WebCT Assignment #2
1.
Data modeling may be the most important part of the systems development process
because:
a)
It is the easiest
b)
Data are less stable than processes.
c)
Data characteristics are important in the design of programs and other
systems components
d)
The data in a system are generally less complex than processes, and play a
central role in development
2.
3.
A business rule:
a)
Defines or constrains some aspect of the business
b)
Asserts business structure
c)
Controls or influence the behavior of the business
d)
All of the above
Business rules should be determined primarily by interviewing executives in the
business.
a)
True
b)
False
REASON:
Business rules should be determined from many sources, including
policies, manuals, contracts, and brochures.
4.
5.
The common types of entities are:
a)
Strong entities
b)
Weak entities
c)
Associative entities
d)
All of the above
A property or characteristic of an entity type that is of interest to the organization is
called a(n):
a)
Relationship
b)
Cross-function
c)
Coexisting entity
d)
6.
attribute
A relationship is an association between attributes.
a)
True
b)
False
REASON:
7.
A good data name should be:
a)
Readable, repeatable and technical
b)
Meaningful, technical, and unique
c)
Repeatable, short, and meaningful
d)
readable, unique, and repeatable
REASON:
8.
A relationship is an association between entity types.
These are just a few of the characteristics of a good data name.
A multivalued attribute is an attribute that is common to many entities.
a)
True
b)
False
REASON:
A multivalued attribute is an attribute that may take on more than one
value for a given entity instance.
9.
10.
The following figure shows an example of:
a)
A strong entity and its associated weak entity
b)
A one-to-many relationship
c)
A co-dependant relationship
d)
A double-walled relationship
A person's name, birthday, and social security number are all examples of:
a)
Entities
b)
Descriptors
c)
Relationships
d)
11.
12.
Attributes
A(n) _____ is the relationship between a weak entity type and its owner.
a)
associative entity
b)
jump path
c)
chain link
d)
identifying relationship
The _____ specifies the number of instances of one entity that can (or must) be
associated with each instance of another entity.
a)
multivalued attribute
b)
entity instance
c)
cardinality constraint
d)
associative entity
REASON:
13.
A minimum or maximum cardinality may be defined for relationships.
The degree of a relationship is the number of entity types that participate in a
relationship.
a)
True
b)
False
REASON:
The three most common relationship degrees are unary, binary, and
ternary.
14.
A ternary relationship is a simultaneous relationship between more than three entity
types.
a)
True
b)
False
REASON:
A ternary relationship is a simultaneous relationship among only three
entity types.
15.
Which is NOT a basic construct of an E-R model?
a)
Attributes
b)
Entity types
c)
Identifiers
d)
Relationships
REASON:
16.
The basic constructs are relationships, entity types, and attributes.
In the following figure "address" is an example of:
17.
a)
A relational attribute
b)
A multivalued attribute
c)
A derived attribute
d)
A composite attribute
An example of a multivalued attribute might be:
a)
Student_GPA
b)
ID_Number
c)
Student_Address
d)
College_Degree
REASON:
18.
College_Degree might have multiple values for an individual.
An attribute that can be calculated from related attribute values is called a _____
attribute.
19.
a)
multivalued
b)
composite
c)
simple
d)
derived
An attribute that uniquely identifies an entity, and consists of a composite attribute is
called a(n):
20.
a)
Composite attribute
b)
Composite identifier
c)
Identifying attribute
d)
Relationship identifier
An entity that associates the instances of one or more entity types and contains
attributes specific to the relationships is called a(n):
21.
22.
a)
Associative entity
b)
Connecting entity
c)
Intersectional entity
d)
All of the above
The number of entity types that participate in a relationship is called the:
a)
Identifying characteristic
b)
Degree
c)
Counter
d)
Number
A relationship between the instances of a single entity type is called a _____
relationship.
23.
24.
a)
Ternary
b)
Binary
c)
Primary
d)
Unary
An entity type name should always be a singular noun.
a)
True
b)
False
A simultaneous relationship among the instances of three entity types is called a _____
relationship.
25.
a)
binary
b)
primary
c)
ternary
d)
tertiary
In the figure
shown below, which
of the following is
true?
a)
A person can marry only one person
b)
A person can marry more than one person, but that person can only be married
to one person
26.
c)
A person can marry more than one person
d)
A person has to be married
A _____ specifies the number of instances of one entity that can be associated with
each instance of another entity.
27.
a)
Cardinality constraint
b)
Degree
c)
Limit
d)
Counter constraint
A relationship where the minimum and maximum cardinality are both one is a(n) _____
relationship.
28.
a)
Optional
b)
Mandatory one
c)
Mandatory link
d)
Unidirectional
For the relationship represented in the figure below, which of the following is true?
a)
An employee can work for more than one department but does not have to work
for any departments
29.
b)
A department can have more than one employee
c)
An employee has to work for more than one department
d)
A department must have at least one employee
In the figure shown below, which of the following business rules would apply?
a)
Each vendor can supply many parts to any number of warehouses, but
need not supply any parts
b)
Each part must be supplied by exactly one vendor to any number of
warehouses.
c)
Each warehouse can be supplied with any number of parts from more than one
vendor, and each warehouse could be supplied with no parts
d)
30.
None of the above
A mutually exclusive relationship is one in which:
a)
An entity instance can participate in many different relationships
b)
An entity instance can participate in only one of several alternative
relationships
c)
An entity instance can not participate in a relationship with another entity
instance
d)
31.
None of the above
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.
32.
33.
a)
One-to-one
b)
Strong
c)
One-to-many
d)
Many-to-many
The total quiz points for a student for an entire semester is a(n) _____ attribute.
a)
Stored
b)
Derived
c)
Mixed
d)
Addressed
In the figure below, which attribute is multi-valued?
a)
Years_Employed
b)
Employee_ID
c)
Address
d)
Skill