Re: relfrozenxid may disagree with row XIDs after 1ccc1e05ae

Noah Misch <noah@leadboat.com>

From: Noah Misch <noah@leadboat.com>

To: Melanie Plageman <melanieplageman@gmail.com>

Cc: Bowen Shi <zxwsbg12138@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Peter Geoghegan <pg@bowt.ie>, Alexander Lakhin <exclusion@gmail.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>

Date: 2024-06-25T19:37:40Z

Lists: pgsql-bugs

Commits

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

Ensure vacuum removes all visibly dead tuples older than OldestXmin
- 06bf404cd07b 16.4 landed
- 45ce054c02b8 14.13 landed
- dc6354c67017 15.8 landed
Combine freezing and pruning steps in VACUUM
- 6dbb490261a6 17.0 cited
Handle non-chain tuples outside of heap_prune_chain()
- 6f47f6883151 17.0 cited
Fix false reports in pg_visibility
- e85662df44ff 17.0 cited
Remove retry loop in heap_page_prune().
- 1ccc1e05ae8f 17.0 cited
vacuumlazy.c: document vistest and OldestXmin.
- 73f6ec3d3c8d 15.0 cited
Deduplicate choice of horizon for a relation procarray.c.
- d9d8aa9bb9aa 15.0 cited
Remove tupgone special case from vacuumlazy.c.
- 8523492d4e34 14.0 cited
Simplify state managed by VACUUM.
- b4af70cb2103 14.0 cited
Recycle nbtree pages deleted during same VACUUM.
- 9dd963ae2534 14.0 cited
snapshot scalability: Don't compute global horizons while building snapshots.
- dc7420c2c927 14.0 cited
Raise error when affecting tuple moved into different partition.
- f16241bef7cc 11.0 cited

On Thu, Jun 20, 2024 at 11:49:50AM -0400, Melanie Plageman wrote:
> On Tue, Jun 18, 2024 at 6:51 PM Melanie Plageman <melanieplageman@gmail.com> wrote:
> > I ended up manually backporting the logic from 1ccc1e05ae as opposed
> > to cherry-picking because it relied on a struct introduced in
> > 4e9fc3a9762065.

> Attached is the backport and repros for 15 and 16.

> When this happends, a tuple with an xmax older than OldestXmin but newer

s/happends/happens/

> @@ -700,7 +707,7 @@ heap_prune_chain(Buffer buffer, OffsetNumber rootoffnum, PruneState *prstate)
>  			break;
>  
>  		Assert(ItemIdIsNormal(lp));
> -		Assert(prstate->htsv[offnum] != -1);
> +		Assert(htsv[offnum] != -1);

The master patch removed this assert instead.  Is the back branch non-removal
deliberate?  If so, the patch is ready.  I also confirm your results from your
repro recipe; thanks for including that.