Re: pgbench throttling latency limit

Hello Heikki,

> Now that I've finished the detour and committed and backpatched the changes 
> to the way latency is calculated, we can get back to this patch. It needs to 
> be rebased.

Before rebasing, I think that there are a few small problems with the 
modification applied to switch from an integer range to double.

(1) ISTM that the + 0.5 which remains in the PoissonRand computation comes 
from the previous integer approach and is not needed here. If I'm not 
mistaken the formula should be plain:
     -log(uniform) * center

(2) I'm not sure of the name "center", I think that "lambda" or    "mean" would be more appropriate.

(3) I wish that the maximum implied multiplier could be explicitely    documented in the source code. From pg_rand48
sourcecode, I think    that it is 33.27106466687737
 

-- 
Fabien.