Web services provide interfaces to web resources described by
WSDL
    interface definitions. The Web Service MEDiator system (WSMED) enables
    querying data accessible through web services. WSMED allows web service
    meta-data to be automatically extracted from any WSDL description.
    Then views can be created in terms of the imported meta-data and
    queried using SQL. To enhance query performance, WSMED permits to
    complement the automatically extracted web service meta-data with
    semantic enrichments. A WSMED prototype is being evaluated over existing
    web services to verify the effectiveness of the approach. It is being
    investigated how semantic enrichments and other query optimization
    methods are useful for efficient querying of mediated web services