Local relational model: a logical formalization of database coordination

We propose a new data model intended for peer-to-peer (P2P) databases. The model assumes that each peer has a (relational) database and exchanges data with other peers (its acquaintances). In this context, one needs a data model that views the space of available data within the P2P network as an open collection of possibly overlapping and inconsistent databases. Accordingly, the paper proposes the Local Relational Model, develops a semantics for coordination formulas. The main result of the paper generalizes Reiter's characterization of a relational database in terms of a first order theory [1], by providing a syntactic characterization of a relational space in terms of a multi-context system. This work extends earlier work by Giunchiglia and Ghidini on Local Model Semantics [2].