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

July 28 - August 9 | Final Round of the Power BI Dataviz World Championships. This is 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
FabCon and SQLCon Barcelona 2026

FabCon & SQLCon – Barcelona 2026

Join us in Barcelona for FabCon and SQLCon, the Fabric, Power BI, SQL, and AI community event. Save €200 with code FABCMTY200.

Fabric Community Sticker Design Challenge Barcelona Carousel

Fabric Community Sticker Challenge - Barcelona 2026

If you love stickers, then you will definitely want to check out our community sticker challenge, Barcelona edition!

July Power BI Update Carousel

Power BI Monthly Update - July 2026

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

Power BI DataViz World Championships carousel

Power BI DataViz World Championships - June 2026

A new Power BI DataViz World Championship is coming this June! Don't miss out on submitting your entry.