Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Find everything you need to get certified on Fabric—skills challenges, live sessions, exam prep, role guidance, and more. Get started

Reply
wpf_
Post Prodigy
Post Prodigy

Are M code filtering done in the data source?

If i just want to filter a table in query editor for just active records, is the filtering done in the data source before it sends the data over to BI, or is all the data sent over to BI first, then filtered in BI?

 

I was wondering if the more filtering i do in query editor would slow down my report.  Thanks 

1 ACCEPTED SOLUTION

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.

View solution in original post

4 REPLIES 4
v-stephen-msft
Community Support
Community Support

Hi @wpf_ ,

 

I think this is also related to your connection mode.

If it is the import mode, it will import all data into Power BI. Therefore, if your data is filtered before importing, the performance of the report will be better.

If the connection is DirectQuery. It is a direct connection to data source. Data will NOT be stored in Power BI model. Power BI will be a visualization layer, then query the data from data source every time.

And the last connection mode is Live connection. There's no Power Query in this mode..

 

Reference: DirectQuery, Live Connection or Import Data? Tough Decision!

 

 

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.

@v-stephen-msft 

 

when i filter in power query editor, doesn’t that take resources and time to filter even though it is being done in data source? Or is that still more efficient then bringing all the data over?

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.

jthomson
Solution Sage
Solution Sage

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

Helpful resources

Announcements
July 2024 Power BI Update

Power BI Monthly Update - July 2024

Check out the July 2024 Power BI update to learn about new features.

PBI_Carousel_NL_June

Fabric Community Update - June 2024

Get the latest Fabric updates from Build 2024, key Skills Challenge voucher deadlines, top blogs, forum posts, and product ideas.

Top Solution Authors