Re: PG 13 release notes, first draft - Mailing list pgsql-hackers

On Thu, May 7, 2020 at 9:48 PM Bruce Momjian <bruce@momjian.us> wrote:
> On Thu, May  7, 2020 at 12:06:33AM +0900, Amit Langote wrote:
> > +Author: Etsuro Fujita <efujita@postgresql.org>
> > +2020-04-08 [c8434d64c] Allow partitionwise joins in more cases.
> > +Author: Tom Lane <tgl@sss.pgh.pa.us>
> > +2020-04-07 [981643dcd] Allow partitionwise join to handle nested FULL JOIN USIN
> > +-->
> > +
> > +<para>
> > +Allow partitionwise joins to happen in more cases (Ashutosh Bapat,
> > Etsuro Fujita, Amit Langote)
> > +</para>
> >
> > Maybe it would be better to break this into two items, because while
> > c8434d64c is significant new functionality that I only contributed a
> > few review comments towards, 981643dcd is relatively minor surgery of
>
> What text would we use for the new item?  I thought FULL JOIN was just
> another case that matched the description I had.

c8434d64c implements a new feature whereby, to use partitionwise join,
partition bounds of the tables being joined no longer have to match
exactly.  I think it might be better to mention this explicitly
because it enables partitionwise joins to be used in more partitioning
setups.

981643dcd fixes things so that 3-way and higher FULL JOINs can now be
performed partitionwise.  I am okay with even omitting this if it
doesn't sound big enough to be its own item.

> I think trying to put this all into one item is too complex, but I did
> merge two of the items together, so we have two items now:
>
>         <listitem>
>         <!--
>         Author: Peter Eisentraut <peter@eisentraut.org>
>         2020-03-10 [17b9e7f9f] Support adding partitioned tables to publication
>         Author: Peter Eisentraut <peter@eisentraut.org>
>         2020-04-08 [83fd4532a] Allow publishing partition changes via ancestors
>         -->
>
>         <para>
>         Allow partitioned tables to be replicated via publications (Amit Langote)
>         </para>
>
>         <para>
>         Previously, partitions had to be replicated individually.  Now
>         partitioned tables can be published explicitly causing all partitions
>         to be automatically published.  Addition/removal of partitions from
>         partitioned tables are automatically added/removed on subscribers.
>         The CREATE PUBLICATION option publish_via_partition_root controls whether
>         partitioned tables are published as themselves or their ancestors.
>         </para>

Thanks.  Sounds good except I think the last sentence should read:

...controls whether partition changes are published as their own or as
their ancestor's.

>         </listitem>
>
>         <listitem>
>         <!--
>         Author: Peter Eisentraut <peter@eisentraut.org>
>         2020-04-06 [f1ac27bfd] Add logical replication support to replicate into partit
>         -->
>
>         <para>
>         Allow non-partitioned tables to be logically replicated to subscribers
>         that receive the rows into partitioned tables (Amit Langote)
>         </para>

Hmm, why it make it sound like this works only if the source table is
non-partitioned?  The source table can be anything, a regular
non-partitioned table, or a partitioned one.

How about:

Allow logical replication into partitioned tables on subscribers

Previously, it was allowed only into regular [ non-partitioned ] tables.

--
Amit Langote
EnterpriseDB: http://www.enterprisedb.com