Davidson, Susan BKosky, Anthony S2023-05-222023-05-221997-04-072007-06-04https://repository.upenn.edu/handle/20.500.14332/8758The need to transform data between heterogeneous databases arises from a number of critical tasks in data management. These tasks are complicated by schema evolution in the underlying databases, and by the presence of non-standard database constraints. We describe a declarative language, WOL, for specifying such transformations, and its implementation in a system called Morphase. WOL is designed to allow transformations between the complex data structures which arise in object-oriented databases as well as in complex relational databases, and to allow for reasoning about the interactions between database transformations and constraints.Presentation