Re: pgbench Comparison of 7.4.7 to 8.0.2

"Thomas F.O'Connell" <tfo(at)sitening(dot)com> writes:
> http://www.sitening.com/pgbench.html

You need to run *many* more transactions than that to get pgbench
numbers that aren't mostly noise. In my experience 1000 transactions
per client is a rock-bottom minimum to get repeatable numbers; 10000 per
is better.

Also, in any run where #clients >= scaling factor, what you're measuring
is primarily contention to update the "branches" rows. Which is not
necessarily a bad thing to check, but it's generally not the most
interesting performance domain (if your app is like that you need to
redesign the app...)

> To me, it looks like basic transactional performance is modestly
> improved at 8.0 across a variety of metrics.

That's what I would expect --- we usually do some performance work in
every release cycle, but there was not a huge amount of it for 8.0.

However, these numbers don't prove much either way.

regards, tom lane