DATABASE TECHNOLOGIESLEARNING GOALSWhat is a database?Basic Concepts of Data ManagementBasic Concepts of Database systemsBasic Concepts in Data ManagementTraditional File SystemsTraditional File System AnomaliesDatabase Management System (DBMS)DBMS FunctionsMore DBMS FunctionsTypes of DBMSsTypes of DBMSs (Cont.)Slide 14Database ModelsFlat File DatabaseRelational ModelObject-Oriented DBMSData WarehouseData MartSummary Questions1DATABASETECHNOLOGIESBUS3500 - Abdou Illia, Fall 2012(September 5, 2012)2LEARNING GOALSExplain basic concepts of data management.Describe traditional file systems and identify their problems.Define database management systems and describe their various functions.Explain how the relational database model works.Explain Object-Oriented databases.Explain Data Warehouse, Data Mart3What is a database?Collection of related files containing records on people, places, or things.Databases make data easy to access and manage.Customers InfoAccounts Info Employees InfoAccess and Management tools4Basic Concepts of Data ManagementDatabase: Collection of data organized in different containersTable 1 Table 2 Table 3ReportForm 1Acc #:_______Name:_______5Basic Concepts of Database systemsTableTwo-dimensional structure composed of rows and columnsFieldLike a column in a spreadsheetField nameLike a column name in a spreadsheetExamples: AccountID, Customer, Type, BalanceField valuesActual data for the fieldRecordSet of fields that describe an entity (a person, an account, etc.)Primary key A field, or group of fields, that uniquely identifies a recordAccountID Customer Type Balance660001 John Smith Checking $120.00660002 Linda Martin Saving $9450.00660003 Paul Graham Checking $3400.00Accounts tableEach table has:FieldsRecords1 Primary key6Basic Concepts in Data ManagementA Primary key could be a single field like in these tablesA Primary key could be a composite key, i.e. multiple fieldsAccountID Customer Type Balance660001 John Smith Checking $120.00660002 Linda Martin Saving $9450.00660003 Paul Graham Checking $3400.00Primary key7Traditional File SystemsSystem of files that store groups of records used by a particular software applicationSimple but with a costInability to share dataInadequate securityDifficulties in maintenance and expansionAllows data duplication (e.g. redundancy)Application 1Program 1File 1File 2File 3Program 2File 1File 2File 3Application 2Program 1File 1File 2File 3Program 2File 1File 2File 38Traditional File System AnomaliesInsertion anomalyData needs to be entered more than once if located in multiple file systemsModification anomalyRedundant data in separate file systemsInconsistent data in your systemDeletion anomalyFailure to simultaneously delete all copies of redundant dataDeletion of critical data9Database Management System (DBMS)Combination of software and data forCollecting, storing and managing data in a database environment.A DBMS includes:DatabaseDatabase engine (for accessing and modifying the DB content)Data Manipulation LanguageApplication 1Program-1 Program-2Application 2Program-1 Program-2DBMS10DBMS FunctionsStore data (in tables) on secondary storageTransform data into information (reports, ..)Provide user with different logical views of actual database contentProvide securityDBMSs control who can add, view, change, or delete data in the databaseID Name Amt01 John 23.0002 Linda 3.0003 Paul 53.00Physical viewID Name02 LindaName Amt Paul 53.00ID Name Amt01 John 23.0002 Linda 3.00Logical views11More DBMS FunctionsAllow multi-user accessControl concurrency of access to dataPrevent one user from accessing data that has not been completely updatedWhen selling tickets online, Ticketmaster allows you to hold a ticket for only 2 minutes to make your purchase decision, then the ticket is released to sell to someone else – that is concurrency control12Types of DBMSsDesktopDesigned to run on desktop computersUsed by individuals or small businessesRequires little or no formal trainingDoes not have all the capabilities of larger DBMSsExamples: Microsoft Access, FileMaker, ParadoxDesktopServer / EnterpriseHandheld13Types of DBMSs (Cont.)Server / EnterpriseDesigned for managing larger and complex databases by large organizationsTypically operate in a client/server setupEither centralized or distributedCentralized – all data on one serverEasy to maintainProne to run slowly when many simultaneous usersNo access if the one server goes downDistributed – each location has part of the databaseVery complex database administrationUsually faster than centralizedIf one server crashes, others can still continue to operate.Examples: Oracle Enterprise, DB2, Microsoft SQL Server14Types of DBMSs (Cont.)HandheldDesigned to run on handheld devicesLess complex and have less capabilities than Desktop or Server DBMSsExample: Oracle Database Lite, IBM’s DB2 Everywhere.15Database ModelsDatabase model = a representation of the relationship between structures (e.g. tables) in a databaseCommon database modelsFlat file modelRelational model (this one is the most common)Object-oriented database model16Flat File DatabaseStores data in basic table structuresNo relationship between tablesUsed on PDAs for address book17Relational ModelMultiple tables related by common fieldsUses controlled redundancy to create fields that provide linkage relationships between tables in the databaseThese fields are called foreign keys – the secret to a relational databaseA foreign key is a field, or group of fields, in one table that is the primary key of another table18Object-Oriented DBMSNeeded for multimedia applications that manage images, voice, videos, graphics, etc. in addition to numbers and characters.Popular in Web applicationsSlower compared to relational DBMS for processing large number of transactionsHybrid object-relational DBMS are emerging19Data WarehouseMany organizations need internal, external, current, and historical dataData Warehouse are designed to, typically, store and manage data from operational transaction systems, Web site transactions.Figure 5-1220Data MartSubset of data warehouses that is highly focused and isolated
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