1) Data fragmentation involves decomposing a database into multiple smaller fragments that can be used to reconstruct the original database. 2) There are three types of fragmentation: horizontal, vertical, and mixed. Horizontal fragmentation divides tuples into subsets based on attribute values. Vertical fragmentation divides attributes into different fragments. Mixed fragmentation uses both horizontal and vertical approaches. 3) Fragments can be reconstructed using operations like union for horizontal fragmentation and natural join for vertical fragmentation. Fragmentation aims to improve reliability, allow parallelism for performance, increase efficiency, and enhance security.

1. DATA FRAGMENTATION
PRESENTED BY : SHRADDHA MALVIYA
ROLL-NO : MCA/25018/18

2. FRAGMENTATION
Decomposing a database into multiple smaller units
called fragments , with the help of fragments it is
possible to reconstruct the original database .

3. A RELATION CAN BE FRAGMENTED INTO
THREE WAYS:
• Horizontal fragmentation
• Vertical fragmentation
• Mixed fragmentation

4. HORIZONTAL FRAGMENTATION:-
• A horizontal fragment of a relation is a subset of the
tuples in that relation.
For example:- Employee table
ecode ename esalary ecity
101 abc 30000 Jaipur
102 xyz 40000 Delhi
103 pqr 35000 Jaipur
104 lkm 36000 Pune

5. Create table fragment1 as
select * from employee
where ecity=‘jaipur’;
Create table fragment2 as
Select * from employee
Where ecity=‘delhi’;
Create table fragment3 as
Select * from employee
Where ecity=‘pune’;
ecode ename esalary ecity
101 abc 30000 Jaipur
103 pqr 35000 Jaipur
ecode ename esalary ecity
102 xyz 40000 Delhi
ecode ename esalary ecity
104 lkm 36000 Pune

6. RECONSTRUCTION
• With the help of union operation we can reconstruct the above relation.
Employee-
select * from fragment1
union
select * from fragment2
union
select * from fragment3;

7. VERTICAL FRAGMENTATION
In vertical fragmentation , the fragments are created by
dividing the attribute .
It is more complex then horizontal fragmentation.
For example:
Eid Ename Salary bonus project experience
1 Abc 40000 1000 P1 5
2 Ghi 50000 2000 P3 3
3 xyz 45000 1500 P2 2

8. create table fragment1 as
select eid, ename, salary from employee;
on the basis of basic details
eid Ename salary
1 Abc 40000
2 Ghi 50000
3 xyz 45000
create table fragment 2 as
select eid, bonus, project, experience
from employee;
on the basis of bonus on project
eid bonus project Experience
1 1000 P1 5
2 2000 P3 3

9. RECONSTRUCTION
• With the help of natural join we can reconstruct the
above relation.
select * from
fragment1
natural join
fragment2;

10. MIXED FRAGMENTATION
• A combination of horizontal and vertical
fragmentation.

11. FRAGMENTATION AIMS TO IMPROVE:
• Reliability
• Parallelism
• Efficiency
• Security

12. Thankyou