LANSA uses access routes to describe relationships between tables in a database. They provide information about the database map or schema that can be used by the LANSA development environment and other products. Access routes also support Predetermined Join Columns which are a special type of virtual column.
Also See
3.6 Predetermined Join Column (PJC) Definitions
Access Route Tab in the User Guide.
Access Route Development in the Developer Guide.
Predetermined Join Column Development in the Developer Guide.