Database 1 Introduction

February 23 , 2002 A. K. Ramani 1

WORKSHOP ON

DESIGN OF INFORMATION SYSTEMS FOR BUSINESS ORGANIZATIONS

by

A. K. RAMANI

DIRECTOR, IIPS, DAVV, INDORE

[email protected]

WELCOMEWELCOME


$ 10 Billion Industry

Shift of focus in research from Computation towards Information Management

Broadening application areas, like weather, genetic, entertainment, CAE, data warehousing, data mining, and decision making.

Advances in areas, like visualization, robotics, optical storage, high speed communications

MOTIVATIONMOTIVATION


Motivation

Limited understanding of DB principles and techniques for advanced information management.Next generation DBs will need MM support, complex objects, real-time, rule processing…Co-operation in Scientific, engineering, commercial problems will need large scale heterogeneous distributed DBsRequirements: Efficiency, Resilience, Access control, Persistence


DBMSs to organize, create, and maintain collections of information.

Challenge is to apply DB technology in new and important areas in scientific databases, design databases, business, and utility databases and many more.

CHALLENGE OF DB TECH.CHALLENGE OF DB TECH.


An Instant Virtual Enterprise (IVE) is a group of companies, that do not routinely function as a unit, come together to respond to a proposal of CIM. The task involves CAD, production, QA, Product planning, resource management etc.

In such an environment it is necessary for IVE companies to exchange and cooperatively manage the large amount of data.

SCENARIOSCENARIO


A personnel information system provides information tailored to an individual, and delivered via a GPS of laptop, and access internet from any where any time, from waking up to bed time. Weather report, day special events, appointments, diet, best route, news headlines, sporting events, best investments, list of tasks, start of sale, best air ticket, best return route, preview of next day, by querying remote DBs.

SCENARIOSCENARIO


The aim of this workshop is to help you developing an understanding of database development techniques in information management applications, and become an expert database developer.

AIMAIM


OBJECTIVESOBJECTIVES

To familiarize with the concept of database development.To present the various steps in the approach to database development.To see an example of a DBMS oriented approach.


EVOLUTION OF DATABASE TECHNOLOGIESEVOLUTION OF DATABASE TECHNOLOGIES


Sequential Records

Index for random Access

Open, Close, Read, Write, Delete

Redundancy, inconsistency, poor data sharing,low productivity etc.

FILE SYSTEM FILE SYSTEM


A conventional File Processing System



_ In file processing,each dept has own IS– For new system, new programs are needed

Disadvantages– Program data dependence - All program to be changed for

any change in file designs ( Record Formats)

– Duplication – Data inconsistency

– Poor Data Sharing – Incompatible files.

– Lengthy Development Times

Every new application start from scratch low productivityHigh maintenance cost 80% cost



Hierarchical & Network Systems– Complex record structures

– Difficult to change application programs

Program

Class

STDDORM

STAFF

Course

Faculty

Employee

DATABASE MODELS DATABASE MODELS


RELATIONAL MODELRELATIONAL MODEL

Relational DB Systems

– Data in Tables form

– Simple SQL

– Example DB2,ORACLE,INGRESS

– Difficult to handle Complex data & Relation ships


Object Oriented Modeling

Program

Class

STDDORM

STAFF

Course

Faculty

Employee

DATABASE MODELS DATABASE MODELS


Student

Name,DOB,GPA

take Course

------

------

Faculty

Name,Rank Salary

Advice

Research

------

Course

Title,Credit

Pre requisite

Class

Time

Assign Lab

is advised by

TakeTeach

OBJECT MODELOBJECT MODEL


Object oriented model

For complex Relationships

UML (Unified Modeling Language)

Easy to maintain & Change

Improved Productivity


Aim Introduce different concepts of DBMS, in context of Information System development.

Objectives– Define database & related terms

– Understand DBMS components , role & DBMS architecture

– Limitations of Conventional File System

– Introduce DB approach , ER concept , Categories of DB applications & issue

– Advantage of DB approach

– Evolution of DBMS

INTRODUCTION TO DBMSINTRODUCTION TO DBMS


Database is a data bank, where data can be stored manipulated and retrieved in a speedy manner, efficiently and error free.A database is a model of structures of realityThe use of a database reflect processes of realityA database system is a software system which supports the definition and use of a databaseDDL: Data Definition LanguageDML: Data Manipulation Language

WHAT IS A DATABASEWHAT IS A DATABASE

REALITY

• structures

• processes

DATABASE SYSTEM

DATABASE

DML

DDL


Database is a representation of a part of real world in terms of computable objects.

E = {Object,Attributes,Data}, where E is an Entity.

D = {E1,E2,………En}, where D is database

– How to implant changes in database

By using a set of software modules.– DBMS = Database + S/W modules

S/W DB

Applications

Tools

Applications DB S/W Data

Data Base

Database

WHAT IS A DATABASEWHAT IS A DATABASE


Data– is a known (valued) fact.– is a value to an attribute– can be recorded on computer mediaExample : This house has four rooms.Database = Object + data + attributes– Data can comprise of facts,which may include numeric,text,

images, sound & multimedia.– Database is an organized collection of logically related data

where data can be stored easily, manipulated,retrieved.– Data becomes information when processed.– Meta Data are data that describe the properties of data,

include data definitions, data sizes, rules, constraints etc.


Data Collection– Data - Stores facts– Information – Extracted & derived data for a specific purpose

DBMS Software– Efficiently and reliably manages data storage, retrieval, data update

(Insert, Modify, Delete)

Automated Tools– For design,query and application development

Database Users– End Users– Data Analysts & Application Programmer– DB designers– DBA

DATABASE COMPONENTSDATABASE COMPONENTS


Field – It is a set of bytes to represent some values,lowest

level of database ( or logical structure)

Record– Group of logically related fields,records accessed

via S/W

File– A group of identical records,accessible via system

software

Database– A set of related files , accessed via system software.

DEFINITIONDEFINITION


Insert Picture of slide 5


Use a DBMS when this is important

persistent storage of data

centralized control of data

control of redundancy

control of consistency and integrity

multiple user support

sharing of data

data documentation

data independence

control of access and security

backup and recovery

WHEN TO USE DBMSWHEN TO USE DBMS


Do not use a DBMS when

the initial investment in hardware, software, and training is too high

the generality a DBMS provides is not needed

the overhead for security, concurrency control, and recovery is too high

data and applications are simple and stable

real-time requirements cannot be met by it

multiple user access is not needed

WHEN NOT TO USE DBMSWHEN NOT TO USE DBMS

Applications programs / Queries

Software for queries / Programs

Software to access data base

Meta Data DB

TransactionsDatabase System

Software Modules

DBMS ARCHITECTUREDBMS ARCHITECTURE


The purpose of database design is to create a database which

is a model of structures of realitysupports queries and updates modeling processes of realityruns efficiently

DB approach is total integration and sharing of data throughout the organization

DATABASE DESIGNDATABASE DESIGN


Goal : Business Strategies supported upon IT 3 Steps1. Identify strategic planning factors

• Goals : Growth Rate……..• Success Factors : Quality,On-time…..• Problem Areas : Competition….

Set priorities of needs of IS & DB 2. Identify Corporate Planning objects

1. Organizational Units – Various depts2. Locations – business places3. Business Functions – business processes like product development

4. Entity Types : Categories of data about people,places & things managed by company 5. Information System : Application S/W & supporting procedures.

IS PLANNINGIS PLANNING


Develop list of Entities that support the business activities– An entity is an object/concept that is important to business, e,g,

CUSTOMER,PRODUCT,EMPLOYEE,ORDER etc

– Identification & definition of Entities.

Develop Enterprise Data Model to show association among entities. Also called as E-R models.

Customer

Order

Product

Order Line

Places

is Placed by

has

is for

Contains is containedin



Entities– Customer : People / Companies / potential customer– Order : Purchase of 1 or more items– Product : Items produced for selling– Order Line : Details of each product (quantity price ) sold on

a particular customer

Apply Business Rules For Relation ShipsEach Customer places >= 1 OrderEach order is placed by one CustomerEach order contains >=1 L (ask slide 10)Each L is contained in One Customer Order (O)Each product has >=1 LEach order line is for one product



ER Model– Tells how organization functions and constraints

– Emphasizes on data & process by considering data, relationships & business rules.

Relational Databases– Data is viewed in form of tables

– Tables are based upon entities of ER model and contains attributes of an entity and its instances (value)

– Few attributes are common among tables e.g. ID nos., Employee number

Historical and summarized information (ask it) data base is called Data Ware House ( D-Mgt ask it) to assist DSS.

Data base application program can perform actions like Create, Read, Update, Delete etc.



Area of Application

Perspective

Work-Processes

Guidelines for Work-Processes in the development of the application

DATABASE DEVELOPMENTDATABASE DEVELOPMENT


Development of medium to large size data intensive applicationsData intensive: – lots of data– little processing– insertions, deletions, updates,– queries

What is medium to large? Small is:– well-defined project– short development time– no long-term maintenance– few people; little turnover– no critical resources– small risk of failure– small cost of failure

Why only medium to large?– the methodology is an insurance policy– cost of using methodology is high

AREA OF APPLICATIONAREA OF APPLICATION


Business process is well-designedDocuments are knownTasks are knownSystem boundary is knownOne database schema unifying all views can be designed– difficult: interests, goals, power, politics– problems with the methodology?– problems with the organization?– or-gan-i-za-tion: “an entity created to pursue a shared

set of goals”

PERSPECTIVEPERSPECTIVE


Business process (re-)designAnalysisSpecificationDesignImplementationTestingOperationMaintenance

Managem

ent

WORK PROCESSESWORK PROCESSES


Purpose: what we do?Input: what we start with?Output: what we end with?Tool: what we use?Technique: how we use it?Organization: who does what?

GUIDELINES FOR WORK-PROCESSESEGUIDELINES FOR WORK-PROCESSESE


waterfall model; this is not prototypingiteration necessarywork vs. time vs. peopleestimating resources is very difficult

work-process

time

analysis specification design implementation test

TIME AND MANAGEMENTTIME AND MANAGEMENT


Type User Architecture Size1. PC 1 Desktop Megabytes

2. WorkGroup 5-25 Client/Server (2 Tier) M-G bytes

3. Department 25-100 Client/Server (3 Tier) G bytes

4. Enterprise > 100 Client/server (Distributed) G-Terabytes

CATEGORIES OF DB APPLICATIONCATEGORIES OF DB APPLICATION


Optimized Database Design

Integrity of Database

Performance

Security

Redundancy & Consistency

Distributed Database Designs

DATABASE ISSUEDATABASE ISSUE


Program-Data Independence– Metadata & programmes are independent

Minimal Redundancy– Single logical structure

Data Consistency– Each value stored on one place

Data Sharing– To form report from more than 1 table

Increased Productivity in Development– Saves cost/time

Enforcement of Standards– Feasible

Improved Data Quality– Enforce constraints– Data Management approach

Simplicity in Data Access– Select * from product where Product_name =“Computer” ;

It is a SQL commandEasy Maintenance

– Y2k Problem

ADVANTAGES OF DB APPROACHADVANTAGES OF DB APPROACH


Expensive New H/W , Operating Cost

Complex Development/Implement

Recovery more difficult

Vulnerability to failure

Organizational Conflicts strong top management support must.

DISADVANTAGESDISADVANTAGES


Future Trends– Object – Relational Databases

– Distributed Databases• Distributed to multiple locations,transparent

– Content Addressable

– Interface other technologies like AI, TV, Natural Language Interface

Summary– Database & related terms

– DB approach,Advantages

– Categories,Evolution

– Future Trends

FUTURE TREND AND SUMMARYFUTURE TREND AND SUMMARY

Database 1 Introduction

Education

Transcript of Database 1 Introduction