Boyce-Codd Normal Form (3.5 NF)

Boyce-Codd Normal Form (3.5 NF).

A database is in BCNF if following conditions met;

  1. It is in 3NF(1NF: no repeating groups, 2NF: Full functional dependency must exist and avoid partial dependency, 3NF: Avoid Transitive Dependency).
  2. For every functional dependency X->Y, X should be the super key of the table (Non-prime attribute never determines prime attribute).

3.5 NF Boyce Codd Normal Form (BCNF) Diagram

Example
For example, we have a table, with some data. The given table is not in BCNF.

Author Nationality Book title Category Number of pages
Author_A Pakistani Data Mining Concepts by T4Tutorials Comedy 700
Author_B Indian Database Systems by T4Tutorials Textbook 350
Author_C American Software Engineering Concepts by T4Tutorials Textbook 300
Author_D American Software Engineering Concepts by T4Tutorials Textbook 300

 

Author Nationality
Author_A Pakistani
Author_B Indian
Author_C American
Author_D American
Book title Category Number of pages
Data Mining Concepts by T4Tutorials Comedy 700
Database Systems by T4Tutorials Textbook 350
Software Engineering Concepts by T4Tutorials Textbook 300

 

Author Book title
Author_A Data Mining Concepts by T4Tutorials
Author_B Database Systems by T4Tutorials
Author_C Software Engineering Concepts by T4Tutorials
Author_D Software Engineering Concepts by T4Tutorials

Exercise 1NF to 5NF

Foreign Key behaving differently on  Cascade strict and SET Null 

Read Tutorials about Normalization in DBMS

  1. First Normal form in DBMS
  2. Second normal form Examples in DBMS
  3. Third normal form
  4. Boyce-Codd Normal Form (3.5 NF)
  5. Fourth Normal Form
  6. Fifth Normal Form (5NF)
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