Use of a supertype/subtype relationship is necessary when which of the following exists? Attributes apply to all of the instances of an entity type. An instance of a subtype participates in a relationship that is unique to that subtype. An instance of a subtype participates in a relationship that is the same as the other subtypes. No attributes apply to any of the instances of an entity type. TRUE ANSWER : ? YOUR ANSWER : ?
It is appropriate to use a supertype/subtype relationship when there are attributes that apply to some of the instances of an entity type. True False TRUE ANSWER : ? YOUR ANSWER : ?
Which one of the following symbols is not used in an ERD? Circle Diamond Oval Rectangle TRUE ANSWER : ? YOUR ANSWER : ?
A rectangle represents which of the following in an EER? Entity Optional One Relationship Attribute TRUE ANSWER : ? YOUR ANSWER : ?
An entity cluster is a set of one or more entity types and associated relationships. False True TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is not one of the three ways to classify an action assertion? Authorization Integrity Control Condition Enabler TRUE ANSWER : ? YOUR ANSWER : ?
A supertype/subtype hierarchy is which of the following? Each subtype has only one supertype. Each subtype has only one attribute. Each supertype has only one subtype. Each supertype has only one attribute. TRUE ANSWER : ? YOUR ANSWER : ?
If an entity adheres to the disjoint rule, then an entity instance can be a member of more than one entity for a given supertype. False True TRUE ANSWER : ? YOUR ANSWER : ?
A supertype/subtype hierarchy has which of the following features? Subtypes at the higher lever in the hierarchy inherit attributes only from their immediate subtype. Attributes are assigned at the highest logical level. Subtypes at the lower lever in the hierarchy inherit attributes only from their immediate supertype. Attributes are assigned at the lowest logical level. TRUE ANSWER : ? YOUR ANSWER : ?
An ERD that has had the entities clustered will display more entities. False True TRUE ANSWER : ? YOUR ANSWER : ?