SIMD Accelerates the Probe Phase of Star Joins in Main Memory Databases.

In main memory databases, the joins on star schema tables cost the majority of time, which is dominated by the expensive probe phase. In this paper, we vertically or horizontally vectorize the probe phase using SIMD. In addition, we speed up the vectorized probe by prefetching. As our results show, the vertical vectorized integrated probe is up to 2.19X (2.63X) faster than its scalar version, as well as 3.24X (2.74X) faster than the traditional execution based on the right-deep-tree plans on CPU processors (co-processors).