>>"Though each nd every DML statement in Teradata is Auto commit"
That's not true. You can declare explicit transactions in Teradata, both in Teradata mode and ANSI mode.
In ANSI mode it works as always: COMMIT/ROLLBACK.
In Teradata mode you use 'END TRANSACTION' to commit and 'ROLLBACK/ABORT' to rollback (the system automatically rolls back transactions upon an error though).