Database Management Systems (3130703) MCQs

MCQs of Relational Query Languages

Showing 1 to 10 out of 40 Questions
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1.

In the relational modes, cardinality is termed as

(a)

Number of tuples
(b)

Number of attributes
(c)

Number of tables
(d)

Number of constraints
Answer:

Option (a)

2.

A candidate key must satisfy all of the following conditions EXCEPT

(a)

The key must uniquely identify the row
(b)

The key must indicate the row's position in the table
(c)

The key must be nonredundant
(d)

Each nonkey attribute is functionally dependent
Answer:

Option (b)

3.

A super key is any key that uniquely identifies each ________ uniquely.

(a)

Records
(b)

Object in a table
(c)

Table
(d)

Structure in a table
Answer:

Option (a)

4.

Which of the following statements concerning the primary key is true?

(a)

The primary key may be null
(b)

The primary key is not required for all tables
(c)

All primary key entries are unique
(d)

For every primary key there must be a foreign key
Answer:

Option (c)

5.

A super key that does not contain a subset of attributes that is itself a super key is called a _________

(a)

Candidate key
(b)

Primary key
(c)

Super key
(d)

Secondary key
Answer:

Option (a)

6.

Which of the following Relational Algebra operations require that both tables (or virtual tables) involved have the exact same attributes/data types?

(a)

Join, Projection, Restriction
(b)

Multiplication and Division
(c)

Union, Intersection, Minus
(d)

Minus, Multiplication, Intersection
Answer:

Option (c)

7.

A Relational operator that yields all possible pairs of rows from two tables is known as a/an ____________

(a)

Intersect
(b)

Difference
(c)

Project
(d)

Cross Product
Answer:

Option (d)

8.

If k is a Primary key in a relation R1, then

(a)

Every tuple of R1 has a distinct value for K
(b)

K can have a null value for tuples in R1
(c)

K must be a key for some other relation
(d)

K is a foreign key for R1
Answer:

Option (a)

9.

A __________ is an attribute in relation of a database that serves as the primary key of another relation in the same database.

(a)

Composite Key
(b)

Foreign Key
(c)

Primary Key
(d)

Unique Key
Answer:

Option (b)

10.

Any set of attributes that uniquely identifies each tuple in a relation is termed as _________

(a)

Foreign key
(b)

Super key
(c)

Check key
(d)

Alternate key
Answer:

Option (b)

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