text: -- database: presto; groups: tpch; tables: lineitem,part
  SELECT 100.00 * sum(CASE
                      WHEN p_type LIKE 'PROMO%'
                        THEN l_extendedprice * (1 - l_discount)
                      ELSE 0
                      END) / sum(l_extendedprice * (1 - l_discount)) AS promo_revenue
  FROM
    part
  WHERE
    l_partkey = p_partkey
    AND l_shipdate >= DATE '1995-09-01'
    AND l_shipdate < DATE '1995-09-01' + INTERVAL '1' MONTH
  