Re: PG 16 draft release notes ready - Mailing list pgsql-hackers

Hi,

Thanks for the release notes!

> <!--
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-06 [00d1e02be] hio: Use ExtendBufferedRelBy() to extend tables more eff
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-06 [26158b852] Use ExtendBufferedRelTo() in XLogReadBufferExtended()
> -->
> 
> <listitem>
> <para>
> Allow more efficient addition of multiple heap and index pages (Andres Freund)
> </para>
> </listitem>

While the case of extending by multiple pages improved the most, even
extending by a single page at a time got a good bit more scalable. Maybe just
"Improve efficiency of extending relations"?


I think:

> <!--
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-08 [0fdab27ad] Allow logical decoding on standbys
> -->
> 
> <listitem>
> <para>
> Allow logical decoding on standbys (Bertrand Drouvot, Andres Freund, Amit Khandekar)
> </para>
> </listitem>

pretty much includes:

> <!--
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-07 [be87200ef] Support invalidating replication slots due to horizon an
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-08 [26669757b] Handle logical slot conflicts on standby
> -->
> 
> <listitem>
> <para>
> Allow invalidation of replication slots due to row removal, wal_level, and conflicts (Bertrand Drouvot, Andres
Freund,Amit Khandekar)
 
> </para>

as it is a prerequisite.

I'd probably also merge

> <!--
> Author: Andres Freund <andres@anarazel.de>
> 2023-04-08 [0fdab27ad] Allow logical decoding on standbys
> -->
> 
> <listitem>
> <para>
> Add function pg_log_standby_snapshot() to force creation of a WAL snapshot (Bertrand Drouvot)
> </para>
> 
> <para>
> WAL snapshots are required for logical slot creation so this function speeds their creation on standbys.
> </para>
> </listitem>

As there really isn't a use case outside of logical decoding on a standby.


> <!--
> Author: Andres Freund <andres@anarazel.de>
> 2022-07-17 [089480c07] Default to hidden visibility for extension libraries whe
> Author: Andres Freund <andres@anarazel.de>
> 2022-07-17 [8cf64d35e] Mark all symbols exported from extension libraries PGDLL
> -->
> 
> <listitem>
> <para>
> Prevent extension libraries from export their symbols by default (Andres Freund, Tom Lane)
> </para>
> </listitem>

s/export/exporting/?


Looking through the release notes, I didn't see an entry for

commit c6e0fe1f2a08505544c410f613839664eea9eb21
Author: David Rowley <drowley@postgresql.org>
Date:   2022-08-29 17:15:00 +1200
 
    Improve performance of and reduce overheads of memory management

even though I think that's one of the more impactful improvements. What was
the reason for leaving that out?

Greetings,

Andres Freund