Streams Capture Message Statistics

Description

This metric shows the number of messages captured and the number of messages enqueued by each capture process since the capture process last started.

The Total Messages Captured field shows the total number of redo entries passed by LogMiner to the capture process for detailed rule evaluation. A capture process converts a redo entry into a message and performs detailed rule evaluation on the message when capture process prefiltering cannot discard the redo entry. After detailed rule evaluation, the message is enqueued if it satisfies the capture process rule sets, or the message is discarded if it does not satisfy the capture process rule sets. The Total Messages Enqueued field shows the total number of messages enqueued. The number of captured messages captured can be higher than the number of enqueued messages.

The total messages enqueued includes enqueued logical change records (LCRs) that encapsulate data manipulation language (DML) and data definition language (DDL) changes. The total messages enqueued also includes messages that contain transaction control statements. These messages contain directives such as COMMIT and ROLLBACK. Therefore, the total messages enqueued is higher than the number of row changes and DDL changes enqueued by a capture process.

Related Topics

Streams Capture Process