A universal model of a database D and a set Σ of integrity constraints is a database that extends D, satisfies Σ, and is most general in the sense that it contains sound and co...
We study the problem of e cient maintenance of materialized views that may contain duplicates. This problem is particularly important when queries against such views involve aggre...
In a recent paper by Hellerstein [15], a tight relationship was conjectured between the number of strata of a Datalog¬ program and the number of “coordination stages” require...
In the study of data exchange one usually assumes an openworld semantics, making it possible to extend instances of target schemas. An alternative closed-world semantics only move...
Given a drug under development, what are other drugs or biochemical compounds that it might interact with? Early answers to this question, by mining the literature, are valuable f...