What is Data Integrity and Normalization? How it can be used to bring the database in a consistent state? Express graphically.
The process of producing a simpler and more reliable database structure is called normalization. It is used to create a suitable set of relations for storing data. This process works through different stages known as normal forms. These stages are 1NF, 2NF, 3NF etc.
Figure 4.2: Graphical Representation of Normalization Process
Each normal form has certain requirements or condition. These conditions must be fulfilled to bring the database in that particular normal form. If a relation satisfies the conditions of a normal form, it is said to be in that normal form.
The task of database design starts with un-normalized set of relations. Normalization process identifies and corrects problems and complexities of database design. It produces a new set of consistent relations. The new design is as free of processing problems as possible.