You can configure one or more fields as update columns in relational targets. Update columns are columns that uniquely identify rows in the target table. The mapping task uses them to update, upsert, or delete data in the target.
Configure update columns when the target table does not contain a primary key and the mapping uses an update, upsert, or delete operation. When you select more than one update column, the mapping uses the AND operator with the update columns to identify matching rows.
When you run the mapping, it uses the field mapping to match rows in the upstream transformations to the target table. If the
task matches an incoming row to multiple target rows, it performs the specified task operation on all matched target rows.
When you use a parameter for the target connection or target object, you can configure update columns in the