diff -r 0cb160fd3cdf -r bfc8e1831290 server/ssplanner.py
--- a/server/ssplanner.py	Sun Aug 16 20:42:33 2009 +0200
+++ b/server/ssplanner.py	Mon Aug 17 18:25:57 2009 +0200
@@ -482,7 +482,7 @@
         repo = session.repo
         edefs = {}
         # insert relations
-        attributes = [relation.r_type for relation in self.attribute_relations]
+        attributes = set([relation.r_type for relation in self.attribute_relations])
         for row in self.execute_child():
             for relation in self.attribute_relations:
                 lhs, rhs = relation.get_variable_parts()