The default value must be either a NULL, a constant value, a constant expression, an ERROR function, or an ABORT function.

For input/output ports, the Integration Service uses default values to handle null input values. The output default value of input/output ports is always ERROR(‘Transformation Error’).

Variable ports do not use default values.

You can assign default values to group by ports in the Aggregator and Rank transformations.

Not all port types in all transformations allow user-defined default values. If a port does not allow user-defined default values, the default value field is disabled.

Not all transformations allow user-defined default values.

If a transformation is not connected to the mapping data flow, the Integration Service ignores user-defined default values.

If any input port is unconnected, its value is assumed to be NULL and the Integration Service uses the default value for that input port.

If an input port default value contains the ABORT function and the input value is NULL, the Integration Service immediately stops the session. Use the ABORT function as a default value to restrict null input values. The first null value in an input port stops the session.

If an output port default value contains the ABORT function and any transformation error occurs for that port, the session immediately stops. Use the ABORT function as a default value to enforce strict rules for transformation errors. The first transformation error for this port stops the session.

The ABORT function, constant values, and constant expressions override ERROR functions configured in output port expressions.