Mark Kirkwood wrote:
8.2 is deciding to use a bitmap index scan on taskid_taskinstance_key, which seems to be slower (!) than a plain old index scan that 8.0 is using. A dirty work around is to disable bitmap scans via:
I'm having difficulty figuring out why it's doing this at all. There's only one index involved, and it's over the primary-key to boot!
An EXPLAIN ANALYSE with enable_bitmapscan off should say why PG thinks the costs are cheaper than they actually are.
PS - well worded question Kurt. All the relevant information neatly laid out, explain analyse on both platforms - you should be charging to let people help ;-)
-- Richard Huxton Archonet Ltd
