“…They employ tree-like structures, such as R-tree [1,2,17,34,35], Quadtree [3,15], etc., or non-tree structures, such as Grid [5,36], space-filling curve [16,37], etc., to maintain spatial location features. Inverted file [1,5,15,16], Fp-tree [25,38], signature [3,17,18], bitmap [19], etc., are also employed to maintain nonspatial textual features. However, considering a large number of the detailed features of textual features and their many object associations, how to efficiently find and index similar spatial objects from spatial textual big data remains a hot research topic.…”