Message-ID: <cee2e3e75cbfb4447fd30faeac159aef8ea6effc.camel@j-davis.com>
Subject: Re: Statistics Import and Export
From: Jeff Davis <pgsql@j-davis.com>
To: Corey Huinker <corey.huinker@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, 
 Michael Paquier <michael@paquier.xyz>, jian he
 <jian.universality@gmail.com>, Nathan Bossart <nathandbossart@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
Date: Tue, 25 Feb 2025 16:17:37 -0800
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On Tue, 2025-02-25 at 15:31 -0500, Corey Huinker wrote:
> Documentation:
>=20
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 The currently-supported relation statistics=
 are
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 <literal>relpages</literal> with a value of=
 type
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 <type>integer</type>, <literal>reltuples</l=
iteral> with a
> value of
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 type <type>real</type>, and
> <literal>relallvisible</literal> with a
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 value of type <type>integer</type>.
>=20
> Could we make this a bullet-list? Same for the required attribute
> stats and optional attribute stats. I think it would be more eye-
> catching and useful to people skimming to recall the name of a
> parameter, which is probably what most people will do after they've
> read it once to get the core concepts.

I couldn't make that look quite right. These functions are mostly for
use by pg_dump, and while documentation is necessary, I don't think we
should go so far as to make it "eye-catching". At least not until
things settle a bit.

> Question:
>=20
> Do we want to re-compact the oids we consumed in pg_proc.dat?

Done.

> Specifically missing are:
>=20
> * regclass not found
> * attribute is system column
> *=C2=A0scalars can't have mcelem
> *=C2=A0mcelem / mcelem freqs mismatch (parts 1 and 2)
> *=C2=A0scalars can't have elem_count_histogram
> *=C2=A0cannot set most_common_elems for range type

Done.

And committed.

Regards,
	Jeff Davis