Re: Autovacuum on by default?

Peter,

> OK, it seems that while everyone wants autovacuum be more aggressive by
> default, no one has any good data to support one setting or another. I
> so I suggest that we just cut scale factor and base threshold in half
> right now (so it'd be 0.2, 0.1, 500, 250) and see about a
> better-researched setting for the next release.

I'd recommend actually 0.4 and 0.2 and 200 and 100. I think that 20% and 10%
are too aggresive. 0.4 and 0.2 are what I've been using in production on
many machines. On the other hand, I think that the thresholds are much too
high -- that means that many small tables may never get vacuumed at all, even
after 100% row replacement.

I'll admit, however, that I don't have test data to support this.
Unfortunately we never got to good Autovac tests on the STP before it went
down.

--
Josh Berkus
PostgreSQL @ Sun
San Francisco