The Community for Technology Leaders
Green Image
Issue No. 05 - September/October (2000 vol. 12)
ISSN: 1041-4347
pp: 694-714
<p><b>Abstract</b>—Traditionally, the answer to a database query is construed as the set of all tuples that meet the criteria stated. Strict adherence to this notion in query evaluation is, however, increasingly unsatisfactory because decision makers are more prone to adopting an exploratory strategy for information search which we call “getting some answers quickly, and perhaps more later.” From a decision-maker's perspective, such a strategy is optimal for coping with information overload and makes economic sense (when used in conjunction with a micropayment mechanism). These new requirements present new opportunities for database query optimization. In this paper, we propose a progressive query processing strategy that exploits this behavior to conserve system resources and to minimize query response time and user waiting time. This is accomplished by the heuristic decomposition of user queries into subqueries that can be evaluated on demand. To illustrate the practicality of the proposed methods, we describe the architecture of a prototype system that provides a nonintrusive implementation of our approach. Finally, we present experimental results obtained from an empirical study conducted using an Oracle Server that demonstrate the benefits of the progressive query processing strategy.</p>
WWW, Internet, progressive query evaluation, query optimization, query rewrite.

C. H. Goh, B. C. Ooi and K. Tan, "Query Rewriting for SWIFT (First) Answers," in IEEE Transactions on Knowledge & Data Engineering, vol. 12, no. , pp. 694-714, 2000.
93 ms
(Ver 3.3 (11022016))