Re: why can't a table be part of the same publication as its schema

On 2022-Sep-20, Amit Kapila wrote:

> On Mon, Sep 19, 2022 at 8:46 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:

> > This seems a pretty arbitrary restriction. It feels like you're adding
> > this restriction precisely so that you don't have to write the code to
> > reject the ALTER .. SET SCHEMA if an incompatible configuration is
> > detected. But we already have such checks in several cases, so I don't
> > see why this one does not seem a good idea.
> >
> I agree that we have such checks at other places as well and one
> somewhat similar is in ATPrepChangePersistence().
>
> ATPrepChangePersistence()
> {
> ...
> ...
> /*
> * Check that the table is not part of any publication when changing to
> * UNLOGGED, as UNLOGGED tables can't be published.
> */

Right, I think this is a sensible approach.

> However, another angle to look at it is that we try to avoid adding
> restrictions in other DDL commands for defined publications.

Well, it makes sense to avoid restrictions wherever possible. But here,
the consequence is that you end up with a restriction in the publication
definition that is not very sensible. Imagine if you said "you can't
add schema S because it contains an unlogged table". It's absurd.

Maybe this can be relaxed in a future release, but it's quite odd.

> The intention was to be in sync with FOR ALL TABLES.

I guess we can change both (FOR ALL TABLES and IN SCHEMA) later.

--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/