1. Database Normalization
Prepared by: Dr. Samir Tartir

2. Definition
Normalization is the process of removing redundant data from your tables in order to improve:
storage efficiency
data integrity
scalability

3. Goals Eliminating redundant data Ensuring data dependencies make sense
For example, storing the same data in more than one table)
Ensuring data dependencies make sense

4. Motivation Minimize data redundancy
To make database structure flexible
Data should be consistent throughout the database
Insert Anomaly (explained later)
Update Anomaly
Deletion Anomaly
Complex queries required by the user should be easy to handle.

5. Advantages More efficient data structure.
Avoid redundant fields or columns.
More flexible data structure i.e. we should be able to add new rows and data values easily
Better understanding of data.
Ensures that distinct tables exist when necessary.
Close modeling of real world entities, processes and their relationships.

6. Disadvantages
You cannot start building the database before you know what the user needs.
Normalizing the relations to higher normal forms i.e. 4NF, 5NF the performance degrades.
It is very time consuming and difficult process in normalizing relations of higher degree.
Careless decomposition may leads to bad design of database which may leads to serious problems.

7. What is a Normal Form? A set of conditions that data must satisfy
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
Boyce-Codd Normal Form (BCNF)
Fourth Normal Form (4NF)
Fifth Normal Form (5NF)
Sixth Normal form (6NF)