Deck 3: The Enhanced E-R Model and Business Rules

Question 1

In the figure below,which of the following are subtypes of patient?

A) Outpatient
B) Physician
C) Bed
D) All of the above

Answer 1

A

Question 2

In the figure below,a student:

A) must be a graduate student, an undergraduate, a special student or some other type of student.
B) must be a graduate student or an undergraduate student.
C) must be at least a special student.
D) none of the above.

Answer 2

A

Question 3

In the figure below,the patient must be either an outpatient or a resident patient.This is an example of the ________ rule.

A) disjoint
B) specialization
C) generalization
D) overlap

Answer 3

A

Question 4

Which of the following is a generic entity type that has a relationship with one or more subtypes?

A) Megatype
B) Supertype
C) Subgroup
D) Class

Question 5

The subtype discriminator in the figure below is:

A) Part_Type.
B) Part_No.
C) Manufactured Part.
D) Location.

Question 6

The ________ rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship.

A) semi-specialization
B) total specialization
C) partial specialization
D) total convergence

Question 7

The process of defining a more general entity type from a set of more specialized entity types is called:

A) generalization
B) specialization
C) normalization
D) none of the above

Question 8

The subtype discriminator is a composite attribute when there is a(n):

A) overlap rule.
B) disjoint rule.
C) partial specialization.
D) full specialization.

Question 9

The ________ rule states that an entity instance can simultaneously be a member of two (or more)subtypes.

A) disjoint
B) overlap
C) partial specialization
D) total specialization

Question 10

The ________ rule specifies that an entity can be a member of only one subtype at a time.

A) exclusion
B) disjoint
C) removal
D) inclusion

Question 11

In the figure below,to which of the following entities are the entities "CAR" and "TRUCK" generalized?

A) Make
B) Vehicle
C) Model
D) Price

Question 12

A ________ addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes.

A) disjointedness constraint
B) disjoint rule
C) partial specialization
D) total specialization

Question 13

An attribute of the supertype that determines the target subtype(s)is called the:

A) determinant.
B) subtype decision.
C) disjoint indicator.
D) none of the above.

Question 14

The property by which subtype entities possess the values of all attributes of a supertype is called:

A) hierarchy reception.
B) class management.
C) attribute inheritance.
D) generalization.

Question 15

In a supertype/subtype hierarchy,subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ________ in the hierarchy.

A) subtypes
B) supertypes
C) constraints
D) dimensions

Question 16

Subtypes should be used when:

A) there are attributes that apply to some but not all instances of an entity type.
B) supertypes relate to objects outside the business.
C) the instances of a subtype do not participate in a relationship that is unique to that subtype.
D) none of the above.

Question 17

In a supertype/subtype hierarchy,each subtype has:

A) only one supertype.
B) many supertypes.
C) at most two supertypes.
D) at least one subtype.

Question 18

Which of the following is a completeness constraint?

A) Total specialization
B) Partial generalization
C) Total recall
D) Partial hybridization

Question 19

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype.

A) semi-specialization
B) total specialization
C) partial specialization
D) disjointedness

Question 20

The process of defining one or more subtypes of a supertype and forming relationships is called:

A) specialization.
B) generalization.
C) creating discord.
D) selecting classes.

Question 21

A member of a subtype does NOT necessarily have to be a member of the supertype.

Question 22

An entity instance of a subtype represents the same entity instance of the supertype.

Question 23

A generic or template data model that can be reused as a starting point for a data modeling project is called a(n):

A) packaged data model.
B) universal data model.
C) enterprise data model.
D) none of the above.

Question 24

A generic data model is a good starting point for ________.

A) total specialization
B) requirements analysis
C) implementation
D) maintenance

Question 25

Supertype/Subtype relationships should be used when the instances of a subtype participate in no relationships which are unique to that subtype.

Question 26

The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype,it MUST simultaneously be a member of another subtype.

Question 27

The overlap rule specifies that if an entity instance of the supertype is a member of one subtype,it can simultaneously be a member of two (or more)subtypes.

Question 28

An entity cluster is:

A) a formal method for specifying attributes of related entities.
B) a set of one or more entity types and associated relationships grouped into a single abstract entity type.
C) a useful way to present data for a small and fairly simple organization.
D) a way of developing more granular views of the data model.

Question 29

A subtype can become a supertype if the subtype has other subtypes beneath it.

Question 30

Specialization is the reverse of generalization.

Question 31

When subtypes are overlapping,an additional field must be added to the supertype to act as a discriminator.

Question 32

All of the following are steps to using a packaged data model EXCEPT:

A) identify the parts of the data model that apply to your data modeling situation.
B) utilize all business rules that come with the packaged data model.
C) rename the identified data elements.
D) map data to be used in packages with existing data in the current databases.

Question 33

Packaged data models:

A) are ready to use right out of the box.
B) require customization
C) allow partial specialization.
D) cannot be used for most applications.

Question 34

In packaged data models,strong entities always have ________ between them.

A) weak entities
B) 1:1 relationships
C) 1:M relationships
D) M:N relationships

Question 35

A subtype is a generic entity that has a relationship with one or more entities at a lower level.

Question 36

Generalization is a top-down process.

Question 37

The figure below,is an example of a(n):

A) supertype/subtype hierarchy.
B) hierarchical data model.
C) entity cluster.
D) none of the above.

Question 38

In packaged data models,all subtype/supertype relationships follow the ________ and ________ rules

A) partial specialization and disjoint
B) total specialization and disjoint
C) total specialization and overlap
D) partial specialization and overlap

Question 39

Which of the following is NOT true of packaged data models?

A) Relationships are connected to the highest-level entity type in an order that makes sense.
B) All subtype/supertype relationships follow the total specialization and disjoint rules.
C) No entities on the many side of a relationship can be weak.
D) Both B and C.

Question 40

A completeness constraint may specify that each entity of the supertype must be a member of some subtype in the relationship.

Question 41

Subtypes at the lowest level of a hierarchy do not inherit attributes from their ancestors.

Question 42

A subgrouping of the entities in an entity type that shares common attributes or relationships is called a(n)________.

Question 43

In a supertype/subtype hierarchy,attributes are assigned at the highest logical level that is possible in the hierarchy.

Question 44

The ________ specifies that each entity instance of the supertype must be a member of some subtype in the relationship.

Question 45

Packaged data models are meant to be customized.

Question 46

A ________ is a constraint that addresses the question of whether an instance of a supertype may simultaneously be a member of two or more subtypes.

Question 47

Data models of an existing database are harder for data modelers to read.

Question 48

An entity cluster should focus on some area of interest to some community of users,developers or managers.

Question 49

Packaged data models can be developed using proven components.

Question 50

A universal data model is a generic or template data model that can be reused as a starting point for a data modeling project.

Question 51

A ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be a member of at least one subtype.

Question 52

Packaged data models cause projects to take more time to build.

Question 53

Attribute inheritance is a property of subtype entities where they inherit ________ of all attributes of the supertype.

Question 54

Entity clustering is a methodology for grouping one or more entity types and associated relationships into a single abstract entity type.

Question 55

You should consider using supertype/subtypes when there are ________ that apply to some (but not all)instances of an entity type.

Question 56

Packaged data models use an entity type to store union data.

Question 57

Creating a data model from a packaged data model requires much more skill than creating one from scratch.

Question 58

Packaged data models are as flexible as possible because all supertype/subtype relationships allow the total specialization and overlap rules.

Question 59

The process of defining one or more subtypes of the supertype and forming supertype/subtype relationships is called ________.

Question 60

An entity cluster can have a relationship with another entity cluster much the same way that an entity can have a relationship with another entity.

Question 61

How is the data modeling process different when starting with a purchased solution?

Question 62

The ________ specifies that an entity instance can simultaneously be a member of two or more subtypes.

Question 63

Discuss when you would use total specialization and when you would use partial specialization.

Question 64

A packaged data model can either be ________ or ________.

Question 65

Contrast the overlap rule to the disjoint rule.

Question 66

A(n)________ is a set of one or more entity types and associated relationships grouped into a single abstract entity type.

Question 67

Explain why the E-R model needed to be expanded into the enhanced E-R model.

Question 68

A supertype/subtype hierarchy is an arrangement of supertypes and subtypes where each ________ has only one ________.

Question 69

An attribute of the supertype whose values determine the target subtype(s)is called a(n)________.

Question 70

Explain the terms subtype and supertype.Discuss the differences between them.

Question 71

Why are packaged data models gaining popularity?

Question 72

Explain what entity clustering is.

Question 73

Describe how subtype discriminators are used when we have overlapping subtypes.

Question 74

Compare and contrast generalization and specialization.