Accelerating Database Query Processing on OpenCL-based FPGAs (Abstract Only)

Abstract

The release of OpenCL support for FPGAs represents a significant improvement in extending database applications to the reconfigurable domain. Taking advantage of the programmability offered by the OpenCL HLS tool, an OpenCL database can be easily ported and re-designed for FPGAs. A single SQL query in these database systems usually consists of multiple operators, and each one of these operators in turn consists of multiple OpenCL kernels. Due to the specific properties of FPGAs, each OpenCL kernel can have different optimization combinations (in terms of CU and SIMD) which is critical to the overall performance of query processing. In this paper, we propose an efficient method to implement database operators on OpenCL-based FPGAs. We use a cost model to determine the optimum query plan for an input query. Our cost model has two components: unit cost and query plan generation. The unit cost component generates multiple (unit cost, resource utilization) pairs for each kernel. The query plan generation component employs a dynamic programming approach to generate the optimum query plan which consider the possibilities to use multiple FPGA images. The experiments show that 1) our cost model can accurately predict the performance of each feasible query plan for the input query, and is able to guide the generation of the optimum query plan, 2) our optimized query plan achieves a performance speedup 1.5X-4X over the state-of-the-art query processing on OpenCL-based FPGAs.