Normalization (DK/NF) Anyone ?

Path: emory!sol.ctr.columbia.edu!spool.mu.edu!agate!stanford.edu!rutgers!rochester!cantaloupe.srv.cs.cmu.edu!crabapple.srv.cs.cmu.edu!andrew.cmu.edu!lk1j+ From: lk1j+@andrew.cmu.edu (Lawrence Kim) Newsgroups: comp.databases.informix Message-ID: <MdgX2CO00VpbI0mVYu@andrew.cmu.edu> Date: 2 Mar 92 13:41:34 GMT Organization: Junior, Social & Decision Sciences, Carnegie Mellon, Pittsburgh, PA I realize this may not be the appropriate forum to address my question. If you are offended please disregard this message. Otherwise see if you can help me out. I have this problem I was given. There is a relation X (A,B,C,D,E) With the following dependencies {A,B} --> C,D,E D --> A E --> B Now I am trying to put this in DK normal Form. I am tempted to have these Five Relations relations, R1(A,D) Key : D R2 (E,B) Key : E R3 (A,B,C) Key : {A,B} R4 (A,B,D) Key : {A,B} R5 (A,B,E) Key : {A,B} But I realize there is a problem with R4 and R5, That is they are not in BCNF. This is the case, since D which is a determinant of A is can not be a candidate key. Is there anyway I can transform this relation into DK/NF. Please send answers to my address (lk1j@andrew.cmu.edu) as well as the bboard. Thank You