Re: Writable foreign tables: how to identify rows

On Wed, Mar 6, 2013 at 11:06 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Shigeru Hanada <shigeru(dot)hanada(at)gmail(dot)com> writes:
>> I'm not sure whether postgres_fdw should support, but updatable views
>> have no system column including ctid. So, we need magic identifier,
>> perhaps it would be set of primary key value(s), to support updating
>> remote updatable views via foreign tables.
>
> Yeah, I considered that. I thought seriously about proposing that we
> forget magic row identifiers altogether, and instead make postgres_fdw
> require a remote primary key for a foreign table to be updatable.

IMO, Utilizing anything but this for remote record identification is
an implementation specific optimization. Aren't the semantics
different though? If you go:

update foo set id = 1 where id = 1;

the primary key would not change, but the ctid would. or is that
already a handled?

merlin