Joel Jacobson <j...@trustly.com> writes: > We already have xact_start, query_start and backend_start > to get the timestamptz for when different things happened.
> I would like to propose adding a fourth such column, "waiting_start", > which would tell how long time a backend has been waiting. The difficulty with that is it'd require a gettimeofday() call for every wait start. Even on platforms where those are relatively cheap, the overhead would be nasty --- and on some platforms, it'd be astonishingly bad. We sweated quite a lot to get the overhead of pg_stat_activity wait monitoring down to the point where it would be tolerable for non-heavyweight locks, but I'm afraid this would push it back into the not-tolerable range. regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers