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From: Amit Kapila <amit.kapila16@gmail.com>
Date: Thu, 19 Jan 2023 18:29:05 +0530
Message-ID: <CAA4eK1+Z_z7hUB8uOouRrM5kUD_BDbopvLJfFrBONyyVqC9hiQ@mail.gmail.com>
Subject: Re: Time delayed LR (WAS Re: logical replication restrictions)
To: vignesh C <vignesh21@gmail.com>
Cc: "Takamichi Osumi (Fujitsu)" <osumi.takamichi@fujitsu.com>, Peter Smith <smithpb2250@gmail.com>, 
	Kyotaro Horiguchi <horikyota.ntt@gmail.com>, 
	"Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, 
	"shveta.malik@gmail.com" <shveta.malik@gmail.com>, "dilipbalaut@gmail.com" <dilipbalaut@gmail.com>, 
	"euler@eulerto.com" <euler@eulerto.com>, "m.melihmutlu@gmail.com" <m.melihmutlu@gmail.com>, 
	"andres@anarazel.de" <andres@anarazel.de>, "marcos@f10.com.br" <marcos@f10.com.br>, 
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
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On Thu, Jan 19, 2023 at 4:25 PM vignesh C <vignesh21@gmail.com> wrote:
>
> On Thu, 19 Jan 2023 at 12:06, Takamichi Osumi (Fujitsu)
> <osumi.takamichi@fujitsu.com> wrote:
> >
> > Updated the comment and the function call.
> >
> > Kindly have a look at the updated patch v17.
>
> Thanks for the updated patch, few comments:
> 1) min_apply_delay was accepting values like '600 m s h', I was not
> sure if we should allow this:
> alter subscription sub1 set (min_apply_delay = ' 600 m s h');
>

I think here we should have specs similar to recovery_min_apply_delay.

>
> 2) How about adding current_txn_wait_time in
> pg_stat_subscription_stats, we can update the current_txn_wait_time
> periodically, this will help the user to check approximately how much
> time is left(min_apply_delay - stat value) before this transaction
> will be applied in the subscription. If you agree this can be 0002
> patch.
>

Do we have any similar stats for recovery_min_apply_delay? If not, I
suggest let's postpone this to see if users really need such a
parameter.

-- 
With Regards,
Amit Kapila.