From: Alan Hodgson <ahodgson@simkin.ca>
To: pgsql-performance@postgresql.org
Subject: Re: CPU Usage
Date: Tue, 13 Feb 2007 10:48:25 -0800
Message-ID: <200702131048.25646@hal.simkin.ca> (raw)
In-Reply-To: <A3AC4FA47DC0B1458C3E5396E685E63302395CCE@SAB-DC1.sab.uiuc.edu>
References: <A3AC4FA47DC0B1458C3E5396E685E63302395CCE@SAB-DC1.sab.uiuc.edu>
On Tuesday 13 February 2007 10:36, "Campbell, Lance" <lance@uiuc.edu>
wrote:
> We have 12+ schemas in 1 database. When I do a unix "top" command I
> notice one postmaster process has 100% CPU usage. This process just
> stays at 100% to 99% CPU usage. There are other postmaster processes
> that pop up. They use hardly no CPU or memory. They also disappear
> very fast. I am wondering, is postgres only using one processor for
> database queries? Is there something I need to do to tell postgres
> to use more than one processor? Or does postgres only use up to one
> processor for any particular database?
Each connection to the cluster gets a dedicated backend process, which
can only be scheduled on one processor at a time. So, in effect, a
single query can only use one processor at a time, but any number of
other backends can be simultaneously using the other CPUs. It does not
matter which database they are operating on.
--
"It is a besetting vice of democracies to substitute public opinion for
law." - James Fenimore Cooper
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: ahodgson@simkin.ca
Subject: Re: CPU Usage
In-Reply-To: <200702131048.25646@hal.simkin.ca>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox