In information-integration systems, source relations often have limitations on access patterns to their data; i.e., when one must provide values for certain attributes of a relatio...
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 answering queries over sources with limited access patterns. The problem is to decide whether a given query Q is feasible, i.e., equivalent to an executable...