Most locks used on Teradata Database resources are obtained automatically. Users can upgrade the severity of a lock with the LOCKING request modifier but can not downgrade the severity of a lock. The data integrity requirement of a request determines the type of lock that the system uses.
A request for a resource that is locked by another user is queued (in the case of a conflicting lock level) until the process using the resource releases its lock on that resource. A user can specify that the request be aborted if the lock cannot be obtained immediately.