Re: BUG #9553: why bitmap index scan startup_cost=0? it's a bug?

digoal@126.com writes:
>  Bitmap Heap Scan on public.t11  (cost=93.95..354.20 rows=10020 width=4)
> (actual time=1.447..3.907 rows=9999 loops=1)
>    Output: id
>    Recheck Cond: (t11.id < 10000)
>    Buffers: shared hit=22
>    ->  Bitmap Index Scan on t11_pkey  (cost=0.00..91.44 rows=10020 width=0)
> (actual time=1.370..1.370 rows=9999 loops=1)
>          Index Cond: (t11.id < 10000)
>          Buffers: shared hit=8
>  Total runtime: 4.931 ms

We don't bother to store/show the indexscan's startup cost in such cases,
since it has no effect whatsoever on subsequent planning: the total cost
of the indexscan will go into the parent's startup cost anyway.

            regards, tom lane