What is a Time-Series Database?

In many cases, enormous amounts of data are received at a high rate and must be saved. Financial markets, trading companies, hedge funds, and stock exchanges are regularly updated with real-time market data and activity. Each transaction performed per product is used to make trading decisions. The data itself is critical in each of the instances above, but the timestamp at which it is generated is also critical. This timestamp enables us to get insights from data in near real-time or later in batch processing. Time-series databases (TSDB) are used to solve this problem. A TSDB is a database that is built and optimized to work with high data rates and time stamps. TSDBs are specifically intended to handle time-series data or time-stamped data. Time-series data can be gathered from a variety of events or measurements, but the data is always collected across several periods of time rather than single events.

The image above displays the trade value on various days of the month. A TSDB stores the data as (time, value) pairs. When data is stored this way, evaluating time series data is simple. Concurrent series, or many variables being measured at the same time, can also be managed with this database. For example, in the image below, there is a value for Air Quality Index (AQI) and a density value. Time, however, is the most significant variable in a time-series database.