Re: per-tablespace random_page_cost/seq_page_cost

Andres Freund <andres@anarazel.de> writes:
> On Tuesday 27 October 2009 00:42:39 Tom Lane wrote:
>> I think a design that is limited to a prespecified set of GUCs is
>> broken by definition.  It'd be better to make it work like
>> ALTER DATABASE SET.

> How should that work if there are conflicting settings in two tablespaces when 
> tables from both are used?

Well, most of the settings that would be sensible for this are used in
cost estimates that are basically per-table or per-index, so I don't
think it's a huge problem in practice.  But I should clarify my comment:
the set of GUCs used this way must not be wired into the catalog
structure.  I think that the code will only pay attention to certain
GUCs that are valid in-context, but we shouldn't have to redesign the
catalog each time we add one.
        regards, tom lane