Content-Type: text/plain;
	charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3776.700.51.11.1\))
Subject: Re: Using Expanded Objects other than Arrays from plpgsql
From: Andrey Borodin <x4mmm@yandex-team.ru>
In-Reply-To: <3363452.1737483125@sss.pgh.pa.us>
Date: Sun, 26 Jan 2025 15:07:22 +0500
Cc: Michel Pelletier <pelletier.michel@gmail.com>,
 Pavel Stehule <pavel.stehule@gmail.com>,
 pgsql-hackers@lists.postgresql.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <0AC229FA-A3F1-43FD-B0DC-A46A73FEAFF7@yandex-team.ru>
References: <CACxu=vJaKFNsYxooSnW1wEgsAO5u_v1XYBacfVJ14wgJV_PYeg@mail.gmail.com>
 <1342498.1729444411@sss.pgh.pa.us>
 <CACxu=vLXvpzN4X3k+9jsMt6ujuOvFVUSkA80t_cROSsF4y2jQQ@mail.gmail.com>
 <1445998.1729482404@sss.pgh.pa.us>
 <CACxu=vKEF8Qa-OaADFxf0uMg-xw6gH_CNCWd2s+xaqh-gY4=xg@mail.gmail.com>
 <2062830.1729625620@sss.pgh.pa.us> <2265411.1729699470@sss.pgh.pa.us>
 <CACxu=v++HNmss59yGUDkRny7g=M8tZ2YXF07AUXqKVGqcSfxGQ@mail.gmail.com>
 <2354718.1729737539@sss.pgh.pa.us> <2581216.1729794746@sss.pgh.pa.us>
 <CACxu=v+dn37zr8gx5xNP-EZY3OLtGLTHrbx_ZkCQc40HpyMLKA@mail.gmail.com>
 <1948345.1730500073@sss.pgh.pa.us>
 <CACxu=vL7i_U_iSNpREe8eCAMEyKHuPpk9THRpBhk+ar0U1EdOw@mail.gmail.com>
 <CACxu=vKLc6f5N8_DR58LKkE1eohWSxTvThTeGsLm7p7QH1aFBA@mail.gmail.com>
 <CACxu=vJf2S=ysun_h=zmYNu6oUM47+egbpX5mMC0X9BJK=EQwQ@mail.gmail.com>
 <CACxu=vK+S6BXN8ZYyBvqQBWrcwHXqtue1-ZuKO3+XtHGBYcDUQ@mail.gmail.com>
 <CAFj8pRCd6xcH-AYEyHFdGdU89O9JjZ-v-pyQnOwd9zNJkCEdhQ@mail.gmail.com>
 <3797606.1732045516@sss.pgh.pa.us> <647219! .1736019347@sss.pgh.pa.us>
 <CACxu=vJ1UeXPjPOzfT2E=tFpSCxPxcB7hgfqHYmefJWh3ZXPew@mail.gmail.com>
 <1417389.1736964543@sss.pgh.pa.us>
 <CACxu=vKModwqSpEjpn-ur1uMAEYkcd-i8CvNsH-z9=dk7F7YQw@mail.gmail.com>
 <3363452.1737483125@sss.pgh.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/0AC229FA-A3F1-43FD-B0DC-A46A73FEAFF7%40yandex-team.ru>
Precedence: bulk

Hello everyone in this thread.

> On 21 Jan 2025, at 23:12, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>=20
> somebody will review this

I'm trying to dig into the patch set. My knowledge of the module is =
shallow and I hope to improve it by reading more patches in this area.

This patch set provides a new test, which runs just fine without the =
patch. But it's somewhat expected, such optimizations must be =
transparent for user...

And the coverage of newly invented mark_stmt() 42.37%. Some of branches =
are easy noops, but some are not.
I assume as a granted that we will not every get into infinite loop in a =
recursive call of mark_stmt().

expr_is_assignment_source() is named like if it should return nool, but =
it's void.

I could not grasp from reading the code one generic question about new =
optimization rule. What cost does checking for possible in-place update =
incurs to code cannot have this optimization? Is it =
O(numer_of_arguments) of for every assignment execution?

Thanks!


Best regards, Andrey Borodin.=