Teradata Parallel Transporter (TPT) is a Teradata tool for Extraction Transformation and Loading. It offers a native, scalable and parallel way of loading the Teradata database.
A TPT script runs in two subsequent phases – Acquisition and Application phase. In the acquisition phase are data delivered to their designated AMPs. During the application phase are data sorted based on row hash sequence and stored to disk.
It might sometimes happen the TPT process fails or gets interrupted leaving a lock on the target table. Therefore, when TPT gets restarted, one receives the 2574 error.
One way around this is dropping and recreating the locked table or another releasing the lock manually using the RELEASE MLOAD command. Depending on in which phase a load gets interrupted one uses the RELEASE command with/without the IN APPLY parameter:
/* Acquisition phase */
RELEASE MLOAD databasename.tablename;
/* Application phase */
RELEASE MLOAD databasename.tablename IN APPLY;
Additional information: Teradata Documentation