Re: 7.4 aggregate OR TRUE yields strange results

"SZŰCS Gábor" <surrano@mailbox.hu> writes:
> SELECT count(*)<0 OR TRUE FROM mytable WHERE condition
> dumps the whole tuples meeting the condition.

Sigh, I'm an idiot.  I introduced this bug more than a year ago.
(Bit surprising that it wasn't caught already...)  Patch against 7.4.*
is attached.
        regards, tom lane

Index: planner.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/optimizer/plan/planner.c,v
retrieving revision 1.161
diff -c -r1.161 planner.c
*** planner.c    25 Sep 2003 06:58:00 -0000    1.161
--- planner.c    13 Feb 2004 22:22:26 -0000
***************
*** 701,719 ****          /*          * Will need actual number of aggregates for estimating costs.
-          * Also, it's possible that optimization has eliminated all
-          * aggregates, and we may as well check for that here.          *          * Note: we do not attempt to
detectduplicate aggregates here; a          * somewhat-overestimated count is okay for our present purposes.
*/        if (parse->hasAggs) 
-         {             numAggs = count_agg_clause((Node *) tlist) +
count_agg_clause(parse->havingQual);
-             if (numAggs == 0)
-                 parse->hasAggs = false;
-         }          /*          * Figure out whether we need a sorted result from query_planner.
--- 701,718 ----          /*          * Will need actual number of aggregates for estimating costs.          *
*Note: we do not attempt to detect duplicate aggregates here; a          * somewhat-overestimated count is okay for our
presentpurposes. 
+          *
+          * Note: think not that we can turn off hasAggs if we find no aggs.
+          * It is possible for constant-expression simplification to remove
+          * all explicit references to aggs, but we still have to follow the
+          * aggregate semantics (eg, producing only one output row).          */         if (parse->hasAggs)
 numAggs = count_agg_clause((Node *) tlist) +                 count_agg_clause(parse->havingQual);          /*
*Figure out whether we need a sorted result from query_planner.