From: Greg Smith <gsmith@gregsmith.com>
To: Ivan Voras <ivoras@geri.cc.fer.hr>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance tuning on FreeBSD
Date: Tue, 4 Mar 2008 11:25:25 -0500 (EST)
Message-ID: <Pine.GSO.4.64.0803041118150.8745@westnet.com> (raw)
In-Reply-To: <fqjkst$sgp$1@ger.gmane.org>
References: <892916310803031539scffd5bchcce5a848b3a57a32@mail.gmail.com>
<Pine.GSO.4.64.0803032005020.23114@westnet.com>
<fqjkst$sgp$1@ger.gmane.org>
On Tue, 4 Mar 2008, Ivan Voras wrote:
> I'm curious about the math behind this - is ~4000 burst or sustained
> rate?
Average, which is not quite burst or sustained. No math behind it, just
looking at a few samples of pgbench data on similar hardware. A system
like this one is profiled at
http://www.kaltenbrunner.cc/blog/index.php?/archives/21-8.3-vs.-8.2-a-simple-benchmark.html
for example.
> For common BBU cache sizes (256M, 512M), filling that amount with data
> is pretty trivial.
I don't have any good numbers handy but I think the burst is >6000, you
only get that for a few seconds before all the caches fill and the rate
drops considerably.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
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To: pgsql-performance@postgresql.org
Cc: gsmith@gregsmith.com, ivoras@geri.cc.fer.hr
Subject: Re: Performance tuning on FreeBSD
In-Reply-To: <Pine.GSO.4.64.0803041118150.8745@westnet.com>
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