From: | Andres Freund <andres(at)anarazel(dot)de> |
---|---|
To: | Matthias van de Meent <boekewurm+postgres(at)gmail(dot)com> |
Cc: | Michael Paquier <michael(at)paquier(dot)xyz>, Peter Geoghegan <pg(at)bowt(dot)ie>, Justin Pryzby <pryzby(at)telsasoft(dot)com>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Subject: | Re: pg14b1 stuck in lazy_scan_prune/heap_page_prune of pg_statistic |
Date: | 2021-06-16 19:12:23 |
Message-ID: | 20210616191223.hqwniywylyknzmjw@alap3.anarazel.de |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Hi,
On 2021-06-16 12:59:33 +0200, Matthias van de Meent wrote:
> PFA my adapted patch that fixes this new-ish issue, and does not
> include the (incorrect) assertions in GlobalVisUpdateApply. I've
> tested this against the reproducing case, both with and without the
> fix in GetOldestNonRemovableTransactionId, and it fails fall into an
> infinite loop.
Could you share your testcase? I've been working on a series of patches
to address this (I'll share in a bit), and I've run quite a few tests,
and didn't hit any infinite loops.
> diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
> index 4b600e951a..f4320d5a34 100644
> --- a/src/backend/access/heap/vacuumlazy.c
> +++ b/src/backend/access/heap/vacuumlazy.c
> @@ -1675,6 +1675,12 @@ lazy_scan_heap(LVRelState *vacrel, VacuumParams *params, bool aggressive)
> * that any items that make it into the dead_tuples array are simple LP_DEAD
> * line pointers, and that every remaining item with tuple storage is
> * considered as a candidate for freezing.
> + *
> + * Note: It is possible that vistest's window moves back from the
> + * vacrel->OldestXmin (see ComputeXidHorizons). To prevent an infinite
> + * loop where we bounce between HeapTupleSatisfiesVacuum and
> + * heap_prune_satisfies_vacuum who disagree on the [almost]deadness of
> + * a tuple, we only retry when we know HTSV agrees with HPSV.
> */
HTSV is quite widely used because HeapTupleSatisfiesVacuum is quite
widely used. HPSV isn't, so it's a bit confusing to use this.
Greetings,
Andres Freund
From | Date | Subject | |
---|---|---|---|
Next Message | Andrew Dunstan | 2021-06-16 19:13:30 | Re: pgbench logging broken by time logic changes |
Previous Message | Fabien COELHO | 2021-06-16 19:11:41 | Re: pgbench logging broken by time logic changes |