Organization of VMNetDB
Maintenance of efficient linked lists is a guiding principle behind the classical network and new OO databases.
GEN declares and maintains a circular list for every fkey attribute that it finds in the schema (i.e. for every 1:M relation link on the schema diagram).
When pr_load reads any database into virtual memory (VM), the links become VM address pointers. The result is a network data structure called VMNetDB.