New (calculated) column: SQL Query or DAX? (Performance)

[Arklur]

What's the best partice for adding a new (calculated) column to a source? Calculate the column in the SQL Query, or add the column later with DAX?

Let's say I would like to create a new column, which is basically just a flag. If the status of the order is "COMPLETED", then 1, else 0. Should I modify my query and add the column there, or use DAX for it?

[stretcharm]

I've you've got large datasets then it can provide better compression if it's a SQL column/expression over a DAX column.

If you can add as a DAX measure then it's not going store any data and calculated when needed.

However measure cannot be used for slicers.

There is a 3rd option add the Competed state in M (Query editor).  Not sure if this is better or worse than in SQL.

My preference is SQL, M, DAX Measure then DAX calculated column.

I also find SQL is easier to manage change than lots of DAX columns.

Here is an post on the storage.

https://www.sqlbi.com/articles/storage-differences-between-calculated-columns-and-calculated-tables/

And another one which recomends avoiding calculated columns.

https://powerpivotpro.com/2014/10/5-common-mistakes-made-by-self-taught-dax-students/