Fabric None Default Semantic Model. Can you copy across into Power BI Desktop?

[DebbieE]

I made the decision to create a Power BI Semantic Model within Fabric, Direct Lake connection to Delta Parquet files. rather than do Direct Lake connection to a Power BI desktop file.

But Im now thinking, especially with the new TMDL (for semantic models) for PBIP files. I wouldnt mind actually changing up and moving the semantic model into a Desktop file.

The question is. Is this doable. How would you go about it?

thanks in advance

[frithjof_v · Accepted solution]

In that case, Power BI desktop is actually using a Live connection to the direct lake semantic model which is created and hosted in the Fabric workspace. The semantic model is not created in Power BI desktop, it is just a live connection to the direct lake semantic model which is created and hosted in the Fabric workspace. When you interact with the visuals and data in Power BI desktop, Direct Lake queries are sent to the Lakehouse Delta tables in the Fabric workspace.

It is not possible to create direct lake semantic models in Power BI desktop, however you can use Power BI desktop to live connect to direct lake semantic models which are created and hosted in the Fabric workspace.

(That is, if something new hasn't happened recently. But I am 95% sure that this is still the case.)

If you instead use Power BI desktop to connect to the SQL (Analytics) Endpoint of the Lakehouse, and choose import mode if asked, then you are creating an import mode (not direct lake) semantic model in Power BI desktop. Then you can pick tables from the Lakehouse, and do transformations in Power Query in Power BI desktop, and create relationships in Power BI desktop. You can publish this semantic model to a Power BI/Fabric workspace as an import mode semantic model.

Please see this blog post:

https://fabric.guru/using-the-lakehouse-connector-in-power-bi-desktop

[DebbieE]

"It is not possible to create direct lake semantic models in Power BI desktop"

So basically. when using Direct lake connection you have to build your Semantic model in Fabric and not in Power BI desktop?

Just had a go at Get Data  > Fabric Data lake and I can see that its actually connected to the default Semantic model as you said.

I tried to originally work with the default semantic model and got error after error and was told it was massively problematic and to create the Semantic Model in Fabric instead of using  the default one. i hope that sorts out in time. 

My other question is. so what is the point of the TMDL in Power BI Project file? If this is for the Semantic model. and you cant create the Semantic model in Power BI desktop?

Unless TMDL is just for Import mode?

[frithjof_v]

Yes, I think if you want to create a  Direct Lake semantic model, you cannot create the semantic model in Power BI desktop but instead you need to create it in the Fabric workspace in the web browser.*

The recommendation is to create a custom semantic model if you want to use direct lake mode, because the default semantic model has many limitations.

https://radacad.com/power-bi-default-semantic-model-or-custom-a-guide-for-using-in-fabric-environmen...

However many (most?) times the good old Import mode will probably be the best option: https://www.sqlbi.com/blog/marco/2024/04/06/direct-lake-vs-import-mode-in-power-bi/

*Maybe there are some other options, like Tabular Editor, Semantic link, etc. 

I don't have the full overview/haven't tried all of them. But I'm pretty sure you can't do it in Power BI desktop at the moment.

[frithjof_v]

I think you will need to connect to SQL Endpoint (now called SQL Analytics Endpoint) from Power BI Desktop, and then choose the tables you want to include, and select import mode (or direct query mode. Import mode is usually the recommended mode.)

https://fabric.guru/using-the-lakehouse-connector-in-power-bi-desktop

Otherwise, maybe it's possible to convert a direct lake semantic model to an import mode semantic model using code: https://github.com/microsoft/semantic-link-labs/?tab=readme-ov-file

But the examples I have seen are usually converting import mode semantic models to direct lake semantic models. Not the other way around.

I think import mode (aka Power BI Desktop semantic model) is usually a good choice 👍

[DebbieE]

I think Im confused with this. You can still use Direct lake mode to Delta Parquet even if you create the semantic model in Power BI desktop.