Re: eliminate xl_heap_visible to reduce WAL (and eventually set VM on-access)

On Mon, 30 Mar 2026 at 06:16, Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
> Attached v48 does a bit more cleanup. No functional changes. I'm
> planning to push this soon. I think my remaining question is whether I
> should move the row marks and result relation bitmaps into the estate.
> I'm leaning toward not doing that and leaving them in the PlannedStmt.
> Anyway, If I want to replace the list of result relation RTIs in the
> PlannedStmt, I have to leave the bitmapset version there.

I looked at v48-0001 and it looks fine to me. I've only minor quibbles
about you using foreach() instead of foreach_int() and foreach_node()
for populating the new Bitmapsets in standard_planner().

I don't see any advantage to adding the fields to EState. There might
be if there was some performance reason, but it looks like you're only
accessing the fields when scans are initialised. It's hard to imagine
an extra pointer deference would matter there. I didn't find any
guidance in any comments to understand if there's a best practise
here, so I assume what's there today is down to people's taste. For
me, I'd say if it's not performance critical and the executor does not
modify the field for any purpose, then keeping it in PlannedStmt is
fine. If someone thinks I'm wrong on that, then a comment at the top
of EState would be helpful.

David