Re: Join over two tables of 50K records takes 2 hours

Svetlin Manavski <svetlin(dot)manavski(at)gmail(dot)com> writes:
> I am running 9.03 with the settings listed below. I have a prohibitively
> slow query in an application which has an overall good performance:

It's slow because the planner is choosing a nestloop join on the
strength of its estimate that there's only a half dozen rows to be
joined. You need to figure out why those rowcount estimates are so bad.
I suspect that you've shot yourself in the foot by raising
autovacuum_analyze_threshold so high --- most likely, none of those
tables have ever gotten analyzed. And what's with the high
autovacuum_naptime setting? You might need to increase
default_statistics_target too, but first see if a manual ANALYZE makes
things better.

regards, tom lane