0 votes 0 votes closed with the note: got R(A,B,C,D) 1. A->B , B->CD 2. A->B , B->C , C->D 3. AB->C , C->AD 4. A->BCD Databases databases + – hem chandra joshi asked Nov 5, 2017 closed Nov 5, 2017 by hem chandra joshi hem chandra joshi 409 views comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes 1. A->B , B->CD : CK : A . It is in 2NF 2. A->B , B->C , C->D : CK : A . It is in 2NF 3. AB->C , C->AD : CK : AB . It is in 2NF 4. A->BCD : CK : A . It is in BCNF Arnab Bhadra answered Nov 5, 2017 Arnab Bhadra comment Share Follow See all 3 Comments See all 3 3 Comments reply hem chandra joshi commented Nov 5, 2017 reply Follow Share https://gateoverflow.in/741/gate2001-2-23 CHECK ABOVE LINK 0 votes 0 votes hem chandra joshi commented Nov 5, 2017 reply Follow Share THAT I LEARN A RELATION IS DEPENDENCY PRESERVING IF F1 U F2 U ...Fn=F WHILE FOR LOSSY F1 ∩ F2 -> F1 OR F1 ∩ F2 ->F2 , WHERE F1 & F2 SHOULD BE CANDIDATE KEY . IS IT RIGHT ? 0 votes 0 votes Arnab Bhadra commented Nov 5, 2017 reply Follow Share Hi, the question you asked and the above gate 2001-2-23 are different. What i interpreted from your question is that FDs are given we have to check which is in BCNF. the gate question is different In options, the decomposed relations are provided and we have to find out which decomposition is in BCNF as well as lossless anf dependency preserving. 0 votes 0 votes Please log in or register to add a comment.