[ExpiredLink]

> Functional programming is very closely tied to the notion of immutable data. "Don't modify data in place" is one of the pillars of the functional model.

I don't think the Lisp fans here at HN agree.

> Datomic is much more than a time-series, although that's the aspect that arguably makes it "functional."

Not really. Time-series are not 'functional' by any stretch of the imagination.

BTW, an add-on to Hibernate, the (in)famous OR-mapper, tries to do something similar: http://docs.jboss.org/envers/docs/index.html

[cmoscoso]

It's a functional database since it allows you to create database applications using functional programming.