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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. 

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