Database Chapter 2

Structural assertion

Another word for a data definition is a(n)

derived

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

all of these

Which of the following conditions should exist if an associative entity is to be created? All the relationships for the participating entities are many-to-many. The new associative entity has independent meaning. The new associative entity participates in independent relationships. All of these.

all of these

Which of the following criteria should be considered when selecting an identifier? Choose an identifier that is stable. Choose an identifier that will not be null. Choose an identifier that doesn't have large composite attributes. All of these.

Relates to a technical characteristic of the system

Which of the following is NOT a good characteristic of a data name? Relates to business characteristics Readable Repeatable Relates to a technical characteristic of the system

None of these

Which of the following is an entity type on which a strong entity depends? Owner Member Attribute None of these

Keep insignificant or illegal words

Which of the following is not a suggestion by Salin regarding developing data names? Prepare a definition of the data. Keep insignificant or illegal words. Arrange the words in a meaningful, repeatable way. Assign a standard abbreviation for each word.

Cardinality constraint

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

who can delete the data

A good data definition will describe all of the characteristics of a data object EXCEPT: subtleties. examples. who determines the value of the data. who can delete the data.

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

A mutually exclusive relationship is one in which: an entity instance can participate in many different relationships. an entity instance can participate in only one of several alternative relationships. an entity instance can not participate in a relationship with another entity instance. None of these.

attributes

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

attribute

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

unary

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

mandatory one

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

ternary

A simultaneous relationship among the instances of three entity types is called a ________ relationship.

many-to-many

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.

time stamp

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

identifying relationship

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

composite

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

derived

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

required attribute

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

composite identifier

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

associative entity

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

as short as possible

An entity type name should be all of the following EXCEPT: concise. specific to the organization. as short as possible. a singular noun.

weak

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

managing employees

Business policies and rules govern all of the following EXCEPT: managing employees. creating data. updating data. removing data.

entities

Customers, cars, and parts are examples of:

two

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

All of these.

The common types of entities are: strong entities. weak entities. associative entities. All of these.

entity-relationship model.

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

degree.

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