Andy, I think we all need to be reminded every so often of the simple step we can take to go beyond just an adequate job performance and your examples...

An interesting solution but adding another column, though guaranteed to be unique, cannot guarantee checksums that will always differ. As a matter of fact, given the original issue, it...

You can find a number of posts on this subject by doing a web search on "SQL Server Checksum false positives". Something related but not discussed as much are...