# BCNF

Date: Fri, 1 Aug 2008 02:45:53 -0700 (PDT)

Message-ID: <1059aabe-e23b-44a3-bb7a-76b7a4d2d5c0@z6g2000pre.googlegroups.com>

Hi all,

**BCNF
**
the following is the definition is the definition of BCNF , which i
saw in a schaum series book

- The relation is 1 N.F
- for every functional dependency of the form X -> A , we have either A C X or X is a super key of r. in other words, every functional dependency is either a trivial dependency or in the case that the functional dependency is not trivial then X must be a super key.

now my questions are as follows

1)

we know that 2-ND normal form is all about separating partial dependencies and full dependencies.third normal form is all about removing transitive dependencies, in these lines can any one give simple/ easy to understand method/explanation for converting a relation in 3rd normal form to BCNF

2) how correct is the following definition of transitive dependencies

transitive dependencies

assume that A,B, and C are the set of attributes of a relation(R).
further assume that the following

functional dependencies are satisfied simultaneously : A -> B , B -/-

*> A, B -> C , and C -/-> A and A -> C*

observe that C -> B is neither prohibited nor required. if all these
conditions are true, we will say that attribute C is transitively
dependent on attribute on A
Received on Fri Aug 01 2008 - 04:45:53 CDT