I don't know how you could call the latest version of any of the major databases "traditional" Oracle has done MVCC for many years, as has Postgres. The canoni

I don't know how you could call the latest version of any of the major databases "traditional" Oracle has done MVCC for many years, as has Postgres. The canonical paper on optimistic concurrency control for DBs is from 1981 (http://www.seas.upenn.edu/~zives/cis650/papers/opt-cc.pdf http://www.seas.upenn.edu/~zives/cis650/papers/opt-cc.pdf). I didn't follow the rest of your comment, I'm afraid -- I was just saying that I didn't see how using append-only storage immediately makes concurrency control a non-issue. The comments from the RethinkDB guys upthread support that: not supporting concurrent writers makes your concurrency control much more straightforward.