![](https://secure.gravatar.com/avatar/99fde0c1dfd216326aae0aff30d493f1.jpg?s=120&d=mm&r=g)
5 Dec
2014
5 Dec
'14
12:01 p.m.
Jonas Oreland
A slightly off topic question that struck me last night: won't all parallel transactions conflict when updating the slave_gtid_pos table ?
They would, if the GTID was not carefully designed in anticipation of this issue. So the GTID position is updated in slave_gtid_pos with an INSERT, not an UPDATE. This way, multiple updates can be done concurrently. Each row in the gtid_slave_pos table contains an incrementing counter, and the highest value of the counter denotes the "current" row at any one time. I wrote a more detailed explanation of this here: http://kristiannielsen.livejournal.com/17008.html - Kristian.