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 pro-poses the Local Relational Model, develops a semantics for coordination formu-las. The main result of the paper generalizes Reiter’s characterization of a rela-tional database in terms of a first order theory, by providing a syntactic char-acterization of a relational space in terms of a multi-context system. This work extends earlier work by Giunchiglia and Ghidini on Local Model Semantics.