Introduction to Databases

Three File Processing Systems DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-2

A Database System

Advantages of DBMS Data Independence/Reduced Maintenance Improved Data Sharing Increased Application Development Productivity Enforcement of Standards Improved Data Quality (Constraints) Better Data Accessibility/ Responsiveness Security, Backup/Recovery, Concurrency Reduce Redundancy, Reduce inconsistency Increase Integrity Use a high level query language Views: each user views own sub-set of the database

Evolution of Databases

Roles in a DB Environment 1-6 Data Administrator (DA) Database Administrator (DBA) Database Designers (Logical and Physical) Application Programmers End Users (naive and sophisticated)

1-7 The Characteristics of Databases The purpose of a database is to help people track things of interest to them Data is stored in tables, which have rows and columns like a spreadsheet. A database may have multiple tables, where each table stores data about a different thing Each row in a table stores data about an occurrence or instance of the thing of interest A database stores data and relationships A DBMS is the software that administers the DB

Data in Tables

The Key Characteristic of Databases: Related Tables

Databases Create Information Data = Recorded facts and figures Information = Knowledge derived from data Databases record data, but they do so in such a way that we can produce information from the data –The data on STUDENTs, CLASSes and GRADEs could produce information about each student’s GPA

Database Examples

Prominent DBMS Products Microsoft Access Microsoft SQL Server –New: Microsoft SQL Server ExpressMicrosoft SQL Server Express IBM DB2 Oracle Corporation ORACLEOracle Corporation ORACLE Open Source: MySQL, POSTGRESMySQL Art Dept (Apple, Windows): Filemaker Pro Companies: Oracle, IBM, Microsoft,

Typical Metadata Tables