Wim,
> I encounter a major problem: I've running Postgres 7.1 on a Sun 220R
> (with only one processor). Postgres has a database with a table with
> more than 300000 rows. The lay-out of my table is:
In addition to the suggestions from PGMail, you may want to look at
your hardware setup and PostgreSQL runtime parameters if you're
looking for speed. Check out this article written by Bruce Momjian:
http://www.ca.postgresql.org/docs/momjian/hw_performance/
And this one by Jean-Paul Argudo:
http://techdocs.postgresql.org/techdocs/pgsqldbtuning.php
-Josh Berkus