PostgreSQL Performance Issue on Mail Server

Mr. Peddermors,

"We have a postgres backend to our Mail Server product, and encountering
performance issues. Simple selects are taking 7-10 seconds..
We have of course applied all the suggested performance settings for Postgres,
(We are running on Debian Stable/Linux BTW)
We moved the database to a standalone server, but still having the problems.
With app 100,000 users authenticating pop mail, plus all of the smtp
verfications, the server is expected to perform snappy queries, else mail
delivery/pickup is inordintaely long, or can't occur, and loads snowball.."

I've cc'd your question to PGSQL-Performance list. Can you give us a few
examples of EXPLAIN ANALYZE output for the queries which are running slow?
(as well as the queries themeselves)? It's possible that you have a
platform issue on Debian, but far more likely that this is a garden-variety
performance tuning issue.

If this is a business-critical issue, I suggest that you retain a PostgreSQL
consultant, such as PostgreSQL Inc., myself, or Justin Clift.

--
Josh Berkus
Aglio Database Solutions
San Francisco