Keyword Search on Streaming XML Fragments

With the growing popularity of XML and emergence of streaming data model, processing streaming XML has become an important topic. This paper proposes keyword search solution over XML fragment streams based on hole-filler model. Two efficient indexes, dual list and sketch are developed to further improve the performance: dual list indexes the candidate XML fragments to keep track of the relationship among fragments that include keywords and sketch summarizes the candidate XML elements to compute SLCA. SLCA computing algorithm, which is triggered by certain keywords, avoids redundant operations on computing the SLCA of elements that not contribute to the final result. The algorithm produces partial answers continuously without having to wait for the end of the stream. We illustrate the effectiveness of the algorithms developed with experiments.