This document discusses database fragmentation in distributed database management systems (DDBMS). Database fragmentation allows a single database object to be broken into multiple segments that can be stored across different sites on a network. This improves efficiency, security, parallelism, availability, reliability and performance. There are three main types of fragmentation: horizontal, vertical, and mixed. Horizontal fragmentation breaks data by attributes like location, vertical by attributes like departments, and mixed uses both. While fragmentation provides advantages, it also increases complexity, cost, and makes security and integrity control more difficult.
Introduction to the concept of Database Fragmentation and DDBMS (Distributed Database Management System).
Data fragmentation enables breaking objects like databases and tables into segments for enhanced efficiency, security, and parallelism across the network.Explains horizontal, vertical, and mixed fragmentation with examples related to organizational needs and departmental requirements.
Discusses the benefits like improved performance and availability, as well as limitations such as complexity and security issues.
Bibliography and presentation credits to Ravisha Sethi for the presentation on Database Fragmentation.
Data Fragmentation
“Data fragmentationallows you to break a single
object into two or more segments.”
The object might be:-
o User’s database.
o System database.
o A table
Storage of Fragmentsin DDBMS
Each fragment can be stored at any site over
network .
Information about data fragmentation is stored
in (DDC) .
DDC is accessed by the TP to process user
requests .
9.
Types of DataFragmentation
Horizontal fragmentation
Vertical fragmentation
Mixed fragmentation
11.
Horizontal Fragmentation:
XYZ Company’smanagement requires
information about its customers in all three
states.
States are:-
TN
FL
GA
Requirement:-
Data regarding local customers only.
Vertical Fragmentation
Company’s managementrequires information
about its customers in Two Departments.
Two departments: the service department and
the collections department.
Each department has an interest in only a few of
the CUSTOMER table’s attributes .
Mixed Fragmentation
Company’s structurerequires that the
CUSTOMER data be fragmented horizontally to
accommodate the various company locations.
Within the locations, the data must be
fragmented vertically to accommodate the two
departments.
20.
Advantages of Fragmentation
Reflectsorganizational structure
Improved share ability and local autonomy
Improved availability
Improved reliability
Improved performance
Economics