Abstract：It is very important to find textual contents satisfying user's demand among a mount of textual contents with location and time tags generated on web. Firstly, location variables and time variables of data objects are normalized, and a three-dimensional Rtree index combining location variables and time variables is designed. Then, a DST-KNN query algorithm and an improved diversity-aware KNN query algorithm called IDST-KNN query algorithm are proposed.Finally, experiments on massive datasets illustrate that the query processing approaches are efficient and accurate.
[1] 孟小峰,丁治明.移动数据管理:概念与技术.北京:清华大学出版社, 2009. (MENG X F, DING Z M. Moving Data Management: Conception and Technology. Beijing, China: Tsinghua University Press, 2009.) [2] 郝忠孝.时空数据库查询与推理.北京:科学出版社, 2010. (HAO Z X. Querying and Inference on Temporal-Spatial Database. Beijing, China: Science Press, 2010.) [3] 周傲英,杨 彬,金澈清,等.基于位置的服务:架构与进展.计算机学报, 2011, 34(7): 1155-1171. (ZHOU A Y, YANG B, JIN C Q, et al. Location-Based Services: Architecture and Progress. Chinese Journal of Computers, 2011, 34(7): 1155-1171.) [4] BUSCH M, GADE K, LARSON B, et al. Earlybird: Real-Time Search at Twitter // Proc of the 28th IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2012: 1360-1365. [5] CHEN C, LI F, OOI B C, et al. TI: An Efficient Indexing Mechanism for Real-Time Search on Tweets[C/OL]. [2016-08-25]. http://www.comp.nus.edu.sg/~ooibc/sigmod11ti.pdf. [6] WU L K, LIN W Q, XIAO X K, et al. LSII: An Indexing Structure for Exact Real-Time Search on Microblogs // Proc of the 29th IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2013: 482-493. [7] YAO J J, XUE Z J, LIU Q Y, et al. Provenance-Based Indexing Support in Micro-blog Platforms // Proc of the 28th IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2012: 558-569. [8] CHEN L S, CONG G, CAO X, et al. Temporal Spatial-Keyword Top-k Publish/Subscribe // Proc of the 31st IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2015: 255-266. [9] CAO X, CONG G, JENSEN C S, et al. Collective Spatial Keyword Querying // Proc of the ACM SIGMOD International Conference on Management of Data. New York, USA: ACM, 2011: 373-384. [10] TUNG A K H, KITSUREGAWA M, MONDAL A, et al. Keyword Search in Spatial Databases: Towards Searching by Document //Proc of the 25th IEEE International Conference on Data Enginee-ring. Washington, USA: IEEE, 2009: 688-699. [11] CAO X, CHEN L S, CONG G, et al. Keyword-Aware Optimal Route Search. Proceedings of the VLDB Endowment, 2012, 5(11): 1136-1147. [12] CHOUDHURY F M, CULPEPPER J S, SELLIS T, et al. Maximizing Bichromatic Reverse Spatial and Textual k Nearest Neighbor Queries. Proceedings of the VLDB Endowment, 2016, 9(6): 456-467. [13] MAGDY A, MOKBEL M F, ELNIKETY S, et al. Mercury: A Memory-Constrained Spatio-Temporal Real-Time Search on Micro-blogs // Proc of the 30th IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2014: 172-183. [14] SKOVSGAARD A, SIDLAUSKAS D, JENSEN C S. Scalable Top-k Spatio-Temporal Term Querying // Proc of the 30th IEEE International Conference on Data Engineering. Washington, USA: IEEE, 2014: 148-159. [15] DROSOU M, PITOURA E. Search Result Diversification. ACM SIGMOD Record, 2010, 39(1): 41-47. [16] QIN L, YU J X, CHANG L. Diversifying Top-K Results[C/OL]. [2016-08-25]. http://vldb.org/pvldb/vol5/p1124_luqin_vldb2012.pdf. [17] CHENG S, ARVANITIS A, CHROBAK M, et al. Multi-Query Diversification in Microblogging Posts[C/OL]. [2016-08/-25]. http://openproceedings.org/2014/conf/edbt/ChengACH14.pdf. [18] CHEN L S, CONG G. Diversity-Aware Top-k Publish/Subscribe for Text Stream // Proc of the ACM SIGMOD International Conference on Management of Data. New York, USA: ACM, 2015: 347-362. [19] THEODORIDIS Y, VAZIRGIANNIS M, SELLIS T. Spatio-Temporal Indexing for Large Multimedia Applications // Proc of the IEEE Conference on Multimedia Computing and Systems. Washington, USA: IEEE, 1996. DOI: 10.1109/MMSC.1996.535011. [20] LAZARIDIS I, PORKAEW K, MEHROTRA S. Dynamic Queries over Mobile Objects // Proc of the 8th International Conference on Extending Database Technology. Berlin, Germany: Springer, 2002: 269-286.
2017, Vol. 30 
