The following mapping is configured to perform constraint-based loading:
In the first pipeline, target T_1 has a primary key, T_2 and T_3 contain foreign keys referencing the T1 primary key. T_3 has a primary key that T_4 references as a foreign key.
Since these tables receive records from a single active source, SQ_A, the Integration Service loads rows to the target in the following order:
T_2 and T_3 (in no particular order)
The Integration Service loads T_1 first because it has no foreign key dependencies and contains a primary key referenced by T_2 and T_3. The Integration Service then loads T_2 and T_3, but since T_2 and T_3 have no dependencies, they are not loaded in any particular order. The Integration Service loads T_4 last, because it has a foreign key that references a primary key in T_3.
After loading the first set of targets, the Integration Service begins reading source B. If there are no key relationships between T_5 and T_6, the Integration Service reverts to a normal load for both targets.
If T_6 has a foreign key that references a primary key in T_5, since T_5 and T_6 receive data from a single active source, the Aggregator AGGTRANS, the Integration Service loads rows to the tables in the following order:
T_1, T_2, T_3, and T_4 are in one target connection group if you use the same database connection for each target, and you use the default partition properties. T_5 and T_6 are in another target connection group together if you use the same database connection for each target and you use the default partition properties. The Integration Service includes T_5 and T_6 in a different target connection group because they are in a different target load order group from the first four targets.