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
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