Chapter Eight Database Applications and Implications

©1999 Addison Wesley Longman8.2 Chapter Outline The Electronic File Cabinet: Database Basics Beyond the Basics: Database Management Systems No Secrets: Computers and Privacy

©1999 Addison Wesley Longman8.3 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 Longman8.4 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 Longman8.5 What Good Is a Database? A database is a collection of information stored in an organized form in a computer.

©1999 Addison Wesley Longman8.6 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 Longman8.7 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 Longman8.8 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 Longman8.9 Database Anatomy The view is a display of the information in fields based on a particular layout of field data.

©1999 Addison Wesley Longman8.10 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 Longman8.11 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 Longman8.12 Special-Purpose Database Programs Specialized database software is preprogrammed for specific data storage and retrieval purposes.

©1999 Addison Wesley Longman8.13 Special-Purpose Database Programs Geographical information systems (GISs): include geographic and demographic data in map form.

©1999 Addison Wesley Longman8.14 Special-Purpose Database Programs Personal information managers (PIMs): an electronic organizer that is customized to fit individual needs.

©1999 Addison Wesley Longman8.15 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 Longman8.16 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 Longman8.17 Database

©1999 Addison Wesley Longman8.18 Database Management System

©1999 Addison Wesley Longman8.19 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 Longman8.20 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 Longman8.21 data independency user interface are immune to the change in storage and data access methods

©1999 Addison Wesley Longman8.22 options for the data models hierarchical model network model relational model

©1999 Addison Wesley Longman8.23 hierarchical model tree structure efficient for particular queries lack of flexibility

©1999 Addison Wesley Longman8.24 Hierarchical Model

©1999 Addison Wesley Longman8.25 network model emphasize on the links between records flexible complex

©1999 Addison Wesley Longman8.26 Network Model

©1999 Addison Wesley Longman8.27 relational model each item is treated as an entry in the relation table simple and easy

©1999 Addison Wesley Longman8.28 What Makes a Database Relational? Relational model - a mathematical model that combines data in tables.

©1999 Addison Wesley Longman8.29 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 Longman8.30 distributed systems highly responsive to differences in data gathering, storage and access

©1999 Addison Wesley Longman8.31 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 Longman8.32 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 Longman8.33 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 Longman8.34 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 Longman8.35 No Secrets: Computers and Privacy Telemarketers Big Brother and Big Business

©1999 Addison Wesley Longman8.36 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 Longman8.37 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 Longman8.38 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 Longman8.39 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