Subject: Re: file cloning in pg_upgrade and CREATE DATABASE
To: Michael Paquier <michael@paquier.xyz>
References: <20181003014409.GC2609@paquier.xyz>
 <20181003020706.hykmk4vmy6brovoj@alvherre.pgsql>
 <20181010195002.GA7806@momjian.us>
 <325b5baf-adcc-9954-2a55-d67b4f3155f0@2ndquadrant.com>
 <d4bc3dae-fdea-2407-5629-cac68be893a3@2ndquadrant.com>
 <20181018235046.GA2099@paquier.xyz>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>,
 Bruce Momjian <bruce@momjian.us>, Alvaro Herrera <alvherre@2ndquadrant.com>
From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
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Organization: 2ndQuadrant
Message-ID: <98287e67-0f94-d962-e550-bd169a737181@2ndquadrant.com>
Date: Wed, 7 Nov 2018 18:42:00 +0100
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In-Reply-To: <20181018235046.GA2099@paquier.xyz>
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On 19/10/2018 01:50, Michael Paquier wrote:
> On Thu, Oct 18, 2018 at 11:59:00PM +0200, Peter Eisentraut wrote:
>> New patch that removes all the various reflink modes and adds a new
>> option --clone that works similar to --link.  I think it's much cleaner now.
> 
> Thanks Peter for the new version.
> 
> +
> +		{"clone", no_argument, NULL, 1},
> +
>  		{NULL, 0, NULL, 0}
> 
> Why newlines here?

fixed

> @@ -293,6 +300,7 @@ usage(void)
>  	printf(_("  -U, --username=NAME           cluster superuser (default \"%s\")\n"), os_info.user);
>  	printf(_("  -v, --verbose                 enable verbose internal logging\n"));
>  	printf(_("  -V, --version                 display version information, then exit\n"));
> +	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
>  	printf(_("  -?, --help                    show this help, then exit\n"));
>  	printf(_("\n"
> 
> An idea for a one-letter option could be -n.  This patch can live
> without.

-n is often used for something like "dry run", so it didn't go for that
here.  I suspect the cloning will remain a marginal option for some
time, so having only a long option is acceptable.

> +     pg_fatal("error while cloning relation \"%s.%s\": could not open file \"%s\": %s\n",
> +              schemaName, relName, src, strerror(errno));
> 
> The tail of those error messages "could not open file" and "could not
> create file" are already available as translatable error messages.
> Would it be better to split those messages in two for translators?  One
> is generated with pg_fatal("error while cloning relation \"%s.%s\":
> could not open file \"%s\": %s\n",
> +              schemaName, relName, src, strerror(errno));

I think this is too complicated for a few messages.

> Those are all minor points, the patch looks good to me.

Committed, thanks.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services