Efficient XML Query Processing in RDBMS Using GUI-Driven Prefetching in a Single-User Environment

In this paper, we address the problem of efficient processing of XQueries in single-user relational environment where the queries are formulated using a user-friendly GUI. We take a novel and non-traditional approach to improving query performance by prefetching data during the formulation of a query. The latency offered by GUI-based query formulation is utilized to prefetch portions of the query results. To realize this, we present an algorithm for prefetching based on data synopses statistics and GUI actions during visual query formulation. Experimental evaluation indicates that prefetching is viable as the combined time taken by all the prefetching operations is not significantly more than normal query execution time. Our experiments in the context of biological data show that prefetching improves the query response time by 7-96% with a greater improvement for larger data sets. Also, we show the impact of errors committed by users during query formulation on the query performance.