Re: BitmapHeapScan streaming read user and prelim refactoring

On Wed, Feb 19, 2025 at 4:14 PM Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
>
> Attached v30 makes the tuple offset extraction happen later as you
> suggested. It turns out that none of the users need to worry much
> about allocating and freeing -- I was able to have all users make an
> offsets array on the stack. Personally I don't think we should worry
> about making a smaller array when fewer offsets are needed.
>
> Even without the read stream API, in bitmap heap scan, delaying
> extraction of the offsets lets us skip doing so for the prefetch
> iterator -- so that's kind of cool. Anyway, we are going to get rid of
> the prefetch iterator, so I won't belabor the point.
>
> I was worried the patch would be too big of a change to the tidbitmap
> API for this late in the cycle, but it turned out to be a small patch.
> I'd be interested in what folks think.

Attached v31 has some updates after self-review and some off-list
feedback from Andres. They're minor changes, so I won't enumerate
them.

- Melanie