A framework for data warehouse federations building

Data warehouse federations are a next step in modern information storage and processing systems. They are a system of classical data warehouses connected by an integrated schema, that allows access to all the data of the source warehouses. We propose a generic approach to create a data warehouse federation, providing methods for schema integration (in order to create the federation schema), query decomposition (in order to translate the query to the federation into queries to subsequent warehouses) and result integration (to select the answer that best suits the user information need).We test this approach by creating a basic implementation and present a working example.