Re: per table random-page-cost?

marcin mank wrote:
>> I've been thinking about this a bit, too. I've been wondering if it
>> might make sense to have a "random_page_cost" and "seq_page_cost"
>> setting for each TABLESPACE, to compensate for the fact that different
>> media might be faster or slower, and a percent-cached setting for each
>> table over top of that.
>>
>>
>
> I thought about making it per-table, but realistically I think most
> people don`t use tablespaces now. I would not want to be telling
> people "to be able to hint the planner to (not) index-scan the table,
> You must move it to a separate tablespace".
>

This is just plain wrong, in my experience. *Every* large installation I
deal with uses tablespaces.

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 you want to argue for full blown planner hints, that's a whole other
story. Have you read the previous debates on the subject?

cheers