On Thu, Sep 10, 2009 at 9:57 AM, Robert Haas
<robertmhaas@gmail.com> wrote:
2009/9/10 <tv@fuzzy.cz>:
>> Playing around with seq_page_cost (1) and random_page_cost (1), I can get
>> the correct index selected. Applying those same settings to our production
>> server does not produce the optimal plan, though.
>
> I doubt setting seq_page_cost and random_page_cost to the same value is
> reasonable - random access is almost always more expensive than sequential
> access.
If the data figures to be read from the OS cache, it's very
reasonable, and the right value is somewhere in the 0.05 - 0.10 range.
For the most part, it will indeed be cached. Thanks for the tip on the values.