One of the more advanced, but very useful, features of a tabular datasource in P2 Server is a concept known as a System Identifier. This enables P2 Server to translate an entity name in P2 Server, to the equivalent name in each of the source systems.
For example, say we have an entity in P2 Server, called Well_1. This same well may be known as W1 in P2 Production and Well1 in Qbyte. Since these are different names, how can we tie these all back together? In P2 Server we can create a mapping between an entity, and an equivalent name in each datasource (so we can have one mapping for each datasource).
When you request data for Well_1, from the P2 Production datasource, P2 Server will substitute the entity name Well_1 with W1 in the SQL statement being executed in the dataset. When the data is returned, P2 Server automatically adds an extra column to the returned data, with the original entity name included, completing the conversion in both directions.