Abstract
In this paper we introduce data sharing settings for peer data sharing systems. In a peer data sharing system, databases in peers are created independently and may have semantic inter-dependencies between peers with regards to data. Each peer specifies pair-wise data sharing settings/mappings with neighboringpeers for sharing and exchanging related data. The mappings express how data in one peer relates to data in another peer. We also introduce a model of peer data sharing systems taking into account of the data sharing settings and present some algorithmic problems that need to be solved.