Parallel Postgresql

Hello,

I have a user with a postgresql database running on a Linux cluster.
They would like to use the cluster to speed up an individual query.
I've found the product Clusgres [1], but that is more oriented towards
making multiple queries run in parallel.  I would need a single query to
be sped up.

A little searching turns up some info that Oracle, DB2, Informix, and
maybe others can do this, but I couldn't find anything for Postgresql.
If it isn't already in Postgresql, how hard would it be to implement?

Thanks,
Walter Landry
landry@osc.edu

[1] http://www.linuxlabs.com/clusgres.html