1. PGT Computer Science Question Discussion

1. PGT Computer Science Question Discussion

Given two R union compatible relation R1 (A, B) and R2 (C, D) what is the result of the operation

 

R1 ⋈ (A=C∧B=D) R2?

 

a) R1⋃R2 b) R1 ⨯ R2 c) R1 – R2 d) R1 ∩R2

Explanation

 

Here ⋈ is a conditional join i.e. inner join with the condition A=C∧B=D

Here we have two relations R1(A,B) and R2 (C,D) and in condition we mentioned that first column of R1 is equal to the first column of R2 and second column of R1 is equal to the second column of R2 means we are checking equal to condition and here also we have "AND" operator, You should know that "AND" operator represent intersection

 So option (D) is the correct ans