);
    if( pIdxKey==0 ) return SQLITE_NOMEM;
    sqlite3VdbeRecordUnpack(pCur->pKeyInfo, nKey, pKey, pIdxKey);
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
  if( pKey ){
    sqlite3DbFree(pCur->pKeyInfo->db, pFree);
  }
  return rc;
}

/*
** Restore the cursor to the position it was in (or as close to as possible)

    );
    if( pIdxKey==0 ) return SQLITE_NOMEM;
    sqlite3VdbeRecordUnpack(pCur->pKeyInfo, nKey, pKey, pIdxKey);
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
  if( pFree ){
    sqlite3DbFree(pCur->pKeyInfo->db, pFree);
  }
  return rc;
}

/*
** Restore the cursor to the position it was in (or as close to as possible)

  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 - (SQLITE_PTR_TO_INT(pSpace) & 7)) & 7;
  pSpace += nOff;
  szSpace -= nOff;

  nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
  if( nByte>szSpace ){
    p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
    *ppFree = (char *)p;

  }else{
    p = (UnpackedRecord*)pSpace;
    *ppFree = 0;
  }
  



  return p;
}

/*
** Given the nKey-byte encoding of a record in pKey[], populate the 
** UnpackedRecord structure indicated by the fourth argument with the
** contents of the decoded record.
................................................................................
  UnpackedRecord *p      /* Populate this structure before returning. */
){
  const unsigned char *aKey = (const unsigned char *)pKey;
  int d; 
  u32 idx;                        /* Offset in aKey[] to read from */
  u16 u;                          /* Unsigned loop counter */
  u32 szHdr;
  Mem *pMem;

  p->flags = 0;
  p->pKeyInfo = pKeyInfo;
  p->nField = pKeyInfo->nField + 1;
  p->aMem = pMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
  idx = getVarint32(aKey, szHdr);
  d = szHdr;
  u = 0;
  while( idx<szHdr && u<p->nField && d<=nKey ){
    u32 serial_type;

  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 - (SQLITE_PTR_TO_INT(pSpace) & 7)) & 7;



  nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
  if( nByte>szSpace+nOff ){
    p = (UnpackedRecord *)sqlite3DbMallocRaw(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;
}

/*
** Given the nKey-byte encoding of a record in pKey[], populate the 
** UnpackedRecord structure indicated by the fourth argument with the
** contents of the decoded record.
................................................................................
  UnpackedRecord *p      /* Populate this structure before returning. */
){
  const unsigned char *aKey = (const unsigned char *)pKey;
  int d; 
  u32 idx;                        /* Offset in aKey[] to read from */
  u16 u;                          /* Unsigned loop counter */
  u32 szHdr;
  Mem *pMem = p->aMem;

  p->flags = 0;



  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
  idx = getVarint32(aKey, szHdr);
  d = szHdr;
  u = 0;
  while( idx<szHdr && u<p->nField && d<=nKey ){
    u32 serial_type;

  int *pRes                       /* OUT: Result of comparison */
){
  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
  VdbeSorter *pSorter = pCsr->pSorter;
  UnpackedRecord *r2 = pSorter->pUnpacked;
  int i;

  if( r2==0 ){
    char *pFree;
    r2 = sqlite3VdbeAllocUnpackedRecord(pKeyInfo, 0, 0, &pFree);
    if( r2==0 ) return SQLITE_NOMEM;
    assert( pFree==(char *)r2 );
    pSorter->pUnpacked = r2;
  }

  if( pKey2 ){
    sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, r2);
  }

  if( bOmitRowid ){


    for(i=0; i<r2->nField-1; i++){
      if( r2->aMem[i].flags & MEM_Null ){
        *pRes = -1;
        return SQLITE_OK;
      }
    }
    r2->flags |= UNPACKED_PREFIX_MATCH;
    r2->nField--;
    assert( r2->nField>0 );
  }

  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
  return SQLITE_OK;
}

/*
................................................................................
/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
  int pgsz;                       /* Page size of main database */
  int mxCache;                    /* Cache size */
  VdbeSorter *pSorter;            /* The new sorter */


  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  pCsr->pSorter = pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
  if( pSorter==0 ){
    return SQLITE_NOMEM;
  }





  if( !sqlite3TempInMemory(db) ){
    pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
    pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
    mxCache = db->aDb[0].pSchema->cache_size;
    if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
    pSorter->mxPmaSize = mxCache * pgsz;

  int *pRes                       /* OUT: Result of comparison */
){
  KeyInfo *pKeyInfo = pCsr->pKeyInfo;
  VdbeSorter *pSorter = pCsr->pSorter;
  UnpackedRecord *r2 = pSorter->pUnpacked;
  int i;









  if( pKey2 ){
    sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, r2);
  }

  if( bOmitRowid ){
    r2->nField = pKeyInfo->nField;
    assert( r2->nField>0 );
    for(i=0; i<r2->nField; i++){
      if( r2->aMem[i].flags & MEM_Null ){
        *pRes = -1;
        return SQLITE_OK;
      }
    }
    r2->flags |= UNPACKED_PREFIX_MATCH;


  }

  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
  return SQLITE_OK;
}

/*
................................................................................
/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
  int pgsz;                       /* Page size of main database */
  int mxCache;                    /* Cache size */
  VdbeSorter *pSorter;            /* The new sorter */
  char *d;                        /* Dummy */

  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  pCsr->pSorter = pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
  if( pSorter==0 ){
    return SQLITE_NOMEM;
  }
  
  pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pCsr->pKeyInfo, 0, 0, &d);
  if( pSorter->pUnpacked==0 ) return SQLITE_NOMEM;
  assert( pSorter->pUnpacked==(UnpackedRecord *)d );

  if( !sqlite3TempInMemory(db) ){
    pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
    pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
    mxCache = db->aDb[0].pSchema->cache_size;
    if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
    pSorter->mxPmaSize = mxCache * pgsz;