On Tue, Dec 13, 2016 at 10:05 AM, Craig Ringer <craig@2ndquadrant.com> wrote:
> We should probably expose a proc_type or something, with types:
>
> * client_backend
> * bgworker
> * walsender
> * autovacuum
> * checkpointer
> * bgwriter
A text field is adapted then, more than a single character.
> for simpler filtering.
>
> I don't think existing user code is likely to get upset by more
> processes appearing in pg_stat_activity, and it'll be very handy.
Indeed, for WAL senders now abusing of the query field is definitely
not consistent. Even if having this information is useful, adding such
a column would make sense. Still, one thing that is important to keep
with pg_stat_activity is the ability to count the number of
connections that are part of max_connections for monitoring purposes.
The docs definitely would need an example of such a query counting
only client_backend and WAL senders and tell users that this can be
used to count how many active connections there are.
--
Michael