Chapter 4 Quiz

Question 1

The CUSTOMER entity includes the attributes CUST_LNAME, CUST_FNAME, CUST_PHONE, and CUST_PHONE_TYPE. The CUST_PHONE_TYPE attribute stores the string “HOME, WORK, MOBILE, OTHER”. Which term best describes CUST_PHONE_TYPE?

Answer 1

multivalued attribute

Question 2

When working with entity relationship models (ERM), which of the following is not a valid statement regarding an entity?
a. In the Chen, Crow’s Foot, and UML notations, an entity is represented by a rectangle that contains the entity name.
b. An entity refers to the entity set and not to a single entity occurrence.
c. An entity is an object of interest to the end designer.
d. The ERM refers to a table row as an entity instance or entity occurrence.

Answer 2

c

Question 3

A derived attribute is an attribute whose value is calculated (derived) from other attributes. What is not an advantage of storing derived attributes in the database?
a. Can keep track of historical data
b. Saves data access time
c. Uses CPU processing cycles
d. Data value is readily available

Answer 3

c

Question 4

A relationship degree indicates the number of entities or participants associated with a relationship. Which is not a valid relationship that’s specifically named?
a. Ternary relationship
b. Quarterly relationship
c. Binary relationship
d. Unary relationship

Answer 4

b

Question 5

Database designers must often compromise design due to conflicting goals. What are examples of contradictory goals in database design?

Answer 5

design standards, processing speed, and information requirements

Question 6

In an entity relationship model (ERM), attributes are characteristics of entities. Which of the following statements best describe an optional attribute?
a. An optional attribute is an attribute that requires a value and can be an optional key.
b. An optional attribute is an attribute that requires a value and can be left empty.
c. An optional attribute is an attribute that does not require a value and can be left empty.
d. An optional attribute is an attribute that does not require a value and can be an optional key.

Answer 6

c

Question 7

What element expresses the specific number of entity occurrences associated with an occurrence of a related entity?

Answer 7

cardinality

Question 8

While a relationship degree indicates the number of entities associated with a relationship, which relationship type is within a single entity type?

Answer 8

recursive

Question 9

What type of entity can exist in the database only when it is associated with another related entity?

Answer 9

existence-dependent

Question 10

What type of attribute allows for no more than one value?

Answer 10

single-valued attribute