MATERIALIZATION

A new data abstraction, called Materialization, is introduced to model a situation that occurs frequently in the real world and has importan t implications for database design. Materialization is the relationshi p between two entity types, one that represents a conceptual object, f or example, a TV Model, and one that represents its corresponding conc rete objects, in this case, actual TV Sets. The materialization constr uct is formally defined and contrasted with other well-known data abst ractions. Its design implications are presented in terms of the entity -relationship model and its translation into a relational model. Guide lines are offered for the proper employment of this relationship in da tabase design methodologies, and a discussion is provided of why this constitutes an important data modeling construct.