[nine_k]

Speaking of which, if you try an actual System V in an emulator, or look at C code in K&R style, certain progress, as in "much more actually usable", can be noticed.

While persisting key architectural ideas certainly has benefits, so does evolving their implementations.

[kunley]

Yes I agree that implementations must evolve. Still, there are cases where old architectures are just brilliant.

Having said that, I need to add, I am not an expert to say MVCC is good enough to be considered equally good like other write-concurrency mechanism in SQL databases. My example was given to just have a caution when judging, especially that the original counterexample had mentioned notoriously bad architectures (hello, MySQL...)