I have a PredictionServer timeout when issuing a query for a non-existent user. We can only use a weeks worth of data so doing the db clean every day to drop events that are too old, without messing with $whatever events. Users are never created with $set. So we are asking for a list of event types for a specific user. The user, as I said, does not exist because they have no events yet. The PredictionServer times out after 20 seconds. Very odd. Could trimming events by date do something that screws up an index causing a full scan of events?
