Received: from localhost (unknown [200.46.204.183])
	by developer.postgresql.org (Postfix) with ESMTP id 40A922E0082
	for <pgsql-hackers-postgresql.org@developer.postgresql.org>;
	Wed, 11 Jun 2008 13:37:51 -0300 (ADT)
Received: from developer.postgresql.org ([200.46.204.71])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 72807-02-3
	for <pgsql-hackers-postgresql.org@developer.postgresql.org>;
	Wed, 11 Jun 2008 13:37:44 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from sca-es-mail-1.sun.com (sca-es-mail-1.Sun.COM [192.18.43.132])
	by developer.postgresql.org (Postfix) with ESMTP id 7B1502E0043
	for <pgsql-hackers@postgresql.org>;
	Wed, 11 Jun 2008 13:37:31 -0300 (ADT)
Received: from fe-sfbay-09.sun.com ([192.18.43.129])
	by sca-es-mail-1.sun.com (8.13.7+Sun/8.12.9) with ESMTP id
	m5BGbVF4002332 for <pgsql-hackers@postgresql.org>;
	Wed, 11 Jun 2008 09:37:31 -0700 (PDT)
Received: from conversion-daemon.fe-sfbay-09.sun.com by fe-sfbay-09.sun.com
	(Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007))
	id <0K2B00F014NYYY00@fe-sfbay-09.sun.com>
	(original mail from josh@agliodbs.com) for pgsql-hackers@postgresql.org;
	Wed, 11 Jun 2008 09:37:31 -0700 (PDT)
Received: from josh-berkus-computer-2.local ([64.81.245.111])
	by fe-sfbay-09.sun.com
	(Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007))
	with ESMTPSA id <0K2B00HBE4UCPX80@fe-sfbay-09.sun.com>; Wed,
	11 Jun 2008 09:37:24 -0700 (PDT)
Date: Wed, 11 Jun 2008 09:37:22 -0700
From: Josh Berkus <josh@agliodbs.com>
Subject: Re: Overhauling GUCS
In-reply-to: <21875.1213122184@sss.pgh.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org, Robert Treat <xzilla@users.sourceforge.net>,
	Peter Eisentraut <peter_e@gmx.net>, Greg Smith <gsmith@gregsmith.com>,
	Andreas Pflug <pgadmin@pse-consulting.de>, Decibel! <decibel@decibel.org>
Message-id: <484FFF42.7000408@agliodbs.com>
MIME-version: 1.0
Content-type: text/plain; format=flowed; charset=UTF-8
Content-transfer-encoding: 7BIT
References: <48409D1E.3070208@agliodbs.com>
	<200806061624.29105.xzilla@users.sourceforge.net>
	<200806100937.38124.josh@agliodbs.com>
	<200806100949.17918.josh@agliodbs.com>
	<21875.1213122184@sss.pgh.pa.us>
User-Agent: Thunderbird 2.0.0.14 (Macintosh/20080421)
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200806/513
X-Sequence-Number: 119626

Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>> Oh, and wal_buffers, the default for which we should just change if it
>> weren't for SHMMAX.
> 
> Uh, why?  On a workload of mostly small transactions, what value is
> there in lots of wal_buffers?

Actually, it's also useful for any workload with many connections.  Any 
time you have high throughput, really.  We've seen this on DBT2, 
SpecJAppserver and iGen.

--Josh