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

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

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

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

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

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

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

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

Management Information Systems, 4 th Edition 17 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 Components of Database Management Systems

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

Management Information Systems, 4 th Edition 19 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 The Data Dictionary

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

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

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

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

Management Information Systems, 4 th Edition 25 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. Relational Operations (Cont.)

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

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

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

Management Information Systems, 4 th 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, 4 th Edition 33 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 Data Warehousing (Cont.)

Management Information Systems, 4 th Edition 34 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 Phases in Building a Data Warehouse

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

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