Integrating with OneLake

1. ADF pipelines external to Fabric cannot natively access OneLake. This is a current product limitation.
2. Non-AAD authentication methods are not supported. You’ll need to authenticate using a Fabric-enrolled identity (user or service principal) with proper workspace permissions.
3. Folder-based security is not currently supported. Access is governed at the workspace level, and subfolders cannot override or partition permissions independently.  However, with OneLake security currently in private preview and coming out later this year security in Fabric will change A LOT. 
4. Yes, the only supported way to control geographic data residency in OneLake is to purchase Power BI (Fabric) capacity, assign that capacity to a specific Azure data region, and create workspaces bound to those capacities.

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