Sandro Dentella <sandro(dot)dentella(at)tin(dot)it> writes:
> I'd like to understand how should an editor cope with this case: I'd like
> to make tksql able to edit these tables too, but I see no way to act on a
> record in a unique way.
You should not be editing system catalogs with INSERT/UPDATE/DELETE
operations in any case.
This points up that the initdb process is pretty lax about marking
catalog columns NOT NULL, even though essentially all fixed-width
columns in the catalogs are in fact expected to not be null ...
regards, tom lane