I'm still reading about RR*-tree, GiST and the PostgreSQL source code to have a better idea on my proposal. Meanwhile, I have a very basic and simple question:
Since the chooseSubtree() algorithm in both R*-tree and RR*-tree are heuristic and somehow greedy (e.g. pick the MBB that needs to enlarge the least), is it possible to apply machine learning algorithm to improve it? The only related reference I got is to use deep learning in database join operation (https://arxiv.org/abs/1808.03196). Is it not suitable to use machine learning here or someone already did?
