Re: Bitmap scan cost model (was Re: bitmap scans, btree

On Wed, 2005-05-18 at 11:27 -0400, Tom Lane wrote:
> "Jeffrey W. Baker" <jwbaker@acm.org> writes:
> > Obviously in this case sequential scan was (would have been) a huge win.
> > Incrementing random_page_cost from 4 (the default) to 5 causes the
> > planner to make a better decision.
> 
> But to get the estimated cost ratio to match up with the actual cost
> ratio, we'd have to raise random_page_cost to nearly 70, which is a bit
> hard to credit.  What was the platform being tested here?

i686 Linux 2.6.8 with a single 7200RPM SATA disk.

-jwb