High-bandwidth memory (HBM) gives an additional opportunity for hardware performance benefits. The high available bandwidth compared to regular DRAM allows execution of many threads in parallel, avoiding memory stalls through many concurrent memory accesses This is especially interesting considering database join algorithms optimized for multicore CPUs, even more when running on a manycore processor like a Xeon Phi Knights Landing (KNL). The drawback of HBM, however, is its small capacity as well as under-utilization in random memory access patterns. In this paper, we analyze the impact of HBM on join processing on the KNL architecture. We evaluate main memory hash join and sort-merge join algorithms of relational DBMS as well as data stream joins, comparing execution times in different HBM configurations. Our results show performance gains up to 3\(\times \) for joins when HBM is used. Finally, we summarize our lessons learned, give additional advice for HBM utilization, and discuss generalizations for other levels of the memory hierarchy.

中文翻译：

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加入高带宽内存：内存层次结构中的新级别

高带宽内存（HBM）为硬件性能带来了额外的机会。与常规DRAM相比，高可用带宽允许并行执行许多线程，从而避免由于并发访问而造成的内存停顿。考虑到针对多核CPU优化的数据库联接算法，尤其是在诸如至强Phi Knights等多核处理器上运行时，这尤其有趣。着陆（KNL）。但是，HBM的缺点是它的容量小以及在随机存储器访问模式中的利用率不足。在本文中，我们分析了HBM对KNL架构上的联接处理的影响。我们评估了关系DBMS的主内存散列连接和排序合并连接算法以及数据流连接，比较了不同HBM配置中的执行时间。我们的结果表明，性能提升高达3\（\ times \）用于使用HBM的联接。最后，我们总结总结的经验教训，为HBM的使用提供其他建议，并讨论内存层次结构其他级别的概括。