Modern Database Management - Chapter 2

An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n):

composite identifier

The total quiz points for a student for an entire semester is a(n) ________ attribute.

derived

A fact is an association between two or more:

terms

A business rule is a statement of how a policy is enforced or conducted.

FALSE

A cardinality constraint tells what kinds of properties are associated with an entity.

FALSE

A ternary relationship is equivalent to three binary relationships.

FALSE

Most systems developers believe that data modeling is the least important part of the systems development process.

FALSE

Some examples of attributes are: eye_color, weight, student_id, student.

FALSE

The maximum criminality of a relationship is the maximum number of instances of entity B that may be associated with each instance of entity A.

FALSE

The name used for an entity type should never be the same in other E-R diagrams on which the entity appears.

FALSE

The purpose of data modeling is to document business rules about processes.

FALSE

The relationship among the instances of three entity types is called a unary relationship.

FALSE

When systems are automatically generated and maintained, quality is diminished.

FALSE

A good data definition is always accompanied by diagrams, such as the entity-relationship diagram

TRUE

A multivalued attribute may take on more than one value for a particular entity instance

TRUE

A single occurrence of an entity is called an entity instance.

TRUE

An attribute whose values can be calculated from related attribute values is called a derived attribute.

TRUE

An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data.

TRUE

An entity type name should always be a singular noun.

TRUE

Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them

TRUE

Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them.

TRUE

In an E-R diagram, an associative entity is represented by a rounded rectangle.

TRUE

The relationship between the instances of two entity types is called a binary relationship.

TRUE

While business rules are not redundant, a business rule can refer to another business rule

TRUE

Which of the following is NOT a good characteristic of a data name?

Relates to a technical characteristic of the system

An entity type name should be all of the following EXCEPT:

as short as possible

A ________ specifies the number of instances of one entity that can be associated with each instance of another entity

cardinality constraint

An attribute that can be broken down into smaller parts is called a(n) ________ attribute.

composite

Data modeling may be the most important part of the systems development process because:

data characteristics are important in the design of programs and other systems components

An attribute that can be calculated from related attribute values is called a(n) ________ attribute.

derived

The logical representation of an organization's data is called a(n):

entity-relationship model

An entity type whose existence depends on another entity type is called a ________ entity

weak

Which of the following criteria should be considered when selecting an identifier?

All of the above

A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type.

FALSE

A simple attribute can be broken down into smaller pieces

FALSE

It is not permissible to associate attributes with relationships

FALSE

A business rule should be internally consistent

TRUE

A fact is an association between two or more terms.

TRUE

Data modeling is about documenting rules and policies of an organization that govern data

TRUE

Data names should always relate to business characteristics

TRUE

It is desirable that no two attributes across all entity types have the same name

TRUE

One of the roles of a database analyst is to identify and understand rules that govern data.

TRUE

The intent of a business rule is to break down business structure

FALSE

A time stamp is a time value that is associated with a data value.

TRUE

One reason to use an associative entity is if the associative entity has one or more attributes in addition to the identifier

TRUE

Participation in a relationship may be optional or mandatory.

TRUE

Relationships represent action being taken using a verb phrase.

TRUE

When choosing an identifier, choose one that will not change its value often

TRUE

A person's name, birthday, and social security number are all examples of:

attributes

A simultaneous relationship among the instances of three entity types is called a(n) ________ relationship

ternary

In an E-R diagram, there are ________ business rule(s) for every relationship

two

A relationship between the instances of a single entity type is called a(n) ________

unary

An entity that associates the instances of one or more entity types and contains attributes specific to the relationships is called a(n):

associative entity

The number of entity types that participate in a relationship is called the:

degree

A relationship where the minimum and maximum cardinality are both one is a(n) ________ relationship.

mandatory one

Which of the following conditions should exist if an associative entity is to be created?

All of the above.

A business rule is a statement of how a policy is enforced or conducted

FALSE

Which of the following is an entity type on which a strong entity depends?

None of the above

A business rule is a statement that defines or constrains some aspect of the business.

TRUE

Data names do not have to be unique

FALSE

A mutually exclusive relationship is one in which:

an entity instance can participate in only one of several alternative relationships

An entity type on which a strong entity is dependent is called a covariant entity.

FALSE

An example of a term would be the following sentence: "A student registers for a course."

FALSE

Business rules are formulated from a collection of business ramblings

FALSE

In an E-R diagram, strong entities are represented by double-walled rectangles.

FALSE

The degree of a relationship is the number of attributes that are associated with it.

FALSE

Data, rather than processes, are the most complex aspects of many modern information systems.

TRUE

The E-R model is used to construct a conceptual model.

TRUE

The relationship between a weak entity type and its owner is an identifying relationship.

TRUE

Customers, cars, and parts are examples of:

entities

A(n) ________ is the relationship between a weak entity type and its owner

identifying relationship

An attribute of an entity that must have a value for each entity instance is a(n):

required attribute

An attribute that must have a value for every entity (or relationship) instance is a(n):

required attribute

Which of the following is NOT a characteristic of a good business rule?

Inconsistent

A business rule:

all of the above

The common types of entities are:

all of the above

A property or characteristic of an entity type that is of interest to the organization is called a(n):

attribute

Business policies and rules govern all of the following EXCEPT:

managing employees

A student can attend five classes, each with a different professor. Each professor has 30 students. The relationship of students to professors is a ________ relationship.

many-to-many

A good data definition will describe all of the characteristics of a data object EXCEPT:

who can delete the data