fix drop_single_update_trigger_internal() to avoid warnings; fix replace_hash_partition()

Author: zilder

expected/pathman_basic.out

@@ -1303,6 +1303,7 @@ SELECT * FROM test.hash_rel WHERE id = 123;
 /* Test replacing hash partition */
 CREATE TABLE test.hash_rel_extern (LIKE test.hash_rel INCLUDING ALL);
 SELECT pathman.replace_hash_partition('test.hash_rel_0', 'test.hash_rel_extern');
+NOTICE:  trigger "hash_rel_upd_trig" for relation "test.hash_rel_0" does not exist, skipping
  replace_hash_partition 
 ------------------------
  test.hash_rel_extern
@@ -1338,6 +1339,7 @@ CREATE TABLE test.hash_rel_wrong(
 	id		INTEGER NOT NULL,
 	value	INTEGER);
 SELECT pathman.replace_hash_partition('test.hash_rel_1', 'test.hash_rel_wrong');
+NOTICE:  trigger "hash_rel_upd_trig" for relation "test.hash_rel_1" does not exist, skipping
 ERROR:  column "value" in child table must be marked NOT NULL
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;
             QUERY PLAN             

hash.sql

@@ -143,13 +143,19 @@ BEGIN
 	EXECUTE format('ALTER TABLE %s DROP CONSTRAINT %s',
 				   old_partition,
 				   old_constr_name);
+	EXECUTE format('DROP TRIGGER IF EXISTS %s ON %s',
+				   @extschema@.build_update_trigger_name(parent_relid),
+				   old_partition);
 
 	/* Attach the new one */
 	EXECUTE format('ALTER TABLE %s INHERIT %s', new_partition, parent_relid);
 	EXECUTE format('ALTER TABLE %s ADD CONSTRAINT %s %s',
 				   new_partition,
 				   @extschema@.build_check_constraint_name(new_partition::REGCLASS),
 				   old_constr_def);
+	IF @extschema@.has_update_trigger(parent_relid) THEN
+		PERFORM @extschema@.create_single_update_trigger(parent_relid, new_partition);
+	END IF;
 
 	/* Fetch init_callback from 'params' table */
 	WITH stub_callback(stub) as (values (0))

range.sql

@@ -970,7 +970,7 @@ BEGIN
 	INTO v_init_callback;
 
 	/* If update trigger is enabled then create one for this partition */
-	if @extschema@.has_update_trigger(parent_relid) THEN
+	IF @extschema@.has_update_trigger(parent_relid) THEN
 		PERFORM @extschema@.create_single_update_trigger(parent_relid, partition_relid);
 	END IF;
 

src/partition_creation.c

@@ -1827,14 +1827,33 @@ drop_single_update_trigger_internal(Oid relid,
 	DropStmt	   *n = makeNode(DropStmt);
 	const char	   *relname = get_qualified_rel_name(relid);
 	List		   *namelist = stringToQualifiedNameList(relname);
+	Relation		relation = NULL;
+	ObjectAddress	address;
 
 	namelist = lappend(namelist, makeString((char *) trigname));
+
+	/*
+	 * To avoid warning message about missing trigger we check it beforehand.
+	 * and quit if it doesn't
+	 */
+	address = get_object_address(OBJECT_TRIGGER,
+								 namelist, NIL,
+								 &relation,
+								 AccessExclusiveLock,
+								 true);
+	if (!OidIsValid(address.objectId))
+		return;
+
+	/* Actually remove trigger */
 	n->removeType	= OBJECT_TRIGGER;
-	n->missing_ok	= true;
 	n->objects		= list_make1(namelist);
 	n->arguments	= NIL;
 	n->behavior		= DROP_RESTRICT;  /* default behavior */
-	n->concurrent	= false;
-
+	n->missing_ok	= true;
+	n->concurrent	= false;		
 	RemoveObjects(n);
+
+	/* Release any relcache reference count, but keep lock until commit. */
+	if (relation)
+		heap_close(relation, NoLock);
 }

src/pl_funcs.c

@@ -1527,8 +1527,6 @@ create_update_triggers_internal(Oid relid)
 
 	/* Check that table is partitioned */
 	prel = get_pathman_relation_info(relid);
-	/* TODO: check this only for topmost relid? */
-	// shout_if_prel_is_invalid(relid, prel, PT_ANY);
 	if (!prel)
 		return;