... of PDMS Indexes (either local index or distributed index) are built to facilitate query processing A MetaStore is created to maintain the information of schema mapping, indexing and data distribution ... 2 Query Processing in Peer- to -Peer Based Data Management System Sai Wu School of Computing National University of Singapore Summary In last ten years, we have witnessed the success of P2P (Peer- to -Peer) ... used TPC-H queries and dataset in our benchmark Keywords: P2P, PDMS, BATON, Just -in- time, Indexing, Adaptive Query Processing, Approximate Query Processing, Sampling, Online Aggregation ii Acknowledgments...