Query processing in very large XML databases

The Extensible Markup Language (XML) model has recently gained huge popularity because of its ability to represent a wide variety of structured and semi-structured data. Several query languages have been proposed for the XML data model, the most-widely known is XQuery. Traditional XML query processing research has concentrated on the intra-document data retrieval and the structures in their support. In this paper, we review these algorithms and structures and show their superiority when processing independent XML documents. However, the direct application of these algorithms to process queries against interlinked XML documents are shown to generate incorrect results. New, extended version of these algorithms and structures are introduced and shown to perform correctly in processing both independent and inter-linked XML documents