set enable_seqscan=off;
CREATE TABLE test_uuid (
	i uuid
);
INSERT INTO test_uuid VALUES
	( '00000000-0000-0000-0000-000000000000' ),
	( '299bc99f-2f79-4e3e-bfea-2cbfd62a7c27' ),
	( '6264af33-0d43-4337-bf4e-43509b8a4be8' ),
	( 'ce41c936-6acb-4feb-8c91-852a673e5a5c' ),
	( 'd2ce731f-f2a8-4a2b-be37-8f0ba637427f' ),
	( 'ffffffff-ffff-ffff-ffff-ffffffffffff' )
;
CREATE INDEX idx_uuid ON test_uuid USING gin (i);
SELECT * FROM test_uuid WHERE i<'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                  i                   
--------------------------------------
 00000000-0000-0000-0000-000000000000
 299bc99f-2f79-4e3e-bfea-2cbfd62a7c27
 6264af33-0d43-4337-bf4e-43509b8a4be8
(3 rows)

SELECT * FROM test_uuid WHERE i<='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                  i                   
--------------------------------------
 00000000-0000-0000-0000-000000000000
 299bc99f-2f79-4e3e-bfea-2cbfd62a7c27
 6264af33-0d43-4337-bf4e-43509b8a4be8
 ce41c936-6acb-4feb-8c91-852a673e5a5c
(4 rows)

SELECT * FROM test_uuid WHERE i='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                  i                   
--------------------------------------
 ce41c936-6acb-4feb-8c91-852a673e5a5c
(1 row)

SELECT * FROM test_uuid WHERE i>='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                  i                   
--------------------------------------
 ce41c936-6acb-4feb-8c91-852a673e5a5c
 d2ce731f-f2a8-4a2b-be37-8f0ba637427f
 ffffffff-ffff-ffff-ffff-ffffffffffff
(3 rows)

SELECT * FROM test_uuid WHERE i>'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                  i                   
--------------------------------------
 d2ce731f-f2a8-4a2b-be37-8f0ba637427f
 ffffffff-ffff-ffff-ffff-ffffffffffff
(2 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_uuid WHERE i<'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                                  QUERY PLAN                                  
------------------------------------------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_uuid
         Recheck Cond: (i < 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
         ->  Bitmap Index Scan on idx_uuid
               Index Cond: (i < 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_uuid WHERE i<='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                                  QUERY PLAN                                   
-------------------------------------------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_uuid
         Recheck Cond: (i <= 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
         ->  Bitmap Index Scan on idx_uuid
               Index Cond: (i <= 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_uuid WHERE i='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                               QUERY PLAN                               
------------------------------------------------------------------------
 Bitmap Heap Scan on test_uuid
   Recheck Cond: (i = 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
   ->  Bitmap Index Scan on idx_uuid
         Index Cond: (i = 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
(4 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_uuid WHERE i>='ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                                  QUERY PLAN                                   
-------------------------------------------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_uuid
         Recheck Cond: (i >= 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
         ->  Bitmap Index Scan on idx_uuid
               Index Cond: (i >= 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_uuid WHERE i>'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid ORDER BY i;
                                  QUERY PLAN                                  
------------------------------------------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_uuid
         Recheck Cond: (i > 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
         ->  Bitmap Index Scan on idx_uuid
               Index Cond: (i > 'ce41c936-6acb-4feb-8c91-852a673e5a5c'::uuid)
(6 rows)