"Database system is one of the core foundation courses for computer-related majors. So everyone should be familiar with databases, especially relational databases. But in the industrial world, there is a kind of database which has become the hottest branch recently, which is the time series database. As the name suggests, this kind of database is used to deal with time series data. In fact, time-series data can be seen everywhere in our life, such as the readings of electricity and water meters . We will record them once in a while along with the time stamp at that time. The price changes of stocks, the system should also be recorded on time. The various sensors on new energy vehicles produce typical time-series data, which provide support for intelligent driving and safe driving. And with the popularity of 5G and the development of IoT technology, connected devices and the data generated by these devices are growing exponentially. "