摘要： 在Web环境下查询遥感图像数据时,由于数据规模巨大和数据来源众多,常出现页面响应时间过长甚至没有响应的情况。针对传统分页查询方法查询数据量越大,页面响应速度越慢的问题,提出一种基于页面转换算法的多源海量遥感数据分页查询优化策略。调用Web服务获取各个数据源中满足条件的记录总数,利用页面转换算法实现用户查询页面的划分,由智能Agent动态查询与合并各个数据源的子页面。对不同的查询数据量进行实验,结果表明,传统分页查询方法的响应时间随着数据量的增加呈线性增长趋势,而优化后分页查询方法的响应时间基本保持不变。
关键词:
海量,
多源,
分页查询,
页面转换,
Web服务,
智能Agent,
遥感
Abstract: When querying remote sensing images under the Web environment,it often takes too long to wait for the page response due to the mass data volumes and numerous data sources.The page response time of the traditional paging query methods increases rapidly when the query volumes become larger and larger.An optimization strategy based on the new page transformation algorithm for the paging query of multi-source and mass remote sensing data is proposed.The total number of records that satisfy the query criteria is acquired by invoking Web services.The page requested by users is divided into several subpages using the page transformation algorithm.The subpage for each data source is queried dynamically and merged by the intelligent Agent.Some experiments are performed for different data volume of queries.Experimental results show that as data volumes increase,the response time of the traditional query methods increases linearly,while the response time of the optimized paging query method remains unchanged as a whole.
Key words:
mass,
multi-source,
paging query,
page transformation,
Web service,
intelligent Agent,
remote sensing
中图分类号: