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© 2005 by Prentice Hall 1 Chapter 1: The Database Environment Modern Database Management 7 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden.

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Presentation on theme: "© 2005 by Prentice Hall 1 Chapter 1: The Database Environment Modern Database Management 7 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden."— Presentation transcript:

1 © 2005 by Prentice Hall 1 Chapter 1: The Database Environment Modern Database Management 7 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden

2 Chapter 1 © 2005 by 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 categories of databases Identify 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 Chapter 1 © 2005 by 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 © 2005 by Prentice Hall 4 Figure 1-1a Data in Context Context helps users understand data

5 Chapter 1 © 2005 by Prentice Hall 5 Graphical displays turn data into useful information that managers can use for decision making and interpretation

6 Chapter 1 © 2005 by 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 © 2005 by 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 of information systems budget 80% of of information systems budget

8 Chapter 1 © 2005 by Prentice Hall 8 Problems with Data Dependency Each application programmer must maintain their own data Each application programmer must maintain their 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 © 2005 by Prentice Hall 9 Figure 1-2 Three file processing systems at Pine Valley Furniture Duplicate Data

10 Chapter 1 © 2005 by 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: When data changes in one file, could cause inconsistencies When data changes in one file, could cause inconsistencies Compromises data integrity Compromises data integrity

11 Chapter 1 © 2005 by 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 © 2005 by 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

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14 Chapter 1 © 2005 by Prentice Hall 14

15 Chapter 1 © 2005 by Prentice Hall 15 Elements of the Database Approach Enterprise Data Model Enterprise Data Model Graphical model showing high-level entities and relationships for the organization Graphical model showing high-level entities and relationships for the organization 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

16 Chapter 1 © 2005 by Prentice Hall 16

17 Chapter 1 © 2005 by 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 © 2005 by 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 © 2005 by 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 © 2005 by Prentice Hall 20 Therefore, one order involves many products and one product is involved in many orders Many-to-many relationship

21 Chapter 1 © 2005 by Prentice Hall 21 Relationships established in special columns that provide links between tables

22 Chapter 1 © 2005 by Prentice Hall 22 Client/server system architecture

23 Chapter 1 © 2005 by Prentice Hall 23 Application program functions: inserting new data, updating existing data, deleting existing data, reading data for display

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25 Chapter 1 © 2005 by Prentice Hall 25

26 Chapter 1 © 2005 by Prentice Hall 26 Figure 1-9 Workgroup database with local area network

27 Chapter 1 © 2005 by Prentice Hall 27 Figure 1-10 An enterprise data warehouse

28 Chapter 1 © 2005 by Prentice Hall 28 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 Administrators – personnel responsible for maintaining the database Data 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

29 Chapter 1 © 2005 by Prentice Hall 29 Figure 1-11 Components of the database environment

30 Chapter 1 © 2005 by Prentice Hall 30 Evolution of DB Systems Flat files - 1960s - 1980s Flat files - 1960s - 1980s Hierarchical – 1970s - 1990s Hierarchical – 1970s - 1990s Network – 1970s - 1990s Network – 1970s - 1990s Relational – 1980s - present Relational – 1980s - present Object-oriented – 1990s - present Object-oriented – 1990s - present Object-relational – 1990s - present Object-relational – 1990s - present Data warehousing – 1980s - present Data warehousing – 1980s - present Web-enabled – 1990s - present Web-enabled – 1990s - present


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