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Transcript of Data Resource Management Chapter 5 Copyright © 2010 by the McGraw-Hill Companies, Inc. All rights...
Data Resource Management
Chapter 5
Copyright © 2010 by the McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin
5-2
Learning Objectives
Explain the business value of implementing data resource management processes and technologies in an organization
Outline the advantages of a database management approach to managing the data resources of a business, compared with a file processing approach
Explain how database management software helps business professionals and supports the operations and management of a business
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Learning Objectives
Provide examples to illustrate the following concepts– Major types of databases
– Data warehouses and data mining
– Logical data elements
– Fundamental database structures
– Database development
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Fundamental Data Concepts
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Database Management
In all Information Systems, data resources must be organized in a logical manner so that:
1- They can be accessed easily
2- Processed efficiently
3- Retrieved quickly
4- Managed effectively
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Logical Data Elements
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Logical Data Elements
Field(data item)
RecordCharacter
•a grouping of related characters
•Represents an attribute (quality or characteristic) of some entity (object, person, place, event)
•Examples… salary, job title
•Grouping of all the fields used to describe the attributes of an entity
•Example… payroll records with name, SSN, pay rate
•A single alphabetic, numeric, or other symbol
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Logical Data Elements
File(table, flat file)
Database
•Group of related records
•Integrated collection of logically related data elements
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Electric Utility Database
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Database Structure
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Database Structures
1. Hierarchical
2. Network
3. Relational
4. Object-oriented
5. Multidimensional
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Common Database Structures: Hierarchical
– Early DBMS structure– Records arranged in tree-like structure– Relationships are one-to-many– Access data elements by moving progressively downward from the root and along
the branches of the tree
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Common Database Structures: Network
– Used in some mainframe DBMS packages
– Many-to-many relationships Any data element can be related to any number of other data elements
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Common Database Structures: Relational
Most widely used structure
– Data elements are stored in tables– Row represents a record; column is a field– Can relate data in one file with data in another,
if both files share a common data element
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Relational operations
Relational operations include:
– Select… Create a subset of records that meet a stated criterion. Example: employees earning more than $30,000
– Join…
Combine two or more tables temporarily.
Looks like one big table.
– Project…
Create a subset of columns in a table
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Common Database Structures: Multidimensional
Variation of relational model– Uses multidimensional structures to
organize data
– Data elements are viewed as being in cubes
– Popular for analytical databases that support Online Analytical Processing (OLAP)
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Multidimensional Model
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Common Database Structures: Object-Oriented
Source: Adapted from Ivar Jacobsen, Maria Ericsson, and Ageneta Jacobsen, The Object Advantage: Business Process Reengineering with Object Technology (New York: ACM Press, 1995), p. 65.
Copyright @ 1995, Association for Computing Machinery. By permission.
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Common Database Structures: Object-Oriented
An object consists of
– Data values describing the attributes of an entity
– Operations that can be performed on the data
Encapsulation
– Combine data and operations
Inheritance
– New objects can be created by replicating some or all of the characteristics of parent objects
Used in object-oriented database management systems (OODBMS)
Supports complex data types more efficiently than relational databases– Examples: graphic images, video clips, web pages
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Evaluation of Database Structures
Hierarchical
•Works for structured, routine transactions
•Can’t handle many-to-many relationship
•Unable to handle ad hoc requests
Network
•More flexible than hierarchical
•Unable to handle ad hoc requests
Relational
•Easily responds to ad hoc requests
•Easier to work with & maintain
•Not as efficient or quick as hierarchical or network
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Database Development
Database Administrator (DBA)
In charge of enterprise-wide database development
Improves integrity and security of organizational databases
Uses Data Definition Language (DDL) to develop and specify data content, relationships, and structure
Stores these specifications in a data dictionary or metadata repository
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Data Dictionary
Data Dictionary
Contains data about data (metadata)
Relies on specialized software component to manage a database of data definitions
Can be active or passive
Contains information
on…
Security
Database maintenance
Requirements for end users’ access and use of applications
Names and descriptions of all types of data records and their interrelationships
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Example of a Data Dictionary
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Data Resource Management
Data resource management is a managerial activity– Uses data management, data warehousing,
and other IS technologies
– Manages data resources to meet the information needs of business stakeholders
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Case 2: Applebee’s, Travelocity, and Others
Applebee’s– Uses data for basic business decisions, such as
replenishing food supplies based on how much finished product was sold daily
– Developing more sophisticated analyses that look at how well items are selling
This will help the company make better decisions about what to order and what products to promote
Today, organizations extensively aggregate and mine their data to make better decisions– Travelocity mined 600,000 comments so it could
better monitor and respond to customer issues
5-26
Case Study Questions
What are the business benefits of taking the time and effort required to create and operate data warehouses such as those described in the case?
– Do you see any disadvantages?
– Is there any reason why all companies shouldn’t use data warehousing technology?
Applebee’s noted some of the unexpected insights obtained from analyzing data about “back-of-house” performance
– Using your knowledge of how a restaurant works, what other interesting questions would you suggest to the company?
5-27
Case Study Questions
Data mining and warehousing technologies use data about past events to inform better decision-making in the future
– Do you believe this stifles innovative thinking, causing companies to become too constrained by the data they are already collecting to think about unexplored opportunities?
5-28
Types of Databases
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Operational Databases
Stores detailed data needed to supportbusinesses and operations
Also called subject area databases (SADB), transaction databases, and
production databases
Database examples:customer databases, human resource
databases, inventory databases
5-30
Distributed Databases
Distributed databases are copies or parts of databases stored on servers at multiple locations
Advantages Disadvantages
Protection of valuable data
Data can be distributed into smaller databases
Each location has control of its local data
All locations can access any data, anywhere
Improved database performance at worksites
Maintaining data accuracy
5-31
Distributed Databases
Look at each distributed database and find changes
Apply changes to each distributed database
Very complex
One database is master
Duplicate the master after hours, in all locations
Easier to accomplish
Requires extra computing power & bandwidth
Duplication
Replication
Updating data can be done in 2 ways:
5-32
External Databases
Databases available for a fee from the Web, or from commercial
online services
Search engines like Google or Yahooare external databases
Hypermedia databases
Statistical databases
Bibliographic andfull-text databases
5-33
Components of Web-Based System
A hypermedia database contains– Website database– Consist of hyperlinked pages of multimedia– Interrelated hypermedia page elements,
rather than interrelated data records
5-34
Data Warehouses
Central source of data that has been cleaned,transformed, and cataloged
Stores static data that has been extracted fromother databases in an organization
Subsets of data that focus on specific aspects of a company (department or process)
Data warehouses may be divided into data marts
Data is used for data mining, analytical processing, analysis, research, decision support
5-35
Data Warehouse Components
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Applications and Data Marts
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Data Mining
5-385-38
Data Mining
Data in data warehouse are analyzed to reveal hidden patterns and trends
Examples:
– Perform market-basket analysis to identify new business processes
– Find root causes to quality problems
– Cross sell to existing customers
– Profile customers with more accuracy
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5-40
Data Mining
5-41
Traditional File Processing
Data are organized, stored, and processedin independent files
Each business application uses specialized data files containing specific types of data records
Problems
Data redundancy
Lack of data integration
Data dependence (files, storage devices, software)
Lack of data integrity or standardization
5-42
Traditional File Processing - Banks
5-43
Database Management Approach
The foundation of modern methodsof managing organizational data
The foundation of modern methodsof managing organizational data
A database management
system (DBMS) is the software
interface between users and databases
Consolidates data records,
formerly in separate files, into databases
Data can be accessed by
many different application programs
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Database Management Approach
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Database Management System
In mainframe and server computer systems, database management software is used to…In mainframe and server computer systems, database management software is used to…
Create new databasesand database applications
Maintain the quality of the datain an organization’s databases
Use the databases of an organization toprovide the information needed by end users
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Common DBMS Software Components
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Database Management System
Database Development– Defining and organizing the content, relationships,
and structure of the data needed to build a database
Database Application Development– Using DBMS to create prototypes of queries, forms,
reports, Web pages
Database Maintenance– Using transaction processing systems and other
tools to add, delete, update, and correct data
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DBMS Major Functions
5-49
Database Interrogation
End User Makes DBMS
Query
End User Makes DBMS
Query
Response is a video displayor a printed report
QueryLanguage
Immediate response to ad hoc
data requests
Report Generator
Quickly specifya format for
information you want to present
as a report
No programming required
5-50
Database Interrogation
SQL Queries– Structured, international standard query
language found in many DBMS packages– Query form is SELECT…FROM…WHERE…
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Database Interrogation
Boolean Logic– Developed by George Boole in the mid-1800s
– Used to refine searches to specific information
– Has three logical operators: AND, OR, NOT
Example– Cats OR felines AND NOT dogs OR Broadway
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Database Interrogation
Most DBMS packages offer easier-to-usepoint-and-click methods
Translates queries into SQL commands
It is difficult to correctly phrase SQL andother database language search queries
Natural language query statements aresimilar to conversational English
Graphical and Natural Queries
5-53
Microsoft Query Wizard
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Database Maintenance
Accomplished by transaction processing systems and other applications, with the support of the DBMS– Done to reflect new business transactions
and other events
– Updating and correcting data, such as customer addresses
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Application Development
Use DBMS software development toolsto develop custom application programs
Not necessary to develop detailed data-handling procedures using conventional
programming languages
Can include data manipulation language (DML) statements that call on the DBMS to
perform necessary data handling
5-56
Case 3: Amazon, eBay, and Google
Amazon’s data vault– Product descriptions– Prices– Sales rankings– Customer reviews– Inventory figures– Countless other layers of content
10 years & $1 billion
to build
10 years & $1 billion
to build
5-57
Case 3: Amazon, eBay, and Google
Amazon opened its data vault in 2002– 65,000 developers, businesses, and
entrepreneurs have tapped into it– Many have become business partners
eBay opened its $3 billion databases in 2003– 15,000 developers and others have registered
to use it and to access software features– 1,000 new applications have appeared– 41 percent of eBay’s listings are uploaded to
the site using these resources
5-58
Case 3: Amazon, eBay, and Google
Google recently unlocked access to its desktop and paid-search products– Dozens of Google-driven services cropped up
– Developers can grab 1,000 search results a day for free; anything more requires permission
– In 2005, the Ad-Words paid-search service was opened to outside applications