4 votes 4 votes If all attributes are prime then the table is in BCNF. Databases database-normalization + – debanjan sarkar asked Oct 17, 2016 debanjan sarkar 1.0k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
11 votes 11 votes no, if all attributes are prime then table is definitely in 3NF but we can't ensure BCNF for BCNF, every one of its dependencies X → Y, at least one of the following conditions hold:[2] X → Y is a trivial functional dependency (Y ⊆ X) X is a super key for schema R even if all the attributes are part of any key attribute(prime-attribute) there is chance that L.H.S of all the FD is not super key let a relation R(ABCD) ABC --> D CD --> A ABC and BCD are CK for this relation but CD is not super key...A.B.C and D all are prime attributes still its not in BCNF cse23 answered Oct 17, 2016 cse23 comment Share Follow See all 2 Comments See all 2 2 Comments reply Digvijay Pandey commented Oct 17, 2016 reply Follow Share Just extra info : If all attribute are prime and every key is simple then it should be in BCNF. 6 votes 6 votes rishu_darkshadow commented Sep 20, 2017 reply Follow Share @ cse23 and Digvijay Pandey X → Y is a trivial functional dependency (Y ⊆ X) according to this, suppose if in any relation CK: ABC and one of FD is : BC->B then here this FD is trivial but still not in BCNF.. plzzz clarify me ... 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes NO . This will clear rule for the 3NF . In BCNF all the left hand side of FDs will be superkeys .then we can surely be in BCNF. Paras Nath answered Dec 12, 2016 Paras Nath comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Relation R(ABCDE) FD : { AB -> C, C->D , D->A} Here A,B,C,D all are prime attribute and R in 3NF Arnab Bhadra answered May 24, 2017 Arnab Bhadra comment Share Follow See all 0 reply Please log in or register to add a comment.