If the transaction control expression returns a rollback value, the Integration Service rolls back the transaction and writes a message to the session log indicating that the transaction was rolled back. It also indicates how many rows were rolled back.
The following message is a sample message that the Integration Service writes to the session log when the transaction control expression returns a rollback value:
WRITER_1_1_1> WRT_8326 User-defined rollback processed
WRITER_1_1_1> WRT_8331 Rollback statistics
WRT_8330 Rolled back  inserted,  deleted,  updated rows for the target [TCustOrders]