What is a mapping?

A mapping is a set of source and target definitions linked by the transformation objects that define the rles for data transformation. Mappings represent the data flow between sources and targets. When the Informatica Server executes a session, it uses the instructions configured in the mapping to read, transform, and write data.

Every mapping must contain the following components:

• Source definition: It describes the characteristics of a source table or file.
• Transformation: How to modify data before writing it to targets. Use different transformation objects to on the source data and obtain different results.
• Target definition: It defines the target table or flat file.
• Links (or) Connectors: Connect sources, targets, and transformations so the Informatica Server can move the data as it transforms it.

A mapping can also contain one or more mapplets. A mapplet is a set of transformations that you build in the Mapplet Designer and can use in multiple mappings. When you add an object to a mapping, you configure the properties according to the way you want the Informatica Server to transform the data. You also connect the mapping objects according to the way you want the Informatica Server to move the data. You connect the objects through ports. The Mapping Designer displays objects in three different views:

• Iconized. Shows an icon of the object with the object name.
• Normal. Shows the columns in the ports tab and the input and output port indicators. You can connect objects that are in the normal view.
• Edit. Shows the object properties. You can switch between the different tabs and configure the object in this view.