US-ASCII replaced Teradata ASCII (TD-ASCII) as the default character set, while retaining the current ASCII user interface.
For compatibility with international character sets, Teradata recommends using UTF-8 or UTF-16 session character sets. ASCII remains the default and provides best compatibility for existing applications that require only 127 characters defined. If existing applications encounter error 6734, see the remedies in Usage Notes.
However, you can re-enable TD-ASCII. To do so, contact your Teradata Customer Support representative.