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Slow Purge Of Records From DBA_CHANGE_NOTIFICATION_REGS (Doc ID 2919680.1)

Last updated on JUNE 22, 2023

Applies to:

Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.


Client application, such as .Net, register clients to receive notifications upon certain registered queries (CQN). When a client is unreachable, it is considered "dead/inactive", and internal database mechanism (EMON) will purge it eventually from DBA_CHANGE_NOTIFICATION_REGS (sys.reg$), but this clean up may take up to 120 minutes. If there are large number of registered clients, this may lead to some unexpected performance and slower response for certain database tasks, such as the database shutdown that may wait longer in "waiting for EMON termination".



Using Database Change Query Notification (CQN).


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