Question 1

In an E-R model,the three types of maximum cardinality are 1:1,1:N and N:M.

Accepted Answer

A) True 
 B)False

Question 2

Maximum cardinality refers to ________.

Accepted Answer

A)  the most instances of one entity class that can be involved in a relationship instance with another entity class
B)  the minimum number of entity classes involved in a relationship
C)  whether or not an instance of one entity class is required to be related to an instance of another entity class
D)  whether or not an entity is a weak entity
E)  None of the above.

Question 3

Discriminators can be ________.

Accepted Answer

A)  exclusive only
B)  inclusive only
C)  decisive only
D)  A or B
E)  B or C

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

Which of the following is not true about subtype entities?

Accepted Answer

A)  Subtypes may be exclusive.
B)  The supertype and subtypes will have the same identifier.
C)  Subtypes are used to avoid a situation in which some attributes are required to be null.
D)  Subtypes have attributes that are required by the supertype.
E)  Subtypes can produce a closer-fitting data model.

Question 6

When an entity has a relationship to itself,we have a(n) ________.

Accepted Answer

A)  supertype/subtype relationship
B)  archetype/instance relationship
C)  recursive relationship
D)  A or C
E)  B or C

Question 7

The method of constructing data models used in the text is the extended entity-relationship (E-R)model.

Accepted Answer

A) True 
 B)False

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

In a 1:N relationship,the term parent refers to the N side of the relationship.

Accepted Answer

A) True 
 B)False

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

A composite identifier is defined as a composite attribute that is an identifier.

Accepted Answer

A) True 
 B)False

Question 12

An entity whose existence depends on the presence of another entity,but whose identifier does not include the identifier of the other entity is a(n) ________.

Accepted Answer

A)  strong entity
B)  weak entity
C)  ID-dependent entity
D)  A and C
E)  B and C

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

In E-R modeling,an attribute describes the characteristics of an entity.

Accepted Answer

A) True 
 B)False

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

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

Accepted Answer

A)  a maximum cardinality of "zero"
B)  a maximum cardinality of "one"
C)  a minimum cardinality of "optional"
D)  a minimum cardinality of "required"
E)  None of the above.

Question 17

-You are given an E-R diagram with two entities,ORDER and CUSTOMER,as shown above.What does the symbol next to the CUSTOMER entity indicate?

Accepted Answer

A)  A maximum cardinality of "zero"
B)  A maximum cardinality of "one"
C)  A minimum cardinality of "optional"
D)  A minimum cardinality of "required"
E)  None of the above.

Question 18

Data modelers agree that weak,non-ID-dependent entities exist and are important.

Accepted Answer

A) True 
 B)False

Question 19

The characteristics of a thing are described by its ________.

Accepted Answer

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

Question 20

Recursive relationships can have which of the following maximum cardinalities?

Accepted Answer

A)  1:1
B)  1:N
C)  N:M
D)  A or B
E)  A,B or C

Exam 5: Data Modeling With the Entity-Relationship Model

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

Correct AnswerverifiedShow Answer

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

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A composite identifier is defined as a composite attribute that is an identifier.

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

Correct AnswerverifiedShow Answer

Discriminators can be ________.

Correct AnswerverifiedShow Answer

Which of the following is not true about subtype entities?

Correct AnswerverifiedShow Answer

In an E-R model,the three types of maximum cardinality are 1:1,1:N and N:M.

Correct AnswerverifiedShow Answer

The method of constructing data models used in the text is the extended entity-relationship (E-R)model.

Correct AnswerverifiedShow Answer

An entity whose existence depends on the presence of another entity,but whose identifier does not include the identifier of the other entity is a(n) ________.

Correct AnswerverifiedShow Answer

Recursive relationships can have which of the following maximum cardinalities?

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

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

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

Correct AnswerverifiedShow Answer

Maximum cardinality refers to ________.

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Data modelers agree that weak,non-ID-dependent entities exist and are important.

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In E-R modeling,an attribute describes the characteristics of an entity.

Correct AnswerverifiedShow Answer

In a 1:N relationship,the term parent refers to the N side of the relationship.

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-You are given an E-R diagram with two entities,ORDER and CUSTOMER,as shown above.What does the symbol next to the CUSTOMER entity indicate?

Correct AnswerverifiedShow Answer

The characteristics of a thing are described by its ________.

Correct AnswerverifiedShow Answer

When an entity has a relationship to itself,we have a(n) ________.

Correct AnswerverifiedShow Answer

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