Re: Default autovacuum settings too conservative

On Feb 1, 2006, at 4:37 PM, Matthew T. O'Connor wrote:

> As far I as I know, we are still looking for real world feedback.
> 8.1 is the first release to have the integrated autovacuum. The
> thresholds in 8.1 are a good bit less conservative than the
> thresholds in the contrib version. The contrib thresholds were
> universally considered WAY to conservative, but that was somewhat
> necessary since you couldn't set them on a per table basis as you
> can in 8.1. If we continue to hear from people that the current
> 8.1 default thresholds are still to conservative we can look into
> lowering them.

I spent the weekend researching and pondering this topic as well.

For me the per-table tuning is vital, since I have some tables that
are very small and implement a queue (ie, update very often several
million times per day and have at most 10 or so rows), some that are
fairly stable with O(10k) rows which update occasionally, and a
couple of tables that are quite large: 20 million rows which updates
a few million times per day and inserts a few thousand, and another
table with ~275 million rows in which we insert and update roughly 3
million per day.

The 40% overhead would kill these large tables both in terms of
performance and disk usage. I'm pondering a global 10% and having the
big tables at or below 1% based on the rate of change.

Is there a way to make the autovacuum process log more verbosely
while leaving the rest of the logging minimal? This would help tune it.