From: Tom Lane <tgl@sss.pgh.pa.us>
To: Theo Galanakis <Theo.Galanakis@lonelyplanet.com.au>
Cc: pgsql-sql@postgresql.org
Subject: Re: Process priority.
Date: Thu, 17 Mar 2005 19:06:01 -0500
Message-ID: <28823.1111104361@sss.pgh.pa.us> (raw)
In-Reply-To: <D1444817B78AB546BF2896C2B70E7F04371F6D@ganesh.au.lpint.net>
References: <D1444817B78AB546BF2896C2B70E7F04371F6D@ganesh.au.lpint.net>
Theo Galanakis <Theo.Galanakis@lonelyplanet.com.au> writes:
> I wrote a C program that can be called through postgres via stored
> procedures. It allows you to change the current postmaster process priority.
You are aware that that's widely considered either useless or
counterproductive? Renice-ing one backend seldom gives helpful results,
because (a) what usually matters more than CPU usage is I/O, and renice
doesn't change I/O priorities; (b) priority inversion results in
higher-priority backends blocking behind the low-priority one whenever
it's managed to acquire a lock.
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, Theo.Galanakis@lonelyplanet.com.au
Subject: Re: Process priority.
In-Reply-To: <28823.1111104361@sss.pgh.pa.us>
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