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Why Is My Query Using a High Value for Degree of Parallelism (DOP)? (Doc ID 1684931.1)

Last updated on JANUARY 29, 2022

Applies to:

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
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.

Goal

You want to know why the parallel execution of your SQL statement is using a high value for degree of parallelism (DOP). 

Solution

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In this Document
Goal
Solution
 Factors that may cause a high calculated value of DOP:
 1. Object degree is set to DEFAULT
 2. Parallel hint doesn't specify the DOP to use or parallel hint is invalid
 3. Parameter parallel_degree_policy is set to AUTO or LIMITED (11.2 or higher only)
 4. There are some known bugs
 Other ways to limit DOP
References

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