Differentiate historical data from different plants

We are publishing data from different plants to MQTT broker (Cirrus Link Distributor module) installed in the central gateway. This central gateway is connected to the database server where we want to store the ‘subscribed’ historical data.
Using Ignition’s Tag Historian how can we differentiate between the data coming from different plants? Tag Historian uses own tables to store the data, how can we add the identity of each plant to these values?