CrateDB + Grafana
CrateDB is a hyper-fast opensource distributed database technology that combines the best out of the SQL and NoSQL worlds. It supports the PostgreSQL wire protocol for easy integration with many data engineering tools.
Grafana is an opensource tool that helps build real-time dashboards, graphs, and all sorts of data visualizations. With Grafana you can create, explore, and share all of your data through flexible dashboards.