Using Information Technology Chapter 8 Files, Databases, & E-Commerce

2 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Files, Databases, & E-Commerce Digital Engines for the New Economy 8.1Managing Files: Basic Concepts 8.2Database Management Systems 8.3Database Models 8.4 Features of a Database Management System 8.5Databases & the New Economy: E-Commerce, Data Mining, & B2B Systems 8.6 The Ethics of Using Databases: Concerns about Accuracy & Privacy

Files, Databases, & E-Commerce 3 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.1 Managing Files: Basic Concepts Data storage hierarchy - levels of data stored in a computer: Bits Character (bytes) Fields Records Files

Files, Databases, & E-Commerce 4 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Key Field A key field uniquely identifies a record for processing and retrieval The primary characteristic of the key field is that it is unique

Files, Databases, & E-Commerce 5 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Types of Files Program files - contain computer instructions Source program files Executable files Data files - files that contain data (words, numbers, pictures, sounds, etc.)

Files, Databases, & E-Commerce 6 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Other Common Types of Files ASCII Image (graphic) Audio Animation/video Web Desktop publishing Drivers Windows operating systems

Files, Databases, & E-Commerce 7 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Two Types of Data Files Master file - a data file containing relatively permanent records that are generally updated periodically Transaction file - a temporary holding file that holds all changes to be made to the master file: additions, deletions, and revisions

Files, Databases, & E-Commerce 8 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Data Access Methods Sequential storage - data is stored and retrieved in sequence Direct access storage - the computer can go directly to the information desired

Files, Databases, & E-Commerce 9 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Offline versus Online Storage Offline storage - data is not directly accessible for processing until the tape or disk its on has been loaded onto an input device Online storage - stored data is randomly (directly) accessible for processing

Files, Databases, & E-Commerce 10 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.2 Database Management Systems Database management system (DBMS) - programs that control the structure of a database and access to the data Types of database access: Individual databases Multiuser databases

Files, Databases, & E-Commerce 11 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Advantages of DBMS Reduced data redundancy Improved data integrity Increased security Ease of data maintenance

Files, Databases, & E-Commerce 12 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.3 Database Models Hierarchical database - fields or records are arranged in related groups, resembling a family tree, with child (lower- level) records subordinate to parent (higher-level) records Example of cruise ship reservation system

Files, Databases, & E-Commerce 13 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Database Models Network database - similar to a hierarchical database, but each child record can have more than one parent record Example of college class-scheduling system

Files, Databases, & E-Commerce 14 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Database Models Relational database - relates (connects) data in different files through the use of a key field, or common data element Example of state department of motor vehicles database

Files, Databases, & E-Commerce 15 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Database Models Object-oriented database - uses objects--software written in small, reusable chunks--as elements within database files An object consists of: Data in any form, and Instructions on the actions to take on the data

Files, Databases, & E-Commerce 16 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.4 Features of a Database Management System A database management system includes the following components: Data Dictionary - procedures document or disk file that stores the data definitions and descriptions of the structure of data used in the database DBMS Utilities are programs that allow you to maintain the database Report Generator is a program for producing an on- screen or printed document from all or part of a database.

Files, Databases, & E-Commerce 17 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Database Management System Components A database management system includes the following components (continued): Access Security - a feature allowing database administrators to specify different access privileges for different users of a DBMS System Recovery - enable the database administrator to recover contents of the database in the event of a hardware or software failure

Files, Databases, & E-Commerce 18 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.5 Databases & the New Economy: E- Commerce, Data Mining, & B2B Systems E-commerce (electronic commerce) - the buying and selling of products and services through computer networks No limits on the uses of e-commerce

Files, Databases, & E-Commerce 19 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Data Mining Data miningData mining (DM) - the computer-assisted process of sifting through and analyzing vast amounts of data in order to extract meaning and discover new knowledge Data mining process consists of: Data acquisition Data cleansing Meta-data generation Data transport to data warehouse Searching for patterns Interpreting results

Files, Databases, & E-Commerce 20 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Business-to-Business (B2B) Systems B2B - a system in which a business sells to other businesses, using the Internet or a private network to cut transaction costs and increase efficiencies

Files, Databases, & E-Commerce 21 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. 8.6 Ethics of Using Databases: Concerns about Accuracy & Privacy Morphing - process in which a film or video is displayed on a computer screen and altered pixel by pixel, or dot by dot, into something else

Files, Databases, & E-Commerce 22 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. The Ethics of Using Databases Manipulation of sound can be used:sound Positively as in the music industry Negatively for misrepresentation

Files, Databases, & E-Commerce 23 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. The Ethics of Using Databases Manipulation of video & television Manipulation of photos

Files, Databases, & E-Commerce 24 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. The Ethics of Using Databases Privacy - the right of people not to reveal information about themselves

Files, Databases, & E-Commerce 25 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. The Ethics of Using Databases Accuracy and completeness – can be issue when searching for historical data Monopolizing information – by an individual or organization could lead to access related issues

Files, Databases, & E-Commerce 26 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. The Ethics of Using Databases Online privacy can be invaded by: Name migration Identity theft Resume rustling and online snooping Government prying and spying

Files, Databases, & E-Commerce 27 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the term for a logically organized collection of related data? Database

Files, Databases, & E-Commerce 28 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What term refers to the levels of data stored in a computer database? Data storage hierarchy

Files, Databases, & E-Commerce 29 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What type of storage allows the computer to go directly to the information you want? Direct access storage

Files, Databases, & E-Commerce 30 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the smallest unit of data that a computer can save? Bit

Files, Databases, & E-Commerce 31 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the term for field chosen to uniquely identify a record? Key field

Files, Databases, & E-Commerce 32 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What type of database is stored on different computers in different locations connected by a peer-to-peer network? Distributed database

Files, Databases, & E-Commerce 33 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What model of database has fields or records arranged in related groups resembling a family tree, with child (lower-level) records subordinate to parent (higher- level) records? Hierarchical database

Files, Databases, & E-Commerce 34 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What files contain software instructions? Program files

Files, Databases, & E-Commerce 35 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What files contain relatively permanent records? Master files

Files, Databases, & E-Commerce 36 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the term for the temporary holding file that holds all changes to be made to the master file? Transaction file

Files, Databases, & E-Commerce 37 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the process whereby a film or video image is displayed on a computer screen and altered pixel by pixel, or dot by dot, until the image metamorphoses into something else? Morphing

Files, Databases, & E-Commerce 38 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check Which model of database connects data in different files through the use of a key field? Relational database

Files, Databases, & E-Commerce 39 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What are the levels of data in the data storage hierarchy, from smallest to largest? Bits, bytes (characters), fields, records, files, databases

Files, Databases, & E-Commerce 40 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the name for the three characters appearing after a period at the end of a filename? Extension

Files, Databases, & E-Commerce 41 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the term for the software written to control the structure of a database and access to the data? Database management system (DBMS) or database manager

Files, Databases, & E-Commerce 42 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What storage means that data is stored and retrieved in sequence? Sequential storage

Files, Databases, & E-Commerce 43 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What kind of databases are collections of files used by one user? Individual or single-user databases

Files, Databases, & E-Commerce 44 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What is the term for a system in which a business sells to other businesses using the Internet or a private network to cut transaction costs and increase efficiencies? B2B (Business-to-business) system

Files, Databases, & E-Commerce 45 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What kind of file contains high-level computer instructions in the original form written by the programmer? Source program file

Files, Databases, & E-Commerce 46 Copyright © Exclusive rights by The McGraw-Hill Companies, Inc. Concept Check What model of database is similar to a hierarchical database, but each child record can have more than one parent record? Network database