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SAP HANA Interview Questions

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  1. SAPHANAINTERVIEWQUESTIONS 1.Statethedifferenttypesofreplicationtechniques? Thethreetypesareasbelow: ETLbasedreplicationusingBODS TriggerbasedreplicationusingSLT ExtractorbaseddataacquisitionusingDXC 2. WhatisSLT? ThefullformofSLTisSAPLandscapeTransformationwhichisnothingbutatriggerbasedreplication.It isthereplicationtechnologytopassthedatafromthesourcesystemtothetargetsystem.Herethesource canbe eitherSAPornon-SAPwhereastheTargetsystemisSAPHANAsystemwhichcontainsHANA database. 3.Canweloadandreplicatedatafromonesourcesystemto multipletargetdatabase schemasofHANAsystem? Yes.Itcanbeloadedandreplicatedforupto4. 4.Canthetypeofdataloadandreplicationbespecified? Itcanbe eitherinrealtime,orscheduledby timeorbyinterval. 5.DefineConfigurationinSLT? Theinformationrequiredtocreatetheconnectionbetweenthesourcesystem,SLTsystem,andtheSAP HANAsystemisspecifiedwithintheSLTsystemasaConfiguration.AnewconfigurationinConfiguration &MonitoringDashboard(transactionLTR)canhencebedefined. 6.Isthereanyneedofpre-requisitebeforecreatingtheconfigurationandreplication? DMISadd-onisinstalledinSLTreplicationserverforSAPsourcesystems.Therole IUUC_REPL_REMOTEisassignedtotheuserforRFCconnectionbutnotDDIC.DMISadd-onisnot requiredandgrantsadatabaseusersufficientauthorizationfordatareplicationforanon-SAPsource system. 7.DefinewhatisConfigurationandMonitoringDashboard? TheyareapplicationsthatrunonSLTreplicationservertospecifyconfigurationinformation(suchas sourcesystem,targetsystem,andrelevantconnections)sothatdatacanbe replicated.Thereplication status(transactionLTR)canalsobe monitored. StatusYellowoccursduetotriggerswhicharenotyetcreatedsuccessfully. StatusRedoccursifmasterjobisaborted(manuallyintransactionSM37). 8. Whatisadvancedreplicationsettings? AdvancedReplicationsettingsisatransactionthatrunsonSLTreplicationservertospecifyadvanced 1 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  2. replicationsettingslikemodifyingtargettablestructures,specifyingperformanceoptimizationsettingsreplicationsettingslikemodifyingtargettablestructures,specifyingperformanceoptimizationsettings thatdefinestransformationrules. 9DefineLatency? Latencyisthelengthoftimetoreplicatedata(atableentry)fromthesourcesystemtothetargetsystem. 10.Whatisloggingtable? Aloggingtableinthesourcesystemthatcanrecordanychangestoatablethatisbeingreplicated.This therebyensuresthatSLTreplicationservercanreplicatethesechangestothetargetsystem. 11.WhatareTransformationrules? TransformationruleisarulespecifiedintheAdvancedReplicationsettingstransactionforsourcetables suchawaythatthedataistransformedduringthereplicationprocess.Forexampleonecanspecifyruleto Convertfields,FillemptyfieldsandSkiprecords 12.Whena newconfigurationissetupwhathappens? ThedatabaseconnectionisautomaticallycreatedalongwithGUIDandMasstransferid(MT_ID). ConfigurationswiththesameschemanamecanbecreatedwhichisensuredbyschemaGUID. ThenamingofSLTjobsandthesystemcanuniquelyidentifyaschemawheretheMasstransferIDis used. 13.Whatarethefactorsthatinfluencethechange/increasethenumberofjobs? Thefactorsthatinfluencethechangeor increaseinthenumberofjobsarenumberofconfigurations managedbytheSLTreplicationserver,numberoftablestobeloaded/replicatedforeachconfiguration, expectedspeedofinitialload,expectedreplicationlatencytime. Asathumbrule,oneBDGjobshouldbe usedforeach10tablesinreplicationtoachieveacceptablelatencytimes. 14.WhenisthenumberofDataTransferjobschanged? ThenumberofdataTransferjobschangeswhenthespeedoftheinitialload/replicationlatencytimeis notsatisfactory,ifSLTreplicationserverhas moreresourcesthanthatisinitiallyavailable.Thenumberof initialloadjobsmaybe reducedafterthecompletionoftheinitialload 15.Mentionthejobsinvolvedinreplicationprocess? Themainjobsinvolvedinthereplicationprocessarestatedasbelow: MasterJob(IUUC_MONITOR_<MT_ID>) MasterControllingJob(IUUC_REPLIC_CNTR_<MT_ID>) Data LoadJob(DTL_MT_DATA_LOAD_<MT_ID>_<2digits>) Migration ObjectDefinitionJob(IUUC_DEF_MIG_OBJ_<2digits>) AccessPlanCalculationJob(ACC_PLAN_CALC_<MT_ID>_<2digits>) 16.Statetherelationbetweenthenumberofdatatransferjobsintheconfiguration settingsandtheavailableBGDworkprocesses? InSLTreplicationservereachjoboccupies1BGDworkprocessesandforeachconfiguration,the parameterDataTransferJobswouldrestrictthemaximumnumberofdataloadjobforeachmass 2 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  3. transferID(MT_ID). Atleast4backgroundjobsarerequiredforamasstransferIDrequirestobeavailable.TheyareOne masterjob,Onemastercontrollerjob,Atleastonedataloadjob,Oneadditionaljobeitherfor migration/accessplancalculation/tochangeconfigurationsettingsin“ConfigurationandMonitoring Dashboard”. 17.Iftheparametersetfor“datatransferjobs”to04inaconfiguration“SCHEMA1”,a masstransferID001isassigned.Insucha casewhatjobsshouldbeinthesystem? Thejobsshouldbe1Masterjob(IUUC_MONITOR_SCHEMA1),1MasterControllerjob (IUUC_REPL_CNTR_001_0001)andatmost4paralleljobsforMT_ID001 (DTL_MT_DATA_LOAD_001_01/~02/~03/~04) Ifatthesametimelotsoftablesareselectedforload/replication,therecouldbe achancethatthereare notenoughbackgroundjobsavailabletostarttheload procedureforalltablesimmediately.Insuchacase thenumberofinitialloadjobscanbeincreased,orelsetableswillbehandledsequentially. Fortableswithlargevolumeofdatathetransaction“AdvancedReplicationSettings (IUUC_REPL_CONT)”tofurtheroptimizetheloadandreplicationprocedurefordedicatedtablescanbe used. 18.AftertheSLTreplicationisoverwhathappens? Afterthereplicationisover,theSLTreplicationservercreates1user,4roles,2storedproceduresand8 tablesasmentionedbelow: 1User 1Privilege 4Roles <REPLICATIONSCHEMA>_DATA_PROV <REPLICATION_SCHEMA>_POWER_USER <REPLICATION_SCHEMA>_USER_ADMIN <REPLICATION_SCHEMA>_SELECT 2Storedprocedures RS_GRANT_ACCESS,RS_REVOKE_ACCESS 8Tables DD02L,DD02T,RS_LOG_FILES,RS_MESSAGES,RS_ORDER,RS_ORDER_EXT, RS_SCHEMA_MAP,RS_STATUS 19.Statethedifferentreplicationscenarios? ThedifferentreplicationscenariosareLoad,Replicate,Stop,SuspendandResume. Beforeanyapplicationtableisselected,theinitialloadofthetablesDD02L,DD02T&DD08Lmustbe completedastheycontainthemetadatainformation. Load:Thisstartsaninitialloadofreplicationdatafromthesourcesystem.Thecompleteprocedureisa one-timeevent.Oncecompleted,furtherchangestothesourcesystemdatabasewillnotbereplicated. Alsofortheinitialloadprocedure,neitherdatabasetriggersnorloggingtablesarecreatedinthesource system.Thedefaultsettingsusereadingtype3(DB_SETGET)withupto3backgroundjobsinparallelto loadtablesinparallelorsubsequentlyintotheHANAsystem. Replicate:Thiscombinesaninitialloadprocedureandthesubsequentreplicationprocedure(realtimeor 3 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  4. scheduled). Beforethestartofinitialloadprocedure,triggerofdatabaseandrelatedloggingtablearecreatedforeach tableinthesourcesystemaswellasinSLTreplicationserver. StopReplication:Thisstopsanycurrentloadorreplicationprocessofatable. Thestopfunctionremovesthedatabasetriggerandrelated loggingtablescompletely.Thisfunctionis usedonlyifyouwanttocontinueaselectedtableotherwiseitmustbeinitiallyloadedagaintoensuredata consistency. Suspend:Thispausesatablefromarunningreplication.Alsothedatabasetriggerwillnotbedeletedfrom thesourcesystem.Therecordingofchangeswouldcontinueandtherelatedinformationwouldbestored intherelatedloggingtablesinthesourcesystem. Iftablesaresuspendedforalongtimethesizeofloggingtablesmayincreaseandadjustthetablespaceif required. Resume:Thisrestartstheapplicationforasuspendedtable.Theprevioussuspendedreplicationwillbe resumed(nonewinitialloadrequired). 20.IfthereplicationissuspendedforalongperiodoftimeorsystemoutageofSLTor HANAsystemwhatwouldhappen? Thesizeoftheloggingtablesincreases. 21.Howcanunnecessarylogginginformationfrombeingstoredbeavoided? Unnecessarylogginginformationstoragecanbeavoidedby pausingthereplicationwhichisbystopping theschema-relatedjobs. 22.ArethetablesizeinSAPHANAdatabaseandin thesourcesystemthesame? NotheyarenotsameasHANAdatabasesupportscompression. 23.Whenistablepartitioningopted? IfthetablesizeinHANAdatabaseexceeds2 billionrecords,thetableshouldbesplittedbyusing portioningfeaturesbyusing“Advancedreplicationsettings”(transactionIUUC_REPL_CONT,tabpage IUUC_REPL_TABSTG). 24.Wherearetransformationrulesdefined? Transformationrulesaredefinedbyusing“Advancedreplicationsettings”(transaction IUUC_REPL_CONT,tabpageIUUCASSRULEMAP) 25.Ifthesourcesystemisnon-SAPsystem,arethereanyspecialconsiderations? Thetrigger-basedreplicationconceptisactuallymeantforSAPsourcesystems.Themaindifferencesare asbelow: a)Therewouldbea databaseconnectionbetweennon-SAPsourceandSLTsysteminsteadofRFC. b)Sourcemusthaveprimarykey c)TablesDD02L,DD02Twhichcontainsmetadataarejustinitiallyloadedbutnot replicated. d)ThereadmodulesresidesonSLTsystem. e)Tableswithdatabasespecificformatsmayneedtransformationrulesjustbeforetheyarereplicated. 4 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  5. f)OnlySAPsupporteddatabases(withrespectiveDBSLforSAPNetWeaver7.02)aresupportedasnon-f)OnlySAPsupporteddatabases(withrespectiveDBSLforSAPNetWeaver7.02)aresupportedasnon- SAPsourcesystems. 26.Statethepotentialissuesin thecreationofaconfiguration? Themostpotentialissuesintheconfigurationcreationisthemissingadd-onDMIS_2010insource system,missingtheproperroleofSAP_IUUC_REPL_REMOTEforRFCuser (SAP_IUUC_USERforSLTsystem)andiftheLogoncredentialsarenotcorrect 27.HowisitensuredthatdataisconsistentinsourcesystemandHANAsystem? Sinceanychangesinthesourcesystemthatoccursistrackedinthededicatedloggingtables,the replicationstatusforeachchangeddatarecordwillbetransparent.Anentryofloggingtableisdeleted afteraneverysuccessfulcommitstatementfromHANAdatabaseandthisprocedureensuresthedata consistencybetweensourcesystemandHANAsystem. 28.DoesSLTforSAPHANAsupportdatacompressionlikeSAPHANAdatabase? YesSLTforSAPHANAsupportsdatacompressionlikeSAPHANAdatabaseandthisisautomatically coveredbythe RFCconnectionusedfordatareplicationfromtheSAPsour. 29.WhataretheproductnamesinSAPHANA? Inshortanswerit'samystery.AlotofchangeshavehappenedaroundSAPandnowit’scalledSAPHANA Appliance,SAPHANADatabaseandSAPHANAStudio.AllapplicationsbuiltonHANAwillbe marked "poweredbySAPHANA".Andthisisprobablytobechangedagain. 30.WhatisSAPHANAAppliance1.0? SAPHANA1.0isananalyticsappliancewhichconsistsofcertifiedhardware,andInMemoryDataBase (IMDB),anAnalyticsEngineandsometoolingforgettingdatainandoutofHANA.Thelogicand structuresarebuiltbytheuserandatoolisusede.g.SAPBusinessObjects,tovisualizeoranalyzedata. 31.StatethelimitationsofHANA1.0? Thelimitationsareveryless.Itcanonlyreplicatecertaindatafromcertaindatabasesandincertain formatsusingtheSybaseReplicationServer.TheBatchloadingisdoneusingSAPBusinessObjectsData Services4.0andisoptimizedonlyforSAPBusinessObjectsBI4.0reporting. 32.WhatisSAPHANA1.5,1.2or1.0SP03? Theyareallthesamething,and1.0SP03istoutedtobethefinalnamewhichshouldgointoRampUp (beta)inQ42011.ThisallowsanySAPNetWeaverBW7.3DataWarehousetobe migratedintoaHANA appliance.HANA1.0SP03specificallyalsoacceleratesBWcalculationsandplanning,whichmeanseven moreperformancegainscanbeattained. 33.DifferentiatebetweenHANAandIMDB? HANAisthenameforthecurrentBIappliance(HANA1.0)andtheBWDataWarehouseappliance (HANA1.0SP03).BothusetheSAPIMDBDatabaseTechnology(SAPHANADatabase)astheir underlyingRDBMS.SAPcanbe expectedtostarttodifferentiatethismoreclearlyasitstartstoposition thetechnologyforusecasesotherthanAnalytics. 5 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  6. 34.IfNetWeaverBWcanberunonIMDB/HANA,whycan'ttheBusinessSuite/ERP6.0be34.IfNetWeaverBWcanberunonIMDB/HANA,whycan'ttheBusinessSuite/ERP6.0be runtoo? Thisisbecauseit'snotmatureenoughtosupportbusinesscriticalapplications.Fromatechnology perspective,itisanywayspossibletorunthe BusinessSuiteonIMDBandSAPhastrialedmovingsome largedatabasesintoIMDBalready. 35.WhatisHANAexcellentat? Themostimportantthingtonoteis,HANAbringstothetableistheabilitytoaggregatelargedata volumesinnearreal-time-andtohavethedataupdatedinnearreal-time.Demosshowhundredsof billionsofrecordsofdatabeingaggregatedinamatterofseconds.HenceSAPhas builtasetofAnalytics AppsontopofHANAandthesearesettobegreatpointusecasestogetcustomersupandrunning quickly. 36.WhatisHANAnotgoodat? SomecurrentissueshavebeennoticesaroundHANAwhendeliveringad-hocanalytics,especiallywhen usingtheSAPBusinessObjectsWebitool.Nodoubtthattheproblemisthatonecanaskcomputationally verydifficultquestionswithWebi,whichcausesverylongresponsetimeswithHANA.SAPneedstobuild optimizationforbothWebiandHANAtoreducethecomputationalcomplexityofthesequestions. 37.WhatisthecostofHANA? ThelicensingcostofHANAisnotconfirmedbSAPbut thehardwareissomewherearound$1-200kper TB.Inadditiontotheselicensingcoststhisisstillbeingmadeonaper-customerbasis. 38.WhatisthereasonforthespeedofHANA? Theinformationcanbe retrievedfromRegularRDBMStechnologiesputtheinformationonspinning platesofiron(harddisks).Theinformationisstoredinelectronicmemory,whichissome50xfaster (dependingonhowyoucalculate).Itstoresacopyonmagneticdisk,incaseofpowerfailureorthelike. Alsotoaddin,mostSAPsystemshavethedatabaseononesystemandacalculationengineonanother, andtheinformationispassedbetweenthem.WithHANA,thisall happenswithinthesamemachine. 39.IsOraclereplacedbyHANA/IMDB? Oncethe BusinessSuiterunsonIMDB,OraclewillnotbeneededformanymorebySAPcustomerswho purchaseHANA.Theshorttermisnotaffectedbecauseevenif HANAisboughttodayitstillneedsan OracleERPsystem. 40.Statethe10:1compressionwithHANAwhencomparedtoOracle? Whena typicaluncompressedOracleorMicrosoftSQLServerdatabaseisputintoHANA,itwillbe10x smallerthanbeforeandthisisbecauseofthewaythatHANAstoresinformationinacompressed format.Mostdatabasesarenowcompressedandthesenumbersmaynotfiteveryscenario,andtoaddto this2x the RAMasyourdatabaseisneededincludingaplusroomforgrowth.SizingofHANAisstilla darkart. 6 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  7. 41.Whatismeantby“buyaHANAonly2.5xsmallerthanmybigOracleRDBMS”?How41.Whatismeantby“buyaHANAonly2.5xsmallerthanmybigOracleRDBMS”?How aboutarchivinganddataageing? InsomeinstancesHANAappliancethatisonly2.5xsmallerthanitwouldbeunderOracleandonlythis canbe bought.Dataageingisnotapartofthe1.0release,butSAPiscertainlyworkingonit. 42.What'stheextendedmarketopportunityforIMDB? Afewanalystsseemtohavetappedonthatthewidermarketopportunitywhichisbelievedtobe huge. NotonlySAPapplicationsbutanythirdpartythatrequiresultra-highspeed.It’s notjustanappliancebut adevelopmentplatform. 43.WhathardwareissupportedinSAPHANArightnow? Allofthemajorvendorse.g.HP,IBM,Dell,areofferingHANAnow.TechnicallyHANAwillrunonany Intelx64basedsystemfromyourlaptopthroughtothebig40-core,2TBRAMservers.Itishoweveronly supportedonasmallnumberofbigrack-mountserversliketheDellR910andHPDL980. 44.DoesHANArunonblades?Ifnotwhy? It'sstillnotclearbut probablybecausethe bladesdoesn’tyetofferthesameperformance.HANAis optimizedfortheIntelX7560CPUandrunsfastestonthis.Forinstance,theDellM910bladecanonly run2xX7650CPUsand512GbRAMinthisconfiguration,whichprobablyexplainsthelimitations.One thingissurethatHANAwilleventuallyrunonbladesasit'sborntorunonbladetechnology. 45.CANSAPmaketheirownIMDB/HANAhardware? Itcanbutonly inthelabssofar.NosuchpublicplanstocompeteagainstIBM/HP/Dellisthereinthis space,butitcouldmakesenseforSAPtoentertheappliancemarket,especiallyinthecontextofData CentersandevenmoresointhecontextoftheSAPBusinessbyDesigncloudoffering,whichwillrunon IMDB. 46.HowbigdoesHANAscale? Theorywiseatleastverywell.Mostmid-sizeworkloads-2TBofin-memorystorageisequivalentto5- 20TBofOraclestoragecanberunbythe biggestsingleserverHANAhardware.HANAworksinaway thatmeansitispossibletochainmultiplesystemstogetherwhichmeansthatscalabilityhasthus-farbeen determinedbythesizeofcustomers'wallets.WhilstSAPtalkup"BigData"quitealot,HANAcurrently onlyscalestothesmall-endofBigDatareferringtothe kindofhugedatasetsthatFaceBookor Google havetostore-notTerabytes,butratherPetabytes. 47.HANAuseswhichstoragesubsystem? Asharednetworkattachedandvariesfromvendortovendorandiscalledthestorage.Herebothregular magneticdisksandSSDstoragecanbeusedforthebackupofthedatabase(HANArunsinmemory remember,sodiskstorageisjustforbackup,andlater,fordataageing).Iftheoperatorrequire2xstorage thatyouhaveRAM,whichis2xthedatabasesize-i.e.storagesize=4xdatabasesize.Anywaysinmost casesthereisadditionalultra-highspeedSSDstorageforlogfiles. 48.HANAsupportinreal-timewhattypesofsourcedatabase? IfSybaseReplicationServer(SRS)fornearreal-timedataisusedthenthelicensingstill(SAPhavelicense 7 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS

  8. dealspending)needstochecked.IfDB2isrunthenits finebutwithOracleandMicrosoftSQLServer therearesomelicensechallenges.SoiflicenseisboughtthroughSAP,becauseyoumayhavealimited licensethatdoesnotallowextraction. 49.ForbatchloadswhatsourcedatabasesdoesHANAsupport? IfSAPBusinessObjectsDataServices4.0 isusedforbulkloadsthenitwouldbethebest.BO-DSisavery flexibleExtract,Transform&Loadtoolthatcansupportmanydatabases 50.WhatadditionallimitationsdoesSybaseReplicationServerpresent? SRShasadditionalrestrictionswhichareworthtobeunderstood.ItonlyreplicatesUnicodedataand doesnotsupportIBMDB2compresstables. WanttoLEARNSAPHANA? GettrainedbySAPHANAexperts.KnowaboutSAPHANATraining course http://www.bestonlinetrainers.com/bigdata/sap-hana-training.html REGISTERFORFREEDEMOTODAY http://www.bestonlinetrainers.com/demo/index.html Trustedby1000+ trainees info@bestonlinetrainers.com USA:+(1)6783896789|UK:+(44)-2032393637|India:+(91)9246449191 8 www.bestonlinetrainers.com SAPHANAINTERVIEWQUESTIONS