Chapter 2 Database Management

For the relationship represented in the figure below, which of the following is true?

A department can have more than one employee.

In the figure shown below, which of the following is true?

A person can marry at most one person.

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

Attributes

What criteria should be considered when selecting an identifier?

Choose an identifier that doesn't have large composite attributes.

What software is used to create, maintain, and provide controlled access to databases?

DBMS

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

Derived

In the following diagram, which answer is true?

Each employee can supervise one employee, no employees, or many employees.

In the following diagram, which of the answers below is true?

Each patient has one or more patient histories.

In the figure shown below, which of the following business rules would apply?

Each vendor can supply many parts to any number of warehouses, but need not supply any parts.

A business rule is a statement of how a policy is enforced or conducted. (T/F)

False

A cardinality constraint tells what kinds of properties are associated with an entity. (T/F)

False

A customer can order many items, and an item can be ordered by many customers is an example of a recursive relationship. (T/F)

False

A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type. (T/F)

False

A simple attribute can be broken down into smaller pieces. (T/F)

False

A ternary relationship is equivalent to three binary relationships. (T/F)

False

An entity type on which a strong entity is dependent is called a covariant entity. (T/F)

False

Business rules are formulated from a collection of business ramblings. (T/F)

False

Data names do not have to be unique. (T/F)

False

In the figure below, Name would be an ideal identifier. (T/F)

False

Most systems developers believe that data modeling is the least important part of the systems development process. (T/F)

False

Some examples of attributes are: eye_color, weight, student_id, STUDENT. (T/F)

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. (T/F)

False

The purpose of data modeling is to document business rules about processes. (T/F)

False

The relationship among the instances of three entity types is called a unary relationship. (T/F)

False

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

Identifying Relationship

What is NOT a characteristic of a good business rule?

Inconsistent

What is NOT a good characteristic of a data name?

Relates to a technical characteristic of the system

In the figure below, which attribute is multivalued?

Skill

In the following diagram, what type of relationship is depicted?

Ternary

A fact is an association between two or more terms. (T/F)

True

A multivalued attribute may take on more than one value for a particular entity instance. (T/F)

True

A time stamp is a time value that is associated with a data value. (T/F)

True

An entity type name should always be a singular noun. (T/F)

True

Data modeling is about documenting rules and policies of an organization that govern data. (T/F)

True

Data names should always relate to business characteristics. (T/F)

True

Data, rather than processes, are the most complex aspects of many modern information systems. (T/F)

True

For the relationship represented in the figure below, a department can have more than one employee. (T/F)

True

In an E-R diagram, an associative entity is represented by a rounded rectangle. (T/F)

True

It is desirable that no two attributes across all entity types have the same name. (T/F)

True

Many of the disadvantages of file processing systems can also be limitations of databases. (T/F)

True

Participation in a relationship may be optional or mandatory. (T/F)

True

Relationships represent action being taken using a verb phrase. (T/F)

True

The E-R model is used to construct a conceptual model. (T/F)

True

When choosing an identifier, choose one that will not change its value often. (T/F)

True

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

Weak

In the figure below, which attribute is derived?

Years_Employed

The following figure shows an example of:

a strong entity and its associated weak entity.

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

as short as possible.

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

associative entity.

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

attribute

A ________ defines or constrains some aspect of the business.

business rule

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

cardinality constraint

The following figure shows an example of:

composite attribute

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

composite identifier.

An attribute of an entity that is computed is a(n):

derived attribute.

A single occurrence of an entity type defines:

entity instance

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

entity-relationship model.

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

mandatory one

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

required attribute.

A fact is an association between two or more:

terms

A value that indicates the date or time of a data value is called a:

time stamp

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

two