Issues when applying query changes and loading applied steps

[Eve]

Hi all,

I recently started with Excel Power Query, but I am stuck...

When I am adding a new step, it takes ages for Excel to load or to execute the step (for each new step/change it takes approx 10min). For example adding a column, changing the type... Excel Power Query gets the data from a folder. Each document in this folder exists of maximum 500 rows. Currently there are only two Excel Files in this Folder. I don't understand why it takes so long.

In the right corner at the bottom of my screen, I can see that Excel is appling the steps to hundreds of thousands of rows. I think something is wrong with the settings, but I don't know how to change it or how I can limit the number of rows, where he has to get the data from.

Can someone help me out?

Thanks in advance!

[v-shex-msft]

HI @Eve,

Any advanced operate on your queries? (e.g. append, combine, merge, invoke custom function, reference another query) 

If this is a case, these operations will cause the duplicate cost when you apply change.(it will cached and calculated multiplied as 'current row count' times)

For this scenario, you can try to use 'Table.Buffer' or 'List.Buffer' funcitons to cache invoke data to memory to reduce duplicate cost.

Regards,

Xiaoxin Sheng