Querying a super-peer in a schema-based super-peer network*

We propose a novel approach for defining and querying a super-peer within a schema-based super-peer network organized into a two-level architecture: the low level, called the peer level (which contains a mediator node), the second one, called super-peer level (which integrates mediators peers with similar content). We focus on a single super-peer and propose a method to define and solve a query, fully implemented in the SEWASIE project prototype. The problem we faced is relevant as a super-peer is a two-level data integrated system, then we are going beyond traditional setting in data integration. We have two different levels of Global as View mappings: the first mapping is at the super-peer level and maps several Global Virtual Views (GVVs) of peers into the GVV of the super-peer; the second mapping is within a peer and maps the data sources into the GVV of the peer. Moreover, we propose an approach where the integration designer, supported by a graphical interface, can implicitly define mappings by using Resolution Functions to solve data conflicts, and the Full Disjunction operator that has been recognized as providing a natural semantics for data merging queries.