**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.38 2008/01/12 12:48:08 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
    }
    sqlite3VdbeAddOp4(v, OP_RegMakeRec, regFields, 3, regRec, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, addr);
  }
}

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.39 2008/01/17 02:36:28 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
      sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp);
      sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
      sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regF2, regF2);
    }
    sqlite3VdbeAddOp4(v, OP_MakeRecord, regFields, 3, regRec, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, addr);
  }
}

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.465 2008/01/12 21:35:57 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................

/*
** Generate code that will erase and refill index *pIdx.  This is
** used to initialize a newly created index or to recompute the
** content of an index in response to a REINDEX command.
**
** if memRootPage is not negative, it means that the index is newly
** created.  The memory cell specified by memRootPage contains the
** root page number of the index.  If memRootPage is negative, then
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab;       /* Btree cursor used for pTab */
................................................................................

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){
    sqlite3VdbeAddOp1(v, OP_SCopy, memRootPage);
    tnum = 0;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
  }
  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
................................................................................
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
  Vdbe *v;
  v = sqlite3GetVdbe(pParse);
  if( v ){



    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, 0, 1);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp1(v, OP_Integer, minFormat);
    sqlite3VdbeAddOp2(v, OP_Ge, 0, sqlite3VdbeCurrentAddr(v)+3);
    sqlite3VdbeAddOp1(v, OP_Integer, minFormat);
    sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 1);



  }
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.466 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................

/*
** Generate code that will erase and refill index *pIdx.  This is
** used to initialize a newly created index or to recompute the
** content of an index in response to a REINDEX command.
**
** if memRootPage is not negative, it means that the index is newly
** created.  The register specified by memRootPage contains the
** root page number of the index.  If memRootPage is negative, then
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab;       /* Btree cursor used for pTab */
................................................................................

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){

    tnum = memRootPage;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
  }
  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
................................................................................
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
  Vdbe *v;
  v = sqlite3GetVdbe(pParse);
  if( v ){
    int r1 = sqlite3GetTempReg(pParse);
    int r2 = sqlite3GetTempReg(pParse);
    int j1;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, 1);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);

    j1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 1, r2);
    sqlite3VdbeJumpHere(v, j1);
    sqlite3ReleaseTempReg(pParse, r1);
    sqlite3ReleaseTempReg(pParse, r2);
  }
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.157 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }
#endif
  return 0;
}

/*
** Allocate nVal contiguous memory cells and return the index of the
** first. Also pop nVal elements from the stack and store them in the 
** registers. The element on the top of the stack is stored in the
** register with the largest index.
*/
int sqlite3StackToReg(Parse *p, int nVal){
  int i;
  int iRet = p->nMem+1;
  Vdbe *v = sqlite3GetVdbe(p);
  assert(v);
  p->nMem += nVal;
  for(i=nVal-1; i>=0; i--){
    sqlite3VdbeAddOp2(v, OP_Move, 0, iRet+i);
  }
  return iRet;
}

/*
** Generate code that will open a table for reading.
*/
void sqlite3OpenTable(
  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
................................................................................
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
    }else{
      sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nCol+1, regOut);
  sqlite3IndexAffinityStr(v, pIdx);
  sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
  return regBase;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.158 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }
#endif
  return 0;
}



















/*
** Generate code that will open a table for reading.
*/
void sqlite3OpenTable(
  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
................................................................................
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
    }else{
      sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
  sqlite3IndexAffinityStr(v, pIdx);
  sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
  return regBase;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.345 2008/01/13 19:02:11 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2, r1);
          sqlite3VdbeAddOp4(v, OP_RegMakeRec, r1, 1, r2, &affinity, 1);
          sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
        }
        sqlite3ReleaseTempReg(pParse, r1);
        sqlite3ReleaseTempReg(pParse, r2);
      }
      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      break;
................................................................................
        j3 = sqlite3VdbeAddOp3(v, OP_MustBeInt, r1, 0, 1);
        j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, r1);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);
        sqlite3VdbeJumpHere(v, j4);
      }else{
        r2 = regFree2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_RegMakeRec, r1, 1, r2, &affinity, 1);
        j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
      }
      sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
      sqlite3VdbeJumpHere(v, j2);
      sqlite3VdbeJumpHere(v, j5);
      break;
    }

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.346 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2, r1);
          sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
          sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
        }
        sqlite3ReleaseTempReg(pParse, r1);
        sqlite3ReleaseTempReg(pParse, r2);
      }
      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      break;
................................................................................
        j3 = sqlite3VdbeAddOp3(v, OP_MustBeInt, r1, 0, 1);
        j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, r1);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);
        sqlite3VdbeJumpHere(v, j4);
      }else{
        r2 = regFree2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
        j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
      }
      sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
      sqlite3VdbeJumpHere(v, j2);
      sqlite3VdbeJumpHere(v, j5);
      break;
    }

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.223 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
    int addr;               /* Address of the top of the loop */
    assert( v );
    pParse->nMem++;         /* Holds name of table */
    memId = ++pParse->nMem;
    pParse->nMem++;
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    addr = sqlite3VdbeCurrentAddr(v);

    sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addr+8);
    sqlite3VdbeAddOp2(v, OP_Column, iCur, 0);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp2(v, OP_Ne, 0, addr+7);
    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, memId+1);
    sqlite3VdbeAddOp3(v, OP_Column, iCur, 1, memId);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+8);
    sqlite3VdbeAddOp2(v, OP_Next, iCur, addr+1);
    sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  }
  return memId;
}

/*
** Update the maximum rowid for an autoincrement calculation.
................................................................................
    int j1;

    assert( v );
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iCur, memId+1);
    sqlite3VdbeJumpHere(v, j1);
    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, pTab->zName, 0);
    sqlite3VdbeAddOp3(v, OP_RegMakeRec, memId-1, 2, memId-1);
    sqlite3VdbeAddOp3(v, OP_Insert, iCur, memId-1, memId+1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp1(v, OP_Close, iCur);
  }
}
#else
/*
................................................................................
      */
      int regRec, regRowid;

      srcTab = pParse->nTab++;
      regRec = sqlite3GetTempReg(pParse);
      regRowid = sqlite3GetTempReg(pParse);
      sqlite3VdbeResolveLabel(v, iInsertBlock);
      sqlite3VdbeAddOp3(v, OP_RegMakeRec, regFromSelect, nColumn, regRec);
      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regRowid);
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      sqlite3ReleaseTempReg(pParse, regRec);
      sqlite3ReleaseTempReg(pParse, regRowid);

      /* The following code runs first because the GOTO at the very top
................................................................................
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i); 
      }else{
        assert( pSelect==0 ); /* Otherwise useTempTable is true */
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i);
      }
    }
    regRec = sqlite3GetTempReg(pParse);
    sqlite3VdbeAddOp3(v, OP_RegMakeRec, regCols, pTab->nCol, regRec);

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
................................................................................
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, 0);
        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
        if( pOp && pOp->opcode==OP_Null ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
          pOp->p1 = baseCur;
          pOp->p2 = regRowid;
          pOp->p3 = regAutoinc;
        }else{
          /* TODO: Avoid this use of the stack. */
          sqlite3VdbeAddOp2(v, OP_Move, 0, regRowid);
        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, sqlite3VdbeCurrentAddr(v)+2);
        sqlite3VdbeAddOp2(v, OP_Goto, -1, sqlite3VdbeCurrentAddr(v)+2);
        sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);

        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
      }
    }else if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
    }else{
      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
      appendFlag = 1;
................................................................................
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
      }
    }
    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
    sqlite3VdbeAddOp3(v, OP_RegMakeRec, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
    sqlite3IndexAffinityStr(v, pIdx);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);

    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
    if( overrideError!=OE_Default ){
................................................................................
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aRegIdx[i]==0 ) continue;
    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
  }
  regData = regRowid + 1;
  regRec = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regData, pTab->nCol, regRec);
  sqlite3TableAffinityStr(v, pTab);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);
  }
#endif
  if( pParse->nested ){

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.224 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
    int addr;               /* Address of the top of the loop */
    assert( v );
    pParse->nMem++;         /* Holds name of table */
    memId = ++pParse->nMem;
    pParse->nMem++;
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    addr = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, pTab->zName, 0);
    sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addr+8);
    sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, memId);

    sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId);
    sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, memId+1);
    sqlite3VdbeAddOp3(v, OP_Column, iCur, 1, memId);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+8);
    sqlite3VdbeAddOp2(v, OP_Next, iCur, addr+2);
    sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  }
  return memId;
}

/*
** Update the maximum rowid for an autoincrement calculation.
................................................................................
    int j1;

    assert( v );
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iCur, memId+1);
    sqlite3VdbeJumpHere(v, j1);

    sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, memId-1);
    sqlite3VdbeAddOp3(v, OP_Insert, iCur, memId-1, memId+1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp1(v, OP_Close, iCur);
  }
}
#else
/*
................................................................................
      */
      int regRec, regRowid;

      srcTab = pParse->nTab++;
      regRec = sqlite3GetTempReg(pParse);
      regRowid = sqlite3GetTempReg(pParse);
      sqlite3VdbeResolveLabel(v, iInsertBlock);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regRowid);
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      sqlite3ReleaseTempReg(pParse, regRec);
      sqlite3ReleaseTempReg(pParse, regRowid);

      /* The following code runs first because the GOTO at the very top
................................................................................
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i); 
      }else{
        assert( pSelect==0 ); /* Otherwise useTempTable is true */
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i);
      }
    }
    regRec = sqlite3GetTempReg(pParse);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRec);

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
................................................................................
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
        if( pOp && pOp->opcode==OP_Null ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
          pOp->p1 = baseCur;
          pOp->p2 = regRowid;
          pOp->p3 = regAutoinc;



        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        int j1;
        j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
        sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
        sqlite3VdbeJumpHere(v, j1);
        sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
      }
    }else if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
    }else{
      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
      appendFlag = 1;
................................................................................
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
      }
    }
    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
    sqlite3IndexAffinityStr(v, pIdx);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);

    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
    if( overrideError!=OE_Default ){
................................................................................
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aRegIdx[i]==0 ) continue;
    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
  }
  regData = regRowid + 1;
  regRec = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
  sqlite3TableAffinityStr(v, pTab);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);
  }
#endif
  if( pParse->nested ){

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.166 2008/01/12 21:35:57 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)
................................................................................
          /* When setting the auto_vacuum mode to either "full" or 
          ** "incremental", write the value of meta[6] in the database
          ** file. Before writing to meta[6], check that meta[3] indicates
          ** that this really is an auto-vacuum capable database.
          */
          static const VdbeOpList setMeta6[] = {
            { OP_Transaction,    0,               1,        0},    /* 0 */
            { OP_ReadCookie,     0,               0,        3},    /* 1 */
            { OP_If,             0,               0,        0},    /* 2 */
            { OP_Halt,           SQLITE_OK,       OE_Abort, 0},    /* 3 */
            { OP_Integer,        0,               0,        0},    /* 4 */
            { OP_SetCookie,      0,               6,        0},    /* 5 */
          };
          int iAddr;
          iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
          sqlite3VdbeChangeP1(v, iAddr, iDb);
          sqlite3VdbeChangeP1(v, iAddr+1, iDb);
          sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
          sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.167 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)
................................................................................
          /* When setting the auto_vacuum mode to either "full" or 
          ** "incremental", write the value of meta[6] in the database
          ** file. Before writing to meta[6], check that meta[3] indicates
          ** that this really is an auto-vacuum capable database.
          */
          static const VdbeOpList setMeta6[] = {
            { OP_Transaction,    0,               1,        0},    /* 0 */
            { OP_ReadCookie,     0,               1,        3},    /* 1 */
            { OP_If,             1,               0,        0},    /* 2 */
            { OP_Halt,           SQLITE_OK,       OE_Abort, 0},    /* 3 */
            { OP_Integer,        0,               1,        0},    /* 4 */
            { OP_SetCookie,      0,               6,        1},    /* 5 */
          };
          int iAddr;
          iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
          sqlite3VdbeChangeP1(v, iAddr, iDb);
          sqlite3VdbeChangeP1(v, iAddr+1, iDb);
          sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
          sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.402 2008/01/15 02:22:24 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3VdbeAddOp2(v, OP_Move, regData, regBase+nExpr+1);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    int iLimit;
    if( pSelect->pOffset ){
................................................................................
  int iMem           /* First element */
){
  Vdbe *v;
  int r1;

  v = pParse->pVdbe;
  r1 = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, iMem, N, r1);
  sqlite3VdbeAddOp3(v, OP_Found, iTab, addrRepeat, r1);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
  sqlite3ReleaseTempReg(pParse, r1);
}

/*
** Generate an error message when a SELECT is used within a subexpression
................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
#ifndef SQLITE_OMIT_COMPOUND_SELECT
    case SRT_Union: {
      sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, nColumn);
      if( aff ){
        sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      }
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      break;
    }

    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, nColumn);
      sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp2(v, OP_Delete, iParm, 0);
      break;
    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_EphemTab: {
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_RegMakeRec, iMem, nColumn, r1);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p, r1);
      }else{
        int r2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
................................................................................
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        pushOntoSorter(pParse, pOrderBy, p, iMem);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_RegMakeRec, iMem, 1, r1, &p->affinity, 1);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

................................................................................
    ** case of a subroutine, the subroutine itself is responsible for
    ** popping the data from the stack.
    */
    case SRT_Subroutine:
    case SRT_Callback: {
      if( pOrderBy ){
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_RegMakeRec, iMem, nColumn, r1);
        pushOntoSorter(pParse, pOrderBy, p, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }else if( eDest==SRT_Subroutine ){
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, iMem, nColumn);
      }
................................................................................
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      int j1;
      assert( nColumn==1 );
      j1 = sqlite3VdbeAddOp1(v, OP_IsNull, regRow);
      sqlite3VdbeAddOp4(v, OP_RegMakeRec, regRow, 1, regRow, &p->affinity, 1);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRow);
      sqlite3VdbeJumpHere(v, j1);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_Move, regRow, iParm);
................................................................................
          if( pCol->iSorterColumn>=j ){
            sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable,
                                     j + regBase);
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.403 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3VdbeAddOp2(v, OP_Move, regData, regBase+nExpr+1);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    int iLimit;
    if( pSelect->pOffset ){
................................................................................
  int iMem           /* First element */
){
  Vdbe *v;
  int r1;

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

/*
** Generate an error message when a SELECT is used within a subexpression
................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
#ifndef SQLITE_OMIT_COMPOUND_SELECT
    case SRT_Union: {
      sqlite3VdbeAddOp2(v, OP_MakeRecord, iMem, nColumn);
      if( aff ){
        sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      }
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      break;
    }

    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp2(v, OP_MakeRecord, iMem, nColumn);
      sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp2(v, OP_Delete, iParm, 0);
      break;
    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_EphemTab: {
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, nColumn, r1);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p, r1);
      }else{
        int r2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
................................................................................
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        pushOntoSorter(pParse, pOrderBy, p, iMem);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, iMem, 1, r1, &p->affinity, 1);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

................................................................................
    ** case of a subroutine, the subroutine itself is responsible for
    ** popping the data from the stack.
    */
    case SRT_Subroutine:
    case SRT_Callback: {
      if( pOrderBy ){
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, nColumn, r1);
        pushOntoSorter(pParse, pOrderBy, p, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }else if( eDest==SRT_Subroutine ){
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, iMem, nColumn);
      }
................................................................................
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      int j1;
      assert( nColumn==1 );
      j1 = sqlite3VdbeAddOp1(v, OP_IsNull, regRow);
      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRow, &p->affinity, 1);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRow);
      sqlite3VdbeJumpHere(v, j1);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_Move, regRow, iParm);
................................................................................
          if( pCol->iSorterColumn>=j ){
            sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable,
                                     j + regBase);
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.649 2008/01/12 19:03:49 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
................................................................................
  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

void sqlite3StrAccumAppend(StrAccum*,const char*,int);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumReset(StrAccum*);
int sqlite3StackToReg(Parse *, int);
void sqlite3SelectDestInit(SelectDest*,int,int);

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

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.650 2008/01/17 02:36:28 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
................................................................................
  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

void sqlite3StrAccumAppend(StrAccum*,const char*,int);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumReset(StrAccum*);

void sqlite3SelectDestInit(SelectDest*,int,int);

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

  /* Generate code to destroy the database record of the trigger.
  */
  assert( pTable!=0 );
  if( (v = sqlite3GetVdbe(pParse))!=0 ){
    int base;
    static const VdbeOpList dropTrigger[] = {
      { OP_Rewind,     0, ADDR(9),  0},
      { OP_String8,    0, 0,        0}, /* 1 */
      { OP_Column,     0, 1,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_String8,    0, 0,        0}, /* 4: "trigger" */
      { OP_Column,     0, 0,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);

  /* Generate code to destroy the database record of the trigger.
  */
  assert( pTable!=0 );
  if( (v = sqlite3GetVdbe(pParse))!=0 ){
    int base;
    static const VdbeOpList dropTrigger[] = {
      { OP_Rewind,     0, ADDR(9),  0},
      { OP_String8,    0, 1,        0}, /* 1 */
      { OP_Column,     0, 1,        2},
      { OP_Ne,         2, ADDR(8),  1},
      { OP_String8,    0, 1,        0}, /* 4: "trigger" */
      { OP_Column,     0, 0,        2},
      { OP_Ne,         2, ADDR(8),  1},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.167 2008/01/10 23:50:11 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
        }else{
          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr, regCols+i);
        }
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i);
      }
    }
    sqlite3VdbeAddOp3(v, OP_RegMakeRec, regCols, pTab->nCol, regRow);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);
    if( pParse->nErr ) goto update_cleanup;
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRow, regRowid);
    sqlite3ReleaseTempReg(pParse, regRowid);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.168 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
        }else{
          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr, regCols+i);
        }
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i);
      }
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRow);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);
    if( pParse->nErr ) goto update_cleanup;
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRow, regRowid);
    sqlite3ReleaseTempReg(pParse, regRowid);

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.696 2008/01/16 17:46:38 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  if( c ){
    pc = pOp->p2-1;
  }
  break;
}

/* Opcode: StackIsNull P1 P2 *
**
** Check the top of the stack and jump to P2 if the top of the stack
** is NULL.  If P1 is positive, then pop P1 elements from the stack
** regardless of whether or not the jump is taken.  If P1 is negative,
** pop -P1 elements from the stack only if the jump is taken and leave
** the stack unchanged if the jump is not taken.
*/
case OP_StackIsNull: {            /* no-push, jump */
  if( pTos->flags & MEM_Null ){
    pc = pOp->p2-1;
    if( pOp->p1<0 ){
      popStack(&pTos, -pOp->p1);
    }
  }
  if( pOp->p1>0 ){
    popStack(&pTos, pOp->p1);
  }
  break;
}

/* Opcode: IsNull P1 P2 P3 * *
**
** Jump to P2 if the value in register P1 is NULL.  If P3 is greater
** than zero, then check all values reg(P1), reg(P1+1), 
** reg(P1+2), ..., reg(P1+P3-1).
**
** If P1 is 0 then use the top of the stack instead of a register
................................................................................

op_column_out:
  UPDATE_MAX_BLOBSIZE(pDest);
  REGISTER_TRACE(pOp->p3, pDest);
  break;
}

/* Opcode: MakeRecord P1 P2 P4
**
** Convert the top abs(P1) entries of the stack into a single entry
** suitable for use as a data record in a database table or as a key
** in an index.  The details of the format are irrelavant as long as
** the OP_Column opcode can decode the record later and as long as the
** sqlite3VdbeRecordCompare function will correctly compare two encoded
** records.  Refer to source code comments for the details of the record
** format.
**
** The original stack entries are popped from the stack if P1>0 but
** remain on the stack if P1<0.
**
** If P2 is not zero and one or more of the entries are NULL, then jump
** to the address given by P2.  This feature can be used to skip a
** uniqueness test on indices.
**
** P4 may be a string that is P1 characters long.  The nth character of the
** string indicates the column affinity that should be used for the nth
** field of the index key (i.e. the first character of P4 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity NONE.
*/
/*
** Opcode: RegMakeRec P1 P2 P3 P4 *
**
** Builds a record like OP_MakeRecord.  But the data is taken from
** P2 registers beginning with P1:  P1, P1+1, P1+2, ..., P1+P2-1.
** The result is written into P3 or pushed onto the stack if P3 is zero.
** There is no jump on NULL - that can be done with a separate
** OP_AnyNull opcode.
*/
case OP_RegMakeRec:
case OP_MakeRecord: {        /* jump */
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
................................................................................
  Mem *pRec;             /* The new record */
  u64 nData = 0;         /* Number of bytes of data space */
  int nHdr = 0;          /* Number of bytes of header space */
  u64 nByte = 0;         /* Data space required for this record */
  int nZero = 0;         /* Number of zero bytes at the end of the record */
  int nVarint;           /* Number of bytes in a varint */
  u32 serial_type;       /* Type field */
  int containsNull = 0;  /* True if any of the data fields are NULL */
  Mem *pData0;           /* Bottom of the stack */
  Mem *pLast;            /* Top of the stack */
  int leaveOnStack;      /* If true, leave the entries on the stack */
  int nField;            /* Number of fields in the record */
  int jumpIfNull;        /* Jump here if non-zero and any entries are NULL. */
  char *zAffinity;       /* The affinity string for the record */
  int file_format;       /* File format to use for encoding */
  int i;                 /* Space used in zNewRecord[] */
  char zTemp[NBFS];      /* Space to hold small records */

  if( pOp->p1<0 ){
    assert( pOp->opcode==OP_MakeRecord );
    leaveOnStack = 1;
    nField = -pOp->p1;
  }else{
    leaveOnStack = 0;
    nField = pOp->p1;
  }
  zAffinity = pOp->p4.z;

  if( pOp->opcode==OP_RegMakeRec ){
    assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem );
    pData0 = &p->aMem[nField];
    nField = pOp->p2;
    leaveOnStack = 1;
    jumpIfNull = 0;
    pLast = &pData0[nField-1];
  }else{
    jumpIfNull = pOp->p2;
    pData0 = &pTos[1-nField];
    pLast = pTos;
    assert( pData0>=p->aStack );
  }
  containsNull = 0;
  file_format = p->minWriteFileFormat;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  for(pRec=pData0; pRec<=pLast; pRec++){
    int len;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
    }
    if( pRec->flags&MEM_Null ){
      containsNull = 1;
    }
    if( pRec->flags&MEM_Zero && pRec->n>0 ){
      ExpandBlob(pRec);
    }
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    len = sqlite3VdbeSerialTypeLen(serial_type);
    nData += len;
    nHdr += sqlite3VarintLen(serial_type);
................................................................................
    i += sqlite3PutVarint(&zNewRecord[i], serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
  }
  assert( i==nByte );

  /* Pop entries off the stack if required. Push the new record on. */
  if( !leaveOnStack ){
    popStack(&pTos, nField);
  }
  if( pOp->p3==0 ){
    pOut = ++pTos;
  }else{
    pOut = &p->aMem[pOp->p3];
    Release(pOut);
  }
  pOut->n = nByte;
................................................................................
  if( nZero ){
    pOut->u.i = nZero;
    pOut->flags |= MEM_Zero;
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
  REGISTER_TRACE(pOp->p3, pOut);
  UPDATE_MAX_BLOBSIZE(pOut);

  /* If a NULL was encountered and jumpIfNull is non-zero, take the jump. */
  if( jumpIfNull && containsNull ){
    pc = jumpIfNull - 1;
  }
  break;
}

/* Opcode: Statement P1 * * * *
**
** Begin an individual statement transaction which is part of a larger
** BEGIN..COMMIT transaction.  This is needed so that the statement

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.697 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  if( c ){
    pc = pOp->p2-1;
  }
  break;
}






















/* Opcode: IsNull P1 P2 P3 * *
**
** Jump to P2 if the value in register P1 is NULL.  If P3 is greater
** than zero, then check all values reg(P1), reg(P1+1), 
** reg(P1+2), ..., reg(P1+P3-1).
**
** If P1 is 0 then use the top of the stack instead of a register
................................................................................

op_column_out:
  UPDATE_MAX_BLOBSIZE(pDest);
  REGISTER_TRACE(pOp->p3, pDest);
  break;
}

/* Opcode: MakeRecord P1 P2 P3 P4 *
**
** Convert P2 registers beginning with P1 into a single entry
** suitable for use as a data record in a database table or as a key
** in an index.  The details of the format are irrelavant as long as
** the OP_Column opcode can decode the record later and as long as the
** sqlite3VdbeRecordCompare function will correctly compare two encoded
** records.  Refer to source code comments for the details of the record
** format.
**







** P4 may be a string that is P1 characters long.  The nth character of the
** string indicates the column affinity that should be used for the nth
** field of the index key (i.e. the first character of P4 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity NONE.
*/










case OP_MakeRecord: {
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
................................................................................
  Mem *pRec;             /* The new record */
  u64 nData = 0;         /* Number of bytes of data space */
  int nHdr = 0;          /* Number of bytes of header space */
  u64 nByte = 0;         /* Data space required for this record */
  int nZero = 0;         /* Number of zero bytes at the end of the record */
  int nVarint;           /* Number of bytes in a varint */
  u32 serial_type;       /* Type field */

  Mem *pData0;           /* First field to be combined into the record */
  Mem *pLast;            /* Last field of the record */

  int nField;            /* Number of fields in the record */

  char *zAffinity;       /* The affinity string for the record */
  int file_format;       /* File format to use for encoding */
  int i;                 /* Space used in zNewRecord[] */
  char zTemp[NBFS];      /* Space to hold small records */







  nField = pOp->p1;

  zAffinity = pOp->p4.z;


  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem );
  pData0 = &p->aMem[nField];
  nField = pOp->p2;


  pLast = &pData0[nField-1];







  file_format = p->minWriteFileFormat;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  for(pRec=pData0; pRec<=pLast; pRec++){
    int len;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
    }



    if( pRec->flags&MEM_Zero && pRec->n>0 ){
      ExpandBlob(pRec);
    }
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    len = sqlite3VdbeSerialTypeLen(serial_type);
    nData += len;
    nHdr += sqlite3VarintLen(serial_type);
................................................................................
    i += sqlite3PutVarint(&zNewRecord[i], serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
  }
  assert( i==nByte );





  if( pOp->p3==0 ){
    pOut = ++pTos;
  }else{
    pOut = &p->aMem[pOp->p3];
    Release(pOut);
  }
  pOut->n = nByte;
................................................................................
  if( nZero ){
    pOut->u.i = nZero;
    pOut->flags |= MEM_Zero;
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
  REGISTER_TRACE(pOp->p3, pOut);
  UPDATE_MAX_BLOBSIZE(pOut);





  break;
}

/* Opcode: Statement P1 * * * *
**
** Begin an individual statement transaction which is part of a larger
** BEGIN..COMMIT transaction.  This is needed so that the statement

#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP4;
  char zPtr[50];
  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-4s %.2X\n";
  if( pOut==0 ) pOut = stdout;
  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
  fprintf(pOut, zFormat1, pc, 
      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5);






  fflush(pOut);
}
#endif

/*
** Release an array of N Mem elements
*/

#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP4;
  char zPtr[50];
  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-4s %.2X %s\n";
  if( pOut==0 ) pOut = stdout;
  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
  fprintf(pOut, zFormat1, pc, 
      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
#ifdef SQLITE_DEBUG
      pOp->zComment ? pOp->zComment : ""
#else
      ""
#endif
  );
  fflush(pOut);
}
#endif

/*
** Release an array of N Mem elements
*/

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.281 2008/01/12 19:03:49 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
** to be probed is pIdx.  Pop the values from the stack and
** replace them all with a single record that is the index
** problem.
*/
static void buildIndexProbe(
  Vdbe *v,        /* Generate code into this VM */
  int nColumn,    /* The number of columns to check for NULL */
  Index *pIdx     /* Index that we will be searching */


){
  sqlite3VdbeAddOp2(v, OP_MakeRecord, nColumn, 0);



  sqlite3IndexAffinityStr(v, pIdx);
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
** coded.
**
** The current value for the constraint is left on the top of the stack.
**
** For a constraint of the form X=expr, the expression is evaluated and its
** result is left on the stack.  For constraints of the form X IN (...)
** this routine sets up a loop that will iterate over all values of X.
*/
static void codeEqualityTerm(
  Parse *pParse,      /* The parsing context */
  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
  WhereLevel *pLevel  /* When level of the FROM clause we are working on */

){
  Expr *pX = pTerm->pExpr;
  Vdbe *v = pParse->pVdbe;


  if( pX->op==TK_EQ ){
    sqlite3ExprCode(pParse, pX->pRight, 0);
  }else if( pX->op==TK_ISNULL ){
    sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
#ifndef SQLITE_OMIT_SUBQUERY
  }else{
    int eType;
    int iTab;
    struct InLoop *pIn;

    assert( pX->op==TK_IN );
................................................................................
      pLevel->nxt = sqlite3VdbeMakeLabel(v);
    }
    pLevel->nIn++;
    pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
                                    sizeof(pLevel->aInLoop[0])*pLevel->nIn);
    pIn = pLevel->aInLoop;
    if( pIn ){
      int op = ((eType==IN_INDEX_ROWID)?OP_Rowid:OP_Column);
      pIn += pLevel->nIn - 1;
      pIn->iCur = iTab;

      pIn->topAddr = sqlite3VdbeAddOp2(v, op, iTab, 0);



      sqlite3VdbeAddOp2(v, OP_StackIsNull, -1, 0);
    }else{
      pLevel->nIn = 0;
    }
#endif
  }
  disableTerm(pLevel, pTerm);
}
................................................................................
** This routine always allocates at least one memory cell and puts
** the address of that memory cell in pLevel->iMem.  The code that
** calls this routine will use pLevel->iMem to store the termination
** key value of the loop.  If one or more IN operators appear, then
** this routine allocates an additional nEq memory cells for internal
** use.
*/
static void codeAllEqualityTerms(
  Parse *pParse,        /* Parsing context */
  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
  WhereClause *pWC,     /* The WHERE clause */
  Bitmask notReady      /* Which parts of FROM have not yet been coded */

){
  int nEq = pLevel->nEq;        /* The number of == or IN constraints to code */
  int termsInMem = 0;           /* If true, store value in mem[] cells */
  Vdbe *v = pParse->pVdbe;      /* The virtual machine under construction */
  Index *pIdx = pLevel->pIdx;   /* The index being used for this loop */
  int iCur = pLevel->iTabCur;   /* The cursor of the table */
  WhereTerm *pTerm;             /* A single constraint term */
  int j;                        /* Loop counter */


  /* Figure out how many memory cells we will need then allocate them.
  ** We always need at least one used to store the loop terminator
  ** value.  If there are IN operators we'll need one for each == or
  ** IN constraint.
  */
  pLevel->iMem = ++pParse->nMem;
  if( pLevel->flags & WHERE_COLUMN_IN ){
    pParse->nMem += pLevel->nEq;
    termsInMem = 1;
  }

  /* Evaluate the equality constraints
  */
  assert( pIdx->nColumn>=nEq );
  for(j=0; j<nEq; j++){
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    if( pTerm==0 ) break;
    assert( (pTerm->flags & TERM_CODED)==0 );
    codeEqualityTerm(pParse, pTerm, pLevel);
    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
      sqlite3VdbeAddOp2(v, OP_StackIsNull, termsInMem ? -1 : -(j+1), pLevel->brk);
    }
    if( termsInMem ){
      sqlite3VdbeAddOp2(v, OP_Move, 0, pLevel->iMem+j+1);
    }
  }

  /* Make sure all the constraint values are on the top of the stack
  */
  if( termsInMem ){
    for(j=0; j<nEq; j++){
      sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem+j+1, 0);
    }
  }

}

#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
** overwrites the previous.  This information is used for testing and
................................................................................
      sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
      int nConstraint = pBestIdx->nConstraint;
      struct sqlite3_index_constraint_usage *aUsage =
                                                  pBestIdx->aConstraintUsage;
      const struct sqlite3_index_constraint *aConstraint =
                                                  pBestIdx->aConstraint;


      for(j=1; j<=nConstraint; j++){
        int k;
        for(k=0; k<nConstraint; k++){
          if( aUsage[k].argvIndex==j ){
            int iTerm = aConstraint[k].iTermOffset;
            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight, 0);
            break;
          }
        }
        if( k==nConstraint ) break;
      }
      iReg = ++pParse->nMem;
      pParse->nMem++;
      sqlite3StackToReg(pParse, j-1);
      sqlite3VdbeAddOp2(v, OP_Integer, pBestIdx->idxNum, iReg);
      sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
      sqlite3VdbeAddOp4(v, OP_VFilter, iCur, brk, iReg, pBestIdx->idxStr,
                        pBestIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);

      pBestIdx->needToFreeIdxStr = 0;
      for(j=0; j<pBestIdx->nConstraint; j++){
        if( aUsage[j].omit ){
          int iTerm = aConstraint[j].iTermOffset;
          disableTerm(pLevel, &wc.a[iTerm]);
        }
      }
................................................................................

    if( pLevel->flags & WHERE_ROWID_EQ ){
      /* Case 1:  We can directly reference a single row using an
      **          equality comparison against the ROWID field.  Or
      **          we reference multiple rows using a "rowid IN (...)"
      **          construct.
      */

      pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
      assert( pTerm!=0 );
      assert( pTerm->pExpr!=0 );
      assert( pTerm->leftCursor==iCur );
      assert( omitTable==0 );

      codeEqualityTerm(pParse, pTerm, pLevel);
      nxt = pLevel->nxt;
      sqlite3VdbeAddOp3(v, OP_MustBeInt, 0, nxt, 1);
      sqlite3VdbeAddOp2(v, OP_NotExists, iCur, nxt);
      VdbeComment((v, "pk"));

      pLevel->op = OP_Noop;
    }else if( pLevel->flags & WHERE_ROWID_RANGE ){
      /* Case 2:  We have an inequality comparison against the ROWID field.
      */
      int testOp = OP_Noop;
      int start;
      WhereTerm *pStart, *pEnd;
................................................................................
      if( bRev ){
        pTerm = pStart;
        pStart = pEnd;
        pEnd = pTerm;
      }
      if( pStart ){
        Expr *pX;

        pX = pStart->pExpr;
        assert( pX!=0 );
        assert( pStart->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight, 0);
        sqlite3VdbeAddOp3(v, OP_ForceInt, 0, brk, 
                             pX->op==TK_LE || pX->op==TK_GT);
        sqlite3VdbeAddOp2(v, bRev ? OP_MoveLt : OP_MoveGe, iCur, brk);
        VdbeComment((v, "pk"));

        disableTerm(pLevel, pStart);
      }else{
        sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, brk);
      }
      if( pEnd ){
        Expr *pX;
        pX = pEnd->pExpr;
        assert( pX!=0 );
        assert( pEnd->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight, 0);
        pLevel->iMem = ++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_Move, 0, pLevel->iMem);

        if( pX->op==TK_LT || pX->op==TK_GT ){
          testOp = bRev ? OP_Le : OP_Ge;
        }else{
          testOp = bRev ? OP_Lt : OP_Gt;
        }
        disableTerm(pLevel, pEnd);
      }
      start = sqlite3VdbeCurrentAddr(v);
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = start;
      if( testOp!=OP_Noop ){

        sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
        sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0);
        sqlite3VdbeAddOp2(v, testOp, 0, brk);
        sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);

      }
    }else if( pLevel->flags & WHERE_COLUMN_RANGE ){
      /* Case 3: The WHERE clause term that refers to the right-most
      **         column of the index is an inequality.  For example, if
      **         the index is on (x,y,z) and the WHERE clause is of the
      **         form "x=5 AND y<10" then this case is used.  Only the
      **         right-most column can be an inequality - the rest must
................................................................................
      int topEq=0;        /* True if top limit uses ==. False is strictly < */
      int btmEq=0;        /* True if btm limit uses ==. False if strictly > */
      int topOp, btmOp;   /* Operators for the top and bottom search bounds */
      int testOp;
      int topLimit = (pLevel->flags & WHERE_TOP_LIMIT)!=0;
      int btmLimit = (pLevel->flags & WHERE_BTM_LIMIT)!=0;
      int isMinQuery = 0;      /* If this is an optimized SELECT min(x) ... */



      /* Generate code to evaluate all constraint terms using == or IN
      ** and level the values of those terms on the stack.
      */
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);

      /* Duplicate the equality term values because they will all be
      ** used twice: once to make the termination key and once to make the
      ** start key.
      */
      for(j=0; j<nEq; j++){
        sqlite3VdbeAddOp1(v, OP_Copy, 1-nEq);
      }

      /* Figure out what comparison operators to use for top and bottom 
      ** search bounds. For an ascending index, the bottom bound is a > or >=
      ** operator and the top bound is a < or <= operator.  For a descending
      ** index the operators are reversed.
      */
      if( pIdx->aSortOrder[nEq]==SQLITE_SO_ASC ){
................................................................................
      **
      ** 2002-Dec-04: On a reverse-order scan, the so-called "termination"
      ** key computed here really ends up being the start key.
      */
      nxt = pLevel->nxt;
      if( topLimit ){
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, topOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight, 0);
        sqlite3VdbeAddOp2(v, OP_StackIsNull, -(nEq*2+1), nxt);
        topEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
        testOp = OP_IdxGE;
      }else{
        testOp = nEq>0 ? OP_IdxGE : OP_Noop;
        topEq = 1;
      }
      if( testOp!=OP_Noop || (isMinQuery&&bRev) ){
        int nCol = nEq + topLimit;
        pLevel->iMem = ++pParse->nMem;
        if( isMinQuery && !topLimit ){

          nCol++;
          sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
          topEq = 0;
        }
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp2(v, op, iIdxCur, nxt);
        }else{
          sqlite3VdbeAddOp2(v, OP_Move, 0, pLevel->iMem);
        }
      }else if( bRev ){
        sqlite3VdbeAddOp2(v, OP_Last, iIdxCur, brk);
      }
   
      /* Generate the start key.  This is the key that defines the lower
      ** bound on the search.  There is no start key if there are no
................................................................................
      ** start key search.
      **
      ** 2002-Dec-04: In the case of a reverse-order search, the so-called
      ** "start" key really ends up being used as the termination key.
      */
      if( btmLimit ){
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, btmOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight, 0);
        sqlite3VdbeAddOp2(v, OP_StackIsNull, -(nEq+1), nxt);
        btmEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
      }else{
        btmEq = 1;
      }
      if( nEq>0 || btmLimit || (isMinQuery&&!bRev) ){
        int nCol = nEq + btmLimit;
        if( isMinQuery && !btmLimit ){

          nCol++;
          sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
          btmEq = 0;
        }
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          pLevel->iMem = ++pParse->nMem;
          sqlite3VdbeAddOp2(v, OP_Move, 0, pLevel->iMem);
          testOp = OP_IdxLT;
        }else{




          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp2(v, op, iIdxCur, nxt);

        }
      }else if( bRev ){
        testOp = OP_Noop;
      }else{
        sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, brk);
      }

      /* Generate the the top of the loop.  If there is a termination
      ** key we have to test for that key and abort at the top of the
      ** loop.
      */
      start = sqlite3VdbeCurrentAddr(v);
      if( testOp!=OP_Noop ){
        sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0);
        sqlite3VdbeAddOp2(v, testOp, iIdxCur, nxt);
        if( (topEq && !bRev) || (!btmEq && bRev) ){
          sqlite3VdbeChangeP5(v, 1);
        }
      }

      if( topLimit | btmLimit ){
        sqlite3VdbeAddOp2(v, OP_Column, iIdxCur, nEq);
        sqlite3VdbeAddOp2(v, OP_StackIsNull, 1, cont);
      }
      if( !omitTable ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp2(v, OP_MoveGe, iCur, 0);
      }


      /* Record the instruction used to terminate the loop.
      */
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else if( pLevel->flags & WHERE_COLUMN_EQ ){
      /* Case 4:  There is an index and all terms of the WHERE clause that
      **          refer to the index using the "==" or "IN" operators.
      */
      int start;
      int nEq = pLevel->nEq;
      int isMinQuery = 0;      /* If this is an optimized SELECT min(x) ... */



      /* Generate code to evaluate all constraint terms using == or IN
      ** and leave the values of those terms on the stack.
      */
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);
      nxt = pLevel->nxt;

      if( (obflag==ORDERBY_MIN)
       && (pLevel->flags&WHERE_ORDERBY) 
       && (pIdx->nColumn>nEq)
       && (pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq])
      ){
        int h;
        isMinQuery = 1;
        for(h=0; h<nEq; h++){
          sqlite3VdbeAddOp1(v, OP_Copy, 1-nEq);
        }
        buildIndexProbe(v, nEq, pIdx);
        sqlite3VdbeAddOp2(v, OP_Move, 0, pLevel->iMem);
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);

        buildIndexProbe(v, nEq+1, pIdx);
      }else{
        /* Generate a single key that will be used to both start and 
        ** terminate the search
        */
        buildIndexProbe(v, nEq, pIdx);
        sqlite3VdbeAddOp2(v, OP_Copy, 0, pLevel->iMem);
      }

      /* Generate code (1) to move to the first matching element of the table.
      ** Then generate code (2) that jumps to "nxt" after the cursor is past
      ** the last matching element of the table.  The code (1) is executed
      ** once to initialize the search, the code (2) is executed before each
      ** iteration of the scan to see if the scan has finished. */
      if( bRev ){
        /* Scan in reverse order */
        sqlite3VdbeAddOp2(v, (isMinQuery?OP_MoveLt:OP_MoveLe), iIdxCur, nxt);
        start = sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0);





        sqlite3VdbeAddOp2(v, OP_IdxLT, iIdxCur, nxt);
        pLevel->op = OP_Prev;
      }else{
        /* Scan in the forward order */
        sqlite3VdbeAddOp2(v, (isMinQuery?OP_MoveGt:OP_MoveGe), iIdxCur, nxt);
        start = sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0);





        sqlite3VdbeAddOp2(v, OP_IdxGE, iIdxCur, nxt);
        sqlite3VdbeChangeP5(v, 1);
        pLevel->op = OP_Next;
      }
      if( !omitTable ){

        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp2(v, OP_MoveGe, iCur, 0);

      }
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else{
      /* Case 5:  There is no usable index.  We must do a complete
      **          scan of the entire table.
      */

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.282 2008/01/17 02:36:28 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
** to be probed is pIdx.  Pop the values from the stack and
** replace them all with a single record that is the index
** problem.
*/
static void buildIndexProbe(
  Vdbe *v,        /* Generate code into this VM */
  int nColumn,    /* The number of columns to check for NULL */
  Index *pIdx,    /* Index that we will be searching */
  int regSrc,     /* Take values from this register */
  int regDest     /* Write the result into this register */
){

  assert( regSrc>0 );
  assert( regDest>0 );
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regSrc, nColumn, regDest);
  sqlite3IndexAffinityStr(v, pIdx);
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
** coded.
**
** The current value for the constraint is left in register iReg.
**
** For a constraint of the form X=expr, the expression is evaluated and its
** result is left on the stack.  For constraints of the form X IN (...)
** this routine sets up a loop that will iterate over all values of X.
*/
static void codeEqualityTerm(
  Parse *pParse,      /* The parsing context */
  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
  WhereLevel *pLevel, /* When level of the FROM clause we are working on */
  int iReg            /* Leave results in this register */
){
  Expr *pX = pTerm->pExpr;
  Vdbe *v = pParse->pVdbe;

  assert( iReg>0 && iReg<=pParse->nMem );
  if( pX->op==TK_EQ ){
    sqlite3ExprCode(pParse, pX->pRight, iReg);
  }else if( pX->op==TK_ISNULL ){
    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
#ifndef SQLITE_OMIT_SUBQUERY
  }else{
    int eType;
    int iTab;
    struct InLoop *pIn;

    assert( pX->op==TK_IN );
................................................................................
      pLevel->nxt = sqlite3VdbeMakeLabel(v);
    }
    pLevel->nIn++;
    pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
                                    sizeof(pLevel->aInLoop[0])*pLevel->nIn);
    pIn = pLevel->aInLoop;
    if( pIn ){

      pIn += pLevel->nIn - 1;
      pIn->iCur = iTab;
      if( eType==IN_INDEX_ROWID ){
        pIn->topAddr = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
      }else{
        pIn->topAddr = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
      }
      sqlite3VdbeAddOp1(v, OP_IsNull, iReg);
    }else{
      pLevel->nIn = 0;
    }
#endif
  }
  disableTerm(pLevel, pTerm);
}
................................................................................
** This routine always allocates at least one memory cell and puts
** the address of that memory cell in pLevel->iMem.  The code that
** calls this routine will use pLevel->iMem to store the termination
** key value of the loop.  If one or more IN operators appear, then
** this routine allocates an additional nEq memory cells for internal
** use.
*/
static int codeAllEqualityTerms(
  Parse *pParse,        /* Parsing context */
  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
  WhereClause *pWC,     /* The WHERE clause */
  Bitmask notReady,     /* Which parts of FROM have not yet been coded */
  int nExtraReg         /* Number of extra registers to allocate */
){
  int nEq = pLevel->nEq;        /* The number of == or IN constraints to code */

  Vdbe *v = pParse->pVdbe;      /* The virtual machine under construction */
  Index *pIdx = pLevel->pIdx;   /* The index being used for this loop */
  int iCur = pLevel->iTabCur;   /* The cursor of the table */
  WhereTerm *pTerm;             /* A single constraint term */
  int j;                        /* Loop counter */
  int regBase;                  /* Base register */

  /* Figure out how many memory cells we will need then allocate them.
  ** We always need at least one used to store the loop terminator
  ** value.  If there are IN operators we'll need one for each == or
  ** IN constraint.
  */
  pLevel->iMem = pParse->nMem + 1;
  regBase = pParse->nMem + 2;
  pParse->nMem += pLevel->nEq + 2 + nExtraReg;



  /* Evaluate the equality constraints
  */
  assert( pIdx->nColumn>=nEq );
  for(j=0; j<nEq; j++){
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    if( pTerm==0 ) break;
    assert( (pTerm->flags & TERM_CODED)==0 );
    codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){



      sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->brk);
    }
  }








  return regBase;
}

#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
** overwrites the previous.  This information is used for testing and
................................................................................
      sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
      int nConstraint = pBestIdx->nConstraint;
      struct sqlite3_index_constraint_usage *aUsage =
                                                  pBestIdx->aConstraintUsage;
      const struct sqlite3_index_constraint *aConstraint =
                                                  pBestIdx->aConstraint;

      iReg = sqlite3GetTempRange(pParse, nConstraint+2);
      for(j=1; j<=nConstraint; j++){
        int k;
        for(k=0; k<nConstraint; k++){
          if( aUsage[k].argvIndex==j ){
            int iTerm = aConstraint[k].iTermOffset;
            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight, iReg+j+1);
            break;
          }
        }
        if( k==nConstraint ) break;
      }



      sqlite3VdbeAddOp2(v, OP_Integer, pBestIdx->idxNum, iReg);
      sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
      sqlite3VdbeAddOp4(v, OP_VFilter, iCur, brk, iReg, pBestIdx->idxStr,
                        pBestIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
      sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
      pBestIdx->needToFreeIdxStr = 0;
      for(j=0; j<pBestIdx->nConstraint; j++){
        if( aUsage[j].omit ){
          int iTerm = aConstraint[j].iTermOffset;
          disableTerm(pLevel, &wc.a[iTerm]);
        }
      }
................................................................................

    if( pLevel->flags & WHERE_ROWID_EQ ){
      /* Case 1:  We can directly reference a single row using an
      **          equality comparison against the ROWID field.  Or
      **          we reference multiple rows using a "rowid IN (...)"
      **          construct.
      */
      int r1;
      pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
      assert( pTerm!=0 );
      assert( pTerm->pExpr!=0 );
      assert( pTerm->leftCursor==iCur );
      assert( omitTable==0 );
      r1 = sqlite3GetTempReg(pParse);
      codeEqualityTerm(pParse, pTerm, pLevel, r1);
      nxt = pLevel->nxt;
      sqlite3VdbeAddOp3(v, OP_MustBeInt, r1, nxt, 1);
      sqlite3VdbeAddOp3(v, OP_NotExists, iCur, nxt, r1);
      VdbeComment((v, "pk"));
      sqlite3ReleaseTempReg(pParse, r1);
      pLevel->op = OP_Noop;
    }else if( pLevel->flags & WHERE_ROWID_RANGE ){
      /* Case 2:  We have an inequality comparison against the ROWID field.
      */
      int testOp = OP_Noop;
      int start;
      WhereTerm *pStart, *pEnd;
................................................................................
      if( bRev ){
        pTerm = pStart;
        pStart = pEnd;
        pEnd = pTerm;
      }
      if( pStart ){
        Expr *pX;
        int r1, regFree1;
        pX = pStart->pExpr;
        assert( pX!=0 );
        assert( pStart->leftCursor==iCur );
        r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &regFree1);
        sqlite3VdbeAddOp3(v, OP_ForceInt, r1, brk, 
                             pX->op==TK_LE || pX->op==TK_GT);
        sqlite3VdbeAddOp3(v, bRev ? OP_MoveLt : OP_MoveGe, iCur, brk, r1);
        VdbeComment((v, "pk"));
        sqlite3ReleaseTempReg(pParse, regFree1);
        disableTerm(pLevel, pStart);
      }else{
        sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, brk);
      }
      if( pEnd ){
        Expr *pX;
        pX = pEnd->pExpr;
        assert( pX!=0 );
        assert( pEnd->leftCursor==iCur );

        pLevel->iMem = ++pParse->nMem;

        sqlite3ExprCode(pParse, pX->pRight, pLevel->iMem);
        if( pX->op==TK_LT || pX->op==TK_GT ){
          testOp = bRev ? OP_Le : OP_Ge;
        }else{
          testOp = bRev ? OP_Lt : OP_Gt;
        }
        disableTerm(pLevel, pEnd);
      }
      start = sqlite3VdbeCurrentAddr(v);
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = start;
      if( testOp!=OP_Noop ){
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);
        /* sqlite3VdbeAddOp2(v, OP_SCopy, pLevel->iMem, 0); */
        sqlite3VdbeAddOp3(v, testOp, pLevel->iMem, brk, r1);
        sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
        sqlite3ReleaseTempReg(pParse, r1);
      }
    }else if( pLevel->flags & WHERE_COLUMN_RANGE ){
      /* Case 3: The WHERE clause term that refers to the right-most
      **         column of the index is an inequality.  For example, if
      **         the index is on (x,y,z) and the WHERE clause is of the
      **         form "x=5 AND y<10" then this case is used.  Only the
      **         right-most column can be an inequality - the rest must
................................................................................
      int topEq=0;        /* True if top limit uses ==. False is strictly < */
      int btmEq=0;        /* True if btm limit uses ==. False if strictly > */
      int topOp, btmOp;   /* Operators for the top and bottom search bounds */
      int testOp;
      int topLimit = (pLevel->flags & WHERE_TOP_LIMIT)!=0;
      int btmLimit = (pLevel->flags & WHERE_BTM_LIMIT)!=0;
      int isMinQuery = 0;      /* If this is an optimized SELECT min(x) ... */
      int regBase;        /* Base register holding constraint values */
      int r1;             /* Temp register */

      /* Generate code to evaluate all constraint terms using == or IN
      ** and level the values of those terms on the stack.
      */
      regBase = codeAllEqualityTerms(pParse, pLevel, &wc, notReady, 2);









      /* Figure out what comparison operators to use for top and bottom 
      ** search bounds. For an ascending index, the bottom bound is a > or >=
      ** operator and the top bound is a < or <= operator.  For a descending
      ** index the operators are reversed.
      */
      if( pIdx->aSortOrder[nEq]==SQLITE_SO_ASC ){
................................................................................
      **
      ** 2002-Dec-04: On a reverse-order scan, the so-called "termination"
      ** key computed here really ends up being the start key.
      */
      nxt = pLevel->nxt;
      if( topLimit ){
        Expr *pX;
        int k = pIdx->aiColumn[nEq];
        pTerm = findTerm(&wc, iCur, k, notReady, topOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight, regBase+nEq);
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt);
        topEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
        testOp = OP_IdxGE;
      }else{
        testOp = nEq>0 ? OP_IdxGE : OP_Noop;
        topEq = 1;
      }
      if( testOp!=OP_Noop || (isMinQuery&&bRev) ){
        int nCol = nEq + topLimit;

        if( isMinQuery && !topLimit ){
          sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nCol);
          nCol++;

          topEq = 0;
        }
        buildIndexProbe(v, nCol, pIdx, regBase, pLevel->iMem);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, pLevel->iMem);


        }
      }else if( bRev ){
        sqlite3VdbeAddOp2(v, OP_Last, iIdxCur, brk);
      }
   
      /* Generate the start key.  This is the key that defines the lower
      ** bound on the search.  There is no start key if there are no
................................................................................
      ** start key search.
      **
      ** 2002-Dec-04: In the case of a reverse-order search, the so-called
      ** "start" key really ends up being used as the termination key.
      */
      if( btmLimit ){
        Expr *pX;
        int k = pIdx->aiColumn[nEq];
        pTerm = findTerm(&wc, iCur, k, notReady, btmOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight, regBase+nEq);
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt);
        btmEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
      }else{
        btmEq = 1;
      }
      if( nEq>0 || btmLimit || (isMinQuery&&!bRev) ){
        int nCol = nEq + btmLimit;
        if( isMinQuery && !btmLimit ){
          sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nCol);
          nCol++;

          btmEq = 0;
        }

        if( bRev ){
          r1 = pLevel->iMem;

          testOp = OP_IdxLT;
        }else{
          r1 = sqlite3GetTempReg(pParse);
        }
        buildIndexProbe(v, nCol, pIdx, regBase, r1);
        if( !bRev ){
          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, r1);
          sqlite3ReleaseTempReg(pParse, r1);
        }
      }else if( bRev ){
        testOp = OP_Noop;
      }else{
        sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, brk);
      }

      /* Generate the the top of the loop.  If there is a termination
      ** key we have to test for that key and abort at the top of the
      ** loop.
      */
      start = sqlite3VdbeCurrentAddr(v);
      if( testOp!=OP_Noop ){

        sqlite3VdbeAddOp3(v, testOp, iIdxCur, nxt, pLevel->iMem);
        if( (topEq && !bRev) || (!btmEq && bRev) ){
          sqlite3VdbeChangeP5(v, 1);
        }
      }
      r1 = sqlite3GetTempReg(pParse);
      if( topLimit | btmLimit ){
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
        sqlite3VdbeAddOp2(v, OP_IsNull, r1, cont);
      }
      if( !omitTable ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1);
        sqlite3VdbeAddOp3(v, OP_MoveGe, iCur, 0, r1);
      }
      sqlite3ReleaseTempReg(pParse, r1);

      /* Record the instruction used to terminate the loop.
      */
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else if( pLevel->flags & WHERE_COLUMN_EQ ){
      /* Case 4:  There is an index and all terms of the WHERE clause that
      **          refer to the index using the "==" or "IN" operators.
      */
      int start;
      int nEq = pLevel->nEq;
      int isMinQuery = 0;      /* If this is an optimized SELECT min(x) ... */
      int regBase;             /* Base register of array holding constraints */
      int r1;

      /* Generate code to evaluate all constraint terms using == or IN
      ** and leave the values of those terms on the stack.
      */
      regBase = codeAllEqualityTerms(pParse, pLevel, &wc, notReady, 1);
      nxt = pLevel->nxt;

      if( (obflag==ORDERBY_MIN)
       && (pLevel->flags&WHERE_ORDERBY) 
       && (pIdx->nColumn>nEq)
       && (pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq])
      ){

        isMinQuery = 1;



        buildIndexProbe(v, nEq, pIdx, regBase, pLevel->iMem);

        sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
        r1 = ++pParse->nMem;
        buildIndexProbe(v, nEq+1, pIdx, regBase, r1);
      }else{
        /* Generate a single key that will be used to both start and 
        ** terminate the search
        */
        r1 = pLevel->iMem;
        buildIndexProbe(v, nEq, pIdx, regBase, r1);
      }

      /* Generate code (1) to move to the first matching element of the table.
      ** Then generate code (2) that jumps to "nxt" after the cursor is past
      ** the last matching element of the table.  The code (1) is executed
      ** once to initialize the search, the code (2) is executed before each
      ** iteration of the scan to see if the scan has finished. */
      if( bRev ){
        /* Scan in reverse order */
        int op;
        if( isMinQuery ){
          op = OP_MoveLt;
        }else{
          op = OP_MoveLe;
        }
        sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, r1);
        start = sqlite3VdbeAddOp3(v, OP_IdxLT, iIdxCur, nxt, pLevel->iMem);
        pLevel->op = OP_Prev;
      }else{
        /* Scan in the forward order */
        int op;
        if( isMinQuery ){
          op = OP_MoveGt;
        }else{
          op = OP_MoveGe;
        }
        sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, r1);
        start = sqlite3VdbeAddOp3(v, OP_IdxGE, iIdxCur, nxt, pLevel->iMem);
        sqlite3VdbeChangeP5(v, 1);
        pLevel->op = OP_Next;
      }
      if( !omitTable ){
        r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1);
        sqlite3VdbeAddOp3(v, OP_MoveGe, iCur, 0, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else{
      /* Case 5:  There is no usable index.  We must do a complete
      **          scan of the entire table.
      */

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements some common TCL routines used for regression
# testing the SQLite library
#
# $Id: tester.tcl,v 1.100 2008/01/16 17:46:38 drh Exp $


set tcl_precision 15
set sqlite_pending_byte 0x0010000

# 
# Check the command-line arguments for a default soft-heap-limit.
................................................................................
  return $cksum
}

# Generate a checksum based on the contents of the main and temp tables
# database $db. If the checksum of two databases is the same, and the
# integrity-check passes for both, the two databases are identical.
#
proc allcksum {db} {
  set ret [list]
  ifcapable tempdb {
    set sql {
      SELECT name FROM sqlite_master WHERE type = 'table' UNION
      SELECT name FROM sqlite_temp_master WHERE type = 'table' UNION
      SELECT 'sqlite_master' UNION
      SELECT 'sqlite_temp_master' ORDER BY 1

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements some common TCL routines used for regression
# testing the SQLite library
#
# $Id: tester.tcl,v 1.101 2008/01/17 02:36:28 drh Exp $


set tcl_precision 15
set sqlite_pending_byte 0x0010000

# 
# Check the command-line arguments for a default soft-heap-limit.
................................................................................
  return $cksum
}

# Generate a checksum based on the contents of the main and temp tables
# database $db. If the checksum of two databases is the same, and the
# integrity-check passes for both, the two databases are identical.
#
proc allcksum {{db db}} {
  set ret [list]
  ifcapable tempdb {
    set sql {
      SELECT name FROM sqlite_master WHERE type = 'table' UNION
      SELECT name FROM sqlite_temp_master WHERE type = 'table' UNION
      SELECT 'sqlite_master' UNION
      SELECT 'sqlite_temp_master' ORDER BY 1

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the VACUUM statement.
#
# $Id: vacuum.test,v 1.39 2008/01/16 17:46:38 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If the VACUUM statement is disabled in the current build, skip all
# the tests in this file.
#
................................................................................
    CREATE INDEX i1 ON t1(b,c);
    CREATE UNIQUE INDEX i2 ON t1(c,a);
    CREATE TABLE t2 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t2;
  }
  set ::size1 [file size test.db]
  set ::cksum [allcksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.2 {
  execsql {
    VACUUM;
  }
  allcksum
} $cksum
ifcapable vacuum {
  do_test vacuum-1.3 {
    expr {[file size test.db]<$::size1}
  } {1}
}
do_test vacuum-1.4 {
................................................................................
    regsub {CREATE VIEW} $sql_script {-- CREATE VIEW} sql_script
  }
  ifcapable !trigger {
    regsub {CREATE TRIGGER} $sql_script {-- CREATE TRIGGER} sql_script
  }
  execsql $sql_script
  set ::size1 [file size test.db]
  set ::cksum [allcksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.5 {
  execsql {
    VACUUM;
  }
  allcksum
} $cksum

ifcapable vacuum {
  do_test vacuum-1.6 {
    expr {[file size test.db]<$::size1}
  } {1}
}
................................................................................
    BEGIN;
    CREATE TABLE t4 AS SELECT * FROM t1;
    CREATE TABLE t5 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t4;
    DROP TABLE t5;
  } db2
  set ::cksum [allcksum db2]
  catchsql {
    VACUUM
  }
} {0 {}}
do_test vacuum-2.3 {
  allcksum
} $cksum
do_test vacuum-2.4 {
  catch {db2 eval {SELECT count(*) FROM sqlite_master}}
  allcksum db2
} $cksum

# Make sure the schema cookie is incremented by vacuum.
#
do_test vacuum-2.5 {
  execsql {
    BEGIN;
................................................................................
    execsql {
      DROP TABLE 'abc abc';
      CREATE TABLE autoinc(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
      INSERT INTO autoinc(b) VALUES('hi');
      INSERT INTO autoinc(b) VALUES('there');
      DELETE FROM autoinc;
    }
    set ::cksum [allcksum]
    expr {$::cksum!=""}
  } {1}
  do_test vacuum-9.2 {
    execsql {
      VACUUM;
    }
    allcksum
  } $::cksum
  do_test vacuum-9.3 {
    execsql {
      INSERT INTO autoinc(b) VALUES('one');
      INSERT INTO autoinc(b) VALUES('two');
    }
    set ::cksum [allcksum]
    expr {$::cksum!=""}
  } {1}
  do_test vacuum-9.4 {
    execsql {
      VACUUM;
    }
    allcksum
  } $::cksum
}

file delete -force {a'z.db}

finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the VACUUM statement.
#
# $Id: vacuum.test,v 1.40 2008/01/17 02:36:28 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If the VACUUM statement is disabled in the current build, skip all
# the tests in this file.
#
................................................................................
    CREATE INDEX i1 ON t1(b,c);
    CREATE UNIQUE INDEX i2 ON t1(c,a);
    CREATE TABLE t2 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t2;
  }
  set ::size1 [file size test.db]
  set ::cksum [cksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.2 {
  execsql {
    VACUUM;
  }
  cksum
} $cksum
ifcapable vacuum {
  do_test vacuum-1.3 {
    expr {[file size test.db]<$::size1}
  } {1}
}
do_test vacuum-1.4 {
................................................................................
    regsub {CREATE VIEW} $sql_script {-- CREATE VIEW} sql_script
  }
  ifcapable !trigger {
    regsub {CREATE TRIGGER} $sql_script {-- CREATE TRIGGER} sql_script
  }
  execsql $sql_script
  set ::size1 [file size test.db]
  set ::cksum [cksum]
  expr {$::cksum!=""}
} {1}
do_test vacuum-1.5 {
  execsql {
    VACUUM;
  }
  cksum
} $cksum

ifcapable vacuum {
  do_test vacuum-1.6 {
    expr {[file size test.db]<$::size1}
  } {1}
}
................................................................................
    BEGIN;
    CREATE TABLE t4 AS SELECT * FROM t1;
    CREATE TABLE t5 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t4;
    DROP TABLE t5;
  } db2
  set ::cksum [cksum db2]
  catchsql {
    VACUUM
  }
} {0 {}}
do_test vacuum-2.3 {
  cksum
} $cksum
do_test vacuum-2.4 {
  catch {db2 eval {SELECT count(*) FROM sqlite_master}}
  cksum db2
} $cksum

# Make sure the schema cookie is incremented by vacuum.
#
do_test vacuum-2.5 {
  execsql {
    BEGIN;
................................................................................
    execsql {
      DROP TABLE 'abc abc';
      CREATE TABLE autoinc(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
      INSERT INTO autoinc(b) VALUES('hi');
      INSERT INTO autoinc(b) VALUES('there');
      DELETE FROM autoinc;
    }
    set ::cksum [cksum]
    expr {$::cksum!=""}
  } {1}
  do_test vacuum-9.2 {
    execsql {
      VACUUM;
    }
    cksum
  } $::cksum
  do_test vacuum-9.3 {
    execsql {
      INSERT INTO autoinc(b) VALUES('one');
      INSERT INTO autoinc(b) VALUES('two');
    }
    set ::cksum [cksum]
    expr {$::cksum!=""}
  } {1}
  do_test vacuum-9.4 {
    execsql {
      VACUUM;
    }
    cksum
  } $::cksum
}

file delete -force {a'z.db}

finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the VACUUM statement.
#
# $Id: vacuum2.test,v 1.6 2008/01/16 17:46:38 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If the VACUUM statement is disabled in the current build, skip all
# the tests in this file.
#
................................................................................
do_test vacuum2-3.1 {
  execsql {
    INSERT INTO t1 VALUES('hello');
    INSERT INTO t2 VALUES('out there');
  }
  expr {[file size test.db]/$pageSize}
} {3}
set cksum [allcksum]
do_test vacuum2-3.2 {
  allcksum db2
} $cksum

# Convert the database to an autovacuumed database.
do_test vacuum2-3.3 {
  execsql {
    PRAGMA auto_vacuum=FULL;
    VACUUM;
  }
  expr {[file size test.db]/$pageSize}
} {4}
do_test vacuum2-3.4 {
  allcksum db2
} $cksum
do_test vacuum2-3.5 {
  allcksum
} $cksum
do_test vacuum2-3.6 {
  execsql {PRAGMA integrity_check} db2
} {ok}
do_test vacuum2-3.7 {
  execsql {PRAGMA integrity_check} db
} {ok}
................................................................................
  execsql {
    PRAGMA auto_vacuum=NONE;
    VACUUM;
  }
  expr {[file size test.db]/$pageSize}
} {3}
do_test vacuum2-3.14 {
  allcksum db2
} $cksum
do_test vacuum2-3.15 {
  allcksum
} $cksum
do_test vacuum2-3.16 {
  execsql {PRAGMA integrity_check} db2
} {ok}
do_test vacuum2-3.17 {
  execsql {PRAGMA integrity_check} db
} {ok}

db2 close

finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the VACUUM statement.
#
# $Id: vacuum2.test,v 1.7 2008/01/17 02:36:28 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If the VACUUM statement is disabled in the current build, skip all
# the tests in this file.
#
................................................................................
do_test vacuum2-3.1 {
  execsql {
    INSERT INTO t1 VALUES('hello');
    INSERT INTO t2 VALUES('out there');
  }
  expr {[file size test.db]/$pageSize}
} {3}
set cksum [cksum]
do_test vacuum2-3.2 {
  cksum db2
} $cksum

# Convert the database to an autovacuumed database.
do_test vacuum2-3.3 {
  execsql {
    PRAGMA auto_vacuum=FULL;
    VACUUM;
  }
  expr {[file size test.db]/$pageSize}
} {4}
do_test vacuum2-3.4 {
  cksum db2
} $cksum
do_test vacuum2-3.5 {
  cksum
} $cksum
do_test vacuum2-3.6 {
  execsql {PRAGMA integrity_check} db2
} {ok}
do_test vacuum2-3.7 {
  execsql {PRAGMA integrity_check} db
} {ok}
................................................................................
  execsql {
    PRAGMA auto_vacuum=NONE;
    VACUUM;
  }
  expr {[file size test.db]/$pageSize}
} {3}
do_test vacuum2-3.14 {
  cksum db2
} $cksum
do_test vacuum2-3.15 {
  cksum
} $cksum
do_test vacuum2-3.16 {
  execsql {PRAGMA integrity_check} db2
} {ok}
do_test vacuum2-3.17 {
  execsql {PRAGMA integrity_check} db
} {ok}

db2 close

finish_test