Re: First draft of PG 19 release notes

I will review this and hopefully apply it on Friday.

---------------------------------------------------------------------------

On Mon, Nov 2, 2026 at 01:42:44PM -0800, Masahiko Sawada wrote:
> Hi Bruce,
>
> On Tue, Apr 14, 2026 at 6:19 PM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> >
> > I have completed the first draft of the PG 19 release notes:
> >
> > https://www.postgresql.org/docs/devel/release-19.html
> >
> > The feature count is 212. The recent average is 200:
> >
> > https://momjian.us/main/writings/pgsql/missing.pdf#page=3
> >
> > I will create a wiki page to explain my methods used to create this
> > because, someday, someone else will need to do this.
> >
> > I am traveling April 19 to May 7, so I might not be able to make quick
> > adjustments based on feedback. Another committer can handle them, or
> > you can wait for me to get to it.
>
> I've pushed a fix (8628df8891a) for how parallel vacuum computes the
> cost-based vacuum delay. As I mentioned in the commit message, while
> the fix corrects the delay computation, it could make VACUUM with the
> PARALLEL option and cost-based delay enabled slower after upgrading to
> v19. I think it's worth mentioning this in the release notes so that
> users can re-tune the cost-based delay parameters. I've attached the
> patch to add the item to the "Migration to Version 19" section. Please
> review it.
>
> Regards,
>
> --
> Masahiko Sawada
> Amazon Web Services: https://aws.amazon.com

> diff --git a/doc/src/sgml/release-19.sgml b/doc/src/sgml/release-19.sgml
> index 253fa07179a..7939d44aa36 100644
> --- a/doc/src/sgml/release-19.sgml
> +++ b/doc/src/sgml/release-19.sgml
> @@ -303,6 +303,22 @@ large analytical queries to manually enable <acronym>JIT</acronym>.
> </para>
> </listitem>
>
> +<!--
> +Author: Masahiko Sawada <msawada(at)postgresql(dot)org>
> +2026-11-02 [8628df889] Make parallel vacuum processes share the cost limit.
> +-->
> +
> +<listitem>
> +<para>
> +Make the leader and workers of a <link linkend="parallel-vacuum">parallel vacuum</link> share the cost-based vacuum delay limit (Bharath Rupireddy)
> +<ulink url="&commit_baseurl;8628df889">&sect;</ulink>
> +</para>
> +
> +<para>
> +Previously each process slept based only on the cost it incurred itself, so a parallel vacuum could consume several times the budget set by <link linkend="guc-vacuum-cost-limit"><varname>vacuum_cost_limit</varname></link>. As a result, <link linkend="sql-vacuum"><command>VACUUM</command></link> with parallel workers and cost-based delay enabled can run slower than in previous releases.
> +</para>
> +</listitem>
> +
> <!--
> Author: Amit Kapila <akapila(at)postgresql(dot)org>
> 2025-11-18 [3edaf29fa] Rename two columns in pg_stat_subscription_stats.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Do not let urgent matters crowd out time for investment in the future.