Also worth checking out OmniSci, (https://www.omnisci.com), formerly known as MapD, which can query and visualize tens of billions of geospatial records in sub-second timeframes. See here for an interactive demo of 11.6 billion ship AIS records: https://www.omnisci.com/demos/ships. Note that the backend database is open source, but the rendering engine and web front end are part of the paid offering. [Disclaimer: I work there]