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BUSI 240Introduction to Information Systems

Tuesday & Thursday 8:05am – 9:30am

Wyant Lecture Hall

Please sign the roster on the back table.

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AOL’s Bet on Another MakeoverAOL is trying to remake itself, yet again.

The new strategy in many ways resembles the old strategy: make acquisitions to attract traffic and reverse a continuing decline in advertising and revenue from its dial-up Internet service. In the latest iteration of its do-over, it is paying $315 million to buy the liberal news commentary site The Huffington Post, not long after paying $25 million to buy TechCrunch, the Silicon Valley technology news blog. http://www.nytimes.com/2011/02/08/technology/08aol.html?_r=2&ref=technology

Current Events – What’s going on?

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Verizon Has Already Sold 500,000 iPhonesEstimates place the number of iPhone 4s sold by Verizon Wireless during its short-lived pre-sale at more than half a million.

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JPMorgan analyst Phil Cusick said in a note to clients today that it's likely 500,000 people purchased an iPhone 4 from Verizon Wireless during the 17-hour-long pre-sale that took place on February 3.

In order to reach this estimate, Cusick looked back at some clues given by Verizon Wireless in the past. http://www.informationweek.com/blog/main/archives/2011/02/verizon_has_alr.html

Current Events – What’s going on?

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Quiz #2

Should have been taken by now.

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Assignment #2

Select a product to evaluate: Digital camera Cell phone MP3 player Car Computer

Follow the steps on the spreadsheet to evaluate three models of the product

Due February 22nd Submit assignment to eComanion’s Drop Box

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Assignment #2

Web sites with product reviews:www.cnet.comwww.consumerreports.orgwww.consumersearch.comwww.epinions.comreview.zdnet.comwww.consumerreview.com

Data Resource Management

Data ConceptsDatabase Management

Types of Databases

Chapter

5a

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved.

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Examples of logical data elements

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Fundamental Data Concepts

Character: single alphabetic, numeric or other symbolField or data item: a grouping of related characters

Represents an attribute (a characteristic or quality) of some entity (object, person, place or event)

Example: salaryRecord: grouping of all the fields used to describe the

attributes of an entityExample: payroll record with name, SSN and rate of

pay

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Fundamental Data Concepts

File or table: a group of related recordsDatabase: an integrated collection of logically related

data elements

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Electric Utility Database

Source: Adapted from Michael V. Mannino, Database Application Development and Design(Burr Ridge, IL: McGraw-Hill/Irwin, 2001), p. 6.

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Database Structures

HierarchicalNetworkRelationalObject-orientedMultidimensional

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Hierarchical Structure

Early DBMS structureRecords arranged in tree-like structureRelationships are one-to-many

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Hierarchical Structure

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Network Structure

Used in some mainframe DBMS packagesMany-to-many relationships

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Network Structure

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Relational Structure

Most widely used structureData elements are viewed as being stored in tablesRow represents recordColumn represents fieldCan relate data in one file with data in another file if

both files share a common data elementProvide more flexibility than hierarchical databases

because they allow users to easily receive information in response to ad hoc queries.

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Relational Structure

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Relational Operations

Select: Create a subset of records that meet a stated

criterionExample, select employees who make more than

$30,000Join

Combine two or more tables temporarilyLooks like one big table

ProjectCreate a subset of columns in a table

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Multidimensional Structure

Variation of relational modelUses multidimensional structures to organize

dataData elements are viewed as being in cubesPopular for analytical databases that support

Online Analytical Processing (OLAP)

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Multidimensional Model

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Object-oriented Structure

Object consists ofData values describing the attributes of an entityOperations that can be performed on the data

Encapsulation: Combine data and operations

Inheritance: New objects can be created by replicated some

or all of the characteristics of parent objects

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Object-oriented Structure

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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Object-oriented Structure

Used in Object-oriented database management systems (OODBMS)

Supports complex data typesExamples, graphic images, video clips, web

pages

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Evaluation of Database Structures

HierarchicalWorked for structured routine transaction

processingCan’t handle many-to-many relationships

NetworkMore flexible than hierarchicalUnable to handle ad hoc requests

RelationalEasily respond to ad hoc requestsEasier to work with and maintainNot as efficient or quick as hierarchical or network

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Database Development

Database Administrator (DBA)In charge of enterprise database development

Data Definition Language (DDL)Develop and specify the data contents,

relationships and structureThese specifications are stored in data dictionary

Data dictionaryData base catalog containing metadataMetadata – data about data

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Database Development

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Data Planning Process

Enterprise ModelDefines basic business process of the enterpriseDefined by DBAs and designers with end users

Data ModelingRelationships between data elementsEntity Relationship Diagram (ERD) common tool

for modeling

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Entity Relationship Diagram

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Database Design Process

Logical designSchema – overall logical view of relationshipsSubschema – logical view for specific end usersData models for DBMS

Physical designHow data are to be stored and accessed on

storage devices

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Logical and Physical Database Views