Compile-time inter-query dependence analysis

Most parallel databases exploit two types of parallelism: intra-query parallelism and inter-transaction concurrency. Between these two cases lies another type of parallelism: inter-query parallelism within a transaction or application. Exploiting inter-query parallelism requires either compiler support to automatically parallelize the existing embedded query programs, or programming support to write explicitly parallel query programs. In this paper, we present compiler analysis to automatically detect parallelism in the embedded query programs. We present compiler algorithms for detecting dependences in such programs. We show that the properties of some aggregate functions such as MIN and MAX can help reduce statically computed dependences.