文件名称：Predictive Caching and Prefetching of Query Results in Search Engines
文件大小：226KB
文件格式：PDF
更新时间：2016-07-09 06:04:52
Predictive Caching
We study the caching of query result pages inWeb search en- gines. Popular search engines receive millions of queries per day, and ecient policies for caching query results may en- able them to lower their response time and reduce their hard- ware requirements. We present PDC (probability driven cache), a novel scheme tailored for caching search results, that is based on a probabilistic model of search engine users. We then use a trace of over seven million queries submitted to the search engine AltaVista to evaluate PDC, as well as traditional LRU and SLRU based caching schemes. The trace driven simulations show that PDC outperforms the other policies. We also examine the prefetching of search results, and demonstrate that prefetching can increase cache hit ratios by 50% for large caches, and can double the hit ratios of small caches. When integrating prefetching into PDC, we attain hit ratios of over 0:53.