>> [...]
>> Because the schedule is based on a stochastic process, transactions are not
>> set regularly (that would induce patterns and is not representative of
>> real-life load) but randomly.
>>
>> The long term average is expected to converge to 2 tps, but on a short run
>> it may differ significantly.
>
> Hmm. Is that documented somewhere?
Sure, see --rate option in pgbench doc, which states:
"The rate is targeted by starting transactions along a Poisson-distributed
schedule time line."
The impact on the tps is implied, though.
--
Fabien.