Research on why-not questions of top-K query in orthogonal region

摘要

Orthogonal region query has always been an important topic in the field of database query, geographic information system, computer graphics, data mining and multimedia information retrieval. In recent years, the "Why-Not" questions has gradually become a hot topic in the SQL query, Skyline query, and spatial keyword Top-K query. However, no one has answered the "Why-Not" questions of the orthogonal region Top-K query. Based on the in-depth study of the orthogonal region Top-K query algorithm, this paper first proposes to answer the "Why-Not" questions in the orthogonal region Top-K query. We adjust the initial query so that the result set of the new query contains the "Why-Not" elements with the least cost. Abundant experiments have been conducted to analyze the proposed algorithm on the factors of initial k value, initial rank, and data size. The experimental results demonstrate the accuracy and efficiency of the proposed algorithm.