Date Columns and Query Folding in Power BI

Marc Lelijveld discovered a case where transforming a date+time to a date could potentially break query folding:

While working on projects, It is always my goal to keep query folding active as long as possible. Simply because it improves my dataset refresh timings and reduces the load executed on Power BI side.

While working on a project last week, I found something interesting in default Power BI functionality which breaks query folding, but can be avoided by slightly changing the Power Query code yourself or picking another option which results in exactly the same. So, this week a short blog post to make you aware of things which might brake query folding.

Click through for two scenarios, one where a transformation can break query folding and one where query folding is still fine.

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