I can tell HN that in about a month we'll be open-sourcing the in-memory data grid that's at the heart of the SpaceBase grid. It's an IMDG different from all others, as it has some very unique performance characteristics that make it suitable for certain use-cases.
Can Spacebase support locations which are Parameterized in time? For example, could one have a solar system whose planets move according to equations based on GMT?
You would need to update the locations according to the equations yourself, so that at any given moment (if you update all of them in one atomic transaction), their locations are up to date. We have not yet seen a compelling reason to support spatiotemporal objects, but this is something we might consider.
Note, however, that SpaceBase truly shines when there is a large number of objects and a lot of queries/transactions.
