Re: Another small bug (pg_autovacuum) - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Another small bug (pg_autovacuum)
Date
Msg-id 22509.1063386400@sss.pgh.pa.us
Whole thread Raw
In response to Re: Another small bug (pg_autovacuum)  ("Matthew T. O'Connor" <matthew@zeut.net>)
Responses Re: Another small bug (pg_autovacuum)  ("Matthew T. O'Connor" <matthew@zeut.net>)
List pgsql-hackers
"Matthew T. O'Connor" <matthew@zeut.net> writes:
> So we would have a problem if commands that effect these tables are done
> from lots of different databases.  In reality, I don't think these
> tables change that much (pg_database, pg_shadow, and pg_group), and most
> of commands that do effect these tables are usually done from template1.

I agree that there is probably not a large problem here.  I just wanted
to be sure that pg_autovacuum wouldn't go nuts if we can't fix pgstats
for 7.4.

> I can hardwire in something to hedge this off like setting the threshold
> for shared tables much much lower than normal thresholds.  I could also
> do something more complicated and try to aggregate all the activity seen
> by all the databases and when the sum exceeds the threshold then have
> then perform a vacuum from template1 and analyze from all other
> databases.

That seems like more work than it's worth for a short-term stopgap.

If Jan concludes that fixing pgstats is *really* hard and will not
happen for awhile, then we could talk about more extensive workarounds
in pg_autovacuum, but right now I doubt it's needed.
        regards, tom lane


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