Re: [17] CREATE SUBSCRIPTION ... SERVER

On Mon, 2024-01-22 at 18:41 +0530, Ashutosh Bapat wrote:
> 0002 adds a prefix "regress_" to almost every object that is created
> in foreign_data.sql.

psql \dew outputs the owner, which in the case of a built-in FDW is the
bootstrap superuser, which is not a stable name. I used the prefix to
exclude the built-in FDW -- if you have a better suggestion, please let
me know. (Though reading below, we might not even want a built-in FDW.)

> Dummy FDW makes me nervous. The way it's written, it may grow into a
> full-fledged postgres_fdw and in the process might acquire the same
> concerns that postgres_fdw has today. But I will study the patches
> and
> discussion around it more carefully.

I introduced that based on this comment[1].

I also thought it fit with your previous suggestion to make it work
with postgres_fdw, but I suppose it's not required. We could just not
offer the built-in FDW, and expect users to either use postgres_fdw or
create their own dummy FDW.

> I enhanced the postgres_fdw TAP test to use foreign table. Please see
> the attached patch. It works as expected. Of course a follow-on work
> will require linking the local table and its replica on the publisher
> table so that push down will work on replicated tables. But the
> concept at least works with your changes. Thanks for that.

Thank you, I'll include it in the next patch set.

> I am not sure we need a full-fledged TAP test for testing
> subscription. I wouldn't object to it, but TAP tests are heavy. It
> should be possible to write the same test as a SQL test by creating
> two databases and switching between them. Do you think it's worth
> trying that way?

I'm not entirely sure what you mean here, but I am open to test
simplifications if you see an opportunity.

Regards,
Jeff Davis
>

[1]
https://www.postgresql.org/message-id/172273.1693403385%40sss.pgh.pa.us