Interprocedural query extraction for transparent persistence

Transparent persistence promises to integrate programming languages and databases by allowing programs to access persistent data with the same ease as non-persistent data. In this work we demonstrate the feasibility of optimizing transparently persistent programs by extracting queries to efficiently prefetch required data. A static analysis derives query structure and conditions across methods that access persistent data. Using the static analysis, our system transforms the program to execute explicit queries. The transformed program composes queries across methods to handle method calls that return persistent data. We extend an existing Java compiler to implement the static analysis and program transformation, handling recursion and parameterized queries. We evaluate the effectiveness of query extraction on the OO7 and TORPEDO benchmarks. This work is focused on programs written in the current version of Java, without languages changes. However, the techniques developed here may also be of value in conjunction with object-oriented languages extended with high-level query syntax.