Wait Class
Waits
%Time -outs
Total Wait Time (s)
Avg wait (ms)
Waits /txn
User I/O
10,330,487
0.00
22,641
2
123.53
System I/O
267,610
531
3.20
Commit
82,427
0.02
230
3
0.99
Configuration
56,098
98.48
221
4
0.67
Network
18,616,191
35
222.62
Other
6,682
6.18
28
0.08
Concurrency
36,022
1.07
22
1
0.43
Application
4,692
0.06
管理類:Administrative
此類等待事件是由于DBA的管理指令引起的,這些指令要求使用者處于等待狀态,比如,重建索引。【Waits resulting from DBA commands that cause users to wait (for example, an index rebuild)】
應用程式類:Application
此類等待事件是由于使用者應用程式的代碼引起的(比如:鎖等待)【Waits resulting from user application code (for example, lock waits caused by row level locking or explicit lock commands)】
群集類:Cluster
此類等待事件和真正應用群集RAC的資源有關。(比如:gc cr block busy等待事件)【Waits related to Real Application Cluster resources (for example, global cache resources such as 'gc cr block busy'】
送出确認類:Commit
此類等待事件隻包含一種等待事件--在執行了一個commit指令後,等待一個重做日志寫确認(也就是log file sync)【This wait class only comprises one wait event - wait for redo log write confirmation after a commit (that is, 'log file sync')】
并發類:Concurrency
此類等待事件是由内部資料庫資源引起的,比如闩鎖。【Waits for internal database resources (for example, latches)】
配置類:Configuration
此類等待事件是由資料庫或執行個體的不當配置造成的,比如,重做日志檔案尺寸太小,共享池的大小等。【Waits caused by inadequate configuration of database or instance resources (for example, undersized log file sizes, shared pool size)】
空閑類:Idle
此類等待事件意味着會話不活躍,等待工作。比如,sql * net messages from client。【Waits that signify the session is inactive, waiting for work (for example, 'SQL*Net message from client')】
網絡類:Network
和網絡環境相關的一些等待事件,比如sql* net more data to dblink。【Waits related to network messaging (for example, 'SQL*Net more data to dblink')】
其它類:Other
此類等待事件通常比較少見。【Waits which should not typically occur on a system (for example, 'wait for EMON to spawn')】
排程類:Scheduler
Resource Manager related waits (for example, 'resmgr: become active')
系統I/O類:System I/O
此類等待事件通過是由背景程序的I/O操作引起的,比如DBWR等待,db file paralle write。【Waits for background process IO (for example, DBWR wait for 'db file parallel write')】
使用者I/O類:User I/O
此類等待事件通常是由使用者I/O操作引起的,比如db file sequential read。【Waits for user IO (for example 'db file sequential read')】