Exploit Sequencing to Accelerate XML Twig Query Answering

  • Qian Qian
  • Jianhua Feng
  • Jianyong Wang
  • Lizhu Zhou
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3882)


Speeding up query evaluation in large XML repositories becomes a challenging and all-important problem with vast XML-related applications arising. In this paper, we present SCALER, an efficient algorithm for XML query answering based on UDFTS and effective twig structure matching scheme. UDFTS not only constructs a one-to-one correspondence between trees and sequences but also maintains critical parent-child relationships for twig structure matching. With SCALER, XML queries can be performed by subsequence matching without breaking twigs into sub paths and evaluating these paths individually. Thus, costly join operations can be avoided elegantly. We also show the correctness of query answering by eliminating false dismissals and false alarms naturally in SCALER. By a thorough experimental study on various real-life data, we prove the efficiency and scalability of SCALER over the previous known alternative.


Query Answer Query Answering Valid Subsequence Twig Pattern Twig Query 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Qian Qian
    • 1
  • Jianhua Feng
    • 1
  • Jianyong Wang
    • 1
  • Lizhu Zhou
    • 1
  1. 1.Deptartment of Computer Science and TechnologyTsinghua UniversityBeijingP.R. China

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