The Union transformation can merge data from multiple source pipelines. The sources can have the same set of fields, have some matching fields, or use parameterized field mappings.
When you work with field mappings in a Union transformation, note the following:
•You must use input groups where the fields have the identical name, type, precision, and scale.
•You can edit, remove, or manually add some of the output fields.
•As part of the field mapping, you choose an input group and specify the parameter from the input group.
•You can use parameters for fields in all input groups.
•You can parameterize the field mapping or map by field name for each input group. At run time, the task adds an exact copy of the fields from the input group as output fields.
If you want Data Integration to automatically link fields with the same name and you also want to manually map fields, select the Manual option and click Automap.
You can map fields in the following ways:
•Exact Field Name. Data Integration matches fields of the same name.
•Smart Map. Data Integration matches fields with similar names. For example, if you have an incoming field Cust_Name and a target field Customer_Name, Data Integration automatically links the Cust_Name field with the Customer_Name field.
You can use both Exact Field Name and Smart Map in the same field mapping. For example, use Exact Field Name to match fields with the same name and then use Smart Map to map fields with similar names.
You can undo all automapped field mappings by clicking Automap > Undo Automap. To unmap a single field, select the field to unmap and click Actions > Unmap.
Data Integration highlights newly mapped fields. For example, when you use Exact Field Name, Data Integration highlights the mapped fields. If you then use Smart Map, Data Integration only highlights the fields mapped using Smart Map.