Consider the following relations X(S, Si, C) and Y(S, P, D) . Number of tuples…
2023
Consider the following relations X(S, Si, C) and Y(S, P, D) .
Number of tuples by applying right outer join on relation X and Y is / are :
- A.
16
- B.
5
- C.
3
- D.
4
Attempted by 332 students.
Show answer & explanation
Correct answer: D
Answer: 4 tuples. A right outer join returns all rows from the right relation and the matching rows from the left relation; unmatched right-side rows appear with NULLs for left-side attributes.
Relation X has S values: J, B, R, T (4 rows).
Relation Y has S values: J, B, R, A (4 rows).
Matching S values are J, B, R — these produce 3 joined rows.
S value A in the right relation has no match in X, so it contributes one additional row with NULLs for X's attributes.
Total tuples = 3 matched + 1 unmatched from the right relation = 4.
Note: The unmatched tuple T in X is not included because this is a right outer join (rows from the right relation are preserved).
A video solution is available for this question — log in and enroll to watch it.