Pretty nice tool :-)

But what if the data store would do all of that already?

  - retaining the history of your data:
    - free deduplication through copy on write and sharing unchanged structures
    - further store space savings through page-level versioning (not all records in a page have to be written: just the changed/inserted/deleted ones plus depending on the algorithm a few more to fast track it's reconstruction)
    - read and write performance is balanced using a sliding snapshot algorithm: This avoids having to read long chains of incremental page changes and it avoids write peaks from intermittant full page snapshots. Instead they get trailed over a few (usually three or four revisions).
    - the sorage manager stores timestamps for all revision in a RevisionRootPage, which itself is indexed

  - Optional commit author and message
  - Reverting to and committing a past "good" revision is just adding a few bytes to index a new RevisionRootPage which references the past revision data (simple pointer)
  - You can diff taking rolling hashes into account
  - Currently I'm working on a diffing JSON format and a web front-end to display these in special space filling approaches
  - Sophisticated time travel queries
  - typed, user-defined and versioned secondary index structures (based on AVL trees)
  - a path summary kept up to date always
  - a lot of metadata stored and kept up to date for each record/node

It's already implemented in https://sirix.io / https://github.com/sirixdb/sirix

I'm working on getting it stable, but help from you, the Open Source community is always needed :-)