There have been countless examples on these forums of cases where OPs expected data to be returned in clustered index order when no 'order by' was specified. It's not guaranteed to happen. Most of the time it does, but you can't EVER rely on it. The optimizer is free to return rows in any oder that miximizes query efficiency when no 'order by' is specified. A new version of SQL Server can break current behavior at any time. If you want something in a particular order, the only way to guarantee it is to use 'order by'. So in the OPs case here, he should add the data he wishes to order by to the rows before he loads them into the server. Updating them once they're in the server won't guarantee he'll get what he expects.