Tomograph
Mrunal Gawade, Martin L. Kersten · 2013
Query parallelism improves serial query execution performance by orders of magnitude. Getting optimal performance from an already parallelized query plan is however difficult due to its dependency on run time factors such as correct operator scheduling, memory pressure, disk io performance, and operating system noise. Identifying the exact problems in a parallel query execution is difficult due to inter-dependence of these factors.