Re: Emit fewer vacuum records by reaping removable tuples during pruning - Mailing list pgsql-hackers

On Fri, Jan 12, 2024 at 3:04 PM Melanie Plageman
<melanieplageman@gmail.com> wrote:
> Also, I think you should combine these in lazy_scan_noprune() now
>
>     /* Save any LP_DEAD items found on the page in dead_items array */
>     if (vacrel->nindexes == 0)
>     {
>         /* Using one-pass strategy (since table has no indexes) */
>         if (lpdead_items > 0)
>         {
>
> Since we don't set recordfreespace in the outer if statement anymore

Well, maybe, but there's an else clause attached to the outer "if", so
you have to be a bit careful. I didn't think it was critical to
further rejigger this.

> And I noticed you missed a reference to recordfreespace output
> parameter in the function comment above lazy_scan_noprune().

OK.

So what's the best way to solve the problem that Peter pointed out?
Should we pass in the prunestate? Maybe just replace bool
*recordfreespace with bool *has_lpdead_items?

--
Robert Haas
EDB: http://www.enterprisedb.com