Oracle 11g wait event

Waiting event category:

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Administrative: Wait for the user to wait for the DBA command execution result (for example, re-indexing)

Waits resulting from DBA commands that cause users to wait (for example, an index rebuild)

Application: Wait for the user application code results (for example, lock wait caused by row-level locks or explicit lock commands)

Waits resulting from user application code (for example, lock waits caused by row level locking or explicit lock commands)

Cluster:Wait related to RAC resources (for example, global cache resource 'gc Cr block busy ')

Waits related to real Application Clusters resources (for example, global cache resources such as 'gc Cr block busy ')

Commit:This type of wait event only contains one type of wait event-wait for redo log confirmation after one commit (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 ')

Concurrency:Wait for internal database resources (for example, latches)

Waits for internal database resources (for example, latches)

Configuration:This wait is caused by insufficient database or instance resources (for example, small log file size and shared pool size)

Waits caused by inadequate configuration of database or instance resources (for example, undersized log file sizes, shared pool size)

Idle:This wait indicates that the session is not active and waits for work (for example, 'SQL * Net message from client ')

Waits that signify the session is inactive, waiting for work (for example, 'SQL * Net message from client ')

Network:Wait related to network packet transmission (for example, 'SQL * Net more data to dblink ')

Waits related to Network Messaging (for example, 'SQL * Net more data to dblink ')

Other:Unusual wait events in the system (for example, 'Wait for emon to spawn ')

Waits which shocould not typically occur on a system (for example, 'Wait for emon to spawn ')

Scheduler:Resource Manager wait (for example, 'resmgr: become active ')

Resource Manager related waits (for example, 'resmgr: become active ')

System I/O:Wait for the background process I/O (for example, dbwr waits for 'db file parallel write ')

Waits for background process I/O (for example, dbwr wait for 'db file parallel write ')

User I/O:Waiting for user I/O (for example, 'db file sequential read ')

Waits for user I/O (for example 'db file sequential read ')

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Wait for event information to query the following three dynamic performance views:

V$SESSION_WAITDisplays the events for which sessions have just completed waiting or are currently waiting. displays the waiting event for the session that has just ended or is waiting.

V$SYSTEM_EVENTDisplays the total number of times all the sessions have waited for the events in that view. displays the total number of waits for events in all sessions in the view.

Event: name of the waiting event;
Total_waits: Total number of event waits; time_waited: total waiting time of the event (unit: 1% seconds)

Average_wait: average wait time of the event (unit: 1% seconds) (time_waited/total_waits );
Total_timeouts: Total number of event wait timeouts

V$SESSION_EVENTIs similarV$SYSTEM_EVENT, But displays all waits for each session. All waits in each session are displayed.