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Exam 5: Data Modeling With the Entity-Relationship Model

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Question 31

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An attribute that determines which subtype should be used is a(n) ________.

A) supertype
B) subtype
C) discriminator
D) identifier

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Question 32

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The characteristics of a thing are described by its ________.

A) identifiers
B) entities
C) objects
D) attributes

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Question 33

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ID-dependent entities are associated by a nonidentifying relationship.

ID-dependent entities are a common type of weak entity.

An entity is something that users want to track.

An identifier of an entity instance is one or more attributes that name or identify entity instances.

An exclusive subtype pattern has one supertype entity that relates to one or more subtype entities.

Recursive relationships can have all of the following maximum cardinalities except ________.

Entities of a given type are grouped into entity classes.

E-R modeling recognizes both relationship classes and relationship instances.

To represent an archetype/instance pattern in an E-R model,________.

Entities with an IS-A relationship should have the same identifier.

What is an ID-Dependent entity? Include an example.

The notation 1:N shows a relationship's maximum cardinalities.

To represent an association pattern in an E-R model,________.

A weak entity is an entity that cannot exist in the database without (and is logically dependent upon)another type of entity also existing in the database.

You are given an E-R diagram with two entities,ORDER and CUSTOMER,as shown above,and are asked to draw the relationship between them.If a given customer can place many orders and a given order can be placed by at most one customer,which of the following should be indicated in the relationship symbol between the two entities?

A circle across the relationship line near an entity indicates ________.

How is maximum cardinality expressed in IE Crow's Foot E-R diagrams?

An entity that holds specialized attributes that distinguish it from one or more other similar entities is a ________.