Datomic greatly simplifies it. You just give it a timestamp when you get the db handle to query on, and it returns a virtual copy of the db at that moment. They

Datomic greatly simplifies it. You just give it a timestamp when you get the db handle to query on, and it returns a virtual copy of the db at that moment. They leverage the time management to make that an immutable database that you can only add to. So you have a full trace of everything ever added, and easy time travel within it, on the house. But I don't think the embeddings themselves can work like that. You'd have to train them on the corpus at each point in time. So it wouldn't be practical to query on fine time intervals because of the large amount of data or training time. It would be nice to be wrong about this.