Re: SELECT Aggregate

> I've tried Aaron's suggestion of the GROUP BY and I don't know much about
> it, but it ran for around 17 hours and still going (it had a dedicated Dual
> Xeon 3.0GHz box under RHEL4 running it!)

Maybe, this query that you are trying to run is a good candidate for a "Materialize View".
http://archives.postgresql.org/pgsql-performance/2004-02/msg00279.php

Also before you run your query you might want to see the explain plan is.  Perhap it is using a
sequencial scan in a place where an index can improve query preformance.