You might configure a target load order constraint when you are inserting rows to targets that have a primary key-foreign key relationship. Configure the target with the primary key as the primary target instance. Configure the target with the foreign key as the secondary target instance. The Data Integration Service can stage the data for the secondary target until it completes loading the primary target.

When you need to delete rows from targets with a primary key-foreign key relationship, you configure a different constraint. Configure the target with the foreign key as the primary target instance to delete the rows from the detail target first. Configure the target with the primary key as the secondary target instance.

You can configure a target load order constraint for a mapping that loads insert rows and update rows to a relational table from two separate transformations. Configure the constraint to restrict the Data Integration Service from loading the update rows until after it loads the insert rows.

You can configure a target load order constraint for a mapping that loads rows into multiple flat file targets. Configure the target load order to load the secondary flat file after the primary flat file.