GIT 335 Computer Systems Technology Lecture 8 Databases

GIT 335 Computer Systems Technology Lecture 8 Databases and Information Systems Dr. Thomas Schildgen, Professor Arizona State University Department of Technology Management GIT 335 Lecture 8 1

Lecture 8 Introduction to Information Technology Content taken from the Mc. Graw Hill Textbook Chapter 8 GIT 335 Lecture 8 2

Databases & Information Systems GIT 335 Lecture 8 3

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 GIT 335 Lecture 8 4

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 – - 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 GIT 335 Lecture 8 5

Managing Files: Basic Concepts This example shows a sample database in Microsoft Access. Products is a table. Product. ID is the primary key of the Product table. Product. ID is also a foreign key in the Orders table GIT 335 Lecture 8 6

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 GIT 335 Lecture 8 7

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. mp 3, . 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 GIT 335 Lecture 8 8

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 GIT 335 Lecture 8 9

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 GIT 335 Lecture 8 10

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 Did you know that 93% of • Integrity companies that lost their data • Security center for 10 days or more due • Availability to a disaster filed for bankruptcy • Reliability within a year? • Performance GIT 335 Lecture 8 11

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 GIT 335 Lecture 8 12

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 GIT 335 Lecture 8 13

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 GIT 335 Lecture 8 14

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 GIT 335 Lecture 8 15

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 Fast. Objects, Gem. Stone, Objectivity DB, Jasmine Object Database, and KE Texpress – Types include • Web database • Hypermedia database GIT 335 Lecture 8 16

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 GIT 335 Lecture 8 17

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 GIT 335 Lecture 8 18

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 GIT 335 Lecture 8 19

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 GIT 335 Lecture 8 20

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 GIT 335 Lecture 8 21

Databases & The Digital Economy • Innovative e-tailer technologies make online shopping easier – 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 GIT 335 Lecture 8 22

Databases & The Digital Economy • Types of E-Commerce – Business-to-business (B 2 B) • A business sells to other businesses using the internet or a private network to cut transaction costs and increase efficiencies – Business-to-consumer (B 2 C) • A business sells goods or services to consumers – Consumer-to-consumer (C 2 C) • Consumers sell goods or services directly to other consumers with the help of a third party, such as e. Bay. GIT 335 Lecture 8 23

Using Databases to Help Make Decisions • What are the qualities of good information? – – – Correct and verifiable Complete yet concise Cost effective Current Accessible GIT 335 Lecture 8 24

Using Databases to Help Make Decisions • Most organizations have 6 departments to which information must flow – – – Research and development Production (operations) Marketing and sales Accounting and finance Human resources (personnel) Information systems (IS) • Information flows horizontally between departments GIT 335 Lecture 8 25

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 GIT 335 Lecture 8 26

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 GIT 335 Lecture 8 27

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 GIT 335 Lecture 8 28

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 GIT 335 Lecture 8 29

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 GIT 335 Lecture 8 30

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 GIT 335 Lecture 8 31

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 GIT 335 Lecture 8 32

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 • Pattern recognition • Fuzzy logic • Virtual reality and simulation devices • Robotics GIT 335 Lecture 8 33

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 GIT 335 Lecture 8 34

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 GIT 335 Lecture 8 35

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 GIT 335 Lecture 8 36

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 GIT 335 Lecture 8 37

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 humanlike 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 GIT 335 Lecture 8 38

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? GIT 335 Lecture 8 39

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 GIT 335 Lecture 8 40