Transcript Management Information Systems

Chapter 8
Data and Knowledge Management
Management Information Systems, 4th Edition
1
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
2
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
3
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
4
Managing Digital Data (Cont)
Management Information Systems, 4th Edition
5
Managing Digital Data (Cont.)
Management Information Systems, 4th Edition
6
Managing Digital Data (Cont.)
Management Information Systems, 4th Edition
7
Managing Digital Data (Cont.)
Management Information Systems, 4th Edition
8
Managing Digital Data (Cont.)
Management Information Systems, 4th Edition
9
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
10
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
11
The Hierarchical Model
Management Information Systems, 4th Edition
12
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
13
The Network Model (Cont.)
Management Information Systems, 4th Edition
14
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
15
The Relational Model (Cont.)
Management Information Systems, 4th Edition
16
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
17
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
18
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
19
Relational Databases:
Design and Keys (Cont.)
Management Information Systems, 4th Edition
20
Relational Databases:
Design and Keys (Cont.)
Management Information Systems, 4th Edition
21
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
22
Components of Database
Management Systems (Cont.)
Management Information Systems, 4th Edition
23
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
24
The Data Dictionary (Cont.)
Management Information Systems, 4th Edition
25
Data Definition Language (DDL)
• Used to construct the schema
• Usually transparent to user of modern relational
DBMS
Management Information Systems, 4th Edition
26
Data Definition Language (Cont.)
Management Information Systems, 4th Edition
27
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
28
Data Manipulation Language
(DML)
Management Information Systems, 4th Edition
29
Relational Operations
• Data Manipulation
– Select, Project, Join
• Structured Query Language (SQL)
– International standard DDL and DML for
relational DBMS
Management Information Systems, 4th Edition
30
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
31
Relational Operations (Cont.)
Management Information Systems, 4th Edition
32
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
33
Database Architecture (Cont.)
Management Information Systems, 4th Edition
34
Database Architecture (Cont.)
Management Information Systems, 4th Edition
35
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
36
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
37
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
38
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
39
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
40
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
41
Phases in Building a Data
Warehouse (Cont.)
Management Information Systems, 4th Edition
42
Data Mining and Online Analysis
• Data mining
– Sequence or path analysis
– Classification
– Clustering
– Forecasting
Management Information Systems, 4th Edition
43
Data Mining and Online Analysis
(Cont.)
Management Information Systems, 4th Edition
44
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
45
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
46
Ethical and Societal Issues
Every 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
47
Ethical and Societal Issues
A 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
48
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
49