Re: proposal: psql: psql variable BACKEND_PID

On Fri, Feb 3, 2023 at 5:42 AM Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
wrote:

> Hi
>
> We can simply allow an access to backend process id thru psql variable. I
> propose the name "BACKEND_PID". The advantages of usage are simple
> accessibility by command \set, and less typing then using function
> pg_backend_pid, because psql variables are supported by tab complete
> routine. Implementation is very simple, because we can use the function
> PQbackendPID.
>
> Comments, notes?
>
> Regards
>
> Pavel
>

Interesting, and probably useful.

It needs a corresponding line in UnsyncVariables():

SetVariable(pset.vars, "BACKEND_PID", NULL);

That will set the variable back to null when the connection goes away.