On Thu, May 25, 2006 at 04:07:19PM -0400, Merlin Moncure wrote: > been doing a lot of pgsql/mysql performance testing lately, and there > is one query that mysql does much better than pgsql...and I see it a > lot in normal development: > > select a,b,max(c) from t group by a,b; > > t has an index on a,b,c.
The planner _should_ TTBOMK be able to do it by itself in 8.1, but have you tried something along the following lines? select a,b,(select c from t t2 order by c desc where t1.a=t2.a and t1.b=t2.b) from t t1 group by a,b; /* Steinar */ -- Homepage: http://www.sesse.net/ ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
