I have noticed the following behavior to be different in 5.5.4 vs.
5.1. I would just like to confirm that it is intended.
Suppose one thread does:
insert into foo values (1);
and another thread does:
alter table foo add index...
In 5.1, the alter table statement would proceed to make calls into the
handler of the storage engine, and the storage engine would handle
issues. In 5.5.4, the alter table statement blocks until thread one's
transaction commits or aborts.
Is this the intended behavior?