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Transcript
Essentials of Management Information Systems
Chapter 7
Chapter 7 Managing Data Resources
Managing Data Resources
7.1
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Case Study
• United Asset Coverage (UAC) is a provider of
maintenance services for office equipment
• Problem: data used by sales, marketing, customer
service, and accounting department were scattered
in several isolated information systems
• Solution: E-business suite to organize data based
on an enterprise-wide relational database
7.2
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Objectives
1. Why do businesses have trouble finding the
information they need in their information
systems?
2. How does a database management system help
businesses improve the organization of their
information?
7.3
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Objectives
3. How do the principal types of database models
affect the way businesses can access and use
information?
4. What are the managerial and organizational
requirements of a database environment?
5. What new tools and technologies can make
databases more accessible and useful?
7.4
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Management Challenges
1. Organizational obstacles to a database
environment
2. Cost/benefit considerations
7.5
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
File Organization Terms and Concepts
• Bit: Smallest unit of data; binary digit (0,1)
• Byte: Group of bits that represents a single
character
• Field: Group of words or complete number
• Record: Group of related fields
• File: Group of records of the same type
7.6
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
File Organization Terms and Concepts
• Database: Group of related files
• Entity: Person, place, thing, or event about which
information must be kept
• Attribute: A piece of information describing a
particular entity
• Key field: Field that uniquely identifies every
record in a file
7.7
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
The data hierarchy
Figure 7-1
7.8
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
Entities and attributes
Figure 7-2
7.9
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
Problems with the Traditional File Environment
• Data redundancy
• Program-data dependence
• Lack of flexibility
• Poor security
• Lack of data-sharing and availability
7.10
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Organizing Data in a Traditional File Environment
Traditional file processing
Figure 7-3
7.11
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Database Management Systems
Database
• Collection of centralized data
• Controls redundant data
• Data stored so as to appear to users in one location
• Services multiple application
7.12
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
The contemporary database environment
Figure 7-4
7.13
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Database Management Systems
Database Management System (DBMS)
• Creates and maintains databases
• Eliminates requirement for data definition
statements
• Acts as interface between application programs
and physical data files
• Separates logical and physical views of data
7.14
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Database Management Systems
Three Components to a DBMS
1. Data definition language: Formal language
programmers use to specify structure of database
2. Data manipulation language: For extracting data
from database, e.g. SQL
3. Data dictionary: Tool for storing, organizing
definitions of data elements and data
characteristics
7.15
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Sample data dictionary report
Figure 7-5
7.16
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Database Management Systems
How a DBMS Solves Problems of a
Traditional File Environment
•
•
•
•
•
7.17
Reduces data redundancy
Eliminates data inconsistency
Uncouples programs from data
Increases access and availability of data
Allows central management of data, data use, and
security
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Relational DBMS
• Represents data as two-dimensional tables called
relations
• Relates data across tables based on common data
element
• Examples: DB2, Oracle, MS SQL Server
7.18
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
The relational data model
Figure 7-6
7.19
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Three Basic Operations in a Relational
Database
• Select: Creates subset of rows that meet specific
criteria
• Join: Combines relational tables to provide users
with information
• Project: Enables users to create new tables
containing only relevant information
7.20
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
The three basic operations of a relational DBMS
Figure 7-7
7.21
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Hierarchical DBMS
• Older system presenting data in tree-like structure
• Models one-to-many parent-child relationships
• Found in large legacy systems requiring intensive highvolume transactions: Banks; insurance companies
• Examples: IBMs IMS
7.22
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
A hierarchical database for a human resources system
Figure 7-8
7.23
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Network DBMS
• Older logical database model
• Models many-to-many parent-child relationships
• Example: Student – course relationship: Each
student has many courses; each course has many
students
7.24
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
The network data model
Figure 7-9
7.25
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Disadvantages of Hierarchical and
Network DBMS
• Outdated
• Less flexible compared to RDBMS
• Lack support for ad-hoc and English language-like
queries
7.26
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
The Database Approach to Data Management
Types of Databases
Object-Oriented Databases (OODBMS)
• Stores data and procedures as objects
• Better able to handle graphics and recursive data
• Data models more flexible
• Slower than RDBMS
• Hybrid: object-relational DBMS
7.27
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Designing Databases
Two Design Exercises in Creating Database
• Conceptual (logical) design: Abstract model of
database from business perspective
• Physical design: How the database is actually
arranged on direct access storage devices
7.28
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Designing Databases
Conceptual Database Design
• Identifies relationships between data elements
• Identifies most efficient way to group data
elements
• Identifies redundant data elements
• Identifies grouping of data elements needed for
specific applications
7.29
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Designing Databases
Entity-Relationship Diagram
A methodology for documenting databases that
illustrates the relationship between various
elements in the database
Normalization
The process of creating small, stable, and adaptive
relations (tables) from complex groups of data
when designing a relational database
7.30
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
An entity-relationship diagram
Figure 7-10
7.31
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
An unnormalized relation for ORDER
Figure 7-11
7.32
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
A normalized relation for ORDER
Figure 7-12
7.33
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Distributing Databases
Distributed Database
•
•
•
•
•
•
7.34
Partitioned or replicated to more than one location
Increases service and responsiveness
Reduces vulnerability of single, massive central site
Depend on telecommunication lines
Pose security risks through distribution of sensitive data
Central data must be updated or justified with local data
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Distributed databases
Figure 7-13
7.35
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Key organizational elements in the database environment
Figure 7-14
7.36
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Management Requirements for Database Systems
Data Administration
•
•
•
•
Develop information policy
Define information requirements
Plan for data
Oversee logical database design and database
dictionary development
• Monitor use of information
7.37
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Creating a Database Environment
Management Requirements for Database Systems
Data Planning and Modeling Methodology
• Enterprise-wide planning for data
• Identify key entities, attributes, and relationships
that constitute the organization’s data
7.38
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Multidimensional Data Analysis
Online Analytical Processing (OLAP)
• Multidimensional data analysis
• Enables users to view the same data in different
ways using multiple dimensions
• Each aspect of information – product, price,
region – represents a different dimension
7.39
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Multidimensional data model
Figure 7-15
7.40
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Data Warehouses and Datamining
• Data warehouse: Stores current and historical data
for reporting, analysis
• Data mart: Subset of data warehouse with
summary of data for specific users
• Datamining: Techniques to find hidden patterns,
relationships in large pools of data to infer rules
for predicting future trends
7.41
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Components of a data warehouse
Figure 7-16
7.42
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Data Warehouses and Datamining
Benefits of Data Warehouses
• Improved information and accessibility
• Ability to model and remodel data
• Enable access to data without affecting
performance of underlying operational legacy
systems
7.43
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Window on Management
Data Reveal New Sales Opportunities
• How did the use of data warehouses and
datamining help management at these companies
make better decisions?
• What value do these systems provide?
7.44
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Data Warehouses and Datamining
Hypermedia database
• Organizes data as network of nodes
• Links nodes in pattern specified by user
• Supports text, graphic, sound, video and
executable programs
7.45
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
A hypermedia database
Figure 7-17
7.46
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Databases and the Web
Linking Internal Databases to the Web
• Database server:
– Hosts DBMS
– Receives SQL requests
– Provides required data
• Middleware:
– Works between Web server and DBMS to take requests
– Handles connectivity to database
– Can be application server in PHP or CGI scripts
7.47
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Linking internal databases to the Web
Figure 7-18
7.48
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Database Trends
Databases and the Web
Advantages to Web Access to Databases
• Browser software easy to use; little training
• Web interface requires no changes to internal
database
• Costs less than custom interfaces
7.49
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Databases in the Cloud
Contemporary Hardware Trends
• Cloud Computing:
• A model of computing in which firms and individuals
obtain computing resources over the Internet
• Cloud infrastructure as a service
• Cloud platform as a service
• Cloud software as a service
• Public vs. private clouds
• Utility computing, on-demand computing
• Data storage security is in hands of provider
7.50
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Databases in the Cloud
Cloud Computing Platform
In cloud computing,
hardware and
software capabilities
are provided as
services over the
Internet. Businesses
and employees have
access to
applications and IT
infrastructure
anywhere at any time
using an Internetconnected device.
7.51
© Prentice Hall
Essentials of Management Information Systems
Chapter 7 Managing Data Resources
Databases in the Cloud
• Cloud computing providers offer database
management services, but typically with
less functionality
• By moving to a cloud solution, companies
are able to scale their computing resources
in response to real-time demand while
keeping costs low
7.52
© Prentice Hall