DB Normalization
Data Normalization¶
DB Normalization is a technique that detects degree of redundancy(needless) of data in a database.
Normal Forms¶
- 1NF (First Normal Form)
- 2NF (Second Normal Form)
- Rule 1- Be in 1NF
- Rule 2- Single Column Primary Key that does not functionally dependant on any subset of candidate key relation
- In the above Image the pk for mentor_sessions table is st_id, m_id and s_date and feedback col depends on all pk and m_name only depends on m_id hence its not complying with 2nf.
- 3NF (Third Normal Form)
- 3.5NF - BCNF (Boyce-Codd Normal Form)
- 4NF (Fourth Normal Form)
- 5NF (Fifth Normal Form)
- 6NF (Sixth Normal Form)