From: Chris Browne <cbbrowne@acm.org>
Subject: Re: Is it possible to start two instances of postgresql?
Date: Thu, 15 Jun 2006 11:01:51 -0400
Organization: cbbrowne Computing Inc
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To: pgsql-performance@postgresql.org

kah_hang_ang@toray.com.my writes:
> Is it possible to start two instances of postgresql with different port and
> directory which run simultaneously?

Certainly.  We have one HACMP cluster which hosts 14 PostgreSQL
instances across two physical boxes.  (If one went down, they'd all
migrate to the survivor...)

> If can then will this cause any problem or performance drop down?

There certainly can be; the databases will be sharing disks, memory,
and CPUs, so if they are avidly competing for resources, the
competition is sure to have some impact on performance.

Flip side: That 14 database cluster has several databases that are
known to be very lightly used; they *aren't* competing, and aren't a
problem.

Consider it obvious that if you haven't enough memory or I/O bandwidth
to cover your two PG instances, you'll find performance sucks...  If
you have enough, then it can work fine...
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