Deck 4: Entity Relationship Er Modeling

Question 1

Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship.

Answer 1

False

Question 2

Relationships between entities always operate in one direction.

Answer 2

False

Question 3

An entity in the entity relationship model corresponds to a table in the relational environment.

Answer 3

True

Question 4

Connectivities and cardinalities are established by concise statements known as business rules.

Question 5

The Crow's Foot notation easily identifies multivalued attributes.

Question 6

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

Question 7

In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an entity rectangle with a line.

Question 8

The entity relationship model (ERM) is dependent on the database type.

Question 9

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

Question 10

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

Question 11

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

Question 12

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

Question 13

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

Question 14

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

Question 15

In the entity relationship model, a table row corresponds to an entity instance.

Question 16

Composite attributes make it easier to facilitate detailed queries.

Question 17

To implement a small database, a database designer must know the "1" and the "M" sides of each relationship and whether the relationships are mandatory or optional.

Question 18

In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first.

Question 19

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

Question 20

In implementation terms, an entity is existence-dependent if it has a mandatory primary key.

Question 21

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

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

Question 22

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

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

Question 23

If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as a(n) _____ entity.

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

Question 24

The conceptual model can handle _____ relationships and multivalued attributes.

A) 1:1
B) M:N
C) 1:M
D) 1:N

Question 25

In the entity relationship diagram (ERD), cardinality is indicated using the _____ notation, where max is the maximum number of associated entities and min represents the minimum number of associated entities.

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

Question 26

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) child

Question 27

The existence of a(n) _____ entity indicates that its minimum cardinality is zero.

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

Question 28

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

A) Connectivity
B) Relationship
C) Dependence
D) Cardinality

Question 29

Knowing the minimum and maximum number of _____ occurrences is very helpful at the application software level.

A) object
B) attribute
C) data
D) entity

Question 30

A(n) _____ is the set of possible values for a given attribute.

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

Question 31

A relationship is an association between _____.

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

Question 32

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

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

Question 33

The decision to store _____ attributes in database tables depends on the processing requirements and the constraints placed on a particular application.

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

Question 34

A derived attribute is indicated in the Chen notation by a _____ that connects the attribute and an entity.

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

Question 35

The entity relationship diagram (ERD) represents the _____ database as viewed by the end user.

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

Question 36

The _____ notation of entity-relationship modelling can be used for both conceptual and implementation modelling.

A) Bachman
B) UML
C) Chen
D) Crow's Foot

Question 37

When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of _____.

A) symbols
B) attributes
C) images
D) tables

Question 38

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) data

Question 39

A _____ relationship exists when three entities are associated.

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

Question 40

A _____ attribute is one that cannot be subdivided.

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

Question 41

The Crow's Foot notation depicts the strong relationship with a(n) _____ line between the entities.

Question 42

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

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

Question 43

When indicating cardinality, the first value represents the _____ number of associated entities.

Question 44

When using the Crow's Foot notation, the associative entity is indicated by _____ relationship lines between the parents and the associative entity.

A) dotted
B) double
C) triple
D) solid

Question 45

The concept of relationship strength is based on how the _____ of a related entity is defined.

Question 46

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities.

A) M:N
B) 1:M
C) N:1
D) M:1

Question 47

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

Question 48

A person's Social Security number would be an example of a(n) _____ attribute.

Question 49

The first step in building an entity-relationship diagram (ERD) is _____.

A) developing the initial ERD
B) creating a detailed narrative of the organization's description of operation
C) identifying the attributes and primary keys that adequately describe the entities
D) identifying the business rules based on the description of operations

Question 50

To simplify the conceptual design, most higher-order relationships are decomposed into appropriate equivalent _____ relationships whenever possible.

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

Question 51

A(n) _____ relationship is also known as an identifying relationship.

Question 52

_____ are underlined in an ER diagram.

Question 53

_____ are characteristics of entities.

Question 54

A relationship _____ is difficult to establish if only one side of the relationship is known.

Question 55

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 56

Database design is a(n) _____ process based on repetition.

A) sequential
B) iterative
C) linear
D) intermittent

Question 57

In organizations that generate large number of transactions, _____ are often a top priority in database design.

A) relationships among entities
B) logical design standards
C) naming conventions
D) high processing speeds

Question 58

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

Question 59

If Tiny College has some departments that are classified as "research only" and do not offer courses, the COURSE entity of the college database would be _____ the DEPARTMENT entity.

A) existence-dependent on
B) independent of
C) mandatory for
D) optional to

Question 60

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 61

The Chen notation identifies a weak entity by using a double-walled entity _____.

Question 62

Explain multivalued attributes with the help of examples. How are multivalued attributes indicated in the Chen Entity Relationship model?

Question 63

Identifying the attributes of entities helps in the better understanding of _____ among entities.

Question 64

What is a weak relationship? Provide an example.

Question 65

_____ not only helps database designers to stay on track during the design process, it also enables them to pick up the design thread when the time comes to modify the design.

Question 66

Explain recursive relationships with the help of an example.

Question 67

What is a ternary relationship? Provide some business rules examples that specify the need for a ternary or higher-order relationship.

Question 68

Explain mandatory participation in an entity relationship.

Question 69

In Crow's Foot notation, an optional relationship between entities is shown by drawing a(n) _____ on the side of the optional entity.

Question 70

In organizations that generate large numbers of transactions, _____ processing speeds are often a top priority in database design, whichresult inminimal access time.
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Question 71

Failure to understand the distinction between mandatory and optional _____ in relationships might yield designs in which awkward (and unnecessary) temporary rows (entity instances) must be created just to accommodate the creation of required entities.

Question 72

Participation is _____ if one entity occurrence does not require a corresponding entity occurrence in a particular relationship.

Question 73

A relationship _____ indicates the number of entities or participants associated with a relationship.

Question 74

A(n) _____ process is based on repetition of processes and procedures.

Question 75

A weak entity must be _____-dependent.