YFilter: Efficient and scalable filtering of XML documents

Soon, much of the data exchanged over the Internet will be encoded in XML, allowing for sophisticated filtering and content-based routing. We have built a filtering engine called YFilter, which filters streaming XML documents according to XQuery or XPath queries that involve both path expressions and predicates. Unlike previous work, YFilter uses a novel NFA-based execution model. In this demonstration, we present the structures and algorithms underlying YFilter, and show its efficiency and scalability under various workloads.