V$system_event中Wait事件的一段话和resources_wait.sql

<script type="text/javascript"><!--google_ad_client = "pub-2947489232296736";/* 728x15, 创建于 08-4-23MSDN */google_ad_slot = "3624277373";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript"src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>

<script type="text/javascript"><!--google_ad_client = "pub-2947489232296736";/* 160x600, 创建于 08-4-23MSDN */google_ad_slot = "4367022601";google_ad_width = 160;google_ad_height = 600;//--></script><script type="text/javascript"src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>

V$system_eventshowsthetotalnumberofwaitsandtimeouts,andthetotal
waitingtimerecordedforeachtypeofevent,accumulatedforallprocessesover
thelifeoftheinstance.Itisnormaltoordertheeventswaitedforindescending
orderofthetotaltimewaited,asanindicatorofthepotentialseverityofeach
typeofwait.
However,thetotaltimewaitedisreallyonlymeaningfulforthosethatindicate
waitingforresources.Ifprocesseshavebeenwaitingbecausetheyhavenowork
todo,thenthetimewaitedisimmaterial.Iftheyhavebeenwaitingforroutine
operations,suchasdiskI/O,thenthetotaltimewaitedwilldependonthe
workload.Insuchcases,theaveragetimewaitedismuchmoreinterestingthan
thetotaltimewaited.
Thisclassificationofwaittypesintoidlewaits,routinewaits,andresourcewaits
isvitaltoacorrectunderstandingofthewaitstatistics.Accordingly,APThas
separatescriptsforresourcewaitsandroutinewaits,andignoresidlewaits
altogether.Theroutine_waits.sqlscriptshowsonlytheaveragetimewaitedfor
eachtypeofroutinewait.Theresource_waits.sqlscript(seeExample2.1)shows
thetypesofresourceswaitedforindescendingorderofthetotaltimewaited,but
alsoshowstheaveragetimewaited.


resources_wait.sql:


-----------------------------------------------------------------------------------Script:resource_waits.sql--Purpose:toshowthetotalwaitingtimeforresourcetypes----Copyright:(c)1998IxoraPtyLtd--Author:SteveAdams---------------------------------------------------------------------------------@reset_sqlpluscolumnaverage_waitformat9999990.00selectsubstr(e.event,1,40)event,e.time_waited,e.time_waited/(e.total_waits-decode(e.event,'latchfree',0,e.total_timeouts))average_waitfromsys.v_$system_evente,sys.v_$instanceiwheree.event='bufferbusywaits'ore.event='enqueue'ore.event='freebufferwaits'ore.event='globalcachefreelistwait'ore.event='latchfree'ore.event='logbufferspace'ore.event='parallelqueryqreflatch'ore.event='pipeput'ore.event='writecompletewaits'ore.eventlike'librarycache%'ore.eventlike'logfileswitch%'or(e.event='rowcachelock'andi.parallel='NO')unionallselect'non-routinelogfilesyncs',round(e.average_wait*greatest(e.total_waits-s.value,0)),e.average_waitfromsys.v_$system_evente,sys.v_$sysstatswheree.event='logfilesync'ands.name='usercommits'orderby2desc/@reset_sqlplus其中和reset_sqlplus是：

-----------------------------------------------------------------------------------Script:reset_sqlplus.sql--Purpose:toresetsqlplussettings----Copyright:(c)1998IxoraPtyLtd--Author:SteveAdams---------------------------------------------------------------------------------clearbreaksclearcolumnsclearcomputessetfeedbackoffsetverifyoff
资料来源：8iInternalServices













<script type="text/javascript"><!--google_ad_client = "pub-2947489232296736";/* 728x15, 创建于 08-4-23MSDN */google_ad_slot = "3624277373";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript"src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>

<script type="text/javascript"><!--google_ad_client = "pub-2947489232296736";/* 160x600, 创建于 08-4-23MSDN */google_ad_slot = "4367022601";google_ad_width = 160;google_ad_height = 600;//--></script><script type="text/javascript"src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script>