A group of venture capital investors have hired you to review the technical design of a service that will be developed by a startup company seeking funding. The startup plans to collect data from sensors attached to vehicles. The data will be used to predict when a vehicle needs maintenance and before the vehicle breaks down. Thirty sensors will be on each vehicle. Each sensor will send up to 5K of data every second. The startup expects to start with hundreds of vehicles, but it plans to reach 1 million vehicles globally within 18 months. The data will be used to develop machine learning models to predict the need for maintenance. The startup is planning to use a self-managed relational database to store the time-series data. What would you recommend for a time-series database?