Question 1

A ternary relationship is a relationship between instances of two entity types and is the most common type of relationship encountered in data modeling.

Accepted Answer

A ternary relationship is a relationship between instances of three entity types, not two.

Question 2

An entity type that associates the instances of only one type and contains attributes that are peculiar to the relationship between those entity instances.

Accepted Answer

This description refers to a reflexive or recursive relationship, not an entity type. An entity type typically represents a set of objects or concepts in the real world, while a reflexive relationship is a specific type of relationship that connects instances of the same entity type.

Question 3

A ________ is an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other sub-groupings.

Accepted Answer

A subtype is a subgrouping of an entity type that has distinct attributes or relationships, differentiating it from other sub-groupings within the same super-type.

Question 4

An identifier is a candidate key that has been selected to be used as the unique characteristic for an entity type.

Accepted Answer

An identifier is a candidate key that is chosen to uniquely identify instances of an entity type. It is used to differentiate between different instances of the same entity type. Therefore, an identifier is a unique characteristic for an entity type.

Question 5

The ________ rule specifies that if an entity instance of the super type is a member of one subtype,it cannot simultaneously be a member of any other subtype.

Accepted Answer

The disjoint rule is defined as the rule in which an entity instance of the supertype can only be a member of one subtype at a time; it cannot be a member of any other subtype. This rule is also known as exclusivity constraint. In contrast, the overlap rule specifies that an entity instance of the supertype can be a member of more than one subtype simultaneously. The business and partial specialization options are not relevant to this question.

Question 6

List at least four requirements for determination questions for data modeling.Include a question and which asset is related to that determination.

Accepted Answer

The answer of List at least four requirements for determination...

Question 7

List and explain the following key data modeling terms: entity,attribute,relationship,degree,cardinality,and associative entity.

Accepted Answer

The answer of List and explain the following key data...

Question 8

A state is a named property or characteristic of an entity that is of interest to the organization.

Accepted Answer

A state is a condition or situation of an entity at a particular point in time, not a named property or characteristic.

Question 9

One situation in which a relationship must be turned into an associative entity is when the associative entity has other relationships with entities besides the relationship that caused its creation.

Accepted Answer

When an associative entity has other relationships with entities besides the relationship that caused its creation, it becomes necessary to turn it into a separate entity to properly represent those relationships. This is because an associative entity is meant to only represent the relationship between two other entities, and cannot accurately capture additional relationships. By creating a separate entity, all relevant relationships can be properly represented and managed.

Question 10

A relationship definition explains what action is being taken and possibly why it is important.It may be important to state who or what does the action,but it is not important to explain how the action is taken.

Accepted Answer

The statement accurately describes the purpose and scope of a relationship definition. It only focuses on stating the action and reason behind it, without delving into the specifics of how it is done.

Question 11

The ________ rule specifies that each entity instance of the super-type must be a member of some subtype of the relationship.

Accepted Answer

The total specialization rule specifies that each entity instance of the super-type must be a member of some subtype of the relationship. This means that every instance of the supertype must belong to at least one subtype. Therefore, the correct answer is D.

Question 12

What is the link between a data model and a DFD?

Accepted Answer

The answer of What is the link between a data...

Question 13

The ________ rule specifies that an entity instance of the super type does not have to belong to any subtype.

Accepted Answer

This is called partial specialization, where an entity of the super type can exist without belonging to any subtype. Total specialization would have required the entity to belong to one of the subtypes, while overlap and disjoint refer to how the subtypes relate to each other.

Question 14

Define unary,binary,and ternary relationships.Provide an example of each relationship.

Accepted Answer

The answer of Define unary,binary,and ternary relationships.Provide an example of...

Question 15

A supertype is a generic entity type that has a relationship with one or more subtypes.

Accepted Answer

This statement is true. A supertype is a higher-level entity type that has one or more subtypes beneath it. The supertype provides a common set of attributes and relationships that are shared by its subtypes.

Question 16

The minimum cardinality of a relationship is the minimum number of instances of entity B that may be associated with each instance of entity A.

Accepted Answer

The statement is true as the minimum cardinality of a relationship defines the minimum number of instances of entity B that can be associated with each instance of entity A.

Question 17

An aggregation is an association between the instances of one or more entity types that is of interest to the organization.

Accepted Answer

The answer of An aggregation is an association between the...

Question 18

Explain the concept of cardinality.Give an example.

Accepted Answer

The answer of Explain the concept of cardinality.Give an example....

Question 19

A primary key is an attribute (or combination of attributes)that uniquely identifies each instance of an entity type.

Accepted Answer

The answer of A primary key is an attribute (or...

Question 20

Naming relationships can be difficult.Describe at least three guidelines for naming relationships.

Accepted Answer

The answer of Naming relationships can be difficult.Describe at least...

Quiz 8: Structuring System Data Requirements