Efficient evaluation of multiple queries on streaming XML data

Abstract

Traditionally, XML documents are processed at where they are stored. This allows the query processor to exploit pre-computed data structures (e.g., index) to retrieve the desired data efficiently. However, this mode of processing is not suitable for many applications where the documents are frequently updated. In such situations, efficient evaluation of multiple queries over streaming XML documents becomes important. This paper introduces a new operator, mqX-scan, which efficiently evaluates multiple queries with a single pass on streaming XML data. To facilitate matching, mqX-scan utilizes templates containing paths that have been traversed to match regular path expression patterns in a pool of queries. Results of the experiments demonstrate the efficiency and scalability of the mqX-scan operator.