It is very relevant, Jun ... in fact hopefully Lars will see this because he's planning to modify a couple of his packages to use the CR and I hinted to him that developing some Tcl API stuff might be a good think to investigate while he does so (and I can help a bit, I think). If he had some of your work in hand it would very likely save time and effort.
I think the difference between "live revision" and "latest revision" is clear enough that one rarely needs the PL/SQL fallback. It's been a bit blurry in the original implementation of the CR in that some code operates on the "latest revision" if no "live revision" is available, but I'd rather tighten up our definition of what these concepts mean and avoid the PL/SQL sugar - because mostly it is just sugar and hiding the fact that either "live" or "latest" may be returned seems a bit confusing. If you want it use COALESCE in the query where it will be immediately obvious to the next person who has to figure out what your query does.
Just my thoughts.
