ETL工程师面试题.pdf

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1、ContentsContents..........................................................................................................................................1DataWarehousingquestions.............................................................................

2、..............................1SQLquestions.................................................................................................................................1Unixquestions......................................................................

3、..........................................................3InformaticaQuestions.....................................................................................................................5MultipleChoice&True/FalseQuestions.........................

4、..........................................................5DataWarehousingquestions1.WhatisDataWarehousing?Whydoweneedit?2.Whatisadhocanalysis?3.DescribeOLAPandOLTPsystemsOLAPvs.OTLP:listfivemaindifferences.4.Whatisafacttableinadimensionalmodel?Whatisadime

5、nsiontable?5.CharacterizeSTARandSNOWFLAKEschemas.6.WhatisaSlowChangingDimension?Listallknowntypes;describeimplementationtechniques.7.Whatisalookuptable?8.WhydoweneedDimensionNormalization?9.Listanddescribestoragemodelssupportingmultidimensionalanalysis(lis

6、tprosandconsforeach).10.WhatisETL?11.WhatisaDataMart?12.DescribeSliceandDicetechniques.13.WhatisthemaindifferencebetweenKimball’sandInmon’sapproaches?14.Whatisadatamining?Listanddescribedataminingtasks.SQLquestions1.WhatdoestheabbreviationSQLstandfor?2.How

7、wouldyoulistalltherecordsinatable?13.WhatisSQL92?Forthenextpart,let'sdefinethefollowingentitiesandrelationships:entityCUSTOMERattributes:CUSTOMER_ID,CUSTOMER_NAMEentityACCOUNTattributes:ACCOUNT_NO,CUSTOMER_ID,BALANCEentityEMPLOYEEattributes:EMPLOYEE_ID,EMP

8、LOYEE_NAME,REPORTS_TOentityPROJECTattributes:PROJ_ID,PROJ_NAME,PROJ_LOCATION_ID,PROJ_CITYThefollowingbusinessrulesmustapply:ThefieldREPORTS_TOisnullforexactlyoneemployee,otherwiseitisoneofthenumbersfoundincol