DBA_HIST_SYSMETRIC_SUMMARY

DBA_HIST_SYSMETRIC_SUMMARY displays a history of statistical summary of all metric values in the System Metrics Long Duration group. This view contains snapshots of V$SYSMETRIC_SUMMARY.

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
`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
`METRIC_UNIT`	`VARCHAR2(64)`	`NOT NULL`	Unit of measurement
`NUM_INTERVAL`	`NUMBER`	`NOT NULL`	Number of intervals observed
`MINVAL`	`NUMBER`	`NOT NULL`	Minimum value observed
`MAXVAL`	`NUMBER`	`NOT NULL`	Maximum value observed
`AVERAGE`	`NUMBER`	`NOT NULL`	Average over the period
`STANDARD_DEVIATION`	`NUMBER`	`NOT NULL`	One standard deviation
`SUM_SQUARES`	`NUMBER`		???