From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: VACUUM and ANALYZE disagreeing on what reltuples means
Date: Mon, 24 Jul 2017 18:55:45 -0400
Message-ID: <19990.1500936945@sss.pgh.pa.us> (raw)
In-Reply-To: <16db4468-edfa-830a-f921-39a50498e77e@2ndquadrant.com>
References: <16db4468-edfa-830a-f921-39a50498e77e@2ndquadrant.com>
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Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> It seems to me that VACUUM and ANALYZE somewhat disagree on what exactly
> reltuples means. VACUUM seems to be thinking that
> reltuples = live + dead
> while ANALYZE apparently believes that
> reltuples = live
> The question is - which of the reltuples definitions is the right one?
> I've always assumed that "reltuples = live + dead" but perhaps not?
I think the planner basically assumes that reltuples is the live tuple
count, so maybe we'd better change VACUUM to get in step.
regards, tom lane
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To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, tomas.vondra@2ndquadrant.com
Subject: Re: VACUUM and ANALYZE disagreeing on what reltuples means
In-Reply-To: <19990.1500936945@sss.pgh.pa.us>
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