Re: TRUNCATE on foreign tables

2020年1月7日(火) 16:03 Michael Paquier <michael(at)paquier(dot)xyz>:
>
> On Mon, Jan 06, 2020 at 04:32:39PM -0500, Stephen Frost wrote:
> > RESTRICT, yes. I don't know about ONLY being sensible as we don't
> > really deal with inheritance and foreign tables very cleanly today, as I
> > said up-thread, so I'm not sure if we really want to put in the effort
> > that it'd require to figure out how to make ONLY make sense.
>
> True enough.
>
> > The question about how to handle IDENTITY is a good one. I suppose
> > we could just pass that down and let the FDW sort it out..?
>
> Looking at the code, ExecuteTruncateGuts() passes down restart_seqs,
> so it sounds sensible to me to just pass down that to the FDW
> callback and the callback decide what to do.
>
It looks to me the local sequences owned by a foreign table shall be restarted
by the core, regardless of relkind of the owner relation. So, even if FDW driver
is buggy, consistency of the local database is kept, right?
Indeed, "restart_seqs" flag is needed to propagate the behavior, however,
it shall be processed on the remote side via the secondary "TRUNCATE" command.
Is it so sensitive?

Best regards,
--
HeteroDB, Inc / The PG-Strom Project
KaiGai Kohei <kaigai(at)heterodb(dot)com>