AQR-Toolkit: An Adaptive Query Routing Middleware for Distributed Data Intensive Systems Ling Liu, Calton Pu, David Buttler, Wei Han, Henrique Paques, and Wei Tang   View Paper (PDF)     View Demo (HTML)   Return to Demonstrations Abstract Query routing is an intelligent service that can direct query requests to appropriate servers that are capable of answering the queries. The goal of a query routing system is to provide efficient associative access to a large, heterogeneous, distributed collection of information providers by routing a user query to the most relevant information sources that can provide the best answer. Effective query routing not only minimizes the query response time and the overall processing cost, but also eliminates a lot of unnecessary communication overhead over the global networks and over the individual information sources. The AQR-Toolkit divides the query routing task into two cooperating processes: query refinement and source selection. It is well known that a broadly defined query inevitably produces many false positives. Query refinement provides mechanisms to help the user formulate queries that will return more useful results and that can be processed efficiently. As a complimentary process, source selection reduces false negatives by identifying and locating a set of relevant information providers from a large collection of available sources. By pruning irrelevant information sources, source selection also reduces the overhead of contacting the information servers that do not contribute to the answer of the query. The system architecture of AQR-Toolkit consists of a hierarchical network (a directed acyclic graph) with external information providers at the leaves and query routers as mediating nodes. The end-point information providers support query-based access to their documents. At a query router node, a user may browse and query the meta information about information providers registered at that query router or make use of the router's facilitates for query refinement and source selection. BIBTEX @inproceedings{DBLP:conf/sigmod/LiuPBHPT00,   author    = {Ling Liu and                 Calton Pu and                 David Buttler and                 Wei Han and                 Henrique Paques and                 Wei Tang},    editor    = {Weidong Chen and                 Jeffrey F. Naughton and                 Philip A. Bernstein},    title     = {AQR-Toolkit: An Adaptive Query Routing Middleware for Distributed                 Data Intensive Systems},    booktitle = {Proceedings of the 2000 ACM SIGMOD International Conference on                 Management of Data, May 16-18, 2000, Dallas, Texas, USA},    journal   = {SIGMOD Record},    publisher = {ACM},    volume    = {29},    number    = {2},    year      = {2000},    isbn      = {1-58113-218-2},    pages     = {597},    crossref  = {DBLP:conf/sigmod/2000},    bibsource = {DBLP, http://dblp.uni-trier.de} } }, DiSC'01 Copyright ©2002 ACM Inc.