Exam 5: Data Modeling With the Entity-Relationship Model

Which of the following is not a good reason for designing a data model?

Which of the following is not true about subtype entities?

An identifier serves the same role for a table that a key does for an entity.

A composite attribute is an attribute that ________.

The degree of a relationship is expressed as the relationship's maximum cardinality.

An identifier of an entity instance must consist of one and only one attribute.

A single relationship class involves only one entity class.

A relationship's maximum cardinality indicates the maximum number of entities that can participate in the relationship.

E-R models use an identifying relationship to connect entities that are ID-dependent.

An entity instance is an occurrence of a particular entity.

When designing a database,first identify the entities,then determine the attributes,and finally create the relationships.

A binary relationship is a relationship based on numerical entity instance identifiers.

In E-R modeling,entities within an entity class may have different attributes.

Distinguish between entity identifiers and keys.

In a minimum cardinality,minimums are generally stated as ________.

For a relationship to be considered a binary relationship it must satisfy which of the following conditions?

Relationships between supertypes and subtypes are called IS-A relationships.

An entity that represents something that can exist on its own is called a strong entity.

The principal difference between an entity and a table is that you can express a relationship between entities without using foreign keys.

Entities containing multivalued attributes are often represented using subtypes.