Oracle uses deferred transactions to propagate data-level changes asynchronously among master sites in an advanced replication system as well as from an updatable snapshot to its master table.
This metric checks for the number of deferred transactions. An alert is generated if the number of deferred transactions exceeds the value specified by the threshold argument.
The rest of the information in this section is only valid for this metric when it appears in either the Enterprise Manager Grid Control or the Enterprise Manager Database Control (if applicable).
The following table shows how often the metric's value is collected and compared against the default thresholds. The 'Consecutive Number of Occurrences Preceding Notification' column indicates the consecutive number of times the comparison against thresholds should hold TRUE before an alert is generated.
|
Target Version |
Evaluation and Collection Frequency |
Upload Frequency |
Operator |
Default Warning Threshold |
Default Critical Threshold |
Consecutive Number of Occurrences Preceding Notification |
Alert Text |
|
All Versions |
Every 5 Minutes |
Not Uploaded |
> |
100 |
Not Defined |
3 |
Number of deferred transactions is %value%. |
SELECT count(*) FROM sys.deftran
When the advanced replication facility pushes a deferred transaction to a remote site, it uses a distributed transaction to ensure that the transaction has been properly committed at the remote site before the transaction is removed for the queue at the local site. If transactions are not being pushed to a given remote site, verify that the destination for the transaction was correctly specified. If you specify a destination database when calling DBMS_DEFER_SYS.SCHEDULE_EXECUTION using the DBLINK parameter or DBMS_DEFER_SYS.EXECUTE using the DESTINATION parameter, make sure the full database link is provided.
Wrong view destinations can lead to erroneous deferred transaction behavior. Verify the DEFCALLEST and DEFTRANDEST views are the definitions from the CATREPC.SQL not the ones from CATDEFER.SQL.
Related Topics
About Alerts
About the Metric Detail Page
Editing Thresholds
Understanding Line Charts
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