NORMALIZATION IN RDBMS

NORMALIZATION

Normalization is a process of analysis and organizing data in the database. In this process, reduce the redundancy from relations. Normalization is used to eliminate undesirable features like create, insertion, update, and deletion. It follows some protocols to divide the larger table into the smaller table.

Without Normalization

•      Data take extra memory in the database
•          Difficulty in updating and organizing the data
•          Data redundancy problem

 

TYPES OF NORMALIZATION

1. First Normal form
2. Second Normal form
3. Third Normal form
4. BCNF
5. Fourth Normal form 

FIRST NORMAL FORM

When a table divided into row and column form that break down a table with all repeating group of data eliminated. Example:-

Project number	Project name	Employee number	Employee name	Rate category
P001	Green	E001	Shyam	A
P001	Blue	E002	Ram	B
P001	Green	E006	Satish	C
P002	Yellow	E001	Shyam	A
P002	Yellow	E007	Chavi	B

 In above table few problems:

        Every field contains a duplicate record. It can resolve by normalization.

 A table is in 1^st normal form if:

1. The entire column name in a table should have unique.
2. Data value in a column should be the same type.
3. It should contain a single value in the attribute or column.
4. Order of stored value in a table, does not matter.
5.  All attributes are dependent on a primary key.   

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