Re: pg_createsubscriber does not check output_plugin_libraries

On Tue, Sep 8, 2026 at 1:46 PM Ajin Cherian <itsajin(at)gmail(dot)com> wrote:
>
> On Mon, Sep 7, 2026 at 3:05 PM Hayato Kuroda (Fujitsu)
> <kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
> >
> > Dear hackers,
> >
> > I found the content was truncated. There might be an environment issue on my side.
> > PSA correct ones.

Thanks for updating the patches!

I did some further review.

The patched pg_createsubscriber seems to assume that the server
supports output_plugin_libraries. However, a user may run a newer
version of pg_createsubscriber against a server running an older minor
version that does not yet support output_plugin_libraries (e.g., v18.4).
So, for the v17 and v18 versions of pg_createsubscriber, it should handle
this case?

Previously, a non-superuser without permission to access
output_plugin_libraries could run pg_createsubscriber successfully.
But, with the patch, it fails with a permission denied error. I think
we should avoid this, for example by skipping the check when the user
doesn't have sufficient permission, rather than adding a new prerequisite
for running pg_createsubscriber. Thoughts?

+ /* Also check per-database settings on the publisher */
+ check_publisher_per_database(dbinfo);

In the v19 and v20 patches, this check is called from
check_publisher(), whereas in the v17 and v18 patches it is called from
check_subscriber(). Could you tell me why they are different?

Regards,

--
Fujii Masao