Re: foreign key locks, 2nd attempt

Noah Misch <noah@leadboat.com> writes:
> On Tue, Dec 13, 2011 at 06:36:21PM -0300, Alvaro Herrera wrote:
>> Yeah, I've been wondering about this: do we have a problem already with
>> exclusion constraints?  I mean, if a concurrent inserter doesn't see the
>> tuple that we've marked here as deleted while we toast it, it could
>> result in a violated constraint, right?  I haven't built a test case to
>> prove it.

> Does the enforcement code for exclusion constraints differ significantly from
> the ordinary unique constraint code?

It's an entirely separate code path (involving an AFTER trigger).  I
don't know if there's a problem, but Alvaro's right to worry that it
might behave differently.
        regards, tom lane