Normalization was introduced in RDBMS by IBM, and the use 
of normalization is to check the database consistency of a 
table.There are three types of normalization forms 
1 First normalization
2.second normalization
3. third normalization

Murlaidharan 
dharanmu@yahoo.com

Normalization is the process of removing redundant data and
avoiding anomalies due to updates and delete.

Normalization is the process of designing a datamodel and 
effociently store the data in a database. to reduce the 
redundecny.

Normalization is the process of designing a datamodel and 
effociently store the data in a databaseFirst normal form 
(1NF) lays the groundwork for an organised database design:
Ensure that each table has a primary key: minimal set of 
attributes which can uniquely identify a record.

Eliminate repeating groups (categories of data which would 
seem to be required a different number of times on 
different records) by defining keyed and non-keyed 
attributes appropriately.

Atomicity: Each attribute must contain a single value, not 
a set of values.

'First normal form' depends on functional dependency 
formula f(x)=y. For every value of x there is value for y.
Second normal form
Second normal form (2NF) If a table has a composite key, 
all attributes must be related to the whole key:
The database must meet all the requirements of the first 
normal form.
The relational schema should not have any partial 
functional dependency i.e. No proper subset of the primary 
key should derive a functional dependency belonging to the 
same schema. For example, consider functional dependencies 
FD:{AB->C, A->D, C->D} here AB is the primary key, as A->D 
this relational schema is not in 2NF.
Third normal form
Third normal form (3NF) requires that data stored in a 
table be dependent only on the primary key, and not on any 
other field in the table.
The database must meet all the requirements of the first 
and second normal form.
All fields must be directly dependent on the primary key 
field. Any field which is dependent on a non-key field 
which is in turn dependent on the Primary Key (ie a 
transitive dependency) is moved out to a separate database 
table.