Power Query slow-please help!

[IgorGershenson]

I am using 62-bit version of Excel and 34 GB of RAM but my Power Query still works slowly. Specifically, whenever I try to open my query to edit or add new steps, it appears to be reloading all the data again and takes over 5 min just to open. Any way to speed up this process?  thanks

[HotChilli]

Some general tips:

Investigate storing your source files as csv rather than Excel.

https://blog.crossjoin.co.uk/2018/08/02/comparing-the-performance-of-csv-and-excel-data-sources-in-p...

Investigate turning off Background Data; go to Options > Data Load > Background Data 'Allow data preview to'.

Investigate re-working the Power Query 'recipe' to reduce processing.  This is totally dependent on what the transformations are and what your skill level is.

Investigate reducing transformations in Power Query and doing more with DAX in the front end.  Again depends on the model.

Turn off 'enable load' on any queries where data is not required in the front end

[ImkeF]

Often, this helps as well: https://www.thebiccountant.com/2016/11/08/speed-powerbi-power-query-design-process/