Jeffrey Tenny <jeffrey.tenny@xxxxxxxxxxx> writes: > I dropped the multicolumn index 'testindex2', and a new explain analyze > looks like this: > Sort (cost=35730.71..35768.28 rows=1503 width=16) (actual > time=962.555..964.467 rows=677 loops=1) > Sort Key: f, c > -> Seq Scan on x (cost=0.00..34937.60 rows=1503 width=16) (actual > time=5.449..956.594 rows=677 loops=1) > Filter: ((f = 1) OR (f = 2) OR (f = 3) ... > Turning on the server debugging again, I got roughly identical > query times with and without the two column index. That's good, actually, seeing that the planner thinks they're close to the same speed too. Now try "set enable_seqscan = off" to see if you can force the multi-index-scan plan to be chosen, and see how that does. regards, tom lane