基于尺度选择性的空间数据源选择与预取策略

合理高效的数据源选择策略是提高空间信息检索系统效率的重要因素之一。针对以往研究中对空间尺度语义关注程度的不足,提出一种结合空间尺度语义选择检索数据源的方法。该方法综合考虑人眼视觉特性,计算出参与分布式查询计划生成的数据源集合,过滤在尺度意义上对最终查询结果无影响的数据源,并通过将数据源的简化表达进行预取,进一步减少了查询的整体执行代价。实验结果表明,提出的方法在大尺度查询和小尺度查询时均具有良好的性能。

Geospatial Data Sources Selection and Prefetching Strategy Based on Scale Selectivity

Effective data source selection strategy is one of the important issues of the spatial information retrieval. This paper proposes a method to select data source based on spatial scale semantics. The method determines the data source set for the distributed query plan fully considering the human vision features, filters those data sources which don't contribute to the final result. Through prefetching the simplified representation of data sources, the method can further reduce the overall cost of a query. The experiment shows that the proposed method has favorable performance both in small and large size query.