--
-- UNION (also INTERSECT, EXCEPT)
--
-- Simple UNION constructs
SELECT 1 AS two UNION SELECT 2;
 two 
-----
   1
   2
(2 rows)

SELECT 1 AS one UNION SELECT 1;
 one 
-----
   1
(1 row)

SELECT 1 AS two UNION ALL SELECT 2;
 two 
-----
   1
   2
(2 rows)

SELECT 1 AS two UNION ALL SELECT 1;
 two 
-----
   1
   1
(2 rows)

SELECT 1 AS three UNION SELECT 2 UNION SELECT 3;
 three 
-------
     1
     2
     3
(3 rows)

SELECT 1 AS two UNION SELECT 2 UNION SELECT 2;
 two 
-----
   1
   2
(2 rows)

SELECT 1 AS three UNION SELECT 2 UNION ALL SELECT 2;
 three 
-------
     1
     2
     2
(3 rows)

SELECT 1.1 AS two UNION SELECT 2.2;
 two 
-----
 1.1
 2.2
(2 rows)

-- Mixed types
SELECT 1.1 AS two UNION SELECT 2;
 two 
-----
 1.1
   2
(2 rows)

SELECT 1 AS two UNION SELECT 2.2;
 two 
-----
   1
 2.2
(2 rows)

SELECT 1 AS one UNION SELECT 1.0::float8;
 one 
-----
   1
(1 row)

SELECT 1.1 AS two UNION ALL SELECT 2;
 two 
-----
 1.1
   2
(2 rows)

SELECT 1.0::float8 AS two UNION ALL SELECT 1;
 two 
-----
   1
   1
(2 rows)

SELECT 1.1 AS three UNION SELECT 2 UNION SELECT 3;
 three 
-------
   1.1
     2
     3
(3 rows)

SELECT 1.1::float8 AS two UNION SELECT 2 UNION SELECT 2.0::float8 ORDER BY 1;
 two 
-----
 1.1
   2
(2 rows)

SELECT 1.1 AS three UNION SELECT 2 UNION ALL SELECT 2;
 three 
-------
   1.1
     2
     2
(3 rows)

SELECT 1.1 AS two UNION (SELECT 2 UNION ALL SELECT 2);
 two 
-----
 1.1
   2
(2 rows)

--
-- Try testing from tables...
--
SELECT f1 AS five FROM FLOAT8_TBL
UNION
SELECT f1 FROM FLOAT8_TBL
ORDER BY 1;
         five          
-----------------------
 -1.2345678901234e+200
               -1004.3
                -34.84
 -1.2345678901234e-200
                     0
(5 rows)

SELECT f1 AS ten FROM FLOAT8_TBL
UNION ALL
SELECT f1 FROM FLOAT8_TBL;
          ten          
-----------------------
                     0
                -34.84
               -1004.3
 -1.2345678901234e+200
 -1.2345678901234e-200
                     0
                -34.84
               -1004.3
 -1.2345678901234e+200
 -1.2345678901234e-200
(10 rows)

SELECT f1 AS nine FROM FLOAT8_TBL
UNION
SELECT f1 FROM INT4_TBL
ORDER BY 1;
         nine          
-----------------------
 -1.2345678901234e+200
           -2147483647
               -123456
               -1004.3
                -34.84
 -1.2345678901234e-200
                     0
                123456
            2147483647
(9 rows)

SELECT f1 AS ten FROM FLOAT8_TBL
UNION ALL
SELECT f1 FROM INT4_TBL;
          ten          
-----------------------
                     0
                -34.84
               -1004.3
 -1.2345678901234e+200
 -1.2345678901234e-200
                     0
                123456
               -123456
            2147483647
           -2147483647
(10 rows)

SELECT f1 AS five FROM FLOAT8_TBL
  WHERE f1 BETWEEN -1e6 AND 1e6
UNION
SELECT f1 FROM INT4_TBL
  WHERE f1 BETWEEN 0 AND 1000000;
         five          
-----------------------
               -1004.3
                -34.84
 -1.2345678901234e-200
                     0
                123456
(5 rows)

SELECT CAST(f1 AS char(4)) AS three FROM VARCHAR_TBL
UNION
SELECT f1 FROM CHAR_TBL
ORDER BY 1;
 three 
-------
 a   
 ab  
 abcd
(3 rows)

SELECT f1 AS three FROM VARCHAR_TBL
UNION
SELECT CAST(f1 AS varchar) FROM CHAR_TBL
ORDER BY 1;
 three 
-------
 a
 ab
 abcd
(3 rows)

SELECT f1 AS eight FROM VARCHAR_TBL
UNION ALL
SELECT f1 FROM CHAR_TBL;
 eight 
-------
 a
 ab
 abcd
 abcd
 a
 ab
 abcd
 abcd
(8 rows)

SELECT f1 AS five FROM TEXT_TBL
UNION
SELECT f1 FROM VARCHAR_TBL
UNION
SELECT TRIM(TRAILING FROM f1) FROM CHAR_TBL
ORDER BY 1;
       five        
-------------------
 a
 ab
 abcd
 doh!
 hi de ho neighbor
(5 rows)

--
-- INTERSECT and EXCEPT
--
SELECT q2 FROM int8_tbl INTERSECT SELECT q1 FROM int8_tbl;
        q2        
------------------
 4567890123456789
              123
(2 rows)

SELECT q2 FROM int8_tbl INTERSECT ALL SELECT q1 FROM int8_tbl;
        q2        
------------------
 4567890123456789
 4567890123456789
              123
(3 rows)

SELECT q2 FROM int8_tbl EXCEPT SELECT q1 FROM int8_tbl ORDER BY 1;
        q2         
-------------------
 -4567890123456789
               456
(2 rows)

SELECT q2 FROM int8_tbl EXCEPT ALL SELECT q1 FROM int8_tbl ORDER BY 1;
        q2         
-------------------
 -4567890123456789
               456
(2 rows)

SELECT q2 FROM int8_tbl EXCEPT ALL SELECT DISTINCT q1 FROM int8_tbl ORDER BY 1;
        q2         
-------------------
 -4567890123456789
               456
  4567890123456789
(3 rows)

SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl;
 q1 
----
(0 rows)

SELECT q1 FROM int8_tbl EXCEPT ALL SELECT q2 FROM int8_tbl;
        q1        
------------------
 4567890123456789
              123
(2 rows)

SELECT q1 FROM int8_tbl EXCEPT ALL SELECT DISTINCT q2 FROM int8_tbl;
        q1        
------------------
 4567890123456789
 4567890123456789
              123
(3 rows)

SELECT q1 FROM int8_tbl EXCEPT ALL SELECT q1 FROM int8_tbl FOR NO KEY UPDATE;
ERROR:  FOR NO KEY UPDATE is not allowed with UNION/INTERSECT/EXCEPT
--
-- Mixed types
--
SELECT f1 FROM float8_tbl INTERSECT SELECT f1 FROM int4_tbl;
 f1 
----
  0
(1 row)

SELECT f1 FROM float8_tbl EXCEPT SELECT f1 FROM int4_tbl ORDER BY 1;
          f1           
-----------------------
 -1.2345678901234e+200
               -1004.3
                -34.84
 -1.2345678901234e-200
(4 rows)

--
-- Operator precedence and (((((extra))))) parentheses
--
SELECT q1 FROM int8_tbl INTERSECT SELECT q2 FROM int8_tbl UNION ALL SELECT q2 FROM int8_tbl;
        q1         
-------------------
  4567890123456789
               123
               456
  4567890123456789
               123
  4567890123456789
 -4567890123456789
(7 rows)

SELECT q1 FROM int8_tbl INTERSECT (((SELECT q2 FROM int8_tbl UNION ALL SELECT q2 FROM int8_tbl)));
        q1        
------------------
 4567890123456789
              123
(2 rows)

(((SELECT q1 FROM int8_tbl INTERSECT SELECT q2 FROM int8_tbl))) UNION ALL SELECT q2 FROM int8_tbl;
        q1         
-------------------
  4567890123456789
               123
               456
  4567890123456789
               123
  4567890123456789
 -4567890123456789
(7 rows)

SELECT q1 FROM int8_tbl UNION ALL SELECT q2 FROM int8_tbl EXCEPT SELECT q1 FROM int8_tbl ORDER BY 1;
        q1         
-------------------
 -4567890123456789
               456
(2 rows)

SELECT q1 FROM int8_tbl UNION ALL (((SELECT q2 FROM int8_tbl EXCEPT SELECT q1 FROM int8_tbl ORDER BY 1))); --order none
        q1         
-------------------
               123
               123
  4567890123456789
  4567890123456789
  4567890123456789
 -4567890123456789
               456
(7 rows)

(((SELECT q1 FROM int8_tbl UNION ALL SELECT q2 FROM int8_tbl))) EXCEPT SELECT q1 FROM int8_tbl ORDER BY 1;
        q1         
-------------------
 -4567890123456789
               456
(2 rows)

--
-- Subqueries with ORDER BY & LIMIT clauses
--
-- In this syntax, ORDER BY/LIMIT apply to the result of the EXCEPT
SELECT q1,q2 FROM int8_tbl EXCEPT SELECT q2,q1 FROM int8_tbl
ORDER BY q2,q1;
        q1        |        q2         
------------------+-------------------
 4567890123456789 | -4567890123456789
              123 |               456
(2 rows)

-- This should fail, because q2 isn't a name of an EXCEPT output column
SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1;
ERROR:  column "q2" does not exist
LINE 1: ... int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1...
                                                             ^
HINT:  There is a column named "q2" in table "*SELECT* 2", but it cannot be referenced from this part of the query.
-- But this should work:
SELECT q1 FROM int8_tbl EXCEPT (((SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1))) ORDER BY 1;
        q1        
------------------
              123
 4567890123456789
(2 rows)

--
-- New syntaxes (7.1) permit new tests
--
(((((select * from int8_tbl)))));
        q1        |        q2         
------------------+-------------------
              123 |               456
              123 |  4567890123456789
 4567890123456789 |               123
 4567890123456789 |  4567890123456789
 4567890123456789 | -4567890123456789
(5 rows)

--
-- Check handling of a case with unknown constants.  We don't guarantee
-- an undecorated constant will work in all cases, but historically this
-- usage has worked, so test we don't break it.
--
SELECT a.f1 FROM (SELECT 'test' AS f1 FROM varchar_tbl) a
UNION
SELECT b.f1 FROM (SELECT f1 FROM varchar_tbl) b
ORDER BY 1;
  f1  
------
 a
 ab
 abcd
 test
(4 rows)

-- This should fail, but it should produce an error cursor
SELECT '3.4'::numeric UNION SELECT 'foo';
ERROR:  invalid input syntax for type numeric: "foo"
LINE 1: SELECT '3.4'::numeric UNION SELECT 'foo';
                                           ^
--
-- Test that expression-index constraints can be pushed down through
-- UNION or UNION ALL
--
CREATE TEMP TABLE t1 (a text, b text);
CREATE INDEX t1_ab_idx on t1 ((a || b));
CREATE TEMP TABLE t2 (ab text primary key);
INSERT INTO t1 VALUES ('a', 'b'), ('x', 'y');
INSERT INTO t2 VALUES ('ab'), ('xy');
set enable_seqscan = off;
set enable_indexscan = on;
set enable_bitmapscan = off;
explain (costs off)
 SELECT * FROM
 (SELECT a || b AS ab FROM t1
  UNION ALL
  SELECT * FROM t2) t
 WHERE ab = 'ab';
                    QUERY PLAN                     
---------------------------------------------------
 Gather Motion 3:1  (slice1; segments: 3)
   ->  Append
         ->  Index Scan using t1_ab_idx on t1
               Index Cond: ((a || b) = 'ab'::text)
         ->  Index Only Scan using t2_pkey on t2
               Index Cond: (ab = 'ab'::text)
 Optimizer: Postgres query optimizer
(7 rows)

explain (costs off)
 SELECT * FROM
 (SELECT a || b AS ab FROM t1
  UNION
  SELECT * FROM t2) t
 WHERE ab = 'ab';
                             QUERY PLAN                              
---------------------------------------------------------------------
 Gather Motion 3:1  (slice2; segments: 3)
   ->  Unique
         Group Key: ((t1.a || t1.b))
         ->  Sort
               Sort Key (Distinct): ((t1.a || t1.b))
               ->  Redistribute Motion 3:3  (slice1; segments: 3)
                     Hash Key: ((t1.a || t1.b))
                     ->  Append
                           ->  Index Scan using t1_ab_idx on t1
                                 Index Cond: ((a || b) = 'ab'::text)
                           ->  Index Only Scan using t2_pkey on t2
                                 Index Cond: (ab = 'ab'::text)
 Optimizer: Postgres query optimizer
(13 rows)

--
-- Test that ORDER BY for UNION ALL can be pushed down to inheritance
-- children.
--
CREATE TEMP TABLE t1c (b text, a text);
ALTER TABLE t1c INHERIT t1;
CREATE TEMP TABLE t2c (primary key (ab)) INHERITS (t2);
INSERT INTO t1c VALUES ('v', 'w'), ('c', 'd'), ('m', 'n'), ('e', 'f');
INSERT INTO t2c VALUES ('vw'), ('cd'), ('mn'), ('ef');
CREATE INDEX t1c_ab_idx on t1c ((a || b));
set enable_seqscan = on;
set enable_indexonlyscan = off;
-- NOTE: GPDB planner chooses a seqscan rather than indexscan for t1.
-- This is a side-effect of disabling pull-up for simple union all in GPDB.
explain (costs off)
  SELECT * FROM
  (SELECT a || b AS ab FROM t1
   UNION ALL
   SELECT ab FROM t2) t
  ORDER BY 1 LIMIT 8;
                   QUERY PLAN                   
------------------------------------------------
 Limit
   ->  Gather Motion 3:1  (slice1; segments: 3)
         Merge Key: ((t1.a || t1.b))
         ->  Limit
               ->  Sort
                     Sort Key: ((t1.a || t1.b))
                     ->  Append
                           ->  Seq Scan on t1
                           ->  Seq Scan on t1c
                           ->  Seq Scan on t2
                           ->  Seq Scan on t2c
 Optimizer: Postgres query optimizer
(12 rows)

  SELECT * FROM
  (SELECT a || b AS ab FROM t1
   UNION ALL
   SELECT ab FROM t2) t
  ORDER BY 1 LIMIT 8;
 ab 
----
 ab
 ab
 cd
 dc
 ef
 fe
 mn
 nm
(8 rows)

reset enable_seqscan;
reset enable_indexscan;
reset enable_bitmapscan;
-- This simpler variant of the above test has been observed to fail differently
create table events (event_id int primary key);
create table other_events (event_id int primary key);
create table events_child () inherits (events);
explain (costs off)
select event_id
 from (select event_id from events
       union all
       select event_id from other_events) ss
 order by event_id;
                 QUERY PLAN                 
--------------------------------------------
 Gather Motion 3:1  (slice1; segments: 3)
   Merge Key: events.event_id
   ->  Sort
         Sort Key: events.event_id
         ->  Append
               ->  Seq Scan on events
               ->  Seq Scan on events_child
               ->  Seq Scan on other_events
 Optimizer: Postgres query optimizer
(9 rows)

drop table events_child, events, other_events;
reset enable_indexonlyscan;
-- Test constraint exclusion of UNION ALL subqueries
explain (costs off)
 SELECT * FROM
  (SELECT 1 AS t, * FROM tenk1 a
   UNION ALL
   SELECT 2 AS t, * FROM tenk1 b) c
 WHERE t = 2;
                QUERY PLAN                
------------------------------------------
 Gather Motion 3:1  (slice1; segments: 3)
   ->  Append
         ->  Seq Scan on tenk1 b
 Optimizer: Postgres query optimizer
(4 rows)

-- Test that we push quals into UNION sub-selects only when it's safe
explain (costs off)
SELECT * FROM
  (SELECT 1 AS t, 2 AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x < 4;
                    QUERY PLAN                     
---------------------------------------------------
 Unique
   Group Key: "outer".t, "outer".x
   ->  Sort
         Sort Key (Distinct): "outer".t, "outer".x
         ->  Append
               ->  Result
               ->  Result
                     One-Time Filter: false
 Optimizer: Postgres query optimizer
(9 rows)

SELECT * FROM
  (SELECT 1 AS t, 2 AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x < 4;
 t | x 
---+---
 1 | 2
(1 row)

explain (costs off)
SELECT * FROM
  (SELECT 1 AS t, generate_series(1,10) AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x < 4
ORDER BY x;
                          QUERY PLAN                          
--------------------------------------------------------------
 Sort
   Sort Key: ss.x
   ->  Subquery Scan on ss
         Filter: (ss.x < 4)
         ->  HashAggregate
               Group Key: "outer".t, (generate_series(1, 10))
               ->  Append
                     ->  Result
                     ->  Result
 Optimizer: Postgres query optimizer
(10 rows)

SELECT * FROM
  (SELECT 1 AS t, generate_series(1,10) AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x < 4
ORDER BY x;
 t | x 
---+---
 1 | 1
 1 | 2
 1 | 3
(3 rows)

explain (costs off)
SELECT * FROM
  (SELECT 1 AS t, (random()*3)::int AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x > 3;
                                      QUERY PLAN                                       
---------------------------------------------------------------------------------------
 Subquery Scan on ss
   Filter: (ss.x > 3)
   ->  Unique
         Group Key: "outer".t, ((($0 * 3::double precision))::integer)
         ->  Sort
               Sort Key (Distinct): "outer".t, ((($0 * 3::double precision))::integer)
               ->  Append
                     ->  Result
                           InitPlan 1 (returns $0)
                             ->  Result
                     ->  Result
 Optimizer: Postgres query optimizer
(12 rows)

SELECT * FROM
  (SELECT 1 AS t, (random()*3)::int AS x
   UNION
   SELECT 2 AS t, 4 AS x) ss
WHERE x > 3;
 t | x 
---+---
 2 | 4
(1 row)

-- Test proper handling of parameterized appendrel paths when the
-- potential join qual is expensive
create function expensivefunc(int) returns int
language plpgsql immutable strict cost 10000
as $$begin return $1; end$$;
create temp table t3 as select generate_series(-1000,1000) as x;
create index t3i on t3 (expensivefunc(x));
analyze t3;
explain (costs off)
select * from
  (select * from t3 a union all select * from t3 b) ss
  join int4_tbl on f1 = expensivefunc(x);
                       QUERY PLAN                        
---------------------------------------------------------
 Gather Motion 3:1  (slice2; segments: 3)
   ->  Hash Join
         Hash Cond: (int4_tbl.f1 = expensivefunc(a.x))
         ->  Broadcast Motion 3:3  (slice1; segments: 3)
               ->  Seq Scan on int4_tbl
         ->  Hash
               ->  Append
                     ->  Seq Scan on t3 a
                     ->  Seq Scan on t3 b
 Optimizer: Postgres query optimizer
(10 rows)

select * from
  (select * from t3 a union all select * from t3 b) ss
  join int4_tbl on f1 = expensivefunc(x);
 x | f1 
---+----
 0 |  0
 0 |  0
(2 rows)

drop table t3;
drop function expensivefunc(int);