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Chapter Eight Database Applications and Implications Chapter Outline • The Electronic File Cabinet: Database Basics • Beyond the Basics: Database Management Systems • No Secrets: Computers and Privacy ©1999 Addison Wesley Longman 8.2 The Electronic File Cabinet: Database Basics Like word processors, spreadsheets, and graphics programs, database programs are applications which turn programs into productive tools. ©1999 Addison Wesley Longman 8.3 The Electronic File Cabinet: Database Basics Database programs are designed to maintain collections of information stored on computer disks. – What Good Is a Database? – Database Anatomy – Database Operations – Special-Purpose Databases ©1999 Addison Wesley Longman 8.4 What Good Is a Database? A database is a collection of information stored in an organized form in a computer. ©1999 Addison Wesley Longman 8.5 What Good Is a Database? Computerized databases offer several advantages such as: – Make it easier to store large quantities of information. – Make it easier retrieve information quickly and flexibly. – Organize and reorganize information. – Print and distribute information in a variety of ways. ©1999 Addison Wesley Longman 8.6 Database Anatomy A database is a collection of one or more database files records. A file is a collection of related information (records). ©1999 Addison Wesley Longman 8.7 Database Anatomy A record is the information relating to one person, product, or event. A field a discrete chunk of information in a record. ©1999 Addison Wesley Longman 8.8 Database Anatomy • The view is a display of the information in fields based on a particular layout of field data. ©1999 Addison Wesley Longman 8.9 Database Operations Database commands are used to retrieve, organize, print and distribute database information. – Import: receive data in the form of text files. – Browse: navigate through information by just looking at it. ©1999 Addison Wesley Longman 8.10 Database Operations – Query: search or select one or more specific records. – Sort: rearrange records (alphabetically or numerically). – Report: printout of an ordered list of records. ©1999 Addison Wesley Longman 8.11 Special-Purpose Database Programs Specialized database software is preprogrammed for specific data storage and retrieval purposes. ©1999 Addison Wesley Longman 8.12 Special-Purpose Database Programs Geographical information systems (GISs): include geographic and demographic data in map form. ©1999 Addison Wesley Longman 8.13 Special-Purpose Database Programs • Personal information managers (PIMs): an electronic organizer that is customized to fit individual needs. ©1999 Addison Wesley Longman 8.14 Beyond the Basics: Database Management Systems A file manager is a program that allows users to work with one file at a time. ©1999 Addison Wesley Longman 8.15 Beyond the Basics: Database Management Systems Database Management Systems (DBMSs) – is a program or system of programs that can manipulate data in a large collection of files – different users see different points of view – may be interactive ©1999 Addison Wesley Longman 8.16 Database ©1999 Addison Wesley Longman 8.17 Database Management System ©1999 Addison Wesley Longman 8.18 data base management system • a three level framework – internal level • store the elemental pieces of data – conceptual level • fields and records – external level • a user dependent view ©1999 Addison Wesley Longman 8.19 data base management system(II) • DBMS is a set of programs used to – define and establish the database – interface with the user – process the transactions – control the contents – perform administrative functions ©1999 Addison Wesley Longman 8.20 data independency • user interface are immune to the change in storage and data access methods ©1999 Addison Wesley Longman 8.21 options for the data models • hierarchical model • network model • relational model ©1999 Addison Wesley Longman 8.22 hierarchical model • tree structure • efficient for particular queries • lack of flexibility ©1999 Addison Wesley Longman 8.23 Hierarchical Model ©1999 Addison Wesley Longman 8.24 network model • emphasize on the links between records • flexible • complex ©1999 Addison Wesley Longman 8.25 Network Model ©1999 Addison Wesley Longman 8.26 relational model • each item is treated as an entry in the relation table • simple and easy ©1999 Addison Wesley Longman 8.27 What Makes a Database Relational? • Relational model - a mathematical model that combines data in tables. ©1999 Addison Wesley Longman 8.28 centralized systems • all records and files and all user interfaces are controlled by one group • advantages – consistency – data independent – easy to retrieve ©1999 Addison Wesley Longman 8.29 distributed systems • highly responsive to differences in data gathering, storage and access ©1999 Addison Wesley Longman 8.30 security and privacy • security---protecting against unauthorized disclosure, modification or destruction • privacy--- individual’s right to share or not to share information with others ©1999 Addison Wesley Longman 8.31 Attack and defense • attack strategies – Trojan Horses, viruses, ... • defense strategies – firewalls, making backups, encipher the data, ... • highly sensitive data should not be stored in resource sharing systems ©1999 Addison Wesley Longman 8.32 access control and constraints • access to database---password • access to specific data---second password • deny access to specific data • update process allowed only by a designated person from a specific terminal during certain time • using medium such as magnetic card ©1999 Addison Wesley Longman 8.33 logging • log records contain – – – – – – each access or update request user’s name terminal time sensitive of information sought granted or not • analysis and surveillance programs may be used to protect the database. ©1999 Addison Wesley Longman 8.34 No Secrets: Computers and Privacy Big Brother and Big Business Telemarketers ©1999 Addison Wesley Longman 8.35 The Privacy Problem More than 15,000 specialized marketing databases contain 2 billion names. These databases contain characteristics like age, income, religion, and even personal preference. ©1999 Addison Wesley Longman 8.36 Big Brother and Big Business • Government uses record matching to locate criminals ranging from tax evaders to mass murderers. • Credit bureaus collect information about us and allows us to use credit cards. ©1999 Addison Wesley Longman 8.37 Big Brother and Big Business • With the increased amount of information available, problems that arise include: – Data errors are common – Data can become nearly immortal – Data isn’t secure ©1999 Addison Wesley Longman 8.38 Privacy • the US government has no right to put together all the personal information in the computerized data bank. • The Privacy Act---(Dec. 31, 1974) – the individuals have the right to access and if necessary change or update information about themselves in all but a very few federal data banks ©1999 Addison Wesley Longman 8.39