Re: possible new option for wal_sync_method

Marti Raudsepp <marti@juffo.org>

From: Marti Raudsepp <marti@juffo.org>
To: Dan Scales <scales@vmware.com>
Cc: PG Hackers <pgsql-hackers@postgresql.org>
Date: 2012-02-16T19:49:43Z
Lists: pgsql-hackers
On Thu, Feb 16, 2012 at 19:18, Dan Scales <scales@vmware.com> wrote:
> fsync/fdatasync can be very slow on ext3, because it seems to have to
> always wait for the current filesystem meta-data transaction to complete,
> even if that meta-data operation is completely unrelated to the file
> being fsync'ed.

Use the data=writeback mount option to remove this restriction. This
is actually the suggested setting for PostgreSQL file systems:
http://www.postgresql.org/docs/current/static/wal-intro.html

(Note that this is unsafe for some other applications, so I wouldn't
use it on the root file system)

Regards,
Marti