Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Files and DatabasesIntroducing the DatabaseSlide 10Slide 11Slide 12Slide 13Database SystemsSlide 15DatabaseWhy DBMS?File Based SystemsFrom File Systems to DBMSDBMS BenefitsTerms and ConceptsDatabase EnvironmentDatabase ComponentsTypes of Database SystemsPC DatabasesCentralized DatabasesClient Server DatabasesDistributed DatabasesSlide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Historical RootsSlide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 5611File Systems and DatabasesChapter 1 The Worlds of Database SystemsProf. Sin-Min LeeDept. of Computer Science11Tuesday Thursday10:15 – 11:3011??!Your evaluation in this course is determined by:30% Class Presentation 10%Presentation report 5%111111A. Silberschatz, H.F. Korth, S. Sudarshan: Database System Concepts, 5th Ed., McGraw-Hill, 2006.11The mediocre teacher tells.The good teacher explains.The superior teacher demonstrates.The great teacher inspires.11Files and DatabasesFiles and DatabasesFile: A collection of records or documents dealing with one organization, person, area or subject (Rowley)Manual (paper) filesComputer filesDatabase: A collection of similar records with relationships between the records (Rowley)Bibliographic, statistical, business data, images, etc.11Introducing the DatabaseIntroducing the DatabaseMajor Database ConceptsData and informationData - Raw factsInformation - Processed dataData managementDatabaseMetadataDatabase management system (DBMS)111111Figure 1.1Sales per Employee for Each of ROBCOR’S Two Divisions1111Database SystemsDatabase SystemsTypes of Database SystemsNumber of UsersSingle-user–Desktop databaseMultiuser–Workgroup database–Enterprise databaseScopeDesktopWorkgroupEnterprise11Database SystemsDatabase SystemsTypes of Database SystemsLocationCentralizedDistributedUseTransactional (Production)Decision supportData warehouse11DatabaseDatabaseA Database is a collection of stored operational data used by the application systems of some particular enterprise (C.J. Date)Paper “Databases”Still contain a large portion of the world’s knowledgeFile-Based Data Processing SystemsEarly batch processing of (primarily) business dataDatabase Management Systems (DBMS)11Why DBMS?Why DBMS?History50’s and 60’s all applications were custom built for particular needsFile basedMany similar/duplicative applications dealing with collections of business dataEarly DBMS were extensions of programming languages1970 - E.F. Codd and the Relational Model1979 - Ashton-Tate and first Microcomputer DBMS11File Based SystemsFile Based SystemsNaughtyNiceJust what asked forCoalEstimationDeliveryListApplicationFileToysAddressesToys11From File Systems to DBMSFrom File Systems to DBMSProblems with file processing systemsInconsistent dataInflexibilityLimited data sharingPoor enforcement of standardsExcessive program maintenance11DBMS BenefitsDBMS BenefitsMinimal data redundancyConsistency of dataIntegration of dataSharing of dataEase of application developmentUniform security, privacy, and integrity controlsData accessibility and responsivenessData independenceReduced program maintenance11Terms and ConceptsTerms and ConceptsData independencePhysical representation and location of data and the use of that data are separatedThe application doesn’t need to know how or where the database has stored the data, but just how to ask for itMoving a database from one DBMS to another should not have a material effect on application programRecoding, adding fields, etc. in the database should not affect applications11Database EnvironmentDatabase EnvironmentCASE ToolsDBMSUserInterfaceApplicationProgramsRepositoryDatabase11Database ComponentsDatabase ComponentsDBMS===============Design toolsTable CreationForm CreationQuery CreationReport CreationProcedural language compiler (4GL)=============Run timeForm processorQuery processorReport WriterLanguage Run timeUserInterfaceApplicationsApplicationProgramsDatabaseDatabase contains:User’s DataMetadataIndexesApplication Metadata11Types of Database SystemsTypes of Database SystemsPC databasesCentralized databaseClient/server databasesDistributed databasesDatabase models11PC DatabasesPC DatabasesE.g.:AccessFoxProDbaseEtc.11Centralized DatabasesCentralized DatabasesCentral Computer11Client Server DatabasesClient Server DatabasesNetworkClientClientClientDatabaseServer11Distributed DatabasesDistributed DatabasescomputercomputercomputerLocation ALocation CLocation BHomogeneousDatabases11Distributed DatabasesDistributed DatabasesLocal NetworkDatabaseServerClientClientCommServerRemote Comp.Remote Comp.HeterogeneousOr FederatedDatabases11111111Introducing the DatabaseIntroducing the DatabaseImportance of DBMSIt helps make data management more efficient and effective.Its query language allows quick answers to ad hoc queries.It provides end users better access to more and better-managed data.It promotes an integrated view of organization’s operations -- “big picture.”It reduces the probability of inconsistent data.1111Figure 1.2The DBMS Manages the Interaction Between the End User and the Database1111Introducing the DatabaseIntroducing the DatabaseWhy Database Design Is Important?A well-designed database facilitates data management and becomes a valuable information generator.A poorly designed database is a breeding ground for uncontrolled data redundancies.A poorly designed database generates errors that lead to bad decisions.1111111111Historical RootsHistorical RootsWhy Study File Systems?It provides historical perspective.It teaches lessons to avoid pitfalls of data management.Its simple characteristics facilitate understanding of the design complexity of a database.It provides useful knowledge for converting a file system to a database system.11Figure 1.3Contents of the CUSTOMER File111111Table 1.1 Basic File TerminologyData“Raw” facts that have little meaning unless they have beenorganized in some logical manner. The smallest piece of datathat can be “recognized” by the computer is a singlecharacter, such as the letter A, the number 5, or
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