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 <[email protected]> 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 <[email protected]> > +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">§</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 <[email protected]> > 2025-11-18 [3edaf29fa] Rename two columns in pg_stat_subscription_stats. -- Bruce Momjian <[email protected]> https://momjian.us EDB https://enterprisedb.com Do not let urgent matters crowd out time for investment in the future.
