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