Autonomous Schema Update (ASU) helps overcome the SQL width problem encountered when database field values are larger than the field size as defined in SQL. It solves this problem by automatically updating the SQL field width in schema wherever there is a data truncation event for the field. Autonomous Schema Update is based on truncation events generated by Authorized Data Truncation (ADT). ASU activation enables ADT internally, and you can observe the same behavior pertaining to DDM-configured fields as described for ADT.

For more information, see Authorized data truncation.