Horton

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

Melanie Plageman <melanieplageman@gmail.com>

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From: Melanie Plageman <melanieplageman@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Peter Geoghegan <pg@bowt.ie>, Michael Paquier <michael@paquier.xyz>, Pg Hackers <pgsql-hackers@postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2024-01-19T02:23:44Z
Lists: pgsql-hackers

Attachments

On Thu, Jan 18, 2024 at 3:20 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Thu, Jan 18, 2024 at 10:09 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > Oh, I see. Good catch.
> >
> > I've now committed 0001.
>
> I have now also committed 0002 and 0003. I made some modifications to
> 0003. Specifically:
>
> - I moved has_lpdead_items inside the loop over blocks instead of
> putting it at the function toplevel.
> - I adjusted the comments in lazy_scan_prune() because it seemed to me
> that the comment about "Now scan the page..." had gotten too far
> separated from the loop where that happens.
> - I combined two lines in an if-test because one of them was kinda short.
>
> Hope that's OK with you.

Awesome, thanks!

I have attached a rebased version of the former 0004 as v11-0001.

- Melanie

Commits

  1. Combine FSM updates for prune and no-prune cases.

  2. Remove LVPagePruneState.

  3. Move VM update code from lazy_scan_heap() to lazy_scan_prune().

  4. Optimize vacuuming of relations with no indexes.

  5. Be more consistent about whether to update the FSM while vacuuming.

  6. Remove hastup from LVPagePruneState.

  7. Use scanned_pages to decide when to failsafe check.

  8. Simplify lazy_scan_heap's handling of scanned pages.

  9. While vacuuming a large table, update upper-level FSM data every so often.