On Mon, Jan 15, 2024 at 9:08 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> Pursuant to a comment I made a few months ago[1], I propose the attached
> changes to replication slots documentation. In essence, I want to
> explain that replication slots are good, and the max_size GUC, before
> moving on to explain that the other methods are worse.
>
> [1] https://postgr.es/m/20230413111838.e7yxke2dtwrxw3qy@alvherre.pgsql
Thanks for the patch. The wording looks good to me. However, I have
some comments on the placement of the note:
1. How about bundling this in a <note> </note> or <caution> </caution>?
+ <para>
+ Beware that replication slots can retain so many WAL segments that they
+ fill up the space allocated for <literal>pg_wal</literal>.
+ <xref linkend="guc-max-slot-wal-keep-size"/> can be used to limit the size
+ of WAL files retained by replication slots.
+ </para>
2. I think the better place for this note is at the end after the
"Similarly, <xref linkend="guc-hot-standby-feedback"/> on its own,
without" paragraph. It will then be like we introduce what replication
slot is and why it is better over other mechanisms to retain WAL and
then caution the users of it retaining WAL.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com