DATA BASE MANAGEMENT SYSTEM(DBMS)

•Pushpendra Singh•Vikarant Sood• Yojana Wagle• Monika Shrivastav •Prasad Tawade, •Shweta Verpul

Information Technology Study Presentation23th Sep 2011

Garware Institute Of Career Education And DevelopmentUniversity of Mumbai

Post Graduate Program in ManagementInformation Technology

What is a Database?• A structured collection of related data • An filing cabinet, an address book, a telephone

directory, a timetable, etc.• Google and your email is a database• School Student Information System

DBMS

A DBMS consists of a group of programs that manipulate the database and provide an interface between the database , the user of the database and other application programs.

• A DBMS is a collection of programs which

• provide management of databases

• control access to data

• contain a query language to retrieve information easily

Features Of DBMS

• Query Ability:-Query Ability Is The Process Of requesting attribute Information Form Various perspectives and Combination Of factors.

• Backup :- Means follow up of original data if in case of original data is virus infected.

• Rule enforcement:- Often one wants to apply rules to attributes so that attributes are clean and reliable.

• Security:- For security reason it is desirable to limit who can see or change specific attributes or groups of attributes.

4

Features

• Computation:- Common computation requested on attributes are counting summing, averaging, sorting, grouping ,cross – referring and so on.....

• Change and access logging:- This describes who accessed which attributes, what was changed, and when it was changed.

• Automated optimization:- For frequently occuring usage patterns or requests.

Plan Executor

OptimizerOperator Evaluator

ParserSQL Engine

Recovery Manager

LockManager

TxManager

Files & Access

Buffer Manager

Disk Space Manager DBMS

CatalogData File Database

Web Forms Front-EndSQL I/f

SQL Commands

DBMS Architecture

The External Model

Each end users’ view of the data environment Modeler subdivides requirements and constraints into

functional (Business unit’s) modules These can be examined within the framework of their external

models

The Conceptual Model

• Global view of the entire database• Representation of data as viewed by the entire organization• Basis for identification and high-level description of main

data objects, avoiding details

The Internal Model

• The database as “seen” by the DBMS• Maps the conceptual model to the DBMS• Depicts a specific representation of an internal model• Logical independence

– Can change the internal model without affecting the conceptual model

The Physical Model

• Lowest level of abstraction– Describes the way data are saved on

storage media such as disks or tapes

• Software and hardware dependent– Requires database designers to have a

detailed knowledge of the hardware and software used to implement database design

• Physical independence – Can change the physical model without

affecting the internal model

Let’s explore some examples

• Outlook contacts• Aspira Association MIS• KidTrax• GIS-GPS systems

Components of DBMS:

• Data dictionary: A data dictionary is a reserved space within a database which is used to store information about the database itself.

• Database Engine: The Database Engine is the core service for storing, processing, and securing data.

• Data definition subsystem: create and maintain the data dictionary and define the structure of the files in a database.

• Data manipulation subsystem: helps the user to add, change, and delete information in a database.

• Application generation subsystem: helps users develop transaction-intensive applications.

• Data administration subsystem: helps users manage the overall database environment.

Purpose of Database SystemIn the early days, database applications were built on top of file

systems

Drawbacks of using file systems to store data:• Data redundancy and inconsistency• Multiple file formats, duplication of information in different

files• Difficulty in accessing data • Need to write a new program to carry out each new task• Data isolation — multiple files and formats• Integrity problems

• Integrity constraints (e.g. account balance > 0) become part of program code

• Hard to add new constraints or change existing ones

ADVANTAGES OF A DBMS• Data Administration

When any users share the data, centralizing the administration of data can offer significant improvements.

• Concurrent Access and Crash Recovery

A DBMS schedules concurrent access to the data in such manner that users can think of the data as being accessed by only one user at a time. DBMS also protects users from the effects of system failures.

• Reduced Application Development Time

DBMS includes several important functions that are common to many applications accessing data in the DBMS. In conjunction with the high-level interface to the data, facilitates quick application development.

Disadvantages of DBMS

• Complexity• Size• Technical experts are required • Cost of DBMS development • Additional hardware costs• Performance monitoring & maintenance • Higher impact of a failure• Centralization: That is use of the same program at a time by

many user sometimes lead to loss of some data.• Limited Statistical Capabilities: Can not perform sophisticated

calculations • Security issues

USES OF DATA BASE MANAGEMENT SYSTEM

UNIVERSITY1) DATA: departments,students,exams,rooms.2) USAGES: creating exams plans,enter exam results,create statistics,build timetable.

BANKS1) DATA: clients,accounts,credits,funds.2) APPLICATIONS: accounting, transfer,risk management

AIRLINES1) DATA: flight,passenger,employess,airplanes.2) APPLICATIONS: reservations,booking,creting flight schedules.

STOCK MARKET & LIBRARIES etc.

USE A DATABASE IF…

1)the information is a large amount that would become unmanageable in spreadsheet form and is related to a particular subject.

2)you want to maintain records for ongoing use. 3)the information is subject to many changes (change of address, pricing changes, etc.).

AC Nielson & Morgan Stanley

AC Nielson is one of the worlds leading market information

providers, not only does AC Nielson provide marketplace analysis and

dynamics, but they do it in over 100 countries.

Another company that has utilized database technology in the new

millennium is Morgan Stanley.

Since 1993, Morgan Stanley, an international financial services firm,

has been using Kerberos 4.

Kerberos helped Morgan Stanley with solving the classic security

problems of clear text passwords and single sign-on.

APPLICATION USED IN REAL WORLD

• Banking System and ATM's machines.

• Stock Trading Systems.

• Flight Reservation Systems.

• Computerized Library Systems.

• Super Market Product Inventory System.

• Credit Card/Credit Limit Check System

Advanced DATABASE MANAGEMENT SYSTEM

Database management system is now broadly

advanced into main two :-

• Network database management system.

• Distributed database management system.

Network database management system

Through communication network a centralizeddatabase is adopted which is known as“Network DBMS”.• In a centralized DBMS, data base is stored at one site.• It takes more time and has less reliability.

Example of Network database management system –Banking System and ATM's machines-

Network database management system

Central Head site(mum)

Communication Network

Site 2- Delhi

Site 1- chennai

Site 3-hydrabad

Site 4-Bnaglor

e

DB1 DB2

Distributed Database management system

Through communication network a database is decentralized ans so it is known as “Distributed DBMS”.

• In a decentralized DBMS, data base is stored at several site.

• It takes less time and has more reliability.Example of Distributed database management

system – Supply chain system

Distributed Database management system

Communication

Network

Site 1

Site 2 DBSite 3DB

Site 4

DB

DB