Universal Contextual Queries in Database Networks.
Moira C. Norrie, Darren J. Kerr · 1995
We present a method for access to information in remote databases without any prior form of schema integration. The approach is based on a generalisation of the ideas of universal relation interfaces to other data models. Queries are mapped to a universal data model which has a minimal structure. Remote systems try to interpret the query in the context of their local schemas. To assist in the selection of possible query interpretations, contextual information is transferred to the remote systems along with the universal queries. 1 Introduction Developments in communication technologies provide the potential for world-wide database networks [Bro92]. The challenge to the database community is how to exploit these networks to provide global, cooperative information services. A key question is how to deal with the issues of semantic heterogeneity where such large-scale distribution is involved. Existing solutions do not adapt easily to database networks in which there are a very large num...