[PGPRO-8041] Fixed restrictions for pg_pathman.enable

Tags: pg_pathman

Author: kovdb75

expected/pathman_runtime_nodes.out

@@ -465,8 +465,12 @@ DROP SCHEMA test;
 -- Variable pg_pathman.enable must be called before any query.
 --
 CREATE TABLE part_test (val int NOT NULL);
-SELECT create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
-ERROR:  function create_hash_partitions(unknown, unknown, integer, partition_names => text[]) does not exist at character 8
+SELECT pathman.create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
+ create_hash_partitions 
+------------------------
+                      2
+(1 row)
+
 CREATE OR REPLACE FUNCTION part_test_trigger() RETURNS TRIGGER AS $$
 BEGIN
 	RAISE NOTICE '%', format('%s %s %s (%s)', TG_WHEN, TG_OP, TG_LEVEL, TG_TABLE_NAME);
@@ -478,22 +482,24 @@ END;
 $$ LANGUAGE PLPGSQL;
 SET pg_pathman.enable_partitionrouter = t;
 CREATE TRIGGER ad AFTER DELETE ON part_test_1 FOR EACH ROW EXECUTE PROCEDURE part_test_trigger ();
-ERROR:  relation "part_test_1" does not exist
 INSERT INTO part_test VALUES (1);
 UPDATE part_test SET val = val + 1 RETURNING *, tableoid::regclass;
- val | tableoid  
------+-----------
-   2 | part_test
+ val |  tableoid   
+-----+-------------
+   2 | part_test_1
 (1 row)
 
 UPDATE part_test SET val = val + 1 RETURNING *, tableoid::regclass;
- val | tableoid  
------+-----------
-   3 | part_test
+NOTICE:  AFTER DELETE ROW (part_test_1)
+WARNING:  "SET pg_pathman.enable" must be called before any query. Command ignored.
+ val |  tableoid  
+-----+------------
+   3 | pg_pathman
 (1 row)
 
 RESET pg_pathman.enable_partitionrouter;
 DROP TABLE part_test CASCADE;
+NOTICE:  drop cascades to 2 other objects
 DROP FUNCTION part_test_trigger();
 DROP EXTENSION pg_pathman CASCADE;
 DROP SCHEMA pathman;

expected/pathman_runtime_nodes_1.out

@@ -465,8 +465,12 @@ DROP SCHEMA test;
 -- Variable pg_pathman.enable must be called before any query.
 --
 CREATE TABLE part_test (val int NOT NULL);
-SELECT create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
-ERROR:  function create_hash_partitions(unknown, unknown, integer, partition_names => text[]) does not exist at character 8
+SELECT pathman.create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
+ create_hash_partitions 
+------------------------
+                      2
+(1 row)
+
 CREATE OR REPLACE FUNCTION part_test_trigger() RETURNS TRIGGER AS $$
 BEGIN
 	RAISE NOTICE '%', format('%s %s %s (%s)', TG_WHEN, TG_OP, TG_LEVEL, TG_TABLE_NAME);
@@ -478,22 +482,24 @@ END;
 $$ LANGUAGE PLPGSQL;
 SET pg_pathman.enable_partitionrouter = t;
 CREATE TRIGGER ad AFTER DELETE ON part_test_1 FOR EACH ROW EXECUTE PROCEDURE part_test_trigger ();
-ERROR:  relation "part_test_1" does not exist
 INSERT INTO part_test VALUES (1);
 UPDATE part_test SET val = val + 1 RETURNING *, tableoid::regclass;
- val | tableoid  
------+-----------
-   2 | part_test
+ val |  tableoid   
+-----+-------------
+   2 | part_test_1
 (1 row)
 
 UPDATE part_test SET val = val + 1 RETURNING *, tableoid::regclass;
- val | tableoid  
------+-----------
-   3 | part_test
+NOTICE:  AFTER DELETE ROW (part_test_1)
+WARNING:  "SET pg_pathman.enable" must be called before any query. Command ignored.
+ val |  tableoid  
+-----+------------
+   3 | pg_pathman
 (1 row)
 
 RESET pg_pathman.enable_partitionrouter;
 DROP TABLE part_test CASCADE;
+NOTICE:  drop cascades to 2 other objects
 DROP FUNCTION part_test_trigger();
 DROP EXTENSION pg_pathman CASCADE;
 DROP SCHEMA pathman;

sql/pathman_runtime_nodes.sql

@@ -348,7 +348,7 @@ DROP SCHEMA test;
 -- Variable pg_pathman.enable must be called before any query.
 --
 CREATE TABLE part_test (val int NOT NULL);
-SELECT create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
+SELECT pathman.create_hash_partitions('part_test', 'val', 2, partition_names := array['part_test_1','pg_pathman']);
 CREATE OR REPLACE FUNCTION part_test_trigger() RETURNS TRIGGER AS $$
 BEGIN
 	RAISE NOTICE '%', format('%s %s %s (%s)', TG_WHEN, TG_OP, TG_LEVEL, TG_TABLE_NAME);

src/hooks.c

@@ -621,16 +621,29 @@ pathman_rel_pathlist_hook(PlannerInfo *root,
 bool
 pathman_enable_check_hook(bool *newval, void **extra, GucSource source)
 {
+	/* The top level statement requires immediate commit: accept GUC change */
+	if (MyXactFlags & XACT_FLAGS_NEEDIMMEDIATECOMMIT)
+		return true;
+
+	/* Ignore the case of re-setting the same value */
+	if (*newval == pathman_init_state.pg_pathman_enable)
+		return true;
+
+	/* Command must be at top level of a fresh transaction. */
 	if (FirstSnapshotSet ||
 		GetTopTransactionIdIfAny() != InvalidTransactionId ||
 #ifdef PGPRO_EE
 		getNestLevelATX() > 0 ||
 #endif
 		IsSubTransaction())
 	{
-		GUC_check_errcode(ERRCODE_ACTIVE_SQL_TRANSACTION);
-		GUC_check_errmsg("\"pg_pathman.enable\" must be called before any query");
-		return false;
+		/* Keep the old value. */
+		*newval = pathman_init_state.pg_pathman_enable;
+
+		ereport(WARNING,
+				(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
+				 errmsg("\"SET pg_pathman.enable\" must be called before any query. "
+						"Command ignored.")));
 	}
 
 	return true;