Which two statements are true about metrics in the DBMCLI utility? (Choose two.)
A.
Metric values are computed and stored in memory, and then permanently stored on disk.
B.
DBMCLI can be used to report on Exadata storage server metrics.
C.
Metrics are reported as one of four types: cumulative, instantaneous, rate, or transition.
D.
Fields in AlertHistory cannot be modified.
E.
DBMCLI reported metrics are informational only and cannot be used to trigger alerts or reported events.
Explanation:
https://docs.oracle.com/cd/E50790_01/doc/doc.121/e51951/app_dbmcli.htm#DBMMN22246
It seems correct.
Overview of Metrics Monitoring
First, let’s take a look at how the Exadata storage server monitoring works. The primary process that manages Exadata storage servers is CELLSRV. It will periodically record important metrics on components like the CPUs, cell disks, grid disks, flash cache and IORM (IO Resource Management). These metrics are initially stored in memory. The MS (Management Server) retrieves these metrics from CELLSRV and keeps a subset of the values in memory and once an hour writes a history to an internal disk repository. The retention period for these metrics and alert information defaults to seven days and can be controlled by a specific setting on the storage server called metricHistoryDays. It is changed using an ALTER CELL command in CELLCLI on each storage server.
It’s correct