How to make this SQL line more efficient? (Case when in Partition By)

Question

I have a SQL line that looks like this

,SUM(Unit_Retail) OVER (PARTITION BY CASE WHEN @LocalDetailLevel = \'master\' THEN Master_Item WHEN @LocalDetailLevel = \'         


        

Answer 1

From an efficiency perspective,

CASE
    WHEN @LocalDetailLevel = 'master' THEN SUM(Unit_Retail) OVER (PARTITION BY Master_Item)
    WHEN @LocalDetailLevel = 'size' THEN SUM(Unit_Retail) OVER (PARTITION BY Item_Number)
    WHEN @LocalDetailLevel = 'color' THEN CONCAT(Item_Number, Color_Code)
END AS Sum_Unit_Retail

Will you your best bet here. Without knowing the intricacies of your data, this seems to logically take the least amount of operations to complete, which is a good sign from an efficiency perspective.

If you'd like, you could compare it against your current performance by following the steps here.