Approximating Aggregation Queries in Peer-to-Peer Networks

Peer-to-peer databases are becoming prevalent on the Internet for distribution and sharing of documents, applications, and other digital media. The problem of answering large scale, ad-hoc analysis queries ? e.g., aggregation queries ? on these databases poses unique challenges. Exact solutions can be time consuming and difficult to implement given the distributed and dynamic nature of peer-to-peer databases. In this paper we present novel sampling-based techniques for approximate answering of ad-hoc aggregation queries in such databases. Computing a high-quality random sample of the database efficiently in the P2P environment is complicated due to several factors ? the data is distributed (usually in uneven quantities) across many peers, within each peer the data is often highly correlated, and moreover, even collecting a random sample of the peers is difficult to accomplish. To counter these problems, we have developed an adaptive two-phase sampling approach, based on random walks o...

• Type: Conference
• Year: 2006
• Where: ICDE
• Authors: Benjamin Arai, Gautam Das, Dimitrios Gunopulos, Vana Kalogeraki
• Keywords: Ad-hoc Aggregation Queries, Ad-hoc Analysis Queries, Database, ICDE 2006, Peer-to-peer Databases