From: Tom Lane <tgl@sss.pgh.pa.us>
To: Artur Zając <azajac@ang.com.pl>
Cc: pgsql-performance@postgresql.org
Subject: Re: Planner estimates and VACUUM/autovacuum
Date: Mon, 03 Feb 2014 16:03:32 -0500
Message-ID: <17918.1391461412@sss.pgh.pa.us> (raw)
In-Reply-To: <036301cf2116$44b73c10$ce25b430$@ang.com.pl>
References: <036301cf2116$44b73c10$ce25b430$@ang.com.pl>
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=?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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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, azajac@ang.com.pl
Subject: Re: Planner estimates and VACUUM/autovacuum
In-Reply-To: <17918.1391461412@sss.pgh.pa.us>
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