Query Processing in a Heterogeneous Retrieval Network
The concept of a large-scale information retrieval network incorporating heterogeneous retrieval systems and users is introduced, and the necessary components for enabling term-based searching of any database by untrained end-users are outlined. We define a normal form for expression of queries, show that such queries can be automatically produced, if necessary, from a natural-language request for information, and give algorithms for translating such queries, with little or no loss of expressiveness, into equivalent queries
on both Boolean and term-vector type retrieval systems. We conclude with a proposal for extending this approach to arbitrary database models.