Ctree: a compact tree for indexing XML data

In this paper, we propose a novel compact tree (Ctree) for XML indexing, which provides not only concise path summaries at the group level but also detailed child-parent links at the element level. Group level mapping allows efficient pruning of a large search space while element level mapping provides fast access to the parent of an element. Due to the tree nature of XML data and queries, such fast child-to-parent access is essential for efficient XML query processing. Using group-based element reference, Ctree enables the clustering of inverted lists according to groups, which provides efficient join between inverted lists and structural index group extents. Our experiments reveal that Ctree is efficient for processing both single-path and branching queries with various value predicates. Categories and Subject Descriptors E.1 [Data Structures]: trees General Terms Algorithms, Measurement, Performance, Experimentation Keywords XML index, path summary, XQuery evaluation, value index, ...

• Type: Conference
• Year: 2004
• Where: WIDM
• Authors: Qinghua Zou, Shaorong Liu, Wesley W. Chu
• Keywords: Efficient XML Query, Element Level, Group Level, WIDM 2004