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 [EMAIL PROTECTED] http://www.gregsmith.com Baltimore, MD ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend