Database Questions and Answers – Relational Algebra

This set of Database Questions & Answers focuses on “Relational Algebra”

1. Relational Algebra is a __________ query language that takes two relation as input and produces another relation as output of the query.
a) Relational
b) Structural
c) Procedural
d) Fundamental
View Answer

Answer:c
Explanation:This language has fundamental and other operations which are used on relations .

2. Which of the following is a fundamental operation in relational algebra ?
a) Set intersection
b) Natural join
c) Assignment
d) None of the mentioned
View Answer

Answer:d
Explanation:The fundamental operations are select, project, union, set difference, Cartesian product, and rename.

3. Which of the following is used to denote the selection operation in relational algebra ?
a) Pi (Greek)
b) Sigma (Greek)
c) Lambda (Greek)
d) Omega (Greek)
View Answer

Answer:b
Explanation:The select operation selects tuples that satisfy a given predicate.

4. For select operation the ________ appear in the subscript and the ___________ argument appears in the paranthesis after the sigma.
a) Predicates, relation
b) Relation, Predicates
c) Operation, Predicates
d) Relation, Operation
View Answer

Answer:a
Explanation:None.

5. The ___________ operation, denoted by −, allows us to find tuples that are in one relation but are not in another.
a) Union
b) Set-difference
c) Difference
d) Intersection
View Answer

Answer:b
Explanation:The expression r − s produces a relation containing those tuples in r but not in s.

6. Which is a unary operation:
a) Selection operation
b) Primitive operation
c) Projection operation
d) Generalized selection
View Answer

Answer:d
Explanation:Generalization Selection takes only one argument for operation.

7. Which is a join condition contains an equality operator:
a) Equijoins
b) Cartesian
c) Natural
d) Left
View Answer

Answer:a
Explanation:None.

8. In precedence of set operators the expression is evaluated from
a) Left to left
b) Left to right
c) Right to left
d) From user specification
View Answer

Answer:b
Explanation:The expression is evaluated from left to right according to the precedence.

9. Which of the following is not outer join ?
a) Left outer join
b) Right outer join
c) Full outer join
d) All of the mentioned
View Answer

Answer:d
Explanation:The FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins.

10. The assignment operator is denoted by
a) ->
b) <-
c) =
d) ==
View Answer

Answer:b
Explanation:the result of the expression to the right of the ← is assigned to the relation variable on the left of the ←.

Sanfoundry Global Education & Learning Series – Database Management System.

If you liked this Database MCQ, kindly share, recommend or like below!

About

Manish Bhojasia, a technology veteran with 17+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer and SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage & Cluster Administration, Advanced C Programming, SAN Storage Technologies, SCSI Internals and Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him below.


Sanfoundry Training Center of Excellence (CoE)

Manish Bhojasia, a technology veteran with 17+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer and SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage & Cluster Administration, Advanced C Programming, SAN Storage Technologies, SCSI Internals and Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him below.







Sanfoundry Internships
Subscribe Newsletter & Posts
Follow Manish & Sanfoundry