Re: First draft of the PG 15 release notes

On Wed, May 11, 2022 at 11:41 PM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> On Wed, May 11, 2022 at 04:02:31PM +0900, Amit Langote wrote:
> > On Wed, May 11, 2022 at 12:44 AM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > > I have completed the first draft of the PG 15 release notes
> > The commit is intended to only change the behavior of RI triggers,
> > while leaving user-defined triggers firing as before. I think it
> > might be a good idea to be specific by wording this, maybe as follows?
> >
> > Improve the firing of foreign key triggers during cross-partition
> > updates of partitioned tables (Amit Langote)
> >
> > Previously, such updates fired delete triggers on the source partition
> > and insert triggers on the target partition, whereas PostgreSQL will
> > now fire update triggers on the partitioned table mentioned in the
> > query, which makes the behavior of foreign keys pointing into that
> > table more consistent. Note that other user-defined triggers are
> > fired as they were before.
>
> Yes, this is what I needed to know. The updated text is:
>
> <!--
> Author: Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
> 2022-03-20 [ba9a7e392] Enforce foreign key correctly during cross-partition upd
> -->
>
> <listitem>
> <para>
> Improve foreign key behavior of updates on partitioned tables
> that move rows between partitions (Amit Langote)
> </para>
>
> <para>
> Previously, such updates ran delete actions on the source partition
> and insert actions on the target partition. PostgreSQL will now
> run update actions on the partition root.
> </para>
> </listitem>

Looks fine to me. Though I think maybe we should write the last
sentence as "PostgreSQL will now run update actions on the partition
root mentioned in the query" to be less ambiguous about which "root",
because it can also mean the actual root table in the partition tree.
A user may be updating only a particular subtree by mentioning that
subtree's root in the query, for example.

--
Thanks, Amit Langote
EDB: http://www.enterprisedb.com