Autonomous Transaction
An autonomous transaction divides a main transaction into several sub-transactions. The main transaction is executed only after the sub-transactions are executed. Sub-transactions are independent of the main transaction. The ROLLBACK and COMMIT operations in a sub-transaction affect only the DML operations in the sub-transaction. Similarly, the ROLLBACK and COMMIT operations in the main transaction affect only the DML operations in the main transaction, and do not affect the DML operations in the sub-transactions. A COMMIT operation in a sub-transaction will not be undone by the ROLLBACK operation in the main transaction.
An autonomous transaction is defined in a function or stored procedure and specified by the PRAGMA AUTONOMOUS_TRANSACTION keyword.