Binning/Grouping large result sets efficiently

Hi, I am still learning about the performance implications of Lucene's APIs when aggregating large result sets. It seems that some cases require a deeper understanding of Lucenes internals and the use of not-so-front-facing APIs. For some time I am struggling with poor grouping/ aggregation per

SpatialPrefixTree - which one should I pick for 2D Points?

Lucene offeres a few SpatialPrefixTree implementations for indexing geographic data types which make use of Geohash, Google S2 and Quadtrees. * GeohashPrefixTree * PackedQuadPrefixTree * QuadPrefixTree * S2PrefixTree Which one is recommended for indexing 2D-Point data? Kind regards, Matthias