On Mon, 9 Sep 2002, Tom Lane wrote:
> Finally, I wouldn't believe the results for a moment if they were taken
> against databases that are not several times the size of physical RAM
> on the test machine, with a total I/O volume also much more than
> physical RAM. We are trying to measure the behavior when kernel
> caching is not helpful; if the database fits in RAM then you are just
> naturally going to get random_page_cost close to 1, because the kernel
> will avoid doing any I/O at all.
Um...yeah; another reason to use randread against a raw disk device.
(A little hard to use on linux systems, I bet, but works fine on
BSD systems.)
cjs
--
Curt Sampson <cjs@cynic.net> +81 90 7737 2974 http://www.netbsd.org Don't you know, in this new Dark Age, we're
alllight. --XTC