Dataflow gen2 binding to default data destination

[mike9999]

Hey-

Whenever I configure the "Bind to default data destination" for the output of a dataflow gen2 to the Lakehouse - it attempts to bind internal dataflow functions like "Transform Sample file", "Transform Sample file(2)", etc. Dataflows creates these as placeholders automatically when combining multiple binary files. They are not intended to be kept as bindings/outputs. Is there an easy way to automatically skip these and prevent them from being accidently written to the lakehouses?

I have a lot of output files so it is tedious to disable all the transform sample files regularly. 

Mike

[Jai-Rathinavel · Accepted solution]

Hi @mike9999 

• Currently there are no settings in place to disable Functions or Sample files getting written to the lakehouse / warehouse.
• But it is not necessary to have a Transform file / funtions in the Power Query layer. If you see the Transform file funtions those are all created by Power Query automatically. You can copy the logic of the Transform File function and past it inside your main query logic.
• Once you have copied the logic and fixed your M code. You can delete the transformation functions and sample file associated with it.

Thanks,

Jai Rathinavel

[rohit1991]

Hi @mike9999 ,

This is a common pain point when working with Dataflow Gen2 in Power BI, especially if you’re combining multiple files. “Transform Sample file” queries get created automatically, and binding all outputs to the default data destination tries to include them too.

Unfortunately, there’s currently no automatic built-in setting to skip these system-generated queries when binding outputs. You still have to manually uncheck or disable them from being written to the lakehouse.

Workarounds:

• Naming Convention: As a best practice, always name your “real” output tables with a clear, consistent prefix (e.g., “tbl_” or “df_”). This makes it easier to batch-select only what you want in the list.

• Manual Filtering: When binding, sort or filter by name and deselect any queries that start with “Transform Sample file”.