text: DROP TABLE IF EXISTS nested;
  
  SET flatten_nested = 0;
  
  CREATE TABLE nested
  (
      col1 Nested(a UInt32, s String),
      col2 Nested(a UInt32, n Nested(s String, b UInt32)),
      col3 Nested(n1 Nested(a UInt32, b UInt32), n2 Nested(s String, t String))
  )
  ENGINE = MergeTree
  ORDER BY tuple()
  SETTINGS min_bytes_for_wide_part = 0;
  
  INSERT INTO nested VALUES ([(1, 'q'), (2, 'w'), (3, 'e')], [(4, [('a', 5), ('s', 6), ('d', 7)])], [([(8, 9), (10, 11)], [('z', 'x'), ('c', 'v')])]);
  INSERT INTO nested VALUES ([(12, 'qq')], [(4, []), (5, [('b', 6), ('n', 7)])], [([], []), ([(44, 55), (66, 77)], [])]);
  
  OPTIMIZE TABLE nested FINAL;
  
  SELECT 'all';
  SELECT * FROM nested;
  SELECT 'col1';
  SELECT col1.a, col1.s FROM nested;
  SELECT 'col2';
  SELECT col2.a, col2.n, col2.n.s, col2.n.b FROM nested;
  SELECT 'col3';
  SELECT col3.n1, col3.n2, col3.n1.a, col3.n1.b, col3.n2.s, col3.n2.t FROM nested;
  
  SELECT 'read files';
  
  SYSTEM DROP MARK CACHE;
  SELECT col1.a FROM nested FORMAT Null;
  
  -- 4 files: (col1.size0, col1.a) x2
  SYSTEM FLUSH LOGS;
  SELECT ProfileEvents.Values[indexOf(ProfileEvents.Names, 'FileOpen')]
  FROM system.query_log
  WHERE (type = 'QueryFinish') AND (lower(query) LIKE lower('SELECT col1.a FROM %nested%'))
      AND event_time > now() - INTERVAL 10 SECOND AND current_database = currentDatabase();
  
  SYSTEM DROP MARK CACHE;
  SELECT col3.n2.s FROM nested FORMAT Null;
  
  -- 6 files: (col3.size0, col3.n2.size1, col3.n2.s) x2
  SYSTEM FLUSH LOGS;
  SELECT ProfileEvents.Values[indexOf(ProfileEvents.Names, 'FileOpen')]
  FROM system.query_log
  WHERE (type = 'QueryFinish') AND (lower(query) LIKE lower('SELECT col3.n2.s FROM %nested%'))
      AND event_time > now() - INTERVAL 10 SECOND AND current_database = currentDatabase();
  
  DROP TABLE nested;
  
  CREATE TABLE nested
  (
      id UInt32,
      col1 Nested(a UInt32, n Nested(s String, b UInt32))
  )
  ENGINE = MergeTree
  ORDER BY id
  SETTINGS min_bytes_for_wide_part = 0;
  
  INSERT INTO nested SELECT number, arrayMap(x -> (x, arrayMap(y -> (toString(y * x), y + x), range(number % 17))), range(number % 19)) FROM numbers(1000000);
  SELECT id % 10, sum(length(col1)), sumArray(arrayMap(x -> length(x), col1.n.b)) FROM nested GROUP BY id % 10;
  
  SELECT arraySum(col1.a), arrayMap(x -> x * x * 2, col1.a) FROM nested ORDER BY id LIMIT 5;
  SELECT untuple(arrayJoin(arrayJoin(col1.n))) FROM nested ORDER BY id LIMIT 10 OFFSET 10;
  
  DROP TABLE nested;
  