Managing Data Resources Chp 7

8/13/2019 Managing Data Resources Chp 7

1/48

7.1 2003 by Prentice Hall

7

MANAGING

DATA

RESOURCES

Chapter


2/48


Why do businesses have trouble finding

the information they need in their

information systems?

How does a database management system

help businesses improve the organization

of their information?

Essentials of Management Information SystemsChapter 7 Managing Data Resources

OBJECTIVES


3/48


How do the principal types of databasemodels affect the way businesses canaccess and use information?

What are the managerial andorganizational requirements of a data-base environment?

What new tools and technologies canmake databases more accessible anduseful?

OBJECTIVES



4/48


Organizational obstacles to a

database environment

Cost/benefit considerations

MANAGEMENT CHALLENGES



5/48


File Organization Terms and Concepts

Bit:Smallest unit of data; binary digit(0,1)

Byte:Group of bits that represents asingle character

Field:Group of words or a completenumber


ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT


6/48


Record:Group of related fields

File:Group of records of same type

Database:Group of related files





7/487.7 2003 by Prentice Hall


Data Hierarchy in a Computer System

Figure 7-1




Entity:Person, place, thing, event aboutwhich information is maintained

Attribute:Description of a particularentity

Key field:Identifier field used toretrieve, update, sort a record







Figure 7-2

Entitities and Attributes





Data redundancy

Program-Data dependence

Lack of flexibility

Poor security

Lack of data-sharing and availability


Problems with the Traditional File Environment



Traditional File Processing

Figure 7-3





THE DATABASE APPROACH TO DATA MANAGEMENT

Creates and maintains databases

Eliminates requirement for data definition

statements

Acts as interface between application

programs and physical data files

Separates logical and design views of data


Database Management System (DBMS)



The Contemporary Database Environment

Figure 7-4





Components of DBMS

Data definition language: Specifiescontent and structure of database anddefines each data element

Data manipulation language:Manipulates data in a database

Data dictionary:Stores definitions ofdata elements, and data characteristics






Sample Data Dictionary Report


Figure 7-5

i f f i S



Types of Databases

Relational DBMS

Hierarchical and Network DBMS

Object-Oriented Databases



E i l f M I f i S



Relational DBMS


Represents data as two-dimensional tablescalled relations

Relates data across tables based on commondata element

Examples: DB2, Oracle, MS SQL Server


E ti l f M t I f ti S t


18/487.18 2003 by Prentice HallFigure 7-6


Relational Data Model





Three Basic Operations in a Relational Database


Select:Creates subset of rows that meetspecific criteria

Join:Combines relational tables to provideusers with information

Project:Enables users to create new tablescontaining only relevant information




20/487.20 2003 by Prentice HallFigure 7-7



Three Basic Operations in a Relational Database





Hierarchical DBMS

Organizes data in a tree-like structure

Supports one-to-many parent-child

relationships

Prevalent in large legacy systems



Essentials of Management Information S stems



Hierarchical DBMS

Figure 7-8



Essentials of Management Information Systems


23/48



Network DBMS

Depicts data logically as many-to-manyrelationships





24/48

7.24 2003 by Prentice HallFigure 7-9


Network DBMS




25/48


Disadvantages

Outdated

Less flexible compared to RDBMS

Lack support for ad-hoc and Englishlanguage-like queries






26/48


Object-oriented DBMS:Stores data andprocedures as objects that can be

retrieved and shared automatically

Object-relational DBMS:Providescapabilities of both object-oriented and

relational DBMS


Object-Oriented databases




27/48


Conceptual design:Abstract model ofdatabase from a business perspective

Physical design:Detailed description ofbusiness information needs

CREATING A DATABASE ENVIRONMENT


Designing Databases



28/48


Entity-relationship diagram:Methodologyfor documenting databases illustrating

relationships between database entities

Normalization:Process of creating smallstable data structures from complex groups

of data



Designing Databases



29/48


An Entity-Relationship Diagram

Figure 7-10





30/48




An Unnormalized Relation of ORDER

Figure 7-11



31/48




An Normalized Relation of ORDER

Figure 7-12



32/48


Centralized database

Used by single central processor or multiple

processors in client/server network

Distributing Databases





33/48


Distributed database

Stored in more than one physical location

Partitioned database

Duplicated database

Distributing Databases





34/48


Distributed Databases

Figure 7-13





35/48


Management Requirements for Database Systems

Key elements in a database environment:

Data Administration

Data Planning and Modeling Methodology

Database Technology and Management

Users





36/48

7.36 2003 by Prentice HallFigure 7-14

sse s o ge e o o Sys e sChapter 7 Managing Data Resources


Management Requirements for Database Systems



37/48


Multidimensional Data Analysis

On-line analytical processing (OLAP)

Multidimensional data analysis

Supports manipulation and analysis of

large volumes of data from multiple

dimensions/perspectives

g yChapter 7 Managing Data Resources

DATABASE TRENDS



38/48


Multidimensional Data Model

Figure 7-15


DATABASE TRENDS



39/48


Data warehouse

Supports reporting and query tools

Stores current and historical data

Consolidates data for managementanalysis and decision making


Data Warehousing and Datamining

DATABASE TRENDS



40/48


Components of a Data Warehouse


DATABASE TRENDS

Figure 7-16



41/48


Data mart

Subset of data warehouse

Contains summarized or highly focused

portion of data for a specified function or

group of users



DATABASE TRENDS



42/48


Datamining

Tools for analyzing large pools of data

Find hidden patterns and infer rules to

predict trends



DATABASE TRENDS



43/48


Improved and easy accessibility to

information

Ability to model and remodel the data

Chapter 7 Managing Data Resources

Benefits of Data Warehouses

DATABASE TRENDS



44/48



Databases and the Web

The Web and Hypermedia database

Organizes data as network of nodes

Links nodes in pattern specified by user

Supports text, graphic, sound, video andexecutable programs

DATABASE TRENDS



45/48


A Hypermedia Database

Figure 7-17


DATABASE TRENDS



46/48


Database server

Computer in a client/server environmentruns a DBMS to process SQL statementsand perform database management tasks

Application server

Software handling all applicationoperations


Databases and the WebDATABASE TRENDS



47/48


Linking Internal Databases to the Web

Figure 7-18


DATABASE TRENDS

7Chapter


48/48

7

MANAGING

DATA

RESOURCES

Chapter

Managing Data Resources Chp 7

Documents

Transcript of Managing Data Resources Chp 7