Software architectural style for interoperable databases

We propose a layered and component based software architecture style which supports interoperability in multiple databases (DB). The architectural style's building blocks and its constraints are described and the deployment of two design patterns outlined. Components placed in our architectural layers exhibit a linear topology and request/reply processing style. The constraints include communications between components which are not in the adjacent architectural layers and extension of the intuitive many : one bindings between components towards many : many. We comment on similarities with mediation architectures and outline some implementation issues