Re: Variable substitution in psql backtick expansion

Hello Pavel,

>>   \echo :VERSION
>>   PostgreSQL 10devel on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
>> 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609, 64-bit
>>
>> Probably some :VERSION_NUM would make some sense. See attached PoC patch.
>> Would it make sense?
>
> Maybe better name for you CLIENT_VERSION_NUM

If it was starting from nothing I would tend to agree with you, but there 
is already an existing :VERSION variable, so it seemed logical to keep on 
and create variants with the same prefix.

> Can be SERVER_VERSION_NUM taken from connection info?

Probably it could. It seems a little less straightforward than defining a 
client-side string at compile time. The information is displayed when the 
connection is established, so the information is there somewhere.
 psql (10devel, server 9.6.2)

-- 
Fabien.