1.
DATABASE
NORMALIZATION

2.
WHAT IS NORMALIZATION
A technique of organizing the data into multiple related tables to minimize
DATA REDUNDANCY.
WHAT IS DATA REDUNDANCY AND WHY SHOULD WE REDUCE IT?



TABLE
ROW1
ROW2
ROW3
ISSUES
 Repetition of data increases the size of database.
 Insertion problems
 Deletion problems
 Updation problems

3.
Insertion Anomaly
Roll no Name Branch HOD Office_tel
1 A Jaffna Mr.R 9988
2 B Jaffna Mr.R 9988
3 C Jaffna Mr.R 9988
4 D Jaffna Mr.R 9988
To insert redundant data for every new
row (of student data in our case)is a
data insertion problem

4.
Deletion Anomaly
Roll no Name Branch HOD Office_tel
1 A Jaffna Mr.R 9988
2 B Jaffna Mr.R 9988
3 C Jaffna Mr.R 9988
4 D Jaffna Mr.R 9988
Loss of a related dataset when some
other dataset is deleted.

5.
Updation Anomaly
Roll no Name Branch HOD Office_tel
1 A Jaffna Mr.R Mr.Y 9988
2 B Jaffna Mr.R Mr.Y 9988
3 C Jaffna Mr.R 9988
4 D Jaffna Mr.R Mr.Y 9988

6.
How normalization will solve all these
problems?
Roll no Name Branch HOD Office_tel
Roll no Name Branch Branch HOD Office_tel
Branch HOD Office_tel
Jaffna Mr.Y 9988
Roll no Name Branch
1 A Jaffna
2 B Jaffna
Not eliminating redundancy but minimizing
data redundancy.

7.
Type of Normalization
 1st Normal Form
 2nd Normal Form
 3rd Normal Form
 BCNF(boyce-codd normal form)

8.
1st Normal Form (1NF)
There are 4 basic rules that a table should follow to be in 1st Normal form
Rule 1
A X,Y
B W,X
C Y
D Z
 Each column should
contain atomic values.
 Entries like XY and WX
violate this rule.
26.10.89 X
13.2.99 W
22.4.85 Y
D 01.2.93
4 A B
2 C D
3 E F
1 G H
DOB Name
Rule 2 Rule 3 Rule 4
 A column should contain
values that are of the
same type.
26.10.89 X E
13.2.99 W F
22.4.85 Y G
2.3.21 A B
Name Name
 Each column should
have a unique name
 Order in which data is
saved doesn’t matter

9.
Eg:
Branch_No BranchAddress TelNo
B001 Jaffna 0212229847,0212225848
B002 Nallur 0774512456,0765421456
B003 Kondavil 0215555789
B004 Chavakacheri 0758984566
BranchNo BranchAddress
B001 Jaffna
B002 Nallur
B003 Kondavil
B004 Chavakacheri
Branch_No TelNo
B001 0212229847
B001 0212225848
B002 0774512456
B002 0765421456
B003 0215555789
B004 0758984566
Method 2
Branch_No BranchAddress TelNo
B001 Jaffna 0212225848
B001 Jaffna 0212229847
B002 Nallur 0774512456
B002 Nallur 0765421456
B003 Kondavil 0215555789
B004 Chavakacheri 0758984566
Method 1
Method 2

10.
2nd Normal Form (2NF)
1NF
No Partial dependency
rules
A B
1 2
2 1
3 3
4 4
5 5
A B

11.
3rd Normal Form (3NF)