0 votes 0 votes Consider a relation R(A,B,C,D,E) with the following functional dependencies. A→BC C→E B→D E→A The total number of super keys present in the relation are_______ talha hashim asked Sep 21, 2018 talha hashim 974 views answer comment Share Follow See all 5 Comments See all 5 5 Comments reply Show 2 previous comments Deepanshu commented Sep 21, 2018 reply Follow Share it is 28 0 votes 0 votes Magma commented Sep 21, 2018 reply Follow Share YES 28 ... have do some calculation mistakes 0 votes 0 votes smsubham commented Sep 21, 2018 reply Follow Share A, C and E are candidate key. Using the principle of Inclusion-Exclusion we can find the number of the candidate key. $n(A) + n(C) + n(E) - n(A \bigcap C) + n(A \bigcap E) + n(C \bigcap E) + n(A \bigcap C \bigcap E)$ $=> 2 ^{4} + 2 ^{4} + 2 ^{4} - 2 ^{3} - 2 ^{3} - 2 ^{3} + 2 ^{2} = 28$ 0 votes 0 votes Please log in or register to add a comment.
1 votes 1 votes A, C and E are candidate key. Using the principle of Inclusion-Exclusion we can find the number of the candidate key. $n(A) + n(C) + n(E) - n(A \bigcap C) + n(A \bigcap E) + n(C \bigcap E) + n(A \bigcap C \bigcap E)$ $=> 2 ^{4} + 2 ^{4} + 2 ^{4} - 2 ^{3} - 2 ^{3} - 2 ^{3} + 2 ^{2} = 28$ smsubham answered Sep 21, 2018 • edited Sep 21, 2018 by smsubham smsubham comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes = S.K(A) + S.K(C) + S.K(E) - S.K(A $\bigcap$ C) - S.K (C $\bigcap$ E) - S.K(A $\bigcap$ E) + S.K(A $\bigcap$ C $\bigcap$ E) = 24 + 24 + 24 - 23 -23-23 + 22 = 28 Magma answered Sep 21, 2018 Magma comment Share Follow See all 12 Comments See all 12 12 Comments reply Show 9 previous comments Magma commented Sep 21, 2018 reply Follow Share I said this approach is correct mam (3C1) .25−1− (3c2).25−2+ (3C3).25−3 1 votes 1 votes srestha commented Sep 21, 2018 reply Follow Share ok 0 votes 0 votes himgta commented Sep 21, 2018 reply Follow Share @srestha mam.... I got the answer by the another approach but I m not getting urs method to solve the problem...can someone explain? 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes Total superkesys (A U CU E)= 24+24+ 24- 23-23-23+22 = 28 Prince Sindhiya answered Sep 21, 2018 Prince Sindhiya comment Share Follow See all 0 reply Please log in or register to add a comment.