My first thought. And then I realized that the talk is from 2015, so I wonder if there was cross pollination between people at the time (datomic was released in 2012 according to wikipedia, so it's plausible it predates Martin's ideas but I don't know)

https://news.ycombinator.com/item?id=20937215

The concept is even older than that.

Yeah, like 15th century old.

More like 5th or 6th century BCE ;-)