Question 1

The completeness constraint can be partial or total.

Accepted Answer

A) True 
 B)False

Question 2

An entity cluster is considered "virtual" or " " in the sense that it is not actually an entity in the final ERD.

Accepted Answer

The answer of An entity cluster is considered "virtual" or...

Question 3

completeness means that every supertype occurrence must be a member of at least one subtype.

Accepted Answer

The answer of completeness means that every supertype occurrence must...

Question 4

The preferred placement for a foreign key when working with a 1:1 relationship is to .

Accepted Answer

A)   use the same primary key for both entities
B)   create a bridge entity
C)   place the foreign key in one of the entities
D)   place the surrogate key in both entitiesE) All of the above
F) B) and C)

Question 5

If one exists, a data modeler uses a as the primary key of the entity being modeled.

Accepted Answer

A)   foreign key
B)   combination key
C)   surrogate key
D)   natural identifierE) B) and C)
F) None of the above

Question 6

In the context of total completeness, in a(n)  , every supertype occurrence is a member of at least one subtype.

Accepted Answer

A)   unique constraint
B)   disjoint constraint
C)   overlapping constraint
D)   foreign key constraintE) A) and B)
F) All of the above

Question 7

Nonoverlapping subtypes are subtypes that contain a(n)  subset of the supertype entity set.

Accepted Answer

A)   entity
B)   subtypes
C)   unique
D)   nonuniqueE) B) and D)
F) B) and C)

Question 8

The " " characteristic of a primary key states that the primary key must uniquely identify each entity instance, must be able to guarantee unique values, and must not contain nulls.

Accepted Answer

A)   unique values
B)   nonintelligent
C)   preferably single-attribute
D)   security-complaintE) B) and C)
F) None of the above

Question 9

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

Accepted Answer

A)   primary
B)   natural
C)   foreign
D)   surrogateE) A) and B)
F) None of the above

Question 10

In which two cases are composite primary keys particularly useful?

Accepted Answer

Composite primary keys are particularly ...

Question 11

Implementing nonoverlapping subtypes requires the use of one discriminator attribute for each subtype.

Accepted Answer

A) True 
 B)False

Question 12

Entity subtypes do not inherit the relationships in which the supertype entity participates.

Accepted Answer

A) True 
 B)False

Question 13

While using a surrogate key, one must ensure that the candidate key of the entity in question performs properly through the use of the " " and "not null" constraints.

Accepted Answer

The answer of While using a surrogate key, one must...

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

Differentiate between specialization and generalization.

Accepted Answer

Specialization is the top-down process o...

Question 16

data refer to data whose values change over time and for which one must keep a history of the data changes.

Accepted Answer

A)   Time-sensitive
B)   Time-variant
C)   Historical
D)   Change-basedE) A) and B)
F) B) and D)

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

Describe an entity cluster.

Accepted Answer

An entity cluster is a "virtual" entity ...

Question 19

One practical advantage of a(n) key is that because it has no intrinsic meaning, values for it can be generated by the DBMS to ensure that unique values are always provided.

Accepted Answer

The answer of One practical advantage of a(n) key is...

Question 20

Generalization is based on grouping unique characteristics and relationships of the subtypes.

Accepted Answer

A) True 
 B)False

Exam 5: Advanced Data Modeling

Entity subtypes do not inherit the relationships in which the supertype entity participates.

Correct AnswerverifiedShow Answer

Implementing nonoverlapping subtypes requires the use of one discriminator attribute for each subtype.

Correct AnswerverifiedShow Answer

Describe an entity cluster.

Correct AnswerverifiedAn entity cluster is a "virtual" entity ...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

While using a surrogate key, one must ensure that the candidate key of the entity in question performs properly through the use of the " " and "not null" constraints.

Correct AnswerverifiedShow Answer

In which two cases are composite primary keys particularly useful?

Correct AnswerverifiedComposite primary keys are particularly ...View AnswerShow Answer

Differentiate between specialization and generalization.

Correct AnswerverifiedSpecialization is the top-down process o...View AnswerShow Answer

The completeness constraint can be partial or total.

Correct AnswerverifiedShow Answer

If one exists, a data modeler uses a as the primary key of the entity being modeled.

Correct AnswerverifiedShow Answer

The " " characteristic of a primary key states that the primary key must uniquely identify each entity instance, must be able to guarantee unique values, and must not contain nulls.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Nonoverlapping subtypes are subtypes that contain a(n) subset of the supertype entity set.

Correct AnswerverifiedShow Answer

completeness means that every supertype occurrence must be a member of at least one subtype.

Correct AnswerverifiedShow Answer

An entity cluster is considered "virtual" or " " in the sense that it is not actually an entity in the final ERD.

Correct AnswerverifiedShow Answer

data refer to data whose values change over time and for which one must keep a history of the data changes.

Correct AnswerverifiedShow Answer

Generalization is based on grouping unique characteristics and relationships of the subtypes.

Correct AnswerverifiedShow Answer

One practical advantage of a(n) key is that because it has no intrinsic meaning, values for it can be generated by the DBMS to ensure that unique values are always provided.

Correct AnswerverifiedShow Answer

The preferred placement for a foreign key when working with a 1:1 relationship is to .

Correct AnswerverifiedShow Answer

In the context of total completeness, in a(n) , every supertype occurrence is a member of at least one subtype.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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An entity cluster is a "virtual" entity ...
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Composite primary keys are particularly ...
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Specialization is the top-down process o...
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