Relational algebra is a relational query language that takes two relations as input and produces another relation as output. It uses fundamental operations like selection, projection, set intersection, and natural join. The selection operation is denoted by and uses predicates in the subscript and relation in parentheses. Set difference is denoted by - and allows finding tuples in one relation not in another. The assignment operator is denoted by <-. Relational algebra includes selection, projection, and aggregation operators but not division. Example queries demonstrate the selection operation on relations to find students by team or fees criteria.
2. 1. Relational Algebra is a __________ query
language that takes two relations as input and
produces another relation as an output of the
query.
a) Relational
b) Structural
c) Procedural
d) Fundamental
3. 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
4. 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)
5. 4. For select operation the ________ appear in
the subscript and the ___________ argument
appears in the parenthesis after the sigma.
a) Predicates, relation
b) Relation, Predicates
c) Operation, Predicates
d) Relation, Operation
6. 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
8. 7. Relational Algebra does not have
A. Selection operator
B. Projection operator
C. Aggregation operator
D. Division operator
9. Given a relation Student(Roll, Name, Class,
Fees, Team) with the following tuples:
Q1. Select all the student of Team A :
10. Given a relation Student(Roll, Name, Class, Fees, Team)
with the following tuples:
Q2. Select all the students of department ECE whose
fees is greater then equal to 10000 and belongs to Team
other than A.
11. Given a relation Faculty (Class, Dept, Position)
with the following tuples:
Q3. Project Class and Dept from Faculty