Updating defined relations
Ibrahim Osman · 1979 International Workshop on Managing Requirements Knowledge (MARK) · 1979
Some relational data base systems 1 such as PRTV 2 and SEQUEL allow the user to create his own relations (logical files) as subsets of the main data. With such a facility the user may express his own view of the data in terms of the relations he creates. If a large number of such relations are created, disc storage space problems and other maintenance difficulties can arise.