My opinion is that this is not particularly useful and not appropriate
to piggy-back onto \conninfo. Connection information including host,
port, database, user name is a well-established concept in PostgreSQL
programs and tools and it contains a delimited set of information.
Knowing what server and what database you are connected to also seems
kind of important. Moreover, this is information that is under control
of the client, so it must be tracked on the client side.
Knowing how long you've been connected on the other hand seems kind of
fundamentally unimportant. If we add that, what's to stop us from
adding other statistics of minor interest such as how many commands
you've run, how many errors there were, etc. The connection time is
already available, and perhaps we should indeed make it a bit easier to
get, but it doesn't need to be a psql command.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services