Robert Haas <robertmhaas@gmail.com> writes:
> ... I think we should understand
> attoptions as things that modify the behavior of PostgreSQL, while
> attfdw/genoptions are there solely for the foreign data wrapper to
> use. An extra nullable field in pg_attribute isn't costing us
> anything non-trivial, and the syntactic and definitional clarity seems
> entirely worth it.
+1. We paid the price of allowing nullable columns in pg_attribute long
ago. One more isn't going to cost anything, especially since virtually
every row in that catalog already contains at least one null.
I'm not too thrilled with the terminology of "generic options", though.
I think this should be understood as specifically "FDW-owned options".
If the column isn't reserved for the use of the FDW, then you get right
back into the problem of who's allowed to use it and what if there's a
collision.
regards, tom lane