Normalization is the process of simplifying the design of a database. Normalization answers core questions regarding the number of tables required, what each table represents, the number of fields in each table, and the relationship between tables. Normalization also helps avoid redundancy and anomalies in database design. Anomalies can occur while inserting, updating, or deleting records from a database table (if the database is poorly designed). For example, if you have a database table as shown Table 1.1, when a record is updated to change the customer address, all the rows where the customer record exists should be updated. If any rows are missed, then it will lead to data inconsistency. This is called an update anomaly.
|1||921||Ryan||12E West End|
|2||921||Ryan||12E West End|
|3||728||John||44 Avenue Road|
Table 1.1 Sample to Show Update Anomaly