Abstract
In this paper, we propose an intelligent mediator that is based on XML technology for heterogeneous data source. We call it an XML Mediator or XMed for short. XMed is expected to reduce the overhead that may arise when adding a new data source and to allow uniform processing of data that may be received from different data sources. It is also to allow for dynamic connectivity to accessible data sources provided that the connection protocol is either already available with it or it can be uploaded dynamically. XMed receives requests from the client, analyzes, and forwards them to their corresponding destinations. Results are wrapped in XML and sent back to their corresponding client. It manages the users' accounts, authorization and security to facilitate the connection to the desired data source remotely. It is presumed that XMed will fulfill the role of an open system by exposing its services to any developed application. XMed maintains a knowledge base of user histories and metadata about database connections and queries. The system uses its knowledge base to assist users when accessing desired data or running queries.