We will assume that the client connecting to the MDB web services is capable of using different protocols. Web client asks for _all_ Zn-containing proteins using the _sql()_ method of the XML-RPC server. XML-RPC server returns a result ID to client, then schedules query to be executed and results stored for later retrieval. Query is executed and result set stored using the assigned ID. Client uses SOAP to retrieve result. Server retrieves stored result set, and formats it as a complex structure using the appropriate XML Schema.