12 Nov
2007
12 Nov
'07
9:30 p.m.
On 12.11.2007, at 20.14, Rick Romero wrote:
I'm not sure if this would allow multi-master replication though.
I know MySQL offers support for it, but what happens when both masters have added a row that causes a unique key collision? Can you write
triggers to fix those cases automatically?It's taken care of in Mysql 5.0. There's a couple settings: auto_increment_increment = 10 auto_increment_offset = 1 auto_increment_offset = 2 (for other master)
I know that takes care of autoincrement keys, but it's not enough.
There are several other unique keys that can't be handled like that.
Most importantly IMAP UIDs. They must always be increasing. Another
example would be newly created mailbox names.