490 likes | 594 Views
Chapter 8 Data and Knowledge Management. Learning Objectives. Explain the difference between traditional file organization methods and the database approach
E N D
Chapter 8Data and Knowledge Management Management Information Systems, 4th Edition
Learning Objectives • Explain the difference between traditional file organization methods and the database approach • Explain how database management systems are used to construct databases, populate them with data, and manipulate the data to produce information • Describe the different database models and the advantages and disadvantages of each model • Enumerate the most important features and operations of a relational database, the most popular database model Management Information Systems, 4th Edition
Learning Objectives (Cont.) • Illustrate how databases are changing business operations across industries and what impact they might have on our personal lives • Explain the concepts of data warehousing and data mining and their use in business and give examples of their use • Identify needs for knowledge storage and management in organizations • Give examples of the ways in which knowledge is managed in organizations Management Information Systems, 4th Edition
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
Managing Digital Data (Cont) Management Information Systems, 4th Edition
Managing Digital Data (Cont.) Management Information Systems, 4th Edition
Managing Digital Data (Cont.) Management Information Systems, 4th Edition
Managing Digital Data (Cont.) Management Information Systems, 4th Edition
Managing Digital Data (Cont.) Management Information Systems, 4th Edition
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
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
The Hierarchical Model Management Information Systems, 4th Edition
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
The Network Model (Cont.) Management Information Systems, 4th Edition
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
The Relational Model (Cont.) Management Information Systems, 4th Edition
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
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
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
Relational Databases: Design and Keys (Cont.) Management Information Systems, 4th Edition
Relational Databases: Design and Keys (Cont.) Management Information Systems, 4th Edition
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
Components of Database Management Systems (Cont.) Management Information Systems, 4th Edition
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
The Data Dictionary (Cont.) Management Information Systems, 4th Edition
Data Definition Language (DDL) • Used to construct the schema • Usually transparent to user of modern relational DBMS Management Information Systems, 4th Edition
Data Definition Language (Cont.) Management Information Systems, 4th Edition
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
Data Manipulation Language (DML) Management Information Systems, 4th Edition
Relational Operations • Data Manipulation • Select, Project, Join • Structured Query Language (SQL) • International standard DDL and DML for relational DBMS Management Information Systems, 4th Edition
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
Relational Operations (Cont.) Management Information Systems, 4th Edition
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
Database Architecture (Cont.) Management Information Systems, 4th Edition
Database Architecture (Cont.) Management Information Systems, 4th Edition
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
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
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
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
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
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
Phases in Building a Data Warehouse (Cont.) Management Information Systems, 4th Edition
Data Mining and Online Analysis • Data mining • Sequence or path analysis • Classification • Clustering • Forecasting Management Information Systems, 4th Edition
Data Mining and Online Analysis (Cont.) Management Information Systems, 4th Edition
Online Analytical Processing • Fast in response • Enables timely decision-making • Use data stored in data warehouses to derive ratios and degrees of predetermined relationships Management Information Systems, 4th Edition
Knowledge Management • The attempt by organizations to: • Transfer knowledge into databases • Filter and separate the most relevant knowledge • Organize knowledge in databases that either • Allow other employees to easily access the knowledge • “Push” specific knowledge to employees based on their prespecified needs Management Information Systems, 4th Edition
Ethical and Societal IssuesEvery Move You Make • Out of Hand -- Out of Control • DBMSs allow organizations to collect, maintain, and sell vast amounts of private personal data easily • The Web: A Source of Data Collection • Many consumers provide information daily without being aware of where it is actually going Management Information Systems, 4th Edition
Ethical and Societal IssuesA Too-Risky Info Highway • Our Finances Exposed • Personal data is distributed • Our Health Online • Benefits and risks • The Upside • Database technology enables better and faster services Management Information Systems, 4th Edition
Summary • Traditional file organization vs. database approach • How database management systems effect database development • Features and operation of a relational database • Data warehousing and data mining • Knowledge storage and management Management Information Systems, 4th Edition