We have replication set up on some MyISAM servers, in a master/save scenario, MySQL v5.1.
One of the columns is currently declared as VARCHAR(255). We want to increase this to VARCHAR(512).
We have one master and 4 slaves. What is the best scenario to make the change.
If we do this:
ALTER TABLE item MODIFY url VARCHAR(512)
should that be ok, as long as we update the slaves first and then the master, or may it complain and it's best to do them all at once? Should I stop the slaves?
I've tried the update on a dev machine which takes about 10 mins, but it doesn't have replication set there. So looking for any flaws in my thinking.
Or looking further, does ALTER TABLE get replicated, and that's all I would need to do on the master?