Conceptual-External Mapping:

Conceptual-External Mapping: An external-conceptual mapping defines the correspondence between a particular external view and conceptual view for representing the data in efficient manner. The external-conceptual mapping tells the DBMS which objects on the conceptual level correspond to the objects requested on a particular user’s external view for information representation in the same data file. If changes are made to either an external view or conceptual view, then mapping must be changed accordingly in the data file of the same organization. It is an important mapping in database