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Excessive PGA memory usage by the Wnnn Background Process (Doc ID 2685491.1)

Last updated on APRIL 17, 2023

Applies to:

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


Each Wnnn Background Process is consuming around 140MB of pga ( can be more as well) and holding hundreds of opened cursors causing memory usage of instance to go high.
The sessions appear to remain open (session state ACTIVE), holding these cursors.

The Wnnn and SMCo processes appear to remain active for weeks at a time, as we can seen by logon time.

Example pga use of one affected instance:





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