On Thu, 29 Jan 2004, Tom Lane wrote: > > jackdb-# GROUP BY memberid_ HAVING ( > > Um, that's not what I had in mind at all. Does GROUP BY actually do > anything at all here? (You didn't answer me as to whether memberid_ > is a unique identifier or not, but if it is, this GROUP BY is just an > expensive no-op.)
>From your comment I assume that there is no transformation in pg that detects that the group by columns are unique? > this is all blue-sky speculation anyway. What I'm actually more > interested in is your statement that MSSQL can do the original query > quickly. I find that a bit hard to believe because I don't see any > relevant optimization techniques. Getting rid of the group by would not give that kind of speedup? Maybe mssql manage to rewrite the query like that before executing. -- /Dennis Björklund ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org