set enable_seqscan=off;
CREATE TABLE test_int8 (
	i int8
);
INSERT INTO test_int8 VALUES (-2),(-1),(0),(1),(2),(3);
CREATE INDEX idx_int8 ON test_int8 USING gin (i);
SELECT * FROM test_int8 WHERE i<1::int8 ORDER BY i;
 i  
----
 -2
 -1
  0
(3 rows)

SELECT * FROM test_int8 WHERE i<=1::int8 ORDER BY i;
 i  
----
 -2
 -1
  0
  1
(4 rows)

SELECT * FROM test_int8 WHERE i=1::int8 ORDER BY i;
 i 
---
 1
(1 row)

SELECT * FROM test_int8 WHERE i>=1::int8 ORDER BY i;
 i 
---
 1
 2
 3
(3 rows)

SELECT * FROM test_int8 WHERE i>1::int8 ORDER BY i;
 i 
---
 2
 3
(2 rows)

explain (costs off)
SELECT * FROM test_int8 WHERE i<1::int2 ORDER BY i;
                  QUERY PLAN                   
-----------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_int8
         Recheck Cond: (i < '1'::smallint)
         ->  Bitmap Index Scan on idx_int8
               Index Cond: (i < '1'::smallint)
(6 rows)

SELECT * FROM test_int8 WHERE i<1::int2 ORDER BY i;
 i  
----
 -2
 -1
  0
(3 rows)

SELECT * FROM test_int8 WHERE i<=1::int2 ORDER BY i;
 i  
----
 -2
 -1
  0
  1
(4 rows)

SELECT * FROM test_int8 WHERE i=1::int2 ORDER BY i;
 i 
---
 1
(1 row)

SELECT * FROM test_int8 WHERE i>=1::int2 ORDER BY i;
 i 
---
 1
 2
 3
(3 rows)

SELECT * FROM test_int8 WHERE i>1::int2 ORDER BY i;
 i 
---
 2
 3
(2 rows)

explain (costs off)
SELECT * FROM test_int8 WHERE i<1::int4 ORDER BY i;
                QUERY PLAN                 
-------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_int8
         Recheck Cond: (i < 1)
         ->  Bitmap Index Scan on idx_int8
               Index Cond: (i < 1)
(6 rows)

SELECT * FROM test_int8 WHERE i<1::int4 ORDER BY i;
 i  
----
 -2
 -1
  0
(3 rows)

SELECT * FROM test_int8 WHERE i<=1::int4 ORDER BY i;
 i  
----
 -2
 -1
  0
  1
(4 rows)

SELECT * FROM test_int8 WHERE i=1::int4 ORDER BY i;
 i 
---
 1
(1 row)

SELECT * FROM test_int8 WHERE i>=1::int4 ORDER BY i;
 i 
---
 1
 2
 3
(3 rows)

SELECT * FROM test_int8 WHERE i>1::int4 ORDER BY i;
 i 
---
 2
 3
(2 rows)