The 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 called WOL (Well-founded Object Logic) for specifying such transformations, and its implementation in a system called Morphase (an "enzyme" for morphing data). 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.
||Index Terms- distributed databases; WOL; database transformations; nonstandard database constraints; heterogeneous databases; data management; database schema evolution; declarative language; Well-founded Object Logic; Morphase; data morphing; complex data structures; object-oriented databases; complex relational databases
S.B. Davidson, A.S. Kosky,
"WOL: a language for database transformations and constraints,"
13th International Conference on Data Engineering (ICDE'97),