You can configure the target load order for a mapping containing any type of target definition. In the Designer, you can set the order in which the Integration Service sends rows to targets in different target load order groups in a mapping. A target load order group is the collection of source qualifiers, transformations, and targets linked together in a mapping. You can set the target load order if you want to maintain referential integrity when inserting, deleting, or updating tables that have the primary key and foreign key constraints.

The Integration Service reads sources in a target load order group concurrently, and it processes target load order groups sequentially regardless of the type of target. If the target is a copy of the same flat file target and you specify the Append if Exists property for the target in the session properties, the Integration Service processes all the target load order groups.

To specify the order in which the Integration Service sends data to targets, create one source qualifier for each target within a mapping. To set the target load order, you then determine in which order the Integration Service reads each source in the mapping.

The following figure shows two target load order groups in one mapping:

In this mapping, the first target load order group includes ITEMS, SQ_ITEMS, and T_ITEMS. The second target load order group includes all other objects in the mapping, including the TOTAL_ORDERS target. The Integration Service processes the first target load order group, and then the second target load order group.

When it processes the second target load order group, it reads data from both sources at the same time.