Re: Emit fewer vacuum records by reaping removable tuples during pruning

On Tue, Jan 9, 2024 at 3:40 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Tue, Jan 9, 2024 at 3:13 PM Melanie Plageman
> <melanieplageman@gmail.com> wrote:
> > I had already written the patch for immediate reaping addressing the
> > below feedback before I saw the emails that said everyone is happy
> > with using hastup in lazy_scan_[no]prune() in a preliminary patch. Let
> > me know if you have a strong preference for reordering. Otherwise, I
> > will write the three subsequent patches on top of this one.
>
> I don't know if it rises to the level of a strong preference. It's
> just a preference.

Attached v6 has the immediate reaping patch first followed by the code
to use hastup in lazy_scan_[no]prune(). 0003 and 0004 move the VM
update code into lazy_scan_prune() and eliminate LVPagePruneState
entirely. 0005 moves the FSM update into lazy_scan_[no]prune(),
substantially simplifying lazy_scan_heap().

> I agree that we can leave that out. It wouldn't be bad to include it
> if someone had a nice way of doing that, but it doesn't seem critical,
> and if forcing it in there makes the comment less clear overall, it's
> a net loss IMHO.
>
> > Hmm. Yes. I suppose I was trying to find something to validate. Is it
> > worth checking that the line pointer is not already LP_UNUSED? Or is
> > that a bit ridiculous?
>
> I think that's worthwhile (hence my proposed wording).

Done in attached v6.

- Melanie