DBridge: A program rewrite tool for set-oriented query execution

We present DBridge, a novel static analysis and program transformation tool to optimize database access. Traditionally, rewrite of queries and programs are done independently, by the database query optimzier and the language compiler respectively, leaving out many optimization opportunities. Our tool aims to bridge this gap by performing holistic transformations, which include both program and query rewrite. Many applications invoke database queries multiple times with different parameter values. Such query invocations made using imperative loops are often the cause of poor performance due to random I/O and round trip delays. In practice, such performance issues are addressed by manually rewriting the application to make it set oriented. Such manual rewriting of programs is often time consuming and error prone. Guravannavar et. al. propose program analysis and transformation techniques for automatically rewriting an application to make it set oriented. DBridge implements these program transformation techniques for Java programs that use JDBC to access database. In this demonstration, we showcase the holistic program/query transformations that DBridge can perform, over a variety of scenarios taken from real-world applications. We then walk through the design of DBridge, which uses the SOOT optimization framework for static analysis. Finally, we demonstrate the performance gains achieved through the transformations.