A mapplet is a reusable object that you create in the Mapplet Designer. It contains a set of transformations and lets you reuse the transformation logic in multiple mappings.
For example, if you have several fact tables that require a series of dimension keys, you can create a mapplet containing a series of Lookup transformations to find each dimension key. You can then use the mapplet in each fact table mapping, rather than recreate the same lookup logic in each mapping.
When you use a mapplet in a mapping, you use an instance of the mapplet. Like a reusable transformation, any change made to the mapplet is inherited by all instances of the mapplet.
Mapplets help simplify mappings in the following ways:
Include source definitions.
Use multiple source definitions and source qualifiers to provide source data for a mapping.
Accept data from sources in a mapping.
If you want the mapplet to receive data from the mapping, use an Input transformation to receive source data.
Include multiple transformations.
A mapplet can contain as many transformations as you need.
Pass data to multiple transformations.
You can create a mapplet to feed data to multiple transformations. Each Output transformation in a mapplet represents one output group in a mapplet.
Contain unused ports.
You do not have to connect all mapplet input and output ports in a mapping.