Re: [Patch] add new parameter to pg_replication_origin_session_setup

On Mon, Aug 12, 2024, at 3:43 PM, Doruk Yilmaz wrote:
> Hello all,

Hi!

> While working on our internal tools that utilise replication, we
> realised that a new parameter was added to the internal C function
> corresponding to pg_replication_origin_session_setup.
> However this parameter wasn't included in the user-facing API [1].

I'm curious about your use case. Is it just because the internal function has a
different signature or your tool is capable of apply logical replication changes
in parallel using the SQL API?

> I made this patch to the master which adds a way to control this
> parameter by adding a new version of the
> pg_replication_origin_session_setup function with user facing
> parameters 'text int4' in place of the current 'text' while keeping
> the existing variant
> (ensuring backwards compatibility). Could someone take a look at it?

I did a quick look at your patch and have a few suggestions.

* no documentation changes. Since the function you are changing has a new
signature, this change should be reflected in the documentation.
* no need for a new internal function. The second parameter (PID) can be
optional and defaults to 0 in this case. See how we changed the
pg_create_logical_replication_slot along the years add some IN parameters like
twophase and failover in the recent versions.
* add a CF entry [1] for this patch so we don't forget it. Another advantage is
that this patch is covered by CI [2][3].

[1] https://commitfest.postgresql.org/49/
[2] https://wiki.postgresql.org/wiki/Cfbot
[3] http://cfbot.cputube.org/index.html

--
Euler Taveira
EDB https://www.enterprisedb.com/