Message-ID: <4CD47FCD.6010106@2ndquadrant.com>
Date: Fri, 05 Nov 2010 15:06:05 -0700
From: Greg Smith <greg@2ndquadrant.com>
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To: Marti Raudsepp <marti@juffo.org>
CC: Andres Freund <andres@anarazel.de>, pgsql-performance@postgresql.org
Subject: Re: Defaulting wal_sync_method to fdatasync on Linux for
 9.1?
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	<201011010010.28724.andres@anarazel.de>
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Marti Raudsepp wrote:
> In fact, I was wrong in my earlier post. Linux always offered O_DSYNC
> behavior. What's new is POSIX-compliant O_SYNC, and the fact that
> these flags are now distinguished.
>   

While I appreciate that you're trying to help here, I'm unconvinced 
you've correctly diagnosed a couple of components to what's going on 
here properly yet.  Please refrain from making changes to popular 
documents like the tuning guide on the wiki based on speculation about 
what's happening.  There's definitely at least one mistake in what you 
wrote there, and I just reverted the whole set of changes you made 
accordingly until this is sorted out better.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services and Support        www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books