SQL
October 4, 2023SQL
October 4, 2023SQL
Question 11
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Given relations r(w, x) and s(y, z), the result of
select distinct w, x from r, s
is guaranteed to be same as r, provided
r has no duplicates and s is non-empty
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r and s have no duplicates
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s has no duplicates and r is non-empty
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r and s have the same number of tuples
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Question 11 Explanation:
r has no duplicate, if r can have duplicates it can be remove in the final state. s in non-empty if s is empty then r*s becomes empty.
Correct Answer: A
Question 11 Explanation:
r has no duplicate, if r can have duplicates it can be remove in the final state. s in non-empty if s is empty then r*s becomes empty.
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