Oracle教程 2023-02-28

Oracle 视图 DBA_HIST_ENQUEUE_STAT 官方解释，作用，如何使用详细说明

本站中文解释

Oracle 视图 DBA_HIST_ENQUEUE_STAT 是一个查询等待列表数据的动态性能视图，其存储的信息适用于

• 从Oracle 9i数据库开始。
• 仅适用于该版本中包含的每个环境，而不仅仅是内存中的一个
• 动态性能视图在AWR收集插入到统计表之前拉取数据

DBA_HIST_ENQUEUE_STAT 视图可以用来查看当前等待事件的实时统计信息，包括以下信息：

• 从此等待类别中获得的总次数
• 等待时间（即，发生尝试之间的时间差）
• 尝试及失败的次数
• 最小、最大、平均以及标准偏差的等待时间

可以使用以下查询来查看从等待事件获得的信息：

SELECT event_id, wait_class, total_waits, time_waited,
average_wait, min_wait, max_wait, stddev_wait
FROM dba_hist_enqueue_stat
ORDER BY time_waited DESC;

官方英文解释

DBA_HIST_ENQUEUE_STAT displays historical statistics on the number of enqueue (lock) requests for each type of lock.

This view contains snapshots of V$ENQUEUE_STATISTICS.

Column	Datatype	NULL	Description
`SNAP_ID`	`NUMBER`	`NOT NULL`	Unique snapshot ID
`DBID`	`NUMBER`	`NOT NULL`	Database ID for the snapshot
`INSTANCE_NUMBER`	`NUMBER`	`NOT NULL`	Instance number for the snapshot
`EQ_TYPE`	`VARCHAR2(2)`	`NOT NULL`	Type of enqueue requested
`REQ_REASON`	`VARCHAR2(64)`	`NOT NULL`	Reason for the enqueue request
`TOTAL_REQ#`	`NUMBER`		Total number of enqueue requests or enqueue conversions for this type of enqueue
`TOTAL_WAIT#`	`NUMBER`		Total number of times an enqueue request or conversion resulted in a wait
`SUCC_REQ#`	`NUMBER`		Number of times an enqueue request or conversion was granted
`FAILED_REQ#`	`NUMBER`		Number of times an enqueue request or conversion failed
`CUM_WAIT_TIME`	`NUMBER`		Total amount of time (in milliseconds) spent waiting for the enqueue or enqueue conversion
`EVENT#`	`NUMBER`		Event number
`CON_DBID`	`NUMBER`		The database ID of the PDB for the sampled session
`CON_ID`	`NUMBER`		The ID of the container that `CON_DBID` identifies. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data

本站中文解释

官方英文解释

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