Intro to DBMS

Boyce Codd Normal Form (BCNF)

BCNF is extension of 3NF. It is stricter than 3NF. According to Boyce Codd normal form (BCNF),

  1. For BCNF, the table should be in 3NF.
  2. For every FD, L.H.S. should be a candidate or super key.

Example: Let’s assume the following student table

The above table holds the following Candidate keys and FD’s

  • Candidate key = {RollNo, ID_Card}
  • FD = {RollNo → Name, RollNo→ ID_Card,  ID_Card → age, ID_Card → RollNo}

The L.H.S. of all the above functional dependencies contains a candidate key or super key. So, the above table is in BCNF.