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David M. Kroenke’s Database Processing: Fundamentals, Design, and Implementation Chapter One: Introduction 1-1 Today’s Objectives • To compare & contrast information with data • Explain the characteristics that distinguish the database approach from the traditional approach of programming with data files. • Identify major DBMS functions and describe their role in a database system. 1-2 Data vs. Information • What is data? • What is information? SID Name 175 Robert Course Number Name 102 Brian CSCI220 Java 104 Jeff CSCI221 Java 2 109 Michael CSCI230 Data Structures 240 Peter CSCI332 Database CSCI362 Software Engineering SID CourseID Grade Semester 102 CSCI220 3.0 20037 109 CSCI332 3.5 20057 240 CSCI362 2.0 20041 240 CSCI362 3.75 20051 1-3 Information Systems • A system, whether automated or manual, that comprises people, machines, and/or methods organized to collect, process, transmit, and disseminate data that represent user information. ~Wikipedia • Examples: supermarket, credit card purchases, CougarTrail 1-4 Traditional File Based Systems • 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. ~Connolly & Begg • E.g. The department’s student file cabinet. • Effective: small files or 1 large files • Ineffective: cross-references • Limitations: Data duplication, data dependence (data stored with its physical structure), incompatible file formats 1-5 The Database • A database is a self-describing collection of integrated tables • The tables are called integrated because they store data about the relationships between the rows of data • A database is called self-describing because it stores a description of itself • The self-describing data are called metadata, which is data about data DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-6 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 DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-7 Enterprise-Class Database Systems DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-8 Applications, the DBMS and SQL • Applications are the computer programs that users work with • The Database Management System (DBMS) creates, processes and administers databases • Structured Query Language (SQL) is an internationally recognized standard database language that is used by all commercial DBMSs DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall 1-9 DBMS Functions 1. 2. 3. 4. 5. 6. 7. Set up storage Load data Accept requests from users Format retrieved data Deny data to unauthorized users Accept / perform updates Allow concurrent use of data without interferences 8. Perform backup & recovery 1-10 Advantages of DBMS • • • • • • • Control of data redundancy Data consistency Data integrity Security Improved accessibility to information Data independence Increased concurrency 1-11 Information Systems DBMS is at the heart of all modern information systems 1-12 David M. Kroenke’s Database Processing Fundamentals, Design, and Implementation (10th Edition) End of Presentation 1-13