Horton

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

Melanie Plageman <melanieplageman@gmail.com>

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From: Melanie Plageman <melanieplageman@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Kirill Reshke <reshkekirill@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, Andrey Borodin <x4mmm@yandex-team.ru>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Heikki Linnakangas <hlinnaka@iki.fi>
Date: 2025-10-14T14:16:24Z
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

On Mon, Oct 13, 2025 at 11:43 PM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Tue, Oct 14, 2025 at 08:31:04AM +0500, Kirill Reshke wrote:
> > Hi! Should we also bump XLOG_PAGE_MAGIC after d96f87332 & add323da40a
> > or do we wait for full set to be committed?
>
> I may be missing something, of course, but d96f87332 has not changed
> the WAL format, VISIBILITYMAP_ALL_VISIBLE and VISIBILITYMAP_ALL_FROZEN
> existing before that.  The change in xl_heap_prune as done in
> add323da40a6 should have bumped the format number.

Oops! Thanks for reporting.

I messed up and forgot to do this. And, if I'm not misunderstanding
the criteria, I did the same thing at the beginning of September with
4b5f206de2bb. I've committed the bump. Hopefully I learned my lesson.

- Melanie