Oracle教程 2023-03-26

Oracle 视图 V$ENQUEUE_STATISTICS 官方解释，作用，如何使用详细说明

Oracle视图V$ENQUEUE_STATISTICS可用于检索排它锁过去一段时间的统计信息。它的记录显示了排它锁的统计信息，包括共享锁，排他锁，延迟升级锁，以及标识模式锁的数量。

用法:

首先，可以使用如下SQL语句来查询V$ENQUEUE_STATISTICS视图，以检索以下信息：

SELECT * FROM v$enqueue_statistics;

这将检索所有列中的记录，例如总数，成功数，失败数，等待数，用于排他锁请求，共享锁请求，延迟升级锁请求或符合模式锁请求的时间。

另外，也可以使用条件语句，如下例所示，以查找特定类型的数据：

SELECT * FROM v$enqueue_statistics WHERE lock_type = ‘分布式’;

此查询将显示的总数，成功数，失败数，等待数等信息，仅对于请求分布式锁的情况。

V$ENQUEUE_STATISTICS displays statistics on the number of enqueue (lock) requests for each type of lock.

V$ENQUEUE_STATISTICS encompasses V$ENQUEUE_STAT and gives more detailed information (several rows for same enqueues with different reasons).

Column	Datatype	Description
`EQ_NAME`	`VARCHAR2(64)`	Name of the enqueue request
`EQ_TYPE`	`VARCHAR2(2)`	Type of enqueue requested
`REQ_REASON`	`VARCHAR2(64)`	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
`REQ_DESCRIPTION`	`VARCHAR2(4000)`	Description of the enqueue request
`EVENT#`	`NUMBER`	Event number
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. 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