0 votes 0 votes Deepalitrapti asked Aug 19, 2018 Deepalitrapti 290 views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply Shaik Masthan commented Aug 19, 2018 reply Follow Share i hope E can match either A or B but only one attribute generally, AB combinely form key means there are some duplicates in A and some duplicates in B but when we take combinely there is no duplicate combination of (A,B) therefore Foreign key can not possible for the attribute which has duplicates 0 votes 0 votes Bhagyashree Mukherje commented Aug 19, 2018 reply Follow Share @Shaik Masthan if we are told in a question that we can have E and F attribute of relation S, then can we have foreign key reference to R? I mean is it dependent on the number of columns? 0 votes 0 votes Shaik Masthan commented Aug 19, 2018 reply Follow Share as per my knowledge, we can have E and F attribute of relation S, then can we have foreign key reference to R yes... 0 votes 0 votes Bhagyashree Mukherje commented Aug 19, 2018 reply Follow Share Ok thanks 0 votes 0 votes Please log in or register to add a comment.