Re: Planner estimates and VACUUM/autovacuum - Mailing list pgsql-performance

From Tom Lane
Subject Re: Planner estimates and VACUUM/autovacuum
Date
Msg-id 17918.1391461412@sss.pgh.pa.us
Whole thread Raw
In response to Planner estimates and VACUUM/autovacuum  (Artur Zając <azajac@ang.com.pl>)
List pgsql-performance
=?iso-8859-2?Q?Artur_Zaj=B1c?= <azajac@ang.com.pl> writes:
> That is strange for me. VACUUM updates pg_class.reltuples differently (only
> live roiws count) than autovacuum (live and dead rows). Why?

I don't have time to poke into this in detail right now, but I think
that more likely the issue is that ANALYZE might have a different rule
than VACUUM.  autovacuum will fire those operations independently, which
doesn't match what you're doing by hand.

Which is not to say that we shouldn't think about fixing that, but that
it's important to understand the problem clearly first.

            regards, tom lane


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