An Extend component adds calculated columns to input records. It allows you to add one or more columns, values of which are calculated based on the input column values and data flow variables. To extend a specific nested type property, select it from the Scope dropdown.
To configure Extend, you need to set up its Output Schema using the Mapping Editor. Create parameters, which correspond to the result columns, and configure their mapping.
Extend component has one input and one regular Default output for successfully processed rows with calculated columns added. It also has the Error output, to which it passes records, for which one of the expressions failed with an error, and adds the Error column with an error message to them.