Oracle教程 2023-02-24

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

Oracle视图 DBA_HIST_SESSMETRIC_HISTORY 是一个AWR视图，用于收集当前和历史会话的当前指标和性能数据。它统计会话信息，但它不保存任何SQL出现次数，执行时间，语句文本等细节。

使用 Oracle 视图 DBA_HIST_SESSMETRIC_HISTORY 的方法：

1、使用以下表格查询指标历史数据：

SELECT DISTINCT sesmetric_name, instance_number, metric_name
FROM dba_hist_sessmetric_history
ORDER BY sesmetric_name;

2、通过以下表达式查询某个监视器指标的历史数据：

SELECT snap_id, value
FROM dba_hist_sessmetric_history
WHERE sesmetric_name = ‘value’
ORDER BY snap_id
/

DBA_HIST_SESSMETRIC_HISTORY displays the history of several important session metrics.

Note:

This view is populated only if a session metric exceeds a server metric threshold that was configured using the DBMS_SERVER_ALERT package.

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
`BEGIN_TIME`	`DATE`	`NOT NULL`	Begin time of the interval
`END_TIME`	`DATE`	`NOT NULL`	End time of the interval
`SESSID`	`NUMBER`	`NOT NULL`	Session ID
`SERIAL#`	`NUMBER`	`NOT NULL`	Session serial number
`INTSIZE`	`NUMBER`	`NOT NULL`	Interval size (in hundredths of a second)
`GROUP_ID`	`NUMBER`	`NOT NULL`	Group ID
`METRIC_ID`	`NUMBER`	`NOT NULL`	Metric ID
`METRIC_NAME`	`VARCHAR2(64)`	`NOT NULL`	Metric name
`VALUE`	`NUMBER`	`NOT NULL`	Metric Value
`METRIC_UNIT`	`VARCHAR2(64)`	`NOT NULL`	Unit of measurement
`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