A success constraint is an SSIS precedence constraint that runs a downstream task only after the preceding task completes successfully. If the preceding task fails, the connected task does not run. section 6.0
Mistake: treating every connection as a success constraint without considering failure handling. This creates a deliberately sequential control flow, but a failed load also prevents later aggregation or cleanup tasks from running. section 6.3.1
Use success constraints when:
- A later task must depend on a successful earlier task. section 6.0
- Tasks should execute serially rather than in parallel. section 6.0
- A package should stop its normal path when a task fails. section 6.3.1
Marketing load sequence
Connect the staging load, aggregate MERGE, and staging-table TRUNCATE tasks with success constraints. The aggregate runs only after the load succeeds, and truncation runs only after the aggregate succeeds. A conversion error while loading dirty staging data prevents both later tasks from running. section 6.3.1
Do not confuse a green success constraint in the control flow with a data-flow path: precedence constraints control tasks, whereas data paths carry rows that pass or fail a component. section 6.0
