Direct Query and Transformations - Better in SQL or Power Query

[Anonymous]

Hi everyone, 

I have a question regarding my Power BI Direct Query Optimization. 

If I have to do transformation to my data (ex : Group by, or Cast , or whatever) is it more efficient to do it in my SQL Query or with Power Query tools ?

Thank you for your answer

Bests, 

Romain

[ImkeF · Accepted solution]

Hi @Anonymous ,

if you can, do your transformations at the source already.