If running against a DB2 for z/OS database, any handcrafted SQL that explicitly uses a FOR UPDATE clause may need to be modified to prevent RecordLockedException errors from being thrown. If the particular SQL statement is invoked simultaneously by multiple users, you should consider using FOR UPDATE WITH RS USE AND KEEP UPDATE LOCKS instead. The locking behavior of DB2 for z/OS is subtly different to that of DB2 on distributed platforms. The KEEP UPDATE LOCKS syntax ensures that the locking behavior with DB2 for z/OS is the same as it is on distributed platforms.