Re: postgres_fdw and skip locked

On Wed, Feb 16, 2022 at 8:38 PM Alexander Pyhalov
<a(dot)pyhalov(at)postgrespro(dot)ru> wrote:
>
> Ashutosh Bapat писал 2022-02-16 16:40:
> > On Mon, Feb 14, 2022 at 4:23 PM Alexander Pyhalov
> > <a(dot)pyhalov(at)postgrespro(dot)ru> wrote:
> >>
> >> Hi.
> >>
> >> Now select ... for update ... [skip locked|nowait] options are not
> >> pushed down to remote servers. I see the only reason is that we can
> >> speak to pre-9.5 server, which doesn't understand skip locked option.
> >> Are there any other possible issues? Should we add foreign table
> >> option
> >> to control this behavior?
> >
> > Should we always push these clauses if remote server's version is
> > newer than 9.5? There are quite a few options already. It will be good
> > not to add one more.
> >
> > I see that these options will work for all kinds of relations. So no
> > problem if foreign table is pointing to something other than a table.
>
> Hi.
> The issue is that we perform deparsing while planing, we haven't
> connected to server yet.
> Are there any ideas how to find out its version without specifying it,
> for example, in server options?

Yes, you are right. I wish foreign servers, esp. postgresql, could be
more integrated and if we could defer deparsing till execution phase.
But that's out of scope for this patch.

--
Best Wishes,
Ashutosh Bapat