Question 2-True or False (3 points) 1. The Not Null constraint states that no primary key - True -False value can be nul: 2. The project operation t is a commutative operation True - False 3. Every primary key of a relation is a superkey -True - False An example of a multivalued attribute is to determine the value of person Age by computing the stored date of birth attribute. 4. True - False 5. If a union type is total, the number of entities in the union type is equal to the total number of entities in all of its superclasses. -True - False 6. In an EER diagram, a specialization is a total disjoint specialization if every entity of the superclass is a member of exactly one subclass. - True - False