Re: no universally correct setting for fsync

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Bernd Helmle <mailings@oopsware.de>
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>, Andrew Dunstan <andrew@dunslane.net>, pgsql-hackers@postgresql.org
Date: 2010-05-07T23:49:15Z
Lists: pgsql-hackers
Bernd Helmle <mailings@oopsware.de> writes:
> I've recently even started to wonder if the performance gain with fsync=off 
> is still that large on modern hardware. While testing large migration 
> procedures to a new version some time ago (on an admitedly fast storage) i 
> forgot here and then to turn it off, without a significant degradation in 
> performance.

That says to me either that you're using a battery-backed write cache,
or your fsyncs don't really work (no write barriers or something like
that).

			regards, tom lane