Input, output, and input/output ports have a system default value that you can sometimes override with a user-defined default value. Default values have different functions in different types of ports:
The system default value for null input ports is NULL. The default value appears as a blank in the transformation. If an input value is NULL, the Integration Service leaves it as NULL.
The system default value for output transformation errors is ERROR. The default value appears in the transformation as ERROR(‘transformation error’). If a transformation error occurs, the Integration Service skips the row. The Integration Service notes all input rows that the ERROR function skips in the log file.
The following errors are transformation errors:
Data conversion errors, such as passing a number to a date function.
Expression evaluation errors, such as dividing by zero.
Calls to an ERROR function.
The system default value for null input is the same as input ports, NULL. The system default value appears as a blank in the transformation. The default value for output transformation errors is the same as output ports. The default value for output transformation errors does not display in the transformation.
The Java Transformation converts PowerCenter® datatypes to Java datatypes, based on the Java Transformation port type. Default values for null input differ based on the Java datatype.
The following table shows the system default values for ports in connected transformations:
Integration Service Behavior
User-Defined Default Value Supported
Integration Service passes all input null values as NULL.
Integration Service calls the ERROR function for output port transformation errors. The Integration Service skips rows with errors and writes the input data and the error message in the log file.
Variable ports do not support default values. The Integration Service initializes variable ports according to the datatype.
You can override some of the default values to change the Integration Service behavior when it encounters null input values and output transformation errors.