Does query folding change the data source?

[timzedel]

I am new to Power BI and have just started learning about query folding - Microsoft describes it as transformations and edits that you make in Power Query Editor are simultaneously tracked as native queries and pushed back to the original data source server for processing. 

Does that mean for example, if I were to merge two columns together in Power Query, the same transformation is applied in the actual SQL Server database that Power BI is sourcing from? If not, what is this 'data source' that the query folding is being applied to;  is it inside or outside of Power BI? 

[ajinkyacgaikwad]

Please watch this video: https://youtu.be/_8WUVlYGekk

[ppm1]

Power BI is read only, so no changes are made to the source. Query folding is a great feature that reduces refresh time when you load data, by pushing some/most of the work back to the source (e.g., database) so that you only spend time loading the data you need.

Pat

[Idrissshatila · Accepted solution]

Hello @timzedel ,

This Article may help you answer your question https://learn.microsoft.com/en-us/power-query/query-folding-basics

If I answered your question, please mark my post as solution, Appreciate your Kudos 👍

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