WITH "t1" AS (
  SELECT
    "t0"."string_col",
    SUM("t0"."double_col") AS "metric"
  FROM "functional_alltypes" AS "t0"
  GROUP BY
    1
)
SELECT
  *
FROM (
  SELECT
    *
  FROM (
    SELECT
      *
    FROM (
      SELECT
        *
      FROM "t1" AS "t2"
      UNION ALL
      SELECT
        *
      FROM "t1" AS "t4"
    ) AS "t5"
  ) AS "t6"
  UNION ALL
  SELECT
    *
  FROM "t1" AS "t3"
) AS "t7"