On a database with compat level 160, the default setting for
CE_FEEDBACK => ON
MEMORY_GRANT_FEEDBACK => ON
DOP_FEEDBACK => OFF
I can't find a reason why DOP_FEEDBACK is disabled by default. Does anyone know the answer?
Add a comment
|
1 Answer
The feature has requirements to check before it will work:
- Query Store must be enabled on the database in a read/write state.
- Minimum DOP is 2
- Some notes about query hint compatibility to review. See: https://learn.microsoft.com/en-us/sql/relational-databases/performance/intelligent-query-processing-degree-parallelism-feedback?view=sql-server-ver16
Newly introduced SQL Server features are usually opt-in so that an upgrade from an older version will remain close to the same as before. This allows you to test rather than forcing a surprise change on your application.
While this is a guess on my part, note the careful design of the feature to adjust slowly and drop back to a known stable state if a problem is detected.
