Well, it all depends on what operations you need. exact key lookup/write? -> Easy, just use any KV store and append the version to the key, then do a ceil/floor

Well, it all depends on what operations you need. exact key lookup/write? -> Easy, just use any KV store and append the version to the key, then do a ceil/floor lookup in the KV with the key+target version. Supporting efficient range scans is hard though. EDIT: yeah, OLAP will be hard.