计算机科学 ›› 2025, Vol. 52 ›› Issue (8): 136-145.doi: 10.11896/jsjkx.240600075
缪祝青1, 韩京宇1,2, 李彩云1, 王彦之1, 毛毅1, 张怡婷1
MIAO Zhuqing1, HAN Jingyu1,2, LI Caiyun1, WANG Yanzhi1, MAO Yi1, ZHANG Yiting1
摘要: 近年来,基于位置服务的技术迅猛发展,产生了海量的路网轨迹数据。而路径范围查询作为一种路网轨迹查询类型,是支持其他查询类型的基础。为了实现对海量路网轨迹数据的高效索引,同时提供精确的路径范围查询服务,提出了一种基于道格拉斯-普克算法的学习型索引结构(Douglas-Peuker Based Learned Index Structure,DPLI)。首先将轨迹数据分为多个轨迹段,然后取轨迹段中的点作为轨迹数据的表征,利用映射函数将其映射为一维映射值序列,而后根据键值数量将其划分为多个数据分片。在分片内将首尾数据组成一条线段,然后计算其余数据点距离线段的拟合误差,将超过误差阈值的数据点作为新的线段端点,递归分割原有的直线段,直到所有数据点的拟合误差小于阈值,从而拟合分段线性函数。采用多个路网数据和轨迹数据进行了充分的实验,实验结果表明:与传统索引方法相比,DPLI具有更快的构建效率和磁盘访问效率;与学习索引方法相比,DPLI保持了构建效率的优势,并且达到了100%查询召回率。
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