Thom Brown <thom@linux.com> writes:
> So the ctid is always 2^32-1. Bit weird, but probably explainable.
See ItemPointerSetInvalid.
> But xmin on the file_fdw result is odd. Why are these all over the
> place?
heap_form_tuple initializes the t_choice fields as though for a tuple
Datum, and file_fdw doesn't change it.
Just a couple hours ago I was wondering why we create system columns for
foreign tables at all. Is there a reasonable prospect that they'll ever
be useful? I can see potential value in tableoid, but the others seem
pretty dubious --- even if you were fetching from a remote PG server,
the XIDs would not be meaningful within our own environment.
regards, tom lane