpr->op==TK_IN );
      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      if( ExprUseXSelect(pExpr) ){
        int nRef = pNC->nRef;
        testcase( pNC->ncFlags & NC_IsCheck );
        testcase( pNC->ncFlags & NC_PartIdx );
        testcase( pNC->ncFlags & NC_IdxExpr );
        testcase( pNC->ncFlags & NC_GenCol );
        assert( pExpr->x.pSelect );
        if( pExpr->op==TK_EXISTS )  pParse->bHasExists = 1;
        if( pNC->ncFlags & NC_SelfRef ){
          notValidImpl(pParse, pNC, "subqueries", pExpr, pExpr);
        }else{
          sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
        }
        assert( pNC->nRef>=nRef );
        if( nRef!=pNC->nRef ){

  sqlite3 *db = pParse->db;
  if( pLeft==0  ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;
  }else{
    u32 f = pLeft->flags | pRight->flags;
    if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse|EP_HasFunc))==EP_IsFalse
     && !IN_RENAME_OBJECT
    ){
      sqlite3ExprDeferredDelete(pParse, pLeft);
      sqlite3ExprDeferredDelete(pParse, pRight);
      return sqlite3Expr(db, TK_INTEGER, "0");
    }else{
      return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);

  ** If the left operand contains a (possibly expensive) subquery and the
  ** right operand does not and the right operation might be NULL,
  ** then compute the right operand first and do an IsNull jump if the
  ** right operand evalutes to NULL.
  */
  if( exprEvalRhsFirst(pExpr) && sqlite3ExprCanBeNull(pExpr->pRight) ){
    r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
    addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r2);
    VdbeComment((v, "skip left operand"));
    VdbeCoverage(v);
  }else{
    r2 = 0; /* Silence a false-positive uninit-var warning in MSVC */
    addrIsNull = 0;
  }
  r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, pFree1);
  if( addrIsNull==0 ){
    /*
    ** If the right operand contains a subquery and the left operand does not
    ** and the left operand might be NULL, then check the left operand do
    ** an IsNull check on the left operand before computing the right
    ** operand.
    */
    if( ExprHasProperty(pExpr->pRight, EP_Subquery)
     && sqlite3ExprCanBeNull(pExpr->pLeft)
    ){
      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r1);
      VdbeComment((v, "skip right operand"));
      VdbeCoverage(v);
    }
    r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
  }
  *pR1 = r1;
  *pR2 = r2;
  return addrIsNull;
}

    VdbeComment((v, "Init subquery result"));
  }else{
    dest.eDest = SRT_Exists;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
    VdbeComment((v, "Init EXISTS result"));
  }
  if( pSel->pLimit ){
    /* The subquery already has a limit.  If the pre-existing limit X is
    ** not already integer value 1 or 0, then make the new limit X<>0 so that
    ** the new limit is either 1 or 0 */
    Expr *pLeft = pSel->pLimit->pLeft;
    if( ExprHasProperty(pLeft, EP_IntValue)==0
     || (pLeft->u.iValue!=1 && pLeft->u.iValue!=0)
    ){
      sqlite3 *db = pParse->db;
      pLimit = sqlite3Expr(db, TK_INTEGER, "0");
      if( pLimit ){
        pLimit->affExpr = SQLITE_AFF_NUMERIC;
        pLimit = sqlite3PExpr(pParse, TK_NE,
            sqlite3ExprDup(db, pLeft, 0), pLimit);
      }
      sqlite3ExprDeferredDelete(pParse, pLeft);
      pSel->pLimit->pLeft = pLimit;
    }
  }else{
    /* If there is no pre-existing limit add a limit of 1 */
    pLimit = sqlite3Expr(pParse->db, TK_INTEGER, "1");
    pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
  }
  pSel->iLimit = 0;
  if( sqlite3Select(pParse, pSel, &dest) ){

      sqlite3VdbeAddOp3(v, op, r2, r1, target);
      testcase( regFree1==0 );
      testcase( regFree2==0 );
      if( addrIsNull ){
        sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+2);
        sqlite3VdbeJumpHere(v, addrIsNull);
        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
        VdbeComment((v, "short-circut value"));
      }
      break;
    }
    case TK_UMINUS: {
      Expr *pLeft = pExpr->pLeft;
      assert( pLeft );
      if( pLeft->op==TK_INTEGER ){

      pIndex->uniqNotNull = 0;
      pIndex->bHasExpr = 1;
    }else{
      j = pCExpr->iColumn;
      assert( j<=0x7fff );
      if( j<0 ){
        j = pTab->iPKey;

      }else{
        if( pTab->aCol[j].notNull==0 ){
          pIndex->uniqNotNull = 0;
        }
        if( pTab->aCol[j].colFlags & COLFLAG_VIRTUAL ){
          pIndex->bHasVCol = 1;
          pIndex->bHasExpr = 1;

/*
** Append the contents of SrcList p2 to SrcList p1 and return the resulting
** SrcList. Or, if an error occurs, return NULL. In all cases, p1 and p2
** are deleted by this function.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendList(Parse *pParse, SrcList *p1, SrcList *p2){
  assert( p1 );
  assert( p2 || pParse->nErr );
  assert( p2==0 || p2->nSrc>=1 );
  testcase( p1->nSrc==0 );
  if( p2 ){
    int nOld = p1->nSrc;
    SrcList *pNew = sqlite3SrcListEnlarge(pParse, p1, p2->nSrc, nOld);
    if( pNew==0 ){
      sqlite3SrcListDelete(pParse->db, p2);
    }else{
      p1 = pNew;
      memcpy(&p1->a[nOld], p2->a, p2->nSrc*sizeof(SrcItem));
      assert( nOld==1 || (p2->a[0].fg.jointype & JT_LTORJ)==0 );
      assert( p1->nSrc>=1 );
      p1->a[0].fg.jointype |= (JT_LTORJ & p2->a[0].fg.jointype);
      sqlite3DbFree(pParse->db, p2);

    }
  }
  return p1;
}

/*
** Add the list of function arguments to the SrcList entry for a

*/
static int tableAndColumnIndex(
  SrcList *pSrc,       /* Array of tables to search */
  int iStart,          /* First member of pSrc->a[] to check */
  int iEnd,            /* Last member of pSrc->a[] to check */
  const char *zCol,    /* Name of the column we are looking for */
  int *piTab,          /* Write index of pSrc->a[] here */
  int *piCol,          /* Write index of pSrc->a[*piTab].pSTab->aCol[] here */
  int bIgnoreHidden    /* Ignore hidden columns */
){
  int i;               /* For looping over tables in pSrc */
  int iCol;            /* Index of column matching zCol */

  assert( iEnd<pSrc->nSrc );
  assert( iStart>=0 );

      case TK_EXCEPT:
      case TK_UNION: {
        int unionTab;    /* Cursor number of the temp table holding result */
        u8 op = 0;       /* One of the SRT_ operations to apply to self */
        int priorOp;     /* The SRT_ operation to apply to prior selects */
        Expr *pLimit;    /* Saved values of p->nLimit  */
        int addr;
        int emptyBypass = 0;   /* IfEmpty opcode to bypass RHS */
        SelectDest uniondest;


        testcase( p->op==TK_EXCEPT );
        testcase( p->op==TK_UNION );
        priorOp = SRT_Union;
        if( dest.eDest==priorOp ){
          /* We can reuse a temporary table generated by a SELECT to our
          ** right.

          goto multi_select_end;
        }

        /* Code the current SELECT statement
        */
        if( p->op==TK_EXCEPT ){
          op = SRT_Except;
          emptyBypass = sqlite3VdbeAddOp1(v, OP_IfEmpty, unionTab);
          VdbeCoverage(v);
        }else{
          assert( p->op==TK_UNION );
          op = SRT_Union;
        }
        p->pPrior = 0;
        pLimit = p->pLimit;
        p->pLimit = 0;
        uniondest.eDest = op;
        ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
                          sqlite3SelectOpName(p->op)));
        TREETRACE(0x200, pParse, p, ("multiSelect EXCEPT/UNION right...\n"));
        rc = sqlite3Select(pParse, p, &uniondest);
        testcase( rc!=SQLITE_OK );
        assert( p->pOrderBy==0 );
        pDelete = p->pPrior;
        p->pPrior = pPrior;
        p->pOrderBy = 0;
        if( p->op==TK_UNION ){
          p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
        }
        if( emptyBypass ) sqlite3VdbeJumpHere(v, emptyBypass);
        sqlite3ExprDelete(db, p->pLimit);
        p->pLimit = pLimit;
        p->iLimit = 0;
        p->iOffset = 0;

        /* Convert the data in the temporary table into whatever form
        ** it is that we currently need.

      default: assert( p->op==TK_INTERSECT ); {
        int tab1, tab2;
        int iCont, iBreak, iStart;
        Expr *pLimit;
        int addr;
        SelectDest intersectdest;
        int r1;
        int emptyBypass;

        /* INTERSECT is different from the others since it requires
        ** two temporary tables.  Hence it has its own case.  Begin
        ** by allocating the tables we will need.
        */
        tab1 = pParse->nTab++;
        tab2 = pParse->nTab++;

        */
        sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);
        TREETRACE(0x400, pParse, p, ("multiSelect INTERSECT left...\n"));
        rc = sqlite3Select(pParse, pPrior, &intersectdest);
        if( rc ){
          goto multi_select_end;
        }
        emptyBypass = sqlite3VdbeAddOp1(v, OP_IfEmpty, tab1); VdbeCoverage(v);

        /* Code the current SELECT into temporary table "tab2"
        */
        addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
        assert( p->addrOpenEphm[1] == -1 );
        p->addrOpenEphm[1] = addr;
        p->pPrior = 0;

        ** tables.
        */
        if( rc ) break;
        assert( p->pEList );
        iBreak = sqlite3VdbeMakeLabel(pParse);
        iCont = sqlite3VdbeMakeLabel(pParse);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp1(v, OP_Rewind, tab1);
        r1 = sqlite3GetTempReg(pParse);
        iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
        sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);
        VdbeCoverage(v);
        sqlite3ReleaseTempReg(pParse, r1);
        selectInnerLoop(pParse, p, tab1,
                        0, 0, &dest, iCont, iBreak);
        sqlite3VdbeResolveLabel(v, iCont);
        sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);
        sqlite3VdbeResolveLabel(v, iBreak);
        sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
        sqlite3VdbeJumpHere(v, emptyBypass);
        sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
        break;
      }
    }

  #ifndef SQLITE_OMIT_EXPLAIN
    if( p->pNext==0 ){

** when processing a non-matched row of the left.
*/
typedef struct SubstContext {
  Parse *pParse;            /* The parsing context */
  int iTable;               /* Replace references to this table */
  int iNewTable;            /* New table number */
  int isOuterJoin;          /* Add TK_IF_NULL_ROW opcodes on each replacement */
  int nSelDepth;            /* Depth of sub-query recursion.  Top==1 */
  ExprList *pEList;         /* Replacement expressions */
  ExprList *pCList;         /* Collation sequences for replacement expr */
} SubstContext;

/* Forward Declarations */
static void substExprList(SubstContext*, ExprList*);
static void substSelect(SubstContext*, Select*, int);

        sqlite3ExprDelete(db, pExpr);
        pExpr = pNew;
      }
    }
  }else{
    if( pExpr->op==TK_IF_NULL_ROW && pExpr->iTable==pSubst->iTable ){
      pExpr->iTable = pSubst->iNewTable;
    }
    if( pExpr->op==TK_AGG_FUNCTION && pExpr->op2>=pSubst->nSelDepth ){
      pExpr->op2--;
    }
    pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);
    pExpr->pRight = substExpr(pSubst, pExpr->pRight);
    if( ExprUseXSelect(pExpr) ){
      substSelect(pSubst, pExpr->x.pSelect, 1);
    }else{
      substExprList(pSubst, pExpr->x.pList);

  Select *p,            /* SELECT statement in which to make substitutions */
  int doPrior           /* Do substitutes on p->pPrior too */
){
  SrcList *pSrc;
  SrcItem *pItem;
  int i;
  if( !p ) return;
  pSubst->nSelDepth++;
  do{
    substExprList(pSubst, p->pEList);
    substExprList(pSubst, p->pGroupBy);
    substExprList(pSubst, p->pOrderBy);
    p->pHaving = substExpr(pSubst, p->pHaving);
    p->pWhere = substExpr(pSubst, p->pWhere);
    pSrc = p->pSrc;
    assert( pSrc!=0 );
    for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
      if( pItem->fg.isSubquery ){
        substSelect(pSubst, pItem->u4.pSubq->pSelect, 1);
      }
      if( pItem->fg.isTabFunc ){
        substExprList(pSubst, pItem->u1.pFuncArg);
      }
    }
  }while( doPrior && (p = p->pPrior)!=0 );
  pSubst->nSelDepth--;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/*
** pSelect is a SELECT statement and pSrcItem is one item in the FROM
** clause of that SELECT.

  }

  /* Defer deleting the Table object associated with the
  ** subquery until code generation is
  ** complete, since there may still exist Expr.pTab entries that
  ** refer to the subquery even after flattening.  Ticket #3346.
  **
  ** pSubitem->pSTab is always non-NULL by test restrictions and tests above.
  */
  if( ALWAYS(pSubitem->pSTab!=0) ){
    Table *pTabToDel = pSubitem->pSTab;
    if( pTabToDel->nTabRef==1 ){
      Parse *pToplevel = sqlite3ParseToplevel(pParse);
      sqlite3ParserAddCleanup(pToplevel, sqlite3DeleteTableGeneric, pTabToDel);
      testcase( pToplevel->earlyCleanup );

    }
    if( db->mallocFailed==0 ){
      SubstContext x;
      x.pParse = pParse;
      x.iTable = iParent;
      x.iNewTable = iNewParent;
      x.isOuterJoin = isOuterJoin;
      x.nSelDepth = 0;
      x.pEList = pSub->pEList;
      x.pCList = findLeftmostExprlist(pSub);
      substSelect(&x, pParent, 0);
    }

    /* The flattened query is a compound if either the inner or the
    ** outer query is a compound. */

      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      unsetJoinExpr(pNew, -1, 1);
      x.pParse = pParse;
      x.iTable = pSrc->iCursor;
      x.iNewTable = pSrc->iCursor;
      x.isOuterJoin = 0;
      x.nSelDepth = 0;
      x.pEList = pSubq->pEList;
      x.pCList = findLeftmostExprlist(pSubq);
      pNew = substExpr(&x, pNew);
#ifndef SQLITE_OMIT_WINDOWFUNC
      if( pSubq->pWin && 0==pushDownWindowCheck(pParse, pSubq, pNew) ){
        /* Restriction 6c has prevented push-down in this case */
        sqlite3ExprDelete(pParse->db, pNew);

/*
** This function checks if argument pFrom refers to a CTE declared by
** a WITH clause on the stack currently maintained by the parser (on the
** pParse->pWith linked list).  And if currently processing a CTE
** CTE expression, through routine checks to see if the reference is
** a recursive reference to the CTE.
**
** If pFrom matches a CTE according to either of these two above, pFrom->pSTab
** and other fields are populated accordingly.
**
** Return 0 if no match is found.
** Return 1 if a match is found.
** Return 2 if an error condition is detected.
*/
static int resolveFromTermToCte(

    if( i==0 ) break;
    i--;
    pItem--;
    if( pItem->fg.isSubquery ) return 0;                          /* (1c-i) */
  }
  return 1;
}

/*
** Argument pWhere is the WHERE clause belonging to SELECT statement p. This
** function attempts to transform expressions of the form:
**
**     EXISTS (SELECT ...)
**
** into joins. For example, given
**
**    CREATE TABLE sailors(sid INTEGER PRIMARY KEY, name TEXT);
**    CREATE TABLE reserves(sid INT, day DATE, PRIMARY KEY(sid, day));
**
**    SELECT name FROM sailors AS S WHERE EXISTS (
**      SELECT * FROM reserves AS R WHERE S.sid = R.sid AND R.day = '2022-10-25'
**    );
**
** the SELECT statement may be transformed as follows:
**
**    SELECT name FROM sailors AS S, reserves AS R
**      WHERE S.sid = R.sid AND R.day = '2022-10-25';
**
** **Approximately**.  Really, we have to ensure that the FROM-clause term
** that was formerly inside the EXISTS is only executed once.  This is handled
** by setting the SrcItem.fg.fromExists flag, which then causes code in
** the where.c file to exit the corresponding loop after the first successful
** match (if any).
*/
static SQLITE_NOINLINE void existsToJoin(
  Parse *pParse,  /* Parsing context */
  Select *p,      /* The SELECT statement being optimized */
  Expr *pWhere    /* part of the WHERE clause currently being examined */
){
  if( pWhere
   && !ExprHasProperty(pWhere, EP_OuterON|EP_InnerON)
   && p->pSrc->nSrc<BMS
   && pParse->db->mallocFailed==0
  ){
    if( pWhere->op==TK_AND ){
      Expr *pRight = pWhere->pRight;
      existsToJoin(pParse, p, pWhere->pLeft);
      existsToJoin(pParse, p, pRight);
    }
    else if( pWhere->op==TK_EXISTS ){
      Select *pSub = pWhere->x.pSelect;
      Expr *pSubWhere = pSub->pWhere;
      if( pSub->pSrc->nSrc==1
       && (pSub->selFlags & SF_Aggregate)==0
       && !pSub->pSrc->a[0].fg.isSubquery
      ){
        memset(pWhere, 0, sizeof(*pWhere));
        pWhere->op = TK_INTEGER;
        pWhere->u.iValue = 1;
        ExprSetProperty(pWhere, EP_IntValue);

        assert( p->pWhere!=0 );
        pSub->pSrc->a[0].fg.fromExists = 1;
        pSub->pSrc->a[0].fg.jointype |= JT_CROSS;
        p->pSrc = sqlite3SrcListAppendList(pParse, p->pSrc, pSub->pSrc);
        if( pSubWhere ){
          p->pWhere = sqlite3PExpr(pParse, TK_AND, p->pWhere, pSubWhere);
          pSub->pWhere = 0;
        }
        pSub->pSrc = 0;
        sqlite3ParserAddCleanup(pParse, sqlite3SelectDeleteGeneric, pSub);
#if TREETRACE_ENABLED
        if( sqlite3TreeTrace & 0x100000 ){
          TREETRACE(0x100000,pParse,p,
                    ("After EXISTS-to-JOIN optimization:\n"));
          sqlite3TreeViewSelect(0, p, 0);
        }
#endif
        existsToJoin(pParse, p, pSubWhere);
      }
    }
  }
}

/*
** Generate byte-code for the SELECT statement given in the p argument.
**
** The results are returned according to the SelectDest structure.
** See comments in sqliteInt.h for further information.
**

      sqlite3TreeViewSelect(0, p, 0);
    }
#endif
    if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
    return rc;
  }
#endif

  /* If there may be an "EXISTS (SELECT ...)" in the WHERE clause, attempt
  ** to change it into a join.  */
  if( pParse->bHasExists && OptimizationEnabled(db,SQLITE_ExistsToJoin) ){
    existsToJoin(pParse, p, p->pWhere);
    pTabList = p->pSrc;
  }

  /* Do the WHERE-clause constant propagation optimization if this is
  ** a join.  No need to spend time on this operation for non-join queries
  ** as the equivalent optimization will be handled by query planner in
  ** sqlite3WhereBegin().  tag-select-0330
  */
  if( p->pWhere!=0

      **
      ** This code copies current group by terms in b0,b1,b2,...
      ** over to a0,a1,a2.  It then calls the output subroutine
      ** and resets the aggregate accumulator registers in preparation
      ** for the next GROUP BY batch.
      */
      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
      VdbeComment((v, "output one row of %d", p->selId));
      sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);
      VdbeComment((v, "check abort flag"));
      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
      VdbeComment((v, "reset accumulator %d", p->selId));

      /* Update the aggregate accumulators based on the content of
      ** the current row
      */
      sqlite3VdbeJumpHere(v, addr1);
      updateAccumulator(pParse, iUseFlag, pAggInfo, eDist);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
      VdbeComment((v, "indicate data in accumulator %d", p->selId));

      /* End of the loop
      */
      if( groupBySort ){
        sqlite3VdbeAddOp2(v, OP_SorterNext, pAggInfo->sortingIdx,addrTopOfLoop);
        VdbeCoverage(v);
      }else{
        TREETRACE(0x2,pParse,p,("WhereEnd\n"));
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeChangeToNoop(v, addrSortingIdx);
      }
      sqlite3ExprListDelete(db, pDistinct);

      /* Output the final row of result
      */
      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
      VdbeComment((v, "output final row of %d", p->selId));

      /* Jump over the subroutines
      */
      sqlite3VdbeGoto(v, addrEnd);

      /* Generate a subroutine that outputs a single row of the result
      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
      ** is less than or equal to zero, the subroutine is a no-op.  If
      ** the processing calls for the query to abort, this subroutine
      ** increments the iAbortFlag memory location before returning in
      ** order to signal the caller to abort.
      */
      addrSetAbort = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
      VdbeComment((v, "set abort flag"));
      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
      sqlite3VdbeResolveLabel(v, addrOutputRow);
      addrOutputRow = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
      VdbeCoverage(v);
      VdbeComment((v, "Groupby result generator entry point %d", p->selId));
      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
      finalizeAggFunctions(pParse, pAggInfo);
      sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
      selectInnerLoop(pParse, p, -1, &sSort,
                      &sDistinct, pDest,
                      addrOutputRow+1, addrSetAbort);
      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
      VdbeComment((v, "end groupby result generator %d", p->selId));

      /* Generate a subroutine that will reset the group-by accumulator
      */
      sqlite3VdbeResolveLabel(v, addrReset);
      resetAccumulator(pParse, pAggInfo);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
      VdbeComment((v, "indicate accumulator %d empty", p->selId));
      sqlite3VdbeAddOp1(v, OP_Return, regReset);

      if( distFlag!=0 && eDist!=WHERE_DISTINCT_NOOP ){
        struct AggInfo_func *pF = &pAggInfo->aFunc[0];
        fixDistinctOpenEph(pParse, eDist, pF->iDistinct, pF->iDistAddr);
      }
    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */

** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
*/
struct WhereLevel {
  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
  int iTabCur;          /* The VDBE cursor used to access the table */
  int iIdxCur;          /* The VDBE cursor used to access pIdx */
  int addrBrk;          /* Jump here to break out of the loop */
  int addrHalt;         /* Abort the query due to empty table or similar */
  int addrNxt;          /* Jump here to start the next IN combination */
  int addrSkip;         /* Jump here for next iteration of skip-scan */
  int addrCont;         /* Jump here to continue with the next loop cycle */
  int addrFirst;        /* First instruction of interior of the loop */
  int addrBody;         /* Beginning of the body of this loop */
  int regBignull;       /* big-null flag reg. True if a NULL-scan is needed */
  int addrBignull;      /* Jump here for next part of big-null scan */

  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
){
#if !defined(SQLITE_DEBUG)
  if( sqlite3ParseToplevel(pParse)->explain==2 || IS_STMT_SCANSTATUS(pParse->db) )
#endif
  {
    VdbeOp *pOp = sqlite3VdbeGetOp(pParse->pVdbe, addr);

    SrcItem *pItem = &pTabList->a[pLevel->iFrom];
    sqlite3 *db = pParse->db;     /* Database handle */
    int isSearch;                 /* True for a SEARCH. False for SCAN. */
    WhereLoop *pLoop;             /* The controlling WhereLoop object */
    u32 flags;                    /* Flags that describe this loop */
#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_EXPLAIN)
    char *zMsg;                   /* Text to add to EQP output */

    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
    str.printfFlags = SQLITE_PRINTF_INTERNAL;
    sqlite3_str_appendf(&str, "%s %S%s",
       isSearch ? "SEARCH" : "SCAN",
       pItem,
       pItem->fg.fromExists ? " EXISTS" : "");
    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
      const char *zFmt = 0;
      Index *pIdx;

      assert( pLoop->u.btree.pIndex!=0 );
      pIdx = pLoop->u.btree.pIndex;
      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );

        pOrigLhs = pNew->pLeft->x.pList;
      }
      for(i=iEq; i<pLoop->nLTerm; i++){
        if( pLoop->aLTerm[i]->pExpr==pX ){
          int iField;
          assert( (pLoop->aLTerm[i]->eOperator & (WO_OR|WO_AND))==0 );
          iField = pLoop->aLTerm[i]->u.x.iField - 1;
          if( NEVER(pOrigRhs->a[iField].pExpr==0) ){
            continue; /* Duplicate PK column */
          }
          pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr);
          pOrigRhs->a[iField].pExpr = 0;
          if( pRhs ) pRhs->a[pRhs->nExpr-1].u.x.iOrderByCol = iField+1;
          if( pOrigLhs ){
            assert( pOrigLhs->a[iField].pExpr!=0 );
            pLhs = sqlite3ExprListAppend(pParse,pLhs,pOrigLhs->a[iField].pExpr);
            pOrigLhs->a[iField].pExpr = 0;

  for(i=0; i<iEq; i++){
    if( pLoop->aLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){
      disableTerm(pLevel, pTerm);
      return;
    }
  }
  for(i=iEq; i<pLoop->nLTerm; i++){
    assert( pLoop->aLTerm[i]!=0 );
    if( pLoop->aLTerm[i]->pExpr==pX ) nEq++;
  }

  iTab = 0;
  if( !ExprUseXSelect(pX) || pX->x.pSelect->pEList->nExpr==1 ){
    eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0, &iTab);
  }else{


    sqlite3 *db = pParse->db;
    Expr *pXMod = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);
    if( !db->mallocFailed ){
      aiMap = (int*)sqlite3DbMallocZero(db, sizeof(int)*nEq);
      eType = sqlite3FindInIndex(pParse, pXMod, IN_INDEX_LOOP, 0, aiMap, &iTab);

    }
    sqlite3ExprDelete(db, pXMod);






  }

  if( eType==IN_INDEX_INDEX_DESC ){
    testcase( bRev );
    bRev = !bRev;
  }
  sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);

     sqlite3WhereRealloc(pTerm->pWC->pWInfo,
                         pLevel->u.in.aInLoop,
                         sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
  pIn = pLevel->u.in.aInLoop;
  if( pIn ){
    int iMap = 0;               /* Index in aiMap[] */
    pIn += i;
    for(i=iEq; i<pLoop->nLTerm; i++){
      if( pLoop->aLTerm[i]->pExpr==pX ){
        int iOut = iTarget + i - iEq;
        if( eType==IN_INDEX_ROWID ){
          pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iOut);
        }else{
          int iCol = aiMap ? aiMap[iMap++] : 0;
          pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);

static SQLITE_NOINLINE void filterPullDown(
  Parse *pParse,       /* Parsing context */
  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
  int iLevel,          /* Which level of pWInfo->a[] should be coded */
  int addrNxt,         /* Jump here to bypass inner loops */
  Bitmask notReady     /* Loops that are not ready */
){
  int saved_addrBrk;
  while( ++iLevel < pWInfo->nLevel ){
    WhereLevel *pLevel = &pWInfo->a[iLevel];
    WhereLoop *pLoop = pLevel->pWLoop;
    if( pLevel->regFilter==0 ) continue;
    if( pLevel->pWLoop->nSkip ) continue;
    /*         ,--- Because sqlite3ConstructBloomFilter() has will not have set
    **  vvvvv--'    pLevel->regFilter if this were true. */
    if( NEVER(pLoop->prereq & notReady) ) continue;
    saved_addrBrk = pLevel->addrBrk;
    pLevel->addrBrk = addrNxt;
    if( pLoop->wsFlags & WHERE_IPK ){
      WhereTerm *pTerm = pLoop->aLTerm[0];
      int regRowid;
      assert( pTerm!=0 );
      assert( pTerm->pExpr!=0 );
      testcase( pTerm->wtFlags & TERM_VIRTUAL );

      codeApplyAffinity(pParse, r1, nEq, zStartAff);
      sqlite3DbFree(pParse->db, zStartAff);
      sqlite3VdbeAddOp4Int(pParse->pVdbe, OP_Filter, pLevel->regFilter,
                           addrNxt, r1, nEq);
      VdbeCoverage(pParse->pVdbe);
    }
    pLevel->regFilter = 0;
    pLevel->addrBrk = saved_addrBrk;
  }
}

/*
** Loop pLoop is a WHERE_INDEXED level that uses at least one IN(...)
** operator. Return true if level pLoop is guaranteed to visit only one
** row for each key generated for the index.

  int bRev;            /* True if we need to scan in reverse order */
  WhereLoop *pLoop;    /* The WhereLoop object being coded */
  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
  WhereTerm *pTerm;               /* A WHERE clause term */
  sqlite3 *db;                    /* Database connection */
  SrcItem *pTabItem;              /* FROM clause term being coded */
  int addrBrk;                    /* Jump here to break out of the loop */

  int addrCont;                   /* Jump here to continue with next cycle */
  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
  int iReleaseReg = 0;      /* Temp register to free before returning */
  Index *pIdx = 0;          /* Index used by loop (if any) */
  int iLoop;                /* Iteration of constraint generator loop */

  pWC = &pWInfo->sWC;

  ** loop.
  **
  ** When there is an IN operator, we also have a "addrNxt" label that
  ** means to continue with the next IN value combination.  When
  ** there are no IN operators in the constraints, the "addrNxt" label
  ** is the same as "addrBrk".
  */
  addrBrk = pLevel->addrNxt = pLevel->addrBrk;
  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(pParse);

  /* If this is the right table of a LEFT OUTER JOIN, allocate and
  ** initialize a memory cell that records if this table matches any
  ** row of the left table of the join.
  */
  assert( (pWInfo->wctrlFlags & (WHERE_OR_SUBCLAUSE|WHERE_RIGHT_JOIN))
       || pLevel->iFrom>0 || (pTabItem[0].fg.jointype & JT_LEFT)==0
  );
  if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
    pLevel->iLeftJoin = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
    VdbeComment((v, "init LEFT JOIN match flag"));
  }









  /* Special case of a FROM clause subquery implemented as a co-routine */
  if( pTabItem->fg.viaCoroutine ){
    int regYield;
    Subquery *pSubq;
    assert( pTabItem->fg.isSubquery && pTabItem->u4.pSubq!=0 );
    pSubq = pTabItem->u4.pSubq;
    regYield = pSubq->regReturn;

      VdbeComment((v, "pk"));
      VdbeCoverageIf(v, pX->op==TK_GT);
      VdbeCoverageIf(v, pX->op==TK_LE);
      VdbeCoverageIf(v, pX->op==TK_LT);
      VdbeCoverageIf(v, pX->op==TK_GE);
      sqlite3ReleaseTempReg(pParse, rTemp);
    }else{
      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, pLevel->addrHalt);
      VdbeCoverageIf(v, bRev==0);
      VdbeCoverageIf(v, bRev!=0);
    }
    if( pEnd ){
      Expr *pX;
      pX = pEnd->pExpr;
      assert( pX!=0 );

      /* Tables marked isRecursive have only a single row that is stored in
      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
      pLevel->op = OP_Noop;
    }else{
      codeCursorHint(pTabItem, pWInfo, pLevel, 0);
      pLevel->op = aStep[bRev];
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev],iCur,pLevel->addrHalt);
      VdbeCoverageIf(v, bRev==0);
      VdbeCoverageIf(v, bRev!=0);
      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
    }
  }

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  char aff1, aff2;
  CollSeq *pColl;
  if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;  /* (1) */
  if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;                 /* (2) */
  if( ExprHasProperty(pExpr, EP_OuterON) ) return 0;                   /* (3) */
  assert( pSrc!=0 );
  if( pExpr->op==TK_IS
   && pSrc->nSrc>=2
   && (pSrc->a[0].fg.jointype & JT_LTORJ)!=0
  ){
    return 0;                                                          /* (4) */
  }
  aff1 = sqlite3ExprAffinity(pExpr->pLeft);
  aff2 = sqlite3ExprAffinity(pExpr->pRight);
  if( aff1!=aff2

/*
** Possibly add terms corresponding to the LIMIT and OFFSET clauses of the
** SELECT statement passed as the second argument. These terms are only
** added if:
**
**   1. The SELECT statement has a LIMIT clause, and
**   2. The SELECT statement is not an aggregate or DISTINCT query, and
**   3. The SELECT statement has exactly one object in its FROM clause, and
**      that object is a virtual table, and
**   4. There are no terms in the WHERE clause that will not be passed
**      to the virtual table xBestIndex method.
**   5. The ORDER BY clause, if any, will be made available to the xBestIndex
**      method.
**
** LIMIT and OFFSET terms are ignored by most of the planner code. They

      if( pWC->a[ii].nChild ){
        /* If this term has child terms, then they are also part of the
        ** pWC->a[] array. So this term can be ignored, as a LIMIT clause
        ** will only be added if each of the child terms passes the
        ** (leftCursor==iCsr) test below.  */
        continue;
      }
      if( pWC->a[ii].leftCursor==iCsr && pWC->a[ii].prereqRight==0 ) continue;

      /* If this term has a parent with exactly one child, and the parent will
      ** be passed through to xBestIndex, then this term can be ignored.  */
      if( pWC->a[ii].iParent>=0 ){
        WhereTerm *pParent = &pWC->a[ pWC->a[ii].iParent ];
        if( pParent->leftCursor==iCsr
         && pParent->prereqRight==0
         && pParent->nChild==1
        ){
          continue;
        }
      }

      /* This term will not be passed through. Do not add a LIMIT clause. */
      return;
    }

    /* Check condition (5). Return early if it is not met. */
    if( pOrderBy ){
      for(ii=0; ii<pOrderBy->nExpr; ii++){
        Expr *pExpr = pOrderBy->a[ii].pExpr;
        if( pExpr->op!=TK_COLUMN ) return;

    regYield = pSubq->regReturn;
    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pSubq->addrFillSub);
    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
    VdbeCoverage(v);
    VdbeComment((v, "next row of %s", pSrc->pSTab->zName));
  }else{
    assert( pLevel->addrHalt );
    addrTop = sqlite3VdbeAddOp2(v, OP_Rewind,pLevel->iTabCur,pLevel->addrHalt);
    VdbeCoverage(v);
  }
  if( pPartial ){
    iContinue = sqlite3VdbeMakeLabel(pParse);
    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
    pLoop->wsFlags |= WHERE_PARTIALIDX;
  }
  regRecord = sqlite3GetTempReg(pParse);

    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
    testcase( pParse->db->mallocFailed );
    assert( pLevel->iIdxCur>0 );
    translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,
                          pSrc->u4.pSubq->regResult, pLevel->iIdxCur);
    sqlite3VdbeGoto(v, addrTop);
    pSrc->fg.viaCoroutine = 0;
    sqlite3VdbeJumpHere(v, addrTop);
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
    sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);

    if( (pSrc->fg.jointype & JT_LEFT)!=0 ){
      sqlite3VdbeJumpHere(v, addrTop);
    }
  }
  sqlite3ReleaseTempReg(pParse, regRecord);

  /* Jump here when skipping the initialization */
  sqlite3VdbeJumpHere(v, addrInit);
  sqlite3VdbeScanStatusRange(v, addrExp, addrExp, -1);

end_auto_index_create:

    );

    if( eOp & WO_IN ){
      Expr *pExpr = pTerm->pExpr;
      if( ExprUseXSelect(pExpr) ){
        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
        int i;
        int bRedundant = 0;
        nIn = 46;  assert( 46==sqlite3LogEst(25) );

        /* The expression may actually be of the form (x, y) IN (SELECT...).
        ** In this case there is a separate term for each of (x) and (y).
        ** However, the nIn multiplier should only be applied once, not once
        ** for each such term. The following loop checks that pTerm is the
        ** first such term in use, and sets nIn back to 0 if it is not. */
        for(i=0; i<pNew->nLTerm-1; i++){
          if( pNew->aLTerm[i] && pNew->aLTerm[i]->pExpr==pExpr ){
            nIn = 0;
            if( pNew->aLTerm[i]->u.x.iField == pTerm->u.x.iField ){
              /* Detect when two or more columns of an index match the same
              ** column of a vector IN operater, and avoid adding the column
              ** to the WhereLoop more than once.  See tag-20250707-01
              ** in test/rowvalue.test */
              bRedundant = 1;
            }
          }
        }
        if( bRedundant ){
          pNew->nLTerm--;
          continue;
        }
      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
        /* "x IN (value, value, ...)" */
        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
      }
      if( pProbe->hasStat1 && rLogSize>=10 ){
        LogEst M, logK, x;

    }else{
      pNew->nOut = nOutUnadjusted;
    }

    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
     && pNew->u.btree.nEq<pProbe->nColumn
     && (pNew->u.btree.nEq<pProbe->nKeyCol ||
          pProbe->idxType!=SQLITE_IDXTYPE_PRIMARYKEY)
    ){
      if( pNew->u.btree.nEq>3 ){
        sqlite3ProgressCheck(pParse);
      }
      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
    }
    pNew->nOut = saved_nOut;

  if( saved_nEq==saved_nSkip
   && saved_nEq+1<pProbe->nKeyCol
   && saved_nEq==pNew->nLTerm
   && pProbe->noSkipScan==0
   && pProbe->hasStat1!=0
   && OptimizationEnabled(db, SQLITE_SkipScan)
   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
   && pSrc->fg.fromExists==0
   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
  ){
    LogEst nIter;
    pNew->u.btree.nEq++;
    pNew->nSkip++;
    pNew->aLTerm[pNew->nLTerm++] = 0;
    pNew->wsFlags |= WHERE_SKIPSCAN;

    int iDb;         /* Index of database containing table/index */
    SrcItem *pTabItem;

    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pSTab;
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    pLoop = pLevel->pWLoop;
    pLevel->addrBrk = sqlite3VdbeMakeLabel(pParse);
    if( ii==0 || (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
      pLevel->addrHalt = pLevel->addrBrk;
    }else if( pWInfo->a[ii-1].pRJ ){
      pLevel->addrHalt = pWInfo->a[ii-1].addrBrk;
    }else{
      pLevel->addrHalt = pWInfo->a[ii-1].addrHalt;
    }
    if( (pTab->tabFlags & TF_Ephemeral)!=0 || IsView(pTab) ){
      /* Do nothing */
    }else
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      int iCur = pTabItem->iCursor;

      {
        sqlite3VdbeChangeP5(v, bFordelete);
      }
#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
      sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,
                            (const u8*)&pTabItem->colUsed, P4_INT64);
#endif
      if( ii>=2
       && (pTabItem[0].fg.jointype & (JT_LTORJ|JT_LEFT))==0
       && pLevel->addrHalt==pWInfo->a[0].addrHalt
      ){
        sqlite3VdbeAddOp2(v, OP_IfEmpty, pTabItem->iCursor, pWInfo->iBreak);
        VdbeCoverage(v);
      }
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    if( pLoop->wsFlags & WHERE_INDEXED ){
      Index *pIx = pLoop->u.btree.pIndex;
      int iIndexCur;
      int op = OP_OpenRead;

        op = pLevel->op==OP_Prev ? OP_SeekLT : OP_SeekGT;
        addrSeek = sqlite3VdbeAddOp4Int(v, op, pLevel->iIdxCur, 0, r1, n);
        VdbeCoverageIf(v, op==OP_SeekLT);
        VdbeCoverageIf(v, op==OP_SeekGT);
        sqlite3VdbeAddOp2(v, OP_Goto, 1, pLevel->p2);
      }
#endif /* SQLITE_DISABLE_SKIPAHEAD_DISTINCT */
      if( pTabList->a[pLevel->iFrom].fg.fromExists ){
        sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+2);
      }
      /* The common case: Advance to the next row */
      if( pLevel->addrCont ) sqlite3VdbeResolveLabel(v, pLevel->addrCont);
      sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);
      sqlite3VdbeChangeP5(v, pLevel->p5);
      VdbeCoverage(v);
      VdbeCoverageIf(v, pLevel->op==OP_Next);
      VdbeCoverageIf(v, pLevel->op==OP_Prev);

{
    if( yymsp[-1].minor.yy402==0 ){
      /* Expressions of the form
      **
      **      expr1 IN ()
      **      expr1 NOT IN ()
      **
      ** simplify to constants 0 (false) and 1 (true), respectively.
      **
      ** Except, do not apply this optimization if expr1 contains a function
      ** because that function might be an aggregate (we don't know yet whether
      ** it is or not) and if it is an aggregate, that could change the meaning
      ** of the whole query.
      */
      Expr *pB = sqlite3Expr(pParse->db, TK_STRING, yymsp[-3].minor.yy502 ? "true" : "false");
      if( pB ) sqlite3ExprIdToTrueFalse(pB);
      if( !ExprHasProperty(yymsp[-4].minor.yy590, EP_HasFunc) ){
        sqlite3ExprUnmapAndDelete(pParse, yymsp[-4].minor.yy590);
        yymsp[-4].minor.yy590 = pB;
      }else{
        yymsp[-4].minor.yy590 = sqlite3PExpr(pParse, yymsp[-3].minor.yy502 ? TK_OR : TK_AND, pB, yymsp[-4].minor.yy590);
      }
    }else{
      Expr *pRHS = yymsp[-1].minor.yy402->a[0].pExpr;
      if( yymsp[-1].minor.yy402->nExpr==1 && sqlite3ExprIsConstant(pParse,pRHS) && yymsp[-4].minor.yy590->op!=TK_VECTOR ){
        yymsp[-1].minor.yy402->a[0].pExpr = 0;
        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy402);
        pRHS = sqlite3PExpr(pParse, TK_UPLUS, pRHS, 0);
        yymsp[-4].minor.yy590 = sqlite3PExpr(pParse, TK_EQ, yymsp[-4].minor.yy590, pRHS);

** (*pz) to point to the byte following the parsed token.
*/
static int getToken(const unsigned char **pz){
  const unsigned char *z = *pz;
  int t;                          /* Token type to return */
  do {
    z += sqlite3GetToken(z, &t);
  }while( t==TK_SPACE || t==TK_COMMENT );
  if( t==TK_ID
   || t==TK_STRING
   || t==TK_JOIN_KW
   || t==TK_WINDOW
   || t==TK_OVER
   || sqlite3ParserFallback(t)==TK_ID
  ){

  ** first rowid on this page.
  */
  if( pLast ){
    int iOff;
    fts5DataRelease(pIter->pLeaf);
    pIter->pLeaf = pLast;
    pIter->iLeafPgno = pgnoLast;
    if( p->rc==SQLITE_OK ){
      iOff = fts5LeafFirstRowidOff(pLast);
      if( iOff>pLast->szLeaf ){
        FTS5_CORRUPT_ITER(p, pIter);
        return;
      }
      iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);
      pIter->iLeafOffset = iOff;

      if( fts5LeafIsTermless(pLast) ){
        pIter->iEndofDoclist = pLast->nn+1;
      }else{
        pIter->iEndofDoclist = fts5LeafFirstTermOff(pLast);
      }
    }
  }

  fts5SegIterReverseInitPage(p, pIter);
}

/*

      fts5StructureRef(pStruct);
      return pStruct;
    }
    assert( pStruct->aLevel[i].nMerge<=nThis );
  }

  nByte += (((i64)pStruct->nLevel)+1) * sizeof(Fts5StructureLevel);
  assert( nByte==(i64)SZ_FTS5STRUCTURE(pStruct->nLevel+2) );
  pNew = (Fts5Structure*)sqlite3Fts5MallocZero(&p->rc, nByte);

  if( pNew ){
    Fts5StructureLevel *pLvl;
    nByte = nSeg * sizeof(Fts5StructureSegment);
    pNew->nLevel = MIN(pStruct->nLevel+1, FTS5_MAX_LEVEL);
    pNew->nRef = 1;

  return 0;
}

/*
** This function is also purely an internal test. It does not contribute to
** FTS functionality, or even the integrity-check, in any way.
**
** This function sets output variable (*pbFail) to true if the test fails. Or
** leaves it unchanged if the test succeeds.
*/
static void fts5TestTerm(
  Fts5Index *p,
  Fts5Buffer *pPrev,              /* Previous term */
  const char *z, int n,           /* Possibly new term to test */
  u64 expected,
  u64 *pCksum,
  int *pbFail
){
  int rc = p->rc;
  if( pPrev->n==0 ){
    fts5BufferSet(&rc, pPrev, n, (const u8*)z);
  }else
  if( *pbFail==0
   && rc==SQLITE_OK
   && (pPrev->n!=n || memcmp(pPrev->p, z, n))
   && (p->pHash==0 || p->pHash->nEntry==0)
  ){
    u64 cksum3 = *pCksum;
    const char *zTerm = (const char*)&pPrev->p[1];  /* term sans prefix-byte */
    int nTerm = pPrev->n-1;            /* Size of zTerm in bytes */
    int iIdx = (pPrev->p[0] - FTS5_MAIN_PREFIX);
    int flags = (iIdx==0 ? 0 : FTS5INDEX_QUERY_PREFIX);
    u64 ck1 = 0;
    u64 ck2 = 0;

      }
    }

    cksum3 ^= ck1;
    fts5BufferSet(&rc, pPrev, n, (const u8*)z);

    if( rc==SQLITE_OK && cksum3!=expected ){
      *pbFail = 1;
    }
    *pCksum = cksum3;
  }
  p->rc = rc;
}

#else
# define fts5TestDlidxReverse(x,y,z)
# define fts5TestTerm(t,u,v,w,x,y,z)
#endif

/*
** Check that:
**
**   1) All leaves of pSeg between iFirst and iLast (inclusive) exist and
**      contain zero terms.

  Fts5Structure *pStruct;         /* Index structure */
  int iLvl, iSeg;

#ifdef SQLITE_DEBUG
  /* Used by extra internal tests only run if NDEBUG is not defined */
  u64 cksum3 = 0;                 /* Checksum based on contents of indexes */
  Fts5Buffer term = {0,0,0};      /* Buffer used to hold most recent term */
  int bTestFail = 0;
#endif
  const int flags = FTS5INDEX_QUERY_NOOUTPUT;

  /* Load the FTS index structure */
  pStruct = fts5StructureRead(p);
  if( pStruct==0 ){
    assert( p->rc!=SQLITE_OK );

    int n;                      /* Size of term in bytes */
    i64 iPos = 0;               /* Position read from poslist */
    int iOff = 0;               /* Offset within poslist */
    i64 iRowid = fts5MultiIterRowid(pIter);
    char *z = (char*)fts5MultiIterTerm(pIter, &n);

    /* If this is a new term, query for it. Update cksum3 with the results. */
    fts5TestTerm(p, &term, z, n, cksum2, &cksum3, &bTestFail);
    if( p->rc ) break;

    if( eDetail==FTS5_DETAIL_NONE ){
      if( 0==fts5MultiIterIsEmpty(p, pIter) ){
        cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, 0, 0, -1, z, n);
      }
    }else{
      poslist.n = 0;
      fts5SegiterPoslist(p, &pIter->aSeg[pIter->aFirst[1].iFirst], 0, &poslist);
      fts5BufferAppendBlob(&p->rc, &poslist, 4, (const u8*)"\0\0\0\0");
      while( 0==sqlite3Fts5PoslistNext64(poslist.p, poslist.n, &iOff, &iPos) ){
        int iCol = FTS5_POS2COLUMN(iPos);
        int iTokOff = FTS5_POS2OFFSET(iPos);
        cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, iCol, iTokOff, -1, z, n);
      }
    }
  }
  fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3, &bTestFail);

  fts5MultiIterFree(pIter);
  if( p->rc==SQLITE_OK && bUseCksum && cksum!=cksum2 ){
    p->rc = FTS5_CORRUPT;
    sqlite3Fts5ConfigErrmsg(p->pConfig,
        "fts5: checksum mismatch for table \"%s\"", p->pConfig->zName
    );
  }


#ifdef SQLITE_DEBUG
  /* In SQLITE_DEBUG builds, expensive extra checks were run as part of
  ** the integrity-check above. If no other errors were detected, but one
  ** of these tests failed, set the result to SQLITE_CORRUPT_VTAB here. */
  if( p->rc==SQLITE_OK && bTestFail ){
    p->rc = FTS5_CORRUPT;
  }
  fts5BufferFree(&term);
#endif

  fts5StructureRelease(pStruct);
  fts5BufferFree(&poslist);
  return fts5IndexReturn(p);
}

/*************************************************************************
**************************************************************************
** Below this point is the implementation of the fts5_decode() scalar

static void fts5SourceIdFunc(
  sqlite3_context *pCtx,          /* Function call context */
  int nArg,                       /* Number of args */
  sqlite3_value **apUnused        /* Function arguments */
){
  assert( nArg==0 );
  UNUSED_PARAM2(nArg, apUnused);
  sqlite3_result_text(pCtx, "fts5: 2025-07-08 19:02:26 043ff54fb746c54bc6cfa6aa8c8a32c876c09d36163125916ad01024b98d447b", -1, SQLITE_TRANSIENT);
}

/*
** Implementation of fts5_locale(LOCALE, TEXT) function.
**
** If parameter LOCALE is NULL, or a zero-length string, then a copy of
** TEXT is returned. Otherwise, both LOCALE and TEXT are interpreted as