In SSIS when we will use data source as XML Source and transmit to any destination source, we may get warning message like:
The output column "" on output "" and component "XML Source" is not subsequently used in the Data Flow task. Removing this unused output column can increase Data Flow task performance.
Cause: We are getting a data from a column of XML source but we are not using this. So it would be better to delete or remove that column from XML source to increase the performance.
Step 1: Right click on your Component "XML Source" and click one edit option.
Step 2: Click on Column tab and choose your Output from combo box.
Step 3: Unchecked the columns name in list which you don't want to use and click on OK button.
Note: It is necessary to select at least one column in each Output.
Note: in same way we can remove the unused columns for other component.