Compile-time inter-query dependence analysis

Abstract

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. The authors present compiler analysis to automatically detect parallelism in the embedded query programs. They present compiler algorithms for detecting dependences in such programs. They show that the properties of some aggregate functions such as MIN and MAX can help reduce statically computed dependences.