Generalized Inter-Cloud Structured Data Sharing

In this paper, we discuss the issue of collaborative data sharing among a number of parties to provide rich online services to their clients. We assume that each party hosts its data in a private cloud infrastructure but they collectively agree to certain well-defined set of accesses and access restrictions to one another's databases. We show how these can be used to derive access rules that become the basis of access control and query planning. In this paper we focus entirely on relational database sharing, and present efficient and near optimal heuristic algorithms for access rule derivation and query planning in spite of the NP-hardness and high complexity of the underlying problems.