Re: What about utility to calculate planner cost constants?

Tom Lane wrote:
>
> And you can't just dismiss the issue of wrong cost models and say we can
> get numbers anyway.

Is there a way to see more details about the cost estimates.
EXPLAIN ANALYZE seems to show the total time and rows; but not
information like how many disk pages were accessed.

I get the feeling that sometimes the number of rows is estimated
very well, but the amount of disk I/O is way off.

Sometimes the number of pages read/written is grossly
overestimated (if tables lave a lot of locally clustered data)
or underestimated if a sort barely exceeds sort_mem.


Perhaps an EXPLAN ANALYZE VERBOSE that would add info like this:

    Index scan ([...]estimated 1000 pages read)  (actual[...] 10 pages read)

would help track those down?