Due to the complexity of XML query languages, the need for visual query interfaces that can reduce the burden of query formulation is fundamental to the spreading of XML to wider community. We present a RDBMS-based XML query evaluation system, called XBLEND, that takes a novel and nontraditional approach to improving query performance by blending visual query formulation and query processing. It exploits the latency offered by GUI-based visual query formulation to prefetch portions of the query results. The basic idea is that we prefetch constituent path expressions, store the synopsis of intermediary results, reuse them when connective is added or "Run" is pressed. In our demonstration we show that our system exhibits promising performance in evaluating XML queries and show its usefulness in life sciences domain.
Zhou Yong, Sourav S. Bhowmick, Erwin Leonardi, Kla