On Fri, Mar 18, 2011 at 9:27 AM, Markus Wanner <mar...@bluegap.ch> wrote: > Google invented the term "semi-syncronous" for something that's > essentially the same that we have, now, I think. However, I full > heartedly hate that term (based on the reasoning that there's no > semi-pregnant, either).
We didn't invent the term, we just implemented something that Heikki Tuuri briefly described, for example: http://bugs.mysql.com/bug.php?id=7440 In the Google patch and official MySQL version, the sequence is: 1) commit on master 2) wait for slave to ack 3) return to user After step 1 another user on the master can observe the commit and the following is possible: 1) commit on master 2) other user observes that commit on master 3) master blows up and a user observed a commit that never made it to a slave I do not think this sequence should be possible in a sync replication system. But it is possible in what has been implemented for MySQL. Thus it was named semi-sync rather than sync. -- Mark Callaghan mdcal...@gmail.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
