Question

"bcnf is stronger than 3nf" explain with the help of an example.

Answer 1

A relation R is in 3NF if and only if every dependency A->B satisfied by R meets at least ONE of the following criteria: 1. A->B is trivial (i.e. B is a subset of A) 2. A is a superkey 3. B is a subset of a candidate key BCNF doesn't permit the third of these options. Therefore BCNF is said to be stronger than 3NF because 3NF permits some dependencies which BCNF does not.