公开(公告)号：US11176112B1

公开(公告)日：2021-11-16

申请号：US17084847

申请日：2020-10-30

申请人： National Central University

发明人： Chih-Yuan Huang ,  Yu-Jui Chang

IPC分类号： G06F16/22 ,  G06F16/28 ,  G06F16/248 ,  G06F16/21 ,  G06F16/2453 ,  G06F11/34

摘要： An apparatus of adaptive index structures is provided. Four common data attributes, including time, space, keyword, and value, are used. The present invention is a structure adaptively selecting the most efficient combined index by estimating index performance and selectivity rate. The main concept is to set indexes with high selectivity rates at positions having higher priorities for processing query. The intermediate result of query is minimized and the performance is further improved. The present invention uses multiple indexes, where all possible combined-index orders are considered and the best combined index is selected according to different query adaptabilities. As a result, the structure has a high chance of saving query time at a rate of more than 25 times as compared to a structure with indexes of a single attribute sequence. Furthermore, as compared to the traditional relational database PostGIS, the reaction time is also twice faster.