les05_数据字典和性能视图.ppt

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1、UsingDataDictionaryandDynamicPerformanceViewsObjectivesAftercompletingthislesson,youshouldbeabletodothefollowing:Identifybuilt-indatabaseobjectsIdentifythecontentsandusesofthedatadictionaryDescribehowdatadictionaryviewsarecreatedIdentifydatadictionaryviewcategoriesQuerythedatadictio

2、naryanddynamicperformanceviewsDescribeadministrativescriptnamingconventionsBuilt-InDatabaseObjectsOtherobjectscreatedwiththedatabase:DatadictionaryPerformancetablesPL/SQLpackagesDatabaseeventtriggersDataDictionaryCentraltoeveryOracledatabaseDescribesthedatabaseanditsobjectsContainsre

3、ad-onlytablesandviewsStoredintheSYSTEMtablespaceOwnedbytheuserSYSMaintainedbytheOracleserverAccessedwithSELECTControlfilesDatafilesRedoLogfilesDatabaseDataDictionarytablesBaseTablesandDataDictionaryViewsThedatadictionarycontainstwoparts:BasetablesStoresdescriptionofthedatabaseCreate

4、dwithCREATEDATABASEDatadictionaryviewsUsedtosimplifythebasetableinformationAccessedthroughpublicsynonymsCreatedwiththecatalog.sqlscriptCreatingDataDictionaryViewsScriptPurposecatalog.sqlCreatescommonlyuseddatadictionaryviewsandsynonymscatproc.sqlRunsscriptsrequiredforserver-sidePL/SQ

5、LDataDictionaryContentsThedatadictionaryprovidesinformationabout:LogicalandphysicaldatabasestructuresDefinitionsandspaceallocationsofobjectsIntegrityconstraintsUsersRolesPrivilegesAuditingHowtheDataDictionaryIsUsedPrimaryuses:OracleserverusesittofindinformationaboutUsersSchemaobjects

6、StoragestructuresOracleservermodifiesitwhenaDDLstatementisexecuted.UsersandDBAsuseitasaread-onlyreferenceforinformationaboutthedatabase.DataDictionaryViewCategoriesThreesetsofstaticviewsDistinguishedbytheirscope:DBA:WhatisinalltheschemasALL:WhattheusercanaccessUSER:Whatisintheuser’ss

7、chemaUSER_xxxObjectsownedbythecurrentuserALL_xxxObjectsaccessiblebythecurrentuserDBA_xxxAlloftheobjectsinthedatabaseDataDictionaryExamplesGeneraloverview:DICTIONARY,DICT_COLUMNSSchemaobjects:DBA_TABLES,DBA_INDEXES,DBA_TAB_COLUMNS,DBA_CONSTRAINTSSpaceallocation:DBA_SEGMENTS,DBA_EXTENT

8、SDatabasestr