This is all controlled by the controls DictionaryBinding property. Design time . Referenced dictionary definitions are stored in the controls property stream and are read into memory when the control is loaded. User defined . Definitions are stored in local memory for fast access.
Data binding is available on defined fields.
File bound . Data binding is available for any key or key segment. Even SQL queries and find methods can be performed using these pseudo fields. Unbound file . Reading and writing of records is performed as a byte stream.