Re: per table random-page-cost?

On Mon, Oct 19, 2009 at 4:29 PM, Greg Stark <gsstark@mit.edu> wrote:
> On Mon, Oct 19, 2009 at 4:21 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> marcin mank <marcin.mank@gmail.com> writes:
>>>> This proposal is just "hints by the back door", ISTM. As Tom says, there is
>>>> a justification for having it on tablespaces but not on individual tables.
>>
>>> If the parameter is defined as "the chance that a page is in cache"
>>> there is very real physical meaning to it.
>>
>> We have no such parameter...
>
>
> And we want our parameters to be things the DBA has a chance of being
> able to estimate.

Do the current parameters meet that standard?  When setting
seq_page_cost now, don't people have a lot of "Well, we're about this
likely to find it in the cache anyway" built into their settings?


Jeff