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.
