Analyze Stale Job

BEGIN
  DBMS_SCHEDULER.create_job (
    job_name        => 'analyze_stale',
    job_type        => 'PLSQL_BLOCK',
    job_action      => 'BEGIN DBMS_STATS.gather_schema_stats(''LDBO'',CASCADE=>TRUE,options=>''GATHER STALE''); END;',
    start_date      => '01-APR-12 09.00.00 AM ASIA/CALCUTTA',
     repeat_interval=> 'freq=minutely;bysecond=0;byminute=00,20,40;byhour=9,10,11,12,13,14,15,16,17;byday=MON,TUE,WED,THU,FRI',
    enabled         => TRUE,
    comments        => 'JOB to gather LDBO stale statistics every 20 min');
END;
/