Given current naming of options, I would call this --partitions=number-of-partitions and --partition-method=hash
# then run sh> pgench -S -M prepared -P 1 -T 10
# and look at latency: # no parts = 0.071 ms # 1 hash = 0.071 ms (did someone optimize this case?!) # 2 hash ~ 0.126 ms (+ 0.055 ms) # 50 hash ~ 0.155 ms # 100 hash ~ 0.178 ms # 150 hash ~ 0.232 ms # 200 hash ~ 0.279 ms # overhead ~ (0.050 + [0.0005-0.0008] * nparts) ms