Re: Psql meta-command conninfo+

I suggest the attached, which gets 99% there with 10% of the
complexity, and has \conninfo (no plus sign) output this:

             Connection Information
       Parámetro       │         Valor          
───────────────────────┼────────────────────────
 Base de Datos         │ alvherre
 Client User           │ alvherre
 Host                  │ 192.168.178.37
 Port                  │ 55432
 Opciones              │ 
 Protocol Version      │ 3
 Password Used?        │ false
 GSSAPI Authenticated? │ false
 Backend PID           │ 1589499
 TLS Connection?       │ true
 TLS Library           │ OpenSSL
 TLS Protocol          │ TLSv1.3
 TLS Key Bits          │ 256
 TLS Cipher            │ TLS_AES_256_GCM_SHA384
 TLS Compression       │ false
 ALPN                  │ postgresql
 Superuser?            │ on
 Hot standby?          │ off
(18 filas)

I have added the parameters is_superuser and in_hot_standby only, and
stayed away from the libpq part of the patch to enumerate parameters.
ISTM a hardcoded list is fine.

Maybe keeping track of 'role' via ParameterStatus messages is a good
idea for reasons unrelated to this patch -- maybe it can be useful for
applications to be aware of role changes -- but I'm not 100% sure about
that, and in particular I'm not sure how heavy the protocol traffic is
going to be if such messages are emitted every time you run a security
invoker function or things like that.  So I'm leaving that part out for
now, and it's easy to do both the libpq patch and \conninfo.


Also, I don't see why we have to keep the current free-format \conninfo.
When you run a query, you get things like

# select 99 as "Luftballons";
 Luftballons 
─────────────
          99

You don't get "There were only 99 Luftballons" or any such nonsense, and I
don't see why \conninfo gets to play different rules.  So I got rid of
\conninfo+.

Do people hate the question marks?

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/