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

Last updated on JUNE 30, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.1 to 12.1.0.2 [Release 12.1]
Information in this document applies to any platform.

Symptoms

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:

 

Cause

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