Code 301: Class 14 - DB Normalization

Read: Database Normalization Explained in Simple English

Database Normalization process used to organize a database into tables and columns
Tables should be limited to one purpose
Main reasons to normalize
- Minimize duplicate data
- Avoid data modification issues
- Simply queries
Modification Anomaly
- Insert Anomaly when data cannot be inserted unless additional information is gathered
- Update Anomaly when some of a records data is repeated on other rows, forcing multiple updates to effect a single change
- Search and Sort Issues when desirable selection data is potentially present in multiple columns the queries become more cumbersome
Forms of DB Normalization
- 1st (1NF)
  - Info stored in a relational table
  - Each column containing atomic values
  - No repeating groups of columns
- 2nd (2NF)
  - Table in 1st normal form already
  - All columns depend on the tables primary key
- 3rd (3NF)
  - Table is in 2nd normal form already
  - Columns are not transitively dependent on the primary key