System parameters are built-in parameters for a Data Integration Service. System parameters define the directories where the Data Integration Service stores log files, cache files, reject files, source files, target files, and temporary files. An administrator defines the system parameter default values for a Data Integration Service in the Administrator tool.

User-defined parameters are parameters that you define in transformations, mappings, or workflows.

Create user-defined parameters to rerun a mapping with different connection, flat file, cache file, temporary file, expression, ports, or reference table values.

You can override parameter values using a parameter set or a parameter file. A parameter set is a repository object that contains mapping parameter values. A parameter file is an XML file that contains parameter values. When you run the mapping with a parameter set or a parameter file, the Data Integration Service uses the parameter values defined in the parameter set or parameter file instead of the default parameter values you configured in the transformation, mapping, or workflow.

You can use the following parameters to represent additional properties in the Hadoop environment:

For more information about mapping parameters, see the

Informatica Developer Mapping Guide

.