Historical Perspectives

kushal-kumar
ch01.ppt

Chapter 1
Data: The New Corporate Resource

BLCN-534: Fundamentals of Database Systems

Chapter Objectives

  • Explain why humankind’s interest in data goes back to ancient times.
  • Describe how data needs have historically driven many information technology developments.
  • Describe the evolution of data storage media during the last century.
  • Relate the idea of data as a corporate resource that can be used to gain a competitive advantage to the development of the database management systems environment.

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Data

  • Data - the foundation of technological activity
  • Database - a highly organized collection of assembled data
  • Database Management System - sophisticated software that controls the database and the database environment

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What is Data?

  • A single piece of data is a single fact about something that interests us.
  • A fact can be any characteristic of an object.

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History of Data

  • People have been interested in data for at least the past 12,000 years.
  • Non-computer, primitive methods of data storage and handling.

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History of Data

  • Shepherds kept track of their flocks with pebbles.
  • A primitive but legitimate example of data storage and retrieval.

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History of Data

  • Dating back to 8500 B.C., unearthed clay tokens or “counters” may have been used for record keeping in primitive forms of accounting.
  • Tokens, with special markings on them, were sealed in hollow clay vessels that accompanied commercial goods in transit.

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Data Through the Ages

  • Record-keeping - the recording of data to keep track of how much a person has produced and what it can be bartered or sold for.
  • With time, different kinds of data were kept
  • calendars, census data, surveys, land ownership records, marriage records, records of church contributions, family trees, etc.

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History of Data

  • Double-entry bookkeeping - originated in the trading centers of fourteenth century Italy.
  • The earliest known example is from a merchant in Genoa and dates to the year 1340.

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Early Data Problems Spawn Calculating Devices

  • People interested in devices that could “automatically” process their data.
  • Blaise Pascal produced an adding machine that was an early version of today’s mechanical automobile odometers.

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Punched Cards - Data Storage

  • Invented in 1805 by Joseph Marie Jacquard of France.
  • Jacquard’s method of storing fabric patterns, a form of graphic data, as holes in punched cards was a very clever means of data storage.
  • Of great importance for computing devices to follow.

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Era of Modern Information Processing

  • The 1880 U.S. Census took about seven years to compile by hand.
  • Basing his work on Jacquard’s punched card concept, Herman Hollerith arranged to have the census data stored in punched cards and invented machinery to tabulate them.
  • In 1896 Hollerith formed the Tabulating Machine Company to produce and commercially market his devices -- this later became IBM.

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Era of Modern Information Processing

  • James Powers developed devices to automatically feed cards into the equipment and to automatically print results.
  • In 1911 he established the Powers Tabulating Machine Company -- this later became Unisys Corporation.

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The Mid-1950s

  • The introduction of electronic computers.
  • Witnessed a boom in economic development.
  • From this point onward, it would be virtually impossible to tie advances in computing devices to specific, landmark data storage and retrieval needs.

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Modern Data Storage Media

  • Punched paper tape - The earliest form of modern data storage, introduced in the 1870s and 1880s.
  • Punched cards were the only data storage medium used in the increasingly sophisticated electromechanical accounting machines of the 1920s, 1930s, and 1940s.

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Modern Data Storage Media

  • Middle to late 1930s saw the beginning of the era of erasable magnetic storage media.
  • By late 1940s, early work was done on the use of magnetic tape for recording data.
  • By 1950, several companies were developing the magnetic tape concept for commercial use.

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Modern Data Storage Media

  • Magnetic Tape - commercially available units in 1952.
  • Direct Access Magnetic Devices - began to be developed at MIT in the late 1930s and early 1940s.
  • Magnetic Drum - early 1950s; forerunners of magnetic disk technology.
  • Magnetic Disk - commercially available in mid 1950s.
  • Compact Disk (CD) – introduced as a data storage medium in 1985.
  • Solid-state technology – Flash drives.

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Using Data for Competitive Advantage

  • Data has become indispensable to every kind of modern business and government organization.
  • Data, the applications that process the data, and the computers on which the applications run are fundamental to every aspect of every kind of endeavor.

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Using Data for Competitive Advantage

  • Data is a corporate resource, possibly the most important corporate resource.
  • Data can give a company a crucial competitive advantage.

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

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Problems in Storing and Accessing Data

  • Difficult to store and to provide efficient, accurate access to a company’s data.
  • The volume of data that companies have is massive.
  • Wal-Mart estimates its data warehouse contains hundreds of terabytes (trillions of characters) of data.

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Problems in Storing and Accessing Data

  • Larger number of people want access to data:
  • Employees
  • Customers
  • Trading partner
  • Additional issues include: data security, data privacy, and backup and recovery.

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Data Security

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

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

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Data Privacy

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

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Backup and Recovery

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

  • e.g., following a hardware failure
  • e.g., following a natural disaster

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Data Accuracy

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

  • When a new application is written, new data files are created to store its data.
  • Data can be duplicated within a single file and across files.

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Data as a Corporate Resource

  • Data may be the most difficult corporate resource to manage.
  • We have tremendous volume, billions, trillions, and more individual pieces of data, each piece of which is different from the next.

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Data as a Corporate Resource

  • A new kind of software is required to help manage the data.
  • Progressively faster hardware is required to keep up with the increasing volume of data and data access demands.
  • Data management specialists need to be developed and educated.

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The Database Environment

  • Database Management System (DBMS)
  • New Personnel - database administrator and data management specialist
  • Fast hardware
  • Massive data storage facilities

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The Database Environment

  • Encourages data sharing
  • Helps control data redundancy
  • Has important improvements in data accuracy
  • Permits storage of vast volumes of data with acceptable access.

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The Database Environment

  • Allows database queries
  • Provides tools to control:
  • data security
  • data privacy
  • backup and recovery

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