"Albe Laurenz" <laurenz.albe@wien.gv.at> writes:
> Tom Lane wrote:
>> Instead, the planner arranges for the TID to be carried up as an
>> explicit resjunk column named ctid. (Currently this is done in
>> rewriteTargetListUD(), but see also preptlist.c which does some
>> related things for SELECT FOR UPDATE.)
>>
>> I'm inclined to think that what we need here is for FDWs to be able to
>> modify the details of that behavior, at least to the extent of being
>> able to specify a different data type than TID for the row
>> identification column.
> Would that imply inventing a new system attribute for
> "foreign tid"?
No, I think you missed the point of what I wrote completely. The target
row ID is not treated as a system attribute during UPDATE/DELETE. It's
an ordinary data column that's silently added to what the user wrote.
regards, tom lane