That's DERBY-4693, I believe: https://issues.apache.org/jira/browse/DERBY-4693I hope this is the place to post such issues. I've recently renamed an
identity column, and then found that it no longer functioned as one;
It's fixed in the 10.6 branch, so you could build the fix for your own use.
There's also a 10.6 patch release in the works for the fall: