Re: BUG #4648: needless deadlock on tables having foreign-key

Heikki Linnakangas  writes:
> Hmm, the comment specifically talks about deferrable RI checks. I wonder 
> if we could skip that when there's no deferred triggers queued?

The point of the comment is that if the FK isn't deferred then it will
have been executed already (at completion of the preceding INSERT).
I'd be a bit worried about relying on that, though, because of nested
query scenarios (eg, ON INSERT trigger fires an update on some
previously-inserted row) and the possibility of deferral status changing
intra-transaction.

			regards, tom lane