> > This is wrong assumption. If > > > > 1st client executes UPDATE t SET a = 1 WHERE b = 2; > > 2nd client executes UPDATE t SET a = 2 WHERE b = 2; > > > > at "the same time" you don't know in what order these > > queries will be executed on two different servers (because > > you can't control what transaction will lock record(s) > > for update first). > > I guess we would need two phase commit in this case. Then it could be > guaranteed. > I'm not sure 2PC would guarantee order here. There is potential for a dead lock across system boundary in this example. If the pre commit messages were sent at the same time which server would lock the resource?
Darren ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
