creators_name: Gan, Qingqing creators_name: Suel, Torsten type: conference_item datestamp: 2009-04-06 19:09:40 lastmod: 2009-05-11 11:13:07 metadata_visibility: show title: Improved Techniques for Result Caching in Web Search Engines ispublished: pub full_text_status: public pres_type: paper abstract: Query processing is a major cost factor in operating large web search engines. In this paper, we study query result caching, one of the main techniques used to optimize query processing performance. Our first contribution is a study of result caching as a weighted caching problem. Most previous work has focused on optimizing cache hit ratios, but given that processing costs of queries can vary very significantly we argue that total cost savings also need to be considered. We describe and evaluate several algorithms for weighted result caching, and study the impact of Zipf-based query distributions on result caching. Our second and main contribution is a new set of feature-based cache eviction policies that achieve significant improvements over all previous methods, substantially narrowing the existing performance gap to the theoretically optimal (clairvoyant) method. Finally, using the same approach, we also obtain performance gains for the related problem of inverted list caching. date: 2009-04 pagerange: 431-431 event_title: 18th International World Wide Web Conference event_location: Madrid, Spain event_dates: April 20th-24th, 2009 event_type: conference refereed: TRUE citation: Gan, Qingqing and Suel, Torsten (2009) Improved Techniques for Result Caching in Web Search Engines. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain. document_url: http://www2009.eprints.org/44/1/p431.pdf document_url: http://www2009.eprints.org/44/2/cache-www.ppt