GEN Database: External Format
Our GEN tool imports an external RDB to a memory-resident object-relational database (ORDB):
Its external RDB format is a union of records representing tuples of different types:
Every tuple record has an integral and immutable ‘surrogate’ primary key attribute (and object id).
Different tuple types have pairwise disjoint pkey ranges.
All foreign keys (fkeys) use this surrogate pkey value to refer to their parent (container or superclass) record type.