Horton

Re: PG 16 draft release notes ready

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Erwin Brandstetter <brsaweda@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-08-22T05:36:34Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Revert MAINTAIN privilege and pg_maintain predefined role.

  2. doc: PG 16 relnotes, remove "Have initdb use ICU by default"

  3. initdb: change default --locale-provider back to libc.

  4. doc: PG 16 relnotes, add author

  5. doc: PG 16 relnotes, move memory item and reword OUTER item

  6. doc: PG 16 relnotes, add memory overhead reduction item

  7. doc: PG 16 relnotes, adjust subscription origin mention

  8. doc: PG 16 relnotes, adjust auto_explain logging item

  9. doc: PG 16 relnotes: adjust outer/full hash join parallelization

  10. doc: PG 16 relnotes, fix duplicate author and commit

  11. doc: PG 16 relnotes, fix "locale" typo and windows locale text

  12. doc: PG 16 relnotes, add author from previous merge

  13. doc: PG 16 relnotes, wording adjustments

  14. doc: PG 16 relnotes, merge and move vector items

  15. doc: PG 16 relnotes, update xid/subxid searches item

  16. doc: PG 16 relnotes, SIMD improvements

  17. doc: PG 16 relnotes, add major features list

  18. doc: PG 16 relnotes, misc merged items and bootstrap detail

  19. doc: PG 16 relnotes, misc. updates

  20. doc: PG 16 relnotes, add commits

  21. Allow logical decoding on standbys

  22. Fix ts_headline() edge cases for empty query and empty search text.

  23. Add a hook for modifying the ldapbind password

  24. Rework design of functions in pg_walinspect

  25. initdb: derive encoding from locale for ICU; similar to libc.

  26. Doc: add XML ID attributes to <sectN> and <varlistentry> tags.

  27. Simplify the implementations of the to_reg* functions.

  28. Rename pg_dissect_walfile_name() to pg_split_walfile_name()

  29. Make materialized views participate in predicate locking

  30. Improve performance of and reduce overheads of memory management

  31. Allow grant-level control of role inheritance behavior.

On Tue, 22 Aug 2023 at 10:08, Bruce Momjian <bruce@momjian.us> wrote:
>
> On Sat, Aug 19, 2023 at 04:24:48AM +0200, Erwin Brandstetter wrote:
> > I posted to pgsql-docs first, but was kindly redirected here by Jonathan:
> >
> > The release notes for Postgres 16 says here:
> > https://www.postgresql.org/docs/16/release-16.html#RELEASE-16-PERFORMANCE
> >
> > Same as here:
> > https://momjian.us/pgsql_docs/release-16.html#RELEASE-16-PERFORMANCE
> >
> >     Allow window functions to use ROWS mode internally when RANGE mode is
> > specified but unnecessary (David Rowley)
>
> Yes, I didn't like "specified" myself but never returned to improve it.
> I am now using:
>
>         Allow window functions to use the faster <link
>         linkend="syntax-window-functions"><literal>ROWS</literal></link> mode
>         internally when <literal>RANGE</literal> mode is active but unnecessary
>                                                          ------
>         (David Rowley)
>
> Can that be improved?

Looks good to me.

> > Also, I was hoping to be mentioned in the release note for working this out:
> >
> >     Allow window functions to use the faster ROWS mode internally when RANGE
> > mode is specified or would be default, but unnecessary (David Rowley, Erwin
> > Brandstetter)
>
> Uh, I have CC'ed David Rowley because that is unclear based on the
> commit message.  I don't normally mention reviewers.

I confirm that Erwin reported in [1] that row_number() is not affected
by the ROWS/RANGE option and that ROWS performs better due to the
executor having less work to do.  I am the author of the patch which
implemented that plus a few other window functions that also can
benefit from the same optimisation.  Based on this, I don't see any
problems with the credits for this item as they are currently in the
release notes.

David

[1] https://postgr.es/m/CAGHENJ7LBBszxS%2BSkWWFVnBmOT2oVsBhDMB1DFrgerCeYa_DyA%40mail.gmail.com