Re: [PATCH] add --throttle to pgbench (submission 3)

Hello Greg,

> If you add this to 
> https://commitfest.postgresql.org/action/commitfest_view?id=18 I'll review it 
> next month.

Ok. Thanks. I just did that.

> I have a lot of use cases for a pgbench that doesn't just run at 100% 
> all the time.  I had tried to simulate something with simple sleep 
> calls, but I realized it was going to take a stronger math basis to do 
> the job well.
>
> The situations where I expect this to be useful all require collecting 
> latency data and then both plotting it and doing some statistical analysis. 
> pgbench-tools computes worst-case and 90th percentile latency for example, 
> along with the graph over time.  There's a useful concept that some of the 
> official TPC tests have:  how high can you get the throughput while still 
> keeping the latency within certain parameters. Right now we have no way to 
> simulate that.  What we see with write-heavy pgbench is that latency goes 
> crazy (>60 second commits sometimes) if all you do is hit the server with 
> maximum throughput.  That's interesting, but it's not necessarily relevant in 
> many cases.

Indeed. It is a good thing that my proposed feature can help in more 
situations than my particular need.

-- 
Fabien.