Mappings > Parameters


Parameters are placeholders that represent values in a mapping or mapplet. Use parameters to hold values that you want to define at run-time such as a source connection, a target object, or the join condition for a Joiner transformation. You can also use parameters to hold values that change between task runs such as a time stamp that is incremented each time a mapping runs.
You can create the following kinds of parameters in a mapping or mapplet:
Input Parameters
An input parameter is a placeholder for a value or values in a mapping or mapplet. Input parameters help you control the logical aspects of a data flow or to set other variables that you can use to manage different targets.
When you define an input parameter in a mapping, you set the value of the parameter when you configure a mapping task.
In-Out Parameters
An in-out parameter holds a variable value that can change each time a task runs, to handle things like incremental data loading. When you define an in-out parameter, you can set a default value in the mapping but you typically set the value at run time using an Expression transformation. You can also change the value in the mapping task.
You cannot use an in-out parameter in an elastic mapping.