On Mon, Apr 23, 2018 at 09:47:07PM -0400, Robert Haas wrote:
> On Mon, Apr 23, 2018 at 7:59 PM, Bruce Momjian <bruce@momjian.us> wrote:
> > So, instead of trying to multiplex multiple sessions in a single
> > operating system process, why don't we try to reduce the overhead of
> > idle sessions that each have an operating system process? We already
> > use procArray to reduce the number of _assigned_ PGPROC entries we have
> > to scan. Why can't we create another array that only contains _active_
> > sessions, i.e. those not in a transaction. In what places can procArray
> > scans be changed to use this new array?
>
> There are lots of places where scans would benefit, but the cost of
> maintaining the new array would be very high in some workloads, so I
> don't think you'd come out ahead overall. Feel free to code it up and
> test it, though.
Well, it would be nice if we new exactly which scans are slow for a
large number of idle sessions, and then we could determine what criteria
for that array would be beneficial --- that seems like the easiest place
to start.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
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