Re: 8.2 and 8.3 postgresql.conf oddity

"Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com> writes:
> On Jan 23, 2008 4:22 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> What do you find odd about it? Whatever scale you choose to think these
>> values are in, they all have to be on the same scale.

> So they are not defined in relation compared to the sequential page
> fetch cost as they were before?

Well, you could choose to stick to the traditional scale, in which
seq_page_cost is always 1.0 and everything else is relative to that.
Or you could try to make them all measure actual milliseconds on
your actual machine. Or something else.

> I mean, if I change seq_page_cost
> only, it doesn't change the overall behaviour?

Certainly it would. If you multiply *all* the cost constants by the same
factor, then the behavior wouldn't change.

regards, tom lane