# Compiler options needed for programs that use the TCL library.
#
TCC += @TCL_INCLUDE_SPEC@

# The library that programs using TCL must link against.
#
LIBTCL = @TCL_LIB_SPEC@ @TCL_LIBS@

# Compiler options needed for programs that use the readline() library.
#
READLINE_FLAGS = -DHAVE_READLINE=@TARGET_HAVE_READLINE@ @TARGET_READLINE_INC@

# The library that programs using readline() must link against.
#
................................................................................

clean:	
	rm -f *.lo *.la *.o sqlite3$(TEXE) libsqlite3.la
	rm -f sqlite3.h opcodes.*
	rm -rf .libs .deps
	rm -f lemon$(BEXE) lempar.c parse.* sqlite*.tar.gz
	rm -f mkkeywordhash$(BEXE) keywordhash.h
	rm -f $(PUBLISH)
	rm -f *.da *.bb *.bbg gmon.out
	rm -rf quota2a quota2b quota2c
	rm -rf tsrc .target_source
	rm -f tclsqlite3$(TEXE)
	rm -f testfixture$(TEXE) test.db
	rm -f sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
	rm -f sqlite3.c

# Compiler options needed for programs that use the TCL library.
#
TCC += @TCL_INCLUDE_SPEC@

# The library that programs using TCL must link against.
#
LIBTCL = @TCL_LIB_SPEC@

# Compiler options needed for programs that use the readline() library.
#
READLINE_FLAGS = -DHAVE_READLINE=@TARGET_HAVE_READLINE@ @TARGET_READLINE_INC@

# The library that programs using readline() must link against.
#
................................................................................

clean:	
	rm -f *.lo *.la *.o sqlite3$(TEXE) libsqlite3.la
	rm -f sqlite3.h opcodes.*
	rm -rf .libs .deps
	rm -f lemon$(BEXE) lempar.c parse.* sqlite*.tar.gz
	rm -f mkkeywordhash$(BEXE) keywordhash.h

	rm -f *.da *.bb *.bbg gmon.out
	rm -rf quota2a quota2b quota2c
	rm -rf tsrc .target_source
	rm -f tclsqlite3$(TEXE)
	rm -f testfixture$(TEXE) test.db
	rm -f sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
	rm -f sqlite3.c

	$(TCLSH_CMD) $(TOP)\tool\vdbe-compress.tcl < tsrc\vdbe.c > vdbe.new
	move vdbe.new tsrc\vdbe.c
	echo > .target_source

sqlite3.c:	.target_source $(TOP)\tool\mksqlite3c.tcl
	$(TCLSH_CMD) $(TOP)\tool\mksqlite3c.tcl

sqlite3-all.c:	sqlite3.c $(TOP)/tool/split-sqlite3c.tcl
	$(TCLSH_CMD) $(TOP)/tool/split-sqlite3c.tcl

# Rule to build the amalgamation
#
sqlite3.lo:	sqlite3.c
	$(LTCOMPILE) -c sqlite3.c

# Rules to build the LEMON compiler generator

	$(TCLSH_CMD) $(TOP)\tool\vdbe-compress.tcl < tsrc\vdbe.c > vdbe.new
	move vdbe.new tsrc\vdbe.c
	echo > .target_source

sqlite3.c:	.target_source $(TOP)\tool\mksqlite3c.tcl
	$(TCLSH_CMD) $(TOP)\tool\mksqlite3c.tcl

sqlite3-all.c:	sqlite3.c $(TOP)\tool\split-sqlite3c.tcl
	$(TCLSH_CMD) $(TOP)\tool\split-sqlite3c.tcl

# Rule to build the amalgamation
#
sqlite3.lo:	sqlite3.c
	$(LTCOMPILE) -c sqlite3.c

# Rules to build the LEMON compiler generator

SQLITE_OS_UNIX
SQLITE_OS_WIN
SQLITE_OS_OS2
TARGET_EXEEXT
TCL_VERSION
TCL_BIN_DIR
TCL_SRC_DIR
TCL_LIBS
TCL_INCLUDE_SPEC
TCL_LIB_FILE
TCL_LIB_FLAG
TCL_LIB_SPEC
TCL_STUB_LIB_FILE
TCL_STUB_LIB_FLAG
TCL_STUB_LIB_SPEC

SQLITE_OS_UNIX
SQLITE_OS_WIN
SQLITE_OS_OS2
TARGET_EXEEXT
TCL_VERSION
TCL_BIN_DIR
TCL_SRC_DIR

TCL_INCLUDE_SPEC
TCL_LIB_FILE
TCL_LIB_FLAG
TCL_LIB_SPEC
TCL_STUB_LIB_FILE
TCL_STUB_LIB_FLAG
TCL_STUB_LIB_SPEC

    eval "TCL_STUB_LIB_FILE=\"${TCL_STUB_LIB_FILE}\""
    eval "TCL_STUB_LIB_FLAG=\"${TCL_STUB_LIB_FLAG}\""
    eval "TCL_STUB_LIB_SPEC=\"${TCL_STUB_LIB_SPEC}\""
    
    AC_SUBST(TCL_VERSION)
    AC_SUBST(TCL_BIN_DIR)
    AC_SUBST(TCL_SRC_DIR)
    AC_SUBST(TCL_LIBS)
    AC_SUBST(TCL_INCLUDE_SPEC)
    
    AC_SUBST(TCL_LIB_FILE)
    AC_SUBST(TCL_LIB_FLAG)
    AC_SUBST(TCL_LIB_SPEC)
    
    AC_SUBST(TCL_STUB_LIB_FILE)

    eval "TCL_STUB_LIB_FILE=\"${TCL_STUB_LIB_FILE}\""
    eval "TCL_STUB_LIB_FLAG=\"${TCL_STUB_LIB_FLAG}\""
    eval "TCL_STUB_LIB_SPEC=\"${TCL_STUB_LIB_SPEC}\""
    
    AC_SUBST(TCL_VERSION)
    AC_SUBST(TCL_BIN_DIR)
    AC_SUBST(TCL_SRC_DIR)

    AC_SUBST(TCL_INCLUDE_SPEC)
    
    AC_SUBST(TCL_LIB_FILE)
    AC_SUBST(TCL_LIB_FLAG)
    AC_SUBST(TCL_LIB_SPEC)
    
    AC_SUBST(TCL_STUB_LIB_FILE)

Normally, when SQLite writes to a database file, it waits until the write
operation is finished before returning control to the calling application.
Since writing to the file-system is usually very slow compared with CPU
bound operations, this can be a performance bottleneck. This directory
contains an extension that causes SQLite to perform all write requests
using a separate thread running in the background. Although this does not
................................................................................
    static void async_mutex_leave(int eMutex);
    static void async_cond_wait(int eCond, int eMutex);
    static void async_cond_signal(int eCond);
    static void async_sched_yield(void);

  The functionality required of each of the above functions is described
  in comments in sqlite3async.c.

NOTE (2012-11-29):

The functionality implemented by this extension has been superseded
by WAL-mode.  This module is no longer supported or maintained.  The
code is retained for historical reference only.

------------------------------------------------------------------------------

Normally, when SQLite writes to a database file, it waits until the write
operation is finished before returning control to the calling application.
Since writing to the file-system is usually very slow compared with CPU
bound operations, this can be a performance bottleneck. This directory
contains an extension that causes SQLite to perform all write requests
using a separate thread running in the background. Although this does not
................................................................................
    static void async_mutex_leave(int eMutex);
    static void async_cond_wait(int eCond, int eMutex);
    static void async_cond_signal(int eCond);
    static void async_sched_yield(void);

  The functionality required of each of the above functions is described
  in comments in sqlite3async.c.

        }
        break;
      }

      case ASYNC_DELETE:
        ASYNC_TRACE(("DELETE %s\n", p->zBuf));
        rc = pVfs->xDelete(pVfs, p->zBuf, (int)p->iOffset);

        break;

      case ASYNC_OPENEXCLUSIVE: {
        int flags = (int)p->iOffset;
        AsyncFileData *pData = p->pFileData;
        ASYNC_TRACE(("OPEN %s flags=%d\n", p->zBuf, (int)p->iOffset));
        assert(pData->pBaseRead->pMethods==0 && pData->pBaseWrite->pMethods==0);

        }
        break;
      }

      case ASYNC_DELETE:
        ASYNC_TRACE(("DELETE %s\n", p->zBuf));
        rc = pVfs->xDelete(pVfs, p->zBuf, (int)p->iOffset);
        if( rc==SQLITE_IOERR_DELETE_NOENT ) rc = SQLITE_OK;
        break;

      case ASYNC_OPENEXCLUSIVE: {
        int flags = (int)p->iOffset;
        AsyncFileData *pData = p->pFileData;
        ASYNC_TRACE(("OPEN %s flags=%d\n", p->zBuf, (int)p->iOffset));
        assert(pData->pBaseRead->pMethods==0 && pData->pBaseWrite->pMethods==0);

/*
** This function unregisters the asynchronous IO VFS using 
** sqlite3_vfs_unregister().
**
** On win32 platforms, this function also releases the small number of 
** critical section and event objects created by sqlite3async_initialize().
*/ 
void sqlite3async_shutdown();

/*
** This function may only be called when the asynchronous IO VFS is 
** installed (after a call to sqlite3async_initialize()). It processes
** zero or more queued write operations before returning. It is expected
** (but not required) that this function will be called by a different 
** thread than those threads that use SQLite. The "background thread"
................................................................................
** verb to sqlite3async_control() (see below for details). By default
** this function never returns - it processes all pending operations and 
** then blocks waiting for new ones.
**
** If multiple simultaneous calls are made to sqlite3async_run() from two
** or more threads, then the calls are serialized internally.
*/
void sqlite3async_run();

/*
** This function may only be called when the asynchronous IO VFS is 
** installed (after a call to sqlite3async_initialize()). It is used 
** to query or configure various parameters that affect the operation 
** of the asynchronous IO VFS. At present there are three parameters 
** supported:

/*
** This function unregisters the asynchronous IO VFS using 
** sqlite3_vfs_unregister().
**
** On win32 platforms, this function also releases the small number of 
** critical section and event objects created by sqlite3async_initialize().
*/ 
void sqlite3async_shutdown(void);

/*
** This function may only be called when the asynchronous IO VFS is 
** installed (after a call to sqlite3async_initialize()). It processes
** zero or more queued write operations before returning. It is expected
** (but not required) that this function will be called by a different 
** thread than those threads that use SQLite. The "background thread"
................................................................................
** verb to sqlite3async_control() (see below for details). By default
** this function never returns - it processes all pending operations and 
** then blocks waiting for new ones.
**
** If multiple simultaneous calls are made to sqlite3async_run() from two
** or more threads, then the calls are serialized internally.
*/
void sqlite3async_run(void);

/*
** This function may only be called when the asynchronous IO VFS is 
** installed (after a call to sqlite3async_initialize()). It is used 
** to query or configure various parameters that affect the operation 
** of the asynchronous IO VFS. At present there are three parameters 
** supported:

  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  assert( p->pSegments==0 );
  assert( 
      nArg==1                     /* DELETE operations */
   || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */

  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  u32 *aSzIns = 0;                /* Sizes of inserted documents */
  u32 *aSzDel = 0;                /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;

  assert( p->pSegments==0 );
  assert( 
      nArg==1                     /* DELETE operations */
   || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */

  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pItem->zDatabase && sqlite3StrICmp(pItem->zDatabase, zDb) ){
      sqlite3ErrorMsg(pFix->pParse,
         "%s %T cannot reference objects in database %s",
         pFix->zType, pFix->pName, pItem->zDatabase);
      return 1;
    }
    sqlite3_free(pItem->zDatabase);
    pItem->zDatabase = 0;
    pItem->pSchema = pFix->pSchema;
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
    if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
    if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
#endif
  }

  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pItem->zDatabase && sqlite3StrICmp(pItem->zDatabase, zDb) ){
      sqlite3ErrorMsg(pFix->pParse,
         "%s %T cannot reference objects in database %s",
         pFix->zType, pFix->pName, pItem->zDatabase);
      return 1;
    }
    sqlite3DbFree(pFix->pParse->db, pItem->zDatabase);
    pItem->zDatabase = 0;
    pItem->pSchema = pFix->pSchema;
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
    if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
    if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
#endif
  }

** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
void sqlite3FinishCoding(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;


  db = pParse->db;
  if( db->mallocFailed ) return;
  if( pParse->nested ) return;
  if( pParse->nErr ) return;

  /* Begin by generating some termination code at the end of the
  ** vdbe program
................................................................................

  /* Figure out how many bytes of space are required to store explicitly
  ** specified collation sequence names.
  */
  for(i=0; i<pList->nExpr; i++){
    Expr *pExpr = pList->a[i].pExpr;
    if( pExpr ){
      CollSeq *pColl = pExpr->pColl;
      /* Either pColl!=0 or there was an OOM failure.  But if an OOM
      ** failure we have quit before reaching this point. */
      if( ALWAYS(pColl) ){
        nExtra += (1 + sqlite3Strlen30(pColl->zName));
      }
    }
  }

  /* 
  ** Allocate the index structure. 
................................................................................
  ** same column more than once cannot be an error because that would 
  ** break backwards compatibility - it needs to be a warning.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    const char *zColName = pListItem->zName;
    Column *pTabCol;
    int requestedSortOrder;

    char *zColl;                   /* Collation sequence name */

    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
      if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
        pTab->zName, zColName);
      pParse->checkSchema = 1;
      goto exit_create_index;
    }
    pIndex->aiColumn[i] = j;
    /* Justification of the ALWAYS(pListItem->pExpr->pColl):  Because of
    ** the way the "idxlist" non-terminal is constructed by the parser,
    ** if pListItem->pExpr is not null then either pListItem->pExpr->pColl
    ** must exist or else there must have been an OOM error.  But if there
    ** was an OOM error, we would never reach this point. */
    if( pListItem->pExpr && ALWAYS(pListItem->pExpr->pColl) ){


      int nColl;
      zColl = pListItem->pExpr->pColl->zName;
      nColl = sqlite3Strlen30(zColl) + 1;
      assert( nExtra>=nColl );
      memcpy(zExtra, zColl, nColl);
      zColl = zExtra;
      zExtra += nColl;
      nExtra -= nColl;
    }else{
................................................................................
** If iDb<0 then code the OP_Goto only - don't set flag to verify the
** schema on any databases.  This can be used to position the OP_Goto
** early in the code, before we know if any database tables will be used.
*/
void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);










  if( pToplevel->cookieGoto==0 ){
    Vdbe *v = sqlite3GetVdbe(pToplevel);
    if( v==0 ) return;  /* This only happens if there was a prior error */
    pToplevel->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    sqlite3 *db = pToplevel->db;

** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
void sqlite3FinishCoding(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  assert( pParse->pToplevel==0 );
  db = pParse->db;
  if( db->mallocFailed ) return;
  if( pParse->nested ) return;
  if( pParse->nErr ) return;

  /* Begin by generating some termination code at the end of the
  ** vdbe program
................................................................................

  /* Figure out how many bytes of space are required to store explicitly
  ** specified collation sequence names.
  */
  for(i=0; i<pList->nExpr; i++){
    Expr *pExpr = pList->a[i].pExpr;
    if( pExpr ){
      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr);
      if( pColl ){


        nExtra += (1 + sqlite3Strlen30(pColl->zName));
      }
    }
  }

  /* 
  ** Allocate the index structure. 
................................................................................
  ** same column more than once cannot be an error because that would 
  ** break backwards compatibility - it needs to be a warning.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    const char *zColName = pListItem->zName;
    Column *pTabCol;
    int requestedSortOrder;
    CollSeq *pColl;                /* Collating sequence */
    char *zColl;                   /* Collation sequence name */

    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
      if( sqlite3StrICmp(zColName, pTabCol->zName)==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqlite3ErrorMsg(pParse, "table %s has no column named %s",
        pTab->zName, zColName);
      pParse->checkSchema = 1;
      goto exit_create_index;
    }
    pIndex->aiColumn[i] = j;





    if( pListItem->pExpr
     && (pColl = sqlite3ExprCollSeq(pParse, pListItem->pExpr))!=0
    ){
      int nColl;
      zColl = pColl->zName;
      nColl = sqlite3Strlen30(zColl) + 1;
      assert( nExtra>=nColl );
      memcpy(zExtra, zColl, nColl);
      zColl = zExtra;
      zExtra += nColl;
      nExtra -= nColl;
    }else{
................................................................................
** If iDb<0 then code the OP_Goto only - don't set flag to verify the
** schema on any databases.  This can be used to position the OP_Goto
** early in the code, before we know if any database tables will be used.
*/
void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);

#ifndef SQLITE_OMIT_TRIGGER
  if( pToplevel!=pParse ){
    /* This branch is taken if a trigger is currently being coded. In this
    ** case, set cookieGoto to a non-zero value to show that this function
    ** has been called. This is used by the sqlite3ExprCodeConstants()
    ** function. */
    pParse->cookieGoto = -1;
  }
#endif
  if( pToplevel->cookieGoto==0 ){
    Vdbe *v = sqlite3GetVdbe(pToplevel);
    if( v==0 ) return;  /* This only happens if there was a prior error */
    pToplevel->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    sqlite3 *db = pToplevel->db;

**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){


  int op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
  }
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
    assert( !ExprHasProperty(pExpr, EP_IntValue) );
................................................................................
    assert( pExpr->pTab && j<pExpr->pTab->nCol );
    return pExpr->pTab->aCol[j].affinity;
  }
  return pExpr->affinity;
}

/*
** Set the explicit collating sequence for an expression to the
** collating sequence supplied in the second argument.




*/
Expr *sqlite3ExprSetColl(Expr *pExpr, CollSeq *pColl){
  if( pExpr && pColl ){
    pExpr->pColl = pColl;





    pExpr->flags |= EP_ExpCollate;

  }

  return pExpr;
}








/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken.   Return a pointer to the revised expression.
** The collating sequence is marked as "explicit" using the EP_ExpCollate
** flag.  An explicit collating sequence will override implicit
** collating sequences.


*/
Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr *pExpr, Token *pCollName){
  char *zColl = 0;            /* Dequoted name of collation sequence */
  CollSeq *pColl;
  sqlite3 *db = pParse->db;
  zColl = sqlite3NameFromToken(db, pCollName);
  pColl = sqlite3LocateCollSeq(pParse, zColl);
  sqlite3ExprSetColl(pExpr, pColl);
  sqlite3DbFree(db, zColl);




  return pExpr;
}

/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.






*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){

  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op;

    pColl = p->pColl;










    if( pColl ) break;
    op = p->op;

    if( p->pTab!=0 && (

        op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER
    )){
      /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
      ** a TK_COLUMN but was previously evaluated and cached in a register */
      const char *zColl;
      int j = p->iColumn;
      if( j>=0 ){
        sqlite3 *db = pParse->db;
        zColl = p->pTab->aCol[j].zColl;
        pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
        pExpr->pColl = pColl;
      }
      break;
    }
    if( op!=TK_CAST && op!=TK_UPLUS ){






      break;
    }
    p = p->pLeft;
  }
  if( sqlite3CheckCollSeq(pParse, pColl) ){ 
    pColl = 0;
  }
  return pColl;
}

................................................................................
CollSeq *sqlite3BinaryCompareCollSeq(
  Parse *pParse, 
  Expr *pLeft, 
  Expr *pRight
){
  CollSeq *pColl;
  assert( pLeft );
  if( pLeft->flags & EP_ExpCollate ){
    assert( pLeft->pColl );
    pColl = pLeft->pColl;
  }else if( pRight && pRight->flags & EP_ExpCollate ){
    assert( pRight->pColl );
    pColl = pRight->pColl;

  }else{
    pColl = sqlite3ExprCollSeq(pParse, pLeft);
    if( !pColl ){
      pColl = sqlite3ExprCollSeq(pParse, pRight);
    }
  }
  return pColl;
................................................................................
  if( pRoot==0 ){
    assert( db->mallocFailed );
    sqlite3ExprDelete(db, pLeft);
    sqlite3ExprDelete(db, pRight);
  }else{
    if( pRight ){
      pRoot->pRight = pRight;
      if( pRight->flags & EP_ExpCollate ){
        pRoot->flags |= EP_ExpCollate;
        pRoot->pColl = pRight->pColl;
      }
    }
    if( pLeft ){
      pRoot->pLeft = pLeft;
      if( pLeft->flags & EP_ExpCollate ){
        pRoot->flags |= EP_ExpCollate;
        pRoot->pColl = pLeft->pColl;
      }
    }
    exprSetHeight(pRoot);
  }
}

/*
** Allocate a Expr node which joins as many as two subtrees.
................................................................................
  if( 0==(flags&EXPRDUP_REDUCE) ){
    nSize = EXPR_FULLSIZE;
  }else{
    assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
    assert( !ExprHasProperty(p, EP_FromJoin) ); 
    assert( (p->flags2 & EP2_MallocedToken)==0 );
    assert( (p->flags2 & EP2_Irreducible)==0 );
    if( p->pLeft || p->pRight || p->pColl || p->x.pList ){
      nSize = EXPR_REDUCEDSIZE | EP_Reduced;
    }else{
      nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
    }
  }
  return nSize;
}
................................................................................
      testcase( regFree2==0 );
      codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
      sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
      sqlite3ReleaseTempReg(pParse, r3);
      sqlite3ReleaseTempReg(pParse, r4);
      break;
    }

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

    case TK_TRIGGER: {
      /* If the opcode is TK_TRIGGER, then the expression is a reference
................................................................................

    case TK_UMINUS:  zUniOp = "UMINUS"; break;
    case TK_UPLUS:   zUniOp = "UPLUS";  break;
    case TK_BITNOT:  zUniOp = "BITNOT"; break;
    case TK_NOT:     zUniOp = "NOT";    break;
    case TK_ISNULL:  zUniOp = "ISNULL"; break;
    case TK_NOTNULL: zUniOp = "NOTNULL"; break;







    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pFarg;       /* List of function arguments */
      if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
        pFarg = 0;
................................................................................
static int evalConstExpr(Walker *pWalker, Expr *pExpr){
  Parse *pParse = pWalker->pParse;
  switch( pExpr->op ){
    case TK_IN:
    case TK_REGISTER: {
      return WRC_Prune;
    }



    case TK_FUNCTION:
    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC: {
      /* The arguments to a function have a fixed destination.
      ** Mark them this way to avoid generated unneeded OP_SCopy
      ** instructions. 
      */
................................................................................
        }
      }
      break;
    }
  }
  if( isAppropriateForFactoring(pExpr) ){
    int r1 = ++pParse->nMem;
    int r2;
    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);

    if( NEVER(r1!=r2) ) sqlite3ReleaseTempReg(pParse, r1);


    pExpr->op2 = pExpr->op;
    pExpr->op = TK_REGISTER;
    pExpr->iTable = r2;
    return WRC_Prune;
  }
  return WRC_Continue;
}
................................................................................
  }
  assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) );
  assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) );
  if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
    return 2;
  }
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
  if( pA->op!=pB->op ) return 2;








  if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
  if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
  if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
  if( ExprHasProperty(pA, EP_IntValue) ){
    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
      return 2;
    }
  }else if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken){
    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
    }
  }
  if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
  if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
  return 0;
}

/*
** Compare two ExprList objects.  Return 0 if they are identical and 
** non-zero if they differ in any way.
**

**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
  int op;
  pExpr = sqlite3ExprSkipCollate(pExpr);
  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
  }
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
    assert( !ExprHasProperty(pExpr, EP_IntValue) );
................................................................................
    assert( pExpr->pTab && j<pExpr->pTab->nCol );
    return pExpr->pTab->aCol[j].affinity;
  }
  return pExpr->affinity;
}

/*
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken.   Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/



Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr *pExpr, Token *pCollName){
  if( pCollName->n>0 ){
    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, 1);
    if( pNew ){
      pNew->pLeft = pExpr;
      pNew->flags |= EP_Collate;
      pExpr = pNew;
    }
  }
  return pExpr;
}
Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
  Token s;
  assert( zC!=0 );
  s.z = zC;
  s.n = sqlite3Strlen30(s.z);
  return sqlite3ExprAddCollateToken(pParse, pExpr, &s);
}

/*





** Skip over any TK_COLLATE and/or TK_AS operators at the root of
** an expression.
*/








Expr *sqlite3ExprSkipCollate(Expr *pExpr){
  while( pExpr && (pExpr->op==TK_COLLATE || pExpr->op==TK_AS) ){
    pExpr = pExpr->pLeft;
  }
  return pExpr;
}

/*
** Return the collation sequence for the expression pExpr. If

** there is no defined collating sequence, return NULL.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence.  Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op = p->op;
    if( op==TK_CAST || op==TK_UPLUS ){
      p = p->pLeft;
      continue;
    }
    assert( op!=TK_REGISTER || p->op2!=TK_COLLATE );
    if( op==TK_COLLATE ){
      if( db->init.busy ){
        /* Do not report errors when parsing while the schema */
        pColl = sqlite3FindCollSeq(db, ENC(db), p->u.zToken, 0);
      }else{
        pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
      }
      break;

    }
    if( p->pTab!=0
     && (op==TK_AGG_COLUMN || op==TK_COLUMN
          || op==TK_REGISTER || op==TK_TRIGGER)
    ){
      /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
      ** a TK_COLUMN but was previously evaluated and cached in a register */

      int j = p->iColumn;
      if( j>=0 ){

        const char *zColl = p->pTab->aCol[j].zColl;
        pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);

      }
      break;
    }
    if( p->flags & EP_Collate ){
      if( ALWAYS(p->pLeft) && (p->pLeft->flags & EP_Collate)!=0 ){
        p = p->pLeft;
      }else{
        p = p->pRight;
      }
    }else{
      break;
    }

  }
  if( sqlite3CheckCollSeq(pParse, pColl) ){ 
    pColl = 0;
  }
  return pColl;
}

................................................................................
CollSeq *sqlite3BinaryCompareCollSeq(
  Parse *pParse, 
  Expr *pLeft, 
  Expr *pRight
){
  CollSeq *pColl;
  assert( pLeft );
  if( pLeft->flags & EP_Collate ){
    pColl = sqlite3ExprCollSeq(pParse, pLeft);

  }else if( pRight && (pRight->flags & EP_Collate)!=0 ){


    pColl = sqlite3ExprCollSeq(pParse, pRight);
  }else{
    pColl = sqlite3ExprCollSeq(pParse, pLeft);
    if( !pColl ){
      pColl = sqlite3ExprCollSeq(pParse, pRight);
    }
  }
  return pColl;
................................................................................
  if( pRoot==0 ){
    assert( db->mallocFailed );
    sqlite3ExprDelete(db, pLeft);
    sqlite3ExprDelete(db, pRight);
  }else{
    if( pRight ){
      pRoot->pRight = pRight;

      pRoot->flags |= EP_Collate & pRight->flags;


    }
    if( pLeft ){
      pRoot->pLeft = pLeft;

      pRoot->flags |= EP_Collate & pLeft->flags;


    }
    exprSetHeight(pRoot);
  }
}

/*
** Allocate a Expr node which joins as many as two subtrees.
................................................................................
  if( 0==(flags&EXPRDUP_REDUCE) ){
    nSize = EXPR_FULLSIZE;
  }else{
    assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
    assert( !ExprHasProperty(p, EP_FromJoin) ); 
    assert( (p->flags2 & EP2_MallocedToken)==0 );
    assert( (p->flags2 & EP2_Irreducible)==0 );
    if( p->pLeft || p->pRight || p->x.pList ){
      nSize = EXPR_REDUCEDSIZE | EP_Reduced;
    }else{
      nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
    }
  }
  return nSize;
}
................................................................................
      testcase( regFree2==0 );
      codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
      sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
      sqlite3ReleaseTempReg(pParse, r3);
      sqlite3ReleaseTempReg(pParse, r4);
      break;
    }
    case TK_COLLATE: 
    case TK_UPLUS: {
      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
      break;
    }

    case TK_TRIGGER: {
      /* If the opcode is TK_TRIGGER, then the expression is a reference
................................................................................

    case TK_UMINUS:  zUniOp = "UMINUS"; break;
    case TK_UPLUS:   zUniOp = "UPLUS";  break;
    case TK_BITNOT:  zUniOp = "BITNOT"; break;
    case TK_NOT:     zUniOp = "NOT";    break;
    case TK_ISNULL:  zUniOp = "ISNULL"; break;
    case TK_NOTNULL: zUniOp = "NOTNULL"; break;

    case TK_COLLATE: {
      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      sqlite3ExplainPrintf(pOut,".COLLATE(%s)",pExpr->u.zToken);
      break;
    }

    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pFarg;       /* List of function arguments */
      if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
        pFarg = 0;
................................................................................
static int evalConstExpr(Walker *pWalker, Expr *pExpr){
  Parse *pParse = pWalker->pParse;
  switch( pExpr->op ){
    case TK_IN:
    case TK_REGISTER: {
      return WRC_Prune;
    }
    case TK_COLLATE: {
      return WRC_Continue;
    }
    case TK_FUNCTION:
    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC: {
      /* The arguments to a function have a fixed destination.
      ** Mark them this way to avoid generated unneeded OP_SCopy
      ** instructions. 
      */
................................................................................
        }
      }
      break;
    }
  }
  if( isAppropriateForFactoring(pExpr) ){
    int r1 = ++pParse->nMem;

    int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
    /* If r2!=r1, it means that register r1 is never used.  That is harmless
    ** but suboptimal, so we want to know about the situation to fix it.
    ** Hence the following assert: */
    assert( r2==r1 );
    pExpr->op2 = pExpr->op;
    pExpr->op = TK_REGISTER;
    pExpr->iTable = r2;
    return WRC_Prune;
  }
  return WRC_Continue;
}
................................................................................
  }
  assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) );
  assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) );
  if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
    return 2;
  }
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
  if( pA->op!=pB->op ){
    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB)<2 ){
      return 1;
    }
    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft)<2 ){
      return 1;
    }
    return 2;
  }
  if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
  if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
  if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
  if( ExprHasProperty(pA, EP_IntValue) ){
    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
      return 2;
    }
  }else if( pA->op!=TK_COLUMN && ALWAYS(pA->op!=TK_AGG_COLUMN) && pA->u.zToken){
    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return pA->op==TK_COLLATE ? 1 : 2;
    }
  }


  return 0;
}

/*
** Compare two ExprList objects.  Return 0 if they are identical and 
** non-zero if they differ in any way.
**

    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
    if( pLeft ){
      /* Set the collation sequence and affinity of the LHS of each TK_EQ
      ** expression to the parent key column defaults.  */
      if( pIdx ){
        Column *pCol;

        iCol = pIdx->aiColumn[i];
        pCol = &pTab->aCol[iCol];
        if( pTab->iPKey==iCol ) iCol = -1;
        pLeft->iTable = regData+iCol+1;
        pLeft->affinity = pCol->affinity;
        pLeft->pColl = sqlite3LocateCollSeq(pParse, pCol->zColl);


      }else{
        pLeft->iTable = regData;
        pLeft->affinity = SQLITE_AFF_INTEGER;
      }
    }
    iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
    assert( iCol>=0 );

    pLeft = sqlite3Expr(db, TK_REGISTER, 0);
    if( pLeft ){
      /* Set the collation sequence and affinity of the LHS of each TK_EQ
      ** expression to the parent key column defaults.  */
      if( pIdx ){
        Column *pCol;
        const char *zColl;
        iCol = pIdx->aiColumn[i];
        pCol = &pTab->aCol[iCol];
        if( pTab->iPKey==iCol ) iCol = -1;
        pLeft->iTable = regData+iCol+1;
        pLeft->affinity = pCol->affinity;
        zColl = pCol->zColl;
        if( zColl==0 ) zColl = db->pDfltColl->zName;
        pLeft = sqlite3ExprAddCollateString(pParse, pLeft, zColl);
      }else{
        pLeft->iTable = regData;
        pLeft->affinity = SQLITE_AFF_INTEGER;
      }
    }
    iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
    assert( iCol>=0 );

  const unsigned char *zNeedle;
  int nHaystack;
  int nNeedle;
  int typeHaystack, typeNeedle;
  int N = 1;
  int isText;


  typeHaystack = sqlite3_value_type(argv[0]);
  typeNeedle = sqlite3_value_type(argv[1]);
  if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
  nHaystack = sqlite3_value_bytes(argv[0]);
  nNeedle = sqlite3_value_bytes(argv[1]);
  if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
    zHaystack = sqlite3_value_blob(argv[0]);

  const unsigned char *zNeedle;
  int nHaystack;
  int nNeedle;
  int typeHaystack, typeNeedle;
  int N = 1;
  int isText;

  UNUSED_PARAMETER(argc);
  typeHaystack = sqlite3_value_type(argv[0]);
  typeNeedle = sqlite3_value_type(argv[1]);
  if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
  nHaystack = sqlite3_value_bytes(argv[0]);
  nNeedle = sqlite3_value_bytes(argv[1]);
  if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
    zHaystack = sqlite3_value_blob(argv[0]);

  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
  Table *pTab,    /* The table to be opened */
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  if( IsVirtual(pTab) ) return;
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
  sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(pTab->nCol), P4_INT32);
  VdbeComment((v, "%s", pTab->zName));
}
................................................................................
#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->ckBase = regData;
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    for(i=0; i<pCheck->nExpr; i++){
      int allOk = sqlite3VdbeMakeLabel(v);
      Expr *pDup = sqlite3ExprDup(db, pCheck->a[i].pExpr, 0);
      if( !db->mallocFailed ){
        assert( pDup!=0 );
        sqlite3ExprIfTrue(pParse, pDup, allOk, SQLITE_JUMPIFNULL);
        if( onError==OE_Ignore ){
          sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        }else{
          char *zConsName = pCheck->a[i].zName;
          if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
          if( zConsName ){
            zConsName = sqlite3MPrintf(db, "constraint %s failed", zConsName);
          }else{
            zConsName = 0;
          }
          sqlite3HaltConstraint(pParse, onError, zConsName, P4_DYNAMIC);
        }
        sqlite3VdbeResolveLabel(v, allOk);
      }
      sqlite3ExprDelete(db, pDup);
    }
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
  ** of the new record does not previously exist.  Except, if this
  ** is an UPDATE and the primary key is not changing, that is OK.

  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
  Table *pTab,    /* The table to be opened */
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  assert( !IsVirtual(pTab) );
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
  sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
  sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(pTab->nCol), P4_INT32);
  VdbeComment((v, "%s", pTab->zName));
}
................................................................................
#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->ckBase = regData;
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    for(i=0; i<pCheck->nExpr; i++){
      int allOk = sqlite3VdbeMakeLabel(v);



      sqlite3ExprIfTrue(pParse, pCheck->a[i].pExpr, allOk, SQLITE_JUMPIFNULL);
      if( onError==OE_Ignore ){
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
      }else{
        char *zConsName = pCheck->a[i].zName;
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
        if( zConsName ){
          zConsName = sqlite3MPrintf(db, "constraint %s failed", zConsName);
        }else{
          zConsName = 0;
        }
        sqlite3HaltConstraint(pParse, onError, zConsName, P4_DYNAMIC);
      }
      sqlite3VdbeResolveLabel(v, allOk);


    }
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
  ** of the new record does not previously exist.  Except, if this
  ** is an UPDATE and the primary key is not changing, that is OK.

*/
int sqlite3JournalCreate(sqlite3_file *p){
  if( p->pMethods!=&JournalFileMethods ){
    return SQLITE_OK;
  }
  return createFile((JournalFile *)p);
}











/* 
** Return the number of bytes required to store a JournalFile that uses vfs
** pVfs to create the underlying on-disk files.
*/
int sqlite3JournalSize(sqlite3_vfs *pVfs){
  return (pVfs->szOsFile+sizeof(JournalFile));
}
#endif

*/
int sqlite3JournalCreate(sqlite3_file *p){
  if( p->pMethods!=&JournalFileMethods ){
    return SQLITE_OK;
  }
  return createFile((JournalFile *)p);
}

/*
** The file-handle passed as the only argument is guaranteed to be an open
** file. It may or may not be of class JournalFile. If the file is a
** JournalFile, and the underlying file on disk has not yet been opened,
** return 0. Otherwise, return 1.
*/
int sqlite3JournalExists(sqlite3_file *p){
  return (p->pMethods!=&JournalFileMethods || ((JournalFile *)p)->pReal!=0);
}

/* 
** Return the number of bytes required to store a JournalFile that uses vfs
** pVfs to create the underlying on-disk files.
*/
int sqlite3JournalSize(sqlite3_vfs *pVfs){
  return (pVfs->szOsFile+sizeof(JournalFile));
}
#endif

  }else if( (*pArg)==0 ){
    pFile->ctrlFlags &= ~mask;
  }else{
    pFile->ctrlFlags |= mask;
  }
}




/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  unixFile *pFile = (unixFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
      unixModeBit(pFile, UNIXFILE_PSOW, (int*)pArg);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_VFSNAME: {
      *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
      return SQLITE_OK;








    }
#ifdef SQLITE_DEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and
    ** it hence it is OK for the transaction change counter to be
    ** unchanged.
    */

  }else if( (*pArg)==0 ){
    pFile->ctrlFlags &= ~mask;
  }else{
    pFile->ctrlFlags |= mask;
  }
}

/* Forward declaration */
static int unixGetTempname(int nBuf, char *zBuf);

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  unixFile *pFile = (unixFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
      unixModeBit(pFile, UNIXFILE_PSOW, (int*)pArg);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_VFSNAME: {
      *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_TEMPFILENAME: {
      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
      if( zTFile ){
        unixGetTempname(pFile->pVfs->mxPathname, zTFile);
        *(char**)pArg = zTFile;
      }
      return SQLITE_OK;
    }
#ifdef SQLITE_DEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and
    ** it hence it is OK for the transaction change counter to be
    ** unchanged.
    */

  }else if( (*pArg)==0 ){
    pFile->ctrlFlags &= ~mask;
  }else{
    pFile->ctrlFlags |= mask;
  }
}




/*
** Control and query of the open file handle.
*/
static int winFileControl(sqlite3_file *id, int op, void *pArg){
  winFile *pFile = (winFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
      }
      if( a[1]>0 ){
        win32IoerrRetryDelay = a[1];
      }else{
        a[1] = win32IoerrRetryDelay;
      }
      return SQLITE_OK;








    }
  }
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for

  }else if( (*pArg)==0 ){
    pFile->ctrlFlags &= ~mask;
  }else{
    pFile->ctrlFlags |= mask;
  }
}

/* Forward declaration */
static int getTempname(int nBuf, char *zBuf);

/*
** Control and query of the open file handle.
*/
static int winFileControl(sqlite3_file *id, int op, void *pArg){
  winFile *pFile = (winFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
................................................................................
      }
      if( a[1]>0 ){
        win32IoerrRetryDelay = a[1];
      }else{
        a[1] = win32IoerrRetryDelay;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_TEMPFILENAME: {
      char *zTFile = sqlite3_malloc( pFile->pVfs->mxPathname );
      if( zTFile ){
        getTempname(pFile->pVfs->mxPathname, zTFile);
        *(char**)pArg = zTFile;
      }
      return SQLITE_OK;
    }
  }
  return SQLITE_NOTFOUND;
}

/*
** Return the sector size in bytes of the underlying block device for

      pPager->journalOff = 0;
    }else{
      /* This branch may be executed with Pager.journalMode==MEMORY if
      ** a hot-journal was just rolled back. In this case the journal
      ** file should be closed and deleted. If this connection writes to
      ** the database file, it will do so using an in-memory journal. 
      */

      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
           || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
           || pPager->journalMode==PAGER_JOURNALMODE_WAL 
      );
      sqlite3OsClose(pPager->jfd);
      if( !pPager->tempFile ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }
  }

#ifdef SQLITE_CHECK_PAGES
  sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash);
................................................................................
  pPager->xBusyHandler = xBusyHandler;
  pPager->pBusyHandlerArg = pBusyHandlerArg;

  if( isOpen(pPager->fd) ){
    void **ap = (void **)&pPager->xBusyHandler;
    assert( ((int(*)(void *))(ap[0]))==xBusyHandler );
    assert( ap[1]==pBusyHandlerArg );
    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_BUSYHANDLER, (void *)ap);
  }
}

/*
** Change the page size used by the Pager object. The new page size 
** is passed in *pPageSize.
**

      pPager->journalOff = 0;
    }else{
      /* This branch may be executed with Pager.journalMode==MEMORY if
      ** a hot-journal was just rolled back. In this case the journal
      ** file should be closed and deleted. If this connection writes to
      ** the database file, it will do so using an in-memory journal. 
      */
      int bDelete = (!pPager->tempFile && sqlite3JournalExists(pPager->jfd));
      assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 
           || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 
           || pPager->journalMode==PAGER_JOURNALMODE_WAL 
      );
      sqlite3OsClose(pPager->jfd);
      if( bDelete ){
        rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
      }
    }
  }

#ifdef SQLITE_CHECK_PAGES
  sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash);
................................................................................
  pPager->xBusyHandler = xBusyHandler;
  pPager->pBusyHandlerArg = pBusyHandlerArg;

  if( isOpen(pPager->fd) ){
    void **ap = (void **)&pPager->xBusyHandler;
    assert( ((int(*)(void *))(ap[0]))==xBusyHandler );
    assert( ap[1]==pBusyHandlerArg );
    sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_BUSYHANDLER, (void *)ap);
  }
}

/*
** Change the page size used by the Pager object. The new page size 
** is passed in *pPageSize.
**

}
expr(A) ::= VARIABLE(X).     {
  spanExpr(&A, pParse, TK_VARIABLE, &X);
  sqlite3ExprAssignVarNumber(pParse, A.pExpr);
  spanSet(&A, &X, &X);
}
expr(A) ::= expr(E) COLLATE ids(C). {
  A.pExpr = sqlite3ExprSetCollByToken(pParse, E.pExpr, &C);
  A.zStart = E.zStart;
  A.zEnd = &C.z[C.n];
}
%ifndef SQLITE_OMIT_CAST
expr(A) ::= CAST(X) LP expr(E) AS typetoken(T) RP(Y). {
  A.pExpr = sqlite3PExpr(pParse, TK_CAST, E.pExpr, 0, &T);
  spanSet(&A,&X,&Y);
................................................................................
%destructor idxlist {sqlite3ExprListDelete(pParse->db, $$);}
%type idxlist_opt {ExprList*}
%destructor idxlist_opt {sqlite3ExprListDelete(pParse->db, $$);}

idxlist_opt(A) ::= .                         {A = 0;}
idxlist_opt(A) ::= LP idxlist(X) RP.         {A = X;}
idxlist(A) ::= idxlist(X) COMMA nm(Y) collate(C) sortorder(Z).  {
  Expr *p = 0;
  if( C.n>0 ){
    p = sqlite3Expr(pParse->db, TK_COLUMN, 0);
    sqlite3ExprSetCollByToken(pParse, p, &C);
  }
  A = sqlite3ExprListAppend(pParse,X, p);
  sqlite3ExprListSetName(pParse,A,&Y,1);
  sqlite3ExprListCheckLength(pParse, A, "index");
  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
}
idxlist(A) ::= nm(Y) collate(C) sortorder(Z). {
  Expr *p = 0;
  if( C.n>0 ){
    p = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
    sqlite3ExprSetCollByToken(pParse, p, &C);
  }
  A = sqlite3ExprListAppend(pParse,0, p);
  sqlite3ExprListSetName(pParse, A, &Y, 1);
  sqlite3ExprListCheckLength(pParse, A, "index");
  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
}

%type collate {Token}

}
expr(A) ::= VARIABLE(X).     {
  spanExpr(&A, pParse, TK_VARIABLE, &X);
  sqlite3ExprAssignVarNumber(pParse, A.pExpr);
  spanSet(&A, &X, &X);
}
expr(A) ::= expr(E) COLLATE ids(C). {
  A.pExpr = sqlite3ExprAddCollateToken(pParse, E.pExpr, &C);
  A.zStart = E.zStart;
  A.zEnd = &C.z[C.n];
}
%ifndef SQLITE_OMIT_CAST
expr(A) ::= CAST(X) LP expr(E) AS typetoken(T) RP(Y). {
  A.pExpr = sqlite3PExpr(pParse, TK_CAST, E.pExpr, 0, &T);
  spanSet(&A,&X,&Y);
................................................................................
%destructor idxlist {sqlite3ExprListDelete(pParse->db, $$);}
%type idxlist_opt {ExprList*}
%destructor idxlist_opt {sqlite3ExprListDelete(pParse->db, $$);}

idxlist_opt(A) ::= .                         {A = 0;}
idxlist_opt(A) ::= LP idxlist(X) RP.         {A = X;}
idxlist(A) ::= idxlist(X) COMMA nm(Y) collate(C) sortorder(Z).  {
  Expr *p = sqlite3ExprAddCollateToken(pParse, 0, &C);




  A = sqlite3ExprListAppend(pParse,X, p);
  sqlite3ExprListSetName(pParse,A,&Y,1);
  sqlite3ExprListCheckLength(pParse, A, "index");
  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
}
idxlist(A) ::= nm(Y) collate(C) sortorder(Z). {
  Expr *p = sqlite3ExprAddCollateToken(pParse, 0, &C);




  A = sqlite3ExprListAppend(pParse,0, p);
  sqlite3ExprListSetName(pParse, A, &Y, 1);
  sqlite3ExprListCheckLength(pParse, A, "index");
  if( A ) A->a[A->nExpr-1].sortOrder = (u8)Z;
}

%type collate {Token}

** Is equivalent to:
**
**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
**
** The result of random()%5 in the GROUP BY clause is probably different
** from the result in the result-set.  We might fix this someday.  Or
** then again, we might not...









**
** The nSubquery parameter specifies how many levels of subquery the
** alias is removed from the original expression.  The usually value is
** zero but it might be more if the alias is contained within a subquery
** of the original expression.  The Expr.op2 field of TK_AGG_FUNCTION
** structures must be increased by the nSubquery amount.
*/
................................................................................
  sqlite3 *db;           /* The database connection */

  assert( iCol>=0 && iCol<pEList->nExpr );
  pOrig = pEList->a[iCol].pExpr;
  assert( pOrig!=0 );
  assert( pOrig->flags & EP_Resolved );
  db = pParse->db;
  if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
    pDup = sqlite3ExprDup(db, pOrig, 0);


    incrAggFunctionDepth(pDup, nSubquery);
    pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
    if( pDup==0 ) return;
    if( pEList->a[iCol].iAlias==0 ){
      pEList->a[iCol].iAlias = (u16)(++pParse->nAlias);
    }
    pDup->iTable = pEList->a[iCol].iAlias;
  }else if( ExprHasProperty(pOrig, EP_IntValue) || pOrig->u.zToken==0 ){
    pDup = sqlite3ExprDup(db, pOrig, 0);
    if( pDup==0 ) return;
  }else{
    char *zToken = pOrig->u.zToken;
    assert( zToken!=0 );
    pOrig->u.zToken = 0;
    pDup = sqlite3ExprDup(db, pOrig, 0);
    pOrig->u.zToken = zToken;
    if( pDup==0 ) return;
    assert( (pDup->flags & (EP_Reduced|EP_TokenOnly))==0 );
    pDup->flags2 |= EP2_MallocedToken;
    pDup->u.zToken = sqlite3DbStrDup(db, zToken);
  }
  if( pExpr->flags & EP_ExpCollate ){
    pDup->pColl = pExpr->pColl;
    pDup->flags |= EP_ExpCollate;


  }

  /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
  ** prevents ExprDelete() from deleting the Expr structure itself,
  ** allowing it to be repopulated by the memcpy() on the following line.



  */
  ExprSetProperty(pExpr, EP_Static);
  sqlite3ExprDelete(db, pExpr);
  memcpy(pExpr, pDup, sizeof(*pExpr));





  sqlite3DbFree(db, pDup);
}


/*
** Return TRUE if the name zCol occurs anywhere in the USING clause.
**
................................................................................
    moreToDo = 0;
    pEList = pSelect->pEList;
    assert( pEList!=0 );
    for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
      int iCol = -1;
      Expr *pE, *pDup;
      if( pItem->done ) continue;
      pE = pItem->pExpr;
      if( sqlite3ExprIsInteger(pE, &iCol) ){
        if( iCol<=0 || iCol>pEList->nExpr ){
          resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
          return 1;
        }
      }else{
        iCol = resolveAsName(pParse, pEList, pE);
................................................................................
            assert(pDup);
            iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
          }
          sqlite3ExprDelete(db, pDup);
        }
      }
      if( iCol>0 ){
        CollSeq *pColl = pE->pColl;
        int flags = pE->flags & EP_ExpCollate;
        sqlite3ExprDelete(db, pE);
        pItem->pExpr = pE = sqlite3Expr(db, TK_INTEGER, 0);
        if( pE==0 ) return 1;
        pE->pColl = pColl;
        pE->flags |= EP_IntValue | flags;
        pE->u.iValue = iCol;








        pItem->iOrderByCol = (u16)iCol;
        pItem->done = 1;
      }else{
        moreToDo = 1;
      }
    }
    pSelect = pSelect->pNext;
................................................................................
      /* If an AS-name match is found, mark this ORDER BY column as being
      ** a copy of the iCol-th result-set column.  The subsequent call to
      ** sqlite3ResolveOrderGroupBy() will convert the expression to a
      ** copy of the iCol-th result-set expression. */
      pItem->iOrderByCol = (u16)iCol;
      continue;
    }
    if( sqlite3ExprIsInteger(pE, &iCol) ){
      /* The ORDER BY term is an integer constant.  Again, set the column
      ** number so that sqlite3ResolveOrderGroupBy() will convert the
      ** order-by term to a copy of the result-set expression */
      if( iCol<1 ){
        resolveOutOfRangeError(pParse, zType, i+1, nResult);
        return 1;
      }
      pItem->iOrderByCol = (u16)iCol;
      continue;
    }

** Is equivalent to:
**
**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
**
** The result of random()%5 in the GROUP BY clause is probably different
** from the result in the result-set.  We might fix this someday.  Or
** then again, we might not...
**
** If the reference is followed by a COLLATE operator, then make sure
** the COLLATE operator is preserved.  For example:
**
**     SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;
**
** Should be transformed into:
**
**     SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;
**
** The nSubquery parameter specifies how many levels of subquery the
** alias is removed from the original expression.  The usually value is
** zero but it might be more if the alias is contained within a subquery
** of the original expression.  The Expr.op2 field of TK_AGG_FUNCTION
** structures must be increased by the nSubquery amount.
*/
................................................................................
  sqlite3 *db;           /* The database connection */

  assert( iCol>=0 && iCol<pEList->nExpr );
  pOrig = pEList->a[iCol].pExpr;
  assert( pOrig!=0 );
  assert( pOrig->flags & EP_Resolved );
  db = pParse->db;

  pDup = sqlite3ExprDup(db, pOrig, 0);
  if( pDup==0 ) return;
  if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
    incrAggFunctionDepth(pDup, nSubquery);
    pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
    if( pDup==0 ) return;
    if( pEList->a[iCol].iAlias==0 ){
      pEList->a[iCol].iAlias = (u16)(++pParse->nAlias);
    }
    pDup->iTable = pEList->a[iCol].iAlias;













  }



  if( pExpr->op==TK_COLLATE ){
    pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
  }

  /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
  ** prevents ExprDelete() from deleting the Expr structure itself,
  ** allowing it to be repopulated by the memcpy() on the following line.
  ** The pExpr->u.zToken might point into memory that will be freed by the
  ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to
  ** make a copy of the token before doing the sqlite3DbFree().
  */
  ExprSetProperty(pExpr, EP_Static);
  sqlite3ExprDelete(db, pExpr);
  memcpy(pExpr, pDup, sizeof(*pExpr));
  if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){
    assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 );
    pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken);
    pExpr->flags2 |= EP2_MallocedToken;
  }
  sqlite3DbFree(db, pDup);
}


/*
** Return TRUE if the name zCol occurs anywhere in the USING clause.
**
................................................................................
    moreToDo = 0;
    pEList = pSelect->pEList;
    assert( pEList!=0 );
    for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
      int iCol = -1;
      Expr *pE, *pDup;
      if( pItem->done ) continue;
      pE = sqlite3ExprSkipCollate(pItem->pExpr);
      if( sqlite3ExprIsInteger(pE, &iCol) ){
        if( iCol<=0 || iCol>pEList->nExpr ){
          resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
          return 1;
        }
      }else{
        iCol = resolveAsName(pParse, pEList, pE);
................................................................................
            assert(pDup);
            iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
          }
          sqlite3ExprDelete(db, pDup);
        }
      }
      if( iCol>0 ){
        /* Convert the ORDER BY term into an integer column number iCol,
        ** taking care to preserve the COLLATE clause if it exists */

        Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
        if( pNew==0 ) return 1;

        pNew->flags |= EP_IntValue;
        pNew->u.iValue = iCol;
        if( pItem->pExpr==pE ){
          pItem->pExpr = pNew;
        }else{
          assert( pItem->pExpr->op==TK_COLLATE );
          assert( pItem->pExpr->pLeft==pE );
          pItem->pExpr->pLeft = pNew;
        }
        sqlite3ExprDelete(db, pE);
        pItem->iOrderByCol = (u16)iCol;
        pItem->done = 1;
      }else{
        moreToDo = 1;
      }
    }
    pSelect = pSelect->pNext;
................................................................................
      /* If an AS-name match is found, mark this ORDER BY column as being
      ** a copy of the iCol-th result-set column.  The subsequent call to
      ** sqlite3ResolveOrderGroupBy() will convert the expression to a
      ** copy of the iCol-th result-set expression. */
      pItem->iOrderByCol = (u16)iCol;
      continue;
    }
    if( sqlite3ExprIsInteger(sqlite3ExprSkipCollate(pE), &iCol) ){
      /* The ORDER BY term is an integer constant.  Again, set the column
      ** number so that sqlite3ResolveOrderGroupBy() will convert the
      ** order-by term to a copy of the result-set expression */
      if( iCol<1 || iCol>0xffff ){
        resolveOutOfRangeError(pParse, zType, i+1, nResult);
        return 1;
      }
      pItem->iOrderByCol = (u16)iCol;
      continue;
    }

  }
  *pnCol = nCol;
  *paCol = aCol;

  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = pEList->a[i].pExpr;
    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)
               || p->pRight->u.zToken==0 || p->pRight->u.zToken[0]!=0 );
    if( (zName = pEList->a[i].zName)!=0 ){
      /* If the column contains an "AS <name>" phrase, use <name> as the name */
      zName = sqlite3DbStrDup(db, zName);
    }else{
      Expr *pColExpr = p;  /* The expression that is the result column name */
................................................................................
    if( pKeyMerge ){
      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
      pKeyMerge->nField = (u16)nOrderBy;
      pKeyMerge->enc = ENC(db);
      for(i=0; i<nOrderBy; i++){
        CollSeq *pColl;
        Expr *pTerm = pOrderBy->a[i].pExpr;
        if( pTerm->flags & EP_ExpCollate ){
          pColl = pTerm->pColl;
        }else{
          pColl = multiSelectCollSeq(pParse, p, aPermute[i]);
          pTerm->flags |= EP_ExpCollate;
          pTerm->pColl = pColl;

        }
        pKeyMerge->aColl[i] = pColl;
        pKeyMerge->aSortOrder[i] = pOrderBy->a[i].sortOrder;
      }
    }
  }else{
    pKeyMerge = 0;
................................................................................

  /* Implement the main merge loop
  */
  sqlite3VdbeResolveLabel(v, labelCmpr);
  sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
  sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
                         (char*)pKeyMerge, P4_KEYINFO_HANDOFF);

  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);

  /* Release temporary registers
  */
  if( regPrev ){
    sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1);
  }
................................................................................
    if( pExpr->iColumn<0 ){
      pExpr->op = TK_NULL;
    }else{
      Expr *pNew;
      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
      assert( pExpr->pLeft==0 && pExpr->pRight==0 );
      pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0);
      if( pNew && pExpr->pColl ){
        pNew->pColl = pExpr->pColl;
      }
      sqlite3ExprDelete(db, pExpr);
      pExpr = pNew;
    }
  }else{
    pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList);
    pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList);
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
................................................................................
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.
      */
      int addrTop;
      int addrEof;
      pItem->regReturn = ++pParse->nMem;
      addrEof = ++pParse->nMem;









      sqlite3VdbeAddOp0(v, OP_Goto);
      addrTop = sqlite3VdbeAddOp1(v, OP_OpenPseudo, pItem->iCursor);
      sqlite3VdbeChangeP5(v, 1);
      VdbeComment((v, "coroutine for %s", pItem->pTab->zName));
      pItem->addrFillSub = addrTop;
      sqlite3VdbeAddOp2(v, OP_Integer, 0, addrEof);
      sqlite3VdbeChangeP5(v, 1);

  }
  *pnCol = nCol;
  *paCol = aCol;

  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
    assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue)
               || p->pRight->u.zToken==0 || p->pRight->u.zToken[0]!=0 );
    if( (zName = pEList->a[i].zName)!=0 ){
      /* If the column contains an "AS <name>" phrase, use <name> as the name */
      zName = sqlite3DbStrDup(db, zName);
    }else{
      Expr *pColExpr = p;  /* The expression that is the result column name */
................................................................................
    if( pKeyMerge ){
      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
      pKeyMerge->nField = (u16)nOrderBy;
      pKeyMerge->enc = ENC(db);
      for(i=0; i<nOrderBy; i++){
        CollSeq *pColl;
        Expr *pTerm = pOrderBy->a[i].pExpr;
        if( pTerm->flags & EP_Collate ){
          pColl = sqlite3ExprCollSeq(pParse, pTerm);
        }else{
          pColl = multiSelectCollSeq(pParse, p, aPermute[i]);
          if( pColl==0 ) pColl = db->pDfltColl;
          pOrderBy->a[i].pExpr =
             sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);
        }
        pKeyMerge->aColl[i] = pColl;
        pKeyMerge->aSortOrder[i] = pOrderBy->a[i].sortOrder;
      }
    }
  }else{
    pKeyMerge = 0;
................................................................................

  /* Implement the main merge loop
  */
  sqlite3VdbeResolveLabel(v, labelCmpr);
  sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
  sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
                         (char*)pKeyMerge, P4_KEYINFO_HANDOFF);
  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);

  /* Release temporary registers
  */
  if( regPrev ){
    sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1);
  }
................................................................................
    if( pExpr->iColumn<0 ){
      pExpr->op = TK_NULL;
    }else{
      Expr *pNew;
      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
      assert( pExpr->pLeft==0 && pExpr->pRight==0 );
      pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0);



      sqlite3ExprDelete(db, pExpr);
      pExpr = pNew;
    }
  }else{
    pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList);
    pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList);
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
................................................................................
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.
      */
      int addrTop;
      int addrEof;
      pItem->regReturn = ++pParse->nMem;
      addrEof = ++pParse->nMem;
      /* Before coding the OP_Goto to jump to the start of the main routine,
      ** ensure that the jump to the verify-schema routine has already
      ** been coded. Otherwise, the verify-schema would likely be coded as 
      ** part of the co-routine. If the main routine then accessed the 
      ** database before invoking the co-routine for the first time (for 
      ** example to initialize a LIMIT register from a sub-select), it would 
      ** be doing so without having verified the schema version and obtained 
      ** the required db locks. See ticket d6b36be38.  */
      sqlite3CodeVerifySchema(pParse, -1);
      sqlite3VdbeAddOp0(v, OP_Goto);
      addrTop = sqlite3VdbeAddOp1(v, OP_OpenPseudo, pItem->iCursor);
      sqlite3VdbeChangeP5(v, 1);
      VdbeComment((v, "coroutine for %s", pItem->pTab->zName));
      pItem->addrFillSub = addrTop;
      sqlite3VdbeAddOp2(v, OP_Integer, 0, addrEof);
      sqlite3VdbeChangeP5(v, 1);

static void output_c_string(FILE *out, const char *z){
  unsigned int c;
  fputc('"', out);
  while( (c = *(z++))!=0 ){
    if( c=='\\' ){
      fputc(c, out);
      fputc(c, out);



    }else if( c=='\t' ){
      fputc('\\', out);
      fputc('t', out);
    }else if( c=='\n' ){
      fputc('\\', out);
      fputc('n', out);
    }else if( c=='\r' ){
................................................................................
      fprintf(p->out,"</TR>\n");
      break;
    }
    case MODE_Tcl: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          output_c_string(p->out,azCol[i] ? azCol[i] : "");
          fprintf(p->out, "%s", p->separator);
        }
        fprintf(p->out,"\n");
      }
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        output_c_string(p->out, azArg[i] ? azArg[i] : p->nullvalue);
        fprintf(p->out, "%s", p->separator);
      }
      fprintf(p->out,"\n");
      break;
    }
    case MODE_Csv: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
................................................................................
      p->mode = MODE_Column;
    }else if( n2==4 && strncmp(azArg[1],"list",n2)==0 ){
      p->mode = MODE_List;
    }else if( n2==4 && strncmp(azArg[1],"html",n2)==0 ){
      p->mode = MODE_Html;
    }else if( n2==3 && strncmp(azArg[1],"tcl",n2)==0 ){
      p->mode = MODE_Tcl;

    }else if( n2==3 && strncmp(azArg[1],"csv",n2)==0 ){
      p->mode = MODE_Csv;
      sqlite3_snprintf(sizeof(p->separator), p->separator, ",");
    }else if( n2==4 && strncmp(azArg[1],"tabs",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->separator), p->separator, "\t");
    }else if( n2==6 && strncmp(azArg[1],"insert",n2)==0 ){
................................................................................
  if( zSql ){
    if( !_all_whitespace(zSql) ){
      fprintf(stderr, "Error: incomplete SQL: %s\n", zSql);
    }
    free(zSql);
  }
  free(zLine);
  return errCnt;
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(void){

static void output_c_string(FILE *out, const char *z){
  unsigned int c;
  fputc('"', out);
  while( (c = *(z++))!=0 ){
    if( c=='\\' ){
      fputc(c, out);
      fputc(c, out);
    }else if( c=='"' ){
      fputc('\\', out);
      fputc('"', out);
    }else if( c=='\t' ){
      fputc('\\', out);
      fputc('t', out);
    }else if( c=='\n' ){
      fputc('\\', out);
      fputc('n', out);
    }else if( c=='\r' ){
................................................................................
      fprintf(p->out,"</TR>\n");
      break;
    }
    case MODE_Tcl: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          output_c_string(p->out,azCol[i] ? azCol[i] : "");
          if(i<nArg-1) fprintf(p->out, "%s", p->separator);
        }
        fprintf(p->out,"\n");
      }
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        output_c_string(p->out, azArg[i] ? azArg[i] : p->nullvalue);
        if(i<nArg-1) fprintf(p->out, "%s", p->separator);
      }
      fprintf(p->out,"\n");
      break;
    }
    case MODE_Csv: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
................................................................................
      p->mode = MODE_Column;
    }else if( n2==4 && strncmp(azArg[1],"list",n2)==0 ){
      p->mode = MODE_List;
    }else if( n2==4 && strncmp(azArg[1],"html",n2)==0 ){
      p->mode = MODE_Html;
    }else if( n2==3 && strncmp(azArg[1],"tcl",n2)==0 ){
      p->mode = MODE_Tcl;
      sqlite3_snprintf(sizeof(p->separator), p->separator, " ");
    }else if( n2==3 && strncmp(azArg[1],"csv",n2)==0 ){
      p->mode = MODE_Csv;
      sqlite3_snprintf(sizeof(p->separator), p->separator, ",");
    }else if( n2==4 && strncmp(azArg[1],"tabs",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->separator), p->separator, "\t");
    }else if( n2==6 && strncmp(azArg[1],"insert",n2)==0 ){
................................................................................
  if( zSql ){
    if( !_all_whitespace(zSql) ){
      fprintf(stderr, "Error: incomplete SQL: %s\n", zSql);
    }
    free(zSql);
  }
  free(zLine);
  return errCnt>0;
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(void){

** VFS has handled the PRAGMA itself and the parser generates a no-op
** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
** that the VFS encountered an error while handling the [PRAGMA] and the
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
** file control occurs at the beginning of pragma statement analysis and so
** it is able to override built-in [PRAGMA] statements.
** </ul>
**
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
** ^This file-control may be invoked by SQLite on the database file handle
** shortly after it is opened in order to provide a custom VFS with access
** to the connections busy-handler callback. The argument is of type (void **)
** - an array of two (void *) values. The first (void *) actually points
** to a function of type (int (*)(void *)). In order to invoke the connections
** busy-handler, this function should be invoked with the second (void *) in
** the array as the only argument. If it returns non-zero, then the operation
** should be retried. If it returns zero, the custom VFS should abandon the
** current operation.










*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
................................................................................
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

** VFS has handled the PRAGMA itself and the parser generates a no-op
** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
** that the VFS encountered an error while handling the [PRAGMA] and the
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
** file control occurs at the beginning of pragma statement analysis and so
** it is able to override built-in [PRAGMA] statements.

**
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
** ^This file-control may be invoked by SQLite on the database file handle
** shortly after it is opened in order to provide a custom VFS with access
** to the connections busy-handler callback. The argument is of type (void **)
** - an array of two (void *) values. The first (void *) actually points
** to a function of type (int (*)(void *)). In order to invoke the connections
** busy-handler, this function should be invoked with the second (void *) in
** the array as the only argument. If it returns non-zero, then the operation
** should be retried. If it returns zero, the custom VFS should abandon the
** current operation.
**
** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
** ^Application can invoke this file-control to have SQLite generate a
** temporary filename using the same algorithm that is followed to generate
** temporary filenames for TEMP tables and other internal uses.  The
** argument should be a char** which will be filled with the filename
** written into memory obtained from [sqlite3_malloc()].  The caller should
** invoke [sqlite3_free()] on the result to avoid a memory leak.
**
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
................................................................................
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15
#define SQLITE_FCNTL_TEMPFILENAME           16

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

#define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */

/*
** A "Collating Sequence" is defined by an instance of the following
** structure. Conceptually, a collating sequence consists of a name and
** a comparison routine that defines the order of that sequence.
**
** There may two separate implementations of the collation function, one
** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
** native byte order. When a collation sequence is invoked, SQLite selects
** the version that will require the least expensive encoding
** translations, if any.
**
** The CollSeq.pUser member variable is an extra parameter that passed in
** as the first argument to the UTF-8 comparison function, xCmp.
** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
** xCmp16.
**
** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
** collating sequence is undefined.  Indices built on an undefined
** collating sequence may not be read or written.
*/
struct CollSeq {
  char *zName;          /* Name of the collating sequence, UTF-8 encoded */
  u8 enc;               /* Text encoding handled by xCmp() */
  void *pUser;          /* First argument to xCmp() */
................................................................................

  Expr *pLeft;           /* Left subnode */
  Expr *pRight;          /* Right subnode */
  union {
    ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
    Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
  } x;
  CollSeq *pColl;        /* The collation type of the column or 0 */

  /* If the EP_Reduced flag is set in the Expr.flags mask, then no
  ** space is allocated for the fields below this point. An attempt to
  ** access them will result in a segfault or malfunction.
  *********************************************************************/

#if SQLITE_MAX_EXPR_DEPTH>0
................................................................................
#define EP_Agg        0x0002  /* Contains one or more aggregate functions */
#define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
#define EP_Error      0x0008  /* Expression contains one or more errors */
#define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
#define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
#define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
#define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
#define EP_FixedDest  0x0200  /* Result needed in a specific register */
#define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
#define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
#define EP_Hint       0x1000  /* Not used */
#define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
#define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
................................................................................
#define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
#define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
#define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */
#define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
#define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
#define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
#define OPFLAG_P2ISREG       0x02    /* P2 to OP_Open** is a register number */


/*
 * Each trigger present in the database schema is stored as an instance of
 * struct Trigger. 
 *
 * Pointers to instances of struct Trigger are stored in two ways.
 * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
................................................................................
u8 sqlite3HexToInt(int h);
int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
const char *sqlite3ErrStr(int);
int sqlite3ReadSchema(Parse *pParse);
CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprSetColl(Expr*, CollSeq*);

Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);
int sqlite3AddInt64(i64*,i64);
int sqlite3SubInt64(i64*,i64);
int sqlite3MulInt64(i64*,i64);
int sqlite3AbsInt32(int);
................................................................................
#define IN_INDEX_INDEX           3
int sqlite3FindInIndex(Parse *, Expr *, int*);

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

#else
  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)

#endif

void sqlite3MemJournalOpen(sqlite3_file *);
int sqlite3MemJournalSize(void);
int sqlite3IsMemJournal(sqlite3_file *);

#if SQLITE_MAX_EXPR_DEPTH>0

#define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */

/*
** A "Collating Sequence" is defined by an instance of the following
** structure. Conceptually, a collating sequence consists of a name and
** a comparison routine that defines the order of that sequence.
**












** If CollSeq.xCmp is NULL, it means that the
** collating sequence is undefined.  Indices built on an undefined
** collating sequence may not be read or written.
*/
struct CollSeq {
  char *zName;          /* Name of the collating sequence, UTF-8 encoded */
  u8 enc;               /* Text encoding handled by xCmp() */
  void *pUser;          /* First argument to xCmp() */
................................................................................

  Expr *pLeft;           /* Left subnode */
  Expr *pRight;          /* Right subnode */
  union {
    ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
    Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
  } x;


  /* If the EP_Reduced flag is set in the Expr.flags mask, then no
  ** space is allocated for the fields below this point. An attempt to
  ** access them will result in a segfault or malfunction.
  *********************************************************************/

#if SQLITE_MAX_EXPR_DEPTH>0
................................................................................
#define EP_Agg        0x0002  /* Contains one or more aggregate functions */
#define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
#define EP_Error      0x0008  /* Expression contains one or more errors */
#define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
#define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
#define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate    0x0100  /* Tree contains a TK_COLLATE opeartor */
#define EP_FixedDest  0x0200  /* Result needed in a specific register */
#define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
#define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
#define EP_Hint       0x1000  /* Not used */
#define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
#define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
................................................................................
#define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
#define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
#define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */
#define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
#define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
#define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
#define OPFLAG_P2ISREG       0x02    /* P2 to OP_Open** is a register number */
#define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */

/*
 * Each trigger present in the database schema is stored as an instance of
 * struct Trigger. 
 *
 * Pointers to instances of struct Trigger are stored in two ways.
 * 1. In the "trigHash" hash table (part of the sqlite3* that represents the 
................................................................................
u8 sqlite3HexToInt(int h);
int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
const char *sqlite3ErrStr(int);
int sqlite3ReadSchema(Parse *pParse);
CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, Token*);
Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
Expr *sqlite3ExprSkipCollate(Expr*);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);
int sqlite3AddInt64(i64*,i64);
int sqlite3SubInt64(i64*,i64);
int sqlite3MulInt64(i64*,i64);
int sqlite3AbsInt32(int);
................................................................................
#define IN_INDEX_INDEX           3
int sqlite3FindInIndex(Parse *, Expr *, int*);

#ifdef SQLITE_ENABLE_ATOMIC_WRITE
  int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
  int sqlite3JournalSize(sqlite3_vfs *);
  int sqlite3JournalCreate(sqlite3_file *);
  int sqlite3JournalExists(sqlite3_file *p);
#else
  #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
  #define sqlite3JournalExists(p) 1
#endif

void sqlite3MemJournalOpen(sqlite3_file *);
int sqlite3MemJournalSize(void);
int sqlite3IsMemJournal(sqlite3_file *);

#if SQLITE_MAX_EXPR_DEPTH>0

  }
  sqlite3_file_control(db, zDbName, SQLITE_FCNTL_VFSNAME,(void*)&zVfsName);
  Tcl_AppendResult(interp, zVfsName, (char*)0);
  sqlite3_free(zVfsName);
  return TCL_OK;  
}


































/*
** tclcmd:   sqlite3_vfs_list
**
**   Return a tcl list containing the names of all registered vfs's.
*/
static int vfs_list(
................................................................................
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },
     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test",  file_control_sizehint_test,   0   },
     { "file_control_win32_av_retry", file_control_win32_av_retry,  0   },
     { "file_control_persist_wal",    file_control_persist_wal,     0   },
     { "file_control_powersafe_overwrite",file_control_powersafe_overwrite,0},
     { "file_control_vfsname",        file_control_vfsname,         0   },

     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },

     /* Functions from os.h */
#ifndef SQLITE_OMIT_UTF16
     { "add_test_collate",        test_collate, 0            },
     { "add_test_collate_needed", test_collate_needed, 0     },

  }
  sqlite3_file_control(db, zDbName, SQLITE_FCNTL_VFSNAME,(void*)&zVfsName);
  Tcl_AppendResult(interp, zVfsName, (char*)0);
  sqlite3_free(zVfsName);
  return TCL_OK;  
}

/*
** tclcmd:   file_control_tempfilename DB ?AUXDB?
**
** Return a string that is a temporary filename
*/
static int file_control_tempfilename(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  const char *zDbName = "main";
  char *zTName = 0;

  if( objc!=2 && objc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " DB ?AUXDB?", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  if( objc==3 ){
    zDbName = Tcl_GetString(objv[2]);
  }
  sqlite3_file_control(db, zDbName, SQLITE_FCNTL_TEMPFILENAME, (void*)&zTName);
  Tcl_AppendResult(interp, zTName, (char*)0);
  sqlite3_free(zTName);
  return TCL_OK;  
}


/*
** tclcmd:   sqlite3_vfs_list
**
**   Return a tcl list containing the names of all registered vfs's.
*/
static int vfs_list(
................................................................................
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },
     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test",  file_control_sizehint_test,   0   },
     { "file_control_win32_av_retry", file_control_win32_av_retry,  0   },
     { "file_control_persist_wal",    file_control_persist_wal,     0   },
     { "file_control_powersafe_overwrite",file_control_powersafe_overwrite,0},
     { "file_control_vfsname",        file_control_vfsname,         0   },
     { "file_control_tempfilename",   file_control_tempfilename,    0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },

     /* Functions from os.h */
#ifndef SQLITE_OMIT_UTF16
     { "add_test_collate",        test_collate, 0            },
     { "add_test_collate_needed", test_collate_needed, 0     },

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "TITLE");
    return TCL_ERROR;
  }
#ifdef SQLITE_MEMDEBUG
  {
    const char *zTitle;
    zTitle = Tcl_GetString(objv[1]);
    extern int sqlite3MemdebugSettitle(const char*);

    sqlite3MemdebugSettitle(zTitle);
  }
#endif
  return TCL_OK;
}

#define MALLOC_LOG_FRAMES  10 

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "TITLE");
    return TCL_ERROR;
  }
#ifdef SQLITE_MEMDEBUG
  {
    const char *zTitle;

    extern int sqlite3MemdebugSettitle(const char*);
    zTitle = Tcl_GetString(objv[1]);
    sqlite3MemdebugSettitle(zTitle);
  }
#endif
  return TCL_OK;
}

#define MALLOC_LOG_FRAMES  10 

  }
}

/*
** The SQLITE_CONFIG_SQLLOG callback registered by sqlite3_init_sqllog().
*/
static void testSqllog(void *pCtx, sqlite3 *db, const char *zSql, int eType){
  struct SLConn *p;
  sqlite3_mutex *master = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);

  assert( eType==0 || eType==1 || eType==2 );
  assert( (eType==2)==(zSql==0) );

  /* This is a database open command. */
  if( eType==0 ){

  }
}

/*
** The SQLITE_CONFIG_SQLLOG callback registered by sqlite3_init_sqllog().
*/
static void testSqllog(void *pCtx, sqlite3 *db, const char *zSql, int eType){
  struct SLConn *p = 0;
  sqlite3_mutex *master = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);

  assert( eType==0 || eType==1 || eType==2 );
  assert( (eType==2)==(zSql==0) );

  /* This is a database open command. */
  if( eType==0 ){

    }
    case SQLITE_FCNTL_FILE_POINTER: zOp = "FILE_POINTER";       break;
    case SQLITE_FCNTL_SYNC_OMITTED: zOp = "SYNC_OMITTED";       break;
    case SQLITE_FCNTL_WIN32_AV_RETRY: zOp = "WIN32_AV_RETRY";   break;
    case SQLITE_FCNTL_PERSIST_WAL:  zOp = "PERSIST_WAL";        break;
    case SQLITE_FCNTL_OVERWRITE:    zOp = "OVERWRITE";          break;
    case SQLITE_FCNTL_VFSNAME:      zOp = "VFSNAME";            break;

    case 0xca093fa0:                zOp = "DB_UNCHANGED";       break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
................................................................................
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
  }

  if( op==SQLITE_FCNTL_PRAGMA && rc==SQLITE_OK && *(char**)pArg ){
    vfstrace_printf(pInfo, "%s.xFileControl(%s,%s) returns %s",
                    pInfo->zVfsName, p->zFName, zOp, *(char**)pArg);
  }
  return rc;
}

/*

    }
    case SQLITE_FCNTL_FILE_POINTER: zOp = "FILE_POINTER";       break;
    case SQLITE_FCNTL_SYNC_OMITTED: zOp = "SYNC_OMITTED";       break;
    case SQLITE_FCNTL_WIN32_AV_RETRY: zOp = "WIN32_AV_RETRY";   break;
    case SQLITE_FCNTL_PERSIST_WAL:  zOp = "PERSIST_WAL";        break;
    case SQLITE_FCNTL_OVERWRITE:    zOp = "OVERWRITE";          break;
    case SQLITE_FCNTL_VFSNAME:      zOp = "VFSNAME";            break;
    case SQLITE_FCNTL_TEMPFILENAME: zOp = "TEMPFILENAME";       break;
    case 0xca093fa0:                zOp = "DB_UNCHANGED";       break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
................................................................................
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
  }
  if( (op==SQLITE_FCNTL_PRAGMA || op==SQLITE_FCNTL_TEMPFILENAME)
   && rc==SQLITE_OK && *(char**)pArg ){
    vfstrace_printf(pInfo, "%s.xFileControl(%s,%s) returns %s",
                    pInfo->zVfsName, p->zFName, zOp, *(char**)pArg);
  }
  return rc;
}

/*

    **     INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
    **   END;
    **
    **   INSERT INTO t1 ... ;            -- insert into t2 uses REPLACE policy
    **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy
    */
    pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;










    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 

    **     INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
    **   END;
    **
    **   INSERT INTO t1 ... ;            -- insert into t2 uses REPLACE policy
    **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy
    */
    pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;

    /* Clear the cookieGoto flag. When coding triggers, the cookieGoto 
    ** variable is used as a flag to indicate to sqlite3ExprCodeConstants()
    ** that it is not safe to refactor constants (this happens after the
    ** start of the first loop in the SQL statement is coded - at that 
    ** point code may be conditionally executed, so it is no longer safe to 
    ** initialize constant register values).  */
    assert( pParse->cookieGoto==0 || pParse->cookieGoto==-1 );
    pParse->cookieGoto = 0;

    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 

#endif

#ifdef SQLITE_DEBUG
/*
** Print the value of a register for tracing purposes:
*/
static void memTracePrint(FILE *out, Mem *p){


  if( p->flags & MEM_Null ){
    fprintf(out, " NULL");
  }else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
    fprintf(out, " si:%lld", p->u.i);
  }else if( p->flags & MEM_Int ){
    fprintf(out, " i:%lld", p->u.i);
#ifndef SQLITE_OMIT_FLOATING_POINT
  }else if( p->flags & MEM_Real ){
................................................................................
  n = pOp->p3;
  pIn1 = &aMem[pOp->p1];
  pOut = &aMem[pOp->p2];
  assert( pOut!=pIn1 );
  while( 1 ){
    sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
    Deephemeralize(pOut);



    REGISTER_TRACE(pOp->p2+pOp->p3-n, pOut);
    if( (n--)==0 ) break;
    pOut++;
    pIn1++;
  }
  break;
}
................................................................................
}

/* Opcode: Permutation * * * P4 *
**
** Set the permutation used by the OP_Compare operator to be the array
** of integers in P4.
**
** The permutation is only valid until the next OP_Permutation, OP_Compare,
** OP_Halt, or OP_ResultRow.  Typically the OP_Permutation should occur
** immediately prior to the OP_Compare.
*/
case OP_Permutation: {
  assert( pOp->p4type==P4_INTARRAY );
  assert( pOp->p4.ai );
  aPermute = pOp->p4.ai;
  break;
}

/* Opcode: Compare P1 P2 P3 P4 *
**
** Compare two vectors of registers in reg(P1)..reg(P1+P3-1) (call this
** vector "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of
** the comparison for use by the next OP_Jump instruct.





**
** P4 is a KeyInfo structure that defines collating sequences and sort
** orders for the comparison.  The permutation applies to registers
** only.  The KeyInfo elements are used sequentially.
**
** The comparison is a sort comparison, so NULLs compare equal,
** NULLs are less than numbers, numbers are less than strings,
................................................................................
  int p1;
  int p2;
  const KeyInfo *pKeyInfo;
  int idx;
  CollSeq *pColl;    /* Collating sequence to use on this term */
  int bRev;          /* True for DESCENDING sort order */


  n = pOp->p3;
  pKeyInfo = pOp->p4.pKeyInfo;
  assert( n>0 );
  assert( pKeyInfo!=0 );
  p1 = pOp->p1;
  p2 = pOp->p2;
#if SQLITE_DEBUG
................................................................................
    }
  }
  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  pCx->isIndex = !pCx->isTable;
  break;
}

/* Opcode: OpenSorter P1 P2 * P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large
** tables using an external merge-sort algorithm.
*/
case OP_SorterOpen: {
  VdbeCursor *pCx;

#endif

#ifdef SQLITE_DEBUG
/*
** Print the value of a register for tracing purposes:
*/
static void memTracePrint(FILE *out, Mem *p){
  if( p->flags & MEM_Invalid ){
    fprintf(out, " undefined");
  }else if( p->flags & MEM_Null ){
    fprintf(out, " NULL");
  }else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
    fprintf(out, " si:%lld", p->u.i);
  }else if( p->flags & MEM_Int ){
    fprintf(out, " i:%lld", p->u.i);
#ifndef SQLITE_OMIT_FLOATING_POINT
  }else if( p->flags & MEM_Real ){
................................................................................
  n = pOp->p3;
  pIn1 = &aMem[pOp->p1];
  pOut = &aMem[pOp->p2];
  assert( pOut!=pIn1 );
  while( 1 ){
    sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
    Deephemeralize(pOut);
#ifdef SQLITE_DEBUG
    pOut->pScopyFrom = 0;
#endif
    REGISTER_TRACE(pOp->p2+pOp->p3-n, pOut);
    if( (n--)==0 ) break;
    pOut++;
    pIn1++;
  }
  break;
}
................................................................................
}

/* Opcode: Permutation * * * P4 *
**
** Set the permutation used by the OP_Compare operator to be the array
** of integers in P4.
**
** The permutation is only valid until the next OP_Compare that has
** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 
** occur immediately prior to the OP_Compare.
*/
case OP_Permutation: {
  assert( pOp->p4type==P4_INTARRAY );
  assert( pOp->p4.ai );
  aPermute = pOp->p4.ai;
  break;
}

/* Opcode: Compare P1 P2 P3 P4 P5
**
** Compare two vectors of registers in reg(P1)..reg(P1+P3-1) (call this
** vector "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of
** the comparison for use by the next OP_Jump instruct.
**
** If P5 has the OPFLAG_PERMUTE bit set, then the order of comparison is
** determined by the most recent OP_Permutation operator.  If the
** OPFLAG_PERMUTE bit is clear, then register are compared in sequential
** order.
**
** P4 is a KeyInfo structure that defines collating sequences and sort
** orders for the comparison.  The permutation applies to registers
** only.  The KeyInfo elements are used sequentially.
**
** The comparison is a sort comparison, so NULLs compare equal,
** NULLs are less than numbers, numbers are less than strings,
................................................................................
  int p1;
  int p2;
  const KeyInfo *pKeyInfo;
  int idx;
  CollSeq *pColl;    /* Collating sequence to use on this term */
  int bRev;          /* True for DESCENDING sort order */

  if( (pOp->p5 & OPFLAG_PERMUTE)==0 ) aPermute = 0;
  n = pOp->p3;
  pKeyInfo = pOp->p4.pKeyInfo;
  assert( n>0 );
  assert( pKeyInfo!=0 );
  p1 = pOp->p1;
  p2 = pOp->p2;
#if SQLITE_DEBUG
................................................................................
    }
  }
  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  pCx->isIndex = !pCx->isTable;
  break;
}

/* Opcode: SorterOpen P1 P2 * P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large
** tables using an external merge-sort algorithm.
*/
case OP_SorterOpen: {
  VdbeCursor *pCx;

  }
  assert( p->nOp>0 );
  assert( addr<p->nOp );
  if( addr<0 ){
    addr = p->nOp - 1;
  }
  pOp = &p->aOp[addr];

  freeP4(db, pOp->p4type, pOp->p4.p);
  pOp->p4.p = 0;
  if( n==P4_INT32 ){
    /* Note: this cast is safe, because the origin data point was an int
    ** that was cast to a (const char *). */
    pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
    pOp->p4type = P4_INT32;
................................................................................
      int i, j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      assert( pKeyInfo->aSortOrder!=0 );
      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
      i = sqlite3Strlen30(zTemp);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        if( pColl ){
          int n = sqlite3Strlen30(pColl->zName);
          if( i+n>nTemp-6 ){
            memcpy(&zTemp[i],",...",4);
            break;
          }
          zTemp[i++] = ',';
          if( pKeyInfo->aSortOrder[j] ){
            zTemp[i++] = '-';
          }
          memcpy(&zTemp[i], pColl->zName,n+1);
          i += n;
        }else if( i+4<nTemp-6 ){
          memcpy(&zTemp[i],",nil",4);
          i += 4;
        }
      }
      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );
      break;
    }
    case P4_COLLSEQ: {
................................................................................
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aLabel);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);
#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
  sqlite3DbFree(db, p->zExplain);
  sqlite3DbFree(db, p->pExplain);
#endif
}

/*
** Delete an entire VDBE.
*/

  }
  assert( p->nOp>0 );
  assert( addr<p->nOp );
  if( addr<0 ){
    addr = p->nOp - 1;
  }
  pOp = &p->aOp[addr];
  assert( pOp->p4type==P4_NOTUSED || pOp->p4type==P4_INT32 );
  freeP4(db, pOp->p4type, pOp->p4.p);
  pOp->p4.p = 0;
  if( n==P4_INT32 ){
    /* Note: this cast is safe, because the origin data point was an int
    ** that was cast to a (const char *). */
    pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
    pOp->p4type = P4_INT32;
................................................................................
      int i, j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      assert( pKeyInfo->aSortOrder!=0 );
      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
      i = sqlite3Strlen30(zTemp);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        const char *zColl = pColl ? pColl->zName : "nil";
        int n = sqlite3Strlen30(zColl);
        if( i+n>nTemp-6 ){
          memcpy(&zTemp[i],",...",4);
          break;
        }
        zTemp[i++] = ',';
        if( pKeyInfo->aSortOrder[j] ){
          zTemp[i++] = '-';
        }
        memcpy(&zTemp[i], zColl, n+1);
        i += n;




      }
      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );
      break;
    }
    case P4_COLLSEQ: {
................................................................................
  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aLabel);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
  sqlite3DbFree(db, p->pFree);
#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
  sqlite3_free(p->zExplain);
  sqlite3DbFree(db, p->pExplain);
#endif
}

/*
** Delete an entire VDBE.
*/

*/
#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}

/*
** Commute a comparison operator.  Expressions of the form "X op Y"
** are converted into "Y op X".
**
** If a collation sequence is associated with either the left or right

** side of the comparison, it remains associated with the same side after
** the commutation. So "Y collate NOCASE op X" becomes 
** "X collate NOCASE op Y". This is because any collation sequence on
** the left hand side of a comparison overrides any collation sequence 
** attached to the right. For the same reason the EP_ExpCollate flag
** is not commuted.
*/
static void exprCommute(Parse *pParse, Expr *pExpr){
  u16 expRight = (pExpr->pRight->flags & EP_ExpCollate);
  u16 expLeft = (pExpr->pLeft->flags & EP_ExpCollate);
  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
  pExpr->pRight->pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);





  pExpr->pLeft->pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
  SWAP(CollSeq*,pExpr->pRight->pColl,pExpr->pLeft->pColl);
  pExpr->pRight->flags = (pExpr->pRight->flags & ~EP_ExpCollate) | expLeft;



  pExpr->pLeft->flags = (pExpr->pLeft->flags & ~EP_ExpCollate) | expRight;


  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
  if( pExpr->op>=TK_GT ){
    assert( TK_LT==TK_GT+2 );
    assert( TK_GE==TK_LE+2 );
    assert( TK_GT>TK_EQ );
    assert( TK_GT<TK_LE );
    assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
................................................................................
  
          /* Figure out the collation sequence required from an index for
          ** it to be useful for optimising expression pX. Store this
          ** value in variable pColl.
          */
          assert(pX->pLeft);
          pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
          assert(pColl || pParse->nErr);
  
          for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
            if( NEVER(j>=pIdx->nColumn) ) return 0;
          }
          if( pColl && sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
        }
        return pTerm;
      }
    }
  }
  return 0;
}
................................................................................
  sqlite3 *db = pParse->db;        /* Database connection */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = pWC->pMaskSet;
  pExpr = pTerm->pExpr;
  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
  op = pExpr->op;
  if( op==TK_IN ){
    assert( pExpr->pRight==0 );
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
      pTerm->prereqRight = exprSelectTableUsage(pMaskSet, pExpr->x.pSelect);
    }else{
................................................................................
                       ** on left table of a LEFT JOIN.  Ticket #3015 */
  }
  pTerm->prereqAll = prereqAll;
  pTerm->leftCursor = -1;
  pTerm->iParent = -1;
  pTerm->eOperator = 0;
  if( allowedOp(op) && (pTerm->prereqRight & prereqLeft)==0 ){
    Expr *pLeft = pExpr->pLeft;
    Expr *pRight = pExpr->pRight;
    if( pLeft->op==TK_COLUMN ){
      pTerm->leftCursor = pLeft->iTable;
      pTerm->u.leftColumn = pLeft->iColumn;
      pTerm->eOperator = operatorMask(op);
    }
    if( pRight && pRight->op==TK_COLUMN ){
      WhereTerm *pNew;
................................................................................
        pTerm->nChild = 1;
        pTerm->wtFlags |= TERM_COPIED;
      }else{
        pDup = pExpr;
        pNew = pTerm;
      }
      exprCommute(pParse, pDup);
      pLeft = pDup->pLeft;
      pNew->leftCursor = pLeft->iTable;
      pNew->u.leftColumn = pLeft->iColumn;
      testcase( (prereqLeft | extraRight) != prereqLeft );
      pNew->prereqRight = prereqLeft | extraRight;
      pNew->prereqAll = prereqAll;
      pNew->eOperator = operatorMask(pDup->op);
    }
................................................................................
  ){
    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
    Expr *pNewExpr1;
    Expr *pNewExpr2;
    int idxNew1;
    int idxNew2;
    CollSeq *pColl;    /* Collating sequence to use */

    pLeft = pExpr->x.pList->a[1].pExpr;
    pStr2 = sqlite3ExprDup(db, pStr1, 0);
    if( !db->mallocFailed ){
      u8 c, *pC;       /* Last character before the first wildcard */
      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
      c = *pC;
................................................................................
        if( c=='A'-1 ) isComplete = 0;   /* EV: R-64339-08207 */


        c = sqlite3UpperToLower[c];
      }
      *pC = c + 1;
    }
    pColl = sqlite3FindCollSeq(db, SQLITE_UTF8, noCase ? "NOCASE" : "BINARY",0);


    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 
                     sqlite3ExprSetColl(sqlite3ExprDup(db,pLeft,0), pColl),

                     pStr1, 0);
    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew1==0 );
    exprAnalyze(pSrc, pWC, idxNew1);

    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
                     sqlite3ExprSetColl(sqlite3ExprDup(db,pLeft,0), pColl),

                     pStr2, 0);
    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew2==0 );
    exprAnalyze(pSrc, pWC, idxNew2);
    pTerm = &pWC->a[idxTerm];
    if( isComplete ){
      pWC->a[idxNew1].iParent = idxTerm;
      pWC->a[idxNew2].iParent = idxTerm;
................................................................................
  Index *pIdx,                    /* Index to match column of */
  int iCol                        /* Column of index to match */
){
  int i;
  const char *zColl = pIdx->azColl[iCol];

  for(i=0; i<pList->nExpr; i++){
    Expr *p = pList->a[i].pExpr;
    if( p->op==TK_COLUMN
     && p->iColumn==pIdx->aiColumn[iCol]
     && p->iTable==iBase
    ){
      CollSeq *pColl = sqlite3ExprCollSeq(pParse, p);
      if( ALWAYS(pColl) && 0==sqlite3StrICmp(pColl->zName, zColl) ){
        return i;
      }
    }
  }

  return -1;
................................................................................
  ** can be ignored. If it does not, and the column does not belong to the
  ** same table as index pIdx, return early. Finally, if there is no
  ** matching "col=X" expression and the column is on the same table as pIdx,
  ** set the corresponding bit in variable mask.
  */
  for(i=0; i<pDistinct->nExpr; i++){
    WhereTerm *pTerm;
    Expr *p = pDistinct->a[i].pExpr;
    if( p->op!=TK_COLUMN ) return 0;
    pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0);
    if( pTerm ){
      Expr *pX = pTerm->pExpr;
      CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
      CollSeq *p2 = sqlite3ExprCollSeq(pParse, p);
      if( p1==p2 ) continue;
................................................................................
  pTab = pTabList->a[0].pTab;

  /* If any of the expressions is an IPK column on table iBase, then return 
  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
  ** current SELECT is a correlated sub-query.
  */
  for(i=0; i<pDistinct->nExpr; i++){
    Expr *p = pDistinct->a[i].pExpr;
    if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
  }

  /* Loop through all indices on the table, checking each to see if it makes
  ** the DISTINCT qualifier redundant. It does so if:
  **
  **   1. The index is itself UNIQUE, and
................................................................................
    int isMatch;            /* ORDER BY term matches the index term */
    const char *zColl;      /* Name of collating sequence for i-th index term */
    WhereTerm *pConstraint; /* A constraint in the WHERE clause */

    /* If the next term of the ORDER BY clause refers to anything other than
    ** a column in the "base" table, then this index will not be of any
    ** further use in handling the ORDER BY. */
    pOBExpr = pOBItem->pExpr;
    if( pOBExpr->op!=TK_COLUMN || pOBExpr->iTable!=base ){
      break;
    }

    /* Find column number and collating sequence for the next entry
    ** in the index */
    if( pIdx->zName && i<pIdx->nColumn ){
................................................................................
    }

    /* Check to see if the column number and collating sequence of the
    ** index match the column number and collating sequence of the ORDER BY
    ** clause entry.  Set isMatch to 1 if they both match. */
    if( pOBExpr->iColumn==iColumn ){
      if( zColl ){
        pColl = sqlite3ExprCollSeq(pParse, pOBExpr);
        if( !pColl ) pColl = db->pDfltColl;
        isMatch = sqlite3StrICmp(pColl->zName, zColl)==0;
      }else{
        isMatch = 1;
      }
    }else{
      isMatch = 0;
................................................................................
  Index *pIdx;                /* Copy of pProbe, or zero for IPK index */
  int eqTermMask;             /* Current mask of valid equality operators */
  int idxEqTermMask;          /* Index mask of valid equality operators */
  Index sPk;                  /* A fake index object for the primary key */
  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
  int wsFlagMask;             /* Allowed flags in p->cost.plan.wsFlag */






  /* Initialize the cost to a worst-case value */
  memset(&p->cost, 0, sizeof(p->cost));
  p->cost.rCost = SQLITE_BIG_DBL;

  /* If the pSrc table is the right table of a LEFT JOIN then we may not
  ** use an index to satisfy IS NULL constraints on that table.  This is
................................................................................
    pProbe = &sPk;
    wsFlagMask = ~(
        WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE
    );
    eqTermMask = WO_EQ|WO_IN;
    pIdx = 0;
  }












  /* Loop over all indices looking for the best one to use
  */
  for(; pProbe; pIdx=pProbe=pProbe->pNext){
    const tRowcnt * const aiRowEst = pProbe->aiRowEst;
    WhereCost pc;               /* Cost of using pProbe */
    double log10N = (double)1;  /* base-10 logarithm of nRow (inexact) */
................................................................................
    **             SELECT a, b    FROM tbl WHERE a = 1;
    **             SELECT a, b, c FROM tbl WHERE a = 1;
    */
    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
    int nInMul = 1;               /* Number of distinct equalities to lookup */
    double rangeDiv = (double)1;  /* Estimated reduction in search space */
    int nBound = 0;               /* Number of range constraints seen */
    int bSort;                    /* True if external sort required */
    int bDist;                    /* True if index cannot help with DISTINCT */
    int bLookup = 0;              /* True if not a covering index */
    int nPriorSat;                /* ORDER BY terms satisfied by outer loops */
    int nOrderBy;                 /* Number of ORDER BY terms */
    WhereTerm *pTerm;             /* A single term of the WHERE clause */
#ifdef SQLITE_ENABLE_STAT3
    WhereTerm *pFirstTerm = 0;    /* First term matching the index */
#endif

    WHERETRACE((
      "   %s(%s):\n",
      pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk")
    ));
    memset(&pc, 0, sizeof(pc));
    nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0;
    if( p->i ){
      nPriorSat = pc.plan.nOBSat = p->aLevel[p->i-1].plan.nOBSat;
      bSort = nPriorSat<nOrderBy;
      bDist = 0;
    }else{
      nPriorSat = pc.plan.nOBSat = 0;
      bSort = nOrderBy>0;
      bDist = p->pDistinct!=0;
    }

    /* Determine the values of pc.plan.nEq and nInMul */
    for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){
      int j = pProbe->aiColumn[pc.plan.nEq];
      pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx);
      if( pTerm==0 ) break;
      pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);
................................................................................
      /* Do nothing */
    }else
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      int iCur = pTabItem->iCursor;
      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);


    }else
#endif
    if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
      int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
      testcase( pTab->nCol==BMS-1 );

*/
#define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}

/*
** Commute a comparison operator.  Expressions of the form "X op Y"
** are converted into "Y op X".
**
** If left/right precendence rules come into play when determining the
** collating
** side of the comparison, it remains associated with the same side after
** the commutation. So "Y collate NOCASE op X" becomes 
** "X op Y". This is because any collation sequence on
** the left hand side of a comparison overrides any collation sequence 
** attached to the right. For the same reason the EP_Collate flag
** is not commuted.
*/
static void exprCommute(Parse *pParse, Expr *pExpr){
  u16 expRight = (pExpr->pRight->flags & EP_Collate);
  u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
  if( expRight==expLeft ){
    /* Either X and Y both have COLLATE operator or neither do */
    if( expRight ){
      /* Both X and Y have COLLATE operators.  Make sure X is always
      ** used by clearing the EP_Collate flag from Y. */
      pExpr->pRight->flags &= ~EP_Collate;
    }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){


      /* Neither X nor Y have COLLATE operators, but X has a non-default
      ** collating sequence.  So add the EP_Collate marker on X to cause
      ** it to be searched first. */
      pExpr->pLeft->flags |= EP_Collate;
    }
  }
  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
  if( pExpr->op>=TK_GT ){
    assert( TK_LT==TK_GT+2 );
    assert( TK_GE==TK_LE+2 );
    assert( TK_GT>TK_EQ );
    assert( TK_GT<TK_LE );
    assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
................................................................................
  
          /* Figure out the collation sequence required from an index for
          ** it to be useful for optimising expression pX. Store this
          ** value in variable pColl.
          */
          assert(pX->pLeft);
          pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
          if( pColl==0 ) pColl = pParse->db->pDfltColl;
  
          for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
            if( NEVER(j>=pIdx->nColumn) ) return 0;
          }
          if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ) continue;
        }
        return pTerm;
      }
    }
  }
  return 0;
}
................................................................................
  sqlite3 *db = pParse->db;        /* Database connection */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = pWC->pMaskSet;
  pExpr = sqlite3ExprSkipCollate(pTerm->pExpr);
  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
  op = pExpr->op;
  if( op==TK_IN ){
    assert( pExpr->pRight==0 );
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
      pTerm->prereqRight = exprSelectTableUsage(pMaskSet, pExpr->x.pSelect);
    }else{
................................................................................
                       ** on left table of a LEFT JOIN.  Ticket #3015 */
  }
  pTerm->prereqAll = prereqAll;
  pTerm->leftCursor = -1;
  pTerm->iParent = -1;
  pTerm->eOperator = 0;
  if( allowedOp(op) && (pTerm->prereqRight & prereqLeft)==0 ){
    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
    if( pLeft->op==TK_COLUMN ){
      pTerm->leftCursor = pLeft->iTable;
      pTerm->u.leftColumn = pLeft->iColumn;
      pTerm->eOperator = operatorMask(op);
    }
    if( pRight && pRight->op==TK_COLUMN ){
      WhereTerm *pNew;
................................................................................
        pTerm->nChild = 1;
        pTerm->wtFlags |= TERM_COPIED;
      }else{
        pDup = pExpr;
        pNew = pTerm;
      }
      exprCommute(pParse, pDup);
      pLeft = sqlite3ExprSkipCollate(pDup->pLeft);
      pNew->leftCursor = pLeft->iTable;
      pNew->u.leftColumn = pLeft->iColumn;
      testcase( (prereqLeft | extraRight) != prereqLeft );
      pNew->prereqRight = prereqLeft | extraRight;
      pNew->prereqAll = prereqAll;
      pNew->eOperator = operatorMask(pDup->op);
    }
................................................................................
  ){
    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
    Expr *pNewExpr1;
    Expr *pNewExpr2;
    int idxNew1;
    int idxNew2;
    Token sCollSeqName;  /* Name of collating sequence */

    pLeft = pExpr->x.pList->a[1].pExpr;
    pStr2 = sqlite3ExprDup(db, pStr1, 0);
    if( !db->mallocFailed ){
      u8 c, *pC;       /* Last character before the first wildcard */
      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
      c = *pC;
................................................................................
        if( c=='A'-1 ) isComplete = 0;   /* EV: R-64339-08207 */


        c = sqlite3UpperToLower[c];
      }
      *pC = c + 1;
    }
    sCollSeqName.z = noCase ? "NOCASE" : "BINARY";
    sCollSeqName.n = 6;
    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
    pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 

           sqlite3ExprAddCollateToken(pParse,pNewExpr1,&sCollSeqName),
           pStr1, 0);
    idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew1==0 );
    exprAnalyze(pSrc, pWC, idxNew1);
    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,

           sqlite3ExprAddCollateToken(pParse,pNewExpr2,&sCollSeqName),
           pStr2, 0);
    idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
    testcase( idxNew2==0 );
    exprAnalyze(pSrc, pWC, idxNew2);
    pTerm = &pWC->a[idxTerm];
    if( isComplete ){
      pWC->a[idxNew1].iParent = idxTerm;
      pWC->a[idxNew2].iParent = idxTerm;
................................................................................
  Index *pIdx,                    /* Index to match column of */
  int iCol                        /* Column of index to match */
){
  int i;
  const char *zColl = pIdx->azColl[iCol];

  for(i=0; i<pList->nExpr; i++){
    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
    if( p->op==TK_COLUMN
     && p->iColumn==pIdx->aiColumn[iCol]
     && p->iTable==iBase
    ){
      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
      if( ALWAYS(pColl) && 0==sqlite3StrICmp(pColl->zName, zColl) ){
        return i;
      }
    }
  }

  return -1;
................................................................................
  ** can be ignored. If it does not, and the column does not belong to the
  ** same table as index pIdx, return early. Finally, if there is no
  ** matching "col=X" expression and the column is on the same table as pIdx,
  ** set the corresponding bit in variable mask.
  */
  for(i=0; i<pDistinct->nExpr; i++){
    WhereTerm *pTerm;
    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
    if( p->op!=TK_COLUMN ) return 0;
    pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0);
    if( pTerm ){
      Expr *pX = pTerm->pExpr;
      CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
      CollSeq *p2 = sqlite3ExprCollSeq(pParse, p);
      if( p1==p2 ) continue;
................................................................................
  pTab = pTabList->a[0].pTab;

  /* If any of the expressions is an IPK column on table iBase, then return 
  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
  ** current SELECT is a correlated sub-query.
  */
  for(i=0; i<pDistinct->nExpr; i++){
    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
    if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
  }

  /* Loop through all indices on the table, checking each to see if it makes
  ** the DISTINCT qualifier redundant. It does so if:
  **
  **   1. The index is itself UNIQUE, and
................................................................................
    int isMatch;            /* ORDER BY term matches the index term */
    const char *zColl;      /* Name of collating sequence for i-th index term */
    WhereTerm *pConstraint; /* A constraint in the WHERE clause */

    /* If the next term of the ORDER BY clause refers to anything other than
    ** a column in the "base" table, then this index will not be of any
    ** further use in handling the ORDER BY. */
    pOBExpr = sqlite3ExprSkipCollate(pOBItem->pExpr);
    if( pOBExpr->op!=TK_COLUMN || pOBExpr->iTable!=base ){
      break;
    }

    /* Find column number and collating sequence for the next entry
    ** in the index */
    if( pIdx->zName && i<pIdx->nColumn ){
................................................................................
    }

    /* Check to see if the column number and collating sequence of the
    ** index match the column number and collating sequence of the ORDER BY
    ** clause entry.  Set isMatch to 1 if they both match. */
    if( pOBExpr->iColumn==iColumn ){
      if( zColl ){
        pColl = sqlite3ExprCollSeq(pParse, pOBItem->pExpr);
        if( !pColl ) pColl = db->pDfltColl;
        isMatch = sqlite3StrICmp(pColl->zName, zColl)==0;
      }else{
        isMatch = 1;
      }
    }else{
      isMatch = 0;
................................................................................
  Index *pIdx;                /* Copy of pProbe, or zero for IPK index */
  int eqTermMask;             /* Current mask of valid equality operators */
  int idxEqTermMask;          /* Index mask of valid equality operators */
  Index sPk;                  /* A fake index object for the primary key */
  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
  int wsFlagMask;             /* Allowed flags in p->cost.plan.wsFlag */
  int nPriorSat;              /* ORDER BY terms satisfied by outer loops */
  int nOrderBy;               /* Number of ORDER BY terms */
  char bSortInit;             /* Initializer for bSort in inner loop */
  char bDistInit;             /* Initializer for bDist in inner loop */


  /* Initialize the cost to a worst-case value */
  memset(&p->cost, 0, sizeof(p->cost));
  p->cost.rCost = SQLITE_BIG_DBL;

  /* If the pSrc table is the right table of a LEFT JOIN then we may not
  ** use an index to satisfy IS NULL constraints on that table.  This is
................................................................................
    pProbe = &sPk;
    wsFlagMask = ~(
        WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE
    );
    eqTermMask = WO_EQ|WO_IN;
    pIdx = 0;
  }

  nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0;
  if( p->i ){
    nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
    bSortInit = nPriorSat<nOrderBy;
    bDistInit = 0;
  }else{
    nPriorSat = 0;
    bSortInit = nOrderBy>0;
    bDistInit = p->pDistinct!=0;
  }

  /* Loop over all indices looking for the best one to use
  */
  for(; pProbe; pIdx=pProbe=pProbe->pNext){
    const tRowcnt * const aiRowEst = pProbe->aiRowEst;
    WhereCost pc;               /* Cost of using pProbe */
    double log10N = (double)1;  /* base-10 logarithm of nRow (inexact) */
................................................................................
    **             SELECT a, b    FROM tbl WHERE a = 1;
    **             SELECT a, b, c FROM tbl WHERE a = 1;
    */
    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
    int nInMul = 1;               /* Number of distinct equalities to lookup */
    double rangeDiv = (double)1;  /* Estimated reduction in search space */
    int nBound = 0;               /* Number of range constraints seen */
    char bSort = bSortInit;       /* True if external sort required */
    char bDist = bDistInit;       /* True if index cannot help with DISTINCT */
    char bLookup = 0;             /* True if not a covering index */


    WhereTerm *pTerm;             /* A single term of the WHERE clause */
#ifdef SQLITE_ENABLE_STAT3
    WhereTerm *pFirstTerm = 0;    /* First term matching the index */
#endif

    WHERETRACE((
      "   %s(%s):\n",
      pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk")
    ));
    memset(&pc, 0, sizeof(pc));






    pc.plan.nOBSat = nPriorSat;




    /* Determine the values of pc.plan.nEq and nInMul */
    for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){
      int j = pProbe->aiColumn[pc.plan.nEq];
      pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx);
      if( pTerm==0 ) break;
      pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);
................................................................................
      /* Do nothing */
    }else
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
      int iCur = pTabItem->iCursor;
      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
    }else if( IsVirtual(pTab) ){
      /* noop */
    }else
#endif
    if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
      int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
      testcase( pTab->nCol==BMS-1 );

# Test that if the source is zero bytes, the destination database 
# consists of a single page only.
#
do_execsql_test 2.1 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a, b);
}

do_test 2.2 { file size test.db } 3072

do_test 2.3 {
  sqlite3 db1 test.db2
  db1 backup test.db
  db1 close
  file size test.db
} {1024}
................................................................................
# of a single page.
#
do_execsql_test 3.1 {
  PRAGMA page_size = 4096;
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a, b);
}

do_test 3.2 { file size test.db } 12288

do_test 3.3 {
  sqlite3 db1 test.db2
  db1 backup test.db
  db1 close
  file size test.db
} {1024}

do_test 3.4 { file size test.db2 } 0

finish_test

# Test that if the source is zero bytes, the destination database 
# consists of a single page only.
#
do_execsql_test 2.1 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a, b);
}

do_test 2.2 { file size test.db } [expr $AUTOVACUUM ? 4096 : 3072]

do_test 2.3 {
  sqlite3 db1 test.db2
  db1 backup test.db
  db1 close
  file size test.db
} {1024}
................................................................................
# of a single page.
#
do_execsql_test 3.1 {
  PRAGMA page_size = 4096;
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a, b);
}

do_test 3.2 { file size test.db } [expr $AUTOVACUUM ? 16384 : 12288]

do_test 3.3 {
  sqlite3 db1 test.db2
  db1 backup test.db
  db1 close
  file size test.db
} {1024}

do_test 3.4 { file size test.db2 } 0

finish_test

} {}
do_test collate1-1.1 {
  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1;
  }
} {{} 0x119 0x2D}
do_test collate1-1.2 {

  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1 COLLATE hex;
  }
} {{} 0x2D 0x119}
do_test collate1-1.3 {
  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1 COLLATE hex DESC;

} {}
do_test collate1-1.1 {
  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1;
  }
} {{} 0x119 0x2D}
do_test collate1-1.2 {
breakpoint
  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1 COLLATE hex;
  }
} {{} 0x2D 0x119}
do_test collate1-1.3 {
  execsql {
    SELECT c2 FROM collate1t1 ORDER BY 1 COLLATE hex DESC;

  2   "b, a FROM t1"                                       {}      {B A b a}
  3   "a, b, c FROM t1"                                    {hash}  {a b c A B C}
  4   "a, b, c FROM t1 ORDER BY a, b, c"                   {btree} {A B C a b c}
  5   "b FROM t1 WHERE a = 'a'"                            {}      {b}
  6   "b FROM t1"                                          {hash}  {b B}
  7   "a FROM t1"                                          {}      {A a}
  8   "b COLLATE nocase FROM t1"                           {}      {b}
  9   "b COLLATE nocase FROM t1 ORDER BY b COLLATE nocase" {}      {B}
} {
  do_execsql_test    2.$tn.1 "SELECT DISTINCT $sql" $res
  do_temptables_test 2.$tn.2 "SELECT DISTINCT $sql" $temptables
}

do_execsql_test 2.A {
  SELECT (SELECT DISTINCT o.a FROM t1 AS i) FROM t1 AS o ORDER BY rowid;

  2   "b, a FROM t1"                                       {}      {B A b a}
  3   "a, b, c FROM t1"                                    {hash}  {a b c A B C}
  4   "a, b, c FROM t1 ORDER BY a, b, c"                   {btree} {A B C a b c}
  5   "b FROM t1 WHERE a = 'a'"                            {}      {b}
  6   "b FROM t1"                                          {hash}  {b B}
  7   "a FROM t1"                                          {}      {A a}
  8   "b COLLATE nocase FROM t1"                           {}      {b}
  9   "b COLLATE nocase FROM t1 ORDER BY b COLLATE nocase" {}      {b}
} {
  do_execsql_test    2.$tn.1 "SELECT DISTINCT $sql" $res
  do_temptables_test 2.$tn.2 "SELECT DISTINCT $sql" $temptables
}

do_execsql_test 2.A {
  SELECT (SELECT DISTINCT o.a FROM t1 AS i) FROM t1 AS o ORDER BY rowid;

  file_control_lasterrno_test db
} {}
do_test filectrl-1.5 {
  db close
  sqlite3 db test_control_lockproxy.db
  file_control_lockproxy_test db [get_pwd]
} {}






db close
forcedelete .test_control_lockproxy.db-conch test.proxy
finish_test

  file_control_lasterrno_test db
} {}
do_test filectrl-1.5 {
  db close
  sqlite3 db test_control_lockproxy.db
  file_control_lockproxy_test db [get_pwd]
} {}
do_test filectrl-1.6 {
  sqlite3 db test.db
  set fn [file_control_tempfilename db]
  puts -nonewline \[$fn\]
  set fn
} {/etilqs_/}
db close
forcedelete .test_control_lockproxy.db-conch test.proxy
finish_test

for {set i 1} {$i<$max_count-5} {incr i 1} {
  do_test interrupt-4.$i.1 {
    set ::sqlite_interrupt_count $::i
    catchsql $sql
  } {1 interrupted}
}



# Interrupt during parsing
#
do_test interrupt-5.1 {
  proc fake_interrupt {args} {
    db collate fake_collation no-op
    sqlite3_interrupt db
    return SQLITE_OK
  }
  db collation_needed fake_interrupt
  catchsql {
    CREATE INDEX fake ON fake1(a COLLATE fake_collation, b, c DESC);
  }
} {1 interrupt}

finish_test

for {set i 1} {$i<$max_count-5} {incr i 1} {
  do_test interrupt-4.$i.1 {
    set ::sqlite_interrupt_count $::i
    catchsql $sql
  } {1 interrupted}
}

if {0} {  # This doesn't work anymore since the collation factor is
          # no longer called during schema parsing.
# Interrupt during parsing
#
do_test interrupt-5.1 {
  proc fake_interrupt {args} {
    db collate fake_collation no-op
    sqlite3_interrupt db
    return SQLITE_OK
  }
  db collation_needed fake_interrupt
  catchsql {
    CREATE INDEX fake ON fake1(a COLLATE fake_collation, b, c DESC);
  }
} {1 interrupt}
}
finish_test

#
if {!$MEMDEBUG} {
   puts "Skipping malloc3 tests: not compiled with -DSQLITE_MEMDEBUG..."
   finish_test
   return
}



















#--------------------------------------------------------------------------
# NOTES ON RECOVERING FROM A MALLOC FAILURE
# 
# The tests in this file test the behaviours described in the following
# paragraphs. These tests test the behaviour of the system when malloc() fails
# inside of a call to _prepare(), _step(), _finalize() or _reset(). The
# handling of malloc() failures within ancillary procedures is tested
................................................................................
#--------------------------------------------------------------------------


# These procs are used to build up a "program" in global variable
# ::run_test_script. At the end of this file, the proc [run_test] is used
# to execute the program (and all test cases contained therein).
#

set ::run_test_script [list]
proc TEST {id t} {lappend ::run_test_script -test [list $id $t]}
proc PREP {p} {lappend ::run_test_script -prep [string trim $p]}
proc DEBUG {s} {lappend ::run_test_script -debug $s}

# SQL --
#
................................................................................
#
# Add an 'SQL' primitive to the program (see notes above). If the -norollback
# switch is present, then the statement is not allowed to automatically roll
# back any active transaction if malloc() fails. It must rollback the statement
# transaction only.
#
proc SQL  {a1 {a2 ""}} {
  # An SQL primitive parameter is a list of two elements, a boolean value
  # indicating if the statement may cause transaction rollback when malloc()
  # fails, and the sql statement itself.

  if {$a2 == ""} {
    lappend ::run_test_script -sql [list true [string trim $a1]]
  } else {
    lappend ::run_test_script -sql [list false [string trim $a2]]
  }
}

# TEST_AUTOCOMMIT --
# 
#     A shorthand test to see if a transaction is active or not. The first
#     argument - $id - is the integer number of the test case. The second
................................................................................
    }
  } {abc abc abc_i abc abc_t abc abc_v abc_v 1 2 3}
}

set sql {
  BEGIN;DELETE FROM abc;
}
for {set i 1} {$i < 15} {incr i} {
  set a $i
  set b "String value $i"
  set c [string repeat X $i]
  append sql "INSERT INTO abc VALUES ($a, '$b', '$c');"
}
append sql {COMMIT;}
PREP $sql
................................................................................

proc run_test {arglist iRepeat {pcstart 0} {iFailStart 1}} {
  if {[llength $arglist] %2} {
    error "Uneven number of arguments to TEST"
  }

  for {set i 0} {$i < $pcstart} {incr i} {
    set k2 [lindex $arglist [expr 2 * $i]]
    set v2 [lindex $arglist [expr 2 * $i + 1]]
    set ac [sqlite3_get_autocommit $::DB]        ;# Auto-Commit
    switch -- $k2 {
      -sql  {db eval [lindex $v2 1]}
      -prep {db eval $v2}

    }
    set nac [sqlite3_get_autocommit $::DB]       ;# New Auto-Commit 
    if {$ac && !$nac} {set begin_pc $i}
  }

  db rollback_hook [list incr ::rollback_hook_count]

  set iFail $iFailStart
  set pc $pcstart
  while {$pc*2 < [llength $arglist]} {




    # Id of this iteration:
    set k [lindex $arglist [expr 2 * $pc]]
    set iterid "pc=$pc.iFail=$iFail$k"
    set v [lindex $arglist [expr 2 * $pc + 1]]

    switch -- $k {

      -test { 
        foreach {id script} $v {}


        incr pc
      }

      -sql {
        set ::rollback_hook_count 0




        set ac [sqlite3_get_autocommit $::DB]        ;# Auto-Commit
        sqlite3_memdebug_fail $iFail -repeat 0
        set rc [catch {db eval [lindex $v 1]} msg]   ;# True error occurs
        set nac [sqlite3_get_autocommit $::DB]       ;# New Auto-Commit 

        if {$rc != 0 && $nac && !$ac} {
          # Before [db eval] the auto-commit flag was clear. Now it
          # is set. Since an error occured we assume this was not a
          # commit - therefore a rollback occured. Check that the
          # rollback-hook was invoked.
          do_test malloc3-rollback_hook.$iterid {
            set ::rollback_hook_count
          } {1}
        }

        set nFail [sqlite3_memdebug_fail -1 -benigncnt nBenign]
        if {$rc == 0} {
            # Successful execution of sql. The number of failed malloc()
            # calls should be equal to the number of benign failures.
            # Otherwise a malloc() failed and the error was not reported.
            # 
            if {$nFail!=$nBenign} {

              error "Unreported malloc() failure"
            }

            if {$ac && !$nac} {
              # Before the [db eval] the auto-commit flag was set, now it
              # is clear. We can deduce that a "BEGIN" statement has just
              # been successfully executed.
              set begin_pc $pc
            } 

            incr pc
            set iFail 1
            integrity_check "malloc3-(integrity).$iterid"
        } elseif {[regexp {.*out of memory} $msg] || [db errorcode] == 3082} {
            # Out of memory error, as expected.
            #
            integrity_check "malloc3-(integrity).$iterid"
            incr iFail
            if {$nac && !$ac} {

              if {![lindex $v 0] && [db errorcode] != 3082} {
                # error "Statement \"[lindex $v 1]\" caused a rollback"
              }

              for {set i $begin_pc} {$i < $pc} {incr i} {
                set k2 [lindex $arglist [expr 2 * $i]]
                set v2 [lindex $arglist [expr 2 * $i + 1]]
                set catchupsql ""
                switch -- $k2 {
                  -sql  {set catchupsql [lindex $v2 1]}
                  -prep {set catchupsql $v2}
                }
                db eval $catchupsql
              }
            }
        } else {
            error $msg
        }


        while {[lindex $arglist [expr 2 * ($pc -1)]] == "-test"} {
          incr pc -1
        }
      }

      -prep {
        db eval $v
        incr pc
................................................................................
      }

      default { error "Unknown switch: $k" }
    }
  }
}

# Turn of the Tcl interface's prepared statement caching facility. Then
# run the tests with "persistent" malloc failures.
sqlite3_extended_result_codes db 1
db cache size 0
run_test $::run_test_script 1

# Close and reopen the db.
db close

#
if {!$MEMDEBUG} {
   puts "Skipping malloc3 tests: not compiled with -DSQLITE_MEMDEBUG..."
   finish_test
   return
}


# Do not run these tests with an in-memory journal.
#
# In the pager layer, if an IO or OOM error occurs during a ROLLBACK, or
# when flushing a page to disk due to cache-stress, the pager enters an
# "error state". The only way out of the error state is to unlock the
# database file and end the transaction, leaving whatever journal and
# database files happen to be on disk in place. The next time the current
# (or any other) connection opens a read transaction, hot-journal rollback
# is performed if necessary.
#
# Of course, this doesn't work with an in-memory journal.
#
if {[permutation]=="inmemory_journal"} {
  finish_test
  return
}

#--------------------------------------------------------------------------
# NOTES ON RECOVERING FROM A MALLOC FAILURE
# 
# The tests in this file test the behaviours described in the following
# paragraphs. These tests test the behaviour of the system when malloc() fails
# inside of a call to _prepare(), _step(), _finalize() or _reset(). The
# handling of malloc() failures within ancillary procedures is tested
................................................................................
#--------------------------------------------------------------------------


# These procs are used to build up a "program" in global variable
# ::run_test_script. At the end of this file, the proc [run_test] is used
# to execute the program (and all test cases contained therein).
#
set ::run_test_sql_id 0
set ::run_test_script [list]
proc TEST {id t} {lappend ::run_test_script -test [list $id $t]}
proc PREP {p} {lappend ::run_test_script -prep [string trim $p]}
proc DEBUG {s} {lappend ::run_test_script -debug $s}

# SQL --
#
................................................................................
#
# Add an 'SQL' primitive to the program (see notes above). If the -norollback
# switch is present, then the statement is not allowed to automatically roll
# back any active transaction if malloc() fails. It must rollback the statement
# transaction only.
#
proc SQL  {a1 {a2 ""}} {
  # An SQL primitive parameter is a list of three elements, an id, a boolean
  # value indicating if the statement may cause transaction rollback when
  # malloc() fails, and the sql statement itself.
  set id [incr ::run_test_sql_id]
  if {$a2 == ""} {
    lappend ::run_test_script -sql [list $id true [string trim $a1]]
  } else {
    lappend ::run_test_script -sql [list $id false [string trim $a2]]
  }
}

# TEST_AUTOCOMMIT --
# 
#     A shorthand test to see if a transaction is active or not. The first
#     argument - $id - is the integer number of the test case. The second
................................................................................
    }
  } {abc abc abc_i abc abc_t abc abc_v abc_v 1 2 3}
}

set sql {
  BEGIN;DELETE FROM abc;
}
for {set i 1} {$i < 100} {incr i} {
  set a $i
  set b "String value $i"
  set c [string repeat X $i]
  append sql "INSERT INTO abc VALUES ($a, '$b', '$c');"
}
append sql {COMMIT;}
PREP $sql
................................................................................

proc run_test {arglist iRepeat {pcstart 0} {iFailStart 1}} {
  if {[llength $arglist] %2} {
    error "Uneven number of arguments to TEST"
  }

  for {set i 0} {$i < $pcstart} {incr i} {
    set k2 [lindex $arglist [expr {2 * $i}]]
    set v2 [lindex $arglist [expr {2 * $i + 1}]]
    set ac [sqlite3_get_autocommit $::DB]        ;# Auto-Commit
    switch -- $k2 {
      -sql  {db eval [lindex $v2 2]}
      -prep {db eval $v2}
      -debug {eval $v2}
    }
    set nac [sqlite3_get_autocommit $::DB]       ;# New Auto-Commit 
    if {$ac && !$nac} {set begin_pc $i}
  }

  db rollback_hook [list incr ::rollback_hook_count]

  set iFail $iFailStart
  set pc $pcstart
  while {$pc*2 < [llength $arglist]} {
    # Fetch the current instruction type and payload.
    set k [lindex $arglist [expr {2 * $pc}]]
    set v [lindex $arglist [expr {2 * $pc + 1}]]

    # Id of this iteration:

    set iterid "pc=$pc.iFail=$iFail$k"


    switch -- $k {

      -test { 
        foreach {id script} $v {}
        set testid "malloc3-(test $id).$iterid"
        eval $script
        incr pc
      }

      -sql {
        set ::rollback_hook_count 0

        set id [lindex $v 0]
        set testid "malloc3-(integrity $id).$iterid"

        set ac [sqlite3_get_autocommit $::DB]        ;# Auto-Commit
        sqlite3_memdebug_fail $iFail -repeat 0
        set rc [catch {db eval [lindex $v 2]} msg]   ;# True error occurs
        set nac [sqlite3_get_autocommit $::DB]       ;# New Auto-Commit 

        if {$rc != 0 && $nac && !$ac} {
          # Before [db eval] the auto-commit flag was clear. Now it
          # is set. Since an error occured we assume this was not a
          # commit - therefore a rollback occured. Check that the
          # rollback-hook was invoked.
          do_test malloc3-rollback_hook_count.$iterid {
            set ::rollback_hook_count
          } {1}
        }

        set nFail [sqlite3_memdebug_fail -1 -benigncnt nBenign]
        if {$rc == 0} {
            # Successful execution of sql. The number of failed malloc()
            # calls should be equal to the number of benign failures.
            # Otherwise a malloc() failed and the error was not reported.
            # 
            set expr {$nFail!=$nBenign}
            if {[expr $expr]} {
              error "Unreported malloc() failure, test \"$testid\", $expr"
            }

            if {$ac && !$nac} {
              # Before the [db eval] the auto-commit flag was set, now it
              # is clear. We can deduce that a "BEGIN" statement has just
              # been successfully executed.
              set begin_pc $pc
            } 

            incr pc
            set iFail 1
            integrity_check $testid
        } elseif {[regexp {.*out of memory} $msg] || [db errorcode] == 3082} {
            # Out of memory error, as expected.
            #
            integrity_check $testid
            incr iFail
            if {$nac && !$ac} {

              if {![lindex $v 1] && [db errorcode] != 3082} {
                # error "Statement \"[lindex $v 2]\" caused a rollback"
              }

              for {set i $begin_pc} {$i < $pc} {incr i} {
                set k2 [lindex $arglist [expr {2 * $i}]]
                set v2 [lindex $arglist [expr {2 * $i + 1}]]
                set catchupsql ""
                switch -- $k2 {
                  -sql  {set catchupsql [lindex $v2 2]}
                  -prep {set catchupsql $v2}
                }
                db eval $catchupsql
              }
            }
        } else {
            error $msg
        }

        # back up to the previous "-test" block.
        while {[lindex $arglist [expr {2 * ($pc - 1)}]] == "-test"} {
          incr pc -1
        }
      }

      -prep {
        db eval $v
        incr pc
................................................................................
      }

      default { error "Unknown switch: $k" }
    }
  }
}

# Turn off the Tcl interface's prepared statement caching facility. Then
# run the tests with "persistent" malloc failures.
sqlite3_extended_result_codes db 1
db cache size 0
run_test $::run_test_script 1

# Close and reopen the db.
db close

  set ::invoked_mycollate_db1 0
  db2 eval {
    INSERT INTO t1 VALUES('two');
  }
  db2 close
  set ::invoked_mycollate_db1
} {0}

























#-------------------------------------------------------------------------
# This test verifies that a bug causing a busy-handler belonging to one
# shared-cache connection to be executed as a result of an sqlite3_step()
# on another has been fixed.
#
forcedelete test.db test.db2
................................................................................
} {}
  
db1 close
db2 close

sqlite3_enable_shared_cache $::enable_shared_cache
finish_test

  set ::invoked_mycollate_db1 0
  db2 eval {
    INSERT INTO t1 VALUES('two');
  }
  db2 close
  set ::invoked_mycollate_db1
} {0}

forcedelete test.db test.db2
sqlite3 db1 test.db
sqlite3 db2 test.db
db1 collate mycollate mycollate_db1
db2 collate mycollate mycollate_db2

do_test 2.13 {
  set ::invoked_mycollate_db1 0
  db1 eval {
    CREATE TABLE t1(a, CHECK (a COLLATE mycollate IN ('one', 'two', 'three')));
    INSERT INTO t1 VALUES('one');
  }
  db1 close
  set ::invoked_mycollate_db1
} {1}
do_test 2.14 {
  set ::invoked_mycollate_db1 0
  db2 eval {
    INSERT INTO t1 VALUES('two');
  }
  db2 close
  set ::invoked_mycollate_db1
} {0}

#-------------------------------------------------------------------------
# This test verifies that a bug causing a busy-handler belonging to one
# shared-cache connection to be executed as a result of an sqlite3_step()
# on another has been fixed.
#
forcedelete test.db test.db2
................................................................................
} {}
  
db1 close
db2 close

sqlite3_enable_shared_cache $::enable_shared_cache
finish_test

  } db2
  for {set i 0} {$i < 2} {incr i} {
    set a [string repeat $i 10]
    set b [string repeat $i 2000]
    execsql {INSERT INTO t1 VALUES($a, $b)} db2
  }
  execsql {COMMIT} db2


  set ::DB2 [sqlite3_connection_pointer db2]
  set ::STMT [sqlite3_prepare $::DB2 "SELECT a FROM t1 ORDER BY a" -1 DUMMY]
  sqlite3_step $::STMT       ;# Cursor points at 0000000000
  sqlite3_step $::STMT       ;# Cursor points at 1111111111
} -tclbody {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(6, NULL);
    ROLLBACK;
  }
} -cleanup {
  # UPDATE: As of [5668], if the rollback fails SQLITE_CORRUPT is returned. 
  # So these tests have been updated to expect SQLITE_CORRUPT and its
  # associated English language error message.
  #
  do_test shared_malloc-8.$::n.cleanup.1 {
    set res [catchsql {SELECT a FROM t1} db2]

  } db2
  for {set i 0} {$i < 2} {incr i} {
    set a [string repeat $i 10]
    set b [string repeat $i 2000]
    execsql {INSERT INTO t1 VALUES($a, $b)} db2
  }
  execsql {COMMIT} db2
  execsql BEGIN
  execsql ROLLBACK
  set ::DB2 [sqlite3_connection_pointer db2]
  set ::STMT [sqlite3_prepare $::DB2 "SELECT a FROM t1 ORDER BY a" -1 DUMMY]
  sqlite3_step $::STMT       ;# Cursor points at 0000000000
  sqlite3_step $::STMT       ;# Cursor points at 1111111111
} -tclbody {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(6, NULL);
    ROLLBACK}

} -cleanup {
  # UPDATE: As of [5668], if the rollback fails SQLITE_CORRUPT is returned. 
  # So these tests have been updated to expect SQLITE_CORRUPT and its
  # associated English language error message.
  #
  do_test shared_malloc-8.$::n.cleanup.1 {
    set res [catchsql {SELECT a FROM t1} db2]

} {0 {this is a test}}

# Test the output of the ".dump" command
#
do_test shell1-4.1 {
  db eval {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(null), (1), (2.25), ('hello'), (x'807f');
  }
  catchcmd test.db {.dump}
} {0 {PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE t1(x);
INSERT INTO "t1" VALUES(NULL);

INSERT INTO "t1" VALUES(1);
INSERT INTO "t1" VALUES(2.25);
INSERT INTO "t1" VALUES('hello');
INSERT INTO "t1" VALUES(X'807F');
COMMIT;}}

# Test the output of ".mode insert"
#
do_test shell1-4.2 {
  catchcmd test.db ".mode insert t1\nselect * from t1;"
} {0 {INSERT INTO t1 VALUES(NULL);

INSERT INTO t1 VALUES(1);
INSERT INTO t1 VALUES(2.25);
INSERT INTO t1 VALUES('hello');
INSERT INTO t1 VALUES(X'807f');}}

















































finish_test

} {0 {this is a test}}

# Test the output of the ".dump" command
#
do_test shell1-4.1 {
  db eval {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(null), (''), (1), (2.25), ('hello'), (x'807f');
  }
  catchcmd test.db {.dump}
} {0 {PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE t1(x);
INSERT INTO "t1" VALUES(NULL);
INSERT INTO "t1" VALUES('');
INSERT INTO "t1" VALUES(1);
INSERT INTO "t1" VALUES(2.25);
INSERT INTO "t1" VALUES('hello');
INSERT INTO "t1" VALUES(X'807F');
COMMIT;}}

# Test the output of ".mode insert"
#
do_test shell1-4.2 {
  catchcmd test.db ".mode insert t1\nselect * from t1;"
} {0 {INSERT INTO t1 VALUES(NULL);
INSERT INTO t1 VALUES('');
INSERT INTO t1 VALUES(1);
INSERT INTO t1 VALUES(2.25);
INSERT INTO t1 VALUES('hello');
INSERT INTO t1 VALUES(X'807f');}}

# Test the output of ".mode tcl"
#
do_test shell1-4.3 {
  catchcmd test.db ".mode tcl\nselect * from t1;"
} {0 {""
""
"1"
"2.25"
"hello"
"\200\177"}}

# Test the output of ".mode tcl" with multiple columns
#
do_test shell1-4.4 {
  db eval {
    CREATE TABLE t2(x,y);
    INSERT INTO t2 VALUES(null, ''), (1, 2.25), ('hello', x'807f');
  }
  catchcmd test.db ".mode tcl\nselect * from t2;"
} {0 {"" ""
"1" "2.25"
"hello" "\200\177"}}

# Test the output of ".mode tcl" with ".nullvalue"
#
do_test shell1-4.5 {
  catchcmd test.db ".mode tcl\n.nullvalue NULL\nselect * from t2;"
} {0 {"NULL" ""
"1" "2.25"
"hello" "\200\177"}}

# Test the output of ".mode tcl" with Tcl reserved characters
#
do_test shell1-4.6 {
  db eval {
    CREATE TABLE tcl1(x);
    INSERT INTO tcl1 VALUES('"'), ('['), (']'), ('\{'), ('\}'), (';'), ('$');
  }
  foreach {x y} [catchcmd test.db ".mode tcl\nselect * from tcl1;"] break
  list $x $y [llength $y]
} {0 {"\""
"["
"]"
"\\{"
"\\}"
";"
"$"} 7}

finish_test

# This file implements regression tests for SQLite library.  The
# focus of this script is testing correlated subqueries
#
#

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


ifcapable !subquery {
  finish_test
  return
}

do_test subquery2-1.1 {
................................................................................
do_test subquery2-1.22 {
  execsql {
    SELECT a FROM t1
     WHERE b=(SELECT x+1 FROM 
                 (SELECT DISTINCT f/d AS x FROM t2 JOIN t3 ON d*a=f))
  }
} {1 3 5 7}






















finish_test

# This file implements regression tests for SQLite library.  The
# focus of this script is testing correlated subqueries
#
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix subquery2

ifcapable !subquery {
  finish_test
  return
}

do_test subquery2-1.1 {
................................................................................
do_test subquery2-1.22 {
  execsql {
    SELECT a FROM t1
     WHERE b=(SELECT x+1 FROM 
                 (SELECT DISTINCT f/d AS x FROM t2 JOIN t3 ON d*a=f))
  }
} {1 3 5 7}

#-------------------------------------------------------------------------
# Test that ticket d6b36be38a has been fixed.
do_execsql_test 2.1 {
  CREATE TABLE t4(a, b);
  CREATE TABLE t5(a, b);
  INSERT INTO t5 VALUES(3, 5);

  INSERT INTO t4 VALUES(1, 1);
  INSERT INTO t4 VALUES(2, 3);
  INSERT INTO t4 VALUES(3, 6);
  INSERT INTO t4 VALUES(4, 10);
  INSERT INTO t4 VALUES(5, 15);
}

do_execsql_test 2.2 {
  SELECT * 
  FROM (SELECT * FROM t4 ORDER BY a LIMIT -1 OFFSET 1) 
  LIMIT (SELECT a FROM t5)
} {2 3   3 6   4 10}


finish_test

    }
  
    for {set i 0} {$i < 100} {incr i} {
      # Test that the invariant is true.
      do_test t1 {
        execsql {
          SELECT 
            (SELECT md5sum(a, b) FROM ab WHERE a < (SELECT max(a) FROM ab)) ==
            (SELECT b FROM ab WHERE a = (SELECT max(a) FROM ab))
        }
      } {1}
  
      # Add another row to the database.
      execsql { INSERT INTO ab SELECT NULL, md5sum(a, b) FROM ab }
    }
................................................................................
  #
  do_test thread001.$tn.5 {
    execsql { SELECT count(*) FROM ab; }
  } [expr {1 + $::NTHREAD*100}]
  do_test thread001.$tn.6 {
    execsql {
      SELECT 
        (SELECT md5sum(a, b) FROM ab WHERE a < (SELECT max(a) FROM ab)) ==
        (SELECT b FROM ab WHERE a = (SELECT max(a) FROM ab))
    }
  } {1}
  do_test thread001.$tn.7 {
    execsql { PRAGMA integrity_check }
  } {ok}
}

sqlite3_enable_shared_cache $::enable_shared_cache
set sqlite_open_file_count 0
finish_test

    }
  
    for {set i 0} {$i < 100} {incr i} {
      # Test that the invariant is true.
      do_test t1 {
        execsql {
          SELECT 
            (SELECT md5sum(a, b) FROM ab WHERE +a < (SELECT max(a) FROM ab)) ==
            (SELECT b FROM ab WHERE a = (SELECT max(a) FROM ab))
        }
      } {1}
  
      # Add another row to the database.
      execsql { INSERT INTO ab SELECT NULL, md5sum(a, b) FROM ab }
    }
................................................................................
  #
  do_test thread001.$tn.5 {
    execsql { SELECT count(*) FROM ab; }
  } [expr {1 + $::NTHREAD*100}]
  do_test thread001.$tn.6 {
    execsql {
      SELECT 
        (SELECT md5sum(a, b) FROM ab WHERE +a < (SELECT max(a) FROM ab)) ==
        (SELECT b FROM ab WHERE a = (SELECT max(a) FROM ab))
    }
  } {1}
  do_test thread001.$tn.7 {
    execsql { PRAGMA integrity_check }
  } {ok}
}

sqlite3_enable_shared_cache $::enable_shared_cache
set sqlite_open_file_count 0
finish_test

    CREATE TABLE t7(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,
                    a15,a16,a17,a18,a19,a20,a21,a22,a23,a24,a25);
  }
  catchsql {
    SELECT * FROM t7 ORDER BY 0;
  }
} {1 {1st ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.2 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 0;










  }
} {1 {2nd ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.3 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 2, 0;
  }
} {1 {3rd ORDER BY term out of range - should be between 1 and 25}}

    CREATE TABLE t7(a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,
                    a15,a16,a17,a18,a19,a20,a21,a22,a23,a24,a25);
  }
  catchsql {
    SELECT * FROM t7 ORDER BY 0;
  }
} {1 {1st ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.2.1 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 0;
  }
} {1 {2nd ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.2.2 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 26;
  }
} {1 {2nd ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.2.3 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 65536;
  }
} {1 {2nd ORDER BY term out of range - should be between 1 and 25}}
do_test tkt2822-7.3 {
  catchsql {
    SELECT * FROM t7 ORDER BY 1, 2, 0;
  }
} {1 {3rd ORDER BY term out of range - should be between 1 and 25}}

    UPDATE t12 SET a=new.a+1, b=new.b+1;
  END;
} {}
do_catchsql_test triggerC-13.2 {
  UPDATE t12 SET a=a+1, b=b+1;
} {1 {too many levels of trigger recursion}}













































finish_test

    UPDATE t12 SET a=new.a+1, b=new.b+1;
  END;
} {}
do_catchsql_test triggerC-13.2 {
  UPDATE t12 SET a=a+1, b=b+1;
} {1 {too many levels of trigger recursion}}

#-------------------------------------------------------------------------
# The following tests seek to verify that constant values (i.e. literals)
# are not factored out of loops within trigger programs. SQLite does
# not factor constants out of loops within trigger programs as it may only
# do so in code generated before the first table or index is opened. And
# by the time a trigger program is coded, at least one table or index has
# always been opened.
#
# At one point, due to a bug allowing constant factoring within triggers,
# the following SQL would produce the wrong result.
#
set SQL {
  CREATE TABLE t1(a, b, c);
  CREATE INDEX i1 ON t1(a, c);
  CREATE INDEX i2 ON t1(b, c);
  INSERT INTO t1 VALUES(1, 2, 3);

  CREATE TABLE t2(e, f);
  CREATE INDEX i3 ON t2(e);
  INSERT INTO t2 VALUES(1234567, 3);

  CREATE TABLE empty(x);
  CREATE TABLE not_empty(x);
  INSERT INTO not_empty VALUES(2);

  CREATE TABLE t4(x);
  CREATE TABLE t5(g, h, i);

  CREATE TRIGGER trig BEFORE INSERT ON t4 BEGIN
    INSERT INTO t5 SELECT * FROM t1 WHERE 
        (a IN (SELECT x FROM empty) OR b IN (SELECT x FROM not_empty)) 
        AND c IN (SELECT f FROM t2 WHERE e=1234567);
  END;

  INSERT INTO t4 VALUES(0);
  SELECT * FROM t5;
}

reset_db
do_execsql_test triggerC-14.1 $SQL {1 2 3}
reset_db
optimization_control db factor-constants 0
do_execsql_test triggerC-14.2 $SQL {1 2 3}

finish_test

} SQLITE_OK
do_test 19.2 {
  register_echo_module [sqlite3_connection_pointer db2]
} SQLITE_MISUSE
do_test 19.3 {
  db2 close
} {}









































finish_test

} SQLITE_OK
do_test 19.2 {
  register_echo_module [sqlite3_connection_pointer db2]
} SQLITE_MISUSE
do_test 19.3 {
  db2 close
} {}

#-------------------------------------------------------------------------
# Test that the bug fixed by [b0c1ba655d69] really is fixed.
#
do_execsql_test 20.1 {
  CREATE TABLE t7 (a, b);
  CREATE TABLE t8 (c, d);
  CREATE INDEX i2 ON t7(a);
  CREATE INDEX i3 ON t7(b);
  CREATE INDEX i4 ON t8(c);
  CREATE INDEX i5 ON t8(d);

  CREATE VIRTUAL TABLE t7v USING echo(t7);
  CREATE VIRTUAL TABLE t8v USING echo(t8);
}

do_test 20.2 {
  for {set i 0} {$i < 1000} {incr i} {
    db eval {INSERT INTO t7 VALUES($i, $i)}
    db eval {INSERT INTO t8 VALUES($i, $i)}
  }
} {}

do_execsql_test 20.3 {
  SELECT a, b FROM (
      SELECT a, b FROM t7 WHERE a=11 OR b=12
      UNION ALL
      SELECT c, d FROM t8 WHERE c=5 OR d=6
  )
  ORDER BY 1, 2;
} {5 5 6 6 11 11 12 12}

do_execsql_test 20.4 {
  SELECT a, b FROM (
      SELECT a, b FROM t7v WHERE a=11 OR b=12
      UNION ALL
      SELECT c, d FROM t8v WHERE c=5 OR d=6
  )
  ORDER BY 1, 2;
} {5 5 6 6 11 11 12 12}

finish_test

    INSERT INTO t SELECT randomblob(100) FROM t;
    INSERT INTO t SELECT randomblob(100) FROM t;
  COMMIT;
} {}

# Check file sizes are as expected. The real requirement here is that 
# the *shm file is now more than one chunk (>32KiB).



do_test 1.3 { file size test.db     } {1024}
do_test 1.4 { file size test.db-wal } {15421352}
do_test 1.5 { expr {[file size test.db-shm]>32768} } {1}


do_execsql_test 1.6 { PRAGMA wal_checkpoint } {0 14715 14715}



# At this point connection [db2] has mapped the first 32KB of the *shm file
# only. Because the entire WAL file has been checkpointed, it is not 
# necessary to map any more of the *-shm file to read or write the database
# (since all data will be read directly from the db file). 
#
# However, at one point if a transaction that had not yet written to the 

    INSERT INTO t SELECT randomblob(100) FROM t;
    INSERT INTO t SELECT randomblob(100) FROM t;
  COMMIT;
} {}

# Check file sizes are as expected. The real requirement here is that 
# the *shm file is now more than one chunk (>32KiB).
#
# The sizes of various files are slightly different in normal and 
# auto-vacuum mode.
do_test 1.3 { file size test.db     } {1024}
do_test 1.4 { expr {[file size test.db-wal]>(1500*1024)} } {1}
do_test 1.5 { expr {[file size test.db-shm]>32768} }       {1}

do_test 1.6 { 
  foreach {a b c} [db eval {PRAGMA wal_checkpoint}] break
  list [expr {$a==0}] [expr {$b>14500}] [expr {$c>14500}] [expr {$b==$c}]
} {1 1 1 1}

# At this point connection [db2] has mapped the first 32KB of the *shm file
# only. Because the entire WAL file has been checkpointed, it is not 
# necessary to map any more of the *-shm file to read or write the database
# (since all data will be read directly from the db file). 
#
# However, at one point if a transaction that had not yet written to the 

} {1 one 4 four nosort}

# Ticket #2211.
#
# When optimizing out ORDER BY clauses, make sure that trailing terms
# of the ORDER BY clause do not reference other tables in a join.
#

do_test where-14.1 {
  execsql {
    CREATE TABLE t8(a INTEGER PRIMARY KEY, b TEXT UNIQUE);
    INSERT INTO t8 VALUES(1,'one');
    INSERT INTO t8 VALUES(4,'four');
  }
  cksort {
................................................................................
  } 
} {4/1 4/4 1/1 1/4 sort}
do_test where-14.12 {
  cksort {
    SELECT x.a || '/' || y.a FROM t8 x, t8 y ORDER BY x.b, y.a||x.b DESC
  } 
} {4/4 4/1 1/4 1/1 sort}


# Ticket #2445.
#
# There was a crash that could occur when a where clause contains an
# alias for an expression in the result set, and that expression retrieves
# a column of the second or subsequent table in a join.
#

} {1 one 4 four nosort}

# Ticket #2211.
#
# When optimizing out ORDER BY clauses, make sure that trailing terms
# of the ORDER BY clause do not reference other tables in a join.
#
if {[permutation] != "no_optimization"} {
do_test where-14.1 {
  execsql {
    CREATE TABLE t8(a INTEGER PRIMARY KEY, b TEXT UNIQUE);
    INSERT INTO t8 VALUES(1,'one');
    INSERT INTO t8 VALUES(4,'four');
  }
  cksort {
................................................................................
  } 
} {4/1 4/4 1/1 1/4 sort}
do_test where-14.12 {
  cksort {
    SELECT x.a || '/' || y.a FROM t8 x, t8 y ORDER BY x.b, y.a||x.b DESC
  } 
} {4/4 4/1 1/4 1/1 sort}
} ;# {permutation != "no_optimization"}

# Ticket #2445.
#
# There was a crash that could occur when a where clause contains an
# alias for an expression in the result set, and that expression retrieves
# a column of the second or subsequent table in a join.
#