Looking into RethinkDB. A post caught my eye that it was recently rewritten in Lisp. 

After many heated debates, I remembered a phrase drilled into to me by an ex-coworker I deeply respect. He always said: “Don’t guess. Measure.” We decided to take a measured approach and use data and logical reasoning instead of emotional arguments. Because of the immense expressive power of both programming languages, we could develop two prototypes in a matter of days, and measure the performance with our internal benchmarking toolkit. Mike rewrote RethinkDB in Haskell, and I rewrote it in Common Lisp.

The features look very compelling:

No more seek latency.

RethinkDB is designed to be extremely fast, and implements powerful features that are cumbersome and inefficient with rotational storage. Today’s databases heavily optimize to account for high seek latency—the time it takes for a rotational drive’s platter to move. RethinkDB takes full advantage of solid-state drives, making traditional data storage layouts unnecessary.

Databases the way they were meant to be.

RethinkDB borrows ideas from many diverse areas of computer science. Because we’re no longer constrained by the limitations of rotational drives, we can bring our ideas to reality and build a database the way it was always meant to be built.

http://www.rethinkdb.com/learn-more/