Run 4 postgresql session on ONE server?

Hello,
I only know the traditional way of using postgreSQL:
In serverprocess with an "unlimited" number of databases.
But:
Is is possible to have 4 processes, for each database one, running on one
linux server?

The reason is the following:
I only have one server on which a productive database is working and a
second database, which will be set upped at the moment.
On my productive database I can't test with the parameters so I am searching
for a way, that I can do the following:
- let running for each database one serverprocess on the same machine
- having for each database one pg_hba.conf and postgresql.conf (on testdb's,
I want to log every SQL-statement, which is on a productive database
impossible to log)

I know, that you shouldn't test on a productive server, but at the moment
this is the only way I can do but I hope to get an test server or a new
productive server as soon as the second database is ready.

Thank you in advance for your answers

Daniel Seichter
--
postgreSQL on Netware - the red elephant
http://postgresql.dseichter.org
Last update: 26th May 2003