It's a fun language to play around with and everything. Just have never seen anyone us it at scale in the industry other than folks doing research/academia.
"Datalog is a declarative logic programming language that syntactically is a subset of Prolog." [1]
"Datomic is a distributed database and implementation of Datalog.". Datomic seems to be quite succesful [2].
Related to datomic, I'm trying to learn Datascript these days ("An immutable in-memory database and Datalog query engine in Clojure and ClojureScript.") [3].
1: https://en.wikipedia.org/wiki/Datalog