Why do you need another database and another query language for this?
Existing cypher based databases which support typed properties (including timestamps) on relationship tables can handle this use case just fine.
Existing cypher based databases which support typed properties (including timestamps) on relationship tables can handle this use case just fine.
Most databases have a notion of logical clock to implement MVCC/transactions. So this is just a mapping. Some in the spanner family actually use a drift limited physical clock.
The second part is using an index to answer queries about facts in the past. Like what was the capital of India in 1800?
There are existing embedded graph databases which do this.
Disclosure: I maintain one.
Also "because they can" seems obligatory.