PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> It is possible to break foreign key referential integrity when the FK
> columns have different types and updates are cascaded from the parent
> relation to the child relation.
I'm not really sure what you'd consider such an FK relationship to mean.
I can't get too excited about it when there doesn't seem to be a well
defined semantics for it.
regards, tom lane