5-1 McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved

5-1McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved.

Data Resource Management

Data ConceptsDatabase Management

Types of Databases

Chapter

5

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

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Learning Objectives

1. Explain the business value of implementing data resource management processes and technologies in an organization.

2. Outline the advantages of a database management approach to managing the data resources of a business, compared to a file processing approach.

3. Explain how database management software helps business professionals and supports the operations and management of a business.

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Learning Objectives

4. Provide examples to illustrate each of the following concepts:

a. Major types of databasesb. Data warehouses and data miningc. Logical data elementsd. Fundamental database structurese. Database development

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Case 1: Harrah’s Entertainment and Others

For casinos, one of their most important assets is the data about the high-roller customers

What steps can be taken to prevent employees from stealing this data?ManagerialLegalTechnical

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Case Study Questions

1. Why have developments in IT helped to increase the value of the data resources of many companies?

2. How have these capabilities increased the security challenges associated with protecting a company’s data resources?

3. How can companies use IT to meet the challenges of data resource security?

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Examples of logical data elements

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Fundamental Data Concepts

Character: single alphabetic, numeric or other symbol

Field or data item: a grouping of related charactersRepresents an attribute (a characteristic or quality)

of some entity (object, person, place or event)Example: salary

Record: 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 element

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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