Clarification on overwriting in Unity Catalog

[himoshi]

Hello, 

While reviewing Unity Catalog to better understand its limitations, I came across the following statement:

• Overwrite mode for DataFrame write operations into Unity Catalog is supported only for Delta tables, not for other file formats. The user must have the CREATE privilege on the parent schema and must be the owner of the existing object or have the MODIFY privilege on the object.

I tested various overwrite scenarios with external tables in different formats but did not encounter any specific limitations. Does this limitation apply only to managed tables? If not, could you provide specific instances where this limitation affects external tables?

Thank you.