> > Only with ISAM tables which reuse deleted auto_increment numbers. MyISAM
> > tables will give you "Duplicate entry" errors if you hit the maximum.
>
> I hadn't realized this and tested it out in MySQL 3.23.43, but in my tests
> ISAM tables also returned a "Duplicate entry" error when I hit
> the max. Was this "feature" eliminated?
It must have been. I get the same behaviour, but the manual mentions that
ISAM tables used to reuse numbers:
...This will make AUTO_INCREMENT columns faster (at least 10 %) and old
numbers will not be reused as with the old ISAM. Note that when an
AUTO_INCREMENT is defined on the end of a multi-part-key the old behavior is
still present.
from http://www.mysql.com/doc/M/y/MyISAM.html