V$EVENT_NAME WAIT_CLASS 字段描述
C.1 C1Classes of Wait Events 等待事件类别
Every wait event belongs to a class of wait event.
每个等待事件都属于一个等待事件类。
The following list describes each of the wait classes.
下面描述了每个等待类。
Administrative 管理类
Waits resulting from DBA commands that cause users to wait (for example, an index rebuild)
由导致用户等待的 DBA 命令产生的等待(例如，索引重建)
Application 应用程序
Waits resulting from user application code (for example, lock waits caused by row level locking or explicit lock commands)
由用户应用程序代码产生的等待(例如，由行级锁定或显式锁定命令引起的锁等待)
Cluster 集群
Waits related to Oracle Real Application Clusters resources (for example, global cache resources such as ‘gc cr block busy’)
与 Oracle RAC 资源相关的等待(例如，全局缓存资源，如“ gc cr block busy”)
Commit 提交
This wait class only comprises one wait event - wait for redo log write confirmation after a commit (that is, ‘log file sync’)
这个 wait 类只包含一个 wait 事件 —— 在提交后等待重做日志写入确认(即‘log file sync’)
Concurrency 并发性
Waits for internal database resources (for example, latches)
等待内部数据库资源(例如，闩锁latches)
Configuration 配置
Waits caused by inadequate configuration of database or instance resources (for example, undersized log file sizes, shared pool size)
由于数据库或实例资源配置不当(例如，日志文件大小不足、共享池大小不足)引起的等待
Idle 空闲
Waits that signify the session is inactive, waiting for work (for example, ‘SQL*Net message from client’)
表示会话处于非活动状态的等待，等待工作(例如，‘SQL*Net message from client’)
Network 网络
Waits related to network messaging (for example, ‘SQL*Net more data to dblink’)
与网络消息传递相关的等待(例如，“ SQL * Net more data to dblink”)
Other 其他
Waits which should not typically occur on a system (for example, ‘wait for EMON to spawn’)
通常不会在系统上出现的等待(例如，‘wait for EMON to spawn’)
Queueing 排队
Contains events that signify delays in obtaining additional data in a pipelined environment. The time spent on these wait events indicates inefficiency or other problems in the pipeline. It affects features such as parallel queries or PL/SQL packages.DBMS_PIPE
包含表示在流水线环境中获取其他数据方面出现延迟的事件。花在这些等待事件上的时间表明效率低下或管道中存在其他问题。它影响诸如并行查询或 PL/SQL 包DBMS_PIPE
Scheduler 调度
Resource Manager related waits (for example, ‘resmgr: become active’)
与资源管理器相关的等待(例如，‘resmgr: become active’)
System I/O 系统 I/O
Waits for background process I/O (for example, DBWR wait for ‘db file parallel write’)
等待后台进程 I/O (例如，DBWR进程 等待’db file parallel write’DB文件顺序写)
User I/O 用户 I/O
Waits for user I/O (for example ‘db file sequential read’)
等待用户 I/O (例如 'db file sequential read’DB文件顺序读)
