测绘学报

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网络地理信息服务中的空间数据缓存算法研究

喻占武, 王浩,曾武, 潘少明   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2011-12-28 发布日期:2019-01-01

Spatial Data Cache in Network Geographic Information Service

YU Zhan-wu, WANG Hao, ZENG Wu, PAN Shao-ming   

  • Received:1900-01-01 Revised:1900-01-01 Online:2011-12-28 Published:2019-01-01

Abstract: A cache mechanism for terrain data and image data is proposed in Network Geographic Information Service (NGIS). Based on the cache granularity of tile, the tile cache index is designed and proved to be efficient. Tile Access Interval time Longest (TAIL) cache replacement algorithm and its fast operation method are presented. The image data set of LANDSET7 with 30 meter resolution and the terrain data set of SRTM with 90 resolution are used in trace-driven simulations of TAIL. The results show that, in TAIL cache, the cache hit rate and byte hit rate are improved, the response time of tile requests and the number of tile requests processed by NGIS server are reduced significantly.