+SET enable_seqscan to false;
+-- test search for "not equals"
+CREATE TABLE test_ne (
+ a TIMESTAMP,
+ b NUMERIC
+);
+CREATE INDEX test_ne_idx ON test_ne USING gist (a, b);
+INSERT INTO test_ne SELECT '2009-01-01', 10.7 FROM generate_series(1,1000);
+INSERT INTO test_ne VALUES('2007-02-03', -91.3);
+INSERT INTO test_ne VALUES('2011-09-01', 43.7);
+INSERT INTO test_ne SELECT '2009-01-01', 10.7 FROM generate_series(1,1000);
+EXPLAIN (COSTS OFF) SELECT * FROM test_ne WHERE a <> '2009-01-01' AND b <> 10.7;
+ QUERY PLAN
+------------------------------------------------------------------------------------------------------
+ Bitmap Heap Scan on test_ne
+ Recheck Cond: ((a <> 'Thu Jan 01 00:00:00 2009'::timestamp without time zone) AND (b <> 10.7))
+ -> Bitmap Index Scan on test_ne_idx
+ Index Cond: ((a <> 'Thu Jan 01 00:00:00 2009'::timestamp without time zone) AND (b <> 10.7))
+(4 rows)
+
+SELECT * FROM test_ne WHERE a <> '2009-01-01' AND b <> 10.7;
+ a | b
+--------------------------+-------
+ Sat Feb 03 00:00:00 2007 | -91.3
+ Thu Sep 01 00:00:00 2011 | 43.7
+(2 rows)
+
+-- test search for "not equals" using an exclusion constraint
+CREATE TABLE zoo (
+ cage INTEGER,
+ animal TEXT,
+ EXCLUDE USING gist (cage WITH =, animal WITH <>)
+);
+NOTICE: CREATE TABLE / EXCLUDE will create implicit index "zoo_cage_animal_excl" for table "zoo"
+INSERT INTO zoo VALUES(123, 'zebra');
+INSERT INTO zoo VALUES(123, 'zebra');
+INSERT INTO zoo VALUES(123, 'lion');
+ERROR: conflicting key value violates exclusion constraint "zoo_cage_animal_excl"
+DETAIL: Key (cage, animal)=(123, lion) conflicts with existing key (cage, animal)=(123, zebra).
+INSERT INTO zoo VALUES(124, 'lion');