Enhanced_ERModel

Question 1

What is a Subtype?

Answer 1

it is a subgrouping of entities in an entity type

Question 2

What is a Supertype?

Answer 2

it is a generic entity type that is associated with one or more subtypes

Question 3

T or F: Attributes that are shared by all subtype entities are related to the supertype

Answer 3

True

Question 4

T or F: Attributes that are unique to a particular subtype are associated with that subtype

Answer 4

True

Question 5

What is Attribute Inheritance?

Answer 5

it is when a subtype inherits all the attributes and relationships of its supertype

Question 6

What is Generalization?

Answer 6

it is the process of defining a general entity type from a set of specialized entity types

NOTE: this is a bottom up process

Question 7

What is Specialization?

Answer 7

it is the direct reverse of generalization, and it is a top-down process

Question 8

What is Total Specialization?

Answer 8

it is when every instance of the supertype must be a member of some subtype

Question 9

What is Partial Specialization?

Answer 9

it is optional for every instance of the supertype to be a member of some subtype

Question 10

What is the Disjoint Rule?

Answer 10

if an entity instance of a supertype is a member of a subtype, it can not be a member of another subtype

Question 11

What is the Overlap Rule?

Answer 11

the entity instance of a supertype can be a member of two or more subtypes