text: -- database: presto; tables: nation, workers; groups: set_operation;
  -- delimiter: |; ignoreOrder: true;
  --! name: intersect_and_union
  SELECT n_name FROM nation WHERE n_nationkey = 17 
  INTERSECT 
  SELECT n_name FROM nation WHERE n_regionkey = 1 
  UNION 
  SELECT n_name FROM nation WHERE n_regionkey = 2
  --!
  INDIA|
  INDONESIA|
  CHINA|
  JAPAN|
  VIETNAM|
  PERU|
  --! name: intersect_null
  SELECT id_employee
  FROM workers
  INTERSECT
  SELECT department
  FROM workers
  --!
  null|
  9|
  4|
  7|
  2|
  5|
  8|
  