3 files changed, 76 insertions, 0 deletions

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 3bfabb6d10b..03b24ab90f1 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1070,6 +1070,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
 				relfilenumber2;
 	RelFileNumber swaptemp;
 	char		swptmpchr;
+	Oid			relam1,
+				relam2;
 
 	/* We need writable copies of both pg_class tuples. */
 	relRelation = table_open(RelationRelationId, RowExclusiveLock);
@@ -1086,6 +1088,8 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
 
 	relfilenumber1 = relform1->relfilenode;
 	relfilenumber2 = relform2->relfilenode;
+	relam1 = relform1->relam;
+	relam2 = relform2->relam;
 
 	if (RelFileNumberIsValid(relfilenumber1) &&
 		RelFileNumberIsValid(relfilenumber2))
@@ -1258,6 +1262,31 @@ swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
 	}
 
 	/*
+	 * Now that pg_class has been updated with its relevant information for
+	 * the swap, update the dependency of the relations to point to their new
+	 * table AM, if it has changed.
+	 */
+	if (relam1 != relam2)
+	{
+		if (changeDependencyFor(RelationRelationId,
+								r1,
+								AccessMethodRelationId,
+								relam1,
+								relam2) != 1)
+			elog(ERROR, "failed to change access method dependency for relation \"%s.%s\"",
+				 get_namespace_name(get_rel_namespace(r1)),
+				 get_rel_name(r1));
+		if (changeDependencyFor(RelationRelationId,
+								r2,
+								AccessMethodRelationId,
+								relam2,
+								relam1) != 1)
+			elog(ERROR, "failed to change access method dependency for relation \"%s.%s\"",
+				 get_namespace_name(get_rel_namespace(r2)),
+				 get_rel_name(r2));
+	}
+
+	/*
 	 * Post alter hook for modified relations. The change to r2 is always
 	 * internal, but r1 depends on the invocation context.
 	 */
diff --git a/src/test/regress/expected/create_am.out b/src/test/regress/expected/create_am.out
index e9a9283d7ab..b50293d514f 100644
--- a/src/test/regress/expected/create_am.out
+++ b/src/test/regress/expected/create_am.out
@@ -240,6 +240,35 @@ SELECT amname FROM pg_class c, pg_am am
  heap
 (1 row)
 
+-- Switching to heap2 adds new dependency entry to the AM.
+ALTER TABLE heaptable SET ACCESS METHOD heap2;
+SELECT pg_describe_object(classid, objid, objsubid) as obj,
+       pg_describe_object(refclassid, refobjid, refobjsubid) as objref,
+       deptype
+  FROM pg_depend
+  WHERE classid = 'pg_class'::regclass AND
+        objid = 'heaptable'::regclass
+  ORDER BY 1, 2;
+       obj       |       objref        | deptype 
+-----------------+---------------------+---------
+ table heaptable | access method heap2 | n
+ table heaptable | schema public       | n
+(2 rows)
+
+-- Switching to heap should not have a dependency entry to the AM.
+ALTER TABLE heaptable SET ACCESS METHOD heap;
+SELECT pg_describe_object(classid, objid, objsubid) as obj,
+       pg_describe_object(refclassid, refobjid, refobjsubid) as objref,
+       deptype
+  FROM pg_depend
+  WHERE classid = 'pg_class'::regclass AND
+        objid = 'heaptable'::regclass
+  ORDER BY 1, 2;
+       obj       |    objref     | deptype 
+-----------------+---------------+---------
+ table heaptable | schema public | n
+(1 row)
+
 ALTER TABLE heaptable SET ACCESS METHOD heap2;
 SELECT amname FROM pg_class c, pg_am am
   WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass;
diff --git a/src/test/regress/sql/create_am.sql b/src/test/regress/sql/create_am.sql
index 256884c9592..2785ffd8bbb 100644
--- a/src/test/regress/sql/create_am.sql
+++ b/src/test/regress/sql/create_am.sql
@@ -166,6 +166,24 @@ CREATE TABLE heaptable USING heap AS
   SELECT a, repeat(a::text, 100) FROM generate_series(1,9) AS a;
 SELECT amname FROM pg_class c, pg_am am
   WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass;
+-- Switching to heap2 adds new dependency entry to the AM.
+ALTER TABLE heaptable SET ACCESS METHOD heap2;
+SELECT pg_describe_object(classid, objid, objsubid) as obj,
+       pg_describe_object(refclassid, refobjid, refobjsubid) as objref,
+       deptype
+  FROM pg_depend
+  WHERE classid = 'pg_class'::regclass AND
+        objid = 'heaptable'::regclass
+  ORDER BY 1, 2;
+-- Switching to heap should not have a dependency entry to the AM.
+ALTER TABLE heaptable SET ACCESS METHOD heap;
+SELECT pg_describe_object(classid, objid, objsubid) as obj,
+       pg_describe_object(refclassid, refobjid, refobjsubid) as objref,
+       deptype
+  FROM pg_depend
+  WHERE classid = 'pg_class'::regclass AND
+        objid = 'heaptable'::regclass
+  ORDER BY 1, 2;
 ALTER TABLE heaptable SET ACCESS METHOD heap2;
 SELECT amname FROM pg_class c, pg_am am
   WHERE c.relam = am.oid AND c.oid = 'heaptable'::regclass;