You did get it right, but you can also do a preceding load on a preceding load for a better performance increase especially when using mapping tables. You won't see much of a performance gain if you aren't performing an expression in your load. Take the following example:
SQL SELECT * FROM Products;
LOAD LineSalesAmount - CostOfGoodsSold AS Margin,
LineSalesAmount - CostOfGoodsSold AS Margin,
UnitPrice * Quantity * (1 - Discount) AS LineSalesAmount,
applymap('UnitCost_Map', ProductID, 0) * Quantity AS CostOfGoodsSold;
Thanks, Nick - I almost put a note in my original post that I was assuming that there would be additional preceding loads, and that there would be aliases, expressions, etc....I just kept it very simple!