I think your solution is really good. One more time DBA has to solve issues caused by developers that do not know that database calls are expensive and locking is not so difficult to be implemented on application side. It would be better if the developer creates a call to the database and gets 100 keys at one time that he stores in memory in his application and uses the keys from there. Now instead of 100 calls to the database for each record he makes only one for each 100 records.