Re: explanation for random_page_cost is outdated

On Mon, Apr 27, 2020 at 12:16:30PM -0400, Bruce Momjian wrote:
> On Mon, Apr 27, 2020 at 06:02:41AM +0200, Pavel Stehule wrote:
> >      >  Storage that has a low random read cost relative to sequential, e.g.
> >     solid-state drives, might also be better modeled with a value that is close
> >     to 1 for random_page_cost.
> > 
> > 
> > I depends on estimation. Lot of people use random_page_cost as fix of broken
> > estimation. Then configures this value to some strange values. Lot of other
> > queries with good estimation can be worse then.
> 
> I have been recommending 1.1 as a value for random_page_cost for SSDs
> for years, and I think it would be helpful to suggest that value, so doc
> patch attached.

Patch applied back through 9.5.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

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