Re: [HACKERS] Shouldn't duplicate addition to publication be a no-op?

Amit Langote <Langote_Amit_f8@lab.ntt.co.jp> writes:
> I wonder if trying to add a relation to a publication that it is already a
> part should be considered a no-op, instead of causing an error (which
> happens in the ALTER PUBLICATION ADD TABLES case).

On what grounds?

The equivalent case for inheritance is an error:

regression=# create table foo (a int);
CREATE TABLE
regression=# create table bar () inherits (foo);
CREATE TABLE
regression=# alter table bar inherit foo;
ERROR:  relation "foo" would be inherited from more than once

(Your example purporting to show the contrary contains a typo.)

If there's a reason why this case should act differently from that
precedent, you haven't shown it.
        regards, tom lane