Enhanced ER Model Quiz

What does the EER model build upon?

• Object-Oriented Model

• Traditional Entity-Relationship Model

• Relational Model

• Hierarchical Model

What is a supertype?

• A specialized entity

• A generic entity

• An abstract class

• A concrete entity

What do subtypes inherit from their supertypes?

• All attributes

• Only attributes

• Only relationships

• No attributes

What is the process of combining specialized entities into a more generic entity called?

• Classification

• Specialization

• Generalization

• Aggregation

What does the Total Specialization Rule require?

• Some instances can exist without subtypes

• Instances can belong to multiple subtypes

• No instances can belong to subtypes

• Every instance must belong to at least one subtype

What does the Disjoint Rule state?

• An instance can belong to multiple subtypes

• An instance can belong to only one subtype

• An instance cannot belong to any subtype

• An instance can belong to all subtypes

What is the purpose of entity clusters in EER diagrams?

• To add more entities

• To simplify complex structures

• To eliminate relationships

• To increase complexity

Answer explanation

improve readability and reduce clutter

What is symbol for Disjointness Constraint: Disjoint: text in the circumcence

• Dis

• D

• d

• O

What is specialization used for?

• To divide a supertype into subtypes

• To define common attributes

• To create new entities

• To combine entities

Answer explanation

Process to define supertype

Generalization (Bottum-up): combine specialized entities to generic entities

Specialization(Top-Down): divide to distinguish attributes or roles.

Which rule allows instances to exist without being part of any subtype?

• Total Specialization Rule

• Partial Specialization Rule

• Overlap Rule

• Disjoint Rule