Historian

A historian is the time series database that stores every measurement and event a SCADA or energy management system collects, so operators can chart, audit, and report on what the plant did.

Each stored value carries the device, the register or point, the timestamp, and the quality of the reading. Historians are optimized for appending readings at high rates and reading them back by time range. In a storage plant the historian answers questions like how much energy was discharged last month, what state of charge the battery held at the peak, and when an alarm first appeared.

Also called: Data historian, Time series database