Deck 17: Database Design

Question 1

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) data integrity model

Answer 1

A

Question 2

Which of the following is true of entities?

A) An identifier's 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) Entities' characteristics are described by attributes.
D) The relationships between entities are known as attributes.

Answer 2

C

Question 3

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

Answer 3

False

Question 4

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 5

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

Question 6

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 7

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

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

Question 8

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

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

Question 9

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 10

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) N:N relationship
C) 1:N relationship
D) 1:1 relationship

Question 11

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 data.
D) It does not describe the relationships among data.

Question 12

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

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

Question 13

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

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

Question 14

The general goal of normalization is to ________.

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

Question 15

A(n)________ notation 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 16

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) identifier
C) attribute
D) entity

Question 17

Normalized tables eliminate ________.

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

Question 18

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

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

Question 19

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

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

Question 20

________ describe the characteristics of entities.

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

Question 21

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

Question 22

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

Question 23

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

Question 24

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

Question 25

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

Question 26

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

Question 27

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

Question 28

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

Question 29

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

Question 30

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

Question 31

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

Question 32

Explain the database development process.

Question 33

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

Question 34

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

Question 35

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

Question 36

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

Question 37

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

Question 38

Entities have attributes that describe characteristics of the entity.

Question 39

Tables that are not normalized can have data integrity problems.

Question 40

Entities have relationships to attributes but not to each other.

Question 41

Explain the role of users in designing a database.

Question 42

Explain the difference between maximum and minimum cardinality.

Question 43

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

Question 44

How is a data model transformed into a database design?