> which ultimately causes he Boolean expression to be false Strictly speaking, the boolean expression is also UNKNOWN ;-) I've tried to explain this here: http

> which ultimately causes he Boolean expression to be false Strictly speaking, the boolean expression is also UNKNOWN ;-) I've tried to explain this here: http://blog.jooq.org/2012/01/27/sql-incompatibilities-not-in-and-null-values/ http://blog.jooq.org/2012/01/27/sql-incompatibilities-not-in... ... but to this date, I'm still not 100% sure if I correctly understood SQL NULL. A quite worrying thing is documented here: http://blog.jooq.org/2012/12/24/row-value-expressions-and-the-null-predicate/ http://blog.jooq.org/2012/12/24/row-value-expressions-and-th... It's about row value expressions and NULL predicates. The following are not the same! (A, B) IS NOT NULL NOT((A, B) IS NULL) > I hope that redeems my reputation a little :-) You're forgiven ;-) Thanks!