On Mon, 12 Feb 2007, Tom Lane wrote:
> This is a real issue, but I think your proposed patch does not fix it.
I certainly wouldn't claim that my patch _fixes_ the problem in the
general case; it provides one way to measure it. Currently it's not
obvious to new pgbench users that the problem even exists at all. I feel
it's important to draw attention to the fact that it's something you
should be aware of, even if an automatic resolution to the problem isn't
obvious yet.
In the context I run pgbench in, it is also a workable fix. I don't even
pay attention to pgbench results unless I'm popping 10,000 (desktop) to
100,000 (server) transactions through it. In that context, I believe it
fairly penalizes the transactions for the data they leave behind for
maintenance. I completely agree that people doing short runs shouldn't
use this switch.
Anyway, I like your idea of describing the lower TPS number as including
maintenance, that matches the terminology used within the documentation
better. I will reformat the output to use that term.
Here's what I'm gonna do. The patch I submitted was prepared with the
goal of possibly being implemented in 8.2. I thought a change to contrib/
that added a feature turned off by default might have a shot at a
backport, and I wanted something people could use on the current release
to be available. Now that I know it's never going into an offical 8.2, I
will prepare a slightly different patch aimed at 8.3--incorporating all
the feedback I've gotten here as either code changes or additional
documentation--and resubmit in another week or so.
Thanks for the feedback.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD