On Wed, Mar 30, 2011 at 7:32 PM, Lawrence Cohan <lco...@web.com> wrote: > Please see updated attachment that includes the tables involved in the simple > query below and all their indexes. We believe that the performance issue is > due to the query not using any index but doing seq scans instead and this is > very little related to the knowledge from the link you posted below. As you > can see we picked a simple query with INNER JOIN between two indexed tables > where postgres 8.3 and 9.0 decides to not use existing indexes for whatever > reason.
Have you tried using enable_seqscan = off and looked at the explain output then? I think you'll find Postgres is choosing not to use the indexes because they're just not helpful. If you disable seqscan it should use the indexes but I expect it will be slower. The current plan is doing a single pass through both tables using entirely sequential i/o. That's about as fast as you could hope for it to be as your query does require reading all the data. -- greg -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
