"Marc G. Fournier" <scrappy@postgresql.org> writes:
> Now, what I want to do is add a FOREIGN KEY (again, I think) that when
> incident_summary.status is changed (either closed, or reopened), the
> associated records in incident_comments are changed to the same state ...
Why not just get rid of the status column in incident_comments, and
treat incident_summary.status as the sole copy of the state? When you
need to get to it from incident_comments, you do a join.
The foreign key you really ought to have here is from
incident_comments.incident_id to incident_summary.id
(assuming that I've understood your schema correctly).
regards, tom lane