Distributing semantic constraints between heterogeneous databases

In recent years, research about distributing databases over networks has become increasingly important. Here we concentrate on the issues of interoperability of heterogeneous DBMSes, and enforcing integrity across a multi-database made in this fashion. This has been done through a cooperative project between Aberdeen and Linkoping universities, with database modules distributed between the sites. In the process we have shown the advantage of using DBMSes based on variants of the Functional Data Model, which has made it remarkably straightforward to interoperate queries and schema definitions. Further, we have used the constraint transformation facilities of P/FDM to compile global constraints into Active Rules installed locally on one or more AMOS servers. We present the theory behind this and the conditions for it to improve performance.