SQL_ID: xxxx cannot be found

Hi,

On 11.2.0.4 when running:

select plan_table_output from

  table(dbms_xplan.display_cursor('xxxx',null,'basic'));

I receive :

PLAN_TABLE_OUTPUT                                                                                                                                              

--------------------------------------------------------------------------------------------------

SQL_ID: xxxx cannot be found 

The query with sql_id xxxx was run 8 days ago. Then older than 7.

Thanks and happy new year.