Question

What is the function of the intersect operation?

(a) It returns the intersection of the results of the results of any two different queries

(b) It returns the intersection of the results of two different queries which have the same set of attributes in the select clause

(c) It returns the intersection of the results of two different queries which have the same condition in the where clause

(d) None of the mentioned

I have been asked this question during an interview for a job.

My doubt is from Set Operations topic in chapter Introduction to Relational Model and Sql of RDBMS

Answer 1

Right answer is (b) It returns the intersection of the results of two different queries which have the same set of attributes in the select clause

Easy explanation: The intersect operation returns the intersection of the results of the results of two different queries which have the same set of attributes in the select clause. It automatically eliminates duplicates.