Parallel Structural Join Algorithm on Shared-Memory Multi-Core Systems

The leap from single-core to multi-core has permanently altered the course of computing, enabling increased productivity, powerful energy-efficient performance, and leading-edge advanced computing experiences. Although traditional single-thread XPath query evaluation algorithms can run properly on multi-core CPUs, they cannot take full use of the computing resources of multi-core CPUs. To take advantage of multi-core, efficient parallel algorithms are fairly desirable to evaluate XPath in parallel. In this paper, we present, PSJ, an efficient Parallel Structural Join algorithm for evaluating XPath. PSJ can skip many ancestor or descendant elements by evenly and efficiently partitioning the input element lists into some buckets. PSJ obtains high performance by evaluating XPath step in each bucket in parallel. It is very efficient to partition the input lists and is effective to evaluate XPath step in buckets, and therefore PSJ achieves a high speedup ratio. We have implemented our proposed algorithm and the experimental results show that PSJ algorithm achieves high performance and outperforms the existing state-of-the-art methods significantly.