Re: archive modules

On Tue, Nov 2, 2021 at 1:24 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
> It seems to me that this patch is not moving into the right direction
> implementation-wise (I have read the arguments about
> backward-compatibility that led to the introduction of archive_library
> and its shell mode), for what looks like a duplicate of
> shared_preload_libraries but for an extra code path dedicated to the
> archiver, where we could just have a hook instead? We have been
> talking for some time now to make the archiver process more
> bgworker-ish, so as we finish with something closer to what the
> logical replication launcher is.

Why in the world would you want a plain hook rather than something
closer to the way logical replication works?

Plain hooks are annoying to use. If you load things at the wrong time,
it silently doesn't work. It's also impossible to unload anything. If
you want to change to a different module, you probably have to bounce
the whole server instead of just changing the GUC and letting it load
the new module when you run 'pg_ctl reload'.

Blech! :-)

--
Robert Haas
EDB: http://www.enterprisedb.com