Comments on: InnoDB DDL: kudos to quick responders on bugs.mysql.com

By: shlomi

shlomi — Sat, 20 Oct 2012 12:03:23 +0000

@Marko,

node1 (sakila) > select version();
+--------------+
| version()    |
+--------------+
| 5.6.7-rc-log |
+--------------+

By: Marko Mäkelä

Marko Mäkelä — Fri, 19 Oct 2012 19:22:41 +0000

Which version have you been testing? Version 5.6.7 and even the upcoming 5.6.8 will contain some bugs in this area. I have been busy fixing them before the GA release. 🙂

The point of online ALTER TABLE is that writes are allowed, even when the operation requires that the table be copied.

By: shlomi

shlomi — Thu, 18 Oct 2012 18:03:40 +0000

@Justin,
Thanks for the quick info. That’ I must say, is not nearly as I was expecting.

By: Justin Swanhart

Justin Swanhart — Thu, 18 Oct 2012 17:33:55 +0000

When the manual says that “some other operations are non-blocking”, I think they mean they don’t block reads, even though they require a table copy.

This should probably be clarified by the docs team.

–Justin

By: Justin Swanhart

Justin Swanhart — Thu, 18 Oct 2012 17:31:33 +0000

Bascially only index creation and deletion can be done online without locks.

This includes adding/dropping foreign keys online, but only if you set foreign_key_checks=0.

http://dev.mysql.com/doc/refman/5.6/en/innodb-online-ddl.html