Database normalization is the process of structuring the tables in a relational database so that each fact is stored in exactly one place. It removes the redundancy that leads to update, insert and delete anomalies. In this short lecture I walk through the normal forms one by one, from first normal form up to sixth, with examples of what each one fixes.

Topics covered

  • First normal form (1NF)
  • Second normal form (2NF)
  • Third normal form (3NF)
  • Boyce–Codd normal form (BCNF)
  • Fourth normal form (4NF)
  • Fifth normal form (5NF)
  • Sixth normal form (6NF)

Video (in Bulgarian)

Drawing

Hand-drawn diagram of the database normal forms, from first to sixth