数据库系统原理(英文)-6-09.pptVIP免费

PartTwoDatabaseDesignChapter6DatabaseDesignandE-RModelMarch2009DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModel3Part1.DBdesignphases(§6.1)requirementanalysis,conceptualdesign,logicaldesign,physicaldesignPart2.TheEntity-RelationshipModelbasicE-Rmodelmodelingelements(§6.2.1-6.2.3):entitysets,relationshipsets,attributesconstraints(§6.3.1-6.3.3):mappingcardinality,keys,participationconstraint(§6.6)weakentitysetsFourPartsinChapter6March2009DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModel4extendedE-Rmodel(§6.7)(§6.7.1-6.7.4)induceOOfeaturesintoE-Rmodel,thatis,specialization,generalization,attributesinheritance,constraintsongeneralization(6.7.5)aggregation:relationshipamongrelationships(§6.4)entity-relationshipdiagrams(§6.8)E-Rdiagram,i.e.,conceptualdesign,forbankingenterpriseFourPartsinChapter6March2009DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModel5Part3.E-Rdesignissues(§6.5)whenapplyingE-Rmodeltomodeltheobjectsinrealworlds,someissues(considerationsandprinciples)shouldbeaddressed,toguaranteeDBSeffectivenessandefficiencyfordataPart4.Reductiontorelationalschemas(§6.9)mappingelementsinE-Rmodeltothatinrelationalmodels,i.e.conceptualschemainitiallogicalschemaFourPartsinChapter6(cont.)March2009DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModel6Databasedesignconsistsoftwosequentialphasesanalyzingofuserrequirementswhatdatashouldbestoredinthedatabasewhatoperations/transaction,suchasinsert,delete,updateandretrieveareneededtoconductedonthesedatadesigningofDBschemas,inaccordancewiththethree-levelofdataabstract(refertoFig.1.1)conceptualdesignlogicaldesign,atthelogicallevelandviewlevelphysicaldesign,atthephysicallevelrefertoFig.1.0.1§6.1OverviewoftheDesignProcessSpecificationofuserrequirements(需求分析说明书)DBconceptualschema,i.e.E-Rdiagram(chapter6)DBlogicalschema,i.e.relationaldataschemaDBphysicalschema,e.g.physicalstoragestructureandaccessmethod(chapter11,12)initialrelationalschemagene...