Notes about the LUN file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The LUN file type is primarily associated with 'DB-MAIN' by REVER S.A.. DB-MAIN is a CASE tool dedicated to Database Application Engineering. It is designed to help developers and analysts in the development, reverse-engineering, reengineering, migration, integration, maintenance and evolution of data-centred applications.