Question

Given relation R(A,B) that has 2 tuples (1, 2) and (3, 4); relation S(B, C, D) has 3 tuples (2, 5, 6), (4, 7, 8) and (9, 10, 11). The natural join of R and S has ______

Select one:
a. 1 tuple (1, 2, 10, 11)
b. 2 tuples (1, 2, 3, 4) and (5, 6, 7, 8)
c. 2 tuples (1, 2, 5, 6) and (3, 4, 7, 8)
d. 2 tuples (1, 2, 2, 5) and (3, 4, 4, 7)

Answer 1

The natural join of relations R and S based on the common attribute B results in 2 tuples, which are the combination of matching tuples from both relations. The correct answer is (1, 2, 5, 6) and (3, 4, 7, 8).

Step-by-step explanation:

The natural join of two relations matches tuples based on their common attributes. In this case, attribute B is common to both relation R(A,B) and relation S(B,C,D). The natural join operation finds matching values in attribute B of both relations and combines the respective tuples into a single tuple in the resulting relation.

To perform the natural join of R and S, we look for tuples in each relation with the same value in attribute B:

• R has (1, 2) and (3, 4).
• S has (2, 5, 6), (4, 7, 8), and (9, 10, 11).

Matching B values are as follows:

• B=2 in R matches B=2 in S.
• B=4 in R matches B=4 in S.

Therefore, the result of the natural join on B will be:

• Combining (1, 2) from R with (2, 5, 6) from S gives us (1, 2, 5, 6).
• Combining (3, 4) from R with (4, 7, 8) from S gives us (3, 4, 7, 8).

Thus, the correct answer is c. 2 tuples (1, 2, 5, 6) and (3, 4, 7, 8).