Re: Postgres not using indexes

Lawrence Cohan <LCohan@web.com> wrote:

> We have a huge performance issues in Postgres that surfaced due to
> existing indexes not being used

This doesn't sound like a bug; it sounds like you haven't tuned your
server.

For starters, you should check out this page:

http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server

As a quick try, you could issue these statements on the connection
right before one of the problem queries:

set effective_cache_size = '7GB';
  -- use 1 or 2 GB less than RAM on the machine
set random_page_cost = 2;
-- now try your query

If, after reading the above-cited page and tuning your server you
still have performance problems, pick one query to work on first,
and follow the step outlined here:

http://wiki.postgresql.org/wiki/SlowQueryQuestions

Use the pgsql-performance list for performance issues, not the bugs
list.  You'll find more people who will be able to help you with
performance issues there.

-Kevin