SQLite4  Check-in Differences

OPTS += -DHAVE_GMTIME_R
OPTS += -DHAVE_LOCALTIME_R
OPTS += -DHAVE_MALLOC_USABLE_SIZE
OPTS += -DHAVE_USLEEP
#OPTS += -DSQLITE4_MEMDEBUG=1
#OPTS += -DSQLITE4_NO_SYNC=1 -DLSM_NO_SYNC=1
#OPTS += -DSQLITE4_OMIT_ANALYZE
#OPTS += -DSQLITE4_OMIT_AUTOMATIC_INDEX
OPTS += -DSQLITE4_OMIT_AUTOMATIC_INDEX
OPTS += -DSQLITE4_OMIT_VIRTUALTABLE=1
OPTS += -DSQLITE4_OMIT_XFER_OPT
OPTS += -DSQLITE4_THREADSAFE=0

# This is how we compile
#
TCCX =  $(TCC) $(OPTS) -I. -I$(TOP)/src -I$(TOP) 

          "sql = CASE "
            "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
            "ELSE sqlite_rename_table(sql, %Q) END, "
#endif
          "tbl_name = %Q, "
          "name = CASE "
            "WHEN type='table' THEN %Q "
            "WHEN name LIKE 'sqlite_%%_unique%%' AND type='index' THEN "
             "'sqlite_' || %Q || substr(name,%d+8) "
            "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
             "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
            "ELSE name END "
      "WHERE tbl_name=%Q AND "
          "(type='table' OR type='index' OR type='trigger');", 
      zDb, SCHEMA_TABLE(iDb), zName, zName, zName, 
#ifndef SQLITE4_OMIT_TRIGGER
      zName,
#endif

    pDflt = 0;
  }

  /* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
  ** If there is a NOT NULL constraint, then the default value for the
  ** column must not be NULL.
  */
  if( pCol->iPrimKey>0 ){
  if( pCol->isPrimKey ){
    sqlite4ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
    return;
  }
  if( pNew->pIndex ){
    sqlite4ErrorMsg(pParse, "Cannot add a UNIQUE column");
    return;
  }

** If the sqlite_stat1.idx column is NULL, then the sqlite_stat1.stat
** column contains a single integer which is the (estimated) number of
** rows in the table identified by sqlite_stat1.tbl.
**
** Format for sqlite_stat3:
**
** The sqlite_stat3 table may contain multiple entries for each index.
** The idx column names the index and the tbl column contains the name
** of the indexed table. If the idx and tbl columns are the same, then the 
** sample is of the PRIMARY KEY index. The sample column is a value taken 
** from the left-most column of the index encoded using the key-encoding. 
** The nEq column is the approximate number of entires in the index whose 
** left-most column exactly matches the sample. nLt is the approximate 
** number of entires whose left-most column is less than the sample. The 
** nDLt column is the approximate number of distinct left-most entries in 
** the index that are less than the sample.
** The idx column names the index and the tbl column is the table of the
** index.  If the idx and tbl columns are the same, then the sample is
** of the INTEGER PRIMARY KEY.  The sample column is a value taken from
** the left-most column of the index.  The nEq column is the approximate
** number of entires in the index whose left-most column exactly matches
** the sample.  nLt is the approximate number of entires whose left-most
** column is less than the sample.  The nDLt column is the approximate
** number of distinct left-most entries in the index that are less than
** the sample.
**
** Future versions of SQLite might change to store a string containing
** multiple integers values in the nDLt column of sqlite_stat3.  The first
** integer will be the number of prior index entries that are distinct in
** the left-most column.  The second integer will be the number of prior index
** entries that are distinct in the first two columns.  The third integer
** will be the number of prior index entries that are distinct in the first

      aRoot[i] = pPK->tnum;
      assert( aRoot[i]>0 );
      if( zWhere ){
        sqlite4NestedParse(pParse,
           "DELETE FROM %Q.%s WHERE %s=%Q", pDb->zName, zTab, zWhereType, zWhere
        );
      }else{
        /* The sqlite_stat[13] table already exists.  Delete all rows. */
        /* The sqlite_stat[12] table already exists.  Delete all rows. */
        sqlite4VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);
      }
    }
  }

  /* Open the sqlite_stat[13] tables for writing. */
  for(i=0; i<ArraySize(aTable); i++){

  int mxSample;             /* Maximum number of samples to accumulate */
  int nSample;              /* Current number of samples */
  u32 iPrn;                 /* Pseudo-random number used for sampling */
  struct Stat3Sample {
    void *pKey;                /* Index key for this sample */
    int nKey;                  /* Bytes of pKey in use */
    int nAlloc;                /* Bytes of space allocated at pKey */

    tRowcnt nEq;               /* sqlite_stat3.nEq */
    tRowcnt nLt;               /* sqlite_stat3.nLt */
    tRowcnt nDLt;              /* sqlite_stat3.nDLt */
    u8 isPSample;              /* True if a periodic sample */
    u32 iHash;                 /* Tiebreaker value (pseudo-random) */
    u32 iHash;                 /* Tiebreaker hash */
  } *a;                     /* An array of samples */
};

#ifdef SQLITE4_ENABLE_STAT3

/*
** Delete a Stat3Accum object.
*/
static void delStat3Accum(void *pCtx, void *pDel){
static void delStat3Accum(void *pCtx, void *p){
  sqlite4 *db = (sqlite4*)pCtx;
  Stat3Accum *p = (Stat3Accum*)pDel;
  int i;

  for(i=0; i<p->nSample; i++){
    sqlite4DbFree(db, p->a[i].pKey);
  }
  sqlite4DbFree(db, p);
}

/*
** Implementation of the stat3_init(C,S) SQL function.  The two parameters
** are the number of rows in the table or index (C) and the number of samples
** to accumulate (S).

  }else{
    if( nEq>p->a[iMin].nEq || (nEq==p->a[iMin].nEq && h>p->a[iMin].iHash) ){
      doInsert = 1;
    }
  }
  if( !doInsert ) return;
  if( p->nSample==p->mxSample ){
    void *pKey = p->a[iMin].pKey;
    int nAlloc = p->a[iMin].nAlloc;
    assert( p->nSample - iMin - 1 >= 0 );
    memmove(&p->a[iMin], &p->a[iMin+1], sizeof(p->a[0])*(p->nSample-iMin-1));
    pSample = &p->a[p->nSample-1];
    memset(pSample, 0, sizeof(struct Stat3Sample));
    pSample->pKey = pKey;
    pSample->nAlloc = nAlloc;
  }else{
    pSample = &p->a[p->nSample++];
  }

  pKey = sqlite4_value_blob(argv[3], &nKey);
  if( nKey>pSample->nAlloc ){
    sqlite4 *db = sqlite4_context_db_handle(context);

  0,                /* xStep */
  0,                /* xFinalize */
  "stat3_get",      /* zName */
  0,                /* pHash */
  0                 /* pDestructor */
};
#endif /* SQLITE4_ENABLE_STAT3 */




/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
  Parse *pParse,   /* Parser context */

#endif

  iIdxCur = pParse->nTab++;
  sqlite4VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    int nCol;
    KeyInfo *pKey;
    int *aChngAddr;              /* Array of jump instruction addresses */
    int regCnt;                  /* Total number of rows in table. */
    int regPrev;                 /* Previous index key read from database */
    int aregCard;                /* Cardinality array registers */
#ifdef SQLITE4_ENABLE_STAT3
    int addrAddimm;              /* Address at top of stat3 output loop */
    int addrIsnull;              /* Another address within the stat3 loop */
#endif

    if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
    VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName));
    nCol = pIdx->nColumn;
    aChngAddr = sqlite4DbMallocRaw(db, sizeof(int)*nCol);
    if( aChngAddr==0 ) continue;
    pKey = sqlite4IndexKeyinfo(pParse, pIdx);
    if( iMem+1+(nCol*2)>pParse->nMem ){
      pParse->nMem = iMem+1+(nCol*2);
    }

    /* Open a cursor to the index to be analyzed. */
    assert( iDb==sqlite4SchemaToIndex(db, pIdx->pSchema) );

    */
    regCnt = iMem;
    regPrev = iMem+1;
    aregCard = iMem+2;

    sqlite4VdbeAddOp2(v, OP_Integer, 0, regCnt);
    sqlite4VdbeAddOp2(v, OP_Null, 0, regPrev);
#ifdef SQLITE4_ENABLE_STAT3
    sqlite4VdbeAddOp2(v, OP_Null, 0, regSample);
#endif
    for(i=0; i<nCol; i++){
      sqlite4VdbeAddOp2(v, OP_Integer, 1, aregCard+i);
    }

    /* Start the analysis loop. This loop runs through all the entries in
    ** the index b-tree.  */
    endOfLoop = sqlite4VdbeMakeLabel(v);

  sqlite4VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
  sqlite4VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
  sqlite4VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
  sqlite4VdbeChangeP5(v, OPFLAG_APPEND);
  if( pParse->nMem<regRec ) pParse->nMem = regRec;
  sqlite4VdbeJumpHere(v, jZeroRows);
}


/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
  Vdbe *v = sqlite4GetVdbe(pParse);

    Schema *pSchema;
    HashElem *p;
    int maxTab = 1;

    pSchema = pParse->db->aDb[iDb].pSchema;
    for(p=sqliteHashFirst(&pSchema->idxHash); p;p=sqliteHashNext(p)){
      Index *pIdx = (Index*)sqliteHashData(p);
      if( pIdx->tnum!=KVSTORE_ROOT && pIdx->tnum > maxTab ) maxTab = pIdx->tnum;
      if( pIdx->tnum > maxTab ) maxTab = pIdx->tnum;
    }

    pParse->iNewidxReg = ++pParse->nMem;
    sqlite4VdbeAddOp2(v, OP_Integer, maxTab, pParse->iNewidxReg);
  }

  sqlite4VdbeAddOp2(v, OP_NewIdxid, pParse->iNewidxReg, iDb);

    {
      int tnum = firstAvailableTableNumber(db, iDb);
      sqlite4VdbeAddOp2(v, OP_Integer, tnum, reg2);
    }
#endif
    sqlite4OpenMasterTable(pParse, iDb);
    sqlite4VdbeAddOp2(v, OP_NewRowid, 0, reg1);
    sqlite4VdbeAddOp2(v, OP_Null, 0, reg3);
    sqlite4VdbeAddOp3(v, OP_Insert, 0, 0, reg1);
    sqlite4VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
    sqlite4VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite4VdbeAddOp0(v, OP_Close);
  }

  /* Normal (non-error) return. */
  return;

    sqlite4ErrorMsg(pParse, 
      "table \"%s\" has more than one primary key", pTab->zName);
    goto primary_key_exit;
  }
  pTab->tabFlags |= TF_HasPrimaryKey;
  if( pList==0 ){
    iCol = pTab->nCol - 1;
    pTab->aCol[iCol].iPrimKey = 1;
    pTab->aCol[iCol].isPrimKey = 1;
    pTab->aCol[iCol].notNull = 1;
  }else{
    for(i=0; i<pList->nExpr; i++){
      for(iCol=0; iCol<pTab->nCol; iCol++){
        if( sqlite4_stricmp(pList->a[i].zName, pTab->aCol[iCol].zName)==0 ){
          break;
        }
      }
      if( iCol<pTab->nCol ){
        pTab->aCol[iCol].iPrimKey = i+1;
        pTab->aCol[iCol].isPrimKey = i+1;
        pTab->aCol[iCol].notNull = 1;
      }
    }
    if( pList->nExpr>1 ) iCol = -1;
  }
  pPk = sqlite4CreateIndex(pParse, 0, pList, 0, onError, 0, sortOrder, 1);
  pPk = sqlite4CreateIndex(
     pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0, 1
  );

  if( iCol>=0 && iCol<pTab->nCol
   && (zType = pTab->aCol[iCol].zType)!=0
   && sqlite4_stricmp(zType, "INTEGER")==0
   && sortOrder==SQLITE4_SO_ASC
   && pPk
  ){

}

static Index *newIndex(
  Parse *pParse,                  /* Parse context for current statement */
  Table *pTab,                    /* Table index is created on */
  const char *zName,              /* Name of index object to create */
  int nCol,                       /* Number of columns in index */
  int nCover,                     /* Number of covered columns in index */
  int onError,                    /* One of OE_Abort, OE_Replace etc. */
  int nExtra,                     /* Bytes of extra space to allocate */
  char **pzExtra                  /* OUT: Pointer to extra space */
){
  sqlite4 *db = pParse->db;       /* Database handle */
  Index *pIndex;                  /* Return value */
  char *zExtra = 0;               /* nExtra bytes of extra space allocated */
  int nName;                      /* Length of zName in bytes */

  /* Allocate the index structure. */
  nName = sqlite4Strlen30(zName);
  pIndex = sqlite4DbMallocZero(db, 
      ROUND8(sizeof(Index)) +              /* Index structure  */
      ROUND8(sizeof(tRowcnt)*(nCol+1)) +   /* Index.aiRowEst   */
      sizeof(char *)*nCol +                /* Index.azColl     */
      sizeof(int)*nCol +                   /* Index.aiColumn   */
      sizeof(int)*nCover +                 /* Index.aiCover    */
      sizeof(u8)*nCol +                    /* Index.aSortOrder */
      nName + 1 +                          /* Index.zName      */
      nExtra                               /* Collation sequence names */
  );
  assert( pIndex || db->mallocFailed );

  if( pIndex ){
    zExtra = (char*)pIndex;
    pIndex->aiRowEst = (tRowcnt*)&zExtra[ROUND8(sizeof(Index))];
    pIndex->azColl = (char**)
      ((char*)pIndex->aiRowEst + ROUND8(sizeof(tRowcnt)*nCol+1));
    assert( EIGHT_BYTE_ALIGNMENT(pIndex->aiRowEst) );
    assert( EIGHT_BYTE_ALIGNMENT(pIndex->azColl) );
    pIndex->aiColumn = (int *)(&pIndex->azColl[nCol]);
    pIndex->aiCover = (int *)(&pIndex->aiColumn[nCol]);
    pIndex->aSortOrder = (u8 *)(&pIndex->aiCover[nCover]);
    pIndex->aSortOrder = (u8 *)(&pIndex->aiColumn[nCol]);
    pIndex->zName = (char *)(&pIndex->aSortOrder[nCol]);
    zExtra = (char *)(&pIndex->zName[nName+1]);
    memcpy(pIndex->zName, zName, nName+1);
    pIndex->pTable = pTab;
    pIndex->nColumn = nCol;
    pIndex->nCover = nCover;
    pIndex->onError = (u8)onError;
    pIndex->pSchema = pTab->pSchema;

  }

  *pzExtra = zExtra;
  return pIndex;
}

static int addIndexToHash(sqlite4 *db, Index *pIdx){

){
  sqlite4 *db = pParse->db;
  Index *pIndex;                  /* New index */
  char *zExtra;

  assert( !pTab->pIndex || pTab->pIndex->eIndexType!=SQLITE4_INDEX_PRIMARYKEY );
  assert( sqlite4Strlen30("binary")==6 );
  pIndex = newIndex(pParse, pTab, pTab->zName, 1, 0, OE_Abort, 1+6, &zExtra);
  pIndex = newIndex(pParse, pTab, pTab->zName, 1, OE_Abort, 1+6, &zExtra);
  if( pIndex && addIndexToHash(db, pIndex) ){
    sqlite4DbFree(db, pIndex);
    pIndex = 0;
  }
  if( pIndex ){
    pIndex->aiColumn[0] = -1;
    pIndex->azColl[0] = zExtra;

  FKey *pFKey;
  if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
  assert( isDeferred==0 || isDeferred==1 ); /* EV: R-30323-21917 */
  pFKey->isDeferred = (u8)isDeferred;
#endif
}

/*
** Cursor iPkCsr is open on a primary key index. This function generates
** code that creates the corresponding covering index record required
** by pIdx by reading values from this cursor. The record is stored in
** register regOut.
*/
void sqlite4EncodeIndexValue(
  Parse *pParse,                  /* Parse context */
  int iPkCsr,                     /* Cursor open on primary key */
  Index *pIdx,                    /* Index to create record for */
  int regOut                      /* Register to write record to */
){
  Vdbe *v = pParse->pVdbe;        /* Generate code into this virtual machine */
  Table *pTab = pIdx->pTable;     /* The table that is indexed */
  int i;                          /* Used to iterate through columns */
  int reg;                        /* Array of pIdx->nCover temp registers */

  reg = sqlite4GetTempRange(pParse, pIdx->nCover);
  for(i=0; i<pIdx->nCover; i++){
    sqlite4ExprCodeGetColumnOfTable(v, pTab, iPkCsr, pIdx->aiCover[i], reg+i);
  }
  sqlite4VdbeAddOp3(v, OP_MakeRecord, reg, pIdx->nCover, regOut);
  sqlite4ReleaseTempRange(pParse, reg, pIdx->nCover);
}

/*
** Generate code that will erase and refill index *pIdx.  This is
** used to initialize a newly created index or to recompute the
** content of an index in response to a REINDEX command.
*/
static void sqlite4RefillIndex(Parse *pParse, Index *pIdx, int bCreate){
  Table *pTab = pIdx->pTable;    /* The table that is indexed */

    sqlite4VdbeAddOp2(v, OP_RowKey, iTab, regKey);
    for(i=0; i<pTab->nCol; i++){
      sqlite4VdbeAddOp3(v, OP_Column, iTab, i, regData+i);
    }
    sqlite4Fts5CodeUpdate(pParse, pIdx, pParse->iNewidxReg, regKey, regData, 0);
  }else{
    int regData = 0;
    regKey = sqlite4GetTempRange(pParse, 2);
    sqlite4GetTempRange(pParse,2);
    regKey = sqlite4GetTempReg(pParse);
    sqlite4EncodeIndexKey(pParse, pPk, iTab, pIdx, iIdx, 0, regKey);
    if( pIdx->onError!=OE_None ){
      const char *zErr = "indexed columns are not unique";
      int addrTest;

      addrTest = sqlite4VdbeAddOp4Int(v, OP_IsUnique, iIdx, 0, regKey, 0);
      sqlite4HaltConstraint(pParse, OE_Abort, (char *)zErr, P4_STATIC);
      sqlite4VdbeJumpHere(v, addrTest);
    }
    if( pIdx->nCover>0 ){
      regData = regKey+1;
      sqlite4EncodeIndexValue(pParse, iTab, pIdx, regData);
    }
    sqlite4VdbeAddOp3(v, OP_Insert, iIdx, regData, regKey);  
    sqlite4VdbeAddOp3(v, OP_IdxInsert, iIdx, 0, regKey);  
    sqlite4ReleaseTempRange(pParse, regKey, 2);
  }

  sqlite4VdbeAddOp2(v, OP_Next, iTab, addr1+1);
  sqlite4VdbeJumpHere(v, addr1);
  sqlite4ReleaseTempReg(pParse, regKey);

  sqlite4VdbeAddOp1(v, OP_Close, iTab);
  sqlite4VdbeAddOp1(v, OP_Close, iIdx);
}

/*
** The CreateIndex structure indicated by the first argument contains the

    sqlite4ErrorMsg(pParse, "virtual tables may not be indexed");
    return 0;
  }

  /* Ensure that the proposed index name is not reserved. */
  assert( pName->z!=0 );
  zName = sqlite4NameFromToken(db, pName);
  if( zName==0 || sqlite4CheckObjectName(pParse, zName) ){
  if( zName==0 || sqlite4CheckObjectName(pParse, zName) ) return 0;
    pTab = 0;
  }

  /* Unless SQLite is currently parsing an existing database schema, check
  ** that there is not already an index or table using the proposed name.  */
  else if( !db->init.busy ){
  if( !db->init.busy ){
    char *zDb = db->aDb[iDb].zName;
    if( sqlite4FindTable(db, zName, zDb)!=0 ){
      sqlite4ErrorMsg(pParse, "there is already a table named %s", zName);
    }
    else if( sqlite4FindIndex(db, zName, zDb)!=0 ){
      if( p->bIfnotexist ){
        assert( !db->init.busy );

    char *zIdx = 0;
    int iDb = 0;

    pTab = createIndexFindTable(pParse, p, &pIdxName, &zIdx, &iDb);
    if( pTab && 0==createIndexAuth(pParse, pTab, zIdx) ){
      int nExtra = sqlite4Fts5IndexSz();
      char *zExtra = 0;
      pIdx = newIndex(pParse, pTab, zIdx, 0, 0, 0, nExtra, &zExtra);
      pIdx = newIndex(pParse, pTab, zIdx, 0, 0, nExtra, &zExtra);
      if( pIdx ){
        pIdx->pFts = (Fts5Index *)zExtra;
        sqlite4Fts5IndexInit(pParse, pIdx, pList);
        pIdx->eIndexType = SQLITE4_INDEX_FTS5;
      }
    }

    sqlite4DbFree(db, zIdx);
  }

  sqlite4ExprListDelete(db, pList);
  sqlite4SrcListDelete(db, p->pTblName);
}

/*
** Parameter zName points to a nul-terminated buffer containing a column
** name. If table pTab has a column of the specified name, return its
** index (the first table column being 0, the next 1 etc.). Or, if there
** is no such column, leave an error in pParse and return -1.
*/
static int findTableColumn(Parse *pParse, Table *pTab, const char *zName){
  int j;
  Column *pTabCol;

  for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
    if( sqlite4_stricmp(zName, pTabCol->zName)==0 ) break;
  }
  if( j>=pTab->nCol ){
    sqlite4ErrorMsg(pParse, "table %s has no column named %s",
        pTab->zName, zName);
    pParse->checkSchema = 1;
    return -1;
  }

  return j;
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed.  pParse->pNewTable is a table that is
** currently being constructed by a CREATE TABLE statement.
**
** pList is a list of columns to be indexed.  pList will be NULL if this
** is a primary key or unique-constraint on the most recent column added
** to the table currently under construction.  
**
** If the index is created successfully, return a pointer to the new Index
** structure. This is used by sqlite4AddPrimaryKey() to mark the index
** as the tables primary key (Index.autoIndex==2).
*/
Index *sqlite4CreateIndex(
  Parse *pParse,     /* All information about this parse */
  CreateIndex *pCI,  /* Name of index to create etc. */
  Token *pName1,     /* First part of index name. May be NULL */
  Token *pName2,     /* Second part of index name. May be NULL */
  SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
  ExprList *pList,   /* A list of columns to be indexed */
  IdList *pCovering, /* Covering list (or NULL) */
  int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  Token *pStart,     /* The CREATE token that begins this statement */
  Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
  int sortOrder,     /* Sort order of primary key when pList==NULL */
  int ifNotExist,    /* Omit error if index already exists */
  int bPrimaryKey    /* True to create the tables primary key */
){
  Index *pRet = 0;     /* Pointer to return */
  Table *pTab = 0;     /* Table to be indexed */
  Index *pIndex = 0;   /* The index to be created */
  char *zName = 0;     /* Name of the index */
  int i, j;
  Token nullId;        /* Fake token for an empty ID list */
  sqlite4 *db = pParse->db;
  int iDb;             /* Index of the database that is being written */
  Token *pName = 0;    /* Unqualified name of the index to create */
  ExprListItem *pListItem; /* For looping over pList */
  int nExtra = 0;
  char *zExtra;

  int nCover = 0;
  Token *pStart = 0;
  SrcList *pTblName = 0;

  if( pCI ){
    pStart = &pCI->tCreate;
    pTblName = pCI->pTblName;
  }
  if( pCovering ){
    nCover = pCovering->nId;
    if( nCover==0 ) nCover = pList->nExpr;
  }

  assert( pStart==0 || pEnd!=0 ); /* pEnd must be non-NULL if pStart is */
  assert( pParse->nErr==0 );      /* Never called with prior errors */
  if( db->mallocFailed || IN_DECLARE_VTAB ){
    goto exit_create_index;
  }
  if( SQLITE4_OK!=sqlite4ReadSchema(pParse) ){
    goto exit_create_index;
  }

  /*
  /* Find the table that is to be indexed.  Return early if not found. */
  if( pCI ){
    pTab = createIndexFindTable(pParse, pCI, &pName, &zName, &iDb);
  ** Find the table that is to be indexed.  Return early if not found.
  */
  if( pTblName!=0 ){
    CreateIndex sCreate;
    sCreate.bUnique = onError;
    sCreate.bIfnotexist = ifNotExist;
    sCreate.tCreate = *pStart;
    sCreate.tName1 = *pName1;
    sCreate.tName2 = *pName2;
    sCreate.pTblName = pTblName;

    pTab = createIndexFindTable(pParse, &sCreate, &pName, &zName, &iDb);
    if( !pTab ) goto exit_create_index;

  }else{

    assert( pName==0 );
    assert( pStart==0 );
    pTab = pParse->pNewTable;
    if( !pTab ) goto exit_create_index;
    iDb = sqlite4SchemaToIndex(db, pTab->pSchema);
  }

  assert( pTab!=0 );
  assert( pParse->nErr==0 );
  assert( IsVirtual(pTab)==0 && IsView(pTab)==0 );

  /* If pCI==0 it means that we are dealing with a PRIMARY KEY or 
  /* If pName==0 it means that we are dealing with a primary key or 
  ** UNIQUE constraint.  We have to invent our own name.  */
  if( pCI==0 ){
  if( pName==0 ){
    if( !bPrimaryKey ){
      int n;
      Index *pLoop;
      for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
      zName = sqlite4MPrintf(db, "sqlite_%s_unique%d", pTab->zName, n);
    }else{
      zName = sqlite4MPrintf(db, "%s", pTab->zName);

      if( ALWAYS(pColl) ){
        nExtra += (1 + sqlite4Strlen30(pColl->zName));
      }
    }
  }

  /* Allocate the new Index structure. */
  pIndex = newIndex(
  pIndex = newIndex(pParse, pTab, zName, pList->nExpr, onError, nExtra,&zExtra);
      pParse, pTab, zName, pList->nExpr, nCover, onError, nExtra, &zExtra
  );
  if( !pIndex ) goto exit_create_index;

  assert( pIndex->eIndexType==SQLITE4_INDEX_USER );
  if( pName==0 ){
    if( bPrimaryKey ){
      pIndex->eIndexType = SQLITE4_INDEX_PRIMARYKEY;
    }else{
      pIndex->eIndexType = SQLITE4_INDEX_UNIQUE;
    }
  }

  /* Scan the names of the columns of the table to be indexed and
  ** load the column indices into the Index structure.  Report an error
  ** if any column is not found.
  **
  ** TODO:  Add a test to make sure that the same column is not named
  ** more than once within the same index.  Only the first instance of
  ** the column will ever be used by the optimizer.
  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    const char *zColName = pListItem->zName;
    Column *pTabCol;
    char *zColl;                   /* Collation sequence name */

    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){
      if( sqlite4_stricmp(zColName, pTabCol->zName)==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqlite4ErrorMsg(pParse, "table %s has no column named %s",
    j = findTableColumn(pParse, pTab, pListItem->zName);
    if( j<0 ) goto exit_create_index;

        pTab->zName, zColName);
      pParse->checkSchema = 1;
      goto exit_create_index;
    }
    pIndex->aiColumn[i] = j;
    if( pListItem->pExpr && pListItem->pExpr->pColl ){
      int nColl;
      zColl = pListItem->pExpr->pColl->zName;
      nColl = sqlite4Strlen30(zColl) + 1;
      assert( nExtra>=nColl );
      memcpy(zExtra, zColl, nColl);

      goto exit_create_index;
    }
    pIndex->azColl[i] = zColl;
    pIndex->aSortOrder[i] = (u8)pListItem->sortOrder;
  }
  sqlite4DefaultRowEst(pIndex);

  /* Scan the names of any covered columns. */
  for(i=0; i<nCover; i++){
    if( pCovering->nId ){
      j = findTableColumn(pParse, pTab, pCovering->a[i].zName);
      if( j<0 ) goto exit_create_index;
      pIndex->aiCover[i] = j;
    }else{
      pIndex->aiCover[i] = i;
    }
  }

  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:
    **
    ** CREATE TABLE t(x PRIMARY KEY, y);

exit_create_index:
  if( pIndex ){
    sqlite4DbFree(db, pIndex->zColAff);
    sqlite4DbFree(db, pIndex);
  }
  sqlite4ExprListDelete(db, pList);
  sqlite4SrcListDelete(db, pTblName);
  sqlite4IdListDelete(db, pCovering);
  sqlite4DbFree(db, zName);
  return pRet;
}

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

    pPk = sqlite4FindPrimaryKey(pIdx->pTable, 0);
  }
  nCol = pIdx->nColumn + (pPk ? pPk->nColumn : 0);

  nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
  pKey = (KeyInfo *)sqlite4DbMallocZero(db, nBytes);
  if( pKey ){
    pKey->db = pParse->db;
    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );

    for(i=0; i<pIdx->nColumn; i++){
      char *zColl = pIdx->azColl[i];
      assert( zColl );
      pKey->aColl[i] = sqlite4LocateCollSeq(pParse, zColl);

  "OMIT_UTF16",
#endif
#ifdef SQLITE4_OMIT_VIEW
  "OMIT_VIEW",
#endif
#ifdef SQLITE4_OMIT_VIRTUALTABLE
  "OMIT_VIRTUALTABLE",
#endif
#ifdef SQLITE4_OMIT_XFER_OPT
  "OMIT_XFER_OPT",
#endif
#ifdef SQLITE4_PERFORMANCE_TRACE
  "PERFORMANCE_TRACE",
#endif
#ifdef SQLITE4_PROXY_DEBUG
  "PROXY_DEBUG",
#endif

    ** regSet. After the scan is complete, the VM will loop through the set 
    ** of keys in the RowSet and delete each row. Rows must be deleted after 
    ** the scan is complete because deleting an item can change the scan 
    ** order.  */
    sqlite4VdbeAddOp2(v, OP_Null, 0, regSet);
    VdbeComment((v, "initialize RowSet"));
    pWInfo = sqlite4WhereBegin(
        pParse, pTabList, pWhere, 0, 0, WHERE_DUPLICATES_OK, 0
        pParse, pTabList, pWhere, 0, 0, WHERE_DUPLICATES_OK
    );
    if( pWInfo==0 ) goto delete_from_cleanup;
    sqlite4VdbeAddOp2(v, OP_RowKey, iCur, regKey);
    sqlite4VdbeAddOp3(v, OP_RowSetAdd, regSet, 0, regKey);
    sqlite4WhereEnd(pWInfo);

    /* Unless this is a view, open cursors for all indexes on the table

**
** This routine is not threadsafe.  It should be called from a single
** thread to initialized the library in a multi-threaded system.  Other
** threads should avoid using the sqlite4_env object until after it has
** completely initialized.
*/
int sqlite4_initialize(sqlite4_env *pEnv){
  MUTEX_LOGIC( sqlite4_mutex *pMaster; )       /* The main static mutex */
  int rc;                                      /* Result code */

  if( pEnv==0 ) pEnv = &sqlite4DefaultEnv;

  /* If SQLite is already completely initialized, then this call
  ** to sqlite4_initialize() should be a no-op.  But the initialization
  ** must be complete.  So isInit must not be set until the very end

    sqlite4_mutex_free(pEnv->pFactoryMutex);
    sqlite4_mutex_free(pEnv->pPrngMutex);
    sqlite4_mutex_free(pEnv->pMemMutex);
    pEnv->pMemMutex = 0;
    while( (pMkr = pEnv->pFactory)!=0 && pMkr->isPerm==0 ){
      KVFactory *pNext = pMkr->pNext;
      sqlite4_free(pEnv, pMkr);
      pEnv->pFactory = pNext;
      pMkr = pNext;
    }
    sqlite4MutexEnd(pEnv);
    sqlite4MallocEnd(pEnv);
    pEnv->isInit = 0;
  }
  return SQLITE4_OK;
}

  p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
  if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
    sqlite4 *db = pParse->db;
    Table *pTab = p->pSrc->a[0].pTab;
    Expr *pRhs = p->pEList->a[0].pExpr;
    int iCol = pRhs->iColumn;
    CollSeq *pReq;
    char colaff;
    char aff;

    /* The collation sequence used by the comparison. If an index is to
    ** be used in place of a temp-table, it must be ordered according
    ** to this collation sequence.  */
    pReq = sqlite4BinaryCompareCollSeq(pParse, pX->pLeft, pRhs);
    if( !pReq ) pReq = db->pDfltColl;

    /* Check that the affinity that will be used to perform the 
    ** comparison is the same as the affinity of the column. If
    ** it is not, it is not possible to use any index.  */
    aff = comparisonAffinity(pX);
    colaff = (iCol<0) ? SQLITE4_AFF_NUMERIC : pTab->aCol[iCol].affinity;
    if( aff!=SQLITE4_AFF_NONE && aff!=pTab->aCol[iCol].affinity ) return 0;
    if( 0==sqlite4IndexAffinityOk(pX, colaff) ) return 0;

    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( (pIdx->aiColumn[0]==iCol)
       && sqlite4FindCollSeq(db, pIdx->azColl[0], 0)==pReq
       && (!bReqUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
      ){
        break;
      }
    }
  }

  return pIdx;
}
#endif /* SQLITE4_OMIT_SUBQUERY */

#ifndef SQLITE4_OMIT_SUBQUERY
/*
** This function is used by the implementation of the IN (...) operator.
** The pX parameter is the expression on the RHS of the IN operator, which
** might be either a list of expressions or a subquery.
**
** The job of this routine is to find or create a b-tree object that can
** be used either to test for membership in the RHS set or to iterate through
** all members of the RHS set, skipping duplicates.
** It's job is to find or create a b-tree structure that may be used
** either to test for membership of the (...) set or to iterate through
** its members, skipping duplicates.
**
** A cursor is opened on the b-tree object that the RHS of the IN operator
** and pX->iTable is set to the index of that cursor.
** The index of the cursor opened on the b-tree (database table, database index 
** or ephermal table) is stored in pX->iTable before this function returns.
**
** The returned value of this function indicates the b-tree type, as follows:
**
**   IN_INDEX_ROWID      - The cursor was opened on the PK index of a
**                         table with an implicit integer primary key.
**   IN_INDEX_INDEX_ASC  - The cursor was opened on an ascending index.
**   IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
**   IN_INDEX_EPH        - The cursor was opened on a specially created and
**                         populated epheremal table.
**   IN_INDEX_ROWID - The cursor was opened on a database table.
**   IN_INDEX_INDEX - The cursor was opened on a database index.
**   IN_INDEX_EPH -   The cursor was opened on a specially created and
**                    populated epheremal table.
**
** An existing b-tree might be used if the RHS expression pX is a simple
** subquery such as:
** An existing b-tree may only be used if the SELECT is of the simple
** form:
**
**     SELECT <column> FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephermeral table instead of an
** existing table.  
**
**
** ITERATING THROUGH SET MEMBERS
** 
**   If the prNotFound parameter is 0, then the b-tree will be used to 
**   iterate through the set members, skipping any duplicates. In this
** If the prNotFound parameter is 0, then the b-tree will be used to iterate
** through the set members, skipping any duplicates. In this case an
**   case the piCov parameter is always non-zero. An index on column 
**   <column> of <table> is used in this case if:
** epheremal table must be used unless the selected <column> is guaranteed
**
**     1. The index guarantees the column is unique (i.e. it is a UNIQUE
**        or PRIMARY KEY Index), and
** to be unique - either because it is an INTEGER PRIMARY KEY or it
**
**     2. The index uses the same collation sequence as the comparison
**        performed by expression pX.
**
**     3. The index is a covering index for <column> (either because it
**        is a PRIMARY KEY or was created with a COVERING clause).
**
**   Restriction (3) could be removed by the calling code in where.c.
**
**   Before returning, *piCov is set to the column number of <column> in
**   the value associated with the selected covering or primary key index.
**
** SET MEMBERSHIP TESTS
** has a UNIQUE constraint or UNIQUE index.
**
** If the prNotFound parameter is not 0, then the b-tree will be used 
** for fast set membership tests. In this case an epheremal table must 
** be used unless <column> is an INTEGER PRIMARY KEY or an index can 
** be found with <column> as its left-most column.
**
** When the b-tree is being used for membership tests, the calling function

**     has_null = <test if data structure contains null>
**     register = 1
**   }
**
** in order to avoid running the <test if data structure contains null>
** test more often than is necessary.
*/
#ifndef SQLITE4_OMIT_SUBQUERY
int sqlite4FindInIndex(Parse *pParse, Expr *pX, int *prNotFound, int *piCov){
int sqlite4FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
  Select *p;                            /* SELECT to the right of IN operator */
  Index *pIdx;
  int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
  int iTab = pParse->nTab++;            /* Cursor of the RHS table */
  int mustBeUnique = (prNotFound==0);   /* True if RHS must be unique */
  Vdbe *v = sqlite4GetVdbe(pParse);     /* Virtual machine being coded */

  assert( pX->op==TK_IN );
  assert( mustBeUnique==(piCov!=0) );

  /* This function is only called from two places. In both cases the vdbe
  ** has already been allocated. So assume sqlite4GetVdbe() is always
  ** successful here.  */
  assert(v);
  assert( prNotFound );

  /* Check to see if an existing table or index can be used to
  ** satisfy the query.  This is preferable to generating a new 
  ** ephemeral table.
  ** satisfy the query. This is preferable to generating a new 
  ** ephemeral table.  */
  */
  p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
  if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
    sqlite4 *db = pParse->db;     /* Database connection */
    Table *pTab;                  /* Table <table>. */
    Expr *pExpr;                  /* Expression <column> */
    int iCol;                     /* Index of column <column> */
    int iDb;                      /* Database idx for pTab */
    Index *pIdx;                  /* Used to iterate through indexes on pTab */
    CollSeq *pReq;                /* Collation sequence for comparison */
    char affinity;                /* Affinity of selected column */
    int affinity_ok;              /* True if the affinity matches */

  pIdx = sqlite4FindExistingInIndex(pParse, pX, 0);
    assert( p );                        /* Because of isCandidateForInOpt(p) */
    assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
    assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
    assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
    pTab = p->pSrc->a[0].pTab;
    pExpr = p->pEList->a[0].pExpr;
    iCol = pExpr->iColumn;
   
  if( pIdx ){
    /* Code an OP_VerifyCookie for <table>. */
    iDb = sqlite4SchemaToIndex(db, pTab->pSchema);
    sqlite4CodeVerifySchema(pParse, iDb);

    int iAddr;
    /* The collation sequence used by the comparison. If an index is to
    ** be used in place of a temp-table, it must be ordered according
    ** to this collation sequence.  */
    pReq = sqlite4BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);

    char *pKey;
    /* Check that the affinity that will be used to perform the 
    ** comparison is the same as the affinity of the column. If
    ** it is not, it is not possible to use any index.  */
    affinity = (iCol<0?SQLITE4_AFF_NUMERIC:pTab->aCol[iCol].affinity);
    affinity_ok = sqlite4IndexAffinityOk(pX, affinity);

    int iDb;                      /* aDb[] Index of database containing pIdx */
    for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
      if( (pIdx->aiColumn[0]==iCol)
       && (iCol<0 || sqlite4FindCollSeq(db, pIdx->azColl[0], 0)==pReq)
       && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
      ){
        int iAddr;

        if( mustBeUnique ){
          if( pIdx->eIndexType!=SQLITE4_INDEX_PRIMARYKEY ){
            int i;
            for(i=0; i<pIdx->nCover; i++){
              if( pIdx->aiCover[i]==iCol ) break;
    iDb = sqlite4SchemaToIndex(pParse->db, pIdx->pSchema);
            }
            if( i==pIdx->nCover ) continue;
            *piCov = i;
          }else{
            *piCov = iCol;
          }
        }

        iAddr = sqlite4CodeOnce(pParse);
        sqlite4OpenIndex(pParse, iTab, iDb, pIdx, OP_OpenRead);
    pKey = (char *)sqlite4IndexKeyinfo(pParse, pIdx);
    iAddr = sqlite4CodeOnce(pParse);
    sqlite4VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
        assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );
        if( iCol<0 ){
          eType = IN_INDEX_ROWID;
        }else{
          eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];
        }

        sqlite4VdbeJumpHere(v, iAddr);
        if( prNotFound && !pTab->aCol[iCol].notNull ){
          *prNotFound = ++pParse->nMem;
          sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    sqlite4VdbeChangeP4(v, -1 , pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));
    sqlite4VdbeJumpHere(v, iAddr);

    *prNotFound = ++pParse->nMem;
    sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
        }
      }
    }
  }

  if( eType==0 ){
    /* Could not found an existing table or index to use as the RHS b-tree.
    ** We will have to generate an ephemeral table to do the job.
    pX->iTable = iTab;
  }else{
    /* Could not find an existing table or index to use as the RHS b-tree.
    ** We will have to generate an ephemeral table to do the job.  */
    */
    u32 savedNQueryLoop = pParse->nQueryLoop;
    double savedNQueryLoop = pParse->nQueryLoop;
    int rMayHaveNull = 0;
    eType = IN_INDEX_EPH;
    if( prNotFound ){
      *prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    *prNotFound = rMayHaveNull = ++pParse->nMem;
    sqlite4VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{
      testcase( pParse->nQueryLoop>0 );
      pParse->nQueryLoop = 0;
    sqlite4CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;
      *piCov = 0;
    }
  }
    sqlite4CodeSubselect(pParse, pX, rMayHaveNull);
    pParse->nQueryLoop = savedNQueryLoop;
  }else{
    pX->iTable = iTab;
  }
  
  return eType;
}
#endif

/*
** Generate code for scalar subqueries used as a subquery expression, EXISTS,
** or IN operators.  Examples:

** For a SELECT or EXISTS operator, return the register that holds the
** result.  For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE4_OMIT_SUBQUERY
int sqlite4CodeSubselect(
  Parse *pParse,          /* Parsing context */
  Expr *pExpr,            /* The IN, SELECT, or EXISTS operator */
  int rMayHaveNull        /* Register that records whether NULLs exist in RHS */
  int rMayHaveNull,       /* Register that records whether NULLs exist in RHS */
  int isRowid             /* If true, LHS of IN operator is a rowid */
){
  int testAddr = -1;                      /* One-time test address */
  int rReg = 0;                           /* Register storing resulting */
  Vdbe *v = sqlite4GetVdbe(pParse);
  if( NEVER(v==0) ) return 0;
  sqlite4ExprCachePush(pParse);

      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite4VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
      addr = sqlite4VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;

      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
        SelectDest dest;
        ExprList *pEList;

        assert( !isRowid );
        sqlite4SelectDestInit(&dest, SRT_Set, pExpr->iTable);
        dest.affinity = (u8)affinity;
        assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
        pExpr->x.pSelect->iLimit = 0;
        if( sqlite4Select(pParse, pExpr->x.pSelect, &dest) ){
          return 0;
        }

        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        int i;
        ExprList *pList = pExpr->x.pList;
        ExprListItem *pItem;
        int r1, r2, r3, r4;
        int r1, r2, r3;

        if( !affinity ){
          affinity = SQLITE4_AFF_NONE;
        }
        keyInfo.aColl[0] = sqlite4ExprCollSeq(pParse, pExpr->pLeft);

        /* Loop through each expression in <exprlist>. */

          */
          if( testAddr>=0 && !sqlite4ExprIsConstant(pE2) ){
            sqlite4VdbeChangeToNoop(v, testAddr);
            testAddr = -1;
          }

          /* Evaluate the expression and insert it into the temp table */
          if( isRowid && sqlite4ExprIsInteger(pE2, &iValToIns) ){
            sqlite4VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns);
          }else{
          r3 = sqlite4ExprCodeTarget(pParse, pE2, r1);
          r4 = sqlite4GetTempReg(pParse);
          sqlite4VdbeAddOp2(v, OP_MakeKey, pExpr->iTable, r4);
          sqlite4VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
          sqlite4ExprCacheAffinityChange(pParse, r3, 1);
          sqlite4VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r4);
          sqlite4ReleaseTempReg(pParse, r4);
            r3 = sqlite4ExprCodeTarget(pParse, pE2, r1);
            if( isRowid ){
              sqlite4VdbeAddOp2(v, OP_MustBeInt, r3,
                                sqlite4VdbeCurrentAddr(v)+2);
              sqlite4VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
            }else{
              int r4 = sqlite4GetTempReg(pParse);
              sqlite4VdbeAddOp2(v, OP_MakeKey, pExpr->iTable, r4);
              sqlite4VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
              sqlite4ExprCacheAffinityChange(pParse, r3, 1);
              sqlite4VdbeAddOp3(v, OP_IdxInsert, pExpr->iTable, r2, r4);
              sqlite4ReleaseTempReg(pParse, r4);
            }
          }
        }
        sqlite4ReleaseTempReg(pParse, r1);
        sqlite4ReleaseTempReg(pParse, r2);
      }
      if( !isRowid ){
      sqlite4VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
        sqlite4VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      }
      break;
    }

    case TK_EXISTS:
    case TK_SELECT:
    default: {
      /* If this has to be a scalar SELECT.  Generate code to put the

  /* Compute the RHS.   After this step, the table with cursor
  ** pExpr->iTable will contains the values that make up the RHS.
  */
  v = pParse->pVdbe;
  assert( v!=0 );       /* OOM detected prior to this routine */
  VdbeNoopComment((v, "begin IN expr"));
  eType = sqlite4FindInIndex(pParse, pExpr, &rRhsHasNull, 0);
  eType = sqlite4FindInIndex(pParse, pExpr, &rRhsHasNull);

  /* Figure out the affinity to use to create a key from the results
  ** of the expression. affinityStr stores a static string suitable for
  ** P4 of OP_MakeRecord.
  */
  affinity = comparisonAffinity(pExpr);

  Table *pTab,    /* The table containing the value */
  int iTabCur,    /* The cursor for this table */
  int iCol,       /* Index of the column to extract */
  int regOut      /* Extract the valud into this register */
){
  if( iCol<0 ){
    sqlite4VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
  }else if( IsKvstore(pTab) ){
    int aOp[2] = { OP_RowKey, OP_RowData };
    assert( iCol==0 || iCol==1 );
    sqlite4VdbeAddOp2(v, aOp[iCol], iTabCur, regOut);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite4VdbeAddOp3(v, op, iTabCur, iCol, regOut);
  }
  if( iCol>=0 ){
    sqlite4ColumnDefault(v, pTab, iCol, regOut);
  }

      break;
    }
#ifndef SQLITE4_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      testcase( op==TK_EXISTS );
      testcase( op==TK_SELECT );
      inReg = sqlite4CodeSubselect(pParse, pExpr, 0);
      inReg = sqlite4CodeSubselect(pParse, pExpr, 0, 0);
      break;
    }
    case TK_IN: {
      int destIfFalse = sqlite4VdbeMakeLabel(v);
      int destIfNull = sqlite4VdbeMakeLabel(v);
      sqlite4VdbeAddOp2(v, OP_Null, 0, target);
      sqlite4ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

  sNameContext.pSrcList = pSrc;
  sNameContext.pParse = pParse;
  sqlite4ResolveExprNames(&sNameContext, pWhere);

  /* Create VDBE to loop through the entries in pSrc that match the WHERE
  ** clause. For each row found, increment the relevant constraint counter
  ** by nIncr.  */
  pWInfo = sqlite4WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
  pWInfo = sqlite4WhereBegin(pParse, pSrc, pWhere, 0, 0, 0);
  if( nIncr>0 && pFKey->isDeferred==0 ){
    sqlite4ParseToplevel(pParse)->mayAbort = 1;
  }
  sqlite4VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
  if( pWInfo ){
    sqlite4WhereEnd(pWInfo);
  }

      /* Check if any parent key columns are being modified. */
      for(p=sqlite4FkReferences(pTab); p; p=p->pNextTo){
        for(i=0; i<p->nCol; i++){
          char *zKey = p->aCol[i].zCol;
          int iKey;
          for(iKey=0; iKey<pTab->nCol; iKey++){
            Column *pCol = &pTab->aCol[iKey];
            if( (zKey ? !sqlite4_stricmp(pCol->zName,zKey) : pCol->iPrimKey>0) ){
            if( (zKey ? !sqlite4_stricmp(pCol->zName, zKey) : pCol->isPrimKey) ){
              if( aChange[iKey]>=0 ) return 1;
            }
          }
        }
      }
    }
  }

        int iOff = 0;
        int nStream = 0;
        int nAlloc;

        /* If pnRow is not NULL, then this is the global record. Read the
        ** number of documents in the table from the start of the record. */
        if( pnRow ){
          iOff += sqlite4GetVarint64(&aData[iOff], nData-iOff, (u64 *)pnRow);
          iOff += sqlite4GetVarint(&aData[iOff], (u64 *)pnRow);
        }
        iOff += getVarint32(&aData[iOff], nStream);
        nAlloc = (nStream < nMinStream ? nMinStream : nStream);

        pSz = sqlite4DbMallocZero(db, 
            sizeof(Fts5Size) + sizeof(i64) * pInfo->nCol * nAlloc
        );
        if( pSz==0 ){
          rc = SQLITE4_NOMEM;
        }else{
          int iCol = 0;
          pSz->aSz = (i64 *)&pSz[1];
          pSz->nCol = pInfo->nCol;
          pSz->nStream = nAlloc;
          while( iOff<nData ){
            int i;
            i64 *aSz = &pSz->aSz[iCol*nAlloc];
            for(i=0; i<nStream; i++){
              iOff += sqlite4GetVarint64(&aData[iOff],nData-iOff,(u64*)&aSz[i]);
              iOff += sqlite4GetVarint(&aData[iOff], (u64*)&aSz[i]);
            }
            iCol++;
          }
        }
      }
    }
    sqlite4KVCursorClose(pCsr);

  i64 nRow, 
  u8 *a                           /* Space to serialize record in */
){
  int iOff = 0;
  int iCol;

  if( nRow>=0 ){
    iOff += sqlite4PutVarint64(&a[iOff], nRow);
    iOff += sqlite4PutVarint(&a[iOff], nRow);
  }
  iOff += sqlite4PutVarint64(&a[iOff], pSz->nStream);
  iOff += sqlite4PutVarint(&a[iOff], pSz->nStream);

  for(iCol=0; iCol<pSz->nCol; iCol++){
    int i;
    for(i=0; i<pSz->nStream; i++){
      iOff += sqlite4PutVarint64(&a[iOff], pSz->aSz[iCol*pSz->nStream+i]);
      iOff += sqlite4PutVarint(&a[iOff], pSz->aSz[iCol*pSz->nStream+i]);
    }
  }

  return sqlite4KVStoreReplace(p, aKey, nKey, a, iOff);
}

static int fts5CsrLoadGlobal(Fts5Cursor *pCsr){

        rc = sqlite4Fts5Pk(pCsr, pInfo->iTbl, &aKey, &nKey);
        if( rc==SQLITE4_OK ){
          rc = sqlite4KVCursorSeek(pCsr->pCsr, aKey, nKey, 0);
          if( rc==SQLITE4_NOTFOUND ){
            rc = SQLITE4_CORRUPT_BKPT;
          }
        }

        if( rc==SQLITE4_OK ){
          rc = sqlite4KVCursorData(pCsr->pCsr, 0, -1, &aData, &nData);
        }

        if( rc==SQLITE4_OK ){
          int i;
          RowDecoder *pCodec;   /* The decoder object */
          ValueDecoder *pCodec;   /* The decoder object */

          rc = sqlite4VdbeDecoderCreate(db,0, pCsr->pCsr, pInfo->nCol, &pCodec);
          rc = sqlite4VdbeCreateDecoder(db, aData, nData, pInfo->nCol, &pCodec);
          for(i=0; rc==SQLITE4_OK && i<pInfo->nCol; i++){
            rc = sqlite4VdbeDecoderGetColumn(pCodec, i, 0, &pCsr->aMem[i]);
            rc = sqlite4VdbeDecodeValue(pCodec, i, 0, &pCsr->aMem[i]);
          }
          sqlite4VdbeDecoderDestroy(pCodec);
          sqlite4VdbeDestroyDecoder(pCodec);
        }

        if( rc==SQLITE4_OK ) pCsr->bMemValid = 1;
      }
    }

    if( rc==SQLITE4_OK ){

** found in:
**
**   Stephen Robertson and Hugo Zaragoza: "The Probablistic Relevance
**   Framework: BM25 and Beyond", 2009.
*/

#include "sqliteInt.h"
#include <math.h>                 // temporary: For log() */
#include <math.h>                 /* temporary: For log() */

static char fts5Tolower(char c){
  if( c>='A' && c<='Z' ) c = c + ('a' - 'A');
  return c;
}

static int fts5SimpleCreate(

  */
  n = sqlite4_value_int(argv[0]);
  sqlite4_result_text(context, sqlite4_compileoption_get(n), -1,
                      SQLITE4_STATIC, 0);
}
#endif /* SQLITE4_OMIT_COMPILEOPTION_DIAGS */

/* Array for converting from half-bytes (nybbles) into ASCII hex
** digits. */
static const char hexdigits[] = {
  '0', '1', '2', '3', '4', '5', '6', '7',
  '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' 
};

/*
** EXPERIMENTAL - This is not an official function.  The interface may
** change.  This function may disappear.  Do not write code that depends
** on this function.
**
** Implementation of the QUOTE() function.  This function takes a single
** argument.  If the argument is numeric, the return value is the same as

    case SQLITE4_FLOAT: {
      sqlite4_result_value(context, argv[0]);
      break;
    }
    case SQLITE4_BLOB: {
      int nBlob;
      char *zText = 0;
      const char *zBlob = sqlite4_value_blob(argv[0], &nBlob);
      char const *zBlob = sqlite4_value_blob(argv[0], &nBlob);
      zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4); 
      if( zText ){
        zText[0] = 'x';
        zText[1] = '\'';
        sqlite4BlobToHex(nBlob, (const u8*)zBlob, zText+2);
        int i;
        for(i=0; i<nBlob; i++){
          zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
          zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
        }
        zText[(nBlob*2)+2] = '\'';
        zText[(nBlob*2)+3] = 0;
        zText[(nBlob*2)+3] = '\0';
        zText[0] = 'x';
        zText[1] = '\'';
        sqlite4_result_text(context, zText, -1, SQLITE4_TRANSIENT, 0);
        sqlite4_free(sqlite4_context_env(context), zText);
      }
      break;
    }
    case SQLITE4_TEXT: {
      int i,j;

static void hexFunc(
  sqlite4_context *context,
  int argc,
  sqlite4_value **argv
){
  int i, n;
  const unsigned char *pBlob;
  char *zHex;
  char *zHex, *z;
  assert( argc==1 );
  UNUSED_PARAMETER(argc);
  pBlob = sqlite4_value_blob(argv[0], &n);
  zHex = contextMalloc(context, ((i64)n)*2 + 1);
  z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
  if( zHex ){
    sqlite4BlobToHex(n, (const u8*)pBlob, zHex);
    for(i=0; i<n; i++, pBlob++){
      unsigned char c = *pBlob;
      *(z++) = hexdigits[(c>>4)&0xf];
      *(z++) = hexdigits[c&0xf];
    }
    *z = 0;
    sqlite4_result_text(context, zHex, n*2, SQLITE4_DYNAMIC, 0);
  }
}

/*
** The replace() function.  Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived

  /* Allocate a VDBE and begin a write transaction */
  v = sqlite4GetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pParse->nested==0 ) sqlite4VdbeCountChanges(v);
  sqlite4BeginWriteOperation(pParse, pSelect || pTrigger, iDb);

#ifndef SQLITE4_OMIT_XFER_OPT
  /* If the statement is of the form
  **
  **       INSERT INTO <table1> SELECT * FROM <table2>;
  **
  ** Then special optimizations can be applied that make the transfer
  ** very fast and which reduce fragmentation of indices.
  **
  ** This is the 2nd template.
  */
  if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
    assert( !pTrigger );
    assert( pList==0 );
    goto insert_end;
  }
#endif /* SQLITE4_OMIT_XFER_OPT */

  /* If this is an AUTOINCREMENT table, look up the sequence number in the
  ** sqlite_sequence table and store it in memory cell regAutoinc.
  */
  regAutoinc = autoIncBegin(pParse, iDb, pTab);

  /* Figure out how many columns of data are supplied.  If the data
  ** is coming from a SELECT statement, then generate a co-routine that

  int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
){
  int i;
  Vdbe *v;
  Index *pIdx;
  u8 pik_flags;
  int regRec;
  int regCover;

  v = sqlite4GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */

  if( pParse->nested ){
    pik_flags = 0;
  }else{
    pik_flags = OPFLAG_NCHANGE | (isUpdate?OPFLAG_ISUPDATE:0);
  }

  /* Generate code to serialize array of registers into a database record. 
  /* Generate code to serialize array of registers into a database record. */
  ** This OP_MakeRecord also serves to apply affinities to the array of
  ** input registers at regContent. For this reason it must be executed 
  ** before any MakeRecord instructions used to create covering index
  ** records.  */
  regRec = sqlite4GetTempReg(pParse);
  sqlite4VdbeAddOp3(v, OP_MakeRecord, regContent, pTab->nCol, regRec);
  sqlite4TableAffinityStr(v, pTab);
  sqlite4ExprCacheAffinityChange(pParse, regContent, pTab->nCol);

  regCover = sqlite4GetTempReg(pParse);

  /* Write the entry to each index. */
  for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    assert( pIdx->eIndexType!=SQLITE4_INDEX_PRIMARYKEY || aRegIdx[i] );
    if( pIdx->eIndexType==SQLITE4_INDEX_FTS5 ){
      int iPK;
      sqlite4FindPrimaryKey(pTab, &iPK);
      sqlite4Fts5CodeUpdate(pParse, pIdx, 0, aRegIdx[iPK], regContent, 0);
    }
    else if( aRegIdx[i] ){
      int regData = 0;
      int flags = 0;
      if( pIdx->eIndexType==SQLITE4_INDEX_PRIMARYKEY ){
        regData = regRec;
        flags = pik_flags;
      }else if( pIdx->nCover>0 ){
        int nByte = sizeof(int)*pIdx->nCover;
        int *aiPermute = (int *)sqlite4DbMallocRaw(pParse->db, nByte);

      }
        if( aiPermute ){
          memcpy(aiPermute, pIdx->aiCover, nByte);
          sqlite4VdbeAddOp4(
              v, OP_Permutation, pIdx->nCover, 0, 0,
              (char*)aiPermute, P4_INTARRAY
          );
        }
        regData = regCover;
        sqlite4VdbeAddOp3(v, OP_MakeRecord, regContent, pIdx->nCover, regData);
      }
      sqlite4VdbeAddOp3(v, OP_Insert, baseCur+i, regData, aRegIdx[i]);
      sqlite4VdbeAddOp3(v, OP_IdxInsert, baseCur+i, regData, aRegIdx[i]);
      sqlite4VdbeChangeP5(v, flags);
    }
  }
}

/*
** Generate code that will open cursors for a table and for all

** The following global variable is incremented whenever the
** transfer optimization is used.  This is used for testing
** purposes only - to make sure the transfer optimization really
** is happening when it is suppose to.
*/
int sqlite4_xferopt_count;
#endif /* SQLITE4_TEST */


#ifndef SQLITE4_OMIT_XFER_OPT
/*
** Check to collation names to see if they are compatible.
*/
static int xferCompatibleCollation(const char *z1, const char *z2){
  if( z1==0 ){
    return z2==0;
  }
  if( z2==0 ){
    return 0;
  }
  return sqlite4_stricmp(z1, z2)==0;
}


/*
** Check to see if index pSrc is compatible as a source of data
** for index pDest in an insert transfer optimization.  The rules
** for a compatible index:
**
**    *   The index is over the same set of columns
**    *   The same DESC and ASC markings occurs on all columns
**    *   The same onError processing (OE_Abort, OE_Ignore, etc)
**    *   The same collating sequence on each column
*/
static int xferCompatibleIndex(Index *pDest, Index *pSrc){
  int i;
  assert( pDest && pSrc );
  assert( pDest->pTable!=pSrc->pTable );
  if( pDest->nColumn!=pSrc->nColumn ){
    return 0;   /* Different number of columns */
  }
  if( pDest->onError!=pSrc->onError ){
    return 0;   /* Different conflict resolution strategies */
  }
  for(i=0; i<pSrc->nColumn; i++){
    if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
      return 0;   /* Different columns indexed */
    }
    if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
      return 0;   /* Different sort orders */
    }
    if( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
      return 0;   /* Different collating sequences */
    }
  }

  /* If no test above fails then the indices must be compatible */
  return 1;
}

/*
** Attempt the transfer optimization on INSERTs of the form
**
**     INSERT INTO tab1 SELECT * FROM tab2;
**
** The xfer optimization transfers raw records from tab2 over to tab1.  
** Columns are not decoded and reassemblied, which greatly improves
** performance.  Raw index records are transferred in the same way.
**
** The xfer optimization is only attempted if tab1 and tab2 are compatible.
** There are lots of rules for determining compatibility - see comments
** embedded in the code for details.
**
** This routine returns TRUE if the optimization is guaranteed to be used.
** Sometimes the xfer optimization will only work if the destination table
** is empty - a factor that can only be determined at run-time.  In that
** case, this routine generates code for the xfer optimization but also
** does a test to see if the destination table is empty and jumps over the
** xfer optimization code if the test fails.  In that case, this routine
** returns FALSE so that the caller will know to go ahead and generate
** an unoptimized transfer.  This routine also returns FALSE if there
** is no chance that the xfer optimization can be applied.
**
** This optimization is particularly useful at making VACUUM run faster.
*/
static int xferOptimization(
  Parse *pParse,        /* Parser context */
  Table *pDest,         /* The table we are inserting into */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  int onError,          /* How to handle constraint errors */
  int iDbDest           /* The database of pDest */
){
  ExprList *pEList;                /* The result set of the SELECT */
  Table *pSrc;                     /* The table in the FROM clause of SELECT */
  Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */
  struct SrcList_item *pItem;      /* An element of pSelect->pSrc */
  int i;                           /* Loop counter */
  int iDbSrc;                      /* The database of pSrc */
  int iSrc, iDest;                 /* Cursors from source and destination */
  int addr1, addr2;                /* Loop addresses */
  int emptyDestTest;               /* Address of test for empty pDest */
  int emptySrcTest;                /* Address of test for empty pSrc */
  Vdbe *v;                         /* The VDBE we are building */
  KeyInfo *pKey;                   /* Key information for an index */
  int regAutoinc;                  /* Memory register used by AUTOINC */
  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
  int regData, regRowid, regKey;   /* Registers holding data and rowid */

  if( pSelect==0 ){
    return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
  }
  if( sqlite4TriggerList(pParse, pDest) ){
    return 0;   /* tab1 must not have triggers */
  }
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  if( pDest->tabFlags & TF_Virtual ){
    return 0;   /* tab1 must not be a virtual table */
  }
#endif
  if( onError==OE_Default ){
    if( pDest->iPKey>=0 ) onError = pDest->keyConf;
    if( onError==OE_Default ) onError = OE_Abort;
  }
  assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
  if( pSelect->pSrc->nSrc!=1 ){
    return 0;   /* FROM clause must have exactly one term */
  }
  if( pSelect->pSrc->a[0].pSelect ){
    return 0;   /* FROM clause cannot contain a subquery */
  }
  if( pSelect->pWhere ){
    return 0;   /* SELECT may not have a WHERE clause */
  }
  if( pSelect->pOrderBy ){
    return 0;   /* SELECT may not have an ORDER BY clause */
  }
  /* Do not need to test for a HAVING clause.  If HAVING is present but
  ** there is no ORDER BY, we will get an error. */
  if( pSelect->pGroupBy ){
    return 0;   /* SELECT may not have a GROUP BY clause */
  }
  if( pSelect->pLimit ){
    return 0;   /* SELECT may not have a LIMIT clause */
  }
  assert( pSelect->pOffset==0 );  /* Must be so if pLimit==0 */
  if( pSelect->pPrior ){
    return 0;   /* SELECT may not be a compound query */
  }
  if( pSelect->selFlags & SF_Distinct ){
    return 0;   /* SELECT may not be DISTINCT */
  }
  pEList = pSelect->pEList;
  assert( pEList!=0 );
  if( pEList->nExpr!=1 ){
    return 0;   /* The result set must have exactly one column */
  }
  assert( pEList->a[0].pExpr );
  if( pEList->a[0].pExpr->op!=TK_ALL ){
    return 0;   /* The result set must be the special operator "*" */
  }

  /* At this point we have established that the statement is of the
  ** correct syntactic form to participate in this optimization.  Now
  ** we have to check the semantics.
  */
  pItem = pSelect->pSrc->a;
  pSrc = sqlite4LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
  if( pSrc==0 ){
    return 0;   /* FROM clause does not contain a real table */
  }
  if( pSrc==pDest ){
    return 0;   /* tab1 and tab2 may not be the same table */
  }
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  if( pSrc->tabFlags & TF_Virtual ){
    return 0;   /* tab2 must not be a virtual table */
  }
#endif
  if( pSrc->pSelect ){
    return 0;   /* tab2 may not be a view */
  }
  if( pDest->nCol!=pSrc->nCol ){
    return 0;   /* Number of columns must be the same in tab1 and tab2 */
  }
  if( pDest->iPKey!=pSrc->iPKey ){
    return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */
  }
  for(i=0; i<pDest->nCol; i++){
    if( pDest->aCol[i].affinity!=pSrc->aCol[i].affinity ){
      return 0;    /* Affinity must be the same on all columns */
    }
    if( !xferCompatibleCollation(pDest->aCol[i].zColl, pSrc->aCol[i].zColl) ){
      return 0;    /* Collating sequence must be the same on all columns */
    }
    if( pDest->aCol[i].notNull && !pSrc->aCol[i].notNull ){
      return 0;    /* tab2 must be NOT NULL if tab1 is */
    }
  }
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    if( pDestIdx->onError!=OE_None ){
      destHasUniqueIdx = 1;
    }
    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    if( pSrcIdx==0 ){
      return 0;    /* pDestIdx has no corresponding index in pSrc */
    }
  }
#ifndef SQLITE4_OMIT_CHECK
  if( pDest->pCheck && sqlite4ExprCompare(pSrc->pCheck, pDest->pCheck) ){
    return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
  }
#endif
#ifndef SQLITE4_OMIT_FOREIGN_KEY
  /* Disallow the transfer optimization if the destination table constains
  ** any foreign key constraints.  This is more restrictive than necessary.
  ** But the main beneficiary of the transfer optimization is the VACUUM 
  ** command, and the VACUUM command disables foreign key constraints.  So
  ** the extra complication to make this rule less restrictive is probably
  ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
  */
  if( (pParse->db->flags & SQLITE4_ForeignKeys)!=0 && pDest->pFKey!=0 ){
    return 0;
  }
#endif

  /* If we get this far, it means that the xfer optimization is at
  ** least a possibility, though it might only work if the destination
  ** table (tab1) is initially empty.
  */
#ifdef SQLITE4_TEST
  sqlite4_xferopt_count++;
#endif
  iDbSrc = sqlite4SchemaToIndex(pParse->db, pSrc->pSchema);
  v = sqlite4GetVdbe(pParse);
  sqlite4CodeVerifySchema(pParse, iDbSrc);
  iSrc = pParse->nTab++;
  iDest = pParse->nTab++;
  regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
  sqlite4OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
  if( (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */
   || destHasUniqueIdx                              /* (2) */
   || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */
  ){
    /* In some circumstances, we are able to run the xfer optimization
    ** only if the destination table is initially empty.  This code makes
    ** that determination.  Conditions under which the destination must
    ** be empty:
    **
    ** (1) There is no INTEGER PRIMARY KEY but there are indices.
    **     (If the destination is not initially empty, the rowid fields
    **     of index entries might need to change.)
    **
    ** (2) The destination has a unique index.  (The xfer optimization 
    **     is unable to test uniqueness.)
    **
    ** (3) onError is something other than OE_Abort and OE_Rollback.
    */
    addr1 = sqlite4VdbeAddOp2(v, OP_Rewind, iDest, 0);
    emptyDestTest = sqlite4VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite4VdbeJumpHere(v, addr1);
  }else{
    emptyDestTest = 0;
  }
  sqlite4OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
  emptySrcTest = sqlite4VdbeAddOp2(v, OP_Rewind, iSrc, 0);
  regKey = sqlite4GetTempReg(pParse);
  regData = sqlite4GetTempReg(pParse);
  regRowid = sqlite4GetTempReg(pParse);
  if( pDest->iPKey>=0 ){
    addr1 = sqlite4VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
    addr2 = sqlite4VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
    sqlite4HaltConstraint(
        pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
    sqlite4VdbeJumpHere(v, addr2);
    autoIncStep(pParse, regAutoinc, regRowid);
  }else if( pDest->pIndex==0 ){
    addr1 = sqlite4VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
  }else{
    addr1 = sqlite4VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
    assert( (pDest->tabFlags & TF_Autoincrement)==0 );
  }
  sqlite4VdbeAddOp2(v, OP_RowData, iSrc, regData);
  sqlite4VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
  sqlite4VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_APPEND);
  sqlite4VdbeChangeP4(v, -1, pDest->zName, 0);
  sqlite4VdbeAddOp2(v, OP_Next, iSrc, addr1);
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    assert( pSrcIdx );
    sqlite4VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite4VdbeAddOp2(v, OP_Close, iDest, 0);
    pKey = sqlite4IndexKeyinfo(pParse, pSrcIdx);
    sqlite4VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pSrcIdx->zName));
    pKey = sqlite4IndexKeyinfo(pParse, pDestIdx);
    sqlite4VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pDestIdx->zName));
    addr1 = sqlite4VdbeAddOp2(v, OP_Rewind, iSrc, 0);
    sqlite4VdbeAddOp2(v, OP_RowKey, iSrc, regKey);
    sqlite4VdbeAddOp2(v, OP_RowData, iSrc, regData);
    sqlite4VdbeAddOp3(v, OP_IdxInsert, iDest, regKey, regData);
    sqlite4VdbeChangeP5(v, OPFLAG_APPENDBIAS);
    sqlite4VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
    sqlite4VdbeJumpHere(v, addr1);
  }
  sqlite4VdbeJumpHere(v, emptySrcTest);
  sqlite4ReleaseTempReg(pParse, regRowid);
  sqlite4ReleaseTempReg(pParse, regData);
  sqlite4ReleaseTempReg(pParse, regKey);
  sqlite4VdbeAddOp2(v, OP_Close, iSrc, 0);
  sqlite4VdbeAddOp2(v, OP_Close, iDest, 0);
  if( emptyDestTest ){
    sqlite4VdbeAddOp2(v, OP_Halt, SQLITE4_OK, 0);
    sqlite4VdbeJumpHere(v, emptyDestTest);
    sqlite4VdbeAddOp2(v, OP_Close, iDest, 0);
    return 0;
  }else{
    return 1;
  }
}
#endif /* SQLITE4_OMIT_XFER_OPT */

  return rc;
}

/*
** Store schema cookie value iVal.
*/
int sqlite4KVStorePutSchema(KVStore *p, unsigned int iVal){
  kvTrace(p, "xPutMeta(%d,%d)", p->kvId, (int)iVal);
  kvTrace(p, "xPutMeta(%d,%d) -> %s", p->kvId, (int)iVal);
  return p->pStoreVfunc->xPutMeta(p, iVal);
}

/*
** Read the schema cookie value into *piVal.
*/
int sqlite4KVStoreGetSchema(KVStore *p, unsigned int *piVal){

void lsmDbDatabaseRelease(lsm_db *);

int lsmBeginReadTrans(lsm_db *);
int lsmBeginWriteTrans(lsm_db *);
int lsmBeginFlush(lsm_db *);

int lsmDetectRoTrans(lsm_db *db, int *);
int lsmBeginRoTrans(lsm_db *db);

int lsmBeginWork(lsm_db *);
void lsmFinishWork(lsm_db *, int, int *);

int lsmFinishRecovery(lsm_db *);
void lsmFinishReadTrans(lsm_db *);
int lsmFinishWriteTrans(lsm_db *, int);

}

/*
** Set the output variable to the number of KB of data written into the
** database file since the most recent checkpoint.
*/
int lsmCheckpointSize(lsm_db *db, int *pnKB){
  ShmHeader *pShm = db->pShmhdr;
  int rc = LSM_OK;
  u32 nSynced;

  /* Set nSynced to the number of pages that had been written when the 
  ** database was last checkpointed. */
  rc = lsmCheckpointSynced(db, 0, 0, &nSynced);

  if( rc==LSM_OK ){
    u32 nPgsz = db->pShmhdr->aSnap1[CKPT_HDR_PGSZ];
    u32 nWrite = db->pShmhdr->aSnap1[CKPT_HDR_NWRITE];
    *pnKB = (int)(( ((i64)(nWrite - nSynced) * nPgsz) + 1023) / 1024);
  }

  return rc;
}

    const int nPagePerBlock = (pFS->nBlocksize / pFS->nPagesize);
    int nSz = pFS->nPagesize;
    u8 *aBuf = 0;
    u8 *aData = 0;

    for(i=0; rc==LSM_OK && i<nPagePerBlock; i++){
      i64 iOff = iFromOff + i*nSz;
      Page *pPg;

      /* Set aData to point to a buffer containing the from page */
      if( (iOff+nSz)<=pFS->nMapLimit ){
        u8 *aMap = (u8 *)(pFS->pMap);
        aData = &aMap[iOff];
      }else{
        if( aBuf==0 ){

void lsmLogClose(lsm_db *db){
  if( db->pLogWriter ){
    lsmFree(db->pEnv, db->pLogWriter->buf.z);
    lsmFree(db->pEnv, db->pLogWriter);
    db->pLogWriter = 0;
  }
}

    }else{
      lsm_rollback(pDb, 0);
    }
  }

  return rc;
}

#ifdef LSM_LOG_WORK
      lsmLogMessage(pDb, 0, "finish checkpoint %d", 
          (int)lsmCheckpointId(pDb->aSnapshot, 0)
      );
#endif
    }

    if( rc==LSM_OK && bTruncate && nBlock>0 ){
    if( rc==LSM_OK && bTruncate ){
      rc = lsmFsTruncateDb(pDb->pFS, (i64)nBlock*lsmFsBlockSize(pDb->pFS));
    }
  }

  lsmShmLock(pDb, LSM_LOCK_CHECKPOINTER, LSM_LOCK_UNLOCK, 0);
  if( pnWrite && rc==LSM_OK ) *pnWrite = nWrite;
  return rc;

      nKB = (((i64)nWrite * lsmFsPageSize(pDb->pFS)) + 1023) / 1024;
    }
    *pnKB = nKB;
  }

  return rc;
}

  int eType = 0;

  switch( iKey ){
    case CURSOR_DATA_TREE0:
    case CURSOR_DATA_TREE1: {
      TreeCursor *pTreeCsr = pCsr->apTreeCsr[iKey-CURSOR_DATA_TREE0];
      if( lsmTreeCursorValid(pTreeCsr) ){
        int nVal;
        void *pVal;

        lsmTreeCursorKey(pTreeCsr, &eType, &pKey, &nKey);
        lsmTreeCursorValue(pTreeCsr, &pVal, &nVal);
      }
      break;
    }

    case CURSOR_DATA_SYSTEM: {
      Snapshot *pWorker = pCsr->pDb->pWorker;
      if( pWorker && (pCsr->flags & CURSOR_FLUSH_FREELIST) ){

    pCsr->nPtr = iPtr;
  }
}

static int multiCursorAddAll(MultiCursor *pCsr, Snapshot *pSnap){
  Level *pLvl;
  int nPtr = 0;
  int iPtr = 0;
  int rc = LSM_OK;

  for(pLvl=pSnap->pLevel; pLvl; pLvl=pLvl->pNext){
    /* If the LEVEL_INCOMPLETE flag is set, then this function is being
    ** called (indirectly) from within a sortedNewToplevel() call to
    ** construct pLvl. In this case ignore pLvl - this cursor is going to
    ** be used to retrieve a freelist entry from the LSM, and the partially

    void *pKey;
    int nKey;
    multiCursorGetKey(pCsr, pCsr->aTree[1], &pCsr->eType, &pKey, &nKey);
    *pRc = sortedBlobSet(pCsr->pDb->pEnv, &pCsr->key, pKey, nKey);
  }
}

#ifdef LSM_DEBUG_EXPENSIVE
#ifndef NDEBUG
static void assertCursorTree(MultiCursor *pCsr){
  int bRev = !!(pCsr->flags & CURSOR_PREV_OK);
  int *aSave = pCsr->aTree;
  int nSave = pCsr->nTree;
  int rc;

  pCsr->aTree = 0;

*/
static int mergeWorkerPushHierarchy(
  MergeWorker *pMW,               /* Merge worker object */
  int iTopic,                     /* Topic value for this key */
  void *pKey,                     /* Pointer to key buffer */
  int nKey                        /* Size of pKey buffer in bytes */
){
  lsm_db *pDb = pMW->pDb;         /* Database handle */
  int rc = LSM_OK;                /* Return Code */
  int iLevel;                     /* Level of b-tree hierachy to write to */
  int nData;                      /* Size of aData[] in bytes */
  u8 *aData;                      /* Page data for level iLevel */
  int iOff;                       /* Offset on b-tree page to write record to */
  int nRec;                       /* Initial number of records on b-tree page */
  Pgno iPtr;                      /* Pointer value to accompany pKey/nKey */

  assert( pMW->aSave[0].bStore==0 );
  assert( pMW->aSave[1].bStore==0 );
  rc = mergeWorkerBtreeIndirect(pMW);

  /* Obtain the absolute pointer value to store along with the key in the

static int mergeWorkerNextPage(
  MergeWorker *pMW,               /* Merge worker object to append page to */
  Pgno iFPtr                      /* Pointer value for footer of new page */
){
  int rc = LSM_OK;                /* Return code */
  Page *pNext = 0;                /* New page appended to run */
  lsm_db *pDb = pMW->pDb;         /* Database handle */
  Segment *pSeg;                  /* Run to append to */

  rc = lsmFsSortedAppend(pDb->pFS, pDb->pWorker, pMW->pLevel, 0, &pNext);
  assert( rc || pMW->pLevel->lhs.iFirst>0 || pMW->pDb->compress.xCompress );

  if( rc==LSM_OK ){
    u8 *aData;                    /* Data buffer belonging to page pNext */
    int nData;                    /* Size of aData[] in bytes */

/*
** Free all resources allocated by mergeWorkerInit().
*/
static void mergeWorkerShutdown(MergeWorker *pMW, int *pRc){
  int i;                          /* Iterator variable */
  int rc = *pRc;
  MultiCursor *pCsr = pMW->pCsr;
  Hierarchy *p = &pMW->hier;

  /* Unless the merge has finished, save the cursor position in the
  ** Merge.aInput[] array. See function mergeWorkerInit() for the 
  ** code to restore a cursor position based on aInput[].  */
  if( rc==LSM_OK && pCsr && lsmMCursorValid(pCsr) ){
    Merge *pMerge = pMW->pLevel->pMerge;
    int bBtree = (pCsr->pBtCsr!=0);

static int mergeWorkerStep(MergeWorker *pMW){
  lsm_db *pDb = pMW->pDb;       /* Database handle */
  MultiCursor *pCsr;            /* Cursor to read input data from */
  int rc = LSM_OK;              /* Return code */
  int eType;                    /* SORTED_SEPARATOR, WRITE or DELETE */
  void *pKey; int nKey;         /* Key */
  Segment *pSeg;                /* Output segment */
  Pgno iPtr;
  int iVal;

  pCsr = pMW->pCsr;
  pSeg = &pMW->pLevel->lhs;

  /* Pull the next record out of the source cursor. */
  lsmMCursorKey(pCsr, &pKey, &nKey);
  eType = pCsr->eType;

  if( eType & LSM_SYSTEMKEY ){
    int i;
    i = 1;
  }

  /* Figure out if the output record may have a different pointer value
  ** than the previous. This is the case if the current key is identical to
  ** a key that appears in the lowest level run being merged. If so, set 
  ** iPtr to the absolute pointer value. If not, leave iPtr set to zero, 
  ** indicating that the output pointer value should be a copy of the pointer 
  ** value written with the previous key.  */

  u32 nHeight;                    /* Height of tree structure */
};

#ifndef NDEBUG
/*
** assert() that a TreeKey.flags value is sane. Usage:
**
**   assert( lsmAssertFlagsOk(pTreeKey->flags) );
**   assert( assertFlagsOk(pTreeKey->flags) );
*/
static int lsmAssertFlagsOk(u8 keyflags){
static int assertFlagsOk(u8 keyflags){
  /* At least one flag must be set. Otherwise, what is this key doing? */
  assert( keyflags!=0 );

  /* The POINT_DELETE and INSERT flags cannot both be set. */
  assert( (keyflags & LSM_POINT_DELETE)==0 || (keyflags & LSM_INSERT)==0 );

  /* If both the START_DELETE and END_DELETE flags are set, then the INSERT
  ** flag must also be set. In other words - the three DELETE flags cannot
  ** all be set */
  assert( (keyflags & LSM_END_DELETE)==0 
       || (keyflags & LSM_START_DELETE)==0 
       || (keyflags & LSM_POINT_DELETE)==0 
  );

  return 1;
}

static int assert_delete_ranges_match(lsm_db *);
static int treeCountEntries(lsm_db *db);
#else
# define lsmAssertFlagsOk(x)
# define assertFlagsOk(x)
#endif

/*
** Container for a key-value pair. Within the *-shm file, each key/value
** pair is stored in a single allocation (which may not actually be 
** contiguous in memory). Layout is the TreeKey structure, followed by
** the nKey bytes of key blob, followed by the nValue bytes of value blob

static void assertIsWorkingChild(
  lsm_db *db, 
  TreeNode *pNode, 
  TreeNode *pParent, 
  int iCell
){
  TreeNode *p;
  int rc = LSM_OK;
  u32 iPtr = getChildPtr(pParent, WORKING_VERSION, iCell);
  p = treeShmptr(db, iPtr);
  assert( p==pNode );
}
#else
# define assertIsWorkingChild(w,x,y,z)
#endif

*/
static TreeKey *csrGetKey(TreeCursor *pCsr, TreeBlob *pBlob, int *pRc){
  TreeKey *pRet;
  lsm_db *pDb = pCsr->pDb;
  u32 iPtr = pCsr->apTreeNode[pCsr->iNode]->aiKeyPtr[pCsr->aiCell[pCsr->iNode]];

  assert( iPtr );
  pRet = (TreeKey*)treeShmptrUnsafe(pDb, iPtr);
  pRet = treeShmptrUnsafe(pDb, iPtr);
  if( !(pRet->flags & LSM_CONTIGUOUS) ){
    pRet = treeShmkey(pDb, iPtr, TKV_LOADVAL, pBlob, pRc);
  }

  return pRet;
}

** If either of the conditions are untrue, LSM_CORRUPT is returned. Or, if
** an error is encountered before the checks are completed, another LSM error
** code (i.e. LSM_IOERR or LSM_NOMEM) may be returned.
*/
static int treeCheckLinkedList(lsm_db *db){
  int rc = LSM_OK;
  int nVisit = 0;
  u32 iShmid;
  ShmChunk *p;

  p = treeShmChunkRc(db, db->treehdr.iFirst, &rc);
  iShmid = p->iShmid;
  while( rc==LSM_OK && p ){
    if( p->iNext ){
      if( p->iNext>=db->treehdr.nChunk ){
        rc = LSM_CORRUPT_BKPT;
      }else{
        ShmChunk *pNext = treeShmChunkRc(db, p->iNext, &rc);
        if( rc==LSM_OK ){

      pCsr->iNode--;
      treeUpdatePtr(db, pCsr, iNew);
    }
  }
}

static int treeNextIsEndDelete(lsm_db *db, TreeCursor *pCsr){
  TreeNode *pNode;
  int iNode = pCsr->iNode;
  int iCell = pCsr->aiCell[iNode]+1;

  /* Cursor currently points to a leaf node. */
  assert( pCsr->iNode==(db->treehdr.root.nHeight-1) );

  while( iNode>=0 ){

    iCell = pCsr->aiCell[iNode];
  }

  return 0;
}

static int treePrevIsStartDelete(lsm_db *db, TreeCursor *pCsr){
  TreeNode *pNode;
  int iNode = pCsr->iNode;

  /* Cursor currently points to a leaf node. */
  assert( pCsr->iNode==(db->treehdr.root.nHeight-1) );

  while( iNode>=0 ){
    TreeNode *pNode = pCsr->apTreeNode[iNode];

      pNode = (TreeNode *)treeShmptrUnsafe(pDb, iNodePtr);
      iNode++;
      pCsr->apTreeNode[iNode] = pNode;

      /* Compare (pKey/nKey) with the key in the middle slot of B-tree node
      ** pNode. The middle slot is never empty. If the comparison is a match,
      ** then the search is finished. Break out of the loop. */
      pTreeKey = (TreeKey*)treeShmptrUnsafe(pDb, pNode->aiKeyPtr[1]);
      pTreeKey = treeShmptrUnsafe(pDb, pNode->aiKeyPtr[1]);
      if( !(pTreeKey->flags & LSM_CONTIGUOUS) ){
        pTreeKey = treeShmkey(pDb, pNode->aiKeyPtr[1], TKV_LOADKEY, &b, &rc);
        if( rc!=LSM_OK ) break;
      }
      res = treeKeycmp((void *)&pTreeKey[1], pTreeKey->nKey, pKey, nKey);
      if( res==0 ){
        pCsr->aiCell[iNode] = 1;
        break;
      }

      /* Based on the results of the previous comparison, compare (pKey/nKey)
      ** to either the left or right key of the B-tree node, if such a key
      ** exists. */
      iTest = (res>0 ? 0 : 2);
      iTreeKey = pNode->aiKeyPtr[iTest];
      if( iTreeKey ){
        pTreeKey = (TreeKey*)treeShmptrUnsafe(pDb, iTreeKey);
        pTreeKey = treeShmptrUnsafe(pDb, iTreeKey);
        if( !(pTreeKey->flags & LSM_CONTIGUOUS) ){
          pTreeKey = treeShmkey(pDb, iTreeKey, TKV_LOADKEY, &b, &rc);
          if( rc ) break;
        }
        res = treeKeycmp((void *)&pTreeKey[1], pTreeKey->nKey, pKey, nKey);
        if( res==0 ){
          pCsr->aiCell[iNode] = iTest;

*/
void sqlite4_profile(
  sqlite4 *db,
  void *pArg,
  void (*xProfile)(void*,const char*,sqlite4_uint64),
  void (*xDestroy)(void*)
){
  void *pOld;
  sqlite4_mutex_enter(db->mutex);
  if( db->xProfileDestroy ){
    db->xProfileDestroy(db->pProfileArg);
  }
  db->xProfile = xProfile;
  db->xProfileDestroy = xDestroy;
  db->pProfileArg = pArg;
  sqlite4_mutex_leave(db->mutex);
}
#endif /* SQLITE4_OMIT_TRACE */

/*
** This function returns true if main-memory should be used instead of
** a temporary file for transient pager files and statement journals.
** The value returned depends on the value of db->temp_store (runtime
** parameter) and the compile time value of SQLITE4_TEMP_STORE. The
** following table describes the relationship between these two values
** and this functions return value.
**
**   SQLITE4_TEMP_STORE     db->temp_store     Location of temporary database
**   -----------------     --------------     ------------------------------
**   0                     any                file      (return 0)
**   1                     1                  file      (return 0)
**   1                     2                  memory    (return 1)
**   1                     0                  file      (return 0)
**   2                     1                  file      (return 0)
**   2                     2                  memory    (return 1)
**   2                     0                  memory    (return 1)
**   3                     any                memory    (return 1)
*/
int sqlite4TempInMemory(const sqlite4 *db){
#if SQLITE4_TEMP_STORE==1
  return ( db->temp_store==2 );
#endif
#if SQLITE4_TEMP_STORE==2
  return ( db->temp_store!=1 );
#endif
#if SQLITE4_TEMP_STORE==3
  return 1;
#endif
#if SQLITE4_TEMP_STORE<1 || SQLITE4_TEMP_STORE>3
  return 0;
#endif
}

/*
** Return UTF-8 encoded English language explanation of the most recent
** error.
*/
const char *sqlite4_errmsg(sqlite4 *db){
  const char *z;

}

/*
** Multiply two numbers and return the result.
*/
sqlite4_num sqlite4_num_mul(sqlite4_num A, sqlite4_num B){
  sqlite4_num r;

  if( A.e>SQLITE4_MX_EXP || B.e>SQLITE4_MX_EXP ){
    r.sign = A.sign ^ B.sign;
  if( A.e>SQLITE4_MX_EXP ){
    A.sign ^= B.sign;
    r.m = (A.m && B.m) ? 1 : 0;
    r.e = SQLITE4_MX_EXP+1;
    r.approx = 0;
    return r;
    return A;
  }else if( B.e>SQLITE4_MX_EXP ){
    B.sign ^= A.sign;
    return B;
  }
  if( A.m==0 ) return A;
  if( B.m==0 ) return B;
  while( A.m%10==0 ){ A.m /= 10; A.e++; }
  while( B.m%10==0 ){ B.m /= 10; B.e++; }
  r.sign = A.sign ^ B.sign;
  r.approx = A.approx | B.approx;

      return r;
    }
    return B;
  }
  if( B.m==0 ){
    r.sign = A.sign ^ B.sign;
    r.e = SQLITE4_NAN_EXP;
    r.m = 0;
    r.m = 1;
    r.approx = 1;
    return r;
  }
  if( A.m==0 ){
    return A;
  }
  while( A.m<TENTH_MAX ){

      nIn -= 1;
    }
  }
  
  /* If the IGNORE_WHITESPACE flag is set, ignore any leading whitespace. */
  i = 0;
  if( flags & SQLITE4_IGNORE_WHITESPACE ){
    while( i<nIn && sqlite4Isspace(zIn[i]) ) i+=incr;
    while( sqlite4Isspace(zIn[i]) && i<nIn ) i+=incr;
  }
  if( nIn<=i ) return error_value;

  /* Check for a leading '+' or '-' symbol. */
  if( zIn[i]=='-' ){
    r.sign = 1;
    i += incr;

      memcpy(z, "NaN", 4);
    }else{
      memcpy(z, "inf", 4);
    }
    return (z - zOut)+3;
  }
  if( x.m==0 ){
    if( bReal ){
      memcpy(z, "0.0", 4);
    }else{
      memcpy(z, "0", 2);
    memcpy(z, "0", 2);
    }
    return 1+(z-zOut);
  }
  zNum = renderInt(x.m, zBuf, sizeof(zBuf));
  n = &zBuf[sizeof(zBuf)-1] - zNum;
  if( x.e>=0 && x.e+n<=25 ){
    /* Integer values with up to 25 digits */
    memcpy(z, zNum, n+1);

  *z++ = 'e';
  if( x.e<0 ){
    *z++ = '-';
    x.e = -x.e;
  }else{
    *z++ = '+';
  }
  z++;
  zNum = renderInt(x.e&0x7fff, zBuf, sizeof(zBuf));
  while( (z[0] = zNum[0])!=0 ){ z++; zNum++; }
  return (z-zOut);
}

  return sqlite4_buffer_append(pBuf, p, n);
}

void sqlite4_buffer_clear(sqlite4_buffer *pBuf){
  sqlite4_mm_free(pBuf->pMM, pBuf->p);
  sqlite4_buffer_init(pBuf, pBuf->pMM);
}

static int debugMutexEnd(void *p){ UNUSED_PARAMETER(p); return SQLITE4_OK; }

/*
** The sqlite4_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it.  If it returns NULL
** that means that a mutex could not be allocated. 
*/
static sqlite4_mutex *debugMutexAlloc(void *pX, int id){
static sqlite4_mutex *debugMutexAlloc(sqlite4_env *pEnv, int id){
  sqlite4_env *pEnv = (sqlite4_env*)pX;
  sqlite4DebugMutex *pNew = 0;
  pNew = sqlite4Malloc(pEnv, sizeof(*pNew));
  if( pNew ){
    pNew->id = id;
    pNew->cnt = 0;
    pNew->pEnv = pEnv;
  }

** One or more VALUES claues
*/
struct ValueList {
  ExprList *pList;
  Select *pSelect;
};

/*
** A COVERING clause.
*/
struct CoveringOpt { IdList *pList; Token sEnd; };

} // end %include

// Input is a single SQL command
input ::= cmdlist.
cmdlist ::= cmdlist ecmd.
cmdlist ::= ecmd.
ecmd ::= SEMI.

// In addition to the type name, we also care about the primary key and
// UNIQUE constraints.
//
ccons ::= NULL onconf.
ccons ::= NOT NULL onconf(R).  {sqlite4AddNotNull(pParse, R);}
ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                               {sqlite4AddPrimaryKey(pParse,0,R,I,Z);}
ccons ::= UNIQUE onconf(R).    {sqlite4CreateIndex(pParse,0,0,0,R,0,0,0);}
ccons ::= UNIQUE onconf(R).    {sqlite4CreateIndex(pParse,0,0,0,0,R,0,0,0,0,0);}
ccons ::= CHECK LP expr(X) RP. {sqlite4AddCheckConstraint(pParse,X.pExpr);}
ccons ::= REFERENCES nm(T) idxlist_opt(TA) refargs(R).
                               {sqlite4CreateForeignKey(pParse,0,&T,TA,R);}
ccons ::= defer_subclause(D).  {sqlite4DeferForeignKey(pParse,D);}
ccons ::= COLLATE ids(C).      {sqlite4AddCollateType(pParse, &C);}

// The optional AUTOINCREMENT keyword

conslist ::= conslist COMMA tcons.
conslist ::= conslist tcons.
conslist ::= tcons.
tcons ::= CONSTRAINT nm.
tcons ::= PRIMARY KEY LP idxlist(X) autoinc(I) RP onconf(R).
                             {sqlite4AddPrimaryKey(pParse,X,R,I,0);}
tcons ::= UNIQUE LP idxlist(X) RP onconf(R).
                             {sqlite4CreateIndex(pParse,0,X,0,R,0,0,0);}
                             {sqlite4CreateIndex(pParse,0,0,0,X,R,0,0,0,0,0);}
tcons ::= CHECK LP expr(E) RP onconf.
                             {sqlite4AddCheckConstraint(pParse,E.pExpr);}
tcons ::= FOREIGN KEY LP idxlist(FA) RP
          REFERENCES nm(T) idxlist_opt(TA) refargs(R) defer_subclause_opt(D). {
    sqlite4CreateForeignKey(pParse, FA, &T, TA, R);
    sqlite4DeferForeignKey(pParse, D);
}

  C.bIfnotexist = NE;
  C.tCreate = S;
  C.tName1 = X;
  C.tName2 = D;
  C.pTblName = sqlite4SrcListAppend(pParse->db, 0, &Y, 0);
}

cmd ::= createindex(C) LP idxlist(Z) RP(E) covering_opt(F). {
cmd ::= createindex(C) LP idxlist(Z) RP(E). {
  Token *pEnd = (F.pList ? &F.sEnd : &E);
  sqlite4CreateIndex(pParse, &C, Z, F.pList, C.bUnique, pEnd, SQLITE4_SO_ASC,0);
  sqlite4CreateIndex(pParse, &C.tName1, &C.tName2, C.pTblName, Z, 
                C.bUnique, &C.tCreate, &E, SQLITE4_SO_ASC, C.bIfnotexist, 0);
}

%type uniqueflag {int}
uniqueflag(A) ::= UNIQUE.  {A = OE_Abort;}
uniqueflag(A) ::= .        {A = OE_None;}

%type idxlist {ExprList*}

  A = sqlite4ExprListAppend(pParse, 0, sqlite4PExpr(pParse, @Y, 0, 0, &Y));
  sqlite4ExprListSetName(pParse, A, &X, 1);
}
uidxlist(A) ::= ids(Y). {
  A = sqlite4ExprListAppend(pParse, 0, sqlite4PExpr(pParse, @Y, 0, 0, &Y));
}

%type covering_opt { struct CoveringOpt }
%destructor covering_opt {sqlite4IdListDelete(pParse->db, $$.pList);}
covering_opt(A) ::= . { A.pList = 0; }
covering_opt(A) ::= COVERING ALL(X). { 
  A.pList = sqlite4DbMallocZero(pParse->db, sizeof(IdList)); 
  A.sEnd = X;
}
covering_opt(A) ::= COVERING LP inscollist(X) RP(Y). { 
  A.pList = X; 
  A.sEnd = Y;
}


///////////////////////////// The DROP INDEX command /////////////////////////
//
cmd ::= DROP INDEX ifexists(E) fullname(X).   {sqlite4DropIndex(pParse, X, E);}

///////////////////////////// The PRAGMA command /////////////////////////////
//

    }else{
      goto pragma_out;
    }
  }

  pParse->nMem = 2;
  sqlite4VdbeRunOnlyOnce(v);
  if( pList && pList->nExpr>1 ) goto pragma_out;
  zRight = 0;
  if( pList ){
    zRight = pList->a[0].zSpan;
    if( zRight==0 ){ 
      assert( pList->a[0].pExpr->op==TK_ID );
      zRight = pList->a[0].pExpr->u.zToken; 
    }

           pCol->zType ? pCol->zType : "", 0);
        sqlite4VdbeAddOp2(v, OP_Integer, (pCol->notNull ? 1 : 0), 4);
        if( pCol->zDflt ){
          sqlite4VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pCol->zDflt, 0);
        }else{
          sqlite4VdbeAddOp2(v, OP_Null, 0, 5);
        }
        sqlite4VdbeAddOp2(v, OP_Integer, pCol->iPrimKey, 6);
        sqlite4VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
        sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 6);
      }
    }
  }else

  if( sqlite4_stricmp(zPragma, "index_info")==0 && zRight ){
    Index *pIdx;

      }
    }
  }else

  if( sqlite4_stricmp(zPragma, "database_list")==0 ){
    int i;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    sqlite4VdbeSetNumCols(v, 2);
    sqlite4VdbeSetNumCols(v, 3);
    pParse->nMem = 3;
    sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE4_STATIC);
    sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE4_STATIC);
    sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE4_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pKV==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite4VdbeAddOp2(v, OP_Integer, i, 1);
      sqlite4VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
      sqlite4VdbeAddOp4(v, OP_String8, 0, 3, 0,
                           "filename", 0);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 2);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 3);
    }
  }else

  if( sqlite4_stricmp(zPragma, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite4VdbeSetNumCols(v, 2);

  **   PRAGMA kvdump
  **
  ** Print an ascii rendering of the complete content of the database file.
  */
  if( sqlite4_stricmp(zPragma, "kvdump")==0 ){
    sqlite4KVStoreDump(db->aDb[0].pKV);
  }else

  /*
  **   PRAGMA kvreplace(BLOB,BLOB)
  **
  ** Insert or replace a single raw record into the KV store.  This pragma
  ** is exceedingly dangerous and should not be used by general-purpose
  ** applications.  It is intended for internal testing only - to provide
  ** a convenient way to insert arbitrary content into the key/value store.
  */
  if( sqlite4_stricmp(zPragma, "kvreplace")==0
   && pList->nExpr==2
  ){
    int r1, r2;
    Vdbe *v = sqlite4GetVdbe(pParse);
    pParse->nTab = 1;
    pParse->nMem = 3;
    sqlite4BeginWriteOperation(pParse, 0, iDb);
    r1 = sqlite4ExprCodeTarget(pParse, pList->a[0].pExpr, 1);
    sqlite4VdbeAddOp4(v, OP_HaltIfNull, SQLITE4_CONSTRAINT, OE_Abort,
                         r1, "key may not be null", P4_STATIC);
    sqlite4VdbeAddOp1(v, OP_ToBlob, r1);
    r2 = sqlite4ExprCodeTarget(pParse, pList->a[1].pExpr, 2);
    sqlite4VdbeAddOp4(v, OP_HaltIfNull, SQLITE4_CONSTRAINT, OE_Abort,
                         r2, "value may not be null", P4_STATIC);
    sqlite4VdbeAddOp1(v, OP_ToBlob, r2);
    sqlite4VdbeAddOp0(v, OP_OpenWrite);
    sqlite4VdbeAddOp3(v, OP_Insert, 0, r2, r1);
    sqlite4VdbeAddOp0(v, OP_Halt);
  }else
#endif /* SQLITE4_DEBUG
#endif /* SQLITE4_OMIT_COMPILEOPTION_DIAGS */

  /*
  **   PRAGMA integrity_check
  **
  ** Check that for each table, the content of any auxilliary indexes are 
  ** consistent with the primary key index.
  */
  if( sqlite4_stricmp(zPragma, "integrity_check")==0 ){

        Table *pTab = (Table *)sqliteHashData(x);
        int addrRewind;
        int nIdx = 0;
        int iPkCsr;
        Index *pPk;
        int iCsr;

        /* Do nothing for views or sqlite_kvstore */
        if( IsView(pTab) || IsKvstore(pTab) ) continue;
        /* Do nothing for views */
        if( IsView(pTab) ) continue;

        /* Open all indexes for table pTab. */
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          if( pIdx->eIndexType==SQLITE4_INDEX_PRIMARYKEY ){
            pPk = pIdx;
            iPkCsr = nIdx+baseCsr;
          }

  ** This pragma attempts to free as much memory as possible from the
  ** current database connection.
  */
  if( sqlite4_stricmp(zPragma, "shrink_memory")==0 ){
    sqlite4_db_release_memory(db);
  }else

  /*
  **  PRAGMA schema_version
  */
  if( sqlite4_stricmp(zPragma, "schema_version")==0 ){
    if( zRight ){
      /* Write the specified cookie value */
      static const VdbeOpList setCookie[] = {
        { OP_Transaction,    0,  1,  0},    /* 0 */
        { OP_Integer,        0,  1,  0},    /* 1 */
        { OP_SetCookie,      0,  0,  1},    /* 2 */
      };
      int addr = sqlite4VdbeAddOpList(v, ArraySize(setCookie), setCookie);
      sqlite4VdbeChangeP1(v, addr, iDb);
      sqlite4VdbeChangeP1(v, addr+1, sqlite4Atoi(zRight));
      sqlite4VdbeChangeP1(v, addr+2, iDb);
    }else{
      /* Read the specified cookie value */
      static const VdbeOpList readCookie[] = {
        { OP_Transaction,     0,  0,  0},    /* 0 */
        { OP_ReadCookie,      0,  1,  0},    /* 1 */
        { OP_ResultRow,       1,  1,  0}
      };
      int addr = sqlite4VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite4VdbeChangeP1(v, addr, iDb);
      sqlite4VdbeChangeP1(v, addr+1, iDb);
      sqlite4VdbeSetNumCols(v, 1);
      sqlite4VdbeSetColName(v, 0, COLNAME_NAME, zPragma, SQLITE4_TRANSIENT);
    }
  }else

 
  {/* Empty ELSE clause */}



 pragma_out:
  sqlite4DbFree(db, zPragma);
  /* sqlite4DbFree(db, zRight); */
  sqlite4ExprListDelete(db, pList);
}

#if 0
/*
** Process a pragma statement.  
**
** Pragmas are of this form:
**
**      PRAGMA [database.]id [= value]
**
** The identifier might also be a string.  The value is a string, and
** identifier, or a number.  If minusFlag is true, then the value is
** a number that was preceded by a minus sign.
**
** If the left side is "database.id" then pId1 is the database name
** and pId2 is the id.  If the left side is just "id" then pId1 is the
** id and pId2 is any empty string.
*/
void sqlite4Pragma(
  Parse *pParse, 
  Token *pId1,        /* First part of [database.]id field */
  Token *pId2,        /* Second part of [database.]id field, or NULL */
  ExprList *pList     /* List of pragma arguments */
){
  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 */
  int iDb;               /* Database index for <database> */
  sqlite4 *db = pParse->db;
  Db *pDb;
  Vdbe *v = pParse->pVdbe = sqlite4VdbeCreate(db);
  if( v==0 ) return;
  sqlite4VdbeRunOnlyOnce(v);
  pParse->nMem = 2;

  /* Interpret the [database.] part of the pragma statement. iDb is the
  ** index of the database this pragma is being applied to in db.aDb[]. */
  iDb = sqlite4TwoPartName(pParse, pId1, pId2, &pId);
  if( iDb<0 ) return;
  pDb = &db->aDb[iDb];

  /* If the temp database has been explicitly named as part of the 
  ** pragma, make sure it is open. 
  */
  if( iDb==1 && sqlite4OpenTempDatabase(pParse) ){
    return;
  }

  zLeft = sqlite4NameFromToken(db, pId);
  if( !zLeft ) return;
  if( minusFlag ){
    zRight = sqlite4MPrintf(db, "-%T", pValue);
  }else{
    zRight = sqlite4NameFromToken(db, pValue);
  }

  assert( pId2 );
  zDb = pId2->n>0 ? pDb->zName : 0;
  if( sqlite4AuthCheck(pParse, SQLITE4_PRAGMA, zLeft, zRight, zDb) ){
    goto pragma_out;
  }
 


#ifndef SQLITE4_OMIT_FLAG_PRAGMAS
  if( flagPragma(pParse, zLeft, zRight) ){
    /* The flagPragma() subroutine also generates any necessary code
    ** there is nothing more to do here */
  }else
#endif /* SQLITE4_OMIT_FLAG_PRAGMAS */

  /*
  **   PRAGMA fts_check(<index>)
  */
  if( sqlite4_stricmp(zLeft, "fts_check")==0 && zRight ){
    int iCksum1;
    int iCksum2;
    Index *pIdx;
    Table *pTab;
    Vdbe *v = sqlite4GetVdbe(pParse);
    if( v==0 || sqlite4ReadSchema(pParse) ) goto pragma_out;

    iCksum1 = ++pParse->nMem;
    iCksum2 = ++pParse->nMem;
    sqlite4VdbeAddOp2(v, OP_Integer, 0, iCksum1);
    sqlite4VdbeAddOp2(v, OP_Integer, 0, iCksum2);

    pIdx = sqlite4FindIndex(db, zRight, zDb);
    if( pIdx && pIdx->eIndexType==SQLITE4_INDEX_FTS5 ){
      int iTab = pParse->nTab++;
      int iAddr;
      int iReg;
      int i;

      pTab = pIdx->pTable;
      sqlite4OpenPrimaryKey(pParse, iTab, iDb, pTab, OP_OpenRead);
      iAddr = sqlite4VdbeAddOp2(v, OP_Rewind, iTab, 0);

      iReg = pParse->nMem+1;
      pParse->nMem += (1 + pTab->nCol);

      sqlite4VdbeAddOp2(v, OP_RowKey, iTab, iReg);
      for(i=0; i<pTab->nCol; i++){
        sqlite4VdbeAddOp3(v, OP_Column, iTab, i, iReg+1+i);
      }
      sqlite4Fts5CodeCksum(pParse, pIdx, iCksum1, iReg, 0);

      sqlite4VdbeAddOp2(v, OP_Next, iTab, iAddr+1);
      sqlite4VdbeJumpHere(v, iAddr);
      sqlite4VdbeAddOp1(v, OP_Close, iTab);

      sqlite4VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);
      iAddr = sqlite4VdbeAddOp2(v, OP_Rewind, iTab, 0);

      iReg = pParse->nMem+1;
      pParse->nMem += 2;
      sqlite4VdbeAddOp2(v, OP_RowKey, iTab, iReg);
      sqlite4VdbeAddOp2(v, OP_RowData, iTab, iReg+1);
      sqlite4Fts5CodeCksum(pParse, pIdx, iCksum2, iReg, 1);

      sqlite4VdbeAddOp2(v, OP_Next, iTab, iAddr+1);
      sqlite4VdbeJumpHere(v, iAddr);
      sqlite4VdbeAddOp1(v, OP_Close, iTab);

      iReg = ++pParse->nMem;
      sqlite4VdbeAddOp4(v, OP_String8, 0, iReg, 0, "ok", 0);
      iAddr = sqlite4VdbeAddOp3(v, OP_Eq, iCksum1, 0, iCksum2);
      sqlite4VdbeAddOp4(v, OP_String8, 0, iReg, 0, "error - cksum mismatch", 0);
      sqlite4VdbeJumpHere(v, iAddr);
      sqlite4VdbeAddOp2(v, OP_ResultRow, iReg, 1);

      sqlite4VdbeSetNumCols(v, 1);
    }
  }



#ifndef SQLITE4_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.
  */
  if( sqlite4_stricmp(zLeft, "table_info")==0 && zRight ){
    Table *pTab;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite4FindTable(db, zRight, zDb);
    if( pTab ){
      int i;
      int nHidden = 0;
      Column *pCol;
      sqlite4VdbeSetNumCols(v, 6);
      pParse->nMem = 6;
      sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "cid", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "type", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 3, COLNAME_NAME, "notnull", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 5, COLNAME_NAME, "pk", SQLITE4_STATIC);
      sqlite4ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        if( IsHiddenColumn(pCol) ){
          nHidden++;
          continue;
        }
        sqlite4VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
        sqlite4VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
        sqlite4VdbeAddOp4(v, OP_String8, 0, 3, 0,
           pCol->zType ? pCol->zType : "", 0);
        sqlite4VdbeAddOp2(v, OP_Integer, (pCol->notNull ? 1 : 0), 4);
        if( pCol->zDflt ){
          sqlite4VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pCol->zDflt, 0);
        }else{
          sqlite4VdbeAddOp2(v, OP_Null, 0, 5);
        }
        sqlite4VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
        sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 6);
      }
    }
  }else

  if( sqlite4_stricmp(zLeft, "index_info")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    pIdx = sqlite4FindIndex(db, zRight, zDb);
    if( pIdx ){
      int i;
      pTab = pIdx->pTable;
      sqlite4VdbeSetNumCols(v, 3);
      pParse->nMem = 3;
      sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE4_STATIC);
      sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE4_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite4VdbeAddOp2(v, OP_Integer, i, 1);
        sqlite4VdbeAddOp2(v, OP_Integer, cnum, 2);
        assert( pTab->nCol>cnum );
        sqlite4VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
        sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 3);
      }
    }
  }else

  if( sqlite4_stricmp(zLeft, "index_list")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite4FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite4GetVdbe(pParse);
      pIdx = pTab->pIndex;
      if( pIdx ){
        int i = 0; 
        sqlite4VdbeSetNumCols(v, 3);
        pParse->nMem = 3;
        sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE4_STATIC);
        while(pIdx){
          sqlite4VdbeAddOp2(v, OP_Integer, i, 1);
          sqlite4VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
          sqlite4VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
          sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 3);
          ++i;
          pIdx = pIdx->pNext;
        }
      }
    }
  }else

  if( sqlite4_stricmp(zLeft, "database_list")==0 ){
    int i;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    sqlite4VdbeSetNumCols(v, 3);
    pParse->nMem = 3;
    sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE4_STATIC);
    sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE4_STATIC);
    sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE4_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pKV==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite4VdbeAddOp2(v, OP_Integer, i, 1);
      sqlite4VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
      sqlite4VdbeAddOp4(v, OP_String8, 0, 3, 0,
                           "filename", 0);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 3);
    }
  }else

  if( sqlite4_stricmp(zLeft, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite4VdbeSetNumCols(v, 2);
    pParse->nMem = 2;
    sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE4_STATIC);
    sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE4_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite4VdbeAddOp2(v, OP_Integer, i++, 1);
      sqlite4VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 2);
    }
  }else
#endif /* SQLITE4_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE4_OMIT_FOREIGN_KEY
  if( sqlite4_stricmp(zLeft, "foreign_key_list")==0 && zRight ){
    FKey *pFK;
    Table *pTab;
    if( sqlite4ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite4FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite4GetVdbe(pParse);
      pFK = pTab->pFKey;
      if( pFK ){
        int i = 0; 
        sqlite4VdbeSetNumCols(v, 8);
        pParse->nMem = 8;
        sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "id", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 1, COLNAME_NAME, "seq", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 2, COLNAME_NAME, "table", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 3, COLNAME_NAME, "from", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 4, COLNAME_NAME, "to", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 5, COLNAME_NAME, "on_update", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 6, COLNAME_NAME, "on_delete", SQLITE4_STATIC);
        sqlite4VdbeSetColName(v, 7, COLNAME_NAME, "match", SQLITE4_STATIC);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            char *zCol = pFK->aCol[j].zCol;
            char *zOnDelete = (char *)actionName(pFK->aAction[0]);
            char *zOnUpdate = (char *)actionName(pFK->aAction[1]);
            sqlite4VdbeAddOp2(v, OP_Integer, i, 1);
            sqlite4VdbeAddOp2(v, OP_Integer, j, 2);
            sqlite4VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
            sqlite4VdbeAddOp4(v, OP_String8, 0, 4, 0,
                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
            sqlite4VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
            sqlite4VdbeAddOp4(v, OP_String8, 0, 6, 0, zOnUpdate, 0);
            sqlite4VdbeAddOp4(v, OP_String8, 0, 7, 0, zOnDelete, 0);
            sqlite4VdbeAddOp4(v, OP_String8, 0, 8, 0, "NONE", 0);
            sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 8);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else
#endif /* !defined(SQLITE4_OMIT_FOREIGN_KEY) */

#ifndef NDEBUG
  if( sqlite4_stricmp(zLeft, "parser_trace")==0 ){
    if( zRight ){
      if( sqlite4GetBoolean(zRight) ){
        sqlite4ParserTrace(stderr, "parser: ");
      }else{
        sqlite4ParserTrace(0, 0);
      }
    }
  }else
#endif

  /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
  ** used will be case sensitive or not depending on the RHS.
  */
  if( sqlite4_stricmp(zLeft, "case_sensitive_like")==0 ){
    if( zRight ){
      sqlite4RegisterLikeFunctions(db, sqlite4GetBoolean(zRight));
    }
  }else

#ifndef SQLITE4_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE4_INTEGRITY_CHECK_ERROR_MAX 100
#endif


#ifndef SQLITE4_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
  **
  ** In its first form, this pragma returns the encoding of the main
  ** database. If the database is not initialized, it is initialized now.
  **
  ** The second form of this pragma is a no-op if the main database file
  ** has not already been initialized. In this case it sets the default
  ** encoding that will be used for the main database file if a new file
  ** is created. If an existing main database file is opened, then the
  ** default text encoding for the existing database is used.
  ** 
  ** In all cases new databases created using the ATTACH command are
  ** created to use the same default text encoding as the main database. If
  ** 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
  */
  if( sqlite4_stricmp(zLeft, "encoding")==0 ){
    static const struct EncName {
      char *zName;
      u8 enc;
    } encnames[] = {
      { "UTF8",     SQLITE4_UTF8        },
      { "UTF-8",    SQLITE4_UTF8        },  /* Must be element [1] */
      { "UTF-16le", SQLITE4_UTF16LE     },  /* Must be element [2] */
      { "UTF-16be", SQLITE4_UTF16BE     },  /* Must be element [3] */
      { "UTF16le",  SQLITE4_UTF16LE     },
      { "UTF16be",  SQLITE4_UTF16BE     },
      { "UTF-16",   0                  }, /* SQLITE4_UTF16NATIVE */
      { "UTF16",    0                  }, /* SQLITE4_UTF16NATIVE */
      { 0, 0 }
    };
    const struct EncName *pEnc;
    if( !zRight ){    /* "PRAGMA encoding" */
      if( sqlite4ReadSchema(pParse) ) goto pragma_out;
      sqlite4VdbeSetNumCols(v, 1);
      sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "encoding", SQLITE4_STATIC);
      sqlite4VdbeAddOp2(v, OP_String8, 0, 1);
      assert( encnames[SQLITE4_UTF8].enc==SQLITE4_UTF8 );
      assert( encnames[SQLITE4_UTF16LE].enc==SQLITE4_UTF16LE );
      assert( encnames[SQLITE4_UTF16BE].enc==SQLITE4_UTF16BE );
      sqlite4VdbeChangeP4(v, -1, encnames[ENC(pParse->db)].zName, P4_STATIC);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }else{                        /* "PRAGMA encoding = XXX" */
      /* Only change the value of sqlite.enc if the database handle is not
      ** initialized. If the main database exists, the new sqlite.enc value
      ** will be overwritten when the schema is next loaded. If it does not
      ** already exists, it will be created to use the new encoding value.
      */
      if( 
        !(DbHasProperty(db, 0, DB_SchemaLoaded)) || 
        DbHasProperty(db, 0, DB_Empty) 
      ){
        for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
          if( 0==sqlite4_stricmp(zRight, pEnc->zName) ){
            ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE4_UTF16NATIVE;
            break;
          }
        }
        if( !pEnc->zName ){
          sqlite4ErrorMsg(pParse, "unsupported encoding: %s", zRight);
        }
      }
    }
  }else
#endif /* SQLITE4_OMIT_UTF16 */


#ifndef SQLITE4_OMIT_COMPILEOPTION_DIAGS
  /*
  **   PRAGMA compile_options
  **
  ** Return the names of all compile-time options used in this build,
  ** one option per row.
  */
  if( sqlite4_stricmp(zLeft, "compile_options")==0 ){
    int i = 0;
    const char *zOpt;
    sqlite4VdbeSetNumCols(v, 1);
    pParse->nMem = 1;
    sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE4_STATIC);
    while( (zOpt = sqlite4_compileoption_get(i++))!=0 ){
      sqlite4VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
      sqlite4VdbeAddOp2(v, OP_ResultRow, 1, 1);
    }
  }else
#endif /* SQLITE4_OMIT_COMPILEOPTION_DIAGS */

#ifdef SQLITE4_DEBUG
  /*
  **   PRAGMA kvdump
  **
  ** Print an ascii rendering of the complete content of the database file.
  */
  if( sqlite4_stricmp(zLeft, "kvdump")==0 ){
    sqlite4KVStoreDump(db->aDb[0].pKV);
  }else
#endif /* SQLITE4_OMIT_COMPILEOPTION_DIAGS */
  /*
  **   PRAGMA integrity_check
  **
  ** Check that for each table, the content of any auxilliary indexes are 
  ** consistent with the primary key index.
  */
  if( sqlite4_stricmp(zLeft, "integrity_check")==0 ){
    const int baseCsr = 1;        /* Base cursor for OpenAllIndexes() call */

    const int regErrcnt = 1;      /* Register containing error count */
    const int regErrstr = 2;      /* Register containing error string */
    const int regTmp = 3;         /* Register for tmp use */
    const int regRowcnt1 = 4;     /* Register containing row count (from PK) */
    const int regRowcnt2 = 5;     /* Register containing error count */
    const int regResult = 6;      /* Register containing result string */
    const int regKey = 7;         /* Register containing encoded key */
    const int regArray = 8;       /* First in array of registers */

    int i;
    int nMaxArray = 1;
    int addrNot = 0;
    Vdbe *v;

    if( sqlite4ReadSchema(pParse) ) goto pragma_out;

    for(i=0; i<db->nDb; i++){
      if( OMIT_TEMPDB && i==1 ) continue;
      sqlite4CodeVerifySchema(pParse, i);
    }

    v = sqlite4GetVdbe(pParse);
    sqlite4VdbeAddOp2(v, OP_Integer, 0, regErrcnt);
    sqlite4VdbeAddOp4(v, OP_String8, 0, regErrstr, 0, "", 0);

    for(i=0; i<db->nDb; i++){
      Hash *pTbls;
      HashElem *x;

      if( OMIT_TEMPDB && i==1 ) continue;

      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Index *pIdx;
        Table *pTab = (Table *)sqliteHashData(x);
        int addrRewind;
        int nIdx = 0;
        int iPkCsr;
        Index *pPk;
        int iCsr;

        /* Do nothing for views */
        if( IsView(pTab) ) continue;

        /* Open all indexes for table pTab. */
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          if( pIdx->eIndexType==SQLITE4_INDEX_PRIMARYKEY ){
            pPk = pIdx;
            iPkCsr = nIdx+baseCsr;
          }
          nIdx++;
        }
        sqlite4OpenAllIndexes(pParse, pTab, baseCsr, OP_OpenRead);

        sqlite4VdbeAddOp2(v, OP_Integer, 0, regRowcnt1);
        addrRewind = sqlite4VdbeAddOp1(v, OP_Rewind, iPkCsr);

        /* Increment the row-count register */
        sqlite4VdbeAddOp2(v, OP_AddImm, regRowcnt1, 1);

        for(iCsr=baseCsr, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCsr++){
          assert( (pIdx->eIndexType==SQLITE4_INDEX_PRIMARYKEY)==(iCsr==iPkCsr) );
          if( iCsr!=iPkCsr ){
            char *zErr;
            int iCol;
            int jmp;
            for(iCol=0; iCol<pIdx->nColumn; iCol++){
              int r = regArray + iCol;
              sqlite4VdbeAddOp3(v, OP_Column, iPkCsr, pIdx->aiColumn[iCol], r);
              assert( pIdx->aiColumn[iCol]>=0 );
            }
            for(iCol=0; iCol<pPk->nColumn; iCol++){
              int reg = regArray + pIdx->nColumn + iCol;
              int iTblCol = pPk->aiColumn[iCol];
              if( iTblCol<0 ){
                sqlite4VdbeAddOp2(v, OP_Rowid, iPkCsr, reg);
              }else{
                sqlite4VdbeAddOp3(v, OP_Column, iPkCsr, iTblCol, reg);
              }
            }

            if( (pPk->nColumn+pIdx->nColumn)>nMaxArray ){
              nMaxArray = pPk->nColumn + pIdx->nColumn;
            }

            sqlite4VdbeAddOp3(v, OP_MakeIdxKey, iCsr, regArray, regKey);
            jmp = sqlite4VdbeAddOp4(v, OP_Found, iCsr, 0, regKey, 0, P4_INT32);
            sqlite4VdbeAddOp2(v, OP_AddImm, regErrcnt, 1);
            zErr = sqlite4MPrintf(
                db, "entry missing from index %s: ", pIdx->zName
            );
            sqlite4VdbeAddOp4(v, OP_String8, 0, regTmp, 0, zErr, 0);
            sqlite4VdbeAddOp3(v, OP_Concat, regTmp, regErrstr, regErrstr);
            sqlite4VdbeAddOp3(v, OP_Function, 0, regKey, regTmp);
            sqlite4VdbeChangeP4(v, -1,
                (char *)sqlite4FindFunction(db, "hex", 3, 1, 0), 
                P4_FUNCDEF
            );
            sqlite4VdbeChangeP5(v, 1);
            sqlite4VdbeAddOp3(v, OP_Concat, regTmp, regErrstr, regErrstr);
            sqlite4VdbeAddOp4(v, OP_String8, 0, regTmp, 0, "\n", 0);
            sqlite4VdbeAddOp3(v, OP_Concat, regTmp, regErrstr, regErrstr);
            sqlite4VdbeJumpHere(v, jmp);
            sqlite4DbFree(db, zErr);
          }
        }
        sqlite4VdbeAddOp2(v, OP_Next, iPkCsr, addrRewind+1);
        sqlite4VdbeJumpHere(v, addrRewind);

        for(iCsr=baseCsr, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCsr++){
          if( iCsr!=iPkCsr ){
            char *zErr;
            int addrEq;
            int addrRewind2;
            sqlite4VdbeAddOp2(v, OP_Integer, 0, regRowcnt2);
            addrRewind2 = sqlite4VdbeAddOp1(v, OP_Rewind, iCsr);
            sqlite4VdbeAddOp2(v, OP_AddImm, regRowcnt2, 1);
            sqlite4VdbeAddOp2(v, OP_Next, iCsr, addrRewind2+1);
            sqlite4VdbeJumpHere(v, addrRewind2);
            zErr = sqlite4MPrintf(
                db, "wrong # number of entries in index %s\n", pIdx->zName
            );
            addrEq = sqlite4VdbeAddOp3(v, OP_Eq, regRowcnt1, 0, regRowcnt2);
            sqlite4VdbeAddOp2(v, OP_AddImm, regErrcnt, 1);
            sqlite4VdbeAddOp4(v, OP_String8, 0, regTmp, 0, zErr, 0);
            sqlite4VdbeAddOp3(v, OP_Concat, regTmp, regErrstr, regErrstr);

            sqlite4VdbeJumpHere(v, addrEq);
            sqlite4DbFree(db, zErr);
          }
        }

        for(iCsr=baseCsr; iCsr<(baseCsr+nIdx); iCsr++){
          sqlite4VdbeAddOp1(v, OP_Close, iCsr);
        }
      }
    }

    sqlite4VdbeAddOp4(v, OP_String8, 0, regResult, 0, "ok", 0);
    addrNot = sqlite4VdbeAddOp1(v, OP_IfNot, regErrcnt);
    sqlite4VdbeAddOp4(v, OP_String8, 0, regArray, 0, " errors:\n", 0);
    sqlite4VdbeAddOp3(v, OP_Concat, regArray, regErrcnt, regResult);
    sqlite4VdbeAddOp3(v, OP_Concat, regErrstr, regResult, regResult);
    sqlite4VdbeJumpHere(v, addrNot);

    pParse->nMem = (regArray + nMaxArray);
    sqlite4VdbeSetNumCols(v, 1);
    sqlite4VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", SQLITE4_STATIC);
    sqlite4VdbeAddOp2(v, OP_ResultRow, regResult, 1);

  }else


  /*
  **  PRAGMA shrink_memory
  **
  ** This pragma attempts to free as much memory as possible from the
  ** current database connection.
  */
  if( sqlite4_stricmp(zLeft, "shrink_memory")==0 ){
    sqlite4_db_release_memory(db);
  }else

 
  {/* Empty ELSE clause */}
pragma_out:
  sqlite4DbFree(db, zLeft);
  sqlite4DbFree(db, zRight);
}
#endif

#endif /* SQLITE4_OMIT_PRAGMA */

          sqlite4_value_text(apVal[2], 0)     /* Text of CREATE statement */
      );
    }
  }

  return 0;
}

static int createSchemaTable(
  InitData *pInit,
  const char *zName,
  i64 iRoot,
  const char *zSchema
){
  Table *pTab;
  initCallback(pInit, zName, iRoot, zSchema);
  if( pInit->rc ) return 1;
  pTab = sqlite4FindTable(pInit->db, zName, pInit->db->aDb[pInit->iDb].zName);
  if( ALWAYS(pTab) ) pTab->tabFlags |= TF_Readonly;
  return 0;
}


/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file.  The index of the
** database file is given by iDb.  iDb==0 is used for the main
** database.  iDb==1 should never be used.  iDb>=2 is used for
** auxiliary databases.  Return one of the SQLITE4_ error codes to
** indicate success or failure.
*/
static int sqlite4InitOne(sqlite4 *db, int iDb, char **pzErrMsg){
  int rc;
  Table *pTab;
  Db *pDb;
  InitData initData;
  char const *zMasterSchema;
  char const *zMasterName;
  char const *zKvstoreName;
  int openedTransaction = 0;

  /*
  ** The master database table has a structure like this
  */
  static const char *aMaster[] = {
  static const char master_schema[] = 
     "CREATE TABLE sqlite_master(\n"
     "  type text,\n"
     "  name text,\n"
     "  tbl_name text,\n"
     "  rootpage integer,\n"
     "  sql text\n"
     ")", 
     ")"
  ;
#ifndef SQLITE4_OMIT_TEMPDB
  static const char temp_master_schema[] = 
     "CREATE TEMP TABLE sqlite_temp_master(\n"
     "  type text,\n"
     "  name text,\n"
     "  tbl_name text,\n"
     "  rootpage integer,\n"
     "  sql text\n"
     ")"
  ;
#endif
#else
  };
  static const char *aKvstore[] = {
     "CREATE TABLE sqlite_kvstore(key BLOB PRIMARY KEY, value BLOB)",
#ifndef SQLITE4_OMIT_TEMPDB
     "CREATE TABLE sqlite_temp_kvstore(key BLOB PRIMARY KEY, value BLOB)"
#endif
  };
  static const char *aKvstoreName[] = {
     "sqlite_kvstore",
#ifndef SQLITE4_OMIT_TEMPDB
     "sqlite_temp_kvstore"
  #define temp_master_schema 0
#endif
  };


  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pSchema );
  assert( sqlite4_mutex_held(db->mutex) );

  /* zMasterSchema and zInitScript are set to point at the master schema
  ** and initialisation script appropriate for the database being
  /* zMasterName is the name of the master table.  */
  ** initialised. zMasterName is the name of the master table.
  */
  if( !OMIT_TEMPDB && iDb==1 ){
    zMasterSchema = temp_master_schema;
  }else{
    zMasterSchema = master_schema;
  }
  zMasterName = SCHEMA_TABLE(iDb);
  zKvstoreName = aKvstoreName[iDb==1];

  /* Construct the schema tables.  */
  initData.db = db;
  initData.iDb = iDb;
  initData.rc = SQLITE4_OK;
  initData.pzErrMsg = pzErrMsg;
  if( createSchemaTable(&initData, zMasterName, 1, aMaster[iDb==1])
  initCallback(&initData, zMasterName, 1, zMasterSchema);
   || createSchemaTable(&initData, zKvstoreName, KVSTORE_ROOT, aKvstore[iDb==1])
  ){
  if( initData.rc ){
    rc = initData.rc;
    goto error_out;
  }
  pTab = sqlite4FindTable(db, zMasterName, db->aDb[iDb].zName);
  if( ALWAYS(pTab) ){
    pTab->tabFlags |= TF_Readonly;
  }

  /* Create a cursor to hold the database open
  */
  pDb = &db->aDb[iDb];
  if( pDb->pKV==0 ){
    if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){

#define FLAG_STRING  4     /* Allow infinity precision */


/*
** The following table is searched linearly, so it is good to put the
** most frequently used conversion types first.
*/
static const char aDigits[] = "0123456789abcdef0123456789ABCDEF";
static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";
static const char aPrefix[] = "-x0\000X0";
static const et_info fmtinfo[] = {
  {  'd', 10, 1, etRADIX,      0,  0 },
  {  's',  0, 4, etSTRING,     0,  0 },
  {  'g',  0, 1, etGENERIC,    14, 0 },
  {  'g',  0, 1, etGENERIC,    30, 0 },
  {  'z',  0, 4, etDYNSTRING,  0,  0 },
  {  'q',  0, 4, etSQLESCAPE,  0,  0 },
  {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
  {  'w',  0, 4, etSQLESCAPE3, 0,  0 },
  {  'c',  0, 0, etCHARX,      0,  0 },
  {  'o',  8, 0, etRADIX,      0,  2 },
  {  'u', 10, 0, etRADIX,      0,  0 },
  {  'x', 16, 0, etRADIX,      0,  1 },
  {  'X', 16, 0, etRADIX,      16, 4 },
  {  'x', 16, 0, etRADIX,      16, 1 },
  {  'X', 16, 0, etRADIX,      0,  4 },
#ifndef SQLITE4_OMIT_FLOATING_POINT
  {  'f',  0, 1, etFLOAT,      0,  0 },
  {  'e',  0, 1, etEXP,        14, 0 },
  {  'E',  0, 1, etEXP,        30, 0 },
  {  'G',  0, 1, etGENERIC,    30, 0 },
  {  'e',  0, 1, etEXP,        30, 0 },
  {  'E',  0, 1, etEXP,        14, 0 },
  {  'G',  0, 1, etGENERIC,    14, 0 },
#endif
  {  'i', 10, 1, etRADIX,      0,  0 },
  {  'n',  0, 0, etSIZE,       0,  0 },
  {  '%',  0, 0, etPERCENT,    0,  0 },
  {  'p', 16, 0, etPOINTER,    0,  1 },

/* All the rest have the FLAG_INTERN bit set and are thus for internal

void sqlite4XPrintf(StrAccum *p, const char *zFormat, ...){
  va_list ap;
  va_start(ap,zFormat);
  sqlite4VXPrintf(p, 1, zFormat, ap);
  va_end(ap);
}
#endif

/*
** Convert an N-byte blob into hex.  The caller is responsible for making
** sure zOut contains at least N*2+1 bytes of usable space.
*/
void sqlite4BlobToHex(int N, const u8 *zIn, char *zOut){
  while( (N--)>0 ){
    u8 c = *(zIn++);
    *(zOut++) = aDigits[c>>4];
    *(zOut++) = aDigits[c&0x0f];
  }
  *zOut = 0;
}

  /* If a column from a table in pSrcList is referenced, then record
  ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
  ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the
  ** column number is greater than the number of bits in the bitmask
  ** then set the high-order bit of the bitmask.
  */
  if( pMatch!=0 ){
  if( pExpr->iColumn>=0 && pMatch!=0 ){
    int n = pExpr->iColumn;
    testcase( n==BMS-1 );
    if( n>=BMS || n<0 ){
    if( n>=BMS ){
      n = BMS-1;
    }
    assert( pMatch->iCursor==pExpr->iTable );
    pMatch->colUsed |= ((Bitmask)1)<<n;
  }

  /* Clean up and return

  if( p ){
    SrcListItem *pItem = &pSrc->a[iSrc];
    p->pTab = pItem->pTab;
    p->iTable = pItem->iCursor;
    p->iColumn = (ynVar)iCol;
    testcase( iCol==BMS );
    testcase( iCol==BMS-1 );
    pItem->colUsed |= ((Bitmask)1)<<((iCol>=BMS || iCol<0) ? BMS-1 : iCol);
    pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
    ExprSetProperty(p, EP_Resolved);
  }
  return p;
}

static void resolveMatchArg(Parse *pParse, NameContext *pNC, Expr *pExpr){
  SrcList *pSrc = pNC->pSrcList;

  Select *pSelect,                /* The whole SELECT statement */
  int regData                     /* Register holding data to be sorted */
){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite4GetTempRange(pParse, nExpr+1);
  int regKey = sqlite4GetTempReg(pParse);
  int op;

  /* Assemble the sort-key values in a contiguous array of registers
  ** starting at regBase. The sort-key consists of the result of each 
  ** expression in the ORDER BY clause followed by a unique sequence 
  ** number. The sequence number allows more than one row with the same
  ** sort-key.  */
  sqlite4ExprCacheClear(pParse);
  sqlite4ExprCodeExprList(pParse, pOrderBy, regBase, 0);
  sqlite4VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);

  /* Encode the sort-key. */
  sqlite4VdbeAddOp3(v, OP_MakeIdxKey, pOrderBy->iECursor, regBase, regKey);

  /* Insert an entry into the sorter. The key inserted is the encoded key
  ** created by the OP_MakeIdxKey coded above. The value is the record
  ** currently stored in register regData.  */
  if( pSelect->selFlags & SF_UseSorter ){
    op = OP_SorterInsert;
  }else{
    op = OP_IdxInsert;
  }
  sqlite4VdbeAddOp3(v, OP_Insert, pOrderBy->iECursor, regData, regKey);
  sqlite4VdbeAddOp3(v, op, pOrderBy->iECursor, regData, regKey);

  /* Release the temporary registers */
  sqlite4ReleaseTempReg(pParse, regKey);
  sqlite4ReleaseTempRange(pParse, regBase, nExpr+1);

  if( pSelect->iLimit ){
    int addr1, addr2;

  v = pParse->pVdbe;
  r1 = sqlite4GetTempReg(pParse);
  r2 = sqlite4GetTempReg(pParse);
  sqlite4VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N);
  sqlite4VdbeAddOp2(v, OP_MakeKey, iTab, r2);
  sqlite4VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
  sqlite4VdbeAddOp3(v, OP_Insert, iTab, r1, r2);
  sqlite4VdbeAddOp3(v, OP_IdxInsert, iTab, r1, r2);
  sqlite4ReleaseTempReg(pParse, r1);
  sqlite4ReleaseTempReg(pParse, r2);
}

#ifndef SQLITE4_OMIT_SUBQUERY
/*
** Generate an error message when a SELECT is used within a subexpression

#ifndef SQLITE4_OMIT_COMPOUND_SELECT
    case SRT_Union: {
      int r1, r2;
      r1 = sqlite4GetTempReg(pParse);
      r2 = sqlite4GetTempReg(pParse);
      sqlite4VdbeAddOp2(v, OP_MakeKey, iParm, r2);
      sqlite4VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
      sqlite4VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
      sqlite4VdbeAddOp3(v, OP_IdxInsert, iParm, r1, r2);
      sqlite4ReleaseTempReg(pParse, r1);
      sqlite4ReleaseTempReg(pParse, r2);
      break;
    }

    /* This is used for processing queries of the form:
    **

        sqlite4VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1);
        pushOntoSorter(pParse, pOrderBy, p, r1);
      }else{
        int r2 = sqlite4GetTempReg(pParse);
        sqlite4VdbeAddOp2(v, OP_MakeKey, iParm, r2);
        sqlite4VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1);
        sqlite4ExprCacheAffinityChange(pParse, regResult, 1);
        sqlite4VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
        sqlite4VdbeAddOp3(v, OP_IdxInsert, iParm, r1, r2);
        sqlite4ReleaseTempReg(pParse, r2);
      }
      sqlite4ReleaseTempReg(pParse, r1);
      break;
    }

    /* If any row exist in the result set, record that fact and abort.

  pInfo = (KeyInfo *)sqlite4DbMallocZero(db, nByte);

  if( pInfo ){
    int i;                        /* Used to iterate through pList */

    pInfo->aSortOrder = (u8*)&pInfo->aColl[nField];
    pInfo->nField = (u16)nField;
    pInfo->enc = ENC(db);
    pInfo->db = db;

    for(i=0; i<pList->nExpr; i++){
      CollSeq *pColl;
      pColl = sqlite4ExprCollSeq(pParse, pList->a[i].pExpr);
      if( !pColl ) pColl = db->pDfltColl;
      pInfo->aColl[i] = pColl;
      pInfo->aSortOrder[i] = pList->a[i].sortOrder;

  SelectDest *pDest               /* Write the sorted results here */
){
  int addrBreak = sqlite4VdbeMakeLabel(v);     /* Jump here to exit loop */
  int addrContinue = sqlite4VdbeMakeLabel(v);  /* Jump here for next cycle */
  int addr;
  int iTab;                       /* Sorter object cursor */
  ExprList *pOrderBy = p->pOrderBy;

  int eDest = pDest->eDest;
  int iParm = pDest->iParm;
  int op;                         /* Opcode use to sort results */

  int regRow;
  int regRowid = 0;

  iTab = pOrderBy->iECursor;
  regRow = sqlite4GetTempReg(pParse);
  if( eDest!=SRT_Output && eDest!=SRT_Coroutine ){
    regRowid = sqlite4GetTempReg(pParse);
  }

  op = (p->selFlags & SF_UseSorter) ? OP_SorterSort : OP_Sort;
  addr = 1 + sqlite4VdbeAddOp2(v, op, iTab, addrBreak);
  codeOffset(v, p, addrContinue);
  if( p->selFlags & SF_UseSorter ){
    int regSortOut = ++pParse->nMem;
    int ptab2 = pParse->nTab++;
    sqlite4VdbeAddOp3(v, OP_OpenPseudo, ptab2, regSortOut, pOrderBy->nExpr+2);
    addr = 1 + sqlite4VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
    codeOffset(v, p, addrContinue);
    sqlite4VdbeAddOp2(v, OP_SorterData, iTab, regSortOut);
    sqlite4VdbeAddOp3(v, OP_Column, ptab2, 0, regRow);
    sqlite4VdbeChangeP5(v, OPFLAG_CLEARCACHE);
  }else{
    addr = 1 + sqlite4VdbeAddOp2(v, OP_Sort, iTab, addrBreak);
    codeOffset(v, p, addrContinue);
    sqlite4VdbeAddOp3(v, OP_Column, iTab, 0, regRow);
  }
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      int regRowid = sqlite4GetTempReg(pParse);
      int regRow = sqlite4GetTempReg(pParse);
      testcase( eDest==SRT_Table );
      testcase( eDest==SRT_EphemTab );
      sqlite4VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
      sqlite4VdbeAddOp2(v, OP_RowData, iTab, regRow);
      sqlite4VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
      sqlite4VdbeChangeP5(v, OPFLAG_APPEND);
      sqlite4ReleaseTempReg(pParse, regRow);
      sqlite4ReleaseTempReg(pParse, regRowid);
      break;
    }
#ifndef SQLITE4_OMIT_SUBQUERY
    case SRT_Set: {
      int regRes = sqlite4GetTempReg(pParse);
      int regKey = sqlite4GetTempReg(pParse);
      int regValue = sqlite4GetTempReg(pParse);
      assert( nColumn==1 );
      sqlite4VdbeAddOp3(v, OP_Column, iTab, 0, regRes);
      int regKey = sqlite4GetTempReg(pParse);
      sqlite4VdbeAddOp2(v, OP_MakeKey, iParm, regKey);
      sqlite4VdbeAddOp4(v, OP_MakeRecord, regRes, 1, regValue, &p->affinity, 1);
      sqlite4VdbeAddOp3(v, OP_Insert, iParm, regValue, regKey);
      sqlite4VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid, &p->affinity, 1);
      sqlite4ExprCacheAffinityChange(pParse, regRow, 1);
      sqlite4VdbeAddOp3(v, OP_IdxInsert, iParm, regRowid, regKey);
      sqlite4ReleaseTempReg(pParse, regKey);
      sqlite4ReleaseTempReg(pParse, regRes);
      sqlite4ReleaseTempReg(pParse, regValue);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite4VdbeAddOp3(v, OP_Column, iTab, 0, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;

        sqlite4ExprCacheAffinityChange(pParse, pDest->iMem, nColumn);
      }else{
        sqlite4VdbeAddOp1(v, OP_Yield, pDest->iParm);
      }
      break;
    }
  }
  sqlite4ReleaseTempReg(pParse, regRow);
  sqlite4ReleaseTempReg(pParse, regRowid);

  /* The bottom of the loop
  */
  sqlite4VdbeResolveLabel(v, addrContinue);
  if( p->selFlags & SF_UseSorter ){
    sqlite4VdbeAddOp2(v, OP_SorterNext, iTab, addr);
  }else{

    pKeyInfo = sqlite4DbMallocZero(db,
                       sizeof(*pKeyInfo)+nCol*(sizeof(CollSeq*) + 1));
    if( !pKeyInfo ){
      rc = SQLITE4_NOMEM;
      goto multi_select_end;
    }

    pKeyInfo->enc = ENC(db);
    pKeyInfo->nField = (u16)nCol;

    for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
      *apColl = multiSelectCollSeq(pParse, p, i);
      if( 0==*apColl ){
        *apColl = db->pDfltColl;
      }

      p->affinity = 
         sqlite4CompareAffinity(p->pEList->a[0].pExpr, pDest->affinity);
      r1 = sqlite4GetTempReg(pParse);
      r2 = sqlite4GetTempReg(pParse);
      sqlite4VdbeAddOp2(v, OP_MakeKey, pDest->iParm, r2);
      sqlite4VdbeAddOp4(v, OP_MakeRecord, pIn->iMem, 1, r1, &p->affinity, 1);
      sqlite4ExprCacheAffinityChange(pParse, pIn->iMem, 1);
      sqlite4VdbeAddOp3(v, OP_Insert, pDest->iParm, r1, r2);
      sqlite4VdbeAddOp3(v, OP_IdxInsert, pDest->iParm, r1, r2);
      sqlite4ReleaseTempReg(pParse, r1);
      sqlite4ReleaseTempReg(pParse, r2);
      break;
    }

#if 0  /* Never occurs on an ORDER BY query */
    /* If any row exist in the result set, record that fact and abort.

      aPermute[i] = pItem->iOrderByCol - 1;
    }
    pKeyMerge =
      sqlite4DbMallocRaw(db, sizeof(*pKeyMerge)+nOrderBy*(sizeof(CollSeq*)+1));
    if( pKeyMerge ){
      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
      pKeyMerge->nField = (u16)nOrderBy;
      pKeyMerge->enc = ENC(db);
      for(i=0; i<nOrderBy; i++){
        CollSeq *pColl;
        Expr *pTerm = pOrderBy->a[i].pExpr;
        if( pTerm->flags & EP_ExpCollate ){
          pColl = pTerm->pColl;
        }else{
          pColl = multiSelectCollSeq(pParse, p, aPermute[i]);

    pParse->nMem += nExpr + 1;
    sqlite4VdbeAddOp2(v, OP_Integer, 0, regPrev);
    pKeyDup = sqlite4DbMallocZero(db,
                  sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) );
    if( pKeyDup ){
      pKeyDup->aSortOrder = (u8*)&pKeyDup->aColl[nExpr];
      pKeyDup->nField = (u16)nExpr;
      pKeyDup->enc = ENC(db);
      for(i=0; i<nExpr; i++){
        pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
        pKeyDup->aSortOrder[i] = 0;
      }
    }
  }
 

  sqlite4VdbeAddOp2(v, OP_Gosub, regAddrB, addrSelectB);
  sqlite4VdbeAddOp2(v, OP_If, regEofA, addrEofA);
  sqlite4VdbeAddOp2(v, OP_If, regEofB, addrEofB);

  /* Implement the main merge loop
  */
  sqlite4VdbeResolveLabel(v, labelCmpr);
  sqlite4VdbeAddOp4(v, OP_Permutation, nOrderBy, 0, 0,
  sqlite4VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
                    (char*)aPermute, P4_INTARRAY);
  sqlite4VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, nOrderBy,
                         (char*)pKeyMerge, P4_KEYINFO_HANDOFF);
  sqlite4VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);

  /* Jump to the this point in order to terminate the query.
  */
  sqlite4VdbeResolveLabel(v, labelEnd);

  }

  /* Aggregate and non-aggregate queries are handled differently */
  if( !isAgg && pGroupBy==0 ){
    ExprList *pDist = (isDistinct ? p->pEList : 0);

    /* Begin the database scan. */
    pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, pOrderBy, pDist, 0, 0);
    pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, &pOrderBy, pDist, 0);
    if( pWInfo==0 ) goto select_end;
    if( sqlite4WhereOutputRowCount(pWInfo)<p->nSelectRow ){
      p->nSelectRow = sqlite4WhereOutputRowCount(pWInfo);
    if( pWInfo->nRowOut < p->nSelectRow ) p->nSelectRow = pWInfo->nRowOut;
    }
    if( pOrderBy && sqlite4WhereIsOrdered(pWInfo) ) pOrderBy = 0;

    /* If sorting index that was created by a prior OP_OpenEphemeral 
    ** instruction ended up not being needed, then change the OP_OpenEphemeral
    ** into an OP_Noop.
    */
    if( addrSortIndex>=0 && pOrderBy==0 ){
      sqlite4VdbeChangeToNoop(v, addrSortIndex);
      p->addrOpenEphm[2] = -1;
    }

    if( sqlite4WhereIsDistinct(pWInfo) ){
    if( pWInfo->eDistinct ){
      VdbeOp *pOp;                /* No longer required OpenEphemeral instr. */
     
      assert( addrDistinctIndex>=0 );
      pOp = sqlite4VdbeGetOp(v, addrDistinctIndex);

      assert( isDistinct );
      assert( sqlite4WhereIsDistinct(pWInfo)==WHERE_DISTINCT_ORDERED 
           || sqlite4WhereIsDistinct(pWInfo)==WHERE_DISTINCT_UNIQUE 
      assert( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED 
           || pWInfo->eDistinct==WHERE_DISTINCT_UNIQUE 
      );
      distinct = -1;
      if( sqlite4WhereIsDistinct(pWInfo)==WHERE_DISTINCT_ORDERED ){
      if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED ){
        int iJump;
        int iExpr;
        int iFlag = ++pParse->nMem;
        int iBase = pParse->nMem+1;
        int iBase2 = iBase + pEList->nExpr;
        pParse->nMem += (pEList->nExpr*2);

        sqlite4VdbeAddOp2(v, OP_If, iFlag, iJump-1);
        for(iExpr=0; iExpr<pEList->nExpr; iExpr++){
          CollSeq *pColl = sqlite4ExprCollSeq(pParse, pEList->a[iExpr].pExpr);
          sqlite4VdbeAddOp3(v, OP_Ne, iBase+iExpr, iJump, iBase2+iExpr);
          sqlite4VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
          sqlite4VdbeChangeP5(v, SQLITE4_NULLEQ);
        }
        sqlite4VdbeAddOp2(v, OP_Goto, 0, sqlite4WhereContinueLabel(pWInfo));
        sqlite4VdbeAddOp2(v, OP_Goto, 0, pWInfo->iContinue);

        sqlite4VdbeAddOp2(v, OP_Integer, 0, iFlag);
        assert( sqlite4VdbeCurrentAddr(v)==iJump );
        sqlite4VdbeAddOp3(v, OP_Move, iBase, iBase2, pEList->nExpr);
      }else{
        pOp->opcode = OP_Noop;
      }
    }

    /* Use the standard inner loop. */
    selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, pDest,
        sqlite4WhereContinueLabel(pWInfo), sqlite4WhereBreakLabel(pWInfo)
                    pWInfo->iContinue, pWInfo->iBreak);
    );

    /* End the database scan loop.
    */
    sqlite4WhereEnd(pWInfo);
  }else{
    /* This is the processing for aggregate queries */
    NameContext sNC;    /* Name context for processing aggregate information */

      /* Begin a loop that will extract all source rows in GROUP BY order.
      ** This might involve two separate loops with an OP_Sort in between, or
      ** it might be a single loop that uses an index to extract information
      ** in the right order to begin with.
      */
      sqlite4VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
      pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, 0, 0);
      pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, &pGroupBy, 0, 0);
      if( pWInfo==0 ) goto select_end;
      if( sqlite4WhereIsOrdered(pWInfo) ){
      if( pGroupBy==0 ){
        /* The optimizer is able to deliver rows in group by order so
        ** we do not have to sort.  The OP_OpenEphemeral table will be
        ** cancelled later because we still need to use the pKeyInfo.
        ** cancelled later because we still need to use the pKeyInfo
        */
        pGroupBy = p->pGroupBy;
        groupBySort = 0;

        /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
        ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
        ** Then compare the current GROUP BY terms against the GROUP BY terms
        ** from the previous row currently stored in a0, a1, a2...
        */

          sqlite4VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
          sqlite4ReleaseTempRange(pParse, regBase, nCol);
        }

        /* Insert the key/value into the sorting index and end the loop
        ** generated by where.c code.  */
        sqlite4VdbeAddOp3(
            v, OP_Insert, sAggInfo.sortingIdx, regRecord, regKey
            v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord, regKey
        );
        sqlite4WhereEnd(pWInfo);

        sqlite4VdbeAddOp2(v, OP_Null, 0, regKey);
        sqlite4VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;

        }
  
        /* This case runs if the aggregate has no GROUP BY clause.  The
        ** processing is much simpler since there is only a single row
        ** of output.
        */
        resetAccumulator(pParse, &sAggInfo);
        pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, pMinMax, 0,flag,0);
        pWInfo = sqlite4WhereBegin(pParse, pTabList, pWhere, &pMinMax, 0, flag);
        if( pWInfo==0 ){
          sqlite4ExprListDelete(db, pDel);
          goto select_end;
        }
        updateAccumulator(pParse, &sAggInfo);
        if( sqlite4WhereIsOrdered(pWInfo) && flag ){
          sqlite4VdbeAddOp2(v, OP_Goto, 0, sqlite4WhereBreakLabel(pWInfo));
        if( !pMinMax && flag ){
          sqlite4VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak);
          VdbeComment((v, "%s() by index",
                (flag==WHERE_ORDERBY_MIN?"min":"max")));
        }
        sqlite4WhereEnd(pWInfo);
        finalizeAggFunctions(pParse, &sAggInfo);
      }

#define SQLITE4_MISMATCH    20   /* Data type mismatch */
#define SQLITE4_MISUSE      21   /* Library used incorrectly */
#define SQLITE4_NOLFS       22   /* Uses OS features not supported on host */
#define SQLITE4_AUTH        23   /* Authorization denied */
#define SQLITE4_FORMAT      24   /* Auxiliary database format error */
#define SQLITE4_RANGE       25   /* 2nd param to sqlite4_bind out of range */
#define SQLITE4_NOTADB      26   /* File opened that is not a database file */
#define SQLITE4_NOTICE      27   /* Notifications from sqlite4_log() */
#define SQLITE4_WARNING     28   /* Warnings from sqlite4_log() */
#define SQLITE4_ROW         100  /* sqlite4_step() has another row ready */
#define SQLITE4_DONE        101  /* sqlite4_step() has finished executing */
#define SQLITE4_INEXACT     102  /* xSeek method of storage finds nearby ans */

/*
** CAPIREF: Extended Result Codes
** KEYWORDS: {extended error code} {extended error codes}

#define SQLITE4_IOERR_SEEK              (SQLITE4_IOERR | (22<<8))
#define SQLITE4_LOCKED_SHAREDCACHE      (SQLITE4_LOCKED |  (1<<8))
#define SQLITE4_BUSY_RECOVERY           (SQLITE4_BUSY   |  (1<<8))
#define SQLITE4_CANTOPEN_NOTEMPDIR      (SQLITE4_CANTOPEN | (1<<8))
#define SQLITE4_CORRUPT_VTAB            (SQLITE4_CORRUPT | (1<<8))
#define SQLITE4_READONLY_RECOVERY       (SQLITE4_READONLY | (1<<8))
#define SQLITE4_READONLY_CANTLOCK       (SQLITE4_READONLY | (2<<8))
#define SQLITE4_WARNING_AUTOINDEX       (SQLITE4_WARNING | (1<<8))

/*
** CAPIREF: Flags For File Open Operations
**
** These bit values are intended for use as options in the
** [sqlite4_open()] interface
*/

**
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

#define SQLITE4_OMIT_PROGRESS_CALLBACK 1
#define SQLITE4_OMIT_VIRTUALTABLE 1
#define SQLITE4_OMIT_XFER_OPT 1
#define SQLITE4_OMIT_LOCALTIME 1

/*
** These #defines should enable >2GB file support on POSIX if the
** underlying operating system supports it.  If the OS lacks
** large file support, or if the OS is windows, these should be no-ops.
**

#include "hash.h"
#include "parse.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stddef.h>
#include <ctype.h>    /* FIXME - can we omit this one? */

/*
** If compiling for a processor that lacks floating point support,
** substitute integer for floating-point
*/
#ifdef SQLITE4_OMIT_FLOATING_POINT
# define double sqlite4_int64

** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
#endif

/* 
** Macros to compute minimum and maximum of two numbers.
*/
#define MIN(A,B) ((A)<(B)?(A):(B))
#define MAX(A,B) ((A)>(B)?(A):(B))

/*
** Check to see if this machine uses EBCDIC.  (Yes, believe it or
** not, there are still machines out there that use EBCDIC.)
*/
#if 'A' == '\301'
# define SQLITE4_EBCDIC 1
#else

#define MASTER_NAME       "sqlite_master"
#define TEMP_MASTER_NAME  "sqlite_temp_master"

/*
** The root-page of the master database table.
*/
#define MASTER_ROOT       1
#define KVSTORE_ROOT      0x7fffffff

#define IsKvstore(pTab) ((pTab)->pIndex && (pTab)->pIndex->tnum==KVSTORE_ROOT)

/*
** The name of the schema table.
*/
#define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)

/*
** A convenience macro that returns the number of elements in
** an array.
*/
#define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))

/*
** Determine if the argument is a power of two
*/
#define IsPowerOfTwo(X) (((X)&((X)-1))==0)

/*
** The following macros are used to suppress compiler warnings and to
** make it clear to human readers when a function parameter is deliberately 
** left unused within the body of a function. This usually happens when
** a function is called via a function pointer. For example the 
** implementation of an SQL aggregate step callback may not use the
** parameter indicating the number of arguments passed to the aggregate,

typedef struct SrcListItem SrcListItem;
typedef struct StrAccum StrAccum;
typedef struct Table Table;
typedef struct Token Token;
typedef struct Trigger Trigger;
typedef struct TriggerPrg TriggerPrg;
typedef struct TriggerStep TriggerStep;
typedef struct UnpackedRecord UnpackedRecord;
typedef struct VTable VTable;
typedef struct VtabCtx VtabCtx;
typedef struct Walker Walker;
typedef struct WherePlan WherePlan;
typedef struct WhereInfo WhereInfo;
typedef struct WhereLevel WhereLevel;

#define SQLITE4_IndexCover     0x10     /* Disable index covering table */
#define SQLITE4_GroupByOrder   0x20     /* Disable GROUPBY cover of ORDERBY */
#define SQLITE4_FactorOutConst 0x40     /* Disable factoring out constants */
#define SQLITE4_IdxRealAsInt   0x80     /* Store REAL as INT in indices */
#define SQLITE4_DistinctOpt    0x80     /* DISTINCT using indexes */
#define SQLITE4_OptMask        0xff     /* Mask of all disablable opts */

/*
** Some new things pulled in from SQLite3 use these macros. todo: Replace
** them with working versions.
*/
#define OptimizationDisabled(db, mask)  0
#define OptimizationEnabled(db, mask)  1

/*
** Possible values for the sqlite.magic field.
** The numbers are obtained at random and have no special meaning, other
** than being distinct from one another.
*/
#define SQLITE4_MAGIC_OPEN    0x4d06c919  /* Database is open */
#define SQLITE4_MAGIC_CLOSED  0x5f2246b4  /* Database is closed */

*/
struct Column {
  char *zName;     /* Name of this column */
  Expr *pDflt;     /* Default value of this column */
  char *zDflt;     /* Original text of the default value */
  char *zType;     /* Data type for this column */
  char *zColl;     /* Collating sequence.  If NULL, use the default */
  u16 iPrimKey;    /* Index of in the primary key.  0 if not part of PK */
  u8 notNull;      /* True if there is a NOT NULL constraint */
  u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
  char affinity;   /* One of the SQLITE4_AFF_... values */
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  u8 isHidden;     /* True if this column is 'hidden' */
#endif
};

/*

/*
** An instance of the following structure describes an index key.  It 
** includes information such as sort order and collating sequence for
** each key, and the number of primary key fields appended to the end.
*/
struct KeyInfo {
  sqlite4 *db;        /* The database connection */
  u8 enc;             /* Text encoding - one of the SQLITE4_UTF* values */
  u16 nField;         /* Total number of entries in aColl[] */
  u16 nPK;            /* Number of primary key entries at the end of aColl[] */
  u16 nData;          /* Number of columns of data in KV entry value */
  u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
  CollSeq *aColl[1];  /* Collating sequence for each term of the key */
};

/*
** An instance of the following structure holds information about a
** single index record that has already been parsed out into individual
** values.
**
** A record is an object that contains one or more fields of data.
** Records are used to store the content of a table row and to store
** the key of an index.  A blob encoding of a record is created by
** the OP_MakeRecord opcode of the VDBE and is disassembled by the
** OP_Column opcode.
**
** This structure holds a record that has already been disassembled
** into its constituent fields.
*/
struct UnpackedRecord {
  KeyInfo *pKeyInfo;  /* Collation and sort-order information */
  u16 nField;         /* Number of entries in apMem[] */
  u8 flags;           /* Boolean settings.  UNPACKED_... below */
  i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
  Mem *aMem;          /* Values */
};

/*
** Allowed values of UnpackedRecord.flags
*/
#define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
#define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
#define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */

/*
** Each SQL index is represented in memory by an
** instance of the following structure.
**
** The columns of the table that are to be indexed are described
** by the aiColumn[] field of this structure.  For example, suppose
** we have the following table and index:

** algorithm to employ whenever an attempt is made to insert a non-unique
** element.
*/
struct Index {
  char *zName;     /* Name of this index */
  int nColumn;     /* Number of columns in the table used by this index */
  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
  int nCover;      /* Number of covering columns in this index */
  int *aiCover;    /* Which columns are covered by this index */
  tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
  Table *pTable;   /* The SQL table being indexed */
  int tnum;        /* Page containing root of this index in database file */
  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  u8 eIndexType;   /* SQLITE4_INDEX_USER, UNIQUE or PRIMARYKEY */
  u8 fIndex;       /* One or more of the IDX_* flags below */
  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */
#ifdef SQLITE4_ENABLE_STAT3
  int nSample;             /* Number of elements in aSample[] */
  tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
#endif
  Fts5Index *pFts; /* Fts5 data (or NULL if this is not an fts index) */

  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
};

/* Index.eIndexType must be set to one of the following. */
#define SQLITE4_INDEX_USER       0 /* Index created by CREATE INDEX statement */
#define SQLITE4_INDEX_UNIQUE     1 /* Index created by UNIQUE constraint */
#define SQLITE4_INDEX_PRIMARYKEY 2 /* Index is the tables PRIMARY KEY */
#define SQLITE4_INDEX_FTS5       3 /* Index is an FTS5 index */

**
** The jointype starts out showing the join type between the current table
** and the next table on the list.  The parser builds the list this way.
** But sqlite4SrcListShiftJoinType() later shifts the jointypes so that each
** jointype expresses the join between the table and the previous table.
**
** In the colUsed field, the high-order bit (bit 63) is set if the table
** contains more than 63 columns and the 64-th or later column is used, or
** contains more than 63 columns and the 64-th or later column is used.
** if the table uses an implicit primary key and it is accessed.
*/
struct SrcList {
  i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
  i16 nAlloc;      /* Number of entries allocated in a[] below */
  SrcListItem a[1]; /* One entry for each identifier on the list */
};

  union {
    Index *pIdx;                   /* Index when WHERE_INDEXED is true */
    struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
    sqlite4_index_info *pVtabIdx;  /* Virtual table index to use */
  } u;
};

#if 0
/*
** For each nested loop in a WHERE clause implementation, the WhereInfo
** structure contains a single instance of this structure.  This structure
** is intended to be private the the where.c module and should not be
** access or modified by other modules.
**
** The pIdxInfo field is used to help pick the best index on a

  ** we need a place to cache virtual table index information for each
  ** virtual table in the FROM clause and the WhereLevel structure is
  ** a convenient place since there is one WhereLevel for each FROM clause
  ** element.
  */
  sqlite4_index_info *pIdxInfo;  /* Index info for n-th source table */
};
#endif

#if 0
/*
** Flags appropriate for the wctrlFlags parameter of sqlite4WhereBegin()
** and the WhereInfo.wctrlFlags member.
*/
#define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
#define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
#define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
#define WHERE_NO_AUTOINDEX     0x0020 /* Do not use an auto-index search */
#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
#define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
#endif


/*
** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
** and the WhereInfo.wctrlFlags member.
*/
#define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
#define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
#define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
#define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
#define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
#define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
#define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
#define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
#define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */



/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
#if 0
struct WhereInfo {
  Parse *pParse;       /* Parsing and code generating context */
  u16 wctrlFlags;      /* Flags originally passed to sqlite4WhereBegin() */
  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
  u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
  u8 eDistinct;
  SrcList *pTabList;             /* List of tables in the join */
  int iTop;                      /* The very beginning of the WHERE loop */
  int iContinue;                 /* Jump here to continue with next record */
  int iBreak;                    /* Jump here to break out of the loop */
  int nLevel;                    /* Number of nested loop */
  struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
  double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
  double nRowOut;                /* Estimated number of output rows */
  WhereLevel a[1];               /* Information about each nest loop in WHERE */
};
#endif

#define WHERE_DISTINCT_NOOP      0
#define WHERE_DISTINCT_UNIQUE    1
#define WHERE_DISTINCT_UNIQUE 1
#define WHERE_DISTINCT_ORDERED 2
#define WHERE_DISTINCT_ORDERED   2
#define WHERE_DISTINCT_UNORDERED 3

/*
** A NameContext defines a context in which to resolve table and column
** names.  The context consists of a list of tables (the pSrcList) field and
** a list of named expression (pEList).  The named expression list may
** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
** to the table being operated on by INSERT, UPDATE, or DELETE.  The

** SQLITE4_ENABLE_FTS3 macro.  But to avoid confusion we also all
** the SQLITE4_ENABLE_FTS4 macro to serve as an alisse for SQLITE4_ENABLE_FTS3.
*/
#if defined(SQLITE4_ENABLE_FTS4) && !defined(SQLITE4_ENABLE_FTS3)
# define SQLITE4_ENABLE_FTS3
#endif

/*
** The ctype.h header is needed for non-ASCII systems.  It is also
** needed by FTS3 when FTS3 is included in the amalgamation.
*/
#if !defined(SQLITE4_ASCII) || \
    (defined(SQLITE4_ENABLE_FTS3) && defined(SQLITE4_AMALGAMATION))
# include <ctype.h>
#endif

/*
** The following macros mimic the standard library functions toupper(),
** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
** sqlite versions only work for ASCII characters, regardless of locale.
*/
#ifdef SQLITE4_ASCII

  int sqlite4IsNaN(double);
  int sqlite4IsInf(double);
#else
# define sqlite4IsNaN(X)  0
# define sqlite4IsInf(X)  0
#endif

void sqlite4BlobToHex(int, const u8*, char*);
void sqlite4VXPrintf(StrAccum*, int, const char*, va_list);
#ifndef SQLITE4_OMIT_TRACE
void sqlite4XPrintf(StrAccum*, const char*, ...);
#endif
char *sqlite4MPrintf(sqlite4*,const char*, ...);
char *sqlite4VMPrintf(sqlite4*,const char*, va_list);
char *sqlite4MAppendf(sqlite4*,char*,const char*,...);

                                      Token*, Select*, Expr*, IdList*);
void sqlite4SrcListIndexedBy(Parse *, SrcList *, Token *);
int sqlite4IndexedByLookup(Parse *, SrcListItem *);
void sqlite4SrcListShiftJoinType(SrcList*);
void sqlite4SrcListAssignCursors(Parse*, SrcList*);
void sqlite4IdListDelete(sqlite4*, IdList*);
void sqlite4SrcListDelete(sqlite4*, SrcList*);
Index *sqlite4CreateIndex(Parse*,CreateIndex*,ExprList*,IdList*,int,Token*,int,int);
Index *sqlite4CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                        Token*, int, int, int);
void sqlite4DropIndex(Parse*, SrcList*, int);
int sqlite4Select(Parse*, Select*, SelectDest*);
Select *sqlite4SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,int,Expr*,Expr*);
void sqlite4SelectDelete(sqlite4*, Select*);
Table *sqlite4SrcListLookup(Parse*, SrcList*);
int sqlite4IsReadOnly(Parse*, Table*, int);
void sqlite4OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE4_ENABLE_UPDATE_DELETE_LIMIT) \
    && !defined(SQLITE4_OMIT_SUBQUERY)
Expr *sqlite4LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
#endif
void sqlite4DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite4Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite4WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
WhereInfo *sqlite4WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);

void sqlite4WhereEnd(WhereInfo*);
u64 sqlite4WhereOutputRowCount(WhereInfo*);
int sqlite4WhereIsDistinct(WhereInfo*);
int sqlite4WhereIsOrdered(WhereInfo*);
int sqlite4WhereContinueLabel(WhereInfo*);
int sqlite4WhereBreakLabel(WhereInfo*);
int sqlite4WhereOkOnePass(WhereInfo*);
int sqlite4ExprCodeGetColumn(Parse*, Table*, int, int, int);
void sqlite4ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
void sqlite4ExprCodeMove(Parse*, int, int, int);
void sqlite4ExprCodeCopy(Parse*, int, int, int);
void sqlite4ExprCacheStore(Parse*, int, int, int);
void sqlite4ExprCachePush(Parse*);
void sqlite4ExprCachePop(Parse*, int);

int sqlite4RunVacuum(char**, sqlite4*);
char *sqlite4NameFromToken(sqlite4*, Token*);
int sqlite4ExprCompare(Expr*, Expr*);
int sqlite4ExprListCompare(ExprList*, ExprList*);
void sqlite4ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite4ExprAnalyzeAggList(NameContext*,ExprList*);
Vdbe *sqlite4GetVdbe(Parse*);
void sqlite4PrngSaveState(void);
void sqlite4PrngRestoreState(void);
void sqlite4PrngResetState(void);
void sqlite4CodeVerifySchema(Parse*, int);
void sqlite4CodeVerifyNamedSchema(Parse*, const char *zDb);
void sqlite4BeginTransaction(Parse*, int);
void sqlite4EndTransaction(Parse *, int);
void sqlite4Savepoint(Parse*, int, Token*);
void sqlite4CloseSavepoints(sqlite4 *);
int sqlite4ExprIsConstant(Expr*);
int sqlite4ExprIsConstantNotJoin(Expr*);
int sqlite4ExprIsConstantOrFunction(Expr*);
int sqlite4ExprIsInteger(Expr*, int*);
int sqlite4ExprCanBeNull(const Expr*);
void sqlite4ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
int sqlite4ExprNeedsNoAffinityChange(const Expr*, char);
void sqlite4GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
void sqlite4GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
void sqlite4EncodeIndexKey(Parse *, Index *, int, Index *, int, int, int);
void sqlite4EncodeIndexValue(Parse*, int, Index*, int);
void sqlite4GenerateConstraintChecks(Parse*,Table*,int,int,
                                     int*,int,int,int,int,int*);
void sqlite4CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
int sqlite4OpenTableAndIndices(Parse*, Table*, int, int);
void sqlite4BeginWriteOperation(Parse*, int, int);
void sqlite4MultiWrite(Parse*);
void sqlite4MayAbort(Parse*);

void sqlite4Detach(Parse*, Expr*);
int sqlite4FixInit(DbFixer*, Parse*, int, const char*, const Token*);
int sqlite4FixSrcList(DbFixer*, SrcList*);
int sqlite4FixSelect(DbFixer*, Select*);
int sqlite4FixExpr(DbFixer*, Expr*);
int sqlite4FixExprList(DbFixer*, ExprList*);
int sqlite4FixTriggerStep(DbFixer*, TriggerStep*);
int sqlite4AtoF(const char *z, double*, int, u8);
int sqlite4GetInt32(const char *, int*);
int sqlite4Atoi(const char*);
int sqlite4Utf16ByteLen(const void *pData, int nChar);
int sqlite4Utf8CharLen(const char *pData, int nByte);
u32 sqlite4Utf8Read(const char*, const char**);

/*
** Routines to read and write variable-length integers.  These used to
** be defined locally, but now we use the varint routines in the util.c
** file.  Code should use the MACRO forms below, as the Varint32 versions
** are coded to assume the single byte case is already handled (which 
** the MACRO form does).
*/
int sqlite4PutVarint(unsigned char*, u64);
int sqlite4PutVarint32(unsigned char*, u32);
u8 sqlite4GetVarint(const unsigned char *, u64 *);
int sqlite4GetVarint32(const unsigned char *, u32 *);
u8 sqlite4GetVarint32(const unsigned char *, u32 *);
int sqlite4VarintLen(u64 v);
int sqlite4GetVarint64(const unsigned char*, int, sqlite4_uint64 *pResult);
int sqlite4PutVarint64(unsigned char*, sqlite4_uint64);

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.

extern const unsigned char sqlite4OpcodeProperty[];
extern const unsigned char sqlite4UpperToLower[];
extern const unsigned char sqlite4CtypeMap[];
extern const Token sqlite4IntTokens[];
extern struct sqlite4_env sqlite4DefaultEnv;
extern struct KVFactory sqlite4BuiltinFactory;
#endif
void sqlite4RootPageMoved(sqlite4*, int, int, int);
void sqlite4Reindex(Parse*, Token*, Token*);
void sqlite4AlterFunctions(sqlite4_env*);
void sqlite4AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite4GetToken(const unsigned char *, int *);
void sqlite4NestedParse(Parse*, const char*, ...);
void sqlite4ExpirePreparedStatements(sqlite4*);
int sqlite4CodeSubselect(Parse *, Expr *, int);
int sqlite4CodeSubselect(Parse *, Expr *, int, int);
void sqlite4SelectPrep(Parse*, Select*, NameContext*);
int sqlite4ResolveExprNames(NameContext*, Expr*);
void sqlite4ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite4ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite4ColumnDefault(Vdbe *, Table *, int, int);
void sqlite4AlterFinishAddColumn(Parse *, Token *);
void sqlite4AlterBeginAddColumn(Parse *, SrcList *);

*/
void *sqlite4ParserAlloc(void*(*)(void*,size_t), void*);
void sqlite4ParserFree(void*, void(*)(void*,void*));
void sqlite4Parser(void*, int, Token, Parse*);
#ifdef YYTRACKMAXSTACKDEPTH
  int sqlite4ParserStackPeak(void*);
#endif

void sqlite4AutoLoadExtensions(sqlite4*);
#ifndef SQLITE4_OMIT_LOAD_EXTENSION
  void sqlite4CloseExtensions(sqlite4*);
#else
# define sqlite4CloseExtensions(X)
#endif

#ifdef SQLITE4_TEST
  int sqlite4Utf8To8(char*);
#endif

#ifdef SQLITE4_OMIT_VIRTUALTABLE
#  define sqlite4VtabClear(Y)

FuncDef *sqlite4VtabOverloadFunction(sqlite4 *,FuncDef*, int nArg, Expr*);
void sqlite4InvalidFunction(sqlite4_context*,int,sqlite4_value**);
int sqlite4VdbeParameterIndex(Vdbe*, const char*, int);
int sqlite4TransferBindings(sqlite4_stmt *, sqlite4_stmt *);
int sqlite4Reprepare(Vdbe*);
void sqlite4ExprListCheckLength(Parse*, ExprList*, const char*);
CollSeq *sqlite4BinaryCompareCollSeq(Parse *, Expr *, Expr *);
int sqlite4TempInMemory(const sqlite4*);
const char *sqlite4JournalModename(int);
int sqlite4Checkpoint(sqlite4*, int, int, int*, int*);
int sqlite4WalDefaultHook(void*,sqlite4*,const char*,int);

/* Declarations for functions in fkey.c. All of these are replaced by
** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
** key functionality is available. If OMIT_TRIGGER is defined but
** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
** this case foreign keys are parsed, but no other functionality is 
** provided (enforcement of FK constraints requires the triggers sub-system).

#else
  #define sqlite4BeginBenignMalloc(X)
  #define sqlite4EndBenignMalloc(X)
#endif

#define IN_INDEX_ROWID           1
#define IN_INDEX_EPH             2
#define IN_INDEX_INDEX_ASC       3
#define IN_INDEX_INDEX           3
#define IN_INDEX_INDEX_DESC      4
int sqlite4FindInIndex(Parse *, Expr *, int*, int*);
int sqlite4FindInIndex(Parse *, Expr *, int*);
Index *sqlite4FindExistingInIndex(Parse *, Expr *, int);


#if SQLITE4_MAX_EXPR_DEPTH>0
  void sqlite4ExprSetHeight(Parse *pParse, Expr *p);
  int sqlite4SelectExprHeight(Select *);
  int sqlite4ExprCheckHeight(Parse*, int);

  **
  ** There is one exception to the above: If static analysis of the WHERE 
  ** clause indicates that the loop will visit at most one row, then the
  ** RowSet object is bypassed and the primary key of the single row (if
  ** any) left in register regOldKey. This is called the "one-pass"
  ** approach. Set okOnePass to true if it can be used in this case.  */
  sqlite4VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldKey);
  pWInfo = sqlite4WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
  pWInfo = sqlite4WhereBegin(pParse, pSrc, pWhere, 0, 0, WHERE_ONEPASS_DESIRED);
  if( pWInfo==0 ) goto update_cleanup;
  okOnePass = sqlite4WhereOkOnePass(pWInfo);
  okOnePass = pWInfo->okOnePass;
  sqlite4VdbeAddOp2(v, OP_RowKey, iCur+iPk, regOldKey);
  if( !okOnePass ){
    sqlite4VdbeAddOp3(v, OP_RowSetAdd, regRowSet, 0, regOldKey);
  }
  sqlite4WhereEnd(pWInfo);

  /* Open every index that needs updating. If any index could potentially 

    ** character. Two bytes are required in the output buffer for the
    ** nul-terminator.  */
    if( n<0 ){
      u8 *z = (u8*)p;
      while( z[0] || z[1] ) z += 2;
      n = z - (u8*)p;
    }
    nReq = n * 2 + 2;
    nReq = n * 2 + 1;
  }else{
    /* When converting from UTF-16, the maximum growth results from
    ** translating a 2-byte character to a 4-byte UTF-8 character.
    ** A single byte is required for the output string
    ** nul-terminator.  */
    if( n<0 ) n = sqlite4Strlen30(p);
    nReq = n * 2 + 1;

** string is not an integer, just return 0.
*/
int sqlite4Atoi(const char *z){
  int x = 0;
  if( z ) sqlite4GetInt32(z, &x);
  return x;
}

/*
** The variable-length integer encoding is as follows:
**
** KEY:
**         A = 0xxxxxxx    7 bits of data and one flag bit
**         B = 1xxxxxxx    7 bits of data and one flag bit
**         C = xxxxxxxx    8 bits of data
**
**  7 bits - A
** 14 bits - BA
** 21 bits - BBA
** 28 bits - BBBA
** 35 bits - BBBBA
** 42 bits - BBBBBA
** 49 bits - BBBBBBA
** 56 bits - BBBBBBBA
** 64 bits - BBBBBBBBC
*/

/*
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data write will be between 1 and 9 bytes.  The number
** of bytes written is returned.
**
** A variable-length integer consists of the lower 7 bits of each byte
** for all bytes that have the 8th bit set and one byte with the 8th
** bit clear.  Except, if we get to the 9th byte, it stores the full
** 8 bits and is the last byte.
*/
int sqlite4PutVarint(unsigned char *p, u64 v){
  int i, j, n;
  u8 buf[10];
  if( v & (((u64)0xff000000)<<32) ){
    p[8] = (u8)v;
    v >>= 8;
    for(i=7; i>=0; i--){
      p[i] = (u8)((v & 0x7f) | 0x80);
      v >>= 7;
    }
    return 9;
  }    
  n = 0;
  do{
    buf[n++] = (u8)((v & 0x7f) | 0x80);
    v >>= 7;
  }while( v!=0 );
  buf[0] &= 0x7f;
  assert( n<=9 );
  for(i=0, j=n-1; j>=0; j--, i++){
    p[i] = buf[j];
  }
  return n;
}

/*
** This routine is a faster version of sqlite4PutVarint() that only
** works for 32-bit positive integers and which is optimized for
** the common case of small integers.  A MACRO version, putVarint32,
** is provided which inlines the single-byte case.  All code should use
** the MACRO version as this function assumes the single-byte case has
** already been handled.
*/
int sqlite4PutVarint32(unsigned char *p, u32 v){
#ifndef putVarint32
  if( (v & ~0x7f)==0 ){
    p[0] = v;
    return 1;
  }
#endif
  if( (v & ~0x3fff)==0 ){
    p[0] = (u8)((v>>7) | 0x80);
    p[1] = (u8)(v & 0x7f);
    return 2;
  }
  return sqlite4PutVarint(p, v);
}

/*
** Bitmasks used by sqlite4GetVarint().  These precomputed constants
** are defined here rather than simply putting the constant expressions
** inline in order to work around bugs in the RVT compiler.
**
** SLOT_2_0     A mask for  (0x7f<<14) | 0x7f
**
** SLOT_4_2_0   A mask for  (0x7f<<28) | SLOT_2_0
*/
#define SLOT_2_0     0x001fc07f
#define SLOT_4_2_0   0xf01fc07f


/*
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read.  The value is stored in *v.
*/
u8 sqlite4GetVarint(const unsigned char *p, u64 *v){
  u32 a,b,s;

  a = *p;
  /* a: p0 (unmasked) */
  if (!(a&0x80))
  {
    *v = a;
    return 1;
  }

  p++;
  b = *p;
  /* b: p1 (unmasked) */
  if (!(b&0x80))
  {
    a &= 0x7f;
    a = a<<7;
    a |= b;
    *v = a;
    return 2;
  }

  /* Verify that constants are precomputed correctly */
  assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );
  assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) );

  p++;
  a = a<<14;
  a |= *p;
  /* a: p0<<14 | p2 (unmasked) */
  if (!(a&0x80))
  {
    a &= SLOT_2_0;
    b &= 0x7f;
    b = b<<7;
    a |= b;
    *v = a;
    return 3;
  }

  /* CSE1 from below */
  a &= SLOT_2_0;
  p++;
  b = b<<14;
  b |= *p;
  /* b: p1<<14 | p3 (unmasked) */
  if (!(b&0x80))
  {
    b &= SLOT_2_0;
    /* moved CSE1 up */
    /* a &= (0x7f<<14)|(0x7f); */
    a = a<<7;
    a |= b;
    *v = a;
    return 4;
  }

  /* a: p0<<14 | p2 (masked) */
  /* b: p1<<14 | p3 (unmasked) */
  /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
  /* moved CSE1 up */
  /* a &= (0x7f<<14)|(0x7f); */
  b &= SLOT_2_0;
  s = a;
  /* s: p0<<14 | p2 (masked) */

  p++;
  a = a<<14;
  a |= *p;
  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
  if (!(a&0x80))
  {
    /* we can skip these cause they were (effectively) done above in calc'ing s */
    /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
    /* b &= (0x7f<<14)|(0x7f); */
    b = b<<7;
    a |= b;
    s = s>>18;
    *v = ((u64)s)<<32 | a;
    return 5;
  }

  /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
  s = s<<7;
  s |= b;
  /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  p++;
  b = b<<14;
  b |= *p;
  /* b: p1<<28 | p3<<14 | p5 (unmasked) */
  if (!(b&0x80))
  {
    /* we can skip this cause it was (effectively) done above in calc'ing s */
    /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
    a &= SLOT_2_0;
    a = a<<7;
    a |= b;
    s = s>>18;
    *v = ((u64)s)<<32 | a;
    return 6;
  }

  p++;
  a = a<<14;
  a |= *p;
  /* a: p2<<28 | p4<<14 | p6 (unmasked) */
  if (!(a&0x80))
  {
    a &= SLOT_4_2_0;
    b &= SLOT_2_0;
    b = b<<7;
    a |= b;
    s = s>>11;
    *v = ((u64)s)<<32 | a;
    return 7;
  }

  /* CSE2 from below */
  a &= SLOT_2_0;
  p++;
  b = b<<14;
  b |= *p;
  /* b: p3<<28 | p5<<14 | p7 (unmasked) */
  if (!(b&0x80))
  {
    b &= SLOT_4_2_0;
    /* moved CSE2 up */
    /* a &= (0x7f<<14)|(0x7f); */
    a = a<<7;
    a |= b;
    s = s>>4;
    *v = ((u64)s)<<32 | a;
    return 8;
  }

  p++;
  a = a<<15;
  a |= *p;
  /* a: p4<<29 | p6<<15 | p8 (unmasked) */

  /* moved CSE2 up */
  /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */
  b &= SLOT_2_0;
  b = b<<8;
  a |= b;

  s = s<<4;
  b = p[-4];
  b &= 0x7f;
  b = b>>3;
  s |= b;

  *v = ((u64)s)<<32 | a;

  return 9;
}

/*
** Read a 32-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read.  The value is stored in *v.
**
** If the varint stored in p[0] is larger than can fit in a 32-bit unsigned
** integer, then set *v to 0xffffffff.
**
** A MACRO version, getVarint32, is provided which inlines the 
** single-byte case.  All code should use the MACRO version as 
** this function assumes the single-byte case has already been handled.
*/
u8 sqlite4GetVarint32(const unsigned char *p, u32 *v){
  u32 a,b;

  /* The 1-byte case.  Overwhelmingly the most common.  Handled inline
  ** by the getVarin32() macro */
  a = *p;
  /* a: p0 (unmasked) */
#ifndef getVarint32
  if (!(a&0x80))
  {
    /* Values between 0 and 127 */
    *v = a;
    return 1;
  }
#endif

  /* The 2-byte case */
  p++;
  b = *p;
  /* b: p1 (unmasked) */
  if (!(b&0x80))
  {
    /* Values between 128 and 16383 */
    a &= 0x7f;
    a = a<<7;
    *v = a | b;
    return 2;
  }

  /* The 3-byte case */
  p++;
  a = a<<14;
  a |= *p;
  /* a: p0<<14 | p2 (unmasked) */
  if (!(a&0x80))
  {
    /* Values between 16384 and 2097151 */
    a &= (0x7f<<14)|(0x7f);
    b &= 0x7f;
    b = b<<7;
    *v = a | b;
    return 3;
  }

  /* A 32-bit varint is used to store size information in btrees.
  ** Objects are rarely larger than 2MiB limit of a 3-byte varint.
  ** A 3-byte varint is sufficient, for example, to record the size
  ** of a 1048569-byte BLOB or string.
  **
  ** We only unroll the first 1-, 2-, and 3- byte cases.  The very
  ** rare larger cases can be handled by the slower 64-bit varint
  ** routine.
  */
#if 1
  {
    u64 v64;
    u8 n;

    p -= 2;
    n = sqlite4GetVarint(p, &v64);
    assert( n>3 && n<=9 );
    if( (v64 & SQLITE4_MAX_U32)!=v64 ){
      *v = 0xffffffff;
    }else{
      *v = (u32)v64;
    }
    return n;
  }

#else
  /* For following code (kept for historical record only) shows an
  ** unrolling for the 3- and 4-byte varint cases.  This code is
  ** slightly faster, but it is also larger and much harder to test.
  */
  p++;
  b = b<<14;
  b |= *p;
  /* b: p1<<14 | p3 (unmasked) */
  if (!(b&0x80))
  {
    /* Values between 2097152 and 268435455 */
    b &= (0x7f<<14)|(0x7f);
    a &= (0x7f<<14)|(0x7f);
    a = a<<7;
    *v = a | b;
    return 4;
  }

  p++;
  a = a<<14;
  a |= *p;
  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
  if (!(a&0x80))
  {
    /* Values  between 268435456 and 34359738367 */
    a &= SLOT_4_2_0;
    b &= SLOT_4_2_0;
    b = b<<7;
    *v = a | b;
    return 5;
  }

  /* We can only reach this point when reading a corrupt database
  ** file.  In that case we are not in any hurry.  Use the (relatively
  ** slow) general-purpose sqlite4GetVarint() routine to extract the
  ** value. */
  {
    u64 v64;
    u8 n;

    p -= 4;
    n = sqlite4GetVarint(p, &v64);
    assert( n>5 && n<=9 );
    *v = (u32)v64;
    return n;
  }
#endif
}

/*
** Return the number of bytes that will be needed to store the given
** 64-bit integer.
*/
int sqlite4VarintLen(u64 v){
  int i = 0;
  do{
    i++;
    v >>= 7;
  }while( v!=0 && ALWAYS(i<9) );
  return i;
}


/*
** Read or write a four-byte big-endian integer value.
*/
u32 sqlite4Get4byte(const u8 *p){
  return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
}

  }
  z[0] = 255;
  varintWrite32(z+1, w);
  varintWrite32(z+5, y);
  return 9;
}

/*
** Return the number of bytes required to encode value v as a varint.
*/
int sqlite4VarintLen(sqlite4_uint64 v){
  unsigned char aDummy[9];
  return sqlite4PutVarint64(aDummy, v);
}

/*
** Read a varint from buffer z and set *pResult to the value read.
** Return the number of bytes read from the buffer.
*/
int sqlite4GetVarint32(const unsigned char *z, u32 *pResult){
  sqlite4_uint64 iRes;
  int ret;
  ret = sqlite4GetVarint64(z, 9, &iRes);
  *pResult = (u32)iRes;
  return ret;
}

/*
** Encode v as a varint and write the result to buffer p. Return the
** number of bytes written.
*/
int sqlite4PutVarint32(unsigned char *p, u32 v){
  return sqlite4PutVarint64(p, v);
}

/*
** Compile this one file with the -DTEST_VARINT option to run the simple
** test case below.  The test program generates 10 million random 64-bit
** values, weighted toward smaller numbers, and for each value it encodes
** and then decodes the varint to verify that the same number comes back.
** It also checks to make sure the if x<y then memcmp(varint(x),varint(y))<0.
*/

  VdbeCursor *pCx = 0;
  nByte = 
      ROUND8(sizeof(VdbeCursor)) + 
      2*nField*sizeof(u32);

  assert( iCur<p->nCursor );
  if( p->apCsr[iCur] ){
    sqlite4VdbeFreeCursor(p->apCsr[iCur]);
    sqlite4VdbeFreeCursor(p, p->apCsr[iCur]);
    p->apCsr[iCur] = 0;
  }
  if( SQLITE4_OK==sqlite4VdbeMemGrow(pMem, nByte, 0) ){
    p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
    memset(pCx, 0, sizeof(VdbeCursor));
    pCx->db = p->db;
    pCx->iDb = iDb;
    pCx->nField = nField;
    pCx->rowChnged = 1;
    sqlite4_buffer_init(&pCx->sSeekKey, p->db->pEnv->pMM);
  }
  return pCx;
}

/*
** Try to convert a value into a numeric representation if we can
** do so without loss of information.  In other words, if the string

/* Opcode: Integer P1 P2 * * *
**
** The 32-bit integer value P1 is written into register P2.
*/
case OP_Integer: {         /* out2-prerelease */
  pOut->u.num = sqlite4_num_from_int64((i64)pOp->p1);
  MemSetTypeFlag(pOut, MEM_Int);
  break;
}

/* Opcode: Num P1 P2 * P4 *
**
** P4 is a pointer to an sqlite4_num value. Write that value into 
** register P2. Set the register flags to MEM_Int if P1 is non-zero,

        pOut->u.num = sqlite4_num_mul(num1, num2); break;
      case OP_Divide: 
        pOut->u.num = sqlite4_num_div(num2, num1); break;
      default: {
        iA = sqlite4_num_to_int64(num1, 0);
        iB = sqlite4_num_to_int64(num2, 0);
        if( iA==0 ) goto arithmetic_result_is_null;
        if( iA==-1 ) iA = 1;
        pOut->u.num = sqlite4_num_from_int64(iB % iA);
        break;
      }
    }

    if( sqlite4_num_isnan(pOut->u.num) ){
      goto arithmetic_result_is_null;

  /* Undo any changes made by applyAffinity() to the input registers. */
  pIn1->flags = (pIn1->flags&~MEM_TypeMask) | (flags1&MEM_TypeMask);
  pIn3->flags = (pIn3->flags&~MEM_TypeMask) | (flags3&MEM_TypeMask);
  break;
}

/* Opcode: Permutation P1 * * P4 *
/* Opcode: Permutation * * * P4 *
**
** Set the permutation used by the OP_Compare operator to be the array
** of integers in P4.  P4 will contain exactly P1 elements.  The P1
** of integers in P4.
** parameter is used only for printing the P4 array when debugging.
**
** The permutation is only valid until the next OP_Permutation, OP_Compare,
** OP_Halt, or OP_ResultRow.  Typically the OP_Permutation should occur
** immediately prior to the OP_Compare.
*/
case OP_Permutation: {
  assert( pOp->p4type==P4_INTARRAY );

**
** If the OPFLAG_CLEARCACHE bit is set on P5 and P1 is a pseudo-table cursor,
** then the cache of the cursor is reset prior to extracting the column.
** The first OP_Column against a pseudo-table after the value of the content
** register has changed should have this bit set.
*/
case OP_Column: {
  KVCursor *pKVCur;         /* Cursor for current entry in the KV storage */
  ValueDecoder *pCodec;     /* The decoder object */
  int p1;                   /* Index of VdbeCursor to decode */
  int mxField;              /* Maximum column number */
  VdbeCursor *pC;           /* The VDBE cursor */
  Mem *pDest;               /* Where to write the results */
  const KVByteArray *aData; /* The content to be decoded */
  KVSize nData;             /* Size of aData[] in bytes */
  Mem *pDefault;            /* Default value from P4 */
  Mem *pReg;                /* */

  p1 = pOp->p1;
  assert( p1<p->nCursor );
  assert( pOp->p3>0 && pOp->p3<=p->nMem );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  pC = p->apCsr[p1];
  assert( pC!=0 );
  assert( pC->iRoot!=KVSTORE_ROOT );
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  assert( pC->pVtabCursor==0 );
#endif
  pKVCur = pC->pKVCur;
  if( pKVCur!=0 ){
  if( pC->pDecoder==0 ){
    mxField = pC->nField;
    if( pC->pKeyInfo && pC->pKeyInfo->nData ) mxField = pC->pKeyInfo->nData;
    if( pC->nullRow ){
      aData = 0;
    }else{
      rc = sqlite4KVCursorData(pKVCur, 0, -1, &aData, &nData);
    }
  }else if( ALWAYS(pC->pseudoTableReg>0) ){
    pReg = &aMem[pC->pseudoTableReg];
    assert( pReg->flags & MEM_Blob );
    assert( memIsValid(pReg) );
    aData = (const KVByteArray*)pReg->z;
    nData = pReg->n;
  }else{
    aData = 0;
    MemSetTypeFlag(pDest, MEM_Null);
  }
  if( rc==SQLITE4_OK && aData ){
    /* TODO: Fix this somehow... */
    int nField = pC->nField;
    if( pC->pKeyInfo && pC->pKeyInfo->nData ) nField = pC->pKeyInfo->nData;
    rc = sqlite4VdbeDecoderCreate(db, pC, 0, mxField, &pC->pDecoder);
    pC->rowChnged = 1;
  }
  if( rc==SQLITE4_OK ){
    pDefault = (pOp->p4type==P4_MEM) ? pOp->p4.pMem : 0;
    rc = sqlite4VdbeDecoderGetColumn(pC->pDecoder, pOp->p2, pDefault, pDest);

    rc = sqlite4VdbeCreateDecoder(db, aData, nData, nField, &pCodec);
    if( rc==0 ){
      pDefault = (pOp->p4type==P4_MEM) ? pOp->p4.pMem : 0;
      rc = sqlite4VdbeDecodeValue(pCodec, pOp->p2, pDefault, pDest);
      sqlite4VdbeDestroyDecoder(pCodec);
    }
  }else{
    sqlite4VdbeMemSetNull(pDest);
  }
  UPDATE_MAX_BLOBSIZE(pDest);
  REGISTER_TRACE(pOp->p3, pDest);
      assert( rc<100 );
  break;
}

/* Opcode: Affinity P1 P2 * P4 *
**
** Apply affinities to a range of P2 registers starting with P1.
**

  break;
}

/* Opcode: MakeIdxKey P1 P2 P3 P4 P5
**
** P1 is an open cursor. P2 is the first register in a contiguous array
** of N registers containing values to encode into a database key. Normally,
** N is taken from the KeyInfo object of P1.  However, of P4 is a positive
** integer, P4 is used for N instead.
** N is equal to the number of columns indexed by P1, plus the number of 
** trailing primary key columns (if any). 
**
** Or, if P4 is a non-zero integer, then it contains the value for N.
**
** This instruction encodes the N values into a database key and writes
** the result to register P3. No affinity transformations are applied to 
** the input values before they are encoded. 
**
** If the OPFLAG_SEQCOUNT bit of P5 is set, then a sequence number 
** (unique within the cursor) is appended to the record. The sole purpose
** of this is to ensure that the key blob is unique within the cursor table.
** of this is to ensure that the key blob is unique within the cursors table.
**
** If the OPFLAG_PARTIALKEY bit of P5 is set, that means the value supplied
** for N is not the true number of values in the key, only the number that
** need to be encoded for this operation.  This effects the encoding of
** final BLOBs.
*/
case OP_MakeIdxKey: {

  
  pC = p->apCsr[pOp->p1];
  pKeyInfo = pC->pKeyInfo;
  pData0 = &aMem[pOp->p2];
  pOut = &aMem[pOp->p3];
  aRec = 0;

  /* If P4 contains OPFLAG_SEQCOUNT, encode the sequence number blob to be
  ** appended to the end of the key.  Variable nSeq is set to the number
  ** of bytes in the encoded key.  A non-standard encoding is used (not
  /* If pOp->p5 is non-zero, encode the sequence number blob to append to
  ** the end of the key. Variable nSeq is set to the number of bytes in
  ** the encoded key.
  ** the usual varint encoding) so that the OP_GrpCompare opcode can easily
  ** back up over the sequence count to find the true end of the key.
  */
  nSeq = 0;
  if( pOp->p5 & OPFLAG_SEQCOUNT ){
    iSeq = pC->seqCount++;
    do {
      nSeq++;
      aSeq[sizeof(aSeq)-nSeq] = (u8)(iSeq & 0x007F);
      iSeq = iSeq >> 7;
    }while( iSeq );
    aSeq[sizeof(aSeq)-nSeq] |= 0x80;
  }

  memAboutToChange(p, pOut);

  nField = pKeyInfo->nField;
  if( pOp->p4type==P4_INT32 && pOp->p4.i>0 ){
  if( pOp->p4type==P4_INT32 && pOp->p4.i ){
    nField = pOp->p4.i;
    assert( nField<=pKeyInfo->nField );
  }else{
    nField = pKeyInfo->nField;
  }
  rc = sqlite4VdbeEncodeKey(
    db, pData0, nField, pKeyInfo->nField,
    db, pData0, nField, nField+(pOp->p5 & OPFLAG_PARTIALKEY),
    pC->iRoot, pKeyInfo, &aRec, &nRec, nSeq
  );

  if( rc ){
    sqlite4DbFree(db, aRec);
  }else{
    if( nSeq ){

**
** P4 may be a string that is P2 characters long, or it may be NULL. The nth 
** character of the string indicates the column affinity that should be used
** for the nth field of the index key. The mapping from character to affinity
** is given by the SQLITE4_AFF_ macros defined in sqliteInt.h. If P4 is NULL
** then all index fields have the affinity NONE.
**
** If this instruction is immediately preceded by OP_Permutation, then the
** This opcode expands any zero-blobs within the input array. Then if
** specified permutation is used to determine the order that registers are
** used to build the record.  The i-th column of the record is taken from
** register P1+aPermute[i].  If OP_Permutation has not been run, then the i-th
** column comes from register P1+i.
**
** This opcode applies the affinities that it specifies to the input
** array elements. Then, if P3 is not 0, it encodes the input array
** P4 is not NULL it applies the affinities that it specifies to the input
** array elements. Finally, if P3 is not 0, it encodes the input array
** into a data record and stores the result in register P3. The OP_Column 
** opcode can be used to decode the record.
**
** Specifying P3==0 is only useful if the previous opcode is an OP_MakeKey.
*/
case OP_MakeKey:
case OP_MakeRecord: {
  Mem *pData0;           /* First field to be combined into the record */
  Mem *pLast;            /* Last field of the record */
  Mem *pMem;             /* For looping over inputs */
  int nField;            /* Number of fields in the record */
  char *zAffinity;       /* The affinity string for the record */
  VdbeCursor *pC;        /* Cursor to generate key for */
  Mem *pKeyOut;          /* Where to store the generated key */
  int keyReg;            /* Register into which to write the key */
  u8 *aRec;              /* The constructed key or value */
  int nRec;              /* Size of aRec[] in bytes */

  assert( aPermute==0 || pOp->opcode!=OP_MakeKey );
  assert( aPermute==0 || pOp->p4type==P4_NOTUSED );
  assert( aPermute==0 || pOp->p3 );

  if( pOp->opcode==OP_MakeKey ){
    pC = p->apCsr[pOp->p1];
    keyReg = pOp->p2;
    pKeyOut = &aMem[keyReg];
    memAboutToChange(p, pKeyOut);
    assert( pC!=0 );
    assert( pC->pKeyInfo!=0 );
    pc++;
    pOp++;
    assert( pOp->opcode==OP_MakeRecord );
#ifdef SQLITE4_DEBUG
    if( p->trace ) sqlite4VdbePrintOp(p->trace, pc, pOp);
#endif
  }else{
    pC = 0;
  }
  nField = pOp->p1;
  zAffinity = pOp->p4.z;
  assert( pOp->p1>0 && pOp->p2>0 && pOp->p2+pOp->p1<=p->nMem+1 );
  pData0 = &aMem[pOp->p1];
  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem+1 );
  pData0 = &aMem[nField];
  nField = pOp->p2;
  pLast = &pData0[nField-1];

  /* Loop through the input elements.  Apply affinity to each one and
  ** expand all zero-blobs.
  */
  for(pMem=pData0; pMem<=pLast; pMem++){

      rc = sqlite4VdbeMemSetStr(pKeyOut, (char *)aRec, nRec, 0,
                                SQLITE4_DYNAMIC, 0);
      REGISTER_TRACE(keyReg, pKeyOut);
      UPDATE_MAX_BLOBSIZE(pKeyOut);
    }
  }

  /* If P3 is not 0, compute the data record */
  /* If P3 is not 0, compute the data rescord */
  if( rc==SQLITE4_OK && pOp->p3 ){
    assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
    pOut = &aMem[pOp->p3];
    memAboutToChange(p, pOut);
    aRec = 0;
    rc = sqlite4VdbeEncodeData(db, pData0, aPermute, nField, &aRec, &nRec);
    rc = sqlite4VdbeEncodeData(db, pData0, nField, &aRec, &nRec);
    if( rc ){
      sqlite4DbFree(db, aRec);
    }else{
      rc = sqlite4VdbeMemSetStr(pOut, (char *)aRec, nRec, 0, SQLITE4_DYNAMIC,0);
      REGISTER_TRACE(pOp->p3, pOut);
      UPDATE_MAX_BLOBSIZE(pOut);
    }
  }
  aPermute = 0;
  break;
}

/* Opcode: Count P1 P2 * * *
**
** Store the number of entries (an integer value) in the table or index 
** opened by cursor P1 in register P2

        p->nStmtDefCons = db->nDeferredCons;
      }
    }
  }
  break;
}

/* Opcode: ReadCookie P1 P2 * * *
**
** Read the schema cookie from database P1 and write it into register P2.
**
** There must be a read-lock on the database (either a transaction
** must be started or there must be an open cursor) before
** executing this instruction.
*/
case OP_ReadCookie: {               /* out2-prerelease */
  unsigned int iMeta;
  KVStore *pKV;

  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  pKV = db->aDb[pOp->p1].pKV;
  rc = sqlite4KVStoreGetSchema(pKV, &iMeta);
  pOut->u.num = sqlite4_num_from_int64(iMeta);
  MemSetTypeFlag(pOut, MEM_Int);
  break;
}

/* Opcode: SetCookie P1 P2 P3 * *
**
** Write the content of register P3 (interpreted as an integer)
** into cookie number P2 of database P1.  P2==1 is the schema version.  
** P2==2 is the database format. P2==3 is the recommended pager cache 
** size, and so forth.  P1==0 is the main database file and P1==1 is the 
** database file used to store temporary tables.

    if( NEVER(p2<2) ) {
      rc = SQLITE4_CORRUPT_BKPT;
      goto abort_due_to_error;
    }
  }
  if( pOp->p4type==P4_KEYINFO ){
    pKeyInfo = pOp->p4.pKeyInfo;
    pKeyInfo->enc = ENC(p->db);
    nField = pKeyInfo->nField+1;
  }else if( pOp->p4type==P4_INT32 ){
    nField = pOp->p4.i;
  }
  assert( pOp->p1>=0 );
  pCur = allocateCursor(p, pOp->p1, nField, iDb, 1);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  pCur->isOrdered = 1;
  pCur->iRoot = p2;
  rc = sqlite4KVStoreOpenCursor(pX, &pCur->pKVCur);
  pCur->pKeyInfo = pKeyInfo;

  /* Set the VdbeCursor.isTable and isIndex variables. Previous versions of
  ** SQLite used to check if the root-page flags were sane at this point
  ** and report database corruption if they were not, but this check has
  ** since moved into the btree layer.  */  
  pCur->isTable = pOp->p4type!=P4_KEYINFO;
  pCur->isIndex = !pCur->isTable;
  break;
}

/* Opcode: OpenEphemeral P1 P2 * P4 P5
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 

  rc = sqlite4KVStoreOpen(db, "ephm", 0, &pCx->pTmpKV,
          SQLITE4_KVOPEN_TEMPORARY | SQLITE4_KVOPEN_NO_TRANSACTIONS
  );
  if( rc==SQLITE4_OK ) rc = sqlite4KVStoreOpenCursor(pCx->pTmpKV, &pCx->pKVCur);
  if( rc==SQLITE4_OK ) rc = sqlite4KVStoreBegin(pCx->pTmpKV, 2);

  pCx->pKeyInfo = pOp->p4.pKeyInfo;
  if( pCx->pKeyInfo ) pCx->pKeyInfo->enc = ENC(p->db);
  pCx->isIndex = !pCx->isTable;

  pCx->isOrdered = 1;
  break;
}

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

/* Opcode: OpenPseudo P1 P2 P3 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data.  The content of that one row is the content of memory
** register P2.  In other words, cursor P1 becomes an alias for the 
** MEM_Blob content contained in register P2.
**
** A pseudo-table created by this opcode is used to hold a single
** row output from the sorter so that the row can be decomposed into
** individual columns using the OP_Column opcode.  The OP_Column opcode
** is the only cursor opcode that works with a pseudo-table.
**
** P3 is the number of fields in the records that will be stored by
** the pseudo-table.
*/
case OP_OpenPseudo: {
  VdbeCursor *pCx;

  assert( pOp->p1>=0 );
  pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->pseudoTableReg = pOp->p2;
  pCx->isTable = 1;
  pCx->isIndex = 0;
  break;
}

/* Opcode: Close P1 * * * *
**
** Close a cursor previously opened as P1.  If P1 is not
** currently open, this instruction is a no-op.
*/
case OP_Close: {
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  sqlite4VdbeFreeCursor(p->apCsr[pOp->p1]);
  sqlite4VdbeFreeCursor(p, p->apCsr[pOp->p1]);
  p->apCsr[pOp->p1] = 0;
  break;
}

/* Opcode: SeekPk P1 * P3 * *
**
** P1 must be a cursor open on a PRIMARY KEY index. P3 is a cursor open
** on an auxiliary index on the same table. P3 must be pointing to a valid
** index entry.
**
** This opcode seeks cursor P1 so that it points to the PK index entry
** that corresponds to the same table row as the current entry that 
** cursor P3 points to. The entry must exist.
** cursor P3 points to. The entry must exist. If it does not, this opcode
**
** Actually, the seek is deferred until it is actually needed and if the
** PRIMARY KEY index is never referenced, the seek never takes place.  The
** sqlite3VdbeCursorMoveto() does the seek, if necessary.  If the target
** row does not exist in the PRIMARY KEY table, then the
** sqlite3VdbeCursorMoveto() routine will throw an SQLITE4_CORRUPT error.
** throws an SQLITE4_CORRUPT exception.
*/
case OP_SeekPk: {
  KVByteArray *aKey;              /* Key data from cursor pIdx */
  KVSize nKey;                    /* Size of aKey[] in bytes */
  VdbeCursor *pPk;                /* Cursor P1 */
  VdbeCursor *pIdx;               /* Cursor P3 */
  KVByteArray const *aKey;        /* Key data from cursor pIdx */
  KVSize nKey;                    /* Size of aKey[] in bytes */
  int nShort;                     /* Size of aKey[] without PK fields */
  KVByteArray *aPkKey;
  int nVarint;                    /* Size of varint pPk->iRoot */
  KVSize nPkKey;

  pPk = p->apCsr[pOp->p1];
  pIdx = p->apCsr[pOp->p3];

  if( pIdx->pFts ){
    rc = sqlite4Fts5Pk(pIdx->pFts, pPk->iRoot, &aKey, &nKey);
    rc = sqlite4Fts5Pk(pIdx->pFts, pPk->iRoot, &aPkKey, &nPkKey);
    if( rc==SQLITE4_OK ){
      rc = sqlite4KVCursorSeek(pPk->pKVCur, aKey, nKey, 0);
      rc = sqlite4KVCursorSeek(pPk->pKVCur, aPkKey, nPkKey, 0);
      if( rc==SQLITE4_NOTFOUND ) rc = SQLITE4_CORRUPT_BKPT;
      pPk->nullRow = 0;
    }
  }else{
    assert( pIdx->pKeyInfo->nPK>0 );
    assert( pPk->pKeyInfo->nPK==0 );
    rc = sqlite4KVCursorKey(pIdx->pKVCur, (const KVByteArray **)&aKey, &nKey);
    if( rc!=SQLITE4_OK ) break;
    nShort = sqlite4VdbeShortKey(aKey, nKey, 
        pIdx->pKeyInfo->nField - pIdx->pKeyInfo->nPK, 0
    );
    nVarint = sqlite4VarintLen(pPk->iRoot);
    rc = sqlite4_buffer_resize(&pPk->sSeekKey, nVarint + nKey - nShort);
    if( rc!=SQLITE4_OK ) break;
    putVarint32((u8 *)(pPk->sSeekKey.p), pPk->iRoot);
    memcpy(((u8*)pPk->sSeekKey.p) + nVarint, &aKey[nShort], nKey-nShort);
    assert( pPk->sSeekKey.n>0 );
  }
  pPk->rowChnged = 1;
    rc = sqlite4KVCursorKey(pIdx->pKVCur, &aKey, &nKey);
    if( rc==SQLITE4_OK ){
      nShort = sqlite4VdbeShortKey(aKey, nKey, 
          pIdx->pKeyInfo->nField - pIdx->pKeyInfo->nPK, 0
      );

      nPkKey = sqlite4VarintLen(pPk->iRoot) + nKey - nShort;
      aPkKey = sqlite4DbMallocRaw(db, nPkKey);

      if( aPkKey ){
        putVarint32(aPkKey, pPk->iRoot);
        memcpy(&aPkKey[nPkKey - (nKey-nShort)], &aKey[nShort], nKey-nShort);
        rc = sqlite4KVCursorSeek(pPk->pKVCur, aPkKey, nPkKey, 0);
        if( rc==SQLITE4_NOTFOUND ){
          rc = SQLITE4_CORRUPT_BKPT;
        }
        pPk->nullRow = 0;
        sqlite4DbFree(db, aPkKey);
      }
    }
  }

  break;
}

/* Opcode: SeekGe P1 P2 P3 P4 *
**
** P1 identifies an open database cursor. The cursor is repositioned so
** that it points to the smallest entry in its index that is greater than
** or equal to the key formed by the array of P4 registers starting at
** register P3.
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
** use the value in register P3 as the key.  If cursor P1 refers 
** to an SQL index, then P3 is the first in an array of P4 registers 
** that are used as an unpacked index key. 
**
** Reposition cursor P1 so that it points to the smallest entry that 
** If there are no records greater than or equal to the key and P2 is 
** not zero, then jump to P2.
** is greater than or equal to the key value. If there are no records 
** greater than or equal to the key and P2 is not zero, then jump to P2.
**
** See also: Found, NotFound, Distinct, SeekLt, SeekGt, SeekLe
*/
/* Opcode: SeekGt P1 P2 P3 P4 *
**
** P1 identifies an open database cursor. The cursor is repositioned so
** that it points to the smallest entry in its index that is greater than
** the key formed by the array of P4 registers starting at
** register P3.
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
** use the value in register P3 as a key. If cursor P1 refers 
** to an SQL index, then P3 is the first in an array of P4 registers 
** that are used as an unpacked index key. 
**
** Reposition cursor P1 so that  it points to the smallest entry that 
** If there are no records greater than the key and P2 is 
** not zero, then jump to P2.
** is greater than the key value. If there are no records greater than 
** the key and P2 is not zero, then jump to P2.
**
** See also: Found, NotFound, Distinct, SeekLt, SeekGe, SeekLe
*/
/* Opcode: SeekLt P1 P2 P3 P4 * 
**
** P1 identifies an open database cursor. The cursor is repositioned so
** that it points to the largest entry in its index that is less than
** the key formed by the array of P4 registers starting at
** register P3.
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
** use the value in register P3 as a key. If cursor P1 refers 
** to an SQL index, then P3 is the first in an array of P4 registers 
** that are used as an unpacked index key. 
**
** Reposition cursor P1 so that  it points to the largest entry that 
** If there are no records less than the key and P2 is 
** not zero, then jump to P2.
** is less than the key value. If there are no records less than 
** the key and P2 is not zero, then jump to P2.
**
** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLe
*/
/* Opcode: SeekLe P1 P2 P3 P4 *
**
** P1 identifies an open database cursor. The cursor is repositioned so
** that it points to the largest entry in its index that is less than or
** equal to the key formed by the array of P4 registers starting at
** register P3.
** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 
** use the value in register P3 as a key. If cursor P1 refers 
** to an SQL index, then P3 is the first in an array of P4 registers 
** that are used as an unpacked index key. 
**
** Reposition cursor P1 so that it points to the largest entry that 
** If there are no records less than or equal to the key and P2 is 
** not zero, then jump to P2.
** is less than or equal to the key value. If there are no records 
** less than or equal to the key and P2 is not zero, then jump to P2.
**
** See also: Found, NotFound, Distinct, SeekGt, SeekGe, SeekLt
*/
case OP_SeekLt:         /* jump, in3 */
case OP_SeekLe:         /* jump, in3 */
case OP_SeekGe:         /* jump, in3 */
case OP_SeekGt: {       /* jump, in3 */
  int op;                         /* Copy of pOp->opcode (the op-code) */
  VdbeCursor *pC;                 /* Cursor P1 */
  int nField;                     /* Number of values to encode into key */
  KVByteArray *aProbe;            /* Buffer containing encoded key */
  KVSize nProbe;                  /* Size of aProbe[] in bytes */
  int dir;                        /* KV search dir (+ve or -ve) */
  const KVByteArray *aKey;        /* Pointer to final cursor key */
  KVSize nKey;                    /* Size of aKey[] in bytes */

  pC = p->apCsr[pOp->p1];
  pC->nullRow = 0;
  pC->sSeekKey.n = 0;
  pC->rowChnged = 1;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p2!=0 );
  assert( pC!=0 );
  assert( pC->pseudoTableReg==0 );
  assert( OP_SeekLe == OP_SeekLt+1 );
  assert( OP_SeekGe == OP_SeekLt+2 );
  assert( OP_SeekGt == OP_SeekLt+3 );

  assert( pC->isOrdered );
  dir = +1;
  op = pOp->opcode;
  if( op==OP_SeekLe || op==OP_SeekLt ) dir = -1;

  /* Encode a database key consisting of the contents of the P4 registers
  ** starting at register P3. Have the vdbecodec module allocate an extra
  ** free byte at the end of the database key (see below).  */
  op = pOp->opcode;
  nField = pOp->p4.i;
  pIn3 = &aMem[pOp->p3];
  if( pC->iRoot!=KVSTORE_ROOT ){
    rc = sqlite4VdbeEncodeKey(
        db, pIn3, nField, nField+(pOp->p5 & OPFLAG_PARTIALKEY),
        pC->iRoot, pC->pKeyInfo, &aProbe, &nProbe, 1
    );
  rc = sqlite4VdbeEncodeKey(
      db, pIn3, nField, nField+(pOp->p5 & OPFLAG_PARTIALKEY),
      pC->iRoot, pC->pKeyInfo, &aProbe, &nProbe, 1
  );

    /*   Opcode    search-dir    increment-key
    **  --------------------------------------
    **   SeekLt    -1            no
    **   SeekLe    -1            yes
    **   SeekGe    +1            no
    **   SeekGt    +1            yes
    */
    if( op==OP_SeekLe || op==OP_SeekGt ) aProbe[nProbe++] = 0xFF;
    if( rc==SQLITE4_OK ){
      rc = sqlite4KVCursorSeek(pC->pKVCur, aProbe, nProbe, dir);
  /*   Opcode    search-dir    increment-key
  **  --------------------------------------
  **   SeekLt    -1            no
  **   SeekLe    -1            yes
  **   SeekGe    +1            no
  **   SeekGt    +1            yes
  */
  dir = +1;
  if( op==OP_SeekLe || op==OP_SeekLt ) dir = -1;
  if( op==OP_SeekLe || op==OP_SeekGt ) aProbe[nProbe++] = 0xFF;
  if( rc==SQLITE4_OK ){
    rc = sqlite4KVCursorSeek(pC->pKVCur, aProbe, nProbe, dir);
    }
  }else{
    Stringify(pIn3, encoding);
    rc = sqlite4KVCursorSeek(
        pC->pKVCur, (const KVByteArray *)pIn3->z, pIn3->n, dir
    );
  }

  if( rc==SQLITE4_OK ){
    if( op==OP_SeekLt ){
      rc = sqlite4KVCursorPrev(pC->pKVCur);
    }else if( op==OP_SeekGt ){
      rc = sqlite4KVCursorNext(pC->pKVCur);
    }
  }

  if( pC->iRoot!=KVSTORE_ROOT ){
    /* Check that the KV cursor currently points to an entry belonging
    ** to index pC->iRoot (and not an entry that is part of some other 
    ** index).  */
    if( rc==SQLITE4_OK || rc==SQLITE4_INEXACT ){
      rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
      if( rc==SQLITE4_OK && memcmp(aKey, aProbe, sqlite4VarintLen(pC->iRoot)) ){
        rc = SQLITE4_NOTFOUND;
      }
    }
  /* Check that the KV cursor currently points to an entry belonging
  ** to index pC->iRoot (and not an entry that is part of some other 
  ** index).  */
  if( rc==SQLITE4_OK || rc==SQLITE4_INEXACT ){
    rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
    if( rc==SQLITE4_OK && memcmp(aKey, aProbe, sqlite4VarintLen(pC->iRoot)) ){
      rc = SQLITE4_NOTFOUND;
    }
  }

    /* Free the key allocated above. If no error has occurred but the cursor 
    ** does not currently point to a valid entry, jump to instruction P2.  */
    sqlite4DbFree(db, aProbe);
  /* Free the key allocated above. If no error has occurred but the cursor 
  ** does not currently point to a valid entry, jump to instruction P2.  */
  sqlite4DbFree(db, aProbe);
  }else if( rc==SQLITE4_INEXACT ){
    rc = SQLITE4_OK;
  }

  if( rc==SQLITE4_NOTFOUND ){
    rc = SQLITE4_OK;
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: Seek P1 P2 * * *
**
** P1 is an open table cursor and P2 is a rowid integer.  Arrange
** for P1 to move so that it points to the rowid given by P2.
*/
case OP_Seek: {    /* in2 */
  VdbeCursor *pC;
  KVCursor *pKVCur;
  KVByteArray *aKey;
  KVSize nKey;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  pC->rowChnged = 1;
  assert( pC!=0 );
  assert( pC->isTable );
  pKVCur = pC->pKVCur;
  rc = sqlite4VdbeEncodeKey(db, aMem+pOp->p2, 1, 1, pC->iRoot, 0,
                            &aKey, &nKey, 0);
  if( rc==SQLITE4_OK ){
    rc = sqlite4KVCursorSeek(pKVCur, aKey, nKey, 0);
    if( rc==SQLITE4_NOTFOUND ) rc = SQLITE4_CORRUPT_BKPT;
  }

  sqlite4_found_count++;
#endif

  alreadyExists = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p4type==P4_INT32 );
  pC = p->apCsr[pOp->p1];
  pC->sSeekKey.n = 0;
  pC->rowChnged = 1;
  assert( pC!=0 );
  pIn3 = &aMem[pOp->p3];
  assert( pC->pKVCur!=0 );
  assert( pC->isTable==0 || pOp->opcode==OP_NotExists );
  if( pOp->p4.i>0 ){
    rc = sqlite4VdbeEncodeKey(
        db, pIn3, pOp->p4.i, pOp->p4.i + (pOp->p5 & OPFLAG_PARTIALKEY),
        pC->iRoot, pC->pKeyInfo, &pProbe, &nProbe, 0
    );
    pFree = pProbe;
  }else{

  KVByteArray const *aKey;        /* Key read from cursor */
  KVSize nKey;                    /* Size of aKey in bytes */

  assert( pOp->p4type==P4_INT32 );

  pProbe = &aMem[pOp->p3];
  pC = p->apCsr[pOp->p1];
  pC->rowChnged = 1;
  pOut = (pOp->p4.i==0 ? 0 : &aMem[pOp->p4.i]);
  assert( pOut==0 || (pOut->flags & MEM_Blob) );

  nShort = sqlite4VdbeShortKey((u8 *)pProbe->z, pProbe->n, 
      pC->pKeyInfo->nField - pC->pKeyInfo->nPK, 0
  );
  assert( nShort<=pProbe->n );

case OP_NewRowid: {           /* out2-prerelease */
  i64 v;                   /* The new rowid */
  VdbeCursor *pC;          /* Cursor of table to get the new rowid */
  const KVByteArray *aKey; /* Key of an existing row */
  KVSize nKey;             /* Size of the existing row key */
  int n;                   /* Number of bytes decoded */
  i64 i3;                  /* Integer value from pIn3 */
  sqlite4_num vNum;        /* Intermediate result */

  v = 0;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );

  /* Some compilers complain about constants of the form 0x7fffffffffffffff.

    rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
    if( rc==SQLITE4_OK ){
      n = sqlite4GetVarint64((u8 *)aKey, nKey, (u64 *)&v);
      if( n==0 ) rc = SQLITE4_CORRUPT_BKPT;
      if( v!=pC->iRoot ) rc = SQLITE4_CORRUPT_BKPT;
    }
    if( rc==SQLITE4_OK ){
      n = sqlite4VdbeDecodeNumericKey(&aKey[n], nKey-n, &vNum);
      if( n==0 || (v = sqlite4_num_to_int64(vNum,0))==LARGEST_INT64 ){
      n = sqlite4VdbeDecodeIntKey(&aKey[n], nKey-n, &v);
      if( n==0 || v==LARGEST_INT64 ){
        assert( 0 );
        rc = SQLITE4_FULL;
      }
    }
  }else{
    break;
  }

  }else{
    i1 = iMax+1;
  }
  pIn1->u.num = sqlite4_num_from_int64(i1);

  break;
}

/* Opcode: Insert P1 P2 P3 P4 P5
**
** Write an entry into the table of cursor P1.  A new entry is
** created if it doesn't already exist or the data for an existing
** entry is overwritten.  The data is the value MEM_Blob stored in register
** number P2. The key is stored in register P3. The key must
** be a MEM_Int.
**
** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is
** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P5 is set,
** then rowid is stored for subsequent return by the
** sqlite4_last_insert_rowid() function (otherwise it is unmodified).
**
** If the OPFLAG_ISUPDATE flag is set, then this opcode is part of an
** UPDATE operation.  Otherwise (if the flag is clear) then this opcode
** is part of an INSERT operation.  The difference is only important to
** the update hook.
**
** Parameter P4 may point to a string containing the table-name, or 
** may be NULL. If it is not NULL, then the update-hook 
** (sqlite4.xUpdateCallback) is invoked following a successful insert.
**
** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
** allocated, then ownership of P2 is transferred to the pseudo-cursor
** and register P2 becomes ephemeral.  If the cursor is changed, the
** value of register P2 will then change.  Make sure this does not
** cause any problems.)
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/
/* Opcode: InsertInt P1 P2 P3 P4 P5
**
** This works exactly like OP_Insert except that the key is the
** integer value P3, not the value of the integer stored in register P3.
*/
case OP_Insert:
case OP_InsertInt: {
  Mem *pData;       /* MEM cell holding data for the record to be inserted */
  Mem *pKey;        /* MEM cell holding key  for the record */
  i64 iKey;         /* The integer ROWID or key for the record to be inserted */
  VdbeCursor *pC;   /* Cursor to table into which insert is written */
  int n;
  KVByteArray aKey[24];

  pData = &aMem[pOp->p2];
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( memIsValid(pData) );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  REGISTER_TRACE(pOp->p2, pData);

  if( pOp->opcode==OP_Insert ){
    pKey = &aMem[pOp->p3];
    assert( pKey->flags & MEM_Int );
    assert( memIsValid(pKey) );
    REGISTER_TRACE(pOp->p3, pKey);
    iKey = sqlite4_num_to_int64(pKey->u.num, 0);
  }else{
    /* assert( pOp->opcode==OP_InsertInt ); */
    iKey = pOp->p3;
  }

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pData->flags & MEM_Null ){
    pData->z = 0;
    pData->n = 0;
  }else{
    assert( pData->flags & (MEM_Blob|MEM_Str) );
  }
  n = sqlite4PutVarint64(aKey, pC->iRoot);
  n += sqlite4VdbeEncodeIntKey(&aKey[n], iKey);
  rc = sqlite4KVStoreReplace(pC->pKVCur->pStore, aKey, n,
                             (const KVByteArray*)pData->z, pData->n);

  break;
}

/* Opcode: Delete P1 P2 * * *
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op.  Hence it is OK to delete
** a record from within an Next loop.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).
**
** P1 must not be pseudo-table. It has to be a real table.
*/
case OP_Delete: {
  VdbeCursor *pC;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->sSeekKey.n==0 );
  pC->rowChnged = 1;
  rc = sqlite4KVCursorDelete(pC->pKVCur);
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}

/* Opcode: ResetCount * * * * *
**

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  rc = sqlite4VdbeCursorMoveto(pC);
  if( rc!=SQLITE4_OK ) break;
  assert( pC!=0 );
  assert( pC->nullRow==0 );
  assert( pC->pseudoTableReg==0 );
  assert( pC->pKVCur!=0 );
  pCrsr = pC->pKVCur;

  if( pOp->opcode==OP_RowKey ){
    rc = sqlite4KVCursorKey(pCrsr, &pData, &nData);
    if( pOp->p5 ){
      nData = sqlite4VdbeShortKey(pData, nData, 1, 0);

  pKey = &aMem[pOp->p2];
  aIncr = &aMem[pOp->p3];
  nTotal = pOp->p4.i;
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->nullRow==0 );
  assert( pC->pseudoTableReg==0 );
  assert( pC->pKVCur!=0 );
  assert( pOp->p4type==P4_INT32 );

  rc = sqlite4KVCursorKey(pC->pKVCur, &pNew, &nNew);
  if( rc==SQLITE4_OK ){
    assert( pKey->flags & (MEM_Blob|MEM_Null) );
    if( pKey->flags & MEM_Blob ){

*/
case OP_Rowid: {                 /* out2-prerelease */
  VdbeCursor *pC;
  i64 v;
  const KVByteArray *aKey;
  KVSize nKey;
  int n;
  sqlite4_num vNum;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  rc = sqlite4VdbeCursorMoveto(pC);
  if( rc!=SQLITE4_OK ) break;
  assert( pC->sSeekKey.n==0 );
  assert( pC!=0 );
  assert( pC->pseudoTableReg==0 );
  if( pC->nullRow ){
    pOut->flags = MEM_Null;
    break;
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  }else if( pC->pVtabCursor ){
    pVtab = pC->pVtabCursor->pVtab;
    pModule = pVtab->pModule;
    assert( pModule->xRowid );
    rc = pModule->xRowid(pC->pVtabCursor, &v);
    importVtabErrMsg(p, pVtab);
#endif /* SQLITE4_OMIT_VIRTUALTABLE */
  }else{
    rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
    if( rc==SQLITE4_OK ){
      n = sqlite4GetVarint64(aKey, nKey, (sqlite4_uint64*)&v);
      n = sqlite4VdbeDecodeNumericKey(&aKey[n], nKey-n, &vNum);
      n = sqlite4VdbeDecodeIntKey(&aKey[n], nKey-n, &v);
      if( n==0 ) rc = SQLITE4_CORRUPT;
      v = sqlite4_num_to_int64(vNum,0);
    }
  }
  pOut->u.num = sqlite4_num_from_int64(v);
  break;
}

/* Opcode: NullRow P1 * * * *
**
** Move the cursor P1 to a null row.  Any OP_Column operations
** that occur while the cursor is on the null row will always
** write a NULL.
*/
case OP_NullRow: {
  VdbeCursor *pC;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  pC->nullRow = 1;
  pC->rowChnged = 1;
  break;
}

/* Opcode: Last P1 P2 * * *
**
** The next use of the Rowid or Column or Next instruction for P1 
** will refer to the last entry in the database table or index.

    pC->nullRow = 1;
    rc = SQLITE4_OK;
  }
  break;
}


/* Opcode: SorterInsert P1 P2 P3
*/
/* Opcode: Insert P1 P2 P3 * P5
/* Opcode: IdxInsert P1 P2 P3 * P5
**
** Register P3 holds the key and register P2 holds the data for an
** index entry.  Write this record into the index specified by the
** cursor P1.
**
** P3 can be either an integer or a blob.  If it is a blob then its value
** is used as-is as the KVStore key.  If P3 is an integer, then the KVStore
** key is constructed using P3 as the INTEGER PRIMARY KEY value.
**
** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is
** incremented (otherwise not).
*/
case OP_SorterInsert:
case OP_Insert: {
case OP_IdxInsert: {
  VdbeCursor *pC;
  Mem *pKey;
  Mem *pData;
  int nKVKey;
  KVByteArray *pKVKey;
  KVByteArray aKey[24];
  

  pC = p->apCsr[pOp->p1];
  pKey = &aMem[pOp->p3];
  pData = pOp->p2 ? &aMem[pOp->p2] : 0;

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pC && pC->pKVCur && pC->pKVCur->pStore );
  assert( pKey->flags & MEM_Blob );
  assert( pData==0 || (pData->flags & MEM_Blob) );

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;

  if( pKey->flags & MEM_Int ){
    nKVKey = sqlite4PutVarint64(aKey, pC->iRoot);
    nKVKey += sqlite4VdbeEncodeIntKey(aKey+nKVKey, sqlite4VdbeIntValue(pKey));
    pKVKey = aKey;
  }else{
    nKVKey = pKey->n;
    pKVKey = pKey->z;
  }


  rc = sqlite4KVStoreReplace(
     pC->pKVCur->pStore,
     (u8 *)pKVKey, nKVKey,
     (u8 *)pKey->z, pKey->n,
     (u8 *)(pData ? pData->z : 0), (pData ? pData->n : 0)
  );
  pC->rowChnged = 1;

  break;
}

/* Opcode: IdxDelete P1 * P3 * *
**
** P1 is a cursor open on a database index. P3 contains a key suitable for

  rc = sqlite4KVCursorSeek(pC->pKVCur, (u8 *)pKey->z, pKey->n, 0);
  if( rc==SQLITE4_OK ){
    rc = sqlite4KVCursorDelete(pC->pKVCur);
  }else if( rc==SQLITE4_NOTFOUND ){
    rc = SQLITE4_OK;
  }
  pC->rowChnged = 1;

  break;
}

/* Opcode: IdxRowkey P1 P2 P3 * *
/* Opcode: IdxRowid P1 P2 * * *
**
** Cursor P1 points to an index entry. Extract the encoded primary key 
** fields from the entry. Then set output register P2 to a blob value
** containing the value P3 as a varint followed by the encoded PK
** Write into register P2 an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
** fields.
**
** See also: Rowkey
** See also: Rowid, MakeRecord.
*/
case OP_IdxRowkey: {              /* out2-prerelease */
case OP_IdxRowid: {              /* out2-prerelease */
  KVByteArray const *aKey;        /* Key data from cursor pIdx */
  KVSize nKey;                    /* Size of aKey[] in bytes */
  int nShort;                     /* Size of aKey[] without PK fields */
  KVByteArray *aPkKey;            /* Pointer to PK buffer */
  KVSize nPkKey;                  /* Size of aPkKey in bytes */
  int iRoot;
  VdbeCursor *pC;

  assert( 0 );
  iRoot = pOp->p3;
  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  pC = p->apCsr[pOp->p1];

  rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
  if( rc!=SQLITE4_OK ) break;

  nShort = sqlite4VdbeShortKey(aKey, nKey, 
      pC->pKeyInfo->nField - pC->pKeyInfo->nPK, 0
  );

  nPkKey = sqlite4VarintLen(iRoot) + nKey - nShort;
  if( nPkKey>db->aLimit[SQLITE4_LIMIT_LENGTH] ){
    goto too_big;
  }

  rc = sqlite4VdbeMemGrow(pOut, nPkKey, 0);
  if( rc!=SQLITE4_OK ) break;
  aPkKey = pOut->z;
  putVarint32(aPkKey, iRoot);
  memcpy(&aPkKey[nPkKey - (nKey-nShort)], &aKey[nShort], nKey-nShort);
  pOut->type = SQLITE4_BLOB;
  pOut->n = nPkKey;
  MemSetTypeFlag(pOut, MEM_Blob);

  pOut->enc = SQLITE4_UTF8;  /* In case the blob is ever cast to text */
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: IdxGE P1 P2 P3
**
** P1 is an open cursor. P3 contains a database key formatted by MakeKey.
** This opcode compares the current key that index P1 points to with

  int p1;             /* First operand */
  int p2;             /* Second parameter (often the jump destination) */
  int p3;             /* The third parameter */
  union {             /* fourth parameter */
    int i;                 /* Integer value if p4type==P4_INT32 */
    void *p;               /* Generic pointer */
    char *z;               /* Pointer to data for string (char array) types */
    sqlite4_num *pNum;     /* Used when p4type is P4_NUM */
    i64 *pI64;             /* Used when p4type is P4_INT64 */
    double *pReal;         /* Used when p4type is P4_REAL */
    FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
    CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
    Mem *pMem;             /* Used when p4type is P4_MEM */
    VTable *pVtab;         /* Used when p4type is P4_VTAB */
    KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
    int *ai;               /* Used when p4type is P4_INTARRAY */
    SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
    Fts5Info *pFtsInfo;    /* Used when p4type is P4_FTS5INDEXINFO */
    int (*xAdvance)(VdbeCursor*);  /* Used with p4type==P4_ADVANCE */
    int (*xAdvance)(VdbeCursor*);
    sqlite4_num *pNum;     /* Used when p4type is P4_NUM */
  } p4;
#ifdef SQLITE4_DEBUG
  char *zComment;          /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;                 /* Number of times this instruction was executed */
  u64 cycles;              /* Total time spent executing this instruction */

  signed char p1;     /* First operand */
  signed char p2;     /* Second parameter (often the jump destination) */
  signed char p3;     /* Third parameter */
};
typedef struct VdbeOpList VdbeOpList;

/*
** Allowed values of VdbeOp.p4type.  All values are less than 1 so that
** Allowed values of VdbeOp.p4type
** they can be used unambiguously in the "length" parameter of various
** interfaces.
*/
#define P4_NOTUSED       0   /* The P4 parameter is not used */
#define P4_NOTUSED    0   /* The P4 parameter is not used */
#define P4_TRANSIENT     0   /* P4 is a pointer to a transient string */
#define P4_DYNAMIC     (-1)  /* Pointer to a string obtained from malloc() */
#define P4_STATIC      (-2)  /* Pointer to a static string */
#define P4_COLLSEQ     (-3)  /* P4 is a pointer to a CollSeq structure */
#define P4_FUNCDEF     (-4)  /* P4 is a pointer to a FuncDef structure */
#define P4_KEYINFO     (-5)  /* P4 is a pointer to a KeyInfo structure */
#define P4_VDBEFUNC    (-6)  /* P4 is a pointer to a VdbeFunc structure */
#define P4_MEM         (-7)  /* P4 is a pointer to a Mem*    structure */
#define P4_VTAB        (-8)  /* P4 is a pointer to an sqlite4_vtab structure */
#define P4_NUM         (-9)  /* P4 is a pointer to an sqlite4_num structure */
#define P4_INT32      (-10)  /* P4 is a 32-bit signed integer */
#define P4_INTARRAY   (-11)  /* P4 is a vector of 32-bit integers */
#define P4_SUBPROGRAM (-12)  /* P4 is a pointer to a SubProgram structure */
#define P4_ADVANCE    (-13)  /* P4 is a pointer to BtreeNext() or BtreePrev() */
#define P4_FTS5INFO   (-14)  /* P4 points to an Fts5Info structure */
#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
#define P4_STATIC   (-2)  /* Pointer to a static string */
#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
#define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite4_vtab structure */
#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite4_mprintf() */
#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
#define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
#define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
#define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
#define P4_FTS5INFO (-20) /* P4 points to an Fts5Info structure */
#define P4_NUM      (-21) /* P4 points to an Fts5Info structure */

/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
*/
#define P4_KEYINFO_HANDOFF  (-124)
#define P4_KEYINFO_STATIC   (-125)
#define P4_KEYINFO_HANDOFF (-16)
#define P4_KEYINFO_STATIC  (-17)

/*
** The Vdbe.aColName array contains 5n Mem structures, where n is the 
** number of columns of data returned by the statement.
*/
#define COLNAME_NAME     0
#define COLNAME_DECLTYPE 1

sqlite4_value *sqlite4VdbeGetValue(Vdbe*, int, u8);
void sqlite4VdbeSetVarmask(Vdbe*, int);
#ifndef SQLITE4_OMIT_TRACE
  char *sqlite4VdbeExpandSql(Vdbe*, const char*);
#endif
sqlite4_value *sqlite4ColumnValue(sqlite4_stmt *pStmt, int iCol);

void sqlite4VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
UnpackedRecord *sqlite4VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);

#ifndef SQLITE4_OMIT_TRIGGER
void sqlite4VdbeLinkSubProgram(Vdbe *, SubProgram *);
#endif


#ifndef NDEBUG
  void sqlite4VdbeComment(Vdbe*, const char*, ...);

/* Opaque type used by code in vdbesort.c */
typedef struct VdbeSorter VdbeSorter;

/* Opaque type used by the explainer */
typedef struct Explain Explain;

/* Opaque type used by vdbecodec.c */
typedef struct RowDecoder RowDecoder;
typedef struct ValueDecoder ValueDecoder;

/*
** A cursor is a pointer into a single database.
** The cursor can seek to an entry with a particular key, or
** loop over all entries.  You can also insert new
** entries or retrieve the key or data from the entry that the cursor
** is currently pointing to.
** 
** Every cursor that the virtual machine has open is represented by an
** instance of the following structure.
*/
struct VdbeCursor {
  sqlite4 *db;          /* The connection that owns this cursor */
  KVCursor *pKVCur;     /* The cursor structure of the storage engine */
  KVCursor *pKVCur;     /* The cursor structure of the backend */
  KVStore *pTmpKV;      /* Separate file holding a temporary table */
  KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
  int iRoot;            /* Root page of the table */
  int pseudoTableReg;   /* Register holding pseudotable content. */
  int nField;           /* Number of fields in the header */
  Bool zeroed;          /* True if zeroed out and ready for reuse */
  Bool atFirst;         /* True if pointing to first entry */
  Bool nullRow;         /* True if pointing to a row with no data */
  Bool isTable;         /* True if a table requiring integer keys */
  Bool isIndex;         /* True if an index containing keys only - no data */
  Bool rowChnged;       /* True if row has changed out from under pDecoder */
  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
  sqlite4_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
  const sqlite4_module *pModule;     /* Module for cursor pVtabCursor */
  i64 seqCount;         /* Sequence counter */
  i64 movetoTarget;     /* Argument to the deferred move-to */
  VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
  Fts5Cursor *pFts;     /* Fts5 cursor object (or NULL) */
  RowDecoder *pDecoder;              /* Decoder for row content */
  sqlite4_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
  const sqlite4_module *pModule;     /* Module for cursor pVtabCursor */
  sqlite4_buffer sSeekKey;           /* Key for deferred seek */
};

/* Methods for the VdbeCursor object */
void sqlite4VdbeFreeCursor(VdbeCursor*);
int sqlite4VdbeSeekEnd(VdbeCursor*, int);
int sqlite4VdbeNext(VdbeCursor*);
int sqlite4VdbePrevious(VdbeCursor*);
  /* Result of last sqlite4-Moveto() done by an OP_NotExists or 
  ** OP_IsUnique opcode on this cursor. */
  int seekResult;
int sqlite4VdbeCursorMoveto(VdbeCursor *);

};

/*
** When a sub-program is executed (OP_Program), a structure of this type
** is allocated to store the current value of the program counter, as
** well as the current memory cell array and various other frame specific
** values stored in the Vdbe struct. When the sub-program is finished, 
** these values are copied back to the Vdbe from the VdbeFrame structure,

#define MEM_Int       0x0004   /* Value is an integer */
#define MEM_Real      0x0008   /* Value is a real number */
#define MEM_Blob      0x0010   /* Value is a BLOB */
#define MEM_RowSet    0x0020   /* Value is a RowSet object */
#define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
#define MEM_Invalid   0x0080   /* Value is undefined */
#define MEM_TypeMask  0x00ff   /* Mask of type bits */


/* Whenever Mem contains a valid string or blob representation, one of
** the following flags must be set to determine the memory management
** policy for Mem.z.  The MEM_Term flag tells us whether or not the
** string is \000 or \u0000 terminated
*/
#define MEM_Term      0x0200   /* String rep is nul terminated */

#define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
#define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
#define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */

/*
** Function prototypes
*/
void sqlite4VdbeFreeCursor(Vdbe *, VdbeCursor*);
void sqliteVdbePopStack(Vdbe*,int);
#if defined(SQLITE4_DEBUG) || defined(VDBE_PROFILE)
void sqlite4VdbePrintOp(FILE*, int, Op*);
#endif
u32 sqlite4VdbeSerialTypeLen(u32);
u32 sqlite4VdbeSerialType(Mem*, int);
u32 sqlite4VdbeSerialPut(unsigned char*, int, Mem*, int);
u32 sqlite4VdbeSerialGet(const unsigned char*, u32, Mem*);
void sqlite4VdbeDeleteAuxData(VdbeFunc*, int);

int sqlite4VdbeDecoderCreate(
int sqlite4VdbeCreateDecoder(
  sqlite4 *db,                /* The database connection */
  const unsigned char *aIn,   /* The input data blob */
  VdbeCursor *pCur,           /* Cursor associated with this decoder */
  int nIn,                    /* Number of bytes in aIn[] */
  KVCursor *pKVCur,           /* Alternative cursor if pCur is NULL */
  int mxCol,                  /* Maximum number of columns in aIn[] */
  RowDecoder **ppOut          /* The newly generated decoder object */
  ValueDecoder **ppOut        /* The newly generated decoder object */
);
int sqlite4VdbeDecoderDestroy(RowDecoder *pDecoder);
int sqlite4VdbeDecoderGetColumn(
  RowDecoder *pDecoder,        /* The decoder for the whole string */
int sqlite4VdbeDestroyDecoder(ValueDecoder *pDecoder);
int sqlite4VdbeDecodeValue(
  ValueDecoder *pDecoder,      /* The decoder for the whole string */
  int iVal,                    /* Index of the value to decode.  First is 0 */
  Mem *pDefault,               /* The default value.  Often NULL */
  Mem *pOut                    /* Write the result here */
);
int sqlite4VdbeEncodeData(
  sqlite4 *db,                /* The database connection */
  Mem *aIn,                   /* Array of values to encode */
  int *aPermute,              /* Permutation (or NULL) */
  int nIn,                    /* Number of entries in aIn[] */
  u8 **pzOut,                 /* The output data record */
  int *pnOut                  /* Bytes of content in pzOut */
);
int sqlite4VdbeEncodeKey(
  sqlite4 *db,                 /* The database connection */
  Mem *aIn,                    /* Values to be encoded */
  int nIn,                     /* Number of entries in aIn[] */
  int nInTotal,                /* Number of values in complete key */
  int iTabno,                  /* The table this key applies to */
  KeyInfo *pKeyInfo,           /* Collating sequence information */
  u8 **pzOut,                  /* Write the resulting key here */
  int *pnOut,                  /* Number of bytes in the key */
  int nExtra                   /* Append extra bytes on end of key */
);
int sqlite4VdbeEncodeIntKey(u8 *aBuf,sqlite4_int64 v);
int sqlite4VdbeDecodeNumericKey(const KVByteArray*, KVSize, sqlite4_num*);
int sqlite4VdbeDecodeIntKey(const KVByteArray*, KVSize, sqlite4_int64*);
int sqlite4VdbeShortKey(const u8 *, int, int, int *);
int sqlite4MemCompare(Mem*, Mem*, const CollSeq*,int*);
int sqlite4VdbeExec(Vdbe*);
int sqlite4VdbeList(Vdbe*);
int sqlite4VdbeHalt(Vdbe*);
int sqlite4VdbeChangeEncoding(Mem *, int);
int sqlite4VdbeMemTooBig(Mem*);

const char *sqlite4OpcodeName(int);
int sqlite4VdbeMemGrow(Mem *pMem, int n, int preserve);
int sqlite4VdbeCloseStatement(Vdbe *, int);
void sqlite4VdbeFrameDelete(VdbeFrame*);
int sqlite4VdbeFrameRestore(VdbeFrame *);
void sqlite4VdbeMemStoreType(Mem *pMem);
int sqlite4VdbeTransferError(Vdbe *p);
int sqlite4VdbeSeekEnd(VdbeCursor*, int);
int sqlite4VdbeNext(VdbeCursor*);
int sqlite4VdbePrevious(VdbeCursor*);

int sqlite4VdbeRollback(sqlite4 *db, int iLevel);
int sqlite4VdbeCommit(sqlite4 *db, int iLevel);

#ifdef SQLITE4_DEBUG
void sqlite4VdbeMemAboutToChange(Vdbe*,Mem*);
#endif

  return (int)sqlite4VdbeIntValue((Mem*)pVal);
}
sqlite4_int64 sqlite4_value_int64(sqlite4_value *pVal){
  return sqlite4VdbeIntValue((Mem*)pVal);
}
const char *sqlite4_value_text(sqlite4_value *pVal, int *pnByte){
  const char *zRet = (const char *)sqlite4ValueText(pVal, SQLITE4_UTF8);
  if( pnByte ) *pnByte = (zRet ? ((Mem *)pVal)->n : 0);
  if( pnByte ) *pnByte = ((Mem *)pVal)->n;
  return zRet;
}
#ifndef SQLITE4_OMIT_UTF16
const void *sqlite4_value_text16(sqlite4_value* pVal, int *pnByte){
  const void *pRet = sqlite4ValueText(pVal, SQLITE4_UTF16NATIVE);
  if( pnByte ) *pnByte = (pRet ? ((Mem *)pVal)->n : 0);
  if( pnByte ) *pnByte = ((Mem *)pVal)->n;
  return pRet;
}
const void *sqlite4_value_text16be(sqlite4_value *pVal, int *pnByte){
  const void *pRet = sqlite4ValueText(pVal, SQLITE4_UTF16BE);
  if( pnByte ) *pnByte = (pRet ? ((Mem *)pVal)->n : 0);
  if( pnByte ) *pnByte = ((Mem *)pVal)->n;
  return pRet;
}
const void *sqlite4_value_text16le(sqlite4_value *pVal, int *pnByte){
  const void *pRet = sqlite4ValueText(pVal, SQLITE4_UTF16LE);
  if( pnByte ) *pnByte = (pRet ? ((Mem *)pVal)->n : 0);
  if( pnByte ) *pnByte = ((Mem *)pVal)->n;
  return pRet;
}
#endif /* SQLITE4_OMIT_UTF16 */
int sqlite4_value_type(sqlite4_value* pVal){
  return pVal->type;
}

/*
** Delete a P4 value if necessary.
*/
static void freeP4(sqlite4 *db, int p4type, void *p4){
  if( p4 ){
    assert( db );
    switch( p4type ){
      case P4_REAL:
      case P4_NUM:
      case P4_INT64:
      case P4_DYNAMIC:
      case P4_KEYINFO:
      case P4_INTARRAY:
      case P4_KEYINFO_HANDOFF: {
        sqlite4DbFree(db, p4);
        break;
      }
      case P4_MPRINTF: {
        if( db->pnBytesFreed==0 ) sqlite4_free(db->pEnv, p4);
        break;
      }
      case P4_VDBEFUNC: {
        VdbeFunc *pVdbeFunc = (VdbeFunc *)p4;
        freeEphemeralFunction(db, pVdbeFunc->pFunc);
        if( db->pnBytesFreed==0 ) sqlite4VdbeDeleteAuxData(pVdbeFunc, 0);
        sqlite4DbFree(db, pVdbeFunc);
        break;

     || defined(VDBE_PROFILE) || defined(SQLITE4_DEBUG)
/*
** Compute a string that describes the P4 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
static char *displayP4(Op *pOp, char *zTemp, int nTemp){
  char *zP4 = zTemp;
  assert( nTemp>=30 );
  assert( nTemp>=20 );
  switch( pOp->p4type ){
    case P4_KEYINFO_STATIC:
    case P4_KEYINFO: {
      int i, j;
      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
      i = sqlite4_snprintf(zTemp, nTemp,
      i = sqlite4_snprintf(zTemp, nTemp, "keyinfo(%d", pKeyInfo->nField);
                 "keyinfo(%d,%d,%d", pKeyInfo->nField, pKeyInfo->nPK,
                 pKeyInfo->nData);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        if( pColl ){
          int n = sqlite4Strlen30(pColl->zName);
          if( i+n>nTemp-6 ){
            memcpy(&zTemp[i],",...",4);
            break;

      sqlite4_snprintf(zTemp, nTemp, "collseq(%.20s)", pColl->zName);
      break;
    }
    case P4_FUNCDEF: {
      FuncDef *pDef = pOp->p4.pFunc;
      sqlite4_snprintf(zTemp, nTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
    case P4_INT64: {
      sqlite4_snprintf(zTemp, nTemp, "%lld", *pOp->p4.pI64);
      break;
    }
    case P4_INT32: {
      sqlite4_snprintf(zTemp, nTemp, "%d", pOp->p4.i);
      break;
    }
    case P4_NUM: {
      sqlite4_num_to_text(*pOp->p4.pNum, zTemp, 0); 
    case P4_REAL: {
      sqlite4_snprintf(zTemp, nTemp, "%.16g", *pOp->p4.pReal);
      break;
    }
    case P4_MEM: {
      Mem *pMem = pOp->p4.pMem;
      if( pMem->flags & MEM_Str ){
        zP4 = pMem->z;
      }else if( pMem->flags & (MEM_Int|MEM_Real) ){

    case P4_VTAB: {
      sqlite4_vtab *pVtab = pOp->p4.pVtab->pVtab;
      sqlite4_snprintf(zTemp, nTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
      break;
    }
#endif
    case P4_INTARRAY: {
      int i, j, n, cSep = '(';
      i = sqlite4_snprintf(zTemp, nTemp, "intarray");
      sqlite4_snprintf(zTemp, nTemp, "intarray");
      n = pOp->opcode==OP_Permutation ? pOp->p1 : 0;
      for(j=0; j<n; j++){
        i += sqlite4_snprintf(zTemp+i, nTemp-i,"%c%d",cSep, pOp->p4.ai[j]);
        cSep = ',';
      }
      sqlite4_snprintf(zTemp+i, nTemp-i, ")");
      break;
    }
    case P4_SUBPROGRAM: {
      sqlite4_snprintf(zTemp, nTemp, "program");
      break;
    }
    case P4_ADVANCE: {
      zTemp[0] = 0;
      break;
    }
    default: {
      if( pOp->opcode==OP_Blob ){
        int n = pOp->p1*2+2;
        if( n>nTemp-2 ) n = nTemp-2;
        zTemp[0] = 'x';
        zTemp[1] = '\'';
        sqlite4BlobToHex((n-2)/2,pOp->p4.z,zTemp+2);
        zTemp[n] = '\'';
        zTemp[n+1] = 0;
      }else{
        zP4 = pOp->p4.z;
        if( zP4==0 ){
          zP4 = zTemp;
          zTemp[0] = 0;
      zP4 = pOp->p4.z;
      if( zP4==0 ){
        zP4 = zTemp;
        zTemp[0] = 0;
        }
      }
    }
  }
  assert( zP4!=0 );
  return zP4;
}
#endif

#if defined(VDBE_PROFILE) || defined(SQLITE4_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqlite4VdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP4;
  char zPtr[150];
  char zPtr[50];
  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-4s %.2X %s\n";
  if( pOut==0 ) pOut = stdout;
  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
  fprintf(pOut, zFormat1, pc, 
      sqlite4OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
#ifdef SQLITE4_DEBUG
      pOp->zComment ? pOp->zComment : ""

** allocated by the OP_Program opcode in sqlite4VdbeExec().
*/
void sqlite4VdbeFrameDelete(VdbeFrame *p){
  int i;
  Mem *aMem = VdbeFrameMem(p);
  VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];
  for(i=0; i<p->nChildCsr; i++){
    sqlite4VdbeFreeCursor(apCsr[i]);
    sqlite4VdbeFreeCursor(p->v, apCsr[i]);
  }
  releaseMemArray(aMem, p->nChildMem);
  sqlite4DbFree(p->v->db, p);
}

#ifndef SQLITE4_OMIT_EXPLAIN
/*

    pMem++;

    pMem->flags = MEM_Int;
    pMem->u.num = sqlite4_num_from_int64(pOp->p3);         /* P3 */
    pMem->type = SQLITE4_INTEGER;
    pMem++;

    if( sqlite4VdbeMemGrow(pMem, 150, 0) ){                /* P4 */
    if( sqlite4VdbeMemGrow(pMem, 32, 0) ){                 /* P4 */
      assert( p->db->mallocFailed );
      return SQLITE4_ERROR;
    }
    pMem->flags = MEM_Dyn|MEM_Str|MEM_Term;
    z = displayP4(pOp, pMem->z, 150);
    z = displayP4(pOp, pMem->z, 32);
    if( z!=pMem->z ){
      sqlite4VdbeMemSetStr(pMem, z, -1, SQLITE4_UTF8, 0, 0);
    }else{
      assert( pMem->z!=0 );
      pMem->n = sqlite4Strlen30(pMem->z);
      pMem->enc = SQLITE4_UTF8;
    }

      p->aMem[n].flags = MEM_Invalid;
      p->aMem[n].db = db;
    }
  }
  p->explain = pParse->explain;
  sqlite4VdbeRewind(p);
}

/*
** Close a VDBE cursor and release all the resources that cursor 
** happens to hold.
*/
void sqlite4VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
  if( pCx==0 ){
    return;
  }
  sqlite4Fts5Close(pCx->pFts);
  if( pCx->pKVCur ){
    sqlite4KVCursorClose(pCx->pKVCur);
  }
  if( pCx->pTmpKV ){
    sqlite4KVStoreClose(pCx->pTmpKV);
  }
#ifndef SQLITE4_OMIT_VIRTUALTABLE
  if( pCx->pVtabCursor ){
    sqlite4_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
    const sqlite4_module *pModule = pCx->pModule;
    p->inVtabMethod = 1;
    pModule->xClose(pVtabCursor);
    p->inVtabMethod = 0;
  }
#endif
}

/*
** Copy the values stored in the VdbeFrame structure to its Vdbe. This
** is used, for example, when a trigger sub-program is halted to restore
** control to the main program.
*/
int sqlite4VdbeFrameRestore(VdbeFrame *pFrame){

  p->nFrame = 0;

  if( p->apCsr ){
    int i;
    for(i=0; i<p->nCursor; i++){
      VdbeCursor *pC = p->apCsr[i];
      if( pC ){
        sqlite4VdbeFreeCursor(pC);
        sqlite4VdbeFreeCursor(p, pC);
        p->apCsr[i] = 0;
      }
    }
  }
  if( p->aMem ){
    releaseMemArray(&p->aMem[1], p->nMem);
  }

  return u.r;
}
# define swapMixedEndianFloat(X)  X = floatSwap(X)
#else
# define swapMixedEndianFloat(X)
#endif


/*
** This routine is used to allocate sufficient space for an UnpackedRecord
** structure large enough to be used with sqlite4VdbeRecordUnpack() if
** the first argument is a pointer to KeyInfo structure pKeyInfo.
**
** The space is either allocated using sqlite4DbMallocRaw() or from within
** the unaligned buffer passed via the second and third arguments (presumably
** stack space). If the former, then *ppFree is set to a pointer that should
** be eventually freed by the caller using sqlite4DbFree(). Or, if the 
** allocation comes from the pSpace/szSpace buffer, *ppFree is set to NULL
** before returning.
**
** If an OOM error occurs, NULL is returned.
*/
UnpackedRecord *sqlite4VdbeAllocUnpackedRecord(
  KeyInfo *pKeyInfo,              /* Description of the record */
  char *pSpace,                   /* Unaligned space available */
  int szSpace,                    /* Size of pSpace[] in bytes */
  char **ppFree                   /* OUT: Caller should free this pointer */
){
  UnpackedRecord *p;              /* Unpacked record to return */
  int nOff;                       /* Increment pSpace by nOff to align it */
  int nByte;                      /* Number of bytes required for *p */

  /* We want to shift the pointer pSpace up such that it is 8-byte aligned.
  ** Thus, we need to calculate a value, nOff, between 0 and 7, to shift 
  ** it by.  If pSpace is already 8-byte aligned, nOff should be zero.
  */
  nOff = (8 - (SQLITE4_PTR_TO_INT(pSpace) & 7)) & 7;
  nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
  if( nByte>szSpace+nOff ){
    p = (UnpackedRecord *)sqlite4DbMallocRaw(pKeyInfo->db, nByte);
    *ppFree = (char *)p;
    if( !p ) return 0;
  }else{
    p = (UnpackedRecord*)&pSpace[nOff];
    *ppFree = 0;
  }

  p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
  p->pKeyInfo = pKeyInfo;
  p->nField = pKeyInfo->nField + 1;
  return p;
}


/*
** This routine sets the value to be returned by subsequent calls to
** sqlite4_changes() on the database handle 'db'. 
*/
void sqlite4VdbeSetChanges(sqlite4 *db, int nChange){
  assert( sqlite4_mutex_held(db->mutex) );

** insertion and reading from the key/value storage engine.
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** The decoder object.
**
** An instance of this object is used to extract individual columns (numbers,
** strings, blobs, or NULLs) from a row of a table or index.  Usually the
** content is extract from the value side of the key/value pair, though
** sometimes information might be taken from the key as well.
**
** When the VDBE needs to extract multiple columns from the same row, it will
** try to reuse a single decoder object.  The decoder, therefore, should attempt
** to cache any intermediate results that might be useful on later invocations.
*/
struct RowDecoder {
struct ValueDecoder {
  sqlite4 *db;                /* The database connection */
  VdbeCursor *pCur;           /* The cursor for being decoded */
  KVCursor *pKVCur;           /* Alternative KVCursor if pCur is NULL */
  const KVByteArray *a;       /* Content to be decoded */
  const u8 *a;                /* Content to be decoded */
  const KVByteArray *aKey;    /* Key content */
  KVSize n;                   /* Bytes of content in a[] */
  int n;                      /* Bytes of content in a[] */
  KVSize nKey;                /* Bytes of key content */
  int mxCol;                  /* Maximum number of columns */
};

/*
** Create an object that can be used to decode fields of the data encoding.
**
** The aIn[] value must remain stable for the life of the decoder.
*/
int sqlite4VdbeDecoderCreate(
int sqlite4VdbeCreateDecoder(
  sqlite4 *db,                /* The database connection */
  VdbeCursor *pCur,           /* The cursor associated with this decoder */
  KVCursor *pKVCur,           /* Alternative KVCursor */
  int mxCol,                  /* Maximum number of columns to ever decode */
  RowDecoder **ppOut          /* Return the answer here */
  const unsigned char *aIn,   /* The input data blob */
  int nIn,                    /* Number of bytes in aIn[] */
  int mxCol,                  /* Maximum number of columns in aIn[] */
  ValueDecoder **ppOut        /* The newly generated decoder object */
){
  RowDecoder *p;
  ValueDecoder *p;

  assert( pCur==0 || pKVCur==0 );
  assert( pCur!=0 || pKVCur!=0 );
  p = sqlite4DbMallocZero(db, sizeof(*p));
  *ppOut = p;
  if( p==0 ) return SQLITE4_NOMEM;
  p->db = db;
  p->pCur = pCur;
  p->pKVCur = pKVCur;
  p->a = aIn;
  p->n = nIn;
  p->mxCol = mxCol;
  return SQLITE4_OK;
}

/*
** Destroy a decoder object previously created
** using sqlite4VdbeCreateDecoder().
*/
int sqlite4VdbeDecoderDestroy(RowDecoder *p){
int sqlite4VdbeDestroyDecoder(ValueDecoder *p){
  if( p ){
    sqlite4DbFree(p->db, p);
  }
  return SQLITE4_OK;
}

/*
** Make sure the p->a and p->n fields are valid and current.
*/
static int decoderFetchData(RowDecoder *p){
  VdbeCursor *pCur = p->pCur;
  int rc;
  if( pCur==0 ){
    rc = sqlite4KVCursorData(p->pKVCur, 0, -1, &p->a, &p->n);
    return rc;
  }
  if( pCur->rowChnged ){
    p->a = 0;
    p->aKey = 0;
    pCur->rowChnged = 0;
  }
  if( p->a ) return SQLITE4_OK;
  rc = sqlite4VdbeCursorMoveto(pCur);
  if( rc ) return rc;
  if( pCur->nullRow ){
    p->a = 0;
    p->n = 0;
    return SQLITE4_OK;
  }
  assert( pCur->pKVCur!=0 );
  return sqlite4KVCursorData(pCur->pKVCur, 0, -1, &p->a, &p->n);
}

** Decode a single value from a data string.
/*
** Make sure the p->aKey and p->nKey fields are valid and current.
*/
static int decoderFetchKey(RowDecoder *p){
  VdbeCursor *pCur = p->pCur;
  int rc;
  if( pCur==0 ){
    rc = sqlite4KVCursorKey(p->pKVCur, &p->aKey, &p->nKey);
    return rc;
  }
  assert( p->a!=0 );
  if( p->aKey ) return SQLITE4_OK;
  assert( pCur->pKVCur!=0 );
  return sqlite4KVCursorKey(pCur->pKVCur, &p->aKey, &p->nKey);
}

/*
** Decode a blob from a key.  The blob-key is in a[0] through a[n-1].
** xorMask is either 0x00 for ascending order or 0xff for descending.
** Store the blob in pOut.
*/
static int decoderMemSetFromBlob(
  const KVByteArray *a, KVSize n, /* The blob as a key */
  unsigned int xorMask,           /* 0x00 (ascending) or 0xff (descending) */
  Mem *pOut                       /* Write the blob here */
){
  int rc;
  unsigned int m = 0;
  int i, j, k;

  sqlite4VdbeMemSetStr(pOut, "", 0, 0, 0, 0);
  rc = sqlite4VdbeMemGrow(pOut, n, 0);
  if( rc==SQLITE4_OK ){
    i = 0;
    j = 0;
    k = 0;
    while( i<n ){
      m = (m<<7) | ((a[i++] ^ xorMask)&0x7f);
      j += 7;
      if( j>=8 ){
        pOut->z[k++] = (m>>(j-8))&0xff;
        j -= 8;
      }
    }
    if( j>0 ){
      pOut->z[k] = m<<(7-j);
    }
    pOut->n = k;
  }
  return rc;
}

/*
** Decode a numeric key encoding.  Return the number of bytes in the
** encoding on success.  On an error, return 0.
*/
int sqlite4VdbeDecodeNumericKey(
  const KVByteArray *aKey,       /* Input encoding */
  KVSize nKey,                   /* Number of bytes in aKey[] */
  sqlite4_num *pVal              /* Write the result here */
){
  unsigned int i, y;
  unsigned int xorMask = 0;
  short e;
  sqlite4_uint64 m;
  sqlite4_int64 eBig;
  KVByteArray aInvertedKey[4];

  pVal->approx = 0;
  pVal->sign = 0;
  if( nKey<1 ) return 0;
  switch( aKey[0] ){
    case 0x06:   /* NaN ascending */
    case 0xf9:   /* NaN descending */
      pVal->m = 0;
      pVal->e = 1000;
      return 1;

    case 0x07:   /* -inf ascending */
    case 0xf8:   /* -inf descending */
      pVal->m = 1;
      pVal->sign = 1;
      pVal->e = 1000;
      return 1;

    case 0x15:   /* zero ascending */
    case 0xea:   /* zero descending */
      pVal->m = 0;
      pVal->e = 0;
      return 1;

    case 0x23:   /* +inf ascending */
    case 0xdc:   /* +inf descending */
      pVal->m = 1;
      pVal->e = 1000;
      return 1;

    case 0x09:
    case 0x0a:
    case 0x0b:
    case 0x0c:
    case 0x0d:
    case 0x0e:
    case 0x0f:
    case 0x10:
    case 0x11:
    case 0x12:
    case 0x13:   /* -medium ascending */
      pVal->sign = 1;
      xorMask = 0xff;
      e = 0x13 - aKey[0];
      i = 1;
      break;

    case 0xf6:
    case 0xf5:
    case 0xf4:
    case 0xf3:
    case 0xf2:
    case 0xf1:
    case 0xf0:
    case 0xef:
    case 0xee:
    case 0xed:
    case 0xec:   /* -medium descending */
      pVal->sign = 1;
      e = aKey[0] - 0xec;
      i = 1;
      break;

    case 0x17:
    case 0x18:
    case 0x19:
    case 0x1a:
    case 0x1b:
    case 0x1c:
    case 0x1d:
    case 0x1e:
    case 0x1f:
    case 0x20:
    case 0x21:   /* +medium ascending */
      e = aKey[0] - 0x17;
      i = 1;
      break;

    case 0xe8:
    case 0xe7:
    case 0xe6:
    case 0xe5:
    case 0xe4:
    case 0xe3:
    case 0xe2:
    case 0xe1:
    case 0xe0:
    case 0xdf:
    case 0xde:   /* +medium descending */
      e = 0xe8 - aKey[0];
      xorMask = 0xff;
      i = 1;
      break;

    case 0x14:   /* -small ascending */
    case 0xe9:   /* +small descending */
      i = 1 + sqlite4GetVarint64(aKey+1, 2, &eBig);
      e = (short)-eBig;
      xorMask = 0xff;
      break;

    case 0x16:   /* +small ascending */
    case 0xeb:   /* -small descending */
      aInvertedKey[0] = aKey[1] ^ 0xff;
      aInvertedKey[1] = aKey[2] ^ 0xff;
      i = 1 + sqlite4GetVarint64(aInvertedKey, 2, &eBig);
      e = (short)-eBig;
      break;

    case 0x08:   /* -large ascending */
    case 0xdd:   /* +large descending */
      aInvertedKey[0] = aKey[1] ^ 0xff;
      aInvertedKey[1] = aKey[2] ^ 0xff;
      i = 1 + sqlite4GetVarint64(aInvertedKey, 2, &eBig);
      e = (short)eBig;
      xorMask = 0xff;
      break;

    case 0x22:   /* +large ascending */
    case 0xf7:   /* -large descending */
      i = 1 + sqlite4GetVarint64(aKey+1, 2, &eBig);
      e = (short)eBig;
      break;

    default:
      return 0;
  }
  m = 0;
  do{
    y = aKey[i++] ^ xorMask;
    m = m*100 + y/2;
    e--;
  }while( y & 1 );
  if( m==0 ) return 0;

  pVal->m = m;
  pVal->e = 2*e;
  return i;
}

/*
** This is a private method for the RowDecoder object.
**
** Attempt to extract a single column value from the key of the current
** key/value pair.  If beginning of the value is iOfst bytes from the beginning
** of the key.  If affReal is true, then force numeric values to be floating
** point.  Write the result in pOut.  Or return non-zero if there is an
** error.
*/
static int decoderFromKey(
  RowDecoder *p,           /* The current key/value pair */
  int affReal,             /* True to coerce numbers to floating point */
  sqlite4_int64 iOfst,     /* Offset of value in the key */
  Mem *pOut                /* Write the results here */
){
  int rc;
  KVSize i;
  KVSize n;
  const KVByteArray *a;
  char *z;

  if( iOfst<0 ){
    return SQLITE4_CORRUPT_BKPT;
  }
  rc = decoderFetchKey(p);
  if( rc ) return rc;
  if( iOfst>=p->nKey ){
    return SQLITE4_CORRUPT_BKPT;
  }
  a = p->aKey;
  n = p->nKey;
  switch( a[iOfst++] ){
    case 0x05: case 0xFA:       /* NULL */
    case 0x06: case 0xF9: {     /* NaN */
      sqlite4VdbeMemSetNull(pOut);
      break;
    }

    case 0x24: {                /* Text (ascending index) */
      for(i=iOfst; i<n && a[i]!=0; i++){}
      rc = sqlite4VdbeMemSetStr(pOut, &a[iOfst], i-iOfst,
                                SQLITE4_UTF8, SQLITE4_TRANSIENT, 0);
      break;
    }
    case 0xDB: {                /* Text (descending index) */
      for(i=iOfst; i<n && a[i]!=0xFF; i++){}
      rc = sqlite4VdbeMemSetStr(pOut, &a[iOfst+1], n = i - iOfst,
                                SQLITE4_UTF8, SQLITE4_TRANSIENT, 0);
      if( rc==SQLITE4_OK ){
        z = pOut->z;
        for(i=n-1; i>=0; i--) *(z++) ^= 0xFF;
      }
      break;
    }

    case 0x25: {                /* Blob (ascending index) */
      for(i=iOfst; i<n && a[i]!=0; i++){}
      rc = decoderMemSetFromBlob(&a[iOfst], i-iOfst, 0x00, pOut);
      break;
    }
    case 0xDA: {                /* Blob (descending index) */
      for(i=iOfst; i<n && a[i]!=0xFF; i++){}
      rc = decoderMemSetFromBlob(&a[iOfst], i-iOfst, 0xFF, pOut);
      break;
    }

    case 0x26: {                /* Blob-final (ascending) */
      rc = sqlite4VdbeMemSetStr(pOut, &a[iOfst], n-iOfst, 0,
                                SQLITE4_TRANSIENT, 0);
      break;
    }
    case 0xD9: {                /* Blob-final (descending) */
      rc = sqlite4VdbeMemSetStr(pOut, &a[iOfst], n-iOfst,
                                SQLITE4_UTF8, SQLITE4_TRANSIENT, 0);
      if( rc==SQLITE4_OK ){
        z = pOut->z;
        for(i=n-iOfst; i>0; i--) *(z++) ^= 0xFF;
      }
      break;
    }
    default: {
      sqlite4_num v;
      i = sqlite4VdbeDecodeNumericKey(a+iOfst-1, n-iOfst+1, &v);
      if( i==0 ){
        rc = SQLITE4_CORRUPT_BKPT;
      }else{
        sqlite4VdbeMemSetNum(pOut, v, affReal ? MEM_Real : MEM_Int);
        rc = SQLITE4_OK;
      }
      break;
    }
  };
  return rc;
}

/*
** Decode a single column from a key/value pair taken from the storage
** engine.  The key/value pair to be decoded is the one that the VdbeCursor
** or KVCursor is currently pointing to.
**
** iVal is the column index of the value.  0 is the first column of the
** value.  If N is the number of columns in the value and iVal>=N then
** the result is pDefault.  Write the result into pOut.  Return SQLITE4_OK
** on success or an appropriate error code on failure.
**
** The key is referenced only if the iVal-th column in the value is either
** the 22 or 23 header code which indicates that the value is stored in the
** key instead.
*/
int sqlite4VdbeDecoderGetColumn(
  RowDecoder *p,             /* The decoder for the whole string */
int sqlite4VdbeDecodeValue(
  ValueDecoder *p,             /* The decoder for the whole string */
  int iVal,                    /* Index of the value to decode.  First is 0 */
  Mem *pDefault,               /* The default value.  Often NULL */
  Mem *pOut                    /* Write the result here */
){
  u32 size;                    /* Size of a field */
  sqlite4_uint64 ofst;         /* Offset to the payload */
  sqlite4_uint64 type;         /* Datatype */
  sqlite4_uint64 subtype;      /* Subtype for a typed blob */
  int cclass;                  /* class of content */
  int n;                       /* Offset into the header */
  int i;                       /* Loop counter */
  int sz;                      /* Size of a varint */
  int endHdr;                  /* First byte past header */
  int rc;                      /* Return code */

  sqlite4VdbeMemSetNull(pOut);
  assert( iVal<=p->mxCol );
  rc = decoderFetchData(p);
  if( rc ) return rc;
  if( p->a==0 ) return SQLITE4_OK;
  n = sqlite4GetVarint64(p->a, p->n, &ofst);
  if( n==0 ) return SQLITE4_CORRUPT;
  ofst += n;
  endHdr = ofst;
  if( endHdr>p->n ) return SQLITE4_CORRUPT;
  for(i=0; i<=iVal && n<endHdr; i++){
    sz = sqlite4GetVarint64(p->a+n, p->n-n, &type);
    if( sz==0 ) return SQLITE4_CORRUPT;
    n += sz;
    if( type>=22 ){  /* STRING, BLOB, KEY, and TYPED */
      cclass = (type-22)%4;
    if( type>=22 ){
      cclass = (type-22)%3;
      if( cclass==2 ){
        size = 0;  /* KEY */
      }else{
        size = (type-22)/4;
        if( cclass==3 ){  /* The TYPED header code */
          sz = sqlite4GetVarint64(p->a+n, p->n-n, &subtype);
          if( sz==0 ) return SQLITE4_CORRUPT;
          n += sz;
        }
         sz = sqlite4GetVarint64(p->a+n, p->n-n, &subtype);
         if( sz==0 ) return SQLITE4_CORRUPT;
         n += sz;
      }
      }
    }else if( type<=2 ){  /* NULL, ZERO, and ONE */
      size = (type-22)/3;
    }else if( type<=2 ){
      size = 0;
    }else if( type<=10 ){ /* INT */
    }else if( type<=10 ){
      size = type - 2;
    }else{
      assert( type>=11 && type<=21 );  /* NUM */
      size = type - 9;
    }
    if( i<iVal ){
      ofst += size;
    }else if( type==0 ){
      /* no-op */
    }else if( type<=2 ){