Then you may be interested in this paper which shows how to turn any purely functional data structure into an MVCC database. https://www.cs.cmu.edu/~yihans/pap

Then you may be interested in this paper which shows how to turn any purely functional data structure into an MVCC database. https://www.cs.cmu.edu/~yihans/papers/concurrency.pdf https://www.cs.cmu.edu/~yihans/papers/concurrency.pdf