Re: Changing the default random_page_cost value - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Changing the default random_page_cost value
Date
Msg-id 3863754.1728959881@sss.pgh.pa.us
Whole thread Raw
In response to Re: Changing the default random_page_cost value  (David Rowley <dgrowleyml@gmail.com>)
Responses Re: Changing the default random_page_cost value
List pgsql-hackers
David Rowley <dgrowleyml@gmail.com> writes:
> Yeah, I think any effort to change the default value for this setting
> would require some analysis to prove that the newly proposed default
> is a more suitable setting than the current default. I mean, why 1.2
> and not 1.1 or 1.3? Where's the evidence that 1.2 is the best value
> for this?

Yeah, that's been my main concern about this proposal too.

I recall that when we settled on 4.0 as a good number for
spinning-rust drives, it came out of some experimentation that
I'd done that involved multiple-day-long tests.  I don't recall any
more details than that sadly, but perhaps trawling the mailing list
archives would yield useful info.  It looks like the 4.0 value came
in with b1577a7c7 of 2000-02-15, so late 1999/early 2000 would be the
time frame to look in.

            regards, tom lane



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