2023年全國碩士研究生考試考研英語一試題真題（含答案詳解+作文范文）_第1頁
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1、大連交通大學(xué)2011屆本科生畢業(yè)設(shè)計(jì)（論文）外文翻譯1SQLServerStedProceduresMicrosoftSQLServerprovidesthestedproceduremechanismtosimplifythedatabasedevelopmentprocessbygroupingTransactSQLstatementsintomanageableblocks.BenefitsofStedProceduresWhys

2、houldyouusestedproceduresLetstakealookatthekeybenefitsofthistechnology:?Precompiledexecution.SQLServercompileseachstedprocedureoncethenreutilizestheexecutionplan.Thisresultsintremendousperf?manceboostswhenstedproceduresa

3、recalledrepeatedly.?Reducedclientservertraffic.IfwkbwidthisaconcerninyourenvironmentyoullbehappytolearnthatstedprocedurescanreducelongSQLqueriestoasinglelinethatistransmittedoverthewire.?Efficientreuseofcodeprogrammingab

4、straction.Stedprocedurescanbeusedbymultipleusersclientprograms.Ifyouutilizetheminaplannedmanneryoullfindthedevelopmentcycletakeslesstime.?Enhancedsecuritycontrols.Youcangrantuserspermissiontoexecuteastedprocedureindepend

5、entlyofunderlyingtablepermissions.Stedproceduresareverysimilartouserdefinedfunctionsbuttherearesubtledifferences.StructureStedproceduresareextremelysimilartotheconstructsseeninotherprogramminglanguages.Theyacceptdatainth

6、efmofinputparametersthatarespecifiedatexecutiontime.Theseinputparameters(ifimplemented)areutilizedintheexecutionofaseriesofstatementsthatproducesomeresult.Thisresultisreturnedtothecallingenvironmentthroughtheuseofarecdse

7、toutputparametersareturncode.Thatmaysoundlikeamouthfulbutyoullfindthatstedproceduresareactuallyquitesimple.ExampleLetstakealookatapracticalexample.AssumewehavethetableshownatthebottomofthispagenamedInventy.Thisinfmationi

8、supdatedinrealtimewarehousemanagersareconstantlycheckingthelevelsofproductsstedattheirwarehouseavailablefshipment.Inthepasteachmanagerwouldrunqueriessimilartothefollowing:ProductQuantityFROMInventyWHEREWarehouse=FLThisre

9、sultedinveryinefficientperfmanceattheSQLServer.Eachtimeawarehousemanagerexecutedthequerythedatabaseserverwasfcedtorecompilethequeryexecuteitfromscratch.ItalsorequiredthewarehousemanagertohaveknowledgeofSQLappropriateperm

10、issionstoaccessthetableinfmation.Wecansimplifythisprocessthroughtheuseofastedprocedure.Letscreateaprocedurecalledsp_GetInventythatretrievestheinventylevelsfagivenwarehouse.HerestheSQLcode:CREATEPROCEDUREsp_GetInventy@loc

11、ationvar(10)大連交通大學(xué)2011屆本科生畢業(yè)設(shè)計(jì)（論文）外文翻譯3IF(@Quantitydered(QuantityOnHFROMInventyWHEREPartID=@Partdered))BEGINSQLstatementstoupdatetablesprocessder.ENDELSEBEGINstatementtoretrievetheIDsofalternateitemstosuggestasreplacemen

12、tstothecustomer.ENDApplicationsdonotneedtotransmitalloftheSQLstatementsintheprocedure:theyhavetotransmitonlyanEXECUTECALLstatementcontainingthenameoftheprocedurethevaluesoftheparameters.Stedprocedurescanalsoshieldusersfr

13、omneedingtoknowthedetailsofthetablesinthedatabase.Ifasetofstedproceduressupptsallofthebusinessfunctionsusersneedtoperfmusersneverneedtoaccessthetablesdirectlytheycanjustexecutethestedproceduresthatmodelthebusinessprocess

14、eswithwhichtheyarefamiliar.AnillustrationofthisuseofstedproceduresistheSQLServersystemstedproceduresusedtoinsulateusersfromthesystemtables.SQLServerincludesasetofsystemstedprocedureswhosenamesusuallystartwithsp_.Thesesys

15、temstedproceduressupptalloftheadministrativetasksrequiredtorunaSQLServersystem.YoucanadministeraSQLServersystemusingtheTransactSQLadministrationrelatedstatements(suchasCREATETABLE)thesystemstedproceduresneverneedtodirect

16、lyupdatethesystemtables.StedProceduresExecutionPlansInSQLServerversion6.5earlierstedprocedureswereawaytopartiallyprecompileanexecutionplan.Atthetimethestedprocedurewascreatedapartiallycompiledexecutionplanwasstedinasyste

17、mtable.ExecutingastedprocedurewasmeefficientthanexecutinganSQLstatementbecauseSQLServerdidnothavetocompileanexecutionplancompletelyitonlyhadtofinishoptimizingthestedplanftheprocedure.Alsothefullycompiledexecutionplanfthe

18、stedprocedurewasretainedintheSQLServerprocedurecachemeaningthatsubsequentexecutionsofthestedprocedurecouldusetheprecompiledexecutionplan.SQLServer2000SQLServerversion7.0incpateanumberofchangestostatementprocessingthatext

19、endmanyoftheperfmancebenefitsofstedprocedurestoallSQLstatements.SQLServer2000SQLServer7.0donotsaveapartiallycompiledplanfstedprocedureswhentheyarecreated.AstedprocedureiscompiledatexecutiontimelikeanyotherTransactSQLstat

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