I have a little problem with a normalization exercise. I have the following relation:
R = {L,K,D,S,O,W} which presents the functional dependencies (FD) shown below:
F = { {D,S,K} -> {O}, {O} -> {K}, {O,L} -> {W} {W,L,K} -> {O}, {D,S,W} -> {L}} I have to determine what normal form (NF) is satisfies. So I started from determining the candidate keys; they are:
{D,S,O,L} {D,S,L,K} {D,S,K,W} {D,S,O,W} Then, I worked from-top-to-bottom (not sure if it is good strategy).
This relation isn't in BCNF because the left side of every FD does not contain key(s) e.g.
{O} -> {K}My definition for 3NF was that, for every nontrivial, simple FD, the left side contains a key or the right side is part of a key (or it is a key). Everything matches and I thought that the relation
Ris in 3NF.
Then I look on the conditions to be in 2NF and saw that:
This relation contains partial dependency e.g.
{O} -> {K}This relation contains transitive dependency.
Transitive dependency is for every FD X -> A, X is a subset or superset of the key (is that right, but if X is a subset of the key then this is a partial dependecy)?
This dependency doesn't work for me {W,L,K} -> {O} - this is transitive. So, is relation R in 1NF? This is something weird, either I have a bad definition of 3NF or this relation is in 3NF... but it isn't in 2NF, which is impossible. What's wrong?
