Deck 17: Database Design

Question 1

There are no questions in this section.

Question 2

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

A)crow's foot
B)attribute
C)entity
D)identifier

Answer 2

A

Question 3

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

Answer 3

True

Question 4

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

Answer 4

False

Question 5

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

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

Question 6

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

Question 7

A(n)________ notation signifies that an adviser can be related to many students and that a student can be related to many advisers.

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

Question 8

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

Question 9

Which of the following is true of a data model?

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

Question 10

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

Question 11

Entities have relationships to attributes but not to each other.

Question 12

Explain the database development process.

Question 13

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

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

Question 14

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

Question 15

In an organisation,a single clerk is working in the administrative department.The notation that accurately indicates this relationship is ________.

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

Question 16

Which of the following is true of entities?

A)The relationships between entities are known as attributes.
B)Entities' characteristics are described by attributes.
C)Entities can only represent a logical construct or transaction,not a physical object.
D)An identifier's value is associated with every entity in the data model.

Question 17

Which of the following is true of an E-R diagram?

A)Every entity has an identifier.
B)Many-to-many relationships are generally denoted as N:N.
C)A crow's-foot is required to represent a 1:1 relationship.
D)Identifiers are shown in a section at the top of the entity.

Question 18

________ describe the characteristics of entities.

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

Question 19

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

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

Question 20

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)________.

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

Question 21

Entities have attributes that describe characteristics of the entity.

Question 22

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

Question 23

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

A)replication
B)normalisation
C)actualisation
D)integration

Question 24

How is a data model transformed into a database design?

Question 25

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

Question 26

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

Question 27

Normalisation is the process of converting a poorly structured table into two or more well-structured tables.

Question 28

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

Question 29

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

A)normal forms
B)cardinalities
C)attributes
D)entities

Question 30

Explain the difference between maximum and minimum cardinality.

Question 31

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

Question 32

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

Question 33

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

Question 34

Normalised tables eliminate ________.

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

Question 35

The general goal of normalisation is to ________.

A)convert two or more tables into a single table
B)create a copy of an existing table
C)construct tables such that every table has a single topic
D)construct tables such that all tables have a similar topic

Question 36

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

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

Question 37

A vertical bar on a line representing a relationship indicates that there is a minimum requirement for the entity.

Question 38

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

Question 39

The N:N notation indicates that the same number of entities are present on each end of the relationship.

Question 40

Tables that are not normalised can have data integrity problems.

Question 41

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

Question 42

Explain the role of users in designing a database.

Question 43

The easiest time to change the database structure is ________.

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

Question 44

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

Question 45

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