Query was NOT accelerated

Hello ,

Past 3 days i can’t see mine Query is not accelarting .i am using dremio version 4.1.3-202001022113020736-53142377 ,here is the job profile for that83be3367-9982-4b5f-a8f6-c1590fac682a.zip (3.7 KB)

any update on issues?

LOAD MATERIALIZATION jobs cannot be accelerated since they are loading the reflection data already.

But i did not able to accelate any Query using Reflection all are showing same messages Query can not accelarate

here is other job profile which never accelrated i am also not getting any server error,i have
also triyed disabled and enabled Reflection but same issue 33982398-a420-47ed-ad2d-3520872656d9.zip (163.8 KB)


Your reflection refresh was not accelerated by another reflection as it is not a match. This means “TruckTicketListRecords” does not have all the information to accelerate “0b666150-5300-4cd5-9136-ec10e322f67b”

In that case how I can accelerate any way to disabled enabled or delete old reflection please suggest

Anyway to reset reflection so that it willl create new


Open settings for the dataset, disable reflection-save, again go in enable reflection and save

I have tried like this but still showing not reflected this issue with all dataset either vds or pds non of the query accelerated


Not reflected does not mean the reflection is invalid, in the above case it was not a match, which means the reflection on “TruckTicketListRecords”, does not have all the information needed to accelerate the REFRESH REFLECTION. I saw your visualized plan and it looks very wide so there is a good chance that “TruckTicketListRecords” is unable to substitute. There are many JDBC calls in the refresh reflection, is “TruckTicketListRecords” as dataset that is used in the refresh reflection job?

Hi Balaji Ramaswamy, Thanks for reaching out.
I have tried while disable and unable but not working, in this case, can you please suggest to us which kind of information that we are lacking to accelerate the REFRESH REFLECTION so we can look into those information to gather for REFRESH REFLECTION.
Thanks again related to the feedback of many JDBC calls for refresh reflection, will work on it to reduce.

@balaji.ramaswamy i have triyed like below

  1. disabled reflection on TruckTicketListRecords VDS
  2. Disabled Reflection on FDCWellRecordsView which is actual dataset having more joins query
  3. i have used below query to check EXPLAIN PLAN FOR SELECT * FROM tourmalineqa.Datasets.FDCWellRecordsView
  4. after that i am getting error Failure while attempting substitution, skipping materialization 178d2ba4-1f0c-4adc-a808-4798e0daaceb

then i see reflection accelerating


We are working on fixing the error but for now it should be non impacting and if your query is accelerating, you should use this model and make sure the reflection is in the right state always

Thanks for your help