数据库系统英第三版课件2012版 Database Systems(10).ppt

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1、10AdvancedTopicsinRelationalDatabasesSecurityandUserAuthorizationinSQLRecursion(递归)inSQLTheObject-RelationalModelUser-DefinedTypesinSQLOperationsonObject-RelationalDataOn-LineAnalyticProcessingDataCubes(立方体)10.1.1PrivilegesAfilesystemidentifiescertainprivilegesontheobjects(files)itmanages.Typica

2、llyread,write,execute.SQLidentifiesamoredetailedsetofprivilegesonobjects(relations)thanthetypicalfilesystem.10.1.1PrivilegesSQLdefineninetypesofprivileges:SELECT=righttoquerytherelationorview.INSERT=righttoinserttuples.Mayapplytoonlyoneattribute.DELETE=righttodeletetuples.UPDATE=righttoupdatetup

3、les.Mayapplytoonlyoneattribute.REFERENCES=righttorefertotherelationinanintegrityconstraint.USAGE=righttousesomeelementinone’sowndeclaration.TRIGGER=righttodefinetriggersontherelation.EXECUTE=righttoexecuteapieceofcode.UNDER=righttocreatesubtypesofagiventype.10.1.1PrivilegesExample:INSERTINTOStud

4、io(name)SELECTDISTINCTstudioNameFROMMoviesWHEREstudioNameNOTIN(SELECTnameFROMStudio);WeneedtheprivilegeINSERTorINSERT(name)onStudio,andtheSELECTprivilegeonMoviesandStudio.10.1.1PrivilegesTheobjectsonwhichprivilegesexistincludestoredtablesandviews.Otherprivilegesaretherighttocreateobjectsofatype,

5、e.g.,triggers.Viewsformanimportanttoolforaccesscontrol.10.1.1PrivilegesExample:WemightnotwanttogivetheSELECTprivilegeonEmps(name,addr,salary).ButitissafertogivetheSELECTprivilegeon:CREATEVIEWSafeEmpsASSELECTname,addrFROMEmps;QueriesonSafeEmpsdonotrequireSELECTprivilegeonEmps,justonSafeEmps.10.1.

6、2CreatingPrivilegesDBA:DatabaseAdministrator,hasthehighestpriorityforallobjects.DBAcanbeassignedasaspecialprioritytosomeonebyauthorization(授权)DBAcancreatedatabaseobjectsforothers.Owner:Whensomeusercreateadatabaseobject,thentheuseris“owner”ofthisobject,andhastheprioritytoperformalltheoperationsfo

7、rtheobject.Everydatabaseobjecthasanuniqueowner.Fullnameofatableis“owner.table”,suchasdba.customer.Ownercanbeomittedonlyifcurrentuseristheownerofthetable.10.1.2CreatingPrivilegesAuthorization(授权)modelmembershipGroupUserDBObje