When you join a table to another table in Power Query, the UI gives you the option to either expand the columns (default) or aggregate the contents of the joint tables. That’s useful if multiple rows are returned for the rows of the table that has been joined to (left table):
If you’re working with large data or complex queries that take a long time refresh, cancelling one of those refreshes can even take longer time, especially, if the query has run for quite some time already.
Luckily, there is an easy trick to cancel refresh without loosing the work you’ve done already:
The function below has just one parameter where you either fill in a full filename (incl. path) of an Excel file, or a folder path where multiple files reside. The function will automatically detect the right modus and spit out the M-code. Read more
When you import Excel sheets who have empty leading or trailing columns and rows (showing null-values), you can substantially improve the complexity and speed of your import process with a simple trick:
Remove the reasons for the empty trailing rows and columns 😉
Usually, when you import data from an Excel sheet, Power Query will automatically detect the used range in a sheet and will just return those rows and columns who have content in it. So how can it come that in some cases, additional rows or columns are returned who have nothing but empty values in them?
The “Inquire” Excel Add-On lets you clean any excess cell formatting. After you’ve executed this command, Power Query will not import any of those leading or trailing empty rows or columns any more. Often this will reduce the file size of the Excel files dramatically as well.
You will benefit from:
simpler query logic
potentially huge improved import speed, due to the reduced file size