From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fabien COELHO <coelho@cri.ensmp.fr>
cc: Robert Haas <robertmhaas@gmail.com>,
        Pavel Stehule <pavel.stehule@gmail.com>,
        Corey Huinker <corey.huinker@gmail.com>,
        Daniel Verite <daniel@manitou-mail.org>,
        PostgreSQL Developers <pgsql-hackers@postgresql.org>
Subject: Re: Variable substitution in psql backtick expansion
In-reply-to: <alpine.DEB.2.20.1708260747110.3627@lancre>
References: <bc15034d-b421-42ac-89b1-c3485fa1728b@manitou-mail.org>
 <CAFj8pRDCfLLNfMyNAjDwgHXS7inThdqgCaSbfKpiYXkb6Mvmwg@mail.gmail.com>
 <alpine.DEB.2.20.1704020917220.4632@lancre>
 <CAFj8pRCVFp+68Tt29sZfn9tE28c2D7u_VzTcXrqjyCVBzAzRsA@mail.gmail.com>
 <alpine.DEB.2.20.1704021303300.4632@lancre>
 <CAFj8pRACH1M=egydH4dAAoo9rRVTkuYCaoyZQK2Yf4BTQuRM5w@mail.gmail.com>
 <CADkLM=dzsbgJdP7KAJnbihxU1XFnWZgit9ye5cWnvkjZXyPbGw@mail.gmail.com>
 <alpine.DEB.2.20.1704021805550.4632@lancre>
 <CADkLM=c+hm2rc0tkKgC-ZgrLttHT2KkfppE+BC-=i-xj+7V-TQ@mail.gmail.com>
 <3926.1491159242@sss.pgh.pa.us> <alpine.DEB.2.20.1704022151080.9265@lancre>
 <CAFj8pRDyaC+FaSxd92CLcuV+UFGhwY7NVVBhqFvxPkhvKNhyww@mail.gmail.com>
 <alpine.DEB.2.20.1705211737030.6053@lancre>
 <CA+TgmobT3rD6jaZMCs=PWH_khMu6Bb4TwX+r4tbTNA41hx32=w@mail.gmail.com>
 <13303.1503698976@sss.pgh.pa.us>
 <CA+TgmobXCcEM7uB8_g+tKfB-1gvEyp+Qmmre9bcXU9mgpmW38Q@mail.gmail.com>
 <14596.1503701034@sss.pgh.pa.us> <alpine.DEB.2.20.1708260747110.3627@lancre>
Comments: In-reply-to Fabien COELHO <coelho@cri.ensmp.fr>
	message dated "Sat, 26 Aug 2017 08:08:50 +0200"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <20785.1503760136.1@sss.pgh.pa.us>
Date: Sat, 26 Aug 2017 11:08:56 -0400
Message-ID: <20786.1503760136@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Fabien COELHO <coelho@cri.ensmp.fr> writes:
>> OK, but if human-friendly display is the use-case then it ought to
>> duplicate what psql itself would print in, eg, the startup message about
>> server version mismatch.  The v4 patch does not, in particular it neglects
>> PQparameterStatus(pset.db, "server_version").  This would result in
>> printing, eg, "11.0" when the user would likely rather see "11devel".

> I understand that you would prefer VERSION_NAME to show something like
>    "11devel, server 9.6.4"

No, that's not what I said.  I'm just complaining that as the patch stands
it will set SERVER_NAME to "11.0", where I think it should say "11devel"
(as of today).

> In summary, my prefered option is to have:
>    CLIENT_VERSION "PostgreSQL 11devel on ..."
>    CLIENT_VERSION_NAME "11devel"
>    CLIENT_VERSION_NUM 110000

I don't think we want to drop :VERSION; that would accomplish little
beyond breaking existing scripts.  Plausible choices include duplicating
it, like:

   VERSION "PostgreSQL 11devel on ..."
   CLIENT_VERSION "PostgreSQL 11devel on ..."
   CLIENT_VERSION_NAME "11devel"
   CLIENT_VERSION_NUM 110000

or just ignoring the discrepancy:

   VERSION "PostgreSQL 11devel on ..."
   CLIENT_VERSION_NAME "11devel"
   CLIENT_VERSION_NUM 110000

or just leaving "CLIENT" implicit for all of these variables:

   VERSION "PostgreSQL 11devel on ..."
   VERSION_NAME "11devel"
   VERSION_NUM 110000

Robert seems to prefer the last of those, and that'd be fine with me.
(Note that CLIENT is ambiguous anyway: does it mean psql itself, or
libpq?)

>    SERVER_VERSION_NAME "9.6.4"
>    SERVER_VERSION_NUM 090604

I'm on board with this, except I don't think we should have any leading
zero in the numeric form.  There are contexts where somebody might think
that means octal.

			regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers