7.1 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources 7 7 MANAGING DATA DATARESOURCES Chapter

7.2 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Why do businesses have trouble finding the information they need in their information systems?Why do businesses have trouble finding the information they need in their information systems? How does a database management system help businesses improve the organization of their information?How does a database management system help businesses improve the organization of their information? OBJECTIVES

7.3 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources How do the principal types of database models affect the way businesses can access and use information?How do the principal types of database models affect the way businesses can access and use information? What are the managerial and organizational requirements of a data- base environment?What are the managerial and organizational requirements of a data- base environment? What new tools and technologies can make databases more accessible and useful?What new tools and technologies can make databases more accessible and useful? OBJECTIVES

7.4 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Organizational obstacles to a database environmentOrganizational obstacles to a database environment Integrating data and ensuring qualityIntegrating data and ensuring quality MANAGEMENT CHALLENGES

7.5 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources File Organization Terms and Concepts Bit: Smallest unit of data; binary digit (0,1)Bit: Smallest unit of data; binary digit (0,1) Byte: Group of bits that represents a single characterByte: Group of bits that represents a single character Field: Group of words or a complete numberField: Group of words or a complete number ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.6 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Record: Group of related fieldsRecord: Group of related fields File: Group of records of same typeFile: Group of records of same type Database: Group of related filesDatabase: Group of related files File Organization Terms and Concepts ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.7 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Data Hierarchy in a Computer System Figure 7-1 ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.8 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Entity: Person, place, thing, event about which information is maintainedEntity: Person, place, thing, event about which information is maintained Attribute: Description of a particular entityAttribute: Description of a particular entity Key field: Identifier field used to retrieve, update, sort a recordKey field: Identifier field used to retrieve, update, sort a record File Organization Terms and Concepts ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.9 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Figure 7-2 Entitities and Attributes ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.10 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT Data redundancyData redundancy Program-Data dependenceProgram-Data dependence Lack of flexibilityLack of flexibility Poor securityPoor security Lack of data-sharing and availabilityLack of data-sharing and availability Problems with the Traditional File Environment

7.11 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Traditional File Processing Figure 7-3 ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

7.12 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources THE DATABASE APPROACH TO DATA MANAGEMENT Creates and maintains databasesCreates and maintains databases Eliminates requirement for data definition statementsEliminates requirement for data definition statements Acts as interface between application programs and physical data filesActs as interface between application programs and physical data files Separates logical and physical views of dataSeparates logical and physical views of data Database Management System (DBMS)

7.13 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources The Contemporary Database Environment Figure 7-4 THE DATABASE APPROACH TO DATA MANAGEMENT

7.14 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Components of DBMS Data definition language: Specifies content and structure of database and defines each data elementData definition language: Specifies content and structure of database and defines each data element Data manipulation language:Data manipulation language: Manipulates data in a database Data dictionary: Stores definitions of data elements, and data characteristicsData dictionary: Stores definitions of data elements, and data characteristics THE DATABASE APPROACH TO DATA MANAGEMENT

7.15 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Sample Data Dictionary Report THE DATABASE APPROACH TO DATA MANAGEMENT Figure 7-5

7.16 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Types of Databases Relational DBMSRelational DBMS Hierarchical and Network DBMSHierarchical and Network DBMS Object-Oriented DatabasesObject-Oriented Databases THE DATABASE APPROACH TO DATA MANAGEMENT

7.17 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Relational DBMS Represents data as two-dimensional tables called relationsRepresents data as two-dimensional tables called relations Relates data across tables based on common data elementRelates data across tables based on common data element Examples: DB2, Oracle, MS SQL ServerExamples: DB2, Oracle, MS SQL Server THE DATABASE APPROACH TO DATA MANAGEMENT

7.18 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Figure 7-6 Relational Data Model THE DATABASE APPROACH TO DATA MANAGEMENT

7.19 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Three Basic Operations in a Relational Database Select: Creates subset of rows that meet specific criteriaSelect: Creates subset of rows that meet specific criteria Join: Combines relational tables to provide users with informationJoin: Combines relational tables to provide users with information Project: Enables users to create new tables containing only relevant informationProject: Enables users to create new tables containing only relevant information THE DATABASE APPROACH TO DATA MANAGEMENT

7.20 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Figure 7-7 THE DATABASE APPROACH TO DATA MANAGEMENT Three Basic Operations in a Relational Database

7.21 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Hierarchical and Network DBMS Hierarchical DBMS Organizes data in a tree-like structureOrganizes data in a tree-like structure Supports one-to-many parent-child relationshipsSupports one-to-many parent-child relationships Prevalent in large legacy systemsPrevalent in large legacy systems THE DATABASE APPROACH TO DATA MANAGEMENT

7.22 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Hierarchical DBMS Figure 7-8 THE DATABASE APPROACH TO DATA MANAGEMENT

7.23 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Hierarchical and Network DBMS Network DBMS Depicts data logically as many-to-many relationshipsDepicts data logically as many-to-many relationships THE DATABASE APPROACH TO DATA MANAGEMENT

7.24 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Figure 7-9 Network DBMS THE DATABASE APPROACH TO DATA MANAGEMENT

7.25 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Disadvantages OutdatedOutdated Less flexible compared to RDBMSLess flexible compared to RDBMS Lack support for ad-hoc and English language-like queriesLack support for ad-hoc and English language-like queries Hierarchical and Network DBMS THE DATABASE APPROACH TO DATA MANAGEMENT

7.26 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Object-oriented DBMS: Stores data and procedures as objects that can be retrieved and shared automaticallyObject-oriented DBMS: Stores data and procedures as objects that can be retrieved and shared automatically Object-relational DBMS: Provides capabilities of both object-oriented and relational DBMSObject-relational DBMS: Provides capabilities of both object-oriented and relational DBMS Object-Oriented Databases THE DATABASE APPROACH TO DATA MANAGEMENT

7.27 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Basic SQL Commands SELECT: Specifies columnsSELECT: Specifies columns FROM: Identifies tables or viewsFROM: Identifies tables or views WHERE: Specifies conditionsWHERE: Specifies conditions Querying Databases: Elements of SQL THE DATABASE APPROACH TO DATA MANAGEMENT

7.28 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Results of SELECT Statement Figure 7-10 THE DATABASE APPROACH TO DATA MANAGEMENT

7.29 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources THE DATABASE APPROACH TO DATA MANAGEMENT Results of Conditional Selection Figure 7-11 C

7.30 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources THE DATABASE APPROACH TO DATA MANAGEMENT Figure 7-12 Projection from Joining PART and SUPPLIER Tables

7.31 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Conceptual design: Abstract model of database from a business perspectiveConceptual design: Abstract model of database from a business perspective Physical design: Detailed description of business information needsPhysical design: Detailed description of business information needs Designing Databases CREATING A DATABASE ENVIRONMENT

7.32 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Entity-relationship diagram: Methodology for documenting databases illustrating relationships between database entitiesEntity-relationship diagram: Methodology for documenting databases illustrating relationships between database entities Normalization: Process of creating small stable data structures from complex groups of dataNormalization: Process of creating small stable data structures from complex groups of data CREATING A DATABASE ENVIRONMENT Designing Databases

7.33 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources CREATING A DATABASE ENVIRONMENT Figure 7-13

7.34 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources CREATING A DATABASE ENVIRONMENT Figure 7-14

7.35 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources CREATING A DATABASE ENVIRONMENT An Normalized Relation of ORDER Figure 7-15

7.36 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Centralized database Used by single central processor or multiple processors in client/server networkUsed by single central processor or multiple processors in client/server network Distributing Databases CREATING A DATABASE ENVIRONMENT

7.37 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Distributed database Stored in more than one physical locationStored in more than one physical location Partitioned databasePartitioned database Duplicated databaseDuplicated database Distributing Databases CREATING A DATABASE ENVIRONMENT

7.38 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Distributed Databases Figure 7-16 CREATING A DATABASE ENVIRONMENT

7.39 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Management Requirements for Database Systems Key elements in a database environment: Data AdministrationData Administration Data Planning and Modeling MethodologyData Planning and Modeling Methodology Database Technology and ManagementDatabase Technology and Management UsersUsers CREATING A DATABASE ENVIRONMENT

7.40 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Figure 7-17 CREATING A DATABASE ENVIRONMENT Management Requirements for Database Systems

7.41 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Multidimensional Data Analysis On-line analytical processing (OLAP) Multidimensional data analysisMultidimensional data analysis Supports manipulation and analysis of large volumes of data from multiple dimensions/perspectivesSupports manipulation and analysis of large volumes of data from multiple dimensions/perspectives DATABASE TRENDS

7.42 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Multidimensional Data Model Figure 7-18 DATABASE TRENDS

7.43 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Data warehouse Supports reporting and query toolsSupports reporting and query tools Stores current and historical dataStores current and historical data Consolidates data for management analysis and decision makingConsolidates data for management analysis and decision making Data Warehousing and Datamining DATABASE TRENDS

7.44 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Components of a Data Warehouse DATABASE TRENDS Figure 7-19

7.45 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Data mart Subset of data warehouseSubset of data warehouse Contains summarized or highly focused portion of data for a specified function or group of usersContains summarized or highly focused portion of data for a specified function or group of users Data Warehousing and Datamining DATABASE TRENDS

7.46 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Datamining Tools for analyzing large pools of dataTools for analyzing large pools of data Find hidden patterns and infer rules to predict trendsFind hidden patterns and infer rules to predict trends Data Warehousing and Datamining DATABASE TRENDS

7.47 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Improved and easy accessibility to informationImproved and easy accessibility to information Ability to model and remodel the dataAbility to model and remodel the data Benefits of Data Warehouses DATABASE TRENDS

7.48 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Databases and the Web Hypermedia database Organizes data as network of nodesOrganizes data as network of nodes Links nodes in pattern specified by userLinks nodes in pattern specified by user Supports text, graphic, sound, video and executable programsSupports text, graphic, sound, video and executable programs DATABASE TRENDS

7.49 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources A Hypermedia Database Figure 7-20 DATABASE TRENDS

7.50 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Database server Computer in a client/server environment runs a DBMS to process SQL statements and perform database management tasksComputer in a client/server environment runs a DBMS to process SQL statements and perform database management tasks Application server Software handling all application operationsSoftware handling all application operations Databases and the Web DATABASE TRENDS

7.51 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources Linking Internal Databases to the Web Figure 7-21 DATABASE TRENDS

7.52 © 2004 by Prentice Hall Management Information Systems 8/e Chapter 7 Managing Data Resources 7 7 MANAGING DATA DATARESOURCES Chapter