Oracle学习笔记-好处多多.doc

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1、1、DDL(DataDefinitionLanguage)Commandcreate,alter,dropobjects;grant,revokeprivilegesandroles;establishingauditingoptions;addcommentstothedatadictionary;BeforeandaftereachDDLstatement,Oracleimplicitlycommitthecurrenttransactions.2、DML(DataManipulationLanguage)

2、CommandQueryandModifydatawithinexistingschemaobjects;DMLstatementsconsistofDELETE,INSERT,SELECTandUPDATEstatements;EXPLAINPLANstatements;LOCKTABLEstatements;UnlikeDDLCommand,acommitisnotimplicit,afterexecuteDDLCommand,mustexecutecommitcommandtocommitatransac

3、tion;3、DynamicPerformanceTablesThesetablesarecreatedattheinstancestartupandusedtostoreinformationabouttheperformanceoftheinstance.Thisinformationincludesconnectioninformatioion,I/OS,initializationparametervaluesandsoon..4、ProcedureandFunctionareidenticalexce

4、ptthatFounctionarealwaysreturnavalue(Proceduredonot).5、SchemaisacollectionofObjectsthatassociatedwiththeDataBase.6、SGAismadeupof:DataBaseBuffers;RedoLogBuffers;TheSharedPool;7、TransactionisalogicalunitofworkconsistingofoneormoreSQLstatements,endinginacommito

5、rrollback.8、TheDataBaseThePhysicalLayer（1）Oneormoredatafiles;（2）Twoormoreredologfiles;（3）Oneormorecontrolfiles;TheLogicalLayer（1）Oneormoretablespaces;（2）Thedatabaseschema;9、Thedatabaseisdevidedintooneormorelogicalpiecesknownastablespace;10、Recommendthatevery

6、oneneedDBArolesshouldhaveadifferentaccount,thus,ifauditingisenabled,thereisarecordwhomadethesesystemchanges.11、TheInstanceisthelogicaltermthatreferstothecomponentsnecessarytoaccessthedatainadatabase.12、数据库实例（也称为服务器Server），是用来访问一个数据库文件集的一个存储结构及后台进程的集合。Oralce并

7、行服务器是指一个单独的数据库可以被多个实例访问。13、查询实例名：selectinstance_namefromv$instance；14、查询动态视图v$waitstat、v$system_event、v$session_event、v$session_wait和v$buffer_pool_statistics（在Oracle8中通过catperf.sql脚本创建）以获取下面所的统计信息，目的是为了检查服务器进程是否正等待DBWR（对单个会话而言，也对整个数据库而言）。15、(1)SMON：系统监控程序(2)

8、PMON：进程监控程序(3)DBWR：数据库写入程序(4)LGWR：日志写入程序(5)CKPT：检查点进程(6)ARCH：归档日志(7)RECO：恢复进程(8)SNPn：快照进程(9)LCKn：锁定进程(10)Dnnn：调度程序进程(11)Snnn：服务器进程(12)Pnnn：并行查询服务器进程16、数据库备份之前，若使用了shutdownabort命令，则需要进行如下操作，然后才能进