RIPPNET: Efficient Range Indexing in Peer-to-Peer Networks

Write-heavy applications present a challenge to peer-to-peer indexing methods which need to update the index for each write operation. The costs incurred when the distributed index is updated becomes a bottleneck. Current distributed indexing methods are designed for indexing and retrieving single tuples, giving a very high update cost. In this paper we present a new approach to efficient peer-topeer range indexing that employs indexing of ranges to reduce average update costs as well as providing efficient data localization and decoupling from data placement policies. Based on results from experiments, we demonstrate the applicability and significantly reduced update cost of the new approach

Robust Aggregation in Peer-to-Peer Database Systems

Peer-to-peer database systems (P2PDBs) aim at providing database services with node autonomy, high availability and loose coupling between participating nodes by building the DBMS on top of a peer-to-peer network. A key feature of current peer-to-peer systems is resilience to churn in the overlay network layer. A major challenge in P2PDBs is to provide similar robustness in the data and query processing layer. In this paper we in particular describe how aggregation queries in P2PDBs can be handled in order to reduce the impact of churn on accuracy of results. We perform a formal study of data loss and accuracy of such queries, and describe new approaches that increase the accuracy of aggregation queries in P2PDBs under churn