This metric shows information about the number of messages enqueued by a capture process. The number of messages enqueued includes logical change records (LCRs) that encapsulate data manipulation language (DML) and data definition language (DDL) changes. The number of messages enqueued also includes messages that contain transaction control statements. These messages contain directives such as COMMIT
and ROLLBACK
. Therefore, the number of messages enqueued is higher than the number of row changes and DDL changes enqueued by a capture process.
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.
Target Version |
Collection Frequency |
All Versions |
Every 5 Minutes |
The TOTAL_MESSAGES_ENQUEUED
column in the following query shows this metric for a capture process:
SELECT CAPTURE_NAME, TOTAL_MESSAGES_CAPTURED, TOTAL_MESSAGES_ENQUEUED FROM V$STREAMS_CAPTURE;
When a capture process is enabled, monitor this metric to ensure that the capture process is enqueuing messages. If you know that there were source database changes that should be captured by the capture process, and the capture process is not capturing these changes, then there might be a problem with the rules used by the capture process.
Related Topics
About Alerts
About the Metric Detail Page
Editing Thresholds
Understanding Line Charts
Streams Capture Process
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