managing database and company files - globaledulink.co.uk · programming language...
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Managing Database and company files
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 won’t 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 Systems 3 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 Systems Database Administrator
• Database Administrator (DBA)
• A high-paid, responsible position within an organization
• Coordinates all related activities and needs for an organization’s database
• Ensures the database’s
• 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
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
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 don’t 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
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 system’s database of knowledge about a particular subject
• Inference engine • The software that controls the search of the expert system’s 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
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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 doesn’t 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?
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