Re: Enhance 'pg_createsubscriber' to retrieve databases automatically when no database is provided.

On Fri, Feb 21, 2025 at 5:18 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> On Thu, Feb 20, 2025 at 10:26 PM Hayato Kuroda (Fujitsu)
> <kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
> >
> > Dear Shubham,
> >
> > Thanks for updating the patch quickly!
> >
> > > > 04.
> > > > ```
> > > > +# Verify that only user databases got subscriptions (not template databases)
> > > > +my @user_dbs = ($db1, $db2);
> > > > +foreach my $dbname (@user_dbs)
> > > > +{
> > > > + my $sub_exists =
> > > > + $node_s1->safe_psql($dbname, "SELECT count(*) FROM
> > > pg_subscription;");
> > > > + is($sub_exists, '3', "Subscription created successfully for $dbname");
> > > > +}
> > > > ```
> > > >
> > > > Hmm, what do you want to check here? pg_subscription is a global catalog so
> > > that
> > > > very loop will see exactly the same content. Also, 'postgres' is also the user
> > > database.
> > > > I feel you must ensure that all three databases (postgres, $db1, and $db2) have
> > > a
> > > > subscription here.
> > > >
> > >
> > > Fixed.
> >
> > My point was that the loop does not have meaning because pg_subscription
> > is a global one. I and Peter considered changes like [1] is needed. It ensures
> > that each databases have a subscription.
> > Note: [1] cannot pass the test as-is because $db1 and $db2 contains special
> > characters. Please escape appropriately.
>
> Yes. Some test is still needed to confirm the expected subscriptions
> all get created for respective dbs. But, the current test loop just
> isn't doing it properly.
>
> >
> > Other comments are listed in below.
> >
> > 01.
> > ```
> > + <term><option>-a</option></term>
> > + <term><option>--all-dbs</option></term>
> > ```
> >
> > Peter's comment [2] does not say that option name should be changed.
> > The scope of his comment is only in the .c file.
>
> Yes, that's correct. My v9 suggestion to change 'all' to 'all_dbs' was
> referring only to the field name of struct CreateSubscriberOptions,
> nothing else. Not the usage help, not the error messages, not the
> docs, not the tests, not the commit message.

+1. We don't want yet another option to specify all databases. :)

--
Best Wishes,
Ashutosh Bapat