tajo-core-tests/src/test/resources/queries/TestGroupByQuery/testDistinctAggregationWithUnion1.sql

select
  sum(distinct l_orderkey),
  l_linenumber,
  count(distinct l_orderkey),
  count(*) as total
from
  (
    select
      *
    from
      lineitem

    union all

    select
      *
    from
      lineitem
  ) t1
group by
  l_linenumber;