OR clause - check code - Mailing list pgsql-hackers

Vadim, would you please review this code, and let me know if it is
correct.  I am unsure about the calls to ExecStoreTuple(), ExecQual()
(is proper context used?), and placement of ReleaseBuffer().  Do I need
to free the tuple buffer if I decide it doesn't meet my ExecQual test?

You will see the old code, then the new for IndexNext().

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


***************
*** 120,155 ****
     *  appropriate heap tuple.. else return NULL.
     * ----------------
     */
!   while ((result = index_getnext(scandesc, direction)) != NULL)
    {
!       tuple = heap_fetch(heapRelation, false, &result->heap_iptr, &buffer);
!       /* be tidy */
!       pfree(result);
!
!       if (tuple != NULL)
        {
!           /* ----------------
!            *  store the scanned tuple in the scan tuple slot of
!            *  the scan state.  Eventually we will only do this and not
!            *  return a tuple.  Note: we pass 'false' because tuples
!            *  returned by amgetnext are pointers onto disk pages and
!            *  were not created with palloc() and so should not be pfree()'d.
!            * ----------------
!            */
!           ExecStoreTuple(tuple,       /* tuple to store */
!                           slot,       /* slot to store in */
!                           buffer,     /* buffer associated with tuple  */
!                           false);     /* don't pfree */
!
!           return slot;
!       }
!       else
!       {
            if (BufferIsValid(buffer))
                ReleaseBuffer(buffer);
        }
    }
-
    /* ----------------
     *  if we get here it means the index scan failed so we
     *  are at the end of the scan..
--- 119,170 ----
     *  appropriate heap tuple.. else return NULL.
     * ----------------
     */
!   while (indexstate->iss_IndexPtr < numIndices)
    {
!       scandesc = scanDescs[indexstate->iss_IndexPtr];
!       while ((result = index_getnext(scandesc, direction)) != NULL)
        {
!           tuple = heap_fetch(heapRelation, false, &result->heap_iptr, &buffer);
!           /* be tidy */
!           pfree(result);
!
!           if (tuple != NULL)
!           {
!               bool        prev_matches = false;
!               int         prev_index;
!
!               /* ----------------
!                *  store the scanned tuple in the scan tuple slot of
!                *  the scan state.  Eventually we will only do this and not
!                *  return a tuple.  Note: we pass 'false' because tuples
!                *  returned by amgetnext are pointers onto disk pages and
!                *  were not created with palloc() and so should not be pfree()'d.
!                * ----------------
!                */
!               ExecStoreTuple(tuple,       /* tuple to store */
!                               slot,       /* slot to store in */
!                               buffer,     /* buffer associated with tuple  */
!                               false);     /* don't pfree */
!
!               for (prev_index = 0; prev_index < indexstate->iss_IndexPtr;
!                                                               prev_index++)
!               {
!                   if (ExecQual(nth(prev_index, node->indxqual),
!                       scanstate->cstate.cs_ExprContext))
!                   {
!                       prev_matches = true;
!                       break;
!                   }
!               }
!               if (!prev_matches)
!                   return slot;
!           }
            if (BufferIsValid(buffer))
                ReleaseBuffer(buffer);
        }
+       if (indexstate->iss_IndexPtr < numIndices)
+           indexstate->iss_IndexPtr++;
    }
    /* ----------------
     *  if we get here it means the index scan failed so we
     *  are at the end of the scan..

--
Bruce Momjian                          |  830 Blythe Avenue
maillist@candle.pha.pa.us              |  Drexel Hill, Pennsylvania 19026
  +  If your life is a hard drive,     |  (610) 353-9879(w)
  +  Christ can be your backup.        |  (610) 853-3000(h)