2012/8/6 Magnus Hagander <mag...@hagander.net>: > On Mon, Aug 6, 2012 at 4:16 PM, Pavel Stehule <pavel.steh...@gmail.com> wrote: >> 2012/8/6 Magnus Hagander <mag...@hagander.net>: >>> That's not a good way of doing it, since you loose persistent storage. >>> >>> Instead, you should set the stats_temp_dir paramter to a filesystem >>> somewhere else that is tmpfs. Then PostgreSQL will automatically move >>> the file to and from the main data directory on startup and shutdown, >>> so you get both the performance of tmpfs and the persistent >>> statistics. >> >> we had to do it because our read/write of stat file created really >> high IO - and it was problem on Amazon :( - probably we had not this >> issue elsewhere > > Uh. You realize that if you set stats_temp_dir, it only ever writes to > the persistent storage once, when you do "pg_ctl stop" (or > equivalent). Are you saying the shutdown took too long? > > I've had to change that param many times on Amazon, but I've never had > a problem with the shutdown writes. (And I've seen it often enough on > dedicated hardware as well..) aha, this is my mistake - we use a stats_temp_directory GUC already - my advice was use a tmpfs for statfile, but I though realize it via stats_temp_directory, but I didn't say it.
Regards Pavel > > -- > Magnus Hagander > Me: http://www.hagander.net/ > Work: http://www.redpill-linpro.com/ -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
