Database:

For question #1-3 refer to the given Figure PRODUCT PK Prod Num Prod Title Prod_ReleaseDate Prod Price Prod Type d Prod_Type BOOK CD MOVIE PK,FK1 Prod Num PK,FK1 Prod Num PK,FK1 Prod Num Book CoverType Book PageCount CD Genre CD Artist Movie_Rating Movie Director 1. According to the data model, is it required that every entity instance in the PRODUCT table be associated with an entity instance in the CD table? Why or why not? 2. Is it possible for a book to appear in the BOOK table without appearing in the PRODUCT table? Why or why not? 3. What is a subtype discriminator? What is the possible value of subType discriminator