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

Enhance your career with this limited time 50% discount on Fabric and Power BI exams. Ends August 31st. Request your voucher.

Reply
shep
New Member

Optimize Append Query of Two Other Query Results in Excel Power Query

I have the queries working but noticed that some of the performance is slow and it looks like it's because PowerQuery is rebuilding all of the intermediate steps when I append them rather than using the results from the previous query. This ends up just about doubling the refresh time because it is reprocessing everything.

 

Scenario, refresh all:

1. read multiple files from folder > Combine Query_Temp_A1 > process data > Final_A

2. read multiple files from folder > Combine Query_Temp_B1 > process data > Final_B

3. append query (sources Final_A and FinalB) > read multiple files from folder > Combine Query_Temp_A1 > process data > Final_A > rows from Final_A added to new result > read multiple files from folder > Combine Query_Temp_B1 > process data > Final_B > rows from Final_B added to new result > new result query completed

 

I tried creating a reference of Final_A and Final_B and appending those instead but it didn't change anything. I also tried creating a connection only to Final_A and Final_B but then refresh all doesn't execute the refreshes in the necessary order so the append completes before Final_A and Final_B are done.

 

Do you have any suggestions on how to improve this performance while still ensuring that the data loads in proper sequence?

2 REPLIES 2
spinfuzer
Solution Sage
Solution Sage

Does this link help?

 

https://learn.microsoft.com/en-us/power-query/multiple-queries

 

It talks about why it occurs at the top then talks about how to isolate the multiple queries in the second half.

 

Thanks. There's some good info in there and it gave me some ideas to try. 

Helpful resources

Announcements
July 2025 community update carousel

Fabric Community Update - July 2025

Find out what's new and trending in the Fabric community.

July PBI25 Carousel

Power BI Monthly Update - July 2025

Check out the July 2025 Power BI update to learn about new features.

Join our Fabric User Panel

Join our Fabric User Panel

This is your chance to engage directly with the engineering team behind Fabric and Power BI. Share your experiences and shape the future.

Top Kudoed Authors