diff --git a/src/ralph/admin/mixins.py b/src/ralph/admin/mixins.py
index c0496a115a..f359061786 100644
--- a/src/ralph/admin/mixins.py
+++ b/src/ralph/admin/mixins.py
@@ -421,9 +421,6 @@ def get_export_queryset(self, request):
         )
         if resource_prefetch_related:
             queryset = queryset.prefetch_related(*resource_prefetch_related)
-        # cast to list to consider all prefetch_related (django-import-export
-        # use queryset.iterator() to "save memory", but then for every row
-        # sql queries are made to fetch all m2m relations)
         return list(queryset)
 
     def get_export_resource_class(self):
diff --git a/src/ralph/data_center/admin.py b/src/ralph/data_center/admin.py
index 32625631ae..f2d72b5e9c 100644
--- a/src/ralph/data_center/admin.py
+++ b/src/ralph/data_center/admin.py
@@ -490,13 +490,6 @@ class DataCenterAssetAdmin(
         }),
     )
 
-    def get_export_queryset(self, request):
-        return DataCenterAsset.polymorphic_objects.select_related(
-            *self.list_select_related
-        ).polymorphic_prefetch_related(
-            DataCenterAsset=['tags', 'ethernet_set__ipaddress', 'parent__ethernet_set__ipaddress'],
-        )
-
     def get_multiadd_fields(self, obj=None):
         multiadd_fields = [
             {'field': 'sn', 'allow_duplicates': False},
diff --git a/src/ralph/data_importer/resources.py b/src/ralph/data_importer/resources.py
index 6f4faf5671..4e9634fab7 100644
--- a/src/ralph/data_importer/resources.py
+++ b/src/ralph/data_importer/resources.py
@@ -306,8 +306,16 @@ class DataCenterAssetResource(ResourceWithPrice, RalphModelResource):
     class Meta:
         model = physical.DataCenterAsset
         select_related = (
+            'model__manufacturer', 'model__category',
             'service_env__service', 'service_env__environment',
             'rack__server_room__data_center',
+            'configuration_path',
+            'property_of',
+            'parent',
+            'budget_info',
+        )
+        prefetch_related = (
+            'tags', 'ethernet_set__ipaddress', 'parent__ethernet_set__ipaddress',
         )
         exclude = ('content_type', 'asset_ptr', 'baseobject_ptr', 'connections')