An Efficient Multi-Query Evaluation Technique for Streaming XML Data

Recently, there has been growing interest in streaming XML data. Much of the work on streaming XML data has been focused on efficient filtering of XML data. Such XML filtering systems deliver XML documents to interested users. The burden of extracting the XML fragments of interest from XML documents is placed on users. As a result, several evaluation techniques for streaming XML data, which only extract interested XML fragments by directly evaluating XML queries on streaming XML data, have been proposed. However, existing evaluation techniques for streaming XML data only support the restricted subset of XPath queries, and multiple queries cannot be evaluated by such evaluation techniques. In this paper, we propose XTREAM which evaluates multiple queries in conjunction with the read-once nature of streaming data. In contrast to the previous work, XTREAM supports a wide class of XPath queries including order based predicates and so on. Experimental results with real-life and synthetic XML data demonstrate the efficiency and scalability of XTREAM.