Date: Mon, 26 Oct 2020 11:40:40 +0100
From: Dmitry Dolgov <9erthalion6@gmail.com>
To: Pavel Borisov <pashkin.elfe@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Teodor Sigaev <teodor@sigaev.ru>,
	Gavin Flower <GavinFlower@archidevsys.co.nz>,
	Andres Freund <andres@anarazel.de>,
	Michael Paquier <michael@paquier.xyz>,
	PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Subject: Re: POC: GROUP BY optimization
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> On Mon, Oct 26, 2020 at 01:28:59PM +0400, Pavel Borisov wrote:
> > Thanks for your interest! FYI there is a new thread about this topic [1]
> > with the next version of the patch and more commentaries (I've created
> > it for visibility purposes, but probably it also created some confusion,
> > sorry for that).
> >
> > Thanks!
>
> I made a very quick look at your updates and noticed that it is intended to
> be simple and some parts of the code are removed as they have little test
> coverage. I'd propose vice versa to increase test coverage to enjoy more
> precise cost calculation and probably partial grouping.
>
> Or maybe it's worth to benchmark both patches and then re-decide what we
> want more to have a more complicated or a simpler version.
>
> Good to know that this feature is not stuck anymore and we have more than
> one proposal.
> Thanks!

Just to clarify, the patch that I've posted in another thread mentioned
above is not an alternative proposal, but a development of the same
patch I had posted in this thread. As mentioned in [1], reduce of
functionality is an attempt to reduce the scope, and as soon as the base
functionality looks good enough it will be returned back.

[1]: https://www.postgresql.org/message-id/flat/CA%2Bq6zcW_4o2NC0zutLkOJPsFt80megSpX_dVRo6GK9PC-Jx_Ag%40mail.gmail.com