> -----Original Message----- > From: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance- > owner@xxxxxxxxxxxxxx] On Behalf Of george young > Sent: Monday, March 27, 2006 12:48 PM > To: pgsql-performance@xxxxxxxxxxxxxx > Subject: [PERFORM] simple join uses indexes, very slow > [Snip] > > Indexes: > "parameters_idx" btree (run, opset_num, step_num, opset, opset_ver, > step, step_ver, name, split, wafers) > "parameters_opset_idx" btree (opset, step, name) > "parameters_step_idx" btree (step, name) > Have you tried creating some different indexes on parameters? I don't know if it should matter or not, but I would try some indexes like: (run, opset_num) //Without all the other columns (opset_num, run) //Backwards (opset_num) I don't really know Postgres internals all that well. It just seems to me that parameters_idx has a lot of columns this query is not interested in. I'd just be curious to see what happens.