7 7 votes What is the maximum number of possible candidate key for relation on n attributes. Databases + – Aryan Asrafi 7.7k views answer comment Share Follow Print 0 reply Please log in or register to add a comment.
7 7 votes If a table has n attributes, max candidate keys possible = $nC \left ( n/2 \right )$ e.g. for relation R(ABCD) max canndidate keys = 4C2 = 6 CK = {AB, AC, AD, BC, BD, CD} Rakеsh Kumar answered Sep 3, 2016 • edited Sep 3, 2016 by Rakеsh Kumar Rakеsh Kumar comment Share Follow See all 2 Comments 2 2 Comments reply Pavan Kumar Munnam commented Sep 3, 2016 reply Follow flag ABC becomes super key not a candidate key when you consider AC as candidate key 1 1 replyShare Rakеsh Kumar commented Sep 3, 2016 reply Follow flag Correct! Answer edited. 0 0 replyShare Please log in or register to add a comment.
4 4 votes Ans is nC(n/2) When you group the attributes for candidate keys you will get maximum number when they are grouped by n/2 element's Pavan Kumar Munnam answered Sep 3, 2016 Pavan Kumar Munnam comment Share Follow 0 reply Please log in or register to add a comment.
4 4 votes $^{n}C_{\left \lfloor \frac{n}{2} \right \rfloor}$ This is the exact formula. Source: Made easy test series Verified by R a v i n d r a B a b u R a v u l a shashankrustagi answered Oct 28, 2020 shashankrustagi comment Share Follow See all 3 Comments 3 3 Comments reply VYAN_jy commented Oct 16, 2021 reply Follow flag Here ceil and floor do not make any difference. so simply NC(N/2) would be enough. 0 0 replyShare Chandrabhan Vishwa 1 commented Oct 16, 2021 reply Follow flag yes it is correct because 5c2=5c3 due to ncr=nc(n-r) 1 1 replyShare Chandrabhan Vishwa 1 commented Oct 16, 2021 reply Follow flag yes it is correct because 5c2=5c3 due to ncr=nc(n-r) 0 0 replyShare Please log in or register to add a comment.