Re: First draft of PG 19 release notes

On Wed, Apr 15, 2026 at 10:59:13PM +0800, jian he wrote:
> On Wed, Apr 15, 2026 at 9:19 AM 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
> >
>
> https://git.postgresql.org/cgit/postgresql.git/commit/?id=ecd9288624a1582a732cf86ac5a01475a1ce7815

I don't usually mention test changes in the release notes.

> https://git.postgresql.org/cgit/postgresql.git/commit/?id=4edd6036d69ce42ac1af236f659f20daed65c8d4

Uh, the commit message is:

commit 4edd6036d69
Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Date: Tue Apr 7 14:45:33 2026 -0400

Fix WITHOUT OVERLAPS' interaction with domains.

UNIQUE/PRIMARY KEY ... WITHOUT OVERLAPS requires the no-overlap
column to be a range or multirange, but it should allow a domain
over such a type too. This requires minor adjustments in both
the parser and executor.

In passing, fix a nearby break-instead-of-continue thinko in
transformIndexConstraint. This had the effect of disabling
parse-time validation of the no-overlap column's type in the context
of ALTER TABLE ADD CONSTRAINT, if it follows a dropped column.
We'd still complain appropriately at runtime though.

Author: Jian He <jian(dot)universality(at)gmail(dot)com>
Reviewed-by: Paul A Jungwirth <pj(at)illuminatedcomputing(dot)com>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/CACJufxGoAmN_0iJ=hjTG0vGpOSOyy-vYyfE+-q0AWxrq2_p5XQ@mail.gmail.com
--> Backpatch-through: 18

Since it is backpatched to PG 18, it shouldn't appear in the PG 19
release notes.

> """
> Allow COPY TO to output partitioned tables (Jian He, Ajin Cherian) § §
> Previously COPY (SELECT ...) has to be used to output partitioned tables.
> """
> The second commit uses this feature, so i guess the commit message
> needs a slight change.

Updated in attached patch.

> """
> Improve timing performance measurements (Lukas Fittl, Andres Freund,
> David Geier, Lukas Fittl, David Geier) § §
> This benefits EXPLAIN (ANALYZE, TIMING) and pg_test_timing, and is
> controlled via server variable timing_clock_source.
> """
> Duplicated name entry.

Fixed in attached patch.

> """
> Allow IS [NOT] DISTINCT FROM NULL to be converted to IS [NOT] NULL for
> proven null arguments (Richard Guo) §
> The latter form is more easily optimized.
> """
> Two optional ``[NOT]`` introduce ambiguity.

Uh, if the NOT is in the first, it is in the second. Is that confusing?
Suggestions?

> """
> Add support for INSERT ... RETURNING ... ON CONFLICT DO SELECT
> (Andreas Karlsson, Marko Tiikkaja, Viktor Holmberg) §
> This allows conflicting rows to be returns, and optionally locked with
> FOR UPDATE/SHARE.
> """
> I think it's:
> INSERT... ON CONFLICT DO SELECT...RETURNING

Uh, went by the commit messsage which says:

The INSERT statement must have a RETURNING clause, when DO SELECT
is specified.

However, all the examples have the syntax as you specified, so I must
have interpreted it wrong.

Applied patch attached.

--
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.