On 2016-03-07 09:41:51 -0800, Andres Freund wrote: > > Due to the difference in amount of RAM, each machine used different scales - > > the goal is to have small, ~50% RAM, >200% RAM sizes: > > > > 1) Xeon: 100, 400, 6000 > > 2) i5: 50, 200, 3000 > > > > The commits actually tested are > > > > cfafd8be (right before the first patch) > > 7975c5e0 Allow the WAL writer to flush WAL at a reduced rate. > > db76b1ef Allow SetHintBits() to succeed if the buffer's LSN ... > > Huh, now I'm a bit confused. These are the commits you tested? Those > aren't the ones doing sorting and flushing?
To clarify: The reason we'd not expect to see much difference here is that the above commits really only have any affect above noise if you use synchronous_commit=off. Without async commit it's just one additional gettimeofday() call and a few additional branches in the wal writer every wal_writer_delay. Andres -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers