Normalization is basically; a process of efficiently organizing data in a database. There are two goals of the normalization process: eliminate redundant data (for example, storing the same data in more than one table) and ensure data dependencies make sense (only storing related data in a table). Both of these are worthy goals as they reduce the amount of space a database consumes and ensure that data is logically stored.
Normalization Avoids (Why used):
- Duplication of Data – The same data is listed in multiple lines of the database
- Insert Anomaly – A record about an entity cannot be inserted into the table without first inserting information about another entity – Cannot enter a customer without a sales order
- Delete Anomaly – A record cannot be deleted without deleting a record about a related entity. Cannot delete a sales order without deleting all of the customer’s information.
- Update Anomaly – Cannot update information without changing information in many places. To update customer information, it must be updated for each sales order the customer has placed
Normalization Process (How):
Normalization is a three stage process – After the first stage, the data is said to be in first normal form, after the second, it is in second normal form, after the third, it is in third normal form. Each normalized form has certain requirements or conditions, which must be fulfilled. If a table or relation fulfills any particular form then it is said to be in that normal form. The process is applied on each relation of the database. The minimum form in which all the tables are in is called the normal form of entire database. The main objective of normalization is to place the database in highest form of normalization.
