From: Bruce Momjian <bruce@momjian.us>
To: Melanie Plageman <melanieplageman@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@lists.postgresql.org>
Subject: Re: First draft of PG 19 release notes
Date: Wed, 15 Apr 2026 16:51:16 -0400
Message-ID: <ad_6RBwUlRooQK-9@momjian.us> (raw)
In-Reply-To: <CAAKRu_bzN6ioG+h7agjCF847whVpS2WEiJB3UXAtkJ3WVXOZwA@mail.gmail.com>
References: <ad7ngXC125AvNqC2@momjian.us>
<CAAKRu_bzN6ioG+h7agjCF847whVpS2WEiJB3UXAtkJ3WVXOZwA@mail.gmail.com>
On Wed, Apr 15, 2026 at 01:56:50PM -0400, Melanie Plageman wrote:
> On Tue, Apr 14, 2026 at 9:19 PM Bruce Momjian <bruce@momjian.us> wrote:
> >
> > I have completed the first draft of the PG 19 release notes:
> >
> > https://www.postgresql.org/docs/devel/release-19.html
>
> As of b46e1e54d078def, SELECT queries may update the visibility map.
> Previously only vacuum did this. I think users may be confused by this
> if it is not mentioned in the release notes.
Yes, I puzzled on this one and I am glad you clarified its purpose.
I think it should be added, and I have applied the attached patch.
> Additionally, users may notice that there are no longer
> XLOG_HEAP2_VISIBLE records. A series of commits culminating in
> a881cc9c7e819fb (others being d96f87332b378, add323da40a6bf9e0,
> 1252a4ee2863673, a759ced2f1e) moved VM setting into the
> XLOG_HEAP2_PRUNE_VACUUM_SCAN record. Users may notice that
> XLOG_HEAP2_VISIBLE records are no longer produced.
>
> This is more minor, but we also now (378a216187aea1) set pd_prune_xid
> on insert, so users may notice that a freshly inserted page is
> on-access pruned and then the VM is set (which wouldn't have happened
> before without vacuum).
Uh, I don't want to get into the internals too much in the release
notes, in fear of confusing/losing readers. I think this is too
low-level to mention, but we now have a good "prune" item so if they see
big improvements, they will know why.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
Attachments:
[text/x-diff] master.diff (840B, ../ad_6RBwUlRooQK-9@momjian.us/2-master.diff)
download | inline diff:diff --git a/doc/src/sgml/release-19.sgml b/doc/src/sgml/release-19.sgmlindex 2137621f6a6..6e038851a67 100644--- a/doc/src/sgml/release-19.sgml+++ b/doc/src/sgml/release-19.sgml@@ -596,6 +596,22 @@ New server variables are io_min_workers, io_max_workers, io_worker_idle_timeout,
</para>
</listitem>
+<!--+Author: Melanie Plageman <melanieplageman@gmail.com>+2026-03-30 [b46e1e54d] Allow on-access pruning to set pages all-visible+-->++<listitem>+<para>+Allow query table scans to mark pages as all-visible in the free space map (Melanie Plageman)+<ulink url="&commit_baseurl;b46e1e54d">§</ulink>+</para>++<para>+Previously only VACUUM and COPY FREEZE could this.+</para>+</listitem>+
<!--
Author: Masahiko Sawada <msawada@postgresql.org>
2026-04-06 [1ff3180ca] Allow autovacuum to use parallel vacuum workers.
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To: pgsql-hackers@postgresql.org
Cc: bruce@momjian.us, melanieplageman@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: First draft of PG 19 release notes
In-Reply-To: <ad_6RBwUlRooQK-9@momjian.us>
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