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SSL merge.out
Sprache: unbekannt
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Spracherkennung für: .out vermutete Sprache: Unknown {[0] [0] [0]} [Methode: Schwerpunktbildung, einfache Gewichte, sechs Dimensionen]
--
-- MERGE
--
CREATE USER regress_merge_privs;
CREATE USER regress_merge_no_privs;
CREATE USER regress_merge_none;
DROP TABLE IF EXISTS target;
NOTICE: table "target" does not exist, skipping
DROP TABLE IF EXISTS source;
NOTICE: table "source" does not exist, skipping
CREATE TABLE target (tid integer, balance integer)
WITH (autovacuum_enabled=off);
CREATE TABLE source (sid integer, delta integer) -- no index
WITH (autovacuum_enabled=off);
INSERT INTO target VALUES (1, 10);
INSERT INTO target VALUES (2, 20);
INSERT INTO target VALUES (3, 30);
SELECT t.ctid is not null as matched, t.*, s.* FROM source s FULL OUTER JOIN target t ON s.sid = t.tid ORDER BY t.tid, s.sid;
matched | tid | balance | sid | delta
---------+-----+---------+-----+-------
t | 1 | 10 | |
t | 2 | 20 | |
t | 3 | 30 | |
(3 rows)
ALTER TABLE target OWNER TO regress_merge_privs;
ALTER TABLE source OWNER TO regress_merge_privs;
CREATE TABLE target2 (tid integer, balance integer)
WITH (autovacuum_enabled=off);
CREATE TABLE source2 (sid integer, delta integer)
WITH (autovacuum_enabled=off);
ALTER TABLE target2 OWNER TO regress_merge_no_privs;
ALTER TABLE source2 OWNER TO regress_merge_no_privs;
GRANT INSERT ON target TO regress_merge_no_privs;
SET SESSION AUTHORIZATION regress_merge_privs;
EXPLAIN (COSTS OFF)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
QUERY PLAN
----------------------------------------
Merge on target t
-> Merge Join
Merge Cond: (t.tid = s.sid)
-> Sort
Sort Key: t.tid
-> Seq Scan on target t
-> Sort
Sort Key: s.sid
-> Seq Scan on source s
(9 rows)
--
-- Errors
--
MERGE INTO target t RANDOMWORD
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
ERROR: syntax error at or near "RANDOMWORD"
LINE 1: MERGE INTO target t RANDOMWORD
^
-- MATCHED/INSERT error
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
INSERT DEFAULT VALUES;
ERROR: syntax error at or near "INSERT"
LINE 5: INSERT DEFAULT VALUES;
^
-- NOT MATCHED BY SOURCE/INSERT error
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED BY SOURCE THEN
INSERT DEFAULT VALUES;
ERROR: syntax error at or near "INSERT"
LINE 5: INSERT DEFAULT VALUES;
^
-- incorrectly specifying INTO target
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT INTO target DEFAULT VALUES;
ERROR: syntax error at or near "INTO"
LINE 5: INSERT INTO target DEFAULT VALUES;
^
-- Multiple VALUES clause
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (1,1), (2,2);
ERROR: syntax error at or near ","
LINE 5: INSERT VALUES (1,1), (2,2);
^
-- SELECT query for INSERT
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT SELECT (1, 1);
ERROR: syntax error at or near "SELECT"
LINE 5: INSERT SELECT (1, 1);
^
-- NOT MATCHED/UPDATE
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
UPDATE SET balance = 0;
ERROR: syntax error at or near "UPDATE"
LINE 5: UPDATE SET balance = 0;
^
-- NOT MATCHED BY TARGET/UPDATE
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED BY TARGET THEN
UPDATE SET balance = 0;
ERROR: syntax error at or near "UPDATE"
LINE 5: UPDATE SET balance = 0;
^
-- UPDATE tablename
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE target SET balance = 0;
ERROR: syntax error at or near "target"
LINE 5: UPDATE target SET balance = 0;
^
-- source and target names the same
MERGE INTO target
USING target
ON tid = tid
WHEN MATCHED THEN DO NOTHING;
ERROR: name "target" specified more than once
DETAIL: The name is used both as MERGE target table and data source.
-- used in a CTE without RETURNING
WITH foo AS (
MERGE INTO target USING source ON (true)
WHEN MATCHED THEN DELETE
) SELECT * FROM foo;
ERROR: WITH query "foo" does not have a RETURNING clause
LINE 4: ) SELECT * FROM foo;
^
-- used in COPY without RETURNING
COPY (
MERGE INTO target USING source ON (true)
WHEN MATCHED THEN DELETE
) TO stdout;
ERROR: COPY query must have a RETURNING clause
-- unsupported relation types
-- materialized view
CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
MERGE INTO mv t
USING source s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT DEFAULT VALUES;
ERROR: cannot execute MERGE on relation "mv"
DETAIL: This operation is not supported for materialized views.
DROP MATERIALIZED VIEW mv;
-- permissions
SET SESSION AUTHORIZATION regress_merge_none;
MERGE INTO target
USING (SELECT 1)
ON true
WHEN MATCHED THEN
DO NOTHING;
ERROR: permission denied for table target
SET SESSION AUTHORIZATION regress_merge_privs;
MERGE INTO target
USING source2
ON target.tid = source2.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
ERROR: permission denied for table source2
GRANT INSERT ON target TO regress_merge_no_privs;
SET SESSION AUTHORIZATION regress_merge_no_privs;
MERGE INTO target
USING source2
ON target.tid = source2.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
ERROR: permission denied for table target
GRANT UPDATE ON target2 TO regress_merge_privs;
SET SESSION AUTHORIZATION regress_merge_privs;
MERGE INTO target2
USING source
ON target2.tid = source.sid
WHEN MATCHED THEN
DELETE;
ERROR: permission denied for table target2
MERGE INTO target2
USING source
ON target2.tid = source.sid
WHEN NOT MATCHED THEN
INSERT DEFAULT VALUES;
ERROR: permission denied for table target2
-- check if the target can be accessed from source relation subquery; we should
-- not be able to do so
MERGE INTO target t
USING (SELECT * FROM source WHERE t.tid > sid) s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT DEFAULT VALUES;
ERROR: invalid reference to FROM-clause entry for table "t"
LINE 2: USING (SELECT * FROM source WHERE t.tid > sid) s
^
DETAIL: There is an entry for table "t", but it cannot be referenced from this part of the query.
--
-- initial tests
--
-- zero rows in source has no effect
MERGE INTO target
USING source
ON target.tid = source.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT DEFAULT VALUES;
ROLLBACK;
-- insert some non-matching source rows to work from
INSERT INTO source VALUES (4, 40);
SELECT * FROM source ORDER BY sid;
sid | delta
-----+-------
4 | 40
(1 row)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
DO NOTHING;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT DEFAULT VALUES;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
|
(4 rows)
ROLLBACK;
-- DELETE/INSERT not matched by source/target
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED BY SOURCE THEN
DELETE
WHEN NOT MATCHED BY TARGET THEN
INSERT VALUES (s.sid, s.delta)
RETURNING merge_action(), old, new, t.*;
merge_action | old | new | tid | balance
--------------+--------+--------+-----+---------
DELETE | (1,10) | | 1 | 10
DELETE | (2,20) | | 2 | 20
DELETE | (3,30) | | 3 | 30
INSERT | | (4,40) | 4 | 40
(4 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
4 | 40
(1 row)
ROLLBACK;
-- index plans
INSERT INTO target SELECT generate_series(1000,2500), 0;
ALTER TABLE target ADD PRIMARY KEY (tid);
ANALYZE target;
EXPLAIN (COSTS OFF)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
QUERY PLAN
----------------------------------------
Merge on target t
-> Hash Join
Hash Cond: (s.sid = t.tid)
-> Seq Scan on source s
-> Hash
-> Seq Scan on target t
(6 rows)
EXPLAIN (COSTS OFF)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
QUERY PLAN
----------------------------------------
Merge on target t
-> Hash Join
Hash Cond: (s.sid = t.tid)
-> Seq Scan on source s
-> Hash
-> Seq Scan on target t
(6 rows)
EXPLAIN (COSTS OFF)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (4, NULL);
QUERY PLAN
----------------------------------------
Merge on target t
-> Hash Left Join
Hash Cond: (s.sid = t.tid)
-> Seq Scan on source s
-> Hash
-> Seq Scan on target t
(6 rows)
DELETE FROM target WHERE tid > 100;
ANALYZE target;
-- insert some matching source rows to work from
INSERT INTO source VALUES (2, 5);
INSERT INTO source VALUES (3, 20);
SELECT * FROM source ORDER BY sid;
sid | delta
-----+-------
2 | 5
3 | 20
4 | 40
(3 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
-- equivalent of an UPDATE join
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 0
3 | 0
(3 rows)
ROLLBACK;
-- equivalent of a DELETE join
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
(1 row)
ROLLBACK;
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DO NOTHING;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
ROLLBACK;
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (4, NULL);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 |
(4 rows)
ROLLBACK;
-- duplicate source row causes multiple target row update ERROR
INSERT INTO source VALUES (2, 5);
SELECT * FROM source ORDER BY sid;
sid | delta
-----+-------
2 | 5
2 | 5
3 | 20
4 | 40
(4 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0;
ERROR: MERGE command cannot affect row a second time
HINT: Ensure that not more than one source row matches any one target row.
ROLLBACK;
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
DELETE;
ERROR: MERGE command cannot affect row a second time
HINT: Ensure that not more than one source row matches any one target row.
ROLLBACK;
-- remove duplicate MATCHED data from source data
DELETE FROM source WHERE sid = 2;
INSERT INTO source VALUES (2, 5);
SELECT * FROM source ORDER BY sid;
sid | delta
-----+-------
2 | 5
3 | 20
4 | 40
(3 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
-- duplicate source row on INSERT should fail because of target_pkey
INSERT INTO source VALUES (4, 40);
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (4, NULL);
ERROR: duplicate key value violates unique constraint "target_pkey"
DETAIL: Key (tid)=(4) already exists.
SELECT * FROM target ORDER BY tid;
ERROR: current transaction is aborted, commands ignored until end of transaction block
ROLLBACK;
-- remove duplicate NOT MATCHED data from source data
DELETE FROM source WHERE sid = 4;
INSERT INTO source VALUES (4, 40);
SELECT * FROM source ORDER BY sid;
sid | delta
-----+-------
2 | 5
3 | 20
4 | 40
(3 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
-- remove constraints
alter table target drop CONSTRAINT target_pkey;
alter table target alter column tid drop not null;
-- multiple actions
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (4, 4)
WHEN MATCHED THEN
UPDATE SET balance = 0;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 0
3 | 0
4 | 4
(4 rows)
ROLLBACK;
-- should be equivalent
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = 0
WHEN NOT MATCHED THEN
INSERT VALUES (4, 4);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 0
3 | 0
4 | 4
(4 rows)
ROLLBACK;
-- column references
-- do a simple equivalent of an UPDATE join
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = t.balance + s.delta;
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 25
3 | 50
(3 rows)
ROLLBACK;
-- do a simple equivalent of an INSERT SELECT
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (s.sid, s.delta);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
(4 rows)
ROLLBACK;
-- and again with duplicate source rows
INSERT INTO source VALUES (5, 50);
INSERT INTO source VALUES (5, 50);
-- do a simple equivalent of an INSERT SELECT
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (s.sid, s.delta);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
5 | 50
5 | 50
(6 rows)
ROLLBACK;
-- removing duplicate source rows
DELETE FROM source WHERE sid = 5;
-- and again with explicitly identified column list
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.delta);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
(4 rows)
ROLLBACK;
-- and again with a subtle error: referring to non-existent target row for NOT MATCHED
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (t.tid, s.delta);
ERROR: invalid reference to FROM-clause entry for table "t"
LINE 5: INSERT (tid, balance) VALUES (t.tid, s.delta);
^
DETAIL: There is an entry for table "t", but it cannot be referenced from this part of the query.
-- and again with a constant ON clause
BEGIN;
MERGE INTO target t
USING source AS s
ON (SELECT true)
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (t.tid, s.delta);
ERROR: invalid reference to FROM-clause entry for table "t"
LINE 5: INSERT (tid, balance) VALUES (t.tid, s.delta);
^
DETAIL: There is an entry for table "t", but it cannot be referenced from this part of the query.
SELECT * FROM target ORDER BY tid;
ERROR: current transaction is aborted, commands ignored until end of transaction block
ROLLBACK;
-- now the classic UPSERT
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = t.balance + s.delta
WHEN NOT MATCHED THEN
INSERT VALUES (s.sid, s.delta);
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 25
3 | 50
4 | 40
(4 rows)
ROLLBACK;
-- unreachable WHEN clause should ERROR
BEGIN;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED THEN /* Terminal WHEN clause for MATCHED */
DELETE
WHEN MATCHED THEN
UPDATE SET balance = t.balance - s.delta;
ERROR: unreachable WHEN clause specified after unconditional WHEN clause
ROLLBACK;
-- conditional WHEN clause
CREATE TABLE wq_target (tid integer not null, balance integer DEFAULT -1)
WITH (autovacuum_enabled=off);
CREATE TABLE wq_source (balance integer, sid integer)
WITH (autovacuum_enabled=off);
INSERT INTO wq_source (sid, balance) VALUES (1, 100);
BEGIN;
-- try a simple INSERT with default values first
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid) VALUES (s.sid);
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | -1
(1 row)
ROLLBACK;
-- this time with a FALSE condition
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED AND FALSE THEN
INSERT (tid) VALUES (s.sid);
SELECT * FROM wq_target;
tid | balance
-----+---------
(0 rows)
-- this time with an actual condition which returns false
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED AND s.balance <> 100 THEN
INSERT (tid) VALUES (s.sid);
SELECT * FROM wq_target;
tid | balance
-----+---------
(0 rows)
BEGIN;
-- and now with a condition which returns true
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED AND s.balance = 100 THEN
INSERT (tid) VALUES (s.sid);
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | -1
(1 row)
ROLLBACK;
-- conditions in the NOT MATCHED clause can only refer to source columns
BEGIN;
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED AND t.balance = 100 THEN
INSERT (tid) VALUES (s.sid);
ERROR: invalid reference to FROM-clause entry for table "t"
LINE 3: WHEN NOT MATCHED AND t.balance = 100 THEN
^
DETAIL: There is an entry for table "t", but it cannot be referenced from this part of the query.
SELECT * FROM wq_target;
ERROR: current transaction is aborted, commands ignored until end of transaction block
ROLLBACK;
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED AND s.balance = 100 THEN
INSERT (tid) VALUES (s.sid);
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | -1
(1 row)
-- conditions in NOT MATCHED BY SOURCE clause can only refer to target columns
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED BY SOURCE AND s.balance = 100 THEN
DELETE;
ERROR: invalid reference to FROM-clause entry for table "s"
LINE 3: WHEN NOT MATCHED BY SOURCE AND s.balance = 100 THEN
^
DETAIL: There is an entry for table "s", but it cannot be referenced from this part of the query.
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN NOT MATCHED BY SOURCE AND t.balance = 100 THEN
DELETE;
-- conditions in MATCHED clause can refer to both source and target
SELECT * FROM wq_source;
balance | sid
---------+-----
100 | 1
(1 row)
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND s.balance = 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 99
(1 row)
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance = 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 99
(1 row)
-- check if AND works
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance = 99 AND s.balance > 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 99
(1 row)
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance = 99 AND s.balance = 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 199
(1 row)
-- check if OR works
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance = 99 OR s.balance > 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 199
(1 row)
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance = 199 OR s.balance > 100 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 299
(1 row)
-- check source-side whole-row references
BEGIN;
MERGE INTO wq_target t
USING wq_source s ON (t.tid = s.sid)
WHEN matched and t = s or t.tid = s.sid THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 399
(1 row)
ROLLBACK;
-- check if subqueries work in the conditions?
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.balance > (SELECT max(balance) FROM target) THEN
UPDATE SET balance = t.balance + s.balance;
-- check if we can access system columns in the conditions
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.xmin = t.xmax THEN
UPDATE SET balance = t.balance + s.balance;
ERROR: cannot use system column "xmin" in MERGE WHEN condition
LINE 3: WHEN MATCHED AND t.xmin = t.xmax THEN
^
MERGE INTO wq_target t
USING wq_source s ON t.tid = s.sid
WHEN MATCHED AND t.tableoid >= 0 THEN
UPDATE SET balance = t.balance + s.balance;
SELECT * FROM wq_target;
tid | balance
-----+---------
1 | 499
(1 row)
DROP TABLE wq_target, wq_source;
-- test triggers
create or replace function merge_trigfunc () returns trigger
language plpgsql as
$$
DECLARE
line text;
BEGIN
SELECT INTO line format('%s %s %s trigger%s',
TG_WHEN, TG_OP, TG_LEVEL, CASE
WHEN TG_OP = 'INSERT' AND TG_LEVEL = 'ROW'
THEN format(' row: %s', NEW)
WHEN TG_OP = 'UPDATE' AND TG_LEVEL = 'ROW'
THEN format(' row: %s -> %s', OLD, NEW)
WHEN TG_OP = 'DELETE' AND TG_LEVEL = 'ROW'
THEN format(' row: %s', OLD)
END);
RAISE NOTICE '%', line;
IF (TG_WHEN = 'BEFORE' AND TG_LEVEL = 'ROW') THEN
IF (TG_OP = 'DELETE') THEN
RETURN OLD;
ELSE
RETURN NEW;
END IF;
ELSE
RETURN NULL;
END IF;
END;
$$;
CREATE TRIGGER merge_bsi BEFORE INSERT ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_bsu BEFORE UPDATE ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_bsd BEFORE DELETE ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_asi AFTER INSERT ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_asu AFTER UPDATE ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_asd AFTER DELETE ON target FOR EACH STATEMENT EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_bri BEFORE INSERT ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_bru BEFORE UPDATE ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_brd BEFORE DELETE ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_ari AFTER INSERT ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_aru AFTER UPDATE ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
CREATE TRIGGER merge_ard AFTER DELETE ON target FOR EACH ROW EXECUTE PROCEDURE merge_trigfunc ();
-- now the classic UPSERT, with a DELETE
BEGIN;
UPDATE target SET balance = 0 WHERE tid = 3;
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,0)
NOTICE: AFTER UPDATE ROW trigger row: (3,30) -> (3,0)
NOTICE: AFTER UPDATE STATEMENT trigger
--EXPLAIN (ANALYZE ON, COSTS OFF, SUMMARY OFF, TIMING OFF)
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
DELETE
WHEN NOT MATCHED THEN
INSERT VALUES (s.sid, s.delta);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE DELETE STATEMENT trigger
NOTICE: BEFORE DELETE ROW trigger row: (3,0)
NOTICE: BEFORE UPDATE ROW trigger row: (2,20) -> (2,15)
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: AFTER DELETE ROW trigger row: (3,0)
NOTICE: AFTER UPDATE ROW trigger row: (2,20) -> (2,15)
NOTICE: AFTER INSERT ROW trigger row: (4,40)
NOTICE: AFTER DELETE STATEMENT trigger
NOTICE: AFTER UPDATE STATEMENT trigger
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 15
4 | 40
(3 rows)
ROLLBACK;
-- UPSERT with UPDATE/DELETE when not matched by source
BEGIN;
DELETE FROM SOURCE WHERE sid = 2;
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
UPDATE SET balance = 0
WHEN NOT MATCHED THEN
INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED BY SOURCE AND tid = 1 THEN
UPDATE SET balance = 0
WHEN NOT MATCHED BY SOURCE THEN
DELETE
RETURNING merge_action(), old, new, t.*;
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE DELETE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,10)
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: BEFORE DELETE ROW trigger row: (2,20)
NOTICE: BEFORE UPDATE ROW trigger row: (1,10) -> (1,0)
NOTICE: AFTER UPDATE ROW trigger row: (3,30) -> (3,10)
NOTICE: AFTER INSERT ROW trigger row: (4,40)
NOTICE: AFTER DELETE ROW trigger row: (2,20)
NOTICE: AFTER UPDATE ROW trigger row: (1,10) -> (1,0)
NOTICE: AFTER DELETE STATEMENT trigger
NOTICE: AFTER UPDATE STATEMENT trigger
NOTICE: AFTER INSERT STATEMENT trigger
merge_action | old | new | tid | balance
--------------+--------+--------+-----+---------
UPDATE | (3,30) | (3,10) | 3 | 10
INSERT | | (4,40) | 4 | 40
DELETE | (2,20) | | 2 | 20
UPDATE | (1,10) | (1,0) | 1 | 0
(4 rows)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 0
3 | 10
4 | 40
(3 rows)
ROLLBACK;
-- Test behavior of triggers that turn UPDATE/DELETE into no-ops
create or replace function skip_merge_op() returns trigger
language plpgsql as
$$
BEGIN
RETURN NULL;
END;
$$;
SELECT * FROM target full outer join source on (sid = tid);
tid | balance | sid | delta
-----+---------+-----+-------
3 | 30 | 3 | 20
2 | 20 | 2 | 5
| | 4 | 40
1 | 10 | |
(4 rows)
create trigger merge_skip BEFORE INSERT OR UPDATE or DELETE
ON target FOR EACH ROW EXECUTE FUNCTION skip_merge_op();
DO $$
DECLARE
result integer;
BEGIN
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND s.sid = 3 THEN UPDATE SET balance = t.balance + s.delta
WHEN MATCHED THEN DELETE
WHEN NOT MATCHED THEN INSERT VALUES (sid, delta);
IF FOUND THEN
RAISE NOTICE 'Found';
ELSE
RAISE NOTICE 'Not found';
END IF;
GET DIAGNOSTICS result := ROW_COUNT;
RAISE NOTICE 'ROW_COUNT = %', result;
END;
$$;
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE DELETE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,50)
NOTICE: BEFORE DELETE ROW trigger row: (2,20)
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: AFTER DELETE STATEMENT trigger
NOTICE: AFTER UPDATE STATEMENT trigger
NOTICE: AFTER INSERT STATEMENT trigger
NOTICE: Not found
NOTICE: ROW_COUNT = 0
SELECT * FROM target FULL OUTER JOIN source ON (sid = tid);
tid | balance | sid | delta
-----+---------+-----+-------
3 | 30 | 3 | 20
2 | 20 | 2 | 5
| | 4 | 40
1 | 10 | |
(4 rows)
DROP TRIGGER merge_skip ON target;
DROP FUNCTION skip_merge_op();
-- test from PL/pgSQL
-- make sure MERGE INTO isn't interpreted to mean returning variables like SELECT INTO
BEGIN;
DO LANGUAGE plpgsql $$
BEGIN
MERGE INTO target t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta;
END;
$$;
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,10)
NOTICE: BEFORE UPDATE ROW trigger row: (2,20) -> (2,15)
NOTICE: AFTER UPDATE ROW trigger row: (3,30) -> (3,10)
NOTICE: AFTER UPDATE ROW trigger row: (2,20) -> (2,15)
NOTICE: AFTER UPDATE STATEMENT trigger
ROLLBACK;
--source constants
BEGIN;
MERGE INTO target t
USING (SELECT 9 AS sid, 57 AS delta) AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.delta);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE INSERT ROW trigger row: (9,57)
NOTICE: AFTER INSERT ROW trigger row: (9,57)
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
9 | 57
(4 rows)
ROLLBACK;
--source query
BEGIN;
MERGE INTO target t
USING (SELECT sid, delta FROM source WHERE delta > 0) AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.delta);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
(4 rows)
ROLLBACK;
BEGIN;
MERGE INTO target t
USING (SELECT sid, delta as newname FROM source WHERE delta > 0) AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.newname);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
(4 rows)
ROLLBACK;
--self-merge
BEGIN;
MERGE INTO target t1
USING target t2
ON t1.tid = t2.tid
WHEN MATCHED THEN
UPDATE SET balance = t1.balance + t2.balance
WHEN NOT MATCHED THEN
INSERT VALUES (t2.tid, t2.balance);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (1,10) -> (1,20)
NOTICE: BEFORE UPDATE ROW trigger row: (2,20) -> (2,40)
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,60)
NOTICE: AFTER UPDATE ROW trigger row: (1,10) -> (1,20)
NOTICE: AFTER UPDATE ROW trigger row: (2,20) -> (2,40)
NOTICE: AFTER UPDATE ROW trigger row: (3,30) -> (3,60)
NOTICE: AFTER UPDATE STATEMENT trigger
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 20
2 | 40
3 | 60
(3 rows)
ROLLBACK;
BEGIN;
MERGE INTO target t
USING (SELECT tid as sid, balance as delta FROM target WHERE balance > 0) AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.delta);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
(3 rows)
ROLLBACK;
BEGIN;
MERGE INTO target t
USING
(SELECT sid, max(delta) AS delta
FROM source
GROUP BY sid
HAVING count(*) = 1
ORDER BY sid ASC) AS s
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT (tid, balance) VALUES (s.sid, s.delta);
NOTICE: BEFORE INSERT STATEMENT trigger
NOTICE: BEFORE INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT ROW trigger row: (4,40)
NOTICE: AFTER INSERT STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 30
4 | 40
(4 rows)
ROLLBACK;
-- plpgsql parameters and results
BEGIN;
CREATE FUNCTION merge_func (p_id integer, p_bal integer)
RETURNS INTEGER
LANGUAGE plpgsql
AS $$
DECLARE
result integer;
BEGIN
MERGE INTO target t
USING (SELECT p_id AS sid) AS s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = t.balance - p_bal;
IF FOUND THEN
GET DIAGNOSTICS result := ROW_COUNT;
END IF;
RETURN result;
END;
$$;
SELECT merge_func(3, 4);
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (3,30) -> (3,26)
NOTICE: AFTER UPDATE ROW trigger row: (3,30) -> (3,26)
NOTICE: AFTER UPDATE STATEMENT trigger
merge_func
------------
1
(1 row)
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 10
2 | 20
3 | 26
(3 rows)
ROLLBACK;
-- PREPARE
BEGIN;
prepare foom as merge into target t using (select 1 as sid) s on (t.tid = s.sid) when matched then update set balance = 1;
execute foom;
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (1,10) -> (1,1)
NOTICE: AFTER UPDATE ROW trigger row: (1,10) -> (1,1)
NOTICE: AFTER UPDATE STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 1
2 | 20
3 | 30
(3 rows)
ROLLBACK;
BEGIN;
PREPARE foom2 (integer, integer) AS
MERGE INTO target t
USING (SELECT 1) s
ON t.tid = $1
WHEN MATCHED THEN
UPDATE SET balance = $2;
--EXPLAIN (ANALYZE ON, COSTS OFF, SUMMARY OFF, TIMING OFF)
execute foom2 (1, 1);
NOTICE: BEFORE UPDATE STATEMENT trigger
NOTICE: BEFORE UPDATE ROW trigger row: (1,10) -> (1,1)
NOTICE: AFTER UPDATE ROW trigger row: (1,10) -> (1,1)
NOTICE: AFTER UPDATE STATEMENT trigger
SELECT * FROM target ORDER BY tid;
tid | balance
-----+---------
1 | 1
2 | 20
3 | 30
(3 rows)
ROLLBACK;
-- subqueries in source relation
CREATE TABLE sq_target (tid integer NOT NULL, balance integer)
WITH (autovacuum_enabled=off);
CREATE TABLE sq_source (delta integer, sid integer, balance integer DEFAULT 0)
WITH (autovacuum_enabled=off);
INSERT INTO sq_target(tid, balance) VALUES (1,100), (2,200), (3,300);
INSERT INTO sq_source(sid, delta) VALUES (1,10), (2,20), (4,40);
BEGIN;
MERGE INTO sq_target t
USING (SELECT * FROM sq_source) s
ON tid = sid
WHEN MATCHED AND t.balance > delta THEN
UPDATE SET balance = t.balance + delta;
SELECT * FROM sq_target;
tid | balance
-----+---------
3 | 300
1 | 110
2 | 220
(3 rows)
ROLLBACK;
-- try a view
CREATE VIEW v AS SELECT * FROM sq_source WHERE sid < 2;
BEGIN;
MERGE INTO sq_target
USING v
ON tid = sid
WHEN MATCHED THEN
UPDATE SET balance = v.balance + delta;
SELECT * FROM sq_target;
tid | balance
-----+---------
2 | 200
3 | 300
1 | 10
(3 rows)
ROLLBACK;
-- ambiguous reference to a column
BEGIN;
MERGE INTO sq_target
USING v
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE;
ERROR: column reference "balance" is ambiguous
LINE 5: UPDATE SET balance = balance + delta
^
ROLLBACK;
BEGIN;
INSERT INTO sq_source (sid, balance, delta) VALUES (-1, -1, -10);
MERGE INTO sq_target t
USING v
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE;
SELECT * FROM sq_target;
tid | balance
-----+---------
2 | 200
3 | 300
-1 | -11
(3 rows)
ROLLBACK;
-- CTEs
BEGIN;
INSERT INTO sq_source (sid, balance, delta) VALUES (-1, -1, -10);
WITH targq AS (
SELECT * FROM v
)
MERGE INTO sq_target t
USING v
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE;
ROLLBACK;
-- RETURNING
SELECT * FROM sq_source ORDER BY sid;
delta | sid | balance
-------+-----+---------
10 | 1 | 0
20 | 2 | 0
40 | 4 | 0
(3 rows)
SELECT * FROM sq_target ORDER BY tid;
tid | balance
-----+---------
1 | 100
2 | 200
3 | 300
(3 rows)
BEGIN;
CREATE TABLE merge_actions(action text, abbrev text);
INSERT INTO merge_actions VALUES ('INSERT', 'ins'), ('UPDATE', 'upd'), ('DELETE', 'del');
MERGE INTO sq_target t
USING sq_source s
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING (SELECT abbrev FROM merge_actions
WHERE action = merge_action()) AS action,
old.tid AS old_tid, old.balance AS old_balance,
new.tid AS new_tid, new.balance AS new_balance,
(SELECT new.balance - old.balance AS delta_balance), t.*,
CASE merge_action()
WHEN 'INSERT' THEN 'Inserted '||t
WHEN 'UPDATE' THEN 'Added '||delta||' to balance'
WHEN 'DELETE' THEN 'Removed '||t
END AS description;
action | old_tid | old_balance | new_tid | new_balance | delta_balance | tid | balance | description
--------+---------+-------------+---------+-------------+---------------+-----+---------+---------------------
del | 1 | 100 | | | | 1 | 100 | Removed (1,100)
upd | 2 | 200 | 2 | 220 | 20 | 2 | 220 | Added 20 to balance
ins | | | 4 | 40 | | 4 | 40 | Inserted (4,40)
(3 rows)
ROLLBACK;
-- error when using merge_action() outside MERGE
SELECT merge_action() FROM sq_target;
ERROR: MERGE_ACTION() can only be used in the RETURNING list of a MERGE command
LINE 1: SELECT merge_action() FROM sq_target;
^
UPDATE sq_target SET balance = balance + 1 RETURNING merge_action();
ERROR: MERGE_ACTION() can only be used in the RETURNING list of a MERGE command
LINE 1: ...ATE sq_target SET balance = balance + 1 RETURNING merge_acti...
^
-- RETURNING in CTEs
CREATE TABLE sq_target_merge_log (tid integer NOT NULL, last_change text);
INSERT INTO sq_target_merge_log VALUES (1, 'Original value');
BEGIN;
WITH m AS (
MERGE INTO sq_target t
USING sq_source s
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING merge_action() AS action, old AS old_data, new AS new_data, t.*,
CASE merge_action()
WHEN 'INSERT' THEN 'Inserted '||t
WHEN 'UPDATE' THEN 'Added '||delta||' to balance'
WHEN 'DELETE' THEN 'Removed '||t
END AS description
), m2 AS (
MERGE INTO sq_target_merge_log l
USING m
ON l.tid = m.tid
WHEN MATCHED THEN
UPDATE SET last_change = description
WHEN NOT MATCHED THEN
INSERT VALUES (m.tid, description)
RETURNING m.*, merge_action() AS log_action, old AS old_log, new AS new_log, l.*
)
SELECT * FROM m2;
action | old_data | new_data | tid | balance | description | log_action | old_log | new_log | tid | last_change
--------+----------+----------+-----+---------+---------------------+------------+----------------------+---------------------------+-----+---------------------
DELETE | (1,100) | | 1 | 100 | Removed (1,100) | UPDATE | (1,"Original value") | (1,"Removed (1,100)") | 1 | Removed (1,100)
UPDATE | (2,200) | (2,220) | 2 | 220 | Added 20 to balance | INSERT | | (2,"Added 20 to balance") | 2 | Added 20 to balance
INSERT | | (4,40) | 4 | 40 | Inserted (4,40) | INSERT | | (4,"Inserted (4,40)") | 4 | Inserted (4,40)
(3 rows)
SELECT * FROM sq_target_merge_log ORDER BY tid;
tid | last_change
-----+---------------------
1 | Removed (1,100)
2 | Added 20 to balance
4 | Inserted (4,40)
(3 rows)
ROLLBACK;
-- COPY (MERGE ... RETURNING) TO ...
BEGIN;
COPY (
MERGE INTO sq_target t
USING sq_source s
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING merge_action(), old.*, new.*
) TO stdout;
DELETE 1 100 \N \N
UPDATE 2 200 2 220
INSERT \N \N 4 40
ROLLBACK;
-- SQL function with MERGE ... RETURNING
BEGIN;
CREATE FUNCTION merge_into_sq_target(sid int, balance int, delta int,
OUT action text, OUT tid int, OUT new_balance int)
LANGUAGE sql AS
$$
MERGE INTO sq_target t
USING (VALUES ($1, $2, $3)) AS v(sid, balance, delta)
ON tid = v.sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + v.delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (v.balance + v.delta, v.sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING merge_action(), t.*;
$$;
SELECT m.*
FROM (VALUES (1, 0, 0), (3, 0, 20), (4, 100, 10)) AS v(sid, balance, delta),
LATERAL (SELECT action, tid, new_balance FROM merge_into_sq_target(sid, balance, delta)) m;
action | tid | new_balance
--------+-----+-------------
DELETE | 1 | 100
UPDATE | 3 | 320
INSERT | 4 | 110
(3 rows)
ROLLBACK;
-- SQL SRF with MERGE ... RETURNING
BEGIN;
CREATE FUNCTION merge_sq_source_into_sq_target()
RETURNS TABLE (action text, tid int, balance int)
LANGUAGE sql AS
$$
MERGE INTO sq_target t
USING sq_source s
ON tid = sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (balance + delta, sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING merge_action(), t.*;
$$;
SELECT * FROM merge_sq_source_into_sq_target();
action | tid | balance
--------+-----+---------
DELETE | 1 | 100
UPDATE | 2 | 220
INSERT | 4 | 40
(3 rows)
ROLLBACK;
-- PL/pgSQL function with MERGE ... RETURNING ... INTO
BEGIN;
CREATE FUNCTION merge_into_sq_target(sid int, balance int, delta int,
OUT r_action text, OUT r_tid int, OUT r_balance int)
LANGUAGE plpgsql AS
$$
BEGIN
MERGE INTO sq_target t
USING (VALUES ($1, $2, $3)) AS v(sid, balance, delta)
ON tid = v.sid
WHEN MATCHED AND tid >= 2 THEN
UPDATE SET balance = t.balance + v.delta
WHEN NOT MATCHED THEN
INSERT (balance, tid) VALUES (v.balance + v.delta, v.sid)
WHEN MATCHED AND tid < 2 THEN
DELETE
RETURNING merge_action(), t.* INTO r_action, r_tid, r_balance;
END;
$$;
SELECT m.*
FROM (VALUES (1, 0, 0), (3, 0, 20), (4, 100, 10)) AS v(sid, balance, delta),
LATERAL (SELECT r_action, r_tid, r_balance FROM merge_into_sq_target(sid, balance, delta)) m;
r_action | r_tid | r_balance
----------+-------+-----------
DELETE | 1 | 100
UPDATE | 3 | 320
INSERT | 4 | 110
(3 rows)
ROLLBACK;
-- EXPLAIN
CREATE TABLE ex_mtarget (a int, b int)
WITH (autovacuum_enabled=off);
CREATE TABLE ex_msource (a int, b int)
WITH (autovacuum_enabled=off);
INSERT INTO ex_mtarget SELECT i, i*10 FROM generate_series(1,100,2) i;
INSERT INTO ex_msource SELECT i, i*10 FROM generate_series(1,100,1) i;
CREATE FUNCTION explain_merge(query text) RETURNS SETOF text
LANGUAGE plpgsql AS
$$
DECLARE ln text;
BEGIN
FOR ln IN
EXECUTE 'explain (analyze, timing off, summary off, costs off, buffers off) ' ||
query
LOOP
ln := regexp_replace(ln, '(Memory( Usage)?|Buckets|Batches): \S*', '\1: xxx', 'g');
RETURN NEXT ln;
END LOOP;
END;
$$;
-- only updates
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN MATCHED THEN
UPDATE SET b = t.b + 1');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: updated=50
-> Merge Join (actual rows=50.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=50.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=50.00 loops=1)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
(12 rows)
-- only updates to selected tuples
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN MATCHED AND t.a < 10 THEN
UPDATE SET b = t.b + 1');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: updated=5 skipped=45
-> Merge Join (actual rows=50.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=50.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=50.00 loops=1)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
(12 rows)
-- updates + deletes
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN MATCHED AND t.a < 10 THEN
UPDATE SET b = t.b + 1
WHEN MATCHED AND t.a >= 10 AND t.a <= 20 THEN
DELETE');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: updated=5 deleted=5 skipped=40
-> Merge Join (actual rows=50.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=50.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=50.00 loops=1)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
(12 rows)
-- only inserts
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN NOT MATCHED AND s.a < 10 THEN
INSERT VALUES (a, b)');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: inserted=4 skipped=96
-> Merge Left Join (actual rows=100.00 loops=1)
Merge Cond: (s.a = t.a)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
-> Sort (actual rows=45.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=45.00 loops=1)
(12 rows)
-- all three
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN MATCHED AND t.a < 10 THEN
UPDATE SET b = t.b + 1
WHEN MATCHED AND t.a >= 30 AND t.a <= 40 THEN
DELETE
WHEN NOT MATCHED AND s.a < 20 THEN
INSERT VALUES (a, b)');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: inserted=10 updated=9 deleted=5 skipped=76
-> Merge Left Join (actual rows=100.00 loops=1)
Merge Cond: (s.a = t.a)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
-> Sort (actual rows=49.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=49.00 loops=1)
(12 rows)
-- not matched by source
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN NOT MATCHED BY SOURCE and t.a < 10 THEN
DELETE');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: skipped=54
-> Merge Left Join (actual rows=54.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=54.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=54.00 loops=1)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
(12 rows)
-- not matched by source and target
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a
WHEN NOT MATCHED BY SOURCE AND t.a < 10 THEN
DELETE
WHEN NOT MATCHED BY TARGET AND s.a < 20 THEN
INSERT VALUES (a, b)');
explain_merge
-------------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
Tuples: skipped=100
-> Merge Full Join (actual rows=100.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=54.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=54.00 loops=1)
-> Sort (actual rows=100.00 loops=1)
Sort Key: s.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_msource s (actual rows=100.00 loops=1)
(12 rows)
-- nothing
SELECT explain_merge('
MERGE INTO ex_mtarget t USING ex_msource s ON t.a = s.a AND t.a < -1000
WHEN MATCHED AND t.a < 10 THEN
DO NOTHING');
explain_merge
-----------------------------------------------------------------------
Merge on ex_mtarget t (actual rows=0.00 loops=1)
-> Merge Join (actual rows=0.00 loops=1)
Merge Cond: (t.a = s.a)
-> Sort (actual rows=0.00 loops=1)
Sort Key: t.a
Sort Method: quicksort Memory: xxx
-> Seq Scan on ex_mtarget t (actual rows=0.00 loops=1)
Filter: (a < '-1000'::integer)
Rows Removed by Filter: 54
-> Sort (never executed)
Sort Key: s.a
-> Seq Scan on ex_msource s (never executed)
(12 rows)
DROP TABLE ex_msource, ex_mtarget;
DROP FUNCTION explain_merge(text);
-- EXPLAIN SubPlans and InitPlans
CREATE TABLE src (a int, b int, c int, d int);
CREATE TABLE tgt (a int, b int, c int, d int);
CREATE TABLE ref (ab int, cd int);
EXPLAIN (verbose, costs off)
MERGE INTO tgt t
USING (SELECT *, (SELECT count(*) FROM ref r
WHERE r.ab = s.a + s.b
AND r.cd = s.c - s.d) cnt
FROM src s) s
ON t.a = s.a AND t.b < s.cnt
WHEN MATCHED AND t.c > s.cnt THEN
UPDATE SET (b, c) = (SELECT s.b, s.cnt);
QUERY PLAN
-------------------------------------------------------------------------------------
Merge on public.tgt t
-> Hash Join
Output: t.ctid, s.a, s.b, s.c, s.d, s.ctid
Hash Cond: (t.a = s.a)
Join Filter: (t.b < (SubPlan 1))
-> Seq Scan on public.tgt t
Output: t.ctid, t.a, t.b
-> Hash
Output: s.a, s.b, s.c, s.d, s.ctid
-> Seq Scan on public.src s
Output: s.a, s.b, s.c, s.d, s.ctid
SubPlan 1
-> Aggregate
Output: count(*)
-> Seq Scan on public.ref r
Output: r.ab, r.cd
Filter: ((r.ab = (s.a + s.b)) AND (r.cd = (s.c - s.d)))
SubPlan 4
-> Aggregate
Output: count(*)
-> Seq Scan on public.ref r_2
Output: r_2.ab, r_2.cd
Filter: ((r_2.ab = (s.a + s.b)) AND (r_2.cd = (s.c - s.d)))
SubPlan 3
-> Result
Output: s.b, (InitPlan 2).col1
InitPlan 2
-> Aggregate
Output: count(*)
-> Seq Scan on public.ref r_1
Output: r_1.ab, r_1.cd
Filter: ((r_1.ab = (s.a + s.b)) AND (r_1.cd = (s.c - s.d)))
(32 rows)
DROP TABLE src, tgt, ref;
-- Subqueries
BEGIN;
MERGE INTO sq_target t
USING v
ON tid = sid
WHEN MATCHED THEN
UPDATE SET balance = (SELECT count(*) FROM sq_target);
SELECT * FROM sq_target WHERE tid = 1;
tid | balance
-----+---------
1 | 3
(1 row)
ROLLBACK;
BEGIN;
MERGE INTO sq_target t
USING v
ON tid = sid
WHEN MATCHED AND (SELECT count(*) > 0 FROM sq_target) THEN
UPDATE SET balance = 42;
SELECT * FROM sq_target WHERE tid = 1;
tid | balance
-----+---------
1 | 42
(1 row)
ROLLBACK;
BEGIN;
MERGE INTO sq_target t
USING v
ON tid = sid AND (SELECT count(*) > 0 FROM sq_target)
WHEN MATCHED THEN
UPDATE SET balance = 42;
SELECT * FROM sq_target WHERE tid = 1;
tid | balance
-----+---------
1 | 42
(1 row)
ROLLBACK;
DROP TABLE sq_target, sq_target_merge_log, sq_source CASCADE;
NOTICE: drop cascades to view v
CREATE TABLE pa_target (tid integer, balance float, val text)
PARTITION BY LIST (tid);
CREATE TABLE part1 PARTITION OF pa_target FOR VALUES IN (1,4)
WITH (autovacuum_enabled=off);
CREATE TABLE part2 PARTITION OF pa_target FOR VALUES IN (2,5,6)
WITH (autovacuum_enabled=off);
CREATE TABLE part3 PARTITION OF pa_target FOR VALUES IN (3,8,9)
WITH (autovacuum_enabled=off);
CREATE TABLE part4 PARTITION OF pa_target DEFAULT
WITH (autovacuum_enabled=off);
CREATE TABLE pa_source (sid integer, delta float);
-- insert many rows to the source table
INSERT INTO pa_source SELECT id, id * 10 FROM generate_series(1,14) AS id;
-- insert a few rows in the target table (odd numbered tid)
INSERT INTO pa_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
-- try simple MERGE
BEGIN;
MERGE INTO pa_target t
USING pa_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 pa_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 pa_target t
USING pa_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 pa_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;
-- try updating the partition key column
BEGIN;
CREATE FUNCTION merge_func() RETURNS integer LANGUAGE plpgsql AS $$
DECLARE
result integer;
BEGIN
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET tid = tid + 1, balance = balance + delta, val = val || ' updated by merge'
WHEN NOT MATCHED THEN
INSERT VALUES (sid, delta, 'inserted by merge')
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET tid = 1, val = val || ' not matched by source';
IF FOUND THEN
GET DIAGNOSTICS result := ROW_COUNT;
END IF;
RETURN result;
END;
$$;
SELECT merge_func();
merge_func
------------
15
(1 row)
SELECT * FROM pa_target ORDER BY tid, val;
tid | balance | val
-----+---------+-------------------------------
1 | 1500 | initial not matched by source
2 | 110 | initial updated by merge
2 | 20 | inserted by merge
4 | 330 | initial updated by merge
4 | 40 | inserted by merge
6 | 550 | initial updated by merge
6 | 60 | inserted by merge
8 | 770 | initial updated by merge
8 | 80 | inserted by merge
10 | 990 | initial updated by merge
10 | 100 | inserted by merge
12 | 1210 | initial updated by merge
12 | 120 | inserted by merge
14 | 1430 | initial updated by merge
14 | 140 | inserted by merge
(15 rows)
ROLLBACK;
-- update partition key to partition not initially scanned
BEGIN;
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid AND t.tid = 1
WHEN MATCHED THEN
UPDATE SET tid = tid + 1, balance = balance + delta, val = val || ' updated by merge'
RETURNING merge_action(), old, new, t.*;
merge_action | old | new | tid | balance | val
--------------+-----------------+------------------------------------+-----+---------+--------------------------
UPDATE | (1,100,initial) | (2,110,"initial updated by merge") | 2 | 110 | initial updated by merge
(1 row)
SELECT * FROM pa_target ORDER BY tid;
tid | balance | val
-----+---------+--------------------------
2 | 110 | initial updated by merge
3 | 300 | initial
5 | 500 | initial
7 | 700 | initial
9 | 900 | initial
11 | 1100 | initial
13 | 1300 | initial
15 | 1500 | initial
(8 rows)
ROLLBACK;
-- bug #18871: ExecInitPartitionInfo()'s handling of DO NOTHING actions
BEGIN;
TRUNCATE pa_target;
MERGE INTO pa_target t
USING (VALUES (10, 100)) AS s(sid, delta)
ON t.tid = s.sid
WHEN NOT MATCHED THEN
INSERT VALUES (1, 10, 'inserted by merge')
WHEN MATCHED THEN
DO NOTHING;
SELECT * FROM pa_target ORDER BY tid, val;
tid | balance | val
-----+---------+-------------------
1 | 10 | inserted by merge
(1 row)
ROLLBACK;
DROP TABLE pa_target CASCADE;
-- The target table is partitioned in the same way, but this time by attaching
-- partitions which have columns in different order, dropped columns etc.
CREATE TABLE pa_target (tid integer, balance float, val text)
PARTITION BY LIST (tid);
CREATE TABLE part1 (tid integer, balance float, val text)
WITH (autovacuum_enabled=off);
CREATE TABLE part2 (balance float, tid integer, val text)
WITH (autovacuum_enabled=off);
CREATE TABLE part3 (tid integer, balance float, val text)
WITH (autovacuum_enabled=off);
CREATE TABLE part4 (extraid text, tid integer, balance float, val text)
WITH (autovacuum_enabled=off);
ALTER TABLE part4 DROP COLUMN extraid;
ALTER TABLE pa_target ATTACH PARTITION part1 FOR VALUES IN (1,4);
ALTER TABLE pa_target ATTACH PARTITION part2 FOR VALUES IN (2,5,6);
ALTER TABLE pa_target ATTACH PARTITION part3 FOR VALUES IN (3,8,9);
ALTER TABLE pa_target ATTACH PARTITION part4 DEFAULT;
-- insert a few rows in the target table (odd numbered tid)
INSERT INTO pa_target SELECT id, id * 100, 'initial' FROM generate_series(1,15,2) AS id;
-- try simple MERGE
BEGIN;
DO $$
DECLARE
result integer;
BEGIN
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET balance = balance + delta, val = val || ' updated by merge'
WHEN NOT MATCHED THEN
INSERT VALUES (sid, delta, 'inserted by merge')
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET val = val || ' not matched by source';
GET DIAGNOSTICS result := ROW_COUNT;
RAISE NOTICE 'ROW_COUNT = %', result;
END;
$$;
NOTICE: ROW_COUNT = 15
SELECT * FROM pa_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 pa_target t
USING pa_source s
ON t.tid = s.sid AND tid IN (1, 5)
WHEN MATCHED AND tid % 5 = 0 THEN DELETE
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 pa_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
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
(19 rows)
ROLLBACK;
-- try updating the partition key column
BEGIN;
DO $$
DECLARE
result integer;
BEGIN
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET tid = tid + 1, balance = balance + delta, val = val || ' updated by merge'
WHEN NOT MATCHED THEN
INSERT VALUES (sid, delta, 'inserted by merge')
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET tid = 1, val = val || ' not matched by source';
GET DIAGNOSTICS result := ROW_COUNT;
RAISE NOTICE 'ROW_COUNT = %', result;
END;
$$;
NOTICE: ROW_COUNT = 15
SELECT * FROM pa_target ORDER BY tid, val;
tid | balance | val
-----+---------+-------------------------------
1 | 1500 | initial not matched by source
2 | 110 | initial updated by merge
2 | 20 | inserted by merge
4 | 330 | initial updated by merge
4 | 40 | inserted by merge
6 | 550 | initial updated by merge
6 | 60 | inserted by merge
8 | 770 | initial updated by merge
8 | 80 | inserted by merge
10 | 990 | initial updated by merge
10 | 100 | inserted by merge
12 | 1210 | initial updated by merge
12 | 120 | inserted by merge
14 | 1430 | initial updated by merge
14 | 140 | inserted by merge
(15 rows)
ROLLBACK;
-- as above, but blocked by BEFORE DELETE ROW trigger
BEGIN;
CREATE FUNCTION trig_fn() RETURNS trigger LANGUAGE plpgsql AS
$$ BEGIN RETURN NULL; END; $$;
CREATE TRIGGER del_trig BEFORE DELETE ON pa_target
FOR EACH ROW EXECUTE PROCEDURE trig_fn();
DO $$
DECLARE
result integer;
BEGIN
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET tid = tid + 1, balance = balance + delta, val = val || ' updated by merge'
WHEN NOT MATCHED THEN
INSERT VALUES (sid, delta, 'inserted by merge')
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET val = val || ' not matched by source';
GET DIAGNOSTICS result := ROW_COUNT;
RAISE NOTICE 'ROW_COUNT = %', result;
END;
$$;
NOTICE: ROW_COUNT = 11
SELECT * FROM pa_target ORDER BY tid, val;
tid | balance | val
-----+---------+-------------------------------
1 | 100 | initial
2 | 20 | inserted by merge
3 | 300 | initial
4 | 40 | inserted by merge
6 | 550 | initial updated by merge
6 | 60 | inserted by merge
7 | 700 | initial
8 | 80 | inserted by merge
9 | 900 | initial
10 | 100 | inserted by merge
12 | 1210 | initial updated by merge
12 | 120 | inserted by merge
14 | 1430 | initial updated by merge
14 | 140 | inserted by merge
15 | 1500 | initial not matched by source
(15 rows)
ROLLBACK;
-- as above, but blocked by BEFORE INSERT ROW trigger
BEGIN;
CREATE FUNCTION trig_fn() RETURNS trigger LANGUAGE plpgsql AS
$$ BEGIN RETURN NULL; END; $$;
CREATE TRIGGER ins_trig BEFORE INSERT ON pa_target
FOR EACH ROW EXECUTE PROCEDURE trig_fn();
DO $$
DECLARE
result integer;
BEGIN
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid
WHEN MATCHED THEN
UPDATE SET tid = tid + 1, balance = balance + delta, val = val || ' updated by merge'
WHEN NOT MATCHED THEN
INSERT VALUES (sid, delta, 'inserted by merge')
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET val = val || ' not matched by source';
GET DIAGNOSTICS result := ROW_COUNT;
RAISE NOTICE 'ROW_COUNT = %', result;
END;
$$;
NOTICE: ROW_COUNT = 4
SELECT * FROM pa_target ORDER BY tid, val;
tid | balance | val
-----+---------+-------------------------------
6 | 550 | initial updated by merge
12 | 1210 | initial updated by merge
14 | 1430 | initial updated by merge
15 | 1500 | initial not matched by source
(4 rows)
ROLLBACK;
-- test RLS enforcement
BEGIN;
ALTER TABLE pa_target ENABLE ROW LEVEL SECURITY;
ALTER TABLE pa_target FORCE ROW LEVEL SECURITY;
CREATE POLICY pa_target_pol ON pa_target USING (tid != 0);
MERGE INTO pa_target t
USING pa_source s
ON t.tid = s.sid AND t.tid IN (1,2,3,4)
WHEN MATCHED THEN
UPDATE SET tid = tid - 1;
ERROR: new row violates row-level security policy for table "pa_target"
ROLLBACK;
DROP TABLE pa_source;
DROP TABLE pa_target CASCADE;
-- Sub-partitioning
CREATE TABLE pa_target (logts timestamp, tid integer, balance float, val text)
PARTITION BY RANGE (logts);
CREATE TABLE part_m01 PARTITION OF pa_target
FOR VALUES FROM ('2017-01-01') TO ('2017-02-01')
PARTITION BY LIST (tid);
CREATE TABLE part_m01_odd PARTITION OF part_m01
FOR VALUES IN (1,3,5,7,9) WITH (autovacuum_enabled=off);
CREATE TABLE part_m01_even PARTITION OF part_m01
FOR VALUES IN (2,4,6,8) WITH (autovacuum_enabled=off);
CREATE TABLE part_m02 PARTITION OF pa_target
FOR VALUES FROM ('2017-02-01') TO ('2017-03-01')
PARTITION BY LIST (tid);
CREATE TABLE part_m02_odd PARTITION OF part_m02
FOR VALUES IN (1,3,5,7,9) WITH (autovacuum_enabled=off);
CREATE TABLE part_m02_even PARTITION OF part_m02
FOR VALUES IN (2,4,6,8) WITH (autovacuum_enabled=off);
CREATE TABLE pa_source (sid integer, delta float)
WITH (autovacuum_enabled=off);
-- insert many rows to the source table
INSERT INTO pa_source SELECT id, id * 10 FROM generate_series(1,14) AS id;
-- insert a few rows in the target table (odd numbered tid)
INSERT INTO pa_target SELECT '2017-01-31', id, id * 100, 'initial' FROM generate_series(1,9,3) AS id;
INSERT INTO pa_target SELECT '2017-02-28', id, id * 100, 'initial' FROM generate_series(2,9,3) AS id;
-- try simple MERGE
BEGIN;
MERGE INTO pa_target t
USING (SELECT '2017-01-15' AS slogts, * FROM pa_source WHERE sid < 10) 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 (slogts::timestamp, sid, delta, 'inserted by merge')
RETURNING merge_action(), old, new, t.*;
merge_action | old | new | logts | tid | balance | val
--------------+--------------------------------------------+---------------------------------------------------------------+--------------------------+-----+---------+--------------------------
UPDATE | ("Tue Jan 31 00:00:00 2017",1,100,initial) | ("Tue Jan 31 00:00:00 2017",1,110,"initial updated by merge") | Tue Jan 31 00:00:00 2017 | 1 | 110 | initial updated by merge
UPDATE | ("Tue Feb 28 00:00:00 2017",2,200,initial) | ("Tue Feb 28 00:00:00 2017",2,220,"initial updated by merge") | Tue Feb 28 00:00:00 2017 | 2 | 220 | initial updated by merge
INSERT | | ("Sun Jan 15 00:00:00 2017",3,30,"inserted by merge") | Sun Jan 15 00:00:00 2017 | 3 | 30 | inserted by merge
UPDATE | ("Tue Jan 31 00:00:00 2017",4,400,initial) | ("Tue Jan 31 00:00:00 2017",4,440,"initial updated by merge") | Tue Jan 31 00:00:00 2017 | 4 | 440 | initial updated by merge
UPDATE | ("Tue Feb 28 00:00:00 2017",5,500,initial) | ("Tue Feb 28 00:00:00 2017",5,550,"initial updated by merge") | Tue Feb 28 00:00:00 2017 | 5 | 550 | initial updated by merge
INSERT | | ("Sun Jan 15 00:00:00 2017",6,60,"inserted by merge") | Sun Jan 15 00:00:00 2017 | 6 | 60 | inserted by merge
UPDATE | ("Tue Jan 31 00:00:00 2017",7,700,initial) | ("Tue Jan 31 00:00:00 2017",7,770,"initial updated by merge") | Tue Jan 31 00:00:00 2017 | 7 | 770 | initial updated by merge
UPDATE | ("Tue Feb 28 00:00:00 2017",8,800,initial) | ("Tue Feb 28 00:00:00 2017",8,880,"initial updated by merge") | Tue Feb 28 00:00:00 2017 | 8 | 880 | initial updated by merge
INSERT | | ("Sun Jan 15 00:00:00 2017",9,90,"inserted by merge") | Sun Jan 15 00:00:00 2017 | 9 | 90 | inserted by merge
(9 rows)
SELECT * FROM pa_target ORDER BY tid;
logts | tid | balance | val
--------------------------+-----+---------+--------------------------
Tue Jan 31 00:00:00 2017 | 1 | 110 | initial updated by merge
Tue Feb 28 00:00:00 2017 | 2 | 220 | initial updated by merge
Sun Jan 15 00:00:00 2017 | 3 | 30 | inserted by merge
Tue Jan 31 00:00:00 2017 | 4 | 440 | initial updated by merge
Tue Feb 28 00:00:00 2017 | 5 | 550 | initial updated by merge
Sun Jan 15 00:00:00 2017 | 6 | 60 | inserted by merge
Tue Jan 31 00:00:00 2017 | 7 | 770 | initial updated by merge
Tue Feb 28 00:00:00 2017 | 8 | 880 | initial updated by merge
Sun Jan 15 00:00:00 2017 | 9 | 90 | inserted by merge
(9 rows)
ROLLBACK;
DROP TABLE pa_source;
DROP TABLE pa_target CASCADE;
-- Partitioned table with primary key
CREATE TABLE pa_target (tid integer PRIMARY KEY) PARTITION BY LIST (tid);
CREATE TABLE pa_targetp PARTITION OF pa_target DEFAULT;
CREATE TABLE pa_source (sid integer);
INSERT INTO pa_source VALUES (1), (2);
EXPLAIN (VERBOSE, COSTS OFF)
MERGE INTO pa_target t USING pa_source s ON t.tid = s.sid
WHEN NOT MATCHED THEN INSERT VALUES (s.sid);
QUERY PLAN
-------------------------------------------------------------
Merge on public.pa_target t
Merge on public.pa_targetp t_1
-> Hash Left Join
Output: s.sid, s.ctid, t_1.tableoid, t_1.ctid
Inner Unique: true
Hash Cond: (s.sid = t_1.tid)
-> Seq Scan on public.pa_source s
Output: s.sid, s.ctid
-> Hash
Output: t_1.tid, t_1.tableoid, t_1.ctid
-> Seq Scan on public.pa_targetp t_1
Output: t_1.tid, t_1.tableoid, t_1.ctid
(12 rows)
MERGE INTO pa_target t USING pa_source s ON t.tid = s.sid
WHEN NOT MATCHED THEN INSERT VALUES (s.sid);
TABLE pa_target;
tid
-----
1
2
(2 rows)
-- Partition-less partitioned table
-- (the bug we are checking for appeared only if table had partitions before)
DROP TABLE pa_targetp;
EXPLAIN (VERBOSE, COSTS OFF)
MERGE INTO pa_target t USING pa_source s ON t.tid = s.sid
WHEN NOT MATCHED THEN INSERT VALUES (s.sid);
QUERY PLAN
--------------------------------------------
Merge on public.pa_target t
-> Hash Left Join
Output: s.sid, s.ctid, t.ctid
Inner Unique: true
Hash Cond: (s.sid = t.tid)
-> Seq Scan on public.pa_source s
Output: s.sid, s.ctid
-> Hash
Output: t.tid, t.ctid
-> Result
Output: t.tid, t.ctid
One-Time Filter: false
(12 rows)
MERGE INTO pa_target t USING pa_source s ON t.tid = s.sid
WHEN NOT MATCHED THEN INSERT VALUES (s.sid);
ERROR: no partition of relation "pa_target" found for row
DETAIL: Partition key of the failing row contains (tid) = (1).
DROP TABLE pa_source;
DROP TABLE pa_target CASCADE;
-- some complex joins on the source side
CREATE TABLE cj_target (tid integer, balance float, val text)
WITH (autovacuum_enabled=off);
CREATE TABLE cj_source1 (sid1 integer, scat integer, delta integer)
WITH (autovacuum_enabled=off);
CREATE TABLE cj_source2 (sid2 integer, sval text)
WITH (autovacuum_enabled=off);
INSERT INTO cj_source1 VALUES (1, 10, 100);
INSERT INTO cj_source1 VALUES (1, 20, 200);
INSERT INTO cj_source1 VALUES (2, 20, 300);
INSERT INTO cj_source1 VALUES (3, 10, 400);
INSERT INTO cj_source2 VALUES (1, 'initial source2');
INSERT INTO cj_source2 VALUES (2, 'initial source2');
INSERT INTO cj_source2 VALUES (3, 'initial source2');
-- source relation is an unaliased join
MERGE INTO cj_target t
USING cj_source1 s1
INNER JOIN cj_source2 s2 ON sid1 = sid2
ON t.tid = sid1
WHEN NOT MATCHED THEN
INSERT VALUES (sid1, delta, sval);
-- try accessing columns from either side of the source join
MERGE INTO cj_target t
USING cj_source2 s2
INNER JOIN cj_source1 s1 ON sid1 = sid2 AND scat = 20
ON t.tid = sid1
WHEN NOT MATCHED THEN
INSERT VALUES (sid2, delta, sval)
WHEN MATCHED THEN
DELETE;
-- some simple expressions in INSERT targetlist
MERGE INTO cj_target t
USING cj_source2 s2
INNER JOIN cj_source1 s1 ON sid1 = sid2
ON t.tid = sid1
WHEN NOT MATCHED THEN
INSERT VALUES (sid2, delta + scat, sval)
WHEN MATCHED THEN
UPDATE SET val = val || ' updated by merge';
MERGE INTO cj_target t
USING cj_source2 s2
INNER JOIN cj_source1 s1 ON sid1 = sid2 AND scat = 20
ON t.tid = sid1
WHEN MATCHED THEN
UPDATE SET val = val || ' ' || delta::text;
SELECT * FROM cj_target;
tid | balance | val
-----+---------+----------------------------------
3 | 400 | initial source2 updated by merge
1 | 220 | initial source2 200
1 | 110 | initial source2 200
2 | 320 | initial source2 300
(4 rows)
-- try it with an outer join and PlaceHolderVar
MERGE INTO cj_target t
USING (SELECT *, 'join input'::text AS phv FROM cj_source1) fj
FULL JOIN cj_source2 fj2 ON fj.scat = fj2.sid2 * 10
ON t.tid = fj.scat
WHEN NOT MATCHED THEN
INSERT (tid, balance, val) VALUES (fj.scat, fj.delta, fj.phv);
SELECT * FROM cj_target;
tid | balance | val
-----+---------+----------------------------------
3 | 400 | initial source2 updated by merge
1 | 220 | initial source2 200
1 | 110 | initial source2 200
2 | 320 | initial source2 300
10 | 100 | join input
10 | 400 | join input
20 | 200 | join input
20 | 300 | join input
| |
(9 rows)
ALTER TABLE cj_source1 RENAME COLUMN sid1 TO sid;
ALTER TABLE cj_source2 RENAME COLUMN sid2 TO sid;
TRUNCATE cj_target;
MERGE INTO cj_target t
USING cj_source1 s1
INNER JOIN cj_source2 s2 ON s1.sid = s2.sid
ON t.tid = s1.sid
WHEN NOT MATCHED THEN
INSERT VALUES (s2.sid, delta, sval);
DROP TABLE cj_source2, cj_source1, cj_target;
-- Function scans
CREATE TABLE fs_target (a int, b int, c text)
WITH (autovacuum_enabled=off);
MERGE INTO fs_target t
USING generate_series(1,100,1) AS id
ON t.a = id
WHEN MATCHED THEN
UPDATE SET b = b + id
WHEN NOT MATCHED THEN
INSERT VALUES (id, -1);
MERGE INTO fs_target t
USING generate_series(1,100,2) AS id
ON t.a = id
WHEN MATCHED THEN
UPDATE SET b = b + id, c = 'updated '|| id.*::text
WHEN NOT MATCHED THEN
INSERT VALUES (id, -1, 'inserted ' || id.*::text);
SELECT count(*) FROM fs_target;
count
-------
100
(1 row)
DROP TABLE fs_target;
-- SERIALIZABLE test
-- handled in isolation tests
-- Inheritance-based partitioning
CREATE TABLE measurement (
city_id int not null,
logdate date not null,
peaktemp int,
unitsales int
) WITH (autovacuum_enabled=off);
CREATE TABLE measurement_y2006m02 (
CHECK ( logdate >= DATE '2006-02-01' AND logdate < DATE '2006-03-01' )
) INHERITS (measurement) WITH (autovacuum_enabled=off);
CREATE TABLE measurement_y2006m03 (
CHECK ( logdate >= DATE '2006-03-01' AND logdate < DATE '2006-04-01' )
) INHERITS (measurement) WITH (autovacuum_enabled=off);
CREATE TABLE measurement_y2007m01 (
filler text,
peaktemp int,
logdate date not null,
city_id int not null,
unitsales int
CHECK ( logdate >= DATE '2007-01-01' AND logdate < DATE '2007-02-01')
) WITH (autovacuum_enabled=off);
ALTER TABLE measurement_y2007m01 DROP COLUMN filler;
ALTER TABLE measurement_y2007m01 INHERIT measurement;
INSERT INTO measurement VALUES (0, '2005-07-21', 5, 15);
CREATE OR REPLACE FUNCTION measurement_insert_trigger()
RETURNS TRIGGER AS $$
BEGIN
IF ( NEW.logdate >= DATE '2006-02-01' AND
NEW.logdate < DATE '2006-03-01' ) THEN
INSERT INTO measurement_y2006m02 VALUES (NEW.*);
ELSIF ( NEW.logdate >= DATE '2006-03-01' AND
NEW.logdate < DATE '2006-04-01' ) THEN
INSERT INTO measurement_y2006m03 VALUES (NEW.*);
ELSIF ( NEW.logdate >= DATE '2007-01-01' AND
NEW.logdate < DATE '2007-02-01' ) THEN
INSERT INTO measurement_y2007m01 (city_id, logdate, peaktemp, unitsales)
VALUES (NEW.*);
ELSE
RAISE EXCEPTION 'Date out of range. Fix the measurement_insert_trigger() function!';
END IF;
RETURN NULL;
END;
$$ LANGUAGE plpgsql ;
CREATE TRIGGER insert_measurement_trigger
BEFORE INSERT ON measurement
FOR EACH ROW EXECUTE PROCEDURE measurement_insert_trigger();
INSERT INTO measurement VALUES (1, '2006-02-10', 35, 10);
INSERT INTO measurement VALUES (1, '2006-02-16', 45, 20);
INSERT INTO measurement VALUES (1, '2006-03-17', 25, 10);
INSERT INTO measurement VALUES (1, '2006-03-27', 15, 40);
INSERT INTO measurement VALUES (1, '2007-01-15', 10, 10);
INSERT INTO measurement VALUES (1, '2007-01-17', 10, 10);
SELECT tableoid::regclass, * FROM measurement ORDER BY city_id, logdate;
tableoid | city_id | logdate | peaktemp | unitsales
----------------------+---------+------------+----------+-----------
measurement | 0 | 07-21-2005 | 5 | 15
measurement_y2006m02 | 1 | 02-10-2006 | 35 | 10
measurement_y2006m02 | 1 | 02-16-2006 | 45 | 20
measurement_y2006m03 | 1 | 03-17-2006 | 25 | 10
measurement_y2006m03 | 1 | 03-27-2006 | 15 | 40
measurement_y2007m01 | 1 | 01-15-2007 | 10 | 10
measurement_y2007m01 | 1 | 01-17-2007 | 10 | 10
(7 rows)
CREATE TABLE new_measurement (LIKE measurement) WITH (autovacuum_enabled=off);
INSERT INTO new_measurement VALUES (0, '2005-07-21', 25, 20);
INSERT INTO new_measurement VALUES (1, '2006-03-01', 20, 10);
INSERT INTO new_measurement VALUES (1, '2006-02-16', 50, 10);
INSERT INTO new_measurement VALUES (2, '2006-02-10', 20, 20);
INSERT INTO new_measurement VALUES (1, '2006-03-27', NULL, NULL);
INSERT INTO new_measurement VALUES (1, '2007-01-17', NULL, NULL);
INSERT INTO new_measurement VALUES (1, '2007-01-15', 5, NULL);
INSERT INTO new_measurement VALUES (1, '2007-01-16', 10, 10);
BEGIN;
MERGE INTO ONLY measurement m
USING new_measurement nm ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN MATCHED AND nm.peaktemp IS NULL THEN DELETE
WHEN MATCHED THEN UPDATE
SET peaktemp = greatest(m.peaktemp, nm.peaktemp),
unitsales = m.unitsales + coalesce(nm.unitsales, 0)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id, logdate, peaktemp, unitsales);
SELECT tableoid::regclass, * FROM measurement ORDER BY city_id, logdate, peaktemp;
tableoid | city_id | logdate | peaktemp | unitsales
----------------------+---------+------------+----------+-----------
measurement | 0 | 07-21-2005 | 25 | 35
measurement_y2006m02 | 1 | 02-10-2006 | 35 | 10
measurement_y2006m02 | 1 | 02-16-2006 | 45 | 20
measurement_y2006m02 | 1 | 02-16-2006 | 50 | 10
measurement_y2006m03 | 1 | 03-01-2006 | 20 | 10
measurement_y2006m03 | 1 | 03-17-2006 | 25 | 10
measurement_y2006m03 | 1 | 03-27-2006 | 15 | 40
measurement_y2006m03 | 1 | 03-27-2006 | |
measurement_y2007m01 | 1 | 01-15-2007 | 5 |
measurement_y2007m01 | 1 | 01-15-2007 | 10 | 10
measurement_y2007m01 | 1 | 01-16-2007 | 10 | 10
measurement_y2007m01 | 1 | 01-17-2007 | 10 | 10
measurement_y2007m01 | 1 | 01-17-2007 | |
measurement_y2006m02 | 2 | 02-10-2006 | 20 | 20
(14 rows)
ROLLBACK;
MERGE into measurement m
USING new_measurement nm ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN MATCHED AND nm.peaktemp IS NULL THEN DELETE
WHEN MATCHED THEN UPDATE
SET peaktemp = greatest(m.peaktemp, nm.peaktemp),
unitsales = m.unitsales + coalesce(nm.unitsales, 0)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id, logdate, peaktemp, unitsales);
SELECT tableoid::regclass, * FROM measurement ORDER BY city_id, logdate;
tableoid | city_id | logdate | peaktemp | unitsales
----------------------+---------+------------+----------+-----------
measurement | 0 | 07-21-2005 | 25 | 35
measurement_y2006m02 | 1 | 02-10-2006 | 35 | 10
measurement_y2006m02 | 1 | 02-16-2006 | 50 | 30
measurement_y2006m03 | 1 | 03-01-2006 | 20 | 10
measurement_y2006m03 | 1 | 03-17-2006 | 25 | 10
measurement_y2007m01 | 1 | 01-15-2007 | 10 | 10
measurement_y2007m01 | 1 | 01-16-2007 | 10 | 10
measurement_y2006m02 | 2 | 02-10-2006 | 20 | 20
(8 rows)
BEGIN;
MERGE INTO new_measurement nm
USING ONLY measurement m ON
(nm.city_id = m.city_id and nm.logdate=m.logdate)
WHEN MATCHED THEN DELETE;
SELECT * FROM new_measurement ORDER BY city_id, logdate;
city_id | logdate | peaktemp | unitsales
---------+------------+----------+-----------
1 | 02-16-2006 | 50 | 10
1 | 03-01-2006 | 20 | 10
1 | 03-27-2006 | |
1 | 01-15-2007 | 5 |
1 | 01-16-2007 | 10 | 10
1 | 01-17-2007 | |
2 | 02-10-2006 | 20 | 20
(7 rows)
ROLLBACK;
MERGE INTO new_measurement nm
USING measurement m ON
(nm.city_id = m.city_id and nm.logdate=m.logdate)
WHEN MATCHED THEN DELETE;
SELECT * FROM new_measurement ORDER BY city_id, logdate;
city_id | logdate | peaktemp | unitsales
---------+------------+----------+-----------
1 | 03-27-2006 | |
1 | 01-17-2007 | |
(2 rows)
-- MERGE into inheritance root table
DROP TRIGGER insert_measurement_trigger ON measurement;
ALTER TABLE measurement ADD CONSTRAINT mcheck CHECK (city_id = 0) NO INHERIT;
EXPLAIN (COSTS OFF)
MERGE INTO measurement m
USING (VALUES (1, '01-17-2007'::date)) nm(city_id, logdate) ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id - 1, logdate, 25, 100);
QUERY PLAN
--------------------------------------------------------------------------
Merge on measurement m
Merge on measurement_y2007m01 m_1
-> Nested Loop Left Join
-> Result
-> Seq Scan on measurement_y2007m01 m_1
Filter: ((city_id = 1) AND (logdate = '01-17-2007'::date))
(6 rows)
BEGIN;
MERGE INTO measurement m
USING (VALUES (1, '01-17-2007'::date)) nm(city_id, logdate) ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id - 1, logdate, 25, 100);
SELECT * FROM ONLY measurement ORDER BY city_id, logdate;
city_id | logdate | peaktemp | unitsales
---------+------------+----------+-----------
0 | 07-21-2005 | 25 | 35
0 | 01-17-2007 | 25 | 100
(2 rows)
ROLLBACK;
ALTER TABLE measurement ENABLE ROW LEVEL SECURITY;
ALTER TABLE measurement FORCE ROW LEVEL SECURITY;
CREATE POLICY measurement_p ON measurement USING (peaktemp IS NOT NULL);
MERGE INTO measurement m
USING (VALUES (1, '01-17-2007'::date)) nm(city_id, logdate) ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id - 1, logdate, NULL, 100); -- should fail
ERROR: new row violates row-level security policy for table "measurement"
MERGE INTO measurement m
USING (VALUES (1, '01-17-2007'::date)) nm(city_id, logdate) ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id - 1, logdate, 25, 100); -- ok
SELECT * FROM ONLY measurement ORDER BY city_id, logdate;
city_id | logdate | peaktemp | unitsales
---------+------------+----------+-----------
0 | 07-21-2005 | 25 | 35
0 | 01-17-2007 | 25 | 100
(2 rows)
MERGE INTO measurement m
USING (VALUES (1, '01-18-2007'::date)) nm(city_id, logdate) ON
(m.city_id = nm.city_id and m.logdate=nm.logdate)
WHEN NOT MATCHED THEN INSERT
(city_id, logdate, peaktemp, unitsales)
VALUES (city_id - 1, logdate, 25, 200)
RETURNING merge_action(), m.*;
merge_action | city_id | logdate | peaktemp | unitsales
--------------+---------+------------+----------+-----------
INSERT | 0 | 01-18-2007 | 25 | 200
(1 row)
DROP TABLE measurement, new_measurement CASCADE;
NOTICE: drop cascades to 3 other objects
DETAIL: drop cascades to table measurement_y2006m02
drop cascades to table measurement_y2006m03
drop cascades to table measurement_y2007m01
DROP FUNCTION measurement_insert_trigger();
--
-- test non-strict join clause
--
CREATE TABLE src (a int, b text);
INSERT INTO src VALUES (1, 'src row');
CREATE TABLE tgt (a int, b text);
INSERT INTO tgt VALUES (NULL, 'tgt row');
MERGE INTO tgt USING src ON tgt.a IS NOT DISTINCT FROM src.a
WHEN MATCHED THEN UPDATE SET a = src.a, b = src.b
WHEN NOT MATCHED BY SOURCE THEN DELETE
RETURNING merge_action(), src.*, tgt.*;
merge_action | a | b | a | b
--------------+---+---+---+---------
DELETE | | | | tgt row
(1 row)
SELECT * FROM tgt;
a | b
---+---
(0 rows)
DROP TABLE src, tgt;
--
-- test for bug #18634 (wrong varnullingrels error)
--
CREATE TABLE bug18634t (a int, b int, c text);
INSERT INTO bug18634t VALUES(1, 10, 'tgt1'), (2, 20, 'tgt2');
CREATE VIEW bug18634v AS
SELECT * FROM bug18634t WHERE EXISTS (SELECT 1 FROM bug18634t);
CREATE TABLE bug18634s (a int, b int, c text);
INSERT INTO bug18634s VALUES (1, 2, 'src1');
MERGE INTO bug18634v t USING bug18634s s ON s.a = t.a
WHEN MATCHED THEN UPDATE SET b = s.b
WHEN NOT MATCHED BY SOURCE THEN DELETE
RETURNING merge_action(), s.c, t.*;
merge_action | c | a | b | c
--------------+------+---+----+------
UPDATE | src1 | 1 | 2 | tgt1
DELETE | | 2 | 20 | tgt2
(2 rows)
SELECT * FROM bug18634t;
a | b | c
---+---+------
1 | 2 | tgt1
(1 row)
DROP TABLE bug18634t CASCADE;
NOTICE: drop cascades to view bug18634v
DROP TABLE bug18634s;
-- prepare
RESET SESSION AUTHORIZATION;
-- try a system catalog
MERGE INTO pg_class c
USING (SELECT 'pg_depend'::regclass AS oid) AS j
ON j.oid = c.oid
WHEN MATCHED THEN
UPDATE SET reltuples = reltuples + 1
RETURNING j.oid;
oid
-----------
pg_depend
(1 row)
CREATE VIEW classv AS SELECT * FROM pg_class;
MERGE INTO classv c
USING pg_namespace n
ON n.oid = c.relnamespace
WHEN MATCHED AND c.oid = 'pg_depend'::regclass THEN
UPDATE SET reltuples = reltuples - 1
RETURNING c.oid;
oid
------
2608
(1 row)
DROP TABLE target, target2;
DROP TABLE source, source2;
DROP FUNCTION merge_trigfunc();
DROP USER regress_merge_privs;
DROP USER regress_merge_no_privs;
DROP USER regress_merge_none;
[Dauer der Verarbeitung: 0.39 Sekunden, vorverarbeitet 2026-08-08]
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