From the blog post - https://dgraph.io/blog/post/badger-over-rocksdb-in-dgraph/
3D Access (Key-Value-Versions)
Badger is probably the only key-value database which exposes the versions of the values to the user. When opening a Badger DB, you can set the
options.NumVersionsToKeep . We set this by default to 1 in Badger, but in Dgraph, we set this to infinity.
How can I access the Key-Value-Versions history from within Dgraph…??