Derived columns, which have values derived from the evaluation of expressions, require derived column names. A derived column name must be defined in the schema of a job script, and if multiple schemas are used, identically defined in all schemas.
The following warnings and errors can occur:
- Incompatibility between the schema-defined derived column and the resulting data type attributes of the expression, such as assigning a numeric value to a CHAR column
An error results when the script is compiled, and the job terminates.
- An incompatibility such as the value of a numeric expression being outside the range of the data type of its derived numeric column, which can be detected only during execution.
An error results, and the job terminates.
- Truncated characters due to an incompatibility in character data type length.
When the script is compiled, one warning is generated for every applicable derived column, but no run-time message is generated if truncation occurs.