Query Planning with Disjunctive Sources
Oliver M. Duschka, Michael Genesereth · 1998
We examine the query planning problem in information integration systems in the presence of sources that con-tain disjunctive information. We show that datalog, the languageof choice for representing query plans in infor-mation integration systems, is not sufficiently expres-sive in this case. We prove that disjunctive datalogwith inequality is sufficiently expressive, and present a con-structionof query plans that are guaranteed to extract all available information from disjunctive sources. 1