| From: | Andres Freund <andres(at)anarazel(dot)de> |
|---|---|
| To: | Amul Sul <sulamul(at)gmail(dot)com> |
| Cc: | Jehan-Guillaume de Rorthais <jgdr(at)dalibo(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> |
| Subject: | Re: [patch] demote |
| Date: | 2020-07-14 19:49:51 |
| Message-ID: | 20200714194951.rzn5yohwwgdo733q@alap3.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Hi,
On 2020-07-14 17:26:37 +0530, Amul Sul wrote:
> On Mon, Jul 13, 2020 at 8:35 PM Jehan-Guillaume de Rorthais
> <jgdr(at)dalibo(dot)com> wrote:
> >
> > Hi,
> >
> > Another summary + patch + tests.
> >
> > This patch supports 2PC. The goal is to keep them safe during demote/promote
> > actions so they can be committed/rollbacked later on a primary. See tests.
> >
>
> Wondering is it necessary to clear prepared transactions from shared memory?
> Can't simply skip clearing and restoring prepared transactions while demoting?
Recovery doesn't use the normal PGXACT/PGPROC mechanisms to store
transaction state. So I don't think it'd be correct to leave them around
in their previous state. We'd likely end up with incorrect snapshots
if a demoted node later gets promoted...
Greetings,
Andres Freund
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Alvaro Herrera | 2020-07-14 19:54:06 | Re: recovering from "found xmin ... from before relfrozenxid ..." |
| Previous Message | Robert Haas | 2020-07-14 19:46:44 | Re: Default setting for enable_hashagg_disk |