Oracle教程 2023-03-26

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

Oracle视图DBA_HIST_SYSSTAT可以查看在特定时间范围内有关系统统计信息的历史数据。该视图储存多个AWR报告收集的系统统计信息，比如CPU时间，更新的语句数量和逻辑读取次数，等等。

使用视图DBA_HIST_SYSSTAT时，可以针对特定数据库实例检查AWR报告所收集的系统统计信息的特定实例。为此，可以执行带有DBA_HIST_SYSSTAT的SQL查询，查看AWR报表收集的特定信息和时间范围。例如，

SELECT * FROM DBA_HIST_SYSSTAT
WHERE SNAP_ID BETWEEN 1000 AND 2000 AND INSTANCE_NUMBER=1;

该查询将检索在1000到2000之间的快照之间收集的实例1的系统统计信息，包括特定性能指标以及快照时间段内性能指标变化情况。

DBA_HIST_SYSSTAT displays historical system statistics information, including OLAP kernel statistics.

This view contains snapshots of V$SYSSTAT.

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
`STAT_ID`	`NUMBER`	`NOT NULL`	Statistic identifier
`STAT_NAME`	`VARCHAR2(64)`	`NOT NULL`	Statistic name
`VALUE`	`NUMBER`		Statistic value
`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