My Oracle Support Banner

Parallel Query Downgraded to Serial When CDB Consumer Group is Enabled in 12c (Doc ID 2048186.1)

Last updated on NOVEMBER 07, 2023

Applies to:

Oracle Database Cloud Service - Version N/A and later
Oracle Database - Enterprise Edition - Version to [Release 12.1]
Oracle Database Cloud Schema Service - Version N/A and later
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
Information in this document applies to any platform.


Parallel query running inside a PDB downgraded to serial
DOP is downgraded to 0 when CDB Consumer Group is enabled and parallel_degree_policy=manual and segment is not in memory.
If the segment is in memory or parallel_degree_policy=adaptive DOP does not get downgraded.
The inconsistent DOP (Degree of Parallelism) when running SQLs with parallel hints when CDB consumer group is enabled.

A snippet of the parallel trace shows that DOP was downgraded to 0 due to 350:



To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.