On 2017-01-06 10:43:32 -0500, Bruce Momjian wrote: > On Thu, Jan 5, 2017 at 06:48:17PM -1000, Joel Jacobson wrote: > > On Thu, Jan 5, 2017 at 4:59 PM, Bruce Momjian <br...@momjian.us> wrote: > > > Agreed. No need in adding overhead for short-lived locks because the > > > milli-second values are going to be meaningless to users. I would be > > > happy if we could find some weasel value for non-heavyweight locks. > > > > To avoid a NULL value for waiting_start, and thanks to non-heavyweight > > locks don't exceed order-of-milliseconds, I think it would be > > acceptable to just return now() whenever something wants to know > > waiting_start i.e. when something selects from pg_stat_activity. > > > > The exact value would only be within orders-of-milliseconds away from > > now() anyway, so one can argue it's not that important, as long as the > > documentation is clear on that point. > > I don't think now() is a good value as it doesn't indicate to the user > which values are real measurements and which are not. NULL is probably > the best. +/-infinity is odd too.
Yea. If one wants to make NULL into now() it's trivial enough with a single coalesce(). Andres -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers