Ah, you have to add it as a 'unique' table constraint, if you add a unique index it doesn't work. Odd, shouldn't you be able to do it either way?SQL spec defines behavior of unique constrain over null able field to allow multiple
null for the fields participating in the constraint.For Index it doesn't specifically says anything about it. So for now even though the index and constraint are behaving differently the behavior is not violating any guidelines.
anurag
