diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 65e271a..1380ab6 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3873,6 +3873,7 @@ InitTempTableNamespace(void)
 	 */
 	myTempNamespace = namespaceId;
 	myTempToastNamespace = toastspaceId;
+	MyProc->tempNamespaceId = namespaceId;
 
 	/* It should not be done already. */
 	AssertState(myTempNamespaceSubID == InvalidSubTransactionId);
@@ -3903,6 +3904,7 @@ AtEOXact_Namespace(bool isCommit, bool parallel)
 		{
 			myTempNamespace = InvalidOid;
 			myTempToastNamespace = InvalidOid;
+			MyProc->tempNamespaceId = InvalidOid;
 			baseSearchPathValid = false;	/* need to rebuild list */
 		}
 		myTempNamespaceSubID = InvalidSubTransactionId;
@@ -3955,6 +3957,7 @@ AtEOSubXact_Namespace(bool isCommit, SubTransactionId mySubid,
 			/* TEMP namespace creation failed, so reset state */
 			myTempNamespace = InvalidOid;
 			myTempToastNamespace = InvalidOid;
+			MyProc->tempNamespaceId = InvalidOid;
 			baseSearchPathValid = false;	/* need to rebuild list */
 		}
 	}
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 702f8d8..87cd67c 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -347,6 +347,7 @@ static void av_sighup_handler(SIGNAL_ARGS);
 static void avl_sigusr2_handler(SIGNAL_ARGS);
 static void avl_sigterm_handler(SIGNAL_ARGS);
 static void autovac_refresh_stats(void);
+static bool backend_uses_temp_namespace(int backendID, Oid namespaceID);
 
 
 
@@ -2074,10 +2075,8 @@ do_autovacuum(void)
 
 			backendID = GetTempNamespaceBackendId(classForm->relnamespace);
 
-			/* We just ignore it if the owning backend is still active */
-			if (backendID != InvalidBackendId &&
-				(backendID == MyBackendId ||
-				 BackendIdGetProc(backendID) == NULL))
+			/* We just ignore it if the owning backend is still active and using the temp schema */
+			if (!backend_uses_temp_namespace(backendID, classForm->relnamespace))
 			{
 				/*
 				 * The table seems to be orphaned -- although it might be that
@@ -2248,9 +2247,7 @@ do_autovacuum(void)
 			continue;
 		}
 		backendID = GetTempNamespaceBackendId(classForm->relnamespace);
-		if (!(backendID != InvalidBackendId &&
-			  (backendID == MyBackendId ||
-			   BackendIdGetProc(backendID) == NULL)))
+		if (backend_uses_temp_namespace(backendID, classForm->relnamespace))
 		{
 			UnlockRelationOid(relid, AccessExclusiveLock);
 			continue;
@@ -3348,3 +3345,32 @@ autovac_refresh_stats(void)
 
 	pgstat_clear_snapshot();
 }
+
+/*
+ * backend_uses_temp_namespace
+ *		Check if a backend is using a given temp schema
+ */
+static bool
+backend_uses_temp_namespace(int backendID, Oid namespaceID)
+{
+	PGPROC		*proc;
+
+	if (backendID == InvalidBackendId ||
+		backendID == MyBackendId)
+		return false;
+
+	/* Is the backend alive? */
+	proc = BackendIdGetProc(backendID);
+	if (proc == NULL)
+		return false;
+
+	/* Is the backend connected to this database? */
+	if (proc->databaseId != MyDatabaseId)
+		return false;
+
+	/* Does the backend own the temp schema? */
+	if (proc->tempNamespaceId != namespaceID)
+		return false;
+
+	return true;
+}
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 6f30e08..6f9aaa5 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -371,6 +371,7 @@ InitProcess(void)
 	MyProc->backendId = InvalidBackendId;
 	MyProc->databaseId = InvalidOid;
 	MyProc->roleId = InvalidOid;
+	MyProc->tempNamespaceId = InvalidOid;
 	MyProc->isBackgroundWorker = IsBackgroundWorker;
 	MyPgXact->delayChkpt = false;
 	MyPgXact->vacuumFlags = 0;
@@ -552,6 +553,7 @@ InitAuxiliaryProcess(void)
 	MyProc->backendId = InvalidBackendId;
 	MyProc->databaseId = InvalidOid;
 	MyProc->roleId = InvalidOid;
+	MyProc->tempNamespaceId = InvalidOid;
 	MyProc->isBackgroundWorker = IsBackgroundWorker;
 	MyPgXact->delayChkpt = false;
 	MyPgXact->vacuumFlags = 0;
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 5c19a61..fd52376 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -200,6 +200,8 @@ struct PGPROC
 	PGPROC	   *lockGroupLeader;	/* lock group leader, if I'm a member */
 	dlist_head	lockGroupMembers;	/* list of members, if I'm a leader */
 	dlist_node	lockGroupLink;	/* my member link, if I'm a member */
+
+	Oid			tempNamespaceId;	/* OID of temp schema this backend is using */
 };
 
 /* NOTE: "typedef struct PGPROC PGPROC" appears in storage/lock.h. */