diff --git a/heat/db/sqlalchemy/api.py b/heat/db/sqlalchemy/api.py
index 10e7f5d74e..d00933e882 100644
--- a/heat/db/sqlalchemy/api.py
+++ b/heat/db/sqlalchemy/api.py
@@ -496,15 +496,18 @@ def resource_get_all_active_by_stack(context, stack_id):
 
 
 def resource_get_all_by_root_stack(context, stack_id, filters=None,
-                                   eager=True):
+                                   stack_id_only=False):
     query = context.session.query(
         models.Resource
     ).filter_by(
         root_stack_id=stack_id
-    ).options(orm.joinedload("data"))
+    )
 
-    if eager:
-        query = query.options(orm.joinedload("rsrc_prop_data"))
+    if stack_id_only:
+        query = query.options(orm.load_only("id", "stack_id"))
+    else:
+        query = query.options(orm.joinedload("data")).options(
+            orm.joinedload("rsrc_prop_data"))
 
     query = db_filters.exact_filter(query, models.Resource, filters)
     results = query.all()
diff --git a/heat/engine/service.py b/heat/engine/service.py
index 321e419972..595a8b0661 100644
--- a/heat/engine/service.py
+++ b/heat/engine/service.py
@@ -1749,12 +1749,12 @@ class EngineService(service.ServiceBase):
 
             if nested_depth:
                 root_stack_identifier = st.identifier()
-                # find all resources associated with a root stack
-                all_r = resource_objects.Resource.get_all_by_root_stack(
-                    cnxt, st.id, None, eager=False)
+                # find all stacks with resources associated with a root stack
+                ResObj = resource_objects.Resource
+                stack_ids = ResObj.get_all_stack_ids_by_root_stack(cnxt,
+                                                                   st.id)
 
                 # find stacks to the requested nested_depth
-                stack_ids = {r.stack_id for r in six.itervalues(all_r)}
                 stack_filters = {
                     'id': stack_ids,
                     'nested_depth': list(range(nested_depth + 1))
diff --git a/heat/objects/resource.py b/heat/objects/resource.py
index 2e3e6c31fb..ef4992ac50 100644
--- a/heat/objects/resource.py
+++ b/heat/objects/resource.py
@@ -264,18 +264,24 @@ class Resource(
         return dict(resources)
 
     @classmethod
-    def get_all_by_root_stack(cls, context, stack_id, filters, cache=False,
-                              eager=True):
+    def get_all_by_root_stack(cls, context, stack_id, filters, cache=False):
         resources_db = db_api.resource_get_all_by_root_stack(
             context,
             stack_id,
-            filters,
-            eager=eager)
+            filters)
         all = cls._resources_to_dict(context, resources_db)
         if cache:
             context.cache(ResourceCache).set_by_stack_id(all)
         return all
 
+    @classmethod
+    def get_all_stack_ids_by_root_stack(cls, context, stack_id):
+        resources_db = db_api.resource_get_all_by_root_stack(
+            context,
+            stack_id,
+            stack_id_only=True)
+        return {db_res.stack_id for db_res in six.itervalues(resources_db)}
+
     @classmethod
     def purge_deleted(cls, context, stack_id):
         return db_api.resource_purge_deleted(context, stack_id)