Subject: Re: wal_buffers
From: Ian Westmacott <ianw@intellivid.com>
To: "Thomas F. O'Connell" <tfo@sitening.com>
Cc: pgsql-performance@postgresql.org
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References: <1128518624.15795.28.camel@spectre.intellivid.com>
	<C140F925-0D7D-41B4-873A-6C81C0D3D307@sitening.com>
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Organization: Intellivid Corp.
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Date: Thu, 06 Oct 2005 08:56:31 -0400
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On Thu, 2005-10-06 at 02:39, Thomas F. O'Connell wrote:
> The WAL Configuration chapter (25.2) has a pretty good discussion of  
> how wal_buffers is used:
> 
> http://www.postgresql.org/docs/8.0/static/wal-configuration.html
> 
> You might also take a look at Josh Berkus' recent testing on this  
> setting:
> 
> http://www.powerpostgresql.com/

Thanks; I'd seen the documentation, but not Josh Berkus'
testing.

For my part, I don't have a large number of concurrent
connections, only one.  But it is doing large writes,
and XLogInsert is number 2 on the profile (with
LWLockAcquire and LWLockRelease close behind).  I suppose
that is expected, but lead by the documentation I wanted
to make sure XLogInsert always had some buffer space to
play with.

	--Ian