On Tue, 26 May 2009, Mark Wong wrote:
Maybe there isn't enough activity to the WAL relative to the rest of the database to show anything interesting?
Maybe you could reduce checkpoint_segments and focus on UPDATEs? That's how I've been able to generate the most WAL activity relative to database writes in the past, because of the full_page_writes behavior. Quoth the docs: "To ensure data page consistency, the first modification of a data page after each checkpoint results in logging the entire page content. In that case, a smaller checkpoint interval increases the volume of output to the WAL log, partially negating the goal of using a smaller interval, and in any case causing more disk I/O."
You've got checkpoint_segments set to 3000 in your tests and checkpoint_time to 1 hour, which means the tests you ran are really generating minimal WAL volume.
-- * Greg Smith gsm...@gregsmith.com http://www.gregsmith.com Baltimore, MD -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
