Deck 17: Database Design

Question 1

In an entity-relationship (E-R)diagram,a line is used to represent a relationship between two entities.

Answer 1

True

Question 2

The little lines in an entity-relationship (E-R)diagram used as shorthand to represent multiple relationships are referred to as a(n)________.

A)crow's foot
B)identifier
C)attribute
D)cardinality line

Answer 2

A

Question 3

Which of the following is true of entities?

A)Entities have an identifier whose value is associated with every entity in the data model.
B)Entities can only represent a logical construct or transaction,not a physical object.
C)The characteristics of entities are described by attributes.
D)The names of entities are always plural.

Answer 3

C

Question 4

________ describe the characteristics of entities.

A)Attributes
B)Dependencies
C)Cardinalities
D)Alternatives

Question 5

________ are attributes whose values are associated with one,and only one,entity instance.

A)Cardinalities
B)Descriptors
C)Dependencies
D)Identifiers

Question 6

In an organization,the administrative department consists of one clerk whose sole responsibility is the management of various administrative functions.The notation that accurately indicates this relationship is ________.

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

Question 7

Which of the following notations signifies that an adviser can be related to many students and that a student can be related to many advisers?

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

Question 8

A data model should be transformed into a database design only after the users have approved and validated it.

Question 9

Entities have relationships to attributes but not to each other.

Question 10

A data model is a logical representation of the structure of the data.

Question 11

Which of the following is a highly popular technique for creating a data model with which the developers describe the content of a database by defining what is to be stored in the database and the associations among them?

A)entity-relationship (E-R)data model
B)Unified Modeling Language (UML)
C)object-relational model
D)semantic data model

Question 12

A data model does not depict the relationships among the data.

Question 13

Once the users have validated and approved the data model,it is transformed into a ________.

A)database design
B)technical report
C)knowledge system
D)data repository

Question 14

Which of the following is true of a data model?

A)It is created after the database is designed.
B)It is an attribute whose value is associated with only one entity instance.
C)It is a logical representation of the structure of the data.
D)It does not describe the relationships among the data.

Question 15

Entities have attributes that describe characteristics of the entity.

Question 16

Explain the database development process.

Question 17

Which of the following is true of an entity-relationship (E-R)diagram?

A)Each entity is shown in separate rectangles.
B)Many-to-many relationships are generally denoted by N:N.
C)A crow's foot represents a 1:N relationship between two entities.
D)Crow's foot is a shorthand representation for a single relationship between entities.

Question 18

An identifier is an attribute whose value is associated with every entity in the data model.

Question 19

In a university,each adviser can advise multiple students,but each student can have only one adviser.In a data model,this can be best represented by ________.

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

Question 20

Maximum cardinality in an entity-relationship (E-R)diagram refers to the maximum number of ________.

A)normalizations possible in a diagram
B)entities that can be involved in a relationship
C)identifiers possible in a particular diagram
D)attributes associated with an entity

Question 21

Database practitioners classify tables into various normal forms according to the kinds of problems they have.

Question 22

The notation N:N is used to indicate a many-to-many relationship in an E-R diagram.

Question 23

How is a data model transformed into a database design?

Question 24

The process of converting poorly structured tables into two or more well-structured tables is referred to as ________.

A)replication
B)integration
C)actualization
D)normalization

Question 25

While representing the relationship between two entities in an entity-relationship diagram,the N:N notation is used to indicate that the same number of entities are present on each end of the relationship.

Question 26

The crow's foot notation shows the minimum number of entities that can be involved in a relationship.

Question 27

The data integrity problem can occur only if data are missing.

Question 28

To represent an N:M relationship between two entities,two normalized tables are sufficient.

Question 29

Normalization is a database design concept that helps to construct well-structured tables.

Question 30

What are the different types of relationships represented in a data model?

Question 31

The general goal of normalization is to ________.

A)create a copy of an existing table
B)establish relationships among the entities in a table
C)convert two or more tables into a single table
D)construct tables such that every table has a single topic

Question 32

The general goal of normalization is to construct tables such that every table has a single topic or theme.

Question 33

Explain the difference between maximum and minimum cardinality.

Question 34

Normalized tables eliminate ________.

A)data dependency
B)data duplication
C)data insufficiency
D)data conversion

Question 35

The maximum number of entities that can be involved in a relationship is known as maximum cardinality.

Question 36

1:N means that more than one entity is allowed on each side of the relationship.

Question 37

The data integrity problem can occur only if data are ________.

A)duplicated
B)missing
C)inefficient
D)insufficient

Question 38

According to the kinds of problems they have,database practitioners classify tables into various ________.

A)solved forms
B)cardinalities
C)normal forms
D)relationships

Question 39

In an entity-relationship diagram,a vertical bar on a line indicates that at least one entity of that type is required in the relationship.

Question 40

Tables that are not normalized can have data integrity problems.

Question 41

The easiest time to change the database structure is ________.

A)during the data modeling stage
B)after constructing the database
C)during the database designing stage
D)after creating database reports

Question 42

Explain the role of users in designing a database.

Question 43

What are the steps involved in transforming a data model into a relational database design?

Question 44

The easiest time to change the database structure is after the database has been constructed and loaded with data.