Re: Feature request: make cluster_name GUC useful for psql prompts

That is almost identical to the solution I suggested a week or two ago to
someone tackling the issue and the hack works on initial connection.

Connect to a different cluster with "\c", however, and it will leave the
prompt showing you connected to the original database which is not good.

Cheers,
Steve

On Fri, May 6, 2016 at 11:42 AM, Jerry Sievers <gsievers19(at)comcast(dot)net>
wrote:

> Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
>
> > On 5/5/16 9:21 PM, Steve Crawford wrote:
> >
> >> Adding an escape sequence that references cluster_name would enable
> >> prompts to identify the cluster in a manner that is both consistent and
> >> distinct regardless of access path.
> >
> > I think that would be a good idea. You could probably design it so
> > that any server parameter reported to the client can be put in a psql
> > prompt.
>
> The OP can easily work around that lack of support with something such as
> follow...
>
> Add this to ~/.psqlrc[-optional version stuff]
>
> select setting as cluster_name from pg_settings where name =
> 'cluster_name' -- do not simicolon terminate this line
> \gset
>
> \set PROMPT1 :cluster_name ': how cool is this:'
>
> >
> >> Potential issues/improvements:
> >>
> >> What should the escape-sequence display if cluster_name is not set or
> >> the cluster is a pre-9.5 version. %M? %m?
> >>
> >> In future server versions should there be a default for cluster_name if
> >> it is not set? If so, what should it be? Would the server canonical
> >> hostname + listen-port be reasonable?
> >
> > Those are good questions. I don't really like the proposed answers,
> > because that could cause confusion in practical use.
> >
> > --
> > Peter Eisentraut http://www.2ndQuadrant.com/
> > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>
> --
> Jerry Sievers
> Postgres DBA/Development Consulting
> e: postgres(dot)consulting(at)comcast(dot)net
> p: 312.241.7800
>