Stephen Frost <sfr...@snowman.net> writes: > * Josh Berkus (j...@agliodbs.com) wrote: >> Yeah, I can't believe I'm calling for *yet another* configuration >> variable either. Suggested workaround fixes very welcome.
> As I suggested on IRC, my thought would be to have a goal-based system > for autovacuum which is similar to our goal-based commit system. We > don't need autovacuum sucking up all the I/O in the box, nor should we > ask the users to manage that. Instead, let's decide when the autovacuum > on a given table needs to finish and then plan to keep on working at a > rate that'll allow us to get done well in advance of that deadline. If we allow individual vacuum operations to stretch out just because they don't need to be completed right away, we will need more concurrent vacuum workers (so that we can respond to vacuum requirements for other tables). So I submit that this would only move the problem around: the number of active workers would increase to the point where things are just as painful, plus or minus a bit. The intent of the autovacuum cost delay features is to ensure that autovacuum doesn't suck an untenable fraction of the machine's I/O capacity, even when it's running flat out. So I think Josh's complaint indicates that we have a problem with cost-delay tuning; hard to tell what exactly without more info. It might only be that the defaults are bad for these particular users, or it could be more involved. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers