Power BI developer mode (tmdl) not updating dataSources.tmdl

[dbeavon3]

I think developer mode is still in "preview". But since TMDL went GA, this may be a fair question.

When does the PBI desktop update the "dataSources.tmdl" file in the semantic model?  I moved an existing model from bim to tmdl and I don't think the PBI desktop knows anything about that particular file.  It is a little bothersome.  When I'm using the desktop, it appears that all of my data sources are hard-coded in the M code (of the particular tables that are defined).  It does NOT appear that the dataSources.tmdl is serving any purpose.

I had once exported a model from the service to tmdl, and noticed the "dataSources.tmdl" was generated at the start.  I had high hopes....  but now it appears to be disregarded by the desktop.

The docs identify it, but I'm guessing the desktop ignores it:
https://learn.microsoft.com/en-us/analysis-services/tmdl/tmdl-overview?view=sql-analysis-services-20...

[v-dineshya · Accepted solution]

HI @dbeavon3 ,

Thank you for reaching out to the Microsoft Community Forum.

Power BI Desktop does not actively use dataSources.tmdl for data source management yet. when you convert a model from BIM to TMDL, the Desktop primarily relies on the M queries embedded in the tables for data source definitions. The dataSources.tmdl file is more relevant for Analysis Services and service-side operations, not for Desktop authoring at this point.

When you export from the Service, the TMDL export includes dataSources.tmdl because the service maintains a more structured representation of data sources. Desktop, however, does not currently synchronize changes back to that file.

TMDL is GA for model definition, but Developer Mode is still in preview, and some features like full parity for data source management are not implemented. Desktop essentially ignores dataSources.tmdl and regenerates its own internal representation from the M queries when saving.

Please try below workaround.

If you need consistent data source definitions. Manage them in Power Query within Desktop or use Analysis Services Tabular Editor or Service-side TMDL export/import for more structured control.

I hope this information helps. Please do let us know if you have any further queries.

Regards,

Dinesh