> > commit_delay exists to artificially increase the window in which the > leader backend waits for more group commit followers. At higher client > counts, that isn't terribly useful because you'll naturally have > enough clients anyway, but at lower client counts particularly where > fsyncs have high latency, it can help quite a bit. I mention this > because clearly commit_delay is intended to trade off latency for > throughput. Although having said that, when I worked on commit_delay, > the average and worse-case latencies actually *improved* for the > workload in question, which consisted of lots of small write > transactions. Though I wouldn't be surprised if you could produce a > reasonable case where latency was hurt a bit, but throughput improved.
Thanks for your reply. The logic says that latency will be hit when commit_delay is applied, but I am really interested in why we get an improvement instead. Can small writes be the reason? Regards, Atri -- Regards, Atri l'apprenant -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
