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Database Management Systems

Part I: The Context of Database Management. The Database Environmentrole of databases in organizationsclassifications of databasesdatabase vs. file managementDatabase Development Processpart of the SDLCuser/analyst interactioninformation engineering and enterprise data model?. Chapter 1: Th

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Database Management Systems

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    2. Database Management Systems MIS 421 Dr. Steven C. Ross 2001

    3. Part I: The Context of Database Management The Database Environment role of databases in organizations classifications of databases database vs. file management Database Development Process part of the SDLC user/analyst interaction information engineering and enterprise data model ?

    4. Chapter 1: The Database Environment

    5. Evolution Data keyed in at run time INPUT statements Data stored in the program DATA and READ statements Data stored in program-specific files FORMAT and READ#n statements Data stored in program-independent files DBMS software ?

    6. Data Access Delimited 97071,Smith,Joe,Woodburn,OR,35.95 97754,Kleindienst,Arthur,Prineville,OR,2998.47 Fixed 97071Smith Joe Woodburn OR 35.95 97754Kleindienst Arthur Prineville OR2998.47 Sequential Random ?

    7. Disadvantages of Traditional File Systems Program-data dependence Data redundancy [duplication] Limited data sharing Excessive programming and maintenance effort Poor data control: homonyms, synonyms Inadequate data manipulation capabilities ?

    8. The Database Approach Enterprise data model high-level entities and associations among them model of organization integration of data and processes Relational databases “data should be related through natural, logical relationships inherent in the data” tables [relations] made up of rows and columns ?

    9. Data, Metadata, Programs, and Objects Data … Information Metadata Programs Objects ?

    10. Advantages of the Database Approach Program-data independence Minimal data redundancy Improved data consistency Improved data sharing Increased productivity of development staff Enforcement of standards Improved data quality Improved data accessibility Reduced program maintenance but ...

    11. Cautions, Costs, and Risks 6Ps: Prior planning prevents p[retty] poor performance New, specialized personnel needed Costly and complex to install and manage Costly to convert Backup and recovery more important Organizational/social issues ?

    12. The Range of Database Applications Personal [computer] databases one user, standalone PC Workgroup databases 1?25 users, LAN Department databases 25?100 users, linked LANs Enterprise databases >100 users, WAN, intranet, VPN ?

    13. Chapter 2: Database Development Process

    14. The Information Systems Architecture Data: enterprise data model (E-R diagram) Processes: data flow diagrams Network: location connectivity diagram People: context diagram, other DFDs Events: state transition diagrams Reasons: decision tables, repository entries ?

    15. Information Engineering Planning Analysis Design Implementation ?

    16. Information Systems Planning Step 1: Identify strategic planning factors goals: what we want to achieve critical success factors: things we must accomplish if we are to succeed problem areas: known weaknesses ?

    17. Information Systems Planning Step 2: Identify corporate planning objects organizational units: how the people (and resources) are organized organizational locations: where they work business functions: what they do entity types: what they keep track of information systems: existing or proposed systems ?

    18. Information Systems Planning Step 3: Develop an enterprise model functional decomposition diagram(s) enterprise data model matrices [matrixes] location by function unit by function information system by data entity function by data entity information system by objective ?

    19. Strategic Database Planning [another way of looking at the issues] Five year plan information needs of the functional areas information needs of the levels of management information needs of geographical locations model of the information needs anticipated data volumes by location preliminary estimate of costs recommendations for detailed development ?

    20. A Different Version of the SDLC Project identification and selection Project initiation and planning Analysis Logical design Physical design Implementation Maintenance ?

    21. Database Development during the SDLC Project identification and selection – enterprise modeling Project initiation and planning & Analysis – conceptual data modeling Logical design – logical database design Physical design – physical database design and creation Implementation – database implementation Maintenance – database maintenance ?

    22. Rapid Application Development Prototyping identify problem develop initial prototype implement and use prototype ?? revise and enhance prototype convert to operational system ?

    23. CASE and Repository Drawing Code generation Repository ?

    24. Three-Level Database Architecture External level users Conceptual level systems analysts Internal level database programmers/specialists ?

    25. Three-Tiered Database Location Architecture Client tier Department tier Enterprise tier ?

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