AmbientDB : relational query processing in a P2P network

A new generation of applications running on a network of nodes, that share data on an ad-hoc basis, will benefit from data management services including powerful querying facilities. In this paper, we introduce the goals, assumptions and architecture of AmbientDB, a new peer-to-peer (P2P) DBMS prototype developed at CWI. Our focus is on the query processing facilities of AmbientDB, that are based on a tree-level translation of a global query algebra into multi-wave stream processing plans, distributed over an ad-hoc P2P network. We illustrate the usefulness of our system by outlining how it eases construction of a music player that generates intelligent playlists with collaborative filtering over distributed music logs. Finally, we show how the use of a Distributed Hash Tables (DHT) at the basis of AmbientDB to provide global indexing support allows applications like the P2P music player to scale to large amounts of nodes.