Introduction & History of Database Systems Unit # 1 Introduction & History of Database Systems

Introduction Introduction Course Outline Project Labs Grading

Queries What is Data? What is Database? What is DBMS?

Basics Data Raw facts/details of a subject or universe of discourse. Database A shared collection of logically related data, designed to meet the information needs of an organization. Database Management System (DBMS) Software that enables users to define, create and maintain the database and provides controlled access to the database

What is the importance of data? Paradigm shift: Data driven business environment Knowledge and innovation (e.g., knowledge management, business intelligence) Current Status to identify replenishment needs (e.g. Stock in hand) Performance of vendors (e.g., supply chain management Competitor and marketplace information Customer information (e.g., database marketing, CRM)

History of Database Systems First generation File based systems Second generation Relational databases Third generation Object relational databases Object Oriented databases ……….and others

Traditional File-Based System “A collection of application programs that perform services for the end users such as the production of reports. Each program defines and manages its own data.”

Traditional File-Based System Invoices Customer Orders Invoice Program Customer Account Customer Accounts File Account Report Program Customer Mailing List Customer Mailings Mailing List Program

Data Redundancy Customer Order File Customer Account File Invoice number Customer account number Customer name, address, city, state, zip code Order date Product code, product description, price, unit Customer Account File Account Number Customer name, mailing address, city, state, zip code Customer Mailing List File

File-Based Systems - Limitations Separation and isolation of data (one file, one program) Duplication of data Loss of data integrity - uncertainty of the correct version of data and no consistency Data dependence - application program defines the data Incompatibility of file formats Fixed queries/proliferation of application programs. Little flexibility in meeting changing information needs

Database Database can more technically be defined as: ‘Shared collection of logically related data, and a description of that data, designed to meet information needs of an organization.’ OR ‘Self-describing collection of integrated record.’

Database Management System (DBMS) DBMS can be defined as: “ Software system that enables users to define, create and maintain the database and provides controlled access to the database.” Database Management System (DBMS) contains not only the data but meta data as well i.e. data about the data

Illustrating Metadata