-- Q6: Forecasting Revenue Change
-- Operators: Scan -> Filter -> Aggregate (single SUM)
SELECT
    SUM(l_extendedprice * l_discount) AS revenue
FROM lineitem
WHERE l_shipdate >= DATE '1994-01-01'
  AND l_shipdate < DATE '1994-01-01' + INTERVAL '1 year'
  AND l_discount BETWEEN 0.06 - 0.01 AND 0.06 + 0.01
  AND l_quantity < 24