Design Approaches Entity Relationship Model(covered in this chapter) Models an enterprise as a collection of entities and relationships Entity:a“thing”or“object'”in the enterprise that is distinguishable from other objects -Described by a set of attributes Relationship:an association among several entities Represented diagrammatically by an entity-relationship diagram: Normalization Theory(Chapter 8) Formalize what designs are bad,and test for them Database System Concepts 7.5 @Silberschatz,Korth and SudarshanDatabase System Concepts 7.5 ©Silberschatz, Korth and Sudarshan Design Approaches Entity Relationship Model (covered in this chapter) Models an enterprise as a collection of entities and relationships  Entity: a “thing” or “object” in the enterprise that is distinguishable from other objects – Described by a set of attributes  Relationship: an association among several entities Represented diagrammatically by an entity-relationship diagram: Normalization Theory (Chapter 8) Formalize what designs are bad, and test for them