SHOW server_version \gset
SELECT substring(:'server_version', '\d+')::int >= 15 AS server_version_ge_15
\gset
\if :server_version_ge_15
\else
\q
\endif
-- MERGE command performs a join from data_source to target_table_name
DROP SCHEMA IF EXISTS merge_vcore_schema CASCADE;
NOTICE:  schema "merge_vcore_schema" does not exist, skipping
--MERGE INTO target
--USING source
--WHEN NOT MATCHED
--WHEN MATCHED AND <condition>
--WHEN MATCHED
CREATE SCHEMA merge_vcore_schema;
SET search_path TO merge_vcore_schema;
SET citus.shard_count TO 4;
SET citus.next_shard_id TO 4000000;
SET citus.explain_all_tasks TO true;
SET citus.shard_replication_factor TO 1;
SET citus.max_adaptive_executor_pool_size TO 1;
SET client_min_messages = warning;
SELECT 1 FROM master_add_node('localhost', :master_port, groupid => 0);
 ?column?
---------------------------------------------------------------------
        1
(1 row)

RESET client_min_messages;
-- ****************************************** CASE 1 : Both are singleSharded***************************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', null, colocate_with=>'none');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', null, colocate_with=>'none');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus MERGE INTO ...)
   MERGE INTO target method: pull to coordinator
   ->  Custom Scan (Citus Adaptive)
         Task Count: 1
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000000 source
(8 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
-- *************** CASE 2 : source is single sharded and target is distributed *******************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', null, colocate_with=>'none');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', 'id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus MERGE INTO ...)
   MERGE INTO target method: pull to coordinator
   ->  Custom Scan (Citus Adaptive)
         Task Count: 1
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000002 source
(8 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
-- *************** CASE 3 : source is distributed  and target is single sharded *******************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', 'id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', null);
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus MERGE INTO ...)
   MERGE INTO target method: pull to coordinator
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000007 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000008 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000009 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000010 source
(17 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
-- *************** CASE 4 : both are distributed  *******************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', 'id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', 'id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus MERGE INTO ...)
   MERGE INTO target method: repartition
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000012 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000013 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000014 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000015 source
(17 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
-- *************** CASE 5 : both are distributed & colocated *******************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', 'id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', 'id', colocate_with=>'source');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus MERGE INTO ...)
   MERGE INTO target method: repartition
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000020 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000021 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000022 source
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  Seq Scan on source_4000023 source
(17 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
-- *************** CASE 6 : both are singlesharded & colocated *******************************
CREATE TABLE source (
    id bigint,
    doc text
);
CREATE TABLE target (
    id bigint,
    doc text
);
SELECT create_distributed_table('source', null);
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('target', null, colocate_with=>'source');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO source (id, doc) VALUES (1, '{"a" : 1}'), (1, '{"a" : 2}');
-- insert
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"a" : 1}
  2 | {"a" : 2}
(2 rows)

-- update
MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id) AND src.doc = target.doc
WHEN MATCHED THEN
UPDATE SET doc = '{"b" : 1}'
WHEN NOT MATCHED THEN
INSERT (id, doc)
VALUES (src.t_id, doc);
SELECT * FROM target;
 id |    doc
---------------------------------------------------------------------
  2 | {"b" : 1}
  2 | {"b" : 1}
(2 rows)

-- Explain
EXPLAIN (costs off, timing off, summary off) MERGE INTO ONLY target USING (SELECT 2::bigint AS t_id, doc FROM source) src
ON (src.t_id = target.id)
WHEN MATCHED THEN DO NOTHING;
                           QUERY PLAN
---------------------------------------------------------------------
 Custom Scan (Citus Adaptive)
   Task Count: 1
   Tasks Shown: All
   ->  Task
         Node: host=localhost port=xxxxx dbname=regression
         ->  Merge on target_4000029 target
               ->  Nested Loop
                     ->  Seq Scan on source_4000028 source
                     ->  Materialize
                           ->  Seq Scan on target_4000029 target
                                 Filter: ('2'::bigint = id)
(11 rows)

DROP TABLE IF EXISTS source;
DROP TABLE IF EXISTS target;
DROP SCHEMA IF EXISTS merge_vcore_schema CASCADE;