From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Fujii Masao <masao.fujii@oss.nttdata.com>,
        Alexey Kondratov <a.kondratov@postgrespro.ru>,
        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
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Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Fri, 10 Apr 2020 14:06:41 -0700"
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Date: Fri, 10 Apr 2020 17:17:10 -0400
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Andres Freund <andres@anarazel.de> writes:
> On 2020-04-10 16:29:39 -0400, Tom Lane wrote:
>> Good point, but we could address that by making it a procedure no?

> Probably. Don't think we have great infrastructure for builtin
> procedures yet though? We'd presumably not want to use plpgsql.

Don't think anyone's tried yet.  It's not instantly clear that the
amount of code needed would be more than comes along with new
syntax, though.

> ISTM that we can make it BEGIN AFTER 'xx/xx' or such, which'd not
> require any keywords, it'd be easier to use than a procedure.

I still don't see a good argument for tying this to BEGIN.  If it
has to be a statement, why not a standalone statement?

(I also have a lurking suspicion that this shouldn't be SQL at all
but part of the replication command set.)

			regards, tom lane