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

Get Fabric certified for FREE! Don't miss your chance! Learn more

Reply
Anonymous
Not applicable

Aggregating a table in Power Query

I have a table that has over 15 million records. When I use Group by feature or do List.Sum function, it takes forever to calculate it. Doing the same in Dataflow just crashes it.

What would be the most effecient way of summing a column in this table or counting rows in the table without using list.sum or related functions?

 

Thanks

3 REPLIES 3
Anonymous
Not applicable

Could we take a peek at your code, and maybe some sample data please?

Anonymous
Not applicable

List.Sum is pretty straightforward, what do these 15M rows look like, and what is the source?

Anonymous
Not applicable

source is sql. 

There's only 4-5 columns. 3 descriptive, 1 date and 1 $ amount. 

I've tried group by in data flow and it takes a lot of time and then it crashes.

on the desktop it takes half hour just to do sum or distinct count of rows.

List.Sum seems straightforward but not sure why it would be such a resource constraint. 

Helpful resources

Announcements
Join our Fabric User Panel

Join our Fabric User Panel

Share feedback directly with Fabric product managers, participate in targeted research studies and influence the Fabric roadmap.

February Power BI Update Carousel

Power BI Monthly Update - February 2026

Check out the February 2026 Power BI update to learn about new features.

FabCon Atlanta 2026 carousel

FabCon Atlanta 2026

Join us at FabCon Atlanta, March 16-20, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.