0 votes 0 votes how many number of candidate keys in the following relation r = (a, b, c, d, e, h) on which the following functional dependencies hold: {a →bc, c d→ e, e → c,d → aeh,abh→ bd, dh → bc}. what are the candidate keys r? Pun M asked Jun 14, 2017 Pun M 818 views answer comment Share Follow See 1 comment See all 1 1 comment reply akash.dinkar12 commented Jun 14, 2017 reply Follow Share I think 3 candidate keys are there, d, abh, aceh 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes CK are {d, abh and aceh} AnilGoudar answered Jun 14, 2017 AnilGoudar comment Share Follow See all 3 Comments See all 3 3 Comments reply anonymous commented Jun 16, 2017 i reshown Jun 19, 2017 reply Follow Share Why abh a ck? We can derive b from a. 0 votes 0 votes AnilGoudar commented Jun 16, 2017 reply Follow Share Using closure set of abh we can derive all attributes, as abh+ = abhcde 0 votes 0 votes anonymous commented Jun 19, 2017 reply Follow Share abh is a super key. We can derive all attributes using only ah. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes 2 candidate keys D and ah anonymous answered Jun 16, 2017 anonymous comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes [d, abh and aceh] are candidate keys. Candidate keys are those keys which can determine all attribute of a relation.. Naveen Kumar 3 answered Jun 16, 2017 Naveen Kumar 3 comment Share Follow See 1 comment See all 1 1 comment reply abhishekmehta4u commented Jul 7, 2017 reply Follow Share only two candidate keys are possible. D and AH 0 votes 0 votes Please log in or register to add a comment.