From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, a.akenteva@postgrespro.ru,
        a.korotkov@postgrespro.ru, i.kartyshov@postgrespro.ru,
        amit.kapila16@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: [HACKERS] make async slave to wait for lsn to be replayed
In-reply-to: <880834ee-4b18-6d5d-9dae-6520c5eb2bef@oss.nttdata.com>
References: <20200408.100945.375702947246835193.horikyota.ntt@gmail.com>
 <d3ff2e363af60b345f82396992595a03@postgrespro.ru>
 <13716.1586378146@sss.pgh.pa.us>
 <20200409.161107.580344062273684114.horikyota.ntt@gmail.com>
 <880834ee-4b18-6d5d-9dae-6520c5eb2bef@oss.nttdata.com>
Comments: In-reply-to Fujii Masao <masao.fujii@oss.nttdata.com>
	message dated "Thu, 09 Apr 2020 16:35:22 +0900"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <27170.1586439221.1@sss.pgh.pa.us>
Content-Transfer-Encoding: quoted-printable
Date: Thu, 09 Apr 2020 09:33:41 -0400
Message-ID: <27171.1586439221@sss.pgh.pa.us>
Precedence: bulk

Fujii Masao <masao.fujii@oss.nttdata.com> writes:
> On 2020/04/09 16:11, Kyotaro Horiguchi wrote:
>> At Wed, 08 Apr 2020 16:35:46 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote =
in
>>> Why is this getting grafted onto BEGIN/START TRANSACTION in the
>>> first place?

>> The rationale for not being a fmgr function is stated in the following
>> comments. [...]

> This issue happens because the function is executed after BEGIN? If yes,
> what about executing the function (i.e., as separate transaction) before=
 BEGIN?
> If so, the snapshot taken in the function doesn't affect the subsequent
> transaction whatever its isolation level is.

I wonder whether making it a procedure, rather than a plain function,
would help any.

			regards, tom lane