Persistent Databases
Persistence means that pkeys and fkeys are preserved during export to mass storage or remote sites and re-import by the same or another DataBase Management System (DBMS)
A relational database (RBD) supports inter-object relationships by foreign key (fkey) fields. These are both user-visible and persistent: they get saved in mass storage if the program terminates.
The process of mapping RDB pkey-fkey associations to and from C++ pointers is called ‘pointer swizzling’.