Re: POC: enable logical decoding when wal_level = 'replica' without a server restart

On Thu, Sep 25, 2025 at 4:57 AM shveta malik <shveta(dot)malik(at)gmail(dot)com> wrote:
>
> On Tue, Sep 23, 2025 at 3:28 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> >
> > I've attached the updated patch. It incorporates all comments I got so
> > far and implements to lazily disable logical decoding. It's used only
> > when the process tries to disable logical decoding during process
> > exit.
> >
>
> I am resuming the review now. I agree with the discussion of lazily
> disabling logical decoding on ERROR or process-exit for temp-slot.
>
> Few initial comments:

Thank you for the comments!

>
> 1)
> I see that on standby too, during proc-exit, we set 'pending_disable'.
> But it never resets it, as DisableLogicalDecodingIfNecessary is no-op
> on standby. And thus the checkpoint keeps on attempting to reset it
> everytime. Do we even need to set it on standby?
>
> Logfile has repeated: 'start completing pending logical decoding
> disable request'

Ugh, I missed that part. I think that standbys should not delegate the
deactivation to the checkpointer uless the deactivation is actually
required.

> 2)
> + ereport(LOG,
> + (errmsg("skip disabling logical decoding as during process exit")));
>
> 'as' not needed.

I've fixed the above two points and attached the new version patch.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com