GATE | GATE IT 2006 | Question 14
Consider the relations r1(P, Q, R) and r2(R, S, T) with primary keys P and R respectively. The relation r1 contains 2000 tuples and r2 contains 2500 tuples. The maximum size of the join r1⋈ r2 is :
(A) 2000
(B) 2500
(C) 4500
(D) 5000
Answer: (A)
Explanation:
r1⋈ r2 is a join operation done on the common attribute R. Further R is the primary key of R2
When we take a , the value of common attribute( R2 in this case) should match.The value of R in r2 is matched with corresponding R in r1 . So it will have 2000 tuples. So correct option is (A).
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