US Patent 7899839 Query rewrite with a remote object

A query statement, issued to a local database server, is re-written. The query references at least one of a first or a second object. The first object is remote with respect to the local database server, for accessing a first materialized view that is local or remote with respect to the local database server. The second object is local with respect to the local database server, to access a second materialized view that is remote with respect to the local database server. Rewriting the query can include dynamically tracking a staleness state associated with one or more of the materialized views.