Add tests for MERGE ... WHEN NOT MATCHED BY SOURCE

src/test/regress/expected/pg17.out

@@ -2195,6 +2195,472 @@ CONTEXT:  PL/pgSQL function public.explain_filter(text) line XX at FOR over EXEC
 
 RESET citus.log_remote_commands;
 -- End of EXPLAIN MEMORY SERIALIZE tests
+-- Add support for MERGE ... WHEN NOT MATCHED BY SOURCE.
+-- Relevant PG commit:
+-- https://github.com/postgres/postgres/commit/0294df2f1
+SET citus.next_shard_id TO 25122024;
+-- Citus local tables
+CREATE TABLE citus_local_target (tid integer, balance float, val text);
+CREATE TABLE citus_local_source (sid integer, delta float);
+SELECT citus_add_local_table_to_metadata('citus_local_target');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122024) already exists.
+SELECT citus_add_local_table_to_metadata('citus_local_source');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122025) already exists.
+INSERT INTO citus_local_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_local_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+-- Citus distributed tables
+CREATE TABLE citus_distributed_target (tid integer, balance float, val text);
+CREATE TABLE citus_distributed_source (sid integer, delta float);
+SELECT create_distributed_table('citus_distributed_target', 'tid');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122026) already exists.
+SELECT create_distributed_table('citus_distributed_source', 'sid');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122027) already exists.
+INSERT INTO citus_distributed_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_distributed_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+-- Citus reference tables
+CREATE TABLE citus_reference_target (tid integer, balance float, val text);
+CREATE TABLE citus_reference_source (sid integer, delta float);
+SELECT create_reference_table('citus_reference_target');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122028) already exists.
+SELECT create_reference_table('citus_reference_source');
+ERROR:  duplicate key value violates unique constraint "pg_dist_shard_shardid_index"
+DETAIL:  Key (shardid)=(25122029) already exists.
+INSERT INTO citus_reference_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_reference_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+-- Try all combinations of tables with two queries:
+-- 1: Simple Merge
+-- 2: Merge with a constant qual
+--
+-- Simple Merge expected output
+--  tid | balance |              val
+---------------------------------------------------------------------
+--   1 |     110 | initial updated by merge
+--   2 |      20 | inserted by merge
+--   3 |     330 | initial updated by merge
+--   4 |      40 | inserted by merge
+--   5 |     550 | initial updated by merge
+--   6 |      60 | inserted by merge
+--   7 |     770 | initial updated by merge
+--   8 |      80 | inserted by merge
+--   9 |     990 | initial updated by merge
+--  10 |     100 | inserted by merge
+--  11 |    1210 | initial updated by merge
+--  12 |     120 | inserted by merge
+--  13 |    1430 | initial updated by merge
+--  14 |     140 | inserted by merge
+--  15 |    1500 | initial not matched by source
+-- (15 rows)
+--
+-- Merge with a constant qual expected output
+--  tid | balance |              val
+---------------------------------------------------------------------
+--   1 |     110 | initial updated by merge
+--   2 |      20 | inserted by merge
+--   3 |     300 | initial not matched by source
+--   3 |      30 | inserted by merge
+--   4 |      40 | inserted by merge
+--   5 |     500 | initial not matched by source
+--   5 |      50 | inserted by merge
+--   6 |      60 | inserted by merge
+--   7 |     700 | initial not matched by source
+--   7 |      70 | inserted by merge
+--   8 |      80 | inserted by merge
+--   9 |     900 | initial not matched by source
+--   9 |      90 | inserted by merge
+--  10 |     100 | inserted by merge
+--  11 |    1100 | initial not matched by source
+--  11 |     110 | inserted by merge
+--  12 |     120 | inserted by merge
+--  13 |    1300 | initial not matched by source
+--  13 |     130 | inserted by merge
+--  14 |     140 | inserted by merge
+--  15 |    1500 | initial not matched by source
+-- (21 rows)
+-- Local-Local
+-- Let's also print the command here
+-- try simple MERGE
+BEGIN;
+SET citus.log_local_commands TO on;
+MERGE INTO citus_local_target t
+  USING citus_local_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     330 | initial updated by merge
+   4 |      40 | inserted by merge
+   5 |     550 | initial updated by merge
+   6 |      60 | inserted by merge
+   7 |     770 | initial updated by merge
+   8 |      80 | inserted by merge
+   9 |     990 | initial updated by merge
+  10 |     100 | inserted by merge
+  11 |    1210 | initial updated by merge
+  12 |     120 | inserted by merge
+  13 |    1430 | initial updated by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(15 rows)
+
+ROLLBACK;
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_local_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     300 | initial not matched by source
+   3 |      30 | inserted by merge
+   4 |      40 | inserted by merge
+   5 |     500 | initial not matched by source
+   5 |      50 | inserted by merge
+   6 |      60 | inserted by merge
+   7 |     700 | initial not matched by source
+   7 |      70 | inserted by merge
+   8 |      80 | inserted by merge
+   9 |     900 | initial not matched by source
+   9 |      90 | inserted by merge
+  10 |     100 | inserted by merge
+  11 |    1100 | initial not matched by source
+  11 |     110 | inserted by merge
+  12 |     120 | inserted by merge
+  13 |    1300 | initial not matched by source
+  13 |     130 | inserted by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(21 rows)
+
+ROLLBACK;
+-- Local-Reference
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     330 | initial updated by merge
+   4 |      40 | inserted by merge
+   5 |     550 | initial updated by merge
+   6 |      60 | inserted by merge
+   7 |     770 | initial updated by merge
+   8 |      80 | inserted by merge
+   9 |     990 | initial updated by merge
+  10 |     100 | inserted by merge
+  11 |    1210 | initial updated by merge
+  12 |     120 | inserted by merge
+  13 |    1430 | initial updated by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(15 rows)
+
+ROLLBACK;
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     300 | initial not matched by source
+   3 |      30 | inserted by merge
+   4 |      40 | inserted by merge
+   5 |     500 | initial not matched by source
+   5 |      50 | inserted by merge
+   6 |      60 | inserted by merge
+   7 |     700 | initial not matched by source
+   7 |      70 | inserted by merge
+   8 |      80 | inserted by merge
+   9 |     900 | initial not matched by source
+   9 |      90 | inserted by merge
+  10 |     100 | inserted by merge
+  11 |    1100 | initial not matched by source
+  11 |     110 | inserted by merge
+  12 |     120 | inserted by merge
+  13 |    1300 | initial not matched by source
+  13 |     130 | inserted by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(21 rows)
+
+ROLLBACK;
+-- Local-Distributed - Merge currently not supported, Feature in development.
+-- try simple MERGE
+MERGE INTO citus_local_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+-- Distributed-Local
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_local_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     330 | initial updated by merge
+   4 |      40 | inserted by merge
+   5 |     550 | initial updated by merge
+   6 |      60 | inserted by merge
+   7 |     770 | initial updated by merge
+   8 |      80 | inserted by merge
+   9 |     990 | initial updated by merge
+  10 |     100 | inserted by merge
+  11 |    1210 | initial updated by merge
+  12 |     120 | inserted by merge
+  13 |    1430 | initial updated by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(15 rows)
+
+ROLLBACK;
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_local_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     300 | initial not matched by source
+   3 |      30 | inserted by merge
+   4 |      40 | inserted by merge
+   5 |     500 | initial not matched by source
+   5 |      50 | inserted by merge
+   6 |      60 | inserted by merge
+   7 |     700 | initial not matched by source
+   7 |      70 | inserted by merge
+   8 |      80 | inserted by merge
+   9 |     900 | initial not matched by source
+   9 |      90 | inserted by merge
+  10 |     100 | inserted by merge
+  11 |    1100 | initial not matched by source
+  11 |     110 | inserted by merge
+  12 |     120 | inserted by merge
+  13 |    1300 | initial not matched by source
+  13 |     130 | inserted by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(21 rows)
+
+ROLLBACK;
+-- Distributed-Distributed
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     330 | initial updated by merge
+   4 |      40 | inserted by merge
+   5 |     550 | initial updated by merge
+   6 |      60 | inserted by merge
+   7 |     770 | initial updated by merge
+   8 |      80 | inserted by merge
+   9 |     990 | initial updated by merge
+  10 |     100 | inserted by merge
+  11 |    1210 | initial updated by merge
+  12 |     120 | inserted by merge
+  13 |    1430 | initial updated by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(15 rows)
+
+ROLLBACK;
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     300 | initial not matched by source
+   3 |      30 | inserted by merge
+   4 |      40 | inserted by merge
+   5 |     500 | initial not matched by source
+   5 |      50 | inserted by merge
+   6 |      60 | inserted by merge
+   7 |     700 | initial not matched by source
+   7 |      70 | inserted by merge
+   8 |      80 | inserted by merge
+   9 |     900 | initial not matched by source
+   9 |      90 | inserted by merge
+  10 |     100 | inserted by merge
+  11 |    1100 | initial not matched by source
+  11 |     110 | inserted by merge
+  12 |     120 | inserted by merge
+  13 |    1300 | initial not matched by source
+  13 |     130 | inserted by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(21 rows)
+
+ROLLBACK;
+-- Distributed-Reference
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     330 | initial updated by merge
+   4 |      40 | inserted by merge
+   5 |     550 | initial updated by merge
+   6 |      60 | inserted by merge
+   7 |     770 | initial updated by merge
+   8 |      80 | inserted by merge
+   9 |     990 | initial updated by merge
+  10 |     100 | inserted by merge
+  11 |    1210 | initial updated by merge
+  12 |     120 | inserted by merge
+  13 |    1430 | initial updated by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(15 rows)
+
+ROLLBACK;
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ tid | balance |              val
+---------------------------------------------------------------------
+   1 |     110 | initial updated by merge
+   2 |      20 | inserted by merge
+   3 |     300 | initial not matched by source
+   3 |      30 | inserted by merge
+   4 |      40 | inserted by merge
+   5 |     500 | initial not matched by source
+   5 |      50 | inserted by merge
+   6 |      60 | inserted by merge
+   7 |     700 | initial not matched by source
+   7 |      70 | inserted by merge
+   8 |      80 | inserted by merge
+   9 |     900 | initial not matched by source
+   9 |      90 | inserted by merge
+  10 |     100 | inserted by merge
+  11 |    1100 | initial not matched by source
+  11 |     110 | inserted by merge
+  12 |     120 | inserted by merge
+  13 |    1300 | initial not matched by source
+  13 |     130 | inserted by merge
+  14 |     140 | inserted by merge
+  15 |    1500 | initial not matched by source
+(21 rows)
+
+ROLLBACK;
+-- Reference-N/A - Reference table as target is not allowed in Merge
+-- try simple MERGE
+MERGE INTO citus_reference_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+-- End of MERGE ... WHEN NOT MATCHED BY SOURCE tests
 \set VERBOSITY terse
 SET client_min_messages TO WARNING;
 DROP SCHEMA pg17 CASCADE;

src/test/regress/sql/pg17.sql

@@ -1080,6 +1080,256 @@ select public.explain_filter('explain (analyze,serialize) create temp table expl
 
 RESET citus.log_remote_commands;
 -- End of EXPLAIN MEMORY SERIALIZE tests
+-- Add support for MERGE ... WHEN NOT MATCHED BY SOURCE.
+-- Relevant PG commit:
+-- https://github.com/postgres/postgres/commit/0294df2f1
+
+SET citus.next_shard_id TO 25122024;
+
+-- Citus local tables
+CREATE TABLE citus_local_target (tid integer, balance float, val text);
+CREATE TABLE citus_local_source (sid integer, delta float);
+SELECT citus_add_local_table_to_metadata('citus_local_target');
+SELECT citus_add_local_table_to_metadata('citus_local_source');
+INSERT INTO citus_local_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_local_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+-- Citus distributed tables
+CREATE TABLE citus_distributed_target (tid integer, balance float, val text);
+CREATE TABLE citus_distributed_source (sid integer, delta float);
+SELECT create_distributed_table('citus_distributed_target', 'tid');
+SELECT create_distributed_table('citus_distributed_source', 'sid');
+INSERT INTO citus_distributed_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_distributed_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+-- Citus reference tables
+CREATE TABLE citus_reference_target (tid integer, balance float, val text);
+CREATE TABLE citus_reference_source (sid integer, delta float);
+SELECT create_reference_table('citus_reference_target');
+SELECT create_reference_table('citus_reference_source');
+INSERT INTO citus_reference_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
+INSERT INTO citus_reference_source SELECT id, id * 10  FROM generate_series(1,14) AS id;
+
+-- Try all combinations of tables with two queries:
+-- 1: Simple Merge
+-- 2: Merge with a constant qual
+--
+-- Simple Merge expected output
+--  tid | balance |              val              
+-----+---------+-------------------------------
+--   1 |     110 | initial updated by merge
+--   2 |      20 | inserted by merge
+--   3 |     330 | initial updated by merge
+--   4 |      40 | inserted by merge
+--   5 |     550 | initial updated by merge
+--   6 |      60 | inserted by merge
+--   7 |     770 | initial updated by merge
+--   8 |      80 | inserted by merge
+--   9 |     990 | initial updated by merge
+--  10 |     100 | inserted by merge
+--  11 |    1210 | initial updated by merge
+--  12 |     120 | inserted by merge
+--  13 |    1430 | initial updated by merge
+--  14 |     140 | inserted by merge
+--  15 |    1500 | initial not matched by source
+-- (15 rows)
+-- 
+-- Merge with a constant qual expected output
+--  tid | balance |              val              
+-----+---------+-------------------------------
+--   1 |     110 | initial updated by merge
+--   2 |      20 | inserted by merge
+--   3 |     300 | initial not matched by source
+--   3 |      30 | inserted by merge
+--   4 |      40 | inserted by merge
+--   5 |     500 | initial not matched by source
+--   5 |      50 | inserted by merge
+--   6 |      60 | inserted by merge
+--   7 |     700 | initial not matched by source
+--   7 |      70 | inserted by merge
+--   8 |      80 | inserted by merge
+--   9 |     900 | initial not matched by source
+--   9 |      90 | inserted by merge
+--  10 |     100 | inserted by merge
+--  11 |    1100 | initial not matched by source
+--  11 |     110 | inserted by merge
+--  12 |     120 | inserted by merge
+--  13 |    1300 | initial not matched by source
+--  13 |     130 | inserted by merge
+--  14 |     140 | inserted by merge
+--  15 |    1500 | initial not matched by source
+-- (21 rows)
+
+-- Local-Local
+-- Let's also print the command here
+-- try simple MERGE
+BEGIN;
+SET citus.log_local_commands TO on;
+MERGE INTO citus_local_target t
+  USING citus_local_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ROLLBACK;
+
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_local_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ROLLBACK;
+
+-- Local-Reference
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ROLLBACK;
+
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_local_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_local_target ORDER BY tid, val;
+ROLLBACK;
+
+-- Local-Distributed - Merge currently not supported, Feature in development.
+-- try simple MERGE
+MERGE INTO citus_local_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+
+-- Distributed-Local
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_local_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_local_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- Distributed-Distributed
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- Distributed-Reference
+-- try simple MERGE
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- same with a constant qual
+BEGIN;
+MERGE INTO citus_distributed_target t
+  USING citus_reference_source s
+  ON t.tid = s.sid AND tid = 1
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+SELECT * FROM citus_distributed_target ORDER BY tid, val;
+ROLLBACK;
+
+-- Reference-N/A - Reference table as target is not allowed in Merge
+-- try simple MERGE
+MERGE INTO citus_reference_target t
+  USING citus_distributed_source s
+  ON t.tid = s.sid
+  WHEN MATCHED THEN
+    UPDATE SET balance = balance + delta, val = val || ' updated by merge'
+  WHEN NOT MATCHED THEN
+    INSERT VALUES (sid, delta, 'inserted by merge')
+  WHEN NOT MATCHED BY SOURCE THEN
+    UPDATE SET val = val || ' not matched by source';
+
+-- End of MERGE ... WHEN NOT MATCHED BY SOURCE tests
 
 \set VERBOSITY terse
 SET client_min_messages TO WARNING;