Horton

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

Melanie Plageman <melanieplageman@gmail.com>

View thread
From: Melanie Plageman <melanieplageman@gmail.com>
To: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Cc: Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>
Date: 2025-07-11T22:19:15Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Remove table_scan_analyze_next_tuple unneeded parameter OldestXmin

  2. Simplify visibility check in heap_page_would_be_all_visible()

  3. Eliminate use of cached VM value in lazy_scan_prune()

  4. Combine visibilitymap_set() cases in lazy_scan_prune()

  5. Fix const qualification in prune_freeze_setup()

  6. Simplify vacuum visibility assertion

  7. Split heap_page_prune_and_freeze() into helpers

  8. Assert that cutoffs are provided if freezing will be attempted

  9. Split PruneFreezeParams initializers to one field per line

  10. Refactor heap_page_prune_and_freeze() parameters into a struct

  11. Make heap_page_is_all_visible independent of LVRelState

  12. Inline TransactionIdFollows/Precedes[OrEquals]()

  13. Add helper for freeze determination to heap_page_prune_and_freeze

  14. Bump XLOG_PAGE_MAGIC after xl_heap_prune change

  15. Correct prune WAL record opcode name in comment

  16. Add error codes when vacuum discovers VM corruption

  17. Remove unused xl_heap_prune member, reason

  18. Remove unneeded VM pin from VM replay

  19. Add assert and log message to visibilitymap_set

  20. Add error codes to some corruption log messages

Attachments

On Wed, Jul 9, 2025 at 5:59 PM Melanie Plageman
<melanieplageman@gmail.com> wrote:
>
> On Thu, Jun 26, 2025 at 6:04 PM Melanie Plageman
> <melanieplageman@gmail.com> wrote:
> >
> > Rebased in light of recent changes on master:
>
> This needed another rebase, and, in light of the discussion in [1],
> I've also removed the patch to add heap wrappers for setting pages
> all-visible.

Andrey Borodin made the excellent point off-list that I forgot to
remove the xl_heap_visible struct itself -- which is rather important
to a patch set purporting to eliminate xl_heap_visible! New version
attached.


- Melanie