Combining fuzzy information from multiple systems

Garlic (CHS+95, CHN+95) is a multimedia information system designed with the ability to integrate data that resides in different database systems as well as a variety of non-database data servers. This paper discusses the semantics of Garlic queries. As a first step in dealing with the associated issues, an optimal algorithm for evaluating an important class of Garlic queries is presented. The problem of the mismatch in semantics is then discussed in more detail, and a simple solution is given. Various operators in the literature for conjunction and disjunction are considered, focusing on the properties of interest, namely strictness and monotonicity. Algorithms for evaluating the conjunction of atomic queries are presented.