Or maybe even auto-never-correct ......

Please detail out the exact steps you're taking to perform the export, and then provide any one value that's causing the error...

And I agree with Kevin on the minimally logged inserts, given that 120 million row expectation.   Also, if you have to insert that many rows, could you possibly lock that...

Going to need to see an actual execution plan for this.   Not a fan of the timestamp data type, but I'm not sure if that's really a problem or not.  ...

Well... that describes the basics about your data, but doesn't entirely convey the hierarchy or the kinds of row quantities you're dealing with.  Also hidden from view is the overall...

No way to know exactly what's taking place in your environment, but some things that "might" play a role:

1.) disk fragmentation for the spindles where the partitions are...

Just looking at your presentation layer doesn't do anything to tell me how your data is actually structured, and given that there are always multiple ways to "skin the cat",...