SQLite

    goto jump_to_p2;
  }else if( eqOnly ){
    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
    pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */
  }
  break;
}




































  

/* Opcode: Found P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If
** P4>0 then register P3 is the first of P4 registers that form an unpacked

    rc = sqlite3BtreeDelete(pCrsr, BTREE_AUXDELETE);
  }
  assert( pC->deferredMoveto==0 );
  pC->cacheStatus = CACHE_STALE;
  break;
}

/* Opcode: Seek P1 * P3 P4 *
** Synopsis:  Move P3 to P1.rowid
**
** P1 is an open index cursor and P3 is a cursor on the corresponding
** table.  This opcode does a deferred seek of the P3 table cursor
** to the row that corresponds to the current row of P1.
**
** This is a deferred seek.  Nothing actually happens until
** the cursor is used to read a record.  That way, if no reads
** occur, no unnecessary I/O happens.
**
** P4 may be an array of integers (type P4_INTARRAY) containing
** one entry for each column in the P3 table.  If array entry a[i]
** is non-zero, then reading column (a[i]-1) from cursor P3 is 
** equivalent to performing the deferred seek and then reading column i 
** from P1.  This information is stored in P3 and used to redirect
** reads against P3 over to P1, thus possibly avoiding the need to
** seek and read cursor P3.
*/
/* Opcode: IdxRowid P1 P2 * * *
** Synopsis: r[P2]=rowid
**
** 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.
**
** See also: Rowid, MakeRecord.
*/
case OP_Seek:
case OP_IdxRowid: {              /* out2 */
  VdbeCursor *pC;                /* The P1 index cursor */
  VdbeCursor *pTabCur;           /* The P2 table cursor (OP_Seek only) */
  i64 rowid;                     /* Rowid that P1 current points to */


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

  assert( pC->uc.pCursor!=0 );

  assert( pC->isTable==0 );
  assert( pC->deferredMoveto==0 );
  assert( !pC->nullRow || pOp->opcode==OP_IdxRowid );

  /* The IdxRowid and Seek opcodes are combined because of the commonality
  ** of sqlite3VdbeCursorRestore() and sqlite3VdbeIdxRowid(). */
  rc = sqlite3VdbeCursorRestore(pC);

  /* sqlite3VbeCursorRestore() can only fail if the record has been deleted
  ** out from under the cursor.  That will never happens for an IdxRowid
  ** or Seek opcode */


  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  if( !pC->nullRow ){
    rowid = 0;  /* Not needed.  Only used to silence a warning. */
    rc = sqlite3VdbeIdxRowid(db, pC->uc.pCursor, &rowid);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    if( pOp->opcode==OP_Seek ){
      assert( pOp->p3>=0 && pOp->p3<p->nCursor );
      pTabCur = p->apCsr[pOp->p3];
      assert( pTabCur!=0 );
      assert( pTabCur->eCurType==CURTYPE_BTREE );
      assert( pTabCur->uc.pCursor!=0 );
      assert( pTabCur->isTable );
      pTabCur->nullRow = 0;
      pTabCur->movetoTarget = rowid;
      pTabCur->deferredMoveto = 1;
      assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );
      pTabCur->aAltMap = pOp->p4.ai;
      pTabCur->pAltCursor = pC;
    }else{
      pOut = out2Prerelease(p, pOp);
      pOut->u.i = rowid;
      pOut->flags = MEM_Int;
    }
  }else{
    assert( pOp->opcode==OP_IdxRowid );
    sqlite3VdbeMemSetNull(&aMem[pOp->p2]);
  }
  break;
}

/* Opcode: IdxGE P1 P2 P3 P4 P5
** Synopsis: key=r[P3@P4]
**

** index, then the corresponding array entry is set to (i+1). If the column
** does not appear in the index at all, the array entry is set to 0.
*/
static void codeDeferredSeek(
  WhereInfo *pWInfo,              /* Where clause context */
  Index *pIdx,                    /* Index scan is using */
  int iCur,                       /* Cursor for IPK b-tree */

  int iIdxCur                     /* Index cursor */
){
  Parse *pParse = pWInfo->pParse; /* Parse context */
  Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */

  assert( iIdxCur>0 );
  assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
  
  sqlite3VdbeAddOp3(v, OP_Seek, iIdxCur, 0, iCur);
  if( (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)
   && sqlite3ParseToplevel(pParse)->writeMask==0 
  ){
    int i;
    Table *pTab = pIdx->pTable;
    int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
    if( ai ){

    /* Seek the table cursor, if required */
    disableTerm(pLevel, pRangeStart);
    disableTerm(pLevel, pRangeEnd);
    if( omitTable ){
      /* pIdx is a covering index.  No need to access the main table. */
    }else if( HasRowid(pIdx->pTable) ){
      if( pWInfo->eOnePass!=ONEPASS_OFF ){
        iRowidReg = ++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
        sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);

        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
        VdbeCoverage(v);
      }else{
        codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);
      }
    }else if( iCur!=iIdxCur ){
      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
      for(j=0; j<pPk->nKeyCol; j++){
        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);