--
-- multi subquery toplevel union queries aims to expand existing subquery pushdown
-- regression tests to cover more cases
-- the tables that are used depends to multi_insert_select_behavioral_analytics_create_table.sql
-- We don't need shard id sequence here, so commented out to prevent conflicts with concurrent tests
-- ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 1400000;
SET citus.enable_router_execution TO false;
-- a very simple union query
SELECT user_id, counter
FROM (
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (1, 2, 3, 4, 5) 
      UNION 
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (5, 6, 7, 8, 9, 10) 
) user_id 
ORDER BY 2 DESC,1
LIMIT 5;
 user_id | counter 
---------+---------
       7 |       9
       8 |       9
      15 |       9
      16 |       9
      20 |       9
(5 rows)

-- the same query with union all
SELECT user_id, counter
FROM (
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (1, 2, 3, 4, 5) 
      UNION ALL
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (5, 6, 7, 8, 9, 10) 
) user_id 
ORDER BY 2 DESC,1
LIMIT 5;
 user_id | counter 
---------+---------
       7 |       9
       7 |       9
       8 |       9
      15 |       9
      15 |       9
(5 rows)

-- the same query with group by
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (1, 2, 3, 4, 5) 
      UNION 
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (5, 6, 7, 8, 9, 10) 
) user_id 
GROUP BY 1
ORDER BY 2 DESC,1
LIMIT 5;
 user_id | sum 
---------+-----
      49 |  22
      15 |  19
      26 |  17
      48 |  17
      61 |  17
(5 rows)

-- the same query with UNION ALL clause
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (1, 2, 3, 4, 5) 
      UNION ALL
    SELECT user_id, value_2 % 10 AS counter FROM events_table WHERE event_type IN (5, 6, 7, 8, 9, 10) 
) user_id 
GROUP BY 1
ORDER BY 2 DESC,1
LIMIT 5;
 user_id | sum 
---------+-----
      48 |  35
      61 |  30
      15 |  28
      49 |  25
      80 |  24
(5 rows)

-- the same query target list entries shuffled
SELECT user_id, sum(counter) 
FROM (
    SELECT value_2 % 10 AS counter, user_id FROM events_table WHERE event_type IN (1, 2, 3, 4, 5) 
      UNION 
    SELECT value_2 % 10 AS counter, user_id FROM events_table WHERE event_type IN (5, 6, 7, 8, 9, 10) 
) user_id 
GROUP BY 1
ORDER BY 2 DESC,1
LIMIT 5;
 user_id | sum 
---------+-----
      49 |  22
      15 |  19
      26 |  17
      48 |  17
      61 |  17
(5 rows)

-- same query with GROUP BY
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, value_2 AS counter FROM events_table WHERE event_type IN (1, 2) 
      UNION 
    SELECT user_id, value_2 AS counter FROM events_table WHERE event_type IN (5, 6) 
) user_id 
GROUP BY 
  user_id 
--HAVING sum(counter) > 900 
ORDER BY 1,2 DESC LIMIT 5;
 user_id | sum  
---------+------
       1 |  518
       2 |  637
       4 |  343
       6 |  354
       7 | 1374
(5 rows)

-- the same query target list entries shuffled but this time the subqueries target list
-- is shuffled
SELECT user_id, sum(counter) 
FROM (
    SELECT value_2 AS counter, user_id FROM events_table WHERE event_type IN (1, 2) 
      UNION 
    SELECT value_2 AS counter, user_id FROM events_table WHERE event_type IN (5, 6) 
) user_id 
GROUP BY 
  user_id 
--HAVING sum(counter) > 900 
ORDER BY 1,2 DESC LIMIT 5;
 user_id | sum  
---------+------
       1 |  518
       2 |  637
       4 |  343
       6 |  354
       7 | 1374
(5 rows)

-- similar query this time more subqueries and target list contains a resjunk entry
SELECT sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 20 GROUP BY user_id HAVING sum(value_2) > 500
      UNION 
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 40 and value_1 < 60 GROUP BY user_id HAVING sum(value_2) > 500
      UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 60 and value_1 < 80 GROUP BY user_id HAVING sum(value_2) > 500
        UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 80 and value_1 < 100 GROUP BY user_id HAVING sum(value_2) > 500
        UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 100 and value_1 < 120 GROUP BY user_id HAVING sum(value_2) > 500
) user_id 
GROUP BY user_id ORDER BY 1 DESC LIMIT 5;
  sum  
-------
 27772
 25720
 24993
 24968
 23508
(5 rows)

-- similar query as above, with UNION ALL
SELECT sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 20 GROUP BY user_id HAVING sum(value_2) > 5000
      UNION ALL
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 40 and value_1 < 60 GROUP BY user_id HAVING sum(value_2) > 500
      UNION ALL
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 60 and value_1 < 80 GROUP BY user_id HAVING sum(value_2) > 500
        UNION ALL
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 80 and value_1 < 100 GROUP BY user_id HAVING sum(value_2) > 500
        UNION ALL
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 100 and value_1 < 120 GROUP BY user_id HAVING sum(value_2) > 500
) user_id 
GROUP BY user_id ORDER BY 1 DESC LIMIT 5;
  sum  
-------
 27667
 25080
 24814
 24365
 23508
(5 rows)

-- unions within unions
SELECT *
FROM (
        ( SELECT user_id,
                 sum(counter)
         FROM
           (SELECT 
              user_id, sum(value_2) AS counter
            FROM 
              users_table
            GROUP BY 
              user_id
          UNION 
            SELECT 
              user_id, sum(value_2) AS counter
            FROM 
              events_table
            GROUP BY 
              user_id) user_id_1
         GROUP BY 
          user_id)
      UNION
        (SELECT 
            user_id, sum(counter)
         FROM
           (SELECT 
              user_id, sum(value_2) AS counter
            FROM 
              users_table
            GROUP BY 
              user_id
          UNION 
            SELECT 
              user_id, sum(value_2) AS counter          
            FROM 
              events_table
            GROUP BY 
              user_id) user_id_2
         GROUP BY 
            user_id)) AS ftop 
ORDER BY 2 DESC, 1 DESC 
LIMIT 5;
 user_id |  sum   
---------+--------
      23 | 126017
      45 | 117323
      25 | 116595
      17 | 116520
      90 | 115843
(5 rows)

-- top level unions are wrapped into top level aggregations
SELECT ("final_query"."event_types") as types, count(*) AS sumOfEventType
FROM
  ( SELECT *, random()
   FROM
     ( SELECT "t"."user_id", "t"."time", unnest("t"."collected_events") AS "event_types"
      FROM
        ( SELECT "t1"."user_id", min("t1"."time") AS "time", array_agg(("t1"."event") ORDER BY TIME ASC, event DESC) AS collected_events
         FROM (
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 0 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (10, 11, 12, 13, 14, 15)) events_subquery_1) 
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) ) events_subquery_2)
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) ) events_subquery_3)
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 3 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (26, 27, 28, 29, 30, 13)) events_subquery_4)) t1
         GROUP BY "t1"."user_id") AS t) "q" 
) as final_query
GROUP BY types
ORDER BY types;
 types | sumofeventtype 
-------+----------------
     0 |             55
     1 |             38
     2 |             70
     3 |             58
(4 rows)

-- exactly the same query
-- but wrapper unions are removed from the inner part of the query
SELECT ("final_query"."event_types") as types, count(*) AS sumOfEventType
FROM
  (SELECT *, random()
   FROM
     (SELECT 
        "t"."user_id", "t"."time", unnest("t"."collected_events") AS "event_types"
      FROM
        (SELECT 
            "t1"."user_id", min("t1"."time") AS "time", array_agg(("t1"."event") ORDER BY TIME ASC, event DESC) AS collected_events
         FROM(
                  (SELECT 
                    "events"."user_id", "events"."time", 0 AS event
                   FROM 
                    events_table as  "events"
                   WHERE 
                    event_type IN (10, 11, 12, 13, 14, 15))
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 3 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (26, 27, 28, 29, 30, 13))) t1
         GROUP BY "t1"."user_id") AS t) "q" 
) as final_query
GROUP BY types
ORDER BY types;
 types | sumofeventtype 
-------+----------------
     0 |             55
     1 |             38
     2 |             70
     3 |             58
(4 rows)

-- again excatly the same query with top level wrapper removed
SELECT ("q"."event_types") as types, count(*) AS sumOfEventType
FROM
     ( SELECT "t"."user_id", "t"."time", unnest("t"."collected_events") AS "event_types"
      FROM
        ( SELECT "t1"."user_id", min("t1"."time") AS "time", array_agg(("t1"."event") ORDER BY TIME ASC, event DESC) AS collected_events
         FROM (
                  (SELECT 
                    "events"."user_id", "events"."time", 0 AS event
                   FROM 
                    events_table as  "events"
                   WHERE 
                    event_type IN (10, 11, 12, 13, 14, 15))
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 3 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (26, 27, 28, 29, 30, 13))) t1
         GROUP BY "t1"."user_id") AS t) "q" 
GROUP BY types
ORDER BY types;
 types | sumofeventtype 
-------+----------------
     0 |             55
     1 |             38
     2 |             70
     3 |             58
(4 rows)

-- again same query but with only two top level empty queries (i.e., no group bys)
SELECT *
FROM
     ( SELECT * 
      FROM
        ( SELECT "t1"."user_id"
         FROM (
                  (SELECT 
                    "events"."user_id", "events"."time", 0 AS event
                   FROM 
                    events_table as  "events"
                   WHERE 
                    event_type IN (10, 11, 12, 13, 14, 15))
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) )
               UNION 
                    (SELECT 
                        "events"."user_id", "events"."time", 3 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (26, 27, 28, 29, 30, 13))) t1
        ) AS t) "q" 
ORDER BY 1 
LIMIT 5;
 user_id 
---------
       0
       0
       0
       1
       1
(5 rows)

-- a very similar query UNION ALL
SELECT ("q"."event_types") as types, count(*) AS sumOfEventType
FROM
     ( SELECT "t"."user_id", "t"."time", unnest("t"."collected_events") AS "event_types"
      FROM
        ( SELECT "t1"."user_id", min("t1"."time") AS "time", array_agg(("t1"."event") ORDER BY TIME ASC, event DESC) AS collected_events
         FROM (
                  (SELECT 
                    "events"."user_id", "events"."time", 0 AS event
                   FROM 
                    events_table as  "events"
                   WHERE 
                    event_type IN (10, 11, 12, 13, 14, 15))
               UNION ALL
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) )
               UNION ALL
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) )
               UNION ALL
                    (SELECT 
                        "events"."user_id", "events"."time", 3 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (26, 27, 28, 29, 30, 13))) t1
         GROUP BY "t1"."user_id") AS t) "q" 
GROUP BY types
ORDER BY types;
 types | sumofeventtype 
-------+----------------
     0 |             55
     1 |             38
     2 |             70
     3 |             58
(4 rows)

-- some UNION ALL queries that are going to be pulled up
SELECT 
  count(*)
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT user_id FROM events_table)
) b;
 count 
-------
 20002
(1 row)

-- similar query without top level agg
SELECT 
  user_id
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT user_id FROM events_table)
) b
ORDER BY 1 DESC
LIMIT 5;
 user_id 
---------
     100
     100
     100
     100
     100
(5 rows)

-- similar query with multiple target list entries
SELECT 
  user_id, value_3
FROM 
(
  (SELECT value_3, user_id FROM users_table)
    UNION ALL
  (SELECT value_3, user_id FROM events_table)
) b
ORDER BY 1 DESC, 2 DESC
LIMIT 5;
 user_id | value_3 
---------+---------
     100 |     999
     100 |     997
     100 |     991
     100 |     989
     100 |     988
(5 rows)

-- similar query group by inside the subqueries
SELECT 
  user_id, value_3_sum
FROM 
(
  (SELECT sum(value_3) as value_3_sum, user_id FROM users_table GROUP BY user_id)
    UNION ALL
  (SELECT sum(value_3) as value_3_sum, user_id FROM users_table GROUP BY user_id)
) b
ORDER BY 2 DESC, 1 DESC
LIMIT 5;
 user_id | value_3_sum 
---------+-------------
      10 |       64060
      10 |       64060
      62 |       62445
      62 |       62445
      26 |       60536
(5 rows)

-- similar query top level group by
SELECT 
  user_id, sum(value_3)
FROM 
(
  (SELECT value_3, user_id FROM users_table)
    UNION ALL
  (SELECT value_3, user_id FROM events_table)
) b
GROUP BY 1
ORDER BY 2 DESC, 1 DESC
LIMIT 5;
 user_id |  sum   
---------+--------
      23 | 123923
      25 | 118087
      69 | 115828
      26 | 114705
       3 | 113915
(5 rows)

-- a long set operation list
SELECT 
  user_id, value_3
FROM 
(
  (SELECT value_3, user_id FROM events_table where event_type IN (1, 2, 3, 4, 5))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (6, 7, 8, 9, 10))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (11, 12, 13, 14, 15))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (16, 17, 18, 19, 20))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (21, 22, 23, 24, 25))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (26, 27, 28, 29, 30))
) b
ORDER BY 1 DESC, 2 DESC
LIMIT 5;
 user_id | value_3 
---------+---------
     100 |     951
      99 |     558
      99 |      14
      98 |     987
      98 |     577
(5 rows)

-- no partition key on the top
SELECT 
  max(value_3)
FROM 
(
  (SELECT value_3, user_id FROM events_table where event_type IN (1, 2, 3, 4, 5))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (6, 7, 8, 9, 10))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (11, 12, 13, 14, 15))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (16, 17, 18, 19, 20))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (21, 22, 23, 24, 25))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (26, 27, 28, 29, 30))
) b
GROUP BY user_id
ORDER BY 1 DESC
LIMIT 5;
 max 
-----
 997
 997
 996
 995
 995
(5 rows)

-- now lets also have some unsupported queries
-- group by is not on the partition key
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM events_table GROUP BY user_id
      UNION
    SELECT value_1 as user_id, sum(value_2) AS counter FROM users_table GROUP BY value_1
) user_id 
GROUP BY user_id;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- partition key is not selected
SELECT sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 20 GROUP BY user_id HAVING sum(value_2) > 500
      UNION 
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 40 and value_1 < 60 GROUP BY user_id HAVING sum(value_2) > 500
      UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 60 and value_1 < 80 GROUP BY user_id HAVING sum(value_2) > 500
      UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table where value_1 < 80 and value_1 < 100 GROUP BY user_id HAVING sum(value_2) > 500
      UNION
    SELECT 2 * user_id, sum(value_2) AS counter FROM users_table where value_1 < 100 and value_1 < 120 GROUP BY user_id HAVING sum(value_2) > 500
) user_id 
GROUP BY user_id ORDER BY 1 DESC LIMIT 5;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- excepts within unions are not supported
SELECT * FROM
(
(
  SELECT user_id, sum(counter) 
    FROM (
     SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id
        UNION 
     SELECT user_id, sum(value_2) AS counter FROM events_table GROUP BY user_id
  ) user_id_1
  GROUP BY user_id
) 
UNION
(
  SELECT user_id, sum(counter) 
    FROM (
      SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id
        EXCEPT 
      SELECT user_id, sum(value_2) AS counter FROM events_table GROUP BY user_id
) user_id_2
  GROUP BY user_id)
) as ftop;
ERROR:  cannot push down this subquery
DETAIL:  Intersect and Except are currently unsupported
-- joins inside unions are not supported
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id
      UNION 
    SELECT events_table.user_id, sum(events_table.value_2) AS counter FROM events_table, users_table WHERE users_table.user_id > events_table.user_id GROUP BY 1
) user_id 
GROUP BY user_id;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- joins inside unions are not supported -- slightly more comlex than the above
SELECT * FROM
(
(
  SELECT user_id, sum(counter) 
    FROM (
     SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id
       UNION 
     SELECT user_id, sum(value_2) AS counter FROM events_table GROUP BY user_id
  ) user_id_1
  GROUP BY user_id
) 
UNION
(
  SELECT user_id, sum(counter) 
    FROM (
      SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id
        UNION 
      SELECT events_table.user_id, sum(events_table.value_2) AS counter FROM events_table, users_table WHERE (events_table.user_id = users_table.user_id) GROUP BY events_table.user_id
) user_id_2
  GROUP BY user_id)
) as ftop;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- offset inside the union
SELECT user_id, sum(counter) 
FROM (
    SELECT user_id, sum(value_2) AS counter FROM events_table GROUP BY user_id
      UNION
    SELECT user_id, sum(value_2) AS counter FROM users_table GROUP BY user_id OFFSET 4
) user_id 
GROUP BY user_id;
ERROR:  cannot push down this subquery
DETAIL:  Offset clause is currently unsupported
-- lower level union does not return partition key with the other relations
SELECT *
FROM (
        ( SELECT user_id,
                 sum(counter)
         FROM
           (SELECT 
              user_id, sum(value_2) AS counter
            FROM 
              users_table
            GROUP BY 
              user_id
          UNION 
            SELECT 
              user_id, sum(value_2) AS counter
            FROM 
              events_table
            GROUP BY 
              user_id) user_id_1
         GROUP BY 
          user_id)
      UNION
        (SELECT 
            user_id, sum(counter)
         FROM
           (SELECT 
              sum(value_2) AS counter, user_id
            FROM 
              users_table
            GROUP BY 
              user_id
          UNION 
            SELECT 
              user_id, sum(value_2) AS counter          
            FROM 
              events_table
            GROUP BY 
              user_id) user_id_2
         GROUP BY 
            user_id)) AS ftop;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- some UNION all queries that are going to be pulled up
SELECT 
  count(*)
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT 2 * user_id FROM events_table)
) b;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- last query does not have partition key
SELECT 
  user_id, value_3
FROM 
(
  (SELECT value_3, user_id FROM events_table where event_type IN (1, 2, 3, 4, 5))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (6, 7, 8, 9, 10))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (11, 12, 13, 14, 15))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (16, 17, 18, 19, 20))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (21, 22, 23, 24, 25))
    UNION ALL
  (SELECT value_3, value_2 FROM events_table where event_type IN (26, 27, 28, 29, 30))
) b
ORDER BY 1 DESC, 2 DESC
LIMIT 5;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- we don't allow joins within unions
SELECT 
  count(*)
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT users_table.user_id FROM events_table, users_table WHERE events_table.user_id = users_table.user_id)
) b;
ERROR:  cannot pushdown the subquery since all leaves of the UNION does not include partition key at the same position
DETAIL:  Each leaf query of the UNION should return partition key at the same position on its target list.
-- we don't support subqueries without relations
SELECT 
  count(*)
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT 1)
) b;
ERROR:  cannot push down this subquery
DETAIL:  Subqueries without relations are unsupported
-- we don't support subqueries without relations
SELECT 
  *
FROM 
(
  (SELECT user_id FROM users_table)
    UNION ALL
  (SELECT (random() * 100)::int)
) b;
ERROR:  cannot push down this subquery
DETAIL:  Subqueries without relations are unsupported
-- we don't support subqueries without relations
SELECT 
  user_id, value_3
FROM 
(
  (SELECT value_3, user_id FROM events_table where event_type IN (1, 2, 3, 4, 5))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (6, 7, 8, 9, 10))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (11, 12, 13, 14, 15))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (16, 17, 18, 19, 20))
    UNION ALL
  (SELECT value_3, user_id FROM events_table where event_type IN (21, 22, 23, 24, 25))
    UNION ALL
  (SELECT 1, 2)
) b
ORDER BY 1 DESC, 2 DESC
LIMIT 5;
ERROR:  cannot push down this subquery
DETAIL:  Subqueries without relations are unsupported
SELECT ("final_query"."event_types") as types, count(*) AS sumOfEventType
FROM
  ( SELECT *, random()
   FROM
     ( SELECT "t"."user_id", "t"."time", unnest("t"."collected_events") AS "event_types"
      FROM
        ( SELECT "t1"."user_id", min("t1"."time") AS "time", array_agg(("t1"."event") ORDER BY TIME ASC, event DESC) AS collected_events
         FROM (
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 0 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (10, 11, 12, 13, 14, 15)) events_subquery_1) 
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 1 AS event
                     FROM 
                        events_table as "events"
                     WHERE 
                        event_type IN (15, 16, 17, 18, 19) ) events_subquery_2)
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 
                        "events"."user_id", "events"."time", 2 AS event
                     FROM 
                        events_table as  "events"
                     WHERE 
                        event_type IN (20, 21, 22, 23, 24, 25) ) events_subquery_3)
               UNION 
                 (SELECT *
                  FROM
                    (SELECT 1, now(), 3 AS event) events_subquery_4)) t1
         GROUP BY "t1"."user_id") AS t) "q" 
) as final_query
GROUP BY types
ORDER BY types;
ERROR:  cannot push down this subquery
DETAIL:  Subqueries without relations are unsupported
SET citus.enable_router_execution TO true;