On Jul 15, 2011, at 8:55 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > On Fri, Jul 15, 2011 at 2:29 PM, Robert Haas <robertmh...@gmail.com> wrote: > >> If the primary goal here is to reduce power consumption, another option >> would be to keep the regular wake-ups most of the time but have some >> mechanism for putting the process to sleep until wakened when no activity >> happens for a certain period of time - say, 10 cycles. I'm not at all sure >> that's better, but it would be less of a change to the existing behavior. > > Now we have them, latches seem the best approach because they (mostly) > avoid heuristics.
That's my feeling as well. > This proposal works same or better for async transactions. Right. I would say probably better. The potential for a reduction in latency here is very appealing. > The only difference is how bulk write operations are handled. As long > as we wake WALWriter before wal_buffers fills then we'll be good. > Wakeup once per wal buffer is too much. I agree we should measure this > to check how frequently wakeups are required for bulk ops. Yeah. The trick is to get the wake-ups to be frequent enough without adding too much latency to the backends that have to perform them. Off-hand, I don't have a good feeling for how hard that will be. ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
