A spectrum of new hardware has been studied to accelerate database systems in the past decade. Specifically, CUDA cores are known to benefit from the fast development of GPUs and make notable performance improvements. The state-of-the-art GPU-based implementation, i.e., Crystal, can achieve up to 61 times higher performance than CPU-based implementations. However, experiments show that the approach has already saturated almost all GPU memory bandwidth, which means there is little room left for further performance improvements. We introduce RTCUDB, the first query engine that leverages ray tracing (RT) cores in GPUs to accelerate database query processing. RTCUDB efficiently transforms the evaluation of a query into a ray-tracing job in a three-dimensional space. By dramatically reducing the amount of accessed data and optimizing the data access pattern with the ray tracing mechanism, the performance of RTCUDB is no longer limited by the memory bandwidth as in CUDA-based implementations. Experimental results show that RTCUDB outperforms the state-of-the-art GPU-based query engine by up to 18.3 times while the memory bandwidth usage drops to only 36.7% on average.

翻译：过去十年间，一系列新型硬件被研究用于加速数据库系统。具体而言，CUDA核心受益于GPU的快速发展，并实现了显著的性能提升。目前最先进的基于GPU的实现方案（即Crystal）相比基于CPU的实现可获得高达61倍的性能提升。然而实验表明，该方法已几乎饱和GPU的全部内存带宽，这意味着进一步性能提升的空间极为有限。本文提出RTCUDB——首个利用GPU中的光线追踪（RT）核心来加速数据库查询处理的查询引擎。RTCUDB将查询求值高效转化为三维空间中的光线追踪任务。通过大幅减少数据访问量，并利用光线追踪机制优化数据访问模式，RTCUDB的性能不再受限于基于CUDA实现中的内存带宽瓶颈。实验结果表明，RTCUDB相比当前最先进的基于GPU的查询引擎可实现最高18.3倍的性能提升，同时内存带宽使用率平均降至仅36.7%。