Lazy XML Updates: Laziness as a Virtue of Update and Structural Join Efficiency

XML documents are normally stored as plain text files. Hence, the natural and most convenient way to update XML documents is to simply edit the text files. But efficient query evaluation algorithms require XML documents to be indexed. Every element is given a unique identifier based on its location in the document or its preorder-traversal order, and this identifier is later used as (part of) the key in the index. Reassigning orders of possibly a large number of elements is therefore necessary when the original XML documents are updated. Immutable dynamic labeling schemes have been proposed to solve this problem, that, however, require very long labels and may decrease query performance. If we consider a real-world scenario, we note that many relatively small ad-hoc XML segments are inserted/deleted into/from an existing XML database. In this paper, we start from this consideration and we propose a new lazy approach to handle XML updates that also improves query performance. The lazy ...

• Type: Conference
• Year: 2005
• Where: SIGMOD
• Authors: Barbara Catania, Wen Qiang Wang, Beng Chin Ooi, Xiaoling Wang
• Keywords: Ad-hoc Xml Segments, Algorithms Require Xml, Database, SIGMOD 2005, XML Documents