Dataflows in Power BI: Overview Part 7 – External CDM Folders

One key aspect of Power BI dataflows is that they store their data in CDM Folders in Azure Data Lake Storage gen2.^[1] When a dataflow is refreshed, the queries that define the dataflow entities are executed, and their results are stored in the underlying CDM Folders in the data lake.

By default the Power BI service hides the details of the underlying storage. Only the Power BI service can write to the CDM folders, and only the Power BI service can read from them.

NARRATOR:

But Matthew knew that there are other options beyond the default…

Because the CDM folder format is an open standard, any service or application can create them. A CDM folder can be produced by Azure Data Factory, Azure Databricks, or any other service that can output text and JSON files. Once the CDM folder exists, we just need to let Power BI know…