POSITION TOP-K KEYWORD QUERY-BASED FAST INDEXING METHOD AND SYSTEM UNDER SLIDING WINDOW

摘要

Disclosed are a position top-k keyword query-based fast indexing method and system under a sliding window. The fast indexing method comprises constructing a data indexing model and query. The construction of the data indexing model comprises the following: determining a geographical range covered by a quadtree and a node splitting rule; accepting a data stream, and inserting data into a node; for node splitting which satisfies the node splitting rule, inserting data to generate a complete quadtree; for a leaf node, storing an inverted index; for a non-leaf node, storing an MG aggregation abstract of sub-nodes thereof; and adjusting the structure of the quadtree. The query comprises the following: initializing a set of results; carrying out a branch trim operation to obtain a set of candidate results; and taking a word having the maximum score from a priority queue to start computation, traversing starting from a root node until an accurate score thereof is found in a leaf node and placing same into a queue, and repeating until the first k words in the priority queue no longer change. The present invention can effectively reduce costs and improve the speed of querying, can also effectively trim a search space according to word frequency and position proximity, and can process geographical text data streams with a high arrival rate.