Average Minutes Between Checkpoints (ChkpntRate)
The ChkpntRate parameter reports the average number of minutes between checkpoints. The annotation for this parameter reports the number of checkpoint in the polling cycle.
If checkpoints are occurring too frequently then run time performance can be reduced and wait states caused. If checkpoints are too widely spaced in time then recovery time may be increased. Normally checkpoints only happen when a redo log switch occurs or the instance is subjected to a shutdown normal.
This parameter uses the following calculations:
(delta_time / 60) |
prf_background_checkpoints_completed |
This is the average number of minutes between checkpoints.
- A larger value means that dirty buffers stay around longer, but the database spends less time physically writing data to disk
- A smaller value means there are more free buffers, but the database can hit a bottleneck because it spends too much time writing to disk
Recommendations
Tuning this parameter would include possibly changing the size of the REDO logs and looking at the init.ora parameter LOG_CHECKPOINT_INTERVAL.
Thresholds for alarms and warnings
Item | Default threshold | State |
|---|---|---|
Border range | 0-100 | ALARM |
Alarm1 range | 1-20 | WARN |
Alarm2 range | 20-100 | ALARM |
PATROL alarms on checkpoint interval, so when you determine what a reasonable value is for your environment you can change the threshold settings.
BMC PATROL properties
Attribute | Default value |
|---|---|
Application class | ORACLE_PERFORMANCE |
Command type | Not applicable |
Platform | All |
Icon style | Graph |
Unit | Number of minutes |
Border range | 0-100 ALARM |
Alarm1 range | 1-20 WARN |
Alarm2 range | 20-100 ALARM |
Scheduling(poll time) | poll time of collector |
Active at installation | Yes |
Parameter type | Consumer |
Value set by | CollPerformance |
BMC ProactiveNet Performance Management properties
Property | Default value |
|---|---|
| Monitor type | Oracle Database Performance |
| Key Performance Indicator | No |
| Monitor for abnormalities | Yes |
| Graph by default | No |
| Availability | No |
| Response time | No |
| Normal distribution | Yes |
| Statistical | Yes |
Comments
Log in or register to comment.