The Schema Evolution and Data Migration Framework of the Environmental Mass Database IMIS

This paper describes a framework that supports the simultaneousevolution of object-oriented data models andrelational schemas with respect to a tool-supported object-relationalmapping. The proposed framework accounts fornon-trivial data migration induced by type evolution fromthe outset. The support for data migration is offered onthe level of transparent data access. The framework consistsof the following integrated parts: an automatic modelchange detection mechanism, a generator for schema evolutioncode and a generator for data migration APIs. Theframework has been concepted in the IMIS project. IMISis an information system for environmental radioactivitymeasurements. Though the indicated domain especially demandsa solution like the one discussed in this paper, theachievements are of general purpose for multi-tier systemarchitectures with object-relational mapping.