Elasticsearch 5.0.0 released (elastic.co)

I'm particularly excited about the inclusion of Lucene 6's KD trees, allowing for up to 8-dimensional geometric search. Normally you'd use that for geolocation stuff, which is fine, but I'm excited about the possible applications for using it to index document embeddings!

Related, Lucene (and thus Elasticsearch) moved to BM25, which can be understood relative to the traditional TF*IDF here: http://opensourceconnections.com/blog/2015/10/16/bm25-the-ne...