PRoBe: Multi-dimensional Range Queries in P2P Networks

Structured P2P systems are effective for exact key searches in a distributed environment as they offer scalability, self-organization, and dynamicity. These valuable properties also make them a candidate for more complex queries, such as range queries. In this paper, we describe PRoBe, a system that supports range queries over multiple attributes in P2P networks. PRoBe uses a multi-dimensional logical space for this purpose and maps data items onto this space based on their attribute values. The logical space is divided into hyper-rectangles, each maintained by a peer in the system. The range queries correspond to hyper-rectangles which are answered by forwarding the query to the peers responsible for overlapping regions of the logical space. We also propose load balancing techniques and show how cached query answers can be utilized for the efficient evaluation of similar range queries. The performance of PRoBe and the effects of various parameters are analyzed through a simulation study.