In terms of order, it's not clear that the order by happens "after" the where clause, for instance, what if the results are pre-ordered? If the index used guarantees an order, and that order is the same as your order by, it is redundant and no ordering will need to occur.
However, I agree with the thrust of your statement, and if you cant figure out SQL's query plans, writing your own from scratch may be a tall order.
However, I agree with the thrust of your statement, and if you cant figure out SQL's query plans, writing your own from scratch may be a tall order.