Data Resource Management

Chapter 5

Copyright © 2010 by the McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin

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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

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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Logical Data Elements

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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

5-12Database Systems, 9th Edition

CEO

Marketing manager

OperationManager

Finance Manager

Employee 1

Employee 2

Employee 3

Employee 5

Employee 4

Employee 6

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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

5-14Database Systems, 9th Edition

Ms. Ghada Ms. Anwar Ms. Mashael

Principles of MIS

Microeconomics Accounting Legal Environment

Student 1 Student 2 Student 3 Student 4 Student 5 Student 6

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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

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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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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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

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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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

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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

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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:

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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

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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

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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

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Data Warehouse Components

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Applications and Data Marts

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Data Mining

Data in data warehouse are analyzed to reveal hidden patterns and trends

Examples:

– Perform market-basket analysis to identify new products

– Find root causes to quality problems

– Cross sell to existing customers

– Profile customers with more accuracy

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Data Mining