**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.472 2008/07/08 19:34:07 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
................................................................................
**
** This routine is called when an operation failed with a lock.
** If this routine returns non-zero, the lock is retried.  If it
** returns 0, the operation aborts with an SQLITE_BUSY error.
*/
int sqlite3InvokeBusyHandler(BusyHandler *p){
  int rc;

  if( p==0 || p->xFunc==0 || p->nBusy<0 ) return 0;
  rc = p->xFunc(p->pArg, p->nBusy);
  if( rc==0 ){
    p->nBusy = -1;
  }else{
    p->nBusy++;
  }
  return rc; 

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.473 2008/07/09 13:28:54 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
................................................................................
**
** This routine is called when an operation failed with a lock.
** If this routine returns non-zero, the lock is retried.  If it
** returns 0, the operation aborts with an SQLITE_BUSY error.
*/
int sqlite3InvokeBusyHandler(BusyHandler *p){
  int rc;
  failsafe( p==0, 0x912aaf8d, {return 0;})
  if( p->xFunc==0 || p->nBusy<0 ) return 0;
  rc = p->xFunc(p->pArg, p->nBusy);
  if( rc==0 ){
    p->nBusy = -1;
  }else{
    p->nBusy++;
  }
  return rc; 

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.364 2008/07/07 19:52:10 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
*/
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
#define SQLITE_STATUS_SCRATCH_USED         3
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5



/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.365 2008/07/09 13:28:54 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
*/
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
#define SQLITE_STATUS_SCRATCH_USED         3
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_FAILSAFE             6


/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT

**    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 1.738 2008/07/08 23:40:20 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build
................................................................................
#ifdef SQLITE_COVERAGE_TEST
  void sqlite3Coverage(int);
# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
#else
# define testcase(X)
#endif






















/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
** a boolean expression that is usually true.  GCC is able to
** use these hints to generate better code, sometimes.
*/
................................................................................
** This structure also contains some state information.
*/
struct Sqlite3Config {
  int bMemstat;                     /* True to enable memory status */
  int bCoreMutex;                   /* True to enable core mutexing */
  int bFullMutex;                   /* True to enable full mutexing */
  int mxStrlen;                     /* Maximum string length */

  sqlite3_mem_methods m;            /* Low-level memory allocation interface */
  sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
  void *pHeap;                      /* Heap storage space */
  int nHeap;                        /* Size of pHeap[] */
  int mnReq, mxReq;                 /* Min and max heap requests sizes */
  void *pScratch;                   /* Scratch memory */
  int szScratch;                    /* Size of each scratch buffer */
................................................................................
** builds) or a function call (for debugging).  If it is a function call,
** it allows the operator to set a breakpoint at the spot where database
** corruption is first detected.
*/
#ifdef SQLITE_DEBUG
  int sqlite3Corrupt(void);
# define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
# define DEBUGONLY(X)        X
#else
# define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
# define DEBUGONLY(X)
#endif

/*
** Internal function prototypes
*/
int sqlite3StrICmp(const char *, const char *);
int sqlite3StrNICmp(const char *, const char *, int);
................................................................................
  int sqlite3SafetyOff(sqlite3*);
#else
# define sqlite3SafetyOn(A) 0
# define sqlite3SafetyOff(A) 0
#endif
int sqlite3SafetyCheckOk(sqlite3*);
int sqlite3SafetyCheckSickOrOk(sqlite3*);

void sqlite3ChangeCookie(Parse*, int);
void sqlite3MaterializeView(Parse*, Select*, Expr*, int);

#ifndef SQLITE_OMIT_TRIGGER
  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);

**    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 1.739 2008/07/09 13:28:54 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build
................................................................................
#ifdef SQLITE_COVERAGE_TEST
  void sqlite3Coverage(int);
# define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
#else
# define testcase(X)
#endif

/*
** The failsafe() macro is used to test for error conditions that
** should never occur.  This is similar to assert() except that with
** failsafe() the application attempts to recover gracefully rather
** than abort.  If a error condition is detected, a global flag is
** set to the "Id" prior to recovery in order to alert the application 
** to the error condition.
**
** The Id should be a random integer.  The idea behind the Id is that
** failsafe() faults in the field can be mapped back to specific failsafe()
** macros, even if line numbers and filenames have changed.
**
** The test condition is argument Cond.  The recovery action is
** argument Action.
*/
#ifdef SQLITE_COVERAGE_TEST
# define failsafe(Cond,Id,Action)
#else
# define failsafe(Cond,Id,Action)  if( Cond ){ sqlite3Failsafe(Id); Action; }
#endif

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
** a boolean expression that is usually true.  GCC is able to
** use these hints to generate better code, sometimes.
*/
................................................................................
** This structure also contains some state information.
*/
struct Sqlite3Config {
  int bMemstat;                     /* True to enable memory status */
  int bCoreMutex;                   /* True to enable core mutexing */
  int bFullMutex;                   /* True to enable full mutexing */
  int mxStrlen;                     /* Maximum string length */
  int iFailsafe;                    /* Id of failed failsafe() */
  sqlite3_mem_methods m;            /* Low-level memory allocation interface */
  sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
  void *pHeap;                      /* Heap storage space */
  int nHeap;                        /* Size of pHeap[] */
  int mnReq, mxReq;                 /* Min and max heap requests sizes */
  void *pScratch;                   /* Scratch memory */
  int szScratch;                    /* Size of each scratch buffer */
................................................................................
** builds) or a function call (for debugging).  If it is a function call,
** it allows the operator to set a breakpoint at the spot where database
** corruption is first detected.
*/
#ifdef SQLITE_DEBUG
  int sqlite3Corrupt(void);
# define SQLITE_CORRUPT_BKPT sqlite3Corrupt()

#else
# define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT

#endif

/*
** Internal function prototypes
*/
int sqlite3StrICmp(const char *, const char *);
int sqlite3StrNICmp(const char *, const char *, int);
................................................................................
  int sqlite3SafetyOff(sqlite3*);
#else
# define sqlite3SafetyOn(A) 0
# define sqlite3SafetyOff(A) 0
#endif
int sqlite3SafetyCheckOk(sqlite3*);
int sqlite3SafetyCheckSickOrOk(sqlite3*);
void sqlite3Failsafe(int);
void sqlite3ChangeCookie(Parse*, int);
void sqlite3MaterializeView(Parse*, Select*, Expr*, int);

#ifndef SQLITE_OMIT_TRIGGER
  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This module implements the sqlite3_status() interface and related
** functionality.
**
** $Id: status.c,v 1.1 2008/06/19 13:20:02 drh Exp $
*/
#include "sqliteInt.h"

/*
** Variables in which to record status information.
*/
static struct {
................................................................................
** Query status information.
**
** This implementation assumes that reading or writing an aligned
** 32-bit integer is an atomic operation.  If that assumption is not true,
** then this routine is not threadsafe.
*/
int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){





  if( op<0 || op>=ArraySize(sqlite3Stat.nowValue) ){
    return SQLITE_MISUSE;
  }
  *pCurrent = sqlite3Stat.nowValue[op];
  *pHighwater = sqlite3Stat.mxValue[op];
  if( resetFlag ){
    sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
  }
  return SQLITE_OK;
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This module implements the sqlite3_status() interface and related
** functionality.
**
** $Id: status.c,v 1.2 2008/07/09 13:28:54 drh Exp $
*/
#include "sqliteInt.h"

/*
** Variables in which to record status information.
*/
static struct {
................................................................................
** Query status information.
**
** This implementation assumes that reading or writing an aligned
** 32-bit integer is an atomic operation.  If that assumption is not true,
** then this routine is not threadsafe.
*/
int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
  if( op==SQLITE_STATUS_FAILSAFE ){
    *pCurrent = *pHighwater = sqlite3Config.iFailsafe;
    if( resetFlag ) sqlite3Config.iFailsafe = 0;
    return SQLITE_OK;
  }
  if( op<0 || op>=ArraySize(sqlite3Stat.nowValue) ){
    return SQLITE_MISUSE;
  }
  *pCurrent = sqlite3Stat.nowValue[op];
  *pHighwater = sqlite3Stat.mxValue[op];
  if( resetFlag ){
    sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
  }
  return SQLITE_OK;
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.33 2008/06/27 14:05:25 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
  } aOp[] = {
    { "SQLITE_STATUS_MEMORY_USED",         SQLITE_STATUS_MEMORY_USED         },
    { "SQLITE_STATUS_PAGECACHE_USED",      SQLITE_STATUS_PAGECACHE_USED      },
    { "SQLITE_STATUS_PAGECACHE_OVERFLOW",  SQLITE_STATUS_PAGECACHE_OVERFLOW  },
    { "SQLITE_STATUS_SCRATCH_USED",        SQLITE_STATUS_SCRATCH_USED        },
    { "SQLITE_STATUS_SCRATCH_OVERFLOW",    SQLITE_STATUS_SCRATCH_OVERFLOW    },
    { "SQLITE_STATUS_MALLOC_SIZE",         SQLITE_STATUS_MALLOC_SIZE         },

  };
  Tcl_Obj *pResult;
  if( objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "PARAMETER RESETFLAG");
    return TCL_ERROR;
  }
  zOpName = Tcl_GetString(objv[1]);

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.34 2008/07/09 13:28:54 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
  } aOp[] = {
    { "SQLITE_STATUS_MEMORY_USED",         SQLITE_STATUS_MEMORY_USED         },
    { "SQLITE_STATUS_PAGECACHE_USED",      SQLITE_STATUS_PAGECACHE_USED      },
    { "SQLITE_STATUS_PAGECACHE_OVERFLOW",  SQLITE_STATUS_PAGECACHE_OVERFLOW  },
    { "SQLITE_STATUS_SCRATCH_USED",        SQLITE_STATUS_SCRATCH_USED        },
    { "SQLITE_STATUS_SCRATCH_OVERFLOW",    SQLITE_STATUS_SCRATCH_OVERFLOW    },
    { "SQLITE_STATUS_MALLOC_SIZE",         SQLITE_STATUS_MALLOC_SIZE         },
    { "SQLITE_STATUS_FAILSAFE",            SQLITE_STATUS_FAILSAFE            },
  };
  Tcl_Obj *pResult;
  if( objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "PARAMETER RESETFLAG");
    return TCL_ERROR;
  }
  zOpName = Tcl_GetString(objv[1]);

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.234 2008/07/08 14:52:10 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>


/*
................................................................................
  if( db==0 ) return 0;
  magic = db->magic;
  if( magic!=SQLITE_MAGIC_SICK &&
      magic!=SQLITE_MAGIC_OPEN &&
      magic!=SQLITE_MAGIC_BUSY ) return 0;
  return 1;
}

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.235 2008/07/09 13:28:54 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>


/*
................................................................................
  if( db==0 ) return 0;
  magic = db->magic;
  if( magic!=SQLITE_MAGIC_SICK &&
      magic!=SQLITE_MAGIC_OPEN &&
      magic!=SQLITE_MAGIC_BUSY ) return 0;
  return 1;
}

/*
** Report a failsafe() macro failure
*/
void sqlite3Failsafe(int iCode){
  sqlite3Config.iFailsafe = iCode;

  /* The following assert is always false.  When assert() is enabled,
  ** the following causes a failsafe() failure to work like an assert()
  ** failure.  Normal operating mode for SQLite is for assert() to be
  ** disabled, however, so the following is normally a no-op.
  */
  assert( iCode==0 );   /* Always fails if assert() is enabled */
}

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible 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 1.314 2008/07/08 22:28:49 shane Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
  int iColumn,          /* Column number of LHS */
  Bitmask notReady,     /* RHS must not overlap with this mask */
  u16 op,               /* Mask of WO_xx values describing operator */
  Index *pIdx           /* Must be compatible with this index, if not NULL */
){
  WhereTerm *pTerm;
  int k;

  for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
    if( pTerm->leftCursor==iCur
       && (pTerm->prereqRight & notReady)==0
       && pTerm->leftColumn==iColumn
       && (pTerm->eOperator & op)!=0
    ){
      if( iCur>=0 && pIdx && pTerm->eOperator!=WO_ISNULL ){
        Expr *pX = pTerm->pExpr;
        CollSeq *pColl;
        char idxaff;
        int j;
        Parse *pParse = pWC->pParse;

        idxaff = pIdx->pTable->aCol[iColumn].affinity;
................................................................................
        */
        assert(pX->pLeft);
        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
        if( !pColl ){
          pColl = pParse->db->pDfltColl;
        }

        for(j=0; j<pIdx->nColumn && pIdx->aiColumn[j]!=iColumn; j++){}
        assert( j<pIdx->nColumn );

        if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
      }
      return pTerm;
    }
  }
  return 0;
}
................................................................................
        }
      }
    }while( !ok && (sOr.a[j++].flags & TERM_COPIED)!=0 && j<2 );
    if( ok ){
      ExprList *pList = 0;
      Expr *pNew, *pDup;
      Expr *pLeft = 0;
      for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0 && ok; i--, pOrTerm++){
        if( (pOrTerm->flags & TERM_OR_OK)==0 ) continue;
        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight);
        pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup, 0);
        pLeft = pOrTerm->pExpr->pLeft;
      }
      assert( pLeft!=0 );
      pDup = sqlite3ExprDup(db, pLeft);
................................................................................
      if( pTerm==0 ) break;
      flags |= WHERE_COLUMN_EQ;
      if( pTerm->eOperator & WO_IN ){
        Expr *pExpr = pTerm->pExpr;
        flags |= WHERE_COLUMN_IN;
        if( pExpr->pSelect!=0 ){
          inMultiplier *= 25;

        }else if( pExpr->pList!=0 ){
          inMultiplier *= pExpr->pList->nExpr + 1;
        }
      }
    }
    cost = pProbe->aiRowEst[i] * inMultiplier * estLog(inMultiplier);
    nEq = i;
    if( pProbe->onError!=OE_None && (flags & WHERE_COLUMN_IN)==0
................................................................................
** loop.  We would get the correct results if nothing were ever disabled,
** but joins might run a little slower.  The trick is to disable as much
** as we can without disabling too much.  If we disabled in (1), we'd get
** the wrong answer.  See ticket #813.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
  if( pTerm
      && (pTerm->flags & TERM_CODED)==0
      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
  ){

    pTerm->flags |= TERM_CODED;
    if( pTerm->iParent>=0 ){
      WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
      if( (--pOther->nChild)==0 ){
        disableTerm(pLevel, pOther);
      }
    }
................................................................................
  /* Evaluate the equality constraints
  */
  assert( pIdx->nColumn>=nEq );
  for(j=0; j<nEq; j++){
    int r1;
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    if( pTerm==0 ) break;
    assert( (pTerm->flags & TERM_CODED)==0 );
    r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
    if( r1!=regBase+j ){
      sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
    }
    testcase( pTerm->eOperator & WO_ISNULL );
    testcase( pTerm->eOperator & WO_IN );

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible 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 1.315 2008/07/09 13:28:54 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
  int iColumn,          /* Column number of LHS */
  Bitmask notReady,     /* RHS must not overlap with this mask */
  u16 op,               /* Mask of WO_xx values describing operator */
  Index *pIdx           /* Must be compatible with this index, if not NULL */
){
  WhereTerm *pTerm;
  int k;
  assert( iCur>=0 );
  for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
    if( pTerm->leftCursor==iCur
       && (pTerm->prereqRight & notReady)==0
       && pTerm->leftColumn==iColumn
       && (pTerm->eOperator & op)!=0
    ){
      if( pIdx && pTerm->eOperator!=WO_ISNULL ){
        Expr *pX = pTerm->pExpr;
        CollSeq *pColl;
        char idxaff;
        int j;
        Parse *pParse = pWC->pParse;

        idxaff = pIdx->pTable->aCol[iColumn].affinity;
................................................................................
        */
        assert(pX->pLeft);
        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
        if( !pColl ){
          pColl = pParse->db->pDfltColl;
        }

        for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
          failsafe( j>=pIdx->nColumn, 0x0128fc98, {return 0;});
        }
        if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
      }
      return pTerm;
    }
  }
  return 0;
}
................................................................................
        }
      }
    }while( !ok && (sOr.a[j++].flags & TERM_COPIED)!=0 && j<2 );
    if( ok ){
      ExprList *pList = 0;
      Expr *pNew, *pDup;
      Expr *pLeft = 0;
      for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0; i--, pOrTerm++){
        if( (pOrTerm->flags & TERM_OR_OK)==0 ) continue;
        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight);
        pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup, 0);
        pLeft = pOrTerm->pExpr->pLeft;
      }
      assert( pLeft!=0 );
      pDup = sqlite3ExprDup(db, pLeft);
................................................................................
      if( pTerm==0 ) break;
      flags |= WHERE_COLUMN_EQ;
      if( pTerm->eOperator & WO_IN ){
        Expr *pExpr = pTerm->pExpr;
        flags |= WHERE_COLUMN_IN;
        if( pExpr->pSelect!=0 ){
          inMultiplier *= 25;
        }else{
          failsafe( pExpr->pList==0, 0x16b91d0f, continue);
          inMultiplier *= pExpr->pList->nExpr + 1;
        }
      }
    }
    cost = pProbe->aiRowEst[i] * inMultiplier * estLog(inMultiplier);
    nEq = i;
    if( pProbe->onError!=OE_None && (flags & WHERE_COLUMN_IN)==0
................................................................................
** loop.  We would get the correct results if nothing were ever disabled,
** but joins might run a little slower.  The trick is to disable as much
** as we can without disabling too much.  If we disabled in (1), we'd get
** the wrong answer.  See ticket #813.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
  if( pTerm

      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
  ){
    failsafe( (pTerm->flags & TERM_CODED)!=0, 0x641154a4, /* no-op */ );
    pTerm->flags |= TERM_CODED;
    if( pTerm->iParent>=0 ){
      WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
      if( (--pOther->nChild)==0 ){
        disableTerm(pLevel, pOther);
      }
    }
................................................................................
  /* Evaluate the equality constraints
  */
  assert( pIdx->nColumn>=nEq );
  for(j=0; j<nEq; j++){
    int r1;
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    failsafe( pTerm==0, 0x7592494c, break );
    assert( (pTerm->flags & TERM_CODED)==0 );
    r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
    if( r1!=regBase+j ){
      sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
    }
    testcase( pTerm->eOperator & WO_ISNULL );
    testcase( pTerm->eOperator & WO_IN );