chapter 5

1 Introduction to Information TechnologyTurban, Rainer and Potter

Chapter 5 Managing Organizational Data and Information

CHAPTER 5MANAGING ORGANIZATIONAL DATA AND INFORMATION



Learning Objectives Discuss traditional data file organization and its problems Explain how a database approach overcomes the problems

associated with traditional file environment, and discuss the advantages of the database approach

Describe how the three most common data models organize data, and the advantages and disadvantages of each model

Describe how a multidimensional data model organizes data Distinguish between a data warehouse and a data mart Discuss the similarities and difference between data mining and

text mining



Chapter OverviewBasics of Data Arrangement and Access• The Data Hierarchy• Storing and Accessing Records

The Traditional File Environment• Problems with the File Approach

Databases: The Modern Approach• Locating Data in Databases• Creating the Database

Database Management Systems• Logical versus Physical View• DBMS Components

Logical Data Models• Hierarchical Model• Network Model• Relational Model• Advantages and Disadvantages of the Three Models• Emerging Models• Other Models

Data Warehouse• Multidimensional Model• Data Marts• Data Mining• Text Mining



The Problem customers are classified as good , bad, or

ugly by the cost of doing business with them and the profits they return

Case: FedEx Pinpoints Profitable Customers

keep the good customers, improve the bad customers, and drop the ugly ones easy to identify customers who spend money with them but difficult to

identify customers who are profitable for them



Case (continued…)

use a data warehouse, stocked with customer data, that allows the company to compare the complex mix of marketing and servicing costs that go into retaining each individual customer versus the revenues he, she, or it might bring in

The Solution

The Results “good” customers - expect a phone call if their shipping volumes falter, which can prevent defections before they occur “bad” customers – can be turned into profitable customers by charging higher shipping rates “ugly” customers – can be ignored



What have we learned from this case??

Case (continued…)

Customized strategies can be developed to cut costs, transform the marginal customer into a profitable customer, and permit more profitable pricing structures

Other types of data can give an organization important feedback about its products, services, markets, and coming trends

Organizations can now scrutinize their customers (or other data) very carefully with advanced data management andanalysis tools



Basics of Data Arrangementand Access

The Data Hierarchy Field - a logical grouping of characters into a word, a small group of

words, or a complete number Record - a logical grouping of related fields File - a logical grouping of related records Database - a logical grouping of related files Entity - a person, place, thing, or event about which information is

maintained Attribute - each characteristic or quality describing a particular entity Primary Key - field that uniquely identifies the record Secondary Key - field that has some identifying information, but

typically does not identify the file with complete accuracy



Basics of Data Arrangementand Access (continued …)

Storing and Accessing Records Indexed Sequential Access Method (ISAM)

» uses an index of key fields to locate individual records» index - lists the key field of each record and where that record is

physically located in storage» track index - shows the highest value of the key field that can be

found on a specific track

Direct File Access Method» uses the key field to locate the physical address of a record» transform algorithm - translates the key field directly into the

record’s storage location on disk

Traditional File Environment The organization has multiple

applications with related data files


Chapter 4 Computer Software

Each application has a specific data file related to it,

containing all the data records needed by the application

Each application comes with an associated

application-specific data file



Problems with the file approach data redundancy - the same piece of information could be

duplicated in several places data inconsistency - the various copies of the data no longer

agree data isolation - difficulty in accessing data from different

applications security - new applications may be added to the system on an

ad hoc basis data integrity - data values must often meet integrity constraints application/data independence - the applications and data in

computer systems should be independent

Traditional File Environment (continued …)



Database : The Modern Approach Database Management System

provides access to all the data Example : University administration

Registrar Office Class Programs

Accounting Dept. Accounts Programs

Athletics Dept. Sports Programs

DatabaseManagement

System

Academic Info.Team DataEmployee DataTuition DataFinancial AidStudent DataCourse DataCourse Data Registration Data



Locating Data in Databases Centralized database

» all the related files are in one physical location» used on large, mainframe computers» saves the expenses associated with multiple computers» provides database administrators with the ability to work on a database as a whole at one location» files are not accessible except via the centralized host computer» recovery from disasters can be more easily accomplished at a central location» vulnerable to a single pint of failure» speed problem

Database : The Modern Approach (continued …)



Locating Data in Databases (cont’)

Distributed database» complete copies of a database, or portions of a database, are

in more than one location, which is usually close to the user» replicated database - complete copies of the entire

database are delivered to many locations, primarily to alleviate the single-point-of-failure problems of a centralized database as well as to increase user access responsiveness

» partitioned databases - these are subdivided, a portion of the entire database in each location

Database : The ModernApproach (continued …)



Centralized vs. Distributed Databases

Central Location

New York

UserNew York

UserLos Angeles

Centralized Database

Central Location

New York

UserNew York

Distributed Database

UserChicago

UserLos Angeles

UserKansas City

Chicago

New York

Kansas City

Los Angeles



Creating a Database Conceptual design - an abstract model of the database from the

user or business perspective Physical design - shows the way a database is actually arranged

with a storage devices Entity-relationship (ER) modeling

» process of planning the database design» ER diagram - document of the conceptual data model» Entity classes Instance Identifiers Relationships

Normalization » method for analyzing and reducing a relational database to its most

streamlined form for minimum redundancy, maximum data integrity, and best processing performance

Database : The ModernApproach (continued …)



Database Management Systems A software program (or group of programs) that provides access to a

databases Permits an organization to store data in one location, from which it can be

updated and retrieved Provides access to the stored data by various application programs Provides mechanisms for maintaining the integrity of stored information,

managing security and user access, recovering information when the system fails, and accessing various database functions form within an application written in a third-generation, fourth-generation, or object-oriented language



Logical versus Physical View Physical view - deals with the actual, physical

arrangement and location of data in the direct access storage devices (DASD)

Logical view - represents data in a format that is meaningful to a user and to the software programs that process that data

DBMS (continued …)



DBMS Components Data model

» defines the way data are conceptually structured

Data definition language (DDL)» defines what types of information are in the database and how

they will be structured

» functions of the DDL

> provide a means for associating related data

> indicate the unique identifiers (or keys) of the records

> set up security access and change restrictions




DBMS Components (cont’)

Data manipulation language (DML)» used with third-generation, fourth-generation, or object-

oriented languages to query the contents of the database, store or update information in the database, and develop database applications

» Structured query language (SQL) - most popular relational database language, combining both DML and DDL features

Data Dictionary» stores definitions of data elements and data characteristics




Logical Data Models A manager’s ability to use a database is highly dependent

on how the database is structured logically and physically.

In a logically structuring database, businesses need to consider the characteristics of the data and how the data will be accessed.

Three common data models : hierarchical, network, and relational

Using these models, database designer can build logical or conceptual view of data that can then be physically implemented into virtually any database with any DBMS.



Hierarchical Database Model structures data into an inverted “tree” in which each record

contains two elements rigidly

Logical Data Models (continued …)

1st : a single root or master field, often called a key, which identifies the type location or ordering of the records

2nd : a variable number of subordinate fields, which defines the rest of the data within a record

all fields have only one “parent”, each parent may have many “children” advantage : speed and efficiency problem : access to data is predefined before the programs; and each relationship

must be explicitly defined when the database is created



Hierarchical Data ModelSales

RegionEast Coast Midwest West Coast

ProductCategory

China Stemware Flatware



Plates Bowls Plates Bowls Plates Bowls Product



Network Database Model creates relationship among data through a linked-list

structure in which subordinate records (members) can be linked to more than one data element (owner)

pointer - explicit link, storage addresses that contain the location of a related record

many-to-many relationships are possible complexity : for every set of linked data elements, a

pair of pointers must be maintained




Relational Database Model based on a simple concept of tables in order to capitalize on

characteristics of rows and columns of data relations - tables tuple - row attribute - column select operation - creates a subset consisting of all records in the

file that meet stated criteria join operation - combines relational tables to provide the user

with more information than is available in individual tables project operation - creates a subset consisting of columns in a

table, permitting the user to create new tables that contain only the information required




Relational Database Model

Smith, A. Dir. Accounting 43 China

Jones, W. Dir. Total QualityManagement

32 Stemware

Lee, J. Dir. InformationTechnology

46 China

Durham, K. Manager, Production 35 Stemware

Stone, L. Administrative Asst. 28 Flatware



Company Data ModelsMODEL ADVANTAGES DISADVANTAGES

Hierarchicaldatabase

Speed and efficiency in search

Access to data is predefined by exclusively hierarchical relationships, predetermined by administrator. Limited search/ query flexibility. Not all data is naturally hierarchical.

Network database

Many more relationships between data elements can be defined. Greater speed and efficiency than relational database models.

The most complicated model to design, implement, and maintain. Greater query flexibility than hierarchical model, but less than relational model.

Relationaldatabase

Conceptual simplicity; no predefined relationships among data. High flexibility in ad hoc querying. New data and records can be added easily

Lower processing efficiency and speed. Data redundancy is common, requiring additional maintenance.



Emerging Data Models Object-oriented database model - an object - a small amount of

data put together with all the data needed in order to perform an operation with that data

» Object - similar to an entity in that it represents a person, place, or thing, but it also contains all of the data that the object needs in order to perform an operation

» Attributes - characteristics that describe the state of that object» Method - an operation, action, or a behavior the object may undergo» Messages - from other objects activate operations contained within the

object» Class - all the messages to which the object will respond, as well as the

way in which objects of this class are implemented




Emerging Data Models (cont’) Object-relational database model - adds new object storage

capabilities to relational database management systems Hypermedia database model - stores chunks of information in a form

of nodes connected by links established by the user

Other Database Models Geographical information database - contains locational data for

overlaying on maps or images Knowledge database- stores decision rules used to evaluate situations

and help users make decisions like an experts Multimedia database - stores data on many media : sounds, video,

images, graphics animation, and text.




Data Warehouses

A data warehouse is a relational and or multidimensional database management system designed to support management decision making.

The data in the “warehouse” is stored in a single, agreed-upon format even when underlying operational databases store the data differently.



Data WarehousesFramework and View

OperationalSystem/Data

Legacy

OLTT

External

Select

Extract

Transform

Maintain

Integrate

Preparation

MetadataReposition

EnterpriseData

Warehouse

Target Database(s)(RDB, MDDB)

DataMart

DataMart

DataMart

Marketing

RiskManagement

Engineering

APIS

MLDDLEWARE

Access

DataMining

ApplicationsEIS/DSS

Custom-BuiltApplication(4GL tools)

Production Reporting

Tools

Relational Query Tools

OLAP/ROLAP

Web Browsers



Data Warehouses (continued ...) Data Warehouse Offers Many Business Advantages

It provides business users with a “customer-centric” view of the company’s heterogeneous data by helping to integrate data from sales, service, manufacturing and distribution, and other customer-related business systems.

It provides added value to the company’s customers by allowing them to access better information when data warehouse is coupled with Internet technology.

It consolidates data about individual customers and provides a repository of all customer contacts for segmentation modeling, customer retention planning, and cross-sales analysis.



Data Warehouses (continued ...)

Data Warehouse Advantages (cont’)

It removes barriers among functional areas by offering a way to reconcile views from multiple sources, thus providing a look at activities that cross functional lines.

It reports on trends across multidivisional and/or multinational operating units, including trends or relationships in areas such as merchandising, production planning, and so forth.




Multidimensional Database Model can be the core of data warehouses data are stored in arrays consists of at least three dimensions dimensions are the edges of the cube, and represent the

primary “views” of the business data the data are intimately related and can be viewed and analyzed

from different perspectives, which are called dimensions allows for the effective, efficient, and convenient storage and

retrieval of large volumes of data




Data Marts a scaled-down version of a data warehouse that focuses on a

particular subject area usually designed to support the unique business requirements

of a specific department or business process. Example : Marketing data mart

takes less time to build, costs less, and less complex the indiscriminate introduction of multiple data marts with no

linkage to each other, or to an enterprise data warehouse, will cause problems




Data Mining provides a means of extracting previously unknown,

predictive information from the base of accessible data in data warehouses

discovers hidden patterns, correlations, and relationships among organizational data

predicts future trends and behaviors, allowing businesses to make proactive, knowledge-driven decisions

functions of data mining» classification » clustering » association» sequencing » forecasting



For Accounting Data gathered about each transaction (business

event) in the organization is stored in its databases

For Finance Computerized databases external to the

organization, such as CompuStat or Dow Jones, provides financial data on organizations in its industry

What’s in IT for Me?



For Marketing Databases including customer name, address,

purchase, amount, etc, help to plan targeted marketing campaigns and to evaluate the success of previous campaigns.

Data mining is critical for many marketing efforts to remain competitive.

For Production/Operations Management Organizational databases are accessed for

determining optimum inventory levels for parts in a production process

Information in databases are used to know when to perform required service on machines

What’s in IT for Me? (continued …)



For Human Resources Management Organizational databases contain extensive data

on employees, such as name, address, gender, race, age, salary, hiring date, current job descriptions, past job descriptions, and past performance evaluations

For MIS Vacancies for MIS include data entry and data

storage management to database management and data analyst

What’s in IT for Me? (continued …)

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