Query Mapping and Transformation Techniques for Problem Solving with Multiple Knowledge Servers

: This paper describes a technique for information mediation when multiple heterogeneous knowledge and data servers are to be accessed during query processing. One problem is building an intelligent interface between each knowledge server (KS) and its processor (KP); and the second is to provide interoperability among multiple KP/KS so that a query may be answered using information from multiple sources. We present example scenarios which highlight these problems and then outline query mapping and transformation techniques that are applicable. The techniques for solving the interoperability problems involve representations in some canonical form. This includes a canonical representation (CR) corresponding to each KP/KS pair and a merged CR (MCR) to represent the mapping among the CRs. The MCR and CRs include relevant information obtained from a source query, and heterogeneous mapping (het-map) information, for all possible mappings among the multiple servers. The knowledge in the canon..