From: Joe Conway <mail@joeconway.com>
To: Don Seiler <don@seiler.us>
To: Phil Frost <phil@postmates.com>
Cc: pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: Why is my table not autovacuuming?
Date: Mon, 28 Aug 2017 09:13:03 -0700
Message-ID: <73557173-6cdb-6318-c7a5-e531d385e397@joeconway.com> (raw)
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On 08/28/2017 08:59 AM, Don Seiler wrote:
> So the autovacuum daemon knows that there are 71M rows, even though
> pg_stat_all_tables said only 170K? Is it using pg_class.reltuples? Is
> pg_stat_all_tables not really a reliable source of stats information?
See:
file:///opt/src/pgsql-git/master/src/backend/postmaster/autovacuum.c
* threshold = vac_base_thresh + vac_scale_factor * reltuples
pg_stat_all_tables only shows information known by the stats collector,
which only knows about activity since the last stats reset (which can
happen, for example on "immediate" shutdown or server crash), not
absolute numbers (although reltuples is only an estimate too).
--
Crunchy Data - http://crunchydata.com
PostgreSQL Support for Secure Enterprises
Consulting, Training, & Open Source Development
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To: pgsql-admin@postgresql.org
Cc: mail@joeconway.com, don@seiler.us, phil@postmates.com
Subject: Re: Why is my table not autovacuuming?
In-Reply-To: <73557173-6cdb-6318-c7a5-e531d385e397@joeconway.com>
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