The Joy of SAX

Most current XQuery implementations require that all XML data reside in memory in one form or another before they start processing the data. This is unacceptable for large XML documents. The only event-based techniques that do not require the materialization of all data in memory are based on transducers. Transducers use SAX events to evaluate XPath queries using finite state machines. SAX allows parsing and processing of XML documents in a stream fashion, but is hard to use even for simple tasks since it leaves the burden to the programmer to maintain and propagate the state between events. As is well known to people who have written non-trivial SAX event handlers, SAX can be used effectively under a disciplined use of pipes made out of SAX event handlers, where a producer object sends SAX events to a consumer object, which in turn becomes the producer for the next consumer, etc, thus forming a pipe. In this paper, I present an event-based XQuery interpreter, called XStreamQuery, b...

• Type: Conference
• Year: 2004
• Where: XIMEP
• Authors: Leonidas Fegaras
• Keywords: SAX Allows Parsing, SAX Event Handlers, Sax Events, XIMEP 2004