On Mon, Jul 13, 2009 at 3:53 PM, Dan Armbrust<daniel.armbrust.list@xxxxxxxxx> wrote: >> So this thought leads to a couple of other things Dan could test. >> First, see if turning off full_page_writes makes the hiccup go away. >> If so, we know the problem is in this area (though still not exactly >> which reason); if not we need another idea. That's not a good permanent >> fix though, since it reduces crash safety. The other knobs to >> experiment with are synchronous_commit and wal_sync_method. If the >> stalls are due to commits waiting for additional xlog to get written, >> then async commit should stop them. I'm not sure if changing >> wal_sync_method can help, but it'd be worth experimenting with. >> >> regards, tom lane >> > > > All of my testing to date has been done with synchronous_commit=off > > I just tried setting full_page_writes=off - and like magic, the entire > hiccup went away. > > Thanks, > > Dan I haven't done any other testing for this issue since discovering that setting "full_page_writes=off" makes my performance hiccup go away. I'm about to move on to some different tests and reset this setup that I was using to test out this issue - is there anything else that anyone would like to have gathered before I axe this system? I can redo it again later too, it will just take a fair bit longer for me to reconfigure the test environment. Thanks, Dan -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
