Re: pgbench progress report improvements

I suggest getting the term "stddev" in there somehow, maybe like this:

 progress: 37.0 s, 115.2 tps, latency avg=8.678 ms  stddev=1.792

My issue is to try to keep the line width under control so as to avoid line breaks in the terminal. Under throttling, there is also the time lag appended to the line.

Moreover, using 'xxx=figure" breaks simple "cut" pipelining to extract the figures, so I would prefer to stick to spaces.

Maybe:

  progress: 36.0 s, 115.2 tps, lat avg 9.678 ms stddev 1.792, lag 0.143 ms

but I liked my "+-" approach:-)