Hi hackers, I've implemented subj algorithm as PostgreSQL extension. It looks like this realization is such as fast as R-Tree but sufficiently more simple & compact. Here (https://habrahabr.ru/post/319810/) or here ( http://www.google.com/translate?hl=en&ie=UTF8&sl=auto&tl=en&u=https%3A%2F%2Fhabrahabr.ru%2Fpost%2F319810%2F ) you can find the algirithm description and some benchmarks in comparison with GiST R-Tree.
The extension sources are uploaded at https://github.com/bmuratshin/zcurve/tree/raw-2D under the BSD license. Feel free to connect with me if you have some questions. Regards, Boris
