DATABASE SYSTEMS

Exercise 6.3 Describe the differences with examples between: - A category (a.k.a. union type) and a subclass that inherits from multiple superclasses - A category and a superclass with disjoint subclasses Exercise 6.4 Consider the following union type: Transform it (without loss of meaning!) into a diagram in which REGISTERED_VEHICLE is a superclass and CAR and TRUCK are its subclasses