Re: Initial 9.2 pgbench write results

On Mon, Feb 27, 2012 at 1:08 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Mon, Feb 27, 2012 at 3:50 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> That isn't the case. We have evidence that the current knobs are
>> hugely ineffective in some cases.
>>
>> Turning the bgwriter off is hardly "adjusting a setting", its
>> admitting that there is no useful setting.
>>
>> I've suggested changes that aren't possible by tuning the current knobs.
>
> OK, fair point.  But I don't think any of us - Greg included - have an
> enormously clear idea why turning the background writer off is
> improving performance in some cases.  I think we need to understand
> that better before we start changing things.

I wasn't suggesting we make a change without testing. The theory that
the bgwriter is doing too much work needs to be tested, so we need a
proposal for how to reduce that work in a coherent way so we can test,
which is what I've given. Other proposals are also possible.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
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