Re: BUG #10144: PostgreSQL cost_index in costsize.c bug? (cann't estimate indexCorrelation correct)

digoal@126.com writes:
> i see postgresql optimizer don't add column's indexCorrelation in index scan
> and then shold not choose optimal scannode.

When I try this test case, I find that the planner prefers a plain
seqscan, then a bitmap scan, and last an indexscan; and the cost estimates
are not too out of line with reality.  I suspect you've changed the
planner's cost parameters to some non-default settings that don't really
square very well with your environment.

            regards, tom lane