Autonomous Schema Update(ASU) helps resolve the SQL width problem by updating the SQL column width in schema automatically when Authorized Data Truncation(ADT) occurs for data in a column. So, the first time a SQL query is executed, with ASU and ADT enabled, truncated data is returned and the column width is adjusted to accommodate the complete data. Users should execute the query again to get the complete data. The ASU feature is turned off by default and the user has to authorize this feature. To enable the feature, a server startup parameter -SQLWidthUpdate is added. This parameter takes the values as ON and OFF. The default value is OFF. To use this feature, provide the value of the -SQLWidthUpdate parameter as ON during startup. Once the value of the parameter is set, it is remembered for the lifetime of the server and for all connections. If the value of the -SQLWidthUpdate parameter is set to ON during startup, the Authorized Data Truncation(ADT) feature is also enabled irrespective of whether ADT was enabled during startup unless specified otherwise using connection URL. If for a specific connection, the ADT feature is disabled using connection URL and the ASU feature is enabled during startup, the ADT feature remains turned off for that specific connection.
Note: The ASU parameter can be provided only during server startup and not in the client connection URL.
