Run a DBMS_PIPE.RECEIVE_MESSAGE call to empty the local buffer
SQL> SET ECHO ON SQL> SET SERVEROUTPUT ON SIZE 1000000 SQL> SQL> SQL> SQL> SELECT DBMS_PIPE.RECEIVE_MESSAGE('Nowhere',0) 2 FROM dual; DBMS_PIPE.RECEIVE_MESSAGE('NOW ------------------------------ 1 1 row selected. SQL> SQL> SQL>