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R (A, B, C)

Functional dependency= { A -> B, B -> C , C -> A }

No of super keys are...??

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Best answer
4 votes
4 votes
7 all possible combination 2^3 -1 (A,B,C,AB,AC,ABC,BC)
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4 votes

ck for this relation are A,B,C

no. of super key with A= 2^(n-1)= 2^(3-1) = 4

similarly with B again 4 super keys and with C also 4 super keys

with AB it is 2^(n-2) similarly with BC and with CA it is 2^(n-2)

with ABC it will be 2^(n-3)

so,

total no. of super keys= 2^(n-1) + 2^(n-1) + 2^(n-1) - 2^(n-2) -2^(n-2) -2^(n-2) + 2^(n-3)

                                =7 where n=3 which is no.of attributes in relation

edited by
1 votes
1 votes
there are 3 candiadate key a,b,c

so all possible combination will be a,b,c,ab,ac,cb,abc

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