Resetting cluster-wide statistics

There are a few statistics that are only kept on a per-cluster basis, such
as those reported in pg_stat_database and pg_stat_bgwriter. Since
pg_stat_reset only resets per-database counts, it doesn't touch those.

I'd like to have a function that resets those. Maybe iterates over all
the databases while it's at it and clear the whole mess out as another
option. I'm curious why something resetting the cluster-wide stats isn't
available already. Just because nobody bothered to write it before, or is
there some reason why this can't work that I just didn't notice during my
brief scan of pgstat.c?

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* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD