9.9 Monitoring Exadata Snapshots Using Database Statistics and Wait Events
The following table describes database specific statistics that are useful
for monitoring Exadata Snapshots. The statistics are
available in various dynamic performance views, including V$SYSSTAT
,
and may be displayed in the Global Activity Statistics or Instance Activity Statistics
section of an AWR report.
Statistic | Description |
---|---|
physical read snap IO requests base |
The number of physical I/Os on the parent or base file. |
physical read snap IO requests copy |
The number of physical I/Os on the snapshot file. |
physical read snap bytes base |
The number of bytes read from the parent or base file |
physical read snap bytes copy |
The number of bytes read from the snapshot file. |
physical read snap IO requests new
allocation |
The number of new allocations on the snapshot file. |
physical read snap IO requests no data |
The number of physical read I/O requests for which no physical I/O is done on the child file level. |
The following table describes specific database wait events that are useful
for monitoring Exadata Snapshots. The wait events are
visible in various dynamic performance views, including V$SESSION
,
V$SYSTEM_EVENT
and V$SESSION_EVENT
, and may be
displayed in the Wait Event sections of the AWR report.
Wait Event | Description |
---|---|
cell physical read no I/O |
The wait event appears when a read is done from a sparse disk group, and did not return any data. |
The availability of a specific statistic or wait event is subject to the version of Oracle Database being used.
Parent topic: Setting up Oracle Exadata Storage Snapshots