Question 1

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

Accepted Answer

Nonoverlapping subtypes require only one discriminator attribute to determine which subtype an entity belongs to.

Question 2

The relationships depicted within the specialization hierarchy are sometimes described in terms of "is­a"
relationships.

Accepted Answer

The "is-a" relationship is a common way to describe the specialization hierarchy in object-oriented programming.

Question 3

The entity supertype contains common characteristics,and the entity subtypes each contain their own unique characteristics.

Accepted Answer

This statement is true. The entity supertype contains attributes that are common to all of its subtypes, while each subtype has its own unique attributes that distinguish it from the other subtypes.

Question 4

A subtype contains attributes that are common to all of its supertypes.

Accepted Answer

A subtype contains attributes that are specific to it, in addition to the common attributes inherited from its supertype(s).

Question 5

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

Accepted Answer

This is true. An entity cluster is a way to group together multiple entities that have a common relationship or attribute, and represent them as a single entity in the ERD.

Question 6

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

Accepted Answer

This is true for the subtype/supertype relationship in a database. When a subtype inherits from a supertype, it also inherits the primary key of the supertype. This allows all subtypes to be uniquely identified by the same primary key used for the supertype.

Question 7

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

Accepted Answer

Disjoint subtypes are subtypes where each entity instance of the supertype can belong to only one subtype, meaning their subsets do not overlap.

Question 8

Specialization is the top-down process of identifying lower-level,more specific entity subtypes from a higher-level entity supertype.

Accepted Answer

Specialization is indeed the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype.

Question 9

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

Accepted Answer

A subtype discriminator actually helps in determining which subtype an entity in the supertype corresponds to; it does not enable inheritance of attributes and relationships from the subtype to the supertype. Inheritance flows from the supertype to its subtypes, not the other way around.

Question 10

At the implementation level,the supertype and its subtype(s)depicted in the specialization hierarchy maintain a 1:1 relationship.

Accepted Answer

The answer of At the implementation level,the supertype and its...

Question 11

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

Accepted Answer

Overlapping subtypes are subtypes where an entity instance of the supertype can belong to more than one subtype, not exclusively to a unique subset.

Question 12

The function of the primary key is to describe an entity.

Accepted Answer

The function of the primary key is to uniquely identify each record or entry in a table, not describe an entity.

Question 13

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

Accepted Answer

Entity subtypes inherit relationships from their supertype entity, unless explicitly overridden or changed in some way. So, the statement is false.

Question 14

The completeness constraint can be partial or total.

Accepted Answer

The completeness constraint can be either partial or total, depending on the specific context and requirements. A partial completeness constraint allows for some missing or optional data, while a total completeness constraint requires all data to be present and accurate.

Question 15

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

Accepted Answer

Overlapping subtypes require a unique discriminator attribute for each subtype to distinguish between them. Therefore, each subtype needs its own discriminator attribute.

Question 16

Entity supertypes and subtypes are organized in a specialization hierarchy.

Accepted Answer

Entity supertypes and subtypes are indeed organized in a specialization hierarchy, where subtypes inherit attributes and behaviors from their parent supertype. This is a fundamental concept in entity-relationship modeling.

Question 17

In specialization hierarchies with multiple levels of supertype and subtypes,a lower-level subtype can inherit only a few of the attributes and relationships from its upper-level supertypes.

Accepted Answer

In specialization hierarchies, a lower-level subtype inherits all the attributes and relationships from its upper-level supertypes, not just a few.

Question 18

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

Accepted Answer

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

Question 19

An entity supertype can have disjoint or overlapping entity subtypes.

Accepted Answer

An entity supertype can have disjoint or overlapping entity subtypes. Disjoint entity subtypes have unique sets of characteristics, whereas overlapping entity subtypes have some shared characteristics.

Question 20

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

Accepted Answer

A supertype is a broader category that encompasses multiple subtypes. It exists independently and is not dependent on any of its subtypes.

Quiz 5: Advanced Data Modeling

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

The relationships depicted within the specialization hierarchy are sometimes described in terms of "isa" relationships.

The entity supertype contains common characteristics,and the entity subtypes each contain their own unique characteristics.

A subtype contains attributes that are common to all of its supertypes.

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

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

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

Specialization is the top-down process of identifying lower-level,more specific entity subtypes from a higher-level entity supertype.

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

At the implementation level,the supertype and its subtype(s)depicted in the specialization hierarchy maintain a 1:1 relationship.

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

The function of the primary key is to describe an entity.

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

The completeness constraint can be partial or total.

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

Entity supertypes and subtypes are organized in a specialization hierarchy.

In specialization hierarchies with multiple levels of supertype and subtypes,a lower-level subtype can inherit only a few of the attributes and relationships from its upper-level supertypes.

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

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.

Quiz 5: Advanced Data Modeling

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

The relationships depicted within the specialization hierarchy are sometimes described in terms of "is­a" relationships.

The entity supertype contains common characteristics,and the entity subtypes each contain their own unique characteristics.

A subtype contains attributes that are common to all of its supertypes.

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

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

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

Specialization is the top-down process of identifying lower-level,more specific entity subtypes from a higher-level entity supertype.

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

At the implementation level,the supertype and its subtype(s)depicted in the specialization hierarchy maintain a 1:1 relationship.

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

The function of the primary key is to describe an entity.

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

The completeness constraint can be partial or total.

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

Entity supertypes and subtypes are organized in a specialization hierarchy.

In specialization hierarchies with multiple levels of supertype and subtypes,a lower-level subtype can inherit only a few of the attributes and relationships from its upper-level supertypes.

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

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.

The relationships depicted within the specialization hierarchy are sometimes described in terms of "isa" relationships.