Which one best approach loading data

Hey,

I'm not 100% sure if I understand your question correctly.

Basically there are three options

1. Create all the necessary column in the source system, eg. using a view in SQL Server
2. Create additional columns in Power Query
3. Create additional column using DAX creating calculated columns.

Basically it depends whats better, from my point of view I would prefer 1, but sometimes calculations are more complex and can be executed faster in M or DAX.

The memory footprint of a calculated column created using M is considered smaller than the column created using DAX, but this is just a fraction, that I always neglect. As I'm more proficient using DAX, I'm using DAX to create calculated columns, I never noticed a performance difference between both types of columns the ones that I created using Power Query or DAX.

I always avoid to spread the column creation across all 3 possibilities, this is due to the spread of complexity. I always tend to look for my mistakes at one place-

For this reason, a personal one, it's 1 or 3-

Hopefully this provides some insight to your thinking.

Regards,

Tom