Todd Vierling <tv@pobox.com> writes:
> Although I did find a SQL92 document on the web in the amount of time this
> took to copy back to me, and I see the clause about NULL <comp op>
> <anything> being unknown. Which, I imagine, means "implementation
> dependent".
No. It means unknown, ie, NULL. SQL's predicates are three-valued.
regards, tom lane