How to reduce impact of a query.

Hi,

I am running multiple 8.2 databases on a not-so-powerful W2K3 server -
and it runs great - for the majority of time. However I have some
monster tsearch queries which take a lot of processing and hog system
resources - especially disk.

I am not concerned with the amount of time or speed of the tsearch2
query, which is doing a lot of work, all I need to do is make sure that
the query does not impact all other databases and queries running on the
same machine.

The machine in question is a 1GB Ram, AMD 64 with Raid 1 Sata disks. Non
standard parts of my postgresql.conf are as follows:
max_connections=100
shared_buffers=128MB
work_mem=4MB
maintenance_work_mem=256MB
max_fsm_pages=204800
max_fsm_relations=1500

Any tips appreciated.

Howard.
www.selestial.com