Question

Given two table R1 (x, y) and R2(y, z) with 50 and 30 number of tuples respectively. Find maximum number of tuples in the output of natural join between tables R1 and R2 i.e. R1 * R2? (* - Natural Join)

O 30
O 20
O 40
O 1500

Answer 1

The maximum number of tuples in the output of a natural join between tables R1 and R2 could be 1500, if every row of R1 matches with every row of R2. The 1500 tuples maximum would occur if all the possibilities for matching on the y field are realized.

Step-by-step explanation:

The maximum number of tuples resulting from a natural join of two tables R1(x, y) and R2(y, z), with 50 and 30 tuples respectively, depends on the data in the y columns and how they match up. Assuming that every tuple in R1 matches with at least one tuple in R2 on the y field, the maximum possible number of tuples in the join result is the number of tuples in R1 because each tuple in R1 can join with at least one tuple in R2.

In the provided options, the closest to the rule of natural join would be 50, since it's the count of tuples in R1. However, in a case where the data is such that R1’s tuples match multiple tuples of R2 based on the y field, it's theoretically possible that the number of resulting tuples after the natural join could be as high as the product of the number of tuples in both tables if every tuple of R1 can join with every tuple of R2, which would be 1500 (50 x 30).

Therefore, the maximum number of tuples in the output of the natural join between tables R1 and R2 could be 1500, provided that every tuple in R1 can join with every tuple in R2.