Long after we finally delivered our much anticipated Next Generation Schema, we’re finally ready to dive in and get to work on our New Edit System. You may recall that during the NGS re-write we opted to not tackle the re-write of our edit system. Instead, we decided to do the edit system overhaul once NGS became stable.
We finally reached this point when Ollie, Warp and I met in London last month to discuss this new project. We had a productive meeting reviewing all of the research that Ollie had done over the past months. We improved the terminology here and then, but in general approved for Ollie to continue his work. Part of his work was to write about it so that our users can get familiar with the concepts that will come about in NES.
Ollie had started blogging about that on his own blog:
If you’re interested in the New Edit System, please take a moment to read these posts and consider following Ollie’s blog.
MetaBrainz Blog 
IMO, if you need this much big changes in database, you should instead try to use another alternative, like NoSQL systems.
Honestly, I don’t think those systems are completely capable of replacing SQL databases, but still they can work great together on some conditions like yours.
So, I am suggesting to move the complete edit system to a NoSQL database, where system does versionning automatically.
Of course, this is just my two cents. I’m sure you guys already thought about alternatives and probably have a good reason not to choose it.
I wanted to mention it, just for the records.