Managing Database and company files

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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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• 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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• 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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• 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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http://www.amazon.com/

http://www.sees.com/

http://www.ebay.com/

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


• 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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• 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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• 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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• 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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• 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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• 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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• 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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• 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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Managing Database and company files

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