Re: BUG #18988: DROP SUBSCRIPTION locks not-yet-accessed database

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, Álvaro Herrera <alvherre@kurilemu.de>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, "exclusion@gmail.com" <exclusion@gmail.com>, "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
Date: 2025-08-15T06:21:47Z
Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix self-deadlock during DROP SUBSCRIPTION.

On Thu, Aug 14, 2025 at 5:04 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Thu, Aug 14, 2025 at 4:32 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> >
> > On Thu, Aug 14, 2025 at 2:18 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > > On Thu, Aug 14, 2025 at 2:05 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > > >
> > > > Yeah this looks fine to me.  PFA patches for back branches.
> > > >
> > >
> > > Can we add a test based on the scenario reported in this email?
> >
> > At first, I thought we can just add this test in subscription.sql, but
> > IMHO we should not do that because after testing DROP SUBSCRIPTION
> > give error we should eventually DROP the subscription for cleanup by
> > creating the slot and enabling the subscription (as shown below[1])
> > but I that realized during regression wal_level is not logical so we
> > are not allowed to create the logical slot.  So maybe we should write
> > it in 100_bugs.pl?  Am I missing something?
> >
>
> Another alternative is for cleanup instead of creating a missing slot
> we can just set the slot_name=NONE and then drop. I will move ahead
> with this approach.
>

Yeah, that sounds good to me.

-- 
With Regards,
Amit Kapila.