Forum Discussion
List of M functions that work with Direct Query?
I know there's a list of DAX functions that are supported in Direct Query mode (vs only import mode).
Is there a similar list of M functions?
I keep trying to use some of the functions to make some calculated columns, but as soon as I use some of them, I get the message that it's only supported in Import Mode. It would be nice to know ahead of time what is possible and what is not.
Thanks.
2 Replies
This depends on what data source type you are using, and is a complex question, as generally, Power Bi will try to run to code to fold your query into a native query, but if it fails for whatever reason (not supported, code bug, ect...) it will fall back to importing the data up to that point and do the operations directly, which will break Direct query. For example, a connector (the code behind processing the data source) might support List.Max on number columns, but not text columns.
I'm using SAP Hana.
Would be nice if there were a table then that covered the major sources that allow DQ (there aren't that many) showing which functions worked with which sources.
Of course, I know that's a lot of work. Still if anybody ahs something like that, it would be extremely helpful.
