> You could check for volatile functions. I think this could be done safely. I don't think that's enough. A UDA like last() could have an immutable sfunc, but still be sensitive to the sort order. I think you'd need something like a special order-sensitive aggregate definition flag. --- Maciek Sakrejda | System Architect | Truviso 1065 E. Hillsdale Blvd., Suite 215 Foster City, CA 94404 (650) 242-3500 Main www.truviso.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance