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Date: Fri, 26 Mar 2010 08:00:38 -0600
Message-ID: <dcc563d11003260700i71f4c974o27b3f1db2f9ef609@mail.gmail.com>
Subject: Re: Why Wal_buffer is 64KB
From: Scott Marlowe <scott.marlowe@gmail.com>
To: Pierre C <lists@peufeu.com>
Cc: Tadipathri Raghu <traghu.dba@gmail.com>,
	Jaime Casanova <jcasanov@systemguards.com.ec>,
	pgsql-performance@postgresql.org
Content-Type: text/plain; charset=ISO-8859-1

On Fri, Mar 26, 2010 at 7:43 AM, Pierre C <lists@peufeu.com> wrote:
>
>> After fsync/syncronous_commit off
>
> Do not use fsync off, it is not safe. Who cares about the performance of
> fsync=off, when in practice you'd never use it with real data.
> synchronnous_commit=off is fine for some applications, though.

There are situations where it's ok, when all the data are
reproduceable from other sources, etc.  for instance I have a
reporting server that is a slony slave that runs with fsync off.  If
it does crash and I can recreate the node in an hour or so and be back
online.  With fsync off the machine is too slow to do its job, and
it's not the primary repo of the real data, so it's ok there.