Direct Lake Composite Mode

Hi jaryszek ,

Thanks for getting back.

You are correct - at the moment, when working with Direct Lake + Import composite models, you cannot edit Import tables directly in Power BI Desktop. Adding and managing those tables is only possible through external tools such as Tabular Editor, Fabric Studio, or Semantic Link Labs. Since this feature is still in preview, it is expected that more direct editing support will come once it reaches general availability.

The purpose of having Import tables alongside Direct Lake tables is to give flexibility in your design. Direct Lake is best for very large fact tables because it provides performance without loading data into Vertipaq, but it has limitations such as no calculated columns or Power Query shaping. Import tables, on the other hand, let you include smaller dimension or lookup tables from other sources and extend them with additional modeling features like hierarchies, calculated columns, or custom structures.

From a design point of view, the difference is that you can mix storage modes to balance performance and modeling flexibility. Direct Lake handles scale and speed for large fact data, while Import tables give you the ability to enrich the model with smaller, more structured data.

Hope this helps. Please reach out for further assistance.

Thank you.