You are correct that, "I presume that you are thinking of doing it this way because the proc is complex and you do not want to risk affecting any of the other columns' data.

You also mentioned the following: "

But I don't see the point of the temp table. Why not just update Atrn.ABS directly, after running the dodgy proc?" I do not understand what you mean here.

Are you saying that I should create a new stored procedure to run after the 'dodgy proc'?

I am thinking that I should add a new step to the 'dodgy' proc to update the incorrect column value. To calculate the correct value, I need to run a 'long new sql' that has proven to work correctly in ssrs reports.

Thus I thought I would need a new table to obtain this value. If I do not need a new table, can you tell me and/or show me the sql of how I can update the column that needs to be corrected?