Date: Fri, 2 Sep 2022 06:55:52 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Andres Freund <andres@anarazel.de>,
	Ashutosh Sharma <ashu.coek88@gmail.com>,
	Maciek Sakrejda <m.sakrejda@gmail.com>,
	Bruce Momjian <bruce@momjian.us>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Andrew Dunstan <andrew@dunslane.net>,
	Heikki Linnakangas <hlinnaka@iki.fi>,
	pgsql-hackers@lists.postgresql.org,
	Thomas Munro <thomas.munro@gmail.com>
Subject: Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints
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On Tue, Aug 02, 2022 at 12:50:43PM -0500, Justin Pryzby wrote:
> Also, if I understand correctly, this patch seems to assume that nobody is
> connected to the source database.  But what's actually enforced is just that
> nobody *else* is connected.  Is it any issue that the current DB can be used as
> a source?  Anyway, both of the above problems are reproducible using a
> different database.
> 
> |postgres=# CREATE DATABASE new TEMPLATE postgres STRATEGY wal_log;
> |CREATE DATABASE

On Thu, Aug 04, 2022 at 05:16:04PM -0500, Justin Pryzby wrote:
> On Thu, Aug 04, 2022 at 06:02:50PM -0400, Tom Lane wrote:
> > The "invalidation" comment bothered me for awhile, but I think it's
> > fine: we know that no other backend can connect to the source DB
> > because we have it locked,
> 
> About that - is it any problem that the currently-connected db can be used as a
> template?  It's no issue for 2-phase commit, because "create database" cannot
> run in an txn.

Would anybody want to comment on this ?
Is it okay that the *current* DB can be used as a template ?