0 votes 0 votes ben10 asked Aug 19, 2018 ben10 554 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes Two minimal covers are possible : A->B, B->C, C->A AND A->C, C->B , B->A Shiv Gaur answered Aug 19, 2018 Shiv Gaur comment Share Follow See all 7 Comments See all 7 7 Comments reply Show 4 previous comments Shaik Masthan commented Aug 20, 2018 reply Follow Share @Shiv Gaur, yes procedure is correct... but my question is A->C, B->C,C->AB A->BC, B->A,C->A ( As Iqra Islam said ) A->B,B->AC,C->B isn't these are minimal? i didn't find any redundant term or FD in that. 0 votes 0 votes Shiv Gaur commented Aug 20, 2018 reply Follow Share I don't know the exact reason but I guess , when we talk about minimal cover of a given FD F, It is a minimal set of FDs that is equivalent to the given FD F. Here {A->C, B->C,C->AB} covers the given F but it could be further split to {A->C, B->C,C->A, C->B} ie 4 FDs and we already have A->B, B->C, C->A and A->C, C->B , B->A ie 3 FDs that's why we split the RHS in first step 0 votes 0 votes Shaik Masthan commented Aug 20, 2018 reply Follow Share @Shiv Gaur, Those are also SHOULD BE minimal covers, note that minimal covers are not unique. compare this in DIGITAL LOGIC all those are irreducible, but which you mentioned are minimal expression but in DBMS we don't have two terminologies... therefore all are minimal covers only 0 votes 0 votes Please log in or register to add a comment.
1 votes 1 votes Two minimal covers are possible. vikas999 answered Aug 19, 2018 vikas999 comment Share Follow See 1 comment See all 1 1 comment reply Shaik Masthan commented Aug 20, 2018 reply Follow Share @vikas999, yes procedure is correct... but my question is A->C, B->C,C->AB A->BC, B->A,C->A A->B,B->AC,C->B isn't these are minimal? i didn't find any redundant term or FD in that. 0 votes 0 votes Please log in or register to add a comment.