Fossil

      zLine[n] = 0;
      break;
    }
  }
#if defined(_WIN32) || defined(WIN32)
  /* For interactive input on Windows systems, translate the
  ** multi-byte characterset characters into UTF-8. */
  if( stdin_is_interactive && in==stdin ){
    char *zTrans = sqlite3_win32_mbcs_to_utf8_v2(zLine, 0);
    if( zTrans ){
      int nTrans = strlen30(zTrans)+1;
      if( nTrans>nLine ){
        zLine = realloc(zLine, nTrans);
        if( zLine==0 ){
          sqlite3_free(zTrans);

  int startline = 0;        /* Line number for start of current input */

  while( errCnt==0 || !bail_on_error || (in==0 && stdin_is_interactive) ){
    fflush(p->out);
    zLine = one_input_line(in, zLine, nSql>0);
    if( zLine==0 ){
      /* End of input */
      if( in==0 && stdin_is_interactive ) printf("\n");
      break;
    }
    if( seenInterrupt ){
      if( in!=0 ) break;
      seenInterrupt = 0;
    }
    lineno++;

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.15.0"
#define SQLITE_VERSION_NUMBER 3015000
#define SQLITE_SOURCE_ID      "2016-09-07 19:54:24 ddb5f0558c44569913d22781ab78f3e9b58d7aea"

/*
** 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

  void *pB,                       /* Pointer to buffer containing changeset B */
  int *pnOut,                     /* OUT: Number of bytes in output changeset */
  void **ppOut                    /* OUT: Buffer containing output changeset */
);


/*
** CAPI3REF: Changegroup Handle
*/
typedef struct sqlite3_changegroup sqlite3_changegroup;

/*
** CAPI3REF: Create A New Changegroup Object
**
** An sqlite3_changegroup object is used to combine two or more changesets
** (or patchsets) into a single changeset (or patchset). A single changegroup
** object may combine changesets or patchsets, but not both. The output is
** always in the same format as the input.
**
** If successful, this function returns SQLITE_OK and populates (*pp) with

** As well as the regular sqlite3changegroup_add() and 
** sqlite3changegroup_output() functions, also available are the streaming
** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
*/
int sqlite3changegroup_new(sqlite3_changegroup **pp);

/*
** CAPI3REF: Add A Changeset To A Changegroup
**
** Add all changes within the changeset (or patchset) in buffer pData (size
** nData bytes) to the changegroup. 
**
** If the buffer contains a patchset, then all prior calls to this function
** on the same changegroup object must also have specified patchsets. Or, if
** the buffer contains a changeset, so must have the earlier calls to this
** function. Otherwise, SQLITE_ERROR is returned and no changes are added

** final contents of the changegroup is undefined.
**
** If no error occurs, SQLITE_OK is returned.
*/
int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);

/*
** CAPI3REF: Obtain A Composite Changeset From A Changegroup
**
** Obtain a buffer containing a changeset (or patchset) representing the
** current contents of the changegroup. If the inputs to the changegroup
** were themselves changesets, the output is a changeset. Or, if the
** inputs were patchsets, the output is also a patchset.
**
** As with the output of the sqlite3session_changeset() and
** sqlite3session_patchset() functions, all changes related to a single

int sqlite3changegroup_output(
  sqlite3_changegroup*,
  int *pnData,                    /* OUT: Size of output buffer in bytes */
  void **ppData                   /* OUT: Pointer to output buffer */
);

/*
** CAPI3REF: Delete A Changegroup Object
*/
void sqlite3changegroup_delete(sqlite3_changegroup*);

/*
** CAPI3REF: Apply A Changeset To A Database
**
** Apply a changeset to a database. This function attempts to update the

#define TK_FUNCTION                       151
#define TK_COLUMN                         152
#define TK_AGG_FUNCTION                   153
#define TK_AGG_COLUMN                     154
#define TK_UMINUS                         155
#define TK_UPLUS                          156
#define TK_REGISTER                       157
#define TK_VECTOR                         158
#define TK_SELECT_COLUMN                  159
#define TK_ASTERISK                       160
#define TK_SPAN                           161
#define TK_SPACE                          162
#define TK_ILLEGAL                        163

/* The token codes above must all fit in 8 bits */
#define TKFLG_MASK           0xff  

/* Flags that can be added to a token code when it is not
** being stored in a u8: */
#define TKFLG_DONTFOLD       0x100  /* Omit constant folding optimizations */

#define OP_NoConflict     29 /* synopsis: key=r[P3@P4]                     */
#define OP_NotFound       30 /* synopsis: key=r[P3@P4]                     */
#define OP_Found          31 /* synopsis: key=r[P3@P4]                     */
#define OP_SeekRowid      32 /* synopsis: intkey=r[P3]                     */
#define OP_NotExists      33 /* synopsis: intkey=r[P3]                     */
#define OP_IsNull         34 /* same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */
#define OP_NotNull        35 /* same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */
#define OP_Ne             36 /* same as TK_NE, synopsis: IF r[P3]!=r[P1]   */
#define OP_Eq             37 /* same as TK_EQ, synopsis: IF r[P3]==r[P1]   */
#define OP_Gt             38 /* same as TK_GT, synopsis: IF r[P3]>r[P1]    */
#define OP_Le             39 /* same as TK_LE, synopsis: IF r[P3]<=r[P1]   */
#define OP_Lt             40 /* same as TK_LT, synopsis: IF r[P3]<r[P1]    */
#define OP_Ge             41 /* same as TK_GE, synopsis: IF r[P3]>=r[P1]   */
#define OP_ElseNotEq      42 /* same as TK_ESCAPE                          */
#define OP_BitAnd         43 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */
#define OP_BitOr          44 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */
#define OP_ShiftLeft      45 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<<r[P1] */
#define OP_ShiftRight     46 /* same as TK_RSHIFT, synopsis: r[P3]=r[P2]>>r[P1] */
#define OP_Add            47 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */
#define OP_Subtract       48 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */
#define OP_Multiply       49 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */
#define OP_Divide         50 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */
#define OP_Remainder      51 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */
#define OP_Concat         52 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */
#define OP_Last           53
#define OP_BitNot         54 /* same as TK_BITNOT, synopsis: r[P1]= ~r[P1] */
#define OP_SorterSort     55
#define OP_Sort           56
#define OP_Rewind         57
#define OP_IdxLE          58 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxGT          59 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxLT          60 /* synopsis: key=r[P3@P4]                     */
#define OP_IdxGE          61 /* synopsis: key=r[P3@P4]                     */
#define OP_RowSetRead     62 /* synopsis: r[P3]=rowset(P1)                 */
#define OP_RowSetTest     63 /* synopsis: if r[P3] in rowset(P1) goto P2   */
#define OP_Program        64
#define OP_FkIfZero       65 /* synopsis: if fkctr[P1]==0 goto P2          */
#define OP_IfPos          66 /* synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
#define OP_IfNotZero      67 /* synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2 */
#define OP_DecrJumpZero   68 /* synopsis: if (--r[P1])==0 goto P2          */
#define OP_IncrVacuum     69
#define OP_VNext          70
#define OP_Init           71 /* synopsis: Start at P2                      */
#define OP_Return         72
#define OP_EndCoroutine   73
#define OP_HaltIfNull     74 /* synopsis: if r[P3]=null halt               */
#define OP_Halt           75
#define OP_Integer        76 /* synopsis: r[P2]=P1                         */
#define OP_Int64          77 /* synopsis: r[P2]=P4                         */
#define OP_String         78 /* synopsis: r[P2]='P4' (len=P1)              */
#define OP_Null           79 /* synopsis: r[P2..P3]=NULL                   */
#define OP_SoftNull       80 /* synopsis: r[P1]=NULL                       */
#define OP_Blob           81 /* synopsis: r[P2]=P4 (len=P1)                */
#define OP_Variable       82 /* synopsis: r[P2]=parameter(P1,P4)           */
#define OP_Move           83 /* synopsis: r[P2@P3]=r[P1@P3]                */
#define OP_Copy           84 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */
#define OP_SCopy          85 /* synopsis: r[P2]=r[P1]                      */
#define OP_IntCopy        86 /* synopsis: r[P2]=r[P1]                      */
#define OP_ResultRow      87 /* synopsis: output=r[P1@P2]                  */
#define OP_CollSeq        88
#define OP_Function0      89 /* synopsis: r[P3]=func(r[P2@P5])             */
#define OP_Function       90 /* synopsis: r[P3]=func(r[P2@P5])             */
#define OP_AddImm         91 /* synopsis: r[P1]=r[P1]+P2                   */
#define OP_RealAffinity   92
#define OP_Cast           93 /* synopsis: affinity(r[P1])                  */
#define OP_Permutation    94
#define OP_Compare        95 /* synopsis: r[P1@P3] <-> r[P2@P3]            */
#define OP_Column         96 /* synopsis: r[P3]=PX                         */

#define OP_String8        97 /* same as TK_STRING, synopsis: r[P2]='P4'    */
#define OP_Affinity       98 /* synopsis: affinity(r[P1@P2])               */
#define OP_MakeRecord     99 /* synopsis: r[P3]=mkrec(r[P1@P2])            */
#define OP_Count         100 /* synopsis: r[P2]=count()                    */
#define OP_ReadCookie    101
#define OP_SetCookie     102
#define OP_ReopenIdx     103 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenRead      104 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenWrite     105 /* synopsis: root=P2 iDb=P3                   */
#define OP_OpenAutoindex 106 /* synopsis: nColumn=P2                       */
#define OP_OpenEphemeral 107 /* synopsis: nColumn=P2                       */
#define OP_SorterOpen    108
#define OP_SequenceTest  109 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */
#define OP_OpenPseudo    110 /* synopsis: P3 columns in r[P2]              */
#define OP_Close         111
#define OP_ColumnsUsed   112
#define OP_Sequence      113 /* synopsis: r[P2]=cursor[P1].ctr++           */
#define OP_NewRowid      114 /* synopsis: r[P2]=rowid                      */
#define OP_Insert        115 /* synopsis: intkey=r[P3] data=r[P2]          */
#define OP_InsertInt     116 /* synopsis: intkey=P3 data=r[P2]             */
#define OP_Delete        117
#define OP_ResetCount    118
#define OP_SorterCompare 119 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */
#define OP_SorterData    120 /* synopsis: r[P2]=data                       */
#define OP_RowKey        121 /* synopsis: r[P2]=key                        */
#define OP_RowData       122 /* synopsis: r[P2]=data                       */
#define OP_Rowid         123 /* synopsis: r[P2]=rowid                      */
#define OP_NullRow       124
#define OP_SorterInsert  125
#define OP_IdxInsert     126 /* synopsis: key=r[P2]                        */
#define OP_IdxDelete     127 /* synopsis: key=r[P2@P3]                     */
#define OP_Seek          128 /* synopsis: Move P3 to P1.rowid              */
#define OP_IdxRowid      129 /* synopsis: r[P2]=rowid                      */
#define OP_Destroy       130
#define OP_Clear         131
#define OP_ResetSorter   132

#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
#define OP_CreateIndex   134 /* synopsis: r[P2]=root iDb=P1                */
#define OP_CreateTable   135 /* synopsis: r[P2]=root iDb=P1                */
#define OP_ParseSchema   136
#define OP_LoadAnalysis  137
#define OP_DropTable     138
#define OP_DropIndex     139
#define OP_DropTrigger   140
#define OP_IntegrityCk   141
#define OP_RowSetAdd     142 /* synopsis: rowset(P1)=r[P2]                 */
#define OP_Param         143
#define OP_FkCounter     144 /* synopsis: fkctr[P1]+=P2                    */
#define OP_MemMax        145 /* synopsis: r[P1]=max(r[P1],r[P2])           */
#define OP_OffsetLimit   146 /* synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1) */
#define OP_AggStep0      147 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggStep       148 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggFinal      149 /* synopsis: accum=r[P1] N=P2                 */
#define OP_Expire        150
#define OP_TableLock     151 /* synopsis: iDb=P1 root=P2 write=P3          */
#define OP_VBegin        152
#define OP_VCreate       153
#define OP_VDestroy      154
#define OP_VOpen         155
#define OP_VColumn       156 /* synopsis: r[P3]=vcolumn(P2)                */
#define OP_VRename       157
#define OP_Pagecount     158
#define OP_MaxPgcnt      159
#define OP_CursorHint    160
#define OP_Noop          161
#define OP_Explain       162

/* 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_INITIALIZER {\
/*   0 */ 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01,\
/*   8 */ 0x00, 0x10, 0x00, 0x01, 0x00, 0x01, 0x01, 0x01,\
/*  16 */ 0x03, 0x03, 0x01, 0x12, 0x01, 0x03, 0x03, 0x09,\
/*  24 */ 0x09, 0x09, 0x09, 0x26, 0x26, 0x09, 0x09, 0x09,\
/*  32 */ 0x09, 0x09, 0x03, 0x03, 0x0b, 0x0b, 0x0b, 0x0b,\
/*  40 */ 0x0b, 0x0b, 0x01, 0x26, 0x26, 0x26, 0x26, 0x26,\
/*  48 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x01, 0x12, 0x01,\
/*  56 */ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x23, 0x0b,\
/*  64 */ 0x01, 0x01, 0x03, 0x03, 0x03, 0x01, 0x01, 0x01,\
/*  72 */ 0x02, 0x02, 0x08, 0x00, 0x10, 0x10, 0x10, 0x10,\
/*  80 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x10, 0x10, 0x00,\
/*  88 */ 0x00, 0x00, 0x00, 0x02, 0x02, 0x02, 0x00, 0x00,\
/*  96 */ 0x00, 0x10, 0x00, 0x00, 0x10, 0x10, 0x00, 0x00,\
/* 104 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 112 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 120 */ 0x00, 0x00, 0x00, 0x10, 0x00, 0x04, 0x04, 0x00,\
/* 128 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x10, 0x10, 0x10,\
/* 136 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x10,\
/* 144 */ 0x00, 0x04, 0x1a, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 152 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x10,\
/* 160 */ 0x00, 0x00, 0x00,}

/* The sqlite3P2Values() routine is able to run faster if it knows
** the value of the largest JUMP opcode.  The smaller the maximum
** JUMP opcode the better, so the mkopcodeh.tcl script that
** generated this include file strives to group all JUMP opcodes
** together near the beginning of the list.
*/
#define SQLITE_MX_JUMP_OPCODE  71  /* Maximum JUMP opcode */

/************** 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.

** changing the affinity.
**
** The SQLITE_NOTNULL flag is a combination of NULLEQ and JUMPIFNULL.
** It causes an assert() to fire if either operand to a comparison
** operator is NULL.  It is added to certain comparison operators to
** prove that the operands are always NOT NULL.
*/
#define SQLITE_KEEPNULL     0x08  /* Used by vector == or <> */
#define SQLITE_JUMPIFNULL   0x10  /* jumps if either operand is NULL */
#define SQLITE_STOREP2      0x20  /* Store result in reg[P2] rather than jump */
#define SQLITE_NULLEQ       0x80  /* NULL=NULL */
#define SQLITE_NOTNULL      0x90  /* Assert that operands are never NULL */

/*
** An object of this type is created for each virtual table present in

#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
  int iTable;            /* TK_COLUMN: cursor number of table holding column
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old
                         ** EP_Unlikely:  134217728 times likelihood
                         ** TK_SELECT: 1st register of result vector */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1).
                         ** TK_SELECT_COLUMN: column of the result vector */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 op2;                /* TK_REGISTER: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  Table *pTab;           /* Table for TK_COLUMN expressions. */

/*
** An instance of this object describes where to put of the results of
** a SELECT statement.
*/
struct SelectDest {
  u8 eDest;            /* How to dispose of the results.  On of SRT_* above. */
  char *zAffSdst;      /* Affinity used when eDest==SRT_Set */
  int iSDParm;         /* A parameter used by the eDest disposal method */
  int iSdst;           /* Base register where results are written */
  int nSdst;           /* Number of registers allocated */
  ExprList *pOrderBy;  /* Key columns for SRT_Queue and SRT_DistQueue */
};

/*

#endif
#if defined(SQLITE_TEST)
SQLITE_PRIVATE   void *sqlite3TestTextToPtr(const char*);
#endif

#if defined(SQLITE_DEBUG)
SQLITE_PRIVATE   void sqlite3TreeViewExpr(TreeView*, const Expr*, u8);
SQLITE_PRIVATE   void sqlite3TreeViewBareExprList(TreeView*, const ExprList*, const char*);
SQLITE_PRIVATE   void sqlite3TreeViewExprList(TreeView*, const ExprList*, u8, const char*);
SQLITE_PRIVATE   void sqlite3TreeViewSelect(TreeView*, const Select*, u8);
SQLITE_PRIVATE   void sqlite3TreeViewWith(TreeView*, const With*, u8);
#endif


SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);

SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse*, Expr*, Select*);
SQLITE_PRIVATE Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3*, Expr*);
SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);
SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList*,int);
SQLITE_PRIVATE void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
SQLITE_PRIVATE void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);
SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);
SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);

#define putVarint    sqlite3PutVarint


SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3*, Index*);
SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe*, Table*, int);
SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2);
SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table*,int);
SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr);
SQLITE_PRIVATE int sqlite3Atoi64(const char*, i64*, int, u8);
SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char*, i64*);
SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3*, int, const char*,...);
SQLITE_PRIVATE void sqlite3Error(sqlite3*,int);
SQLITE_PRIVATE void sqlite3SystemError(sqlite3*,int);
SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3*, const char *z, int n);

SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3*, int, int, int);
SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);
SQLITE_PRIVATE void sqlite3AlterFunctions(void);
SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);
SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*);
SQLITE_PRIVATE int sqlite3CodeSubselect(Parse*, Expr *, int, int);
SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);
SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
SQLITE_PRIVATE int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);
SQLITE_PRIVATE int sqlite3ResolveExprListNames(NameContext*, ExprList*);
SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
SQLITE_PRIVATE void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);

SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);
SQLITE_PRIVATE void sqlite3StrAccumReset(StrAccum*);
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);
SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);
SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse*, Expr*);
#else
# define sqlite3ExprCheckIN(x,y) SQLITE_OK
#endif

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void);
SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
    Parse*,Index*,UnpackedRecord**,Expr*,int,int,int*);
SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);
SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);
SQLITE_PRIVATE int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3*, Index*, int);
#endif

/*
** The interface to the LEMON-generated parser
*/
SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(u64));
SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));

#define IN_INDEX_NOOP         5   /* No table available. Use comparisons */
/*
** Allowed flags for the 3rd parameter to sqlite3FindInIndex().
*/
#define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
#define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
#define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*);

SQLITE_PRIVATE int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *);
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
#endif

SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread*, void**);
#endif

#if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3*);
#endif

SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr);
SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr);
SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr*, int);
SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(Parse*,Expr*,int);

#endif /* SQLITEINT_H */

/************** End of sqliteInt.h *******************************************/
/************** Begin file global.c ******************************************/
/*
** 2008 June 13
**

    }
    sqlite3TreeViewPop(pView);
  }
}


/*
** Generate a human-readable description of a Select object.
*/
SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){
  int n = 0;
  int cnt = 0;
  pView = sqlite3TreeViewPush(pView, moreToFollow);
  if( p->pWith ){
    sqlite3TreeViewWith(pView, p->pWith, 1);

    }
#endif
    case TK_MATCH: {
      sqlite3TreeViewLine(pView, "MATCH {%d:%d}%s",
                          pExpr->iTable, pExpr->iColumn, zFlgs);
      sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
      break;
    }
    case TK_VECTOR: {
      sqlite3TreeViewBareExprList(pView, pExpr->x.pList, "VECTOR");
      break;
    }
    case TK_SELECT_COLUMN: {
      sqlite3TreeViewLine(pView, "SELECT-COLUMN %d", pExpr->iColumn);
      sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
      break;
    }
    default: {
      sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
      break;
    }
  }
  if( zBinOp ){
    sqlite3TreeViewLine(pView, "%s%s", zBinOp, zFlgs);
    sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);
    sqlite3TreeViewExpr(pView, pExpr->pRight, 0);
  }else if( zUniOp ){
    sqlite3TreeViewLine(pView, "%s%s", zUniOp, zFlgs);
    sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
  }
  sqlite3TreeViewPop(pView);
}


/*
** Generate a human-readable explanation of an expression list.
*/
SQLITE_PRIVATE void sqlite3TreeViewBareExprList(
  TreeView *pView,
  const ExprList *pList,

  const char *zLabel
){


  if( zLabel==0 || zLabel[0]==0 ) zLabel = "LIST";
  if( pList==0 ){
    sqlite3TreeViewLine(pView, "%s (empty)", zLabel);
  }else{
    int i;
    sqlite3TreeViewLine(pView, "%s", zLabel);
    for(i=0; i<pList->nExpr; i++){
      int j = pList->a[i].u.x.iOrderByCol;
      if( j ){
        sqlite3TreeViewPush(pView, 0);
        sqlite3TreeViewLine(pView, "iOrderByCol=%d", j);
      }
      sqlite3TreeViewExpr(pView, pList->a[i].pExpr, i<pList->nExpr-1);
      if( j ) sqlite3TreeViewPop(pView);
    }
  }
}
SQLITE_PRIVATE void sqlite3TreeViewExprList(
  TreeView *pView,
  const ExprList *pList,
  u8 moreToFollow,
  const char *zLabel
){
  pView = sqlite3TreeViewPush(pView, moreToFollow);
  sqlite3TreeViewBareExprList(pView, pList, zLabel);
  sqlite3TreeViewPop(pView);
}

#endif /* SQLITE_DEBUG */

/************** End of treeview.c ********************************************/
/************** Begin file random.c ******************************************/

    /*  29 */ "NoConflict"       OpHelp("key=r[P3@P4]"),
    /*  30 */ "NotFound"         OpHelp("key=r[P3@P4]"),
    /*  31 */ "Found"            OpHelp("key=r[P3@P4]"),
    /*  32 */ "SeekRowid"        OpHelp("intkey=r[P3]"),
    /*  33 */ "NotExists"        OpHelp("intkey=r[P3]"),
    /*  34 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),
    /*  35 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),
    /*  36 */ "Ne"               OpHelp("IF r[P3]!=r[P1]"),
    /*  37 */ "Eq"               OpHelp("IF r[P3]==r[P1]"),
    /*  38 */ "Gt"               OpHelp("IF r[P3]>r[P1]"),
    /*  39 */ "Le"               OpHelp("IF r[P3]<=r[P1]"),
    /*  40 */ "Lt"               OpHelp("IF r[P3]<r[P1]"),
    /*  41 */ "Ge"               OpHelp("IF r[P3]>=r[P1]"),
    /*  42 */ "ElseNotEq"        OpHelp(""),
    /*  43 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),
    /*  44 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),
    /*  45 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<<r[P1]"),
    /*  46 */ "ShiftRight"       OpHelp("r[P3]=r[P2]>>r[P1]"),
    /*  47 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),
    /*  48 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),
    /*  49 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),
    /*  50 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),
    /*  51 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),
    /*  52 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),
    /*  53 */ "Last"             OpHelp(""),
    /*  54 */ "BitNot"           OpHelp("r[P1]= ~r[P1]"),
    /*  55 */ "SorterSort"       OpHelp(""),
    /*  56 */ "Sort"             OpHelp(""),
    /*  57 */ "Rewind"           OpHelp(""),
    /*  58 */ "IdxLE"            OpHelp("key=r[P3@P4]"),
    /*  59 */ "IdxGT"            OpHelp("key=r[P3@P4]"),
    /*  60 */ "IdxLT"            OpHelp("key=r[P3@P4]"),
    /*  61 */ "IdxGE"            OpHelp("key=r[P3@P4]"),
    /*  62 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),
    /*  63 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
    /*  64 */ "Program"          OpHelp(""),
    /*  65 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
    /*  66 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
    /*  67 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]-=P3, goto P2"),
    /*  68 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
    /*  69 */ "IncrVacuum"       OpHelp(""),
    /*  70 */ "VNext"            OpHelp(""),
    /*  71 */ "Init"             OpHelp("Start at P2"),
    /*  72 */ "Return"           OpHelp(""),
    /*  73 */ "EndCoroutine"     OpHelp(""),
    /*  74 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),
    /*  75 */ "Halt"             OpHelp(""),
    /*  76 */ "Integer"          OpHelp("r[P2]=P1"),
    /*  77 */ "Int64"            OpHelp("r[P2]=P4"),
    /*  78 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),
    /*  79 */ "Null"             OpHelp("r[P2..P3]=NULL"),
    /*  80 */ "SoftNull"         OpHelp("r[P1]=NULL"),
    /*  81 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),
    /*  82 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),
    /*  83 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),
    /*  84 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),
    /*  85 */ "SCopy"            OpHelp("r[P2]=r[P1]"),
    /*  86 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),
    /*  87 */ "ResultRow"        OpHelp("output=r[P1@P2]"),
    /*  88 */ "CollSeq"          OpHelp(""),
    /*  89 */ "Function0"        OpHelp("r[P3]=func(r[P2@P5])"),
    /*  90 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),
    /*  91 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),
    /*  92 */ "RealAffinity"     OpHelp(""),
    /*  93 */ "Cast"             OpHelp("affinity(r[P1])"),
    /*  94 */ "Permutation"      OpHelp(""),
    /*  95 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),
    /*  96 */ "Column"           OpHelp("r[P3]=PX"),

    /*  97 */ "String8"          OpHelp("r[P2]='P4'"),
    /*  98 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),
    /*  99 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),
    /* 100 */ "Count"            OpHelp("r[P2]=count()"),
    /* 101 */ "ReadCookie"       OpHelp(""),
    /* 102 */ "SetCookie"        OpHelp(""),
    /* 103 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),
    /* 104 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),
    /* 105 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),
    /* 106 */ "OpenAutoindex"    OpHelp("nColumn=P2"),
    /* 107 */ "OpenEphemeral"    OpHelp("nColumn=P2"),
    /* 108 */ "SorterOpen"       OpHelp(""),
    /* 109 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),
    /* 110 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),
    /* 111 */ "Close"            OpHelp(""),
    /* 112 */ "ColumnsUsed"      OpHelp(""),
    /* 113 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),
    /* 114 */ "NewRowid"         OpHelp("r[P2]=rowid"),
    /* 115 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),
    /* 116 */ "InsertInt"        OpHelp("intkey=P3 data=r[P2]"),
    /* 117 */ "Delete"           OpHelp(""),
    /* 118 */ "ResetCount"       OpHelp(""),
    /* 119 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),
    /* 120 */ "SorterData"       OpHelp("r[P2]=data"),
    /* 121 */ "RowKey"           OpHelp("r[P2]=key"),
    /* 122 */ "RowData"          OpHelp("r[P2]=data"),
    /* 123 */ "Rowid"            OpHelp("r[P2]=rowid"),
    /* 124 */ "NullRow"          OpHelp(""),
    /* 125 */ "SorterInsert"     OpHelp(""),
    /* 126 */ "IdxInsert"        OpHelp("key=r[P2]"),
    /* 127 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),
    /* 128 */ "Seek"             OpHelp("Move P3 to P1.rowid"),
    /* 129 */ "IdxRowid"         OpHelp("r[P2]=rowid"),
    /* 130 */ "Destroy"          OpHelp(""),
    /* 131 */ "Clear"            OpHelp(""),
    /* 132 */ "ResetSorter"      OpHelp(""),

    /* 133 */ "Real"             OpHelp("r[P2]=P4"),
    /* 134 */ "CreateIndex"      OpHelp("r[P2]=root iDb=P1"),
    /* 135 */ "CreateTable"      OpHelp("r[P2]=root iDb=P1"),
    /* 136 */ "ParseSchema"      OpHelp(""),
    /* 137 */ "LoadAnalysis"     OpHelp(""),
    /* 138 */ "DropTable"        OpHelp(""),
    /* 139 */ "DropIndex"        OpHelp(""),
    /* 140 */ "DropTrigger"      OpHelp(""),
    /* 141 */ "IntegrityCk"      OpHelp(""),
    /* 142 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),
    /* 143 */ "Param"            OpHelp(""),
    /* 144 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
    /* 145 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
    /* 146 */ "OffsetLimit"      OpHelp("if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)"),
    /* 147 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 148 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
    /* 149 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
    /* 150 */ "Expire"           OpHelp(""),
    /* 151 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),
    /* 152 */ "VBegin"           OpHelp(""),
    /* 153 */ "VCreate"          OpHelp(""),
    /* 154 */ "VDestroy"         OpHelp(""),
    /* 155 */ "VOpen"            OpHelp(""),
    /* 156 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),
    /* 157 */ "VRename"          OpHelp(""),
    /* 158 */ "Pagecount"        OpHelp(""),
    /* 159 */ "MaxPgcnt"         OpHelp(""),
    /* 160 */ "CursorHint"       OpHelp(""),
    /* 161 */ "Noop"             OpHelp(""),
    /* 162 */ "Explain"          OpHelp(""),
  };
  return azName[i];
}
#endif

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

** then savepoint iSavepoint is also destroyed.
**
** This function may return SQLITE_NOMEM if a memory allocation fails,
** or an IO error code if an IO error occurs while rolling back a 
** savepoint. If no errors occur, SQLITE_OK is returned.
*/ 
SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
  int rc = pPager->errCode;
  
#ifdef SQLITE_ENABLE_ZIPVFS
  if( op==SAVEPOINT_RELEASE ) rc = SQLITE_OK;
#endif

  assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );
  assert( iSavepoint>=0 || op==SAVEPOINT_ROLLBACK );

  if( rc==SQLITE_OK && iSavepoint<pPager->nSavepoint ){
    int ii;            /* Iterator variable */
    int nNew;          /* Number of remaining savepoints after this op. */

    ** the database file, so the playback operation can be skipped.
    */
    else if( pagerUseWal(pPager) || isOpen(pPager->jfd) ){
      PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
      rc = pagerPlaybackSavepoint(pPager, pSavepoint);
      assert(rc!=SQLITE_DONE);
    }
    
#ifdef SQLITE_ENABLE_ZIPVFS
    /* If the cache has been modified but the savepoint cannot be rolled 
    ** back journal_mode=off, put the pager in the error state. This way,
    ** if the VFS used by this pager includes ZipVFS, the entire transaction
    ** can be rolled back at the ZipVFS level.  */
    else if( 
        pPager->journalMode==PAGER_JOURNALMODE_OFF 
     && pPager->eState>=PAGER_WRITER_CACHEMOD
    ){
      pPager->errCode = SQLITE_ABORT;
      pPager->eState = PAGER_ERROR;
    }
#endif
  }

  return rc;
}

/*
** Return the full pathname of the database file.

    p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
    p->pDestDb = pDestDb;
    p->pSrcDb = pSrcDb;
    p->iNext = 1;
    p->isAttached = 0;

    if( 0==p->pSrc || 0==p->pDest 

     || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 
     ){
      /* One (or both) of the named databases did not exist or an OOM
      ** error was hit. Or there is a transaction open on the destination
      ** database. The error has already been written into the pDestDb 
      ** handle. All that is left to do here is free the sqlite3_backup 
      ** structure.  */

    */
    if( p->pDestDb && p->pSrc->pBt->inTransaction==TRANS_WRITE ){
      rc = SQLITE_BUSY;
    }else{
      rc = SQLITE_OK;
    }









    /* If there is no open read-transaction on the source database, open
    ** one now. If a transaction is opened here, then it will be closed
    ** before this function exits.
    */
    if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){
      rc = sqlite3BtreeBeginTrans(p->pSrc, 0);
      bCloseTrans = 1;
    }

    /* If the destination database has not yet been locked (i.e. if this
    ** is the first call to backup_step() for the current backup operation),
    ** try to set its page size to the same as the source database. This
    ** is especially important on ZipVFS systems, as in that case it is
    ** not possible to create a database file that uses one page size by
    ** writing to it with another.  */
    if( p->bDestLocked==0 && rc==SQLITE_OK && setDestPgsz(p)==SQLITE_NOMEM ){
      rc = SQLITE_NOMEM;
    }

    /* Lock the destination database, if it is not locked already. */
    if( SQLITE_OK==rc && p->bDestLocked==0
     && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2)) 
    ){
      p->bDestLocked = 1;
      sqlite3BtreeGetMeta(p->pDest, BTREE_SCHEMA_VERSION, &p->iDestSchema);
    }

    /* Do not allow backup if the destination database is in WAL mode
    ** and the page sizes are different between source and destination */
    pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);
    pgszDest = sqlite3BtreeGetPageSize(p->pDest);
    destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest));
    if( SQLITE_OK==rc && destMode==PAGER_JOURNALMODE_WAL && pgszSrc!=pgszDest ){

}

/*
** This function is used to allocate and populate UnpackedRecord 
** structures intended to be compared against sample index keys stored 
** in the sqlite_stat4 table.
**
** A single call to this function populates zero or more fields of the
** record starting with field iVal (fields are numbered from left to
** right starting with 0). A single field is populated if:
**
**  * (pExpr==0). In this case the value is assumed to be an SQL NULL,
**
**  * The expression is a bound variable, and this is a reprepare, or
**
**  * The sqlite3ValueFromExpr() function is able to extract a value 
**    from the expression (i.e. the expression is a literal value).
**
** Or, if pExpr is a TK_VECTOR, one field is populated for each of the
** vector components that match either of the two latter criteria listed
** above.
**
** Before any value is appended to the record, the affinity of the 
** corresponding column within index pIdx is applied to it. Before
** this function returns, output parameter *pnExtract is set to the
** number of values appended to the record.
**
** When this function is called, *ppRec must either point to an object
** allocated by an earlier call to this function, or must be NULL. If it
** is NULL and a value can be successfully extracted, a new UnpackedRecord
** is allocated (and *ppRec set to point to it) before returning.
**
** Unless an error is encountered, SQLITE_OK is returned. It is not an
** error if a value cannot be extracted from pExpr. If an error does
** occur, an SQLite error code is returned.
*/
SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
  Parse *pParse,                  /* Parse context */
  Index *pIdx,                    /* Index being probed */
  UnpackedRecord **ppRec,         /* IN/OUT: Probe record */
  Expr *pExpr,                    /* The expression to extract a value from */
  int nElem,                      /* Maximum number of values to append */
  int iVal,                       /* Array element to populate */
  int *pnExtract                  /* OUT: Values appended to the record */
){
  int rc = SQLITE_OK;
  int nExtract = 0;

  if( pExpr==0 || pExpr->op!=TK_SELECT ){
    int i;
    struct ValueNewStat4Ctx alloc;

    alloc.pParse = pParse;
    alloc.pIdx = pIdx;
    alloc.ppRec = ppRec;

    for(i=0; i<nElem; i++){
      sqlite3_value *pVal = 0;
      Expr *pElem = (pExpr ? sqlite3VectorFieldSubexpr(pExpr, i) : 0);
      u8 aff = sqlite3IndexColumnAffinity(pParse->db, pIdx, iVal+i);
      alloc.iVal = iVal+i;
      rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal);
      if( !pVal ) break;
      nExtract++;
    }
  }


  *pnExtract = nExtract;
  return rc;
}

/*
** Attempt to extract a value from expression pExpr using the methods
** as described for sqlite3Stat4ProbeSetValue() above. 
**

  char *zTemp,       /* Write result here */
  int nTemp          /* Space available in zTemp[] */
){
  const char *zOpName;
  const char *zSynopsis;
  int nOpName;
  int ii, jj;
  char zAlt[50];
  zOpName = sqlite3OpcodeName(pOp->opcode);
  nOpName = sqlite3Strlen30(zOpName);
  if( zOpName[nOpName+1] ){
    int seenCom = 0;
    char c;
    zSynopsis = zOpName += nOpName + 1;
    if( strncmp(zSynopsis,"IF ",3)==0 ){
      if( pOp->p5 & SQLITE_STOREP2 ){
        sqlite3_snprintf(sizeof(zAlt), zAlt, "r[P2] = (%s)", zSynopsis+3);
      }else{
        sqlite3_snprintf(sizeof(zAlt), zAlt, "if %s goto P2", zSynopsis+3);
      }
      zSynopsis = zAlt;
    }
    for(ii=jj=0; jj<nTemp-1 && (c = zSynopsis[ii])!=0; ii++){
      if( c=='P' ){
        c = zSynopsis[++ii];
        if( c=='4' ){
          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", zP4);
        }else if( c=='X' ){
          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", pOp->zComment);

#ifdef SQLITE_DEBUG
  int nExtraDelete = 0;      /* Verifies FORDELETE and AUXDELETE flags */
#endif
  int rc = SQLITE_OK;        /* Value to return */
  sqlite3 *db = p->db;       /* The database */
  u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */
  u8 encoding = ENC(db);     /* The database encoding */
  int iCompare = 0;          /* Result of last comparison */
  unsigned nVmStep = 0;      /* Number of virtual machine steps */
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  unsigned nProgressLimit = 0;/* Invoke xProgress() when nVmStep reaches this */
#endif
  Mem *aMem = p->aMem;       /* Copy of p->aMem */
  Mem *pIn1 = 0;             /* 1st input operand */
  Mem *pIn2 = 0;             /* 2nd input operand */

  pIn1->u.i = (int)(pOp - aOp);
  REGISTER_TRACE(pOp->p1, pIn1);
  pOp = &aOp[pcDest];
  break;
}

/* Opcode:  HaltIfNull  P1 P2 P3 P4 P5
** Synopsis: if r[P3]=null halt
**
** Check the value in register P3.  If it is NULL then Halt using
** parameter P1, P2, and P4 as if this were a Halt instruction.  If the
** value in register P3 is not NULL, then this routine is a no-op.
** The P5 parameter should be 1.
*/
case OP_HaltIfNull: {      /* in3 */

    if( pIn3->u.i==pOp->p5 ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
  }
#endif
  break;
}

/* Opcode: Null P1 P2 P3 * *
** Synopsis: r[P2..P3]=NULL
**
** Write a NULL into registers P2.  If P3 greater than P2, then also write
** NULL into register P3 and every register in between P2 and P3.  If P3
** is less than P2 (typically P3 is zero) then only register P2 is
** set to NULL.
**
** If the P1 value is non-zero, then also set the MEM_Cleared flag so that

    pOut->flags = nullFlag;
    cnt--;
  }
  break;
}

/* Opcode: SoftNull P1 * * * *
** Synopsis: r[P1]=NULL
**
** Set register P1 to have the value NULL as seen by the OP_MakeRecord
** instruction, but do not free any string or blob memory associated with
** the register, so that if the value was a string or blob that was
** previously copied using OP_SCopy, the copies will continue to be valid.
*/
case OP_SoftNull: {

  pOut = out2Prerelease(p, pOp);
  sqlite3VdbeMemShallowCopy(pOut, pVar, MEM_Static);
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Move P1 P2 P3 * *
** Synopsis: r[P2@P3]=r[P1@P3]
**
** Move the P3 values in register P1..P1+P3-1 over into
** registers P2..P2+P3-1.  Registers P1..P1+P3-1 are
** left holding a NULL.  It is an error for register ranges
** P1..P1+P3-1 and P2..P2+P3-1 to overlap.  It is an error
** for P3 to be less than 1.
*/

  assert( (pIn1->flags & MEM_Int)!=0 );
  pOut = &aMem[pOp->p2];
  sqlite3VdbeMemSetInt64(pOut, pIn1->u.i);
  break;
}

/* Opcode: ResultRow P1 P2 * * *
** Synopsis: output=r[P1@P2]
**
** The registers P1 through P1+P2-1 contain a single row of
** results. This opcode causes the sqlite3_step() call to terminate
** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
** structure to provide access to the r(P1)..r(P1+P2-1) values as
** the result row.
*/

  pOut->n = (int)nByte;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Add P1 P2 P3 * *
** Synopsis: r[P3]=r[P1]+r[P2]
**
** Add the value in register P1 to the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Multiply P1 P2 P3 * *
** Synopsis: r[P3]=r[P1]*r[P2]
**
**
** Multiply the value in register P1 by the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Subtract P1 P2 P3 * *
** Synopsis: r[P3]=r[P2]-r[P1]
**
** Subtract the value in register P1 from the value in register P2
** and store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: Divide P1 P2 P3 * *
** Synopsis: r[P3]=r[P2]/r[P1]
**
** Divide the value in register P1 by the value in register P2
** and store the result in register P3 (P3=P2/P1). If the value in 
** register P1 is zero, then the result is NULL. If either input is 
** NULL, the result is NULL.
*/
/* Opcode: Remainder P1 P2 P3 * *
** Synopsis: r[P3]=r[P2]%r[P1]
**
** Compute the remainder after integer register P2 is divided by 
** register P1 and store the result in register P3. 
** If the value in register P1 is zero the result is NULL.
** If either operand is NULL, the result is NULL.
*/
case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */

  REGISTER_TRACE(pOp->p3, pCtx->pOut);
  UPDATE_MAX_BLOBSIZE(pCtx->pOut);
  break;
}

/* Opcode: BitAnd P1 P2 P3 * *
** Synopsis: r[P3]=r[P1]&r[P2]
**
** Take the bit-wise AND of the values in register P1 and P2 and
** store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: BitOr P1 P2 P3 * *
** Synopsis: r[P3]=r[P1]|r[P2]
**
** Take the bit-wise OR of the values in register P1 and P2 and
** store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: ShiftLeft P1 P2 P3 * *
** Synopsis: r[P3]=r[P2]<<r[P1]
**
** Shift the integer value in register P2 to the left by the
** number of bits specified by the integer in register P1.
** Store the result in register P3.
** If either input is NULL, the result is NULL.
*/
/* Opcode: ShiftRight P1 P2 P3 * *
** Synopsis: r[P3]=r[P2]>>r[P1]
**
** Shift the integer value in register P2 to the right by the
** number of bits specified by the integer in register P1.
** Store the result in register P3.
** If either input is NULL, the result is NULL.
*/
case OP_BitAnd:                 /* same as TK_BITAND, in1, in2, out3 */

  }
  pOut->u.i = iA;
  MemSetTypeFlag(pOut, MEM_Int);
  break;
}

/* Opcode: AddImm  P1 P2 * * *
** Synopsis: r[P1]=r[P1]+P2
** 
** Add the constant P2 to the value in register P1.
** The result is always an integer.
**
** To force any register to be an integer, just add 0.
*/
case OP_AddImm: {            /* in1 */

  sqlite3VdbeMemCast(pIn1, pOp->p2, encoding);
  UPDATE_MAX_BLOBSIZE(pIn1);
  if( rc ) goto abort_due_to_error;
  break;
}
#endif /* SQLITE_OMIT_CAST */

/* Opcode: Eq P1 P2 P3 P4 P5
** Synopsis: IF r[P3]==r[P1]
**
** Compare the values in register P1 and P3.  If reg(P3)==reg(P1) then
** jump to address P2.  Or if the SQLITE_STOREP2 flag is set in P5, then
** store the result of comparison in register P2.
**
** The SQLITE_AFF_MASK portion of P5 must be an affinity character -
** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made 
** to coerce both inputs according to this affinity before the
** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric
** affinity is used. Note that the affinity conversions are stored
** back into the input registers P1 and P3.  So this opcode can cause
** persistent changes to registers P1 and P3.
**
** Once any conversions have taken place, and neither value is NULL, 
** the values are compared. If both values are blobs then memcmp() is
** used to determine the results of the comparison.  If both values
** are text, then the appropriate collating function specified in
** P4 is used to do the comparison.  If P4 is not specified then
** memcmp() is used to compare text string.  If both values are
** numeric, then a numeric comparison is used. If the two values
** are of different types, then numbers are considered less than
** strings and strings are considered less than blobs.
**
** If SQLITE_NULLEQ is set in P5 then the result of comparison is always either
** true or false and is never NULL.  If both operands are NULL then the result
** of comparison is true.  If either operand is NULL then the result is false.
** If neither operand is NULL the result is the same as it would be if
** the SQLITE_NULLEQ flag were omitted from P5.
**
** If both SQLITE_STOREP2 and SQLITE_KEEPNULL flags are set then the
** content of r[P2] is only changed if the new value is NULL or 0 (false).
** In other words, a prior r[P2] value will not be overwritten by 1 (true).
*/
/* Opcode: Ne P1 P2 P3 P4 P5
** Synopsis: IF r[P3]!=r[P1]
**
** This works just like the Eq opcode except that the jump is taken if
** the operands in registers P1 and P3 are not equal.  See the Eq opcode for
** additional information.
**
** If both SQLITE_STOREP2 and SQLITE_KEEPNULL flags are set then the
** content of r[P2] is only changed if the new value is NULL or 1 (true).
** In other words, a prior r[P2] value will not be overwritten by 0 (false).
*/
/* Opcode: Lt P1 P2 P3 P4 P5
** Synopsis: IF r[P3]<r[P1]
**
** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then
** jump to address P2.  Or if the SQLITE_STOREP2 flag is set in P5 store
** the result of comparison (0 or 1 or NULL) into register P2.
**
** If the SQLITE_JUMPIFNULL bit of P5 is set and either reg(P1) or
** reg(P3) is NULL then the take the jump.  If the SQLITE_JUMPIFNULL 
** bit is clear then fall through if either operand is NULL.
**
** The SQLITE_AFF_MASK portion of P5 must be an affinity character -
** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made 
** to coerce both inputs according to this affinity before the
** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric
** affinity is used. Note that the affinity conversions are stored
** back into the input registers P1 and P3.  So this opcode can cause
** persistent changes to registers P1 and P3.
**
** Once any conversions have taken place, and neither value is NULL, 
** the values are compared. If both values are blobs then memcmp() is
** used to determine the results of the comparison.  If both values
** are text, then the appropriate collating function specified in
** P4 is  used to do the comparison.  If P4 is not specified then
** memcmp() is used to compare text string.  If both values are
** numeric, then a numeric comparison is used. If the two values
** are of different types, then numbers are considered less than
** strings and strings are considered less than blobs.







*/


























/* Opcode: Le P1 P2 P3 P4 P5
** Synopsis: IF r[P3]<=r[P1]
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is less than or equal to the content of
** register P1.  See the Lt opcode for additional information.
*/
/* Opcode: Gt P1 P2 P3 P4 P5
** Synopsis: IF r[P3]>r[P1]
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is greater than the content of
** register P1.  See the Lt opcode for additional information.
*/
/* Opcode: Ge P1 P2 P3 P4 P5
** Synopsis: IF r[P3]>=r[P1]
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is greater than or equal to the content of
** register P1.  See the Lt opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, jump, in1, in3 */
case OP_Ne:               /* same as TK_NE, jump, in1, in3 */
case OP_Lt:               /* same as TK_LT, jump, in1, in3 */
case OP_Le:               /* same as TK_LE, jump, in1, in3 */
case OP_Gt:               /* same as TK_GT, jump, in1, in3 */
case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
  int res, res2;      /* Result of the comparison of pIn1 against pIn3 */
  char affinity;      /* Affinity to use for comparison */
  u16 flags1;         /* Copy of initial value of pIn1->flags */
  u16 flags3;         /* Copy of initial value of pIn3->flags */

  pIn1 = &aMem[pOp->p1];
  pIn3 = &aMem[pOp->p3];
  flags1 = pIn1->flags;

      assert( pOp->opcode==OP_Eq || pOp->opcode==OP_Ne );
      assert( (flags1 & MEM_Cleared)==0 );
      assert( (pOp->p5 & SQLITE_JUMPIFNULL)==0 );
      if( (flags1&MEM_Null)!=0
       && (flags3&MEM_Null)!=0
       && (flags3&MEM_Cleared)==0
      ){
        res = 0;  /* Operands are equal */
      }else{
        res = 1;  /* Operands are not equal */
      }
    }else{
      /* SQLITE_NULLEQ is clear and at least one operand is NULL,
      ** then the result is always NULL.
      ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
      */
      if( pOp->p5 & SQLITE_STOREP2 ){
        pOut = &aMem[pOp->p2];
        iCompare = 1;    /* Operands are not equal */
        memAboutToChange(p, pOut);
        MemSetTypeFlag(pOut, MEM_Null);
        REGISTER_TRACE(pOp->p2, pOut);
      }else{
        VdbeBranchTaken(2,3);
        if( pOp->p5 & SQLITE_JUMPIFNULL ){
          goto jump_to_p2;

    if( flags3 & MEM_Zero ){
      sqlite3VdbeMemExpandBlob(pIn3);
      flags3 &= ~MEM_Zero;
    }
    res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
  }
  switch( pOp->opcode ){
    case OP_Eq:    res2 = res==0;     break;
    case OP_Ne:    res2 = res;        break;
    case OP_Lt:    res2 = res<0;      break;
    case OP_Le:    res2 = res<=0;     break;
    case OP_Gt:    res2 = res>0;      break;
    default:       res2 = res>=0;     break;
  }

  /* Undo any changes made by applyAffinity() to the input registers. */
  assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );
  pIn1->flags = flags1;
  assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );
  pIn3->flags = flags3;

  if( pOp->p5 & SQLITE_STOREP2 ){
    pOut = &aMem[pOp->p2];
    iCompare = res;
    res2 = res2!=0;  /* For this path res2 must be exactly 0 or 1 */
    if( (pOp->p5 & SQLITE_KEEPNULL)!=0 ){
      /* The KEEPNULL flag prevents OP_Eq from overwriting a NULL with 1
      ** and prevents OP_Ne from overwriting NULL with 0.  This flag
      ** is only used in contexts where either:
      **   (1) op==OP_Eq && (r[P2]==NULL || r[P2]==0)
      **   (2) op==OP_Ne && (r[P2]==NULL || r[P2]==1)
      ** Therefore it is not necessary to check the content of r[P2] for
      ** NULL. */
      assert( pOp->opcode==OP_Ne || pOp->opcode==OP_Eq );
      assert( res2==0 || res2==1 );
      testcase( res2==0 && pOp->opcode==OP_Eq );
      testcase( res2==1 && pOp->opcode==OP_Eq );
      testcase( res2==0 && pOp->opcode==OP_Ne );
      testcase( res2==1 && pOp->opcode==OP_Ne );
      if( (pOp->opcode==OP_Eq)==res2 ) break;
    }
    memAboutToChange(p, pOut);
    MemSetTypeFlag(pOut, MEM_Int);
    pOut->u.i = res2;
    REGISTER_TRACE(pOp->p2, pOut);
  }else{
    VdbeBranchTaken(res!=0, (pOp->p5 & SQLITE_NULLEQ)?2:3);
    if( res2 ){
      goto jump_to_p2;
    }
  }
  break;
}

/* Opcode: ElseNotEq * P2 * * *
**
** This opcode must immediately follow an Lt or Gt comparison operator.
** If the operands in that previous comparison had been used with an Eq
** operator and if the result of that Eq would be NULL or false (0), then
** then jump to P2.  If the result of comparing the two previous operands
** using Eq would have been true (1), then fall through.
*/
case OP_ElseNotEq: {       /* same as TK_ESCAPE, jump */
  assert( pOp>aOp );
  assert( pOp[-1].opcode==OP_Lt || pOp[-1].opcode==OP_Gt );
  assert( pOp[-1].p5 & SQLITE_STOREP2 );
  VdbeBranchTaken(iCompare!=0, 2);
  if( iCompare!=0 ) goto jump_to_p2;
  break;
}


/* Opcode: Permutation * * * P4 *
**
** Set the permutation used by the OP_Compare operator to be the array
** of integers in P4.
**
** The permutation is only valid until the next OP_Compare that has

  if( c ){
    goto jump_to_p2;
  }
  break;
}

/* Opcode: IsNull P1 P2 * * *
** Synopsis: if r[P1]==NULL goto P2
**
** Jump to P2 if the value in register P1 is NULL.
*/
case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */
  pIn1 = &aMem[pOp->p1];
  VdbeBranchTaken( (pIn1->flags & MEM_Null)!=0, 2);
  if( (pIn1->flags & MEM_Null)!=0 ){

  if( (pIn1->flags & MEM_Null)==0 ){
    goto jump_to_p2;
  }
  break;
}

/* Opcode: Column P1 P2 P3 P4 P5
** Synopsis: r[P3]=PX
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
** information about the format of the data.)  Extract the P2-th column
** from this record.  If there are less that (P2+1) 
** values in the record, extract a NULL.
**

    goto jump_to_p2;
  }else if( eqOnly ){
    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
    pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */
  }
  break;
}


/* Opcode: Found P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
** P4>0 then register P3 is the first of P4 registers that form an unpacked
** record.

** value of register P2 will then change.  Make sure this does not
** cause any problems.)
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/
/* Opcode: InsertInt P1 P2 P3 P4 P5
** Synopsis: intkey=P3 data=r[P2]
**
** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert: 
case OP_InsertInt: {
  Mem *pData;       /* MEM cell holding data for the record to be inserted */

case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}

/* Opcode: SorterCompare P1 P2 P3 P4
** Synopsis: if key(P1)!=trim(r[P3],P4) goto P2
**
** P1 is a sorter cursor. This instruction compares a prefix of the
** record blob in register P3 against a prefix of the entry that 
** the sorter cursor currently points to.  Only the first P4 fields
** of r[P3] and the sorter record are compared.
**
** If either P3 or the sorter contains a NULL in one of their significant

  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  break;
}

/* Opcode: Seek P1 * P3 P4 *
** Synopsis: Move P3 to P1.rowid
**
** P1 is an open index cursor and P3 is a cursor on the corresponding
** table.  This opcode does a deferred seek of the P3 table cursor
** to the row that corresponds to the current row of P1.
**
** This is a deferred seek.  Nothing actually happens until
** the cursor is used to read a record.  That way, if no reads

  UPDATE_MAX_BLOBSIZE(pIn1);
  sqlite3VdbeChangeEncoding(pIn1, encoding);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/* Opcode: RowSetAdd P1 P2 * * *
** Synopsis: rowset(P1)=r[P2]
**
** Insert the integer value held by register P2 into a boolean index
** held in register P1.
**
** An assertion fails if P2 is not an integer.
*/
case OP_RowSetAdd: {       /* in1, in2 */
  pIn1 = &aMem[pOp->p1];
  pIn2 = &aMem[pOp->p2];
  assert( (pIn2->flags & MEM_Int)!=0 );
  if( (pIn1->flags & MEM_RowSet)==0 ){
    sqlite3VdbeMemSetRowSet(pIn1);
    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
  }
  sqlite3RowSetInsert(pIn1->u.pRowSet, pIn2->u.i);
  break;
}

/* Opcode: RowSetRead P1 P2 P3 * *
** Synopsis: r[P3]=rowset(P1)
**
** Extract the smallest value from boolean index P1 and put that value into
** register P3.  Or, if boolean index P1 is initially empty, leave P3
** unchanged and jump to instruction P2.
*/
case OP_RowSetRead: {       /* jump, in1, out3 */
  i64 val;

  pOut->u.i = sqlite3BtreeMaxPageCount(pBt, newMax);
  break;
}
#endif


/* Opcode: Init * P2 * P4 *
** Synopsis: Start at P2
**
** Programs contain a single instance of this opcode as the very first
** opcode.
**
** If tracing is enabled (by the sqlite3_trace()) interface, then
** the UTF-8 string contained in P4 is emitted on the trace callback.
** Or if P4 is blank, use the string returned by sqlite3_sql().

  if( (db->flags & SQLITE_SqlTrace)!=0
   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
  ){
    sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);
  }
#endif /* SQLITE_DEBUG */
#endif /* SQLITE_OMIT_TRACE */
  assert( pOp->p2>0 );
  goto jump_to_p2;

}

#ifdef SQLITE_ENABLE_CURSOR_HINTS
/* Opcode: CursorHint P1 * * P4 *
**
** Provide a hint to cursor P1 that it only needs to return rows that
** satisfy the Expr in P4.  TK_REGISTER terms in the P4 expression refer

      }
      break;
    }
    case TK_VARIABLE: {
      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
      break;
    }
    case TK_EQ:
    case TK_NE:
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_IS:
    case TK_ISNOT: {
      int nLeft, nRight;
      if( pParse->db->mallocFailed ) break;
      assert( pExpr->pRight!=0 );
      assert( pExpr->pLeft!=0 );
      nLeft = sqlite3ExprVectorSize(pExpr->pLeft);
      nRight = sqlite3ExprVectorSize(pExpr->pRight);
      if( nLeft!=nRight ){
        testcase( pExpr->op==TK_EQ );
        testcase( pExpr->op==TK_NE );
        testcase( pExpr->op==TK_LT );
        testcase( pExpr->op==TK_LE );
        testcase( pExpr->op==TK_GT );
        testcase( pExpr->op==TK_GE );
        testcase( pExpr->op==TK_IS );
        testcase( pExpr->op==TK_ISNOT );
        sqlite3ErrorMsg(pParse, "row value misused");
      }
      break; 
    }
  }
  return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
}

/*
** pEList is a list of expressions which are really the result set of the
** a SELECT statement.  pE is a term in an ORDER BY or GROUP BY clause.

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
*/
/* #include "sqliteInt.h" */

/* Forward declarations */
static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);
static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);

/*
** Return the affinity character for a single column of a table.
*/
SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table *pTab, int iCol){
  assert( iCol<pTab->nCol );
  return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
}

/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the 
** affinity of that column is returned. Otherwise, 0x00 is returned,

  pExpr = sqlite3ExprSkipCollate(pExpr);
  if( pExpr->flags & EP_Generic ) return 0;
  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
  }
  if( op==TK_REGISTER ) op = pExpr->op2;
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
    assert( !ExprHasProperty(pExpr, EP_IntValue) );
    return sqlite3AffinityType(pExpr->u.zToken, 0);
  }
#endif
  if( op==TK_AGG_COLUMN || op==TK_COLUMN ){
    return sqlite3TableColumnAffinity(pExpr->pTab, pExpr->iColumn);

  }
  if( op==TK_SELECT_COLUMN ){

    assert( pExpr->pLeft->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(

        pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
    );
  }
  return pExpr->affinity;
}

/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken.   Return a pointer to a new Expr node that

          pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
  assert( pExpr->pLeft );
  aff = sqlite3ExprAffinity(pExpr->pLeft);
  if( pExpr->pRight ){
    aff = sqlite3CompareAffinity(pExpr->pRight, aff);
  }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
    aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
  }else if( NEVER(aff==0) ){
    aff = SQLITE_AFF_BLOB;
  }
  return aff;
}

/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.

  p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
  p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
  addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
                           (void*)p4, P4_COLLSEQ);
  sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
  return addr;
}

/*
** Return true if expression pExpr is a vector, or false otherwise.
**
** A vector is defined as any expression that results in two or more
** columns of result.  Every TK_VECTOR node is an vector because the
** parser will not generate a TK_VECTOR with fewer than two entries.
** But a TK_SELECT might be either a vector or a scalar. It is only
** considered a vector if it has two or more result columns.
*/
SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr){
  return sqlite3ExprVectorSize(pExpr)>1;
}

/*
** If the expression passed as the only argument is of type TK_VECTOR 
** return the number of expressions in the vector. Or, if the expression
** is a sub-select, return the number of columns in the sub-select. For
** any other type of expression, return 1.
*/
SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr){
  u8 op = pExpr->op;
  if( op==TK_REGISTER ) op = pExpr->op2;
  if( op==TK_VECTOR ){
    return pExpr->x.pList->nExpr;
  }else if( op==TK_SELECT ){
    return pExpr->x.pSelect->pEList->nExpr;
  }else{
    return 1;
  }
}

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Return a pointer to a subexpression of pVector that is the i-th
** column of the vector (numbered starting with 0).  The caller must
** ensure that i is within range.
**
** If pVector is really a scalar (and "scalar" here includes subqueries
** that return a single column!) then return pVector unmodified.
**
** pVector retains ownership of the returned subexpression.
**
** If the vector is a (SELECT ...) then the expression returned is
** just the expression for the i-th term of the result set, and may
** not be ready for evaluation because the table cursor has not yet
** been positioned.
*/
SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){
  assert( i<sqlite3ExprVectorSize(pVector) );
  if( sqlite3ExprIsVector(pVector) ){
    assert( pVector->op2==0 || pVector->op==TK_REGISTER );
    if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){
      return pVector->x.pSelect->pEList->a[i].pExpr;
    }else{
      return pVector->x.pList->a[i].pExpr;
    }
  }
  return pVector;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) */

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Compute and return a new Expr object which when passed to
** sqlite3ExprCode() will generate all necessary code to compute
** the iField-th column of the vector expression pVector.
**
** It is ok for pVector to be a scalar (as long as iField==0).  
** In that case, this routine works like sqlite3ExprDup().
**
** The caller owns the returned Expr object and is responsible for
** ensuring that the returned value eventually gets freed.
**
** The caller retains ownership of pVector.  If pVector is a TK_SELECT,
** then the returned object will reference pVector and so pVector must remain
** valid for the life of the returned object.  If pVector is a TK_VECTOR
** or a scalar expression, then it can be deleted as soon as this routine
** returns.
**
** A trick to cause a TK_SELECT pVector to be deleted together with
** the returned Expr object is to attach the pVector to the pRight field
** of the returned TK_SELECT_COLUMN Expr object.
*/
SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(
  Parse *pParse,       /* Parsing context */
  Expr *pVector,       /* The vector.  List of expressions or a sub-SELECT */
  int iField           /* Which column of the vector to return */
){
  Expr *pRet;
  if( pVector->op==TK_SELECT ){
    assert( pVector->flags & EP_xIsSelect );
    /* The TK_SELECT_COLUMN Expr node:
    **
    ** pLeft:           pVector containing TK_SELECT
    ** pRight:          not used.  But recursively deleted.
    ** iColumn:         Index of a column in pVector
    ** pLeft->iTable:   First in an array of register holding result, or 0
    **                  if the result is not yet computed.
    **
    ** sqlite3ExprDelete() specifically skips the recursive delete of
    ** pLeft on TK_SELECT_COLUMN nodes.  But pRight is followed, so pVector
    ** can be attached to pRight to cause this node to take ownership of
    ** pVector.  Typically there will be multiple TK_SELECT_COLUMN nodes
    ** with the same pLeft pointer to the pVector, but only one of them
    ** will own the pVector.
    */
    pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0, 0);
    if( pRet ){
      pRet->iColumn = iField;
      pRet->pLeft = pVector;
    }
    assert( pRet==0 || pRet->iTable==0 );
  }else{
    if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
    pRet = sqlite3ExprDup(pParse->db, pVector, 0);
  }
  return pRet;
}
#endif /* !define(SQLITE_OMIT_SUBQUERY) */

/*
** If expression pExpr is of type TK_SELECT, generate code to evaluate
** it. Return the register in which the result is stored (or, if the 
** sub-select returns more than one column, the first in an array
** of registers in which the result is stored).
**
** If pExpr is not a TK_SELECT expression, return 0.
*/
static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
  int reg = 0;
#ifndef SQLITE_OMIT_SUBQUERY
  if( pExpr->op==TK_SELECT ){
    reg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
  }
#endif
  return reg;
}

/*
** Argument pVector points to a vector expression - either a TK_VECTOR
** or TK_SELECT that returns more than one column. This function returns
** the register number of a register that contains the value of
** element iField of the vector.
**
** If pVector is a TK_SELECT expression, then code for it must have 
** already been generated using the exprCodeSubselect() routine. In this
** case parameter regSelect should be the first in an array of registers
** containing the results of the sub-select. 
**
** If pVector is of type TK_VECTOR, then code for the requested field
** is generated. In this case (*pRegFree) may be set to the number of
** a temporary register to be freed by the caller before returning.
**
** Before returning, output parameter (*ppExpr) is set to point to the
** Expr object corresponding to element iElem of the vector.
*/
static int exprVectorRegister(
  Parse *pParse,                  /* Parse context */
  Expr *pVector,                  /* Vector to extract element from */
  int iField,                     /* Field to extract from pVector */
  int regSelect,                  /* First in array of registers */
  Expr **ppExpr,                  /* OUT: Expression element */
  int *pRegFree                   /* OUT: Temp register to free */
){
  u8 op = pVector->op;
  assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );
  if( op==TK_REGISTER ){
    *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);
    return pVector->iTable+iField;
  }
  if( op==TK_SELECT ){
    *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;
     return regSelect+iField;
  }
  *ppExpr = pVector->x.pList->a[iField].pExpr;
  return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);
}

/*
** Expression pExpr is a comparison between two vector values. Compute
** the result of the comparison (1, 0, or NULL) and write that
** result into register dest.
**
** The caller must satisfy the following preconditions:
**
**    if pExpr->op==TK_IS:      op==TK_EQ and p5==SQLITE_NULLEQ
**    if pExpr->op==TK_ISNOT:   op==TK_NE and p5==SQLITE_NULLEQ
**    otherwise:                op==pExpr->op and p5==0
*/
static void codeVectorCompare(
  Parse *pParse,        /* Code generator context */
  Expr *pExpr,          /* The comparison operation */
  int dest,             /* Write results into this register */
  u8 op,                /* Comparison operator */
  u8 p5                 /* SQLITE_NULLEQ or zero */
){
  Vdbe *v = pParse->pVdbe;
  Expr *pLeft = pExpr->pLeft;
  Expr *pRight = pExpr->pRight;
  int nLeft = sqlite3ExprVectorSize(pLeft);
  int i;
  int regLeft = 0;
  int regRight = 0;
  u8 opx = op;
  int addrDone = sqlite3VdbeMakeLabel(v);

  assert( nLeft==sqlite3ExprVectorSize(pRight) );
  assert( pExpr->op==TK_EQ || pExpr->op==TK_NE 
       || pExpr->op==TK_IS || pExpr->op==TK_ISNOT 
       || pExpr->op==TK_LT || pExpr->op==TK_GT 
       || pExpr->op==TK_LE || pExpr->op==TK_GE 
  );
  assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)
            || (pExpr->op==TK_ISNOT && op==TK_NE) );
  assert( p5==0 || pExpr->op!=op );
  assert( p5==SQLITE_NULLEQ || pExpr->op==op );

  p5 |= SQLITE_STOREP2;
  if( opx==TK_LE ) opx = TK_LT;
  if( opx==TK_GE ) opx = TK_GT;

  regLeft = exprCodeSubselect(pParse, pLeft);
  regRight = exprCodeSubselect(pParse, pRight);

  for(i=0; 1 /*Loop exits by "break"*/; i++){
    int regFree1 = 0, regFree2 = 0;
    Expr *pL, *pR; 
    int r1, r2;
    assert( i>=0 && i<nLeft );
    if( i>0 ) sqlite3ExprCachePush(pParse);
    r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);
    r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);
    codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5);
    testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
    testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
    testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
    testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
    testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
    testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
    sqlite3ReleaseTempReg(pParse, regFree1);
    sqlite3ReleaseTempReg(pParse, regFree2);
    if( i>0 ) sqlite3ExprCachePop(pParse);
    if( i==nLeft-1 ){
      break;
    }
    if( opx==TK_EQ ){
      sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);
      p5 |= SQLITE_KEEPNULL;
    }else if( opx==TK_NE ){
      sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);
      p5 |= SQLITE_KEEPNULL;
    }else{
      assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );
      sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);
      VdbeCoverageIf(v, op==TK_LT);
      VdbeCoverageIf(v, op==TK_GT);
      VdbeCoverageIf(v, op==TK_LE);
      VdbeCoverageIf(v, op==TK_GE);
      if( i==nLeft-2 ) opx = op;
    }
  }
  sqlite3VdbeResolveLabel(v, addrDone);
}

#if SQLITE_MAX_EXPR_DEPTH>0
/*
** Check that argument nHeight is less than or equal to the maximum
** expression depth allowed. If it is not, leave an error message in
** pParse.
*/

static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
  assert( p!=0 );
  /* Sanity check: Assert that the IntValue is non-negative if it exists */
  assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
  if( !ExprHasProperty(p, EP_TokenOnly) ){
    /* The Expr.x union is never used at the same time as Expr.pRight */
    assert( p->x.pList==0 || p->pRight==0 );
    if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);
    sqlite3ExprDelete(db, p->pRight);
    if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);
    if( ExprHasProperty(p, EP_xIsSelect) ){
      sqlite3SelectDelete(db, p->x.pSelect);
    }else{
      sqlite3ExprListDelete(db, p->x.pList);
    }

                       exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;
      }
      if( pzBuffer ){
        *pzBuffer = zAlloc;
      }
    }else{
      if( !ExprHasProperty(p, EP_TokenOnly) ){
        if( pNew->op==TK_SELECT_COLUMN ){
          pNew->pLeft = p->pLeft;
        }else{
          pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
        }
        pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
      }
    }
  }
  return pNew;
}

no_mem:     
  /* Avoid leaking memory if malloc has failed. */
  sqlite3ExprDelete(db, pExpr);
  sqlite3ExprListDelete(db, pList);
  return 0;
}

/*
** pColumns and pExpr form a vector assignment which is part of the SET
** clause of an UPDATE statement.  Like this:
**
**        (a,b,c) = (expr1,expr2,expr3)
** Or:    (a,b,c) = (SELECT x,y,z FROM ....)
**
** For each term of the vector assignment, append new entries to the
** expression list pList.  In the case of a subquery on the LHS, append
** TK_SELECT_COLUMN expressions.
*/
SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(
  Parse *pParse,         /* Parsing context */
  ExprList *pList,       /* List to which to append. Might be NULL */
  IdList *pColumns,      /* List of names of LHS of the assignment */
  Expr *pExpr            /* Vector expression to be appended. Might be NULL */
){
  sqlite3 *db = pParse->db;
  int n;
  int i;
  int iFirst = pList ? pList->nExpr : 0;
  /* pColumns can only be NULL due to an OOM but an OOM will cause an
  ** exit prior to this routine being invoked */
  if( NEVER(pColumns==0) ) goto vector_append_error;
  if( pExpr==0 ) goto vector_append_error;
  n = sqlite3ExprVectorSize(pExpr);
  if( pColumns->nId!=n ){
    sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
                    pColumns->nId, n);
    goto vector_append_error;
  }
  for(i=0; i<n; i++){
    Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);
    pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);
    if( pList ){
      assert( pList->nExpr==iFirst+i+1 );
      pList->a[pList->nExpr-1].zName = pColumns->a[i].zName;
      pColumns->a[i].zName = 0;
    }
  }
  if( pExpr->op==TK_SELECT ){
    if( pList && pList->a[iFirst].pExpr ){
      assert( pList->a[iFirst].pExpr->op==TK_SELECT_COLUMN );
      pList->a[iFirst].pExpr->pRight = pExpr;
      pExpr = 0;
    }
  }

vector_append_error:
  sqlite3ExprDelete(db, pExpr);
  sqlite3IdListDelete(db, pColumns);
  return pList;
}

/*
** Set the sort order for the last element on the given ExprList.
*/
SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
  if( p==0 ) return;
  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );

** table, then return NULL.
*/
#ifndef SQLITE_OMIT_SUBQUERY
static Select *isCandidateForInOpt(Expr *pX){
  Select *p;
  SrcList *pSrc;
  ExprList *pEList;

  Table *pTab;
  int i;
  if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0;  /* Not a subquery */
  if( ExprHasProperty(pX, EP_VarSelect)  ) return 0;  /* Correlated subq */
  p = pX->x.pSelect;
  if( p->pPrior ) return 0;              /* Not a compound SELECT */
  if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );

  if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
  if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
  pTab = pSrc->a[0].pTab;
  assert( pTab!=0 );
  assert( pTab->pSelect==0 );            /* FROM clause is not a view */
  if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
  pEList = p->pEList;
  assert( pEList!=0 );
  /* All SELECT results must be columns. */
  for(i=0; i<pEList->nExpr; i++){
    Expr *pRes = pEList->a[i].pExpr;
    if( pRes->op!=TK_COLUMN ) return 0;
    assert( pRes->iTable==pSrc->a[0].iCursor );  /* Not a correlated subquery */
  }
  return p;
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*
** Code an OP_Once instruction and allocate space for its flag. Return the 
** address of the new instruction.
*/
SQLITE_PRIVATE int sqlite3CodeOnce(Parse *pParse){
  Vdbe *v = sqlite3GetVdbe(pParse);      /* Virtual machine being coded */
  return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
}

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code that checks the left-most column of index table iCur to see if
** it contains any NULL entries.  Cause the register at regHasNull to be set
** to a non-NULL value if iCur contains no NULLs.  Cause register regHasNull
** to be set to NULL if iCur contains one or more NULL values.
*/
static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){
  int addr1;
  sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);
  addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
  sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);
  sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
  VdbeComment((v, "first_entry_in(%d)", iCur));
  sqlite3VdbeJumpHere(v, addr1);
}
#endif


#ifndef SQLITE_OMIT_SUBQUERY
/*
** The argument is an IN operator with a list (not a subquery) on the 
** right-hand side.  Return TRUE if that list is constant.
*/

**                         populated epheremal table.
**   IN_INDEX_NOOP       - No cursor was allocated.  The IN operator must be
**                         implemented as a sequence of comparisons.
**
** An existing b-tree might be used if the RHS expression pX is a simple
** subquery such as:
**
**     SELECT <column1>, <column2>... FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephemeral table instead of an
** existing table.
**
** The inFlags parameter must contain exactly one of the bits
** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP.  If inFlags contains
** IN_INDEX_MEMBERSHIP, then the generated table will be used for a
** fast membership test.  When the IN_INDEX_LOOP bit is set, the
** IN index will be used to loop over all values of the RHS of the
** IN operator.
**
** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
** through the set members) then the b-tree must not contain duplicates.
** An epheremal table must be used unless the selected columns are guaranteed
** to be unique - either because it is an INTEGER PRIMARY KEY or due to
** a UNIQUE constraint or index.
**
** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used 
** for fast set membership tests) then an epheremal table must 
** be used unless <columns> is a single INTEGER PRIMARY KEY column or an 
** index can be found with the specified <columns> as its left-most.
**
** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
** if the RHS of the IN operator is a list (not a subquery) then this
** routine might decide that creating an ephemeral b-tree for membership
** testing is too expensive and return IN_INDEX_NOOP.  In that case, the
** calling routine should implement the IN operator using a sequence
** of Eq or Ne comparison operations.
**
** When the b-tree is being used for membership tests, the calling function
** might need to know whether or not the RHS side of the IN operator
** contains a NULL.  If prRhsHasNull is not a NULL pointer and 
** if there is any chance that the (...) might contain a NULL value at
** runtime, then a register is allocated and the register number written
** to *prRhsHasNull. If there is no chance that the (...) contains a
** NULL value, then *prRhsHasNull is left unchanged.
**
** If a register is allocated and its location stored in *prRhsHasNull, then
** the value in that register will be NULL if the b-tree contains one or more
** NULL values, and it will be some non-NULL value if the b-tree contains no
** NULL values.
**
** If the aiMap parameter is not NULL, it must point to an array containing
** one element for each column returned by the SELECT statement on the RHS
** of the IN(...) operator. The i'th entry of the array is populated with the
** offset of the index column that matches the i'th column returned by the
** SELECT. For example, if the expression and selected index are:
**
**   (?,?,?) IN (SELECT a, b, c FROM t1)
**   CREATE INDEX i1 ON t1(b, c, a);
**
** then aiMap[] is populated with {2, 0, 1}.
*/
#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3FindInIndex(
  Parse *pParse,             /* Parsing context */
  Expr *pX,                  /* The right-hand side (RHS) of the IN operator */
  u32 inFlags,               /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
  int *prRhsHasNull,         /* Register holding NULL status.  See notes */
  int *aiMap                 /* Mapping from Index fields to RHS fields */
){
  Select *p;                            /* SELECT to the right of IN operator */
  int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
  int iTab = pParse->nTab++;            /* Cursor of the RHS table */
  int mustBeUnique;                     /* True if RHS must be unique */
  Vdbe *v = sqlite3GetVdbe(pParse);     /* Virtual machine being coded */

  assert( pX->op==TK_IN );
  mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;

  /* If the RHS of this IN(...) operator is a SELECT, and if it matters 
  ** whether or not the SELECT result contains NULL values, check whether
  ** or not NULL is actually possible (it may not be, for example, due 
  ** to NOT NULL constraints in the schema). If no NULL values are possible,
  ** set prRhsHasNull to 0 before continuing.  */
  if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){
    int i;
    ExprList *pEList = pX->x.pSelect->pEList;
    for(i=0; i<pEList->nExpr; i++){
      if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;
    }
    if( i==pEList->nExpr ){
      prRhsHasNull = 0;
    }
  }

  /* Check to see if an existing table or index can be used to
  ** satisfy the query.  This is preferable to generating a new 
  ** ephemeral table.  */

  if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
    sqlite3 *db = pParse->db;              /* Database connection */
    Table *pTab;                           /* Table <table>. */


    i16 iDb;                               /* Database idx for pTab */
    ExprList *pEList = p->pEList;
    int nExpr = pEList->nExpr;

    assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
    assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
    assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
    pTab = p->pSrc->a[0].pTab;



    /* Code an OP_Transaction and OP_TableLock for <table>. */
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    sqlite3CodeVerifySchema(pParse, iDb);
    sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);





    assert(v);  /* sqlite3GetVdbe() has always been previously called */
    if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){
      /* The "x IN (SELECT rowid FROM table)" case */
      int iAddr = sqlite3CodeOnce(pParse);
      VdbeCoverage(v);

      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
      eType = IN_INDEX_ROWID;

      sqlite3VdbeJumpHere(v, iAddr);
    }else{
      Index *pIdx;                         /* Iterator variable */
      int affinity_ok = 1;
      int i;




      /* Check that the affinity that will be used to perform each 
      ** comparison is the same as the affinity of each column in table
      ** on the RHS of the IN operator.  If it not, it is not possible to
      ** use any index of the RHS table.  */
      for(i=0; i<nExpr && affinity_ok; i++){
        Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
        int iCol = pEList->a[i].pExpr->iColumn;
        char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */
        char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);
        testcase( cmpaff==SQLITE_AFF_BLOB );
        testcase( cmpaff==SQLITE_AFF_TEXT );
        switch( cmpaff ){
          case SQLITE_AFF_BLOB:
            break;
          case SQLITE_AFF_TEXT:
            /* sqlite3CompareAffinity() only returns TEXT if one side or the
            ** other has no affinity and the other side is TEXT.  Hence,
            ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
            ** and for the term on the LHS of the IN to have no affinity. */
            assert( idxaff==SQLITE_AFF_TEXT );
            break;
          default:
            affinity_ok = sqlite3IsNumericAffinity(idxaff);
        }
      }

      if( affinity_ok ){
        /* Search for an existing index that will work for this IN operator */
        for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
          Bitmask colUsed;      /* Columns of the index used */
          Bitmask mCol;         /* Mask for the current column */
          if( pIdx->nColumn<nExpr ) continue;
          /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
          ** BITMASK(nExpr) without overflowing */
          testcase( pIdx->nColumn==BMS-2 );
          testcase( pIdx->nColumn==BMS-1 );
          if( pIdx->nColumn>=BMS-1 ) continue;
          if( mustBeUnique ){
            if( pIdx->nKeyCol>nExpr
             ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))
            ){
              continue;  /* This index is not unique over the IN RHS columns */
            }
          }
  
          colUsed = 0;   /* Columns of index used so far */
          for(i=0; i<nExpr; i++){
            Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
            Expr *pRhs = pEList->a[i].pExpr;
            CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
            int j;
  
            assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );
            for(j=0; j<nExpr; j++){
              if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
              assert( pIdx->azColl[j] );
              if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
                continue;
              }
              break;
            }
            if( j==nExpr ) break;
            mCol = MASKBIT(j);
            if( mCol & colUsed ) break; /* Each column used only once */
            colUsed |= mCol;
            if( aiMap ) aiMap[i] = j;
          }
  

          assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );
          if( colUsed==(MASKBIT(nExpr)-1) ){
            /* If we reach this point, that means the index pIdx is usable */
            int iAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
  #ifndef SQLITE_OMIT_EXPLAIN
            sqlite3VdbeAddOp4(v, OP_Explain, 0, 0, 0,
              sqlite3MPrintf(db, "USING INDEX %s FOR IN-OPERATOR",pIdx->zName),
              P4_DYNAMIC);
  #endif
            sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
            sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
            VdbeComment((v, "%s", pIdx->zName));
            assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
            eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
  
            if( prRhsHasNull ){
              *prRhsHasNull = ++pParse->nMem;
  #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
              i64 mask = (1<<nExpr)-1;
              sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, 
                  iTab, 0, 0, (u8*)&mask, P4_INT64);
  #endif

              if( nExpr==1 ){
                sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);
              }
            }
            sqlite3VdbeJumpHere(v, iAddr);
          }


        } /* End loop over indexes */
      } /* End if( affinity_ok ) */
    } /* End if not an rowid index */
  } /* End attempt to optimize using an index */

  /* If no preexisting index is available for the IN clause
  ** and IN_INDEX_NOOP is an allowed reply
  ** and the RHS of the IN operator is a list, not a subquery
  ** and the RHS is not constant or has two or fewer terms,
  ** then it is not worth creating an ephemeral table to evaluate
  ** the IN operator so return IN_INDEX_NOOP.
  */
  if( eType==0
   && (inFlags & IN_INDEX_NOOP_OK)
   && !ExprHasProperty(pX, EP_xIsSelect)
   && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
  ){
    eType = IN_INDEX_NOOP;
  }


  if( eType==0 ){
    /* Could not find an existing table or index to use as the RHS b-tree.
    ** We will have to generate an ephemeral table to do the job.
    */
    u32 savedNQueryLoop = pParse->nQueryLoop;
    int rMayHaveNull = 0;

      *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
    }
    sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;
  }else{
    pX->iTable = iTab;
  }

  if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
    int i, n;
    n = sqlite3ExprVectorSize(pX->pLeft);
    for(i=0; i<n; i++) aiMap[i] = i;
  }
  return eType;
}
#endif

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Argument pExpr is an (?, ?...) IN(...) expression. This 
** function allocates and returns a nul-terminated string containing 
** the affinities to be used for each column of the comparison.
**
** It is the responsibility of the caller to ensure that the returned
** string is eventually freed using sqlite3DbFree().
*/
static char *exprINAffinity(Parse *pParse, Expr *pExpr){
  Expr *pLeft = pExpr->pLeft;
  int nVal = sqlite3ExprVectorSize(pLeft);
  Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;
  char *zRet;

  assert( pExpr->op==TK_IN );
  zRet = sqlite3DbMallocZero(pParse->db, nVal+1);
  if( zRet ){
    int i;
    for(i=0; i<nVal; i++){
      Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);
      char a = sqlite3ExprAffinity(pA);
      if( pSelect ){
        zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);
      }else{
        zRet[i] = a;
      }
    }
    zRet[nVal] = '\0';
  }
  return zRet;
}
#endif

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Load the Parse object passed as the first argument with an error 
** message of the form:
**
**   "sub-select returns N columns - expected M"
*/   
SQLITE_PRIVATE void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){
  const char *zFmt = "sub-select returns %d columns - expected %d";
  sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);
}
#endif

/*
** Generate code for scalar subqueries used as a subquery expression, EXISTS,
** or IN operators.  Examples:
**
**     (SELECT a FROM b)          -- subquery
**     EXISTS (SELECT a FROM b)   -- EXISTS subquery

** If rMayHaveNull is non-zero, that means that the operation is an IN
** (not a SELECT or EXISTS) and that the RHS might contains NULLs.
** All this routine does is initialize the register given by rMayHaveNull
** to NULL.  Calling routines will take care of changing this register
** value to non-NULL if the RHS is NULL-free.
**
** For a SELECT or EXISTS operator, return the register that holds the
** result.  For a multi-column SELECT, the result is stored in a contiguous
** array of registers and the return value is the register of the left-most
** result column.  Return 0 for IN operators or if an error occurs.
*/
#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3CodeSubselect(
  Parse *pParse,          /* Parsing context */
  Expr *pExpr,            /* The IN, SELECT, or EXISTS operator */
  int rHasNullFlag,       /* Register that records whether NULLs exist in RHS */
  int isRowid             /* If true, LHS of IN operator is a rowid */
){
  int jmpIfDynamic = -1;                      /* One-time test address */
  int rReg = 0;                           /* Register storing resulting */
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( NEVER(v==0) ) return 0;
  sqlite3ExprCachePush(pParse);

  /* The evaluation of the IN/EXISTS/SELECT must be repeated every time it
  ** is encountered if any of the following is true:
  **
  **    *  The right-hand side is a correlated subquery
  **    *  The right-hand side is an expression list containing variables
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.

    );
    sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
  }
#endif

  switch( pExpr->op ){
    case TK_IN: {

      int addr;                   /* Address of OP_OpenEphemeral instruction */
      Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
      KeyInfo *pKeyInfo = 0;      /* Key information */
      int nVal;                   /* Size of vector pLeft */
      
      nVal = sqlite3ExprVectorSize(pLeft);
      assert( !isRowid || nVal==1 );

      /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
      ** expression it is handled the same way.  An ephemeral table is 
      ** filled with index keys representing the results from the 
      ** SELECT or the <exprlist>.
      **
      ** If the 'x' expression is a column value, or the SELECT...
      ** statement returns a column value, then the affinity of that
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, 
          pExpr->iTable, (isRowid?0:nVal));
      pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, nVal, 1);

      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
        Select *pSelect = pExpr->x.pSelect;

        ExprList *pEList = pSelect->pEList;

        assert( !isRowid );
        /* If the LHS and RHS of the IN operator do not match, that
        ** error will have been caught long before we reach this point. */
        if( ALWAYS(pEList->nExpr==nVal) ){
          SelectDest dest;
          int i;
          sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
          dest.zAffSdst = exprINAffinity(pParse, pExpr);
          assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
          pSelect->iLimit = 0;
          testcase( pSelect->selFlags & SF_Distinct );
          testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
          if( sqlite3Select(pParse, pSelect, &dest) ){
            sqlite3DbFree(pParse->db, dest.zAffSdst);
            sqlite3KeyInfoUnref(pKeyInfo);
            return 0;
          }

          sqlite3DbFree(pParse->db, dest.zAffSdst);
          assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
          assert( pEList!=0 );
          assert( pEList->nExpr>0 );
          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
          for(i=0; i<nVal; i++){
            Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
            pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
                pParse, p, pEList->a[i].pExpr
            );
          }
        }
      }else if( ALWAYS(pExpr->x.pList!=0) ){
        /* Case 2:     expr IN (exprlist)
        **
        ** For each expression, build an index key from the evaluation and
        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        char affinity;            /* Affinity of the LHS of the IN */
        int i;
        ExprList *pList = pExpr->x.pList;
        struct ExprList_item *pItem;
        int r1, r2, r3;

        affinity = sqlite3ExprAffinity(pLeft);
        if( !affinity ){
          affinity = SQLITE_AFF_BLOB;
        }
        if( pKeyInfo ){
          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
          pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
        }

      }
      break;
    }

    case TK_EXISTS:
    case TK_SELECT:
    default: {
      /* Case 3:    (SELECT ... FROM ...)
      **     or:    EXISTS(SELECT ... FROM ...)
      **
      ** For a SELECT, generate code to put the values for all columns of
      ** the first row into an array of registers and return the index of
      ** the first register.

      **
      ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)

      ** into a register and return that register number.
      **
      ** In both cases, the query is augmented with "LIMIT 1".  Any 
      ** preexisting limit is discarded in place of the new LIMIT 1.
      */
      Select *pSel;                         /* SELECT statement to encode */
      SelectDest dest;                      /* How to deal with SELECT result */
      int nReg;                             /* Registers to allocate */

      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );

      assert( ExprHasProperty(pExpr, EP_xIsSelect) );

      pSel = pExpr->x.pSelect;
      nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
      sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
      pParse->nMem += nReg;
      if( pExpr->op==TK_SELECT ){
        dest.eDest = SRT_Mem;
        dest.iSdst = dest.iSDParm;
        dest.nSdst = nReg;
        sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      sqlite3ExprDelete(pParse->db, pSel->pLimit);

    sqlite3VdbeJumpHere(v, jmpIfDynamic);
  }
  sqlite3ExprCachePop(pParse);

  return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Expr pIn is an IN(...) expression. This function checks that the 
** sub-select on the RHS of the IN() operator has the same number of 
** columns as the vector on the LHS. Or, if the RHS of the IN() is not 
** a sub-query, that the LHS is a vector of size 1.
*/
SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){
  int nVector = sqlite3ExprVectorSize(pIn->pLeft);
  if( (pIn->flags & EP_xIsSelect) ){
    if( nVector!=pIn->x.pSelect->pEList->nExpr ){
      sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);
      return 1;
    }
  }else if( nVector!=1 ){
    if( (pIn->pLeft->flags & EP_xIsSelect) ){
      sqlite3SubselectError(pParse, nVector, 1);
    }else{
      sqlite3ErrorMsg(pParse, "row value misused");
    }
    return 1;
  }
  return 0;
}
#endif

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code for an IN expression.
**
**      x IN (SELECT ...)
**      x IN (value, value, ...)
**
** The left-hand side (LHS) is a scalar or vector expression.  The 
** right-hand side (RHS) is an array of zero or more scalar values, or a
** subquery.  If the RHS is a subquery, the number of result columns must
** match the number of columns in the vector on the LHS.  If the RHS is
** a list of values, the LHS must be a scalar. 
**
** The IN operator is true if the LHS value is contained within the RHS.
** The result is false if the LHS is definitely not in the RHS.  The 
** result is NULL if the presence of the LHS in the RHS cannot be 
** determined due to NULLs.
**
** This routine generates code that jumps to destIfFalse if the LHS is not 
** contained within the RHS.  If due to NULLs we cannot determine if the LHS
** is contained in the RHS then jump to destIfNull.  If the LHS is contained
** within the RHS then fall through.
**
** See the separate in-operator.md documentation file in the canonical
** SQLite source tree for additional information.
*/
static void sqlite3ExprCodeIN(
  Parse *pParse,        /* Parsing and code generating context */
  Expr *pExpr,          /* The IN expression */
  int destIfFalse,      /* Jump here if LHS is not contained in the RHS */
  int destIfNull        /* Jump here if the results are unknown due to NULLs */
){
  int rRhsHasNull = 0;  /* Register that is true if RHS contains NULL values */

  int eType;            /* Type of the RHS */
  int rLhs;             /* Register(s) holding the LHS values */
  int rLhsOrig;         /* LHS values prior to reordering by aiMap[] */
  Vdbe *v;              /* Statement under construction */
  int *aiMap = 0;       /* Map from vector field to index column */
  char *zAff = 0;       /* Affinity string for comparisons */
  int nVector;          /* Size of vectors for this IN operator */
  int iDummy;           /* Dummy parameter to exprCodeVector() */
  Expr *pLeft;          /* The LHS of the IN operator */
  int i;                /* loop counter */
  int destStep2;        /* Where to jump when NULLs seen in step 2 */
  int destStep6 = 0;    /* Start of code for Step 6 */
  int addrTruthOp;      /* Address of opcode that determines the IN is true */
  int destNotNull;      /* Jump here if a comparison is not true in step 6 */
  int addrTop;          /* Top of the step-6 loop */ 

  pLeft = pExpr->pLeft;
  if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
  zAff = exprINAffinity(pParse, pExpr);
  nVector = sqlite3ExprVectorSize(pExpr->pLeft);
  aiMap = (int*)sqlite3DbMallocZero(
      pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
  );
  if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;

  /* Attempt to compute the RHS. After this step, if anything other than
  ** IN_INDEX_NOOP is returned, the table opened ith cursor pExpr->iTable 
  ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,

  ** the RHS has not yet been coded.  */
  v = pParse->pVdbe;
  assert( v!=0 );       /* OOM detected prior to this routine */
  VdbeNoopComment((v, "begin IN expr"));
  eType = sqlite3FindInIndex(pParse, pExpr,
                             IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
                             destIfFalse==destIfNull ? 0 : &rRhsHasNull, aiMap);

  assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
       || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC 
  );
#ifdef SQLITE_DEBUG
  /* Confirm that aiMap[] contains nVector integer values between 0 and
  ** nVector-1. */

  for(i=0; i<nVector; i++){
    int j, cnt;
    for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;
    assert( cnt==1 );
  }
#endif

  /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a 
  ** vector, then it is stored in an array of nVector registers starting 
  ** at r1.
  **
  ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
  ** so that the fields are in the same order as an existing index.   The
  ** aiMap[] array contains a mapping from the original LHS field order to
  ** the field order that matches the RHS index.
  */
  sqlite3ExprCachePush(pParse);
  rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);
  for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */
  if( i==nVector ){
    /* LHS fields are not reordered */
    rLhs = rLhsOrig;
  }else{
    /* Need to reorder the LHS fields according to aiMap */
    rLhs = sqlite3GetTempRange(pParse, nVector);
    for(i=0; i<nVector; i++){
      sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);
    }
  }

  /* If sqlite3FindInIndex() did not find or create an index that is
  ** suitable for evaluating the IN operator, then evaluate using a
  ** sequence of comparisons.
  **
  ** This is step (1) in the in-operator.md optimized algorithm.
  */
  if( eType==IN_INDEX_NOOP ){
    ExprList *pList = pExpr->x.pList;
    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    int labelOk = sqlite3VdbeMakeLabel(v);
    int r2, regToFree;
    int regCkNull = 0;
    int ii;
    assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
    if( destIfNull!=destIfFalse ){
      regCkNull = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);
    }
    for(ii=0; ii<pList->nExpr; ii++){
      r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);
      if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){
        sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);
      }
      if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){
        sqlite3VdbeAddOp4(v, OP_Eq, rLhs, labelOk, r2,
                          (void*)pColl, P4_COLLSEQ);
        VdbeCoverageIf(v, ii<pList->nExpr-1);
        VdbeCoverageIf(v, ii==pList->nExpr-1);
        sqlite3VdbeChangeP5(v, zAff[0]);
      }else{
        assert( destIfNull==destIfFalse );
        sqlite3VdbeAddOp4(v, OP_Ne, rLhs, destIfFalse, r2,
                          (void*)pColl, P4_COLLSEQ); VdbeCoverage(v);
        sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
      }
      sqlite3ReleaseTempReg(pParse, regToFree);
    }
    if( regCkNull ){
      sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);
      sqlite3VdbeGoto(v, destIfFalse);
    }
    sqlite3VdbeResolveLabel(v, labelOk);
    sqlite3ReleaseTempReg(pParse, regCkNull);
    goto sqlite3ExprCodeIN_finished;
  }

  /* Step 2: Check to see if the LHS contains any NULL columns.  If the
  ** LHS does contain NULLs then the result must be either FALSE or NULL.
  ** We will then skip the binary search of the RHS.
  */

  if( destIfNull==destIfFalse ){


    destStep2 = destIfFalse;
  }else{
    destStep2 = destStep6 = sqlite3VdbeMakeLabel(v);
  }
  for(i=0; i<nVector; i++){
    Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
    if( sqlite3ExprCanBeNull(p) ){
      sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
      VdbeCoverage(v);


    }
  }

  /* Step 3.  The LHS is now known to be non-NULL.  Do the binary search
  ** of the RHS using the LHS as a probe.  If found, the result is
  ** true.
  */
  if( eType==IN_INDEX_ROWID ){
    /* In this case, the RHS is the ROWID of table b-tree and so we also
    ** know that the RHS is non-NULL.  Hence, we combine steps 3 and 4
    ** into a single opcode. */
    sqlite3VdbeAddOp3(v, OP_SeekRowid, pExpr->iTable, destIfFalse, rLhs);
    VdbeCoverage(v);
    addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto);  /* Return True */
  }else{
    sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
    if( destIfFalse==destIfNull ){
      /* Combine Step 3 and Step 5 into a single opcode */
      sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse,
                           rLhs, nVector); VdbeCoverage(v);
      goto sqlite3ExprCodeIN_finished;
    }
    /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
    addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0,
                                      rLhs, nVector); VdbeCoverage(v);
  }

  /* Step 4.  If the RHS is known to be non-NULL and we did not find
  ** an match on the search above, then the result must be FALSE.
  */
  if( rRhsHasNull && nVector==1 ){
    sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);
    VdbeCoverage(v);
  }

  /* Step 5.  If we do not care about the difference between NULL and

  ** FALSE, then just return false. 


  */
  if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);




  /* Step 6: Loop through rows of the RHS.  Compare each row to the LHS.
  ** If any comparison is NULL, then the result is NULL.  If all
  ** comparisons are FALSE then the final result is FALSE.
  **
  ** For a scalar LHS, it is sufficient to check just the first row
  ** of the RHS.
  */
  if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
  addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
  VdbeCoverage(v);
  if( nVector>1 ){
    destNotNull = sqlite3VdbeMakeLabel(v);
  }else{
    /* For nVector==1, combine steps 6 and 7 by immediately returning
    ** FALSE if the first comparison is not NULL */
    destNotNull = destIfFalse;
  }
  for(i=0; i<nVector; i++){
    Expr *p;

    CollSeq *pColl;
    int r3 = sqlite3GetTempReg(pParse);
    p = sqlite3VectorFieldSubexpr(pLeft, i);
    pColl = sqlite3ExprCollSeq(pParse, p);
    sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, i, r3);


    sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
                      (void*)pColl, P4_COLLSEQ);
    VdbeCoverage(v);
    sqlite3ReleaseTempReg(pParse, r3);
  }
  sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
  if( nVector>1 ){
    sqlite3VdbeResolveLabel(v, destNotNull);
    sqlite3VdbeAddOp2(v, OP_Next, pExpr->iTable, addrTop+1);
    VdbeCoverage(v);

    /* Step 7:  If we reach this point, we know that the result must
    ** be false. */
    sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
  }

  /* Jumps here in order to return true. */
  sqlite3VdbeJumpHere(v, addrTruthOp);

sqlite3ExprCodeIN_finished:
  if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);
  sqlite3ExprCachePop(pParse);
  VdbeComment((v, "end IN expr"));
sqlite3ExprCodeIN_oom_error:
  sqlite3DbFree(pParse->db, aiMap);
  sqlite3DbFree(pParse->db, zAff);
}
#endif /* SQLITE_OMIT_SUBQUERY */

#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** Generate an instruction that will put the floating point
** value described by z[0..n-1] into register iMem.

  }
  return 0;
}
#endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */


/*
** Convert a scalar expression node to a TK_REGISTER referencing
** register iReg.  The caller must ensure that iReg already contains
** the correct value for the expression.
*/
static void exprToRegister(Expr *p, int iReg){
  p->op2 = p->op;
  p->op = TK_REGISTER;
  p->iTable = iReg;
  ExprClearProperty(p, EP_Skip);
}

/*
** Evaluate an expression (either a vector or a scalar expression) and store
** the result in continguous temporary registers.  Return the index of
** the first register used to store the result.
**
** If the returned result register is a temporary scalar, then also write
** that register number into *piFreeable.  If the returned result register
** is not a temporary or if the expression is a vector set *piFreeable
** to 0.
*/
static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){
  int iResult;
  int nResult = sqlite3ExprVectorSize(p);
  if( nResult==1 ){
    iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
  }else{
    *piFreeable = 0;
    if( p->op==TK_SELECT ){
      iResult = sqlite3CodeSubselect(pParse, p, 0, 0);
    }else{
      int i;
      iResult = pParse->nMem+1;
      pParse->nMem += nResult;
      for(i=0; i<nResult; i++){
        sqlite3ExprCode(pParse, p->x.pList->a[i].pExpr, i+iResult);
      }
    }
  }
  return iResult;
}


/*
** Generate code into the current Vdbe to evaluate the given
** expression.  Attempt to store the results in register "target".
** Return the register where results are stored.
**
** With this routine, there is no guarantee that results will
** be stored in target.  The result might be stored in some other
** register if it is convenient to do so.  The calling function
** must check the return code and move the results to the desired
** register.
*/
SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
  Vdbe *v = pParse->pVdbe;  /* The VM under construction */
  int op;                   /* The opcode being coded */
  int inReg = target;       /* Results stored in register inReg */
  int regFree1 = 0;         /* If non-zero free this temporary register */
  int regFree2 = 0;         /* If non-zero free this temporary register */
  int r1, r2;               /* Various register numbers */
  sqlite3 *db = pParse->db; /* The database connection */
  Expr tempX;               /* Temporary expression node */
  int p5 = 0;

  assert( target>0 && target<=pParse->nMem );
  if( v==0 ){
    assert( pParse->db->mallocFailed );
    return 0;
  }

      sqlite3VdbeAddOp2(v, OP_Cast, target,
                        sqlite3AffinityType(pExpr->u.zToken, 0));
      testcase( usedAsColumnCache(pParse, inReg, inReg) );
      sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
      break;
    }
#endif /* SQLITE_OMIT_CAST */
    case TK_IS:
    case TK_ISNOT:
      op = (op==TK_IS) ? TK_EQ : TK_NE;
      p5 = SQLITE_NULLEQ;
      /* fall-through */
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      Expr *pLeft = pExpr->pLeft;
      if( sqlite3ExprIsVector(pLeft) ){
        codeVectorCompare(pParse, pExpr, target, op, p5);
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
        codeCompare(pParse, pLeft, pExpr->pRight, op,
            r1, r2, inReg, SQLITE_STOREP2 | p5);
        assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
        assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
        assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
        assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);
        assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);
        assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);
        testcase( regFree1==0 );
        testcase( regFree2==0 );

      }













      break;
    }
    case TK_AND:
    case TK_OR:
    case TK_PLUS:
    case TK_STAR:
    case TK_MINUS:

        sqlite3ReleaseTempRange(pParse, r1, nFarg);
      }
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      int nCol;
      testcase( op==TK_EXISTS );
      testcase( op==TK_SELECT );
      if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
        sqlite3SubselectError(pParse, nCol, 1);
      }else{
        inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
      }
      break;
    }
    case TK_SELECT_COLUMN: {
      if( pExpr->pLeft->iTable==0 ){
        pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft, 0, 0);
      }
      inReg = pExpr->pLeft->iTable + pExpr->iColumn;
      break;
    }
    case TK_IN: {
      int destIfFalse = sqlite3VdbeMakeLabel(v);
      int destIfNull = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp2(v, OP_Null, 0, target);
      sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

    **    x>=y AND x<=z
    **
    ** X is stored in pExpr->pLeft.
    ** Y is stored in pExpr->pList->a[0].pExpr.
    ** Z is stored in pExpr->pList->a[1].pExpr.
    */
    case TK_BETWEEN: {



      exprCodeBetween(pParse, pExpr, target, 0, 0);


















      break;
    }
    case TK_SPAN:
    case TK_COLLATE: 
    case TK_UPLUS: {
      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
      break;

      ){
        sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
      }
#endif
      break;
    }

    case TK_VECTOR: {
      sqlite3ErrorMsg(pParse, "row value misused");
      break;
    }

    /*
    ** Form A:
    **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
    **
    ** Form B:
    **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      if( (pX = pExpr->pLeft)!=0 ){
        tempX = *pX;
        testcase( pX->op==TK_COLUMN );
        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));
        testcase( regFree1==0 );
        memset(&opCompare, 0, sizeof(opCompare));
        opCompare.op = TK_EQ;
        opCompare.pLeft = &tempX;
        pTest = &opCompare;
        /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
        ** The value in regFree1 might get SCopy-ed into the file result.
        ** So make sure that the regFree1 register is not reused for other
        ** purposes and possibly overwritten.  */

**
** The above is equivalent to 
**
**    x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elimination of x.
**
** The xJumpIf parameter determines details:
**
**    NULL:                   Store the boolean result in reg[dest]
**    sqlite3ExprIfTrue:      Jump to dest if true
**    sqlite3ExprIfFalse:     Jump to dest if false
**
** The jumpIfNull parameter is ignored if xJumpIf is NULL.
*/
static void exprCodeBetween(
  Parse *pParse,    /* Parsing and code generating context */
  Expr *pExpr,      /* The BETWEEN expression */
  int dest,         /* Jump destination or storage location */
  void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
  int jumpIfNull    /* Take the jump if the BETWEEN is NULL */
){
 Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
  Expr compLeft;    /* The  x>=y  term */
  Expr compRight;   /* The  x<=z  term */
  Expr exprX;       /* The  x  subexpression */
  int regFree1 = 0; /* Temporary use register */


  memset(&compLeft, 0, sizeof(Expr));
  memset(&compRight, 0, sizeof(Expr));
  memset(&exprAnd, 0, sizeof(Expr));

  assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
  exprX = *pExpr->pLeft;
  exprAnd.op = TK_AND;
  exprAnd.pLeft = &compLeft;
  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;
  compRight.pLeft = &exprX;
  compRight.pRight = pExpr->x.pList->a[1].pExpr;
  exprToRegister(&exprX, exprCodeVector(pParse, &exprX, &regFree1));
  if( xJump ){
    xJump(pParse, &exprAnd, dest, jumpIfNull);
  }else{
    exprX.flags |= EP_FromJoin;
    sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
  }
  sqlite3ReleaseTempReg(pParse, regFree1);

  /* Ensure adequate test coverage */
  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1==0 );
  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1!=0 );
  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1==0 );
  testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1!=0 );
  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );
  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );
  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );
  testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );
  testcase( xJump==0 );
}

/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
**

      /* Fall thru */
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
      testcase( jumpIfNull==0 );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                  r1, r2, dest, jumpIfNull);
      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

      VdbeCoverageIf(v, op==TK_ISNULL);
      VdbeCoverageIf(v, op==TK_NOTNULL);
      testcase( regFree1==0 );
      break;
    }
    case TK_BETWEEN: {
      testcase( jumpIfNull==0 );
      exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      int destIfFalse = sqlite3VdbeMakeLabel(v);
      int destIfNull = jumpIfNull ? dest : destIfFalse;
      sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
      sqlite3VdbeGoto(v, dest);
      sqlite3VdbeResolveLabel(v, destIfFalse);
      break;
    }
#endif
    default: {
    default_expr:
      if( exprAlwaysTrue(pExpr) ){
        sqlite3VdbeGoto(v, dest);
      }else if( exprAlwaysFalse(pExpr) ){
        /* No-op */
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
        sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);

      /* Fall thru */
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;
      testcase( jumpIfNull==0 );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                  r1, r2, dest, jumpIfNull);
      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

      testcase( op==TK_ISNULL );   VdbeCoverageIf(v, op==TK_ISNULL);
      testcase( op==TK_NOTNULL );  VdbeCoverageIf(v, op==TK_NOTNULL);
      testcase( regFree1==0 );
      break;
    }
    case TK_BETWEEN: {
      testcase( jumpIfNull==0 );
      exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      if( jumpIfNull ){
        sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
      }else{
        int destIfNull = sqlite3VdbeMakeLabel(v);
        sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
        sqlite3VdbeResolveLabel(v, destIfNull);
      }
      break;
    }
#endif
    default: {
    default_expr: 
      if( exprAlwaysFalse(pExpr) ){
        sqlite3VdbeGoto(v, dest);
      }else if( exprAlwaysTrue(pExpr) ){
        /* no-op */
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);
        sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);

      }
    }
    pParse->aTempReg[pParse->nTempReg++] = iReg;
  }
}

/*
** Allocate or deallocate a block of nReg consecutive registers.
*/
SQLITE_PRIVATE int sqlite3GetTempRange(Parse *pParse, int nReg){
  int i, n;
  if( nReg==1 ) return sqlite3GetTempReg(pParse);
  i = pParse->iRangeReg;
  n = pParse->nRangeReg;
  if( nReg<=n ){
    assert( !usedAsColumnCache(pParse, i, i+n-1) );
    pParse->iRangeReg += nReg;
    pParse->nRangeReg -= nReg;
  }else{
    i = pParse->nMem+1;
    pParse->nMem += nReg;
  }
  return i;
}
SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
  if( nReg==1 ){
    sqlite3ReleaseTempReg(pParse, iReg);
    return;
  }
  sqlite3ExprCacheRemove(pParse, iReg, nReg);
  if( nReg>pParse->nRangeReg ){
    pParse->nRangeReg = nReg;
    pParse->iRangeReg = iReg;
  }
}

    while( sqlite3VdbeDeletePriorOpcode(v, OP_Close) ){}
    sqlite3VdbeAddOp0(v, OP_Halt);

#if SQLITE_USER_AUTHENTICATION
    if( pParse->nTableLock>0 && db->init.busy==0 ){
      sqlite3UserAuthInit(db);
      if( db->auth.authLevel<UAUTH_User ){

        sqlite3ErrorMsg(pParse, "user not authenticated");
        pParse->rc = SQLITE_AUTH_USER;
        return;
      }
    }
#endif

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are

  }else{
    sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
  }
  if( piIdxCur ) *piIdxCur = iBase;
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    int iIdxCur = iBase++;
    assert( pIdx->pSchema==pTab->pSchema );
    if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
      if( piDataCur ) *piDataCur = iIdxCur;
      p5 = 0;
    }
    if( aToOpen==0 || aToOpen[i+1] ){
      sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
      sqlite3VdbeSetP4KeyInfo(pParse, pIdx);





      sqlite3VdbeChangeP5(v, p5);
      VdbeComment((v, "%s", pIdx->zName));
    }
  }
  if( iBase>pParse->nTab ) pParse->nTab = iBase;
  return i;
}

/*
** Initialize a SelectDest structure.
*/
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
  pDest->eDest = (u8)eDest;
  pDest->iSDParm = iParm;
  pDest->zAffSdst = 0;
  pDest->iSdst = 0;
  pDest->nSdst = 0;
}


/*
** Allocate a new Select structure and return a pointer to that

  r1 = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
  sqlite3ReleaseTempReg(pParse, r1);
}

























/*
** This routine generates the code for the inside of the inner loop
** of a SELECT.
**
** If srcTab is negative, then the pEList expressions
** are evaluated in order to get the data for this row.  If srcTab is
** zero or more, then data is pulled from srcTab and pEList is used only 

#ifndef SQLITE_OMIT_SUBQUERY
    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
    ** item into the set table with bogus data.
    */
    case SRT_Set: {



      if( pSort ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        pushOntoSorter(
            pParse, pSort, p, regResult, regResult, nResultCol, nPrefixReg);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol );
        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, nResultCol, 
            r1, pDest->zAffSdst, nResultCol);
        sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      break;
    }

    /* If any row exist in the result set, record that fact and abort.
    */
    case SRT_Exists: {
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell or array of 
    ** memory cells and break out of the scan loop.
    */
    case SRT_Mem: {
      assert( nResultCol==pDest->nSdst );
      if( pSort ){
        pushOntoSorter(
            pParse, pSort, p, regResult, regResult, nResultCol, nPrefixReg);
      }else{
        assert( regResult==iParm );
        /* The LIMIT clause will jump out of the loop for us */
      }
      break;
    }
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */

  assert( addrBreak<0 );
  if( pSort->labelBkOut ){
    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
    sqlite3VdbeGoto(v, addrBreak);
    sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
  }
  iTab = pSort->iECursor;
  if( eDest==SRT_Output || eDest==SRT_Coroutine || eDest==SRT_Mem ){
    regRowid = 0;
    regRow = pDest->iSdst;
    nSortData = nColumn;
  }else{
    regRowid = sqlite3GetTempReg(pParse);
    regRow = sqlite3GetTempRange(pParse, nColumn);
    nSortData = nColumn;
  }
  nKey = pOrderBy->nExpr - pSort->nOBSat;
  if( pSort->sortFlags & SORTFLAG_UseSorter ){
    int regSortOut = ++pParse->nMem;
    iSortTab = pParse->nTab++;
    if( pSort->labelBkOut ){
      addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);

      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      assert( nColumn==sqlite3Strlen30(pDest->zAffSdst) );
      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, nColumn, regRowid,
                        pDest->zAffSdst, nColumn);
      sqlite3ExprCacheAffinityChange(pParse, regRow, nColumn);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
      break;
    }
    case SRT_Mem: {


      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    default: {
      assert( eDest==SRT_Output || eDest==SRT_Coroutine ); 
      testcase( eDest==SRT_Output );
      testcase( eDest==SRT_Coroutine );
      if( eDest==SRT_Output ){
        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
        sqlite3ExprCacheAffinityChange(pParse, pDest->iSdst, nColumn);
      }else{
        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
      }
      break;
    }
  }
  if( regRowid ){
    if( eDest==SRT_Set ){
      sqlite3ReleaseTempRange(pParse, regRow, nColumn);
    }else{
      sqlite3ReleaseTempReg(pParse, regRow);
    }
    sqlite3ReleaseTempReg(pParse, regRowid);
  }
  /* The bottom of the loop
  */
  sqlite3VdbeResolveLabel(v, addrContinue);
  if( pSort->sortFlags & SORTFLAG_UseSorter ){
    sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);

/*
** Get a VDBE for the given parser context.  Create a new one if necessary.
** If an error occurs, return NULL and leave a message in pParse.
*/
static SQLITE_NOINLINE Vdbe *allocVdbe(Parse *pParse){
  Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(pParse);
  if( v ) sqlite3VdbeAddOp2(v, OP_Init, 0, 1);
  if( pParse->pToplevel==0
   && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
  ){
    pParse->okConstFactor = 1;
  }
  return v;
}

      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
      sqlite3ReleaseTempReg(pParse, r2);
      sqlite3ReleaseTempReg(pParse, r1);
      break;
    }

#ifndef SQLITE_OMIT_SUBQUERY
    /* If we are creating a set for an "expr IN (SELECT ...)".


    */
    case SRT_Set: {
      int r1;
      testcase( pIn->nSdst>1 );


      r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, 
          r1, pDest->zAffSdst, pIn->nSdst);
      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iSDParm, r1);
      sqlite3ReleaseTempReg(pParse, r1);
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out

  assert( p->pEList!=0 );
  isAgg = (p->selFlags & SF_Aggregate)!=0;
#if SELECTTRACE_ENABLED
  if( sqlite3SelectTrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }










#endif

  /* Try to flatten subqueries in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];

  sqlite3VtabLock(pVTab);
}

/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb. 
**
** If an error occurs, *pzErr is set to point to an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
*/
SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
  int rc = SQLITE_OK;
  Table *pTab;
  Module *pMod;

  u8 iSortIdx;          /* Sorting index number.  0==None */
  LogEst rSetup;        /* One-time setup cost (ex: create transient index) */
  LogEst rRun;          /* Cost of running each loop */
  LogEst nOut;          /* Estimated number of output rows */
  union {
    struct {               /* Information for internal btree tables */
      u16 nEq;               /* Number of equality constraints */
      u16 nBtm;              /* Size of BTM vector */
      u16 nTop;              /* Size of TOP vector */
      Index *pIndex;         /* Index used, or NULL */
    } btree;
    struct {               /* Information for virtual tables */
      int idxNum;            /* Index number */
      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
      i8 isOrdered;          /* True if satisfies ORDER BY */
      u16 omitMask;          /* Terms that may be omitted */

** in prereqRight and prereqAll.  The default is 64 bits, hence SQLite
** is only able to process joins with 64 or fewer tables.
*/
struct WhereTerm {
  Expr *pExpr;            /* Pointer to the subexpression that is this term */
  int iParent;            /* Disable pWC->a[iParent] when this term disabled */
  int leftCursor;         /* Cursor number of X in "X <op> <expr>" */
  int iField;             /* Field in (?,?,?) IN (SELECT...) vector */
  union {
    int leftColumn;         /* Column number of X in "X <op> <expr>" */
    WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
    WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
  } u;
  LogEst truthProb;       /* Probability of truth for this expression */
  u16 eOperator;          /* A WO_xx value describing <op> */

#define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/
#define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */

/************** End of whereInt.h ********************************************/
/************** Continuing where we left off in wherecode.c ******************/

#ifndef SQLITE_OMIT_EXPLAIN

/*
** Return the name of the i-th column of the pIdx index.
*/
static const char *explainIndexColumnName(Index *pIdx, int i){
  i = pIdx->aiColumn[i];
  if( i==XN_EXPR ) return "<expr>";
  if( i==XN_ROWID ) return "rowid";
  return pIdx->pTable->aCol[i].zName;
}

/*
** This routine is a helper for explainIndexRange() below
**
** pStr holds the text of an expression that we are building up one term
** at a time.  This routine adds a new term to the end of the expression.
** Terms are separated by AND so add the "AND" text for second and subsequent
** terms only.
*/
static void explainAppendTerm(
  StrAccum *pStr,             /* The text expression being built */
  Index *pIdx,                /* Index to read column names from */
  int nTerm,                  /* Number of terms */
  int iTerm,                  /* Zero-based index of first term. */
  int bAnd,                   /* Non-zero to append " AND " */
  const char *zOp             /* Name of the operator */
){
  int i;

  assert( nTerm>=1 );
  if( bAnd ) sqlite3StrAccumAppend(pStr, " AND ", 5);

  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, "(", 1);
  for(i=0; i<nTerm; i++){
    if( i ) sqlite3StrAccumAppend(pStr, ",", 1);
    sqlite3StrAccumAppendAll(pStr, explainIndexColumnName(pIdx, iTerm+i));
  }
  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, ")", 1);

  sqlite3StrAccumAppend(pStr, zOp, 1);

  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, "(", 1);
  for(i=0; i<nTerm; i++){
    if( i ) sqlite3StrAccumAppend(pStr, ",", 1);
    sqlite3StrAccumAppend(pStr, "?", 1);
  }





  if( nTerm>1 ) sqlite3StrAccumAppend(pStr, ")", 1);


}

/*
** Argument pLevel describes a strategy for scanning table pTab. This 
** function appends text to pStr that describes the subset of table
** rows scanned by the strategy in the form of an SQL expression.
**

    const char *z = explainIndexColumnName(pIndex, i);
    if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
    sqlite3XPrintf(pStr, i>=nSkip ? "%s=?" : "ANY(%s)", z);
  }

  j = i;
  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){

    explainAppendTerm(pStr, pIndex, pLoop->u.btree.nBtm, j, i, ">");
    i = 1;
  }
  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){

    explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");
  }
  sqlite3StrAccumAppend(pStr, ")", 1);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was

** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
** The TERM_LIKECOND marking indicates that the term should be coded inside
** a conditional such that is only evaluated on the second pass of a
** LIKE-optimization loop, when scanning BLOBs instead of strings.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
  int nLoop = 0;
  while( ALWAYS(pTerm!=0)
      && (pTerm->wtFlags & TERM_CODED)==0
      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
      && (pLevel->notReady & pTerm->prereqAll)==0
  ){
    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
      pTerm->wtFlags |= TERM_LIKECOND;
    }else{

  /* Code the OP_Affinity opcode if there is anything left to do. */
  if( n>0 ){
    sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);
    sqlite3ExprCacheAffinityChange(pParse, base, n);
  }
}

/*
** Expression pRight, which is the RHS of a comparison operation, is 
** either a vector of n elements or, if n==1, a scalar expression.
** Before the comparison operation, affinity zAff is to be applied
** to the pRight values. This function modifies characters within the
** affinity string to SQLITE_AFF_BLOB if either:
**
**   * the comparison will be performed with no affinity, or
**   * the affinity change in zAff is guaranteed not to change the value.
*/
static void updateRangeAffinityStr(
  Parse *pParse,                  /* Parse context */
  Expr *pRight,                   /* RHS of comparison */
  int n,                          /* Number of vector elements in comparison */
  char *zAff                      /* Affinity string to modify */
){
  int i;
  for(i=0; i<n; i++){
    Expr *p = sqlite3VectorFieldSubexpr(pRight, i);
    if( sqlite3CompareAffinity(p, zAff[i])==SQLITE_AFF_BLOB
     || sqlite3ExprNeedsNoAffinityChange(p, zAff[i])
    ){
      zAff[i] = SQLITE_AFF_BLOB;
    }
  }
}

/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
** coded.
**
** The current value for the constraint is left in a register, the index
** of which is returned.  An attempt is made store the result in iTarget but
** this is only guaranteed for TK_ISNULL and TK_IN constraints.  If the
** constraint is a TK_EQ or TK_IS, then the current value might be left in
** some other register and it is the caller's responsibility to compensate.
**
** For a constraint of the form X=expr, the expression is evaluated in
** straight-line code.  For constraints of the form X IN (...)
** this routine sets up a loop that will iterate over all values of X.
*/
static int codeEqualityTerm(
  Parse *pParse,      /* The parsing context */
  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
  int iEq,            /* Index of the equality term within this level */
  int bRev,           /* True for reverse-order IN operations */
  int iTarget         /* Attempt to leave results in this register */
){
  Expr *pX = pTerm->pExpr;
  Vdbe *v = pParse->pVdbe;
  int iReg;                  /* Register holding results */

  assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );
  assert( iTarget>0 );
  if( pX->op==TK_EQ || pX->op==TK_IS ){
    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
  }else if( pX->op==TK_ISNULL ){
    iReg = iTarget;
    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
#ifndef SQLITE_OMIT_SUBQUERY
  }else{
    int eType = IN_INDEX_NOOP;
    int iTab;
    struct InLoop *pIn;
    WhereLoop *pLoop = pLevel->pWLoop;
    int i;
    int nEq = 0;
    int *aiMap = 0;

    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
      && pLoop->u.btree.pIndex!=0
      && pLoop->u.btree.pIndex->aSortOrder[iEq]
    ){
      testcase( iEq==0 );
      testcase( bRev );
      bRev = !bRev;
    }
    assert( pX->op==TK_IN );
    iReg = iTarget;

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

    if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){
      eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0);
    }else{
      Select *pSelect = pX->x.pSelect;
      sqlite3 *db = pParse->db;
      ExprList *pOrigRhs = pSelect->pEList;
      ExprList *pOrigLhs = pX->pLeft->x.pList;
      ExprList *pRhs = 0;         /* New Select.pEList for RHS */
      ExprList *pLhs = 0;         /* New pX->pLeft vector */

      for(i=iEq;i<pLoop->nLTerm; i++){
        if( pLoop->aLTerm[i]->pExpr==pX ){
          int iField = pLoop->aLTerm[i]->iField - 1;
          Expr *pNewRhs = sqlite3ExprDup(db, pOrigRhs->a[iField].pExpr, 0);
          Expr *pNewLhs = sqlite3ExprDup(db, pOrigLhs->a[iField].pExpr, 0);

          pRhs = sqlite3ExprListAppend(pParse, pRhs, pNewRhs);
          pLhs = sqlite3ExprListAppend(pParse, pLhs, pNewLhs);
        }
      }
      if( !db->mallocFailed ){
        Expr *pLeft = pX->pLeft;

        if( pSelect->pOrderBy ){
          /* If the SELECT statement has an ORDER BY clause, zero the 
          ** iOrderByCol variables. These are set to non-zero when an 
          ** ORDER BY term exactly matches one of the terms of the 
          ** result-set. Since the result-set of the SELECT statement may
          ** have been modified or reordered, these variables are no longer 
          ** set correctly.  Since setting them is just an optimization, 
          ** it's easiest just to zero them here.  */
          ExprList *pOrderBy = pSelect->pOrderBy;
          for(i=0; i<pOrderBy->nExpr; i++){
            pOrderBy->a[i].u.x.iOrderByCol = 0;
          }
        }

        /* Take care here not to generate a TK_VECTOR containing only a
        ** single value. Since the parser never creates such a vector, some
        ** of the subroutines do not handle this case.  */
        if( pLhs->nExpr==1 ){
          pX->pLeft = pLhs->a[0].pExpr;
        }else{
          pLeft->x.pList = pLhs;
          aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int) * nEq);
          testcase( aiMap==0 );
        }
        pSelect->pEList = pRhs;
        eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap);
        testcase( aiMap!=0 && aiMap[0]!=0 );
        pSelect->pEList = pOrigRhs;
        pLeft->x.pList = pOrigLhs;
        pX->pLeft = pLeft;
      }
      sqlite3ExprListDelete(pParse->db, pLhs);
      sqlite3ExprListDelete(pParse->db, pRhs);
    }

    if( eType==IN_INDEX_INDEX_DESC ){
      testcase( bRev );
      bRev = !bRev;
    }
    iTab = pX->iTable;
    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
    VdbeCoverageIf(v, bRev);
    VdbeCoverageIf(v, !bRev);
    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );

    pLoop->wsFlags |= WHERE_IN_ABLE;
    if( pLevel->u.in.nIn==0 ){
      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
    }

    i = pLevel->u.in.nIn;
    pLevel->u.in.nIn += nEq;
    pLevel->u.in.aInLoop =
       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
    pIn = pLevel->u.in.aInLoop;
    if( pIn ){
      int iMap = 0;               /* Index in aiMap[] */
      pIn += i;
      for(i=iEq;i<pLoop->nLTerm; i++){
        int iOut = iReg;
        if( pLoop->aLTerm[i]->pExpr==pX ){
          if( eType==IN_INDEX_ROWID ){
            assert( nEq==1 && i==iEq );
            pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
          }else{
            int iCol = aiMap ? aiMap[iMap++] : 0;
            iOut = iReg + i - iEq;
            pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);
          }
          sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);
          if( i==iEq ){
            pIn->iCur = iTab;
            pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;

          }else{
            pIn->eEndLoopOp = OP_Noop;
          }
          pIn++;
        }
      }
    }else{
      pLevel->u.in.nIn = 0;
    }
    sqlite3DbFree(pParse->db, aiMap);
#endif
  }
  disableTerm(pLevel, pTerm);
  return iReg;
}

/*

      if( nReg==1 ){
        sqlite3ReleaseTempReg(pParse, regBase);
        regBase = r1;
      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
      }
    }
    if( pTerm->eOperator & WO_IN ){
      if( pTerm->pExpr->flags & EP_xIsSelect ){
        /* No affinity ever needs to be (or should be) applied to a value
        ** from the RHS of an "? IN (SELECT ...)" expression. The 
        ** sqlite3FindInIndex() routine has already ensured that the 
        ** affinity of the comparison has been applied to the value.  */
        if( zAff ) zAff[j] = SQLITE_AFF_BLOB;
      }
    }else if( (pTerm->eOperator & WO_ISNULL)==0 ){
      Expr *pRight = pTerm->pExpr->pRight;
      if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
        VdbeCoverage(v);
      }
      if( zAff ){
        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){

        assert( pIdx->aiColumn[i]<pTab->nCol );
        if( pIdx->aiColumn[i]>=0 ) ai[pIdx->aiColumn[i]+1] = i+1;
      }
      sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
    }
  }
}

/*
** If the expression passed as the second argument is a vector, generate
** code to write the first nReg elements of the vector into an array
** of registers starting with iReg.
**
** If the expression is not a vector, then nReg must be passed 1. In
** this case, generate code to evaluate the expression and leave the
** result in register iReg.
*/
static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){
  assert( nReg>0 );
  if( sqlite3ExprIsVector(p) ){
#ifndef SQLITE_OMIT_SUBQUERY
    if( (p->flags & EP_xIsSelect) ){
      Vdbe *v = pParse->pVdbe;
      int iSelect = sqlite3CodeSubselect(pParse, p, 0, 0);
      sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1);
    }else
#endif
    {
      int i;
      ExprList *pList = p->x.pList;
      assert( nReg<=pList->nExpr );
      for(i=0; i<nReg; i++){
        sqlite3ExprCode(pParse, pList->a[i].pExpr, iReg+i);
      }
    }
  }else{
    assert( nReg==1 );
    sqlite3ExprCode(pParse, p, iReg);
  }
}

/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */

      int iTarget = iReg+j+2;
      pTerm = pLoop->aLTerm[j];
      if( NEVER(pTerm==0) ) continue;
      if( pTerm->eOperator & WO_IN ){
        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
        addrNotFound = pLevel->addrNxt;
      }else{
        Expr *pRight = pTerm->pExpr->pRight;
        codeExprOrVector(pParse, pRight, iTarget, 1);
      }
    }
    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
                      pLoop->u.vtab.idxStr,
                      pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);

      pStart = pEnd;
      pEnd = pTerm;
    }
    codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
    if( pStart ){
      Expr *pX;             /* The expression that defines the start bound */
      int r1, rTemp;        /* Registers for holding the start boundary */
      int op;               /* Cursor seek operation */

      /* The following constant maps TK_xx codes into corresponding 
      ** seek opcodes.  It depends on a particular ordering of TK_xx
      */
      const u8 aMoveOp[] = {
           /* TK_GT */  OP_SeekGT,
           /* TK_LE */  OP_SeekLE,
           /* TK_LT */  OP_SeekLT,
           /* TK_GE */  OP_SeekGE
      };
      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */

      assert( (pStart->wtFlags & TERM_VNULL)==0 );
      testcase( pStart->wtFlags & TERM_VIRTUAL );
      pX = pStart->pExpr;
      assert( pX!=0 );
      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
      if( sqlite3ExprIsVector(pX->pRight) ){
        r1 = rTemp = sqlite3GetTempReg(pParse);
        codeExprOrVector(pParse, pX->pRight, r1, 1);
        op = aMoveOp[(pX->op - TK_GT) | 0x0001];
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
        disableTerm(pLevel, pStart);
        op = aMoveOp[(pX->op - TK_GT)];
      }
      sqlite3VdbeAddOp3(v, op, iCur, addrBrk, r1);
      VdbeComment((v, "pk"));
      VdbeCoverageIf(v, pX->op==TK_GT);
      VdbeCoverageIf(v, pX->op==TK_LE);
      VdbeCoverageIf(v, pX->op==TK_LT);
      VdbeCoverageIf(v, pX->op==TK_GE);
      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
      sqlite3ReleaseTempReg(pParse, rTemp);

    }else{
      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
      VdbeCoverageIf(v, bRev==0);
      VdbeCoverageIf(v, bRev!=0);
    }
    if( pEnd ){
      Expr *pX;
      pX = pEnd->pExpr;
      assert( pX!=0 );
      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
      testcase( pEnd->wtFlags & TERM_VIRTUAL );
      memEndValue = ++pParse->nMem;
      codeExprOrVector(pParse, pX->pRight, memEndValue, 1);
      if( 0==sqlite3ExprIsVector(pX->pRight) 
       && (pX->op==TK_LT || pX->op==TK_GT) 
      ){
        testOp = bRev ? OP_Le : OP_Ge;
      }else{
        testOp = bRev ? OP_Lt : OP_Gt;
      }
      if( 0==sqlite3ExprIsVector(pX->pRight) ){
        disableTerm(pLevel, pEnd);
      }
    }
    start = sqlite3VdbeCurrentAddr(v);
    pLevel->op = bRev ? OP_Prev : OP_Next;
    pLevel->p1 = iCur;
    pLevel->p2 = start;
    assert( pLevel->p5==0 );
    if( testOp!=OP_Noop ){

    static const u8 aEndOp[] = {
      OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */
      OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */
      OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */
      OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */
    };
    u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */
    u16 nBtm = pLoop->u.btree.nBtm;   /* Length of BTM vector */
    u16 nTop = pLoop->u.btree.nTop;   /* Length of TOP vector */
    int regBase;                 /* Base register holding constraint values */
    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
    int startEq;                 /* True if range start uses ==, >= or <= */
    int endEq;                   /* True if range end uses ==, >= or <= */
    int start_constraints;       /* Start of range is constrained */
    int nConstraint;             /* Number of constraint terms */
    Index *pIdx;                 /* The index we will be using */
    int iIdxCur;                 /* The VDBE cursor for the index */
    int nExtraReg = 0;           /* Number of extra registers needed */
    int op;                      /* Instruction opcode */
    char *zStartAff;             /* Affinity for start of range constraint */
    char *zEndAff = 0;           /* Affinity for end of range constraint */
    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */

    pIdx = pLoop->u.btree.pIndex;
    iIdxCur = pLevel->iIdxCur;
    assert( nEq>=pLoop->nSkip );

    /* Find any inequality constraint terms for the start and end 
    ** of the range. 
    */
    j = nEq;
    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
      pRangeStart = pLoop->aLTerm[j++];
      nExtraReg = MAX(nExtraReg, pLoop->u.btree.nBtm);
      /* Like optimization range constraints always occur in pairs */
      assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 
              (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
    }
    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
      pRangeEnd = pLoop->aLTerm[j++];
      nExtraReg = MAX(nExtraReg, pLoop->u.btree.nTop);
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
        pLevel->iLikeRepCntr = (u32)++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
        VdbeComment((v, "LIKE loop counter"));

    ** start and end terms (pRangeStart and pRangeEnd).
    */
    if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
     || (bRev && pIdx->nKeyCol==nEq)
    ){
      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
      SWAP(u8, bSeekPastNull, bStopAtNull);
      SWAP(u8, nBtm, nTop);
    }

    /* Generate code to evaluate all constraint terms using == or IN
    ** and store the values of those terms in an array of registers
    ** starting at regBase.
    */
    codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
    assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
    if( zStartAff && nTop ){
      zEndAff = sqlite3DbStrDup(db, &zStartAff[nEq]);
    }
    addrNxt = pLevel->addrNxt;

    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
    start_constraints = pRangeStart || nEq>0;

    /* Seek the index cursor to the start of the range. */
    nConstraint = nEq;
    if( pRangeStart ){
      Expr *pRight = pRangeStart->pExpr->pRight;
      codeExprOrVector(pParse, pRight, regBase+nEq, nBtm);
      whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
      if( (pRangeStart->wtFlags & TERM_VNULL)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
        VdbeCoverage(v);
      }
      if( zStartAff ){




        updateRangeAffinityStr(pParse, pRight, nBtm, &zStartAff[nEq]);
      }  




      nConstraint += nBtm;
      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
      if( sqlite3ExprIsVector(pRight)==0 ){
        disableTerm(pLevel, pRangeStart);
      }else{
        startEq = 1;
      }
      bSeekPastNull = 0;
    }else if( bSeekPastNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
      nConstraint++;
      startEq = 0;
      start_constraints = 1;
    }

    /* Load the value for the inequality constraint at the end of the
    ** range (if any).
    */
    nConstraint = nEq;
    if( pRangeEnd ){
      Expr *pRight = pRangeEnd->pExpr->pRight;
      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
      codeExprOrVector(pParse, pRight, regBase+nEq, nTop);
      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
        VdbeCoverage(v);
      }
      if( zEndAff ){
        updateRangeAffinityStr(pParse, pRight, nTop, zEndAff);

        codeApplyAffinity(pParse, regBase+nEq, nTop, zEndAff);
      }else{
        assert( pParse->db->mallocFailed );
      }
      nConstraint += nTop;
      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );

      if( sqlite3ExprIsVector(pRight)==0 ){
        disableTerm(pLevel, pRangeEnd);
      }else{
        endEq = 1;
      }
    }else if( bStopAtNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
      endEq = 0;
      nConstraint++;
    }
    sqlite3DbFree(db, zStartAff);
    sqlite3DbFree(db, zEndAff);

    /* Top of the loop body */
    pLevel->p2 = sqlite3VdbeCurrentAddr(v);

    /* Check if the index cursor is past the end of the range. */
    if( nConstraint ){
      op = aEndOp[bRev*2 + endEq];
      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
      testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );
      testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
      testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
      testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
    }

    /* Seek the table cursor, if required */


    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){
      if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE)!=0 ){
        iRowidReg = ++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);

        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
      }
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
                           iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
    }

    /* Record the instruction used to terminate the loop. */


    if( pLoop->wsFlags & WHERE_ONEROW ){
      pLevel->op = OP_Noop;
    }else if( bRev ){
      pLevel->op = OP_Prev;
    }else{
      pLevel->op = OP_Next;
    }

    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
    int iRetInit;                             /* Address of regReturn init */
    int untestedTerms = 0;             /* Some terms not completely tested */
    int ii;                            /* Loop counter */
    u16 wctrlFlags;                    /* Flags for sub-WHERE clause */
    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
    Table *pTab = pTabItem->pTab;

    pTerm = pLoop->aLTerm[0];
    assert( pTerm!=0 );
    assert( pTerm->eOperator & WO_OR );
    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
    pOrWc = &pTerm->u.pOrInfo->wc;
    pLevel->op = OP_Return;
    pLevel->p1 = regReturn;

  pTerm->iParent = -1;
  return idx;
}

/*
** Return TRUE if the given operator is one of the operators that is
** allowed for an indexable WHERE clause term.  The allowed operators are
** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL"
*/
static int allowedOp(int op){
  assert( TK_GT>TK_EQ && TK_GT<TK_GE );
  assert( TK_LT>TK_EQ && TK_LT<TK_GE );
  assert( TK_LE>TK_EQ && TK_LE<TK_GE );
  assert( TK_GE==TK_EQ+4 );
  return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;

/*
** Expression pExpr is one operand of a comparison operator that might
** be useful for indexing.  This routine checks to see if pExpr appears
** in any index.  Return TRUE (1) if pExpr is an indexed term and return
** FALSE (0) if not.  If TRUE is returned, also set *piCur to the cursor
** number of the table that is indexed and *piColumn to the column number
** of the column that is indexed, or XN_EXPR (-2) if an expression is being
** indexed.
**
** If pExpr is a TK_COLUMN column reference, then this routine always returns
** true even if that particular column is not indexed, because the column
** might be added to an automatic index later.
*/
static int exprMightBeIndexed(
  SrcList *pFrom,        /* The FROM clause */
  int op,                /* The specific comparison operator */
  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
  Expr *pExpr,           /* An operand of a comparison operator */
  int *piCur,            /* Write the referenced table cursor number here */
  int *piColumn          /* Write the referenced table column number here */
){
  Index *pIdx;
  int i;
  int iCur;

  /* If this expression is a vector to the left or right of a 
  ** inequality constraint (>, <, >= or <=), perform the processing 
  ** on the first element of the vector.  */
  assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE );
  assert( TK_IS<TK_GE && TK_ISNULL<TK_GE && TK_IN<TK_GE );
  assert( op<=TK_GE );
  if( pExpr->op==TK_VECTOR && (op>=TK_GT && ALWAYS(op<=TK_GE)) ){
    pExpr = pExpr->x.pList->a[0].pExpr;
  }

  if( pExpr->op==TK_COLUMN ){
    *piCur = pExpr->iTable;
    *piColumn = pExpr->iColumn;
    return 1;
  }
  if( mPrereq==0 ) return 0;                 /* No table references */
  if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */
  for(i=0; mPrereq>1; i++, mPrereq>>=1){}
  iCur = pFrom->a[i].iCursor;
  for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    if( pIdx->aColExpr==0 ) continue;
    for(i=0; i<pIdx->nKeyCol; i++){
      if( pIdx->aiColumn[i]!=XN_EXPR ) continue;
      if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
        *piCur = iCur;
        *piColumn = XN_EXPR;
        return 1;
      }
    }
  }
  return 0;
}

  pMaskSet = &pWInfo->sMaskSet;
  pExpr = pTerm->pExpr;
  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
  prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
  op = pExpr->op;
  if( op==TK_IN ){
    assert( pExpr->pRight==0 );
    if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
      pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
    }else{
      pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
    }
  }else if( op==TK_ISNULL ){
    pTerm->prereqRight = 0;

  pTerm->iParent = -1;
  pTerm->eOperator = 0;
  if( allowedOp(op) ){
    int iCur, iColumn;
    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;

    if( pTerm->iField>0 ){
      assert( op==TK_IN );
      assert( pLeft->op==TK_VECTOR );
      pLeft = pLeft->x.pList->a[pTerm->iField-1].pExpr;
    }

    if( exprMightBeIndexed(pSrc, op, prereqLeft, pLeft, &iCur, &iColumn) ){
      pTerm->leftCursor = iCur;
      pTerm->u.leftColumn = iColumn;
      pTerm->eOperator = operatorMask(op) & opMask;
    }
    if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
    if( pRight 
     && exprMightBeIndexed(pSrc, op, pTerm->prereqRight, pRight, &iCur,&iColumn)
    ){
      WhereTerm *pNew;
      Expr *pDup;
      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
      assert( pTerm->iField==0 );
      if( pTerm->leftCursor>=0 ){
        int idxNew;
        pDup = sqlite3ExprDup(db, pExpr, 0);
        if( db->mallocFailed ){
          sqlite3ExprDelete(db, pDup);
          return;
        }

      markTermAsChild(pWC, idxNew, idxTerm);
      pTerm = &pWC->a[idxTerm];
      pTerm->wtFlags |= TERM_COPIED;
      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  /* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create
  ** new terms for each component comparison - "a = ?" and "b = ?".  The
  ** new terms completely replace the original vector comparison, which is
  ** no longer used.
  **
  ** This is only required if at least one side of the comparison operation
  ** is not a sub-select.  */
  if( pWC->op==TK_AND 
  && (pExpr->op==TK_EQ || pExpr->op==TK_IS)
  && sqlite3ExprIsVector(pExpr->pLeft)
  && ( (pExpr->pLeft->flags & EP_xIsSelect)==0 
    || (pExpr->pRight->flags & EP_xIsSelect)==0
  )){
    int nLeft = sqlite3ExprVectorSize(pExpr->pLeft);
    int i;
    assert( nLeft==sqlite3ExprVectorSize(pExpr->pRight) );
    for(i=0; i<nLeft; i++){
      int idxNew;
      Expr *pNew;
      Expr *pLeft = sqlite3ExprForVectorField(pParse, pExpr->pLeft, i);
      Expr *pRight = sqlite3ExprForVectorField(pParse, pExpr->pRight, i);

      pNew = sqlite3PExpr(pParse, pExpr->op, pLeft, pRight, 0);
      idxNew = whereClauseInsert(pWC, pNew, TERM_DYNAMIC);
      exprAnalyze(pSrc, pWC, idxNew);
    }
    pTerm = &pWC->a[idxTerm];
    pTerm->wtFlags = TERM_CODED|TERM_VIRTUAL;  /* Disable the original */
    pTerm->eOperator = 0;
  }

  /* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create
  ** a virtual term for each vector component. The expression object
  ** used by each such virtual term is pExpr (the full vector IN(...) 
  ** expression). The WhereTerm.iField variable identifies the index within
  ** the vector on the LHS that the virtual term represents.
  **
  ** This only works if the RHS is a simple SELECT, not a compound
  */
  if( pWC->op==TK_AND && pExpr->op==TK_IN && pTerm->iField==0
   && pExpr->pLeft->op==TK_VECTOR
   && pExpr->x.pSelect->pPrior==0
  ){
    int i;
    for(i=0; i<sqlite3ExprVectorSize(pExpr->pLeft); i++){
      int idxNew;
      idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL);
      pWC->a[idxNew].iField = i+1;
      exprAnalyze(pSrc, pWC, idxNew);
      markTermAsChild(pWC, idxNew, idxTerm);
    }
  }

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  /* When sqlite_stat3 histogram data is available an operator of the
  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
  ** virtual term of that form.
  **

** by passing the pointer returned by this function to sqlite3_free().
*/
static sqlite3_index_info *allocateIndexInfo(
  Parse *pParse,
  WhereClause *pWC,
  Bitmask mUnusable,              /* Ignore terms with these prereqs */
  struct SrcList_item *pSrc,
  ExprList *pOrderBy,
  u16 *pmNoOmit                   /* Mask of terms not to omit */
){
  int i, j;
  int nTerm;
  struct sqlite3_index_constraint *pIdxCons;
  struct sqlite3_index_orderby *pIdxOrderBy;
  struct sqlite3_index_constraint_usage *pUsage;
  WhereTerm *pTerm;
  int nOrderBy;
  sqlite3_index_info *pIdxInfo;
  u16 mNoOmit = 0;

  /* Count the number of possible WHERE clause constraints referring
  ** to this virtual table */
  for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( pTerm->leftCursor != pSrc->iCursor ) continue;
    if( pTerm->prereqRight & mUnusable ) continue;
    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );

    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
    assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
    assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
    assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
    assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
    assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );

    if( op & (WO_LT|WO_LE|WO_GT|WO_GE)
     && sqlite3ExprIsVector(pTerm->pExpr->pRight) 
    ){
      if( i<16 ) mNoOmit |= (1 << i);
      if( op==WO_LT ) pIdxCons[j].op = WO_LE;
      if( op==WO_GT ) pIdxCons[j].op = WO_GE;
    }

    j++;
  }
  for(i=0; i<nOrderBy; i++){
    Expr *pExpr = pOrderBy->a[i].pExpr;
    pIdxOrderBy[i].iColumn = pExpr->iColumn;
    pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;
  }

  *pmNoOmit = mNoOmit;
  return pIdxInfo;
}

/*
** The table object reference passed as the second argument to this function
** must represent a virtual table. This function invokes the xBestIndex()
** method of the virtual table with the sqlite3_index_info object that

}


#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Return the affinity for a single column of an index.
*/
SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){
  assert( iCol>=0 && iCol<pIdx->nColumn );
  if( !pIdx->zColAff ){
    if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;
  }
  return pIdx->zColAff[iCol];
}
#endif

  Index *p = pLoop->u.btree.pIndex;
  int nEq = pLoop->u.btree.nEq;

  if( p->nSample>0 && nEq<p->nSampleCol ){
    if( nEq==pBuilder->nRecValid ){
      UnpackedRecord *pRec = pBuilder->pRec;
      tRowcnt a[2];
      int nBtm = pLoop->u.btree.nBtm;
      int nTop = pLoop->u.btree.nTop;

      /* Variable iLower will be set to the estimate of the number of rows in 
      ** the index that are less than the lower bound of the range query. The
      ** lower bound being the concatenation of $P and $L, where $P is the
      ** key-prefix formed by the nEq values matched against the nEq left-most
      ** columns of the index, and $L is the value in pLower.
      **

      int iLwrIdx = -2;   /* aSample[] for the lower bound */
      int iUprIdx = -1;   /* aSample[] for the upper bound */

      if( pRec ){
        testcase( pRec->nField!=pBuilder->nRecValid );
        pRec->nField = pBuilder->nRecValid;
      }


      /* Determine iLower and iUpper using ($P) only. */
      if( nEq==0 ){
        iLower = 0;
        iUpper = p->nRowEst0;
      }else{
        /* Note: this call could be optimized away - since the same values must 
        ** have been requested when testing key $P in whereEqualScanEst().  */
        whereKeyStats(pParse, p, pRec, 0, a);
        iLower = a[0];
        iUpper = a[0] + a[1];
      }

      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
      assert( p->aSortOrder!=0 );
      if( p->aSortOrder[nEq] ){
        /* The roles of pLower and pUpper are swapped for a DESC index */
        SWAP(WhereTerm*, pLower, pUpper);
        SWAP(int, nBtm, nTop);
      }

      /* If possible, improve on the iLower estimate using ($P:$L). */
      if( pLower ){
        int n;                    /* Values extracted from pExpr */
        Expr *pExpr = pLower->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nBtm, nEq, &n);
        if( rc==SQLITE_OK && n ){
          tRowcnt iNew;
          u16 mask = WO_GT|WO_LE;
          if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
          iNew = a[0] + ((pLower->eOperator & mask) ? a[1] : 0);
          if( iNew>iLower ) iLower = iNew;
          nOut--;
          pLower = 0;
        }
      }

      /* If possible, improve on the iUpper estimate using ($P:$U). */
      if( pUpper ){
        int n;                    /* Values extracted from pExpr */
        Expr *pExpr = pUpper->pExpr->pRight;
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nTop, nEq, &n);
        if( rc==SQLITE_OK && n ){
          tRowcnt iNew;
          u16 mask = WO_GT|WO_LE;
          if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
          iNew = a[0] + ((pUpper->eOperator & mask) ? a[1] : 0);
          if( iNew<iUpper ) iUpper = iNew;
          nOut--;
          pUpper = 0;
        }
      }

      pBuilder->pRec = pRec;

  WhereLoopBuilder *pBuilder,
  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
  tRowcnt *pnRow       /* Write the revised row estimate here */
){
  Index *p = pBuilder->pNew->u.btree.pIndex;
  int nEq = pBuilder->pNew->u.btree.nEq;
  UnpackedRecord *pRec = pBuilder->pRec;

  int rc;                   /* Subfunction return code */
  tRowcnt a[2];             /* Statistics */
  int bOk;

  assert( nEq>=1 );
  assert( nEq<=p->nColumn );
  assert( p->aSample!=0 );

  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
  ** below would return the same value.  */
  if( nEq>=p->nColumn ){
    *pnRow = 1;
    return SQLITE_OK;
  }


  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, 1, nEq-1, &bOk);
  pBuilder->pRec = pRec;
  if( rc!=SQLITE_OK ) return rc;
  if( bOk==0 ) return SQLITE_NOTFOUND;
  pBuilder->nRecValid = nEq;

  whereKeyStats(pParse, p, pRec, 0, a);
  WHERETRACE(0x10,("equality scan regions %s(%d): %d\n",

    }else if( (pTerm->eOperator & WO_OR)!=0 && pTerm->u.pOrInfo!=0 ){
      sqlite3_snprintf(sizeof(zLeft),zLeft,"indexable=0x%lld", 
                       pTerm->u.pOrInfo->indexable);
    }else{
      sqlite3_snprintf(sizeof(zLeft),zLeft,"left=%d", pTerm->leftCursor);
    }
    sqlite3DebugPrintf(
       "TERM-%-3d %p %s %-12s prob=%-3d op=0x%03x wtFlags=0x%04x",
       iTerm, pTerm, zType, zLeft, pTerm->truthProb,
       pTerm->eOperator, pTerm->wtFlags);
    if( pTerm->iField ){
      sqlite3DebugPrintf(" iField=%d\n", pTerm->iField);
    }else{
      sqlite3DebugPrintf("\n");
    }
    sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
  }
}
#endif

#ifdef WHERETRACE_ENABLED
/*

          if( iReduce<k ) iReduce = k;
        }
      }
    }
  }
  if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
}

/* 
** Term pTerm is a vector range comparison operation. The first comparison
** in the vector can be optimized using column nEq of the index. This
** function returns the total number of vector elements that can be used
** as part of the range comparison.
**
** For example, if the query is:
**
**   WHERE a = ? AND (b, c, d) > (?, ?, ?)
**
** and the index:
**
**   CREATE INDEX ... ON (a, b, c, d, e)
**
** then this function would be invoked with nEq=1. The value returned in
** this case is 3.
*/
int whereRangeVectorLen(
  Parse *pParse,       /* Parsing context */
  int iCur,            /* Cursor open on pIdx */
  Index *pIdx,         /* The index to be used for a inequality constraint */
  int nEq,             /* Number of prior equality constraints on same index */
  WhereTerm *pTerm     /* The vector inequality constraint */
){
  int nCmp = sqlite3ExprVectorSize(pTerm->pExpr->pLeft);
  int i;

  nCmp = MIN(nCmp, (pIdx->nColumn - nEq));
  for(i=1; i<nCmp; i++){
    /* Test if comparison i of pTerm is compatible with column (i+nEq) 
    ** of the index. If not, exit the loop.  */
    char aff;                     /* Comparison affinity */
    char idxaff = 0;              /* Indexed columns affinity */
    CollSeq *pColl;               /* Comparison collation sequence */
    Expr *pLhs = pTerm->pExpr->pLeft->x.pList->a[i].pExpr;
    Expr *pRhs = pTerm->pExpr->pRight;
    if( pRhs->flags & EP_xIsSelect ){
      pRhs = pRhs->x.pSelect->pEList->a[i].pExpr;
    }else{
      pRhs = pRhs->x.pList->a[i].pExpr;
    }

    /* Check that the LHS of the comparison is a column reference to
    ** the right column of the right source table. And that the sort
    ** order of the index column is the same as the sort order of the
    ** leftmost index column.  */
    if( pLhs->op!=TK_COLUMN 
     || pLhs->iTable!=iCur 
     || pLhs->iColumn!=pIdx->aiColumn[i+nEq] 
     || pIdx->aSortOrder[i+nEq]!=pIdx->aSortOrder[nEq]
    ){
      break;
    }

    testcase( pLhs->iColumn==XN_ROWID );
    aff = sqlite3CompareAffinity(pRhs, sqlite3ExprAffinity(pLhs));
    idxaff = sqlite3TableColumnAffinity(pIdx->pTable, pLhs->iColumn);
    if( aff!=idxaff ) break;

    pColl = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
    if( pColl==0 ) break;
    if( sqlite3StrICmp(pColl->zName, pIdx->azColl[i+nEq]) ) break;
  }
  return i;
}

/*
** Adjust the cost C by the costMult facter T.  This only occurs if
** compiled with -DSQLITE_ENABLE_COSTMULT
*/
#ifdef SQLITE_ENABLE_COSTMULT
# define ApplyCostMultiplier(C,T)  C += T

  WhereLoop *pNew;                /* Template WhereLoop under construction */
  WhereTerm *pTerm;               /* A WhereTerm under consideration */
  int opMask;                     /* Valid operators for constraints */
  WhereScan scan;                 /* Iterator for WHERE terms */
  Bitmask saved_prereq;           /* Original value of pNew->prereq */
  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
  u16 saved_nBtm;                 /* Original value of pNew->u.btree.nBtm */
  u16 saved_nTop;                 /* Original value of pNew->u.btree.nTop */
  u16 saved_nSkip;                /* Original value of pNew->nSkip */
  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
  LogEst saved_nOut;              /* Original value of pNew->nOut */
  int rc = SQLITE_OK;             /* Return code */
  LogEst rSize;                   /* Number of rows in the table */
  LogEst rLogSize;                /* Logarithm of table size */
  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */

  pNew = pBuilder->pNew;
  if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;

  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
    opMask = WO_LT|WO_LE;
  }else{
    assert( pNew->u.btree.nBtm==0 );
    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
  }
  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);

  assert( pNew->u.btree.nEq<pProbe->nColumn );

  saved_nEq = pNew->u.btree.nEq;
  saved_nBtm = pNew->u.btree.nBtm;
  saved_nTop = pNew->u.btree.nTop;
  saved_nSkip = pNew->nSkip;
  saved_nLTerm = pNew->nLTerm;
  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
                        opMask, pProbe);

      testcase( eOp & WO_IS );
      testcase( eOp & WO_ISNULL );
      continue;
    }

    pNew->wsFlags = saved_wsFlags;
    pNew->u.btree.nEq = saved_nEq;
    pNew->u.btree.nBtm = saved_nBtm;
    pNew->u.btree.nTop = saved_nTop;
    pNew->nLTerm = saved_nLTerm;
    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
    pNew->aLTerm[pNew->nLTerm++] = pTerm;
    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;

    assert( nInMul==0
        || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 
        || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 
        || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 
    );

    if( eOp & WO_IN ){
      Expr *pExpr = pTerm->pExpr;
      pNew->wsFlags |= WHERE_COLUMN_IN;
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
        int i;
        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]->pExpr==pExpr ) nIn = 0;
        }
      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
        /* "x IN (value, value, ...)" */
        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);

        assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
                          ** changes "x IN (?)" into "x=?". */
      }
    }else if( eOp & (WO_EQ|WO_IS) ){
      int iCol = pProbe->aiColumn[saved_nEq];
      pNew->wsFlags |= WHERE_COLUMN_EQ;
      assert( saved_nEq==pNew->u.btree.nEq );
      if( iCol==XN_ROWID 
       || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
      ){
        if( iCol>=0 && pProbe->uniqNotNull==0 ){
          pNew->wsFlags |= WHERE_UNQ_WANTED;
        }else{
          pNew->wsFlags |= WHERE_ONEROW;
        }
      }
    }else if( eOp & WO_ISNULL ){
      pNew->wsFlags |= WHERE_COLUMN_NULL;
    }else if( eOp & (WO_GT|WO_GE) ){
      testcase( eOp & WO_GT );
      testcase( eOp & WO_GE );
      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
      pNew->u.btree.nBtm = whereRangeVectorLen(
          pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
      );
      pBtm = pTerm;
      pTop = 0;
      if( pTerm->wtFlags & TERM_LIKEOPT ){
        /* Range contraints that come from the LIKE optimization are
        ** always used in pairs. */
        pTop = &pTerm[1];
        assert( (pTop-(pTerm->pWC->a))<pTerm->pWC->nTerm );
        assert( pTop->wtFlags & TERM_LIKEOPT );
        assert( pTop->eOperator==WO_LT );
        if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
        pNew->aLTerm[pNew->nLTerm++] = pTop;
        pNew->wsFlags |= WHERE_TOP_LIMIT;
        pNew->u.btree.nTop = 1;
      }
    }else{
      assert( eOp & (WO_LT|WO_LE) );
      testcase( eOp & WO_LT );
      testcase( eOp & WO_LE );
      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
      pNew->u.btree.nTop = whereRangeVectorLen(
          pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
      );
      pTop = pTerm;
      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
                     pNew->aLTerm[pNew->nLTerm-2] : 0;
    }

    /* At this point pNew->nOut is set to the number of rows expected to
    ** be visited by the index scan before considering term pTerm, or the

    pNew->nOut = saved_nOut;
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    pBuilder->nRecValid = nRecValid;
#endif
  }
  pNew->prereq = saved_prereq;
  pNew->u.btree.nEq = saved_nEq;
  pNew->u.btree.nBtm = saved_nBtm;
  pNew->u.btree.nTop = saved_nTop;
  pNew->nSkip = saved_nSkip;
  pNew->wsFlags = saved_wsFlags;
  pNew->nOut = saved_nOut;
  pNew->nLTerm = saved_nLTerm;

  /* Consider using a skip-scan if there are no WHERE clause constraints
  ** available for the left-most terms of the index, and if the average

    }
  }
  return 0;
}

/*
** Add all WhereLoop objects for a single table of the join where the table
** is identified by pBuilder->pNew->iTab.  That table is guaranteed to be
** a b-tree table, not a virtual table.
**
** The costs (WhereLoop.rRun) of the b-tree loops added by this function
** are calculated as follows:
**
** For a full scan, assuming the table (or index) contains nRow rows:
**

    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
    pNew->u.btree.nBtm = 0;
    pNew->u.btree.nTop = 0;
    pNew->nSkip = 0;
    pNew->nLTerm = 0;
    pNew->iSortIdx = 0;
    pNew->rSetup = 0;
    pNew->prereq = mPrereq;
    pNew->nOut = rSize;
    pNew->u.btree.pIndex = pProbe;

*/
static int whereLoopAddVirtualOne(
  WhereLoopBuilder *pBuilder,
  Bitmask mPrereq,                /* Mask of tables that must be used. */
  Bitmask mUsable,                /* Mask of usable tables */
  u16 mExclude,                   /* Exclude terms using these operators */
  sqlite3_index_info *pIdxInfo,   /* Populated object for xBestIndex */
  u16 mNoOmit,                    /* Do not omit these constraints */
  int *pbIn                       /* OUT: True if plan uses an IN(...) op */
){
  WhereClause *pWC = pBuilder->pWC;
  struct sqlite3_index_constraint *pIdxCons;
  struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;
  int i;
  int mxTerm;

        ** together.  */
        pIdxInfo->orderByConsumed = 0;
        pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
        *pbIn = 1; assert( (mExclude & WO_IN)==0 );
      }
    }
  }
  pNew->u.vtab.omitMask &= ~mNoOmit;

  pNew->nLTerm = mxTerm+1;
  assert( pNew->nLTerm<=pNew->nLSlot );
  pNew->u.vtab.idxNum = pIdxInfo->idxNum;
  pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
  pIdxInfo->needToFreeIdxStr = 0;
  pNew->u.vtab.idxStr = pIdxInfo->idxStr;

  WhereClause *pWC;            /* The WHERE clause */
  struct SrcList_item *pSrc;   /* The FROM clause term to search */
  sqlite3_index_info *p;       /* Object to pass to xBestIndex() */
  int nConstraint;             /* Number of constraints in p */
  int bIn;                     /* True if plan uses IN(...) operator */
  WhereLoop *pNew;
  Bitmask mBest;               /* Tables used by best possible plan */
  u16 mNoOmit;

  assert( (mPrereq & mUnusable)==0 );
  pWInfo = pBuilder->pWInfo;
  pParse = pWInfo->pParse;
  pWC = pBuilder->pWC;
  pNew = pBuilder->pNew;
  pSrc = &pWInfo->pTabList->a[pNew->iTab];
  assert( IsVirtual(pSrc->pTab) );
  p = allocateIndexInfo(pParse, pWC, mUnusable, pSrc, pBuilder->pOrderBy, 
      &mNoOmit);
  if( p==0 ) return SQLITE_NOMEM_BKPT;
  pNew->rSetup = 0;
  pNew->wsFlags = WHERE_VIRTUALTABLE;
  pNew->nLTerm = 0;
  pNew->u.vtab.needFree = 0;
  nConstraint = p->nConstraint;
  if( whereLoopResize(pParse->db, pNew, nConstraint) ){
    sqlite3DbFree(pParse->db, p);
    return SQLITE_NOMEM_BKPT;
  }

  /* First call xBestIndex() with all constraints usable. */
  WHERETRACE(0x40, ("  VirtualOne: all usable\n"));
  rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn);

  /* If the call to xBestIndex() with all terms enabled produced a plan
  ** that does not require any source tables (IOW: a plan with mBest==0),
  ** then there is no point in making any further calls to xBestIndex() 
  ** since they will all return the same result (if the xBestIndex()
  ** implementation is sane). */
  if( rc==SQLITE_OK && (mBest = (pNew->prereq & ~mPrereq))!=0 ){
    int seenZero = 0;             /* True if a plan with no prereqs seen */
    int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
    Bitmask mPrev = 0;
    Bitmask mBestNoIn = 0;

    /* If the plan produced by the earlier call uses an IN(...) term, call
    ** xBestIndex again, this time with IN(...) terms disabled. */
    if( bIn ){
      WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, ALLBITS, WO_IN, p, mNoOmit, &bIn);
      assert( bIn==0 );
      mBestNoIn = pNew->prereq & ~mPrereq;
      if( mBestNoIn==0 ){
        seenZero = 1;
        seenZeroNoIN = 1;
      }
    }

        if( mThis>mPrev && mThis<mNext ) mNext = mThis;
      }
      mPrev = mNext;
      if( mNext==ALLBITS ) break;
      if( mNext==mBest || mNext==mBestNoIn ) continue;
      WHERETRACE(0x40, ("  VirtualOne: mPrev=%04llx mNext=%04llx\n",
                       (sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mNext|mPrereq, 0, p, mNoOmit, &bIn);
      if( pNew->prereq==mPrereq ){
        seenZero = 1;
        if( bIn==0 ) seenZeroNoIN = 1;
      }
    }

    /* If the calls to xBestIndex() in the above loop did not find a plan
    ** that requires no source tables at all (i.e. one guaranteed to be
    ** usable), make a call here with all source tables disabled */
    if( rc==SQLITE_OK && seenZero==0 ){
      WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mPrereq, 0, p, mNoOmit, &bIn);
      if( bIn==0 ) seenZeroNoIN = 1;
    }

    /* If the calls to xBestIndex() have so far failed to find a plan
    ** that requires no source tables at all and does not use an IN(...)
    ** operator, make a final call to obtain one here.  */
    if( rc==SQLITE_OK && seenZeroNoIN==0 ){
      WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn);
    }
  }

  if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);
  sqlite3DbFree(pParse->db, p);
  return rc;
}

      if( MASKBIT(i) & obSat ) continue;
      pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
      if( pOBExpr->op!=TK_COLUMN ) continue;
      if( pOBExpr->iTable!=iCur ) continue;
      pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
                       ~ready, eqOpMask, 0);
      if( pTerm==0 ) continue;
      if( pTerm->eOperator==WO_IN ){
        /* IN terms are only valid for sorting in the ORDER BY LIMIT 
        ** optimization, and then only if they are actually used
        ** by the query plan */
        assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
        for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
        if( j>=pLoop->nLTerm ) continue;
      }
      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
        const char *z1, *z2;
        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
        if( !pColl ) pColl = db->pDfltColl;
        z1 = pColl->zName;
        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
        if( !pColl ) pColl = db->pDfltColl;

      /* Loop through all columns of the index and deal with the ones
      ** that are not constrained by == or IN.
      */
      rev = revSet = 0;
      distinctColumns = 0;
      for(j=0; j<nColumn; j++){
        u8 bOnce = 1; /* True to run the ORDER BY search loop */

        assert( j>=pLoop->u.btree.nEq 
            || (pLoop->aLTerm[j]==0)==(j<pLoop->nSkip)
        );
        if( j<pLoop->u.btree.nEq && j>=pLoop->nSkip ){
          u16 eOp = pLoop->aLTerm[j]->eOperator;

          /* Skip over == and IS and ISNULL terms.  (Also skip IN terms when
          ** doing WHERE_ORDERBY_LIMIT processing). 
          **


          ** If the current term is a column of an ((?,?) IN (SELECT...)) 
          ** expression for which the SELECT returns more than one column,
          ** check that it is the only column used by this loop. Otherwise,
          ** if it is one of two or more, none of the columns can be
          ** considered to match an ORDER BY term.  */
          if( (eOp & eqOpMask)!=0 ){

            if( eOp & WO_ISNULL ){
              testcase( isOrderDistinct );
              isOrderDistinct = 0;
            }
            continue;  
          }else if( ALWAYS(eOp & WO_IN) ){
            /* ALWAYS() justification: eOp is an equality operator due to the
            ** j<pLoop->u.btree.nEq constraint above.  Any equality other
            ** than WO_IN is captured by the previous "if".  So this one
            ** always has to be WO_IN. */
            Expr *pX = pLoop->aLTerm[j]->pExpr;
            for(i=j+1; i<pLoop->u.btree.nEq; i++){
              if( pLoop->aLTerm[i]->pExpr==pX ){
                assert( (pLoop->aLTerm[i]->eOperator & WO_IN) );
                bOnce = 0;
                break;
              }
            }
          }
        }

        /* Get the column number in the table (iColumn) and sort order
        ** (revIdx) for the j-th column of the index.
        */
        if( pIndex ){
          iColumn = pIndex->aiColumn[j];

        ){
          isOrderDistinct = 0;
        }

        /* Find the ORDER BY term that corresponds to the j-th column
        ** of the index and mark that ORDER BY term off 
        */

        isMatch = 0;
        for(i=0; bOnce && i<nOrderBy; i++){
          if( MASKBIT(i) & obSat ) continue;
          pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
          testcase( wctrlFlags & WHERE_GROUPBY );
          testcase( wctrlFlags & WHERE_DISTINCTBY );
          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;

    }
    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
      struct InLoop *pIn;
      int j;
      sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
      for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
        sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
        if( pIn->eEndLoopOp!=OP_Noop ){
          sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
          VdbeCoverage(v);
          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
        }
        sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
      }
    }
    sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
    if( pLevel->addrSkip ){
      sqlite3VdbeGoto(v, pLevel->addrSkip);
      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));

#define YYSTACKDEPTH 100
#endif
#define sqlite3ParserARG_SDECL Parse *pParse;
#define sqlite3ParserARG_PDECL ,Parse *pParse
#define sqlite3ParserARG_FETCH Parse *pParse = yypParser->pParse
#define sqlite3ParserARG_STORE yypParser->pParse = pParse
#define YYFALLBACK 1
#define YYNSTATE             456
#define YYNRULE              331
#define YY_MAX_SHIFT         455
#define YY_MIN_SHIFTREDUCE   667
#define YY_MAX_SHIFTREDUCE   997
#define YY_MIN_REDUCE        998
#define YY_MAX_REDUCE        1328
#define YY_ERROR_ACTION      1329
#define YY_ACCEPT_ACTION     1330
#define YY_NO_ACTION         1331
/************* End control #defines *******************************************/

/* Define the yytestcase() macro to be a no-op if is not already defined
** otherwise.
**
** Applications can choose to define yytestcase() in the %include section
** to a macro that can assist in verifying code coverage.  For production