Space keyword query method and device based on geohash and Patricia Trie

Abstract

The invention relates to a space keyword query method and device based on geohash and Patricia Trie. The method comprises a data preprocessing step of encoding all position points in a data set D intoa character string geoStr with the length of n through a geohash spatial coding method and sorting and generating numbers id for each row of data in the data set D by a lexicographic order with geoStr as a sorting object, a space keyword index establishment step of constructing Patricia Trie for geoStr and obtaining a space keyword index structure, wherein a leaf node of Patricia Trie points at an inverted index constructed according to a keyword in a domain, a list element the inverted index is a keyword and a corresponding id list, and the domain refers to a character string formed from a root node to the leaf node, a space keyword query step of retrieving a space keyword index structure, obtaining an id satisfying a query condition, obtaining an id candidate set through filtering, verifying the candidate set and returning a position point satisfying a space query condition. According to the method and the device, the keyword query in any space range can be efficiently supported.

Description

technical field [0001] The invention relates to a spatial keyword query method and device based on geohash and Patricia Trie, belonging to the field of spatial keyword query (Spatial Keyword query), location-based service (Location-Based Service, LBS) and other fields. Background technique [0002] In recent years, with the popularization of GPS mobile devices and the development of social networks, a large number of location-based services have emerged, such as: social services (WeChat, Momo, Twitter, Foursquare, etc.), food and housing services (Ctrip, Qunar, Met Group takeaway, etc.), navigation services (Gaode Map, Tencent Map, Google Map, etc.), entertainment services (City Hot Fight, Wikitude, etc.). These services generate a large amount of data with location attributes, that is, spatial text. How to quickly obtain the required information from these data is the core issue in the field of spatial text query. According to application scenarios, spatial text query can ...

AI Technical Summary

Problems solved by technology

The variant of R-Tree optimizes R-Tree based on the principles of minimum area, minimum overlapping area, minimum perimeter and high storage utilization, but the retrieval efficiency is still restricted by the multi-path query problem of R-Tree.

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