数据库系统原理(英文)-6-11.ppt

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1、PartTwoDatabaseDesignChapter6DatabaseDesignandE-RModelPart1.DBdesignphases(§6.1)requirementanalysis,conceptualdesign,logicaldesign,physicaldesignPart2.TheEntity-RelationshipModelbasicE-Rmodelmodelingelements(§6.2.1-6.2.3):entitysets,relationshipsets,attri

2、butesconstraints(§6.3.1-6.3.3):mappingcardinality,keys,participationconstraint(§6.6)weakentitysetsFourPartsinChapter6April20113DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModelextendedE-Rmodel(§6.7)(§6.7.1-6.7.4)induceOOfeaturesintoE-Rmodel,thatis,spec

3、ialization,generalization,attributesinheritance,constraintsongeneralization(6.7.5)aggregation:relationshipamongrelationships(§6.4)entity-relationshipdiagrams(§6.8)E-Rdiagram,i.e.,conceptualdesign,forbankingenterpriseFourPartsinChapter6April20114DatabaseSystem

4、Concepts-Chapter6DatabaseDesignandE-RModelPart3.E-Rdesignissues(§6.5)whenapplyingE-Rmodeltomodeltheobjectsinrealworlds,someissues(considerationsandprinciples)shouldbeaddressed,toguaranteeDBSeffectivenessandefficiencyfordataPart4.Reductiontorelationalschemas(§

5、6.9)mappingelementsinE-Rmodeltothatinrelationalmodels,i.e.conceptualschemainitiallogicalschemaFourPartsinChapter6(cont.)April20115DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModelDatabasedesignconsistsoftwosequentialphasesanalyzingofuserrequirementswh

6、atdatashouldbestoredinthedatabasewhatoperations/transaction,suchasinsert,delete,updateandretrieveareneededtoconductedonthesedatadesigningofDBschemas,inaccordancewiththethree-levelofdataabstract(refertoFig.1.1)conceptualdesignlogicaldesign,atthelogicalleveland

7、viewlevelphysicaldesign,atthephysicallevelrefertoFig.1.0.1§6.1OverviewoftheDesignProcessApril20116DatabaseSystemConcepts-Chapter6DatabaseDesignandE-RModelSpecificationofuserrequirements(需求分析说明书)DBconceptualschema,i.e.E-Rdiagram(chapter6)DBlogicalschema,i.e.re

8、lationaldataschemaDBphysicalschema,e.g.physicalstoragestructureandaccessmethod(chapter11,12)initialrelationalschemagenerating(§6.9)relationalschemanormalizing(chapter7)Fig.6.0.1DBdesignph