Chapter 5

The property of subtype discriminator enables an entity supertype to inherit the attributes and relationships of the subtype.

• True

• False

Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype.

• True

• False

The relationships depicted within the specialization hierarchy are sometimes described in terms of "is-a" relationships.

• True

• False

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

• True

• False

One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their supertype.

• True

• False

Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype.

• True

• False

The "____" characteristic of a primary key states the following:
The PK should not have embedded semantic meaning. An attribute with embedded semantic meaning is probably better used as a descriptive characteristic of the entity rather than as an identifier.

• unique values

• nonintelligent

• preferably single-attribute

• security compliant

Overlapping subtypes are subtypes that contain a unique subset of the supertype entity set.

• True

• False

An entity supertype can have disjoint or overlapping entity subtypes.

• True

• False

Entity supertypes and subtypes are organized in a specialization hierarchy.

• True

• False