Chapter 6, Problem 26E

Program Plan Intro

 Generalization or specialization hierarchy:

• The arrangement of higher-level supertypes entity and lower-level subtypes entity is called as generalization or specialization hierarchy.
• The specialization hierarchy is a “is-a” relationship model.
• It contains many levels of subtype or supertype relationships.
• Subtype is related to an entity supertype, where the supertype entity has common characteristics and the subtype entity has the unique characteristics of each entity subtype.