bacwn

Datomic's immutable storage and time-travel query capabilities are awesome, and I often miss them in other DBs. But Datomic currently isn't designed for write-intensive workloads. And while you can shard Datomic's transactor and then combine multiple DBs in a query (http://nosql.mypopescu.com/post/19310504456/thoughts-about-d...), that's only going to get you so far. However, Apache Geode lets you add custom indexes so it might not be too hard to add Clojure's persistent data structures as a custom index scheme and hook in Apache Geode as a backend to Clojure Datalog: Clojure Datalog: https://github.com/fogus/bacwn Datscript: https://github.com/tonsky/datascript Clojure's Persistent Data Structures for Java: https://github.com/grignaak/clj-ds

I share your interest in the Datalog engine implementation. The free version of Datomic does include Datomic Datalog and you can certainly play with it against the normal Clojure data structures without bothering with the backend. You might be interested in Cascalog, which is a similar, datalog-style query engine designed for use on Hadoop. But it can be run locally with a play data space. The implementation is open source and you can peruse it nicely. fogus is working some on bacwn: https://github.com/fogus/bacwn which may also hold interest for you. Sooner or later I'm going to get back on the prolog-y, datalog-y chapter of ANSI Common Lisp as well.