Database Questions and Answers–Relational Query Operations and Relational Operators 

This set of Database MCQs focuses on “Relational Query Operations and Relational Operators”.

1. Using which language can a user request information from a database?
a) Query
b) Relational
c) Structural
d) Compiler

2. Student(ID, name, dept name, tot_cred)
In this query which attributes form the primary key?
a) Name
b) Dept
c) Tot_cred
d) ID

3. The _______ provides a set of operations that take one or more relations as input and return a relation as an output.
a) Schematic representation
b) Relational algebra
c) Scheme diagram
d) Relation flow

4. The _______ operator takes the results of two queries and returns only rows that appear in both result sets.
a) Union
b) Intersect
c) Difference
d) Projection

5. A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.
a) Schema diagram
b) Relational algebra
c) Database diagram
d) Schema flow

6. The most commonly used operation in relational algebra for projecting a set of tuple from a relation is____
a) Join
b) Projection
c) Select
d) Union

 7. The _______operation performs a set union of two “similarly structured” tables
a) Union
b) Join
c) Product
d) Intersect

8. The result which operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.
a) Join
b) Cartesian product
c) Intersection
d) Set difference

 9. Student(ID, name, dept name, tot_cred)
In this query which attributes form the primary key?
a) Name
b) Dept
c) Tot_cred
d) ID

10. Which one of the following is a procedural language?
a) Domain relational calculus
b) Tuple relational calculus
c) Relational algebra
d) Query language

 11. Which of these are alternate names for an OLAP Cube? The options in the top row are a and b respecitvely and those in the bottom row are c and d.
a) Cube
b) Multidimensional Cube
c) HyperCube
d) Both (B) and (C)