--- a/script/lib/iri_tweet/models.py	Mon Nov 21 11:53:42 2011 +0100
+++ b/script/lib/iri_tweet/models.py	Tue Nov 29 15:41:15 2011 +0100
@@ -103,7 +103,7 @@
     id_str = Column(String)
     contributors = Column(String)
     coordinates = Column(String) 
-    created_at = Column(DateTime)
+    created_at = Column(DateTime, index=True)
     favorited = Column(Boolean)
     geo = Column(String)
     in_reply_to_screen_name = Column(String)