Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Jul 19, 2013 at 12:58 PM, Rod Taylor <rod.taylor@gmail.com> wrote:
>> A poorly coded trigger on the referencing table has the ability to break
>> foreign keys, and as a result create a database which cannot be dumped and
>> reloaded.
> This is a known limitation of our foreign key machinery. It might
> well be susceptible to improvement, but I wouldn't count on anyone
> rewriting it in the near future.
If we failed to fire triggers on foreign-key actions, that would not be
an improvement. And trying to circumscribe the trigger's behavior so
that it couldn't break the FK would be (a) quite expensive, and
(b) subject to the halting problem, unless perhaps you circumscribed
it so narrowly as to break a lot of useful trigger behaviors. Thus,
there's basically no alternative that's better than "so don't do that".
regards, tom lane