Deck 4: Entity Relationship (ER)Modeling

Question 1

Derived attributes are stored in a special database table.

Answer 1

False

Question 2

All simple attributes are also single-valued.

Answer 2

False

Question 3

A composite identifier is a primary key composed of more than one attribute.

Answer 3

True

Question 4

The word "entity" in the ER model corresponds to a table.

Question 5

In the Chen model,a multivalued attribute is connected to the owning entity with a double line.

Question 6

Software vendors have adopted the Chen representation because of its compact representation.

Question 7

The ER model refers to a specific table row as an entity instance.

Question 8

The ER diagram represents the conceptual database as viewed by the end user.

Question 9

In an ER diagram,primary keys are usually bolded.

Question 10

The Crow's Foot model is less implementation-oriented than the Chen model.

Question 11

In both the Chen and Crow's Foot models,an entity is represented with a rectangle containing the entity's name.

Question 12

Ideally,a primary key is composed of several attributes.

Question 13

The ER model refers to a specific table row as an entity occurrence.

Question 14

Attributes cannot share a domain.

Question 15

Attributes have a domain that specifies the data type of the attribute.

Question 16

An ERM is dependent on the database type.

Question 17

The DBMS can easily handle multivalued attributes.

Question 18

All attributes are either simple or composite.

Question 19

Attributes are types of entities.

Question 20

In the original Chen model,each attribute is represented using an oval with the attribute name connected to the entity with a line.

Question 21

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

Question 22

Attributes may share a ____.

A) name
B) domain
C) location
D) table

Question 23

The set of possible values for an attribute is a ____.

A) domain
B) range
C) set
D) key

Question 24

Relationships operate only in one direction.

Question 25

A recursive relationship is one in which a relationship can exist between occurrences of the same entity set

Question 26

A relationship is identified by a name that describes the relationship.

Question 27

In an ER diagram,primary keys are indicated by ____.

A) bolding
B) italics
C) underlining
D) a special font

Question 28

A ____ identifier is composed of more than one attribute.

A) primary
B) foreign
C) composite
D) domain

Question 29

Some ____ database modeling concepts can be expressed only using the Chen notation.

A) developmental
B) conceptual
C) actual
D) specific

Question 30

Ideally,an entity identifier is composed of ____ attribute(s).

A) zero
B) one
C) two
D) six

Question 31

A ____ attribute is one that cannot be subdivided.

A) composite
B) simple
C) single-valued
D) multivalued

Question 32

A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

Question 33

Cardinality expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.

Question 34

In Chen notation,there is no way to represent cardinality.

Question 35

The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.

Question 36

A ____ attribute can be further subdivided to yield additional attributes.

A) composite
B) simple
C) single-valued
D) multivalued

Question 37

The ERD represents the ____ database as viewed by the end user.

A) condensed
B) physical
C) logical
D) conceptual

Question 38

You should always load data from the 1 side of a 1:M relationship.

Question 39

The ____ attribute(s)make up the primary key in the table definition: CLASS (CRS_CODE,CLASS_SECTION,CLASS_TIME,CLASS_ROOM,PROF_NUM)

A) CRS_CODE
B) CLASS_SECTION
C) CRS_CODE and CLASS_SECTION
D) There is no primary key

Question 40

Connectivities and cardinalities are established by business rules.

Question 41

An entity is said to be ____-dependent if it can exist in the database only when it is associated with another related entity occurrence.

A) existence
B) relationship
C) business
D) weak

Question 42

The term "____" is used to label any condition in which one or more optional relationships exist.

A) participation
B) optionality
C) cardinality
D) connectivity

Question 43

A ____ relationship exists when two entities are associated.

A) unary
B) binary
C) ternary
D) weak

Question 44

____ attributes can have many values.

A) Composite
B) Simple
C) Single-valued
D) Multivalued

Question 45

A ____ entity has a primary key that is partially or totally derived from the parent entity in the relationship.

A) strong
B) weak
C) business
D) relationship

Question 46

A ____ should be a derived attribute.

A) person's name
B) person's age
C) person's social security number
D) person's phone number

Question 47

A relationship is an association between ____.

A) objects
B) entities
C) databases
D) fields

Question 48

The existence of a(n)____ relationship indicates that the minimum cardinality is at least 1 for the mandatory entity.

A) mandatory
B) optional
C) multivalued
D) single-valued

Question 49

A derived attribute ____.

A) must be stored physically within the database
B) need not be physically stored within the database
C) has many values
D) must be based on the value of three or more attributes

Question 50

A derived attribute is indicated in the Chen model by a ____.

A) single line
B) dashed line
C) circle
D) double line

Question 51

A ____ relationship exists when an association is maintained within a single entity.

A) unary
B) ternary
C) binary
D) weak

Question 52

Some attributes are classified as ____.

A) simple
B) complex
C) defined
D) grouped

Question 53

When the PK of one entity does not contain the PK of a related entity,the relationship is ____.

A) missing
B) weak
C) strong
D) neutral

Question 54

Another word for existence-independent is ____.

A) weak
B) alone
C) unary
D) strong

Question 55

If an entity can exist apart from one or more related entities,it is said to be ____-independent.

A) existence
B) relationship
C) business
D) weak

Question 56

In the ERD,cardinality is indicated using the ____ notation.

A) (max, min)
B) (min, max)
C) [min ... max]
D) {min|max}

Question 57

A ____ attribute can have only one value.

A) composite
B) simple
C) single-valued
D) multivalued

Question 58

The ____ type of attribute cannot be created in a DBMS.

A) derived
B) multivalued
C) simple
D) composite

Question 59

Knowing the ____ number of entity occurrences is very helpful at the application software level.

A) maximum
B) minimum
C) approximate
D) maximum and minimum

Question 60

The Crow's foot symbol with two parallel lines indicates ____ cardinality.

A) (0,N)
B) (1,N)
C) (1,1)
D) (0,1)

Question 61

The ERM forms the basis of a(n)___________________________________.

Question 62

Instead of storing a person's age,it is better to store the date of birth and use the difference between that value and the system date as a(n)____________________ attribute.

Question 63

The Crow's Foot model is more ____________________-oriented than the Chen model.

Question 64

Storing ____________________ attributes requires constant maintenance.

Question 65

____ relationships are most common.

A) Unary
B) Binary
C) Ternary
D) Higher-degree

Question 66

A(n)____________________ attribute is an attribute that must have a value.

Question 67

A ____ relationship exists when three entities are associated.

A) unary
B) binary
C) ternary
D) weak

Question 68

If an employee within an EMPLOYEE entity has a relationship with itself,that relationship is known as a ____ relationship.

A) self
B) self-referring
C) looping
D) recursive

Question 69

A person's social security number would be an example of a(n)____________________ attribute.

Question 70

The ____________________ refers to a specific table row as an entity instance.

Question 71

____________________ are underlined in an ER diagram.

Question 72

If Tiny College had some departments that were classified as "research only," they would not offer courses;therefore,the COURSE entity would be ____ to the DEPARTMENT entity.

A) existence-dependent
B) independent
C) weak
D) optional

Question 73

____________________ are characteristics of entities.

Question 74

If the focus is on data-retrieval speed,you might also be forced to include ____ attributes in the design,which would not ordinarily be done.

A) multivalued
B) composite
C) weak
D) derived

Question 75

The M:N relationship between STUDENT and CLASS must be divided into two 1:M relationships through the use of the ENROLL entity;the ENROLL entity is ____.

A) weak
B) strong
C) optional
D) mandatory

Question 76

The associative entity is also known as a ____ entity.

A) unary
B) weak
C) strong
D) composite

Question 77

Complex ____ requirements may dictate data transformations,and they may expand the number of entities and attributes within the design.

A) information
B) entity
C) design
D) processing

Question 78

A(n)____________________ attribute need not be physically stored within the database.

Question 79

The following step occurs first in the process of building an ERD: ____.

A) Develop the initial ERD.
B) Create a detailed narrative of the organization's description of operations.
C) Identify the attributes and primary keys that adequately describe the entities.
D) Identify the business rules based on the description of operations.

Question 80

A(n)____ entity is composed of the primary keys of each of the entities to be connected.

A) associative
B) recursive
C) unary
D) binary