Question 1

Which of the following is a specialization hierarchy overlapping constraint scenario in case of partial completeness?

Accepted Answer

A)  Subtype sets are unique.
B)  Supertype has optional subtypes.
C)  Subtype discriminators cannot be null.
D)  Subtype does not have a supertype.E) A) and B)
F) A) and C)

Question 2

A key is a real-world,generally accepted identifier used to uniquely identify real-world objects.

Accepted Answer

A)  primary
B)  natural
C)  foreign
D)  surrogateE) A) and B)
F) C) and D)

Question 3

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) None of the above
F) A) and B)

Question 4

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 5

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 6

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

Accepted Answer

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

Question 7

Composite primary keys are particularly useful as identifiers of composite entities,where each primary key combination is allowed in the M:N relationship.

Accepted Answer

The answer of Composite primary keys are particularly useful as...

Question 8

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

Accepted Answer

A)  Foreign key constraint
B)  nonunique constraint
C)  overlapping constraint
D)  disjoint constraintE) B) and C)
F) None of the above

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

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

Accepted Answer

A)  enclosed entity relationship model
B)  enhanced entity relationship model
C)  entity clustering relationship model
D)  extended entity relationship diagramE) C) and D)
F) All of the above

Question 11

Within a specialization hierarchy,a supertype can exist only within the context of a subtype.

Accepted Answer

A) True 
 B)False

Question 12

When selecting a foreign key placement for a 1:1 relationship,place the PK of the entity on the mandatory side in the entity on the optional side as a FK,and make the FK mandatory when .

Accepted Answer

A)  one side is mandatory and the other sides is optional
B)  one side participates in another relationship
C)  both sides are optional
D)  both sides are mandatoryE) B) and C)
F) A) and D) A

Question 13

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

Accepted Answer

If an attribute has semantic meaning,it ...

Question 14

completeness means that not every supertype occurrence is a member of a subtype.

Accepted Answer

The answer of completeness means that not every supertype occurrence...

Question 15

relationships occur when there are multiple relationship paths between related entities.

Accepted Answer

A)  Redundant
B)  Duplicated
C)  Time-variant
D)  SupertypeE) A) and D)
F) A) and B)

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

Within a specialization hierarchy,every subtype can have supertype(s) to which it is directly related.

Accepted Answer

A)  zero
B)  only one
C)  one or many
D)  manyE) A) and C)
F) A) and B)

Question 18

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 for the entities
D)  place the surrogate key in both entitiesE) A) and B)
F) A) and C) C

Question 19

The main concern with redundant relationships is that they remain across the model.

Accepted Answer

The answer of The main concern with redundant relationships is...

Question 20

According to the "preferably single­attribute" characteristic of a primary key,the primary key:

Accepted Answer

A)  must be able to guarantee unique attribute values.
B)  should have the minimum number of attributes possible.
C)  should have embedded semantic meaning associated with each attribute.
D)  must be composed of attributes that are free from security risks or violations.E) A) and C)
F) All of the above

Exam 5: Advanced Data Modeling

Which of the following is a specialization hierarchy overlapping constraint scenario in case of partial completeness?

Correct AnswerverifiedShow Answer

A key is a real-world,generally accepted identifier used to uniquely identify real-world objects.

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

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

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedD

Composite primary keys are particularly useful as identifiers of composite entities,where each primary key combination is allowed in the M:N relationship.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Within a specialization hierarchy,a supertype can exist only within the context of a subtype.

Correct AnswerverifiedShow Answer

When selecting a foreign key placement for a 1:1 relationship,place the PK of the entity on the mandatory side in the entity on the optional side as a FK,and make the FK mandatory when .

Correct AnswerverifiedA

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

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

completeness means that not every supertype occurrence is a member of a subtype.

Correct AnswerverifiedShow Answer

relationships occur when there are multiple relationship paths between related entities.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Within a specialization hierarchy,every subtype can have supertype(s) to which it is directly related.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedC

The main concern with redundant relationships is that they remain across the model.

Correct AnswerverifiedShow Answer

According to the "preferably single­attribute" characteristic of a primary key,the primary key:

Correct AnswerverifiedShow Answer

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D

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A

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If an attribute has semantic meaning,it ...
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C

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According to the "preferably singleattribute" characteristic of a primary key,the primary key:

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