set these up as None, the comprehensive solution here is

in 0.8, [ticket:2498]

diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index f3d05cac279d6a1759e5918074e3b0575bd75119..c93f390dbae8c5185a9b416a51939949ade2c113 100644 (file)
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -351,6 +351,8 @@ class DefaultExecutionContext(base.ExecutionContext):
     result_map = None
     compiled = None
     statement = None
+    postfetch_cols = None
+    prefetch_cols = None
     _is_implicit_returning = False
     _is_explicit_returning = False