Despite having many advantages, XML structure imposes several major obstacles to large document processing. Incompatibility between the linear nature of the current algorithms such as caching and prefetch used in operating systems and databases, and the non-linear structure of XML data makes XML processing more costly. Also depth-first (DF) structure of XML documents is a significant overhead to processing applications, including search engines. Recent research on XML query processing has learned that sibling clustering can improve performance significantly. However, the existing ...