A supertype can only have only one subtype.

A subtype discriminator of the supertype is an attribute whose values determine the target subtype(s).

A

True

B

False

A supertype/subtype hierarchy is which of the following?

A

Each subtype has only one attribute

B

Each supertype has only one attribute

C

Each subtype has only one supertype

D

Each supertype has only one subtype

Use of a supertype/subtype relationship is necessary when which of the following exists?

A

An instance of a subtype participates in a relationship that is unique to that subtype

B

An instance of a subtype participates in a relationship that is the same as the other subtypes

C

Attributes apply to all of the instances of an entity type

D

No attributes apply to any of the instances of an entity type

A supertype/subtype hierarchy has which of the following features?

A

Subtypes at the lower lever in the hierarchy inherit attributes only from their immediate supertype.

B

Subtypes at the higher lever in the hierarchy inherit attributes only from their immediate subtype.

C

Attributes are assigned at the highest logical level.

D

Attributes are assigned at the lowest logical level.

When mapping a supertype/subtype relationship which of the following is true?

A

The supertype primary key is assigned to each subtype.

B

The subtype primary key is assigned to each supertype.

C

There is no link between the supertype\/subtype entities.

D

There is no primary key\/foreign key relationship between a supertype\/subtype.

It is appropriate to use a supertype/subtype relationship when there are attributes that apply to some of the instances of an entity type.

A

True

B

False

A subtype entity is a special case of another entity called a supertype entity.

A

True

B

False

There is cardinality on an EER between the supertype and subtype.

A

True

B

False

An entity instance of a subtype represents the same entity instance of a supertype.

A

True

B

False

Total specialization is represented by double lines between the supertype and subtype on an EER.

A

True

B

False

A supertype can only have only one subtype.

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