Use this Knowledge Script to monitor the extent to which applications exercise the read consistency mechanism to ensure database consistency.
The consistent change ratio is based on the number of database changes and database reads. “Consistent changes” refers to the number of times a consistent Get had to retrieve an old version of a database block because of updates that occurred after the cursor had been opened. When the ratio of consistent changes to consistent Gets exceeds the threshold, the job raises an event. The ratio is recalculated each time the script runs, based on the data collected during that monitoring interval.
The account you use to run this script must have SELECT permissions for the following tables:
V_$SYSSTAT
V_$VERSION
Oracle Database folders. When you drop a script on an Oracle Database folder, a job executes on that database and monitors only that database.
The default interval for this script is Every 1 hour.
Set the following parameters as needed:
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Description |
How to Set It |
|---|---|
|
Oracle Username |
Enter the username that this script needs to access the target databases. If you run this script on more than one database, configure each database with the same username. To use SYSDBA authentication, leave this parameter blank. The default is blank. |
|
Collect data for consistent change ratio? |
Select Yes to collect data for charts and reports. When you enable data collection, the script returns the ratio of consistent changes to consistent gets. The default is unselected. |
|
Raise event if threshold is exceeded? |
Select Yes to raise an event if the consistent change ratio exceeds the threshold you set. The default is Yes. |
|
Threshold - Maximum consistent change ratio (0.0 to 1.0) |
Enter a threshold for the maximum ratio of consistent block changes to consistent block gets during the monitoring interval. The is 0.01. |
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Severity |
Set the event severity level, from 1 to 40, to indicate the importance of the event. The default is 5 (red event indicator). |
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Event severity for internal failure |
Set the event severity level, from 1 to 40, to indicate the importance of the event. The default is 5 (red event indicator). |