Re: [HACKERS] What's wrong with this group by clause?

Thanks Tom, I applied the patch and it works perfect now.
Thanks to you all.

On Thursday 13 March 2003 14:02, Tom Lane wrote:
> Manfred Koizar <mkoi-pg@aon.at> writes:
> > ISTM you have found a Postgres 7.3 bug.
>
> Yeah.  Actually, the planner bug has been there a long time, but it was
> only latent until the parser stopped suppressing duplicate GROUP BY
> items:
>
> 2002-08-18 14:46  tgl
>
>     * src/backend/parser/parse_clause.c: Remove optimization whereby
>     parser would make only one sort-list entry when two equal()
>     targetlist items were to be added to an ORDER BY or DISTINCT list.
>     Although indeed this would make sorting fractionally faster by
>     sometimes saving a comparison, it confuses the heck out of later
>     stages of processing, because it makes it look like the user wrote
>     DISTINCT ON rather than DISTINCT.  Bug reported by
>     joe@piscitella.com.
>
> 7.3 patch is attached if you need it.
>
>             regards, tom lane
>
>
> *** src/backend/optimizer/plan/planner.c.orig    Wed Mar  5 13:38:26 2003
> --- src/backend/optimizer/plan/planner.c    Thu Mar 13 11:21:16 2003
> ***************
> *** 1498,1510 ****
>            * are just dummies with no extra execution cost.)
>            */
>           List       *sort_tlist = new_unsorted_tlist(subplan->targetlist);
>           int            keyno = 0;
>           List       *gl;
>
>           foreach(gl, groupClause)
>           {
>               GroupClause *grpcl = (GroupClause *) lfirst(gl);
> !             TargetEntry *te = nth(grpColIdx[keyno] - 1, sort_tlist);
>               Resdom       *resdom = te->resdom;
>
>               /*
> --- 1498,1511 ----
>            * are just dummies with no extra execution cost.)
>            */
>           List       *sort_tlist = new_unsorted_tlist(subplan->targetlist);
> +         int            grpno = 0;
>           int            keyno = 0;
>           List       *gl;
>
>           foreach(gl, groupClause)
>           {
>               GroupClause *grpcl = (GroupClause *) lfirst(gl);
> !             TargetEntry *te = nth(grpColIdx[grpno] - 1, sort_tlist);
>               Resdom       *resdom = te->resdom;
>
>               /*
> ***************
> *** 1518,1523 ****
> --- 1519,1525 ----
>                   resdom->reskey = ++keyno;
>                   resdom->reskeyop = grpcl->sortop;
>               }
> +             grpno++;
>           }
>
>           Assert(keyno > 0);