03-05-2005, 10:07 AM
One advantage of non-keyed physical files is to maintain consistency with SQL. SQL tables (files) are not keyed. You need a view (logical file) to access a table by key. Other advantages would probably be weight by personal preferences. Non-keyed physical files require you to have two objects when one would do. You can also tend to overlook the existence of the physical file since you may never need to reference it. Referential integrity has to do with foreign keys. When a record in file A contains key fields for accessing file B you want to be sure the record in file B is not deleted without taking appropriate action on file A. To not do so could leave file A as a 'orphan', since foreign keys generally link children to their parent. My limited knowledge of COBOL prevents me from commenting our your other questions.