To generate recommendations to improve the performance of a set of SQL queries in an application， you execute the following blocks of code：  
BEGIN 
dbms_advisor.create_task（dbms_advisor.sqlaccess_advisor，’TASK1’）； 
END； / 
BEGIN 
dbms_advisor.set_task_parameter（’TASK1’，’ANALYSIS_SCOPE’，’ALL’）； dbms_advisor.set_task_parameter（’TASK1’，’MODE’，’COMPREHENSIVE’）； 
END； 
/ 
BEGIN 
dbms_advisor.execute_task（’TASK1’）； 
dbms_output.put_line（dbms_advisor.get_task_script（’TASK1’））； 
END； 
/ 
The blocks of code execute successfully；however，you do not get the required outcome. 
What could be the reason？（）