On Tue, Jan 31, 2012 at 7:43 AM, Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote:
> That seems like a pretty marginal gain. If you're bound by the speed of > fsyncs, this will reduce the latency by the time it takes to mark the clog, > which is tiny in comparison to all the other stuff that needs to happen, > like, flushing the WAL. And that's ignoring any additional overhead caused > by the signaling between processes. If you're bound by CPU capacity, this > doesn't help at all because it just moves the work around. We're not bound by CPU capacity. Latency is an issue, especially when contention drives it higher with occasional spikes. I expect this to have a good measurable impact, as well as a stabilising effect on the latency. > Anyway, this is quite different from the original goal and patch for group > commit, so can we please leave this for 9.3, and move on with the review of > pending 9.2 patches. Actually, there is very little change here from the original patch. But I would note that your own changes were also quite different, and had no noticeable gain. They were also based on a brand new and radical set of thoughts. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
