By default, a Union transformation has two input groups. If you want to merge data from more than two sources, add an input group for each additional source. Each group can have different field rules for each upstream transformation.
The input groups have the following characteristics:
The Union transformation initializes its output fields based on fields in the first source that you connect to an input group.
Each input group can use a different field mapping mode or parameter.
You can parameterize the field mappings or define the field mapping for each input group.
To add an input group, in the Mapping Designer, connect an upstream transformation to the "New Group" group of the Union transformation. You can also add input groups on the
tab of the Union transformation.
You can rename input groups. You can also delete input groups as long as there are at least two remaining input groups. Rename and delete input groups on the