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Que- R(ABCD) and fds are { A->B ,B->C,C->A} then number of candidate key is........?

Explain please
asked in Databases by Active (2.3k points) | 35 views
IT will be 3 {AD, CD, BD}
Can you please explain??
D is the Multi value Attribute, so it will be in every CK, and From the FD's we can easily see that A, B and C defining each other.

So, CK {AD, BD, CD}.
Thanks bro
y u said d ismultivalued? if any attribute not present in fd that means that attribute is multivalued??

please exlain.

1 Answer

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Best answer

Closure of A ,B and C give = ABC but D is missing so Candidate key will be AD ,BD,CD now we take closure of AD = ABCD , BD = ABCD , CD = ABCDso we get all attributes of Relation so AD is candidate key 

Reference :- Question number 4 http://www.edugrabs.com/questions-on-super-keys-and-candidate-keys/?upm_export=print

answered by Boss (7.3k points)


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