1. © 2011 Pearson Education, Inc. Publishing as Prentice Hall 1 Chapter 1: The Database Environment and Development Process Modern Database Management 10 th Edition Jeffrey A. Hoffer, V. Ramesh, Heikki Topi

2. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 2 Objectives Define terms Define terms Name limitations of conventional file processing Name limitations of conventional file processing 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 Identify categories of database applications Identify categories of database applications Describe database system development life cycle Describe database system development life cycle Explain prototyping and agile development approaches Explain prototyping and agile development approaches Explain roles of individuals Explain roles of individuals Explain the three-schema architecture for databases Explain the three-schema architecture for databases

3. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 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 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 4 Figure 1-1a Data in context Context helps users understand data

5. Chapter 1 © 2011 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 © 2011 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 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 7 Disadvantages of File Processing 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

8. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 8 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

9. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 9 Duplicate Data

10. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 10 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

11. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 11 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)

12. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 12 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

13. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 13 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

14. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 14 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

15. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 15 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 Entities Entities Noun form describing a person, place, object, event, or concept Noun form describing a person, place, object, event, or concept Composed of attributes Composed of attributes Relationships Relationships Between entities Between entities Usually one-to-many (1:M) or many-to-many (M:N) Usually one-to-many (1:M) or many-to-many (M:N) 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

16. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 16 Segment of an enterprise data model Segment of a project-level data model Figure 1-3 Comparison of enterprise and project level data models

17. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 17 One customer may place many orders, but each order is placed by a single customer  One-to-many relationship

18. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 18 One order has many order lines; each order line is associated with a single order  One-to-many relationship

19. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 19 One product can be in many order lines, each order line refers to a single product  One-to-many relationship

20. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 20 Therefore, one order involves many products and one product is involved in many orders  Many-to-many relationship

21. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 21

22. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 22 Figure 1-5 Components of the Database Environment

23. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 23 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

24. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 24 The Range of Database Applications Personal databases Personal databases Two-tier Client/Server databases Two-tier Client/Server databases Multitier Client/Server databases Multitier Client/Server databases Enterprise applications Enterprise applications Enterprise resource planning (ERP) systems Enterprise resource planning (ERP) systems Data warehousing implementations Data warehousing implementations

25. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 25

26. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 26 Figure 1-6 Two-tier database with local area network

27. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 27 Figure 1-7 Three-tiered client/server database architecture

28. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 28 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

29. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 29 Figure 1-8a Evolution of database technologies

30. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 30 Enterprise Data Model First step in database development First step in database development Specifies scope and general content Specifies scope and general content Overall picture of organizational data at high level of abstraction Overall picture of organizational data at high level of abstraction Entity-relationship diagram Entity-relationship diagram Descriptions of entity types Descriptions of entity types Relationships between entities Relationships between entities Business rules Business rules

31. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 31 FIGURE 1-9 Example business function-to-data entity matrix

32. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 32 Two Approaches to Database and IS Development SDLC SDLC System Development Life Cycle System Development Life Cycle Detailed, well-planned development process Detailed, well-planned development process Time-consuming, but comprehensive Time-consuming, but comprehensive Long development cycle Long development cycle Prototyping Prototyping Rapid application development (RAD) Rapid application development (RAD) Cursory attempt at conceptual data modeling Cursory attempt at conceptual data modeling Define database during development of initial prototype Define database during development of initial prototype Repeat implementation and maintenance activities with new prototype versions Repeat implementation and maintenance activities with new prototype versions

33. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 33 Systems Development Life Cycle (see also Figure 1-10) Planning Analysis Physical Design Implementation Maintenance Logical Design

34. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 34 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Planning – Purpose – preliminary understanding – Deliverable – request for study – Database activity – enterprise modeling and early conceptual data modeling

35. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 35 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Analysis Purpose–thorough requirements analysis and structuring Deliverable–functional system specifications Database activity–thorough and integrated conceptual data modeling

36. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 36 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Purpose–information requirements elicitation and structure Deliverable–detailed design specifications Database activity– logical database design (transactions, forms, displays, views, data integrity and security)

37. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 37 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Physical Design Purpose–develop technology and organizational specifications Deliverable–program/data structures, technology purchases, organization redesigns Database activity– physical database design (define database to DBMS, physical data organization, database processing programs)

38. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 38 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Implementation Purpose–programming, testing, training, installation, documenting Deliverable–operational programs, documentation, training materials Database activity– database implementation, including coded programs, documentation, installation and conversion

39. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 39 Systems Development Life Cycle (see also Figure 1-10) (cont.) Planning Analysis Physical Design Implementation Maintenance Logical Design Maintenance Purpose–monitor, repair, enhance Deliverable–periodic audits Database activity– database maintenance, performance analysis and tuning, error corrections

40. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 40 Prototyping Database Methodology (Figure 1-11)

41. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 41 Prototyping Database Methodology (Figure 1-11) (cont.)

42. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 42 Prototyping Database Methodology (Figure 1-11) (cont.)

43. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 43 Prototyping Database Methodology (Figure 1-11) (cont.)

44. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 44 Prototyping Database Methodology (Figure 1-11) (cont.)

45. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 45 Database Schema External Schema External Schema User Views User Views Subsets of Conceptual Schema Subsets of Conceptual Schema Can be determined from business-function/data entity matrices Can be determined from business-function/data entity matrices DBA determines schema for different users DBA determines schema for different users Conceptual Schema Conceptual Schema E-R models–covered in Chapters 2 and 3 E-R models–covered in Chapters 2 and 3 Internal Schema Internal Schema Logical structures–covered in Chapter 4 Logical structures–covered in Chapter 4 Physical structures–covered in Chapter 5 Physical structures–covered in Chapter 5

46. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 46 Different people have different views of the database…these are the external schema The internal schema is the underlying design and implementation Figure 1-12 Three-schema architecture

47. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 47 Managing Projects Project–a planned undertaking of related activities to reach an objective that has a beginning and an end Project–a planned undertaking of related activities to reach an objective that has a beginning and an end Involves use of review points for: Involves use of review points for: Validation of satisfactory progress Validation of satisfactory progress Step back from detail to overall view Step back from detail to overall view Renew commitment of stakeholders Renew commitment of stakeholders Incremental commitment–review of systems development project after each development phase with rejustification after each phase Incremental commitment–review of systems development project after each development phase with rejustification after each phase

48. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 48 Managing Projects: People Involved Business analysts Business analysts Systems analysts Systems analysts Database analysts and data modelers Database analysts and data modelers Users Users Programmers Programmers Database architects Database architects Data administrators Data administrators Project managers Project managers Other technical experts Other technical experts

49. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 49 FIGURE 1-13 Computer System for Pine Valley Furniture Company

50. Chapter 1 © 2011 Pearson Education, Inc. Publishing as Prentice Hall 50 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 © 2011 Pearson Education, Inc. Publishing as Prentice Hall