Question 1

An entity supertype can have disjoint or overlapping entity subtypes.

Accepted Answer

A) True 
 B)False

Question 2

Explain the "no change over time" characteristic of a good primary key.

Accepted Answer

If an attribute has semantic meaning,it ...

Question 3

A specialization hierarchy can have ____ level(s) of supertype/subtype relationships.

Accepted Answer

A)   zero
B)   only one
C)   one or many
D)   manyE) B) and C)
F) All of the above

Question 4

The _________________________ is the result of adding more semantic constructs to the original entity relationship (ER)model.

Accepted Answer

extended entity rela...

Question 5

In specialization hierarchies with multiple levels of supertype/subtypes,a lower-level supertype inherits all of the attributes and relationships from all of its upper-level subtypes.

Accepted Answer

A) True 
 B)False

Question 6

The default comparison condition for the subtype discriminator attribute is the ____ comparison.

Accepted Answer

A)   not equality
B)   less than
C)   greater than
D)   equalityE) None of the above
F) C) and D)

Question 7

A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.

Accepted Answer

A) True 
 B)False

Question 8

At the implementation level,the supertype and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.

Accepted Answer

A)   self-referencing
B)   1:1
C)   1:M
D)   M:NE) A) and B)
F) C) and D)

Question 9

Composite keys are useful as identifiers of weak entities,where the weak entity has a strong ____________________ relationship with the parent entity.

Accepted Answer

The answer of Composite keys are useful as identifiers of...

Question 10

Entity supertypes and subtypes are organized in a specialization hierarchy.

Accepted Answer

A) True 
 B)False  True

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

Disjoint subtypes are subtypes that contain nonunique subsets of the supertype entity set.

Accepted Answer

A) True 
 B)False

Question 13

The extended entity relationship model (EERM) is sometimes referred to as the ____.

Accepted Answer

A)   entity relationship model
B)   enhanced entity relationship model
C)   entity clustering relationship model
D)   extended entity relationship diagramE) A) and B)
F) None of the above

Question 14

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) B) and C)

Question 15

____ keys work with primary keys to properly implement relationships in the relational model.

Accepted Answer

A)   Foreign
B)   Composite
C)   Natural
D)   SurrogateE) All of the above
F) None of the above A

Question 16

What is an entity cluster?

Accepted Answer

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

Question 17

Some designs use redundant relationships as a way to simplify the design.

Accepted Answer

A) True 
 B)False

Question 18

What do specialization hierarchies do?

Accepted Answer

Entity supertypes and subtypes are organ...

Question 19

Describe specialization and generalization.

Accepted Answer

Specialization is the top-down process of identifying lower-level,more specific entity subtypes from a higher-level entity supertype.Specialization is based on grouping the unique characteristics and relationships of the subtypes.In the aviation example,you used specialization to identify multiple entity subtypes from the original employee supertype.Generalization is the bottom-up process of identifying a higher-level,more generic entity supertype from lower-level entity subtypes.Generalization is based on grouping the common characteristics and relationships of the subtypes.For example,you might identify multiple types of musical instruments: piano,violin,and guitar.Using the generalization approach,you could identify a "string instrument" entity supertype to hold the common characteristics of the multiple subtypes.

Question 20

A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

Accepted Answer

A)   subtype discriminator
B)   inheritance discriminator
C)   specialization hierarchy
D)   entity supertypeE) C) and D)
F) B) and D)

Exam 5: Advanced Data Modeling

An entity supertype can have disjoint or overlapping entity subtypes.

Correct Answer
verified

Explain the "no change over time" characteristic of a good primary key.

Correct Answer
verified
If an attribute has semantic meaning,it ...
View Answer

A specialization hierarchy can have ____ level(s) of supertype/subtype relationships.

Correct Answer
verified

The _________________________ is the result of adding more semantic constructs to the original entity relationship (ER)model.

Correct Answer
verified
extended entity rela...
View Answer

In specialization hierarchies with multiple levels of supertype/subtypes,a lower-level supertype inherits all of the attributes and relationships from all of its upper-level subtypes.

Correct Answer
verified

The default comparison condition for the subtype discriminator attribute is the ____ comparison.

Correct Answer
verified

A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.

Correct Answer
verified

At the implementation level,the supertype and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.

Correct Answer
verified

Composite keys are useful as identifiers of weak entities,where the weak entity has a strong ____________________ relationship with the parent entity.

Correct Answer
verified

Entity supertypes and subtypes are organized in a specialization hierarchy.

Correct Answer
verified
True

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

Correct Answer
verified

Disjoint subtypes are subtypes that contain nonunique subsets of the supertype entity set.

Correct Answer
verified

The extended entity relationship model (EERM) is sometimes referred to as the ____.

Correct Answer
verified

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

Correct Answer
verified

____ keys work with primary keys to properly implement relationships in the relational model.

Correct Answer
verified
A

What is an entity cluster?

Correct Answer
verified
An entity cluster is a "virtual" entity ...
View Answer

Some designs use redundant relationships as a way to simplify the design.

Correct Answer
verified

What do specialization hierarchies do?

Correct Answer
verified
Entity supertypes and subtypes are organ...
View Answer

Describe specialization and generalization.

A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

Correct Answer
verified

Exam 5: Advanced Data Modeling

An entity supertype can have disjoint or overlapping entity subtypes.

Correct AnswerverifiedShow Answer

Explain the "no change over time" characteristic of a good primary key.

Correct AnswerverifiedIf an attribute has semantic meaning,it ...View AnswerShow Answer

A specialization hierarchy can have ____ level(s) of supertype/subtype relationships.

Correct AnswerverifiedShow Answer

The _________________________ is the result of adding more semantic constructs to the original entity relationship (ER)model.

Correct Answerverifiedextended entity rela...View AnswerShow Answer

In specialization hierarchies with multiple levels of supertype/subtypes,a lower-level supertype inherits all of the attributes and relationships from all of its upper-level subtypes.

Correct AnswerverifiedShow Answer

The default comparison condition for the subtype discriminator attribute is the ____ comparison.

Correct AnswerverifiedShow Answer

A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.

Correct AnswerverifiedShow Answer

At the implementation level,the supertype and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.

Correct AnswerverifiedShow Answer

Composite keys are useful as identifiers of weak entities,where the weak entity has a strong ____________________ relationship with the parent entity.

Correct AnswerverifiedShow Answer

Entity supertypes and subtypes are organized in a specialization hierarchy.

Correct AnswerverifiedTrue

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

Correct AnswerverifiedShow Answer

Disjoint subtypes are subtypes that contain nonunique subsets of the supertype entity set.

Correct AnswerverifiedShow Answer

The extended entity relationship model (EERM) is sometimes referred to as the ____.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

____ keys work with primary keys to properly implement relationships in the relational model.

Correct AnswerverifiedA

What is an entity cluster?

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

Some designs use redundant relationships as a way to simplify the design.

Correct AnswerverifiedShow Answer

What do specialization hierarchies do?

Correct AnswerverifiedEntity supertypes and subtypes are organ...View AnswerShow Answer

Describe specialization and generalization.

A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
If an attribute has semantic meaning,it ...
View Answer

Correct Answer
verified

Correct Answer
verified
extended entity rela...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
True

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified
An entity cluster is a "virtual" entity ...
View Answer

Correct Answer
verified

Correct Answer
verified
Entity supertypes and subtypes are organ...
View Answer

Correct Answer
verified