Re: pg_cancel_backend by non-superuser

"""
In *every* case -- and there are many -- where we've had people
express pain, this would have sufficed.  Usually the problem is a
large index creation gone awry, or an automated backup process
blocking a schema change that has taken half the locks it needs, or
something like that -- all by the same role that is under control of
the folks feeling distress.  If this minimal set is uncontroversial, I
would like to see that much committed and then spend some time
hand-wringing on whether to extend it.

If one does want to extend it, I think role inheritance makes the most
sense: a child role should be able to cancel its parent role's
queries, and not vice-versa. Since one can use SET ROLE in this case
anyway to basically act on behalf on that role, I think that, too,
should be uncontroversial.
"""

I would be a step in the right direction if the DB owner would see all queries
to the DB in pg_stat_activity.
- Anssi