Ok, well, I dropped the DB and reloaded it and now all seems to be fine and performing well. I'm not sure what was going on before. Thanks for everyone's help! Alex On 4/3/07, Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
On 4/3/07, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > "Alex Deucher" <alexdeucher@xxxxxxxxx> writes: > > Turning off bitmapscan ends up doing a sequential scan. Turning off > > both bitmapscan and seqscan results in a bitmap heap scan. It doesn't > > seem to want to use the index at all. Any ideas? > > The "ORed indexscans" plan style that was in 7.4 isn't there anymore; > we use bitmap OR'ing instead. There actually are repeated indexscans > hidden under the "= ANY" indexscan condition in 8.2, it's just that > the mechanism for detecting duplicate matches is different. AFAIK the > index access costs ought to be about the same either way, and the other > costs the same or better as what we did in 7.4. It's clear though that > 8.2 is taking some kind of big hit in the index access in your case. > There's something very strange going on here. > > You do have both lc_collate and lc_ctype set to C, right? What about > database encoding? > hmmm... ok, this is weird. performance seems to have improved significantly after I reloaded postgres after adding some hew hosts to the pg_hba.conf. I'll run some more tests and let you know what happens. Alex