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Chapter 8 Data and Knowledge Management

Chapter 8 Data and Knowledge Management. Managing Digital Data. The Traditional File Approach Disadvantages Program/Data Dependency Data Redundancy Data Integrity Moving to Databases Database Management System (DBMS) Queries: Request data from specified fields

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Chapter 8 Data and Knowledge Management

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  1. Chapter 8Data and Knowledge Management Management Information Systems, 4th Edition

  2. Managing Digital Data • The Traditional File Approach • Disadvantages • Program/Data Dependency • Data Redundancy • Data Integrity • Moving to Databases • Database Management System (DBMS) • Queries: Request data from specified fields • Security: Giving users different views addresses security issue Management Information Systems, 4th Edition

  3. Managing Digital Data (Cont) Management Information Systems, 4th Edition

  4. Managing Digital Data (Cont.) Management Information Systems, 4th Edition

  5. Traditional Files vs. Databases: Pros and Cons • Traditional File Advantages • Simplicity • Efficiency • Customization • Database Advantages • Reduced data redundancy • Application/data independence • Better control • Flexibility Management Information Systems, 4th Edition

  6. The Hierarchical Model • Records are related hierarchically—each category is a subcategory of the next level up • Disadvantages of hierarchical databases • To retrieve a record, a user must start at the root and navigate the hierarchy. • If a link is broken, the entire branch is lost. • Requires considerable data redundancy Management Information Systems, 4th Edition

  7. The Hierarchical Model Management Information Systems, 4th Edition

  8. The Network Model • Allows a record to be linked to more than one parent • Supports many-to-many relationships • Advantage of the network model • Reduced data redundancy • Disadvantages of the network model • Complicated to build and difficult to maintain • Difficult to maintain and navigate Management Information Systems, 4th Edition

  9. The Network Model (Cont.) Management Information Systems, 4th Edition

  10. The Relational Model • Consists of tables; links among entities are maintained with foreign keys • Advantages of relational databases • Same advantages of a network database without the complications • Easier to conceptualize and maintain • Virtually all DBMSs offered for microcomputers accommodate the relational model Management Information Systems, 4th Edition

  11. The Relational Model (Cont.) Management Information Systems, 4th Edition

  12. The Object-Oriented Structure • Useful for data and information that cannot be organized into fields • Does not store records, but data objects • Advantages include ability to represent data dynamically • Disadvantages include dependence between applications and data Management Information Systems, 4th Edition

  13. Components of Database Management Systems • The Schema • Describes the structure of the database • The Data Dictionary (Metadata) • Maintains all information supplied by the developer when constructing the schema Management Information Systems, 4th Edition

  14. Relational Databases: Design and Keys • Data Modeling • Analyzing data and identifying relationships • Entity Relationship (ER) Diagram, a graphical representation of all entity relationships • Understand symbols when reviewing a diagram • Key: a field whose value identify records • Primary Key • Linking Management Information Systems, 4th Edition

  15. Relational Databases: Design and Keys (Cont.) Management Information Systems, 4th Edition

  16. Relational Databases: Design and Keys (Cont.) Management Information Systems, 4th Edition

  17. Components of Database Management Systems • The Schema • Describes the structure of the db • Names, types of fields, general relationships • Types of data • Numeric, alphanumeric, graphic, time-related • Building a Database Management Information Systems, 4th Edition

  18. Components of Database Management Systems (Cont.) Management Information Systems, 4th Edition

  19. The Data Dictionary • All information supplied by db developer in the schema is maintained here • Table names • Record names and types • Field names and types • Relationships among record types • Who is responsible for updating the db Management Information Systems, 4th Edition

  20. The Data Dictionary (Cont.) Management Information Systems, 4th Edition

  21. Data Definition Language (DDL) • Used to construct the schema • Usually transparent to user of modern relational DBMS Management Information Systems, 4th Edition

  22. Data Manipulation Language (DML) • Software used to query the database • Either enter a statement requesting information, or a Query by Example (QBE) • Programmers use this for developing applications Management Information Systems, 4th Edition

  23. Data Manipulation Language (DML) Management Information Systems, 4th Edition

  24. Relational Operations • Data Manipulation • Select, Project, Join • Structured Query Language (SQL) • International standard DDL and DML for relational DBMS Management Information Systems, 4th Edition

  25. Relational Operations (Cont.) • SQL (cont.) • Advantages • Users do not need to learn different DDLs and DMLs. • SQL can be embedded in widely used 3rd generation languages, increasing efficiency and effectiveness. • Programmer not forced to rewrite statements since SQL statements are portable. Management Information Systems, 4th Edition

  26. Database Architecture • Distributed Databases • Replication • Full copy of the entire database is stored at all sites • Fragmentation • Parts of database are stored where they are most often accessed Management Information Systems, 4th Edition

  27. Database Architecture (Cont.) Management Information Systems, 4th Edition

  28. Database Architecture (Cont.) Management Information Systems, 4th Edition

  29. Client/Server Systems • Four basic client/server models • Applications run at a server • Applications run on local PCs • Applications run on both the local PCs and the server • Applications and key elements of the database are split between the PCs and the server Management Information Systems, 4th Edition

  30. Databases on the Web • Catalogs • Libraries of books, articles, CDs, and movie clips • Directories • Client lists and profiles • Package tracking • Customer relationship management • Financial transactions databases Management Information Systems, 4th Edition

  31. Databases on the Web (Cont.) • Points to Consider • Which application to use • How to ensure Web surfers do not interfere with database updates • How to maintain security Management Information Systems, 4th Edition

  32. Data Warehousing • Data warehouse: a collection of data that supports management decision making • Data Mart: smaller collection of data focusing on a particular subject or department Management Information Systems, 4th Edition

  33. Data Warehousing (Cont.) • From Database to Data Warehouse • Transactional db usually not suitable for analysis because they contain current, not historical data • Hardware must meet capacity needs • Data and software and scalability must be considered Management Information Systems, 4th Edition

  34. Phases in Building a Data Warehouse • Extraction Phase • Builders create the files from transactional db and save on server • Cleansing Phase • Data is made consistent • Loading Phase • Builders transfer files to data warehouse database Management Information Systems, 4th Edition

  35. Data Mining and Online Analysis • Data mining • Sequence or path analysis • Classification • Clustering • Forecasting Management Information Systems, 4th Edition

  36. Data Mining and Online Analysis (Cont.) Management Information Systems, 4th Edition

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