一种面向矢量瓦片高效构建的空间索引方法

A Spatial Indexing Method for Efficient Generation of Vector Tiles

针对矢量瓦片在构建过程中对原始矢量数据源检索性能的不足,提出了一种基于改进网格与递归网格排序(sort-tile-recursive,STR)R-树的混合索引结构,用于提升对数据源的空间查询效率。该混合索引通过瓦片金字塔上下文信息改进了一级网格索引的查询方式,减少了查询过程中的空间比较。同时,使用STR R-树作为二级索引,有效减轻了因矢量数据空间分布不均衡所带来的影响,实现了二级查询优化。实验表明,对比数据库常用空间索引(如网格索引、四叉树索引、R-树/R*树索引),该混合索引对不同空间分布的矢量数据适应良好,能显著提高对矢量数据源的查询性能,加速瓦片的构建。

A new structure called hybrid index based on improved grid and STR(sort-tile-recursive) R-Tree is proposed to overcome the shortcomings of vector tiles in the retrieval performance of original vector data sources, to improve the efficiency of spatial queries against data sources.The hybrid index improves the spatial query method of the first-level index through vector tile pyramid context information to reduce the space comparison in the query stage. And at the same time, the index structure proposed can effectively decrease the impact of the unbalanced spatial distribution of vector data and optimize the query performance by using STR R-Tree as secondary index. Experimental results show that, the hybrid index proposed in this paper, compared with other spatial indexes of database, adapts well to different types of spatial data and has obviously better performance in data source query stage of vector tile generation process.