On Fri, Nov 30, 2012 at 8:32 AM, Jamie Holly wrote:
This isn't the case in D7. UID is assigned by a SELECT MAX(uid) FROM {users}. Check user.module line 571.
Unless the whole users table is locked then this is guaranteed to fail under heavy use. Some poor user is going to get a DB error of duplicate key. The chances may be small but there is a chance it will happen. Do you know the issue # that caused this to happen?