Ticket #11181: faster-inserts-by-caching-manager.patch

django/db/models/base.py

@@ -455 +455 @@
             pk_set = pk_val is not None
             record_exists = True
             manager = cls._base_manager
+            if hasattr(cls, '_insert_manager'):
+                insert_manager = cls._insert_manager
+            else:
+                insert_manager = cls._insert_manager = cls._default_manager.extra(select={'a': 1}).values('a').order_by()
+
             if pk_set:
                 # Determine whether a record with the primary key already exists.
                 if (force_update or (not force_insert and
-                        manager.filter(pk=pk_val).extra(select={'a': 1}).values('a').order_by())):
+                        insert_manager.filter(pk=pk_val).extra(select={'a': 1}).values('a').order_by())):
                     # It does already exist, so do an UPDATE.
                     if force_update or non_pks:
                         values = [(f, None, (raw and getattr(self, f.attname) or f.pre_save(self, False))) for f in non_pks]