Every Click You Make, IWill Be Fetching It: Efficient XML Query Processing in RDMS Using GUI-driven Prefetching

formulation and efficient processing of the formulated query. However, due to the nature of XML data, formulating an XML query using an XML query language such as XQuery requires considerable effort. A user must be completely familiar with the syntax of the query language, and must be able to express his/her needs accurately in a syntactically correct form. In many real life applications it is not realistic to assume that users are proficient in expressing such textual queries. Hence, there is a need for a user-friendly visual querying schemes to replace data retrieval aspects of XQuery. In this paper, we address the problem of efficient processing of XQueries in the 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 in a single-user environment. The latency offered by the GUI-based query formulation is utilized to prefetch portions of the query results. The basic idea we employ for prefetching is that we prefetch constituent path expressions, store the intermediary results, reuse them when connective is added or "Run" is pressed.