Expressive query translation in peer databases

Title: Expressive query translation in peer databases
Authors: Masud, Md. Mehedi
Date: 2005
Abstract: Query processing in peer database systems has moved towards a new direction beyond mere file sharing and keyword-based information retrieval processes used in the first peer-to-peer systems to embrace data sharing and coordination across heterogeneous frontiers. The strong dynamics of peer-to-peer networks, coupled with the diversity of peer vocabularies, makes query processing in peer database systems a very challenging task. In this thesis, we propose a framework for translating expressive relational queries across heterogeneous peer databases. Our framework avoids an integrated global schema or centralized structures common to the involved peers. The cornerstone of the approach is the use of both syntax and instance level mappings that each peer constructs and shares with other peers. Based on this user provided mapping information, the algorithm applies generic translation rules to translate SQL queries. Our approach supports both query translation and propagation among the peers preserving the autonomy of individual peers. It combines two previous proposals for data sharing via query mapping across heterogeneous boundaries that were based on syntax and instance level mappings separately into a more general framework. We have developed a prototype as a query service layer wrapped around a basic service providing heterogeneity management. The prototype has been evaluated on a small peer-to-peer network to demonstrate the viability of the approach.
CollectionTh├Ęses, 1910 - 2010 // Theses, 1910 - 2010
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