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From: Hari Krishna Sunder <hari.db.pg@gmail.com>
Date: Tue, 20 May 2025 10:32:39 -0700
Message-ID: 
 <CAAeiqZ0jqtJaigLa6WDAskRFM4gDCj3hNxmwiWs+wHU0gxCTKQ@mail.gmail.com>
Subject: Re: Statistics Import and Export
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Corey Huinker <corey.huinker@gmail.com>, Jeff Davis <pgsql@j-davis.com>,
	Robert Treat <rob@xzilla.net>, Robert Haas <robertmhaas@gmail.com>,
	Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>,
	Michael Paquier <michael@paquier.xyz>, jian he <jian.universality@gmail.com>,
	Bruce Momjian <bruce@momjian.us>,
 Matthias van de Meent <boekewurm+postgres@gmail.com>,
	Magnus Hagander <magnus@hagander.net>, Stephen Frost <sfrost@snowman.net>,
	Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>,
 Peter Smith <smithpb2250@gmail.com>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 alvherre@alvh.no-ip.org
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Ah ya, forgot that reltuples are not always accurate. This sounds
reasonable to me.

On Mon, May 19, 2025 at 2:32=E2=80=AFPM Nathan Bossart <nathandbossart@gmai=
l.com>
wrote:

> On Mon, May 19, 2025 at 02:13:45PM -0700, Hari Krishna Sunder wrote:
> > I think it would be better to revert 9879105 since there can be a
> > considerable number of true empty tables that we don=C2=B4t need to pro=
cess.
>
> I'm not sure that's a use-case we really need to optimize.  Even with
> 100,000 empty tables, "vacuumdb --analyze-only --missing-stats-only --job=
s
> 64" completes in ~5.5 seconds on my laptop.  Plus, even if reltuples is 0=
,
> there might actually be rows in the table, in which case analyzing it wil=
l
> produce rows in pg_statistic.
>
> --
> nathan
>

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<div dir=3D"ltr">Ah ya, forgot that reltuples=C2=A0are not always accurate.=
 This sounds reasonable to me.=C2=A0</div><br><div class=3D"gmail_quote gma=
il_quote_container"><div dir=3D"ltr" class=3D"gmail_attr">On Mon, May 19, 2=
025 at 2:32=E2=80=AFPM Nathan Bossart &lt;<a href=3D"mailto:nathandbossart@=
gmail.com">nathandbossart@gmail.com</a>&gt; wrote:<br></div><blockquote cla=
ss=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid =
rgb(204,204,204);padding-left:1ex">On Mon, May 19, 2025 at 02:13:45PM -0700=
, Hari Krishna Sunder wrote:<br>
&gt; I think it would be better to revert 9879105 since there can be a<br>
&gt; considerable number of true empty tables that we don=C2=B4t need to pr=
ocess.<br>
<br>
I&#39;m not sure that&#39;s a use-case we really need to optimize.=C2=A0 Ev=
en with<br>
100,000 empty tables, &quot;vacuumdb --analyze-only --missing-stats-only --=
jobs<br>
64&quot; completes in ~5.5 seconds on my laptop.=C2=A0 Plus, even if reltup=
les is 0,<br>
there might actually be rows in the table, in which case analyzing it will<=
br>
produce rows in pg_statistic.<br>
<br>
-- <br>
nathan<br>
</blockquote></div>

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