#### WHAT IS NORMALIZATION?

Abhishek Srivasatava

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1. Abhishek Srivasatava

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##### What is normalization?

Normalization :

Normalization is a process of effectively organizing the column and table of a database to reduce data redundancy and improve data integrity.

Normal form of a table

 Prsn_empl_id Prsn_dpnd_id Plan opted 669911 123456 Health , Dental 669901 987415 Vision

1NF

First Normal Form (1NF)

All attributes in a relation must have atomic domains.

In this scheme there should be no repeated element in single block.

For example:

 Prsn_empl_id Prsn_dpnd_id Plan opted 669911 123456 Health 669911 123456 Dental 669901 987415 Vision

2NF

Second Normal Form (2NF)

for implementing this scheme it must satisfied 1st scheme.

Before moving further one should know about the prime attribute and non-prime attribute.

Prime attribute: the entire element which is a part of the prime key.

Non-prime attribute: the entire element which is not part of the prime key.

For this scheme, non prime attribute should be functionally dependent on prime key.

1NF table

 Prsn_empl_id Prsn_dpnd_id Plan opted 669911 123456 Health 669911 123456 Dental 669901 987415 Vision

Modified to 2NF

 Prsn_empl_id Prsn_dpnd_id 669911 123456 669901 987415

 Prsn_empl_id Plan opted 669911 Health 669911 Dental 669901 Vision

3NF

It must satisfy 2NF criteria and there should no relationship between primary key and non primary element data.

For example we have table like this

 Name Addr_id Address type Address A 10 Permanent Abc A 5 Temp Pqr B 10 Permanent Xyz B 5 temp Efg

We can divide above table in two

 Name Addr_id Address A 10 Abc A 5 Pqr B 10 Xyz B 5 Efg

Boyce-Codd Normal Form

It is developed by the Raymond F Boyce.

X Y is a trivial functional dependency (Y X)

X is a super key for schema R

Normal table

 Employee_id Name DOB Car Car_id price 1001 A 12/01/1993 U 997 11M 1002 B 15/01/1993 X 997 12M 1003 C 17/01/1993 Y 997 13M 1004 D 20/01/1993 Z 997 14M

Converting to Boyce-Codd Normal Form

 Employee_id Name DOB 1001 A 12/01/1993 1002 B 15/01/1993 1003 C 17/01/1993 1004 D 20/01/1993

 Car Car_id price U 997 11M X 996 12M Y 995 13M Z 994 14M

 Employee_id Car_iD 1001 997 1002 996 1003 995 1004 994

Modified On Mar-28-2018 11:36:49 PM