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Subject: Re: eliminate xl_heap_visible to reduce WAL (and eventually set VM
 on-access)
From: Andrey Borodin <x4mmm@yandex-team.ru>
In-Reply-To: <CAAKRu_bwtBEzDwemyim1r6yYonw7FTyFr1HXG8vywCe-MdbPBQ@mail.gmail.com>
Date: Tue, 6 Jan 2026 14:40:03 +0500
Cc: Kirill Reshke <reshkekirill@gmail.com>,
 Chao Li <li.evan.chao@gmail.com>,
 Xuneng Zhou <xunengzhou@gmail.com>,
 Andres Freund <andres@anarazel.de>,
 Robert Haas <robertmhaas@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 Heikki Linnakangas <hlinnaka@iki.fi>
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To: Melanie Plageman <melanieplageman@gmail.com>
Archived-At: <https://www.postgresql.org/message-id/4379FDA3-9446-4E2C-9C15-32EFE8D4F31B%40yandex-team.ru>
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> On 6 Jan 2026, at 00:24, Melanie Plageman <melanieplageman@gmail.com> =
wrote:
>=20
> <v32-0014-Pass-down-information-on-table-modification-to-s.patch>

I've tried to take an attempt to review some patches of this patchset. =
It's huge and mostly polished.

In a step "Pass down information on table modification to scan node" you =
pass SO_HINT_REL_READ_ONLY flag in IndexNext() and =
BitmapTableScanSetup(), but not in IndexNextWithReorder() and =
IndexOnlyNext(). Is there a reason why index scans with ordering cannot =
use on-access VM setting?

Also, comment about visibilitymap_set() says "Callers that log VM =
changes separately should use visibilitymap_set()" as if =
visibilitymap_set() is some other function.


Best regards, Andrey Borodin.=