On 06/07/2013 01:00 AM, Josh Berkus wrote: > Daniel, > > So your suggestion is that if archiving is falling behind, we should > introduce delays on COMMIT in order to slow down the rate of WAL writing? Delaying commit wouldn't be enough; consider a huge COPY, which can produce a lot of WAL at a high rate without a convenient point to delay at.
I expect a delay after writing an xlog record would make a more suitable write-rate throttle, though I'd want to be sure the extra branch didn't hurt performance significantly. Branch prediction hints would help; since we don't *care* if the delay branch is slow and causes pipeline stalls, tagging the no-delay branch as likely would probably deal with that concern for supported compilers/platforms. -- Craig Ringer 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
