text: -- database: presto; groups: tpch; tables: customer,orders,lineitem,nation
  SELECT
    c_custkey,
    c_name,
    sum(l_extendedprice * (1 - l_discount)) AS revenue,
    c_acctbal,
    n_name,
    c_address,
    c_phone,
    c_comment
  FROM
    customer,
    orders,
    lineitem,
    nation
  WHERE
    c_custkey = o_custkey
    AND l_orderkey = o_orderkey
    AND o_orderdate >= '1993-10-01'
    AND o_orderdate < '1994-01-01'
    AND l_returnflag = 'R'
    AND c_nationkey = n_nationkey
  GROUP BY
    c_custkey,
    c_name,
    c_acctbal,
    c_phone,
    n_name,
    c_address,
    c_comment
  ORDER BY
    revenue DESC
  LIMIT 20
  