Re: Variable substitution in psql backtick expansion

On Fri, Aug 25, 2017 at 6:43 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Fri, Aug 25, 2017 at 6:09 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> ... I'm still not sure that there's any use case for the
>>> string versions ("9.6.4" etc).
>
>> If somebody's doing comparisons, they probably want the numeric
>> version, but somebody might want to print the string version in an
>> error message e.g. \if <test involving VERSION_NUM> \echo this thing
>> doesn't work on :VERSION_NAME \quit \endif
>
> 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".

Oh. Well, that seems suboptimal.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company