> Any ideas on any of this? Why the sawteeth? Why the rise-then-drop?
Well, my first thought on the sawteeth is that you have archive_timeout
set to 15 minutes. No?
As for the gradual buildup over days, that most likely corresponds to
either changes in application activity levels, or some kind of weekly
data purge cycle which shrinks your database every weekend. Since I
don't know anything about your admin or your application, that's a best
guess.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com