What is a Mobile Database3

7/31/2019 What is a Mobile Database3

1/27

By

Champa. S. Bopegama

PG/IT/09/097

MOBILE DATABASE


2/27

What is a mobile database?

A mobile database is a database that canbe connected to with a mobile computer

device through a mobile network.


3/27

The client and server have wireless

connections.

Users can exchange mission-critical dataremotely without worrying about time or

distance from their mobile phones or PDAswith mobile databases.

What is a mobile database?


4/27

The Mobile Database Application

Mobile applications can be categorized in two ways.

1. Vertical Applications

2. Horizontal applications.


5/27

Vertical application

In a vertical applications users access data

within a specific cell, and access is denied to

users outside of that cell.

E.g.- users can obtain information on the

location of doctors or emergency centers

within a cell or parking availability data at an

airport cell.


6/27

Horizontal Application

In horizontal applications users cooperate on

accomplishing a task, and they can handle data

distributed throughout the system.


7/27

Types of data in MobileApplications

Data can be classified into three categories

1. Private data

2. Public data

3. Shared data


8/27

Private data

A single user owns this data and manage it. No

other user may access it.


9/27

Public data

This data can be used by anyone who can read

it. Only one source updates it.

E.g. Weather bulletins or stock prices.

Primarily managed by vertical applications.


10/27

Shared data

This data is accessed both in read and write

modes by group of users.

E.g.- Inventory data for products in a

company.

Shared data is used by horizontal applications.


11/27

In a mobile database application a part or a

replica of the database is locally installed on

the mobile device. This is a significant

difference compared to a con-ventional client-

server application where all data is centrally

stored in a database server.

Motivation


12/27

Mobile database systemarchitecture

Users are not attached to a fixedgeographical location

Mobile computing devices: low-power,

low-cost, portable Wireless networks

Mobile computing constraints


13/27

Three parties involving in Mobiledata base

Mobile Data Base

Fixed hosts Mobile units Base stations


14/27

Fixed hosts

Perform the transaction and data

management functions with the help

of database servers.


15/27

Mobile units

portable computers

move around a geographical region

includes the cellular network (or "cells")

these units are used to communicate withbase stations.

these networks do not need to be cellular

telephone networks


16/27

Base stations

Two-way radio installations in fixedlocations

communicates with the mobile units to

and from the fixed hosts. typically low-power devices such as mobile

phones, portable phones, or wirelessrouters.


17/27

A general architecture of a mobileplatform


18/27

A Mobile database system


19/27

Characteristics of MobileDatabase Environments

Residence latency.

users are mobile and randomly enter and exitfrom cells.The average duration of the user stayin cell is referred as residence latency.

Intermittent connectivity.

Limited battery life.

Changing client location.


20/27

Oracle Database Lite 10g providesmobile workers the experience ofcontinuous access to data

unconstrained by network bandwidthand coverage. It extends the gridenvironment to mobile devices,allowing mobile workers to access

enterprise data even in the absenceof a network connection.

Mobile database tools


21/27

Architecturediagram ofOracle Database Lite 10g


22/27

Data Management Issues

From a data management standpoint,

mobile computing may be considered asa variation of distributed computing.


23/27


Mobile databases can be distributed under twopossible scenarios:

1. The entire database is distributed mainly

among the wired components, possibly with fullor partial replication. A base station or fixedhost manages its own database with a DBMS-like functionality, with additional functionalityfor locating mobile units and additional query

and transaction management features to meetthe requirements of mobile environments.


24/27


2. The database is distributed among wiredand wireless components. Datamanagement responsibility is shared

among base stations or fixed hosts andmobile units


25/27


Data management issues as it is applied to mobiledatabases:

Data distribution and replication

Transactions models Query processing

Recovery and fault tolerance

Mobile database design

Location-based service Division of labor

Security


26/27

References

Fundamentals of database systems

Elmasri & Nawathe

http://www.wikiepedia/Mobile databasesystems


27/27

Thank you!

Documents

What is a Mobile Database3