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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
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Comments: In-reply-to Tomas Vondra <tomas.vondra@2ndquadrant.com>
	message dated "Tue, 25 Jul 2017 00:47:36 +0200"
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Date: Mon, 24 Jul 2017 18:55:45 -0400
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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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