1Z0-006 Entity-Relationship Modeling 4

Question 1

In EER (Enhanced Entity-Relationship) modeling, 'specialization' is best defined as:

Accepted Answer

Defining subclasses of an entity type based on distinguishing characteristics

Answer

Specialization is a top-down process of defining subclasses from a superclass based on specific distinguishing features.

Question 2

What is 'generalization' in EER modeling?

Accepted Answer

Combining common attributes of multiple entity types into a higher-level superclass

Answer

Generalization is a bottom-up process where shared attributes of multiple entity types are abstracted into a common superclass.

Question 3

A 'disjoint' specialization constraint in EER means:

Accepted Answer

An entity instance can belong to at most one subclass at a time

Answer

A disjoint constraint (marked 'd' in EER diagrams) means the subclasses are mutually exclusive — an entity can be in only one subclass.

Question 4

In EER, an 'overlapping' specialization means:

Accepted Answer

An entity instance can simultaneously belong to more than one subclass

Answer

An overlapping constraint (marked 'o') allows an entity instance to be a member of multiple subclasses at the same time.

Question 5

Which of the following best describes 'total specialization'?

Accepted Answer

Every superclass instance must belong to at least one subclass

Answer

Total specialization (double line in EER) means every entity in the superclass must also be a member of at least one subclass.

(1Z0-006) Oracle Database Foundations Associate Practice Test