Re: Auto-tuning work_mem and maintenance_work_mem

* Pavel Stehule (pavel(dot)stehule(at)gmail(dot)com) wrote:
> 2013/10/9 Bruce Momjian <bruce(at)momjian(dot)us>
> > I went with shared_buffers because unlike the others, it is a fixed
> > allocation quantity, while the other are much more variable and harder
> > to set. I figured we could keep our 25% estimate of shared_buffers and
> > everything else would fall in line.
> >
>
> I understand, but your proposal change a logic to opposite direction. Maybe
> better is wait to new GUC parameter, and then implement this feature, so be
> logical and simply understandable.

I disagree- having a better default than what we have now is going to
almost certainly be a huge improvement in the vast majority of cases.
How we arrive at the default isn't particularly relevant as long as we
document it. Users who end up using the default don't do so because
they read the docs and said "oh, yeah, the way they calculated the
default makes a lot of sense", then end up using it because they never
open the config file, at all.

In other words, I think the set of people who would appreciate having
the default calculated in a good way has no intersection with the set of
people who *use* the default values, which is the audience that the
default values are for.

Thanks,

Stephen