Given two union compatible relations R1(A,B) and R2(C,D). What is the result…

The operation is an equijoin of R1 and R2 with the condition R1.A = R2.C and R1.B = R2.D.

• It returns combined tuples from R1 and R2 where both equalities hold.

• Because the attribute names differ (A, B versus C, D), the result includes all attributes from both relations: A, B, C, D.

• This is a specific case of a θ-join (an equijoin) using equality conditions, not a set operation like union or difference.

Why the other listed operations are incorrect:

• Union merges rows from both relations without pairing them by matching attribute values, so it does not enforce the equality conditions shown.

• Cartesian product pairs every row of the first relation with every row of the second and applies no matching condition; the shown operation applies equality filters.

• Set difference returns rows from the first relation that are not in the second; it does not combine rows from both relations based on matching values.

Therefore, none of the named operations match the shown equijoin, so the correct choice is the one that indicates none of the listed operations.