On Wed, Nov 17, 2010 at 01:31, Tom Lane <t...@sss.pgh.pa.us> wrote: > Well, we're not going to increase the default to gigabytes, but we could > very probably increase it by a factor of 10 or so without anyone > squawking. It's been awhile since I heard of anyone trying to run PG in > 4MB shmmax. How much would a change of that size help?
In my testing, when running a large bulk insert query with fdatasync on ext4, changing wal_buffers has very little effect: http://ompldr.org/vNjNiNQ/wal_sync_method1.png (More details at http://archives.postgresql.org/pgsql-performance/2010-11/msg00094.php ) It would take some more testing to say this conclusively, but looking at the raw data, there only seems to be an effect when moving from 8 to 16MB. Could be different on other file systems though. Regards, Marti -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
