diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 9f05b3654c..59acf67a36 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -210,7 +210,7 @@ ExecOpenIndices(ResultRelInfo *resultRelInfo, bool speculative)
 		 * If the indexes are to be used for speculative insertion, add extra
 		 * information required by unique index entries.
 		 */
-		if (speculative && ii->ii_Unique)
+		if (speculative && ii->ii_Unique && !indexDesc->rd_index->indisexclusion)
 			BuildSpeculativeIndexInfo(indexDesc, ii);
 
 		relationDescs[i] = indexDesc;
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index 130f838629..775c3e26cd 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -815,7 +815,7 @@ infer_arbiter_indexes(PlannerInfo *root)
 		 */
 		if (indexOidFromConstraint == idxForm->indexrelid)
 		{
-			if (!idxForm->indisunique && onconflict->action == ONCONFLICT_UPDATE)
+			if (idxForm->indisexclusion && onconflict->action == ONCONFLICT_UPDATE)
 				ereport(ERROR,
 						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 						 errmsg("ON CONFLICT DO UPDATE not supported with exclusion constraints")));
@@ -840,6 +840,13 @@ infer_arbiter_indexes(PlannerInfo *root)
 		if (!idxForm->indisunique)
 			goto next;
 
+		/*
+		 * So-called unique constraints with WITHOUT OVERLAPS are really
+		 * exclusion constraints, so skip those too.
+		 */
+		if (idxForm->indisexclusion)
+			goto next;
+
 		/* Build BMS representation of plain (non expression) index attrs */
 		indexedAttrs = NULL;
 		for (natt = 0; natt < idxForm->indnkeyatts; natt++)
diff --git a/src/test/regress/expected/without_overlaps.out b/src/test/regress/expected/without_overlaps.out
index abc22d0113..e2f2a1cbe2 100644
--- a/src/test/regress/expected/without_overlaps.out
+++ b/src/test/regress/expected/without_overlaps.out
@@ -453,6 +453,182 @@ DROP TABLE temporal_partitioned;
 ALTER TABLE temporal_rng REPLICA IDENTITY USING INDEX temporal_rng_pk;
 ERROR:  cannot use non-unique index "temporal_rng_pk" as replica identity
 --
+-- ON CONFLICT
+--
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+ [1,2) | [2010-01-01,2020-01-01)
+ [2,3) | [2005-01-01,2006-01-01)
+(3 rows)
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+ [1,2) | [2010-01-01,2020-01-01)
+ [2,3) | [2005-01-01,2006-01-01)
+(3 rows)
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+-- with a UNIQUE constraint:
+CREATE TABLE temporal3 (
+	id int4range,
+	valid_at daterange,
+	CONSTRAINT temporal3_uq UNIQUE (id, valid_at WITHOUT OVERLAPS)
+);
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+ [1,2) | [2010-01-01,2020-01-01)
+ [2,3) | [2005-01-01,2006-01-01)
+(3 rows)
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+ [1,2) | [2010-01-01,2020-01-01)
+ [2,3) | [2005-01-01,2006-01-01)
+(3 rows)
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+ERROR:  ON CONFLICT DO UPDATE not supported with exclusion constraints
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+  id   |        valid_at         
+-------+-------------------------
+ [1,2) | [2000-01-01,2010-01-01)
+(1 row)
+
+DROP TABLE temporal3;
+--
 -- test FK dependencies
 --
 -- can't drop a range referenced by an FK, unless with CASCADE
diff --git a/src/test/regress/sql/without_overlaps.sql b/src/test/regress/sql/without_overlaps.sql
index d4ae03ae52..5d41a6bd62 100644
--- a/src/test/regress/sql/without_overlaps.sql
+++ b/src/test/regress/sql/without_overlaps.sql
@@ -319,6 +319,119 @@ DROP TABLE temporal_partitioned;
 -- (should fail)
 ALTER TABLE temporal_rng REPLICA IDENTITY USING INDEX temporal_rng_pk;
 
+--
+-- ON CONFLICT
+--
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO NOTHING;
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+
+TRUNCATE temporal_rng;
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+-- id matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+-- date matches but no conflict
+INSERT INTO temporal_rng (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal_rng_pk DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+SELECT * FROM temporal_rng ORDER BY id, valid_at;
+
+-- with a UNIQUE constraint:
+
+CREATE TABLE temporal3 (
+	id int4range,
+	valid_at daterange,
+	CONSTRAINT temporal3_uq UNIQUE (id, valid_at WITHOUT OVERLAPS)
+);
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT DO NOTHING;
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO NOTHING;
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO NOTHING;
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT (id, valid_at) DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+
+TRUNCATE temporal3;
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2000-01-01', '2010-01-01'));
+-- with a conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[2,3)';
+-- id matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[1,2)', daterange('2010-01-01', '2020-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[3,4)';
+-- date matches but no conflict
+INSERT INTO temporal3 (id, valid_at) VALUES ('[2,3)', daterange('2005-01-01', '2006-01-01')) ON CONFLICT ON CONSTRAINT temporal3_uq DO UPDATE SET id = EXCLUDED.id + '[4,5)';
+SELECT * FROM temporal3 ORDER BY id, valid_at;
+
+DROP TABLE temporal3;
+
 --
 -- test FK dependencies
 --