Re: new correlation metric

Tom Lane wrote:
> Ron Mayer <rm_pg@cheapcomplexdevices.com> writes:
>> ...bitmap cost estimates didn't also change much....
> 
> By definition, a bitmap scan's cost isn't affected by index order
> correlation.

No?   I think I understand that for index scans the correlation
influenced how many data pages are estimated to get sucked in.

Wouldn't a bitmap scan using a single index also fetch roughly
the same number of data pages as an index scan?

I'm not complaining, since 8.3's doing great on all my real-world
queries.   And sorry for my naive questions - feel free to tell
me to just read the code if this is something I should be able
to figure out myself.