Query folding Import mode

[powerbiexpert22]

does query folding happens in case of import mode? if yes then those transformations happens at source or inside power bi memory?

[v-pgoloju]

Hi @powerbiexpert22,

Just following up to see if the response provided was helpful in resolving your issue. Please feel free to let us know if you need any further assistance.

Best regards,

Prasanna Kumar

[v-pgoloju]

Hi @powerbiexpert22,

Thank you for reaching out to the Microsoft Fabric Forum Community, and special thanks to @rohit1991 and @danextian  for prompt and helpful responses.

Just following up to see if the responses provided by community members were helpful in addressing the issue.

If one of the responses helped resolve your query, please consider marking it as the Accepted Solution. Feel free to reach out if you need any further clarification or assistance.

Best regards,
Prasanna Kumar

[danextian · Accepted solution]

Query folding still works in import mode, so it's important to apply foldable steps first. For example, filtering rows and removing columns can be pushed to the source. Do those steps early, before adding any that stop query folding. Power Query will show a warning when a step breaks folding.

[rohit1991]

Hi @powerbiexpert22 

Yes query folding can still happen in Import mode, but only during the initial data load or refresh. If folding is possible, the transformations get pushed to the source system, not Power BI memory.

Once the data is loaded, Power BI stores the result in memory, and transformations don’t fold anymore it’s all in-memory after that. So folding helps optimize the load, not the in-memory model.