Lars, could you shed a little more light on the usage of the $trexexternalkey$ column? In the VizPlan I can see that this is referenced quite a but during join operations, and looking at the contents it is looks to be the concatenation of the keys of a given table. there is also some type of prefix involved (10, 2, 3, etc) that is not obvious for me.
Thanks for all the awesome info!
Justin