1. © 2009 Pearson Education, Inc. Publishing as Prentice Hall 1 Chapter 1: The Database Environment Modern Database Management 9 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Heikki Topi

2. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 2 Objectives Definition of terms Definition of terms Explain growth and importance of databases Explain growth and importance of databases Name limitations of conventional file processing Name limitations of conventional file processing Identify five categories of databases Identify five categories of databases Explain advantages of databases Explain advantages of databases Identify costs and risks of databases Identify costs and risks of databases List components of database environment List components of database environment Describe evolution of database systems Describe evolution of database systems

3. 3 Definitions Database: organized collection of logically related data Database: organized collection of logically related data Data: stored representations of meaningful objects and events Data: stored representations of meaningful objects and events Structured: numbers, text, dates Structured: numbers, text, dates Unstructured: images, video, documents Unstructured: images, video, documents Information: data processed to increase knowledge in the person using the data Information: data processed to increase knowledge in the person using the data Metadata: data that describes the properties and context of user data Metadata: data that describes the properties and context of user data

4. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 4 Figure 1-1a Data in context Context helps users understand data

5. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 5 Graphical displays turn data into useful information that managers can use for decision making and interpretation Figure 1-1b Summarized data

6. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 6 Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context

7. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall File-Based Systems (FBS) 7 FBS is a collection of application programs that perform tasks where each program defines and manages its own data. Data Entry File handling File Def User 1 Application Program 1 File1 Data Entry File handling File Def User 2 Application Program 2File 2

8. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 8 Disadvantages of File-Based Systems (FBS) Program-Data Dependence Program-Data Dependence All programs maintain metadata for each file they use All programs maintain metadata for each file they use Duplication of Data Duplication of Data Different systems/programs have separate copies of the same data Different systems/programs have separate copies of the same data Limited Data Sharing Limited Data Sharing No centralized control of data No centralized control of data Lengthy Development Times Lengthy Development Times Programmers must design their own file formats Programmers must design their own file formats Excessive Program Maintenance Excessive Program Maintenance 80% of information systems budget 80% of information systems budget

9. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 9 Problems with Data Dependency Each application programmer must maintain his/her own data Each application programmer must maintain his/her own data Each application program needs to include code for the metadata of each file Each application program needs to include code for the metadata of each file Each application program must have its own processing routines for reading, inserting, updating, and deleting data Each application program must have its own processing routines for reading, inserting, updating, and deleting data Lack of coordination and central control Lack of coordination and central control Non-standard file formats Non-standard file formats

10. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 10 Duplicate Data

11. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 11 Problems with Data Redundancy Waste of space to have duplicate data Waste of space to have duplicate data Causes more maintenance headaches Causes more maintenance headaches The biggest problem: The biggest problem: Data changes in one file could cause inconsistencies Data changes in one file could cause inconsistencies Compromises in data integrity Compromises in data integrity

12. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 12 SOLUTION: The DATABASE Approach Central repository of shared data Central repository of shared data Data is managed by a controlling agent Data is managed by a controlling agent Stored in a standardized, convenient form Stored in a standardized, convenient form Requires a Database Management System (DBMS)

13. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 13 Database Management System DBMS manages data resources like an operating system manages hardware resources A software system that is used to create, maintain, and provide controlled access to user databases Order Filing System Invoicing System Payroll System DBMS Central database Contains employee, order, inventory, pricing, and customer data

14. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 14 Advantages of the Database Approach Program-data independence Program-data independence Planned data redundancy Planned data redundancy Improved data consistency Improved data consistency Improved data sharing Improved data sharing Increased application development productivity Increased application development productivity Enforcement of standards Enforcement of standards Improved data quality Improved data quality Improved data accessibility and responsiveness Improved data accessibility and responsiveness Reduced program maintenance Reduced program maintenance Improved decision support Improved decision support

15. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 15 Costs and Risks of the Database Approach New, specialized personnel New, specialized personnel Installation and management cost and complexity Installation and management cost and complexity Conversion costs Conversion costs Need for explicit backup and recovery Need for explicit backup and recovery Organizational conflict Organizational conflict

16. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 16 Elements of the Database Approach Data models Data models Graphical system capturing nature and relationship of data Graphical system capturing nature and relationship of data Enterprise Data Model–high-level entities and relationships for the organization Enterprise Data Model–high-level entities and relationships for the organization Project Data Model–more detailed view, matching data structure in database or data warehouse Project Data Model–more detailed view, matching data structure in database or data warehouse Relational Databases Relational Databases Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships Use of Internet Technology Use of Internet Technology Networks and telecommunications, distributed databases, client- server, and 3-tier architectures Networks and telecommunications, distributed databases, client- server, and 3-tier architectures Database Applications Database Applications Application programs used to perform database activities (create, read, update, and delete) for database users Application programs used to perform database activities (create, read, update, and delete) for database users

17. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 17 Segment of an enterprise data model Segment of a project-level data model Figure 1-2 Comparison of enterprise and project level data models

18. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 18 One customer may place many orders, but each order is placed by a single customer  One-to-many relationship

19. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 19 One order has many order lines; each order line is associated with a single order  One-to-many relationship

20. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 20 One product can be in many order lines, each order line refers to a single product  One-to-many relationship

21. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 21 Therefore, one order involves many products and one product is involved in many orders  Many-to-many relationship

22. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 22

23. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 23 Figure 1-5 Components of the Database Environment

24. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 24 Components of the Database Environment CASE Tools – computer-aided software engineering CASE Tools – computer-aided software engineering Repository – centralized storehouse of metadata Repository – centralized storehouse of metadata Database Management System (DBMS) – software for managing the database Database Management System (DBMS) – software for managing the database Database – storehouse of the data Database – storehouse of the data Application Programs – software using the data Application Programs – software using the data User Interface – text and graphical displays to users User Interface – text and graphical displays to users Data/Database Administrators – personnel responsible for maintaining the database Data/Database Administrators – personnel responsible for maintaining the database System Developers – personnel responsible for designing databases and software System Developers – personnel responsible for designing databases and software End Users – people who use the applications and databases End Users – people who use the applications and databases

25. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 25 The Range of Database Applications Personal databases Personal databases Workgroup databases Workgroup databases Departmental/divisional databases Departmental/divisional databases Enterprise database Enterprise database Enterprise resource planning (ERP) systems Enterprise resource planning (ERP) systems Data warehousing implementations Data warehousing implementations

26. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 26 Table 1-6 Summary of Database Applications

27. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 27

28. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 28 Figure 1-7 Workgroup database with wireless local area network

29. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 29 Enterprise Database Applications Enterprise Resource Planning (ERP) Enterprise Resource Planning (ERP) Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources) Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources) Data Warehouse Data Warehouse Integrated decision support system derived from various operational databases Integrated decision support system derived from various operational databases

30. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 30 Figure 1-8 An enterprise data warehouse

31. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 31 Web-Enabled Databases Web applications requiring databases Web applications requiring databases Customer relationship management (CRM) Customer relationship management (CRM) Business-to-consumer (B2C) Business-to-consumer (B2C) Electronic data interchange (EDI) Electronic data interchange (EDI) Private intranets Private intranets XML-defined Web services XML-defined Web services

32. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 32 Web-Enabled Databases (cont.) Issues to consider Issues to consider Which technologies to use? Which technologies to use? Security/privacy protection Security/privacy protection Managing huge volumes of data from Internet transactions Managing huge volumes of data from Internet transactions Maintaining data quality Maintaining data quality

33. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 33 Figure 1-9 Evolution of database technologies

34. Chapter 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 34 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall