previous year question

Question

R(A,B,C,D,E,F,G,H)
A->BC
B->CFH
CH->G
E->A
A->EG
what is the number of candidate key

Answer 1

4

AD,BD,ED,FD

Comments

https://gateoverflow.in/1558/gate2013-54  check this  F-> EG  is there you wriiten wrong question

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i think only 2

AD and ED

bcoz D is not in Functional dependency so must included

and if we find AD closure then we get all attributes ,

then we replace A with E (with the help of 4th FD)

now if we see for candidate key of 2 attribute then we unable to find boz only A can determine E and only E can determine A.....

so we check for 3 attribute dependency (here also d must be included ) by excluding E and A then we can't able to find A and E with the help of any combination :((

so only 2 possible