Normalization

Normalization is the practice of designing database tables so that each fact is stored in exactly one place. If a customer’s address is copied onto every one of their orders, changing it means finding and updating every copy, and missing one leaves the data contradicting itself. Normalizing means splitting that into a customers table and an orders table that points to the customer by ID, then joining them when you need both. The “normal forms” (1NF, 2NF, 3NF and beyond) are increasingly strict rules for spotting that kind of duplication. Teams sometimes deliberately denormalize, copying data back in, to make common reads faster.