Database chp 2 - test
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.
In the following diagram, which is true?
All of these.
The common types of entities are:
All of these.
Which of the following conditions should exist if an associative entity is to be created?
All of these.
Which of the following criteria should be considered when selecting an identifier?
All of these.
In the following diagram, which is true?
Both Each patient has one or more patient histories and Each patient history belongs to one and only one patient
The following figure shows an example of:
Both Each patient has one or more patient histories and Each patient history belongs to one and only one patient
In the following diagram, which answer is true?
Each employee can supervise one to many employees.
Which of the following is not a suggestion by Salin regarding developing data names?
Keep insignificant or illegal words.
Which of the following is an entity type on which a strong entity depends?
None of these
Which of the following 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
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.
A mutually exclusive relationship is one in which
an entity instance can participate in only one of several alternative relationships.
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 specific 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 person's name, birthday, and social security number are all examples of:
attributes.
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
An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n):
composite identifier
The number of entity types that participate in a relationship is called the
degree
An attribute that can be calculated from related attribute values is called a(n) ________ attribute.
derived
The total quiz points for a student for an entire semester is a(n) ________ attribute
derived
Customers, cars, and parts are examples of:
entities.
The logical representation of an organization's data is called a(n)
entity-relationship model.
A(n) ________ is the relationship between a weak entity type and its owner
identifying relationship
Business policies and rules govern all of the following EXCEPT:
managing employees.
A relationship where the minimum and maximum cardinality are both one is a(n) ________ relationship.
mandatory one
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
An attribute that must have a value for every entity (or relationship) instance is a(n):
required attribute.
Another word for a data definition is a(n)
structural assertion.
A simultaneous relationship among the instances of three entity types is called a ________ relationship.
ternary
A value that indicates the date or time of a data value is called a
time stamp.
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) ________ relationship.
unary
An entity type whose existence depends on another entity type is called a ________ entity.
weak
A good data definition will describe all of the characteristics of a data object EXCEPT
who can delete the data.