Alban Hertroys <alban(at)magproductions(dot)nl> writes:
> I suspect they have some pretty good reasons to treat NULL values in a
> UNIQUE constraint as different even from other NULL values. It sure
> makes me curious though ;)
Date & Darwen make it pretty clear that they think this sucks, and in
fact that they think SQL's definition of nulls sucks in general. But
that's how the spec is written.
regards, tom lane