Transformations are the most important aspect of the Informatica PowerCenter tool. The functionality of any ETL tool lies in transformations. Needless to say, transformations are used to transform data. Informatica PowerCenter provides multiple transformations, each serving a particular functionality. Transformations can be created as reusable or nonreusable based on the requirement. The transformations created in Workflow Manager are nonreusable, and those created in the task developer are reusable. You can create a mapping with a single transformation or with multiple transformations.
When you run the workflow, Integration Services extracts the data in a row-wise manner from the source path/connection you defined in the session task and makes it flow from the mapping. The data reaches the target through the transformations you defined.
The data always flows in a row-wise manner in Informatica no matter what your calculation or manipulation is. So if you have 10 records in source, there will be 10 source to target flows while the process is executed.
There are various ways in which you can create the transformation in the Designer tool. They are discussed in the upcoming sections.
To create transformations using Mapping Designer, perform the following steps:
- Open the mapping in Mapping Designer. Then open the mapping in which you wish to add a transformation, and navigate to Transformation | Create.
- From the drop-down list of transformations, select the transformation you wish to create, and specify the name. Click on Create, and then click on Done.
The transformation appears in the Mapping Designer Workspace. For reference, we have created an Expression transformation in the preceding image. You can create all other transformations in the same way.
The transformations you create in Mapping Designer are nonreusable, so you cannot use them in other mappings. However, you can change the transformation to reusable.
To create the transformation in Mapplet Designer, perform the following steps:
- Open the Mapplet in Mapplet Designer, and navigate to Transformation | Create, as shown in the preceding screenshot.
- From the drop-down list of transformations, select the transformation you wish to create and specify the name.
To create the transformation in the designer, perform the following steps:
- Open Transformation Developer and navigate to Transformation | Create as shown in Mapping Designer.
- From the drop-down list of transformations, select the transformation you wish to create and specify the name as shown in Mapping Designer.
The transformations created in Transformation Developer are reusable, so you can use them across multiple mappings or mapplets.
With this basic understanding, we are all set to jump into the most important aspect of the Informatica PowerCenter tool, which is transformation.