Re: FOREIGN TABLE and IDENTITY columns - Mailing list pgsql-hackers

From Julien Rouhaud
Subject Re: FOREIGN TABLE and IDENTITY columns
Date
Msg-id CAOBaU_YTGOQ2uVRhT_yctpgg+cGMi-Q=5Lqsw0ObrfO7psKMsw@mail.gmail.com
Whole thread Raw
In response to Re: FOREIGN TABLE and IDENTITY columns  (Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>)
List pgsql-hackers
On Wed, 9 Oct 2024, 21:22 Ashutosh Bapat, <ashutosh.bapat.oss@gmail.com> wrote:
On Wed, Oct 9, 2024 at 4:22 AM Julien Rouhaud <rjuju123@gmail.com> wrote:
>
> On Wed, Oct 9, 2024 at 12:40 AM Ashutosh Bapat
> <ashutosh.bapat.oss@gmail.com> wrote:
> >
> > On Tue, Oct 8, 2024 at 7:57 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> > >
> >
> > The rows inserted/udpated on the foreign server won't honour the local
> > IDENTITY constraint. Maybe that's why we don't want to support
> > identity column in foreign tables. If all it is expected to do is add
> > a monotonically increasing value, probably a DEFAULT value of
> > nextval() would suffice.
>
> What if there is no local IDENTITY constraint, is that an unsupported scenario?

Do you mean there's no local IDENTITY constraint but there's a remote
one?

yes. after all the identity clause is supposed to be the standard way to write it, and I don't see why having a relation only written through foreign table(s) wouldn't be that unacceptable. 

The documentation doesn't explicitly mention this. But it would
be good to test how that works, esp if somebody tries to INSERT a row
from local server with a value specified for an IDENTITY column.

I'm still waiting for an actual answer to whether the identity syntax is supposed to be supported or not. I don't really see the point wasting time testing that scenario and a bunch of others if someone shows up tomorrow to say it's a mistake and we should be explicitly forbidding it (especially since I won't be in front of a computer for a week or so). 

pgsql-hackers by date:

Previous
From: Ashutosh Bapat
Date:
Subject: Re: Inconsistent RestrictInfo serial numbers
Next
From: Pavel Stehule
Date:
Subject: Re: [PATCH] Add some documentation on how to call internal functions