**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.12"
#define SQLITE_VERSION_NUMBER 3008012
#define SQLITE_SOURCE_ID      "2015-09-28 14:40:20 9d057f52217e7ef9c3f3eb84117abe3365503f44"

/*
** 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
................................................................................
** strategy. A cost of N indicates that the cost of the strategy is similar
** to a linear scan of an SQLite table with N rows. A cost of log(N) 
** indicates that the expense of the operation is similar to that of a
** binary search on a unique indexed field of an SQLite table with N rows.
**
** ^The estimatedRows value is an estimate of the number of rows that
** will be returned by the strategy.















**
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
** structure for SQLite version 3.8.2. If a virtual table extension is
** used with an SQLite version earlier than 3.8.2, the results of attempting 
** to read or write the estimatedRows field are undefined (but are likely 
** to included crashing the application). The estimatedRows field should
** therefore only be used if [sqlite3_libversion_number()] returns a
** value greater than or equal to 3008002.



*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
................................................................................
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */


};






/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the wHERE clause of
** a query that uses a [virtual table].
................................................................................
*/
#if !defined(SQLITE_DISABLE_INTRINSIC)
#  if defined(_MSC_VER) && _MSC_VER>=1300
#    if !defined(_WIN32_WCE)
#      include <intrin.h>
#      pragma intrinsic(_byteswap_ushort)
#      pragma intrinsic(_byteswap_ulong)

#    else
#      include <cmnintrin.h>
#    endif
#  endif
#endif

/*
................................................................................
#define OP_RowSetTest    131 /* synopsis: if r[P3] in rowset(P1) goto P2   */
#define OP_Program       132
#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
#define OP_Param         134
#define OP_FkCounter     135 /* synopsis: fkctr[P1]+=P2                    */
#define OP_FkIfZero      136 /* synopsis: if fkctr[P1]==0 goto P2          */
#define OP_MemMax        137 /* synopsis: r[P1]=max(r[P1],r[P2])           */
#define OP_IfPos         138 /* synopsis: if r[P1]>0 goto P2               */
#define OP_IfNeg         139 /* synopsis: r[P1]+=P3, if r[P1]<0 goto P2    */
#define OP_IfNotZero     140 /* synopsis: if r[P1]!=0 then r[P1]+=P3, goto P2 */
#define OP_DecrJumpZero  141 /* synopsis: if (--r[P1])==0 goto P2          */
#define OP_JumpZeroIncr  142 /* synopsis: if (r[P1]++)==0 ) goto P2        */
#define OP_AggStep0      143 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggStep       144 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggFinal      145 /* synopsis: accum=r[P1] N=P2                 */
#define OP_IncrVacuum    146
#define OP_Expire        147
................................................................................
/*  80 */ 0x0b, 0x0b, 0x0b, 0x0b, 0x00, 0x26, 0x26, 0x26,\
/*  88 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x00,\
/*  96 */ 0x12, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 104 */ 0x10, 0x00, 0x01, 0x01, 0x01, 0x01, 0x04, 0x04,\
/* 112 */ 0x00, 0x10, 0x01, 0x01, 0x01, 0x01, 0x10, 0x00,\
/* 120 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 128 */ 0x00, 0x06, 0x23, 0x0b, 0x01, 0x10, 0x10, 0x00,\
/* 136 */ 0x01, 0x04, 0x03, 0x03, 0x03, 0x03, 0x03, 0x00,\
/* 144 */ 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 152 */ 0x00, 0x00, 0x01, 0x00, 0x10, 0x10, 0x01, 0x00,\
/* 160 */ 0x00,}

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

................................................................................

/* Return true if index X is a PRIMARY KEY index */
#define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)

/* Return true if index X is a UNIQUE index */
#define IsUniqueIndex(X)      ((X)->onError!=OE_None)







/*
** Each sample stored in the sqlite_stat3 table is represented in memory 
** using a structure of this type.  See documentation at the top of the
** analyze.c source file for additional information.
*/
struct IndexSample {
  void *p;          /* Pointer to sampled record */
................................................................................
                                        Select*,u8);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
SQLITE_PRIVATE   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
# define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))

#else
# define sqlite3TriggersExist(B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A,B)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
# define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
# define sqlite3TriggerList(X, Y) 0
# define sqlite3ParseToplevel(p) p

# define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
#endif

SQLITE_PRIVATE int sqlite3JoinType(Parse*, Token*, Token*, Token*);
SQLITE_PRIVATE void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
................................................................................
** compiled without mutexes (SQLITE_THREADSAFE=0).
*/
SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__)
  __sync_synchronize();
#else



  MemoryBarrier();
#endif
}

/*
** Initialize and deinitialize the mutex subsystem.
*/
................................................................................
     /* 131 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
     /* 132 */ "Program"          OpHelp(""),
     /* 133 */ "Real"             OpHelp("r[P2]=P4"),
     /* 134 */ "Param"            OpHelp(""),
     /* 135 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
     /* 136 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
     /* 137 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
     /* 138 */ "IfPos"            OpHelp("if r[P1]>0 goto P2"),
     /* 139 */ "IfNeg"            OpHelp("r[P1]+=P3, if r[P1]<0 goto P2"),
     /* 140 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]+=P3, goto P2"),
     /* 141 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
     /* 142 */ "JumpZeroIncr"     OpHelp("if (r[P1]++)==0 ) goto P2"),
     /* 143 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
     /* 144 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
     /* 145 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
     /* 146 */ "IncrVacuum"       OpHelp(""),
     /* 147 */ "Expire"           OpHelp(""),
................................................................................

  rc = saveCursorKey(pCur);
  if( rc==SQLITE_OK ){
    btreeReleaseAllCursorPages(pCur);
    pCur->eState = CURSOR_REQUIRESEEK;
  }

  invalidateOverflowCache(pCur);
  return rc;
}

/* Forward reference */
static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);

/*
................................................................................
    ** for which the pointer is stored within the content being copied.
    **
    ** It is critical that the child page be defragmented before being
    ** copied into the parent, because if the parent is page 1 then it will
    ** by smaller than the child due to the database header, and so all the
    ** free space needs to be up front.
    */
    assert( nNew==1 );
    rc = defragmentPage(apNew[0]);
    testcase( rc!=SQLITE_OK );
    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
      || rc!=SQLITE_OK
    );
    copyNodeContent(apNew[0], pParent, &rc);
................................................................................
  if( pIn1->u.i<pIn2->u.i){
    pIn1->u.i = pIn2->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfPos P1 P2 * * *
** Synopsis: if r[P1]>0 goto P2
**
** Register P1 must contain an integer.
** If the value of register P1 is 1 or greater, jump to P2 and
** add the literal value P3 to register P1.
**
** If the initial value of register P1 is less than 1, then the
** value is unchanged and control passes through to the next instruction.
*/
case OP_IfPos: {        /* jump, in1 */
  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  VdbeBranchTaken( pIn1->u.i>0, 2);
  if( pIn1->u.i>0 ) goto jump_to_p2;



  break;
}

/* Opcode: IfNeg P1 P2 P3 * *
** Synopsis: r[P1]+=P3, if r[P1]<0 goto P2
**
** Register P1 must contain an integer.  Add literal P3 to the value in
** register P1 then if the value of register P1 is less than zero, jump to P2. 

*/
case OP_IfNeg: {        /* jump, in1 */

  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  pIn1->u.i += pOp->p3;
  VdbeBranchTaken(pIn1->u.i<0, 2);
  if( pIn1->u.i<0 ) goto jump_to_p2;



  break;
}

/* Opcode: IfNotZero P1 P2 P3 * *
** Synopsis: if r[P1]!=0 then r[P1]+=P3, goto P2
**
** Register P1 must contain an integer.  If the content of register P1 is

** initially nonzero, then add P3 to P1 and jump to P2.  If register P1 is
** initially zero, leave it unchanged and fall through.
*/
case OP_IfNotZero: {        /* jump, in1 */
  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  VdbeBranchTaken(pIn1->u.i<0, 2);
  if( pIn1->u.i ){
     pIn1->u.i += pOp->p3;
     goto jump_to_p2;
  }
  break;
}

/* Opcode: DecrJumpZero P1 P2 * * *
** Synopsis: if (--r[P1])==0 goto P2
................................................................................
        }
      }
#endif
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nKeyCol; j++){
          /* FIXME: Be smarter about indexes that use expressions */
          if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==(-2) ){
            zFault = "indexed";
          }
        }
      }
      if( zFault ){
        sqlite3DbFree(db, zErr);
        zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
................................................................................
  Parse *pParse,  /* The parsing context */
  Index *pIdx,    /* The index whose column is to be loaded */
  int iTabCur,    /* Cursor pointing to a table row */
  int iIdxCol,    /* The column of the index to be loaded */
  int regOut      /* Store the index column value in this register */
){
  i16 iTabCol = pIdx->aiColumn[iIdxCol];
  if( iTabCol>=(-1) ){
    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
                                    iTabCol, regOut);
    return;
  }
  assert( pIdx->aColExpr );
  assert( pIdx->aColExpr->nExpr>iIdxCol );
  pParse->iSelfTab = iTabCur;
  sqlite3ExprCode(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);




}

/*
** Generate code to extract the value of the iCol-th column of a table.
*/
SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
  Vdbe *v,        /* The VDBE under construction */
................................................................................
          OP_Transaction,                    /* Opcode */
          iDb,                               /* P1 */
          DbMaskTest(pParse->writeMask,iDb), /* P2 */
          pParse->cookieValue[iDb],          /* P3 */
          db->aDb[iDb].pSchema->iGeneration  /* P4 */
        );
        if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);


      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      for(i=0; i<pParse->nVtabLock; i++){
        char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
        sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
      }
      pParse->nVtabLock = 0;
................................................................................
  }else{
    sortOrderMask = 0;    /* Ignore DESC */
  }

  /* Analyze the list of expressions that form the terms of the index and
  ** report any errors.  In the common case where the expression is exactly
  ** a table column, store that column in aiColumn[].  For general expressions,
  ** populate pIndex->aColExpr and store -2 in aiColumn[].
  **
  ** TODO: Issue a warning if two or more columns of the index are identical.
  ** TODO: Issue a warning if the table primary key is used as part of the
  ** index key.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    Expr *pCExpr;                  /* The i-th index expression */
................................................................................
        ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
        pIndex->aColExpr = pCopy;
        if( !db->mallocFailed ){
          assert( pCopy!=0 );
          pListItem = &pCopy->a[i];
        }
      }
      j = -2;
      pIndex->aiColumn[i] = -2;
      pIndex->uniqNotNull = 0;
    }else{
      j = pCExpr->iColumn;
      assert( j<=0x7fff );
      if( j<0 ){
        j = pTab->iPKey;
      }else if( pTab->aCol[j].notNull==0 ){
................................................................................
        pIndex->azColl[i] = pPk->azColl[j];
        pIndex->aSortOrder[i] = pPk->aSortOrder[j];
        i++;
      }
    }
    assert( i==pIndex->nColumn );
  }else{
    pIndex->aiColumn[i] = -1;
    pIndex->azColl[i] = "BINARY";
  }
  sqlite3DefaultRowEst(pIndex);
  if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);

  if( pTab==pParse->pNewTable ){
    /* This routine has been called to create an automatic index as a
................................................................................
    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);
    if( pWInfo==0 ) goto delete_from_cleanup;
    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    assert( IsVirtual(pTab)==0 || eOnePass==ONEPASS_OFF );
    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
  
    /* Keep track of the number of rows to be deleted */
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
  
    /* Extract the rowid or primary key for the current row */
    if( pPk ){
      for(i=0; i<nPk; i++){
        assert( pPk->aiColumn[i]>=(-1) );
        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
                                        pPk->aiColumn[i], iPk+i);
      }
      iKey = iPk;
    }else{
      iKey = pParse->nMem + 1;
      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
................................................................................
    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
    */
    if( eOnePass!=ONEPASS_OFF ){
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
      if( aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 || pTab->pSelect!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
................................................................................
    /* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      sqlite3VtabMakeWritable(pParse, pTab);
      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, OE_Abort);

      sqlite3MayAbort(pParse);



    }else
#endif
    {
      int count = (pParse->nested==0);    /* True to count changes */
      int iIdxNoSeek = -1;
      if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
        iIdxNoSeek = aiCurOnePass[1];
................................................................................
  }
  nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
  regBase = sqlite3GetTempRange(pParse, nCol);
  if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
  for(j=0; j<nCol; j++){
    if( pPrior
     && pPrior->aiColumn[j]==pIdx->aiColumn[j]
     && pPrior->aiColumn[j]>=(-1)
    ){
      /* This column was already computed by the previous index */
      continue;
    }
    sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
    /* If the column affinity is REAL but the number is an integer, then it
    ** might be stored in the table as an integer (using a compact
................................................................................
        ** the default collation sequences for each column. */
        int i, j;
        for(i=0; i<nCol; i++){
          i16 iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
          char *zDfltColl;                  /* Def. collation for column */
          char *zIdxCol;                    /* Name of indexed column */



          /* If the index uses a collation sequence that is different from
          ** the default collation sequence for the column, this index is
          ** unusable. Bail out early in this case.  */
          zDfltColl = pParent->aCol[iCol].zColl;
          if( !zDfltColl ){
            zDfltColl = "BINARY";
          }
................................................................................
      ** none of the child key values are).
      */
      if( pTab==pFKey->pFrom && nIncr==1 ){
        int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;
        for(i=0; i<nCol; i++){
          int iChild = aiCol[i]+1+regData;
          int iParent = pIdx->aiColumn[i]+1+regData;

          assert( aiCol[i]!=pTab->iPKey );
          if( pIdx->aiColumn[i]==pTab->iPKey ){
            /* The parent key is a composite key that includes the IPK column */
            iParent = regData;
          }
          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
          sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
................................................................................
      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
    }else{
      Expr *pEq, *pAll = 0;
      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
      assert( pIdx!=0 );
      for(i=0; i<pPk->nKeyCol; i++){
        i16 iCol = pIdx->aiColumn[i];

        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
        pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, iCol);
        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
        pAll = sqlite3ExprAnd(db, pAll, pEq);
      }
      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0, 0);
    }
................................................................................
      iCol = pFKey->aCol[0].iFrom;
      aiCol = &iCol;
    }
    for(i=0; i<pFKey->nCol; i++){
      if( aiCol[i]==pTab->iPKey ){
        aiCol[i] = -1;
      }

#ifndef SQLITE_OMIT_AUTHORIZATION
      /* Request permission to read the parent key columns. If the 
      ** authorization callback returns SQLITE_IGNORE, behave as if any
      ** values read from the parent table are NULL. */
      if( db->xAuth ){
        int rcauth;
        char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
................................................................................
    for(p=pTab->pFKey; p; p=p->pNextFrom){
      for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
    }
    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
      Index *pIdx = 0;
      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
      if( pIdx ){


        for(i=0; i<pIdx->nKeyCol; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);

      }
    }
  }
  return mask;
}


................................................................................
      Token tToCol;               /* Name of column in parent table */
      int iFromCol;               /* Idx of column in child table */
      Expr *pEq;                  /* tFromCol = OLD.tToCol */

      iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
      assert( iFromCol>=0 );
      assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );

      tToCol.z = pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName;
      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;

      tToCol.n = sqlite3Strlen30(tToCol.z);
      tFromCol.n = sqlite3Strlen30(tFromCol.z);

      /* Create the expression "OLD.zToCol = zFromCol". It is important
................................................................................
      db->mallocFailed = 1;
      return 0;
    }
    for(n=0; n<pIdx->nColumn; n++){
      i16 x = pIdx->aiColumn[n];
      if( x>=0 ){
        pIdx->zColAff[n] = pTab->aCol[x].affinity;
      }else if( x==(-1) ){
        pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
      }else{
        char aff;
        assert( x==(-2) );
        assert( pIdx->aColExpr!=0 );
        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
        if( aff==0 ) aff = SQLITE_AFF_BLOB;
        pIdx->zColAff[n] = aff;
      }
    }
    pIdx->zColAff[n] = 0;
................................................................................
  int memId;                 /* Register holding max rowid */
  int addr;                  /* A VDBE address */
  Vdbe *v = pParse->pVdbe;   /* VDBE under construction */

  /* This routine is never called during trigger-generation.  It is
  ** only called from the top-level */
  assert( pParse->pTriggerTab==0 );
  assert( pParse==sqlite3ParseToplevel(pParse) );

  assert( v );   /* We failed long ago if this is not so */
  for(p = pParse->pAinc; p; p = p->pNext){
    pDb = &db->aDb[p->iDb];
    memId = p->regCtr;
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
................................................................................
    /* Create a record for this index entry as it should appear after
    ** the insert or update.  Store that record in the aRegIdx[ix] register
    */
    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField==(-2) ){
        pParse->ckBase = regNewData+1;
        sqlite3ExprCode(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
        pParse->ckBase = 0;
        VdbeComment((v, "%s column %d", pIdx->zName, i));
      }else{
        if( iField==(-1) || iField==pTab->iPKey ){
          if( regRowid==regIdx+i ) continue; /* ROWID already in regIdx+i */
          x = regNewData;
          regRowid =  pIdx->pPartIdxWhere ? -1 : regIdx+i;
        }else{
          x = iField + regNewData + 1;
        }
        sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
................................................................................
        }
      }else{
        int x;
        /* Extract the PRIMARY KEY from the end of the index entry and
        ** store it in registers regR..regR+nPk-1 */
        if( pIdx!=pPk ){
          for(i=0; i<pPk->nKeyCol; i++){

            x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
            sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
            VdbeComment((v, "%s.%s", pTab->zName,
                         pTab->aCol[pPk->aiColumn[i]].zName));
          }
        }
        if( isUpdate ){
................................................................................
          int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
          int op = OP_Ne;
          int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
  
          for(i=0; i<pPk->nKeyCol; i++){
            char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
            x = pPk->aiColumn[i];

            if( i==(pPk->nKeyCol-1) ){
              addrJump = addrUniqueOk;
              op = OP_Eq;
            }
            sqlite3VdbeAddOp4(v, op, 
                regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
            );
................................................................................
  if( pDest->onError!=pSrc->onError ){
    return 0;   /* Different conflict resolution strategies */
  }
  for(i=0; i<pSrc->nKeyCol; i++){
    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
      return 0;   /* Different columns indexed */
    }
    if( pSrc->aiColumn[i]==(-2) ){
      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
      if( sqlite3ExprCompare(pSrc->aColExpr->a[i].pExpr,
                             pDest->aColExpr->a[i].pExpr, -1)!=0 ){
        return 0;   /* Different expressions in the index */
      }
    }
    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
................................................................................

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList endCode[] = {
      { OP_IfNeg,       1, 0,        0},    /* 0 */

      { OP_String8,     0, 3,        0},    /* 1 */
      { OP_ResultRow,   3, 1,        0},
    };

    int isQuick = (sqlite3Tolower(zLeft[0])=='q');

    /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
    ** then iDb is set to the index of the database identified by <db>.
................................................................................
          ** or (2) the next entry has a different key */
          if( IsUniqueIndex(pIdx) ){
            int uniqOk = sqlite3VdbeMakeLabel(v);
            int jmp6;
            int kk;
            for(kk=0; kk<pIdx->nKeyCol; kk++){
              int iCol = pIdx->aiColumn[kk];
              assert( iCol!=(-1) && iCol<pTab->nCol );
              if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
              sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
              VdbeCoverage(v);
            }
            jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
            sqlite3VdbeGoto(v, uniqOk);
            sqlite3VdbeJumpHere(v, jmp6);
................................................................................
          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
        }
#endif /* SQLITE_OMIT_BTREECOUNT */
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
    sqlite3VdbeChangeP3(v, addr, -mxErr);
    sqlite3VdbeJumpHere(v, addr);
    sqlite3VdbeChangeP4(v, addr+1, "ok", P4_STATIC);
  }
  break;
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
................................................................................
    int addr;
    int iLimit;
    if( pSelect->iOffset ){
      iLimit = pSelect->iOffset+1;
    }else{
      iLimit = pSelect->iLimit;
    }
    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, -1); VdbeCoverage(v);
    sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
    sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
................................................................................
*/
static void codeOffset(
  Vdbe *v,          /* Generate code into this VM */
  int iOffset,      /* Register holding the offset counter */
  int iContinue     /* Jump here to skip the current record */
){
  if( iOffset>0 ){
    int addr;
    addr = sqlite3VdbeAddOp3(v, OP_IfNeg, iOffset, 0, -1); VdbeCoverage(v);
    sqlite3VdbeGoto(v, iContinue);
    VdbeComment((v, "skip OFFSET records"));
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Add code that will check to make sure the N registers starting at iMem
** form a distinct entry.  iTab is a sorting index that holds previously
** seen combinations of the N values.  A new entry is made in iTab
................................................................................
** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
  Vdbe *v = 0;
  int iLimit = 0;
  int iOffset;
  int addr1, n;
  if( p->iLimit ) return;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** controversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
................................................................................
    }
    if( p->pOffset ){
      p->iOffset = iOffset = ++pParse->nMem;
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
      sqlite3ExprCode(pParse, p->pOffset, iOffset);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
      VdbeComment((v, "OFFSET counter"));
      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset);
      sqlite3VdbeJumpHere(v, addr1);
      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
      VdbeComment((v, "LIMIT+OFFSET"));
      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1);
      sqlite3VdbeJumpHere(v, addr1);

    }
  }
}

#ifndef SQLITE_OMIT_COMPOUND_SELECT
/*
** Return the appropriate collating sequence for the iCol-th column of
................................................................................
      }
      p->pPrior = 0;
      p->iLimit = pPrior->iLimit;
      p->iOffset = pPrior->iOffset;
      if( p->iLimit ){
        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
        VdbeComment((v, "Jump ahead if LIMIT reached"));





      }
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &dest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      p->nSelectRow += pPrior->nSelectRow;
................................................................................

  /* Look up every table named in the FROM clause of the select.  If
  ** an entry of the FROM clause is a subquery instead of a table or view,
  ** then create a transient table structure to describe the subquery.
  */
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab;
    assert( pFrom->fg.isRecursive==0 || pFrom->pTab );
    if( pFrom->fg.isRecursive ) continue;
    if( pFrom->pTab!=0 ){
      /* This statement has already been prepared.  There is no need
      ** to go further. */
      assert( i==0 );
#ifndef SQLITE_OMIT_CTE
      selectPopWith(pWalker, p);
#endif
      return WRC_Prune;
    }
#ifndef SQLITE_OMIT_CTE
    if( withExpand(pWalker, pFrom) ) return WRC_Abort;
    if( pFrom->pTab ) {} else
#endif
    if( pFrom->zName==0 ){
#ifndef SQLITE_OMIT_SUBQUERY
      Select *pSel = pFrom->pSelect;
................................................................................
static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
  Parse *pParse;
  int i;
  SrcList *pTabList;
  struct SrcList_item *pFrom;

  assert( p->selFlags & SF_Resolved );
  if( (p->selFlags & SF_HasTypeInfo)==0 ){
    p->selFlags |= SF_HasTypeInfo;
    pParse = pWalker->pParse;
    pTabList = p->pSrc;
    for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
      Table *pTab = pFrom->pTab;

      if( ALWAYS(pTab!=0) && (pTab->tabFlags & TF_Ephemeral)!=0 ){
        /* A sub-query in the FROM clause of a SELECT */
        Select *pSel = pFrom->pSelect;
        if( pSel ){
          while( pSel->pPrior ) pSel = pSel->pPrior;
          selectAddColumnTypeAndCollation(pParse, pTab, pSel);
        }
      }
    }
  }
}
#endif


................................................................................
  int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */
  int iEph = 0;          /* Ephemeral table holding all primary key values */
  int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */

  /* Register Allocations */
  int regRowCount = 0;   /* A count of rows changed */
  int regOldRowid;       /* The old rowid */
  int regNewRowid;       /* The new rowid */
  int regNew;            /* Content of the NEW.* table in triggers */
  int regOld = 0;        /* Content of OLD.* table in triggers */
  int regRowSet = 0;     /* Rowset of rows to be updated */
  int regKey = 0;        /* composite PRIMARY KEY value */

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
................................................................................

  /* Begin generating code. */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto update_cleanup;
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
  /* Virtual tables must be handled separately */
  if( IsVirtual(pTab) ){
    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
                       pWhere, onError);
    pWhere = 0;
    pTabList = 0;
    goto update_cleanup;
  }
#endif

  /* Allocate required registers. */

  regRowSet = ++pParse->nMem;
  regOldRowid = regNewRowid = ++pParse->nMem;
  if( chngPk || pTrigger || hasFK ){
    regOld = pParse->nMem + 1;
    pParse->nMem += pTab->nCol;
  }
  if( chngKey || pTrigger || hasFK ){
    regNewRowid = ++pParse->nMem;
  }
  regNew = pParse->nMem + 1;
  pParse->nMem += pTab->nCol;


  /* Start the view context. */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

  /* If we are trying to update a view, realize that view into
................................................................................

  /* Resolve the column names in all the expressions in the
  ** WHERE clause.
  */
  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
    goto update_cleanup;
  }










  /* Begin the database scan
  */
  if( HasRowid(pTab) ){
    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
    pWInfo = sqlite3WhereBegin(
        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
................................................................................
    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
                               WHERE_ONEPASS_DESIRED, iIdxCur);
    if( pWInfo==0 ) goto update_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    for(i=0; i<nPk; i++){
      assert( pPk->aiColumn[i]>=(-1) );
      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
                                      iPk+i);
    }
    if( okOnePass ){
      sqlite3VdbeChangeToNoop(v, addrOpen);
      nKey = nPk;
      regKey = iPk;
................................................................................
  ** the database after the BEFORE triggers are fired anyway (as the trigger 
  ** may have modified them). So not loading those that are not going to
  ** be used eliminates some redundant opcodes.
  */
  newmask = sqlite3TriggerColmask(
      pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
  );
  /*sqlite3VdbeAddOp3(v, OP_Null, 0, regNew, regNew+pTab->nCol-1);*/
  for(i=0; i<pTab->nCol; i++){
    if( i==pTab->iPKey ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
    }else{
      j = aXRef[i];
      if( j>=0 ){
        sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
................................................................................
 #undef pTrigger
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Generate code for an UPDATE of a virtual table.
**




** The strategy is that we create an ephemeral table that contains
** for each row to be changed:
**
**   (A)  The original rowid of that row.
**   (B)  The revised rowid for the row. (note1)
**   (C)  The content of every column in the row.
**
** Then we loop over this ephemeral table and for each row in
** the ephemeral table call VUpdate.
**
** When finished, drop the ephemeral table.
**


** (note1) Actually, if we know in advance that (A) is always the same
** as (B) we only store (A), then duplicate (A) when pulling
** it out of the ephemeral table before calling VUpdate.
*/
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
  SrcList *pSrc,       /* The virtual table to be modified */
  Table *pTab,         /* The virtual table */
  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
  Expr *pRowid,        /* Expression used to recompute the rowid */
  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
  int onError          /* ON CONFLICT strategy */
){
  Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */
  ExprList *pEList = 0;     /* The result set of the SELECT statement */
  Select *pSelect = 0;      /* The SELECT statement */
  Expr *pExpr;              /* Temporary expression */
  int ephemTab;             /* Table holding the result of the SELECT */
  int i;                    /* Loop counter */
  int addr;                 /* Address of top of loop */
  int iReg;                 /* First register in set passed to OP_VUpdate */
  sqlite3 *db = pParse->db; /* Database connection */
  const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);





  SelectDest dest;




  /* Construct the SELECT statement that will find the new values for
  ** all updated rows. 
  */
  pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_"));
















  if( pRowid ){
    pEList = sqlite3ExprListAppend(pParse, pEList,
                                   sqlite3ExprDup(db, pRowid, 0));



  }
  assert( pTab->iPKey<0 );
  for(i=0; i<pTab->nCol; i++){
    if( aXRef[i]>=0 ){
      pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0);
    }else{
      pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName);

    }
    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr);
  }
  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
  
  /* Create the ephemeral table into which the update results will
  ** be stored.
  */
  assert( v );
  ephemTab = pParse->nTab++;


  /* fill the ephemeral table 
  */
  sqlite3SelectDestInit(&dest, SRT_EphemTab, ephemTab);
  sqlite3Select(pParse, pSelect, &dest);










  /* Generate code to scan the ephemeral table and call VUpdate. */
  iReg = ++pParse->nMem;
  pParse->nMem += pTab->nCol+1;

  addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0); VdbeCoverage(v);
  sqlite3VdbeAddOp3(v, OP_Column,  ephemTab, 0, iReg);
  sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1);












  for(i=0; i<pTab->nCol; i++){
    sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i);
  }

  sqlite3VtabMakeWritable(pParse, pTab);
  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB);
  sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
  sqlite3MayAbort(pParse);




  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
  sqlite3VdbeJumpHere(v, addr);
  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);



  /* Cleanup */
  sqlite3SelectDelete(db, pSelect);  
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/************** End of update.c **********************************************/
/************** Begin file vacuum.c ******************************************/
/*
** 2003 April 6
................................................................................

    /* Invoke the xBegin method. If successful, add the vtab to the 
    ** sqlite3.aVTrans[] array. */
    rc = growVTrans(db);
    if( rc==SQLITE_OK ){
      rc = pModule->xBegin(pVTab->pVtab);
      if( rc==SQLITE_OK ){

        addToVTrans(db, pVTab);

      }
    }
  }
  return rc;
}

/*
................................................................................
}

/*
** 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==(-2) ) return "<expr>";
  if( i==(-1) ) return "rowid";
  return pIdx->pTable->aCol[i].zName;
}

/*
** 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.
................................................................................
    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
                            iIdxCur, 0, regBase, nSkip);
    VdbeCoverageIf(v, bRev==0);
    VdbeCoverageIf(v, bRev!=0);
    sqlite3VdbeJumpHere(v, j);
    for(j=0; j<nSkip; j++){
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
      testcase( pIdx->aiColumn[j]==(-2) );
      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
    }
  }    

  /* Evaluate the equality constraints
  */
  assert( zAff==0 || (int)strlen(zAff)>=nEq );
................................................................................
    VdbeCoverage(v);
    pLoop->u.vtab.needFree = 0;
    for(j=0; j<nConstraint && j<16; j++){
      if( (pLoop->u.vtab.omitMask>>j)&1 ){
        disableTerm(pLevel, pLoop->aLTerm[j]);
      }
    }
    pLevel->op = OP_VNext;
    pLevel->p1 = iCur;

    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
    sqlite3ExprCachePop(pParse);
  }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  if( (pLoop->wsFlags & WHERE_IPK)!=0
................................................................................
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);







  return pWInfo->eOnePass;
}

/*
** Move the content of pSrc into pDest
*/
static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
................................................................................
  WhereClause *pWC;    /* Shorthand for pScan->pWC */
  WhereTerm *pTerm;    /* The term being tested */
  int k = pScan->k;    /* Where to start scanning */

  while( pScan->iEquiv<=pScan->nEquiv ){
    iCur = pScan->aiCur[pScan->iEquiv-1];
    iColumn = pScan->aiColumn[pScan->iEquiv-1];
    if( iColumn==(-2) && pScan->pIdxExpr==0 ) return 0;
    while( (pWC = pScan->pWC)!=0 ){
      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
        if( pTerm->leftCursor==iCur
         && pTerm->u.leftColumn==iColumn
         && (iColumn!=(-2)
             || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
        ){
          if( (pTerm->eOperator & WO_EQUIV)!=0
           && pScan->nEquiv<ArraySize(pScan->aiCur)
           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
          ){
................................................................................
  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  if( pIdx ){
    j = iColumn;
    iColumn = pIdx->aiColumn[j];
    if( iColumn==(-2) ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
  }
  if( pIdx && iColumn>=0 ){
    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
    pScan->zCollName = pIdx->azColl[j];
  }else{
    pScan->idxaff = 0;
    pScan->zCollName = 0;
................................................................................
    for(i=BMS-1; i<pTable->nCol; i++){
      pIdx->aiColumn[n] = i;
      pIdx->azColl[n] = "BINARY";
      n++;
    }
  }
  assert( n==nKeyCol );
  pIdx->aiColumn[n] = -1;
  pIdx->azColl[n] = "BINARY";

  /* Create the automatic index */
  assert( pLevel->iIdxCur>=0 );
  pLevel->iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
................................................................................
      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==(-1) || (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 ){
................................................................................
    if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
      if( pExpr->iColumn<0 ) return 1;
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
      }
    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pIndex->aiColumn[jj]!=(-2) ) continue;
        if( sqlite3ExprCompare(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
          return 1;
        }
      }
    }
  }
  return 0;
................................................................................
    if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
    pIdxInfo->idxStr = 0;
    pIdxInfo->idxNum = 0;
    pIdxInfo->needToFreeIdxStr = 0;
    pIdxInfo->orderByConsumed = 0;
    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
    pIdxInfo->estimatedRows = 25;

    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
    if( rc ) goto whereLoopAddVtab_exit;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    pNew->prereq = mExtra;
    mxTerm = -1;
    assert( pNew->nLSlot>=nConstraint );
    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
................................................................................
          }
          /* A virtual table that is constrained by an IN clause may not
          ** consume the ORDER BY clause because (1) the order of IN terms
          ** is not necessarily related to the order of output terms and
          ** (2) Multiple outputs from a single IN value will not merge
          ** together.  */
          pIdxInfo->orderByConsumed = 0;

        }
      }
    }
    if( i>=nConstraint ){
      pNew->nLTerm = mxTerm+1;
      assert( pNew->nLTerm<=pNew->nLSlot );
      pNew->u.vtab.idxNum = pIdxInfo->idxNum;
................................................................................
      pIdxInfo->needToFreeIdxStr = 0;
      pNew->u.vtab.idxStr = pIdxInfo->idxStr;
      pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
                                      pIdxInfo->nOrderBy : 0);
      pNew->rSetup = 0;
      pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
      pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);








      whereLoopInsert(pBuilder, pNew);
      if( pNew->u.vtab.needFree ){
        sqlite3_free(pNew->u.vtab.idxStr);
        pNew->u.vtab.needFree = 0;
      }
    }
  }  
................................................................................
        nColumn = 1;
      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
        return 0;
      }else{
        nKeyCol = pIndex->nKeyCol;
        nColumn = pIndex->nColumn;
        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
        assert( pIndex->aiColumn[nColumn-1]==(-1) || !HasRowid(pIndex->pTable));

        isOrderDistinct = IsUniqueIndex(pIndex);
      }

      /* Loop through all columns of the index and deal with the ones
      ** that are not constrained by == or IN.
      */
      rev = revSet = 0;
................................................................................
        ** (revIdx) for the j-th column of the index.
        */
        if( pIndex ){
          iColumn = pIndex->aiColumn[j];
          revIdx = pIndex->aSortOrder[j];
          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
        }else{
          iColumn = -1;
          revIdx = 0;
        }

        /* An unconstrained column that might be NULL means that this
        ** WhereLoop is not well-ordered
        */
        if( isOrderDistinct
................................................................................
      /* Try to ORDER BY the result set to make distinct processing easier */
      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
      pWInfo->pOrderBy = pResultSet;
    }
  }

  /* Construct the WhereLoop objects */
  WHERETRACE(0xffff,("*** Optimizer Start ***\n"));

#if defined(WHERETRACE_ENABLED)
  if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */
    int i;
    for(i=0; i<sWLB.pWC->nTerm; i++){
      whereTermPrint(&sWLB.pWC->a[i], i);
    }
  }
................................................................................
        if( pOp->p1!=pLevel->iTabCur ) continue;
        if( pOp->opcode==OP_Column ){
          int x = pOp->p2;
          assert( pIdx->pTable==pTab );
          if( !HasRowid(pTab) ){
            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
            x = pPk->aiColumn[x];

          }
          x = sqlite3ColumnOfIndex(pIdx, x);
          if( x>=0 ){
            pOp->p2 = x;
            pOp->p1 = pLevel->iIdxCur;
          }
          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 );
................................................................................
    int nPrefix;                  /* Prefix length (0 for main terms index) */
    Fts3Hash hPending;            /* Pending terms table for this index */
  } *aIndex;
  int nMaxPendingData;            /* Max pending data before flush to disk */
  int nPendingData;               /* Current bytes of pending data */
  sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */
  int iPrevLangid;                /* Langid of recently inserted document */


#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  /* State variables used for validating that the transaction control
  ** methods of the virtual table are called at appropriate times.  These
  ** values do not contribute to FTS functionality; they are used for
  ** verifying the operation of the SQLite core.
  */
................................................................................
static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
#if SQLITE_VERSION_NUMBER>=3008002
  if( sqlite3_libversion_number()>=3008002 ){
    pIdxInfo->estimatedRows = nRow;
  }
#endif
}














/* 
** Implementation of the xBestIndex method for FTS3 tables. There
** are three possible strategies, in order of preference:
**
**   1. Direct lookup by rowid or docid. 
**   2. Full-text search using a MATCH operator on a non-docid column.
................................................................................
        case SQLITE_INDEX_CONSTRAINT_LE:
        case SQLITE_INDEX_CONSTRAINT_LT:
          iDocidLe = i;
          break;
      }
    }
  }




  iIdx = 1;
  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
  if( iLangidCons>=0 ){
................................................................................
  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
  int eType = pRoot->eType;       /* Type of node in this tree */

  if( nMaxDepth==0 ){
    rc = SQLITE_ERROR;
  }


  if( rc==SQLITE_OK && (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
    Fts3Expr **apLeaf;
    apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
    if( 0==apLeaf ){
      rc = SQLITE_NOMEM;
    }else{
      memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
    }

    if( rc==SQLITE_OK ){
      int i;
      Fts3Expr *p;

      /* Set $p to point to the left-most leaf in the tree of eType nodes. */
      for(p=pRoot; p->eType==eType; p=p->pLeft){
        assert( p->pParent==0 || p->pParent->pLeft==p );
        assert( p->pLeft && p->pRight );
      }

      /* This loop runs once for each leaf in the tree of eType nodes. */
      while( 1 ){
        int iLvl;
        Fts3Expr *pParent = p->pParent;     /* Current parent of p */

        assert( pParent==0 || pParent->pLeft==p );
        p->pParent = 0;
        if( pParent ){
          pParent->pLeft = 0;
        }else{
          pRoot = 0;
        }
        rc = fts3ExprBalance(&p, nMaxDepth-1);
        if( rc!=SQLITE_OK ) break;

        for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){
          if( apLeaf[iLvl]==0 ){
            apLeaf[iLvl] = p;
            p = 0;
          }else{
            assert( pFree );
            pFree->pLeft = apLeaf[iLvl];
            pFree->pRight = p;
            pFree->pLeft->pParent = pFree;
            pFree->pRight->pParent = pFree;

            p = pFree;
            pFree = pFree->pParent;
            p->pParent = 0;
            apLeaf[iLvl] = 0;
          }
        }
        if( p ){
          sqlite3Fts3ExprFree(p);
          rc = SQLITE_TOOBIG;
          break;
        }

        /* If that was the last leaf node, break out of the loop */
        if( pParent==0 ) break;

        /* Set $p to point to the next leaf in the tree of eType nodes */
        for(p=pParent->pRight; p->eType==eType; p=p->pLeft);

        /* Remove pParent from the original tree. */
        assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
        pParent->pRight->pParent = pParent->pParent;
        if( pParent->pParent ){
          pParent->pParent->pLeft = pParent->pRight;
        }else{
          assert( pParent==pRoot );
          pRoot = pParent->pRight;
        }

        /* Link pParent into the free node list. It will be used as an
        ** internal node of the new tree.  */
        pParent->pParent = pFree;
        pFree = pParent;
      }

      if( rc==SQLITE_OK ){
        p = 0;
        for(i=0; i<nMaxDepth; i++){
          if( apLeaf[i] ){
            if( p==0 ){
              p = apLeaf[i];
              p->pParent = 0;
            }else{
              assert( pFree!=0 );
              pFree->pRight = p;
              pFree->pLeft = apLeaf[i];
              pFree->pLeft->pParent = pFree;
              pFree->pRight->pParent = pFree;

              p = pFree;
              pFree = pFree->pParent;
              p->pParent = 0;
            }
          }
        }
        pRoot = p;
      }else{
        /* An error occurred. Delete the contents of the apLeaf[] array 
        ** and pFree list. Everything else is cleaned up by the call to
        ** sqlite3Fts3ExprFree(pRoot) below.  */
        Fts3Expr *pDel;
        for(i=0; i<nMaxDepth; i++){
          sqlite3Fts3ExprFree(apLeaf[i]);
        }
        while( (pDel=pFree)!=0 ){
          pFree = pDel->pParent;
          sqlite3_free(pDel);
        }
      }

      assert( pFree==0 );
      sqlite3_free( apLeaf );
    }



  }























  if( rc!=SQLITE_OK ){
    sqlite3Fts3ExprFree(pRoot);
    pRoot = 0;
  }
  *pp = pRoot;
  return rc;
}
................................................................................
/* 
** Calling this function indicates that subsequent calls to 
** fts3PendingTermsAdd() are to add term/position-list pairs for the
** contents of the document with docid iDocid.
*/
static int fts3PendingTermsDocid(
  Fts3Table *p,                   /* Full-text table handle */

  int iLangid,                    /* Language id of row being written */
  sqlite_int64 iDocid             /* Docid of row being written */
){
  assert( iLangid>=0 );


  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */
  if( iDocid<=p->iPrevDocid 

   || p->iPrevLangid!=iLangid
   || p->nPendingData>p->nMaxPendingData 
  ){
    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  p->iPrevLangid = iLangid;

  return SQLITE_OK;
}

/*
** Discard the contents of the pending-terms hash tables. 
*/
SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *p){
................................................................................
  assert( *pbFound==0 );
  if( *pRC ) return;
  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
  if( rc==SQLITE_OK ){
    if( SQLITE_ROW==sqlite3_step(pSelect) ){
      int i;
      int iLangid = langidFromSelect(p, pSelect);
      rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pSelect, 0));

      for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
        int iCol = i-1;
        if( p->abNotindexed[iCol]==0 ){
          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
        }
................................................................................
    pNext = &pReader->aDoclist[pReader->nDoclist];
  }

  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){

    if( fts3SegReaderIsPending(pReader) ){
      Fts3HashElem *pElem = *(pReader->ppNextElem);
      if( pElem==0 ){
        pReader->aNode = 0;
      }else{

        PendingList *pList = (PendingList *)fts3HashData(pElem);

        pReader->zTerm = (char *)fts3HashKey(pElem);
        pReader->nTerm = fts3HashKeysize(pElem);



        pReader->nNode = pReader->nDoclist = pList->nData + 1;
        pReader->aNode = pReader->aDoclist = pList->aData;
        pReader->ppNextElem++;
        assert( pReader->aNode );
      }
      return SQLITE_OK;
    }

    fts3SegReaderSetEof(pReader);
................................................................................
}

/*
** Free all allocations associated with the iterator passed as the 
** second argument.
*/
SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){

  if( pReader && !fts3SegReaderIsPending(pReader) ){
    sqlite3_free(pReader->zTerm);

    if( !fts3SegReaderIsRootOnly(pReader) ){
      sqlite3_free(pReader->aNode);
      sqlite3_blob_close(pReader->pBlob);
    }

  }
  sqlite3_free(pReader);
}

/*
** Allocate a new SegReader object.
*/
................................................................................
        aSzDel = &aSzIns[p->nColumn+1];
      }
    }

    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int iCol;
      int iLangid = langidFromSelect(p, pStmt);
      rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pStmt, 0));
      memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
        if( p->abNotindexed[iCol]==0 ){
          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
        }
................................................................................
    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
      rc = fts3PendingTermsDocid(p, iLangid, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
    }
    if( p->bHasDocsize ){
      fts3InsertDocsize(&rc, p, aSzIns);

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.12"
#define SQLITE_VERSION_NUMBER 3008012
#define SQLITE_SOURCE_ID      "2015-10-07 17:06:17 13adcd038fc20dd1b6f344f79b449b4034f8f8f2"

/*
** 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
................................................................................
** strategy. A cost of N indicates that the cost of the strategy is similar
** to a linear scan of an SQLite table with N rows. A cost of log(N) 
** indicates that the expense of the operation is similar to that of a
** binary search on a unique indexed field of an SQLite table with N rows.
**
** ^The estimatedRows value is an estimate of the number of rows that
** will be returned by the strategy.
**
** The xBestIndex method may optionally populate the idxFlags field with a 
** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
** assumes that the strategy may visit at most one row. 
**
** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
** SQLite also assumes that if a call to the xUpdate() method is made as
** part of the same statement to delete or update a virtual table row and the
** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
** any database changes. In other words, if the xUpdate() returns
** SQLITE_CONSTRAINT, the database contents must be exactly as they were
** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
** the xUpdate method are automatically rolled back by SQLite.
**
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
** structure for SQLite version 3.8.2. If a virtual table extension is
** used with an SQLite version earlier than 3.8.2, the results of attempting 
** to read or write the estimatedRows field are undefined (but are likely 
** to included crashing the application). The estimatedRows field should
** therefore only be used if [sqlite3_libversion_number()] returns a
** value greater than or equal to 3008002. Similarly, the idxFlags field
** was added for version 3.8.12. It may therefore only be used if
** sqlite3_libversion_number() returns a value greater than or equal to
** 3008012.
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
................................................................................
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
  /* Fields below are only available in SQLite 3.8.12 and later */
  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
};

/*
** CAPI3REF: Virtual Table Scan Flags
*/
#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the wHERE clause of
** a query that uses a [virtual table].
................................................................................
*/
#if !defined(SQLITE_DISABLE_INTRINSIC)
#  if defined(_MSC_VER) && _MSC_VER>=1300
#    if !defined(_WIN32_WCE)
#      include <intrin.h>
#      pragma intrinsic(_byteswap_ushort)
#      pragma intrinsic(_byteswap_ulong)
#      pragma intrinsic(_ReadWriteBarrier)
#    else
#      include <cmnintrin.h>
#    endif
#  endif
#endif

/*
................................................................................
#define OP_RowSetTest    131 /* synopsis: if r[P3] in rowset(P1) goto P2   */
#define OP_Program       132
#define OP_Real          133 /* same as TK_FLOAT, synopsis: r[P2]=P4       */
#define OP_Param         134
#define OP_FkCounter     135 /* synopsis: fkctr[P1]+=P2                    */
#define OP_FkIfZero      136 /* synopsis: if fkctr[P1]==0 goto P2          */
#define OP_MemMax        137 /* synopsis: r[P1]=max(r[P1],r[P2])           */
#define OP_IfPos         138 /* synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */
#define OP_SetIfNotPos   139 /* synopsis: if r[P1]<=0 then r[P2]=P3        */
#define OP_IfNotZero     140 /* synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2 */
#define OP_DecrJumpZero  141 /* synopsis: if (--r[P1])==0 goto P2          */
#define OP_JumpZeroIncr  142 /* synopsis: if (r[P1]++)==0 ) goto P2        */
#define OP_AggStep0      143 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggStep       144 /* synopsis: accum=r[P3] step(r[P2@P5])       */
#define OP_AggFinal      145 /* synopsis: accum=r[P1] N=P2                 */
#define OP_IncrVacuum    146
#define OP_Expire        147
................................................................................
/*  80 */ 0x0b, 0x0b, 0x0b, 0x0b, 0x00, 0x26, 0x26, 0x26,\
/*  88 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x00,\
/*  96 */ 0x12, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 104 */ 0x10, 0x00, 0x01, 0x01, 0x01, 0x01, 0x04, 0x04,\
/* 112 */ 0x00, 0x10, 0x01, 0x01, 0x01, 0x01, 0x10, 0x00,\
/* 120 */ 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 128 */ 0x00, 0x06, 0x23, 0x0b, 0x01, 0x10, 0x10, 0x00,\
/* 136 */ 0x01, 0x04, 0x03, 0x06, 0x03, 0x03, 0x03, 0x00,\
/* 144 */ 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,\
/* 152 */ 0x00, 0x00, 0x01, 0x00, 0x10, 0x10, 0x01, 0x00,\
/* 160 */ 0x00,}

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

................................................................................

/* Return true if index X is a PRIMARY KEY index */
#define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)

/* Return true if index X is a UNIQUE index */
#define IsUniqueIndex(X)      ((X)->onError!=OE_None)

/* The Index.aiColumn[] values are normally positive integer.  But
** there are some negative values that have special meaning:
*/
#define XN_ROWID     (-1)     /* Indexed column is the rowid */
#define XN_EXPR      (-2)     /* Indexed column is an expression */

/*
** Each sample stored in the sqlite_stat3 table is represented in memory 
** using a structure of this type.  See documentation at the top of the
** analyze.c source file for additional information.
*/
struct IndexSample {
  void *p;          /* Pointer to sampled record */
................................................................................
                                        Select*,u8);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
SQLITE_PRIVATE   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
SQLITE_PRIVATE   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
# define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
# define sqlite3IsToplevel(p) ((p)->pToplevel==0)
#else
# define sqlite3TriggersExist(B,C,D,E,F) 0
# define sqlite3DeleteTrigger(A,B)
# define sqlite3DropTriggerPtr(A,B)
# define sqlite3UnlinkAndDeleteTrigger(A,B,C)
# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
# define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
# define sqlite3TriggerList(X, Y) 0
# define sqlite3ParseToplevel(p) p
# define sqlite3IsToplevel(p) 1
# define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
#endif

SQLITE_PRIVATE int sqlite3JoinType(Parse*, Token*, Token*, Token*);
SQLITE_PRIVATE void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse*, int);
#ifndef SQLITE_OMIT_AUTHORIZATION
................................................................................
** compiled without mutexes (SQLITE_THREADSAFE=0).
*/
SQLITE_PRIVATE void sqlite3MemoryBarrier(void){
#if defined(SQLITE_MEMORY_BARRIER)
  SQLITE_MEMORY_BARRIER;
#elif defined(__GNUC__)
  __sync_synchronize();
#elif !defined(SQLITE_DISABLE_INTRINSIC) && \
      defined(_MSC_VER) && _MSC_VER>=1300
  _ReadWriteBarrier();
#elif defined(MemoryBarrier)
  MemoryBarrier();
#endif
}

/*
** Initialize and deinitialize the mutex subsystem.
*/
................................................................................
     /* 131 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),
     /* 132 */ "Program"          OpHelp(""),
     /* 133 */ "Real"             OpHelp("r[P2]=P4"),
     /* 134 */ "Param"            OpHelp(""),
     /* 135 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),
     /* 136 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),
     /* 137 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),
     /* 138 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),
     /* 139 */ "SetIfNotPos"      OpHelp("if r[P1]<=0 then r[P2]=P3"),
     /* 140 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]-=P3, goto P2"),
     /* 141 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),
     /* 142 */ "JumpZeroIncr"     OpHelp("if (r[P1]++)==0 ) goto P2"),
     /* 143 */ "AggStep0"         OpHelp("accum=r[P3] step(r[P2@P5])"),
     /* 144 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),
     /* 145 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),
     /* 146 */ "IncrVacuum"       OpHelp(""),
     /* 147 */ "Expire"           OpHelp(""),
................................................................................

  rc = saveCursorKey(pCur);
  if( rc==SQLITE_OK ){
    btreeReleaseAllCursorPages(pCur);
    pCur->eState = CURSOR_REQUIRESEEK;
  }

  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl|BTCF_AtLast);
  return rc;
}

/* Forward reference */
static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);

/*
................................................................................
    ** for which the pointer is stored within the content being copied.
    **
    ** It is critical that the child page be defragmented before being
    ** copied into the parent, because if the parent is page 1 then it will
    ** by smaller than the child due to the database header, and so all the
    ** free space needs to be up front.
    */
    assert( nNew==1 || CORRUPT_DB );
    rc = defragmentPage(apNew[0]);
    testcase( rc!=SQLITE_OK );
    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
      || rc!=SQLITE_OK
    );
    copyNodeContent(apNew[0], pParent, &rc);
................................................................................
  if( pIn1->u.i<pIn2->u.i){
    pIn1->u.i = pIn2->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfPos P1 P2 P3 * *
** Synopsis: if r[P1]>0 then r[P1]-=P3, goto P2
**
** Register P1 must contain an integer.
** If the value of register P1 is 1 or greater, subtract P3 from the
** value in P1 and jump to P2.
**
** If the initial value of register P1 is less than 1, then the
** value is unchanged and control passes through to the next instruction.
*/
case OP_IfPos: {        /* jump, in1 */
  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  VdbeBranchTaken( pIn1->u.i>0, 2);
  if( pIn1->u.i>0 ){
    pIn1->u.i -= pOp->p3;
    goto jump_to_p2;
  }
  break;
}

/* Opcode: SetIfNotPos P1 P2 P3 * *
** Synopsis: if r[P1]<=0 then r[P2]=P3
**
** Register P1 must contain an integer.
** If the value of register P1 is not positive (if it is less than 1) then
** set the value of register P2 to be the integer P3.
*/

case OP_SetIfNotPos: {        /* in1, in2 */
  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );


  if( pIn1->u.i<=0 ){
    pOut = out2Prerelease(p, pOp);
    pOut->u.i = pOp->p3;
  }
  break;
}

/* Opcode: IfNotZero P1 P2 P3 * *
** Synopsis: if r[P1]!=0 then r[P1]-=P3, goto P2
**
** Register P1 must contain an integer.  If the content of register P1 is
** initially nonzero, then subtract P3 from the value in register P1 and
** jump to P2.  If register P1 is initially zero, leave it unchanged
** and fall through.
*/
case OP_IfNotZero: {        /* jump, in1 */
  pIn1 = &aMem[pOp->p1];
  assert( pIn1->flags&MEM_Int );
  VdbeBranchTaken(pIn1->u.i<0, 2);
  if( pIn1->u.i ){
     pIn1->u.i -= pOp->p3;
     goto jump_to_p2;
  }
  break;
}

/* Opcode: DecrJumpZero P1 P2 * * *
** Synopsis: if (--r[P1])==0 goto P2
................................................................................
        }
      }
#endif
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nKeyCol; j++){
          /* FIXME: Be smarter about indexes that use expressions */
          if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==XN_EXPR ){
            zFault = "indexed";
          }
        }
      }
      if( zFault ){
        sqlite3DbFree(db, zErr);
        zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);
................................................................................
  Parse *pParse,  /* The parsing context */
  Index *pIdx,    /* The index whose column is to be loaded */
  int iTabCur,    /* Cursor pointing to a table row */
  int iIdxCol,    /* The column of the index to be loaded */
  int regOut      /* Store the index column value in this register */
){
  i16 iTabCol = pIdx->aiColumn[iIdxCol];
  if( iTabCol==XN_EXPR ){




    assert( pIdx->aColExpr );
    assert( pIdx->aColExpr->nExpr>iIdxCol );
    pParse->iSelfTab = iTabCur;
    sqlite3ExprCode(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
  }else{
    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
                                    iTabCol, regOut);
  }
}

/*
** Generate code to extract the value of the iCol-th column of a table.
*/
SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
  Vdbe *v,        /* The VDBE under construction */
................................................................................
          OP_Transaction,                    /* Opcode */
          iDb,                               /* P1 */
          DbMaskTest(pParse->writeMask,iDb), /* P2 */
          pParse->cookieValue[iDb],          /* P3 */
          db->aDb[iDb].pSchema->iGeneration  /* P4 */
        );
        if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
        VdbeComment((v,
              "usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      for(i=0; i<pParse->nVtabLock; i++){
        char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
        sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
      }
      pParse->nVtabLock = 0;
................................................................................
  }else{
    sortOrderMask = 0;    /* Ignore DESC */
  }

  /* Analyze the list of expressions that form the terms of the index and
  ** report any errors.  In the common case where the expression is exactly
  ** a table column, store that column in aiColumn[].  For general expressions,
  ** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].
  **
  ** TODO: Issue a warning if two or more columns of the index are identical.
  ** TODO: Issue a warning if the table primary key is used as part of the
  ** index key.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    Expr *pCExpr;                  /* The i-th index expression */
................................................................................
        ExprList *pCopy = sqlite3ExprListDup(db, pList, 0);
        pIndex->aColExpr = pCopy;
        if( !db->mallocFailed ){
          assert( pCopy!=0 );
          pListItem = &pCopy->a[i];
        }
      }
      j = XN_EXPR;
      pIndex->aiColumn[i] = XN_EXPR;
      pIndex->uniqNotNull = 0;
    }else{
      j = pCExpr->iColumn;
      assert( j<=0x7fff );
      if( j<0 ){
        j = pTab->iPKey;
      }else if( pTab->aCol[j].notNull==0 ){
................................................................................
        pIndex->azColl[i] = pPk->azColl[j];
        pIndex->aSortOrder[i] = pPk->aSortOrder[j];
        i++;
      }
    }
    assert( i==pIndex->nColumn );
  }else{
    pIndex->aiColumn[i] = XN_ROWID;
    pIndex->azColl[i] = "BINARY";
  }
  sqlite3DefaultRowEst(pIndex);
  if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);

  if( pTab==pParse->pNewTable ){
    /* This routine has been called to create an automatic index as a
................................................................................
    **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.
    **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.
    **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);
    if( pWInfo==0 ) goto delete_from_cleanup;
    eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
  
    /* Keep track of the number of rows to be deleted */
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
    }
  
    /* Extract the rowid or primary key for the current row */
    if( pPk ){
      for(i=0; i<nPk; i++){
        assert( pPk->aiColumn[i]>=0 );
        sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
                                        pPk->aiColumn[i], iPk+i);
      }
      iKey = iPk;
    }else{
      iKey = pParse->nMem + 1;
      iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
................................................................................
    }
  
    /* Set up a loop over the rowids/primary-keys that were found in the
    ** where-clause loop above.
    */
    if( eOnePass!=ONEPASS_OFF ){
      assert( nKey==nPk );  /* OP_Found will use an unpacked key */
      if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
        assert( pPk!=0 || pTab->pSelect!=0 );
        sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
        VdbeCoverage(v);
      }
    }else if( pPk ){
      addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
................................................................................
    /* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      sqlite3VtabMakeWritable(pParse, pTab);
      sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, OE_Abort);
      assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
      sqlite3MayAbort(pParse);
      if( eOnePass==ONEPASS_SINGLE && sqlite3IsToplevel(pParse) ){
        pParse->isMultiWrite = 0;
      }
    }else
#endif
    {
      int count = (pParse->nested==0);    /* True to count changes */
      int iIdxNoSeek = -1;
      if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){
        iIdxNoSeek = aiCurOnePass[1];
................................................................................
  }
  nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
  regBase = sqlite3GetTempRange(pParse, nCol);
  if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
  for(j=0; j<nCol; j++){
    if( pPrior
     && pPrior->aiColumn[j]==pIdx->aiColumn[j]
     && pPrior->aiColumn[j]!=XN_EXPR
    ){
      /* This column was already computed by the previous index */
      continue;
    }
    sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
    /* If the column affinity is REAL but the number is an integer, then it
    ** might be stored in the table as an integer (using a compact
................................................................................
        ** the default collation sequences for each column. */
        int i, j;
        for(i=0; i<nCol; i++){
          i16 iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */
          char *zDfltColl;                  /* Def. collation for column */
          char *zIdxCol;                    /* Name of indexed column */

          if( iCol<0 ) break; /* No foreign keys against expression indexes */

          /* If the index uses a collation sequence that is different from
          ** the default collation sequence for the column, this index is
          ** unusable. Bail out early in this case.  */
          zDfltColl = pParent->aCol[iCol].zColl;
          if( !zDfltColl ){
            zDfltColl = "BINARY";
          }
................................................................................
      ** none of the child key values are).
      */
      if( pTab==pFKey->pFrom && nIncr==1 ){
        int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;
        for(i=0; i<nCol; i++){
          int iChild = aiCol[i]+1+regData;
          int iParent = pIdx->aiColumn[i]+1+regData;
          assert( pIdx->aiColumn[i]>=0 );
          assert( aiCol[i]!=pTab->iPKey );
          if( pIdx->aiColumn[i]==pTab->iPKey ){
            /* The parent key is a composite key that includes the IPK column */
            iParent = regData;
          }
          sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
          sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
................................................................................
      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight, 0);
    }else{
      Expr *pEq, *pAll = 0;
      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
      assert( pIdx!=0 );
      for(i=0; i<pPk->nKeyCol; i++){
        i16 iCol = pIdx->aiColumn[i];
        assert( iCol>=0 );
        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
        pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, iCol);
        pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight, 0);
        pAll = sqlite3ExprAnd(db, pAll, pEq);
      }
      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0, 0);
    }
................................................................................
      iCol = pFKey->aCol[0].iFrom;
      aiCol = &iCol;
    }
    for(i=0; i<pFKey->nCol; i++){
      if( aiCol[i]==pTab->iPKey ){
        aiCol[i] = -1;
      }
      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
#ifndef SQLITE_OMIT_AUTHORIZATION
      /* Request permission to read the parent key columns. If the 
      ** authorization callback returns SQLITE_IGNORE, behave as if any
      ** values read from the parent table are NULL. */
      if( db->xAuth ){
        int rcauth;
        char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
................................................................................
    for(p=pTab->pFKey; p; p=p->pNextFrom){
      for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
    }
    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
      Index *pIdx = 0;
      sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
      if( pIdx ){
        for(i=0; i<pIdx->nKeyCol; i++){
          assert( pIdx->aiColumn[i]>=0 );
          mask |= COLUMN_MASK(pIdx->aiColumn[i]);
        }
      }
    }
  }
  return mask;
}


................................................................................
      Token tToCol;               /* Name of column in parent table */
      int iFromCol;               /* Idx of column in child table */
      Expr *pEq;                  /* tFromCol = OLD.tToCol */

      iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
      assert( iFromCol>=0 );
      assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );
      assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
      tToCol.z = pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName;
      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;

      tToCol.n = sqlite3Strlen30(tToCol.z);
      tFromCol.n = sqlite3Strlen30(tFromCol.z);

      /* Create the expression "OLD.zToCol = zFromCol". It is important
................................................................................
      db->mallocFailed = 1;
      return 0;
    }
    for(n=0; n<pIdx->nColumn; n++){
      i16 x = pIdx->aiColumn[n];
      if( x>=0 ){
        pIdx->zColAff[n] = pTab->aCol[x].affinity;
      }else if( x==XN_ROWID ){
        pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
      }else{
        char aff;
        assert( x==XN_EXPR );
        assert( pIdx->aColExpr!=0 );
        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
        if( aff==0 ) aff = SQLITE_AFF_BLOB;
        pIdx->zColAff[n] = aff;
      }
    }
    pIdx->zColAff[n] = 0;
................................................................................
  int memId;                 /* Register holding max rowid */
  int addr;                  /* A VDBE address */
  Vdbe *v = pParse->pVdbe;   /* VDBE under construction */

  /* This routine is never called during trigger-generation.  It is
  ** only called from the top-level */
  assert( pParse->pTriggerTab==0 );
  assert( sqlite3IsToplevel(pParse) );

  assert( v );   /* We failed long ago if this is not so */
  for(p = pParse->pAinc; p; p = p->pNext){
    pDb = &db->aDb[p->iDb];
    memId = p->regCtr;
    assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
    sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
................................................................................
    /* Create a record for this index entry as it should appear after
    ** the insert or update.  Store that record in the aRegIdx[ix] register
    */
    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField==XN_EXPR ){
        pParse->ckBase = regNewData+1;
        sqlite3ExprCode(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
        pParse->ckBase = 0;
        VdbeComment((v, "%s column %d", pIdx->zName, i));
      }else{
        if( iField==XN_ROWID || iField==pTab->iPKey ){
          if( regRowid==regIdx+i ) continue; /* ROWID already in regIdx+i */
          x = regNewData;
          regRowid =  pIdx->pPartIdxWhere ? -1 : regIdx+i;
        }else{
          x = iField + regNewData + 1;
        }
        sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
................................................................................
        }
      }else{
        int x;
        /* Extract the PRIMARY KEY from the end of the index entry and
        ** store it in registers regR..regR+nPk-1 */
        if( pIdx!=pPk ){
          for(i=0; i<pPk->nKeyCol; i++){
            assert( pPk->aiColumn[i]>=0 );
            x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
            sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
            VdbeComment((v, "%s.%s", pTab->zName,
                         pTab->aCol[pPk->aiColumn[i]].zName));
          }
        }
        if( isUpdate ){
................................................................................
          int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
          int op = OP_Ne;
          int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
  
          for(i=0; i<pPk->nKeyCol; i++){
            char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
            x = pPk->aiColumn[i];
            assert( x>=0 );
            if( i==(pPk->nKeyCol-1) ){
              addrJump = addrUniqueOk;
              op = OP_Eq;
            }
            sqlite3VdbeAddOp4(v, op, 
                regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
            );
................................................................................
  if( pDest->onError!=pSrc->onError ){
    return 0;   /* Different conflict resolution strategies */
  }
  for(i=0; i<pSrc->nKeyCol; i++){
    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
      return 0;   /* Different columns indexed */
    }
    if( pSrc->aiColumn[i]==XN_EXPR ){
      assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
      if( sqlite3ExprCompare(pSrc->aColExpr->a[i].pExpr,
                             pDest->aColExpr->a[i].pExpr, -1)!=0 ){
        return 0;   /* Different expressions in the index */
      }
    }
    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
................................................................................

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const int iLn = VDBE_OFFSET_LINENO(2);
    static const VdbeOpList endCode[] = {
      { OP_AddImm,      1, 0,        0},    /* 0 */
      { OP_If,          1, 0,        0},    /* 1 */
      { OP_String8,     0, 3,        0},    /* 2 */
      { OP_ResultRow,   3, 1,        0},
    };

    int isQuick = (sqlite3Tolower(zLeft[0])=='q');

    /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
    ** then iDb is set to the index of the database identified by <db>.
................................................................................
          ** or (2) the next entry has a different key */
          if( IsUniqueIndex(pIdx) ){
            int uniqOk = sqlite3VdbeMakeLabel(v);
            int jmp6;
            int kk;
            for(kk=0; kk<pIdx->nKeyCol; kk++){
              int iCol = pIdx->aiColumn[kk];
              assert( iCol!=XN_ROWID && iCol<pTab->nCol );
              if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
              sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
              VdbeCoverage(v);
            }
            jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
            sqlite3VdbeGoto(v, uniqOk);
            sqlite3VdbeJumpHere(v, jmp6);
................................................................................
          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
        }
#endif /* SQLITE_OMIT_BTREECOUNT */
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
    sqlite3VdbeChangeP2(v, addr, -mxErr);
    sqlite3VdbeJumpHere(v, addr+1);
    sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
  }
  break;
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
................................................................................
    int addr;
    int iLimit;
    if( pSelect->iOffset ){
      iLimit = pSelect->iOffset+1;
    }else{
      iLimit = pSelect->iLimit;
    }
    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, 1); VdbeCoverage(v);
    sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
    sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
................................................................................
*/
static void codeOffset(
  Vdbe *v,          /* Generate code into this VM */
  int iOffset,      /* Register holding the offset counter */
  int iContinue     /* Jump here to skip the current record */
){
  if( iOffset>0 ){

    sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);

    VdbeComment((v, "OFFSET"));

  }
}

/*
** Add code that will check to make sure the N registers starting at iMem
** form a distinct entry.  iTab is a sorting index that holds previously
** seen combinations of the N values.  A new entry is made in iTab
................................................................................
** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
  Vdbe *v = 0;
  int iLimit = 0;
  int iOffset;
  int n;
  if( p->iLimit ) return;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** controversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
................................................................................
    }
    if( p->pOffset ){
      p->iOffset = iOffset = ++pParse->nMem;
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
      sqlite3ExprCode(pParse, p->pOffset, iOffset);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
      VdbeComment((v, "OFFSET counter"));
      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iOffset, iOffset, 0);


      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
      VdbeComment((v, "LIMIT+OFFSET"));



      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iLimit, iOffset+1, -1);
    }
  }
}

#ifndef SQLITE_OMIT_COMPOUND_SELECT
/*
** Return the appropriate collating sequence for the iCol-th column of
................................................................................
      }
      p->pPrior = 0;
      p->iLimit = pPrior->iLimit;
      p->iOffset = pPrior->iOffset;
      if( p->iLimit ){
        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
        VdbeComment((v, "Jump ahead if LIMIT reached"));
        if( p->iOffset ){
          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iOffset, p->iOffset, 0);
          sqlite3VdbeAddOp3(v, OP_Add, p->iLimit, p->iOffset, p->iOffset+1);
          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iLimit, p->iOffset+1, -1);
        }
      }
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &dest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      p->nSelectRow += pPrior->nSelectRow;
................................................................................

  /* Look up every table named in the FROM clause of the select.  If
  ** an entry of the FROM clause is a subquery instead of a table or view,
  ** then create a transient table structure to describe the subquery.
  */
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab;
    assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
    if( pFrom->fg.isRecursive ) continue;
    assert( pFrom->pTab==0 );








#ifndef SQLITE_OMIT_CTE
    if( withExpand(pWalker, pFrom) ) return WRC_Abort;
    if( pFrom->pTab ) {} else
#endif
    if( pFrom->zName==0 ){
#ifndef SQLITE_OMIT_SUBQUERY
      Select *pSel = pFrom->pSelect;
................................................................................
static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
  Parse *pParse;
  int i;
  SrcList *pTabList;
  struct SrcList_item *pFrom;

  assert( p->selFlags & SF_Resolved );
  assert( (p->selFlags & SF_HasTypeInfo)==0 );
  p->selFlags |= SF_HasTypeInfo;
  pParse = pWalker->pParse;
  pTabList = p->pSrc;
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab = pFrom->pTab;
    assert( pTab!=0 );
    if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
      /* A sub-query in the FROM clause of a SELECT */
      Select *pSel = pFrom->pSelect;
      if( pSel ){
        while( pSel->pPrior ) pSel = pSel->pPrior;
        selectAddColumnTypeAndCollation(pParse, pTab, pSel);

      }
    }
  }
}
#endif


................................................................................
  int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */
  int iEph = 0;          /* Ephemeral table holding all primary key values */
  int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */

  /* Register Allocations */
  int regRowCount = 0;   /* A count of rows changed */
  int regOldRowid = 0;   /* The old rowid */
  int regNewRowid = 0;   /* The new rowid */
  int regNew = 0;        /* Content of the NEW.* table in triggers */
  int regOld = 0;        /* Content of OLD.* table in triggers */
  int regRowSet = 0;     /* Rowset of rows to be updated */
  int regKey = 0;        /* composite PRIMARY KEY value */

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
................................................................................

  /* Begin generating code. */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto update_cleanup;
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, 1, iDb);












  /* Allocate required registers. */
  if( !IsVirtual(pTab) ){
    regRowSet = ++pParse->nMem;
    regOldRowid = regNewRowid = ++pParse->nMem;
    if( chngPk || pTrigger || hasFK ){
      regOld = pParse->nMem + 1;
      pParse->nMem += pTab->nCol;
    }
    if( chngKey || pTrigger || hasFK ){
      regNewRowid = ++pParse->nMem;
    }
    regNew = pParse->nMem + 1;
    pParse->nMem += pTab->nCol;
  }

  /* Start the view context. */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

  /* If we are trying to update a view, realize that view into
................................................................................

  /* Resolve the column names in all the expressions in the
  ** WHERE clause.
  */
  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
    goto update_cleanup;
  }

#ifndef SQLITE_OMIT_VIRTUALTABLE
  /* Virtual tables must be handled separately */
  if( IsVirtual(pTab) ){
    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
                       pWhere, onError);
    goto update_cleanup;
  }
#endif

  /* Begin the database scan
  */
  if( HasRowid(pTab) ){
    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
    pWInfo = sqlite3WhereBegin(
        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
................................................................................
    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
                               WHERE_ONEPASS_DESIRED, iIdxCur);
    if( pWInfo==0 ) goto update_cleanup;
    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
    for(i=0; i<nPk; i++){
      assert( pPk->aiColumn[i]>=0 );
      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
                                      iPk+i);
    }
    if( okOnePass ){
      sqlite3VdbeChangeToNoop(v, addrOpen);
      nKey = nPk;
      regKey = iPk;
................................................................................
  ** the database after the BEFORE triggers are fired anyway (as the trigger 
  ** may have modified them). So not loading those that are not going to
  ** be used eliminates some redundant opcodes.
  */
  newmask = sqlite3TriggerColmask(
      pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
  );

  for(i=0; i<pTab->nCol; i++){
    if( i==pTab->iPKey ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
    }else{
      j = aXRef[i];
      if( j>=0 ){
        sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
................................................................................
 #undef pTrigger
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Generate code for an UPDATE of a virtual table.
**
** There are two possible strategies - the default and the special 
** "onepass" strategy. Onepass is only used if the virtual table 
** implementation indicates that pWhere may match at most one row.
**
** The default strategy is to create an ephemeral table that contains
** for each row to be changed:
**
**   (A)  The original rowid of that row.
**   (B)  The revised rowid for the row.
**   (C)  The content of every column in the row.
**
** Then loop through the contents of this ephemeral table executing a


** VUpdate for each row. When finished, drop the ephemeral table.
**
** The "onepass" strategy does not use an ephemeral table. Instead, it
** stores the same values (A, B and C above) in a register array and
** makes a single invocation of VUpdate.


*/
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
  SrcList *pSrc,       /* The virtual table to be modified */
  Table *pTab,         /* The virtual table */
  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
  Expr *pRowid,        /* Expression used to recompute the rowid */
  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
  int onError          /* ON CONFLICT strategy */
){
  Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */



  int ephemTab;             /* Table holding the result of the SELECT */
  int i;                    /* Loop counter */


  sqlite3 *db = pParse->db; /* Database connection */
  const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
  WhereInfo *pWInfo;
  int nArg = 2 + pTab->nCol;      /* Number of arguments to VUpdate */
  int regArg;                     /* First register in VUpdate arg array */
  int regRec;                     /* Register in which to assemble record */
  int regRowid;                   /* Register for ephem table rowid */
  int iCsr = pSrc->a[0].iCursor;  /* Cursor used for virtual table scan */
  int aDummy[2];                  /* Unused arg for sqlite3WhereOkOnePass() */
  int bOnePass;                   /* True to use onepass strategy */
  int addr;                       /* Address of OP_OpenEphemeral */




  /* Allocate nArg registers to martial the arguments to VUpdate. Then
  ** create and open the ephemeral table in which the records created from
  ** these arguments will be temporarily stored. */
  assert( v );
  ephemTab = pParse->nTab++;
  addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
  regArg = pParse->nMem + 1;
  pParse->nMem += nArg;
  regRec = ++pParse->nMem;
  regRowid = ++pParse->nMem;

  /* Start scanning the virtual table */
  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
  if( pWInfo==0 ) return;

  /* Populate the argument registers. */
  sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
  if( pRowid ){


    sqlite3ExprCode(pParse, pRowid, regArg+1);
  }else{
    sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
  }

  for(i=0; i<pTab->nCol; i++){
    if( aXRef[i]>=0 ){
      sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
    }else{

      sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
    }

  }







  bOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);





  if( bOnePass ){
    /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
    ** above. Also, if this is a top-level parse (not a trigger), clear the
    ** multi-write flag so that the VM does not open a statement journal */
    sqlite3VdbeChangeToNoop(v, addr);
    if( sqlite3IsToplevel(pParse) ){
      pParse->isMultiWrite = 0;
    }
  }else{
    /* Create a record from the argument register contents and insert it into
    ** the ephemeral table. */


    sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
    sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);

  }


  if( bOnePass==0 ){
    /* End the virtual table scan */
    sqlite3WhereEnd(pWInfo);

    /* Begin scannning through the ephemeral table. */
    addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);

    /* Extract arguments from the current row of the ephemeral table and 
    ** invoke the VUpdate method.  */
    for(i=0; i<nArg; i++){
      sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);
    }
  }
  sqlite3VtabMakeWritable(pParse, pTab);
  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
  sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
  sqlite3MayAbort(pParse);

  /* End of the ephemeral table scan. Or, if using the onepass strategy,
  ** jump to here if the scan visited zero rows. */
  if( bOnePass==0 ){
    sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
    sqlite3VdbeJumpHere(v, addr);
    sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
  }else{
    sqlite3WhereEnd(pWInfo);
  }


}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/************** End of update.c **********************************************/
/************** Begin file vacuum.c ******************************************/
/*
** 2003 April 6
................................................................................

    /* Invoke the xBegin method. If successful, add the vtab to the 
    ** sqlite3.aVTrans[] array. */
    rc = growVTrans(db);
    if( rc==SQLITE_OK ){
      rc = pModule->xBegin(pVTab->pVtab);
      if( rc==SQLITE_OK ){
        int iSvpt = db->nStatement + db->nSavepoint;
        addToVTrans(db, pVTab);
        if( iSvpt ) rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, iSvpt-1);
      }
    }
  }
  return rc;
}

/*
................................................................................
}

/*
** 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;
}

/*
** 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.
................................................................................
    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
                            iIdxCur, 0, regBase, nSkip);
    VdbeCoverageIf(v, bRev==0);
    VdbeCoverageIf(v, bRev!=0);
    sqlite3VdbeJumpHere(v, j);
    for(j=0; j<nSkip; j++){
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
      testcase( pIdx->aiColumn[j]==XN_EXPR );
      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
    }
  }    

  /* Evaluate the equality constraints
  */
  assert( zAff==0 || (int)strlen(zAff)>=nEq );
................................................................................
    VdbeCoverage(v);
    pLoop->u.vtab.needFree = 0;
    for(j=0; j<nConstraint && j<16; j++){
      if( (pLoop->u.vtab.omitMask>>j)&1 ){
        disableTerm(pLevel, pLoop->aLTerm[j]);
      }
    }

    pLevel->p1 = iCur;
    pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
    sqlite3ExprCachePop(pParse);
  }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  if( (pLoop->wsFlags & WHERE_IPK)!=0
................................................................................
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
#ifdef WHERETRACE_ENABLED
  if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){
    sqlite3DebugPrintf("%s cursors: %d %d\n",
         pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",
         aiCur[0], aiCur[1]);
  }
#endif
  return pWInfo->eOnePass;
}

/*
** Move the content of pSrc into pDest
*/
static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
................................................................................
  WhereClause *pWC;    /* Shorthand for pScan->pWC */
  WhereTerm *pTerm;    /* The term being tested */
  int k = pScan->k;    /* Where to start scanning */

  while( pScan->iEquiv<=pScan->nEquiv ){
    iCur = pScan->aiCur[pScan->iEquiv-1];
    iColumn = pScan->aiColumn[pScan->iEquiv-1];
    if( iColumn==XN_EXPR && pScan->pIdxExpr==0 ) return 0;
    while( (pWC = pScan->pWC)!=0 ){
      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
        if( pTerm->leftCursor==iCur
         && pTerm->u.leftColumn==iColumn
         && (iColumn!=XN_EXPR
             || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
        ){
          if( (pTerm->eOperator & WO_EQUIV)!=0
           && pScan->nEquiv<ArraySize(pScan->aiCur)
           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
          ){
................................................................................
  /* memset(pScan, 0, sizeof(*pScan)); */
  pScan->pOrigWC = pWC;
  pScan->pWC = pWC;
  pScan->pIdxExpr = 0;
  if( pIdx ){
    j = iColumn;
    iColumn = pIdx->aiColumn[j];
    if( iColumn==XN_EXPR ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
  }
  if( pIdx && iColumn>=0 ){
    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
    pScan->zCollName = pIdx->azColl[j];
  }else{
    pScan->idxaff = 0;
    pScan->zCollName = 0;
................................................................................
    for(i=BMS-1; i<pTable->nCol; i++){
      pIdx->aiColumn[n] = i;
      pIdx->azColl[n] = "BINARY";
      n++;
    }
  }
  assert( n==nKeyCol );
  pIdx->aiColumn[n] = XN_ROWID;
  pIdx->azColl[n] = "BINARY";

  /* Create the automatic index */
  assert( pLevel->iIdxCur>=0 );
  pLevel->iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
................................................................................
      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 ){
................................................................................
    if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
      if( pExpr->iColumn<0 ) return 1;
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
      }
    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
      for(jj=0; jj<pIndex->nKeyCol; jj++){
        if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
        if( sqlite3ExprCompare(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
          return 1;
        }
      }
    }
  }
  return 0;
................................................................................
    if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
    pIdxInfo->idxStr = 0;
    pIdxInfo->idxNum = 0;
    pIdxInfo->needToFreeIdxStr = 0;
    pIdxInfo->orderByConsumed = 0;
    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
    pIdxInfo->estimatedRows = 25;
    pIdxInfo->idxFlags = 0;
    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
    if( rc ) goto whereLoopAddVtab_exit;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    pNew->prereq = mExtra;
    mxTerm = -1;
    assert( pNew->nLSlot>=nConstraint );
    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
................................................................................
          }
          /* A virtual table that is constrained by an IN clause may not
          ** consume the ORDER BY clause because (1) the order of IN terms
          ** is not necessarily related to the order of output terms and
          ** (2) Multiple outputs from a single IN value will not merge
          ** together.  */
          pIdxInfo->orderByConsumed = 0;
          pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
        }
      }
    }
    if( i>=nConstraint ){
      pNew->nLTerm = mxTerm+1;
      assert( pNew->nLTerm<=pNew->nLSlot );
      pNew->u.vtab.idxNum = pIdxInfo->idxNum;
................................................................................
      pIdxInfo->needToFreeIdxStr = 0;
      pNew->u.vtab.idxStr = pIdxInfo->idxStr;
      pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
                                      pIdxInfo->nOrderBy : 0);
      pNew->rSetup = 0;
      pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
      pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);

      /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
      ** that the scan will visit at most one row. Clear it otherwise. */
      if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){
        pNew->wsFlags |= WHERE_ONEROW;
      }else{
        pNew->wsFlags &= ~WHERE_ONEROW;
      }
      whereLoopInsert(pBuilder, pNew);
      if( pNew->u.vtab.needFree ){
        sqlite3_free(pNew->u.vtab.idxStr);
        pNew->u.vtab.needFree = 0;
      }
    }
  }  
................................................................................
        nColumn = 1;
      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
        return 0;
      }else{
        nKeyCol = pIndex->nKeyCol;
        nColumn = pIndex->nColumn;
        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
        assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
                          || !HasRowid(pIndex->pTable));
        isOrderDistinct = IsUniqueIndex(pIndex);
      }

      /* Loop through all columns of the index and deal with the ones
      ** that are not constrained by == or IN.
      */
      rev = revSet = 0;
................................................................................
        ** (revIdx) for the j-th column of the index.
        */
        if( pIndex ){
          iColumn = pIndex->aiColumn[j];
          revIdx = pIndex->aSortOrder[j];
          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
        }else{
          iColumn = XN_ROWID;
          revIdx = 0;
        }

        /* An unconstrained column that might be NULL means that this
        ** WhereLoop is not well-ordered
        */
        if( isOrderDistinct
................................................................................
      /* Try to ORDER BY the result set to make distinct processing easier */
      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
      pWInfo->pOrderBy = pResultSet;
    }
  }

  /* Construct the WhereLoop objects */
  WHERETRACE(0xffff,("*** Optimizer Start *** (wctrlFlags: 0x%x)\n",
             wctrlFlags));
#if defined(WHERETRACE_ENABLED)
  if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */
    int i;
    for(i=0; i<sWLB.pWC->nTerm; i++){
      whereTermPrint(&sWLB.pWC->a[i], i);
    }
  }
................................................................................
        if( pOp->p1!=pLevel->iTabCur ) continue;
        if( pOp->opcode==OP_Column ){
          int x = pOp->p2;
          assert( pIdx->pTable==pTab );
          if( !HasRowid(pTab) ){
            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
            x = pPk->aiColumn[x];
            assert( x>=0 );
          }
          x = sqlite3ColumnOfIndex(pIdx, x);
          if( x>=0 ){
            pOp->p2 = x;
            pOp->p1 = pLevel->iIdxCur;
          }
          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 );
................................................................................
    int nPrefix;                  /* Prefix length (0 for main terms index) */
    Fts3Hash hPending;            /* Pending terms table for this index */
  } *aIndex;
  int nMaxPendingData;            /* Max pending data before flush to disk */
  int nPendingData;               /* Current bytes of pending data */
  sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */
  int iPrevLangid;                /* Langid of recently inserted document */
  int bPrevDelete;                /* True if last operation was a delete */

#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  /* State variables used for validating that the transaction control
  ** methods of the virtual table are called at appropriate times.  These
  ** values do not contribute to FTS functionality; they are used for
  ** verifying the operation of the SQLite core.
  */
................................................................................
static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
#if SQLITE_VERSION_NUMBER>=3008002
  if( sqlite3_libversion_number()>=3008002 ){
    pIdxInfo->estimatedRows = nRow;
  }
#endif
}

/*
** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this
** extension is currently being used by a version of SQLite too old to
** support index-info flags. In that case this function is a no-op.
*/
static void fts3SetUniqueFlag(sqlite3_index_info *pIdxInfo){
#if SQLITE_VERSION_NUMBER>=3008012
  if( sqlite3_libversion_number()>=3008012 ){
    pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;
  }
#endif
}

/* 
** Implementation of the xBestIndex method for FTS3 tables. There
** are three possible strategies, in order of preference:
**
**   1. Direct lookup by rowid or docid. 
**   2. Full-text search using a MATCH operator on a non-docid column.
................................................................................
        case SQLITE_INDEX_CONSTRAINT_LE:
        case SQLITE_INDEX_CONSTRAINT_LT:
          iDocidLe = i;
          break;
      }
    }
  }

  /* If using a docid=? or rowid=? strategy, set the UNIQUE flag. */
  if( pInfo->idxNum==FTS3_DOCID_SEARCH ) fts3SetUniqueFlag(pInfo);

  iIdx = 1;
  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
  if( iLangidCons>=0 ){
................................................................................
  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
  int eType = pRoot->eType;       /* Type of node in this tree */

  if( nMaxDepth==0 ){
    rc = SQLITE_ERROR;
  }

  if( rc==SQLITE_OK ){
    if( (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
      Fts3Expr **apLeaf;
      apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
      if( 0==apLeaf ){
        rc = SQLITE_NOMEM;
      }else{
        memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
      }

      if( rc==SQLITE_OK ){
        int i;
        Fts3Expr *p;

        /* Set $p to point to the left-most leaf in the tree of eType nodes. */
        for(p=pRoot; p->eType==eType; p=p->pLeft){
          assert( p->pParent==0 || p->pParent->pLeft==p );
          assert( p->pLeft && p->pRight );
        }

        /* This loop runs once for each leaf in the tree of eType nodes. */
        while( 1 ){
          int iLvl;
          Fts3Expr *pParent = p->pParent;     /* Current parent of p */

          assert( pParent==0 || pParent->pLeft==p );
          p->pParent = 0;
          if( pParent ){
            pParent->pLeft = 0;
          }else{
            pRoot = 0;
          }
          rc = fts3ExprBalance(&p, nMaxDepth-1);
          if( rc!=SQLITE_OK ) break;

          for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){
            if( apLeaf[iLvl]==0 ){
              apLeaf[iLvl] = p;
              p = 0;
            }else{
              assert( pFree );
              pFree->pLeft = apLeaf[iLvl];
              pFree->pRight = p;
              pFree->pLeft->pParent = pFree;
              pFree->pRight->pParent = pFree;

              p = pFree;
              pFree = pFree->pParent;
              p->pParent = 0;
              apLeaf[iLvl] = 0;
            }
          }
          if( p ){
            sqlite3Fts3ExprFree(p);
            rc = SQLITE_TOOBIG;
            break;
          }

          /* If that was the last leaf node, break out of the loop */
          if( pParent==0 ) break;

          /* Set $p to point to the next leaf in the tree of eType nodes */
          for(p=pParent->pRight; p->eType==eType; p=p->pLeft);

          /* Remove pParent from the original tree. */
          assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
          pParent->pRight->pParent = pParent->pParent;
          if( pParent->pParent ){
            pParent->pParent->pLeft = pParent->pRight;
          }else{
            assert( pParent==pRoot );
            pRoot = pParent->pRight;
          }

          /* Link pParent into the free node list. It will be used as an
          ** internal node of the new tree.  */
          pParent->pParent = pFree;
          pFree = pParent;
        }

        if( rc==SQLITE_OK ){
          p = 0;
          for(i=0; i<nMaxDepth; i++){
            if( apLeaf[i] ){
              if( p==0 ){
                p = apLeaf[i];
                p->pParent = 0;
              }else{
                assert( pFree!=0 );
                pFree->pRight = p;
                pFree->pLeft = apLeaf[i];
                pFree->pLeft->pParent = pFree;
                pFree->pRight->pParent = pFree;

                p = pFree;
                pFree = pFree->pParent;
                p->pParent = 0;
              }
            }
          }
          pRoot = p;
        }else{
          /* An error occurred. Delete the contents of the apLeaf[] array 
          ** and pFree list. Everything else is cleaned up by the call to
          ** sqlite3Fts3ExprFree(pRoot) below.  */
          Fts3Expr *pDel;
          for(i=0; i<nMaxDepth; i++){
            sqlite3Fts3ExprFree(apLeaf[i]);
          }
          while( (pDel=pFree)!=0 ){
            pFree = pDel->pParent;
            sqlite3_free(pDel);
          }
        }

        assert( pFree==0 );
        sqlite3_free( apLeaf );
      }
    }else if( eType==FTSQUERY_NOT ){
      Fts3Expr *pLeft = pRoot->pLeft;
      Fts3Expr *pRight = pRoot->pRight;

      pRoot->pLeft = 0;
      pRoot->pRight = 0;
      pLeft->pParent = 0;
      pRight->pParent = 0;

      rc = fts3ExprBalance(&pLeft, nMaxDepth-1);
      if( rc==SQLITE_OK ){
        rc = fts3ExprBalance(&pRight, nMaxDepth-1);
      }

      if( rc!=SQLITE_OK ){
        sqlite3Fts3ExprFree(pRight);
        sqlite3Fts3ExprFree(pLeft);
      }else{
        assert( pLeft && pRight );
        pRoot->pLeft = pLeft;
        pLeft->pParent = pRoot;
        pRoot->pRight = pRight;
        pRight->pParent = pRoot;
      }
    }
  }
  
  if( rc!=SQLITE_OK ){
    sqlite3Fts3ExprFree(pRoot);
    pRoot = 0;
  }
  *pp = pRoot;
  return rc;
}
................................................................................
/* 
** Calling this function indicates that subsequent calls to 
** fts3PendingTermsAdd() are to add term/position-list pairs for the
** contents of the document with docid iDocid.
*/
static int fts3PendingTermsDocid(
  Fts3Table *p,                   /* Full-text table handle */
  int bDelete,                    /* True if this op is a delete */
  int iLangid,                    /* Language id of row being written */
  sqlite_int64 iDocid             /* Docid of row being written */
){
  assert( iLangid>=0 );
  assert( bDelete==1 || bDelete==0 );

  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */
  if( iDocid<p->iPrevDocid 
   || (iDocid==p->iPrevDocid && p->bPrevDelete==0)
   || p->iPrevLangid!=iLangid
   || p->nPendingData>p->nMaxPendingData 
  ){
    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  p->iPrevLangid = iLangid;
  p->bPrevDelete = bDelete;
  return SQLITE_OK;
}

/*
** Discard the contents of the pending-terms hash tables. 
*/
SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *p){
................................................................................
  assert( *pbFound==0 );
  if( *pRC ) return;
  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);
  if( rc==SQLITE_OK ){
    if( SQLITE_ROW==sqlite3_step(pSelect) ){
      int i;
      int iLangid = langidFromSelect(p, pSelect);
      i64 iDocid = sqlite3_column_int64(pSelect, 0);
      rc = fts3PendingTermsDocid(p, 1, iLangid, iDocid);
      for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
        int iCol = i-1;
        if( p->abNotindexed[iCol]==0 ){
          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
        }
................................................................................
    pNext = &pReader->aDoclist[pReader->nDoclist];
  }

  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){

    if( fts3SegReaderIsPending(pReader) ){
      Fts3HashElem *pElem = *(pReader->ppNextElem);
      sqlite3_free(pReader->aNode);
      pReader->aNode = 0;
      if( pElem ){
        char *aCopy;
        PendingList *pList = (PendingList *)fts3HashData(pElem);
        int nCopy = pList->nData+1;
        pReader->zTerm = (char *)fts3HashKey(pElem);
        pReader->nTerm = fts3HashKeysize(pElem);
        aCopy = (char*)sqlite3_malloc(nCopy);
        if( !aCopy ) return SQLITE_NOMEM;
        memcpy(aCopy, pList->aData, nCopy);
        pReader->nNode = pReader->nDoclist = nCopy;
        pReader->aNode = pReader->aDoclist = aCopy;
        pReader->ppNextElem++;
        assert( pReader->aNode );
      }
      return SQLITE_OK;
    }

    fts3SegReaderSetEof(pReader);
................................................................................
}

/*
** Free all allocations associated with the iterator passed as the 
** second argument.
*/
SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){
  if( pReader ){
    if( !fts3SegReaderIsPending(pReader) ){
      sqlite3_free(pReader->zTerm);
    }
    if( !fts3SegReaderIsRootOnly(pReader) ){
      sqlite3_free(pReader->aNode);

    }
    sqlite3_blob_close(pReader->pBlob);
  }
  sqlite3_free(pReader);
}

/*
** Allocate a new SegReader object.
*/
................................................................................
        aSzDel = &aSzIns[p->nColumn+1];
      }
    }

    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
      int iCol;
      int iLangid = langidFromSelect(p, pStmt);
      rc = fts3PendingTermsDocid(p, 0, iLangid, sqlite3_column_int64(pStmt, 0));
      memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
      for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
        if( p->abNotindexed[iCol]==0 ){
          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
        }
................................................................................
    if( bInsertDone==0 ){
      rc = fts3InsertData(p, apVal, pRowid);
      if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){
        rc = FTS_CORRUPT_VTAB;
      }
    }
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=p->iPrevDocid ) ){
      rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);
    }
    if( rc==SQLITE_OK ){
      assert( p->iPrevDocid==*pRowid );
      rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);
    }
    if( p->bHasDocsize ){
      fts3InsertDocsize(&rc, p, aSzIns);

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.12"
#define SQLITE_VERSION_NUMBER 3008012
#define SQLITE_SOURCE_ID      "2015-09-28 14:40:20 9d057f52217e7ef9c3f3eb84117abe3365503f44"

/*
** 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
................................................................................
** strategy. A cost of N indicates that the cost of the strategy is similar
** to a linear scan of an SQLite table with N rows. A cost of log(N) 
** indicates that the expense of the operation is similar to that of a
** binary search on a unique indexed field of an SQLite table with N rows.
**
** ^The estimatedRows value is an estimate of the number of rows that
** will be returned by the strategy.















**
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
** structure for SQLite version 3.8.2. If a virtual table extension is
** used with an SQLite version earlier than 3.8.2, the results of attempting 
** to read or write the estimatedRows field are undefined (but are likely 
** to included crashing the application). The estimatedRows field should
** therefore only be used if [sqlite3_libversion_number()] returns a
** value greater than or equal to 3008002.



*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
................................................................................
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */


};






/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the wHERE clause of
** a query that uses a [virtual table].

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.8.12"
#define SQLITE_VERSION_NUMBER 3008012
#define SQLITE_SOURCE_ID      "2015-10-07 17:06:17 13adcd038fc20dd1b6f344f79b449b4034f8f8f2"

/*
** 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
................................................................................
** strategy. A cost of N indicates that the cost of the strategy is similar
** to a linear scan of an SQLite table with N rows. A cost of log(N) 
** indicates that the expense of the operation is similar to that of a
** binary search on a unique indexed field of an SQLite table with N rows.
**
** ^The estimatedRows value is an estimate of the number of rows that
** will be returned by the strategy.
**
** The xBestIndex method may optionally populate the idxFlags field with a 
** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
** assumes that the strategy may visit at most one row. 
**
** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
** SQLite also assumes that if a call to the xUpdate() method is made as
** part of the same statement to delete or update a virtual table row and the
** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
** any database changes. In other words, if the xUpdate() returns
** SQLITE_CONSTRAINT, the database contents must be exactly as they were
** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
** the xUpdate method are automatically rolled back by SQLite.
**
** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
** structure for SQLite version 3.8.2. If a virtual table extension is
** used with an SQLite version earlier than 3.8.2, the results of attempting 
** to read or write the estimatedRows field are undefined (but are likely 
** to included crashing the application). The estimatedRows field should
** therefore only be used if [sqlite3_libversion_number()] returns a
** value greater than or equal to 3008002. Similarly, the idxFlags field
** was added for version 3.8.12. It may therefore only be used if
** sqlite3_libversion_number() returns a value greater than or equal to
** 3008012.
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
  struct sqlite3_index_constraint {
     int iColumn;              /* Column on left-hand side of constraint */
     unsigned char op;         /* Constraint operator */
................................................................................
  int idxNum;                /* Number used to identify the index */
  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
  int orderByConsumed;       /* True if output is already ordered */
  double estimatedCost;           /* Estimated cost of using this index */
  /* Fields below are only available in SQLite 3.8.2 and later */
  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
  /* Fields below are only available in SQLite 3.8.12 and later */
  int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
};

/*
** CAPI3REF: Virtual Table Scan Flags
*/
#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros defined the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the wHERE clause of
** a query that uses a [virtual table].