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Information Resources Information Resources ManagementManagement
January 16, 2001January 16, 2001
AgendaAgenda
AdministriviaAdministrivia Course OverviewCourse Overview Database Management Systems Database Management Systems
(DBMSs)(DBMSs) Homework #1Homework #1
AdministriviaAdministrivia
SyllabusSyllabus BookBook HomeworkHomework Web PageWeb Page
Course CalendarCourse Calendar
Eleven HomeworksEleven Homeworks Approximately one per weekApproximately one per week
ExamsExams Midterm 1 - 2/20Midterm 1 - 2/20 Midterm 2 - 3/20Midterm 2 - 3/20 Final - TBAFinal - TBA
QuizzesQuizzes Up to fiveUp to five
Overview – PerspectiveOverview – Perspective
Database Design and ImplementationDatabase Design and Implementation ““Business” PerspectiveBusiness” Perspective IT professional in an organizationIT professional in an organization
Database DesignDatabase Design
Relational ModelRelational Model Database ModelingDatabase Modeling Evaluation ToolsEvaluation Tools NormalizationNormalization
Database Database ImplementationImplementation SQL (Structured Query Language)SQL (Structured Query Language) Dependability, ReliabilityDependability, Reliability ArchitectureArchitecture Distributed DatabasesDistributed Databases
Database Management Database Management SystemsSystems Traditional File Processing SystemsTraditional File Processing Systems DatabaseDatabase ComparisonComparison Database LifecyclesDatabase Lifecycles Database Management System Database Management System
FunctionsFunctions
Traditional File Traditional File Processing SystemProcessing System Separate FilesSeparate Files
DepartmentDepartment Business FunctionBusiness Function
Independent of Each OtherIndependent of Each Other High Level of Program DependenceHigh Level of Program Dependence
Program contains file structure and Program contains file structure and locationlocation
ExampleExampleTime Cards
Data Entry
Trans
Trans Master
New Master
Checks
Report
Sort by Employe
e #
Sorted by
Employee #
Update Master
Data Abstraction Data Abstraction (Views)(Views) Physical/InternalPhysical/Internal
Logical/ConceptualLogical/Conceptual
View/ExternalView/External
How data is storedHow data is stored
What is storedWhat is stored
What is used What is used (subset)(subset)
Traditional file processing prevents this abstraction. Why?
Three Views of DataThree Views of Data
External (View)
Client Customer
Programmer
Conceptual (Logical)
Designer
Database Administrat
or (DBA)
Internal (Physical)
Database Administrat
or (DBA)
Tech Support
What is NeededWhat is Needed
Physical IndependencePhysical Independence Logical IndependenceLogical Independence
Physical IndependencePhysical Independence
Physical layout and organization of data can be Physical layout and organization of data can be changed without changing either the overall changed without changing either the overall logical structure of the data or the application logical structure of the data or the application programsprograms
ExamplesExamples Move data locationMove data location Move data to faster storageMove data to faster storage Change indexingChange indexing Add a secondary keyAdd a secondary key
Physical IndependencePhysical Independence
External (View)
Conceptual (Logical)
Internal (Physical)
No Resulting Change Here
Change Here
Logical IndependenceLogical Independence
Non-loss changes to the logical structure can Non-loss changes to the logical structure can be made without changing application be made without changing application programs or end-user viewsprograms or end-user views
ExamplesExamples Change format of a field (zip from 5 to 9)Change format of a field (zip from 5 to 9) Add a new data fieldAdd a new data field Add a new tableAdd a new table Divide a table into twoDivide a table into two
Logical IndependenceLogical Independence
External (View)
Conceptual (Logical)
Internal (Physical)
No Resulting Change Here
Change Here Coordinating Change Here
DatabaseDatabase
organized collection of logically related dataorganized collection of logically related data shared collection of interrelated data shared collection of interrelated data
designed to meet the informational needs of designed to meet the informational needs of multiple usersmultiple users
data is independent of program and user data is independent of program and user viewsviews
data is stored with physical and logical data is stored with physical and logical independenceindependence
Database Management Database Management System (DBMS)System (DBMS) Software that facilitates the Software that facilitates the
implementation of the database conceptimplementation of the database concept
ComparisonComparison(Traditional vs. (Traditional vs. Database)Database)
Database Advantages/Traditional Database Advantages/Traditional DisadvantagesDisadvantages program-data dependenceprogram-data dependence duplicationduplication data sharingdata sharing development timesdevelopment times program maintenance – ripple effectsprogram maintenance – ripple effects flexibilityflexibility
ComparisonComparison(Traditional vs. (Traditional vs. Database)Database) Database Advantages/Traditional Database Advantages/Traditional
DisadvantagesDisadvantages securitysecurity data integritydata integrity data as corporate resourcedata as corporate resource
ComparisonComparison(Traditional vs. (Traditional vs. Database)Database) Traditional Advantages/Database Traditional Advantages/Database
DisadvantagesDisadvantages sizesize complexitycomplexity costcost special hardwarespecial hardware impact of failureimpact of failure recoveryrecovery
ComparisonComparison(Traditional vs. (Traditional vs. Database)Database) Traditional Advantages/Database Traditional Advantages/Database
DisadvantagesDisadvantages additional personneladditional personnel conversion costsconversion costs organizational conflictorganizational conflict
Database LifecycleDatabase Lifecycle
1. Enterprise Modeling1. Enterprise Modeling
2. Conceptual Data Modeling2. Conceptual Data Modeling
3. Logical Database Design3. Logical Database Design
4. Physical Database Design and 4. Physical Database Design and CreationCreation
5. Database Implementation5. Database Implementation
6. Database Maintenance6. Database Maintenance
People InvolvedPeople Involved
Systems analysts & designersSystems analysts & designers Database analysts & designersDatabase analysts & designers UsersUsers ProgrammersProgrammers Database Administrators (DBAs)Database Administrators (DBAs) Networking expertsNetworking experts Other technical expertsOther technical experts
Database Management Database Management System FunctionsSystem Functions data storage, retrieval and updatedata storage, retrieval and update user-accessible cataloguser-accessible catalog transaction supporttransaction support concurrency controlconcurrency control recovery servicesrecovery services authorization servicesauthorization services support for data communicationsupport for data communication
Database Management Database Management System FunctionsSystem Functions integrity servicesintegrity services
types - character, number, etc.types - character, number, etc. internal validityinternal validity
services to promote data independence services to promote data independence (logical and physical)(logical and physical)
utility servicesutility services
Database ApplicationsDatabase Applications
PersonalPersonal one userone user
WorkgroupWorkgroup small team - LAN connectedsmall team - LAN connected
Department/DivisionDepartment/Division multiple teams and functionsmultiple teams and functions
EnterpriseEnterprise entire organizationentire organization
In-Class ExerciseIn-Class Exercise
Groups of 4Groups of 4 Introduce yourself Introduce yourself Identify a possible database of each Identify a possible database of each
typetype Pick a speakerPick a speaker
In-Class ExerciseIn-Class Exercise
Introduce yourself and group membersIntroduce yourself and group members Give group’s example databasesGive group’s example databases
personalpersonal workgroupworkgroup department/divisiondepartment/division enterpriseenterprise
Personal DatabasesPersonal Databases
BenefitsBenefits individualizedindividualized meet specific meet specific
needsneeds purchased purchased
packagepackage
DrawbacksDrawbacks limited to no data limited to no data
sharingsharing replicated datareplicated data consolidation - consolidation -
standardizationstandardization supportsupport
Workgroup DatabasesWorkgroup Databases
BenefitsBenefits meet specific meet specific
needsneeds data shared data shared
(across group)(across group) customized customized
“views”“views”
DrawbacksDrawbacks data sharing data sharing
across groupsacross groups replicated datareplicated data securitysecurity not optimal for not optimal for
individualindividual DBMS cost & DBMS cost &
supportsupport
Department DatabasesDepartment Databases
BenefitsBenefits meet (specific) meet (specific)
needsneeds data shareddata shared
DrawbacksDrawbacks data sharingdata sharing replicated datareplicated data securitysecurity not optimal for not optimal for
individual/groupindividual/group performanceperformance DBMS cost & DBMS cost &
developmentdevelopment
Enterprise DatabasesEnterprise Databases
BenefitsBenefits meet needsmeet needs data shareddata shared ““mineable”mineable” consistent view to consistent view to
customerscustomers
DrawbacksDrawbacks size & complexitysize & complexity securitysecurity cost & supportcost & support developmentdevelopment standards & standards &
bureaucracybureaucracy distribution & distribution &
ownershipownership
Best Database?Best Database?
Personal?Personal? Workgroup?Workgroup? Department?Department? Enterprise?Enterprise?
Best Database?Best Database?
Personal?Personal? Workgroup?Workgroup? Department?Department? Enterprise?Enterprise?
Combination of databases that meets the Combination of databases that meets the needs of individuals, teams, needs of individuals, teams,
departments, and the companydepartments, and the company
Best Database?Best Database?
To the individual, it’s a personal To the individual, it’s a personal databasedatabase
To the team, it’s a workgroup databaseTo the team, it’s a workgroup database To the department, it’s a department To the department, it’s a department
databasedatabase To the CEO, it’s an enterprise databaseTo the CEO, it’s an enterprise database (To the DBA, it’s a headache)(To the DBA, it’s a headache)
Homework #1Homework #1
Data management recommendationData management recommendation High-level, experience basedHigh-level, experience based
““glossy” vendor materialglossy” vendor material ShowShow
alternativesalternatives strengths/weaknesses of eachstrengths/weaknesses of each well-reasoned explanationwell-reasoned explanation