Re: improve transparency of bitmap-only heap scans

On Mon, Mar 16, 2020 at 9:08 AM James Coleman <jtc331(at)gmail(dot)com> wrote:
> ...
> One question though: if I change the query to:
> explain (analyze, buffers) select count(*) from exp where a between 50
> and 100 and d between 5 and 10;
> then I get a parallel bitmap heap scan, and I only see exact heap
> blocks (see attached explain output).
>
> Does the original optimization cover parallel bitmap heap scans like
> this? If not, I think this patch is likely ready for committer. If so,
> then we still need support for stats tracking and explain output for
> parallel nodes.

I've looked at the code a bit more deeply, and the implementation
means the optimization applies to parallel scans also. I've also
convinced myself that the change in explain.c will cover both
non-parallel and parallel plans.

Since that's the only question I saw, and the patch seems pretty
uncontroversial/not requiring any real design choices, I've gone ahead
and marked this patch as ready for committer.

Thanks for working on this!

James