Date: Sat, 6 Jan 2018 17:59:42 -0500
From: Stephen Frost <sfrost@snowman.net>
To: Konstantin Knizhnik <k.knizhnik@postgrespro.ru>
Cc: Michael Paquier <michael.paquier@gmail.com>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Simon Riggs <simon@2ndquadrant.com>,
	Christoph Berg <myon@debian.org>,
	Thomas Munro <thomas.munro@enterprisedb.com>,
	Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] Surjective functional indexes
Message-ID: <20180106225942.GT2416@tamriel.snowman.net>
References: <aad81201-8788-a621-2001-537d843186fb@postgrespro.ru>
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Greetings,

* Konstantin Knizhnik (k.knizhnik@postgrespro.ru) wrote:
> On 15.12.2017 01:21, Michael Paquier wrote:
> >On Fri, Dec 15, 2017 at 6:15 AM, Alvaro Herrera <alvherre@alvh.no-ip.org=
> wrote:
> >>Konstantin Knizhnik wrote:
> >>>If you still thing that additional 16 bytes per relation in statistic =
is too
> >>>high overhead, then I will also remove autotune.
> >>I think it's pretty clear that these additional bytes are excessive.
> >The bar to add new fields in PgStat_TableCounts in very high, and one
> >attempt to tackle its scaling problems with many relations is here by
> >Horiguchi-san:
> >https://www.postgresql.org/message-id/20171211.201523.24172046.horiguchi=
=2Ekyotaro@lab.ntt.co.jp
> >His patch may be worth a look if you need more fields for your
> >feature. So it seems to me that the patch as currently presented has
> >close to zero chance to be committed as long as you keep your changes
> >to pgstat.c.
>=20
> Ok, looks like everybody think that autotune based on statistic is bad id=
ea.
> Attached please find patch without autotune.

This patch appears to apply with a reasonable amount of fuzz, builds,
and passes 'make check', at least, therefore I'm going to mark it
'Needs Review'.

I will note that the documentation doesn't currently build due to this:

/home/sfrost/git/pg/dev/cleanup/doc/src/sgml/ref/create_index.sgml:302: par=
ser error : Opening and ending tag mismatch: literal line 302 and unparseab=
le
    <term><literal>recheck_on_update</></term>

but I don't think it makes sense for that to stand in the way of someone
doing a review of the base patch.  Still, please do fix the
documentation build when you get a chance.

Thanks!

Stephen

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