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Every n-1 attributes of relation R is a candidate key . How many superkey are possible .please any one explain it.

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Please let me know if there is any calculation mistake

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number of ways possible to select (n-1) distinct keys from set of 'n' attribute is = nCn-1 = nC1 =n

therefore number of candidate keys with size (n-1) = n

and the whole 'n' attribute together can also act as superkey therefor total number of superkey = N+1.

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