Keyword Search in XML Streams

Most existing XML stream processing techniques adopt full structured query languages such as XPath or XQuery, which are difficult for ordinary users to learn and use. This chapter presents an XML stream filter system called XKFitler, which uses keyword to filter XML streams. In XKFitler, we use the concepts of XLCA (eXclusive Lowest Common Ancestor) and XLCA Connecting Tree (XLCACT) to define the search semantic and results of keywords, and present an approach to filter XML stream according to keywords. In section 1, the background of keyword search in XML streams is introduced. Section 2 explains the searching results. In section 3, a stack-based keyword searching algorithm for XML stream filtering without schemas is presented in-depth. Section 4 presents a keyword search over XML streams by using schema information. The system architecture of XKFilter is described in section 5. Section 6 is the experiments to show the performance. Section 7 discusses the related work. Section 8 is the summaries of this chapter.