GEN Database: Import/Export
GEN creates two schema-based import/export utilities:
pr_load parses tuples and imports an external RDB into a memory-resident object-relational database (ORDB);
pr_dump exports the modified ORDB back to the persistent external RDB.
During import, fkeys are augmented or replaced by direct parent pointers plus first-child and next-sibling object reference pointers. These are constructed from fkey names following strict GEN naming conventions, Super- and sub-class objects are also connected in the same way.
This results in an internal ORDB format which is a set of multiply-threaded linked lists from each parent through each of its child-sets, that supports parent-child JOINs.