Chapter 3-4

Question 1

_____ expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.

a) Relationship
b) Connectivity
c) Dependence
d) Cardinality

Answer 1

d) Cardinality

Question 2

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities.

a) M:N
b) N:1
c) 1:M
d) M:1

Answer 2

a) M:N

Question 3

An entity in the entity relationship model corresponds to a table in the relational environment.

A) True
B) False

Answer 3

A) True

Question 4

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

A) True
B) False

Answer 4

A) True

Question 5

The DIVIDE operation uses one single-column table (e.g., column “a”) as the divisor and one two-column table (e.g., columns “a” and “b”) as the dividend.

A) True
B) False

Answer 5

A) True

Question 6

The SELECT operator yields a vertical subset of a table.

A) True
B) False

Answer 6

B) False

Question 7

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

A) True
B) False

Answer 7

A) True

Question 8

In the entity relationship diagram (ERD), cardinality is indicated using the _____ notation, where max is the maximum number of associated entities and min represents the minimum number of associated entities.

a) (max, min)
b) (min, max)
c) [min … max]
d) {min|max}

Answer 8

b) (min, max)

Question 9

Each table _____ represents an attribute.

a) column
b) row
c) value
d) dimension

Answer 9

a) column

Question 10

_____ are especially useful when you are trying to determine what values in related tables cause referential integrity problems.

a) Equijoins
b) Inner joins
c) Outer joins
d) Theta joins

Answer 10

c) Outer joins

Question 11

A(n) _____ is an orderly arrangement used to logically access rows in a table.

a) relationship
b) superkey
c) index
d) primary rule

Answer 11

c) index

Question 12

According to Codd’s _____ rule of relational database, “Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns).”

a) nonsubversion
b) integrity independence
c) logical data independence
d) comprehensive data sublanguage

Answer 12

c) logical data independence

Question 13

A _____ is any key that uniquely identifies each row.

a) superkey
b) special key
c) candidate key
d) foreign key

Answer 13

a) superkey

Question 14

The row’s range of permissible values is known as its domain.

A) True
B) False

Answer 14

B) False

Question 15

The DIFFERENCE operator subtracts one table from the other.

A) True
B) False

Answer 15

A) True

Question 16

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

A) True
B) False

Answer 16

B) False

Question 17

Connectivities and cardinalities are established by concise statements known as business rules.

A) True
B) False

Answer 17

A) True

Question 18

In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable.

a) indexes
b) relations
c) logical structures
d) keys

Answer 18

d) keys

Question 19

In Chen notation, there is no way to represent cardinality.

A) True
B) False

Answer 19

B) False

Question 20

The _____ relationship should be rare in any relational database design.

a) M:1
b) 1:1
c) 1:M
d) M:N

Answer 20

b) 1:1

Question 21

The idea of determination is unique to the database environment.

A) True
B) False

Answer 21

B) False

Question 22

The entity relationship model (ERM) is dependent on the database type.

A) True
B) False

Answer 22

B) False

Question 23

When using the Crow’s Foot notation, the associative entity is indicated by _____ relationship lines between the parents and the associative entity.

a) triple
b) double
c) dotted
d) solid

Answer 23

d) solid

Question 24

When you define a table’s primary key, the DBMS automatically creates a(n) _____ index on the primary key column(s) you declared.

a) primary
b) key
c) composite
d) unique

Answer 24

d) unique

Question 25

To implement a small database, a database designer must know the “1” and the “M” sides of each relationship and whether the relationships are mandatory or optional.

A) True
B) False

Answer 25

A) True