SQLite

# When compiling for use in the WinRT environment, the following
# linker option must be used to mark the executable as runnable
# only in the context of an application container.
#
!IF $(FOR_WINRT)!=0
LTLINKOPTS = $(LTLINKOPTS) /APPCONTAINER
!IF "$(VISUALSTUDIOVERSION)"=="12.0"
!IF "$(PLATFORM)"=="x86"
LTLINKOPTS = $(LTLINKOPTS) "/LIBPATH:$(VCINSTALLDIR)\lib\store"
!ELSEIF "$(PLATFORM)"=="x64"
LTLINKOPTS = $(LTLINKOPTS) "/LIBPATH:$(VCINSTALLDIR)\lib\store\amd64"
!ELSEIF "$(PLATFORM)"=="ARM"
LTLINKOPTS = $(LTLINKOPTS) "/LIBPATH:$(VCINSTALLDIR)\lib\store\arm"
!ELSE
LTLINKOPTS = $(LTLINKOPTS) "/LIBPATH:$(VCINSTALLDIR)\lib\store"
!ENDIF
!ENDIF
!ENDIF

# If either debugging or symbols are enabled, enable PDBs.
!IF $(DEBUG)>0 || $(SYMBOLS)!=0
LDFLAGS = /DEBUG
!ENDIF

**   2. Full-text search using a MATCH operator on a non-docid column.
**   3. Linear scan of %_content table.
*/
static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
  Fts3Table *p = (Fts3Table *)pVTab;
  int i;                          /* Iterator variable */
  int iCons = -1;                 /* Index of constraint to use */

  int iLangidCons = -1;           /* Index of langid=x constraint, if present */
  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
  int iIdx;

  /* By default use a full table scan. This is an expensive option,
  ** so search through the constraints to see if a more efficient 
  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 5000000;
  for(i=0; i<pInfo->nConstraint; i++){
    int bDocid;                 /* True if this constraint is on docid */
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ) continue;

    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);

    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */

    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){


      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;
      iCons = i;
    }

    /* A MATCH constraint. Use a full-text search.
    **

    /* Equality constraint on the langid column */
    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && pCons->iColumn==p->nColumn + 2
    ){
      iLangidCons = i;
    }

    if( bDocid ){
      switch( pCons->op ){
        case SQLITE_INDEX_CONSTRAINT_GE:
        case SQLITE_INDEX_CONSTRAINT_GT:
          iDocidGe = i;
          break;

        case SQLITE_INDEX_CONSTRAINT_LE:
        case SQLITE_INDEX_CONSTRAINT_LT:
          iDocidLe = i;
          break;
      }
    }
  }

  iIdx = 1;
  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
  if( iLangidCons>=0 ){
    pInfo->idxNum |= FTS3_HAVE_LANGID;
    pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
  } 
  if( iDocidGe>=0 ){
    pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
    pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
  } 
  if( iDocidLe>=0 ){
    pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
    pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
  } 

  /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
  ** docid) order. Both ascending and descending are possible. 
  */
  if( pInfo->nOrderBy==1 ){
    struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];

    }
  }else{
    rc = fts3EvalNext((Fts3Cursor *)pCursor);
  }
  assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
  return rc;
}

/*
** The following are copied from sqliteInt.h.
**
** Constants for the largest and smallest possible 64-bit signed integers.
** These macros are designed to work correctly on both 32-bit and 64-bit
** compilers.
*/
#ifndef SQLITE_AMALGAMATION
# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** If the numeric type of argument pVal is "integer", then return it
** converted to a 64-bit signed integer. Otherwise, return a copy of
** the second parameter, iDefault.
*/
static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
  if( pVal ){
    int eType = sqlite3_value_numeric_type(pVal);
    if( eType==SQLITE_INTEGER ){
      return sqlite3_value_int64(pVal);
    }
  }
  return iDefault;
}

/*
** This is the xFilter interface for the virtual table.  See
** the virtual table xFilter method documentation for additional
** information.
**
** If idxNum==FTS3_FULLSCAN_SEARCH then do a full table scan against

  int idxNum,                     /* Strategy index */
  const char *idxStr,             /* Unused */
  int nVal,                       /* Number of elements in apVal */
  sqlite3_value **apVal           /* Arguments for the indexing scheme */
){
  int rc;
  char *zSql;                     /* SQL statement used to access %_content */
  int eSearch;
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;
  Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  sqlite3_value *pCons = 0;       /* The MATCH or rowid constraint, if any */
  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
  int iIdx;

  UNUSED_PARAMETER(idxStr);
  UNUSED_PARAMETER(nVal);

  eSearch = (idxNum & 0x0000FFFF);
  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( p->pSegments==0 );

  /* Collect arguments into local variables */
  iIdx = 0;
  if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
  if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
  if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
  if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
  assert( iIdx==nVal );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));

  /* Set the lower and upper bounds on docids to return */
  pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
  pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);

  if( idxStr ){
    pCsr->bDesc = (idxStr[0]=='D');
  }else{
    pCsr->bDesc = p->bDescIdx;
  }
  pCsr->eSearch = (i16)eSearch;

  if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){
    int iCol = eSearch-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(pCons);

    if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }

    pCsr->iLangid = 0;
    if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);

    assert( p->base.zErrMsg==0 );
    rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 
        &p->base.zErrMsg
    );
    if( rc!=SQLITE_OK ){

  }

  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
  ** statement loops through all rows of the %_content table. For a
  ** full-text query or docid lookup, the statement retrieves a single
  ** row by docid.
  */
  if( eSearch==FTS3_FULLSCAN_SEARCH ){
    zSql = sqlite3_mprintf(
        "SELECT %s ORDER BY rowid %s",
        p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
    );
    if( zSql ){
      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pCsr->pStmt, 0);
      sqlite3_free(zSql);
    }else{
      rc = SQLITE_NOMEM;
    }
  }else if( eSearch==FTS3_DOCID_SEARCH ){
    rc = fts3CursorSeekStmt(pCsr, &pCsr->pStmt);
    if( rc==SQLITE_OK ){
      rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);
    }
  }
  if( rc!=SQLITE_OK ) return rc;

  return fts3NextMethod(pCursor);
}

      sqlite3_free(aPoslist);
    }
  }

  return SQLITE_OK;
}

/*
** Maximum number of tokens a phrase may have to be considered for the
** incremental doclists strategy.
*/
#define MAX_INCR_PHRASE_TOKENS 4

/*
** This function is called for each Fts3Phrase in a full-text query 
** expression to initialize the mechanism for returning rows. Once this
** function has been called successfully on an Fts3Phrase, it may be
** used with fts3EvalPhraseNext() to iterate through the matching docids.
**
** If parameter bOptOk is true, then the phrase may (or may not) use the
** incremental loading strategy. Otherwise, the entire doclist is loaded into
** memory within this call.
**
** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
*/
static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){


  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  int rc = SQLITE_OK;             /* Error code */
  int i;

  /* Determine if doclists may be loaded from disk incrementally. This is
  ** possible if the bOptOk argument is true, the FTS doclists will be
  ** scanned in forward order, and the phrase consists of 
  ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
  ** tokens or prefix tokens that cannot use a prefix-index.  */
  int bHaveIncr = 0;
  int bIncrOk = (bOptOk 
   && pCsr->bDesc==pTab->bDescIdx 
   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
#ifdef SQLITE_TEST
   && pTab->bNoIncrDoclist==0
#endif
  );
  for(i=0; bIncrOk==1 && i<p->nToken; i++){
    Fts3PhraseToken *pToken = &p->aToken[i];
    if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
      bIncrOk = 0;
    }
    if( pToken->pSegcsr ) bHaveIncr = 1;
  }

  if( bIncrOk && bHaveIncr ){
    /* Use the incremental approach. */
    int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);
    for(i=0; rc==SQLITE_OK && i<p->nToken; i++){
      Fts3PhraseToken *pToken = &p->aToken[i];
      Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;
      if( pSegcsr ){
        rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);


      }
    }
    p->bIncr = 1;
  }else{
    /* Load the full doclist for the phrase into memory. */
    rc = fts3EvalPhraseLoad(pCsr, p);
    p->bIncr = 0;
  }

  assert( rc!=SQLITE_OK || p->nToken<1 || p->aToken[0].pSegcsr==0 || p->bIncr );

      p += sqlite3Fts3GetVarint(p, &iVar);
      *piDocid += ((bDescIdx ? -1 : 1) * iVar);
    }
  }

  *ppIter = p;
}

/*
** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof
** to true if EOF is reached.
*/
static void fts3EvalDlPhraseNext(
  Fts3Table *pTab,
  Fts3Doclist *pDL,
  u8 *pbEof
){
  char *pIter;                            /* Used to iterate through aAll */
  char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
 
  if( pDL->pNextDocid ){
    pIter = pDL->pNextDocid;
  }else{
    pIter = pDL->aAll;
  }

  if( pIter>=pEnd ){
    /* We have already reached the end of this doclist. EOF. */
    *pbEof = 1;
  }else{
    sqlite3_int64 iDelta;
    pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
    if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
      pDL->iDocid += iDelta;
    }else{
      pDL->iDocid -= iDelta;
    }
    pDL->pList = pIter;
    fts3PoslistCopy(0, &pIter);
    pDL->nList = (int)(pIter - pDL->pList);

    /* pIter now points just past the 0x00 that terminates the position-
    ** list for document pDL->iDocid. However, if this position-list was
    ** edited in place by fts3EvalNearTrim(), then pIter may not actually
    ** point to the start of the next docid value. The following line deals
    ** with this case by advancing pIter past the zero-padding added by
    ** fts3EvalNearTrim().  */
    while( pIter<pEnd && *pIter==0 ) pIter++;

    pDL->pNextDocid = pIter;
    assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
    *pbEof = 0;
  }
}

/*
** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().
*/
typedef struct TokenDoclist TokenDoclist;
struct TokenDoclist {
  int bIgnore;
  sqlite3_int64 iDocid;
  char *pList;
  int nList;
};

/*
** Token pToken is an incrementally loaded token that is part of a 
** multi-token phrase. Advance it to the next matching document in the
** database and populate output variable *p with the details of the new
** entry. Or, if the iterator has reached EOF, set *pbEof to true.
**
** If an error occurs, return an SQLite error code. Otherwise, return 
** SQLITE_OK.
*/
static int incrPhraseTokenNext(
  Fts3Table *pTab,                /* Virtual table handle */
  Fts3Phrase *pPhrase,            /* Phrase to advance token of */
  int iToken,                     /* Specific token to advance */
  TokenDoclist *p,                /* OUT: Docid and doclist for new entry */
  u8 *pbEof                       /* OUT: True if iterator is at EOF */
){
  int rc = SQLITE_OK;

  if( pPhrase->iDoclistToken==iToken ){
    assert( p->bIgnore==0 );
    assert( pPhrase->aToken[iToken].pSegcsr==0 );
    fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);
    p->pList = pPhrase->doclist.pList;
    p->nList = pPhrase->doclist.nList;
    p->iDocid = pPhrase->doclist.iDocid;
  }else{
    Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
    assert( pToken->pDeferred==0 );
    assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );
    if( pToken->pSegcsr ){
      assert( p->bIgnore==0 );
      rc = sqlite3Fts3MsrIncrNext(
          pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList
      );
      if( p->pList==0 ) *pbEof = 1;
    }else{
      p->bIgnore = 1;
    }
  }

  return rc;
}


/*
** The phrase iterator passed as the second argument:
**
**   * features at least one token that uses an incremental doclist, and 
**
**   * does not contain any deferred tokens.
**
** Advance it to the next matching documnent in the database and populate
** the Fts3Doclist.pList and nList fields. 
**
** If there is no "next" entry and no error occurs, then *pbEof is set to
** 1 before returning. Otherwise, if no error occurs and the iterator is
** successfully advanced, *pbEof is set to 0.
**
** If an error occurs, return an SQLite error code. Otherwise, return 
** SQLITE_OK.
*/
static int fts3EvalIncrPhraseNext(
  Fts3Cursor *pCsr,               /* FTS Cursor handle */
  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
  u8 *pbEof                       /* OUT: Set to 1 if EOF */
){
  int rc = SQLITE_OK;
  Fts3Doclist *pDL = &p->doclist;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
  u8 bEof = 0;

  /* This is only called if it is guaranteed that the phrase has at least
  ** one incremental token. In which case the bIncr flag is set. */
  assert( p->bIncr==1 );

  if( p->nToken==1 && p->bIncr ){
    rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr, 
        &pDL->iDocid, &pDL->pList, &pDL->nList
    );
    if( pDL->pList==0 ) bEof = 1;
  }else{
    int bDescDoclist = pCsr->bDesc;
    struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];

    memset(a, 0, sizeof(a));
    assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );
    assert( p->iDoclistToken<MAX_INCR_PHRASE_TOKENS );

    while( bEof==0 ){
      int bMaxSet = 0;
      sqlite3_int64 iMax;         /* Largest docid for all iterators */
      int i;                      /* Used to iterate through tokens */

      /* Advance the iterator for each token in the phrase once. */
      for(i=0; rc==SQLITE_OK && i<p->nToken; i++){
        rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
        if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){
          iMax = a[i].iDocid;
          bMaxSet = 1;
        }
      }
      assert( rc!=SQLITE_OK || a[p->nToken-1].bIgnore==0 );
      assert( rc!=SQLITE_OK || bMaxSet );

      /* Keep advancing iterators until they all point to the same document */
      for(i=0; i<p->nToken; i++){
        while( rc==SQLITE_OK && bEof==0 
            && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0 
        ){
          rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
          if( DOCID_CMP(a[i].iDocid, iMax)>0 ){
            iMax = a[i].iDocid;
            i = 0;
          }
        }
      }

      /* Check if the current entries really are a phrase match */
      if( bEof==0 ){
        int nList = 0;
        int nByte = a[p->nToken-1].nList;
        char *aDoclist = sqlite3_malloc(nByte+1);
        if( !aDoclist ) return SQLITE_NOMEM;
        memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);

        for(i=0; i<(p->nToken-1); i++){
          if( a[i].bIgnore==0 ){
            char *pL = a[i].pList;
            char *pR = aDoclist;
            char *pOut = aDoclist;
            int nDist = p->nToken-1-i;
            int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);
            if( res==0 ) break;
            nList = (pOut - aDoclist);
          }
        }
        if( i==(p->nToken-1) ){
          pDL->iDocid = iMax;
          pDL->pList = aDoclist;
          pDL->nList = nList;
          pDL->bFreeList = 1;
          break;
        }
        sqlite3_free(aDoclist);
      }
    }
  }

  *pbEof = bEof;
  return rc;
}

/*
** Attempt to move the phrase iterator to point to the next matching docid. 
** If an error occurs, return an SQLite error code. Otherwise, return 
** SQLITE_OK.
**
** If there is no "next" entry and no error occurs, then *pbEof is set to
** 1 before returning. Otherwise, if no error occurs and the iterator is
** successfully advanced, *pbEof is set to 0.
*/
static int fts3EvalPhraseNext(
  Fts3Cursor *pCsr,               /* FTS Cursor handle */
  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
  u8 *pbEof                       /* OUT: Set to 1 if EOF */
){
  int rc = SQLITE_OK;
  Fts3Doclist *pDL = &p->doclist;
  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  if( p->bIncr ){






    rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);

  }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){
    sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll, 
        &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof
    );
    pDL->pList = pDL->pNextDocid;
  }else{







    fts3EvalDlPhraseNext(pTab, pDL, pbEof);



























  }

  return rc;
}

/*
**

**
** If an error occurs within this function, *pRc is set to an SQLite error
** code before returning.
*/
static void fts3EvalStartReaders(
  Fts3Cursor *pCsr,               /* FTS Cursor handle */
  Fts3Expr *pExpr,                /* Expression to initialize phrases in */

  int *pRc                        /* IN/OUT: Error code */
){
  if( pExpr && SQLITE_OK==*pRc ){
    if( pExpr->eType==FTSQUERY_PHRASE ){
      int i;
      int nToken = pExpr->pPhrase->nToken;
      for(i=0; i<nToken; i++){
        if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;
      }
      pExpr->bDeferred = (i==nToken);
      *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);
    }else{
      fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);
      fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);
      pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);
    }
  }
}

/*
** An array of the following structures is assembled as part of the process

      pToken->pSegcsr = 0;
    }else{
      /* Set nLoad4 to the value of (4^nOther) for the next iteration of the
      ** for-loop. Except, limit the value to 2^24 to prevent it from 
      ** overflowing the 32-bit integer it is stored in. */
      if( ii<12 ) nLoad4 = nLoad4*4;

      if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){
        /* Either this is the cheapest token in the entire query, or it is
        ** part of a multi-token phrase. Either way, the entire doclist will
        ** (eventually) be loaded into memory. It may as well be now. */
        Fts3PhraseToken *pToken = pTC->pToken;
        int nList = 0;
        char *pList = 0;
        rc = fts3TermSelect(pTab, pToken, pTC->iCol, &nList, &pList);

      }

      sqlite3_free(aTC);
    }
  }
#endif

  fts3EvalStartReaders(pCsr, pCsr->pExpr, &rc);
  return rc;
}

/*
** Invalidate the current position list for phrase pPhrase.
*/
static void fts3EvalInvalidatePoslist(Fts3Phrase *pPhrase){

      fts3EvalNextRow(pCsr, pExpr, &rc);
      pCsr->isEof = pExpr->bEof;
      pCsr->isRequireSeek = 1;
      pCsr->isMatchinfoNeeded = 1;
      pCsr->iPrevId = pExpr->iDocid;
    }while( pCsr->isEof==0 && fts3EvalTestDeferredAndNear(pCsr, &rc) );
  }

  /* Check if the cursor is past the end of the docid range specified
  ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */
  if( rc==SQLITE_OK && (
        (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
     || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)
  )){
    pCsr->isEof = 1;
  }

  return rc;
}

/*
** Restart interation for expression pExpr so that the next call to
** fts3EvalNext() visits the first row. Do not allow incremental 
** loading or merging of phrase doclists for this iteration.

){
  if( pExpr && *pRc==SQLITE_OK ){
    Fts3Phrase *pPhrase = pExpr->pPhrase;

    if( pPhrase ){
      fts3EvalInvalidatePoslist(pPhrase);
      if( pPhrase->bIncr ){
        int i;
        for(i=0; i<pPhrase->nToken; i++){
          Fts3PhraseToken *pToken = &pPhrase->aToken[i];
          assert( pToken->pDeferred==0 );
          if( pToken->pSegcsr ){
            sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);

          }
        }
        *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);
      }
      pPhrase->doclist.pNextDocid = 0;
      pPhrase->doclist.iDocid = 0;
    }

    pExpr->iDocid = 0;
    pExpr->bEof = 0;
    pExpr->bStart = 0;

    return SQLITE_OK;
  }

  iDocid = pExpr->iDocid;
  pIter = pPhrase->doclist.pList;
  if( iDocid!=pCsr->iPrevId || pExpr->bEof ){
    int bDescDoclist = pTab->bDescIdx;      /* For DOCID_CMP macro */
    int iMul;                     /* +1 if csr dir matches index dir, else -1 */
    int bOr = 0;
    u8 bEof = 0;
    u8 bTreeEof = 0;
    Fts3Expr *p;                  /* Used to iterate from pExpr to root */
    Fts3Expr *pNear;              /* Most senior NEAR ancestor (or pExpr) */

    /* Check if this phrase descends from an OR expression node. If not, 
    ** return NULL. Otherwise, the entry that corresponds to docid 
    ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the
    ** tree that the node is part of has been marked as EOF, but the node
    ** itself is not EOF, then it may point to an earlier entry. */
    pNear = pExpr;
    for(p=pExpr->pParent; p; p=p->pParent){
      if( p->eType==FTSQUERY_OR ) bOr = 1;
      if( p->eType==FTSQUERY_NEAR ) pNear = p;
      if( p->bEof ) bTreeEof = 1;
    }
    if( bOr==0 ) return SQLITE_OK;

    /* This is the descendent of an OR node. In this case we cannot use
    ** an incremental phrase. Load the entire doclist for the phrase
    ** into memory in this case.  */
    if( pPhrase->bIncr ){
      int rc = SQLITE_OK;
      int bEofSave = pExpr->bEof;
      fts3EvalRestart(pCsr, pExpr, &rc);
      while( rc==SQLITE_OK && !pExpr->bEof ){
        fts3EvalNextRow(pCsr, pExpr, &rc);
        if( bEofSave==0 && pExpr->iDocid==iDocid ) break;
      }
      pIter = pPhrase->doclist.pList;
      assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );
      if( rc!=SQLITE_OK ) return rc;
    }
    
    iMul = ((pCsr->bDesc==bDescDoclist) ? 1 : -1);
    while( bTreeEof==1 
        && pNear->bEof==0
        && (DOCID_CMP(pNear->iDocid, pCsr->iPrevId) * iMul)<0
    ){
      int rc = SQLITE_OK;
      fts3EvalNextRow(pCsr, pExpr, &rc);
      if( rc!=SQLITE_OK ) return rc;
      iDocid = pExpr->iDocid;
      pIter = pPhrase->doclist.pList;
    }

    bEof = (pPhrase->doclist.nAll==0);
    assert( bDescDoclist==0 || bDescDoclist==1 );
    assert( pCsr->bDesc==0 || pCsr->bDesc==1 );

    if( bEof==0 ){
      if( pCsr->bDesc==bDescDoclist ){
        int dummy;
        if( pNear->bEof ){
          /* This expression is already at EOF. So position it to point to the
          ** last entry in the doclist at pPhrase->doclist.aAll[]. Variable
          ** iDocid is already set for this entry, so all that is required is
          ** to set pIter to point to the first byte of the last position-list
          ** in the doclist. 
          **
          ** It would also be correct to set pIter and iDocid to zero. In
          ** this case, the first call to sqltie3Fts4DoclistPrev() below
          ** would also move the iterator to point to the last entry in the 
          ** doclist. However, this is expensive, as to do so it has to 
          ** iterate through the entire doclist from start to finish (since
          ** it does not know the docid for the last entry).  */
          pIter = &pPhrase->doclist.aAll[pPhrase->doclist.nAll-1];
          fts3ReversePoslist(pPhrase->doclist.aAll, &pIter);
        }
        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
          sqlite3Fts3DoclistPrev(
              bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
              &pIter, &iDocid, &dummy, &bEof
          );
        }
      }else{
        if( pNear->bEof ){
          pIter = 0;
          iDocid = 0;
        }
        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
          sqlite3Fts3DoclistNext(
              bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
              &pIter, &iDocid, &bEof
          );
        }
      }
    }

    if( bEof || iDocid!=pCsr->iPrevId ) pIter = 0;
  }
  if( pIter==0 ) return SQLITE_OK;

  ** methods of the virtual table are called at appropriate times.  These
  ** values do not contribute to FTS functionality; they are used for
  ** verifying the operation of the SQLite core.
  */
  int inTransaction;     /* True after xBegin but before xCommit/xRollback */
  int mxSavepoint;       /* Largest valid xSavepoint integer */
#endif

#ifdef SQLITE_TEST
  /* True to disable the incremental doclist optimization. This is controled
  ** by special insert command 'test-no-incr-doclist'.  */
  int bNoIncrDoclist;
#endif
};

/*
** When the core wants to read from the virtual table, it creates a
** virtual table cursor (an instance of the following structure) using
** the xOpen method. Cursors are destroyed using the xClose method.
*/

  char *pNextId;                  /* Pointer into the body of aDoclist */
  char *aDoclist;                 /* List of docids for full-text queries */
  int nDoclist;                   /* Size of buffer at aDoclist */
  u8 bDesc;                       /* True to sort in descending order */
  int eEvalmode;                  /* An FTS3_EVAL_XX constant */
  int nRowAvg;                    /* Average size of database rows, in pages */
  sqlite3_int64 nDoc;             /* Documents in table */
  i64 iMinDocid;                  /* Minimum docid to return */
  i64 iMaxDocid;                  /* Maximum docid to return */
  int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
  u32 *aMatchinfo;                /* Information about most recent match */
  int nMatchinfo;                 /* Number of elements in aMatchinfo[] */
  char *zMatchinfo;               /* Matchinfo specification */
};

#define FTS3_EVAL_FILTER    0

** indicating that all columns should be searched,
** then eSearch would be set to FTS3_FULLTEXT_SEARCH+4.
*/
#define FTS3_FULLSCAN_SEARCH 0    /* Linear scan of %_content table */
#define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
#define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */

/*
** The lower 16-bits of the sqlite3_index_info.idxNum value set by
** the xBestIndex() method contains the Fts3Cursor.eSearch value described
** above. The upper 16-bits contain a combination of the following
** bits, used to describe extra constraints on full-text searches.
*/
#define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */
#define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */
#define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */

struct Fts3Doclist {
  char *aAll;                    /* Array containing doclist (or NULL) */
  int nAll;                      /* Size of a[] in bytes */
  char *pNextDocid;              /* Pointer to next docid */

  sqlite3_int64 iDocid;          /* Current docid (if pList!=0) */

  p->bAutoincrmerge = fts3Getint(&zParam)!=0;
  if( !p->bHasStat ){
    assert( p->bFts4==0 );
    sqlite3Fts3CreateStatTable(&rc, p);
    if( rc ) return rc;
  }
  rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
  if( rc ) return rc;
  sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
  sqlite3_bind_int(pStmt, 2, p->bAutoincrmerge);
  sqlite3_step(pStmt);
  rc = sqlite3_reset(pStmt);
  return rc;
}

    rc = fts3DoAutoincrmerge(p, &zVal[10]);
#ifdef SQLITE_TEST
  }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
    p->nNodeSize = atoi(&zVal[9]);
    rc = SQLITE_OK;
  }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
    p->nMaxPendingData = atoi(&zVal[11]);
    rc = SQLITE_OK;
  }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){
    p->bNoIncrDoclist = atoi(&zVal[21]);
    rc = SQLITE_OK;
#endif
  }else{
    rc = SQLITE_ERROR;
  }

  return rc;

    amatchVCheckClear(p);
    sqlite3_free(p->zClassName);
    sqlite3_free(p->zDb);
    sqlite3_free(p->zCostTab);
    sqlite3_free(p->zVocabTab);
    sqlite3_free(p->zVocabWord);
    sqlite3_free(p->zVocabLang);
    sqlite3_free(p->zSelf);
    memset(p, 0, sizeof(*p));
    sqlite3_free(p);
  }
}

/*
** xDisconnect/xDestroy method for the amatch module.

  for(pWord=pCur->pAllWords; pWord; pWord=pNextWord){
    pNextWord = pWord->pNext;
    sqlite3_free(pWord);
  }
  pCur->pAllWords = 0;
  sqlite3_free(pCur->zInput);
  pCur->zInput = 0;
  sqlite3_free(pCur->zBuf);
  pCur->zBuf = 0;
  pCur->nBuf = 0;
  pCur->pCost = 0;
  pCur->pWord = 0;
  pCur->pCurrent = 0;
  pCur->rLimit = 1000000;
  pCur->iLang = 0;
  pCur->nWord = 0;
}

  char zNextIn[8];
  int nNextIn;

  if( p->pVCheck==0 ){
    char *zSql;
    if( p->zVocabLang && p->zVocabLang[0] ){
      zSql = sqlite3_mprintf(
          "SELECT \"%w\" FROM \"%w\"",
          " WHERE \"%w\">=?1 AND \"%w\"=?2"
          " ORDER BY 1",
          p->zVocabWord, p->zVocabTab,
          p->zVocabWord, p->zVocabLang
      );
    }else{
      zSql = sqlite3_mprintf(
          "SELECT \"%w\" FROM \"%w\""
          " WHERE \"%w\">=?1"
          " ORDER BY 1",
          p->zVocabWord, p->zVocabTab,
          p->zVocabWord
      );
    }
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &p->pVCheck, 0);

** Further suppose that for user keypad entry, it is desired to disable
** (gray out) keys that are not valid as the next character.  If the
** the user has previously entered (say) 'cha' then to find all allowed
** next characters (and thereby determine when keys should not be grayed
** out) run the following query:
**
**   SELECT next_char('cha','dictionary','word');
**
** IMPLEMENTATION NOTES:
**
** The next_char function is implemented using recursive SQL that makes
** use of the table name and column name as part of a query.  If either
** the table name or column name are keywords or contain special characters,
** then they should be escaped.  For example:
**
**   SELECT next_char('cha','[dictionary]','[word]');
**
** This also means that the table name can be a subquery:
**
**   SELECT next_char('cha','(SELECT word AS w FROM dictionary)','w');
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** A structure to hold context of the next_char() computation across

      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
      return;
    }
  }else{
    zColl = "";
  }
  zSql = sqlite3_mprintf(
    "SELECT %s FROM %s"
    " WHERE %s>=(?1 || ?2) %s"
    "   AND %s<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
    "   %s"
    " ORDER BY 1 %s ASC LIMIT 1",
    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
  );
  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
  if( zColl[0] ) sqlite3_free(zColl);
  if( zSql==0 ){

/*
** 2013-10-09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains the implementation of an SQLite vfs wrapper for
** unix that generates per-database log files of all disk activity.
*/

/*
** This module contains code for a wrapper VFS that causes a log of
** most VFS calls to be written into a file on disk. The log 
** is stored as comma-separated variables.
**
** All calls on sqlite3_file objects are logged.
** Additionally, calls to the xAccess(), xOpen(), and xDelete()
** methods are logged. The other sqlite3_vfs object methods (xDlXXX,
** xRandomness, xSleep, xCurrentTime, xGetLastError and xCurrentTimeInt64) 
** are not logged.
*/

#include "sqlite3.h"
#include <string.h>
#include <assert.h>
#include <stdio.h>

/*
** Forward declaration of objects used by this utility
*/
typedef struct VLogLog VLogLog;
typedef struct VLogVfs VLogVfs;
typedef struct VLogFile VLogFile;

/* There is a pair (an array of size 2) of the following objects for
** each database file being logged.  The first contains the filename
** and is used to log I/O with the main database.  The second has
** a NULL filename and is used to log I/O for the journal.  Both
** out pointers are the same.
*/
struct VLogLog {
  VLogLog *pNext;                 /* Next in a list of all active logs */
  VLogLog **ppPrev;               /* Pointer to this in the list */
  int nRef;                       /* Number of references to this object */
  int nFilename;                  /* Length of zFilename in bytes */
  char *zFilename;                /* Name of database file.  NULL for journal */
  FILE *out;                      /* Write information here */
};

struct VLogVfs {
  sqlite3_vfs base;               /* VFS methods */
  sqlite3_vfs *pVfs;              /* Parent VFS */
};

struct VLogFile {
  sqlite3_file base;              /* IO methods */
  sqlite3_file *pReal;            /* Underlying file handle */
  VLogLog *pLog;                  /* The log file for this file */
};

#define REALVFS(p) (((VLogVfs*)(p))->pVfs)

/*
** Methods for VLogFile
*/
static int vlogClose(sqlite3_file*);
static int vlogRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int vlogWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
static int vlogTruncate(sqlite3_file*, sqlite3_int64 size);
static int vlogSync(sqlite3_file*, int flags);
static int vlogFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int vlogLock(sqlite3_file*, int);
static int vlogUnlock(sqlite3_file*, int);
static int vlogCheckReservedLock(sqlite3_file*, int *pResOut);
static int vlogFileControl(sqlite3_file*, int op, void *pArg);
static int vlogSectorSize(sqlite3_file*);
static int vlogDeviceCharacteristics(sqlite3_file*);

/*
** Methods for VLogVfs
*/
static int vlogOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int vlogDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int vlogAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int vlogFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
static void *vlogDlOpen(sqlite3_vfs*, const char *zFilename);
static void vlogDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*vlogDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
static void vlogDlClose(sqlite3_vfs*, void*);
static int vlogRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int vlogSleep(sqlite3_vfs*, int microseconds);
static int vlogCurrentTime(sqlite3_vfs*, double*);
static int vlogGetLastError(sqlite3_vfs*, int, char *);
static int vlogCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);

static VLogVfs vlog_vfs = {
  {
    1,                            /* iVersion */
    0,                            /* szOsFile (set by register_vlog()) */
    1024,                         /* mxPathname */
    0,                            /* pNext */
    "vfslog",                     /* zName */
    0,                            /* pAppData */
    vlogOpen,                     /* xOpen */
    vlogDelete,                   /* xDelete */
    vlogAccess,                   /* xAccess */
    vlogFullPathname,             /* xFullPathname */
    vlogDlOpen,                   /* xDlOpen */
    vlogDlError,                  /* xDlError */
    vlogDlSym,                    /* xDlSym */
    vlogDlClose,                  /* xDlClose */
    vlogRandomness,               /* xRandomness */
    vlogSleep,                    /* xSleep */
    vlogCurrentTime,              /* xCurrentTime */
    vlogGetLastError,             /* xGetLastError */
    vlogCurrentTimeInt64          /* xCurrentTimeInt64 */
  },
  0
};

static sqlite3_io_methods vlog_io_methods = {
  1,                              /* iVersion */
  vlogClose,                      /* xClose */
  vlogRead,                       /* xRead */
  vlogWrite,                      /* xWrite */
  vlogTruncate,                   /* xTruncate */
  vlogSync,                       /* xSync */
  vlogFileSize,                   /* xFileSize */
  vlogLock,                       /* xLock */
  vlogUnlock,                     /* xUnlock */
  vlogCheckReservedLock,          /* xCheckReservedLock */
  vlogFileControl,                /* xFileControl */
  vlogSectorSize,                 /* xSectorSize */
  vlogDeviceCharacteristics,      /* xDeviceCharacteristics */
  0,                              /* xShmMap */
  0,                              /* xShmLock */
  0,                              /* xShmBarrier */
  0                               /* xShmUnmap */
};

#if SQLITE_OS_UNIX && !defined(NO_GETTOD)
#include <sys/time.h>
static sqlite3_uint64 vlog_time(){
  struct timeval sTime;
  gettimeofday(&sTime, 0);
  return sTime.tv_usec + (sqlite3_uint64)sTime.tv_sec * 1000000;
}
#elif SQLITE_OS_WIN
#include <windows.h>
#include <time.h>
static sqlite3_uint64 vlog_time(){
  FILETIME ft;
  sqlite3_uint64 u64time = 0;
 
  GetSystemTimeAsFileTime(&ft);

  u64time |= ft.dwHighDateTime;
  u64time <<= 32;
  u64time |= ft.dwLowDateTime;

  /* ft is 100-nanosecond intervals, we want microseconds */
  return u64time /(sqlite3_uint64)10;
}
#else
static sqlite3_uint64 vlog_time(){
  return 0;
}
#endif


/*
** Write a message to the log file
*/
static void vlogLogPrint(
  VLogLog *pLog,                 /* The log file to write into */
  sqlite3_int64 tStart,            /* Start time of system call */
  sqlite3_int64 tElapse,           /* Elapse time of system call */
  const char *zOp,                 /* Type of system call */
  sqlite3_int64 iArg1,             /* First argument */
  sqlite3_int64 iArg2,             /* Second argument */
  const char *zArg3,               /* Third argument */
  int iRes                         /* Result */
){
  char z1[40], z2[40], z3[70];
  if( pLog==0 ) return;
  if( iArg1>=0 ){
    sqlite3_snprintf(sizeof(z1), z1, "%lld", iArg1);
  }else{
    z1[0] = 0;
  }
  if( iArg2>=0 ){
    sqlite3_snprintf(sizeof(z2), z2, "%lld", iArg2);
  }else{
    z2[0] = 0;
  }
  if( zArg3 ){
    sqlite3_snprintf(sizeof(z3), z3, "\"%s\"", zArg3);
  }else{
    z3[0] = 0;
  }
  fprintf(pLog->out,"%lld,%lld,%s,%d,%s,%s,%s,%d\n",
      tStart, tElapse, zOp, pLog->zFilename==0, z1, z2, z3, iRes);
}

/*
** List of all active log connections.  Protected by the master mutex.
*/
static VLogLog *allLogs = 0;

/*
** Close a VLogLog object
*/
static void vlogLogClose(VLogLog *p){
  if( p ){
    sqlite3_mutex *pMutex;
    p->nRef--;
    if( p->nRef>0 || p->zFilename==0 ) return;
    pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
    sqlite3_mutex_enter(pMutex);
    *p->ppPrev = p->pNext;
    if( p->pNext ) p->pNext->ppPrev = p->ppPrev;
    sqlite3_mutex_leave(pMutex);
    fclose(p->out);
    sqlite3_free(p);
  }
}

/*
** Open a VLogLog object on the given file
*/
static VLogLog *vlogLogOpen(const char *zFilename){
  int nName = (int)strlen(zFilename);
  int isJournal = 0;
  sqlite3_mutex *pMutex;
  VLogLog *pLog, *pTemp;
  sqlite3_int64 tNow = 0;
  if( nName>4 && strcmp(zFilename+nName-4,"-wal")==0 ){
    return 0;  /* Do not log wal files */
  }else
  if( nName>8 && strcmp(zFilename+nName-8,"-journal")==0 ){
    nName -= 8;
    isJournal = 1;
  }else if( nName>12 
         && sqlite3_strglob("-mj??????9??", zFilename+nName-12)==0 ){
    return 0;  /* Do not log master journal files */
  }
  pTemp = sqlite3_malloc( sizeof(*pLog)*2 + nName + 60 );
  if( pTemp==0 ) return 0;
  pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
  sqlite3_mutex_enter(pMutex);
  for(pLog=allLogs; pLog; pLog=pLog->pNext){
    if( pLog->nFilename==nName && !memcmp(pLog->zFilename, zFilename, nName) ){
      break;
    }
  }
  if( pLog==0 ){
    pLog = pTemp;
    pTemp = 0;
    memset(pLog, 0, sizeof(*pLog)*2);
    pLog->zFilename = (char*)&pLog[2];
    tNow = vlog_time();
    sqlite3_snprintf(nName+60, pLog->zFilename, "%.*s-debuglog-%lld",
                     nName, zFilename, tNow);
    pLog->out = fopen(pLog->zFilename, "a");
    if( pLog->out==0 ){
      sqlite3_mutex_leave(pMutex);
      sqlite3_free(pLog);
      return 0;
    }
    pLog->nFilename = nName;
    pLog[1].out = pLog[0].out;
    pLog->ppPrev = &allLogs;
    if( allLogs ) allLogs->ppPrev = &pLog->pNext;
    pLog->pNext = allLogs;
    allLogs = pLog;
  }
  sqlite3_mutex_leave(pMutex);
  if( pTemp ){
    sqlite3_free(pTemp);
  }else{
    char zHost[200];
    zHost[0] = 0;
    gethostname(zHost, sizeof(zHost)-1);
    zHost[sizeof(zHost)-1] = 0;
    vlogLogPrint(pLog, tNow, 0, "IDENT", getpid(), -1, zHost, 0);
  }
  if( pLog && isJournal ) pLog++;
  pLog->nRef++;
  return pLog;
}


/*
** Close an vlog-file.
*/
static int vlogClose(sqlite3_file *pFile){
  sqlite3_uint64 tStart, tElapse;
  int rc = SQLITE_OK;
  VLogFile *p = (VLogFile *)pFile;

  tStart = vlog_time();
  if( p->pReal->pMethods ){
    rc = p->pReal->pMethods->xClose(p->pReal);
  }
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "CLOSE", -1, -1, 0, rc);
  vlogLogClose(p->pLog);
  return rc;
}

/*
** Compute signature for a block of content.
**
** For blocks of 16 or fewer bytes, the signature is just a hex dump of
** the entire block.
**
** For blocks of more than 16 bytes, the signature is a hex dump of the
** first 8 bytes followed by a 64-bit has of the entire block.
*/
static void vlogSignature(unsigned char *p, int n, char *zCksum){
  unsigned int s0 = 0, s1 = 0;
  unsigned int *pI;
  int i;
  if( n<=16 ){
    for(i=0; i<n; i++) sqlite3_snprintf(3, zCksum+i*2, "%02x", p[i]);
  }else{ 
    pI = (unsigned int*)p;
    for(i=0; i<n-7; i+=8){
      s0 += pI[0] + s1;
      s1 += pI[1] + s0;
      pI += 2;
    }
    for(i=0; i<8; i++) sqlite3_snprintf(3, zCksum+i*2, "%02x", p[i]);
    sqlite3_snprintf(18, zCksum+i*2, "-%08x%08x", s0, s1);
  }
}

/*
** Read data from an vlog-file.
*/
static int vlogRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  char zSig[40];

  tStart = vlog_time();
  rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
  tElapse = vlog_time() - tStart;
  if( rc==SQLITE_OK ){
    vlogSignature(zBuf, iAmt, zSig);
  }else{
    zSig[0] = 0;
  }
  vlogLogPrint(p->pLog, tStart, tElapse, "READ", iAmt, iOfst, zSig, rc);
  if( rc==SQLITE_OK
   && p->pLog
   && p->pLog->zFilename
   && iOfst<=24
   && iOfst+iAmt>=28
  ){
    unsigned char *x = ((unsigned char*)zBuf)+(24-iOfst);
    unsigned iCtr;
    iCtr = (x[0]<<24) + (x[1]<<16) + (x[2]<<8) + x[3];
    vlogLogPrint(p->pLog, tStart, 0, "CHNGCTR-READ", iCtr, -1, 0, 0);
  }
  return rc;
}

/*
** Write data to an vlog-file.
*/
static int vlogWrite(
  sqlite3_file *pFile,
  const void *z,
  int iAmt,
  sqlite_int64 iOfst
){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  char zSig[40];

  tStart = vlog_time();
  vlogSignature((unsigned char*)z, iAmt, zSig);
  rc = p->pReal->pMethods->xWrite(p->pReal, z, iAmt, iOfst);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "WRITE", iAmt, iOfst, zSig, rc);
  if( rc==SQLITE_OK
   && p->pLog
   && p->pLog->zFilename
   && iOfst<=24
   && iOfst+iAmt>=28
  ){
    unsigned char *x = ((unsigned char*)z)+(24-iOfst);
    unsigned iCtr;
    iCtr = (x[0]<<24) + (x[1]<<16) + (x[2]<<8) + x[3];
    vlogLogPrint(p->pLog, tStart, 0, "CHNGCTR-WRITE", iCtr, -1, 0, 0);
  }
  return rc;
}

/*
** Truncate an vlog-file.
*/
static int vlogTruncate(sqlite3_file *pFile, sqlite_int64 size){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xTruncate(p->pReal, size);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "TRUNCATE", size, -1, 0, rc);
  return rc;
}

/*
** Sync an vlog-file.
*/
static int vlogSync(sqlite3_file *pFile, int flags){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xSync(p->pReal, flags);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "SYNC", flags, -1, 0, rc);
  return rc;
}

/*
** Return the current file-size of an vlog-file.
*/
static int vlogFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "FILESIZE", *pSize, -1, 0, rc);
  return rc;
}

/*
** Lock an vlog-file.
*/
static int vlogLock(sqlite3_file *pFile, int eLock){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xLock(p->pReal, eLock);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "LOCK", eLock, -1, 0, rc);
  return rc;
}

/*
** Unlock an vlog-file.
*/
static int vlogUnlock(sqlite3_file *pFile, int eLock){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "UNLOCK", eLock, -1, 0, rc);
  return rc;
}

/*
** Check if another file-handle holds a RESERVED lock on an vlog-file.
*/
static int vlogCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "CHECKRESERVEDLOCK",
                 *pResOut, -1, "", rc);
  return rc;
}

/*
** File control method. For custom operations on an vlog-file.
*/
static int vlogFileControl(sqlite3_file *pFile, int op, void *pArg){
  VLogFile *p = (VLogFile *)pFile;
  sqlite3_uint64 tStart, tElapse;
  int rc;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
    *(char**)pArg = sqlite3_mprintf("vlog/%z", *(char**)pArg);
  }
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, -1, 0, rc);
  return rc;
}

/*
** Return the sector-size in bytes for an vlog-file.
*/
static int vlogSectorSize(sqlite3_file *pFile){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xSectorSize(p->pReal);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "SECTORSIZE", -1, -1, 0, rc);
  return rc;
}

/*
** Return the device characteristic flags supported by an vlog-file.
*/
static int vlogDeviceCharacteristics(sqlite3_file *pFile){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogFile *p = (VLogFile *)pFile;
  tStart = vlog_time();
  rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
  tElapse = vlog_time() - tStart;
  vlogLogPrint(p->pLog, tStart, tElapse, "DEVCHAR", -1, -1, 0, rc);
  return rc;
}


/*
** Open an vlog file handle.
*/
static int vlogOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  sqlite3_int64 iArg2;
  VLogFile *p = (VLogFile*)pFile;

  p->pReal = (sqlite3_file*)&p[1];
  if( (flags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_MAIN_JOURNAL))!=0 ){
    p->pLog = vlogLogOpen(zName);
  }else{
    p->pLog = 0;
  }
  tStart = vlog_time();
  rc = REALVFS(pVfs)->xOpen(REALVFS(pVfs), zName, p->pReal, flags, pOutFlags);
  tElapse = vlog_time() - tStart;
  iArg2 = pOutFlags ? *pOutFlags : -1;
  vlogLogPrint(p->pLog, tStart, tElapse, "OPEN", flags, iArg2, 0, rc);
  if( rc==SQLITE_OK ){
    pFile->pMethods = &vlog_io_methods;
  }else{
    if( p->pLog ) vlogLogClose(p->pLog);
    p->pLog = 0;
  }
  return rc;
}

/*
** Delete the file located at zPath. If the dirSync argument is true,
** ensure the file-system modifications are synced to disk before
** returning.
*/
static int vlogDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogLog *pLog;
  tStart = vlog_time();
  rc = REALVFS(pVfs)->xDelete(REALVFS(pVfs), zPath, dirSync);
  tElapse = vlog_time() - tStart;
  pLog = vlogLogOpen(zPath);
  vlogLogPrint(pLog, tStart, tElapse, "DELETE", dirSync, -1, 0, rc);
  vlogLogClose(pLog);
  return rc;
}

/*
** Test for access permissions. Return true if the requested permission
** is available, or false otherwise.
*/
static int vlogAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  int rc;
  sqlite3_uint64 tStart, tElapse;
  VLogLog *pLog;
  tStart = vlog_time();
  rc = REALVFS(pVfs)->xAccess(REALVFS(pVfs), zPath, flags, pResOut);
  tElapse = vlog_time() - tStart;
  pLog = vlogLogOpen(zPath);
  vlogLogPrint(pLog, tStart, tElapse, "ACCESS", flags, *pResOut, 0, rc);
  vlogLogClose(pLog);
  return rc;
}

/*
** Populate buffer zOut with the full canonical pathname corresponding
** to the pathname in zPath. zOut is guaranteed to point to a buffer
** of at least (INST_MAX_PATHNAME+1) bytes.
*/
static int vlogFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  return REALVFS(pVfs)->xFullPathname(REALVFS(pVfs), zPath, nOut, zOut);
}

/*
** Open the dynamic library located at zPath and return a handle.
*/
static void *vlogDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  return REALVFS(pVfs)->xDlOpen(REALVFS(pVfs), zPath);
}

/*
** Populate the buffer zErrMsg (size nByte bytes) with a human readable
** utf-8 string describing the most recent error encountered associated 
** with dynamic libraries.
*/
static void vlogDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  REALVFS(pVfs)->xDlError(REALVFS(pVfs), nByte, zErrMsg);
}

/*
** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
*/
static void (*vlogDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
  return REALVFS(pVfs)->xDlSym(REALVFS(pVfs), p, zSym);
}

/*
** Close the dynamic library handle pHandle.
*/
static void vlogDlClose(sqlite3_vfs *pVfs, void *pHandle){
  REALVFS(pVfs)->xDlClose(REALVFS(pVfs), pHandle);
}

/*
** Populate the buffer pointed to by zBufOut with nByte bytes of 
** random data.
*/
static int vlogRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  return REALVFS(pVfs)->xRandomness(REALVFS(pVfs), nByte, zBufOut);
}

/*
** Sleep for nMicro microseconds. Return the number of microseconds 
** actually slept.
*/
static int vlogSleep(sqlite3_vfs *pVfs, int nMicro){
  return REALVFS(pVfs)->xSleep(REALVFS(pVfs), nMicro);
}

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int vlogCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return REALVFS(pVfs)->xCurrentTime(REALVFS(pVfs), pTimeOut);
}

static int vlogGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return REALVFS(pVfs)->xGetLastError(REALVFS(pVfs), a, b);
}
static int vlogCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
  return REALVFS(pVfs)->xCurrentTimeInt64(REALVFS(pVfs), p);
}

/*
** Register debugvfs as the default VFS for this process.
*/
int sqlite3_register_vfslog(const char *zArg){
  vlog_vfs.pVfs = sqlite3_vfs_find(0);
  vlog_vfs.base.szOsFile = sizeof(VLogFile) + vlog_vfs.pVfs->szOsFile;
  return sqlite3_vfs_register(&vlog_vfs.base, 1);
}

  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/percentile.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \
  $(TOP)/ext/misc/wholenumber.c \
  $(TOP)/ext/misc/vfslog.c


#TESTSRC += $(TOP)/ext/fts2/fts2_tokenizer.c
#TESTSRC += $(TOP)/ext/fts3/fts3_tokenizer.c

TESTSRC2 = \
  $(TOP)/src/attach.c \

TEST_EXTENSION = $(SHPREFIX)testloadext.$(SO)
$(TEST_EXTENSION): $(TOP)/src/test_loadext.c
	$(MKSHLIB) $(TOP)/src/test_loadext.c -o $(TEST_EXTENSION)

extensiontest: testfixture$(EXE) $(TEST_EXTENSION)
	./testfixture$(EXE) $(TOP)/test/loadext.test

showdb:	$(TOP)/tool/showdb.c sqlite3.c
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showdb \
		$(TOP)/tool/showdb.c sqlite3.c

# This target will fail if the SQLite amalgamation contains any exported
# symbols that do not begin with "sqlite3_". It is run as part of the
# releasetest.tcl script.
#
checksymbols: sqlite3.o
	nm -g --defined-only sqlite3.o | grep -v " sqlite3_" ; test $$? -ne 0

	rm -f threadtest3 threadtest3.exe
	rm -f sqlite3.c fts?amal.c tclsqlite3.c
	rm -f sqlite3rc.h
	rm -f shell.c sqlite3ext.h
	rm -f sqlite3_analyzer sqlite3_analyzer.exe sqlite3_analyzer.c
	rm -f sqlite-*-output.vsix
	rm -f mptester mptester.exe
	rm -f showdb

    u8 *pSpace;                     /* Allocated space not yet assigned */
    int i;                          /* Used to iterate through p->aSample[] */

    p->iGet = -1;
    p->mxSample = mxSample;
    p->nPSample = (tRowcnt)(sqlite3_value_int64(argv[1])/(mxSample/3+1) + 1);
    p->current.anLt = &p->current.anEq[nColUp];
    p->iPrn = nCol*0x689e962d ^ sqlite3_value_int(argv[1])*0xd0944565;
  
    /* Set up the Stat4Accum.a[] and aBest[] arrays */
    p->a = (struct Stat4Sample*)&p->current.anLt[nColUp];
    p->aBest = &p->a[mxSample];
    pSpace = (u8*)(&p->a[mxSample+nCol]);
    for(i=0; i<(mxSample+nCol); i++){
      p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);

#endif

  /* Return a pointer to the allocated object to the caller */
  sqlite3_result_blob(context, p, sizeof(p), sqlite3_free);
}
static const FuncDef statInitFuncdef = {
  1+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */

  0,               /* pUserData */
  0,               /* pNext */
  statInit,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_init",     /* zName */
  0,               /* pHash */
  0                /* pDestructor */
};

#ifdef SQLITE_ENABLE_STAT4
/*
** pNew and pOld are both candidate non-periodic samples selected for 
** the same column (pNew->iCol==pOld->iCol). Ignoring this column and 
** considering only any trailing columns and the sample hash value, this
** function returns true if sample pNew is to be preferred over pOld.
** In other words, if we assume that the cardinalities of the selected
** column for pNew and pOld are equal, is pNew to be preferred over pOld.
**
** This function assumes that for each argument sample, the contents of
** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. 
*/
static int sampleIsBetterPost(
  Stat4Accum *pAccum, 
  Stat4Sample *pNew, 
  Stat4Sample *pOld
){
  int nCol = pAccum->nCol;
  int i;
  assert( pNew->iCol==pOld->iCol );
  for(i=pNew->iCol+1; i<nCol; i++){
    if( pNew->anEq[i]>pOld->anEq[i] ) return 1;
    if( pNew->anEq[i]<pOld->anEq[i] ) return 0;
  }
  if( pNew->iHash>pOld->iHash ) return 1;
  return 0;
}
#endif

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
/*
** Return true if pNew is to be preferred over pOld.
**
** This function assumes that for each argument sample, the contents of
** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. 
*/
static int sampleIsBetter(
  Stat4Accum *pAccum, 
  Stat4Sample *pNew, 
  Stat4Sample *pOld
){
  tRowcnt nEqNew = pNew->anEq[pNew->iCol];
  tRowcnt nEqOld = pOld->anEq[pOld->iCol];

  assert( pOld->isPSample==0 && pNew->isPSample==0 );
  assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) );

  if( (nEqNew>nEqOld) ) return 1;
#ifdef SQLITE_ENABLE_STAT4
  if( nEqNew==nEqOld ){
    if( pNew->iCol<pOld->iCol ) return 1;

    return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld));
  }
  return 0;
#else
  return (nEqNew==nEqOld && pNew->iHash>pOld->iHash);
#endif
}

/*
** Copy the contents of object (*pFrom) into (*pTo).
*/
void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){
  pTo->iRowid = pFrom->iRowid;

/*
** Copy the contents of sample *pNew into the p->a[] array. If necessary,
** remove the least desirable sample from p->a[] to make room.
*/
static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){
  Stat4Sample *pSample;
  int i;



  assert( IsStat4 || nEqZero==0 );

#ifdef SQLITE_ENABLE_STAT4
  if( pNew->isPSample==0 ){
    Stat4Sample *pUpgrade = 0;
    assert( pNew->anEq[pNew->iCol]>0 );

    /* This sample is being added because the prefix that ends in column 
    ** iCol occurs many times in the table. However, if we have already
    ** added a sample that shares this prefix, there is no need to add
    ** this one. Instead, upgrade the priority of the highest priority
    ** existing sample that shares this prefix.  */
    for(i=p->nSample-1; i>=0; i--){
      Stat4Sample *pOld = &p->a[i];
      if( pOld->anEq[pNew->iCol]==0 ){
        if( pOld->isPSample ) return;
        assert( pOld->iCol>pNew->iCol );
        assert( sampleIsBetter(p, pNew, pOld) );
        if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){
          pUpgrade = pOld;
        }
      }
    }
    if( pUpgrade ){
      pUpgrade->iCol = pNew->iCol;
      pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol];
      goto find_new_min;
    }
  }
#endif

  /* If necessary, remove sample iMin to make room for the new sample. */
  if( p->nSample>=p->mxSample ){
    Stat4Sample *pMin = &p->a[p->iMin];
    tRowcnt *anEq = pMin->anEq;
    tRowcnt *anLt = pMin->anLt;
    tRowcnt *anDLt = pMin->anDLt;

       || pNew->anLt[p->nCol-1] > p->a[p->nSample-1].anLt[p->nCol-1] );
#endif

  /* Insert the new sample */
  pSample = &p->a[p->nSample];
  sampleCopy(p, pSample, pNew);
  p->nSample++;




















  /* Zero the first nEqZero entries in the anEq[] array. */
  memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero);

#ifdef SQLITE_ENABLE_STAT4
 find_new_min:
#endif
  if( p->nSample>=p->mxSample ){
    int iMin = -1;
    for(i=0; i<p->mxSample; i++){
      if( p->a[i].isPSample ) continue;
      if( iMin<0 || sampleIsBetter(p, &p->a[iMin], &p->a[i]) ){
        iMin = i;
      }
    }
    assert( iMin>=0 );
    p->iMin = iMin;
  }
}

#ifdef SQLITE_ENABLE_STAT4
  int i;

  /* Check if any samples from the aBest[] array should be pushed
  ** into IndexSample.a[] at this point.  */
  for(i=(p->nCol-2); i>=iChng; i--){
    Stat4Sample *pBest = &p->aBest[i];
    pBest->anEq[i] = p->current.anEq[i];
    if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){


      sampleInsert(p, pBest, i);
    }
  }

  /* Update the anEq[] fields of any samples already collected. */
  for(i=p->nSample-1; i>=0; i--){
    int j;

    if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){
      p->current.isPSample = 1;
      sampleInsert(p, &p->current, 0);
      p->current.isPSample = 0;
    }else 

    /* Or if it is a non-periodic sample. Add it in this case too. */
    if( p->nSample<p->mxSample 
     || sampleIsBetter(p, &p->current, &p->a[p->iMin]) 
    ){
      sampleInsert(p, &p->current, 0);
    }
  }
#endif
}

/*

      sampleInsert(p, &p->current, p->nCol-1);
      p->current.isPSample = 0;
    }

    /* Update the aBest[] array. */
    for(i=0; i<(p->nCol-1); i++){
      p->current.iCol = i;
      if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){
        sampleCopy(p, &p->aBest[i], &p->current);
      }
    }
  }
#endif
}
static const FuncDef statPushFuncdef = {
  2+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */

  0,               /* pUserData */
  0,               /* pNext */
  statPush,        /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_push",     /* zName */
  0,               /* pHash */

    char *zRet = sqlite3MallocZero(p->nCol * 25);
    if( zRet==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }

    sqlite3_snprintf(24, zRet, "%llu", (u64)p->nRow);
    z = zRet + sqlite3Strlen30(zRet);
    for(i=0; i<(p->nCol-1); i++){
      u64 nDistinct = p->current.anDLt[i] + 1;
      u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
      sqlite3_snprintf(24, z, " %llu", iVal);
      z += sqlite3Strlen30(z);
      assert( p->current.anEq[i] );
    }
    assert( z[0]=='\0' && z>zRet );

    sqlite3_result_text(context, zRet, -1, sqlite3_free);
  }

      char *zRet = sqlite3MallocZero(p->nCol * 25);
      if( zRet==0 ){
        sqlite3_result_error_nomem(context);
      }else{
        int i;
        char *z = zRet;
        for(i=0; i<p->nCol; i++){
          sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]);
          z += sqlite3Strlen30(z);
        }
        assert( z[0]=='\0' && z>zRet );
        z[-1] = '\0';
        sqlite3_result_text(context, zRet, -1, sqlite3_free);
      }
    }
  }
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
}
static const FuncDef statGetFuncdef = {
  1+IsStat34,      /* nArg */
  SQLITE_UTF8,     /* funcFlags */

  0,               /* pUserData */
  0,               /* pNext */
  statGet,         /* xFunc */
  0,               /* xStep */
  0,               /* xFinalize */
  "stat_get",      /* zName */
  0,               /* pHash */

/*
** The first argument points to a nul-terminated string containing a
** list of space separated integers. Read the first nOut of these into
** the array aOut[].
*/
static void decodeIntArray(
  char *zIntArray,       /* String containing int array to decode */
  int nOut,              /* Number of slots in aOut[] */
  tRowcnt *aOut,         /* Store integers here */
  Index *pIndex          /* Handle extra flags for this index, if not NULL */
){
  char *z = zIntArray;
  int c;
  int i;
  tRowcnt v;



#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( z==0 ) z = "";
#else
  if( NEVER(z==0) ) z = "";
#endif
  for(i=0; *z && i<nOut; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
    aOut[i] = v;
    if( *z==' ' ) z++;
  }
#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
  assert( pIndex!=0 );
#else
  if( pIndex )
#endif
  {
    if( strcmp(z, "unordered")==0 ){
      pIndex->bUnordered = 1;
    }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
      int v32 = 0;
      sqlite3GetInt32(z+3, &v32);
      pIndex->szIdxRow = sqlite3LogEst(v32);
    }
  }
}

/*
** This callback is invoked once for each index when reading the
** sqlite_stat1 table.  
**

    pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
  }else{
    pIndex = 0;
  }
  z = argv[2];

  if( pIndex ){

    decodeIntArray((char*)z, pIndex->nColumn+1, pIndex->aiRowEst, pIndex);
    if( pIndex->pPartIdxWhere==0 ) pTable->nRowEst = pIndex->aiRowEst[0];

  }else{
    Index fakeIdx;
    fakeIdx.szIdxRow = pTable->szTabRow;
    decodeIntArray((char*)z, 1, &pTable->nRowEst, &fakeIdx);
    pTable->szTabRow = fakeIdx.szIdxRow;
  }

  return 0;
}

/*
** If the Index.aSample variable is not NULL, delete the aSample[] array

** Called by the parser to compile a DETACH statement.
**
**     DETACH pDbname
*/
void sqlite3Detach(Parse *pParse, Expr *pDbname){
  static const FuncDef detach_func = {
    1,                /* nArg */
    SQLITE_UTF8,      /* funcFlags */

    0,                /* pUserData */
    0,                /* pNext */
    detachFunc,       /* xFunc */
    0,                /* xStep */
    0,                /* xFinalize */
    "sqlite_detach",  /* zName */
    0,                /* pHash */
    0                 /* pDestructor */
  };
  codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
}

/*
** Called by the parser to compile an ATTACH statement.
**
**     ATTACH p AS pDbname KEY pKey
*/
void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
  static const FuncDef attach_func = {
    3,                /* nArg */
    SQLITE_UTF8,      /* funcFlags */

    0,                /* pUserData */
    0,                /* pNext */
    attachFunc,       /* xFunc */
    0,                /* xStep */
    0,                /* xFinalize */
    "sqlite_attach",  /* zName */
    0,                /* pHash */
    0                 /* pDestructor */
  };
  codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
}
#endif /* SQLITE_OMIT_ATTACH */

/*
** Initialize a DbFixer structure.  This routine must be called prior
** to passing the structure to one of the sqliteFixAAAA() routines below.



*/
void sqlite3FixInit(
  DbFixer *pFix,      /* The fixer to be initialized */
  Parse *pParse,      /* Error messages will be written here */
  int iDb,            /* This is the database that must be used */
  const char *zType,  /* "view", "trigger", or "index" */
  const Token *pName  /* Name of the view, trigger, or index */
){
  sqlite3 *db;


  db = pParse->db;
  assert( db->nDb>iDb );
  pFix->pParse = pParse;
  pFix->zDb = db->aDb[iDb].zName;
  pFix->pSchema = db->aDb[iDb].pSchema;
  pFix->zType = zType;
  pFix->pName = pName;
  pFix->bVarOnly = (iDb==1);
}

/*
** The following set of routines walk through the parse tree and assign
** a specific database to all table references where the database name
** was left unspecified in the original SQL statement.  The pFix structure
** must have been initialized by a prior call to sqlite3FixInit().

  int i;
  const char *zDb;
  struct SrcList_item *pItem;

  if( NEVER(pList==0) ) return 0;
  zDb = pFix->zDb;
  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pFix->bVarOnly==0 ){
      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
  }
  return 0;
}

      return 1;
    }
    if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
      return 1;
    }
    if( sqlite3FixExprList(pFix, pSelect->pGroupBy) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
      return 1;
    }
    if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pOffset) ){
      return 1;
    }
    pSelect = pSelect->pPrior;
  }
  return 0;
}
int sqlite3FixExpr(
  DbFixer *pFix,     /* Context of the fixation */
  Expr *pExpr        /* The expression to be fixed to one database */
){
  while( pExpr ){
    if( pExpr->op==TK_VARIABLE ){
      if( pFix->pParse->db->init.busy ){
        pExpr->op = TK_NULL;
      }else{
        sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType);
        return 1;
      }
    }
    if( ExprHasProperty(pExpr, EP_TokenOnly) ) break;
    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
      if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;
    }else{
      if( sqlite3FixExprList(pFix, pExpr->x.pList) ) return 1;
    }
    if( sqlite3FixExpr(pFix, pExpr->pRight) ){
      return 1;

    pBt->max1bytePayload = 127;
  }else{
    pBt->max1bytePayload = (u8)pBt->maxLocal;
  }
  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;
  pBt->nPage = nPage;

  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;
  return rc;
}

  /* If the btree is already in a write-transaction, or it
  ** is already in a read-transaction and a read-transaction
  ** is requested, this is a no-op.
  */
  if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){
    goto trans_begun;
  }
  assert( pBt->inTransaction==TRANS_WRITE || IfNotOmitAV(pBt->bDoTruncate)==0 );

  /* Write transactions are not possible on a read-only database */
  if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){
    rc = SQLITE_READONLY;
    goto trans_begun;
  }

**
** The first page is always a btree page.  The first 100 bytes of the first
** page contain a special header (the "file header") that describes the file.
** The format of the file header is as follows:
**
**   OFFSET   SIZE    DESCRIPTION
**      0      16     Header string: "SQLite format 3\000"
**     16       2     Page size in bytes.  (1 means 65536)
**     18       1     File format write version
**     19       1     File format read version
**     20       1     Bytes of unused space at the end of each page
**     21       1     Max embedded payload fraction (must be 64)
**     22       1     Min embedded payload fraction (must be 32)
**     23       1     Min leaf payload fraction (must be 32)
**     24       4     File change counter
**     28       4     Reserved for future use
**     32       4     First freelist page
**     36       4     Number of freelist pages in the file
**     40      60     15 4-byte meta values passed to higher layers
**
**     40       4     Schema cookie
**     44       4     File format of schema layer
**     48       4     Size of page cache
**     52       4     Largest root-page (auto/incr_vacuum)
**     56       4     1=UTF-8 2=UTF16le 3=UTF16be
**     60       4     User version
**     64       4     Incremental vacuum mode
**     68       4     Application-ID
**     72      20     unused
**     92       4     The version-valid-for number
**     96       4     SQLITE_VERSION_NUMBER
**
** All of the integer values are big-endian (most significant byte first).
**
** The file change counter is incremented when the database is changed
** This counter allows other processes to know when the file has changed
** and thus when they need to flush their cache.
**

    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
  pTable->iPKey = -1;
  pTable->pSchema = db->aDb[iDb].pSchema;
  pTable->nRef = 1;
  pTable->nRowEst = 1048576;
  assert( pParse->pNewTable==0 );
  pParse->pNewTable = pTable;

  /* If this is the magic sqlite_sequence table used by autoincrement,
  ** then record a pointer to this table in the main database structure
  ** so that INSERT can find the table easily.
  */

  pCol->zName = z;
 
  /* If there is no type specified, columns have the default affinity
  ** 'NONE'. If there is a type specified, then sqlite3AddColumnType() will
  ** be called next to set pCol->affinity correctly.
  */
  pCol->affinity = SQLITE_AFF_NONE;
  pCol->szEst = 1;
  p->nCol++;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has
** been seen on a column.  This routine sets the notNull flag on

** 'REAL'        | SQLITE_AFF_REAL
** 'FLOA'        | SQLITE_AFF_REAL
** 'DOUB'        | SQLITE_AFF_REAL
**
** If none of the substrings in the above table are found,
** SQLITE_AFF_NUMERIC is returned.
*/
char sqlite3AffinityType(const char *zIn, u8 *pszEst){
  u32 h = 0;
  char aff = SQLITE_AFF_NUMERIC;
  const char *zChar = 0;

  if( zIn==0 ) return aff;
  while( zIn[0] ){
    h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];
    zIn++;
    if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */
      aff = SQLITE_AFF_TEXT;
      zChar = zIn;
    }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */
      aff = SQLITE_AFF_TEXT;
    }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */
        && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
      aff = SQLITE_AFF_NONE;
      if( zIn[0]=='(' ) zChar = zIn;
#ifndef SQLITE_OMIT_FLOATING_POINT
    }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
    }else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a')          /* FLOA */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
    }else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b')          /* DOUB */
        && aff==SQLITE_AFF_NUMERIC ){
      aff = SQLITE_AFF_REAL;
#endif
    }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */
      aff = SQLITE_AFF_INTEGER;
      break;
    }
  }

  /* If pszEst is not NULL, store an estimate of the field size.  The
  ** estimate is scaled so that the size of an integer is 1.  */
  if( pszEst ){
    *pszEst = 1;   /* default size is approx 4 bytes */
    if( aff<=SQLITE_AFF_NONE ){
      if( zChar ){
        while( zChar[0] ){
          if( sqlite3Isdigit(zChar[0]) ){
            int v;
            sqlite3GetInt32(zChar, &v);
            v = v/4 + 1;
            if( v>255 ) v = 255;
            *pszEst = v; /* BLOB(k), VARCHAR(k), CHAR(k) -> r=(k/4+1) */
            break;
          }
          zChar++;
        }
      }else{
        *pszEst = 5;   /* BLOB, TEXT, CLOB -> r=5  (approx 20 bytes)*/
      }
    }
  }
  return aff;
}

/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.  The pFirst token is the first
** token in the sequence of tokens that describe the type of the

  Column *pCol;

  p = pParse->pNewTable;
  if( p==0 || NEVER(p->nCol<1) ) return;
  pCol = &p->aCol[p->nCol-1];
  assert( pCol->zType==0 );
  pCol->zType = sqlite3NameFromToken(pParse->db, pType);
  pCol->affinity = sqlite3AffinityType(pCol->zType, &pCol->szEst);
}

/*
** The expression is the default value for the most recently added column
** of the table currently under construction.
**
** Default value expressions must be constant.  Raise an exception if this

    testcase( pCol->affinity==SQLITE_AFF_NUMERIC );
    testcase( pCol->affinity==SQLITE_AFF_INTEGER );
    testcase( pCol->affinity==SQLITE_AFF_REAL );
    
    zType = azType[pCol->affinity - SQLITE_AFF_TEXT];
    len = sqlite3Strlen30(zType);
    assert( pCol->affinity==SQLITE_AFF_NONE 
            || pCol->affinity==sqlite3AffinityType(zType, 0) );
    memcpy(&zStmt[k], zType, len);
    k += len;
    assert( k<=n );
  }
  sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd);
  return zStmt;
}

/*
** Estimate the total row width for a table.
*/
static void estimateTableWidth(Table *pTab){
  unsigned wTable = 0;
  const Column *pTabCol;
  int i;
  for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){
    wTable += pTabCol->szEst;
  }
  if( pTab->iPKey<0 ) wTable++;
  pTab->szTabRow = sqlite3LogEst(wTable*4);
}

/*
** Estimate the average size of a row for an index.
*/
static void estimateIndexWidth(Index *pIdx){
  unsigned wIndex = 1;
  int i;
  const Column *aCol = pIdx->pTable->aCol;
  for(i=0; i<pIdx->nColumn; i++){
    assert( pIdx->aiColumn[i]>=0 && pIdx->aiColumn[i]<pIdx->pTable->nCol );
    wIndex += aCol[pIdx->aiColumn[i]].szEst;
  }
  pIdx->szIdxRow = sqlite3LogEst(wIndex*4);
}

/*
** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure that other action routines have been building
** is added to the internal hash tables, assuming no errors have

*/
void sqlite3EndTable(
  Parse *pParse,          /* Parse context */
  Token *pCons,           /* The ',' token after the last column defn. */
  Token *pEnd,            /* The final ')' token in the CREATE TABLE */
  Select *pSelect         /* Select from a "CREATE ... AS SELECT" */
){
  Table *p;                 /* The new table */
  sqlite3 *db = pParse->db; /* The database connection */
  int iDb;                  /* Database in which the table lives */
  Index *pIdx;              /* An implied index of the table */

  if( (pEnd==0 && pSelect==0) || db->mallocFailed ){
    return;
  }
  p = pParse->pNewTable;
  if( p==0 ) return;

  assert( !db->init.busy || !pSelect );

  iDb = sqlite3SchemaToIndex(db, p->pSchema);

#ifndef SQLITE_OMIT_CHECK
  /* Resolve names in all CHECK constraint expressions.
  */
  if( p->pCheck ){
    sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* Estimate the average row size for the table and for all implied indices */
  estimateTableWidth(p);
  for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
    estimateIndexWidth(pIdx);
  }

  /* If the db->init.busy is 1 it means we are reading the SQL off the
  ** "sqlite_master" or "sqlite_temp_master" table on the disk.
  ** So do not write to the disk again.  Extract the root page number
  ** for the table from the db->init.newTnum field.  (The page number
  ** should have been put there by the sqliteOpenCb routine.)
  */

  p = pParse->pNewTable;
  if( p==0 || pParse->nErr ){
    sqlite3SelectDelete(db, pSelect);
    return;
  }
  sqlite3TwoPartName(pParse, pName1, pName2, &pName);
  iDb = sqlite3SchemaToIndex(db, p->pSchema);
  sqlite3FixInit(&sFix, pParse, iDb, "view", pName);
  if( sqlite3FixSelect(&sFix, pSelect) ){

    sqlite3SelectDelete(db, pSelect);
    return;
  }

  /* Make a copy of the entire SELECT statement that defines the view.
  ** This will force all the Expr.token.z values to be dynamically
  ** allocated rather than point to the input string - which means that

  DbFixer sFix;        /* For assigning database names to pTable */
  int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */
  sqlite3 *db = pParse->db;
  Db *pDb;             /* The specific table containing the indexed database */
  int iDb;             /* Index of the database that is being written */
  Token *pName = 0;    /* Unqualified name of the index to create */
  struct ExprList_item *pListItem; /* For looping over pList */
  const Column *pTabCol;           /* A column in the table */
  int nCol;                        /* Number of columns */
  int nExtra = 0;                  /* Space allocated for zExtra[] */
  char *zExtra;                    /* Extra space after the Index object */

  assert( pParse->nErr==0 );      /* Never called with prior errors */
  if( db->mallocFailed || IN_DECLARE_VTAB ){
    goto exit_create_index;
  }
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto exit_create_index;

      pTab = sqlite3SrcListLookup(pParse, pTblName);
      if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
        iDb = 1;
      }
    }
#endif

    sqlite3FixInit(&sFix, pParse, iDb, "index", pName);
    if( sqlite3FixSrcList(&sFix, pTblName) ){

      /* Because the parser constructs pTblName from a single identifier,
      ** sqlite3FixSrcList can never fail. */
      assert(0);
    }
    pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);
    assert( db->mallocFailed==0 || pTab==0 );
    if( pTab==0 ) goto exit_create_index;

  ** more than once within the same index.  Only the first instance of
  ** the column will ever be used by the optimizer.  Note that using the
  ** 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;

    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 ){

    }
    pIndex->azColl[i] = zColl;
    requestedSortOrder = pListItem->sortOrder & sortOrderMask;
    pIndex->aSortOrder[i] = (u8)requestedSortOrder;
    if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0;
  }
  sqlite3DefaultRowEst(pIndex);
  if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);

  if( pTab==pParse->pNewTable ){
    /* This routine has been called to create an automatic index as a
    ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
    ** a PRIMARY KEY or UNIQUE clause following the column definitions.
    ** i.e. one of:
    **

  if( p->nArg==nArg ){
    match = 4;
  }else{
    match = 1;
  }

  /* Bonus points if the text encoding matches */
  if( enc==(p->funcFlags & SQLITE_FUNC_ENCMASK) ){
    match += 2;  /* Exact encoding match */
  }else if( (enc & p->funcFlags & 2)!=0 ){
    match += 1;  /* Both are UTF16, but with different byte orders */
  }

  return match;
}

/*

  ** exact match for the name, number of arguments and encoding, then add a
  ** new entry to the hash table and return it.
  */
  if( createFlag && bestScore<FUNC_PERFECT_MATCH && 
      (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
    pBest->zName = (char *)&pBest[1];
    pBest->nArg = (u16)nArg;
    pBest->funcFlags = enc;
    memcpy(pBest->zName, zName, nName);
    pBest->zName[nName] = 0;
    sqlite3FuncDefInsert(&db->aFunc, pBest);
  }

  if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
    return pBest;

/*
** Set the time to the current time reported by the VFS.
**
** Return the number of errors.
*/
static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
  p->iJD = sqlite3StmtCurrentTime(context);
  if( p->iJD>0 ){
    p->validJD = 1;
    return 0;
  }else{
    return 1;
  }
}

  struct tm *pTm;
  struct tm sNow;
  char zBuf[20];

  UNUSED_PARAMETER(argc);
  UNUSED_PARAMETER(argv);

  iT = sqlite3StmtCurrentTime(context);
  if( iT<=0 ) return;
  t = iT/1000 - 10000*(sqlite3_int64)21086676;
#ifdef HAVE_GMTIME_R
  pTm = gmtime_r(&t, &sNow);
#else
  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
  pTm = gmtime(&t);
  if( pTm ) memcpy(&sNow, pTm, sizeof(sNow));

   && !IsVirtual(pTab) 
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
   && db->xPreUpdateCallback==0
#endif
   && 0==sqlite3FkRequired(pParse, pTab, 0, 0)
  ){
    assert( !isView );
    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
    sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt,
                      pTab->zName, P4_STATIC);
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
    }
  }else

    ** being deleted. Do not attempt to delete the row a second time, and 
    ** do not fire AFTER triggers.  */
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid);

    /* Do FK processing. This call checks that any FK constraints that
    ** refer to this table (i.e. constraints attached to other tables) 
    ** are not violated by deleting this row.  */
    sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
  }

  /* Delete the index and table entries. Skip this step if pTab is really
  ** a view (in which case the only effect of the DELETE statement is to
  ** fire the INSTEAD OF triggers).  
  **
  ** If variable 'count' is non-zero, then this OP_Delete instruction should

    sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
    sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE);
  }

  /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
  ** handle rows (possibly in other tables) that refer via a foreign key
  ** to the row just deleted. */ 
  sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);

  /* Invoke AFTER DELETE trigger programs. */
  sqlite3CodeRowTrigger(pParse, pTrigger, 
      TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel
  );

  /* Jump here if the row had already been deleted before any BEFORE

  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) );
    return sqlite3AffinityType(pExpr->u.zToken, 0);
  }
#endif
  if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER) 
   && pExpr->pTab!=0
  ){
    /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
    ** a TK_COLUMN but was previously evaluated and cached in a register */

** 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|EP_Skip;
      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 or TK_AS operators and any unlikely()
** or likelihood() function at the root of an expression.
*/
Expr *sqlite3ExprSkipCollate(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
    if( ExprHasProperty(pExpr, EP_Unlikely) ){
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      assert( pExpr->x.pList->nExpr>0 );
      assert( pExpr->op==TK_FUNCTION );
      pExpr = pExpr->x.pList->a[0].pExpr;
    }else{
      assert( 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.
**

** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  const char *z;

  if( pExpr==0 ) return;
  assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
  z = pExpr->u.zToken;
  assert( z!=0 );
  assert( z[0]!=0 );
  if( z[1]==0 ){
    /* Wildcard of the form "?".  Assign the next variable number */
    assert( z[0]=='?' );
    pExpr->iColumn = (ynVar)(++pParse->nVar);

/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(sqlite3 *db, Expr *p){
  if( p==0 ) return;
  /* Sanity check: Assert that the IntValue is non-negative if it exists */
  assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
  if( !ExprHasProperty(p, EP_TokenOnly) ){
    /* The Expr.x union is never used at the same time as Expr.pRight */
    assert( p->x.pList==0 || p->pRight==0 );
    sqlite3ExprDelete(db, p->pLeft);
    sqlite3ExprDelete(db, p->pRight);

    if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);

    if( ExprHasProperty(p, EP_xIsSelect) ){
      sqlite3SelectDelete(db, p->x.pSelect);
    }else{
      sqlite3ExprListDelete(db, p->x.pList);
    }
  }
  if( !ExprHasProperty(p, EP_Static) ){

** to reduce a pristine expression tree from the parser.  The implementation
** of dupedExprStructSize() contain multiple assert() statements that attempt
** to enforce this constraint.
*/
static int dupedExprStructSize(Expr *p, int flags){
  int nSize;
  assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
  assert( EXPR_FULLSIZE<=0xfff );
  assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
  if( 0==(flags&EXPRDUP_REDUCE) ){
    nSize = EXPR_FULLSIZE;
  }else{
    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
    assert( !ExprHasProperty(p, EP_FromJoin) ); 
    assert( !ExprHasProperty(p, EP_MemToken) );
    assert( !ExprHasProperty(p, EP_NoReduce) );
    if( p->pLeft || p->x.pList ){
      nSize = EXPR_REDUCEDSIZE | EP_Reduced;
    }else{
      assert( p->pRight==0 );
      nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
    }
  }
  return nSize;
}

/*

      }else{
        int nSize = exprStructSize(p);
        memcpy(zAlloc, p, nSize);
        memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
      }

      /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
      pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);
      pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
      pNew->flags |= staticFlag;

      /* Copy the p->u.zToken string, if any. */
      if( nToken ){
        char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
        memcpy(zToken, p->u.zToken, nToken);
      }

      if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
        /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
        if( ExprHasProperty(p, EP_xIsSelect) ){
          pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
        }else{
          pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
        }
      }

      /* Fill in pNew->pLeft and pNew->pRight. */
      if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
        zAlloc += dupedExprNodeSize(p, flags);
        if( ExprHasProperty(pNew, EP_Reduced) ){
          pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
          pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
        }
        if( pzBuffer ){
          *pzBuffer = zAlloc;
        }
      }else{

        if( !ExprHasProperty(p, EP_TokenOnly) ){
          pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
          pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
        }
      }

    }
  }

**
*/
static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){

  /* If pWalker->u.i is 3 then any term of the expression that comes from
  ** the ON or USING clauses of a join disqualifies the expression
  ** from being considered constant. */
  if( pWalker->u.i==3 && ExprHasProperty(pExpr, EP_FromJoin) ){
    pWalker->u.i = 0;
    return WRC_Abort;
  }

  switch( pExpr->op ){
    /* Consider functions to be constant if all their arguments are constant
    ** and pWalker->u.i==2 */

    eType = IN_INDEX_EPH;
    if( prNotFound ){
      *prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{
      testcase( pParse->nQueryLoop>0 );
      pParse->nQueryLoop = 0;
      if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
        eType = IN_INDEX_ROWID;
      }
    }
    sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;
  }else{
    pX->iTable = iTab;

  **    *  The right-hand side is a correlated subquery
  **    *  The right-hand side is an expression list containing variables
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasProperty(pExpr, EP_VarSelect) ){
    testAddr = sqlite3CodeOnce(pParse);
  }

#ifndef SQLITE_OMIT_EXPLAIN
  if( pParse->explain==2 ){
    char *zMsg = sqlite3MPrintf(
        pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ",

      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
                                  &sqlite3IntTokens[1]);
      pSel->iLimit = 0;
      if( sqlite3Select(pParse, pSel, &dest) ){
        return 0;
      }
      rReg = dest.iSDParm;
      ExprSetVVAProperty(pExpr, EP_NoReduce);
      break;
    }
  }

  if( testAddr>=0 ){
    sqlite3VdbeJumpHere(v, testAddr);
  }

  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    int r = p->iReg;
    if( r>=iFrom && r<=iTo ) return 1;    /*NO_TEST*/
  }
  return 0;
}
#endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */

/*
** Convert an expression node to a TK_REGISTER
*/
static void exprToRegister(Expr *p, int iReg){
  p->op2 = p->op;
  p->op = TK_REGISTER;
  p->iTable = iReg;
  ExprClearProperty(p, EP_Skip);
}

/*
** Generate code into the current Vdbe to evaluate the given
** expression.  Attempt to store the results in register "target".
** Return the register where results are stored.
**
** With this routine, there is no guarantee that results will

    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      int aff, to_op;
      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      aff = sqlite3AffinityType(pExpr->u.zToken, 0);
      to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
      assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
      assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
      assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
      assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
      assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
      testcase( to_op==OP_ToText );

      int i;                 /* Loop counter */
      u8 enc = ENC(db);      /* The text encoding used by this database */
      CollSeq *pColl = 0;    /* A collating sequence */

      assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
      testcase( op==TK_CONST_FUNC );
      testcase( op==TK_FUNCTION );
      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
        pFarg = 0;
      }else{
        pFarg = pExpr->x.pList;
      }
      nFarg = pFarg ? pFarg->nExpr : 0;
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      zId = pExpr->u.zToken;
      nId = sqlite3Strlen30(zId);
      pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
      if( pDef==0 ){
        sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
        break;
      }

      /* Attempt a direct implementation of the built-in COALESCE() and
      ** IFNULL() functions.  This avoids unnecessary evalation of
      ** arguments past the first non-NULL argument.
      */
      if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
        int endCoalesce = sqlite3VdbeMakeLabel(v);
        assert( nFarg>=2 );
        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
        for(i=1; i<nFarg; i++){
          sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
          sqlite3ExprCacheRemove(pParse, target, 1);
          sqlite3ExprCachePush(pParse);
          sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
          sqlite3ExprCachePop(pParse, 1);
        }
        sqlite3VdbeResolveLabel(v, endCoalesce);
        break;
      }

      /* The UNLIKELY() function is a no-op.  The result is the value
      ** of the first argument.
      */
      if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
        assert( nFarg>=1 );
        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
        break;
      }

      if( pFarg ){
        r1 = sqlite3GetTempRange(pParse, nFarg);

        /* For length() and typeof() functions with a column argument,
        ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
        ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
        ** loading.
        */
        if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
          u8 exprOp;
          assert( nFarg==1 );
          assert( pFarg->a[0].pExpr!=0 );
          exprOp = pFarg->a[0].pExpr->op;
          if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
            assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
            assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
            testcase( (pDef->funcFlags&~SQLITE_FUNC_ENCMASK)
                       ==SQLITE_FUNC_LENGTH );
            pFarg->a[0].pExpr->op2 = pDef->funcFlags&~SQLITE_FUNC_ENCMASK;
          }
        }

        sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
        sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
        sqlite3ExprCachePop(pParse, 1);   /* Ticket 2ea2425d34be */
      }else{

        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
      }
#endif
      for(i=0; i<nFarg; i++){
        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
          constMask |= (1<<i);
        }
        if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
        }
      }
      if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
        if( !pColl ) pColl = db->pDfltColl; 
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
      }
      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
                        (char*)pDef, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nFarg);
      if( nFarg ){

    **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
    **
    ** Form A is can be transformed into the equivalent form B as follows:
    **   CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
    **        WHEN x=eN THEN rN ELSE y END
    **
    ** X (if it exists) is in pExpr->pLeft.
    ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
    ** odd.  The Y is also optional.  If the number of elements in x.pList
    ** is even, then Y is omitted and the "otherwise" result is NULL.

    ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
    **
    ** The result of the expression is the Ri for the first matching Ei,
    ** or if there is no matching Ei, the ELSE term Y, or if there is
    ** no ELSE term, NULL.
    */
    default: assert( op==TK_CASE ); {
      int endLabel;                     /* GOTO label for end of CASE stmt */
      int nextCase;                     /* GOTO label for next WHEN clause */
      int nExpr;                        /* 2x number of WHEN terms */
      int i;                            /* Loop counter */
      ExprList *pEList;                 /* List of WHEN terms */
      struct ExprList_item *aListelem;  /* Array of WHEN terms */
      Expr opCompare;                   /* The X==Ei expression */
      Expr cacheX;                      /* Cached expression X */
      Expr *pX;                         /* The X expression */
      Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */
      VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )

      assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );

      assert(pExpr->x.pList->nExpr > 0);
      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      if( (pX = pExpr->pLeft)!=0 ){
        cacheX = *pX;
        testcase( pX->op==TK_COLUMN );
        testcase( pX->op==TK_REGISTER );
        exprToRegister(&cacheX, sqlite3ExprCodeTemp(pParse, pX, &regFree1));
        testcase( regFree1==0 );

        opCompare.op = TK_EQ;
        opCompare.pLeft = &cacheX;
        pTest = &opCompare;
        /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
        ** The value in regFree1 might get SCopy-ed into the file result.
        ** So make sure that the regFree1 register is not reused for other
        ** purposes and possibly overwritten.  */
        regFree1 = 0;
      }
      for(i=0; i<nExpr-1; i=i+2){
        sqlite3ExprCachePush(pParse);
        if( pX ){
          assert( pTest!=0 );
          opCompare.pRight = aListelem[i].pExpr;
        }else{
          pTest = aListelem[i].pExpr;
        }
        nextCase = sqlite3VdbeMakeLabel(v);
        testcase( pTest->op==TK_COLUMN );
        sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
        testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
        testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
        sqlite3ExprCachePop(pParse, 1);
        sqlite3VdbeResolveLabel(v, nextCase);
      }
      if( (nExpr&1)!=0 ){
        sqlite3ExprCachePush(pParse);
        sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);
        sqlite3ExprCachePop(pParse, 1);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
      }
      assert( db->mallocFailed || pParse->nErr>0 
           || pParse->iCacheLevel==iCacheLevel );
      sqlite3VdbeResolveLabel(v, endLabel);

  ** no way for a TK_REGISTER to exist here.  But it seems prudent to
  ** keep the ALWAYS() in case the conditions above change with future
  ** modifications or enhancements. */
  if( ALWAYS(pExpr->op!=TK_REGISTER) ){  
    int iMem;
    iMem = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
    exprToRegister(pExpr, iMem);


  }
  return inReg;
}

#if defined(SQLITE_ENABLE_TREE_EXPLAIN)
/*
** Generate a human-readable explanation of an expression tree.

      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      break;
    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      const char *zAff = "unk";
      switch( sqlite3AffinityType(pExpr->u.zToken, 0) ){
        case SQLITE_AFF_TEXT:    zAff = "TEXT";     break;
        case SQLITE_AFF_NONE:    zAff = "NONE";     break;
        case SQLITE_AFF_NUMERIC: zAff = "NUMERIC";  break;
        case SQLITE_AFF_INTEGER: zAff = "INTEGER";  break;
        case SQLITE_AFF_REAL:    zAff = "REAL";     break;
      }
      sqlite3ExplainPrintf(pOut, "CAST-%s(", zAff);

      break;
    }

    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pFarg;       /* List of function arguments */
      if( ExprHasProperty(pExpr, EP_TokenOnly) ){
        pFarg = 0;
      }else{
        pFarg = pExpr->x.pList;
      }
      if( op==TK_AGG_FUNCTION ){
        sqlite3ExplainPrintf(pOut, "AGG_FUNCTION%d:%s(",
                             pExpr->op2, pExpr->u.zToken);

  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 );


    exprToRegister(pExpr, r2);
    return WRC_Prune;
  }
  return WRC_Continue;
}

/*
** Preevaluate constant subexpressions within pExpr and store the

  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;
  compRight.pLeft = &exprX;
  compRight.pRight = pExpr->x.pList->a[1].pExpr;
  exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, &regFree1));


  if( jumpIfTrue ){
    sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
  }else{
    sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
  }
  sqlite3ReleaseTempReg(pParse, regFree1);

** just might result in some slightly slower code.  But returning
** an incorrect 0 or 1 could lead to a malfunction.
*/
int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
  if( pA==0||pB==0 ){
    return pB==pA ? 0 : 2;
  }
  assert( !ExprHasProperty(pA, EP_TokenOnly|EP_Reduced) );
  assert( !ExprHasProperty(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 && (pA->op!=TK_REGISTER || pA->op2!=pB->op) ){
    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
      return 1;

      testcase( pExpr->op==TK_COLUMN );
      /* Check to see if the column is in one of the tables in the FROM
      ** clause of the aggregate query */
      if( ALWAYS(pSrcList!=0) ){
        struct SrcList_item *pItem = pSrcList->a;
        for(i=0; i<pSrcList->nSrc; i++, pItem++){
          struct AggInfo_col *pCol;
          assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
          if( pExpr->iTable==pItem->iCursor ){
            /* If we reach this point, it means that pExpr refers to a table
            ** that is in the FROM clause of the aggregate query.  
            **
            ** Make an entry for the column in pAggInfo->aCol[] if there
            ** is not an entry there already.
            */

              }
            }
            /* There is now an entry for pExpr in pAggInfo->aCol[] (either
            ** because it was there before or because we just created it).
            ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
            ** pAggInfo->aCol[] entry.
            */
            ExprSetVVAProperty(pExpr, EP_NoReduce);
            pExpr->pAggInfo = pAggInfo;
            pExpr->op = TK_AGG_COLUMN;
            pExpr->iAgg = (i16)k;
            break;
          } /* endif pExpr->iTable==pItem->iCursor */
        } /* end loop over pSrcList */
      }

            }else{
              pItem->iDistinct = -1;
            }
          }
        }
        /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
        */
        assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
        ExprSetVVAProperty(pExpr, EP_NoReduce);
        pExpr->iAgg = (i16)i;
        pExpr->pAggInfo = pAggInfo;
        return WRC_Prune;
      }else{
        return WRC_Continue;
      }
    }

    if( iSkip ){
      sqlite3VdbeResolveLabel(v, iSkip);
    }
  }
}


/*
** The second argument points to an FKey object representing a foreign key
** for which pTab is the child table. An UPDATE statement against pTab
** is currently being processed. For each column of the table that is 
** actually updated, the corresponding element in the aChange[] array
** is zero or greater (if a column is unmodified the corresponding element
** is set to -1). If the rowid column is modified by the UPDATE statement
** the bChngRowid argument is non-zero.
**
** This function returns true if any of the columns that are part of the
** child key for FK constraint *p are modified.
*/
static int fkChildIsModified(
  Table *pTab,                    /* Table being updated */
  FKey *p,                        /* Foreign key for which pTab is the child */
  int *aChange,                   /* Array indicating modified columns */
  int bChngRowid                  /* True if rowid is modified by this update */
){
  int i;
  for(i=0; i<p->nCol; i++){
    int iChildKey = p->aCol[i].iFrom;
    if( aChange[iChildKey]>=0 ) return 1;
    if( iChildKey==pTab->iPKey && bChngRowid ) return 1;
  }
  return 0;
}

/*
** The second argument points to an FKey object representing a foreign key
** for which pTab is the parent table. An UPDATE statement against pTab
** is currently being processed. For each column of the table that is 
** actually updated, the corresponding element in the aChange[] array
** is zero or greater (if a column is unmodified the corresponding element
** is set to -1). If the rowid column is modified by the UPDATE statement
** the bChngRowid argument is non-zero.
**
** This function returns true if any of the columns that are part of the
** parent key for FK constraint *p are modified.
*/
static int fkParentIsModified(
  Table *pTab, 
  FKey *p, 
  int *aChange, 
  int bChngRowid
){
  int i;
  for(i=0; i<p->nCol; i++){
    char *zKey = p->aCol[i].zCol;
    int iKey;
    for(iKey=0; iKey<pTab->nCol; iKey++){
      if( aChange[iKey]>=0 || (iKey==pTab->iPKey && bChngRowid) ){
        Column *pCol = &pTab->aCol[iKey];
        if( zKey ){
          if( 0==sqlite3StrICmp(pCol->zName, zKey) ) return 1;
        }else if( pCol->colFlags & COLFLAG_PRIMKEY ){
          return 1;
        }
      }
    }
  }
  return 0;
}

/*
** This function is called when inserting, deleting or updating a row of
** table pTab to generate VDBE code to perform foreign key constraint 
** processing for the operation.
**
** For a DELETE operation, parameter regOld is passed the index of the
** first register in an array of (pTab->nCol+1) registers containing the

** described for DELETE. Then again after the original record is deleted
** but before the new record is inserted using the INSERT convention. 
*/
void sqlite3FkCheck(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Row is being deleted from this table */ 
  int regOld,                     /* Previous row data is stored here */
  int regNew,                     /* New row data is stored here */
  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
  int bChngRowid                  /* True if rowid is UPDATEd */
){
  sqlite3 *db = pParse->db;       /* Database handle */
  FKey *pFKey;                    /* Used to iterate through FKs */
  int iDb;                        /* Index of database containing pTab */
  const char *zDb;                /* Name of database containing pTab */
  int isIgnoreErrors = pParse->disableTriggers;

    Table *pTo;                   /* Parent table of foreign key pFKey */
    Index *pIdx = 0;              /* Index on key columns in pTo */
    int *aiFree = 0;
    int *aiCol;
    int iCol;
    int i;
    int isIgnore = 0;

    if( aChange 
     && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
     && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 
    ){
      continue;
    }

    /* Find the parent table of this foreign key. Also find a unique index 
    ** on the parent key columns in the parent table. If either of these 
    ** schema items cannot be located, set an error in pParse and return 
    ** early.  */
    if( pParse->disableTriggers ){
      pTo = sqlite3FindTable(db, pFKey->zTo, zDb);

  }

  /* Loop through all the foreign key constraints that refer to this table */
  for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
    Index *pIdx = 0;              /* Foreign key index for pFKey */
    SrcList *pSrc;
    int *aiCol = 0;

    if( aChange && fkParentIsModified(pTab, pFKey, aChange, bChngRowid)==0 ){
      continue;
    }

    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
     && !pParse->pToplevel && !pParse->isMultiWrite 
    ){
      assert( regOld==0 && regNew!=0 );
      /* Inserting a single row into a parent table cannot cause an immediate
      ** foreign key violation. So do nothing in this case.  */

      if( pIdx ){
        for(i=0; i<pIdx->nColumn; i++) mask |= COLUMN_MASK(pIdx->aiColumn[i]);
      }
    }
  }
  return mask;
}


/*
** This function is called before generating code to update or delete a 
** row contained in table pTab. If the operation is a DELETE, then
** parameter aChange is passed a NULL value. For an UPDATE, aChange points
** to an array of size N, where N is the number of columns in table pTab.
** If the i'th column is not modified by the UPDATE, then the corresponding 

      /* A DELETE operation. Foreign key processing is required if the 
      ** table in question is either the child or parent table for any 
      ** foreign key constraint.  */
      return (sqlite3FkReferences(pTab) || pTab->pFKey);
    }else{
      /* This is an UPDATE. Foreign key processing is only required if the
      ** operation modifies one or more child or parent key columns. */

      FKey *p;

      /* Check if any child key columns are being modified. */
      for(p=pTab->pFKey; p; p=p->pNextFrom){


        if( fkChildIsModified(pTab, p, aChange, chngRowid) ) return 1;


      }

      /* Check if any parent key columns are being modified. */
      for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){








        if( fkParentIsModified(pTab, p, aChange, chngRowid) ) return 1;



      }
    }
  }
  return 0;
}

/*

** This function is called when deleting or updating a row to implement
** any required CASCADE, SET NULL or SET DEFAULT actions.
*/
void sqlite3FkActions(
  Parse *pParse,                  /* Parse context */
  Table *pTab,                    /* Table being updated or deleted from */
  ExprList *pChanges,             /* Change-list for UPDATE, NULL for DELETE */
  int regOld,                     /* Address of array containing old row */
  int *aChange,                   /* Array indicating UPDATEd columns (or 0) */
  int bChngRowid                  /* True if rowid is UPDATEd */
){
  /* If foreign-key support is enabled, iterate through all FKs that 
  ** refer to table pTab. If there is an action associated with the FK 
  ** for this operation (either update or delete), invoke the associated 
  ** trigger sub-program.  */
  if( pParse->db->flags&SQLITE_ForeignKeys ){
    FKey *pFKey;                  /* Iterator variable */
    for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
      if( aChange==0 || fkParentIsModified(pTab, pFKey, aChange, bChngRowid) ){
        Trigger *pAct = fkActionTrigger(pParse, pTab, pFKey, pChanges);
        if( pAct ){
          sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);
        }
      }
    }
  }
}

#endif /* ifndef SQLITE_OMIT_TRIGGER */

      }
      sqlite3_result_text(context, z1, n, sqlite3_free);
    }
  }
}

/*
** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented
** as VDBE code so that unused argument values do not have to be computed.
** However, we still need some kind of function implementation for this
** routines in the function table.  The noopFunc macro provides this.
** noopFunc will never be called so it doesn't matter what the implementation
** is.  We might as well use the "version()" function as a substitute.
*/
#define noopFunc versionFunc   /* Substitute function - never called */

/*
** Implementation of random().  Return a random integer.  
*/
static void randomFunc(
  sqlite3_context *context,
  int NotUsed,

** For LIKE and GLOB matching on EBCDIC machines, assume that every
** character is exactly one byte in size.  Also, all characters are
** able to participate in upper-case-to-lower-case mappings in EBCDIC
** whereas only characters less than 0x80 do in ASCII.
*/
#if defined(SQLITE_EBCDIC)
# define sqlite3Utf8Read(A)    (*((*A)++))
# define GlobUpperToLower(A)   A = sqlite3UpperToLower[A]
#else
# define GlobUpperToLower(A)   if( !((A)&~0x7f) ){ A = sqlite3UpperToLower[A]; }
#endif

static const struct compareInfo globInfo = { '*', '?', '[', 0 };
/* The correct SQL-92 behavior is for the LIKE operator to ignore
** case.  Thus  'a' LIKE 'A' would be true. */
static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator

        while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
          SQLITE_SKIP_UTF8(zString);
        }
        return *zString!=0;
      }
      while( (c2 = sqlite3Utf8Read(&zString))!=0 ){
        if( noCase ){
          GlobUpperToLower(c2);
          GlobUpperToLower(c);
          while( c2 != 0 && c2 != c ){
            c2 = sqlite3Utf8Read(&zString);
            GlobUpperToLower(c2);
          }
        }else{
          while( c2 != 0 && c2 != c ){
            c2 = sqlite3Utf8Read(&zString);
          }
        }
        if( c2==0 ) return 0;

        return 0;
      }
    }else if( esc==c && !prevEscape ){
      prevEscape = 1;
    }else{
      c2 = sqlite3Utf8Read(&zString);
      if( noCase ){
        GlobUpperToLower(c);
        GlobUpperToLower(c2);
      }
      if( c!=c2 ){
        return 0;
      }
      prevEscape = 0;
    }
  }

** Set the LIKEOPT flag on the 2-argument function with the given name.
*/
static void setLikeOptFlag(sqlite3 *db, const char *zName, u8 flagVal){
  FuncDef *pDef;
  pDef = sqlite3FindFunction(db, zName, sqlite3Strlen30(zName),
                             2, SQLITE_UTF8, 0);
  if( ALWAYS(pDef) ){
    pDef->funcFlags |= flagVal;
  }
}

/*
** Register the built-in LIKE and GLOB functions.  The caseSensitive
** parameter determines whether or not the LIKE operator is case
** sensitive.  GLOB is always case sensitive.

  ){
    return 0;
  }
  assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
  pDef = sqlite3FindFunction(db, pExpr->u.zToken, 
                             sqlite3Strlen30(pExpr->u.zToken),
                             2, SQLITE_UTF8, 0);
  if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
    return 0;
  }

  /* The memcpy() statement assumes that the wildcard characters are
  ** the first three statements in the compareInfo structure.  The
  ** asserts() that follow verify that assumption
  */
  memcpy(aWc, pDef->pUserData, 3);
  assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
  assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
  assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
  *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
  return 1;
}

/*
** All all of the FuncDef structures in the aBuiltinFunc[] array above
** to the global function hash table.  This occurs at start-time (as
** a consequence of calling sqlite3_initialize()).

    FUNCTION(round,              1, 0, 0, roundFunc        ),
    FUNCTION(round,              2, 0, 0, roundFunc        ),
#endif
    FUNCTION(upper,              1, 0, 0, upperFunc        ),
    FUNCTION(lower,              1, 0, 0, lowerFunc        ),
    FUNCTION(coalesce,           1, 0, 0, 0                ),
    FUNCTION(coalesce,           0, 0, 0, 0                ),
    FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
    FUNCTION(hex,                1, 0, 0, hexFunc          ),
    FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
    FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    FUNCTION(random,             0, 0, 0, randomFunc       ),
    FUNCTION(randomblob,         1, 0, 0, randomBlob       ),
    FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
    FUNCTION(sqlite_version,     0, 0, 0, versionFunc      ),
    FUNCTION(sqlite_source_id,   0, 0, 0, sourceidFunc     ),
    FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

    FUNCTION(load_extension,     1, 0, 0, loadExt          ),
    FUNCTION(load_extension,     2, 0, 0, loadExt          ),
  #endif
    AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
    AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
    AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
 /* AGGREGATE(count,             0, 0, 0, countStep,       countFinalize  ), */
    {0,SQLITE_UTF8|SQLITE_FUNC_COUNT,0,0,0,countStep,countFinalize,"count",0,0},
    AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),
    AGGREGATE(group_concat,      1, 0, 0, groupConcatStep, groupConcatFinalize),
    AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
  
    LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
  #ifdef SQLITE_CASE_SENSITIVE_LIKE
    LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),

    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      sqlite3GenerateConstraintChecks(pParse, pTab, baseCur, regIns, aRegIdx,
          keyColumn>=0, 0, onError, endOfLoop, &isReplace
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
      sqlite3CompleteInsertion(
          pParse, pTab, baseCur, regIns, aRegIdx, 0, appendFlag, isReplace==0
      );
    }
  }

  /* Update the count of rows that are inserted

    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pSrcIdx->zName));
    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
    VdbeComment((v, "%s", pDestIdx->zName));
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
    sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
  }

  
  /* Check if an existing function is being overridden or deleted. If so,
  ** and there are active VMs, then return SQLITE_BUSY. If a function
  ** is being overridden/deleted but there are no active VMs, allow the
  ** operation to continue but invalidate all precompiled statements.
  */
  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
    if( db->nVdbeActive ){
      sqlite3Error(db, SQLITE_BUSY, 
        "unable to delete/modify user-function due to active statements");
      assert( !db->mallocFailed );
      return SQLITE_BUSY;
    }else{
      sqlite3ExpirePreparedStatements(db);

  ** being replaced invoke the destructor function here. */
  functionDestroy(db, p);

  if( pDestructor ){
    pDestructor->nRef++;
  }
  p->pDestructor = pDestructor;
  p->funcFlags &= SQLITE_FUNC_ENCMASK;
  p->xFunc = xFunc;
  p->xStep = xStep;
  p->xFinalize = xFinal;
  p->pUserData = pUserData;
  p->nArg = (u16)nArg;
  return SQLITE_OK;
}

/*
** Free memory that might be associated with a particular database
** connection.
*/
void sqlite3DbFree(sqlite3 *db, void *p){
  assert( db==0 || sqlite3_mutex_held(db->mutex) );
  if( p==0 ) return;
  if( db ){
    if( db->pnBytesFreed ){
      *db->pnBytesFreed += sqlite3DbMallocSize(db, p);
      return;
    }
    if( isLookaside(db, p) ){
      LookasideSlot *pBuf = (LookasideSlot*)p;

** Returns non-zero if the character should be treated as a directory
** separator.
*/
#ifndef winIsDirSep
#  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))
#endif

/*
** This macro is used when a local variable is set to a value that is
** [sometimes] not used by the code (e.g. via conditional compilation).
*/
#ifndef UNUSED_VARIABLE_VALUE
#  define UNUSED_VARIABLE_VALUE(x) (void)(x)
#endif

/*
** Returns the string that should be used as the directory separator.
*/
#ifndef winGetDirDep
#  ifdef __CYGWIN__
#    define winGetDirDep()              "/"
#  else

** 2:   Operating system is WinNT.
**
** In order to facilitate testing on a WinNT system, the test fixture
** can manually set this value to 1 to emulate Win98 behavior.
*/
#ifdef SQLITE_TEST
int sqlite3_os_type = 0;
#elif !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
      defined(SQLITE_WIN32_HAS_ANSI) && defined(SQLITE_WIN32_HAS_WIDE)
static int sqlite3_os_type = 0;
#endif

#ifndef SYSCALL
#  define SYSCALL sqlite3_syscall_ptr
#endif

#else
  { "GetVersionExA",           (SYSCALL)0,                       0 },
#endif

#define osGetVersionExA ((BOOL(WINAPI*)( \
        LPOSVERSIONINFOA))aSyscall[34].pCurrent)

#if defined(SQLITE_WIN32_HAS_WIDE)
  { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
#else
  { "GetVersionExW",           (SYSCALL)0,                       0 },
#endif

#define osGetVersionExW ((BOOL(WINAPI*)( \
        LPOSVERSIONINFOW))aSyscall[35].pCurrent)

  { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },

#define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \
        SIZE_T))aSyscall[36].pCurrent)

#if !SQLITE_OS_WINRT
  { "HeapCreate",              (SYSCALL)HeapCreate,              0 },
#else
  { "HeapCreate",              (SYSCALL)0,                       0 },
#endif

#define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \
        SIZE_T))aSyscall[37].pCurrent)

#if !SQLITE_OS_WINRT
  { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },
#else
  { "HeapDestroy",             (SYSCALL)0,                       0 },
#endif

#define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)

  { "HeapFree",                (SYSCALL)HeapFree,                0 },

#define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)

  { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },

#define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \
        SIZE_T))aSyscall[40].pCurrent)

  { "HeapSize",                (SYSCALL)HeapSize,                0 },

#define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \
        LPCVOID))aSyscall[41].pCurrent)

#if !SQLITE_OS_WINRT
  { "HeapValidate",            (SYSCALL)HeapValidate,            0 },
#else
  { "HeapValidate",            (SYSCALL)0,                       0 },
#endif

#define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \
        LPCVOID))aSyscall[42].pCurrent)

#if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
  { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },
#else
  { "LoadLibraryA",            (SYSCALL)0,                       0 },
#endif

#define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[43].pCurrent)

#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
        !defined(SQLITE_OMIT_LOAD_EXTENSION)
  { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },
#else
  { "LoadLibraryW",            (SYSCALL)0,                       0 },
#endif

#define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[44].pCurrent)

#if !SQLITE_OS_WINRT
  { "LocalFree",               (SYSCALL)LocalFree,               0 },
#else
  { "LocalFree",               (SYSCALL)0,                       0 },
#endif

#define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[45].pCurrent)

#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
  { "LockFile",                (SYSCALL)LockFile,                0 },
#else
  { "LockFile",                (SYSCALL)0,                       0 },
#endif

#ifndef osLockFile
#define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        DWORD))aSyscall[46].pCurrent)
#endif

#if !SQLITE_OS_WINCE
  { "LockFileEx",              (SYSCALL)LockFileEx,              0 },
#else
  { "LockFileEx",              (SYSCALL)0,                       0 },
#endif

#ifndef osLockFileEx
#define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[47].pCurrent)
#endif

#if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL))
  { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
#else
  { "MapViewOfFile",           (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        SIZE_T))aSyscall[48].pCurrent)

  { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },

#define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \
        int))aSyscall[49].pCurrent)

  { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },

#define osQueryPerformanceCounter ((BOOL(WINAPI*)( \
        LARGE_INTEGER*))aSyscall[50].pCurrent)

  { "ReadFile",                (SYSCALL)ReadFile,                0 },

#define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \
        LPOVERLAPPED))aSyscall[51].pCurrent)

  { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },

#define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[52].pCurrent)

#if !SQLITE_OS_WINRT
  { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },
#else
  { "SetFilePointer",          (SYSCALL)0,                       0 },
#endif

#define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \
        DWORD))aSyscall[53].pCurrent)

#if !SQLITE_OS_WINRT
  { "Sleep",                   (SYSCALL)Sleep,                   0 },
#else
  { "Sleep",                   (SYSCALL)0,                       0 },
#endif

#define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[54].pCurrent)

  { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },

#define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \
        LPFILETIME))aSyscall[55].pCurrent)

#if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
  { "UnlockFile",              (SYSCALL)UnlockFile,              0 },
#else
  { "UnlockFile",              (SYSCALL)0,                       0 },
#endif

#ifndef osUnlockFile
#define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        DWORD))aSyscall[56].pCurrent)
#endif

#if !SQLITE_OS_WINCE
  { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },
#else
  { "UnlockFileEx",            (SYSCALL)0,                       0 },
#endif

#define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
        LPOVERLAPPED))aSyscall[57].pCurrent)

#if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL)
  { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
#else
  { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
#endif

#define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[58].pCurrent)

  { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },

#define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \
        LPCSTR,LPBOOL))aSyscall[59].pCurrent)

  { "WriteFile",               (SYSCALL)WriteFile,               0 },

#define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \
        LPOVERLAPPED))aSyscall[60].pCurrent)

#if SQLITE_OS_WINRT
  { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },
#else
  { "CreateEventExW",          (SYSCALL)0,                       0 },
#endif

#define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \
        DWORD,DWORD))aSyscall[61].pCurrent)

#if !SQLITE_OS_WINRT
  { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },
#else
  { "WaitForSingleObject",     (SYSCALL)0,                       0 },
#endif

#define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \
        DWORD))aSyscall[62].pCurrent)

#if SQLITE_OS_WINRT
  { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },
#else
  { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },
#endif

#define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \
        BOOL))aSyscall[63].pCurrent)

#if SQLITE_OS_WINRT
  { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },
#else
  { "SetFilePointerEx",        (SYSCALL)0,                       0 },
#endif

#define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \
        PLARGE_INTEGER,DWORD))aSyscall[64].pCurrent)

#if SQLITE_OS_WINRT
  { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },
#else
  { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
#endif

#define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
        FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[65].pCurrent)

#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL)
  { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
#else
  { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
#endif

#define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
        SIZE_T))aSyscall[66].pCurrent)

#if SQLITE_OS_WINRT
  { "CreateFile2",             (SYSCALL)CreateFile2,             0 },
#else
  { "CreateFile2",             (SYSCALL)0,                       0 },
#endif

#define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \
        LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[67].pCurrent)

#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)
  { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },
#else
  { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },
#endif

#define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \
        DWORD))aSyscall[68].pCurrent)

#if SQLITE_OS_WINRT
  { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },
#else
  { "GetTickCount64",          (SYSCALL)0,                       0 },
#endif

#define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[69].pCurrent)

#if SQLITE_OS_WINRT
  { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },
#else
  { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },
#endif

#define osGetNativeSystemInfo ((VOID(WINAPI*)( \
        LPSYSTEM_INFO))aSyscall[70].pCurrent)

#if defined(SQLITE_WIN32_HAS_ANSI)
  { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },
#else
  { "OutputDebugStringA",      (SYSCALL)0,                       0 },
#endif

#define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[71].pCurrent)

#if defined(SQLITE_WIN32_HAS_WIDE)
  { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },
#else
  { "OutputDebugStringW",      (SYSCALL)0,                       0 },
#endif

#define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[72].pCurrent)

  { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },

#define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[73].pCurrent)

#if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_WAL)
  { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
#else
  { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
#endif

#define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
        LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[74].pCurrent)

}; /* End of the overrideable system calls */

/*
** This is the xSetSystemCall() method of sqlite3_vfs for all of the
** "win32" VFSes.  Return SQLITE_OK opon successfully updating the
** system call pointer, or SQLITE_NOTFOUND if there is no configurable

** Here is an interesting observation:  Win95, Win98, and WinME lack
** the LockFileEx() API.  But we can still statically link against that
** API as long as we don't call it when running Win95/98/ME.  A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
*/
#ifndef NTDDI_WIN8
#  define NTDDI_WIN8                        0x06020000
#endif

#if SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
# define osIsNT()  (1)
#elif !defined(SQLITE_WIN32_HAS_WIDE)
# define osIsNT()  (0)
#else
  static int osIsNT(void){
    if( sqlite3_os_type==0 ){
#if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WIN8
      OSVERSIONINFOW sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      osGetVersionExW(&sInfo);
#else
      OSVERSIONINFOA sInfo;
      sInfo.dwOSVersionInfoSize = sizeof(sInfo);
      osGetVersionExA(&sInfo);
#endif
      sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
    }
    return sqlite3_os_type==2;
  }
#endif

#ifdef SQLITE_WIN32_MALLOC

  assert( hHeap!=INVALID_HANDLE_VALUE );
#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
  assert ( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
  assert( nBytes>=0 );
  p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
  if( !p ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",
                nBytes, osGetLastError(), (void*)hHeap);
  }
  return p;
}

/*
** Free memory.
*/
static void winMemFree(void *pPrior){
  HANDLE hHeap;

  winMemAssertMagic();
  hHeap = winMemGetHeap();
  assert( hHeap!=0 );
  assert( hHeap!=INVALID_HANDLE_VALUE );
#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
  assert ( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
#endif
  if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
  if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",
                pPrior, osGetLastError(), (void*)hHeap);
  }
}

/*
** Change the size of an existing memory allocation
*/

  assert( nBytes>=0 );
  if( !pPrior ){
    p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
  }else{
    p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
  }
  if( !p ){
    sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",
                pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),
                (void*)hHeap);
  }
  return p;
}

/*

  assert( hHeap!=INVALID_HANDLE_VALUE );
#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
  assert ( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
  if( !p ) return 0;
  n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
  if( n==(SIZE_T)-1 ){
    sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",
                p, osGetLastError(), (void*)hHeap);
    return 0;
  }
  return (int)n;
}

/*

#if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE
  if( !pWinMemData->hHeap ){
    pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,
                                      SQLITE_WIN32_HEAP_INIT_SIZE,
                                      SQLITE_WIN32_HEAP_MAX_SIZE);
    if( !pWinMemData->hHeap ){
      sqlite3_log(SQLITE_NOMEM,
          "failed to HeapCreate (%lu), flags=%u, initSize=%u, maxSize=%u",
          osGetLastError(), SQLITE_WIN32_HEAP_FLAGS,
          SQLITE_WIN32_HEAP_INIT_SIZE, SQLITE_WIN32_HEAP_MAX_SIZE);
      return SQLITE_NOMEM;
    }
    pWinMemData->bOwned = TRUE;
    assert( pWinMemData->bOwned );
  }
#else
  pWinMemData->hHeap = osGetProcessHeap();
  if( !pWinMemData->hHeap ){
    sqlite3_log(SQLITE_NOMEM,
        "failed to GetProcessHeap (%lu)", osGetLastError());
    return SQLITE_NOMEM;
  }
  pWinMemData->bOwned = FALSE;
  assert( !pWinMemData->bOwned );
#endif
  assert( pWinMemData->hHeap!=0 );
  assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );

  if( pWinMemData->hHeap ){
    assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
#if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
    assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
#endif
    if( pWinMemData->bOwned ){
      if( !osHeapDestroy(pWinMemData->hHeap) ){
        sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",
                    osGetLastError(), (void*)pWinMemData->hHeap);
      }
      pWinMemData->bOwned = FALSE;
    }
    pWinMemData->hHeap = NULL;
  }
}

**
** This is not a VFS shared-memory method; it is a utility function called
** by VFS shared-memory methods.
*/
static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
  winShmNode **pp;
  winShmNode *p;

  assert( winShmMutexHeld() );
  OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
           osGetCurrentProcessId(), deleteFlag));
  pp = &winShmNodeList;
  while( (p = *pp)!=0 ){
    if( p->nRef==0 ){
      int i;
      if( p->mutex ) sqlite3_mutex_free(p->mutex);
      for(i=0; i<p->nRegion; i++){
        BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
        OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
        UNUSED_VARIABLE_VALUE(bRc);
        bRc = osCloseHandle(p->aRegion[i].hMap);
        OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
                 osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
        UNUSED_VARIABLE_VALUE(bRc);
      }
      if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
        SimulateIOErrorBenign(1);
        winClose((sqlite3_file *)&p->hFile);
        SimulateIOErrorBenign(0);
      }
      if( deleteFlag ){

/****************************************************************************
**************************** sqlite3_vfs methods ****************************
**
** This division contains the implementation of methods on the
** sqlite3_vfs object.
*/

#if 0
/*
** Convert a filename from whatever the underlying operating system
** supports for filenames into UTF-8.  Space to hold the result is
** obtained from malloc and must be freed by the calling function.
*/
static char *winConvertToUtf8Filename(const void *zFilename){
  char *zConverted = 0;
  if( osIsNT() ){
    zConverted = winUnicodeToUtf8(zFilename);
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    zConverted = sqlite3_win32_mbcs_to_utf8(zFilename);
  }
#endif
  /* caller will handle out of memory */
  return zConverted;
}
#endif

/*
** Convert a UTF-8 filename into whatever form the underlying
** operating system wants filenames in.  Space to hold the result
** is obtained from malloc and must be freed by the calling
** function.
*/

    winGetSystemCall,    /* xGetSystemCall */
    winNextSystemCall,   /* xNextSystemCall */
  };
#endif

  /* Double-check that the aSyscall[] array has been constructed
  ** correctly.  See ticket [bb3a86e890c8e96ab] */
  assert( ArraySize(aSyscall)==75 );

  /* get memory map allocation granularity */
  memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
#if SQLITE_OS_WINRT
  osGetNativeSystemInfo(&winSysInfo);
#else
  osGetSystemInfo(&winSysInfo);

    A.zStart = B.z;
    A.zEnd = &E.z[E.n];
  }
%endif SQLITE_OMIT_SUBQUERY

/* CASE expressions */
expr(A) ::= CASE(C) case_operand(X) case_exprlist(Y) case_else(Z) END(E). {
  A.pExpr = sqlite3PExpr(pParse, TK_CASE, X, 0, 0);
  if( A.pExpr ){
    A.pExpr->x.pList = Z ? sqlite3ExprListAppend(pParse,Y,Z) : Y;
    sqlite3ExprSetHeight(pParse, A.pExpr);
  }else{
    sqlite3ExprListDelete(pParse->db, Y);
    sqlite3ExprDelete(pParse->db, Z);
  }
  A.zStart = C.z;
  A.zEnd = &E.z[E.n];
}
%type case_exprlist {ExprList*}
%destructor case_exprlist {sqlite3ExprListDelete(pParse->db, $$);}
case_exprlist(A) ::= case_exprlist(X) WHEN expr(Y) THEN expr(Z). {

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
*/
#include "sqliteInt.h"

#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
#  if defined(__APPLE__)
#    define SQLITE_ENABLE_LOCKING_STYLE 1
#  else
#    define SQLITE_ENABLE_LOCKING_STYLE 0
#  endif
#endif

/***************************************************************************
** The next block of code, including the PragTyp_XXXX macro definitions and
** the aPragmaName[] object is composed of generated code. DO NOT EDIT.
**
** To add new pragmas, edit the code in ../tool/mkpragmatab.tcl and rerun
** that script.  Then copy/paste the output in place of the following:
*/
#define PragTyp_HEADER_VALUE                   0
#define PragTyp_AUTO_VACUUM                    1
#define PragTyp_FLAG                           2
#define PragTyp_BUSY_TIMEOUT                   3
#define PragTyp_CACHE_SIZE                     4
#define PragTyp_CASE_SENSITIVE_LIKE            5
#define PragTyp_COLLATION_LIST                 6
#define PragTyp_COMPILE_OPTIONS                7
#define PragTyp_DATA_STORE_DIRECTORY           8
#define PragTyp_DATABASE_LIST                  9
#define PragTyp_DEFAULT_CACHE_SIZE            10
#define PragTyp_ENCODING                      11
#define PragTyp_FOREIGN_KEY_CHECK             12
#define PragTyp_FOREIGN_KEY_LIST              13
#define PragTyp_INCREMENTAL_VACUUM            14
#define PragTyp_INDEX_INFO                    15
#define PragTyp_INDEX_LIST                    16
#define PragTyp_INTEGRITY_CHECK               17
#define PragTyp_JOURNAL_MODE                  18
#define PragTyp_JOURNAL_SIZE_LIMIT            19
#define PragTyp_LOCK_PROXY_FILE               20
#define PragTyp_LOCKING_MODE                  21
#define PragTyp_PAGE_COUNT                    22
#define PragTyp_MMAP_SIZE                     23
#define PragTyp_PAGE_SIZE                     24
#define PragTyp_SECURE_DELETE                 25
#define PragTyp_SHRINK_MEMORY                 26
#define PragTyp_SOFT_HEAP_LIMIT               27
#define PragTyp_SYNCHRONOUS                   28
#define PragTyp_TABLE_INFO                    29
#define PragTyp_TEMP_STORE                    30
#define PragTyp_TEMP_STORE_DIRECTORY          31
#define PragTyp_WAL_AUTOCHECKPOINT            32
#define PragTyp_WAL_CHECKPOINT                33
#define PragTyp_ACTIVATE_EXTENSIONS           34
#define PragTyp_HEXKEY                        35
#define PragTyp_KEY                           36
#define PragTyp_REKEY                         37
#define PragTyp_LOCK_STATUS                   38
#define PragTyp_PARSER_TRACE                  39
#define PragFlag_NeedSchema           0x01
static const struct sPragmaNames {
  const char *const zName;  /* Name of pragma */
  u8 ePragTyp;              /* PragTyp_XXX value */
  u8 mPragFlag;             /* Zero or more PragFlag_XXX values */
  u32 iArg;                 /* Extra argument */
} aPragmaNames[] = {
#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
  { /* zName:     */ "activate_extensions",
    /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  { /* zName:     */ "application_id",
    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_AUTOVACUUM)
  { /* zName:     */ "auto_vacuum",
    /* ePragTyp:  */ PragTyp_AUTO_VACUUM,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)
  { /* zName:     */ "automatic_index",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_AutoIndex },
#endif
  { /* zName:     */ "busy_timeout",
    /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "cache_size",
    /* ePragTyp:  */ PragTyp_CACHE_SIZE,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "cache_spill",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_CacheSpill },
  { /* zName:     */ "case_sensitive_like",
    /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "checkpoint_fullfsync",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_CkptFullFSync },
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
  { /* zName:     */ "collation_list",
    /* ePragTyp:  */ PragTyp_COLLATION_LIST,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)
  { /* zName:     */ "compile_options",
    /* ePragTyp:  */ PragTyp_COMPILE_OPTIONS,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "count_changes",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_CountRows },
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN
  { /* zName:     */ "data_store_directory",
    /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
  { /* zName:     */ "database_list",
    /* ePragTyp:  */ PragTyp_DATABASE_LIST,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  { /* zName:     */ "default_cache_size",
    /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
  { /* zName:     */ "defer_foreign_keys",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_DeferFKs },
#endif
  { /* zName:     */ "empty_result_callbacks",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_NullCallback },
#if !defined(SQLITE_OMIT_UTF16)
  { /* zName:     */ "encoding",
    /* ePragTyp:  */ PragTyp_ENCODING,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
  { /* zName:     */ "foreign_key_check",
    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_CHECK,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY)
  { /* zName:     */ "foreign_key_list",
    /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
  { /* zName:     */ "foreign_keys",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_ForeignKeys },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  { /* zName:     */ "freelist_count",
    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "full_column_names",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_FullColNames },
  { /* zName:     */ "fullfsync",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_FullFSync },
#if defined(SQLITE_HAS_CODEC)
  { /* zName:     */ "hexkey",
    /* ePragTyp:  */ PragTyp_HEXKEY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "hexrekey",
    /* ePragTyp:  */ PragTyp_HEXKEY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_CHECK)
  { /* zName:     */ "ignore_check_constraints",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_IgnoreChecks },
#endif
#if !defined(SQLITE_OMIT_AUTOVACUUM)
  { /* zName:     */ "incremental_vacuum",
    /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
  { /* zName:     */ "index_info",
    /* ePragTyp:  */ PragTyp_INDEX_INFO,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
  { /* zName:     */ "index_list",
    /* ePragTyp:  */ PragTyp_INDEX_LIST,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
  { /* zName:     */ "integrity_check",
    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "journal_mode",
    /* ePragTyp:  */ PragTyp_JOURNAL_MODE,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
  { /* zName:     */ "journal_size_limit",
    /* ePragTyp:  */ PragTyp_JOURNAL_SIZE_LIMIT,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if defined(SQLITE_HAS_CODEC)
  { /* zName:     */ "key",
    /* ePragTyp:  */ PragTyp_KEY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "legacy_file_format",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_LegacyFileFmt },
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
  { /* zName:     */ "lock_proxy_file",
    /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  { /* zName:     */ "lock_status",
    /* ePragTyp:  */ PragTyp_LOCK_STATUS,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "locking_mode",
    /* ePragTyp:  */ PragTyp_LOCKING_MODE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "max_page_count",
    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
  { /* zName:     */ "mmap_size",
    /* ePragTyp:  */ PragTyp_MMAP_SIZE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "page_count",
    /* ePragTyp:  */ PragTyp_PAGE_COUNT,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
  { /* zName:     */ "page_size",
    /* ePragTyp:  */ PragTyp_PAGE_SIZE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if defined(SQLITE_DEBUG)
  { /* zName:     */ "parser_trace",
    /* ePragTyp:  */ PragTyp_PARSER_TRACE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "query_only",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_QueryOnly },
#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
  { /* zName:     */ "quick_check",
    /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "read_uncommitted",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_ReadUncommitted },
  { /* zName:     */ "recursive_triggers",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_RecTriggers },
#if defined(SQLITE_HAS_CODEC)
  { /* zName:     */ "rekey",
    /* ePragTyp:  */ PragTyp_REKEY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "reverse_unordered_selects",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_ReverseOrder },
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  { /* zName:     */ "schema_version",
    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "secure_delete",
    /* ePragTyp:  */ PragTyp_SECURE_DELETE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "short_column_names",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_ShortColNames },
  { /* zName:     */ "shrink_memory",
    /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "soft_heap_limit",
    /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#if defined(SQLITE_DEBUG)
  { /* zName:     */ "sql_trace",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_SqlTrace },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "synchronous",
    /* ePragTyp:  */ PragTyp_SYNCHRONOUS,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
  { /* zName:     */ "table_info",
    /* ePragTyp:  */ PragTyp_TABLE_INFO,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  { /* zName:     */ "temp_store",
    /* ePragTyp:  */ PragTyp_TEMP_STORE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "temp_store_directory",
    /* ePragTyp:  */ PragTyp_TEMP_STORE_DIRECTORY,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  { /* zName:     */ "user_version",
    /* ePragTyp:  */ PragTyp_HEADER_VALUE,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
#endif
#if defined(SQLITE_DEBUG)
  { /* zName:     */ "vdbe_addoptrace",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_VdbeAddopTrace },
  { /* zName:     */ "vdbe_debug",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },
  { /* zName:     */ "vdbe_listing",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_VdbeListing },
  { /* zName:     */ "vdbe_trace",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_VdbeTrace },
#endif
#if !defined(SQLITE_OMIT_WAL)
  { /* zName:     */ "wal_autocheckpoint",
    /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,
    /* ePragFlag: */ 0,
    /* iArg:      */ 0 },
  { /* zName:     */ "wal_checkpoint",
    /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,
    /* ePragFlag: */ PragFlag_NeedSchema,
    /* iArg:      */ 0 },
#endif
  { /* zName:     */ "writable_schema",
    /* ePragTyp:  */ PragTyp_FLAG,
    /* ePragFlag: */ 0,
    /* iArg:      */ SQLITE_WriteSchema|SQLITE_RecoveryMode },
};
/* Number of pragmas: 55 on by default, 67 total. */
/* End of the automatically generated pragma table.
***************************************************************************/

/*
** Interpret the given string as a safety level.  Return 0 for OFF,
** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
** unrecognized string argument.  The FULL option is disallowed
** if the omitFull parameter it 1.
**
** Note that the values returned are one less that the values that

  }
}
#else
# define setAllPagerFlags(X)  /* no-op */
#endif





























































































/*
** Return a human-readable name for a constraint resolution action.
*/
#ifndef SQLITE_OMIT_FOREIGN_KEY
static const char *actionName(u8 action){
  const char *zName;
  switch( action ){

  Token *pValue,      /* Token for <value>, or NULL */
  int minusFlag       /* True if a '-' sign preceded <value> */
){
  char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */
  char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
  const char *zDb = 0;   /* The database name */
  Token *pId;            /* Pointer to <id> token */
  char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */
  int iDb;               /* Database index for <database> */
  int lwr, upr, mid;           /* Binary search bounds */
  int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */
  sqlite3 *db = pParse->db;    /* The database connection */
  Db *pDb;                     /* The specific database being pragmaed */
  Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */

  if( v==0 ) return;
  sqlite3VdbeRunOnlyOnce(v);

      int mem = ++pParse->nMem;
      sqlite3VdbeAddOp4(v, OP_String8, 0, mem, 0, aFcntl[0], 0);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "result", SQLITE_STATIC);
      sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
      sqlite3_free(aFcntl[0]);
    }
    goto pragma_out;
  }
  if( rc!=SQLITE_NOTFOUND ){
    if( aFcntl[0] ){
      sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);
      sqlite3_free(aFcntl[0]);
    }
    pParse->nErr++;
    pParse->rc = rc;
    goto pragma_out;
  }

  /* Locate the pragma in the lookup table */
  lwr = 0;
  upr = ArraySize(aPragmaNames)-1;
  while( lwr<=upr ){
    mid = (lwr+upr)/2;
    rc = sqlite3_stricmp(zLeft, aPragmaNames[mid].zName);
    if( rc==0 ) break;
    if( rc<0 ){
      upr = mid - 1;
    }else{
      lwr = mid + 1;
    }
  }
  if( lwr>upr ) goto pragma_out;

  /* Make sure the database schema is loaded if the pragma requires that */
  if( (aPragmaNames[mid].mPragFlag & PragFlag_NeedSchema)!=0 ){
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
  }

  /* Jump to the appropriate pragma handler */
  switch( aPragmaNames[mid].ePragTyp ){
  
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  /*
  **  PRAGMA [database.]default_cache_size
  **  PRAGMA [database.]default_cache_size=N
  **
  ** The first form reports the current persistent setting for the
  ** page cache size.  The value returned is the maximum number of
  ** pages in the page cache.  The second form sets both the current
  ** page cache size value and the persistent page cache size value
  ** stored in the database file.
  **
  ** Older versions of SQLite would set the default cache size to a
  ** negative number to indicate synchronous=OFF.  These days, synchronous
  ** is always on by default regardless of the sign of the default cache
  ** size.  But continue to take the absolute value of the default cache
  ** size of historical compatibility.
  */
  case PragTyp_DEFAULT_CACHE_SIZE: {
    static const VdbeOpList getCacheSize[] = {
      { OP_Transaction, 0, 0,        0},                         /* 0 */
      { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */
      { OP_IfPos,       1, 8,        0},
      { OP_Integer,     0, 2,        0},
      { OP_Subtract,    1, 2,        1},
      { OP_IfPos,       1, 8,        0},
      { OP_Integer,     0, 1,        0},                         /* 6 */
      { OP_Noop,        0, 0,        0},
      { OP_ResultRow,   1, 1,        0},
    };
    int addr;

    sqlite3VdbeUsesBtree(v, iDb);
    if( !zRight ){
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", SQLITE_STATIC);
      pParse->nMem += 2;
      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, iDb);
      sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE);
    }else{
      int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }
#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */

#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  /*
  **  PRAGMA [database.]page_size
  **  PRAGMA [database.]page_size=N
  **
  ** The first form reports the current setting for the
  ** database page size in bytes.  The second form sets the
  ** database page size value.  The value can only be set if
  ** the database has not yet been created.
  */
  case PragTyp_PAGE_SIZE: {
    Btree *pBt = pDb->pBt;
    assert( pBt!=0 );
    if( !zRight ){
      int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
      returnSingleInt(pParse, "page_size", size);
    }else{
      /* Malloc may fail when setting the page-size, as there is an internal
      ** buffer that the pager module resizes using sqlite3_realloc().
      */
      db->nextPagesize = sqlite3Atoi(zRight);
      if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){
        db->mallocFailed = 1;
      }
    }
    break;
  }

  /*
  **  PRAGMA [database.]secure_delete
  **  PRAGMA [database.]secure_delete=ON/OFF
  **
  ** The first form reports the current setting for the
  ** secure_delete flag.  The second form changes the secure_delete
  ** flag setting and reports thenew value.
  */
  case PragTyp_SECURE_DELETE: {
    Btree *pBt = pDb->pBt;
    int b = -1;
    assert( pBt!=0 );
    if( zRight ){
      b = sqlite3GetBoolean(zRight, 0);
    }
    if( pId2->n==0 && b>=0 ){
      int ii;
      for(ii=0; ii<db->nDb; ii++){
        sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);
      }
    }
    b = sqlite3BtreeSecureDelete(pBt, b);
    returnSingleInt(pParse, "secure_delete", b);
    break;
  }

  /*
  **  PRAGMA [database.]max_page_count
  **  PRAGMA [database.]max_page_count=N
  **
  ** The first form reports the current setting for the
  ** maximum number of pages in the database file.  The 
  ** second form attempts to change this setting.  Both
  ** forms return the current setting.
  **
  ** The absolute value of N is used.  This is undocumented and might
  ** change.  The only purpose is to provide an easy way to test
  ** the sqlite3AbsInt32() function.
  **
  **  PRAGMA [database.]page_count
  **
  ** Return the number of pages in the specified database.
  */
  case PragTyp_PAGE_COUNT: {


    int iReg;

    sqlite3CodeVerifySchema(pParse, iDb);
    iReg = ++pParse->nMem;
    if( sqlite3Tolower(zLeft[0])=='p' ){
      sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
    }else{
      sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, 
                        sqlite3AbsInt32(sqlite3Atoi(zRight)));
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
    break;
  }

  /*
  **  PRAGMA [database.]locking_mode
  **  PRAGMA [database.]locking_mode = (normal|exclusive)
  */
  case PragTyp_LOCKING_MODE: {
    const char *zRet = "normal";
    int eMode = getLockingMode(zRight);

    if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
      /* Simple "PRAGMA locking_mode;" statement. This is a query for
      ** the current default locking mode (which may be different to
      ** the locking-mode of the main database).

        }
        db->dfltLockMode = (u8)eMode;
      }
      pPager = sqlite3BtreePager(pDb->pBt);
      eMode = sqlite3PagerLockingMode(pPager, eMode);
    }

    assert( eMode==PAGER_LOCKINGMODE_NORMAL
            || eMode==PAGER_LOCKINGMODE_EXCLUSIVE );
    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
      zRet = "exclusive";
    }
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", SQLITE_STATIC);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    break;
  }

  /*
  **  PRAGMA [database.]journal_mode
  **  PRAGMA [database.]journal_mode =
  **                      (delete|persist|off|truncate|memory|wal|off)
  */
  case PragTyp_JOURNAL_MODE: {
    int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */
    int ii;           /* Loop counter */









    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);

    if( zRight==0 ){
      /* If there is no "=MODE" part of the pragma, do a query for the
      ** current mode */
      eMode = PAGER_JOURNALMODE_QUERY;

    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    break;
  }

  /*
  **  PRAGMA [database.]journal_size_limit
  **  PRAGMA [database.]journal_size_limit=N
  **
  ** Get or set the size limit on rollback journal files.
  */
  case PragTyp_JOURNAL_SIZE_LIMIT: {
    Pager *pPager = sqlite3BtreePager(pDb->pBt);
    i64 iLimit = -2;
    if( zRight ){
      sqlite3Atoi64(zRight, &iLimit, sqlite3Strlen30(zRight), SQLITE_UTF8);
      if( iLimit<-1 ) iLimit = -1;
    }
    iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
    returnSingleInt(pParse, "journal_size_limit", iLimit);
    break;
  }

#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [database.]auto_vacuum
  **  PRAGMA [database.]auto_vacuum=N
  **
  ** Get or set the value of the database 'auto-vacuum' parameter.
  ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL
  */
#ifndef SQLITE_OMIT_AUTOVACUUM
  case PragTyp_AUTO_VACUUM: {
    Btree *pBt = pDb->pBt;
    assert( pBt!=0 );



    if( !zRight ){






      returnSingleInt(pParse, "auto_vacuum", sqlite3BtreeGetAutoVacuum(pBt));
    }else{
      int eAuto = getAutoVacuum(zRight);
      assert( eAuto>=0 && eAuto<=2 );
      db->nextAutovac = (u8)eAuto;

      /* Call SetAutoVacuum() to set initialize the internal auto and
      ** incr-vacuum flags. This is required in case this connection
      ** creates the database file. It is important that it is created
      ** as an auto-vacuum capable db.
      */
      rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
      if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
        /* When setting the auto_vacuum mode to either "full" or 
        ** "incremental", write the value of meta[6] in the database
        ** file. Before writing to meta[6], check that meta[3] indicates
        ** that this really is an auto-vacuum capable database.
        */
        static const VdbeOpList setMeta6[] = {
          { OP_Transaction,    0,         1,                 0},    /* 0 */
          { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
          { OP_If,             1,         0,                 0},    /* 2 */
          { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
          { OP_Integer,        0,         1,                 0},    /* 4 */
          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
        };
        int iAddr;
        iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
        sqlite3VdbeChangeP1(v, iAddr, iDb);
        sqlite3VdbeChangeP1(v, iAddr+1, iDb);
        sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
        sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
        sqlite3VdbeChangeP1(v, iAddr+5, iDb);
        sqlite3VdbeUsesBtree(v, iDb);
      }
    }
    break;
  }

#endif

  /*
  **  PRAGMA [database.]incremental_vacuum(N)
  **
  ** Do N steps of incremental vacuuming on a database.
  */
#ifndef SQLITE_OMIT_AUTOVACUUM
  case PragTyp_INCREMENTAL_VACUUM: {
    int iLimit, addr;



    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
      iLimit = 0x7fffffff;
    }
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
    addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
    sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
    sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
    sqlite3VdbeJumpHere(v, addr);
    break;
  }
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
  /*
  **  PRAGMA [database.]cache_size
  **  PRAGMA [database.]cache_size=N
  **
  ** The first form reports the current local setting for the
  ** page cache size. The second form sets the local
  ** page cache size value.  If N is positive then that is the
  ** number of pages in the cache.  If N is negative, then the
  ** number of pages is adjusted so that the cache uses -N kibibytes
  ** of memory.
  */
  case PragTyp_CACHE_SIZE: {

    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( !zRight ){
      returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
    }else{
      int size = sqlite3Atoi(zRight);
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }

  /*
  **  PRAGMA [database.]mmap_size(N)
  **
  ** Used to set mapping size limit. The mapping size limit is
  ** used to limit the aggregate size of all memory mapped regions of the
  ** database file. If this parameter is set to zero, then memory mapping
  ** is not used at all.  If N is negative, then the default memory map
  ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
  ** The parameter N is measured in bytes.
  **
  ** This value is advisory.  The underlying VFS is free to memory map
  ** as little or as much as it wants.  Except, if N is set to 0 then the
  ** upper layers will never invoke the xFetch interfaces to the VFS.
  */
  case PragTyp_MMAP_SIZE: {
    sqlite3_int64 sz;
#if SQLITE_MAX_MMAP_SIZE>0
    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
    if( zRight ){
      int ii;
      sqlite3Atoi64(zRight, &sz, sqlite3Strlen30(zRight), SQLITE_UTF8);
      if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;

#endif
    if( rc==SQLITE_OK ){
      returnSingleInt(pParse, "mmap_size", sz);
    }else if( rc!=SQLITE_NOTFOUND ){
      pParse->nErr++;
      pParse->rc = rc;
    }
    break;
  }

  /*
  **   PRAGMA temp_store
  **   PRAGMA temp_store = "default"|"memory"|"file"
  **
  ** Return or set the local value of the temp_store flag.  Changing
  ** the local value does not make changes to the disk file and the default
  ** value will be restored the next time the database is opened.
  **
  ** Note that it is possible for the library compile-time options to
  ** override this setting
  */
  case PragTyp_TEMP_STORE: {
    if( !zRight ){
      returnSingleInt(pParse, "temp_store", db->temp_store);
    }else{
      changeTempStorage(pParse, zRight);
    }
    break;
  }

  /*
  **   PRAGMA temp_store_directory
  **   PRAGMA temp_store_directory = ""|"directory_name"
  **
  ** Return or set the local value of the temp_store_directory flag.  Changing
  ** the value sets a specific directory to be used for temporary files.
  ** Setting to a null string reverts to the default temporary directory search.
  ** If temporary directory is changed, then invalidateTempStorage.
  **
  */
  case PragTyp_TEMP_STORE_DIRECTORY: {
    if( !zRight ){
      if( sqlite3_temp_directory ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "temp_store_directory", SQLITE_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

      if( zRight[0] ){
        sqlite3_temp_directory = sqlite3_mprintf("%s", zRight);
      }else{
        sqlite3_temp_directory = 0;
      }
#endif /* SQLITE_OMIT_WSD */
    }
    break;
  }

#if SQLITE_OS_WIN
  /*
  **   PRAGMA data_store_directory
  **   PRAGMA data_store_directory = ""|"directory_name"
  **
  ** Return or set the local value of the data_store_directory flag.  Changing
  ** the value sets a specific directory to be used for database files that
  ** were specified with a relative pathname.  Setting to a null string reverts
  ** to the default database directory, which for database files specified with
  ** a relative path will probably be based on the current directory for the
  ** process.  Database file specified with an absolute path are not impacted
  ** by this setting, regardless of its value.
  **
  */
  case PragTyp_DATA_STORE_DIRECTORY: {
    if( !zRight ){
      if( sqlite3_data_directory ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "data_store_directory", SQLITE_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_data_directory, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

      if( zRight[0] ){
        sqlite3_data_directory = sqlite3_mprintf("%s", zRight);
      }else{
        sqlite3_data_directory = 0;
      }
#endif /* SQLITE_OMIT_WSD */
    }
    break;

  }






#endif

#if SQLITE_ENABLE_LOCKING_STYLE
  /*
  **   PRAGMA [database.]lock_proxy_file
  **   PRAGMA [database.]lock_proxy_file = ":auto:"|"lock_file_path"
  **
  ** Return or set the value of the lock_proxy_file flag.  Changing
  ** the value sets a specific file to be used for database access locks.
  **
  */

  case PragTyp_LOCK_PROXY_FILE: {
    if( !zRight ){
      Pager *pPager = sqlite3BtreePager(pDb->pBt);
      char *proxy_file_path = NULL;
      sqlite3_file *pFile = sqlite3PagerFile(pPager);
      sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE, 
                           &proxy_file_path);
      

                                     NULL);
      }
      if( res!=SQLITE_OK ){
        sqlite3ErrorMsg(pParse, "failed to set lock proxy file");
        goto pragma_out;
      }
    }
    break;
  }
#endif /* SQLITE_ENABLE_LOCKING_STYLE */      
    
  /*
  **   PRAGMA [database.]synchronous
  **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
  **
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  case PragTyp_SYNCHRONOUS: {

    if( !zRight ){
      returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
    }else{
      if( !db->autoCommit ){
        sqlite3ErrorMsg(pParse, 
            "Safety level may not be changed inside a transaction");
      }else{
        pDb->safety_level = getSafetyLevel(zRight,0,1)+1;
        setAllPagerFlags(db);
      }
    }
    break;
  }
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

#ifndef SQLITE_OMIT_FLAG_PRAGMAS
  case PragTyp_FLAG: {
    if( zRight==0 ){
      returnSingleInt(pParse, aPragmaNames[mid].zName,
                     (db->flags & aPragmaNames[mid].iArg)!=0 );
    }else{
      int mask = aPragmaNames[mid].iArg;    /* Mask of bits to set or clear. */
      if( db->autoCommit==0 ){
        /* Foreign key support may not be enabled or disabled while not
        ** in auto-commit mode.  */
        mask &= ~(SQLITE_ForeignKeys);
      }

      if( sqlite3GetBoolean(zRight, 0) ){
        db->flags |= mask;
      }else{
        db->flags &= ~mask;
        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
      }

      /* Many of the flag-pragmas modify the code generated by the SQL 
      ** compiler (eg. count_changes). So add an opcode to expire all
      ** compiled SQL statements after modifying a pragma value.
      */
      sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
      setAllPagerFlags(db);
    }
    break;
  }
#endif /* SQLITE_OMIT_FLAG_PRAGMAS */

#ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
  /*
  **   PRAGMA table_info(<table>)
  **
  ** Return a single row for each column of the named table. The columns of
  ** the returned data set are:
  **
  ** cid:        Column id (numbered from left to right, starting at 0)
  ** name:       Column name
  ** type:       Column declaration type.
  ** notnull:    True if 'NOT NULL' is part of column declaration
  ** dflt_value: The default value for the column, if any.
  */
  case PragTyp_TABLE_INFO: if( zRight ){
    Table *pTab;

    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      int i, k;
      int nHidden = 0;
      Column *pCol;
      Index *pPk;
      for(pPk=pTab->pIndex; pPk && pPk->autoIndex!=2; pPk=pPk->pNext){}

        }else{
          for(k=1; ALWAYS(k<=pTab->nCol) && pPk->aiColumn[k-1]!=i; k++){}
        }
        sqlite3VdbeAddOp2(v, OP_Integer, k, 6);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
      }
    }
  }
  break;

  case PragTyp_INDEX_INFO: if( zRight ){
    Index *pIdx;
    Table *pTab;

    pIdx = sqlite3FindIndex(db, zRight, zDb);
    if( pIdx ){
      int i;
      pTab = pIdx->pTable;
      sqlite3VdbeSetNumCols(v, 3);
      pParse->nMem = 3;
      sqlite3CodeVerifySchema(pParse, iDb);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
        assert( pTab->nCol>cnum );
        sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
      }
    }
  }
  break;

  case PragTyp_INDEX_LIST: if( zRight ){
    Index *pIdx;
    Table *pTab;

    int i;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);



      sqlite3VdbeSetNumCols(v, 4);
      pParse->nMem = 4;
      sqlite3CodeVerifySchema(pParse, iDb);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "avgrowsize", SQLITE_STATIC);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, 1);
      sqlite3VdbeAddOp2(v, OP_Null, 0, 2);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, 3);
      sqlite3VdbeAddOp2(v, OP_Integer,
                           (int)sqlite3LogEstToInt(pTab->szTabRow), 4);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
      for(pIdx=pTab->pIndex, i=1; pIdx; pIdx=pIdx->pNext, i++){
        sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
        sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
        sqlite3VdbeAddOp2(v, OP_Integer,

                             (int)sqlite3LogEstToInt(pIdx->szIdxRow), 4);
        sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4);
      }
    }
  }
  break;


  case PragTyp_DATABASE_LIST: {
    int i;

    sqlite3VdbeSetNumCols(v, 3);
    pParse->nMem = 3;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
    }

  }
  break;

  case PragTyp_COLLATION_LIST: {
    int i = 0;
    HashElem *p;
    sqlite3VdbeSetNumCols(v, 2);
    pParse->nMem = 2;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
    }
  }
  break;
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE_OMIT_FOREIGN_KEY
  case PragTyp_FOREIGN_KEY_LIST: if( zRight ){
    FKey *pFK;
    Table *pTab;

    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pFK = pTab->pFKey;
      if( pFK ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 8);

            sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 8);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }
  break;
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER
  case PragTyp_FOREIGN_KEY_CHECK: {
    FKey *pFK;             /* A foreign key constraint */
    Table *pTab;           /* Child table contain "REFERENCES" keyword */
    Table *pParent;        /* Parent table that child points to */
    Index *pIdx;           /* Index in the parent table */
    int i;                 /* Loop counter:  Foreign key number for pTab */
    int j;                 /* Loop counter:  Field of the foreign key */
    HashElem *k;           /* Loop counter:  Next table in schema */
    int x;                 /* result variable */
    int regResult;         /* 3 registers to hold a result row */
    int regKey;            /* Register to hold key for checking the FK */
    int regRow;            /* Registers to hold a row from pTab */
    int addrTop;           /* Top of a loop checking foreign keys */
    int addrOk;            /* Jump here if the key is OK */
    int *aiCols;           /* child to parent column mapping */


    regResult = pParse->nMem+1;
    pParse->nMem += 4;
    regKey = ++pParse->nMem;
    regRow = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);
    sqlite3VdbeSetNumCols(v, 4);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "table", SQLITE_STATIC);

        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
        sqlite3VdbeResolveLabel(v, addrOk);
        sqlite3DbFree(db, aiCols);
      }
      sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1);
      sqlite3VdbeJumpHere(v, addrTop);
    }
  }
  break;
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

#ifndef NDEBUG
  case PragTyp_PARSER_TRACE: {
    if( zRight ){
      if( sqlite3GetBoolean(zRight, 0) ){
        sqlite3ParserTrace(stderr, "parser: ");
      }else{
        sqlite3ParserTrace(0, 0);
      }
    }
  }
  break;
#endif

  /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
  ** used will be case sensitive or not depending on the RHS.
  */
  case PragTyp_CASE_SENSITIVE_LIKE: {
    if( zRight ){
      sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight, 0));
    }
  }
  break;

#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  /* Pragma "quick_check" is reduced version of 
  ** integrity_check designed to detect most database corruption
  ** without most of the overhead of a full integrity-check.
  */
  case PragTyp_INTEGRITY_CHECK: {


    int i, j, addr, mxErr;

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const VdbeOpList endCode[] = {

    ** to -1 here, to indicate that the VDBE should verify the integrity
    ** of all attached databases.  */
    assert( iDb>=0 );
    assert( iDb==0 || pId2->z );
    if( pId2->z==0 ) iDb = -1;

    /* Initialize the VDBE program */

    pParse->nMem = 6;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", SQLITE_STATIC);

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){

#endif /* SQLITE_OMIT_BTREECOUNT */
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP2(v, addr, -mxErr);
    sqlite3VdbeJumpHere(v, addr+1);
    sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
  }
  break;
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
  **

  ** the main database has not been initialized and/or created when ATTACH
  ** is executed, this is done before the ATTACH operation.
  **
  ** In the second form this pragma sets the text encoding to be used in
  ** new database files created using this database handle. It is only
  ** useful if invoked immediately after the main database i
  */
  case PragTyp_ENCODING: {
    static const struct EncName {
      char *zName;
      u8 enc;
    } encnames[] = {
      { "UTF8",     SQLITE_UTF8        },
      { "UTF-8",    SQLITE_UTF8        },  /* Must be element [1] */
      { "UTF-16le", SQLITE_UTF16LE     },  /* Must be element [2] */

          }
        }
        if( !pEnc->zName ){
          sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
        }
      }
    }
  }
  break;
#endif /* SQLITE_OMIT_UTF16 */

#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
  /*
  **   PRAGMA [database.]schema_version
  **   PRAGMA [database.]schema_version = <integer>
  **

  ** Subverting this mechanism by using "PRAGMA schema_version" to modify
  ** the schema-version is potentially dangerous and may lead to program
  ** crashes or database corruption. Use with caution!
  **
  ** The user-version is not used internally by SQLite. It may be used by
  ** applications for any purpose.
  */
  case PragTyp_HEADER_VALUE: {




    int iCookie;   /* Cookie index. 1 for schema-cookie, 6 for user-cookie. */
    sqlite3VdbeUsesBtree(v, iDb);
    switch( zLeft[0] ){
      case 'a': case 'A':
        iCookie = BTREE_APPLICATION_ID;
        break;
      case 'f': case 'F':

      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, iDb);
      sqlite3VdbeChangeP3(v, addr+1, iCookie);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
    }
  }
  break;
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
  /*
  **   PRAGMA compile_options
  **
  ** Return the names of all compile-time options used in this build,
  ** one option per row.
  */
  case PragTyp_COMPILE_OPTIONS: {
    int i = 0;
    const char *zOpt;
    sqlite3VdbeSetNumCols(v, 1);
    pParse->nMem = 1;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
    while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
      sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }
  }
  break;
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

#ifndef SQLITE_OMIT_WAL
  /*
  **   PRAGMA [database.]wal_checkpoint = passive|full|restart
  **
  ** Checkpoint the database.
  */
  case PragTyp_WAL_CHECKPOINT: {
    int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);
    int eMode = SQLITE_CHECKPOINT_PASSIVE;
    if( zRight ){
      if( sqlite3StrICmp(zRight, "full")==0 ){
        eMode = SQLITE_CHECKPOINT_FULL;
      }else if( sqlite3StrICmp(zRight, "restart")==0 ){
        eMode = SQLITE_CHECKPOINT_RESTART;
      }
    }

    sqlite3VdbeSetNumCols(v, 3);
    pParse->nMem = 3;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "busy", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "log", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "checkpointed", SQLITE_STATIC);

    sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
  }
  break;

  /*
  **   PRAGMA wal_autocheckpoint
  **   PRAGMA wal_autocheckpoint = N
  **
  ** Configure a database connection to automatically checkpoint a database
  ** after accumulating N frames in the log. Or query for the current value
  ** of N.
  */
  case PragTyp_WAL_AUTOCHECKPOINT: {
    if( zRight ){
      sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));
    }
    returnSingleInt(pParse, "wal_autocheckpoint", 
       db->xWalCallback==sqlite3WalDefaultHook ? 
           SQLITE_PTR_TO_INT(db->pWalArg) : 0);
  }
  break;
#endif

  /*
  **  PRAGMA shrink_memory
  **
  ** This pragma attempts to free as much memory as possible from the
  ** current database connection.
  */
  case PragTyp_SHRINK_MEMORY: {
    sqlite3_db_release_memory(db);
    break;
  }

  /*
  **   PRAGMA busy_timeout
  **   PRAGMA busy_timeout = N
  **
  ** Call sqlite3_busy_timeout(db, N).  Return the current timeout value
  ** if one is set.  If no busy handler or a different busy handler is set
  ** then 0 is returned.  Setting the busy_timeout to 0 or negative
  ** disables the timeout.
  */
  /*case PragTyp_BUSY_TIMEOUT*/ default: {
    assert( aPragmaNames[mid].ePragTyp==PragTyp_BUSY_TIMEOUT );
    if( zRight ){
      sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
    }
    returnSingleInt(pParse, "timeout",  db->busyTimeout);
    break;
  }

  /*
  **   PRAGMA soft_heap_limit
  **   PRAGMA soft_heap_limit = N
  **
  ** Call sqlite3_soft_heap_limit64(N).  Return the result.  If N is omitted,
  ** use -1.
  */
  case PragTyp_SOFT_HEAP_LIMIT: {
    sqlite3_int64 N;
    if( zRight && sqlite3Atoi64(zRight, &N, 1000000, SQLITE_UTF8)==SQLITE_OK ){
      sqlite3_soft_heap_limit64(N);
    }
    returnSingleInt(pParse, "soft_heap_limit",  sqlite3_soft_heap_limit64(-1));
    break;
  }

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
  */
  case PragTyp_LOCK_STATUS: {
    static const char *const azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    sqlite3VdbeSetNumCols(v, 2);
    pParse->nMem = 2;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", SQLITE_STATIC);

      }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
    }
    break;
  }

#endif

#ifdef SQLITE_HAS_CODEC
  case PragTyp_KEY: {
    if( zRight ) sqlite3_key_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
    break;

  }
  case PragTyp_REKEY: {
    if( zRight ) sqlite3_rekey_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
    break;
  }
  case PragTyp_HEXKEY: {
    if( zRight ){

      u8 iByte;
      int i;
      char zKey[40];
      for(i=0, iByte=0; i<sizeof(zKey)*2 && sqlite3Isxdigit(zRight[i]); i++){
        iByte = (iByte<<4) + sqlite3HexToInt(zRight[i]);


        if( (i&1)!=0 ) zKey[i/2] = iByte;
      }
      if( (zLeft[3] & 0xf)==0xb ){
        sqlite3_key_v2(db, zDb, zKey, i/2);
      }else{
        sqlite3_rekey_v2(db, zDb, zKey, i/2);
      }
    }
    break;
  }
#endif
#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
  case PragTyp_ACTIVATE_EXTENSIONS: if( zRight ){
#ifdef SQLITE_HAS_CODEC
    if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
      sqlite3_activate_see(&zRight[4]);
    }
#endif
#ifdef SQLITE_ENABLE_CEROD
    if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
      sqlite3_activate_cerod(&zRight[6]);
    }
#endif
  }
  break;
#endif

  } /* End of the PRAGMA switch */


pragma_out:
  sqlite3DbFree(db, zLeft);
  sqlite3DbFree(db, zRight);
}

#endif /* SQLITE_OMIT_PRAGMA */

  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;
    ExprSetProperty(pDup, EP_Skip);
    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);

  */
  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->flags |= EP_MemToken;
  }
  sqlite3DbFree(db, pDup);
}


/*
** Return TRUE if the name zCol occurs anywhere in the USING clause.

  struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */
  NameContext *pTopNC = pNC;        /* First namecontext in the list */
  Schema *pSchema = 0;              /* Schema of the expression */
  int isTrigger = 0;

  assert( pNC );     /* the name context cannot be NULL. */
  assert( zCol );    /* The Z in X.Y.Z cannot be NULL */
  assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );

  /* Initialize the node to no-match */
  pExpr->iTable = -1;
  pExpr->pTab = 0;
  ExprSetVVAProperty(pExpr, EP_NoReduce);

  /* Translate the schema name in zDb into a pointer to the corresponding
  ** schema.  If not found, pSchema will remain NULL and nothing will match
  ** resulting in an appropriate error message toward the end of this routine
  */
  if( zDb ){
    testcase( pNC->ncFlags & NC_PartIdx );

    sqlite3ErrorMsg(pParse,"%s prohibited in CHECK constraints", zMsg);
  }
}
#else
# define notValidCheckConstraint(P,N,M)
#endif

/*
** Expression p should encode a floating point value between 1.0 and 0.0.
** Return 1024 times this value.  Or return -1 if p is not a floating point
** value between 1.0 and 0.0.
*/
static int exprProbability(Expr *p){
  double r = -1.0;
  if( p->op!=TK_FLOAT ) return -1;
  sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);
  assert( r>=0.0 );
  if( r>1.0 ) return -1;
  return (int)(r*1000.0);
}

/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree.  Return 0 to continue the search down
** the tree or 2 to abort the tree walk.

  Parse *pParse;

  pNC = pWalker->u.pNC;
  assert( pNC!=0 );
  pParse = pNC->pParse;
  assert( pParse==pWalker->pParse );

  if( ExprHasProperty(pExpr, EP_Resolved) ) return WRC_Prune;
  ExprSetProperty(pExpr, EP_Resolved);
#ifndef NDEBUG
  if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
    SrcList *pSrcList = pNC->pSrcList;
    int i;
    for(i=0; i<pNC->pSrcList->nSrc; i++){
      assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);

        if( pDef==0 ){
          no_such_func = 1;
        }else{
          wrong_num_args = 1;
        }
      }else{
        is_agg = pDef->xFunc==0;
        if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
          ExprSetProperty(pExpr, EP_Unlikely|EP_Skip);
          if( n==2 ){
            pExpr->iTable = exprProbability(pList->a[1].pExpr);
            if( pExpr->iTable<0 ){
              sqlite3ErrorMsg(pParse, "second argument to likelihood() must be a "
                                      "constant between 0.0 and 1.0");
              pNC->nErr++;
            }
          }else{
            pExpr->iTable = 62;  /* TUNING:  Default 2nd arg to unlikely() is 0.0625 */
          }             
        }
      }
#ifndef SQLITE_OMIT_AUTHORIZATION
      if( pDef ){
        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
        if( auth!=SQLITE_OK ){
          if( auth==SQLITE_DENY ){
            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",

  pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
  pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);

  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
  if( pEq && isOuterJoin ){
    ExprSetProperty(pEq, EP_FromJoin);
    assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
    ExprSetVVAProperty(pEq, EP_NoReduce);
    pEq->iRightJoinTable = (i16)pE2->iTable;
  }
  *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq);
}

/*
** Set the EP_FromJoin property on all terms of the given expression.

** defer the handling of t1.x=5, it will be processed immediately
** after the t1 loop and rows with t1.x!=5 will never appear in
** the output, which is incorrect.
*/
static void setJoinExpr(Expr *p, int iTable){
  while( p ){
    ExprSetProperty(p, EP_FromJoin);
    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
    ExprSetVVAProperty(p, EP_NoReduce);
    p->iRightJoinTable = (i16)iTable;
    setJoinExpr(p->pLeft, iTable);
    p = p->pRight;
  } 
}

/*

    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
  }
}

/*
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
**
** Also try to estimate the size of the returned value and return that
** result in *pEstWidth.
**
** The declaration type is the exact datatype definition extracted from the
** original CREATE TABLE statement if the expression is a column. The
** declaration type for a ROWID field is INTEGER. Exactly when an expression
** is considered a column can be complex in the presence of subqueries. The
** result-set expression in all of the following SELECT statements is 
** considered a column by this function.
**
**   SELECT col FROM tbl;
**   SELECT (SELECT col FROM tbl;
**   SELECT (SELECT col FROM tbl);
**   SELECT abc FROM (SELECT col AS abc FROM tbl);
** 
** The declaration type for any expression other than a column is NULL.
**
** This routine has either 3 or 6 parameters depending on whether or not
** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.
*/
#ifdef SQLITE_ENABLE_COLUMN_METADATA
# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,C,D,E,F)
static const char *columnTypeImpl(
  NameContext *pNC, 
  Expr *pExpr,
  const char **pzOrigDb,
  const char **pzOrigTab,
  const char **pzOrigCol,
  u8 *pEstWidth
){
  char const *zOrigDb = 0;
  char const *zOrigTab = 0;
  char const *zOrigCol = 0;
#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F)
static const char *columnTypeImpl(
  NameContext *pNC, 
  Expr *pExpr,
  u8 *pEstWidth
){
#endif /* !defined(SQLITE_ENABLE_COLUMN_METADATA) */
  char const *zType = 0;
  int j;

  u8 estWidth = 1;

  if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0;
  switch( pExpr->op ){
    case TK_AGG_COLUMN:
    case TK_COLUMN: {
      /* The expression is a column. Locate the table the column is being
      ** extracted from in NameContext.pSrcList. This table may be real
      ** database table or a subquery.
      */

          ** test case misc2.2.2) - it always evaluates to NULL.
          */
          NameContext sNC;
          Expr *p = pS->pEList->a[iCol].pExpr;
          sNC.pSrcList = pS->pSrc;
          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 
        }
      }else if( ALWAYS(pTab->pSchema) ){
        /* A real table */
        assert( !pS );
        if( iCol<0 ) iCol = pTab->iPKey;
        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
#ifdef SQLITE_ENABLE_COLUMN_METADATA
        if( iCol<0 ){
          zType = "INTEGER";
          zOrigCol = "rowid";
        }else{
          zType = pTab->aCol[iCol].zType;
          zOrigCol = pTab->aCol[iCol].zName;
          estWidth = pTab->aCol[iCol].szEst;
        }
        zOrigTab = pTab->zName;
        if( pNC->pParse ){
          int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
          zOrigDb = pNC->pParse->db->aDb[iDb].zName;
        }
#else
        if( iCol<0 ){
          zType = "INTEGER";
        }else{
          zType = pTab->aCol[iCol].zType;
          estWidth = pTab->aCol[iCol].szEst;
        }
#endif
      }
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT: {
      /* The expression is a sub-select. Return the declaration type and
      ** origin info for the single column in the result set of the SELECT
      ** statement.
      */
      NameContext sNC;
      Select *pS = pExpr->x.pSelect;
      Expr *p = pS->pEList->a[0].pExpr;
      assert( ExprHasProperty(pExpr, EP_xIsSelect) );
      sNC.pSrcList = pS->pSrc;
      sNC.pNext = pNC;
      sNC.pParse = pNC->pParse;
      zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, &estWidth); 
      break;
    }
#endif
  }

#ifdef SQLITE_ENABLE_COLUMN_METADATA  
  if( pzOrigDb ){
    assert( pzOrigTab && pzOrigCol );
    *pzOrigDb = zOrigDb;
    *pzOrigTab = zOrigTab;
    *pzOrigCol = zOrigCol;
  }
#endif
  if( pEstWidth ) *pEstWidth = estWidth;
  return zType;
}

/*
** Generate code that will tell the VDBE the declaration types of columns
** in the result set.
*/

  for(i=0; i<pEList->nExpr; i++){
    Expr *p = pEList->a[i].pExpr;
    const char *zType;
#ifdef SQLITE_ENABLE_COLUMN_METADATA
    const char *zOrigDb = 0;
    const char *zOrigTab = 0;
    const char *zOrigCol = 0;
    zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, 0);

    /* The vdbe must make its own copy of the column-type and other 
    ** column specific strings, in case the schema is reset before this
    ** virtual machine is deleted.
    */
    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);
#else
    zType = columnType(&sNC, p, 0, 0, 0, 0);
#endif
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
  }
#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
}

/*
** Generate code that will tell the VDBE the names of columns
** in the result set.  This information is used to provide the
** azCol[] values in the callback.
*/

** routine goes through and adds the types and collations.
**
** This routine requires that all identifiers in the SELECT
** statement be resolved.
*/
static void selectAddColumnTypeAndCollation(
  Parse *pParse,        /* Parsing contexts */
  Table *pTab,          /* Add column type information to this table */

  Select *pSelect       /* SELECT used to determine types and collations */
){
  sqlite3 *db = pParse->db;
  NameContext sNC;
  Column *pCol;
  CollSeq *pColl;
  int i;
  Expr *p;
  struct ExprList_item *a;
  u64 szAll = 0;

  assert( pSelect!=0 );
  assert( (pSelect->selFlags & SF_Resolved)!=0 );
  assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );
  if( db->mallocFailed ) return;
  memset(&sNC, 0, sizeof(sNC));
  sNC.pSrcList = pSelect->pSrc;
  a = pSelect->pEList->a;
  for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
    p = a[i].pExpr;
    pCol->zType = sqlite3DbStrDup(db, columnType(&sNC, p,0,0,0, &pCol->szEst));
    szAll += pCol->szEst;
    pCol->affinity = sqlite3ExprAffinity(p);
    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_NONE;
    pColl = sqlite3ExprCollSeq(pParse, p);
    if( pColl ){
      pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
    }
  }
  pTab->szTabRow = sqlite3LogEst(szAll*4);
}

/*
** Given a SELECT statement, generate a Table structure that describes
** the result set of that SELECT.
*/
Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){

    return 0;
  }
  /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
  ** is disabled */
  assert( db->lookaside.bEnabled==0 );
  pTab->nRef = 1;
  pTab->zName = 0;
  pTab->nRowEst = 1048576;
  selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
  selectAddColumnTypeAndCollation(pParse, pTab, pSelect);
  pTab->iPKey = -1;
  if( db->mallocFailed ){
    sqlite3DeleteTable(db, pTab);
    return 0;
  }
  return pTab;
}

  pTab = p->pSrc->a[0].pTab;
  pExpr = p->pEList->a[0].pExpr;
  assert( pTab && !pTab->pSelect && pExpr );

  if( IsVirtual(pTab) ) return 0;
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
  if( NEVER(pAggInfo->nFunc==0) ) return 0;
  if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
  if( pExpr->flags&EP_Distinct ) return 0;

  return pTab;
}

/*
** If the source-list item passed as an argument was augmented with an

      /* A sub-query in the FROM clause of a SELECT */
      assert( pSel!=0 );
      assert( pFrom->pTab==0 );
      sqlite3WalkSelect(pWalker, pSel);
      pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
      if( pTab==0 ) return WRC_Abort;
      pTab->nRef = 1;
      pTab->zName = sqlite3MPrintf(db, "sqlite_sq_%p", (void*)pTab);
      while( pSel->pPrior ){ pSel = pSel->pPrior; }
      selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol);
      pTab->iPKey = -1;
      pTab->nRowEst = 1048576;
      pTab->tabFlags |= TF_Ephemeral;
#endif
    }else{
      /* An ordinary table or view name in the FROM clause */
      assert( pFrom->pTab==0 );
      pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
      if( pTab==0 ) return WRC_Abort;

    for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
      Table *pTab = pFrom->pTab;
      if( ALWAYS(pTab!=0) && (pTab->tabFlags & TF_Ephemeral)!=0 ){
        /* A sub-query in the FROM clause of a SELECT */
        Select *pSel = pFrom->pSelect;
        assert( pSel );
        while( pSel->pPrior ) pSel = pSel->pPrior;
        selectAddColumnTypeAndCollation(pParse, pTab, pSel);
      }
    }
  }
  return WRC_Continue;
}
#endif

      regAgg = 0;
    }
    if( pF->iDistinct>=0 ){
      addrNext = sqlite3VdbeMakeLabel(v);
      assert( nArg==1 );
      codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
    }
    if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
      CollSeq *pColl = 0;
      struct ExprList_item *pItem;
      int j;
      assert( pList!=0 );  /* pList!=0 if pF->pFunc has NEEDCOLL */
      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
      }

        KeyInfo *pKeyInfo = 0;               /* Keyinfo for scanned index */
        Index *pBest = 0;                    /* Best index found so far */
        int iRoot = pTab->tnum;              /* Root page of scanned b-tree */

        sqlite3CodeVerifySchema(pParse, iDb);
        sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

        /* Search for the index that has the lowest scan cost.






        **
        ** (2011-04-15) Do not do a full scan of an unordered index.
        **
        ** (2013-10-03) Do not count the entires in a partial index.
        **
        ** In practice the KeyInfo structure will not be used. It is only 
        ** passed to keep OP_OpenRead happy.
        */
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          if( pIdx->bUnordered==0
           && pIdx->szIdxRow<pTab->szTabRow
           && pIdx->pPartIdxWhere==0
           && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
          ){
            pBest = pIdx;
          }
        }
        if( pBest ){
          iRoot = pBest->tnum;
          pKeyInfo = sqlite3IndexKeyinfo(pParse, pBest);
        }

        /* Open a read-only cursor, execute the OP_Count, close the cursor. */
        sqlite3VdbeAddOp3(v, OP_OpenRead, iCsr, iRoot, iDb);
        if( pKeyInfo ){