ch01

Chapter 1Chapter 1Data: The New Data: The New

Corporate ResourceCorporate ResourceFundamentals of Database Management Systems,

2nd edby

Mark L. Gillenson, Ph.D.

University of Memphis

John Wiley & Sons, Inc.

1-1-22

Chapter ObjectivesChapter Objectives

♦ Explain why humankind’s interest in data Explain why humankind’s interest in data goes back to ancient times.goes back to ancient times.

♦ Describe how data needs have historically Describe how data needs have historically driven many information technology driven many information technology developments.developments.

♦ Describe the evolution of data storage Describe the evolution of data storage media during the last century.media during the last century.

1-1-33

Chapter ObjectivesChapter Objectives

♦ Relate the idea of data as a corporate Relate the idea of data as a corporate resource that can be used to gain a resource that can be used to gain a competitive advantage to the development competitive advantage to the development of the database management systems of the database management systems environment.environment.

1-1-44

DataData

♦ Data - the foundation of technological activityData - the foundation of technological activity

♦ Database - a highly organized collection of Database - a highly organized collection of assembled dataassembled data

♦ Database Management System - sophisticated Database Management System - sophisticated software that controls the database and the software that controls the database and the database environmentdatabase environment

1-1-55

What is Data?What is Data?

♦ A single piece of data is a single fact about A single piece of data is a single fact about something that interests us.something that interests us.

♦ A fact can be any characteristic of an object.A fact can be any characteristic of an object.

1-1-66

History of DataHistory of Data

♦ People have been interested in data for at People have been interested in data for at least the past 12,000 years.least the past 12,000 years.

♦ Non-computer, primitive methods of data Non-computer, primitive methods of data storage and handling.storage and handling.

1-1-77


♦ Shepherds kept track of their flocks with Shepherds kept track of their flocks with pebbles.pebbles.

♦ A primitive but legitimate example of data A primitive but legitimate example of data storage and retrieval.storage and retrieval.

1-1-88


♦ Dating back to 8500 B.C., unearthed clay tokens or “counters” may Dating back to 8500 B.C., unearthed clay tokens or “counters” may have been used for record keeping in primitive forms of accounting.have been used for record keeping in primitive forms of accounting.

♦ Tokens, with special markings on them, were sealed in hollow clay Tokens, with special markings on them, were sealed in hollow clay vessels that accompanied commercial goods in transit.vessels that accompanied commercial goods in transit.

1-1-99

Data Through the AgesData Through the Ages

♦ Record-keeping - the recording of data to Record-keeping - the recording of data to keep track of how much a person has keep track of how much a person has produced and what it can be bartered or produced and what it can be bartered or sold for.sold for.

♦ With time, different kinds of data were keptWith time, different kinds of data were kept♠ calendars, census data, surveys, land calendars, census data, surveys, land

ownership records, marriage records, records ownership records, marriage records, records of church contributions, family trees, etc.of church contributions, family trees, etc.

1-1-1010


♦ Double-entry bookkeeping - originated in the Double-entry bookkeeping - originated in the trading centers of fourteenth century Italy.trading centers of fourteenth century Italy.

♦ The earliest known example is from a merchant The earliest known example is from a merchant in Genoa and dates to the year 1340.in Genoa and dates to the year 1340.

1-1-1111

Early Data Problems Spawn Early Data Problems Spawn Calculating DevicesCalculating Devices

♦ People interested in devices that could People interested in devices that could “automatically” process their data.“automatically” process their data.

♦ Blaise Pascal produced an adding Blaise Pascal produced an adding machine that was an early version of machine that was an early version of today’s mechanical automobile today’s mechanical automobile odometers.odometers.

1-1-1212

Punched Cards - Data StoragePunched Cards - Data Storage

♦ Invented in 1805 by Joseph Marie Jacquard of Invented in 1805 by Joseph Marie Jacquard of France.France.

♦ Jacquard’s method of storing fabric patterns, a Jacquard’s method of storing fabric patterns, a form of graphic data, as holes in punched cards form of graphic data, as holes in punched cards was a very clever means of data storage.was a very clever means of data storage.

♦ Of great importance for computing devices to Of great importance for computing devices to follow.follow.

1-1-1313

Era of Modern Information Era of Modern Information ProcessingProcessing

♦ The 1880 U.S. Census took about seven years to The 1880 U.S. Census took about seven years to compile by hand.compile by hand.

♦ Basing his work on Jacquard’s punched card concept, Basing his work on Jacquard’s punched card concept, Herman Hollerith arranged to have the census data Herman Hollerith arranged to have the census data stored in punched cards and invented machinery to stored in punched cards and invented machinery to tabulate them.tabulate them.

♦ In 1896 Hollerith formed the Tabulating Machine In 1896 Hollerith formed the Tabulating Machine Company to produce and commercially market his Company to produce and commercially market his devices -- this later became IBM.devices -- this later became IBM.

1-1-1414

Era of Modern Information Era of Modern Information ProcessingProcessing

♦ James Powers developed devices to James Powers developed devices to automatically feed cards into the automatically feed cards into the equipment and to automatically print equipment and to automatically print results.results.

♦ In 1911 he established the Powers In 1911 he established the Powers Tabulating Machine Company -- this later Tabulating Machine Company -- this later became Unisys Corporation.became Unisys Corporation.

1-1-1515

The Mid-1950sThe Mid-1950s

♦ The introduction of electronic computers.The introduction of electronic computers.

♦ Witnessed a boom in economic Witnessed a boom in economic development.development.

♦ From this point onward, it would be From this point onward, it would be virtually impossible to tie advances in virtually impossible to tie advances in computing devices to specific, landmark computing devices to specific, landmark data storage and retrieval needs.data storage and retrieval needs.

1-1-1616

Modern Data Storage MediaModern Data Storage Media

♦ Punched paper tape - The earliest form of Punched paper tape - The earliest form of modern data storage, introduced in the modern data storage, introduced in the 1870s and 1880s.1870s and 1880s.

♦ Punched cards were the only data storage Punched cards were the only data storage medium used in the increasingly medium used in the increasingly sophisticated electromechanical sophisticated electromechanical accounting machines of the 1920s, 1930s, accounting machines of the 1920s, 1930s, and 1940s.and 1940s.

1-1-1717

Modern Data Storage MediaModern Data Storage Media

♦ Middle to late 1930s saw the beginning of the Middle to late 1930s saw the beginning of the era of erasable magnetic storage media.era of erasable magnetic storage media.

♦ By late 1940s, early work was done on the use By late 1940s, early work was done on the use of magnetic tape for recording data.of magnetic tape for recording data.

♦ By 1950, several companies were developing By 1950, several companies were developing the magnetic tape concept for commercial use.the magnetic tape concept for commercial use.

1-1-1818

Modern Data Storage Media Modern Data Storage Media ♦ Magnetic Tape - commercially available units in 1952.Magnetic Tape - commercially available units in 1952.

♦ Direct Access Magnetic Devices - began to be Direct Access Magnetic Devices - began to be developed at MIT in the late 1930s and early 1940s.developed at MIT in the late 1930s and early 1940s.

♦ Magnetic Drum - early 1950s; forerunners of magnetic Magnetic Drum - early 1950s; forerunners of magnetic disk technology.disk technology.

♦ Magnetic Disk - commercially available in mid 1950s.Magnetic Disk - commercially available in mid 1950s.

♦ Compact Disk (CD) – introduced as a data storage Compact Disk (CD) – introduced as a data storage medium in 1985.medium in 1985.

♦ Solid-state technology – Flash drives.Solid-state technology – Flash drives.

1-1-1919

Using Data for Competitive Using Data for Competitive AdvantageAdvantage

♦ Data has become indispensable to every Data has become indispensable to every kind of modern business and government kind of modern business and government organization.organization.

♦ Data, the applications that process the Data, the applications that process the data, and the computers on which the data, and the computers on which the applications run are fundamental to every applications run are fundamental to every aspect of every kind of endeavor.aspect of every kind of endeavor.

1-1-2020

Using Data for Competitive Using Data for Competitive AdvantageAdvantage

♦ Data is a corporate resource, possibly the Data is a corporate resource, possibly the most important corporate resource.most important corporate resource.

♦ Data can give a company a crucial Data can give a company a crucial competitive advantage.competitive advantage.

♦ e.g., FedEx had a significant competitive e.g., FedEx had a significant competitive advantage when it first provided access to advantage when it first provided access to its package tracking data on its Web site.its package tracking data on its Web site.

1-1-2121

Problems in Storing and Problems in Storing and Accessing DataAccessing Data

♦ Difficult to store and to provide efficient, Difficult to store and to provide efficient, accurate access to a company’s data.accurate access to a company’s data.

♦ The volume of data that companies have The volume of data that companies have is massive.is massive.

♦ Wal-Mart estimates its data warehouse Wal-Mart estimates its data warehouse contains hundreds of terabytes (trillions of contains hundreds of terabytes (trillions of characters) of data.characters) of data.

1-1-2222

Problems in Storing and Problems in Storing and Accessing DataAccessing Data

♦ Larger number of people want access to Larger number of people want access to data:data:♠ EmployeesEmployees♠ CustomersCustomers♠ Trading partnersTrading partners

♦ Additional issues include: data security, Additional issues include: data security, data privacy, and backup and recovery.data privacy, and backup and recovery.

1-1-2323

Data SecurityData Security

♦ Involves a company protecting its data Involves a company protecting its data from theft, malicious destruction, from theft, malicious destruction, deliberate attempts at making phony deliberate attempts at making phony changes to the data.changes to the data.

♦ e.g., someone trying to increase his own e.g., someone trying to increase his own bank account balance.bank account balance.

1-1-2424

Data PrivacyData Privacy

♦ Ensuring that even employees who Ensuring that even employees who normally have access to the company’s normally have access to the company’s data are given access only to the specific data are given access only to the specific data that they need in their work.data that they need in their work.

1-1-2525

Backup and RecoveryBackup and Recovery

♦ The ability to reconstruct data if it is lost or The ability to reconstruct data if it is lost or corrupted.corrupted.

♦ e.g., following a hardware failuree.g., following a hardware failure

♦ e.g., following a natural disastere.g., following a natural disaster

1-1-2626

Data AccuracyData Accuracy

♦ The same data is stored several, The same data is stored several, sometimes many, times within a sometimes many, times within a company’s information system.company’s information system.

♦ When a new application is written, new When a new application is written, new data files are created to store its data.data files are created to store its data.

♦ Data can be duplicated within a single file Data can be duplicated within a single file and across files. and across files.

1-1-2727

Data as a Corporate ResourceData as a Corporate Resource

♦ Data may be the most difficult corporate Data may be the most difficult corporate resource to manage.resource to manage.

♦ We have tremendous volume, billions, We have tremendous volume, billions, trillions, and more individual pieces of trillions, and more individual pieces of data, each piece of which is different from data, each piece of which is different from the next.the next.

1-1-2828

Data as a Corporate ResourceData as a Corporate Resource

♦ A new kind of software is required to help A new kind of software is required to help manage the data.manage the data.

♦ Progressively faster hardware is required Progressively faster hardware is required to keep up with the increasing volume of to keep up with the increasing volume of data and data access demands.data and data access demands.

♦ Data management specialists need to be Data management specialists need to be developed and educated.developed and educated.

1-1-2929

The Database EnvironmentThe Database Environment

♦ Database Management System (DBMS)Database Management System (DBMS)

♦ New Personnel - database administrator New Personnel - database administrator and data management specialistand data management specialist

♦ Fast hardwareFast hardware

♦ Massive data storage facilitiesMassive data storage facilities

1-1-3030


♦ Encourages data sharingEncourages data sharing

♦ Helps control data redundancyHelps control data redundancy

♦ Has important improvements in data Has important improvements in data accuracyaccuracy

♦ Permits storage of vast volumes of data Permits storage of vast volumes of data with acceptable access.with acceptable access.

1-1-3131


♦ Allows database queriesAllows database queries

♦ Provides tools to control:Provides tools to control:♠ data securitydata security♠ data privacydata privacy♠ backup and recoverybackup and recovery

1-1-3232

“Copyright 2004 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein.”