Managing Files: Basic Concepts

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Managing Files Basic Concepts

• A database is a logically organized collection of
  related data designed and built for a specific
  purpose
• Data is stored hierarchically for easier storage
  and retrieval
• Files collections of related records
• Records collections of related fields
• Field unit of data containing 1 or more
• characters
• Character a letter, number or special character
  made of bits
• Bit a 0 or 1

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Managing Files Basic Concepts

• Key Field the field that identifies a record
• Often an identifying number, such as social
  security number
• Primary keys must be unique
• Keys are used to pick records out of a database
• Unique keys make records stand out from each
  other
• If two records had the same key, then you might
  not pick the correct one
• Nonprimary keys are used to sort records in
  different ways
• Foreign keys are fields that appear in two
  different tables and are used to relate one table
  to another

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Managing Files Basic Concepts

• Program files are files containing software
  instructions
• Source program files are written by the software
  developer in the programming language
• Double-clicking on them wont run them
• They have file extensions like .cpp, .jav, .bas
• Executable files are program files translated so
  they can be executed on the computer
• Double-clicking on them will cause them to run
• They have file extensions like .exe or .com

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Managing Files Basic Concepts

• Data files are files that contain data such as
  words, numbers, pictures, or sounds
• These are the files that are used in databases
• They have extensions such as .txt .mdb, and .xls
• Graphics files have extensions like .tiff, .jpeg,
  and .png
• Audio files have extensions such as .mp3, .wav,
  and .mid
• Animation/video files have extensions such as
  .qt, .mpg, .avi, and .rm
• Data files are often compressed to save space and
  transmit them faster
• Compression removes repetitive elements from a
  file

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Database Management Systems

• Software written specifically to control the
  structure of a database and access to the data
• Reduced data redundancy
• Redundant data is stored in multiple places,
  which causes problems keeping all the copies
  current
• Improved data integrity
• Means the data is accurate, consistent, and up to
  date
• Increased security
• Limits who can create, read, update, and delete
  the data
• Ease of data maintenance
• Offer validation checks, backup utilities, and
  procedures for data inserting, updating, and
  deletion

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Database Management Systems3 Principal Components

• Data Dictionary
• A repository that stores the data definitions and
  descriptions of the structure of the data and the
  database
• DBMS Utilities
• Programs that allow you to maintain the database
  by creating, editing, deleting data, records, and
  files
• Also include automated backup and recovery
• Report Generator
• Program for producing an on-screen or printed
  document form all or part of a database

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Database Management SystemsDatabase Administrator

• Database Administrator (DBA)
• A high-paid, responsible position within an
  organization
• Coordinates all related activities and needs for
  an organizations database
• Ensures the databases
• Recoverability
• Integrity
• Security
• Availability
• Reliability
• Performance

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Database Models

• Hierarchical database
• Network database
• Relational database
• Object-oriented database
• Multidimensional database

• Fields or records are arranged in a family tree,
  with child records subordinate to parent or
  higher-level records
• Like a hierarchical database, but each child
  record can have more than one parent record
• Relates, or connects, data in different files
  through the use of a key, or common data element
• Uses objects (software written in small, reusable
  chunks) as elements within database files
• Models data as facts, dimensions, or numerical
  measures for use in the interactive analysis of
  large amounts of data

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Database Models

• Hierarchical Databases
• Fields or records are arranged in related groups
  resembling a family tree with child (low-level)
  records subordinate to parent (high-level)
  records
• Root record is the parent record at the top of
  the database, and data is accessed through the
  hierarchy
• Oldest and simplest used in mainframes

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Database Models

• Network Database
• Similar to a hierarchical database, but each
  child record can have more than one parent record
• Used principally with mainframe computers
• Requires the database structure to be defined in
  advance

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Database Models

• Relational Database
• Relates or connects data in different files
  through the use of a key, or common data element
• Examples are Oracle, Informix, Sybase
• Data exists independently of how it is physically
  stored
• Users dont need to know data structure to use
  the database
• Uses SQL (structured query language) to create,
  modify, maintain, and query the data
• Query by Example uses sample records or forms to
  allow users to define the qualifications for
  choosing records

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Database Models

• Object-oriented Databases
• Use objects, software written in small,
  manageable chunks, as elements within data files
• An object consists of
• Data in any form, including audio, graphics, and
  video
• Instructions on the action to be taken with the
  data
• Examples include FastObjects, GemStone,
  Objectivity DB, Jasmine Object Database, and KE
  Express
• Types include
• Web database
• Hypermedia database

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Database Models

• Multidimensional Database
• Models data as facts, dimensions, or numerical
  answers for use in the interactive analysis of
  large amounts of data for decision-making
  purposes
• Allows users to ask questions in colloquial
  English
• Use OLAP (Online Analytical Processing) software
  to provide answers to complex database queries

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Data Mining

• Is the computer-assisted process of sifting
  through and analyzing vast amounts of data to
  extract hidden patterns and meaning and to
  discover new knowledge
• Data is fed into a Data Warehouse through the
  following steps
• Identify and connect to data sources
• Perform data fusion and data cleansing
• Obtain both data and meta-data (data about the
  data)
• Transport data and meta-data to the Data
  Warehouse
• Data Warehouse is a special database that shows
  detailed and summary data from multiple sources

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Data Mining

• Methods for searching for patterns in the data
  and interpreting the results
• Regression analysis
• Develops a formula to fit patterns in the data
  that has been extracted
• Formula is applied to other data sets to predict
  future trends
• Classification analysis
• A statistical pattern recognition process that is
  applied to data sets with more than just
  numerical data

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Data Mining

• Applications include
• A phone company identifying customers with large
  bills, who were really small businesses trying to
  pay the cheaper residential rate
• A coach in the Gymnastics Federation used it to
  discover what long-term factors contributed to
  athletes performance
• Retail stores use it to predict future purchase
  patterns to help them choose which products to
  stock for the future

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Databases The Digital Economy

• E-Commerce
• The buying and selling of products and services
  through computer networks
• Examples of some e-tailers (electronic
  retailers)
• www.amazon.com sells books and music online
• www.sees.com sells candy online
• www.ebay.com connects buyers with sellers online
  using online auctions

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Databases The Digital Economy

• Innovative e-tailer technologies make online
  shopping easier
• One-click option
• Allows you to click on an item and immediately go
  to the check-out process
• 360-degree images
• Allow you to see all sides of an item
• Order tracking
• Bar codes are assigned to items being shipped
  that allow customers to check shipping progress
  via the internet
• Shop bots
• Are programs that help users search for a
  particular product of service

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Databases The Digital Economy

• Types of E-Commerce
• Business-to-business (B2B)
• A business sells to other businesses using the
  internet or a private network to cut transaction
  costs and increase efficiencies
• Business-to-consumer (B2C)
• A business sells goods or services to consumers
• Consumer-to-consumer (C2C)
• Consumers sell goods or services directly to
  other consumers with the help of a third party,
  such as eBay.

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Using Databases to Help Make Decisions

• What are the qualities of good information?
• Correct and verifiable
• Complete yet concise
• Cost effective
• Current
• Accessible

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Using Databases to Help Make Decisions

• Most organizations have 6 departments to which
  information must flow
• Research and development
• Production (or operations)
• Marketing and sales
• Accounting and finance
• Human resources (personnel)
• Information systems (IS)
• Information flows horizontally between departments

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Using Databases to Help Make Decisions

• Besides the 6 departments, many organizations
  also have 3 levels of management
• Strategic-level management
• Top managers concerned with strategic or
  long-term planning and decisions
• Tactical-level management
• Middle level managers who make decisions to
  implement the strategic goals set for the
  organization
• Operational-level management
• Low-level supervisors make daily operational
  decisions
• Information flows vertically between management
  levels

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Using Databases to Help Make Decisions

• Decentralized Organizations a new structure
• Employees increasingly telecommute some staff
  have no desk or office at work
• Employees communicate with each other more via
  email than in person
• Companies use Groupware CSCW (computer-supported
  cooperative work) systems to enable cooperative
  work by groups of people
• The management structure is flattened as
  employees are given more authority to make
  day-to-day decisions

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Using Databases to Help Make Decisions

• 6 computer-based information systems
• Office information systems
• Transaction processing systems
• Management information systems
• Decision support systems
• Executive support systems
• Expert systems

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Using Databases to Help Make Decisions

• Transaction Processing System (TPS)
• Transactions are recorded events of routine
  business activities such as bills, orders, and
  inventory
• TPS systems keep track of the transactions needed
  to conduct a business
• TPS systems are used by operational managers to
  track business activities
• Transactions database provides the basis for
  management information systems and decision
  support systems

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Using Databases to Help Make Decisions

• Management Information Systems (MIS)
• Computer-based information system that uses data
  recorded by a TPS as input to programs that
  produce routine reports as output
• Features
• Inputs are processed transaction data. Outputs
  are summarized structured reports
• Designed for tactical managers
• Draws from all departments
• Produces several kinds or reports summary,
  exception, periodic, and demand

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Using Databases to Help Make Decisions

• Decision Support Systems (DSS)
• Computer information system that provides a
  flexible tool for analysis and helps management
  focus on the future
• Features
• Inputs are external data and internal data such
  as summarized reports and processed transaction
  data. Outputs are demand reports
• Mainly for tactical managers
• Produces analytic models
• Developed to support the types of decisions faced
  by managers in specific industries

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Using Databases to Help Make Decisions

• Executive Support Systems
• An easy-to-use DSS made especially for strategic
  managers to support strategic decision-making
• Might allow executives to call up predefined
  reports
• Includes capability to browse through summarized
  information on all aspects of the organization
  and drill down for detailed data
• Allows executives to perform what-if scenarios

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The Ethics of Using Databases

• Identity Theft concerns
• A crime in which thieves hijack your identity and
  use your good credit rating to get cash, take out
  loans, order credit cards, and buy things in your
  name
• Privacy concerns
• Name migration getting endless junk mail and
  telemarketing calls
• Résumé rustling and online snooping
• Government prying and spying

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Artificial Intelligence

• Expert System
• One of the most useful applications of Artificial
  Intelligence (AI)
• AI is a group of related technologies used to
  develop software and machines that emulate human
  qualities such as learning, reasoning,
  communicating, seeing, and hearing
• Areas include
• Expert systems
• Natural language processing
• Intelligent agents
• Virtual reality and simulation devices
• Pattern recognition
• Fuzzy logic
• Robotics

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Artificial Intelligence

• Three components of an expert system
• Knowledge base
• An expert systems database of knowledge about a
  particular subject
• Inference engine
• The software that controls the search of the
  expert systems knowledge base and produces
  conclusions
• User interface
• The display screen the user used to interact with
  the expert system

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Artificial Intelligence

• Natural language processing
• Allows users to interact with a system using
  normal English
• The study of ways for computers to recognize and
  understand human language
• Intelligent agents
• A form of software with built-in intelligence
  that monitors work patterns, asks questions, and
  performs work tasks on your behalf
• Pattern recognition
• Involves a camera and software that identify
  recurring patterns in its vision and maps the
  pattern against patterns stored in a database

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Artificial Intelligence

• Fuzzy logic
• A method of dealing with imprecise data and
  uncertainty, with problems that have many answers
  rather than one
• Has been applied in running elevators to
  determine optimum times for elevators to wait
• Virtual reality
• A computer-generated artificial reality that
  projects a person into a sensation of 3-D space
• Often used with simulators to represent the
  behavior of physical or abstract systems

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Artificial Intelligence

• Robotics
• The development and study of machines that can
  perform work that is normally done by people
• Commonly found in manufacturing plants and also
  in situations where people would be in danger
• Nuclear plants
• Assembly lines, especially paint lines
• Checking for land mines
• Fighting oil-well fires

35
Artificial Intelligence

• Weak vs. Strong A.I.
• Weak A.I. claims computers can be programmed to
  simulate human cognition
• Strong A.I. claims that computers can think on a
  level that is equal to or better than humans, and
  can also achieve consciousness
• Cyc approach to strong A.I.
• A database in Austin, TX that holds 1.4 million
  basic truths
• Plan is that Cyc will automatically make
  human-like assumptions
• Hope is that Cyc will learn on its own
• Cog approach to strong A.I.
• MIT project that is a humanoid robot
• Tries to identify and search for patterns instead
  of following rules and facts

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Artificial Intelligence

• Test for Human Intelligence
• In 1950, Allen Turing predicted computers would
  be able to mimic human thinking
• The Turing test determines whether the machine is
  human
• Judge is in another location and doesnt see the
  computer
• If the computer can fool the judge, it is said to
  be intelligent
• Ethics in A.I.
• Prof. William Wallace from R.P.I. says that
  computer software is subtly shaped by the ethical
  judgments of its creators
• For example, H.M.O. software used by health
  insurers steers doctors to cheaper procedures
  but are they better?