Normalization organizes relational data into smaller tables, each representing one entity or concept. It reduces redundancy, limits dependency, and strengthens data integrity and consistency before SQL implementation. section 3.10 section 6.2
Splitting mixed data
A product_review table stores information about both products and reviews. Because one table represents more than one entity, repeated product data and update anomalies can occur. Normalize it by separating the data into product and review tables. section 3.10
Use normal forms as sequential guidelines:
- 1NF, 2NF, 3NF, and BCNF build hierarchically, with each form extending the preceding one. section 6.2
- A BCNF table has a primary key, no multivalued columns, columns dependent on a key and nothing else, and no transitive dependency. section 6.2
- Normalization relies on superkeys, candidate keys, and primary keys: a candidate key is a minimal superkey, and one candidate key becomes primary. section 6.2
