Hi Shen - The state-of-the-art spatiotemporal database systems are based on topological embedding and geometric interval computation (hyper-rectangle cell/simplicial complex https://en.wikipedia.org/wiki/Simplicial_complex).

And while I don't know of any open-source systems based on this design, SpaceCurve is publicly available (http://www.spacecurve.com http://www.jandrewrogers.com/2015/10/08/spacecurve/) , and I've heard systems like this exist within IBM and Google.

Have you looked into this approach?

Look forward to it!