oracle性能优化(简单版)

--数据库巡检或性能优化方法各异，但首要的是要发现数据库性能瓶颈，系统自带的statspack,或awr太耗时，

--以下是本人常用的方法，共享之

--1、查询数据库等待事件top10,关注前前几个等待事件，关注前三个等待事件是否有因果或关联关系

--oracle 9i

select t2.event,round(100*t2.time_waited/(t1.w1+t3.cpu),2) event_wait_percent from ( SELECT SUM(time_waited) w1 FROM v$system_event WHERE event NOT IN

('smon timer','pmon timer','rdbms ipc message','Null event','parallel query dequeue','pipe get', 'client message','SQL*Net message to client','SQL*Net message from client','SQL*Net more data from client',

'dispatcher timer','virtual circuit status','lock manager wait for remote message','PX Idle Wait',

'PX Deq: Execution Msg','PX Deq: Table Q Normal','wakeup time manager','slave wait','i/o slave wait',

'jobq slave wait','null event','gcs remote message','gcs for action','ges remote message','queue messages') ) t1,

(select * from (

select t.event,t.total_waits,t.total_timeouts,t.time_waited,t.average_wait,rownum num from (select event,total_waits,total_timeouts,time_waited,average_wait from v$system_event where event not in

('smon timer','pmon timer','rdbms ipc message','Null event','parallel query dequeue','pipe get', 'client message','SQL*Net message to client','SQL*Net message from client','SQL*Net more data from client',

'dispatcher timer','virtual circuit status','lock manager wait for remote message','PX Idle Wait',

'PX Deq: Execution Msg','PX Deq: Table Q Normal','wakeup time manager','slave wait','i/o slave wait',

'jobq slave wait','null event','gcs remote message','gcs for action','ges remote message','queue messages')

order by time_waited desc ) t) where num<11) t2,

(SELECT VALUE CPU FROM v$sysstat WHERE NAME LIKE 'CPU used by this session' ) t3

--oracle10g

select t2.event,round(100*t2.time_waited/(t1.w1+t3.cpu),2) event_wait_percent from ( SELECT SUM(time_waited) w1 FROM v$system_event WHERE event NOT IN

('smon timer','pmon timer','rdbms ipc message','Null event','parallel query dequeue','pipe get','client message','SQL*Net message to client','SQL*Net message from

client','SQL*Net more data from client','dispatcher timer','virtual circuit status','lock manager wait for remote message','PX Idle Wait','PX Deq: Execution Msg','PX

Deq: Table Q Normal','wakeup time manager','slave wait',

'i/o slave wait','jobq slave wait','null event','gcs remote message','gcs for action','ges remote

message','queue messages','wait for unread message on broadcast

channel','PX Deq Credit: send blkd','PX Deq: Execute Reply','PX Deq: Signal ACK','PX Deque wait','PX Deq Credit: need buffer','STREAMS apply coord waiting for slave

message',

'STREAMS apply slave waiting for coord message', 'Queue Monitor Wait', 'Queue Monitor Slave Wait', 'wakeup event for builder', 'wakeup event for preparer', 'wakeup

event for reader',

'wait for activate message', 'PX Deq: Par Recov Execute','PX Deq: Table Q Sample','STREAMS apply slave idle wait','STREAcapture process filter callback wait for

ruleset','STREAMS fetch slave waiting for txns',

'STREAMS waiting for subscribers to catch up','Queue Monitor Shutdown Wait','AQ Proxy Cleanup Wait','knlqdeq','class slave wait','master wait','DIAG idle wait',

'ASM background timer','KSV master wait','EMON idle wait','Streams AQ: RAC qmn coordinator idle wait','Streams AQ: qmn coordinator idle wait','Streams AQ: qmn slave

idle wait',

'Streams AQ: waiting for time management or cleanup tasks','Streams AQ: waiting for messages in the queue','Streams fetch slave: waiting for txns','Streams AQ:

deallocate messages from Streams Pool',

'Streams AQ: delete acknowledged messages','LNS ASYNC archive log','LNS ASYNC dest activation','LNS ASYNC end of log','LogMiner: client waiting for transaction',

'LogMiner: slave waiting for activate message','LogMiner: wakeup event for builder','LogMiner: wakeup event for preparer','LogMiner: wakeup event for reader') ) t1,

(select * from (

select t.event,t.total_waits,t.total_timeouts,t.time_waited,t.average_wait,rownum num from (select event,total_waits,total_timeouts,time_waited,average_wait from v$system_event where event not in

('smon timer','pmon timer','rdbms ipc message','Null event','parallel query dequeue','pipe get','client message','SQL*Net message to client','SQL*Net message from

client','SQL*Net more data from client','dispatcher timer','virtual circuit status','lock manager wait for remote message','PX Idle Wait','PX Deq: Execution Msg','PX

Deq: Table Q Normal','wakeup time manager','slave wait',

'i/o slave wait','jobq slave wait','null event','gcs remote message','gcs for action','ges remote message','queue messages','wait for unread message on broadcast

channel','PX Deq Credit: send blkd','PX Deq: Execute Reply','PX Deq: Signal ACK','PX Deque wait','PX Deq Credit: need buffer','STREAMS apply coord waiting for slave