Re: BUG #13978: xmin,xmax not current for foreign table - Mailing list pgsql-bugs

digoal@126.com writes:
> tbl0 is a foreign table with postgres_fdw
> master=# select tableoid,ctid,xmin,xmax,* from tbl0;
> ...
> but the right values is:

xmin/xmax are not meaningful in foreign tables.  Even in the case of a
postgres_fdw foreign table, they cannot be useful because there's no way
to map between the remote server's XID numbering and local XIDs.  So I do
not believe your claim that there's a "right" value for them to have.

Ideally, those columns wouldn't even exist in foreign tables; but fixing
that has so far not seemed worth the trouble it would require.

            regards, tom lane