DESCRIPTION OF NORMALIZATION

1. Normalization
Normalization is the process of designing a data model
to efficiently store data in a database. The end result is
that redundant(Useless or Excessive) data is
eliminated, and only data related to the attribute is
stored within the table.

2. Any person without
knowledge of RDBMS will
create a simple solution to
store the invoice given in
example.

3. The Data stored in above sheet can be stored more correctly as :
But at this stage we found that our sheet contains repeated Data rows, so We will try to
reduce the amount of duplication.

4. First Normal Form:
No Repeating Elements or Groups of
Elements
• At First Step we eliminate the repeated data
from table & the call table in First Normal Form.
Our database schema now
satisfies the two requirements of
First Normal Form: atomicity and
uniqueness. Thus it fulfills the
most basic criterion of a relational

5. Second Normal Form: No Partial
Dependencies
• Table is in 2nd Form if :
– Its in 1st normal form.
– It include no partial dependencies.
• For this purpose take following steps :
– Find & remove fields that are related to only part
of key.
– Group & remove items in another table.

6. So we divide table as
At this step we have Orders table which contains Unique
Order data but order_items still contains repeated data
which can be more normalized …So Tyr to Splite it again…

8. Each order can have many items; each item can belong to many orders.

9. Third Normal Form: No Dependencies
• At last, we return to the problem of the
repeating Customer information. As our
database now stands, if a customer places
more than one order then we have to input all
of that customer's contact information again.
This is because there are columns in the
orders table

10. So We can Split our Orders table as :

11. So Now we can say that :
• each order is made by one, and only one customer;
• each customer can make any number of orders, including zero.

12. And finally, here is what the data in each of the four tables looks like. Notice that NF3
removed columns from a table, rather than rows.

13. Assignments
Project_No Project
Name
Emp_no Emp_Name Rate_cat Rate
P001 MY-SQL On
Linux
E001 Ram A 7500
P001 MY-SQL On
Linux
E002 Shyam B 7000
P001 MY-SQL On
Linux
E006 Tinu C 5000
P002 My MAC OS E001 Ram A 7500
P002 My MAC OS E007 Chinu B 7000