XML資料分群之查詢處理設計

Abstract

―XML 資料的查詢處理，已經是重要的研究議 題，而針對分群運算的處理，目前也受到大家的重視。先 前研究所提出的作法，必需要輸入整份 XML 文件。而本 論文提出的處理方式，則設計內容索引，快速地將元素分 群，再利用主實體索引，將該群的資料取出。實驗結果顯 示，當分群或輸出的運算式數量較少時，我們的系統會比 先前的研究所提出的方法有著更佳的效率。XML query processing has become an important research issue, and many researches now focus on the functionality of group-by expressions. Previous researches need to process the entire XML document. We propose a new method in this paper based on indices. The value index is designed to efficiently identify the group of each element, and the master-entity index is designed to efficiently retrieve the required data for a particular group. We have performed a series of experiments, and the results show that the proposed method is more efficient than the existing ones when the grouping or return expressions are few.