ALTER INDEX .. RENAME allows to rename tables/views as well

From c516a0c36e246a0c746be73cc75cda441a5f748d Mon Sep 17 00:00:00 2001
From: Nathan Bossart <bossartn@amazon.com>
Date: Wed, 6 Oct 2021 22:11:42 +0000
Subject: [PATCH v1 1/1] Add object type validation in RenameRelation().

RenameRelation() is used for renaming several object types, but
there is presently no verification that the object type matches the
statement type.  For example, ALTER TABLE ... RENAME can be used to
rename indexes.  Since the renaming logic can differ between object
types, it is important to ensure that the object type and statement
type match.
---
 src/backend/commands/cluster.c            |  4 ++--
 src/backend/commands/tablecmds.c          | 16 ++++++++++++----
 src/backend/commands/typecmds.c           |  2 +-
 src/include/commands/tablecmds.h          |  2 +-
 src/test/regress/expected/alter_table.out |  6 +++++-
 src/test/regress/expected/sequence.out    |  4 ++--
 src/test/regress/sql/alter_table.sql      |  5 ++++-
 src/test/regress/sql/sequence.sql         |  4 ++--
 8 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 9d22f648a8..7ee00691ab 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1518,14 +1518,14 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
 			snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u",
 					 OIDOldHeap);
 			RenameRelationInternal(newrel->rd_rel->reltoastrelid,
-								   NewToastName, true, false);
+								   NewToastName, true, OBJECT_TABLE);
 
 			/* ... and its valid index too. */
 			snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u_index",
 					 OIDOldHeap);
 
 			RenameRelationInternal(toastidx,
-								   NewToastName, true, true);
+								   NewToastName, true, OBJECT_INDEX);
 
 			/*
 			 * Reset the relrewrite for the toast. The command-counter
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ff97b618e6..f8f5b6f85d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -3660,7 +3660,7 @@ rename_constraint_internal(Oid myrelid,
 			|| con->contype == CONSTRAINT_UNIQUE
 			|| con->contype == CONSTRAINT_EXCLUSION))
 		/* rename the index; this renames the constraint as well */
-		RenameRelationInternal(con->conindid, newconname, false, true);
+		RenameRelationInternal(con->conindid, newconname, false, OBJECT_INDEX);
 	else
 		RenameConstraintById(constraintOid, newconname);
 
@@ -3762,7 +3762,7 @@ RenameRelation(RenameStmt *stmt)
 	}
 
 	/* Do the work */
-	RenameRelationInternal(relid, stmt->newname, false, is_index);
+	RenameRelationInternal(relid, stmt->newname, false, stmt->renameType);
 
 	ObjectAddressSet(address, RelationRelationId, relid);
 
@@ -3773,13 +3773,14 @@ RenameRelation(RenameStmt *stmt)
  *		RenameRelationInternal - change the name of a relation
  */
 void
-RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bool is_index)
+RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, ObjectType renameType)
 {
 	Relation	targetrelation;
 	Relation	relrelation;	/* for RELATION relation */
 	HeapTuple	reltup;
 	Form_pg_class relform;
 	Oid			namespaceId;
+	bool		is_index = renameType == OBJECT_INDEX;
 
 	/*
 	 * Grab a lock on the target relation, which we will NOT release until end
@@ -3804,6 +3805,13 @@ RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bo
 		elog(ERROR, "cache lookup failed for relation %u", myrelid);
 	relform = (Form_pg_class) GETSTRUCT(reltup);
 
+	if (get_relkind_objtype(relform->relkind) != renameType)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot rename \"%s\"",
+						NameStr(relform->relname)),
+				 errdetail_relkind_not_supported(relform->relkind)));
+
 	if (get_relname_relid(newrelname, namespaceId) != InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_DUPLICATE_TABLE),
@@ -8620,7 +8628,7 @@ ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
 		ereport(NOTICE,
 				(errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"",
 						indexName, constraintName)));
-		RenameRelationInternal(index_oid, constraintName, false, true);
+		RenameRelationInternal(index_oid, constraintName, false, OBJECT_INDEX);
 	}
 
 	/* Extra checks needed if making primary key */
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index b290629a45..4a971a103d 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -3659,7 +3659,7 @@ RenameType(RenameStmt *stmt)
 	 * RenameRelationInternal will call RenameTypeInternal automatically.
 	 */
 	if (typTup->typtype == TYPTYPE_COMPOSITE)
-		RenameRelationInternal(typTup->typrelid, newTypeName, false, false);
+		RenameRelationInternal(typTup->typrelid, newTypeName, false, stmt->renameType);
 	else
 		RenameTypeInternal(typeOid, newTypeName,
 						   typTup->typnamespace);
diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h
index 336549cc5f..48d3a782af 100644
--- a/src/include/commands/tablecmds.h
+++ b/src/include/commands/tablecmds.h
@@ -76,7 +76,7 @@ extern ObjectAddress RenameRelation(RenameStmt *stmt);
 
 extern void RenameRelationInternal(Oid myrelid,
 								   const char *newrelname, bool is_internal,
-								   bool is_index);
+								   ObjectType renameType);
 
 extern void ResetRelRewrite(Oid myrelid);
 
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 4bee0c1173..fb1909de3c 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -232,9 +232,13 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 ERROR:  must be owner of index onek_unique1
 RESET ROLE;
+-- ALTER TABLE ... RENAME on index fails
+ALTER TABLE onek_unique1 RENAME TO fail;
+ERROR:  cannot rename "onek_unique1"
+DETAIL:  This operation is not supported for indexes.
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
-ALTER TABLE attmp_view RENAME TO attmp_view_new;
+ALTER VIEW attmp_view RENAME TO attmp_view_new;
 SET ROLE regress_alter_table_user1;
 ALTER VIEW attmp_view_new RENAME TO fail;  -- permission denied
 ERROR:  must be owner of view attmp_view_new
diff --git a/src/test/regress/expected/sequence.out b/src/test/regress/expected/sequence.out
index 71c2b0f1df..d0a5dd8d76 100644
--- a/src/test/regress/expected/sequence.out
+++ b/src/test/regress/expected/sequence.out
@@ -241,7 +241,7 @@ ERROR:  currval of sequence "sequence_test" is not yet defined in this session
 DROP SEQUENCE sequence_test;
 -- renaming sequences
 CREATE SEQUENCE foo_seq;
-ALTER TABLE foo_seq RENAME TO foo_seq_new;
+ALTER SEQUENCE foo_seq RENAME TO foo_seq_new;
 SELECT * FROM foo_seq_new;
  last_value | log_cnt | is_called 
 ------------+---------+-----------
@@ -270,7 +270,7 @@ SELECT last_value, log_cnt IN (31, 32) AS log_cnt_ok, is_called FROM foo_seq_new
 
 DROP SEQUENCE foo_seq_new;
 -- renaming serial sequences
-ALTER TABLE serialtest1_f2_seq RENAME TO serialtest1_f2_foo;
+ALTER SEQUENCE serialtest1_f2_seq RENAME TO serialtest1_f2_foo;
 INSERT INTO serialTest1 VALUES ('more');
 SELECT * FROM serialTest1;
   f1   | f2  
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index dc0200adcb..8106c8617b 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -227,9 +227,12 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 RESET ROLE;
 
+-- ALTER TABLE ... RENAME on index fails
+ALTER TABLE onek_unique1 RENAME TO fail;
+
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
-ALTER TABLE attmp_view RENAME TO attmp_view_new;
+ALTER VIEW attmp_view RENAME TO attmp_view_new;
 
 SET ROLE regress_alter_table_user1;
 ALTER VIEW attmp_view_new RENAME TO fail;  -- permission denied
diff --git a/src/test/regress/sql/sequence.sql b/src/test/regress/sql/sequence.sql
index 7928ee23ee..3d3a90b544 100644
--- a/src/test/regress/sql/sequence.sql
+++ b/src/test/regress/sql/sequence.sql
@@ -132,7 +132,7 @@ DROP SEQUENCE sequence_test;
 
 -- renaming sequences
 CREATE SEQUENCE foo_seq;
-ALTER TABLE foo_seq RENAME TO foo_seq_new;
+ALTER SEQUENCE foo_seq RENAME TO foo_seq_new;
 SELECT * FROM foo_seq_new;
 SELECT nextval('foo_seq_new');
 SELECT nextval('foo_seq_new');
@@ -142,7 +142,7 @@ SELECT last_value, log_cnt IN (31, 32) AS log_cnt_ok, is_called FROM foo_seq_new
 DROP SEQUENCE foo_seq_new;
 
 -- renaming serial sequences
-ALTER TABLE serialtest1_f2_seq RENAME TO serialtest1_f2_foo;
+ALTER SEQUENCE serialtest1_f2_seq RENAME TO serialtest1_f2_foo;
 INSERT INTO serialTest1 VALUES ('more');
 SELECT * FROM serialTest1;
 
-- 
2.16.6

From c7db185e7c75f197a55d7e73b898b3b0858796cc Mon Sep 17 00:00:00 2001
From: Nathan Bossart <bossartn@amazon.com>
Date: Thu, 7 Oct 2021 00:36:06 +0000
Subject: [PATCH v2 1/1] Ensure correct lock level is used for rename
 statements.

We allow mismatching statement and object types for some rename
statements, but that can cause the wrong lock level to be used.
When that happens, retry the relation lookup with the correct lock
level.
---
 src/backend/commands/tablecmds.c          | 45 ++++++++++++++++++++++---------
 src/test/regress/expected/alter_table.out |  6 +++++
 src/test/regress/sql/alter_table.sql      |  7 +++++
 3 files changed, 45 insertions(+), 13 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ff97b618e6..d42ed13344 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -3735,7 +3735,7 @@ RenameConstraint(RenameStmt *stmt)
 ObjectAddress
 RenameRelation(RenameStmt *stmt)
 {
-	bool		is_index = stmt->renameType == OBJECT_INDEX;
+	bool		is_index_stmt = stmt->renameType == OBJECT_INDEX;
 	Oid			relid;
 	ObjectAddress address;
 
@@ -3747,22 +3747,41 @@ RenameRelation(RenameStmt *stmt)
 	 * Lock level used here should match RenameRelationInternal, to avoid lock
 	 * escalation.
 	 */
-	relid = RangeVarGetRelidExtended(stmt->relation,
-									 is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock,
-									 stmt->missing_ok ? RVR_MISSING_OK : 0,
-									 RangeVarCallbackForAlterRelation,
-									 (void *) stmt);
-
-	if (!OidIsValid(relid))
+	for (;;)
 	{
-		ereport(NOTICE,
-				(errmsg("relation \"%s\" does not exist, skipping",
-						stmt->relation->relname)));
-		return InvalidObjectAddress;
+		LOCKMODE	lockmode;
+		bool		obj_is_index;
+
+		lockmode = is_index_stmt ? ShareUpdateExclusiveLock : AccessExclusiveLock;
+
+		relid = RangeVarGetRelidExtended(stmt->relation, lockmode,
+										 stmt->missing_ok ? RVR_MISSING_OK : 0,
+										 RangeVarCallbackForAlterRelation,
+										 (void *) stmt);
+
+		if (!OidIsValid(relid))
+		{
+			ereport(NOTICE,
+					(errmsg("relation \"%s\" does not exist, skipping",
+							stmt->relation->relname)));
+			return InvalidObjectAddress;
+		}
+
+		/*
+		 * We allow mismatched statement and object types (e.g., ALTER INDEX to
+		 * rename a table), but we might've used the wrong lock level.  If that
+		 * happens, retry with the correct lock level.
+		 */
+		obj_is_index = (get_rel_relkind(relid) == RELKIND_INDEX);
+		if (is_index_stmt == obj_is_index)
+			break;
+
+		UnlockRelationOid(relid, lockmode);
+		is_index_stmt = obj_is_index;
 	}
 
 	/* Do the work */
-	RenameRelationInternal(relid, stmt->newname, false, is_index);
+	RenameRelationInternal(relid, stmt->newname, false, is_index_stmt);
 
 	ObjectAddressSet(address, RelationRelationId, relid);
 
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 4bee0c1173..b39430f201 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -232,6 +232,12 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 ERROR:  must be owner of index onek_unique1
 RESET ROLE;
+-- rename statements with mismatching statement and object types
+CREATE TABLE alter_idx_rename_test (a INT);
+CREATE INDEX alter_idx_rename_test_idx ON alter_idx_rename_test (a);
+ALTER INDEX alter_idx_rename_test RENAME TO alter_idx_rename_test_2;
+ALTER TABLE alter_idx_rename_test_idx RENAME TO alter_idx_rename_test_idx_2;
+DROP TABLE alter_idx_rename_test_2;
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
 ALTER TABLE attmp_view RENAME TO attmp_view_new;
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index dc0200adcb..a56926f915 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -227,6 +227,13 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 RESET ROLE;
 
+-- rename statements with mismatching statement and object types
+CREATE TABLE alter_idx_rename_test (a INT);
+CREATE INDEX alter_idx_rename_test_idx ON alter_idx_rename_test (a);
+ALTER INDEX alter_idx_rename_test RENAME TO alter_idx_rename_test_2;
+ALTER TABLE alter_idx_rename_test_idx RENAME TO alter_idx_rename_test_idx_2;
+DROP TABLE alter_idx_rename_test_2;
+
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
 ALTER TABLE attmp_view RENAME TO attmp_view_new;
-- 
2.16.6

From 04334bc719efe69f63c8a590b9c682a22c6fb413 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Tue, 19 Oct 2021 17:02:17 -0300
Subject: [PATCH v3] Ensure correct lock level is used in ALTER ... RENAME

Commit 1b5d797cd4f7 intended to relax the lock level used to rename
indexes, but inadvertently allowed *any* relation to be renamed with a
lowered lock level, as long as the command is spelled ALTER INDEX.
That's undesirable for other relation types, so retry the operation with
the higher lock if the relation turns out not to be an index.

After this fix, ALTER INDEX <sometable> RENAME will require access
exclusive lock.

Author: Nathan Bossart <bossartn@amazon.com>
Reported-by: Onder Kalaci <onderk@microsoft.com>
Discussion: https://postgr.es/m/PH0PR21MB1328189E2821CDEC646F8178D8AE9@PH0PR21MB1328.namprd21.prod.outlook.com
---
 src/backend/commands/tablecmds.c          | 60 +++++++++++++++++------
 src/test/regress/expected/alter_table.out | 39 +++++++++++++++
 src/test/regress/sql/alter_table.sql      | 25 ++++++++++
 3 files changed, 110 insertions(+), 14 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 487852a14e..f02399f699 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -3735,7 +3735,7 @@ RenameConstraint(RenameStmt *stmt)
 ObjectAddress
 RenameRelation(RenameStmt *stmt)
 {
-	bool		is_index = stmt->renameType == OBJECT_INDEX;
+	bool		is_index_stmt = stmt->renameType == OBJECT_INDEX;
 	Oid			relid;
 	ObjectAddress address;
 
@@ -3745,24 +3745,45 @@ RenameRelation(RenameStmt *stmt)
 	 * end of transaction.
 	 *
 	 * Lock level used here should match RenameRelationInternal, to avoid lock
-	 * escalation.
+	 * escalation.  However, because ALTER INDEX can be used with any relation
+	 * type, we mustn't believe without verification.
 	 */
-	relid = RangeVarGetRelidExtended(stmt->relation,
-									 is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock,
-									 stmt->missing_ok ? RVR_MISSING_OK : 0,
-									 RangeVarCallbackForAlterRelation,
-									 (void *) stmt);
-
-	if (!OidIsValid(relid))
+	for (;;)
 	{
-		ereport(NOTICE,
-				(errmsg("relation \"%s\" does not exist, skipping",
-						stmt->relation->relname)));
-		return InvalidObjectAddress;
+		LOCKMODE	lockmode;
+		bool		obj_is_index;
+
+		lockmode = is_index_stmt ? ShareUpdateExclusiveLock : AccessExclusiveLock;
+
+		relid = RangeVarGetRelidExtended(stmt->relation, lockmode,
+										 stmt->missing_ok ? RVR_MISSING_OK : 0,
+										 RangeVarCallbackForAlterRelation,
+										 (void *) stmt);
+
+		if (!OidIsValid(relid))
+		{
+			ereport(NOTICE,
+					(errmsg("relation \"%s\" does not exist, skipping",
+							stmt->relation->relname)));
+			return InvalidObjectAddress;
+		}
+
+		/*
+		 * We allow mismatched statement and object types (e.g., ALTER INDEX
+		 * to rename a table), but we might've used the wrong lock level.  If
+		 * that happens, retry with the correct lock level.  We don't bother
+		 * if we already acquired AccessExclusiveLock with an index, however.
+		 */
+		obj_is_index = (get_rel_relkind(relid) == RELKIND_INDEX);
+		if (obj_is_index || is_index_stmt == obj_is_index)
+			break;
+
+		UnlockRelationOid(relid, lockmode);
+		is_index_stmt = obj_is_index;
 	}
 
 	/* Do the work */
-	RenameRelationInternal(relid, stmt->newname, false, is_index);
+	RenameRelationInternal(relid, stmt->newname, false, is_index_stmt);
 
 	ObjectAddressSet(address, RelationRelationId, relid);
 
@@ -3810,6 +3831,17 @@ RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bo
 				 errmsg("relation \"%s\" already exists",
 						newrelname)));
 
+	/*
+	 * RenameRelation is careful not to believe the caller's idea of the
+	 * relation kind being handled.  We don't have to worry about this (at
+	 * least not until ALTER TABLE .. ADD CONSTRAINT ... USING INDEX is
+	 * implemented for partitioned tables), but let's not be totally oblivious
+	 * to it.  We can process an index as not-an-index, but not the other way
+	 * around.
+	 */
+	Assert(!is_index ||
+		   is_index == (targetrelation->rd_rel->relkind == RELKIND_INDEX));
+
 	/*
 	 * Update pg_class tuple with new relname.  (Scribbling on reltup is OK
 	 * because it's a copy...)
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index fa54bef89a..a3a18b23bf 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -232,6 +232,45 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 ERROR:  must be owner of index onek_unique1
 RESET ROLE;
+-- rename statements with mismatching statement and object types
+CREATE TABLE alter_idx_rename_test (a INT);
+CREATE INDEX alter_idx_rename_test_idx ON alter_idx_rename_test (a);
+BEGIN;
+ALTER INDEX alter_idx_rename_test RENAME TO alter_idx_rename_test_2;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%';
+        relation         |        mode         
+-------------------------+---------------------
+ alter_idx_rename_test_2 | AccessExclusiveLock
+(1 row)
+
+COMMIT;
+BEGIN;
+ALTER INDEX alter_idx_rename_test_idx RENAME TO alter_idx_rename_test_idx_2;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%'
+ORDER BY relation::regclass::text;
+          relation           |           mode           
+-----------------------------+--------------------------
+ alter_idx_rename_test_idx_2 | ShareUpdateExclusiveLock
+(1 row)
+
+COMMIT;
+BEGIN;
+ALTER TABLE alter_idx_rename_test_idx_2 RENAME TO alter_idx_rename_test_idx_3;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%'
+ORDER BY relation::regclass::text;
+          relation           |        mode         
+-----------------------------+---------------------
+ alter_idx_rename_test_idx_3 | AccessExclusiveLock
+(1 row)
+
+COMMIT;
+DROP TABLE alter_idx_rename_test_2;
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
 ALTER TABLE attmp_view RENAME TO attmp_view_new;
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 0c61604456..d9b9e4b02b 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -227,6 +227,31 @@ SET ROLE regress_alter_table_user1;
 ALTER INDEX onek_unique1 RENAME TO fail;  -- permission denied
 RESET ROLE;
 
+-- rename statements with mismatching statement and object types
+CREATE TABLE alter_idx_rename_test (a INT);
+CREATE INDEX alter_idx_rename_test_idx ON alter_idx_rename_test (a);
+BEGIN;
+ALTER INDEX alter_idx_rename_test RENAME TO alter_idx_rename_test_2;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%';
+COMMIT;
+BEGIN;
+ALTER INDEX alter_idx_rename_test_idx RENAME TO alter_idx_rename_test_idx_2;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%'
+ORDER BY relation::regclass::text;
+COMMIT;
+BEGIN;
+ALTER TABLE alter_idx_rename_test_idx_2 RENAME TO alter_idx_rename_test_idx_3;
+SELECT relation::regclass, mode FROM pg_locks
+WHERE pid = pg_backend_pid() AND locktype = 'relation'
+  AND relation::regclass::text LIKE 'alter\_idx%'
+ORDER BY relation::regclass::text;
+COMMIT;
+DROP TABLE alter_idx_rename_test_2;
+
 -- renaming views
 CREATE VIEW attmp_view (unique1) AS SELECT unique1 FROM tenk1;
 ALTER TABLE attmp_view RENAME TO attmp_view_new;
-- 
2.30.2