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Queue Monitor Auto-Tuning only uses 1 Qmon Worker Process for Persistent Queues (Doc ID 809383.1)

Last updated on AUGUST 30, 2021

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 10.1 to 11.1]
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.
This problem can occur on any platform.


In 10.1 onwards, when using the auto-tuning algorithm of the qmon worker processes, only 1 qmon worker process ever handles persistent queues by default.

This can result in a backlog of PROCESSED messages which are not removed in a timely manner with or without retention being used. In turn this can result in excessive storage consumption.

If enqueue sessions are stopped the PROCESSED messages are removed. In other words the messages are suitable candidates for removal and are just not being removed quickly enough.




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