Forum Discussion
Are M code filtering done in the data source?
Hi wpf_ ,
When you filter in power query editor, it takes time and resources to filter.
It's always recommended to filter your data in the early stages of your query or as early as possible. Some connectors will take advantage of your filters through query folding, as described in Power Query query folding. It's also a best practice to filter out any data that isn't relevant for your case. This will let you better focus on your task at hand by only showing data that’s relevant in the data preview section.
We recommend that you strive to achieve efficiency in your model designs by ensuring query folding occurs whenever possible.
Best Regards,
Stephen Tao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
I think where the filtering is done depends on the type of data source you're using, and whether the manipulations you're doing support query folding.
In terms of whether it'd slow down the report, I can't see how that'd ever be the case