Question 1

From a data modeling point of view, _____ data refer to data whose values change over time and for which one must keep a history of the data changes.

Accepted Answer

time-variant

Question 2

Overlapping subtypes are subtypes that contain a unique subset of the supertype entity set.

Accepted Answer

A) True 
 B)False  False

Question 3

The "_____" characteristic of a primary key states that the primary key should not have embedded semantic meaning.

Accepted Answer

A)   unique values
B)   nonintelligent
C)   preferably single-attribute
D)   security-compliant B

Question 4

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

Accepted Answer

A)   nonequality
B)   less than
C)   greater than
D)   equality

Question 5

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 supertype

Question 6

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)   surrogate

Question 7

To model time-variant data, one must create a new entity in an M:N relationship with the original entity.

Accepted Answer

A) True 
 B)False

Question 8

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 constraint

Question 9

Differentiate between specialization and generalization.

Accepted Answer

The answer of Differentiate between specialization and generalization....

Question 10

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 11

A partial completeness constraint is represented by _____.

Accepted Answer

A)   a dotted line
B)   two dashed lines
C)   a single horizontal line under a circle
D)   a double horizontal line over a circle

Question 12

A total completeness constraint is represented by a _____.

Accepted Answer

A)   smaller circle inside a bigger circle
B)   rhombus inside a circle
C)   double horizontal line under a circle
D)   single horizontal line above a circle

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

In which two cases are composite primary keys particularly useful?

Accepted Answer

The answer of In which two cases are composite primary...

Question 15

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 16

An entity supertype can have disjoint or overlapping entity subtypes.

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A)   Subtype discriminator can be null.
B)   Subtype discriminator cannot be null.
C)   Each supertype occurrence is a member of only one subtype.
D)   Each supertype occurrence is a member of at least one subtype.

Question 19

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

Accepted Answer

The answer of _____ keys work with primary keys to...

Question 20

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

Accepted Answer

A)   subtype discriminator
B)   inheritance
C)   specialization hierarchy
D)   entity supertype

Exam 5: Advanced Data Modeling

From a data modeling point of view, _____ data refer to data whose values change over time and for which one must keep a history of the data changes.

Overlapping subtypes are subtypes that contain a unique subset of the supertype entity set.

The "_____" characteristic of a primary key states that the primary key should not have embedded semantic meaning.

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

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

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

To model time-variant data, one must create a new entity in an M:N relationship with the original entity.

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

Differentiate between specialization and generalization.

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

A partial completeness constraint is represented by _____.

A total completeness constraint is represented by a _____.

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.

In which two cases are composite primary keys particularly useful?

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

An entity supertype can have disjoint or overlapping entity subtypes.

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

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

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

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